Alert archive / Missouri / Heat Advisories in 2021

Heat Advisory 5, NWS St. Louis, MO

August 22, 202129 counties in Missouri; 17 counties in Illinois

NWS St. Louis, MO issued this heat advisory at Aug 22, 2021, 2:59 PM CDT for 29 counties in Missouri; 17 counties in Illinois. It took effect at Aug 23, 2021, 1:00 PM CDT. It was in force for 5 days.

The area

The counties it named.

The facts

Issued
Aug 22, 2021, 2:59 PM CDT (19:59 UTC)
In effect from
Aug 23, 2021, 1:00 PM CDT
Expired
Aug 28, 2021, 7:00 PM CDT
In force
5 days
Issued by
NWS St. Louis, MO
All 46 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Pike County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Madison County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Shelby County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 18 km from the middle of the area, began a volume at 19:59 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.0 hours before the alert went out and 241 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2021-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2021-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
964 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
-9 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

806 
WWUS73 KLSX 221959
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
259 PM CDT Sun Aug 22 2021

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-231000-
/O.NEW.KLSX.HT.Y.0005.210823T1800Z-210827T0200Z/
Adams IL-Audrain MO-Boone MO-Brown IL-Calhoun IL-Callaway MO-
Clinton IL-Cole MO-Crawford MO-Franklin MO-Gasconade MO-Iron MO-
Jefferson MO-Jersey IL-Knox MO-Lewis MO-Lincoln MO-Madison IL-
Madison MO-Marion MO-Moniteau MO-Monroe IL-Monroe MO-
Montgomery MO-Osage MO-Pike IL-Pike MO-Ralls MO-Randolph IL-
Reynolds MO-Saint Charles MO-Saint Clair-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-Shelby MO-
Warren MO-Washington IL-Washington MO-
Including the cities of Alton, Belleville, Bowling Green, 
Cahokia, Chester, Columbia, Edwardsville, Farmington, Fulton, 
Hannibal, Jefferson City, Mexico, Mount Sterling, Pittsfield, 
Quincy, Saint Charles, Saint Louis, Sparta, Sullivan, Union, 
and Washington
259 PM CDT Sun Aug 22 2021

...HEAT ADVISORY IN EFFECT FROM 1 PM MONDAY TO 9 PM CDT
THURSDAY...

* WHAT...Heat index values up to 105 expected.

* WHERE...Portions of central, east central, northeast and 
  southeast Missouri and south central, southwest and west 
  central Illinois.

* WHEN...From 1 PM Monday to 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event..

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Carney
13 follow-up statements
686 
WWUS73 KLSX 230842
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
342 AM CDT Mon Aug 23 2021

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-232345-
/O.CON.KLSX.HT.Y.0005.210823T1800Z-210827T0200Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
342 AM CDT Mon Aug 23 2021

...HEAT ADVISORY REMAINS IN EFFECT FROM 1 PM THIS AFTERNOON TO 9 PM 
CDT THURSDAY...

* WHAT...Heat index values up to 106 expected.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. Portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...From 1 PM this afternoon to 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Britt
095 
WWUS73 KLSX 231958
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
258 PM CDT Mon Aug 23 2021

ILZ058>060-064-065-070-241100-
/O.EXB.KLSX.HT.Y.0005.210824T1800Z-210827T0200Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
258 PM CDT Mon Aug 23 2021

...HEAT ADVISORY IN EFFECT FROM 1 PM TUESDAY TO 9 PM CDT THURSDAY...

* WHAT...Heat index values up to 110 expected.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...From 1 PM Tuesday to 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-241100-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
258 PM CDT Mon Aug 23 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THURSDAY...

* WHAT...Heat index values up to 110.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. Portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

$$

KD
963 
WWUS73 KLSX 240759
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
259 AM CDT Tue Aug 24 2021

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-242300-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
259 AM CDT Tue Aug 24 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THURSDAY...

* WHAT...Heat index values up to 110 expected.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. Portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

ILZ058>060-064-065-070-242300-
/O.CON.KLSX.HT.Y.0005.210824T1800Z-210827T0200Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
259 AM CDT Tue Aug 24 2021

...HEAT ADVISORY REMAINS IN EFFECT FROM 1 PM THIS AFTERNOON TO 9 PM 
CDT THURSDAY...

* WHAT...Heat index values up to 110 expected. 

