[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 061624
SWODY1
SPC AC 061623

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1123 AM CDT THU APR 06 2006

VALID 061630Z - 071200Z

...THERE IS A HIGH RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR S/SE
NEB...ROUGHLY THE ERN HALF OF KS...AND A SMALL PART OF WRN MO....

...THERE IS A MDT RISK OF SVR TSTMS TODAY INTO TONIGHT FROM ERN
NEB/WRN IA SWD TO ERN OK AND WRN AR....

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT AND HIGH
RISK AREAS...FOR MUCH OF THE CENTRAL PLAINS TO THE MID MS VALLEY....

...SIGNIFICANT SEVERE WEATHER OUTBREAK EXPECTED THIS
AFTERNOON/EVENING FROM SE NEB ACROSS ERN KS/WRN MO INTO ERN OK AND
WRN AR...

...CENTRAL PLAINS THIS AFTERNOON INTO MO/AR TONIGHT...
WITHIN A BROAD MID LEVEL LOW OVER THE CENTRAL ROCKIES...AN INTENSE
MID LEVEL SHORTWAVE TROUGH IS ROTATING EWD FROM NM TOWARD OK/KS THIS
AFTERNOON.  A SURFACE CYCLONE NOW IN E CENTRAL NEB WILL PERSIST
TODAY...WITH ADDITIONAL CYCLOGENESIS EXPECTED INVOF SW INTO CENTRAL
KS IN RESPONSE TO 210 M HEIGHT FALLS AT 500 MB DURING THE AFTERNOON.
 THIS KS LOW SHOULD THEN ROTATE NNEWD TOWARD NEB THIS EVENING AND
EVOLVE INTO A DEEP OCCLUDED SYSTEM OVERNIGHT.

LOW-LEVEL MOISTURE CONTINUES TO SPREAD NWD FROM TX/LA/AR/OK NWD TO
WRN MO...KS/NEB.  REGIONAL 12Z SOUNDINGS REVEALED A PRONOUNCED EML
ABOVE THE MOIST LAYER...WITH MEAN BOUNDARY LAYER DEWPOINTS IN THE
UPPER 50S TO LOWER 60S.  GIVEN THE SHALLOW BOUNDARY LAYER OBSERVED
ACROSS S TX...AFTERNOON DEWPOINTS SHOULD GENERALLY REMAIN IN THE
60-62 F RANGE WITHIN THE WARM SECTOR...AS OPPOSED TO RECENT NAM
FORECASTS OF MID 60S.  VERY STEEP MID LEVEL LAPSE RATES...ALONG WITH
AN EROSION OF THE CAP FROM BELOW BY HEATING AND FROM THE W BY ASCENT
WITH THE APPROACHING WAVE...WILL SUPPORT AN INCREASING THREAT FOR
CONVECTIVE INITIATION BY 18-20Z NEAR THE PACIFIC COLD FRONT AND
DEVELOPING SECONDARY LOW INVOF CENTRAL KS.  STORMS SHOULD EXPAND IN
COVERAGE THROUGH THE AFTERNOON INTO S CENTRAL/SE NEB AND ERN
KS...WITH ADDITIONAL DEVELOPMENT POSSIBLE SWD ALONG THE PACIFIC COLD
FRONT IN OK TO THE E OF I-35 BY MID-LATE AFTERNOON.

WITH DAYTIME HEATING...MODERATE TO STRONG INSTABILITY IS EXPECTED
WITHIN THE INITIAL MID LEVEL DRY SLOT WHERE MLCAPE VALUES SHOULD
REACH 1500-2000 J/KG.  THE FORECAST ORIENTATION OF THE MID-UPPER
FLOW RELATIVE TO THE INITIATING SURFACE BOUNDARIES...ALONG WITH THE
STRONG FORCING WITH THE APPROACHING WAVE...SUGGEST THE POSSIBILITY
OF MIXED MODE CONVECTION WITH BOTH SUPERCELLS AND BOWING LINE
SEGMENTS ACROSS KS/NEB.  AFTERNOON TEMPERATURE- DEWPOINT SPREADS MAY
BE MARGINALLY LARGE FOR SIGNIFICANT TORNADOES...THOUGH FORECAST
HODOGRAPHS STILL APPEAR SUPPORTIVE OF TORNADOES.  OTHERWISE...LARGE
HAIL AND DAMAGING WINDS WILL BE LIKELY WITH THESE STORMS.  FARTHER S
AND LATER THIS AFTERNOON/EVENING...PROFILES APPEAR SUPPORTIVE OF
DISCRETE SUPERCELLS ACROSS ERN OK/AR/SRN MO INTO EARLY TONIGHT. 
TORNADOES WILL BE POSSIBLE WITH THESE STORMS...A FEW OF WHICH COULD
BE STRONG...GIVEN AN INCREASE IN LOW-LEVEL SHEAR THIS EVENING AND A
MORE MOIST ENVIRONMENT COMPARED TO AREAS FARTHER W AND N.  

...MS AND MO VALLEYS TODAY...
ELEVATED CONVECTION CONTINUES TO DEVELOP IN A SWATH FROM ERN SD TO
SE IA INTO MO/IL IN A REGION OF PRONOUNCED WAA.  STEEP MID LEVEL
LAPSE RATES AND LIMITED ELEVATED CAPE WILL SUPPORT A THREAT FOR
ISOLATED LARGE HAIL WITH THIS CONVECTION THROUGH THE AFTERNOON. 
FARTHER S...OTHER ELEVATED STORMS ARE FORMING ACROSS ERN OK/WRN AR
INTO NE TX.  LARGE HAIL WILL ALSO BE THE PRIMARY THREAT WITH THIS
ACTIVITY...THOUGH DAMAGING WINDS COULD BECOME POSSIBLE AS THE
BOUNDARY LAYER GRADUALLY DESTABILIZES.

..THOMPSON/TAYLOR.. 04/06/2006