SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 AM CDT TUE JUL 20 2010 VALID 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR E CNTRL NV...W CNTRL UT... NO CHANGES MADE TO THE PREVIOUS D2 FORECAST. ..GARNER.. 07/20/2010 .PREV DISCUSSION... /ISSUED 0458 AM CDT TUE JUL 20 2010/ ...SYNOPSIS... AN UPPER TROUGH DIGGING INTO THE PACIFIC NW AT THE START OF THE PERIOD WILL EJECT EWD DURING THE DAY...WHILE AN UPPER ANTICYCLONE CONTINUES TO SHIFT SLOWLY EWD ACROSS THE SRN PLAINS. BETWEEN THESE TWO FEATURES...LOW/MID SWLY FLOW WILL INCREASE ACROSS THE GREAT BASIN AREA INTO WY. ...E CNTRL NV...W CNTRL UT... DEEP SWLY FLOW WILL INCREASE ACROSS THE AREA ON WEDNESDAY...WITH MID-LEVEL WIND SPEEDS INCREASING TO THE 35-40 MPH RANGE. STRONG AFTERNOON HEATING WILL RESULT IN A DEEPLY MIXED BOUNDARY LAYER...WITH THE POTENTIAL FOR SUSTAINED SURFACE WINDS OF 20-25 MPH WITH HIGHER GUSTS. THESE WINDS...COMBINED WITH RH VALUES BELOW 15 PERCENT...WILL RESULT IN THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS DURING THE AFTERNOON AND EARLY EVENING. ...NERN UT...SWRN/S CNTRL WY... INCREASING SWLY FLOW ALOFT WILL LEAD TO THE POTENTIAL FOR AFTERNOON SUSTAINED WINDS NEAR 20 MPH. THE EXTENT OF LOW RH VALUES IS UNCERTAIN AS THIS TIME...BUT NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE DURING THE PEAK HEATING HOURS ACROSS THE AREA. ALSO...AHEAD OF THE EJECTING UPPER TROUGH...SOME INCREASE IN MID-LEVEL MOISTURE IS POSSIBLE...WITH PW VALUES RISING TO THE 0.5-0.7 IN RANGE. THIS WILL LEAD TO THE POTENTIAL FOR ISOLATED DRY THUNDERSTORMS DURING THE LATE AFTERNOON. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1125 AM CDT TUE JUL 20 2010 VALID 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR E CNTRL NV...W CNTRL UT... NO CHANGES MADE TO THE PREVIOUS D2 FORECAST. ..GARNER.. 07/20/2010 .PREV DISCUSSION... /ISSUED 0458 AM CDT TUE JUL 20 2010/ ...SYNOPSIS... AN UPPER TROUGH DIGGING INTO THE PACIFIC NW AT THE START OF THE PERIOD WILL EJECT EWD DURING THE DAY...WHILE AN UPPER ANTICYCLONE CONTINUES TO SHIFT SLOWLY EWD ACROSS THE SRN PLAINS. BETWEEN THESE TWO FEATURES...LOW/MID SWLY FLOW WILL INCREASE ACROSS THE GREAT BASIN AREA INTO WY. ...E CNTRL NV...W CNTRL UT... DEEP SWLY FLOW WILL INCREASE ACROSS THE AREA ON WEDNESDAY...WITH MID-LEVEL WIND SPEEDS INCREASING TO THE 35-40 MPH RANGE. STRONG AFTERNOON HEATING WILL RESULT IN A DEEPLY MIXED BOUNDARY LAYER...WITH THE POTENTIAL FOR SUSTAINED SURFACE WINDS OF 20-25 MPH WITH HIGHER GUSTS. THESE WINDS...COMBINED WITH RH VALUES BELOW 15 PERCENT...WILL RESULT IN THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS DURING THE AFTERNOON AND EARLY EVENING. ...NERN UT...SWRN/S CNTRL WY... INCREASING SWLY FLOW ALOFT WILL LEAD TO THE POTENTIAL FOR AFTERNOON SUSTAINED WINDS NEAR 20 MPH. THE EXTENT OF LOW RH VALUES IS UNCERTAIN AS THIS TIME...BUT NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE DURING THE PEAK HEATING HOURS ACROSS THE AREA. ALSO...AHEAD OF THE EJECTING UPPER TROUGH...SOME INCREASE IN MID-LEVEL MOISTURE IS POSSIBLE...WITH PW VALUES RISING TO THE 0.5-0.7 IN RANGE. THIS WILL LEAD TO THE POTENTIAL FOR ISOLATED DRY THUNDERSTORMS DURING THE LATE AFTERNOON. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 1 Fire Weather Outlook
DAY 1 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CDT TUE JUL 20 2010 VALID 201700Z - 211200Z ...NO CRITICAL AREAS... ...ERN MOJAVE DESERT INTO SRN NV... NO CHANGES MADE TO PREVIOUS FORECAST. ...SRN-CENTRAL UT... WATER VAPOR SATELLITE IMAGERY AND GPS PW GUIDANCE SHOW A PLUME OF MOISTURE /CHARACTERIZED BY PWAT VALUES AROUND 1 INCH/ MOVING W-NWWD ACROSS AZ THIS MORNING. BY AFTERNOON...THIS MOISTURE WILL BEGIN TO ENTER SRN UT...WHICH WILL FAVOR ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT AS THE BOUNDARY LAYER DESTABILIZES. FORECAST SOUNDINGS INDICATE A FEW OF THESE STORMS MAY POSE A MARGINAL THREAT FOR DRY THUNDER OVER SRN-CENTRAL UT /BETWEEN THE GREATER MOISTURE OVER SRN UT AND DRIER AIR MASS OVER NRN UT/. HOWEVER...THE POTENTIAL IS EXPECTED TO BE TOO LOW TO WARRANT A CRITICAL OUTLOOK AREA. ..GARNER.. 07/20/2010 .PREV DISCUSSION... /ISSUED 0222 AM CDT TUE JUL 20 2010/ ...SYNOPSIS... AN UPPER TROUGH OVER THE NRN ROCKIES AT THE START OF THE PERIOD WILL PROGRESS EWD...WHILE ANOTHER TROUGH BEGINS TO DIG INTO THE PACIFIC NW. MEANWHILE...THE PERSISTENT UPPER ANTICYCLONE OVER THE SWRN CONUS WILL BEGIN TO WEAKEN AND SHIFT EWD. ...ERN MOJAVE DESERT INTO SRN NV... A HOT AND DRY AIRMASS REMAINS IN PLACE ACROSS THE REGION...WITH TEMPS RISING ABOVE 100 AND RH/S FALLING TO AROUND 10 PERCENT. MID-LEVEL SWLY FLOW WILL INCREASE SOMEWHAT ON THE BACKSIDE OF THE RETREATING RIDGE...WHILE LOW-LEVEL SWLY FLOW OF 20-25 MPH WILL REMAIN IN PLACE. SURFACE WINDS SHOULD REMAIN SUBCRITICAL...WITH SUSTAINED 15-20 MPH EXPECTED...BUT SEVERAL HOURS OF NEAR CRITICAL CONDITIONS ARE POSSIBLE DURING THE AFTERNOON. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC Day 1 Fire Weather Outlook
DAY 1 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CDT TUE JUL 20 2010 VALID 201700Z - 211200Z ...NO CRITICAL AREAS... ...ERN MOJAVE DESERT INTO SRN NV... NO CHANGES MADE TO PREVIOUS FORECAST. ...SRN-CENTRAL UT... WATER VAPOR SATELLITE IMAGERY AND GPS PW GUIDANCE SHOW A PLUME OF MOISTURE /CHARACTERIZED BY PWAT VALUES AROUND 1 INCH/ MOVING W-NWWD ACROSS AZ THIS MORNING. BY AFTERNOON...THIS MOISTURE WILL BEGIN TO ENTER SRN UT...WHICH WILL FAVOR ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT AS THE BOUNDARY LAYER DESTABILIZES. FORECAST SOUNDINGS INDICATE A FEW OF THESE STORMS MAY POSE A MARGINAL THREAT FOR DRY THUNDER OVER SRN-CENTRAL UT /BETWEEN THE GREATER MOISTURE OVER SRN UT AND DRIER AIR MASS OVER NRN UT/. HOWEVER...THE POTENTIAL IS EXPECTED TO BE TOO LOW TO WARRANT A CRITICAL OUTLOOK AREA. ..GARNER.. 07/20/2010 .PREV DISCUSSION... /ISSUED 0222 AM CDT TUE JUL 20 2010/ ...SYNOPSIS... AN UPPER TROUGH OVER THE NRN ROCKIES AT THE START OF THE PERIOD WILL PROGRESS EWD...WHILE ANOTHER TROUGH BEGINS TO DIG INTO THE PACIFIC NW. MEANWHILE...THE PERSISTENT UPPER ANTICYCLONE OVER THE SWRN CONUS WILL BEGIN TO WEAKEN AND SHIFT EWD. ...ERN MOJAVE DESERT INTO SRN NV... A HOT AND DRY AIRMASS REMAINS IN PLACE ACROSS THE REGION...WITH TEMPS RISING ABOVE 100 AND RH/S FALLING TO AROUND 10 PERCENT. MID-LEVEL SWLY FLOW WILL INCREASE SOMEWHAT ON THE BACKSIDE OF THE RETREATING RIDGE...WHILE LOW-LEVEL SWLY FLOW OF 20-25 MPH WILL REMAIN IN PLACE. SURFACE WINDS SHOULD REMAIN SUBCRITICAL...WITH SUSTAINED 15-20 MPH EXPECTED...BUT SEVERAL HOURS OF NEAR CRITICAL CONDITIONS ARE POSSIBLE DURING THE AFTERNOON. ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

