000
ACUS11 KWNS 210759
SWOMCD
SPC MCD 210759
OHZ000-KYZ000-INZ000-ILZ000-MOZ000-210930-

MESOSCALE DISCUSSION 0744
NWS STORM PREDICTION CENTER NORMAN OK
0259 AM CDT TUE MAY 21 2013

AREAS AFFECTED...SRN IND...SWRN OH...FAR SRN IL...FAR SERN MO...AND
FAR WRN KY

CONCERNING...TORNADO WATCH 197...

VALID 210759Z - 210930Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 197 CONTINUES.

SUMMARY...POTENTIAL FOR A CONTINUED EWD SEVERE WEATHER THREAT
/PRIMARILY DAMAGING WINDS/ EXISTS INTO PARTS OF SERN-EAST CENTRAL
IND EARLY THIS MORNING...AND THUS WW 197 HAS BEEN EXPANDED EWD BY
WFO IND. COUNTIES CAN BE REMOVED FROM THIS WW WITH THE PASSAGE OF
THE TSTM LINE.

FAR SERN-EAST CENTRAL IND INTO SWRN OH WILL CONTINUE TO BE MONITORED
FOR A SVR WEATHER THREAT /LOCALLY STRONG WIND GUSTS/ AND THE
POTENTIAL NEED FOR A NEW WW AS THE LINE OF STORMS IN IND ADVANCES
EWD.

DISCUSSION...REGIONAL RADAR IMAGERY SHOWED A LINE OF TSTMS EXTENDING
NEARLY N-S FROM NORTH CENTRAL TO SOUTH CENTRAL IND...WITH THIS
ACTIVITY THEN TRAILING SWWD THROUGH SWRN IND INTO FAR SRN IL.  CLOUD
TOPS ACROSS MUCH OF WW 197 ARE WARMING...CAPPI RADAR IMAGERY SHOWS A
WEAKENING TREND...AND LIGHTNING COVERAGE IS DIMINISHING WITH THE
CONVECTION IN CENTRAL/SRN IND.  THESE FACTORS SUGGEST THE OVERALL
SEVERE WEATHER THREAT SHOULD CONTINUE TO WANE.  HOWEVER...A 50 KT
WLY REAR INFLOW JET OBSERVED AT WSR-88D IND AT 0730Z AND DOWNSTREAM
MODERATE INSTABILITY WILL SUPPORT A CONTINUED EWD ADVANCEMENT OF THE
CONVECTIVE LINE INTO SWRN OH BY 09Z.  RECENT SURFACE OBSERVATIONS IN
CENTRAL IND INDICATED SUB-SEVERE WIND GUSTS...AND THUS MAY BE
REFLECTING THE LACK OF BETTER SUPPORT FOR A SUSTAINED BOW.

..PETERS/HART.. 05/21/2013

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

ATTN...WFO...ILN...LMK...IWX...IND...PAH...

LAT...LON   36648988 38148904 38178820 38558722 39348658 40448654
            40458441 39608426 38988471 38628607 38048692 37138777
            36508824 36648988

000
ACUS11 KWNS 210759
SWOMCD
SPC MCD 210759
OHZ000-KYZ000-INZ000-ILZ000-MOZ000-210930-

MESOSCALE DISCUSSION 0744
NWS STORM PREDICTION CENTER NORMAN OK
0259 AM CDT TUE MAY 21 2013

AREAS AFFECTED...SRN IND...SWRN OH...FAR SRN IL...FAR SERN MO...AND
FAR WRN KY

CONCERNING...TORNADO WATCH 197...

VALID 210759Z - 210930Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 197 CONTINUES.

SUMMARY...POTENTIAL FOR A CONTINUED EWD SEVERE WEATHER THREAT
/PRIMARILY DAMAGING WINDS/ EXISTS INTO PARTS OF SERN-EAST CENTRAL
IND EARLY THIS MORNING...AND THUS WW 197 HAS BEEN EXPANDED EWD BY
WFO IND. COUNTIES CAN BE REMOVED FROM THIS WW WITH THE PASSAGE OF
THE TSTM LINE.

FAR SERN-EAST CENTRAL IND INTO SWRN OH WILL CONTINUE TO BE MONITORED
FOR A SVR WEATHER THREAT /LOCALLY STRONG WIND GUSTS/ AND THE
POTENTIAL NEED FOR A NEW WW AS THE LINE OF STORMS IN IND ADVANCES
EWD.

DISCUSSION...REGIONAL RADAR IMAGERY SHOWED A LINE OF TSTMS EXTENDING
NEARLY N-S FROM NORTH CENTRAL TO SOUTH CENTRAL IND...WITH THIS
ACTIVITY THEN TRAILING SWWD THROUGH SWRN IND INTO FAR SRN IL.  CLOUD
TOPS ACROSS MUCH OF WW 197 ARE WARMING...CAPPI RADAR IMAGERY SHOWS A
WEAKENING TREND...AND LIGHTNING COVERAGE IS DIMINISHING WITH THE
CONVECTION IN CENTRAL/SRN IND.  THESE FACTORS SUGGEST THE OVERALL
SEVERE WEATHER THREAT SHOULD CONTINUE TO WANE.  HOWEVER...A 50 KT
WLY REAR INFLOW JET OBSERVED AT WSR-88D IND AT 0730Z AND DOWNSTREAM
MODERATE INSTABILITY WILL SUPPORT A CONTINUED EWD ADVANCEMENT OF THE
CONVECTIVE LINE INTO SWRN OH BY 09Z.  RECENT SURFACE OBSERVATIONS IN
CENTRAL IND INDICATED SUB-SEVERE WIND GUSTS...AND THUS MAY BE
REFLECTING THE LACK OF BETTER SUPPORT FOR A SUSTAINED BOW.

..PETERS/HART.. 05/21/2013

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

ATTN...WFO...ILN...LMK...IWX...IND...PAH...

LAT...LON   36648988 38148904 38178820 38558722 39348658 40448654
            40458441 39608426 38988471 38628607 38048692 37138777
            36508824 36648988

000
ACUS11 KWNS 210759
SWOMCD
SPC MCD 210759
OHZ000-KYZ000-INZ000-ILZ000-MOZ000-210930-

MESOSCALE DISCUSSION 0744
NWS STORM PREDICTION CENTER NORMAN OK
0259 AM CDT TUE MAY 21 2013

AREAS AFFECTED...SRN IND...SWRN OH...FAR SRN IL...FAR SERN MO...AND
FAR WRN KY

CONCERNING...TORNADO WATCH 197...

VALID 210759Z - 210930Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 197 CONTINUES.

SUMMARY...POTENTIAL FOR A CONTINUED EWD SEVERE WEATHER THREAT
/PRIMARILY DAMAGING WINDS/ EXISTS INTO PARTS OF SERN-EAST CENTRAL
IND EARLY THIS MORNING...AND THUS WW 197 HAS BEEN EXPANDED EWD BY
WFO IND. COUNTIES CAN BE REMOVED FROM THIS WW WITH THE PASSAGE OF
THE TSTM LINE.

FAR SERN-EAST CENTRAL IND INTO SWRN OH WILL CONTINUE TO BE MONITORED
FOR A SVR WEATHER THREAT /LOCALLY STRONG WIND GUSTS/ AND THE
POTENTIAL NEED FOR A NEW WW AS THE LINE OF STORMS IN IND ADVANCES
EWD.

DISCUSSION...REGIONAL RADAR IMAGERY SHOWED A LINE OF TSTMS EXTENDING
NEARLY N-S FROM NORTH CENTRAL TO SOUTH CENTRAL IND...WITH THIS
ACTIVITY THEN TRAILING SWWD THROUGH SWRN IND INTO FAR SRN IL.  CLOUD
TOPS ACROSS MUCH OF WW 197 ARE WARMING...CAPPI RADAR IMAGERY SHOWS A
WEAKENING TREND...AND LIGHTNING COVERAGE IS DIMINISHING WITH THE
CONVECTION IN CENTRAL/SRN IND.  THESE FACTORS SUGGEST THE OVERALL
SEVERE WEATHER THREAT SHOULD CONTINUE TO WANE.  HOWEVER...A 50 KT
WLY REAR INFLOW JET OBSERVED AT WSR-88D IND AT 0730Z AND DOWNSTREAM
MODERATE INSTABILITY WILL SUPPORT A CONTINUED EWD ADVANCEMENT OF THE
CONVECTIVE LINE INTO SWRN OH BY 09Z.  RECENT SURFACE OBSERVATIONS IN
CENTRAL IND INDICATED SUB-SEVERE WIND GUSTS...AND THUS MAY BE
REFLECTING THE LACK OF BETTER SUPPORT FOR A SUSTAINED BOW.

..PETERS/HART.. 05/21/2013

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

ATTN...WFO...ILN...LMK...IWX...IND...PAH...

LAT...LON   36648988 38148904 38178820 38558722 39348658 40448654
            40458441 39608426 38988471 38628607 38048692 37138777
            36508824 36648988

000
ACUS03 KWNS 210730
SWODY3
SPC AC 210729

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0229 AM CDT TUE MAY 21 2013

VALID 231200Z - 241200Z

...THERE IS A SLGT RISK OF SVR TSTMS TX/OK PANHANDLE VICINITY...

...SYNOPSIS...
AN ERN NOAM UPPER TROUGH IS FORECAST TO CONTINUE EWD THIS
PERIOD...WHILE UPSTREAM RIDGING SPREADS EWD INTO THE CENTRAL U.S.
AHEAD OF THE NEXT UPPER SYSTEM.  THIS SYSTEM -- A LARGE/VERY UPPER
LOW OVER THE PAC NW...WILL MAKE VERY LITTLE PROGRESS THROUGH THE
PERIOD.

AT THE SURFACE...A COLD FRONT CROSSING MT/WY/THE GREAT BASIN WILL --
LIKE ITS PARENT UPPER SYSTEM -- MAKE ONLY SLOW EWD PROGRESS.
MEANWHILE...A SECOND FRONT WILL CONTINUE ADVANCING ACROSS THE NERN
U.S. TOWARD THE ATLANTIC COAST.

...TX/OK PANHANDLE VICINITY...
SUBSIDENCE/CAPPING IS FORECAST ACROSS THE SRN HIGH PLAINS REGION
UNDER THE EVOLVING UPPER RIDGE.  HOWEVER...STRONG INSTABILITY ABOVE
THE CAP AND STRONGLY VEERING FLOW WITH HEIGHT OTHERWISE INDICATE
SOME POTENTIAL FOR SEVERE WEATHER.

MODELS -- TO VARYING DEGREES -- DO FORECAST AT LEAST ISOLATED STORM
INITIATION INVOF THE TX/OK PANHANDLE VICINITY.  ANY STORM WHICH
COULD DEVELOP WOULD LIKELY ORGANIZE RAPIDLY AND BECOME
SEVERE/SUPERCELLULAR.  THUS -- WILL INTRODUCE CONDITIONAL SLIGHT
RISK ACROSS THIS REGION...WITH REFINEMENTS LIKELY TO BE NEEDED IN
LATER FORECASTS AS CONVECTIVE POTENTIAL BECOMES MORE CLEAR.

...NEW ENGLAND SWD ACROSS THE MID-ATLANTIC REGION...
AMPLE FLOW ALOFT BUT WEAK INSTABILITY SHOULD CHARACTERIZE THE
PRE-FRONTAL WARM SECTOR ACROSS THE NORTHEAST AND MID-ATLANTIC REGION
THURSDAY.  THUS -- OVERALL SEVERE POTENTIAL APPEARS RELATIVELY LOW
ATTM.  WILL INTRODUCE LOW SEVERE WEATHER PROBABILITY ACROSS THIS
AREA FOR ISOLATED HAIL/WIND THREAT WHERE A FEW STRONGER AFTERNOON
STORMS CAN FORM...BUT WILL WAIT UNTIL LATER OUTLOOKS TO ISSUE A MORE
SPECIFIC/POSSIBLY HIGHER-PROBABILITY FORECAST.

..GOSS.. 05/21/2013

000
ACUS03 KWNS 210730
SWODY3
SPC AC 210729

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0229 AM CDT TUE MAY 21 2013

VALID 231200Z - 241200Z

...THERE IS A SLGT RISK OF SVR TSTMS TX/OK PANHANDLE VICINITY...

...SYNOPSIS...
AN ERN NOAM UPPER TROUGH IS FORECAST TO CONTINUE EWD THIS
PERIOD...WHILE UPSTREAM RIDGING SPREADS EWD INTO THE CENTRAL U.S.
AHEAD OF THE NEXT UPPER SYSTEM.  THIS SYSTEM -- A LARGE/VERY UPPER
LOW OVER THE PAC NW...WILL MAKE VERY LITTLE PROGRESS THROUGH THE
PERIOD.

AT THE SURFACE...A COLD FRONT CROSSING MT/WY/THE GREAT BASIN WILL --
LIKE ITS PARENT UPPER SYSTEM -- MAKE ONLY SLOW EWD PROGRESS.
MEANWHILE...A SECOND FRONT WILL CONTINUE ADVANCING ACROSS THE NERN
U.S. TOWARD THE ATLANTIC COAST.

...TX/OK PANHANDLE VICINITY...
SUBSIDENCE/CAPPING IS FORECAST ACROSS THE SRN HIGH PLAINS REGION
UNDER THE EVOLVING UPPER RIDGE.  HOWEVER...STRONG INSTABILITY ABOVE
THE CAP AND STRONGLY VEERING FLOW WITH HEIGHT OTHERWISE INDICATE
SOME POTENTIAL FOR SEVERE WEATHER.

MODELS -- TO VARYING DEGREES -- DO FORECAST AT LEAST ISOLATED STORM
INITIATION INVOF THE TX/OK PANHANDLE VICINITY.  ANY STORM WHICH
COULD DEVELOP WOULD LIKELY ORGANIZE RAPIDLY AND BECOME
SEVERE/SUPERCELLULAR.  THUS -- WILL INTRODUCE CONDITIONAL SLIGHT
RISK ACROSS THIS REGION...WITH REFINEMENTS LIKELY TO BE NEEDED IN
LATER FORECASTS AS CONVECTIVE POTENTIAL BECOMES MORE CLEAR.

...NEW ENGLAND SWD ACROSS THE MID-ATLANTIC REGION...
AMPLE FLOW ALOFT BUT WEAK INSTABILITY SHOULD CHARACTERIZE THE
PRE-FRONTAL WARM SECTOR ACROSS THE NORTHEAST AND MID-ATLANTIC REGION
THURSDAY.  THUS -- OVERALL SEVERE POTENTIAL APPEARS RELATIVELY LOW
ATTM.  WILL INTRODUCE LOW SEVERE WEATHER PROBABILITY ACROSS THIS
AREA FOR ISOLATED HAIL/WIND THREAT WHERE A FEW STRONGER AFTERNOON
STORMS CAN FORM...BUT WILL WAIT UNTIL LATER OUTLOOKS TO ISSUE A MORE
SPECIFIC/POSSIBLY HIGHER-PROBABILITY FORECAST.

..GOSS.. 05/21/2013

000
ACUS01 KWNS 210601
SWODY1
SPC AC 210559

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT TUE MAY 21 2013

VALID 211200Z - 221200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SW AR...SE
OK...NW LA...CNTRL TX AND NE TX...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
PLAINS...OZARKS...MID MS VALLEY...OH VALLEY AND GREAT LAKES...

...SRN PLAINS/ARKLATEX/MID-MS VALLEY...
AN UPPER-LEVEL TROUGH WILL MOVE EWD FROM THE SRN ROCKIES INTO THE
SRN PLAINS TODAY. AT THE SFC...A COLD FRONT WILL ADVANCE SEWD ACROSS
CNTRL OK AND WCNTRL TX. AHEAD OF THE FRONT...SFC DEWPOINTS ACROSS
THE WARM SECTOR SHOULD BE IN THE MID TO UPPER 60S F RESULTING IN
MODERATE TO STRONG INSTABILITY BY THIS AFTERNOON. THUNDERSTORMS ARE
FORECAST TO BE ONGOING AT THE START OF THE PERIOD ACROSS ERN OK
WHERE AN ISOLATED THREAT FOR HAIL AND WIND DAMAGE MAY EXIST THIS
MORNING. WITH SFC HEATING...NEW THUNDERSTORMS ARE FORECAST TO
INITIATE ALONG AND AHEAD OF THE COLD FRONT FROM WRN AR SWWD INTO
NORTH TX AROUND MIDDAY. THE MODELS QUICKLY EXPAND THUNDERSTORM
COVERAGE WITH AN MCS ORGANIZING AND MOVING SEWD ACROSS THE MODERATE
RISK AREA. STRONG INSTABILITY...STEEP MID-LEVEL LAPSE RATES AND
MODERATE TO STRONG DEEP LAYER SHEAR SHOULD BE SUPPORTIVE OF
WIDESPREAD SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE MODERATE RISK
AREA WHERE A SIGNIFICANT SEVERE WEATHER EVENT WILL BE POSSIBLE.

FORECAST SOUNDINGS AT 00Z/WED FROM LITTLE ROCK SWWD TO AROUND THE
DALLAS FORT WORTH METROPLEX SHOW MLCAPE VALUES OF 2500 TO 4000 J/KG
WITH 0-6KM SHEAR OF 45 TO 55 KT. THIS ALONG WITH 850 TO 500 MB LAPSE
RATES AROUND 7.5 C/KM SHOULD RESULT IN A POTENTIAL FOR SUPERCELLS
WITH LARGE HAIL. HAILSTONES OF GREATER THAN 2 INCHES IN DIAMETER
WILL BE POSSIBLE WITH THE MORE INTENSE SUPERCELLS. IN ADDITION...THE
MORE DOMINANT SUPERCELLS SHOULD BE CAPABLE OF PRODUCING TORNADOES AS
THE LOW-LEVEL JET STRENGTHENS. A FEW STRONG TORNADOES COULD OCCUR
NEAR THE LOW-LEVEL JET AS BOUNDARY LAYER SHEAR BECOMES MORE
FAVORABLE DURING THE EARLY EVENING. THE MODELS SUGGEST CELLS MAY BE
DISCRETE AT THE START OF THE EVENT WITH A TRANSITION TO A
SQUALL-LINE. THIS WOULD MAKE THE WIND DAMAGE THREAT INCREASINGLY
DOMINANT AS A LINEAR MCS ORGANIZES EARLY THIS EVENING. FOR THIS
REASON...AN ENHANCED WIND DAMAGE THREAT WILL BE POSSIBLE ACROSS THE
MODERATE RISK AREA.

...GREAT LAKES/OH VALLEY...
SOUTHWEST FLOW WILL BE IN PLACE TODAY FROM THE MID-MS VALLEY NEWD
INTO THE GREAT LAKES REGION. AT THE SFC...A LOW IS FORECAST TO MOVE
EWD ACROSS THE UPPER MS VALLEY WITH A CORRIDOR OF LOW-LEVEL MOISTURE
EXTENDING NNEWD FROM THE LOWER OH VALLEY INTO LOWER MI. SFC
DEWPOINTS ACROSS SRN IL...NW IND AND LOWER MI SHOULD BE IN THE MID
60S F RESULTING IN MODERATE DESTABILIZATION. MODEL FORECASTS
INITIATE STORMS BY MID AFTERNOON ALONG THE INSTABILITY AXIS WITH
STORMS MOVING NEWD ACROSS THE REGION. FORECAST SOUNDINGS ALONG THE
INSTABILITY AXIS WEST OF DETROIT AND NORTH OF INDIANAPOLIS AT 21Z
SHOW MLCAPE VALUES IN THE 1000 TO 2000 J/KG RANGE WITH STEEP
LOW-LEVEL LAPSE RATES AND UNIDIRECTIONAL WIND PROFILES. THIS
ENVIRONMENT SHOULD BE FAVORABLE FOR WIND DAMAGE AS CELLS INCREASE IN
COVERAGE THIS AFTERNOON. SEVERAL MODEL FORECASTS SHOW AN ENHANCED
SEVERE THREAT ACROSS LOWER MI TO THE SOUTHEAST OF THE SFC LOW AND ON
THE NOSE OF THE LOW-LEVEL JET. FOR THIS REASON...AN ENHANCED WIND
DAMAGE THREAT WILL BE POSSIBLE WITH BOWING LINE-SEGMENTS IN LOWER MI
LATE THIS AFTERNOON. LARGE HAIL AND A FEW TORNADOES MAY ALSO OCCUR
WITH THE MORE INTENSE CELLS.

...NRN APPALACHIAN MTNS...
AN UPPER-LEVEL RIDGE WILL BE IN PLACE TODAY ACROSS THE APPALACHIAN
MTNS. IN SPITE OF THE RIDGE...MODERATE INSTABILITY IS FORECAST TO
DEVELOP FROM PA NEWD ACROSS CNTRL NY WHERE SFC DEWPOINTS SHOULD BE
IN THE LOWER TO MID 60S F. THE MODELS APPEAR TO MOVE A DISTURBANCE
OVER THE TOP OF THE RIDGE WHICH WOULD HELP WITH CONVECTIVE
INITIATION THIS AFTERNOON. IF STORMS CAN DEVELOP IN SPITE OF THE
WEAK LARGE-SCALE ASCENT...THEN STEEP LOW-LEVEL LAPSE RATES COUPLED
WITH MODERATE INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR COULD BE
SUPPORTIVE OF A MARGINAL WIND DAMAGE THREAT.

..BROYLES/MEAD.. 05/21/2013

000
ACUS01 KWNS 210601
SWODY1
SPC AC 210559

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT TUE MAY 21 2013

VALID 211200Z - 221200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF SW AR...SE
OK...NW LA...CNTRL TX AND NE TX...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
PLAINS...OZARKS...MID MS VALLEY...OH VALLEY AND GREAT LAKES...

...SRN PLAINS/ARKLATEX/MID-MS VALLEY...
AN UPPER-LEVEL TROUGH WILL MOVE EWD FROM THE SRN ROCKIES INTO THE
SRN PLAINS TODAY. AT THE SFC...A COLD FRONT WILL ADVANCE SEWD ACROSS
CNTRL OK AND WCNTRL TX. AHEAD OF THE FRONT...SFC DEWPOINTS ACROSS
THE WARM SECTOR SHOULD BE IN THE MID TO UPPER 60S F RESULTING IN
MODERATE TO STRONG INSTABILITY BY THIS AFTERNOON. THUNDERSTORMS ARE
FORECAST TO BE ONGOING AT THE START OF THE PERIOD ACROSS ERN OK
WHERE AN ISOLATED THREAT FOR HAIL AND WIND DAMAGE MAY EXIST THIS
MORNING. WITH SFC HEATING...NEW THUNDERSTORMS ARE FORECAST TO
INITIATE ALONG AND AHEAD OF THE COLD FRONT FROM WRN AR SWWD INTO
NORTH TX AROUND MIDDAY. THE MODELS QUICKLY EXPAND THUNDERSTORM
COVERAGE WITH AN MCS ORGANIZING AND MOVING SEWD ACROSS THE MODERATE
RISK AREA. STRONG INSTABILITY...STEEP MID-LEVEL LAPSE RATES AND
MODERATE TO STRONG DEEP LAYER SHEAR SHOULD BE SUPPORTIVE OF
WIDESPREAD SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE MODERATE RISK
AREA WHERE A SIGNIFICANT SEVERE WEATHER EVENT WILL BE POSSIBLE.

FORECAST SOUNDINGS AT 00Z/WED FROM LITTLE ROCK SWWD TO AROUND THE
DALLAS FORT WORTH METROPLEX SHOW MLCAPE VALUES OF 2500 TO 4000 J/KG
WITH 0-6KM SHEAR OF 45 TO 55 KT. THIS ALONG WITH 850 TO 500 MB LAPSE
RATES AROUND 7.5 C/KM SHOULD RESULT IN A POTENTIAL FOR SUPERCELLS
WITH LARGE HAIL. HAILSTONES OF GREATER THAN 2 INCHES IN DIAMETER
WILL BE POSSIBLE WITH THE MORE INTENSE SUPERCELLS. IN ADDITION...THE
MORE DOMINANT SUPERCELLS SHOULD BE CAPABLE OF PRODUCING TORNADOES AS
THE LOW-LEVEL JET STRENGTHENS. A FEW STRONG TORNADOES COULD OCCUR
NEAR THE LOW-LEVEL JET AS BOUNDARY LAYER SHEAR BECOMES MORE
FAVORABLE DURING THE EARLY EVENING. THE MODELS SUGGEST CELLS MAY BE
DISCRETE AT THE START OF THE EVENT WITH A TRANSITION TO A
SQUALL-LINE. THIS WOULD MAKE THE WIND DAMAGE THREAT INCREASINGLY
DOMINANT AS A LINEAR MCS ORGANIZES EARLY THIS EVENING. FOR THIS
REASON...AN ENHANCED WIND DAMAGE THREAT WILL BE POSSIBLE ACROSS THE
MODERATE RISK AREA.

...GREAT LAKES/OH VALLEY...
SOUTHWEST FLOW WILL BE IN PLACE TODAY FROM THE MID-MS VALLEY NEWD
INTO THE GREAT LAKES REGION. AT THE SFC...A LOW IS FORECAST TO MOVE
EWD ACROSS THE UPPER MS VALLEY WITH A CORRIDOR OF LOW-LEVEL MOISTURE
EXTENDING NNEWD FROM THE LOWER OH VALLEY INTO LOWER MI. SFC
DEWPOINTS ACROSS SRN IL...NW IND AND LOWER MI SHOULD BE IN THE MID
60S F RESULTING IN MODERATE DESTABILIZATION. MODEL FORECASTS
INITIATE STORMS BY MID AFTERNOON ALONG THE INSTABILITY AXIS WITH
STORMS MOVING NEWD ACROSS THE REGION. FORECAST SOUNDINGS ALONG THE
INSTABILITY AXIS WEST OF DETROIT AND NORTH OF INDIANAPOLIS AT 21Z
SHOW MLCAPE VALUES IN THE 1000 TO 2000 J/KG RANGE WITH STEEP
LOW-LEVEL LAPSE RATES AND UNIDIRECTIONAL WIND PROFILES. THIS
ENVIRONMENT SHOULD BE FAVORABLE FOR WIND DAMAGE AS CELLS INCREASE IN
COVERAGE THIS AFTERNOON. SEVERAL MODEL FORECASTS SHOW AN ENHANCED
SEVERE THREAT ACROSS LOWER MI TO THE SOUTHEAST OF THE SFC LOW AND ON
THE NOSE OF THE LOW-LEVEL JET. FOR THIS REASON...AN ENHANCED WIND
DAMAGE THREAT WILL BE POSSIBLE WITH BOWING LINE-SEGMENTS IN LOWER MI
LATE THIS AFTERNOON. LARGE HAIL AND A FEW TORNADOES MAY ALSO OCCUR
WITH THE MORE INTENSE CELLS.

...NRN APPALACHIAN MTNS...
AN UPPER-LEVEL RIDGE WILL BE IN PLACE TODAY ACROSS THE APPALACHIAN
MTNS. IN SPITE OF THE RIDGE...MODERATE INSTABILITY IS FORECAST TO
DEVELOP FROM PA NEWD ACROSS CNTRL NY WHERE SFC DEWPOINTS SHOULD BE
IN THE LOWER TO MID 60S F. THE MODELS APPEAR TO MOVE A DISTURBANCE
OVER THE TOP OF THE RIDGE WHICH WOULD HELP WITH CONVECTIVE
INITIATION THIS AFTERNOON. IF STORMS CAN DEVELOP IN SPITE OF THE
WEAK LARGE-SCALE ASCENT...THEN STEEP LOW-LEVEL LAPSE RATES COUPLED
WITH MODERATE INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR COULD BE
SUPPORTIVE OF A MARGINAL WIND DAMAGE THREAT.

..BROYLES/MEAD.. 05/21/2013

000
ACUS02 KWNS 210556
SWODY2
SPC AC 210554

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CDT TUE MAY 21 2013

VALID 221200Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM NY SWWD TO SRN OH/NERN
KY/WV...

...SYNOPSIS...
A LARGE UPPER LOW CENTERED OVER THE WA/ORE REGION -- AND
BROADER/ASSOCIATED TROUGH COVERING MUCH OF THE WRN U.S. -- IS
FORECAST TO DIG VERY SLOWLY SWD WITH TIME...WHILE A SECOND UPPER
LOW/TROUGH DROPS SWD OVER NRN QUEBEC INVOF HUDSON/JAMES BAY.  S OF
THIS CANADIAN LOW...A SHORT-WAVE TROUGH IS FORECAST TO CROSS THE
MIDWEST/OH VALLEY REGION...BECOMING PHASED WITH THE CANADIAN SYSTEM
THROUGH THE PERIOD.

AT THE SURFACE...A STRONG COLD FRONT IS FORECAST TO MOVE SLOWLY
EWD/SEWD ACROSS WRN PORTIONS OF MT AND WY AND THE GREAT BASIN
REGION.  FARTHER E...A COLD FRONT CROSSING THE OH VALLEY REGION WILL
FOCUS THE MAIN AREA OF SEVERE POTENTIAL THIS PERIOD.

...NY/PA/WV/OH/NERN KY/THE WRN MD PANHANDLE...
CLOUDS/PRECIPITATION WILL LIKELY RESIDE ACROSS MUCH OF THE SLIGHT
RISK AREA AT THE START OF THE PERIOD...WHICH WILL ACT TO HINDER
DIURNAL HEATING/DESTABILIZATION ACROSS THIS REGION.  HOWEVER...AS
THE UPPER TROUGH AND ASSOCIATED SURFACE COLD FRONT ADVANCE EWD
ACROSS THE MIDWEST/OH VALLEY AREA...EXPECT AN AFTERNOON INCREASE IN
CONVECTIVE COVERAGE/INTENSITY.  STRENGTHENING OF THE CONVECTION WILL
BE AUGMENTED BY STRONGER FLOW ALOFT AHEAD OF THE TROUGH AS IT
SPREADS ACROSS THE MID AND UPPER OH VALLEY AND INTO THE NORTHEAST.
THEREFORE -- WHILE TEMPERED BY THE MODEST DESTABILIZATION IN MOST
AREAS...BANDS OF STORMS CAPABLE OF PRODUCING ISOLATED DAMAGING WINDS
AND POSSIBLY ISOLATED/MARGINAL HAIL STILL APPEAR POSSIBLE -- THUS
JUSTIFYING CONTINUATION OF SLIGHT RISK ACROSS THIS AREA.

...MID SOUTH/CENTRAL GULF COAST REGION TO THE LOWER MS VALLEY...
MODEST INSTABILITY AND SLIGHTLY WEAKER FLOW ALOFT SUGGEST THAT
AFTERNOON STORMS WILL BE A BIT LESS ORGANIZED ACROSS MOST AREAS SW
OF THE OH VALLEY.  THEREFORE...WILL MAINTAIN ONLY 5% SEVERE
PROBABILITY ACROSS THIS BROAD AREA ATTM.

..GOSS.. 05/21/2013

000
ACUS02 KWNS 210556
SWODY2
SPC AC 210554

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1254 AM CDT TUE MAY 21 2013

VALID 221200Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM NY SWWD TO SRN OH/NERN
KY/WV...

...SYNOPSIS...
A LARGE UPPER LOW CENTERED OVER THE WA/ORE REGION -- AND
BROADER/ASSOCIATED TROUGH COVERING MUCH OF THE WRN U.S. -- IS
FORECAST TO DIG VERY SLOWLY SWD WITH TIME...WHILE A SECOND UPPER
LOW/TROUGH DROPS SWD OVER NRN QUEBEC INVOF HUDSON/JAMES BAY.  S OF
THIS CANADIAN LOW...A SHORT-WAVE TROUGH IS FORECAST TO CROSS THE
MIDWEST/OH VALLEY REGION...BECOMING PHASED WITH THE CANADIAN SYSTEM
THROUGH THE PERIOD.

AT THE SURFACE...A STRONG COLD FRONT IS FORECAST TO MOVE SLOWLY
EWD/SEWD ACROSS WRN PORTIONS OF MT AND WY AND THE GREAT BASIN
REGION.  FARTHER E...A COLD FRONT CROSSING THE OH VALLEY REGION WILL
FOCUS THE MAIN AREA OF SEVERE POTENTIAL THIS PERIOD.

...NY/PA/WV/OH/NERN KY/THE WRN MD PANHANDLE...
CLOUDS/PRECIPITATION WILL LIKELY RESIDE ACROSS MUCH OF THE SLIGHT
RISK AREA AT THE START OF THE PERIOD...WHICH WILL ACT TO HINDER
DIURNAL HEATING/DESTABILIZATION ACROSS THIS REGION.  HOWEVER...AS
THE UPPER TROUGH AND ASSOCIATED SURFACE COLD FRONT ADVANCE EWD
ACROSS THE MIDWEST/OH VALLEY AREA...EXPECT AN AFTERNOON INCREASE IN
CONVECTIVE COVERAGE/INTENSITY.  STRENGTHENING OF THE CONVECTION WILL
BE AUGMENTED BY STRONGER FLOW ALOFT AHEAD OF THE TROUGH AS IT
SPREADS ACROSS THE MID AND UPPER OH VALLEY AND INTO THE NORTHEAST.
THEREFORE -- WHILE TEMPERED BY THE MODEST DESTABILIZATION IN MOST
AREAS...BANDS OF STORMS CAPABLE OF PRODUCING ISOLATED DAMAGING WINDS
AND POSSIBLY ISOLATED/MARGINAL HAIL STILL APPEAR POSSIBLE -- THUS
JUSTIFYING CONTINUATION OF SLIGHT RISK ACROSS THIS AREA.

...MID SOUTH/CENTRAL GULF COAST REGION TO THE LOWER MS VALLEY...
MODEST INSTABILITY AND SLIGHTLY WEAKER FLOW ALOFT SUGGEST THAT
AFTERNOON STORMS WILL BE A BIT LESS ORGANIZED ACROSS MOST AREAS SW
OF THE OH VALLEY.  THEREFORE...WILL MAINTAIN ONLY 5% SEVERE
PROBABILITY ACROSS THIS BROAD AREA ATTM.

..GOSS.. 05/21/2013

000
ACUS11 KWNS 210436
SWOMCD
SPC MCD 210436
OKZ000-210500-

MESOSCALE DISCUSSION 0743
NWS STORM PREDICTION CENTER NORMAN OK
1136 PM CDT MON MAY 20 2013

AREAS AFFECTED...SRN AND E-CNTRL OK

CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY

VALID 210436Z - 210500Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SOME STORMS WILL BE CAPABLE OF A LARGE HAIL THREAT
TONIGHT.  A SEVERE THUNDERSTORM WATCH WILL LIKELY BE PROPOSED
SHORTLY.

DISCUSSION...WDSS-II RADAR DATA SHOWS SEVERAL THUNDERSTORMS OVER
S-CNTRL OK WITH ESTIMATED HAIL SIZE AOA 1 INCH.  SURFACE ANALYSIS
PLACES A CONVECTIVE OUTFLOW BOUNDARY ALONG THE RED RIVER VICINITY
AND THE STRONG WARM ADVECTION REGIME ONGOING OVER THE REGION WOULD
SEEMINGLY SUPPORT A FOCUSED AREA FOR STRONG-SEVERE STORMS CAPABLE OF
LARGE HAIL WITH THE MOST VIGOROUS UPDRAFTS.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   34399566 34409812 34769816 35349560 34399566

000
ACUS11 KWNS 210436
SWOMCD
SPC MCD 210436
OKZ000-210500-

MESOSCALE DISCUSSION 0743
NWS STORM PREDICTION CENTER NORMAN OK
1136 PM CDT MON MAY 20 2013

AREAS AFFECTED...SRN AND E-CNTRL OK

CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY

VALID 210436Z - 210500Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SOME STORMS WILL BE CAPABLE OF A LARGE HAIL THREAT
TONIGHT.  A SEVERE THUNDERSTORM WATCH WILL LIKELY BE PROPOSED
SHORTLY.

DISCUSSION...WDSS-II RADAR DATA SHOWS SEVERAL THUNDERSTORMS OVER
S-CNTRL OK WITH ESTIMATED HAIL SIZE AOA 1 INCH.  SURFACE ANALYSIS
PLACES A CONVECTIVE OUTFLOW BOUNDARY ALONG THE RED RIVER VICINITY
AND THE STRONG WARM ADVECTION REGIME ONGOING OVER THE REGION WOULD
SEEMINGLY SUPPORT A FOCUSED AREA FOR STRONG-SEVERE STORMS CAPABLE OF
LARGE HAIL WITH THE MOST VIGOROUS UPDRAFTS.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   34399566 34409812 34769816 35349560 34399566

000
ACUS11 KWNS 210436
SWOMCD
SPC MCD 210436
OKZ000-210500-

MESOSCALE DISCUSSION 0743
NWS STORM PREDICTION CENTER NORMAN OK
1136 PM CDT MON MAY 20 2013

AREAS AFFECTED...SRN AND E-CNTRL OK

CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY

VALID 210436Z - 210500Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SOME STORMS WILL BE CAPABLE OF A LARGE HAIL THREAT
TONIGHT.  A SEVERE THUNDERSTORM WATCH WILL LIKELY BE PROPOSED
SHORTLY.

DISCUSSION...WDSS-II RADAR DATA SHOWS SEVERAL THUNDERSTORMS OVER
S-CNTRL OK WITH ESTIMATED HAIL SIZE AOA 1 INCH.  SURFACE ANALYSIS
PLACES A CONVECTIVE OUTFLOW BOUNDARY ALONG THE RED RIVER VICINITY
AND THE STRONG WARM ADVECTION REGIME ONGOING OVER THE REGION WOULD
SEEMINGLY SUPPORT A FOCUSED AREA FOR STRONG-SEVERE STORMS CAPABLE OF
LARGE HAIL WITH THE MOST VIGOROUS UPDRAFTS.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   34399566 34409812 34769816 35349560 34399566

000
ACUS11 KWNS 210426
SWOMCD
SPC MCD 210425
MIZ000-210500-

MESOSCALE DISCUSSION 0742
NWS STORM PREDICTION CENTER NORMAN OK
1125 PM CDT MON MAY 20 2013

AREAS AFFECTED...SWRN LOWER MICH / NRN IND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 210425Z - 210500Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...SOME STRONG TO LOCALLY SEVERE WIND DAMAGE THREAT WILL
PROBABLY AFFECT SWRN LOWER MICH TONIGHT.

DISCUSSION...RADAR MOSAIC SHOWS A WELL ORGANIZED QLCS LOCATED OVER
NRN IL AND A POSSIBLE WARM ADVECTION WING OF STORMS DEVELOPING OVER
SRN LAKE MICH IN ADVANCE OF THE QLCS.  RECENTLY ASOS MEASURED 39 KT
WIND GUSTS WERE OBSERVED AT KMDW AND KORD WHILE A 51 KT GUST WAS
MEASURED AT KFEP IN WAKE OF THE QLCS.  THE ENVIRONMENT AHEAD OF THE
QLCS IS CHARACTERIZED BY A STRONG LOW LEVEL WIND PROFILE OF 40-45
KTS AT 0.5-1.0 KM AGL SAMPLED BY THE KIWX AND KGRR VWP/S.  GIVEN
ADEQUATE INSTABILITY AND A SHORTWAVE TROUGH /FORCING FOR ASCENT/
MOVING TOWARD THE REGION...IT SEEMS PROBABLE THE QLCS WILL CONTINUE
EWD AND POSE AT LEAST A DMGG WIND THREAT OWING TO STRONG/LOCALLY
SEVERE WIND GUSTS.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...GRR...

LAT...LON   42148502 42298631 43208617 43608467 42148502

000
ACUS11 KWNS 210426
SWOMCD
SPC MCD 210425
MIZ000-210500-

MESOSCALE DISCUSSION 0742
NWS STORM PREDICTION CENTER NORMAN OK
1125 PM CDT MON MAY 20 2013

AREAS AFFECTED...SWRN LOWER MICH / NRN IND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 210425Z - 210500Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...SOME STRONG TO LOCALLY SEVERE WIND DAMAGE THREAT WILL
PROBABLY AFFECT SWRN LOWER MICH TONIGHT.

DISCUSSION...RADAR MOSAIC SHOWS A WELL ORGANIZED QLCS LOCATED OVER
NRN IL AND A POSSIBLE WARM ADVECTION WING OF STORMS DEVELOPING OVER
SRN LAKE MICH IN ADVANCE OF THE QLCS.  RECENTLY ASOS MEASURED 39 KT
WIND GUSTS WERE OBSERVED AT KMDW AND KORD WHILE A 51 KT GUST WAS
MEASURED AT KFEP IN WAKE OF THE QLCS.  THE ENVIRONMENT AHEAD OF THE
QLCS IS CHARACTERIZED BY A STRONG LOW LEVEL WIND PROFILE OF 40-45
KTS AT 0.5-1.0 KM AGL SAMPLED BY THE KIWX AND KGRR VWP/S.  GIVEN
ADEQUATE INSTABILITY AND A SHORTWAVE TROUGH /FORCING FOR ASCENT/
MOVING TOWARD THE REGION...IT SEEMS PROBABLE THE QLCS WILL CONTINUE
EWD AND POSE AT LEAST A DMGG WIND THREAT OWING TO STRONG/LOCALLY
SEVERE WIND GUSTS.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...GRR...

LAT...LON   42148502 42298631 43208617 43608467 42148502

000
ACUS11 KWNS 210426
SWOMCD
SPC MCD 210425
MIZ000-210500-

MESOSCALE DISCUSSION 0742
NWS STORM PREDICTION CENTER NORMAN OK
1125 PM CDT MON MAY 20 2013

AREAS AFFECTED...SWRN LOWER MICH / NRN IND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 210425Z - 210500Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...SOME STRONG TO LOCALLY SEVERE WIND DAMAGE THREAT WILL
PROBABLY AFFECT SWRN LOWER MICH TONIGHT.

DISCUSSION...RADAR MOSAIC SHOWS A WELL ORGANIZED QLCS LOCATED OVER
NRN IL AND A POSSIBLE WARM ADVECTION WING OF STORMS DEVELOPING OVER
SRN LAKE MICH IN ADVANCE OF THE QLCS.  RECENTLY ASOS MEASURED 39 KT
WIND GUSTS WERE OBSERVED AT KMDW AND KORD WHILE A 51 KT GUST WAS
MEASURED AT KFEP IN WAKE OF THE QLCS.  THE ENVIRONMENT AHEAD OF THE
QLCS IS CHARACTERIZED BY A STRONG LOW LEVEL WIND PROFILE OF 40-45
KTS AT 0.5-1.0 KM AGL SAMPLED BY THE KIWX AND KGRR VWP/S.  GIVEN
ADEQUATE INSTABILITY AND A SHORTWAVE TROUGH /FORCING FOR ASCENT/
MOVING TOWARD THE REGION...IT SEEMS PROBABLE THE QLCS WILL CONTINUE
EWD AND POSE AT LEAST A DMGG WIND THREAT OWING TO STRONG/LOCALLY
SEVERE WIND GUSTS.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...GRR...

LAT...LON   42148502 42298631 43208617 43608467 42148502

000
ACUS11 KWNS 210325
SWOMCD
SPC MCD 210325
INZ000-MIZ000-KYZ000-ILZ000-TNZ000-MOZ000-ARZ000-210430-

MESOSCALE DISCUSSION 0741
NWS STORM PREDICTION CENTER NORMAN OK
1025 PM CDT MON MAY 20 2013

AREAS AFFECTED...W-CNTRL IN / E-CNTRL AND SRN IL / FAR SERN MO / FAR
WRN KY

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 210325Z - 210430Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE DAMAGING WIND THREAT WILL LIKELY PERSIST FARTHER E
OVER NRN-WRN IND SWD TO THE MS/OH RIVER CONFLUENCE REGION TONIGHT.
2 SEPARATE SEVERE THUNDERSTORM WATCHES WILL LIKELY BE PROPOSED.

DISCUSSION...RADAR MOSAIC SHOWS A WELL ORGANIZED QLCS FROM NRN IL
SWWD INTO SWRN AR.  A RECENTLY MEASURED 60 KT WIND GUST FROM AN ASOS
AROUND 35 MIN AGO IN THE GREATER ST. LOUIS AREA INDICATES THIS QLCS
IS LIKELY PRODUCING WIND DAMAGE AS IT MOVES EWD ACROSS THE MID MS
RIVER VALLEY.  THE LOW LEVEL FLOW AND INSTABILITY ARE MORE THAN
ADEQUATE TO SUSTAIN THIS QLCS WELL INTO THE LATE EVENING AND
OVERNIGHT HOURS DOWNSTREAM OVER FAR SERN MO AND SRN IL...EVENTUALLY
MOVING INTO W-CNTRL IN AND FAR WRN KY LATER TONIGHT.  ALTHOUGH A
BRIEF WEAK TORNADO IS POSSIBLE WITH ANY STRONGER
MESOVORTEX...CURRENT THINKING IS WIND DAMAGE WILL BE THE PRIMARY
SEVERE THREAT/CONCERN.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...IWX...IND...PAH...LOT...ILX...MEG...LSX...

LAT...LON   38898900 40308852 40368851 41618741 41788632 41448585
            39308673 37868769 36608875 36148995 36719106 38898900

000
ACUS11 KWNS 210325
SWOMCD
SPC MCD 210325
INZ000-MIZ000-KYZ000-ILZ000-TNZ000-MOZ000-ARZ000-210430-

MESOSCALE DISCUSSION 0741
NWS STORM PREDICTION CENTER NORMAN OK
1025 PM CDT MON MAY 20 2013

AREAS AFFECTED...W-CNTRL IN / E-CNTRL AND SRN IL / FAR SERN MO / FAR
WRN KY

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 210325Z - 210430Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE DAMAGING WIND THREAT WILL LIKELY PERSIST FARTHER E
OVER NRN-WRN IND SWD TO THE MS/OH RIVER CONFLUENCE REGION TONIGHT.
2 SEPARATE SEVERE THUNDERSTORM WATCHES WILL LIKELY BE PROPOSED.

DISCUSSION...RADAR MOSAIC SHOWS A WELL ORGANIZED QLCS FROM NRN IL
SWWD INTO SWRN AR.  A RECENTLY MEASURED 60 KT WIND GUST FROM AN ASOS
AROUND 35 MIN AGO IN THE GREATER ST. LOUIS AREA INDICATES THIS QLCS
IS LIKELY PRODUCING WIND DAMAGE AS IT MOVES EWD ACROSS THE MID MS
RIVER VALLEY.  THE LOW LEVEL FLOW AND INSTABILITY ARE MORE THAN
ADEQUATE TO SUSTAIN THIS QLCS WELL INTO THE LATE EVENING AND
OVERNIGHT HOURS DOWNSTREAM OVER FAR SERN MO AND SRN IL...EVENTUALLY
MOVING INTO W-CNTRL IN AND FAR WRN KY LATER TONIGHT.  ALTHOUGH A
BRIEF WEAK TORNADO IS POSSIBLE WITH ANY STRONGER
MESOVORTEX...CURRENT THINKING IS WIND DAMAGE WILL BE THE PRIMARY
SEVERE THREAT/CONCERN.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...IWX...IND...PAH...LOT...ILX...MEG...LSX...

LAT...LON   38898900 40308852 40368851 41618741 41788632 41448585
            39308673 37868769 36608875 36148995 36719106 38898900

000
ACUS11 KWNS 210325
SWOMCD
SPC MCD 210325
INZ000-MIZ000-KYZ000-ILZ000-TNZ000-MOZ000-ARZ000-210430-

MESOSCALE DISCUSSION 0741
NWS STORM PREDICTION CENTER NORMAN OK
1025 PM CDT MON MAY 20 2013

AREAS AFFECTED...W-CNTRL IN / E-CNTRL AND SRN IL / FAR SERN MO / FAR
WRN KY

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 210325Z - 210430Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE DAMAGING WIND THREAT WILL LIKELY PERSIST FARTHER E
OVER NRN-WRN IND SWD TO THE MS/OH RIVER CONFLUENCE REGION TONIGHT.
2 SEPARATE SEVERE THUNDERSTORM WATCHES WILL LIKELY BE PROPOSED.

DISCUSSION...RADAR MOSAIC SHOWS A WELL ORGANIZED QLCS FROM NRN IL
SWWD INTO SWRN AR.  A RECENTLY MEASURED 60 KT WIND GUST FROM AN ASOS
AROUND 35 MIN AGO IN THE GREATER ST. LOUIS AREA INDICATES THIS QLCS
IS LIKELY PRODUCING WIND DAMAGE AS IT MOVES EWD ACROSS THE MID MS
RIVER VALLEY.  THE LOW LEVEL FLOW AND INSTABILITY ARE MORE THAN
ADEQUATE TO SUSTAIN THIS QLCS WELL INTO THE LATE EVENING AND
OVERNIGHT HOURS DOWNSTREAM OVER FAR SERN MO AND SRN IL...EVENTUALLY
MOVING INTO W-CNTRL IN AND FAR WRN KY LATER TONIGHT.  ALTHOUGH A
BRIEF WEAK TORNADO IS POSSIBLE WITH ANY STRONGER
MESOVORTEX...CURRENT THINKING IS WIND DAMAGE WILL BE THE PRIMARY
SEVERE THREAT/CONCERN.

..SMITH/CORFIDI.. 05/21/2013

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

ATTN...WFO...IWX...IND...PAH...LOT...ILX...MEG...LSX...

LAT...LON   38898900 40308852 40368851 41618741 41788632 41448585
            39308673 37868769 36608875 36148995 36719106 38898900

000
ACUS11 KWNS 210233
SWOMCD
SPC MCD 210233
IAZ000-210330-

MESOSCALE DISCUSSION 0740
NWS STORM PREDICTION CENTER NORMAN OK
0933 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL AND ERN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 194...

VALID 210233Z - 210330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 194
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND SEVERE HAIL CONTINUES IN
THE NEAR TERM...BUT SEVERE STORM POTENTIAL SHOULD BEGIN TO DIMINISH
BY 04Z.

DISCUSSION...A BROKEN BAND OF STRONG TO SEVERE TSTMS CONTINUES FROM
NEAR AND NE OF ALO TO JUST E OF LWD AS OF 0220Z WITH THE MOST
INTENSE STORMS LOCATED OVER MARSHALL...TAMA...AND DECATUR COUNTIES.
RECENT TRENDS IN SURFACE OBSERVATIONS INDICATE A STEADY COOLING OF
THE INFLOW AIR MASS TO THESE STORMS...RESULTING IN DECREASING
INSTABILITY AND A GRADUAL ACCUMULATION OF CONVECTIVE INHIBITION.
UPLIFT ALONG THE EXISTING STORM-SCALE COLD POOLS...AND DEEPER-LAYER
FORCING ATTENDANT TO A VORTICITY MAXIMUM MOVING THROUGH THE LOWER-MO
VALLEY WILL LIKELY SUSTAIN ONGOING STORMS WITH A CONTINUED RISK FOR
ISOLATED SEVERE WEATHER.  THIS THREAT SHOULD BEGIN TO DIMINISH BY
04Z AS THE BOUNDARY LAYER FURTHER STABILIZES.

..MEAD.. 05/21/2013

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

ATTN...WFO...DVN...DMX...

LAT...LON   40689369 41259344 42319302 42829270 42889232 42679213
            42439218 42149171 42139154 41779155 41179142 40859161
            40669240 40689369

000
ACUS11 KWNS 210233
SWOMCD
SPC MCD 210233
IAZ000-210330-

MESOSCALE DISCUSSION 0740
NWS STORM PREDICTION CENTER NORMAN OK
0933 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL AND ERN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 194...

VALID 210233Z - 210330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 194
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND SEVERE HAIL CONTINUES IN
THE NEAR TERM...BUT SEVERE STORM POTENTIAL SHOULD BEGIN TO DIMINISH
BY 04Z.

DISCUSSION...A BROKEN BAND OF STRONG TO SEVERE TSTMS CONTINUES FROM
NEAR AND NE OF ALO TO JUST E OF LWD AS OF 0220Z WITH THE MOST
INTENSE STORMS LOCATED OVER MARSHALL...TAMA...AND DECATUR COUNTIES.
RECENT TRENDS IN SURFACE OBSERVATIONS INDICATE A STEADY COOLING OF
THE INFLOW AIR MASS TO THESE STORMS...RESULTING IN DECREASING
INSTABILITY AND A GRADUAL ACCUMULATION OF CONVECTIVE INHIBITION.
UPLIFT ALONG THE EXISTING STORM-SCALE COLD POOLS...AND DEEPER-LAYER
FORCING ATTENDANT TO A VORTICITY MAXIMUM MOVING THROUGH THE LOWER-MO
VALLEY WILL LIKELY SUSTAIN ONGOING STORMS WITH A CONTINUED RISK FOR
ISOLATED SEVERE WEATHER.  THIS THREAT SHOULD BEGIN TO DIMINISH BY
04Z AS THE BOUNDARY LAYER FURTHER STABILIZES.

..MEAD.. 05/21/2013

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

ATTN...WFO...DVN...DMX...

LAT...LON   40689369 41259344 42319302 42829270 42889232 42679213
            42439218 42149171 42139154 41779155 41179142 40859161
            40669240 40689369

000
ACUS11 KWNS 210233
SWOMCD
SPC MCD 210233
IAZ000-210330-

MESOSCALE DISCUSSION 0740
NWS STORM PREDICTION CENTER NORMAN OK
0933 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL AND ERN IA

CONCERNING...SEVERE THUNDERSTORM WATCH 194...

VALID 210233Z - 210330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 194
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND SEVERE HAIL CONTINUES IN
THE NEAR TERM...BUT SEVERE STORM POTENTIAL SHOULD BEGIN TO DIMINISH
BY 04Z.

DISCUSSION...A BROKEN BAND OF STRONG TO SEVERE TSTMS CONTINUES FROM
NEAR AND NE OF ALO TO JUST E OF LWD AS OF 0220Z WITH THE MOST
INTENSE STORMS LOCATED OVER MARSHALL...TAMA...AND DECATUR COUNTIES.
RECENT TRENDS IN SURFACE OBSERVATIONS INDICATE A STEADY COOLING OF
THE INFLOW AIR MASS TO THESE STORMS...RESULTING IN DECREASING
INSTABILITY AND A GRADUAL ACCUMULATION OF CONVECTIVE INHIBITION.
UPLIFT ALONG THE EXISTING STORM-SCALE COLD POOLS...AND DEEPER-LAYER
FORCING ATTENDANT TO A VORTICITY MAXIMUM MOVING THROUGH THE LOWER-MO
VALLEY WILL LIKELY SUSTAIN ONGOING STORMS WITH A CONTINUED RISK FOR
ISOLATED SEVERE WEATHER.  THIS THREAT SHOULD BEGIN TO DIMINISH BY
04Z AS THE BOUNDARY LAYER FURTHER STABILIZES.

..MEAD.. 05/21/2013

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

ATTN...WFO...DVN...DMX...

LAT...LON   40689369 41259344 42319302 42829270 42889232 42679213
            42439218 42149171 42139154 41779155 41179142 40859161
            40669240 40689369

000
ACUS11 KWNS 210154
SWOMCD
SPC MCD 210153
ILZ000-MOZ000-210300-

MESOSCALE DISCUSSION 0739
NWS STORM PREDICTION CENTER NORMAN OK
0853 PM CDT MON MAY 20 2013

AREAS AFFECTED...NERN - E-CNTRL MO / W-CNTRL IL

CONCERNING...TORNADO WATCH 193...

VALID 210153Z - 210300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 193 CONTINUES.

SUMMARY...THE RISK FOR DAMAGING WINDS...LARGE HAIL...AND PERHAPS A
TORNADO CONTINUES ACROSS THE WATCH AREA.

DISCUSSION...A MATURE MCS HAS EVOLVED THIS EVENING FROM W-CNTRL IL
TO SWRN MO.  WITHIN THIS BROADER-SCALE CONVECTIVE SYSTEM...A LINE
SEGMENT FROM JUST E OF COU TO NEAR VIH AS OF 0140Z HAS SHOWN SIGNS
OF ACCELERATION WITH A FORWARD SPEED OF 40-45 KT CURRENTLY BEING
OBSERVED.  ADDITIONAL MORE DISCRETE CONVECTIVE ELEMENTS ARE FORMING
IMMEDIATELY DOWNSHEAR FROM THE PRIMARY CONVECTIVE BAND /FROM NEAR
STL TO NEAR AND N OF SPI/ WHERE LOW-LEVEL WAA IS LIKELY BEING
ENHANCED.

LATEST SURFACE OBSERVATIONS AND OBJECTIVE ANALYSES SUGGEST THAT THE
INFLOW AIR MASS TO THESE STORMS REMAINS MOIST AND MODERATELY
UNSTABLE.  MOREOVER...THE STL VAD HAS SHOWN A NOTABLE INCREASE IN
THE SWLY WIND FIELD BELOW 4-5 KM AGL...WHICH WILL SUSTAIN ONGOING
STORM STRUCTURES.  WHILE DAMAGING WINDS AND LARGE HAIL WILL REMAIN
THE PRIMARY SEVERE WEATHER HAZARDS...A TORNADO OR TWO REMAINS
POSSIBLE WITH ANY EMBEDDED SUPERCELLS AND/OR QLCS-RELATED
MESOVORTICES.

..MEAD.. 05/21/2013

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

ATTN...WFO...ILX...LSX...DVN...

LAT...LON   39119215 40169209 40539086 40629043 40999023 41088979
            40938923 40488852 39718897 38838902 38408976 37989078
            37929115 39119215

000
ACUS11 KWNS 210154
SWOMCD
SPC MCD 210153
ILZ000-MOZ000-210300-

MESOSCALE DISCUSSION 0739
NWS STORM PREDICTION CENTER NORMAN OK
0853 PM CDT MON MAY 20 2013

AREAS AFFECTED...NERN - E-CNTRL MO / W-CNTRL IL

CONCERNING...TORNADO WATCH 193...

VALID 210153Z - 210300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 193 CONTINUES.

SUMMARY...THE RISK FOR DAMAGING WINDS...LARGE HAIL...AND PERHAPS A
TORNADO CONTINUES ACROSS THE WATCH AREA.

DISCUSSION...A MATURE MCS HAS EVOLVED THIS EVENING FROM W-CNTRL IL
TO SWRN MO.  WITHIN THIS BROADER-SCALE CONVECTIVE SYSTEM...A LINE
SEGMENT FROM JUST E OF COU TO NEAR VIH AS OF 0140Z HAS SHOWN SIGNS
OF ACCELERATION WITH A FORWARD SPEED OF 40-45 KT CURRENTLY BEING
OBSERVED.  ADDITIONAL MORE DISCRETE CONVECTIVE ELEMENTS ARE FORMING
IMMEDIATELY DOWNSHEAR FROM THE PRIMARY CONVECTIVE BAND /FROM NEAR
STL TO NEAR AND N OF SPI/ WHERE LOW-LEVEL WAA IS LIKELY BEING
ENHANCED.

LATEST SURFACE OBSERVATIONS AND OBJECTIVE ANALYSES SUGGEST THAT THE
INFLOW AIR MASS TO THESE STORMS REMAINS MOIST AND MODERATELY
UNSTABLE.  MOREOVER...THE STL VAD HAS SHOWN A NOTABLE INCREASE IN
THE SWLY WIND FIELD BELOW 4-5 KM AGL...WHICH WILL SUSTAIN ONGOING
STORM STRUCTURES.  WHILE DAMAGING WINDS AND LARGE HAIL WILL REMAIN
THE PRIMARY SEVERE WEATHER HAZARDS...A TORNADO OR TWO REMAINS
POSSIBLE WITH ANY EMBEDDED SUPERCELLS AND/OR QLCS-RELATED
MESOVORTICES.

..MEAD.. 05/21/2013

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

ATTN...WFO...ILX...LSX...DVN...

LAT...LON   39119215 40169209 40539086 40629043 40999023 41088979
            40938923 40488852 39718897 38838902 38408976 37989078
            37929115 39119215

000
ACUS11 KWNS 210154
SWOMCD
SPC MCD 210153
ILZ000-MOZ000-210300-

MESOSCALE DISCUSSION 0739
NWS STORM PREDICTION CENTER NORMAN OK
0853 PM CDT MON MAY 20 2013

AREAS AFFECTED...NERN - E-CNTRL MO / W-CNTRL IL

CONCERNING...TORNADO WATCH 193...

VALID 210153Z - 210300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 193 CONTINUES.

SUMMARY...THE RISK FOR DAMAGING WINDS...LARGE HAIL...AND PERHAPS A
TORNADO CONTINUES ACROSS THE WATCH AREA.

DISCUSSION...A MATURE MCS HAS EVOLVED THIS EVENING FROM W-CNTRL IL
TO SWRN MO.  WITHIN THIS BROADER-SCALE CONVECTIVE SYSTEM...A LINE
SEGMENT FROM JUST E OF COU TO NEAR VIH AS OF 0140Z HAS SHOWN SIGNS
OF ACCELERATION WITH A FORWARD SPEED OF 40-45 KT CURRENTLY BEING
OBSERVED.  ADDITIONAL MORE DISCRETE CONVECTIVE ELEMENTS ARE FORMING
IMMEDIATELY DOWNSHEAR FROM THE PRIMARY CONVECTIVE BAND /FROM NEAR
STL TO NEAR AND N OF SPI/ WHERE LOW-LEVEL WAA IS LIKELY BEING
ENHANCED.

LATEST SURFACE OBSERVATIONS AND OBJECTIVE ANALYSES SUGGEST THAT THE
INFLOW AIR MASS TO THESE STORMS REMAINS MOIST AND MODERATELY
UNSTABLE.  MOREOVER...THE STL VAD HAS SHOWN A NOTABLE INCREASE IN
THE SWLY WIND FIELD BELOW 4-5 KM AGL...WHICH WILL SUSTAIN ONGOING
STORM STRUCTURES.  WHILE DAMAGING WINDS AND LARGE HAIL WILL REMAIN
THE PRIMARY SEVERE WEATHER HAZARDS...A TORNADO OR TWO REMAINS
POSSIBLE WITH ANY EMBEDDED SUPERCELLS AND/OR QLCS-RELATED
MESOVORTICES.

..MEAD.. 05/21/2013

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

ATTN...WFO...ILX...LSX...DVN...

LAT...LON   39119215 40169209 40539086 40629043 40999023 41088979
            40938923 40488852 39718897 38838902 38408976 37989078
            37929115 39119215

000
ACUS11 KWNS 210145
SWOMCD
SPC MCD 210145
OKZ000-TXZ000-210245-

MESOSCALE DISCUSSION 0738
NWS STORM PREDICTION CENTER NORMAN OK
0845 PM CDT MON MAY 20 2013

AREAS AFFECTED...PORTIONS OF N-CNTRL AND CNTRL TX

CONCERNING...TORNADO WATCH 192...

VALID 210145Z - 210245Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 192 CONTINUES.

SUMMARY...THE TORNADO THREAT HAS DIMINISHED CONSIDERABLY OVER
PORTIONS OF N-CNTRL AND CNTRL TX EXCEPT FOR THE HAMILTON COUNTY
SUPERCELL.  A LINGERING TORNADO THREAT MAY PERSIST IN THE SHORT TERM
FOR HAMILTON COUNTY...IN ADDITION TO LARGE HAIL/LOCALLY DAMAGING
WINDS.

DISCUSSION...VISIBLE SATELLITE SHOWS NO FURTHER CUMULUS DEVELOPMENT
ALONG THE WESTWARD ADVANCING COMPOSITE DRYLINE/OUTFLOW FROM WRN
N-CNTRL TX SWD TO THE RIO GRANDE.  ALTHOUGH THE AIRMASS REMAINS
POTENTIALLY UNSTABLE...GRADUAL BOUNDARY LAYER COOLING WILL ACT TO
INCREASE CINH AND STRENGTHEN THE CAPPING INVERSION IN PLACE OVER
MUCH OF THE AREA.  AS A RESULT...THE REMAINING SEVERE THREAT APPEARS
CONFINED TO THE CLUSTER OF STRONG-SEVERE STORMS OVER
HAMILTON/COMANCHE COUNTIES.  CONVECTIVE TRENDS WILL CONTINUE TO BE
MONITORED BUT ATTM...IT DOES NOT APPEAR NECESSARY THAT A REPLACEMENT
WATCH WILL BE NEEDED.  IF THE HAMILTON/COMANCHE STORMS MAINTAIN
VIGOR CLOSE TO THE 03Z EXPIRATION TIME...THEN A LOCAL
EXTENSION-IN-TIME FOR AN HOUR MIGHT BE BEST SUITED TO ADDRESS THIS
POSSIBLE THREAT.

..SMITH.. 05/21/2013

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

ATTN...WFO...FWD...OUN...EWX...SJT...

LAT...LON   33179935 33899819 33719600 30469813 29859924 30330010
            32250019 33179935

000
ACUS11 KWNS 210145
SWOMCD
SPC MCD 210145
OKZ000-TXZ000-210245-

MESOSCALE DISCUSSION 0738
NWS STORM PREDICTION CENTER NORMAN OK
0845 PM CDT MON MAY 20 2013

AREAS AFFECTED...PORTIONS OF N-CNTRL AND CNTRL TX

CONCERNING...TORNADO WATCH 192...

VALID 210145Z - 210245Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 192 CONTINUES.

SUMMARY...THE TORNADO THREAT HAS DIMINISHED CONSIDERABLY OVER
PORTIONS OF N-CNTRL AND CNTRL TX EXCEPT FOR THE HAMILTON COUNTY
SUPERCELL.  A LINGERING TORNADO THREAT MAY PERSIST IN THE SHORT TERM
FOR HAMILTON COUNTY...IN ADDITION TO LARGE HAIL/LOCALLY DAMAGING
WINDS.

DISCUSSION...VISIBLE SATELLITE SHOWS NO FURTHER CUMULUS DEVELOPMENT
ALONG THE WESTWARD ADVANCING COMPOSITE DRYLINE/OUTFLOW FROM WRN
N-CNTRL TX SWD TO THE RIO GRANDE.  ALTHOUGH THE AIRMASS REMAINS
POTENTIALLY UNSTABLE...GRADUAL BOUNDARY LAYER COOLING WILL ACT TO
INCREASE CINH AND STRENGTHEN THE CAPPING INVERSION IN PLACE OVER
MUCH OF THE AREA.  AS A RESULT...THE REMAINING SEVERE THREAT APPEARS
CONFINED TO THE CLUSTER OF STRONG-SEVERE STORMS OVER
HAMILTON/COMANCHE COUNTIES.  CONVECTIVE TRENDS WILL CONTINUE TO BE
MONITORED BUT ATTM...IT DOES NOT APPEAR NECESSARY THAT A REPLACEMENT
WATCH WILL BE NEEDED.  IF THE HAMILTON/COMANCHE STORMS MAINTAIN
VIGOR CLOSE TO THE 03Z EXPIRATION TIME...THEN A LOCAL
EXTENSION-IN-TIME FOR AN HOUR MIGHT BE BEST SUITED TO ADDRESS THIS
POSSIBLE THREAT.

..SMITH.. 05/21/2013

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

ATTN...WFO...FWD...OUN...EWX...SJT...

LAT...LON   33179935 33899819 33719600 30469813 29859924 30330010
            32250019 33179935

000
ACUS11 KWNS 210145
SWOMCD
SPC MCD 210145
OKZ000-TXZ000-210245-

MESOSCALE DISCUSSION 0738
NWS STORM PREDICTION CENTER NORMAN OK
0845 PM CDT MON MAY 20 2013

AREAS AFFECTED...PORTIONS OF N-CNTRL AND CNTRL TX

CONCERNING...TORNADO WATCH 192...

VALID 210145Z - 210245Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 192 CONTINUES.

SUMMARY...THE TORNADO THREAT HAS DIMINISHED CONSIDERABLY OVER
PORTIONS OF N-CNTRL AND CNTRL TX EXCEPT FOR THE HAMILTON COUNTY
SUPERCELL.  A LINGERING TORNADO THREAT MAY PERSIST IN THE SHORT TERM
FOR HAMILTON COUNTY...IN ADDITION TO LARGE HAIL/LOCALLY DAMAGING
WINDS.

DISCUSSION...VISIBLE SATELLITE SHOWS NO FURTHER CUMULUS DEVELOPMENT
ALONG THE WESTWARD ADVANCING COMPOSITE DRYLINE/OUTFLOW FROM WRN
N-CNTRL TX SWD TO THE RIO GRANDE.  ALTHOUGH THE AIRMASS REMAINS
POTENTIALLY UNSTABLE...GRADUAL BOUNDARY LAYER COOLING WILL ACT TO
INCREASE CINH AND STRENGTHEN THE CAPPING INVERSION IN PLACE OVER
MUCH OF THE AREA.  AS A RESULT...THE REMAINING SEVERE THREAT APPEARS
CONFINED TO THE CLUSTER OF STRONG-SEVERE STORMS OVER
HAMILTON/COMANCHE COUNTIES.  CONVECTIVE TRENDS WILL CONTINUE TO BE
MONITORED BUT ATTM...IT DOES NOT APPEAR NECESSARY THAT A REPLACEMENT
WATCH WILL BE NEEDED.  IF THE HAMILTON/COMANCHE STORMS MAINTAIN
VIGOR CLOSE TO THE 03Z EXPIRATION TIME...THEN A LOCAL
EXTENSION-IN-TIME FOR AN HOUR MIGHT BE BEST SUITED TO ADDRESS THIS
POSSIBLE THREAT.

..SMITH.. 05/21/2013

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

ATTN...WFO...FWD...OUN...EWX...SJT...

LAT...LON   33179935 33899819 33719600 30469813 29859924 30330010
            32250019 33179935

000
ACUS11 KWNS 210107
SWOMCD
SPC MCD 210107
MOZ000-ILZ000-ARZ000-210130-

MESOSCALE DISCUSSION 0737
NWS STORM PREDICTION CENTER NORMAN OK
0807 PM CDT MON MAY 20 2013

AREAS AFFECTED...FAR W-CNTRL IL / CNTRL-SWRN MO

CONCERNING...TORNADO WATCH 190...193...

VALID 210107Z - 210130Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 190...193...CONTINUES.

SUMMARY...DAMAGING WINDS ARE BECOMING THE PREDOMINATE THREAT AS
STORMS CONTINUE TO GROW UPSCALE INTO A QLCS.  A TORNADO REMAINS
POSSIBLE WITH ANY STRONGER/LONGER-LIVED EMBEDDED MESOCYCLONE OR
MESOVORTEX.

DISCUSSION...RADAR MOSAIC SHOWS STORMS CONGEALING INTO A QLCS DURING
THE PAST HOUR AS CONVECTIVE MERGERS AND DIFFERENTIAL STORM MOTIONS
ACT TO FAVOR UPSCALE GROWTH.  THE 00Z/20 SGF RAOB EXHIBITED A VERY
MOIST BOUNDARY LAYER CONTRIBUTING TO MODERATE INSTABILITY /2400 J/KG
MLCAPE/ AND AN INCREASING/VEERING WIND PROFILE WITH HEIGHT.  STORMS
THAT CAN ORIENT PERPENDICULAR TO THE FLOW IN THE LOWEST 0-3 KM WILL
POSE AN ENHANCED THREAT FOR WIND DAMAGE.

..SMITH.. 05/21/2013

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

ATTN...WFO...ILX...LSX...LZK...SGF...

LAT...LON   37439314 39959133 39779059 39399040 36979226 36479308
            36669367 37439314

000
ACUS11 KWNS 210107
SWOMCD
SPC MCD 210107
MOZ000-ILZ000-ARZ000-210130-

MESOSCALE DISCUSSION 0737
NWS STORM PREDICTION CENTER NORMAN OK
0807 PM CDT MON MAY 20 2013

AREAS AFFECTED...FAR W-CNTRL IL / CNTRL-SWRN MO

CONCERNING...TORNADO WATCH 190...193...

VALID 210107Z - 210130Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 190...193...CONTINUES.

SUMMARY...DAMAGING WINDS ARE BECOMING THE PREDOMINATE THREAT AS
STORMS CONTINUE TO GROW UPSCALE INTO A QLCS.  A TORNADO REMAINS
POSSIBLE WITH ANY STRONGER/LONGER-LIVED EMBEDDED MESOCYCLONE OR
MESOVORTEX.

DISCUSSION...RADAR MOSAIC SHOWS STORMS CONGEALING INTO A QLCS DURING
THE PAST HOUR AS CONVECTIVE MERGERS AND DIFFERENTIAL STORM MOTIONS
ACT TO FAVOR UPSCALE GROWTH.  THE 00Z/20 SGF RAOB EXHIBITED A VERY
MOIST BOUNDARY LAYER CONTRIBUTING TO MODERATE INSTABILITY /2400 J/KG
MLCAPE/ AND AN INCREASING/VEERING WIND PROFILE WITH HEIGHT.  STORMS
THAT CAN ORIENT PERPENDICULAR TO THE FLOW IN THE LOWEST 0-3 KM WILL
POSE AN ENHANCED THREAT FOR WIND DAMAGE.

..SMITH.. 05/21/2013

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

ATTN...WFO...ILX...LSX...LZK...SGF...

LAT...LON   37439314 39959133 39779059 39399040 36979226 36479308
            36669367 37439314

000
ACUS11 KWNS 210107
SWOMCD
SPC MCD 210107
MOZ000-ILZ000-ARZ000-210130-

MESOSCALE DISCUSSION 0737
NWS STORM PREDICTION CENTER NORMAN OK
0807 PM CDT MON MAY 20 2013

AREAS AFFECTED...FAR W-CNTRL IL / CNTRL-SWRN MO

CONCERNING...TORNADO WATCH 190...193...

VALID 210107Z - 210130Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 190...193...CONTINUES.

SUMMARY...DAMAGING WINDS ARE BECOMING THE PREDOMINATE THREAT AS
STORMS CONTINUE TO GROW UPSCALE INTO A QLCS.  A TORNADO REMAINS
POSSIBLE WITH ANY STRONGER/LONGER-LIVED EMBEDDED MESOCYCLONE OR
MESOVORTEX.

DISCUSSION...RADAR MOSAIC SHOWS STORMS CONGEALING INTO A QLCS DURING
THE PAST HOUR AS CONVECTIVE MERGERS AND DIFFERENTIAL STORM MOTIONS
ACT TO FAVOR UPSCALE GROWTH.  THE 00Z/20 SGF RAOB EXHIBITED A VERY
MOIST BOUNDARY LAYER CONTRIBUTING TO MODERATE INSTABILITY /2400 J/KG
MLCAPE/ AND AN INCREASING/VEERING WIND PROFILE WITH HEIGHT.  STORMS
THAT CAN ORIENT PERPENDICULAR TO THE FLOW IN THE LOWEST 0-3 KM WILL
POSE AN ENHANCED THREAT FOR WIND DAMAGE.

..SMITH.. 05/21/2013

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

ATTN...WFO...ILX...LSX...LZK...SGF...

LAT...LON   37439314 39959133 39779059 39399040 36979226 36479308
            36669367 37439314

000
ACUS01 KWNS 210101
SWODY1
SPC AC 210059

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0759 PM CDT MON MAY 20 2013

VALID 210100Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MO...NW AR...ERN
OK...SRN OK AND NORTH TX...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
PLAINS...CNTRL PLAINS...OZARKS...MID-MS VALLEY...UPPER MS VALLEY AND
GREAT LAKES...

...SRN PLAINS/OZARKS/MID-MS VALLEY...
LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL TROUGH OVER THE
CNTRL AND SRN PLAINS WITH SOUTHWEST FLOW LOCATED FROM THE TROUGH
AXIS NEWD INTO THE MID-MS VALLEY. AN MCS IS CURRENTLY ONGOING ALONG
THIS CORRIDOR ON THE WRN EDGE OF A 30 TO 40 KT LOW-LEVEL JET. THE
LOW-LEVEL JET WILL CONTINUE TO STRENGTHEN EARLY THIS EVENING HELPING
TO MAINTAIN INTENSE CONVECTION ACROSS THE MODERATE RISK AREA. SFC
DEWPOINTS AHEAD OF THE MCS ARE IN THE UPPER 60S TO NEAR 70 F AND
OBJECTIVE ANALYSIS SHOWS MLCAPE VALUES IN THE 2500 TO 3500 J/KG
RANGE. THIS ALONG WITH 35 TO 45 KT OF DEEP LAYER SHEAR ACROSS THE
MODERATE RISK AREA DUE TO A CNTRL PLAINS MID-LEVEL JET...WILL
CONTINUE TO SUPPORT WIDESPREAD SEVERE THUNDERSTORMS THIS EVENING
WITH A SEVERE THREAT LASTING INTO THE OVERNIGHT PERIOD.

REGIONAL WSR-88D VWPS FROM ST. LOUIS SSWWD TO SPRINGFIELD MO INTO
NCNTRL TX SHOW DIRECTIONAL TURNING IN THE LOWEST 2 KM WITH
SUBSTANTIAL SPEED SHEAR RESULTING IN 0-3 KM STORM RELATIVE
HELICITIES IN THE 300 TO 400 M2/S2 RANGE. THIS ALONG WITH MODERATE
TO STRONG INSTABILITY SUGGESTS THAT THE THREAT FOR TORNADIC
SUPERCELLS WILL EXIST ACROSS AN AREA EXTENDING FROM CNTRL MO SWWD
INTO NORTH TX. AS THE LOW-LEVEL JET CONTINUES TO STRENGTHEN...A
POTENTIAL FOR STRONG TORNADOES WILL EXIST ACROSS THE MODERATE RISK
AREA. CONCERNING THE THREAT FOR LARGE HAIL...THE STEEPEST MID-LEVEL
LAPSE RATES EXIST ACROSS ERN OK AND NCNTRL TX WHERE THE MORE INTENSE
SUPERCELL WILL BE CAPABLE OF PRODUCING HAIL GREATER THAN 2 INCHES IN
DIAMETER. SUPERCELLS SHOULD ALSO BE CAPABLE OF PRODUCING SWATHS OF
WIND DAMAGE. THE WIND DAMAGE THREAT SHOULD BECOME ENHANCED EARLY
THIS EVENING AS THE MCS BECOMES INCREASINGLY LINEAR AND AS THE
LOW-LEVEL JET INTENSIFIES. THE SEVERE THREAT IS EXPECTED TO CONTINUE
INTO PART OF THE OVERNIGHT PERIOD DUE TO AMOUNT OF INSTABILITY THAT
IS CURRENTLY LOCATED AHEAD OF THE MCS.

...UPPER MS VALLEY/WRN GREAT LAKES...
AN UPPER-LEVEL LOW IS CURRENTLY LOCATED ACROSS THE NRN PLAINS
ACCORDING TO WATER VAPOR IMAGERY. AT THE SFC...A COLD FRONT IS
MOVING THROUGH THE NRN AND CNTRL PAINS WITH A CORRIDOR OF LOW-LEVEL
MOISTURE EXTENDING NWD INTO THE UPPER MS VALLEY. SFC DEWPOINTS
ACROSS THE UPPER MS VALLEY ARE IN THE UPPER 50S TO LOWER 60S F WITH
MID 60S F LOCATED IN LOWER MI. THIS IS RESULTING IN MLCAPE VALUES
ESTIMATED IN THE 750 TO 1250 J/KG RANGE ACROSS MUCH OF THE REGION.
IN ADDITION...OBJECTIVE ANALYSIS SHOWS 0-6KM SHEAR VALUES IN THE 40
TO 50 KT RANGE ACROSS THE NRN PART OF THE SLIGHT RISK AREA. AS THE
EXIT REGION OF A 70 TO 80 KT MID-LEVEL JET OVERSPREADS THE REGION
EARLY THIS EVENING...DEEP LAYER SHEAR WILL BE ENHANCED HELPING TO
SUPPORT SEVERE THUNDERSTORM DEVELOPMENT. MODEL FORECASTS SUGGEST
THAT THUNDERSTORM ACTIVITY WILL INCREASE IN COVERAGE THIS
EVENING...WITH STORMS MOVING NEWD ACROSS SRN MN...WI AND NRN IL. THE
ENVIRONMENT SHOULD SUPPORT SCATTERED SEVERE STORMS CAPABLE OF
PRODUCING WIND DAMAGE AND LARGE HAIL. AS LOW-LEVEL SHEAR INCREASES
THIS EVENING...A FEW TORNADOES MAY ALSO OCCUR WITH THE MORE INTENSE
CELLS. THE SEVERE THREAT SHOULD BECOME MORE ISOLATED AFTER MIDNIGHT
DUE TO THE WEAKER INSTABILITY THAT IS IN PLACE COMPARED TO AREAS
FURTHER SOUTH.

..BROYLES.. 05/21/2013

000
ACUS01 KWNS 210101
SWODY1
SPC AC 210059

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0759 PM CDT MON MAY 20 2013

VALID 210100Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF MO...NW AR...ERN
OK...SRN OK AND NORTH TX...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE SRN
PLAINS...CNTRL PLAINS...OZARKS...MID-MS VALLEY...UPPER MS VALLEY AND
GREAT LAKES...

...SRN PLAINS/OZARKS/MID-MS VALLEY...
LATEST WATER VAPOR IMAGERY SHOWS AN UPPER-LEVEL TROUGH OVER THE
CNTRL AND SRN PLAINS WITH SOUTHWEST FLOW LOCATED FROM THE TROUGH
AXIS NEWD INTO THE MID-MS VALLEY. AN MCS IS CURRENTLY ONGOING ALONG
THIS CORRIDOR ON THE WRN EDGE OF A 30 TO 40 KT LOW-LEVEL JET. THE
LOW-LEVEL JET WILL CONTINUE TO STRENGTHEN EARLY THIS EVENING HELPING
TO MAINTAIN INTENSE CONVECTION ACROSS THE MODERATE RISK AREA. SFC
DEWPOINTS AHEAD OF THE MCS ARE IN THE UPPER 60S TO NEAR 70 F AND
OBJECTIVE ANALYSIS SHOWS MLCAPE VALUES IN THE 2500 TO 3500 J/KG
RANGE. THIS ALONG WITH 35 TO 45 KT OF DEEP LAYER SHEAR ACROSS THE
MODERATE RISK AREA DUE TO A CNTRL PLAINS MID-LEVEL JET...WILL
CONTINUE TO SUPPORT WIDESPREAD SEVERE THUNDERSTORMS THIS EVENING
WITH A SEVERE THREAT LASTING INTO THE OVERNIGHT PERIOD.

REGIONAL WSR-88D VWPS FROM ST. LOUIS SSWWD TO SPRINGFIELD MO INTO
NCNTRL TX SHOW DIRECTIONAL TURNING IN THE LOWEST 2 KM WITH
SUBSTANTIAL SPEED SHEAR RESULTING IN 0-3 KM STORM RELATIVE
HELICITIES IN THE 300 TO 400 M2/S2 RANGE. THIS ALONG WITH MODERATE
TO STRONG INSTABILITY SUGGESTS THAT THE THREAT FOR TORNADIC
SUPERCELLS WILL EXIST ACROSS AN AREA EXTENDING FROM CNTRL MO SWWD
INTO NORTH TX. AS THE LOW-LEVEL JET CONTINUES TO STRENGTHEN...A
POTENTIAL FOR STRONG TORNADOES WILL EXIST ACROSS THE MODERATE RISK
AREA. CONCERNING THE THREAT FOR LARGE HAIL...THE STEEPEST MID-LEVEL
LAPSE RATES EXIST ACROSS ERN OK AND NCNTRL TX WHERE THE MORE INTENSE
SUPERCELL WILL BE CAPABLE OF PRODUCING HAIL GREATER THAN 2 INCHES IN
DIAMETER. SUPERCELLS SHOULD ALSO BE CAPABLE OF PRODUCING SWATHS OF
WIND DAMAGE. THE WIND DAMAGE THREAT SHOULD BECOME ENHANCED EARLY
THIS EVENING AS THE MCS BECOMES INCREASINGLY LINEAR AND AS THE
LOW-LEVEL JET INTENSIFIES. THE SEVERE THREAT IS EXPECTED TO CONTINUE
INTO PART OF THE OVERNIGHT PERIOD DUE TO AMOUNT OF INSTABILITY THAT
IS CURRENTLY LOCATED AHEAD OF THE MCS.

...UPPER MS VALLEY/WRN GREAT LAKES...
AN UPPER-LEVEL LOW IS CURRENTLY LOCATED ACROSS THE NRN PLAINS
ACCORDING TO WATER VAPOR IMAGERY. AT THE SFC...A COLD FRONT IS
MOVING THROUGH THE NRN AND CNTRL PAINS WITH A CORRIDOR OF LOW-LEVEL
MOISTURE EXTENDING NWD INTO THE UPPER MS VALLEY. SFC DEWPOINTS
ACROSS THE UPPER MS VALLEY ARE IN THE UPPER 50S TO LOWER 60S F WITH
MID 60S F LOCATED IN LOWER MI. THIS IS RESULTING IN MLCAPE VALUES
ESTIMATED IN THE 750 TO 1250 J/KG RANGE ACROSS MUCH OF THE REGION.
IN ADDITION...OBJECTIVE ANALYSIS SHOWS 0-6KM SHEAR VALUES IN THE 40
TO 50 KT RANGE ACROSS THE NRN PART OF THE SLIGHT RISK AREA. AS THE
EXIT REGION OF A 70 TO 80 KT MID-LEVEL JET OVERSPREADS THE REGION
EARLY THIS EVENING...DEEP LAYER SHEAR WILL BE ENHANCED HELPING TO
SUPPORT SEVERE THUNDERSTORM DEVELOPMENT. MODEL FORECASTS SUGGEST
THAT THUNDERSTORM ACTIVITY WILL INCREASE IN COVERAGE THIS
EVENING...WITH STORMS MOVING NEWD ACROSS SRN MN...WI AND NRN IL. THE
ENVIRONMENT SHOULD SUPPORT SCATTERED SEVERE STORMS CAPABLE OF
PRODUCING WIND DAMAGE AND LARGE HAIL. AS LOW-LEVEL SHEAR INCREASES
THIS EVENING...A FEW TORNADOES MAY ALSO OCCUR WITH THE MORE INTENSE
CELLS. THE SEVERE THREAT SHOULD BECOME MORE ISOLATED AFTER MIDNIGHT
DUE TO THE WEAKER INSTABILITY THAT IS IN PLACE COMPARED TO AREAS
FURTHER SOUTH.

..BROYLES.. 05/21/2013

000
ACUS11 KWNS 210018
SWOMCD
SPC MCD 210017
ILZ000-WIZ000-210115-

MESOSCALE DISCUSSION 0736
NWS STORM PREDICTION CENTER NORMAN OK
0717 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 210017Z - 210115Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS CAPABLE OF DAMAGING
WINDS...LARGE HAIL...AND PERHAPS A TORNADO IS EXPECTED TO DEVELOP
NEWD ACROSS THE AREA THIS EVENING INTO TONIGHT.  CONVECTIVE TRENDS
ARE BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...RECENT TRENDS IN REGIONAL RADAR DATA INDICATE TSTMS
DEVELOPING E OF THE MS RIVER /NW OF SPI/ IN ADVANCE OF AN EVOLVING
QLCS OVER MO.  VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
SUGGEST THAT THE ERN-MOST STORMS ARE FORMING NEAR AN OUTFLOW
BOUNDARY LIFTING NWD THROUGH CNTRL IL.  THE 00Z ILX APPEARS TO BE A
REASONABLE PROXY FOR THE ENVIRONMENT S OF THE OUTFLOW BOUNDARY WHERE
STEEP LAPSE RATES AND A MOIST PBL /LOWEST 100-MB MEAN-MIXING RATIOS
OF AROUND 13 G PER KG/ WERE YIELDING A MODERATELY UNSTABLE
ENVIRONMENT.  WHEN COUPLED WITH A VERTICALLY VEERING WIND PROFILE
WITH 40-50 KT SWLY MIDLEVEL WINDS...THE ENVIRONMENT APPEARS
SUPPORTIVE OF ORGANIZED STORM MODES...INCLUDING SUPERCELLS AND
BOWING STRUCTURES WITH A RISK FOR DAMAGING WINDS...LARGE HAIL...AND
PERHAPS A TORNADO.

..MEAD/CORFIDI.. 05/21/2013

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

ATTN...WFO...LOT...ILX...MKX...DVN...

LAT...LON   40779036 41699026 42638960 42578839 41918782 40698769
            40158830 40058942 40779036

000
ACUS11 KWNS 210018
SWOMCD
SPC MCD 210017
ILZ000-WIZ000-210115-

MESOSCALE DISCUSSION 0736
NWS STORM PREDICTION CENTER NORMAN OK
0717 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 210017Z - 210115Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS CAPABLE OF DAMAGING
WINDS...LARGE HAIL...AND PERHAPS A TORNADO IS EXPECTED TO DEVELOP
NEWD ACROSS THE AREA THIS EVENING INTO TONIGHT.  CONVECTIVE TRENDS
ARE BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...RECENT TRENDS IN REGIONAL RADAR DATA INDICATE TSTMS
DEVELOPING E OF THE MS RIVER /NW OF SPI/ IN ADVANCE OF AN EVOLVING
QLCS OVER MO.  VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
SUGGEST THAT THE ERN-MOST STORMS ARE FORMING NEAR AN OUTFLOW
BOUNDARY LIFTING NWD THROUGH CNTRL IL.  THE 00Z ILX APPEARS TO BE A
REASONABLE PROXY FOR THE ENVIRONMENT S OF THE OUTFLOW BOUNDARY WHERE
STEEP LAPSE RATES AND A MOIST PBL /LOWEST 100-MB MEAN-MIXING RATIOS
OF AROUND 13 G PER KG/ WERE YIELDING A MODERATELY UNSTABLE
ENVIRONMENT.  WHEN COUPLED WITH A VERTICALLY VEERING WIND PROFILE
WITH 40-50 KT SWLY MIDLEVEL WINDS...THE ENVIRONMENT APPEARS
SUPPORTIVE OF ORGANIZED STORM MODES...INCLUDING SUPERCELLS AND
BOWING STRUCTURES WITH A RISK FOR DAMAGING WINDS...LARGE HAIL...AND
PERHAPS A TORNADO.

..MEAD/CORFIDI.. 05/21/2013

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

ATTN...WFO...LOT...ILX...MKX...DVN...

LAT...LON   40779036 41699026 42638960 42578839 41918782 40698769
            40158830 40058942 40779036

000
ACUS11 KWNS 210018
SWOMCD
SPC MCD 210017
ILZ000-WIZ000-210115-

MESOSCALE DISCUSSION 0736
NWS STORM PREDICTION CENTER NORMAN OK
0717 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 210017Z - 210115Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS CAPABLE OF DAMAGING
WINDS...LARGE HAIL...AND PERHAPS A TORNADO IS EXPECTED TO DEVELOP
NEWD ACROSS THE AREA THIS EVENING INTO TONIGHT.  CONVECTIVE TRENDS
ARE BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...RECENT TRENDS IN REGIONAL RADAR DATA INDICATE TSTMS
DEVELOPING E OF THE MS RIVER /NW OF SPI/ IN ADVANCE OF AN EVOLVING
QLCS OVER MO.  VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
SUGGEST THAT THE ERN-MOST STORMS ARE FORMING NEAR AN OUTFLOW
BOUNDARY LIFTING NWD THROUGH CNTRL IL.  THE 00Z ILX APPEARS TO BE A
REASONABLE PROXY FOR THE ENVIRONMENT S OF THE OUTFLOW BOUNDARY WHERE
STEEP LAPSE RATES AND A MOIST PBL /LOWEST 100-MB MEAN-MIXING RATIOS
OF AROUND 13 G PER KG/ WERE YIELDING A MODERATELY UNSTABLE
ENVIRONMENT.  WHEN COUPLED WITH A VERTICALLY VEERING WIND PROFILE
WITH 40-50 KT SWLY MIDLEVEL WINDS...THE ENVIRONMENT APPEARS
SUPPORTIVE OF ORGANIZED STORM MODES...INCLUDING SUPERCELLS AND
BOWING STRUCTURES WITH A RISK FOR DAMAGING WINDS...LARGE HAIL...AND
PERHAPS A TORNADO.

..MEAD/CORFIDI.. 05/21/2013

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

ATTN...WFO...LOT...ILX...MKX...DVN...

LAT...LON   40779036 41699026 42638960 42578839 41918782 40698769
            40158830 40058942 40779036

000
ACUS11 KWNS 202353
SWOMCD
SPC MCD 202353
MOZ000-ARZ000-210100-

MESOSCALE DISCUSSION 0735
NWS STORM PREDICTION CENTER NORMAN OK
0653 PM CDT MON MAY 20 2013

AREAS AFFECTED...PORTIONS OF SERN MO / NRN AND W-CNTRL AR

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 202353Z - 210100Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A NEW TORNADO WATCH WILL LIKELY BE REQUIRED DOWNSTREAM
FROM THE EXISTING TORNADO WATCHES TO THE WEST.

DISCUSSION...SURFACE/UPPER AIR ANALYSIS INDICATES A MOIST/VERY
UNSTABLE AIRMASS RESIDES OVER AR AND THE MO OZARKS EARLY THIS
EVENING.  THE 00Z/20 SGF RAOB SHOWS A DEEP/MOIST BOUNDARY LAYER
FEATURING A 14.7 MEAN MIXING RATIO...FAVORABLE FOR SEVERE STORMS.
THE EXPECTED STRENGTHENING OF THE 1-2 KM FLOW OWING TO AN
INTENSIFICATION OF THE LOW LEVEL JET THIS EVENING WILL BECOME MORE
FAVORABLE FOR STORM ROTATION.  AN ADDITIONAL SUPPORTIVE FACTOR
INCLUDES A MORE FAVORABLE CONVECTIVE MODE AS THE BROKEN CONVECTIVE
BAND OF STORMS OVER ERN OK AND SWRN MO WOULD AT LEAST PROVIDE
OPPORTUNITY FOR LONGER TRACK SUPERCELLS TO MAINTAIN THEMSELVES PRIOR
TO UPSCALE GROWTH INTO A LINEAR MCS.  AS A RESULT...SOME SUPERCELL
TORNADO THREAT IN ADDITION TO DMGG WINDS AND LARGE HAIL...WILL
INCREASE THIS EVENING OVER AR AND SRN MO.

