MESOSCALE DISCUSSION NWS STORM PREDICTION CENTER

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   MESOSCALE DISCUSSION 1838
   NWS STORM PREDICTION CENTER NORMAN OK
   0310 PM CDT SAT JUL 23 2005
   
   AREAS AFFECTED...SE WI...NRN IL...SRN LAKE MI
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 664...
   
   VALID 232010Z - 232145Z
   
   A CONVECTIVE LINE MOVING QUICKLY SEWD WILL LIKELY HAVE A SEVERE
   THREAT OVER THE NEXT 1-3 HOURS. A NEW WW IS BEING ISSUED ACROSS SERN
   WI AND FAR NE IL.
   
   OBJECTIVE ANALYSIS CURRENTLY SHOWS AN AXIS OF INSTABILITY EXTENDING
   NNWWD FROM WRN IL INTO ERN IA. A FAST MOVING CONVECTIVE LINE IS
   MOVING QUICKLY SEWD ALONG THE ERN EDGE OF THE INSTABILITY GRADIENT
   WHERE STRONG VERTICAL SHEAR EXISTS. ALTHOUGH MLCAPE VALUES ARE BELOW
   1000 J/KG AHEAD OF THE LINE...THE SHEAR WILL LIKELY HELP SUSTAIN THE
   LINE AS IT MOVES SEWD INTO FAR SE WI...SRN LAKE MI AND NE IL OVER
   THE NEXT 1-3 HOURS. CONSIDERING THE SPEED OF THE LINE IS NEAR 50
   KT...A WIND DAMAGE THREAT WILL LIKELY CONTINUE. HAIL WILL ALSO BE
   POSSIBLE.
   
   ..BROYLES.. 07/23/2005
   
   
   ATTN...WFO...LOT...MKX...DVN...
   
   43338971 43918834 43418727 43028692 42048717 41668859
   42278977

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   MESOSCALE DISCUSSION 1847
   NWS STORM PREDICTION CENTER NORMAN OK
   0230 PM CDT SUN JUL 24 2005
   
   AREAS AFFECTED...SWRN ND / NWRN SD / EXTREME NERN WY AND SERN MT
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL
   
   VALID 241930Z - 242115Z
   
   STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY THROUGH
   THE AFTERNOON...WITH LARGE HAIL THE PRIMARY THREAT. A WW COULD BE
   REQUIRED LATER THIS AFTERNOON.
   
   VISIBLE IMAGERY INDICATES CU FIELD INCREASING WITH ISOLATED STORMS
   NOW OVER SWRN ND WITHIN WEAK LOW PRESSURE TROUGH. STEEP LOW TO MID
   LEVEL LAPSE RATES AND WEAK WIND PROFILES BELOW 500 MB SUGGEST
   RELATIVELY SHORT LIVED STORMS WITH MAXIMUM HAIL DIAMETERS UP TO 1.50
   INCHES POSSIBLE. HOWEVER...SHEAR PROFILES ARE FORECAST TO INCREASE
   LATER TODAY...WHICH MAY ALLOW FOR ISOLATED SUPERCELLS. GIVEN
   DECREASING BOUNDARY LAYER RH CHARACTERIZED BY DEEP MIXING
   LAYERS...ISOLATED SEVERE WIND GUSTS MAY ALSO OCCUR.
   
   ..JEWELL.. 07/24/2005
   
   
   ATTN...WFO...ABR...BIS...UNR...BYZ...
   
   45690018 43830137 43860387 45450469 46430424 46770378
   47090201 47160061

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   MESOSCALE DISCUSSION 1848
   NWS STORM PREDICTION CENTER NORMAN OK
   0346 PM CDT SUN JUL 24 2005
   
   AREAS AFFECTED...LWR MI...PARTS OF NRN IND AND NW OH
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL
   
   VALID 242046Z - 242245Z
   
   CONVECTIVE INITIATION IS UNCERTAIN...BUT TRENDS ARE BEING CLOSELY
   MONITORED FOR INCREASING SEVERE THREAT AND POSSIBILITY OF A WW.
   
   WITH PASSAGE OF WARM FRONT...SURFACE DEW POINTS HAVE SURGED INTO THE
   MID/UPPER 70S ACROSS MUCH OF LOWER MICHIGAN.  TEMPERATURES HAVE
   GENERALLY CLIMBED INTO THE 90S...CONTRIBUTING TO EXTREME POTENTIAL
   INSTABILITY...WITH MIXED LAYER CAPE NOW IN EXCESS OF 4000 J/KG.
   ELEVATED MIXED LAYER ADVECTING AROUND NORTHERN PERIPHERY OF
   SUBTROPICAL RIDGE IS CAPPING BOUNDARY LAYER...AND FORCING FOR UPWARD
   VERTICAL MOTION WITHIN BROADLY ANTICYCLONIC MID/UPPER FLOW REGIME IS
   UNCERTAIN.
   
