MESOSCALE DISCUSSION NWS STORM PREDICTION CENTER

[CaptinCrunch]

MESOSCALE DISCUSSION 1125
NWS STORM PREDICTION CENTER NORMAN OK
0343 PM CDT THU JUN 02 2005

AREAS AFFECTED...CENTRAL/ERN COLORADO

CONCERNING...TORNADO WATCH 376...

VALID 022043Z - 022245Z



CONTINUE WW.

BOUNDARY LAYER WINDS HAVE TAKEN ON MORE OF AN EASTERLY COMPONENT
DURING THE PAST COUPLE OF HOURS EAST OF THE IMMEDIATE FRONT RANGE
AREA...ACROSS THE REMAINDER OF NORTHEAST/EAST CENTRAL COLORADO.
MOISTENING UPSLOPE REGIME WILL CONTRIBUTE TO FURTHER DESTABILIZATION
AS STRONGER MID-LEVEL FORCING SHIFTS FROM THE DENVER VICINITY
EASTWARD ALONG THE INTERSTATE 70 CORRIDOR NOW THROUGH 03/00Z.

40+ KT WESTERLY MID-LEVEL FLOW IS CONTRIBUTING TO STRONG SHEAR
PROFILES FAVORABLE FOR SUPERCELLS...WHICH SHOULD BECOME MORE
NUMEROUS EAST OF DENVER INTO THE FORT MORGAN/YUMA/LIMON/BURLINGTON
CO AREAS LATE THIS AFTERNOON. AS STORMS APPROACH THE COLORADO/
KANSAS BORDER...STRONGER CELLS WILL BE CAPABLE OF VERY LARGE HAIL/
DAMAGING WIND GUSTS AND ISOLATED TORNADOES.

[CaptinCrunch]

MESOSCALE DISCUSSION 1135
NWS STORM PREDICTION CENTER NORMAN OK
0645 AM CDT FRI JUN 03 2005

AREAS AFFECTED...NW TX...WRN OK...SRN KS

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 031145Z - 031315Z



SCATTERED STORMS WILL CONTINUE TO DEVELOP ACROSS NW TX AND WRN OK
OVER THE NEXT 1 TO 2 HOURS. THE STORMS WILL MOVE NEWD WITH A
POTENTIAL FOR LARGE HAIL AND WIND DAMAGE. A NEW WW MAY BECOME
NECESSARY.

WATER VAPOR IMAGERY CURRENTLY SHOWS AN UPPER-LEVEL TROUGH LOCATED
ACROSS NM WITH RUC ANALYSIS SHOWING STRONG LIFT SPREADING EWD ACROSS
THE SRN PLAINS. IN ADDITION...FORECAST SOUNDINGS SHOW SUBSTANTIAL
ELEVATED CAPE WITH MUCAPE VALUES OF 3000 TO 4000 J/KG MOSTLY ABOVE
700 MB. AS THE LARGE-SCALE ASCENT AHEAD OF THE TROUGH COMES OUT IN
INTO THE PLAINS OVER THE NEXT FEW HOURS...SCATTERED STRONG
THUNDERSTORMS SHOULD DEVELOP. OBJECTIVE ANALYSIS SHOWS DEEP LAYER
SHEAR OF 20 TO 25 KT AND THIS COMBINED WITH THE ELEVATED INSTABILITY
SHOULD BE ENOUGH FOR MULTICELL SEVERE STORMS WITH LARGE HAIL AND
WIND DAMAGE POSSIBLE.

[CaptinCrunch]

MESOSCALE DISCUSSION 1137
NWS STORM PREDICTION CENTER NORMAN OK
1019 AM CDT FRI JUN 03 2005

AREAS AFFECTED...WRN OK

CONCERNING...SEVERE THUNDERSTORM WATCH 383...

VALID 031519Z - 031715Z



CONTINUE WW. TRENDS ARE BEING MONITORED FOR POSSIBILITY OF
INCREASING SEVERE THREAT ACROSS PARTS OF SOUTHERN KANSAS/EASTERN
OKLAHOMA.

SLOW INCREASE IN CONVECTIVE DEVELOPMENT IS ONGOING ACROSS WEST
CENTRAL OKLAHOMA. ACTIVITY APPEARS TO BE IN RESPONSE TO ENHANCEMENT
OF UPWARD VERTICAL MOTION FIELD ASSOCIATED WITH STRONGER DIVERGENT
UPPER FLOW DOWNSTREAM OF TROUGH LIFTING OUT OF THE MEXICAN PLATEAU.
SOUTHWESTERLY MID-LEVEL JET STREAK IS PROGGED TO DEVELOP NORTHWARD
OUT OF WEST TEXAS INTO CENTRAL OKLAHOMA BY EARLY AFTERNOON...AND
EVOLUTION OF GROWING CONVECTIVE CLUSTER LIKELY WILL CONTINUE.

