[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 080554
SWODY1
SPC AC 080552

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1152 PM CST TUE MAR 07 2006

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE LOWER
MO/OH VALLEY SWWD INTO THE SRN PLAINS...

...SYNOPSIS...

DYNAMIC...MID-LEVEL TROUGH CURRENTLY DIGGING SEWD INTO THE LOWER CO
VALLEY WILL CONTINUE SEWD TODAY THROUGH AZ/NM AND NRN MEXICO...PRIOR
TO SHIFTING MORE EWD INTO THE SRN PLAINS TONIGHT.  ACCOMPANYING MID
AND HIGH-LEVEL JET STREAKS WILL GRADUALLY PROPAGATE THROUGH THE
TROUGH BASE INTO NRN/CNTRL TX WITH STRONGEST HEIGHT FALLS DEVELOPING
FROM NM INTO CNTRL TX TONIGHT.

IN THE LOW-LEVELS...LOW PRESSURE OVER CNTRL KS WILL DEVELOP NEWD
ALONG RETREATING WARM FRONT...EVENTUALLY REACHING NRN IL BY THURSDAY
MORNING.  AS THIS OCCURS...SECONDARY CYCLOGENESIS WILL TAKE PLACE
OVER THE OK/TX PNHDLS LATER THIS AFTERNOON IN RESPONSE TO INTENSE
HEIGHT FALLS OCCURRING OVER NM.  THIS LOW WILL DEVELOP GENERALLY EWD
OR ESEWD ACROSS OK OVERNIGHT AS MID-LEVEL TROUGH MOVES EWD INTO TX. 
SURFACE DRYLINE WILL BECOME INCREASINGLY WELL-DEFINED TODAY FROM
INTERSECTION WITH COLD OR STATIONARY FRONT OVER CNTRL KS SWD THROUGH
WRN OK INTO W-CNTRL TX.

...KS/MO/IL...

CLUSTERS OF ELEVATED TSTMS ARE EXPECTED TO BE ONGOING AT THE ONSET
OF THE FORECAST PERIOD OVER PORTIONS OF ERN KS...MO INTO IL WITHIN
ZONE OF ENHANCED WAA AND ISENTROPIC ASCENT OCCURRING ON NOSE OF
45-55 KT SWLY LLJ.  THIS BRANCH OF THE LLJ WILL GRADUALLY MIGRATE
NEWD TODAY IN ADVANCE OF WEAK IMPULSE /NOW OVER THE TX
PNHDL/...MAINTAINING A BAND OF ELEVATED CONVECTION INTO THE SRN
GREAT LAKES.  PLUME OF STEEP MID-LEVEL LAPSE RATES AND RESULTANT
MODERATE ELEVATED INSTABILITY WILL SUPPORT A FEW STRONG TO SEVERE
STORMS CAPABLE OF MAINLY LARGE HAIL.

ADDITIONAL SURFACE-BASED STORM DEVELOPMENT WILL BECOME INCREASINGLY
LIKELY THIS AFTERNOON INVOF SURFACE LOW DEVELOPING NEWD ALONG WARM
FRONT OVER NERN KS INTO NWRN MO.  FORECAST SOUNDINGS FOR THIS AREA
INDICATE A FAVORABLE ENVIRONMENT FOR SEVERE STORMS INCLUDING
SUPERCELLS GIVEN POTENTIAL MODERATE INSTABILITY /MLCAPES OF
1000-1500 J/KG/ AND 50-60 KTS OF DEEP LAYER SHEAR. 
MOREOVER...LOW-LEVEL SHEAR WILL BE LOCALLY AUGMENTED AHEAD OF THIS
SURFACE LOW...SUGGESTING A THREAT OF A FEW TORNADOES IN ADDITION TO
LARGE HAIL WITH THE MOST INTENSE STORMS ROOTED IN THE
BOUNDARY-LAYER.

