[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 240600
SWODY1
SPC AC 240559

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT MON APR 24 2006

VALID 241200Z - 251200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF KANSAS AND
OKLAHOMA...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL
PLAINS...SRN PLAINS AND MID-MS VALLEY...

...GREAT PLAINS/MID-MS VALLEY...
AN UPPER-LEVEL TROUGH OVER THE SWRN STATES IS FORECAST TO EJECT
ENEWD ACROSS THE ROCKIES TODAY. A 70 KT MID-LEVEL JET ASSOCIATED
WITH THE TROUGH WILL NOSE INTO THE CNTRL PLAINS THIS AFTERNOON
INCREASING VERTICAL SHEAR PROFILES. THIS COMBINED WITH STRONG
LARGE-SCALE ASCENT AND A VERY UNSTABLE AIRMASS WILL LIKELY RESULT IN
WIDESPREAD SEVERE WEATHER ACROSS THE REGION THIS AFTERNOON AND
TONIGHT.

SEVERAL MESOSCALE CONVECTIVE SYSTEMS SHOULD BE ONGOING AT THE
BEGINNING OF THE PERIOD. MODEL FORECASTS VALID AT 12Z GENERALLY
AGREE KEEPING MOST OF THE CONVECTIVE CLUSTERS ACROSS SRN NEB...NERN
KS AND WRN MO. THE LACK OF CONVECTION ALONG WITH A CAPPING INVERSION
SHOULD KEEP THE AIRMASS ACROSS THE MODERATE RISK AREA UNDISTURBED
THROUGH MIDDAY. CONTINUED MOISTURE ADVECTION DURING THE DAY SHOULD
BRING SFC DEWPOINTS IN THE MID 60S F AS FAR NORTH AS CNTRL KS. THIS
SHOULD RESULT IN MODERATE TO STRONG INSTABILITY BY AFTERNOON ACROSS
THE WARM SECTOR. AS A COLD FRONT APPROACHES CNTRL KS DURING THE
AFTERNOON...INCREASING LOW-LEVEL CONVERGENCE AND THE WEAKENING CAP
SHOULD RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT WITH STORMS
DEVELOPING SWD TOWARD THE OK STATELINE. VERTICAL SHEAR SHOULD
GRADUALLY INCREASE DURING THE DAY AS A MID-LEVEL JET PUNCHES INTO
THE REGION. FORECAST SOUNDINGS AT 21Z ACROSS THE MODERATE RISK AREA
SHOW 0-6 KM SHEAR VALUES OF 40 TO 50 KT WHICH COMBINED WITH STEEP
LAPSE RATES AND STRONG INSTABILITY SHOULD BE FAVORABLE FOR
SUPERCELLS WITH LARGE HAIL. THE MORE INTENSE SUPERCELLS WILL ALSO
HAVE A POTENTIAL FOR VERY LARGE HAIL AND TORNADOES...ESPECIALLY AS
THE LOW-LEVEL JET EXPANDS NWD ACROSS THE REGION IN THE LATE
AFTERNOON AND EARLY EVENING. A LINEAR MCS SHOULD GRADUALLY DEVELOP
AS SUGGESTED BY THE WRF-NMM/NAM AND GFS WITH THE WIND DAMAGE
POTENTIAL BECOMING ENHANCED DURING THE EVENING HOURS ACROSS THE
OZARK PLATEAU. ALTHOUGH THE MCS MAY CONTINUE WITH THE MCS INTO SRN
MO AND NRN AR AFTER MIDNIGHT...ANY SEVERE THREAT SHOULD GRADUALLY
DECREASE DUE TO WEAKENING INSTABILITY.

FURTHER SOUTH ACROSS OK AND NRN/CNTRL TX STRONG INSTABILITY WILL
LIKELY BE IN PLACE WITH SFC DEWPOINTS IN THE MID TO UPPER 60S F.
FORECAST SOUNDINGS SHOW A CAPPING INVERSION REMAINING IN PLACE
THROUGH MUCH OF THE AFTERNOON AHEAD OF A DRYLINE EXTENDING SSWWD
FROM NEAR WICHITA FALLS INTO THE TX HILL COUNTRY. AS LOW-LEVEL
CONVERGENCE INCREASES EAST OF THE DRYLINE...ISOLATED THUNDERSTORMS
SHOULD INITIATE AND MOVE EWD ACROSS THE I-35 CORRIDOR. STRONG
INSTABILITY...MODERATE VERTICAL SHEAR AND STEEP LAPSE RATES SHOULD
BE SUFFICIENT FOR SUPERCELLS WITH LARGE HAIL AND ISOLATED WIND
DAMAGE. A FEW TORNADOES WILL BE POSSIBLE WITH THE STRONGER
SUPERCELLS IN NCNTRL AND NERN OK WHERE THE LOW-LEVEL JET IS FORECAST
TO STRENGTHEN IN THE EARLY EVENING. DECREASING INSTABILITY AND A
STRENGTHENING CAPPING INVERSION SHOULD RESULT IN A GRADUAL DECREASE
OF THE SEVERE THREAT BY LATE EVENING.

..BROYLES.. 04/24/2006