Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/22/15


AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1230 AM CDT MON JUL 20 2015 .AVIATION... OTHER THAN SUNRISE FOG AT KADF...VFR CONDITIONS WILL PREVAIL. CURRENT TSRA ACROSS SOUTHERN MISSOURI SHOULD STAY AWAY FROM THE NORTHERN SITES. AS THE COLD FRONT SAGS SOUTH TODAY...CLOUD COVER WILL INCREASE. PRECIP WILL HOLD OFF UNTIL AFTER THIS TAF CYCLE. && .PREV DISCUSSION... /ISSUED 939 PM CDT SUN JUL 19 2015/ UPDATE... QUICK UPDATE TO THE FORECAST WITH SHOWERS AND THUNDERSTORMS CONTINUING TO DEVELOP IN MISSOURI. IN ADDITION TO THE 12Z WRF AND 00Z NAM...THE LATEST HRRR RUNS HAVE SHOWED FAIRLY GOOD CONTINUITY WITH THESE THUNDERSTORMS CONTINUING TO DEVELOP AND PUSH SOUTH THROUGH THE OVERNIGHT AND EARLY MORNING HOURS ACROSS NORTHERN AND NORTHEAST ARKANSAS. CURRENT RADAR TRENDS DO SUGGEST THE BEST CHANCES FOR PRECIPITATION WILL BE TO THE NORTHEAST OF THE CWA...BUT WITHIN THE PAST HOUR ADDITIONAL STORMS HAVE BEGUN TO DEVELOP A BIT FURTHER TO THE WEST OF THE MAIN SET OF STORMS. AS SUCH...TOOK A CONSERVATIVE APPROACH FOR NOW AND JUST ADDED SOME SLIGHT CHANCE POPS TO NORTHERN ARKANSAS...AS THESE STORMS SHOULD WEAKEN DURING THE EARLY MORNING HOURS. && .LZK WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ARKANSAS-BRADLEY- CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW- FAULKNER-GARLAND-GRANT-HOT SPRING-INDEPENDENCE-JACKSON-JEFFERSON- LINCOLN-LONOKE-MONROE-OUACHITA-PERRY-PRAIRIE-PULASKI-SALINE- WHITE-WOODRUFF. && $$ AVIATION...58
AREA FORECAST DISCUSSION...UPDATED
NWS SAN JOAQUIN VALLEY - HANFORD CA
550 AM PDT MON JUL 20 2015 .UPDATE... UPDATED FOR URBAN AND SMALL STREAM FLOOD ADVISORY. && .SYNOPSIS... TROPICAL MOISTURE WILL CONTINUE FLOWING INTO THE REGION FROM THE SOUTH THROUGH THE REMAINDER OF TODAY. AS A RESULT...THERE WILL REMAIN A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. A DRYING TREND AND A RETURN TO SUMMER LIKE TEMPERATURES IS EXPECTED BY MID WEEK AS THE TROPICAL MOISTURE GETS PUSHED OUT OF OUR AREA. && .DISCUSSION... RUNOFF FROM THE STRONG THUNDERSTORMS OVER THE TEHACHAPI MOUNTAINS SUNDAY NIGHT HAS BEGUN SPILLING INTO THE FAR SOUTH END OF THE SAN JOAQUIN VALLEY. THE CALIFORNIA HIGHWAY PATROL HAS REPORTED SOME ROAD FLOODING AND MUD FLOWS ON ROADS IN THE SOUTH END. RUNOFF FROM THE MOUNTAINS LIKELY WILL CONTINUE OVER THE NEXT FEW HOURS. HAVE THEREFORE ISSUED AN URBAN AND SMALL STREAM FLOOD ADVISORY FOR THE SOUTH END OF THE SAN JOAQUIN VALLEY THROUGH 1615Z /0915 PDT/ THIS MORNING. && .PREV DISCUSSION... /ISSUED 250 AM PDT MON JUL 20 2015/ DISCUSSION... ALTHOUGH TROPICAL MOISTURE CONTINUED TO MOVE INTO CALIFORNIA SUNDAY THE FOCUS WAS OVER THE SOUTHERN PART OF THE STATE...INCLUDING KERN AND TULARE COUNTIES. THUNDERSTORMS CAUSED FLOODING AND MUD SLIDES IN THE TEHACHAPI AND SAN EMIGDIO MOUNTAINS...AND ALTHOUGH THE RAINS HAD TAPERED OFF AS OF 08Z /0100 PDT/...THE THREAT CONTINUED FROM SHOWERS AND THUNDERSTORMS OVER INYO AND SAN BERNARDINO COUNTIES. AN UPPER-LEVEL RIDGE PERSISTS OVER THE SOUTHERN UNITED STATES THIS MORNING AS AN UPPER-LEVEL TROUGH DROPS INTO THE PACIFIC NORTHWEST. THIS PATTERN RESULTS IN A SOUTHWESTERLY FLOW ALOFT OVER CENTRAL CALIFORNIA WHICH CARRIES TROPICAL MOISTURE FROM FORMER HURRICANE DOLORES INTO THE WFO HANFORD WARNING/FORECAST AREA. DESPITE LESS CLOUDS THAN ORIGINALLY ANTICIPATED...HIGH TEMPERATURES SUNDAY IN THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY WERE WELL BELOW NORMAL...IN THE UPPER 80S TO LOWER 90S. TEMPERATURES EARLY THIS MORNING WERE RUNNING SIMILAR TO EARLY SUNDAY MORNING...SO SHOULD SEE ANOTHER DAY WITH BELOW-NORMAL HIGHS. ALTHOUGH CONVECTION HAS TEMPORARILY CEASED OVER THE CENTRAL CALIFORNIA INTERIOR...THE MODELS KEEP ABUNDANT MID-LEVEL MOISTURE OVER AT LEAST THE SOUTHERN HALF OF THE WFO HANFORD WARNING/FORECAST AREA. OF INTEREST IS THAT BOTH THE NAM-12 AND THE HRRR HAVE LIMITED MOISTURE OVER MERCED AND MARIPOSA COUNTIES TODAY...WITH THE NAM-12 FINALLY BRINGING THE MOISTURE NORTHWARD THIS EVENING AS KERN COUNTY BEGINS TO DRY OUT. IF THIS VERIFIES...CONVECTION COULD CONTINUE OVER MUCH OF THE REGION NORTH OF KERN COUNTY OVERNIGHT RATHER THAN BEING CONFINED MAINLY TO THE SOUTHERN SIERRA NEVADA AFTER MIDNIGHT. SUNDAY MORNING/S RFC QPF GUIDANCE FOR INTERIOR CENTRAL CALIFORNIA CONTINUED A TREND OF BEING WETTER WITH EACH SUCCESSIVE RUN. THE RFC STORM-TOTAL QPF FOR THE SOUTHERN SIERRA NEVADA FORECAST POINTS WAS OVER AN INCH THROUGH TUESDAY MORNING. FURTHER SOUTH...ALTHOUGH THERE ARE NO FORECAST POINTS...THE GROUND IS SATURATED FROM SUNDAY/S RAIN SO THERE LIKELY WILL BE FLOODING FROM EXCESSIVE RUNOFF. WILL KEEP THE FLASH FLOOD WATCH FOR THE MOUNTAIN AND DESERT AREAS IN PLACE THROUGH THIS EVENING. AS THE TROUGH DROPS THROUGH THE PACIFIC NORTHWEST AND INTO CENTRAL CALIFORNIA THE SOUTHWEST FLOW ALOFT WILL STRENGTHEN AND BEGIN DRYING OUT THE REGION BEGINNING WEDNESDAY. IN TURN...THE RIDGE IS FORECAST TO BUILD BACK INTO CALIFORNIA WITH THE 500-MB 5880-METER HEIGHT LINE PUSHING NORTH OF THE WFO HANFORD WARNING/FORECAST AREA BY FRIDAY. && .AVIATION... SCATTERED THUNDERSTORM ACTIVITY WILL PERSIST ACROSS THE MOUNTAIN AND DESERT AREAS OF CENTRAL CALIFORNIA...WITH ISOLATED THUNDERSTORMS ALSO POSSIBLE IN THE SAN JOAQUIN VALLEY OVER THE NEXT 24 HOURS. THESE STORMS WILL BRING AREAS OF MVFR AND LOCAL IFR/VLIFR CONDITIONS ALONG WITH WITH SOME POSSIBLE MOUNTAIN OBSCURATIONS IN THE HIGHER TERRAIN. GUSTY AND ERRATIC WINDS AROUND 40 KTS CAN ALSO ACCOMPANY THE STORMS. OTHERWISE...VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL CALIFORNIA INTERIOR. && .AIR QUALITY ISSUES... NONE. && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM. THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 07-20 111:1908 81:1973 78:1938 54:1903 KFAT 07-21 112:1908 79:1987 82:2006 56:1973 KFAT 07-22 112:2006 83:1896 84:2006 56:1903 KBFL 07-20 112:1938 84:1973 82:1979 49:1906 KBFL 07-21 112:1938 81:1987 83:1969 50:1906 KBFL 07-22 113:1908 82:1984 88:1910 50:1903 && .HNX WATCHES/WARNINGS/ADVISORIES... URBAN AND SMALL STREAM FLOOD ADVISORY THROUGH 0915 PDT THIS MORNING FOR THE SOUTH END OF THE SAN JOAQUIN VALLEY /CAC029/. FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE SOUTHERN SIERRA NEVADA FROM YOSEMITE NATIONAL PARK TO THE KERN COUNTY LINE /CAZ096-097/. FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE KERN COUNTY MOUNTAINS AND DESERT AND THE INDIAN WELLS VALLEY /CAZ095-098-099/. && $$ PUBLIC...SANGER AVN/FW...DURFEE PREV DISCUSSION...SANGER SYNOPSIS...ANDERSEN WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
250 AM PDT MON JUL 20 2015 .SYNOPSIS... TROPICAL MOISTURE WILL CONTINUE FLOWING INTO THE REGION FROM THE SOUTH THROUGH THE REMAINDER OF TODAY. AS A RESULT...THERE WILL REMAIN A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING. A DRYING TREND AND A RETURN TO SUMMER LIKE TEMPERATURES IS EXPECTED BY MID WEEK AS THE TROPICAL MOISTURE GETS PUSHED OUT OF OUR AREA. && .DISCUSSION... ALTHOUGH TROPICAL MOISTURE CONTINUED TO MOVE INTO CALIFORNIA SUNDAY THE FOCUS WAS OVER THE SOUTHERN PART OF THE STATE...INCLUDING KERN AND TULARE COUNTIES. THUNDERSTORMS CAUSED FLOODING AND MUD SLIDES IN THE TEHACHAPI AND SAN EMIGDIO MOUNTAINS...AND ALTHOUGH THE RAINS HAD TAPERED OFF AS OF 08Z /0100 PDT/...THE THREAT CONTINUED FROM SHOWERS AND THUNDERSTORMS OVER INYO AND SAN BERNARDINO COUNTIES. AN UPPER-LEVEL RIDGE PERSISTS OVER THE SOUTHERN UNITED STATES THIS MORNING AS AN UPPER-LEVEL TROUGH DROPS INTO THE PACIFIC NORTHWEST. THIS PATTERN RESULTS IN A SOUTHWESTERLY FLOW ALOFT OVER CENTRAL CALIFORNIA WHICH CARRIES TROPICAL MOISTURE FROM FORMER HURRICANE DOLORES INTO THE WFO HANFORD WARNING/FORECAST AREA. DESPITE LESS CLOUDS THAN ORIGINALLY ANTICIPATED...HIGH TEMPERATURES SUNDAY IN THE CENTRAL AND SOUTHERN SAN JOAQUIN VALLEY WERE WELL BELOW NORMAL...IN THE UPPER 80S TO LOWER 90S. TEMPERATURES EARLY THIS MORNING WERE RUNNING SIMILAR TO EARLY SUNDAY MORNING...SO SHOULD SEE ANOTHER DAY WITH BELOW-NORMAL HIGHS. ALTHOUGH CONVECTION HAS TEMPORARILY CEASED OVER THE CENTRAL CALIFORNIA INTERIOR...THE MODELS KEEP ABUNDANT MID-LEVEL MOISTURE OVER AT LEAST THE SOUTHERN HALF OF THE WFO HANFORD WARNING/FORECAST AREA. OF INTEREST IS THAT BOTH THE NAM-12 AND THE HRRR HAVE LIMITED MOISTURE OVER MERCED AND MARIPOSA COUNTIES TODAY...WITH THE NAM-12 FINALLY BRINGING THE MOISTURE NORTHWARD THIS EVENING AS KERN COUNTY BEGINS TO DRY OUT. IF THIS VERIFIES...CONVECTION COULD CONTINUE OVER MUCH OF THE REGION NORTH OF KERN COUNTY OVERNIGHT RATHER THAN BEING CONFINED MAINLY TO THE SOUTHERN SIERRA NEVADA AFTER MIDNIGHT. SUNDAY MORNING/S RFC QPF GUIDANCE FOR INTERIOR CENTRAL CALIFORNIA CONTINUED A TREND OF BEING WETTER WITH EACH SUCCESSIVE RUN. THE RFC STORM-TOTAL QPF FOR THE SOUTHERN SIERRA NEVADA FORECAST POINTS WAS OVER AN INCH THROUGH TUESDAY MORNING. FURTHER SOUTH...ALTHOUGH THERE ARE NO FORECAST POINTS...THE GROUND IS SATURATED FROM SUNDAY/S RAIN SO THERE LIKELY WILL BE FLOODING FROM EXCESSIVE RUNOFF. WILL KEEP THE FLASH FLOOD WATCH FOR THE MOUNTAIN AND DESERT AREAS IN PLACE THROUGH THIS EVENING. AS THE TROUGH DROPS THROUGH THE PACIFIC NORTHWEST AND INTO CENTRAL CALIFORNIA THE SOUTHWEST FLOW ALOFT WILL STRENGTHEN AND BEGIN DRYING OUT THE REGION BEGINNING WEDNESDAY. IN TURN...THE RIDGE IS FORECAST TO BUILD BACK INTO CALIFORNIA WITH THE 500-MB 5880-METER HEIGHT LINE PUSHING NORTH OF THE WFO HANFORD WARNING/FORECAST AREA BY FRIDAY. && .AVIATION... SCATTERED THUNDERSTORM ACTIVITY WILL PERSIST ACROSS THE MOUNTAIN AND DESERT AREAS OF CENTRAL CALIFORNIA...WITH ISOLATED THUNDERSTORMS ALSO POSSIBLE IN THE SAN JOAQUIN VALLEY OVER THE NEXT 24 HOURS. THESE STORMS WILL BRING AREAS OF MVFR AND LOCAL IFR/VLIFR CONDITIONS ALONG WITH WITH SOME POSSIBLE MOUNTAIN OBSCURATIONS IN THE HIGHER TERRAIN. GUSTY AND ERRATIC WINDS AROUND 40 KTS CAN ALSO ACCOMPANY THE STORMS. OTHERWISE...VFR CONDITIONS WILL PREVAIL OVER THE CENTRAL CALIFORNIA INTERIOR. && .AIR QUALITY ISSUES... NONE. && .CERTAINTY... THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH. THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM. THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD. CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL INFORMATION AND/OR TO PROVIDE FEEDBACK. && .CLIMATE... RECORDS SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR KFAT 07-20 111:1908 81:1973 78:1938 54:1903 KFAT 07-21 112:1908 79:1987 82:2006 56:1973 KFAT 07-22 112:2006 83:1896 84:2006 56:1903 KBFL 07-20 112:1938 84:1973 82:1979 49:1906 KBFL 07-21 112:1938 81:1987 83:1969 50:1906 KBFL 07-22 113:1908 82:1984 88:1910 50:1903 && .HNX WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE SOUTHERN SIERRA NEVADA FROM YOSEMITE NATIONAL PARK TO THE KERN COUNTY LINE /CAZ096-097/. FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE KERN COUNTY MOUNTAINS AND DESERT AND THE INDIAN WELLS VALLEY /CAZ095-098-099/. && $$ PUBLIC...SANGER AVN/FW...DURFEE SYNOPSIS...ANDERSEN WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
617 PM MDT TUE JUL 21 2015 .UPDATE... ISSUED AT 613 PM MDT TUE JUL 21 2015 UPDATED GRIDS/ZONES PER LATEST RADAR AND SAT TRENDS ALONG WITH HIGH RES PROGS. HRRR DEVELOPS ANOTHER ROUND OF SHOWERS/STORMS OVER THE NRN I-25 CORRIDOR LATER THIS EVE...AS A SECOND SHORTWAVE NOW MOVING THROUGH NWRN CO MOVES THROUGH. CANNOT DISCOUNT IT...ALTHOUGH MOST OF THE HEAVIER CONVECTION IS NOW E OF THE CORRIDOR...SO WILL MAINTAIN LOW POPS THROUGH LATE TONIGHT FOR THE PLAINS. ROSE && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 238 PM MDT TUE JUL 21 2015 CURRENTLY...SOMEWHAT FLAT UPPER RIDGE OVER THE SOUTHERN U.S TODAY...WHILE AN UPPER SHORTWAVE WAS CROSSING WY. THE DAY STARTED OFF MOSTLY CLOUDY FOR MOST AREAS AND MT CONVECTION WAS SLOW TO INITIATE. A LITTLE BIT OF CLEARING...AND FORTUITOUS TIMING OF THE UPPER SHORTWAVE...HAS NOW KICKED SHOWERS AND STORMS OFF OVER THE HIGHER TERRAIN AND ADJACENT PLAINS. HI RES MODELS HAVE HAD A VERY DIFFICULT TIME TRYING TO GET A HANDLE ON ACTUAL ONGOING WX...SO THE SHORT TERM FORECAST HAS BEEN A LITTLE CHALLENGING. TEMPS HAVE WARMED INTO THE 70S AND 80S FOR MOST LOCATIONS. TONIGHT...BANDS OF CONVECTION...LIKELY TIED TO THE UPPER SHORTWAVE TO THE NORTH...WILL CONTINUE ACROSS THE FORECAST AREA THIS EVE UNTIL THE 04Z-06Z TIME FRAME. STORMS HAVE BEEN MOVING...SO NO WORD OF ANY FLOODING ISSUES SO FAR AND STORMS HAVE BEEN AVOIDING AREA BURN SCARS...SO FAR. SPC HAS PAINTED MUCH OF THE E PLAINS IN THE MARGINAL AREA....SO THERE IS STILL THE POSSIBILITY OF A STRONG TO SEVERE STORM ACROSS THE PLAINS THIS EVE PRODUCING DAMAGING WINDS AND HAIL AROUND 1 INCH. THE UPPER WAVE WILL CONTINUE EAST TONIGHT...AND CONVECTION IS FORECAST TO DIMINISH LATE FROM WEST TO EAST AND TAPER OFF OVERNIGHT. TOMORROW...MODELS INDICATE THAT THE UPPER RIDGE WILL START TO STRENGTHEN AND BUILD INTO COLORADO...SHUNTING AVAILABLE MOISTURE EITHER FAR NORTH...OR WELL SOUTH. THERE WILL STILL BE THE ISOLATED SHOT AT MT CONVECTION STARTING MIDDAY...BUT FOR THE MOST PART THIS LOOKS LIKE THE START TO A WARM AND ESSENTIALLY DRY PERIOD INTO THE WEEKEND. LOOK FOR MAX TEMPS IN THE 80S TO LOWER 90S FOR THE E PLAINS...AND 80S FOR THE HIGH VALLEYS. MOORE .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 238 PM MDT TUE JUL 21 2015 MODEST SOUTHWEST FLOW ALOFT WILL CONTINUE OVER THE REGION DURING THIS FORECAST TIME PERIOD. GUIDANCE INDICATES THAT AREAS ALONG AND WEST OF THE CONTDVD WILL LIKELY SEE LESS STORMS OVERALL AS DRIER AIR IS FORECAST TO IMPINGE OVER THIS REGION DURING MOST OF THE PERIOD...SO THE BEST CHANCE OF STORMS WILL LIKELY BE ALONG THE MOUNTAINS/PLAINS INTERFACE...IE...THE PIKES PEAK REGION...WETS AND SANGRE DE CRISTO MOUNTAINS. WITH NO SIGNIFICANT SURGE OF MOISTURE NOTED IN THE GUIDANCE AND ONLY MODEST WEAK BOUNDARIES MOVING ACROSS THE PLAINS...THE POPS OVER THE MTNS/PLAINS INTERFACE WILL BE IN THE ISOLD TO LOW SCATTERED CATEGORY...WITH MAINLY ISOLD POPS OVER THE PLAINS. THE OVERALL BEST CHANCE OF PRECIP WILL BE OVER THE WEEKEND. MAX TEMPS THROUGH THE PERIOD WILL GENERALLY BE IN THE L/M90S ACROSS MOST OF THE PLAINS...WITH 70S AND 80S OVER THE VALLEYS. /HODANISH && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 238 PM MDT TUE JUL 21 2015 PLENTY OF MOISTURE IN PLACE TO CONTINUE WIDESPREAD CONVECTION OVER AND NEAR THE HIGHER TERRAIN THIS EVE. STORMS THAT DEVELOP MAY PRODUCE PERIODS OF LOCALLY HEAVY RAINFALL AND MVFR TO IFR CONDITIONS AT TERMINALS. COULD ALSO SEE STRONG TO SEVERE STORMS ALONG THE I25 CORRIDOR AND PORTIONS OF THE E PLAINS THROUGH THIS EVENING. LARGE HAIL TO AROUND AN INCH IN DIAMETER AND GUSTY OUTFLOW WINDS TO AROUND 60 MPH WILL BE POSSIBLE FOR KCOS SOUTH TO KTAD...AND EAST TO KLHX....THROUGH APPROXIMATELY 04Z. STORMS ARE EXPECTED TO DIMINISH FROM WEST TO EAST THROUGH THE EVENING HOURS. VFR CONDITIONS EXPECTED ALL AREAS FOR WED. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ROSE SHORT TERM...MOORE LONG TERM...HODANISH AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
325 PM MDT MON JUL 20 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 243 PM MDT MON JUL 20 2015 CURRENTLY...A HEALTHY AMOUNT OF CLOUD COVER THROUGH MUCH OF THE DAY HAS PUT A DAMPER ON MUCH OF THE POTENTIAL ACTIVITY FOR TODAY...AND CONVECTION CURRENTLY OVER THE HIGHER TERRAIN WAS SLOW TO START. NO REPORTS OF HEAVY RAINFALL AS OF YET...AS SOUNDINGS THIS MORNING CONFIRMED THAT THE GREATER AMOUNT OF MOISTURE IS AVAILABLE IN NM. TEMPS HAVE WARMED INTO THE UPPER 70S TO UPPER 80S ACROSS THE PLAINS AS OF 3 PM...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS. SFC WINDS ACROSS THE PLAINS HAVE BEEN GENERALLY OUR OF THE EAST...BUT WITHIN THE PAST COUPLE OF HOURS HAVE SHIFTED TO A MORE S-SE DIRECTION. TONIGHT...A FLAT RIDGE OF HIGH PRESSURE OVER THE SOUTHERN U.S. WILL STAY THAT WAY FOR ANOTHER DAY OR SO...AS A COUPLE OF UPPER DISTURBANCES CROSS THE GREAT BASIN AND NORTHERN ROCKIES. HI RES MODELS INCLUDING THE HRRR INDICATE THAT THE CURRENT ACTIVITY WILL CONTINUE WELL INTO THE NIGHT...WITH SOME SPILL OVER ACROSS THE I25 CORRIDOR THIS EVENING BETWEEN 22Z AND 06Z. OTHERWISE...FEEL THAT ACTIVITY WILL BE MAINLY TIED TO THE MTS. SO...NOT A LOT OF IMPRESSIVE STORMS JUST YET AND THE UPPER W-SW FLOW HAS BEEN KEEPING STORMS MOVING...CUTTING DOWN ON THE FLASH FLOOD THREAT. PRECIPITABLE WATER AMOUNTS SOUTH OF THE STATE LINE IN NM ARE WELL OVER AN INCH...BUT UP NORTH IN THE PUB CWA ARE CLOSER TO .6 TO .7 OF AN INCH. OF COURSE...THE THREAT OF FLASH FLOODING FOR AREA BURN SCARS REMAINS THIS EVE AND WILL HAVE TO BE MONITORED. TOMORROW...THE ACTIVE PATTERN CONTINUES AS A SHORTWAVE CROSSES WY...PROVIDING THE TRIGGER FOR A RAPID INCREASE IN CONVECTION OVER ALL OF THE MTS AND ADJACENT PLAINS BY 15Z. AS THIS WAVE CONTINUE EAST...THE BAND OF ENHANCED LIFT WILL CROSS THE I25 CORRIDOR AND E PLAINS THROUGH THE AFTN HRS...AND AN ATTEMPT HAS BEEN MADE IN THE POP GRIDS TO SHOW THIS. STRONG TO SEVERE STORMS WILL ALSO BE A POSSIBILITY TOMORROW AFTN AS THIS WAVE CROSSES THE AREA...AS THERE WILL BE PLENTY OF MOISTURE AND SHEAR ON TAP...AND SPC HAS PAINTED MUCH OF THE E PLAINS IN THE MARGINAL AREA. MAX TEMPS TOMORROW MAY BE A DEGREE OR TWO COOLER...BUT SHOULD STILL WARM INTO THE 70S AND 80S FOR THE PLAINS...60S AND 70S FOR THE HIGH VALLEYS. MOORE .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 243 PM MDT MON JUL 20 2015 TUESDAY NIGHT... AN AREA OF SHOWERS AND STORMS WILL LIKELY BE MOVING ACROSS THE EASTERN PLAINS AS A DISTURBANCE OVER THE REGION CONTINUES TO MOVE EAST. LOCALLY HEAVY RAIN WILL BE POSSIBLE AND STRONG TO MARGINALLY SVR STORMS WILL BE POSSIBLE GIVEN THE MODEST CAPE AND SHEAR THAT WILL BE OVER THE PLAINS. WEDNESDAY THROUGH FRIDAY... OVERALL IT WILL BE DRY AND WARM AS MONSOON TAP WILL BE DECREASED AS HEIGHTS RISE ACROSS THE REGION. MAX TEMPS OVER THE PLAINS WILL RISE BACK UP INTO THE 90S. WE WILL STILL SEE SOME ISOLD TSRA ACROSS THE REGION...BUT OVERALL COVERAGE WILL BE LESS THAN THE LAST FEW DAYS. SATURDAY INTO MONDAY.. GUIDANCE INDICATES MONSOON MOISTURE WILL ONCE AGAIN BE ON THE UPSWING AS SW FLOW CONTINUES ALOFT AND A TROUGH TO OUR WEST MOVES TOWARDS THE REGION. TEMPS WILL COOL SLIGHTLY AND SHOWERS AND STORMS SHOULD INCREASE DURING THE AFTERNOON AND EVENING TIME PERIODS. /HODANISH && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING) ISSUED AT 243 PM MDT MON JUL 20 2015 CONVECTION IS EXPECTED TO CONTINUE ACROSS THE HIGHER TERRAIN THIS EVE...BUT SFC WINDS SHIFTING TO A MORE S-SE DIRECTION THIS AFTN WILL ALLOW A FEW OF THE STORMS TO CROSS THE I25 CORRIDOR. THEREFORE...AN ISOLATED STORM PROBABLE FOR KCOS OR KPUB...BUT MORE SO OUTFLOW WINDS. KALS WILL HAVE A BETTER CHANCE FOR SHOWER AND STORM ACTIVITY IN THE VCNTY THROUGH 07Z. LOOK FOR VFR CONDITIONS OVER THE NEXT 24 HRS FOR MUCH OF THE AREA...WITH MVFR TO IFR CONDITIONS AT TIMES OVER THE MT PASSES ASSOCIATED WITH STRONGER STORMS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...MOORE LONG TERM...HODANISH AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS TAUNTON MA
824 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT SWEEPS ACROSS NEW ENGLAND THIS EVENING AND OVERNIGHT... POSSIBLY ACCOMPANIED BY SCATTERED SHOWERS AND THUNDERSTORMS. BEHIND THE FRONT WED AND THU...A MUCH LESS HUMID AIRMASS OVERSPREADS SOUTHERN NEW ENGLAND. A REINFORCING SURGE OF DRIER AIR ARRIVES FRIDAY INTO SATURDAY. PERIODS OF SHOWERY WEATHER LOOKS TO RETURN SOMETIME SUNDAY INTO MONDAY AS A LOW PRESSURE MOVES ACROSS EASTERN CANADA. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 823 PM UPDATE... CONVECTION MOVING EAST ACROSS NORTHERN CT WAS SUPPORTED BY STEEP 0-3 KM LAPSE RATES...WITH MODEST MEAN-LAYER CAPE VALUES OF 500-1000 J/KG. EFFECTIVE BULK SHEAR WAS 40-45 KT. THUS FAR THIS HAS MANIFESTED ITSELF IN WIND GUSTS OF 39 KT AT KHFD. NOW THAT SUNSET HAS PASSED...EXPECTATIONS ARE FOR ANY THUNDERSTORMS TO WEAKEN AS THIS EVENING PROGRESSES. THE MAIN THREATS OF ANY THUNDERSTORMS WOULD BE LIGHTNING AND BRIEF HEAVY RAINFALL. LATEST INDICATIONS ARE FOR RAINFALL CHANCES TO BE FOCUSED SOUTH OF THE MASS PIKE/I-90 FOR THE REST OF TONIGHT. INTERESTINGLY...A FEW RUNS OF THE HRRR INDICATED AN INCREASED RISK FOR SHOWERS AROUND MIDNIGHT ACROSS THE COASTAL PLAIN OF SOUTHEAST MA AND SOUTHERN RI. PRESUMABLY THIS WOULD BE ALONG THE COLD FRONT AS IT MAKES ITS FINAL PUSH OFFSHORE. THIS COLD FRONT AS LOCATED OVER EASTERN NY STATE AT 8 PM. TWEAKED TIMING AND LOCATION OF RAINFALL CHANCES THIS EVENING. ALSO TWEAKED TEMPERATURES...DEW POINTS AND WINDS. PREVIOUS DISCUSSION... FULL SUNSHINE ACROSS MOST OF THE AREA WITH THE EXCEPTION ALONG THE SOUTH COAST INCLUDING CAPE COD WHERE MID/HIGH CLOUDS ARE SLOW TO DEPARTURE. SUNSHINE HAS ALLOWED TEMPS AT 3 PM TO CLIMB INTO THE MU80S INLAND...U70S TO L80S ALONG THE COAST GIVEN SEABREEZES. DESPITE WARM SURFACE READINGS MID LEVEL REMAIN SOMEWHAT WARM WITH -8C AT 500 MB. THIS IS ONLY POOR MID LEVEL LAPSE RATES OF AROUND 5.5C/KM. SO DESPITE SBCAPES 1000-2000 J/KG ALONG AND AHEAD OF BROKEN LINE OF CONVECTION IN EASTERN NY...UPDRAFTS WEAKEN ALOFT GIVEN POOR MID LEVEL LAPSE RATES. DEEP LAYER SHEAR /40 KT/ AND SYNOPTIC SCALE FORCING /Q-VECTOR CONVERGENCE/ IS FAIRLY ROBUST ASSOCIATED WITH SHORT WAVE TROUGH AND ATTENDING COLD FRONT...SO EXPECT BROKEN LINE OF CONVECTION TO SURVIVE INTO SOUTHERN NEW ENGLAND LATER THIS EVENING 5 PM TO 8 PM...EXCEPT 8 PM TO 11 PM RI AND EASTERN MA AND POSSIBLY NOT TIL 11 PM TO 2 AM ACROSS CAPE COD AND THE ISLANDS. GIVEN THE LACK OF DEEP LAYER INSTABILITY AND CONVECTION ARRIVING AFTER SUNSET FOR MOST OF THE AREA...NOT EXPECTING SEVERE WEATHER. MAIN HAZARDS WOULD BE GUSTY WINDS AND BRIEF HEAVY DOWNPOURS. OTHERWISE EXPECT A WARM AND MUGGY EVENING. SECOND HALF OF THE NIGHT POST FRONTAL AIRMASS OVERSPREADS THE REGION WITH DEW PTS FALLING INTO THE 50S TOWARD MORNING FROM WEST TO EAST. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... WEDNESDAY... COLUMN DRIES NICELY ESPECIALLY DURING THE AFTERNOON BEHIND DEPARTING SECONDARY SHORT WAVE TROUGH. FLOW REMAINS CYCLONIC WITH COOL AIR ALOFT YIELDING DIURNAL CU/SCU ESPECIALLY ACROSS NORTHERN MA INTO NH. SUFFICIENT MID LEVEL SUBSIDENCE AND ASSOCIATED DRY AIR ALOFT TO PRECLUDE CU/SCU FROM DEVELOPING INTO TCU. THUS EXPECTING DRY WEATHER TO PRECLUDE. VERY COMFORTABLE WITH DEW PTS IN THE 50S AND A MODEST WNW BREEZE. ALTHOUGH PGRADIENT MAY RELAX ENOUGH TO PROMOTE AN AFTERNOON SEABREEZE ALONG THE EASTERN MA COASTLINE. HIGHS MAINLY 80-85. A REAL NICE DAY BY LATE JULY STANDARDS. WED NIGHT... CORE OF COOLER/DRIER AIR SETTLES OVER THE REGION WITH 850 AND 925 MB TEMPS ANOMALIES FALLING TO -1 STD BELOW CLIMO. THUS LEANED TOWARD THE COOLER MOS TEMPS WITH LOWS IN THE 50S MOST LOCATIONS GIVEN DRY AIRMASS/MOSTLY CLEAR SKIES AND MANY LOCATIONS DECOUPLING FOR A TIME. && .LONG TERM /THURSDAY THROUGH TUESDAY/... HIGHLIGHTS... * MAINLY DRY WITH BELOW NORMAL TEMPERATURES THE REST OF THIS WEEK * A SPOT SHOWER OR TWO IS POSSIBLE FRIDAY * WET WEATHER CHANCES INCREASE SUNDAY INTO MONDAY * MODERATING TEMPERATURES NEXT WEEK OVERVIEW... 21/12Z GUIDANCE REMAINS IN GOOD OVERALL AGREEMENT FOR THE MAJORITY OF THIS PORTION OF THE FORECAST. THERE ARE THE TYPICAL MINOR TIMING AND AMPLITUDE DIFFERENCES LATE THIS WEEKEND INTO EARLY NEXT WEEK. WHILE THE DETAILS MAY CHANGE...HAVE MODERATE CONFIDENCE IN THE OVERALL TREND OF THIS FORECAST. PREFERRED THE CONSENSUS BLEND TO SMOOTH OVER THESE DIFFERENCES. OVERALL TREND IS FOR A MID LEVEL LOW OVER EASTERN CANADA TO MOVE OFFSHORE LATE THIS WEEKEND...WITH ANOTHER MID LEVEL TROUGH TO ARRIVE EARLY NEXT WEEK. OTHER THAN A WARM FRONT/COLD FRONT COMBINATION SUNDAY INTO MONDAY LASTLY LOOKING AT THE 850 MB AND THE 925 MB TEMPS...HAVE A HIGH CONFIDENCE THAT TEMPS WILL BE BELOW NORMAL FOR THE REST OF THE WEEK AND INTO THE FIRST HALF OF THE WEEKEND. DAILIES... THURSDAY INTO SATURDAY...HIGH CONFIDENCE. HIGH PRESSURE WILL TAKE HOLD WEST OF THE REGION THURSDAY. HAVE HIGH CONFIDENCE THAT THURSDAY WILL BE DRY. POTENT SHORTWAVE WILL MOVE THROUGH THE FLOW ON FRIDAY...BELIEVE THIS WILL TRIGGER A FEW SCATTERED SHOWERS AND THUNDERSTORMS. GREATEST CHANCE IS ACROSS THE EASTERN HALF OF SOUTHERN NEW ENGLAND WHERE MORE INTERACTION WITH SEABREEZES ARE LIKELY. STILL LOW CONFIDENCE FOR STRONG TO SEVERE STORMS...AS ENERGY IS MINIMAL WITH SHEAR REMAINING ABOUT 40 KTS. ON THE BACK SIDE OF THIS SHORTWAVE...SUBSIDENCE WILL TAKE HOLD AND SHOULD KEEP SATURDAY RAIN-FREE. HOWEVER A GOOD AMOUNT OF CLOUD COVER COULD STILL BE AROUND AS LAPSE RATES STEEPENED AND MOISTURE IN THE MID-LEVELS INCREASES FROM SW FLOW. OVERALL SHOULD BE DRY FOR MUCH OF THIS PERIOD. TEMPERATURES WILL ALSO BE BELOW AVERAGE WITH LOW HUMIDITY THANKS TO THE DOMINANT NW FLOW ALOFT. SUNDAY AND MONDAY...LOW CONFIDENCE. THE MAIN ISSUE HERE IS TIMING. THE AFTERNOON AND EVENING HOURS ARE CLIMATOLOGICALLY FAVORED FOR SHOWERS AND THUNDERSTORMS. HOWEVER... THERE IS ENOUGH VARIATION IN THE GUIDANCE TO NOT GET THAT SPECIFIC AT THIS POINT. TUESDAY...MODERATE CONFIDENCE. HIGH PRESSURE SHOULD RETURN TO SOUTHERN NEW ENGLAND. HAVE MODERATE CONFIDENCE IN THE TREND FOR DRIER WEATHER...WITH LOWER CONFIDENCE IN THE SPECIFIC TIMING. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT-TERM /THROUGH WEDNESDAY NIGHT/... TONIGHT...MAINLY VFR. BRIEF MVFR IN SCATTERED SHOWERS/T-STORMS THROUGH ABOUT 05Z. ISOLATED IFR POSSIBLE ACROSS CAPE COD AND ISLANDS...ESPECIALLY KACK. IMPROVING TO VFR FROM WEST TO EAST BETWEEN 03Z TO 09Z. WEDNESDAY...VFR WITH A MODEST WNW WIND INLAND...POSSIBLE AFTERNOON SEABREEZE ALONG EASTERN MA COASTLINE. WEDNESDAY NIGHT...OTHER THAN A SPOT SHOWER/MVFR ALONG THE MA/NH BORDER DURING THE EVENING...VFR PREVAILS ALONG WITH DRY WEATHER. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SOME UNCERTAINTY ON EXACT TIMING OF ARRIVAL AND DEPARTURE OF SHOWERS/T-STORMS THIS EVENING. POSSIBLE AFTERNOON SEABREEZE WED AFTN. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. SOME UNCERTAINTY ON EXACT TIMING OF ARRIVAL AND DEPARTURE OF SHOWERS/T-STORMS THIS EVENING. OUTLOOK...THURSDAY THROUGH SUNDAY... THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR. MAY SEE SOME MVFR CIGS IN -SHRA ON FRIDAY...ESPECIALLY EASTERN TERMINALS. SEA BREEZES COULD DEVELOP EVERY DAY IN THIS PERIOD. SUNDAY...MODERATE CONFIDENCE. MAINLY VFR. INCREASING AREAS OF MVFR IN SHOWERS AND ISOLATED TSRA. GREATEST RISK FOR TSRA ACROSS THE WESTERN HALF OF SOUTHERN NEW ENGLAND PRIOR TO 00Z MONDAY. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE. TONIGHT...A FEW SHOWERS/T-STORMS POSSIBLE ALONG AND AHEAD OF COLD FRONT. WIND SHIFT FROM SSW TO WNW FROM WEST TO EAST LATE THIS EVENING INTO THE OVERNIGHT. WEDNESDAY...FINE BOATING WEATHER WITH WNW WIND POSSIBLE BECOMING ONSHORE ESP EASTERN MA COASTLINE. COMBINATION OF WNW WIND WAVES AND SSE OFFSHORE SWELL MAY YIELD SEAS INCREASING TO NEAR 5 FT OFFSHORE WATERS WED AFTN. MAY NEED A SMALL CRAFT ADVISORY FOR SEAS BUT CONFIDENCE TOO LOW AT THIS TIME. WED NIGHT...ANY SEABREEZES DECAY AND GIVE WAY TO WNW WINDS OVERNIGHT. DRY WEATHER AND GOOD VSBY. OUTLOOK...THURSDAY THROUGH SUNDAY... HIGH CONFIDENCE FOR RELATIVELY LIGHT WINDS AND SEAS THROUGH THIS PERIOD. LOW CONFIDENCE FOR SHOWERS FRIDAY ACROSS THE NEARSHORE WATERS FRIDAY. MODERATE CONFIDENCE FOR SHOWERS LATE SUNDAY INTO SUNDAY NIGHT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...BELK/NOCERA NEAR TERM...BELK/NOCERA SHORT TERM...NOCERA LONG TERM...BELK AVIATION...BELK/NOCERA MARINE...BELK/NOCERA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
