Alert archive / Missouri / Frost Advisories in 2018

Frost Advisory 2, NWS St. Louis, MO

April 19, 20189 counties in Illinois; 21 counties in Missouri

NWS St. Louis, MO issued this frost advisory at Apr 19, 2018, 2:46 AM CDT for 9 counties in Illinois; 21 counties in Missouri. It took effect at Apr 20, 2018, 1:00 AM CDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Apr 19, 2018, 2:46 AM CDT (07:46 UTC)
In effect from
Apr 20, 2018, 1:00 AM CDT
Expired
Apr 20, 2018, 9:00 AM CDT
In force
8 hr
Issued by
NWS St. Louis, MO
All 30 counties

Bond County, IL, Calhoun County, IL, Clinton County, IL, Jersey County, IL, Madison County, IL, Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, 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, Lincoln County, MO, Madison County, MO, Moniteau County, MO, Montgomery County, MO, Osage County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 30 km from the middle of the area, began a volume at 07:49 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, 7.8 hours before the alert went out and 267 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 2018-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2018-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -74 square meters per square second.1939587897117Sfc1 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
783 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
-74 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

181 
WWUS73 KLSX 190746
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
246 AM CDT Thu Apr 19 2018

ILZ065-070-192115-
/O.NEW.KLSX.FZ.W.0007.180420T0600Z-180420T1400Z/
Fayette IL-Marion IL-
Including the cities of Centralia, Salem, and Vandalia
246 AM CDT Thu Apr 19 2018

...FREEZE WARNING IN EFFECT FROM 1 AM TO 9 AM CDT FRIDAY...

The National Weather Service in Saint Louis has issued a Freeze
Warning, which is in effect from 1 AM to 9 AM CDT Friday.

* TIMING...Late tonight and early Friday morning.

* TEMPERATURES...Low temperatures will be 30 to 32 degrees.

* IMPACTS...Sensitive plants and trees may be damaged or killed.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Freeze Warning means sub-freezing temperatures are imminent or
highly likely. These conditions will kill crops and other
sensitive vegetation.

&&

$$

ILZ064-069-074-079-098>102-MOZ041-047>052-059>065-072>075-084-085-
099-192115-
/O.NEW.KLSX.FR.Y.0002.180420T0600Z-180420T1400Z/
Bond IL-Boone MO-Calhoun IL-Callaway MO-Clinton IL-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Jersey IL-Lincoln MO-Madison IL-Madison MO-Moniteau MO-Monroe IL-
Montgomery MO-Osage MO-Randolph IL-Reynolds MO-Saint Charles MO-
Saint Clair IL-Saint Francois MO-Saint Louis City MO-
Saint Louis MO-Sainte Genevieve MO-Warren MO-Washington IL-
Washington MO-
Including the cities of Alton, Belleville, Cahokia, Chester, 
Columbia, Edwardsville, Farmington, Fulton, Jefferson City, 
Saint Charles, Saint Louis, Sparta, Sullivan, Union, 
and Washington
246 AM CDT Thu Apr 19 2018

...FROST ADVISORY IN EFFECT FROM 1 AM TO 9 AM CDT FRIDAY...

The National Weather Service in Saint Louis has issued a Frost
Advisory, which is in effect from 1 AM to 9 AM CDT Friday.

* TIMING...Late tonight and early Friday morning.

* TEMPERATURES...Low temperatures will be in the lower to mid 30s.

* IMPACTS...Sensitive plants and trees may be damaged or killed.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that widespread frost is expected. Those
with agricultural interests in the Advisory area should protect
tender vegetation. Also, potted plants normally left outdoors
should be covered or brought inside away from the cold.

&&

$$

Britt
3 follow-up statements
666 
WWUS73 KLSX 192018
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
318 PM CDT Thu Apr 19 2018


ILZ065-070-200900-
/O.CON.KLSX.FZ.W.0007.180420T0600Z-180420T1400Z/
Fayette IL-Marion IL-
Including the cities of Centralia, Salem, and Vandalia
318 PM CDT Thu Apr 19 2018

...FREEZE WARNING REMAINS IN EFFECT FROM 1 AM TO 9 AM CDT
FRIDAY...

* TIMING...Late tonight and early Friday morning.

* TEMPERATURES...Dropping to around 30 degrees.

* IMPACTS...Sensitive plants and trees may be damaged or killed.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Freeze Warning means sub-freezing temperatures are imminent or
highly likely. These conditions will kill crops and other
sensitive vegetation.

