The SPC is forecasting ...severe thunderstorms expected over parts of the lower mississippi valley tonight.... Please read the latest public statement about this event.
| Categorical Graphic |
|---|
|
| Probabilistic Tornado Graphic |
 |
 |
| Probabilistic Damaging Wind Graphic |
 |
 |
| Probabilistic Large Hail Graphic |
 |
 |
SPC AC 281620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1020 AM CST WED FEB 28 2007 VALID 281630Z - 011200Z ...THERE IS A MDT RISK OF SVR TSTMS TONIGHT OVER PARTS OF SOUTHERN AND CENTRAL MO... NRN AR AND SMALL PART OF NORTHEAST OK AND SOUTHEAST KS... ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTERNOON AND OVERNIGHT OVER PARTS OF THE CENTRAL PLAINS AND MID MS VALLEY...... ...SYNOPSIS... DEEPENING COLD UPPER TROUGH MOVING EWD ACROSS WRN U.S. AS ADVERTISED BY LAST SEVERAL MODEL RUNS WITH A POWERFUL 150KT POLAR JET MAX CURRENTLY ACROSS AZ/NM DRIVING ACROSS SRN PLAINS TONIGHT. RAPID DEEPENING OF SURFACE LOW TX/OK PANHANDLE BY LATER THIS AFTERNOON WITH LOW THEN TRACKING ENEWD INTO WRN MO AHEAD OF INTENSIFYING UPPER TROUGH BY 12Z THU. STRENGTHENING LOW LEVEL JET SRN PLAINS INTO MID MS VALLEY THRU THE PERIOD WILL RAPIDLY SPREAD GULF MOISTURE NEWD. BY LATER THIS AFTERNOON 60F DEWPOINTS SHOULD BE AS FAR N AS ERN OK/WRN AR WITH MID 50S TO SERN KS/SWRN MO. ELEVATED MIX LAYER HAS OVERSPREAD PLAINS WHICH WILL DELAY INITIATION OF SURFACE CONVECTION UNTIL LATE AFTERNOON OR EARLY EVENING WHEN LARGE SCALE ASCENT AND MID LEVEL COOLING ARRIVE WITH APPROACH OF TROUGH AND EXIT REGION OF JET MAX. ...KS/OK LATE THIS AFTERNOON AND EVENING... DRY LINE WILL SHARPEN UP ACROSS CENTRAL OK INTO SERN KS DURING AFTERNOON WITH MLCAPE INCREASING TO 1000-1500 J/KG ERN OK. BY LATE THIS AFTERNOON OR EARLY EVENING SEVERE THUNDERSTORMS SHOULD RAPIDLY DEVELOP AS CAP WEAKENS SUFFICIENTLY. INITIAL DEVELOPMENT MOST LIKELY VICINITY KS/OK BORDER WITH STORMS THEN RAPIDLY EXPANDING ACROSS ERN KS INTO SWRN MO. STORMS EXPECTED TO EVOLVE FAIRLY QUICKLY INTO SUPERCELLS GIVEN THE STRONG SHEAR BOTH SPEED AND DIRECTIONAL. IN ADDITION TO LARGE HAIL AND DAMAGING WINDS... TORNADOS WILL BE POSSIBLE. SWD EXTENSION OF DEVELOPMENT ALONG DRY LINE THRU ERN OK SHOULD OCCUR BUT IT COULD BE WELL AFTER DARK WHEN THE CAP WEAKENS SUFFICIENTLY. ...ERN OK/MO/AR OVERNIGHT... OVERNIGHT MID LEVEL CAP WILL ERODE MUCH OF THIS AREA E OF DRY LINE AND AHEAD OF DEEPENING SURFACE LOW AS LARGE SCALE ASCENT CONTINUES TO INCREASE AND SPREAD EWD. EVEN WITH SOME QUESTION AS TO AMOUNT OF INSTABILITY ...THE STRENGTH OF THE KINEMATICS AND VERY STRONG SHEAR PROFILES SUPPORT TORNADO POTENTIAL ALONG WITH LARGE HAIL AND DAMAGING WINDS. THE IMPRESSIVE STRENGTH OF THIS SYSTEM SUPPORTS POSSIBILITY OF STRONG TORNADOS OVERNIGHT. ...IL/KY/IN AFTER MIDNIGHT... STRONG LOW LEVEL JET WILL EXPAND RAPIDLY EWD ACROSS MID MS VALLEY OVERNIGHT WITH GULF MOISTURE SURGING NEWD. MODEL SOUNDINGS AFTER 06Z SHOW SUFFICIENT ELEVATED CAPE TO SUPPORT A RISK OF AT LEAST LARGE HAIL ACROSS MID MS RIVER REGION. RISK COULD REACH TO WESTERN IL/KY AND SWD TO WRN TN AND NRN MS BY 12Z ..HALES.. 02/28/2007 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z