Special Weather Statement, NWS St. Louis, MO

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1213 PM CDT Wed Jun 26 2019

.SHORT TERM...  (Through Late Tonight)
Issued at 326 AM CDT Wed Jun 26 2019

CAMS like the HRRR depict at least widely scattered diurnal
convection developing this afternoon with the best coverage
across southeast MO as the atmosphere becomes unstable with
daytime heating and as an MCV approaches from the decaying MCS
over southwest MO early this morning. This convection should
dissipate by late evening. The NAM model drops an MCS southeastward
through northeast MO and IL late this afternoon and evening,
while the 4 km NAM Nest is a little slower and further west with
its MCS. Not real confident with the NAM solutions, but would not
be surprised to see isolated to scattered showers/storms late
this afternoon and early this evening across central and southeast
MO and southwest IL. Slightly warmer and more humid conditions
can be expected today and tonight as upper level heights gradually
rise with south-southwest surface/low level winds.

GKS

.LONG TERM...  (Thursday through Tuesday)
Issued at 326 AM CDT Wed Jun 26 2019

Thursday and Thursday night appear dry at this time as upper level
ridging builds over MO and IL with continued southerly surface winds
as the synoptic boundary remains well north of our forecast area.
Daytime highs may be slightly warmer compared to Wednesday,
although it appears that we will be getting into a typical
Summertime weather pattern with persistent temperatures generally
slightly above normal for late June. The NAM model continues dry
for our area with the exception of an MCS dropping south-
southwestward into northeast MO and west central IL late Friday
night as it forecasts a back-door type cold front approaching our
area as a surface ridge builds into the Great Lakes region.
Difficult to forecast location and timing of an MCS that far out
in time so do not have a lot of confidence in this solution,
especially since the operational GFS or ECMWF model does not
forecast a similar backdoor front. The weekend looks mainly dry
with the mid-upper level ridge centered over Iowa and northern
MO. The chance of convection will increase by Tuesday as the
upper level ridge shifts east of our area and as a mid-upper
level trough approaches western MO on Tuesday.

GKS

&&

.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1151 AM CDT Wed Jun 26 2019

SPECIFICS FOR KCOU, KUIN: A remnant thunderstorm complex over
southwestern MO was moving very slowly eastward at TAF issuance.
This feature will support scattered SHRA/TSRA from around 26/21z
through around 27/02z, but it is unclear whether SHRA/TSRA will
extend far enough northward to affect KCOU. Similar concerns exist
for KUIN due to a separate remnant thunderstorm complex which was
located over extreme northwestern MO at TAF issuance. Otherwise,
expect diurnal cumulus and light southerly to southwesterly winds.

SPECIFICS FOR KSTL, KSUS, KCPS: VFR conditions are expected for
the first 0-3 hours of the valid TAF period, but uncertainty
increases after 21z. A remnant thunderstorm complex over
southwestern MO was moving very slowly eastward at TAF issuance,
and while it is expected to generate additional thunderstorms
this afternoon, it is unclear how far north the convection might
spread. VCTS from 26/21z - 27/02z seems appropriate at this time
until the northern extent of the convection has been established.
Otherwise, light southerly to southwesterly winds will persist
through the period.

Kanofsky

&&

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

WFO LSX

Hazardous Weather Outlook
National Weather Service Saint Louis MO
414 AM CDT Wed Jun 26 2019

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-270915-
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-
414 AM CDT Wed Jun 26 2019

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.

There is a chance of thunderstorms this afternoon and early this
evening. A few storms may become strong with small hail and strong
gusty winds.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

There is a slight chance of thunderstorms across southeast Missouri
and southwest Illinois on Thursday. There is also a slight chance of
thunderstorms across portions of our area both Monday and Tuesday
afternoons.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated through tonight.

GKS

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
226 PM CDT WED JUN 26 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0219 PM     HAIL             1 W UNION               38.45N 91.03W
06/26/2019  M0.25 INCH       FRANKLIN           MO   PUBLIC

            REPORTED AT UNION HIGH SCHOOL: PEA SIZED
            HAIL.

&&

MRB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
227 PM CDT WED JUN 26 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0224 PM     HEAVY RAIN       2 NE FRENCH VILLAGE     37.99N 90.36W
06/26/2019  M0.90 INCH       ST. FRANCOIS       MO   PUBLIC

            SPOTTER REMARKED THAT TEMPERATURE DROPPED 20
            DEGREES IN THAT TIME.