SPC 1630Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1059 AM CDT TUE JUL 20 2010 VALID 201630Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EASTERN CO ACROSS THE MID MS VALLEY INTO THE MID ATLANTIC STATES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF WY/MT/SD... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WI... ZONAL FLOW PATTERN PERSISTS ACROSS THE NORTHERN STATES TODAY... WHILE A FLAT RIDGE CONTROLS THE WEATHER FROM THE SOUTHWEST INTO THE SOUTHEAST US. THE PRIMARY SURFACE BAROCLINIC ZONE EXTENDS FROM EASTERN CO...THROUGH THE MID MS VALLEY...INTO THE MID ATLANTIC STATES. THIS ZONE WILL BE THE FOCUS FOR STRONG TO SEVERE THUNDERSTORMS THROUGH THIS FORECAST PERIOD. ...MID MS AND LOWER OH VALLEYS... THE REMNANT MCS OVER MO/IL IS CONSIDERABLY WEAKER THAN A SIMILAR SYSTEM IN THIS REGION YESTERDAY...BUT DOES HAVE SOME MESOSCALE ORGANIZATION. POCKETS OF HEATING AND A VERY MOIST AIR MASS AHEAD OF THIS SYSTEM WILL POSE THE RISK OF REDEVELOPMENT THIS AFTERNOON OVER PARTS OF IND/OH/KY WITH DAMAGING WINDS THE MAIN THREAT. ...CENTRAL APPALACHIANS INTO MID ATLANTIC... A WARM/MOIST AIR MASS IS PRESENT TODAY FROM EASTERN KY/WV TO THE MID ATLANTIC COAST. EARLY AFTERNOON VISIBLE IMAGERY ALREADY SHOWS SOME CU DEVELOPMENT OVER THE MOUNTAINS...SUGGESTING AT LEAST SCATTERED THUNDERSTORMS WILL FORM AND SPREAD SLOWLY EASTWARD. HIGH TEMPERATURES WELL INTO THE 90S WILL CONTRIBUTE TO STEEP LOW LEVEL LAPSE RATES...WHILE PWAT VALUES APPROACHING 2 INCHES AID IN PRECIP LOADING. STRONGER STORMS IN THIS REGION WILL POSE A RISK OF LOCALLY DAMAGING DOWNBURST WINDS THIS AFTERNOON AND EVENING. ...EASTERN KS/MO THIS AFTERNOON AND EVENING... THE CURRENT MCS OVER MO/IL WILL TRACK EASTWARD THIS AFTERNOON...ALLOWING RAPID HEATING AND DESTABILIZATION OF MUCH OF MO. LIFT ALONG AND NORTH OF OUTFLOW BOUNDARY MAY RESULT IN RE-DEVELOPMENT OF THUNDERSTORMS. MLCAPE VALUES OVER 2500 J/KG AND SUFFICIENT EFFECTIVE SHEAR PROFILES INDICATE A RISK OF ORGANIZED MULTICELL AND SUPERCELL STORMS CAPABLE OF DAMAGING WINDS...HAIL...OR EVEN A TORNADO. ...SOUTHEAST CO INTO CENTRAL KS... WEAK SURFACE BOUNDARY CURRENTLY EXTENDS FROM NEAR LHX TO SLN. THIS AXIS IS EXPECTED TO BE THE FOCUS FOR SCATTERED THUNDERSTORMS LATE THIS AFTERNOON INTO EVENING. STRONGER CAPPING AND WEAK FORCING IN THIS REGION MAY LIMIT THE NUMBER OF STORMS. HOWEVER...STEEP MID LEVEL LAPSE RATES AND TURNING/INCREASING WINDS WITH HEIGHT POSE A CONDITIONAL RISK OF SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WINDS. ...WY/MT/SD... WEAK UPSLOPE FLOW REGIME REMAINS TODAY OVER NORTHEAST WY AND ADJACENT PORTIONS OF MT/SD. FORCING MECHANISMS ARE HARDER TO IDENTIFY IN WATER VAPOR IMAGERY TODAY VS YESTERDAY. HOWEVER...IT APPEARS LIKELY THAT AT LEAST A FEW STORMS WILL FORM IN THIS REGION AND DEVELOP SOUTHEASTWARD. COLD TEMPERATURES ALOFT... STEEP LAPSE RATES...AND STRONG EFFECTIVE SHEAR SUPPORT A RISK OF SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS. ...WI/UPPER MI... A MID LEVEL SHORTWAVE TROUGH IS PASSING EASTWARD ACROSS MN. LARGE SCALE FORCING FOR ASCENT WILL OVERSPREAD WI BY EARLY AFTERNOON...WHERE BREAKS IN THE CLOUDS ARE ALLOWING SOME DESTABILIZATION. FORECAST SOUNDINGS SHOW FAVORABLE CAPE/SHEAR COMBINATIONS FOR A RISK OF ISOLATED SEVERE STORMS CAPABLE OF LARGE HAIL. ..HART/ROGERS.. 07/20/2010 Read more