CONVECTION CURRENTLY IS BASED ABOVE NEAR SURFACE INVERSION
LAYER...BUT AS SURFACE HEATING CONTINUES...STORMS SHOULD GRADUALLY
BECOME ROOTED IN DEEPENING BOUNDARY LAYER WITH CAPE UP TO 2000 J/KG.
AS SHEAR PROFILES STRENGTHEN WITH APPROACH OF MID-LEVEL JET
STREAK...CLUSTER OF STORMS MAY BECOME BETTER ORGANIZED WITH GREATER
RISK FOR DAMAGING WIND GUSTS...IN ADDITION TO CONTINUING POTENTIAL
FOR LARGE HAIL.

[CaptinCrunch]

MESOSCALE DISCUSSION 1194
NWS STORM PREDICTION CENTER NORMAN OK
0928 AM CDT MON JUN 06 2005

AREAS AFFECTED...CENTRAL-ERN PA/CENTRAL-ERN NY/NRN NJ/WRN CT/WRN
MA/WRN VT

CONCERNING...OUTLOOK UPGRADE

VALID 061428Z - 061530Z



THE 1630Z CONVECTIVE DAY 1 OUTLOOK WILL UPGRADE PORTIONS OF THE NERN
STATES TO A MODERATE RISK. THIS MODERATE RISK INCLUDES CENTRAL AND
ERN PA...CENTRAL AND ERN NY...NRN NJ...WRN CT...WRN MA AND WRN VT.

FOR METEOROLOGICAL DETAILS...PLEASE REFER TO THE 1630Z CONVECTIVE
OUTLOOK.

[CaptinCrunch]

MESOSCALE DISCUSSION 1203
NWS STORM PREDICTION CENTER NORMAN OK
0222 PM CDT MON JUN 06 2005

AREAS AFFECTED...WRN SD/WRN NEB AND ECNTRL/SE WY INTO ERN CO/FAR WRN
KS

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 061922Z - 062115Z



SEVERE THREAT EXPECTED TO INCREASE BY LATE AFTERNOON FROM THE WY/CO
HIGHER TERRAIN INTO PORTIONS OF THE HIGH PLAINS. MONITORING TRENDS
FOR POSSIBLE WATCH/ES.

AHEAD OF LEADING SHORTWAVE TROUGH OVER SRN ID/NRN UT INTO WRN
WY...CUMULUS CONTINUES TO BUILD OVER THE HIGHER TERRAIN OF WY/CO
THIS AFTERNOON...AND IN DEEPLY MIXED ENVIRONMENT ACROSS PORTIONS OF
ERN CO INTO FAR WRN KS. ALTHOUGH SOME CINH REMAINS ACROSS THE WRN
SD/WRN NEB/WRN KS HIGH PLAINS...MODIFIED 18Z SPECIAL RAOBS FROM
RAP/LBF PORTRAY POTENTIAL FOR MODERATELY UNSTABLE AIRMASS OF 2000
J/KG OR GREATER. RELATIVELY GREATER DEEP LAYER SHEAR /30-40 KTS/ FOR
SUSTAINED SUPERCELLS/LONGER DURATION SEVERE THREAT EXISTS ACROSS ERN
WY/WRN SD/WRN NEB...DIMINISHING TO AROUND 20 KTS PROGRESSIVELY SWD
ACROSS ERN CO/FAR WRN KS. WILL CONTINUE TO MONITOR DEVELOPMENTAL
TRENDS...HOWEVER WW APPEARS LIKELY AT LEAST ACROSS ERN WY/WRN SD/WRN
NEB BY 21Z.

[CaptinCrunch]

MESOSCALE DISCUSSION 1204
NWS STORM PREDICTION CENTER NORMAN OK
0315 PM CDT MON JUN 06 2005

AREAS AFFECTED...NE MT/WRN ND

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 062015Z - 062215Z



THREAT FOR SUPERCELLS WITH VERY LARGE HAIL/ISOLD TORNADOES TO
INCREASE BY LATE THIS AFTERNOON/EARLY EVENING ACROSS NE MT INTO WRN
ND. A TORNADO WATCH WILL BE NEEDED WITHIN THE NEXT HOUR OR TWO.

SOUTHEASTERLY WINDS ACROSS THE NORTHERN HIGH PLAINS CONTINUE TO
TRANSPORT RICHER BOUNDARY LAYER MOISTURE NWWD INTO ERN MT/WRN
ND...WHILE STRONG DYNAMIC ASCENT WILL OVERSPREAD THE REGION
REMAINDER OF THE AFTERNOON OWING TO EJECTING SRN ID/NRN UT/WRN WY
SHORTWAVE TROUGH. ALTHOUGH INITIALLY HAMPERED BY CLOUD
COVER...AIRMASS CONTINUES TO DESTABILIZE ACROSS NE MT PER VIS
SATELLITE TRENDS/MODIFIED RUC SOUNDINGS. STRONGLY CURVED
HODOGRAPHS/INCREASING DEEP LAYER SHEAR OF 40 KTS OR GREATER -- PER
GLASGOW WSR-88D VAD AND RUC FCST SOUNDINGS -- WILL BE FAVORABLE FOR
SUPERCELLS...WITH ATTENDANT THREAT FOR VERY LARGE HAIL/ISOLD
TORNADOES.

