Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS02 KWNS 220550
SWODY2
SPC AC 220549

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1249 AM CDT TUE JUL 22 2014

VALID 231200Z - 241200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF WRN/CNTRL MT...

...THERE IS A SLGT RISK OF SVR TSTMS FOR PARTS OF NEW ENGLAND...

...SUMMARY...
SEVERE STORMS ARE POSSIBLE ACROSS PARTS OF NEW ENGLAND AND MONTANA
WEDNESDAY LATE AFTERNOON AND EVENING. ELSEWHERE...STRONG TO LOCALLY
SEVERE STORMS ARE POSSIBLE OVER THE NORTHERN HIGH PLAINS AND FROM
THE NORTHEAST TO THE OZARKS AREA.

...SYNOPSIS...
A VIGOROUS SHORTWAVE TROUGH SHOULD PUSH INLAND OVER THE PACIFIC NW.
A MID-LEVEL ANTICYCLONE WILL SLOWLY WEAKEN BUT REMAIN ANCHORED OVER
THE SRN ROCKIES WITH A RIDGE EMANATING N ACROSS THE NRN HIGH PLAINS.
A BROAD MID-LEVEL TROUGH WILL PROGRESS E OVER SE CANADA/NE CONUS. A
WEAK MID-LEVEL LOW SHOULD DRIFT W ALONG THE LA COAST. AT THE
SURFACE...A COLD FRONT SHOULD STRETCH FROM NEW ENGLAND TO THE OZARKS
BY WED EVENING WITH A LEE TROUGH ANCHORED OVER THE NRN/CNTRL HIGH
PLAINS. A COLD FRONT SHOULD PUSH E ACROSS THE NRN ROCKIES WED NIGHT.

...WRN/CNTRL MT...
STRENGTHENING MID/UPPER-LEVEL SWLYS AND HEIGHT FALLS WILL OVERSPREAD
THE NRN ROCKIES AHEAD OF THE APPROACHING VIGOROUS SHORTWAVE TROUGH.
LOW-LEVEL E/SELYS SHOULD AID IN ADVECTING THE NRN HIGH PLAINS
MOISTURE PLUME ALONG THE LEE OF THE HIGHER TERRAIN. 50S SURFACE DEW
POINTS IN CONJUNCTION WITH STEEP TROPOSPHERIC LAPSE RATES SHOULD
SUPPORT WEAK TO MODERATE BUOYANCY BY PEAK HEATING. AT LEAST ISOLATED
STORMS SHOULD FORM OVER THE HIGHER TERRAIN OF WRN MT. ELONGATED
HODOGRAPHS WILL BE FAVORABLE FOR SPLITTING SUPERCELLS CAPABLE OF
ISOLATED SEVERE WIND/HAIL.

...NEW ENGLAND...
A BELT OF 30-40 KT 700 MB SWLYS SHOULD OVERSPREAD THE WARM SECTOR
AHEAD OF THE SURFACE COLD FRONT. ALTHOUGH MID-LEVEL LAPSE RATES WILL
BE MODEST...MIDDLE TO UPPER 60S SURFACE DEW POINTS AND FAVORABLE
TIMING OF THE FRONT WITH RESPECT TO PEAK HEATING SHOULD RESULT IN
MLCAPE REACHING 1000-1500 J/KG. MID-LEVEL HEIGHT FALLS AND FRONTAL
CONVERGENCE SHOULD FOSTER SCATTERED TO NUMEROUS STORMS INTO THE
EVENING. ISOLATED DAMAGING WINDS WILL BE THE PRIMARY HAZARD.

...NRN HIGH PLAINS...
SUPERCELL WIND PROFILES WILL EXIST ALONG THE LEE TROUGH WED LATE
AFTERNOON AND EVENING. BUT THE REGION WILL REMAIN UNDER THE
INFLUENCE OF A MID-LEVEL RIDGE. THIS RENDERS LOW CONFIDENCE IN
THE AMOUNT/SUSTAINABILITY OF DIURNALLY-DRIVEN TSTMS. SHOULD GREATER
COVERAGE OF TSTMS BE ANTICIPATED IN LATER OUTLOOKS...AN UPGRADE TO
SLIGHT RISK WOULD BE WARRANTED. HIGHER CONFIDENCE EXISTS IN
NOCTURNAL WAA-DRIVEN TSTMS ARCING TOWARDS THE CNTRL DAKOTAS...WITH A
THREAT FOR LOCALLY SEVERE HAIL.

...OZARKS AREA...
GUIDANCE IS CONSISTENT IN DEPICTING A BELT OF ENHANCED MID-LEVEL
N/NELYS BETWEEN THE SRN ROCKIES HIGH AND LA COASTAL LOW. ISOLATED TO
SCATTERED CONVECTION MAY FORM ALONG THE COLD FRONT IN S MO. THIS
ACTIVITY MAY COALESCE INTO MULTICELL CLUSTERS THAT PROPAGATE SW
ACROSS A VERY WARM AND AT LEAST MODERATELY UNSTABLE AIR MASS...WITH
A RISK FOR DAMAGING WINDS.

...OH VALLEY...CNTRL APPALACHIANS...
SCATTERED TO NUMEROUS STORMS ARE ANTICIPATED WED AFTERNOON/EVENING
ALONG THE COLD FRONT WITHIN A MODERATELY BUOYANT AIR MASS
CHARACTERIZED BY UPPER 60S TO LOWER 70S SURFACE DEW POINTS.
DEEP-LAYER SHEAR WILL BE WEAKER RELATIVE TO FARTHER NE/SW. BUT GIVEN
THE AMOUNT OF STORMS...LOOSELY-ORGANIZED MULTICELL CLUSTERS MAY FORM
WITH LOCALIZED DAMAGING WINDS.

..GRAMS.. 07/22/2014



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