SPC 1630Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1059 AM CDT TUE JUL 20 2010 VALID 201630Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM EASTERN CO ACROSS THE MID MS VALLEY INTO THE MID ATLANTIC STATES... ...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF WY/MT/SD... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF WI... ZONAL FLOW PATTERN PERSISTS ACROSS THE NORTHERN STATES TODAY... WHILE A FLAT RIDGE CONTROLS THE WEATHER FROM THE SOUTHWEST INTO THE SOUTHEAST US. THE PRIMARY SURFACE BAROCLINIC ZONE EXTENDS FROM EASTERN CO...THROUGH THE MID MS VALLEY...INTO THE MID ATLANTIC STATES. THIS ZONE WILL BE THE FOCUS FOR STRONG TO SEVERE THUNDERSTORMS THROUGH THIS FORECAST PERIOD. ...MID MS AND LOWER OH VALLEYS... THE REMNANT MCS OVER MO/IL IS CONSIDERABLY WEAKER THAN A SIMILAR SYSTEM IN THIS REGION YESTERDAY...BUT DOES HAVE SOME MESOSCALE ORGANIZATION. POCKETS OF HEATING AND A VERY MOIST AIR MASS AHEAD OF THIS SYSTEM WILL POSE THE RISK OF REDEVELOPMENT THIS AFTERNOON OVER PARTS OF IND/OH/KY WITH DAMAGING WINDS THE MAIN THREAT. ...CENTRAL APPALACHIANS INTO MID ATLANTIC... A WARM/MOIST AIR MASS IS PRESENT TODAY FROM EASTERN KY/WV TO THE MID ATLANTIC COAST. EARLY AFTERNOON VISIBLE IMAGERY ALREADY SHOWS SOME CU DEVELOPMENT OVER THE MOUNTAINS...SUGGESTING AT LEAST SCATTERED THUNDERSTORMS WILL FORM AND SPREAD SLOWLY EASTWARD. HIGH TEMPERATURES WELL INTO THE 90S WILL CONTRIBUTE TO STEEP LOW LEVEL LAPSE RATES...WHILE PWAT VALUES APPROACHING 2 INCHES AID IN PRECIP LOADING. STRONGER STORMS IN THIS REGION WILL POSE A RISK OF LOCALLY DAMAGING DOWNBURST WINDS THIS AFTERNOON AND EVENING. ...EASTERN KS/MO THIS AFTERNOON AND EVENING... THE CURRENT MCS OVER MO/IL WILL TRACK EASTWARD THIS AFTERNOON...ALLOWING RAPID HEATING AND DESTABILIZATION OF MUCH OF MO. LIFT ALONG AND NORTH OF OUTFLOW BOUNDARY MAY RESULT IN RE-DEVELOPMENT OF THUNDERSTORMS. MLCAPE VALUES OVER 2500 J/KG AND SUFFICIENT EFFECTIVE SHEAR PROFILES INDICATE A RISK OF ORGANIZED MULTICELL AND SUPERCELL STORMS CAPABLE OF DAMAGING WINDS...HAIL...OR EVEN A TORNADO. ...SOUTHEAST CO INTO CENTRAL KS... WEAK SURFACE BOUNDARY CURRENTLY EXTENDS FROM NEAR LHX TO SLN. THIS AXIS IS EXPECTED TO BE THE FOCUS FOR SCATTERED THUNDERSTORMS LATE THIS AFTERNOON INTO EVENING. STRONGER CAPPING AND WEAK FORCING IN THIS REGION MAY LIMIT THE NUMBER OF STORMS. HOWEVER...STEEP MID LEVEL LAPSE RATES AND TURNING/INCREASING WINDS WITH HEIGHT POSE A CONDITIONAL RISK OF SUPERCELLS CAPABLE OF LARGE HAIL AND DAMAGING WINDS. ...WY/MT/SD... WEAK UPSLOPE FLOW REGIME REMAINS TODAY OVER NORTHEAST WY AND ADJACENT PORTIONS OF MT/SD. FORCING MECHANISMS ARE HARDER TO IDENTIFY IN WATER VAPOR IMAGERY TODAY VS YESTERDAY. HOWEVER...IT APPEARS LIKELY THAT AT LEAST A FEW STORMS WILL FORM IN THIS REGION AND DEVELOP SOUTHEASTWARD. COLD TEMPERATURES ALOFT... STEEP LAPSE RATES...AND STRONG EFFECTIVE SHEAR SUPPORT A RISK OF SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS. ...WI/UPPER MI... A MID LEVEL SHORTWAVE TROUGH IS PASSING EASTWARD ACROSS MN. LARGE SCALE FORCING FOR ASCENT WILL OVERSPREAD WI BY EARLY AFTERNOON...WHERE BREAKS IN THE CLOUDS ARE ALLOWING SOME DESTABILIZATION. FORECAST SOUNDINGS SHOW FAVORABLE CAPE/SHEAR COMBINATIONS FOR A RISK OF ISOLATED SEVERE STORMS CAPABLE OF LARGE HAIL. ..HART/ROGERS.. 07/20/2010 Read more

