DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 290059
SWODY1
SPC AC 290056

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0756 PM CDT SAT APR 28 2007

VALID 290100Z - 291200Z

..THERE IS A SLGT RISK OF SVR TSTMS FROM SERN AZ EWD PARTS OF THE
RIO GRANDE VALLEY...

..SOUTHWEST TO RIO GRANDE VALLEY...
ZONE OF PRONOUNCED DIFFLUENCE ALOFT WITHIN NORTHEAST QUADRANT OF
BAJA UPPER LOW HAS CONTRIBUTED TO A VERY FAVORABLE REGIME FOR DESERT
TSTMS FROM SRN AZ...EWD ACROSS THE RIO GRANDE VALLEY...AND INTO
PARTS OF WEST TX THIS EVENING. LOW LEVEL ISALLOBARIC AND TERRAIN
FORCING HAVE FURTHER AIDED THIS DEVELOPMENT WITH FAIRLY DEEP LAYER
OF ELY UPSLOPE FLOW TRANSPORTING MOISTURE WWD/NWWD...AND SUSTAINING
MLCAPE VALUES IN THE RANGE OF 500-1000 J/KG.

WHILE EFFECTIVE SHEAR IS LIMITED GIVEN RELATIVELY WEAK MID LEVEL
FLOW OF 20-25KT BASED ON VWP AND RAOB DATA...COMBINATION OF
DIRECTIONAL SHEAR IN THE UPDRAFT SOURCE REGION AND POSSIBLE
ORGANIZING INFLUENCES FROM SMALLER-SCALE VORTICITY MAXIMA /MCV/
ROTATING AROUND THE LARGER-SCALE LOW...SHOULD SUSTAIN A FEW CLUSTERS
OF ROBUST MULTICELLULAR STORMS WITH ATTENDANT HAIL/WIND HAZARDS.
REF. MCD 610 FOR ADDITIONAL INFORMATION.

BEYOND ABOUT 03Z...MODEL GUIDANCE...INCLUDING EXPERIMENTAL 3KM
WRF-NMM...INDICATE THAT CONVECTION MAY BEGIN TO CONSOLIDATE INTO A
SMALL MCS ACROSS SRN NM AND THEN DRIFT EAST TOWARD WEST TX BY
MORNING. CONVECTION MAY BE MAINTAINED WELL INTO THE NIGHT BY BOTH
LARGE SCALE DYNAMICS AHEAD OF THE ADVANCING UPPER LOW...AND A
CONTINUATION OF MOIST LOW LEVEL INFLOW. WHILE A SMALL CHANCE OF
SEVERE HAIL/WIND MAY PERSIST INTO EARLY SUNDAY...LOCALLY HEAVY RAIN
MAY ALSO BECOME A PROBLEM.

..OH VALLEY TO CNTRL APPALACHIANS...
ASCENT/MOISTENING AND STEEPENING LAPSE RATES WITH FAST-MOVING SHORT
WAVE TROUGH DIGGING SEWD FROM GREAT LAKES AREA WERE SUSTAINING WEAK
CONVECTION ACROSS OH/NRN KY ATTM. EXPECT THIS ACTIVITY MAY PERSIST
EWD INTO WV NEXT 1-2 HOURS BEFORE CG LIGHTNING ACTIVITY BEGINS TO
SUBSIDE WITH DIURNAL COOLING/STABILIZATION.

.CARBIN.. 04/29/2007

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