SPC MCD 092047
COZ000-092300-

SPC MESOSCALE DISCUSSION 1638 FOR E CNTRL CO
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE NEXT COUPLE HOURS
OVER THE PALMER DIVIDE AND INTENSIFY AS THEY SPREAD EWD. LARGE HAIL
AND DAMAGING WIND GUSTS WILL BE THE PRIMARY THREATS. THIS AREA WILL
CONTINUE TO BE MONITORED...AND A WW MIGHT BE NEEDED WITHIN THE NEXT
1-2 HOURS.

VISIBLE IMAGERY SHOWS CONVECTION DEVELOPING OVER E CNTRL CO ALONG
THE PALMER DIVIDE. LIMITED LIGHTNING WITH THIS ACTIVITY SUGGESTS
THE CONVECTION IS STILL RATHER SHALLOW. WV IMAGERY SHOWS VORT MAX
ROUNDING BASE OF UPPER TROUGH MOVING INTO NWRN CO. AS LARGE SCALE
ASCENT FROM THIS FEATURE APPROACHES CNTRL CO...MID LEVEL
THERMODYNAMIC PROFILES SHOULD MOISTEN AND SUPPORT DEEPER CONVECTION
OVER THE HIGHER TERRAIN. A BAND OF 45 TO 50 KT MID LEVEL FLOW
ACCOMPANYING THE UPPER TROUGH SHOULD HELP STORMS MOVE EWD OFF THE
MOUNTAINS INTO THE HIGH PLAINS WHERE RICHER LOW LEVEL MOISTURE/
MODERATE INSTABILITY WILL SUPPORT INTENSIFICATION. THOUGH LOW LEVEL
FLOW IS RATHER WEAK...STRONG DEEP LAYER SHEAR WILL CONTRIBUTE TO
SUPERCELL STORMS CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WIND
GUSTS. ACTIVITY MAY CONSOLIDATE INTO AN MCS AS IT MOVES INTO ERN
CO/WRN KS LATER THIS EVENING WHERE IT WILL ENCOUNTER INCREASING
MOIST INFLOW FROM SLY LOW LEVEL JET.


..DIAL.. 08/09/02

...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
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ZCZC SPCSWOMCD ALL;
ACUS11 KWNS 092053
SPC MCD 092053
KSZ000-OKZ000-TXZ000-092300-

SPC MESOSCALE DISCUSSION 1639 FOR S/SW KS...NW OK/OK
PANHANDLE...NRN TX PANHANDLE
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

ISOLATED LARGE HAIL AND STRONG DOWNBURST WINDS ARE POSSIBLE THE
NEXT FEW HOURS. AREA WILL CONTINUE TO BE MONITORED.
THUNDERSTORMS HAVE COALESCED ALONG AN OUTFLOW BOUNDARY THAT IS
MOVING SLOWLY SWD FROM SW KS INTO THE OK PANHANDLE AND EXTREME NW
OK. SURFACE TEMPERATURES HAVE WARMED TO THE MID-UPPER 90S S OF
THIS BOUNDARY...RESULTING IN MLCAPE VALUES NEAR 2500 J/KG AND
TEMPERATURE-DEW POINT SPREADS OF 30-40 F. IN ADDITION...THE ELY
FLOW N OF THE BOUNDARY IS CONTRIBUTING TO LOW-LEVEL AND DEEP LAYER
SHEAR THAT IS SUFFICIENT FOR SUPERCELLS...THOUGH THE RAIN-COOLED
AIR MASS HAS LIMITED INTENSITY OF STORMS N OF THE OUTFLOW. A FEW
OF THE STORMS MAY PRODUCE ISOLATED DAMAGING DOWNBURST WINDS...AND
PERHAPS MARGINALLY SEVERE HAIL...THE NEXT FEW HOURS AS STORMS
DEVELOP SWD INTO THE STRONGER INSTABILITY OVER NW OK AND THE NE TX
PANHANDLE.


..THOMPSON.. 08/09/02

...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
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ZCZC SPCSWOMCD ALL
ACUS11 KWNS 092146
SPC MCD 092146
NEZ000-100000-

SPC MESOSCALE DISCUSSION 1640 FOR CNTRL/SRN NEB
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

TRENDS ARE BEING MONITORED FOR POSSIBILITY OF INCREASING SEVERE
THREAT WHICH COULD REQUIRE A WW.