MD 1380 CONCERNING SEVERE THUNDERSTORM WATCH 501... FOR SERN MO...SWRN IL
MESOSCALE DISCUSSION 1380 NWS STORM PREDICTION CENTER NORMAN OK 1059 AM CDT TUE JUL 20 2010 AREAS AFFECTED...SERN MO...SWRN IL CONCERNING...SEVERE THUNDERSTORM WATCH 501... VALID 201559Z - 201700Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 501 CONTINUES. THUNDERSTORM LINE FROM SRN IL INTO SERN MO CONTINUES TO WEAKEN AS IT MOVES SEWD INTO THE SRN PART OF WW 501. REMOTE SENSING DATA FROM IR SATELLITE...RADAR...AND LIGHTNING NETWORK INDICATE UPDRAFTS CONTINUE TO DIMINISH IN INTENSITY. THE LEADING EDGE OF THE OUTFLOW IS MOVING INTO A MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE OF 1500-2000 J/KG...THUS THERE IS POTENTIAL FOR CONVECTIVE SYSTEM MAINTENANCE AND POSSIBLE STRENGTHENING THIS AFTERNOON. HOWEVER...THE SYSTEM IS ALSO MOVING INTO PROGRESSIVELY WEAKER VERTICAL SHEAR WITH SWD EXTENT SO THERE IS SOME UNCERTAINTY REGARDING A RENEWED SEVERE THREAT. A NEW WW SOUTH/EAST OF WW 501 IS NOT PLANNED ATTM BUT TRENDS WILL BE MONITORED INTO THE AFTERNOON. ..WEISS.. 07/20/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...PAH...LSX...SGF... LAT...LON 37909137 38619091 39139021 39138970 38688907 38198919 37339013 37169106 37909137 Read more

