RSS Mesoscale Discussions from Storm Prediction Center
WW 643 SEVERE TSTM IL MO 022145Z - 030500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 643
NWS STORM PREDICTION CENTER NORMAN OK
445 PM CDT THU SEP 2 2010
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
CENTRAL AND SOUTHERN ILLINOIS
CENTRAL AND SOUTHERN MISSOURI
EFFECTIVE THIS THURSDAY AFTERNOON FROM 445 PM UNTIL MIDNIGHT CDT.
HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTHWEST
OF MONETT MISSOURI TO 25 MILES SOUTH OF DANVILLE ILLINOIS. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU3).
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
OTHER WATCH INFORMATION...CONTINUE...WW 642...
DISCUSSION...THUNDERSTORMS ARE SLOWLY INCREASING IN COVERAGE AND
INTENSITY ALONG/AHEAD OF A COLD FRONT MOVING SEWD INTO LOWER MO AND
MIDDLE MS VALLEYS. PRE-FRONTAL AIR MASS IS WARM WITH SURFACE
TEMPERATURES IN THE MID/UPPER 80S...AND DEW POINTS IN THE LOW 70S
ARE CONTRIBUTING TO MLCAPE OF 1500-2500 J/KG. WINDS ALOFT AND DEEP
LAYER SHEAR IS EXPECTED TO INCREASE /ESPECIALLY OVER CNTRL PART SOF
MO AND IL/ AS UPSTREAM UPPER TROUGH MOVES TOWARD THE MS VALLEY
TONIGHT. DAMAGING WIND GUSTS AND HAIL WILL BE THE PRIMARY SEVERE
THREATS.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 26025.
...WEISS
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WW 642 SEVERE TSTM KS OK TX 022030Z - 030300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 642
NWS STORM PREDICTION CENTER NORMAN OK
330 PM CDT THU SEP 2 2010
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
LARGE PART OF SOUTHEAST KANSAS
LARGE PART OF NORTHERN AND WESTERN OKLAHOMA
PARTS OF NORTHWEST TEXAS
EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 330 PM UNTIL
1000 PM CDT.
HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTH
SOUTHWEST OF CHILDRESS TEXAS TO 45 MILES EAST NORTHEAST OF
CHANUTE KANSAS. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
DISCUSSION...STRONG COLD FRONT WILL INITIATE THUNDERSTORMS AS IT
ENCOUNTERS AN INCREASINGLY UNSTABLE AND WEAKLY CAPPED AIR MASS.
WITH DCAPES TO 1500 J/KG AND MLCAPES AOA 2000 J/KG...DAMAGING WINDS
WILL BECOME INCREASING THREAT AS STORMS DEVELOP ALONG AND FRONT AS
IT CONTINUES SWD THRU THE WATCH.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 30020.
...HALES
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WW 0643 Status Reports
STATUS FOR WATCH 0643 HAS NOT BEEN ISSUED YET
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WW 0642 Status Reports
STATUS REPORT ON WW 642
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..STOPPKOTTE..09/02/10
ATTN...WFO...ICT...TOP...SGF...EAX...OUN...TSA...LUB...AMA...
STATUS REPORT FOR WS 642
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
KSC001-003-011-015-019-021-031-035-037-049-059-073-091-099-107-
111-121-125-133-139-205-207-022340-
KS
. KANSAS COUNTIES INCLUDED ARE
ALLEN ANDERSON BOURBON
BUTLER CHAUTAUQUA CHEROKEE
COFFEY COWLEY CRAWFORD
ELK FRANKLIN GREENWOOD
JOHNSON LABETTE LINN
LYON MIAMI MONTGOMERY
NEOSHO OSAGE WILSON
WOODSON
MOC013-037-095-022340-
MO
. MISSOURI COUNTIES INCLUDED ARE
BATES CASS JACKSON
OKC009-011-015-017-027-031-033-035-037-039-043-047-051-053-055-
057-065-071-073-075-081-083-087-093-103-105-109-113-115-117-119-
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No Mesoscale Discussions are in effect as of Thu Sep 2 22:31:02 UTC 2010.
SPC 2000Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0245 PM CDT THU SEP 02 2010
VALID 022000Z - 031200Z
...THERE IS A SLGT RISK OF SVR TSTMS FROM WI TO NWRN TX...