154 PM EDT MON JUL 20 2015 .SYNOPSIS... A SURFACE TROUGH WILL SET UP OVER THE AREA TODAY. A COLD FRONT WILL APPROACH ON TUESDAY...AND MOVE THROUGH TUESDAY EVENING. HIGH PRESSURE WILL THEN BUILD IN FROM WEDNESDAY THROUGH FRIDAY...MOVING OFF THE COAST SATURDAY. A WEAK COLD FRONT APPROACHES SATURDAY NIGHT AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... TEMPERATURES CONTINUE TO WARM INTO THE LOWER AND MIDDLE 90S. THE WARMEST LOCATIONS ACROSS THE CWA AT NOON ARE ACROSS LONG ISLAND. THE ISLIP MACARTHUR AIRPORT HAS REACHED 92 DEGREES AS OF NOON...WHICH IS THE FIRST TIME SINCE JULY 20TH 2013 THAT THE TEMPS HAS REACHED 90 OR HIGHER AT THIS LOCATION. TEMPS ARE IN THE UPPER 80S AND LOWER 90S ELSEWHERE. HEAT INDICES ARE HIGHEST ACROSS LONG ISLAND AND COASTAL CONNECTICUT...IN THE MIDDLE AND UPPER 90S. DEW POINTS ARE IN THE MIDDLE 60S ACROSS THE NYC AND NJ METRO SO HEAT INDICES ARE IN THE LOWER TO MIDDLE 90S. HAVE ADJUSTED HOURLY TEMPS TO BETTER REFLECT THE LATEST OBSERVATIONAL TRENDS. THIS CONTINUES TO GIVE HIGHS IN THE LOWER TO MIDDLE 90S. MAX HEAT INDICES WILL BE IN THE UPPER 90S FOR THE NYC METRO AND NEAR 100 ACROSS NE NJ. SURFACE TROUGH IS BEGINNING TO REDEVELOP ACROSS THE NYC METRO. SEA BREEZES HAVE ALSO DEVELOPS ACROSS THE SOUTH SHORE OF LONG ISLAND AND COASTAL CT. THESE SEA BREEZES WILL SLOWLY MOVE INLAND THROUGH THE AFTERNOON. THE LATEST RAP AND HRRR MODELS CONTINUE TO BRING THIS BOUNDARY THROUGH THE NYC METRO LATE THIS AFTERNOON. IT IS POSSIBLE THIS IS OVERDONE. HOWEVER...IF IT DOES MOVE THROUGH...DEW POINTS COULD BOUNCE BACK UP INTO THE LOWER 70S. SO FAR...NO CONVECTION HAS DEVELOPED ON THE SEA BREEZE CONVERGENCE. STILL FEEL THAT THIS CONVERGENCE IS THE ONLY FOCUS FOR ANY CONVECTIVE DEVELOPMENT. INSTABILITY IS VERY HIGH...2000 TO 3000 J/KG TODAY. ANY STRONGER CELL COULD PRODUCE STRONG WIND GUSTS WITH INVERTED V SOUNDINGS INDICATED BY BUFKIT. && .SHORT TERM /TUESDAY/... A COLD FRONT CURRENTLY OVER THE NRN PLAINS WILL APPROACH...BUT THE FEATURE APPEARS TO HAVE SLOWED SOMEWHAT FROM PREVIOUS PROGS. THIS COULD RESULT IN A COMPLETELY DRY DAY ACROSS THE CWA. HAVE TRIMMED BACK POPS TO SCHC AS A RESULT...KEEPING IN MIND THAT THERE MAY BE SOME RESIDUAL BOUNDARIES IN THE AREA. HOT TEMPS BUT THE HX ATTM BLW 95 IN THE CITY. THE ADVY WAS THEREFORE NOT EXTENDED. TEMPS DO HAVE A TENDENCY TO RISE HIGHER THAN MODEL GUIDANCE AHEAD OF A COLD FRONT...SO THIS WILL NEED TO BE WATCHED. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... BROAD UPPER TROUGH AND ASSOCIATED CLOSED LOW ACROSS EASTERN CANADA MOVES SLOWLY EAST TUESDAY INTO TUESDAY NIGHT. A WEAK SHORTWAVE ROTATES THROUGH THE TROUGH AND EAST OF THE REGION BY LATER TUESDAY NIGHT. THE SHORTWAVE WILL BE ACCOMPANIED BY A WEAK COLD FRONT. SCATTERED CONVECTION WILL BE POSSIBLE WITH THE FRONT. TIMING OF THE COLD FRONT IS CONSISTENT AMONG THE GUIDANCE. HOWEVER...GUIDANCE BRINGS THE FRONT THROUGH MAINLY DRY TUESDAY EVENING. WILL HAVE JUST SLIGHT CHANCE POPS AT THIS TIME. HIGH PRESSURE BUILDS IN SLOWLY FROM THE WEST TUESDAY NIGHT INTO SATURDAY WITH A HIGHLY AMPLIFIES UPPER FLOW AS A RIDGE BUILDS INTO THE CENTRAL UNITED STATES AND CANADA WITH A PACIFIC NORTHWEST TROUGH AND THE EASTERN CANADIAN TROUGH. THE UPPER RIDGE WEAKENS BY THE WEEKEND WITH THE UPPER TROUGH SHIFTING OFF THE CANADIAN MARITIME AND NORTHEAST COAST. THIS ALLOWS A NORTHERN STREAM SHORTWAVE TO MOVE NORTH OF THE REGION SATURDAY NIGHT INTO SUNDAY. A WEAKENING COLD FRONT MOVES SLOWLY INTO THE AREA FOR SUNDAY. NEXT CHANCE OF PRECIPITATION WILL BE SUNDAY NIGHT INTO NEXT MONDAY AND WILL HAVE LOW CHANCE POPS AT THIS TIME. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... A TROUGH OF LOW PRESSURE WILL REMAIN NEARLY STATIONARY ACROSS THE AREA THROUGH EARLY TONIGHT. A COLD FRONT WILL APPROACH ON TUESDAY PASSING EAST OF THE AREA TUESDAY NIGHT. PREVAILING WEATHER WILL BE VFR. TEMPO MVFR IN CIGS AND VSBY POSSIBLE IN AFTN AND EVE ISOLATED TO SCT TSTMS EACH DAY. CONFIDENCE IS TOO LOW TO INCLUDE IN TAFS. WINDS...THE SEA BREEZE FRONT BETWEEN KJFK AND KLGA EXTENDING EAST ACROSS CENTRAL LONG ISLAND WILL STRUGGLE NORTH AND WEST. SW WINDS ARND 10 KT ARE FCST ARND 19Z KLGA. HOWEVER...WINDS WILL REMAIN MAINLY W ACROSS METRO NJ AND THE LOWER HUDSON VALLEY LESS THAN 10 KT. WINDS WILL BECOME LIGHT AND VARIABLE AFT SUNSET. SW WINDS ARE FCST TO DEVELOP BETWEEN 15Z AND 18Z ARND 10 KT ON TUE. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTMS 18Z- 00Z. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR LATER DEVELOPMENT OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTM 18Z- 00Z. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTM 18Z- 00Z. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTM 18Z- 00Z. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR ISOLATED TSTM 18Z- 00Z. .OUTLOOK FOR 00Z TUESDAY AFTN THROUGH SATURDAY... .TUE AFTN AND EVE...POSSIBLE MVFR IN ISOLATED-SCT TSTMS. .WED-SAT...VFR. && .MARINE... NO CHANGES AT THIS TIME. DUE TO A WEAK PRES GRAD OVER THE WATERS...WINDS AND SEAS BLW SCA LVLS THRU TUE. A COLD FRONT MOVES ACROSS THE FORECAST WATERS TUESDAY EVENING. HIGH PRESSURE BUILDS SLOWLY EAST TUESDAY NIGHT THROUGH THURSDAY AND MOVES OVER THE WATERS FRIDAY. WIND AND SEAS REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT THROUGH FRIDAY. && .HYDROLOGY... ANY TSTMS THAT DEVELOP TODAY WILL BE SLOW MOVING. AS A RESULT...THERE IS AN ISOLD FLASH FLOOD THREAT. NO SIGNIFICANT PRECIPITATION EXPECTED TUESDAY AND TUESDAY EVENING. DRY FROM TUESDAY NIGHT THROUGH FRIDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176- 178. NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ004-006- 103>108. MARINE...NONE. && $$ SYNOPSIS...JMC/MET NEAR TERM...DS SHORT TERM...JMC LONG TERM...MET AVIATION...GC MARINE...JMC/MET HYDROLOGY...JMC/MET
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1234 PM EDT MON JUL 20 2015 .SYNOPSIS... A SURFACE TROUGH WILL SET UP OVER THE AREA TODAY. A COLD FRONT WILL APPROACH ON TUESDAY...AND MOVE THROUGH TUESDAY EVENING. HIGH PRESSURE WILL THEN BUILD IN FROM WEDNESDAY THROUGH FRIDAY...MOVING OFF THE COAST SATURDAY. A WEAK COLD FRONT APPROACHES SATURDAY NIGHT AND SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... TEMPERATURES CONTINUE TO WARM INTO THE LOWER AND MIDDLE 90S. THE WARMEST LOCATIONS ACROSS THE CWA AT NOON ARE ACROSS LONG ISLAND. THE ISLIP MACARTHUR AIRPORT HAS REACHED 92 DEGREES AS OF NOON...WHICH IS THE FIRST TIME SINCE JULY 20TH 2013 THAT THE TEMPS HAS REACHED 90 OR HIGHER AT THIS LOCATION. TEMPS ARE IN THE UPPER 80S AND LOWER 90S ELSEWHERE. HEAT INDICES ARE HIGHEST ACROSS LONG ISLAND AND COASTAL CONNECTICUT...IN THE MIDDLE AND UPPER 90S. DEW POINTS ARE IN THE MIDDLE 60S ACROSS THE NYC AND NJ METRO SO HEAT INDICES ARE IN THE LOWER TO MIDDLE 90S. HAVE ADJUSTED HOURLY TEMPS TO BETTER REFLECT THE LATEST OBSERVATIONAL TRENDS. THIS CONTINUES TO GIVE HIGHS IN THE LOWER TO MIDDLE 90S. MAX HEAT INDICES WILL BE IN THE UPPER 90S FOR THE NYC METRO AND NEAR 100 ACROSS NE NJ. SURFACE TROUGH IS BEGINNING TO REDEVELOP ACROSS THE NYC METRO. SEA BREEZES HAVE ALSO DEVELOPS ACROSS THE SOUTH SHORE OF LONG ISLAND AND COASTAL CT. THESE SEA BREEZES WILL SLOWLY MOVE INLAND THROUGH THE AFTERNOON. THE LATEST RAP AND HRRR MODELS CONTINUE TO BRING THIS BOUNDARY THROUGH THE NYC METRO LATE THIS AFTERNOON. IT IS POSSIBLE THIS IS OVERDONE. HOWEVER...IF IT DOES MOVE THROUGH...DEW POINTS COULD BOUNCE BACK UP INTO THE LOWER 70S. SO FAR...NO CONVECTION HAS DEVELOPED ON THE SEA BREEZE CONVERGENCE. STILL FEEL THAT THIS CONVERGENCE IS THE ONLY FOCUS FOR ANY CONVECTIVE DEVELOPMENT. INSTABILITY IS VERY HIGH...2000 TO 3000 J/KG TODAY. ANY STRONGER CELL COULD PRODUCE STRONG WIND GUSTS WITH INVERTED V SOUNDINGS INDICATED BY BUFKIT. && .SHORT TERM /TUESDAY/... A COLD FRONT CURRENTLY OVER THE NRN PLAINS WILL APPROACH...BUT THE FEATURE APPEARS TO HAVE SLOWED SOMEWHAT FROM PREVIOUS PROGS. THIS COULD RESULT IN A COMPLETELY DRY DAY ACROSS THE CWA. HAVE TRIMMED BACK POPS TO SCHC AS A RESULT...KEEPING IN MIND THAT THERE MAY BE SOME RESIDUAL BOUNDARIES IN THE AREA. HOT TEMPS BUT THE HX ATTM BLW 95 IN THE CITY. THE ADVY WAS THEREFORE NOT EXTENDED. TEMPS DO HAVE A TENDENCY TO RISE HIGHER THAN MODEL GUIDANCE AHEAD OF A COLD FRONT...SO THIS WILL NEED TO BE WATCHED. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... BROAD UPPER TROUGH AND ASSOCIATED CLOSED LOW ACROSS EASTERN CANADA MOVES SLOWLY EAST TUESDAY INTO TUESDAY NIGHT. A WEAK SHORTWAVE ROTATES THROUGH THE TROUGH AND EAST OF THE REGION BY LATER TUESDAY NIGHT. THE SHORTWAVE WILL BE ACCOMPANIED BY A WEAK COLD FRONT. SCATTERED CONVECTION WILL BE POSSIBLE WITH THE FRONT. TIMING OF THE COLD FRONT IS CONSISTENT AMONG THE GUIDANCE. HOWEVER...GUIDANCE BRINGS THE FRONT THROUGH MAINLY DRY TUESDAY EVENING. WILL HAVE JUST SLIGHT CHANCE POPS AT THIS TIME. HIGH PRESSURE BUILDS IN SLOWLY FROM THE WEST TUESDAY NIGHT INTO SATURDAY WITH A HIGHLY AMPLIFIES UPPER FLOW AS A RIDGE BUILDS INTO THE CENTRAL UNITED STATES AND CANADA WITH A PACIFIC NORTHWEST TROUGH AND THE EASTERN CANADIAN TROUGH. THE UPPER RIDGE WEAKENS BY THE WEEKEND WITH THE UPPER TROUGH SHIFTING OFF THE CANADIAN MARITIME AND NORTHEAST COAST. THIS ALLOWS A NORTHERN STREAM SHORTWAVE TO MOVE NORTH OF THE REGION SATURDAY NIGHT INTO SUNDAY. A WEAKENING COLD FRONT MOVES SLOWLY INTO THE AREA FOR SUNDAY. NEXT CHANCE OF PRECIPITATION WILL BE SUNDAY NIGHT INTO NEXT MONDAY AND WILL HAVE LOW CHANCE POPS AT THIS TIME. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... A TROUGH OF LOW PRESSURE WILL REMAIN ACROSS THE AREA THROUGH EARLY TONIGHT. A COLD FRONT WILL APPROACH ON TUESDAY...AND MOVE THROUGH TUESDAY EVENING. PREVAILING WEATHER WILL BE VFR. TEMPO MVFR IN CIGS AND VSBY POSSIBLE IN AFTN AND EVE ISOLATED TO SCT TSTMS EACH DAY. CONFIDENCE IS TOO LOW TO INCLUDE IN TAFS. WINDS...TIMING THE DEVELOPMENT AND WESTWARD EXTENT OF SEA BREEZES ACROSS THE METRO AREA REMAINS UNCERTAIN. HIGHEST CONFIDENCE IS FROM KJFK AND KLGA EAST WITH SEA BREEZES DEVELOPING 16Z-18Z AT ARND 10 KT. SEA BREEZES MIGHT NOT REACH KEWR / KTEB AND KHPN. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH LATER DEVELOPMENT OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z. KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH LATER DEVELOPMENT OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z. KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR SEABREEZE WIND SHIFT. ISOLATED TSTM POSSIBLE 18Z-00Z. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH SEABREEZE WIND SHIFT. ISOLATED TSTM POSSIBLE 18Z-00Z. KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH LOW CHC OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z. KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE WITH LATER DEVELOPMENT OF SEABREEZE. ISOLATED TSTM POSSIBLE 18Z-00Z. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .MONDAY NIGHT-TUESDAY NIGHT...VFR. ISOLD-SCT SHRA/TSRA WITH LOCALLY MVFR CONDITIONS POSSIBLE...HOWEVER MOST PLACES MORE LIKELY TO NOT EXPERIENCE THAN TO EXPERIENCE ANY CONVECTION. .WEDNESDAY-THURSDAY...VFR. NW WINDS G15-20KT POSSIBLE. .THURSDAY NIGHT-FRIDAY...VFR. && .MARINE... NO CHANGES AT THIS TIME. DUE TO A WEAK PRES GRAD OVER THE WATERS...WINDS AND SEAS BLW SCA LVLS THRU TUE. A COLD FRONT MOVES ACROSS THE FORECAST WATERS TUESDAY EVENING. HIGH PRESSURE BUILDS SLOWLY EAST TUESDAY NIGHT THROUGH THURSDAY AND MOVES OVER THE WATERS FRIDAY. WIND AND SEAS REMAIN BELOW SMALL CRAFT LEVELS TUESDAY NIGHT THROUGH FRIDAY. && .HYDROLOGY... ANY TSTMS THAT DEVELOP TODAY WILL BE SLOW MOVING. AS A RESULT...THERE IS AN ISOLD FLASH FLOOD THREAT. NO SIGNIFICANT PRECIPITATION EXPECTED TUESDAY AND TUESDAY EVENING. DRY FROM TUESDAY NIGHT THROUGH FRIDAY. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ072>075-176- 178. NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ004-006- 103>108. MARINE...NONE. && $$ SYNOPSIS...JMC/MET NEAR TERM...DS SHORT TERM...JMC LONG TERM...MET AVIATION...GC MARINE...JMC/MET HYDROLOGY...JMC/MET
AREA FORECAST DISCUSSION
NWS ALBANY NY
415 AM EDT MON JUL 20 2015 .SYNOPSIS... A WEAK COLD FRONT WILL CONTINUE TO MOVE ACROSS THE REGION THIS MORNING AND SLOW ITS PROGRESS ONCE IT REACHES THE MID HUDSON VALLEY AND LITCHFIELD HILLS THIS AFTERNOON. THIS WILL RESULT IN ISOLATED THUNDERSTORMS INTO EARLY EVENING. OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REST OF THE REGION TODAY WITH CONTINUED VERY WARM TEMPERATURES BUT LOWER HUMIDITY LEVELS. THE HIGH WILL THEN SLIDE OFFSHORE TONIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION ON TUESDAY...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CANADA INTO THE GREAT LAKES WEDNESDAY...USHERING IN A COOLER AND DRIER AIR MASS INTO THE REGION FOR MID WEEK TO LATE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 415 AM EDT...A WIND SHIFT BOUNDARY IS CURRENTLY PUSHING EASTWARD ACROSS THE REGION...AS WINDS HAVE BECOME WESTERLY FOR AREAS WEST OF THE HUDSON RIVER VALLEY EARLY THIS MORNING. DEWPOINTS ARE STILL RATHER HIGH GENERALLY IN THE MID TO UPPER 60S...AS A SECONDARY DEWPOINT BOUNDARY IS LAGGING BACK TO THE NORTH AND WEST OF LAKE ONTARIO AT THIS HOUR. CONVECTION HAS WANED ACROSS OUR AREA...ALTHOUGH WE ARE WATCHING A SMALL CLUSTER OF SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHERN CENTRAL TIER OF NY MOVING EASTWARD ALONG THE TAIL END OF THE WIND SHIFT BOUNDARY ARCING BACK TO THE SOUTH AND WEST OF OUR REGION. HI- RES MODELS INCLUDING THE LOCAL WRF AND HRRR INDICATE THIS ACTIVITY SHOULD WEAKEN AS IT MOVES EAST WITH INSTABILITY WEAKENING. THE BOUNDARY WILL SHIFT SOUTHEASTWARD THROUGH THE DAY BUT SLOW ITS PROGRESS AS IT REACHES ULSTER...DUTCHESS AND LITCHFIELD COUNTIES. THE LINGERING BOUNDARY MAY BE ABLE TO PROVIDE ENOUGH LOW LEVEL CONVERGENCE FOR ISOLATED THUNDERSTORMS THIS AFTERNOON INTO EARLY EVENING FOR THIS LIMITED AREA. THERE SHOULD BE SUFFICIENT SURFACE HEATING ALONG WITH DEWPOINTS IN THE MID 60S TO RESULT IN SBCAPE VALUES IN THE 500-1000 J/KG RANGE. ELSEWHERE IT WILL BE DRY WITH GRADUALLY LOWERING HUMIDITY LEVELS. NOT MUCH OF A THERMAL GRADIENT ASSOCIATED WITH THE SURFACE BOUNDARY...SO TEMPERATURES WILL BE VERY WARM AGAIN TODAY WITH UPPER 80S IN MOST VALLEY LOCATIONS EXCEPT LOWER 90S IN THE MID HUDSON VALLEY AND LITCHFIELD CT. IT WILL BE SLIGHTLY COOLER TO THE NORTH AND WEST...WITH LOWER TO MID 80S FOR THE ADIRONDACKS AND MOHAWK VALLEY. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... ANY ISOLATED CONVECTION ACROSS SOUTHERN AREAS WILL QUICKLY DIMINISH AFTER DARK WITH LOSS OF DAYTIME HEATING. TONIGHT WILL BE COOLER THAN RECENT NIGHTS WITH THE LOWER HUMIDITY...WITH VALLEY LOCATIONS DROPPING INTO THE LOWER 60S WITH MID TO UPPER 50S IN THE HIGHER TERRAIN. A COLD FRONT WILL BE MOVING EASTWARD THROUGH THE CENTRAL AND EASTERN GREAT LAKES...AND WILL LIKELY BE JUST TO THE WEST OF OUR REGION TUESDAY MORNING. THE COLD FRONT AND ASSOCIATED UPPER LEVEL TROUGH WILL BE CROSSING THE REGION FROM WEST TO EAST DURING THE DAY TUESDAY. THERE SHOULD BE ENOUGH SURFACE HEATING AND LOW LEVEL MOISTURE INCREASING TO DEVELOP AROUND 700-1500 J/KG OF SBCAPE AHEAD OF THE COLD FRONT. 0-6 KM SHEAR IS FORECAST TO INCREASE TO BETWEEN 40-50 KTS DURING THE AFTERNOON HOURS. SHOULD THE HIGHER RANGE OF INSTABILITY BE REALIZED...THERE COULD BE A CONDITIONAL THREAT FOR SOME STRONGER ORGANIZED STORMS PRODUCING GUSTY WINDS. MID LEVEL LAPSE RATES ARE FORECAST TO BE SOMEWHAT MARGINAL...SO WE ARE NOT CONFIDENT IN MENTIONING ANY SEVERE STORMS AT THIS TIME. TRENDS WILL BE MONITORED TO SEE IF SUFFICIENT INSTABILITY CAN DEVELOP. TEMPERATURES WILL SPIKE AHEAD OF THE COLD FRONT TO BETWEEN 85 AND 90 DEGREES FROM MAINLY THE HUDSON VALLEY AND POINTS EAST. THIS WILL BE THE LAST DAY OF WELL ABOVE NORMAL TEMPERATURES FOR THE REST OF THE WEEK. BASED ON TIMING FROM MODEL GUIDANCE...CONVECTION SHOULD DIMINISH TUESDAY EVENING AS THE COLD FRONT PUSHES SOUTH AND EAST OF OUR AREA AND SUBSIDENCE TAKES OVER AS A SHORT WAVE RIDGE BUILDS IN AT THE SURFACE. A COOLER AND DRIER PATTERN LOOKS TO DEVELOP ON WEDNESDAY COURTESY OF A NORTHWEST FLOW REGIME. GENERAL TROUGHINESS ALOFT WILL RESULT IN SOME DIURNAL CLOUDINESS ESPECIALLY OVER THE HIGHER TERRAIN...WITH A FEW BRIEF SHOWERS POSSIBLE ACROSS THE ADIRONDACKS. TEMPERATURES WILL BE NOTICEABLY COOLER AND SLIGHTLY BELOW NORMAL. DEWPOINTS WILL DROP INTO THE 50S...MAKING IT FEEL QUITE COMFORTABLE FOR LATE JULY. THE COOLER AND DRIER AIR MASS WILL RESULT IN TEMPERATURES DROPPING INTO THE 50S WEDNESDAY NIGHT. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... CYCLONIC UPPER FLOW IN EASTERN NORTH AMERICA WITH MEAN UPPER TROUGHING WILL SUPPORT TEMPERATURES A LITTLE BELOW NORMAL WITH SOME INTERVALS OF CLOUDS. THE MEAN AXIS OF THE UPPER TROUGH SHOULD BE JUST EAST OF OUR REGION...SO ANY POSSIBLE SHOWERS ALONG THE SOUTHERN PERIPHERY OF THE CYCLONIC UPPER FLOW SHOULD BE ISOLATED AND MAINLY CONFINED TO NORTHERN AREAS THURSDAY AND FRIDAY. HIGHS BOTH DAYS IN THE MID TO UPPER 70S...NEAR 80 SOUTH AND AROUND 70 TO LOWER 70S NORTH. ANOTHER ORGANIZED UPPER IMPULSE APPROACHES THE REGION LATER SATURDAY WITH INCREASING WARM ADVECTION AND BOUNDARY LAYER FLOW SHIFTS TO MORE SOUTHERLY WITH SOME MOISTURE ADVECTION AS WELL. BY SATURDAY NIGHT AND SUNDAY...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER MOST OF THE REGION. WITH THE INTERVALS OF CLOUDS AND SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS...HIGHS SATURDAY AND SUNDAY IN THE UPPER 70S TO LOWER 80S...LOWER 70S NORTHERN AREAS. THERE ARE SOME DIFFERENCES IN LONG RANGE GUIDANCE IN THE SATURDAY AND SUNDAY TIME FRAME AS TO THE STRENGTH OF UPPER DYNAMICS...LOW LEVEL FORCING...MOISTURE AVAILABILITY AND TIMING OF THE SYSTEM...AND DETAILS WILL GET CLEARER AS WE GET CLOSER TO NEXT WEEKEND. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... COLD FRONT SLOW TO TRACK THROUGH THE REGION...AS NEW THUNDERSTORMS IN THE SOUTHERN ADIRONDACKS WILL GRADUALLY BUILD EAST AND SOUTH THROUGH ABOUT 09Z...POSSIBLY GETTING INTO THE VICINITY OF KGFL. PUTTING VCTS AT KGFL THROUGH 09Z...WHEN MESOSCALE MODELS SUGGEST THE THUNDERSTORMS SHOULD DISSIPATE DUE TO DECREASING INSTABILITY DURING THE EARLY MORNING HOURS. THERE ARE SOME HINTS OF LOW LEVEL MOISTURE POSSIBLY CONTRIBUTING TO SOME INTERVALS OF LOW CLOUDS AND FOG AT ALL TAF SITES THROUGH SUNRISE...BUT THICK HIGH CLOUDS AND ENOUGH OF A TEMPERATURE DEW POINT SPREAD ARE PREVENTING MUCH DEVELOPMENT OF FOG OR LOW CLOUDS. THERE ARE ALSO SOME PERSISTENT LIGHT WINDS PREVENTING MUCH OF THE FOG AND LOW CLOUDS AS WELL. ONCE CONVECTION ENDS AROUND OR AFTER 09Z...HIGH CLOUDS SHOULD THIN AND EXIT...SO SOME FOG AND LOW CLOUDINESS COULD AFFECT THE CLIMATOLOGICALLY FAVORED SITES SUCH AS KGFL AND KPSF. SO... INDICATING SOME BORDERLINE MVFR/IFR VISIBILITIES AND AT LEAST SOME SCATTERED/BROKEN CLOUDS BELOW 1000 FEET THROUGH 13Z-14Z. AFTER 13Z-14Z...ALL AREAS VFR THROUGH THE REST OF DAY AND EVENING WITH JUST SCATTERED HIGH CLOUDS AT THE MOST. SOUTH TO SOUTHWEST WINDS AT 6 KT OR LESS THROUGH SUNRISE ARE EXPECTED TO BECOME WEST TO NORTHWEST THIS MORNING AND AFTERNOON AT LESS THAN 10 KT. WINDS BECOME LIGHT AND VARIABLE AT LESS THAN 6 KT THIS EVENING. OUTLOOK... TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF TSRA. TUESDAY NIGHT TO FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA. && .FIRE WEATHER... A WEAK COLD FRONT WILL CONTINUE TO MOVE ACROSS THE REGION THIS MORNING AND SLOW ITS PROGRESS ONCE IT REACHES THE MID HUDSON VALLEY AND LITCHFIELD HILLS THIS AFTERNOON. THIS WILL RESULT IN ISOLATED THUNDERSTORMS INTO EARLY EVENING. OTHERWISE...HIGH PRESSURE WILL BUILD ACROSS THE REST OF THE REGION TODAY WITH CONTINUED VERY WARM TEMPERATURES BUT LOWER HUMIDITY LEVELS. THE HIGH WILL THEN SLIDE OFFSHORE TONIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION ON TUESDAY...BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD FROM CANADA INTO THE GREAT LAKES WEDNESDAY...USHERING IN A COOLER AND DRIER AIR MASS INTO THE REGION FOR MID WEEK TO LATE WEEK. MINIMUM RELATIVE HUMIDITY VALUES THIS AFTERNOON ARE FORECAST TO BE AROUND 35 TO 45 PERCENT...RECOVERING TO MAXIMUM VALUES OF 80 TO 100 PERCENT TONIGHT. MINIMUM RH VALUES ON TUESDAY WILL BE BETWEEN 35 AND 50 PERCENT. WINDS TODAY WILL BECOME WESTERLY AROUND 5 TO 10 MPH...SHIFTING THE NORTHWEST AROUND 5 MPH TONIGHT. WINDS ON TUESDAY WILL BECOME SOUTHWEST AND INCREASE TO AROUND 10 TO 15 MPH. && .HYDROLOGY... MAINLY DRY CONDITIONS ARE EXPECTED THROUGH TONIGHT...WITH THE EXCEPTION OF ISOLATED THUNDERSTORMS ACROSS ULSTER...DUTCHESS AND LITCHFIELD COUNTIES...WHICH MAY BRING A QUICK BURST OF HEAVY RAIN IN SOME SPOTS. THE NEXT CHANCE OF AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS ARRIVES ON TUESDAY ASSOCIATED WITH A COLD FRONT. SOME LOCALLY HEAVY RAINFALL WILL BE POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF WATER IN URBAN AND POOR DRAINAGE LOCATIONS. MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY EXCEPT FOR A FEW SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS EACH DAY. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...NAS AVIATION...NAS FIRE WEATHER...JPV HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
342 PM EDT MON JUL 20 2015 ...NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED EACH DAY THIS WEEK WITH LOCALLY HEAVY RAINFALL AND FREQUENT LIGHTNING POSSIBLE... .NEAR TERM /TONIGHT THROUGH TUESDAY/...THE SHORT RANGE PATTERN REMAINS STATIC WITH A MEAN UPPER LEVEL TROUGH ALONG THE EAST COAST...STRONG UPPER LEVEL HIGH PRESSURE OVER THE THE LOWER MISSISSIPPI RIVER VALLEY AND TEXAS...A SURFACE RIDGE ALONG THE FLORIDA EAST COAST AND TROUGHING OVER THE CONTINENTAL SOUTHEAST STATES. WITH THE MEAN FLOW OUT OF THE WEST- SOUTHWEST THE EARLY ACTIVITY ON TUESDAY SHOULD BE FROM THE GULF...THEN MOVING ACROSS THE NATURE COAST AND THEN TOWARD SAINT AUGUSTINE AND THE FLORIDA EAST COAST. LATER IN THE DAY OUR BARRAGE OF OUTFLOW BOUNDARIES AND CONVECTION SHOULD CONTINUE TO DROP OUT OF CENTRAL GEORGIA AND TOWARD SOUTHEAST GEORGIA/INTERSTATE-10. TEMPERATURES ACROSS INTERIOR SOUTHEAST GEORGIA AND THE SUWANNEE VALLEY SHOULD CONTINUE IN THE MID TO UPPER 90S AND EVEN FLIRTING WITH THE CENTURY MARK IN A FEW PLACES. WITH EARLIER CONVECTION AND HIGHER HUMIDITY SOUTH OF INTERSTATE 10 TEMPS WILL BE IN THE LOWER TO MID 90S WITH SCATTERED TO NUMEROUS THUNDERSTORMS. .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...SFC TROUGH CONTINUES TO MOVE SOUTHWARD DOWN THE ATLANTIC COAST THROUGH WEDNESDAY NIGHT WHEN IT CLOSES OFF OVER SC AND ASSOCIATED FRONTAL BOUNDARY BECOMES STATIONARY ACROSS NORTHERN GA/AL. UNSTABLE SOUTHWESTERLY FLOW WILL INTERACT WITH SFC TROUGH BOTH DAYS ALLOWING AN EARLY START TO SHOWERS AND TSTORMS EACH MORNING NEAR THE GOMEX THEN SPREADING AREA WIDE...PEAKING IN COVERAGE DURING THE MID AFTERNOON HOURS. AS THE INTENSITY OF STORMS INCREASES EACH DAY AND FORECAST SOUNDINGS CONTINUE TO SHOW PWATS OF AROUND 2.00 TO 2.25 INCHES HEAVY RAINFALL COULD BE A POTENTIAL CONCERN FOR WEDS AND THURS AFTERNOONS. ACTIVITY WILL WEAKEN AFTER SUNSET EACH DAY AND REMAIN ISOLATED DURING THE OVERNIGHT HOURS. HEAT INDICES STILL A CONCERN WEDS AND THURS AFTERNOONS REACHING 102-107 DEGREES AS DEWPOINTS DO NOT WAVER FROM THE MID 70S. .LONG TERM /FRIDAY THROUGH SUNDAY NIGHT/...WET PATTERN PERSISTS INTO THE FIRST PART OF THE WEEKEND AS SFC TROUGH AND ASSOCIATED FRONTAL BOUNDARY CONTINUE TO MOVE TOWARDS THE LOCAL AREA AND MID LEVEL RIDGE STRENGTHENS OVER THE CENTRAL US. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED AREA WIDE ON FRIDAY AFTERNOON AHEAD OF THE FRONTAL BOUNDARY...BEGINNING EARLY IN THE DAY NEAR THE GOMEX AND SUWANNEE VALLEY THEN INCREASING IN COVERAGE THROUGHOUT THE AFTERNOON. LOW WILL CENTER OVER THE AREA ON SATURDAY CONTINUING ITS SOUTHWARD PROGRESSION AS HIGH PRESSURE BRIEFLY BUILDS IN OVER SOUTHEAST GA ON SATURDAY NIGHT AND SUNDAY. SATURDAY WILL SEE HIGHEST CHANCES FOR CONVECTION FOCUSED ACROSS NE FL AS BOUNDARY WILL BE PRESENT NEAR THE FL/GA BORDER AND HIGHEST LEVELS OF MOISTURE REMAIN LOCATED TO ITS SOUTH. BY SUNDAY PATTERN BEGINS TO CHANGE AS BOUNDARY PUSHES SOUTHWARD AND DRIER AIR MASS MOVES OVER SE GA. PRECIP CHANCES WILL BE HIGHEST IN OUR SOUTHERN ZONES IN NORTH CENTRAL FL WITH ONLY WIDELY SCATTERED ACTIVITY EXPECTED OVER SE GA. TEMPS WILL REMAIN NEAR NORMAL WITH MAXS IN THE UPPER 80S/LOW 90S AND LOWS IN THE LOW/MID 70S THROUGHOUT THE LONG TERM. && .AVIATION... WILL CONTINUE TO KEEP TEMPOS IN FOR ALL OF THE FLORIDA FIELDS WITH CEILINGS ABOUT 3 KFT IN THUNDERSTORMS THROUGH THIS EVENING. WITH WITH MORE SUBSIDENCE IN EVIDENCE OVER GEORGIA WILL KEEP CONVECTION AS VICINITY FOR SAINT SIMONS ISLAND BUT THAT MAY NEED TO BE AMENDED IF CONVECTION POPS AS THE HRRR MODEL IS ADVERTISING. TUESDAY...LOOK FOR A PATTERN VERY SIMILAR TO TODAY WITH EARLY STORMS OVER THE FIELDS SOUTH OF INTERSTATE 10 AND LATER ACTIVITY NORTH OF THERE. && .MARINE... WINDS WITH TONIGHTS NOCTURNAL SOUTHWESTERLY SURGE LOOK LIKE THEY WILL REACH SCEC CRITERIA OVER THE OFFSHORE WATERS WHICH SHOULD CONTINUE INTO TUESDAY. OTHERWISE...LOOK FOR CONVECTION TO DROP OFF DURING THE EARLY EVENING HOURS TONIGHT AND THEN A REPEAT OF EARLY CONVECTION MOVING OFF THE ATLANTIC COAST TOMORROW AFTERNOON IS EXPECTED. RIP CURRENTS: LOW RISK. && .PRELIMINARY POINT TEMPS/POPS... AMG 76 94 76 95 / 40 50 30 50 SSI 79 90 79 91 / 40 40 20 40 JAX 76 93 78 94 / 50 50 20 50 SGJ 77 90 77 91 / 50 50 20 40 GNV 74 91 76 91 / 60 60 20 60 OCF 74 90 75 90 / 60 60 20 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ GUILLET/SANDRIK/SHASHY
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
909 AM EDT MON JUL 20 2015 .UPDATE... SO FAR EVERYTHING LOOKING TO BE ON TRACK THIS MORNING WITH ISOLATED CONVECTION OVER APALACHE BAY AND THE NATURE COAST. LARGE AREA OF LOW TO MID LEVEL CLOUDINESS OVER THE SOUTHEASTERN AREA OF RESPONSIBILITY MAY INHIBIT CONVECTION THIS MORNING AND THINK THE HRRR MODEL MAY BE OVER DOING THINGS JUST A BIT OVER THE SOUTH. EXPECT IT WILL POP THIS AFTERNOON BUT MAYBE A BIT AFTER THE EARLIER RUNS OF THE MODEL INDICATED. LATEST HRRR RUN NOW SEEMS TO HAVE PICKED UP ON THAT TREND AND IS A BIT LATER IN DEVELOPMENT SOUTH OF FLORIDA STATE ROAD 16. && .AVIATION... OVERALL WILL KEEP THE MENTION OT THUNDERSTORMS IN THE VICINITY FOR RIGHT NOW BUT MAY HAVE TO AMEND LATER. THAT WILL BE ESPECIALLY TRUE FOR SGJ AND GNV. && .MARINE... NO CHANGE TO CURRENT FORECAST OR THINKING. WILL HAVE TO WATCH FOR A NOCTURNAL SURGE OVER THE OFFSHORE WATERS FOR TONIGHT. WITH A SYNOPTIC SOUTHWEST FLOW LATE AFTERNOON AND EVENING STORMS WILL BE A CONCERN FOR OFFSHORE BOATERS. RIP CURRENTS: LOW RISK. && .PRELIMINARY POINT TEMPS/POPS... AMG 95 75 94 75 / 50 30 50 20 SSI 93 78 92 79 / 60 30 40 10 JAX 93 75 93 77 / 60 40 50 10 SGJ 92 76 92 76 / 60 40 50 10 GNV 92 74 92 76 / 70 30 60 10 OCF 90 74 90 74 / 40 30 60 20 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. AM...NONE. && $$ SANDRIK/SHASHY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