WW 0501 Status Reports
STATUS REPORT ON WW 501 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 SE VIH TO 25 NNE FAM TO 20 E BLV. ..WEISS..07/20/10 ATTN...WFO...LSX... STATUS REPORT FOR WS 501 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC027-157-189-201640- IL . ILLINOIS COUNTIES INCLUDED ARE CLINTON RANDOLPH WASHINGTON MOC093-123-179-186-187-201640- MO . MISSOURI COUNTIES INCLUDED ARE IRON MADISON REYNOLDS STE. GENEVIEVE ST. FRANCOIS THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 501 SEVERE TSTM IL MO 201240Z - 201700Z
URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 501 NWS STORM PREDICTION CENTER NORMAN OK 740 AM CDT TUE JUL 20 2010 THE NWS STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR PORTIONS OF WEST CENTRAL ILLINOIS EAST CENTRAL MISSOURI EFFECTIVE THIS TUESDAY MORNING FROM 740 AM UNTIL NOON CDT. HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE MILES EITHER SIDE OF A LINE FROM 15 MILES EAST NORTHEAST OF ALTON ILLINOIS TO 65 MILES WEST NORTHWEST OF FARMINGTON MISSOURI. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1). REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES. DISCUSSION...MCS APPROACHING E CENTRAL MO HAS SHOWN SOME ACCELERATION TO THE SE AS WELL AS SMALL SCALE BOWING STRUCTURES WITHIN THE LARGE CONVECTIVE LINE. THE STORMS ARE MOVING SEWD ALONG A RESIDUAL OUTFLOW BOUNDARY FROM OVERNIGHT STORMS...AND DEEP-LAYER SHEAR AND INSTABILITY ARE SUFFICIENT TO MAINTAIN THE MCS FOR ANOTHER FEW HOURS. A FEW DAMAGING GUSTS WILL BE THE MAIN SEVERE THREAT THIS MORNING. AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM MOTION VECTOR 31040. ...THOMPSON Read more

WW 0501 Status Reports
STATUS REPORT ON WW 501 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 SE VIH TO 35 SW STL TO 10 N STL TO 30 SW SPI. ..WEISS..07/20/10 ATTN...WFO...LSX... STATUS REPORT FOR WS 501 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC027-117-119-133-157-163-189-201540- IL . ILLINOIS COUNTIES INCLUDED ARE CLINTON MACOUPIN MADISON MONROE RANDOLPH ST. CLAIR WASHINGTON MOC055-093-099-123-179-186-187-189-221-510-201540- MO . MISSOURI COUNTIES INCLUDED ARE CRAWFORD IRON JEFFERSON MADISON REYNOLDS STE. GENEVIEVE ST. FRANCOIS ST. LOUIS WASHINGTON MISSOURI INDEPENDENT CITIES INCLUDED ARE ST. LOUIS CITY Read more

WW 0501 Status Reports
STATUS REPORT ON WW 501 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ESE JEF TO 35 WNW STL TO 40 NNW STL TO 35 SE UIN. ..WEISS..07/20/10 ATTN...WFO...LSX... STATUS REPORT FOR WS 501 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC013-027-061-083-117-119-133-157-163-189-201440- IL . ILLINOIS COUNTIES INCLUDED ARE CALHOUN CLINTON GREENE JERSEY MACOUPIN MADISON MONROE RANDOLPH ST. CLAIR WASHINGTON MOC055-071-073-093-099-113-123-151-179-183-186-187-189-219-221- 510-201440- MO . MISSOURI COUNTIES INCLUDED ARE CRAWFORD FRANKLIN GASCONADE IRON JEFFERSON LINCOLN MADISON OSAGE REYNOLDS ST. CHARLES STE. GENEVIEVE ST. FRANCOIS ST. LOUIS WARREN WASHINGTON Read more

