Special Weather Statement, NWS Paducah, KY

Area Forecast Discussion
National Weather Service Paducah KY
657 AM CDT Sat Jul 31 2021

.UPDATE...
Issued at 656 AM CDT Sat Jul 31 2021

Updated aviation discussion for 12Z TAFs.

&&

.SHORT TERM...(Today through Monday night)
Issued at 344 AM CDT Sat Jul 31 2021

The primary forecast challenge in the near term is the potential
for showers and thunderstorms through tonight as energy rides
southeast along a frontal boundary stalled across the area.
Forecast confidence is relatively high in the short term, but is
least certain in the first 24 hours given the wide span of
potential convective outcomes today and tonight.

Showers and thunderstorms extended from Nebraska into southern
Iowa and northern Missouri early this morning. This activity is
forecast to continue its southeastward progress through the
morning, likely impacting northern portions of the region, namely
southern Illinois and southwest Indiana, before noon. CAM model
output suggests this activity should gradually weaken with time
as the atmosphere remains relatively stable beneath substantial
cloud cover.

However, substantial warming is anticipated south of the cirrus
shield, which may roughly correspond to the approximate location
of the stalled frontal boundary. This will make for a very large
temperature gradient across the region by afternoon, with a span
of 20 degrees or more from northeast to southwest. The resultant
differential heating should contribute to at least moderate
destabilization in the warm sector, and new storm development
appears likely in close proximity to the warm sector during the
mid to late afternoon as mid level energy approaches. The coverage
of activity should peak during the evening hours before tapering
off from north to south overnight.

Some of the thunderstorms that develop in and near the warm
sector this afternoon and evening may be strong to severe,
especially across portions of southeast Missouri, far western
Kentucky, and extreme southern Illinois. This is highlighted in
the Storm Prediction Center's Day 1 Marginal risk. Also with
precipitable water values in excess of 2 inches, periods of heavy
rain may result in localized flooding, which could be exacerbated
by repeat rounds of thunderstorm activity. Consequently, much of
southern Illinois, southeast Missouri, and western Kentucky is
in a Slight risk of exceeding flash flood guidance in WPC's Day 1
Excessive Rainfall Outlook.

After a lingering small chance of showers early Sunday morning,
mainly dry weather will be accompanied by cooler and substantially
less humid conditions as high pressure takes hold through Monday
night. There is a small chance that a few showers may form Sunday
afternoon as cooler air aloft rotates into the region, but that
chance is low enough at this point to keep its mention out of the
forecast.

With one more hot and humid day in portions of southeast Missouri,
will continue the Heat Advisory for Carter, Ripley, and Butler
counties today, while removing Wayne, Stoddard, and New Madrid
counties. Highs today should range from the middle to upper 70s
along Interstate 64 in southeast Illinois and southwest Indiana to
the middle 90s in the Heat Advisory area. Highs Sunday and Monday
should range from around 80 into the lower 80s. Lows are forecast
to drop into the upper 50s to lower 60s both Sunday and Monday
nights.

.LONG TERM...(Tuesday through Friday)
Issued at 344 AM CDT Sat Jul 31 2021

Deterministic and ensemble mean guidance shows some semblance of an
upper trof will be over the east 1/2 of the nation in the long term,
weakening with time. Surface high pressure should be the dominant
feature, though it will shift farther east by the end of the week,
with some return flow setting up. The end result should be
temperatures a bit below normal and mainly dry weather. Temperatures
will moderate through the end of the week as the high loses its
influence. There is a weak signal for convection late Friday into
Saturday.

&&

.AVIATION...
Issued at 656 AM CDT Sat Jul 31 2021

Showers and scattered thunderstorms are forecast today into
tonight. Two rounds may impact northern sections (KMVN/KEVV/KOWB)
later this morning into early afternoon, then possibly again by
late afternoon and early evening. Southern sections (KCGI/KPAH)
should see most of the activity late this afternoon into tonight.
Ceilings and visibilities will be mainly VFR today, but may
decrease to MVFR for some time tonight. Winds will be light and
variable today, except gusty near thunderstorms, then become more
northerly by tonight.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...Heat Advisory until 6 PM CDT this evening for MOZ107>109.