344 AM EDT MON JUL 20 2015 .DISCUSSION... TODAY AND TONIGHT...PRESENCE OF A FRONTAL TROUGH FROM THE MID ATLC SEABOARD TO THE FL PANHANDLE WL KEEP THE SUBTROPICAL RIDGE SITUATED SOUTH OF THE REGION. A PERSISTENT WEATHER FORECAST WITH SCATTERED AFTERNOON STORMS IS EXPECTED WITH PRECIPITABLE WATER SUITABLE NEAR 2.0 INCHES. SWLY WINDS FROM THE SFC THROUGH THE STEERING LEVEL FAVOR THE EAST PENINSULA FOR OPTIMAL CONV DEVELOPMENT FROM MID AFTERNOON ONWARD. DEVELOPMENT OF A SLOW MOVING EAST COAST BREEZE BOUNDARY WL LEAD TO HIGHEST RAIN AMOUNTS ALONG THE I-95 CORRIDOR SPACE COAST NWD. LTST HRRR GUID SHOWS THIS SCENARIO SIMILAR TO WHAT OCCURRED ON SUNDAY FROM AROUND 19Z THROUGH LATE AFTERNOON. THE ONLY INHIBITING FACTOR REMAINS MID LEVEL TEMPS AROUND -6C (WHICH IS ABOUT 1-2C WARMER THAN NORMAL). STORMS WL LARGELY COME TO AN END FROM 9-10 PM WHILE SHIFTING OVER THE ATLC WATERS AND DISSIPATING. TUESDAY...PERSISTENT MID LEVEL TROUGHING OVER THE EASTERN U.S. WL CONTINUE TO KEEP THE DLM RIDGE SUPPRESSED TO THE SOUTH OVER THE FLORIDA STRAITS. GIVEN THE NARROW MOISTURE RIBBON AND LITTLE MID AND UPPER LEVEL SUPPORT TRIMMED POP BACK TO 50 NORTH AND DECREASING TO 30 SOUTH TUESDAY AFTERNOON. SHOULD START TO SEE LATE MORNING SHOWERS COMING IN FROM THE WEST/GULF SIDE OF CENTRAL FLORIDA. SHOWERS BECOME STORMS MID TO LATE AFTERNOON WITH MAX HEATING AND AS THEY NEAR THE EAST/ATLANTIC SIDE OF CENTRAL FLORIDA AS THEY HAVE BEEN DOING THE PAST DAYS. TUESDAY NIGHT POPS LOOKED WAY TOO HIGH BASED ON WHAT HAS BEEN ACTUALLY HAPPENING THE PAST FEW DAYS THUS LOWERED THE NIGHT POP TO 20 PERCENT. STORMS AND/OR SHOWER SHOULD BE ALL OVER WITHIN AN HOUR OR TWO OF SUNSET. HIGHS TUESDAY LOW 90S AND LOWS WEDNESDAY MORNING MID 70S EXCEPT LOW/MID 70S AT THE COAST MELBOURNE SOUTH WHERE SLIGHTLY COOLER AIR FROM THE INTERIOR IS PUSHED EAST BY LAND BREEZES. WED-SUN...MODELS HAVE BEEN CONSISTENT IN SLOWLY PUSHING A FRONT SOUTHWARD ACROSS THE SOUTHEAST STATES AND DOWN THE FLORIDA PENINSULA PAST FEW RUNS. CONTINUED SOUTHWEST TO WEST WINDS AND LOW/MID 90S EACH AFTERNOON. SCATTERED/CHANCE AFTERNOON POPS WED-THU. AS THE FRONT NEARS LIKELY POP VOLUSIA/NORTH LAKE FRI THEN NORTH HALF SAT SHIFTING TO THE SOUTH HALF SUN AS THE FRONT CONTINUES IT SLOW PUSH DOWN THE STATE. HIGHS STILL IN THE LOW 90S. MORNING LOWS IN THE LOW AND MID 70S. && .AVIATION...THRU 21/12Z WINDS: THRU 20/14Z...S/SW 3-6KTS. BTWN 20/14Z-20/17Z...S/SW 6-9KTS. BTWN 20/17Z-20/23Z...COASTAL SITES S/SE 8-12KTS...INTERIOR SITES SW 7-10KTS. BTWN 20/23Z-21/03Z...S/SW 5-8KTS. AFT 21/03Z S/SW AOB 4KTS. VSBYS/WX/CIGS: BTWN 20/14Z-20/17Z...SLGT CHC MVFR SHRAS ALL SITES. BTWN 20/17Z-20/24Z...SCT MVFR SHRAS/IFR TSRAS ALL SITES...ISOLD LIFR +TSRAS WITH SFC G NR 35KTS. && .MARINE... TODAY AND TONIGHT...ATLC RIDGE AXIS OVER S FL WILL COMBINE WITH A WEAK FRONTAL TROF OVER N FL TO MAINTAIN A PERSISTENT LIGHT TO GENTLE S/SWRLY BREEZE OVER THE LCL ATLC...BCMG S/SE NEAR THE COAST IN THE EARLY AFTN WITH THE FORMATION OF THE EAST COAST SEA BREEZE. SEAS AOB 2FT NEARSHORE AND 2-3FT OFFSHORE. SCT SHRAS/TSRAS MVG OFFSHORE BTWN 2 PM AND SUNSET. TUE-FRI...WEST TO SOUTHWEST WINDS THROUGH THE PERIOD. WINDS SHOULD BE STRONG FRI AS THE GRADIENT AHEAD OF THE ADVANCING FRONT STRENGTHENS. && .PRELIMINARY POINT TEMPS/POPS... DAB 92 75 92 76 / 50 20 50 20 MCO 93 74 92 76 / 40 20 50 20 MLB 92 74 91 76 / 40 20 40 20 VRB 92 73 92 74 / 40 30 30 20 LEE 91 77 91 78 / 50 20 50 20 SFB 93 77 92 77 / 50 20 50 20 ORL 92 76 92 77 / 40 20 50 20 FPR 93 72 91 74 / 40 30 30 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...PENDERGRAST LONG TERM....WIMMER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
155 PM EDT MON JUL 20 2015 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL DOMINATE THROUGH MID WEEK WITH AN UPPER LEVEL DISTURBANCE APPROACHING THE SOUTHEAST US WEDNESDAY. ABOVE NORMAL TEMPERATURES EARLY IN THE PERIOD WITH A SLIGHT COOLING TREND BY THE END OF THE WEEK. SCATTERED DIURNAL THUNDERSTORMS EACH DAY. && .NEAR TERM /THROUGH TONIGHT/... THE SURFACE PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA THROUGH TONIGHT. ALOFT...THE AREA WILL BE ON THE EASTERN PERIPHERY OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY RIDGE. THE MODELS AND WATER VAPOR IMAGERY TRENDS INDICATE ANOTHER IN A SERIES OF MID-LEVEL SHORTWAVE TROUGHS WILL AFFECT THE AREA. THUNDERSTORM COVERAGE MAY BE LIMITED BY THE UPPER RIDGING AND SLOW STORM MOVEMENT AS INDICATED BY DIFLUENT HEIGHTS. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE TODAY. THE SPC WRF INDICATED CONSIDERABLE COVERAGE THIS EVENING. WE LEANED TOWARD THE HIGHER GUIDANCE POPS BASED ON THE PATTERN WITH THE GREATEST CHANCE LATE THIS AFTERNOON INTO THE EVENING. THE NAM HAS SURFACE-BASED LI/S -6 TO -8 TODAY. MODERATE INSTABILITY WITH AN INVERTED-V SOUNDING INDICATES DAMAGING WIND MAY OCCUR WITH A FEW OF THE THUNDERSTORMS. A SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2 INCHES ALSO INDICATES A POSSIBILITY OF LOCALIZED FLOODING. THE RECENT BIAS SUPPORTS THE HIGHER TEMPERATURE GUIDANCE. IT WILL BE ANOTHER HOT DAY WITH HIGHS AROUND 100. THUNDERSTORM COVERAGE SHOULD DIMINISH OVERNIGHT WITH THE LOSS OF HEATING AND PREVIOUS CONVECTION ALTHOUGH ANOTHER IN A SERIES OF MID-LEVEL SHORTWAVE TROUGHS SUPPORTS A CONTINUED CHANCE LATE. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... SURFACE TROUGH HANGS IN OVER THE FORECAST AREA AHEAD OF AN APPROACHING COLD FRONT THOUGH WEDNESDAY. FAIRLY ACTIVE PATTERN WITH SERIES OF MOSTLY WEAK SHORTWAVES MOVING NEAR THE AREA IN A WESTERLY FLOW ALOFT...A MORE PRONOUNCED SHORTWAVE WILL PUSH ACROSS THE REGION LATE WEDNESDAY. SPC CURRENTLY HAS US IN GENERAL THUNDER BUT COULD HAVE A FEW STRONGER STROMS ALONG COLD FRONT. MAY NEED A HEAT ADVISORY FOR SOUTHERN HALF OF CWA TUESDAY AFTERNOON 18-22Z OR SO...ENDED UP HAVING TO ISSUE ONE THIS AFTERNOON FOR AREAS SOUTH. DEWPOINTS IN LOWER 70S AND TEMPS AROUND 100 WILL BRING APPARENT TEMPS UP TO NEAR ADVISORY CRITERIA. GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST SEEMS REASONABLE. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... EXTENDED GUIDANCE KEEPS UPPER RIDGE OVER CENTRAL US WITH TROUGH OVER THE NE US. WEAK SHORTWAVES IN THE WEST TO NORTHWEST FLOW ALOFT WILL PROVIDE A TRIGGER FOR MAINLY SCATTERED CONVECTION. BEST CHANCE WHEN TRIGGER COINCIDES WITH BEST DIURNAL HEATING. TEMPERATURES LOWERING TO NEAR CLIMATOLOGY...LOWER TO MID 90S...BY THE WEEKEND. 20 TO 40 PERCENT POPS THROUGH THE PERIOD. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR CONDITIONS EXPECTED OUTSIDE OF AFTERNOON/EVENING THUNDERSTORMS. A SURFACE TROUGH OVER THE REGION AND APPROACHING SHORTWAVE ENERGY WILL PROMOTE SCATTERED DIURNAL CONVECTION MAINLY DURING THE LATE AFTERNOON AND EVENING HOURS. DAMAGING WINDS ARE THE MAIN THREAT WITH THESE STORMS. MODELS INDICATE POTENTIAL FOR BRIEF MVFR FOG EARLY TUESDAY MORNING...ALTHOUGH A 25 TO 30 KNOT LOW LEVEL JET SHOULD LIMIT DEVELOPMENT. FOG POTENTIAL AT THE TAF SITES MAY ALSO DEPEND ON WHICH SITES RECEIVE RAIN TODAY. WINDS WILL BE OUT OF THE SOUTHWEST AT AROUND 8 KNOTS THIS AFTERNOON BECOMING LIGHT AND VARIABLE AFTER SUNSET. EXTENDED AVIATION OUTLOOK...RESTRICTIONS EXPECTED IN DIURNAL CONVECTION TUESDAY THROUGH FRIDAY. AREAS OF MVFR VSBYS POSSIBLE DURING THE EARLY MORNING EACH DAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR SCZ018-025-030- 035>038-041. GA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR GAZ040-063>065- 077. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
140 PM EDT MON JUL 20 2015 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL DOMINATE THROUGH MID WEEK WITH AN UPPER LEVEL DISTURBANCE APPROACHING THE SOUTHEAST US WEDNESDAY. ABOVE NORMAL TEMPERATURES EARLY IN THE PERIOD WITH A SLIGHT COOLING TREND BY THE END OF THE WEEK. SCATTERED DIURNAL THUNDERSTORMS EACH DAY. && .NEAR TERM /THROUGH TONIGHT/... THE SURFACE PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA THROUGH TONIGHT. ALOFT...THE AREA WILL BE ON THE EASTERN PERIPHERY OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY RIDGE. THE MODELS AND WATER VAPOR IMAGERY TRENDS INDICATE ANOTHER IN A SERIES OF MID-LEVEL SHORTWAVE TROUGHS WILL AFFECT THE AREA. THUNDERSTORM COVERAGE MAY BE LIMITED BY THE UPPER RIDGING AND SLOW STORM MOVEMENT AS INDICATED BY DIFLUENT HEIGHTS. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE TODAY. THE SPC WRF INDICATED CONSIDERABLE COVERAGE THIS EVENING. WE LEANED TOWARD THE HIGHER GUIDANCE POPS BASED ON THE PATTERN WITH THE GREATEST CHANCE LATE THIS AFTERNOON INTO THE EVENING. THE NAM HAS SURFACE-BASED LI/S -6 TO -8 TODAY. MODERATE INSTABILITY WITH AN INVERTED-V SOUNDING INDICATES DAMAGING WIND MAY OCCUR WITH A FEW OF THE THUNDERSTORMS. A SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2 INCHES ALSO INDICATES A POSSIBILITY OF LOCALIZED FLOODING. THE RECENT BIAS SUPPORTS THE HIGHER TEMPERATURE GUIDANCE. IT WILL BE ANOTHER HOT DAY WITH HIGHS AROUND 100. THUNDERSTORM COVERAGE SHOULD DIMINISH OVERNIGHT WITH THE LOSS OF HEATING AND PREVIOUS CONVECTION ALTHOUGH ANOTHER IN A SERIES OF MID-LEVEL SHORTWAVE TROUGHS SUPPORTS A CONTINUED CHANCE LATE. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... SURFACE TROUGH HANGS IN OVER THE FORECAST AREA AHEAD OF AN APPROACHING COLD FRONT THOUGH WEDNESDAY. FAIRLY ACTIVE PATTERN WITH SERIES OF MOSTLY WEAK SHORTWAVES MOVING NEAR THE AREA IN A WESTERLY FLOW ALOFT...A MORE PRONOUCED SHORTWAVE WILL PUSH ACROSS THE REGION LATE WEDNESDAY. SPC CURRENTLY HAS US IN GENERAL THUNDER BUT COULD HAVE A FEW STRONGER STROMS ALONG COLD FRONT. MAY NEED A HEAT ADVISORY FOR SOUTHERN HALF OF CWA TUESDAY AFTERNOON 18-22Z OR SO...ENDED UP HAVING TO ISSUE ONE THIS AFTERNOON FOR AREAS SOUTH. DEWPOINTS IN LOWER 70S AND TEMPS AROUND 100 WILL BRING APPARENT TEMPS UP TO NEAR ADVISORY CRITERIA. GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST SEEMS REASONABLE. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... EXTENDED GUIDANCE KEEPS UPPER RIDGE OVER CENTRAL US WITH TROUGH OVER THE NE US. WEAK SHORTWAVES IN THE WEST TO NORTHWEST FLOW ALOFT WILL PROVIDE A TRIGGER FOR MAINLY SCATTERED CONVECTION. BEST CHANCE WHEN TRIGGER COINCIDES WITH BEST DIURNAL HEATING. TEMPERATURES LOWERING TO NEAR CLIMATOLOGY...LOWER TO MID 90S...BY THE WEEKEND. 20 TO 40 PERCENT POPS THROUGH THE PERIOD. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR CONDITIONS EXPECTED OUTSIDE OF DIURNAL THUNDERSTORMS AND EARLY MORNING FOG. LIGHT WEST WINDS DURING THE MORNING BECOMING SOUTHWEST 8-10 KNOTS THIS AFTERNOON. SCATTERED DIURNAL CONVECTION TO DEVELOP AFTER 18Z AND CONTINUING INTO THE EARLY EVENING. MODELS INDICATE POTENTIAL FOR FOG EARLY TUESDAY MORNING...ALTHOUGH A 25 TO 30 KNOT NOCTURNAL JET SHOULD LIMIT DEVELOPMENT. FOG POTENTIAL MAY ALSO DEPEND ON WHICH SITES RECEIVE RAIN TODAY. EXTENDED AVIATION OUTLOOK...RESTRICTIONS EXPECTED IN DIURNAL CONVECTION TUESDAY THROUGH FRIDAY. AREAS OF MVFR VSBYS POSSIBLE DURING THE EARLY MORNING EACH DAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR SCZ018-025-030- 035>038-041. GA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR GAZ040-063>065- 077. && $$ 87
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
806 AM EDT MON JUL 20 2015 .SYNOPSIS... A PRESSURE RIDGE WILL EXTEND FROM THE ATLANTIC WESTWARD THROUGH THE GULF OF MEXICO THROUGH WEDNESDAY. NORTH OF THE RIDGE A PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... THE SURFACE PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA THROUGH TONIGHT. ALOFT...THE AREA WILL BE ON THE EASTERN PERIPHERY OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY RIDGE. THE MODELS AND WATER VAPOR IMAGERY TRENDS INDICATE ANOTHER IN A SERIES OF MID-LEVEL SHORTWAVE TROUGHS WILL AFFECT THE AREA. THUNDERSTORM COVERAGE MAY BE LIMITED BY THE UPPER RIDGING AND SLOW STORM MOVEMENT AS INDICATED BY DIFLUENT HEIGHTS. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE TODAY. THE SPC WRF INDICATED CONSIDERABLE COVERAGE THIS EVENING. WE LEANED TOWARD THE HIGHER GUIDANCE POPS BASED ON THE PATTERN WITH THE GREATEST CHANCE LATE THIS AFTERNOON INTO THE EVENING. THE NAM HAS SURFACE-BASED LI/S -6 TO -8 TODAY. MODERATE INSTABILITY WITH AN INVERTED-V SOUNDING INDICATES DAMAGING WIND MAY OCCUR WITH A FEW OF THE THUNDERSTORMS. A SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2 INCHES ALSO INDICATES A POSSIBILITY OF LOCALIZED FLOODING. THE RECENT BIAS SUPPORTS THE HIGHER TEMPERATURE GUIDANCE. IT WILL BE ANOTHER HOT DAY WITH HIGHS AROUND 100. THUNDERSTORM COVERAGE SHOULD DIMINISH OVERNIGHT WITH THE LOSS OF HEATING AND PREVIOUS CONVECTION ALTHOUGH ANOTHER IN A SERIES OF MID-LEVEL SHORTWAVE TROUGHS SUPPORTS A CONTINUED CHANCE LATE. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... THE SURFACE TROUGH WILL CONTINUE IN THE FORECAST AREA AHEAD OF AN APPROACHING COLD FRONT THROUGH TUESDAY NIGHT. THERE WILL ALSO BE A SERIES OF MID-LEVEL SHORTWAVE TROUGHS IN THE WESTERLY FLOW. THE PATTERN SUPPORTS A CONTINUED CHANCE OF THUNDERSTORMS. FORECASTED THE HIGHER POPS NEAR THE TIME OF MAXIMUM HEATING. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. IT WILL REMAIN HOT AHEAD OF THE FRONT TUESDAY WITH HIGHS AROUND 100. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... THE GFS AND ECMWF DISPLAY A FRONT STALLED IN THE FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE FRONT MAY BE JUST SOUTH OF THE AREA LATER IN THE PERIOD. ALOFT...THE MODELS INDICATE UPPER TROUGHING ALONG THE EAST COAST. THE PATTERN SUPPORTS CHANCE POPS WITH TEMPERATURES LOWERING TO NEAR CLIMATOLOGY. THE GFS... ECMWF...AND EKD MOS HAVE HIGHS NEAR 100 WEDNESDAY AND IN THE LOWER AND MIDDLE 90S DURING THE REST OF THE PERIOD. THE MOS HAS POPS 20 TO 40 PERCENT THROUGH THE PERIOD. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... VFR CONDITIONS EXPECTED OUTSIDE OF DIURNAL THUNDERSTORMS AND EARLY MORNING FOG. LIGHT WEST WINDS DURING THE MORNING BECOMING SOUTHWEST 8-10 KNOTS THIS AFTERNOON. SCATTERED DIURNAL CONVECTION TO DEVELOP AFTER 18Z AND CONTINUING INTO THE EARLY EVENING. MODELS INDICATE POTENTIAL FOR FOG EARLY TUESDAY MORNING...ALTHOUGH A 25 TO 30 KNOT NOCTURNAL JET SHOULD LIMIT DEVELOPMENT. FOG POTENTIAL MAY ALSO DEPEND ON WHICH SITES RECEIVE RAIN TODAY. EXTENDED AVIATION OUTLOOK...RESTRICTIONS EXPECTED IN DIURNAL CONVECTION TUESDAY THROUGH FRIDAY. AREAS OF MVFR VSBYS POSSIBLE DURING THE EARLY MORNING EACH DAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
615 AM EDT MON JUL 20 2015 .SYNOPSIS... A PRESSURE RIDGE WILL EXTEND FROM THE ATLANTIC WESTWARD THROUGH THE GULF OF MEXICO THROUGH WEDNESDAY. NORTH OF THE RIDGE A PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA. THE PATTERN WILL BRING ABOVE NORMAL TEMPERATURES WITH SCATTERED MAINLY DIURNAL THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG HAS DEVELOPED...MAINLY IN AREAS THAT RECEIVED RAIN YESTERDAY. HEATING AND MIXING WILL DISSIPATE ANY FOG EARLY THIS MORNING. THE SURFACE PRESSURE TROUGH WILL REMAIN IN THE FORECAST AREA THROUGH TONIGHT. ALOFT...THE AREA WILL BE ON THE EASTERN PERIPHERY OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY RIDGE. THE MODELS AND WATER VAPOR IMAGERY TRENDS INDICATE ANOTHER IN A SERIES OF MID-LEVEL SHORTWAVE TROUGHS WILL AFFECT THE AREA. THUNDERSTORM COVERAGE MAY BE LIMITED BY THE UPPER RIDGING AND SLOW STORM MOVEMENT AS INDICATED BY DIFLUENT HEIGHTS. THE HRRR AND ARW DISPLAY ISOLATED TO SCATTERED COVERAGE TODAY. THE SPC WRF INDICATED CONSIDERABLE COVERAGE THIS EVENING. WE LEANED TOWARD THE HIGHER GUIDANCE POPS BASED ON THE PATTERN WITH THE GREATEST CHANCE LATE THIS AFTERNOON INTO THE EVENING. THE NAM HAS SURFACE-BASED LI/S -6 TO -8 TODAY. MODERATE INSTABILITY WITH AN INVERTED-V SOUNDING INDICATES DAMAGING WIND MAY OCCUR WITH A FEW OF THE THUNDERSTORMS. A SLOW STORM MOVEMENT AND PRECIPITABLE WATER NEAR 2 INCHES ALSO INDICATES A POSSIBILITY OF LOCALIZED FLOODING. THE RECENT BIAS SUPPORTS THE HIGHER TEMPERATURE GUIDANCE. IT WILL BE ANOTHER HOT DAY WITH HIGHS AROUND 100. THUNDERSTORM COVERAGE SHOULD DIMINISH OVERNIGHT WITH THE LOSS OF HEATING AND PREVIOUS CONVECTION ALTHOUGH ANOTHER IN A SERIES OF MID-LEVEL SHORTWAVE TROUGHS SUPPORTS A CONTINUED CHANCE LATE. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... THE SURFACE TROUGH WILL CONTINUE IN THE FORECAST AREA AHEAD OF AN APPROACHING COLD FRONT THROUGH TUESDAY NIGHT. THERE WILL ALSO BE A SERIES OF MID-LEVEL SHORTWAVE TROUGHS IN THE WESTERLY FLOW. THE PATTERN SUPPORTS A CONTINUED CHANCE OF THUNDERSTORMS. FORECASTED THE HIGHER POPS NEAR THE TIME OF MAXIMUM HEATING. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. IT WILL REMAIN HOT AHEAD OF THE FRONT TUESDAY WITH HIGHS AROUND 100. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... THE GFS AND ECMWF DISPLAY A FRONT STALLED IN THE FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. THE FRONT MAY BE JUST SOUTH OF THE AREA LATER IN THE PERIOD. ALOFT...THE MODELS INDICATE UPPER TROUGHING ALONG THE EAST COAST. THE PATTERN SUPPORTS CHANCE POPS WITH TEMPERATURES LOWERING TO NEAR CLIMATOLOGY. THE GFS... ECMWF...AND EKD MOS HAVE HIGHS NEAR 100 WEDNESDAY AND IN THE LOWER AND MIDDLE 90S DURING THE REST OF THE PERIOD. THE MOS HAS POPS 20 TO 40 PERCENT THROUGH THE PERIOD. && .AVIATION /10Z MONDAY THROUGH FRIDAY/... AREAS OF MVFR VSBYS POSSIBLE 12Z-13Z. SHOULD SEE VFR CONDITIONS RETURN TO ALL TAF SITES BY 14Z AS MIXING COMMENCES. LIGHT WEST WINDS DURING THE MORNING BECOMING SOUTHWEST 8-10 KNOTS IN THE AFTERNOON. SCATTERED DIURNAL CONVECTION TO DEVELOP AFTER 18Z AND CONTINUING INTO THE EARLY EVENING. EXTENDED AVIATION OUTLOOK...RESTRICTIONS EXPECTED IN DIURNAL CONVECTION TUESDAY THROUGH FRIDAY. AREAS OF MVFR VSBYS POSSIBLE DURING THE EARLY MORNING EACH DAY. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
514 PM CDT MON JUL 20 2015 .SHORT TERM... 230 PM CDT THROUGH TONIGHT... A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL BE HARD TO COME BY. A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM. COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS. THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW TEMPERATURES BY DAYBREAK NEAR NORMAL. MTF && .LONG TERM... 328 PM CDT TUESDAY THROUGH MONDAY... NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER VORT MAX. TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE. GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS. THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM. RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 22Z... * CHANCE OF SHRA/ISOLATED TSRA...MAINLY EARLY EVENING. * NE WINDS ABOVE 10 KT LATE TONIGHT INTO EARLY TUESDAY. MDB //DISCUSSION...UPDATED 22Z... UPPER LEVEL SHORTWAVE CONTINUES TO DRIVE SHRA/TSRA SOUTH OF THE TERMINALS GENERALLY SOUTH OF A LINE FROM KC09 TO KIGQ WITH SOME SPOTTY SPRINKLES/LIGHT RAIN TO THE NORTH. NOT EXPECTING THIS AREA OF SHRA/TSRA TO EXPAND NORTHWARD MUCH OF AT ALL. SCATTERED SHRA/TSRA HAS DEVELOPED ALONG OR JUST BEHIND AN APPROACHING COOL FRONT ACROSS CENTRAL AND SOUTHWEST WISCONSIN. RADAR TRENDS SUPPORT THIS ACTIVITY MOVING ACROSS THE TERMINALS EARLY THIS EVENING BUT IT MAY HAVE A DIFFICULT TIME HOLDING TOGETHER WITH TIME AS IT WILL BE MOVING INTO AN AREA THAT HAS HAD FAIRLY EXTENSIVE CLOUD COVER MOST OF THE DAY. WILL MAINTAIN TEMPO SHRA MENTION BUT SLOW THE TIMING SLIGHTLY. COULD SEE SOME ISOLATED THUNDER BUT THE POTENTIAL IS TOO LOW TO MENTION IN THE TAF. MDB FROM 18Z... CURRENT SHOWER ACTIVITY PUSHING THROUGH SOUTHERN WISCONSIN AND CROSSING THE MISSISSIPPI RIVER INTO ILLINOIS IS TIED TO A POTENT UPPER LEVEL SHORT WAVE IN IOWA. THIS ACTIVITY IS OUT AHEAD OF A COLD FRONT SLATED TO COME THROUGH NORTHEAST ILLINOIS LATER THIS EVENING. UPSTREAM OBSERVATIONS ARE IN A SLIGHTLY MORE MOIST ENVIRONMENT AND HAVE BEEN ABLE TO SATURATE THE LOWER LEVELS TO SUPPORT SOME RAIN. DEWPOINTS OVER NORTHEAST ILLINOIS ARE LOWER THAN THESE AREAS...THEREFORE IN SPITE OF THE WAVE TRACKING RIGHT THROUGH THE AREA THIS AFTERNOON...SHOWER ACTIVITY...AND ESPECIALLY ANY LIMITED THUNDER POTENTIAL...WILL STRUGGLE INITIALLY. THERE IS SOME CUMULUS DEVELOPMENT AHEAD OF THIS WAVE AS WELL. HAVE INTRODUCED VCSH FOR THE TAFS FOR LATER THIS AFTERNOON TO ACCOUNT FOR THIS PERIOD...BUT OVERALL IMPACTS SHOULD BE MINIMAL. AFTER THE WAVE GOES PAST...IT APPEARS THE SLIGHTLY BETTER CHANCE FOR SCATTERED SHOWER/ISOLATED THUNDER DEVELOPMENT WILL BE TIED TO THE COLD FRONT...WHICH TRAILS THE UPPER LEVEL FORCING. WHILE COVERAGE IS STILL IN QUESTION...BEST TIMING OF ACTIVITY WILL BE JUST AHEAD OF THE FRONT IN THE 0-3Z TIME FRAME...WITH A SHIFT TO NW WINDS 4-6Z. CURRENT TAFS PEG THE 0-2Z TIME FRAME AT THE CHICAGO TERMINALS...COULD BE 1-3Z PER SOME CONVECTIVE ALLOWING MODELS. A FLOP OVER TO NE WINDS IS EXPECTED OVERNIGHT WITH AN INCREASE IN SPEEDS ABOVE 11 KT POSSIBLY INTO THE MORNING RUSH. WINDS BACK TO NNW LATER TUESDAY....THOUGH THEY HANG ON NE CLOSER TO THE LAKE. KMD //ORD AND MDW CONFIDENCE...UPDATED 22Z... * MEDIUM-HIGH IN TIMING OF SHRA POTENTIAL. MEDIUM-HIGH CONFIDENCE THAT TSRA POTENTIAL AT THE TERMINALS IS LOW BUT MEDIUM IN SHRA OCCURRENCE. * MEDIUM-HIGH ON WIND SPEEDS AND TRENDS. MDB //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL. SATURDAY...CHANCE TSRA THROUGH THE EVENING. OTRW...VFR. SUNDAY...VFR. WX NIL. KREIN && .MARINE... 230 PM CDT A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE LAKE FOR A QUIET MIDWEEK PERIOD. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
330 PM CDT MON JUL 20 2015 .SHORT TERM... 230 PM CDT THROUGH TONIGHT... A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL BE HARD TO COME BY. A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM. COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS. THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW TEMPERATURES BY DAYBREAK NEAR NORMAL. MTF && .LONG TERM... 328 PM CDT TUESDAY THROUGH MONDAY... NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER VORT MAX. TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE. GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS. THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM. RC && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * CHANCE OF SHRA/ISOLATED TSRA...MAINLY EARLY EVENING. * NE WINDS ABOVE 10 KT LATE TONIGHT INTO EARLY TUESDAY. KMD //DISCUSSION...UPDATED 18Z... CURRENT SHOWER ACTIVITY PUSHING THROUGH SOUTHERN WISCONSIN AND CROSSING THE MISSISSIPPI RIVER INTO ILLINOIS IS TIED TO A POTENT UPPER LEVEL SHORT WAVE IN IOWA. THIS ACTIVITY IS OUT AHEAD OF A COLD FRONT SLATED TO COME THROUGH NORTHEAST ILLINOIS LATER THIS EVENING. UPSTREAM OBSERVATIONS ARE IN A SLIGHTLY MORE MOIST ENVIRONMENT AND HAVE BEEN ABLE TO SATURATE THE LOWER LEVELS TO SUPPORT SOME RAIN. DEWPOINTS OVER NORTHEAST ILLINOIS ARE LOWER THAN THESE AREAS...THEREFORE IN SPITE OF THE WAVE TRACKING RIGHT THROUGH THE AREA THIS AFTERNOON...SHOWER ACTIVITY...AND ESPECIALLY ANY LIMITED THUNDER POTENTIAL...WILL STRUGGLE INITIALLY. THERE IS SOME CUMULUS DEVELOPMENT AHEAD OF THIS WAVE AS WELL. HAVE INTRODUCED VCSH FOR THE TAFS FOR LATER THIS AFTERNOON TO ACCOUNT FOR THIS PERIOD...BUT OVERALL IMPACTS SHOULD BE MINIMAL. AFTER THE WAVE GOES PAST...IT APPEARS THE SLIGHTLY BETTER CHANCE FOR SCATTERED SHOWER/ISOLATED THUNDER DEVELOPMENT WILL BE TIED TO THE COLD FRONT...WHICH TRAILS THE UPPER LEVEL FORCING. WHILE COVERAGE IS STILL IN QUESTION...BEST TIMING OF ACTIVITY WILL BE JUST AHEAD OF THE FRONT IN THE 0-3Z TIME FRAME...WITH A SHIFT TO NW WINDS 4-6Z. CURRENT TAFS PEG THE 0-2Z TIME FRAME AT THE CHICAGO TERMINALS...COULD BE 1-3Z PER SOME CONVECTIVE ALLOWING MODELS. A FLOP OVER TO NE WINDS IS EXPECTED OVERNIGHT WITH AN INCREASE IN SPEEDS ABOVE 11 KT POSSIBLY INTO THE MORNING RUSH. WINDS BACK TO NNW LATER TUESDAY....THOUGH THEY HANG ON NE CLOSER TO THE LAKE. KMD //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM/HIGH IN TIMING IF ANY SHOWERS ARE TO OCCUR. LOW IN TSRA DIRECTLY IMPACTING THE TERMINALS BUT MEDIUM IN SHRA. * MEDIUM/HIGH ON WIND SPEEDS AND TRENDS. KMD //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL. SATURDAY...CHANCE TSRA THROUGH THE EVENING. OTRW...VFR. SUNDAY...VFR. WX NIL. KREIN && .MARINE... 230 PM CDT A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE LAKE FOR A QUIET MIDWEEK PERIOD. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
239 PM CDT MON JUL 20 2015 .SHORT TERM... 230 PM CDT THROUGH TONIGHT... A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL BE HARD TO COME BY. A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM. COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS. THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW TEMPERATURES BY DAYBREAK NEAR NORMAL. MTF && .LONG TERM... TUESDAY THROUGH SUNDAY... TO BE ISSUED SHORTLY. && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 20Z... * CHANCE OF SHRA/ISOLATED TSRA...MAINLY EARLY EVENING. * NE WINDS ABOVE 10 KT LATE TONIGHT INTO EARLY TUESDAY. KMD //DISCUSSION...UPDATED 18Z... CURRENT SHOWER ACTIVITY PUSHING THROUGH SOUTHERN WISCONSIN AND CROSSING THE MISSISSIPPI RIVER INTO ILLINOIS IS TIED TO A POTENT UPPER LEVEL SHORT WAVE IN IOWA. THIS ACTIVITY IS OUT AHEAD OF A COLD FRONT SLATED TO COME THROUGH NORTHEAST ILLINOIS LATER THIS EVENING. UPSTREAM OBSERVATIONS ARE IN A SLIGHTLY MORE MOIST ENVIRONMENT AND HAVE BEEN ABLE TO SATURATE THE LOWER LEVELS TO SUPPORT SOME RAIN. DEWPOINTS OVER NORTHEAST ILLINOIS ARE LOWER THAN THESE AREAS...THEREFORE IN SPITE OF THE WAVE TRACKING RIGHT THROUGH THE AREA THIS AFTERNOON...SHOWER ACTIVITY...AND ESPECIALLY ANY LIMITED THUNDER POTENTIAL...WILL STRUGGLE INITIALLY. THERE IS SOME CUMULUS DEVELOPMENT AHEAD OF THIS WAVE AS WELL. HAVE INTRODUCED VCSH FOR THE TAFS FOR LATER THIS AFTERNOON TO ACCOUNT FOR THIS PERIOD...BUT OVERALL IMPACTS SHOULD BE MINIMAL. AFTER THE WAVE GOES PAST...IT APPEARS THE SLIGHTLY BETTER CHANCE FOR SCATTERED SHOWER/ISOLATED THUNDER DEVELOPMENT WILL BE TIED TO THE COLD FRONT...WHICH TRAILS THE UPPER LEVEL FORCING. WHILE COVERAGE IS STILL IN QUESTION...BEST TIMING OF ACTIVITY WILL BE JUST AHEAD OF THE FRONT IN THE 0-3Z TIME FRAME...WITH A SHIFT TO NW WINDS 4-6Z. CURRENT TAFS PEG THE 0-2Z TIME FRAME AT THE CHICAGO TERMINALS...COULD BE 1-3Z PER SOME CONVECTIVE ALLOWING MODELS. A FLOP OVER TO NE WINDS IS EXPECTED OVERNIGHT WITH AN INCREASE IN SPEEDS ABOVE 11 KT POSSIBLY INTO THE MORNING RUSH. WINDS BACK TO NNW LATER TUESDAY....THOUGH THEY HANG ON NE CLOSER TO THE LAKE. KMD //ORD AND MDW CONFIDENCE...UPDATED 20Z... * MEDIUM/HIGH IN TIMING IF ANY SHOWERS ARE TO OCCUR. LOW IN TSRA DIRECTLY IMPACTING THE TERMINALS BUT MEDIUM IN SHRA. * MEDIUM/HIGH ON WIND SPEEDS AND TRENDS. KMD //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL. SATURDAY...CHANCE TSRA THROUGH THE EVENING. OTRW...VFR. SUNDAY...VFR. WX NIL. KREIN && .MARINE... 230 PM CDT A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE LAKE FOR A QUIET MIDWEEK PERIOD. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