SPC 1300Z Day 1 Outlook
DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0752 AM CDT TUE JUL 20 2010 VALID 201300Z - 211200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL HIGH PLAINS TO THE CNTRL APPALACHIANS... ...THERE IS A SLGT RISK OF SVR TSTMS FOR NERN WY...FAR WRN SD... ...SYNOPSIS... MINIMAL CHANGE IN THE LARGE SCALE PATTERN EXPECTED TODAY AS A BELT OF SEASONABLY STRONG ZONAL FLOW PERSISTS NORTH OF ELONGATED RIDGE OVER THE SRN CONUS. THREE LOW AMPLITUDE SHORT WAVE PERTURBATIONS WILL HELP MODULATE THE LOCATION AND INTENSITY OF EPISODIC TSTM/MCS DEVELOPMENT ON THE SRN FRINGE OF THE STRONGER FLOW ALONG A QUASI-STATIONARY FRONT/COMPOSITE OUTFLOW...EXTENDING FROM THE CNTRL HIGH PLAINS EWD TO THE LOWER MID-ATLANTIC. ...CNTRL HIGH PLAINS TO THE LOWER MID-ATLANTIC... 00Z HI-RES WRF-NMM/NSSL RUNS APPEAR TO HAVE A REASONABLY CLOSE REFLECTION OF ONGOING MCS ACROSS THE LOWER MO VALLEY THIS MORNING...ALBEIT STILL TOO SLOW/FAR NORTH. BOTH SUGGEST ACTIVITY SHOULD EVOLVE E/SEWD THROUGH MIDDAY...PERSISTING ACROSS THE MID-MS VALLEY IN ASSOCIATION WITH AN UPPER MS VALLEY IMPULSE. THREAT FOR DAMAGING WINDS WILL LIKELY INCREASE IN CONCERT WITH THE DIURNAL HEATING CYCLE AS DESTABILIZATION STRENGTHENS S OF THIS CLUSTER. FARTHER E...BOTH HI-RES MODELS SUGGEST DYING TSTM CLUSTER OVER KY WILL INTENSIFY OVER THE CNTRL APPALACHIANS LATER THIS MORNING AND INTO THE LOWER MID-ATLANTIC THIS AFTERNOON. HOWEVER...WITH LEAD IMPULSE OVER THE LOWER GREAT LAKES SHIFTING RAPIDLY EWD...UNCERTAINTY EXISTS WHETHER SUBSTANTIAL REINTENSIFICATION OF THIS KY CLUSTER WILL OCCUR. THUS...WILL DEFER TO LATER OUTLOOKS FOR A CATEGORICAL UPGRADE TO SLIGHT RISK IN THE MID-ATLANTIC AREA. FARTHER W...PERSISTENCE OF 15-25 KT S/SWLY LOW-LEVEL FLOW WILL SUPPORT ADDITIONAL TSTM DEVELOPMENT THIS AFTERNOON ALONG COMPOSITE OUTFLOW/STATIONARY FRONT...MOST PROBABLE FROM NRN/CNTRL MO W/SWWD INTO SERN CO. A FEW SUPERCELLS SHOULD DEVELOP WITH INITIAL ACTIVITY...PRIMARILY FROM CNTRL KS INTO NRN/CNTRL MO...AS MID-LEVEL FLOW RAPIDLY WEAKENS WITH SWWD EXTENT. LARGE HAIL SHOULD BE A THREAT INITIALLY AS THE REGION LIES ON THE ERN FRINGE OF STEEP MID-LEVEL LAPSE RATES. HOWEVER...GIVEN MEAN STORM MOTION ROUGHLY PARALLEL TO THE INITIATING BOUNDARIES...UPSCALE GROWTH INTO ONE OR MORE TSTM CLUSTERS IS LIKELY DURING THE LATE AFTERNOON/EARLY EVENING. POTENTIAL FOR DAMAGING WINDS SHOULD LIKEWISE INCREASE AS CLUSTERS MATURE ALONG THE NRN PERIPHERY OF HIGH INSTABILITY EXPECTED TO DEVELOP ACROSS ERN KS INTO SRN IL. MCS/S MAY PERSIST WELL INTO EARLY WED AS THE LLJ STRENGTHENS ACROSS THE CNTRL/SRN PLAINS. ...NRN HIGH PLAINS... A MID-LEVEL IMPULSE OVER SRN ALBERTA/SWRN SASKATCHEWAN SHOULD EJECT E/SEWD INTO ND BY EARLY EVENING. DESPITE A NEARLY UNIDIRECTIONAL W/NWLY KINEMATIC PROFILE SERVING TO MIX SURFACE DEW POINTS INTO THE 40S BY THIS AFTERNOON IN ND...PRESENCE OF 40-50 KT FLOW AT 500 MB AND STEEP LOW/MID-LEVEL LAPSE RATES SHOULD PROMOTE POTENTIAL FOR A FEW SEVERE WIND/HAIL EVENTS. FARTHER SW...NEUTRAL TO MINOR MID-LEVEL HEIGHT RISES THROUGH THIS EVENING SHOULD MITIGATE MORE ROBUST TSTM COVERAGE COMPARED TO THE LAST COUPLE OF DAYS. IN ADDITION...NWLY LOWER-LEVEL FLOW IN THE WAKE OF THE DISTURBANCE CROSSING THE UPPER MS VALLEY HAS RESULTED IN DRYING ACROSS THE HIGH PLAINS...WITH RESIDUAL MOISTURE SUFFICIENT FOR DEEP CONVECTION BANKED ALONG THE IMMEDIATE LEE OF THE HIGHER TERRAIN. DEVELOPING WEAK UPSLOPE FLOW AMIDST RATHER STRONG DEEP-LAYER SHEAR SHOULD BE SUFFICIENT FOR A COUPLE OF SUPERCELLS THIS AFTERNOON CAPABLE OF PRODUCING LARGE HAIL AND SEVERE WIND GUSTS. ...UPPER GREAT LAKES... FORCED ASCENT ASSOCIATED WITH A MID-LEVEL IMPULSE OVER WRN MN SHOULD RESULT IN ISOLATED TO SCATTERED TSTM COVERAGE THIS AFTERNOON FROM ERN MN INTO MI. DESPITE 50S SURFACE DEW POINTS MITIGATING MORE ROBUST INSTABILITY...BELT OF STRONG MID-LEVEL WLYS IN ASSOCIATION WITH THE IMPULSE SHOULD AID IN A FEW SEVERE WIND AND HAIL EVENTS. ..GRAMS/THOMPSON/DEAN.. 07/20/2010 Read more

WW 500 SEVERE TSTM IA KS MO NE 200635Z - 201400Z
URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 500 NWS STORM PREDICTION CENTER NORMAN OK 135 AM CDT TUE JUL 20 2010 THE NWS STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR PORTIONS OF SOUTHWESTERN IOWA FAR NORTHEASTERN KANSAS NORTHWESTERN AND NORTH CENTRAL MISSOURI SOUTHEASTERN NEBRASKA EFFECTIVE THIS TUESDAY MORNING FROM 135 AM UNTIL 900 AM CDT. HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES WEST NORTHWEST OF BEATRICE NEBRASKA TO 45 MILES EAST NORTHEAST OF CHILLICOTHE MISSOURI. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0). REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES. OTHER WATCH INFORMATION...CONTINUE...WW 498...WW 499... DISCUSSION...A THREAT FOR DAMAGING WINDS AND HAIL WILL SPREAD ESEWD ACROSS SEVERE THUNDERSTORM WATCH 500 THROUGH THE OVERNIGHT TO EARLY MORNING TIME PERIOD. STRONG INSTABILITY AND EFFECTIVE BULK SHEAR EXCEEDING 50 KT WILL MAINTAIN THE LIKELIHOOD ORGANIZED STORMS TO AFFECT SERN NEB/FAR NERN KS INTO SWRN IA AND NWRN/NRN MO. AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM MOTION VECTOR 29035. ...PETERS/THOMPSON Read more