LITTLE CHANGE TO EARLIER FORECAST REGARDING THE OVERALL SEVERE
THREAT ALONG ADVANCING COLD FRONT. LATEST DIAGNOSTIC DATA SUGGEST
SFC WIND SHIFT IS SURGING SWD ACROSS KS-NWRN OK-NRN TX PANHANDLE AND
WILL SOON UNDERCUT MORE MOIST BOUNDARY LAYER IN PLACE OVER THE
SRN/CNTRL PLAINS. ATTM IT APPEARS CONSIDERABLE FRONTAL ASCENT IS
NEEDED FOR TSTM DEVELOPMENT...PER ELEVATED ACTIVITY LAGGING COLD
FRONT OVER CNTRL KS. WITH TIME CINH WILL BE REMOVED OVER SERN KS
INTO NWRN TX...EVEN SO THERE IS SOME INDICATION THAT UPDRAFTS MAY BE
SLIGHTLY ELEVATED...AT LEAST INITIALLY. LATEST VIS IMAGERY SUPPORTS
THE POST-FRONTAL MOIST ASCENT WITH AN EXPANSIVE AREA OF CLOUDINESS
EXTENDING ACROSS KS INTO EXTREME NWRN OK. UPDRAFTS SHOULD GRADUALLY
INITIATE WITHIN THIS BAND OVER THE NEXT FEW HOURS.
FARTHER NORTH INTO THE UPPER MS VALLEY...SCATTERED THUNDERSTORMS ARE
EVOLVING ALONG THE WIND SHIFT ACROSS SERN MN-NERN IA-SWRN WI. THIS
ACTIVITY IS EVOLVING WITHIN AN ENVIRONMENT OF STRONG DEEP LAYER
SHEAR BUT ONLY MODEST INSTABILITY. GIVEN THE STRONG FORCING NOTED
WITH THIS ACTIVITY THESE STORMS SHOULD CONTINUE TO EXPAND IN AREAL
COVERAGE AS THEY SPREAD ACROSS THE SRN HALF OF WI INTO NRN IL.
LARGE HAIL AND DAMAGING WINDS ARE EXPECTED.
..DARROW.. 09/02/2010
.PREV DISCUSSION... /ISSUED 1059 AM CDT THU SEP 02 2010/
...SYNOPSIS...
VIGOROUS TROUGH NRN PLAINS WILL CONTINUE TO INTENSIFY MOVING TO
UPPER GREAT LAKES/OH VALLEY TONIGHT. SURFACE LOW ASSOCIATED WITH
THE TROUGH WILL DEEPEN AS IT MOVES EWD JUST TO THE N OF LS WHILE
STRONG/FALL LIKE COLD FRONT CONTINUES TO SWEEP E AND SE ACROSS THE
MS VALLEY TO THE SRN PLAINS BY THIS EVENING.
INTENSE HURRICANE EARL ON TRACK TO MOVE NWD E OF THE NC COAST
TONIGHT KEEPING THE SECTOR MOST FAVORABLE FOR ROTATING UPDRAFTS WELL
OFFSHORE.
...SRN PLAIN S TO UPPER GREAT LAKES...
PRIMARY MECHANISM FOR ANY ORGANIZED THUNDERSTORMS/SEVERE POTENTIAL
WILL BE THE LOW LEVEL FORCING OF THE COLD FRONT. IN RESPONSE TO SFC
HEATING/LOW LVL DESTABILIZATION THIS AFTERNOON...EXPECT SCTD TO
NUMEROUS AFTN TSTMS FCST TO FORM INVOF COLD FRONT AND RESIDUAL
OUTFLOW BOUNDARIES FROM WI SW ACROSS MO INTO SE KS AND OK. THE
PREDOMINANT CONVECTIVE MODE SHOULD FAIRLY QUICKLY BECOME
QUASI-LINEAR. THE MAIN THREAT WITH THIS ACTIVITY
SHOULD BE DMGG WIND...WITH ISOLD TO WIDELY SCTD SVR HAIL ALSO
POSSIBLE...MAINLY WITH ANY MORE DISCRETE STORMS.
THE STRONGEST MID/UPR LVL WINDS AND SHEAR WILL EXIST JUST AHEAD OF
THE UPPER TROUGH FROM THE MID MS VLY NEWD...WHERE 40-50 KT 500 MB
FLOW IS EXPECTED. SOME SFC HEATING AND DEW POINTS INTO THE UPR 60S
TO NEAR 70F SHOULD OFFSET MODEST MID LVL LAPSE RATES TO YIELD MLCAPE
OF 1500-2500 J/KG. FARTHER SW...COMBINATION OF GREATER CAPE AND
STEEPER LOW LVL LAPSE RATES MAY SUPPORT UPSCALE DEVELOPMENT INTO A
SIZABLE FORWARD-PROPAGATING MCS BY LATE AFTN/EARLY EVE IN OK...AND
NW TX. DESPITE CONSIDERABLY WEAKER DEEP FLOW/SHEAR...THIS ACTIVITY
MAY SUPPORT MORE WIDESPREAD DAMAGING WIND GUSTS GIVEN DEEPLY MIXED
BOUNDARY AND AMPLE MOISTURE/INSTABILITY AVAILABILITY.
