DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 120552
SWODY1
SPC AC 120550

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1250 AM CDT THU APR 12 2007

VALID 121200Z - 131200Z

..THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SRN HIGH
PLAINS...

..SYNOPSIS...

UPPER TROUGH OVER THE PACIFIC NW WILL AMPLIFY SEWD THROUGH CA AND
INTO THE SWRN STATES BY THURSDAY EVENING ACCOMPANIED BY A COLD
FRONT. PRIMARY SURFACE LOW WILL CONSOLIDATE OVER THE SWRN STATES IN
RESPONSE TO INCREASING UPPER DIVERGENCE AND ASCENT DOWNSTREAM FROM
THE SEWD ADVANCING SHORTWAVE TROUGH. A WARM FRONT WILL LIKELY
DEVELOP AND EXTEND ESEWD FROM THE LOW THROUGH THE TX PANHANDLE INTO
NWRN TX BY THURSDAY EVENING. A LEAD SHORTWAVE TROUGH MOVING THROUGH
SRN CA AND SWRN NV WILL ADVANCE EAST INTO THE SRN HIGH PLAINS DURING
THE AFTERNOON.

..SRN HIGH PLAINS THROUGH PORTIONS OF THE SRN PLAINS...

RICHER LOW LEVEL MOISTURE WITH MID TO UPPER 60S DEWPOINTS REMAINS
OFF THE SRN TX COAST EARLY THIS MORNING. THE BOUNDARY LAYER IS MUCH
DRYER FARTHER INLAND WITH DEWPOINTS PRIMARILY IN THE 40S OVER CNTRL
TX AND 20S TO 30S FARTHER NW INTO WRN TX. A SSELY LOW LEVEL JET WILL
DEVELOP OVER WRN TX THURSDAY AND STRENGTHEN SIGNIFICANTLY BY
THURSDAY EVENING DOWNSTREAM FROM SURFACE LOW. THIS WILL RESULT IN
THE ADVECTION OF PARTIALLY MODIFIED GULF AIR NWWD THROUGH THE SRN
HIGH PLAINS WITH BOUNDARY LAYER DEWPOINTS PRIMARILY IN THE 40S TO
AROUND 50. DRYLINE WILL LIKELY SET UP ACROSS ERN NM OR WRN TX AS
MOISTURE RETURNS NWWD DURING THE AFTERNOON. THE MODEST LOW LEVEL
MOISTURE RETURN BENEATH STEEP MID LEVEL LAPSE RATES WILL CONTRIBUTE
TO DESTABILIZATION DURING THE AFTERNOON WITH MLCAPE FROM 500 TO 1000
J/KG FROM EXTREME ERN NM THROUGH WRN TX.

FORCING FOR ASCENT ASSOCIATED WITH LEAD SHORTWAVE TROUGH WILL
ADVANCE INTO THE HIGH PLAINS DURING THE AFTERNOON. THIS ALONG WITH
STRONG SURFACE HEATING AND MIXING WITHIN THE BOUNDARY LAYER SHOULD
CONTRIBUTE TO HIGH BASED STORMS FROM ERN NM THROUGH WRN TX. DEEP
LAYER SHEAR AND LOW LEVEL HODOGRAPHS WILL BECOME FAVORABLE FOR
SUPERCELLS BY LATE AFTERNOON INTO THE EVENING AS THE LOW LEVEL JET
STRENGTHENS. HOWEVER...HIGH BASED NATURE OF THE STORMS SUGGESTS
PRIMARY THREATS SHOULD BE LARGE HAIL AND ISOLATED DAMAGING WIND.

OVERNIGHT...RICHER MOISTURE WILL LIKELY RETURN NWD AS THE BOUNDARY
LAYER DECOUPLES AND THE LOW LEVEL JET STRENGTHENS. STRONG ISENTROPIC
LIFT N OF THE WARM FRONT SUGGESTS ADDITIONAL STORMS WILL DEVELOP AND
MAY EVOLVE INTO AN MCS OVERNIGHT. ACTIVITY WILL SHIFT EAST THROUGH
PARTS OF NRN TX...OK AND SRN KS. LARGE HAIL WILL REMAIN
POSSIBLE...ESPECIALLY ON THE SRN AND WRN FLANKS OF THE MCS WHERE
FEED OF HIGHER THETA-E AIR WILL EXIST.

.DIAL/CROSBIE.. 04/12/2007

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