..SMITH/CORFIDI.. 05/20/2013

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...

LAT...LON   36629320 37679172 37709026 37229018 35879146 34919272
            34529366 34489443 34879439 36629320

000
ACUS11 KWNS 202353
SWOMCD
SPC MCD 202353
MOZ000-ARZ000-210100-

MESOSCALE DISCUSSION 0735
NWS STORM PREDICTION CENTER NORMAN OK
0653 PM CDT MON MAY 20 2013

AREAS AFFECTED...PORTIONS OF SERN MO / NRN AND W-CNTRL AR

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 202353Z - 210100Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A NEW TORNADO WATCH WILL LIKELY BE REQUIRED DOWNSTREAM
FROM THE EXISTING TORNADO WATCHES TO THE WEST.

DISCUSSION...SURFACE/UPPER AIR ANALYSIS INDICATES A MOIST/VERY
UNSTABLE AIRMASS RESIDES OVER AR AND THE MO OZARKS EARLY THIS
EVENING.  THE 00Z/20 SGF RAOB SHOWS A DEEP/MOIST BOUNDARY LAYER
FEATURING A 14.7 MEAN MIXING RATIO...FAVORABLE FOR SEVERE STORMS.
THE EXPECTED STRENGTHENING OF THE 1-2 KM FLOW OWING TO AN
INTENSIFICATION OF THE LOW LEVEL JET THIS EVENING WILL BECOME MORE
FAVORABLE FOR STORM ROTATION.  AN ADDITIONAL SUPPORTIVE FACTOR
INCLUDES A MORE FAVORABLE CONVECTIVE MODE AS THE BROKEN CONVECTIVE
BAND OF STORMS OVER ERN OK AND SWRN MO WOULD AT LEAST PROVIDE
OPPORTUNITY FOR LONGER TRACK SUPERCELLS TO MAINTAIN THEMSELVES PRIOR
TO UPSCALE GROWTH INTO A LINEAR MCS.  AS A RESULT...SOME SUPERCELL
TORNADO THREAT IN ADDITION TO DMGG WINDS AND LARGE HAIL...WILL
INCREASE THIS EVENING OVER AR AND SRN MO.

..SMITH/CORFIDI.. 05/20/2013

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...

LAT...LON   36629320 37679172 37709026 37229018 35879146 34919272
            34529366 34489443 34879439 36629320

000
ACUS11 KWNS 202353
SWOMCD
SPC MCD 202353
MOZ000-ARZ000-210100-

MESOSCALE DISCUSSION 0735
NWS STORM PREDICTION CENTER NORMAN OK
0653 PM CDT MON MAY 20 2013

AREAS AFFECTED...PORTIONS OF SERN MO / NRN AND W-CNTRL AR

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 202353Z - 210100Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A NEW TORNADO WATCH WILL LIKELY BE REQUIRED DOWNSTREAM
FROM THE EXISTING TORNADO WATCHES TO THE WEST.

DISCUSSION...SURFACE/UPPER AIR ANALYSIS INDICATES A MOIST/VERY
UNSTABLE AIRMASS RESIDES OVER AR AND THE MO OZARKS EARLY THIS
EVENING.  THE 00Z/20 SGF RAOB SHOWS A DEEP/MOIST BOUNDARY LAYER
FEATURING A 14.7 MEAN MIXING RATIO...FAVORABLE FOR SEVERE STORMS.
THE EXPECTED STRENGTHENING OF THE 1-2 KM FLOW OWING TO AN
INTENSIFICATION OF THE LOW LEVEL JET THIS EVENING WILL BECOME MORE
FAVORABLE FOR STORM ROTATION.  AN ADDITIONAL SUPPORTIVE FACTOR
INCLUDES A MORE FAVORABLE CONVECTIVE MODE AS THE BROKEN CONVECTIVE
BAND OF STORMS OVER ERN OK AND SWRN MO WOULD AT LEAST PROVIDE
OPPORTUNITY FOR LONGER TRACK SUPERCELLS TO MAINTAIN THEMSELVES PRIOR
TO UPSCALE GROWTH INTO A LINEAR MCS.  AS A RESULT...SOME SUPERCELL
TORNADO THREAT IN ADDITION TO DMGG WINDS AND LARGE HAIL...WILL
INCREASE THIS EVENING OVER AR AND SRN MO.

..SMITH/CORFIDI.. 05/20/2013

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

ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...

LAT...LON   36629320 37679172 37709026 37229018 35879146 34919272
            34529366 34489443 34879439 36629320

000
ACUS11 KWNS 202334
SWOMCD
SPC MCD 202333
OKZ000-TXZ000-210030-

MESOSCALE DISCUSSION 0734
NWS STORM PREDICTION CENTER NORMAN OK
0633 PM CDT MON MAY 20 2013

AREAS AFFECTED...OK/TX RED RIVER VALLEY

CONCERNING...TORNADO WATCH 191...192...

VALID 202333Z - 210030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 191...192...CONTINUES.

SUMMARY...IF CONVECTIVE MODE CAN REVERSE RECENT DETRIMENTAL TRENDS
AND BECOME SEMI-OPTIMAL AGAIN...THE THREAT FOR A STRONG TORNADO OR
TWO WILL INCREASE.

DISCUSSION...TRENDS OVER THE PAST 1-2 HRS FROM KFWS VWP SHOW THE
RECENT DEVELOPMENT OF A SICKLE-SHAPED HODOGRAPH /200-250 M2/S2 0-1
KM SRH/ AND BECOMING VERY FAVORABLE FOR THE INGESTION OF STREAMWISE
VORTICITY BY SUPERCELLS.  LOW LEVEL THERMODYNAMIC CHARACTERISTICS
CONTINUE TO BECOME ENHANCED...IMPLIED BY LOWER TEMP/DEWPOINT SPREADS
/I.E. LOWER MLLCL HEIGHT/ AHEAD OF THE EXISTING STORMS.  GIVEN THE
CONTINUALLY STRENGTHENING WIND PROFILE INTO THIS EVENING...THIS
WOULD SEEMINGLY SUPPORT AN INCREASED RISK FOR STRONG TORNADOES
--CONDITIONAL UPON STORMS MAINTAINING VIGOROUS LOW LEVEL
MESOCYCLONES.

..SMITH.. 05/20/2013

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

ATTN...WFO...FWD...OUN...

LAT...LON   33439679 33509774 33819779 34299698 34359616 33949596
            33439679

000
ACUS11 KWNS 202334
SWOMCD
SPC MCD 202333
OKZ000-TXZ000-210030-

MESOSCALE DISCUSSION 0734
NWS STORM PREDICTION CENTER NORMAN OK
0633 PM CDT MON MAY 20 2013

AREAS AFFECTED...OK/TX RED RIVER VALLEY

CONCERNING...TORNADO WATCH 191...192...

VALID 202333Z - 210030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 191...192...CONTINUES.

SUMMARY...IF CONVECTIVE MODE CAN REVERSE RECENT DETRIMENTAL TRENDS
AND BECOME SEMI-OPTIMAL AGAIN...THE THREAT FOR A STRONG TORNADO OR
TWO WILL INCREASE.

DISCUSSION...TRENDS OVER THE PAST 1-2 HRS FROM KFWS VWP SHOW THE
RECENT DEVELOPMENT OF A SICKLE-SHAPED HODOGRAPH /200-250 M2/S2 0-1
KM SRH/ AND BECOMING VERY FAVORABLE FOR THE INGESTION OF STREAMWISE
VORTICITY BY SUPERCELLS.  LOW LEVEL THERMODYNAMIC CHARACTERISTICS
CONTINUE TO BECOME ENHANCED...IMPLIED BY LOWER TEMP/DEWPOINT SPREADS
/I.E. LOWER MLLCL HEIGHT/ AHEAD OF THE EXISTING STORMS.  GIVEN THE
CONTINUALLY STRENGTHENING WIND PROFILE INTO THIS EVENING...THIS
WOULD SEEMINGLY SUPPORT AN INCREASED RISK FOR STRONG TORNADOES
--CONDITIONAL UPON STORMS MAINTAINING VIGOROUS LOW LEVEL
MESOCYCLONES.

..SMITH.. 05/20/2013

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

ATTN...WFO...FWD...OUN...

LAT...LON   33439679 33509774 33819779 34299698 34359616 33949596
            33439679

000
ACUS11 KWNS 202334
SWOMCD
SPC MCD 202333
OKZ000-TXZ000-210030-

MESOSCALE DISCUSSION 0734
NWS STORM PREDICTION CENTER NORMAN OK
0633 PM CDT MON MAY 20 2013

AREAS AFFECTED...OK/TX RED RIVER VALLEY

CONCERNING...TORNADO WATCH 191...192...

VALID 202333Z - 210030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 191...192...CONTINUES.

SUMMARY...IF CONVECTIVE MODE CAN REVERSE RECENT DETRIMENTAL TRENDS
AND BECOME SEMI-OPTIMAL AGAIN...THE THREAT FOR A STRONG TORNADO OR
TWO WILL INCREASE.

DISCUSSION...TRENDS OVER THE PAST 1-2 HRS FROM KFWS VWP SHOW THE
RECENT DEVELOPMENT OF A SICKLE-SHAPED HODOGRAPH /200-250 M2/S2 0-1
KM SRH/ AND BECOMING VERY FAVORABLE FOR THE INGESTION OF STREAMWISE
VORTICITY BY SUPERCELLS.  LOW LEVEL THERMODYNAMIC CHARACTERISTICS
CONTINUE TO BECOME ENHANCED...IMPLIED BY LOWER TEMP/DEWPOINT SPREADS
/I.E. LOWER MLLCL HEIGHT/ AHEAD OF THE EXISTING STORMS.  GIVEN THE
CONTINUALLY STRENGTHENING WIND PROFILE INTO THIS EVENING...THIS
WOULD SEEMINGLY SUPPORT AN INCREASED RISK FOR STRONG TORNADOES
--CONDITIONAL UPON STORMS MAINTAINING VIGOROUS LOW LEVEL
MESOCYCLONES.

..SMITH.. 05/20/2013

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

ATTN...WFO...FWD...OUN...

LAT...LON   33439679 33509774 33819779 34299698 34359616 33949596
            33439679

000
ACUS11 KWNS 202238
SWOMCD
SPC MCD 202238
IAZ000-MOZ000-KSZ000-202345-

MESOSCALE DISCUSSION 0733
NWS STORM PREDICTION CENTER NORMAN OK
0538 PM CDT MON MAY 20 2013

AREAS AFFECTED...NWRN MO INTO CNTRL IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 202238Z - 202345Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS APPEARS TO BE INCREASING
ACROSS THE DISCUSSION AREA AND CONVECTIVE TRENDS ARE BEING MONITORED
FOR A POSSIBLE WW.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS A BAND OF DEEPENING
CUMULUS ALONG THE SYNOPTIC COLD FRONT FROM NEAR STJ TO ALO.  THESE
DEVELOPMENTS APPEAR TO BE ASSOCIATED WITH A VORTICITY MAXIMUM AND
ASSOCIATED 60-70 KT MIDLEVEL JET STREAK TRANSLATING NEWD INTO THE
LOWER-MO VALLEY.  HERE...THE COMBINATION OF A WARM AND RELATIVELY
MOIST PBL COINCIDES WITH STEADILY COOLING MIDLEVEL TEMPERATURES TO
YIELD MODERATE INSTABILITY AMIDST A KINEMATIC ENVIRONMENT FEATURING
A VERTICALLY VEERING WIND PROFILE WITH 40-50 KT OF DEEP-LAYER SHEAR.
 SHOULD CONVECTION EVOLVE INTO TSTMS...THE POTENTIAL WILL EXIST FOR
SOME STORM ORGANIZATION THROUGH THIS EVENING WITH AN ATTENDANT RISK
FOR SEVERE HAIL AND LOCALLY DAMAGING WIND GUSTS.

..MEAD/CORFIDI.. 05/20/2013

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

ATTN...WFO...ARX...DMX...EAX...

LAT...LON   39939498 41179452 42199425 42669358 43029268 42409241
            41809260 40629354 39889438 39729476 39939498

000
ACUS11 KWNS 202238
SWOMCD
SPC MCD 202238
IAZ000-MOZ000-KSZ000-202345-

MESOSCALE DISCUSSION 0733
NWS STORM PREDICTION CENTER NORMAN OK
0538 PM CDT MON MAY 20 2013

AREAS AFFECTED...NWRN MO INTO CNTRL IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 202238Z - 202345Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS APPEARS TO BE INCREASING
ACROSS THE DISCUSSION AREA AND CONVECTIVE TRENDS ARE BEING MONITORED
FOR A POSSIBLE WW.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS A BAND OF DEEPENING
CUMULUS ALONG THE SYNOPTIC COLD FRONT FROM NEAR STJ TO ALO.  THESE
DEVELOPMENTS APPEAR TO BE ASSOCIATED WITH A VORTICITY MAXIMUM AND
ASSOCIATED 60-70 KT MIDLEVEL JET STREAK TRANSLATING NEWD INTO THE
LOWER-MO VALLEY.  HERE...THE COMBINATION OF A WARM AND RELATIVELY
MOIST PBL COINCIDES WITH STEADILY COOLING MIDLEVEL TEMPERATURES TO
YIELD MODERATE INSTABILITY AMIDST A KINEMATIC ENVIRONMENT FEATURING
A VERTICALLY VEERING WIND PROFILE WITH 40-50 KT OF DEEP-LAYER SHEAR.
 SHOULD CONVECTION EVOLVE INTO TSTMS...THE POTENTIAL WILL EXIST FOR
SOME STORM ORGANIZATION THROUGH THIS EVENING WITH AN ATTENDANT RISK
FOR SEVERE HAIL AND LOCALLY DAMAGING WIND GUSTS.

..MEAD/CORFIDI.. 05/20/2013

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

ATTN...WFO...ARX...DMX...EAX...

LAT...LON   39939498 41179452 42199425 42669358 43029268 42409241
            41809260 40629354 39889438 39729476 39939498

000
ACUS11 KWNS 202238
SWOMCD
SPC MCD 202238
IAZ000-MOZ000-KSZ000-202345-

MESOSCALE DISCUSSION 0733
NWS STORM PREDICTION CENTER NORMAN OK
0538 PM CDT MON MAY 20 2013

AREAS AFFECTED...NWRN MO INTO CNTRL IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 202238Z - 202345Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS APPEARS TO BE INCREASING
ACROSS THE DISCUSSION AREA AND CONVECTIVE TRENDS ARE BEING MONITORED
FOR A POSSIBLE WW.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS A BAND OF DEEPENING
CUMULUS ALONG THE SYNOPTIC COLD FRONT FROM NEAR STJ TO ALO.  THESE
DEVELOPMENTS APPEAR TO BE ASSOCIATED WITH A VORTICITY MAXIMUM AND
ASSOCIATED 60-70 KT MIDLEVEL JET STREAK TRANSLATING NEWD INTO THE
LOWER-MO VALLEY.  HERE...THE COMBINATION OF A WARM AND RELATIVELY
MOIST PBL COINCIDES WITH STEADILY COOLING MIDLEVEL TEMPERATURES TO
YIELD MODERATE INSTABILITY AMIDST A KINEMATIC ENVIRONMENT FEATURING
A VERTICALLY VEERING WIND PROFILE WITH 40-50 KT OF DEEP-LAYER SHEAR.
 SHOULD CONVECTION EVOLVE INTO TSTMS...THE POTENTIAL WILL EXIST FOR
SOME STORM ORGANIZATION THROUGH THIS EVENING WITH AN ATTENDANT RISK
FOR SEVERE HAIL AND LOCALLY DAMAGING WIND GUSTS.

..MEAD/CORFIDI.. 05/20/2013

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

ATTN...WFO...ARX...DMX...EAX...

LAT...LON   39939498 41179452 42199425 42669358 43029268 42409241
            41809260 40629354 39889438 39729476 39939498

000
ACUS11 KWNS 202234
SWOMCD
SPC MCD 202234
TXZ000-OKZ000-202330-

MESOSCALE DISCUSSION 0732
NWS STORM PREDICTION CENTER NORMAN OK
0534 PM CDT MON MAY 20 2013

AREAS AFFECTED...PORTIONS OF THE TX/OK RED RIVER VALLEY

CONCERNING...TORNADO WATCH 191...192...

VALID 202234Z - 202330Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 191...192...CONTINUES.

SUMMARY...THE ENVIRONMENT FOR LONG-LIVED SUPERCELLS CAPABLE OF A
STRONG TORNADO OR TWO APPEAR TO BE MAXIMIZING NEAR THE RED RIVER
OVER THE NEXT 1-2 HRS.

DISCUSSION...22Z SURFACE ANALYSIS SHOWS PRESSURE FALLS MAXIMIZING
OVER N-CNTRL TX TO THE E OF THE DRYLINE AND TEMP/DEWPOINT SPREADS
ARE BEGINNING TO LOWER IN THE 10-15 DEG RANGE...SIGNIFYING HIGHER
BOUNDARY LAYER RH AND LOWER LCLS.  ADDITIONALLY...SURFACE WINDS ARE
BEGINNING TO BACK SLIGHTLY FROM THE S TO SSE.  ALTHOUGH THE 18Z FWD
RAOB SHOWED AN INVERSION LAYER AROUND H85...THE INFLUENCE OF THIS
FEATURE WILL PROBABLY BE LESSENED THROUGH FORCED STORM-SCALE ASCENT.
 BECAUSE OF THE VERY UNSTABLE AIRMASS IN PLACE AND THE FORECAST
INCREASE IN H85 FLOW /INCREASING LOW LEVEL SHEAR/...THE TORNADO
THREAT APPEARS TO BE INCREASING.  IF THE KFWS VWP OBSERVATIONS SHOW
A SIMILAR INCREASE IN LOW LEVEL SHEAR OVER THE NEXT HOUR OR SO AS
THE VARIOUS RAP FORECAST SOUNDINGS...A STRONG TORNADO OR TWO IS
POSSIBLE IN ADDITION TO LARGE HAIL AND DMGG WINDS.

..SMITH.. 05/20/2013

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

ATTN...WFO...FWD...OUN...

LAT...LON   33709772 33769817 33949815 34259714 34179674 33829699
            33709772

000
ACUS11 KWNS 202234
SWOMCD
SPC MCD 202234
TXZ000-OKZ000-202330-

MESOSCALE DISCUSSION 0732
NWS STORM PREDICTION CENTER NORMAN OK
0534 PM CDT MON MAY 20 2013

AREAS AFFECTED...PORTIONS OF THE TX/OK RED RIVER VALLEY

CONCERNING...TORNADO WATCH 191...192...

VALID 202234Z - 202330Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 191...192...CONTINUES.

SUMMARY...THE ENVIRONMENT FOR LONG-LIVED SUPERCELLS CAPABLE OF A
STRONG TORNADO OR TWO APPEAR TO BE MAXIMIZING NEAR THE RED RIVER
OVER THE NEXT 1-2 HRS.

DISCUSSION...22Z SURFACE ANALYSIS SHOWS PRESSURE FALLS MAXIMIZING
OVER N-CNTRL TX TO THE E OF THE DRYLINE AND TEMP/DEWPOINT SPREADS
ARE BEGINNING TO LOWER IN THE 10-15 DEG RANGE...SIGNIFYING HIGHER
BOUNDARY LAYER RH AND LOWER LCLS.  ADDITIONALLY...SURFACE WINDS ARE
BEGINNING TO BACK SLIGHTLY FROM THE S TO SSE.  ALTHOUGH THE 18Z FWD
RAOB SHOWED AN INVERSION LAYER AROUND H85...THE INFLUENCE OF THIS
FEATURE WILL PROBABLY BE LESSENED THROUGH FORCED STORM-SCALE ASCENT.
 BECAUSE OF THE VERY UNSTABLE AIRMASS IN PLACE AND THE FORECAST
INCREASE IN H85 FLOW /INCREASING LOW LEVEL SHEAR/...THE TORNADO
THREAT APPEARS TO BE INCREASING.  IF THE KFWS VWP OBSERVATIONS SHOW
A SIMILAR INCREASE IN LOW LEVEL SHEAR OVER THE NEXT HOUR OR SO AS
THE VARIOUS RAP FORECAST SOUNDINGS...A STRONG TORNADO OR TWO IS
POSSIBLE IN ADDITION TO LARGE HAIL AND DMGG WINDS.

..SMITH.. 05/20/2013

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

ATTN...WFO...FWD...OUN...

LAT...LON   33709772 33769817 33949815 34259714 34179674 33829699
            33709772

000
ACUS11 KWNS 202207
SWOMCD
SPC MCD 202207
ILZ000-MOZ000-202230-

MESOSCALE DISCUSSION 0731
NWS STORM PREDICTION CENTER NORMAN OK
0507 PM CDT MON MAY 20 2013

AREAS AFFECTED...ERN MO / W-CNTRL IL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 202207Z - 202230Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS...INCLUDING THE POSSIBILITY
OF A TORNADO APPEARS TO BE INCREASING.  A WATCH ISSUANCE WILL NEED
TO BE CONSIDERED WITHIN THE NEXT 30-60 MINUTES.

DISCUSSION...SURFACE/SATELLITE COMPOSITE SHOWS AN A REMNANT OUTFLOW
SIGNIFYING A LESS UNSTABLE AIRMASS OVER CNTRL IL WHERE CU
DEVELOPMENT HAS BEEN LIMITED THIS AFTERNOON.  FARTHER S AND
SW...RICHER BOUNDARY LAYER MOISTURE NEAR THE ST. LOUIS METRO AND
OVER THE OZARKS MAY GRADUALLY MOVE NWD OVER THE I-70 CORRIDOR.
ALTHOUGH CURRENT KLSX VWP DATA SHOWS SOMEWHAT STUNTED LOW LEVEL
SHEAR /15-20 KT/...MODELS HINT AT H85 SLIGHTLY INCREASING THIS
EVENING.  AN ISOLD LARGE HAIL/DMGG WIND THREAT SEEMS TO BE THE MOST
LIKELY THREAT...BUT LOCATIONS WHERE RICHER MOISTURE/INSTABILITY
/MAINLY NEAR AND S OF I-70/ MAY HAVE SOME TORNADO THREAT THIS
EVENING AS STORMS MOVE INTO THE REGION.

..SMITH/CORFIDI.. 05/20/2013

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

ATTN...WFO...ILX...LSX...DVN...SGF...

LAT...LON   39569223 40179112 40419008 40178953 39338945 38479016
            37899142 39569223

000
ACUS11 KWNS 202207
SWOMCD
SPC MCD 202207
ILZ000-MOZ000-202230-

MESOSCALE DISCUSSION 0731
NWS STORM PREDICTION CENTER NORMAN OK
0507 PM CDT MON MAY 20 2013

AREAS AFFECTED...ERN MO / W-CNTRL IL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 202207Z - 202230Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS...INCLUDING THE POSSIBILITY
OF A TORNADO APPEARS TO BE INCREASING.  A WATCH ISSUANCE WILL NEED
TO BE CONSIDERED WITHIN THE NEXT 30-60 MINUTES.

DISCUSSION...SURFACE/SATELLITE COMPOSITE SHOWS AN A REMNANT OUTFLOW
SIGNIFYING A LESS UNSTABLE AIRMASS OVER CNTRL IL WHERE CU
DEVELOPMENT HAS BEEN LIMITED THIS AFTERNOON.  FARTHER S AND
SW...RICHER BOUNDARY LAYER MOISTURE NEAR THE ST. LOUIS METRO AND
OVER THE OZARKS MAY GRADUALLY MOVE NWD OVER THE I-70 CORRIDOR.
ALTHOUGH CURRENT KLSX VWP DATA SHOWS SOMEWHAT STUNTED LOW LEVEL
SHEAR /15-20 KT/...MODELS HINT AT H85 SLIGHTLY INCREASING THIS
EVENING.  AN ISOLD LARGE HAIL/DMGG WIND THREAT SEEMS TO BE THE MOST
LIKELY THREAT...BUT LOCATIONS WHERE RICHER MOISTURE/INSTABILITY
/MAINLY NEAR AND S OF I-70/ MAY HAVE SOME TORNADO THREAT THIS
EVENING AS STORMS MOVE INTO THE REGION.

..SMITH/CORFIDI.. 05/20/2013

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

ATTN...WFO...ILX...LSX...DVN...SGF...

LAT...LON   39569223 40179112 40419008 40178953 39338945 38479016
            37899142 39569223

000
ACUS11 KWNS 202207
SWOMCD
SPC MCD 202207
ILZ000-MOZ000-202230-

MESOSCALE DISCUSSION 0731
NWS STORM PREDICTION CENTER NORMAN OK
0507 PM CDT MON MAY 20 2013

AREAS AFFECTED...ERN MO / W-CNTRL IL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 202207Z - 202230Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE THREAT FOR SEVERE STORMS...INCLUDING THE POSSIBILITY
OF A TORNADO APPEARS TO BE INCREASING.  A WATCH ISSUANCE WILL NEED
TO BE CONSIDERED WITHIN THE NEXT 30-60 MINUTES.

DISCUSSION...SURFACE/SATELLITE COMPOSITE SHOWS AN A REMNANT OUTFLOW
SIGNIFYING A LESS UNSTABLE AIRMASS OVER CNTRL IL WHERE CU
DEVELOPMENT HAS BEEN LIMITED THIS AFTERNOON.  FARTHER S AND
SW...RICHER BOUNDARY LAYER MOISTURE NEAR THE ST. LOUIS METRO AND
OVER THE OZARKS MAY GRADUALLY MOVE NWD OVER THE I-70 CORRIDOR.
ALTHOUGH CURRENT KLSX VWP DATA SHOWS SOMEWHAT STUNTED LOW LEVEL
SHEAR /15-20 KT/...MODELS HINT AT H85 SLIGHTLY INCREASING THIS
EVENING.  AN ISOLD LARGE HAIL/DMGG WIND THREAT SEEMS TO BE THE MOST
LIKELY THREAT...BUT LOCATIONS WHERE RICHER MOISTURE/INSTABILITY
/MAINLY NEAR AND S OF I-70/ MAY HAVE SOME TORNADO THREAT THIS
EVENING AS STORMS MOVE INTO THE REGION.

..SMITH/CORFIDI.. 05/20/2013

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

ATTN...WFO...ILX...LSX...DVN...SGF...

LAT...LON   39569223 40179112 40419008 40178953 39338945 38479016
            37899142 39569223

000
ACUS11 KWNS 202204
SWOMCD
SPC MCD 202203 COR
MIZ000-202300-

MESOSCALE DISCUSSION 0730
NWS STORM PREDICTION CENTER NORMAN OK
0503 PM CDT MON MAY 20 2013

AREAS AFFECTED...ERN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 189...

VALID 202203Z - 202300Z

CORRECTED FOR MD LOCATION ERROR

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 189
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND HAIL CONTINUES ACROSS
ERN PORTIONS OF THE WATCH AREA.

DISCUSSION...AS OF 2146Z...REGIONAL RADAR IMAGERY SHOWED A QLCS
EXTENDING FROM APPROXIMATELY 60 ESE ANJ TO 20 NW JXN WITH A SYSTEM
MOTION OF 265/35 KT.  THUS FAR...THE MOST PROGRESSIVE PORTION OF
QLCS HAS BEEN LOCATED TO THE N OF MBS WHERE A MORE EXPANSIVE
TRAILING STRATIFORM REGION HAS DEVELOPED...LIKELY IN CONJUNCTION
WITH THE FORMATION OF A REAR INFLOW JET.  FARTHER TO THE
S...CONVECTION HAS STRUGGLED TO BECOME ESTABLISHED...PERHAPS AS A
RESULTING OF WEAK LOW-LEVEL CONVERGENCE.  DOWNSTREAM AIR MASS ACROSS
E-CNTRL AND SERN LOWER MI REMAINS SUPPORTIVE OF ORGANIZED SEVERE
STORMS WITH MODERATE INSTABILITY AND A VERTICALLY VEERING WIND
PROFILE WITH 50 KT WSWLY WINDS OBSERVED AT 4 KM AGL...PER DTX VAD.

RECENT CONVECTION-ALLOWING MODEL GUIDANCE SUGGESTS THAT STORMS MAY
CONTINUE TO STRUGGLE ALONG THE SRN EXTENSION OF THE QLCS...GENERALLY
ALONG AND S OF THE I-94 CORRIDOR.  OTHERWISE...EXPECT THE POTENTIAL
FOR DAMAGING WINDS AND HAIL TO PERSIST WHERE STORMS CAN PERSIST.

..MEAD.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42298491 43728407 44508340 44498318 43828258 42788254
            42168291 41848307 41978390 42068466 42298491

000
ACUS11 KWNS 202204
SWOMCD
SPC MCD 202203 COR
MIZ000-202300-

MESOSCALE DISCUSSION 0730
NWS STORM PREDICTION CENTER NORMAN OK
0503 PM CDT MON MAY 20 2013

AREAS AFFECTED...ERN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 189...

VALID 202203Z - 202300Z

CORRECTED FOR MD LOCATION ERROR

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 189
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND HAIL CONTINUES ACROSS
ERN PORTIONS OF THE WATCH AREA.

DISCUSSION...AS OF 2146Z...REGIONAL RADAR IMAGERY SHOWED A QLCS
EXTENDING FROM APPROXIMATELY 60 ESE ANJ TO 20 NW JXN WITH A SYSTEM
MOTION OF 265/35 KT.  THUS FAR...THE MOST PROGRESSIVE PORTION OF
QLCS HAS BEEN LOCATED TO THE N OF MBS WHERE A MORE EXPANSIVE
TRAILING STRATIFORM REGION HAS DEVELOPED...LIKELY IN CONJUNCTION
WITH THE FORMATION OF A REAR INFLOW JET.  FARTHER TO THE
S...CONVECTION HAS STRUGGLED TO BECOME ESTABLISHED...PERHAPS AS A
RESULTING OF WEAK LOW-LEVEL CONVERGENCE.  DOWNSTREAM AIR MASS ACROSS
E-CNTRL AND SERN LOWER MI REMAINS SUPPORTIVE OF ORGANIZED SEVERE
STORMS WITH MODERATE INSTABILITY AND A VERTICALLY VEERING WIND
PROFILE WITH 50 KT WSWLY WINDS OBSERVED AT 4 KM AGL...PER DTX VAD.

RECENT CONVECTION-ALLOWING MODEL GUIDANCE SUGGESTS THAT STORMS MAY
CONTINUE TO STRUGGLE ALONG THE SRN EXTENSION OF THE QLCS...GENERALLY
ALONG AND S OF THE I-94 CORRIDOR.  OTHERWISE...EXPECT THE POTENTIAL
FOR DAMAGING WINDS AND HAIL TO PERSIST WHERE STORMS CAN PERSIST.

..MEAD.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42298491 43728407 44508340 44498318 43828258 42788254
            42168291 41848307 41978390 42068466 42298491

000
ACUS11 KWNS 202204
SWOMCD
SPC MCD 202203 COR
MIZ000-202300-

MESOSCALE DISCUSSION 0730
NWS STORM PREDICTION CENTER NORMAN OK
0503 PM CDT MON MAY 20 2013

AREAS AFFECTED...ERN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 189...

VALID 202203Z - 202300Z

CORRECTED FOR MD LOCATION ERROR

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 189
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND HAIL CONTINUES ACROSS
ERN PORTIONS OF THE WATCH AREA.

DISCUSSION...AS OF 2146Z...REGIONAL RADAR IMAGERY SHOWED A QLCS
EXTENDING FROM APPROXIMATELY 60 ESE ANJ TO 20 NW JXN WITH A SYSTEM
MOTION OF 265/35 KT.  THUS FAR...THE MOST PROGRESSIVE PORTION OF
QLCS HAS BEEN LOCATED TO THE N OF MBS WHERE A MORE EXPANSIVE
TRAILING STRATIFORM REGION HAS DEVELOPED...LIKELY IN CONJUNCTION
WITH THE FORMATION OF A REAR INFLOW JET.  FARTHER TO THE
S...CONVECTION HAS STRUGGLED TO BECOME ESTABLISHED...PERHAPS AS A
RESULTING OF WEAK LOW-LEVEL CONVERGENCE.  DOWNSTREAM AIR MASS ACROSS
E-CNTRL AND SERN LOWER MI REMAINS SUPPORTIVE OF ORGANIZED SEVERE
STORMS WITH MODERATE INSTABILITY AND A VERTICALLY VEERING WIND
PROFILE WITH 50 KT WSWLY WINDS OBSERVED AT 4 KM AGL...PER DTX VAD.

RECENT CONVECTION-ALLOWING MODEL GUIDANCE SUGGESTS THAT STORMS MAY
CONTINUE TO STRUGGLE ALONG THE SRN EXTENSION OF THE QLCS...GENERALLY
ALONG AND S OF THE I-94 CORRIDOR.  OTHERWISE...EXPECT THE POTENTIAL
FOR DAMAGING WINDS AND HAIL TO PERSIST WHERE STORMS CAN PERSIST.

..MEAD.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42298491 43728407 44508340 44498318 43828258 42788254
            42168291 41848307 41978390 42068466 42298491

000
ACUS11 KWNS 202200
SWOMCD
SPC MCD 202159
MIZ000-202300-

MESOSCALE DISCUSSION 0730
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT MON MAY 20 2013

AREAS
AFFECTED...222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222ERN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 189...

VALID 202159Z - 202300Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 189
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND HAIL CONTINUES ACROSS
ERN PORTIONS OF THE WATCH AREA.

DISCUSSION...AS OF 2146Z...REGIONAL RADAR IMAGERY SHOWED A QLCS
EXTENDING FROM APPROXIMATELY 60 ESE ANJ TO 20 NW JXN WITH A SYSTEM
MOTION OF 265/35 KT.  THUS FAR...THE MOST PROGRESSIVE PORTION OF
QLCS HAS BEEN LOCATED TO THE N OF MBS WHERE A MORE EXPANSIVE
TRAILING STRATIFORM REGION HAS DEVELOPED...LIKELY IN CONJUNCTION
WITH THE FORMATION OF A REAR INFLOW JET.  FARTHER TO THE
S...CONVECTION HAS STRUGGLED TO BECOME ESTABLISHED...PERHAPS AS A
RESULTING OF WEAK LOW-LEVEL CONVERGENCE.  DOWNSTREAM AIR MASS ACROSS
E-CNTRL AND SERN LOWER MI REMAINS SUPPORTIVE OF ORGANIZED SEVERE
STORMS WITH MODERATE INSTABILITY AND A VERTICALLY VEERING WIND
PROFILE WITH 50 KT WSWLY WINDS OBSERVED AT 4 KM AGL...PER DTX VAD.

RECENT CONVECTION-ALLOWING MODEL GUIDANCE SUGGESTS THAT STORMS MAY
CONTINUE TO STRUGGLE ALONG THE SRN EXTENSION OF THE QLCS...GENERALLY
ALONG AND S OF THE I-94 CORRIDOR.  OTHERWISE...EXPECT THE POTENTIAL
FOR DAMAGING WINDS AND HAIL TO PERSIST WHERE STORMS CAN PERSIST.

..MEAD.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42298491 43728407 44508340 44498318 43828258 42788254
            42168291 41848307 41978390 42068466 42298491

000
ACUS11 KWNS 202200
SWOMCD
SPC MCD 202159
MIZ000-202300-

MESOSCALE DISCUSSION 0730
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT MON MAY 20 2013

AREAS
AFFECTED...222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222ERN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 189...

VALID 202159Z - 202300Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 189
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND HAIL CONTINUES ACROSS
ERN PORTIONS OF THE WATCH AREA.

DISCUSSION...AS OF 2146Z...REGIONAL RADAR IMAGERY SHOWED A QLCS
EXTENDING FROM APPROXIMATELY 60 ESE ANJ TO 20 NW JXN WITH A SYSTEM
MOTION OF 265/35 KT.  THUS FAR...THE MOST PROGRESSIVE PORTION OF
QLCS HAS BEEN LOCATED TO THE N OF MBS WHERE A MORE EXPANSIVE
TRAILING STRATIFORM REGION HAS DEVELOPED...LIKELY IN CONJUNCTION
WITH THE FORMATION OF A REAR INFLOW JET.  FARTHER TO THE
S...CONVECTION HAS STRUGGLED TO BECOME ESTABLISHED...PERHAPS AS A
RESULTING OF WEAK LOW-LEVEL CONVERGENCE.  DOWNSTREAM AIR MASS ACROSS
E-CNTRL AND SERN LOWER MI REMAINS SUPPORTIVE OF ORGANIZED SEVERE
STORMS WITH MODERATE INSTABILITY AND A VERTICALLY VEERING WIND
PROFILE WITH 50 KT WSWLY WINDS OBSERVED AT 4 KM AGL...PER DTX VAD.

RECENT CONVECTION-ALLOWING MODEL GUIDANCE SUGGESTS THAT STORMS MAY
CONTINUE TO STRUGGLE ALONG THE SRN EXTENSION OF THE QLCS...GENERALLY
ALONG AND S OF THE I-94 CORRIDOR.  OTHERWISE...EXPECT THE POTENTIAL
FOR DAMAGING WINDS AND HAIL TO PERSIST WHERE STORMS CAN PERSIST.

..MEAD.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42298491 43728407 44508340 44498318 43828258 42788254
            42168291 41848307 41978390 42068466 42298491

000
ACUS11 KWNS 202200
SWOMCD
SPC MCD 202159
MIZ000-202300-

MESOSCALE DISCUSSION 0730
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT MON MAY 20 2013

AREAS
AFFECTED...222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222222222222222222222222222
22222222222222222222222222222222222222222222ERN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 189...

VALID 202159Z - 202300Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 189
CONTINUES.

SUMMARY...THE THREAT FOR DAMAGING WINDS AND HAIL CONTINUES ACROSS
ERN PORTIONS OF THE WATCH AREA.

DISCUSSION...AS OF 2146Z...REGIONAL RADAR IMAGERY SHOWED A QLCS
EXTENDING FROM APPROXIMATELY 60 ESE ANJ TO 20 NW JXN WITH A SYSTEM
MOTION OF 265/35 KT.  THUS FAR...THE MOST PROGRESSIVE PORTION OF
QLCS HAS BEEN LOCATED TO THE N OF MBS WHERE A MORE EXPANSIVE
TRAILING STRATIFORM REGION HAS DEVELOPED...LIKELY IN CONJUNCTION
WITH THE FORMATION OF A REAR INFLOW JET.  FARTHER TO THE
S...CONVECTION HAS STRUGGLED TO BECOME ESTABLISHED...PERHAPS AS A
RESULTING OF WEAK LOW-LEVEL CONVERGENCE.  DOWNSTREAM AIR MASS ACROSS
E-CNTRL AND SERN LOWER MI REMAINS SUPPORTIVE OF ORGANIZED SEVERE
STORMS WITH MODERATE INSTABILITY AND A VERTICALLY VEERING WIND
PROFILE WITH 50 KT WSWLY WINDS OBSERVED AT 4 KM AGL...PER DTX VAD.

RECENT CONVECTION-ALLOWING MODEL GUIDANCE SUGGESTS THAT STORMS MAY
CONTINUE TO STRUGGLE ALONG THE SRN EXTENSION OF THE QLCS...GENERALLY
ALONG AND S OF THE I-94 CORRIDOR.  OTHERWISE...EXPECT THE POTENTIAL
FOR DAMAGING WINDS AND HAIL TO PERSIST WHERE STORMS CAN PERSIST.

..MEAD.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42298491 43728407 44508340 44498318 43828258 42788254
            42168291 41848307 41978390 42068466 42298491

000
ACUS11 KWNS 202027
SWOMCD
SPC MCD 202027
INZ000-ILZ000-MOZ000-202130-

MESOSCALE DISCUSSION 0729
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT MON MAY 20 2013

AREAS AFFECTED...NERN MO...CNTRL IL...W-CNTRL IND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 202027Z - 202130Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...PROSPECTS FOR TSTM DEVELOPMENT ARE SOMEWHAT UNCERTAIN
ACROSS W-CNTRL IND WWD INTO NERN MO...BUT THE ENVIRONMENT IS
FAVORABLE FOR DMGG WINDS AND HAIL GIVEN STRONG
HEATING/DESTABILIZATION.  CONVECTIVE TRENDS ARE BEING MONITORED FOR
A POSSIBLE WW...PARTICULARLY ACTIVITY DEVELOPING NEWD FROM SWRN MO
TOWARDS THE MID-MS VALLEY.

DISCUSSION...RADAR/SATELLITE TRENDS SHOW A DECAYING TSTM CLUSTER/MCV
MOVING ACROSS N-CNTRL IL...WITH AN INCREASE IN SHALLOW BOUNDARY
LAYER CU NOTED ACROSS E-CNTRL IL. THIS APPEARS TO BE DEVELOPING
WITHIN A WEAK CONFLUENCE AXIS WHICH EXTENDS FROM 30 SE MMO TO 20 SSW
SPI. BOTH MODIFIED 12Z RAOBS AND 12Z NAM FORECAST SOUNDINGS SUGGEST
MLCAPE VALUES HAVE INCREASED TO 1000-1500 J/KG. WHILE THERE IS STILL
SOME UNCERTAINTY TO WHAT DEGREE TSTMS WILL INTENSIFY/ORGANIZE OVER
IL...A THREAT FOR DMGG WINDS AND LARGE HAIL COULD DEVELOP GIVEN
STEEP LOW-LEVEL LAPSE RATES AND MODERATELY STRONG DEEP-LAYER SHEAR.
ADDITIONALLY...TSTMS CURRENTLY DEVELOPING OVER WRN MO SHOULD
EXPAND/DEVELOP NEWD TOWARDS E-CNTRL MO THROUGH LATE AFTERNOON. IT IS
UNCERTAIN WHETHER A WW WILL BE REQUIRED WITHIN THE NEXT 1-2
HRS...BUT CONVECTIVE TRENDS CONTINUE TO BE MONITORED.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...IWX...IND...LOT...ILX...LSX...

LAT...LON   39918754 39488867 39078960 38749051 38819154 39059224
            39719220 40199029 40468932 40988874 41188822 41298728
            41208691 40788656 40298664 39918754

000
ACUS11 KWNS 202027
SWOMCD
SPC MCD 202027
INZ000-ILZ000-MOZ000-202130-

MESOSCALE DISCUSSION 0729
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT MON MAY 20 2013

AREAS AFFECTED...NERN MO...CNTRL IL...W-CNTRL IND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 202027Z - 202130Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...PROSPECTS FOR TSTM DEVELOPMENT ARE SOMEWHAT UNCERTAIN
ACROSS W-CNTRL IND WWD INTO NERN MO...BUT THE ENVIRONMENT IS
FAVORABLE FOR DMGG WINDS AND HAIL GIVEN STRONG
HEATING/DESTABILIZATION.  CONVECTIVE TRENDS ARE BEING MONITORED FOR
A POSSIBLE WW...PARTICULARLY ACTIVITY DEVELOPING NEWD FROM SWRN MO
TOWARDS THE MID-MS VALLEY.

DISCUSSION...RADAR/SATELLITE TRENDS SHOW A DECAYING TSTM CLUSTER/MCV
MOVING ACROSS N-CNTRL IL...WITH AN INCREASE IN SHALLOW BOUNDARY
LAYER CU NOTED ACROSS E-CNTRL IL. THIS APPEARS TO BE DEVELOPING
WITHIN A WEAK CONFLUENCE AXIS WHICH EXTENDS FROM 30 SE MMO TO 20 SSW
SPI. BOTH MODIFIED 12Z RAOBS AND 12Z NAM FORECAST SOUNDINGS SUGGEST
MLCAPE VALUES HAVE INCREASED TO 1000-1500 J/KG. WHILE THERE IS STILL
SOME UNCERTAINTY TO WHAT DEGREE TSTMS WILL INTENSIFY/ORGANIZE OVER
IL...A THREAT FOR DMGG WINDS AND LARGE HAIL COULD DEVELOP GIVEN
STEEP LOW-LEVEL LAPSE RATES AND MODERATELY STRONG DEEP-LAYER SHEAR.
ADDITIONALLY...TSTMS CURRENTLY DEVELOPING OVER WRN MO SHOULD
EXPAND/DEVELOP NEWD TOWARDS E-CNTRL MO THROUGH LATE AFTERNOON. IT IS
UNCERTAIN WHETHER A WW WILL BE REQUIRED WITHIN THE NEXT 1-2
HRS...BUT CONVECTIVE TRENDS CONTINUE TO BE MONITORED.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...IWX...IND...LOT...ILX...LSX...

LAT...LON   39918754 39488867 39078960 38749051 38819154 39059224
            39719220 40199029 40468932 40988874 41188822 41298728
            41208691 40788656 40298664 39918754

000
ACUS11 KWNS 202027
SWOMCD
SPC MCD 202027
INZ000-ILZ000-MOZ000-202130-

MESOSCALE DISCUSSION 0729
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT MON MAY 20 2013

AREAS AFFECTED...NERN MO...CNTRL IL...W-CNTRL IND

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 202027Z - 202130Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...PROSPECTS FOR TSTM DEVELOPMENT ARE SOMEWHAT UNCERTAIN
ACROSS W-CNTRL IND WWD INTO NERN MO...BUT THE ENVIRONMENT IS
FAVORABLE FOR DMGG WINDS AND HAIL GIVEN STRONG
HEATING/DESTABILIZATION.  CONVECTIVE TRENDS ARE BEING MONITORED FOR
A POSSIBLE WW...PARTICULARLY ACTIVITY DEVELOPING NEWD FROM SWRN MO
TOWARDS THE MID-MS VALLEY.

DISCUSSION...RADAR/SATELLITE TRENDS SHOW A DECAYING TSTM CLUSTER/MCV
MOVING ACROSS N-CNTRL IL...WITH AN INCREASE IN SHALLOW BOUNDARY
LAYER CU NOTED ACROSS E-CNTRL IL. THIS APPEARS TO BE DEVELOPING
WITHIN A WEAK CONFLUENCE AXIS WHICH EXTENDS FROM 30 SE MMO TO 20 SSW
SPI. BOTH MODIFIED 12Z RAOBS AND 12Z NAM FORECAST SOUNDINGS SUGGEST
MLCAPE VALUES HAVE INCREASED TO 1000-1500 J/KG. WHILE THERE IS STILL
SOME UNCERTAINTY TO WHAT DEGREE TSTMS WILL INTENSIFY/ORGANIZE OVER
IL...A THREAT FOR DMGG WINDS AND LARGE HAIL COULD DEVELOP GIVEN
STEEP LOW-LEVEL LAPSE RATES AND MODERATELY STRONG DEEP-LAYER SHEAR.
ADDITIONALLY...TSTMS CURRENTLY DEVELOPING OVER WRN MO SHOULD
EXPAND/DEVELOP NEWD TOWARDS E-CNTRL MO THROUGH LATE AFTERNOON. IT IS
UNCERTAIN WHETHER A WW WILL BE REQUIRED WITHIN THE NEXT 1-2
HRS...BUT CONVECTIVE TRENDS CONTINUE TO BE MONITORED.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...IWX...IND...LOT...ILX...LSX...

LAT...LON   39918754 39488867 39078960 38749051 38819154 39059224
            39719220 40199029 40468932 40988874 41188822 41298728
            41208691 40788656 40298664 39918754

000
ACUS01 KWNS 201959
SWODY1
SPC AC 201957

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0257 PM CDT MON MAY 20 2013

VALID 202000Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER NORTH CENTRAL
TX...CENTRAL/ERN OK...EXTREME SERN KS...SRN MO...AND NWRN AR...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS INTO THE
GREAT LAKES REGION...

...SRN PLAINS INTO THE OZARKS...
MINOR ADJUSTMENTS HAVE BEEN MADE TO THE OUTLOOK BASED ON CURRENT
BOUNDARY LOCATIONS AND RECENT CONVECTIVE INITIATION.

SEVERE STORMS HAVE DEVELOPED ALONG THE DRY LINE FROM THE WRN PART OF
NORTH TEXAS INTO CENTRAL OK...WITH ADDITIONAL STORMS OVER SERN KS
AND SWRN MO.  SPECIAL SOUNDINGS AT 17-18Z FROM OUN/SGF/FWD INDICATE
STEEP LAPSE RATES ARE PERSISTING ABOVE 850 MB THAT ARE ASSOCIATED
WITH THE ELEVATED MIXED LAYER ACROSS THE REGION.  WITH SURFACE
DEWPOINTS IN THE UPPER 60S/LOWER 70S AND TEMPERATURES WARMING INTO
THE LOW/MID 80S IN OK AND NEAR 90 IN NRN TX...A VERY UNSTABLE
ENVIRONMENT IS PRESENT WITH SBCAPE RANGING FROM 3500-5000 J/KG. DEEP
LAYER SHEAR OF 40-50 KT WILL ENHANCE STORM ORGANIZATION AND
INTENSITY WITH POTENTIAL FOR SUPERCELLS AND BOWING LINE SEGMENTS.
VERY LARGE HAIL...DAMAGING WIND AND SEVERAL STRONG TORNADOES WILL BE
POSSIBLE THROUGH THE EVENING AS ACTIVITY CONTINUES TO DEVELOP AND
SPREAD EWD/NEWD.

...GA/FL...
STRONGER STORMS APPEAR MOST LIKELY FROM SRN GA AND NRN FL INTO THE
SWRN PART OF THE FL PENINSULA...IN ASSOCIATION WITH AN UPPER LOW
OVER SRN GA/NRN FL.  ISOLATED MARGINAL HAIL AND WET MICROBURSTS MAY
ACCOMPANY A FEW OF THE CELLS BUT OVERALL SEVERE THREAT SHOULD BE
LIMITED.

..WEISS.. 05/20/2013

.PREV DISCUSSION... /ISSUED 1130 AM CDT MON MAY 20 2013/

...SRN PLAINS TO OZARK PLATEAU...
OVERALL FORECAST SCENARIO REMAINS SIMILAR TO EARLIER OUTLOOKS WITH
ONLY MINOR OVERALL CHANGES TO INDIVIDUAL HAZARD PROBABILITIES.
MID-LEVEL SPEED MAX /65 KT AT 500 MB IN THE 12Z ABQ RAOB/ ATTENDANT
TO THE SHORTWAVE IMPULSE OVER THE LEE OF THE SRN ROCKIES WILL
OVERSPREAD MOST OF OK TO THE LOWER MO VALLEY BY EARLY EVENING.
TRAILING PORTION OF COLD FRONT HAS BECOME SLOW-MOVING FROM SERN KS
TO SWRN OK...INTERSECTING A DRYLINE THAT WILL BECOME WELL
ESTABLISHED S/SWWD ACROSS THE TX BIG COUNTRY TO THE ERN EDWARDS
PLATEAU BY LATE AFTERNOON. SCATTERED TSTMS WILL INITIATE ALONG THESE
BOUNDARIES BY MID-AFTERNOON. MORNING CONVECTION-ALLOWING MODEL
GUIDANCE ARE INSISTENT THAT THIS ACTIVITY WILL RAPIDLY GROW UPSCALE
INTO NUMEROUS LINE SEGMENTS...SURGING EWD THIS EVENING WITHIN A
STRONGLY UNSTABLE ENVIRONMENT.

INITIAL TSTMS WILL BECOME SUPERCELLUAR QUICKLY WITH VERY LARGE HAIL
LIKELY AS HODOGRAPHS/INSTABILITY WILL BE QUITE FAVORABLE...ALONG
WITH A FEW TORNADOES. THE GREATEST RISK FOR A COUPLE OF STRONG
TORNADOES SHOULD EXIST FROM S-CNTRL INTO E-CNTRL OK. BUT WITH
PREDOMINANT SWLY COMPONENT TO LOW-LEVEL FLOW AND MODERATE 0-1 KM
SHEAR...OVERALL TORNADO INTENSITY/LONGEVITY MAY BE
TEMPERED...ESPECIALLY WITH CONVECTION EXPECTED TO GROW UPSCALE SO
QUICKLY. NEVERTHELESS...THIS GROWTH SHOULD YIELD BOWING LINEAR
SEGMENTS CAPABLE OF SWATHS OF WIDESPREAD DAMAGING WINDS...LARGE HAIL
AND A FEW TORNADOES.

...MID/UPPER-MS VALLEY TO CNTRL GREAT LAKES...
PRIMARY CHANGE HAS BEEN TO EXPAND DAMAGING WIND PROBABILITIES E/NEWD
FOR THIS AFTERNOON AND EVENING. IN THE WAKE OF CONVECTION
YESTERDAY...LOW-LEVEL MOISTURE PLUME HAS BECOME CONFINED FROM LOWER
MI S/SSWD TO THE CONFLUENCE OF THE MS/OH RIVERS. BUT PLENTIFUL
HEATING IS OCCURRING TO THE N OF THIS PLUME WILL YIELD A RECOVERING
AIR MASS DOWNSTREAM OF A TSTM CLUSTER APPROACHING CNTRL MO. THIS
ACTIVITY SHOULD GROW UPSCALE ALONG THE EDGE OF THE INSTABILITY
AXIS...WITH ADDITIONAL LINEAR SEGMENTS EMANATING E/NEWD FROM THE
OZARK PLATEAU LATER TODAY. SWATHS OF DAMAGING WINDS...LARGE HAIL AND
A COUPLE OF TORNADOES WILL BE POSSIBLE.

FARTHER N/NW...SCATTERED TSTMS ARE EXPECTED TO FORM OVER LOWER MI
AND IN PARTS OF THE UPPER MIDWEST IN ASSOCIATION WITH AN UPPER-LEVEL
LOW CENTERED OVER ERN SD. BUOYANCY WILL BE STRONGEST OVER LOWER MI
WITHIN THE LOW-LEVEL MOISTURE PLUME CHARACTERIZED BY MIDDLE TO UPPER
60S SURFACE DEW POINTS. IN THE UPPER MIDWEST...POCKETS OF ROBUST
SURFACE HEATING WILL SUPPORT AT LEAST MODEST INSTABILITY AND WITH
STRONG UNIDIRECTIONAL WIND PROFILES...SETUP COULD A FEW ORGANIZED
TSTM CLUSTERS. A MIX OF ISOLATED SEVERE HAIL/WIND SHOULD BE THE
PRIMARY THREATS.

000
ACUS01 KWNS 201959
SWODY1
SPC AC 201957

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0257 PM CDT MON MAY 20 2013

VALID 202000Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER NORTH CENTRAL
TX...CENTRAL/ERN OK...EXTREME SERN KS...SRN MO...AND NWRN AR...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS INTO THE
GREAT LAKES REGION...

...SRN PLAINS INTO THE OZARKS...
MINOR ADJUSTMENTS HAVE BEEN MADE TO THE OUTLOOK BASED ON CURRENT
BOUNDARY LOCATIONS AND RECENT CONVECTIVE INITIATION.

SEVERE STORMS HAVE DEVELOPED ALONG THE DRY LINE FROM THE WRN PART OF
NORTH TEXAS INTO CENTRAL OK...WITH ADDITIONAL STORMS OVER SERN KS
AND SWRN MO.  SPECIAL SOUNDINGS AT 17-18Z FROM OUN/SGF/FWD INDICATE
STEEP LAPSE RATES ARE PERSISTING ABOVE 850 MB THAT ARE ASSOCIATED
WITH THE ELEVATED MIXED LAYER ACROSS THE REGION.  WITH SURFACE
DEWPOINTS IN THE UPPER 60S/LOWER 70S AND TEMPERATURES WARMING INTO
THE LOW/MID 80S IN OK AND NEAR 90 IN NRN TX...A VERY UNSTABLE
ENVIRONMENT IS PRESENT WITH SBCAPE RANGING FROM 3500-5000 J/KG. DEEP
LAYER SHEAR OF 40-50 KT WILL ENHANCE STORM ORGANIZATION AND
INTENSITY WITH POTENTIAL FOR SUPERCELLS AND BOWING LINE SEGMENTS.
VERY LARGE HAIL...DAMAGING WIND AND SEVERAL STRONG TORNADOES WILL BE
POSSIBLE THROUGH THE EVENING AS ACTIVITY CONTINUES TO DEVELOP AND
SPREAD EWD/NEWD.

...GA/FL...
STRONGER STORMS APPEAR MOST LIKELY FROM SRN GA AND NRN FL INTO THE
SWRN PART OF THE FL PENINSULA...IN ASSOCIATION WITH AN UPPER LOW
OVER SRN GA/NRN FL.  ISOLATED MARGINAL HAIL AND WET MICROBURSTS MAY
ACCOMPANY A FEW OF THE CELLS BUT OVERALL SEVERE THREAT SHOULD BE
LIMITED.

..WEISS.. 05/20/2013

.PREV DISCUSSION... /ISSUED 1130 AM CDT MON MAY 20 2013/

...SRN PLAINS TO OZARK PLATEAU...
OVERALL FORECAST SCENARIO REMAINS SIMILAR TO EARLIER OUTLOOKS WITH
ONLY MINOR OVERALL CHANGES TO INDIVIDUAL HAZARD PROBABILITIES.
MID-LEVEL SPEED MAX /65 KT AT 500 MB IN THE 12Z ABQ RAOB/ ATTENDANT
TO THE SHORTWAVE IMPULSE OVER THE LEE OF THE SRN ROCKIES WILL
OVERSPREAD MOST OF OK TO THE LOWER MO VALLEY BY EARLY EVENING.
TRAILING PORTION OF COLD FRONT HAS BECOME SLOW-MOVING FROM SERN KS
TO SWRN OK...INTERSECTING A DRYLINE THAT WILL BECOME WELL
ESTABLISHED S/SWWD ACROSS THE TX BIG COUNTRY TO THE ERN EDWARDS
PLATEAU BY LATE AFTERNOON. SCATTERED TSTMS WILL INITIATE ALONG THESE
BOUNDARIES BY MID-AFTERNOON. MORNING CONVECTION-ALLOWING MODEL
GUIDANCE ARE INSISTENT THAT THIS ACTIVITY WILL RAPIDLY GROW UPSCALE
INTO NUMEROUS LINE SEGMENTS...SURGING EWD THIS EVENING WITHIN A
STRONGLY UNSTABLE ENVIRONMENT.

INITIAL TSTMS WILL BECOME SUPERCELLUAR QUICKLY WITH VERY LARGE HAIL
LIKELY AS HODOGRAPHS/INSTABILITY WILL BE QUITE FAVORABLE...ALONG
WITH A FEW TORNADOES. THE GREATEST RISK FOR A COUPLE OF STRONG
TORNADOES SHOULD EXIST FROM S-CNTRL INTO E-CNTRL OK. BUT WITH
PREDOMINANT SWLY COMPONENT TO LOW-LEVEL FLOW AND MODERATE 0-1 KM
SHEAR...OVERALL TORNADO INTENSITY/LONGEVITY MAY BE
TEMPERED...ESPECIALLY WITH CONVECTION EXPECTED TO GROW UPSCALE SO
QUICKLY. NEVERTHELESS...THIS GROWTH SHOULD YIELD BOWING LINEAR
SEGMENTS CAPABLE OF SWATHS OF WIDESPREAD DAMAGING WINDS...LARGE HAIL
AND A FEW TORNADOES.

...MID/UPPER-MS VALLEY TO CNTRL GREAT LAKES...
PRIMARY CHANGE HAS BEEN TO EXPAND DAMAGING WIND PROBABILITIES E/NEWD
FOR THIS AFTERNOON AND EVENING. IN THE WAKE OF CONVECTION
YESTERDAY...LOW-LEVEL MOISTURE PLUME HAS BECOME CONFINED FROM LOWER
MI S/SSWD TO THE CONFLUENCE OF THE MS/OH RIVERS. BUT PLENTIFUL
HEATING IS OCCURRING TO THE N OF THIS PLUME WILL YIELD A RECOVERING
AIR MASS DOWNSTREAM OF A TSTM CLUSTER APPROACHING CNTRL MO. THIS
ACTIVITY SHOULD GROW UPSCALE ALONG THE EDGE OF THE INSTABILITY
AXIS...WITH ADDITIONAL LINEAR SEGMENTS EMANATING E/NEWD FROM THE
OZARK PLATEAU LATER TODAY. SWATHS OF DAMAGING WINDS...LARGE HAIL AND
A COUPLE OF TORNADOES WILL BE POSSIBLE.

FARTHER N/NW...SCATTERED TSTMS ARE EXPECTED TO FORM OVER LOWER MI
AND IN PARTS OF THE UPPER MIDWEST IN ASSOCIATION WITH AN UPPER-LEVEL
LOW CENTERED OVER ERN SD. BUOYANCY WILL BE STRONGEST OVER LOWER MI
WITHIN THE LOW-LEVEL MOISTURE PLUME CHARACTERIZED BY MIDDLE TO UPPER
60S SURFACE DEW POINTS. IN THE UPPER MIDWEST...POCKETS OF ROBUST
SURFACE HEATING WILL SUPPORT AT LEAST MODEST INSTABILITY AND WITH
STRONG UNIDIRECTIONAL WIND PROFILES...SETUP COULD A FEW ORGANIZED
TSTM CLUSTERS. A MIX OF ISOLATED SEVERE HAIL/WIND SHOULD BE THE
PRIMARY THREATS.

000
ACUS11 KWNS 201931
SWOMCD
SPC MCD 201931
OKZ000-KSZ000-202130-

MESOSCALE DISCUSSION 0728
NWS STORM PREDICTION CENTER NORMAN OK
0231 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL INTO NERN OK AND SERN KS

CONCERNING...TORNADO WATCH 190...191...

VALID 201931Z - 202130Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 190...191...CONTINUES.

SUMMARY...THE THREAT FOR TORNADOES MAY BE INCREASING OVER THE NEXT
FEW HOURS...ESPECIALLY ACROSS NERN OK.

DISCUSSION...STORMS ARE GRADUALLY FORMING ALONG THE FRONT FROM NWRN
TX ACROSS OK AND INTO SERN KS. SPECIAL SOUNDINGS ACROSS THE
AREA...AS WELL AS PROFILER DATA INDICATE A VEER-BACK PATTERN BETWEEN
850 AND 700 MB ESPECIALLY FROM NRN TX INTO SRN OK. THIS WEAKNESS IN
THE HODOGRAPH MAY INHIBIT THE DEVELOPMENT OF ROBUST ROTATION UNTIL
LATER IN THE AFTERNOON.

HOWEVER...IN THE SHORT TERM...WIND PROFILES CURRENTLY APPEAR TO BE
MORE FAVORABLE FOR ROTATION FROM CNTRL/NERN OK INTO SERN KS...WITH
0-1 SRH OF 100-150 M2/S2. IN ADDITION...CLEARING HAS ALLOWED FOR A
ROBUST CU FIELD GENERALLY E OF I-35 AND N OF I-40...WHERE THICK
STRATUS PREVIOUSLY EXISTED. DEEP LAYER SHEAR AND EXTREME INSTABILITY
PROFILES WILL FAVOR RAPID INTENSIFICATION AND STORMS MAY CHANGE
CHARACTER QUICKLY AS THEY TRAVEL NEWD ACROSS A VERY MOIST WARM
SECTOR WITH LOCALLY BACKED SFC WINDS.

..JEWELL.. 05/20/2013

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

ATTN...WFO...SGF...TSA...ICT...OUN...

LAT...LON   36309535 35429621 35279718 35409773 35589777 36059737
            36699692 37239672 37909590 37989537 37839501 37409478
            36949491 36309535

000
ACUS11 KWNS 201931
SWOMCD
SPC MCD 201931
OKZ000-KSZ000-202130-

MESOSCALE DISCUSSION 0728
NWS STORM PREDICTION CENTER NORMAN OK
0231 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL INTO NERN OK AND SERN KS

CONCERNING...TORNADO WATCH 190...191...

VALID 201931Z - 202130Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 190...191...CONTINUES.

SUMMARY...THE THREAT FOR TORNADOES MAY BE INCREASING OVER THE NEXT
FEW HOURS...ESPECIALLY ACROSS NERN OK.

DISCUSSION...STORMS ARE GRADUALLY FORMING ALONG THE FRONT FROM NWRN
TX ACROSS OK AND INTO SERN KS. SPECIAL SOUNDINGS ACROSS THE
AREA...AS WELL AS PROFILER DATA INDICATE A VEER-BACK PATTERN BETWEEN
850 AND 700 MB ESPECIALLY FROM NRN TX INTO SRN OK. THIS WEAKNESS IN
THE HODOGRAPH MAY INHIBIT THE DEVELOPMENT OF ROBUST ROTATION UNTIL
LATER IN THE AFTERNOON.

HOWEVER...IN THE SHORT TERM...WIND PROFILES CURRENTLY APPEAR TO BE
MORE FAVORABLE FOR ROTATION FROM CNTRL/NERN OK INTO SERN KS...WITH
0-1 SRH OF 100-150 M2/S2. IN ADDITION...CLEARING HAS ALLOWED FOR A
ROBUST CU FIELD GENERALLY E OF I-35 AND N OF I-40...WHERE THICK
STRATUS PREVIOUSLY EXISTED. DEEP LAYER SHEAR AND EXTREME INSTABILITY
PROFILES WILL FAVOR RAPID INTENSIFICATION AND STORMS MAY CHANGE
CHARACTER QUICKLY AS THEY TRAVEL NEWD ACROSS A VERY MOIST WARM
SECTOR WITH LOCALLY BACKED SFC WINDS.

..JEWELL.. 05/20/2013

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

ATTN...WFO...SGF...TSA...ICT...OUN...

LAT...LON   36309535 35429621 35279718 35409773 35589777 36059737
            36699692 37239672 37909590 37989537 37839501 37409478
            36949491 36309535

000
ACUS11 KWNS 201931
SWOMCD
SPC MCD 201931
OKZ000-KSZ000-202130-

MESOSCALE DISCUSSION 0728
NWS STORM PREDICTION CENTER NORMAN OK
0231 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL INTO NERN OK AND SERN KS

CONCERNING...TORNADO WATCH 190...191...

VALID 201931Z - 202130Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 190...191...CONTINUES.

SUMMARY...THE THREAT FOR TORNADOES MAY BE INCREASING OVER THE NEXT
FEW HOURS...ESPECIALLY ACROSS NERN OK.

DISCUSSION...STORMS ARE GRADUALLY FORMING ALONG THE FRONT FROM NWRN
TX ACROSS OK AND INTO SERN KS. SPECIAL SOUNDINGS ACROSS THE
AREA...AS WELL AS PROFILER DATA INDICATE A VEER-BACK PATTERN BETWEEN
850 AND 700 MB ESPECIALLY FROM NRN TX INTO SRN OK. THIS WEAKNESS IN
THE HODOGRAPH MAY INHIBIT THE DEVELOPMENT OF ROBUST ROTATION UNTIL
LATER IN THE AFTERNOON.

HOWEVER...IN THE SHORT TERM...WIND PROFILES CURRENTLY APPEAR TO BE
MORE FAVORABLE FOR ROTATION FROM CNTRL/NERN OK INTO SERN KS...WITH
0-1 SRH OF 100-150 M2/S2. IN ADDITION...CLEARING HAS ALLOWED FOR A
ROBUST CU FIELD GENERALLY E OF I-35 AND N OF I-40...WHERE THICK
STRATUS PREVIOUSLY EXISTED. DEEP LAYER SHEAR AND EXTREME INSTABILITY
PROFILES WILL FAVOR RAPID INTENSIFICATION AND STORMS MAY CHANGE
CHARACTER QUICKLY AS THEY TRAVEL NEWD ACROSS A VERY MOIST WARM
SECTOR WITH LOCALLY BACKED SFC WINDS.

..JEWELL.. 05/20/2013

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

ATTN...WFO...SGF...TSA...ICT...OUN...

LAT...LON   36309535 35429621 35279718 35409773 35589777 36059737
            36699692 37239672 37909590 37989537 37839501 37409478
            36949491 36309535

000
ACUS11 KWNS 201820
SWOMCD
SPC MCD 201819
OKZ000-TXZ000-202015-

MESOSCALE DISCUSSION 0727
NWS STORM PREDICTION CENTER NORMAN OK
0119 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 201819Z - 202015Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A FEW SUPERCELLS ARE EXPECTED TO FORM ALONG THE DRYLINE
LATER THIS AFTERNOON...WITH VERY LARGE HAIL LIKELY. AN ISOLATED
TORNADO IS POSSIBLE. A WATCH IS LIKELY BEFORE 20Z.

DISCUSSION...STRONG HEATING PERSISTS ACROSS CNTRL/WRN TX WITH VERY
STRONG INSTABILITY IN PLACE E OF THE DRYLINE. VISIBLE IMAGERY SHOWS
TCU INCREASING OVER THROCKMORTON AND YOUNG COUNTIES...WITH
ADDITIONAL CU SW OF SEP. ALTHOUGH WELL S OF THE JET...DEEP LAYER
SHEAR VALUES AND OVERALL HODOGRAPH LENGTH WITH INCREASING UPPER
LEVEL WINDS WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS. AMPLE
MOISTURE AND COLD PROFILES ALOFT WILL RESULT IN VERY LARGE DAMAGING
HAIL.

THIS EVENING...CAPPING WILL INHIBIT EWD PROGRESSION OF THESE
CELLS...LIKELY DYING CLOSE TO I-35 BY 03Z.

..JEWELL/KERR.. 05/20/2013

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

ATTN...WFO...FWD...OUN...EWX...SJT...

LAT...LON   33819647 32709666 31659704 31139725 30769756 30639825
            30799907 31069961 31329984 31849966 32769922 33509866
            33829827 33919779 33969706 33819647

000
ACUS11 KWNS 201820
SWOMCD
SPC MCD 201819
OKZ000-TXZ000-202015-

MESOSCALE DISCUSSION 0727
NWS STORM PREDICTION CENTER NORMAN OK
0119 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 201819Z - 202015Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A FEW SUPERCELLS ARE EXPECTED TO FORM ALONG THE DRYLINE
LATER THIS AFTERNOON...WITH VERY LARGE HAIL LIKELY. AN ISOLATED
TORNADO IS POSSIBLE. A WATCH IS LIKELY BEFORE 20Z.

DISCUSSION...STRONG HEATING PERSISTS ACROSS CNTRL/WRN TX WITH VERY
STRONG INSTABILITY IN PLACE E OF THE DRYLINE. VISIBLE IMAGERY SHOWS
TCU INCREASING OVER THROCKMORTON AND YOUNG COUNTIES...WITH
ADDITIONAL CU SW OF SEP. ALTHOUGH WELL S OF THE JET...DEEP LAYER
SHEAR VALUES AND OVERALL HODOGRAPH LENGTH WITH INCREASING UPPER
LEVEL WINDS WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS. AMPLE
MOISTURE AND COLD PROFILES ALOFT WILL RESULT IN VERY LARGE DAMAGING
HAIL.

THIS EVENING...CAPPING WILL INHIBIT EWD PROGRESSION OF THESE
CELLS...LIKELY DYING CLOSE TO I-35 BY 03Z.

..JEWELL/KERR.. 05/20/2013

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

ATTN...WFO...FWD...OUN...EWX...SJT...

LAT...LON   33819647 32709666 31659704 31139725 30769756 30639825
            30799907 31069961 31329984 31849966 32769922 33509866
            33829827 33919779 33969706 33819647

000
ACUS11 KWNS 201820
SWOMCD
SPC MCD 201819
OKZ000-TXZ000-202015-

MESOSCALE DISCUSSION 0727
NWS STORM PREDICTION CENTER NORMAN OK
0119 PM CDT MON MAY 20 2013

AREAS AFFECTED...CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 201819Z - 202015Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A FEW SUPERCELLS ARE EXPECTED TO FORM ALONG THE DRYLINE
LATER THIS AFTERNOON...WITH VERY LARGE HAIL LIKELY. AN ISOLATED
TORNADO IS POSSIBLE. A WATCH IS LIKELY BEFORE 20Z.

DISCUSSION...STRONG HEATING PERSISTS ACROSS CNTRL/WRN TX WITH VERY
STRONG INSTABILITY IN PLACE E OF THE DRYLINE. VISIBLE IMAGERY SHOWS
TCU INCREASING OVER THROCKMORTON AND YOUNG COUNTIES...WITH
ADDITIONAL CU SW OF SEP. ALTHOUGH WELL S OF THE JET...DEEP LAYER
SHEAR VALUES AND OVERALL HODOGRAPH LENGTH WITH INCREASING UPPER
LEVEL WINDS WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS. AMPLE
MOISTURE AND COLD PROFILES ALOFT WILL RESULT IN VERY LARGE DAMAGING
HAIL.

THIS EVENING...CAPPING WILL INHIBIT EWD PROGRESSION OF THESE
CELLS...LIKELY DYING CLOSE TO I-35 BY 03Z.

..JEWELL/KERR.. 05/20/2013

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

ATTN...WFO...FWD...OUN...EWX...SJT...

LAT...LON   33819647 32709666 31659704 31139725 30769756 30639825
            30799907 31069961 31329984 31849966 32769922 33509866
            33829827 33919779 33969706 33819647

000
ACUS02 KWNS 201730
SWODY2
SPC AC 201728

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT MON MAY 20 2013

VALID 211200Z - 221200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER NERN TX...EXTREME SERN
OK...CENTRAL AND SRN AR...AND NWRN LA...

...THERE IS A SLGT RISK OF SVR TSTMS FROM TX INTO THE GREAT LAKES
REGION...

...SYNOPSIS...
UPPER FLOW PATTERN IS FORECAST TO CHANGE SLOWLY THROUGH TOMORROW AS
AN UPPER LOW OVER THE NRN PLAINS DRIFTS EWD AND WEAKENS GRADUALLY
WHILE AN UPSTREAM COLD LOW DROPS SEWD ALONG THE PACIFIC NW COAST.  A
SHORT WAVE TROUGH EVIDENT NOW OVER THE FOUR-CORNERS AREA IS EXPECTED
TO TRANSLATE EWD ACROSS THE SRN PLAINS DURING THE AFTERNOON BEFORE
LIFTING NEWD AND BECOMING ABSORBED INTO THE SERN PERIPHERY OF THE
NRN PLAINS UPPER LOW.  IN THE SOUTHEAST...A WEAK UPPER LOW IS
FORECAST TO DRIFT OVER THE FL PENINSULA.

AT THE SURFACE...A LOW OVER THE UPPER MIDWEST WILL EVOLVE SLOWLY EWD
AND WEAKEN GRADUALLY...WHILE A TRAILING COLD FRONT EXTENDING SWWD
FROM THE LOW ACROSS THE MIDDLE MS VALLEY SWWD INTO OK AND TX WILL
DRIFT SEWD.  CURRENT INDICATIONS ARE THAT PRE-FRONTAL CONVECTION
DURING THE DAY 1 OVERNIGHT HOURS WILL RESULT IN OUTFLOW BOUNDARIES
LOCATED WITHIN THE WARM SECTOR AT THE START OF THE PERIOD...AND
THESE ARE EXPECTED TO PROVIDE AN ADDITIONAL FOCUS FOR SUBSEQUENT
THUNDERSTORM REDEVELOPMENT DURING THE DIURNAL HEATING CYCLE ON
TUESDAY.

...AR/SERN OK/NERN AND CENTRAL TX...
MODEL CONSENSUS /INCLUDING CONVECTION-ALLOWING MODEL ENSEMBLES/
SUGGESTS THAT CONVECTION WILL BE OVER PARTS OF AR/OK AND NRN TX
EARLY IN THE PERIOD...WITH A COMPOSITE OUTFLOW BOUNDARY EXTENDING
FROM SERN AR INTO NERN/NORTH CENTRAL TX EARLY IN THE PERIOD.  SOUTH
OF THE BOUNDARY A WARM/MOIST AIR MASS WILL BE PRESENT WITH SURFACE
DEW POINTS IN THE UPPER 60S-LOWER 70S...AND WITH ENHANCED DIABATIC
HEATING ANTICIPATED INTO THE AFTERNOON COUPLED WITH PRE-EXISTING
MODERATE MID-LEVEL LAPSE RATES...MLCAPE OF 3000-3500 J/KG IS
EXPECTED BY THE AFTERNOON.  AS THE AFOREMENTIONED SHORT WAVE TROUGH
PROGRESSES EWD ACROSS THE SRN PLAINS DURING THE AFTERNOON...STORM
INITIATION IS EXPECTED FROM SERN OK/SWRN AR INTO PARTS OF NRN TX
NEAR THE EARLIER OUTFLOW BOUNDARY.  ADDITIONAL STORMS ARE LIKELY TO
DEVELOP SWWD NEAR/AHEAD OF THE WEAKENING FRONT INTO CENTRAL
TX...WITH ALL ACTIVITY SPREADING EWD/NEWD THROUGH THE EVENING HOURS.

ALTHOUGH LOW-LEVEL WINDS WILL GENERALLY BE AOB 20-25 KT...FORECAST
SOUNDINGS INDICATE WINDS WILL INCREASE AND VEER WITH HEIGHT IN
RESPONSE TO THE PROGRESSIVE SHORT WAVE TROUGH...PROVIDING SUFFICIENT
VERTICAL SHEAR FOR ORGANIZED CONVECTIVE STRUCTURES INCLUDING A FEW
SUPERCELLS TO DEVELOP.  VERY LARGE HAIL...DAMAGING WIND GUSTS...AND
POSSIBLY A FEW TORNADOES WILL BE POSSIBLE...ESPECIALLY WHERE
BOUNDARY INTERACTIONS MAY ENHANCE LOW LEVEL SHEAR/SRH.  ACTIVITY IS
EXPECTED TO GROW UPSCALE BY EVENING WITH SEVERAL QLCS/S FORMING
WHICH MAY RESULT IN AN INCREASE IN WIND DAMAGE POTENTIAL.  ACTIVITY
IS THEN EXPECTED TO WEAKEN GRADUALLY BY 03-6Z AS THE SHORT WAVE
TROUGH LIFTS NEWD AWAY FROM THE REGION AND DIURNAL COOLING BEGINS TO
STABILIZE THE BOUNDARY LAYER.

...MID MS VALLEY NEWD INTO THE GREAT LAKES REGION...
OVERNIGHT CONVECTION ACROSS MUCH OF THIS REGION WILL TEMPORARILY
STABILIZE THE LOCAL ENVIRONMENT AT THE BEGINNING OF THE PERIOD...AND
WILL RESULT IN A COMPLEX MESOSCALE SURFACE PATTERN WITHIN THE WARM
SECTOR. AS CONVECTION CONTINUES TO WEAKEN OVER THIS AREA DURING THE
MORNING...BREAKS IN CLOUDS WILL PERMIT REGIONS OF ENHANCED DIABATIC
HEATING AND DESTABILIZATION TO OCCUR AMIDST A WARM/MOIST LOW LEVEL
ENVIRONMENT.  ZONES OF ENHANCED LOW LEVEL CONVERGENCE ALONG REMNANT
OUTFLOW BOUNDARIES WILL PROVIDE A FOCUS FOR STORM REDEVELOPMENT BY
EARLY-MID AFTERNOON.  SWLY MID LEVEL WINDS OF 35-45 KT WILL PROVIDE
SUFFICIENT DEEP LAYER SHEAR FOR ORGANIZED STRONG/SEVERE STORMS TO
DEVELOP...WITH A THREAT FOR LARGE HAIL...DAMAGING WINDS...AND
POSSIBLY A FEW TORNADOES MAINLY THROUGH THE EVENING HOURS.

THERE IS ALSO POTENTIAL FOR SEPARATE BANDS OF STRONG/SEVERE
THUNDERSTORMS TO DEVELOP ALONG/AHEAD OF THE COLD FRONT ARCING ACROSS
WI DURING THE AFTERNOON AND EVENING.

...LOWER GREAT LAKES INTO NY/WRN MA...
GUIDANCE INDICATES STRONGER STORMS WILL BE POSSIBLE ALONG/NORTH OF A
WARM FRONT LIFTING SLOWLY NWD ACROSS THIS AREA.  ALTHOUGH LOW LEVEL
MOISTURE WILL BE INCREASING...WEAKER MID LEVEL LAPSE RATES WILL TEND
TO LIMIT THE OVERALL MAGNITUDE OF INSTABILITY WITH MLCAPE OF
1000-1500 J/KG EXPECTED.  THERE WILL BE POTENTIAL FOR ISOLATED
SEVERE STORMS DURING THE AFTERNOON AND EVENING...BUT WITH THE
STRONGER MID LEVEL WINDS EXPECTED TO BE DISPLACED NWD AWAY FROM THE
WARM FRONT...POTENTIAL FOR A MORE WIDESPREAD THREAT WILL BE LIMITED.
IF LARGER INSTABILITY THAN CURRENTLY EXPECTED DEVELOPS...AN UPGRADE
TO SLIGHT RISK MAY NEED TO BE CONSIDERED.

..WEISS.. 05/20/2013

000
ACUS02 KWNS 201730
SWODY2
SPC AC 201728

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT MON MAY 20 2013

VALID 211200Z - 221200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER NERN TX...EXTREME SERN
OK...CENTRAL AND SRN AR...AND NWRN LA...

...THERE IS A SLGT RISK OF SVR TSTMS FROM TX INTO THE GREAT LAKES
REGION...

...SYNOPSIS...
UPPER FLOW PATTERN IS FORECAST TO CHANGE SLOWLY THROUGH TOMORROW AS
AN UPPER LOW OVER THE NRN PLAINS DRIFTS EWD AND WEAKENS GRADUALLY
WHILE AN UPSTREAM COLD LOW DROPS SEWD ALONG THE PACIFIC NW COAST.  A
SHORT WAVE TROUGH EVIDENT NOW OVER THE FOUR-CORNERS AREA IS EXPECTED
TO TRANSLATE EWD ACROSS THE SRN PLAINS DURING THE AFTERNOON BEFORE
LIFTING NEWD AND BECOMING ABSORBED INTO THE SERN PERIPHERY OF THE
NRN PLAINS UPPER LOW.  IN THE SOUTHEAST...A WEAK UPPER LOW IS
FORECAST TO DRIFT OVER THE FL PENINSULA.

AT THE SURFACE...A LOW OVER THE UPPER MIDWEST WILL EVOLVE SLOWLY EWD
AND WEAKEN GRADUALLY...WHILE A TRAILING COLD FRONT EXTENDING SWWD
FROM THE LOW ACROSS THE MIDDLE MS VALLEY SWWD INTO OK AND TX WILL
DRIFT SEWD.  CURRENT INDICATIONS ARE THAT PRE-FRONTAL CONVECTION
DURING THE DAY 1 OVERNIGHT HOURS WILL RESULT IN OUTFLOW BOUNDARIES
LOCATED WITHIN THE WARM SECTOR AT THE START OF THE PERIOD...AND
THESE ARE EXPECTED TO PROVIDE AN ADDITIONAL FOCUS FOR SUBSEQUENT
THUNDERSTORM REDEVELOPMENT DURING THE DIURNAL HEATING CYCLE ON
TUESDAY.

...AR/SERN OK/NERN AND CENTRAL TX...
MODEL CONSENSUS /INCLUDING CONVECTION-ALLOWING MODEL ENSEMBLES/
SUGGESTS THAT CONVECTION WILL BE OVER PARTS OF AR/OK AND NRN TX
EARLY IN THE PERIOD...WITH A COMPOSITE OUTFLOW BOUNDARY EXTENDING
FROM SERN AR INTO NERN/NORTH CENTRAL TX EARLY IN THE PERIOD.  SOUTH
OF THE BOUNDARY A WARM/MOIST AIR MASS WILL BE PRESENT WITH SURFACE
DEW POINTS IN THE UPPER 60S-LOWER 70S...AND WITH ENHANCED DIABATIC
HEATING ANTICIPATED INTO THE AFTERNOON COUPLED WITH PRE-EXISTING
MODERATE MID-LEVEL LAPSE RATES...MLCAPE OF 3000-3500 J/KG IS
EXPECTED BY THE AFTERNOON.  AS THE AFOREMENTIONED SHORT WAVE TROUGH
PROGRESSES EWD ACROSS THE SRN PLAINS DURING THE AFTERNOON...STORM
INITIATION IS EXPECTED FROM SERN OK/SWRN AR INTO PARTS OF NRN TX
NEAR THE EARLIER OUTFLOW BOUNDARY.  ADDITIONAL STORMS ARE LIKELY TO
DEVELOP SWWD NEAR/AHEAD OF THE WEAKENING FRONT INTO CENTRAL
TX...WITH ALL ACTIVITY SPREADING EWD/NEWD THROUGH THE EVENING HOURS.

ALTHOUGH LOW-LEVEL WINDS WILL GENERALLY BE AOB 20-25 KT...FORECAST
SOUNDINGS INDICATE WINDS WILL INCREASE AND VEER WITH HEIGHT IN
RESPONSE TO THE PROGRESSIVE SHORT WAVE TROUGH...PROVIDING SUFFICIENT
VERTICAL SHEAR FOR ORGANIZED CONVECTIVE STRUCTURES INCLUDING A FEW
SUPERCELLS TO DEVELOP.  VERY LARGE HAIL...DAMAGING WIND GUSTS...AND
POSSIBLY A FEW TORNADOES WILL BE POSSIBLE...ESPECIALLY WHERE
BOUNDARY INTERACTIONS MAY ENHANCE LOW LEVEL SHEAR/SRH.  ACTIVITY IS
EXPECTED TO GROW UPSCALE BY EVENING WITH SEVERAL QLCS/S FORMING
WHICH MAY RESULT IN AN INCREASE IN WIND DAMAGE POTENTIAL.  ACTIVITY
IS THEN EXPECTED TO WEAKEN GRADUALLY BY 03-6Z AS THE SHORT WAVE
TROUGH LIFTS NEWD AWAY FROM THE REGION AND DIURNAL COOLING BEGINS TO
STABILIZE THE BOUNDARY LAYER.

...MID MS VALLEY NEWD INTO THE GREAT LAKES REGION...
OVERNIGHT CONVECTION ACROSS MUCH OF THIS REGION WILL TEMPORARILY
STABILIZE THE LOCAL ENVIRONMENT AT THE BEGINNING OF THE PERIOD...AND
WILL RESULT IN A COMPLEX MESOSCALE SURFACE PATTERN WITHIN THE WARM
SECTOR. AS CONVECTION CONTINUES TO WEAKEN OVER THIS AREA DURING THE
MORNING...BREAKS IN CLOUDS WILL PERMIT REGIONS OF ENHANCED DIABATIC
HEATING AND DESTABILIZATION TO OCCUR AMIDST A WARM/MOIST LOW LEVEL
ENVIRONMENT.  ZONES OF ENHANCED LOW LEVEL CONVERGENCE ALONG REMNANT
OUTFLOW BOUNDARIES WILL PROVIDE A FOCUS FOR STORM REDEVELOPMENT BY
EARLY-MID AFTERNOON.  SWLY MID LEVEL WINDS OF 35-45 KT WILL PROVIDE
SUFFICIENT DEEP LAYER SHEAR FOR ORGANIZED STRONG/SEVERE STORMS TO
DEVELOP...WITH A THREAT FOR LARGE HAIL...DAMAGING WINDS...AND
POSSIBLY A FEW TORNADOES MAINLY THROUGH THE EVENING HOURS.

THERE IS ALSO POTENTIAL FOR SEPARATE BANDS OF STRONG/SEVERE
THUNDERSTORMS TO DEVELOP ALONG/AHEAD OF THE COLD FRONT ARCING ACROSS
WI DURING THE AFTERNOON AND EVENING.

...LOWER GREAT LAKES INTO NY/WRN MA...
GUIDANCE INDICATES STRONGER STORMS WILL BE POSSIBLE ALONG/NORTH OF A
WARM FRONT LIFTING SLOWLY NWD ACROSS THIS AREA.  ALTHOUGH LOW LEVEL
MOISTURE WILL BE INCREASING...WEAKER MID LEVEL LAPSE RATES WILL TEND
TO LIMIT THE OVERALL MAGNITUDE OF INSTABILITY WITH MLCAPE OF
1000-1500 J/KG EXPECTED.  THERE WILL BE POTENTIAL FOR ISOLATED
SEVERE STORMS DURING THE AFTERNOON AND EVENING...BUT WITH THE
STRONGER MID LEVEL WINDS EXPECTED TO BE DISPLACED NWD AWAY FROM THE
WARM FRONT...POTENTIAL FOR A MORE WIDESPREAD THREAT WILL BE LIMITED.
IF LARGER INSTABILITY THAN CURRENTLY EXPECTED DEVELOPS...AN UPGRADE
TO SLIGHT RISK MAY NEED TO BE CONSIDERED.

..WEISS.. 05/20/2013

000
ACUS11 KWNS 201727
SWOMCD
SPC MCD 201726
MOZ000-ARZ000-OKZ000-KSZ000-TXZ000-201930-

MESOSCALE DISCUSSION 0726
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT MON MAY 20 2013

AREAS AFFECTED...MUCH OF OK INTO NWRN TX AND SERN KS

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 201726Z - 201930Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SEVERE STORMS ARE LIKELY TO FORM THIS AFTERNOON WITH A FEW
SIGNIFICANT TORNADOES...EXTREMELY LARGE HAIL...AND DAMAGING WINDS
ALL POSSIBLE. TWO WATCHES WILL BE NEEDED SOON FROM KS INTO N TX.

DISCUSSION...SURFACE MAP SHOWS A QUASI-STATIONARY BOUNDARY FROM SERN
KS INTO NRN OK AND BENDING SWWD W OF THE I-44 CORRIDOR. FARTHER
SW...A WEAK AREA OF LOW PRESSURE WAS NOTED OVER NWRN TX...ON THE
NOSE OF A LOW LEVEL LAPSE RATE PLUME WITH DRYLINE EXTENDING SW
ACROSS W TX.

VISIBLE IMAGERY SHOWS DEEPENING CU ALONG THE BOUNDARY FROM NRN OK
INTO SERN KS WHERE A DEEP MOIST LAYER EXISTS. GIVEN A GRADUAL
INCREASE IN THETA-E AND BREAKS IN THE CLOUDS...THIS AREA COULD BE
WHERE INITIAL DEVELOPMENT OCCURS. LONG HODOGRAPHS AND STEEP MIDLEVEL
LAPSE RATES WILL FAVOR VERY LARGE HAIL...AND LOW LEVEL VEERING WIND
PROFILES WILL BE SUFFICIENT FOR TORNADOES GIVEN AFOREMENTIONED
THERMODYNAMIC FACTORS.

TO THE S...AN EXTREMELY VOLATILE AIR MASS EXISTS WITH AN INCREASING
CU FIELD FROM NWRN TX INTO SWRN OK WHERE STRONG HEATING PERSISTS.
WIND FIELDS ALOFT ARE MORE THAN FAVORABLE FOR SUPERCELLS...WITH VERY
LARGE HAIL LIKELY. ALTHOUGH SHEAR IN THE LOWEST 1-2 KM IS NOT
PARTICULARLY STRONG...VERY LARGE VERTICAL ACCELERATIONS...AS WELL AS
HODOGRAPH AUGMENTATION NEAR THE SFC FRONT WILL AID IN TORNADO
POTENTIAL. HP SUPERCELLS ARE EXPECTED WITH STRONG MESOCYCLONES AND
POSSIBLE RAIN-WRAPPED TORNADOES.

ACTIVITY MAY EVENTUALLY MERGE INTO ONE OR MORE BOWS...AND RAPIDLY
EXPAND NEWD ACROSS ERN OK LATER THIS EVENING PER MULTIPLE CONVECTION
ALLOWING MODELS.

..JEWELL/KERR.. 05/20/2013

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

ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT...FWD...OUN...
SJT...

LAT...LON   38009568 38799359 38829292 38659248 38349229 37719234
            35899422 35449480 34559586 34049620 33559661 33369740
            33269840 33309891 33409912 33629915 33849905 34419848
            34689843 35099837 35689820 37169692 38009568

000
ACUS11 KWNS 201727
SWOMCD
SPC MCD 201726
MOZ000-ARZ000-OKZ000-KSZ000-TXZ000-201930-

MESOSCALE DISCUSSION 0726
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT MON MAY 20 2013

AREAS AFFECTED...MUCH OF OK INTO NWRN TX AND SERN KS

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 201726Z - 201930Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SEVERE STORMS ARE LIKELY TO FORM THIS AFTERNOON WITH A FEW
SIGNIFICANT TORNADOES...EXTREMELY LARGE HAIL...AND DAMAGING WINDS
ALL POSSIBLE. TWO WATCHES WILL BE NEEDED SOON FROM KS INTO N TX.

DISCUSSION...SURFACE MAP SHOWS A QUASI-STATIONARY BOUNDARY FROM SERN
KS INTO NRN OK AND BENDING SWWD W OF THE I-44 CORRIDOR. FARTHER
SW...A WEAK AREA OF LOW PRESSURE WAS NOTED OVER NWRN TX...ON THE
NOSE OF A LOW LEVEL LAPSE RATE PLUME WITH DRYLINE EXTENDING SW
ACROSS W TX.

VISIBLE IMAGERY SHOWS DEEPENING CU ALONG THE BOUNDARY FROM NRN OK
INTO SERN KS WHERE A DEEP MOIST LAYER EXISTS. GIVEN A GRADUAL
INCREASE IN THETA-E AND BREAKS IN THE CLOUDS...THIS AREA COULD BE
WHERE INITIAL DEVELOPMENT OCCURS. LONG HODOGRAPHS AND STEEP MIDLEVEL
LAPSE RATES WILL FAVOR VERY LARGE HAIL...AND LOW LEVEL VEERING WIND
PROFILES WILL BE SUFFICIENT FOR TORNADOES GIVEN AFOREMENTIONED
THERMODYNAMIC FACTORS.

TO THE S...AN EXTREMELY VOLATILE AIR MASS EXISTS WITH AN INCREASING
CU FIELD FROM NWRN TX INTO SWRN OK WHERE STRONG HEATING PERSISTS.
WIND FIELDS ALOFT ARE MORE THAN FAVORABLE FOR SUPERCELLS...WITH VERY
LARGE HAIL LIKELY. ALTHOUGH SHEAR IN THE LOWEST 1-2 KM IS NOT
PARTICULARLY STRONG...VERY LARGE VERTICAL ACCELERATIONS...AS WELL AS
HODOGRAPH AUGMENTATION NEAR THE SFC FRONT WILL AID IN TORNADO
POTENTIAL. HP SUPERCELLS ARE EXPECTED WITH STRONG MESOCYCLONES AND
POSSIBLE RAIN-WRAPPED TORNADOES.