[CaptinCrunch]

MESOSCALE DISCUSSION 1205
NWS STORM PREDICTION CENTER NORMAN OK
0335 PM CDT MON JUN 06 2005

AREAS AFFECTED...SRN NEW ENGLAND INTO ERN PA/NJ

CONCERNING...SEVERE THUNDERSTORM WATCH 416...418...

VALID 062035Z - 062130Z



BOW ECHO PRODUCING DAMAGING WINDS WILL MOVE INTO SRN VT TO WRN CT
THROUGH 21Z...WITH CONTINUED THREAT FOR DAMAGING WIND GUSTS FURTHER
SOUTH ACROSS ERN PA INTO CENTRAL/NRN NJ AND WRN LONG ISLAND.

...ERN NY INTO NEW ENGLAND...
REGIONAL RADAR TRENDS INDICATED THE FASTEST PORTION OF A BOW
ECHO...WHICH EXTENDED FROM EAST CENTRAL TO SERN NY...AT 30-45 KT..
WITH THE 45 KT SPEED EXPECTED TO MOVE INTO SRN VT THROUGH 21Z. AIR
MASS ACROSS MUCH OF WRN NEW ENGLAND REMAINS MODERATELY UNSTABLE
WHICH WILL SUSTAIN EWD MOVEMENT OF THE BOW...SUPPORTING A CONTINUED
THREAT FOR DAMAGING WINDS.

...ERN PA INTO NJ/WRN LONG ISLAND...
MLCAPE OF 1500-2500 J/KG SWD ACROSS ERN PA INTO NJ AND AROUND 1000
J/KG OVER WRN LONG ISLAND WILL SUPPORT A THREAT FOR SEVERE STORMS AS
BROKEN LINE OF STORMS OVER ERN PA CONTINUES TO MOVE EWD LATE THIS
AFTERNOON. HAIL AND DAMAGING WINDS WILL BE THE MAIN THREATS OVER
THESE REGIONS.

[CaptinCrunch]

MESOSCALE DISCUSSION 1206
NWS STORM PREDICTION CENTER NORMAN OK
0400 PM CDT MON JUN 06 2005

AREAS AFFECTED...SRN PA/NRN WV/NRN VA/NRN MD

CONCERNING...SEVERE THUNDERSTORM WATCH 413...416...

VALID 062100Z - 062230Z



SEVERE WEATHER THREAT CONTINUES ACROSS ALL OF WW 413 AND 416. THE
HIGHEST PROBABILITY FOR SEVERE STORMS DURING THE NEXT COUPLE OF
HOURS WILL BE ACROSS SERN PA...NRN VA/WV/MD.

A SQUALL LINE WAS MOVING EWD ACROSS SRN PA AT 30 KT AND WITH
MODERATE INSTABILITY AND A DEVELOPING COLD POOL... WIND DAMAGE IS
LIKELY. AN OUTFLOW BOUNDARY EXTENDS FROM NORTH OF HGR-ILG-TTN LINE.
THIS BOUNDARY WILL ALSO MAINTAIN A FOCUS FOR SEVERE STORMS TO
DEVELOP AND MOVE SLOWLY SEWD ALONG THE LINE.

OTHER SEVERE STORMS ARE ALSO LIKELY AHEAD OF THE COLD FRONT IN SWRN
PA WHERE THE BOUNDARY LAYER HAS WARMED INTO THE MID 80S WITH MID 60
DEWPOINTS.

[TexasStooge]

Code: Select all

   MESOSCALE DISCUSSION 1220
   NWS STORM PREDICTION CENTER NORMAN OK
   0954 AM CDT TUE JUN 07 2005
   
   AREAS AFFECTED...NE IA/SE MN/WRN INTO CNTRL WI
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL
   
   VALID 071454Z - 071700Z
   
   ...POTENTIAL FOR SEVERE TSTMS IS EXPECTED TO INCREASE OVER THE NEXT
   FEW HOURS...AS ONGOING STORMS BECOME SFC BASED WITH THE POSSIBILITY
   OF LARGE HAIL...
   
   A WW MAY BE NEEDED LATER THIS MORNING INTO EARLY AFTERNOON.
   
   SFC WARM FRONT EXTENDS ACROSS SE MN INTO SW WI THIS
   MORNING...GENERALLY NORTH OF A LINE FROM OWATONNA TO WINONA. STORMS
   NOW W OF EAU CLAIRE WI ARE ELEVATED GIVEN WARM LAYER AROUND 850MB
   NOTED ON 12Z MINNEAPOLIS SOUNDING. HOWEVER...FARTHER SOUTH...MORE
   STORMS ARE DEVELOPING WITHIN AN INSTABILITY AXIS...EXTENDING NORTH
   FROM IA. SFC TEMPERATURES HAVE ALREADY RISEN INTO THE MID/UPPER 70S
   ACROSS NE IA AND THE SRN HALF OF WI WITH DEWPOINTS IN THE UPPER 60S
   OR HIGHER. STORMS WHICH RECENTLY AFFECTED THE ROCHESTER MN AREA HAD
   SEVERAL REPORTS OF 1 INCH HAIL...AND THIS ACTIVITY WILL LIKELY
   BECOME SFC BASED WITHIN THE NEXT FEW HOURS. STRONG WARM AIR
   ADVECTION AHEAD OF EJECTING WAVE IN THE NRN HIGH PLAINS SHOULD
   SUPPORT ADDITIONAL DEVELOPMENT.
   