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...From 1 PM this afternoon to 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

&&

$$

Britt
390 
WWUS73 KLSX 242011
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
311 PM CDT Tue Aug 24 2021

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-250815-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Adams IL-Audrain MO-Bond IL-Boone MO-Brown IL-Calhoun IL-
Callaway MO-Clinton IL-Cole MO-Crawford MO-Fayette IL-Franklin MO-
Gasconade MO-Greene IL-Iron MO-Jefferson MO-Jersey IL-Knox MO-
Lewis MO-Lincoln MO-Macoupin IL-Madison IL-Madison MO-Marion IL-
Marion MO-Moniteau MO-Monroe IL-Monroe MO-Montgomery IL-
Montgomery MO-Osage MO-Pike IL-Pike MO-Ralls MO-Randolph IL-
Reynolds MO-Saint Charles MO-Saint Clair-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-Shelby MO-
Warren MO-Washington IL-Washington MO-
Including the cities of Alton, Belleville, Bowling Green, 
Cahokia, Centralia, Chester, Columbia, Edwardsville, Farmington, 
Fulton, Hannibal, Jefferson City, Litchfield, Mexico, 
Mount Sterling, Pittsfield, Quincy, Saint Charles, Saint Louis, 
Salem, Sparta, Sullivan, Union, Vandalia, and Washington
311 PM CDT Tue Aug 24 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THURSDAY...

* WHAT...Heat index values up to 110 expected.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. Portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Maples
880 
WWUS73 KLSX 250820
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
320 AM CDT Wed Aug 25 2021

ILZ058>060-064-065-070-252330-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
320 AM CDT Wed Aug 25 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THURSDAY...

* WHAT...Heat index values up to 110.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...Until 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-252330-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
320 AM CDT Wed Aug 25 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THURSDAY...

* WHAT...Heat index values up to 110 expected.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. Portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

KD
720 
WWUS73 KLSX 251938
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
238 PM CDT Wed Aug 25 2021

ILZ058>060-064-065-070-261045-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
238 PM CDT Wed Aug 25 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THURSDAY...

* WHAT...Heat index values up to 107.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...Until 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-261045-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
238 PM CDT Wed Aug 25 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THURSDAY...

* WHAT...Heat index values up to 106.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. Portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 9 PM CDT Thursday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

* ADDITIONAL DETAILS...The effects of high heat are cumulative. This 
  is a 4 day heat event meaning that heat index values up to around 
  105 are expected each afternoon. Warm nighttime temperatures will 
  allow little recovery for those who are sensitive to heat. Heat 
  related illnesses will become more likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

&&

$$

Glass
157 
WWUS73 KLSX 260744
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
244 AM CDT Thu Aug 26 2021

ILZ058>060-064-065-070-262245-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
244 AM CDT Thu Aug 26 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THIS EVENING...

* WHAT...Heat index values up to 110 expected.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...Until 9 PM CDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative.
  This is a 4 day heat event meaning that heat index values up to
  around 105 are expected each afternoon. Warm nighttime
  temperatures will allow little recovery for those who are
  sensitive to heat. Heat related illnesses will become more
  likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-262245-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210827T0200Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
244 AM CDT Thu Aug 26 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 9 PM CDT THIS EVENING...

* WHAT...Heat index values up to 110 expected.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. Portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 9 PM CDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

* ADDITIONAL DETAILS...The effects of high heat are cumulative. This 
  is a 4 day heat event meaning that heat index values up to around 
  105 are expected each afternoon. Warm nighttime temperatures will 
  allow little recovery for those who are sensitive to heat. Heat 
  related illnesses will become more likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

KD
434 
WWUS73 KLSX 261907
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
207 PM CDT Thu Aug 26 2021

ILZ058>060-064-065-070-271015-
/O.EXT.KLSX.HT.Y.0005.000000T0000Z-210828T0000Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
207 PM CDT Thu Aug 26 2021

...HEAT ADVISORY NOW IN EFFECT UNTIL 7 PM CDT FRIDAY...

* WHAT...Heat index values up to 105.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...Until 7 PM CDT Friday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

* ADDITIONAL DETAILS...The effects of high heat are cumulative. This 
  is a 4 day heat event meaning that heat index values up to around 
  105 are expected each afternoon. Warm nighttime temperatures will 
  allow little recovery for those who are sensitive to heat. Heat 
  related illnesses will become more likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-271015-
/O.EXT.KLSX.HT.Y.0005.000000T0000Z-210828T0000Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
207 PM CDT Thu Aug 26 2021

...HEAT ADVISORY NOW IN EFFECT UNTIL 7 PM CDT FRIDAY...

