RSS Mesoscale Discussions from Storm Prediction Center
WW 548 SEVERE TSTM DC DE MD NJ VA CW 291555Z - 292300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 548
NWS STORM PREDICTION CENTER NORMAN OK
1155 AM EDT THU JUL 29 2010
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
DISTRICT OF COLUMBIA
DELAWARE
SOUTHERN AND EASTERN MARYLAND
SOUTHERN NEW JERSEY
MUCH OF CENTRAL AND EASTERN VIRGINIA
COASTAL WATERS
EFFECTIVE THIS THURSDAY MORNING AND EVENING FROM 1155 AM UNTIL
700 PM EDT.
HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES SOUTH
SOUTHWEST OF STAUNTON VIRGINIA TO 50 MILES SOUTH SOUTHEAST OF
ATLANTIC CITY NEW JERSEY. FOR A COMPLETE DEPICTION OF THE WATCH
SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
DISCUSSION...WITH THE AIR MASS TO THE S OF COLD FRONT NOW NEAR MD/PA
BORDER BECOMING MDTLY UNSTABLE AND UNCAPPED...THUNDERSTORMS WILL
INCREASE IN NUMBER AND INTENSITY VICINITY OF THE FRONT. WITH 30KT
OF SHEAR...COLD POOL DEVELOPMENT IS LIKELY AS STORMS FORM CLUSTERS
AND LINE SEGMENTS...RESULTING IN A WIND DAMAGE THREAT. STORMS WILL
DEVELOP SEWD ACROSS THE WATCH THRU THE AFTERNOON.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION
VECTOR 29025.
...HALES
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WW 0548 Status Reports
STATUS REPORT ON WW 548
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..PETERS..07/29/10
ATTN...WFO...LWX...PHI...AKQ...RNK...
STATUS REPORT FOR WS 548
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
DEC001-003-005-291840-
DE
. DELAWARE COUNTIES INCLUDED ARE
KENT NEW CASTLE SUSSEX
DCC001-291840-
DC
. DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE
DISTRICT OF COLUMBIA
MDC003-005-009-011-015-017-019-025-027-029-031-033-035-037-039-
041-045-047-510-291840-
MD
. MARYLAND COUNTIES INCLUDED ARE
ANNE ARUNDEL BALTIMORE CALVERT
CAROLINE CECIL CHARLES
DORCHESTER HARFORD HOWARD
KENT MONTGOMERY PRINCE GEORGES
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No Mesoscale Discussions are in effect as of Thu Jul 29 17:30:02 UTC 2010.
SPC 1730Z Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1209 PM CDT THU JUL 29 2010
VALID 301200Z - 311200Z
...THERE IS A SLGT RISK OF SVR TSTMS OVER A SMALL PORTION OF THE
CENTRAL PLAINS...
...CNTRL PLAINS...
ELEVATED THUNDERSTORM COMPLEX WILL BE ONGOING EARLY FRIDAY MORNING
OVER NERN NEB...NRN IA AND SWRN MN. ATTENDANT MID-LEVEL SHORTWAVE
TROUGH WILL CONTINUE ESE INTO THE MIDWEST DURING FRIDAY AFTERNOON
WITH FORWARD-FLANK OF THE COMPLEX DIMINISHING OVER THE UPPER MS
VALLEY REGION. HOWEVER...AIR MASS ALONG WRN FLANKS OF MORNING
STORMS WILL STRONGLY HEAT AMIDST RICH BOUNDARY LAYER MOISTURE /70S
SFC DEW POINTS/. GIVEN MLCAPES IN EXCESS OF 3500 J/KG AND MODESTLY
STEEP MID-LEVEL LAPSE RATES WILL GIVE RISE TO STRONG AFTERNOON
STORMS OVER SRN NEB...NERN KS...SWRN IA AND NWRN MO. DESPITE
MARGINAL SEVERE WIND PROFILES...ROBUST MULTICELL STORMS WILL BE
CAPABLE OF DAMAGING WIND GUSTS. PRESENCE OF A NW-SE ORIENTED FRONT
EXPECTED TO BE IN THE VICINITY WITHIN VERY MOIST CONDITIONS MAY ALSO
YIELD A COUPLE OF BRIEF TORNADOES/FUNNEL CLOUDS AS STORMS FIRST
INITIATE. EVENING STORMS WILL SETTLE SWD INTO ERN KS...BUT THE
SEVERE THREAT SHOULD WANE AFTER SUNSET.
...ERN DAKOTAS AND WRN/NRN MN...
NARROW BUT STRONG INSTABILITY AXIS WILL EVOLVE ACROSS THE REGION
FRIDAY AFTERNOON AS SURFACE DEW POINTS REMAIN IN THE UPPER 60S/LOWER
70S AND AIR MASS HEATS WELL INTO THE 90S. WHILE UPPER SUPPORT
REMAINS WEAK...ISOLATED THUNDERSTORMS MAY ERUPT ALONG A WEAK SURFACE
TROUGH...ESPECIALLY ACROSS ERN ND CLOSER TO A SRN CANADIAN MID-LEVEL
WAVE. SHOULD A STORM FORM...ROUGHLY 35-40 KTS OF DEEP LAYER SHEAR
WILL FAVOR STORM ORGANIZATION WITH LARGE HAIL AND DAMAGING WINDS
LIKELY. STORM COVERAGE IS NOT CLEAR...SO HAVE MAINTAINED ONLY LOW
SEVERE PROBABILITIES AT THIS TIME.
...NRN INTERMOUNTAIN WEST...
BELT OF 35-40 KT OF SWLY FLOW WILL EXIST DOWNSTREAM OF AN ERN
PACIFIC BASIN UPPER LOW OVER THE REGION ON FRIDAY. COMBINATION OF
SUFFICIENT MOISTURE AND WEAK CYCLONIC FLOW WILL BE FAVORABLE FOR
SCATTERED THUNDERSTORMS FROM PARTS OF ORE INTO ID. SUFFICIENT
VERTICAL SHEAR WILL EXIST FOR ISOLATED STRONG/SEVERE STORMS WITH
LARGE HAIL AND GUSTY WINDS.
..RACY.. 07/29/2010
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