   WHILE STORMS ARE STILL SLIGHTLY ELEVATED...RUC POINT FORECAST
   SOUNDINGS BY 18-19Z SUGGEST THE CAP WILL BE COMPLETELY ERODED ACROSS
   CNTRL/SRN WI.
   
   ..TAYLOR.. 06/07/2005
   
   
   ATTN...WFO...GRB...MKX...DVN...ARX...MPX...DMX...
   
   42139189 42319258 42699285 44059266 45239212 45299130
   45319075 45278966 44938944 44168922 43428933 42968974

[TexasStooge]

Code: Select all

   MESOSCALE DISCUSSION 1219
   NWS STORM PREDICTION CENTER NORMAN OK
   0936 AM CDT TUE JUN 07 2005
   
   AREAS AFFECTED...NERN UT/SWRN WY/NWRN CO
   
   CONCERNING...CONVECTIVE TRENDS
   
   VALID 071436Z - 071600Z
   
   ISOLATED STRONG STORMS WILL BE POSSIBLE INTO THE AFTERNOON FROM NERN
   UT INTO SWRN-SOUTH CENTRAL WY AND NWRN CO.  HAIL...LOCALLY
   APPROACHING AND/OR EXCEEDING SEVERE VALUES...IS EXPECTED TO BE THE
   MAIN THREAT DURING THE MORNING.  AN INCREASED POTENTIAL FOR STRONG
   WIND GUSTS WILL BE AN ADDED THREAT ACROSS SWRN-SRN WY INTO NWRN CO
   DURING THE AFTERNOON.
   
   12Z UPPER AIR ANALYSIS INDICATED VERY COLD MID LEVEL TEMPERATURES
   /-25 C AT EKO/ ASSOCIATED WITH A STRONG SHORT WAVE TROUGH OVER NRN
   UT AT 14Z.  DESPITE MARGINAL INSTABILITY INDICATED ON THE 12Z SLC
   SOUNDING...THE COLD MID LEVEL TEMPERATURES AND SUFFICIENT EFFECTIVE
   DEEP LAYER SHEAR RESULTED IN A FEW SEVERE HAIL REPORTS.  VIS IMAGERY
   SHOWED CLEAR SKIES DOWNSTREAM OF THE MID LEVEL SHORT WAVE TROUGH AND
   700 MB THERMAL BOUNDARY.  THIS WILL ALLOW FOR STRONG SURFACE HEATING
   AND THE DEVELOPMENT OF VERY STEEP LOW LEVEL LAPSE RATES THIS
   AFTERNOON.  INSTABILITY IS EXPECTED TO REMAIN MARGINAL INTO SWRN WY/
   NWRN CO TODAY. HOWEVER...STRONG LARGE SCALE ASCENT AHEAD OF THE MID
   LEVEL TROUGH AND EXIT REGION OF A 55 KT WSWLY MID LEVEL JET NOSING
   INTO NWRN CO/SRN WY THIS AFTERNOON SHOULD SUPPORT A FEW
   THUNDERSTORMS. THE COLD MID LEVEL TEMPERATURES MAY SUPPORT
   LOCALIZED HAIL WITH THE STRONGEST ACTIVITY...WHILE VERY STEEP LOW
   LEVEL LAPSE RATES SHOULD AID IN THE POTENTIAL FOR ISOLATED STRONG
   WIND GUSTS.
   
   ..PETERS.. 06/07/2005
   
   
   ATTN...WFO...CYS...RIW...GJT...SLC...PIH...
   
   40591136 43061134 43300934 43150748 42000678 41270671
   40660719 39520944 39581114

[CaptinCrunch]

MESOSCALE DISCUSSION 1239
NWS STORM PREDICTION CENTER NORMAN OK
0855 AM CDT WED JUN 08 2005

AREAS AFFECTED...WRN-CENTRAL MO/ERN KS/SRN IA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 081355Z - 081500Z



WW MAY BE REQUIRED ACROSS MUCH OF WRN-CENTRAL MO INTO ERN KS AND SRN
IA.

WV IMAGERY/OBJECTIVE ANALYSIS DATA INDICATED A SHORT WAVE TROUGH
OVER THE ERN DAKOTAS TO THE KS/NEB BORDER. REGIONAL RADARS/
LIGHTNING DATA INDICATED THUNDERSTORMS INCREASING IN COVERAGE/
INTENSITY ACROSS NWRN MO...WITH CONTINUED DEVELOPMENT IN SWRN IA
ALONG THE SRN EXTENT OF MCS MOVING ACROSS UPPER MS VALLEY ATTM. VIS
IMAGERY SHOWED TCU DEVELOPING RAPIDLY SWWD INTO EAST CENTRAL KS.

