[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 062011
SWODY1
SPC AC 062009

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0309 PM CDT THU APR 06 2006

VALID 062000Z - 071200Z

...THERE IS A HIGH RISK OF SVR TSTMS ACROSS PARTS OF FAR SE
NEB...ERN KS...ERN OK...WRN MO AND WRN AR...

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SW IA...ERN
NEB...KS...ERN OK...WRN MO AND AR...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE PLAINS AND
MS RIVER VALLEY...

...CNTRL AND SRN PLAINS/OZARKS...
WATER VAPOR IMAGERY CURRENTLY SHOWS A VIGOROUS UPPER-LOW/TROUGH OVER
THE HIGH PLAINS WITH A DRY SLOT ADVANCING EWD ACROSS ERN KS AND
CNTRL OK. A 90 KT MID-LEVEL JET IS CURRENTLY EJECTING NEWD OUT OF
THE BASE OF THE TROUGH SPREADING STRONG DIVERGENCE ACROSS THE CNTRL
AND SRN PLAINS. THE STRONG LIFT COMBINED WITH AN AXIS OF MODERATE
INSTABILITY AND WEAKENING CAP IS RESULTING IN RAPID STORM INITIATION
FROM CNTRL KS EXTENDING SSEWD ACROSS ECNTRL OK. REGIONAL PROFILERS
CURRENTLY SHOW STRONG VERTICAL SHEAR PROFILES WHICH ARE BEING
ENHANCED BY THE EJECTING MID-LEVEL JET. IN ADDITION...MID-LEVEL
LAPSE RATES ARE STEEPENING AS THE TROUGH APPROACHES FROM THE WEST.
AS A RESULT...THE ENVIRONMENT APPEARS VERY FAVORABLE FOR SUPERCELLS
WITH LARGE HAIL. VERY LARGE HAIL WILL BE POSSIBLE WITH THE STRONGER
SUPERCELLS. AS THE STORMS TRACK NEWD INTO INCREASING LOW-LEVEL FLOW
AND GREATER INSTABILITY...THE TORNADO THREAT WILL INCREASE. THE BEST
POTENTIAL FOR STRONG TORNADOES APPEARS TO EXIST OVER NE OK...NW
AR...ERN KS AND FAR WRN MO WHERE THE LOW-LEVEL SHEAR PROFILES ARE
BEING ENHANCED BY A STRONG LOW-LEVEL JET. AS THE TROUGH PASSES BY
LATE THIS EVENING...STORMS SHOULD ALSO DEVELOP IN FAR NE TX...SE OK
AND SW AR BUT STORM COVERAGE SHOULD BE LESS DUE TO WEAKER
LARGE-SCALE ASCENT IN THAT AREA.

AS THE DRY SLOT SHIFTS EWD ACROSS THE REGION...STORMS WILL GRADUALLY
MOVE EWD ACROSS MO AND AR. ALTHOUGH THE SEVERE THREAT SHOULD
CONTINUE THROUGH MUCH OF THE NIGHT DUE TO THE VERY STRONG VERTICAL
SHEAR AND FOCUSED LARGE-SCALE ASCENT...DECREASING INSTABILITY SHOULD
ALLOW THE THREAT TO BECOME MARGINAL BY LATE TONIGHT.

...NRN AND CNTRL PLAINS/UPPER MIDWEST...
STORMS ARE CURRENTLY INITIATING ACROSS FAR NRN KS ALONG THE LEADING
EDGE OF ASCENT AHEAD OF AN APPROACHING UPPER-LEVEL TROUGH.
ADDITIONAL STORMS WILL INITIATE ACROSS SRN NEB WITH STORM COVERAGE
INCREASING LATE THIS AFTERNOON. SFC ANALYSIS CURRENTLY SHOWS SFC
DEWPOINTS IN THE 50S F ACROSS NE KS...ERN NEB AND WRN IA WITH
MODERATE INSTABILITY EXTENDING AS FAR NORTH AS SERN SD. AS THE
TROUGH APPROACHES LATE THIS AFTERNOON...VERTICAL SHEAR WILL CONTINUE
TO INCREASE AND LAPSE RATES WILL STEEPEN FURTHER WHICH COMBINED WITH
THE INSTABILITY WILL BE VERY FAVORABLE FOR SUPERCELLS WITH LARGE
HAIL. WIND DAMAGE WILL ALSO BE LIKELY WITH THE STRONGER SUPERCELLS
AND SHOULD BE ENHANCED SOMEWHAT BY THE LARGE SFC TEMP-DEWPOINT
SPREADS EXCEEDING 30 DEGREES F IN SOME PLACES. A FEW TORNADOES WILL
ALSO BE POSSIBLE AS THE STORMS BECOME AFFECTED BY A STRENGTHENING
LOW-LEVEL JET EARLY THIS EVENING. THE MODELS DEVELOP A LARGE MCS
THIS EVENING ACROSS SD...ERN NEB...SRN MN AND IA WHICH SEEMS
REASONABLE CONSIDERING THE AMOUNT OF LARGE-SCALE ASCENT MOVING EWD
AHEAD OF THE TROUGH. THE STORMS SHOULD MOVE AND DEVELOP NEWD INTO
THE UPPER MIDWEST AFTER MIDNIGHT BUT THE SEVERE THREAT SHOULD
GRADUALLY BECOME MARGINAL DUE TO WEAKENING INSTABILITY.

..BROYLES.. 04/06/2006