ACTIVITY MAY EVENTUALLY MERGE INTO ONE OR MORE BOWS...AND RAPIDLY
EXPAND NEWD ACROSS ERN OK LATER THIS EVENING PER MULTIPLE CONVECTION
ALLOWING MODELS.

..JEWELL/KERR.. 05/20/2013

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

ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT...FWD...OUN...
SJT...

LAT...LON   38009568 38799359 38829292 38659248 38349229 37719234
            35899422 35449480 34559586 34049620 33559661 33369740
            33269840 33309891 33409912 33629915 33849905 34419848
            34689843 35099837 35689820 37169692 38009568

000
ACUS11 KWNS 201727
SWOMCD
SPC MCD 201726
MOZ000-ARZ000-OKZ000-KSZ000-TXZ000-201930-

MESOSCALE DISCUSSION 0726
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT MON MAY 20 2013

AREAS AFFECTED...MUCH OF OK INTO NWRN TX AND SERN KS

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 201726Z - 201930Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SEVERE STORMS ARE LIKELY TO FORM THIS AFTERNOON WITH A FEW
SIGNIFICANT TORNADOES...EXTREMELY LARGE HAIL...AND DAMAGING WINDS
ALL POSSIBLE. TWO WATCHES WILL BE NEEDED SOON FROM KS INTO N TX.

DISCUSSION...SURFACE MAP SHOWS A QUASI-STATIONARY BOUNDARY FROM SERN
KS INTO NRN OK AND BENDING SWWD W OF THE I-44 CORRIDOR. FARTHER
SW...A WEAK AREA OF LOW PRESSURE WAS NOTED OVER NWRN TX...ON THE
NOSE OF A LOW LEVEL LAPSE RATE PLUME WITH DRYLINE EXTENDING SW
ACROSS W TX.

VISIBLE IMAGERY SHOWS DEEPENING CU ALONG THE BOUNDARY FROM NRN OK
INTO SERN KS WHERE A DEEP MOIST LAYER EXISTS. GIVEN A GRADUAL
INCREASE IN THETA-E AND BREAKS IN THE CLOUDS...THIS AREA COULD BE
WHERE INITIAL DEVELOPMENT OCCURS. LONG HODOGRAPHS AND STEEP MIDLEVEL
LAPSE RATES WILL FAVOR VERY LARGE HAIL...AND LOW LEVEL VEERING WIND
PROFILES WILL BE SUFFICIENT FOR TORNADOES GIVEN AFOREMENTIONED
THERMODYNAMIC FACTORS.

TO THE S...AN EXTREMELY VOLATILE AIR MASS EXISTS WITH AN INCREASING
CU FIELD FROM NWRN TX INTO SWRN OK WHERE STRONG HEATING PERSISTS.
WIND FIELDS ALOFT ARE MORE THAN FAVORABLE FOR SUPERCELLS...WITH VERY
LARGE HAIL LIKELY. ALTHOUGH SHEAR IN THE LOWEST 1-2 KM IS NOT
PARTICULARLY STRONG...VERY LARGE VERTICAL ACCELERATIONS...AS WELL AS
HODOGRAPH AUGMENTATION NEAR THE SFC FRONT WILL AID IN TORNADO
POTENTIAL. HP SUPERCELLS ARE EXPECTED WITH STRONG MESOCYCLONES AND
POSSIBLE RAIN-WRAPPED TORNADOES.

ACTIVITY MAY EVENTUALLY MERGE INTO ONE OR MORE BOWS...AND RAPIDLY
EXPAND NEWD ACROSS ERN OK LATER THIS EVENING PER MULTIPLE CONVECTION
ALLOWING MODELS.

..JEWELL/KERR.. 05/20/2013

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

ATTN...WFO...LSX...SGF...EAX...TSA...TOP...ICT...FWD...OUN...
SJT...

LAT...LON   38009568 38799359 38829292 38659248 38349229 37719234
            35899422 35449480 34559586 34049620 33559661 33369740
            33269840 33309891 33409912 33629915 33849905 34419848
            34689843 35099837 35689820 37169692 38009568

000
ACUS11 KWNS 201634
SWOMCD
SPC MCD 201634
MIZ000-INZ000-201730-

MESOSCALE DISCUSSION 0725
NWS STORM PREDICTION CENTER NORMAN OK
1134 AM CDT MON MAY 20 2013

AREAS AFFECTED...LOWER MI

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 201634Z - 201730Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...COVERAGE OF TSTMS SHOULD INCREASE THROUGH THE EARLY
AFTERNOON ACROSS WRN LOWER MI...AND MAY EVENTUALLY CONSOLIDATE AND
SPREAD EWD OVER THE REMAINDER OF LOWER MI LATER THIS AFTERNOON. AN
INITIAL THREAT OF DMGG WIND GUSTS...LARGE HAIL...AND PERHAPS A
BRIEF/WEAK TORNADO WILL EXIST AS ACTIVITY REMAINS
SEMI-DISCRETE...BUT SHOULD EVOLVE INTO PRIMARILY A DMGG WIND THREAT
WITH TIME. A WW WILL LIKELY BE NEEDED WITHIN THE NEXT HOUR.

DISCUSSION...STRONG HEATING IS OCCURRING ACROSS LOWER MI WITHIN A
MOIST BOUNDARY LAYER...CHARACTERIZED BY SFC DEW POINTS IN THE UPPER
60S F...CONTRIBUTING TO ESTIMATED MLCAPE VALUES OF 1500-2500 J/KG. A
RIBBON OF MIDLEVEL MOISTURE PRECEDING A LARGE NRN PLAINS TROUGH WAS
NOTED ON WATER VAPOR MOVING EWD ACROSS LAKE MI. AS THIS INTERSECTS
WEAK LOW-LEVEL CONVERGENCE ALONG A DEVELOPING SFC TROUGH NEAR THE
ERN SHORE OF LAKE MI...TSTMS SHOULD RAPIDLY DEVELOP. MODERATELY
STRONG BUT UNIDIRECTIONAL VERTICAL WIND PROFILES ORIENTED NEARLY
PARALLEL TO INITIATING LINE SHOULD PROMOTE MULTIPLE CELL
INTERACTIONS INITIALLY...BEFORE CONSOLIDATION INTO CLUSTERS OR A
QLCS OCCURS. THIS SHOULD PROPAGATE EWD ACROSS LOWER MI...POSING A
PRIMARY THREAT OF DMGG WINDS...ALTHOUGH SOME HAIL THREAT WILL ALSO
EXIST GIVEN THE DEGREE OF INSTABILITY PRESENT.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42648280 42158325 41898399 41758500 42018579 42928620
            43848603 44748600 45378534 45668491 45698433 45308361
            43938284 42648280

000
ACUS11 KWNS 201634
SWOMCD
SPC MCD 201634
MIZ000-INZ000-201730-

MESOSCALE DISCUSSION 0725
NWS STORM PREDICTION CENTER NORMAN OK
1134 AM CDT MON MAY 20 2013

AREAS AFFECTED...LOWER MI

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 201634Z - 201730Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...COVERAGE OF TSTMS SHOULD INCREASE THROUGH THE EARLY
AFTERNOON ACROSS WRN LOWER MI...AND MAY EVENTUALLY CONSOLIDATE AND
SPREAD EWD OVER THE REMAINDER OF LOWER MI LATER THIS AFTERNOON. AN
INITIAL THREAT OF DMGG WIND GUSTS...LARGE HAIL...AND PERHAPS A
BRIEF/WEAK TORNADO WILL EXIST AS ACTIVITY REMAINS
SEMI-DISCRETE...BUT SHOULD EVOLVE INTO PRIMARILY A DMGG WIND THREAT
WITH TIME. A WW WILL LIKELY BE NEEDED WITHIN THE NEXT HOUR.

DISCUSSION...STRONG HEATING IS OCCURRING ACROSS LOWER MI WITHIN A
MOIST BOUNDARY LAYER...CHARACTERIZED BY SFC DEW POINTS IN THE UPPER
60S F...CONTRIBUTING TO ESTIMATED MLCAPE VALUES OF 1500-2500 J/KG. A
RIBBON OF MIDLEVEL MOISTURE PRECEDING A LARGE NRN PLAINS TROUGH WAS
NOTED ON WATER VAPOR MOVING EWD ACROSS LAKE MI. AS THIS INTERSECTS
WEAK LOW-LEVEL CONVERGENCE ALONG A DEVELOPING SFC TROUGH NEAR THE
ERN SHORE OF LAKE MI...TSTMS SHOULD RAPIDLY DEVELOP. MODERATELY
STRONG BUT UNIDIRECTIONAL VERTICAL WIND PROFILES ORIENTED NEARLY
PARALLEL TO INITIATING LINE SHOULD PROMOTE MULTIPLE CELL
INTERACTIONS INITIALLY...BEFORE CONSOLIDATION INTO CLUSTERS OR A
QLCS OCCURS. THIS SHOULD PROPAGATE EWD ACROSS LOWER MI...POSING A
PRIMARY THREAT OF DMGG WINDS...ALTHOUGH SOME HAIL THREAT WILL ALSO
EXIST GIVEN THE DEGREE OF INSTABILITY PRESENT.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42648280 42158325 41898399 41758500 42018579 42928620
            43848603 44748600 45378534 45668491 45698433 45308361
            43938284 42648280

000
ACUS11 KWNS 201634
SWOMCD
SPC MCD 201634
MIZ000-INZ000-201730-

MESOSCALE DISCUSSION 0725
NWS STORM PREDICTION CENTER NORMAN OK
1134 AM CDT MON MAY 20 2013

AREAS AFFECTED...LOWER MI

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 201634Z - 201730Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...COVERAGE OF TSTMS SHOULD INCREASE THROUGH THE EARLY
AFTERNOON ACROSS WRN LOWER MI...AND MAY EVENTUALLY CONSOLIDATE AND
SPREAD EWD OVER THE REMAINDER OF LOWER MI LATER THIS AFTERNOON. AN
INITIAL THREAT OF DMGG WIND GUSTS...LARGE HAIL...AND PERHAPS A
BRIEF/WEAK TORNADO WILL EXIST AS ACTIVITY REMAINS
SEMI-DISCRETE...BUT SHOULD EVOLVE INTO PRIMARILY A DMGG WIND THREAT
WITH TIME. A WW WILL LIKELY BE NEEDED WITHIN THE NEXT HOUR.

DISCUSSION...STRONG HEATING IS OCCURRING ACROSS LOWER MI WITHIN A
MOIST BOUNDARY LAYER...CHARACTERIZED BY SFC DEW POINTS IN THE UPPER
60S F...CONTRIBUTING TO ESTIMATED MLCAPE VALUES OF 1500-2500 J/KG. A
RIBBON OF MIDLEVEL MOISTURE PRECEDING A LARGE NRN PLAINS TROUGH WAS
NOTED ON WATER VAPOR MOVING EWD ACROSS LAKE MI. AS THIS INTERSECTS
WEAK LOW-LEVEL CONVERGENCE ALONG A DEVELOPING SFC TROUGH NEAR THE
ERN SHORE OF LAKE MI...TSTMS SHOULD RAPIDLY DEVELOP. MODERATELY
STRONG BUT UNIDIRECTIONAL VERTICAL WIND PROFILES ORIENTED NEARLY
PARALLEL TO INITIATING LINE SHOULD PROMOTE MULTIPLE CELL
INTERACTIONS INITIALLY...BEFORE CONSOLIDATION INTO CLUSTERS OR A
QLCS OCCURS. THIS SHOULD PROPAGATE EWD ACROSS LOWER MI...POSING A
PRIMARY THREAT OF DMGG WINDS...ALTHOUGH SOME HAIL THREAT WILL ALSO
EXIST GIVEN THE DEGREE OF INSTABILITY PRESENT.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...DTX...APX...IWX...GRR...

LAT...LON   42648280 42158325 41898399 41758500 42018579 42928620
            43848603 44748600 45378534 45668491 45698433 45308361
            43938284 42648280

000
ACUS01 KWNS 201632
SWODY1
SPC AC 201630

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT MON MAY 20 2013

VALID 201630Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS FOR ERN/CNTRL OK...N-CNTRL
TX...NWRN AR...SRN MO...FAR SERN KS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY/CNTRL
GREAT LAKES TO THE SRN PLAINS...

...SRN PLAINS TO OZARK PLATEAU...
OVERALL FORECAST SCENARIO REMAINS SIMILAR TO EARLIER OUTLOOKS WITH
ONLY MINOR OVERALL CHANGES TO INDIVIDUAL HAZARD PROBABILITIES.
MID-LEVEL SPEED MAX /65 KT AT 500 MB IN THE 12Z ABQ RAOB/ ATTENDANT
TO THE SHORTWAVE IMPULSE OVER THE LEE OF THE SRN ROCKIES WILL
OVERSPREAD MOST OF OK TO THE LOWER MO VALLEY BY EARLY EVENING.
TRAILING PORTION OF COLD FRONT HAS BECOME SLOW-MOVING FROM SERN KS
TO SWRN OK...INTERSECTING A DRYLINE THAT WILL BECOME WELL
ESTABLISHED S/SWWD ACROSS THE TX BIG COUNTRY TO THE ERN EDWARDS
PLATEAU BY LATE AFTERNOON. SCATTERED TSTMS WILL INITIATE ALONG THESE
BOUNDARIES BY MID-AFTERNOON. MORNING CONVECTION-ALLOWING MODEL
GUIDANCE ARE INSISTENT THAT THIS ACTIVITY WILL RAPIDLY GROW UPSCALE
INTO NUMEROUS LINE SEGMENTS...SURGING EWD THIS EVENING WITHIN A
STRONGLY UNSTABLE ENVIRONMENT.

INITIAL TSTMS WILL BECOME SUPERCELLUAR QUICKLY WITH VERY LARGE HAIL
LIKELY AS HODOGRAPHS/INSTABILITY WILL BE QUITE FAVORABLE...ALONG
WITH A FEW TORNADOES. THE GREATEST RISK FOR A COUPLE OF STRONG
TORNADOES SHOULD EXIST FROM S-CNTRL INTO E-CNTRL OK. BUT WITH
PREDOMINANT SWLY COMPONENT TO LOW-LEVEL FLOW AND MODERATE 0-1 KM
SHEAR...OVERALL TORNADO INTENSITY/LONGEVITY MAY BE
TEMPERED...ESPECIALLY WITH CONVECTION EXPECTED TO GROW UPSCALE SO
QUICKLY. NEVERTHELESS...THIS GROWTH SHOULD YIELD BOWING LINEAR
SEGMENTS CAPABLE OF SWATHS OF WIDESPREAD DAMAGING WINDS...LARGE HAIL
AND A FEW TORNADOES.

...MID/UPPER-MS VALLEY TO CNTRL GREAT LAKES...
PRIMARY CHANGE HAS BEEN TO EXPAND DAMAGING WIND PROBABILITIES E/NEWD
FOR THIS AFTERNOON AND EVENING. IN THE WAKE OF CONVECTION
YESTERDAY...LOW-LEVEL MOISTURE PLUME HAS BECOME CONFINED FROM LOWER
MI S/SSWD TO THE CONFLUENCE OF THE MS/OH RIVERS. BUT PLENTIFUL
HEATING IS OCCURRING TO THE N OF THIS PLUME WILL YIELD A RECOVERING
AIR MASS DOWNSTREAM OF A TSTM CLUSTER APPROACHING CNTRL MO. THIS
ACTIVITY SHOULD GROW UPSCALE ALONG THE EDGE OF THE INSTABILITY
AXIS...WITH ADDITIONAL LINEAR SEGMENTS EMANATING E/NEWD FROM THE
OZARK PLATEAU LATER TODAY. SWATHS OF DAMAGING WINDS...LARGE HAIL AND
A COUPLE OF TORNADOES WILL BE POSSIBLE.

FARTHER N/NW...SCATTERED TSTMS ARE EXPECTED TO FORM OVER LOWER MI
AND IN PARTS OF THE UPPER MIDWEST IN ASSOCIATION WITH AN UPPER-LEVEL
LOW CENTERED OVER ERN SD. BUOYANCY WILL BE STRONGEST OVER LOWER MI
WITHIN THE LOW-LEVEL MOISTURE PLUME CHARACTERIZED BY MIDDLE TO UPPER
60S SURFACE DEW POINTS. IN THE UPPER MIDWEST...POCKETS OF ROBUST
SURFACE HEATING WILL SUPPORT AT LEAST MODEST INSTABILITY AND WITH
STRONG UNIDIRECTIONAL WIND PROFILES...SETUP COULD A FEW ORGANIZED
TSTM CLUSTERS. A MIX OF ISOLATED SEVERE HAIL/WIND SHOULD BE THE
PRIMARY THREATS.

..GRAMS/ROGERS.. 05/20/2013

000
ACUS01 KWNS 201632
SWODY1
SPC AC 201630

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT MON MAY 20 2013

VALID 201630Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS FOR ERN/CNTRL OK...N-CNTRL
TX...NWRN AR...SRN MO...FAR SERN KS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY/CNTRL
GREAT LAKES TO THE SRN PLAINS...

...SRN PLAINS TO OZARK PLATEAU...
OVERALL FORECAST SCENARIO REMAINS SIMILAR TO EARLIER OUTLOOKS WITH
ONLY MINOR OVERALL CHANGES TO INDIVIDUAL HAZARD PROBABILITIES.
MID-LEVEL SPEED MAX /65 KT AT 500 MB IN THE 12Z ABQ RAOB/ ATTENDANT
TO THE SHORTWAVE IMPULSE OVER THE LEE OF THE SRN ROCKIES WILL
OVERSPREAD MOST OF OK TO THE LOWER MO VALLEY BY EARLY EVENING.
TRAILING PORTION OF COLD FRONT HAS BECOME SLOW-MOVING FROM SERN KS
TO SWRN OK...INTERSECTING A DRYLINE THAT WILL BECOME WELL
ESTABLISHED S/SWWD ACROSS THE TX BIG COUNTRY TO THE ERN EDWARDS
PLATEAU BY LATE AFTERNOON. SCATTERED TSTMS WILL INITIATE ALONG THESE
BOUNDARIES BY MID-AFTERNOON. MORNING CONVECTION-ALLOWING MODEL
GUIDANCE ARE INSISTENT THAT THIS ACTIVITY WILL RAPIDLY GROW UPSCALE
INTO NUMEROUS LINE SEGMENTS...SURGING EWD THIS EVENING WITHIN A
STRONGLY UNSTABLE ENVIRONMENT.

INITIAL TSTMS WILL BECOME SUPERCELLUAR QUICKLY WITH VERY LARGE HAIL
LIKELY AS HODOGRAPHS/INSTABILITY WILL BE QUITE FAVORABLE...ALONG
WITH A FEW TORNADOES. THE GREATEST RISK FOR A COUPLE OF STRONG
TORNADOES SHOULD EXIST FROM S-CNTRL INTO E-CNTRL OK. BUT WITH
PREDOMINANT SWLY COMPONENT TO LOW-LEVEL FLOW AND MODERATE 0-1 KM
SHEAR...OVERALL TORNADO INTENSITY/LONGEVITY MAY BE
TEMPERED...ESPECIALLY WITH CONVECTION EXPECTED TO GROW UPSCALE SO
QUICKLY. NEVERTHELESS...THIS GROWTH SHOULD YIELD BOWING LINEAR
SEGMENTS CAPABLE OF SWATHS OF WIDESPREAD DAMAGING WINDS...LARGE HAIL
AND A FEW TORNADOES.

...MID/UPPER-MS VALLEY TO CNTRL GREAT LAKES...
PRIMARY CHANGE HAS BEEN TO EXPAND DAMAGING WIND PROBABILITIES E/NEWD
FOR THIS AFTERNOON AND EVENING. IN THE WAKE OF CONVECTION
YESTERDAY...LOW-LEVEL MOISTURE PLUME HAS BECOME CONFINED FROM LOWER
MI S/SSWD TO THE CONFLUENCE OF THE MS/OH RIVERS. BUT PLENTIFUL
HEATING IS OCCURRING TO THE N OF THIS PLUME WILL YIELD A RECOVERING
AIR MASS DOWNSTREAM OF A TSTM CLUSTER APPROACHING CNTRL MO. THIS
ACTIVITY SHOULD GROW UPSCALE ALONG THE EDGE OF THE INSTABILITY
AXIS...WITH ADDITIONAL LINEAR SEGMENTS EMANATING E/NEWD FROM THE
OZARK PLATEAU LATER TODAY. SWATHS OF DAMAGING WINDS...LARGE HAIL AND
A COUPLE OF TORNADOES WILL BE POSSIBLE.

FARTHER N/NW...SCATTERED TSTMS ARE EXPECTED TO FORM OVER LOWER MI
AND IN PARTS OF THE UPPER MIDWEST IN ASSOCIATION WITH AN UPPER-LEVEL
LOW CENTERED OVER ERN SD. BUOYANCY WILL BE STRONGEST OVER LOWER MI
WITHIN THE LOW-LEVEL MOISTURE PLUME CHARACTERIZED BY MIDDLE TO UPPER
60S SURFACE DEW POINTS. IN THE UPPER MIDWEST...POCKETS OF ROBUST
SURFACE HEATING WILL SUPPORT AT LEAST MODEST INSTABILITY AND WITH
STRONG UNIDIRECTIONAL WIND PROFILES...SETUP COULD A FEW ORGANIZED
TSTM CLUSTERS. A MIX OF ISOLATED SEVERE HAIL/WIND SHOULD BE THE
PRIMARY THREATS.

..GRAMS/ROGERS.. 05/20/2013

000
ACUS11 KWNS 201346
SWOMCD
SPC MCD 201346
MOZ000-KSZ000-201445-

MESOSCALE DISCUSSION 0724
NWS STORM PREDICTION CENTER NORMAN OK
0846 AM CDT MON MAY 20 2013

AREAS AFFECTED...SERN KS...W-CNTRL MO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 201346Z - 201445Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A NARROW CORRIDOR OF TSTMS HAS FORMED WITHIN THE PAST HR
ACROSS PARTS OF SERN KS AND INTO W-CNTRL MO. THIS ACTIVITY SHOULD
POSE A PRIMARY RISK FOR LARGE HAIL...AND A LESSER THREAT FOR STRONG
TO POTENTIALLY SVR WIND GUSTS. IT IS UNCERTAIN WHETHER TSTMS WILL BE
SUSTAINED FOR LONG ENOUGH TO REQUIRE A WW...BUT TRENDS WILL CONTINUE
TO BE MONITORED.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS A CORRIDOR OF
INTENSIFYING CONVECTION DEVELOPING WITHIN AN ELEVATED BAROCLINIC
ZONE AND AHEAD OF AN APPROACHING UPPER IMPULSE OVER S-CNTRL KS...IN
THE WAKE OF OVERNIGHT CONVECTION WHICH HAS MOVED INTO CNTRL MO AND
HAS WEAKENED. REGIONAL SOUNDINGS /E.G. SGF AND TOP/ SUGGEST THIS
ACTIVITY IS LIKELY ROOTED ABOVE THE BOUNDARY LAYER...AND LOCATED
ALONG THE PERIPHERY OF A PLUME OF STEEP MIDLEVEL LAPSE
RATES...POSING A PRIMARY RISK FOR LARGE HAIL. THERE IS SOME
UNCERTAINTY WHETHER CONVECTION WILL BE SUSTAINED FOR MORE THAN 1-2
HRS WITH NEWD PROGRESSION INTO W-CNTRL MO...WHERE CONVECTION
OVERNIGHT MAY HAVE STABILIZED THE AIR MASS SOMEWHAT.
HOWEVER...SHOULD TRENDS INDICATE CONVECTION WILL MAINTAIN CURRENT
INTENSITY OR STRENGTHEN...AND SHOW SIGNS OF BECOMING ROOTED WITHIN
THE BOUNDARY LAYER...THEN A WW MAY NEED TO BE CONSIDERED.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   38359312 37809417 37429535 37449591 37579620 37929622
            38419550 38869480 39099426 39149368 39089330 38779300
            38359312

000
ACUS11 KWNS 201346
SWOMCD
SPC MCD 201346
MOZ000-KSZ000-201445-

MESOSCALE DISCUSSION 0724
NWS STORM PREDICTION CENTER NORMAN OK
0846 AM CDT MON MAY 20 2013

AREAS AFFECTED...SERN KS...W-CNTRL MO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 201346Z - 201445Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A NARROW CORRIDOR OF TSTMS HAS FORMED WITHIN THE PAST HR
ACROSS PARTS OF SERN KS AND INTO W-CNTRL MO. THIS ACTIVITY SHOULD
POSE A PRIMARY RISK FOR LARGE HAIL...AND A LESSER THREAT FOR STRONG
TO POTENTIALLY SVR WIND GUSTS. IT IS UNCERTAIN WHETHER TSTMS WILL BE
SUSTAINED FOR LONG ENOUGH TO REQUIRE A WW...BUT TRENDS WILL CONTINUE
TO BE MONITORED.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS A CORRIDOR OF
INTENSIFYING CONVECTION DEVELOPING WITHIN AN ELEVATED BAROCLINIC
ZONE AND AHEAD OF AN APPROACHING UPPER IMPULSE OVER S-CNTRL KS...IN
THE WAKE OF OVERNIGHT CONVECTION WHICH HAS MOVED INTO CNTRL MO AND
HAS WEAKENED. REGIONAL SOUNDINGS /E.G. SGF AND TOP/ SUGGEST THIS
ACTIVITY IS LIKELY ROOTED ABOVE THE BOUNDARY LAYER...AND LOCATED
ALONG THE PERIPHERY OF A PLUME OF STEEP MIDLEVEL LAPSE
RATES...POSING A PRIMARY RISK FOR LARGE HAIL. THERE IS SOME
UNCERTAINTY WHETHER CONVECTION WILL BE SUSTAINED FOR MORE THAN 1-2
HRS WITH NEWD PROGRESSION INTO W-CNTRL MO...WHERE CONVECTION
OVERNIGHT MAY HAVE STABILIZED THE AIR MASS SOMEWHAT.
HOWEVER...SHOULD TRENDS INDICATE CONVECTION WILL MAINTAIN CURRENT
INTENSITY OR STRENGTHEN...AND SHOW SIGNS OF BECOMING ROOTED WITHIN
THE BOUNDARY LAYER...THEN A WW MAY NEED TO BE CONSIDERED.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   38359312 37809417 37429535 37449591 37579620 37929622
            38419550 38869480 39099426 39149368 39089330 38779300
            38359312

000
ACUS11 KWNS 201346
SWOMCD
SPC MCD 201346
MOZ000-KSZ000-201445-

MESOSCALE DISCUSSION 0724
NWS STORM PREDICTION CENTER NORMAN OK
0846 AM CDT MON MAY 20 2013

AREAS AFFECTED...SERN KS...W-CNTRL MO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 201346Z - 201445Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A NARROW CORRIDOR OF TSTMS HAS FORMED WITHIN THE PAST HR
ACROSS PARTS OF SERN KS AND INTO W-CNTRL MO. THIS ACTIVITY SHOULD
POSE A PRIMARY RISK FOR LARGE HAIL...AND A LESSER THREAT FOR STRONG
TO POTENTIALLY SVR WIND GUSTS. IT IS UNCERTAIN WHETHER TSTMS WILL BE
SUSTAINED FOR LONG ENOUGH TO REQUIRE A WW...BUT TRENDS WILL CONTINUE
TO BE MONITORED.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS A CORRIDOR OF
INTENSIFYING CONVECTION DEVELOPING WITHIN AN ELEVATED BAROCLINIC
ZONE AND AHEAD OF AN APPROACHING UPPER IMPULSE OVER S-CNTRL KS...IN
THE WAKE OF OVERNIGHT CONVECTION WHICH HAS MOVED INTO CNTRL MO AND
HAS WEAKENED. REGIONAL SOUNDINGS /E.G. SGF AND TOP/ SUGGEST THIS
ACTIVITY IS LIKELY ROOTED ABOVE THE BOUNDARY LAYER...AND LOCATED
ALONG THE PERIPHERY OF A PLUME OF STEEP MIDLEVEL LAPSE
RATES...POSING A PRIMARY RISK FOR LARGE HAIL. THERE IS SOME
UNCERTAINTY WHETHER CONVECTION WILL BE SUSTAINED FOR MORE THAN 1-2
HRS WITH NEWD PROGRESSION INTO W-CNTRL MO...WHERE CONVECTION
OVERNIGHT MAY HAVE STABILIZED THE AIR MASS SOMEWHAT.
HOWEVER...SHOULD TRENDS INDICATE CONVECTION WILL MAINTAIN CURRENT
INTENSITY OR STRENGTHEN...AND SHOW SIGNS OF BECOMING ROOTED WITHIN
THE BOUNDARY LAYER...THEN A WW MAY NEED TO BE CONSIDERED.

..ROGERS/KERR.. 05/20/2013

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

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   38359312 37809417 37429535 37449591 37579620 37929622
            38419550 38869480 39099426 39149368 39089330 38779300
            38359312

000
ACUS01 KWNS 201219
SWODY1
SPC AC 201217

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0717 AM CDT MON MAY 20 2013

VALID 201300Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
PARTS OF NORTH TX...CENTRAL AND EASTERN OK...NORTHWEST AR...EXTREME
SOUTHEAST KS...AND SOUTHERN MO....

...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO MUCH OF
THE UPPER MS VALLEY AND GREAT LAKES REGION....

...TX/OK/AR/KS/MO...
MORNING WATER VAPOR LOOPS SHOW A BROAD UPPER TROUGH OVER THE WESTERN
AND CENTRAL STATES...WITH A PROGRESSIVE SHORTWAVE TROUGH TRACKING
EASTWARD ACROSS NORTHERN NM.  THIS FEATURE WILL MOVE INTO THE
SOUTHERN PLAINS BY EARLY AFTERNOON...HELPING TO INITIATE ANOTHER
ROUND OF STRONG TO SEVERE THUNDERSTORMS OVER THE SOUTHERN PLAINS.

A SURFACE COLD FRONT CURRENTLY EXTENDS ROUGHLY FROM LTS-BVO.  THIS
FRONT IS LIKELY TO MOVE SLIGHTLY SOUTHEASTWARD TODAY AND WILL
PROVIDE THE FOCUS FOR AFTERNOON THUNDERSTORM DEVELOPMENT.  VARIOUS
MESOSCALE MODELS DIFFER ON TIMING OF STRONG/SEVERE STORMS...BUT
AGREE ON STORMS FORMING OVER CENTRAL OK BY ABOUT 20Z AND BUILDING
QUICKLY NORTHEASTWARD INTO SOUTHEAST KS AND WESTERN MO.  THE INITIAL
STORMS WILL LIKELY BE SUPERCELLUAR WITH VERY LARGE HAIL...DAMAGING
WINDS...AND TORNADOES POSSIBLE.  THOSE STORMS THAT FORM OVER
SOUTHERN OK INTO NORTH TX APPEAR TO HAVE THE GREATEST CHANCE OF
REMAINING DISCRETE AND POSING A RISK OF SIGNIFICANT SEVERE WEATHER
FOR SEVERAL HOURS INTO THE EVENING.  MEANWHILE...STORMS THAT FORM
FROM CENTRAL OK NORTHEASTWARD INTO SOUTHEAST KS AND MO APPEAR LIKELY
TO ORGANIZE INTO BROKEN LINES AND CLUSTERS BY EARLY EVENING CAPABLE
OF WIDESPREAD DAMAGING WINDS...LARGE HAIL...AND A FEW TORNADOES.
SIMILAR TO YESTERDAY...MID LEVEL LAPSE RATES OF 7.5-8.0 C/KM...VERY
LARGE CAPE...AND FAVORABLE SHEAR VALUES WILL POSE A RISK OF ISOLATED
STRONG TORNADOES ACROSS PORTIONS OF THE MODERATE RISK AREA.

...UPPER MS VALLEY AND WESTERN GREAT LAKES...
EARLY VISIBLE SATELLITE IMAGERY SHOWS ONLY BROKEN CLOUD COVER OVER
PARTS OF IA/WI EASTWARD INTO MI/OH.  RELATIVELY STRONG DAYTIME
HEATING AND LITTLE CAP SHOULD RESULT IN SCATTERED THUNDERSTORMS
TODAY AND TONIGHT TO THE EAST OF A SURFACE LOW OVER MN.  MLCAPE
VALUES OF 1500-2000 J/KG WILL PROMOTE VIGOROUS UPDRAFTS IN THIS
REGION...WHILE SUFFICIENTLY STRONG VERTICAL SHEAR HELPS TO ORGANIZE
THE CONVECTION.  PRESENT INDICATIONS ARE THAT MULTIPLE
LINES/CLUSTERS OF THUNDERSTORMS WILL AFFECT THIS REGION...WITH A FEW
SUPERCELLS POSSIBLE.  HAIL AND DAMAGING WINDS ARE THE MAIN
THREATS...BUT ISOLATED TORNADOES CANNOT BE RULED OUT.

...TX...
SOUTH OF THE MODERATE RISK AREA IN TX...CONFIDENCE IS A LITTLE
HIGHER TODAY COMPARED TO LAST FEW DAYS THAT ISOLATED STORMS WILL
FORM ALONG THE DRYLINE.  ANY STORM THAT CAN FORM IN THIS AREA WILL
POSE A RISK OF VERY LARGE HAIL AND DAMAGING WINDS FOR A FEW HOURS
THIS EVENING.

..HART/LEITMAN.. 05/20/2013

000
ACUS01 KWNS 201219
SWODY1
SPC AC 201217

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0717 AM CDT MON MAY 20 2013

VALID 201300Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT OVER
PARTS OF NORTH TX...CENTRAL AND EASTERN OK...NORTHWEST AR...EXTREME
SOUTHEAST KS...AND SOUTHERN MO....

...THERE IS A SLGT RISK OF SVR TSTMS FROM CENTRAL TX INTO MUCH OF
THE UPPER MS VALLEY AND GREAT LAKES REGION....

...TX/OK/AR/KS/MO...
MORNING WATER VAPOR LOOPS SHOW A BROAD UPPER TROUGH OVER THE WESTERN
AND CENTRAL STATES...WITH A PROGRESSIVE SHORTWAVE TROUGH TRACKING
EASTWARD ACROSS NORTHERN NM.  THIS FEATURE WILL MOVE INTO THE
SOUTHERN PLAINS BY EARLY AFTERNOON...HELPING TO INITIATE ANOTHER
ROUND OF STRONG TO SEVERE THUNDERSTORMS OVER THE SOUTHERN PLAINS.

A SURFACE COLD FRONT CURRENTLY EXTENDS ROUGHLY FROM LTS-BVO.  THIS
FRONT IS LIKELY TO MOVE SLIGHTLY SOUTHEASTWARD TODAY AND WILL
PROVIDE THE FOCUS FOR AFTERNOON THUNDERSTORM DEVELOPMENT.  VARIOUS
MESOSCALE MODELS DIFFER ON TIMING OF STRONG/SEVERE STORMS...BUT
AGREE ON STORMS FORMING OVER CENTRAL OK BY ABOUT 20Z AND BUILDING
QUICKLY NORTHEASTWARD INTO SOUTHEAST KS AND WESTERN MO.  THE INITIAL
STORMS WILL LIKELY BE SUPERCELLUAR WITH VERY LARGE HAIL...DAMAGING
WINDS...AND TORNADOES POSSIBLE.  THOSE STORMS THAT FORM OVER
SOUTHERN OK INTO NORTH TX APPEAR TO HAVE THE GREATEST CHANCE OF
REMAINING DISCRETE AND POSING A RISK OF SIGNIFICANT SEVERE WEATHER
FOR SEVERAL HOURS INTO THE EVENING.  MEANWHILE...STORMS THAT FORM
FROM CENTRAL OK NORTHEASTWARD INTO SOUTHEAST KS AND MO APPEAR LIKELY
TO ORGANIZE INTO BROKEN LINES AND CLUSTERS BY EARLY EVENING CAPABLE
OF WIDESPREAD DAMAGING WINDS...LARGE HAIL...AND A FEW TORNADOES.
SIMILAR TO YESTERDAY...MID LEVEL LAPSE RATES OF 7.5-8.0 C/KM...VERY
LARGE CAPE...AND FAVORABLE SHEAR VALUES WILL POSE A RISK OF ISOLATED
STRONG TORNADOES ACROSS PORTIONS OF THE MODERATE RISK AREA.

...UPPER MS VALLEY AND WESTERN GREAT LAKES...
EARLY VISIBLE SATELLITE IMAGERY SHOWS ONLY BROKEN CLOUD COVER OVER
PARTS OF IA/WI EASTWARD INTO MI/OH.  RELATIVELY STRONG DAYTIME
HEATING AND LITTLE CAP SHOULD RESULT IN SCATTERED THUNDERSTORMS
TODAY AND TONIGHT TO THE EAST OF A SURFACE LOW OVER MN.  MLCAPE
VALUES OF 1500-2000 J/KG WILL PROMOTE VIGOROUS UPDRAFTS IN THIS
REGION...WHILE SUFFICIENTLY STRONG VERTICAL SHEAR HELPS TO ORGANIZE
THE CONVECTION.  PRESENT INDICATIONS ARE THAT MULTIPLE
LINES/CLUSTERS OF THUNDERSTORMS WILL AFFECT THIS REGION...WITH A FEW
SUPERCELLS POSSIBLE.  HAIL AND DAMAGING WINDS ARE THE MAIN
THREATS...BUT ISOLATED TORNADOES CANNOT BE RULED OUT.

...TX...
SOUTH OF THE MODERATE RISK AREA IN TX...CONFIDENCE IS A LITTLE
HIGHER TODAY COMPARED TO LAST FEW DAYS THAT ISOLATED STORMS WILL
FORM ALONG THE DRYLINE.  ANY STORM THAT CAN FORM IN THIS AREA WILL
POSE A RISK OF VERY LARGE HAIL AND DAMAGING WINDS FOR A FEW HOURS
THIS EVENING.

..HART/LEITMAN.. 05/20/2013

000
ACUS11 KWNS 200744
SWOMCD
SPC MCD 200744
MOZ000-OKZ000-KSZ000-200945-

MESOSCALE DISCUSSION 0723
NWS STORM PREDICTION CENTER NORMAN OK
0244 AM CDT MON MAY 20 2013

AREAS AFFECTED...NERN OK...FAR NWRN AR AND FAR SERN KS

CONCERNING...TORNADO WATCH 188...

VALID 200744Z - 200945Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 188 CONTINUES.

SUMMARY...ISOLATED HAIL WILL BE THE PRIMARY THREAT WITH STORMS
CURRENTLY LOCATED IN OSAGE COUNTY OK...AND TO THE N OF WW 188 IN FAR
SERN KS.  HEAVY RAINFALL WILL BE A THREAT AS WELL AS STORMS SHOULD
CONTINUE TO TRAIN ENEWD FROM NWRN-NRN OSAGE COUNTY THROUGH THE FAR
SERN KS COUNTIES /FOR ADDITIONAL HEAVY RAINFALL DETAILS...REFER TO
THE MESOSCALE PRECIPITATION DISCUSSIONS ISSUED BY WPC/.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY SHOWED THE STORMS THAT
WERE AFFECTING NERN OK AT THE ISSUANCE OF WW 188 ARE NOW MOVING EWD
THROUGH CENTRAL/SOUTH CENTRAL MO. THE ATTENDANT OUTFLOW BOUNDARY
EXTENDED SWWD THROUGH WRIGHT TO TANEY COUNTIES MO...AND THEN WSWWD
THROUGH FAR NWRN AR INTO NERN OK TO THE NORTH OF KTUL TO PAWNEE
COUNTY.  A STABILIZED BOUNDARY LAYER HAS GREATLY REDUCED THE TORNADO
THREAT...WHILE STRONGER ELEVATED STORMS LOCATED IN NRN OSAGE COUNTY
OK TO THE FAR SERN KS COUNTIES POSE AN ISOLATED HAIL THREAT.

CYCLONIC MIDLEVEL WINDS AND 500 MB TEMPS AOB -15 C WILL CONTINUE TO
SPREAD ENEWD ACROSS THE DISCUSSION AREA WITH 8 C/KM MIDLEVEL LAPSE
RATES.  STRONG LOW LEVEL WAA PER A VEERING SLY 60-70 KT LLJ WILL
MAINTAIN TSTM DEVELOPMENT THROUGH 12Z FROM NRN OSAGE COUNTY OK INTO
FAR SERN KS. EFFECTIVE BULK SHEAR EXCEEDING 50 KT WILL SUPPORT STORM
ORGANIZATION WITH A CONTINUED THREAT FOR ISOLATED HAIL GIVEN
FAVORABLE CLOUD LAYER THERMODYNAMICS. RECENT RADAR TRENDS IN OSAGE
COUNTY INDICATED THE WRN MOST STORMS HAVE BEGUN TO MOVE ENEWD...
SUGGESTING THIS MAY BE IN RESPONSE TO A VEERING TREND OF THE LLJ TO
SWLY PER AREA VWPS.

..PETERS.. 05/20/2013

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

ATTN...WFO...SGF...TSA...ICT...OUN...

LAT...LON   36339465 36189659 36419696 37049683 37329588 37459477
            37389459 36339465

000
ACUS11 KWNS 200744
SWOMCD
SPC MCD 200744
MOZ000-OKZ000-KSZ000-200945-

MESOSCALE DISCUSSION 0723
NWS STORM PREDICTION CENTER NORMAN OK
0244 AM CDT MON MAY 20 2013

AREAS AFFECTED...NERN OK...FAR NWRN AR AND FAR SERN KS

CONCERNING...TORNADO WATCH 188...

VALID 200744Z - 200945Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 188 CONTINUES.

SUMMARY...ISOLATED HAIL WILL BE THE PRIMARY THREAT WITH STORMS
CURRENTLY LOCATED IN OSAGE COUNTY OK...AND TO THE N OF WW 188 IN FAR
SERN KS.  HEAVY RAINFALL WILL BE A THREAT AS WELL AS STORMS SHOULD
CONTINUE TO TRAIN ENEWD FROM NWRN-NRN OSAGE COUNTY THROUGH THE FAR
SERN KS COUNTIES /FOR ADDITIONAL HEAVY RAINFALL DETAILS...REFER TO
THE MESOSCALE PRECIPITATION DISCUSSIONS ISSUED BY WPC/.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY SHOWED THE STORMS THAT
WERE AFFECTING NERN OK AT THE ISSUANCE OF WW 188 ARE NOW MOVING EWD
THROUGH CENTRAL/SOUTH CENTRAL MO. THE ATTENDANT OUTFLOW BOUNDARY
EXTENDED SWWD THROUGH WRIGHT TO TANEY COUNTIES MO...AND THEN WSWWD
THROUGH FAR NWRN AR INTO NERN OK TO THE NORTH OF KTUL TO PAWNEE
COUNTY.  A STABILIZED BOUNDARY LAYER HAS GREATLY REDUCED THE TORNADO
THREAT...WHILE STRONGER ELEVATED STORMS LOCATED IN NRN OSAGE COUNTY
OK TO THE FAR SERN KS COUNTIES POSE AN ISOLATED HAIL THREAT.

CYCLONIC MIDLEVEL WINDS AND 500 MB TEMPS AOB -15 C WILL CONTINUE TO
SPREAD ENEWD ACROSS THE DISCUSSION AREA WITH 8 C/KM MIDLEVEL LAPSE
RATES.  STRONG LOW LEVEL WAA PER A VEERING SLY 60-70 KT LLJ WILL
MAINTAIN TSTM DEVELOPMENT THROUGH 12Z FROM NRN OSAGE COUNTY OK INTO
FAR SERN KS. EFFECTIVE BULK SHEAR EXCEEDING 50 KT WILL SUPPORT STORM
ORGANIZATION WITH A CONTINUED THREAT FOR ISOLATED HAIL GIVEN
FAVORABLE CLOUD LAYER THERMODYNAMICS. RECENT RADAR TRENDS IN OSAGE
COUNTY INDICATED THE WRN MOST STORMS HAVE BEGUN TO MOVE ENEWD...
SUGGESTING THIS MAY BE IN RESPONSE TO A VEERING TREND OF THE LLJ TO
SWLY PER AREA VWPS.

..PETERS.. 05/20/2013

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

ATTN...WFO...SGF...TSA...ICT...OUN...

LAT...LON   36339465 36189659 36419696 37049683 37329588 37459477
            37389459 36339465

000
ACUS03 KWNS 200728
SWODY3
SPC AC 200727

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0227 AM CDT MON MAY 20 2013

VALID 221200Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS LOWER GREAT LAKES/MID AND UPPER
OH VALLEY REGIONS...

...SYNOPSIS...
AS A LARGE UPPER LOW/TROUGH SETTLES SLOWLY SEWD INTO THE WRN
CONUS...A SECOND UPPER TROUGH EXITING THE CENTRAL U.S. WILL MOVE
SLOWLY EWD ACROSS THE MIDWEST/MID SOUTH REGIONS.  AT THE SURFACE...A
STRONG COLD FRONT WILL CONTINUE TO MOVE SLOWLY ACROSS THE GREAT
BASIN AHEAD OF THE WRN UPPER TROUGH...WHILE A MUCH WEAKER COOL FRONT
CROSSES THE LOWER GREAT LAKES/OH VALLEY/MID SOUTH THROUGH THE
PERIOD.

...WRN PORTIONS OF NY/PA WWD ACROSS THE MID OH VALLEY...
WIDESPREAD PRECIPITATION AND CLOUD COVER FROM THE START OF THE
PERIOD ONWARD IS EXPECTED ACROSS THE SLIGHT RISK AREA...WHICH SHOULD
GREATLY HINDER DESTABILIZATION POTENTIAL ACROSS MOST AREAS.
STILL...WITH MODERATE FLOW /30 TO 45 KT/ THROUGH MOST OF THE LOWER
HALF OF THE TROPOSPHERE ACROSS THE OH VALLEY REGION AHEAD OF THE
WEAK/ADVANCING FRONT...SOME POTENTIAL FOR SEVERE WEATHER -- MAINLY
IN THE FORM OF LOCALLY DAMAGING WINDS -- APPEARS TO EXIST.
THUS...WILL INTRODUCE 15%/SLIGHT RISK ACROSS THE MID AND UPPER OH
VALLEY AND LOWER GREAT LAKES REGION TO COVER A POSSIBLE
AFTERNOON/EVENING RAMP-UP IN CONVECTIVE INTENSITY.

...SABINE AND LOWER MS RIVER VALLEYS AND VICINITY...
SLIGHTLY ENHANCED FLOW ALOFT ACCOMPANYING A VORT MAX FORECAST TO BE
CROSSING E TX EARLY IN THE PERIOD WILL SUPPORT MODEST SHEAR ACROSS
LA AND SURROUNDING AREAS.  WHILE QUESTIONS REGARDING DEGREE OF
DESTABILIZATION EXIST DUE TO REMNANT CLOUDS/PRECIPITATION...THE
ENHANCED FLOW FIELD ALOFT MAY SUPPORT A FEW STRONGER CELLS AND THUS
LOW-PROBABILITY SEVERE POTENTIAL.

...TX...
WITH MODEST SHEAR AND AFTERNOON DESTABILIZATION FORECAST ACROSS
TX...SOME SEVERE POTENTIAL IS EVIDENT.  HOWEVER...WITH
RIDGING/SUBSIDENCE FORECAST TO OVERSPREAD THE REGION FROM THE
W...CONVECTIVE DEVELOPMENT SHOULD REMAIN LIMITED/ISOLATED.
THUS...WILL CARRY ONLY LOW /5%/ SEVERE PROBABILITY ACROSS THE SRN
PLAINS.

..GOSS.. 05/20/2013

000
ACUS03 KWNS 200728
SWODY3
SPC AC 200727

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0227 AM CDT MON MAY 20 2013

VALID 221200Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS LOWER GREAT LAKES/MID AND UPPER
OH VALLEY REGIONS...

...SYNOPSIS...
AS A LARGE UPPER LOW/TROUGH SETTLES SLOWLY SEWD INTO THE WRN
CONUS...A SECOND UPPER TROUGH EXITING THE CENTRAL U.S. WILL MOVE
SLOWLY EWD ACROSS THE MIDWEST/MID SOUTH REGIONS.  AT THE SURFACE...A
STRONG COLD FRONT WILL CONTINUE TO MOVE SLOWLY ACROSS THE GREAT
BASIN AHEAD OF THE WRN UPPER TROUGH...WHILE A MUCH WEAKER COOL FRONT
CROSSES THE LOWER GREAT LAKES/OH VALLEY/MID SOUTH THROUGH THE
PERIOD.

...WRN PORTIONS OF NY/PA WWD ACROSS THE MID OH VALLEY...
WIDESPREAD PRECIPITATION AND CLOUD COVER FROM THE START OF THE
PERIOD ONWARD IS EXPECTED ACROSS THE SLIGHT RISK AREA...WHICH SHOULD
GREATLY HINDER DESTABILIZATION POTENTIAL ACROSS MOST AREAS.
STILL...WITH MODERATE FLOW /30 TO 45 KT/ THROUGH MOST OF THE LOWER
HALF OF THE TROPOSPHERE ACROSS THE OH VALLEY REGION AHEAD OF THE
WEAK/ADVANCING FRONT...SOME POTENTIAL FOR SEVERE WEATHER -- MAINLY
IN THE FORM OF LOCALLY DAMAGING WINDS -- APPEARS TO EXIST.
THUS...WILL INTRODUCE 15%/SLIGHT RISK ACROSS THE MID AND UPPER OH
VALLEY AND LOWER GREAT LAKES REGION TO COVER A POSSIBLE
AFTERNOON/EVENING RAMP-UP IN CONVECTIVE INTENSITY.

...SABINE AND LOWER MS RIVER VALLEYS AND VICINITY...
SLIGHTLY ENHANCED FLOW ALOFT ACCOMPANYING A VORT MAX FORECAST TO BE
CROSSING E TX EARLY IN THE PERIOD WILL SUPPORT MODEST SHEAR ACROSS
LA AND SURROUNDING AREAS.  WHILE QUESTIONS REGARDING DEGREE OF
DESTABILIZATION EXIST DUE TO REMNANT CLOUDS/PRECIPITATION...THE
ENHANCED FLOW FIELD ALOFT MAY SUPPORT A FEW STRONGER CELLS AND THUS
LOW-PROBABILITY SEVERE POTENTIAL.

...TX...
WITH MODEST SHEAR AND AFTERNOON DESTABILIZATION FORECAST ACROSS
TX...SOME SEVERE POTENTIAL IS EVIDENT.  HOWEVER...WITH
RIDGING/SUBSIDENCE FORECAST TO OVERSPREAD THE REGION FROM THE
W...CONVECTIVE DEVELOPMENT SHOULD REMAIN LIMITED/ISOLATED.
THUS...WILL CARRY ONLY LOW /5%/ SEVERE PROBABILITY ACROSS THE SRN
PLAINS.

..GOSS.. 05/20/2013

000
ACUS11 KWNS 200642
SWOMCD
SPC MCD 200641 COR
WIZ000-ILZ000-200800-

MESOSCALE DISCUSSION 0722
NWS STORM PREDICTION CENTER NORMAN OK
0141 AM CDT MON MAY 20 2013

AREAS AFFECTED...PARTS OF SRN/CENTRAL WI

CONCERNING...TORNADO WATCH 187...

VALID 200641Z - 200800Z

CORRECTED TO CHANGE WATCH TYPE FOR WW 187.

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 187 CONTINUES.

SUMMARY...PRIMARY THREAT THROUGH 08Z WILL BE LOCALLY STRONG/DAMAGING
WINDS...WHILE THE TORNADO THREAT HAS CONTINUED TO DIMINISH.  THE
DAMAGING WIND THREAT IS FORECAST TO BECOME MORE LIMITED WITH NEWD
EXTENT...THOUGH A NON-ZERO THREAT WILL EXTENT INTO PARTS OF
CENTRAL-EAST CENTRAL WI TO THE N/NE OF WW 187.

COUNTIES CAN CONTINUE TO BE CANCELLED WITH THE PASSAGE OF THE
CONVECTIVE LINE.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY SHOWED A LINE OF
STORMS MOVING ENEWD AT 40 KT WHICH COULD CONTINUE TO POSE A THREAT
FOR LOCALLY STRONG/DAMAGING WIND GUSTS INTO PARTS OF CENTRAL WI
DURING THE EARLY OVERNIGHT PERIOD.  DESPITE CONTINUED BOUNDARY LAYER
STABILIZATION...STRONGER WIND GUSTS HAVE BEEN ABLE TO REACH THE
SURFACE /52 KT GUST AT KLNR AT 0537Z/.  THUS...THE CURRENT SPEED OF
THE STORMS COMBINED WITH 50-60 KT SLY LLJ ACROSS THIS REGION MAY
ALLOW FOR ADDITIONAL STRONGER GUSTS TO REACH THE SURFACE THROUGH
08Z.

OVERALL REDUCTION IN LIGHTNING COVERAGE AND CAPPI RADAR IMAGERY AS
STORMS MOVE AWAY FROM GREATER INSTABILITY SUGGESTS THE DIMINISHING
TREND IN THE SEVERE WEATHER THREAT WILL PERSIST...WITH NEW WW
ISSUANCE UNLIKELY.

..PETERS/HART.. 05/20/2013

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

ATTN...WFO...GRB...LOT...MKX...DVN...ARX...

LAT...LON   42568874 42398966 43328980 43949008 44329020 44428980
            44468911 44238832 43698821 43068848 42568874

000
ACUS11 KWNS 200642
SWOMCD
SPC MCD 200641 COR
WIZ000-ILZ000-200800-

MESOSCALE DISCUSSION 0722
NWS STORM PREDICTION CENTER NORMAN OK
0141 AM CDT MON MAY 20 2013

AREAS AFFECTED...PARTS OF SRN/CENTRAL WI

CONCERNING...TORNADO WATCH 187...

VALID 200641Z - 200800Z

CORRECTED TO CHANGE WATCH TYPE FOR WW 187.

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 187 CONTINUES.

SUMMARY...PRIMARY THREAT THROUGH 08Z WILL BE LOCALLY STRONG/DAMAGING
WINDS...WHILE THE TORNADO THREAT HAS CONTINUED TO DIMINISH.  THE
DAMAGING WIND THREAT IS FORECAST TO BECOME MORE LIMITED WITH NEWD
EXTENT...THOUGH A NON-ZERO THREAT WILL EXTENT INTO PARTS OF
CENTRAL-EAST CENTRAL WI TO THE N/NE OF WW 187.

COUNTIES CAN CONTINUE TO BE CANCELLED WITH THE PASSAGE OF THE
CONVECTIVE LINE.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY SHOWED A LINE OF
STORMS MOVING ENEWD AT 40 KT WHICH COULD CONTINUE TO POSE A THREAT
FOR LOCALLY STRONG/DAMAGING WIND GUSTS INTO PARTS OF CENTRAL WI
DURING THE EARLY OVERNIGHT PERIOD.  DESPITE CONTINUED BOUNDARY LAYER
STABILIZATION...STRONGER WIND GUSTS HAVE BEEN ABLE TO REACH THE
SURFACE /52 KT GUST AT KLNR AT 0537Z/.  THUS...THE CURRENT SPEED OF
THE STORMS COMBINED WITH 50-60 KT SLY LLJ ACROSS THIS REGION MAY
ALLOW FOR ADDITIONAL STRONGER GUSTS TO REACH THE SURFACE THROUGH
08Z.

OVERALL REDUCTION IN LIGHTNING COVERAGE AND CAPPI RADAR IMAGERY AS
STORMS MOVE AWAY FROM GREATER INSTABILITY SUGGESTS THE DIMINISHING
TREND IN THE SEVERE WEATHER THREAT WILL PERSIST...WITH NEW WW
ISSUANCE UNLIKELY.

..PETERS/HART.. 05/20/2013

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

ATTN...WFO...GRB...LOT...MKX...DVN...ARX...

LAT...LON   42568874 42398966 43328980 43949008 44329020 44428980
            44468911 44238832 43698821 43068848 42568874

000
ACUS11 KWNS 200636
SWOMCD
SPC MCD 200636
WIZ000-ILZ000-200800-

MESOSCALE DISCUSSION 0722
NWS STORM PREDICTION CENTER NORMAN OK
0136 AM CDT MON MAY 20 2013

AREAS AFFECTED...PARTS OF SRN/CENTRAL WI

CONCERNING...SEVERE THUNDERSTORM WATCH 187...

VALID 200636Z - 200800Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 187
CONTINUES.

SUMMARY...PRIMARY THREAT THROUGH 08Z WILL BE LOCALLY STRONG/DAMAGING
WINDS...WHILE THE TORNADO THREAT HAS CONTINUED TO DIMINISH.  THE
DAMAGING WIND THREAT IS FORECAST TO BECOME MORE LIMITED WITH NEWD
EXTENT...THOUGH A NON-ZERO THREAT WILL EXTENT INTO PARTS OF
CENTRAL-EAST CENTRAL WI TO THE N/NE OF WW 187.

COUNTIES CAN CONTINUE TO BE CANCELLED WITH THE PASSAGE OF THE
CONVECTIVE LINE.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY SHOWED A LINE OF
STORMS MOVING ENEWD AT 40 KT WHICH COULD CONTINUE TO POSE A THREAT
FOR LOCALLY STRONG/DAMAGING WIND GUSTS INTO PARTS OF CENTRAL WI
DURING THE EARLY OVERNIGHT PERIOD.  DESPITE CONTINUED BOUNDARY LAYER
STABILIZATION...STRONGER WIND GUSTS HAVE BEEN ABLE TO REACH THE
SURFACE /52 KT GUST AT KLNR AT 0537Z/.  THUS...THE CURRENT SPEED OF
THE STORMS COMBINED WITH 50-60 KT SLY LLJ ACROSS THIS REGION MAY
ALLOW FOR ADDITIONAL STRONGER GUSTS TO REACH THE SURFACE THROUGH
08Z.

OVERALL REDUCTION IN LIGHTNING COVERAGE AND CAPPI RADAR IMAGERY AS
STORMS MOVE AWAY FROM GREATER INSTABILITY SUGGESTS THE DIMINISHING
TREND IN THE SEVERE WEATHER THREAT WILL PERSIST...WITH NEW WW
ISSUANCE UNLIKELY.

..PETERS/HART.. 05/20/2013

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

ATTN...WFO...GRB...LOT...MKX...DVN...ARX...

LAT...LON   42568874 42398966 43328980 43949008 44329020 44428980
            44468911 44238832 43698821 43068848 42568874

000
ACUS11 KWNS 200636
SWOMCD
SPC MCD 200636
WIZ000-ILZ000-200800-

MESOSCALE DISCUSSION 0722
NWS STORM PREDICTION CENTER NORMAN OK
0136 AM CDT MON MAY 20 2013

AREAS AFFECTED...PARTS OF SRN/CENTRAL WI

CONCERNING...SEVERE THUNDERSTORM WATCH 187...

VALID 200636Z - 200800Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 187
CONTINUES.

SUMMARY...PRIMARY THREAT THROUGH 08Z WILL BE LOCALLY STRONG/DAMAGING
WINDS...WHILE THE TORNADO THREAT HAS CONTINUED TO DIMINISH.  THE
DAMAGING WIND THREAT IS FORECAST TO BECOME MORE LIMITED WITH NEWD
EXTENT...THOUGH A NON-ZERO THREAT WILL EXTENT INTO PARTS OF
CENTRAL-EAST CENTRAL WI TO THE N/NE OF WW 187.

COUNTIES CAN CONTINUE TO BE CANCELLED WITH THE PASSAGE OF THE
CONVECTIVE LINE.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY SHOWED A LINE OF
STORMS MOVING ENEWD AT 40 KT WHICH COULD CONTINUE TO POSE A THREAT
FOR LOCALLY STRONG/DAMAGING WIND GUSTS INTO PARTS OF CENTRAL WI
DURING THE EARLY OVERNIGHT PERIOD.  DESPITE CONTINUED BOUNDARY LAYER
STABILIZATION...STRONGER WIND GUSTS HAVE BEEN ABLE TO REACH THE
SURFACE /52 KT GUST AT KLNR AT 0537Z/.  THUS...THE CURRENT SPEED OF
THE STORMS COMBINED WITH 50-60 KT SLY LLJ ACROSS THIS REGION MAY
ALLOW FOR ADDITIONAL STRONGER GUSTS TO REACH THE SURFACE THROUGH
08Z.

OVERALL REDUCTION IN LIGHTNING COVERAGE AND CAPPI RADAR IMAGERY AS
STORMS MOVE AWAY FROM GREATER INSTABILITY SUGGESTS THE DIMINISHING
TREND IN THE SEVERE WEATHER THREAT WILL PERSIST...WITH NEW WW
ISSUANCE UNLIKELY.

..PETERS/HART.. 05/20/2013

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

ATTN...WFO...GRB...LOT...MKX...DVN...ARX...

LAT...LON   42568874 42398966 43328980 43949008 44329020 44428980
            44468911 44238832 43698821 43068848 42568874

000
ACUS01 KWNS 200620
SWODY1
SPC AC 200617

DAY 1 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0117 AM CDT MON MAY 20 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF OK/FAR
SOUTHEAST KS/SOUTHERN MO/NORTHWEST AR/FAR NORTH TX...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE
MIDWEST/GREAT LAKES REGION...

CORRECTED FOR AREAS IN MODERATE RISK HEADLINE

...SYNOPSIS...
YET ANOTHER ACTIVE/RELATIVELY WIDESPREAD SEVERE WEATHER DAY IS
LIKELY ACROSS PORTIONS OF THE SOUTHERN PLAINS TO MIDWEST TODAY AND
TONIGHT. A PROMINENT CENTRAL CONUS UPPER TROUGH WILL CONTINUE A
GENERAL EASTWARD ADVANCEMENT THROUGH TONIGHT...WITH A LEAD/CLOSED
UPPER LOW PIVOTING OVER THE DAKOTAS/UPPER MIDWEST. A SOUTHERN STREAM
SHORTWAVE TROUGH/MODERATELY STRONG POLAR JET WILL EJECT
EAST-NORTHEASTWARD OVER THE SOUTHERN ROCKIES TO THE SOUTHERN
PLAINS/OZARKS...WITH SEVERE TSTMS INCREASINGLY LIKELY BY PEAK
HEATING AND CONTINUING INTO TONIGHT.

MEANWHILE...A LINGERING UPPER LOW OVER THE COASTAL SOUTHEAST STATES
WILL CONTRIBUTE TO ANOTHER DAY OF WIDELY SCATTERED TO SCATTERED
TSTMS OVER THE REGION...SOME OF WHICH MAY AGAIN BE STRONG OR SEVERE.

...SOUTHERN PLAINS/OZARKS/MIDDLE MS VALLEY...
UNDER THE INFLUENCE OF BROAD/MODERATELY STRONG CYCLONIC FLOW
ALOFT...THE AIRMASS IS EXPECTED TO AGAIN BECOME QUITE UNSTABLE
ACROSS MUCH OF THE REGION BY THE AFTERNOON BENEATH AN ELEVATED MIXED
LAYER EXTENDING ACROSS THE SOUTHERN PLAINS INTO PARTS OF THE OZARKS
AND LOWER/MIDDLE MS VALLEY. MIDDLE/UPPER 60S AND SOME LOWER 70S F
SURFACE DEWPOINTS WILL BE QUITE COMMON WITHIN A SPATIALLY BROAD WARM
SECTOR AHEAD OF A COLD FRONT EXTENDING FROM AN EASTERN DAKOTAS/MN
SURFACE LOW SOUTHWESTWARD TO NEAR THE KANSAS CITY AREA/EASTERN KS
AND WESTERN OK...AND AHEAD OF A DRYLINE EXTENDING FROM SOUTHWEST OK
SOUTHWARD INTO WESTERN NORTH TX/WEST-CENTRAL TX.

OUTFLOW REMNANTS FROM OVERNIGHT/EARLY DAY CONVECTION ACROSS THE
OZARKS/MIDDLE MS VALLEY WILL LIKELY BE A FACTOR INTO THIS
AFTERNOON...POSSIBLY AS A RENEWED FOCUS FOR SEVERE TSTM
REDEVELOPMENT...WITH THE MOST AGGRESSIVE HEATING/DESTABILIZATION ON
THE WESTERN FRINGES OF THIS ACTIVITY ACROSS THE SOUTHERN PLAINS AND
PERHAPS LOWER MO VALLEY JUST AHEAD OF THE TRUE SYNOPTIC COLD FRONT.
SEVERE TSTMS CAPABLE OF HAIL/DAMAGING WINDS AND SOME TORNADO THREAT
WILL BE POSSIBLE ALONG THIS FRONTAL ZONE ACROSS EASTERN KS/NORTHERN
MO INTO THE UPPER MS VALLEY...WITH A PERSISTENT/EAST-NORTHEASTWARD
DEVELOPING SEVERE THREAT INTO THE EVENING.

THAT SAID...THE MOST INTENSE/MOST PROBABLE SEVERE STORMS ARE
ANTICIPATED A BIT FARTHER SOUTH-SOUTHWEST ACROSS THE SOUTHERN
PLAINS/OZARKS BY MID/LATE AFTERNOON INTO TONIGHT. THIS INCLUDES A
PORTION OF THE SYNOPTIC FRONT AND/OR OUTFLOW ACROSS FAR SOUTHEAST
KS/SOUTHWEST MO...AREAS ROUGHLY PARALLEL AND NORTHWEST OF THE I-44
CORRIDOR...BUT ESPECIALLY SOUTH-SOUTHWESTWARD INTO MUCH OF THE
MIDDLE PART OF OK /POTENTIALLY INCLUDING OKC METRO/...TO NEAR THE
HEAT-AIDED SURFACE LOW AND SOUTHWARD-EXTENDING SHARPENING DRYLINE
INTO THE WESTERN PART OF NORTH TX/WEST-CENTRAL TX. IN THIS
CORRIDOR...MLCAPE VALUES ARE LIKELY TO EXCEED 2500-3000 J/KG BY
AFTERNOON WITHIN THE WARM SECTOR ACROSS OK AND
WEST-CENTRAL/NORTH-CENTRAL TX...AND PERHAPS INTO PARTS OF SOUTHEAST
KS AND MO. WITH BROAD/MODERATELY STRONG CYCLONIC MID-HIGH LEVEL FLOW
/50+ KT AT 500 MB/ OVER THE REGION...40-50 KT OF EFFECTIVE SHEAR
WILL COINCIDE WITH THE MAJORITY OF THE EFFECTIVE FRONTAL ZONE AND/OR
DRYLINE ACROSS OK/EXTREME NORTH TX INTO SOUTHEAST KS AND THE OZARKS.

THE DEGREE OF SHEAR AND MOISTURE/INSTABILITY WITHIN THE WARM SECTOR
WILL FAVOR SCATTERED TO NUMEROUS SUPERCELL STRUCTURES...AT LEAST
THROUGH MID-EVENING OF THE CONVECTIVE CYCLE. VERY LARGE HAIL AND
TORNADOES ARE POSSIBLE WITH SUPERCELLS...WITH AN EARLY EVENING PEAK
TORNADO THREAT /PERHAPS A COUPLE OF STRONG TORNADOES/ BOOSTED BY A
NOCTURNALLY STRENGTHENING SOUTHERLY LOW LEVEL JET AND ASSOCIATED
LOW-LEVEL HODOGRAPH ENLARGEMENT. ULTIMATELY...ONE OR MORE MCS/S
SHOULD EVOLVE ALONG NOSE OF STRENGTHENING LOW LEVEL JET OVER OK AND
EVENTUALLY INTO THE OZARKS BY LATE EVENING/OVERNIGHT. DAMAGING WIND
POTENTIAL WILL LIKELY INCREASE IN ASSOCIATION WITH MCS DEVELOPMENT
THIS EVENING....ASIDE FROM A SEVERE HAIL AND CONTINUED TORNADO
RISK...BUT ON AN INCREASINGLY ISOLATED BASIS INTO LATE
EVENING/OVERNIGHT.

...UPPER MIDWEST/GREAT LAKES...
MID-LEVEL SHORTWAVE TROUGH/SPEED MAX WILL PIVOT NORTHEASTWARD OVER
THE UPPER MIDWEST/UPPER MS VALLEY DURING THE AFTERNOON...WITH
ASSOCIATED FORCING FOR ASCENT OVERSPREADING A RELATIVELY
MOIST/UNSTABLE BOUNDARY LAYER TO THE SOUTH OF A WARM FRONT EXTENDING
FROM THE EASTERN DAKOTAS/MN SURFACE LOW EASTWARD TO NORTHERN
PORTIONS OF THE GREAT LAKES REGION.

TWO GENERAL SCENARIOS FOR SEVERE TSTM DEVELOPMENT SEEM PROBABLE THIS
AFTERNOON. ONE BEING PARTS OF IA/UPPER MS VALLEY ON THE EASTERN
PERIPHERY OF THE UPPER LOW AND UPPER JET EXIT REGION AS IT COINCIDES
WITH THE SYNOPTIC FRONT. MEANWHILE...FARTHER EAST...PROPAGATION OF
REMNANT OUTFLOW /EVEN SUBTLE REMNANTS INTO AFTERNOON/ ARE A
PLAUSIBLE INFLUENCE FOR RENEWED TSTM DEVELOPMENT INTO A VERY
UNSTABLE AIRMASS ACROSS THE GREAT LAKES REGION. OVERALL...THIS
INCLUDES POTENTIAL FOR SOME SUPERCELLS ASIDE FROM SUSTAINED LINEAR
STRUCTURES...WITH BOUTS OF DAMAGING WINDS/SEVERE HAIL AND A COUPLE
OF TORNADOES ALL POSSIBLE ACROSS THE REGION.

...SOUTHEAST STATES/FL...
THE AIRMASS SHOULD STRONGLY DESTABILIZE THIS AFTERNOON...ESPECIALLY
IN AREAS NEAR AND WEST-SOUTHWEST OF THE APPALACHIANS SPINE...WITH
DIURNALLY INCREASING/INTENSIFYING TSTM DEVELOPMENT FURTHER AIDED BY
A PERSISTENT UPPER LOW OVER THE REGION. BOUTS OF DAMAGING WINDS AND
SOME HAIL WILL BE POSSIBLE AS STORMS GENERALLY DRIFT SOUTHWARD
THROUGH THE AFTERNOON/EARLY EVENING HOURS.

..GUYER/MEAD.. 05/20/2013

000
ACUS01 KWNS 200620
SWODY1
SPC AC 200617

DAY 1 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0117 AM CDT MON MAY 20 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF OK/FAR
SOUTHEAST KS/SOUTHERN MO/NORTHWEST AR/FAR NORTH TX...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE
MIDWEST/GREAT LAKES REGION...

CORRECTED FOR AREAS IN MODERATE RISK HEADLINE

...SYNOPSIS...
YET ANOTHER ACTIVE/RELATIVELY WIDESPREAD SEVERE WEATHER DAY IS
LIKELY ACROSS PORTIONS OF THE SOUTHERN PLAINS TO MIDWEST TODAY AND
TONIGHT. A PROMINENT CENTRAL CONUS UPPER TROUGH WILL CONTINUE A
GENERAL EASTWARD ADVANCEMENT THROUGH TONIGHT...WITH A LEAD/CLOSED
UPPER LOW PIVOTING OVER THE DAKOTAS/UPPER MIDWEST. A SOUTHERN STREAM
SHORTWAVE TROUGH/MODERATELY STRONG POLAR JET WILL EJECT
EAST-NORTHEASTWARD OVER THE SOUTHERN ROCKIES TO THE SOUTHERN
PLAINS/OZARKS...WITH SEVERE TSTMS INCREASINGLY LIKELY BY PEAK
HEATING AND CONTINUING INTO TONIGHT.

MEANWHILE...A LINGERING UPPER LOW OVER THE COASTAL SOUTHEAST STATES
WILL CONTRIBUTE TO ANOTHER DAY OF WIDELY SCATTERED TO SCATTERED
TSTMS OVER THE REGION...SOME OF WHICH MAY AGAIN BE STRONG OR SEVERE.

...SOUTHERN PLAINS/OZARKS/MIDDLE MS VALLEY...
UNDER THE INFLUENCE OF BROAD/MODERATELY STRONG CYCLONIC FLOW
ALOFT...THE AIRMASS IS EXPECTED TO AGAIN BECOME QUITE UNSTABLE
ACROSS MUCH OF THE REGION BY THE AFTERNOON BENEATH AN ELEVATED MIXED
LAYER EXTENDING ACROSS THE SOUTHERN PLAINS INTO PARTS OF THE OZARKS
AND LOWER/MIDDLE MS VALLEY. MIDDLE/UPPER 60S AND SOME LOWER 70S F
SURFACE DEWPOINTS WILL BE QUITE COMMON WITHIN A SPATIALLY BROAD WARM
SECTOR AHEAD OF A COLD FRONT EXTENDING FROM AN EASTERN DAKOTAS/MN
SURFACE LOW SOUTHWESTWARD TO NEAR THE KANSAS CITY AREA/EASTERN KS
AND WESTERN OK...AND AHEAD OF A DRYLINE EXTENDING FROM SOUTHWEST OK
SOUTHWARD INTO WESTERN NORTH TX/WEST-CENTRAL TX.

OUTFLOW REMNANTS FROM OVERNIGHT/EARLY DAY CONVECTION ACROSS THE
OZARKS/MIDDLE MS VALLEY WILL LIKELY BE A FACTOR INTO THIS
AFTERNOON...POSSIBLY AS A RENEWED FOCUS FOR SEVERE TSTM
REDEVELOPMENT...WITH THE MOST AGGRESSIVE HEATING/DESTABILIZATION ON
THE WESTERN FRINGES OF THIS ACTIVITY ACROSS THE SOUTHERN PLAINS AND
PERHAPS LOWER MO VALLEY JUST AHEAD OF THE TRUE SYNOPTIC COLD FRONT.
SEVERE TSTMS CAPABLE OF HAIL/DAMAGING WINDS AND SOME TORNADO THREAT
WILL BE POSSIBLE ALONG THIS FRONTAL ZONE ACROSS EASTERN KS/NORTHERN
MO INTO THE UPPER MS VALLEY...WITH A PERSISTENT/EAST-NORTHEASTWARD
DEVELOPING SEVERE THREAT INTO THE EVENING.

THAT SAID...THE MOST INTENSE/MOST PROBABLE SEVERE STORMS ARE
ANTICIPATED A BIT FARTHER SOUTH-SOUTHWEST ACROSS THE SOUTHERN
PLAINS/OZARKS BY MID/LATE AFTERNOON INTO TONIGHT. THIS INCLUDES A
PORTION OF THE SYNOPTIC FRONT AND/OR OUTFLOW ACROSS FAR SOUTHEAST
KS/SOUTHWEST MO...AREAS ROUGHLY PARALLEL AND NORTHWEST OF THE I-44
CORRIDOR...BUT ESPECIALLY SOUTH-SOUTHWESTWARD INTO MUCH OF THE
MIDDLE PART OF OK /POTENTIALLY INCLUDING OKC METRO/...TO NEAR THE
HEAT-AIDED SURFACE LOW AND SOUTHWARD-EXTENDING SHARPENING DRYLINE
INTO THE WESTERN PART OF NORTH TX/WEST-CENTRAL TX. IN THIS
CORRIDOR...MLCAPE VALUES ARE LIKELY TO EXCEED 2500-3000 J/KG BY
AFTERNOON WITHIN THE WARM SECTOR ACROSS OK AND
WEST-CENTRAL/NORTH-CENTRAL TX...AND PERHAPS INTO PARTS OF SOUTHEAST
KS AND MO. WITH BROAD/MODERATELY STRONG CYCLONIC MID-HIGH LEVEL FLOW
/50+ KT AT 500 MB/ OVER THE REGION...40-50 KT OF EFFECTIVE SHEAR
WILL COINCIDE WITH THE MAJORITY OF THE EFFECTIVE FRONTAL ZONE AND/OR
DRYLINE ACROSS OK/EXTREME NORTH TX INTO SOUTHEAST KS AND THE OZARKS.

THE DEGREE OF SHEAR AND MOISTURE/INSTABILITY WITHIN THE WARM SECTOR
WILL FAVOR SCATTERED TO NUMEROUS SUPERCELL STRUCTURES...AT LEAST
THROUGH MID-EVENING OF THE CONVECTIVE CYCLE. VERY LARGE HAIL AND
TORNADOES ARE POSSIBLE WITH SUPERCELLS...WITH AN EARLY EVENING PEAK
TORNADO THREAT /PERHAPS A COUPLE OF STRONG TORNADOES/ BOOSTED BY A
NOCTURNALLY STRENGTHENING SOUTHERLY LOW LEVEL JET AND ASSOCIATED
LOW-LEVEL HODOGRAPH ENLARGEMENT. ULTIMATELY...ONE OR MORE MCS/S
SHOULD EVOLVE ALONG NOSE OF STRENGTHENING LOW LEVEL JET OVER OK AND
EVENTUALLY INTO THE OZARKS BY LATE EVENING/OVERNIGHT. DAMAGING WIND
POTENTIAL WILL LIKELY INCREASE IN ASSOCIATION WITH MCS DEVELOPMENT
THIS EVENING....ASIDE FROM A SEVERE HAIL AND CONTINUED TORNADO
RISK...BUT ON AN INCREASINGLY ISOLATED BASIS INTO LATE
EVENING/OVERNIGHT.

...UPPER MIDWEST/GREAT LAKES...
MID-LEVEL SHORTWAVE TROUGH/SPEED MAX WILL PIVOT NORTHEASTWARD OVER
THE UPPER MIDWEST/UPPER MS VALLEY DURING THE AFTERNOON...WITH
ASSOCIATED FORCING FOR ASCENT OVERSPREADING A RELATIVELY
MOIST/UNSTABLE BOUNDARY LAYER TO THE SOUTH OF A WARM FRONT EXTENDING
FROM THE EASTERN DAKOTAS/MN SURFACE LOW EASTWARD TO NORTHERN
PORTIONS OF THE GREAT LAKES REGION.

TWO GENERAL SCENARIOS FOR SEVERE TSTM DEVELOPMENT SEEM PROBABLE THIS
AFTERNOON. ONE BEING PARTS OF IA/UPPER MS VALLEY ON THE EASTERN
PERIPHERY OF THE UPPER LOW AND UPPER JET EXIT REGION AS IT COINCIDES
WITH THE SYNOPTIC FRONT. MEANWHILE...FARTHER EAST...PROPAGATION OF
REMNANT OUTFLOW /EVEN SUBTLE REMNANTS INTO AFTERNOON/ ARE A
PLAUSIBLE INFLUENCE FOR RENEWED TSTM DEVELOPMENT INTO A VERY
UNSTABLE AIRMASS ACROSS THE GREAT LAKES REGION. OVERALL...THIS
INCLUDES POTENTIAL FOR SOME SUPERCELLS ASIDE FROM SUSTAINED LINEAR
STRUCTURES...WITH BOUTS OF DAMAGING WINDS/SEVERE HAIL AND A COUPLE
OF TORNADOES ALL POSSIBLE ACROSS THE REGION.

...SOUTHEAST STATES/FL...
THE AIRMASS SHOULD STRONGLY DESTABILIZE THIS AFTERNOON...ESPECIALLY
IN AREAS NEAR AND WEST-SOUTHWEST OF THE APPALACHIANS SPINE...WITH
DIURNALLY INCREASING/INTENSIFYING TSTM DEVELOPMENT FURTHER AIDED BY
A PERSISTENT UPPER LOW OVER THE REGION. BOUTS OF DAMAGING WINDS AND
SOME HAIL WILL BE POSSIBLE AS STORMS GENERALLY DRIFT SOUTHWARD
THROUGH THE AFTERNOON/EARLY EVENING HOURS.

..GUYER/MEAD.. 05/20/2013

000
ACUS01 KWNS 200602
SWODY1
SPC AC 200600

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT MON MAY 20 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF OK/SOUTHEAST
OK/SOUTHERN MO/NORTHWEST AR...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE
MIDWEST/GREAT LAKES REGION...

...SYNOPSIS...
YET ANOTHER ACTIVE/RELATIVELY WIDESPREAD SEVERE WEATHER DAY IS
LIKELY ACROSS PORTIONS OF THE SOUTHERN PLAINS TO MIDWEST TODAY AND
TONIGHT. A PROMINENT CENTRAL CONUS UPPER TROUGH WILL CONTINUE A
GENERAL EASTWARD ADVANCEMENT THROUGH TONIGHT...WITH A LEAD/CLOSED
UPPER LOW PIVOTING OVER THE DAKOTAS/UPPER MIDWEST. A SOUTHERN STREAM
SHORTWAVE TROUGH/MODERATELY STRONG POLAR JET WILL EJECT
EAST-NORTHEASTWARD OVER THE SOUTHERN ROCKIES TO THE SOUTHERN
PLAINS/OZARKS...WITH SEVERE TSTMS INCREASINGLY LIKELY BY PEAK
HEATING AND CONTINUING INTO TONIGHT.

MEANWHILE...A LINGERING UPPER LOW OVER THE COASTAL SOUTHEAST STATES
WILL CONTRIBUTE TO ANOTHER DAY OF WIDELY SCATTERED TO SCATTERED
TSTMS OVER THE REGION...SOME OF WHICH MAY AGAIN BE STRONG OR SEVERE.


...SOUTHERN PLAINS/OZARKS/MIDDLE MS VALLEY...
UNDER THE INFLUENCE OF BROAD/MODERATELY STRONG CYCLONIC FLOW
ALOFT...THE AIRMASS IS EXPECTED TO AGAIN BECOME QUITE UNSTABLE
ACROSS MUCH OF THE REGION BY THE AFTERNOON BENEATH AN ELEVATED MIXED
LAYER EXTENDING ACROSS THE SOUTHERN PLAINS INTO PARTS OF THE OZARKS
AND LOWER/MIDDLE MS VALLEY. MIDDLE/UPPER 60S AND SOME LOWER 70S F
SURFACE DEWPOINTS WILL BE QUITE COMMON WITHIN A SPATIALLY BROAD WARM
SECTOR AHEAD OF A COLD FRONT EXTENDING FROM AN EASTERN DAKOTAS/MN
SURFACE LOW SOUTHWESTWARD TO NEAR THE KANSAS CITY AREA/EASTERN KS
AND WESTERN OK...AND AHEAD OF A DRYLINE EXTENDING FROM SOUTHWEST OK
SOUTHWARD INTO WESTERN NORTH TX/WEST-CENTRAL TX.

OUTFLOW REMNANTS FROM OVERNIGHT/EARLY DAY CONVECTION ACROSS THE
OZARKS/MIDDLE MS VALLEY WILL LIKELY BE A FACTOR INTO THIS
AFTERNOON...POSSIBLY AS A RENEWED FOCUS FOR SEVERE TSTM
REDEVELOPMENT...WITH THE MOST AGGRESSIVE HEATING/DESTABILIZATION ON
THE WESTERN FRINGES OF THIS ACTIVITY ACROSS THE SOUTHERN PLAINS AND
PERHAPS LOWER MO VALLEY JUST AHEAD OF THE TRUE SYNOPTIC COLD FRONT.
SEVERE TSTMS CAPABLE OF HAIL/DAMAGING WINDS AND SOME TORNADO THREAT
WILL BE POSSIBLE ALONG THIS FRONTAL ZONE ACROSS EASTERN KS/NORTHERN
MO INTO THE UPPER MS VALLEY...WITH A PERSISTENT/EAST-NORTHEASTWARD
DEVELOPING SEVERE THREAT INTO THE EVENING.

THAT SAID...THE MOST INTENSE/MOST PROBABLE SEVERE STORMS ARE
ANTICIPATED A BIT FARTHER SOUTH-SOUTHWEST ACROSS THE SOUTHERN
PLAINS/OZARKS BY MID/LATE AFTERNOON INTO TONIGHT. THIS INCLUDES A
PORTION OF THE SYNOPTIC FRONT AND/OR OUTFLOW ACROSS FAR SOUTHEAST
KS/SOUTHWEST MO...AREAS ROUGHLY PARALLEL AND NORTHWEST OF THE I-44
CORRIDOR...BUT ESPECIALLY SOUTH-SOUTHWESTWARD INTO MUCH OF THE
MIDDLE PART OF OK /POTENTIALLY INCLUDING OKC METRO/...TO NEAR THE
HEAT-AIDED SURFACE LOW AND SOUTHWARD-EXTENDING SHARPENING DRYLINE
INTO THE WESTERN PART OF NORTH TX/WEST-CENTRAL TX. IN THIS
CORRIDOR...MLCAPE VALUES ARE LIKELY TO EXCEED 2500-3000 J/KG BY
AFTERNOON WITHIN THE WARM SECTOR ACROSS OK AND
WEST-CENTRAL/NORTH-CENTRAL TX...AND PERHAPS INTO PARTS OF SOUTHEAST
KS AND MO. WITH BROAD/MODERATELY STRONG CYCLONIC MID-HIGH LEVEL FLOW
/50+ KT AT 500 MB/ OVER THE REGION...40-50 KT OF EFFECTIVE SHEAR
WILL COINCIDE WITH THE MAJORITY OF THE EFFECTIVE FRONTAL ZONE AND/OR
DRYLINE ACROSS OK/EXTREME NORTH TX INTO SOUTHEAST KS AND THE OZARKS.


THE DEGREE OF SHEAR AND MOISTURE/INSTABILITY WITHIN THE WARM SECTOR
WILL FAVOR SCATTERED TO NUMEROUS SUPERCELL STRUCTURES...AT LEAST
THROUGH MID-EVENING OF THE CONVECTIVE CYCLE. VERY LARGE HAIL AND
TORNADOES ARE POSSIBLE WITH SUPERCELLS...WITH AN EARLY EVENING PEAK
TORNADO THREAT /PERHAPS A COUPLE OF STRONG TORNADOES/ BOOSTED BY A
NOCTURNALLY STRENGTHENING SOUTHERLY LOW LEVEL JET AND ASSOCIATED
LOW-LEVEL HODOGRAPH ENLARGEMENT. ULTIMATELY...ONE OR MORE MCS/S
SHOULD EVOLVE ALONG NOSE OF STRENGTHENING LOW LEVEL JET OVER OK AND
EVENTUALLY INTO THE OZARKS BY LATE EVENING/OVERNIGHT. DAMAGING WIND
POTENTIAL WILL LIKELY INCREASE IN ASSOCIATION WITH MCS DEVELOPMENT
THIS EVENING....ASIDE FROM A SEVERE HAIL AND CONTINUED TORNADO
RISK...BUT ON AN INCREASINGLY ISOLATED BASIS INTO LATE
EVENING/OVERNIGHT.

...UPPER MIDWEST/GREAT LAKES...
MID-LEVEL SHORTWAVE TROUGH/SPEED MAX WILL PIVOT NORTHEASTWARD OVER
THE UPPER MIDWEST/UPPER MS VALLEY DURING THE AFTERNOON...WITH
ASSOCIATED FORCING FOR ASCENT OVERSPREADING A RELATIVELY
MOIST/UNSTABLE BOUNDARY LAYER TO THE SOUTH OF A WARM FRONT EXTENDING
FROM THE EASTERN DAKOTAS/MN SURFACE LOW EASTWARD TO NORTHERN
PORTIONS OF THE GREAT LAKES REGION.

TWO GENERAL SCENARIOS FOR SEVERE TSTM DEVELOPMENT SEEM PROBABLE THIS
AFTERNOON. ONE BEING PARTS OF IA/UPPER MS VALLEY ON THE EASTERN
PERIPHERY OF THE UPPER LOW AND UPPER JET EXIT REGION AS IT COINCIDES
WITH THE SYNOPTIC FRONT. MEANWHILE...FARTHER EAST...PROPAGATION OF
REMNANT OUTFLOW /EVEN SUBTLE REMNANTS INTO AFTERNOON/ ARE A
PLAUSIBLE INFLUENCE FOR RENEWED TSTM DEVELOPMENT INTO A VERY
UNSTABLE AIRMASS ACROSS THE GREAT LAKES REGION. OVERALL...THIS
INCLUDES POTENTIAL FOR SOME SUPERCELLS ASIDE FROM SUSTAINED LINEAR
STRUCTURES...WITH BOUTS OF DAMAGING WINDS/SEVERE HAIL AND A COUPLE
OF TORNADOES ALL POSSIBLE ACROSS THE REGION.

...SOUTHEAST STATES/FL...
THE AIRMASS SHOULD STRONGLY DESTABILIZE THIS AFTERNOON...ESPECIALLY
IN AREAS NEAR AND WEST-SOUTHWEST OF THE APPALACHIANS...WITH
DIURNALLY INCREASING/INTENSIFYING TSTM DEVELOPMENT FURTHER AIDED BY
A PERSISTENT UPPER LOW OVER THE REGION. BOUTS OF DAMAGING WINDS AND
SOME HAIL WILL BE POSSIBLE AS STORMS GENERALLY DRIFT SOUTHWARD
THROUGH THE AFTERNOON/EARLY EVENING HOURS.

..GUYER/MEAD.. 05/20/2013

000
ACUS01 KWNS 200602
SWODY1
SPC AC 200600

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT MON MAY 20 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF OK/SOUTHEAST
OK/SOUTHERN MO/NORTHWEST AR...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE
MIDWEST/GREAT LAKES REGION...

...SYNOPSIS...
YET ANOTHER ACTIVE/RELATIVELY WIDESPREAD SEVERE WEATHER DAY IS
LIKELY ACROSS PORTIONS OF THE SOUTHERN PLAINS TO MIDWEST TODAY AND
TONIGHT. A PROMINENT CENTRAL CONUS UPPER TROUGH WILL CONTINUE A
GENERAL EASTWARD ADVANCEMENT THROUGH TONIGHT...WITH A LEAD/CLOSED
UPPER LOW PIVOTING OVER THE DAKOTAS/UPPER MIDWEST. A SOUTHERN STREAM
SHORTWAVE TROUGH/MODERATELY STRONG POLAR JET WILL EJECT
EAST-NORTHEASTWARD OVER THE SOUTHERN ROCKIES TO THE SOUTHERN
PLAINS/OZARKS...WITH SEVERE TSTMS INCREASINGLY LIKELY BY PEAK
HEATING AND CONTINUING INTO TONIGHT.

MEANWHILE...A LINGERING UPPER LOW OVER THE COASTAL SOUTHEAST STATES
WILL CONTRIBUTE TO ANOTHER DAY OF WIDELY SCATTERED TO SCATTERED
TSTMS OVER THE REGION...SOME OF WHICH MAY AGAIN BE STRONG OR SEVERE.


...SOUTHERN PLAINS/OZARKS/MIDDLE MS VALLEY...
UNDER THE INFLUENCE OF BROAD/MODERATELY STRONG CYCLONIC FLOW
ALOFT...THE AIRMASS IS EXPECTED TO AGAIN BECOME QUITE UNSTABLE
ACROSS MUCH OF THE REGION BY THE AFTERNOON BENEATH AN ELEVATED MIXED
LAYER EXTENDING ACROSS THE SOUTHERN PLAINS INTO PARTS OF THE OZARKS
AND LOWER/MIDDLE MS VALLEY. MIDDLE/UPPER 60S AND SOME LOWER 70S F
SURFACE DEWPOINTS WILL BE QUITE COMMON WITHIN A SPATIALLY BROAD WARM
SECTOR AHEAD OF A COLD FRONT EXTENDING FROM AN EASTERN DAKOTAS/MN
SURFACE LOW SOUTHWESTWARD TO NEAR THE KANSAS CITY AREA/EASTERN KS
AND WESTERN OK...AND AHEAD OF A DRYLINE EXTENDING FROM SOUTHWEST OK
SOUTHWARD INTO WESTERN NORTH TX/WEST-CENTRAL TX.

OUTFLOW REMNANTS FROM OVERNIGHT/EARLY DAY CONVECTION ACROSS THE
OZARKS/MIDDLE MS VALLEY WILL LIKELY BE A FACTOR INTO THIS
AFTERNOON...POSSIBLY AS A RENEWED FOCUS FOR SEVERE TSTM
REDEVELOPMENT...WITH THE MOST AGGRESSIVE HEATING/DESTABILIZATION ON
THE WESTERN FRINGES OF THIS ACTIVITY ACROSS THE SOUTHERN PLAINS AND
PERHAPS LOWER MO VALLEY JUST AHEAD OF THE TRUE SYNOPTIC COLD FRONT.
SEVERE TSTMS CAPABLE OF HAIL/DAMAGING WINDS AND SOME TORNADO THREAT
WILL BE POSSIBLE ALONG THIS FRONTAL ZONE ACROSS EASTERN KS/NORTHERN
MO INTO THE UPPER MS VALLEY...WITH A PERSISTENT/EAST-NORTHEASTWARD
DEVELOPING SEVERE THREAT INTO THE EVENING.

THAT SAID...THE MOST INTENSE/MOST PROBABLE SEVERE STORMS ARE
ANTICIPATED A BIT FARTHER SOUTH-SOUTHWEST ACROSS THE SOUTHERN
PLAINS/OZARKS BY MID/LATE AFTERNOON INTO TONIGHT. THIS INCLUDES A
PORTION OF THE SYNOPTIC FRONT AND/OR OUTFLOW ACROSS FAR SOUTHEAST
KS/SOUTHWEST MO...AREAS ROUGHLY PARALLEL AND NORTHWEST OF THE I-44
CORRIDOR...BUT ESPECIALLY SOUTH-SOUTHWESTWARD INTO MUCH OF THE
MIDDLE PART OF OK /POTENTIALLY INCLUDING OKC METRO/...TO NEAR THE
HEAT-AIDED SURFACE LOW AND SOUTHWARD-EXTENDING SHARPENING DRYLINE
INTO THE WESTERN PART OF NORTH TX/WEST-CENTRAL TX. IN THIS
CORRIDOR...MLCAPE VALUES ARE LIKELY TO EXCEED 2500-3000 J/KG BY
AFTERNOON WITHIN THE WARM SECTOR ACROSS OK AND
WEST-CENTRAL/NORTH-CENTRAL TX...AND PERHAPS INTO PARTS OF SOUTHEAST
KS AND MO. WITH BROAD/MODERATELY STRONG CYCLONIC MID-HIGH LEVEL FLOW
/50+ KT AT 500 MB/ OVER THE REGION...40-50 KT OF EFFECTIVE SHEAR
WILL COINCIDE WITH THE MAJORITY OF THE EFFECTIVE FRONTAL ZONE AND/OR
DRYLINE ACROSS OK/EXTREME NORTH TX INTO SOUTHEAST KS AND THE OZARKS.