12Z SOUNDINGS FROM THE SRN/CENTRAL PLAINS INTO LOWER MO VALLEY
SUGGEST THE NEW STORMS AND TCU ARE DEVELOPING WITHIN A VERY STRONG
INSTABILITY AXIS. THE AIR MASS CAPPED ATTM...BUT STRONG SURFACE
HEATING ACROSS ERN KS INTO MUCH OF MO/SRN IA AND WRN IL WILL WEAKEN
THIS CAP AS INDICATED BY CURRENT OBJECTIVE ANALYSES OF CINH AROUND
-100 J/KG. ALTHOUGH DEEP LAYER SHEAR IS NOT STRONG ATTM...THE VERY
UNSTABLE AIR MASS BEING FED INTO THIS REGION PER 40-50 KT SWLY LLJ
WILL CONTINUE TO COMPENSATE FOR THE SHEAR TO SUPPORT A THREAT FOR
STRONG TO SEVERE STORMS. THE NAM/RUC INDICATE THIS LLJ WILL WEAKEN
THIS MORNING TO 20-25 KT. HOWEVER...THESE SPEEDS COMBINED WITH
LARGE SCALE ASCENT AHEAD OF MID/UPPER LEVEL TROUGH AND VERY UNSTABLE
AIR MASS ARE EXPECTED TO SUPPORT CONTINUATION OF THUNDERSTORM
DEVELOPMENT INTO THE AFTERNOON. AS CAP WEAKENS...PRIND SUGGEST
THERE WILL BE AN INCREASING THREAT FOR SEVERE STORMS WITH LARGE HAIL
AND DAMAGING WINDS.

[CaptinCrunch]

MESOSCALE DISCUSSION 1240
NWS STORM PREDICTION CENTER NORMAN OK
0947 AM CDT WED JUN 08 2005

AREAS AFFECTED...PORTIONS OF SRN IA AND NRN MO

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 081447Z - 081515Z



WW WILL BE ISSUED SOON FOR PORTIONS OF SRN IA AND NRN MO.

THUNDERSTORMS CONTINUE TO DEVELOP ALONG SRN/SWRN PORTION OF MCS
MOVING ACROSS UPPER MS VALLEY. STRONG WELL DEFINED COLD POOL WITH
THIS ACTIVITY SUGGESTS PROPAGATION WILL CONTINUE TO THE ESE WITH NEW
DEVELOPMENT ACROSS SRN IA/NRN MO. DESPITE MARGINAL DEEP LAYER
SHEAR...WEAKENING CAP WITH ADDITIONAL SURFACE HEATING AND THE
DEVELOPMENT OF A VERY UNSTABLE AIR MASS WILL SUPPORT DAMAGING WINDS
AND HAIL WILL AS THE PRIMARY THREATS.

[CaptinCrunch]

MESOSCALE DISCUSSION 1243
NWS STORM PREDICTION CENTER NORMAN OK
0102 PM CDT WED JUN 08 2005

AREAS AFFECTED...CENTRAL/SRN LA...CENTRAL/SRN MS

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 081802Z - 082000Z



STORMS SHOULD CONTINUE TO DEVELOP AND STRENGTHEN OVER THE AREA
THROUGH THE AFTERNOON. SOME OF THE STRONGEST STORMS WILL BE CAPABLE
OF PRODUCING MARGINALLY SVR HAIL AND DAMAGING WINDS. OVERALL THREAT
APPEARS TO BE LIMITED ENOUGH THAT A WW IS NOT ANTICIPATED.

12Z UA ANALYSIS AND SATELLITE IMAGERY REVEAL AN MCV WITH COLD MID
LEVEL TEMPERATURES ASSOCIATED WITH IT /- 10 TO -11 DEG C AT 500 MB/
LOCATED OVER SWRN LA. AHEAD OF THIS FEATURE...A SFC BOUNDARY AND
VERY WARM/UNSTABLE AIRMASS WITH MUCAPES APPROACHING 3000 J/KG HAS
ALREADY AIDED IN STRONG CONVECTIVE DEVELOPMENT OVER PORTIONS OF
SWRN/WCENTRAL MS. ADDITIONAL STRONG CONVECTIVE DEVELOPMENT IS
ANTICIPATED TO OCCUR IN ASSOCIATION WITH THE MCV OVER PORTIONS OF
SRN/CENTRAL AND ERN LA DURING THE NEXT 1-3 HRS. DESPITE VERY WARM
LOWER TROPOSPHERIC TEMPERATURES AND HIGH DWPTS...MODERATELY STEEP
MID LEVEL LAPSE RATES DUE TO THE PRESENCE OF COLD MID LEVEL
TEMPERATURES WILL SUPPORT THE THREAT FOR SOME MARGINALLY SVR HAIL
WITH THE STRONGEST STORMS. IN ADDITION...THE PRESENCE OF DRY AIR IN
THE LOW-MID LEVELS ABOVE THE BOUNDARY LAYER AS EVIDENT BY THE 12Z
JAN AND LIX SOUNDINGS MAY BE SUFFICIENT FOR A DAMAGING WIND THREAT
ESPECIALLY IF COLD POOL DEVELOPMENT/STORM MERGERS OCCUR.

