Alert archive / Missouri / Winter Storm Warnings in 2019

Winter Storm Warning 2, NWS St. Louis, MO

January 18, 20197 counties in Missouri; Adams County, Brown County, Pike County, Illinois

NWS St. Louis, MO issued this winter storm warning at Jan 18, 2019, 2:45 AM CST for 7 counties in Missouri; Adams County, Brown County, Pike County, Illinois. It took effect at Jan 18, 2019, 3:00 PM CST. It was in force for 17 hr. 15 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jan 18, 2019, 2:45 AM CST (08:45 UTC)
In effect from
Jan 18, 2019, 3:00 PM CST
Expired
Jan 19, 2019, 7:52 AM CST
In force
17 hr
Issued by
NWS St. Louis, MO

Counties Adams County, IL, Brown County, IL, Pike County, IL, Knox County, MO, Lewis County, MO, Marion County, MO, Monroe County, MO, Pike County, MO, Ralls County, MO, Shelby County, MO

The radar

The St Louis radar (KLSX), 139 km from the middle of the area, began a volume at 08:45 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.

What was reported inside it

TimeReportWhereRemark
Jan 18, 10:07 PM CSTSNOW 2Lewistown, MO2 INCHES OF HEAVY WET SNOW IN LEWISTOWN.
Jan 18, 11:51 PM CSTSNOW 1Palmyra, MOROADWAYS COMPLETELY COVERED.
Jan 18, 11:51 PM CSTSNOW 2.3La Grange, MOROADS COMPLETELY COVERED.
Jan 18, 11:56 PM CSTSNOW 2.5Lewistown, MOTEMPERATURE AT 31. SNOW VERY LIGHT AT THE MOMENT.
Jan 19, 3:05 AM CSTSNOW 0.2Pittsfield, ILA MIX OF PRECIPITATION CHANGED TO ALL SNOW ABOUT AN HOUR AGO (2 A.M.), WITH LIGHT ACCUMULATIONS ON VEHICLES. ROADS REMAINED GENERALLY WET AND NOT SNOW-COVERED.
Jan 19, 3:40 AM CSTSNOW 0.7Hannibal, MOBETWEEN A HALF INCH AND AN INCH.
Jan 19, 3:40 AM CSTSNOW 2.4La Grange, MO
Jan 19, 3:55 AM CSTSNOW 2Shelbyville, MO1-2 INCHES ON GROUND WITH FLURRIES CURRENTLY FALLING.
Jan 19, 4:32 AM CSTFREEZING RAIN 0.1Paris, MOLITTLE OR NO SNOW AT PARIS WITH RAIN BEGINNING TO FREEZE IN SPOTS. ROADS ARE OKAY.
Jan 19, 4:43 AM CSTSNOW 0.2New London, MOMOSTLY RAIN OVERNIGHT IN RALLS COUNTY. ANY SNOW ACCUMULATION WOULD HAVE BEEN LESS THAN WHAT HANNIBAL RECEIVED. NO REPORTS OF ANY ACCIDENTS.
Jan 19, 4:51 AM CSTSNOW 0.21 Nw Bowling Green, MOROADS ARE FINE. ONLY A DUSTING OF LESS THAN A QUARTER INCH ON VEHICLES.
Jan 19, 4:53 AM CSTSNOW 0.5Quincy, ILNO TRAFFIC ISSUES.
Jan 19, 5:18 AM CSTSNOW 0.2Pittsfield, ILONLY A DUSTING OVERNIGHT, LESS THAN A QUARTER INCH.
Jan 19, 5:30 AM CSTHEAVY SNOW 4Lewistown, MOSTORM TOTAL SNOWFALL.
Jan 19, 5:30 AM CSTSNOW 4Lewistown, MOSTORM TOTAL SNOWFALL. CORRECTION TO EVENT TYPE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 8.8 hours before the alert went out and 222 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, Davenport, at 00:00Z on 2019-01-18Temperature 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, Davenport, at 00:00Z on 2019-01-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
511 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
66 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

968 
WWUS43 KLSX 180845
WSWLSX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Saint Louis MO
245 AM CST Fri Jan 18 2019