&&

$$

ILZ064-069-074-079-098>102-MOZ041-047>052-059>065-072>075-084-085-
099-200900-
/O.CON.KLSX.FR.Y.0002.180420T0600Z-180420T1400Z/
Bond IL-Boone MO-Calhoun IL-Callaway MO-Clinton IL-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Jersey IL-Lincoln MO-Madison IL-Madison MO-Moniteau MO-Monroe IL-
Montgomery MO-Osage MO-Randolph IL-Reynolds MO-Saint Charles MO-
Saint Clair IL-Saint Francois MO-Saint Louis City MO-
Saint Louis MO-Sainte Genevieve MO-Warren MO-Washington IL-
Washington MO-
Including the cities of Alton, Belleville, Cahokia, Chester, 
Columbia, Edwardsville, Farmington, Fulton, Jefferson City, 
Saint Charles, Saint Louis, Sparta, Sullivan, Union, 
and Washington
318 PM CDT Thu Apr 19 2018

...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 9 AM CDT
FRIDAY...

* TIMING...Late tonight and early Friday morning.

* TEMPERATURES...Dropping to 32 to 35 degrees.

* IMPACTS...Sensitive plants and trees may be damaged or killed.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that widespread frost is expected. Those
with agricultural interests in the Advisory area should protect
tender vegetation. Also, potted plants normally left outdoors
should be covered or brought inside away from the cold.

&&

$$

GKS
629 
WWUS73 KLSX 200904
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
404 AM CDT Fri Apr 20 2018


ILZ065-070-201400-
/O.CON.KLSX.FZ.W.0007.000000T0000Z-180420T1400Z/
Fayette IL-Marion IL-
Including the cities of Centralia, Salem, and Vandalia
404 AM CDT Fri Apr 20 2018

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM CDT THIS MORNING...

* TIMING...Early this morning.

* TEMPERATURES...In the lower 30s.

* IMPACTS...Sensitive plants and trees may be damaged or killed.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Freeze Warning means sub-freezing temperatures are imminent or
highly likely. These conditions will kill crops and other
sensitive vegetation.

&&

$$

ILZ064-069-074-079-098>102-MOZ041-047>052-059>065-072>075-084-085-
099-201400-
/O.CON.KLSX.FR.Y.0002.000000T0000Z-180420T1400Z/
Bond IL-Boone MO-Calhoun IL-Callaway MO-Clinton IL-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Jersey IL-Lincoln MO-Madison IL-Madison MO-Moniteau MO-Monroe IL-
Montgomery MO-Osage MO-Randolph IL-Reynolds MO-Saint Charles MO-
Saint Clair IL-Saint Francois MO-Saint Louis City MO-
Saint Louis MO-Sainte Genevieve MO-Warren MO-Washington IL-
Washington MO-
Including the cities of Alton, Belleville, Cahokia, Chester, 
Columbia, Edwardsville, Farmington, Fulton, Jefferson City, 
Saint Charles, Saint Louis, Sparta, Sullivan, Union, 
and Washington
404 AM CDT Fri Apr 20 2018

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM CDT THIS MORNING...

* TIMING...Early this morning.

* TEMPERATURES...In the mid 30s.

* IMPACTS...Sensitive plants and trees may be damaged or killed.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that widespread frost is expected. Those
with agricultural interests in the Advisory area should protect
tender vegetation. Also, potted plants normally left outdoors
should be covered or brought inside away from the cold.

&&

$$

Maples
784 
WWUS73 KLSX 201411
NPWLSX

URGENT - WEATHER MESSAGE
National Weather Service Saint Louis MO
911 AM CDT Fri Apr 20 2018

ILZ065-070-201515-
/O.EXP.KLSX.FZ.W.0007.000000T0000Z-180420T1400Z/
Fayette IL-Marion IL-
Including the cities of Centralia, Salem, and Vandalia
911 AM CDT Fri Apr 20 2018

...FREEZE WARNING HAS EXPIRED...

Temperatures have risen above the freezing mark this morning.

$$

ILZ064-069-074-079-098>102-MOZ041-047>052-059>065-072>075-084-085-
099-201515-
/O.EXP.KLSX.FR.Y.0002.000000T0000Z-180420T1400Z/
Bond IL-Boone MO-Calhoun IL-Callaway MO-Clinton IL-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Jersey IL-Lincoln MO-Madison IL-Madison MO-Moniteau MO-Monroe IL-
Montgomery MO-Osage MO-Randolph IL-Reynolds MO-Saint Charles MO-
Saint Clair IL-Saint Francois MO-Saint Louis City MO-
Saint Louis MO-Sainte Genevieve MO-Warren MO-Washington IL-
Washington MO-
Including the cities of Alton, Belleville, Cahokia, Chester, 
Columbia, Edwardsville, Farmington, Fulton, Jefferson City, 
Saint Charles, Saint Louis, Sparta, Sullivan, Union, 
and Washington
911 AM CDT Fri Apr 20 2018

...FROST ADVISORY HAS EXPIRED...

Temperatures have risen well above the freezing mark this 
morning and frost has melted or evaporated.

$$

GKS

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 19, 2:46 AM CDTFreeze WarningLSXFayette, Marion30 hr

Nearby

Frost Advisories in Missouri, 2018Frost Advisories in Illinois, 2018Every frost 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.