Alert archive / Missouri / Heat Advisories in 2018

Heat Advisory 4, NWS St. Louis, MO

July 3, 201817 counties in Illinois; 29 counties in Missouri

NWS St. Louis, MO issued this heat advisory at Jul 3, 2018, 3:31 AM CDT for 17 counties in Illinois; 29 counties in Missouri. It took effect at Jul 4, 2018, 12:00 PM CDT. It was in force for 32 hr.

The area

The counties it named.

The facts

Issued
Jul 3, 2018, 3:31 AM CDT (08:31 UTC)
In effect from
Jul 4, 2018, 12:00 PM CDT
Expired
Jul 5, 2018, 8:00 PM CDT
In force
32 hr
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 08:29 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 00:00Z, 8.5 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 00:00Z on 2018-07-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 32 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2018-07-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.1939Sfc1 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
32 J/kg
Mixed-layer CIN
-315 J/kg
Mixed-layer LCL
1395 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
2 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

957 
WWUS73 KLSX 030831
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
331 AM CDT Tue Jul 3 2018


ILZ058>060-064-065-069-070-074-079-098>102-MOZ061-063>065-073>075-
084-085-099-032045-
/O.NEW.KLSX.HT.Y.0004.180704T1700Z-180706T0100Z/
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Iron MO-
Jefferson MO-Jersey IL-Macoupin IL-Madison IL-Madison MO-
Marion IL-Monroe IL-Montgomery IL-Randolph IL-Reynolds MO-
Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Saint Charles, 
Saint Louis, Salem, Sparta, and Vandalia
331 AM CDT Tue Jul 3 2018

...HEAT ADVISORY IN EFFECT FROM NOON WEDNESDAY TO 8 PM CDT
THURSDAY...

The National Weather Service in Saint Louis has issued a Heat
Advisory, which is in effect from noon Wednesday to 8 PM CDT
Thursday.

* TIMING...Heat index values of 105 and higher are likely during
  the afternoon and early evening through Thursday evening.

* HEAT INDEX VALUES...Up to 107 due to temperatures in the mid 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of 
  minutes. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures and high
humidity will occur. This combination will create a situation in
which heat-related illnesses are possible, especially for those
living in un-air conditioned homes or apartments. People in the
Advisory area are advised to avoid poorly ventilated areas and
prolonged work in the sun. Also, keep plenty of liquids on hand
and try to stay in an air conditioned environment.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to the early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

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 immediately.

Where's baby? Look before you lock! Young children and pets
should never be left unattended in vehicles under any
circumstances. This is especially true during warm or hot weather
when car interiors can reach lethal temperatures in a matter of
minutes.

&&

$$

Byrd
8 follow-up statements
109 
WWUS73 KLSX 032105
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
405 PM CDT Tue Jul 3 2018


ILZ058>060-064-065-069-070-074-079-098>102-MOZ061-063>065-073>075-
084-085-099-040915-
/O.CON.KLSX.HT.Y.0004.180704T1700Z-180706T0100Z/
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Iron MO-
Jefferson MO-Jersey IL-Macoupin IL-Madison IL-Madison MO-
Marion IL-Monroe IL-Montgomery IL-Randolph IL-Reynolds MO-
Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Saint Charles, 
Saint Louis, Salem, Sparta, and Vandalia
405 PM CDT Tue Jul 3 2018

...HEAT ADVISORY REMAINS IN EFFECT FROM NOON WEDNESDAY TO 8 PM
CDT THURSDAY...

* TIMING...Heat index values of 105 and higher are likely during 
  the afternoon and early evening through Thursday evening.

* HEAT INDEX VALUES...Up to 107 due to temperatures in the mid 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures and high
humidity will occur. This combination will create a situation in
which heat-related illnesses are possible, especially for those
living in un-air conditioned homes or apartments. People in the
Advisory area are advised to avoid poorly ventilated areas and
prolonged work in the sun. Also, keep plenty of liquids on hand
and try to stay in an air conditioned environment.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to the early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

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 immediately.