ILZ095>097-MOZ018-019-026-027-034>036-182045-
/O.UPG.KLSX.WS.A.0002.190118T2100Z-190120T0000Z/
/O.NEW.KLSX.WS.W.0002.190118T2100Z-190120T0000Z/
Adams IL-Brown IL-Knox MO-Lewis MO-Marion MO-Monroe MO-Pike IL-
Pike MO-Ralls MO-Shelby MO-
Including the cities of Bowling Green, Hannibal, Mount Sterling, 
Pittsfield, and Quincy
245 AM CST Fri Jan 18 2019

...WINTER STORM WARNING IN EFFECT FROM 3 PM THIS AFTERNOON TO
6 PM CST SATURDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 4 to 6
  inches expected. Winds gusting as high as 35 mph which will
  cause blowing and drifting.

* WHERE...Portions of northeast Missouri and west central 
  Illinois.

* WHEN...From 3 PM this afternoon to 6 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility. The 
  hazardous conditions could impact the evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means that heavy snowfall of
6 inches or more is expected. The rapid accumulation of snow will
make travel extremely difficult, if not impossible. If travel is
necessary, make sure to exercise extreme caution. Begin your
travel with a full tank of gas, and carry a winter storm kit
which includes a shovel, flashlight, cellphone, food and water,
and blankets of extra warm clothing. 

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information. 

&&

$$

ILZ058>060-064-065-098>102-MOZ041-042-047>052-059>065-072>075-
182045-
/O.NEW.KLSX.WW.Y.0003.190119T0600Z-190120T0000Z/
Audrain MO-Bond IL-Boone MO-Calhoun IL-Callaway MO-Cole MO-
Crawford MO-Fayette IL-Franklin MO-Gasconade MO-Greene IL-
Jefferson MO-Jersey IL-Lincoln MO-Macoupin IL-Madison IL-
Moniteau MO-Monroe IL-Montgomery IL-Montgomery MO-Osage MO-
Saint Charles MO-Saint Clair IL-Saint Francois MO-
Saint Louis City MO-Saint Louis MO-Sainte Genevieve MO-Warren MO-
Washington MO-
Including the cities of Alton, Belleville, Cahokia, Columbia, 
Edwardsville, Farmington, Fulton, Jefferson City, Litchfield, 
Mexico, Saint Charles, Saint Louis, Sullivan, Union, Vandalia, 
and Washington
245 AM CST Fri Jan 18 2019

...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
6 PM CST SATURDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 4 inches
  expected. Winds gusting as high as 35 mph which will cause blowing
  and drifting.

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

* WHEN...From midnight tonight to 6 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of
accumulating snow will primarily cause travel difficulties. Roads
may rapidly become slippery once the snow begins, so motorists
should plan for a slower than normal trip. Be especially alert
when approaching bridges, overpasses, and curves. 

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information. 

&&

$$

Byrd
3 follow-up statements
617 
WWUS43 KLSX 182054
WSWLSX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Saint Louis MO
254 PM CST Fri Jan 18 2019


ILZ095>097-MOZ018-019-026-027-034>036-190900-
/O.EXT.KLSX.WS.W.0002.190118T2100Z-190119T2100Z/
Adams IL-Brown IL-Knox MO-Lewis MO-Marion MO-Monroe MO-Pike IL-
Pike MO-Ralls MO-Shelby MO-
Including the cities of Bowling Green, Hannibal, Mount Sterling, 
Pittsfield, and Quincy
254 PM CST Fri Jan 18 2019

...WINTER STORM WARNING NOW IN EFFECT UNTIL 3 PM CST SATURDAY...

* WHAT...Heavy snow expected. Total snow accumulations of 4 to 6
  inches expected with locally higher amounts possible. Winds 
  gusting as high as 40 mph.

* WHERE...Portions of northeast Missouri and west-central 
  Illinois.

* WHEN...Until 3 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Areas 
  of blowing snow could significantly reduce visibility. The 
  hazardous conditions could impact the evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means that heavy snowfall of
6 inches or more is expected. The rapid accumulation of snow will
make travel extremely difficult, if not impossible. If travel is
necessary, make sure to exercise extreme caution. Begin your
travel with a full tank of gas, and carry a winter storm kit
which includes a shovel, flashlight, cellphone, food and water,
and blankets of extra warm clothing. 