   MODELS DO SUGGEST THE PRESENCE OF A WEAK IMPULSE EMBEDDED WITHIN
   THIS REGIME...WHICH COULD AID INITIATION OF STORMS AS CONVECTIVE
   TEMPERATURES ARE APPROACHED LATE THIS AFTERNOON.  LOW-LEVEL FLOW IS
   BECOMING INCREASINGLY CONVERGENT ACROSS LOWER MICHIGAN...IN BROAD
   SURFACE TROUGH EXTENDING SOUTH OF PRIMARY SURFACE LOW OVER NORTHERN
   ONTARIO.  WEAK LOW-LEVEL WARM ADVECTION REGIME PERSISTS AHEAD OF
   TROUGH AXIS...WHICH COULD BECOME FOCUS FOR CONVECTIVE DEVELOPMENT BY
   22-00Z.  THIS APPEARS MOST LIKELY EAST OF LANSING...AND
   WEST/NORTHWEST OF DETROIT...POSSIBLY SOUTHWESTWARD INTO NORTHEASTERN
   INDIANA. 
   
   GIVEN MAGNITUDE OF INSTABILITY...SHEAR PROFILES ARE QUITE STRONG AND
   SUPPORTIVE OF SUPERCELLS WITH POTENTIAL FOR VERY LARGE HAIL/
   DAMAGING WINDS...AND PERHAPS AN ISOLATED STRONG TORNADO.
   
   ..KERR.. 07/24/2005
   
   
   ATTN...WFO...CLE...DTX...APX...IWX...GRR...
   
   41868242 41388337 41328562 42188585 43358549 44088460
   44178350

[CaptinCrunch]

MESOSCALE DISCUSSION 1859
NWS STORM PREDICTION CENTER NORMAN OK
0853 AM CDT MON JUL 25 2005

AREAS AFFECTED...NERN IL...EXTREME SRN LWR MI...NRN IND AND NRN OH

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 251353Z - 251530Z



PLAN VIEW PROFILERS/VWPS INDICATE THAT THE LLJ HAS VEERED TO WSWLY
WITH THE NOSE OF THE JET IMPINGING ON THE FRONT SITUATED FROM THE
CHICAGO AREA EWD INTO NRN OH. RESULTANT WARM ADVECTION HAS LIKELY
BEEN THE IMPETUS FOR INCREASING TSTMS FROM NRN IL INTO NCNTRL IND
SINCE 13Z.

VSBL SATL SHOWS THAT THE DOWNSTREAM AIR MASS WAS ESSENTIALLY
CLOUD-FREE AND THE BOUNDARY LAYER WILL WARM RAPIDLY THROUGH EARLY
AFTN ALONG/S OF THE FRONT. 12Z SOUNDINGS CONTINUE TO SHOW VERY
STEEP MID-LEVEL LAPSE RATES AND GIVEN MAGNITUDE OF HEATING AND
LOW-LEVEL MOISTURE IN PLACE...TSTMS SHOULD CONTINUE TO GROW
UPSCALE/ROOT INTO THE BOUNDARY LAYER AS THEY MOVE EWD.

PRESENCE OF 30-35 KTS OF FLOW IN THE 4-6KM LAYER AND UNIDIRECTIONAL
WSWLY FLOW REGIME THROUGH THE COLUMN WILL BE FAVORABLE FOR STORMS TO
POSSIBLY EVOLVE INTO A BOW ECHO AND PRODUCE DAMAGING WINDS. LARGE
HAIL WILL ALSO BE LIKELY GIVEN THE STEEP LAPSE RATE ENVIRONMENT.

TSTMS WILL LIKELY DEVELOP/MOVE EWD FROM NRN IL/NRN IND INTO EXTREME
SRN LWR MI AND NRN OH THROUGH LATE MORNING. A WW MAY BE REQUIRED
SOON.

[CaptinCrunch]

MESOSCALE DISCUSSION 1861
NWS STORM PREDICTION CENTER NORMAN OK
0131 PM CDT MON JUL 25 2005

AREAS AFFECTED...EXTREME ERN IA...NRN IL...EXTREME NWRN IND AND
PORTIONS OF SRN WI

CONCERNING...SEVERE THUNDERSTORM WATCH 678...

VALID 251831Z - 252000Z



SMALL MCS THAT DEVELOPED ACROSS NERN IL EARLIER TODAY ALONG THE NOSE
OF THE LLJ HAS WEAKENED. WRN EDGE OF COLD DOME HAD SPREAD WWD INTO
SCNTRL WI AND NCNTRL IL INTO A HOT...WELL-MIXED ENVIRONMENT. TSTMS
HAVE RECENTLY INITIATED ALONG THIS INTERFACE WHERE A NARROW
INSTABILITY AXIS EXTENDS NWD INTO THE KMSN AREA. STORMS ARE LIKELY
TO CONTINUE INTENSIFYING IN THIS CORRIDOR AND COULD MOVE NEWD TOWARD
THE KMKE/KORD REGIONS LATER THIS AFTN AS THE BOUNDARY LAYER SLOWLY
MODIFIES ACROSS NERN IL AND SERN WI. THE MAIN SEVERE THREAT WILL BE
LARGE HAIL...THOUGH DAMAGING WINDS AND PERHAPS AN ISOLD TORNADO
COULD ALSO OCCUR.

