[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 101634
SWODY1
SPC AC 101632

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1132 AM CDT WED MAY 10 2006

VALID 101630Z - 111200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF EXTREME SERN
AR...NERN LA...CENTRAL AND SRN MS...CENTRAL AND SRN AL...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE GULF COASTAL STATES
NWD ACROSS THE MS/TN AND OH VALLEY REGION...

...TORNADOES...A FEW STRONG..ARE POSSIBLE ACROSS PORTIONS OF THE
CENTRAL GULF STATES THIS AFTERNOON AND EVENING ACROSS THE SOUTH
CENTRAL GULF COAST STATES...

UPPER TROUGH OVER THE CENTRAL PLAINS WILL DEEPEN AND SHIFT EWD INTO
MID MS/OH VALLEYS TONIGHT. A COLD FRONT WILL SWEEP RAPIDLY THROUGH
THE MS VALLEY REGION TODAY AND INTO THE OH/TN VALLEYS AND CENTRAL
GULF REGION TONIGHT. A WEAK LOW ALONG THE FRONT IS FORECAST TO
DEEPEN OVER THE OHIO VALLEY TONIGHT.

LOWER/MID MS VALLEY EWD THROUGH THE CENTRAL GULF COASTAL STATES AND
TN VALLEY...

THREE MCS CLUSTERS WERE LOCATED FROM AL TO AR THIS MORNING. THE
LEADING CLUSTER WAS WEAKENING IN SRN AL...THE SECOND ONE WAS MOVING
THROUGH NRN MS INTO NWRN AL...AND THE THIRD AND MOST INTENSE CLUSTER
WAS MOVING THROUGH SRN/CENTRAL AR. A BOUNDARY... SEPARATING RAIN
COOLED AIR TO THE NORTH AND A WARM SECTOR TO THE SOUTH WITH MLCAPES
IN EXCESS OF 3000 J/KG...EXTENDED FROM SERN AR ESEWD ACROSS CENTRAL
MS INTO SWRN AL. ALTHOUGH THE AIR MASS ACROSS THE WARM SECTOR IS
CURRENTLY CAPPED...STRONG FORCING AND 50-60 KT DEEP LAYER SHEAR HAS
RESULTED IN INTENSE STORMS/SUPERCELLS WITHIN THE AR THUNDERSTORM
LINE. WITH ADDITIONAL HEATING AND INCREASING LARGE SCALE LIFT...IN
RESPONSE TO SHORTWAVE TROUGH MOVING EWD OUT OF OK...STORMS ARE
LIKELY TO BECOME ROOTED IN THE BOUNDARY LAYER AND TAP INTO THE
STRONG INSTABILITY. THE DEGREE OF INSTABILITY... DEEP LAYER SHEAR
AND 30-40 KT 1 KM SHEAR...WILL FAVOR INTENSE SUPERCELLS WITH THE
POTENTIAL FOR VERY DAMAGING WINDS...LARGE HAIL AND STRONG TORNADOES
ACROSS THE MODERATE RISK AREA THIS AFTERNOON/EVENING.

THE MORNING MCS CLUSTERS RESULTED IN EXTENSIVE CLOUDS AND A RAIN
COOLED BOUNDARY LAYER SURROUNDING THE TN VALLEY. THIS WILL LIMIT THE
NWD EXTENT OF THE STRONGER INSTABILITY ACROSS PORTIONS OF NRN MS/AL
NWD INTO SRN KY. THOUGH SCATTERED SEVERE STORMS ARE EXPECTED TO
DEVELOP ACROSS THESE AREAS THIS AFTERNOON AS THE UPPER TROUGH AND
ASSOCIATED COLD FRONT APPROACHES FROM THE WEST...THE COOL BOUNDARY
LAYER SHOULD RESULT IN MOSTLY ELEVATED STORMS WITH MAINLY A SEVERE
HAIL AND WIND THREAT.

...OH VALLEY...
A LARGE CLOUD SHIELD AND SOME PRECIPITATION WILL SPREAD NWD ACROSS
THE REGION THROUGHOUT THE AFTERNOON AND INHIBIT STRONG STORM
DEVELOPMENT THROUGH MOST OF THE DAY. HOWEVER...AS THE UPPER TROUGH
APPROACHES ALONG WITH A 70 KT MID LEVEL WIND MAX...SURFACE LOW IS
FORECAST TO MOVE FROM SRN INDIANA NWD INTO WRN OH AND DEEPEN.
ALTHOUGH INSTABILITY WILL BE WEAK DUE TO DEEP MOIST VERTICAL
PROFILES...BACKING BOUNDARY LAYER WINDS AND STRENGTHENING WINDS
ALOFT WILL BECOME MORE FAVORABLE FOR SUPERCELLS AND TORNADOES. THE
BIGGEST CONCERN ABOUT A HIGHER RISK ATTM IS THE CURRENT FORECAST OF
POOR LAPSE RATES. HOWEVER...THE WIND PROFILES AND PRESSURE FALLS MAY
SUPPORT A TORNADO TREAT ACROSS PORTIONS OF INDIANA AND OH OVERNIGHT.


...SERN MO AND SRN IL...
AS ONE SHORTWAVE TROUGH LIFTS NEWD ACROSS THE REGION THIS
AFTERNOON...SOME HEATING MAY AID IN THE DEVELOPMENT OF STRONGER
STORMS ALONG AND AHEAD OF THE COLD FRONT. THE BOUNDARY LAYER SHOULD
REMAIN RELATIVELY COOL...BUT 30-40 KT DEEP LAYER SHEAR AND MLCAPES
UP TO 1000 J/KG WILL SUPPORT SOME STORMS WITH SEVERE HAIL/WIND.

..IMY.. 05/10/2006