* WHAT...Heat index values up to 104.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 7 PM CDT Friday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

* ADDITIONAL DETAILS...The effects of high heat are cumulative. This 
  is a 4 day heat event meaning that heat index values up to around 
  105 are expected each afternoon. Warm nighttime temperatures will 
  allow little recovery for those who are sensitive to heat. Heat 
  related illnesses will become more likely each day of the event.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors.

&&

$$

Maples
996 
WWUS73 KLSX 270854
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
354 AM CDT Fri Aug 27 2021

ILZ058>060-064-065-070-280000-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210828T0000Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
354 AM CDT Fri Aug 27 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING...

* WHAT...Heat index values up to 104.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...Until 7 PM CDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors. Young children and 
pets should never be left unattended in vehicles under any 
circumstances. Take extra precautions if you work or spend time 
outside. When possible reschedule strenuous activities to early 
morning or evening. Know the signs and symptoms of heat exhaustion 
and heat stroke. Wear lightweight and loose fitting clothing when 
possible. To reduce risk during outdoor work, the Occupational 
Safety and Health Administration recommends scheduling frequent rest 
breaks in shaded or air conditioned environments. Anyone overcome by 
heat should be moved to a cool and shaded location. Heat stroke is 
an emergency! Call 9 1 1.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-280000-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210828T0000Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
354 AM CDT Fri Aug 27 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING...

* WHAT...Heat index values up to 105.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 7 PM CDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People in the Saint Louis Metropolitan Area can get information 
about cooling centers orenergy assistance related to the excessive 
heat by calling the United Way of Greater SaintLouis at 
800-427-4626, or if calling from a land line phone dial 2-1-1. You 
can also callCool Down Saint Louis at 314-241-7668.

&&

$$

Gosselin
239 
WWUS73 KLSX 271910
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
210 PM CDT Fri Aug 27 2021

ILZ058>060-064-065-070-281015-
/O.EXT.KLSX.HT.Y.0005.000000T0000Z-210829T0000Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
210 PM CDT Fri Aug 27 2021

...HEAT ADVISORY NOW IN EFFECT UNTIL 7 PM CDT SATURDAY...

* WHAT...Heat index values up to 103.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...Until 7 PM CDT Saturday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors. Young children and 
pets should never be left unattended in vehicles under any 
circumstances.Take extra precautions if you work or spend time 
outside. When possible reschedule strenuous activities to early 
morning or evening. Know the signs and symptoms of heat exhaustion 
and heat stroke. Wear lightweight and loose fitting clothing when 
possible. To reduce risk during outdoor work, the Occupational 
Safety and Health Administration recommends scheduling frequent rest 
breaks in shaded or air conditioned environments. Anyone overcome by 
heat should be moved to a cool and shaded location. Heat stroke is 
an emergency! Call 9 1 1.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-281015-
/O.EXT.KLSX.HT.Y.0005.000000T0000Z-210829T0000Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
210 PM CDT Fri Aug 27 2021

...HEAT ADVISORY NOW IN EFFECT UNTIL 7 PM CDT SATURDAY...

* WHAT...Heat index values up to 103.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 7 PM CDT Saturday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People in the Saint Louis Metropolitan Area can get information 
about cooling centers orenergy assistance related to the excessive 
heat by calling the United Way of Greater SaintLouis at 
800-427-4626, or if calling from a land line phone dial 2-1-1. You 
can also callCool Down Saint Louis at 314-241-7668.

&&

$$

Maples
640 
WWUS73 KLSX 280847
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
347 AM CDT Sat Aug 28 2021

ILZ058>060-064-065-070-290000-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210829T0000Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
347 AM CDT Sat Aug 28 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING...

* WHAT...Heat index values up to 102.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...Until 7 PM CDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors. Young children and 
pets should never be left unattended in vehicles under any 
circumstances.Take extra precautions if you work or spend time 
outside. When possible reschedule strenuous activities to early 
morning or evening. Know the signs and symptoms of heat exhaustion 
and heat stroke. Wear lightweight and loose fitting clothing when 
possible. To reduce risk during outdoor work, the Occupational 
Safety and Health Administration recommends scheduling frequent rest 
breaks in shaded or air conditioned environments. Anyone overcome by 
heat should be moved to a cool and shaded location. Heat stroke is 
an emergency! Call 9 1 1.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-290000-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210829T0000Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
347 AM CDT Sat Aug 28 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING...