FARTHER W...LOW-LEVEL FLOW HAS BECOME DIVERGENT ACROSS ERN IA AS
MASS CONVERGENCE/PRESSURE FALLS DEVELOP FARTHER W ACROSS THE PLAINS.
THUS...IT APPEARS THE SEVERE THREATS HAVE DECREASED ACROSS WRN
PORTIONS OF THE WW...AT LEAST THROUGH LATE AFTN/EVE.

[CaptinCrunch]

MESOSCALE DISCUSSION 1862
NWS STORM PREDICTION CENTER NORMAN OK
0153 PM CDT MON JUL 25 2005

AREAS AFFECTED...NRN IND INTO NRN/CNTRL OH

CONCERNING...SEVERE THUNDERSTORM WATCH 677...

VALID 251853Z - 252000Z



THE BOW ECHO HAS MOVED EWD INTO NCNTRL OH AND WILL BE MOVING INTO
NEW SEVERE THUNDERSTORM WATCH 679 SHORTLY. AIR MASS IN WAKE OF THE
MCS ACROSS MUCH OF NRN IND AND NWRN OH HAS STABILIZED. THE ONLY
EXCEPTION WAS ALONG THE EXTREME SRN EDGE OF WS 677 WHERE TRAILING
OUTFLOW BOUNDARY RESIDES FROM THE KOKOMO AREA EWD TO NORTH OF KCMH.
AIR MASS ALONG/S OF THIS BOUNDARY REMAINS VERY UNSTABLE AND BECOMING
LESS CAPPED WITH TIME. THUS...THERE IS SOME CONCERN THAT TSTMS MAY
BACKBUILD WWD FROM CNTRL OH INTO PORTIONS OF ECNTRL/NCNTRL IND
THROUGH MID-LATE AFTN. LARGE HAIL AND DAMAGING WINDS WOULD BE THE
PRIMARY SEVERE THREATS.

HAVE MAINTAINED SRN PORTIONS OF WS 677 TO ACCOUNT FOR THE
POSSIBILITY OF TSTM DEVELOPMENT ALONG THE OUTFLOW BOUNDARY.
ELSEWHERE...THE SEVERE THREATS HAVE DIMINISHED.

[CaptinCrunch]

MESOSCALE DISCUSSION 1863
NWS STORM PREDICTION CENTER NORMAN OK
0155 PM CDT MON JUL 25 2005

AREAS AFFECTED...NRN IA / SRN MN / SERN SD / NERN NEBRASKA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 251855Z - 252100Z



SEVERE THUNDERSTORMS WITH THREAT OF HAIL...WIND AND ISOLATED
TORNADOES ARE EXPECTED TO FORM THIS AFTERNOON. A WW MAY BE REQUIRED.


SURFACE ANALYSIS SHOWS WARM FRONT ACROSS NRN IA INTO NERN
NEBRASKA...WITH PRECIPITATION REINFORCED COLD FRONT AND ASSOCIATED
PRESSURE RISES SPREADING ACROSS SD AND NRN NEBRASKA. STRONG HEATING
IS OCCURRING ACROSS SERN NEBRASKA AND MUCH OF IA...WHERE MLCAPE HAS
INCREASED TO 2000-3000 J/KG. AREA PROFILERS INDICATE FAVORABLE WINDS
FOR SUPERCELLS...ESPECIALLY IN VICINITY OF WARM FRONT ACROSS NRN IA
AND SRN MN.

WITH CONTINUED HEATING SOUTH OF THE BOUNDARY AND WARM ADVECTION
NWD...COVERAGE AND INTENSITY OF STORMS WILL INCREASE OVER THE NEXT
COUPLE HOURS. LARGE HAIL APPEARS LIKELY WITH A FEW DAMAGING WIND
GUSTS. MAIN QUESTION IN REGARD TO TORNADO THREAT IS THE POSSIBILITY
OF NUMEROUS STORMS WITH INTERFERING OUTFLOWS. HIGHEST PROBABILITY OF
A TORNADO WILL BE LATER THIS AFTERNOON...ALONG WARM FRONT WHERE
STORMS WILL HAVE ACCESS TO RELATIVELY HOT AIR TO THE SOUTH WITH
LITTLE SURFACE BASED CIN.

[CaptinCrunch]

MESOSCALE DISCUSSION 1864
NWS STORM PREDICTION CENTER NORMAN OK
0213 PM CDT MON JUL 25 2005

AREAS AFFECTED...CNTRL THROUGH SERN OH AND NWRN WV

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 251913Z - 252045Z



TRAILING PORTION OF THE ERN OH BOW ECHO WAS MOVING SWD ACROSS THE
I-70 CORRIDOR INTO CNTRL OH AT MID-AFTN. STRONG TSTMS WERE
DEVELOPING ALONG THIS OUTFLOW BOUNDARY WHERE MLCAPES WERE IN EXCESS
OF 3500 J/KG. VWPS SUGGEST THAT WSWLY LOW/MID-LEVEL FLOW WAS
FEEDING STEEP LAPSE RATES INTO THE STORMS WITH LARGE HAIL POSSIBLE.
WHILE THE PRIMARY HIGH WIND POTENTIAL WILL BE TRANSLATING ESEWD INTO
THE UPPER OH VLY /WW 679/... PROPAGATION VECTORS SUGGEST THAT THE
TRAILING STORMS WILL MOVE MORE SLOWLY SEWD TOWARD THE PARKERSBURG
AREA /MID-OH VLY/ BY LATE-AFTN. VERY HEAVY RAINFALL...LARGE HAIL
AND GUSTY WINDS WILL BE POSSIBLE WITH THESE STORMS. WILL ALSO
MONITOR THE BACKBUILDING/TRAINING POTENTIAL FROM CNTRL THROUGH SERN
OH/NWRN WV. THERMODYNAMIC/ KINEMATIC ENVIRONMENT ARE SUPPORTIVE FOR
UPSTREAM STORM DEVELOPMENT INTO THE INSTABILITY AXIS AND TRAIN SEWD
INTO WV WITH VERY HEAVY RAINFALL POTENTIAL.