THE DEGREE OF SHEAR AND MOISTURE/INSTABILITY WITHIN THE WARM SECTOR
WILL FAVOR SCATTERED TO NUMEROUS SUPERCELL STRUCTURES...AT LEAST
THROUGH MID-EVENING OF THE CONVECTIVE CYCLE. VERY LARGE HAIL AND
TORNADOES ARE POSSIBLE WITH SUPERCELLS...WITH AN EARLY EVENING PEAK
TORNADO THREAT /PERHAPS A COUPLE OF STRONG TORNADOES/ BOOSTED BY A
NOCTURNALLY STRENGTHENING SOUTHERLY LOW LEVEL JET AND ASSOCIATED
LOW-LEVEL HODOGRAPH ENLARGEMENT. ULTIMATELY...ONE OR MORE MCS/S
SHOULD EVOLVE ALONG NOSE OF STRENGTHENING LOW LEVEL JET OVER OK AND
EVENTUALLY INTO THE OZARKS BY LATE EVENING/OVERNIGHT. DAMAGING WIND
POTENTIAL WILL LIKELY INCREASE IN ASSOCIATION WITH MCS DEVELOPMENT
THIS EVENING....ASIDE FROM A SEVERE HAIL AND CONTINUED TORNADO
RISK...BUT ON AN INCREASINGLY ISOLATED BASIS INTO LATE
EVENING/OVERNIGHT.

...UPPER MIDWEST/GREAT LAKES...
MID-LEVEL SHORTWAVE TROUGH/SPEED MAX WILL PIVOT NORTHEASTWARD OVER
THE UPPER MIDWEST/UPPER MS VALLEY DURING THE AFTERNOON...WITH
ASSOCIATED FORCING FOR ASCENT OVERSPREADING A RELATIVELY
MOIST/UNSTABLE BOUNDARY LAYER TO THE SOUTH OF A WARM FRONT EXTENDING
FROM THE EASTERN DAKOTAS/MN SURFACE LOW EASTWARD TO NORTHERN
PORTIONS OF THE GREAT LAKES REGION.

TWO GENERAL SCENARIOS FOR SEVERE TSTM DEVELOPMENT SEEM PROBABLE THIS
AFTERNOON. ONE BEING PARTS OF IA/UPPER MS VALLEY ON THE EASTERN
PERIPHERY OF THE UPPER LOW AND UPPER JET EXIT REGION AS IT COINCIDES
WITH THE SYNOPTIC FRONT. MEANWHILE...FARTHER EAST...PROPAGATION OF
REMNANT OUTFLOW /EVEN SUBTLE REMNANTS INTO AFTERNOON/ ARE A
PLAUSIBLE INFLUENCE FOR RENEWED TSTM DEVELOPMENT INTO A VERY
UNSTABLE AIRMASS ACROSS THE GREAT LAKES REGION. OVERALL...THIS
INCLUDES POTENTIAL FOR SOME SUPERCELLS ASIDE FROM SUSTAINED LINEAR
STRUCTURES...WITH BOUTS OF DAMAGING WINDS/SEVERE HAIL AND A COUPLE
OF TORNADOES ALL POSSIBLE ACROSS THE REGION.

...SOUTHEAST STATES/FL...
THE AIRMASS SHOULD STRONGLY DESTABILIZE THIS AFTERNOON...ESPECIALLY
IN AREAS NEAR AND WEST-SOUTHWEST OF THE APPALACHIANS...WITH
DIURNALLY INCREASING/INTENSIFYING TSTM DEVELOPMENT FURTHER AIDED BY
A PERSISTENT UPPER LOW OVER THE REGION. BOUTS OF DAMAGING WINDS AND
SOME HAIL WILL BE POSSIBLE AS STORMS GENERALLY DRIFT SOUTHWARD
THROUGH THE AFTERNOON/EARLY EVENING HOURS.

..GUYER/MEAD.. 05/20/2013

000
ACUS02 KWNS 200600
SWODY2
SPC AC 200559

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT MON MAY 20 2013

VALID 211200Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE GREAT LAKES REGION
SWWD TO THE RIO GRANDE VALLEY OF S TX...

...SYNOPSIS...
AN UPPER LOW PROGGED TO RESIDE OVER THE ERN SD VICINITY AT THE START
OF THE PERIOD IS FORECAST TO WEAKEN WITH TIME...AS IT -- AND THE
ASSOCIATED TROUGH EXTENDING SWD INTO THE SRN PLAINS -- SHIFTS EWD
THROUGH THE PERIOD.  EWD PROGRESS OF THE SYSTEM WILL BE AIDED BY AN
EMBEDDED SHORT-WAVE TROUGH MOVING EWD ACROSS THE SRN PLAINS.
ELSEWHERE...AN UPPER LOW IS FORECAST TO DIG SEWD INTO THE PAC
NW...AND A VERY WEAK LOW SHOULD LINGER ACROSS FL.

AT THE SURFACE...A LOW INITIALLY INVOF SWRN MN IS FORECAST TO MOVE
SLOWLY EWD IN CONJUNCTION WITH THE UPPER SYSTEM...REACHING THE WRN
UPPER GREAT LAKES LATE.  THE TRAILING COLD FRONT DRAPED INITIALLY
FROM MN/IA SWWD INTO CENTRAL TX WILL MOVE SLOWLY EWD WITH
TIME...WEAKENING AS IT PROGRESSES ACROSS THE UPPER MIDWEST/MO
REGION.  THE SRN FRINGE OF THE FRONT SHOULD LINGER ACROSS TX THROUGH
THE AFTERNOON...BEFORE WASHING OUT COMPLETELY OVERNIGHT.

...THE GREAT LAKES REGION SWWD ACROSS CENTRAL TX...
SCATTERED/ONGOING CONVECTION IS FORECAST ACROSS A LARGE PORTION OF
THE RISK AREA TO START THE PERIOD...CONTINUING INTO THE AFTERNOON
HOURS.  THREAT FOR HAIL/DAMAGING WINDS MAY EXIST LOCALLY WITH THE
ONGOING STORMS...BUT THE GREATER EFFECT OF THIS CONVECTION WILL
LIKELY BE TO HINDER HEATING/DESTABILIZATION ACROSS MUCH OF THE
OUTLOOK AREA -- PARTICULARLY FROM PARTS OF AR NEWD.  WHILE SOME
INTENSIFICATION OF THE CONVECTION WILL OCCUR ACROSS THIS PART OF THE
AREA THROUGH THE DIURNAL PEAK HEATING PERIOD...THE LACK OF GREATER
DESTABILIZATION SHOULD TEMPER THE OVERALL THREAT ACROSS MUCH OF THIS
AREA.

FARTHER SW ACROSS THE ARKLATEX REGION INTO CENTRAL TX/THE HILL
COUNTRY AREA...STRONG DESTABILIZATION IS EXPECTED.  WITH 40 TO 50 KT
WSWLY MID-LEVEL FLOW SPREADING ACROSS TX AS THE MID-LEVEL SHORT-WAVE
TROUGH SHIFTS EWD...STRENGTHENING SHEAR WILL ALLOW DEVELOPING STORMS
ALONG THE WEAKENING FRONT TO RAPIDLY STRENGTHEN/ACQUIRE ROTATION.
WITH LOW-LEVEL FLOW FORECAST TO REMAIN SOMEWHAT WEAK...ONLY ISOLATED
TORNADO POTENTIAL IS EXPECTED -- MAINLY DURING THE EVENING AS SOME
INCREASE IN LOW-LEVEL FLOW OCCURS.  INSTEAD...THE MAIN SEVERE THREAT
WILL LIKELY BE VERY LARGE HAIL...WHILE WIND THREAT INCREASES WITH
TIME AS STORMS LIKELY CONGEAL DURING THE EVENING HOURS.

SOME THREAT MAY EXTEND AS FAR NWWD AS WI -- JUST AHEAD OF THE UPPER
LOW WHERE LOW-TOPPED STORMS AND ISOLATED SEVERE THREAT MAY
EVOLVE...AND AS FAR NE AS THE LOWER GREAT LAKES REGION...WHERE A
BAND OF LATE AFTERNOON STORMS AND ASSOCIATED THREAT FOR ISOLATED
WIND DAMAGE COULD OCCUR.

..GOSS.. 05/20/2013

000
ACUS02 KWNS 200600
SWODY2
SPC AC 200559

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1259 AM CDT MON MAY 20 2013

VALID 211200Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE GREAT LAKES REGION
SWWD TO THE RIO GRANDE VALLEY OF S TX...

...SYNOPSIS...
AN UPPER LOW PROGGED TO RESIDE OVER THE ERN SD VICINITY AT THE START
OF THE PERIOD IS FORECAST TO WEAKEN WITH TIME...AS IT -- AND THE
ASSOCIATED TROUGH EXTENDING SWD INTO THE SRN PLAINS -- SHIFTS EWD
THROUGH THE PERIOD.  EWD PROGRESS OF THE SYSTEM WILL BE AIDED BY AN
EMBEDDED SHORT-WAVE TROUGH MOVING EWD ACROSS THE SRN PLAINS.
ELSEWHERE...AN UPPER LOW IS FORECAST TO DIG SEWD INTO THE PAC
NW...AND A VERY WEAK LOW SHOULD LINGER ACROSS FL.

AT THE SURFACE...A LOW INITIALLY INVOF SWRN MN IS FORECAST TO MOVE
SLOWLY EWD IN CONJUNCTION WITH THE UPPER SYSTEM...REACHING THE WRN
UPPER GREAT LAKES LATE.  THE TRAILING COLD FRONT DRAPED INITIALLY
FROM MN/IA SWWD INTO CENTRAL TX WILL MOVE SLOWLY EWD WITH
TIME...WEAKENING AS IT PROGRESSES ACROSS THE UPPER MIDWEST/MO
REGION.  THE SRN FRINGE OF THE FRONT SHOULD LINGER ACROSS TX THROUGH
THE AFTERNOON...BEFORE WASHING OUT COMPLETELY OVERNIGHT.

...THE GREAT LAKES REGION SWWD ACROSS CENTRAL TX...
SCATTERED/ONGOING CONVECTION IS FORECAST ACROSS A LARGE PORTION OF
THE RISK AREA TO START THE PERIOD...CONTINUING INTO THE AFTERNOON
HOURS.  THREAT FOR HAIL/DAMAGING WINDS MAY EXIST LOCALLY WITH THE
ONGOING STORMS...BUT THE GREATER EFFECT OF THIS CONVECTION WILL
LIKELY BE TO HINDER HEATING/DESTABILIZATION ACROSS MUCH OF THE
OUTLOOK AREA -- PARTICULARLY FROM PARTS OF AR NEWD.  WHILE SOME
INTENSIFICATION OF THE CONVECTION WILL OCCUR ACROSS THIS PART OF THE
AREA THROUGH THE DIURNAL PEAK HEATING PERIOD...THE LACK OF GREATER
DESTABILIZATION SHOULD TEMPER THE OVERALL THREAT ACROSS MUCH OF THIS
AREA.

FARTHER SW ACROSS THE ARKLATEX REGION INTO CENTRAL TX/THE HILL
COUNTRY AREA...STRONG DESTABILIZATION IS EXPECTED.  WITH 40 TO 50 KT
WSWLY MID-LEVEL FLOW SPREADING ACROSS TX AS THE MID-LEVEL SHORT-WAVE
TROUGH SHIFTS EWD...STRENGTHENING SHEAR WILL ALLOW DEVELOPING STORMS
ALONG THE WEAKENING FRONT TO RAPIDLY STRENGTHEN/ACQUIRE ROTATION.
WITH LOW-LEVEL FLOW FORECAST TO REMAIN SOMEWHAT WEAK...ONLY ISOLATED
TORNADO POTENTIAL IS EXPECTED -- MAINLY DURING THE EVENING AS SOME
INCREASE IN LOW-LEVEL FLOW OCCURS.  INSTEAD...THE MAIN SEVERE THREAT
WILL LIKELY BE VERY LARGE HAIL...WHILE WIND THREAT INCREASES WITH
TIME AS STORMS LIKELY CONGEAL DURING THE EVENING HOURS.

SOME THREAT MAY EXTEND AS FAR NWWD AS WI -- JUST AHEAD OF THE UPPER
LOW WHERE LOW-TOPPED STORMS AND ISOLATED SEVERE THREAT MAY
EVOLVE...AND AS FAR NE AS THE LOWER GREAT LAKES REGION...WHERE A
BAND OF LATE AFTERNOON STORMS AND ASSOCIATED THREAT FOR ISOLATED
WIND DAMAGE COULD OCCUR.

..GOSS.. 05/20/2013

000
ACUS11 KWNS 200450
SWOMCD
SPC MCD 200449
MOZ000-OKZ000-KSZ000-200545-

MESOSCALE DISCUSSION 0721
NWS STORM PREDICTION CENTER NORMAN OK
1149 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SWRN AND CNTRL PORTIONS OF MO

CONCERNING...TORNADO WATCH 186...

VALID 200449Z - 200545Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 186 CONTINUES.

SUMMARY...A SEVERE STORM THREAT WILL PROBABLY PERSIST BEYOND THE
0600Z WATCH EXPIRATION TIME.  A LOCAL EXTENSION-IN-TIME OR A NEW
WATCH ISSUANCE MAY BE REQUIRED.

DISCUSSION...RADAR MOSAIC SHOWS A STRONG TO SEVERE SQUALL LINE OVER
FAR SERN KS.  THIS ACTIVITY WILL LIKELY MOVE INTO SWRN MO AND
MAINTAIN SOME SEVERE THREAT MAINLY IN THE FORM OF DMGG WINDS.  A
CONDITIONAL TORNADO THREAT WILL SEEMINGLY EXIST PREDICATED ON EITHER
A STORM DEVELOPING INTO A SUPERCELL AHEAD OF THIS COMPLEX OF STORMS
/LOW PROBABILITY/ OR ANY MESOVORTICES THAT MAY DEVELOP AS THE
CLUSTER MOVES EWD.  GIVEN A STRONG 60 KT LLJ SAMPLED BY THE SGF
VWP...STRONG MASS FLUX INTO THIS REGION WILL ACT TO SUSTAIN THE
ONGOING ACTIVITY BEYOND THE 06Z WATCH EXPIRATION TIME.

..SMITH.. 05/20/2013

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

ATTN...WFO...LSX...SGF...TSA...

LAT...LON   36549335 36569453 37119500 37779455 38039359 38229227
            37809153 36899181 36549335

000
ACUS11 KWNS 200450
SWOMCD
SPC MCD 200449
MOZ000-OKZ000-KSZ000-200545-

MESOSCALE DISCUSSION 0721
NWS STORM PREDICTION CENTER NORMAN OK
1149 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SWRN AND CNTRL PORTIONS OF MO

CONCERNING...TORNADO WATCH 186...

VALID 200449Z - 200545Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 186 CONTINUES.

SUMMARY...A SEVERE STORM THREAT WILL PROBABLY PERSIST BEYOND THE
0600Z WATCH EXPIRATION TIME.  A LOCAL EXTENSION-IN-TIME OR A NEW
WATCH ISSUANCE MAY BE REQUIRED.

DISCUSSION...RADAR MOSAIC SHOWS A STRONG TO SEVERE SQUALL LINE OVER
FAR SERN KS.  THIS ACTIVITY WILL LIKELY MOVE INTO SWRN MO AND
MAINTAIN SOME SEVERE THREAT MAINLY IN THE FORM OF DMGG WINDS.  A
CONDITIONAL TORNADO THREAT WILL SEEMINGLY EXIST PREDICATED ON EITHER
A STORM DEVELOPING INTO A SUPERCELL AHEAD OF THIS COMPLEX OF STORMS
/LOW PROBABILITY/ OR ANY MESOVORTICES THAT MAY DEVELOP AS THE
CLUSTER MOVES EWD.  GIVEN A STRONG 60 KT LLJ SAMPLED BY THE SGF
VWP...STRONG MASS FLUX INTO THIS REGION WILL ACT TO SUSTAIN THE
ONGOING ACTIVITY BEYOND THE 06Z WATCH EXPIRATION TIME.

..SMITH.. 05/20/2013

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

ATTN...WFO...LSX...SGF...TSA...

LAT...LON   36549335 36569453 37119500 37779455 38039359 38229227
            37809153 36899181 36549335

000
ACUS11 KWNS 200450
SWOMCD
SPC MCD 200449
MOZ000-OKZ000-KSZ000-200545-

MESOSCALE DISCUSSION 0721
NWS STORM PREDICTION CENTER NORMAN OK
1149 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SWRN AND CNTRL PORTIONS OF MO

CONCERNING...TORNADO WATCH 186...

VALID 200449Z - 200545Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 186 CONTINUES.

SUMMARY...A SEVERE STORM THREAT WILL PROBABLY PERSIST BEYOND THE
0600Z WATCH EXPIRATION TIME.  A LOCAL EXTENSION-IN-TIME OR A NEW
WATCH ISSUANCE MAY BE REQUIRED.

DISCUSSION...RADAR MOSAIC SHOWS A STRONG TO SEVERE SQUALL LINE OVER
FAR SERN KS.  THIS ACTIVITY WILL LIKELY MOVE INTO SWRN MO AND
MAINTAIN SOME SEVERE THREAT MAINLY IN THE FORM OF DMGG WINDS.  A
CONDITIONAL TORNADO THREAT WILL SEEMINGLY EXIST PREDICATED ON EITHER
A STORM DEVELOPING INTO A SUPERCELL AHEAD OF THIS COMPLEX OF STORMS
/LOW PROBABILITY/ OR ANY MESOVORTICES THAT MAY DEVELOP AS THE
CLUSTER MOVES EWD.  GIVEN A STRONG 60 KT LLJ SAMPLED BY THE SGF
VWP...STRONG MASS FLUX INTO THIS REGION WILL ACT TO SUSTAIN THE
ONGOING ACTIVITY BEYOND THE 06Z WATCH EXPIRATION TIME.

..SMITH.. 05/20/2013

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

ATTN...WFO...LSX...SGF...TSA...

LAT...LON   36549335 36569453 37119500 37779455 38039359 38229227
            37809153 36899181 36549335

000
ACUS11 KWNS 200359
SWOMCD
SPC MCD 200358
WIZ000-ILZ000-IAZ000-MNZ000-MOZ000-200500-

MESOSCALE DISCUSSION 0720
NWS STORM PREDICTION CENTER NORMAN OK
1058 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-SRN WI / ERN IA / NRN AND W-CNTRL IL

CONCERNING...TORNADO WATCH 185...187...

VALID 200358Z - 200500Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 185...187...CONTINUES.

SUMMARY...A LARGELY ISOLD DMGG WIND THREAT WILL CEASE CONCURRENT
WITH PASSAGE OF THE SQUALL LINE FROM WEST TO EAST.

DISCUSSION...AN EXTENSIVE NORTH TO SOUTH SQUALL LINE WITH SEVERAL
BOWING INFLECTIONS --LIKELY SIGNALING ENHANCED POTENTIAL FOR ISOLD
WIND DAMAGE-- WILL CONTINUE EWD OVER THE MID-UPPER MS RIVER VALLEY
OVER THE NEXT FEW HOURS.  ALTHOUGH SOME BOUNDARY LAYER STABILIZATION
HAS OCCURRED DUE TO NOCTURNAL COOLING...THE STEEP LAPSE RATE
ENVIRONMENT SAMPLED BY THE 00Z DVN RAOB WOULD AT LEAST SUPPORT THE
POSSIBILITY FOR DMGG WIND GUSTS.  ANY LIMITED TORNADO THREAT WILL
LIKELY CONTINUE TO DIMINISH BUT REMAIN NON-ZERO GIVEN THE STRONG LOW
LEVEL WIND PROFILE.  COUNTIES CAN BE CLEARED FROM TORNADO WATCH 187
FROM WEST TO EAST IN ASSOCIATION WITH SQUALL LINE PASSAGE.

..SMITH.. 05/20/2013

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

ATTN...WFO...GRB...LOT...ILX...MKX...LSX...DVN...ARX...MPX...

LAT...LON   40239156 42109186 44379137 45349026 43558850 41738838
            40148980 40239156

000
ACUS11 KWNS 200359
SWOMCD
SPC MCD 200358
WIZ000-ILZ000-IAZ000-MNZ000-MOZ000-200500-

MESOSCALE DISCUSSION 0720
NWS STORM PREDICTION CENTER NORMAN OK
1058 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-SRN WI / ERN IA / NRN AND W-CNTRL IL

CONCERNING...TORNADO WATCH 185...187...

VALID 200358Z - 200500Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 185...187...CONTINUES.

SUMMARY...A LARGELY ISOLD DMGG WIND THREAT WILL CEASE CONCURRENT
WITH PASSAGE OF THE SQUALL LINE FROM WEST TO EAST.

DISCUSSION...AN EXTENSIVE NORTH TO SOUTH SQUALL LINE WITH SEVERAL
BOWING INFLECTIONS --LIKELY SIGNALING ENHANCED POTENTIAL FOR ISOLD
WIND DAMAGE-- WILL CONTINUE EWD OVER THE MID-UPPER MS RIVER VALLEY
OVER THE NEXT FEW HOURS.  ALTHOUGH SOME BOUNDARY LAYER STABILIZATION
HAS OCCURRED DUE TO NOCTURNAL COOLING...THE STEEP LAPSE RATE
ENVIRONMENT SAMPLED BY THE 00Z DVN RAOB WOULD AT LEAST SUPPORT THE
POSSIBILITY FOR DMGG WIND GUSTS.  ANY LIMITED TORNADO THREAT WILL
LIKELY CONTINUE TO DIMINISH BUT REMAIN NON-ZERO GIVEN THE STRONG LOW
LEVEL WIND PROFILE.  COUNTIES CAN BE CLEARED FROM TORNADO WATCH 187
FROM WEST TO EAST IN ASSOCIATION WITH SQUALL LINE PASSAGE.

..SMITH.. 05/20/2013

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

ATTN...WFO...GRB...LOT...ILX...MKX...LSX...DVN...ARX...MPX...

LAT...LON   40239156 42109186 44379137 45349026 43558850 41738838
            40148980 40239156

000
ACUS11 KWNS 200359
SWOMCD
SPC MCD 200358
WIZ000-ILZ000-IAZ000-MNZ000-MOZ000-200500-

MESOSCALE DISCUSSION 0720
NWS STORM PREDICTION CENTER NORMAN OK
1058 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-SRN WI / ERN IA / NRN AND W-CNTRL IL

CONCERNING...TORNADO WATCH 185...187...

VALID 200358Z - 200500Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 185...187...CONTINUES.

SUMMARY...A LARGELY ISOLD DMGG WIND THREAT WILL CEASE CONCURRENT
WITH PASSAGE OF THE SQUALL LINE FROM WEST TO EAST.

DISCUSSION...AN EXTENSIVE NORTH TO SOUTH SQUALL LINE WITH SEVERAL
BOWING INFLECTIONS --LIKELY SIGNALING ENHANCED POTENTIAL FOR ISOLD
WIND DAMAGE-- WILL CONTINUE EWD OVER THE MID-UPPER MS RIVER VALLEY
OVER THE NEXT FEW HOURS.  ALTHOUGH SOME BOUNDARY LAYER STABILIZATION
HAS OCCURRED DUE TO NOCTURNAL COOLING...THE STEEP LAPSE RATE
ENVIRONMENT SAMPLED BY THE 00Z DVN RAOB WOULD AT LEAST SUPPORT THE
POSSIBILITY FOR DMGG WIND GUSTS.  ANY LIMITED TORNADO THREAT WILL
LIKELY CONTINUE TO DIMINISH BUT REMAIN NON-ZERO GIVEN THE STRONG LOW
LEVEL WIND PROFILE.  COUNTIES CAN BE CLEARED FROM TORNADO WATCH 187
FROM WEST TO EAST IN ASSOCIATION WITH SQUALL LINE PASSAGE.

..SMITH.. 05/20/2013

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

ATTN...WFO...GRB...LOT...ILX...MKX...LSX...DVN...ARX...MPX...

LAT...LON   40239156 42109186 44379137 45349026 43558850 41738838
            40148980 40239156

000
ACUS11 KWNS 200317
SWOMCD
SPC MCD 200316
ILZ000-MOZ000-KSZ000-OKZ000-200415-

MESOSCALE DISCUSSION 0719
NWS STORM PREDICTION CENTER NORMAN OK
1016 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MUCH OF NRN-CNTRL-SWRN MO / FAR SERN KS

CONCERNING...TORNADO WATCH 186...

VALID 200316Z - 200415Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 186 CONTINUES.

SUMMARY...THE TRANSITION TO AN ISOLD DMGG WIND THREAT AS THE PRIMARY
HAZARD APPEARS TO BE EVOLVING ACROSS CNTRL AND NRN MO.

DISCUSSION...RADAR MOSAIC SHOWS A DECAYING SQUALL LINE FROM NERN MO
SSWWD TO 20 MI E OF SGF.  FARTHER W...A FINE LINE IN REFLECTIVITY
DENOTES A GUST FRONT THAT HAS SURGED WELL AHEAD OF AN INTENSIFYING
SQUALL LINE ALONG THE KS/MO BORDER.  SUBSTANTIAL CONVECTIVE
OVERTURNING HAS OCCURRED ACROSS NRN MO AND TO AN EXTENT PORTIONS OF
CNTRL MO --THEREBY LIMITING THE POSSIBILITY FOR A TORNADO IN THIS
AREA.  FARTHER S OVER SWRN MO...A MODERATELY UNSTABLE AIRMASS
CONTINUES TO RESIDE ALTHOUGH CINH IS INCREASING OWING IN PART TO
DIURNAL COOLING.

THE AFOREMENTIONED CAPPING CONCERNS MAY PARTIALLY LIMIT THE SEVERE
THREAT...BUT A STRONG 50-60 KT LLJ SAMPLED BY THE KSGF/KLSX VWP/S
AND IMPLIED WAA REGIME IN PLACE...SUGGEST SOME WIND DAMAGE RISK WILL
CONTINUE OVER CNTRL-SRN MO...IN ADDITION TO A NON-ZERO TORNADO
POSSIBILITY.

..SMITH.. 05/20/2013

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

ATTN...WFO...ILX...LSX...DVN...SGF...EAX...TSA...

LAT...LON   37009504 37829502 40479340 39989055 38329139 36559340
            36539434 37009504

000
ACUS11 KWNS 200317
SWOMCD
SPC MCD 200316
ILZ000-MOZ000-KSZ000-OKZ000-200415-

MESOSCALE DISCUSSION 0719
NWS STORM PREDICTION CENTER NORMAN OK
1016 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MUCH OF NRN-CNTRL-SWRN MO / FAR SERN KS

CONCERNING...TORNADO WATCH 186...

VALID 200316Z - 200415Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 186 CONTINUES.

SUMMARY...THE TRANSITION TO AN ISOLD DMGG WIND THREAT AS THE PRIMARY
HAZARD APPEARS TO BE EVOLVING ACROSS CNTRL AND NRN MO.

DISCUSSION...RADAR MOSAIC SHOWS A DECAYING SQUALL LINE FROM NERN MO
SSWWD TO 20 MI E OF SGF.  FARTHER W...A FINE LINE IN REFLECTIVITY
DENOTES A GUST FRONT THAT HAS SURGED WELL AHEAD OF AN INTENSIFYING
SQUALL LINE ALONG THE KS/MO BORDER.  SUBSTANTIAL CONVECTIVE
OVERTURNING HAS OCCURRED ACROSS NRN MO AND TO AN EXTENT PORTIONS OF
CNTRL MO --THEREBY LIMITING THE POSSIBILITY FOR A TORNADO IN THIS
AREA.  FARTHER S OVER SWRN MO...A MODERATELY UNSTABLE AIRMASS
CONTINUES TO RESIDE ALTHOUGH CINH IS INCREASING OWING IN PART TO
DIURNAL COOLING.

THE AFOREMENTIONED CAPPING CONCERNS MAY PARTIALLY LIMIT THE SEVERE
THREAT...BUT A STRONG 50-60 KT LLJ SAMPLED BY THE KSGF/KLSX VWP/S
AND IMPLIED WAA REGIME IN PLACE...SUGGEST SOME WIND DAMAGE RISK WILL
CONTINUE OVER CNTRL-SRN MO...IN ADDITION TO A NON-ZERO TORNADO
POSSIBILITY.

..SMITH.. 05/20/2013

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

ATTN...WFO...ILX...LSX...DVN...SGF...EAX...TSA...

LAT...LON   37009504 37829502 40479340 39989055 38329139 36559340
            36539434 37009504

000
ACUS11 KWNS 200317
SWOMCD
SPC MCD 200316
ILZ000-MOZ000-KSZ000-OKZ000-200415-

MESOSCALE DISCUSSION 0719
NWS STORM PREDICTION CENTER NORMAN OK
1016 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MUCH OF NRN-CNTRL-SWRN MO / FAR SERN KS

CONCERNING...TORNADO WATCH 186...

VALID 200316Z - 200415Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 186 CONTINUES.

SUMMARY...THE TRANSITION TO AN ISOLD DMGG WIND THREAT AS THE PRIMARY
HAZARD APPEARS TO BE EVOLVING ACROSS CNTRL AND NRN MO.

DISCUSSION...RADAR MOSAIC SHOWS A DECAYING SQUALL LINE FROM NERN MO
SSWWD TO 20 MI E OF SGF.  FARTHER W...A FINE LINE IN REFLECTIVITY
DENOTES A GUST FRONT THAT HAS SURGED WELL AHEAD OF AN INTENSIFYING
SQUALL LINE ALONG THE KS/MO BORDER.  SUBSTANTIAL CONVECTIVE
OVERTURNING HAS OCCURRED ACROSS NRN MO AND TO AN EXTENT PORTIONS OF
CNTRL MO --THEREBY LIMITING THE POSSIBILITY FOR A TORNADO IN THIS
AREA.  FARTHER S OVER SWRN MO...A MODERATELY UNSTABLE AIRMASS
CONTINUES TO RESIDE ALTHOUGH CINH IS INCREASING OWING IN PART TO
DIURNAL COOLING.

THE AFOREMENTIONED CAPPING CONCERNS MAY PARTIALLY LIMIT THE SEVERE
THREAT...BUT A STRONG 50-60 KT LLJ SAMPLED BY THE KSGF/KLSX VWP/S
AND IMPLIED WAA REGIME IN PLACE...SUGGEST SOME WIND DAMAGE RISK WILL
CONTINUE OVER CNTRL-SRN MO...IN ADDITION TO A NON-ZERO TORNADO
POSSIBILITY.

..SMITH.. 05/20/2013

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

ATTN...WFO...ILX...LSX...DVN...SGF...EAX...TSA...

LAT...LON   37009504 37829502 40479340 39989055 38329139 36559340
            36539434 37009504

000
ACUS11 KWNS 200238
SWOMCD
SPC MCD 200238
MIZ000-WIZ000-200345-

MESOSCALE DISCUSSION 0718
NWS STORM PREDICTION CENTER NORMAN OK
0938 PM CDT SUN MAY 19 2013

AREAS AFFECTED...N-CNTRL WI

CONCERNING...TORNADO WATCH 185...

VALID 200238Z - 200345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 185 CONTINUES.

SUMMARY...ISOLATED SEVERE WEATHER REMAINS POSSIBLE ACROSS REMAINING
PORTION OF WATCH THROUGH 04Z.

DISCUSSION...AS OF 0230Z...REGIONAL RADAR IMAGERY SHOWED THE NRN
EXTENSION OF A QLCS WITH EMBEDDED SMALL-SCALE BOWING STRUCTURES OVER
ASHLAND...IRON...AND PRICE COUNTIES.  WHILE LOCALLY STRONG WIND
GUSTS REMAIN POSSIBLE...THESE STORMS ARE RAPIDLY ADVANCING INTO AN
INCREASINGLY DRIER AND MORE STABLE ENVIRONMENT.  AS SUCH...ORGANIZED
SEVERE WEATHER POTENTIAL SHOULD CONTINUE TO DIMINISH THROUGH 04Z.

..MEAD.. 05/20/2013

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

ATTN...WFO...MQT...DLH...ARX...MPX...

LAT...LON   45089169 45659117 46099090 46469086 46579058 46359005
            45859010 45499021 45089110 44719164 45089169

000
ACUS11 KWNS 200238
SWOMCD
SPC MCD 200238
MIZ000-WIZ000-200345-

MESOSCALE DISCUSSION 0718
NWS STORM PREDICTION CENTER NORMAN OK
0938 PM CDT SUN MAY 19 2013

AREAS AFFECTED...N-CNTRL WI

CONCERNING...TORNADO WATCH 185...

VALID 200238Z - 200345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 185 CONTINUES.

SUMMARY...ISOLATED SEVERE WEATHER REMAINS POSSIBLE ACROSS REMAINING
PORTION OF WATCH THROUGH 04Z.

DISCUSSION...AS OF 0230Z...REGIONAL RADAR IMAGERY SHOWED THE NRN
EXTENSION OF A QLCS WITH EMBEDDED SMALL-SCALE BOWING STRUCTURES OVER
ASHLAND...IRON...AND PRICE COUNTIES.  WHILE LOCALLY STRONG WIND
GUSTS REMAIN POSSIBLE...THESE STORMS ARE RAPIDLY ADVANCING INTO AN
INCREASINGLY DRIER AND MORE STABLE ENVIRONMENT.  AS SUCH...ORGANIZED
SEVERE WEATHER POTENTIAL SHOULD CONTINUE TO DIMINISH THROUGH 04Z.

..MEAD.. 05/20/2013

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

ATTN...WFO...MQT...DLH...ARX...MPX...

LAT...LON   45089169 45659117 46099090 46469086 46579058 46359005
            45859010 45499021 45089110 44719164 45089169

000
ACUS11 KWNS 200235
SWOMCD
SPC MCD 200234
KSZ000-OKZ000-200300-

MESOSCALE DISCUSSION 0717
NWS STORM PREDICTION CENTER NORMAN OK
0934 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN KS

CONCERNING...TORNADO WATCH 181...

VALID 200234Z - 200300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...A LOCAL WATCH EXTENSION-IN-TIME MAY BEST ADDRESS THE
REMAINING SEVERE THREAT THIS EVENING.

DISCUSSION...RADAR/SURFACE COMPOSITE SHOWS A GUST FRONT/OUTFLOW
DISPLACED AHEAD OF THE SW-NE ORIENTED BAND OF STORMS FROM N-CNTRL OK
INTO SERN KS.  SURFACE WINDS BEHIND THIS BOUNDARY HAVE RECENT VEERED
CONCURRENT WITH THE GUST FRONT PASSAGE --SEEMINGLY LIMITING TORNADO
POTENTIAL.  UNTIL STORMS CONVECTIVELY OVERTURN
MONTGOMERY/NEOSHO/LABETTE COUNTIES AND DECREASE SEVERE POTENTIAL...A
LOCAL WATCH EXTENSION-IN-TIME CAN BE UTILIZED AS AN OPTION IF A
SEVERE THREAT APPEARS TO PERSIST BEYOND 03Z.

..SMITH.. 05/20/2013

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

ATTN...WFO...SGF...TSA...ICT...

LAT...LON   36979653 37829546 37529506 37119516 36979556 36979653

000
ACUS11 KWNS 200235
SWOMCD
SPC MCD 200234
KSZ000-OKZ000-200300-

MESOSCALE DISCUSSION 0717
NWS STORM PREDICTION CENTER NORMAN OK
0934 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN KS

CONCERNING...TORNADO WATCH 181...

VALID 200234Z - 200300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...A LOCAL WATCH EXTENSION-IN-TIME MAY BEST ADDRESS THE
REMAINING SEVERE THREAT THIS EVENING.

DISCUSSION...RADAR/SURFACE COMPOSITE SHOWS A GUST FRONT/OUTFLOW
DISPLACED AHEAD OF THE SW-NE ORIENTED BAND OF STORMS FROM N-CNTRL OK
INTO SERN KS.  SURFACE WINDS BEHIND THIS BOUNDARY HAVE RECENT VEERED
CONCURRENT WITH THE GUST FRONT PASSAGE --SEEMINGLY LIMITING TORNADO
POTENTIAL.  UNTIL STORMS CONVECTIVELY OVERTURN
MONTGOMERY/NEOSHO/LABETTE COUNTIES AND DECREASE SEVERE POTENTIAL...A
LOCAL WATCH EXTENSION-IN-TIME CAN BE UTILIZED AS AN OPTION IF A
SEVERE THREAT APPEARS TO PERSIST BEYOND 03Z.

..SMITH.. 05/20/2013

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

ATTN...WFO...SGF...TSA...ICT...

LAT...LON   36979653 37829546 37529506 37119516 36979556 36979653

000
ACUS11 KWNS 200235
SWOMCD
SPC MCD 200234
KSZ000-OKZ000-200300-

MESOSCALE DISCUSSION 0717
NWS STORM PREDICTION CENTER NORMAN OK
0934 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN KS

CONCERNING...TORNADO WATCH 181...

VALID 200234Z - 200300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...A LOCAL WATCH EXTENSION-IN-TIME MAY BEST ADDRESS THE
REMAINING SEVERE THREAT THIS EVENING.

DISCUSSION...RADAR/SURFACE COMPOSITE SHOWS A GUST FRONT/OUTFLOW
DISPLACED AHEAD OF THE SW-NE ORIENTED BAND OF STORMS FROM N-CNTRL OK
INTO SERN KS.  SURFACE WINDS BEHIND THIS BOUNDARY HAVE RECENT VEERED
CONCURRENT WITH THE GUST FRONT PASSAGE --SEEMINGLY LIMITING TORNADO
POTENTIAL.  UNTIL STORMS CONVECTIVELY OVERTURN
MONTGOMERY/NEOSHO/LABETTE COUNTIES AND DECREASE SEVERE POTENTIAL...A
LOCAL WATCH EXTENSION-IN-TIME CAN BE UTILIZED AS AN OPTION IF A
SEVERE THREAT APPEARS TO PERSIST BEYOND 03Z.

..SMITH.. 05/20/2013

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

ATTN...WFO...SGF...TSA...ICT...

LAT...LON   36979653 37829546 37529506 37119516 36979556 36979653

000
ACUS11 KWNS 200227
SWOMCD
SPC MCD 200226
IAZ000-NEZ000-200330-

MESOSCALE DISCUSSION 0716
NWS STORM PREDICTION CENTER NORMAN OK
0926 PM CDT SUN MAY 19 2013

AREAS AFFECTED...S-CNTRL INTO NERN NEB

CONCERNING...SEVERE THUNDERSTORM WATCH 184...

VALID 200226Z - 200330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 184
CONTINUES.

SUMMARY...THE SEVERE WEATHER THREAT SHOULD CONTINUE TO DIMINISH
THROUGH 03-04Z ACROSS REMAINING VALID PORTION OF WATCH AREA.

DISCUSSION...A QLCS WITH DISTINCT BOOKEND VORTEX WHICH EVOLVED
EARLIER THIS EVENING OVER ERN NEB HAS RECENTLY SHOWN A WEAKENING
TREND AS IT APPROACHES THE MO RIVER.  IT APPEARS THAT THIS SYSTEM IS
BEING TO INGEST RAIN-COOLED AIR IN THE WAKE OF A LARGER-SCALE MCS
EVOLVING FARTHER TO THE EAST ACROSS IA AND MO.  THUS...WHILE AN
ISOLATED WIND/HAIL THREAT MAY PERSIST THROUGH 03-04Z...IT APPEARS
THAT MORE ORGANIZED SEVERE POTENTIAL HAS DIMINISHED.

..MEAD.. 05/20/2013

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

ATTN...WFO...OAX...

LAT...LON   41229733 42219725 42239653 41769600 41279592 41119616
            41089654 41059710 41229733

000
ACUS11 KWNS 200227
SWOMCD
SPC MCD 200226
IAZ000-NEZ000-200330-

MESOSCALE DISCUSSION 0716
NWS STORM PREDICTION CENTER NORMAN OK
0926 PM CDT SUN MAY 19 2013

AREAS AFFECTED...S-CNTRL INTO NERN NEB

CONCERNING...SEVERE THUNDERSTORM WATCH 184...

VALID 200226Z - 200330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 184
CONTINUES.

SUMMARY...THE SEVERE WEATHER THREAT SHOULD CONTINUE TO DIMINISH
THROUGH 03-04Z ACROSS REMAINING VALID PORTION OF WATCH AREA.

DISCUSSION...A QLCS WITH DISTINCT BOOKEND VORTEX WHICH EVOLVED
EARLIER THIS EVENING OVER ERN NEB HAS RECENTLY SHOWN A WEAKENING
TREND AS IT APPROACHES THE MO RIVER.  IT APPEARS THAT THIS SYSTEM IS
BEING TO INGEST RAIN-COOLED AIR IN THE WAKE OF A LARGER-SCALE MCS
EVOLVING FARTHER TO THE EAST ACROSS IA AND MO.  THUS...WHILE AN
ISOLATED WIND/HAIL THREAT MAY PERSIST THROUGH 03-04Z...IT APPEARS
THAT MORE ORGANIZED SEVERE POTENTIAL HAS DIMINISHED.

..MEAD.. 05/20/2013

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

ATTN...WFO...OAX...

LAT...LON   41229733 42219725 42239653 41769600 41279592 41119616
            41089654 41059710 41229733

000
ACUS11 KWNS 200227
SWOMCD
SPC MCD 200226
IAZ000-NEZ000-200330-

MESOSCALE DISCUSSION 0716
NWS STORM PREDICTION CENTER NORMAN OK
0926 PM CDT SUN MAY 19 2013

AREAS AFFECTED...S-CNTRL INTO NERN NEB

CONCERNING...SEVERE THUNDERSTORM WATCH 184...

VALID 200226Z - 200330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 184
CONTINUES.

SUMMARY...THE SEVERE WEATHER THREAT SHOULD CONTINUE TO DIMINISH
THROUGH 03-04Z ACROSS REMAINING VALID PORTION OF WATCH AREA.

DISCUSSION...A QLCS WITH DISTINCT BOOKEND VORTEX WHICH EVOLVED
EARLIER THIS EVENING OVER ERN NEB HAS RECENTLY SHOWN A WEAKENING
TREND AS IT APPROACHES THE MO RIVER.  IT APPEARS THAT THIS SYSTEM IS
BEING TO INGEST RAIN-COOLED AIR IN THE WAKE OF A LARGER-SCALE MCS
EVOLVING FARTHER TO THE EAST ACROSS IA AND MO.  THUS...WHILE AN
ISOLATED WIND/HAIL THREAT MAY PERSIST THROUGH 03-04Z...IT APPEARS
THAT MORE ORGANIZED SEVERE POTENTIAL HAS DIMINISHED.

..MEAD.. 05/20/2013

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

ATTN...WFO...OAX...

LAT...LON   41229733 42219725 42239653 41769600 41279592 41119616
            41089654 41059710 41229733

000
ACUS11 KWNS 200211
SWOMCD
SPC MCD 200211
IAZ000-200315-

MESOSCALE DISCUSSION 0715
NWS STORM PREDICTION CENTER NORMAN OK
0911 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL IA

CONCERNING...TORNADO WATCH 183...

VALID 200211Z - 200315Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 183 CONTINUES.

SUMMARY...AN ISOLATED SEVERE WEATHER THREAT MAY PERSIST BEYOND THE
03Z EXPIRATION OF TORNADO WATCH 183.  AS SUCH...A LOCAL EXTENSION IN
TIME COULD BE REQUIRED.

DISCUSSION...TSTMS HAVE BECOME WIDESPREAD ACROSS S-CNTRL IA WITHIN A
ZONE OF DCVA ATTENDANT TO A MIDLEVEL VORTICITY MAXIMUM PIVOTING NEWD
THROUGH THE LOWER-MO VALLEY.  THE AIR MASS AHEAD OF ONGOING STORMS
REMAINS AT LEAST MODESTLY UNSTABLE...AND GIVEN THE COLOCATION OF A
700-500-MB WIND MAXIMUM...SUFFICIENT VERTICAL SHEAR EXISTS TO
SUPPORT ORGANIZED STORM STRUCTURES WITH A CONTINUED RISK FOR SEVERE
WEATHER.

TO THE WEST OF THE ONGOING STORMS...THE SEVERE WEATHER THREAT HAS
DIMINISHED AND EXISTING PORTIONS OF WATCH CAN BE CLEARED OR ALLOWED
TO EXPIRE AT 03Z.

..MEAD.. 05/20/2013

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

ATTN...WFO...DMX...

LAT...LON   41499332 42119318 42289258 41919230 41329255 40909228
            40649240 40639318 40649369 40779388 41499332

000
ACUS11 KWNS 200211
SWOMCD
SPC MCD 200211
IAZ000-200315-

MESOSCALE DISCUSSION 0715
NWS STORM PREDICTION CENTER NORMAN OK
0911 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL IA

CONCERNING...TORNADO WATCH 183...

VALID 200211Z - 200315Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 183 CONTINUES.

SUMMARY...AN ISOLATED SEVERE WEATHER THREAT MAY PERSIST BEYOND THE
03Z EXPIRATION OF TORNADO WATCH 183.  AS SUCH...A LOCAL EXTENSION IN
TIME COULD BE REQUIRED.

DISCUSSION...TSTMS HAVE BECOME WIDESPREAD ACROSS S-CNTRL IA WITHIN A
ZONE OF DCVA ATTENDANT TO A MIDLEVEL VORTICITY MAXIMUM PIVOTING NEWD
THROUGH THE LOWER-MO VALLEY.  THE AIR MASS AHEAD OF ONGOING STORMS
REMAINS AT LEAST MODESTLY UNSTABLE...AND GIVEN THE COLOCATION OF A
700-500-MB WIND MAXIMUM...SUFFICIENT VERTICAL SHEAR EXISTS TO
SUPPORT ORGANIZED STORM STRUCTURES WITH A CONTINUED RISK FOR SEVERE
WEATHER.

TO THE WEST OF THE ONGOING STORMS...THE SEVERE WEATHER THREAT HAS
DIMINISHED AND EXISTING PORTIONS OF WATCH CAN BE CLEARED OR ALLOWED
TO EXPIRE AT 03Z.

..MEAD.. 05/20/2013

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

ATTN...WFO...DMX...

LAT...LON   41499332 42119318 42289258 41919230 41329255 40909228
            40649240 40639318 40649369 40779388 41499332

000
ACUS11 KWNS 200211
SWOMCD
SPC MCD 200211
IAZ000-200315-

MESOSCALE DISCUSSION 0715
NWS STORM PREDICTION CENTER NORMAN OK
0911 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL IA

CONCERNING...TORNADO WATCH 183...

VALID 200211Z - 200315Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 183 CONTINUES.

SUMMARY...AN ISOLATED SEVERE WEATHER THREAT MAY PERSIST BEYOND THE
03Z EXPIRATION OF TORNADO WATCH 183.  AS SUCH...A LOCAL EXTENSION IN
TIME COULD BE REQUIRED.

DISCUSSION...TSTMS HAVE BECOME WIDESPREAD ACROSS S-CNTRL IA WITHIN A
ZONE OF DCVA ATTENDANT TO A MIDLEVEL VORTICITY MAXIMUM PIVOTING NEWD
THROUGH THE LOWER-MO VALLEY.  THE AIR MASS AHEAD OF ONGOING STORMS
REMAINS AT LEAST MODESTLY UNSTABLE...AND GIVEN THE COLOCATION OF A
700-500-MB WIND MAXIMUM...SUFFICIENT VERTICAL SHEAR EXISTS TO
SUPPORT ORGANIZED STORM STRUCTURES WITH A CONTINUED RISK FOR SEVERE
WEATHER.

TO THE WEST OF THE ONGOING STORMS...THE SEVERE WEATHER THREAT HAS
DIMINISHED AND EXISTING PORTIONS OF WATCH CAN BE CLEARED OR ALLOWED
TO EXPIRE AT 03Z.

..MEAD.. 05/20/2013

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

ATTN...WFO...DMX...

LAT...LON   41499332 42119318 42289258 41919230 41329255 40909228
            40649240 40639318 40649369 40779388 41499332

000
ACUS11 KWNS 200153
SWOMCD
SPC MCD 200153
ARZ000-MOZ000-OKZ000-TXZ000-200300-

MESOSCALE DISCUSSION 0714
NWS STORM PREDICTION CENTER NORMAN OK
0853 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-ERN OK

CONCERNING...TORNADO WATCH 182...

VALID 200153Z - 200300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 182 CONTINUES.

SUMMARY...ONLY MEAGER PROSPECTS FOR ADDITIONAL STORM DEVELOPMENT
EXIST S OF I-40...ESPECIALLY OVER S-CNTRL OK.

DISCUSSION...SURFACE ANALYSIS SHOWS A DRYLINE EXTENDING FROM 15 MI
NNE SPS NNEWD TO 40 MI WNW PNC.  THE AIRMASS E OF THE DRYLINE IS
RATHER MOIST WITH UPPER 60S TO NEAR 70 DEG DEWPOINTS BENEATH VERY
STEEP MID LEVEL LAPSE RATES.  VISIBLE IMAGERY SHOWS LITTLE IF ANY
CUMULUS REMAINING ON THE DRYLINE FROM NEAR THE OKC METRO SWD TO THE
RED RIVER AS OF 0045Z.  AS BOUNDARY LAYER COOLING COMMENCES WITH THE
LOSS OF DAYTIME HEATING...INCREASING CINH/CAPPING INVERSION WILL
SEEMINGLY LIMIT AND PROVE DETRIMENTAL FOR ADDITIONAL STORMS FROM
I-40 SWD.  AS A RESULT...COUNTIES OVER SRN OK MAY BEGIN TO BE
REMOVED FROM TORNADO WATCH 182 OVER THE NEXT HOUR.

FARTHER N OVER NERN OK AND N-CNTRL OK...A STRONG LOW LEVEL WIND
PROFILE WILL AT LEAST BE SUPPORTIVE OF AT LEAST SOME CONDITIONAL
TORNADIC THREAT IF STORMS CAN ACQUIRE ROBUST LOW LEVEL MESOCYCLONES.
A POSSIBLE WATCH REPLACEMENT COULD BE UTILIZED FOR NERN OK BEFORE
THE 04Z WATCH EXPIRATION TIME AS THIS AREA IS LOCATED FARTHER N AND
UNDER MORE INFLUENCE OF THE CYCLONICALLY CURVED UPPER JET.
CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.

..SMITH.. 05/20/2013

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

ATTN...WFO...SGF...SHV...TSA...FWD...OUN...

LAT...LON   34149868 36949773 36989462 34639446 33919535 33849730
            34149868

000
ACUS11 KWNS 200153
SWOMCD
SPC MCD 200153
ARZ000-MOZ000-OKZ000-TXZ000-200300-

MESOSCALE DISCUSSION 0714
NWS STORM PREDICTION CENTER NORMAN OK
0853 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-ERN OK

CONCERNING...TORNADO WATCH 182...

VALID 200153Z - 200300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 182 CONTINUES.

SUMMARY...ONLY MEAGER PROSPECTS FOR ADDITIONAL STORM DEVELOPMENT
EXIST S OF I-40...ESPECIALLY OVER S-CNTRL OK.

DISCUSSION...SURFACE ANALYSIS SHOWS A DRYLINE EXTENDING FROM 15 MI
NNE SPS NNEWD TO 40 MI WNW PNC.  THE AIRMASS E OF THE DRYLINE IS
RATHER MOIST WITH UPPER 60S TO NEAR 70 DEG DEWPOINTS BENEATH VERY
STEEP MID LEVEL LAPSE RATES.  VISIBLE IMAGERY SHOWS LITTLE IF ANY
CUMULUS REMAINING ON THE DRYLINE FROM NEAR THE OKC METRO SWD TO THE
RED RIVER AS OF 0045Z.  AS BOUNDARY LAYER COOLING COMMENCES WITH THE
LOSS OF DAYTIME HEATING...INCREASING CINH/CAPPING INVERSION WILL
SEEMINGLY LIMIT AND PROVE DETRIMENTAL FOR ADDITIONAL STORMS FROM
I-40 SWD.  AS A RESULT...COUNTIES OVER SRN OK MAY BEGIN TO BE
REMOVED FROM TORNADO WATCH 182 OVER THE NEXT HOUR.

FARTHER N OVER NERN OK AND N-CNTRL OK...A STRONG LOW LEVEL WIND
PROFILE WILL AT LEAST BE SUPPORTIVE OF AT LEAST SOME CONDITIONAL
TORNADIC THREAT IF STORMS CAN ACQUIRE ROBUST LOW LEVEL MESOCYCLONES.
A POSSIBLE WATCH REPLACEMENT COULD BE UTILIZED FOR NERN OK BEFORE
THE 04Z WATCH EXPIRATION TIME AS THIS AREA IS LOCATED FARTHER N AND
UNDER MORE INFLUENCE OF THE CYCLONICALLY CURVED UPPER JET.
CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.

..SMITH.. 05/20/2013

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

ATTN...WFO...SGF...SHV...TSA...FWD...OUN...

LAT...LON   34149868 36949773 36989462 34639446 33919535 33849730
            34149868

000
ACUS11 KWNS 200153
SWOMCD
SPC MCD 200153
ARZ000-MOZ000-OKZ000-TXZ000-200300-

MESOSCALE DISCUSSION 0714
NWS STORM PREDICTION CENTER NORMAN OK
0853 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-ERN OK

CONCERNING...TORNADO WATCH 182...

VALID 200153Z - 200300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 182 CONTINUES.

SUMMARY...ONLY MEAGER PROSPECTS FOR ADDITIONAL STORM DEVELOPMENT
EXIST S OF I-40...ESPECIALLY OVER S-CNTRL OK.

DISCUSSION...SURFACE ANALYSIS SHOWS A DRYLINE EXTENDING FROM 15 MI
NNE SPS NNEWD TO 40 MI WNW PNC.  THE AIRMASS E OF THE DRYLINE IS
RATHER MOIST WITH UPPER 60S TO NEAR 70 DEG DEWPOINTS BENEATH VERY
STEEP MID LEVEL LAPSE RATES.  VISIBLE IMAGERY SHOWS LITTLE IF ANY
CUMULUS REMAINING ON THE DRYLINE FROM NEAR THE OKC METRO SWD TO THE
RED RIVER AS OF 0045Z.  AS BOUNDARY LAYER COOLING COMMENCES WITH THE
LOSS OF DAYTIME HEATING...INCREASING CINH/CAPPING INVERSION WILL
SEEMINGLY LIMIT AND PROVE DETRIMENTAL FOR ADDITIONAL STORMS FROM
I-40 SWD.  AS A RESULT...COUNTIES OVER SRN OK MAY BEGIN TO BE
REMOVED FROM TORNADO WATCH 182 OVER THE NEXT HOUR.

FARTHER N OVER NERN OK AND N-CNTRL OK...A STRONG LOW LEVEL WIND
PROFILE WILL AT LEAST BE SUPPORTIVE OF AT LEAST SOME CONDITIONAL
TORNADIC THREAT IF STORMS CAN ACQUIRE ROBUST LOW LEVEL MESOCYCLONES.
A POSSIBLE WATCH REPLACEMENT COULD BE UTILIZED FOR NERN OK BEFORE
THE 04Z WATCH EXPIRATION TIME AS THIS AREA IS LOCATED FARTHER N AND
UNDER MORE INFLUENCE OF THE CYCLONICALLY CURVED UPPER JET.
CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.

..SMITH.. 05/20/2013

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

ATTN...WFO...SGF...SHV...TSA...FWD...OUN...

LAT...LON   34149868 36949773 36989462 34639446 33919535 33849730
            34149868

000
ACUS11 KWNS 200121
SWOMCD
SPC MCD 200121
IAZ000-WIZ000-MNZ000-200215-

MESOSCALE DISCUSSION 0713
NWS STORM PREDICTION CENTER NORMAN OK
0821 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN MN INTO NRN IA

CONCERNING...TORNADO WATCH 180...

VALID 200121Z - 200215Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 180 CONTINUES.

SUMMARY...THE THREAT FOR ORGANIZED SEVERE WEATHER IS EXPECTED TO
DIMINISH ACROSS REMAINING VALID PARTS OF WATCH AREA.  AS SUCH...THE
WATCH CAN BE ALLOWED TO EXPIRE AT 02Z.

DISCUSSION...THE 00Z MPX SOUNDING INDICATES THAT CONSIDERABLE
CONVECTIVE OVERTURNING HAS OCCURRED WITH THE EARLIER PASSAGE OF
SEVERE STORMS.  MOREOVER...REGION IS LIKELY IN A ZONE OF SUBSIDENCE
IN THE WAKE OF AN MCV PROGRESSING NWD INTO N-CNTRL MN.  AS
SUCH...THE REMAINING VALID PORTION OF THE WATCH CAN BE ALLOWED TO
EXPIRE AT 02Z.

..MEAD.. 05/20/2013

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

ATTN...WFO...ARX...MPX...DMX...FSD...

LAT...LON   44609515 45409512 45659458 45469372 45579322 45529260
            44859231 44549240 44169292 43889331 43019324 42749279
            42709236 42439255 42319313 42309369 42359424 42579465
            44609515

000
ACUS11 KWNS 200121
SWOMCD
SPC MCD 200121
IAZ000-WIZ000-MNZ000-200215-

MESOSCALE DISCUSSION 0713
NWS STORM PREDICTION CENTER NORMAN OK
0821 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN MN INTO NRN IA

CONCERNING...TORNADO WATCH 180...

VALID 200121Z - 200215Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 180 CONTINUES.

SUMMARY...THE THREAT FOR ORGANIZED SEVERE WEATHER IS EXPECTED TO
DIMINISH ACROSS REMAINING VALID PARTS OF WATCH AREA.  AS SUCH...THE
WATCH CAN BE ALLOWED TO EXPIRE AT 02Z.

DISCUSSION...THE 00Z MPX SOUNDING INDICATES THAT CONSIDERABLE
CONVECTIVE OVERTURNING HAS OCCURRED WITH THE EARLIER PASSAGE OF
SEVERE STORMS.  MOREOVER...REGION IS LIKELY IN A ZONE OF SUBSIDENCE
IN THE WAKE OF AN MCV PROGRESSING NWD INTO N-CNTRL MN.  AS
SUCH...THE REMAINING VALID PORTION OF THE WATCH CAN BE ALLOWED TO
EXPIRE AT 02Z.

..MEAD.. 05/20/2013

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

ATTN...WFO...ARX...MPX...DMX...FSD...

LAT...LON   44609515 45409512 45659458 45469372 45579322 45529260
            44859231 44549240 44169292 43889331 43019324 42749279
            42709236 42439255 42319313 42309369 42359424 42579465
            44609515

000
ACUS11 KWNS 200121
SWOMCD
SPC MCD 200121
IAZ000-WIZ000-MNZ000-200215-

MESOSCALE DISCUSSION 0713
NWS STORM PREDICTION CENTER NORMAN OK
0821 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN MN INTO NRN IA

CONCERNING...TORNADO WATCH 180...

VALID 200121Z - 200215Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 180 CONTINUES.

SUMMARY...THE THREAT FOR ORGANIZED SEVERE WEATHER IS EXPECTED TO
DIMINISH ACROSS REMAINING VALID PARTS OF WATCH AREA.  AS SUCH...THE
WATCH CAN BE ALLOWED TO EXPIRE AT 02Z.

DISCUSSION...THE 00Z MPX SOUNDING INDICATES THAT CONSIDERABLE
CONVECTIVE OVERTURNING HAS OCCURRED WITH THE EARLIER PASSAGE OF
SEVERE STORMS.  MOREOVER...REGION IS LIKELY IN A ZONE OF SUBSIDENCE
IN THE WAKE OF AN MCV PROGRESSING NWD INTO N-CNTRL MN.  AS
SUCH...THE REMAINING VALID PORTION OF THE WATCH CAN BE ALLOWED TO
EXPIRE AT 02Z.

..MEAD.. 05/20/2013

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

ATTN...WFO...ARX...MPX...DMX...FSD...

LAT...LON   44609515 45409512 45659458 45469372 45579322 45529260
            44859231 44549240 44169292 43889331 43019324 42749279
            42709236 42439255 42319313 42309369 42359424 42579465
            44609515

000
ACUS01 KWNS 200102
SWODY1
SPC AC 200100

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0800 PM CDT SUN MAY 19 2013

VALID 200100Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NORTHERN/EASTERN
OK AND SOUTHEAST KS INTO MO...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL/SOUTHERN
PLAINS TO THE MIDWEST/UPPER MS VALLEY...

...SOUTH-CENTRAL PLAINS TO MIDWEST/UPPER MS VALLEY...
A SCATTERED SUPERCELL OR TWO REMAINING CAPABLE OF A STRONG TORNADO
WILL REMAIN A DISTINCT CONCERN ESPECIALLY OVER THE NEXT FEW HOURS
/MID INTO LATE EVENING/ ACROSS EAST-CENTRAL/NORTHEAST OK...WITH
ADDITIONAL DEVELOPMENT INCLUDING SUPERCELLS ALONG A CONSOLIDATING
NORTHEAST-SOUTHWEST ORIENTED FRONTAL ZONE ACROSS KS INTO NORTHERN
OK.

MEANWHILE...TO THE NORTHEAST...MULTIPLE AMALGAMATING/UPSCALE GROWING
CLUSTERS WILL LIKELY CONTINUE TO EVOLVE ACROSS THE OZARKS/LOWER MO
VALLEY INTO THE MIDDLE/UPPER MS VALLEY. THE MOST SUBSTANTIAL UPSCALE
DEVELOPMENT/SUSTAINED LINEAR ORGANIZATION WILL LIKELY IMPACT THE
LOWER MO VALLEY/MIDDLE MS VALLEY TONIGHT...ESPECIALLY GIVEN
NOCTURNAL STRENGTHENING OF AN ALREADY MODERATELY STRONG SOUTHERLY
LOW LEVEL JET. POTENTIALLY WIDESPREAD DAMAGING WINDS WILL BE A
CONCERN ESPECIALLY ACROSS MO INTO EASTERN IA/FAR WESTERN IL...WITH A
FEW TORNADOES /POSSIBLY EVEN A STRONG ONE/ POSSIBLE IN ASSOCIATION
WITH EMBEDDED MESOVORTICES.

..GUYER.. 05/20/2013

000
ACUS01 KWNS 200102
SWODY1
SPC AC 200100

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0800 PM CDT SUN MAY 19 2013

VALID 200100Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NORTHERN/EASTERN
OK AND SOUTHEAST KS INTO MO...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CENTRAL/SOUTHERN
PLAINS TO THE MIDWEST/UPPER MS VALLEY...

...SOUTH-CENTRAL PLAINS TO MIDWEST/UPPER MS VALLEY...
A SCATTERED SUPERCELL OR TWO REMAINING CAPABLE OF A STRONG TORNADO
WILL REMAIN A DISTINCT CONCERN ESPECIALLY OVER THE NEXT FEW HOURS
/MID INTO LATE EVENING/ ACROSS EAST-CENTRAL/NORTHEAST OK...WITH
ADDITIONAL DEVELOPMENT INCLUDING SUPERCELLS ALONG A CONSOLIDATING
NORTHEAST-SOUTHWEST ORIENTED FRONTAL ZONE ACROSS KS INTO NORTHERN
OK.

MEANWHILE...TO THE NORTHEAST...MULTIPLE AMALGAMATING/UPSCALE GROWING
CLUSTERS WILL LIKELY CONTINUE TO EVOLVE ACROSS THE OZARKS/LOWER MO
VALLEY INTO THE MIDDLE/UPPER MS VALLEY. THE MOST SUBSTANTIAL UPSCALE
DEVELOPMENT/SUSTAINED LINEAR ORGANIZATION WILL LIKELY IMPACT THE
LOWER MO VALLEY/MIDDLE MS VALLEY TONIGHT...ESPECIALLY GIVEN
NOCTURNAL STRENGTHENING OF AN ALREADY MODERATELY STRONG SOUTHERLY
LOW LEVEL JET. POTENTIALLY WIDESPREAD DAMAGING WINDS WILL BE A
CONCERN ESPECIALLY ACROSS MO INTO EASTERN IA/FAR WESTERN IL...WITH A
FEW TORNADOES /POSSIBLY EVEN A STRONG ONE/ POSSIBLE IN ASSOCIATION
WITH EMBEDDED MESOVORTICES.

..GUYER.. 05/20/2013

000
ACUS11 KWNS 200055
SWOMCD
SPC MCD 200055
MOZ000-IAZ000-KSZ000-NEZ000-OKZ000-200200-

MESOSCALE DISCUSSION 0712
NWS STORM PREDICTION CENTER NORMAN OK
0755 PM CDT SUN MAY 19 2013

AREAS AFFECTED...ERN - NERN - AND N-CNTRL KS / SERN NEB / NWRN MO

CONCERNING...TORNADO WATCH 181...

VALID 200055Z - 200200Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...THE TORNADO THREAT IS SEEMINGLY CONFINED TO THE QLCS ALONG
THE KS/MO BORDER AND OVER SERN KS.

DISCUSSION...SUBJECTIVE SURFACE MESOANALYSIS SHOWS MUCH OF N-CNTRL
AND NERN KS IN A RAIN-COOLED/PARTIAL CONVECTIVELY OVERTURNED AIRMASS
WITH TEMPS IN THE 60S/LOWER 70S.  SOME VIGOR HAS BEEN NOTED ON THE
WRN EDGE OF THE TORNADO WATCH OVER N-CNTRL KS WHERE UPSTREAM
MID-LEVEL LAPSE RATES ARE STILL SUPPORTIVE FOR PERHAPS A LOCALLY
STRONG WIND GUST/MARGINALLY SEVERE HAIL THREAT.

FARTHER E ALONG THE KS/MO BORDER...A QLCS CONTINUES MOVING NEWD
ACROSS PORTIONS OF THE LOWER MO VALLEY.  KEAX RADAR IMAGERY SHOWS
ENHANCED POCKETS OF SEVERE WIND GUSTS IN ASSOCIATION WITH THE QLCS
PASSAGE.  ALTHOUGH THE TORNADO THREAT IS SOMEWHAT LIMITED GIVEN THE
CONVECTIVE MODE...A NON-ZERO TORNADIC MESOVORTEX THREAT IS STILL
POSSIBLE GIVEN THE STRONG LOW LEVEL SHEAR PROFILE OVER THIS REGION.

MORE CELLULAR STORMS HAVE DEVELOPED OVER S-CNTRL KS AND WILL LIKELY
CONTINUE TO INGEST A MOISTURE RICH/UNSTABLE AIRMASS FROM THE S.
STEEP LAPSE RATES WOULD SUPPORT AN ISOLD LARGE HAIL / LOCALLY
DAMAGING WIND THREAT.  A TORNADO OR TWO IS STILL POSSIBLE THIS
EVENING AS THE 50 KT LLJ FOCUSES TOWARDS THIS REGION.

..SMITH.. 05/20/2013

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

ATTN...WFO...DMX...EAX...TSA...OAX...TOP...ICT...OUN...GID...
DDC...

LAT...LON   38249847 39529818 40479759 40909670 40589476 40119395
            38079512 37029576 36939683 37449706 38009608 38529606
            38249847

000
ACUS11 KWNS 200055
SWOMCD
SPC MCD 200055
MOZ000-IAZ000-KSZ000-NEZ000-OKZ000-200200-

MESOSCALE DISCUSSION 0712
NWS STORM PREDICTION CENTER NORMAN OK
0755 PM CDT SUN MAY 19 2013

AREAS AFFECTED...ERN - NERN - AND N-CNTRL KS / SERN NEB / NWRN MO

CONCERNING...TORNADO WATCH 181...

VALID 200055Z - 200200Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...THE TORNADO THREAT IS SEEMINGLY CONFINED TO THE QLCS ALONG
THE KS/MO BORDER AND OVER SERN KS.

DISCUSSION...SUBJECTIVE SURFACE MESOANALYSIS SHOWS MUCH OF N-CNTRL
AND NERN KS IN A RAIN-COOLED/PARTIAL CONVECTIVELY OVERTURNED AIRMASS
WITH TEMPS IN THE 60S/LOWER 70S.  SOME VIGOR HAS BEEN NOTED ON THE
WRN EDGE OF THE TORNADO WATCH OVER N-CNTRL KS WHERE UPSTREAM
MID-LEVEL LAPSE RATES ARE STILL SUPPORTIVE FOR PERHAPS A LOCALLY
STRONG WIND GUST/MARGINALLY SEVERE HAIL THREAT.

FARTHER E ALONG THE KS/MO BORDER...A QLCS CONTINUES MOVING NEWD
ACROSS PORTIONS OF THE LOWER MO VALLEY.  KEAX RADAR IMAGERY SHOWS
ENHANCED POCKETS OF SEVERE WIND GUSTS IN ASSOCIATION WITH THE QLCS
PASSAGE.  ALTHOUGH THE TORNADO THREAT IS SOMEWHAT LIMITED GIVEN THE
CONVECTIVE MODE...A NON-ZERO TORNADIC MESOVORTEX THREAT IS STILL
POSSIBLE GIVEN THE STRONG LOW LEVEL SHEAR PROFILE OVER THIS REGION.

MORE CELLULAR STORMS HAVE DEVELOPED OVER S-CNTRL KS AND WILL LIKELY
CONTINUE TO INGEST A MOISTURE RICH/UNSTABLE AIRMASS FROM THE S.
STEEP LAPSE RATES WOULD SUPPORT AN ISOLD LARGE HAIL / LOCALLY
DAMAGING WIND THREAT.  A TORNADO OR TWO IS STILL POSSIBLE THIS
EVENING AS THE 50 KT LLJ FOCUSES TOWARDS THIS REGION.

..SMITH.. 05/20/2013

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

ATTN...WFO...DMX...EAX...TSA...OAX...TOP...ICT...OUN...GID...
DDC...

LAT...LON   38249847 39529818 40479759 40909670 40589476 40119395
            38079512 37029576 36939683 37449706 38009608 38529606
            38249847

000
ACUS11 KWNS 200055
SWOMCD
SPC MCD 200055
MOZ000-IAZ000-KSZ000-NEZ000-OKZ000-200200-

MESOSCALE DISCUSSION 0712
NWS STORM PREDICTION CENTER NORMAN OK
0755 PM CDT SUN MAY 19 2013

AREAS AFFECTED...ERN - NERN - AND N-CNTRL KS / SERN NEB / NWRN MO

CONCERNING...TORNADO WATCH 181...

VALID 200055Z - 200200Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...THE TORNADO THREAT IS SEEMINGLY CONFINED TO THE QLCS ALONG
THE KS/MO BORDER AND OVER SERN KS.

DISCUSSION...SUBJECTIVE SURFACE MESOANALYSIS SHOWS MUCH OF N-CNTRL
AND NERN KS IN A RAIN-COOLED/PARTIAL CONVECTIVELY OVERTURNED AIRMASS
WITH TEMPS IN THE 60S/LOWER 70S.  SOME VIGOR HAS BEEN NOTED ON THE
WRN EDGE OF THE TORNADO WATCH OVER N-CNTRL KS WHERE UPSTREAM
MID-LEVEL LAPSE RATES ARE STILL SUPPORTIVE FOR PERHAPS A LOCALLY
STRONG WIND GUST/MARGINALLY SEVERE HAIL THREAT.

FARTHER E ALONG THE KS/MO BORDER...A QLCS CONTINUES MOVING NEWD
ACROSS PORTIONS OF THE LOWER MO VALLEY.  KEAX RADAR IMAGERY SHOWS
ENHANCED POCKETS OF SEVERE WIND GUSTS IN ASSOCIATION WITH THE QLCS
PASSAGE.  ALTHOUGH THE TORNADO THREAT IS SOMEWHAT LIMITED GIVEN THE
CONVECTIVE MODE...A NON-ZERO TORNADIC MESOVORTEX THREAT IS STILL
POSSIBLE GIVEN THE STRONG LOW LEVEL SHEAR PROFILE OVER THIS REGION.

MORE CELLULAR STORMS HAVE DEVELOPED OVER S-CNTRL KS AND WILL LIKELY
CONTINUE TO INGEST A MOISTURE RICH/UNSTABLE AIRMASS FROM THE S.
STEEP LAPSE RATES WOULD SUPPORT AN ISOLD LARGE HAIL / LOCALLY
DAMAGING WIND THREAT.  A TORNADO OR TWO IS STILL POSSIBLE THIS
EVENING AS THE 50 KT LLJ FOCUSES TOWARDS THIS REGION.

..SMITH.. 05/20/2013

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

ATTN...WFO...DMX...EAX...TSA...OAX...TOP...ICT...OUN...GID...
DDC...

LAT...LON   38249847 39529818 40479759 40909670 40589476 40119395
            38079512 37029576 36939683 37449706 38009608 38529606
            38249847

000
ACUS11 KWNS 200047
SWOMCD
SPC MCD 200046
WIZ000-ILZ000-IAZ000-MNZ000-200145-

MESOSCALE DISCUSSION 0711
NWS STORM PREDICTION CENTER NORMAN OK
0746 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN WI INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 200046Z - 200145Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...AN INCREASING SEVERE WEATHER THREAT IS ANTICIPATED TO THE
EAST OF TORNADO WATCHES 180 AND 183 LATE THIS EVENING INTO TONIGHT.
THE PRIMARY HAZARDS WILL BE DAMAGING WINDS AND HAIL...THOUGH A
TORNADO OR TWO WILL BE POSSIBLE  A NEW WATCH WILL LIKELY BE REQUIRED
WITHIN THE HOUR.

DISCUSSION...THE 00Z DVN AND ILX SOUNDINGS SHOWED THAT THE LOCAL
ENVIRONMENT REMAINS MODERATELY UNSTABLE THIS EVENING OWING TO STEEP
LOW TO MIDLEVEL LAPSE RATES AND A MOIST PBL WHERE LOWEST 100-MB
MEAN-MIXING RATIOS OF AROUND 13.5 G/KG WERE OBSERVED.  THOUGH SFC
TEMPERATURES WILL START TO COOL...THE MOIST ENVIRONMENT COUPLED WITH
THE ABSENCE OF ANY APPRECIABLE CAP SHOULD MAINTAIN MODERATE
INSTABILITY INTO THE OVERNIGHT HOURS.  AS SUCH...EXPECT ONGOING
BOWING TSTM COMPLEX OVER NWRN IL TO PERSIST...WITH ADDITIONAL STORMS
DEVELOPING ACROSS DISCUSSION AREA WITHIN THE EXIT REGION OF A 40-50
KT NOCTURNAL LOW-LEVEL WIND MAXIMUM WHERE WAA AND ISENTROPIC ASCENT
WILL BE ENHANCED.  GIVEN A STEADY STRENGTHENING TO THE MID AND
UPPER-TROPOSPHERIC FLOW FIELD...THE ENVIRONMENT WILL BE SUPPORTIVE
OF EMBEDDED SUPERCELL AND BOWING STRUCTURES CAPABLE DAMAGING
WINDS...HAIL...AND PERHAPS A TORNADO OR TWO.

..MEAD/CORFIDI.. 05/20/2013

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

ATTN...WFO...GRB...LOT...ILX...MKX...DVN...ARX...

LAT...LON   41209149 42899142 44019123 44449049 44448946 44108892
            43218874 41818885 41208885 40818957 40889068 41209149

000
ACUS11 KWNS 200047
SWOMCD
SPC MCD 200046
WIZ000-ILZ000-IAZ000-MNZ000-200145-

MESOSCALE DISCUSSION 0711
NWS STORM PREDICTION CENTER NORMAN OK
0746 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN WI INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 200046Z - 200145Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...AN INCREASING SEVERE WEATHER THREAT IS ANTICIPATED TO THE
EAST OF TORNADO WATCHES 180 AND 183 LATE THIS EVENING INTO TONIGHT.
THE PRIMARY HAZARDS WILL BE DAMAGING WINDS AND HAIL...THOUGH A
TORNADO OR TWO WILL BE POSSIBLE  A NEW WATCH WILL LIKELY BE REQUIRED
WITHIN THE HOUR.

DISCUSSION...THE 00Z DVN AND ILX SOUNDINGS SHOWED THAT THE LOCAL
ENVIRONMENT REMAINS MODERATELY UNSTABLE THIS EVENING OWING TO STEEP
LOW TO MIDLEVEL LAPSE RATES AND A MOIST PBL WHERE LOWEST 100-MB
MEAN-MIXING RATIOS OF AROUND 13.5 G/KG WERE OBSERVED.  THOUGH SFC
TEMPERATURES WILL START TO COOL...THE MOIST ENVIRONMENT COUPLED WITH
THE ABSENCE OF ANY APPRECIABLE CAP SHOULD MAINTAIN MODERATE
INSTABILITY INTO THE OVERNIGHT HOURS.  AS SUCH...EXPECT ONGOING
BOWING TSTM COMPLEX OVER NWRN IL TO PERSIST...WITH ADDITIONAL STORMS
DEVELOPING ACROSS DISCUSSION AREA WITHIN THE EXIT REGION OF A 40-50
KT NOCTURNAL LOW-LEVEL WIND MAXIMUM WHERE WAA AND ISENTROPIC ASCENT
WILL BE ENHANCED.  GIVEN A STEADY STRENGTHENING TO THE MID AND
UPPER-TROPOSPHERIC FLOW FIELD...THE ENVIRONMENT WILL BE SUPPORTIVE
OF EMBEDDED SUPERCELL AND BOWING STRUCTURES CAPABLE DAMAGING
WINDS...HAIL...AND PERHAPS A TORNADO OR TWO.

..MEAD/CORFIDI.. 05/20/2013

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

ATTN...WFO...GRB...LOT...ILX...MKX...DVN...ARX...

LAT...LON   41209149 42899142 44019123 44449049 44448946 44108892
            43218874 41818885 41208885 40818957 40889068 41209149

000
ACUS11 KWNS 200047
SWOMCD
SPC MCD 200046
WIZ000-ILZ000-IAZ000-MNZ000-200145-

MESOSCALE DISCUSSION 0711
NWS STORM PREDICTION CENTER NORMAN OK
0746 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN WI INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 200046Z - 200145Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...AN INCREASING SEVERE WEATHER THREAT IS ANTICIPATED TO THE
EAST OF TORNADO WATCHES 180 AND 183 LATE THIS EVENING INTO TONIGHT.
THE PRIMARY HAZARDS WILL BE DAMAGING WINDS AND HAIL...THOUGH A
TORNADO OR TWO WILL BE POSSIBLE  A NEW WATCH WILL LIKELY BE REQUIRED
WITHIN THE HOUR.

DISCUSSION...THE 00Z DVN AND ILX SOUNDINGS SHOWED THAT THE LOCAL
ENVIRONMENT REMAINS MODERATELY UNSTABLE THIS EVENING OWING TO STEEP
LOW TO MIDLEVEL LAPSE RATES AND A MOIST PBL WHERE LOWEST 100-MB
MEAN-MIXING RATIOS OF AROUND 13.5 G/KG WERE OBSERVED.  THOUGH SFC
TEMPERATURES WILL START TO COOL...THE MOIST ENVIRONMENT COUPLED WITH
THE ABSENCE OF ANY APPRECIABLE CAP SHOULD MAINTAIN MODERATE
INSTABILITY INTO THE OVERNIGHT HOURS.  AS SUCH...EXPECT ONGOING
BOWING TSTM COMPLEX OVER NWRN IL TO PERSIST...WITH ADDITIONAL STORMS
DEVELOPING ACROSS DISCUSSION AREA WITHIN THE EXIT REGION OF A 40-50
KT NOCTURNAL LOW-LEVEL WIND MAXIMUM WHERE WAA AND ISENTROPIC ASCENT
WILL BE ENHANCED.  GIVEN A STEADY STRENGTHENING TO THE MID AND
UPPER-TROPOSPHERIC FLOW FIELD...THE ENVIRONMENT WILL BE SUPPORTIVE
OF EMBEDDED SUPERCELL AND BOWING STRUCTURES CAPABLE DAMAGING
WINDS...HAIL...AND PERHAPS A TORNADO OR TWO.

..MEAD/CORFIDI.. 05/20/2013

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

ATTN...WFO...GRB...LOT...ILX...MKX...DVN...ARX...

LAT...LON   41209149 42899142 44019123 44449049 44448946 44108892
            43218874 41818885 41208885 40818957 40889068 41209149

000
ACUS11 KWNS 200014
SWOMCD
SPC MCD 200013
ILZ000-IAZ000-MOZ000-200115-

MESOSCALE DISCUSSION 0710
NWS STORM PREDICTION CENTER NORMAN OK
0713 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN IA

CONCERNING...TORNADO WATCH 183...

VALID 200013Z - 200115Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 183 CONTINUES.

SUMMARY...THE SEVERE WEATHER THREAT CONTINUES ACROSS THE WATCH AREA
WITH THE GREATEST NEAR-TERM RISK FOR TORNADOES...DAMAGING
WINDS...AND HAIL OVER CNTRL IA.

DISCUSSION...A NOTABLE INCREASE IN TSTMS HAS BEEN OBSERVED OVER THE
PAST HOUR BETWEEN OMA AND DSM...LIKELY IN RESPONSE TO THE INFLUENCE
OF A VORTICITY MAXIMUM RAPIDLY MOVING NEWD THROUGH NWRN IA.  AS OF
2355Z...THE MOST INTENSE STORM /A SUPERCELL/ WAS LOCATED OVER DALLAS
COUNTY IA WHICH HAS RECENTLY PRODUCED A TORNADO.  GIVEN A
MOIST...MODERATELY UNSTABLE AIR MASS WHICH COINCIDES WITH A
KINEMATIC ENVIRONMENT FEATURING LARGELY UNIDIRECTIONAL SLY WINDS
THROUGH THE LOWEST 4 KM AGL BEFORE VEERING SLIGHTLY TO SSWLY AND
INCREASING TO 50-60 KT IN THE UPPER TROPOSPHERE...THE THREAT FOR
EMBEDDED SUPERCELL STRUCTURES WILL PERSIST OVER CNTRL IA THIS
EVENING.  WHILE DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY
HAZARDS...ISOLATED TORNADOES WILL BE POSSIBLE WITH THE MOST
INTENSE/PERSISTENT SUPERCELLS.

OVER ERN IA...A CLUSTER OF STRONG TO SEVERE STORMS CONTINUES ALONG
THE MS RIVER NEAR MLI.  WHILE VERTICAL SHEAR IS COMPARATIVELY WEAKER
THAN POINTS TO THE WEST...THE 00Z DVN SOUNDING SUGGESTS THAT
SUFFICIENT INSTABILITY EXISTS TO SUPPORT AT LEAST AN ISOLATED SEVERE
WEATHER THREAT FOR THE NEXT COUPLE OF HOURS.

..MEAD.. 05/20/2013

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

ATTN...WFO...ILX...DVN...DMX...EAX...FSD...OAX...

LAT...LON   42229623 42339029 41549002 40599050 40319093 40439204
            40729316 40629534 41289577 42229623

000
ACUS11 KWNS 200014
SWOMCD
SPC MCD 200013
ILZ000-IAZ000-MOZ000-200115-

MESOSCALE DISCUSSION 0710
NWS STORM PREDICTION CENTER NORMAN OK
0713 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN IA

CONCERNING...TORNADO WATCH 183...

VALID 200013Z - 200115Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 183 CONTINUES.

SUMMARY...THE SEVERE WEATHER THREAT CONTINUES ACROSS THE WATCH AREA
WITH THE GREATEST NEAR-TERM RISK FOR TORNADOES...DAMAGING
WINDS...AND HAIL OVER CNTRL IA.

DISCUSSION...A NOTABLE INCREASE IN TSTMS HAS BEEN OBSERVED OVER THE
PAST HOUR BETWEEN OMA AND DSM...LIKELY IN RESPONSE TO THE INFLUENCE
OF A VORTICITY MAXIMUM RAPIDLY MOVING NEWD THROUGH NWRN IA.  AS OF
2355Z...THE MOST INTENSE STORM /A SUPERCELL/ WAS LOCATED OVER DALLAS
COUNTY IA WHICH HAS RECENTLY PRODUCED A TORNADO.  GIVEN A
MOIST...MODERATELY UNSTABLE AIR MASS WHICH COINCIDES WITH A
KINEMATIC ENVIRONMENT FEATURING LARGELY UNIDIRECTIONAL SLY WINDS
THROUGH THE LOWEST 4 KM AGL BEFORE VEERING SLIGHTLY TO SSWLY AND
INCREASING TO 50-60 KT IN THE UPPER TROPOSPHERE...THE THREAT FOR
EMBEDDED SUPERCELL STRUCTURES WILL PERSIST OVER CNTRL IA THIS
EVENING.  WHILE DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY
HAZARDS...ISOLATED TORNADOES WILL BE POSSIBLE WITH THE MOST
INTENSE/PERSISTENT SUPERCELLS.

OVER ERN IA...A CLUSTER OF STRONG TO SEVERE STORMS CONTINUES ALONG
THE MS RIVER NEAR MLI.  WHILE VERTICAL SHEAR IS COMPARATIVELY WEAKER
THAN POINTS TO THE WEST...THE 00Z DVN SOUNDING SUGGESTS THAT
SUFFICIENT INSTABILITY EXISTS TO SUPPORT AT LEAST AN ISOLATED SEVERE
WEATHER THREAT FOR THE NEXT COUPLE OF HOURS.

..MEAD.. 05/20/2013

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

ATTN...WFO...ILX...DVN...DMX...EAX...FSD...OAX...

LAT...LON   42229623 42339029 41549002 40599050 40319093 40439204
            40729316 40629534 41289577 42229623

000
ACUS11 KWNS 200014
SWOMCD
SPC MCD 200013
ILZ000-IAZ000-MOZ000-200115-

MESOSCALE DISCUSSION 0710
NWS STORM PREDICTION CENTER NORMAN OK
0713 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL AND SRN IA

CONCERNING...TORNADO WATCH 183...

VALID 200013Z - 200115Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 183 CONTINUES.

SUMMARY...THE SEVERE WEATHER THREAT CONTINUES ACROSS THE WATCH AREA
WITH THE GREATEST NEAR-TERM RISK FOR TORNADOES...DAMAGING
WINDS...AND HAIL OVER CNTRL IA.

DISCUSSION...A NOTABLE INCREASE IN TSTMS HAS BEEN OBSERVED OVER THE
PAST HOUR BETWEEN OMA AND DSM...LIKELY IN RESPONSE TO THE INFLUENCE
OF A VORTICITY MAXIMUM RAPIDLY MOVING NEWD THROUGH NWRN IA.  AS OF
2355Z...THE MOST INTENSE STORM /A SUPERCELL/ WAS LOCATED OVER DALLAS
COUNTY IA WHICH HAS RECENTLY PRODUCED A TORNADO.  GIVEN A
MOIST...MODERATELY UNSTABLE AIR MASS WHICH COINCIDES WITH A
KINEMATIC ENVIRONMENT FEATURING LARGELY UNIDIRECTIONAL SLY WINDS
THROUGH THE LOWEST 4 KM AGL BEFORE VEERING SLIGHTLY TO SSWLY AND
INCREASING TO 50-60 KT IN THE UPPER TROPOSPHERE...THE THREAT FOR
EMBEDDED SUPERCELL STRUCTURES WILL PERSIST OVER CNTRL IA THIS
EVENING.  WHILE DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY
HAZARDS...ISOLATED TORNADOES WILL BE POSSIBLE WITH THE MOST
INTENSE/PERSISTENT SUPERCELLS.

OVER ERN IA...A CLUSTER OF STRONG TO SEVERE STORMS CONTINUES ALONG
THE MS RIVER NEAR MLI.  WHILE VERTICAL SHEAR IS COMPARATIVELY WEAKER
THAN POINTS TO THE WEST...THE 00Z DVN SOUNDING SUGGESTS THAT
SUFFICIENT INSTABILITY EXISTS TO SUPPORT AT LEAST AN ISOLATED SEVERE
WEATHER THREAT FOR THE NEXT COUPLE OF HOURS.

..MEAD.. 05/20/2013

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

ATTN...WFO...ILX...DVN...DMX...EAX...FSD...OAX...

LAT...LON   42229623 42339029 41549002 40599050 40319093 40439204
            40729316 40629534 41289577 42229623

000
ACUS11 KWNS 192327
SWOMCD
SPC MCD 192327
OKZ000-KSZ000-200030-

MESOSCALE DISCUSSION 0709
NWS STORM PREDICTION CENTER NORMAN OK
0627 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN KS / NERN AND CNTRL OK

CONCERNING...TORNADO WATCH 181...182...

VALID 192327Z - 200030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181...182...CONTINUES.

SUMMARY...INTENSE TORNADO THREAT WILL CONTINUE OVER CNTRL OK
EXTENDING NEWD INTO NERN OK AND SERN KS.

DISCUSSION...RADAR MOSAIC SHOWS SEVERAL DISCRETE SUPERCELLS FROM
SERN KS ON THE SRN END OF A SQUALL LINE WITH ANOTHER CLUSTER OF
DISCRETE SUPERCELLS FROM 35 MI W OF TUL...5 NNW CQB...AND 25 ESE OF
OKC.  KTLX VWP SHOWED A PRONOUNCED SICKLE SHAPED HODOGRAPH /350
M2/S2 0-1 KM SRH/ WITH A MARKED INCREASE IN LOW LEVEL SHEAR PRIOR TO
THE PASSAGE OF THE NOW CONFIRMED TORNADIC SUPERCELL.  VERY INTENSE
ROTATIONAL VELOCITIES WITH THE CLEVELAND COUNTY/POTTAWATOMIE COUNTY
STORM...COMBINED WITH A FAVORABLE CONVECTIVE MODE AND NEAR-STORM
ENVIRONMENT...WILL LIKELY YIELD A HIGH PROBABILITY FOR CONTINUED
CYCLING OF INTENSE TORNADOES DOWNSTREAM OF THIS STORM.  THE 105 KT
ROTATIONAL VELOCITY AT 0.5 DEG AS OF 2320Z...IS HIGHLY INDICATIVE OF
A VERY INTENSE/POTENTIALLY VIOLENT TORNADO WITH THIS STORM.

FARTHER NE OVER NERN OK...KINX VWP SHOWS 50 KT SLY FLOW AT 1 KM AGL.
ALTHOUGH THE HODOGRAPH STRUCTURE IS NOT AS IMPRESSIVE AS KTLX...300
M2/S2 0-1 KM SRH WILL MORE THAN SUPPORT THE THREAT FOR LONG-LIVED
SUPERCELLS CAPABLE OF DAMAGING TORNADOES.

..SMITH.. 05/19/2013

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

ATTN...WFO...TSA...ICT...OUN...

LAT...LON   37389685 36819737 35309742 35239675 35289634 36089577
            37159576 37489617 37389685

000
ACUS11 KWNS 192327
SWOMCD
SPC MCD 192327
OKZ000-KSZ000-200030-

MESOSCALE DISCUSSION 0709
NWS STORM PREDICTION CENTER NORMAN OK
0627 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN KS / NERN AND CNTRL OK

CONCERNING...TORNADO WATCH 181...182...

VALID 192327Z - 200030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181...182...CONTINUES.

SUMMARY...INTENSE TORNADO THREAT WILL CONTINUE OVER CNTRL OK
EXTENDING NEWD INTO NERN OK AND SERN KS.

DISCUSSION...RADAR MOSAIC SHOWS SEVERAL DISCRETE SUPERCELLS FROM
SERN KS ON THE SRN END OF A SQUALL LINE WITH ANOTHER CLUSTER OF
DISCRETE SUPERCELLS FROM 35 MI W OF TUL...5 NNW CQB...AND 25 ESE OF
OKC.  KTLX VWP SHOWED A PRONOUNCED SICKLE SHAPED HODOGRAPH /350
M2/S2 0-1 KM SRH/ WITH A MARKED INCREASE IN LOW LEVEL SHEAR PRIOR TO
THE PASSAGE OF THE NOW CONFIRMED TORNADIC SUPERCELL.  VERY INTENSE
ROTATIONAL VELOCITIES WITH THE CLEVELAND COUNTY/POTTAWATOMIE COUNTY
STORM...COMBINED WITH A FAVORABLE CONVECTIVE MODE AND NEAR-STORM
ENVIRONMENT...WILL LIKELY YIELD A HIGH PROBABILITY FOR CONTINUED
CYCLING OF INTENSE TORNADOES DOWNSTREAM OF THIS STORM.  THE 105 KT
ROTATIONAL VELOCITY AT 0.5 DEG AS OF 2320Z...IS HIGHLY INDICATIVE OF
A VERY INTENSE/POTENTIALLY VIOLENT TORNADO WITH THIS STORM.

FARTHER NE OVER NERN OK...KINX VWP SHOWS 50 KT SLY FLOW AT 1 KM AGL.
ALTHOUGH THE HODOGRAPH STRUCTURE IS NOT AS IMPRESSIVE AS KTLX...300
M2/S2 0-1 KM SRH WILL MORE THAN SUPPORT THE THREAT FOR LONG-LIVED
SUPERCELLS CAPABLE OF DAMAGING TORNADOES.

..SMITH.. 05/19/2013

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

ATTN...WFO...TSA...ICT...OUN...

LAT...LON   37389685 36819737 35309742 35239675 35289634 36089577
            37159576 37489617 37389685

000
ACUS11 KWNS 192327
SWOMCD
SPC MCD 192327
OKZ000-KSZ000-200030-

MESOSCALE DISCUSSION 0709
NWS STORM PREDICTION CENTER NORMAN OK
0627 PM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN KS / NERN AND CNTRL OK

CONCERNING...TORNADO WATCH 181...182...