WITH TIME...EXPECT ADDITIONAL STORMS TO DEVELOP SWD/SWWD ALONG FRONT
TO IT/S INTERSECTION WITH DRYLINE OVER S-CNTRL KS.  HERE
TOO...ENVIRONMENT WILL BE SUPPORTIVE OF ORGANIZED STORMS...INCLUDING
SUPERCELLS WITH THE POTENTIAL FOR LARGE HAIL AND PERHAPS A COUPLE OF
TORNADOES.  UPSCALE GROWTH INTO A MCS OR LARGE STORM CLUSTERS WILL
OCCUR TONIGHT WITH A DAMAGING WIND...LARGE HAIL AND ISOLATED TORNADO
THREAT SPREADING EWD INTO MO.

...OK/TX/AR/LA...

08/00Z REGIONAL SOUNDINGS INDICATED THAT ONLY A MODESTLY MOIST
LOW-LEVEL AIR MASS /I.E. MEAN MIXING RATIOS OF 10-11 G/KG/ EXISTS
FROM THE TX COAST INTO OK GIVEN THE RELATIVELY WARM TEMPERATURES
OBSERVED AT THE BASE OF THE ELEVATED MIXED LAYER.  DESPITE SOME
INCREASE IN LOW-LEVEL MOISTURE /CONTRIBUTING TO MLCAPES OF 1500
J/KG/...THIS CAP WILL LIKELY INHIBIT STORM DEVELOPMENT ALONG DRYLINE
THROUGH MUCH OF THE AFTERNOON.

RAPID CHANGES IN THE VERTICAL STRATIFICATION OF THE THERMODYNAMIC
ENVIRONMENT ARE FORECAST ALONG DRYLINE AFTER 09/00Z OWING TO STRONG
DYNAMIC COOLING/HEIGHT FALLS WHICH WILL AID IN CAP REMOVAL AND
FURTHER STEEPENING OF MID-LEVEL LAPSE RATES.  AS THIS OCCURS...STORM
DEVELOPMENT WILL BECOME INCREASINGLY LIKELY BETWEEN 09/00-03Z ALONG
OR JUST TO THE W OF THE I-35 CORRIDOR IN OK AND N TX.  GIVEN THE
CORRESPONDING INCREASE IN AMBIENT WIND FIELDS...SUPERCELLS CAPABLE
OF LARGE HAIL AND A COUPLE TORNADOES WILL BE POSSIBLE WITH THE
INITIAL STORM DEVELOPMENT.

STORMS SHOULD GRADUALLY MERGE INTO CLUSTERS OR A MCS AS THEY MOVE
EWD ACROSS ERN OK INTO AR AND N-CNTRL AND NERN TX.  POINT FORECAST
SOUNDINGS ACROSS N-CNTRL INTO SERN OK/NERN TX OVERNIGHT INDICATE
VERY STRONG LOW AND DEEP-LAYER SHEAR PROFILES DEVELOPING WITHIN
INSTABILITY AXIS AHEAD OF ANTICIPATED ONGOING TSTMS.  IF STORMS CAN
REMAIN SURFACE-BASED AND SOMEWHAT DISCRETE...A DISTINCT...NOCTURNAL
TORNADO THREAT MAY DEVELOP FROM SERN OK/NERN TX TOWARD THE ARKLATEX
LATE IN THE FORECAST PERIOD.

...SERN CO...

INCREASED LARGE-SCALE FORCING FOR ASCENT COUPLED WITH NELY LOW-LEVEL
WINDS /WEAK OROGRAPHIC FORCING/ WITHIN IMMEDIATE POST-FRONTAL AIR
MASS MAY SUPPORT A FEW STORMS OVER THE AREA THIS AFTERNOON INTO
EVENING.  GIVEN THE PRESENCE OF STEEP LOW TO MID-LEVEL LAPSE RATES
AND MODERATELY STRONG VERTICAL SHEAR...SOME THREAT WILL EXIST FOR
ORGANIZED/ROTATING STORMS CAPABLE OF MARGINALLY SEVERE HAIL AND
LOCALLY GUSTY WINDS.

..MEAD/TAYLOR.. 03/08/2006