Severe Thunderstorm Warning 188, NWS St. Louis, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
1238 PM CDT SUN APR 16 2006

.UPDATE...
TOR WATCH HAS BEEN ISSUED FOR ANTICIPATED SEVERE WX EVENT THIS
AFTERNOON...WITH GREATEST TOR POTENTIAL TO THE N OF KSTL...TOWARDS
THE WRMFNT IN CNTRL IL. OTHERWISE...FORECAST LOOKS TO BE IN GOOD SHAPE
AND ONLY MADE MINOR ADJUSTMENTS...PRIMARILY TO SKY CONDITIONS.

TES

&&

.DISCUSSION...
A WARM SUNNY SUNDAY MORNING ACROSS CWA AS MAIN RAIN SHIELD HAS
LIFTED NORTHEAST INTO WESTERN GREAT LAKES REGION...PLACING MUCH OF
OUR AREA IN THE DRY SLOT AND WARM SECTOR.

STACKED LOW PRESSURE SYSTEM CURRENTLY IN SOUTHWEST IOWA WILL MOVE TO
CENTRAL ILLINOIS TODAY. DOUBLE WARM FRONT STRUCTURE CURRENTLY LAYED
OUT ACROSS MISSOURI AND ILLINOIS WILL LIFT THROUGH CENTRAL ILLINOIS
LATER THIS MORNING AS DRYLINE/COLD FRONT CONTINUES TO HEAD EAST
ACROSS WESTERN MISSOURI.

SPC HAS PLACED THE MAJORITY OF THE CWA IN A SLIGHT RISK TODAY...WITH
THE HIGHEST RISK OF SEVERE WEATHER FALLING ALONG AND EAST OF THE
MISSISSIPPI RIVER WHERE SURFACE HEATING WILL COMBINE WITH DEWPOINTS
IN THE LOWER 60S TO CREATE MLCAPES BETWEEN 2000-2500 J/KG BY EARLY
AFTERNOON. DEEP LAYER SHEAR SHOULD SUPPORT SUPERCELLS AS
THUNDERSTORMS DEVELOP ACROSS EASTERN MISSOURI DURING THE EARLY
AFTERNOON. BACKED WINDS NEAR SURFACE LOW AND LIFTING WARM FRONT WILL
ENHANCE THE THREAT FOR TORNADOES ACROSS ILLINOIS...AND STEEP LAPSE
RATES IN CONJUCTION WITH UPPER LOW WILL SUPPORT A THREAT FOR VERY
LARGE HAIL. MODE OF CONVECTION SHOULD BECOME MORE LINEAR BY LATE
AFTERNOON AS DRYLINE/COLD FRONT AND LOW PRESSURE MOVE INTO CENTRAL
ILLINOIS.

CLOUDS HANG AROUND IN CYCLONIC FLOW THROUGH MONDAY MORNING...WHICH
WILL HELP KEEP TEMPERATURES UP TONIGHT. OTHERWISE...QUIET WEATHER
WITH SEASONABLE TEMPERATURES IN STORE ON MONDAY AND TUESDAY...BEFORE
NEXT STORM SYSTEM DEVELOPS OVER THE PLAINS AND BRINGS ANOTHER ROUND
OF POTENTIALLY STRONG TO SEVERE STORMS TO THE REGION TUESDAY NIGHT.

CVKING

&&

.AVIATION...
FOR THE 18Z TAFS...TSRA CHANCES WILL BE GREATEST INVOF CDFNT NOW
MOVING THRU THE FA...WITH A WIND SHIFT TO WSW EXPECTED AFTER
FROPA. THEN LOOK FOR CIGS TO BEGIN FALLING AS LO LEVEL WINDS
EVENTUALLY GAIN A NLY COMPONENT AND ARE ABLE TO DRAW IN THE LOWER
CIGS ALREADY IN PLACE ACROSS IA. EXPECT MVFR CIGS BY LATE TONIGHT
FOR ALL LOCATIONS...WITH AREAS DIPPING INTO IFR RANGE FOR AREAS
ACROSS THE STL METRO AREA AND N AND E. A SLOW RECOVERY IN CIGS
THEN EXPECTED FOR MONDAY MORNING WITH MORE SIGNIFICANT IMPROVMENT
AROUND MIDDAY.

TES

&&

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

WFO LSX

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1157 AM CDT SUN APR 16 2006

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-171200-
ADAMS IL-AUDRAIN-BOND IL-BOONE-BROWN IL-CALHOUN IL-CALLAWAY-
CLINTON IL-COLE-CRAWFORD-FAYETTE IL-FRANKLIN-GASCONADE-GREENE IL-
IRON-JEFFERSON-JERSEY IL-KNOX-LEWIS-LINCOLN-MACOUPIN IL-MADISON-
MADISON IL-MARION-MARION IL-MONITEAU-MONROE-MONROE IL-MONTGOMERY-
MONTGOMERY IL-OSAGE-PIKE-PIKE IL-RALLS-RANDOLPH IL-REYNOLDS-
SHELBY-ST. CHARLES-ST. CLAIR IL-ST. FRANCOIS-ST. LOUIS-
ST. LOUIS CITY-STE. GENEVIEVE-WARREN-WASHINGTON-WASHINGTON IL-
1157 AM CDT SUN APR 16 2006

...MODERATE RISK FOR SEVERE THUNDERSTORMS THROUGH EARLY THIS EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN AND
CENTRAL MISSOURI AS WELL AS SOUTHWEST ILLINOIS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF A COLD
FRONT THAT WILL MOVE EAST ACROSS MISSOURI AND ILLINOIS THIS
AFTERNOON. SOME OF THESE STORMS MAY QUICKLY BECOME SEVERE WITH
LARGE HAIL UP TO THE SIZE OF BASEBALLS AND DAMAGING WINDS IN
EXCESS OF 60 MPH. IN ADDITION...CONDITIONS ACROSS EASTERN MISSOURI
AND CENTRAL ILLINOIS APPEAR FAVORABLE FOR A FEW TORNADOES. AS A
RESULT...THERE IS A MODERATE RISK FOR SEVERE THUNDERSTORMS EAST OF
THE MISSISSIPPI RIVER THROUGH EARLY THIS EVENING. A SLIGHT RISK FOR
SEVERE THUNDERSTORMS EXISTS ELSEWHERE FOR THIS AFTERNOON ONLY.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON TUESDAY AS ANOTHER
STORM SYSTEM AFFECTS THE AREA. THE THREAT OF THUNDERSTORMS WILL
CONTINUE INTO WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE NEEDED ACROSS EASTERN MISSOURI AND
ALL OF CENTRAL ILLINOIS THIS AFTERNOON AND EARLY THIS EVENING.
SPOTTERS ARE ASKED TO RELAY ALL SEVERE WEATHER REPORTS IMMEDIATELY
TO THE NATIONAL WEATHER SERVICE.

TES