Wednesday, May 19, 2010

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 191231
SWODY1
SPC AC 191230

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0730 AM CDT WED MAY 19 2010

VALID 191300Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER A LARGE PART OF OKLAHOMA
AND PARTS OF NORTH TEXAS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM SOUTHWEST KANSAS TO
NORTHERN TEXAS...PARTS OF ARKANSAS AND NORTHERN LOUISIANA......

...A SIGNIFICANT SEVERE THUNDERSTORM OUTBREAK IS STILL EXPECTED THIS
AFTERNOON AND INTO TONIGHT FOR A LARGE PART OF OKLAHOMA AND ADJACENT
PORTIONS OF NORTH TEXAS...


...SYNOPSIS...
THE UPPER LOW OVER NERN CO THIS MORNING AND ITS ASSOCIATED CYCLONIC
BAND OF STRONG MID AND UPPER WINDS WILL MOVE EWD INTO THE CENTRAL
AND SRN PLAINS TODAY. STRONG SLY LOW LEVEL JET OVERNIGHT SRN PLAINS
CONTINUED TO FEED A MOIST AND VERY UNSTABLE AIR MASS NWD IN ADVANCE
OF THE SURFACE LOW NOW VICINITY OK PANHANDLE.

...SRN PLAINS...
OVERNIGHT THUNDERSTORM ACTIVITY HAS EVOLVED INTO AN MCS THIS MORNING
MOVING EWD ACROSS NRN OK. EXPECT THESE STORMS TO GRADUALLY WEAKEN
AS THEY MOVE AWAY FROM THE LOW LEVEL JET AND BECOME INCREASINGLY
ELEVATED. OUTFLOW BOUNDARY FROM THIS ACTIVITY ALONG WITH THE
DEVELOPING DRY LINE WRN OK INTO NWRN TX WILL LIKELY BECOME FOCUS FOR
RAPID DEVELOPMENT OF SEVERE THUNDERSTORMS BY MID/LATE AFTERNOON.

WARM SECTOR DEWPOINTS OK RISING THRU THE 60S COUPLED WITH SURFACE
HEATING WILL LEAD TO A STRONGLY UNSTABLE AIR MASS BY MID AFTERNOON
WITH MLCAPES AOA 3000 J/KG TO THE S AND E OF BOUNDARIES.

WHILE THE LOW LEVEL JET SHOWS SOME WEAKENING AND VEERING DURING THE
DAY...DEEP LAYER SHEAR OF 40-50KT IS MORE THAN SUFFICIENT TO SUPPORT
DEVELOPMENT OF INTENSE SUPERCELLS ALONG WITH POTENTIAL FOR VERY
LARGE HAIL AND TORNADOES BY MID/LATE AFTERNOON.

INITIATION WOULD BE MOST LIKELY IN THE BETTER CONVERGENCE ALONG THE
COMBINATION E/W OUTFLOW BOUNDARY...WARM FRONT ACROSS NRN OK AND THEN
SWD THRU WRN OK INTO NWRN TX VICINITY DRY LINE.

DISCRETE SUPERCELLS DURING THE EARLY STAGES OF THE OUTBREAK WILL BE
ASSOCIATED WITH VERY LARGE HAIL AND THE POTENTIAL FOR STRONG
TORNADOES. FURTHER S INTO NWRN TX THE CAP WILL BE MORE OF AN ISSUE
BUT WITH SUCH AN UNSTABLE AIR MASS AND FAVORABLE SHEAR
PROFILES...STORMS THAT DO DEVELOP WILL BE NO LESS OF A SEVERE THREAT
AS THOSE IN OK.

STORMS WILL EVOLVE UPSCALE BY EVENING INTO ONE OR MORE MCS/S WITH
INCREASING THREAT OF DAMAGING WINDS AS THEY MOVE/PROPAGATE EWD
TOWARD WRN AR.

..HALES/JEWELL.. 05/19/2010

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