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information. 

&&

$$

ILZ069-070-074-079-MOZ084-085-099-190900-
/O.EXB.KLSX.WW.Y.0003.190119T1200Z-190120T0300Z/
Clinton IL-Iron MO-Madison MO-Marion IL-Randolph IL-Reynolds MO-
Washington IL-
Including the cities of Centralia, Chester, Salem, and Sparta
254 PM CST Fri Jan 18 2019

...WINTER WEATHER ADVISORY IN EFFECT FROM 6 AM TO 9 PM CST
SATURDAY...

* WHAT...Snow expected. Total snow accumulations of 1 to 3 
  inches expected. Winds gusting as high as 35 mph.

* WHERE...Portions of southeast Missouri and south-central and 
  southwest Illinois.

* WHEN...From 6 AM to 9 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of
accumulating snow will primarily cause travel difficulties. Roads
may rapidly become slippery once the snow begins, so motorists
should plan for a slower than normal trip. Be especially alert
when approaching bridges, overpasses, and curves. 

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information. 

&&

$$

ILZ064-065-100>102-MOZ063>065-072>075-190900-
/O.EXT.KLSX.WW.Y.0003.190119T1200Z-190120T0300Z/
Bond IL-Crawford MO-Fayette IL-Jefferson MO-Madison IL-Monroe IL-
Saint Clair IL-Saint Francois MO-Saint Louis City MO-
Saint Louis MO-Sainte Genevieve MO-Washington MO-
Including the cities of Alton, Belleville, Cahokia, Edwardsville,
Farmington, Saint Louis, and Vandalia
254 PM CST Fri Jan 18 2019

...WINTER WEATHER ADVISORY NOW IN EFFECT FROM 6 AM TO 9 PM CST
SATURDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 4 inches
  expected with locally higher amounts possible. Winds gusting as
  high as 40 mph.

* WHERE...Portions of east-central and southeast Missouri and 
  south central and southwest Illinois.

* WHEN...From 6 AM to 9 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of
accumulating snow will primarily cause travel difficulties. Roads
may rapidly become slippery once the snow begins, so motorists
should plan for a slower than normal trip. Be especially alert
when approaching bridges, overpasses, and curves. 

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information. 

&&

$$

ILZ058>060-098-099-MOZ041-042-047>052-059>062-190900-
/O.CON.KLSX.WW.Y.0003.190119T0600Z-190120T0000Z/
Audrain MO-Boone MO-Calhoun IL-Callaway MO-Cole MO-Franklin MO-
Gasconade MO-Greene IL-Jersey IL-Lincoln MO-Macoupin IL-
Moniteau MO-Montgomery IL-Montgomery MO-Osage MO-Saint Charles MO-
Warren MO-
Including the cities of Columbia, Fulton, Jefferson City, 
Litchfield, Mexico, Saint Charles, Sullivan, Union, 
and Washington
254 PM CST Fri Jan 18 2019

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM MIDNIGHT
TONIGHT TO 6 PM CST SATURDAY...

* WHAT...Snow expected. Total snow accumulations of 2 to 4 inches
  expected with locally higher amounts possible. Winds gusting as
  high as 40 mph.

* WHERE...Portions of central and east-central Missouri and south
  central and southwest Illinois.

* WHEN...From midnight tonight to 6 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of
accumulating snow will primarily cause travel difficulties. Roads
may rapidly become slippery once the snow begins, so motorists
should plan for a slower than normal trip. Be especially alert
when approaching bridges, overpasses, and curves. 

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information. 

&&

$$

Gosselin
105 
WWUS43 KLSX 190936
WSWLSX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Saint Louis MO
336 AM CST Sat Jan 19 2019


ILZ095>097-MOZ018-019-026-027-034>036-192100-
/O.CON.KLSX.WS.W.0002.000000T0000Z-190119T2100Z/
Adams IL-Brown IL-Knox MO-Lewis MO-Marion MO-Monroe MO-Pike IL-
Pike MO-Ralls MO-Shelby MO-
Including the cities of Bowling Green, Hannibal, Mount Sterling, 
Pittsfield, and Quincy
336 AM CST Sat Jan 19 2019

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 3 PM CST THIS
AFTERNOON...