Where's baby? Look before you lock! Young children and pets
should never be left unattended in vehicles under any
circumstances. This is especially true during warm or hot weather
when car interiors can reach lethal temperatures in a matter of
minutes.

&&

$$

Maples
857 
WWUS73 KLSX 040059
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
759 PM CDT Tue Jul 3 2018

ILZ095>097-MOZ018-019-026-027-034>036-041-042-047>052-059-060-062-
072-041300-
/O.EXB.KLSX.HT.Y.0004.180704T1700Z-180705T0100Z/
Adams IL-Audrain MO-Boone MO-Brown IL-Callaway MO-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Knox MO-Lewis MO-Lincoln MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike IL-
Pike MO-Ralls MO-Shelby MO-Warren MO-
Including the cities of Bowling Green, Columbia, Fulton, 
Hannibal, Jefferson City, Mexico, Mount Sterling, Pittsfield, 
Quincy, Sullivan, Union, and Washington
759 PM CDT Tue Jul 3 2018

...HEAT ADVISORY IN EFFECT FROM NOON TO 8 PM CDT WEDNESDAY...

The National Weather Service in Saint Louis has issued a Heat
Advisory, which is in effect from noon to 8 PM CDT Wednesday.

* TIMING...Heat index values of 105 and higher are likely during 
  the afternoon and early evening through Thursday evening.

* HEAT INDEX VALUES...Up to 106 due to temperatures in the mid 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

$$

ILZ058>060-064-065-069-070-074-079-098>102-MOZ061-063>065-073>075-
084-085-099-041300-
/O.CON.KLSX.HT.Y.0004.180704T1700Z-180706T0100Z/
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Iron MO-
Jefferson MO-Jersey IL-Macoupin IL-Madison IL-Madison MO-
Marion IL-Monroe IL-Montgomery IL-Randolph IL-Reynolds MO-
Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Saint Charles, 
Saint Louis, Salem, Sparta, and Vandalia
759 PM CDT Tue Jul 3 2018

...HEAT ADVISORY REMAINS IN EFFECT FROM NOON WEDNESDAY TO 8 PM
CDT THURSDAY...

* TIMING...Heat index values of 105 and higher are likely during 
  the afternoon and early evening through Thursday evening.

* HEAT INDEX VALUES...Up to 107 due to temperatures in the mid 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures and high
humidity will occur. This combination will create a situation in
which heat-related illnesses are possible, especially for those
living in un-air conditioned homes or apartments. People in the
Advisory area are advised to avoid poorly ventilated areas and
prolonged work in the sun. Also, keep plenty of liquids on hand
and try to stay in an air conditioned environment.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to the early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

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 immediately.

Where's baby? Look before you lock! Young children and pets
should never be left unattended in vehicles under any
circumstances. This is especially true during warm or hot weather
when car interiors can reach lethal temperatures in a matter of
minutes.

&&

$$

Britt
127 
WWUS73 KLSX 040756
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
256 AM CDT Wed Jul 4 2018


ILZ058>060-064-065-069-070-074-079-098>102-MOZ061-063>065-073>075-
084-085-099-042000-
/O.CON.KLSX.HT.Y.0004.180704T1700Z-180706T0100Z/
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Iron MO-
Jefferson MO-Jersey IL-Macoupin IL-Madison IL-Madison MO-
Marion IL-Monroe IL-Montgomery IL-Randolph IL-Reynolds MO-
Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Saint Charles, 
Saint Louis, Salem, Sparta, and Vandalia
256 AM CDT Wed Jul 4 2018

...HEAT ADVISORY REMAINS IN EFFECT FROM NOON TODAY TO 8 PM CDT
THURSDAY...

* TIMING...Heat index values of 105 and higher are likely during 
  the afternoon and early evening through Thursday evening.

* HEAT INDEX VALUES...Up to 107 due to temperatures in the mid 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures and high
humidity will occur. This combination will create a situation in
which heat-related illnesses are possible, especially for those
living in un-air conditioned homes or apartments. People in the
Advisory area are advised to avoid poorly ventilated areas and
prolonged work in the sun. Also, keep plenty of liquids on hand
and try to stay in an air conditioned environment.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to the early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

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 immediately.

