[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 011721
SWODY2
SPC AC 011720

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1220 PM CDT SAT JUL 01 2006

VALID 021200Z - 031200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE HIGH
PLAINS...CNTRL PLAINS...OH VALLEY...NRN APPALACHIAN
MTNS...MID-ATLANTIC AND NEW ENGLAND...

...OH VALLEY...
WEST TO NORTHWEST FLOW WILL REMAIN IN PLACE THROUGH SUNDAY ACROSS
THE NRN US WITH A BROAD UPPER-LEVEL TROUGH OVER SERN CANADA AND THE
GREAT LAKES REGION. MODEL FORECASTS BRING SEVERAL MINOR SHORTWAVE
TROUGHS ACROSS THE REGION SUNDAY WHICH SHOULD PROVIDE SUPPORT FOR
SCATTERED TO NUMEROUS THUNDERSTORMS ALONG A QUASI-STATIONARY FRONTAL
BOUNDARY SITUATED FROM IA EXTENDING EWD ACROSS NRN IL...NRN IND AND
OH.

BOTH THE WRF AND GFS DEVELOP A POCKET OF MODERATE TO STRONG
INSTABILITY ACROSS THE NRN OH VALLEY ALONG AND JUST SOUTH OF THE
FRONT. IN ADDITION...FORECAST SOUNDINGS SHOW MODERATE VERTICAL SHEAR
SUGGESTING THE ENVIRONMENT WILL BE FAVORABLE FOR SUPERCELLS AND/OR
BOW ECHOES. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE WITH THE
STRONGER STORMS IN THE LATE AFTERNOON AND EARLY EVENING. AS STORM
COVERAGE EXPANDS DURING THE EVENING...THE WIND DAMAGE POTENTIAL MAY
BECOME ENHANCED WITH ANY MCS THAT ORGANIZES AND TRACKS SEWD ACROSS
THE REGION.

...NERN US...
A BROAD SERN CANADA UPPER-LEVEL TROUGH WILL REMAIN IN PLACE THROUGH
SUNDAY AS A 70 KT MID-LEVEL JET DRIFTS EWD ACROSS SRN QUEBEC.
LARGE-SCALE ASCENT ASSOCIATED WITH THE UPPER-TROUGH AND LIFT FROM
THE RIGHT REAR QUADRANT OF THE MID-LEVEL JET SHOULD SUPPORT STRONG
THUNDERSTORM DEVELOPMENT ACROSS THE REGION SUNDAY AFTERNOON.
THUNDERSTORMS WILL LIKELY INITIATE IN THE NRN APPALACHIAN MTNS AND
SPREAD EWD INTO THE MID-ATLANTIC AND SRN NEW ENGLAND BY LATE
AFTERNOON.

MODEL FORECASTS SHOW AN AXIS OF MODERATE INSTABILITY EXTENDING NWD
THROUGH NJ INTO THE NEW YORK CITY AREA. THIS COMBINED WITH 30 TO 40
KT OF MID-LEVEL FLOW SHOULD PROVIDE VERTICAL SHEAR SUFFICIENT FOR
SUPERCELLS AND/OR BOW ECHOES. UNIDIRECTIONAL WIND PROFILES AND STEEP
LOW-LEVEL LAPSE RATES WILL FAVOR WIND DAMAGE AS THE MOST WIDESPREAD
THREAT ALTHOUGH HAIL WILL ALSO BE POSSIBLE WITH THE STRONGER CELLS.

...HIGH PLAINS/CNTRL PLAINS...
WEST TO NORTHWESTERLY FLOW WILL REMAIN IN PLACE ACROSS THE REGION
TONIGHT INTO SUNDAY. AT THE SFC...UPSLOPE FLOW WILL CONTINUE ACROSS
NEB...NERN CO AND SERN WY. THIS WILL REINFORCE 50S TO LOWER 60S F
DEWPOINTS IN THE HIGH PLAINS. THUNDERSTORMS WILL LIKELY INITIATE IN
THE HIGHER TERRAIN OF SERN WY AND NERN CO WITH ADDITIONAL
DEVELOPMENT POSSIBLE IN THE CNTRL PLAINS ALONG ANY PREEXISTING
BOUNDARIES AS SFC TEMPS WARM DURING THE DAY. FORECAST SOUNDINGS
SUNDAY AFTERNOON ACROSS THE REGION SHOW 0-6 KM SHEAR VALUES IN THE
30 TO 40 KT RANGE MAINLY FROM STRONG VEERING IN THE LOW TO
MID-LEVELS. THIS COMBINED WITH MODERATE INSTABILITY WILL BE
SUFFICIENT FOR SUPERCELLS. VERY STEEP MID-LEVEL LAPSE RATES WILL
FAVOR LARGE HAIL AS THE GREATEST THREAT...ALTHOUGH ISOLATED WIND
DAMAGE WILL ALSO BE POSSIBLE ESPECIALLY ALONG THE LEADING EDGE OF
ANY MCS THAT ORGANIZES AND MOVES EWD ACROSS THE REGION IN THE
EVENING.

..BROYLES.. 07/01/2006