Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS01 KWNS 291251
SWODY1
SPC AC 291250

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0750 AM CDT FRI MAY 29 2015

VALID 291300Z - 301200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SRN PLNS...

...THERE IS A MRGL RISK OF SVR TSTMS FROM TX NORTHEAST TO THE UPR
AND MIDDLE GRT LKS...

...SUMMARY...
STRONG TO SEVERE STORMS WILL OCCUR LATER TODAY INTO TONIGHT OVER
WESTERN PORTIONS OF THE SOUTHERN PLAINS...WITH LARGE HAIL AND
LOCALLY DAMAGING WIND THE MAIN THREATS. SCATTERED THUNDERSTORMS WITH
STRONG WINDS AND PERHAPS HAIL ARE EXPECTED AHEAD OF A COLD FRONT
FROM THE GREAT LAKES SOUTHWEST ACROSS THE MID-MISSOURI VALLEY INTO
THE CENTRAL PLAINS.

...SYNOPSIS...
AHEAD OF AN AMPLIFYING TROUGH IN THE MAIN BELT OF THE WLYS OVER S
CNTRL CANADA...SHORTWAVE TROUGH NOW IN WY IS EXPECTED TO CONTINUE
ESE INTO SW NEB/NW KS THIS EVE...BEFORE RE-CURVING ENE INTO WRN IA
EARLY SAT. AHEAD OF THE LATTER DISTURBANCE...ELONGATED MCV/TROUGH
ASSOCIATED OVERNIGHT SQLN IN TX/OK SHOULD SHEAR NE INTO THE MO
OZARKS LATER TODAY...AND CONTINUE NE INTO THE MID MS/LWR OH VLYS
EARLY SAT.

COLD FRONT ATTENDANT TO THE WY IMPULSE...NOW CROSSING NEB...WILL BE
REINFORCED BY FRONT NOW OVER SD THAT IS ASSOCIATED WITH THE CANADIAN
TROUGH.  THE COMBINED BOUNDARIES SHOULD MOVE STEADILY SE THROUGH THE
PERIOD...PRECEDED BY A TROUGH/WIND SHIFT OVER THE SRN HIGH PLNS.

...SRN PLNS LATER TODAY/TNGT...
SUBSTANTIAL HEATING SHOULD OCCUR ALONG WIND SHIFT/LEE TROUGH OVER
THE SRN HIGH PLNS LATER TODAY...IN WAKE OF DEPARTING E TX SQLN.
COUPLED WITH RESIDUAL MOISTURE /DEWPOINTS IN THE UPR 50S TO AROUND
60 F/...RELATIVELY STEEP MID-LVL LAPSE RATES...AND UPSLOPE COMPONENT
TO LOW-LVL FLOW...SETUP SHOULD YIELD SCATTERED AFTN TSTMS
OVER THE HIGHER TERRAIN OF ERN NM AND NEAR WIND SHIFT OVER THE
ADJACENT PLNS EWD INTO W TX AND WRN OK AS MLCAPE INCREASES TO AROUND
1500-2000 J/KG.

ALTHOUGH SOME OF THE STORMS INITIALLY WILL BE HIGH-BASED...THEY
SHOULD INTENSIFY AS THEY MOVE/DEVELOP E/SE INTO THE EVE. 25-30 KT W
TO WNWLY 500 MB FLOW SHOULD PROVIDE SUFFICIENT DEEP SHEAR FOR A FEW
SUSTAINED MULTICELLS/MARGINAL SUPERCELLS WITH SOME RISK FOR SVR
HAIL...LOCALLY DMG WIND...AND PERHAPS A TORNADO OR TWO. SOME OF THE
STORMS LIKELY WILL MERGE INTO CLUSTERS THAT PERSIST INTO THE NIGHT
AS INCREASINGLY MOIST SLY LLJ NOCTURNALLY STRENGTHENS.

...GRT LKS SW INTO THE CNTRL PLNS THIS AFTN/EVE...
MODEST DESTABILIZATION WILL OCCUR AHEAD OF SE-MOVING COLD FRONT
TODAY...WITH MLCAPE INCREASING TO AROUND 1500 J/KG AMIDST 25-30 KT
SWLY DEEP SHEAR. SCTD AFTN MULTICELLS...INCLUDING A FEW CAPABLE OF
LOCALLY STRONG WINDS AND PERHAPS MARGINALLY SVR HAIL...MAY LINGER
THROUGH SUNSET.

...FAR E TX NNE INTO OZARKS/LWR MS VLY THIS AFTN/EVE...
A BAND OR TWO OF STORMS MAY REDEVELOP AHEAD OF MCV AND TRAILING
TROUGH/DEEP WIND SHIFT OVER PARTS OF THE S CNTRL STATES
TODAY...WHERE COMBINATION OF WEAKLY-SHEARED/DEEP UNIDIRECTIONAL SSW
FLOW WITH PW AOA 1.75 INCHES MAY YIELD AFTN/EVE MULTICELLS CAPABLE
OF ISOLD STRONG WIND GUSTS.

..CORFIDI/PICCA.. 05/29/2015




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