ANOTHER WW FARTHER SOUTH WILL PROBABLY NOT BE NEEDED.

[TexasStooge]

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   MESOSCALE DISCUSSION 1865
   NWS STORM PREDICTION CENTER NORMAN OK
   0350 PM CDT MON JUL 25 2005
   
   AREAS AFFECTED...NERN IL AND SMALL PART OF NRN IND
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 677...678...
   
   VALID 252050Z - 252145Z
   
   VALID PORTIONS OF SEVERE THUNDERSTORM WATCHES 677 AND 678 EXPIRE AT
   22Z.  ATTM...THERE IS NO PLAN TO REISSUE/CONTINUE THESE WATCHES.
   
   EARLIER BOW ECHO HAS MOVED WELL EAST OF THE REGION.  TRAILING
   OUTFLOW BOUNDARY EXTENDS NWWD THROUGH NRN IND AND NERN IL.
   STRONGEST LOW-LEVEL FLOW/MASS CONVERGENCE HAS NOW REDEVELOPED/
   SHIFTED WWD INTO THE UPPER MS VLY.  THUS...IT APPEARS THAT THE
   HIGHEST THREATS FOR SEVERE WEATHER WILL BE LOCATED ACROSS NRN
   IA...SRN WI AND MN THROUGH LATE AFTN.
   
   ..RACY.. 07/25/2005
   
   
   ATTN...WFO...IWX...IND...LOT...DVN...
   
   40598838 42048956 42438943 42388724 41828700 41108704
   40778497 40508496 40508758

[CaptinCrunch]

MESOSCALE DISCUSSION 1868
NWS STORM PREDICTION CENTER NORMAN OK
0453 PM CDT MON JUL 25 2005

AREAS AFFECTED...SERN NEBRASKA / SWRN IA / NERN KS / FAR NWRN MO

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 252153Z - 252300Z



STORMS WILL INCREASE IN COVERAGE THROUGH THE EVENING HOURS...WITH
LARGE HAIL AND DAMAGING WIND POSSIBLE. A WW MAY BE REQUIRED.

A VERY HOT AND UNSTABLE AIR MASS RESIDES E OF SFC COLD FRONT WHICH
WILL CONTINUE TO MOVE SEWD. CONVERGENCE ALONG AND N OF THIS BOUNDARY
WILL INCREASE AS 30-40 KT SSWLY LOW LEVEL JET PERSISTS. VEERING LOW
LEVEL WIND PROFILES WITH MODEST WLY FLOW ALOFT SHOULD ALLOW FOR A
FEW SEVERE STORMS. LOCALLY STRONG DOWNBURSTS WOULD BE THE MAIN
THREAT INTO KS...WITH LARGE HAIL BECOMING INCREASINGLY PROBABLE
FARTHER N INTO IA.

[TexasStooge]

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   MESOSCALE DISCUSSION 1879
   NWS STORM PREDICTION CENTER NORMAN OK
   1031 AM CDT TUE JUL 26 2005
   
   AREAS AFFECTED...SERN LWR MI...EXTREME NWRN OH...NRN IND AND CNTRL
   IL
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL
   
   VALID 261531Z - 261700Z
   
   WEATHER WATCHES WILL LIKELY BE REQUIRED BY MID-DAY TO EARLY AFTN
   FROM SERN LWR MI...EXTREME NWRN OH SWWD INTO PARTS OF CNTRL IL.
   
   15Z MESOANALYSIS PLACES A PRE-FRONTAL TROUGH FROM THE THUMB OF LWR
   MI SWWD INTO NERN IL VCNTY KORD.  AIR MASS ALONG/AHEAD OF THIS
   FEATURE IS BECOMING UNSTABLE WITH MLCAPES 1000-1500 J/KG.  GIVEN
   UNCAPPED ENVIRONMENT...TSTMS WILL CONTINUE TO DEVELOP THROUGH EARLY
   AFTN.  FAST WSWLY FLOW THROUGH THE COLUMN /AOA 45 KTS 3-6KM/ WILL BE
   FAVORABLE FOR TSTMS TO EVOLVE INTO LINE SEGMENTS WITH DAMAGING
   WINDS/HAIL. 
   
   EXPECT THE TSTMS OVER SRN LWR MI ATTM ARE PROBABLY SLIGHTLY
   ELEVATED...BUT WILL PROBABLY ROOT INTO THE UNSTABLE BOUNDARY LAYER
   BY 18Z.  ACTIVITY WILL DEVELOP/BACKBUILD SWWD ALONG THE TROUGH INTO
   CNTRL IL LATER THIS AFTN.  AS A RESULT...WW/S WILL LIKELY BE NEEDED.
   