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SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0136 PM CDT THU SEP 02 2010
VALID 031200Z - 041200Z
...NO CRITICAL AREAS...
NO CHANGES. DRY TSTM THREAT ACROSS THE CASCADES OF SRN WA AND ORE
APPEARS APPRECIABLY LOW AND WILL MAINTAIN NO AREAS CATEGORY
THROUGHOUT THE CONUS FOR FRIDAY.
..SMITH.. 09/02/2010
.PREV DISCUSSION... /ISSUED 0329 AM CDT THU SEP 02 2010/
...SYNOPSIS...
A STRONG UPPER TROUGH WILL PROGRESS EWD INTO THE UPPER GREAT LAKES
REGION...WHILE AN UPPER RIDGE BECOMES ESTABLISHED OVER THE DESERT
SOUTHWEST. A COLD FRONT WILL PROGRESS S/WWD ACROSS TX AND INTO
NM/AZ...AND AID IN THE RETURN OF LOW-LEVEL MOISTURE TO PORTIONS OF
THE DESERT SOUTHWEST. A SHORTWAVE UPPER TROUGH WILL APPROACH THE PAC
NW COAST...AND RESULT IN ISOLD-SCT THUNDERSTORMS OVER THE CASCADES
OF WA/OR.
...CASCADES OF OR/SRN WA...
WEAK MID-LEVEL INSTABILITY WILL DEVELOP AHEAD OF AN APPROACHING
SHORTWAVE UPPER TROUGH. STRONG DAYTIME HEATING SHOULD RESULT IN
DIURNALLY DRIVEN ISOLATED TO WIDELY SCATTERED THUNDERSTORMS OVER THE
CASCADES OF OR AND SRN WA. SOME OF THESE THUNDERSTORMS MAY PRODUCE
LITTLE TO NO RAINFALL...AS MID-LEVEL FLOW INCREASES AND THE
SUB-CLOUD LAYER REMAINS HOT/DRY. MARGINAL FUEL CONDITIONS DUE TO
RECENT RAINFALL OVER THE REGION COMBINED WITH LIMITED AREAL
THUNDERSTORM COVERAGE WILL PRECLUDE A MORE SIGNIFICANT THREAT.
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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SPC Day 3-8 Fire Weather Outlook
DAY 3-8 FIRE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0209 PM CDT THU SEP 02 2010
VALID 041200Z - 101200Z
A COLD FRONT WILL SWEEP EWD OFF THE E COAST SATURDAY USHERING IN A
MUCH DRIER AIR MASS THIS WEEKEND OVER MUCH OF THE SERN U.S. AND MID
ATLANTIC STATES. OVER THE VA/CAROLINA PIEDMONT....MODERATE WLY
WINDS WITHIN A WARM AIR MASS WILL LIKELY RESULT IN LOW RH VALUES
SURROUNDING PEAK HEATING. FARTHER W...AN UPPER TROUGH WILL MOVE
INTO THE PACIFIC NW WITH SOME POTENTIAL FOR MODERATELY STRONG WINDS
AND ANTECEDENT LOW RH IN A CONFINED AREA ACROSS PARTS OF NRN NV AND
SRN ID. BY SUNDAY /D4/...A MUCH LARGER AREA OF POTENTIALLY CRITICAL
CONDITIONS SHOULD ENCOMPASS PARTS OF THE GREAT BASIN AND N-CNTRL
HIGH PLAINS AND PERHAPS AS FAR S AS THE LOWER CO RIVER VALLEY.
ANOTHER AREA OF CONCERN MAY INCLUDE THE SACRAMENTO VALLEY WHERE THE
LATEST MODELS SHOW INCREASING NLY BOUNDARY LAYER FLOW WITHIN A
WARM/DRY AIR MASS. THE INITIAL UPPER TROUGH IMPACTING THE WRN
STATES OVER THE WEEKEND WILL LIKELY EJECT EWD INTO THE NRN PLAINS AS
AN UPSTREAM DISTURBANCE MOVES SWD ALONG THE PACIFIC COAST. MODEL
GUIDANCE HAS SHOWN CONSISTENCY IN PROJECTING THIS FEATURE OVER THE
NRN CA COAST BY MID-WEEK NEXT WEEK AND MAY RESULT IN INCREASED
POTENTIAL FOR STRONG WINDS/LOW RH ACROSS PORTIONS OF THE DESERT SW
EXTENDING NEWD INTO THE SRN HALF OF THE GREAT BASIN.
..SMITH.. 09/02/2010
...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT...
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