[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 160556
SWODY2
SPC AC 160555

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT TUE MAY 16 2006

VALID 171200Z - 181200Z

...NO SVR TSTM AREAS FORECAST...

AMPLIFIED LARGE-SCALE UPPER PATTERN WILL PERSIST THROUGH THIS
FORECAST PERIOD AND BEYOND.  STRONGER FLOW WILL REMAIN SPLIT IN
BELTS AROUND BLOCKING RIDGE ENCOMPASSING MUCH OF THE INTERMOUNTAIN
WEST...BEFORE MERGING INTO A BROAD TROUGH EAST OF THE PLAINS INTO
THE WESTERN ATLANTIC.  MODELS SUGGEST THAT A CLOSED LOW EMBEDDED
WITHIN LATTER FEATURE WILL FINALLY LIFT NORTHEAST OF THE OHIO VALLEY
LATER TODAY/TONIGHT...BEFORE CONTINUING NORTHEASTWARD INTO THE
CANADIAN MARITIMES WEDNESDAY.  THIS WILL BE ACCOMPANIED BY THE
NORTHEASTWARD ACCELERATION OF A LOWER AMPLITUDE IMPULSE OUT OF THE
BASE OF THE LARGER SCALE TROUGH NEAR EASTERN GULF COASTAL
AREAS...THROUGH THE MID/SOUTH ATLANTIC COAST STATES BY LATE
WEDNESDAY NIGHT.  HOWEVER...AN UPSTREAM NORTHERN BRANCH SHORT WAVE
TROUGH/JET STREAK IS PROGGED TO SUPPORT THE EVOLUTION OF ANOTHER
CLOSED LOW AS IT DIGS OUT OF CENTRAL CANADA THROUGH THE UPPER GREAT
LAKES REGION.

...EAST OF THE ROCKIES...
THE PRIMARY FRONTAL ZONE ASSOCIATED WITH THE EASTERN TROUGH IS
EXPECTED OFF THE SOUTH ATLANTIC COAST...AND SOUTH/EAST OF THE
FLORIDA PENINSULA BY 12Z WEDNESDAY.  IN ITS WAKE...BOUNDARY LAYER
MOISTURE ACROSS MOST AREAS WILL BE SEASONABLY LOW.  THIS MAY NOT
PRECLUDE AREAS OF SCATTERED CONVECTIVE DEVELOPMENT...BUT POTENTIAL
FOR STRONG/SEVERE THUNDERSTORMS IS EXPECTED TO REMAIN LOW.

A LINGERING MID-LEVEL THERMAL TROUGH COULD PROVIDE THE FOCUS FOR
SCATTERED THUNDERSTORMS WITH DAYTIME HEATING ACROSS THE ATLANTIC
COAST STATES...MAINLY IN THE LEE OF THE CENTRAL/SOUTHERN
APPALACHIANS.  DIURNAL ACTIVITY IS POSSIBLE AS FAR TO THE SOUTH AND
WEST AS THE CENTRAL GULF STATES.  

HOWEVER...THE MAIN CONVECTIVE POTENTIAL WEDNESDAY SEEMS LIKELY TO
ACCOMPANY STRONGER MID/UPPER FORCING FOR UPWARD VERTICAL MOTION
AHEAD OF DIGGING UPPER GREAT LAKES SHORT WAVE TROUGH.  MODELS
SUGGEST LAPSE RATES COULD BECOME FAIRLY STEEP ABOVE LOW-LEVEL
THERMAL RIDGE IN ADVANCE OF REINFORCING COOL/DRY SURGE.  AND...
LOWER/MID 50S SURFACE DEW POINTS ARE GENERALLY EXPECTED TO
CONTRIBUTE TO MIXED LAYER CAPE AROUND 500 J/KG.  LOCALLY STRONGER
DESTABILIZATION IS POSSIBLE...SUPPORTING THE DEVELOPMENT OF
SCATTERED THUNDERSTORMS BY PEAK HEATING.  FAVORABLE DEEP LAYER SHEAR
ASSOCIATED WITH MODERATELY STRONG CYCLONIC MID-LEVEL FLOW IS
EXPECTED TO SUPPORT ONE OR MORE CONVECTIVE BANDS...WHICH PROBABLY
WILL BE ACCOMPANIED BY RISK OF GUSTY WINDS/HAIL WHICH COULD APPROACH
OR BRIEFLY EXCEED SEVERE LIMITS.  ACTIVITY SHOULD WEAKEN FAIRLY
QUICKLY AFTER DARK AS IT SPREADS EASTWARD THROUGH THE LOWER OHIO
VALLEY.

...ROCKIES AND INTERMOUNTAIN WEST...
MOISTURE...MOSTLY TO THE SOUTH/WEST OF UPPER HIGH CENTER...IS
EXPECTED TO REMAIN SUFFICIENT FOR SCATTERED THUNDERSTORM ACTIVITY
WEDNESDAY.  THIS WILL MOSTLY OCCUR IN RESPONSE TO HEATING ACROSS THE
HIGHER TERRAIN.  THOUGH POCKETS OF STRONGER INSTABILITY COULD
DEVELOP...CAPE IN WEAKLY SHEARED REGIME IS EXPECTED TO AVERAGE ON
THE ORDER OF A FEW HUNDRED J/KG.  THIS WILL LIMIT STRENGTH OF
UPDRAFTS...BUT STEEP LAPSE RATES WITH LARGE LOW-LEVEL
TEMPERATURE/DEW POINT SPREADS WILL PROVIDE FAVORABLE PROFILES FOR
HIGHLY LOCALIZED/ISOLATED MICROBURSTS.

..KERR.. 05/16/2006