Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 200532
SWODY2
SPC AC 200531

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1231 AM CDT WED AUG 20 2014

VALID 211200Z - 221200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
THUNDERSTORMS...SOME STRONG...WILL BE POSSIBLE ACROSS PARTS OF THE
GREAT LAKES AND OHIO VALLEY REGION AS WELL AS ACROSS PARTS OF THE
CENTRAL PLAINS. SOME HAIL AND GUSTY WINDS WILL BE POSSIBLE WITH THE
STRONGEST STORMS.

...SYNOPSIS...

THE UPPER RIDGE OVER THE SOUTHERN AND CENTRAL U.S. WILL CONTINUE TO
BUILD NORTHWARD AS THE SUBTROPICAL HIGH STRENGTHENS NEAR THE GULF
COAST REGION. ACROSS THE WEST...THE SHORTWAVE TROUGH OVER THE
INTERMOUNTAIN WEST REGION WILL STRENGTHEN BY THE END OF THE PERIOD
AS AN UPPER LOW DEVELOPS FROM SEWD ADVANCING SHORTWAVE IMPULSE INTO
THE PACIFIC NORTHWEST.

AT THE SURFACE...LOW PRESSURE NEAR THE MANITOBA/ND BORDER WILL
SLOWLY PROGRESS E/NE. AN ATTENDANT SWWD TRAILING COLD FRONT WILL
SURGE E/SE ACROSS MN AND INTO THE MID-MO VALLEY/CNTRL PLAINS BY
FRIDAY MORNING. ADDITIONALLY...A DRYLINE WILL INTERSECT THE COLD
FRONT NEAR THE WRN NEB/KS BORDER DURING THE AFTERNOON...AND EXTEND
S/SWWD ACROSS WRN KS INTO THE OK/TX PANHANDLE AND FAR ERN NM.
FINALLY...A WARM FRONT OVER THE MID-MS TO LOWER OH VALLEY WILL LIFT
NORTHWARD TOWARD THE GREAT LAKES.

...CNTRL PLAINS INTO IA/FAR NW MO...

THUNDERSTORMS MAY BE ONGOING ACROSS PORTIONS OF THE AREA THURSDAY
MORNING ASSOCIATED WITH A DECAYING MCS. ANY LINGERING CLOUD COVER
FROM THIS SYSTEM COULD LIMIT REDEVELOPMENT OF STORMS LATER IN THE
AFTERNOON/EVENING NEAR THE SEWD ADVANCING COLD FRONT ACROSS CNTRL
NEB...OR ALONG THE SFC DRYLINE ACROSS WRN KS. IF STORM DO DEVELOP IN
THESE AREAS...SOME STRONG TO LOCALLY SEVERE STORMS WILL BE POSSIBLE
GIVEN 0-6 KM SHEAR AROUND 30-40 KT...STEEP LAPSE RATES AND MLCAPE
VALUES AROUND 1500 J/KG. CONVECTION WOULD LIKELY REMAIN ISOLATED
GIVEN A LACK OF STRONGER FORCING FOR ASCENT OVER THE AREA.
HOWEVER...SOME MAINTENANCE AND/OR UPSCALE GROWTH COULD OCCUR AS
STORMS PROPAGATE EWD TOWARD THE MID-MO VALLEY AS A SWLY LLJ AROUND
30-40 KT DEVELOPS OVERNIGHT. THIS REMAINS MORE UNCERTAIN THOUGH.

...GREAT LAKES/OH VALLEY REGION...

WIDESPREAD CONVECTION IS LIKELY TO BE ONGOING THURSDAY IN WARM
ADVECTION REGIME AS THE SFC WARM FRONT RETREATS NORTHWARD THROUGH
THE AFTERNOON. DEEP LAYER SHEAR WILL BE ADEQUATE /25-35 KT/ FOR SOME
SEMI-ORGANIZED STRUCTURES AND ANY BREAKS IN PRECIPITATION AND CLOUD
COVER COULD RESULT IN STEEPENING LAPSE RATES AND WEAK TO MODERATE
INSTABILITY. ADDITIONALLY...PW VALUES AROUND 1.5 TO 2 INCHES...COULD
ALLOW FOR FEW STRONG WIND GUSTS/WET DOWNBURSTS. HOWEVER...WIDESPREAD
ORGANIZED SEVERE THREAT APPEARS LIMITED AT THIS TIME.

..LEITMAN.. 08/20/2014



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