* WHAT...Heat index values up to 102.

* WHERE...Portions of southwest and west central Illinois. Portions 
  of central, east central, northeast, and southeast Missouri.

* WHEN...Until 7 PM CDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People in the Saint Louis Metropolitan Area can get information 
about cooling centers or energy assistance related to the excessive 
heat by calling the United Way of Greater Saint Louis at 
800-427-4626, or if calling from a land line phone dial 2-1-1. You 
can also call Cool Down Saint Louis at 314-241-7668.

&&

$$

GKS
264 
WWUS73 KLSX 281945
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
245 PM CDT Sat Aug 28 2021

ILZ058>060-064-065-070-290000-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210829T0000Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Marion IL-
Including the cities of Litchfield, Centralia, Salem, and
Vandalia
245 PM CDT Sat Aug 28 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING...

* WHAT...Heat index values up to 100 this afternoon.

* WHERE...Bond IL, Fayette IL, Marion IL, Montgomery IL, Greene IL 
  and Macoupin IL Counties.

* WHEN...Until 7 PM CDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of 
the sun, and check up on relatives and neighbors. Young children and 
pets should never be left unattended in vehicles under any 
circumstances.Take extra precautions if you work or spend time 
outside. When possible reschedule strenuous activities to early 
morning or evening. Know the signs and symptoms of heat exhaustion 
and heat stroke. Wear lightweight and loose fitting clothing when 
possible. To reduce risk during outdoor work, the Occupational 
Safety and Health Administration recommends scheduling frequent rest 
breaks in shaded or air conditioned environments. Anyone overcome by 
heat should be moved to a cool and shaded location. Heat stroke is 
an emergency! Call 9 1 1.

&&

$$

ILZ069-074-079-095>102-MOZ018-019-026-027-034>036-041-042-047>052-
059>065-072>075-084-085-099-290000-
/O.CON.KLSX.HT.Y.0005.000000T0000Z-210829T0000Z/
Clinton IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Saint Louis, Farmington, Mount Sterling,
Cahokia, Quincy, Pittsfield, Alton, Union, Washington, Sparta,
Bowling Green, Mexico, Jefferson City, Belleville, Edwardsville,
Chester, Saint Charles, Columbia, Hannibal, Sullivan, and Fulton
245 PM CDT Sat Aug 28 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING...

* WHAT...Heat index values up to 100 this afternoon.

* WHERE...Portions of south central, southwest, and west central 
  Illinois. portions of central, east central, northeast, and 
  southeast Missouri.

* WHEN...Until 7 PM CDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

People in the Saint Louis Metropolitan Area can get information 
about cooling centers orenergy assistance related to the excessive 
heat by calling the United Way of Greater SaintLouis at 
800-427-4626, or if calling from a land line phone dial 2-1-1. You 
can also callCool Down Saint Louis at 314-241-7668.

&&

$$

Glass
926 
WWUS73 KLSX 282353
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service St Louis MO
653 PM CDT Sat Aug 28 2021

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-290100-
/O.EXP.KLSX.HT.Y.0005.000000T0000Z-210829T0000Z/
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL-
Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
Including the cities of Mount Sterling, Quincy, Cahokia, Union,
Bowling Green, Columbia, Pittsfield, Alton, Sparta, Centralia,
Farmington, Vandalia, Litchfield, Saint Louis, Jefferson City,
Belleville, Edwardsville, Chester, Hannibal, Fulton, Saint
Charles, Mexico, Sullivan, Washington, and Salem
653 PM CDT Sat Aug 28 2021

...HEAT ADVISORY WILL EXPIRE AT 7 PM CDT THIS EVENING...

Heat index values have fallen below 100 degrees, allowing the Heat 
Advisory to expire.

$$

19

What forecasters said that day

The local office's own words before this heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS St. Louis, MO wrote its last area forecast discussion before this heat advisory went out at Aug 22, 12:43 PM CDT, 2 hours 16 minutes earlier.

Area forecast discussion, Aug 22, 12:43 PM CDT, 2 hours 16 minutes before
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1243 PM CDT Sun Aug 22 2021

.SHORT TERM... (Through Late Monday Night)
Issued at 331 AM CDT Sun Aug 22 2021

Upper-level ridging is currently present over the Middle
Mississippi Valley with an area of high pressure settling in over
the Upper Midwest at the surface. This surface high will keep low-
level winds out of the north today, ushering in near normal
temperatures and dry conditions. This weather will be short-lived,
as this evening and overnight, the upper-level ridge will begin
building further into the Central Plains and Midwest, pushing the
surface high further east. In turn, winds through the lower
atmosphere will turn southwesterly/southerly and advect warmer,
moister air into the CWA as Saturday's cold front lifts north as a
warm front tonight into early Monday morning.

