[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 241658
SWODY2
SPC AC 241657

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1157 AM CDT MON APR 24 2006

VALID 251200Z - 261200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN TX AND THE LOWER MS
VALLEY NEWD TO PORTIONS OF THE DELMARVA AND NC...

...SYNOPSIS...

AMPLIFIED...SPLIT FLOW PATTERN WILL CONTINUE THROUGH THE DAY TWO
PERIOD WITH DEEP UPPER LOW EVOLVING OVER THE ERN CANADA AND SRN
STREAM LOW SHIFTING SEWD ALONG THE SRN CA COAST.  SHORT WAVE TROUGH
EJECTING EWD INTO THE CNTRL AND SRN PLAINS DURING THE DAY ONE PERIOD
IS FORECAST TO WEAKEN AS IT MOVES INTO PROGRESSIVELY CONFLUENT
MID-LEVEL FLOW REGIME FROM THE SRN OH VALLEY TO MIDDLE ATLANTIC
COAST.

IN THE LOW-LEVELS...PRIMARY SURFACE LOW ASSOCIATED WITH PLAINS SHORT
WAVE TROUGH /INITIALLY OVER THE MID MS VALLEY/ WILL DEVELOP RAPIDLY
EWD ALONG BAROCLINIC ZONE TO NEAR CHESAPEAKE BAY BY TUESDAY EVENING.
MEANWHILE...TRAILING COLD FRONT WILL PUSH SEWD THROUGH THE REMAINDER
OF TX AND THE LOWER MS VALLEY BY WEDNESDAY MORNING.

...SERN TX/LOWER MS VALLEY EWD INTO THE CNTRL AND SRN
APPALACHIANS...

CURRENT SURFACE OBSERVATIONS AND 24/12Z SOUNDING DATA INDICATE A
MOIST LOW-LEVEL AIR MASS IN PLACE ACROSS THE SRN PLAINS INTO WRN
PORTIONS OF THE LOWER MS VALLEY WITH DEWPOINTS IN THE 60S TO LOWER
70S.  INCREASING SWLY LOW-LEVEL FLOW AHEAD OF SURFACE FRONT WILL
ALLOW FOR EWD/NEWD ADVECTION OF THIS MOISTURE ACROSS THE GULF COAST
INTO TN VALLEY...SUPPORTING MODERATE AFTERNOON INSTABILITY WITH
MLCAPES INCREASING TO 1000-2000 J/KG.  THIS INSTABILITY WILL WEAKEN
WITH NEWD EXTENT OVER THE APPALACHIANS WHERE MLCAPES OF 500-1000
J/KG APPEAR MORE LIKELY.

CLUSTERS OF TSTMS OR A COUPLE OF MCS/S WILL LIKELY BE ONGOING
TUESDAY MORNING FROM VICINITY OF SURFACE LOW SWWD ALONG COLD FRONT
FROM THE LOWER OH VALLEY INTO AR.  SOME DIURNAL WEAKENING MAY OCCUR
THROUGH THE MORNING...WITH STORMS EXPECTED TO INCREASE IN COVERAGE
AND INTENSITY BY AFTERNOON AS INFLOW AIR MASS DESTABILIZES.  GIVEN
THE ANTICIPATED MODERATE INSTABILITY...DEEP-LAYER SPEED SHEAR OF
35-40 KTS SHOULD BE SUFFICIENT TO SUPPORT ORGANIZED STORM CLUSTERS
AND/OR LINE SEGMENTS CAPABLE OF MAINLY DAMAGING WINDS AND LARGE
HAIL.

...DELMARVA INTO NC...

CURRENT SURFACE OBSERVATIONS AND MODEL GUIDANCE SUGGEST THAT
BOUNDARY-LAYER WILL LIKELY NOT BE AS MOIST AS LOCATIONS FARTHER TO
THE W...THOUGH DEWPOINTS SHOULD INCREASE THROUGH THE 50S AS SLY
LOW-LEVEL WINDS INCREASE AHEAD OF APPROACHING SURFACE LOW.  WHILE
FORECAST SOUNDINGS INDICATE THAT INSTABILITY WILL REMAIN SOMEWHAT
MARGINAL /MLCAPES OF 500-800 J/KG/...VERTICAL SHEAR PROFILES WILL BE
QUITE FAVORABLE FOR SEVERE STORMS WITH 40-50 KTS OF DEEP-LAYER SHEAR
AND MORE STRONGLY CURVED LOW-LEVEL HODOGRAPHS OWING TO BACKED WINDS
AHEAD OF SURFACE LOW.

THEREFORE...SHOULD STORMS DEVELOP AND BECOME SUSTAINED NEAR SURFACE
LOW...POTENTIAL WILL EXIST FOR DAMAGING WINDS...LARGE HAIL AND
PERHAPS A TORNADO OR TWO FROM MID TO LATE AFTERNOON INTO THE EARLY
EVENING HOURS.

..MEAD.. 04/24/2006