[CaptinCrunch]

MESOSCALE DISCUSSION 1245
NWS STORM PREDICTION CENTER NORMAN OK
0152 PM CDT WED JUN 08 2005

AREAS AFFECTED...MUCH OF IL INTO EAST CENTRAL MO

CONCERNING...SEVERE THUNDERSTORM WATCH 436...

VALID 081852Z - 081915Z



NEW WW WILL BE ISSUED SOON TO LIKELY REPLACE WW 436.

WELL DEFINED COLD POOL WITH LEADING EDGE BOW ECHO CONTINUES TO MOVE
ESE INTO IL AND NERN-ERN MO ATTM. ADDITIONAL STORMS HAVE DEVELOPED
ALONG A SURFACE BOUNDARY WHICH EXTENDED FROM THE NRN PART OF THE BOW
CURRENTLY LOCATED OVER MERCER COUNTY IL...AND NEWD TO FAR SERN WI.
DAMAGING WIND THREAT WILL CONTINUE TO BE THE PRIMARY THREAT AS THIS
BOW MOVES ESEWD INTO A MODERATELY UNSTABLE AIR MASS ACROSS IL INTO
ERN MO. AN ISOLATED TORNADO THREAT WILL BE POSSIBLE MAINLY AT THE
INTERSECTION OF THE SURFACE TROUGH AND BOW ECHO...WHERE LOW LEVEL
SHEAR VALUES WILL BE ENHANCED.

[CaptinCrunch]

MESOSCALE DISCUSSION 1246
NWS STORM PREDICTION CENTER NORMAN OK
0222 PM CDT WED JUN 08 2005

AREAS AFFECTED...NERN/ECENTRAL NY...SRN VT/SRN NH AND NWRN MA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 081922Z - 082115Z



ISOLATED LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE WITH
CONVECTION DEVELOPING OVER NRN NY AS IT MOVES ESEWD INTO SRN VT/NH
AND ECENTRAL NY. OVERALL THREAT APPEARS TO BE MARGINAL ENOUGH THAT A
WW IS NOT ANTICIPATED ATTM.

LATEST OBJECTIVE ANALYSIS SHOWS AIRMASS DOWNSTREAM OF DEVELOPING
CONVECTION AND SOUTH OF FRONTAL BOUNDARY DRAPED ACROSS NRN NY WAS
MODERATELY UNSTABLE WITH MUCAPES AROUND 2000 J/KG. AREA REMAINS ON
THE SRN FRINGES OF STRONGER MID LEVEL FLOW ASSOCIATED WITH SHORTWAVE
TROUGH MOVING ACROSS QUEBEC PROVINCE CANADA. UNIDIRECTIONAL WIND
PROFILES FAVORS LINEAR CONVECTIVE MODE WITH THE POTENTIAL FOR
DAMAGING WINDS IN THE STRONGEST STORMS. DEEP LAYER SHEAR VALUES
AROUND 30 KTS MAY ALLOW FOR MARGINALLY SVR HAIL GIVEN AMT OF
INSTABILITY. LIMITED WIND STRENGTH /AOB 20 KTS/ IN THE 850-700 MB
LAYER SHOULD PRECLUDE A GREATER ORGANIZED WIND THREAT.

[CaptinCrunch]

MESOSCALE DISCUSSION 1247
NWS STORM PREDICTION CENTER NORMAN OK
0258 PM CDT WED JUN 08 2005

AREAS AFFECTED...MUCH OF LOWER MI

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 081958Z - 082200Z



ISOLATED SVR STORMS WILL CONTINUE TO BE POSSIBLE OVER NRN LOWER MI.
ADDITIONAL ISOLATED SVR STORMS MAY DEVELOP OVER CENTRAL LOWER MI IN
THE NEXT 1-2 HOURS.