231 PM CDT MON JUL 20 2015 .SHORT TERM... 230 PM CDT THROUGH TONIGHT... A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL BE HARD TO COME BY. A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM. COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS. THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW TEMPERATURES BY DAYBREAK NEAR NORMAL. MTF && .LONG TERM... TUESDAY THROUGH SUNDAY... TO BE ISSUED SHORTLY. && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 18Z... * CHANCE OF SHRA/ISOLATED TSRA...MAINLY EARLY EVENING. SCHC LATE THIS AFTERNOON. * NE WINDS ABOVE 10 KT LATE TONIGHT INTO EARLY TUESDAY. KMD //DISCUSSION...UPDATED 18Z... CURRENT SHOWER ACTIVITY PUSHING THROUGH SOUTHERN WISCONSIN AND CROSSING THE MISSISSIPPI RIVER INTO ILLINOIS IS TIED TO A POTENT UPPER LEVEL SHORT WAVE IN IOWA. THIS ACTIVITY IS OUT AHEAD OF A COLD FRONT SLATED TO COME THROUGH NORTHEAST ILLINOIS LATER THIS EVENING. UPSTREAM OBSERVATIONS ARE IN A SLIGHTLY MORE MOIST ENVIRONMENT AND HAVE BEEN ABLE TO SATURATE THE LOWER LEVELS TO SUPPORT SOME RAIN. DEWPOINTS OVER NORTHEAST ILLINOIS ARE LOWER THAN THESE AREAS...THEREFORE IN SPITE OF THE WAVE TRACKING RIGHT THROUGH THE AREA THIS AFTERNOON...SHOWER ACTIVITY...AND ESPECIALLY ANY LIMITED THUNDER POTENTIAL...WILL STRUGGLE INITIALLY. THERE IS SOME CUMULUS DEVELOPMENT AHEAD OF THIS WAVE AS WELL. HAVE INTRODUCED VCSH FOR THE TAFS FOR LATER THIS AFTERNOON TO ACCOUNT FOR THIS PERIOD...BUT OVERALL IMPACTS SHOULD BE MINIMAL. AFTER THE WAVE GOES PAST...IT APPEARS THE SLIGHTLY BETTER CHANCE FOR SCATTERED SHOWER/ISOLATED THUNDER DEVELOPMENT WILL BE TIED TO THE COLD FRONT...WHICH TRAILS THE UPPER LEVEL FORCING. WHILE COVERAGE IS STILL IN QUESTION...BEST TIMING OF ACTIVITY WILL BE JUST AHEAD OF THE FRONT IN THE 0-3Z TIME FRAME...WITH A SHIFT TO NW WINDS 4-6Z. CURRENT TAFS PEG THE 0-2Z TIME FRAME AT THE CHICAGO TERMINALS...COULD BE 1-3Z PER SOME CONVECTIVE ALLOWING MODELS. A FLOP OVER TO NE WINDS IS EXPECTED OVERNIGHT WITH AN INCREASE IN SPEEDS ABOVE 11 KT POSSIBLY INTO THE MORNING RUSH. WINDS BACK TO NNW LATER TUESDAY....THOUGH THEY HANG ON NE CLOSER TO THE LAKE. KMD //ORD AND MDW CONFIDENCE...UPDATED 18Z... * MEDIUM/HIGH IN TIMING IF ANY SHOWERS ARE TO OCCUR. LOW IN TSRA DIRECTLY IMPACTING THE TERMINALS BUT MEDIUM IN SHRA. * MEDIUM/HIGH ON WIND SPEEDS AND TRENDS. KMD //OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z... TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL. SATURDAY...CHANCE TSRA THROUGH THE EVENING. OTRW...VFR. SUNDAY...VFR. WX NIL. KREIN && .MARINE... 230 PM CDT A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE LAKE FOR A QUIET MIDWEEK PERIOD. MTF && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1248 PM CDT MON JUL 20 2015 .UPDATE... ISSUED AT 1040 AM CDT MON JUL 20 2015 UPDATED THE FORECAST TO REMOVE PATCHY FOG THIS MORNING AND ALSO LOWERED CHANCES OF SHOWERS AND THUNDERSTORMS THIS MORNING. ANOTHER VERY WARM AND HUMID DAY EXPECTED WITH HIGHS IN THE MID TO UPPER 80S AND DEWPOINTS IN THE LOW TO MID 70S. HEAT INDICES THIS AFTERNOON TO PEAK IN THE UPPER 80S/LOWER 90S OVER CENTRAL IL AND MID TO UPPER 90S IN SOUTHEAST IL. MCS/MCV MOVING EAST OUT OF MO INTO SW AND WEST CENTRAL IL WITH LEADING EDGE OF SHOWERS AND THUNDERSTORMS AS FAR EAST AS A BEARDSTOWN TO JACKSONVILLE TO EAST OF ST LOUIS LINE AND TRACKING EAST AT 35 MPH. RAP MODEL APPEARED TO HAVE BEST HANDLE ON THIS MCS AND IT SPREADS QPF EAST ACROSS AREAS FROM RUSHVILLE TO RANTOUL SOUTH DURING THE AFTERNOON. A COLD FRONT OVER CENTRAL PARTS OF WI/IA AND SHORT WAVE OVER IA TO TRACK SE INTO NW IL LATER THIS AFTERNOON AND TO HAVE SHOWERS AND THUNDERSTORMS ALONG THIS BOUNDARY AS WELL MOVING INTO IL RIVER VALLEY LATE TODAY. SO WILL CONTINUE CHANCES OF SHOWERS AND THUNDESTORMS ACROSS CENTRAL/SE IL THIS AFTERNOON WITH HIGHEST CHANCES OF RAIN FROM I-72 SOUTH. SPC HAS SHIFTED SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON/EVENING SOUTH OF CLAY...RICHLAND AND LAWERENCE COUNTIES. BUT MARGINAL RISK OF SEVERE STORMS COVERS CENTRAL IL CWA WITH 5-15% RISK OF HAIL AND DAMAGING WIND GUSTS. MODEST MUCAPES ARE 1500-2500 J/KG SW CWA THIS AFTERNOON WHILE MODEST BULK SHEAR IS 25-35 KTS. LOCALLY HEAVY RAINS AND FREQUENT LIGHTNING ALSO POSSIBLE WITH STRONGER STORMS FROM MID AFTERNOON INTO EARLY EVENING UNTIL SUNSET. && .SHORT TERM...(TODAY) ISSUED AT 318 AM CDT MON JUL 20 2015 CONVECTION THAT DEVELOPED NEAR ST.LOUIS LAST EVENING HAS SHIFTED SOUTHEAST INTO EXTREME SOUTHERN ILLINOIS EARLY THIS MORNING. THE STORMS ARC BACK TO THE NORTHWEST INTO PARTS OF WESTERN MO INTO NORTHEAST KS ALONG A FRONTAL BOUNDARY WHICH LOOKS TO BE THE MAIN FOCUS FOR ADDITIONAL DEVELOPMENT LATER TODAY. QUESTION BECOMES WHAT AFFECT FURTHER NORTH INTO OUR AREA IT MAY HAVE ON COVERAGE OF SHOWERS AND STORMS THIS AFTERNOON AND THIS EVENING AS ANOTHER COOL FRONT TRACKS ACROSS THE AREA FROM THE NORTHWEST LATE TODAY. USING THE TIMING AND COVERAGE OFF THE RAP MODEL WOULD SUGGEST A SLOWER ONSET OF PRECIP THAN EARLIER EXPECTED WITH THE BULK OF THE ACTIVITY TIED TO THE SURFACE BOUNDARY STRETCHING ACROSS MISSOURI THRU FAR SOUTHERN ILLINOIS...WITH A SECONDARY BAND OF SHOWERS AND STORMS SHOWING UP ALONG THE WEAK COOL FRONT WHICH IS FORECAST TO BE JUST TO OUR NORTHWEST LATE THIS AFTERNOON. THE HIGHER POPS WILL BE FOR MAINLY THIS AFTERNOON WITH ONLY LOW CHANCE POPS FOR PRECIP THIS MORNING ACROSS OUR WEST. MIXED LAYER CAPES OFF THE NAM MODEL FOR THIS AFTERNOON ARE EXPECTED TO RANGE FROM 1500-2000 J/KG WITH 0-6KM SHEAR VALUES OF 30 KTS. 700-500 MB LAPSE RATES NOT LOOKING THAT IMPRESSIVE THOUGH...BUT STILL CAN`T RULE OUT A STRONG TO LOCALLY SEVERE STORM THAT MAY BE CAPABLE OF PRODUCING GUSTY WINDS ALONG WITH HEAVY RAINFALL DURING THE MID TO LATE AFTERNOON HOURS. SPC HAS SHIFTED THE SLIGHT RISK FURTHER SOUTH AND WEST...CLOSER TO THE AFOREMENTIONED BOUNDARY OVER MISSOURI. WITH THE MAIN CONVECTIVE FRONT EXPECTED TO REMAIN TO OUR SOUTH...IT APPEARS THAT IS WHERE THE MORE CONCENTRATED AREA OF HEAVY RAINFALL WILL OCCUR...AS A RESULT...WILL NOT BE INCLUDING ANY FLASH FLOOD WATCH AT THIS TIME FOR OUR FAR WESTERN COUNTIES WHICH RECEIVED HEAVY RAINFALL LAST NIGHT. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 318 AM CDT MON JUL 20 2015 SEVERAL WEAK BOUNDARIES IN THE REGION AND WILL CONTINUE TO PROVIDE FOCUS FOR AN IMPULSE BRINGING PRECIP TODAY AND INTO TONIGHT. HOWEVER, MODELS ARE SHIFTING SOUTH SOMEWHAT AND FOR THE MOST PART, PUSH A COLD FRONT THROUGH THE STATE CONSIDERABLY FASTER TONIGHT. GFS AND ECMWF ARE LARGELY DRY AFTER 06Z, WITH THE NAM STILL STRUGGLING. HAVE PUSHED THE GRIDS CLOSER TO THAT SOLUTION, BUT THE SLOWING NATURE OF THE BOUNDARY TOWARDS TOMORROW MORNING...HAVE KEPT THE SLIGHTS ALONG AND SOUTH OF I-70, ALTHOUGH THOSE SMALL POPS MAY ALSO GET PULLED WITH SUBSEQUENT FORECASTS IF THE TRENDS CONTINUE. ELUSIVE DRY TREND IS BACK IN THE FORECAST FROM TOMORROW AFTERNOON THROUGH WED EVENING, AND MUCH OF THURSDAY. THURSDAY A WAVE DIVES INTO THE REGION AND ALTHOUGH MUCH OF THE PRECIP LOOKS TO PASS TO THE SW, SOME SMALL POPS ARE WORKING THEIR WAY INTO THE SUPERBLEND ALONG AND SW OF A LINE FROM HAVANA TO LAWRENCEVILLE. CONCERNED WITH THE LOOK OF THE MODELS IN THAT TIME FRAME ARE NOT PROPERLY REPRESENTED IN THE SUPERBLEND JUST YET. GFS IS MORE AGGRESSIVE WITH THE QPF ON THURSDAY NIGHT OVER IL...AND ECMWF PASSES THE WAVE ALOFT IN THE SAME TIME FRAME WITH LITTLE TO SHOW AT THE SFC. EXPECT SOME CHANGES IN THIS PORTION OF THE FORECAST. WARMING TREND CONTINUES THROUGH THE END OF THE WEEK, WITH THE HIGHEST TEMPS IN THE FORECAST NEXT WEEKEND AGAIN. WITH THE WARM TEMPS, A RIDGE BUILDS IN THE DESERT SW AND SOUTHERN PLAINS. ILLINOIS HAS VERY LITTLE IN THE WAY OF STEERING FLOW AND MODELS ARE A BIT MORE SCATTERED WITH WEAK WAVES...WITH THE GFS AND ECMWF DIVERGING AT THE WEEKEND DEALING WITH A TROF PASSING ACROSS THE NRN TIER OF THE CONUS. FOR NOW, SLIGHT/CHANCE POPS THROUGH THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1245 PM CDT MON JUL 20 2015 MCV SOUTH OF VANDALIA WILL TRACK EAST ACROSS SE CWA THIS AFTERNOON WHERE BEST CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE SOUTH OF I-72. MEANWHILE A COLD FRONT OVER CENTRAL PARTS OF WI/IA WILL MOVE SE INTO THE IL RIVER VALLEY BY SUNSET WHILE A SHORT WAVE OVER IA MOVES INTO IL BY 00Z/7 PM. THIS MOVING INTO A WARM/HUMID AIR MASS WITH DEWPOINTS OF 70-75F TO DEVELOP ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DURING MID/LATE AFTERNOON AND CONTINUE UNTIL EARLY OR MID EVENING. MUCAPES OF 1500-2500 J/KG OVER SW CWA WHILE BULK SHEAR OF 25-35 KTS TO SUPPORT A FEW STRONG TO POSSIBLE SEVERE THUNDERSTORMS FROM 20Z-01Z. MVFR CEILINGS AND VSBYS POSSIBLE WITH THUNDERSTORMS FROM MID AFTERNOON INTO EARLY EVENING. COLD FRONT TO MOVE SE TO PIA BETWEEN 06Z-07Z AND REACH DEC AND CMI BY 09Z WITH SW WINDS UNDER 10 KTS SHIFTING NW OVERNIGHT AND NORTH TUE MORNING. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...SMITH LONG TERM...HJS AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1041 AM CDT MON JUL 20 2015 .UPDATE... ISSUED AT 1040 AM CDT MON JUL 20 2015 UPDATED THE FORECAST TO REMOVE PATCHY FOG THIS MORNING AND ALSO LOWERED CHANCES OF SHOWERS AND THUNDERSTORMS THIS MORNING. ANOTHER VERY WARM AND HUMID DAY EXPECTED WITH HIGHS IN THE MID TO UPPER 80S AND DEWPOINTS IN THE LOW TO MID 70S. HEAT INDICES THIS AFTERNOON TO PEAK IN THE UPPER 80S/LOWER 90S OVER CENTRAL IL AND MID TO UPPER 90S IN SOUTHEAST IL. MCS MOVING EAST OUT OF MO INTO SW AND WEST CENTRAL IL WITH LEADING EDGE OF SHOWERS/THUNDERSTORMS AS FAR EAST AS A BEARDSTOWN TO JACKSONVILLE TO EAST OF ST LOUIS LINE AND TRACKING EAST AT 35 MPH. RAP MODEL APPEARED TO HAVE BEST HANDLE ON THIS MCS AND IT SPREADS QPF EAST ACROSS AREAS FROM RUSHVILLE TO RANTOUL SOUTH DURING THE AFTERNOON. A COLD FRONT OVER CENTRAL PARTS OF WI/IA TO TRACK SE INTO NW IL LATER THIS AFTERNOON AND TO HAVE SHOWERS AND THUNDERSTORMS ALONG THIS BOUNDARY AS WELL MOVING INTO IL RIVER VALLEY LATE TODAY. SO WILL CONTINUE CHANCES OF SHOWERS AND THUNDESTORMS ACROSS CENTRAL/SE IL THIS AFTERNOON WITH HIGHEST CHANCES OF RAIN FROM I-72 SOUTH. SPC HAS SHIFTED SLIGHT RISK OF SEVERE STORMS THIS AFTERNOON/EVENING SOUTH OF CLAY...RICHLAND AND LAWERENCE COUNTIES. BUT MARGINAL RISK OF SEVERE STORMS COVERS CENTRAL IL CWA WITH 5-15% RISK OF HAIL AND DAMAGING WIND GUSTS. LOCALLY HEAVY RAINS AND FREQUENT LIGHTNING ALSO POSSIBLE WITH STRONGER STORMS FROM MID AFTERNOON INTO EARLY EVENING UNTIL SUNSET. && .SHORT TERM...(TODAY) ISSUED AT 318 AM CDT MON JUL 20 2015 CONVECTION THAT DEVELOPED NEAR ST.LOUIS LAST EVENING HAS SHIFTED SOUTHEAST INTO EXTREME SOUTHERN ILLINOIS EARLY THIS MORNING. THE STORMS ARC BACK TO THE NORTHWEST INTO PARTS OF WESTERN MO INTO NORTHEAST KS ALONG A FRONTAL BOUNDARY WHICH LOOKS TO BE THE MAIN FOCUS FOR ADDITIONAL DEVELOPMENT LATER TODAY. QUESTION BECOMES WHAT AFFECT FURTHER NORTH INTO OUR AREA IT MAY HAVE ON COVERAGE OF SHOWERS AND STORMS THIS AFTERNOON AND THIS EVENING AS ANOTHER COOL FRONT TRACKS ACROSS THE AREA FROM THE NORTHWEST LATE TODAY. USING THE TIMING AND COVERAGE OFF THE RAP MODEL WOULD SUGGEST A SLOWER ONSET OF PRECIP THAN EARLIER EXPECTED WITH THE BULK OF THE ACTIVITY TIED TO THE SURFACE BOUNDARY STRETCHING ACROSS MISSOURI THRU FAR SOUTHERN ILLINOIS...WITH A SECONDARY BAND OF SHOWERS AND STORMS SHOWING UP ALONG THE WEAK COOL FRONT WHICH IS FORECAST TO BE JUST TO OUR NORTHWEST LATE THIS AFTERNOON. THE HIGHER POPS WILL BE FOR MAINLY THIS AFTERNOON WITH ONLY LOW CHANCE POPS FOR PRECIP THIS MORNING ACROSS OUR WEST. MIXED LAYER CAPES OFF THE NAM MODEL FOR THIS AFTERNOON ARE EXPECTED TO RANGE FROM 1500-2000 J/KG WITH 0-6KM SHEAR VALUES OF 30 KTS. 700-500 MB LAPSE RATES NOT LOOKING THAT IMPRESSIVE THOUGH...BUT STILL CAN`T RULE OUT A STRONG TO LOCALLY SEVERE STORM THAT MAY BE CAPABLE OF PRODUCING GUSTY WINDS ALONG WITH HEAVY RAINFALL DURING THE MID TO LATE AFTERNOON HOURS. SPC HAS SHIFTED THE SLIGHT RISK FURTHER SOUTH AND WEST...CLOSER TO THE AFOREMENTIONED BOUNDARY OVER MISSOURI. WITH THE MAIN CONVECTIVE FRONT EXPECTED TO REMAIN TO OUR SOUTH...IT APPEARS THAT IS WHERE THE MORE CONCENTRATED AREA OF HEAVY RAINFALL WILL OCCUR...AS A RESULT...WILL NOT BE INCLUDING ANY FLASH FLOOD WATCH AT THIS TIME FOR OUR FAR WESTERN COUNTIES WHICH RECEIVED HEAVY RAINFALL LAST NIGHT. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 318 AM CDT MON JUL 20 2015 SEVERAL WEAK BOUNDARIES IN THE REGION AND WILL CONTINUE TO PROVIDE FOCUS FOR AN IMPULSE BRINGING PRECIP TODAY AND INTO TONIGHT. HOWEVER, MODELS ARE SHIFTING SOUTH SOMEWHAT AND FOR THE MOST PART, PUSH A COLD FRONT THROUGH THE STATE CONSIDERABLY FASTER TONIGHT. GFS AND ECMWF ARE LARGELY DRY AFTER 06Z, WITH THE NAM STILL STRUGGLING. HAVE PUSHED THE GRIDS CLOSER TO THAT SOLUTION, BUT THE SLOWING NATURE OF THE BOUNDARY TOWARDS TOMORROW MORNING...HAVE KEPT THE SLIGHTS ALONG AND SOUTH OF I-70, ALTHOUGH THOSE SMALL POPS MAY ALSO GET PULLED WITH SUBSEQUENT FORECASTS IF THE TRENDS CONTINUE. ELUSIVE DRY TREND IS BACK IN THE FORECAST FROM TOMORROW AFTERNOON THROUGH WED EVENING, AND MUCH OF THURSDAY. THURSDAY A WAVE DIVES INTO THE REGION AND ALTHOUGH MUCH OF THE PRECIP LOOKS TO PASS TO THE SW, SOME SMALL POPS ARE WORKING THEIR WAY INTO THE SUPERBLEND ALONG AND SW OF A LINE FROM HAVANA TO LAWRENCEVILLE. CONCERNED WITH THE LOOK OF THE MODELS IN THAT TIME FRAME ARE NOT PROPERLY REPRESENTED IN THE SUPERBLEND JUST YET. GFS IS MORE AGGRESSIVE WITH THE QPF ON THURSDAY NIGHT OVER IL...AND ECMWF PASSES THE WAVE ALOFT IN THE SAME TIME FRAME WITH LITTLE TO SHOW AT THE SFC. EXPECT SOME CHANGES IN THIS PORTION OF THE FORECAST. WARMING TREND CONTINUES THROUGH THE END OF THE WEEK, WITH THE HIGHEST TEMPS IN THE FORECAST NEXT WEEKEND AGAIN. WITH THE WARM TEMPS, A RIDGE BUILDS IN THE DESERT SW AND SOUTHERN PLAINS. ILLINOIS HAS VERY LITTLE IN THE WAY OF STEERING FLOW AND MODELS ARE A BIT MORE SCATTERED WITH WEAK WAVES...WITH THE GFS AND ECMWF DIVERGING AT THE WEEKEND DEALING WITH A TROF PASSING ACROSS THE NRN TIER OF THE CONUS. FOR NOW, SLIGHT/CHANCE POPS THROUGH THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 605 AM CDT MON JUL 20 2015 IFR TO VLIFR CONDITIONS IN FOG EXPECTED TO QUICKLY IMPROVE OVER THE NEXT COUPLE OF HOURS. ONCE THE FOG LIFTS...WE EXPECT VFR CONDITIONS THRU THIS FORECAST PERIOD. A COLD FRONT TO OUR NORTHWEST EARLY THIS MORNING WILL PUSH ACROSS THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. MEANWHILE...A BAND OF SHOWERS AND STORMS WAS MOVING ACROSS IOWA AND MISSOURI AND MAY PUSH INTO THE AREA BY LATE MORNING OR EARLY AFTERNOON...HOWEVER MODELS NOT VERY AGREEABLE AS TO WHETHER THE BAND WILL HOLD TOGETHER BEFORE MOVING INTO OUR AREA. FOR NOW WILL CONTINUE WITH THE VCTS OVER OUR WESTERN AREAS BY 16Z...AND MOVING INTO THE EASTERN TAF LOCATIONS BY 18 OR 19Z. THE RAIN THREAT SHOULD END FROM NORTHWEST TO SOUTHEAST THIS EVENING AS THE FRONT SHIFTS AWAY FROM OUR AREA. SURFACE WINDS WILL BE SOUTHWEST AT 8 TO 13 KTS TODAY AND THEN SHIFT INTO A LIGHT NORTHWEST DIRECTION AFTER FROPA LATER THIS EVENING AND DURING THE OVERNIGHT HOURS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
615 AM CDT MON JUL 20 2015 .SHORT TERM...(TODAY) ISSUED AT 318 AM CDT MON JUL 20 2015 CONVECTION THAT DEVELOPED NEAR ST.LOUIS LAST EVENING HAS SHIFTED SOUTHEAST INTO EXTREME SOUTHERN ILLINOIS EARLY THIS MORNING. THE STORMS ARC BACK TO THE NORTHWEST INTO PARTS OF WESTERN MO INTO NORTHEAST KS ALONG A FRONTAL BOUNDARY WHICH LOOKS TO BE THE MAIN FOCUS FOR ADDITIONAL DEVELOPMENT LATER TODAY. QUESTION BECOMES WHAT AFFECT FURTHER NORTH INTO OUR AREA IT MAY HAVE ON COVERAGE OF SHOWERS AND STORMS THIS AFTERNOON AND THIS EVENING AS ANOTHER COOL FRONT TRACKS ACROSS THE AREA FROM THE NORTHWEST LATE TODAY. USING THE TIMING AND COVERAGE OFF THE RAP MODEL WOULD SUGGEST A SLOWER ONSET OF PRECIP THAN EARLIER EXPECTED WITH THE BULK OF THE ACTIVITY TIED TO THE SURFACE BOUNDARY STRETCHING ACROSS MISSOURI THRU FAR SOUTHERN ILLINOIS...WITH A SECONDARY BAND OF SHOWERS AND STORMS SHOWING UP ALONG THE WEAK COOL FRONT WHICH IS FORECAST TO BE JUST TO OUR NORTHWEST LATE THIS AFTERNOON. THE HIGHER POPS WILL BE FOR MAINLY THIS AFTERNOON WITH ONLY LOW CHANCE POPS FOR PRECIP THIS MORNING ACROSS OUR WEST. MIXED LAYER CAPES OFF THE NAM MODEL FOR THIS AFTERNOON ARE EXPECTED TO RANGE FROM 1500-2000 J/KG WITH 0-6KM SHEAR VALUES OF 30 KTS. 700-500 MB LAPSE RATES NOT LOOKING THAT IMPRESSIVE THOUGH...BUT STILL CAN`T RULE OUT A STRONG TO LOCALLY SEVERE STORM THAT MAY BE CAPABLE OF PRODUCING GUSTY WINDS ALONG WITH HEAVY RAINFALL DURING THE MID TO LATE AFTERNOON HOURS. SPC HAS SHIFTED THE SLIGHT RISK FURTHER SOUTH AND WEST...CLOSER TO THE AFOREMENTIONED BOUNDARY OVER MISSOURI. WITH THE MAIN CONVECTIVE FRONT EXPECTED TO REMAIN TO OUR SOUTH...IT APPEARS THAT IS WHERE THE MORE CONCENTRATED AREA OF HEAVY RAINFALL WILL OCCUR...AS A RESULT...WILL NOT BE INCLUDING ANY FLASH FLOOD WATCH AT THIS TIME FOR OUR FAR WESTERN COUNTIES WHICH RECEIVED HEAVY RAINFALL LAST NIGHT. .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 318 AM CDT MON JUL 20 2015 SEVERAL WEAK BOUNDARIES IN THE REGION AND WILL CONTINUE TO PROVIDE FOCUS FOR AN IMPULSE BRINGING PRECIP TODAY AND INTO TONIGHT. HOWEVER, MODELS ARE SHIFTING SOUTH SOMEWHAT AND FOR THE MOST PART, PUSH A COLD FRONT THROUGH THE STATE CONSIDERABLY FASTER TONIGHT. GFS AND ECMWF ARE LARGELY DRY AFTER 06Z, WITH THE NAM STILL STRUGGLING. HAVE PUSHED THE GRIDS CLOSER TO THAT SOLUTION, BUT THE SLOWING NATURE OF THE BOUNDARY TOWARDS TOMORROW MORNING...HAVE KEPT THE SLIGHTS ALONG AND SOUTH OF I-70, ALTHOUGH THOSE SMALL POPS MAY ALSO GET PULLED WITH SUBSEQUENT FORECASTS IF THE TRENDS CONTINUE. ELUSIVE DRY TREND IS BACK IN THE FORECAST FROM TOMORROW AFTERNOON THROUGH WED EVENING, AND MUCH OF THURSDAY. THURSDAY A WAVE DIVES INTO THE REGION AND ALTHOUGH MUCH OF THE PRECIP LOOKS TO PASS TO THE SW, SOME SMALL POPS ARE WORKING THEIR WAY INTO THE SUPERBLEND ALONG AND SW OF A LINE FROM HAVANA TO LAWRENCEVILLE. CONCERNED WITH THE LOOK OF THE MODELS IN THAT TIME FRAME ARE NOT PROPERLY REPRESENTED IN THE SUPERBLEND JUST YET. GFS IS MORE AGGRESSIVE WITH THE QPF ON THURSDAY NIGHT OVER IL...AND ECMWF PASSES THE WAVE ALOFT IN THE SAME TIME FRAME WITH LITTLE TO SHOW AT THE SFC. EXPECT SOME CHANGES IN THIS PORTION OF THE FORECAST. WARMING TREND CONTINUES THROUGH THE END OF THE WEEK, WITH THE HIGHEST TEMPS IN THE FORECAST NEXT WEEKEND AGAIN. WITH THE WARM TEMPS, A RIDGE BUILDS IN THE DESERT SW AND SOUTHERN PLAINS. ILLINOIS HAS VERY LITTLE IN THE WAY OF STEERING FLOW AND MODELS ARE A BIT MORE SCATTERED WITH WEAK WAVES...WITH THE GFS AND ECMWF DIVERGING AT THE WEEKEND DEALING WITH A TROF PASSING ACROSS THE NRN TIER OF THE CONUS. FOR NOW, SLIGHT/CHANCE POPS THROUGH THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 605 AM CDT MON JUL 20 2015 IFR TO VLIFR CONDITIONS IN FOG EXPECTED TO QUICKLY IMPROVE OVER THE NEXT COUPLE OF HOURS. ONCE THE FOG LIFTS...WE EXPECT VFR CONDITIONS THRU THIS FORECAST PERIOD. A COLD FRONT TO OUR NORTHWEST EARLY THIS MORNING WILL PUSH ACROSS THE AREA LATE THIS AFTERNOON OR EARLY THIS EVENING. MEANWHILE...A BAND OF SHOWERS AND STORMS WAS MOVING ACROSS IOWA AND MISSOURI AND MAY PUSH INTO THE AREA BY LATE MORNING OR EARLY AFTERNOON...HOWEVER MODELS NOT VERY AGREEABLE AS TO WHETHER THE BAND WILL HOLD TOGETHER BEFORE MOVING INTO OUR AREA. FOR NOW WILL CONTINUE WITH THE VCTS OVER OUR WESTERN AREAS BY 16Z...AND MOVING INTO THE EASTERN TAF LOCATIONS BY 18 OR 19Z. THE RAIN THREAT SHOULD END FROM NORTHWEST TO SOUTHEAST THIS EVENING AS THE FRONT SHIFTS AWAY FROM OUR AREA. SURFACE WINDS WILL BE SOUTHWEST AT 8 TO 13 KTS TODAY AND THEN SHIFT INTO A LIGHT NORTHWEST DIRECTION AFTER FROPA LATER THIS EVENING AND DURING THE OVERNIGHT HOURS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
319 AM CDT MON JUL 20 2015 .SHORT TERM...(TODAY) ISSUED AT 318 AM CDT MON JUL 20 2015 CONVECTION THAT DEVELOPED NEAR ST.LOUIS LAST EVENING HAS SHIFTED SOUTHEAST INTO EXTREME SOUTHERN ILLINOIS EARLY THIS MORNING. THE STORMS ARC BACK TO THE NORTHWEST INTO PARTS OF WESTERN MO INTO NORTHEAST KS ALONG A FRONTAL BOUNDARY WHICH LOOKS TO BE THE MAIN FOCUS FOR ADDITIONAL DEVELOPMENT LATER TODAY. QUESTION BECOMES WHAT AFFECT FURTHER NORTH INTO OUR AREA IT MAY HAVE ON COVERAGE OF SHOWERS AND STORMS THIS AFTERNOON AND THIS EVENING AS ANOTHER COOL FRONT TRACKS ACROSS THE AREA FROM THE NORTHWEST LATE TODAY. USING THE TIMING AND COVERAGE OFF THE RAP MODEL WOULD SUGGEST A SLOWER ONSET OF PRECIP THAN EARLIER EXPECTED WITH THE BULK OF THE ACTIVITY TIED TO THE SURFACE BOUNDARY STRETCHING ACROSS MISSOURI THRU FAR SOUTHERN ILLINOIS...WITH A SECONDARY BAND OF SHOWERS AND STORMS SHOWING UP ALONG THE WEAK COOL FRONT WHICH IS FORECAST TO BE JUST TO OUR NORTHWEST LATE THIS AFTERNOON. THE HIGHER POPS WILL BE FOR MAINLY THIS AFTERNOON WITH ONLY LOW CHANCE POPS FOR PRECIP THIS MORNING ACROSS OUR WEST. MIXED LAYER CAPES OFF THE NAM MODEL FOR THIS AFTERNOON ARE EXPECTED TO RANGE FROM 1500-2000 J/KG WITH 0-6KM SHEAR VALUES OF 30 KTS. 700-500 MB LAPSE RATES NOT LOOKING THAT IMPRESSIVE THOUGH...BUT STILL CAN`T RULE OUT A STRONG TO LOCALLY SEVERE STORM THAT MAY BE CAPABLE OF PRODUCING GUSTY WINDS ALONG WITH HEAVY RAINFALL DURING THE MID TO LATE AFTERNOON HOURS. SPC HAS SHIFTED THE SLIGHT RISK FURTHER SOUTH AND WEST...CLOSER TO THE AFOREMENTIONED BOUNDARY OVER MISSOURI. WITH THE MAIN CONVECTIVE FRONT EXPECTED TO REMAIN TO OUR SOUTH...IT APPEARS THAT IS WHERE THE MORE CONCENTRATED AREA OF HEAVY RAINFALL WILL OCCUR...AS A RESULT...WILL NOT BE INCLUDING ANY FLASH FLOOD WATCH AT THIS TIME FOR OUR FAR WESTERN COUNTIES WHICH RECEIVED HEAVY RAINFALL LAST NIGHT. && .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 318 AM CDT MON JUL 20 2015 SEVERAL WEAK BOUNDARIES IN THE REGION AND WILL CONTINUE TO PROVIDE FOCUS FOR AN IMPULSE BRINGING PRECIP TODAY AND INTO TONIGHT. HOWEVER, MODELS ARE SHIFTING SOUTH SOMEWHAT AND FOR THE MOST PART, PUSH A COLD FRONT THROUGH THE STATE CONSIDERABLY FASTER TONIGHT. GFS AND ECMWF ARE LARGELY DRY AFTER 06Z, WITH THE NAM STILL STRUGGLING. HAVE PUSHED THE GRIDS CLOSER TO THAT SOLUTION, BUT THE SLOWING NATURE OF THE BOUNDARY TOWARDS TOMORROW MORNING...HAVE KEPT THE SLIGHTS ALONG AND SOUTH OF I-70, ALTHOUGH THOSE SMALL POPS MAY ALSO GET PULLED WITH SUBSEQUENT FORECASTS IF THE TRENDS CONTINUE. ELUSIVE DRY TREND IS BACK IN THE FORECAST FROM TOMORROW AFTERNOON THROUGH WED EVENING, AND MUCH OF THURSDAY. THURSDAY A WAVE DIVES INTO THE REGION AND ALTHOUGH MUCH OF THE PRECIP LOOKS TO PASS TO THE SW, SOME SMALL POPS ARE WORKING THEIR WAY INTO THE SUPERBLEND ALONG AND SW OF A LINE FROM HAVANA TO LAWRENCEVILLE. CONCERNED WITH THE LOOK OF THE MODELS IN THAT TIME FRAME ARE NOT PROPERLY REPRESENTED IN THE SUPERBLEND JUST YET. GFS IS MORE AGGRESSIVE WITH THE QPF ON THURSDAY NIGHT OVER IL...AND ECMWF PASSES THE WAVE ALOFT IN THE SAME TIME FRAME WITH LITTLE TO SHOW AT THE SFC. EXPECT SOME CHANGES IN THIS PORTION OF THE FORECAST. WARMING TREND CONTINUES THROUGH THE END OF THE WEEK, WITH THE HIGHEST TEMPS IN THE FORECAST NEXT WEEKEND AGAIN. WITH THE WARM TEMPS, A RIDGE BUILDS IN THE DESERT SW AND SOUTHERN PLAINS. ILLINOIS HAS VERY LITTLE IN THE WAY OF STEERING FLOW AND MODELS ARE A BIT MORE SCATTERED WITH WEAK WAVES...WITH THE GFS AND ECMWF DIVERGING AT THE WEEKEND DEALING WITH A TROF PASSING ACROSS THE NRN TIER OF THE CONUS. FOR NOW, SLIGHT/CHANCE POPS THROUGH THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1154 PM CDT SUN JUL 19 2015 SKIES HAVE BECOME CLEAR ACROSS THE AREA AND WITH WINDS BECOMING LIGHT OVERNIGHT...EXPECTING LIGHT FOG TO DEVELOP AT ALL SITES. SO WILL START ALL SITES WITH FOG AND CONTINUE THAT UNTIL THE MORNING HOURS AROUND 14Z. THEN DURING THE MORNING HOURS...BELIEVE CONVECTION WILL BEGIN TO ADVECT INTO THE AREA FROM THE WEST AS AN MCS FROM THE PLAINS GETS INTO THE AREA...SOMETIME AFTER 15Z. THE THREAT OF CONVECTION WILL OCCUR WITH THE MORNING STUFF AND THEN CONTINUE INTO THE AFTERNOON AFTER SOME HEATING AND ANOTHER WAVE MOVING THROUGH THE AREA. THIS LAST WAVE SHOULD PUSH OUT OF THE AREA DURING THE EVENING BRINGING DRY WEATHER TO THE AREA FOR THE REST OF THE FORECAST PERIOD. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT AND THEN BECOME SOUTHWESTERLY AGAIN TOMORROW...THEN FOLLOWED BY LIGHT AND VARIABLE AGAIN TOMORROW EVENING AS HIGH PRESSURE BEGINS TO BUILD INTO THE AREA. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
136 PM EDT MON JUL 20 2015 .SYNOPSIS... ISSUED AT 134 PM EDT MON JUL 20 2015 HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION TODAY. A WEAK COLD FRONT WILL APPROACH LATE THIS AFTERNOON AND MOVE ACROSS THE AREA TONIGHT. THERE WILL BE A SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS NEAR THIS FRONT. SKIES WILL BE PARTLY TO MOSTLY CLOUDY ACROSS THE AREA THIS AFTERNOON. HIGH TEMPERATURES WILL BE IN THE LOWER TO MIDDLE 80S. LOWS TONIGHT WILL BE IN THE LOWER AND MIDDLE 60S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 349 AM EDT MON JUL 20 2015 WEAK HIGH PRESSURE WILL MOVE EAST TODAY WHILE SHORT WAVE AND ASSOCIATED COLD FRONT APPROACH LATE THIS AFTERNOON AND MOVE THROUGH CWA TONIGHT. FORCING AND MOISTURE FLUX WEAK WITH THIS SYSTEM BUT ENOUGH AMBIENT MOISTURE AND WEAK LIFT TO SUPPORT CHANCE POPS FROM LATE THIS AFTERNOON THROUGH TONIGHT. RAP AND HRRR SEEM TO HAVE BEST HANDLE ON UPSTREAM CONVECTION EARLY THIS MORNING. BOTH MODELS WEAKEN CONVECTION AS IT MOVES EAST TODAY BUT STILL SHOW SOME SCATTERED DEVELOPMENT IN OUR AREA BY LATE AFTERNOON AND THROUGH THE EVENING. SEVERE WEATHER THREAT LOOKS MINIMAL AS MUCAPES ONLY IN THE 1-2K J/KG RANGE AT BEST AND 0-3KM SHEAR BETWEEN 20 AND 30KTS. LACK OF STRONG CONVERGENCE AND OVERNIGHT TIMING SHOULD ALSO LIMIT DEVELOPMENT. COLD FRONT WILL PUSH SOUTH BY EARLY TUESDAY MORNING ENDING PCPN CHANCES FROM NORTH TO SOUTH OVERNIGHT WITH EVEN DRIER AIR WORKING IN. && .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 349 AM EDT MON JUL 20 2015 A SECOND SURGE OF COOL AIR WILL SPREAD ACROSS THE REGION BEHIND A COLD FRONT EARLY TUESDAY. A SURFACE HIGH PRESSURE SYSTEM WILL BE OVER THE REGION FOR THE NEXT SEVERAL DAYS. TEMPERATURES WILL FALL WELL BELOW NORMAL BEHIND THE COOL FRONT TUESDAY NIGHT...FOLLOWED BY A GRADUAL MODERATION LATER IN THE WEEK. THE SUBTROPICAL RIDGE WILL EXTEND WELL INLAND...INTO THE SOUTHERN PLAINS... AND EVENTUALLY BUILD FURTHER WEST INTO THE SOUTHWEST CONUS. HIGHS HERE WILL BE IN THE 70S TUESDAY AND WEDNESDAY...RISING INTO THE 80S BY FRIDAY AS A PORTION OF THE UPPER LEVEL RIDGE TEMPORARILY BUILDS INTO THE AREA. CONDITIONS SHOULD BE DRY THROUGH FRIDAY...BUT SOME ENERGY SHOULD BE ABLE TO TOP THE UPPER LEVEL RIDGE AND BRING A CHANCE FOR THUNDERSTORMS THIS COMING WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 133 PM EDT MON JUL 20 2015 VFR CONDITIONS EXPECTED THROUGH THE TAF PD. CONTINUED WITH VCSH MENTION AT KSBN AS COLD FRONT APPROACHES FROM THE WEST...HOWEVER PUSHED TIMING BACK A BIT AND CONFIDENCE ON ANY PRECIPITATION IS CONTINUING TO LOWER. FRONT WILL SLIDE THROUGH THE TERMINALS BETWEEN 06Z AND 12Z...WITH WINDS VEERING NORTHERLY. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...NG VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
