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Aug 24, 2007 2000 UTC Day 1 Convective Outlook |
Updated: Fri Aug 24 20:04:16 UTC 2007 |
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006). |
Public Severe Weather Outlook |
The SPC is forecasting ...severe thunderstorms expected over parts of the middle mississippi river valley into the lower great later today and tonight....
Please read the latest public
statement about this event.
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Categorical Graphic |
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Probabilistic Tornado Graphic |
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Probabilistic Damaging Wind Graphic |
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Probabilistic Large Hail Graphic |
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SPC AC 241959
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0259 PM CDT FRI AUG 24 2007
VALID 242000Z - 251200Z
...THERE IS A MDT RISK OF SVR TSTMS PORTIONS SRN LOWER
MI...INDIANA...ILLINOIS...EXTREME EAST-CENTRAL MISSOURI...
...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM LOWER MI TO
PORTIONS NERN NM/SERN CO...
...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL HIGH PLAINS...
...SYNOPSIS...
UPPER AIR PATTERN AWAY FROM NRN STREAM IS CHARACTERIZED BY RIDGING
AND WEAK FLOW ALOFT FROM SERN CONUS WWD ACROSS TX THEN WNWWD OVER
CENTRAL/SRN CA. MOST SIGNIFICANT NRN STREAM FEATURE IS TROUGH
INITIALLY OVER CENTRAL/NRN HIGH PLAINS -- COMPOSED OF PHASED
SHORTWAVES NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER BLACK HILLS
REGION...ERN CO/WRN KS...AND ERN MN/W TX. COMBINED TROUGH IS FCST
TO MOVE EWD ACROSS CENTRAL CONUS TOWARD MS VALLEY THROUGH REMAINDER
PERIOD.
MEANWHILE...AT SFC...WAVY FRONTAL ZONE IS ANALYZED FROM NRN LOWER MI
SWWD ACROSS NWRN MO TO VICINITY ERN PORTION CO/NM BORDER. THIS
FRONT SHOULD SAG SWD ACROSS S-CENTRAL PLAINS...WHILE MOVING SEWD-EWD
10-15 KT OVER UPPER GREAT LAKES AND MID MS VALLEY REGIONS.
AGGREGATE OF SEVERAL MCS OUTFLOWS IS EVIDENT IN SFC ANALYSIS AND VIS
IMAGERY AHEAD OF AND LARGELY PARALLEL TO SYNOPTIC FRONT...FROM SWRN
LOWER MI SWWD ACROSS CENTRAL IL...SWRN MO...SWRN OK.
...NRN OK TO GREAT LAKES...
SCATTERED TSTMS IN CLUSTERS ARE EXPECTED TO INCREASE IN COVERAGE AND
INTENSITY THROUGH REMAINDER AFTERNOON HOURS...RESULT BEING ONE OR
TWO COMPLEXES WITH POTENTIAL FOR CONCENTRATION OF DAMAGING GUST
REPORTS. RELATIVELY DISCRETE TSTMS ALSO MAY EXHIBIT SUPERCELL
CHARACTERISTICS AND POSE RISK OF LARGE HAIL.
REF WW 647 AND RELATED MESOSCALE DISCUSSIONS FOR NOWCAST GUIDANCE.
RELATIVE CONCENTRATION OF CONVECTIVE WIND PROBABILITIES EXISTS
ACROSS CATEGORICAL MDT RISK AREA...COVERING TERRITORY NEAR AND
DOWNSTREAM FROM ONGOING MO ACTIVITY. BOUNDARY LAYER AIR MASS FROM
SRN MO NEWD ACROSS LOWER MI HAS BEEN EXPERIENCING STG DIABATIC
HEATING/MIXING FOR SEVERAL HOURS...COINCIDENT WITH PRESENCE OF SFC
DEW POINTS COMMONLY LOW-MID 70S F. ASSOCIATED HIGH THETAE AIR MASS
LIES BENEATH BELT OF 40-50 KT 500 MB WINDS EVIDENT IN
PROFILER/VWP/RAOB DATA. DEEP-LAYER SHEAR IS EXPECTED TO WEAKEN
GRADUALLY WITH SWWD EXTENT FROM MO...CONTRIBUTING TO CORRESPONDING
REDUCTION IN ORGANIZED SVR PROBABILITIES.
...CENTRAL HIGH PLAINS...
CLEARING OF MORNING STRATIFORM CLOUD DECK HAS LED TO SUBSTANTIAL
HEATING/DESTABILIZATION OF BOUNDARY LAYER. SFC MESOANALYSIS SHOWS
MOIST AXIS CURVING FROM S-CENTRAL SD SWWD THROUGH NEB
PANHANDLE...THEN SEWD OVER NERN CO AND KS...CHARACTERIZED BY SFC DEW
POINTS GENERALLY 50S F. VEERING/STRENGTHENING OF FLOW WITH HEIGHT
WILL CONTRIBUTE TO EFFECTIVE SHEAR 40-50 KT IN SUPPORT OF LATE
AFTERNOON THROUGH EARLY EVENING SUPERCELL POTENTIAL...WITH LARGE
HAIL LIKELY AND ISOLATED DAMAGING GUSTS POSSIBLE.
...SERN CONUS...
SWATH OF WIDELY SCATTERED TO SCATTERED TSTMS WILL CONTINUE FOR A FEW
MORE HOURS FROM ERN MOUNTAINS/PIEDMONT OF VA SWWD ACROSS MUCH OF AL
AND COASTAL PLAIN FROM FL PANHANDLE TO MS. BOUNDARY INTERACTIONS
MAY ENHANCE CONVERGENCE AND CONTRIBUTE TO MORE INTENSE UPDRAFTS
LOCALLY. ORGANIZED SVR POTENTIAL IS LIMITED BY WEAKNESS OF
LOW-MIDLEVEL WINDS AND RESULTANT LACK OF SHEAR...HOWEVER STRONG
HEATING AND RICH BOUNDARY LAYER MOISTURE WILL CONTRIBUTE TO
POTENTIAL FOR STG/DAMAGING GUSTS IN MOST INTENSE PULSE/MULTICELL
CORES.
..EDWARDS.. 08/24/2007
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z
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