SLOW DESTABILIZATION IS ONGOING ALONG WEAK SURFACE FRONT ACROSS
CENTRAL NEBRASKA. BOUNDARY EXTENDS SOUTHWARD FROM A WEAK SURFACE
LOW...WEST OF MITCHELL SD...THROUGH THE NORTH PLATTE AREA INTO
NORTHWEST KANSAS. AIR MASS IS MOIST WITH DEW POINTS IN THE
MID/UPPER 60S...BUT SURFACE HEATING HAS BEEN FAIRLY LIMITED.
HOWEVER...LATEST SATELLITE IMAGERY INDICATES UPSTREAM SHORT WAVE
TROUGH IS BEGINNING TO PIVOT EASTWARD/NORTHEASTWARD OUT OF THE
CENTRAL ROCKIES...AND THIS WILL BE ACCOMPANIED BY WEAK MID-LEVEL
COOLING AND STRENGTHENING FORCING FOR UPWARD VERTICAL MOTION ALONG
FRONT NEXT FEW HOURS. MID-LEVEL CAP INHIBITING ONGOING WEAK
CONVECTIVE DEVELOPMENT ALONG FRONT WILL LIKELY WEAKEN SUFFICIENTLY
FOR INTENSIFYING THUNDERSTORMS...WITH VERTICAL SHEAR PROFILES
BECOMING FAVORABLE FOR SUPERCELLS. GREATEST RISK FOR THIS APPEARS
TO BE WEST/SOUTHWEST OF GRAND ISLAND BY/SHORTLY AFTER 10/00Z...AS
BASE OF APPROACHING SHORT WAVE SHIFTS ACROSS SOUTH CENTRAL
NEBRASKA.


..KERR.. 08/09/02

...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
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ZCZC SPCSWOMCD ALL;
ACUS11 KWNS 092207
SPC MCD 092207 COR
SDZ000-MNZ000-100100-

...CORRECTED EXPIRATION TIME...

SPC MESOSCALE DISCUSSION 1641 FOR ERN SD NWD INTO NWRN MN
CONCERNING...SEVERE THUNDERSTORM POTENTIAL...

THUNDERSTORMS OVER CENTRAL/ERN SD ARE EXPECTED TO GRADUALLY
INTENSIFY AND BECOME MORE SURFACE BASED WITH TIME THROUGH THE EARLY
EVENING AS THEY MOVE NEWD INTO WRN/NRN MN. A WW MAY BE NEEDED FOR
PORTIONS OF WRN AND NRN MN IN THE NEXT COUPLE OF HOURS.
RECENT WV SATELLITE IMAGERY SHOWS THAT MID LEVEL SHORTWAVE TROUGH
AXIS IS BECOMING NEGATIVE TILTED OVER THE NRN HI PLAINS. IN
RESPONSE TO THIS...MID LEVEL SSWLY FLOW HAS STRENGTHENED OVER
SRN/ERN PORTIONS OF THE TROUGH OVER NRN NEB/ERN SD...AS NOTED BY
RECENT PROFILER DATA AT MERRIMAN NEB AND VWP FROM ABERDEEN. RECENT
TRENDS IN VISIBLE SATELLITE DATA SUGGEST THAT THE BOUNDARY LAYER
REMAINS SOMEWHAT CAPPED PER MODIFIED 12Z ABR SOUNDING.
HOWEVER...ISOLATED NEW CONVECTIVE DEVELOPMENT HAS BEGUN ACROSS
AURORA AND BRULE COUNTIES IN SCENTRAL SD AND CLARK COUNTY IN
ECENTRAL SD. THIS CONVECTION WAS DEVELOPING WHERE LOW LEVEL
CONVERGENCE HAS BECOME MAXIMIZED AT THE INTERSECTION OF A NWWD
MOVING OUTFLOW BOUNDARY AND THE SYNOPTIC FRONTAL BOUNDARY. THE
COMBINATION OF INCREASING MID LEVEL COLD ADVECTION ALONG WITH
ADDITIONAL DESTABILIZATION OVER ERN SD/FAR SERN ND AND WRN MN
SHOULD AID IN FURTHER SURFACE BASED CONVECTIVE DEVELOPMENT ALONG
THE FRONTAL BOUNDARY FROM SFD NEWD TO NEAR FAR OVER THE NEXT FEW
HOURS. DESPITE THE OVERALL LIMITED NATURE OF AVAILABLE AND FORECAST
INSTABILITY...1000-1500 J/KG OF MUCAPE...STRENGTH OF MID LEVEL
WINDS FIELDS /35 TO 45 KTS AT 500 MB/ SUGGESTS THAT WEAK TO
MODERATELY ORGANIZED BOW ECHOES AND/OR LEWPS WILL BE THE PRIMARY
CONVECTIVE MODE...WITH DAMAGING WINDS THE MAIN SEVERE THREAT.