WW 0500 Status Reports
STATUS REPORT ON WW 500 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 ENE MKC TO 5 W CDJ TO 20 NW IRK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1378 ..THOMPSON..07/20/10 ATTN...WFO...EAX... STATUS REPORT FOR WS 500 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC005-043-201140- KS . KANSAS COUNTIES INCLUDED ARE ATCHISON DONIPHAN MOC001-003-005-021-025-033-041-047-049-061-063-075-079-081-087- 115-117-121-129-147-165-171-175-177-197-211-227-201140- MO . MISSOURI COUNTIES INCLUDED ARE ADAIR ANDREW ATCHISON BUCHANAN CALDWELL CARROLL CHARITON CLAY CLINTON DAVIESS DEKALB GENTRY GRUNDY HARRISON HOLT LINN LIVINGSTON MACON MERCER NODAWAY PLATTE PUTNAM RANDOLPH RAY SCHUYLER SULLIVAN WORTH Read more

WW 0500 Status Reports
STATUS REPORT ON WW 500 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 ENE MKC TO 5 W CDJ TO 20 NW IRK. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1378 ..THOMPSON..07/20/10 ATTN...WFO...EAX... STATUS REPORT FOR WS 500 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC005-043-201140- KS . KANSAS COUNTIES INCLUDED ARE ATCHISON DONIPHAN MOC001-003-005-021-025-033-041-047-049-061-063-075-079-081-087- 115-117-121-129-147-165-171-175-177-197-211-227-201140- MO . MISSOURI COUNTIES INCLUDED ARE ADAIR ANDREW ATCHISON BUCHANAN CALDWELL CARROLL CHARITON CLAY CLINTON DAVIESS DEKALB GENTRY GRUNDY HARRISON HOLT LINN LIVINGSTON MACON MERCER NODAWAY PLATTE PUTNAM RANDOLPH RAY SCHUYLER SULLIVAN WORTH Read more

MD 1378 CONCERNING SEVERE THUNDERSTORM WATCH 500... FOR NE...CENTRAL...AND E CENTRAL MO
MESOSCALE DISCUSSION 1378 NWS STORM PREDICTION CENTER NORMAN OK 0546 AM CDT TUE JUL 20 2010 AREAS AFFECTED...NE...CENTRAL...AND E CENTRAL MO CONCERNING...SEVERE THUNDERSTORM WATCH 500... VALID 201046Z - 201215Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 500 CONTINUES. THREAT FOR ISOLATED STRONG/SEVERE GUSTS WILL DECREASE GRADUALLY THIS MORNING AS REMNANT MCS MOVES SEWD AT 30-35 KT ACROSS MO. A NEW WW PROBABLY WILL NOT BE NEEDED DOWNSTREAM FROM WW 500. THE STRUCTURE OF THE MCS ACROSS NRN MO HAS BECOME MORE RAGGED DURING THE PAST 30-60 MINUTES...AND THE CONVECTION HAS ALREADY PROGRESSED THROUGH THE REGION OF STRONGEST INSTABILITY AND LOW-LEVEL MOISTURE TRANSPORT ACROSS NW/N CENTRAL MO. THE LLJ WILL CONTINUE TO VEER TO WLY AND WEAKEN THROUGH 12-13Z...WHICH ALSO SUGGESTS THAT THE MCS IS PAST PEAK. THUS...A NEW WATCH IS PROBABLY NOT NEEDED DOWNSTREAM OF WW 500 INTO CENTRAL/E CENTRAL MO. DESPITE LESSENING OF THE SEVERE STORM THREAT...LOCALLY HEAVY RAINFALL WILL CONTINUE TO BE A CONCERN ALONG THE STALLED OUTFLOW BOUNDARY FROM N CENTRAL INTO E CENTRAL MO FOR THE NEXT COUPLE OF HOURS...UNTIL THE ENTIRE CLUSTER BEGINS TO DISSIPATE. ..THOMPSON.. 07/20/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LSX...SGF...EAX... LAT...LON 38529298 39059365 39679362 40119318 40289257 40209214 39489165 38929108 38599089 38259104 38149177 38309279 38529298 Read more

SPC Day 2 Fire Weather Outlook
DAY 2 FIRE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0458 AM CDT TUE JUL 20 2010 VALID 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR E CNTRL NV...W CNTRL UT... ...SYNOPSIS... AN UPPER TROUGH DIGGING INTO THE PACIFIC NW AT THE START OF THE PERIOD WILL EJECT EWD DURING THE DAY...WHILE AN UPPER ANTICYCLONE CONTINUES TO SHIFT SLOWLY EWD ACROSS THE SRN PLAINS. BETWEEN THESE TWO FEATURES...LOW/MID SWLY FLOW WILL INCREASE ACROSS THE GREAT BASIN AREA INTO WY. ...E CNTRL NV...W CNTRL UT... DEEP SWLY FLOW WILL INCREASE ACROSS THE AREA ON WEDNESDAY...WITH MID-LEVEL WIND SPEEDS INCREASING TO THE 35-40 MPH RANGE. STRONG AFTERNOON HEATING WILL RESULT IN A DEEPLY MIXED BOUNDARY LAYER...WITH THE POTENTIAL FOR SUSTAINED SURFACE WINDS OF 20-25 MPH WITH HIGHER GUSTS. THESE WINDS...COMBINED WITH RH VALUES BELOW 15 PERCENT...WILL RESULT IN THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS DURING THE AFTERNOON AND EARLY EVENING. ...NERN UT...SWRN/S CNTRL WY... INCREASING SWLY FLOW ALOFT WILL LEAD TO THE POTENTIAL FOR AFTERNOON SUSTAINED WINDS NEAR 20 MPH. THE EXTENT OF LOW RH VALUES IS UNCERTAIN AS THIS TIME...BUT NEAR CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE DURING THE PEAK HEATING HOURS ACROSS THE AREA. ALSO...AHEAD OF THE EJECTING UPPER TROUGH...SOME INCREASE IN MID-LEVEL MOISTURE IS POSSIBLE...WITH PW VALUES RISING TO THE 0.5-0.7 IN RANGE. THIS WILL LEAD TO THE POTENTIAL FOR ISOLATED DRY THUNDERSTORMS DURING THE LATE AFTERNOON. ..DEAN/GRAMS.. 07/20/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV/FIRE FOR GRAPHIC PRODUCT... Read more

