[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 151729
SWODY2
SPC AC 151728

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT SAT APR 15 2006

VALID 161200Z - 171200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE OH
VALLEY...CNTRL APPALACHIANS AND ATLANTIC COASTAL PLAINS...

...OH VALLEY/CNTRL APPALACHIANS/ATLANTIC COASTAL PLAINS...
A NEGATIVELY-TILTED UPPER-LOW OVER THE PLAINS STATES WILL SLOWLY
FILL AND DRIFT EWD TOWARD THE OH VALLEY SUNDAY. LARGE-SCALE ASCENT
AHEAD OF THE SYSTEM WILL SUPPORT THE DEVELOPMENT OF SCATTERED TO
NUMEROUS THUNDERSTORMS ACROSS THE REGION SUNDAY AND SUNDAY NIGHT.

A LARGE MCS WILL LIKELY BE ONGOING AT THE BEGINNING OF THE PERIOD
ACROSS WI...IL AND IND DURING THE MORNING AHEAD OF THE APPROACHING
UPPER-TROUGH. SFC DEWPOINTS SHOULD BE IN THE LOWER 60S ACROSS MUCH
OF THE OH VALLEY ALLOWING MODERATE INSTABILITY TO DEVELOP BY SUNDAY
AFTERNOON SOUTH OF THE MCS WHERE THE AIRMASS SHOULD REMAIN
UNDISTURBED. SUBSTANTIAL DESTABILIZATION ALSO APPEARS LIKELY WEST OF
THE EXITING MCS ACROSS IA AND NRN IL NEAR A SFC LOW ASSOCIATED WITH
THE UPPER SYSTEM. THIS WOULD BE THE MOST LIKELY AREA FOR STRONG
CONVECTIVE INITIATION EARLY SUNDAY AFTERNOON WITH STORMS EXPANDING
IN COVERAGE DURING THE AFTERNOON ALONG A STATIONARY FRONTAL BOUNDARY
EXTENDING ESEWD FROM THE SFC LOW. MCS DEVELOPMENT WITH THIS
CONVECTIVE COMPLEX APPEARS LIKELY LATE SATURDAY AFTERNOON WITH
STORMS MOVING ACROSS NCNTRL IL INTO IND...NRN KY AND SRN OH DURING
THE EVENING HOURS.

FORECAST SOUNDINGS LATE SUNDAY AFTERNOON ACROSS THE REGION SHOW
MODERATE INSTABILITY WITH 40 TO 50 KT OF VERTICAL SHEAR AND STEEP
MID-LEVEL LAPSE RATES SUGGESTING SUPERCELLS WITH LARGE HAIL AND WIND
DAMAGE WILL BE LIKELY. DUE TO THE MODERATE INSTABILITY AND COLDER
AIR ALOFT WITH THE UPPER-TROUGH...VERY LARGE HAIL APPEARS POSSIBLE
WITH THE STRONGER SUPERCELLS IN THE LATE AFTERNOON AND EARLY
EVENING. A POTENTIAL FOR TORNADOES WILL ALSO EXIST AS SUPERCELLS
INCREASE IN COVERAGE AND A LARGE MCS DEVELOPS IN THE EVENING. DUE TO
THE UNSTABLE AIRMASS AND MODERATE VERTICAL SHEAR...THE MCS SHOULD
CONTINUE TO DRIFT ESEWD OVERNIGHT WITH A LOW-END SEVERE THREAT
POSSIBLE INTO THE CNTRL APPALACHIAN MTNS AND ATLANTIC COASTAL PLAINS
LATE IN THE PERIOD.

...ERN MT/FAR WRN ND...
A BROAD BAND OF SOUTHWEST FLOW ACROSS THE NWRN U.S. WILL REMAIN IN
PLACE SUNDAY. SEVERAL SHORTWAVE TROUGHS EMBEDDED IN THE FLOW WILL
DRIFT NEWD ACROSS THE NRN PLAINS SUNDAY AND SUNDAY NIGHT. ALTHOUGH
FORECAST SOUNDINGS LATE SUNDAY AFTERNOON ACROSS THE REGION SHOW WEAK
INSTABILITY IN PLACE...STEEPENING LAPSE RATES AND LARGE-SCALE ASCENT
AHEAD OF ANY SHORTWAVE WOULD MAKE MARGINALLY SEVERE HAIL STORMS
POSSIBLE. ANY MARGINAL SEVERE THREAT WOULD LIKELY BE TIED CLOSELY TO
SFC HEATING.

..BROYLES.. 04/15/2006