CLUSTER OF STRONGER STORMS OVER NCENTRAL LOWER MI HAS SHOWN SIGNS OF
BEING IN A WEAKLY SHEARED ENVIRONMENT WITH PULSE TYPE NATURE
OBSERVED WHILE CONVECTION IS BEING UNDERCUT BY LAKE BREEZE FRONT.
VIS SAT IMAGERY SUGGESTS THAT ADDITIONAL CONVECTION MAY BEGIN TO
DEVELOPING ALONG CONVERGENCE ZONE EXTENDING N-S OVER WRN LOWER MI IN
THE NEXT 1-2 HRS. IN THE SHORT TERM /NEXT 1-2 HOURS/...WEAK MID
LEVEL FLOW...AS EVIDENT BY 18Z DTX SOUNDING WILL LIKELY MITIGATE A
GREATER SVR WIND/HAIL THREAT WITH CONVECTION OVER CENTRAL/NRN LOWER
MI. HOWEVER...RECENT TRENDS IN THE GRB VWP SUGGESTS THAT MID LEVEL
FLOW HAS INCREASED TO OVER 40 KTS IN ASSOCIATION WITH MCV MOVING EWD
OVER ERN WI. AS THIS FEATURE CONTINUES TO MOVE EWD INTO NRN/CENTRAL
LOWER MI THIS AFTERNOON...TRENDS WILL CONTINUED TO BE MONITORED FOR
AN INCREASING ORGANIZED SVR THREAT AND POSSIBLE WW GIVEN A
MODERATELY UNSTABLE AIRMASS IN PLACE OVER THE REGION WITH MUCAPES
AROUND 3000 J/KG OVER MUCH OF LOWER MI.

[CaptinCrunch]

MESOSCALE DISCUSSION 1248
NWS STORM PREDICTION CENTER NORMAN OK
0349 PM CDT WED JUN 08 2005

AREAS AFFECTED...FAR NERN ND...NWRN AND NCENTRAL MN

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 082049Z - 082245Z



ISOLATED SVR STORMS CAPABLE OF PRODUCING LARGE HAIL MAY DEVELOP FROM
NW-SE ACROSS THE AREA THROUGH THE REMAINDER OF THE AFTERNOON.

20Z SFC ANALYSIS SHOWS A SFC LOW OVER FAR NERN ND TO THE NW OF GFK.
A SFC TROUGH EXTENDS SEWD FROM THE LOW INTO WCENTRAL/SWRN MN. WEST
OF THIS TROUGH...DEWPTS HAVE FALLEN INTO THE 50S. ATTM...ENOUGH CINH
REMAINS OVER MOST OF THE AREA LIMITING STORM DEVELOPMENT TO PORTIONS
OF NERN ND WHERE CONVERGENCE IS STRONGEST. HOWEVER...THE AIRMASS
OVER NWRN/NCENTRAL MN SHOULD CONTINUE TO WARM INTO THE MID 70S WITH
DEWPTS SLOWLY RISING INTO THE LOWER 60S. THIS WILL LEAD TO AN
ENVIRONMENT OF MUCAPES AROUND 1000-1500 J/KG AND LITTLE REMAINING
CINH. STRONG MID LEVEL WIND MAX WILL MOVE OVER THE AREA THROUGH THE
AFTERNOON SUPPORTIVE OF ENOUGH SHEAR THAT LOW TOPPED SUPERCELLS
CAPABLE OF PRODUCING MARGINALLY SVR HAIL WILL BE POSSIBLE. MAIN
LIMITING FACTOR FOR A WW WILL BE THE MARGINAL INSTABILITY AND MID
LEVEL WARMING GRADUALLY OVERSPREADING THE INSTABILITY AXIS OVER NRN
AND CENTRAL MN THROUGH THE AFTERNOON IN THE WAKE OF A SHORTWAVE
TROUGH. THIS WOULD TEND TO LIMIT UPDRAFT STRENGTH DESPITE STRONG
SHEAR PROFILES.

[CaptinCrunch]

MESOSCALE DISCUSSION 1249
NWS STORM PREDICTION CENTER NORMAN OK
0400 PM CDT WED JUN 08 2005

AREAS AFFECTED...ERN KS/WRN-CENTRAL MO

CONCERNING...TORNADO WATCH 437...

VALID 082100Z - 082200Z



PARAMETERS REMAIN FAVORABLE FOR VERY LARGE HAIL...TORNADOES AND
DAMAGING WINDS ACROSS MUCH OF WW 437. SURFACE HEATING HAS CONTINUED
WITHIN A VERY MOIST AIR MASS /SURFACE DEWPOINTS IN THE MID-UPPER
70S/ RESULTING IN AN EXTREMELY UNSTABLE AIR MASS /MLCAPE VALUES OF
4000-5000 J/KG. REGIONAL RADARS/VIS IMAGERY INDICATED TCU
DEVELOPING ALONG A LOW LEVEL CONVERGENCE BOUNDARY AHEAD OF THE COLD
FRONT...WITH THIS CLOUD DEVELOPMENT AT THE PRESENT TIME BETWEEN
EMP-STJ. DEEP LAYER AND LOW LEVEL SHEAR PER MODIFIED OLATHE KANSAS
WIND PROFILER FOR CURRENT OJC SURFACE WIND HAVE BECOME FAVORABLE FOR
ROTATING STORMS AND A HEIGHTENED POTENTIAL FOR A TORNADO...GIVEN
/SFC-6 KM SHEAR AT 32 KT AND 0-3 KM SRH AROUND 150 M2/S2.