VALID 192327Z - 200030Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181...182...CONTINUES.

SUMMARY...INTENSE TORNADO THREAT WILL CONTINUE OVER CNTRL OK
EXTENDING NEWD INTO NERN OK AND SERN KS.

DISCUSSION...RADAR MOSAIC SHOWS SEVERAL DISCRETE SUPERCELLS FROM
SERN KS ON THE SRN END OF A SQUALL LINE WITH ANOTHER CLUSTER OF
DISCRETE SUPERCELLS FROM 35 MI W OF TUL...5 NNW CQB...AND 25 ESE OF
OKC.  KTLX VWP SHOWED A PRONOUNCED SICKLE SHAPED HODOGRAPH /350
M2/S2 0-1 KM SRH/ WITH A MARKED INCREASE IN LOW LEVEL SHEAR PRIOR TO
THE PASSAGE OF THE NOW CONFIRMED TORNADIC SUPERCELL.  VERY INTENSE
ROTATIONAL VELOCITIES WITH THE CLEVELAND COUNTY/POTTAWATOMIE COUNTY
STORM...COMBINED WITH A FAVORABLE CONVECTIVE MODE AND NEAR-STORM
ENVIRONMENT...WILL LIKELY YIELD A HIGH PROBABILITY FOR CONTINUED
CYCLING OF INTENSE TORNADOES DOWNSTREAM OF THIS STORM.  THE 105 KT
ROTATIONAL VELOCITY AT 0.5 DEG AS OF 2320Z...IS HIGHLY INDICATIVE OF
A VERY INTENSE/POTENTIALLY VIOLENT TORNADO WITH THIS STORM.

FARTHER NE OVER NERN OK...KINX VWP SHOWS 50 KT SLY FLOW AT 1 KM AGL.
ALTHOUGH THE HODOGRAPH STRUCTURE IS NOT AS IMPRESSIVE AS KTLX...300
M2/S2 0-1 KM SRH WILL MORE THAN SUPPORT THE THREAT FOR LONG-LIVED
SUPERCELLS CAPABLE OF DAMAGING TORNADOES.

..SMITH.. 05/19/2013

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

ATTN...WFO...TSA...ICT...OUN...

LAT...LON   37389685 36819737 35309742 35239675 35289634 36089577
            37159576 37489617 37389685

000
ACUS11 KWNS 192309
SWOMCD
SPC MCD 192308
ILZ000-200015-

MESOSCALE DISCUSSION 0708
NWS STORM PREDICTION CENTER NORMAN OK
0608 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 192308Z - 200015Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTMS INTENSIFYING ALONG THE MS RIVER BETWEEN MLI AND UIN
MAY MOVE OUT OF TORNADO WATCH 183 PRIOR TO 00Z.  CONVECTIVE TRENDS
ARE BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...AS OF 2245Z...RADAR DATA INDICATED A CLUSTER OF
INTENSIFYING TSTMS FROM ROCK ISLAND AND MERCER COUNTIES TO HANCOCK
COUNTY IL.  THE ANCHOR STORM OF THIS CLUSTER OVER HANCOCK COUNTY HAS
RECENTLY EXHIBITED RIGHTWARD PROPAGATION...SUGGESTING EVOLUTION INTO
A SUPERCELL.  AREA VAD DATA AND MODEL-DERIVED FORECAST SOUNDINGS
INDICATE A ENVIRONMENT FOR UPDRAFT SUSTENANCE/ROTATION WITH A
MODERATELY UNSTABLE AIR MASS WHICH COINCIDES WITH A VERTICALLY
VEERING WIND PROFILE AND 40-45 KT OF DEEP-LAYER SHEAR.  EXPECT
VERTICAL SHEAR TO FURTHER STRENGTHEN THROUGH THIS EVENING AS THE
EXIT REGION OF A 40-50 KT LLJ DEVELOPS NEWD INTO THE REGION.  AS
SUCH...EXPECT THE POTENTIAL FOR ORGANIZED STORM MODES...INCLUDING
SUPERCELLS TO PERSIST THROUGH THIS EVENING AND POSSIBLY DEVELOP EAST
OF TORNADO WATCH 183 BY 00Z.

..MEAD/CORFIDI.. 05/19/2013

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

ATTN...WFO...LOT...ILX...DVN...

LAT...LON   40899030 41498963 41838940 41708887 41218890 40478936
            40248995 40399033 40899030

000
ACUS11 KWNS 192309
SWOMCD
SPC MCD 192308
ILZ000-200015-

MESOSCALE DISCUSSION 0708
NWS STORM PREDICTION CENTER NORMAN OK
0608 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 192308Z - 200015Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTMS INTENSIFYING ALONG THE MS RIVER BETWEEN MLI AND UIN
MAY MOVE OUT OF TORNADO WATCH 183 PRIOR TO 00Z.  CONVECTIVE TRENDS
ARE BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...AS OF 2245Z...RADAR DATA INDICATED A CLUSTER OF
INTENSIFYING TSTMS FROM ROCK ISLAND AND MERCER COUNTIES TO HANCOCK
COUNTY IL.  THE ANCHOR STORM OF THIS CLUSTER OVER HANCOCK COUNTY HAS
RECENTLY EXHIBITED RIGHTWARD PROPAGATION...SUGGESTING EVOLUTION INTO
A SUPERCELL.  AREA VAD DATA AND MODEL-DERIVED FORECAST SOUNDINGS
INDICATE A ENVIRONMENT FOR UPDRAFT SUSTENANCE/ROTATION WITH A
MODERATELY UNSTABLE AIR MASS WHICH COINCIDES WITH A VERTICALLY
VEERING WIND PROFILE AND 40-45 KT OF DEEP-LAYER SHEAR.  EXPECT
VERTICAL SHEAR TO FURTHER STRENGTHEN THROUGH THIS EVENING AS THE
EXIT REGION OF A 40-50 KT LLJ DEVELOPS NEWD INTO THE REGION.  AS
SUCH...EXPECT THE POTENTIAL FOR ORGANIZED STORM MODES...INCLUDING
SUPERCELLS TO PERSIST THROUGH THIS EVENING AND POSSIBLY DEVELOP EAST
OF TORNADO WATCH 183 BY 00Z.

..MEAD/CORFIDI.. 05/19/2013

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

ATTN...WFO...LOT...ILX...DVN...

LAT...LON   40899030 41498963 41838940 41708887 41218890 40478936
            40248995 40399033 40899030

000
ACUS11 KWNS 192309
SWOMCD
SPC MCD 192308
ILZ000-200015-

MESOSCALE DISCUSSION 0708
NWS STORM PREDICTION CENTER NORMAN OK
0608 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL INTO NRN IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 192308Z - 200015Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTMS INTENSIFYING ALONG THE MS RIVER BETWEEN MLI AND UIN
MAY MOVE OUT OF TORNADO WATCH 183 PRIOR TO 00Z.  CONVECTIVE TRENDS
ARE BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...AS OF 2245Z...RADAR DATA INDICATED A CLUSTER OF
INTENSIFYING TSTMS FROM ROCK ISLAND AND MERCER COUNTIES TO HANCOCK
COUNTY IL.  THE ANCHOR STORM OF THIS CLUSTER OVER HANCOCK COUNTY HAS
RECENTLY EXHIBITED RIGHTWARD PROPAGATION...SUGGESTING EVOLUTION INTO
A SUPERCELL.  AREA VAD DATA AND MODEL-DERIVED FORECAST SOUNDINGS
INDICATE A ENVIRONMENT FOR UPDRAFT SUSTENANCE/ROTATION WITH A
MODERATELY UNSTABLE AIR MASS WHICH COINCIDES WITH A VERTICALLY
VEERING WIND PROFILE AND 40-45 KT OF DEEP-LAYER SHEAR.  EXPECT
VERTICAL SHEAR TO FURTHER STRENGTHEN THROUGH THIS EVENING AS THE
EXIT REGION OF A 40-50 KT LLJ DEVELOPS NEWD INTO THE REGION.  AS
SUCH...EXPECT THE POTENTIAL FOR ORGANIZED STORM MODES...INCLUDING
SUPERCELLS TO PERSIST THROUGH THIS EVENING AND POSSIBLY DEVELOP EAST
OF TORNADO WATCH 183 BY 00Z.

..MEAD/CORFIDI.. 05/19/2013

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

ATTN...WFO...LOT...ILX...DVN...

LAT...LON   40899030 41498963 41838940 41708887 41218890 40478936
            40248995 40399033 40899030

000
ACUS11 KWNS 192255
SWOMCD
SPC MCD 192254
MOZ000-OKZ000-KSZ000-200000-

MESOSCALE DISCUSSION 0707
NWS STORM PREDICTION CENTER NORMAN OK
0554 PM CDT SUN MAY 19 2013

AREAS AFFECTED...FAR SERN KS / SWRN-CNTRL-NERN MO

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 192254Z - 200000Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A TORNADO WATCH WILL NEED TO BE ISSUED OVER THE NEXT HR OR
SO DOWNSTREAM OF THE EXISTING TORNADO WATCHES FOR PARTS OF FAR SERN
KS AND SWRN MO NEWD INTO NERN MO.

DISCUSSION...THE AIRMASS OVER MUCH OF MO IS MODERATELY UNSTABLE PER
THE 20Z SGF RAOB /1600 J/KG MLCAPE/.  THE LOW LEVEL WIND PROFILE IS
FORECAST TO STRENGTHEN AS THE LLJ INTENSIFIES THIS EVENING /50+ KT/
AND BECOME FAVORABLE FOR LOW LEVEL MESOCYCLONES/MESOVORTICES.
DESPITE SOME DECREASE OF DEWPOINTS NOTED OVER SWRN MO INTO THE LOWER
60S DUE TO MIXING DURING THE PAST FEW HOURS...LOW LEVEL MOIST
ADVECTION SHOULD YIELD AN INCREASINGLY MOIST BOUNDARY LAYER BY THIS
EVENING.  IT IS UNCERTAIN WHETHER MID LEVEL CONVECTION ALONG THE
KS/MO BORDER CAN ROOT IN THE BOUNDARY LAYER IN THE NEAR-TERM.  IF
THIS OCCURS...A TORNADO WATCH MAY BE NEEDED SOON.  OTHERWISE...A
TORNADO WATCH WILL LIKELY BE ISSUED ONCE STORMS OVER E-CNTRL KS MOVE
INTO CLOSER PROXIMITY THE MO/KS BORDER.  IN ADDITION TO A TORNADO
THREAT...SWATHS OF DMGG WINDS /POTENTIALLY SIGNIFICANT/ WILL LIKELY
BE THE MORE WIDESPREAD THREAT AS STORMS GROW UPSCALE THIS
EVENING/TONIGHT.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...LSX...DVN...SGF...EAX...TSA...ICT...

LAT...LON   37059508 40439345 40409199 39889151 38389179 36609288
            36569436 37059508

000
ACUS11 KWNS 192255
SWOMCD
SPC MCD 192254
MOZ000-OKZ000-KSZ000-200000-

MESOSCALE DISCUSSION 0707
NWS STORM PREDICTION CENTER NORMAN OK
0554 PM CDT SUN MAY 19 2013

AREAS AFFECTED...FAR SERN KS / SWRN-CNTRL-NERN MO

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 192254Z - 200000Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A TORNADO WATCH WILL NEED TO BE ISSUED OVER THE NEXT HR OR
SO DOWNSTREAM OF THE EXISTING TORNADO WATCHES FOR PARTS OF FAR SERN
KS AND SWRN MO NEWD INTO NERN MO.

DISCUSSION...THE AIRMASS OVER MUCH OF MO IS MODERATELY UNSTABLE PER
THE 20Z SGF RAOB /1600 J/KG MLCAPE/.  THE LOW LEVEL WIND PROFILE IS
FORECAST TO STRENGTHEN AS THE LLJ INTENSIFIES THIS EVENING /50+ KT/
AND BECOME FAVORABLE FOR LOW LEVEL MESOCYCLONES/MESOVORTICES.
DESPITE SOME DECREASE OF DEWPOINTS NOTED OVER SWRN MO INTO THE LOWER
60S DUE TO MIXING DURING THE PAST FEW HOURS...LOW LEVEL MOIST
ADVECTION SHOULD YIELD AN INCREASINGLY MOIST BOUNDARY LAYER BY THIS
EVENING.  IT IS UNCERTAIN WHETHER MID LEVEL CONVECTION ALONG THE
KS/MO BORDER CAN ROOT IN THE BOUNDARY LAYER IN THE NEAR-TERM.  IF
THIS OCCURS...A TORNADO WATCH MAY BE NEEDED SOON.  OTHERWISE...A
TORNADO WATCH WILL LIKELY BE ISSUED ONCE STORMS OVER E-CNTRL KS MOVE
INTO CLOSER PROXIMITY THE MO/KS BORDER.  IN ADDITION TO A TORNADO
THREAT...SWATHS OF DMGG WINDS /POTENTIALLY SIGNIFICANT/ WILL LIKELY
BE THE MORE WIDESPREAD THREAT AS STORMS GROW UPSCALE THIS
EVENING/TONIGHT.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...LSX...DVN...SGF...EAX...TSA...ICT...

LAT...LON   37059508 40439345 40409199 39889151 38389179 36609288
            36569436 37059508

000
ACUS11 KWNS 192255
SWOMCD
SPC MCD 192254
MOZ000-OKZ000-KSZ000-200000-

MESOSCALE DISCUSSION 0707
NWS STORM PREDICTION CENTER NORMAN OK
0554 PM CDT SUN MAY 19 2013

AREAS AFFECTED...FAR SERN KS / SWRN-CNTRL-NERN MO

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

VALID 192254Z - 200000Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A TORNADO WATCH WILL NEED TO BE ISSUED OVER THE NEXT HR OR
SO DOWNSTREAM OF THE EXISTING TORNADO WATCHES FOR PARTS OF FAR SERN
KS AND SWRN MO NEWD INTO NERN MO.

DISCUSSION...THE AIRMASS OVER MUCH OF MO IS MODERATELY UNSTABLE PER
THE 20Z SGF RAOB /1600 J/KG MLCAPE/.  THE LOW LEVEL WIND PROFILE IS
FORECAST TO STRENGTHEN AS THE LLJ INTENSIFIES THIS EVENING /50+ KT/
AND BECOME FAVORABLE FOR LOW LEVEL MESOCYCLONES/MESOVORTICES.
DESPITE SOME DECREASE OF DEWPOINTS NOTED OVER SWRN MO INTO THE LOWER
60S DUE TO MIXING DURING THE PAST FEW HOURS...LOW LEVEL MOIST
ADVECTION SHOULD YIELD AN INCREASINGLY MOIST BOUNDARY LAYER BY THIS
EVENING.  IT IS UNCERTAIN WHETHER MID LEVEL CONVECTION ALONG THE
KS/MO BORDER CAN ROOT IN THE BOUNDARY LAYER IN THE NEAR-TERM.  IF
THIS OCCURS...A TORNADO WATCH MAY BE NEEDED SOON.  OTHERWISE...A
TORNADO WATCH WILL LIKELY BE ISSUED ONCE STORMS OVER E-CNTRL KS MOVE
INTO CLOSER PROXIMITY THE MO/KS BORDER.  IN ADDITION TO A TORNADO
THREAT...SWATHS OF DMGG WINDS /POTENTIALLY SIGNIFICANT/ WILL LIKELY
BE THE MORE WIDESPREAD THREAT AS STORMS GROW UPSCALE THIS
EVENING/TONIGHT.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...LSX...DVN...SGF...EAX...TSA...ICT...

LAT...LON   37059508 40439345 40409199 39889151 38389179 36609288
            36569436 37059508

000
ACUS11 KWNS 192208
SWOMCD
SPC MCD 192208
OKZ000-192245-

MESOSCALE DISCUSSION 0706
NWS STORM PREDICTION CENTER NORMAN OK
0508 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL OK

CONCERNING...TORNADO WATCH 182...

VALID 192208Z - 192245Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 182 CONTINUES.

SUMMARY...HIGH-END LONG TRACK TORNADO WILL LIKELY CONTINUE NEWD
ALONG THE I-44 CORRIDOR FROM LINCOLN COUNTY AND EVENTUALLY THREATEN
CREEK COUNTY.

DISCUSSION...KTLX RADAR STORM VELOCITY DATA SHOWS A HIGH CONFIDENCE
INTENSE TORNADO MOVING INTO LINCOLN COUNTY OKLAHOMA WITH 0.5 DEG
ROTATIONAL VELOCITIES 80-90 KTS.  THE PURCELL WIND PROFILE AND KTLX
SHOW A SICKLE-SHAPE HODOGRAPH.  GIVEN THE VERY BUOYANT AND MOIST
BOUNDARY LAYER...STRONG TO POTENTIALLY VIOLENT TORNADOES MAY
CONTINUE TO AFFECT CNTRL OK OVER THE NEXT FEW HOURS.  AS THE STORMS
FARTHER SOUTH MATURE...POTENTIALLY STRONG TORNADOES MAY EVENTUALLY
EVOLVE FROM THOSE DISCRETE SUPERCELLS.

..SMITH.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   35109780 35899721 36209626 35969605 35359657 35109714
            35109780

000
ACUS11 KWNS 192208
SWOMCD
SPC MCD 192208
OKZ000-192245-

MESOSCALE DISCUSSION 0706
NWS STORM PREDICTION CENTER NORMAN OK
0508 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL OK

CONCERNING...TORNADO WATCH 182...

VALID 192208Z - 192245Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 182 CONTINUES.

SUMMARY...HIGH-END LONG TRACK TORNADO WILL LIKELY CONTINUE NEWD
ALONG THE I-44 CORRIDOR FROM LINCOLN COUNTY AND EVENTUALLY THREATEN
CREEK COUNTY.

DISCUSSION...KTLX RADAR STORM VELOCITY DATA SHOWS A HIGH CONFIDENCE
INTENSE TORNADO MOVING INTO LINCOLN COUNTY OKLAHOMA WITH 0.5 DEG
ROTATIONAL VELOCITIES 80-90 KTS.  THE PURCELL WIND PROFILE AND KTLX
SHOW A SICKLE-SHAPE HODOGRAPH.  GIVEN THE VERY BUOYANT AND MOIST
BOUNDARY LAYER...STRONG TO POTENTIALLY VIOLENT TORNADOES MAY
CONTINUE TO AFFECT CNTRL OK OVER THE NEXT FEW HOURS.  AS THE STORMS
FARTHER SOUTH MATURE...POTENTIALLY STRONG TORNADOES MAY EVENTUALLY
EVOLVE FROM THOSE DISCRETE SUPERCELLS.

..SMITH.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   35109780 35899721 36209626 35969605 35359657 35109714
            35109780

000
ACUS11 KWNS 192205
SWOMCD
SPC MCD 192204
ILZ000-WIZ000-IAZ000-MNZ000-SDZ000-192300-

MESOSCALE DISCUSSION 0705
NWS STORM PREDICTION CENTER NORMAN OK
0504 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MN / WRN WI / NRN IA

CONCERNING...TORNADO WATCH 180...

VALID 192204Z - 192300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 180 CONTINUES.

SUMMARY...THE THREAT FOR LARGE HAIL...DAMAGING WINDS...AND A TORNADO
OR TWO CONTINUES.  THIS THREAT MAY DEVELOP TO THE NORTH OF THE WATCH
AREA BY 23Z...POSSIBLY REQUIRING AN ADDITIONAL WW.

DISCUSSION...AS OF 2150Z...REGIONAL RADAR DATA SHOWED AN ARCING BAND
OF TSTMS FROM SCOTT AND DAKOTA COUNTIES IN E-CNTRL MN TO MITCHELL
COUNTY IA WITH THIS ACTIVITY WELL CORRELATED WITH A MIDLEVEL
VORTICITY MAXIMUM AND A NW-SE ORIENTED SFC CONFLUENCE AXIS.  LATEST
MODEL GUIDANCE INDICATES THAT A 50-70 KT MIDLEVEL JET STREAK WILL
DEVELOP NWD THROUGH WRN WI THIS EVENING...IN CONJUNCTION WITH
STRENGTHENING SLY FLOW IN THE 850-700-MB LAYER.  THIS WILL ENHANCE
VERTICAL SHEAR AND THE NWD FLUX OF AN INCREASINGLY MOIST AND
UNSTABLE AIR MASS.  AS SUCH...EXPECT THE SEVERE WEATHER THREAT TO
CONTINUE WITH THE PRIMARY HAZARDS BEING DAMAGING WINDS AND A FEW
TORNADOES.

..MEAD.. 05/19/2013

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

ATTN...WFO...DVN...DLH...ARX...MPX...DMX...FGF...FSD...ABR...

LAT...LON   42149428 42709522 43979612 45189669 45999632 46639485
            46489242 45389122 43469089 42489060 42159124 42149428

000
ACUS11 KWNS 192205
SWOMCD
SPC MCD 192204
ILZ000-WIZ000-IAZ000-MNZ000-SDZ000-192300-

MESOSCALE DISCUSSION 0705
NWS STORM PREDICTION CENTER NORMAN OK
0504 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MN / WRN WI / NRN IA

CONCERNING...TORNADO WATCH 180...

VALID 192204Z - 192300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 180 CONTINUES.

SUMMARY...THE THREAT FOR LARGE HAIL...DAMAGING WINDS...AND A TORNADO
OR TWO CONTINUES.  THIS THREAT MAY DEVELOP TO THE NORTH OF THE WATCH
AREA BY 23Z...POSSIBLY REQUIRING AN ADDITIONAL WW.

DISCUSSION...AS OF 2150Z...REGIONAL RADAR DATA SHOWED AN ARCING BAND
OF TSTMS FROM SCOTT AND DAKOTA COUNTIES IN E-CNTRL MN TO MITCHELL
COUNTY IA WITH THIS ACTIVITY WELL CORRELATED WITH A MIDLEVEL
VORTICITY MAXIMUM AND A NW-SE ORIENTED SFC CONFLUENCE AXIS.  LATEST
MODEL GUIDANCE INDICATES THAT A 50-70 KT MIDLEVEL JET STREAK WILL
DEVELOP NWD THROUGH WRN WI THIS EVENING...IN CONJUNCTION WITH
STRENGTHENING SLY FLOW IN THE 850-700-MB LAYER.  THIS WILL ENHANCE
VERTICAL SHEAR AND THE NWD FLUX OF AN INCREASINGLY MOIST AND
UNSTABLE AIR MASS.  AS SUCH...EXPECT THE SEVERE WEATHER THREAT TO
CONTINUE WITH THE PRIMARY HAZARDS BEING DAMAGING WINDS AND A FEW
TORNADOES.

..MEAD.. 05/19/2013

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

ATTN...WFO...DVN...DLH...ARX...MPX...DMX...FGF...FSD...ABR...

LAT...LON   42149428 42709522 43979612 45189669 45999632 46639485
            46489242 45389122 43469089 42489060 42159124 42149428

000
ACUS11 KWNS 192205
SWOMCD
SPC MCD 192204
ILZ000-WIZ000-IAZ000-MNZ000-SDZ000-192300-

MESOSCALE DISCUSSION 0705
NWS STORM PREDICTION CENTER NORMAN OK
0504 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MN / WRN WI / NRN IA

CONCERNING...TORNADO WATCH 180...

VALID 192204Z - 192300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 180 CONTINUES.

SUMMARY...THE THREAT FOR LARGE HAIL...DAMAGING WINDS...AND A TORNADO
OR TWO CONTINUES.  THIS THREAT MAY DEVELOP TO THE NORTH OF THE WATCH
AREA BY 23Z...POSSIBLY REQUIRING AN ADDITIONAL WW.

DISCUSSION...AS OF 2150Z...REGIONAL RADAR DATA SHOWED AN ARCING BAND
OF TSTMS FROM SCOTT AND DAKOTA COUNTIES IN E-CNTRL MN TO MITCHELL
COUNTY IA WITH THIS ACTIVITY WELL CORRELATED WITH A MIDLEVEL
VORTICITY MAXIMUM AND A NW-SE ORIENTED SFC CONFLUENCE AXIS.  LATEST
MODEL GUIDANCE INDICATES THAT A 50-70 KT MIDLEVEL JET STREAK WILL
DEVELOP NWD THROUGH WRN WI THIS EVENING...IN CONJUNCTION WITH
STRENGTHENING SLY FLOW IN THE 850-700-MB LAYER.  THIS WILL ENHANCE
VERTICAL SHEAR AND THE NWD FLUX OF AN INCREASINGLY MOIST AND
UNSTABLE AIR MASS.  AS SUCH...EXPECT THE SEVERE WEATHER THREAT TO
CONTINUE WITH THE PRIMARY HAZARDS BEING DAMAGING WINDS AND A FEW
TORNADOES.

..MEAD.. 05/19/2013

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

ATTN...WFO...DVN...DLH...ARX...MPX...DMX...FGF...FSD...ABR...

LAT...LON   42149428 42709522 43979612 45189669 45999632 46639485
            46489242 45389122 43469089 42489060 42159124 42149428

000
ACUS11 KWNS 192158
SWOMCD
SPC MCD 192157
MOZ000-KSZ000-192300-

MESOSCALE DISCUSSION 0704
NWS STORM PREDICTION CENTER NORMAN OK
0457 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-ERN KS

CONCERNING...TORNADO WATCH 181...

VALID 192157Z - 192300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...DMGG WIND POTENTIAL WILL LIKELY INCREASE IN THE AREAS
DOWNSTREAM OVER THE ONGOING SEVERE SQUALL LINE WITH EMBEDDED
SUPERCELLS.  TORNADOES AND LARGE HAIL WILL ALSO REMAIN POSSIBLE.

DISCUSSION...RADAR MOSAIC OVER THE PAST HOUR HAS SHOWN A RAPID
UPTICK IN STORM COVERAGE OVER S-CNTRL KS NEWD INTO NERN KS.  AS
STORMS CONTINUE TO GROW UPSCALE ALONG THE I-35 CORRIDOR OVER THE
NEXT 1-2 HRS...DMGG WIND POTENTIAL WILL LIKELY INCREASE OVER THIS
AREA...EVENTUALLY AFFECTING THE KANSAS CITY METRO AREA BY 00-01Z.
AS LOW LEVEL WINDS INTENSIFY BY EVENING OWING TO AN INCREASE IN THE
LLJ...SWATHS OF LOCALIZED SIGNIFICANT WIND DAMAGE WILL BE POSSIBLE
WITH ANY BOWING SEGMENT/EMBEDDED MESOCYCLONE/MESOVORTEX.

..SMITH.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   37049732 37539730 38289681 38749711 39769650 39789535
            39089453 38249485 37029600 37049732

000
ACUS11 KWNS 192158
SWOMCD
SPC MCD 192157
MOZ000-KSZ000-192300-

MESOSCALE DISCUSSION 0704
NWS STORM PREDICTION CENTER NORMAN OK
0457 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-ERN KS

CONCERNING...TORNADO WATCH 181...

VALID 192157Z - 192300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...DMGG WIND POTENTIAL WILL LIKELY INCREASE IN THE AREAS
DOWNSTREAM OVER THE ONGOING SEVERE SQUALL LINE WITH EMBEDDED
SUPERCELLS.  TORNADOES AND LARGE HAIL WILL ALSO REMAIN POSSIBLE.

DISCUSSION...RADAR MOSAIC OVER THE PAST HOUR HAS SHOWN A RAPID
UPTICK IN STORM COVERAGE OVER S-CNTRL KS NEWD INTO NERN KS.  AS
STORMS CONTINUE TO GROW UPSCALE ALONG THE I-35 CORRIDOR OVER THE
NEXT 1-2 HRS...DMGG WIND POTENTIAL WILL LIKELY INCREASE OVER THIS
AREA...EVENTUALLY AFFECTING THE KANSAS CITY METRO AREA BY 00-01Z.
AS LOW LEVEL WINDS INTENSIFY BY EVENING OWING TO AN INCREASE IN THE
LLJ...SWATHS OF LOCALIZED SIGNIFICANT WIND DAMAGE WILL BE POSSIBLE
WITH ANY BOWING SEGMENT/EMBEDDED MESOCYCLONE/MESOVORTEX.

..SMITH.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   37049732 37539730 38289681 38749711 39769650 39789535
            39089453 38249485 37029600 37049732

000
ACUS11 KWNS 192158
SWOMCD
SPC MCD 192157
MOZ000-KSZ000-192300-

MESOSCALE DISCUSSION 0704
NWS STORM PREDICTION CENTER NORMAN OK
0457 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL-ERN KS

CONCERNING...TORNADO WATCH 181...

VALID 192157Z - 192300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 181 CONTINUES.

SUMMARY...DMGG WIND POTENTIAL WILL LIKELY INCREASE IN THE AREAS
DOWNSTREAM OVER THE ONGOING SEVERE SQUALL LINE WITH EMBEDDED
SUPERCELLS.  TORNADOES AND LARGE HAIL WILL ALSO REMAIN POSSIBLE.

DISCUSSION...RADAR MOSAIC OVER THE PAST HOUR HAS SHOWN A RAPID
UPTICK IN STORM COVERAGE OVER S-CNTRL KS NEWD INTO NERN KS.  AS
STORMS CONTINUE TO GROW UPSCALE ALONG THE I-35 CORRIDOR OVER THE
NEXT 1-2 HRS...DMGG WIND POTENTIAL WILL LIKELY INCREASE OVER THIS
AREA...EVENTUALLY AFFECTING THE KANSAS CITY METRO AREA BY 00-01Z.
AS LOW LEVEL WINDS INTENSIFY BY EVENING OWING TO AN INCREASE IN THE
LLJ...SWATHS OF LOCALIZED SIGNIFICANT WIND DAMAGE WILL BE POSSIBLE
WITH ANY BOWING SEGMENT/EMBEDDED MESOCYCLONE/MESOVORTEX.

..SMITH.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   37049732 37539730 38289681 38749711 39769650 39789535
            39089453 38249485 37029600 37049732

000
ACUS11 KWNS 192138
SWOMCD
SPC MCD 192137
OKZ000-192230-

MESOSCALE DISCUSSION 0703
NWS STORM PREDICTION CENTER NORMAN OK
0437 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL OK

CONCERNING...TORNADO WATCH 182...

VALID 192137Z - 192230Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 182 CONTINUES.

SUMMARY...SUPERCELL TORNADO POTENTIAL WILL CONTINUE TO MARKEDLY
INCREASE ACROSS CNTRL OK OVER THE NEXT HOUR AS THE LOW LEVEL WIND
PROFILE HAS INTENSIFIED SOME DURING THE PAST 1-2 HRS.

DISCUSSION...RECENT KTLX RADAR IMAGERY SHOWS A WELL DEVELOPED AND
POTENTIALLY TORNADIC SUPERCELL OVER NRN OKLAHOMA COUNTY WITH SEVERAL
OTHER INTENSE UPDRAFTS SW OF THE OKC METRO TRYING TO ACQUIRE ROBUST
SUPERCELL ROTATION.  SURFACE OBS SHOW A THIN CORRIDOR FROM CNTRL OK
THROUGH OSAGE COUNTY OK WHERE PRESSURE FALLS ARE MAXIMIZED AHEAD OF
THE APPROACHING STORMS/DRYLINE.  A NOTED INCREASE IN LOW LEVEL FLOW
HAS BEEN NOTED IN THE PAST HOUR FROM KTLX VWP SHOWING 1 KM FLOW
INCREASING TO AROUND 40 KT.  THIS IS RESULTING IN AROUND 200-250
M2/S2 0-1 KM SRH WHEN INPUTTING THE NRN OKLAHOMA COUNTY STORM/S
STORM MOTION --THUS INCREASING THIS VALUE FROM AROUND 100 M2/S2 1-2
HRS EARLIER.  AS THESE STORMS MATURE AND INTENSIFY...THESE DISCRETE
SUPERCELLS WILL POSSESS CYCLIC VERY STRONG LOW LEVEL MESOCYCLONES.
THE MAIN THREAT WILL BE SEVERAL TORNADOES DOWNSTREAM OF THESE
SUPERCELLS /POTENTIALLY LONG LIVED AND DAMAGING/ IN ADDITION TO
LARGE TO VERY LARGE HAIL AND DMGG WINDS.

..SMITH.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   35009789 35829738 35979656 35709628 35299660 35099702
            35009789

000
ACUS11 KWNS 192138
SWOMCD
SPC MCD 192137
OKZ000-192230-

MESOSCALE DISCUSSION 0703
NWS STORM PREDICTION CENTER NORMAN OK
0437 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL OK

CONCERNING...TORNADO WATCH 182...

VALID 192137Z - 192230Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 182 CONTINUES.

SUMMARY...SUPERCELL TORNADO POTENTIAL WILL CONTINUE TO MARKEDLY
INCREASE ACROSS CNTRL OK OVER THE NEXT HOUR AS THE LOW LEVEL WIND
PROFILE HAS INTENSIFIED SOME DURING THE PAST 1-2 HRS.

DISCUSSION...RECENT KTLX RADAR IMAGERY SHOWS A WELL DEVELOPED AND
POTENTIALLY TORNADIC SUPERCELL OVER NRN OKLAHOMA COUNTY WITH SEVERAL
OTHER INTENSE UPDRAFTS SW OF THE OKC METRO TRYING TO ACQUIRE ROBUST
SUPERCELL ROTATION.  SURFACE OBS SHOW A THIN CORRIDOR FROM CNTRL OK
THROUGH OSAGE COUNTY OK WHERE PRESSURE FALLS ARE MAXIMIZED AHEAD OF
THE APPROACHING STORMS/DRYLINE.  A NOTED INCREASE IN LOW LEVEL FLOW
HAS BEEN NOTED IN THE PAST HOUR FROM KTLX VWP SHOWING 1 KM FLOW
INCREASING TO AROUND 40 KT.  THIS IS RESULTING IN AROUND 200-250
M2/S2 0-1 KM SRH WHEN INPUTTING THE NRN OKLAHOMA COUNTY STORM/S
STORM MOTION --THUS INCREASING THIS VALUE FROM AROUND 100 M2/S2 1-2
HRS EARLIER.  AS THESE STORMS MATURE AND INTENSIFY...THESE DISCRETE
SUPERCELLS WILL POSSESS CYCLIC VERY STRONG LOW LEVEL MESOCYCLONES.
THE MAIN THREAT WILL BE SEVERAL TORNADOES DOWNSTREAM OF THESE
SUPERCELLS /POTENTIALLY LONG LIVED AND DAMAGING/ IN ADDITION TO
LARGE TO VERY LARGE HAIL AND DMGG WINDS.

..SMITH.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   35009789 35829738 35979656 35709628 35299660 35099702
            35009789

000
ACUS11 KWNS 192138
SWOMCD
SPC MCD 192137
OKZ000-192230-

MESOSCALE DISCUSSION 0703
NWS STORM PREDICTION CENTER NORMAN OK
0437 PM CDT SUN MAY 19 2013

AREAS AFFECTED...CNTRL OK

CONCERNING...TORNADO WATCH 182...

VALID 192137Z - 192230Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 182 CONTINUES.

SUMMARY...SUPERCELL TORNADO POTENTIAL WILL CONTINUE TO MARKEDLY
INCREASE ACROSS CNTRL OK OVER THE NEXT HOUR AS THE LOW LEVEL WIND
PROFILE HAS INTENSIFIED SOME DURING THE PAST 1-2 HRS.

DISCUSSION...RECENT KTLX RADAR IMAGERY SHOWS A WELL DEVELOPED AND
POTENTIALLY TORNADIC SUPERCELL OVER NRN OKLAHOMA COUNTY WITH SEVERAL
OTHER INTENSE UPDRAFTS SW OF THE OKC METRO TRYING TO ACQUIRE ROBUST
SUPERCELL ROTATION.  SURFACE OBS SHOW A THIN CORRIDOR FROM CNTRL OK
THROUGH OSAGE COUNTY OK WHERE PRESSURE FALLS ARE MAXIMIZED AHEAD OF
THE APPROACHING STORMS/DRYLINE.  A NOTED INCREASE IN LOW LEVEL FLOW
HAS BEEN NOTED IN THE PAST HOUR FROM KTLX VWP SHOWING 1 KM FLOW
INCREASING TO AROUND 40 KT.  THIS IS RESULTING IN AROUND 200-250
M2/S2 0-1 KM SRH WHEN INPUTTING THE NRN OKLAHOMA COUNTY STORM/S
STORM MOTION --THUS INCREASING THIS VALUE FROM AROUND 100 M2/S2 1-2
HRS EARLIER.  AS THESE STORMS MATURE AND INTENSIFY...THESE DISCRETE
SUPERCELLS WILL POSSESS CYCLIC VERY STRONG LOW LEVEL MESOCYCLONES.
THE MAIN THREAT WILL BE SEVERAL TORNADOES DOWNSTREAM OF THESE
SUPERCELLS /POTENTIALLY LONG LIVED AND DAMAGING/ IN ADDITION TO
LARGE TO VERY LARGE HAIL AND DMGG WINDS.

..SMITH.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   35009789 35829738 35979656 35709628 35299660 35099702
            35009789

000
ACUS11 KWNS 192135
SWOMCD
SPC MCD 192134
NEZ000-192230-

MESOSCALE DISCUSSION 0702
NWS STORM PREDICTION CENTER NORMAN OK
0434 PM CDT SUN MAY 19 2013

AREAS AFFECTED...S-CNTRL  AND NERN NEB

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 192134Z - 192230Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE THREAT FOR LARGE HAIL AND PERHAPS A TORNADO WILL
PERSIST THROUGH THIS EVENING AND AN ADDITIONAL WATCH WILL BE
REQUIRED.

DISCUSSION...A NUMBER OF STRONG-SEVERE STORMS HAVE DEVELOPED THIS
AFTERNOON OVER S-CNTRL NEB WHERE DEEP-LAYER ASCENT IS BEING
AUGMENTED BY THE UPPER LOW SLOWLY LIFTING NEWD.  HERE...THE
COMBINATION OF STEEP LOW- TO MIDLEVEL LAPSE RATES AND A MODESTLY
MOIST BOUNDARY LAYER HAS YIELDED A MODERATELY UNSTABLE AIR MASS WITH
MLCAPE OF 1000-1500 J/KG.  WHEN COUPLED WITH A VERTICALLY VEERING
WIND PROFILE AND SUFFICIENT DEEP-LAYER SHEAR...THE SETUP WILL REMAIN
SUPPORTIVE OF SUPERCELLS THROUGH THIS EVENING.  LARGE HAIL WILL BE
THE PRIMARY HAZARD OWING TO THE STEEP LAPSE RATES AND COOL MIDLEVEL
TEMPERATURES PROFILES.  HOWEVER...A TORNADO WILL BE POSSIBLE DUE TO
BACKED LOW-LEVEL FLOW AND AMBIENT VERTICAL VORTICITY ASSOCIATED WITH
THE DEEP-LAYER CYCLONE.

..MEAD/CORFIDI.. 05/19/2013

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

ATTN...WFO...OAX...GID...LBF...

LAT...LON   40329992 41179945 41789913 42029885 42089772 41139746
            40459807 40139850 40089937 40329992

000
ACUS11 KWNS 192135
SWOMCD
SPC MCD 192134
NEZ000-192230-

MESOSCALE DISCUSSION 0702
NWS STORM PREDICTION CENTER NORMAN OK
0434 PM CDT SUN MAY 19 2013

AREAS AFFECTED...S-CNTRL  AND NERN NEB

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 192134Z - 192230Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE THREAT FOR LARGE HAIL AND PERHAPS A TORNADO WILL
PERSIST THROUGH THIS EVENING AND AN ADDITIONAL WATCH WILL BE
REQUIRED.

DISCUSSION...A NUMBER OF STRONG-SEVERE STORMS HAVE DEVELOPED THIS
AFTERNOON OVER S-CNTRL NEB WHERE DEEP-LAYER ASCENT IS BEING
AUGMENTED BY THE UPPER LOW SLOWLY LIFTING NEWD.  HERE...THE
COMBINATION OF STEEP LOW- TO MIDLEVEL LAPSE RATES AND A MODESTLY
MOIST BOUNDARY LAYER HAS YIELDED A MODERATELY UNSTABLE AIR MASS WITH
MLCAPE OF 1000-1500 J/KG.  WHEN COUPLED WITH A VERTICALLY VEERING
WIND PROFILE AND SUFFICIENT DEEP-LAYER SHEAR...THE SETUP WILL REMAIN
SUPPORTIVE OF SUPERCELLS THROUGH THIS EVENING.  LARGE HAIL WILL BE
THE PRIMARY HAZARD OWING TO THE STEEP LAPSE RATES AND COOL MIDLEVEL
TEMPERATURES PROFILES.  HOWEVER...A TORNADO WILL BE POSSIBLE DUE TO
BACKED LOW-LEVEL FLOW AND AMBIENT VERTICAL VORTICITY ASSOCIATED WITH
THE DEEP-LAYER CYCLONE.

..MEAD/CORFIDI.. 05/19/2013

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

ATTN...WFO...OAX...GID...LBF...

LAT...LON   40329992 41179945 41789913 42029885 42089772 41139746
            40459807 40139850 40089937 40329992

000
ACUS11 KWNS 192135
SWOMCD
SPC MCD 192134
NEZ000-192230-

MESOSCALE DISCUSSION 0702
NWS STORM PREDICTION CENTER NORMAN OK
0434 PM CDT SUN MAY 19 2013

AREAS AFFECTED...S-CNTRL  AND NERN NEB

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 192134Z - 192230Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE THREAT FOR LARGE HAIL AND PERHAPS A TORNADO WILL
PERSIST THROUGH THIS EVENING AND AN ADDITIONAL WATCH WILL BE
REQUIRED.

DISCUSSION...A NUMBER OF STRONG-SEVERE STORMS HAVE DEVELOPED THIS
AFTERNOON OVER S-CNTRL NEB WHERE DEEP-LAYER ASCENT IS BEING
AUGMENTED BY THE UPPER LOW SLOWLY LIFTING NEWD.  HERE...THE
COMBINATION OF STEEP LOW- TO MIDLEVEL LAPSE RATES AND A MODESTLY
MOIST BOUNDARY LAYER HAS YIELDED A MODERATELY UNSTABLE AIR MASS WITH
MLCAPE OF 1000-1500 J/KG.  WHEN COUPLED WITH A VERTICALLY VEERING
WIND PROFILE AND SUFFICIENT DEEP-LAYER SHEAR...THE SETUP WILL REMAIN
SUPPORTIVE OF SUPERCELLS THROUGH THIS EVENING.  LARGE HAIL WILL BE
THE PRIMARY HAZARD OWING TO THE STEEP LAPSE RATES AND COOL MIDLEVEL
TEMPERATURES PROFILES.  HOWEVER...A TORNADO WILL BE POSSIBLE DUE TO
BACKED LOW-LEVEL FLOW AND AMBIENT VERTICAL VORTICITY ASSOCIATED WITH
THE DEEP-LAYER CYCLONE.

..MEAD/CORFIDI.. 05/19/2013

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

ATTN...WFO...OAX...GID...LBF...

LAT...LON   40329992 41179945 41789913 42029885 42089772 41139746
            40459807 40139850 40089937 40329992

000
ACUS11 KWNS 192027
SWOMCD
SPC MCD 192027
OKZ000-TXZ000-192130-

MESOSCALE DISCUSSION 0701
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT SUN MAY 19 2013

AREAS AFFECTED...FAR NWRN OK...ERN OK PANHANDLE...FAR NERN TX
PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 192027Z - 192130Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED DMGG WIND AND HAIL THREAT MAY ACCOMPANY
DEVELOPING TSTMS ACROSS THE ERN OK/TX PANHANDLES AND INTO FAR NWRN
OK. COVERAGE/MAGNITUDE OF THE THREAT IS EXPECTED TO REMAIN TOO
MARGINAL TO WARRANT WW ISSUANCE...BUT CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED.

DISCUSSION...A ZONE OF BROAD DEEP-LAYER ASCENT ACCOMPANYING AN UPPER
IMPULSE MOVING ACROSS THE SRN HIGH PLAINS APPEARS TO BE CONTRIBUTING
TO TSTM DEVELOPMENT ACROSS THE ERN TX/OK PANHANDLES AND FAR NWRN OK.
SFC ANALYSIS FROM 20Z INDICATES A COLD FRONT IS BEGINNING TO MERGE
WITH A DRYLINE ACROSS NWRN OK. A TSTM FORMED ALONG THE COLD FRONT
WITHIN RELATIVELY MORE MOIST LOW-LEVEL AIR NEAR 20 WSW AVK...BUT
APPEARS TO NOW BE POSITIONED BEHIND THE WIND SHIFT NOTED ON SFC OBS.
FARTHER W...ADDITIONAL HIGH-BASED CONVECTION HAS BECOME MORE ROBUST
IN THE PAST 1-2 HRS. DESPITE DRIER LOW-LEVEL AIR...STEEP
LOW-/MID-LEVEL LAPSE RATES ARE YIELDING MLCAPE VALUES NEAR 500 J/KG.
THIS...ALONG WITH STRONG MIDLEVEL FLOW...COULD RESULT IN AN ISOLATED
THREAT FOR STRONG-SVR WINDS AND LARGE HAIL OVER THE NEXT COUPLE
HRS...BEFORE INSTABILITY WANES FURTHER AS DRIER UPSTREAM AIR
CONTINUES SPREADING SEWD.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...OUN...AMA...

LAT...LON   36519821 36329854 36189937 36240059 36480088 36870102
            36970030 36979897 36919829 36519821

000
ACUS11 KWNS 192027
SWOMCD
SPC MCD 192027
OKZ000-TXZ000-192130-

MESOSCALE DISCUSSION 0701
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT SUN MAY 19 2013

AREAS AFFECTED...FAR NWRN OK...ERN OK PANHANDLE...FAR NERN TX
PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 192027Z - 192130Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED DMGG WIND AND HAIL THREAT MAY ACCOMPANY
DEVELOPING TSTMS ACROSS THE ERN OK/TX PANHANDLES AND INTO FAR NWRN
OK. COVERAGE/MAGNITUDE OF THE THREAT IS EXPECTED TO REMAIN TOO
MARGINAL TO WARRANT WW ISSUANCE...BUT CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED.

DISCUSSION...A ZONE OF BROAD DEEP-LAYER ASCENT ACCOMPANYING AN UPPER
IMPULSE MOVING ACROSS THE SRN HIGH PLAINS APPEARS TO BE CONTRIBUTING
TO TSTM DEVELOPMENT ACROSS THE ERN TX/OK PANHANDLES AND FAR NWRN OK.
SFC ANALYSIS FROM 20Z INDICATES A COLD FRONT IS BEGINNING TO MERGE
WITH A DRYLINE ACROSS NWRN OK. A TSTM FORMED ALONG THE COLD FRONT
WITHIN RELATIVELY MORE MOIST LOW-LEVEL AIR NEAR 20 WSW AVK...BUT
APPEARS TO NOW BE POSITIONED BEHIND THE WIND SHIFT NOTED ON SFC OBS.
FARTHER W...ADDITIONAL HIGH-BASED CONVECTION HAS BECOME MORE ROBUST
IN THE PAST 1-2 HRS. DESPITE DRIER LOW-LEVEL AIR...STEEP
LOW-/MID-LEVEL LAPSE RATES ARE YIELDING MLCAPE VALUES NEAR 500 J/KG.
THIS...ALONG WITH STRONG MIDLEVEL FLOW...COULD RESULT IN AN ISOLATED
THREAT FOR STRONG-SVR WINDS AND LARGE HAIL OVER THE NEXT COUPLE
HRS...BEFORE INSTABILITY WANES FURTHER AS DRIER UPSTREAM AIR
CONTINUES SPREADING SEWD.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...OUN...AMA...

LAT...LON   36519821 36329854 36189937 36240059 36480088 36870102
            36970030 36979897 36919829 36519821

000
ACUS11 KWNS 192027
SWOMCD
SPC MCD 192027
OKZ000-TXZ000-192130-

MESOSCALE DISCUSSION 0701
NWS STORM PREDICTION CENTER NORMAN OK
0327 PM CDT SUN MAY 19 2013

AREAS AFFECTED...FAR NWRN OK...ERN OK PANHANDLE...FAR NERN TX
PANHANDLE

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 192027Z - 192130Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED DMGG WIND AND HAIL THREAT MAY ACCOMPANY
DEVELOPING TSTMS ACROSS THE ERN OK/TX PANHANDLES AND INTO FAR NWRN
OK. COVERAGE/MAGNITUDE OF THE THREAT IS EXPECTED TO REMAIN TOO
MARGINAL TO WARRANT WW ISSUANCE...BUT CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED.

DISCUSSION...A ZONE OF BROAD DEEP-LAYER ASCENT ACCOMPANYING AN UPPER
IMPULSE MOVING ACROSS THE SRN HIGH PLAINS APPEARS TO BE CONTRIBUTING
TO TSTM DEVELOPMENT ACROSS THE ERN TX/OK PANHANDLES AND FAR NWRN OK.
SFC ANALYSIS FROM 20Z INDICATES A COLD FRONT IS BEGINNING TO MERGE
WITH A DRYLINE ACROSS NWRN OK. A TSTM FORMED ALONG THE COLD FRONT
WITHIN RELATIVELY MORE MOIST LOW-LEVEL AIR NEAR 20 WSW AVK...BUT
APPEARS TO NOW BE POSITIONED BEHIND THE WIND SHIFT NOTED ON SFC OBS.
FARTHER W...ADDITIONAL HIGH-BASED CONVECTION HAS BECOME MORE ROBUST
IN THE PAST 1-2 HRS. DESPITE DRIER LOW-LEVEL AIR...STEEP
LOW-/MID-LEVEL LAPSE RATES ARE YIELDING MLCAPE VALUES NEAR 500 J/KG.
THIS...ALONG WITH STRONG MIDLEVEL FLOW...COULD RESULT IN AN ISOLATED
THREAT FOR STRONG-SVR WINDS AND LARGE HAIL OVER THE NEXT COUPLE
HRS...BEFORE INSTABILITY WANES FURTHER AS DRIER UPSTREAM AIR
CONTINUES SPREADING SEWD.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...OUN...AMA...

LAT...LON   36519821 36329854 36189937 36240059 36480088 36870102
            36970030 36979897 36919829 36519821

000
ACUS11 KWNS 191955
SWOMCD
SPC MCD 191955
FLZ000-GAZ000-ALZ000-192030-

MESOSCALE DISCUSSION 0700
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT SUN MAY 19 2013

AREAS AFFECTED...W-CNTRL AND SRN GA...FAR NRN FL

CONCERNING...SEVERE THUNDERSTORM WATCH 179...

VALID 191955Z - 192030Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 179
CONTINUES.

SUMMARY...STRONG-SVR WINDS MAY CONTINUE TO ACCOMPANY S-SEWD
PROPAGATING TSTM CLUSTER ACROSS SRN GA AND PERHAPS INTO FAR NRN FL.
LOCAL OFFICES MAY CLEAR COUNTIES FROM WW 179 IN ITS WAKE...WHERE THE
BOUNDARY LAYER HAS STABILIZED.

DISCUSSION...RADAR TRENDS INDICATE A TSTM CLUSTER OVER W-CNTRL GA
HAS BECOME LESS ORGANIZED OVER THE PAST 1-2 HRS...WITH A DIMINISHING
COMMA HEAD STRUCTURE. PROPAGATION NOW APPEARS TO BE OCCURRING
PARALLEL TO AN OUTFLOW BOUNDARY ACCOMPANYING EARLIER CONVECTION OVER
E-CNTRL GA. ALTHOUGH THE DOWNSTREAM ENVIRONMENT REMAINS SUFFICIENTLY
UNSTABLE TO MAINTAIN CONVECTION /I.E. 1300-1800 J/KG MLCAPE PER RAP
OBJECTIVE ANALYSIS/...WEAK DEEP-LAYER FLOW SUGGESTS THAT THIS
CLUSTER MAY CONTINUE STRUGGLING TO ORGANIZE. HOWEVER...A
STRONG-MARGINALLY SVR WIND THREAT MAY STILL EXIST GIVEN THE DEGREE
OF INSTABILITY PRESENT AND STEEP LOW-LEVEL LAPSE RATES.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...CHS...JAX...FFC...TAE...BMX...

LAT...LON   32638260 30958158 30498145 30078157 30108238 29858252
            30008285 30308371 30588411 30718473 31068496 31798492
            32488490 32768373 32638260

000
ACUS11 KWNS 191955
SWOMCD
SPC MCD 191955
FLZ000-GAZ000-ALZ000-192030-

MESOSCALE DISCUSSION 0700
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT SUN MAY 19 2013

AREAS AFFECTED...W-CNTRL AND SRN GA...FAR NRN FL

CONCERNING...SEVERE THUNDERSTORM WATCH 179...

VALID 191955Z - 192030Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 179
CONTINUES.

SUMMARY...STRONG-SVR WINDS MAY CONTINUE TO ACCOMPANY S-SEWD
PROPAGATING TSTM CLUSTER ACROSS SRN GA AND PERHAPS INTO FAR NRN FL.
LOCAL OFFICES MAY CLEAR COUNTIES FROM WW 179 IN ITS WAKE...WHERE THE
BOUNDARY LAYER HAS STABILIZED.

DISCUSSION...RADAR TRENDS INDICATE A TSTM CLUSTER OVER W-CNTRL GA
HAS BECOME LESS ORGANIZED OVER THE PAST 1-2 HRS...WITH A DIMINISHING
COMMA HEAD STRUCTURE. PROPAGATION NOW APPEARS TO BE OCCURRING
PARALLEL TO AN OUTFLOW BOUNDARY ACCOMPANYING EARLIER CONVECTION OVER
E-CNTRL GA. ALTHOUGH THE DOWNSTREAM ENVIRONMENT REMAINS SUFFICIENTLY
UNSTABLE TO MAINTAIN CONVECTION /I.E. 1300-1800 J/KG MLCAPE PER RAP
OBJECTIVE ANALYSIS/...WEAK DEEP-LAYER FLOW SUGGESTS THAT THIS
CLUSTER MAY CONTINUE STRUGGLING TO ORGANIZE. HOWEVER...A
STRONG-MARGINALLY SVR WIND THREAT MAY STILL EXIST GIVEN THE DEGREE
OF INSTABILITY PRESENT AND STEEP LOW-LEVEL LAPSE RATES.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...CHS...JAX...FFC...TAE...BMX...

LAT...LON   32638260 30958158 30498145 30078157 30108238 29858252
            30008285 30308371 30588411 30718473 31068496 31798492
            32488490 32768373 32638260

000
ACUS11 KWNS 191955
SWOMCD
SPC MCD 191955
FLZ000-GAZ000-ALZ000-192030-

MESOSCALE DISCUSSION 0700
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT SUN MAY 19 2013

AREAS AFFECTED...W-CNTRL AND SRN GA...FAR NRN FL

CONCERNING...SEVERE THUNDERSTORM WATCH 179...

VALID 191955Z - 192030Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 179
CONTINUES.

SUMMARY...STRONG-SVR WINDS MAY CONTINUE TO ACCOMPANY S-SEWD
PROPAGATING TSTM CLUSTER ACROSS SRN GA AND PERHAPS INTO FAR NRN FL.
LOCAL OFFICES MAY CLEAR COUNTIES FROM WW 179 IN ITS WAKE...WHERE THE
BOUNDARY LAYER HAS STABILIZED.

DISCUSSION...RADAR TRENDS INDICATE A TSTM CLUSTER OVER W-CNTRL GA
HAS BECOME LESS ORGANIZED OVER THE PAST 1-2 HRS...WITH A DIMINISHING
COMMA HEAD STRUCTURE. PROPAGATION NOW APPEARS TO BE OCCURRING
PARALLEL TO AN OUTFLOW BOUNDARY ACCOMPANYING EARLIER CONVECTION OVER
E-CNTRL GA. ALTHOUGH THE DOWNSTREAM ENVIRONMENT REMAINS SUFFICIENTLY
UNSTABLE TO MAINTAIN CONVECTION /I.E. 1300-1800 J/KG MLCAPE PER RAP
OBJECTIVE ANALYSIS/...WEAK DEEP-LAYER FLOW SUGGESTS THAT THIS
CLUSTER MAY CONTINUE STRUGGLING TO ORGANIZE. HOWEVER...A
STRONG-MARGINALLY SVR WIND THREAT MAY STILL EXIST GIVEN THE DEGREE
OF INSTABILITY PRESENT AND STEEP LOW-LEVEL LAPSE RATES.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...CHS...JAX...FFC...TAE...BMX...

LAT...LON   32638260 30958158 30498145 30078157 30108238 29858252
            30008285 30308371 30588411 30718473 31068496 31798492
            32488490 32768373 32638260

000
ACUS11 KWNS 191944
SWOMCD
SPC MCD 191943
TNZ000-ALZ000-192115-

MESOSCALE DISCUSSION 0699
NWS STORM PREDICTION CENTER NORMAN OK
0243 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MIDDLE TN THROUGH NERN AL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 191943Z - 192115Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP WWD AND SWWD THROUGH MIDDLE
TN AND NERN AL THIS AFTERNOON AND EARLY EVENING. STRONGER ACTIVITY
WILL POSE A THREAT FOR ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS.
TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

DISCUSSION...THIS AFTERNOON A LARGE CLUSTER OF ONGOING MULTICELL
STORMS EXTENDS FROM NRN GA THROUGH ERN MIDDLE TN. WEST OF THIS
ACTIVITY...THE ATMOSPHERE HAS BECOME VERY UNSTABLE ALONG THE ERN
FRINGE OF THE STEEPER MID-LEVEL LAPSE RATE PLUME WITH MLCAPE AROUND
3000 J/KG. HOWEVER...IT IS LIKELY THAT STRONGER CONVECTIVE
INHIBITION EXISTS WITH WWD EXTENT INTO THE UNSTABLE WARM SECTOR.
WHILE SWLY LOW LEVEL WINDS FAVOR WSWWD PROPAGATION OF THE
STORMS...WLY MID-UPPER FLOW AND AT LEAST MODEST CONVECTIVE
INHIBITION MAY BE LIMITING FACTORS FOR RAPID WWD DEVELOPMENT AND
LOWERS OVERALL CONFIDENCE IN A MORE ORGANIZED SEVERE THREAT.
NEVERTHELESS...STORMS WILL PROBABLY CONTINUE TO DEVELOP AT LEAST
SLOWLY WWD AND SWWD THIS AFTERNOON AND SOME NWWD BACKBUILDING MIGHT
ALSO OCCUR. THERMODYNAMIC ENVIRONMENT WILL FAVOR A RISK FOR ISOLATED
DAMAGING WIND GUSTS AND LARGE HAIL.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...MRX...OHX...BMX...HUN...

LAT...LON   36208632 35608585 34448553 34038594 34298659 35298673
            36018676 36208632

000
ACUS11 KWNS 191944
SWOMCD
SPC MCD 191943
TNZ000-ALZ000-192115-

MESOSCALE DISCUSSION 0699
NWS STORM PREDICTION CENTER NORMAN OK
0243 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MIDDLE TN THROUGH NERN AL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 191943Z - 192115Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP WWD AND SWWD THROUGH MIDDLE
TN AND NERN AL THIS AFTERNOON AND EARLY EVENING. STRONGER ACTIVITY
WILL POSE A THREAT FOR ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS.
TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

DISCUSSION...THIS AFTERNOON A LARGE CLUSTER OF ONGOING MULTICELL
STORMS EXTENDS FROM NRN GA THROUGH ERN MIDDLE TN. WEST OF THIS
ACTIVITY...THE ATMOSPHERE HAS BECOME VERY UNSTABLE ALONG THE ERN
FRINGE OF THE STEEPER MID-LEVEL LAPSE RATE PLUME WITH MLCAPE AROUND
3000 J/KG. HOWEVER...IT IS LIKELY THAT STRONGER CONVECTIVE
INHIBITION EXISTS WITH WWD EXTENT INTO THE UNSTABLE WARM SECTOR.
WHILE SWLY LOW LEVEL WINDS FAVOR WSWWD PROPAGATION OF THE
STORMS...WLY MID-UPPER FLOW AND AT LEAST MODEST CONVECTIVE
INHIBITION MAY BE LIMITING FACTORS FOR RAPID WWD DEVELOPMENT AND
LOWERS OVERALL CONFIDENCE IN A MORE ORGANIZED SEVERE THREAT.
NEVERTHELESS...STORMS WILL PROBABLY CONTINUE TO DEVELOP AT LEAST
SLOWLY WWD AND SWWD THIS AFTERNOON AND SOME NWWD BACKBUILDING MIGHT
ALSO OCCUR. THERMODYNAMIC ENVIRONMENT WILL FAVOR A RISK FOR ISOLATED
DAMAGING WIND GUSTS AND LARGE HAIL.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...MRX...OHX...BMX...HUN...

LAT...LON   36208632 35608585 34448553 34038594 34298659 35298673
            36018676 36208632

000
ACUS11 KWNS 191944
SWOMCD
SPC MCD 191943
TNZ000-ALZ000-192115-

MESOSCALE DISCUSSION 0699
NWS STORM PREDICTION CENTER NORMAN OK
0243 PM CDT SUN MAY 19 2013

AREAS AFFECTED...MIDDLE TN THROUGH NERN AL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 191943Z - 192115Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP WWD AND SWWD THROUGH MIDDLE
TN AND NERN AL THIS AFTERNOON AND EARLY EVENING. STRONGER ACTIVITY
WILL POSE A THREAT FOR ISOLATED LARGE HAIL AND DAMAGING WIND GUSTS.
TRENDS WILL CONTINUE TO BE MONITORED FOR A POSSIBLE WW.

DISCUSSION...THIS AFTERNOON A LARGE CLUSTER OF ONGOING MULTICELL
STORMS EXTENDS FROM NRN GA THROUGH ERN MIDDLE TN. WEST OF THIS
ACTIVITY...THE ATMOSPHERE HAS BECOME VERY UNSTABLE ALONG THE ERN
FRINGE OF THE STEEPER MID-LEVEL LAPSE RATE PLUME WITH MLCAPE AROUND
3000 J/KG. HOWEVER...IT IS LIKELY THAT STRONGER CONVECTIVE
INHIBITION EXISTS WITH WWD EXTENT INTO THE UNSTABLE WARM SECTOR.
WHILE SWLY LOW LEVEL WINDS FAVOR WSWWD PROPAGATION OF THE
STORMS...WLY MID-UPPER FLOW AND AT LEAST MODEST CONVECTIVE
INHIBITION MAY BE LIMITING FACTORS FOR RAPID WWD DEVELOPMENT AND
LOWERS OVERALL CONFIDENCE IN A MORE ORGANIZED SEVERE THREAT.
NEVERTHELESS...STORMS WILL PROBABLY CONTINUE TO DEVELOP AT LEAST
SLOWLY WWD AND SWWD THIS AFTERNOON AND SOME NWWD BACKBUILDING MIGHT
ALSO OCCUR. THERMODYNAMIC ENVIRONMENT WILL FAVOR A RISK FOR ISOLATED
DAMAGING WIND GUSTS AND LARGE HAIL.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...MRX...OHX...BMX...HUN...

LAT...LON   36208632 35608585 34448553 34038594 34298659 35298673
            36018676 36208632

000
ACUS01 KWNS 191942
SWODY1
SPC AC 191940

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0240 PM CDT SUN MAY 19 2013

VALID 192000Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM CNTRL OK TO WRN MO...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
NCNTRL TX TO CNTRL MN...

...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF MIDDLE TN INTO
SRN GA...

...FEW STRONG TORNADOES POSSIBLE ACROSS MDT RISK AREA...

STRONG HEATING ACROSS WRN OK HAS REMOVED THE CAP ALONG THE
DRYLINE...PER DEEPENING CU FROM THE RED RIVER NEAR SPS...NWD ACROSS
CADDO COUNTY INTO SCNTRL KS OVER HARPER COUNTY WHERE LIGHTNING IS
NOW OBSERVED WITH DEEPEST CONVECTION.  WITH TEMPERATURES CONTINUING
TO RISE THERE IS REASON TO BELIEVE SCATTERED SUPERCELLS WILL EMERGE
ALONG THE DRYLINE...ESPECIALLY NORTH OF I-40 INTO ERN KS WHERE VERY
MOIST/BUOYANT AIRMASS CURRENTLY RESIDES.  VERTICAL SHEAR PROFILES
ARE SUCH THAT LONG-LIVED SUPERCELLS ARE EXPECTED...AND IF SUFFICIENT
COUPLING WITH MOIST BOUNDARY LAYER OCCURS A FEW STRONG TORNADOES MAY
BE NOTED ACROSS THE MDT RISK INTO THE EVENING HOURS...ESPECIALLY
INVOF OLD OUTFLOW BOUNDARY THAT WAS DRAPED ACROSS NERN OK/SERN KS.
ALTHOUGH IT HAS LOST ITS IDENTITY...BOUNDARY LAYER WINDS ARE BACKED
A BIT ACROSS THIS REGION AND THIS MAY SERVE TO ENHANCE LOW LEVEL
SHEAR.


...ERN TN...NERN AL/NWRN GA...

HAVE OPTED TO INCREASE SEVERE PROBS ACROSS PARTS OF ERN TN INTO NERN
AL/NWRN GA TO ACCOUNT FOR NW-SE ORIENTED CONVECTIVE CLUSTER THAT
SHOULD PROPAGATE SWD ACROSS THIS REGION.  LOCALLY DAMAGING WINDS MAY
ACCOMPANY THIS UPWARD EVOLVING COMPLEX OF STORMS BEFORE DIURNAL
COOLING RESULTS IN WEAKENING.

...ELSEWHERE...

EARLIER THOUGHTS REGARDING DEEP CONVECTION REMAIN AND ONLY MINOR
CHANGES HAVE BEEN MADE TO 1630Z FORECAST.

..DARROW.. 05/19/2013

.PREV DISCUSSION... /ISSUED 1115 AM CDT SUN MAY 19 2013/

...SYNOPSIS...
A DEEP LAYER CYCLONE APPEARS LIKELY TO CONTINUE TO EVOLVE THROUGH
THIS FORECAST PERIOD OVER THE MID MISSOURI VALLEY REGION.  IN
ASSOCIATION WITH THIS FEATURE...MID/UPPER FLOW HAS ALREADY
STRENGTHENED ACROSS THE TEXAS/OKLAHOMA PANHANDLE REGION THROUGH THE
CENTRAL PLAINS AND UPPER MISSISSIPPI VALLEY...IN A BELT CURVING
CYCLONICALLY OUT OF THE INTERMOUNTAIN REGION.  WITHIN THIS
REGIME...A SERIES OF SHORT WAVE IMPULSES/SPEED MAXIMA HAVE AND WILL
CONTINUE TO EMERGE FROM THE INTERMOUNTAIN WEST...WHILE ADDITIONAL
PERTURBATIONS CONTINUE TO DIG INTO THE GREAT BASIN.

EAST OF THE ROCKIES...MID-LEVEL LAPSE RATES REMAIN VERY STEEP OVER A
BROAD AREA...FROM THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY
SOUTHWARD TO GULF COASTAL AREAS.  ATOP A RELATIVELY MOIST BOUNDARY
LAYER...THIS WILL CONTRIBUTE TO SUBSTANTIAL CONVECTIVE INSTABILITY
AND SIZABLE CAPE ACROSS A BROAD AREA OF THE PLAINS AND MISSISSIPPI
VALLEY REGION.  THIS IS EXPECTED TO BE ACCOMPANIED BY CONSIDERABLE
THUNDERSTORM ACTIVITY...INCLUDING ANOTHER OUTBREAK OF SEVERE
WEATHER...PARTICULARLY ACROSS PARTS OF EASTERN KANSAS AND OKLAHOMA
INTO PARTS OF MISSOURI.

ADDITIONALLY...ON THE WESTERN PERIPHERY OF A WEAK CYCLONIC BELT OF
FLOW DEVELOPING EASTWARD ACROSS THE SOUTH ATLANTIC COAST
REGION...LIFT AND STEEPENING MID-LEVEL LAPSE RATES ASSOCIATED WITH
LOWER/MID TROPOSPHERIC WARM ADVECTION WILL MAINTAIN A RISK FOR
THUNDERSTORM ACTIVITY FROM PARTS OF THE TENNESSEE VALLEY INTO
GEORGIA AND NORTHERN FLORIDA.  MARGINALLY SEVERE WIND AND HAIL DO
NOT APPEAR OUT OF THE QUESTION IN STRONGER STORMS...PARTICULARLY
WITH ADDITIONAL HEATING AHEAD OF AN ORGANIZING STORM CLUSTER NOW
ADVANCING WEST THROUGH SOUTH OF ATLANTA GA.

...PLAINS/MISSISSIPPI VALLEY...
ONE SHORT WAVE IMPULSE IS CURRENTLY IN THE PROCESS OF TURNING
NORTHEAST OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY.
THIS FEATURE IS AIDING INCREASING STORM DEVELOPMENT ACROSS PARTS OF
NORTHEAST MISSOURI INTO WEST CENTRAL ILLINOIS.  SOME SEVERE
HAIL/WIND POTENTIAL MAY EXIST WITH THIS ACTIVITY... BUT A MORE
SUBSTANTIVE SEVERE WEATHER RISK MAY AWAIT FURTHER BOUNDARY LAYER
DESTABILIZATION AND WEAKENING INHIBITION ACROSS IOWA NORTHWARD INTO
PARTS OF MINNESOTA AND WISCONSIN LATER TODAY.

THE PRIMARY SEVERE WEATHER POTENTIAL IS EXPECTED TO DEVELOP IN THE
WAKE OF THIS INITIAL IMPULSE...AS ANOTHER CONTINUES TO PIVOT EAST OF
THE CENTRAL HIGH PLAINS THIS AFTERNOON.  THIS SEEMS MOST LIKELY TO
BECOME FOCUSED ALONG/SOUTH AND EAST OF A REMNANT CONVECTIVELY
GENERATED BOUNDARY THAT CURRENTLY CURVES FROM THE MISSOURI OZARKS
INTO NORTHERN OKLAHOMA.  A NORTHWARD RETREAT OF THIS BOUNDARY INTO
SOUTHERN KANSAS IS STILL EXPECTED...AND LATEST HIGH RESOLUTION RAPID
REFRESH APPEARS REASONABLE SUGGESTING INITIATION OF STORMS ALONG THE
INTERSECTION OF THIS BOUNDARY AND AN EASTWARD ADVANCING
DRYLINE...ACROSS NORTH CENTRAL OKLAHOMA OR SOUTH CENTRAL KANSAS...BY
19-20Z.

AIDED BY FORCING IN THE EXIT REGION OF A MID-LEVEL SPEED MAXIMUM
NOSING NORTHEASTWARD ACROSS THE SOUTH CENTRAL PLAINS...UPSCALE
CONVECTIVE GROWTH INTO A SUBSTANTIAL MESOSCALE CONVECTIVE SYSTEM IS
EXPECTED LATE THIS AFTERNOON AND EVENING.  IN THE PRESENCE OF STRONG
DEEP LAYER SHEAR...40-50 KT SOUTHERLY 850 MB FLOW NEAR AND SOUTH OF
THE CONVECTIVE BOUNDARY WILL CONTRIBUTE TO SIZABLE CLOCKWISE CURVED
LOW-LEVEL HODOGRAPHS SUPPORTIVE OF THE RISK FOR TORNADOES.  HIGHEST
PROBABILITIES FOR TORNADOES...SOME POSSIBLY STRONG...MAY BE
SUPERCELLS ON THE SOUTHERN FLANK OF THE EVOLVING CONVECTIVE
SYSTEM...ACROSS SOUTHEAST KANSAS INTO PARTS OF WEST
CENTRAL/SOUTHEAST MISSOURI...AS WELL AS WITH STORMS INITIATING AND
ADVANCING NORTHEASTWARD OFF THE DRYLINE...ACROSS NORTHEASTERN
OKLAHOMA.  FURTHER STRENGTHENING OF THE 850 MB JET ACROSS EASTERN
OKLAHOMA INTO SOUTHWEST MISSOURI WILL MAINTAIN TORNADIC POTENTIAL
WELL INTO THE EVENING HOURS...WITH ONE OR TWO LONG-LIVED TORNADIC
SUPERCELLS POSSIBLE.

000
ACUS01 KWNS 191942
SWODY1
SPC AC 191940

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0240 PM CDT SUN MAY 19 2013

VALID 192000Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM CNTRL OK TO WRN MO...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
NCNTRL TX TO CNTRL MN...

...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF MIDDLE TN INTO
SRN GA...

...FEW STRONG TORNADOES POSSIBLE ACROSS MDT RISK AREA...

STRONG HEATING ACROSS WRN OK HAS REMOVED THE CAP ALONG THE
DRYLINE...PER DEEPENING CU FROM THE RED RIVER NEAR SPS...NWD ACROSS
CADDO COUNTY INTO SCNTRL KS OVER HARPER COUNTY WHERE LIGHTNING IS
NOW OBSERVED WITH DEEPEST CONVECTION.  WITH TEMPERATURES CONTINUING
TO RISE THERE IS REASON TO BELIEVE SCATTERED SUPERCELLS WILL EMERGE
ALONG THE DRYLINE...ESPECIALLY NORTH OF I-40 INTO ERN KS WHERE VERY
MOIST/BUOYANT AIRMASS CURRENTLY RESIDES.  VERTICAL SHEAR PROFILES
ARE SUCH THAT LONG-LIVED SUPERCELLS ARE EXPECTED...AND IF SUFFICIENT
COUPLING WITH MOIST BOUNDARY LAYER OCCURS A FEW STRONG TORNADOES MAY
BE NOTED ACROSS THE MDT RISK INTO THE EVENING HOURS...ESPECIALLY
INVOF OLD OUTFLOW BOUNDARY THAT WAS DRAPED ACROSS NERN OK/SERN KS.
ALTHOUGH IT HAS LOST ITS IDENTITY...BOUNDARY LAYER WINDS ARE BACKED
A BIT ACROSS THIS REGION AND THIS MAY SERVE TO ENHANCE LOW LEVEL
SHEAR.


...ERN TN...NERN AL/NWRN GA...

HAVE OPTED TO INCREASE SEVERE PROBS ACROSS PARTS OF ERN TN INTO NERN
AL/NWRN GA TO ACCOUNT FOR NW-SE ORIENTED CONVECTIVE CLUSTER THAT
SHOULD PROPAGATE SWD ACROSS THIS REGION.  LOCALLY DAMAGING WINDS MAY
ACCOMPANY THIS UPWARD EVOLVING COMPLEX OF STORMS BEFORE DIURNAL
COOLING RESULTS IN WEAKENING.

...ELSEWHERE...

EARLIER THOUGHTS REGARDING DEEP CONVECTION REMAIN AND ONLY MINOR
CHANGES HAVE BEEN MADE TO 1630Z FORECAST.

..DARROW.. 05/19/2013

.PREV DISCUSSION... /ISSUED 1115 AM CDT SUN MAY 19 2013/

...SYNOPSIS...
A DEEP LAYER CYCLONE APPEARS LIKELY TO CONTINUE TO EVOLVE THROUGH
THIS FORECAST PERIOD OVER THE MID MISSOURI VALLEY REGION.  IN
ASSOCIATION WITH THIS FEATURE...MID/UPPER FLOW HAS ALREADY
STRENGTHENED ACROSS THE TEXAS/OKLAHOMA PANHANDLE REGION THROUGH THE
CENTRAL PLAINS AND UPPER MISSISSIPPI VALLEY...IN A BELT CURVING
CYCLONICALLY OUT OF THE INTERMOUNTAIN REGION.  WITHIN THIS
REGIME...A SERIES OF SHORT WAVE IMPULSES/SPEED MAXIMA HAVE AND WILL
CONTINUE TO EMERGE FROM THE INTERMOUNTAIN WEST...WHILE ADDITIONAL
PERTURBATIONS CONTINUE TO DIG INTO THE GREAT BASIN.

EAST OF THE ROCKIES...MID-LEVEL LAPSE RATES REMAIN VERY STEEP OVER A
BROAD AREA...FROM THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY
SOUTHWARD TO GULF COASTAL AREAS.  ATOP A RELATIVELY MOIST BOUNDARY
LAYER...THIS WILL CONTRIBUTE TO SUBSTANTIAL CONVECTIVE INSTABILITY
AND SIZABLE CAPE ACROSS A BROAD AREA OF THE PLAINS AND MISSISSIPPI
VALLEY REGION.  THIS IS EXPECTED TO BE ACCOMPANIED BY CONSIDERABLE
THUNDERSTORM ACTIVITY...INCLUDING ANOTHER OUTBREAK OF SEVERE
WEATHER...PARTICULARLY ACROSS PARTS OF EASTERN KANSAS AND OKLAHOMA
INTO PARTS OF MISSOURI.

ADDITIONALLY...ON THE WESTERN PERIPHERY OF A WEAK CYCLONIC BELT OF
FLOW DEVELOPING EASTWARD ACROSS THE SOUTH ATLANTIC COAST
REGION...LIFT AND STEEPENING MID-LEVEL LAPSE RATES ASSOCIATED WITH
LOWER/MID TROPOSPHERIC WARM ADVECTION WILL MAINTAIN A RISK FOR
THUNDERSTORM ACTIVITY FROM PARTS OF THE TENNESSEE VALLEY INTO
GEORGIA AND NORTHERN FLORIDA.  MARGINALLY SEVERE WIND AND HAIL DO
NOT APPEAR OUT OF THE QUESTION IN STRONGER STORMS...PARTICULARLY
WITH ADDITIONAL HEATING AHEAD OF AN ORGANIZING STORM CLUSTER NOW
ADVANCING WEST THROUGH SOUTH OF ATLANTA GA.

...PLAINS/MISSISSIPPI VALLEY...
ONE SHORT WAVE IMPULSE IS CURRENTLY IN THE PROCESS OF TURNING
NORTHEAST OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY.
THIS FEATURE IS AIDING INCREASING STORM DEVELOPMENT ACROSS PARTS OF
NORTHEAST MISSOURI INTO WEST CENTRAL ILLINOIS.  SOME SEVERE
HAIL/WIND POTENTIAL MAY EXIST WITH THIS ACTIVITY... BUT A MORE
SUBSTANTIVE SEVERE WEATHER RISK MAY AWAIT FURTHER BOUNDARY LAYER
DESTABILIZATION AND WEAKENING INHIBITION ACROSS IOWA NORTHWARD INTO
PARTS OF MINNESOTA AND WISCONSIN LATER TODAY.

THE PRIMARY SEVERE WEATHER POTENTIAL IS EXPECTED TO DEVELOP IN THE
WAKE OF THIS INITIAL IMPULSE...AS ANOTHER CONTINUES TO PIVOT EAST OF
THE CENTRAL HIGH PLAINS THIS AFTERNOON.  THIS SEEMS MOST LIKELY TO
BECOME FOCUSED ALONG/SOUTH AND EAST OF A REMNANT CONVECTIVELY
GENERATED BOUNDARY THAT CURRENTLY CURVES FROM THE MISSOURI OZARKS
INTO NORTHERN OKLAHOMA.  A NORTHWARD RETREAT OF THIS BOUNDARY INTO
SOUTHERN KANSAS IS STILL EXPECTED...AND LATEST HIGH RESOLUTION RAPID
REFRESH APPEARS REASONABLE SUGGESTING INITIATION OF STORMS ALONG THE
INTERSECTION OF THIS BOUNDARY AND AN EASTWARD ADVANCING
DRYLINE...ACROSS NORTH CENTRAL OKLAHOMA OR SOUTH CENTRAL KANSAS...BY
19-20Z.

AIDED BY FORCING IN THE EXIT REGION OF A MID-LEVEL SPEED MAXIMUM
NOSING NORTHEASTWARD ACROSS THE SOUTH CENTRAL PLAINS...UPSCALE
CONVECTIVE GROWTH INTO A SUBSTANTIAL MESOSCALE CONVECTIVE SYSTEM IS
EXPECTED LATE THIS AFTERNOON AND EVENING.  IN THE PRESENCE OF STRONG
DEEP LAYER SHEAR...40-50 KT SOUTHERLY 850 MB FLOW NEAR AND SOUTH OF
THE CONVECTIVE BOUNDARY WILL CONTRIBUTE TO SIZABLE CLOCKWISE CURVED
LOW-LEVEL HODOGRAPHS SUPPORTIVE OF THE RISK FOR TORNADOES.  HIGHEST
PROBABILITIES FOR TORNADOES...SOME POSSIBLY STRONG...MAY BE
SUPERCELLS ON THE SOUTHERN FLANK OF THE EVOLVING CONVECTIVE
SYSTEM...ACROSS SOUTHEAST KANSAS INTO PARTS OF WEST
CENTRAL/SOUTHEAST MISSOURI...AS WELL AS WITH STORMS INITIATING AND
ADVANCING NORTHEASTWARD OFF THE DRYLINE...ACROSS NORTHEASTERN
OKLAHOMA.  FURTHER STRENGTHENING OF THE 850 MB JET ACROSS EASTERN
OKLAHOMA INTO SOUTHWEST MISSOURI WILL MAINTAIN TORNADIC POTENTIAL
WELL INTO THE EVENING HOURS...WITH ONE OR TWO LONG-LIVED TORNADIC
SUPERCELLS POSSIBLE.

000
ACUS11 KWNS 191845
SWOMCD
SPC MCD 191845
OKZ000-191945-

MESOSCALE DISCUSSION 0698
NWS STORM PREDICTION CENTER NORMAN OK
0145 PM CDT SUN MAY 19 2013

AREAS AFFECTED...NRN...CNTRL...AND SRN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191845Z - 191945Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...TSTM INITIATION APPEARS INCREASINGLY PROBABLE OVER THE
NEXT 1-2 HRS ACROSS NRN/CNTRL OK. STORMS SHOULD QUICKLY INTENSIFY
AND POSE A THREAT FOR VERY LARGE HAIL...DMGG WINDS...AND A FEW
TORNADOES. A TORNADO WATCH WILL LIKELY BE NEEDED IN THE NEXT HOUR OR
SO.

DISCUSSION...SFC ANALYSIS FROM 18Z SHOWS A DRYLINE RAPIDLY MIXING
EWD ACROSS WRN OK...ATTENDANT TO A DEEPENING SFC LOW OVER NWRN
OK...WITH UPPER 60S TO LOWER 70S F DEWPOINTS WIDESPREAD ACROSS CNTRL
OK. A REMNANT OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION REMAINS
DRAPED ACROSS FAR NRN OK...BUT UNIFORM SLY WINDS WERE NOTED ON BOTH
SIDES OF THIS BOUNDARY. MEANWHILE...AN INCREASINGLY AGITATED LINE OF
CU WAS NOTED PRECEDING THE DRYLINE...ORIENTED SW-NE FROM NEAR A 30 E
CSM TO 15 NW END LINE...WITHIN A ZONE OF WEAK LOW-LEVEL CONVERGENCE.
THIS AREA APPEARS TO BE THE MOST LIKELY FOCUS FOR INITIAL CONVECTIVE
DEVELOPMENT THIS AFTERNOON...AS A PROGRESSIVE UPPER IMPULSE
CURRENTLY POSITIONED OVER THE OK AND NRN TX PANHANDLES SHOULD
CONTINUE EWD NEAR THE OK/KS BORDER.

STRONG SFC HEATING IS UNDERWAY ACROSS MOST OF OK...WITH BOUNDARY
LAYER CU FORMING MORE RECENTLY BUT STILL EXHIBITING CAPPED/FLAT
CHARACTER. PERSISTENT CONVERGENCE ALONG THE DRYLINE...ALONG WITH
FURTHER BOUNDARY LAYER HEATING WITH TEMPERATURES REACHING THE UPPER
80S/LOWER 90S F WITHIN THE MOIST AIR...SHOULD RESULT IN EROSION OF
THE SIGNIFICANT CAPPING INVERSION NOTED IN THE 18Z OUN SOUNDING. AS
THIS OCCURS...DISCRETE TSTM DEVELOPMENT ALONG THE DRYLINE APPEARS
LIKELY...WITH AN ACCOMPANYING THREAT FOR LARGE HAIL AND DMGG WINDS.
TORNADO POTENTIAL SHOULD STEADILY INCREASE THROUGH THE LATE
AFTERNOON/EVENING ACCOMPANYING SUSTAINED SUPERCELLS...AS WIND
PROFILES CONTINUE TO STRENGTHEN.

RECENT SUITE OF HIGH-RESOLUTION MODEL GUIDANCE INDICATES CONVECTION
SHOULD INITIATE ACROSS THE NRN HALF OF THE HIGHLIGHTED AREA BETWEEN
20-21Z...AND PERHAPS AFTER 21Z ACROSS SWRN/S-CNTRL OK. A TORNADO
WATCH WILL LIKELY BE ISSUED WITHIN THE NEXT HOUR.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   36889595 36339551 35369631 34689650 34089664 34039693
            34159782 34259839 35169859 35709863 36119865 36579845
            36789840 36789713 36889595

000
ACUS11 KWNS 191845
SWOMCD
SPC MCD 191845
OKZ000-191945-

MESOSCALE DISCUSSION 0698
NWS STORM PREDICTION CENTER NORMAN OK
0145 PM CDT SUN MAY 19 2013

AREAS AFFECTED...NRN...CNTRL...AND SRN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191845Z - 191945Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...TSTM INITIATION APPEARS INCREASINGLY PROBABLE OVER THE
NEXT 1-2 HRS ACROSS NRN/CNTRL OK. STORMS SHOULD QUICKLY INTENSIFY
AND POSE A THREAT FOR VERY LARGE HAIL...DMGG WINDS...AND A FEW
TORNADOES. A TORNADO WATCH WILL LIKELY BE NEEDED IN THE NEXT HOUR OR
SO.

DISCUSSION...SFC ANALYSIS FROM 18Z SHOWS A DRYLINE RAPIDLY MIXING
EWD ACROSS WRN OK...ATTENDANT TO A DEEPENING SFC LOW OVER NWRN
OK...WITH UPPER 60S TO LOWER 70S F DEWPOINTS WIDESPREAD ACROSS CNTRL
OK. A REMNANT OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION REMAINS
DRAPED ACROSS FAR NRN OK...BUT UNIFORM SLY WINDS WERE NOTED ON BOTH
SIDES OF THIS BOUNDARY. MEANWHILE...AN INCREASINGLY AGITATED LINE OF
CU WAS NOTED PRECEDING THE DRYLINE...ORIENTED SW-NE FROM NEAR A 30 E
CSM TO 15 NW END LINE...WITHIN A ZONE OF WEAK LOW-LEVEL CONVERGENCE.
THIS AREA APPEARS TO BE THE MOST LIKELY FOCUS FOR INITIAL CONVECTIVE
DEVELOPMENT THIS AFTERNOON...AS A PROGRESSIVE UPPER IMPULSE
CURRENTLY POSITIONED OVER THE OK AND NRN TX PANHANDLES SHOULD
CONTINUE EWD NEAR THE OK/KS BORDER.

STRONG SFC HEATING IS UNDERWAY ACROSS MOST OF OK...WITH BOUNDARY
LAYER CU FORMING MORE RECENTLY BUT STILL EXHIBITING CAPPED/FLAT
CHARACTER. PERSISTENT CONVERGENCE ALONG THE DRYLINE...ALONG WITH
FURTHER BOUNDARY LAYER HEATING WITH TEMPERATURES REACHING THE UPPER
80S/LOWER 90S F WITHIN THE MOIST AIR...SHOULD RESULT IN EROSION OF
THE SIGNIFICANT CAPPING INVERSION NOTED IN THE 18Z OUN SOUNDING. AS
THIS OCCURS...DISCRETE TSTM DEVELOPMENT ALONG THE DRYLINE APPEARS
LIKELY...WITH AN ACCOMPANYING THREAT FOR LARGE HAIL AND DMGG WINDS.
TORNADO POTENTIAL SHOULD STEADILY INCREASE THROUGH THE LATE
AFTERNOON/EVENING ACCOMPANYING SUSTAINED SUPERCELLS...AS WIND
PROFILES CONTINUE TO STRENGTHEN.

RECENT SUITE OF HIGH-RESOLUTION MODEL GUIDANCE INDICATES CONVECTION
SHOULD INITIATE ACROSS THE NRN HALF OF THE HIGHLIGHTED AREA BETWEEN
20-21Z...AND PERHAPS AFTER 21Z ACROSS SWRN/S-CNTRL OK. A TORNADO
WATCH WILL LIKELY BE ISSUED WITHIN THE NEXT HOUR.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   36889595 36339551 35369631 34689650 34089664 34039693
            34159782 34259839 35169859 35709863 36119865 36579845
            36789840 36789713 36889595

000
ACUS11 KWNS 191845
SWOMCD
SPC MCD 191845
OKZ000-191945-

MESOSCALE DISCUSSION 0698
NWS STORM PREDICTION CENTER NORMAN OK
0145 PM CDT SUN MAY 19 2013

AREAS AFFECTED...NRN...CNTRL...AND SRN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191845Z - 191945Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...TSTM INITIATION APPEARS INCREASINGLY PROBABLE OVER THE
NEXT 1-2 HRS ACROSS NRN/CNTRL OK. STORMS SHOULD QUICKLY INTENSIFY
AND POSE A THREAT FOR VERY LARGE HAIL...DMGG WINDS...AND A FEW
TORNADOES. A TORNADO WATCH WILL LIKELY BE NEEDED IN THE NEXT HOUR OR
SO.

DISCUSSION...SFC ANALYSIS FROM 18Z SHOWS A DRYLINE RAPIDLY MIXING
EWD ACROSS WRN OK...ATTENDANT TO A DEEPENING SFC LOW OVER NWRN
OK...WITH UPPER 60S TO LOWER 70S F DEWPOINTS WIDESPREAD ACROSS CNTRL
OK. A REMNANT OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION REMAINS
DRAPED ACROSS FAR NRN OK...BUT UNIFORM SLY WINDS WERE NOTED ON BOTH
SIDES OF THIS BOUNDARY. MEANWHILE...AN INCREASINGLY AGITATED LINE OF
CU WAS NOTED PRECEDING THE DRYLINE...ORIENTED SW-NE FROM NEAR A 30 E
CSM TO 15 NW END LINE...WITHIN A ZONE OF WEAK LOW-LEVEL CONVERGENCE.
THIS AREA APPEARS TO BE THE MOST LIKELY FOCUS FOR INITIAL CONVECTIVE
DEVELOPMENT THIS AFTERNOON...AS A PROGRESSIVE UPPER IMPULSE
CURRENTLY POSITIONED OVER THE OK AND NRN TX PANHANDLES SHOULD
CONTINUE EWD NEAR THE OK/KS BORDER.

STRONG SFC HEATING IS UNDERWAY ACROSS MOST OF OK...WITH BOUNDARY
LAYER CU FORMING MORE RECENTLY BUT STILL EXHIBITING CAPPED/FLAT
CHARACTER. PERSISTENT CONVERGENCE ALONG THE DRYLINE...ALONG WITH
FURTHER BOUNDARY LAYER HEATING WITH TEMPERATURES REACHING THE UPPER
80S/LOWER 90S F WITHIN THE MOIST AIR...SHOULD RESULT IN EROSION OF
THE SIGNIFICANT CAPPING INVERSION NOTED IN THE 18Z OUN SOUNDING. AS
THIS OCCURS...DISCRETE TSTM DEVELOPMENT ALONG THE DRYLINE APPEARS
LIKELY...WITH AN ACCOMPANYING THREAT FOR LARGE HAIL AND DMGG WINDS.
TORNADO POTENTIAL SHOULD STEADILY INCREASE THROUGH THE LATE
AFTERNOON/EVENING ACCOMPANYING SUSTAINED SUPERCELLS...AS WIND
PROFILES CONTINUE TO STRENGTHEN.

RECENT SUITE OF HIGH-RESOLUTION MODEL GUIDANCE INDICATES CONVECTION
SHOULD INITIATE ACROSS THE NRN HALF OF THE HIGHLIGHTED AREA BETWEEN
20-21Z...AND PERHAPS AFTER 21Z ACROSS SWRN/S-CNTRL OK. A TORNADO
WATCH WILL LIKELY BE ISSUED WITHIN THE NEXT HOUR.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   36889595 36339551 35369631 34689650 34089664 34039693
            34159782 34259839 35169859 35709863 36119865 36579845
            36789840 36789713 36889595

000
ACUS11 KWNS 191752
SWOMCD
SPC MCD 191751
MOZ000-KSZ000-OKZ000-NEZ000-191945-

MESOSCALE DISCUSSION 0697
NWS STORM PREDICTION CENTER NORMAN OK
1251 PM CDT SUN MAY 19 2013

AREAS AFFECTED...NRN OK...SCNTRL THROUGH ERN KS...EXTREME SERN NEB
AND WRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191751Z - 191945Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP BY 20Z...MOST LIKELY OVER
SCNTRL KS INTO NCNTRL OK. STORMS WILL SUBSEQUENTLY CONTINUE THROUGH
THE WARM SECTOR OVER ERN KS...NERN OK AND EVENTUALLY WRN MO THIS
EVENING. INITIAL THREATS WILL BE SUPERCELLS WITH VERY LARGE HAIL AND
TORNADOES...A FEW OF WHICH COULD BE STRONG.

DISCUSSION...EARLY THIS AFTERNOON A DRYLINE EXTENDS FROM WRN TX INTO
FAR WRN OK THEN NWWD INTO THE OK PANHANDLE WHERE IT INTERSECTS A
COLD FRONT. A WEAKENING OUTFLOW BOUNDARY EXISTS NEAR THE OK/KS
BORDER AND HAS BEEN LIFTING SLOWLY NWD. SATELLITE IMAGERY ALSO
INDICATES AN EWD PROPAGATING GRAVITY WAVE FROM SCNTRL KS INTO NWRN
OK. UPPER 60S DEWPOINTS ARE ADVECTING NWD THROUGH THE WARM SECTOR
BENEATH VERY STEEP /8-9 C/KM/ MID LEVEL LAPSE RATES. THESE FACTORS
ALONG WITH DIABATIC WARMING WILL CONTRIBUTE TO STRONG INSTABILITY
WITH 3000-4000 J/KG MLCAPE BY MID AFTERNOON. WARM AIR AT THE BASE OF
THE EML IS SERVING TO CAP THE BOUNDARY LAYER TO SFC BASED STORMS IN
THE NEAR TERM. HOWEVER...MESOSCALE FORCING FOR ASCENT ASSOCIATED
WITH EWD PROPAGATING GRAVITY WAVE LOCATED WITHIN UPPER JET EXIT
REGION AS WELL AS DRYLINE CONVERGENCE SHOULD CONTRIBUTE TO
THUNDERSTORM INITIATION AS CONVECTIVE TEMPERATURES ARE REACHED
TOWARD MID-LATE AFTERNOON.