631 AM EDT MON JUL 20 2015 .SYNOPSIS... ISSUED AT 350 AM EDT MON JUL 20 2015 HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION TODAY. A WEAK COLD FRONT WILL APPROACH LATE THIS AFTERNOON AND MOVE ACROSS THE AREA TONIGHT. THERE WILL BE A SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS NEAR THIS FRONT. OTHERWISE TODAY WILL BEGIN MOSTLY SUNNY WITH INCREASING CLOUDS THIS AFTERNOON. HIGH TEMPERATURES WILL BE IN THE LOWER TO MIDDLE 80S. LOWS TONIGHT WILL BE IN THE LOWER AND MIDDLE 60S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 349 AM EDT MON JUL 20 2015 WEAK HIGH PRESSURE WILL MOVE EAST TODAY WHILE SHORT WAVE AND ASSOCIATED COLD FRONT APPROACH LATE THIS AFTERNOON AND MOVE THROUGH CWA TONIGHT. FORCING AND MOISTURE FLUX WEAK WITH THIS SYSTEM BUT ENOUGH AMBIENT MOISTURE AND WEAK LIFT TO SUPPORT CHANCE POPS FROM LATE THIS AFTERNOON THROUGH TONIGHT. RAP AND HRRR SEEM TO HAVE BEST HANDLE ON UPSTREAM CONVECTION EARLY THIS MORNING. BOTH MODELS WEAKEN CONVECTION AS IT MOVES EAST TODAY BUT STILL SHOW SOME SCATTERED DEVELOPMENT IN OUR AREA BY LATE AFTERNOON AND THROUGH THE EVENING. SEVERE WEATHER THREAT LOOKS MINIMAL AS MUCAPES ONLY IN THE 1-2K J/KG RANGE AT BEST AND 0-3KM SHEAR BETWEEN 20 AND 30KTS. LACK OF STRONG CONVERGENCE AND OVERNIGHT TIMING SHOULD ALSO LIMIT DEVELOPMENT. COLD FRONT WILL PUSH SOUTH BY EARLY TUESDAY MORNING ENDING PCPN CHANCES FROM NORTH TO SOUTH OVERNIGHT WITH EVEN DRIER AIR WORKING IN. && .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 349 AM EDT MON JUL 20 2015 A SECOND SURGE OF COOL AIR WILL SPREAD ACROSS THE REGION BEHIND A COLD FRONT EARLY TUESDAY. A SURFACE HIGH PRESSURE SYSTEM WILL BE OVER THE REGION FOR THE NEXT SEVERAL DAYS. TEMPERATURES WILL FALL WELL BELOW NORMAL BEHIND THE COOL FRONT TUESDAY NIGHT...FOLLOWED BY A GRADUAL MODERATION LATER IN THE WEEK. THE SUBTROPICAL RIDGE WILL EXTEND WELL INLAND...INTO THE SOUTHERN PLAINS... AND EVENTUALLY BUILD FURTHER WEST INTO THE SOUTHWEST CONUS. HIGHS HERE WILL BE IN THE 70S TUESDAY AND WEDNESDAY...RISING INTO THE 80S BY FRIDAY AS A PORTION OF THE UPPER LEVEL RIDGE TEMPORARILY BUILDS INTO THE AREA. CONDITIONS SHOULD BE DRY THROUGH FRIDAY...BUT SOME ENERGY SHOULD BE ABLE TO TOP THE UPPER LEVEL RIDGE AND BRING A CHANCE FOR THUNDERSTORMS THIS COMING WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 630 AM EDT MON JUL 20 2015 VFR CONDITIONS GENERALLY EXPECTED THROUGH THE PERIOD BUT POCKETS OF GROUND FOG ARE POSSIBLE THROUGH 13Z. A WEAK COLD FRONT WILL MOVE THROUGH TONIGHT. THERE IS A SMALL CHANCE FOR SHOWERS OR THUNDERSTORMS NEAR THIS FRONT BUT LIFT IS WEAK AND CHANCES ARE TOO LOW FOR INCLUSION IN TAF AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
350 AM EDT MON JUL 20 2015 .SYNOPSIS... ISSUED AT 350 AM EDT MON JUL 20 2015 HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION TODAY. A WEAK COLD FRONT WILL APPROACH LATE THIS AFTERNOON AND MOVE ACROSS THE AREA TONIGHT. THERE WILL BE A SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS NEAR THIS FRONT. OTHERWISE TODAY WILL BEGIN MOSTLY SUNNY WITH INCREASING CLOUDS THIS AFTERNOON. HIGH TEMPERATURES WILL BE IN THE LOWER TO MIDDLE 80S. LOWS TONIGHT WILL BE IN THE LOWER AND MIDDLE 60S. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 349 AM EDT MON JUL 20 2015 WEAK HIGH PRESSURE WILL MOVE EAST TODAY WHILE SHORT WAVE AND ASSOCIATED COLD FRONT APPROACH LATE THIS AFTERNOON AND MOVE THROUGH CWA TONIGHT. FORCING AND MOISTURE FLUX WEAK WITH THIS SYSTEM BUT ENOUGH AMBIENT MOISTURE AND WEAK LIFT TO SUPPORT CHANCE POPS FROM LATE THIS AFTERNOON THROUGH TONIGHT. RAP AND HRRR SEEM TO HAVE BEST HANDLE ON UPSTREAM CONVECTION EARLY THIS MORNING. BOTH MODELS WEAKEN CONVECTION AS IT MOVES EAST TODAY BUT STILL SHOW SOME SCATTERED DEVELOPMENT IN OUR AREA BY LATE AFTERNOON AND THROUGH THE EVENING. SEVERE WEATHER THREAT LOOKS MINIMAL AS MUCAPES ONLY IN THE 1-2K J/KG RANGE AT BEST AND 0-3KM SHEAR BETWEEN 20 AND 30KTS. LACK OF STRONG CONVERGENCE AND OVERNIGHT TIMING SHOULD ALSO LIMIT DEVELOPMENT. COLD FRONT WILL PUSH SOUTH BY EARLY TUESDAY MORNING ENDING PCPN CHANCES FROM NORTH TO SOUTH OVERNIGHT WITH EVEN DRIER AIR WORKING IN. && .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 349 AM EDT MON JUL 20 2015 A SECOND SURGE OF COOL AIR WILL SPREAD ACROSS THE REGION BEHIND A COLD FRONT EARLY TUESDAY. A SURFACE HIGH PRESSURE SYSTEM WILL BE OVER THE REGION FOR THE NEXT SEVERAL DAYS. TEMPERATURES WILL FALL WELL BELOW NORMAL BEHIND THE COOL FRONT TUESDAY NIGHT...FOLLOWED BY A GRADUAL MODERATION LATER IN THE WEEK. THE SUBTROPICAL RIDGE WILL EXTEND WELL INLAND...INTO THE SOUTHERN PLAINS... AND EVENTUALLY BUILD FURTHER WEST INTO THE SOUTHWEST CONUS. HIGHS HERE WILL BE IN THE 70S TUESDAY AND WEDNESDAY...RISING INTO THE 80S BY FRIDAY AS A PORTION OF THE UPPER LEVEL RIDGE TEMPORARILY BUILDS INTO THE AREA. CONDITIONS SHOULD BE DRY THROUGH FRIDAY...BUT SOME ENERGY SHOULD BE ABLE TO TOP THE UPPER LEVEL RIDGE AND BRING A CHANCE FOR THUNDERSTORMS THIS COMING WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 117 AM EDT MON JUL 20 2015 VFR CONDITIONS GENERALLY EXPECTED THROUGH THE PERIOD BUT POCKETS OF GROUND FOG ARE POSSIBLE BRIEFLY AROUND DAYBREAK. A WEAK COLD FRONT WILL MOVE THROUGH TONIGHT. THERE IS A SMALL CHANCE FOR SHOWERS OR THUNDERSTORMS NEAR THIS FRONT BUT CHANCES ARE TOO LOW FOR INCLUSION IN TAF AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...LASHLEY LONG TERM...SKIPPER AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
124 AM EDT MON JUL 20 2015 .SYNOPSIS... ISSUED AT 120 AM EDT MON JUL 20 2015 HIGH PRESSURE WILL QUICKLY MOVE ACROSS THE REGION TODAY. A WEAK COLD FRONT WILL APPROACH LATE THIS AFTERNOON AND MOVE ACROSS THE AREA TONIGHT. THERE WILL BE A SMALL CHANCE FOR SHOWERS AND THUNDERSTORMS NEAR THIS FRONT. OTHERWISE TODAY WILL BEGIN MOSTLY SUNNY WITH INCREASING CLOUDS THIS AFTERNOON. HIGH TEMPERATURES WILL BE IN THE LOWER TO MIDDLE 80S. LOWS TONIGHT WILL BE IN THE LOWER AND MIDDLE 60S. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 343 PM EDT SUN JUL 19 2015 COLD FRONT IS CURRENTLY PUSHING SE THROUGH THE FORECAST AREA AS OF 1930Z. SCATTERED CONVECTION HAS DEVELOPED AHEAD OF THE FRONT FROM FORT WAYNE EASTWARD TO FINDLAY...WHERE SBCAPES HAVE REACHED 3000 TO 4000 J/KG. SHEAR IS WEAK WITH 500MB SPEED MAX WELL NORTH OF THE AREA. FRONTAL FORCING IS WEAK AS WELL...WITH BETTER VEERING WINDS AND LOWER TEMPS/DEWPOINTS WELL TO THE NORTHWEST. W/ MARGINAL LAPSE RATES AND WEAK FORCING/SHEAR...EXPECT SEVERE THREAT TO BE FAIRLY MINIMAL THROUGH THE REST OF THE AFTERNOON/EARLY EVENING. ASIDE FROM A LOW DAMAGING WIND THREAT...HEAVY RAINFALL IS THE PRIMARY THREAT GOING FORWARD...W/ PWATS MAXING OUT NEAR 2.00 INCHES SOUTH OF THE BOUNDARY. AS FAR AS POPS GO...KEPT THEM IN THE CHANCE RANGE THROUGH 00Z...WITH A GRADUAL DIMINISH FROM NORTH TO SOUTH AND THE FRONT CONTINUES TO PUSH THROUGH THE AREA. THERE MAY BE AN UPTICK IN COVERAGE BETWEEN 21Z AND 00Z AS FRONTAL FORCING BECOMES A BIT STRONGER...HOWEVER HI RES GUIDANCE...PARTICULARLY RECENT HRRR RUNS...HAVE SUGGESTED MINIMAL ADDITIONAL COVERAGE THROUGH THIS TIME PERIOD. TAPERED OFF TO DRY CONDITIONS AFTER 06Z...WITH CLEARING SKIES WORKING SOUTH THROUGH THE FORECAST AREA AS WELL. LOWS SHOULD RANGE FROM THE LOW TO MID 60S ACROSS THE AREA. HIGH PRESSURE WILL MOVE QUICKLY ACROSS THE GREAT LAKES REGION LATE OVERNIGHT THROUGH THE DAY MONDAY...AS THE FRONTAL BOUNDARY LINGERS JUST SOUTH OF THE AREA. CLOUD COVER WILL INCREASE FROM THE WEST THROUGH THE DAY AS A SHORTWAVE TRACKS EAST FROM KANSAS TOWARDS THE OHIO VALLEY...AND ANOTHER COLD FRONT DROPS TOWARD THE AREA FROM THE NORTHWEST. THIS MAY SPARK AN AFTERNOON THUNDERSTORM...MAINLY ACROSS THE WEST/SOUTHWEST PART OF THE FORECAST AREA...AS VERY WEAK DESTABILIZATION OCCURS...MAINLY SOUTHWEST OF THE FORECAST AREA. CONFIDENCE IS LOW AT ANY PRECIP COVERAGE BEFORE 00Z...HOWEVER FOR COLLABORATION SAKE...ADDED SLIGHT CHANCE POPS WEST/SOUTHWEST AFTER 21Z. HIGH TEMPS SHOULD REMAIN IN THE LOW TO MID 80S. WENT SLIGHTLY COOLER THAN PREVIOUS FCST GIVEN EXPECTED CLOUD COVER AHEAD OF UPSTREAM SYSTEMS. && .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 343 PM EDT SUN JUL 19 2015 DIFFUSE CDFNT MOVG THROUGH OUR AREA TODAY WILL STALL OUT OVER THE OH VALLEY/MID MS VALLEY TONIGHT WITH REMNANT BOUNDARY AND ASSOCIATED MOISTURE POOL LIFTING BACK N-NE MONDAY AS SHRTWV AND ASSOCIATED CDFNT OVER SASK MOVES SE INTO THE UPR GRTLKS AND SECOND VORT MAX OVER WY GETS INGESTED INTO THE WRLYS AND MOVES TO THE MID MS VALLEY. COMBINATION OF THESE TWO FORCING MECHANISMS AND RETURN MOISTURE/DESTABILIZATION MAY BE SUFFICIENT TO CAUSE SCT TSTMS IN OUR AREA MONDAY NIGHT... CONTINUED WITH HIGHEST POPS ACROSS SOUTHERN PORTION OF THE CWA CLOSER TO THE TRACK OF THE SRN STREAM VORT MAX. THE NRN STREAM SHRTWV MOVG THROUGH THE UPR GRTLKS WILL RESULT IN STRENGTHENING OF THE ONTARIO UPR LOW AND AMPLIFICATION OF THE FLOW ALOFT ACROSS THE CENTRAL CONUS/CANADA. THIS WILL ALLOW A RATHER STRONG SFC HIGH TO DRIFT SLOWLY SE-E FROM THE NRN PLAINS ACROSS THE GRTLKS PROVIDING FAIR WX ACROSS OUR AREA FOR THE REMAINDER OF THE WORK-WEEK. BY THE WEEKEND... SFC HIGH SHOULD MOVE TO THE ERN CONUS WITH MOISTURE/INSTABILITY/WAA RETURNING TO OUR AREA AND COMBINING WITH WK SHRTWV`S MOVG OVER THE TOP OF THE SRN PLAINS/ROCKIES UPR HIGH BRINGING A CHC OF TSTMS BACK TO OUR AREA. THE NW FLOW ALOFT SHOULD KEEP TEMPS BLO NORMAL THROUGH THE WORKWEEK...PSBLY RISING BACK ABOVE NORMAL NEXT WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 117 AM EDT MON JUL 20 2015 VFR CONDITIONS GENERALLY EXPECTED THROUGH THE PERIOD BUT POCKETS OF GROUND FOG ARE POSSIBLE BRIEFLY AROUND DAYBREAK. A WEAK COLD FRONT WILL MOVE THROUGH TONIGHT. THERE IS A SMALL CHANCE FOR SHOWERS OR THUNDERSTORMS NEAR THIS FRONT BUT CHANCES ARE TOO LOW FOR INCLUSION IN TAF AT THIS TIME. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...LASHLEY SHORT TERM...NG LONG TERM...JT AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1139 PM MDT SUN JUL 19 2015 .UPDATE... ISSUED AT 825 PM MDT SUN JUL 19 2015 UPDATED GRIDS AND ZONES DUE TO CANCELLING SEVERE THUNDERSTORM WATCH 444. ALSO CANCELLED THE FLASH FLOOD WATCH DUE TO STRONGER STORMS WEAKENING AND MOVING OUT OF THE FA. DO NOT EXPECT ANY ADDITIONAL STORMS OVERNIGHT THAT WOULD HAVE HEAVY RAINFALL POTENTIAL. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 157 PM MDT SUN JUL 19 2015 COMPLICATED SURFACE PATTERN IN PLACE. EITHER OR SOME COMBINATION OF A LEFT OVER OUTFLOW BOUNDARY...SURFACE TROUGH RETREATING FRONT IS NOW NEAR OR OVER THE SOUTHERN PORTION OF THE AREA. SHORTWAVE TROUGH IS STARTING TO MOVE THROUGH FROM THE SOUTH AND WEST. A WEAK RIGHT REAR QUADRANT IS MOVING THROUGH THE AREA DURING THE NIGHT. THE RAP IS CATCHING THE SURFACE WIND FIELD THE BEST RIGHT NOW. IT AND THE HRRR WHICH DID WELL FROM LAST NIGHT...IS CATCHING THE WIND FIELD AND THE CURRENT AND EXPECTED THUNDERSTORM DEVELOPMENT VERY WELL RIGHT NOW. STORMS WILL CONTINUE INCREASE IN COVERAGE AND INTENSITY THROUGH TONIGHT AS STORMS MOVE ACROSS THE AREA THROUGH THE OVERNIGHT HOURS. VERY UNSTABLE AIR MASS AND EXPECT SOME OF THESE STORMS TO BECOME SEVERE. HOWEVER THE BIGGEST THREAT WILL BE THE HEAVY RAINFALL AND POSSIBLE FLASH FLOODING. AIR MASS REMAINS VERY MOIST THROUGH A DEEP DEPTH. WHERE THE THREAT FOR HEAVY RAINFALL MATCHES UP WITH WHERE HEAVY RAINFALL/SOME FLASH FLOODING OCCURRED LAST NIGHT/EARLY THIS MORNING IS OVER THE SOUTHERN HALF OF THE AREA. THEREFORE A FLASH FLOOD WATCH HAS BEEN ISSUED THROUGH TONIGHT. VERY LIGHT LINGERING RAINFALL MAY BE AROUND THROUGH MID MORNING. AFTER THAT IT SHOULD STAY QUIET UNTIL MID AFTERNOON. WEST TO NORTHWEST FLOW ALOFT WITH ANOTHER SHORTWAVE TROUGH TO MOVE THROUGH. AIR MASS DOES NOT APPEAR AS MOIST. ALSO SURFACE BOUNDARY LOOKS TO BE SOUTH OF AREA. MODELS ARE NOT VERY EXCITED ABOUT THE AFTERNOON RAINFALL CHANCES. HOWEVER CONSIDERING THE RESIDUAL MOISTURE IN PLACE AND A SHORTWAVE TROUGH IN A WEST TO NORTHWEST FLOW ALOFT...AM KEEPING SLIGHT TO CHANCE POPS FOR NOW. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 254 PM MDT SUN JUL 19 2015 FOR THE EXTENDED FORECAST PERIOD...NEEDED TO MAKE SOME CHANGES FOR THIS RUN AS MODELS HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO TWO FEATURES. FIRST...GUIDANCE IS HONING IN ON A MORE SOUTHERN SOLUTION WITH REGARDS TO PRECIPITATION CHANCES MONDAY NIGHT THROUGH TUESDAY NIGHT. THIS IS LIKELY DUE TO A FURTHER SOUTH PUSH FROM THE FRONT THAN ORIGINALLY ANTICIPATED. SECOND...GUIDANCE IS IN BETTER AGREEMENT ON THE LOCATION AND STRENGTH OF THE 500 MB HIGH PRESSURE RIDGE THAT DEVELOPS TOWARDS THE END OF THE WEEK. BEGINNING WITH MONDAY NIGHT...ANTICIPATE RELATIVELY QUIET WEATHER DUE TO THE FRONT AND THUS CONVECTIVE ACTIVITY REMAINING FURTHER SOUTH. SOME MODELS CONTINUE INDICATING ISENTROPIC LIFT DEVELOPING AS A LOW LEVEL JET STRENGTHENS OVER THE FRONT. A NARROW TONGUE OF INSTABILITY RETURNS WITHIN THE SOUTHEASTER FLOW EARLY TUESDAY MORNING SO SOME ELEVATED SHOWERS/STORMS MAY BE ABLE TO DEVELOP. ALL PARAMETERS ARE DELAYED BY 6-12 HOURS FROM YESTERDAY SO ACTIVITY MAY HOLD OFF UNTIL AFTER SUNRISE TUESDAY. THEREFORE...LOWERED POPS FOR MONDAY NIGHT. FOR TUESDAY THROUGH WEDNESDAY...ANOTHER WET PERIOD IS ANTICIPATED. UNCERTAINTY REMAINS ON THE EXACT AXIS WHERE THE RAIN WILL OCCUR. IN ADDITION...THERE MAY BE A TIGHT GRADIENT BETWEEN LITTLE TO NO RAINFALL AND ANOTHER ROUND OF BENEFICIAL SOAKING RAINS. THE BEST FORCING SHOULD ARRIVE DURING THE DAY TUESDAY...SLOWLY TRANSITIONING INTO CENTRAL KANSAS BY WEDNEDAY MORNING. THEREFORE...THE BEST CHANCES FOR WIDESPREAD PRECIPITATION SHOULD OCCUR TUESDAY NIGHT WITH CHANCES DIMINISHING WEDNESDAY. PRECIPITABLE WATER VALUES INCREASE TUESDAY AND TUESDAY NIGHT...REACHING A MAXIMUM NEAR 1.60 INCHES BY WEDNESDAY MORNING. THEREFORE...RAIN COULD BE HEAVY AT TIMES WITH SOME THUNDERSTORMS. BY LATE WEDNESDAY INTO THURSDAY...THE RIDGE OF HIGH PRESSURE OVER THE SOUTHERN UNITED STATES SLIDES WEST AND STRENGTHENS/BUILDS NORTH OVER THE HIGH PLAINS. THIS SHOULD LEAD TO AN END IN PRECIPITATION CHANCES FOR THE MOST PART AS WELL AS A RETURN TO HOT TEMPERATURES. FOR THURSDAY THROUGH AT LEAST NEXT WEEKEND...SOME MEMBERS OF THE FORECAST GUIDANCE DO INDICATE CHANCES FOR ISOLATED THUNDERSTORMS. HOWEVER...THERE IS NOT A CONSISTENT SIGNAL AMONGST THE GUIDANCE AND NO TIME PERIODS IN PARTICULAR TO HONE IN ON. IN FACT...THINK THAT MOST LIKELY THE REGION REMAINS DRY DUE TO CLOSENESS/STRENGTH OF THE HIGH PRESSURE RIDGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1137 PM MDT SUN JUL 19 2015 VFR CONDITIONS ARE EXPECTED OVERNIGHT AND MONDAY BEHIND THE CURRENT EXITING SHORTWAVE. RADAR SHOWING THE BACK EDGE OF STORMS MOVING WELL TO THE EAST OF THE AREA. THERE IS A SLIGHT CHANCE OF ANOTHER ROUND OF STORMS MONDAY AFTERNOON AND EVENING BUT THE FRONT SHOULD BE SOUTH OF THE TERMINALS WITH LITTLE CHANCE OF ANY STORM IMPACTING THEM. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...FS SHORT TERM...BULLER LONG TERM...RRH AVIATION...FS
...UPDATE TO AVIATION FORECAST DISCUSSION...

.SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 309 PM CDT SUN JUL 19 2015 THE UPPER LEVEL TROUGH AND MCV THAT HELPED PROVIDE ASCENT FOR THE COMPLEX OF THUNDERSTORMS THAT MOVED ACROSS THE NORTHERN HALF OF THE CWA THIS MORNING HAS NOW MOVED EAST ACROSS NORTHERN MO INTO IL. THE NORTHERN COUNTIES OF THE CWA ALONG THE NE BORDER PICKED UP BETWEEN 2 TO 5 INCHES OF RAINFALL WHICH RESULTED IN SOME FLASH FLOODING BETWEEN 6 AM-8AM. A SURFACE OUTFLOW BOUNDARY HAS MOVED SOUTH ACROSS MUCH OF THE CWA...THOUGH THE SOUTHERN COUNTIES WERE BEGIN TO RECOVER INTO THE LOWER 80S WITH MID 70 DEWPOINTS. THE MESOSCALE MODELS DO NOT SHOW ANY THUNDERSTORMS DEVELOPING ALONG THE OUTFLOW BOUNDARY ACROSS EAST CENTRAL KS. I`LL PROBABLY JUST GO WITH 14 POPS FOR TONIGHT AND THROUGH MUCH OF THE EVENING HOURS. EASTERLY UPSLOPE FLOW COMBINED WITH ASCENT FRONT ANOTHER WEAK UPPER LEVEL TROUGH WILL CAUSE NUMEROUS SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE HIGH PLAINS OF EASTERN CO AND WESTERN KS LATE THIS AFTERNOON AND THROUGH THE EVENING HOURS. I EXPECT AN MCS/COMPLEX OF THUNDERSTORMS TO DEVELOP ACROSS WESTERN KS DURING THE MID EVENING HOURS AND TRACK EAST-NORTHEAST ACROSS EASTERN KS DURING THE LATE EVENING AND MORNING HOURS OF MONDAY. THERE`S STILL SOME UNCERTAINTY TO WHERE THE MCS WILL FORM AND TRACK. THE HRRR HAS BEEN PERFORMING WELL BETWEEN 03Z-12Z THE PAST FEW DAYS AND SHOWS THE COMPLEX OF STORMS DEVELOPING ACROSS WEST CENTRAL AND SOUTHWEST KS AND MOVING NORTHEAST ACROSS THE NORTHERN COUNTIES OF THE CWA. THE WRF SOLUTIONS ARE A BIT FARTHER SOUTH ALONG THE I-70 CORRIDOR. THE 12Z NAM SHOWS THE COMPLEX OF STORMS WEAKENING THROUGH THE EARLY MORNING HOURS ONCE IT REACHES CENTRAL AND NORTH CENTRAL KS. DUE TO THE HEAVY RAINFALL THIS MORNING ACROSS THE NORTHERN COUNTIES OF THE CWA...AND THE CHANCE OF AN MCS OR COMPLEX OF STORMS MOVING ACROSS THE SAME AREA DURING THE EARLY MORNING HOURS OF MONDAY...I HAVE DECIDED TO ISSUE A FLASH FLOOD WATCH IN EFFECT FROM 9 PM THROUGH 11 AM MONDAY. THE FLASH FLOOD WATCH IS GENERALLY ALONG A MINNEAPOLIS TO MANHATTAN...TO HOYT...TO OKALOOSA LINE. COUNTIES FARTHER SOUTH MAY HAVE TO BE ADDED ON THIS EVENING IF THE MCS DEVELOPS FARTHER SOUTH AND MOVES ACROSS THE CENTRAL OR SOUTHERN COUNTIES OF THE CWA. THE ENVIRONMENT LATE TONIGHT AND THROUGH THE MORNING HOURS ACROSS NORTHEAST KS WILL CONSIST OF 2000-3000 MUCAPE ALONG WITH 0-6KM EFFECTIVE SHEAR OF 25 TO 35 KTS. THEREFORE SOME OF THE STRONGER UPDRAFTS IN A COMPLEX OF STORMS MAY BE SEVERE WITH THE PRIMARY HAZARD BEING DAMAGING WIND GUSTS AND HAIL UP TO HALF DOLLAR SIZE. IF A FORWARD PROPAGATING MCS DEVELOPS THEN THERE MAY BE MORE WIDESPREAD DAMAGING WIND GUSTS. ANY MCS OR COMPLEX OF THUNDERSTORMS WILL PRODUCE HEAVY RAINFALL WITH FORECAST PWATS IN THE 1.9-2.25 INCH RANGE. MONDAY...THE COMPLEX OF STORMS WILL BE ONGOING ACROSS PORTIONS OF THE CWA DURING THE MORNING HOURS. THE UPPER LEVEL TROUGH WILL MOVE EAST-SOUTHEAST ACROSS EASTERN NE AND EASTERN KS DURING THE AFTERNOON HOUR. THERE COULD BE A BREAK IN THE THUNDERSTORM CHANCES DURING THE EARLY AFTERNOON HOURS BUT THE EASTERN COUNTIES MAY SEE NEW STORMS DEVELOP ON A STRONGER SURFACE FRONT THAT WILL PUSH SOUTHEAST ACROSS THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL REMAIN COOLER DUE TO THE MORNING RAIN CHANCES AND CLOUD COVER INTO THE EARLY AFTERNOON HOURS. HIGHS WILL RANGE FROM THE MID 80S ALONG THE NE BORDER TO LOWER 80S ACROSS THE SOUTHWEST COUNTIES. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 309 PM CDT SUN JUL 19 2015 MONDAY NIGHT THROUGH WEDNESDAY...PREVIOUSLY MENTIONED FRONT PUSHES DOWN TO NEAR KS/OK BORDER BY MIDNIGHT MONDAY NIGHT. COULD BE A FEW LINGERING STORMS IN THE EAST CENTRAL MONDAY EVENING. AFTER MIDNIGHT...A WEAK SYSTEM MOVING THROUGH THE NEAR ZONAL FLOW COMBINES WITH ISENTROPIC UPLIFT OVER THE THERMAL BOUNDARY TO GIVE ANOTHER CHANCE FOR SHOWERS AND STORMS IN EAST CENTRAL KS AND AREAS SOUTH. ON TUESDAY...SUBSIDENCE BEHIND WEAK WAVE AND INFLUENCE OF SURFACE HIGH PRESSURE RIDGE SHOULD KEEP AREA DRY WITH LOWER DEWPOINTS AND COOLER TEMPERATURES IN THE 80S. ANOTHER WEAK TROUGH IN THE ZONAL FLOW ALOFT AFFECTS THE AREA ON TUESDAY NIGHT AND WEDNESDAY. WHILE SURFACE BOUNDARY IS FORECAST BY THE MODELS TO EDGE NORTHWARD...BEST LIFT SHOULD BE ACROSS THE SOUTHERN HALF OF KS AND HAVE CONFINED HIGHEST POPS AND LARGER QPF TO OUR EAST CENTRAL KS COUNTIES TO THE SOUTH OF I70. THURSDAY THROUGH SUNDAY...LATE WEEK LOOKS TO HAVE SEVERAL ON AND OFF CHANCES OF PRECIP. THURSDAY WILL LIKELY BE THE WETTEST DAY WITH PLENTY OF SUBTROPICAL MOISTURE EXTENDING UP INTO THE REGION AS WELL A COUPLE MID LEVEL IMPULSES WORKING OUT OF THE CENTRAL ROCKIES AND OVER NORTHEASTERN KS. GENERALLY HAVE POPS DECREASING HEADING INTO THURSDAY AFTERNOON TAPERING OFF FAIRLY SHARPLY BY EVENING WITH A HIGHLY AMPLIFIED BUT NARROW UPPER RIDGE BUILDING INTO THE CENTRAL PLAINS EXTENDING INTO THE UPPER MISSISSIPPI VALLEY FOR FRIDAY. BY SATURDAY MORNING A BROADER MID LEVEL RIDGE SITUATES ITSELF OVER THE SOUTHERN AND CENTRAL ROCKIES WITH A NORTHWEST FLOW REGIME IN PLACE OVER THE OUTLOOK AREA. THIS WILL LIKELY PROVIDE SOME SMALL CHANCES FOR SCATTERED PRECIP ON SATURDAY MORNING MAINLY OVER AREAS NEAR THE KS/NE BORDER. THE LONG TERM MODELS DIFFER A BIT AT THIS POINT AS THE ECMWF SUGGESTS THAT AN MCS WILL HAVE DEVELOPED OVERNIGHT FRIDAY AND MOVE INTO THE REGION BY SATURDAY MORNING, WHILE THE GFS AND CANADIAN SUGGEST THAT A WEAK BOUNDARY WILL BE FORCED INTO THE AREA ASSOCIATED WITH THE BROADER TROUGH OF THE WESTERLIES MOVING INTO THE UPPER MISSISSIPPI VALLEY. EITHER WAY, IT DOES APPEAR THERE WILL BE AT LEAST SOME SUPPORT FOR SHOWERS AND MORNING THUNDERSTORMS SATURDAY. WITH A SITUATION THAT LOOKS TO LEAVE SEVERAL POTENTIAL BOUNDARIES IN PLAY OVER THE REGION, SUNDAY COULD SEE ANOTHER CHANCE FOR PRECIP AS A WEAK WAVE TURNS THE RIDGE AND INSTABILITY SETS UP WITH DAYTIME HEATING. HIGHS DURING THE PERIOD WILL LIKELY BE INTO THE 90S FOR FRIDAY THROUGH SUNDAY WITH WARMEST TEMPERATURES IN PARTS OF CENTRAL KS. LOWS LIKELY REMAIN IN THE 70S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1220 AM CDT MON JUL 20 2015 CONVECTION REMAINS THE CHALLENGE WITH THE TAF CYCLE. HIT AND MISS TSRA WILL BODE FOR VCTS EARLY IN THE FORECAST AND BECOME A TEMPO IN A FEW HOURS AS HIGHER COVERAGE COMPLEX MOVES EASTWARD AND CAN REASSESS. DOES STILL LOOK TO CLEAR MID TO LATE MORNING WITH NORTHERLY WINDS TAKING HOLD BEHIND. && .TOP WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR KSZ008>012-020>024- 026-034. && $$ SHORT TERM...GARGAN LONG TERM...PHILLIPS/DRAKE AVIATION...67
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
322 PM EDT Mon Jul 20 2015 .SHORT TERM (Now through Tuesday Night)... Issued at 315 PM EDT Mon Jul 20 2015 Plenty of debris cloudiness overhead as a result of convection that affected western Kentucky early this morning. Within the last hour we have seen storms develop where the old outflow boundary is interacting with the Cumberland Escarpment, but these storms are already pushing onto the Plateau as we speak. Main challenge is timing and impact of the round, or rounds of storms that could affect mainly central Kentucky through tonight. Even the hi-res models seem to really be struggling from one run to the next, so this is quite a low-confidence forecast. A couple of weak swirls were apparent in visible imagery over southern Illinois and western Kentucky, but even this juicy environment is not responding yet. Earlier HRRR runs have seemed to be the only models with any handle on initial conditions, and have hinted that one round of convection could come through in the hours just before sunset, with others keying on the actual front which would arrive around midnight. Less confident in the SPC slight risk as progged DCAPE is well out of sync with current analysis, and the effective source of lift remains unclear. Best chance is from roughly 22Z to 05Z Tue, but not likely to affect that entire time period. Even with the low-confidence forecast, any storms that do develop could be prolific rain producers due to high precipitable water and storm motion parallel to a nearly stationary boundary. Flash Flood Guidance is quite low especially across the Bluegrass, where 1-hr FFG is 1.5 inches or less in many places. Therefore will continue with the Flash Flood Watch until Tuesday morning, but no extension is planned unless convective trends show themselves more clearly. Whatever organized storms we see should clear the area around midnight or not too long after. Wind shift arrives by mid-morning, but we`ll hang on to high dewpoints and chance POPs through the day as fropa seems to occur in pieces. Mid-level WNW winds picking up to around 30 kt could support a few strong storms with gusty winds over east-central KY, but organized SVR potential is farther north and east as our precip chances will be diminishing as the afternoon progresses. Chance POPs in the middle of the day will be dropping off by mid/late afternoon, with only south central KY in a slight chance for storms for Tue night. Drier air will be filtering in, with dewpoints dropping into the lower/mid 60s and temps dropping to the upper 60s/near 70. .LONG TERM (Wednesday through Monday)... Issued at 300 PM EDT Mon Jul 20 2015 The synoptic pattern at the start of the long term period will feature generally northwest flow across the Ohio Valley, as ridging over the south-central CONUS remains in place. This ridging will actually build NNE into the region by this weekend, bringing a return to the hot and humid conditions. A weak frontal boundary will have pushed into TN at the start of the long term period. There is some discrepancy in the guidance as to how far south this boundary will get, which will be the deciding factor as to whether or not southern KY ends up dry. For now, will continue with slight chance pops across southern KY Wednesday into Thursday as impulses riding along this boundary may be enough to bring precip into the region, but suspect most will end up dry. Given the majority of the region will be on the northern side of the front, temperatures and humidity values will be rather comfortable. Look for highs in the low to mid 80s with dewpoints in the low to mid 60s, perhaps pushing into the upper 60s over southern KY. Heading into Friday and through the upcoming weekend, upper-level ridging will build back into the Ohio Valley which will bring increasing heat and humidity. The region will still be on the periphery of the mid-level westerlies/northwesterlies, so cannot completely rule out thunderstorm chances this weekend. It appears the best chance for a disturbance to impact the region may come Saturday night into Sunday, but confidence in that scenario is quite low and does not warrant any higher mention than just slight chance to chance POPs (20-30%). Otherwise, it will be hot and humid as upper-level ridging builds in and 850mb temps rise back to near 20C. Look for highs back in the upper 80s and lower 90s with heat indices from 95-100 degrees at times. && .AVIATION (18Z TAF Update)... Updated 1250 PM EDT Mon Jul 20 2015 Decent cu field already developing anywhere that the mid/high cloud deck has thinned. Bases are only between 3-4K feet as temp/dewpoint spreads are not that big. Expect enough continued cu development for ceilings this afternoon, but should remain VFR. Otherwise we`ll remain convectively quiet until very late in the afternoon, at which point a weakening precip shield now moving across southern Illinois will arrive. Best chance for storms will be this evening, either with the leading upper impulse or if convection develops along the actual front, which would swing in closer to midnight. Still enough uncertainty in the timing to limit the mention to VCTS/CB over a period longer than we expect actual impacts. Will stay VFR, but brief IFR will likely accompany any thunderstorm that directly impacts an airport. SW winds will come around to NW around daybreak for SDF, but more like mid to late morning in BWG and LEX. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...FLASH FLOOD WATCH through Tuesday morning FOR KYZ029>043-045>049- 054>057-065>067-077-078-081-082. IN...FLASH FLOOD WATCH through Tuesday morning FOR INZ078-079-091-092. && $$ Short Term........RAS Long Term.........KJD Aviation..........RAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