   ..RACY.. 07/26/2005
   
   
   ATTN...WFO...CLE...ILN...DTX...IWX...GRR...IND...LOT...ILX...
   
   42438250 41378313 40878430 40368604 39938771 39558913
   39809038 40759037 41138902 41408774 41868673 42388504
   43028357 43288255

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   MESOSCALE DISCUSSION 1880
   NWS STORM PREDICTION CENTER NORMAN OK
   0100 PM CDT TUE JUL 26 2005
   
   AREAS AFFECTED...WRN NY...NWRN PA...ECNTRL OH AND NRN WV PNHDL
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL
   
   VALID 261800Z - 261930Z
   
   VSBL IMAGERY SHOWS AN ARC OF SHARPENING CU/TCU FROM SWRN NY ACROSS
   NWRN PA INTO NCNTRL OH.  REPLAY OF PLAN-VIEW SURFACE OBS SUGGEST A
   SUBTLE WIND SHIFT ASSOCIATED WITH THIS LINE AND A WEAKLY BACKING
   LOW-LEVEL FLOW AHEAD OF THE LINE...PRIMARILY OVER NWRN PA.
   INCREASING MASS CONVERGENCE AND WEAKENING CINH MAY BE SUFFICIENT FOR
   CONTINUED TSTM DEVELOPMENT THROUGH THE AFTN.  BOUNDARY LAYER
   CONTINUES TO DESTABILIZE EWD INTO WRN NY AND WRN PA WITH MLCAPES AOA
   1000 J/KG...RANGING INTO THE 1500-2000 J/KG RANGE ACROSS ERN OH.
   
   STRONGER FLOW ALOFT EXISTS ACROSS NY /AOA 50KTS/...BUT AT LEAST
   30-40 KTS AS FAR S AS I-70 PER VWPS.  THIS WILL BE SUPPORTIVE OF
   ORGANIZED TSTMS...POSSIBLY SUPERCELLS. MAIN THREAT WILL BE DAMAGING
   WINDS AS STORMS EVOLVE INTO LINE SEGMENTS/SMALL SCALE BOWS.
   
   THE SEVERE THREAT DOES NOT SEEM TO BE TERRIBLY FOCUSED ON ANY GIVEN
   AREA.  EVOLUTION OF THE TSTMS WILL BE MONITORED CLOSELY AND WW/S MAY
   BE NEEDED FOR PARTS OF THE REGION LATER THIS AFTN.
   
   ..RACY.. 07/26/2005
   
   
   ATTN...WFO...BGM...BUF...CTP...PBZ...RLX...CLE...ILN...
   
   41548001 42457921 43257856 43677708 43227669 41917771
   40807912 40258031 39778186 39958281 40568312

[CaptinCrunch]

MESOSCALE DISCUSSION 1883
NWS STORM PREDICTION CENTER NORMAN OK
0329 PM CDT TUE JUL 26 2005

AREAS AFFECTED...NE OK/FAR SE KS/FAR NW AR AND SW/CNTRL MO

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 262029Z - 262230Z



ISOLD SEVERE THREAT WILL BE POSSIBLE THROUGH EARLY EVENING INVOF
COLD FRONT FROM NE OK INTO CNTRL MO. ALTHOUGH NOT CURRENTLY
ANTICIPATED...WILL CONTINUE TO MONITOR TRENDS FOR POSSIBLE WATCH.

RECENT VIS SATELLITE TRENDS DEPICT DEEPENING SW-NE ORIENTED CU FIELD
WITHIN IMMEDIATE PRE-COLD FRONTAL CONFLUENCE FROM FAR NE OK INTO
SCNTRL MO. MODIFIED RUC SOUNDINGS SUGGEST POTENTIAL FOR 1500-2000
J/KG MLCAPE IN AMBIENT WARM SECTOR. GIVEN FRONTAL FORCING/WEAKLY
CAPPED AIRMASS ALONG THE FRONT...STORMS EXPECTED TO INCREASE IN
AREAL COVERAGE REMAINDER OF THE AFTERNOON FROM NE OK INTO CNTRL MO.
ALONG/AHEAD OF THE FRONT AMIDST A HOT/WELL MIXED AIRMASS...POTENTIAL
WILL EXIST FOR ISOLD DAMAGING WIND GUSTS WITH INITIAL SURFACE BASED
DEVELOPMENT...BEFORE STORMS ARE EVENTUALLY UNDERCUT BY THE SE MOVING
FRONTAL BOUNDARY. ISOLD LARGE HAIL WILL ALSO BE POSSIBLE...ALTHOUGH
MODEST MID LEVEL LAPSE RATES/VERTICAL SHEAR WILL BE LIMITING
FACTORS.

[CaptinCrunch]

MESOSCALE DISCUSSION 1884
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT TUE JUL 26 2005

AREAS AFFECTED...E-CNTRL IL ACROSS NRN IND

CONCERNING...SEVERE THUNDERSTORM WATCH 686...

VALID 262159Z - 262300Z



WW 686 EXPIRES AT 23Z AND A REPLACEMENT WW MAY BE REQUIRED WITHIN
THE HOUR.

