SWODY1
SPC AC 151247
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0747 AM CDT MON OCT 15 2007
VALID 151300Z - 161200Z
..THERE IS A SLGT RISK OF SVR TSTMS OVER CNTRL AND NE TX...
..SYNOPSIS...
UPR LOW/TROUGH NOW OVER SW NEB EXPECTED TO MOVE ONLY SLOWLY ENE THIS
PERIOD...IN TANDEM WITH RIDGE TO ITS NORTH. THE SYSTEM SHOULD REACH
NE NEB BY 12Z TUESDAY AND MAY ASSUME A BIT OF A NEGATIVE TILT AS
BROAD/DIFFLUENT E PACIFIC TROUGH OVERSPREADS THE WRN U.S. SFC LOW
WITH NEB TROUGH SHOULD LIFT SLOWLY N ACROSS FAR ERN NEB/WRN IA
TODAY/TONIGHT AS ASSOCIATED OCCLUDED/COLD FRONT DRIFTS E AND FURTHER
WEAKENS.
..CNTRL/NE TX INTO THE ARKLATEX...
SEASONABLY RICH BOUNDARY LYR MOISTURE IS NOW PRESENT OVER MUCH OF
SRN AND ERN TX AHEAD OF WEAKENING COLD ASSOCIATED WITH NEB UPR
TROUGH. WHILE MID-LEVEL LAPSE RATES WILL BE WEAK...MARITIME AIR
MASS WILL CONTRIBUTE TO MODERATE AFTN INSTABILITY...WITH SBCAPE
INCREASING TO AOA 1500 J/KG IN AREAS EXPERIENCING EVEN MODEST SFC
HEATING.
LARGE SCALE FORCING FOR ASCENT WILL BE LIMITED. BUT SATELLITE/VWP
AND MODEL DATA DO SUGGEST THAT CNTRL AND NE TX WILL BE WITHIN
ENTRANCE REGION OF MID/HI LVL JET STREAK NOW CROSSING THE TX BIG
BEND. TSTMS NOW ALONG COLD FRONT IN CNTRL TX MAY REINTENSIFY WITH
HEATING LATER TODAY. ADDITIONAL DEVELOPMENT IS ALSO POSSIBLE
FARTHER E ALONG WEAK N/S WARM FRONT MARKING LEADING EDGE OF MARITIME
AIR IN ERN PART OF THE STATE....AND ALONG W/E OUTFLOW BOUNDARY LEFT
BY OVERNIGHT MCS IN THE ARKLATEX,
COMBINATION OF MOIST...MODERATELY UNSTABLE THERMODYNAMIC PROFILES
WITH WEAK LOW-LEVEL SHEAR AND 40-50 KT OF DEEP SWLY SHEAR MAY
SUPPORT EMBEDDED SUPERCELLS AND/OR SMALL SCALE BOWS WITH DAMAGING
WINDS AND MARGINALLY SEVERE HAIL. THIS THREAT MAY CONTINUE INTO THE
EVENING BEFORE GRADUALLY DIMINISHING LATER TONIGHT.
..FAR ERN NEB INTO WRN/NRN IA...
MID-LEVEL COLD POOL /500 MB TEMPERATURES OF -16 TO -18 C/ WILL EDGE
E/NE ACROSS THE MID/LWR MO VLY THIS AFTN AS DIFFUSE MID LVL DRY SLOT
ROTATES N/NE ACROSS REGION. WEAKNESS OF SFC LOW AND CONFIGURATION
OF EXISTING LOW LVL MOISTURE/WIND FIELDS SUGGEST THAT DAYTIME
HEATING WILL BE LIMITED. BUT EVEN MODEST BOUNDARY LYR WARMING INVOF
RESIDUAL LOW LVL MOISTURE AXIS MAY BE SUFFICIENT TO SUPPORT SCTD
AFTN CONVECTION/POSSIBLE TSTMS ALONG OCCLUDED FRONT AS SBCAPE
INCREASES TO 300-500 J PER KG. A FEW SPOTS OF HAIL MAY OCCUR GIVEN
COOL THERMODYNAMIC PROFILES...BUT POTENTIAL FOR SUSTAINED SVR
ACTIVITY APPEARS MINIMAL.
.CORFIDI/JEWELL.. 10/15/2007
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