SWODY1
SPC AC 171957
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0257 PM CDT THU MAY 17 2007
VALID 172000Z - 181200Z
..NO SVR TSTM AREAS FORECAST...
..SRN OH/ERN KY/WRN WV/FAR SWRN VA/NERN TN...
ASCENT AHEAD OF MID/UPPER LEVEL SHORT WAVE TROUGH OVER THE OH VALLEY
AND WEAK SURFACE LOW IN ERN KY COMBINED WITH COLD MID LEVEL
TEMPERATURES WILL SUPPORT ADDITIONAL DIURNAL TSTM DEVELOPMENT ACROSS
ERN KY/FAR SRN OH INTO THE WRN FOOTHILLS OF THE CENTRAL
APPALACHIANS. THE COLD MID LEVEL TEMPERATURES WILL BE SUPPORTIVE
FOR A FEW ADDITIONAL HAIL EVENTS APPROACHING OR LOCALLY EXCEEDING
SEVERE LEVELS. STRONG SFC-3 KM CAPE CO-LOCATED WITH STRONG SURFACE
VORTICITY AND AMBIENT VORTICITY WITH MID LEVEL TROUGH SUGGESTS THE
POTENTIAL FOR A FEW FUNNELS AND/OR BRIEF TORNADO.
..SERN AZ/SWRN NM INTO SWRN TX...
AN AXIS OF GULF OF MEXICO MOISTURE REMAINS ENTRENCHED NWWD ACROSS
NRN CHIHUAHUA TO SWRN NM/SERN AZ WITH SURFACE DEWPOINTS GENERALLY IN
THE LOWER TO MID 50S. THIS COMBINED WITH STEEP LAPSE RATES IS
RESULTING IN AN AXIS OF MODERATE INSTABILITY. SATELLITE IMAGERY
INDICATED SLOW MOVING LOW-MID LEVEL LOW LOCATED OVER CENTRAL NM THIS
AFTERNOON. ALTHOUGH LARGE SCALE DOWNWARD VERTICAL MOTION IN THE
WAKE OF THIS LOW MAY TEND TO LIMIT TSTM DEVELOPMENT...SURFACE
HEATING WILL PROMOTE ADDITIONAL TSTMS IN THE HIGHER TERRAIN. DEEP
LAYER SHEAR SHOULD REMAIN THE STRONGEST ALONG SRN PERIPHERY OF NM
LOW WITH OBJECTIVE ANALYSES INDICATING EFFECTIVE BULK SHEAR OF 30-35
KT EXTENDING SWD FROM FAR SRN NM/FAR W TX.
STORMS THAT CAN DEVELOP AND/OR MOVE INTO THIS REGIME OF GREATER
SHEAR AND INSTABILITY FROM FAR SWRN NM TO ALONG THE RIO GRANDE
VALLEY IN SW TX WILL HAVE THE POTENTIAL TO BECOME ORGANIZED AND
PRODUCE STRONG WIND GUSTS AND/OR HAIL. HOWEVER...AT THIS TIME...
OVERALL THREAT IS NOT EXPECTED TO EXCEED THE LOWER SEVERE
PROBABILITIES.
..FOUR CORNERS/CENTRAL ROCKIES TO CENTRAL/NRN HIGH PLAINS...
VISIBLE IMAGERY INDICATED TSTMS HAVE ALREADY DEVELOPED IN THE HIGHER
TERRAIN FROM THE FOUR CORNERS REGION NWD INTO WY.
AN AXIS OF MODERATE INSTABILITY WILL CONTINUE DEVELOPING ACROSS THE
NRN/CENTRAL HIGH PLAINS ALONG ERN EXTENT OF STEEP LAPSE RATE PLUME
AS IT SPREADS EWD ATOP A WEAK MOIST AXIS ALONG THE WRN PLAINS.
25-30 KT SLY LLJ EXTENDING NWD FROM ERN CO/WRN KS TO DAKOTAS AND
BENEATH WNWLY MID LEVEL WINDS WILL SUPPORT EFFECTIVE BULK SHEAR
VALUES FAVORABLE FOR A FEW ORGANIZED STORMS WITH ANY ACTIVITY THAT
MOVES OFF THE HIGHER TERRAIN ONTO THE PLAINS OF ERN WY/ERN CO TO WRN
SD AND NEB PANHANDLE THIS AFTERNOON AND EVENING.
FARTHER W...DESPITE STEEP LAPSE RATES...GENERALLY MARGINAL
INSTABILITY AND WEAK DEEP LAYER SHEAR ARE EXPECTED TO PRECLUDE A
MORE ORGANIZED TSTM POTENTIAL WSWWD TO THE FOUR CORNERS REGION.
HOWEVER...GIVEN INVERTED-V THERMODYNAMIC PROFILES AND STEEP LAPSE
RATES...A FEW STORMS MAY PRODUCE ISOLATED HAIL AND/OR LOCALLY STRONG
WIND GUSTS.
..NRN ROCKIES INTO WRN MT...
DESPITE STEEP LOW-MID LEVEL LAPSE RATES ACROSS THIS REGION...SCANT
LOW LEVEL MOISTURE WILL CONTINUE TO RESULT IN WEAK INSTABILITY AND
TEND TO LIMIT THE DEVELOPMENT OF MORE ROBUST UPDRAFTS. WEAK ASCENT
ALONG SRN EXTENT OF A SHORT WAVE TROUGH MOVING INTO SWRN CANADA THIS
FORECAST PERIOD AND ADDITIONAL SURFACE HEATING SHOULD ALLOW FOR AN
INCREASE IN TSTM DEVELOPMENT ACROSS THE NRN ROCKIES INTO WRN MT.
DESPITE EFFECTIVE BULK SHEAR OF 30-35 KT EXPECTED ACROSS THIS
REGION...WEAK INSTABILITY SHOULD LIMIT THE COVERAGE OF SEVERE
WEATHER AND THUS MAINTAIN LOW SEVERE PROBABILITIES.
.PETERS.. 05/17/2007
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