Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 201648
SWODY2
SPC AC 201648

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1148 AM CDT SAT SEP 20 2014

VALID 211200Z - 221200Z

...NO SVR TSTM AREAS FORECAST...

...SUMMARY...
SCATTERED SHOWERS AND ISOLATED STRONGER THUNDERSTORMS WILL BE
POSSIBLE ACROSS THE UPPER OHIO VALLEY AND CENTRAL APPALACHIANS INTO
EASTERN NEW YORK ON SUNDAY. SCATTERED THUNDERSTORMS ARE ALSO
EXPECTED ACROSS THE INTERIOR WEST...THE RIO GRANDE VALLEY...AND OVER
FLORIDA.

...SYNOPSIS...

THE UPPER TROUGH OVER THE GREAT LAKES REGION WILL CONTINUE TO DEEPEN
AND TRACK EAST TOWARD NEW ENGLAND AND THE APPALACHIANS BY 12Z
MONDAY. THE ATTENDANT SURFACE COLD FRONT WILL QUICKLY SHIFT EASTWARD
ACROSS THE OHIO VALLEY BY AFTERNOON...BECOMING POSITIONED ALONG THE
NEW ENGLAND COAST SOUTHWESTWARD INTO THE DEEP SOUTH. ISOLATED STRONG
TO MARGINALLY SEVERE THUNDERSTORMS WILL BE POSSIBLE ALONG THE COLD
FRONT FROM THE CENTRAL APPALACHIANS INTO EASTERN NY DURING THE
AFTERNOON.

FURTHER WEST...THE UPPER LOW OVER CA...EMBEDDED WITHIN LARGER-SCALE
RIDGE WILL MIGRATE NORTHEAST ACROSS THE GREAT BASIN THROUGH THE
FORECAST PERIOD. A FEW STRONG TO MARGINALLY SEVERE THUNDERSTORMS
WILL BE POSSIBLE ACROSS PARTS OF THE GREAT BASIN AS THIS OCCURS.

...PORTIONS OF THE OHIO VALLEY/CENTRAL APPALACHIANS INTO NY...

HEIGHT FALLS WILL OVERSPREAD THE REGION IN CONJUNCTION WITH STRONG
CYCLONIC MIDLEVEL FLOW /30-45 KT AT 700 MB/ AS THE DEEPENING TROUGH
SHIFTS EWD. AS SFC HEATING OCCURS...LOW LEVEL LAPSE RATES WILL
INCREASE AND MLCAPE VALUES WILL APPROACH 1500 J/KG. AMPLE FORCING
FOR ASCENT AS THE COLD FRONT MOVES THROUGH THE REGION AND DEEP LAYER
SHEAR GREATER THAN 40 KT WILL LEAD TO FAST MOVING...BROKEN BANDS OF
CONVECTION. STRONGER STORMS WILL BE CAPABLE OF GUSTY WINDS WITH
POSSIBLY SOME ISOLATED STRONG/SEVERE GUSTS. POOR MIDLEVEL LAPSE
RATES AND GENERALLY WEAK INSTABILITY SHOULD LIMIT LONGEVITY OF ANY
MORE VIGOROUS UPDRAFTS AND ANY HAIL SHOULD REMAIN BELOW SEVERE
LIMITS. INTENSITY OF STORMS WILL QUICKLY WANE WITH LOSS OF DAYTIME
HEATING.

...GREAT BASIN...

AS THE UPPER LOW TRACK NORTHEAST FROM CENTRAL CA AND ACROSS
NV...MODERATE DEEP LAYER SHEAR /30-35 KT/ AND FORCING FOR ASCENT
WILL OVERSPREAD MUCH OF ERN NV TO WRN CO. SHOWERS AND THUNDERSTORMS
WILL LIKELY BE ONGOING ACROSS PARTS OF THE AREA AT THE BEGINNING OF
THE PERIOD...WITH ADDITIONAL DEVELOPMENT EXPECTED LATER IN THE
AFTERNOON AS DAYTIME HEATING RESULTS IN WEAK /LESS THAN 750 J PER
KG/ DESTABILIZATION. SFC TEMPERATURES WILL REMAIN ON THE COOL SIDE
WITH DEWPOINTS IN THE 40S AND 50S...BUT SOME GUSTY WINDS WILL BE
POSSIBLE WITH ADEQUATELY STEEP LOW LEVEL LAPSE RATES EXPECTED.
COOLING TEMPERATURES ALOFT ALSO COULD AID IN SOME SMALL/MARGINALLY
SEVERE HAIL.

..LEITMAN.. 09/20/2014



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