IN...None.
KY...None.
&&

UPDATE...RJP
SHORT TERM...RJP
LONG TERM...08
AVIATION...RJP

Hazardous Weather Outlook
National Weather Service Paducah KY
414 AM CDT Sat Jul 31 2021

ILZ075>078-080>094-INZ081-082-085>088-KYZ001>022-MOZ076-086-087-
100-107>112-114-010915-
Jefferson-Wayne IL-Edwards-Wabash-Perry IL-Franklin-Hamilton-
White-Jackson-Williamson-Saline-Gallatin-Union-Johnson-Pope-
Hardin-Alexander-Pulaski-Massac-Gibson-Pike-Posey-Vanderburgh-
Warrick-Spencer-Fulton-Hickman-Carlisle-Ballard-McCracken-Graves-
Livingston-Marshall-Calloway-Crittenden-Lyon-Trigg-Caldwell-
Union KY-Webster-Hopkins-Christian-Henderson-Daviess-McLean-
Muhlenberg-Todd-Perry MO-Bollinger-Cape Girardeau-Wayne MO-Carter-
Ripley-Butler-Stoddard-Scott-Mississippi-New Madrid-
414 AM CDT Sat Jul 31 2021

This Hazardous Weather Outlook is for portions of southern
Illinois, southwest Indiana, western Kentucky, and southeast
Missouri.

.DAY ONE...Today and Tonight

Scattered thunderstorms are forecast today into tonight. The
strongest storms are expected to be mainly along and west of a
line from Carbondale Illinois to Hopkinsville Kentucky, where a
few strong to severe storms and localized flooding are possible.
The best coverage of thunderstorm activity should span from late
this afternoon into tonight.

A Heat Advisory remains in effect for a small part of southeast
Missouri from Poplar Bluff westward today. Refer to the advisory
product for details.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated at this time.

RJP/08

Special Weather Statement
National Weather Service Paducah KY
1148 AM CDT Sat Jul 31 2021

ILZ092-MOZ076-086-087-100-109>111-311730-
Alexander IL-Butler MO-Stoddard MO-Wayne MO-Bollinger MO-
Cape Girardeau MO-Scott MO-Perry MO-
1148 AM CDT Sat Jul 31 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN ALEXANDER...
BOLLINGER...NORTHWESTERN SCOTT...SOUTHWESTERN PERRY...WAYNE...
NORTHERN STODDARD...NORTH CENTRAL BUTLER AND CAPE GIRARDEAU COUNTIES
UNTIL 1230 PM CDT...

At 1147 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles south of Perryville to near Patton to
near Saco. Movement was southeast at 35 mph.

Half inch hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Cape Girardeau, Jackson, Scott City, Chaffee, Marble Hill, Advance,
Oran, Sam A. Baker State Park, Bollinger Mill State Historic Site,
Greenville, Lake Wappapello State Park, Puxico, Kelso, Bell City,
Delta, Gordonville, Williamsville, Dutchtown, Millersville and Lodi.

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.

&&

LAT...LON 3727 9055 3732 9055 3731 9015 3743 9015
      3771 8997 3736 8943 3734 8948 3733 8945
      3701 8965 3691 9060 3727 9067
TIME...MOT...LOC 1647Z 315DEG 29KT 3764 8991 3740 9006 3737 9050

PS

Special Weather Statement
National Weather Service Paducah KY
149 PM CDT Sat Jul 31 2021

KYZ001-MOZ109-110-114-311930-
Fulton KY-Butler MO-Stoddard MO-New Madrid MO-
149 PM CDT Sat Jul 31 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN FULTON...NEW
MADRID...SOUTHERN STODDARD AND BUTLER COUNTIES UNTIL 230 PM CDT...

At 149 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Canalou to near Milltown. Movement was
southeast at 30 mph.

Penny size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Poplar Bluff, Dexter, Portageville, New Madrid, Bernie, Lilbourn,
Hunter-Dawson State Historic Site, Malden, Clarkton, Gideon, Parma,
Marston, Neelyville, Qulin, Howardville, Risco, Fisk, Canalou, Dudley
and Milltown.

LAT...LON 3640 8959 3640 8967 3643 8972 3639 8975
      3639 8997 3663 8996 3663 9015 3650 9022
      3650 9049 3680 9063 3678 8965 3650 8940
      3646 8946 3647 8950 3650 8949 3650 8954
      3646 8952 3643 8955 3637 8951 3634 8954
TIME...MOT...LOC 1849Z 330DEG 25KT 3673 8971 3674 9052

PS