[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 261617
SWODY1
SPC AC 261615

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1115 AM CDT WED JUL 26 2006

VALID 261630Z - 271200Z

...THERE IS A SLGT RISK OF SVR TSTMS MID MS VALLEY TO GREAT LAKES
REGION...

...THERE IS A SLGT RISK OF SVR TSTMS ERN TX AND LA...

...SYNOPSIS...
AS UPPER HIGH IN THE W HAS GRADUALLY WEAKENED A WNWLY FLOW WITH
SEVERAL EMBEDDED S/WV TROUGHS PREVAILS ACROSS THE NRN TIER OF THE
CONUS. THE STRONGEST IMPULSE CURRENTLY MOVING EWD ACROSS THE UPPER
GREAT LAKES AND OH VALLEY. A RATHER WEAK SURFACE FRONTAL ZONE
EXTENDS FROM UPPER MI SWWD ACROSS SRN MN TO NERN CO.

A TROPICAL LOW PRESSURE CENTER HAS MOVED INLAND FROM NWRN GULF TO A
POSITION NW OF VCT ATTM.  A MDTLY STRONG SLY FLOW OF TROPICAL AIR
CONTINUES TO STREAM INLAND ACROSS ERN TX/WRN LA.

...MID MS VALLEY AND GREAT LAKES REGION...
MUCH OF THREAT AREA IS CURRENTLY CLOUD COVERED WHICH WILL DELAY
SEVERE THUNDERSTORM DEVELOPMENT UNTIL LATER THIS AFTERNOON. 
STRONGER BAND OF DEEP LAYER SHEAR ASSOCIATED WITH THE UPPER S/WV
TROUGH MOVING ACROSS THIS AREA WILL SUPPORT MULTICELL THUNDERSTORMS
ONCE AIR MASS CAN DESTABILIZE WITH AFTERNOON HEATING.  THE AIR MASS
IS VERY MOIST ACROSS THIS REGION AND WILL JUST REQUIRE SUFFICIENT
HEATING TO WEAKEN CIN TO ALLOW SURFACE BASED STORMS TO DEVELOP. 
SURFACE CONVERGENCE IS RATHER WEAK BUT THE FRONTAL ZONE AS WELL AS
OUTFLOW BOUNDARIES FROM OVERNIGHT CONVECTION SHOULD FOCUS INITIATION
BY MID/LATE AFTERNOON. PRIMARY THREAT WILL BE LOCAL DAMAGING WIND
AND MARGINALLY SEVERE HAIL GIVEN THE MULTICELL NATURE OF THE
CONVECTION.

...ERN TX/LA...
WITH THE MODELS INDICATING THE LOW LEVEL CIRCULATION NOW ONSHORE 
SCENTRAL TX CONTINUING A SLOW NNEWD MOVEMENT ACROSS ERN TX THIS
FORECAST PERIOD...A THREAT OF TROPICAL SUPERCELLS WILL CONTINUE AND
SHIFT INLAND AS WELL.  20-30KT OF SFC-1KM SHEAR AND HELICITIES
UPWARDS TO 200 M2/S2 EXPECTED TO MAINTAIN A THREAT OF SUPERCELLS AND
ISOLATED TORNADOES. THE CURRENT THREAT AREA SERN TX/SWRN LA COAST
WILL SHIFT INLAND THIS AFTERNOON IN CONCERT WITH THE LOW MOVEMENT.

...SWRN U.S...
TUESDAYS GULF SURGE FOLLOWED BY ACTIVE OVERNIGHT CONVECTION SRN AZ
HAS TRANFORMED MUCH OF THE AZ DESERTS AIR MASS INTO A VERY MOIST AND
MODERATELY UNSTABLE ENVIRONMENT.  THE STABILIZING EFFECT OF THE
NIGHTTIME ACTIVITY WILL REDUCE SOMEWHAT THE THREAT OF SEVERE
THUNDERSTORMS TODAY.  HOWEVER WITH THE MID CLOUD COVER
EVAPORATING...HEATING EXPECTED TO BE SUFFICIENT TO ALLOW MLCAPES TO
CLIMB BACK TO NEAR 2000 J/KG BY LATER THIS AFTERNOON.  STEERING FLOW
IS GENERALLY LESS THAN 10KT.  STORMS WILL INITIATE OVER HIGHER
TERRAIN AND SLOWLY DEVELOP INTO LOWER ELEVATIONS LATER THIS
AFTERNOON/EVENING.  STILL A THREAT OF ISOLATED WIND/HAIL...HOWEVER
WITH SOME DECREASE IN LAPSE RATES FROM THE PREVIOUS DAYS...ORGANIZED
SEVERE THREAT IS NOT ANTICIPATED.

...INTERIOR NERN U.S...
NEARLY FULL HEATING COUPLED WITH A MOIST AIR MASS WILL SUPPORT
THUNDERSTORM DEVELOPMENT OVER HIGHER TERRAIN BY MID AFTERNOON FROM
PA NEWD ACROSS NEW ENGLAND.  WITH SHEAR GENERALLY LESS THAN
15KT...PULSE STORMS SHOULD BE THE PREDOMINANT MODE...WITH LOCAL
GUSTY WINDS AND MARGINALLY SEVERE HAIL.

...SERN COASTAL AREAS...
FULL HEATING AND A MOIST AIR MASS WILL LEAD TO MLCAPES TO ABOVE 2000
J/KG. SUFFICIENT SHEAR UP TO 20KT AND STEEP LOW LEVEL LAPSE
RATES...SHOULD RESULT IN A FEW STRONG/SEVERE STORMS THIS AFTERNOON.
PRIMARY AREA OF DEVELOPMENT SHOULD BE VICINITY OF SEA BREEZE FRONT
COASTAL SC.

..HALES/JEWELL.. 07/26/2006