200 PM EDT MON JUL 20 2015 .UPDATE... ISSUED AT 1057 AM EDT MON JUL 20 2015 ISOLATED RAIN SHOWERS CONTINUE ACROSS THE CWA. WHILE LATEST HI RES MODELS HAVE NOT BEEN PERFORMING VERY WELL FOR THE LAST FEW DAYS...THE HRRR IS ACTUALLY INITIATING QUITE WELL OVER THE LAST COUPLE HOURS. BASED ON THE LATEST RADAR TRENDS...AS WELL AS THE LATEST HRRR...DON/T EXPECT THINGS TO REALLY START TICKING UP TO SCATTERED TO NUMEROUS UNTIL LATE IN THE AFTERNOON. AS SUCH...WENT AHEAD AND CUT BACK POPS DURING THE REST OF THE MORNING TO SLOW DOWN THE INCREASE IN COVERAGE. ALSO...LOADED IN THE LATEST OBSERVATIONAL DATA INTO THE NEAR TERM GRIDS FOR TEMPS...DEW POINTS...AND WINDS...TO MAKE SURE OUR FORECAST MATCHED UP WITH THE ONGOING CONDITIONS. UPDATE ISSUED AT 649 AM EDT MON JUL 20 2015 THE FORECAST IS IN GOOD SHAPE SO FAR THIS MORNING. ISOLATED RAIN SHOWERS ARE ALREADY MOVING INTO THE AREA FROM THE WEST. THIS TREND IS EXPECTED TO CONTINUE THROUGHOUT THE MORNING...WITH THUNDERSTORMS GETTING INTO THE MIX BY 15 OR 16Z. ASIDE FROM INGESTING THE LATEST OBS DATA INTO THE FORECAST GRIDS...NO CHANGES TO THE FORECAST WERE NECESSARY. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 301 AM EDT MON JUL 20 2015 SCATTERED SHOWERS AND THUNDERSTORMS ARE BRINGING LOCALLY HEAVY RAINFALL TO PORTIONS OF EASTERN KENTUCKY THIS OVERNIGHT. PIKE...ROCKCASTLE...AND LAUREL COUNTIES IN PARTICULAR WERE EXPERIENCING HEAVY RAIN AT AFD ISSUANCE. ISOLATED TO SCATTERED SHOWERS AND STORMS WILL LIKELY CONTINUE THROUGH THE NIGHT...WITH A GRADUAL WEAKENING TREND EXPECTED THROUGH SUN RISE. SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE EXPECTED TO FIRE UP AGAIN THIS AFTERNOON...AS A COLD FRONT APPROACHES FROM THE NORTH. SOME OF THE STORMS THIS AFTERNOON COULD BE STRONG...WITH GUSTY WINDS...LOCALLY HEAVY RAINFALL AND SMALL HAIL ALL POSSIBLE. SCATTERED STORMS ARE EXPECTED TO CONTINUE AGAIN THROUGH TUESDAY MORNING. THE SHOWERS AND STORMS WILL THEN BECOME NUMEROUS AGAIN TUESDAY AFTERNOON AND EVENING...AS THE COLD FRONT PUSHES SLOWLY ACROSS THE AREA. THE MODELS IN GENERAL DO NOT HAVE A GOOD HANDLE ON THE CURRENT WEATHER...SO A MODIFIED BLEND OF MODEL DATA WAS USED TO CREATE THE FORECAST. TEMPERATURES THROUGH TOMORROW ARE EXPECTED TO RUN AT OR SLIGHTLY ABOVE NORMAL TODAY...RIGHT AT NORMAL TOMORROW...AND SEVERAL DEGREES ABOVE NORMAL TONIGHT. TODAYS HIGHS ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 80S FOR MOST LOCATIONS...WITH A FEW STRAY READINGS AT OR JUST ABOVE 90 NOT OUT OF THE QUESTION ALONG THE TENNESSEE BORDER. TONIGHTS LOWS WILL ONCE AGAIN BE QUITE BALMY...WITH MIN READINGS IN THE LOWER 70S ON TAP. HIGHS ON TUESDAY SHOULD COME IN RIGHT ABOUT NORMAL...WITH MAX READINGS IN THE MID 80S EXPECTED. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 301 AM EDT MON JUL 20 2015 WHILE THE LONG TERM PORTION OF THE FORECAST CERTAINLY LOOKS QUIETER AND LESS ACTIVE...STILL LOTS OF UNCERTAINTY IN THE FORECAST...ALL REVOLVING AROUND EXACTLY HOW FAR SOUTH THE FRONTAL BOUNDARY MAKES IT ON TUESDAY. GFS PUSHES THIS BOUNDARY OFF TO THE SOUTH...WITH DRY WEATHER ARRIVING FOR THE MIDDLE OF THE WEEK...WHILE THE ECMWF HANGS UP THE BOUNDARY FARTHER NORTH...KEEPING AT LEAST THE SOUTHERN HALF OF KENTUCKY WITH A THREAT OF SHOWERS/STORMS THROUGH THE REMAINDER OF THE WEEK. GIVEN THE ABUNDANCE OF WET WEATHER LATELY AND THE TENDENCY FOR FRONTS TO NOT MAKE A GOOD PUSH SOUTH THIS TIME OF YEAR...HAVE OPTED TO KEEP SOME POPS ACROSS SOUTHERN KENTUCKY THROUGH MOST OF THE WEEK. PLAN TO KEEP THINGS IN THE 20 TO 30 RANGE FOR POPS GIVEN THE UNCERTAINTY. NORTHERN KENTUCKY...HAS A BETTER SHOT OF HAVING A LONGER PERIOD OF DRY WEATHER THROUGH THE SECOND HALF OF THE WEEK. MODELS ARE ALL OVER THE PLACE AS WE HEAD INTO NEXT WEEKEND WITH THE GFS BRINGING OUR NEXT SYSTEM INTO THE AREA...WHILE THE ECMWF REMAINS DRY. THUS...WILL JUST STAY WITH A COMPROMISED APPROACH AND GO WITH SOME LOW POPS FOR SATURDAY INTO SUNDAY. DESPITE THE MODEL DISAGREEMENTS...IT DOES LOOK LIKE SOME REASONABLE AGREEMENT ON TEMPERATURES AS NO MATTER THE SOLUTION...WE SHOULD SEE COOLER TEMPERATURES FOR THE MIDDLE OF THE WEEK AS THE FRONTAL BOUNDARY SHOULD SET UP SOUTH OF THE AREA...OR EVEN IF IT DOESN`T...WE WILL SEE MORE CLOUD COVER WHICH WILL ALSO KEEP TEMPERATURES LOWER. TEMPERATURES WILL BEGIN TO WARM AGAIN HEADING INTO NEXT WEEKEND AS THE TROUGH OVER THE EAST BREAKS DOWN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 157 PM EDT MON JUL 20 2015 SHOWERS AND THUNDERSTORMS ARE FINALLY STARTING TO POP UP ACROSS SOUTHEAST KY...AND WILL CONTINUE TO INTENSIFY OVER THE NEXT COUPLE OF HOURS...BECOMING MORE SCATTERED IN NATURE. SKY CONDITIONS ACROSS THE REGION WILL BE A MIX OF SCT AND BKN UPPER END MVFR CONDITIONS THROUGH THE AFTERNOON AND EVENING. IN ADDITION TO THE ALREADY HIGH MOISTURE RATES...ANY SHOWERS WHICH DO AFFECT TAF SITES WILL LIKELY LEAD TO FOG DEVELOP OVERNIGHT. THE EXACT IMPACTS FROM THIS FOG ARE STILL SOMEWHAT UNCERTAIN...SO WHILE ONLY IFR CONDITIONS ARE FORECAST...SOME MOMENTS OF EVEN LOWER CONDITIONS ARE POSSIBLE...ESPECIALLY NEAR DAWN AS SOME OF THE VALLEY FOG LIFTS. SHOWERS AND THUNDERSTORMS WILL ALSO BE ONGOING ACROSS PORTIONS OF THE CWA DURING THE NIGHT...AND WILL CONTINUE ON INTO THE DAY TUESDAY. VIS WILL LIKELY BE REDUCED TO SOME VARYING DEGREE AT THE TAF SITE UNDER ANY STORM WHICH AFFECTS THEM. OVERALL...WINDS WILL REMAIN LIGHT...GENERALLY LESS THAN 5 KNOTS. HOWEVER...SOME OF THE LARGER STORMS MAY PRODUCE MUCH STRONGER WIND GUSTS. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JMW SHORT TERM...AR LONG TERM...KAS AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 AM EDT MON JUL 20 2015 .UPDATE... ISSUED AT 1057 AM EDT MON JUL 20 2015 ISOLATED RAIN SHOWERS CONTINUE ACROSS THE CWA. WHILE LATEST HI RES MODELS HAVE NOT BEEN PERFORMING VERY WELL FOR THE LAST FEW DAYS...THE HRRR IS ACTUALLY INITIATING QUITE WELL OVER THE LAST COUPLE HOURS. BASED ON THE LATEST RADAR TRENDS...AS WELL AS THE LATEST HRRR...DON/T EXPECT THINGS TO REALLY START TICKING UP TO SCATTERED TO NUMEROUS UNTIL LATE IN THE AFTERNOON. AS SUCH...WENT AHEAD AND CUT BACK POPS DURING THE REST OF THE MORNING TO SLOW DOWN THE INCREASE IN COVERAGE. ALSO...LOADED IN THE LATEST OBSERVATIONAL DATA INTO THE NEAR TERM GRIDS FOR TEMPS...DEW POINTS...AND WINDS...TO MAKE SURE OUR FORECAST MATCHED UP WITH THE ONGOING CONDITIONS. UPDATE ISSUED AT 649 AM EDT MON JUL 20 2015 THE FORECAST IS IN GOOD SHAPE SO FAR THIS MORNING. ISOLATED RAIN SHOWERS ARE ALREADY MOVING INTO THE AREA FROM THE WEST. THIS TREND IS EXPECTED TO CONTINUE THROUGHOUT THE MORNING...WITH THUNDERSTORMS GETTING INTO THE MIX BY 15 OR 16Z. ASIDE FROM INGESTING THE LATEST OBS DATA INTO THE FORECAST GRIDS...NO CHANGES TO THE FORECAST WERE NECESSARY. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 301 AM EDT MON JUL 20 2015 SCATTERED SHOWERS AND THUNDERSTORMS ARE BRINGING LOCALLY HEAVY RAINFALL TO PORTIONS OF EASTERN KENTUCKY THIS OVERNIGHT. PIKE...ROCKCASTLE...AND LAUREL COUNTIES IN PARTICULAR WERE EXPERIENCING HEAVY RAIN AT AFD ISSUANCE. ISOLATED TO SCATTERED SHOWERS AND STORMS WILL LIKELY CONTINUE THROUGH THE NIGHT...WITH A GRADUAL WEAKENING TREND EXPECTED THROUGH SUN RISE. SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE EXPECTED TO FIRE UP AGAIN THIS AFTERNOON...AS A COLD FRONT APPROACHES FROM THE NORTH. SOME OF THE STORMS THIS AFTERNOON COULD BE STRONG...WITH GUSTY WINDS...LOCALLY HEAVY RAINFALL AND SMALL HAIL ALL POSSIBLE. SCATTERED STORMS ARE EXPECTED TO CONTINUE AGAIN THROUGH TUESDAY MORNING. THE SHOWERS AND STORMS WILL THEN BECOME NUMEROUS AGAIN TUESDAY AFTERNOON AND EVENING...AS THE COLD FRONT PUSHES SLOWLY ACROSS THE AREA. THE MODELS IN GENERAL DO NOT HAVE A GOOD HANDLE ON THE CURRENT WEATHER...SO A MODIFIED BLEND OF MODEL DATA WAS USED TO CREATE THE FORECAST. TEMPERATURES THROUGH TOMORROW ARE EXPECTED TO RUN AT OR SLIGHTLY ABOVE NORMAL TODAY...RIGHT AT NORMAL TOMORROW...AND SEVERAL DEGREES ABOVE NORMAL TONIGHT. TODAYS HIGHS ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 80S FOR MOST LOCATIONS...WITH A FEW STRAY READINGS AT OR JUST ABOVE 90 NOT OUT OF THE QUESTION ALONG THE TENNESSEE BORDER. TONIGHTS LOWS WILL ONCE AGAIN BE QUITE BALMY...WITH MIN READINGS IN THE LOWER 70S ON TAP. HIGHS ON TUESDAY SHOULD COME IN RIGHT ABOUT NORMAL...WITH MAX READINGS IN THE MID 80S EXPECTED. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 301 AM EDT MON JUL 20 2015 WHILE THE LONG TERM PORTION OF THE FORECAST CERTAINLY LOOKS QUIETER AND LESS ACTIVE...STILL LOTS OF UNCERTAINTY IN THE FORECAST...ALL REVOLVING AROUND EXACTLY HOW FAR SOUTH THE FRONTAL BOUNDARY MAKES IT ON TUESDAY. GFS PUSHES THIS BOUNDARY OFF TO THE SOUTH...WITH DRY WEATHER ARRIVING FOR THE MIDDLE OF THE WEEK...WHILE THE ECMWF HANGS UP THE BOUNDARY FARTHER NORTH...KEEPING AT LEAST THE SOUTHERN HALF OF KENTUCKY WITH A THREAT OF SHOWERS/STORMS THROUGH THE REMAINDER OF THE WEEK. GIVEN THE ABUNDANCE OF WET WEATHER LATELY AND THE TENDENCY FOR FRONTS TO NOT MAKE A GOOD PUSH SOUTH THIS TIME OF YEAR...HAVE OPTED TO KEEP SOME POPS ACROSS SOUTHERN KENTUCKY THROUGH MOST OF THE WEEK. PLAN TO KEEP THINGS IN THE 20 TO 30 RANGE FOR POPS GIVEN THE UNCERTAINTY. NORTHERN KENTUCKY...HAS A BETTER SHOT OF HAVING A LONGER PERIOD OF DRY WEATHER THROUGH THE SECOND HALF OF THE WEEK. MODELS ARE ALL OVER THE PLACE AS WE HEAD INTO NEXT WEEKEND WITH THE GFS BRINGING OUR NEXT SYSTEM INTO THE AREA...WHILE THE ECMWF REMAINS DRY. THUS...WILL JUST STAY WITH A COMPROMISED APPROACH AND GO WITH SOME LOW POPS FOR SATURDAY INTO SUNDAY. DESPITE THE MODEL DISAGREEMENTS...IT DOES LOOK LIKE SOME REASONABLE AGREEMENT ON TEMPERATURES AS NO MATTER THE SOLUTION...WE SHOULD SEE COOLER TEMPERATURES FOR THE MIDDLE OF THE WEEK AS THE FRONTAL BOUNDARY SHOULD SET UP SOUTH OF THE AREA...OR EVEN IF IT DOESN`T...WE WILL SEE MORE CLOUD COVER WHICH WILL ALSO KEEP TEMPERATURES LOWER. TEMPERATURES WILL BEGIN TO WARM AGAIN HEADING INTO NEXT WEEKEND AS THE TROUGH OVER THE EAST BREAKS DOWN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 649 AM EDT MON JUL 20 2015 SHOWERS AND THUNDERSTORMS ARE EXPECTED TO AFFECT THE TAF SITES AFTER 18Z TODAY. LOCALLY HEAVY RAINFALL...STRONG WINDS...AND FREQUENT LIGHTNING WILL BE THE PRIMARY THREATS WITH ANY THUNDERSTORMS. CONDITIONS AT THE TAF SITES WILL REMAIN VFR DURING DRY PERIODS...WITH MVFR TO IFR CONDITIONS POSSIBLE DURING INTENSE RAIN SHOWERS OR ANY THUNDERSTORMS. THE SHOWERS AND STORMS WILL PERSIST THROUGH THE END OF THE TAF PERIOD...WITH PEAK ACTIVITY DURING THE AFTERNOON AND EVENING HOURS TODAY AND TOMORROW. && .JKL WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR KYZ044-050>052- 058>060-068-069-079-080-083>088-104-106>120. && $$ UPDATE...JMW SHORT TERM...AR LONG TERM...AR AVIATION...AR
AREA FORECAST DISCUSSION
NWS PADUCAH KY
649 AM CDT MON JUL 20 2015 .UPDATE... ISSUED AT 649 AM CDT MON JUL 20 2015 THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 358 AM CDT MON JUL 20 2015 THE DILEMMA TODAY IS HOW TO RECONCILE 2 MCS/S WITH THE POTENTIAL FOR A HEAT ADVISORY OVER MUCH OF THE AREA. ONE MCS IS CURRENTLY RAINING ITSELF OUT OVER OUR REGION...WHILE A SECOND ONE IS MOVING EASTWARD OUT OF NORTHEAST KANSAS AND WESTERN MISSOURI. THERE IS A CORRIDOR OF CONVECTION WITH THE POTENTIAL FOR FLASH FLOODING EXTENDING BETWEEN THE TWO SYSTEMS FROM REYNOLDS COUNTY NORTHWESTWARD. THE LATEST HRRR HAS A GOOD HANDLE ON THE FIRST MCS...SLOWLY DISSIPATING IT AS IT MOVES OVER WEST KENTUCKY THROUGH 14Z. IT DOES NOT HAVE A GOOD HANDLE ON THE CONVECTION FROM REYNOLDS COUNTY WESTWARD. IT TAKES THE BULK OF THE WESTERN MCS EASTWARD...KEEPING IT NORTHWEST OF OUR AREA THROUGH 18Z. UNFORTUNATELY...THERE IS SOME POTENTIAL FOR THE REYNOLDS COUNTY CONVECTION TO PUSH EAST AND IMPACT AREAS ALONG AND NORTH OF A PIEDMONT TO CAPE GIRARDEAU LINE. CONTEMPLATED JOINING SGF AND LSX IN ISSUING A FLASH FLOOD WATCH FOR A PORTION OF SOUTHEAST MISSOURI...BUT RECENT RADAR TRENDS SHOW ENOUGH EASTWARD MOVEMENT OF THE ENTIRE ZONE THAT IT SHOULD NOT BE A MAJOR ISSUE IN OUR AREA. WITH THE RAIN OVER THE AREA SURFACE DEWPOINTS WILL LIKELY HOLD IN THE MID TO UPPER 70S THROUGH THE DAY. IF THE PRECIPITATION AND THE ASSOCIATED CLOUD COVER DISSIPATE...TEMPERATURES COULD QUICKLY CLIMB BACK INTO THE 90S. THE BOTTOM LINE IS THAT HEAT INDICES ARE FORECAST TO REACH NEAR 105 OVER MOST OF SOUTHEAST MISSOURI...THE PURCHASE AND LAKES AREAS OF WEST KENTUCKY...AND ADJACENT PORTIONS OF SOUTHERN ILLINOIS. CONTEMPLATED ISSUING A HEAT ADVISORY GIVEN THIS FORECAST...BUT THERE ARE A LOT OF MOVING PARTS THAT HAVE TO COME TOGETHER TO MAKE IT HAPPEN. CONFIDENCE IS JUST NOT HIGH ENOUGH. IF I WOULD HAVE ISSUED AN ADVISORY WITH THIS PACKAGE IT WOULD HAVE ONLY BEEN FOR BUTLER...RIPLEY AND CARTER COUNTIES...WHERE THEY ARE MOST LIKELY TO SEE A GOOD BIT OF SUNSHINE TODAY. WILL LET THE DAY SHIFT MONITOR RADAR AND SATELLITE TRENDS AND ISSUE AN ADVISORY WHEN CONFIDENCE INCREASES ENOUGH. CONFIDENCE IN CONVECTIVE TRENDS BEYOND THIS MORNING IS QUITE LOW. THE GENERAL TRENDS ARE FOR BETTER CHANCE POPS OVER THE WESTERN HALF OF SOUTHERN ILLINOIS THIS AFTERNOON AS THE KS/MO MCS GLANCES BY THE REGION. TONIGHT A COLD FRONT IS STILL SUPPOSED TO REACH THE AREA...SO WILL HAVE LIKELY POPS OVER MUCH OF THE REGION. THE CONSENSUS OF 00Z GUIDANCE HAS THE FRONT OUT OF THE AREA BY EARLY TUESDAY...SO WOULD NOT BE TERRIBLY SURPRISED IF MUCH IF NOT ALL OF THE AREA IS DRY TUESDAY THROUGH WEDNESDAY. THE NAM AND GFS GENERATE SCATTERED CONVECTION ALONG WHAT LOOKS LIKE THE 925MB OR 850MB FRONT OVER THE SOUTHERN OR SOUTHEASTERN HALF OF THE AREA TUESDAY. THIS SIGNAL WAS THERE 24 HOURS AGO...SO WILL KEEP 30-40 PERCENT POPS FOR MUCH OF THE AREA. PROBABLY HAVE TOO MUCH POP LEFT OVER TUESDAY NIGHT AND WEDNESDAY. IF THERE IS TO BE CONVECTION IN THE AREA IN THESE PERIODS IT WOULD MOST LIKELY BE IN OUR WESTERN SOUTHEAST MISSOURI COUNTIES. WITH NORTHERLY WINDS EXPECTED TUESDAY THROUGH WEDNESDAY...A COOLING TREND IS FORECAST. HIGHS WILL RANGE FROM THE LOWER 80S NORTH TO THE MID 80S SOUTH ON WEDNESDAY. ENJOY! .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 358 AM CDT MON JUL 20 2015 THE LONG TERM PORTION OF THE FORECAST CENTERS AROUND THE BEHAVIOR OF AN UPPER LEVEL RIDGE OVER THE PLAINS. THE MODELS HAVE SHOWN VARIATIONS REGARDING HOW QUICKLY /AND TO WHAT EXTENT/ THE RIDGE EXPANDS EAST OVER THE MISSISSIPPI VALLEY. THE 00Z MODEL SUITE DOES NOT SHOW ANY MORE MODEL AGREEMENT THAN EARLIER RUNS. TAKING A BLEND OF ALL THE MODELS...THERE WILL BE A GRADUAL RETURN TO HOTTER AND MORE HUMID WEATHER ALONG WITH SMALL DAILY PRECIP CHANCES. AS FAR AS THE DAILY DETAILS... WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...IT APPEARS A FRONTAL BOUNDARY WILL BECOME STATIONARY OVER OUR REGION. THE NORTHWEST TO SOUTHEAST ORIENTED BOUNDARY SHOULD BE THE FOCUS FOR SCATTERED SHOWERS AND STORMS. HIGH PRESSURE OVER THE UPPER OHIO VALLEY WILL FUNNEL RELATIVELY DRY AIR INTO SOUTHWEST INDIANA AND ADJACENT AREAS. THEREFORE...POPS WILL BE NO HIGHER THAN SLIGHT CHANCE THERE. SOUTHWEST OF THE BOUNDARY...RICHER BOUNDARY LAYER MOISTURE WILL SUPPORT POPS OCCASIONALLY IN THE LIKELY CATEGORY IN PARTS OF SOUTHEAST MISSOURI. EXTENSIVE CLOUDS AND PRECIP WILL LIMIT HIGHS TO THE LOWER AND MID 80S...EVEN SOUTH OF THE BOUNDARY. ON FRIDAY AND FRIDAY NIGHT...RISING 500 MB HEIGHTS ASSOCIATED WITH THE PLAINS RIDGE WILL TRANSLATE INTO A GRADUAL WARMING AND DRYING TREND. THE RIDGE WILL NOT BUILD EAST SUFFICIENTLY TO QUASH ALL CHANCES OF CONVECTION. THERE WILL STILL BE A SMALL CHANCE OF PRECIP DUE TO THE POTENTIAL FOR IMPULSES IN THE WEAK NORTHWEST FLOW ALOFT. HIGHS WILL GENERALLY BE AROUND 90 ON FRIDAY...EXCEPT FOR MID TO UPPER 80S NEAR AND NORTH OF INTERSTATE 64. SATURDAY THROUGH SUNDAY...THE FLOW PATTERN WILL BECOME VERY WEAK AT LOWER AND MID LEVELS. ANY EXPANSION OF THE RIDGE WILL BE VERY SLIGHT. ISOLATED DIURNALLY INDUCED CONVECTION IS POSSIBLE BOTH DAYS...BUT NOT ENOUGH TO WARRANT POPS IN MOST AREAS. ALONG AND WEST OF THE MISSISSIPPI VALLEY...WILL MENTION SLIGHT CHANCE POPS DUE TO THE STRONGER INSTABILITY AND HIGHER DEW POINTS IN THAT AREA. HIGHS SHOULD GENERALLY BE IN THE LOWER 90S WITH LOWS IN THE LOWER 70S. && .AVIATION... ISSUED AT 649 AM CDT MON JUL 20 2015 ONE AREA OF SHOWERS AND STORMS WILL PUSH SOUTHEAST OF ALL TERMINALS IN THE NEXT COUPLE OF HOURS. SOME MVFR RAIN WILL BE POSSIBLE IN THE MEANTIME. WINDS SHOULD RECOVER TO SOUTHWEST BY MIDDAY. THE HRRR INDICATES THAT THE NEXT ROUND OF STORMS WILL ARRIVE AT KCGI AROUND 18Z...AND WILL PROGRESS EASTWARD THROUGH THE AFTERNOON. CURRENT INDICATIONS ARE THAT TS POTENTIAL WILL BE CONFINED TO KCGI AND KPAH...WITH ONLY SHOWERS AT KEVV AND KOWB. CANNOT RULE OUT MORE CONVECTION TONIGHT...BUT CONFIDENCE IS TOO LOW TO ADD IT TO THE FORECASTS AT THIS TIME. A COLD FRONTAL WIND SHIFT MAY REACH KCGI AND KEVV BY THE END OF THE PERIOD. WENT ON THE OPTIMISTIC SIDE WITH CEILINGS AND VISIBILITIES THROUGHOUT. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...DRS SHORT TERM...DRS LONG TERM...MY AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
358 AM CDT MON JUL 20 2015 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 358 AM CDT MON JUL 20 2015 THE DILEMMA TODAY IS HOW TO RECONCILE 2 MCS/S WITH THE POTENTIAL FOR A HEAT ADVISORY OVER MUCH OF THE AREA. ONE MCS IS CURRENTLY RAINING ITSELF OUT OVER OUR REGION...WHILE A SECOND ONE IS MOVING EASTWARD OUT OF NORTHEAST KANSAS AND WESTERN MISSOURI. THERE IS A CORRIDOR OF CONVECTION WITH THE POTENTIAL FOR FLASH FLOODING EXTENDING BETWEEN THE TWO SYSTEMS FROM REYNOLDS COUNTY NORTHWESTWARD. THE LATEST HRRR HAS A GOOD HANDLE ON THE FIRST MCS...SLOWLY DISSIPATING IT AS IT MOVES OVER WEST KENTUCKY THROUGH 14Z. IT DOES NOT HAVE A GOOD HANDLE ON THE CONVECTION FROM REYNOLDS COUNTY WESTWARD. IT TAKES THE BULK OF THE WESTERN MCS EASTWARD...KEEPING IT NORTHWEST OF OUR AREA THROUGH 18Z. UNFORTUNATELY...THERE IS SOME POTENTIAL FOR THE REYNOLDS COUNTY CONVECTION TO PUSH EAST AND IMPACT AREAS ALONG AND NORTH OF A PIEDMONT TO CAPE GIRARDEAU LINE. CONTEMPLATED JOINING SGF AND LSX IN ISSUING A FLASH FLOOD WATCH FOR A PORTION OF SOUTHEAST MISSOURI...BUT RECENT RADAR TRENDS SHOW ENOUGH EASTWARD MOVEMENT OF THE ENTIRE ZONE THAT IT SHOULD NOT BE A MAJOR ISSUE IN OUR AREA. WITH THE RAIN OVER THE AREA SURFACE DEWPOINTS WILL LIKELY HOLD IN THE MID TO UPPER 70S THROUGH THE DAY. IF THE PRECIPITATION AND THE ASSOCIATED CLOUD COVER DISSIPATE...TEMPERATURES COULD QUICKLY CLIMB BACK INTO THE 90S. THE BOTTOM LINE IS THAT HEAT INDICES ARE FORECAST TO REACH NEAR 105 OVER MOST OF SOUTHEAST MISSOURI...THE PURCHASE AND LAKES AREAS OF WEST KENTUCKY...AND ADJACENT PORTIONS OF SOUTHERN ILLINOIS. CONTEMPLATED ISSUING A HEAT ADVISORY GIVEN THIS FORECAST...BUT THERE ARE A LOT OF MOVING PARTS THAT HAVE TO COME TOGETHER TO MAKE IT HAPPEN. CONFIDENCE IS JUST NOT HIGH ENOUGH. IF I WOULD HAVE ISSUED AN ADVISORY WITH THIS PACKAGE IT WOULD HAVE ONLY BEEN FOR BUTLER...RIPLEY AND CARTER COUNTIES...WHERE THEY ARE MOST LIKELY TO SEE A GOOD BIT OF SUNSHINE TODAY. WILL LET THE DAY SHIFT MONITOR RADAR AND SATELLITE TRENDS AND ISSUE AN ADVISORY WHEN CONFIDENCE INCREASES ENOUGH. CONFIDENCE IN CONVECTIVE TRENDS BEYOND THIS MORNING IS QUITE LOW. THE GENERAL TRENDS ARE FOR BETTER CHANCE POPS OVER THE WESTERN HALF OF SOUTHERN ILLINOIS THIS AFTERNOON AS THE KS/MO MCS GLANCES BY THE REGION. TONIGHT A COLD FRONT IS STILL SUPPOSED TO REACH THE AREA...SO WILL HAVE LIKELY POPS OVER MUCH OF THE REGION. THE CONSENSUS OF 00Z GUIDANCE HAS THE FRONT OUT OF THE AREA BY EARLY TUESDAY...SO WOULD NOT BE TERRIBLY SURPRISED IF MUCH IF NOT ALL OF THE AREA IS DRY TUESDAY THROUGH WEDNESDAY. THE NAM AND GFS GENERATE SCATTERED CONVECTION ALONG WHAT LOOKS LIKE THE 925MB OR 850MB FRONT OVER THE SOUTHERN OR SOUTHEASTERN HALF OF THE AREA TUESDAY. THIS SIGNAL WAS THERE 24 HOURS AGO...SO WILL KEEP 30-40 PERCENT POPS FOR MUCH OF THE AREA. PROBABLY HAVE TOO MUCH POP LEFT OVER TUESDAY NIGHT AND WEDNESDAY. IF THERE IS TO BE CONVECTION IN THE AREA IN THESE PERIODS IT WOULD MOST LIKELY BE IN OUR WESTERN SOUTHEAST MISSOURI COUNTIES. WITH NORTHERLY WINDS EXPECTED TUESDAY THROUGH WEDNESDAY...A COOLING TREND IS FORECAST. HIGHS WILL RANGE FROM THE LOWER 80S NORTH TO THE MID 80S SOUTH ON WEDNESDAY. ENJOY! .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 358 AM CDT MON JUL 20 2015 THE LONG TERM PORTION OF THE FORECAST CENTERS AROUND THE BEHAVIOR OF AN UPPER LEVEL RIDGE OVER THE PLAINS. THE MODELS HAVE SHOWN VARIATIONS REGARDING HOW QUICKLY /AND TO WHAT EXTENT/ THE RIDGE EXPANDS EAST OVER THE MISSISSIPPI VALLEY. THE 00Z MODEL SUITE DOES NOT SHOW ANY MORE MODEL AGREEMENT THAN EARLIER RUNS. TAKING A BLEND OF ALL THE MODELS...THERE WILL BE A GRADUAL RETURN TO HOTTER AND MORE HUMID WEATHER ALONG WITH SMALL DAILY PRECIP CHANCES. AS FAR AS THE DAILY DETAILS... WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...IT APPEARS A FRONTAL BOUNDARY WILL BECOME STATIONARY OVER OUR REGION. THE NORTHWEST TO SOUTHEAST ORIENTED BOUNDARY SHOULD BE THE FOCUS FOR SCATTERED SHOWERS AND STORMS. HIGH PRESSURE OVER THE UPPER OHIO VALLEY WILL FUNNEL RELATIVELY DRY AIR INTO SOUTHWEST INDIANA AND ADJACENT AREAS. THEREFORE...POPS WILL BE NO HIGHER THAN SLIGHT CHANCE THERE. SOUTHWEST OF THE BOUNDARY...RICHER BOUNDARY LAYER MOISTURE WILL SUPPORT POPS OCCASIONALLY IN THE LIKELY CATEGORY IN PARTS OF SOUTHEAST MISSOURI. EXTENSIVE CLOUDS AND PRECIP WILL LIMIT HIGHS TO THE LOWER AND MID 80S...EVEN SOUTH OF THE BOUNDARY. ON FRIDAY AND FRIDAY NIGHT...RISING 500 MB HEIGHTS ASSOCIATED WITH THE PLAINS RIDGE WILL TRANSLATE INTO A GRADUAL WARMING AND DRYING TREND. THE RIDGE WILL NOT BUILD EAST SUFFICIENTLY TO QUASH ALL CHANCES OF CONVECTION. THERE WILL STILL BE A SMALL CHANCE OF PRECIP DUE TO THE POTENTIAL FOR IMPULSES IN THE WEAK NORTHWEST FLOW ALOFT. HIGHS WILL GENERALLY BE AROUND 90 ON FRIDAY...EXCEPT FOR MID TO UPPER 80S NEAR AND NORTH OF INTERSTATE 64. SATURDAY THROUGH SUNDAY...THE FLOW PATTERN WILL BECOME VERY WEAK AT LOWER AND MID LEVELS. ANY EXPANSION OF THE RIDGE WILL BE VERY SLIGHT. ISOLATED DIURNALLY INDUCED CONVECTION IS POSSIBLE BOTH DAYS...BUT NOT ENOUGH TO WARRANT POPS IN MOST AREAS. ALONG AND WEST OF THE MISSISSIPPI VALLEY...WILL MENTION SLIGHT CHANCE POPS DUE TO THE STRONGER INSTABILITY AND HIGHER DEW POINTS IN THAT AREA. HIGHS SHOULD GENERALLY BE IN THE LOWER 90S WITH LOWS IN THE LOWER 70S. && .AVIATION... ISSUED AT 621 PM CDT SUN JUL 19 2015 AN ISOLATED SHOWER/THUNDERSTORM MAY CONTINUE IN THE VICINITY OF KOWB EARLY THIS EVENING. WILL RE-INTRODUCE VICINITY SHOWERS/THUNDERSTORMS AT ALL TAF SITES OVERNIGHT AS A WEAK COLD FRONT PUSHES SOUTH TOWARD THE REGION WITH SUPPORT FROM AN UPPER LEVEL DISTURBANCE. WILL ALSO INCLUDE A VICINITY THUNDERSTORM AT KEVV AND KOWB LATE MONDAY AFTERNOON. WINDS WILL EITHER BE LIGHT AND VARIABLE OR OUT OF THE SOUTHWEST TO WEST AOB 6 KNOTS TONIGHT WITH A SLIGHT INCREASE MONDAY. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...DRS LONG TERM...MY
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