MID-UPPER JET ROTATING THROUGH BASE OF THE TROUGH IS RESULTING IN
50+ KT DEEP SHEAR SUPPORTIVE OF SUPERCELLS. 0-2 KM HODOGRAPHS WILL
ALSO BE SUFFICIENT FOR LOW LEVEL MESOCYCLONES...AND THREAT FOR A FEW
STRONG TORNADOES WILL EXIST GIVEN THE STEEP LAPSE RATES AND
MAGNITUDE OF INSTABILITY.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT...OUN...DDC...

LAT...LON   36539841 37939876 40319628 39659446 36729528 36539841

000
ACUS11 KWNS 191752
SWOMCD
SPC MCD 191751
MOZ000-KSZ000-OKZ000-NEZ000-191945-

MESOSCALE DISCUSSION 0697
NWS STORM PREDICTION CENTER NORMAN OK
1251 PM CDT SUN MAY 19 2013

AREAS AFFECTED...NRN OK...SCNTRL THROUGH ERN KS...EXTREME SERN NEB
AND WRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191751Z - 191945Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP BY 20Z...MOST LIKELY OVER
SCNTRL KS INTO NCNTRL OK. STORMS WILL SUBSEQUENTLY CONTINUE THROUGH
THE WARM SECTOR OVER ERN KS...NERN OK AND EVENTUALLY WRN MO THIS
EVENING. INITIAL THREATS WILL BE SUPERCELLS WITH VERY LARGE HAIL AND
TORNADOES...A FEW OF WHICH COULD BE STRONG.

DISCUSSION...EARLY THIS AFTERNOON A DRYLINE EXTENDS FROM WRN TX INTO
FAR WRN OK THEN NWWD INTO THE OK PANHANDLE WHERE IT INTERSECTS A
COLD FRONT. A WEAKENING OUTFLOW BOUNDARY EXISTS NEAR THE OK/KS
BORDER AND HAS BEEN LIFTING SLOWLY NWD. SATELLITE IMAGERY ALSO
INDICATES AN EWD PROPAGATING GRAVITY WAVE FROM SCNTRL KS INTO NWRN
OK. UPPER 60S DEWPOINTS ARE ADVECTING NWD THROUGH THE WARM SECTOR
BENEATH VERY STEEP /8-9 C/KM/ MID LEVEL LAPSE RATES. THESE FACTORS
ALONG WITH DIABATIC WARMING WILL CONTRIBUTE TO STRONG INSTABILITY
WITH 3000-4000 J/KG MLCAPE BY MID AFTERNOON. WARM AIR AT THE BASE OF
THE EML IS SERVING TO CAP THE BOUNDARY LAYER TO SFC BASED STORMS IN
THE NEAR TERM. HOWEVER...MESOSCALE FORCING FOR ASCENT ASSOCIATED
WITH EWD PROPAGATING GRAVITY WAVE LOCATED WITHIN UPPER JET EXIT
REGION AS WELL AS DRYLINE CONVERGENCE SHOULD CONTRIBUTE TO
THUNDERSTORM INITIATION AS CONVECTIVE TEMPERATURES ARE REACHED
TOWARD MID-LATE AFTERNOON.

MID-UPPER JET ROTATING THROUGH BASE OF THE TROUGH IS RESULTING IN
50+ KT DEEP SHEAR SUPPORTIVE OF SUPERCELLS. 0-2 KM HODOGRAPHS WILL
ALSO BE SUFFICIENT FOR LOW LEVEL MESOCYCLONES...AND THREAT FOR A FEW
STRONG TORNADOES WILL EXIST GIVEN THE STEEP LAPSE RATES AND
MAGNITUDE OF INSTABILITY.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT...OUN...DDC...

LAT...LON   36539841 37939876 40319628 39659446 36729528 36539841

000
ACUS11 KWNS 191752
SWOMCD
SPC MCD 191751
MOZ000-KSZ000-OKZ000-NEZ000-191945-

MESOSCALE DISCUSSION 0697
NWS STORM PREDICTION CENTER NORMAN OK
1251 PM CDT SUN MAY 19 2013

AREAS AFFECTED...NRN OK...SCNTRL THROUGH ERN KS...EXTREME SERN NEB
AND WRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191751Z - 191945Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP BY 20Z...MOST LIKELY OVER
SCNTRL KS INTO NCNTRL OK. STORMS WILL SUBSEQUENTLY CONTINUE THROUGH
THE WARM SECTOR OVER ERN KS...NERN OK AND EVENTUALLY WRN MO THIS
EVENING. INITIAL THREATS WILL BE SUPERCELLS WITH VERY LARGE HAIL AND
TORNADOES...A FEW OF WHICH COULD BE STRONG.

DISCUSSION...EARLY THIS AFTERNOON A DRYLINE EXTENDS FROM WRN TX INTO
FAR WRN OK THEN NWWD INTO THE OK PANHANDLE WHERE IT INTERSECTS A
COLD FRONT. A WEAKENING OUTFLOW BOUNDARY EXISTS NEAR THE OK/KS
BORDER AND HAS BEEN LIFTING SLOWLY NWD. SATELLITE IMAGERY ALSO
INDICATES AN EWD PROPAGATING GRAVITY WAVE FROM SCNTRL KS INTO NWRN
OK. UPPER 60S DEWPOINTS ARE ADVECTING NWD THROUGH THE WARM SECTOR
BENEATH VERY STEEP /8-9 C/KM/ MID LEVEL LAPSE RATES. THESE FACTORS
ALONG WITH DIABATIC WARMING WILL CONTRIBUTE TO STRONG INSTABILITY
WITH 3000-4000 J/KG MLCAPE BY MID AFTERNOON. WARM AIR AT THE BASE OF
THE EML IS SERVING TO CAP THE BOUNDARY LAYER TO SFC BASED STORMS IN
THE NEAR TERM. HOWEVER...MESOSCALE FORCING FOR ASCENT ASSOCIATED
WITH EWD PROPAGATING GRAVITY WAVE LOCATED WITHIN UPPER JET EXIT
REGION AS WELL AS DRYLINE CONVERGENCE SHOULD CONTRIBUTE TO
THUNDERSTORM INITIATION AS CONVECTIVE TEMPERATURES ARE REACHED
TOWARD MID-LATE AFTERNOON.

MID-UPPER JET ROTATING THROUGH BASE OF THE TROUGH IS RESULTING IN
50+ KT DEEP SHEAR SUPPORTIVE OF SUPERCELLS. 0-2 KM HODOGRAPHS WILL
ALSO BE SUFFICIENT FOR LOW LEVEL MESOCYCLONES...AND THREAT FOR A FEW
STRONG TORNADOES WILL EXIST GIVEN THE STEEP LAPSE RATES AND
MAGNITUDE OF INSTABILITY.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TSA...OAX...TOP...ICT...OUN...DDC...

LAT...LON   36539841 37939876 40319628 39659446 36729528 36539841

000
ACUS02 KWNS 191729
SWODY2
SPC AC 191728

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT SUN MAY 19 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS OK...SERN KS...EXTREME
NWRN AR...AND SWRN MO...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
SWRN TX TO THE UPPER GREAT LAKES...

...SOUTHERN PLAINS TO MID MS VALLEY...

SECONDARY MID LEVEL SPEED MAX...ON THE ORDER OF 60KT AT 500 MB...IS
EXPECTED TO EJECT ACROSS THE SRN ROCKIES INTO NRN OK BY 21/00Z.
WHILE LATE DAY1 CONVECTION MAY DISTURB LOW LEVEL WIND FIELDS ACROSS
PORTIONS OF SERN KS INTO MO...IT APPEARS LARGE SCALE INFLUENCE OF
APPROACHING SPEED MAX SHOULD SHARPEN SYNOPTIC FRONT ACROSS OK BY
PEAK HEATING.  THIS WILL BE THE PRIMARY FOCUS FOR RENEWED SEVERE
THUNDERSTORM DEVELOPMENT ACROSS THE MDT RISK REGION.

THUNDERSTORMS...A FEW SEVERE WITH A THREAT OF HAIL...MAY BE ONGOING
AT THE BEGINNING OF THE PERIOD ACROSS SERN KS/MO ALONG THE NOSE OF
VEERED LLJ.  THIS CONVECTION MAY TEMPORARILY DISPLACE THE SYNOPTIC
FRONT OR PERHAPS EVEN PRODUCE OUTFLOW THAT BECOMES A FOCUS FOR
AFTERNOON CONVECTIVE DEVELOPMENT.  STRONGEST BOUNDARY LAYER HEATING
IS EXPECTED ACROSS WEST TX INTO SWRN OK WHERE SFC TEMPERATURES
SHOULD SOAR INTO THE 90S.  ALONG/NORTH OF THE MAIN MID LEVEL JET
CORE MID LEVEL TEMPERATURES SHOULD COOL SUCH THAT DEEP CONVECTION
WILL EASILY DEVELOP ALONG AFOREMENTIONED CONVECTIVE OUTFLOW BOUNDARY
INTO MO AND SHARPENING COLD FRONT/DRYLINE FARTHER WEST.  IN
FACT...TSTMS MAY DEVELOP BY 20-21Z ACROSS OK WHERE SBCAPE IS
EXPECTED TO BE IN EXCESS OF 3000 J/KG.  FORECAST DEEP LAYER
SHEAR...IN EXCESS OF 50KT THROUGH 6KM...AND THE PROSPECT FOR A VERY
MOIST WARM SECTOR FAVOR NUMEROUS SUPERCELL STRUCTURES...AT LEAST
THROUGH MID EVENING OF THE CONVECTIVE CYCLE.  VERY LARGE HAIL AND
TORNADOES ARE POSSIBLE WITH SUPERCELLS AND WITH TIME ONE OR MORE
MCS/S SHOULD EVOLVE ALONG NOSE OF STRENGTHENING LLJ OVER OK.  AMPLE
MID LEVEL FLOW WILL EXTEND ALONG THE DRYLINE INTO THE EDWARDS
PLATEAU OF TX SUPPORTIVE OF ISOLATED SUPERCELL STRUCTURES CAPABLE OF
PRODUCING AT LEAST LARGE HAIL AND DAMAGING WINDS.


...UPPER MS VALLEY/GREAT LAKES...

LATEST MODEL GUIDANCE SUGGESTS A MID LEVEL SHORT WAVE TROUGH/SPEED
MAX WILL ROTATE NEWD ACROSS IA/IL INTO MN/WI DURING THE AFTERNOON
HOURS.  THIS FEATURE WILL SERVE TO INCREASE UVV ACROSS A FAIRLY
MOIST/UNSTABLE BOUNDARY LAYER SOUTH OF SHARP WARM FRONT THAT WILL
EXTEND FROM LOW NEAR THE ND/SD/MN BORDER...EWD INTO NRN WI AT PEAK
HEATING.  WHILE SHORT WAVE TROUGH WILL INFLUENCE/SUPPORT DEEP
CONVECTION...STRONG BOUNDARY LAYER HEATING WILL PROVE INSTRUMENTAL
IN DESTABILIZATION ACROSS MN/WI AND SBCAPE COULD EASILY RISE TO NEAR
2000 J/KG.  DISCRETE SUPERCELL STRUCTURES MAY EVOLVE WITHIN THIS
AIRMASS AND WITH RELATIVELY LOW CLOUD BASES ISOLATED TORNADOES...IN
ADDITION TO LARGE HAIL MAY BE OBSERVED.

..DARROW.. 05/19/2013

000
ACUS02 KWNS 191729
SWODY2
SPC AC 191728

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT SUN MAY 19 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS OK...SERN KS...EXTREME
NWRN AR...AND SWRN MO...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
SWRN TX TO THE UPPER GREAT LAKES...

...SOUTHERN PLAINS TO MID MS VALLEY...

SECONDARY MID LEVEL SPEED MAX...ON THE ORDER OF 60KT AT 500 MB...IS
EXPECTED TO EJECT ACROSS THE SRN ROCKIES INTO NRN OK BY 21/00Z.
WHILE LATE DAY1 CONVECTION MAY DISTURB LOW LEVEL WIND FIELDS ACROSS
PORTIONS OF SERN KS INTO MO...IT APPEARS LARGE SCALE INFLUENCE OF
APPROACHING SPEED MAX SHOULD SHARPEN SYNOPTIC FRONT ACROSS OK BY
PEAK HEATING.  THIS WILL BE THE PRIMARY FOCUS FOR RENEWED SEVERE
THUNDERSTORM DEVELOPMENT ACROSS THE MDT RISK REGION.

THUNDERSTORMS...A FEW SEVERE WITH A THREAT OF HAIL...MAY BE ONGOING
AT THE BEGINNING OF THE PERIOD ACROSS SERN KS/MO ALONG THE NOSE OF
VEERED LLJ.  THIS CONVECTION MAY TEMPORARILY DISPLACE THE SYNOPTIC
FRONT OR PERHAPS EVEN PRODUCE OUTFLOW THAT BECOMES A FOCUS FOR
AFTERNOON CONVECTIVE DEVELOPMENT.  STRONGEST BOUNDARY LAYER HEATING
IS EXPECTED ACROSS WEST TX INTO SWRN OK WHERE SFC TEMPERATURES
SHOULD SOAR INTO THE 90S.  ALONG/NORTH OF THE MAIN MID LEVEL JET
CORE MID LEVEL TEMPERATURES SHOULD COOL SUCH THAT DEEP CONVECTION
WILL EASILY DEVELOP ALONG AFOREMENTIONED CONVECTIVE OUTFLOW BOUNDARY
INTO MO AND SHARPENING COLD FRONT/DRYLINE FARTHER WEST.  IN
FACT...TSTMS MAY DEVELOP BY 20-21Z ACROSS OK WHERE SBCAPE IS
EXPECTED TO BE IN EXCESS OF 3000 J/KG.  FORECAST DEEP LAYER
SHEAR...IN EXCESS OF 50KT THROUGH 6KM...AND THE PROSPECT FOR A VERY
MOIST WARM SECTOR FAVOR NUMEROUS SUPERCELL STRUCTURES...AT LEAST
THROUGH MID EVENING OF THE CONVECTIVE CYCLE.  VERY LARGE HAIL AND
TORNADOES ARE POSSIBLE WITH SUPERCELLS AND WITH TIME ONE OR MORE
MCS/S SHOULD EVOLVE ALONG NOSE OF STRENGTHENING LLJ OVER OK.  AMPLE
MID LEVEL FLOW WILL EXTEND ALONG THE DRYLINE INTO THE EDWARDS
PLATEAU OF TX SUPPORTIVE OF ISOLATED SUPERCELL STRUCTURES CAPABLE OF
PRODUCING AT LEAST LARGE HAIL AND DAMAGING WINDS.


...UPPER MS VALLEY/GREAT LAKES...

LATEST MODEL GUIDANCE SUGGESTS A MID LEVEL SHORT WAVE TROUGH/SPEED
MAX WILL ROTATE NEWD ACROSS IA/IL INTO MN/WI DURING THE AFTERNOON
HOURS.  THIS FEATURE WILL SERVE TO INCREASE UVV ACROSS A FAIRLY
MOIST/UNSTABLE BOUNDARY LAYER SOUTH OF SHARP WARM FRONT THAT WILL
EXTEND FROM LOW NEAR THE ND/SD/MN BORDER...EWD INTO NRN WI AT PEAK
HEATING.  WHILE SHORT WAVE TROUGH WILL INFLUENCE/SUPPORT DEEP
CONVECTION...STRONG BOUNDARY LAYER HEATING WILL PROVE INSTRUMENTAL
IN DESTABILIZATION ACROSS MN/WI AND SBCAPE COULD EASILY RISE TO NEAR
2000 J/KG.  DISCRETE SUPERCELL STRUCTURES MAY EVOLVE WITHIN THIS
AIRMASS AND WITH RELATIVELY LOW CLOUD BASES ISOLATED TORNADOES...IN
ADDITION TO LARGE HAIL MAY BE OBSERVED.

..DARROW.. 05/19/2013

000
ACUS11 KWNS 191636
SWOMCD
SPC MCD 191635
GAZ000-FLZ000-ALZ000-191730-

MESOSCALE DISCUSSION 0696
NWS STORM PREDICTION CENTER NORMAN OK
1135 AM CDT SUN MAY 19 2013

AREAS AFFECTED...W-CNTRL AND SWRN GA....NRN FL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191635Z - 191730Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...A THREAT FOR DMGG WINDS MAY ACCOMPANY A SWD SURGING LINE
OF STORMS/COLD POOL MOVING THROUGH NW GA. STRONG
HEATING/DESTABILIZATION DOWNSTREAM FROM THESE STORMS SUGGEST THE
THREAT COULD EXTEND INTO W-CNTRL AND SWRN GA THIS AFTERNOON. A WW
WILL LIKELY BE COORDINATED SOON WITH AFFECTED FORECAST OFFICES.

DISCUSSION...RADAR TRENDS SHOW AN ORGANIZING LINE OF TSTMS W OF
ATLANTA AS OF 1630 Z...WITH A SWD SURGING COLD POOL NOTED MORE
RECENTLY. THIS IS DEVELOPING WITHIN A ZONE OF 25-35 KTS OF MIDLEVEL
FLOW /SEE 12Z FFC SOUNDING/...BUT RELATIVELY WEAK LOW-LEVEL FLOW.
RICH BOUNDARY LAYER MOISTURE AND STRONG HEATING ARE OCCURRING S OF
THIS LINE...CONTRIBUTING TO MLCAPE VALUES OF 1000-1500 J/KG
DOWNSTREAM. WITH STEEPENING LOW-LEVEL LAPSE RATES...POTENTIAL FOR
SVR WIND GUSTS SHOULD SEEMINGLY INCREASE ACROSS W-CNTRL GA...AND
PERHAPS SWRN GA IF LINE CAN MAINTAIN ORGANIZATION INTO THE
AFTERNOON.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...JAX...FFC...TAE...BMX...

LAT...LON   33098511 33488512 33678472 33618445 33028401 32308355
            31808327 31388302 30798290 30508324 30528422 31608475
            33098511

000
ACUS11 KWNS 191636
SWOMCD
SPC MCD 191635
GAZ000-FLZ000-ALZ000-191730-

MESOSCALE DISCUSSION 0696
NWS STORM PREDICTION CENTER NORMAN OK
1135 AM CDT SUN MAY 19 2013

AREAS AFFECTED...W-CNTRL AND SWRN GA....NRN FL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191635Z - 191730Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...A THREAT FOR DMGG WINDS MAY ACCOMPANY A SWD SURGING LINE
OF STORMS/COLD POOL MOVING THROUGH NW GA. STRONG
HEATING/DESTABILIZATION DOWNSTREAM FROM THESE STORMS SUGGEST THE
THREAT COULD EXTEND INTO W-CNTRL AND SWRN GA THIS AFTERNOON. A WW
WILL LIKELY BE COORDINATED SOON WITH AFFECTED FORECAST OFFICES.

DISCUSSION...RADAR TRENDS SHOW AN ORGANIZING LINE OF TSTMS W OF
ATLANTA AS OF 1630 Z...WITH A SWD SURGING COLD POOL NOTED MORE
RECENTLY. THIS IS DEVELOPING WITHIN A ZONE OF 25-35 KTS OF MIDLEVEL
FLOW /SEE 12Z FFC SOUNDING/...BUT RELATIVELY WEAK LOW-LEVEL FLOW.
RICH BOUNDARY LAYER MOISTURE AND STRONG HEATING ARE OCCURRING S OF
THIS LINE...CONTRIBUTING TO MLCAPE VALUES OF 1000-1500 J/KG
DOWNSTREAM. WITH STEEPENING LOW-LEVEL LAPSE RATES...POTENTIAL FOR
SVR WIND GUSTS SHOULD SEEMINGLY INCREASE ACROSS W-CNTRL GA...AND
PERHAPS SWRN GA IF LINE CAN MAINTAIN ORGANIZATION INTO THE
AFTERNOON.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...JAX...FFC...TAE...BMX...

LAT...LON   33098511 33488512 33678472 33618445 33028401 32308355
            31808327 31388302 30798290 30508324 30528422 31608475
            33098511

000
ACUS11 KWNS 191636
SWOMCD
SPC MCD 191635
GAZ000-FLZ000-ALZ000-191730-

MESOSCALE DISCUSSION 0696
NWS STORM PREDICTION CENTER NORMAN OK
1135 AM CDT SUN MAY 19 2013

AREAS AFFECTED...W-CNTRL AND SWRN GA....NRN FL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 191635Z - 191730Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...A THREAT FOR DMGG WINDS MAY ACCOMPANY A SWD SURGING LINE
OF STORMS/COLD POOL MOVING THROUGH NW GA. STRONG
HEATING/DESTABILIZATION DOWNSTREAM FROM THESE STORMS SUGGEST THE
THREAT COULD EXTEND INTO W-CNTRL AND SWRN GA THIS AFTERNOON. A WW
WILL LIKELY BE COORDINATED SOON WITH AFFECTED FORECAST OFFICES.

DISCUSSION...RADAR TRENDS SHOW AN ORGANIZING LINE OF TSTMS W OF
ATLANTA AS OF 1630 Z...WITH A SWD SURGING COLD POOL NOTED MORE
RECENTLY. THIS IS DEVELOPING WITHIN A ZONE OF 25-35 KTS OF MIDLEVEL
FLOW /SEE 12Z FFC SOUNDING/...BUT RELATIVELY WEAK LOW-LEVEL FLOW.
RICH BOUNDARY LAYER MOISTURE AND STRONG HEATING ARE OCCURRING S OF
THIS LINE...CONTRIBUTING TO MLCAPE VALUES OF 1000-1500 J/KG
DOWNSTREAM. WITH STEEPENING LOW-LEVEL LAPSE RATES...POTENTIAL FOR
SVR WIND GUSTS SHOULD SEEMINGLY INCREASE ACROSS W-CNTRL GA...AND
PERHAPS SWRN GA IF LINE CAN MAINTAIN ORGANIZATION INTO THE
AFTERNOON.

..ROGERS/KERR.. 05/19/2013

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

ATTN...WFO...JAX...FFC...TAE...BMX...

LAT...LON   33098511 33488512 33678472 33618445 33028401 32308355
            31808327 31388302 30798290 30508324 30528422 31608475
            33098511

000
ACUS11 KWNS 191630
SWOMCD
SPC MCD 191630
IAZ000-ILZ000-MNZ000-MOZ000-191800-

MESOSCALE DISCUSSION 0695
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT SUN MAY 19 2013

AREAS AFFECTED...NERN MO...ERN IA...AND SERN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 191630Z - 191800Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
OVER THE MID-UPPER MS VALLEY REGION DURING EARLY-MID AFTERNOON.
POTENTIAL WILL EXIST FOR ORGANIZED MULTICELLS AS WELL AS A FEW
SUPERCELLS. MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WIND...BUT
A COUPLE TORNADOES MAY ALSO BE POSSIBLE. A WW MIGHT BE NEEDED BEFORE
18Z.

DISCUSSION...LATE THIS MORNING WELL DEFINED MCV WAS LOCATED OVER
SWRN IA LIFTING NEWD. ELEVATED STORMS CURRENTLY DEVELOPING OVER ERN
IA INTO WRN IL MAY POSE A THREAT FOR HAIL. THESE STORMS MAY
INTENSIFY FURTHER AND BECOME SURFACE BASED AS THE BOUNDARY LAYER
WARMS. IN WAKE OF THIS ACTIVITY...THE WARM SECTOR IS
DESTABILIZING...AND CONVECTIVE TEMPERATURES WILL LIKELY BE REACHED
AS TEMPERATURES WARM THROUGH THE 80S. ADDITIONAL STORMS WILL LIKELY
DEVELOP DURING THE EARLY-MID AFTERNOON PROMOTED BY THE DESTABILIZING
BOUNDARY LAYER AND MESOSCALE ASCENT ATTENDING THE MCV. A BELT OF
40-50 KT MID-LEVEL WINDS ROTATING THROUGH BASE OF THE MCV ALONG WITH
30-40 KT SLY LLJ WILL CONTRIBUTE TO SUFFICIENT SHEAR FOR ORGANIZED
STORMS INCLUDING A FEW SUPERCELLS.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...ILX...LSX...DVN...ARX...MPX...DMX...EAX...

LAT...LON   41809416 43279465 44639493 44989314 43069135 41529072
            39579082 40469358 41809416

000
ACUS11 KWNS 191630
SWOMCD
SPC MCD 191630
IAZ000-ILZ000-MNZ000-MOZ000-191800-

MESOSCALE DISCUSSION 0695
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT SUN MAY 19 2013

AREAS AFFECTED...NERN MO...ERN IA...AND SERN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 191630Z - 191800Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
OVER THE MID-UPPER MS VALLEY REGION DURING EARLY-MID AFTERNOON.
POTENTIAL WILL EXIST FOR ORGANIZED MULTICELLS AS WELL AS A FEW
SUPERCELLS. MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WIND...BUT
A COUPLE TORNADOES MAY ALSO BE POSSIBLE. A WW MIGHT BE NEEDED BEFORE
18Z.

DISCUSSION...LATE THIS MORNING WELL DEFINED MCV WAS LOCATED OVER
SWRN IA LIFTING NEWD. ELEVATED STORMS CURRENTLY DEVELOPING OVER ERN
IA INTO WRN IL MAY POSE A THREAT FOR HAIL. THESE STORMS MAY
INTENSIFY FURTHER AND BECOME SURFACE BASED AS THE BOUNDARY LAYER
WARMS. IN WAKE OF THIS ACTIVITY...THE WARM SECTOR IS
DESTABILIZING...AND CONVECTIVE TEMPERATURES WILL LIKELY BE REACHED
AS TEMPERATURES WARM THROUGH THE 80S. ADDITIONAL STORMS WILL LIKELY
DEVELOP DURING THE EARLY-MID AFTERNOON PROMOTED BY THE DESTABILIZING
BOUNDARY LAYER AND MESOSCALE ASCENT ATTENDING THE MCV. A BELT OF
40-50 KT MID-LEVEL WINDS ROTATING THROUGH BASE OF THE MCV ALONG WITH
30-40 KT SLY LLJ WILL CONTRIBUTE TO SUFFICIENT SHEAR FOR ORGANIZED
STORMS INCLUDING A FEW SUPERCELLS.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...ILX...LSX...DVN...ARX...MPX...DMX...EAX...

LAT...LON   41809416 43279465 44639493 44989314 43069135 41529072
            39579082 40469358 41809416

000
ACUS11 KWNS 191630
SWOMCD
SPC MCD 191630
IAZ000-ILZ000-MNZ000-MOZ000-191800-

MESOSCALE DISCUSSION 0695
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT SUN MAY 19 2013

AREAS AFFECTED...NERN MO...ERN IA...AND SERN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 191630Z - 191800Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
OVER THE MID-UPPER MS VALLEY REGION DURING EARLY-MID AFTERNOON.
POTENTIAL WILL EXIST FOR ORGANIZED MULTICELLS AS WELL AS A FEW
SUPERCELLS. MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WIND...BUT
A COUPLE TORNADOES MAY ALSO BE POSSIBLE. A WW MIGHT BE NEEDED BEFORE
18Z.

DISCUSSION...LATE THIS MORNING WELL DEFINED MCV WAS LOCATED OVER
SWRN IA LIFTING NEWD. ELEVATED STORMS CURRENTLY DEVELOPING OVER ERN
IA INTO WRN IL MAY POSE A THREAT FOR HAIL. THESE STORMS MAY
INTENSIFY FURTHER AND BECOME SURFACE BASED AS THE BOUNDARY LAYER
WARMS. IN WAKE OF THIS ACTIVITY...THE WARM SECTOR IS
DESTABILIZING...AND CONVECTIVE TEMPERATURES WILL LIKELY BE REACHED
AS TEMPERATURES WARM THROUGH THE 80S. ADDITIONAL STORMS WILL LIKELY
DEVELOP DURING THE EARLY-MID AFTERNOON PROMOTED BY THE DESTABILIZING
BOUNDARY LAYER AND MESOSCALE ASCENT ATTENDING THE MCV. A BELT OF
40-50 KT MID-LEVEL WINDS ROTATING THROUGH BASE OF THE MCV ALONG WITH
30-40 KT SLY LLJ WILL CONTRIBUTE TO SUFFICIENT SHEAR FOR ORGANIZED
STORMS INCLUDING A FEW SUPERCELLS.

..DIAL/KERR.. 05/19/2013

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

ATTN...WFO...ILX...LSX...DVN...ARX...MPX...DMX...EAX...

LAT...LON   41809416 43279465 44639493 44989314 43069135 41529072
            39579082 40469358 41809416

000
ACUS01 KWNS 191617
SWODY1
SPC AC 191615

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1115 AM CDT SUN MAY 19 2013

VALID 191630Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING
ACROSS PARTS OF EASTERN KANSAS AND OKLAHOMA INTO WESTERN MISSOURI...

...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO
TONIGHT...SURROUNDING THE MODERATE RISK AREA ACROSS MUCH OF THE
EASTERN PLAINS INTO THE MID AND UPPER MISSISSIPPI VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS PARTS OF
CENTRAL AND SOUTHERN GEORGIA INTO NORTHERN FLORIDA...

...SYNOPSIS...
A DEEP LAYER CYCLONE APPEARS LIKELY TO CONTINUE TO EVOLVE THROUGH
THIS FORECAST PERIOD OVER THE MID MISSOURI VALLEY REGION.  IN
ASSOCIATION WITH THIS FEATURE...MID/UPPER FLOW HAS ALREADY
STRENGTHENED ACROSS THE TEXAS/OKLAHOMA PANHANDLE REGION THROUGH THE
CENTRAL PLAINS AND UPPER MISSISSIPPI VALLEY...IN A BELT CURVING
CYCLONICALLY OUT OF THE INTERMOUNTAIN REGION.  WITHIN THIS
REGIME...A SERIES OF SHORT WAVE IMPULSES/SPEED MAXIMA HAVE AND WILL
CONTINUE TO EMERGE FROM THE INTERMOUNTAIN WEST...WHILE ADDITIONAL
PERTURBATIONS CONTINUE TO DIG INTO THE GREAT BASIN.

EAST OF THE ROCKIES...MID-LEVEL LAPSE RATES REMAIN VERY STEEP OVER A
BROAD AREA...FROM THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY
SOUTHWARD TO GULF COASTAL AREAS.  ATOP A RELATIVELY MOIST BOUNDARY
LAYER...THIS WILL CONTRIBUTE TO SUBSTANTIAL CONVECTIVE INSTABILITY
AND SIZABLE CAPE ACROSS A BROAD AREA OF THE PLAINS AND MISSISSIPPI
VALLEY REGION.  THIS IS EXPECTED TO BE ACCOMPANIED BY CONSIDERABLE
THUNDERSTORM ACTIVITY...INCLUDING ANOTHER OUTBREAK OF SEVERE
WEATHER...PARTICULARLY ACROSS PARTS OF EASTERN KANSAS AND OKLAHOMA
INTO PARTS OF MISSOURI.

ADDITIONALLY...ON THE WESTERN PERIPHERY OF A WEAK CYCLONIC BELT OF
FLOW DEVELOPING EASTWARD ACROSS THE SOUTH ATLANTIC COAST
REGION...LIFT AND STEEPENING MID-LEVEL LAPSE RATES ASSOCIATED WITH
LOWER/MID TROPOSPHERIC WARM ADVECTION WILL MAINTAIN A RISK FOR
THUNDERSTORM ACTIVITY FROM PARTS OF THE TENNESSEE VALLEY INTO
GEORGIA AND NORTHERN FLORIDA.  MARGINALLY SEVERE WIND AND HAIL DO
NOT APPEAR OUT OF THE QUESTION IN STRONGER STORMS...PARTICULARLY
WITH ADDITIONAL HEATING AHEAD OF AN ORGANIZING STORM CLUSTER NOW
ADVANCING WEST THROUGH SOUTH OF ATLANTA GA.

...PLAINS/MISSISSIPPI VALLEY...
ONE SHORT WAVE IMPULSE IS CURRENTLY IN THE PROCESS OF TURNING
NORTHEAST OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY.
THIS FEATURE IS AIDING INCREASING STORM DEVELOPMENT ACROSS PARTS OF
NORTHEAST MISSOURI INTO WEST CENTRAL ILLINOIS.  SOME SEVERE
HAIL/WIND POTENTIAL MAY EXIST WITH THIS ACTIVITY... BUT A MORE
SUBSTANTIVE SEVERE WEATHER RISK MAY AWAIT FURTHER BOUNDARY LAYER
DESTABILIZATION AND WEAKENING INHIBITION ACROSS IOWA NORTHWARD INTO
PARTS OF MINNESOTA AND WISCONSIN LATER TODAY.

THE PRIMARY SEVERE WEATHER POTENTIAL IS EXPECTED TO DEVELOP IN THE
WAKE OF THIS INITIAL IMPULSE...AS ANOTHER CONTINUES TO PIVOT EAST OF
THE CENTRAL HIGH PLAINS THIS AFTERNOON.  THIS SEEMS MOST LIKELY TO
BECOME FOCUSED ALONG/SOUTH AND EAST OF A REMNANT CONVECTIVELY
GENERATED BOUNDARY THAT CURRENTLY CURVES FROM THE MISSOURI OZARKS
INTO NORTHERN OKLAHOMA.  A NORTHWARD RETREAT OF THIS BOUNDARY INTO
SOUTHERN KANSAS IS STILL EXPECTED...AND LATEST HIGH RESOLUTION RAPID
REFRESH APPEARS REASONABLE SUGGESTING INITIATION OF STORMS ALONG THE
INTERSECTION OF THIS BOUNDARY AND AN EASTWARD ADVANCING
DRYLINE...ACROSS NORTH CENTRAL OKLAHOMA OR SOUTH CENTRAL KANSAS...BY
19-20Z.

AIDED BY FORCING IN THE EXIT REGION OF A MID-LEVEL SPEED MAXIMUM
NOSING NORTHEASTWARD ACROSS THE SOUTH CENTRAL PLAINS...UPSCALE
CONVECTIVE GROWTH INTO A SUBSTANTIAL MESOSCALE CONVECTIVE SYSTEM IS
EXPECTED LATE THIS AFTERNOON AND EVENING.  IN THE PRESENCE OF STRONG
DEEP LAYER SHEAR...40-50 KT SOUTHERLY 850 MB FLOW NEAR AND SOUTH OF
THE CONVECTIVE BOUNDARY WILL CONTRIBUTE TO SIZABLE CLOCKWISE CURVED
LOW-LEVEL HODOGRAPHS SUPPORTIVE OF THE RISK FOR TORNADOES.  HIGHEST
PROBABILITIES FOR TORNADOES...SOME POSSIBLY STRONG...MAY BE
SUPERCELLS ON THE SOUTHERN FLANK OF THE EVOLVING CONVECTIVE
SYSTEM...ACROSS SOUTHEAST KANSAS INTO PARTS OF WEST
CENTRAL/SOUTHEAST MISSOURI...AS WELL AS WITH STORMS INITIATING AND
ADVANCING NORTHEASTWARD OFF THE DRYLINE...ACROSS NORTHEASTERN
OKLAHOMA.  FURTHER STRENGTHENING OF THE 850 MB JET ACROSS EASTERN
OKLAHOMA INTO SOUTHWEST MISSOURI WILL MAINTAIN TORNADIC POTENTIAL
WELL INTO THE EVENING HOURS...WITH ONE OR TWO LONG-LIVED TORNADIC
SUPERCELLS POSSIBLE.

..KERR/ROGERS.. 05/19/2013

000
ACUS01 KWNS 191617
SWODY1
SPC AC 191615

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1115 AM CDT SUN MAY 19 2013

VALID 191630Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING
ACROSS PARTS OF EASTERN KANSAS AND OKLAHOMA INTO WESTERN MISSOURI...

...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO
TONIGHT...SURROUNDING THE MODERATE RISK AREA ACROSS MUCH OF THE
EASTERN PLAINS INTO THE MID AND UPPER MISSISSIPPI VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS PARTS OF
CENTRAL AND SOUTHERN GEORGIA INTO NORTHERN FLORIDA...

...SYNOPSIS...
A DEEP LAYER CYCLONE APPEARS LIKELY TO CONTINUE TO EVOLVE THROUGH
THIS FORECAST PERIOD OVER THE MID MISSOURI VALLEY REGION.  IN
ASSOCIATION WITH THIS FEATURE...MID/UPPER FLOW HAS ALREADY
STRENGTHENED ACROSS THE TEXAS/OKLAHOMA PANHANDLE REGION THROUGH THE
CENTRAL PLAINS AND UPPER MISSISSIPPI VALLEY...IN A BELT CURVING
CYCLONICALLY OUT OF THE INTERMOUNTAIN REGION.  WITHIN THIS
REGIME...A SERIES OF SHORT WAVE IMPULSES/SPEED MAXIMA HAVE AND WILL
CONTINUE TO EMERGE FROM THE INTERMOUNTAIN WEST...WHILE ADDITIONAL
PERTURBATIONS CONTINUE TO DIG INTO THE GREAT BASIN.

EAST OF THE ROCKIES...MID-LEVEL LAPSE RATES REMAIN VERY STEEP OVER A
BROAD AREA...FROM THE CENTRAL PLAINS AND MIDDLE MISSISSIPPI VALLEY
SOUTHWARD TO GULF COASTAL AREAS.  ATOP A RELATIVELY MOIST BOUNDARY
LAYER...THIS WILL CONTRIBUTE TO SUBSTANTIAL CONVECTIVE INSTABILITY
AND SIZABLE CAPE ACROSS A BROAD AREA OF THE PLAINS AND MISSISSIPPI
VALLEY REGION.  THIS IS EXPECTED TO BE ACCOMPANIED BY CONSIDERABLE
THUNDERSTORM ACTIVITY...INCLUDING ANOTHER OUTBREAK OF SEVERE
WEATHER...PARTICULARLY ACROSS PARTS OF EASTERN KANSAS AND OKLAHOMA
INTO PARTS OF MISSOURI.

ADDITIONALLY...ON THE WESTERN PERIPHERY OF A WEAK CYCLONIC BELT OF
FLOW DEVELOPING EASTWARD ACROSS THE SOUTH ATLANTIC COAST
REGION...LIFT AND STEEPENING MID-LEVEL LAPSE RATES ASSOCIATED WITH
LOWER/MID TROPOSPHERIC WARM ADVECTION WILL MAINTAIN A RISK FOR
THUNDERSTORM ACTIVITY FROM PARTS OF THE TENNESSEE VALLEY INTO
GEORGIA AND NORTHERN FLORIDA.  MARGINALLY SEVERE WIND AND HAIL DO
NOT APPEAR OUT OF THE QUESTION IN STRONGER STORMS...PARTICULARLY
WITH ADDITIONAL HEATING AHEAD OF AN ORGANIZING STORM CLUSTER NOW
ADVANCING WEST THROUGH SOUTH OF ATLANTA GA.

...PLAINS/MISSISSIPPI VALLEY...
ONE SHORT WAVE IMPULSE IS CURRENTLY IN THE PROCESS OF TURNING
NORTHEAST OF THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY.
THIS FEATURE IS AIDING INCREASING STORM DEVELOPMENT ACROSS PARTS OF
NORTHEAST MISSOURI INTO WEST CENTRAL ILLINOIS.  SOME SEVERE
HAIL/WIND POTENTIAL MAY EXIST WITH THIS ACTIVITY... BUT A MORE
SUBSTANTIVE SEVERE WEATHER RISK MAY AWAIT FURTHER BOUNDARY LAYER
DESTABILIZATION AND WEAKENING INHIBITION ACROSS IOWA NORTHWARD INTO
PARTS OF MINNESOTA AND WISCONSIN LATER TODAY.

THE PRIMARY SEVERE WEATHER POTENTIAL IS EXPECTED TO DEVELOP IN THE
WAKE OF THIS INITIAL IMPULSE...AS ANOTHER CONTINUES TO PIVOT EAST OF
THE CENTRAL HIGH PLAINS THIS AFTERNOON.  THIS SEEMS MOST LIKELY TO
BECOME FOCUSED ALONG/SOUTH AND EAST OF A REMNANT CONVECTIVELY
GENERATED BOUNDARY THAT CURRENTLY CURVES FROM THE MISSOURI OZARKS
INTO NORTHERN OKLAHOMA.  A NORTHWARD RETREAT OF THIS BOUNDARY INTO
SOUTHERN KANSAS IS STILL EXPECTED...AND LATEST HIGH RESOLUTION RAPID
REFRESH APPEARS REASONABLE SUGGESTING INITIATION OF STORMS ALONG THE
INTERSECTION OF THIS BOUNDARY AND AN EASTWARD ADVANCING
DRYLINE...ACROSS NORTH CENTRAL OKLAHOMA OR SOUTH CENTRAL KANSAS...BY
19-20Z.

AIDED BY FORCING IN THE EXIT REGION OF A MID-LEVEL SPEED MAXIMUM
NOSING NORTHEASTWARD ACROSS THE SOUTH CENTRAL PLAINS...UPSCALE
CONVECTIVE GROWTH INTO A SUBSTANTIAL MESOSCALE CONVECTIVE SYSTEM IS
EXPECTED LATE THIS AFTERNOON AND EVENING.  IN THE PRESENCE OF STRONG
DEEP LAYER SHEAR...40-50 KT SOUTHERLY 850 MB FLOW NEAR AND SOUTH OF
THE CONVECTIVE BOUNDARY WILL CONTRIBUTE TO SIZABLE CLOCKWISE CURVED
LOW-LEVEL HODOGRAPHS SUPPORTIVE OF THE RISK FOR TORNADOES.  HIGHEST
PROBABILITIES FOR TORNADOES...SOME POSSIBLY STRONG...MAY BE
SUPERCELLS ON THE SOUTHERN FLANK OF THE EVOLVING CONVECTIVE
SYSTEM...ACROSS SOUTHEAST KANSAS INTO PARTS OF WEST
CENTRAL/SOUTHEAST MISSOURI...AS WELL AS WITH STORMS INITIATING AND
ADVANCING NORTHEASTWARD OFF THE DRYLINE...ACROSS NORTHEASTERN
OKLAHOMA.  FURTHER STRENGTHENING OF THE 850 MB JET ACROSS EASTERN
OKLAHOMA INTO SOUTHWEST MISSOURI WILL MAINTAIN TORNADIC POTENTIAL
WELL INTO THE EVENING HOURS...WITH ONE OR TWO LONG-LIVED TORNADIC
SUPERCELLS POSSIBLE.

..KERR/ROGERS.. 05/19/2013

000
ACUS01 KWNS 191236
SWODY1
SPC AC 191233

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0733 AM CDT SUN MAY 19 2013

VALID 191300Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF EASTERN
KS...WESTERN MO...AND CENTRAL/EASTERN OK...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CENTRAL
PLAINS AND UPPER MS VALLEY...

...KS/MO/OK...
MULTIPLE CLUSTERS OF THUNDERSTORMS HAVE PERSISTED OVERNIGHT ACROSS
THE CENTRAL PLAINS.  NEVERTHELESS...CURRENT SURFACE ANALYSIS SHOWS A
VERY MOIST AND UNSTABLE AIR MASS IN PLACE OVER MUCH OF TX/OK.  THIS
AIR MASS IS POISED TO RETURN RAPIDLY NORTHWARD INTO EASTERN KS AND
WESTERN MO BY MID AFTERNOON...SETTING THE STAGE FOR ANOTHER ACTIVE
SEVERE WEATHER DAY OVER THE REGION.

A RELATIVELY STRONG CAPPING INVERSION IS IN PLACE OVER THE CENTRAL
PLAINS THIS MORNING.  THIS CAP WILL INHIBIT SURFACE-BASED STORMS
THROUGH MUCH OF THE DAY.  HOWEVER...STRONG HEATING/MIXING ALONG THE
DRYLINE OVER CENTRAL OK ALONG WITH FORCING IN VICINITY OF THE COLD
FRONT OVER EASTERN KS ARE EXPECTED TO LEAD TO SCATTERED THUNDERSTORM
DEVELOPMENT BETWEEN 20-23Z.  INITIAL STORMS WILL LIKELY BE DISCRETE
SUPERCELLS.  THE OVERALL ENVIRONMENT APPEARS QUITE FAVORABLE FOR
TORNADOES...BUT A FEW SUBTLE STORM-SCALE DETAILS WILL INFLUENCE THE
OUTCOME.  ONE PROBLEM MAY BE THE DEGREE OF HEATING REQUIRED TO BREAK
THE CAP OVER OK AND THE RESULTING LCL HEIGHTS.  NEVERTHELESS...VERY
HIGH CAPE VALUES /MLCAPE OVER 4000 J/KG/ MAY OFFSET THE NEGATIVE
INFLUENCES SO HAVE INCREASED TORNADO PROBABILITIES OVER PORTIONS OF
THE MODERATE RISK AREA.  IF STORMS CAN REMAIN DISCRETE...RAPIDLY
INCREASING LOW LEVEL SHEAR AFTER 00Z /0-3KM HELICITY VALUES RISING
TO 300-500 M2/S2/ WILL POSE A RISK FOR STRONG TORNADOES AS FAR EAST
AS SOUTHWEST MO.

OTHERWISE...THE DEGREE OF INSTABILITY...SUPERCELL STRUCTURES...AND
MID LEVEL LAPSE RATES OF 8.0+ C/KM WILL PROMOTE A RISK OF VERY LARGE
HAIL.  STORMS MAY ORGANIZE INTO A SQUALL LINE AFTER DARK AND SPREAD
EASTWARD INTO WESTERN MO WITH AN ENHANCED RISK OF WIDESPREAD
DAMAGING WINDS.

...UPPER MS VALLEY INTO ND...
A SURFACE LOW IS FORECAST TO REMAIN OVER SD THROUGH THIS AFTERNOON.
MULTIPLE AREAS OF OVERNIGHT CONVECTION HAVE COMPLICATED THE SURFACE
PATTERN OVER THE REGION AND MAKE DESTABILIZATION UNCERTAIN.
HOWEVER...IT APPEARS THAT PORTIONS OF IA/MN WILL BE MOST LIKELY TO
SEE SOME DAYTIME HEATING AND RETURN OF RICH MOISTURE BEFORE MAIN
LARGE SCALE ASCENT ARRIVES.  THIS MAY RESULT IN SCATTERED
STRONG/SEVERE THUNDERSTORM DEVELOPMENT.  HAIL AND DAMAGING WINDS ARE
THE MAIN THREATS.  BACKED LOW LEVEL WINDS EAST OF THE SURFACE LOW
MAY ALSO ENHANCE SHEAR/CONVERGENCE AND RESULT IN A STRONG/SEVERE
THUNDERSTORM OR TWO WITH A TORNADO POSSIBLE.

...TX...
A FEW OF THE OVERNIGHT MESOSCALE MODELS HAVE SHOWN A TREND OF
DEVELOPING ISOLATED STORMS SOUTHWARD ALONG THE DRYLINE AS FAR SOUTH
AS CENTRAL TX.  CONFIDENCE IN THIS DEVELOPMENT IS RATHER LOW.
HOWEVER...ANY STORMS THAT FORM ALONG THE DRYLINE WILL HAVE THE
POTENTIAL FOR VERY LARGE HAIL AND DAMAGING WINDS.

...SOUTHEAST STATES...
MODERATE TO STRONG INSTABILITY IS FORECAST TO DEVELOP THIS AFTERNOON
ACROSS PARTS OF GA/TN/AL.  WEAK BOUNDARIES FROM OVERNIGHT STORMS MAY
PROVIDE FOCUS FOR ADDITIONAL DEVELOPMENT TODAY...WITH DAMAGING WINDS
AND HAIL POSSIBLE FROM THE STRONGEST STORMS.

..HART/LEITMAN.. 05/19/2013

000
ACUS01 KWNS 191236
SWODY1
SPC AC 191233

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0733 AM CDT SUN MAY 19 2013

VALID 191300Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS OVER PORTIONS OF EASTERN
KS...WESTERN MO...AND CENTRAL/EASTERN OK...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE CENTRAL
PLAINS AND UPPER MS VALLEY...

...KS/MO/OK...
MULTIPLE CLUSTERS OF THUNDERSTORMS HAVE PERSISTED OVERNIGHT ACROSS
THE CENTRAL PLAINS.  NEVERTHELESS...CURRENT SURFACE ANALYSIS SHOWS A
VERY MOIST AND UNSTABLE AIR MASS IN PLACE OVER MUCH OF TX/OK.  THIS
AIR MASS IS POISED TO RETURN RAPIDLY NORTHWARD INTO EASTERN KS AND
WESTERN MO BY MID AFTERNOON...SETTING THE STAGE FOR ANOTHER ACTIVE
SEVERE WEATHER DAY OVER THE REGION.

A RELATIVELY STRONG CAPPING INVERSION IS IN PLACE OVER THE CENTRAL
PLAINS THIS MORNING.  THIS CAP WILL INHIBIT SURFACE-BASED STORMS
THROUGH MUCH OF THE DAY.  HOWEVER...STRONG HEATING/MIXING ALONG THE
DRYLINE OVER CENTRAL OK ALONG WITH FORCING IN VICINITY OF THE COLD
FRONT OVER EASTERN KS ARE EXPECTED TO LEAD TO SCATTERED THUNDERSTORM
DEVELOPMENT BETWEEN 20-23Z.  INITIAL STORMS WILL LIKELY BE DISCRETE
SUPERCELLS.  THE OVERALL ENVIRONMENT APPEARS QUITE FAVORABLE FOR
TORNADOES...BUT A FEW SUBTLE STORM-SCALE DETAILS WILL INFLUENCE THE
OUTCOME.  ONE PROBLEM MAY BE THE DEGREE OF HEATING REQUIRED TO BREAK
THE CAP OVER OK AND THE RESULTING LCL HEIGHTS.  NEVERTHELESS...VERY
HIGH CAPE VALUES /MLCAPE OVER 4000 J/KG/ MAY OFFSET THE NEGATIVE
INFLUENCES SO HAVE INCREASED TORNADO PROBABILITIES OVER PORTIONS OF
THE MODERATE RISK AREA.  IF STORMS CAN REMAIN DISCRETE...RAPIDLY
INCREASING LOW LEVEL SHEAR AFTER 00Z /0-3KM HELICITY VALUES RISING
TO 300-500 M2/S2/ WILL POSE A RISK FOR STRONG TORNADOES AS FAR EAST
AS SOUTHWEST MO.

OTHERWISE...THE DEGREE OF INSTABILITY...SUPERCELL STRUCTURES...AND
MID LEVEL LAPSE RATES OF 8.0+ C/KM WILL PROMOTE A RISK OF VERY LARGE
HAIL.  STORMS MAY ORGANIZE INTO A SQUALL LINE AFTER DARK AND SPREAD
EASTWARD INTO WESTERN MO WITH AN ENHANCED RISK OF WIDESPREAD
DAMAGING WINDS.

...UPPER MS VALLEY INTO ND...
A SURFACE LOW IS FORECAST TO REMAIN OVER SD THROUGH THIS AFTERNOON.
MULTIPLE AREAS OF OVERNIGHT CONVECTION HAVE COMPLICATED THE SURFACE
PATTERN OVER THE REGION AND MAKE DESTABILIZATION UNCERTAIN.
HOWEVER...IT APPEARS THAT PORTIONS OF IA/MN WILL BE MOST LIKELY TO
SEE SOME DAYTIME HEATING AND RETURN OF RICH MOISTURE BEFORE MAIN
LARGE SCALE ASCENT ARRIVES.  THIS MAY RESULT IN SCATTERED
STRONG/SEVERE THUNDERSTORM DEVELOPMENT.  HAIL AND DAMAGING WINDS ARE
THE MAIN THREATS.  BACKED LOW LEVEL WINDS EAST OF THE SURFACE LOW
MAY ALSO ENHANCE SHEAR/CONVERGENCE AND RESULT IN A STRONG/SEVERE
THUNDERSTORM OR TWO WITH A TORNADO POSSIBLE.

...TX...
A FEW OF THE OVERNIGHT MESOSCALE MODELS HAVE SHOWN A TREND OF
DEVELOPING ISOLATED STORMS SOUTHWARD ALONG THE DRYLINE AS FAR SOUTH
AS CENTRAL TX.  CONFIDENCE IN THIS DEVELOPMENT IS RATHER LOW.
HOWEVER...ANY STORMS THAT FORM ALONG THE DRYLINE WILL HAVE THE
POTENTIAL FOR VERY LARGE HAIL AND DAMAGING WINDS.

...SOUTHEAST STATES...
MODERATE TO STRONG INSTABILITY IS FORECAST TO DEVELOP THIS AFTERNOON
ACROSS PARTS OF GA/TN/AL.  WEAK BOUNDARIES FROM OVERNIGHT STORMS MAY
PROVIDE FOCUS FOR ADDITIONAL DEVELOPMENT TODAY...WITH DAMAGING WINDS
AND HAIL POSSIBLE FROM THE STRONGEST STORMS.

..HART/LEITMAN.. 05/19/2013

000
ACUS11 KWNS 191026
SWOMCD
SPC MCD 191025
MOZ000-OKZ000-KSZ000-191230-

MESOSCALE DISCUSSION 0694
NWS STORM PREDICTION CENTER NORMAN OK
0525 AM CDT SUN MAY 19 2013

AREAS AFFECTED...PARTS OF NERN OK...SERN KS AND FAR WEST
CENTRAL-SWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 191025Z - 191230Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED HAIL AROUND 1 INCH IN DIAMETER AND/OR A LOCALLY
STRONG WIND GUST WILL BE POSSIBLE FROM PART OF NERN OK INTO SERN KS
THROUGH 12-13Z. LIMITED SPATIOTEMPORAL THREAT AREA WITH THE NERN
OK/SERN KS TSTM CLUSTER EXPECTED TO WEAKEN IN INTENSITY/COVERAGE
ALONG THE SERN KS/SWRN MO BORDER 1-2 HRS AFTER SUNRISE PRECLUDES THE
ISSUANCE OF A SEVERE WEATHER WATCH.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY INDICATED AN INCREASE
IN TSTM INTENSITY AND THE EVOLUTION OF A BROKEN LINE OVER NERN OK
/OSAGE COUNTY/ INTO SERN KS /CHAUTAUQUA AND SWRN WILSON COUNTIES/
BETWEEN 09-10Z.  THIS UPTICK IN TSTM STRENGTH/ORGANIZATION IS
LOCATED ALONG THE SERN PERIPHERY OF A SRN-ERN KS/NRN OK MCS...AND
PER OBJECTIVE ANALYSES IS SITUATED WITHIN A ZONE OF STRONGER LOW
LEVEL WAA AND RESIDUAL MODERATE-STRONG INSTABILITY EXTENDING EWD
FROM SERN KS/NERN OK.  THESE FAVORABLE THERMODYNAMICS COMBINED WITH
STEEP MIDLEVEL LAPSE RATES /AROUND 8 C PER KM/ COULD MAINTAIN THE
POTENTIAL FOR AN ISOLATED SVR HAIL EVENT AND/OR A STRONGER WIND GUST
FOR AN ADDITIONAL 2-3 HOURS.

MEANWHILE...IR IMAGERY SHOWED WARMING CLOUD TOP TRENDS WITH THE
PARENT MCS...AND THE 05-07Z HRRR RUNS EACH INDICATED THE DEMISE OF
THIS TSTM SYSTEM BY 12-13Z AS THE ERN PERIPHERY OF ONGOING STORMS
REACHES THE SERN KS/SWRN MO BORDER AROUND THAT TIME.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TSA...ICT...

LAT...LON   37599591 37939545 38139454 37819436 37169446 36899481
            36679529 36549574 36569597 36799607 37599591

000
ACUS11 KWNS 191026
SWOMCD
SPC MCD 191025
MOZ000-OKZ000-KSZ000-191230-

MESOSCALE DISCUSSION 0694
NWS STORM PREDICTION CENTER NORMAN OK
0525 AM CDT SUN MAY 19 2013

AREAS AFFECTED...PARTS OF NERN OK...SERN KS AND FAR WEST
CENTRAL-SWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 191025Z - 191230Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED HAIL AROUND 1 INCH IN DIAMETER AND/OR A LOCALLY
STRONG WIND GUST WILL BE POSSIBLE FROM PART OF NERN OK INTO SERN KS
THROUGH 12-13Z. LIMITED SPATIOTEMPORAL THREAT AREA WITH THE NERN
OK/SERN KS TSTM CLUSTER EXPECTED TO WEAKEN IN INTENSITY/COVERAGE
ALONG THE SERN KS/SWRN MO BORDER 1-2 HRS AFTER SUNRISE PRECLUDES THE
ISSUANCE OF A SEVERE WEATHER WATCH.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY INDICATED AN INCREASE
IN TSTM INTENSITY AND THE EVOLUTION OF A BROKEN LINE OVER NERN OK
/OSAGE COUNTY/ INTO SERN KS /CHAUTAUQUA AND SWRN WILSON COUNTIES/
BETWEEN 09-10Z.  THIS UPTICK IN TSTM STRENGTH/ORGANIZATION IS
LOCATED ALONG THE SERN PERIPHERY OF A SRN-ERN KS/NRN OK MCS...AND
PER OBJECTIVE ANALYSES IS SITUATED WITHIN A ZONE OF STRONGER LOW
LEVEL WAA AND RESIDUAL MODERATE-STRONG INSTABILITY EXTENDING EWD
FROM SERN KS/NERN OK.  THESE FAVORABLE THERMODYNAMICS COMBINED WITH
STEEP MIDLEVEL LAPSE RATES /AROUND 8 C PER KM/ COULD MAINTAIN THE
POTENTIAL FOR AN ISOLATED SVR HAIL EVENT AND/OR A STRONGER WIND GUST
FOR AN ADDITIONAL 2-3 HOURS.

MEANWHILE...IR IMAGERY SHOWED WARMING CLOUD TOP TRENDS WITH THE
PARENT MCS...AND THE 05-07Z HRRR RUNS EACH INDICATED THE DEMISE OF
THIS TSTM SYSTEM BY 12-13Z AS THE ERN PERIPHERY OF ONGOING STORMS
REACHES THE SERN KS/SWRN MO BORDER AROUND THAT TIME.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TSA...ICT...

LAT...LON   37599591 37939545 38139454 37819436 37169446 36899481
            36679529 36549574 36569597 36799607 37599591

000
ACUS11 KWNS 191026
SWOMCD
SPC MCD 191025
MOZ000-OKZ000-KSZ000-191230-

MESOSCALE DISCUSSION 0694
NWS STORM PREDICTION CENTER NORMAN OK
0525 AM CDT SUN MAY 19 2013

AREAS AFFECTED...PARTS OF NERN OK...SERN KS AND FAR WEST
CENTRAL-SWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 191025Z - 191230Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED HAIL AROUND 1 INCH IN DIAMETER AND/OR A LOCALLY
STRONG WIND GUST WILL BE POSSIBLE FROM PART OF NERN OK INTO SERN KS
THROUGH 12-13Z. LIMITED SPATIOTEMPORAL THREAT AREA WITH THE NERN
OK/SERN KS TSTM CLUSTER EXPECTED TO WEAKEN IN INTENSITY/COVERAGE
ALONG THE SERN KS/SWRN MO BORDER 1-2 HRS AFTER SUNRISE PRECLUDES THE
ISSUANCE OF A SEVERE WEATHER WATCH.

DISCUSSION...TRENDS IN REGIONAL RADAR IMAGERY INDICATED AN INCREASE
IN TSTM INTENSITY AND THE EVOLUTION OF A BROKEN LINE OVER NERN OK
/OSAGE COUNTY/ INTO SERN KS /CHAUTAUQUA AND SWRN WILSON COUNTIES/
BETWEEN 09-10Z.  THIS UPTICK IN TSTM STRENGTH/ORGANIZATION IS
LOCATED ALONG THE SERN PERIPHERY OF A SRN-ERN KS/NRN OK MCS...AND
PER OBJECTIVE ANALYSES IS SITUATED WITHIN A ZONE OF STRONGER LOW
LEVEL WAA AND RESIDUAL MODERATE-STRONG INSTABILITY EXTENDING EWD
FROM SERN KS/NERN OK.  THESE FAVORABLE THERMODYNAMICS COMBINED WITH
STEEP MIDLEVEL LAPSE RATES /AROUND 8 C PER KM/ COULD MAINTAIN THE
POTENTIAL FOR AN ISOLATED SVR HAIL EVENT AND/OR A STRONGER WIND GUST
FOR AN ADDITIONAL 2-3 HOURS.

MEANWHILE...IR IMAGERY SHOWED WARMING CLOUD TOP TRENDS WITH THE
PARENT MCS...AND THE 05-07Z HRRR RUNS EACH INDICATED THE DEMISE OF
THIS TSTM SYSTEM BY 12-13Z AS THE ERN PERIPHERY OF ONGOING STORMS
REACHES THE SERN KS/SWRN MO BORDER AROUND THAT TIME.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...SGF...EAX...TSA...ICT...

LAT...LON   37599591 37939545 38139454 37819436 37169446 36899481
            36679529 36549574 36569597 36799607 37599591

000
ACUS11 KWNS 190732
SWOMCD
SPC MCD 190732
MNZ000-NDZ000-SDZ000-190900-

MESOSCALE DISCUSSION 0693
NWS STORM PREDICTION CENTER NORMAN OK
0232 AM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN ND AND ADJACENT NWRN MN COUNTIES

CONCERNING...SEVERE THUNDERSTORM WATCH 178...

VALID 190732Z - 190900Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 178
CONTINUES.

SUMMARY...LOCALLY STRONG WIND GUSTS WILL BE POSSIBLE THROUGH 09Z
ACROSS THE SRN EXTENT OF WW 178 AS AN ARCING LINE OF STORMS IN ERN
SD MOVES INTO SERN ND AND THE ADJACENT MN COUNTIES BETWEEN 08-09Z.
THE SEVERE WEATHER THREAT IS LIKELY DIMINISHED IN THE NRN PART OF WW
178.

DISCUSSION...TRENDS IN RADAR IMAGERY OVER ERN ND INDICATED THE
STORMS THAT MOVED THROUGH THE KJMS AREA AROUND 0430Z HAVE SINCE
WEAKENED AS THEY MOVED INTO THE NWRN PART OF WW 178. A MORE STABLE
ENVIRONMENT ACROSS THE NRN PART OF THIS WATCH SUGGESTS THE SEVERE
WEATHER THREAT IS ALL BUT OVER N OF A BARNES/CASS COUNTIES ND TO
NORMAN COUNTY MN LINE.

MEANWHILE...RADAR MOSAIC INDICATED AN ARCING LINE OF STORMS
EXTENDING GENERALLY NW-SE FROM ERN SD INTO FAR SWRN MN...WITH THE
NERN SD PORTION OF THIS LINE MOVING NEWD AROUND 40 KT.  THE KHON
OBSERVATION REPORTED A WIND GUST TO 47 KT WHEN THE STORMS MOVED
THROUGH AT 0559Z.  ALTHOUGH SURFACE BASED INHIBITION HAS
STRENGTHENED PER MODIFICATION OF THE 00Z ABR SOUNDING FOR CURRENT
CONDITIONS...THE OBSERVED NEAR SEVERE WIND GUST AT KHON AND A NEWD
MOVEMENT OF THIS LINE AT 40 KT SUGGEST LOCALLY STRONG WIND GUSTS
WILL BE POSSIBLE INTO THE SRN PART OF WW 178 BETWEEN 08-09Z.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...FGF...ABR...BIS...

LAT...LON   46039629 45909789 46359814 46859845 47579841 47729712
            47539623 47309601 46039629

000
ACUS11 KWNS 190732
SWOMCD
SPC MCD 190732
MNZ000-NDZ000-SDZ000-190900-

MESOSCALE DISCUSSION 0693
NWS STORM PREDICTION CENTER NORMAN OK
0232 AM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN ND AND ADJACENT NWRN MN COUNTIES

CONCERNING...SEVERE THUNDERSTORM WATCH 178...

VALID 190732Z - 190900Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 178
CONTINUES.

SUMMARY...LOCALLY STRONG WIND GUSTS WILL BE POSSIBLE THROUGH 09Z
ACROSS THE SRN EXTENT OF WW 178 AS AN ARCING LINE OF STORMS IN ERN
SD MOVES INTO SERN ND AND THE ADJACENT MN COUNTIES BETWEEN 08-09Z.
THE SEVERE WEATHER THREAT IS LIKELY DIMINISHED IN THE NRN PART OF WW
178.

DISCUSSION...TRENDS IN RADAR IMAGERY OVER ERN ND INDICATED THE
STORMS THAT MOVED THROUGH THE KJMS AREA AROUND 0430Z HAVE SINCE
WEAKENED AS THEY MOVED INTO THE NWRN PART OF WW 178. A MORE STABLE
ENVIRONMENT ACROSS THE NRN PART OF THIS WATCH SUGGESTS THE SEVERE
WEATHER THREAT IS ALL BUT OVER N OF A BARNES/CASS COUNTIES ND TO
NORMAN COUNTY MN LINE.

MEANWHILE...RADAR MOSAIC INDICATED AN ARCING LINE OF STORMS
EXTENDING GENERALLY NW-SE FROM ERN SD INTO FAR SWRN MN...WITH THE
NERN SD PORTION OF THIS LINE MOVING NEWD AROUND 40 KT.  THE KHON
OBSERVATION REPORTED A WIND GUST TO 47 KT WHEN THE STORMS MOVED
THROUGH AT 0559Z.  ALTHOUGH SURFACE BASED INHIBITION HAS
STRENGTHENED PER MODIFICATION OF THE 00Z ABR SOUNDING FOR CURRENT
CONDITIONS...THE OBSERVED NEAR SEVERE WIND GUST AT KHON AND A NEWD
MOVEMENT OF THIS LINE AT 40 KT SUGGEST LOCALLY STRONG WIND GUSTS
WILL BE POSSIBLE INTO THE SRN PART OF WW 178 BETWEEN 08-09Z.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...FGF...ABR...BIS...

LAT...LON   46039629 45909789 46359814 46859845 47579841 47729712
            47539623 47309601 46039629

000
ACUS03 KWNS 190732
SWODY3
SPC AC 190730

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT SUN MAY 19 2013

VALID 211200Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER GREAT LAKES
REGION SWWD INTO CENTRAL TX...

...SYNOPSIS...
SLIGHT WEAKENING/DEAMPLIFICATION OF THE LINGERING MID- AND
UPPER-LEVEL STORM SYSTEM OVER THE CENTRAL U.S. IS FORECAST THIS
PERIOD...AS A DIGGING/STRENGTHENING TROUGH/LOW SHIFTS SSEWD INTO THE
WRN/NWRN U.S. THROUGH THE END OF THE PERIOD.  THE CENTRAL U.S.
SYSTEM WILL REMAIN THE PRIMARY DRIVER FOR THE MAJORITY OF THE
CONVECTIVE POTENTIAL THIS FORECAST.

...UPPER GREAT LAKES REGION SWWD INTO CENTRAL TX...
MODEL DIFFERENCES WITH RESPECT TO TIMING OF A SHORT-WAVE TROUGH
ROUNDING THE SRN PERIPHERY OF THE UPPER LOW AND WIDESPREAD
CONVECTIVE ACTIVITY DURING INTERVENING DAYS IS YIELDING FAIRLY
SUBSTANTIAL UNCERTAINTY WITH RESPECT TO DETAILS OF THE DAY 3
/TUESDAY/ SEVERE WEATHER POTENTIAL STRETCHING FROM THE GREAT LAKES
TO TX.

ATTM...IT APPEARS THAT A COLD FRONT -- MOVING ACROSS THE CENTRAL AND
SRN PLAINS AT THE START OF THE PERIOD -- SHOULD BEGIN TO WASH OUT AS
EWD PROGRESSION SLOWS INTO THE AFTERNOON.  WHILE CLOUDS AND ONGOING
SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT WILL LIKELY INHIBIT
HEATING/DESTABILIZATION IN SOME AREAS INTO THE
AFTERNOON...SUBSTANTIAL DESTABILIZATION IS FORECAST BY LATE
AFTERNOON -- PARTICULARLY FROM THE SERN OK/WRN AR VICINITY SWWD INTO
CENTRAL TX AHEAD OF THE DRYLINE.

BOUNDARY-LAYER CAPPING SHOULD LIMIT DEVELOPMENT INTO THE
AFTERNOON...BUT STORM DEVELOPMENT IS EVENTUALLY EXPECTED -- WITH
COVERAGE DEPENDING TO SOME DEGREE UPON TIMING OF A SHORT WAVE TROUGH
CROSSING THE SRN ROCKIES DAY 2 AND THEN SHIFTING INTO TX DAY 3.
WITH AMPLE SHEAR AND LIKELY-TO-BE STRONG INSTABILITY ACROSS THE
ARKLATEX AND INTO CENTRAL TX...SIGNIFICANT SEVERE WEATHER --
PRIMARILY VERY LARGE HAIL -- WILL BE POSSIBLE.  HOWEVER...WITH
QUESTIONS REGARDING CONVECTIVE COVERAGE/CONCENTRATION...WILL
INTRODUCE ONLY 15% SEVERE PROBABILITY ATTM.

FARTHER N -- ACROSS MO AND AS FAR NEWD AS THE UPPER GREAT LAKES
REGION...THE SCENARIO IS EVEN MORE UNCLEAR...AS MORE WIDESPREAD
STORMS ONGOING EARLY IN THE PERIOD WILL LIKELY PERSIST THROUGH THE
DAY.  THEREFORE...MORE UNCERTAIN DEGREE OF DESTABILIZATION -- AS
WELL AS GENERALLY WEAKER SHEAR DUE TO MORE MERIDIONAL/UNIDIRECTIONAL
FLOW ALOFT -- SHOULD LIMIT THREAT TO SOME DEGREE.  STILL...LOCALLY
SEVERE STORMS CAPABLE OF PRODUCING HAIL AND DAMAGING WINDS AND
POSSIBLY AN ISOLATED TORNADO CAN BE EXPECTED.  THREAT SHOULD
DIMINISH OVERNIGHT...THOUGH STORMS/LIMITED POTENTIAL FOR SEVERE
WEATHER WILL CONTINUE THROUGH THE END OF THE PERIOD.

..GOSS.. 05/19/2013

000
ACUS03 KWNS 190732
SWODY3
SPC AC 190730

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT SUN MAY 19 2013

VALID 211200Z - 221200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER GREAT LAKES
REGION SWWD INTO CENTRAL TX...

...SYNOPSIS...
SLIGHT WEAKENING/DEAMPLIFICATION OF THE LINGERING MID- AND
UPPER-LEVEL STORM SYSTEM OVER THE CENTRAL U.S. IS FORECAST THIS
PERIOD...AS A DIGGING/STRENGTHENING TROUGH/LOW SHIFTS SSEWD INTO THE
WRN/NWRN U.S. THROUGH THE END OF THE PERIOD.  THE CENTRAL U.S.
SYSTEM WILL REMAIN THE PRIMARY DRIVER FOR THE MAJORITY OF THE
CONVECTIVE POTENTIAL THIS FORECAST.

...UPPER GREAT LAKES REGION SWWD INTO CENTRAL TX...
MODEL DIFFERENCES WITH RESPECT TO TIMING OF A SHORT-WAVE TROUGH
ROUNDING THE SRN PERIPHERY OF THE UPPER LOW AND WIDESPREAD
CONVECTIVE ACTIVITY DURING INTERVENING DAYS IS YIELDING FAIRLY
SUBSTANTIAL UNCERTAINTY WITH RESPECT TO DETAILS OF THE DAY 3
/TUESDAY/ SEVERE WEATHER POTENTIAL STRETCHING FROM THE GREAT LAKES
TO TX.

ATTM...IT APPEARS THAT A COLD FRONT -- MOVING ACROSS THE CENTRAL AND
SRN PLAINS AT THE START OF THE PERIOD -- SHOULD BEGIN TO WASH OUT AS
EWD PROGRESSION SLOWS INTO THE AFTERNOON.  WHILE CLOUDS AND ONGOING
SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT WILL LIKELY INHIBIT
HEATING/DESTABILIZATION IN SOME AREAS INTO THE
AFTERNOON...SUBSTANTIAL DESTABILIZATION IS FORECAST BY LATE
AFTERNOON -- PARTICULARLY FROM THE SERN OK/WRN AR VICINITY SWWD INTO
CENTRAL TX AHEAD OF THE DRYLINE.

BOUNDARY-LAYER CAPPING SHOULD LIMIT DEVELOPMENT INTO THE
AFTERNOON...BUT STORM DEVELOPMENT IS EVENTUALLY EXPECTED -- WITH
COVERAGE DEPENDING TO SOME DEGREE UPON TIMING OF A SHORT WAVE TROUGH
CROSSING THE SRN ROCKIES DAY 2 AND THEN SHIFTING INTO TX DAY 3.
WITH AMPLE SHEAR AND LIKELY-TO-BE STRONG INSTABILITY ACROSS THE
ARKLATEX AND INTO CENTRAL TX...SIGNIFICANT SEVERE WEATHER --
PRIMARILY VERY LARGE HAIL -- WILL BE POSSIBLE.  HOWEVER...WITH
QUESTIONS REGARDING CONVECTIVE COVERAGE/CONCENTRATION...WILL
INTRODUCE ONLY 15% SEVERE PROBABILITY ATTM.

FARTHER N -- ACROSS MO AND AS FAR NEWD AS THE UPPER GREAT LAKES
REGION...THE SCENARIO IS EVEN MORE UNCLEAR...AS MORE WIDESPREAD
STORMS ONGOING EARLY IN THE PERIOD WILL LIKELY PERSIST THROUGH THE
DAY.  THEREFORE...MORE UNCERTAIN DEGREE OF DESTABILIZATION -- AS
WELL AS GENERALLY WEAKER SHEAR DUE TO MORE MERIDIONAL/UNIDIRECTIONAL
FLOW ALOFT -- SHOULD LIMIT THREAT TO SOME DEGREE.  STILL...LOCALLY
SEVERE STORMS CAPABLE OF PRODUCING HAIL AND DAMAGING WINDS AND
POSSIBLY AN ISOLATED TORNADO CAN BE EXPECTED.  THREAT SHOULD
DIMINISH OVERNIGHT...THOUGH STORMS/LIMITED POTENTIAL FOR SEVERE
WEATHER WILL CONTINUE THROUGH THE END OF THE PERIOD.

..GOSS.. 05/19/2013

000
ACUS11 KWNS 190732
SWOMCD
SPC MCD 190732
MNZ000-NDZ000-SDZ000-190900-

MESOSCALE DISCUSSION 0693
NWS STORM PREDICTION CENTER NORMAN OK
0232 AM CDT SUN MAY 19 2013

AREAS AFFECTED...SERN ND AND ADJACENT NWRN MN COUNTIES

CONCERNING...SEVERE THUNDERSTORM WATCH 178...

VALID 190732Z - 190900Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 178
CONTINUES.

SUMMARY...LOCALLY STRONG WIND GUSTS WILL BE POSSIBLE THROUGH 09Z
ACROSS THE SRN EXTENT OF WW 178 AS AN ARCING LINE OF STORMS IN ERN
SD MOVES INTO SERN ND AND THE ADJACENT MN COUNTIES BETWEEN 08-09Z.
THE SEVERE WEATHER THREAT IS LIKELY DIMINISHED IN THE NRN PART OF WW
178.

DISCUSSION...TRENDS IN RADAR IMAGERY OVER ERN ND INDICATED THE
STORMS THAT MOVED THROUGH THE KJMS AREA AROUND 0430Z HAVE SINCE
WEAKENED AS THEY MOVED INTO THE NWRN PART OF WW 178. A MORE STABLE
ENVIRONMENT ACROSS THE NRN PART OF THIS WATCH SUGGESTS THE SEVERE
WEATHER THREAT IS ALL BUT OVER N OF A BARNES/CASS COUNTIES ND TO
NORMAN COUNTY MN LINE.

MEANWHILE...RADAR MOSAIC INDICATED AN ARCING LINE OF STORMS
EXTENDING GENERALLY NW-SE FROM ERN SD INTO FAR SWRN MN...WITH THE
NERN SD PORTION OF THIS LINE MOVING NEWD AROUND 40 KT.  THE KHON
OBSERVATION REPORTED A WIND GUST TO 47 KT WHEN THE STORMS MOVED
THROUGH AT 0559Z.  ALTHOUGH SURFACE BASED INHIBITION HAS
STRENGTHENED PER MODIFICATION OF THE 00Z ABR SOUNDING FOR CURRENT
CONDITIONS...THE OBSERVED NEAR SEVERE WIND GUST AT KHON AND A NEWD
MOVEMENT OF THIS LINE AT 40 KT SUGGEST LOCALLY STRONG WIND GUSTS
WILL BE POSSIBLE INTO THE SRN PART OF WW 178 BETWEEN 08-09Z.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...FGF...ABR...BIS...

LAT...LON   46039629 45909789 46359814 46859845 47579841 47729712
            47539623 47309601 46039629

000
ACUS11 KWNS 190648
SWOMCD
SPC MCD 190648
MOZ000-IAZ000-SDZ000-190815-

MESOSCALE DISCUSSION 0692
NWS STORM PREDICTION CENTER NORMAN OK
0148 AM CDT SUN MAY 19 2013

AREAS AFFECTED...SWRN-SOUTH CENTRAL IA/FAR NWRN-NORTH CENTRAL MO

CONCERNING...SEVERE THUNDERSTORM WATCH 175...

VALID 190648Z - 190815Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 175
CONTINUES.

SUMMARY...LOCALLY STRONG WIND GUSTS REMAIN POSSIBLE AS A BOWING LINE
OF STORMS ADVANCES ENEWD AT 40-45 KT INTO SOUTH CENTRAL IA AND NORTH
CENTRAL MO.  FARTHER N...THE OVERALL SEVERE WEATHER THREAT APPEARS
TO BE WEAKENING AS THE NRN EXTENT OF THIS CONVECTION IS MOVING
SLOWER THAN THE SRN PORTION.

DISCUSSION...AT 0630Z...REGIONAL RADAR IMAGERY SHOWED A BOWING LINE
OF STORMS EXTENDING FROM SWRN IA SSEWD INTO FAR NRN MO AT 25 SW
KLWD...AND THEN TRAILING SWWD INTO THE KANSAS CITY METRO AREA AND
ADJACENT PART OF NERN KS.  THE ACTIVITY LOCATED IN DAVIESS TO WRN
HARRISON COUNTIES MO AND RINGGOLD COUNTY IA HAS THE FASTEST ENEWD
MOVEMENT AND COMBINED WITH 45 KT SSWLY LLJ EXTENDING INTO THIS AREA
SUGGESTS LOCALLY STRONG WINDS REMAIN POSSIBLE. SOUTH OF THESE
COUNTIES...THE GUST FRONT HAS BECOME MORE DISPLACED FROM THE TSTMS
SUGGESTING THE THREAT FOR STRONGER WIND GUSTS WILL TEND TO DIMINISH.
 ALTHOUGH LOCALLY STRONG WIND GUSTS REMAIN POSSIBLE IN THE SHORT
TERM /07-08Z/...THE STRENGTH OF SURFACE BASED INHIBITION WITH EWD
EXTENT SUGGESTS THE POTENTIAL SEVERE WEATHER THREAT SHOULD REMAIN
LOCALIZED AND PRECLUDES THE NEED FOR A NEW WATCH.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...DMX...EAX...FSD...OAX...

LAT...LON   39979364 39749428 40259480 40669511 41369580 42399598
            43129659 43499633 42889517 41649472 40649358 39979364

000
ACUS11 KWNS 190648
SWOMCD
SPC MCD 190648
MOZ000-IAZ000-SDZ000-190815-

MESOSCALE DISCUSSION 0692
NWS STORM PREDICTION CENTER NORMAN OK
0148 AM CDT SUN MAY 19 2013

AREAS AFFECTED...SWRN-SOUTH CENTRAL IA/FAR NWRN-NORTH CENTRAL MO

CONCERNING...SEVERE THUNDERSTORM WATCH 175...

VALID 190648Z - 190815Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 175
CONTINUES.

SUMMARY...LOCALLY STRONG WIND GUSTS REMAIN POSSIBLE AS A BOWING LINE
OF STORMS ADVANCES ENEWD AT 40-45 KT INTO SOUTH CENTRAL IA AND NORTH
CENTRAL MO.  FARTHER N...THE OVERALL SEVERE WEATHER THREAT APPEARS
TO BE WEAKENING AS THE NRN EXTENT OF THIS CONVECTION IS MOVING
SLOWER THAN THE SRN PORTION.

DISCUSSION...AT 0630Z...REGIONAL RADAR IMAGERY SHOWED A BOWING LINE
OF STORMS EXTENDING FROM SWRN IA SSEWD INTO FAR NRN MO AT 25 SW
KLWD...AND THEN TRAILING SWWD INTO THE KANSAS CITY METRO AREA AND
ADJACENT PART OF NERN KS.  THE ACTIVITY LOCATED IN DAVIESS TO WRN
HARRISON COUNTIES MO AND RINGGOLD COUNTY IA HAS THE FASTEST ENEWD
MOVEMENT AND COMBINED WITH 45 KT SSWLY LLJ EXTENDING INTO THIS AREA
SUGGESTS LOCALLY STRONG WINDS REMAIN POSSIBLE. SOUTH OF THESE
COUNTIES...THE GUST FRONT HAS BECOME MORE DISPLACED FROM THE TSTMS
SUGGESTING THE THREAT FOR STRONGER WIND GUSTS WILL TEND TO DIMINISH.
 ALTHOUGH LOCALLY STRONG WIND GUSTS REMAIN POSSIBLE IN THE SHORT
TERM /07-08Z/...THE STRENGTH OF SURFACE BASED INHIBITION WITH EWD
EXTENT SUGGESTS THE POTENTIAL SEVERE WEATHER THREAT SHOULD REMAIN
LOCALIZED AND PRECLUDES THE NEED FOR A NEW WATCH.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...DMX...EAX...FSD...OAX...

LAT...LON   39979364 39749428 40259480 40669511 41369580 42399598
            43129659 43499633 42889517 41649472 40649358 39979364

000
ACUS11 KWNS 190648
SWOMCD
SPC MCD 190648
MOZ000-IAZ000-SDZ000-190815-

MESOSCALE DISCUSSION 0692
NWS STORM PREDICTION CENTER NORMAN OK
0148 AM CDT SUN MAY 19 2013

AREAS AFFECTED...SWRN-SOUTH CENTRAL IA/FAR NWRN-NORTH CENTRAL MO

CONCERNING...SEVERE THUNDERSTORM WATCH 175...

VALID 190648Z - 190815Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 175
CONTINUES.

SUMMARY...LOCALLY STRONG WIND GUSTS REMAIN POSSIBLE AS A BOWING LINE
OF STORMS ADVANCES ENEWD AT 40-45 KT INTO SOUTH CENTRAL IA AND NORTH
CENTRAL MO.  FARTHER N...THE OVERALL SEVERE WEATHER THREAT APPEARS
TO BE WEAKENING AS THE NRN EXTENT OF THIS CONVECTION IS MOVING
SLOWER THAN THE SRN PORTION.

DISCUSSION...AT 0630Z...REGIONAL RADAR IMAGERY SHOWED A BOWING LINE
OF STORMS EXTENDING FROM SWRN IA SSEWD INTO FAR NRN MO AT 25 SW
KLWD...AND THEN TRAILING SWWD INTO THE KANSAS CITY METRO AREA AND
ADJACENT PART OF NERN KS.  THE ACTIVITY LOCATED IN DAVIESS TO WRN
HARRISON COUNTIES MO AND RINGGOLD COUNTY IA HAS THE FASTEST ENEWD
MOVEMENT AND COMBINED WITH 45 KT SSWLY LLJ EXTENDING INTO THIS AREA
SUGGESTS LOCALLY STRONG WINDS REMAIN POSSIBLE. SOUTH OF THESE
COUNTIES...THE GUST FRONT HAS BECOME MORE DISPLACED FROM THE TSTMS
SUGGESTING THE THREAT FOR STRONGER WIND GUSTS WILL TEND TO DIMINISH.
 ALTHOUGH LOCALLY STRONG WIND GUSTS REMAIN POSSIBLE IN THE SHORT
TERM /07-08Z/...THE STRENGTH OF SURFACE BASED INHIBITION WITH EWD
EXTENT SUGGESTS THE POTENTIAL SEVERE WEATHER THREAT SHOULD REMAIN
LOCALIZED AND PRECLUDES THE NEED FOR A NEW WATCH.

..PETERS/HART.. 05/19/2013

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

ATTN...WFO...DMX...EAX...FSD...OAX...

LAT...LON   39979364 39749428 40259480 40669511 41369580 42399598
            43129659 43499633 42889517 41649472 40649358 39979364

000
ACUS01 KWNS 190603
SWODY1
SPC AC 190601

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0101 AM CDT SUN MAY 19 2013

VALID 191200Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF KS/OK/MO AND
SOUTHEAST NEB...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE PLAINS TO UPPER
MIDWEST/MIDDLE MS VALLEY...

...SYNOPSIS...
ANOTHER RELATIVELY ACTIVE SEVERE WEATHER DAY IS EXPECTED ACROSS A
BROAD PORTION OF THE PLAINS/MIDWEST TODAY AND TONIGHT. THE LEAD
PORTION OF A PROMINENT UPPER TROUGH WILL SPREAD NORTHEASTWARD OVER
THE CENTRAL PLAINS...WITH AN INCREASINGLY CLOSED UPPER LOW OVER THE
NORTH-CENTRAL PLAINS/MIDDLE MO VALLEY BY TONIGHT. A CORRESPONDING
SURFACE FRONTAL ZONE WILL SLOWLY SHIFT EASTWARD ACROSS KS/NEB/SD
DURING THE PERIOD....WITH HEAT-AIDED SECONDARY SURFACE LOW
DEVELOPMENT ANTICIPATED ACROSS SOUTHERN KS/WESTERN OK/NORTHWEST TX
IN VICINITY OF A DRYLINE.

...PLAINS/OZARKS/MO VALLEY TO MIDDLE/UPPER MS VALLEY...
A PLUME OF STEEP MID-LEVEL LAPSE RATES WILL REMAIN IN PLACE /AND-OR
QUICKLY BE REESTABLISHED FROM SATURDAY PM CONVECTION/ ACROSS MOST OF
THE CENTRAL/SOUTHERN PLAINS TO THE MIDDLE MS VALLEY. A RELATIVELY
MOIST AIRMASS WITH MIDDLE/UPPER 60S AND SOME LOWER 70S F SURFACE
DEWPOINTS WILL BE IN PLACE TODAY WITHIN THE WARM SECTOR TO THE EAST
OF A NORTH-CENTRAL PLAINS COLD FRONT AND SOUTHERN PLAINS DRYLINE.

AIDED BY A SUSTAINED LOW LEVEL JET/WARM ADVECTION...SCATTERED
CONVECTION WILL LIKELY BE ONGOING EARLY TODAY ESPECIALLY ACROSS THE
MIDDLE MO VALLEY AND UPPER MIDWEST. CONVECTIVE REMNANTS/OUTFLOW
BOUNDARIES WILL BE A POTENTIAL FACTOR FOR
REDEVELOPMENT/RE-INTENSIFICATION INTO THIS AFTERNOON FOR AREAS SUCH
AS THE UPPER MIDWEST/UPPER MS VALLEY WITHIN A RELATIVELY
MOIST/UNSTABLE AIRMASS ALONG/SOUTHWEST OF A NORTHWARD-SHIFTING WARM
FRONT.

SOUTH OF THE EARLY DAY/ONGOING ACTIVITY...STRONG HEATING/AGGRESSIVE
DESTABILIZATION WILL TAKE PLACE ESPECIALLY FROM PARTS OF THE
MIDDLE/LOWER MO VALLEY INCLUDING SOUTHEAST NEB/SOUTHERN IA
SOUTH-SOUTHWESTWARD TO THE EAST OF THE DRYLINE ACROSS OK AND
NORTH-CENTRAL/WEST-CENTRAL TX. HERE...MLCAPE VALUES ARE LIKELY TO
EXCEED 3000 J/KG. AIDED BY STEADY HEIGHT FALLS AND AN INCREASING
DEEP LAYER WIND FIELD /40-45 KT EFFECTIVE SHEAR/...SURFACE BASED
TSTM/DISCRETE SUPERCELL DEVELOPMENT APPEARS MOST PROBABLE TO
INITIALLY OCCUR ACROSS AREAS SUCH AS CENTRAL/NORTHEAST KS AND
SOUTHEAST NEB INTO FAR NORTHERN OK...PERHAPS BY EARLY OR
MID-AFTERNOON. FARTHER SOUTH...NEAR/SOUTH OF THE SURFACE
LOW/FRONT/DRYLINE INDUCED TRIPLE POINT...SOMEWHAT MORE
ISOLATED/HIGHER-BASED DEEP CONVECTIVE DEVELOPMENT IS ANTICIPATED BY
LATE AFTERNOON/EARLY EVENING ACROSS CENTRAL/SOUTHERN OK SOUTHWARD
INTO NORTH/WEST-CENTRAL TX.

WITH AID OF A DIURNALLY STRONG SOUTH-SOUTHWESTERLY LOW LEVEL
JET...FORECAST SHEAR PROFILES STRONGLY FAVOR LONG-LIVED SUPERCELLS
CAPABLE OF VERY LARGE HAIL...IN ADDITION TO TORNADOES /PERHAPS ONE
OR TWO STRONG/ ESPECIALLY WHERE DEWPOINTS HOLD IN THE UPPER
60S/LOWER 70S. BY EARLY/MID-EVENING...THE PROXIMITY OF THE SLOWLY
ADVANCING COLD FRONT AND BACKING MID-LEVEL FLOW SHOULD LEAD TO
UPSCALE QUASI-LINEAR DEVELOPMENT AND AN INCREASING DAMAGING WIND
THREAT ACROSS PARTS OF THE LOWER MO VALLEY/OZARKS AND MIDWEST.
MEANWHILE...NEAR THE DRYLINE...A MORE DISCRETE MODE OF SUSTAINED
SUPERCELLS /AGAIN SOMEWHAT HIGHER-BASED ESPECIALLY WITH SOUTHWARD
EXTENT/ CAPABLE OF LARGE HAIL WILL BE THE PRIMARY CONCERN...BUT A
LIMITED TORNADO THREAT AND SOME DAMAGING WIND POTENTIAL MAY EXIST AS
WELL DURING THE LATE AFTERNOON AND EVENING HOURS.

...SOUTHEAST STATES/FL...
A REMNANT MID-LEVEL SHORTWAVE TROUGH WILL SHIFT SOUTHEASTWARD ACROSS
THIS REGION. THIS FEATURE MAY CONTRIBUTE TO SOME STRONG/POTENTIALLY
SEVERE TSTMS ON AN ISOLATED BASIS ESPECIALLY DURING THE
AFTERNOON/EARLY EVENING HOURS.

..GUYER/MARSH.. 05/19/2013

000
ACUS01 KWNS 190603
SWODY1
SPC AC 190601

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0101 AM CDT SUN MAY 19 2013

VALID 191200Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF KS/OK/MO AND
SOUTHEAST NEB...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE PLAINS TO UPPER
MIDWEST/MIDDLE MS VALLEY...

...SYNOPSIS...
ANOTHER RELATIVELY ACTIVE SEVERE WEATHER DAY IS EXPECTED ACROSS A
BROAD PORTION OF THE PLAINS/MIDWEST TODAY AND TONIGHT. THE LEAD
PORTION OF A PROMINENT UPPER TROUGH WILL SPREAD NORTHEASTWARD OVER
THE CENTRAL PLAINS...WITH AN INCREASINGLY CLOSED UPPER LOW OVER THE
NORTH-CENTRAL PLAINS/MIDDLE MO VALLEY BY TONIGHT. A CORRESPONDING
SURFACE FRONTAL ZONE WILL SLOWLY SHIFT EASTWARD ACROSS KS/NEB/SD
DURING THE PERIOD....WITH HEAT-AIDED SECONDARY SURFACE LOW
DEVELOPMENT ANTICIPATED ACROSS SOUTHERN KS/WESTERN OK/NORTHWEST TX
IN VICINITY OF A DRYLINE.

...PLAINS/OZARKS/MO VALLEY TO MIDDLE/UPPER MS VALLEY...
A PLUME OF STEEP MID-LEVEL LAPSE RATES WILL REMAIN IN PLACE /AND-OR
QUICKLY BE REESTABLISHED FROM SATURDAY PM CONVECTION/ ACROSS MOST OF
THE CENTRAL/SOUTHERN PLAINS TO THE MIDDLE MS VALLEY. A RELATIVELY
MOIST AIRMASS WITH MIDDLE/UPPER 60S AND SOME LOWER 70S F SURFACE
DEWPOINTS WILL BE IN PLACE TODAY WITHIN THE WARM SECTOR TO THE EAST
OF A NORTH-CENTRAL PLAINS COLD FRONT AND SOUTHERN PLAINS DRYLINE.

AIDED BY A SUSTAINED LOW LEVEL JET/WARM ADVECTION...SCATTERED
CONVECTION WILL LIKELY BE ONGOING EARLY TODAY ESPECIALLY ACROSS THE
MIDDLE MO VALLEY AND UPPER MIDWEST. CONVECTIVE REMNANTS/OUTFLOW
BOUNDARIES WILL BE A POTENTIAL FACTOR FOR
REDEVELOPMENT/RE-INTENSIFICATION INTO THIS AFTERNOON FOR AREAS SUCH
AS THE UPPER MIDWEST/UPPER MS VALLEY WITHIN A RELATIVELY
MOIST/UNSTABLE AIRMASS ALONG/SOUTHWEST OF A NORTHWARD-SHIFTING WARM
FRONT.