Where's baby? Look before you lock! Young children and pets
should never be left unattended in vehicles under any
circumstances. This is especially true during warm or hot weather
when car interiors can reach lethal temperatures in a matter of
minutes.

&&

$$

ILZ095>097-MOZ018-019-026-027-034>036-041-042-047>052-059-060-062-
072-042000-
/O.CON.KLSX.HT.Y.0004.180704T1700Z-180705T0100Z/
Adams IL-Audrain MO-Boone MO-Brown IL-Callaway MO-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Knox MO-Lewis MO-Lincoln MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike IL-
Pike MO-Ralls MO-Shelby MO-Warren MO-
Including the cities of Bowling Green, Columbia, Fulton, 
Hannibal, Jefferson City, Mexico, Mount Sterling, Pittsfield, 
Quincy, Sullivan, Union, and Washington
256 AM CDT Wed Jul 4 2018

...HEAT ADVISORY REMAINS IN EFFECT FROM NOON TODAY TO 8 PM CDT
THIS EVENING...

* TIMING...Heat index values of 105 and higher are likely during
  the afternoon and early evening through this evening.

* HEAT INDEX VALUES...Up to 103 due to temperatures in the lower 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

$$

Byrd
810 
WWUS73 KLSX 042052
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
352 PM CDT Wed Jul 4 2018

ILZ058>060-064-065-069-070-074-079-098>102-MOZ061-063>065-073>075-
084-085-099-051200-
/O.CON.KLSX.HT.Y.0004.000000T0000Z-180706T0100Z/
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Iron MO-
Jefferson MO-Jersey IL-Macoupin IL-Madison IL-Madison MO-
Marion IL-Monroe IL-Montgomery IL-Randolph IL-Reynolds MO-
Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Saint Charles, 
Saint Louis, Salem, Sparta, and Vandalia
352 PM CDT Wed Jul 4 2018

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM CDT THURSDAY...

* TIMING...Heat index values of 105 and higher are likely during 
  the afternoon and early evening through Thursday evening.

* HEAT INDEX VALUES...Up to 107 due to temperatures in the mid 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures and high
humidity will occur. This combination will create a situation in
which heat-related illnesses are possible, especially for those
living in un-air conditioned homes or apartments. People in the
Advisory area are advised to avoid poorly ventilated areas and
prolonged work in the sun. Also, keep plenty of liquids on hand
and try to stay in an air conditioned environment.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to the early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

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 immediately.

Where's baby? Look before you lock! Young children and pets
should never be left unattended in vehicles under any
circumstances. This is especially true during warm or hot weather
when car interiors can reach lethal temperatures in a matter of
minutes.

&&

$$

ILZ095>097-MOZ018-019-026-027-034>036-041-042-047>052-059-060-062-
072-050100-
/O.CON.KLSX.HT.Y.0004.000000T0000Z-180705T0100Z/
Adams IL-Audrain MO-Boone MO-Brown IL-Callaway MO-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Knox MO-Lewis MO-Lincoln MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike IL-
Pike MO-Ralls MO-Shelby MO-Warren MO-
Including the cities of Bowling Green, Columbia, Fulton, 
Hannibal, Jefferson City, Mexico, Mount Sterling, Pittsfield, 
Quincy, Sullivan, Union, and Washington
352 PM CDT Wed Jul 4 2018

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM CDT THIS EVENING...

* TIMING...Heat index values of 105 and higher are likely during
  the afternoon and early evening.

* HEAT INDEX VALUES...Up to 104 due to temperatures in the mid 
  90s, and dewpoints in the lower 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

$$

Kanofsky
668 
WWUS73 KLSX 050100
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
800 PM CDT Wed Jul 4 2018

ILZ095>097-MOZ018-019-026-027-034>036-041-042-047>052-059-060-062-
072-050200-
/O.EXP.KLSX.HT.Y.0004.000000T0000Z-180705T0100Z/
Adams IL-Audrain MO-Boone MO-Brown IL-Callaway MO-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Knox MO-Lewis MO-Lincoln MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike IL-
Pike MO-Ralls MO-Shelby MO-Warren MO-
Including the cities of Bowling Green, Columbia, Fulton, 
Hannibal, Jefferson City, Mexico, Mount Sterling, Pittsfield, 
Quincy, Sullivan, Union, and Washington
800 PM CDT Wed Jul 4 2018

...HEAT ADVISORY WILL EXPIRE AT 8 PM CDT THIS EVENING...