THREAT FOR DAMAGING WINDS AND HAIL WILL REMAIN LIKELY WITH STORMS
OVER THE ERN PORTION OF WW 437 AS WELL ESTABLISHED COLD POOL IN WAKE
OF E-W ORIENTED SQUALL LINE OVER CENTRAL MO MOVES SWD. SURFACE
TEMPERATURE GRADIENT BETWEEN COLD POOL AND PRE-CONVECTIVE AIR MASS
RANGES FROM 25-30 DEGREES. STORMS WILL CONTINUE TO DEVELOP ACROSS
ERN PORTION OF WW THIS AFTERNOON...AS SQUALL LINE MOVES INTO VERY
UNSTABLE AIR MASS /MLCAPE 2500-4000 J/KG/.

[CaptinCrunch]

MESOSCALE DISCUSSION 1250
NWS STORM PREDICTION CENTER NORMAN OK
0412 PM CDT WED JUN 08 2005

AREAS AFFECTED...ERN/SRN IL AND PORTIONS OF ERN MO

CONCERNING...SEVERE THUNDERSTORM WATCH 438...

VALID 082112Z - 082315Z



WELL DEFINED COLD POOL EVIDENT OVER WCENTRAL IL/NERN MO WILL SUPPORT
CONTINUED SEWD PROPAGATION OF CONVECTIVE LINE THROUGH MUCH OF WW 438
THROUGH THE AFTERNOON. THE SVR THREAT WILL CONTINUE OVER PORTIONS OF
NERN/ECENTRAL IL...HOWEVER CURRENT TRENDS SUGGEST THAT THE SVR
THREAT IN THIS AREA MAY BE WANING.

LATEST RADAR IMAGERY SHOWS A GUST FRONT MOVING SEWD AT 35 KTS ACROSS
ECENTRAL MO/WCENTRAL IL NEAR THE STL METRO AREA. NEW DEVELOPMENT
ALONG THIS GUST FRONT WILL SUPPORT A CONTINUED SVR THREAT WITH
FORWARD PROPAGATING MCS ACROSS THE STL METRO AREA AND INTO SRN
PORTIONS OF WW 438 OVER THE NEXT 1-2 HRS. GIVEN CURRENT TRENDS AND
STRENGTH OF LINE...A NEW WW OVER SERN MO/SRN IL MAY BE NEEDED IN THE
NEXT 1-2 HOURS. FARTHER NORTH...THE GUST FRONT WAS SURGING EAST OF
CONVECTION OVER ERN IL. IF CURRENT TRENDS CONTINUE...SVR THREAT
WOULD LIKELY BE MITIGATED OVER THIS REGION BEFORE 00Z.

[CaptinCrunch]

MESOSCALE DISCUSSION 1258
NWS STORM PREDICTION CENTER NORMAN OK
0115 PM CDT THU JUN 09 2005

AREAS AFFECTED...MUCH OF NRN/CENTRAL NY...VT/NH AND WRN ME

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 091815Z - 092015Z



TSTMS DEVELOPING OVER THE AREA POSES A THREAT FOR ISOLATED LARGE
HAIL/DAMAGING WINDS IN THE NEXT FEW HOURS. OVERALL RISK APPEARS TO
BE MARGINAL ENOUGH THAT A WW IS NOT ANTICIPATED ATTM.

FCST SOUNDINGS AND OBJECTIVE ANALYSIS OVER THE AREA SUGGESTS THAT
MUCAPES WERE FROM 2000-3000 J/KG OVER THE REGION. TSTMS HAVE
RECENTLY DEVELOPED ALONG A E-W ORIENTED BOUNDARY EXTENDING FROM ERN
ONTARIO EWD ACROSS NRN NY...NRN VT/NRN NH INTO SWRN ME. AN UPPER
WAVE EVIDENT ON WV IMAGERY OVER ERN ONTARIO WILL CONTINUE TO MOVE
EWD OVER THE RIDGE AND ACROSS NRN NEW ENGLAND THIS AFTERNOON. THIS
FEATURE SHOULD SUPPORT ADDITIONAL TSTM DEVELOPMENT OVER THE
REGION...ESPECIALLY ALONG AFOREMENTIONED E-W ORIENTED BOUNDARY. MID
LEVEL FLOW WILL REMAIN RELATIVELY WEAK /AOB 30 KTS/ THUS...GIVEN
VEERED LOW LEVEL FLOW...OVERALL DEEP LAYER SHEAR WILL BE SUPPORTIVE
OF MOSTLY MULTICELLULAR TYPE STORM STRUCTURES. HOWEVER...GIVEN THE
AMT OF INSTABILITY OVER THE AREA...BRIEF SUPERCELLULAR TYPE
STRUCTURES MAY BE POSSIBLE WITH AN ISOLATED LARGE HAIL THREAT.
UNIDIRECTIONAL SHEAR PROFILES FURTHER SUPPORT CONVECTION EVENTUALLY
BECOMING LINEAR WITH THE POTENTIAL FOR ISOLATED DAMAGING WINDS.
CONVECTION SHOULD MOVE ESEWD AROUND 20 KTS...WITH SLIGHTLY FASTER
MOTIONS WITHIN INDIVIDUAL LINE SEGMENTS.