Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 060547
SWODY2
SPC AC 060546

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1246 AM CDT WED MAY 06 2015

VALID 071200Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF
SOUTHWEST/SOUTH-CENTRAL KS SWD TO NORTHWEST TX AND S PLAINS...

...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE SLIGHT RISK
AREA FROM PORTIONS OF THE MIDWEST SWD INTO THE CENTRAL/SRN PLAINS...

...SUMMARY...
SEVERE THUNDERSTORMS WILL BE POSSIBLE THURSDAY FROM PORTIONS OF THE
MIDWEST SOUTHWESTWARD INTO THE SOUTHERN AND CENTRAL PLAINS. THE
GREATEST POTENTIAL WILL EXIST FROM SOUTHWEST KANSAS SOUTHWARD INTO
NORTHWEST TEXAS.

...SYNOPSIS...
AN UPPER LEVEL LOW OVER NRN CA AT 12Z THURSDAY WILL MOVE SLOWLY SWD
DURING THE DAY. WITHIN THE SWLY MID-LEVEL FLOW DOWNSTREAM FROM THIS
FEATURE...A SHORTWAVE TROUGH OVER THE NRN PLAINS WILL WEAKEN AS IT
MOVES ACROSS THE UPPER MIDWEST AND INTO AN AREA OF UPPER LEVEL
RIDGING. A COLD FRONT WILL MOVE E ACROSS THE NRN PLAINS AND EXTEND
FROM ERN MN SWWD TO A SFC LOW VCTY SWRN KS BY 00Z FRI. A DRYLINE
WILL EXTEND SWD FROM THE SFC LOW INTO W TX.

AN AREA OF SFC LOW PRESSURE DEVELOPING OFF THE SOUTHEAST U.S. COAST
WILL MOVE NWD THURSDAY. CONSULT THE SPECIAL TROPICAL WEATHER OUTLOOK
ISSUED BY THE NATIONAL HURRICANE CENTER FOR THE LATEST INFORMATION.

TSTMS WILL LIKELY BE ONGOING AT 12Z THURSDAY IN AT LEAST TWO
AREAS...FIRST ACROSS ERN NEB/WRN IA IN ASSOCIATION WITH THE
NEWD-MOVING SHORTWAVE TROUGH...AND A SECOND AREA ACROSS SRN OK/RED
RIVER AREA SUPPORTED BY LOW-LEVEL WAA.

...CENTRAL/SRN PLAINS...
IN THE WAKE OF MORNING TSTMS...HEATING/DESTABILIZATION IS LIKELY TO
OCCUR IN ADVANCE OF THE COLD FRONT AND DRYLINE...RESULTING IN
MODERATE-STRONG SFC-BASED BUOYANCY BY LATE AFTN. LITTLE IN THE WAY
OF LARGE-SCALE FORCING FOR ASCENT IS EVIDENT THURSDAY...AND THE
TIMING OF SUBTLE SPEED MAXIMA WITHIN THE BROAD SWLY UPPER LEVEL FLOW
WILL LIKELY PLAY A ROLE IN EVENTUAL TSTM DEVELOPMENT. FURTHER...A
BRIEF PERIOD OF SHORTWAVE RIDGING IN THE WAKE OF THE NRN PLAINS
IMPULSE MAY DELAY INITIATION ACROSS THE CENTRAL PLAINS UNTIL LATE IN
THE DAY.

BY LATE AFTN/EARLY EVENING...TSTMS ARE LIKELY TO DEVELOP NEAR THE
TRIPLE POINT ACROSS SWRN KS...AND ALSO ALONG THE TX PANHANDLE/S
PLAINS PORTION OF THE DRYLINE. STRENGTHENING WIND FIELDS WILL RESULT
IN DEEP-LAYER SHEAR SUPPORTIVE OF SUPERCELLS...AND A PLUME OF
STEEPER MID-LEVEL LAPSE RATES WILL BECOME REESTABLISHED AND ADVECT
EWD ACROSS THE AREA. LARGE HAIL AND SOME TORNADO RISK WILL EXIST
WITH INITIALLY DISCRETE CELLS...WITH TSTMS COALESCING INTO AN MCS
DURING THE OVERNIGHT HOURS AS A NOCTURNALLY-STRENGTHENING LOW-LEVEL
JET/WAA DEVELOPS. INTRODUCTION OF A SIG HAIL AREA MAY BE NEEDED IN
LATER OUTLOOKS AS SPATIAL UNCERTAINTY DIMINISHES.

...IA/NWRN MO...
DESPITE WIDESPREAD CLOUDS/PRECIP...THE PRESENCE OF LOWER-MID 60S DEW
POINTS AND SOME DIURNAL HEATING SHOULD RESULT IN MODERATE SFC-BASED
BUOYANCY AHEAD OF THE COLD FRONT. DEEP-LAYER SHEAR WILL BE
SUBSTANTIALLY WEAKER THAN FARTHER SOUTH...BUT SUFFICIENT FOR
MULTICELL TSTMS WITH A RISK FOR ISOLATED SEVERE HAIL/WIND DURING THE
AFTN/EVENING.

...SRN NORTH CAROLINA COAST AFT 06Z...
00Z GUIDANCE DEPICTS STRENGTHENING LOW-LEVEL WIND FIELDS ASSOCIATED
WITH THE DEVELOPING SFC LOW OFF THE SERN U.S. LATE IN THE PERIOD.
RESULTING HODOGRAPHS SHOW SUBSTANTIAL LOW-LEVEL CURVATURE AND WOULD
SUPPORT SOME TORNADO RISK WITH ANY STRONGER CELLS APPROACHING THE
COAST. GIVEN TIMING UNCERTAINTIES WILL NOT INTRODUCE SVR PROBS WITH
THIS OUTLOOK.

..BUNTING.. 05/06/2015



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