Heat index values are falling into the 90s this evening. Therefore
the advisory will be allowed to expire.

$$

ILZ058>060-064-065-069-070-074-079-098>102-MOZ061-063>065-073>075-
084-085-099-051200-
/O.CON.KLSX.HT.Y.0004.000000T0000Z-180706T0100Z/
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Iron MO-
Jefferson MO-Jersey IL-Macoupin IL-Madison IL-Madison MO-
Marion IL-Monroe IL-Montgomery IL-Randolph IL-Reynolds MO-
Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Saint Charles, 
Saint Louis, Salem, Sparta, and Vandalia
800 PM CDT Wed Jul 4 2018

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM CDT THURSDAY...

* TIMING...Heat index values of 105 and higher are likely during
  the afternoon and early evening on Thursday.

* HEAT INDEX VALUES...Up to 107 due to temperatures in the mid 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures and high
humidity will occur. This combination will create a situation in
which heat-related illnesses are possible, especially for those
living in un-air conditioned homes or apartments. People in the
Advisory area are advised to avoid poorly ventilated areas and
prolonged work in the sun. Also, keep plenty of liquids on hand
and try to stay in an air conditioned environment.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to the early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

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 immediately.

Where's baby? Look before you lock! Young children and pets
should never be left unattended in vehicles under any
circumstances. This is especially true during warm or hot weather
when car interiors can reach lethal temperatures in a matter of
minutes.

&&

$$

Britt
303 
WWUS73 KLSX 050811
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
311 AM CDT Thu Jul 5 2018

ILZ095>097-052015-
/O.EXA.KLSX.HT.Y.0004.000000T0000Z-180706T0100Z/
Adams IL-Brown IL-Pike IL-
Including the cities of Mount Sterling, Pittsfield, and Quincy
311 AM CDT Thu Jul 5 2018

...HEAT ADVISORY IN EFFECT UNTIL 8 PM CDT THIS EVENING...

The National Weather Service in Saint Louis has issued a Heat
Advisory, which is in effect until 8 PM CDT this evening.

* TIMING...Heat index values of 105 and higher are likely during 
  the afternoon and early evening on Thursday.

* HEAT INDEX VALUES...Up to 105 due to temperatures in the lower 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

$$

ILZ058>060-064-065-069-070-074-079-098>102-MOZ061-063>065-073>075-
084-085-099-052015-
/O.CON.KLSX.HT.Y.0004.000000T0000Z-180706T0100Z/
Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Iron MO-
Jefferson MO-Jersey IL-Macoupin IL-Madison IL-Madison MO-
Marion IL-Monroe IL-Montgomery IL-Randolph IL-Reynolds MO-
Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Saint Charles, 
Saint Louis, Salem, Sparta, and Vandalia
311 AM CDT Thu Jul 5 2018

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM CDT THIS EVENING...

* TIMING...Heat index values of 105 and higher are likely during 
  the afternoon and early evening on Thursday.

* HEAT INDEX VALUES...Up to 106 due to temperatures in the mid 
  90s, and dewpoints in the mid 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures and high
humidity will occur. This combination will create a situation in
which heat-related illnesses are possible, especially for those
living in un-air conditioned homes or apartments. People in the
Advisory area are advised to avoid poorly ventilated areas and
prolonged work in the sun. Also, keep plenty of liquids on hand
and try to stay in an air conditioned environment.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to the early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

&&

$$

BSH
330 
WWUS73 KLSX 052037
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
337 PM CDT Thu Jul 5 2018