REGIONAL RADAR IMAGERY SHOWS AN INCREASE IN TSTM COVERAGE AND
INTENSIFY FROM S OF MMO TO S OF PIA...LIKELY IN ASSOCIATION WITH
SHORTWAVE TROUGH AND 50-55 KT MID-LEVEL SPEED MAX. MOVING INTO NWRN
IL. MEANWHILE...MESOANALYSIS INDICATES PRIMARY SYNOPTIC FRONT FROM S
OF SBN TO NEAR LOCATION OF AFOREMENTIONED STORMS OVER IL TO NEAR
SZL. ADDITIONAL STRONG TO POTENTIAL SEVERE STORMS ARE ALSO IN
PROGRESS ALONG PRE-FRONTAL CONFLUENCE BAND FROM 40 SW SBN TO 35 WSW
TOL.

AIR MASS ALONG/S OF COLD FRONT REMAINS HOT AND MOIST LATE THIS
AFTERNOON/EARLY THIS EVENING WITH MLCAPES OF 1500-3000 J/KG.
INCREASE IN DEEP-LAYER VERTICAL SHEAR WITH APPROACH OF MID-LEVEL
SPEED MAX FROM THE W...IN CONJUNCTION WITH THIS INSTABILITY ARE
EXPECTED TO SUSTAIN ORGANIZED CLUSTERS OF STORMS CAPABLE OF ISOLATED
HAIL AND DAMAGING WINDS.

[TexasStooge]

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   MESOSCALE DISCUSSION 1885
   NWS STORM PREDICTION CENTER NORMAN OK
   0616 PM CDT TUE JUL 26 2005
   
   AREAS AFFECTED...CNTRL/SRN PA...POSSIBLY INTO MD/WV
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL
   
   VALID 262316Z - 270045Z
   
   POTENTIAL FOR DAMAGING WINDS WILL INCREASE S OF WW/S 687 AND 689 BY
   00Z AND A NEW WW MAY BE REQUIRED.
   
   A BOWING STRUCTURE HAS EVOLVED THIS EVENING FROM E OF ROC TO E OF
   BFD TO S OF FKL WITH A SYSTEM MOTION OF 325/35 KTS. ADDITIONAL
   STRONG TO SEVERE STORMS HAVE ALSO RECENTLY DEVELOPED NEAR PIT WITH
   MORE OF A ESEWD MOTION. RUC OBJECTIVE FIELDS INDICATE THAT AIR MASS
   ACROSS CNTRL/SRN PA REMAINS MODERATELY UNSTABLE WITH MLCAPES OF
   2000-2500 J/KG...OWING TO HOT AND MOIST BOUNDARY-LAYER CONDITIONS.
   GIVEN THAT AFOREMENTIONED BOW HAS ESTABLISHED AN ORGANIZED COLD
   POOL...SYSTEM WILL LIKELY CONTINUE SEWD FOR THE NEXT FEW HOURS WITH
   A DAMAGING WIND THREAT SPREADING S OF WW/S 687 AND 689 BY 00Z.
   
   ..MEAD.. 07/26/2005
   
   
   ATTN...WFO...PHI...BGM...CTP...LWX...PBZ...
   
   39597982 40097967 41107755 41447619 41237517 40007522
   39277712 38837880

[TexasStooge]

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   MESOSCALE DISCUSSION 1886
   NWS STORM PREDICTION CENTER NORMAN OK
   0902 PM CDT TUE JUL 26 2005
   
   AREAS AFFECTED...E-CNTRL IL EWD ACROSS NRN AND CNTRL IND/OH INTO WRN
   PA
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 687...690...
   
   VALID 270202Z - 270300Z
   
   THROUGH 03Z...IT APPEARS THE GREATEST THREAT OF PRIMARILY DAMAGING
   WINDS WILL EXIST FROM CNTRL IND INTO N-CNTRL OR NWRN OH. WW 687 WILL
   EXPIRE AT 03Z AND A NEW WW MAY NEED TO BE CONSIDERED SHOULD STORMS
   MAINTAIN THEIR INTENSITY.
   
   AS OF 0150Z...REGIONAL RADAR IMAGERY SHOWS A NE-SW ORIENTED LINE OF
   STRONG TO SEVERE STORMS FROM 30 E FWA TO 20 SE LAF MOVING 250/30-35
   KTS. SHORTWAVE TROUGH AND ASSOCIATED 50-55 KT MID-LEVEL SPEED MAX
   COUPLED WITH A MODERATELY UNSTABLE AIR MASS CONTINUES TO SUSTAIN
   THIS ACTIVITY AHEAD OF COLD FRONT SLOWLY SAGGING SWD THROUGH AREA.
   WHILE STORMS HAVE BECOME ALIGNED NEARLY PARALLEL WITH
   MID/UPPER-LEVEL WIND FIELDS...EMBEDDED BOWING STRUCTURES OBSERVED
   WITHIN THE LINE WILL REMAIN CAPABLE OF DAMAGING WINDS. ORGANIZED
   WIND THREAT MAY PERSIST BEYOND 03Z INTO PORTIONS OF NWRN/W-CNTRL OH
   AND A NEW WW MAY BE REQUIRED BEFORE WW 687 EXPIRES.
   
