Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
SPC AC 220556
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1156 PM CST MON DEC 21 2015
VALID 221200Z - 231200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN TX INTO WRN AR...
...THERE IS A MRGL RISK OF SVR TSTMS FROM THE ARKLATEX REGION INTO
THE CNTRL GULF COAST...
...SUMMARY...
SEVERE THUNDERSTORMS ARE POSSIBLE TUESDAY NIGHT FROM PORTIONS OF
NORTHEASTERN TEXAS INTO WESTERN ARKANSAS...WITH MORE ISOLATED
ACTIVITY ACROSS LOUISIANA AND THE CENTRAL GULF COAST.
...SYNOPSIS...
AN EXPANSIVE AREA OF CYCLONIC FLOW ALOFT WILL AFFECT MUCH OF THE
CNTRL AND ERN STATES WITH PRIMARY LARGE-SCALE TROUGH AXIS DEVELOPING
INTO THE SRN PLAINS BY WED MORNING. LOW PRESSURE WILL DEEPEN OVER KS
AND OK THROUGH THE PERIOD WITH MOIST SLY RETURN FLOW ACROSS A BROAD
REGION FROM TX INTO THE SERN STATES. SHEAR PROFILES WILL BECOME
INCREASINGLY FAVORABLE FOR SEVERE STORMS OVER A LARGE
AREA...CONDITIONAL ON STORM FORMATION. THE MOST LIKELY AREAS FOR
STORMS WILL BE FROM NERN TX INTO WRN AR IN ASSOCIATION WITH A STRONG
LOW-LEVEL JET AND HEIGHT FALLS ALOFT...AND ACROSS THE CNTRL GULF
COAST REGION LATE IN THE PERIOD.
...NERN TX INTO WRN AR...
MOST THE OF DAY WILL BE VOID OF THUNDERSTORMS DUE TO TEMPORARY
SHORTWAVE-RIDGING AS A LEADING SRN-STREAM TROUGH EJECTS NEWD ACROSS
THE CNTRL GULF COAST STATES. OVERNIGHT...STRONG HEIGHT FALLS/COOLING
ALOFT WILL OCCUR WITH INCREASING FORCING FOR ASCENT ACROSS NRN TX
INTO OK. AT THE SAME TIME...MID 60S F DEWPOINTS WILL RACE NWD TOWARD
THE RED RIVER AND ARKLATEX OVERNIGHT. THOUGH CAPPING WILL INITIALLY
EXIST...GRADUAL LIFT AND MOISTENING FROM BELOW SHOULD RESULT IN A
RASH OF STORMS...PERHAPS ELEVATED. HAIL WOULD APPEAR TO BE THE MAIN
RISK WITH LONG HODOGRAPHS AND COOL TEMPERATURES ALOFT...FAVORABLE
FOR SUPERCELLS. THE TORNADO RISK WILL BE TEMPERED BY THE UNFAVORABLE
TIME OF DAY AND A RATHER BROAD FOCUS FOR LIFT.
...LA INTO THE CNTRL GULF COAST...
EARLY RAIN/STORMS SHOULD CLEAR DURING THE DAY IN THE WAKE OF A
LEADING SRN-STREAM DISTURBANCE. OVERNIGHT...THE MORE SUBSTANTIAL
SHORTWAVE TROUGH WILL DEVELOP TOWARD THE SABINE RIVER VALLEY...WITH
A MARKED INCREASE IN INSTABILITY FORECAST. IN ADDITION...HODOGRAPHS
WILL BECOME LARGER AND MORE SUPPORTIVE OF A TORNADO RISK. AT THIS
TIME...IT APPEARS ONLY ISOLATED CELLS WILL OCCUR BEFORE THE END OF
THE PERIOD...AND SOME UNCERTAINTY EXISTS REGARDING ONGOING NOCTURNAL
CONVECTION. IF SUBSEQUENT GUIDANCE BECOMES CLEARER AS FAR AS STORM
COVERAGE AND TIMING...A SLIGHT RISK FOR ISOLATED TORNADOES COULD BE
REQUIRED FOR PORTIONS OF SRN LA FOR LATE TUE NIGHT INTO WED MORNING.
CLUSTERS OF STORMS ARE LIKELY TO BE ONGOING ACROSS SRN MS/AL INTO
THE FL PANHANDLE EARLY TUE...BUT SHEAR WILL NOT BE PARTICULARLY
SUPPORTIVE OF SEVERE STORMS. BY WED MORNING...SOMEWHAT BETTER
INSTABILITY MAY APPROACH THE SHORE...WITH 40 KT SWLY 850 MB FLOW
CONDITIONALLY SUPPORTING A MARGINAL WIND/WEAK TOR RISK...ALTHOUGH TO
A LESSER EXTENT COMPARED TO THE LA AREA.
..JEWELL/PICCA.. 12/22/2015
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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