Monday's temperatures will be notably different compared to what is
forecast for Sunday. Then, afternoon highs will peak roughly 10
degrees above normal, with temperatures in the mid to upper 90s for
most locations in the CWA. The return of higher dewpoints will allow
for widespread heat index values of 100-105. However, there
continues to be some uncertainty with these values due to a
potential decaying MCS as it passes near the CWA early in the day.
This may produce enough convective debris to keep temperatures lower
for at least the northern portion of the CWA. Due to the uncertainty
this MCS produces, we will let the day shift assess and make the
decision on a potential heat advisory for magnitude (heat index of
105) for portions of the CWA. Additional isolated to scattered
convection will also be possible during peak heating for portions of
the CWA, but this activity is not expected to be wide-spread enough
to drastically impact temperatures.

Elmore

.LONG TERM... (Tuesday through Saturday)
Issued at 331 AM CDT Sun Aug 22 2021

The heat will continue into at least mid-week, as ensemble
guidance keeps 850 mb temperatures in the low 20s and surface
temperatures around 10 degrees above normal. Confidence is high
that Tuesday will likely be the warmest day of the period, with
most locations in the CWA forecast to reach the mid-90s with
portions of central Missouri forecast to reach the upper-90s due
to closer positioning to the center of the ridge. Confidence is
also increasing that Wednesday may be just as warm, as ensemble
member spread is decreasing in regards to surface temperatures,
and converging on a warmer solution. Rain chances have also
decreased Wednesday afternoon per both deterministic and ensemble
guidance, increasing the probability of convection-free and
clearer skies allowing for surface heating.

Ensemble guidance begins to diverge moreso Thursday through the rest
of the period with the phasing of the ridge and associated surface
conditions. That being said, confidence is still high that
temperatures will cool at least by a couple degrees, as the warmest
ensemble members are still slightly cooler than what is forecast mid-
week. This translates to highs still reaching the low to mid-90s
area-wide. The NBM also has a chance of rain each day for this
portion of the period, but this is likely overdone due to the widely-
varying solutions composing the blend, and I anticipate that there
will be plenty of dry time.

Elmore

&&

.AVIATION...  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1235 PM CDT Sun Aug 22 2021

VFR flight conditions are expected to prevail across the area at
least through this evening. Some fog is possible again in south
central and southwest Illinois into southeast Missouri tomorrow
morning, but current indications are that if it develops at all it
should only reduce the visibility to 3-5 miles. Some model
guidance is hinting at widely scattered thunderstorms on Monday,
mainly after 18Z across the eastern Ozarks, though there are also
hints that some dissipating storms could move into the area from
the north during the early morning. Overall though, the chance of
precipitation is too low to mention in the TAFs at this time.

Carney

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

WFO LSX
Hazardous weather outlook, Aug 22, 3:44 AM CDT, 11 hours 15 minutes before
Hazardous Weather Outlook
National Weather Service Saint Louis MO
344 AM CDT Sun Aug 22 2021

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-230845-
Adams IL-Audrain MO-Bond IL-Boone MO-Brown IL-Calhoun IL-Callaway MO-
Clinton IL-Cole MO-Crawford MO-Fayette IL-Franklin MO-Gasconade MO-
Greene IL-Iron MO-Jefferson MO-Jersey IL-Knox MO-Lewis MO-Lincoln MO-
Macoupin IL-Madison IL-Madison MO-Marion IL-Marion MO-Moniteau MO-
Monroe IL-Monroe MO-Montgomery IL-Montgomery MO-Osage MO-Pike IL-
Pike MO-Ralls MO-Randolph IL-Reynolds MO-Saint Charles MO-
Saint Clair-Saint Francois MO-Saint Louis City MO-Saint Louis MO-
Sainte Genevieve MO-Shelby MO-Warren MO-Washington IL-Washington MO-
344 AM CDT Sun Aug 22 2021

This Hazardous Weather Outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

There is a chance of thunderstorms across parts of the area
Monday through Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated through tonight.

Elmore

Nearby

Heat Advisories in Missouri, 2021Heat Advisories in Illinois, 2021Every heat advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.