* WHAT...Heavy snow expected. Total snow accumulations of 2 to 5 
  inches expected with locally higher amounts possible. Winds 
  gusting as high as 40 mph.

* WHERE...Portions of northeast Missouri and west-central 
  Illinois.

* WHEN...Until 3 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Areas 
  of blowing snow could significantly reduce visibility. The 
  hazardous conditions could impact the evening commute.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means that heavy snowfall of
6 inches or more is expected. The rapid accumulation of snow will
make travel extremely difficult, if not impossible. If travel is
necessary, make sure to exercise extreme caution. Begin your
travel with a full tank of gas, and carry a winter storm kit
which includes a shovel, flashlight, cellphone, food and water,
and blankets of extra warm clothing.

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information.

&&

$$

ILZ058>060-098-099-MOZ041-042-047>052-059>062-192145-
/O.CON.KLSX.WW.Y.0003.000000T0000Z-190120T0000Z/
Audrain MO-Boone MO-Calhoun IL-Callaway MO-Cole MO-Franklin MO-
Gasconade MO-Greene IL-Jersey IL-Lincoln MO-Macoupin IL-
Moniteau MO-Montgomery IL-Montgomery MO-Osage MO-Saint Charles MO-
Warren MO-
Including the cities of Columbia, Fulton, Jefferson City, 
Litchfield, Mexico, Saint Charles, Sullivan, Union, 
and Washington
336 AM CST Sat Jan 19 2019

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 1 to 2 inches
  expected with locally higher amounts possible. Winds gusting as
  high as 40 mph.

* WHERE...Portions of central and east-central Missouri and 
  south central and southwest Illinois.

* WHEN...From midnight tonight to 6 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of
accumulating snow will primarily cause travel difficulties. Roads
may rapidly become slippery once the snow begins, so motorists
should plan for a slower than normal trip. Be especially alert
when approaching bridges, overpasses, and curves.

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information.

&&

$$

ILZ064-065-069-070-074-079-100>102-MOZ063>065-072>075-084-085-099-
192145-
/O.CON.KLSX.WW.Y.0003.190119T1200Z-190120T0300Z/
Bond IL-Clinton IL-Crawford MO-Fayette IL-Iron MO-Jefferson MO-
Madison IL-Madison MO-Marion IL-Monroe IL-Randolph IL-Reynolds 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, Saint Louis, Salem, Sparta, 
and Vandalia
336 AM CST Sat Jan 19 2019

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 PM CST THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 2 to 3 inches
  expected with locally higher amounts possible. Winds gusting as
  high as 40 mph.

* WHERE...Portions of east-central and southeast Missouri and 
  south central and southwest Illinois.

* WHEN...From 6 AM to 9 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of
accumulating snow will primarily cause travel difficulties. Roads
may rapidly become slippery once the snow begins, so motorists
should plan for a slower than normal trip. Be especially alert
when approaching bridges, overpasses, and curves.

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information.

&&

$$

Byrd
421 
WWUS43 KLSX 191352
WSWLSX

URGENT - WINTER WEATHER MESSAGE
National Weather Service Saint Louis MO
752 AM CST Sat Jan 19 2019


ILZ095>097-MOZ018-019-026-027-034>036-191500-
/O.CAN.KLSX.WS.W.0002.000000T0000Z-190119T2100Z/
Adams IL-Brown IL-Knox MO-Lewis MO-Marion MO-Monroe MO-Pike IL-
Pike MO-Ralls MO-Shelby MO-
Including the cities of Bowling Green, Hannibal, Mount Sterling, 
Pittsfield, and Quincy
752 AM CST Sat Jan 19 2019

...WINTER STORM WARNING IS CANCELLED...

