[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 152022
SWODY1
SPC AC 152020

DAY 1 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0320 PM CDT SAT APR 15 2006

VALID 152000Z - 161200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF ERN NEB...SW
IA...NW MO AND FAR NE KS...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CNTRL
PLAINS...

CORRECTED TO ADJUST CATEGORICAL AND HAIL LINES

...PLAINS/UPPER MIDWEST...
WATER VAPOR IMAGERY SHOWS A VIGOROUS NEGATIVELY-TILTED UPPER-LEVEL
TROUGH ENTERING THE PLAINS STATES. A DRY SLOT IS ADVANCING QUICKLY
EWD ACROSS KS AND SRN NEB ASSOCIATED WITH A 90 KT MID-LEVEL JET
NOSING INTO CNTRL NEB. STORMS ARE CURRENTLY INITIATING AHEAD OF THE
DRY SLOT IN ERN KS WHERE A CAPPING INVERSION IS WEAKENING.
ADDITIONAL STORMS DEVELOPING IN SCNTRL NEB THIS AFTERNOON SHOULD
EXPAND ESEWD ACROSS SERN NEB INTO FAR NW MO. AS THE TROUGH SHIFTS
NEWD THROUGH EARLY AFTERNOON...A LARGE MCS SHOULD DEVELOP AND MOVE
ENEWD ACROSS ERN NEB...SWRN IA AND FAR NWRN MO.

FORECAST SOUNDINGS ACROSS THE MODERATE RISK AREA FOR LATE THIS
AFTERNOON AND EARLY THIS EVENING SHOW INCREASING INSTABILITY AS A
MOIST AXIS WITH SFC DEWPOINTS NEAR 60 F SHIFT NEWD ACROSS THE
REGION. IN ADDITION...STRONG VERTICAL SHEAR PROFILES EXIST AND
MID-LEVEL LAPSE RATES WILL CONTINUE TO STEEPEN AS THE MID-LEVEL JET
PUNCHES INTO THE REGION. THE INSTABILITY AND SHEAR WILL BE FAVORABLE
FOR SUPERCELLS WITH LARGE HAIL. AS DESTABILIZATION CONTINUES AND
STORM COVERAGE EXPANDS...THE STRONGER SUPERCELLS SHOULD BE CAPABLE
OF VERY LARGE HAIL. IN ADDITION...THE LOW-LEVEL SHEAR PROFILES WILL
BECOME INCREASINGLY FAVORABLE FOR A FEW TORNADIC SUPERCELLS BY EARLY
EVENING AS A 50 TO 60 KT LOW-LEVEL JET STRENGTHENS AND EXPANDS
ACROSS THE MODERATE RISK AREA. AS STORM COVERAGE EXPANDS AND A MCS
MOVES ACROSS SRN IA AND NRN MO INTO FAR NWRN IL THIS EVENING...A FEW
TORNADOES ALONG WITH LARGE HAIL AND WIND DAMAGE WILL CONTINUE TO BE
POSSIBLE. THE SEVERE THREAT SHOULD EVENTUALLY BECOME MARGINAL AS THE
CONVECTIVE COMPLEX MOVES EWD INTO IND AFTER MIDNIGHT WHERE
INSTABILITY WILL BE WEAKER.

...CNTRL APPALACHIANS/ATLANTIC COASTAL PLAINS...
WATER VAPOR IMAGERY CURRENTLY SHOWS A SUBTLE SHORTWAVE TROUGH ACROSS
THE OH VALLEY MOVING INTO THE CNTRL APPALACHIAN MTNS. SCATTERED
THUNDERSTORM DEVELOPMENT SHOULD CONTINUE TO OCCUR AHEAD OF THIS
FEATURE IN THE CNTRL APPALACHIAN MTNS AND ATLANTIC COASTAL PLAINS
THIS AFTERNOON. OBJECTIVE ANALYSIS ACROSS THE REGION SHOW STRONG
VERTICAL SHEAR PROFILES...MODERATE INSTABILITY AND STEEP MID-LEVEL
LAPSE RATES WHICH SHOULD BE FAVORABLE FOR SUPERCELLS WITH A
POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. STORM COVERAGE ALONG WITH
THE SEVERE POTENTIAL SHOULD DECREASE THIS EVENING AS INSTABILITY
WEAKENS AND A SHORTWAVE RIDGE APPROACHES FROM THE WEST.

..BROYLES.. 04/15/2006