WW 0499 Status Reports
STATUS REPORT ON WW 499 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 W BIE TO 30 ESE GRI TO 30 WNW LNK. WW 499 WILL BE ALLOWED TO EXPIRE AT 201000Z. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1376 ..THOMPSON..07/20/10 ATTN...WFO...GID... STATUS REPORT FOR WS 499 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS KSC089-147-183-201000- KS . KANSAS COUNTIES INCLUDED ARE JEWELL PHILLIPS SMITH NEC001-019-035-047-059-061-065-073-077-079-081-083-093-099-121- 125-129-137-143-163-169-175-181-185-201000- NE . NEBRASKA COUNTIES INCLUDED ARE ADAMS BUFFALO CLAY DAWSON FILLMORE FRANKLIN FURNAS GOSPER GREELEY HALL HAMILTON HARLAN HOWARD KEARNEY MERRICK NANCE NUCKOLLS PHELPS POLK SHERMAN THAYER Read more

WW 499 SEVERE TSTM KS NE 200425Z - 201000Z
URGENT - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WATCH NUMBER 499 NWS STORM PREDICTION CENTER NORMAN OK 1125 PM CDT MON JUL 19 2010 THE NWS STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR PORTIONS OF NORTH CENTRAL KANSAS SOUTH CENTRAL NEBRASKA EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 1125 PM UNTIL 500 AM CDT. HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS. THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES WEST OF KEARNEY NEBRASKA TO 55 MILES EAST OF HASTINGS NEBRASKA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9). REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES. OTHER WATCH INFORMATION...CONTINUE...WW 498... DISCUSSION...FRONTAL BOUNDARY IS LOCATED IN FAR NRN KS AND SLY LOW LEVEL JET SHOULD INCREASE LIFT NORTH OF THE FRONT THROUGH THE NIGHT. STORMS ARE APPROACHING THE AREA FROM THE WEST AND OTHER NEW STORMS ARE EXPECTED TO DEVELOP DURING THE NEXT COUPLE OF HOURS. STRONG DEEP LAYER SHEAR AND STRONG INSTABILITY ARE FAVORABLE FOR SEVERE STORMS. IF THE STORMS CAN ORGANIZE INTO A LINE SEGMENT...THE THREAT FOR WIND DAMAGE WOULD INCREASE. AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM MOTION VECTOR 29025. ...IMY Read more

MD 1377 CONCERNING HEAVY RAINFALL FOR NE MO AND ADJACENT S CENTRAL IA
MESOSCALE DISCUSSION 1377 NWS STORM PREDICTION CENTER NORMAN OK 0439 AM CDT TUE JUL 20 2010 AREAS AFFECTED...NE MO AND ADJACENT S CENTRAL IA CONCERNING...HEAVY RAINFALL VALID 200939Z - 201115Z LOCALLY HEAVY RAINFALL THREAT WILL PERSIST FOR ROUGHLY ANOTHER TWO HOURS /THROUGH 1130Z/ WITH TRAINING STORMS ALONG MERGING OUTFLOW BOUNDARIES IN NE MO AND A SMALL PART OF S CENTRAL IA. A QUASI-STATIONARY NW-SE ORIENTED OUTFLOW BOUNDARY ACROSS NE MO IS PROVIDING A FOCUS FOR REPEAT THUNDERSTORM DEVELOPMENT AS A 45 KT SWLY/WSWLY LLJ TRANSPORTS RICH MOISTURE OVER THE COLD POOL. GIVEN PW VALUES NEAR 2.25 INCHES AND MODERATE INSTABILITY...EFFICIENT RAIN-PRODUCING STORMS WILL LIKELY PERSIST FOR ANOTHER COUPLE OF HOURS...ESPECIALLY ACROSS THE SE PORTION OF THE DISCUSSION AREA /ADAIR-SHELBY COUNTIES IN NE MO/. MEANWHILE...A SEPARATE OUTFLOW BOUNDARY/COLD POOL WITH ANOTHER THUNDERSTORM CLUSTER IN S CENTRAL IA/NW MO WILL CONTINUE TO DEVELOP SEWD AT 30-35 KT. RAINFALL RATES WILL BE ENHANCED AT THE MERGER OF THE TWO BOUNDARIES...WHILE SEWD PROGRESSION OF THE MERGER AT ABOUT 30 KT WILL BRING AN END TO THE HEAVY RAINFALL THREAT FROM NW-SE. ..THOMPSON.. 07/20/2010 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...LSX...DVN...DMX...EAX... LAT...LON 40209195 39789177 39709229 40129262 40489295 40659294 40759272 40499218 40209195 Read more