Light snow has come to an end in the warning area with just some
lingering flurries, so the winter storm warning has been cancelled.
Still expect gusty north winds to 35 mph at times. Impacts from 
blowing snow are expected to be very limited.

$$

MOZ041-042-047-048-050-191500-
/O.CAN.KLSX.WW.Y.0003.000000T0000Z-190120T0000Z/
Audrain MO-Boone MO-Callaway MO-Cole MO-Moniteau MO-
Including the cities of Columbia, Fulton, Jefferson City, 
and Mexico
752 AM CST Sat Jan 19 2019

...WINTER WEATHER ADVISORY IS CANCELLED...

Light snow has come to an end in the advisory area with just some
lingering flurries, so the winter weather advisory has been 
cancelled. Still expect gusty north winds to 35 mph at times. 
Impacts from blowing snow are expected to be very limited.

$$

ILZ058>060-098-099-MOZ049-051-052-059>062-200000-
/O.CON.KLSX.WW.Y.0003.000000T0000Z-190120T0000Z/
Calhoun IL-Franklin MO-Gasconade MO-Greene IL-Jersey IL-
Lincoln MO-Macoupin IL-Montgomery IL-Montgomery MO-Osage MO-
Saint Charles MO-Warren MO-
Including the cities of Litchfield, Saint Charles, Sullivan, 
Union, and Washington
752 AM CST Sat Jan 19 2019

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 6 PM CST THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 1 to 2 
  inches expected with locally higher amounts possible. Winds 
  gusting as high as 40 mph.

* WHERE...Portions of central and east-central Missouri and 
  south central and southwest Illinois.

* WHEN...From midnight tonight to 6 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of
accumulating snow will primarily cause travel difficulties. Roads
may rapidly become slippery once the snow begins, so motorists
should plan for a slower than normal trip. Be especially alert
when approaching bridges, overpasses, and curves.

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information.

&&

$$

ILZ064-065-069-070-074-079-100>102-MOZ063>065-072>075-084-085-099-
200200-
/O.CON.KLSX.WW.Y.0003.000000T0000Z-190120T0300Z/
Bond IL-Clinton IL-Crawford MO-Fayette IL-Iron MO-Jefferson MO-
Madison IL-Madison MO-Marion IL-Monroe IL-Randolph IL-Reynolds 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, Saint Louis, Salem, Sparta, 
and Vandalia
752 AM CST Sat Jan 19 2019

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 PM CST THIS
EVENING...

* WHAT...Snow expected. Total snow accumulations of 2 to 3 
  inches expected with locally higher amounts possible. Winds 
  gusting as high as 40 mph.

* WHERE...Portions of east-central and southeast Missouri and 
  south central and southwest Illinois.

* WHEN...From 6 AM to 9 PM CST Saturday.

* ADDITIONAL DETAILS...Plan on slippery road conditions. Patchy 
  blowing snow could significantly reduce visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means that periods of
accumulating snow will primarily cause travel difficulties. Roads
may rapidly become slippery once the snow begins, so motorists
should plan for a slower than normal trip. Be especially alert
when approaching bridges, overpasses, and curves.

In Illinois, the latest road conditions can be obtained on the
Internet at www.gettingaroundillinois.com. In Missouri, call 1-
888-275-6636 for road information.

&&

$$

Byrd

What forecasters said that day

The local office's own words before this winter storm warning 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 winter storm warning went out at Jan 17, 11:23 PM CST, 3 hours 22 minutes earlier.

Area forecast discussion, Jan 17, 11:23 PM CST, 3 hours 22 minutes before
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1123 PM CST Thu Jan 17 2019

.SHORT TERM... (Through Late Saturday Night)
Issued at 231 PM CST Thu Jan 17 2019

(Tonight through Friday morning)

Focus this period will be primarily temps, but also potential for
fog development tonight.

The surface low and upper trof that brought yet another round of
frozen and freezing precip to the area continues to pull east
this afternoon. In the wake, a surface ridge continues to build
into the area. As it does, an upper level ridge will build into
the region. This setup will trap low level clouds under the
inversion across the region. As the surface ridge settles into the
area, winds are expected to become calm. With ample moisture in
the boundary layer, expect fog to develop once again tonight,
despite a lack of radiational cooling. Will hold off issuing any
headline for fog as confidence on how low visbys will drop and the
areal extent is too low at this point.