SOUTH OF THE EARLY DAY/ONGOING ACTIVITY...STRONG HEATING/AGGRESSIVE
DESTABILIZATION WILL TAKE PLACE ESPECIALLY FROM PARTS OF THE
MIDDLE/LOWER MO VALLEY INCLUDING SOUTHEAST NEB/SOUTHERN IA
SOUTH-SOUTHWESTWARD TO THE EAST OF THE DRYLINE ACROSS OK AND
NORTH-CENTRAL/WEST-CENTRAL TX. HERE...MLCAPE VALUES ARE LIKELY TO
EXCEED 3000 J/KG. AIDED BY STEADY HEIGHT FALLS AND AN INCREASING
DEEP LAYER WIND FIELD /40-45 KT EFFECTIVE SHEAR/...SURFACE BASED
TSTM/DISCRETE SUPERCELL DEVELOPMENT APPEARS MOST PROBABLE TO
INITIALLY OCCUR ACROSS AREAS SUCH AS CENTRAL/NORTHEAST KS AND
SOUTHEAST NEB INTO FAR NORTHERN OK...PERHAPS BY EARLY OR
MID-AFTERNOON. FARTHER SOUTH...NEAR/SOUTH OF THE SURFACE
LOW/FRONT/DRYLINE INDUCED TRIPLE POINT...SOMEWHAT MORE
ISOLATED/HIGHER-BASED DEEP CONVECTIVE DEVELOPMENT IS ANTICIPATED BY
LATE AFTERNOON/EARLY EVENING ACROSS CENTRAL/SOUTHERN OK SOUTHWARD
INTO NORTH/WEST-CENTRAL TX.

WITH AID OF A DIURNALLY STRONG SOUTH-SOUTHWESTERLY LOW LEVEL
JET...FORECAST SHEAR PROFILES STRONGLY FAVOR LONG-LIVED SUPERCELLS
CAPABLE OF VERY LARGE HAIL...IN ADDITION TO TORNADOES /PERHAPS ONE
OR TWO STRONG/ ESPECIALLY WHERE DEWPOINTS HOLD IN THE UPPER
60S/LOWER 70S. BY EARLY/MID-EVENING...THE PROXIMITY OF THE SLOWLY
ADVANCING COLD FRONT AND BACKING MID-LEVEL FLOW SHOULD LEAD TO
UPSCALE QUASI-LINEAR DEVELOPMENT AND AN INCREASING DAMAGING WIND
THREAT ACROSS PARTS OF THE LOWER MO VALLEY/OZARKS AND MIDWEST.
MEANWHILE...NEAR THE DRYLINE...A MORE DISCRETE MODE OF SUSTAINED
SUPERCELLS /AGAIN SOMEWHAT HIGHER-BASED ESPECIALLY WITH SOUTHWARD
EXTENT/ CAPABLE OF LARGE HAIL WILL BE THE PRIMARY CONCERN...BUT A
LIMITED TORNADO THREAT AND SOME DAMAGING WIND POTENTIAL MAY EXIST AS
WELL DURING THE LATE AFTERNOON AND EVENING HOURS.

...SOUTHEAST STATES/FL...
A REMNANT MID-LEVEL SHORTWAVE TROUGH WILL SHIFT SOUTHEASTWARD ACROSS
THIS REGION. THIS FEATURE MAY CONTRIBUTE TO SOME STRONG/POTENTIALLY
SEVERE TSTMS ON AN ISOLATED BASIS ESPECIALLY DURING THE
AFTERNOON/EARLY EVENING HOURS.

..GUYER/MARSH.. 05/19/2013

000
ACUS02 KWNS 190602
SWODY2
SPC AC 190600

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT SUN MAY 19 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM PARTS OF SERN KS/W CENTRAL
AND SWRN MO SWWD INTO CENTRAL OK...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY/UPPER
GREAT LAKES REGION SSWWD INTO N CENTRAL TX...

...SYNOPSIS...
A LARGE UPPER LOW IS FORECAST TO LINGER IN PLACE ACROSS THE SD/NEB
VICINITY...WHILE A MID-LEVEL JET STREAK AROUND THE SRN FRINGE OF THE
LOW EJECTS FROM THE SRN ROCKIES INTO THE CENTRAL U.S. DURING THE
PERIOD.  WHILE A SECOND LOW/TROUGH IS FORECAST TO APPROACH THE PAC
NW COAST LATE...THE CENTRAL U.S. STORM SYSTEM WILL BE THE SYSTEM OF
INTEREST WITH RESPECT TO SEVERE POTENTIAL ON MONDAY.

AT THE SURFACE...A LOW IS FORECAST TO REMAIN OVER THE SD VICINITY
BENEATH THE UPPER LOW...WITH A TRAILING COLD FRONT FORECAST TO SHIFT
EWD ACROSS THE PLAINS.  AS THE AFOREMENTIONED JET STREAK SHIFTS INTO
THE S CENTRAL PORTION OF THE COUNTRY...SECONDARY CYCLOGENESIS IS
FORECAST TO OCCUR ALONG THE FRONT IN THE SWRN OK VICINITY...NEAR THE
INTERSECTION OF THE FRONT AND A DEVELOPING DRYLINE.  THE COLD FRONT
AND DRYLINE SHOULD SERVE AS PRIMARY FOCI FOR AFTERNOON DEVELOPMENT
OF WIDESPREAD/SEVERE STORMS.

...UPPER MS VALLEY/UPPER GREAT LAKES SWWD INTO THE SRN PLAINS...
WHILE DETAILS REMAIN DIFFICULT TO DISCERN DUE TO MULTIPLE ROUNDS OF
WIDESPREAD/INTERVENING CONVECTION...ANOTHER SUBSTANTIAL SEVERE
WEATHER EVENT IS FORECAST MONDAY/DAY 2 ACROSS THE CENTRAL CONUS.

WEAKENING/DIMINISHING CONVECTION MAY BE ONGOING AHEAD OF THE FRONT
ACROSS THE WARM SECTOR...BUT AS STORMS/CLOUDINESS WANE THROUGH THE
MORNING IN MOST AREAS...EXPECT THE ONSET OF HEATING TO DRIVE STRONG
AIRMASS DESTABILIZATION.  BY LATE AFTERNOON...THE
PRE-FRONTAL/PRE-DRYLINE WARM SECTOR SHOULD FEATURE 2500 TO 3500 J/KG
MIXED-LAYER CAPE.  AS LARGE-SCALE ASCENT -- AIDED BY THE APPROACHING
JET STREAK AND FOCUSED ALONG LOW-LEVEL BOUNDARIES --
INCREASES...EXPECT DEVELOPMENT/RAPID GROWTH OF INITIAL CONVECTION
DURING THE MID AFTERNOON HOURS.  AS SHEAR INCREASES IN CONJUNCTION
WITH INTENSIFYING FLOW ALOFT...STORMS SHOULD RAPIDLY ACQUIRE
ROTATION -- PARTICULARLY WHERE CAPE/SHEAR JUXTAPOSITION APPEARS MOST
FAVORABLE ACROSS THE MDT RISK AREA.  HERE...THREAT FOR VERY LARGE
HAIL AND TORNADOES WILL EXIST.  THREAT FOR DAMAGING WINDS WILL
INCREASE INTO THE EVENING...AS STORMS EVOLVE INTO LINEAR CLUSTERS IN
SOME AREAS.  EVEN SO...ROTATING/SUPERCELL STORMS SHOULD LINGER
LOCALLY WELL INTO THE EVENING HOURS -- WITH CONTINUED TORNADO AND
LARGE HAIL POTENTIAL.  THREAT SHOULD FINALLY BEGIN TO DIMINISH
OVERNIGHT...AS THE AIRMASS SLOWLY COOLS/STABILIZES -- PARTICULARLY
ACROSS NRN PORTIONS OF THE RISK AREA.

..GOSS.. 05/19/2013

000
ACUS02 KWNS 190602
SWODY2
SPC AC 190600

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT SUN MAY 19 2013

VALID 201200Z - 211200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM PARTS OF SERN KS/W CENTRAL
AND SWRN MO SWWD INTO CENTRAL OK...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY/UPPER
GREAT LAKES REGION SSWWD INTO N CENTRAL TX...

...SYNOPSIS...
A LARGE UPPER LOW IS FORECAST TO LINGER IN PLACE ACROSS THE SD/NEB
VICINITY...WHILE A MID-LEVEL JET STREAK AROUND THE SRN FRINGE OF THE
LOW EJECTS FROM THE SRN ROCKIES INTO THE CENTRAL U.S. DURING THE
PERIOD.  WHILE A SECOND LOW/TROUGH IS FORECAST TO APPROACH THE PAC
NW COAST LATE...THE CENTRAL U.S. STORM SYSTEM WILL BE THE SYSTEM OF
INTEREST WITH RESPECT TO SEVERE POTENTIAL ON MONDAY.

AT THE SURFACE...A LOW IS FORECAST TO REMAIN OVER THE SD VICINITY
BENEATH THE UPPER LOW...WITH A TRAILING COLD FRONT FORECAST TO SHIFT
EWD ACROSS THE PLAINS.  AS THE AFOREMENTIONED JET STREAK SHIFTS INTO
THE S CENTRAL PORTION OF THE COUNTRY...SECONDARY CYCLOGENESIS IS
FORECAST TO OCCUR ALONG THE FRONT IN THE SWRN OK VICINITY...NEAR THE
INTERSECTION OF THE FRONT AND A DEVELOPING DRYLINE.  THE COLD FRONT
AND DRYLINE SHOULD SERVE AS PRIMARY FOCI FOR AFTERNOON DEVELOPMENT
OF WIDESPREAD/SEVERE STORMS.

...UPPER MS VALLEY/UPPER GREAT LAKES SWWD INTO THE SRN PLAINS...
WHILE DETAILS REMAIN DIFFICULT TO DISCERN DUE TO MULTIPLE ROUNDS OF
WIDESPREAD/INTERVENING CONVECTION...ANOTHER SUBSTANTIAL SEVERE
WEATHER EVENT IS FORECAST MONDAY/DAY 2 ACROSS THE CENTRAL CONUS.

WEAKENING/DIMINISHING CONVECTION MAY BE ONGOING AHEAD OF THE FRONT
ACROSS THE WARM SECTOR...BUT AS STORMS/CLOUDINESS WANE THROUGH THE
MORNING IN MOST AREAS...EXPECT THE ONSET OF HEATING TO DRIVE STRONG
AIRMASS DESTABILIZATION.  BY LATE AFTERNOON...THE
PRE-FRONTAL/PRE-DRYLINE WARM SECTOR SHOULD FEATURE 2500 TO 3500 J/KG
MIXED-LAYER CAPE.  AS LARGE-SCALE ASCENT -- AIDED BY THE APPROACHING
JET STREAK AND FOCUSED ALONG LOW-LEVEL BOUNDARIES --
INCREASES...EXPECT DEVELOPMENT/RAPID GROWTH OF INITIAL CONVECTION
DURING THE MID AFTERNOON HOURS.  AS SHEAR INCREASES IN CONJUNCTION
WITH INTENSIFYING FLOW ALOFT...STORMS SHOULD RAPIDLY ACQUIRE
ROTATION -- PARTICULARLY WHERE CAPE/SHEAR JUXTAPOSITION APPEARS MOST
FAVORABLE ACROSS THE MDT RISK AREA.  HERE...THREAT FOR VERY LARGE
HAIL AND TORNADOES WILL EXIST.  THREAT FOR DAMAGING WINDS WILL
INCREASE INTO THE EVENING...AS STORMS EVOLVE INTO LINEAR CLUSTERS IN
SOME AREAS.  EVEN SO...ROTATING/SUPERCELL STORMS SHOULD LINGER
LOCALLY WELL INTO THE EVENING HOURS -- WITH CONTINUED TORNADO AND
LARGE HAIL POTENTIAL.  THREAT SHOULD FINALLY BEGIN TO DIMINISH
OVERNIGHT...AS THE AIRMASS SLOWLY COOLS/STABILIZES -- PARTICULARLY
ACROSS NRN PORTIONS OF THE RISK AREA.

..GOSS.. 05/19/2013

000
ACUS11 KWNS 190500
SWOMCD
SPC MCD 190459
SDZ000-NDZ000-190600-

MESOSCALE DISCUSSION 0691
NWS STORM PREDICTION CENTER NORMAN OK
1159 PM CDT SAT MAY 18 2013

AREAS AFFECTED...E-CNTRL AND NERN SD

CONCERNING...SEVERE THUNDERSTORM WATCH 173...

VALID 190459Z - 190600Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 173
CONTINUES.

SUMMARY...SOME STRONG-SEVERE STORM THREAT MAY PERSIST BEYOND 0600Z
SEVERE WATCH EXPIRATION TIME.  A LOCAL WATCH EXTENSION-IN-TIME MAY
BE BEST SUITED TO ADDRESS THIS POSSIBILITY.

DISCUSSION...A BROKEN SQUALL LINE IS MOVING NEWD OVER CNTRL AND INTO
E-CNTRL SD.  FARTHER N...A CLUSTER OF SUB-SEVERE STORMS NEAR AND E
OF THE MO RIVER OVER N-CNTRL SD HAVE PROTRUDED A GUST FRONT E OF
THIS ONGOING CONVECTION.  CURRENT THINKING IS A STRONG TO PERHAPS
SEVERE WIND GUST THREAT WILL CONTINUE THROUGH 0600Z AND PERHAPS
PERSIST UNTIL THE 0700Z TIMEFRAME AS THE SQUALL LINE EVENTUALLY
MOVES PAST THE NERN PORTION OF THE WATCH.

..SMITH.. 05/19/2013

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

ATTN...WFO...FSD...ABR...BIS...

LAT...LON   43959896 44589970 45689910 45959819 44799809 43959896

000
ACUS11 KWNS 190500
SWOMCD
SPC MCD 190459
SDZ000-NDZ000-190600-

MESOSCALE DISCUSSION 0691
NWS STORM PREDICTION CENTER NORMAN OK
1159 PM CDT SAT MAY 18 2013

AREAS AFFECTED...E-CNTRL AND NERN SD

CONCERNING...SEVERE THUNDERSTORM WATCH 173...

VALID 190459Z - 190600Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 173
CONTINUES.

SUMMARY...SOME STRONG-SEVERE STORM THREAT MAY PERSIST BEYOND 0600Z
SEVERE WATCH EXPIRATION TIME.  A LOCAL WATCH EXTENSION-IN-TIME MAY
BE BEST SUITED TO ADDRESS THIS POSSIBILITY.

DISCUSSION...A BROKEN SQUALL LINE IS MOVING NEWD OVER CNTRL AND INTO
E-CNTRL SD.  FARTHER N...A CLUSTER OF SUB-SEVERE STORMS NEAR AND E
OF THE MO RIVER OVER N-CNTRL SD HAVE PROTRUDED A GUST FRONT E OF
THIS ONGOING CONVECTION.  CURRENT THINKING IS A STRONG TO PERHAPS
SEVERE WIND GUST THREAT WILL CONTINUE THROUGH 0600Z AND PERHAPS
PERSIST UNTIL THE 0700Z TIMEFRAME AS THE SQUALL LINE EVENTUALLY
MOVES PAST THE NERN PORTION OF THE WATCH.

..SMITH.. 05/19/2013

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

ATTN...WFO...FSD...ABR...BIS...

LAT...LON   43959896 44589970 45689910 45959819 44799809 43959896

000
ACUS11 KWNS 190500
SWOMCD
SPC MCD 190459
SDZ000-NDZ000-190600-

MESOSCALE DISCUSSION 0691
NWS STORM PREDICTION CENTER NORMAN OK
1159 PM CDT SAT MAY 18 2013

AREAS AFFECTED...E-CNTRL AND NERN SD

CONCERNING...SEVERE THUNDERSTORM WATCH 173...

VALID 190459Z - 190600Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 173
CONTINUES.

SUMMARY...SOME STRONG-SEVERE STORM THREAT MAY PERSIST BEYOND 0600Z
SEVERE WATCH EXPIRATION TIME.  A LOCAL WATCH EXTENSION-IN-TIME MAY
BE BEST SUITED TO ADDRESS THIS POSSIBILITY.

DISCUSSION...A BROKEN SQUALL LINE IS MOVING NEWD OVER CNTRL AND INTO
E-CNTRL SD.  FARTHER N...A CLUSTER OF SUB-SEVERE STORMS NEAR AND E
OF THE MO RIVER OVER N-CNTRL SD HAVE PROTRUDED A GUST FRONT E OF
THIS ONGOING CONVECTION.  CURRENT THINKING IS A STRONG TO PERHAPS
SEVERE WIND GUST THREAT WILL CONTINUE THROUGH 0600Z AND PERHAPS
PERSIST UNTIL THE 0700Z TIMEFRAME AS THE SQUALL LINE EVENTUALLY
MOVES PAST THE NERN PORTION OF THE WATCH.

..SMITH.. 05/19/2013

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

ATTN...WFO...FSD...ABR...BIS...

LAT...LON   43959896 44589970 45689910 45959819 44799809 43959896

000
ACUS11 KWNS 190441
SWOMCD
SPC MCD 190440
KSZ000-NEZ000-190515-

MESOSCALE DISCUSSION 0690
NWS STORM PREDICTION CENTER NORMAN OK
1140 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN NEB / NERN KS

CONCERNING...TORNADO WATCH 174...

VALID 190440Z - 190515Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 174 CONTINUES.

SUMMARY...TORNADO WATCH 174 CAN BE CANCELLED PRIOR TO THE 0800 UTC
EXPIRATION TIME AND COUNTIES CAN BE CLEARED FROM THE WATCH
CONCURRENT WITH SQUALL LINE PASSAGE.

DISCUSSION...RADAR MOSAIC SHOWS A FRACTURING QLCS FROM PARTS OF NERN
KS INTO SERN NEB.  THE REMAINING SEVERE THREAT IS LIKELY CONFINED ON
THE IMMEDIATE ERN EDGE OF THE WATCH OVER POTTAWATOMIE COUNTY KS AND
PERHAPS FARTHER NE IN MARSHALL COUNTY KS AND GAGE COUNTY NE FOR THE
NEXT 15-30 MINUTES.  OTHERWISE...THE WELL-DEVELOPED COMMA HEAD/NRN
BOOK-END VORTEX WILL BECOME INCREASINGLY DISPLACED FROM
SURFACE-BASED INFLOW...EFFECTIVELY WEAKENING IT OVER THE NEXT HOUR
OR SO.

..SMITH.. 05/19/2013

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

ATTN...WFO...OAX...TOP...ICT...GID...

LAT...LON   38539709 41119737 41359705 39769616 38579633 38539709

000
ACUS11 KWNS 190441
SWOMCD
SPC MCD 190440
KSZ000-NEZ000-190515-

MESOSCALE DISCUSSION 0690
NWS STORM PREDICTION CENTER NORMAN OK
1140 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN NEB / NERN KS

CONCERNING...TORNADO WATCH 174...

VALID 190440Z - 190515Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 174 CONTINUES.

SUMMARY...TORNADO WATCH 174 CAN BE CANCELLED PRIOR TO THE 0800 UTC
EXPIRATION TIME AND COUNTIES CAN BE CLEARED FROM THE WATCH
CONCURRENT WITH SQUALL LINE PASSAGE.

DISCUSSION...RADAR MOSAIC SHOWS A FRACTURING QLCS FROM PARTS OF NERN
KS INTO SERN NEB.  THE REMAINING SEVERE THREAT IS LIKELY CONFINED ON
THE IMMEDIATE ERN EDGE OF THE WATCH OVER POTTAWATOMIE COUNTY KS AND
PERHAPS FARTHER NE IN MARSHALL COUNTY KS AND GAGE COUNTY NE FOR THE
NEXT 15-30 MINUTES.  OTHERWISE...THE WELL-DEVELOPED COMMA HEAD/NRN
BOOK-END VORTEX WILL BECOME INCREASINGLY DISPLACED FROM
SURFACE-BASED INFLOW...EFFECTIVELY WEAKENING IT OVER THE NEXT HOUR
OR SO.

..SMITH.. 05/19/2013

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

ATTN...WFO...OAX...TOP...ICT...GID...

LAT...LON   38539709 41119737 41359705 39769616 38579633 38539709

000
ACUS11 KWNS 190441
SWOMCD
SPC MCD 190440
KSZ000-NEZ000-190515-

MESOSCALE DISCUSSION 0690
NWS STORM PREDICTION CENTER NORMAN OK
1140 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN NEB / NERN KS

CONCERNING...TORNADO WATCH 174...

VALID 190440Z - 190515Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 174 CONTINUES.

SUMMARY...TORNADO WATCH 174 CAN BE CANCELLED PRIOR TO THE 0800 UTC
EXPIRATION TIME AND COUNTIES CAN BE CLEARED FROM THE WATCH
CONCURRENT WITH SQUALL LINE PASSAGE.

DISCUSSION...RADAR MOSAIC SHOWS A FRACTURING QLCS FROM PARTS OF NERN
KS INTO SERN NEB.  THE REMAINING SEVERE THREAT IS LIKELY CONFINED ON
THE IMMEDIATE ERN EDGE OF THE WATCH OVER POTTAWATOMIE COUNTY KS AND
PERHAPS FARTHER NE IN MARSHALL COUNTY KS AND GAGE COUNTY NE FOR THE
NEXT 15-30 MINUTES.  OTHERWISE...THE WELL-DEVELOPED COMMA HEAD/NRN
BOOK-END VORTEX WILL BECOME INCREASINGLY DISPLACED FROM
SURFACE-BASED INFLOW...EFFECTIVELY WEAKENING IT OVER THE NEXT HOUR
OR SO.

..SMITH.. 05/19/2013

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

ATTN...WFO...OAX...TOP...ICT...GID...

LAT...LON   38539709 41119737 41359705 39769616 38579633 38539709

000
ACUS11 KWNS 190427
SWOMCD
SPC MCD 190427
MNZ000-NDZ000-190530-

MESOSCALE DISCUSSION 0689
NWS STORM PREDICTION CENTER NORMAN OK
1127 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN ND / PARTS OF WRN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 190427Z - 190530Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THE POSSIBILITY EXISTS FOR A FEW STRONG THUNDERSTORM WIND
GUSTS OVER SERN ND AND PARTS OF WRN MN.

DISCUSSION...RADAR MOSAIC SHOWS AN ARCING GUST FRONT FROM NEAR PIR
TO 40 MI NW ABR TO THE STUTSMAN COUNTY ROTATING STORM.  A STATIONARY
WEST-EAST ORIENTED BOUNDARY IS DRAPED ALONG THE ND-SD
BORDER...PROBABLY DELINEATING WHERE STORMS MAY TEND TO BE ELEVATED N
OF THE BOUNDARY.  STRONG LOW LEVEL SELY/S SHOWN ON THE KABR VWP
INDICATIVE OF STRONG WAA/ISENTROPIC LIFT WILL PROBABLY PROMOTE
ADDITIONAL STORM DEVELOPMENT THE NEXT FEW HOURS.  RECENT SURFACE
OBSERVATIONS OF TEMPS NEAR 80 AND DEWPOINTS IN THE UPPER 50S IMPLY
SOME SURFACE-BASED STORM THREAT S OF THE BOUNDARY BASED ON THE 00Z
ABR RAOB.  GIVEN THE PROXIMITY OF THE BOUNDARY TO THIS REGION AND
STORMS POTENTIAL ABILITY TO DRAW NEAR SURFACE-BASED AIR
PARCELS...THERE MAY BE SOME CONTINUED THREAT FOR STRONG TO PERHAPS
LOCALLY SEVERE WIND GUSTS FOR THE NEXT SEVERAL HOURS.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...FGF...BIS...

LAT...LON   47059842 47249753 47429679 46859609 46059587 45959792
            47059842

000
ACUS11 KWNS 190427
SWOMCD
SPC MCD 190427
MNZ000-NDZ000-190530-

MESOSCALE DISCUSSION 0689
NWS STORM PREDICTION CENTER NORMAN OK
1127 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN ND / PARTS OF WRN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 190427Z - 190530Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THE POSSIBILITY EXISTS FOR A FEW STRONG THUNDERSTORM WIND
GUSTS OVER SERN ND AND PARTS OF WRN MN.

DISCUSSION...RADAR MOSAIC SHOWS AN ARCING GUST FRONT FROM NEAR PIR
TO 40 MI NW ABR TO THE STUTSMAN COUNTY ROTATING STORM.  A STATIONARY
WEST-EAST ORIENTED BOUNDARY IS DRAPED ALONG THE ND-SD
BORDER...PROBABLY DELINEATING WHERE STORMS MAY TEND TO BE ELEVATED N
OF THE BOUNDARY.  STRONG LOW LEVEL SELY/S SHOWN ON THE KABR VWP
INDICATIVE OF STRONG WAA/ISENTROPIC LIFT WILL PROBABLY PROMOTE
ADDITIONAL STORM DEVELOPMENT THE NEXT FEW HOURS.  RECENT SURFACE
OBSERVATIONS OF TEMPS NEAR 80 AND DEWPOINTS IN THE UPPER 50S IMPLY
SOME SURFACE-BASED STORM THREAT S OF THE BOUNDARY BASED ON THE 00Z
ABR RAOB.  GIVEN THE PROXIMITY OF THE BOUNDARY TO THIS REGION AND
STORMS POTENTIAL ABILITY TO DRAW NEAR SURFACE-BASED AIR
PARCELS...THERE MAY BE SOME CONTINUED THREAT FOR STRONG TO PERHAPS
LOCALLY SEVERE WIND GUSTS FOR THE NEXT SEVERAL HOURS.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...FGF...BIS...

LAT...LON   47059842 47249753 47429679 46859609 46059587 45959792
            47059842

000
ACUS11 KWNS 190427
SWOMCD
SPC MCD 190427
MNZ000-NDZ000-190530-

MESOSCALE DISCUSSION 0689
NWS STORM PREDICTION CENTER NORMAN OK
1127 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN ND / PARTS OF WRN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 190427Z - 190530Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THE POSSIBILITY EXISTS FOR A FEW STRONG THUNDERSTORM WIND
GUSTS OVER SERN ND AND PARTS OF WRN MN.

DISCUSSION...RADAR MOSAIC SHOWS AN ARCING GUST FRONT FROM NEAR PIR
TO 40 MI NW ABR TO THE STUTSMAN COUNTY ROTATING STORM.  A STATIONARY
WEST-EAST ORIENTED BOUNDARY IS DRAPED ALONG THE ND-SD
BORDER...PROBABLY DELINEATING WHERE STORMS MAY TEND TO BE ELEVATED N
OF THE BOUNDARY.  STRONG LOW LEVEL SELY/S SHOWN ON THE KABR VWP
INDICATIVE OF STRONG WAA/ISENTROPIC LIFT WILL PROBABLY PROMOTE
ADDITIONAL STORM DEVELOPMENT THE NEXT FEW HOURS.  RECENT SURFACE
OBSERVATIONS OF TEMPS NEAR 80 AND DEWPOINTS IN THE UPPER 50S IMPLY
SOME SURFACE-BASED STORM THREAT S OF THE BOUNDARY BASED ON THE 00Z
ABR RAOB.  GIVEN THE PROXIMITY OF THE BOUNDARY TO THIS REGION AND
STORMS POTENTIAL ABILITY TO DRAW NEAR SURFACE-BASED AIR
PARCELS...THERE MAY BE SOME CONTINUED THREAT FOR STRONG TO PERHAPS
LOCALLY SEVERE WIND GUSTS FOR THE NEXT SEVERAL HOURS.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...FGF...BIS...

LAT...LON   47059842 47249753 47429679 46859609 46059587 45959792
            47059842

000
ACUS11 KWNS 190345
SWOMCD
SPC MCD 190344
OKZ000-190415-

MESOSCALE DISCUSSION 0688
NWS STORM PREDICTION CENTER NORMAN OK
1044 PM CDT SAT MAY 18 2013

AREAS AFFECTED...A PORTION OF S-CNTRL / CNTRL / AND NERN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 190344Z - 190415Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE THREAT FOR CONVECTIVELY-INDUCED SEVERE WIND GUSTS
CAPABLE OF ISOLD POCKETS OF WIND DAMAGE WILL PROBABLY CONTINUE FOR
THE NEXT SEVERAL HOURS.  A NEW SEVERE THUNDERSTORM WATCH IS BEING
CONSIDERED FOR PORTIONS OF OK.

DISCUSSION...A CLUSTER OF ELEVATED TSTMS LOCATED FROM THE WICHITA
MTNS TO THE OKC METRO AND RECENT ADDITIONAL STORM DEVELOPMENT IN
OSAGE COUNTY CONTINUES TO LEND A THREAT FOR STRONG-SEVERE WIND
GUSTS.  DESPITE A GUST FRONT SURGING WELL AHEAD OF THE ONGOING STORM
CLUSTER...THE CONVECTIVE DOWNDRAFTS CONTINUE TO PENETRATE TO THE
SURFACE IN THE FORM OF STRONG-SEVERE MEASURED WIND GUSTS PER
MULTIPLE OK MESONET OBSERVATIONS.  GIVEN THE VERY STEEP LAPSE RATE
ENVIRONMENT COUPLED WITH A 50+ KT LLJ...EVAPORATIVE COOLING
PROCESSES WILL BE CONDUCIVE FOR SPORADIC DOWNDRAFT BURSTS TO
PROBABLY CONTINUE TO FACILITATE POCKETS OF DAMAGING-CAPABLE WIND
GUSTS.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   34739877 35609747 36789679 36989544 36409546 35069582
            34649679 34739877

000
ACUS11 KWNS 190345
SWOMCD
SPC MCD 190344
OKZ000-190415-

MESOSCALE DISCUSSION 0688
NWS STORM PREDICTION CENTER NORMAN OK
1044 PM CDT SAT MAY 18 2013

AREAS AFFECTED...A PORTION OF S-CNTRL / CNTRL / AND NERN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 190344Z - 190415Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE THREAT FOR CONVECTIVELY-INDUCED SEVERE WIND GUSTS
CAPABLE OF ISOLD POCKETS OF WIND DAMAGE WILL PROBABLY CONTINUE FOR
THE NEXT SEVERAL HOURS.  A NEW SEVERE THUNDERSTORM WATCH IS BEING
CONSIDERED FOR PORTIONS OF OK.

DISCUSSION...A CLUSTER OF ELEVATED TSTMS LOCATED FROM THE WICHITA
MTNS TO THE OKC METRO AND RECENT ADDITIONAL STORM DEVELOPMENT IN
OSAGE COUNTY CONTINUES TO LEND A THREAT FOR STRONG-SEVERE WIND
GUSTS.  DESPITE A GUST FRONT SURGING WELL AHEAD OF THE ONGOING STORM
CLUSTER...THE CONVECTIVE DOWNDRAFTS CONTINUE TO PENETRATE TO THE
SURFACE IN THE FORM OF STRONG-SEVERE MEASURED WIND GUSTS PER
MULTIPLE OK MESONET OBSERVATIONS.  GIVEN THE VERY STEEP LAPSE RATE
ENVIRONMENT COUPLED WITH A 50+ KT LLJ...EVAPORATIVE COOLING
PROCESSES WILL BE CONDUCIVE FOR SPORADIC DOWNDRAFT BURSTS TO
PROBABLY CONTINUE TO FACILITATE POCKETS OF DAMAGING-CAPABLE WIND
GUSTS.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   34739877 35609747 36789679 36989544 36409546 35069582
            34649679 34739877

000
ACUS11 KWNS 190345
SWOMCD
SPC MCD 190344
OKZ000-190415-

MESOSCALE DISCUSSION 0688
NWS STORM PREDICTION CENTER NORMAN OK
1044 PM CDT SAT MAY 18 2013

AREAS AFFECTED...A PORTION OF S-CNTRL / CNTRL / AND NERN OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 190344Z - 190415Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE THREAT FOR CONVECTIVELY-INDUCED SEVERE WIND GUSTS
CAPABLE OF ISOLD POCKETS OF WIND DAMAGE WILL PROBABLY CONTINUE FOR
THE NEXT SEVERAL HOURS.  A NEW SEVERE THUNDERSTORM WATCH IS BEING
CONSIDERED FOR PORTIONS OF OK.

DISCUSSION...A CLUSTER OF ELEVATED TSTMS LOCATED FROM THE WICHITA
MTNS TO THE OKC METRO AND RECENT ADDITIONAL STORM DEVELOPMENT IN
OSAGE COUNTY CONTINUES TO LEND A THREAT FOR STRONG-SEVERE WIND
GUSTS.  DESPITE A GUST FRONT SURGING WELL AHEAD OF THE ONGOING STORM
CLUSTER...THE CONVECTIVE DOWNDRAFTS CONTINUE TO PENETRATE TO THE
SURFACE IN THE FORM OF STRONG-SEVERE MEASURED WIND GUSTS PER
MULTIPLE OK MESONET OBSERVATIONS.  GIVEN THE VERY STEEP LAPSE RATE
ENVIRONMENT COUPLED WITH A 50+ KT LLJ...EVAPORATIVE COOLING
PROCESSES WILL BE CONDUCIVE FOR SPORADIC DOWNDRAFT BURSTS TO
PROBABLY CONTINUE TO FACILITATE POCKETS OF DAMAGING-CAPABLE WIND
GUSTS.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...TSA...OUN...

LAT...LON   34739877 35609747 36789679 36989544 36409546 35069582
            34649679 34739877

000
ACUS11 KWNS 190314
SWOMCD
SPC MCD 190314
NDZ000-SDZ000-190415-

MESOSCALE DISCUSSION 0687
NWS STORM PREDICTION CENTER NORMAN OK
1014 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN/CNTRL SOUTH DAKOTA...AND CNTRL/ERN NORTH DAKOTA

CONCERNING...SEVERE THUNDERSTORM WATCH 172...173...

VALID 190314Z - 190415Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
172...173...CONTINUES.

SUMMARY...ISOLATED SVR TSTMS REMAIN POSSIBLE ACROSS CNTRL SOUTH
DAKOTA AND SRN/ERN NORTH DAKOTA INTO THE OVERNIGHT HOURS. THE
PRIMARY THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS.

DISCUSSION...AT 0300 UTC...STRONG TO OCCASIONALLY SEVERE TSTMS ARE
ONGOING ACROSS WW172/WW173 WITH THE STRONGEST CORES LOCATED OVER
STUTSMAN AND LOGAN COUNTIES IN CNTRL NORTH DAKOTA. THESE STRONGEST
TSTMS ARE LOCATED ALONG...AND SLIGHTLY AHEAD...OF A SFC CONFLUENCE
ZONE /EXTENDING FROM SWRN SOUTH DAKOTA TO THE NNE INTO CNTRL NORTH
DAKOTA/. MOIST LOW-LEVEL ADVECTION SHOULD PERSIST AHEAD OF THE
ONGOING TSTMS...COUPLING WITH STEEP MID-LEVEL LAPSE RATES /7-8 C/KM/
TO CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS. THIS ENVIRONMENT
WOULD TEND TO FAVOR AT LEAST AN ISOLATED SVR HAIL AND DAMAGING WIND
THREAT FOR THE NEXT SEVERAL HOURS.

FARTHER TO THE SOUTH AND WEST /ALONG THE AFOREMENTIONED SFC
CONFLUENCE ZONE/...STRONG TSTMS CONTINUE TO MOVE EWD ACROSS SOUTH
DAKOTA. THESE TSTMS ARE ALSO MOVING INTO A ENVIRONMENT SIMILAR TO
THE ONE ACROSS ERN NORTH DAKOTA WHICH WOULD SUGGEST THAT AT LEAST AN
ISOLATED SVR THREAT WILL PERSIST OVER THE NEXT SEVERAL HOURS. LARGE
HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY CONCERN. BEHIND THIS
LINE OF TSTMS /ACROSS MUCH OF WW 172/...THE ENVIRONMENT APPEARS TO
HAVE BECOME LESS FAVORABLE FOR WIDESPREAD SVR STORMS DUE TO THE
PRESENCE OF WIDESPREAD RAIN COOLED AIR. AS SUCH...WW172 WILL BE
ALLOWED TO EXPIRE AT 04UTC. ONE EXCEPTION MAY BE TRIPP COUNTY IN SRN
SOUTH DAKOTA...WHICH IS AHEAD OF THE DISCUSSED LINE OF TSTMS...AND
MAY REQUIRE A LOCAL EXTENSION IN TIME OF WW172.

..MARSH/CORFIDI.. 05/19/2013

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

LAT...LON   45170289 47090156 47830054 47899882 47239714 45499782
            43849940 43040022 43070191 43020404 45170289

000
ACUS11 KWNS 190314
SWOMCD
SPC MCD 190314
NDZ000-SDZ000-190415-

MESOSCALE DISCUSSION 0687
NWS STORM PREDICTION CENTER NORMAN OK
1014 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN/CNTRL SOUTH DAKOTA...AND CNTRL/ERN NORTH DAKOTA

CONCERNING...SEVERE THUNDERSTORM WATCH 172...173...

VALID 190314Z - 190415Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
172...173...CONTINUES.

SUMMARY...ISOLATED SVR TSTMS REMAIN POSSIBLE ACROSS CNTRL SOUTH
DAKOTA AND SRN/ERN NORTH DAKOTA INTO THE OVERNIGHT HOURS. THE
PRIMARY THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS.

DISCUSSION...AT 0300 UTC...STRONG TO OCCASIONALLY SEVERE TSTMS ARE
ONGOING ACROSS WW172/WW173 WITH THE STRONGEST CORES LOCATED OVER
STUTSMAN AND LOGAN COUNTIES IN CNTRL NORTH DAKOTA. THESE STRONGEST
TSTMS ARE LOCATED ALONG...AND SLIGHTLY AHEAD...OF A SFC CONFLUENCE
ZONE /EXTENDING FROM SWRN SOUTH DAKOTA TO THE NNE INTO CNTRL NORTH
DAKOTA/. MOIST LOW-LEVEL ADVECTION SHOULD PERSIST AHEAD OF THE
ONGOING TSTMS...COUPLING WITH STEEP MID-LEVEL LAPSE RATES /7-8 C/KM/
TO CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS. THIS ENVIRONMENT
WOULD TEND TO FAVOR AT LEAST AN ISOLATED SVR HAIL AND DAMAGING WIND
THREAT FOR THE NEXT SEVERAL HOURS.

FARTHER TO THE SOUTH AND WEST /ALONG THE AFOREMENTIONED SFC
CONFLUENCE ZONE/...STRONG TSTMS CONTINUE TO MOVE EWD ACROSS SOUTH
DAKOTA. THESE TSTMS ARE ALSO MOVING INTO A ENVIRONMENT SIMILAR TO
THE ONE ACROSS ERN NORTH DAKOTA WHICH WOULD SUGGEST THAT AT LEAST AN
ISOLATED SVR THREAT WILL PERSIST OVER THE NEXT SEVERAL HOURS. LARGE
HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY CONCERN. BEHIND THIS
LINE OF TSTMS /ACROSS MUCH OF WW 172/...THE ENVIRONMENT APPEARS TO
HAVE BECOME LESS FAVORABLE FOR WIDESPREAD SVR STORMS DUE TO THE
PRESENCE OF WIDESPREAD RAIN COOLED AIR. AS SUCH...WW172 WILL BE
ALLOWED TO EXPIRE AT 04UTC. ONE EXCEPTION MAY BE TRIPP COUNTY IN SRN
SOUTH DAKOTA...WHICH IS AHEAD OF THE DISCUSSED LINE OF TSTMS...AND
MAY REQUIRE A LOCAL EXTENSION IN TIME OF WW172.

..MARSH/CORFIDI.. 05/19/2013

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

LAT...LON   45170289 47090156 47830054 47899882 47239714 45499782
            43849940 43040022 43070191 43020404 45170289

000
ACUS11 KWNS 190314
SWOMCD
SPC MCD 190314
NDZ000-SDZ000-190415-

MESOSCALE DISCUSSION 0687
NWS STORM PREDICTION CENTER NORMAN OK
1014 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN/CNTRL SOUTH DAKOTA...AND CNTRL/ERN NORTH DAKOTA

CONCERNING...SEVERE THUNDERSTORM WATCH 172...173...

VALID 190314Z - 190415Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
172...173...CONTINUES.

SUMMARY...ISOLATED SVR TSTMS REMAIN POSSIBLE ACROSS CNTRL SOUTH
DAKOTA AND SRN/ERN NORTH DAKOTA INTO THE OVERNIGHT HOURS. THE
PRIMARY THREAT WILL BE LARGE HAIL AND DAMAGING WIND GUSTS.

DISCUSSION...AT 0300 UTC...STRONG TO OCCASIONALLY SEVERE TSTMS ARE
ONGOING ACROSS WW172/WW173 WITH THE STRONGEST CORES LOCATED OVER
STUTSMAN AND LOGAN COUNTIES IN CNTRL NORTH DAKOTA. THESE STRONGEST
TSTMS ARE LOCATED ALONG...AND SLIGHTLY AHEAD...OF A SFC CONFLUENCE
ZONE /EXTENDING FROM SWRN SOUTH DAKOTA TO THE NNE INTO CNTRL NORTH
DAKOTA/. MOIST LOW-LEVEL ADVECTION SHOULD PERSIST AHEAD OF THE
ONGOING TSTMS...COUPLING WITH STEEP MID-LEVEL LAPSE RATES /7-8 C/KM/
TO CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS. THIS ENVIRONMENT
WOULD TEND TO FAVOR AT LEAST AN ISOLATED SVR HAIL AND DAMAGING WIND
THREAT FOR THE NEXT SEVERAL HOURS.

FARTHER TO THE SOUTH AND WEST /ALONG THE AFOREMENTIONED SFC
CONFLUENCE ZONE/...STRONG TSTMS CONTINUE TO MOVE EWD ACROSS SOUTH
DAKOTA. THESE TSTMS ARE ALSO MOVING INTO A ENVIRONMENT SIMILAR TO
THE ONE ACROSS ERN NORTH DAKOTA WHICH WOULD SUGGEST THAT AT LEAST AN
ISOLATED SVR THREAT WILL PERSIST OVER THE NEXT SEVERAL HOURS. LARGE
HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY CONCERN. BEHIND THIS
LINE OF TSTMS /ACROSS MUCH OF WW 172/...THE ENVIRONMENT APPEARS TO
HAVE BECOME LESS FAVORABLE FOR WIDESPREAD SVR STORMS DUE TO THE
PRESENCE OF WIDESPREAD RAIN COOLED AIR. AS SUCH...WW172 WILL BE
ALLOWED TO EXPIRE AT 04UTC. ONE EXCEPTION MAY BE TRIPP COUNTY IN SRN
SOUTH DAKOTA...WHICH IS AHEAD OF THE DISCUSSED LINE OF TSTMS...AND
MAY REQUIRE A LOCAL EXTENSION IN TIME OF WW172.

..MARSH/CORFIDI.. 05/19/2013

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

LAT...LON   45170289 47090156 47830054 47899882 47239714 45499782
            43849940 43040022 43070191 43020404 45170289

000
ACUS11 KWNS 190300
SWOMCD
SPC MCD 190300
MOZ000-KSZ000-NEZ000-190330-

MESOSCALE DISCUSSION 0686
NWS STORM PREDICTION CENTER NORMAN OK
1000 PM CDT SAT MAY 18 2013

AREAS AFFECTED...E-CNTRL AND NERN KS / FAR WRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 190300Z - 190330Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SWATHS OF STRONG TO LOCALLY SEVERE WIND GUSTS ARE
SEEMINGLY LIKELY CONCURRENT WITH THE PASSAGE OF THE QLCS FROM THE
WEST.  A SEVERE WATCH WILL LIKELY BE COORDINATED FOR ERN KS AND FAR
WRN MO OVER THE NEXT 30-60 MINUTES.

DISCUSSION...RADAR MOSAIC SHOWS AN EXTENSIVE NORTH-SOUTH ORIENTED
QLCS WITH SEVERAL SMALLER-SCALE BOWING STRUCTURES IN ADDITION TO AN
EMBEDDED SUPERCELL OVER OTTAWA COUNTY.  DESPITE APPRECIABLE CINH DUE
TO A GRADUALLY COOLING BOUNDARY LAYER...VERY STEEP LAPSE RATES IN
THE H7-H5 LAYER /AOA 9 DEG C PER KM/ SHOULD ACT TO SUSTAIN THIS QLCS
INTO ERN KS AND OUT OF TORNADO WATCH 170 AND 174 BY THE 04-05Z
PERIOD.  LINEAR EXTRAPOLATION SUGGESTS THIS QLCS WILL BE AFFECTING
TOPEKA AROUND 0500Z-0530Z AND THE GREATER KANSAS CITY METRO DURING
THE 06-07Z PERIOD.  IN ADDITION TO THE THREAT FOR ISOLD DMGG
WINDS...A NON-ZERO TORNADO THREAT WOULD SEEMINGLY EXIST WITH ANY
LONGER-LIVED EMBEDDED SUPERCELL MESOCYCLONE OR APPRECIABLY MORE
INTENSE QLCS-GENERATED MESOVORTEX.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...SGF...EAX...OAX...TOP...ICT...

LAT...LON   38289641 39859622 40079489 39599442 38999429 38469436
            38049480 37789602 38289641

000
ACUS11 KWNS 190300
SWOMCD
SPC MCD 190300
MOZ000-KSZ000-NEZ000-190330-

MESOSCALE DISCUSSION 0686
NWS STORM PREDICTION CENTER NORMAN OK
1000 PM CDT SAT MAY 18 2013

AREAS AFFECTED...E-CNTRL AND NERN KS / FAR WRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 190300Z - 190330Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SWATHS OF STRONG TO LOCALLY SEVERE WIND GUSTS ARE
SEEMINGLY LIKELY CONCURRENT WITH THE PASSAGE OF THE QLCS FROM THE
WEST.  A SEVERE WATCH WILL LIKELY BE COORDINATED FOR ERN KS AND FAR
WRN MO OVER THE NEXT 30-60 MINUTES.

DISCUSSION...RADAR MOSAIC SHOWS AN EXTENSIVE NORTH-SOUTH ORIENTED
QLCS WITH SEVERAL SMALLER-SCALE BOWING STRUCTURES IN ADDITION TO AN
EMBEDDED SUPERCELL OVER OTTAWA COUNTY.  DESPITE APPRECIABLE CINH DUE
TO A GRADUALLY COOLING BOUNDARY LAYER...VERY STEEP LAPSE RATES IN
THE H7-H5 LAYER /AOA 9 DEG C PER KM/ SHOULD ACT TO SUSTAIN THIS QLCS
INTO ERN KS AND OUT OF TORNADO WATCH 170 AND 174 BY THE 04-05Z
PERIOD.  LINEAR EXTRAPOLATION SUGGESTS THIS QLCS WILL BE AFFECTING
TOPEKA AROUND 0500Z-0530Z AND THE GREATER KANSAS CITY METRO DURING
THE 06-07Z PERIOD.  IN ADDITION TO THE THREAT FOR ISOLD DMGG
WINDS...A NON-ZERO TORNADO THREAT WOULD SEEMINGLY EXIST WITH ANY
LONGER-LIVED EMBEDDED SUPERCELL MESOCYCLONE OR APPRECIABLY MORE
INTENSE QLCS-GENERATED MESOVORTEX.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...SGF...EAX...OAX...TOP...ICT...

LAT...LON   38289641 39859622 40079489 39599442 38999429 38469436
            38049480 37789602 38289641

000
ACUS11 KWNS 190300
SWOMCD
SPC MCD 190300
MOZ000-KSZ000-NEZ000-190330-

MESOSCALE DISCUSSION 0686
NWS STORM PREDICTION CENTER NORMAN OK
1000 PM CDT SAT MAY 18 2013

AREAS AFFECTED...E-CNTRL AND NERN KS / FAR WRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 190300Z - 190330Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...SWATHS OF STRONG TO LOCALLY SEVERE WIND GUSTS ARE
SEEMINGLY LIKELY CONCURRENT WITH THE PASSAGE OF THE QLCS FROM THE
WEST.  A SEVERE WATCH WILL LIKELY BE COORDINATED FOR ERN KS AND FAR
WRN MO OVER THE NEXT 30-60 MINUTES.

DISCUSSION...RADAR MOSAIC SHOWS AN EXTENSIVE NORTH-SOUTH ORIENTED
QLCS WITH SEVERAL SMALLER-SCALE BOWING STRUCTURES IN ADDITION TO AN
EMBEDDED SUPERCELL OVER OTTAWA COUNTY.  DESPITE APPRECIABLE CINH DUE
TO A GRADUALLY COOLING BOUNDARY LAYER...VERY STEEP LAPSE RATES IN
THE H7-H5 LAYER /AOA 9 DEG C PER KM/ SHOULD ACT TO SUSTAIN THIS QLCS
INTO ERN KS AND OUT OF TORNADO WATCH 170 AND 174 BY THE 04-05Z
PERIOD.  LINEAR EXTRAPOLATION SUGGESTS THIS QLCS WILL BE AFFECTING
TOPEKA AROUND 0500Z-0530Z AND THE GREATER KANSAS CITY METRO DURING
THE 06-07Z PERIOD.  IN ADDITION TO THE THREAT FOR ISOLD DMGG
WINDS...A NON-ZERO TORNADO THREAT WOULD SEEMINGLY EXIST WITH ANY
LONGER-LIVED EMBEDDED SUPERCELL MESOCYCLONE OR APPRECIABLY MORE
INTENSE QLCS-GENERATED MESOVORTEX.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...SGF...EAX...OAX...TOP...ICT...

LAT...LON   38289641 39859622 40079489 39599442 38999429 38469436
            38049480 37789602 38289641

000
ACUS11 KWNS 190203
SWOMCD
SPC MCD 190203
OKZ000-TXZ000-190300-

MESOSCALE DISCUSSION 0685
NWS STORM PREDICTION CENTER NORMAN OK
0903 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN AND CNTRL OKLAHOMA AND NW TEXAS

CONCERNING...TORNADO WATCH 171...

VALID 190203Z - 190300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 171 CONTINUES.

SUMMARY...SVR TSTMS ARE ONGOING ACROSS PORTIONS OF SWRN OKLAHOMA AND
NW TEXAS. THESE TSTMS SHOULD PERSIST THROUGH THE EVENING...INTO THE
OVERNIGHT...POSING A THREAT FOR LARGE HAIL...STRONG DAMAGING
WINDS...AND POSSIBLE TORNADOES.

DISCUSSION...AT 0145 UTC...RADAR OBSERVATIONS SHOWED A LARGE CLUSTER
OF TSTMS LOCATED ACROSS SWRN OKLAHOMA AND A COUPLE OF MORE ISOLATED
TSTMS IN FAR NW TEXAS. THE TSTMS ACROSS SWRN OKLAHOMA HAVE DEVELOPED
IN A VERY UNSTABLE ENVIRONMENT /MUCAPE VALUES AOA 3000 J/KG/ AND
MODEST DEEP-LAYER SHEAR /AROUND 35-40 KTS/. ALTHOUGH SEVERAL OF
THESE WRN OK TSTMS ARE CURRENTLY SUPERCELLS...RECENT RADAR TRENDS
INDICATES A CONGEALING OF COLD POOLS WHICH WOULD SUGGEST THAT
UPSCALE GROWTH TO MCS MAY BE UNDERWAY. THIS DEVELOPING MCS SHOULD
BEGIN TO MOVE EWD THROUGH THE EVENING AND WILL BEGIN TO AFFECT THE
OKC METRO IN THE NEXT 1-2 HRS. GIVEN THE INCREASING 0-1 KM AND 0-3
KM HELICITIES...ONGOING VIGOROUS UPDRAFTS...AND AN ENVIRONMENT
CONDUCIVE FOR SUSTAINING VIGOROUS UPDRAFTS...LARGE HAIL...STRONG
DAMAGING WINDS...AND TORNADOES CANNOT BE RULED OUT.

FARTHER S...ACROSS NW TX...MORE ISOLATED SUPERCELLS ARE MOVING NNE
INTO SWRN OKLAHOMA AND WILL CONTINUE TO POSE A THREAT OF LARGE
HAIL...DAMAGING WINDS...AND POSSIBLE TORNADOES. THESE SUPERCELLS
SHOULD MERGE INTO THE DEVELOPING OKLAHOMA MCS OVER THE COURSE OF THE
NEXT SEVERAL HRS.

..MARSH.. 05/19/2013

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

ATTN...WFO...TSA...FWD...OUN...SJT...LUB...AMA...MAF...

LAT...LON   36970094 36969665 34889675 33459799 33379895 31459909
            31700082 34730040 36970094

000
ACUS11 KWNS 190203
SWOMCD
SPC MCD 190203
OKZ000-TXZ000-190300-

MESOSCALE DISCUSSION 0685
NWS STORM PREDICTION CENTER NORMAN OK
0903 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN AND CNTRL OKLAHOMA AND NW TEXAS

CONCERNING...TORNADO WATCH 171...

VALID 190203Z - 190300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 171 CONTINUES.

SUMMARY...SVR TSTMS ARE ONGOING ACROSS PORTIONS OF SWRN OKLAHOMA AND
NW TEXAS. THESE TSTMS SHOULD PERSIST THROUGH THE EVENING...INTO THE
OVERNIGHT...POSING A THREAT FOR LARGE HAIL...STRONG DAMAGING
WINDS...AND POSSIBLE TORNADOES.

DISCUSSION...AT 0145 UTC...RADAR OBSERVATIONS SHOWED A LARGE CLUSTER
OF TSTMS LOCATED ACROSS SWRN OKLAHOMA AND A COUPLE OF MORE ISOLATED
TSTMS IN FAR NW TEXAS. THE TSTMS ACROSS SWRN OKLAHOMA HAVE DEVELOPED
IN A VERY UNSTABLE ENVIRONMENT /MUCAPE VALUES AOA 3000 J/KG/ AND
MODEST DEEP-LAYER SHEAR /AROUND 35-40 KTS/. ALTHOUGH SEVERAL OF
THESE WRN OK TSTMS ARE CURRENTLY SUPERCELLS...RECENT RADAR TRENDS
INDICATES A CONGEALING OF COLD POOLS WHICH WOULD SUGGEST THAT
UPSCALE GROWTH TO MCS MAY BE UNDERWAY. THIS DEVELOPING MCS SHOULD
BEGIN TO MOVE EWD THROUGH THE EVENING AND WILL BEGIN TO AFFECT THE
OKC METRO IN THE NEXT 1-2 HRS. GIVEN THE INCREASING 0-1 KM AND 0-3
KM HELICITIES...ONGOING VIGOROUS UPDRAFTS...AND AN ENVIRONMENT
CONDUCIVE FOR SUSTAINING VIGOROUS UPDRAFTS...LARGE HAIL...STRONG
DAMAGING WINDS...AND TORNADOES CANNOT BE RULED OUT.

FARTHER S...ACROSS NW TX...MORE ISOLATED SUPERCELLS ARE MOVING NNE
INTO SWRN OKLAHOMA AND WILL CONTINUE TO POSE A THREAT OF LARGE
HAIL...DAMAGING WINDS...AND POSSIBLE TORNADOES. THESE SUPERCELLS
SHOULD MERGE INTO THE DEVELOPING OKLAHOMA MCS OVER THE COURSE OF THE
NEXT SEVERAL HRS.

..MARSH.. 05/19/2013

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

ATTN...WFO...TSA...FWD...OUN...SJT...LUB...AMA...MAF...

LAT...LON   36970094 36969665 34889675 33459799 33379895 31459909
            31700082 34730040 36970094

000
ACUS11 KWNS 190203
SWOMCD
SPC MCD 190203
OKZ000-TXZ000-190300-

MESOSCALE DISCUSSION 0685
NWS STORM PREDICTION CENTER NORMAN OK
0903 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN AND CNTRL OKLAHOMA AND NW TEXAS

CONCERNING...TORNADO WATCH 171...

VALID 190203Z - 190300Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 171 CONTINUES.

SUMMARY...SVR TSTMS ARE ONGOING ACROSS PORTIONS OF SWRN OKLAHOMA AND
NW TEXAS. THESE TSTMS SHOULD PERSIST THROUGH THE EVENING...INTO THE
OVERNIGHT...POSING A THREAT FOR LARGE HAIL...STRONG DAMAGING
WINDS...AND POSSIBLE TORNADOES.

DISCUSSION...AT 0145 UTC...RADAR OBSERVATIONS SHOWED A LARGE CLUSTER
OF TSTMS LOCATED ACROSS SWRN OKLAHOMA AND A COUPLE OF MORE ISOLATED
TSTMS IN FAR NW TEXAS. THE TSTMS ACROSS SWRN OKLAHOMA HAVE DEVELOPED
IN A VERY UNSTABLE ENVIRONMENT /MUCAPE VALUES AOA 3000 J/KG/ AND
MODEST DEEP-LAYER SHEAR /AROUND 35-40 KTS/. ALTHOUGH SEVERAL OF
THESE WRN OK TSTMS ARE CURRENTLY SUPERCELLS...RECENT RADAR TRENDS
INDICATES A CONGEALING OF COLD POOLS WHICH WOULD SUGGEST THAT
UPSCALE GROWTH TO MCS MAY BE UNDERWAY. THIS DEVELOPING MCS SHOULD
BEGIN TO MOVE EWD THROUGH THE EVENING AND WILL BEGIN TO AFFECT THE
OKC METRO IN THE NEXT 1-2 HRS. GIVEN THE INCREASING 0-1 KM AND 0-3
KM HELICITIES...ONGOING VIGOROUS UPDRAFTS...AND AN ENVIRONMENT
CONDUCIVE FOR SUSTAINING VIGOROUS UPDRAFTS...LARGE HAIL...STRONG
DAMAGING WINDS...AND TORNADOES CANNOT BE RULED OUT.

FARTHER S...ACROSS NW TX...MORE ISOLATED SUPERCELLS ARE MOVING NNE
INTO SWRN OKLAHOMA AND WILL CONTINUE TO POSE A THREAT OF LARGE
HAIL...DAMAGING WINDS...AND POSSIBLE TORNADOES. THESE SUPERCELLS
SHOULD MERGE INTO THE DEVELOPING OKLAHOMA MCS OVER THE COURSE OF THE
NEXT SEVERAL HRS.

..MARSH.. 05/19/2013

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

ATTN...WFO...TSA...FWD...OUN...SJT...LUB...AMA...MAF...

LAT...LON   36970094 36969665 34889675 33459799 33379895 31459909
            31700082 34730040 36970094

000
ACUS11 KWNS 190134
SWOMCD
SPC MCD 190133
IAZ000-MOZ000-NEZ000-MNZ000-SDZ000-190330-

MESOSCALE DISCUSSION 0684
NWS STORM PREDICTION CENTER NORMAN OK
0833 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN SD / ERN NE / FAR NWRN MO / WRN IA / FAR SWRN
MN

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 190133Z - 190330Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STRONG TO SEVERE STORMS CAPABLE OF DAMAGING WIND GUSTS AND
LOCALIZED LARGE HAIL WILL LIKELY MOVE NEWD FROM NE INTO SERN SD AND
ADJACENT PORTIONS OF IA/MN.  THE AREA IS BEING STRONGLY CONSIDERED
FOR A SEVERE THUNDERSTORM WATCH.

DISCUSSION...ORGANIZING BROKEN QLCS OVER S-CNTRL NE AND THE NE
SANDHILLS WILL PROBABLY CONTINUE TO CONSOLIDATE AND MATURE AS IT
MOVES NE ACROSS NRN AND ERN NE OVER THE NEXT FEW HOURS.  SURFACE
OBSERVATIONS OVER N-CNTRL NE AND SERN SD SHOW AN AREA OF PRESSURE
FALLS WITH DEWPOINTS IN THE LOWER TO MID 60S DEG F.  A PRESSURE
FALL/RISE COUPLET APPEARS TO BE DEVELOPING WITH 1-3 MB/HR RISES
NOTED BEHIND THE STORMS OVER NE.

THE 00Z/19 OAX RAOB SHOWED VERY STEEP H7-H5 LAPSE RATES /9 DEG C PER
KM/ RESULTING IN A MODERATELY UNSTABLE AIRMASS DOWNSTREAM OF THE
ONGOING ACTIVITY.  FORECAST SOUNDINGS OVER SERN SD EXHIBIT A SIMILAR
MOISTURE/LAPSE RATE PROFILE.  25-35 KT 0-6 KM SHEAR WILL FACILITATE
ORGANIZED LINE SEGMENTS POTENTIALLY CAPABLE OF ISOLD SEVERE
DOWNDRAFTS AND LOCALIZED LARGE HAIL.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...DMX...EAX...FSD...OAX...ABR...LBF...UNR...

LAT...LON   43190016 44269840 43769565 41009467 40129599 42869819
            43190016

000
ACUS11 KWNS 190134
SWOMCD
SPC MCD 190133
IAZ000-MOZ000-NEZ000-MNZ000-SDZ000-190330-

MESOSCALE DISCUSSION 0684
NWS STORM PREDICTION CENTER NORMAN OK
0833 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN SD / ERN NE / FAR NWRN MO / WRN IA / FAR SWRN
MN

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 190133Z - 190330Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STRONG TO SEVERE STORMS CAPABLE OF DAMAGING WIND GUSTS AND
LOCALIZED LARGE HAIL WILL LIKELY MOVE NEWD FROM NE INTO SERN SD AND
ADJACENT PORTIONS OF IA/MN.  THE AREA IS BEING STRONGLY CONSIDERED
FOR A SEVERE THUNDERSTORM WATCH.

DISCUSSION...ORGANIZING BROKEN QLCS OVER S-CNTRL NE AND THE NE
SANDHILLS WILL PROBABLY CONTINUE TO CONSOLIDATE AND MATURE AS IT
MOVES NE ACROSS NRN AND ERN NE OVER THE NEXT FEW HOURS.  SURFACE
OBSERVATIONS OVER N-CNTRL NE AND SERN SD SHOW AN AREA OF PRESSURE
FALLS WITH DEWPOINTS IN THE LOWER TO MID 60S DEG F.  A PRESSURE
FALL/RISE COUPLET APPEARS TO BE DEVELOPING WITH 1-3 MB/HR RISES
NOTED BEHIND THE STORMS OVER NE.

THE 00Z/19 OAX RAOB SHOWED VERY STEEP H7-H5 LAPSE RATES /9 DEG C PER
KM/ RESULTING IN A MODERATELY UNSTABLE AIRMASS DOWNSTREAM OF THE
ONGOING ACTIVITY.  FORECAST SOUNDINGS OVER SERN SD EXHIBIT A SIMILAR
MOISTURE/LAPSE RATE PROFILE.  25-35 KT 0-6 KM SHEAR WILL FACILITATE
ORGANIZED LINE SEGMENTS POTENTIALLY CAPABLE OF ISOLD SEVERE
DOWNDRAFTS AND LOCALIZED LARGE HAIL.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...DMX...EAX...FSD...OAX...ABR...LBF...UNR...

LAT...LON   43190016 44269840 43769565 41009467 40129599 42869819
            43190016

000
ACUS11 KWNS 190134
SWOMCD
SPC MCD 190133
IAZ000-MOZ000-NEZ000-MNZ000-SDZ000-190330-

MESOSCALE DISCUSSION 0684
NWS STORM PREDICTION CENTER NORMAN OK
0833 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SERN SD / ERN NE / FAR NWRN MO / WRN IA / FAR SWRN
MN

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 190133Z - 190330Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STRONG TO SEVERE STORMS CAPABLE OF DAMAGING WIND GUSTS AND
LOCALIZED LARGE HAIL WILL LIKELY MOVE NEWD FROM NE INTO SERN SD AND
ADJACENT PORTIONS OF IA/MN.  THE AREA IS BEING STRONGLY CONSIDERED
FOR A SEVERE THUNDERSTORM WATCH.

DISCUSSION...ORGANIZING BROKEN QLCS OVER S-CNTRL NE AND THE NE
SANDHILLS WILL PROBABLY CONTINUE TO CONSOLIDATE AND MATURE AS IT
MOVES NE ACROSS NRN AND ERN NE OVER THE NEXT FEW HOURS.  SURFACE
OBSERVATIONS OVER N-CNTRL NE AND SERN SD SHOW AN AREA OF PRESSURE
FALLS WITH DEWPOINTS IN THE LOWER TO MID 60S DEG F.  A PRESSURE
FALL/RISE COUPLET APPEARS TO BE DEVELOPING WITH 1-3 MB/HR RISES
NOTED BEHIND THE STORMS OVER NE.

THE 00Z/19 OAX RAOB SHOWED VERY STEEP H7-H5 LAPSE RATES /9 DEG C PER
KM/ RESULTING IN A MODERATELY UNSTABLE AIRMASS DOWNSTREAM OF THE
ONGOING ACTIVITY.  FORECAST SOUNDINGS OVER SERN SD EXHIBIT A SIMILAR
MOISTURE/LAPSE RATE PROFILE.  25-35 KT 0-6 KM SHEAR WILL FACILITATE
ORGANIZED LINE SEGMENTS POTENTIALLY CAPABLE OF ISOLD SEVERE
DOWNDRAFTS AND LOCALIZED LARGE HAIL.

..SMITH/CORFIDI.. 05/19/2013

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

ATTN...WFO...DMX...EAX...FSD...OAX...ABR...LBF...UNR...

LAT...LON   43190016 44269840 43769565 41009467 40129599 42869819
            43190016

000
ACUS01 KWNS 190103
SWODY1
SPC AC 190100

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0800 PM CDT SAT MAY 18 2013

VALID 190100Z - 191200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF OK/KS/NEB...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE PLAINS...

...PLAINS...
IN ACCORDANCE WITH A STRONG ELEVATED MIXED LAYER AND A GENERAL
PREVALENCE OF 60S F SURFACE DEWPOINTS /WITH SOME LOWER 70S ACROSS OK
INTO EAST-CENTRAL KS/...00Z REGIONAL SOUNDINGS SAMPLE A VERY
FAVORABLE THERMODYNAMIC ENVIRONMENT FOR CONTINUED SEVERE TSTMS
THROUGH TONIGHT. A MIXED CONVECTIVE MODE INCLUDING INTENSE
SUPERCELLS WILL PERSIST ESPECIALLY THROUGH MID-EVENING...WITH
TORNADIC SUPERCELLS REMAINING A DISTINCT CONCERN WITH THE MOST
PROBABLE AREA FOR A STRONG TORNADO BEING IN CENTRAL KS.

HOWEVER...A READILY APPARENT TREND IS TOWARD SEVERAL GROUPINGS OF
UPSCALE INTENSIFY/CONGEALING STORMS FROM SOUTHWEST/WEST-CENTRAL OK
INTO CENTRAL KS/WESTERN NEB EARLY THIS EVENING. IN GENERAL...THIS IS
LIKELY A FACTOR OF BACKED /SOUTHWESTERLY/ MID-LEVEL WINDS AND
SOMEWHAT WEAK HIGH LEVEL FLOW PER 00Z REGIONAL SOUNDINGS.
ACCORDINGLY...UPSCALE QUASI-LINEAR GROWTH IS LIKELY THE REMAINDER OF
THE NIGHT. ALREADY NOTED IN DERIVED WIND DATA...THIS WILL BE AIDED
BY A STRENGTHENING SOUTHERLY LOW LEVEL JET ACROSS OK/KS INTO
SOUTHEAST NEB AND OTHER PARTS OF THE MIDDLE MO VALLEY. DAMAGING
WINDS SHOULD EVOLVE TO BE THE PRIMARY CONCERN TONIGHT ESPECIALLY
ACROSS PARTS OF OK INTO CENTRAL/PARTS EASTERN KS AND SOUTHEAST
NEB...WITH STRENGTHENING LOW LEVEL SHEAR/INTENSE LAPSE RATES
SUPPORTING BOW ECHO MATURATION/POSSIBLE MESOVORTICES CAPABLE OF A
FEW TORNADOES ASIDE FROM A DISTINCT WIND THREAT/SOME HAIL.

...OZARKS/MID-SOUTH/TN VALLEY/SOUTHEAST...
WARM ADVECTION/ISENTROPIC ASCENT MAY ALLOW FOR ISOLATED TSTMS TO
PERSIST OR DEVELOP ON THE EASTERN EDGE OF A STRONG ELEVATED MIX
LAYER OVER THE CENTRAL CONUS. SOME HAIL MIGHT BE POSSIBLE...BUT
GENERAL PRESENCE OF SHORTWAVE RIDING/WEAK DEEP LAYER SHEAR WILL
LIKELY KEEP ANY SUCH POTENTIAL VERY MARGINAL.

..GUYER.. 05/19/2013

000
ACUS01 KWNS 190103
SWODY1
SPC AC 190100

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0800 PM CDT SAT MAY 18 2013

VALID 190100Z - 191200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF OK/KS/NEB...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE PLAINS...

...PLAINS...
IN ACCORDANCE WITH A STRONG ELEVATED MIXED LAYER AND A GENERAL
PREVALENCE OF 60S F SURFACE DEWPOINTS /WITH SOME LOWER 70S ACROSS OK
INTO EAST-CENTRAL KS/...00Z REGIONAL SOUNDINGS SAMPLE A VERY
FAVORABLE THERMODYNAMIC ENVIRONMENT FOR CONTINUED SEVERE TSTMS
THROUGH TONIGHT. A MIXED CONVECTIVE MODE INCLUDING INTENSE
SUPERCELLS WILL PERSIST ESPECIALLY THROUGH MID-EVENING...WITH
TORNADIC SUPERCELLS REMAINING A DISTINCT CONCERN WITH THE MOST
PROBABLE AREA FOR A STRONG TORNADO BEING IN CENTRAL KS.

HOWEVER...A READILY APPARENT TREND IS TOWARD SEVERAL GROUPINGS OF
UPSCALE INTENSIFY/CONGEALING STORMS FROM SOUTHWEST/WEST-CENTRAL OK
INTO CENTRAL KS/WESTERN NEB EARLY THIS EVENING. IN GENERAL...THIS IS
LIKELY A FACTOR OF BACKED /SOUTHWESTERLY/ MID-LEVEL WINDS AND
SOMEWHAT WEAK HIGH LEVEL FLOW PER 00Z REGIONAL SOUNDINGS.
ACCORDINGLY...UPSCALE QUASI-LINEAR GROWTH IS LIKELY THE REMAINDER OF
THE NIGHT. ALREADY NOTED IN DERIVED WIND DATA...THIS WILL BE AIDED
BY A STRENGTHENING SOUTHERLY LOW LEVEL JET ACROSS OK/KS INTO
SOUTHEAST NEB AND OTHER PARTS OF THE MIDDLE MO VALLEY. DAMAGING
WINDS SHOULD EVOLVE TO BE THE PRIMARY CONCERN TONIGHT ESPECIALLY
ACROSS PARTS OF OK INTO CENTRAL/PARTS EASTERN KS AND SOUTHEAST
NEB...WITH STRENGTHENING LOW LEVEL SHEAR/INTENSE LAPSE RATES
SUPPORTING BOW ECHO MATURATION/POSSIBLE MESOVORTICES CAPABLE OF A
FEW TORNADOES ASIDE FROM A DISTINCT WIND THREAT/SOME HAIL.

...OZARKS/MID-SOUTH/TN VALLEY/SOUTHEAST...
WARM ADVECTION/ISENTROPIC ASCENT MAY ALLOW FOR ISOLATED TSTMS TO
PERSIST OR DEVELOP ON THE EASTERN EDGE OF A STRONG ELEVATED MIX
LAYER OVER THE CENTRAL CONUS. SOME HAIL MIGHT BE POSSIBLE...BUT
GENERAL PRESENCE OF SHORTWAVE RIDING/WEAK DEEP LAYER SHEAR WILL
LIKELY KEEP ANY SUCH POTENTIAL VERY MARGINAL.

..GUYER.. 05/19/2013

000
ACUS11 KWNS 190041
SWOMCD
SPC MCD 190040
KSZ000-OKZ000-190145-

MESOSCALE DISCUSSION 0683
NWS STORM PREDICTION CENTER NORMAN OK
0740 PM CDT SAT MAY 18 2013

AREAS AFFECTED...CNTRL AND S-CNTRL KS

CONCERNING...TORNADO WATCH 170...

VALID 190040Z - 190145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 170 CONTINUES.

SUMMARY...THE LOW LEVEL WIND PROFILE IS BEGINNING TO INTENSIFY
ACROSS CNTRL KS.  UPSCALE GROWTH INTO A FORWARD PROPAGATING BOW
APPEARS TO BE OCCURRING AND WILL MOVE ACROSS S-CNTRL KS DURING THE
NEXT SEVERAL HOURS.

DISCUSSION...RADAR MOSAIC SHOWS 3 MAIN STORMS OR CLUSTERS OF STORMS
IN A NORTH-SOUTH ORIENTATION OVER CNTRL KS AS OF 0040Z.  THESE
STORMS ARE BEGINNING TO INGEST RICHER BOUNDARY LAYER MOISTURE AS THE
STORMS CONTINUE MOVING TO THE NE AT 30 KT.  A LONG ESTABLISHED
SUPERCELL OVER ELLIS COUNTY WILL MOVE INTO RUSSELL/LINCOLN/MITCHELL
COUNTIES.  SURFACE CONDITIONS AHEAD OF THIS POTENTIALLY TORNADIC
STORM ARE IN THE UPPER 70S WITH UPPER 60S DEWPOINTS...WHICH HAVE LED
TO AN EXTREMELY UNSTABLE AIRMASS SAMPLED BY THE 00Z/19 TOP RAOB
/4300 J/KG MLCAPE/.  STRONG MASS FLUX IS FOCUSED INTO THE REGION
AHEAD OF THIS SUPERCELL IN N-CNTRL KS AND SERN NE.  AS THE LLJ
CONTINUES TO STRENGTHEN THIS EVENING...CYCLING LOW LEVEL
MESOCYCLONES WITH THIS STORM WILL LIKELY CONTINUE TO POSE SOME
TORNADO THREAT...IN ADDITION TO LARGE HAIL/DMGG WINDS.

FARTHER S...LESS REFINED STORM STRUCTURE OVER
EDWARDS/KIOWA/COMANCHE/CLARK COUNTIES IS BEGINNING TO SHOW SOME
UPSCALE GROWTH TENDENCY.  AS SUCH...THESE MESSY MODE STRUCTURES WILL
PROBABLY HAVE DIFFICULTY EVOLVING INTO QUASI-DISCRETE SUPERCELLS
FROM HERE FORWARD.  NONETHELESS...STRENGTHENING LOW LEVEL WIND
PROFILE AT HVL PROFILER /40 KT AT 0.5 KM AGL/ WILL AID IN STORM
ORGANIZATION.  AN EVENTUAL BOWING COMPLEX WITH EMBEDDED CIRCULATIONS
WILL FAVOR DMGG WINDS...BUT LARGE HAIL AND A TORNADO OR TWO ARE
POSSIBLE WITH THE STRONGER CORES.

..SMITH.. 05/19/2013

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

ATTN...WFO...TOP...ICT...OUN...GID...DDC...

LAT...LON   37029968 39179906 39409752 38899712 37439728 36919841
            37029968

000
ACUS11 KWNS 190041
SWOMCD
SPC MCD 190040
KSZ000-OKZ000-190145-

MESOSCALE DISCUSSION 0683
NWS STORM PREDICTION CENTER NORMAN OK
0740 PM CDT SAT MAY 18 2013

AREAS AFFECTED...CNTRL AND S-CNTRL KS

CONCERNING...TORNADO WATCH 170...

VALID 190040Z - 190145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 170 CONTINUES.

SUMMARY...THE LOW LEVEL WIND PROFILE IS BEGINNING TO INTENSIFY
ACROSS CNTRL KS.  UPSCALE GROWTH INTO A FORWARD PROPAGATING BOW
APPEARS TO BE OCCURRING AND WILL MOVE ACROSS S-CNTRL KS DURING THE
NEXT SEVERAL HOURS.

DISCUSSION...RADAR MOSAIC SHOWS 3 MAIN STORMS OR CLUSTERS OF STORMS
IN A NORTH-SOUTH ORIENTATION OVER CNTRL KS AS OF 0040Z.  THESE
STORMS ARE BEGINNING TO INGEST RICHER BOUNDARY LAYER MOISTURE AS THE
STORMS CONTINUE MOVING TO THE NE AT 30 KT.  A LONG ESTABLISHED
SUPERCELL OVER ELLIS COUNTY WILL MOVE INTO RUSSELL/LINCOLN/MITCHELL
COUNTIES.  SURFACE CONDITIONS AHEAD OF THIS POTENTIALLY TORNADIC
STORM ARE IN THE UPPER 70S WITH UPPER 60S DEWPOINTS...WHICH HAVE LED
TO AN EXTREMELY UNSTABLE AIRMASS SAMPLED BY THE 00Z/19 TOP RAOB
/4300 J/KG MLCAPE/.  STRONG MASS FLUX IS FOCUSED INTO THE REGION
AHEAD OF THIS SUPERCELL IN N-CNTRL KS AND SERN NE.  AS THE LLJ
CONTINUES TO STRENGTHEN THIS EVENING...CYCLING LOW LEVEL
MESOCYCLONES WITH THIS STORM WILL LIKELY CONTINUE TO POSE SOME
TORNADO THREAT...IN ADDITION TO LARGE HAIL/DMGG WINDS.

FARTHER S...LESS REFINED STORM STRUCTURE OVER
EDWARDS/KIOWA/COMANCHE/CLARK COUNTIES IS BEGINNING TO SHOW SOME
UPSCALE GROWTH TENDENCY.  AS SUCH...THESE MESSY MODE STRUCTURES WILL
PROBABLY HAVE DIFFICULTY EVOLVING INTO QUASI-DISCRETE SUPERCELLS
FROM HERE FORWARD.  NONETHELESS...STRENGTHENING LOW LEVEL WIND
PROFILE AT HVL PROFILER /40 KT AT 0.5 KM AGL/ WILL AID IN STORM
ORGANIZATION.  AN EVENTUAL BOWING COMPLEX WITH EMBEDDED CIRCULATIONS
WILL FAVOR DMGG WINDS...BUT LARGE HAIL AND A TORNADO OR TWO ARE
POSSIBLE WITH THE STRONGER CORES.

..SMITH.. 05/19/2013

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

ATTN...WFO...TOP...ICT...OUN...GID...DDC...

LAT...LON   37029968 39179906 39409752 38899712 37439728 36919841
            37029968

000
ACUS11 KWNS 190041
SWOMCD
SPC MCD 190040
KSZ000-OKZ000-190145-

MESOSCALE DISCUSSION 0683
NWS STORM PREDICTION CENTER NORMAN OK
0740 PM CDT SAT MAY 18 2013

AREAS AFFECTED...CNTRL AND S-CNTRL KS

CONCERNING...TORNADO WATCH 170...

VALID 190040Z - 190145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 170 CONTINUES.

SUMMARY...THE LOW LEVEL WIND PROFILE IS BEGINNING TO INTENSIFY
ACROSS CNTRL KS.  UPSCALE GROWTH INTO A FORWARD PROPAGATING BOW
APPEARS TO BE OCCURRING AND WILL MOVE ACROSS S-CNTRL KS DURING THE
NEXT SEVERAL HOURS.

DISCUSSION...RADAR MOSAIC SHOWS 3 MAIN STORMS OR CLUSTERS OF STORMS
IN A NORTH-SOUTH ORIENTATION OVER CNTRL KS AS OF 0040Z.  THESE
STORMS ARE BEGINNING TO INGEST RICHER BOUNDARY LAYER MOISTURE AS THE
STORMS CONTINUE MOVING TO THE NE AT 30 KT.  A LONG ESTABLISHED
SUPERCELL OVER ELLIS COUNTY WILL MOVE INTO RUSSELL/LINCOLN/MITCHELL
COUNTIES.  SURFACE CONDITIONS AHEAD OF THIS POTENTIALLY TORNADIC
STORM ARE IN THE UPPER 70S WITH UPPER 60S DEWPOINTS...WHICH HAVE LED
TO AN EXTREMELY UNSTABLE AIRMASS SAMPLED BY THE 00Z/19 TOP RAOB
/4300 J/KG MLCAPE/.  STRONG MASS FLUX IS FOCUSED INTO THE REGION
AHEAD OF THIS SUPERCELL IN N-CNTRL KS AND SERN NE.  AS THE LLJ
CONTINUES TO STRENGTHEN THIS EVENING...CYCLING LOW LEVEL
MESOCYCLONES WITH THIS STORM WILL LIKELY CONTINUE TO POSE SOME
TORNADO THREAT...IN ADDITION TO LARGE HAIL/DMGG WINDS.

FARTHER S...LESS REFINED STORM STRUCTURE OVER
EDWARDS/KIOWA/COMANCHE/CLARK COUNTIES IS BEGINNING TO SHOW SOME
UPSCALE GROWTH TENDENCY.  AS SUCH...THESE MESSY MODE STRUCTURES WILL
PROBABLY HAVE DIFFICULTY EVOLVING INTO QUASI-DISCRETE SUPERCELLS
FROM HERE FORWARD.  NONETHELESS...STRENGTHENING LOW LEVEL WIND
PROFILE AT HVL PROFILER /40 KT AT 0.5 KM AGL/ WILL AID IN STORM
ORGANIZATION.  AN EVENTUAL BOWING COMPLEX WITH EMBEDDED CIRCULATIONS
WILL FAVOR DMGG WINDS...BUT LARGE HAIL AND A TORNADO OR TWO ARE
POSSIBLE WITH THE STRONGER CORES.

..SMITH.. 05/19/2013

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

ATTN...WFO...TOP...ICT...OUN...GID...DDC...

LAT...LON   37029968 39179906 39409752 38899712 37439728 36919841
            37029968

000
ACUS11 KWNS 182342
SWOMCD
SPC MCD 182342
KSZ000-NEZ000-190015-

MESOSCALE DISCUSSION 0682
NWS STORM PREDICTION CENTER NORMAN OK
0642 PM CDT SAT MAY 18 2013

AREAS AFFECTED...CNTRL AND S-CNTRL NE / FAR N-CNTRL KS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 182342Z - 190015Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A DMGG WIND...LARGE HAIL...AND POSSIBLY A TORNADO THREAT
WILL EVENTUALLY MOVE OUT OF WW 170 AND INTO PORTIONS OF CNTRL NE SWD
INTO FAR N-CNTRL KS.  EITHER A WATCH EXTENSION-IN-AREA OR AN
ADDITIONAL WATCH WILL BE NEEDED TO ADDRESS THIS THREAT.

DISCUSSION...RADAR MOSAIC SHOWS A CLUSTER OF STRONG-SEVERE STORMS
NEAR THE N-CNTRL KS/S-CNTRL NE STATE LINE AND THESE STORMS ARE
MOVING NEWD AND EVENTUALLY MOVE INTO NE CURRENTLY OUTSIDE OF TORNADO
WATCH 170.  THE ENVIRONMENT DOWNSTREAM OF THESE STORMS WILL BE
SUPPORTIVE OF DMGG WIND GUSTS...LARGE HAIL AND POSSIBLY A
TORNADO...GIVEN THE ADEQUATE SHEAR PROFILES AND AVAILABLE
INSTABILITY IN PLACE OVER THE REGION.  AS SUCH...EXPECTING AT LEAST
A LARGE HAIL AND DMGG WIND GUST THREAT TO MOVE INTO THE AREA FROM
THE SW.

..SMITH/CORFIDI.. 05/18/2013

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

ATTN...WFO...OAX...TOP...GID...LBF...

LAT...LON   39609849 41170010 41830000 41979891 41179798 40089736
            39529756 39609849

000
ACUS11 KWNS 182342
SWOMCD
SPC MCD 182342
KSZ000-NEZ000-190015-

MESOSCALE DISCUSSION 0682
NWS STORM PREDICTION CENTER NORMAN OK
0642 PM CDT SAT MAY 18 2013

AREAS AFFECTED...CNTRL AND S-CNTRL NE / FAR N-CNTRL KS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 182342Z - 190015Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A DMGG WIND...LARGE HAIL...AND POSSIBLY A TORNADO THREAT
WILL EVENTUALLY MOVE OUT OF WW 170 AND INTO PORTIONS OF CNTRL NE SWD
INTO FAR N-CNTRL KS.  EITHER A WATCH EXTENSION-IN-AREA OR AN
ADDITIONAL WATCH WILL BE NEEDED TO ADDRESS THIS THREAT.

DISCUSSION...RADAR MOSAIC SHOWS A CLUSTER OF STRONG-SEVERE STORMS
NEAR THE N-CNTRL KS/S-CNTRL NE STATE LINE AND THESE STORMS ARE
MOVING NEWD AND EVENTUALLY MOVE INTO NE CURRENTLY OUTSIDE OF TORNADO
WATCH 170.  THE ENVIRONMENT DOWNSTREAM OF THESE STORMS WILL BE
SUPPORTIVE OF DMGG WIND GUSTS...LARGE HAIL AND POSSIBLY A
TORNADO...GIVEN THE ADEQUATE SHEAR PROFILES AND AVAILABLE
INSTABILITY IN PLACE OVER THE REGION.  AS SUCH...EXPECTING AT LEAST
A LARGE HAIL AND DMGG WIND GUST THREAT TO MOVE INTO THE AREA FROM
THE SW.

..SMITH/CORFIDI.. 05/18/2013

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

ATTN...WFO...OAX...TOP...GID...LBF...

LAT...LON   39609849 41170010 41830000 41979891 41179798 40089736
            39529756 39609849

000
ACUS11 KWNS 182312
SWOMCD
SPC MCD 182311
MNZ000-SDZ000-190045-

MESOSCALE DISCUSSION 0681
NWS STORM PREDICTION CENTER NORMAN OK
0611 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN MINNESOTA...AND ERN SOUTH DAKOTA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 182311Z - 190045Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED TSTMS HAVE DEVELOPED ACROSS WRN MINNESOTA.
ALTHOUGH AN ISOLATED SVR HAIL AND/OR DAMAGING WIND GUST IS
POSSIBLE...OVERALL COVERAGE AND INTENSITY SHOULD PRECLUDE THE NEED
FOR A WW.

DISCUSSION...A FEW TSTMS HAVE DEVELOPED ACROSS WRN MINNESOTA IN A
ZONE OF WEAK SFC CONFLUENCE ALONG A REMNANT STATIONARY FRONT. RECENT
OBSERVATIONS SUGGEST THESE STORMS ARE DEVELOPING IN A REGION OF SE
SFC WINDS AND MODEST MID-LEVEL FLOW /AROUND 30 KTS PER WDL
PROFILER/...YIELDING EFFECTIVE BULK SHEAR OF AROUND 30-35 KTS.
THIS...COUPLED WITH MODERATE INSTABILITY /MUCAPE VALUES OF AROUND
2000 J/KG/ WILL SUPPORT ISOLATED TSTMS INTO THE EARLY/MID EVENING.
GIVEN THE ENVIRONMENT...TRANSIENT SUPERCELL-LIKE STRUCTURES WILL BE
POSSIBLE...WITH AN ISOLATED LARGE HAIL AND/OR DAMAGING WIND REPORT
THE PRIMARY THREAT...ALTHOUGH A BRIEF TORNADO CANNOT BE RULED OUT.
THE LACK OF LARGE SCALE FOCI FOR MAINTENANCE/REDEVELOPMENT SHOULD
PRECLUDE WIDESPREAD TSTM ORGANIZATION BEFORE TSTMS WEAKEN/DISSIPATE
AFTER SUNSET. GIVEN THE RELATIVELY SHORT DURATION...SMALL
COVERAGE...AND EXPECTED LACK OF TSTM ORGANIZATION...A WW IS NOT
ANTICIPATED ATTM.

..MARSH/CORFIDI.. 05/18/2013

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

ATTN...WFO...MPX...FSD...ABR...

LAT...LON   44869758 45179686 45659578 45839472 45719398 45269391
            44609445 44199595 44179712 44439789 44709803 44869758

000
ACUS11 KWNS 182312
SWOMCD
SPC MCD 182311
MNZ000-SDZ000-190045-

MESOSCALE DISCUSSION 0681
NWS STORM PREDICTION CENTER NORMAN OK
0611 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN MINNESOTA...AND ERN SOUTH DAKOTA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 182311Z - 190045Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED TSTMS HAVE DEVELOPED ACROSS WRN MINNESOTA.
ALTHOUGH AN ISOLATED SVR HAIL AND/OR DAMAGING WIND GUST IS
POSSIBLE...OVERALL COVERAGE AND INTENSITY SHOULD PRECLUDE THE NEED
FOR A WW.

DISCUSSION...A FEW TSTMS HAVE DEVELOPED ACROSS WRN MINNESOTA IN A
ZONE OF WEAK SFC CONFLUENCE ALONG A REMNANT STATIONARY FRONT. RECENT
OBSERVATIONS SUGGEST THESE STORMS ARE DEVELOPING IN A REGION OF SE
SFC WINDS AND MODEST MID-LEVEL FLOW /AROUND 30 KTS PER WDL
PROFILER/...YIELDING EFFECTIVE BULK SHEAR OF AROUND 30-35 KTS.
THIS...COUPLED WITH MODERATE INSTABILITY /MUCAPE VALUES OF AROUND
2000 J/KG/ WILL SUPPORT ISOLATED TSTMS INTO THE EARLY/MID EVENING.
GIVEN THE ENVIRONMENT...TRANSIENT SUPERCELL-LIKE STRUCTURES WILL BE
POSSIBLE...WITH AN ISOLATED LARGE HAIL AND/OR DAMAGING WIND REPORT
THE PRIMARY THREAT...ALTHOUGH A BRIEF TORNADO CANNOT BE RULED OUT.
THE LACK OF LARGE SCALE FOCI FOR MAINTENANCE/REDEVELOPMENT SHOULD
PRECLUDE WIDESPREAD TSTM ORGANIZATION BEFORE TSTMS WEAKEN/DISSIPATE
AFTER SUNSET. GIVEN THE RELATIVELY SHORT DURATION...SMALL
COVERAGE...AND EXPECTED LACK OF TSTM ORGANIZATION...A WW IS NOT
ANTICIPATED ATTM.

..MARSH/CORFIDI.. 05/18/2013

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

ATTN...WFO...MPX...FSD...ABR...

LAT...LON   44869758 45179686 45659578 45839472 45719398 45269391
            44609445 44199595 44179712 44439789 44709803 44869758

000
ACUS11 KWNS 182312
SWOMCD
SPC MCD 182311
MNZ000-SDZ000-190045-

MESOSCALE DISCUSSION 0681
NWS STORM PREDICTION CENTER NORMAN OK
0611 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN MINNESOTA...AND ERN SOUTH DAKOTA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 182311Z - 190045Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED TSTMS HAVE DEVELOPED ACROSS WRN MINNESOTA.
ALTHOUGH AN ISOLATED SVR HAIL AND/OR DAMAGING WIND GUST IS
POSSIBLE...OVERALL COVERAGE AND INTENSITY SHOULD PRECLUDE THE NEED
FOR A WW.

DISCUSSION...A FEW TSTMS HAVE DEVELOPED ACROSS WRN MINNESOTA IN A
ZONE OF WEAK SFC CONFLUENCE ALONG A REMNANT STATIONARY FRONT. RECENT
OBSERVATIONS SUGGEST THESE STORMS ARE DEVELOPING IN A REGION OF SE
SFC WINDS AND MODEST MID-LEVEL FLOW /AROUND 30 KTS PER WDL
PROFILER/...YIELDING EFFECTIVE BULK SHEAR OF AROUND 30-35 KTS.
THIS...COUPLED WITH MODERATE INSTABILITY /MUCAPE VALUES OF AROUND
2000 J/KG/ WILL SUPPORT ISOLATED TSTMS INTO THE EARLY/MID EVENING.
GIVEN THE ENVIRONMENT...TRANSIENT SUPERCELL-LIKE STRUCTURES WILL BE
POSSIBLE...WITH AN ISOLATED LARGE HAIL AND/OR DAMAGING WIND REPORT
THE PRIMARY THREAT...ALTHOUGH A BRIEF TORNADO CANNOT BE RULED OUT.
THE LACK OF LARGE SCALE FOCI FOR MAINTENANCE/REDEVELOPMENT SHOULD
PRECLUDE WIDESPREAD TSTM ORGANIZATION BEFORE TSTMS WEAKEN/DISSIPATE
AFTER SUNSET. GIVEN THE RELATIVELY SHORT DURATION...SMALL
COVERAGE...AND EXPECTED LACK OF TSTM ORGANIZATION...A WW IS NOT
ANTICIPATED ATTM.

..MARSH/CORFIDI.. 05/18/2013

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

ATTN...WFO...MPX...FSD...ABR...

LAT...LON   44869758 45179686 45659578 45839472 45719398 45269391
            44609445 44199595 44179712 44439789 44709803 44869758

000
ACUS11 KWNS 182252
SWOMCD
SPC MCD 182252
OKZ000-182345-

MESOSCALE DISCUSSION 0680
NWS STORM PREDICTION CENTER NORMAN OK
0552 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN OK

CONCERNING...TORNADO WATCH 171...

VALID 182252Z - 182345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 171 CONTINUES.

SUMMARY...LARGE TO VERY LARGE HAIL AND SEVERE WIND GUST THREAT WILL
LIKELY BE THE MAIN THREATS FOR THE NEXT HOUR OR SO OVER WRN OK.  THE
POTENTIAL FOR A TORNADIC SUPERCELL OR TWO WOULD SEEMINGLY INCREASE
IN THE 00Z-02Z PERIOD AS STORMS MOVE TO THE NE AT 20 KT.

