SWODY1
SPC AC 291950
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0250 PM CDT MON JUN 29 2009
VALID 292000Z - 301200Z
...NO SVR TSTM AREAS FORECAST...
...SOUTHEAST...
CONVECTION HAS DEVELOPED ALONG WEAK BOUNDARIES ACROSS PARTS OF
GA/AL/FL...AND OVER SOUTHERN LA/MS. WEAK FLOW ALOFT APPEARS TO BE
LIMITING CONVECTIVE ORGANIZATION AND LONGEVITY OF STRONGER UPDRAFTS.
NEVERTHELESS...STRONG INSTABILITY AND HIGH MOISTURE CONTENT OF
AIRMASS WILL CONTINUE TO PROMOTE WATER LOADING OF DOWNDRAFTS AND THE
RISK OF ISOLATED WET MICROBURSTS THROUGH THE AFTERNOON.
...TX...
AXIS OF CONVECTION EXTENDS WESTWARD INTO CENTRAL TX...WHERE
TEMPERATURES NEAR 100F HAVE RESULTED IN STEEP LOW LEVEL LAPSE RATES
AND MUCAPE OVER 3000 J/KG. A FEW INTENSE CELLS WILL REMAIN POSSIBLE
OVER THIS REGION THROUGH THE AFTERNOON WITH LOCALLY GUSTY WINDS THE
MAIN THREAT.
...GREAT LAKES...
VISIBLE SATELLITE AND RADAR IMAGERY SHOW SCATTERED SHOWERS ACROSS
PARTS OF LOWER MI/OH/NY. HOWEVER...SHOWERS THUS FAR HAVE REMAINED
SHALLOW WITH LITTLE OR NO LIGHTNING ACTIVITY INDICATED. WILL
MAINTAIN LOW PROBS FOR HAIL THROUGH THE AFTERNOON IN CASE ISOLATED
CELLS CAN BECOME MORE INTENSE.
...HIGH PLAINS...
FULL SUNSHINE ACROSS THE HIGH PLAINS HAS CONTRIBUTED TO AN AXIS OF
MODERATE INSTABILITY FROM THE WESTERN DAKOTAS INTO EASTERN CO.
WATER VAPOR IMAGERY HINTS AT A WEAK MID LEVEL SHORTWAVE TROUGH
MOVING ACROSS SOUTHEAST MT/NORTHEAST WY WHICH MAY HELP TO INITIATE
ISOLATED STORMS NEAR THE BLACK HILLS THIS AFTERNOON. OTHER STORMS
HAVE BEGUN TO FORM OVER THE FOOTHILLS OF CENTRAL CO. ALL OF THESE
STORMS MAY SPREAD EASTWARD AND MAINTAIN SOME INTENSITY THROUGH THE
AFTERNOON. ISOLATED HIGH-BASED SEVERE STORMS CAPABLE OF HAIL AND
DAMAGING WINDS ARE POSSIBLE. HOWEVER...AREAL COVERAGE IS EXPECTED
TO BE QUITE LOW.
..HART.. 06/29/2009
.PREV DISCUSSION... /ISSUED 1124 AM CDT MON JUN 29 2009/
...ERN GREAT LAKES INTO PORTIONS OF THE NORTHEAST...
RESIDUAL LOW LEVEL MOISTURE IN WAKE OF MAIN SURFACE COLD FRONT WILL
SUPPORT MARGINAL INSTABILITY THIS AFTERNOON WITH MODEST HEATING
UNDER BROAD CYCLONIC FLOW ALOFT. CUMULUS IS ALREADY EXPANDING LATE
THIS MORNING AND SHOULD EVOLVE INTO SCATTERED LOW TOPPED
THUNDERSTORMS THROUGH THE AFTERNOON. FLOW ALOFT WILL BE QUITE
STRONG FOR THIS TIME OF YEAR AND SHOULD SUPPORT SUFFICIENT SHEAR
WITHIN THE CLOUD LAYER FOR SOME MULTICELLULAR ORGANIZATION AND
ISOLATED HAIL/WIND NEAR SEVERE LEVELS. ACTIVITY WILL DIMINISH
QUICKLY AFTER DARK.
...TX ACROSS THE CENTRAL GULF COAST AND INTO THE SOUTHEAST...
STALLED SURFACE FRONT WILL MAINTAIN FOCUS FOR DEEP MOIST CONVECTION
THROUGH THE PERIOD...ALTHOUGH OVERALL SEVERITY WILL BE LIMITED BY
WARM AIR ALOFT AND WEAK FLOW THROUGH THE TROPOSPHERE.
HOWEVER...ISOLATED DOWNBURSTS MAY PRODUCE DAMAGE WITH THE STRONGER
CORES GIVEN THE VERY MOIST/UNSTABLE WARM SECTOR. A GREATER
POTENTIAL FOR SOME STORM-SCALE ORGANIZATION SHOULD INTO PORTIONS OF
NRN FL WHERE MODEST LOW LEVEL WLY FLOW COULD SUPPORT LINES/CLUSTERS
OF STRONGER STORMS THROUGH THE EVENING.
...CENTRAL INTO THE NRN HIGH PLAINS...
WEAK LEE TROUGH SHOULD FOCUS SCATTERED THUNDERSTORMS THIS
AFTERNOON/EVENING FROM ERN CO INTO WRN SD/FAR ERN WY/SERN MT AS
SURFACE DEW POINTS REMAIN AOA 50F AND WILL SUPPORT MODERATE
INSTABILITY. ISOLATED HAIL/WIND NEAR SEVERE LEVELS REMAINS POSSIBLE
WITH THE STRONGER STORMS. ADDITIONAL CLUSTER OF STORMS SHOULD
DEVELOP OVER THE HIGHER TERRAIN AND INVOF SURFACE FRONT STALLING E-W
ACROSS S-CENTRAL MT THIS AFTERNOON AS WEAK IMPULSE MOVE ACROSS THE
NRN ROCKIES. PW/S REMAIN QUITE DRY...BUT A FEW HIGH-BASED STORMS
WILL REMAIN CAPABLE OF PRODUCING STRONG/DAMAGING WINDS AND POSSIBLY
HAIL INTO THE EVENING.
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