DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 111625
SWODY1
SPC AC 111622

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1122 AM CDT TUE SEP 11 2007

VALID 111630Z - 121200Z

..THERE IS A SLGT RISK OF SVR TSTMS CENTRAL NY EWD INTO VT...

..SYNOPSIS...
A VIGOROUS UPPER TROUGH AND ASSOCIATED UNSEASONABLY STRONG MID/UPPER
WIND MAX WILL BE ROTATING ACROSS THE NERN CONUS THIS FORECAST
PERIOD. VERY COMPLEX SURFACE PATTERN COMBINED WITH EXTENSIVE CLOUD
COVER AHEAD OF THE PRIMARY FRONTAL BAND IS CREATING CONSIDERABLE
UNCERTAINTY IN THE CONVECTIVE POTENTIAL.

WHILE THE PRIMARY COLD FRONT CURRENTLY IS MOVING INTO WRN NY/PA...A
COUPLE SURFACE LOWS ARE DEVELOPING IN RESPONSE TO THE STRONG ASCENT
WITH APPROACHING UPPER TROUGH. STRONG WARM ADVECTION AHEAD OF
SURFACE LOW NERN PA AND ACROSS WARM FRONT SRN NEW ENGLAND COAST
PRODUCING AN EXPANDING AREA OF ELEVATED CONVECTIVE PCPN NEWD SRN NEW
ENGLAND.

ERN PA LOW FORECASTED TO MERGE WITH ANOTHER LOW OVER LO TONIGHT INTO
ONE DEEPENING SYSTEM MOVING NEWD ACROSS QUEBEC.

A SECONDARY TROUGH/COLD FRONT WILL BE MOVING EWD ACROSS LWR MI THIS
AFTERNOON IN CONCERT WITH THE VIGOROUS COLD UPPER TROUGH AND 100KT
500 WIND MAX.

..NERN U.S...
WILL CONTINUE A CONDITIONAL SEVERE THREAT FOR THIS AFTERNOON/EVENING
ACROSS NY INTO WRN NEW ENGLAND. OBVIOUSLY THE CURRENT CLOUD COVER
IS A MAJOR ISSUE...BUT WITH SOME HEATING AHEAD OF COLD
FRONT...MLCAPES COULD CLIMB TO 500 J/KG AS TEMPERATURES WARM INTO
LOW/MID 70S. 50-60KT OF MID LEVEL FLOW AND STRONG ASCENT WITH
APPROACH OF UPPER TROUGH/JET MAX...SHOULD PROMOTE DEVELOPMENT OF LOW
TOPPED THUNDERSTORMS LATER THIS AFTERNOON ALONG/AHEAD OF COLD FRONT.
STRONG POSSIBLY SEVERE WIND GUSTS ARE LIKELY AS STORMS EVOLVE INTO
SHORT LINE SEGMENTS ACROSS CENTRAL NY INTO WRN NEW ENGLAND.

..DELMARVA AREA...

SHARP SRN CLOUD EDGE FROM SRN NJ SWWD INTO CENTRAL VA. STRONG
HEATING WILL RAISE MLCAPES TO AOA 1000 J/KG TO S OF CLOUD BAND AND
LEAD TO DEVELOPMENT OF SURFACE STORM DEVELOPMENT BY MID AFTERNOON.
WITH 40-50 KT OF MID LEVEL FLOW EXPECT A FEW STRONG...ISOLATED
SEVERE STORMS WITH PRIMARILY A WIND THREAT.

..FL...
AIRMASS ACROSS MUCH OF FL PENINSULA VERY MOIST WITH PW/S AROUND 2
INCHES. GOOD DAYTIME HEATING ONGOING WILL RAISE MLCAPES TO AOA 2000
J/KG. OUTFLOW BOUNDARY FROM ERN GOM STORMS WILL BE MOVING INLAND
WRN COAST THIS AFTERNOON AND COUPLED WITH SEA BREEZE FRONTS SHOULD
LEAD TO STRONG ISOLATED SEVERE STORMS MUCH OF PENINSULA. PRIMARY
THREAT WILL BE WET MICROBURSTS AND SOME HAIL.

..NRN AZ/NRN NM INTO SWRN CO...
SUFFICIENT MOISTURE REMAINS AND WHEN COUPLED WITH THE AVAILABLE
STEEP LAPSE RATES AND STRONG HEATING FOR DIURNAL THUNDERSTORMS
PRIMARILY NEAR HIGHER TERRAIN. WHILE SHEAR IS WEAK THE LARGE DCAPES
UPWARDS TO 1500 J/KG AND DEEP BOUNDARY LAYER SUPPORTS
STRONG/ISOLATED SEVERE DOWNBURSTS. HAIL WILL ALSO BE POSSIBLE IN
STRONG CORES WITH 500MB TEMPS AROUND MINUS 10C.

.HALES/BROYLES.. 09/11/2007

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@PO.UIUC.EDU with
"unsub wx-storm" in the body of your message. For more information write chris@lib.siu.edu.