..CROSBIE.. 08/09/02

...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
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ZCZC SPCSWOMCD ALL
ACUS11 KWNS 092326
SPC MCD 092326
COZ000-KSZ000-OKZ000-TXZ000-100200-

SPC MESOSCALE DISCUSSION 1642 FOR SE CO
CONCERNING...SEVERE THUNDERSTORM WATCH 587...

ISOLATED SUPERCELLS CONTINUE TO DEVELOP SOUTHEASTWARD ACROSS EAST
CENTRAL COLORADO...AWAY FROM THE FRONT RANGE...WHILE NEW CONVECTIVE
DEVELOPMENT CONTINUES TO ALONG FRONT RANGE...NORTH OF PUEBLO.
ACTIVITY IS DEVELOPING ALONG/NORTH OF OUTFLOW ENHANCED SURFACE
FRONT...SLOWLY ADVANCING SOUTHWARD INTO SOUTHEAST COLORADO. THIS
BOUNDARY APPEARS LIKELY TO INTERSECT ANOTHER WESTWARD PROPAGATING
OUTFLOW BOUNDARY VICINITY OF KIOWA COUNTY WITHIN NEXT FEW
HOURS...SUPPORTING INTENSIFYING NEW CONVECTIVE DEVELOPMENT.
AS RADIATIONAL COOLING COMMENCES...30 TO 40 KT SOUTHERLY LOW-LEVEL
JET IS EXPECTED TO DEVELOP ABOVE NEAR SURFACE INVERSION ACROSS THE
SOUTH CENTRAL HIGH PLAINS...AND MAY HELP FOCUS FORCING FOR GROWING
CONVECTIVE CLUSTER ACROSS SOUTHEAST COLORADO DURING THE NEXT 2 TO
3 HOURS.


..KERR.. 08/09/02

...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
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ZCZC SPCSWOMCD ALL
ACUS11 KWNS 100027
SPC MCD 100027
SDZ000-MNZ000-100200-

SPC MESOSCALE DISCUSSION 1643 FOR ERN SD AND WRN/NRN MN
CONCERNING...SEVERE THUNDERSTORM WATCH 588 AND SEVERE THUNDERSTORM

POTENTIAL...
SEVERE THREAT WILL CONTINUE ACROSS MAINLY THE ERN PORTION OF WW 588
OVER THE NEXT FEW HOURS. ADDITIONAL ISOLATED SEVERE THUNDERSTORMS
ARE POSSIBLE ACROSS NRN MN OVER THE NEXT FEW HOURS. WE WILL
CONTINUE TO MONITOR THIS AREA FOR POSSIBLE ADDITIONAL WW.
THUNDERSTORM THAT HAS EXHIBITED BOTH SUPERCELL AND BOW ECHO
CHARACTERISTICS ACROSS CHARLES MIX AND WRN BON HOMME COUNTY WILL
CONTINUE TO MOVE EWD AROUND 35 KTS AND POSE A THREAT FOR LARGE HAIL
AND DAMAGING WINDS ACROSS THE REMAINDER OF BON HOMME...YANKTON AND
CLAY COUNTIES THROUGH 10/02Z. STRONG 700-500 MB SWLY WIND FIELDS
NOTED ON ABR VWP AND 00Z SOUNDING SHOULD AID IN INCREASING FORWARD
STORM MOTIONS AND AN POSSIBLY GREATER THREAT FOR DAMAGING WIND
GUSTS WITH CONVECTION OVER FAR NERN SD AND ADJACENT AREAS OF
WCENTRAL MN. DEVELOPING CONVECTION OVER NCENTRAL/NWRN MN ALONG
PREFRONTAL TROUGH WILL CONTINUE TO BE SUPPORTED BY LARGE SCALE
DIFFLUENT MID/UPPER LEVEL FLOW. MUCAPE VALUES FROM 1500 TO 2000
J/KG PER RECENT FORECAST SOUNDINGS WOULD SUPPORT ADDITIONAL
INTENSIFICATION OF THIS CONVECTION. HOWEVER...MEAGER MID LEVEL
WINDS AROUND 25-30 KTS PER RUC MODEL ANALYSIS FIELD ALONG WITH
UNIDIRECTIONAL NATURE OF WINDS MAY LIMIT THE OVERALL ORGANIZED
SEVERE THREAT OVER THIS AREA FOR THE NEXT 1-2 HOURS UNTIL STRONGER
MID LEVEL FLOW OVER NERN SD MOVES INTO THE AREA. WE WILL CONTINUE
TO MONITOR TRENDS AND POTENTIAL FURTHER ORGANIZATION FOR AN
ADDITIONAL WW OVER PORTIONS OF NRN MN.