130 PM CDT MON JUL 20 2015 .AVIATION... RIDGE ALOFT WITH KEEP STORMS AND CLOUDS IN CHECK ACROSS SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA. STORMS OVER EASTERN LOUISIANA WILL MOVE INTO SOUTH-CENTRAL LOUISIANA DURING THE LATE AFTERNOON HOURS. THIS PRECIP LOOKS TO BE LIMITED ATTM. BUT THOSE LCTNS GETTING THE STORMS WILL SEE LWR CLD DECKS. CONDS TO IMPROVE TWRDS SS. && .PREV DISCUSSION... /ISSUED 1047 AM CDT MON JUL 20 2015/ DISCUSSION... GENERALLY DRY HOT AND HUMID CONDITIONS EXPECTED AGAIN TODAY AS HIGH PRES REMAINS ANCHORED OVER THE REGION. A FEW SHOWERS OR TSTMS WILL BE POSSIBLE MAINLY DURING THE AFTN AND PRIMARILY ACRS PORTIONS OF ACADIANA AND THE LOWER ATCHAFALAYA BASIN. MEANWHILE...THE BIGGEST ISSUE WILL BE THE ONGOING HEAT WITH TEMPERATURES ALREADY NEAR 90 DEGREES AT 10 AM THIS MORNING ON THEIR WAY TO HIGHS IN THE MIDDLE AND UPPER 90S. COMBINED WITH THE HUMIDITY...HEAT INDEX VALUES WILL BE WELL ABV 100 DEGREES WITH SEVERAL LOCATIONS ACRS THE ERN HALF OF THE AREA APPROACHING 110. THE HEAT ADVISORY REMAINS IN EFFECT FOR AREAS EAST OF AN ALEXANDRIA TO EUNICE TO PECAN ISLAND LINE THROUGH EARLY THIS EVENING. OVERALL...FEW CHANGES TO THE CURRENT FCST. MADE SOME MINOR ADJUSTMENTS TO THE POP/WX GRIDS TO REFLECT RECENT RADAR OBS/TRENDS...BUT THESE CHANGES WERE NOT SIGNIFICANT ENOUGH TO WARRANT AN UPDATE TO THE ZONES. 24 PREV DISCUSSION... /ISSUED 644 AM CDT MON JUL 20 2015/ AVIATION...VFR WITH LIGHT WINDS WITH THE POSSIBLE EXCEPTION OF BPT WHERE I LEFT IN THE TEMPO MVFR CIG/VIS FOR THE NEXT COUPLE OF HOURS...TROPICAL CU UNTIL THE BOUNDARY LAYER MIXES OUT AND SOME LIGHT FOG POSSIBLE AS DEW POINT SPREAD IS WITHIN A DEGREE. INCLUDED VCTS THIS AFTERNOON FOR ACADIANA TERMINALS LFT AND ARA. THE GFS AND HRRR AGREE AS DOES PERSISTENCE. SWEENEY PREV DISCUSSION... /ISSUED 347 AM CDT MON JUL 20 2015/ DISCUSSION... AREA REMAINS ON THE SOUTHERN PERIPHERY OF RIDGE CENTERED NEAR THE ARKLATEX REGION. TEMPERATURES ARE IN THE MID 70S TO LOWER 80S WITH JUST SOME HIGH CLOUDS MOVING ACROSS THE AREA. SO FAR THE RADAR IS CLEAR. GUIDANCE CONTINUES TO INDICATE LITTLE CHANGE IN THE PATTERN. THERE IS AN AREA OF DEEPER MOISTURE LOCATED ALONG THE CENTRAL GULF COAST THAT WILL BE MOVING WEST DURING THE DAY. THIS SHOULD CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH CENTRAL LOUISIANA TODAY. OUTSIDE OF THE SHOWERS AND THUNDERSTORMS...HEAT INDEX VALUES WILL BE GETTING UP OVER 108 ACROSS EASTERN PORTIONS OF THE AREA AND THE CURRENT ADVISORY STILL LOOKS GOOD. STILL LOOKS LIKE THE DEEPER MOISTURE WILL CONTINUE TO SPREAD WEST TUESDAY AND WEDNESDAY. WITH THIS MOISTURE MORE CLOUDS AND A FEW SHOWERS WILL DIAL BACK THE AFTERNOON HIGHS JUST A TAD. WHILE THERE ARE RAIN CHANCES...THE POPS ARE STILL BELOW CLIMO FOR THIS TIME OF YEAR. FOR LATE WEEK...THE CENTER OF THE RIDGE GETS A LITTLE CLOSER AND SOMEWHAT DRIER AIRMASS WILL RESULT IN LOWER POPS AND TEMPERATURES WARMING UP ONCE AGAIN. DEEPER MOISTURE IS FORECAST TO MOVE OVER DURING THE WEEKEND WITH SLIGHTLY HIGHER RAIN CHANCES...BUT STILL AT OR SLIGHTLY BELOW CLIMO. 27 && .PRELIMINARY POINT TEMPS/POPS... AEX 76 96 76 95 / 10 20 10 20 LCH 78 93 78 92 / 10 20 10 20 LFT 78 93 78 93 / 10 30 10 40 BPT 77 94 78 93 / 10 20 10 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ028-029-032-033- 043>045-052>055. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1047 AM CDT MON JUL 20 2015 .DISCUSSION... GENERALLY DRY HOT AND HUMID CONDITIONS EXPECTED AGAIN TODAY AS HIGH PRES REMAINS ANCHORED OVER THE REGION. A FEW SHOWERS OR TSTMS WILL BE POSSIBLE MAINLY DURING THE AFTN AND PRIMARILY ACRS PORTIONS OF ACADIANA AND THE LOWER ATCHAFALAYA BASIN. MEANWHILE...THE BIGGEST ISSUE WILL BE THE ONGOING HEAT WITH TEMPERATURES ALREADY NEAR 90 DEGREES AT 10 AM THIS MORNING ON THEIR WAY TO HIGHS IN THE MIDDLE AND UPPER 90S. COMBINED WITH THE HUMIDITY...HEAT INDEX VALUES WILL BE WELL ABV 100 DEGREES WITH SEVERAL LOCATIONS ACRS THE ERN HALF OF THE AREA APPROACHING 110. THE HEAT ADVISORY REMAINS IN EFFECT FOR AREAS EAST OF AN ALEXANDRIA TO EUNICE TO PECAN ISLAND LINE THROUGH EARLY THIS EVENING. OVERALL...FEW CHANGES TO THE CURRENT FCST. MADE SOME MINOR ADJUSTMENTS TO THE POP/WX GRIDS TO REFLECT RECENT RADAR OBS/TRENDS...BUT THESE CHANGES WERE NOT SIGNIFICANT ENOUGH TO WARRANT AN UPDATE TO THE ZONES. 24 && .PREV DISCUSSION... /ISSUED 644 AM CDT MON JUL 20 2015/ AVIATION...VFR WITH LIGHT WINDS WITH THE POSSIBLE EXCEPTION OF BPT WHERE I LEFT IN THE TEMPO MVFR CIG/VIS FOR THE NEXT COUPLE OF HOURS...TROPICAL CU UNTIL THE BOUNDARY LAYER MIXES OUT AND SOME LIGHT FOG POSSIBLE AS DEW POINT SPREAD IS WITHIN A DEGREE. INCLUDED VCTS THIS AFTERNOON FOR ACADIANA TERMINALS LFT AND ARA. THE GFS AND HRRR AGREE AS DOES PERSISTENCE. SWEENEY PREV DISCUSSION... /ISSUED 347 AM CDT MON JUL 20 2015/ DISCUSSION... AREA REMAINS ON THE SOUTHERN PERIPHERY OF RIDGE CENTERED NEAR THE ARKLATEX REGION. TEMPERATURES ARE IN THE MID 70S TO LOWER 80S WITH JUST SOME HIGH CLOUDS MOVING ACROSS THE AREA. SO FAR THE RADAR IS CLEAR. GUIDANCE CONTINUES TO INDICATE LITTLE CHANGE IN THE PATTERN. THERE IS AN AREA OF DEEPER MOISTURE LOCATED ALONG THE CENTRAL GULF COAST THAT WILL BE MOVING WEST DURING THE DAY. THIS SHOULD CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH CENTRAL LOUISIANA TODAY. OUTSIDE OF THE SHOWERS AND THUNDERSTORMS...HEAT INDEX VALUES WILL BE GETTING UP OVER 108 ACROSS EASTERN PORTIONS OF THE AREA AND THE CURRENT ADVISORY STILL LOOKS GOOD. STILL LOOKS LIKE THE DEEPER MOISTURE WILL CONTINUE TO SPREAD WEST TUESDAY AND WEDNESDAY. WITH THIS MOISTURE MORE CLOUDS AND A FEW SHOWERS WILL DIAL BACK THE AFTERNOON HIGHS JUST A TAD. WHILE THERE ARE RAIN CHANCES...THE POPS ARE STILL BELOW CLIMO FOR THIS TIME OF YEAR. FOR LATE WEEK...THE CENTER OF THE RIDGE GETS A LITTLE CLOSER AND SOMEWHAT DRIER AIRMASS WILL RESULT IN LOWER POPS AND TEMPERATURES WARMING UP ONCE AGAIN. DEEPER MOISTURE IS FORECAST TO MOVE OVER DURING THE WEEKEND WITH SLIGHTLY HIGHER RAIN CHANCES...BUT STILL AT OR SLIGHTLY BELOW CLIMO. 27 && .PRELIMINARY POINT TEMPS/POPS... AEX 98 76 96 76 / 10 10 20 10 LCH 94 78 93 78 / 10 10 20 10 LFT 96 78 93 78 / 20 10 30 10 BPT 95 77 94 78 / 10 10 20 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ028-029-032-033- 043>045-052>055. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
644 AM CDT MON JUL 20 2015 .AVIATION...VFR WITH LIGHT WINDS WITH THE POSSIBLE EXCEPTION OF BPT WHERE I LEFT IN THE TEMPO MVFR CIG/VIS FOR THE NEXT COUPLE OF HOURS...TROPICAL CU UNTIL THE BOUNDARY LAYER MIXES OUT AND SOME LIGHT FOG POSSIBLE AS DEW POINT SPREAD IS WITHIN A DEGREE. INCLUDED VCTS THIS AFTERNOON FOR ACADIANA TERMINALS LFT AND ARA. THE GFS AND HRRR AGREE AS DOES PERSISTENCE. SWEENEY && .PREV DISCUSSION... /ISSUED 347 AM CDT MON JUL 20 2015/ DISCUSSION... AREA REMAINS ON THE SOUTHERN PERIPHERY OF RIDGE CENTERED NEAR THE ARKLATEX REGION. TEMPERATURES ARE IN THE MID 70S TO LOWER 80S WITH JUST SOME HIGH CLOUDS MOVING ACROSS THE AREA. SO FAR THE RADAR IS CLEAR. GUIDANCE CONTINUES TO INDICATE LITTLE CHANGE IN THE PATTERN. THERE IS AN AREA OF DEEPER MOISTURE LOCATED ALONG THE CENTRAL GULF COAST THAT WILL BE MOVING WEST DURING THE DAY. THIS SHOULD CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH CENTRAL LOUISIANA TODAY. OUTSIDE OF THE SHOWERS AND THUNDERSTORMS...HEAT INDEX VALUES WILL BE GETTING UP OVER 108 ACROSS EASTERN PORTIONS OF THE AREA AND THE CURRENT ADVISORY STILL LOOKS GOOD. STILL LOOKS LIKE THE DEEPER MOISTURE WILL CONTINUE TO SPREAD WEST TUESDAY AND WEDNESDAY. WITH THIS MOISTURE MORE CLOUDS AND A FEW SHOWERS WILL DIAL BACK THE AFTERNOON HIGHS JUST A TAD. WHILE THERE ARE RAIN CHANCES...THE POPS ARE STILL BELOW CLIMO FOR THIS TIME OF YEAR. FOR LATE WEEK...THE CENTER OF THE RIDGE GETS A LITTLE CLOSER AND SOMEWHAT DRIER AIRMASS WILL RESULT IN LOWER POPS AND TEMPERATURES WARMING UP ONCE AGAIN. DEEPER MOISTURE IS FORECAST TO MOVE OVER DURING THE WEEKEND WITH SLIGHTLY HIGHER RAIN CHANCES...BUT STILL AT OR SLIGHTLY BELOW CLIMO. 27 && .PRELIMINARY POINT TEMPS/POPS... AEX 98 76 96 76 / 10 10 20 10 LCH 94 78 93 78 / 10 10 20 10 LFT 96 78 93 78 / 30 10 30 10 BPT 95 77 94 78 / 10 10 20 10 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING FOR LAZ028-029-032-033-043>045-052>055. TX...NONE. GM...NONE. && $$ AVIATION...11
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1127 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TONIGHT. AN UPPER LEVEL TROUGH WILL SWING ACROSS THE REGION ON WEDNESDAY WITH ANOTHER FRONTAL BOUNDARY FOR THURSDAY. && .NEAR TERM /THROUGH WEDNESDAY/... 11:30 PM UPDATE...MADE SOME MODIFICATIONS TO SHOWER COVERAGE WITH ONE AREA OF SHOWERS MOVING INTO HANCOCK COUNTY AND ANOTHER THIN LINE MOVING ACROSS THE NORTH. OTHERWISE, NO MAJOR CHANGES THIS HOUR. PREVIOUS DISCUSSION... SCATTERED THUNDERSTORMS EXPECTED INTO TONIGHT W/HEAVY RAINFALL POTENTIAL AND CLOUD TO GROUND LIGHTNING. SOME STRONGER STORMS COULD CONTAIN BRIEF WIND GUSTS ESPECIALLY W/THE ARRIVAL OF THE COLD FRONT LATER THIS EVENING. SPC UPDATED THE DAY1 OUTLOOK W/A MARGINAL RISK FOR WESTERN MAINE THROUGH THE EVENING. THE MAIN ACTION ATTM WAS ACROSS FAR WNW MAINE W/TRAINING CELLS AND VERY HEAVY RAINFALL PER THE LATEST RADAR LOOP. RADAR ESTIMATES OF UP TO 2"/HR IN THE STRONGER CELLS. CELLS MOVING ALONG THE UPPER SW FLOW ALLOWING FOR RE-GENERATION OF THE STORMS AND THEREFORE HEAVY RAINFALL POTENTIAL. PWATS IN THIS REGION UP AROUND 1.5 INCHES W/GOOD MOISTURE TRANSPORT FROM 925-850MBS PER THE LATEST MESO- ANALYSIS. THIS ACTIVITY WAS IGNITING ALONG A PRE- FRONTAL TROF WELL FORECASTED BY THE MIDNIGHT CREW. LOCALIZED FLOODING POSSIBLE IN THIS AREA. FURTHER E, ATMOSPHERE MORE STABLE THANKS TO A SSE FLOW AND CLOUD COVER LIMITING HEATING. ACTIVITY TO THE W IS FORECAST TO BREAK UP AS IT PUSHES E INTO THE EVENING. ANOTHER ORGANIZED LINE OF CONVECTION IS SHOWN BY MESOSCALE GUIDANCE INCLUDING THE NAM12 AND HRRR 3KM MODEL TO MOVING ACROSS THE NORTHERN 1/2 OF THE CWA THIS EVENING INTO EARLY TONIGHT. THIS ACTION WILL BE IN ASSOCIATION W/THE MAIN COLD FRONT. SOUNDING PROFILES NOT OVERLY IMPRESSIVE FOR STRONG CONVECTION, BUT MUCAPES OF 600+ JOULES AND COLUMN MOISTENING UP THROUGH 700MBS LATER THIS EVENING PLUS INCREASING MID LEVEL SHEAR WILL ALLOW FOR SOME DECENT SHOWERS/STORMS. AGAIN, HEAVY RAINFALL AND LIGHTNING THE MAIN THREAT. DECIDED TO GO W/BASIN QPF OF 1.25+ INCHES THROUGH WEST AND NORTHWEST MAINE THROUGH MIDNIGHT DUE TO THE TRAINING CELLS. ALL ACTION WILL WEAKEN AND PUSH TO THE ESE LATER TONIGHT W/COOLER AND DRIER AIR BEHIND THE FRONT BY WEDNESDAY MORNING. DECIDED TO ADD FOG INTO THE FORECAST TONIGHT BEFORE THE FROPA W/DEEP LLVL MOISTURE IN PLACE. DOWNEAST AND THE COAST WILL HAVE THE BEST SHOT AS SEEING THE FOG. UNSETTLED ON WEDNESDAY W/THE UPPER TROF AXIS FORECAST TO ACROSS THE REGION. BEST MOISTURE AVAILABLE LOOKS TO BE IN THE LLVLS AROUND 850MBS. SOME INSTABILITY IS THERE BUT MARGINAL AND LOW/MID LEVEL LAPSE RATES ARE WEAK. THEREFORE, DECIDED TO LEAN AWAY FROM THE MENTION OF TSTMS AND KEPT JUST SHOWERS ATTM. LATER CREWS CAN ASSESS THIS FURTHER W/THE LATEST GUIDANCE. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL FOR JULY. .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... THE REGION IS EXPECTED TO REMAIN IN A CYCLONIC FLOW ON THE BACK SIDE OF SURFACE LOW PRESSURE LOCATED TO THE EAST OF NOVA SCOTIA ALONG WITH AN UPPER LEVEL SYSTEM TO THE NORTHWEST. IN ADDITION THE UPPER LEVEL SYSTEM IS EXPECTED TO MOVE SOUTHEAST WARD AND CROSS OVER THE NORTHERN AND EASTERN PORTION OF MAINE FRIDAY. THIS IS EXPECTED TO RESULT IN SHOWERS... ESPECIALLY IN THE NORTH AND DURING DAYLIGHT HOURS. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND SKY. FOR MAXIMUM TEMPERATURE WILL USE THE CONSENSUS RAW. FOR MINIMUM TEMPERATURE HAVE USED THE CONSENSUS ALL. WILL USE THE MOSG25 FOR WINDS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN UPPER LOW WILL PULL AWAY FROM NEW ENGLAND FRIDAY NIGHT INTO SATURDAY, FOLLOWED BY A VERY BRIEF RIDGE OF HIGH PRESSURE. AS SUCH, THE FIRST PART OF THE WEEKEND WILL HAVE THE LOWEST CHANCES FOR RAIN, THOUGH A FEW SHOWERS CAN`T BE TOTALLY RULED OUT, ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE NORTHWEST. A SLOW- MOVING FRONTAL SYSTEM WILL THEN DRAG ITS ATTENDANT FRONT ACROSS THE GREAT LAKES AND THE NORTHEASTERN CONUS SUNDAY AND MONDAY, BRINGING A PROLONGED PERIOD OF SHOWERS AND POSSIBLE THUNDERSTORMS. THE UPPER LOW ASSOCIATED WITH THIS SYSTEM WILL THEN BRING MORE SCATTERED SHOWERS TO THE REGION ON TUESDAY. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: MVFR TO IFR TONIGHT W/SHOWERS ENDING OVERNIGHT. FOG WILL BE A THREAT FOR KBGR AND KBHB INTO EARLY WEDNESDAY W/CONDITIONS IMPROVING TO VFR BY MIDDAY. THE CAVEAT TO THIS WILL BE ACROSS THE NORTHERN TERMINALS AS CIGS COULD DROP TO MVFR FOR A PERIOD WEDNESDAY AFTERNOON. SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THEN MVFR/VFR CONDITIONS THURSDAY THROUGH FRIDAY. && .MARINE... NEAR TERM: FOG KEEPING NAVIGATION TRICKY W/VSBYS BELOW 1 NM. KEPT FOG THROUGH MIDDAY WEDNESDAY UNTIL GOOD MIXING W/WINDS VEERING TO THE W ALLOWING FOR CLEARING. BROUGHT WINDS UP TO 10-15KT WEDNESDAY MORNING BEHIND THE FRONT. WAVE HEIGHTS TO BE NO MORE THAN 3 FT AND THIS WILL BE MAINLY OVER THE OUTER WATERS. SHORT TERM: FOR SUSTAINED WINDS HAVE USED A 50/50 BLEND OF THE NAM12 AND GFS40. FOR WAVES: WITH LIGHT WINDS EXPECTED WEDNESDAY NIGHT THROUGH FRIDAY THE PRIMARY WAVE SYSTEMS WILL BE COMPOSED OF LONG PERIOD WAVE GROUPS COMBINING TO PRODUCE 1 TO 2 FOOT SEAS. THE COMBINED SEAS COMPOSED OF SOUTHERLY 6 SECOND GROUP AND SOUTHEASTERLY 9-10 SECOND GROUP. WILL USE THE NEAR SHORE WAVE MODEL TO POPULATE WAVE HEIGHT GRIDS. && .CLIMATE... YEAR TO DATE IT IS STILL THE COLDEST YEAR ON RECORD AT BANGOR AND HOULTON, AND THE 6TH COOLEST AT CARIBOU. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...CB/HEWITT/MCB SHORT TERM...MIGNONE LONG TERM...HASTINGS AVIATION...CB/HEWITT/MIGNONE MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
923 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT WILL CROSS THE AREA TONIGHT. AN UPPER LEVEL TROUGH WILL SWING ACROSS THE REGION ON WEDNESDAY WITH ANOTHER FRONTAL BOUNDARY FOR THURSDAY. && .NEAR TERM /THROUGH WEDNESDAY/... 923 PM UPDATE...A COLD FRONT IS PUSHING INTO WESTERN MAINE THIS EVENING AND WILL PUSH OFF THE DOWNEAST COAST BY MORNING. MOST OF THE SHOWER ACTIVITY IS AHEAD OF THE FRONT. THUNDERSTORMS HAVE DIED OFF QUICKLY THIS EVENING WITH NO CLOUD TO GROUND LIGHTNING STRIKES DETECTED WITHIN THE PAST 90 MINUTES. THERE WILL STILL BE SOME HEAVY DOWNPOURS WITH PWATS OF 1.34" ON THE 00Z KCAR SOUNDING. THE ONGOING FORECAST IS IN GREAT SHAPE...JUST SOME MINOR TWEAKS BASED ON THE 9 PM OBSERVATIONS...AND THE RADAR AND NEAR TERM MODEL TRENDS. PREVIOUS DISCUSSION... SCATTERED THUNDERSTORMS EXPECTED INTO TONIGHT W/HEAVY RAINFALL POTENTIAL AND CLOUD TO GROUND LIGHTNING. SOME STRONGER STORMS COULD CONTAIN BRIEF WIND GUSTS ESPECIALLY W/THE ARRIVAL OF THE COLD FRONT LATER THIS EVENING. SPC UPDATED THE DAY1 OUTLOOK W/A MARGINAL RISK FOR WESTERN MAINE THROUGH THE EVENING. THE MAIN ACTION ATTM WAS ACROSS FAR WNW MAINE W/TRAINING CELLS AND VERY HEAVY RAINFALL PER THE LATEST RADAR LOOP. RADAR ESTIMATES OF UP TO 2"/HR IN THE STRONGER CELLS. CELLS MOVING ALONG THE UPPER SW FLOW ALLOWING FOR RE-GENERATION OF THE STORMS AND THEREFORE HEAVY RAINFALL POTENTIAL. PWATS IN THIS REGION UP AROUND 1.5 INCHES W/GOOD MOISTURE TRANSPORT FROM 925-850MBS PER THE LATEST MESO- ANALYSIS. THIS ACTIVITY WAS IGNITING ALONG A PRE- FRONTAL TROF WELL FORECASTED BY THE MIDNIGHT CREW. LOCALIZED FLOODING POSSIBLE IN THIS AREA. FURTHER E, ATMOSPHERE MORE STABLE THANKS TO A SSE FLOW AND CLOUD COVER LIMITING HEATING. ACTIVITY TO THE W IS FORECAST TO BREAK UP AS IT PUSHES E INTO THE EVENING. ANOTHER ORGANIZED LINE OF CONVECTION IS SHOWN BY MESOSCALE GUIDANCE INCLUDING THE NAM12 AND HRRR 3KM MODEL TO MOVING ACROSS THE NORTHERN 1/2 OF THE CWA THIS EVENING INTO EARLY TONIGHT. THIS ACTION WILL BE IN ASSOCIATION W/THE MAIN COLD FRONT. SOUNDING PROFILES NOT OVERLY IMPRESSIVE FOR STRONG CONVECTION, BUT MUCAPES OF 600+ JOULES AND COLUMN MOISTENING UP THROUGH 700MBS LATER THIS EVENING PLUS INCREASING MID LEVEL SHEAR WILL ALLOW FOR SOME DECENT SHOWERS/STORMS. AGAIN, HEAVY RAINFALL AND LIGHTNING THE MAIN THREAT. DECIDED TO GO W/BASIN QPF OF 1.25+ INCHES THROUGH WEST AND NORTHWEST MAINE THROUGH MIDNIGHT DUE TO THE TRAINING CELLS. ALL ACTION WILL WEAKEN AND PUSH TO THE ESE LATER TONIGHT W/COOLER AND DRIER AIR BEHIND THE FRONT BY WEDNESDAY MORNING. DECIDED TO ADD FOG INTO THE FORECAST TONIGHT BEFORE THE FROPA W/DEEP LLVL MOISTURE IN PLACE. DOWNEAST AND THE COAST WILL HAVE THE BEST SHOT AS SEEING THE FOG. UNSETTLED ON WEDNESDAY W/THE UPPER TROF AXIS FORECAST TO ACROSS THE REGION. BEST MOISTURE AVAILABLE LOOKS TO BE IN THE LLVLS AROUND 850MBS. SOME INSTABILITY IS THERE BUT MARGINAL AND LOW/MID LEVEL LAPSE RATES ARE WEAK. THEREFORE, DECIDED TO LEAN AWAY FROM THE MENTION OF TSTMS AND KEPT JUST SHOWERS ATTM. LATER CREWS CAN ASSESS THIS FURTHER W/THE LATEST GUIDANCE. TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL FOR JULY. .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... THE REGION IS EXPECTED TO REMAIN IN A CYCLONIC FLOW ON THE BACK SIDE OF SURFACE LOW PRESSURE LOCATED TO THE EAST OF NOVA SCOTIA ALONG WITH AN UPPER LEVEL SYSTEM TO THE NORTHWEST. IN ADDITION THE UPPER LEVEL SYSTEM IS EXPECTED TO MOVE SOUTHEAST WARD AND CROSS OVER THE NORTHERN AND EASTERN PORTION OF MAINE FRIDAY. THIS IS EXPECTED TO RESULT IN SHOWERS... ESPECIALLY IN THE NORTH AND DURING DAYLIGHT HOURS. WILL BLEND THE GFS AND ECMWF FOR POPS... QPF AND SKY. FOR MAXIMUM TEMPERATURE WILL USE THE CONSENSUS RAW. FOR MINIMUM TEMPERATURE HAVE USED THE CONSENSUS ALL. WILL USE THE MOSG25 FOR WINDS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN UPPER LOW WILL PULL AWAY FROM NEW ENGLAND FRIDAY NIGHT INTO SATURDAY, FOLLOWED BY A VERY BRIEF RIDGE OF HIGH PRESSURE. AS SUCH, THE FIRST PART OF THE WEEKEND WILL HAVE THE LOWEST CHANCES FOR RAIN, THOUGH A FEW SHOWERS CAN`T BE TOTALLY RULED OUT, ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE NORTHWEST. A SLOW- MOVING FRONTAL SYSTEM WILL THEN DRAG ITS ATTENDANT FRONT ACROSS THE GREAT LAKES AND THE NORTHEASTERN CONUS SUNDAY AND MONDAY, BRINGING A PROLONGED PERIOD OF SHOWERS AND POSSIBLE THUNDERSTORMS. THE UPPER LOW ASSOCIATED WITH THIS SYSTEM WILL THEN BRING MORE SCATTERED SHOWERS TO THE REGION ON TUESDAY. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: MVFR TO IFR TONIGHT W/SHOWERS ENDING OVERNIGHT. FOG WILL BE A THREAT FOR KBGR AND KBHB INTO EARLY WEDNESDAY W/CONDITIONS IMPROVING TO VFR BY MIDDAY. THE CAVEAT TO THIS WILL BE ACROSS THE NORTHERN TERMINALS AS CIGS COULD DROP TO MVFR FOR A PERIOD WEDNESDAY AFTERNOON. SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THEN MVFR/VFR CONDITIONS THURSDAY THROUGH FRIDAY. && .MARINE... NEAR TERM: FOG KEEPING NAVIGATION TRICKY W/VSBYS BELOW 1 NM. KEPT FOG THROUGH MIDDAY WEDNESDAY UNTIL GOOD MIXING W/WINDS VEERING TO THE W ALLOWING FOR CLEARING. BROUGHT WINDS UP TO 10-15KT WEDNESDAY MORNING BEHIND THE FRONT. WAVE HEIGHTS TO BE NO MORE THAN 3 FT AND THIS WILL BE MAINLY OVER THE OUTER WATERS. SHORT TERM: FOR SUSTAINED WINDS HAVE USED A 50/50 BLEND OF THE NAM12 AND GFS40. FOR WAVES: WITH LIGHT WINDS EXPECTED WEDNESDAY NIGHT THROUGH FRIDAY THE PRIMARY WAVE SYSTEMS WILL BE COMPOSED OF LONG PERIOD WAVE GROUPS COMBINING TO PRODUCE 1 TO 2 FOOT SEAS. THE COMBINED SEAS COMPOSED OF SOUTHERLY 6 SECOND GROUP AND SOUTHEASTERLY 9-10 SECOND GROUP. WILL USE THE NEAR SHORE WAVE MODEL TO POPULATE WAVE HEIGHT GRIDS. && .CLIMATE...YEAR TO DATE IT IS STILL THE COLDEST YEAR ON RECORD AT BANGOR AND HOULTON, AND THE 6TH COOLEST AT CARIBOU. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. MARINE...NONE. && $$ NEAR TERM...CB/HEWITT SHORT TERM...MIGNONE LONG TERM...HASTINGS AVIATION...CB/HEWITT/MIGNONE MARINE...CB/HEWITT/MIGNONE CLIMATE...CB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
328 PM EDT MON JUL 20 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM EDT MON JUL 20 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALOFT ALONG THE CNDN BORDER E OF AN UPR RDG OVER THE ROCKIES. SHRTWV AND ASSOCIATED SFC LO EMBEDDED IN THIS FLOW ARE MOVING THRU NW ONTARIO...WITH ATTENDANT SFC COLD FNT STRETCHING INTO MN. SOME ISOLD SHOWERS ARE PRESENT JUST AHEAD OF THIS FNT AND MOVING THRU NW LK SUP TOWARD THE KEWEENAW. BUT WITH AN ABSENCE OF MSTR INFLOW INTO THE SHRTWV AND NOCTURNAL COOLING...THESE SHOWERS HAVE TENDED TO DIMINISH WITH TIME TO THE S OF SHARPER DPVA/DEEP LYR QVECTOR CNVGC PASSING TO THE N CLOSER TO THE SHRTWV TRACK. OTRW...STEADY WSW WINDS AHEAD OF THE FNT ARE RESULTING IN WELL ABV NORMAL TEMPS EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON POPS TODAY ASSOCIATED WITH APRCHG COLD FNT AS WELL AS GUSTY WINDS. TODAY...SHRTWV MOVING THRU NW ONTARIO JUST N OF LK SUP IS FCST TO MOVE QUICKLY ESEWD TO NEAR THE QUEBEC/ONTARIO BORDER BY 00Z THIS EVNG. ATTENDANT COLD FNT IS PROGGED TO SWING THRU THE CWA...REACHING THE SE ZNS ARND 18Z BEFORE CONTINUING AWAY TO THE SE IN THE AFTN. WHILE THERE MAY BE SOME ISOLATED SHOWERS THIS MRNG OVER MAINLY THE NRN TIER CLOSER TO THE SHRTWV TRACK/CORE OF SHARPER FORCING...EXPECT A MAINLY DRY FROPA BECAUSE THE TIMING WL BE AHEAD OF THE FULL IMPACT OF DAYTIME HEATING. A BIT CONCERNED THE LATER ARRIVAL EARLY THIS AFTN OVER THE SE CWA WITH SOME ENHANCED LLVL CNVGC WITH LK BREEZE OFF LK MI COULD RESULT IN SOME ISOLD SHOWERS/TS THERE AS HINTED AT BY SOME OF THE HIER RES MODELS...SO DID MENTION SOME SCHC POPS IN THIS AREA BEFORE MORE VIGOROUS DRYING AND THE ARRIVAL OF LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC ENDS THE PCPN CHCS BY LATE AFTN. EXPECT SOME GUSTY WINDS AGAIN TODAY AHEAD OF AND FOLLOWING THE COLD FROPA WITH H925 WSW WINDS UP TO 25-30 KTS SHIFTING TO THE WNW IN THE AFTN. EXPECT THE HIEST MAX TEMPS INTO THE 80S OVER THE SCNTRAL. COOL AIR ADVECTION IN THE WAKE OF THE FROPA WITH H85 TEMPS PROGGED TO FALL TO NEAR 10C OVER THE NW CWA BY 00Z WL LIMIT THE DAYTIME DIURNAL TEMP RISE TO THE NW. TNGT...ANOTHER SHRTWV/SOME MID LVL MSTR ARE FCST TO SWING SE INTO THE UPR LKS WITHIN DEEPENING UPR TROF. WHILE THERE MAY BE SOME CLDS ACCOMPANYING THIS DISTURBANCE...NONE OF THE MODELS SHOW ANY PCPN OVER UPR MI. WL MAINTAIN A DRY FCST DURING PERIOD OF NOCTURNAL COOLING. OVERNGT LOWS WL BE QUITE A BIT LOWER THAN THIS MRNG WITH SOME UPR 40S AT SOME OF THE COOL SPOTS. BUT STEADY NW WINDS WL TEND TO LIMIT THE TEMP DROP. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 328 PM EDT MON JUL 20 2015 A FAIRLY QUIET LONG TERM FORECAST IS IN STORE FOR UPPER MICHIGAN...AS THE UPPER GREAT LAKES REGION WILL BE INCREASINGLY INFLUENCED BY AN UPPER RIDGE. AS THIS OCCURS...A HIGH PRESSURE RIDGE STRETCHING FROM NORTHERN MANITOBA TO THE MID MISSISSIPPI VALLEY ON TUESDAY EVENING WILL SLOWLY PUSH EAST ACROSS THE REGION THROUGH THURSDAY...BEFORE DEPARTING BY FRIDAY MORNING. WILL MODELS SHOWING LIMITED MOISTURE...EXPECT MOSTLY CLEAR SKIES THROUGH MUCH OF THE PERIOD AND MAYBE JUST A FEW DIURNAL CU DURING THE AFTERNOON HOURS. A FEW MODELS ARE SHOWING A WEAK SHORTWAVE UNDERCUTTING THE RIDGE WEDNESDAY AFTERNOON IN THE DAKOTAS AND THEN NEARING THE AREA ON WEDNESDAY NIGHT INTO THURSDAY...BUT AT THIS POINT...THINK THE PRECIPITATION SHOULD STAY TO THE SOUTHWEST OF THE AREA AND KEPT THE SLIGHT CHANCE POPS ALONG OR JUST SOUTHWEST OF THE WISCONSIN BORDER OVER THE WESTERN U.P. TEMPERATURES DURING THIS PERIOD LOOK TO BE NEAR NORMAL WITH DEEP MIXING DURING MOST AFTERNOONS. DID TREND DEWPOINTS DOWN A COUPLE DEGREES ON WEDNESDAY...WHICH PUSHES RH VALUES INTO THE LOWER 30S. BUT WITH WINDS GENERALLY STAYING BELOW 15KTS...THINK FIRE WEATHER CONCERNS WILL BE LIMITED EVEN WITH THE RECENT DRIER WEATHER. THE BEST CHANCE FOR PRECIPITATION WILL COME LATE FRIDAY INTO THE FIRST HALF OF THE WEEKEND...AS THE UPPER TROUGH CURRENTLY MOVING THROUGH BRITISH COLUMBIA WILL MAKE ITS WAY EAST THROUGH SOUTHERN CANADA THIS WEEK BEFORE LIFTING NORTHEAST TOWARDS HUDSON BAY BY SATURDAY. THIS NORTHEAST MOVEMENT AS THE WAVE AND ASSOCIATED SURFACE TROUGH NEARS THE AREA HAS THE POTENTIAL TO LIMIT THE AMOUNT OF PRECIPITATION THAT OCCURS AND IN TURN WILL LIMIT THE POPS FROM BEING ABOVE THE CHANCE CATEGORY. AT THIS POINT...BEST CHANCE LOOKS TO BE OVER THE WESTERN HALF OF THE U.P. WHERE THEY WILL BE ASSISTED BY THE BETTER TIMING WITH PEAK HEATING THUNDERSTORMS OVER NORTHEAST MINNESOTA MOVING INTO THE AREA. BEHIND THAT WAVE...AN UPPER RIDGE AND HIGH PRESSURE WILL BUILD BACK INTO THE UPPER GREAT LAKES REGION FOR THE END OF THE WEEKEND AND EARLY NEXT WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 150 PM EDT MON JUL 20 2015 EXPANSION OF CU/SC CLOUDS ACROSS TAF SITES INTO MID AFTN WITH CLOUDS SCATTERING OUT BY EVENING. CONDITIONS WILL REMAIN VFR. ONLY OTHER ISSUE TODAY WILL BE GUSTY WEST WINDS...OVER 30 KTS INTO MID AFTN AT KCMX...AND RESULTING IN CROSSWIND AT KSAW. WINDS WILL DIMINISH THIS EVENING AT ALL TAF SITES WITH LOSS OF DAYTIME HEATING. VFR CONDITIONS WL CONTINUE TNGT BUT THERE MAY BE LINGERING SCT-BKN MID CLOUDS. MORE VFR CU/SC EXPECTED ON TUESDAY. WEST WINDS COULD BE GUSTY AGAIN WITH OVER 20 KTS POSSIBLE AT KCMX IN THE AFTN. MORE TYPICAL LAKE BREEZE DIRECTIONS EXPECTED AT KIWD AND KSAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 340 AM EDT MON JUL 20 2015 LOW PRESSURE FROM W ONTARIO TO JUST NW OF JAMES BAY WILL SWING INTO S HUDSON BAY AND W QUEBEC TODAY WHILE DRAGGING A TROUGH ACROSS LAKE SUPERIOR. WITH THE TIGHT PRESSURE GRADIENT...25KT WINDS WILL REMAIN POSSIBLE ACROSS LAKE SUPERIOR. A LARGE AREA OF HIGH PRESSURE FROM S CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES TONIGHT WILL SLOWLY EDGE E...AND BUILD ACROSS THE UPPER GREAT LAKES THROUGH THURSDAY...WITH WINDS RETURNING TO AROUND 20KTS OR LESS. VERY PATCHY FOG /MAINLY N/ WILL ALSO DIMINISH MONDAY. EXPECT A N PLAINS LOW THURSDAY NIGHT TO SHIFT TO N ONTARIO BY THE END OF THE DAY FRIDAY...WITH A TROUGH PUSHING ACROSS MINNESOTA AND W LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...SRF AVIATION...JLA MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