   OTHER CLUSTERS OF STRONG TO SEVERE STORMS SW OF CAK AND NE OF PIT
   WILL REMAIN CAPABLE OF ISOLATED DAMAGING WINDS FOR THE NEXT 1-2
   HOURS...THOUGH STORMS SHOULD TEND TO WEAKEN AS THEY MOVE INTO MORE
   STABLE AIR MASS.
   
   ..MEAD.. 07/27/2005
   
   
   ATTN...WFO...CTP...LWX...PBZ...RLX...CLE...ILN...DTX...IWX...IND...LOT...ILX...LSX...
   
   40798890 42248272 41688249 41307708 40537737 40327839
   39717890 39348106 39988277 38828897

[TexasStooge]

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   MESOSCALE DISCUSSION 1888
   NWS STORM PREDICTION CENTER NORMAN OK
   1055 AM CDT WED JUL 27 2005
   
   AREAS AFFECTED...INTERIOR NEW ENGLAND/ERN NY SWD INTO CNTRL
   APPALACHIANS
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL
   
   VALID 271555Z - 271800Z
   
   TSTMS ARE EXPECTED TO DEVELOP BY 18-20Z FROM ERN NY SWD INTO THE
   CNTRL APPALACHIANS/DELMARVA REGION.  MAIN SEVERE WEATHER THREAT WILL
   BE DAMAGING WIND GUSTS.
   
   WATER VAPOR IMAGERY SHOWS A SUBTLE WAVE MOVING NEWD ACROSS
   OH...EMBEDDED WITHIN THE LARGER SHORTWAVE TROUGH MOVING EWD ACROSS
   THE MIDWEST.  THE WAVE AND ASSOCIATED LARGE SCALE ASCENT SHOULD MOVE
   ACROSS THE UPPER OH VLY/MIDDLE ATLANTIC AND INTO NEW ENGLAND LATER
   THIS AFTN/EVE.
   
   THOUGH THE PRIMARY SYNOPTIC FRONT WILL SLOWLY APPROACH THE
   REGION...A LEE-TROUGH WILL STRENGTHEN ACROSS ERN NY SWD INTO ERN VA.
   AIR MASS VCNTY THIS TROUGH WILL REMAIN VERY UNSTABLE OWING TO HOT
   TEMPERATURES AND RICH LOW-LEVEL MOISTURE.  MLCAPES WILL RANGE FROM
   2000-2500 J/KG.  MID-LEVEL TEMPERATURES ARE WARM /MINUS 4-6C AT
   H5/...BUT AS LARGE SCALE ASCENT ARRIVES...TSTMS WILL GRADUALLY
   DEVELOP ALONG THE HIGHER TERRAIN.  INITIAL STORMS WILL PROBABLY FORM
   OVER CNTRL PA/ERN NY EARLY THIS AFTN...WITH LATER DEVELOPMENT
   EXPECTED ALONG THE LEE-TROUGH FROM SCNTRL/SERN PA SWD INTO ERN VA.
   
   MODEST WSWLY UNIDIRECTIONAL FLOW THROUGH THE COLUMN WILL PROMOTE A
   SLOW EVOLUTION INTO SMALL SCALE LEWPS/BOWS.  THE STRONGEST VERTICAL
   SHEAR WILL BE CONFINED TO AREAS PRIMARILY NORTH OF THE MASON-DIXON
   LINE WHERE BRIEF SUPERCELL STRUCTURES MAY BE POSSIBLE. MAIN SEVERE
   THREAT WILL BE DAMAGING WIND GUSTS...THOUGH A FEW STRONGER STORMS
   MAY PRODUCE MARGINALLY SEVERE HAIL...PARTICULARLY WITH ANY
   SUPERCELLS.
   
   ONE OR MORE SEVERE THUNDERSTORMS WATCHES MAY BE REQUIRED BY EARLY
   AFTN ACROSS THE REGION.
   
   ..RACY.. 07/27/2005
   
   
   ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...AKQ...CTP...LWX...PBZ...
   
   38597569 37937635 37577706 37807787 38327865 39297919
   40207880 41077782 41807612 42617514 43357408 43727362
   43857266 43627199 42897205 42047265 41307321 40187419
   39417510

[TexasStooge]

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   MESOSCALE DISCUSSION 1890
   NWS STORM PREDICTION CENTER NORMAN OK
   0208 PM CDT WED JUL 27 2005
   
   AREAS AFFECTED...NEW ENGLAND AND ERN NY
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 692...
   
   VALID 271908Z - 272115Z
   
   18Z ALBANY SOUNDING INDICATES THAT THE WARM SECTOR HAS BECOME
   MODERATELY UNSTABLE WITH MLCAPE OF 2330 J/KG AND NO INHIBITION.
   PRIMARY CONVERGENCE AXIS REMAINS ALONG THE PRE-FRONTAL/LEE TROUGH
   SITUATED FROM CNTRL NH ACROSS SRN VT AND INTO NERN PA. TSTMS REMAIN
   COINCIDENT WITH THIS TROUGH...BUT THERE ARE INDICATIONS THAT OTHER
   STORMS WILL FORM FARTHER E ACROSS NRN NJ...SERN NY...NWRN CT AND WRN
   MA THROUGH 20Z. 
   