ILZ058>060-064-065-069-070-074-079-095>102-MOZ061-063>065-073>075-
084-085-099-060015-
/O.CON.KLSX.HT.Y.0004.000000T0000Z-180706T0100Z/
Adams IL-Bond IL-Brown IL-Calhoun IL-Clinton IL-Fayette IL-
Greene IL-Iron MO-Jefferson MO-Jersey IL-Macoupin IL-Madison IL-
Madison MO-Marion IL-Monroe IL-Montgomery IL-Pike IL-Randolph IL-
Reynolds MO-Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Mount Sterling, 
Pittsfield, Quincy, Saint Charles, Saint Louis, Salem, Sparta, 
and Vandalia
337 PM CDT Thu Jul 5 2018

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM CDT THIS EVENING...

* TIMING...Heat index values of 105 and higher are likely during
  the afternoon and early evening

* HEAT INDEX VALUES...Up to 110 due to temperatures in the upper 
  90s, and dewpoints in the lower 70s.

* IMPACTS...The combination of hot temperatures and high 
  humidity will likely lead to an increased risk of heat- 
  related stress and illness. The very young, the elderly, those 
  without air conditioning, and those participating in strenuous 
  outdoor activities will be the most susceptible. Also, car 
  interiors can reach lethal temperatures in a matter of minutes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Heat Advisory means that a period of hot temperatures and high
humidity will occur. This combination will create a situation in
which heat-related illnesses are possible, especially for those
living in un-air conditioned homes or apartments. People in the
Advisory area are advised to avoid poorly ventilated areas and
prolonged work in the sun. Also, keep plenty of liquids on hand
and try to stay in an air conditioned environment.

Take extra precautions if you work or spend time outside. When
possible, reschedule strenuous activities to the early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear light weight and loose fitting clothing when
possible and drink plenty of water.

&&

$$

Kanofsky
519 
WWUS73 KLSX 060050
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
750 PM CDT Thu Jul 5 2018

ILZ058>060-064-065-069-070-074-079-095>102-MOZ061-063>065-073>075-
084-085-099-060200-
/O.EXP.KLSX.HT.Y.0004.000000T0000Z-180706T0100Z/
Adams IL-Bond IL-Brown IL-Calhoun IL-Clinton IL-Fayette IL-
Greene IL-Iron MO-Jefferson MO-Jersey IL-Macoupin IL-Madison IL-
Madison MO-Marion IL-Monroe IL-Montgomery IL-Pike IL-Randolph IL-
Reynolds MO-Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-
Washington IL-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Centralia, 
Chester, Edwardsville, Farmington, Litchfield, Mount Sterling, 
Pittsfield, Quincy, Saint Charles, Saint Louis, Salem, Sparta, 
and Vandalia
750 PM CDT Thu Jul 5 2018

...HEAT ADVISORY WILL EXPIRE AT 8 PM CDT THIS EVENING...

Temperatures have dropped into the 70s and 80s behind an outflow
boundary and thanks to earlier thunderstorms, therefore the Heat
Advisory will be allowed to expire.

$$

TES

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 Jul 3, 3:28 AM CDT, 3 minutes earlier.

Area forecast discussion, Jul 3, 3:28 AM CDT, 3 minutes before
Area Forecast Discussion
National Weather Service Saint Louis MO
328 AM CDT Tue Jul 3 2018

.SHORT TERM...  (Through Late Tonight)
Issued at 325 AM CDT Tue Jul 3 2018

The upper level high across the eastern CONUS will strengthen and
expand while a weak disturbance rides up the western flank of the
high. In the low levels, weak southerly flow will pick up a bit as
the high in the east intensifies. This will help usher warmer, more
moist air into eastern MO and western IL, and allow MLCAPE values to
build into the 1-1.5k J/kg range. This instability combined with the
lift provided by the subtle upper level shortwave should support
isolated to widely scattered storms in the afternoon. Stagnant flow
aloft will keep deep layer shear values quite low, really hampering
the chance for severe weather.

The current forecast shows heat indices just below 105, so we will
hold off a heat advisory for today.