With the cloud cover expected to remain in place tonight and
tomorrow, do not expect a lot of diurnal temp change. That said,
tonight is expected to be slightly cooler simply due to the cooler
airmass building into the region. Have therefore trended just
below the warmer guidance for tonight. What fog does develop,
expect it to be slow to improve on Fri with temps slow to warm.
However, believe that the southeast flow will help conditions
improve slightly quicker compared to this morning.

Tilly

(Friday Afternoon - Saturday Night)

Very complicated and difficult forecast is ahead for the impending
winter storm.

Strong low-level warm/moist advection ahead of a lead vorticity
maxima should lead to a north-south axis of precipitation entering
the CWA by late afternoon. Pure rainfall is expected across central
and southern sections of the forecast area overnight Friday night,
with mainly snow across portions of northeast Missouri and west-
central Illinois. This is the part of the storm that has a fairly
high confidence, both in terms of precipitation type (rain/snow
line) and snowfall amounts. Further to the south and east, the
timing of the transition from rain to snow will be critical in
addition to the track/strength of the deformation zone on Saturday.

The rain/snow line should be near a KVIH>>KSTL>>K3LF axis by early
Saturday morning. The rain should continue to turn over to snow from
northwest to southeast through the day on Saturday, with anything
across the CWA falling as snow by the early afternoon hours. The
main source of uncertainty is how much snow will fall in areas after
the changeover from rain to snow.  Models have come into slightly
better agreement with respect to the evolution of shortwave trough
ejecting out of the south-central Plains. Most guidance is
suggesting the trough axis will attempt to become negatively tilted
along or just east of the Mississippi River. This helps increase the
forcing for large-scale ascent which leads to the low-level cyclone
to continue to deepen. Models almost seem to hint at a secondary 850-
hPa low forming just northwest of the Mississippi-Ohio River
confluence that tracks northeast into southeastern Indiana by
Saturday evening. A secondary axis of snow appears likely late
Saturday morning through the afternoon, but exactly where and more
importantly how strong this deformation zone will be are very open
questions. Isentropic surfaces only show a hint of a cyclonic
portion of the warm conveyor belt (TROWAL feature), with weak ascent
within this airstream. The weak ascent gives credence to the lower
snowfall amounts within the deformation zone. Regarding track of the
850-hPa low center, previous research by Browne and Younkin (1970)
would suggest this axis of snow just southeast of the I-44/I-70
corridors in Missouri and Illinois respectively. While latest (1200
UTC) model guidance is not as stout with this secondary axis of
snowfall, earlier guidance was and will depend heavily on how much
the mid/upper level trough axis is allowed to deepen. Given that the
system is not fully onshore yet, future deviations are still quite
possible.

By the time the storm exits Saturday evening, storm total snow
amounts across northern sections of the forecast area will be on the
order of 3-6". Because of the high confidence in several inches of
snow across this region and aggravating factors such as falling
temperatures and strong winds leading to blowing and drifting of
snow, went ahead and issued a winter storm watch for these
locations. Additional headline decisions will need to be made with
future forecast packages (potential for warnings/advisories) as
confidence in amounts and possible impacts come more into focus. A
general 1-3" is the most likely scenario for the remainder of the
CWA, with the strong caveat that a stronger deformation zone could
pose a risk for a few more inches of additional snowfall than
currently forecast. On the other side of the coin, if the
deformation zone is weaker and/or develops too far east, some
locations may end up with an inch or less. Continue to believe there
may be some kind of snowfall minimum south of where the warm air
advection snow falls and northwest of the track of the deformation
zone where rain does not change over to snow until Saturday morning.

The main story behind the winter storm will be the much colder air
that will come into the region. Low temperatures are forecast to
drop into the single digits to teens Saturday night, with coldest
wind chill readings between 0 and -10 across portions of northeast
Missouri and west-central Illinois.