&&

MRB

Special Weather Statement
National Weather Service St Louis MO
229 PM CDT Wed Jun 26 2019

ILZ058-098-MOZ036-052-060>063-065-073-262000-
Calhoun IL-Greene IL-Pike MO-St. Louis MO-St. Charles MO-
Washington MO-Jefferson MO-Franklin MO-Lincoln MO-Warren MO-
229 PM CDT Wed Jun 26 2019

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL CALHOUN AND SOUTHWESTERN
GREENE COUNTIES IN SOUTHWESTERN ILLINOIS...WESTERN ST. CHARLES...
EASTERN LINCOLN...NORTHWESTERN JEFFERSON...NORTHWESTERN WASHINGTON...
EASTERN FRANKLIN...WEST CENTRAL ST. LOUIS...SOUTHEASTERN WARREN
COUNTIES IN EAST CENTRAL MISSOURI AND EASTERN PIKE COUNTIES IN
NORTHEASTERN MISSOURI UNTIL 300 PM CDT...

At 228 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Elsberry to Wright City to near Miramiguoa
Park. Movement was east at 25 mph.

Nickel size hail and wind gusts of 50 to 55 mph will be possible with
these storms.

Locations impacted include...
O'Fallon, Wildwood, Wentzville, Lake St. Louis, Washington, Dardenne
Prairie, Troy, Union, Pacific, St. Clair, Wright City, Elsberry, St.
Paul, Gray Summit, Villa Ridge, Moscow Mills, Winfield, Marthasville,
Hardin and Innsbrook.

This includes the following highways...
 Interstate 44 in Missouri between exits 239 and 257.
 Interstate 70 in Missouri between exits 199 and 216.

This also includes Cuivre River State Park and Robertsville State
Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3932 9050 3892 9070 3818 9072 3812 9109
      3881 9109 3925 9083
TIME...MOT...LOC 1928Z 247DEG 21KT 3922 9078 3884 9100 3822 9101

Britt

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
302 PM CDT WED JUN 26 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0257 PM     HAIL             2 SSW BALLWIN           38.57N 90.56W
06/26/2019  E0.25 INCH       ST. LOUIS          MO   PUBLIC

&&

MF

Special Weather Statement
National Weather Service St Louis MO
305 PM CDT Wed Jun 26 2019

ILZ058-098-099-MOZ036-052-262045-
Calhoun IL-Greene IL-Jersey IL-Pike MO-Lincoln MO-
305 PM CDT Wed Jun 26 2019

...SIGNIFICANT WEATHER ADVISORY FOR CALHOUN...SOUTHWESTERN GREENE AND
WEST CENTRAL JERSEY COUNTIES IN SOUTHWESTERN ILLINOIS...NORTHEASTERN
LINCOLN COUNTY IN EAST CENTRAL MISSOURI AND SOUTHEASTERN PIKE
COUNTIES IN NORTHEASTERN MISSOURI UNTIL 345 PM CDT...

At 305 PM CDT, Doppler radar was tracking a strong thunderstorm near
Eolia, moving southeast at 20 mph.

Nickel size hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Elsberry, Winfield, Hardin, Eolia, Clarksville, Belleview,
Kampsville, Batchtown, Eldred, Foley, Hamburg, Paynesville,
Whiteside, Annada, Edgewood, Mozier, Woody, Cyrene, Michael and New
Hope.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3941 9096 3941 9095 3940 9094 3940 9083
      3925 9040 3894 9073 3928 9114 3942 9097
TIME...MOT...LOC 2005Z 303DEG 16KT 3927 9093

Britt

Special Weather Statement
National Weather Service St Louis MO
311 PM CDT Wed Jun 26 2019

ILZ100>102-MOZ061-063>065-262045-
St. Clair IL-Madison IL-Monroe IL-St. Louis MO-St. Charles MO-
Jefferson MO-St. Louis City MO-
311 PM CDT Wed Jun 26 2019

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MONROE...
SOUTHWESTERN MADISON AND NORTHWESTERN ST. CLAIR COUNTIES IN
SOUTHWESTERN ILLINOIS...NORTH CENTRAL ST. CHARLES...NORTHEASTERN
JEFFERSON AND ST. LOUIS COUNTIES IN EAST CENTRAL MISSOURI AND ST.
LOUIS CITY UNTIL 345 PM CDT...

At 310 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Ballwin to Sappington. Movement was
northeast at 15 mph.

Nickel size hail and wind gusts of 50 to 55 mph will be possible with
these storms.

Locations impacted include...
St. Louis, St. Charles, Florissant, Chesterfield, Belleville,
Wildwood, University City, Ballwin, Granite City, Kirkwood, Maryland
Heights, East St. Louis, Hazelwood, Collinsville, Webster Groves,
Ferguson, Arnold, Manchester, Creve Coeur and Fairview Heights.

This includes the following highways...
 Interstate 64 in Illinois between exits 9 and 12.
 Interstate 44 in Missouri between exits 272 and 277.
 Interstate 55 in Missouri between exits 190 and 191.
 Interstate 70 in Missouri between exits 228 and 231.

This also includes Scott Joplin Historic Site and First Missouri
State Capitol Historic Site.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3893 9040 3860 8998 3840 9037 3862 9065
TIME...MOT...LOC 2010Z 224DEG 13KT 3862 9053 3850 9038

Britt