BSH

.LONG TERM...  (Wednesday through Monday)
Issued at 325 AM CDT Tue Jul 3 2018

Fourth of July will be a hot and humid day for the region with highs
in the low to mid 90s and heat indices between 100 and 106. Areas
where the heat index value is 105+, mainly along and east of
Mississippi River, will issue a heat advisory beginning 17z
Wednesday and persist through 01z Friday.

On another note for the fourth, a back door cold front/vortmax to
slide northwestward around surface ridge. Despite weak shear,
have decent CAPES in excess of 2500 J/kg and plenty of low level
moisture, so will see scattered showers and storms develop by mid
morning. The bulk of the activity will be north of I-44 in
Missouri and I-70 in Illinois. This activity to slide northward
and move out/dissipate by late afternoon hours. So should see dry
conditions for the fireworks displays Wednesday night. Another
warm night with lows in the low to mid 70s.

By Thursday, cold front to slowly approach region and will see
chances of showers and storms move into northern portions of
forecast area. Some concern on how this will affect temps and heat
headlines. With slow movement of system, feel that area that is in
heat advisory to see plenty of sun, so highs to rise into the mid
90s with heat index values in excess of 105.

Precipitation chances to be on the increase by Friday as system
moves through exiting by Friday evening. As surface ridge builds in,
more pleasant temperatures to return to the region with highs Friday
through the weekend only in the mid to upper 80s. Dewpts to lower as
well, so less humid too.

By Monday upper ridge begins to build in as surface ridge slides off
to the east, so temps to begin to moderate. Highs will be in the
upper 80s to low 90s with low level moisture on the increase once
again.

Byrd
&&

.AVIATION...  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 632 PM CDT Mon Jul 2 2018

Main question overnight is how much cloud cover will remain and
therefore, how much, if any, fog will develop. With a moist
airmass in place, believe that most locations will see some light
fog develop overnight. KCOU currently has the best chance for
remaining VFR. Have added fog at other terminals late tonight into
Tues morning. Otherwise, winds will become sely on Tues. Ongoing
convection across OH Valley shud move NW into the area on Tues or
some version of it. Have kept VCTS going with isod to sct coverage
expected.

SPECIFICS FOR KSTL: Expect some MVFR fog to develop late tonight
into Tues morning. Winds will become sely Tues morning. Expect
isod to sct TSRA to develop during the late morning and afternoon
hours. Due to expected coverage, have kept VCTS going for now.

Tilly
&&

.PRELIMINARY POINT TEMPS/POPS...
Saint Louis     91  76  95  77 /  30  20  20   5
Quincy          90  74  92  75 /  20  10  30  10
Columbia        92  73  92  74 /  10   5  20   5
Jefferson City  92  75  93  74 /  20   5  20   5
Salem           90  74  93  74 /  40  10  10   0
Farmington      88  72  92  72 /  30  20  10   0

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory from noon Wednesday to 8 PM CDT Thursday for Iron
     MO-Jefferson MO-Madison MO-Reynolds MO-Saint Charles MO-
     Saint Francois MO-Saint Louis City MO-Saint Louis MO-Sainte
     Genevieve MO-Washington MO.

IL...Heat Advisory from noon Wednesday to 8 PM CDT Thursday for Bond
     IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-Saint Clair IL-Washington IL.

&&

WFO LSX
Hazardous weather outlook, Jul 2, 4:04 PM CDT, 11 hours 27 minutes before
Hazardous Weather Outlook
National Weather Service Saint Louis MO
404 PM CDT Mon Jul 2 2018

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-031200-
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 IL-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-
404 PM CDT Mon Jul 2 2018

This hazardous weather outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Tonight

No hazardous weather is expected.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Dangerous heat is possible from Tuesday through Friday.

There will be a chance of thunderstorms Tuesday through Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated through tonight.

Carney

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 3, 4:36 PM CDTSpecial Weather StatementLSXCalhoun39 min
Jul 3, 5:44 PM CDTSpecial Weather StatementLSXMadison46 min
Jul 3, 5:24 PM CDTSpecial Weather StatementLSXCity of Saint Louis51 min

Nearby

Heat Advisories in Missouri, 2018Heat Advisories in Illinois, 2018Every heat advisory in 2018

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.