   THE ALBANY SOUNDING ALSO SHOWS A FAVORABLY SHEARED ENVIRONMENT TO
   SUPPORT SUPERCELLS THAT WILL MOST LIKELY BE EMBEDDED WITHIN SHORT
   LINE SEGMENTS. STRONGER CELLS MAY PRODUCE HAIL...BUT THE PRIMARY
   CONCERN IS FOR DAMAGING WIND GUSTS ACROSS INTERIOR NEW ENGLAND AND
   ERN NY...INCLUDING LONG ISLAND.  TSTMS WILL GRADUALLY INTENSIFY AND
   MAY EVOLVE INTO SMALL LEWPS/BOWS AS THEY HEAD EWD INTO SRN
   NH...CNTRL/WRN MA...CT AND THE NEW YORK CITY METRO AREA THROUGH LATE
   AFTN/EVE.
   
   ..RACY.. 07/27/2005
   
   
   ATTN...WFO...GYX...BOX...BTV...OKX...ALY...BGM...
   
   41717555 45067181 44386889 40637242 41107365

[TexasStooge]

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   MESOSCALE DISCUSSION 1891
   NWS STORM PREDICTION CENTER NORMAN OK
   0235 PM CDT WED JUL 27 2005
   
   AREAS AFFECTED...MID-ATLANTIC REGION
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 693...
   
   VALID 271935Z - 272130Z
   
   LATEST VWP PLOTS AND THE 18Z ABERDEEN MARYLAND SOUNDING INDICATE
   THAT THE STRONGEST VERTICAL SHEAR/H5 FLOW EXIST N OF THE MASON-DIXON
   LINE.  BUT...THE AIR MASS HAS BECOME MODERATELY UNSTABLE WITH
   MLCAPES OF 2000-2500 J/KG AND ALMOST NON-EXISTENT INHIBITION OVER
   ALL OF THE MIDDLE ATLANTIC REGION.  VSBL SATELLITE SEEMS TO INDICATE
   THAT THE CU FIELD ALONG THE HIGHER TERRAIN/VCNTY SEA-BREEZE
   BOUNDARIES IS BEGINNING TO SPROUT AND TSTM INITIATION IS LIKELY FROM
   SCNTRL PA SWD INTO WRN VA BY 20Z.  OUTFLOW BOUNDARIES EMANATING FROM
   CONVECTION WEST OF THE APPALACHIAN CREST MAY AUGMENT LOW-LEVEL
   CONVERGENCE AS WELL.
   
   THE SLIGHTLY STRONGER FLOW ACROSS ERN PA AND NJ MAY BE SUFFICIENT
   FOR BRIEF SUPERCELLULAR STRUCTURES.  FARTHER S...DESPITE WEAKER WIND
   FIELDS...THE WLY UNIDIRECTIONAL FLOW REGIME AND LOW-LEVEL INVERTED-V
   THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE FOR SHORT LINE SEGMENTS
   TO BOW...PRODUCING DAMAGING WIND GUSTS.  ACTIVITY SHOULD MOVE INTO
   THE HARRISBURG AND BALTIMORE/WASHINGTON AREAS BETWEEN 21-23Z.
   
   ..RACY.. 07/27/2005
   
   
   ATTN...WFO...OKX...PHI...AKQ...CTP...LWX...RNK...
   
   38057973 40837708 40757333 37937605

[CaptinCrunch]

MESOSCALE DISCUSSION 1893
NWS STORM PREDICTION CENTER NORMAN OK
0444 PM CDT WED JUL 27 2005

AREAS AFFECTED...SRN AR/FAR NRN LA INTO NW MS

CONCERNING...SEVERE THUNDERSTORM POTENTIAL...HEAVY RAINFALL

VALID 272144Z - 272345Z



ISOLD PULSE-TYPE DAMAGING WET MICROBURSTS/MARGINALLY SEVERE HAIL
WILL BE POSSIBLE THROUGH EARLY EVENING. LOCALIZED RAINFALL RATES OF
2 IN/HR CAN BE EXPECTED.

PERSISTENT COMPLEX OF STORMS CONTINUES TO PROGRESSIVELY EVOLVE
ACROSS SW AR AT THIS TIME. ACTIVITY IS OCCURRING INVOF SYNOPTIC COLD
FRONT...WITH DEVELOPING COLD POOL/MCV EXPECTED TO PROVIDE FURTHER
FOCUS FOR ADDITIONAL DEVELOPMENT/EWD EXPANSION ACROSS THE REMAINDER
OF SRN AR/FAR NRN LA INTO NW MS. DOWNSTREAM AMBIENT AIRMASS IS
CHARACTERIZED BY MODERATE INSTABILITY...WITH MODIFIED RUC SOUNDINGS
SUGGESTING AS MUCH AS 2000-2500 J/KG MLCAPE. ADDITIONALLY...GIVEN
MODEST VERTICAL SHEAR/SLOW STORM MOTIONS AND PRECIPITABLE WATER
VALUES AROUND 1.7 INCHES...LOCALLY HEAVY RAINFALL WITH RATES OF 2
IN/HR CAN BE EXPECTED.