[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 172001
SWODY1
SPC AC 172000

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT SAT JUN 17 2006

VALID 172000Z - 181200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL/SRN PLAINS
INTO LOWER MS VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MIDWEST AND
WESTERN GREAT LAKES...

...CENTRAL/SRN PLAINS...
ELONGATED UPPER TROUGH WILL CONTINUE TO MOVE EWD ACROSS THE CENTRAL/
SRN PLAINS THIS FORECAST PERIOD...WITH STRONGER MID LEVEL FLOW
EXPECTED TO REMAIN LOCATED ALONG THE SRN TO ERN PERIPHERY OF THIS
TROUGH.  ALTHOUGH COOL MID LEVEL TEMPERATURES /-10 TO -12 C AT 500
MB/ EXTEND N-S ACROSS THE CENTRAL/SRN PLAINS...STEEPEST MID LEVEL
LAPSE RATES IN EXCESS OF 7.5-8 C/KM WERE ASSOCIATED WITH THE SRN
EXTENT OF THE UPPER TROUGH ACROSS OK/TX.  THESE LAPSE RATES COMBINED
WITH STRONG SURFACE HEATING ESPECIALLY FROM SWRN OK INTO CENTRAL/WRN
TX WITHIN MOIST ENVIRONMENT WILL CONTINUE TO RESULT IN STRONG
INSTABILITY WITH MLCAPE VALUES UP TO 2000-3000 J/KG INTO THE LATE
AFTERNOON/EARLY EVENING.  FARTHER N...INSTABILITY IS EXPECTED TO
REMAIN WEAKER /MLCAPE BELOW 1000 J/KG/ FROM CENTRAL NEB INTO CENTRAL
KS.

THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG THE SURFACE TROUGH
WHICH EXTENDED FROM CENTRAL NEB/KS INTO CENTRAL/WRN OK TO NW-W TX. 
HOWEVER...MOST VIGOROUS CONVECTION AND GREATEST SEVERE THREAT IS
EXPECTED TO REMAIN FROM TX/OK INTO SRN KS WHERE STRONG INSTABILITY
AND DEEP LAYER SHEAR ARE BEST FOR ORGANIZED SEVERE STORMS. 
SUPERCELLS WILL BE POSSIBLE WITH HAIL/DAMAGING WINDS THE PRIMARY
THREATS.  A FEW TORNADOES WILL BE POSSIBLE...ESPECIALLY ACROSS PARTS
OF OK WHERE LCLS WILL BE LOWER AND LOW LEVEL SHEAR IS STRONGER.

SEVERE THUNDERSTORMS ARE LIKELY TO CONTINUE WELL AFTER DARK...
PARTICULARLY CENTRAL/SRN TX WHERE DEEP LAYER SHEAR AND INSTABILITY
WILL BE THE GREATEST...WITH ACTIVITY LIKELY DEVELOPING SSEWD.

...MN/WI/MI...
STRONG SURFACE HEATING ALONG/S OF A BAROCLINIC ZONE WHICH EXTENDED
FROM CENTRAL MN NEWD ACROSS THE NRN U.P. OF MI HAS RESULTED IN
MODERATE INSTABILITY /MLCAPE AOA 1000 J/KG/ THIS AFTERNOON.  DEEP
LAYER ASCENT ACROSS THIS REGION WITHIN ENTRANCE REGION OF STRONG MID
LEVEL JET WHICH EXTENDED FROM LAKE SUPERIOR INTO ONTARIO AND WAA
ALONG NOSE OF SLY LLJ IS EXPECTED TO AID IN ADDITIONAL STORMS. DEEP
LAYER SHEAR ALONG SRN PERIPHERY OF STRONG MID LEVEL FLOW WILL
CONTINUE TO SUPPORT ORGANIZED STORMS ACROSS FAR NRN WI INTO U.P. OF
MI WITH SOME POTENTIAL FOR DEVELOPMENT FARTHER W INTO ERN MN.

...E TX/LOWER AND MID MS VALLEY...
EXTENSIVE AREA OF THUNDERSTORM COVERAGE IS EXPECTED TO PERSIST FROM
THE UPPER TX COAST NEWD THROUGH THE LOWER TO MID MS VALLEY FOR MUCH
OF THE FORECAST PERIOD...WITHIN ZONE OF DEEP MOIST SSWLY FLOW
REGIME.  LARGE SCALE ASCENT AHEAD OF TWO MID LEVEL FEATURES...ONE AN
MCV NOW LOCATED OVER NERN TX AND THE SECOND A WEAKENING IMPULSE
LOCATED OVER SERN MO WILL SUPPORT THIS ACTIVITY.  ALTHOUGH THE AIR
MASS IS MODERATELY UNSTABLE...WEAK DEEP LAYER SHEAR SUGGESTS THESE
STORMS SHOULD REMAIN MOSTLY SUB-SEVERE...WITH SOME POTENTIAL FOR
LOCALLY ISOLATED DAMAGING WINDS.

..PETERS.. 06/17/2006