[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 191618
SWODY1
SPC AC 191616

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1116 AM CDT MON JUN 19 2006

VALID 191630Z - 201200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE OHIO VALLEY
INTO NEW ENGLAND...

...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF THE NORTHERN ROCKIES
AND PLAINS STATES...INTO THE MIDWEST...

...SYNOPSIS...
LARGE SCALE PATTERN EVOLVING INTO ZONAL FLOW ACROSS NRN CONUS WITH
EMBEDDED S/WV TROUGHS. ONE IMPULSE MOVING ENEWD ACROSS NERN U.S THIS
AFTERNOON WITH A TRAILING S/WV WRN GREAT LAKES MOVING ESEWD ACROSS
OH VALLEY CROSSING APPALACHIANS LATER TONIGHT. FURTHER UPSTREAM
TROUGH PAC NW DEAMPLIFIES AND QUICKLY TRACKS ACROSS NRN ROCKIES TO
NRN HIGH PLAINS BY 12Z TUE.

...NERN U.S...
MOIST AND MDT TO STRONGLY UNSTABLE AIR MASS HAS SPREAD ACROSS MUCH
OF NERN U.S. AHEAD OF S/WV TROUGH MOVING ENEWD CURRENTLY WRN NY/PA. 
WITH 35-40KT OF PRIMARILY UNIDIRECTIONAL SHEAR COUPLED WITH MLCAPES
CLIMBING TO 2500 J/KG...THUNDERSTORMS WILL QUICKLY DEVELOP AND
INTENSIFY ALONG AND AHEAD OF CURRENT BAND OF CONVECTION FROM WRN NY
SWWD.  GIVEN ONLY MODEST LAPSE RATES AND SHEAR...PRIMARY STORM MODE
EXPECTED TO BE SHORT LINE SEGMENTS/BOW WITH WIND DAMAGE POTENTIAL. 
SUFFICIENT LOW LEVEL VEERING FOR ISOLATED TORNADO THREAT ASSOCIATED
WITH EITHER BOWS OR SUPERCELLS THAT COULD DEVELOP IN WARM SECTOR.

SEVERE THREAT WILL EXTEND EWD REACHING NEW ENGLAND COAST THIS
EVENING PRIOR TO WEAKENING AS THEY ENCOUNTER MARINE AIR MASS.

...OH VALLEY EWD TO APPALACHIANS...
LEADING EDGE OF DRIER AND A LITTLE COOLER AIR EXTENDS FROM CENTRAL
LOWER MI SWWD TO CENTRAL IL AND WILL CONTINUE TO SPREAD SEWD.  S/WV
TROUGH NOTED IN W/V IMAGERY CURRENTLY MOVING ESEWD WITH ASSOCIATED
MID LEVEL 50KT WIND MAX AND STEEPER LAPSE RATES WILL CROSS OH VALLEY
THIS AFTERNOON/EVENING AND SUPPORT STRONG/SEVERE THUNDERSTORM
DEVELOPMENT AS IT ENCOUNTERS THE MOIST/UNSTABLE AIR MASS.  WITH
MLCAPES TO 2000 J/KG...LAPSE RATES AROUND 7C/KM AND 35-40KT OF
SHEAR...A FEW SUPERCELLS ARE LIKELY.  PRIMARY THREAT WILL BE LARGE
HAIL AND DAMAGING WINDS WITH ISOLATED TORNADOES POSSIBLE WITH ANY
SUPERCELL THAT DEVELOPS.

...NRN ROCKIES EWD ACROSS ADJACENT HIGH PLAINS...
WHILE LOW LEVEL MOISTURE IS MARGINAL AHEAD OF APPROACHING S/WV
TROUGH THE COMBINATION OF STEEPENING LAPSE RATES AND 50-60KT OF DEEP
LAYER SHEAR COUPLED WITH LARGE SCALE ASCENT...WILL INITIATE
RELATIVELY HIGH BASED THUNDERSTORMS BY MID AFTERNOON OVER HIGHER
TERRAIN SRN MT/NRN BORDER AREAS OF WY. HAIL AND WIND DAMAGE WILL BE
A THREAT WITH STRONGER UPDRAFTS AS ACTIVITY DEVELOPS INTO LOWER
ELEVATIONS OF SERN MT AND EVENTUALLY INTO NRN HIGH PLAINS.

...E SLOPES CO/WY...
SELY LOW LEVEL FLOW SPREADING MOISTURE INTO ERN WY/WRN NE/SD. 
STRONG HEATING AND FAVORABLE VEERING SHEAR PROFILES WILL BE
SUFFICIENT GIVEN EXPECTED MLCAPES TO AT LEAST 1000 J/KG FOR A FEW
SUPERCELLS TO DEVELOP OFF HIGHER TERRAIN NERN CO/ERN WY DURING
AFTERNOON.  IN ADDITION TO LARGE HAIL ISOLATED TORNADOES WILL ALSO
BE POSSIBLE GIVEN THE FAVORABLE SHEAR PROFILES. STORMS WILL
PROPAGATE EWD ACROSS SD/NE OVERNIGHT UNDER A FAVORABLE WARM
ADVECTION REGIME AS LOW LEVEL JET INCREASES TO 50KT KS INTO NEB.

..HALES/GRAMS.. 06/19/2006