Gosselin

.LONG TERM... (Sunday through Next Thursday)
Issued at 231 PM CST Thu Jan 17 2019

Cold moves in as high pressure sets up in place of the surface
low. Sunday morning will have the lowest temps so far this season
with lows dipping into the single digits in northern counties of
the CWA and teens elsewhere. Models are still having issues with
the placement of the high on Sunday and Monday resulting a wide
variance in low temps. The Euro is the outlier with temps 10-15
degrees colder than GFS and Canadian.

Next chance of precip moves into the area in the middle of next
week. A upper level trough moves in to the Midwest Tues/Wed.
There is poor agreement as to the timing of the surface low with
this system making it into the region as well as where it will
eventually set up. This is setting up to be some combination of a
rain and snow event with cold air moving in behind the low for a
portion of the precip to fall as snow.

Walsh

&&

.AVIATION...  (For the 06z TAFs through 06z Friday Night)
Issued at 1101 PM CST Thu Jan 17 2019

A surface ridge extending from eastern ND and MN south-southeast
through MO will move eastward late tonight and Friday. Surface
winds will be light late tonight. The stratus cloud deck ranging
from 600 feet in height in STL to 1900 feet in UIN will gradually
lower late tonight with fog developing due to the light wind and
moist surface/boundary layer aided by daytime melting of snow. The
lowest visibility will likely be in COU, possibly as low as
1/2-1SM late tonight/early Friday morning. The visibility will
improve late Friday morning as an easterly surface wind
strengthens due to a tightening surface pressure gradient as the
surface ridge shifts east of the area, while surface low pressure
deepens over the TX Panhandle region. The cloud ceiling will rise
to around 1000-1500 feet in the afternoon, then fall again Friday
evening. Light rain will spread eastward into COU and the St
Louis metro area Friday evening with light snow moving into UIN.

SPECIFICS FOR KSTL: A surface ridge extending from eastern ND
and MN south-southeast through MO will move eastward late tonight
and Friday. Surface winds will be light late tonight. The stratus
cloud deck at 600 feet in height will continue to lower late
tonight with fog developing due to the light wind and moist
surface/boundary layer aided by daytime melting of snow.
The visibility will improve late Friday morning as an easterly
surface wind strengthens due to a tightening surface pressure
gradient as the surface ridge shifts east of the area, while
surface low pressure deepens over the TX Panhandle region. The
cloud ceiling will rise to around 1000-1500 feet in the afternoon,
then fall again Friday night. Light rain will spread eastward
into STL Friday evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS...
Saint Louis     31  36  32  33 /   0  10 100  90
Quincy          25  31  26  27 /   0  40 100  70
Columbia        29  37  27  29 /   0  60 100  80
Jefferson City  29  38  28  30 /   0  40 100  80
Salem           31  37  36  37 /   0   5 100  90
Farmington      31  38  35  36 /   0  10 100  90

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Knox MO-Lewis MO-Marion MO-Monroe MO-Pike MO-
     Ralls MO-Shelby MO.

IL...Winter Storm Watch from Friday afternoon through Saturday
     afternoon for Adams IL-Brown IL-Pike IL.

&&

WFO LSX
Hazardous weather outlook, Jan 17, 3:00 PM CST, 11 hours 45 minutes before
Hazardous Weather Outlook
National Weather Service Saint Louis MO
300 PM CST Thu Jan 17 2019

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-181200-
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 IL-Saint Francois MO-Saint Louis City MO-Saint Louis MO-
Sainte Genevieve MO-Shelby MO-Warren MO-Washington IL-Washington MO-
300 PM CST Thu Jan 17 2019

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

.DAY ONE...This afternoon and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Another round of accumulating snow is expected areawide for Friday
night through Saturday night, with significant accumulations
possible. Please refer to the Winter Storm Watch for more
information.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated through tonight.

Tilly

The office that day

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

IssuedProductOfficeCountiesLasted
Jan 18, 2:45 AM CSTWinter Weather AdvisoryLSXAudrain, Boone, Callaway, Cole, Crawford, Franklin and 16 more41 hr

Nearby

Winter Storm Warnings in Missouri, 2019Winter Storm Warnings in Illinois, 2019Every winter storm warning in 2019

Sources

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