Spoiler (Click to View)

Spoiler (Click to View)

Quote:...SYNOPSIS...
A LARGE AND POWERFUL UPPER LEVEL TROUGH NOW OVER THE GREAT BASIN
WILL CONTINUE EWD INTO THE PLAINS BY AFTERNOON...REACHING THE
MID/UPPER MS VALLEY REGION BY TUE MORNING. AT THE SURFACE...A LOW
PRESSURE TROUGH WILL DEEPEN FROM THE DAKOTAS SWD INTO KS BY
00Z...WITH RAPID PRESSURE FALLS FROM MO INTO WI OVERNIGHT.
MEANWHILE...PROLONGED SLY LOW LEVEL FLOW AND AN INTENSE LOW LEVEL
JET WILL BRING AT LEAST LOWER 60S BOUNDARY LAYER DEWPOINTS NWD AHEAD
OF THE DEVELOPING COLD FRONT. THE RESULT SHOULD BE SUFFICIENT
INSTABILITY FOR MAINLY SEVERE WIND AND PERHAPS ISOLATED TORNADOES.

ELSEWHERE...A LEAD SHORTWAVE TROUGH OVER THE GULF COAST STATES WILL
WEAKEN AS IT MOVES INTO THE CAROLINAS BY EVENING. COOL AIR ALOFT
ASSOCIATED WITH THIS FEATURE...AS WELL AS POCKETS OF DESTABILIZATION
AHEAD OF OUTFLOW BOUNDARIES PRODUCED BY MORNING CONVECTION WILL
YIELD AN ENVIRONMENT FAVORABLE FOR SCATTERED SEVERE STORMS.

...NERN MO...WRN IL...ERN IA...SWRN WI...
A WEAK UPPER TROUGH AXIS WILL EXIT THE AREA EARLY THIS
MORNING...WITH NO SEVERE ACTIVITY EXPECTED THROUGH 00Z. DURING THE
DAY...SLY FLOW WILL INCREASE IN ADVANCE OF THE DEVELOPING LOW...WITH
DESTABILIZATION OCCURRING DURING THE EVENING AND OVERNIGHT DUE TO A
STRONG LOW LEVEL JET. BY AROUND 03Z...AN INTENSIFYING COLD FRONT
WILL STRETCH FROM CNTRL IA INTO SERN KS. INITIAL DEVELOPMENT MAY
OCCUR BETWEEN 03-06Z...MOST LIKELY IN THE FORM OF A SQUALL LINE WITH
DAMAGING WINDS AND PERHAPS EMBEDDED AREAS OF ROTATION. ALTHOUGH NAM
AND GFS MODELS DIFFER WITH THE 12Z COLD FRONT/SQUALL LINE LOCATION
BY AS MUCH AS 150 NM...A SUBSTANTIAL PRESSURE RISE/FALL COUPLET IS
LIKELY TO ACCOMPANY THIS FRONT...WHICH WILL AID IN THE DEVELOPMENT
OF POTENTIALLY WIDESPREAD DAMAGING WINDS.

...SERN AL INTO SC...
SEVERAL CLUSTERS OF STORMS WERE ONGOING AS OF 06Z FROM NRN LA ACROSS
NRN MS/AL AND INTO MIDDLE TN. OTHER STORMS EXTENDED FROM THE N CNTRL
GULF OF MEXICO NWD INTO SRN AL ALONG A DEEPER CONFLUENCE AXIS NEAR
THE LEADING EDGE OF A TROPICAL AIR MASS RETURN. SUBSTANTIAL
UNCERTAINTY EXISTS IN REGARD TO LOCATIONS OF POTENTIAL OUTFLOW
BOUNDARIES LATER TODAY. HOWEVER...IT APPEARS LIKELY THAT THE AREA
FROM SRN AL INTO SRN GA...NRN FL...SC MAY HAVE THE BEST CHANCE AT
DESTABILIZATION WITH RELATIVELY UNDISTURBED AIR. GIVEN PRESENCE OF
STEEP LAPSE RATES ALOFT AND AMPLE DEEP LAYER SHEAR...LARGE HAIL AND
A FEW DAMAGING WIND GUSTS WILL BE POSSIBLE.