DISCUSSION...RADAR MOSAIC SHOWS A SMALL CLUSTER OF SEVERE STORMS
OCCASIONALLY ACQUIRING SUPERCELL CHARACTERISTICS AS THE STORMS MOVE
TO THE NE AT 20 KT OVER SWRN OK.  THE KFDR VWP ONLY SHOWS AROUND
30-35 KT 0-6 KM SHEAR...LENDING SOME LIMITATION TO GREATER SUPERCELL
STRUCTURE LONGEVITY.  NONETHELESS...THE AIRMASS OVER WRN OK FEATURES
VERY STEEP LAPSE RATES AND WILL FAVOR LARGE TO VERY LARGE HAIL
GROWTH WITH THE MORE INTENSE UPDRAFTS.  CURRENT THINKING IS AN
EVENTUAL MORE ROBUST STORM OR TWO WILL EVENTUALLY EVOLVE FROM THIS
CLUSTER OF STORMS.  AS DEEP LAYER SHEAR IMPROVES SLIGHTLY THIS
EVENING...THE REMAINING INTENSE UPDRAFTS WILL BECOME INTENSE
SUPERCELLS WITH STORM-SCALE ROTATION INCREASING IN TANDEM WITH A LLJ
FORECAST TO STRENGTHEN TO 40 KT BY 00-01Z.  AS NEAR-SURFACE WINDS
BACK SLIGHTLY THIS EVENING...RICHER MOISTURE WILL SLOWLY MOVE WWD
AND IMPROVE PROSPECTS FOR A TORNADIC SUPERCELL AS BOUNDARY LAYER RH
INCREASES.

..SMITH.. 05/18/2013

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

ATTN...WFO...OUN...

LAT...LON   34729977 36449930 36539816 34849867 34539926 34729977

000
ACUS11 KWNS 182252
SWOMCD
SPC MCD 182252
OKZ000-182345-

MESOSCALE DISCUSSION 0680
NWS STORM PREDICTION CENTER NORMAN OK
0552 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN OK

CONCERNING...TORNADO WATCH 171...

VALID 182252Z - 182345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 171 CONTINUES.

SUMMARY...LARGE TO VERY LARGE HAIL AND SEVERE WIND GUST THREAT WILL
LIKELY BE THE MAIN THREATS FOR THE NEXT HOUR OR SO OVER WRN OK.  THE
POTENTIAL FOR A TORNADIC SUPERCELL OR TWO WOULD SEEMINGLY INCREASE
IN THE 00Z-02Z PERIOD AS STORMS MOVE TO THE NE AT 20 KT.

DISCUSSION...RADAR MOSAIC SHOWS A SMALL CLUSTER OF SEVERE STORMS
OCCASIONALLY ACQUIRING SUPERCELL CHARACTERISTICS AS THE STORMS MOVE
TO THE NE AT 20 KT OVER SWRN OK.  THE KFDR VWP ONLY SHOWS AROUND
30-35 KT 0-6 KM SHEAR...LENDING SOME LIMITATION TO GREATER SUPERCELL
STRUCTURE LONGEVITY.  NONETHELESS...THE AIRMASS OVER WRN OK FEATURES
VERY STEEP LAPSE RATES AND WILL FAVOR LARGE TO VERY LARGE HAIL
GROWTH WITH THE MORE INTENSE UPDRAFTS.  CURRENT THINKING IS AN
EVENTUAL MORE ROBUST STORM OR TWO WILL EVENTUALLY EVOLVE FROM THIS
CLUSTER OF STORMS.  AS DEEP LAYER SHEAR IMPROVES SLIGHTLY THIS
EVENING...THE REMAINING INTENSE UPDRAFTS WILL BECOME INTENSE
SUPERCELLS WITH STORM-SCALE ROTATION INCREASING IN TANDEM WITH A LLJ
FORECAST TO STRENGTHEN TO 40 KT BY 00-01Z.  AS NEAR-SURFACE WINDS
BACK SLIGHTLY THIS EVENING...RICHER MOISTURE WILL SLOWLY MOVE WWD
AND IMPROVE PROSPECTS FOR A TORNADIC SUPERCELL AS BOUNDARY LAYER RH
INCREASES.

..SMITH.. 05/18/2013

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

ATTN...WFO...OUN...

LAT...LON   34729977 36449930 36539816 34849867 34539926 34729977

000
ACUS11 KWNS 182225
SWOMCD
SPC MCD 182224
NDZ000-SDZ000-182330-

MESOSCALE DISCUSSION 0679
NWS STORM PREDICTION CENTER NORMAN OK
0524 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SRN NORTH DAKOTA...CNTRL AND NORTH CNTRL SOUTH
DAKOTA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 182224Z - 182330Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...TSTMS ARE EXPECTED TO CONTINUE TO DEVELOP THROUGH THE
AFTERNOON AND INTO THE EVENING ACROSS SRN NORTH DAKOTA...SWD INTO
CNTRL SOUTH DAKOTA. LARGE HAIL AND ISOLATED DAMAGING WIND GUSTS WILL
BE POSSIBLE WITH THE STRONGER STORMS. A WW MAY BECOME NECESSARY
LATER THIS AFTERNOON OR EVENING.

DISCUSSION...BROAD ASCENT IS OVERSPREADING PORTIONS OF THE NRN HIGH
PLAINS IN CONJUNCTION WITH A SUBTLE SHORT-WAVE TROUGH EJECTING NNE
TO THE EAST OF A LARGER-SCALE CYCLONE ACROSS THE WRN CONUS. THIS
ASCENT SHOULD ACT TO WEAKEN CINH ALLOWING FOR THE DEVELOPMENT OF
TSTMS ACROSS SRN NORTH DAKOTA AND CNTRL SOUTH DAKOTA. THE
ENVIRONMENT ACROSS THIS AREA IS CHARACTERIZED BY MUCAPE AOA 1000
J/KG AND EFFECTIVE BULK SHEAR AOA 30 KTS WHICH IS SUPPORTIVE OF
SUPERCELLS. ADDITIONALLY...STRONG/SVR TSTMS TO THE SW /ACROSS WW172/
MAY EVENTUALLY MOVE INTO THIS AREA. AS SUCH A WW MAY BECOME
NECESSARY LATER THIS AFTERNOON...WITH LARGE HAIL AND ISOLATED
DAMAGING WIND GUSTS AS THE PRIMARY THREATS.

..MARSH/CORFIDI.. 05/18/2013

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

LAT...LON   45010111 45920200 45960400 47060397 47530331 47760217
            47730086 47629934 46869818 45949798 44659868 43749966
            43910108 45010111

000
ACUS11 KWNS 182225
SWOMCD
SPC MCD 182224
NDZ000-SDZ000-182330-

MESOSCALE DISCUSSION 0679
NWS STORM PREDICTION CENTER NORMAN OK
0524 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SRN NORTH DAKOTA...CNTRL AND NORTH CNTRL SOUTH
DAKOTA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 182224Z - 182330Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...TSTMS ARE EXPECTED TO CONTINUE TO DEVELOP THROUGH THE
AFTERNOON AND INTO THE EVENING ACROSS SRN NORTH DAKOTA...SWD INTO
CNTRL SOUTH DAKOTA. LARGE HAIL AND ISOLATED DAMAGING WIND GUSTS WILL
BE POSSIBLE WITH THE STRONGER STORMS. A WW MAY BECOME NECESSARY
LATER THIS AFTERNOON OR EVENING.

DISCUSSION...BROAD ASCENT IS OVERSPREADING PORTIONS OF THE NRN HIGH
PLAINS IN CONJUNCTION WITH A SUBTLE SHORT-WAVE TROUGH EJECTING NNE
TO THE EAST OF A LARGER-SCALE CYCLONE ACROSS THE WRN CONUS. THIS
ASCENT SHOULD ACT TO WEAKEN CINH ALLOWING FOR THE DEVELOPMENT OF
TSTMS ACROSS SRN NORTH DAKOTA AND CNTRL SOUTH DAKOTA. THE
ENVIRONMENT ACROSS THIS AREA IS CHARACTERIZED BY MUCAPE AOA 1000
J/KG AND EFFECTIVE BULK SHEAR AOA 30 KTS WHICH IS SUPPORTIVE OF
SUPERCELLS. ADDITIONALLY...STRONG/SVR TSTMS TO THE SW /ACROSS WW172/
MAY EVENTUALLY MOVE INTO THIS AREA. AS SUCH A WW MAY BECOME
NECESSARY LATER THIS AFTERNOON...WITH LARGE HAIL AND ISOLATED
DAMAGING WIND GUSTS AS THE PRIMARY THREATS.

..MARSH/CORFIDI.. 05/18/2013

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

LAT...LON   45010111 45920200 45960400 47060397 47530331 47760217
            47730086 47629934 46869818 45949798 44659868 43749966
            43910108 45010111

000
ACUS11 KWNS 182225
SWOMCD
SPC MCD 182224
NDZ000-SDZ000-182330-

MESOSCALE DISCUSSION 0679
NWS STORM PREDICTION CENTER NORMAN OK
0524 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SRN NORTH DAKOTA...CNTRL AND NORTH CNTRL SOUTH
DAKOTA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 182224Z - 182330Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...TSTMS ARE EXPECTED TO CONTINUE TO DEVELOP THROUGH THE
AFTERNOON AND INTO THE EVENING ACROSS SRN NORTH DAKOTA...SWD INTO
CNTRL SOUTH DAKOTA. LARGE HAIL AND ISOLATED DAMAGING WIND GUSTS WILL
BE POSSIBLE WITH THE STRONGER STORMS. A WW MAY BECOME NECESSARY
LATER THIS AFTERNOON OR EVENING.

DISCUSSION...BROAD ASCENT IS OVERSPREADING PORTIONS OF THE NRN HIGH
PLAINS IN CONJUNCTION WITH A SUBTLE SHORT-WAVE TROUGH EJECTING NNE
TO THE EAST OF A LARGER-SCALE CYCLONE ACROSS THE WRN CONUS. THIS
ASCENT SHOULD ACT TO WEAKEN CINH ALLOWING FOR THE DEVELOPMENT OF
TSTMS ACROSS SRN NORTH DAKOTA AND CNTRL SOUTH DAKOTA. THE
ENVIRONMENT ACROSS THIS AREA IS CHARACTERIZED BY MUCAPE AOA 1000
J/KG AND EFFECTIVE BULK SHEAR AOA 30 KTS WHICH IS SUPPORTIVE OF
SUPERCELLS. ADDITIONALLY...STRONG/SVR TSTMS TO THE SW /ACROSS WW172/
MAY EVENTUALLY MOVE INTO THIS AREA. AS SUCH A WW MAY BECOME
NECESSARY LATER THIS AFTERNOON...WITH LARGE HAIL AND ISOLATED
DAMAGING WIND GUSTS AS THE PRIMARY THREATS.

..MARSH/CORFIDI.. 05/18/2013

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

LAT...LON   45010111 45920200 45960400 47060397 47530331 47760217
            47730086 47629934 46869818 45949798 44659868 43749966
            43910108 45010111

000
ACUS11 KWNS 182216
SWOMCD
SPC MCD 182215
KSZ000-NEZ000-COZ000-182315-

MESOSCALE DISCUSSION 0678
NWS STORM PREDICTION CENTER NORMAN OK
0515 PM CDT SAT MAY 18 2013

AREAS AFFECTED...PARTS OF NERN CO / WRN-SWRN NE / PORTIONS OF WRN KS

CONCERNING...TORNADO WATCH 170...

VALID 182215Z - 182315Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 170 CONTINUES.

SUMMARY...A LARGE TO VERY LARGE HAIL THREAT WILL PREDOMINATE OVER
THE NEXT 1-2 HOURS FROM WRN NE S AND SEWD INTO PORTIONS OF WRN KS.
THE TORNADO THREAT WILL SEEMINGLY INCREASE AROUND 00Z AND
THEREAFTER.

DISCUSSION...SUBJECTIVE SURFACE MESOANALYSIS PLACES A DRYLINE FROM
THE NE PANHANDLE AND ARCING SEWD TO A DRYLINE BULGE OVER SWRN KS
NEAR DDC.  FAIRLY SUBSTANTIAL BOUNDARY LAYER MIXING ALONG AND IN
AREAS ADJACENTLY E OF THE DRYLINE OVER WRN KS INTO WRN NEB FEATURES
DEWPOINTS IN THE UPPER 50S TO LOWER 60S --CONTRIBUTING TO SIZABLE
SURFACE TEMP/DEWPOINT SPREADS 20-30 DEG F.  UNTIL THESE SPREADS AND
LCL/S BEGIN TO DECREASE EARLY THIS EVENING AND LOW LEVEL SHEAR
STRENGTHENS...LARGE TO VERY LARGE HAIL AND ISOLD DMGG WINDS WILL BE
THE MAIN THREATS.

AS OF 2215Z...WDSS-II SHOWS THE MOST INTENSE SUPERCELLS OVER
NESS/TREGO COUNTIES IN KS.  AS THIS SUPERCELL CLUSTER SLOWLY MOVES
TO THE N...VERY LARGE HAIL WILL LIKELY IMPACT THIS IMMEDIATE
VICINITY OVER THE NEXT HOUR OR TWO.

..SMITH.. 05/18/2013

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

ATTN...WFO...GID...LBF...DDC...GLD...BOU...CYS...

LAT...LON   37109963 38370021 39280262 40240346 42660320 42240080
            40330221 39199944 37449915 37109963

000
ACUS11 KWNS 182216
SWOMCD
SPC MCD 182215
KSZ000-NEZ000-COZ000-182315-

MESOSCALE DISCUSSION 0678
NWS STORM PREDICTION CENTER NORMAN OK
0515 PM CDT SAT MAY 18 2013

AREAS AFFECTED...PARTS OF NERN CO / WRN-SWRN NE / PORTIONS OF WRN KS

CONCERNING...TORNADO WATCH 170...

VALID 182215Z - 182315Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 170 CONTINUES.

SUMMARY...A LARGE TO VERY LARGE HAIL THREAT WILL PREDOMINATE OVER
THE NEXT 1-2 HOURS FROM WRN NE S AND SEWD INTO PORTIONS OF WRN KS.
THE TORNADO THREAT WILL SEEMINGLY INCREASE AROUND 00Z AND
THEREAFTER.

DISCUSSION...SUBJECTIVE SURFACE MESOANALYSIS PLACES A DRYLINE FROM
THE NE PANHANDLE AND ARCING SEWD TO A DRYLINE BULGE OVER SWRN KS
NEAR DDC.  FAIRLY SUBSTANTIAL BOUNDARY LAYER MIXING ALONG AND IN
AREAS ADJACENTLY E OF THE DRYLINE OVER WRN KS INTO WRN NEB FEATURES
DEWPOINTS IN THE UPPER 50S TO LOWER 60S --CONTRIBUTING TO SIZABLE
SURFACE TEMP/DEWPOINT SPREADS 20-30 DEG F.  UNTIL THESE SPREADS AND
LCL/S BEGIN TO DECREASE EARLY THIS EVENING AND LOW LEVEL SHEAR
STRENGTHENS...LARGE TO VERY LARGE HAIL AND ISOLD DMGG WINDS WILL BE
THE MAIN THREATS.

AS OF 2215Z...WDSS-II SHOWS THE MOST INTENSE SUPERCELLS OVER
NESS/TREGO COUNTIES IN KS.  AS THIS SUPERCELL CLUSTER SLOWLY MOVES
TO THE N...VERY LARGE HAIL WILL LIKELY IMPACT THIS IMMEDIATE
VICINITY OVER THE NEXT HOUR OR TWO.

..SMITH.. 05/18/2013

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

ATTN...WFO...GID...LBF...DDC...GLD...BOU...CYS...

LAT...LON   37109963 38370021 39280262 40240346 42660320 42240080
            40330221 39199944 37449915 37109963

000
ACUS11 KWNS 182031
SWOMCD
SPC MCD 182031
SDZ000-MTZ000-WYZ000-182130-

MESOSCALE DISCUSSION 0677
NWS STORM PREDICTION CENTER NORMAN OK
0331 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN/CNTRL SD...NERN WY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 182031Z - 182130Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTM COVERAGE IS EXPECTED TO INCREASE IN COVERAGE THROUGH
THE REMAINDER OF THE AFTERNOON...WITH A PRIMARY THREAT OF LARGE HAIL
AND DAMAGING WINDS. AREA IS BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...SLOW-MOVING SUPERCELL THUNDERSTORMS HAVE BEEN ONGOING
FOR THE LAST 1-2 HOURS ACROSS THE BLACK HILLS...WITH MODERATE MLCAPE
OF 1000-2000 J/KG AND EFFECTIVE SHEAR OF 35-45 KTS SUPPORTING A
LARGE HAIL RISK. ADDITIONAL ATTEMPTS AT INITIATION ARE UNDERWAY
NORTH OF THE ONGOING SUPERCELLS...AND ALSO FURTHER EAST NEAR PIR
ALONG A DIFFUSE SLOW-MOVING WARM FRONT. MULTIPLE EMBEDDED VORTICITY
MAXIMA WITHIN BROAD SWLY MIDLEVEL FLOW WILL CONTINUE TO SUPPORT TSTM
DEVELOPMENT...WITH SUFFICIENT INSTABILITY/SHEAR FOR ORGANIZED STORM
STRUCTURES.

SPLITTING SUPERCELLS WILL BE THE PRIMARY MODE FOR THE NEXT 2-3
HOURS...WITH A THREAT OF LARGE HAIL AND PERHAPS AN ISOLATED
TORNADO...ESPECIALLY WITH ANY STORMS INTERACTING WITH THE WARM
FRONT. UPSCALE GROWTH INTO ONE OR MORE CLUSTERS IS POSSIBLE EARLY
THIS EVENING...WHICH WOULD LEAD TO INCREASE IN SEVERE WIND RISK. IF
THE UPWARD TREND IN TSTM COVERAGE CONTINUES...WW ISSUANCE WILL BE
POSSIBLE.

..DEAN/KERR.. 05/18/2013

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

ATTN...WFO...FSD...ABR...UNR...CYS...BYZ...

LAT...LON   43490430 44130510 45020508 45630337 45730190 45590035
            45139934 44469890 43909877 43549887 43369958 43100010
            43040042 43050199 43010293 43030356 43070388 43330414
            43490430

000
ACUS11 KWNS 182031
SWOMCD
SPC MCD 182031
SDZ000-MTZ000-WYZ000-182130-

MESOSCALE DISCUSSION 0677
NWS STORM PREDICTION CENTER NORMAN OK
0331 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN/CNTRL SD...NERN WY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 182031Z - 182130Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTM COVERAGE IS EXPECTED TO INCREASE IN COVERAGE THROUGH
THE REMAINDER OF THE AFTERNOON...WITH A PRIMARY THREAT OF LARGE HAIL
AND DAMAGING WINDS. AREA IS BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...SLOW-MOVING SUPERCELL THUNDERSTORMS HAVE BEEN ONGOING
FOR THE LAST 1-2 HOURS ACROSS THE BLACK HILLS...WITH MODERATE MLCAPE
OF 1000-2000 J/KG AND EFFECTIVE SHEAR OF 35-45 KTS SUPPORTING A
LARGE HAIL RISK. ADDITIONAL ATTEMPTS AT INITIATION ARE UNDERWAY
NORTH OF THE ONGOING SUPERCELLS...AND ALSO FURTHER EAST NEAR PIR
ALONG A DIFFUSE SLOW-MOVING WARM FRONT. MULTIPLE EMBEDDED VORTICITY
MAXIMA WITHIN BROAD SWLY MIDLEVEL FLOW WILL CONTINUE TO SUPPORT TSTM
DEVELOPMENT...WITH SUFFICIENT INSTABILITY/SHEAR FOR ORGANIZED STORM
STRUCTURES.

SPLITTING SUPERCELLS WILL BE THE PRIMARY MODE FOR THE NEXT 2-3
HOURS...WITH A THREAT OF LARGE HAIL AND PERHAPS AN ISOLATED
TORNADO...ESPECIALLY WITH ANY STORMS INTERACTING WITH THE WARM
FRONT. UPSCALE GROWTH INTO ONE OR MORE CLUSTERS IS POSSIBLE EARLY
THIS EVENING...WHICH WOULD LEAD TO INCREASE IN SEVERE WIND RISK. IF
THE UPWARD TREND IN TSTM COVERAGE CONTINUES...WW ISSUANCE WILL BE
POSSIBLE.

..DEAN/KERR.. 05/18/2013

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

ATTN...WFO...FSD...ABR...UNR...CYS...BYZ...

LAT...LON   43490430 44130510 45020508 45630337 45730190 45590035
            45139934 44469890 43909877 43549887 43369958 43100010
            43040042 43050199 43010293 43030356 43070388 43330414
            43490430

000
ACUS11 KWNS 182031
SWOMCD
SPC MCD 182031
SDZ000-MTZ000-WYZ000-182130-

MESOSCALE DISCUSSION 0677
NWS STORM PREDICTION CENTER NORMAN OK
0331 PM CDT SAT MAY 18 2013

AREAS AFFECTED...WRN/CNTRL SD...NERN WY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 182031Z - 182130Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...TSTM COVERAGE IS EXPECTED TO INCREASE IN COVERAGE THROUGH
THE REMAINDER OF THE AFTERNOON...WITH A PRIMARY THREAT OF LARGE HAIL
AND DAMAGING WINDS. AREA IS BEING MONITORED FOR A POSSIBLE WW.

DISCUSSION...SLOW-MOVING SUPERCELL THUNDERSTORMS HAVE BEEN ONGOING
FOR THE LAST 1-2 HOURS ACROSS THE BLACK HILLS...WITH MODERATE MLCAPE
OF 1000-2000 J/KG AND EFFECTIVE SHEAR OF 35-45 KTS SUPPORTING A
LARGE HAIL RISK. ADDITIONAL ATTEMPTS AT INITIATION ARE UNDERWAY
NORTH OF THE ONGOING SUPERCELLS...AND ALSO FURTHER EAST NEAR PIR
ALONG A DIFFUSE SLOW-MOVING WARM FRONT. MULTIPLE EMBEDDED VORTICITY
MAXIMA WITHIN BROAD SWLY MIDLEVEL FLOW WILL CONTINUE TO SUPPORT TSTM
DEVELOPMENT...WITH SUFFICIENT INSTABILITY/SHEAR FOR ORGANIZED STORM
STRUCTURES.

SPLITTING SUPERCELLS WILL BE THE PRIMARY MODE FOR THE NEXT 2-3
HOURS...WITH A THREAT OF LARGE HAIL AND PERHAPS AN ISOLATED
TORNADO...ESPECIALLY WITH ANY STORMS INTERACTING WITH THE WARM
FRONT. UPSCALE GROWTH INTO ONE OR MORE CLUSTERS IS POSSIBLE EARLY
THIS EVENING...WHICH WOULD LEAD TO INCREASE IN SEVERE WIND RISK. IF
THE UPWARD TREND IN TSTM COVERAGE CONTINUES...WW ISSUANCE WILL BE
POSSIBLE.

..DEAN/KERR.. 05/18/2013

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

ATTN...WFO...FSD...ABR...UNR...CYS...BYZ...

LAT...LON   43490430 44130510 45020508 45630337 45730190 45590035
            45139934 44469890 43909877 43549887 43369958 43100010
            43040042 43050199 43010293 43030356 43070388 43330414
            43490430

000
ACUS01 KWNS 181941
SWODY1
SPC AC 181938

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0238 PM CDT SAT MAY 18 2013

VALID 182000Z - 191200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM NWRN OK INTO SWRN NEB...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
WEST TX INTO SERN ND/WRN MN...

EARLIER THOUGHTS REGARDING CONVECTIVE EVOLUTION REMAIN.  AS A
RESULT...ONLY MINOR MODIFICATIONS HAVE BEEN MADE TO 1630Z SEVERE
THREAT ALONG THE DRYLINE.

STRONG HEATING ACROSS THE HIGH PLAINS FROM THE TX PANHANDLE INTO
SWRN KS HAVE FORCED SFC TEMPERATURES TO NEAR/ABOVE 100F.  AS A
RESULT...CAP HAS BEEN REMOVED AND BOUNDARY LAYER CU ARE DEEPENING
MARKEDLY ALONG LEADING EDGE OF STEEP LAPSE RATE PLUME ACROSS SWRN
KS.  IT APPEARS TSTMS WILL EVOLVE OVER THE NEXT FEW HOURS ACROSS
THIS REGION.

HAVE OPTED TO EXTEND THE MDT RISK A BIT NORTH ACROSS NEB TO ACCOUNT
FOR SCT-NUMEROUS TSTMS THAT SHOULD EVOLVE ALONG WRN FRINGE OF HIGHER
MOISTURE/INSTABILITY.  WEAK CONVERGENCE AXIS EXTENDS FROM JUST EAST
OF GLD INTO CHERRY COUNTY NEB AND THIS SHOULD FOCUS SEVERE TSTMS BY
MID-LATE AFTERNOON.

HAVE MADE A SWD ADJUSTMENT TO CATEGORICAL SLGT RISK ALONG THE
DRYLINE OVER SWRN TX TO ACCOUNT FOR EXPECTED SEVERE DEVELOPMENT AT
THIS LATITUDE.  ALTHOUGH ACTIVITY SHOULD BE ISOLATED...IT APPEARS
SUFFICIENT FLOW ALOFT WILL SUPPORT DEEP ROTATING UPDRAFTS.

..DARROW.. 05/18/2013

.PREV DISCUSSION... /ISSUED 1127 AM CDT SAT MAY 18 2013/

...SYNOPSIS...
IN ADVANCE OF THE UPPER TROUGH OVER THE INTERMOUNTAIN WEST...WARM
ELEVATED MIXED LAYER AIR HAS OVERSPREAD MOST OF THE PLAINS AND LOWER
MISSISSIPPI VALLEY.  THIS IS WHERE THE BOUNDARY LAYER CONTINUES TO
MOISTEN DUE TO BOTH EVAPOTRANSPIRATION AND A RETURN FLOW OF MOISTURE
OFF GULF OF MEXICO.  VEERED LOW-LEVEL FLOW /AT 850 MB/ TO A
SUBSTANTIAL WESTERLY COMPONENT APPEARS TO BE CUTTING OFF THE GULF
RETURN FLOW TO THE CENTRAL/NORTHERN PLAINS...THOUGH...AT LEAST
TEMPORARILY.  BUT THIS MAY BEGIN TO CHANGE BY THIS EVENING...AS
LOW-LEVEL FLOW BACKS TO A MORE PROMINENT SOUTHERLY COMPONENT...AND
STRENGTHENS...IN ASSOCIATION WITH DEEPENING AND CONSOLIDATION OF A
SURFACE LOW OVER THE CENTRAL PLAINS...AS MID-LEVEL HEIGHT FALLS
INCREASE TO THE EAST OF THE ROCKIES.

MODEST STRENGTHENING OF CYCLONIC MID/UPPER FLOW IS EXPECTED ACROSS
THE PLAINS TODAY...AS SEVERAL SMALLER SCALE IMPULSES BEGIN TO EMERGE
FROM THE INTERMOUNTAIN WEST.  STRONGEST FLOW ALOFT...HOWEVER...WILL
PERSIST IN A BELT ACROSS THE NORTH CENTRAL PACIFIC COAST INTO THE
SOUTHERN ROCKIES...BUT COULD BEGIN TO NOSE EASTWARD ACROSS THE TEXAS
PANHANDLE REGION TOWARD THE END OF THE FORECAST PERIOD.
STILL...GIVEN THE THERMODYNAMIC PROFILES EVOLVING ACROSS MUCH OF THE
PLAINS...WHICH WILL INCLUDE AREAS OF STRONG TO EXTREME CAPE...A RISK
FOR SEVERE THUNDERSTORMS WILL EXIST ACROSS A FAIRLY BROAD AREA.
ORGANIZED CLUSTERS OF STORMS APPEAR POSSIBLE...IN ADDITION TO THE
RISK FOR DISCRETE SUPERCELLS ...THE STRONGEST OF WHICH MAY BECOME
CAPABLE OF PRODUCING VERY LARGE HAIL AND A COUPLE OF TORNADOES.

ALTHOUGH SEVERE PROBABILITIES STILL SEEM  A BIT LOWER THAN THE
PLAINS...OTHER STRONG/ISOLATED SEVERE STORM DEVELOPMENT MAY ALSO
OCCUR TODAY EAST OF THE LOWER MISSISSIPPI VALLEY INTO PARTS OF THE
EASTERN GULF STATES.  THIS IS WHERE LOWER/MID TROPOSPHERIC WARM
ADVECTION ON THE EASTWARD ADVANCING EDGE OF WARMER ELEVATED MIXED
LAYER AIR...IN THE WAKE OF A WEAKENING UPPER IMPULSE ADVANCING
TOWARD THE SOUTH ATLANTIC COAST...MAY CONTRIBUTE TO INCREASING LIFT
AND STEEPENING MID-LEVEL LAPSE RATES.

...CENTRAL PLAINS...
AN INITIAL IMPULSE...NOW LIFTING NORTHEAST OF THE PANHANDLE REGION
INTO THE CENTRAL PLAINS...IS CONTRIBUTING TO SOME UNCERTAINTY
CONCERNING DRYLINE POSITION AND CONVECTIVE POTENTIAL LATER THIS
AFTERNOON...MAINLY SOUTH OF THE KANSAS/OKLAHOMA BORDER.
HOWEVER...THE DRYLINE IS STILL EXPECTED TO BE THE MAIN FOCUS FOR
STRONGEST DESTABILIZATION AND STORM DEVELOPMENT LATER THIS
AFTERNOON.  AIDED BY FORCING ASSOCIATED WITH CONTINUING MID-LEVEL
HEIGHT FALLS...SUBSTANTIAL MID-LEVEL INHIBITION IS EXPECTED TO
WEAKEN SUFFICIENTLY FOR THE INITIATION OF DISCRETE SUPERCELLS ACROSS
SOUTHWESTERN NEBRASKA INTO WESTERN KANSAS DURING THE 21-00Z TIME
FRAME...PERHAPS SOUTHWARD ACROSS WESTERN OKLAHOMA INTO NORTHWEST
TEXAS AS WELL.

VERY LARGE HAIL MAY BE THE PRIMARY SEVERE THREAT...INITIALLY... BUT
LOW-LEVEL LAPSE RATES PROBABLY WILL BE SUFFICIENTLY STEEP TO SUPPORT
A RISK FOR TORNADOES BENEATH INCREASINGLY CYCLONIC AND DIFLUENT
HIGH-LEVEL FLOW.  AS THE 850 MB JET BECOMES MORE SOUTHERLY AND
STRENGTHENS TO 40-50+ KT LATER THIS EVENING...A WINDOW OF
OPPORTUNITY WILL EXIST FOR INCREASING TORNADIC POTENTIAL...INCLUDING
THE RISK FOR ONE OR TWO STRONG TORNADOES.  THIS POTENTIAL APPEARS TO
HINGE LARGELY ON HOW LONG IT TAKES FOR CONVECTION TO GROW UPSCALE
INTO ORGANIZING MESOSCALE CONVECTIVE SYSTEMS...WITH DAMAGING
STRAIGHT LINE WINDS BECOMING A MORE PROMINENT THREAT.  THIS REMAINS
UNCERTAIN...BUT IT APPEARS THAT UPSCALE GROWTH COULD OCCUR FAIRLY
QUICKLY.

000
ACUS01 KWNS 181941
SWODY1
SPC AC 181938

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0238 PM CDT SAT MAY 18 2013

VALID 182000Z - 191200Z

...THERE IS A MDT RISK OF SVR TSTMS FROM NWRN OK INTO SWRN NEB...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
WEST TX INTO SERN ND/WRN MN...

EARLIER THOUGHTS REGARDING CONVECTIVE EVOLUTION REMAIN.  AS A
RESULT...ONLY MINOR MODIFICATIONS HAVE BEEN MADE TO 1630Z SEVERE
THREAT ALONG THE DRYLINE.

STRONG HEATING ACROSS THE HIGH PLAINS FROM THE TX PANHANDLE INTO
SWRN KS HAVE FORCED SFC TEMPERATURES TO NEAR/ABOVE 100F.  AS A
RESULT...CAP HAS BEEN REMOVED AND BOUNDARY LAYER CU ARE DEEPENING
MARKEDLY ALONG LEADING EDGE OF STEEP LAPSE RATE PLUME ACROSS SWRN
KS.  IT APPEARS TSTMS WILL EVOLVE OVER THE NEXT FEW HOURS ACROSS
THIS REGION.

HAVE OPTED TO EXTEND THE MDT RISK A BIT NORTH ACROSS NEB TO ACCOUNT
FOR SCT-NUMEROUS TSTMS THAT SHOULD EVOLVE ALONG WRN FRINGE OF HIGHER
MOISTURE/INSTABILITY.  WEAK CONVERGENCE AXIS EXTENDS FROM JUST EAST
OF GLD INTO CHERRY COUNTY NEB AND THIS SHOULD FOCUS SEVERE TSTMS BY
MID-LATE AFTERNOON.

HAVE MADE A SWD ADJUSTMENT TO CATEGORICAL SLGT RISK ALONG THE
DRYLINE OVER SWRN TX TO ACCOUNT FOR EXPECTED SEVERE DEVELOPMENT AT
THIS LATITUDE.  ALTHOUGH ACTIVITY SHOULD BE ISOLATED...IT APPEARS
SUFFICIENT FLOW ALOFT WILL SUPPORT DEEP ROTATING UPDRAFTS.

..DARROW.. 05/18/2013

.PREV DISCUSSION... /ISSUED 1127 AM CDT SAT MAY 18 2013/

...SYNOPSIS...
IN ADVANCE OF THE UPPER TROUGH OVER THE INTERMOUNTAIN WEST...WARM
ELEVATED MIXED LAYER AIR HAS OVERSPREAD MOST OF THE PLAINS AND LOWER
MISSISSIPPI VALLEY.  THIS IS WHERE THE BOUNDARY LAYER CONTINUES TO
MOISTEN DUE TO BOTH EVAPOTRANSPIRATION AND A RETURN FLOW OF MOISTURE
OFF GULF OF MEXICO.  VEERED LOW-LEVEL FLOW /AT 850 MB/ TO A
SUBSTANTIAL WESTERLY COMPONENT APPEARS TO BE CUTTING OFF THE GULF
RETURN FLOW TO THE CENTRAL/NORTHERN PLAINS...THOUGH...AT LEAST
TEMPORARILY.  BUT THIS MAY BEGIN TO CHANGE BY THIS EVENING...AS
LOW-LEVEL FLOW BACKS TO A MORE PROMINENT SOUTHERLY COMPONENT...AND
STRENGTHENS...IN ASSOCIATION WITH DEEPENING AND CONSOLIDATION OF A
SURFACE LOW OVER THE CENTRAL PLAINS...AS MID-LEVEL HEIGHT FALLS
INCREASE TO THE EAST OF THE ROCKIES.

MODEST STRENGTHENING OF CYCLONIC MID/UPPER FLOW IS EXPECTED ACROSS
THE PLAINS TODAY...AS SEVERAL SMALLER SCALE IMPULSES BEGIN TO EMERGE
FROM THE INTERMOUNTAIN WEST.  STRONGEST FLOW ALOFT...HOWEVER...WILL
PERSIST IN A BELT ACROSS THE NORTH CENTRAL PACIFIC COAST INTO THE
SOUTHERN ROCKIES...BUT COULD BEGIN TO NOSE EASTWARD ACROSS THE TEXAS
PANHANDLE REGION TOWARD THE END OF THE FORECAST PERIOD.
STILL...GIVEN THE THERMODYNAMIC PROFILES EVOLVING ACROSS MUCH OF THE
PLAINS...WHICH WILL INCLUDE AREAS OF STRONG TO EXTREME CAPE...A RISK
FOR SEVERE THUNDERSTORMS WILL EXIST ACROSS A FAIRLY BROAD AREA.
ORGANIZED CLUSTERS OF STORMS APPEAR POSSIBLE...IN ADDITION TO THE
RISK FOR DISCRETE SUPERCELLS ...THE STRONGEST OF WHICH MAY BECOME
CAPABLE OF PRODUCING VERY LARGE HAIL AND A COUPLE OF TORNADOES.

ALTHOUGH SEVERE PROBABILITIES STILL SEEM  A BIT LOWER THAN THE
PLAINS...OTHER STRONG/ISOLATED SEVERE STORM DEVELOPMENT MAY ALSO
OCCUR TODAY EAST OF THE LOWER MISSISSIPPI VALLEY INTO PARTS OF THE
EASTERN GULF STATES.  THIS IS WHERE LOWER/MID TROPOSPHERIC WARM
ADVECTION ON THE EASTWARD ADVANCING EDGE OF WARMER ELEVATED MIXED
LAYER AIR...IN THE WAKE OF A WEAKENING UPPER IMPULSE ADVANCING
TOWARD THE SOUTH ATLANTIC COAST...MAY CONTRIBUTE TO INCREASING LIFT
AND STEEPENING MID-LEVEL LAPSE RATES.

...CENTRAL PLAINS...
AN INITIAL IMPULSE...NOW LIFTING NORTHEAST OF THE PANHANDLE REGION
INTO THE CENTRAL PLAINS...IS CONTRIBUTING TO SOME UNCERTAINTY
CONCERNING DRYLINE POSITION AND CONVECTIVE POTENTIAL LATER THIS
AFTERNOON...MAINLY SOUTH OF THE KANSAS/OKLAHOMA BORDER.
HOWEVER...THE DRYLINE IS STILL EXPECTED TO BE THE MAIN FOCUS FOR
STRONGEST DESTABILIZATION AND STORM DEVELOPMENT LATER THIS
AFTERNOON.  AIDED BY FORCING ASSOCIATED WITH CONTINUING MID-LEVEL
HEIGHT FALLS...SUBSTANTIAL MID-LEVEL INHIBITION IS EXPECTED TO
WEAKEN SUFFICIENTLY FOR THE INITIATION OF DISCRETE SUPERCELLS ACROSS
SOUTHWESTERN NEBRASKA INTO WESTERN KANSAS DURING THE 21-00Z TIME
FRAME...PERHAPS SOUTHWARD ACROSS WESTERN OKLAHOMA INTO NORTHWEST
TEXAS AS WELL.

VERY LARGE HAIL MAY BE THE PRIMARY SEVERE THREAT...INITIALLY... BUT
LOW-LEVEL LAPSE RATES PROBABLY WILL BE SUFFICIENTLY STEEP TO SUPPORT
A RISK FOR TORNADOES BENEATH INCREASINGLY CYCLONIC AND DIFLUENT
HIGH-LEVEL FLOW.  AS THE 850 MB JET BECOMES MORE SOUTHERLY AND
STRENGTHENS TO 40-50+ KT LATER THIS EVENING...A WINDOW OF
OPPORTUNITY WILL EXIST FOR INCREASING TORNADIC POTENTIAL...INCLUDING
THE RISK FOR ONE OR TWO STRONG TORNADOES.  THIS POTENTIAL APPEARS TO
HINGE LARGELY ON HOW LONG IT TAKES FOR CONVECTION TO GROW UPSCALE
INTO ORGANIZING MESOSCALE CONVECTIVE SYSTEMS...WITH DAMAGING
STRAIGHT LINE WINDS BECOMING A MORE PROMINENT THREAT.  THIS REMAINS
UNCERTAIN...BUT IT APPEARS THAT UPSCALE GROWTH COULD OCCUR FAIRLY
QUICKLY.

000
ACUS11 KWNS 181920
SWOMCD
SPC MCD 181919
OKZ000-KSZ000-TXZ000-182015-

MESOSCALE DISCUSSION 0676
NWS STORM PREDICTION CENTER NORMAN OK
0219 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SWRN KS...WRN OK...NW TX...FAR ERN OK/TX PANHANDLES

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 181919Z - 182015Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SCATTERED TSTM INITIATION IS EXPECTED ON THE DRYLINE BY
21-22Z. VERY LARGE HAIL...ISOLATED TORNADOES...AND DAMAGING WIND
WILL BE POSSIBLE. WATCH ISSUANCE IS EXPECTED IN THE NEXT HOUR OR SO.

DISCUSSION...LATEST SFC ANALYSIS DEPICTS THE DRYLINE EXTENDING FROM
SWRN KS INTO THE FAR ERN OK/TX PANHANDLES AND NW TX. VIS IMAGERY
SHOWS CU INCREASING IN THE WELL-MIXED AIRMASS IN THE VICINITY OF THE
DRYLINE ACROSS SW KS INTO THE TX PANHANDLE. WHILE ONE EMBEDDED VORT
MAX IS MOVING NWD OUT OF THE AREA...ANOTHER EMBEDDED VORT MAX OVER
SERN CO/NERN NM SHOULD AID IN CONVECTIVE INITIATION LATER THIS
AFTERNOON.

THE 18Z DDC SOUNDING SHOWS VERY STEEP LAPSE RATES IN EXCESS OF 9.5
C/KM IN THE 750-500 MB LAYER...WHICH WILL SUPPORT VERY HIGH TO
EXTREME MLCAPE OF 3000-4000 J/KG IN AREAS AHEAD OF THE DRYLINE THIS
AFTERNOON AND EARLY EVENING. WHILE FLOW IS RELATIVELY
MODEST...INCREASING SWLY MIDLEVEL FLOW IS SUPPORTING EFFECTIVE SHEAR
OF 35-45 KTS AHEAD OF THE DRYLINE...WHICH WILL BE MORE THAN
SUFFICIENT FOR SUPERCELL DEVELOPMENT UPON STORM INITIATION.

DISCRETE SUPERCELL ACTIVITY IS EXPECTED WITHIN THE FIRST 2-3 HOURS
OF INITIATION...WITH VERY LARGE HAIL IN EXCESS OF BASEBALL SIZE THE
PRIMARY THREAT. LARGE T/TD SPREADS AND RELATIVELY WEAK LOW-LEVEL
SHEAR WILL LIMIT THE TORNADO THREAT INITIALLY...BUT A MARKED
INCREASE IN THE LOW-LEVEL JET WILL INCREASE THE TORNADO THREAT
TOWARD EVENING ACROSS MAINLY NWRN OK INTO SWRN KS...WITH ISOLATED
STRONG TORNADOES POSSIBLE WITH ANY STORMS THAT CAN REMAIN DISCRETE
AFTER 00Z. HOWEVER...STORM CONSOLIDATION IN A WELL-MIXED ENVIRONMENT
MAY RESULT IN UPSCALE GROWTH AND A TRANSITION TO MORE OF A SEVERE
WIND THREAT THIS EVENING...POSSIBLY LIMITING THE WINDOW OF
OPPORTUNITY FOR A MORE ROBUST TORNADO THREAT.

..DEAN/KERR.. 05/18/2013

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

ATTN...WFO...ICT...FWD...OUN...DDC...SJT...GLD...LUB...AMA...

LAT...LON   37290112 37880150 38500134 38920033 38829937 38509866
            38129815 37669781 36889765 35559772 34699766 33459786
            32919805 32419816 32199830 31989879 31989936 32069993
            32170043 32790063 33780057 35300063 36140066 37290112

000
ACUS11 KWNS 181920
SWOMCD
SPC MCD 181919
OKZ000-KSZ000-TXZ000-182015-

MESOSCALE DISCUSSION 0676
NWS STORM PREDICTION CENTER NORMAN OK
0219 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SWRN KS...WRN OK...NW TX...FAR ERN OK/TX PANHANDLES

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 181919Z - 182015Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SCATTERED TSTM INITIATION IS EXPECTED ON THE DRYLINE BY
21-22Z. VERY LARGE HAIL...ISOLATED TORNADOES...AND DAMAGING WIND
WILL BE POSSIBLE. WATCH ISSUANCE IS EXPECTED IN THE NEXT HOUR OR SO.

DISCUSSION...LATEST SFC ANALYSIS DEPICTS THE DRYLINE EXTENDING FROM
SWRN KS INTO THE FAR ERN OK/TX PANHANDLES AND NW TX. VIS IMAGERY
SHOWS CU INCREASING IN THE WELL-MIXED AIRMASS IN THE VICINITY OF THE
DRYLINE ACROSS SW KS INTO THE TX PANHANDLE. WHILE ONE EMBEDDED VORT
MAX IS MOVING NWD OUT OF THE AREA...ANOTHER EMBEDDED VORT MAX OVER
SERN CO/NERN NM SHOULD AID IN CONVECTIVE INITIATION LATER THIS
AFTERNOON.

THE 18Z DDC SOUNDING SHOWS VERY STEEP LAPSE RATES IN EXCESS OF 9.5
C/KM IN THE 750-500 MB LAYER...WHICH WILL SUPPORT VERY HIGH TO
EXTREME MLCAPE OF 3000-4000 J/KG IN AREAS AHEAD OF THE DRYLINE THIS
AFTERNOON AND EARLY EVENING. WHILE FLOW IS RELATIVELY
MODEST...INCREASING SWLY MIDLEVEL FLOW IS SUPPORTING EFFECTIVE SHEAR
OF 35-45 KTS AHEAD OF THE DRYLINE...WHICH WILL BE MORE THAN
SUFFICIENT FOR SUPERCELL DEVELOPMENT UPON STORM INITIATION.

DISCRETE SUPERCELL ACTIVITY IS EXPECTED WITHIN THE FIRST 2-3 HOURS
OF INITIATION...WITH VERY LARGE HAIL IN EXCESS OF BASEBALL SIZE THE
PRIMARY THREAT. LARGE T/TD SPREADS AND RELATIVELY WEAK LOW-LEVEL
SHEAR WILL LIMIT THE TORNADO THREAT INITIALLY...BUT A MARKED
INCREASE IN THE LOW-LEVEL JET WILL INCREASE THE TORNADO THREAT
TOWARD EVENING ACROSS MAINLY NWRN OK INTO SWRN KS...WITH ISOLATED
STRONG TORNADOES POSSIBLE WITH ANY STORMS THAT CAN REMAIN DISCRETE
AFTER 00Z. HOWEVER...STORM CONSOLIDATION IN A WELL-MIXED ENVIRONMENT
MAY RESULT IN UPSCALE GROWTH AND A TRANSITION TO MORE OF A SEVERE
WIND THREAT THIS EVENING...POSSIBLY LIMITING THE WINDOW OF
OPPORTUNITY FOR A MORE ROBUST TORNADO THREAT.

..DEAN/KERR.. 05/18/2013

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

ATTN...WFO...ICT...FWD...OUN...DDC...SJT...GLD...LUB...AMA...

LAT...LON   37290112 37880150 38500134 38920033 38829937 38509866
            38129815 37669781 36889765 35559772 34699766 33459786
            32919805 32419816 32199830 31989879 31989936 32069993
            32170043 32790063 33780057 35300063 36140066 37290112

000
ACUS11 KWNS 181920
SWOMCD
SPC MCD 181919
OKZ000-KSZ000-TXZ000-182015-

MESOSCALE DISCUSSION 0676
NWS STORM PREDICTION CENTER NORMAN OK
0219 PM CDT SAT MAY 18 2013

AREAS AFFECTED...SWRN KS...WRN OK...NW TX...FAR ERN OK/TX PANHANDLES

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 181919Z - 182015Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SCATTERED TSTM INITIATION IS EXPECTED ON THE DRYLINE BY
21-22Z. VERY LARGE HAIL...ISOLATED TORNADOES...AND DAMAGING WIND
WILL BE POSSIBLE. WATCH ISSUANCE IS EXPECTED IN THE NEXT HOUR OR SO.

DISCUSSION...LATEST SFC ANALYSIS DEPICTS THE DRYLINE EXTENDING FROM
SWRN KS INTO THE FAR ERN OK/TX PANHANDLES AND NW TX. VIS IMAGERY
SHOWS CU INCREASING IN THE WELL-MIXED AIRMASS IN THE VICINITY OF THE
DRYLINE ACROSS SW KS INTO THE TX PANHANDLE. WHILE ONE EMBEDDED VORT
MAX IS MOVING NWD OUT OF THE AREA...ANOTHER EMBEDDED VORT MAX OVER
SERN CO/NERN NM SHOULD AID IN CONVECTIVE INITIATION LATER THIS
AFTERNOON.

THE 18Z DDC SOUNDING SHOWS VERY STEEP LAPSE RATES IN EXCESS OF 9.5
C/KM IN THE 750-500 MB LAYER...WHICH WILL SUPPORT VERY HIGH TO
EXTREME MLCAPE OF 3000-4000 J/KG IN AREAS AHEAD OF THE DRYLINE THIS
AFTERNOON AND EARLY EVENING. WHILE FLOW IS RELATIVELY
MODEST...INCREASING SWLY MIDLEVEL FLOW IS SUPPORTING EFFECTIVE SHEAR
OF 35-45 KTS AHEAD OF THE DRYLINE...WHICH WILL BE MORE THAN
SUFFICIENT FOR SUPERCELL DEVELOPMENT UPON STORM INITIATION.

DISCRETE SUPERCELL ACTIVITY IS EXPECTED WITHIN THE FIRST 2-3 HOURS
OF INITIATION...WITH VERY LARGE HAIL IN EXCESS OF BASEBALL SIZE THE
PRIMARY THREAT. LARGE T/TD SPREADS AND RELATIVELY WEAK LOW-LEVEL
SHEAR WILL LIMIT THE TORNADO THREAT INITIALLY...BUT A MARKED
INCREASE IN THE LOW-LEVEL JET WILL INCREASE THE TORNADO THREAT
TOWARD EVENING ACROSS MAINLY NWRN OK INTO SWRN KS...WITH ISOLATED
STRONG TORNADOES POSSIBLE WITH ANY STORMS THAT CAN REMAIN DISCRETE
AFTER 00Z. HOWEVER...STORM CONSOLIDATION IN A WELL-MIXED ENVIRONMENT
MAY RESULT IN UPSCALE GROWTH AND A TRANSITION TO MORE OF A SEVERE
WIND THREAT THIS EVENING...POSSIBLY LIMITING THE WINDOW OF
OPPORTUNITY FOR A MORE ROBUST TORNADO THREAT.

..DEAN/KERR.. 05/18/2013

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

ATTN...WFO...ICT...FWD...OUN...DDC...SJT...GLD...LUB...AMA...

LAT...LON   37290112 37880150 38500134 38920033 38829937 38509866
            38129815 37669781 36889765 35559772 34699766 33459786
            32919805 32419816 32199830 31989879 31989936 32069993
            32170043 32790063 33780057 35300063 36140066 37290112

000
ACUS11 KWNS 181910
SWOMCD
SPC MCD 181909
KSZ000-NEZ000-COZ000-182045-

MESOSCALE DISCUSSION 0675
NWS STORM PREDICTION CENTER NORMAN OK
0209 PM CDT SAT MAY 18 2013

AREAS AFFECTED...NWRN KS...NERN CO AND WRN NEB

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 181909Z - 182045Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO INITIATE BY 20-21Z FROM NERN CO
INTO NWRN KS AND EXTREME SERN WY...THEN SUBSEQUENTLY DEVELOP NEWD
INTO WRN NEB DURING THE EVENING. PRIMARY THREATS WILL BE VERY LARGE
HAIL AND ISOLATED TORNADOES. STORMS MAY EVENTUALLY GROW UPSCALE INTO
ONE OR MORE CLUSTERS LATER IN THE EVENING WITH AN INCREASING THREAT
FOR DAMAGING WIND. A TORNADO WATCH WILL LIKELY BE NEEDED PRIOR TO
21Z.

DISCUSSION...THIS AFTERNOON A DRYLINE EXTENDS FROM SERN WY TO A
MESOLOW NEAR THE KS/CO BORDER THEN FARTHER SWD THROUGH SWRN KS. THE
LATEST OBJECTIVE ANALYSIS INDICATES THE WARM SECTOR HAS BECOME VERY
UNSTABLE IN CORRIDOR FROM NWRN KS THROUGH EXTREME NERN CO AND WRN
NEB WHERE VERY STEEP LAPSE RATES /APPROACHING 9 C/KM/ HAVE
OVERSPREAD THE MOIST AXIS. SPECIAL 18Z RAOB FROM NORTH PLATTE NEB
INDICATES A STRONG CAPPING INVERSION IS STILL IN PLACE JUST BELOW
700 MB IN ASSOCIATION WITH WARM AIR AT BASE OF THE EML. THIS
SUGGESTS THUNDERSTORM INITIATION WILL LIKELY BE FARTHER WEST ACROSS
NERN CO AND NWRN KS. SATELLITE IMAGERY SHOWS MID-LEVEL CONVECTION
SPREADING RAPIDLY NWD ACROSS NERN CO AND NWRN KS AND APPEARS TO BE
IN ASSOCIATION WITH MID-LEVEL ASCENT ACCOMPANYING A NEWD EJECTING
SHORTWAVE TROUGH. FORCING FROM THIS FEATURE AND DEEPER MIXING OVER
THE HIGH PLAINS OF NERN CO THROUGH WRN KS WILL LIKELY SUPPORT
THUNDERSTORM INITIATION ALONG THE DRYLINE SOMETIME DURING THE NEXT
COUPLE HOURS.

VERTICAL SHEAR THROUGH A DEEP LAYER WILL REMAIN SUFFICIENT FOR
SUPERCELLS CAPABLE OF VERY LARGE HAIL GIVEN THE FAVORABLE LAPSE
RATES AND STRONG INSTABILITY. ALSO...THE THREAT FOR ISOLATED
TORNADOES IS EXPECTED TO INCREASE IN WINDOW FROM LATE AFTERNOON INTO
EARLY EVENING AS THE LLJ STRENGTHENS AND BEFORE THE BOUNDARY LAYER
DECOUPLES AND WHILE SOME STORMS MAY STILL BE DISCRETE. STORMS MAY
EVENTUALLY CONGEAL INTO ONE OR MORE CLUSTERS DURING THE
EVENING...WITH AN ATTENDANT INCREASE IN DAMAGING WIND THREAT.

..DIAL/KERR.. 05/18/2013

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

ATTN...WFO...GID...LBF...GLD...BOU...CYS...

LAT...LON   39030147 39950243 40740317 42060386 42720319 42270080
            39630003 38840064 39030147

000
ACUS11 KWNS 181910
SWOMCD
SPC MCD 181909
KSZ000-NEZ000-COZ000-182045-

MESOSCALE DISCUSSION 0675
NWS STORM PREDICTION CENTER NORMAN OK
0209 PM CDT SAT MAY 18 2013

AREAS AFFECTED...NWRN KS...NERN CO AND WRN NEB

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 181909Z - 182045Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO INITIATE BY 20-21Z FROM NERN CO
INTO NWRN KS AND EXTREME SERN WY...THEN SUBSEQUENTLY DEVELOP NEWD
INTO WRN NEB DURING THE EVENING. PRIMARY THREATS WILL BE VERY LARGE
HAIL AND ISOLATED TORNADOES. STORMS MAY EVENTUALLY GROW UPSCALE INTO
ONE OR MORE CLUSTERS LATER IN THE EVENING WITH AN INCREASING THREAT
FOR DAMAGING WIND. A TORNADO WATCH WILL LIKELY BE NEEDED PRIOR TO
21Z.

DISCUSSION...THIS AFTERNOON A DRYLINE EXTENDS FROM SERN WY TO A
MESOLOW NEAR THE KS/CO BORDER THEN FARTHER SWD THROUGH SWRN KS. THE
LATEST OBJECTIVE ANALYSIS INDICATES THE WARM SECTOR HAS BECOME VERY
UNSTABLE IN CORRIDOR FROM NWRN KS THROUGH EXTREME NERN CO AND WRN
NEB WHERE VERY STEEP LAPSE RATES /APPROACHING 9 C/KM/ HAVE
OVERSPREAD THE MOIST AXIS. SPECIAL 18Z RAOB FROM NORTH PLATTE NEB
INDICATES A STRONG CAPPING INVERSION IS STILL IN PLACE JUST BELOW
700 MB IN ASSOCIATION WITH WARM AIR AT BASE OF THE EML. THIS
SUGGESTS THUNDERSTORM INITIATION WILL LIKELY BE FARTHER WEST ACROSS
NERN CO AND NWRN KS. SATELLITE IMAGERY SHOWS MID-LEVEL CONVECTION
SPREADING RAPIDLY NWD ACROSS NERN CO AND NWRN KS AND APPEARS TO BE
IN ASSOCIATION WITH MID-LEVEL ASCENT ACCOMPANYING A NEWD EJECTING
SHORTWAVE TROUGH. FORCING FROM THIS FEATURE AND DEEPER MIXING OVER
THE HIGH PLAINS OF NERN CO THROUGH WRN KS WILL LIKELY SUPPORT
THUNDERSTORM INITIATION ALONG THE DRYLINE SOMETIME DURING THE NEXT
COUPLE HOURS.

VERTICAL SHEAR THROUGH A DEEP LAYER WILL REMAIN SUFFICIENT FOR
SUPERCELLS CAPABLE OF VERY LARGE HAIL GIVEN THE FAVORABLE LAPSE
RATES AND STRONG INSTABILITY. ALSO...THE THREAT FOR ISOLATED
TORNADOES IS EXPECTED TO INCREASE IN WINDOW FROM LATE AFTERNOON INTO
EARLY EVENING AS THE LLJ STRENGTHENS AND BEFORE THE BOUNDARY LAYER
DECOUPLES AND WHILE SOME STORMS MAY STILL BE DISCRETE. STORMS MAY
EVENTUALLY CONGEAL INTO ONE OR MORE CLUSTERS DURING THE
EVENING...WITH AN ATTENDANT INCREASE IN DAMAGING WIND THREAT.

..DIAL/KERR.. 05/18/2013

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

ATTN...WFO...GID...LBF...GLD...BOU...CYS...

LAT...LON   39030147 39950243 40740317 42060386 42720319 42270080
            39630003 38840064 39030147

000
ACUS11 KWNS 181910
SWOMCD
SPC MCD 181909
KSZ000-NEZ000-COZ000-182045-

MESOSCALE DISCUSSION 0675
NWS STORM PREDICTION CENTER NORMAN OK
0209 PM CDT SAT MAY 18 2013

AREAS AFFECTED...NWRN KS...NERN CO AND WRN NEB

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 181909Z - 182045Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO INITIATE BY 20-21Z FROM NERN CO
INTO NWRN KS AND EXTREME SERN WY...THEN SUBSEQUENTLY DEVELOP NEWD
INTO WRN NEB DURING THE EVENING. PRIMARY THREATS WILL BE VERY LARGE
HAIL AND ISOLATED TORNADOES. STORMS MAY EVENTUALLY GROW UPSCALE INTO
ONE OR MORE CLUSTERS LATER IN THE EVENING WITH AN INCREASING THREAT
FOR DAMAGING WIND. A TORNADO WATCH WILL LIKELY BE NEEDED PRIOR TO
21Z.

DISCUSSION...THIS AFTERNOON A DRYLINE EXTENDS FROM SERN WY TO A
MESOLOW NEAR THE KS/CO BORDER THEN FARTHER SWD THROUGH SWRN KS. THE
LATEST OBJECTIVE ANALYSIS INDICATES THE WARM SECTOR HAS BECOME VERY
UNSTABLE IN CORRIDOR FROM NWRN KS THROUGH EXTREME NERN CO AND WRN
NEB WHERE VERY STEEP LAPSE RATES /APPROACHING 9 C/KM/ HAVE
OVERSPREAD THE MOIST AXIS. SPECIAL 18Z RAOB FROM NORTH PLATTE NEB
INDICATES A STRONG CAPPING INVERSION IS STILL IN PLACE JUST BELOW
700 MB IN ASSOCIATION WITH WARM AIR AT BASE OF THE EML. THIS
SUGGESTS THUNDERSTORM INITIATION WILL LIKELY BE FARTHER WEST ACROSS
NERN CO AND NWRN KS. SATELLITE IMAGERY SHOWS MID-LEVEL CONVECTION
SPREADING RAPIDLY NWD ACROSS NERN CO AND NWRN KS AND APPEARS TO BE
IN ASSOCIATION WITH MID-LEVEL ASCENT ACCOMPANYING A NEWD EJECTING
SHORTWAVE TROUGH. FORCING FROM THIS FEATURE AND DEEPER MIXING OVER
THE HIGH PLAINS OF NERN CO THROUGH WRN KS WILL LIKELY SUPPORT
THUNDERSTORM INITIATION ALONG THE DRYLINE SOMETIME DURING THE NEXT
COUPLE HOURS.

VERTICAL SHEAR THROUGH A DEEP LAYER WILL REMAIN SUFFICIENT FOR
SUPERCELLS CAPABLE OF VERY LARGE HAIL GIVEN THE FAVORABLE LAPSE
RATES AND STRONG INSTABILITY. ALSO...THE THREAT FOR ISOLATED
TORNADOES IS EXPECTED TO INCREASE IN WINDOW FROM LATE AFTERNOON INTO
EARLY EVENING AS THE LLJ STRENGTHENS AND BEFORE THE BOUNDARY LAYER
DECOUPLES AND WHILE SOME STORMS MAY STILL BE DISCRETE. STORMS MAY
EVENTUALLY CONGEAL INTO ONE OR MORE CLUSTERS DURING THE
EVENING...WITH AN ATTENDANT INCREASE IN DAMAGING WIND THREAT.

..DIAL/KERR.. 05/18/2013

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

ATTN...WFO...GID...LBF...GLD...BOU...CYS...

LAT...LON   39030147 39950243 40740317 42060386 42720319 42270080
            39630003 38840064 39030147

000
ACUS02 KWNS 181710
SWODY2
SPC AC 181709

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1209 PM CDT SAT MAY 18 2013

VALID 191200Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF KS/OK/WRN MO...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
NCNTRL TX INTO SRN MN...

...REGIONAL SEVERE WEATHER OUTBREAK POSSIBLE ACROSS PARTS OF THE SRN
PLAINS...CNTRL PLAINS AND LOWER MO VALLEY...


...SRN PLAINS TO LOWER MO VALLEY....

LATEST MODEL GUIDANCE CONTINUES TO SUGGEST A SIGNIFICANT MID LEVEL
SPEED MAX WILL EVOLVE WITHIN THE BASE OF THE WRN U.S. TROUGH OVER
THE SRN ROCKIES LATE DAY1...THEN EJECT ACROSS THE SRN PLAINS TOWARD
WRN MO BY 20/00Z.  THERE ARE MINOR DIFFERENCES AMONG THE 12Z NAM/GFS
AND 00Z ECMWF...WITH THE NAM FAVORING A BIT MORE AGGRESSIVE SPEED
MAX/HEIGHT FALLS ACROSS NERN OK INTO SWRN MO THAN THE OTHER
GUIDANCE.  IT/S NOT ENTIRELY CLEAR IF THE MORE DISPLACED NAM SPEED
MAX IS CORRECT...IF SO THEN SIGNIFICANT SEVERE TSTM ACTIVITY COULD
SPREAD EAST OF DEPICTED MDT RISK.

FOR NOW WILL OPT FOR SOMEWHAT SLOWER GFS SOLUTION AS IT HAS BEEN
VERY CONSISTENT REGARDING THE FORECAST HEIGHT FIELD/WIND SPEEDS
ACROSS THE SRN PLAINS INTO WRN MO.  GIVEN THIS SOLUTION...AT SUNRISE
IT APPEARS SYNOPTIC FRONT WILL EXTEND FROM A SFC LOW OVER NCNTRL
NEB...SWD ACROSS CNTRL KS INTO THE TX PANHANDLE.  A DRYLINE IS
EXPECTED TO INTERSECT THE COLD FRONT OVER SWRN KS...EXTENDING SSWWD
INTO NWRN TX.  EARLY MORNING CONVECTION WILL LIKELY BE CONFINED TO
WARM ADVECTION ZONE ALONG THE NOSE OF THE LLJ ACROSS THE CNTRL
PLAINS INTO THE MID MS VALLEY.  SOUTH OF THIS ACTIVITY STRONG WARM
SECTOR BOUNDARY LAYER HEATING IS EXPECTED DURING THE
DAY...ESPECIALLY SOUTH OF I-70 CORRIDOR ACROSS KS/OK/TX.
COMBINATION OF STRONG HEATING AND STRENGTHENING WLY FLOW ALOFT WILL
ALLOW DRYLINE TO MIX TO A POSITION FROM CNTRL KS...SSWWD ACROSS SWRN
OK INTO NWRN TX BY 21Z.  IF HOWEVER THE NAM SOLUTION IS CORRECT THEN
THE DRYLINE MAY MIX TO THE I-35 CORRIDOR BY LATE AFTERNOON.

GIVEN THE EXPECTED INTENSE HEATING ALONG THE DRYLINE THERE IS AMPLE
REASON TO BELIEVE DISCRETE SUPERCELL STRUCTURES WILL EVOLVE
INITIALLY NORTH OF THE MID LEVEL JET CORE ACROSS KS...THEN SWD INTO
OK.  THIS MAY OCCUR BY 21Z OVER KS AND BY 20/00Z ACROSS OK TO NEAR
THE RED RIVER.  FORECAST SHEAR PROFILES STRONGLY FAVOR LONG-LIVED
SUPERCELLS AND WHERE DEW POINTS HOLD IN THE UPPER 60S/LOWER
70S...TORNADOES CAN BE EXPECTED.  GIVEN THE EXPECTED
SHEAR/INSTABILITY THERE IS SUPPORT FOR STRONG TORNADOES.
ADDITIONALLY...VERY LARGE HAIL SHOULD ACCOMPANY THIS ACTIVITY.
MATURING COMPLEX OF STORMS SHOULD PROGRESS ACROSS KS/NERN OK INTO
WRN MO WITH MORE SCATTERED ACTIVITY ACROSS CNTRL/SRN OK.

...SERN U.S...

REMNANT MID LEVEL SHORT-WAVE TROUGH WILL SHIFT ACROSS THE SRN
APPALACHIANS SUNDAY.  THIS FEATURE MAY ONCE AGAIN SERVE TO FOCUS A
FEW STRONG THUNDERSTORMS BENEATH A WEAKENING MID LEVEL WIND FIELD.
GUSTY WINDS OR PERHAPS SOME HAIL COULD BE NOTED WITH DIURNALLY
DRIVEN CONVECTION.

..DARROW.. 05/18/2013

000
ACUS02 KWNS 181710
SWODY2
SPC AC 181709

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1209 PM CDT SAT MAY 18 2013

VALID 191200Z - 201200Z

...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF KS/OK/WRN MO...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK FROM
NCNTRL TX INTO SRN MN...

...REGIONAL SEVERE WEATHER OUTBREAK POSSIBLE ACROSS PARTS OF THE SRN
PLAINS...CNTRL PLAINS AND LOWER MO VALLEY...


...SRN PLAINS TO LOWER MO VALLEY....

LATEST MODEL GUIDANCE CONTINUES TO SUGGEST A SIGNIFICANT MID LEVEL
SPEED MAX WILL EVOLVE WITHIN THE BASE OF THE WRN U.S. TROUGH OVER
THE SRN ROCKIES LATE DAY1...THEN EJECT ACROSS THE SRN PLAINS TOWARD
WRN MO BY 20/00Z.  THERE ARE MINOR DIFFERENCES AMONG THE 12Z NAM/GFS
AND 00Z ECMWF...WITH THE NAM FAVORING A BIT MORE AGGRESSIVE SPEED
MAX/HEIGHT FALLS ACROSS NERN OK INTO SWRN MO THAN THE OTHER
GUIDANCE.  IT/S NOT ENTIRELY CLEAR IF THE MORE DISPLACED NAM SPEED
MAX IS CORRECT...IF SO THEN SIGNIFICANT SEVERE TSTM ACTIVITY COULD
SPREAD EAST OF DEPICTED MDT RISK.

FOR NOW WILL OPT FOR SOMEWHAT SLOWER GFS SOLUTION AS IT HAS BEEN
VERY CONSISTENT REGARDING THE FORECAST HEIGHT FIELD/WIND SPEEDS
ACROSS THE SRN PLAINS INTO WRN MO.  GIVEN THIS SOLUTION...AT SUNRISE
IT APPEARS SYNOPTIC FRONT WILL EXTEND FROM A SFC LOW OVER NCNTRL
NEB...SWD ACROSS CNTRL KS INTO THE TX PANHANDLE.  A DRYLINE IS
EXPECTED TO INTERSECT THE COLD FRONT OVER SWRN KS...EXTENDING SSWWD
INTO NWRN TX.  EARLY MORNING CONVECTION WILL LIKELY BE CONFINED TO
WARM ADVECTION ZONE ALONG THE NOSE OF THE LLJ ACROSS THE CNTRL
PLAINS INTO THE MID MS VALLEY.  SOUTH OF THIS ACTIVITY STRONG WARM
SECTOR BOUNDARY LAYER HEATING IS EXPECTED DURING THE
DAY...ESPECIALLY SOUTH OF I-70 CORRIDOR ACROSS KS/OK/TX.
COMBINATION OF STRONG HEATING AND STRENGTHENING WLY FLOW ALOFT WILL
ALLOW DRYLINE TO MIX TO A POSITION FROM CNTRL KS...SSWWD ACROSS SWRN
OK INTO NWRN TX BY 21Z.  IF HOWEVER THE NAM SOLUTION IS CORRECT THEN
THE DRYLINE MAY MIX TO THE I-35 CORRIDOR BY LATE AFTERNOON.

GIVEN THE EXPECTED INTENSE HEATING ALONG THE DRYLINE THERE IS AMPLE
REASON TO BELIEVE DISCRETE SUPERCELL STRUCTURES WILL EVOLVE
INITIALLY NORTH OF THE MID LEVEL JET CORE ACROSS KS...THEN SWD INTO
OK.  THIS MAY OCCUR BY 21Z OVER KS AND BY 20/00Z ACROSS OK TO NEAR
THE RED RIVER.  FORECAST SHEAR PROFILES STRONGLY FAVOR LONG-LIVED
SUPERCELLS AND WHERE DEW POINTS HOLD IN THE UPPER 60S/LOWER
70S...TORNADOES CAN BE EXPECTED.  GIVEN THE EXPECTED
SHEAR/INSTABILITY THERE IS SUPPORT FOR STRONG TORNADOES.
ADDITIONALLY...VERY LARGE HAIL SHOULD ACCOMPANY THIS ACTIVITY.
MATURING COMPLEX OF STORMS SHOULD PROGRESS ACROSS KS/NERN OK INTO
WRN MO WITH MORE SCATTERED ACTIVITY ACROSS CNTRL/SRN OK.

...SERN U.S...

REMNANT MID LEVEL SHORT-WAVE TROUGH WILL SHIFT ACROSS THE SRN
APPALACHIANS SUNDAY.  THIS FEATURE MAY ONCE AGAIN SERVE TO FOCUS A
FEW STRONG THUNDERSTORMS BENEATH A WEAKENING MID LEVEL WIND FIELD.
GUSTY WINDS OR PERHAPS SOME HAIL COULD BE NOTED WITH DIURNALLY
DRIVEN CONVECTION.

..DARROW.. 05/18/2013

000
ACUS01 KWNS 181629
SWODY1
SPC AC 181627

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1127 AM CDT SAT MAY 18 2013

VALID 181630Z - 191200Z

...THERE IS A MDT RISK OF SVR TSTMS LATE THIS AFTN AND EVE ACROSS
PARTS OF SOUTHWEST AND SOUTH CENTRAL NEBRASKA...WESTERN AND CENTRAL
KANSAS...AND PARTS OF WESTERN OKLAHOMA...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK
AREA ACROSS MUCH OF THE PLAINS...

...SYNOPSIS...
IN ADVANCE OF THE UPPER TROUGH OVER THE INTERMOUNTAIN WEST...WARM
ELEVATED MIXED LAYER AIR HAS OVERSPREAD MOST OF THE PLAINS AND LOWER
MISSISSIPPI VALLEY.  THIS IS WHERE THE BOUNDARY LAYER CONTINUES TO
MOISTEN DUE TO BOTH EVAPOTRANSPIRATION AND A RETURN FLOW OF MOISTURE
OFF GULF OF MEXICO.  VEERED LOW-LEVEL FLOW /AT 850 MB/ TO A
SUBSTANTIAL WESTERLY COMPONENT APPEARS TO BE CUTTING OFF THE GULF
RETURN FLOW TO THE CENTRAL/NORTHERN PLAINS...THOUGH...AT LEAST
TEMPORARILY.  BUT THIS MAY BEGIN TO CHANGE BY THIS EVENING...AS
LOW-LEVEL FLOW BACKS TO A MORE PROMINENT SOUTHERLY COMPONENT...AND
STRENGTHENS...IN ASSOCIATION WITH DEEPENING AND CONSOLIDATION OF A
SURFACE LOW OVER THE CENTRAL PLAINS...AS MID-LEVEL HEIGHT FALLS
INCREASE TO THE EAST OF THE ROCKIES.

MODEST STRENGTHENING OF CYCLONIC MID/UPPER FLOW IS EXPECTED ACROSS
THE PLAINS TODAY...AS SEVERAL SMALLER SCALE IMPULSES BEGIN TO EMERGE
FROM THE INTERMOUNTAIN WEST.  STRONGEST FLOW ALOFT...HOWEVER...WILL
PERSIST IN A BELT ACROSS THE NORTH CENTRAL PACIFIC COAST INTO THE
SOUTHERN ROCKIES...BUT COULD BEGIN TO NOSE EASTWARD ACROSS THE TEXAS
PANHANDLE REGION TOWARD THE END OF THE FORECAST PERIOD.
STILL...GIVEN THE THERMODYNAMIC PROFILES EVOLVING ACROSS MUCH OF THE
PLAINS...WHICH WILL INCLUDE AREAS OF STRONG TO EXTREME CAPE...A RISK
FOR SEVERE THUNDERSTORMS WILL EXIST ACROSS A FAIRLY BROAD AREA.
ORGANIZED CLUSTERS OF STORMS APPEAR POSSIBLE...IN ADDITION TO THE
RISK FOR DISCRETE SUPERCELLS ...THE STRONGEST OF WHICH MAY BECOME
CAPABLE OF PRODUCING VERY LARGE HAIL AND A COUPLE OF TORNADOES.

ALTHOUGH SEVERE PROBABILITIES STILL SEEM  A BIT LOWER THAN THE
PLAINS...OTHER STRONG/ISOLATED SEVERE STORM DEVELOPMENT MAY ALSO
OCCUR TODAY EAST OF THE LOWER MISSISSIPPI VALLEY INTO PARTS OF THE
EASTERN GULF STATES.  THIS IS WHERE LOWER/MID TROPOSPHERIC WARM
ADVECTION ON THE EASTWARD ADVANCING EDGE OF WARMER ELEVATED MIXED
LAYER AIR...IN THE WAKE OF A WEAKENING UPPER IMPULSE ADVANCING
TOWARD THE SOUTH ATLANTIC COAST...MAY CONTRIBUTE TO INCREASING LIFT
AND STEEPENING MID-LEVEL LAPSE RATES.

...CENTRAL PLAINS...
AN INITIAL IMPULSE...NOW LIFTING NORTHEAST OF THE PANHANDLE REGION
INTO THE CENTRAL PLAINS...IS CONTRIBUTING TO SOME UNCERTAINTY
CONCERNING DRYLINE POSITION AND CONVECTIVE POTENTIAL LATER THIS
AFTERNOON...MAINLY SOUTH OF THE KANSAS/OKLAHOMA BORDER.
HOWEVER...THE DRYLINE IS STILL EXPECTED TO BE THE MAIN FOCUS FOR
STRONGEST DESTABILIZATION AND STORM DEVELOPMENT LATER THIS
AFTERNOON.  AIDED BY FORCING ASSOCIATED WITH CONTINUING MID-LEVEL
HEIGHT FALLS...SUBSTANTIAL MID-LEVEL INHIBITION IS EXPECTED TO
WEAKEN SUFFICIENTLY FOR THE INITIATION OF DISCRETE SUPERCELLS ACROSS
SOUTHWESTERN NEBRASKA INTO WESTERN KANSAS DURING THE 21-00Z TIME
FRAME...PERHAPS SOUTHWARD ACROSS WESTERN OKLAHOMA INTO NORTHWEST
TEXAS AS WELL.

VERY LARGE HAIL MAY BE THE PRIMARY SEVERE THREAT...INITIALLY... BUT
LOW-LEVEL LAPSE RATES PROBABLY WILL BE SUFFICIENTLY STEEP TO SUPPORT
A RISK FOR TORNADOES BENEATH INCREASINGLY CYCLONIC AND DIFLUENT
HIGH-LEVEL FLOW.  AS THE 850 MB JET BECOMES MORE SOUTHERLY AND
STRENGTHENS TO 40-50+ KT LATER THIS EVENING...A WINDOW OF
OPPORTUNITY WILL EXIST FOR INCREASING TORNADIC POTENTIAL...INCLUDING
THE RISK FOR ONE OR TWO STRONG TORNADOES.  THIS POTENTIAL APPEARS TO
HINGE LARGELY ON HOW LONG IT TAKES FOR CONVECTION TO GROW UPSCALE
INTO ORGANIZING MESOSCALE CONVECTIVE SYSTEMS...WITH DAMAGING
STRAIGHT LINE WINDS BECOMING A MORE PROMINENT THREAT.  THIS REMAINS
UNCERTAIN...BUT IT APPEARS THAT UPSCALE GROWTH COULD OCCUR FAIRLY
QUICKLY.

..KERR/DEAN.. 05/18/2013

000
ACUS01 KWNS 181629
SWODY1
SPC AC 181627

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1127 AM CDT SAT MAY 18 2013

VALID 181630Z - 191200Z

...THERE IS A MDT RISK OF SVR TSTMS LATE THIS AFTN AND EVE ACROSS
PARTS OF SOUTHWEST AND SOUTH CENTRAL NEBRASKA...WESTERN AND CENTRAL
KANSAS...AND PARTS OF WESTERN OKLAHOMA...

...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MODERATE RISK
AREA ACROSS MUCH OF THE PLAINS...

...SYNOPSIS...
IN ADVANCE OF THE UPPER TROUGH OVER THE INTERMOUNTAIN WEST...WARM
ELEVATED MIXED LAYER AIR HAS OVERSPREAD MOST OF THE PLAINS AND LOWER
MISSISSIPPI VALLEY.  THIS IS WHERE THE BOUNDARY LAYER CONTINUES TO
MOISTEN DUE TO BOTH EVAPOTRANSPIRATION AND A RETURN FLOW OF MOISTURE
OFF GULF OF MEXICO.  VEERED LOW-LEVEL FLOW /AT 850 MB/ TO A
SUBSTANTIAL WESTERLY COMPONENT APPEARS TO BE CUTTING OFF THE GULF
RETURN FLOW TO THE CENTRAL/NORTHERN PLAINS...THOUGH...AT LEAST
TEMPORARILY.  BUT THIS MAY BEGIN TO CHANGE BY THIS EVENING...AS
LOW-LEVEL FLOW BACKS TO A MORE PROMINENT SOUTHERLY COMPONENT...AND
STRENGTHENS...IN ASSOCIATION WITH DEEPENING AND CONSOLIDATION OF A
SURFACE LOW OVER THE CENTRAL PLAINS...AS MID-LEVEL HEIGHT FALLS
INCREASE TO THE EAST OF THE ROCKIES.

MODEST STRENGTHENING OF CYCLONIC MID/UPPER FLOW IS EXPECTED ACROSS
THE PLAINS TODAY...AS SEVERAL SMALLER SCALE IMPULSES BEGIN TO EMERGE
FROM THE INTERMOUNTAIN WEST.  STRONGEST FLOW ALOFT...HOWEVER...WILL
PERSIST IN A BELT ACROSS THE NORTH CENTRAL PACIFIC COAST INTO THE
SOUTHERN ROCKIES...BUT COULD BEGIN TO NOSE EASTWARD ACROSS THE TEXAS
PANHANDLE REGION TOWARD THE END OF THE FORECAST PERIOD.
STILL...GIVEN THE THERMODYNAMIC PROFILES EVOLVING ACROSS MUCH OF THE
PLAINS...WHICH WILL INCLUDE AREAS OF STRONG TO EXTREME CAPE...A RISK
FOR SEVERE THUNDERSTORMS WILL EXIST ACROSS A FAIRLY BROAD AREA.
ORGANIZED CLUSTERS OF STORMS APPEAR POSSIBLE...IN ADDITION TO THE
RISK FOR DISCRETE SUPERCELLS ...THE STRONGEST OF WHICH MAY BECOME
CAPABLE OF PRODUCING VERY LARGE HAIL AND A COUPLE OF TORNADOES.

ALTHOUGH SEVERE PROBABILITIES STILL SEEM  A BIT LOWER THAN THE
PLAINS...OTHER STRONG/ISOLATED SEVERE STORM DEVELOPMENT MAY ALSO
OCCUR TODAY EAST OF THE LOWER MISSISSIPPI VALLEY INTO PARTS OF THE
EASTERN GULF STATES.  THIS IS WHERE LOWER/MID TROPOSPHERIC WARM
ADVECTION ON THE EASTWARD ADVANCING EDGE OF WARMER ELEVATED MIXED
LAYER AIR...IN THE WAKE OF A WEAKENING UPPER IMPULSE ADVANCING
TOWARD THE SOUTH ATLANTIC COAST...MAY CONTRIBUTE TO INCREASING LIFT
AND STEEPENING MID-LEVEL LAPSE RATES.

...CENTRAL PLAINS...
AN INITIAL IMPULSE...NOW LIFTING NORTHEAST OF THE PANHANDLE REGION
INTO THE CENTRAL PLAINS...IS CONTRIBUTING TO SOME UNCERTAINTY
CONCERNING DRYLINE POSITION AND CONVECTIVE POTENTIAL LATER THIS
AFTERNOON...MAINLY SOUTH OF THE KANSAS/OKLAHOMA BORDER.
HOWEVER...THE DRYLINE IS STILL EXPECTED TO BE THE MAIN FOCUS FOR
STRONGEST DESTABILIZATION AND STORM DEVELOPMENT LATER THIS
AFTERNOON.  AIDED BY FORCING ASSOCIATED WITH CONTINUING MID-LEVEL
HEIGHT FALLS...SUBSTANTIAL MID-LEVEL INHIBITION IS EXPECTED TO
WEAKEN SUFFICIENTLY FOR THE INITIATION OF DISCRETE SUPERCELLS ACROSS
SOUTHWESTERN NEBRASKA INTO WESTERN KANSAS DURING THE 21-00Z TIME
FRAME...PERHAPS SOUTHWARD ACROSS WESTERN OKLAHOMA INTO NORTHWEST
TEXAS AS WELL.

VERY LARGE HAIL MAY BE THE PRIMARY SEVERE THREAT...INITIALLY... BUT
LOW-LEVEL LAPSE RATES PROBABLY WILL BE SUFFICIENTLY STEEP TO SUPPORT
A RISK FOR TORNADOES BENEATH INCREASINGLY CYCLONIC AND DIFLUENT
HIGH-LEVEL FLOW.  AS THE 850 MB JET BECOMES MORE SOUTHERLY AND
STRENGTHENS TO 40-50+ KT LATER THIS EVENING...A WINDOW OF
OPPORTUNITY WILL EXIST FOR INCREASING TORNADIC POTENTIAL...INCLUDING
THE RISK FOR ONE OR TWO STRONG TORNADOES.  THIS POTENTIAL APPEARS TO
HINGE LARGELY ON HOW LONG IT TAKES FOR CONVECTION TO GROW UPSCALE
INTO ORGANIZING MESOSCALE CONVECTIVE SYSTEMS...WITH DAMAGING
STRAIGHT LINE WINDS BECOMING A MORE PROMINENT THREAT.  THIS REMAINS
UNCERTAIN...BUT IT APPEARS THAT UPSCALE GROWTH COULD OCCUR FAIRLY
QUICKLY.

..KERR/DEAN.. 05/18/2013

000
ACUS01 KWNS 181257
SWODY1
SPC AC 181254

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0754 AM CDT SAT MAY 18 2013

VALID 181300Z - 191200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER
PORTIONS OF SOUTHWEST NEB...WESTERN KS...AND WESTERN OK...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE GREAT PLAINS
AND UPPER MIDWEST...

...ACTIVE SEVERE WEATHER EVENT EXPECTED ACROSS PARTS OF NEB/KS/OK
LATER THIS AFTERNOON AND EVENING...

...NEB/KS/OK...
MORNING WATER VAPOR LOOPS SHOW A BROAD UPPER TROUGH OVER THE WESTERN
STATES...WITH SEVERAL SHORTWAVE TROUGHS EMBEDDED IN THE CYCLONIC
FLOW.  ONE SHORTWAVE TROUGH CURRENTLY OVER WESTERN AZ IS EXPECTED TO
EMERGE INTO THE CENTRAL PLAINS THIS EVENING...PROVIDING THE FOCUS
FOR SEVERE THUNDERSTORM DEVELOPMENT.  AHEAD OF THE
TROUGH...SOUTHERLY LOW LEVEL WINDS WILL MAINTAIN AMPLE MOISTURE
ACROSS THE PLAINS WITH 60S TO LOWER 70S DEWPOINTS EXPECTED FROM
CENTRAL/WESTERN KS INTO OK AND NORTH TX.  THE DRYLINE IS FORECAST TO
BECOME ESTABLISHED FROM WESTERN OK INTO THE EXTREME EASTERN TX
PANHANDLE BY MID/LATE AFTERNOON.  STRONG HEATING AND DEEP MIXING
BEHIND THE DRYLINE COUPLED WITH WEAK BUT SUSTAINED LARGE SCALE
ASCENT ASSOCIATED WITH THE WESTERN TROUGH WILL EVENTUALLY ERODE THE
CAP.  RAPID THUNDERSTORM DEVELOPMENT WILL BEGIN OVER WESTERN KS BY
20Z...WITH ACTIVITY DEVELOPING SOUTHWARD ALONG THE OK/TX PANHANDLE
BORDER BY LATE AFTERNOON.  FAVORABLE EFFECTIVE SHEAR AND VERY HIGH
CAPE VALUES /MLCAPE OF 3500+ J/KG/ WILL PROMOTE SUPERCELLS CAPABLE
OF VERY LARGE HAIL.  LCL HEIGHTS AND LOW LEVEL SHEAR ARE NOT
FORECAST TO BE PARTICULARLY FAVORABLE FOR TORNADOES...BUT DEGREE OF
INSTABILITY MAY COMPENSATE FOR NEGATIVE FACTORS SO HAVE MAINTAINED
RISK OF ISOLATED STRONG TORNADOES ACROSS MUCH OF THE MODERATE RISK
AREA.  THUNDERSTORMS ARE LIKELY TO GROW UPSCALE THROUGH THE EVENING
AS A BROKEN LINE MOVES EASTWARD INTO CENTRAL KS AND NORTH-CENTRAL OK
WITH AN INCREASED RISK OF DAMAGING WINDS.

...TX...
SEVERAL MODEL SOLUTIONS INDICATE THAT AT LEAST WIDELY SCATTERED
THUNDERSTORMS WILL DEVELOP BY LATE AFTERNOON ALONG THE
DRYLINE...PERHAPS AS FAR SOUTH AS DYS/BWD.  FORCING WILL BE WEAK BUT
STRONGER THAN YESTERDAY.  ANY STORM THAT FORMS ALONG THE CORRIDOR
WILL LIKELY BECOME SUPERCELLULAR WITH A RISK OF VERY LARGE HAIL AND
DAMAGING WINDS.

...SD/ND/MN/IA...
MULTIPLE CLUSTERS OF THUNDERSTORMS ARE ONGOING THIS MORNING OVER
EASTERN SD INTO MN/WI.  SOME INTENSIFICATION IS POSSIBLE ALONG THE
LEADING EDGE OF THIS ACTIVITY LATER THIS MORNING...BUT THE PRIMARY
SEVERE THREAT WILL LIKELY OCCUR LATE THIS AFTERNOON AND EVENING AS
NEW STORMS FORM OVER NEB/SD AND SPREAD EAST-NORTHEASTWARD.  DETAILS
OF CONVECTIVE EVOLUTION ARE UNCLEAR AT THIS TIME DUE TO ONGOING
STORMS...BUT IT APPEARS THAT HAIL AND DAMAGING WINDS WILL BE
POSSIBLE WITH STRONGER STORMS ACROSS MUCH OF THE NORTHERN PLAINS AND
UPPER MIDWEST LATER TODAY.

...SOUTHEAST STATES...
A REMNANT UPPER TROUGH REMAINS OVER THE TN VALLEY AND SOUTHEAST
STATES TODAY.  THIS WILL LEAD TO ANOTHER DAY OF SCATTERED
THUNDERSTORMS OVER A RELATIVELY LARGE AREA.  IT APPEARS THE CORRIDOR
MOST LIKELY TO SEE A FEW STRONG STORMS WILL BE FROM CENTRAL AL INTO
SOUTHWEST GA AND NORTH FL WHERE STRONG HEATING/DESTABILIZATION WILL
OCCUR.  STORMS CURRENTLY OVER CENTRAL AL ARE EXPECTED TO SPREAD
SOUTHEASTWARD ACROSS THIS REGION POSING A RISK OF LOCALLY DAMAGING
WINDS AND HAIL.

..HART/LEITMAN.. 05/18/2013

000
ACUS01 KWNS 181257
SWODY1
SPC AC 181254

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0754 AM CDT SAT MAY 18 2013

VALID 181300Z - 191200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER
PORTIONS OF SOUTHWEST NEB...WESTERN KS...AND WESTERN OK...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE GREAT PLAINS
AND UPPER MIDWEST...

...ACTIVE SEVERE WEATHER EVENT EXPECTED ACROSS PARTS OF NEB/KS/OK
LATER THIS AFTERNOON AND EVENING...

...NEB/KS/OK...
MORNING WATER VAPOR LOOPS SHOW A BROAD UPPER TROUGH OVER THE WESTERN
STATES...WITH SEVERAL SHORTWAVE TROUGHS EMBEDDED IN THE CYCLONIC
FLOW.  ONE SHORTWAVE TROUGH CURRENTLY OVER WESTERN AZ IS EXPECTED TO
EMERGE INTO THE CENTRAL PLAINS THIS EVENING...PROVIDING THE FOCUS
FOR SEVERE THUNDERSTORM DEVELOPMENT.  AHEAD OF THE
TROUGH...SOUTHERLY LOW LEVEL WINDS WILL MAINTAIN AMPLE MOISTURE
ACROSS THE PLAINS WITH 60S TO LOWER 70S DEWPOINTS EXPECTED FROM
CENTRAL/WESTERN KS INTO OK AND NORTH TX.  THE DRYLINE IS FORECAST TO
BECOME ESTABLISHED FROM WESTERN OK INTO THE EXTREME EASTERN TX
PANHANDLE BY MID/LATE AFTERNOON.  STRONG HEATING AND DEEP MIXING
BEHIND THE DRYLINE COUPLED WITH WEAK BUT SUSTAINED LARGE SCALE
ASCENT ASSOCIATED WITH THE WESTERN TROUGH WILL EVENTUALLY ERODE THE
CAP.  RAPID THUNDERSTORM DEVELOPMENT WILL BEGIN OVER WESTERN KS BY
20Z...WITH ACTIVITY DEVELOPING SOUTHWARD ALONG THE OK/TX PANHANDLE
BORDER BY LATE AFTERNOON.  FAVORABLE EFFECTIVE SHEAR AND VERY HIGH
CAPE VALUES /MLCAPE OF 3500+ J/KG/ WILL PROMOTE SUPERCELLS CAPABLE
OF VERY LARGE HAIL.  LCL HEIGHTS AND LOW LEVEL SHEAR ARE NOT
FORECAST TO BE PARTICULARLY FAVORABLE FOR TORNADOES...BUT DEGREE OF
INSTABILITY MAY COMPENSATE FOR NEGATIVE FACTORS SO HAVE MAINTAINED
RISK OF ISOLATED STRONG TORNADOES ACROSS MUCH OF THE MODERATE RISK
AREA.  THUNDERSTORMS ARE LIKELY TO GROW UPSCALE THROUGH THE EVENING
AS A BROKEN LINE MOVES EASTWARD INTO CENTRAL KS AND NORTH-CENTRAL OK
WITH AN INCREASED RISK OF DAMAGING WINDS.

...TX...
SEVERAL MODEL SOLUTIONS INDICATE THAT AT LEAST WIDELY SCATTERED
THUNDERSTORMS WILL DEVELOP BY LATE AFTERNOON ALONG THE
DRYLINE...PERHAPS AS FAR SOUTH AS DYS/BWD.  FORCING WILL BE WEAK BUT
STRONGER THAN YESTERDAY.  ANY STORM THAT FORMS ALONG THE CORRIDOR
WILL LIKELY BECOME SUPERCELLULAR WITH A RISK OF VERY LARGE HAIL AND
DAMAGING WINDS.

...SD/ND/MN/IA...
MULTIPLE CLUSTERS OF THUNDERSTORMS ARE ONGOING THIS MORNING OVER
EASTERN SD INTO MN/WI.  SOME INTENSIFICATION IS POSSIBLE ALONG THE
LEADING EDGE OF THIS ACTIVITY LATER THIS MORNING...BUT THE PRIMARY
SEVERE THREAT WILL LIKELY OCCUR LATE THIS AFTERNOON AND EVENING AS
NEW STORMS FORM OVER NEB/SD AND SPREAD EAST-NORTHEASTWARD.  DETAILS
OF CONVECTIVE EVOLUTION ARE UNCLEAR AT THIS TIME DUE TO ONGOING
STORMS...BUT IT APPEARS THAT HAIL AND DAMAGING WINDS WILL BE
POSSIBLE WITH STRONGER STORMS ACROSS MUCH OF THE NORTHERN PLAINS AND
UPPER MIDWEST LATER TODAY.

...SOUTHEAST STATES...
A REMNANT UPPER TROUGH REMAINS OVER THE TN VALLEY AND SOUTHEAST
STATES TODAY.  THIS WILL LEAD TO ANOTHER DAY OF SCATTERED
THUNDERSTORMS OVER A RELATIVELY LARGE AREA.  IT APPEARS THE CORRIDOR
MOST LIKELY TO SEE A FEW STRONG STORMS WILL BE FROM CENTRAL AL INTO
SOUTHWEST GA AND NORTH FL WHERE STRONG HEATING/DESTABILIZATION WILL
OCCUR.  STORMS CURRENTLY OVER CENTRAL AL ARE EXPECTED TO SPREAD
SOUTHEASTWARD ACROSS THIS REGION POSING A RISK OF LOCALLY DAMAGING
WINDS AND HAIL.

..HART/LEITMAN.. 05/18/2013