Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS02 KWNS 031729
SWODY2
SPC AC 031728

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT MON AUG 03 2015

VALID 041200Z - 051200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC
STATES/DELMARVA...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC
STATES/NEW ENGLAND...

...THERE IS A MRGL RISK OF SVR TSTMS FROM THE HIGH PLAINS TO THE TN
VALLEY/LOWER OH VALLEY...

...SUMMARY...
STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE TUESDAY ACROSS
PORTIONS OF THE MID-ATLANTIC STATES/NEW ENGLAND AS WELL AS THE
PLAINS.

...SYNOPSIS...
A HIGHLY AMPLIFIED/BLOCKING-TYPE PATTERN WILL EXIST OVER THE
CONUS/CANADA TUESDAY. A SEMI-AMPLIFIED/MODERATELY STRONGER CORRIDOR
OF LOWER-AMPLITUDES WESTERLIES WILL REMAIN OVER THE NORTHERN HALF OF
THE CONUS ON THE SOUTHERN PERIPHERY OF TWO LARGE-SCALE TROUGHS...ONE
OVER BRITISH COLUMBIA WITH THE OTHER CENTERED OVER NORTHERN PORTIONS
OF ONTARIO/QUEBEC.

...NEW ENGLAND/MID-ATLANTIC STATES...
MODERATELY STRONG/SEASONALLY COOL CYCLONIC MID/UPPER-LEVEL FLOW WILL
PERSIST OVER THE GREAT LAKES AND THE NORTHEAST/MID-ATLANTIC STATES
AND NEW ENGLAND ON TUESDAY. IN THE LOW-LEVELS...A COLD FRONT WILL
CONTINUE AN EASTWARD-PROGRESSION TOWARD THE EASTERN SEABOARD...WITH
A MOIST/POTENTIALLY UNSTABLE AIR MASS PRECEDING THE FRONT IN AREAS
GENERALLY NEAR/EAST OF THE I-95 CORRIDOR. WHILE VERY STRONG SHEAR
/35-50 KT EFFECTIVE/ WILL TEND TO COINCIDE WITH MODERATE INSTABILITY
DURING THE AFTERNOON...THERE ARE STILL SOME UNCERTAINTIES RELATED TO
FRONTAL TIMING AND THE POSSIBILITY OF RELATIVELY MODEST NEAR-FRONTAL
CONVERGENCE...PARTICULARLY GIVEN WHAT APPEARS TO BE SUB-OPTIMAL
TIMING OF EMBEDDED/LOWER-AMPLITUDE SHORTWAVE FEATURES. WHERE STORMS
DO DEVELOP/INCREASE DURING THE AFTERNOON...AT LEAST SOME SEVERE RISK
SEEMS LIKELY...WITH DAMAGING WINDS THE MOST PROBABLE SEVERE HAZARD.
AREAS INCLUDING THE DELMARVA/NEARBY NJ IN VICINITY OF A WEAK SURFACE
WAVE APPEAR TO HAVE A SOMEWHAT GREATER RISK FOR SOME SEVERE
THUNDERSTORMS...WHILE OTHER PARTS OF SOUTHERN/EASTERN NEW ENGLAND
COULD ALSO ULTIMATELY WARRANT A SLIGHT RISK UPGRADE PENDING
SUFFICIENT DESTABILIZATION.

...HIGH PLAINS TO LOWER OH VALLEY/TN VALLEY...
EMBEDDED WITHIN A BELT OF MODERATELY STRONG WEST-NORTHWESTERLY FLOW
ALOFT...ONE SHORTWAVE TROUGH WILL LIKELY CONTINUE EASTWARD FROM WY
VICINITY EARLY TUESDAY TOWARD THE NORTH-CENTRAL PLAINS...WHILE ONE
OR MORE CONVECTIVELY RELATED DISTURBANCES MAY ALSO CROSS THE
SOUTH-CENTRAL PLAINS/OZARKS. WIDELY SCATTERED SHOWERS/THUNDERSTORMS
ARE LIKELY TO BE ONGOING TUESDAY MORNING ACROSS PARTS OF THE CENTRAL
PLAINS AND OTHER NEARBY AREAS OF THE MISSOURI VALLEY/LOWER OH
VALLEY. A FEW OF THESE STORMS MAY DIURNALLY INTENSIFY WITHIN A
MODERATELY UNSTABLE/MODEST SHEAR ENVIRONMENT NEAR A
NORTHWEST-SOUTHEAST-ORIENTED BOUNDARY FROM THE MIDDLE MO VALLEY TO
THE LOWER OH VALLEY/TN VALLEY.

FARTHER WEST...WHILE EARLY-DAY CLOUD COVER/PRECIPITATION MAY BE
FACTORS...OTHER POTENTIALLY SOMEWHAT MORE SUSTAINED/INTENSE
CONVECTION SHOULD DEVELOP/INCREASE TUESDAY AFTERNOON ACROSS THE
CENTRAL HIGH PLAINS INCLUDING WESTERN PARTS OF NEB/KS...WHERE AN
UPGRADE TO SLIGHT RISK MAY BE WARRANTED IN THE DAY 1 TIME FRAME
PENDING EARLY-DAY DETAILS/GREATER CONFIDENCE IN MODERATE
DESTABILIZATION. AT LEAST ISOLATED BOUTS OF DAMAGING WINDS/SOME HAIL
WILL BE POSSIBLE ACROSS THE REGION ESPECIALLY TUESDAY LATE
AFTERNOON/EVENING.

..GUYER.. 08/03/2015



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