SPC AC 041617
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1117 AM CDT SUN APR 04 2010
VALID 041630Z - 051200Z
...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM
PARTS OF KS/OK THROUGH MUCH OF THE MS VALLEY...
...MO/IL...
MORNING WATER VAPOR LOOPS SHOW A SUBTLE SHORTWAVE TROUGH TRACKING
ACROSS PARTS OF WY/CO/KS. THIS FEATURE IS FORECAST TO MOVE RAPIDLY
EASTWARD INTO IA/MO BY THIS EVENING...THEN INTO THE SOUTHERN GREAT
LAKES REGION OVERNIGHT. MEANWHILE...SOUTHERLY LOW LEVEL WINDS ARE
QUICKLY TRANSPORTING GULF MOISTURE NORTHWARD ACROSS THE PLAINS AND
MS VALLEY. THIS WILL LEAD TO 50S/60S DEWPOINTS THROUGH MOST OF
MO/IL BY THIS EVENING...AND MODERATE CAPE VALUES /1000-2000 J/KG/
OVER THE REGION.
PRESENT INDICATIONS ARE THAT CLUSTER OF SHOWERS AND THUNDERSTORMS
OVER NORTHEAST MO WILL DEVELOP SLOWLY NORTHEASTWARD INTO IL THIS
AFTERNOON...AND MAY INTENSIFY AFTER 21Z AS GREATER LOW LEVEL
MOISTURE ARRIVES IN AREA. OTHER AND MORE INTENSE STORMS ARE LIKELY
TO FORM ALONG THE FRONT FROM NORTHERN IL/SOUTHEAST IA INTO NORTHERN
MO AROUND THE SAME TIME AS SHORTWAVE TROUGH APPROACHES FROM THE
WEST. FORECAST SOUNDINGS SHOW THERMODYNAMIC AND VERTICAL SHEAR
PROFILES FAVORABLE FOR ORGANIZED SEVERE STORMS AND POSSIBLE
SUPERCELLS. LARGE HAIL WILL BE THE MAIN INITIAL THREAT...WITH A
GREATER RISK OF DAMAGING WINDS DEVELOPING THROUGH THE EVENING AS THE
LINE OF STORMS MOVES ACROSS IL AND INTO WESTERN IND. ISOLATED
TORNADOES WILL ALSO BE POSSIBLE IN EMBEDDED SUPERCELLS ALONG THE
LINE...AND ESPECIALLY IF ANY CELLS CAN BECOME SUSTAINED AHEAD OF THE
SQUALL LINE.
...KS/OK...
THUNDERSTORMS ARE EXPECTED TO DEVELOP SOUTHWESTWARD ALONG THE FRONT
THIS EVENING INTO PARTS OF SOUTHEAST KS AND NORTHERN OK. THE
SHORTWAVE TROUGH WILL HAVE PASSED THIS REGION...WITH ONLY WEAK LARGE
SCALE FORCING OCCURRING AFTER DARK. THIS LEADS TO CONSIDERABLE
UNCERTAINTY REGARDING HOW FAR SOUTHWEST SEVERE STORMS CAN
DEVELOP...WITH SOME 12Z GUIDANCE SHOWING INITIATION AS FAR SOUTHWEST
AS WESTERN NORTH TX.
...AR...
FOR SEVERAL DAYS...MODELS HAVE BEEN CONSISTENT IN DEVELOPING
SCATTERED THUNDERSTORMS ACROSS AR TODAY...ALTHOUGH FORCING
MECHANISMS FOR ACTIVITY ARE HARD TO FIND. MOISTURE IS RAPIDLY
INCREASING OVER THIS REGION WITH AFTERNOON MLCAPE VALUES LIKELY TO
EXCEED 1500 J/KG OVER CENTRAL/EASTERN AR WHERE STRONGEST HEATING IS
EXPECTED. IT CURRENTLY APPEARS MOST LIKELY THAT STORM INITIATION
WILL OCCUR LATER THIS AFTERNOON OR EARLY EVENING. VERTICAL SHEAR
PROFILES ARE QUITE FAVORABLE SUGGESTING A CONDITIONAL RISK OF
DISCRETE SUPERCELLS CAPABLE OF LARGE HAIL AND TORNADOES.
..HART/HURLBUT.. 04/04/2010
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z
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