..CROSBIE.. 08/09/02

...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
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ZCZC SPCSWOMCD ALL
ACUS11 KWNS 100155
SPC MCD 100155
COZ000-KSZ000-TXZ000-OKZ000-NMZ000-100400-

SPC MESOSCALE DISCUSSION 1644 FOR SE CO...SW KS...PARTS TX/OK
PNHDLS
CONCERNING...SEVERE THUNDERSTORM WATCH 587...

CURRENT TRENDS SUGGEST NEW WW MAY NOT BE NEEDED.

EXPANDING CLUSTER OF THUNDERSTORMS STILL APPEARS LIKELY NEXT FEW
HOURS ACROSS PARTS OF SOUTHEAST COLORADO/SOUTHWEST KANSAS...WHERE
CONVERGENCE/WARM ADVECTION ARE BECOMING FOCUSED ON NOSE OF
STRENGTHENING SOUTHERLY LOW-LEVEL JET. VEERING MID-LEVEL FLOW IN
WAKE OF MID-LEVEL TROUGH AXIS SHIFTING ACROSS THE NORTHERN PLAINS
WILL ENHANCE VERTICAL SHEAR PROFILES...AND MAY SUPPORT CONTINUING
THREAT FOR HAIL BEYOND CURRENT WW EXPIRATION TIME. HOWEVER...
DAMAGING WIND THREAT APPEARS TO BE DIMINISHING AS ACTIVITY DEVELOPS
SOUTHEASTWARD INTO COOLER/MORE MOIST BOUNDARY LAYER AFFECTED BY
PRIOR CONVECTIVE ACTIVITY. STRONGEST STORMS WILL CONTINUE TO
DEVELOP SOUTH SOUTHWESTWARD ALONG LOW-LEVEL JET AXIS INTO THE TEXAS
PANHANDLE...POSSIBLY NORTHEAST NEW MEXICO...THROUGH THE LATE
EVENING HOURS.


..KERR.. 08/10/02

...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
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ZCZC SPCSWOMCD ALL
ACUS11 KWNS 100240
SPC MCD 100240
SDZ000-MNZ000-100400-

SPC MESOSCALE DISCUSSION 1645 FOR SERN SD AND WCENTRAL/SWRN MN
CONCERNING...SEVERE THUNDERSTORM WATCH 588...

SEVERE THREAT CONTINUES TO DIMINISH OVER THE REMAINING VALID
PORTION OF WW 588. ISOLATED SEVERE STORMS CAPABLE OF PRODUCING
MARGINALLY SEVERE HAIL WILL CONTINUE TO BE POSSIBLE FROM SERN SD
ENEWD INTO NWRN IA...SWRN/WCENTRAL MN OVER THE NEXT SEVERAL HOURS.
HOWEVER...OVERALL THREAT WILL BE SMALL ENOUGH TO ALLOW WW TO EXPIRE
AT 10/04Z.

PRECIPITATION CONTINUES TO OVERSPREAD MUCH OF THE ERN HALF OF WW
588...ENDING THE THREAT FOR SURFACE BASED CONVECTION. RECENT TRENDS
IN WV SAT IMAGERY INDICATED PRONOUNCED MID/UPPER LEVEL DRYING ALONG
SHORTWAVE TROUGH AXIS OVER CENTRAL/SCENTRAL SD. RECENT RADAR TRENDS
INDICATE THAT STEEPER MID LEVEL LAPSE RATES MAY BE REMATERIALIZING
THEMSELVES ON THE BACK SIDE OF STRATIFORM PRECIPITATION AREA...AND
JUST AHEAD OF THE SHORTWAVE TROUGH AXIS AIDING IN RENEWED UPDRAFT
STRENGTH. 00Z RUC MODEL INDICATED THAT MUCAPES VALUES FROM 1000-
1500 J/KG WILL BE PRESENT OVER SERN SD...SWRN/WCENTRAL MN AND NWRN
IA OVER THE NEXT SEVERAL HOURS. 30 TO 40 KT CLOUD BEARING SHEAR
WOULD SUPPORT SOME UPDRAFT ROTATION AND THE THREAT FOR MARGINALLY
SEVERE HAIL.


..CROSBIE.. 08/10/02

...PLEASE SEE WWW.SPC.NOAA.GOV/ FOR GRAPHIC PRODUCT...
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