153 PM EDT MON JUL 20 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM EDT MON JUL 20 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALOFT ALONG THE CNDN BORDER E OF AN UPR RDG OVER THE ROCKIES. SHRTWV AND ASSOCIATED SFC LO EMBEDDED IN THIS FLOW ARE MOVING THRU NW ONTARIO...WITH ATTENDANT SFC COLD FNT STRETCHING INTO MN. SOME ISOLD SHOWERS ARE PRESENT JUST AHEAD OF THIS FNT AND MOVING THRU NW LK SUP TOWARD THE KEWEENAW. BUT WITH AN ABSENCE OF MSTR INFLOW INTO THE SHRTWV AND NOCTURNAL COOLING...THESE SHOWERS HAVE TENDED TO DIMINISH WITH TIME TO THE S OF SHARPER DPVA/DEEP LYR QVECTOR CNVGC PASSING TO THE N CLOSER TO THE SHRTWV TRACK. OTRW...STEADY WSW WINDS AHEAD OF THE FNT ARE RESULTING IN WELL ABV NORMAL TEMPS EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON POPS TODAY ASSOCIATED WITH APRCHG COLD FNT AS WELL AS GUSTY WINDS. TODAY...SHRTWV MOVING THRU NW ONTARIO JUST N OF LK SUP IS FCST TO MOVE QUICKLY ESEWD TO NEAR THE QUEBEC/ONTARIO BORDER BY 00Z THIS EVNG. ATTENDANT COLD FNT IS PROGGED TO SWING THRU THE CWA...REACHING THE SE ZNS ARND 18Z BEFORE CONTINUING AWAY TO THE SE IN THE AFTN. WHILE THERE MAY BE SOME ISOLATED SHOWERS THIS MRNG OVER MAINLY THE NRN TIER CLOSER TO THE SHRTWV TRACK/CORE OF SHARPER FORCING...EXPECT A MAINLY DRY FROPA BECAUSE THE TIMING WL BE AHEAD OF THE FULL IMPACT OF DAYTIME HEATING. A BIT CONCERNED THE LATER ARRIVAL EARLY THIS AFTN OVER THE SE CWA WITH SOME ENHANCED LLVL CNVGC WITH LK BREEZE OFF LK MI COULD RESULT IN SOME ISOLD SHOWERS/TS THERE AS HINTED AT BY SOME OF THE HIER RES MODELS...SO DID MENTION SOME SCHC POPS IN THIS AREA BEFORE MORE VIGOROUS DRYING AND THE ARRIVAL OF LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC ENDS THE PCPN CHCS BY LATE AFTN. EXPECT SOME GUSTY WINDS AGAIN TODAY AHEAD OF AND FOLLOWING THE COLD FROPA WITH H925 WSW WINDS UP TO 25-30 KTS SHIFTING TO THE WNW IN THE AFTN. EXPECT THE HIEST MAX TEMPS INTO THE 80S OVER THE SCNTRAL. COOL AIR ADVECTION IN THE WAKE OF THE FROPA WITH H85 TEMPS PROGGED TO FALL TO NEAR 10C OVER THE NW CWA BY 00Z WL LIMIT THE DAYTIME DIURNAL TEMP RISE TO THE NW. TNGT...ANOTHER SHRTWV/SOME MID LVL MSTR ARE FCST TO SWING SE INTO THE UPR LKS WITHIN DEEPENING UPR TROF. WHILE THERE MAY BE SOME CLDS ACCOMPANYING THIS DISTURBANCE...NONE OF THE MODELS SHOW ANY PCPN OVER UPR MI. WL MAINTAIN A DRY FCST DURING PERIOD OF NOCTURNAL COOLING. OVERNGT LOWS WL BE QUITE A BIT LOWER THAN THIS MRNG WITH SOME UPR 40S AT SOME OF THE COOL SPOTS. BUT STEADY NW WINDS WL TEND TO LIMIT THE TEMP DROP. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 340 AM EDT MON JUL 20 2015 IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE. POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION LATE FRI INTO EARLY SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT. MAY SEE A LIGHT SHOWER OR TWO ON TUE AFTERNOON AS A SHORTWAVE MAY PASS THROUGH...BUT WILL LEAVE THE FORECAST DRY FOR NOW GIVEN LIMITED COVERAGE/PRECIP AMOUNT/CONFIDENCE. MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER LATE WED INTO THU NIGHT AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE SW ALONG WITH MOISTURE ADVECTION. WILL KEEP POPS SW OF THE CWA ON WED...BUT WILL CONTINUE TO BRING SLIGHT CHANCE POPS INTO AREAS ALONG THE WI BORDER WED NIGHT AND THU AS THE FRONT SLOWLY MOVES NE. TIMING/LOCATION MAY BE CHANGED IF ANY DISTURBANCES FORM THAT CAUSE THE FRONT/MOISTURE ADVECTION TO SURGE FARTHER N. THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES BETWEEN MODELS WITH THIS SYSTEM...WITH THE GFS BEING STRONGER AND CONSIDERABLY FARTHER S THAN THE ECMWF. WILL USE CONSENSUS GUIDANCE GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH SAT. SUN LOOKS DRY FOR NOW. TEMPS WILL BE COOLEST TUE AND WED WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS EXPECTED. AN UPPER RIDGE MOVES OVER THE AREA LATE IN THE WEEK AHEAD OF THE CANADIAN DISTURBANCE...LEADING TO NEAR NORMAL TEMPS THU AND ABOVE NORMAL TEMPS FRI THROUGH SUN. LOOKS LIKE UPPER RIDGING W OF THE REGION IS FOR THE MOST PART HERE TO STAY THROUGH THE END OF JULY...WITH ABOVE NORMAL TEMPS. CFS ALSO POINTS TO ABOVE NORMAL TEMPS THROUGH MOST OF THE REST OF THE MONTH...WITH BELOW NORMAL TEMPS TO START AUGUST OFF. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 150 PM EDT MON JUL 20 2015 EXPANSION OF CU/SC CLOUDS ACROSS TAF SITES INTO MID AFTN WITH CLOUDS SCATTERING OUT BY EVENING. CONDITIONS WILL REMAIN VFR. ONLY OTHER ISSUE TODAY WILL BE GUSTY WEST WINDS...OVER 30 KTS INTO MID AFTN AT KCMX...AND RESULTING IN CROSSWIND AT KSAW. WINDS WILL DIMINISH THIS EVENING AT ALL TAF SITES WITH LOSS OF DAYTIME HEATING. VFR CONDITIONS WL CONTINUE TNGT BUT THERE MAY BE LINGERING SCT-BKN MID CLOUDS. MORE VFR CU/SC EXPECTED ON TUESDAY. WEST WINDS COULD BE GUSTY AGAIN WITH OVER 20 KTS POSSIBLE AT KCMX IN THE AFTN. MORE TYPICAL LAKE BREEZE DIRECTIONS EXPECTED AT KIWD AND KSAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 340 AM EDT MON JUL 20 2015 LOW PRESSURE FROM W ONTARIO TO JUST NW OF JAMES BAY WILL SWING INTO S HUDSON BAY AND W QUEBEC TODAY WHILE DRAGGING A TROUGH ACROSS LAKE SUPERIOR. WITH THE TIGHT PRESSURE GRADIENT...25KT WINDS WILL REMAIN POSSIBLE ACROSS LAKE SUPERIOR. A LARGE AREA OF HIGH PRESSURE FROM S CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES TONIGHT WILL SLOWLY EDGE E...AND BUILD ACROSS THE UPPER GREAT LAKES THROUGH THURSDAY...WITH WINDS RETURNING TO AROUND 20KTS OR LESS. VERY PATCHY FOG /MAINLY N/ WILL ALSO DIMINISH MONDAY. EXPECT A N PLAINS LOW THURSDAY NIGHT TO SHIFT TO N ONTARIO BY THE END OF THE DAY FRIDAY...WITH A TROUGH PUSHING ACROSS MINNESOTA AND W LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...JLA MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 AM EDT MON JUL 20 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM EDT MON JUL 20 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALOFT ALONG THE CNDN BORDER E OF AN UPR RDG OVER THE ROCKIES. SHRTWV AND ASSOCIATED SFC LO EMBEDDED IN THIS FLOW ARE MOVING THRU NW ONTARIO...WITH ATTENDANT SFC COLD FNT STRETCHING INTO MN. SOME ISOLD SHOWERS ARE PRESENT JUST AHEAD OF THIS FNT AND MOVING THRU NW LK SUP TOWARD THE KEWEENAW. BUT WITH AN ABSENCE OF MSTR INFLOW INTO THE SHRTWV AND NOCTURNAL COOLING...THESE SHOWERS HAVE TENDED TO DIMINISH WITH TIME TO THE S OF SHARPER DPVA/DEEP LYR QVECTOR CNVGC PASSING TO THE N CLOSER TO THE SHRTWV TRACK. OTRW...STEADY WSW WINDS AHEAD OF THE FNT ARE RESULTING IN WELL ABV NORMAL TEMPS EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON POPS TODAY ASSOCIATED WITH APRCHG COLD FNT AS WELL AS GUSTY WINDS. TODAY...SHRTWV MOVING THRU NW ONTARIO JUST N OF LK SUP IS FCST TO MOVE QUICKLY ESEWD TO NEAR THE QUEBEC/ONTARIO BORDER BY 00Z THIS EVNG. ATTENDANT COLD FNT IS PROGGED TO SWING THRU THE CWA...REACHING THE SE ZNS ARND 18Z BEFORE CONTINUING AWAY TO THE SE IN THE AFTN. WHILE THERE MAY BE SOME ISOLATED SHOWERS THIS MRNG OVER MAINLY THE NRN TIER CLOSER TO THE SHRTWV TRACK/CORE OF SHARPER FORCING...EXPECT A MAINLY DRY FROPA BECAUSE THE TIMING WL BE AHEAD OF THE FULL IMPACT OF DAYTIME HEATING. A BIT CONCERNED THE LATER ARRIVAL EARLY THIS AFTN OVER THE SE CWA WITH SOME ENHANCED LLVL CNVGC WITH LK BREEZE OFF LK MI COULD RESULT IN SOME ISOLD SHOWERS/TS THERE AS HINTED AT BY SOME OF THE HIER RES MODELS...SO DID MENTION SOME SCHC POPS IN THIS AREA BEFORE MORE VIGOROUS DRYING AND THE ARRIVAL OF LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC ENDS THE PCPN CHCS BY LATE AFTN. EXPECT SOME GUSTY WINDS AGAIN TODAY AHEAD OF AND FOLLOWING THE COLD FROPA WITH H925 WSW WINDS UP TO 25-30 KTS SHIFTING TO THE WNW IN THE AFTN. EXPECT THE HIEST MAX TEMPS INTO THE 80S OVER THE SCNTRAL. COOL AIR ADVECTION IN THE WAKE OF THE FROPA WITH H85 TEMPS PROGGED TO FALL TO NEAR 10C OVER THE NW CWA BY 00Z WL LIMIT THE DAYTIME DIURNAL TEMP RISE TO THE NW. TNGT...ANOTHER SHRTWV/SOME MID LVL MSTR ARE FCST TO SWING SE INTO THE UPR LKS WITHIN DEEPENING UPR TROF. WHILE THERE MAY BE SOME CLDS ACCOMPANYING THIS DISTURBANCE...NONE OF THE MODELS SHOW ANY PCPN OVER UPR MI. WL MAINTAIN A DRY FCST DURING PERIOD OF NOCTURNAL COOLING. OVERNGT LOWS WL BE QUITE A BIT LOWER THAN THIS MRNG WITH SOME UPR 40S AT SOME OF THE COOL SPOTS. BUT STEADY NW WINDS WL TEND TO LIMIT THE TEMP DROP. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 340 AM EDT MON JUL 20 2015 IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE. POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION LATE FRI INTO EARLY SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT. MAY SEE A LIGHT SHOWER OR TWO ON TUE AFTERNOON AS A SHORTWAVE MAY PASS THROUGH...BUT WILL LEAVE THE FORECAST DRY FOR NOW GIVEN LIMITED COVERAGE/PRECIP AMOUNT/CONFIDENCE. MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER LATE WED INTO THU NIGHT AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE SW ALONG WITH MOISTURE ADVECTION. WILL KEEP POPS SW OF THE CWA ON WED...BUT WILL CONTINUE TO BRING SLIGHT CHANCE POPS INTO AREAS ALONG THE WI BORDER WED NIGHT AND THU AS THE FRONT SLOWLY MOVES NE. TIMING/LOCATION MAY BE CHANGED IF ANY DISTURBANCES FORM THAT CAUSE THE FRONT/MOISTURE ADVECTION TO SURGE FARTHER N. THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES BETWEEN MODELS WITH THIS SYSTEM...WITH THE GFS BEING STRONGER AND CONSIDERABLY FARTHER S THAN THE ECMWF. WILL USE CONSENSUS GUIDANCE GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH SAT. SUN LOOKS DRY FOR NOW. TEMPS WILL BE COOLEST TUE AND WED WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS EXPECTED. AN UPPER RIDGE MOVES OVER THE AREA LATE IN THE WEEK AHEAD OF THE CANADIAN DISTURBANCE...LEADING TO NEAR NORMAL TEMPS THU AND ABOVE NORMAL TEMPS FRI THROUGH SUN. LOOKS LIKE UPPER RIDGING W OF THE REGION IS FOR THE MOST PART HERE TO STAY THROUGH THE END OF JULY...WITH ABOVE NORMAL TEMPS. CFS ALSO POINTS TO ABOVE NORMAL TEMPS THROUGH MOST OF THE REST OF THE MONTH...WITH BELOW NORMAL TEMPS TO START AUGUST OFF. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 720 AM EDT MON JUL 20 2015 ALTHOUGH THERE MAY BE AN EXPANSION OF SC TODAY AS SOME MOISTER AIR ARRIVES FM THE NW FOLLOWING A MORNING COLD FROPA...TIMING DURING PERIOD OF DIURNAL HEATING SUGGESTS VFR CIGS WL PREVAIL. MIXING ASSOCIATED WITH THIS HEATING WL ALSO RESULT IN GUSTY WINDS... ESPECIALLY AT THE MORE EXPOSED CMX LOCATION. WINDS WL DIMINISH THIS EVNG WITH LOSS OF DAYTIME HEATING/MIXING. VFR CONDITIONS WL CONTINUE TNGT WITH INFLUX OF DRIER NEAR SFC AIR EVEN IF THERE ARE SOME LINGERING CLDS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 340 AM EDT MON JUL 20 2015 LOW PRESSURE FROM W ONTARIO TO JUST NW OF JAMES BAY WILL SWING INTO S HUDSON BAY AND W QUEBEC TODAY WHILE DRAGGING A TROUGH ACROSS LAKE SUPERIOR. WITH THE TIGHT PRESSURE GRADIENT...25KT WINDS WILL REMAIN POSSIBLE ACROSS LAKE SUPERIOR. A LARGE AREA OF HIGH PRESSURE FROM S CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES TONIGHT WILL SLOWLY EDGE E...AND BUILD ACROSS THE UPPER GREAT LAKES THROUGH THURSDAY...WITH WINDS RETURNING TO AROUND 20KTS OR LESS. VERY PATCHY FOG /MAINLY N/ WILL ALSO DIMINISH MONDAY. EXPECT A N PLAINS LOW THURSDAY NIGHT TO SHIFT TO N ONTARIO BY THE END OF THE DAY FRIDAY...WITH A TROUGH PUSHING ACROSS MINNESOTA AND W LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...KC MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
358 AM EDT MON JUL 20 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM EDT MON JUL 20 2015 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALOFT ALONG THE CNDN BORDER E OF AN UPR RDG OVER THE ROCKIES. SHRTWV AND ASSOCIATED SFC LO EMBEDDED IN THIS FLOW ARE MOVING THRU NW ONTARIO...WITH ATTENDANT SFC COLD FNT STRETCHING INTO MN. SOME ISOLD SHOWERS ARE PRESENT JUST AHEAD OF THIS FNT AND MOVING THRU NW LK SUP TOWARD THE KEWEENAW. BUT WITH AN ABSENCE OF MSTR INFLOW INTO THE SHRTWV AND NOCTURNAL COOLING...THESE SHOWERS HAVE TENDED TO DIMINISH WITH TIME TO THE S OF SHARPER DPVA/DEEP LYR QVECTOR CNVGC PASSING TO THE N CLOSER TO THE SHRTWV TRACK. OTRW...STEADY WSW WINDS AHEAD OF THE FNT ARE RESULTING IN WELL ABV NORMAL TEMPS EARLY THIS MRNG. MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON POPS TODAY ASSOCIATED WITH APRCHG COLD FNT AS WELL AS GUSTY WINDS. TODAY...SHRTWV MOVING THRU NW ONTARIO JUST N OF LK SUP IS FCST TO MOVE QUICKLY ESEWD TO NEAR THE QUEBEC/ONTARIO BORDER BY 00Z THIS EVNG. ATTENDANT COLD FNT IS PROGGED TO SWING THRU THE CWA...REACHING THE SE ZNS ARND 18Z BEFORE CONTINUING AWAY TO THE SE IN THE AFTN. WHILE THERE MAY BE SOME ISOLATED SHOWERS THIS MRNG OVER MAINLY THE NRN TIER CLOSER TO THE SHRTWV TRACK/CORE OF SHARPER FORCING...EXPECT A MAINLY DRY FROPA BECAUSE THE TIMING WL BE AHEAD OF THE FULL IMPACT OF DAYTIME HEATING. A BIT CONCERNED THE LATER ARRIVAL EARLY THIS AFTN OVER THE SE CWA WITH SOME ENHANCED LLVL CNVGC WITH LK BREEZE OFF LK MI COULD RESULT IN SOME ISOLD SHOWERS/TS THERE AS HINTED AT BY SOME OF THE HIER RES MODELS...SO DID MENTION SOME SCHC POPS IN THIS AREA BEFORE MORE VIGOROUS DRYING AND THE ARRIVAL OF LARGER SCALE DNVA/DEEP LYR QVECTOR DVGC ENDS THE PCPN CHCS BY LATE AFTN. EXPECT SOME GUSTY WINDS AGAIN TODAY AHEAD OF AND FOLLOWING THE COLD FROPA WITH H925 WSW WINDS UP TO 25-30 KTS SHIFTING TO THE WNW IN THE AFTN. EXPECT THE HIEST MAX TEMPS INTO THE 80S OVER THE SCNTRAL. COOL AIR ADVECTION IN THE WAKE OF THE FROPA WITH H85 TEMPS PROGGED TO FALL TO NEAR 10C OVER THE NW CWA BY 00Z WL LIMIT THE DAYTIME DIURNAL TEMP RISE TO THE NW. TNGT...ANOTHER SHRTWV/SOME MID LVL MSTR ARE FCST TO SWING SE INTO THE UPR LKS WITHIN DEEPENING UPR TROF. WHILE THERE MAY BE SOME CLDS ACCOMPANYING THIS DISTURBANCE...NONE OF THE MODELS SHOW ANY PCPN OVER UPR MI. WL MAINTAIN A DRY FCST DURING PERIOD OF NOCTURNAL COOLING. OVERNGT LOWS WL BE QUITE A BIT LOWER THAN THIS MRNG WITH SOME UPR 40S AT SOME OF THE COOL SPOTS. BUT STEADY NW WINDS WL TEND TO LIMIT THE TEMP DROP. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 340 AM EDT MON JUL 20 2015 IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE. POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION LATE FRI INTO EARLY SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT. MAY SEE A LIGHT SHOWER OR TWO ON TUE AFTERNOON AS A SHORTWAVE MAY PASS THROUGH...BUT WILL LEAVE THE FORECAST DRY FOR NOW GIVEN LIMITED COVERAGE/PRECIP AMOUNT/CONFIDENCE. MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER LATE WED INTO THU NIGHT AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE SW ALONG WITH MOISTURE ADVECTION. WILL KEEP POPS SW OF THE CWA ON WED...BUT WILL CONTINUE TO BRING SLIGHT CHANCE POPS INTO AREAS ALONG THE WI BORDER WED NIGHT AND THU AS THE FRONT SLOWLY MOVES NE. TIMING/LOCATION MAY BE CHANGED IF ANY DISTURBANCES FORM THAT CAUSE THE FRONT/MOISTURE ADVECTION TO SURGE FARTHER N. THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES BETWEEN MODELS WITH THIS SYSTEM...WITH THE GFS BEING STRONGER AND CONSIDERABLY FARTHER S THAN THE ECMWF. WILL USE CONSENSUS GUIDANCE GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH SAT. SUN LOOKS DRY FOR NOW. TEMPS WILL BE COOLEST TUE AND WED WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPS EXPECTED. AN UPPER RIDGE MOVES OVER THE AREA LATE IN THE WEEK AHEAD OF THE CANADIAN DISTURBANCE...LEADING TO NEAR NORMAL TEMPS THU AND ABOVE NORMAL TEMPS FRI THROUGH SUN. LOOKS LIKE UPPER RIDGING W OF THE REGION IS FOR THE MOST PART HERE TO STAY THROUGH THE END OF JULY...WITH ABOVE NORMAL TEMPS. CFS ALSO POINTS TO ABOVE NORMAL TEMPS THROUGH MOST OF THE REST OF THE MONTH...WITH BELOW NORMAL TEMPS TO START AUGUST OFF. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 122 AM EDT MON JUL 20 2015 VFR CEILINGS AND VIS WILL PREVAIL THROUGH THE PERIOD. LLWS IS EXPECTED AT KIWD AND KSAW OVERNIGHT AS A LOW-LEVEL WIND MAX MOVES OVER THE AREA. WINDS WILL INCREASE AGAIN AT THE SURFACE LATER TONIGHT AT KCMX AND ACROSS ALL OF THE TAF SITES ON MONDAY IN THE WAKE OF A MAINLY DRY COLD FRONTAL PASSAGE. STRONGEST WINDS WILL BE AT KCMX WHERE WIND GUSTS WILL BE OVER 30 KTS FROM LATE MORNING INTO MID AFTERNOON ON MONDAY. WINDS WILL DIMINISH MONDAY EVENING WITH LOSS OF DIURNAL MIXING. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 340 AM EDT MON JUL 20 2015 LOW PRESSURE FROM W ONTARIO TO JUST NW OF JAMES BAY WILL SWING INTO S HUDSON BAY AND W QUEBEC TODAY WHILE DRAGGING A TROUGH ACROSS LAKE SUPERIOR. WITH THE TIGHT PRESSURE GRADIENT...25KT WINDS WILL REMAIN POSSIBLE ACROSS LAKE SUPERIOR. A LARGE AREA OF HIGH PRESSURE FROM S CENTRAL CANADA THROUGH THE CENTRAL PLAINS STATES TONIGHT WILL SLOWLY EDGE E...AND BUILD ACROSS THE UPPER GREAT LAKES THROUGH THURSDAY...WITH WINDS RETURNING TO AROUND 20KTS OR LESS. VERY PATCHY FOG /MAINLY N/ WILL ALSO DIMINISH MONDAY. EXPECT A N PLAINS LOW THURSDAY NIGHT TO SHIFT TO N ONTARIO BY THE END OF THE DAY FRIDAY...WITH A TROUGH PUSHING ACROSS MINNESOTA AND W LAKE SUPERIOR. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...KC LONG TERM...TITUS AVIATION...VOSS MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1231 AM CDT MON JUL 20 2015 .UPDATE... ISSUED AT 955 PM CDT SUN JUL 19 2015 SHOWERS ARE DEVELOPING ALONG AND JUST AHEAD OF THE COLD FRONT THAT HAS REACHED KOOCHICHING AND NORTHERN ST. LOUIS COUNTIES ATTM. LATEST HRRR HAS SHOWERS CONTINUING TO ACCOMPANY THE FRONT AS IT PROGRESSES THROUGH THE AREA TONIGHT. HAVE BUMPED UP THE POPS OR ADDED POPS TO ACCOUNT FOR THIS TREND. UPDATE ISSUED AT 736 PM CDT SUN JUL 19 2015 A FEW SHOWERS ARE MOVING THROUGH THE BWCAW AHEAD OF A COLD FRONT. SOME ISOLD THUNDERSTORMS ARE JUST N OF THE CANADIAN BORDER AND MAY CLIP NORTH CENTRAL INTO NE MN THIS EVENING. INSTABILITY APPEARS TO DECREASE CONSIDERABLY AFTER 03Z AND JUST HAVE A MENTION OF SHOWERS. MADE OTHER MINOR TWEAKS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 324 PM CDT SUN JUL 19 2015 THE FOCUS FOR TONIGHT AND MONDAY WILL BE A COLD FRONT THAT WILL DROP SOUTHWARD ACROSS THE NORTHLAND. AN AREA OF SHOWERS WAS CURRENTLY MOVING TOWARD LAKE OF THE WOODS OR A BIT NORTH OF THERE. THE SHOWERS WERE DROPPING TO THE EAST SOUTHEAST AND MAY BRUSH PORTIONS OF THE INTERNATIONAL BORDER REGION DURING THE EVENING. SOME MARGINAL INSTABILITY HAD DEVELOPED ACROSS SOUTH CENTRAL CANADA AND THE BORDER REGION. AS A RESULT...WE COULD SEE SOME LIMITED SHOWERS AND THUNDERSTORMS OVERNIGHT...MAINLY ACROSS THE NORTH AND NORTHEAST. COOLER AIR WILL INFILTRATE THE REGION LATER TONIGHT AND MONDAY...ALTHOUGH TEMPERATURES WILL NOT BE TOO MUCH COOLER BEHIND THIS FRONT. WILL ALSO CARRY A SMALL POP IN THE FAR NORTH AND NORTHEAST INTO MONDAY. GUSTY NORTH TO NORTHWEST WINDS ARE EXPECTED TO DEVELOP ON MONDAY...AS HIGH PRESSURE PUSHES INTO THE DAKOTAS BEHIND THE FRONT. TEMPERATURES WILL LARGELY BE IN THE 70S WITH SOME LOWER 80S IN THE SOUTH/SOUTHEAST. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 324 PM CDT SUN JUL 19 2015 TUESDAY...HIGH PRESSURE WILL MOVE INTO THE UPPER MIDWEST...PROVIDING THE NORTHLAND WITH CLEAR SKIES. HIGHS SHOULD RANGE BETWEEN THE MIDDLE 70S TO NEAR 80 DEGREES. WEDNESDAY AND WEDNESDAY NIGHT...AN UPPER LEVEL RIDGE IN THE NORTHERN PLAINS WILL BEGIN TO SHIFT INTO THE UPPER MIDWEST...MEANING A WARMER DAY FOR THE NORTHLAND. A WARM FRONT MIGHT SET UP NEAR THE SOUTHERN AND WESTERN FORECAST AREA...AND COULD HELP DEVELOP SHOWERS AND THUNDERSTORMS. THE GEM AND GFS ARE THE MOST AGGRESSIVE WITH PCPN WITH THE WARM FRONT. HIGHS SHOULD RANGE FROM THE UPPER 70S TO LOW 80S. THURSDAY...THE UPPER LEVEL RIDGE WILL SHIFT INTO THE UPPER MIDWEST. THERE ARE LOW CHANCES OF SHOWERS AND STORMS OVER THE NORTHERN AND SE FORECAST AREA. FRIDAY...THE GFS/ECMWF/GEM ARE IN FAIRLY GOOD AGREEMENT THAT A TROUGH WILL MOVE THROUGH THE NORTHLAND AND BRING SHOWERS AND THUNDERSTORMS. INCREASED PCPN CHANCES BASED ON THE MODEL AGREEMENT. SATURDAY...HIGH PRESSURE WILL LIKELY MOVE INTO THE PLAINS OR UPPER MIDWEST IN THE WAKE OF THE TROUGH PASSAGE ON FRIDAY. SATURDAY WILL LIKELY BE DRY...BUT THERE ARE LOW PCPN CHANCES IN THE FORECAST TO ACCOUNT FOR THE POTENTIAL THAT THE TROUGH PASSAGE SLOWS DOWN IN SUBSEQUENT MODEL RUNS. HIGHS WILL LIKELY BE IN THE LOW 80S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1231 AM CDT MON JUL 20 2015 A COLD FRONT WILL PASS THROUGH DLH/BRD/HYR BY 09Z AND BE ACCOMPANIED BY SHOWERS. EXACT TIMING IS DIFFICULT AND HAVE USED A VCSH MENTION. WITH FROPA...WINDS TURN TO THE WEST OR NORTHWEST. AFTER 12Z...GUSTY NW WINDS WILL AFFECT ALL TERMINALS. VFR IS FORECAST. && .PRELIMINARY POINT TEMPS/POPS... DLH 57 78 56 79 / 0 0 0 10 INL 51 75 49 79 / 0 0 0 0 BRD 54 81 57 83 / 0 0 20 20 HYR 53 77 53 79 / 0 0 0 20 ASX 57 78 54 78 / 0 0 0 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. LS...NONE. && $$ UPDATE...GSF SHORT TERM...DAP LONG TERM...GROCHOCINSKI AVIATION...GSF
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1242 PM CDT MON JUL 20 2015 .UPDATE: ISSUED AT 1235 PM CDT MON JUL 20 2015 LET FLASH FLOOD WATCH EXPIRE AT NOON AS MAIN AREA OF RAIN HAS MOVED OFF TO THE EAST AND DIMINISHED. COULD SEE REDEVELOPMENT THIS AFTERNOON AHEAD OF COLD FRONT AS MCV MOVES THROUGH. OTHERWISE, PARTLY TO MOSTLY CLOUDY SKIES WITH HIGHS IN THE MID 80S TO MID 90S. FAR SOUTHERN PORTIONS OF FORECAST AREA COULD SEE HEAT INDICES BETWEEN 100 AND 105. BYRD && .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 316 AM CDT MON JUL 20 2015 CONVECTION TRENDS ARE THE PRIMARY FOCUS FOR TODAY`S FORECAST. LATEST SHORT RANGE GUIDANCE INCLUDING THE RAP, NAM, AND TO A LESSER EXTENT THE HRRR SHOW THE LINE OF BACKBUILDING THUNDERSTORMS CURRENTLY OVER SOUTH-CENTRAL MISSOURI CONTINUING AND SLOWLY MOVING EAST-NORTHEAST THROUGH THE EARLY AND MID MORNING HOURS. THE RAP SEEMS TO BE HANDLING THIS BEST WITH MASS FIELDS PICKING UP THE CONVECTION PRETTY WELL AT THIS TIME. NOT SURE HOW FAR EAST- NORTHEAST THE STORMS WILL GET THIS MORNING...BUT HEAVY RAIN OVER OUR EASTERN OZARK COUNTIES LOOKS LIKELY SO HAVE EXPANDED THE FLASH FLOOD WATCH ACCORDINGLY. THE AREA OF STORMS NOW MOVING INTO WEST CENTRAL/NORTHWEST MISSOURI WILL FURTHER COMPLICATE THE FORECAST. SHOULD SEE THAT AREA GRADUALLY DIMINISH THIS MORNING AS THE LOW LEVEL JET WEAKENS, BUT I DON`T THINK IT WILL TOTALLY FALL APART. SHOULD SEE REDEVELOPMENT IN THE VICINITY OF THE MCV THIS AFTERNOON AS DIURNAL HEATING REINVIGORATES CONVECTION. COVERAGE IS UNCERTAIN AT THIS TIME, BUT THINK AT LEAST 40-50 POPS ARE WARRANTED THIS AFTERNOON. SECOND CONCERN IS POTENTIAL FOR HEAT INDEX VALUES IN EXCESS OF 100 DEGREES AGAIN TODAY. THIS SEEMS LESS LIKELY THAN PREVIOUS DAYS DUE TO EXTENSIVE CLOUD COVER FROM CONVECTIVE DEBRIS AND AFTERNOON THUNDERSTORMS. THOUGH FORECAST HEAT INDEX VALUES COME VERY NEAR 100 DEGREES (AND I CANNOT RULE OUT THERE WON`T BE SOME 100+ DEGREE READINGS IN A FEW PLACES THIS AFTERNOON), FEEL THERE ARE TOO MANY FACTORS AGAINST WIDESPREAD 100+ HEAT INDEX VALUES TO ISSUE ANY HEADLINES AT THIS TIME. CARNEY .LONG TERM: (TONIGHT THROUGH SUNDAY) ISSUED AT 333 AM CDT MON JUL 20 2015 AT THE START OF THE PERIOD TONIGHT, IT LOOKS LIKE THE HIGHEST PROBS FOR RAIN WILL BE FOR AREAS NEAR I-70 AND INTO SOUTHEAST MO WITH WHAT SHOULD BE MUCH MORE DIURNALLY DEPENDENT SCATTERED CONVECTION FURTHER TO THE NORTH. ANOTHER COLD FRONT WILL MOVE THRU OUR REGION THIS EVENING AND WILL, OVER TIME, SUPPRESS THE MORE WIDESPREAD SHRA/TSRA OVER OUR SOUTHERN FORECAST AREA TO THE SOUTH WHILE THE NORTHERN SCATTERED CONVECTION WILL LIKELY DISSIPATE. HIGH PRESSURE WILL THEN BE THE DOMINANT INFLUENCE OVER MOST OF OUR REGION TUESDAY MORNING THRU WEDNESDAY AFTERNOON. ENOUGH DRY AIR IS EXPECTED TO BUILD IN MOST AREAS TO RESULT IN DRY WX WITH NIGHTTIME MIN TEMPS POSSIBLY CLIPPING THE 50S NORTH OF I-70 WITH LOW 60S EXPECTED MOST ELSEWHERE. MAX TEMPS ARE EXPECTED TO BE A RELATIVELY BENIGN LOW-MID 80S. UPPER LEVEL DISTURBANCES ARE ANTICIPATED TO HAVE JUST ENOUGH MOISTURE TO WORK WITH AS THEY TRAVERSE ACROSS FAR SOUTHERN MO AND SOUTHERN IL TO RESULT IN CONTINUED CHANCES FOR RAIN THIS PERIOD. THE OLD FRONT TO THE SOUTH IS EXPECTED TO PUSH BACK TO THE NORTH WEDNESDAY NIGHT FOR INCREASING RAIN CHANCES AREAWIDE. AT THIS POINT...THERE IS GOOD MODEL CONSENSUS ON AMPLIFICATION UPSTREAM TO THE ALREADY EXISTING MID AND UPPER LEVEL NW FLOW THAT IT LOOKS LIKE WHERE THE FRONT WINDS UP EARLY THURSDAY MAY BE WHERE IT STAYS FOR THE REMAINDER OF THE WEEK...RESULTING IN PERSISTENT RAIN CHANCES FOR LATE WEEK. THE OTHER SOLUTION...WHICH WAS FAVORED UNTIL RECENTLY...WAS THE FRONT PUSHING NORTH BRIEFLY AS A WARM FRONT...BUT THE MODELS HAVE BEEN GRADUALLY BACKING AWAY FROM THIS SCENARIO OVER THE PAST FEW DAYS. THE AMPLIFIED UPPER LEVEL HIGH TO OUR WEST IS THEN EXPECTED TO PERSIST THRU THE UPCOMING WEEKEND...AND WHILE TEMPS SHOULD BOUNCE BACK...THEIR LIKELIHOOD OF GETTING MUCH ABOVE AVERAGE IS LOOKING SLIMMER BY THE DAY. TES && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1235 PM CDT MON JUL 20 2015 MAIN RAIN SHIELD HAS EXITED TAF SITES, SO KEPT TAFS DRY FOR NOW. DID KEEP VICINITY THUNDERSTORMS AT KUIN AND KCOU AS FRONT MOVES THROUGH LATER THIS AFTERNOON. OTHERWISE, VFR CONDITIONS WITH SOUTH WINDS VEERING TO THE WEST THEN NORTH THROUGH THE FORECAST PERIOD. SPECIFICS FOR KSTL: MAIN RAIN SHIELD HAS EXITED METRO AREA, SO KEPT TAF DRY FOR NOW. MAY NEED TO ADD VICINITY THUNDERSTORMS MENTION AS FRONT MOVES THROUGH THIS EVENING. OTHERWISE, VFR CONDITIONS WITH SOUTH WINDS VEERING TO THE WEST BY 00Z TUESDAY THEN NORTH BY 13Z TUESDAY. BYRD && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
645 AM CDT MON JUL 20 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 316 AM CDT MON JUL 20 2015 CONVECTION TRENDS ARE THE PRIMARY FOCUS FOR TODAY`S FORECAST. LATEST SHORT RANGE GUIDANCE INCLUDING THE RAP, NAM, AND TO A LESSER EXTENT THE HRRR SHOW THE LINE OF BACKBUILDING THUNDERSTORMS CURRENTLY OVER SOUTH-CENTRAL MISSOURI CONTINUING AND SLOWLY MOVING EAST-NORTHEAST THROUGH THE EARLY AND MID MORNING HOURS. THE RAP SEEMS TO BE HANDLING THIS BEST WITH MASS FIELDS PICKING UP THE CONVECTION PRETTY WELL AT THIS TIME. NOT SURE HOW FAR EAST- NORTHEAST THE STORMS WILL GET THIS MORNING...BUT HEAVY RAIN OVER OUR EASTERN OZARK COUNTIES LOOKS LIKELY SO HAVE EXPANDED THE FLASH FLOOD WATCH ACCORDINGLY. THE AREA OF STORMS NOW MOVING INTO WEST CENTRAL/NORTHWEST MISSOURI WILL FURTHER COMPLICATE THE FORECAST. SHOULD SEE THAT AREA GRADUALLY DIMINISH THIS MORNING AS THE LOW LEVEL JET WEAKENS, BUT I DON`T THINK IT WILL TOTALLY FALL APART. SHOULD SEE REDEVELOPMENT IN THE VICINITY OF THE MCV THIS AFTERNOON AS DIURNAL HEATING REINVIGORATES CONVECTION. COVERAGE IS UNCERTAIN AT THIS TIME, BUT THINK AT LEAST 40-50 POPS ARE WARRANTED THIS AFTERNOON. SECOND CONCERN IS POTENTIAL FOR HEAT INDEX VALUES IN EXCESS OF 100 DEGREES AGAIN TODAY. THIS SEEMS LESS LIKELY THAN PREVIOUS DAYS DUE TO EXTENSIVE CLOUD COVER FROM CONVECTIVE DEBRIS AND AFTERNOON THUNDERSTORMS. THOUGH FORECAST HEAT INDEX VALUES COME VERY NEAR 100 DEGREES (AND I CANNOT RULE OUT THERE WON`T BE SOME 100+ DEGREE READINGS IN A FEW PLACES THIS AFTERNOON), FEEL THERE ARE TOO MANY FACTORS AGAINST WIDESPREAD 100+ HEAT INDEX VALUES TO ISSUE ANY HEADLINES AT THIS TIME. CARNEY .LONG TERM: (TONIGHT THROUGH SUNDAY) ISSUED AT 333 AM CDT MON JUL 20 2015 AT THE START OF THE PERIOD TONIGHT, IT LOOKS LIKE THE HIGHEST PROBS FOR RAIN WILL BE FOR AREAS NEAR I-70 AND INTO SOUTHEAST MO WITH WHAT SHOULD BE MUCH MORE DIURNALLY DEPENDENT SCATTERED CONVECTION FURTHER TO THE NORTH. ANOTHER COLD FRONT WILL MOVE THRU OUR REGION THIS EVENING AND WILL, OVER TIME, SUPPRESS THE MORE WIDESPREAD SHRA/TSRA OVER OUR SOUTHERN FORECAST AREA TO THE SOUTH WHILE THE NORTHERN SCATTERED CONVECTION WILL LIKELY DISSIPATE. HIGH PRESSURE WILL THEN BE THE DOMINANT INFLUENCE OVER MOST OF OUR REGION TUESDAY MORNING THRU WEDNESDAY AFTERNOON. ENOUGH DRY AIR IS EXPECTED TO BUILD IN MOST AREAS TO RESULT IN DRY WX WITH NIGHTTIME MIN TEMPS POSSIBLY CLIPPING THE 50S NORTH OF I-70 WITH LOW 60S EXPECTED MOST ELSEWHERE. MAX TEMPS ARE EXPECTED TO BE A RELATIVELY BENIGN LOW-MID 80S. UPPER LEVEL DISTURBANCES ARE ANTICIPATED TO HAVE JUST ENOUGH MOISTURE TO WORK WITH AS THEY TRAVERSE ACROSS FAR SOUTHERN MO AND SOUTHERN IL TO RESULT IN CONTINUED CHANCES FOR RAIN THIS PERIOD. THE OLD FRONT TO THE SOUTH IS EXPECTED TO PUSH BACK TO THE NORTH WEDNESDAY NIGHT FOR INCREASING RAIN CHANCES AREAWIDE. AT THIS POINT...THERE IS GOOD MODEL CONSENSUS ON AMPLIFICATION UPSTREAM TO THE ALREADY EXISTING MID AND UPPER LEVEL NW FLOW THAT IT LOOKS LIKE WHERE THE FRONT WINDS UP EARLY THURSDAY MAY BE WHERE IT STAYS FOR THE REMAINDER OF THE WEEK...RESULTING IN PERSISTENT RAIN CHANCES FOR LATE WEEK. THE OTHER SOLUTION...WHICH WAS FAVORED UNTIL RECENTLY...WAS THE FRONT PUSHING NORTH BRIEFLY AS A WARM FRONT...BUT THE MODELS HAVE BEEN GRADUALLY BACKING AWAY FROM THIS SCENARIO OVER THE PAST FEW DAYS. THE AMPLIFIED UPPER LEVEL HIGH TO OUR WEST IS THEN EXPECTED TO PERSIST THRU THE UPCOMING WEEKEND...AND WHILE TEMPS SHOULD BOUNCE BACK...THEIR LIKELIHOOD OF GETTING MUCH ABOVE AVERAGE IS LOOKING SLIMMER BY THE DAY. TES && .AVIATION: (FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 636 AM CDT MON JUL 20 2015 AREAS OF IFR STRATUS AND FOG WILL RISE TO MVFR AND VFR. EXPECT THE AREA OF RAIN AND THUNDERSTORMS TO WEAKEN THIS MORNING, BUT REDEVELOP THIS AFTERNOON. INTENSITY AND AREAL COVERAGE IN STORMS IS UNCERTAIN AT THIS TIME, WHICH IS WHY I DIDN`T HIT THE THUNDERSTORMS HARDER IN THE TERMINAL FORECASTS. STORMS SHOULD PERSIST INTO EARLY EVENING, BUT INDICATIONS ARE THAT THEY SHOULD BE WEAKENING AFTER 02Z. COULD BE SOME FOG OVERNIGHT TONIGHT, BUT DID NOT PUT MENTION INTO TAFS DUE TO THE UNCERTAINTIES IN THE FORECAST. SPECIFICS FOR KSTL: SHORT RANGE GUIDANCE IS INDICATING THAT THE STORMS OVER CENTRAL MISSOURI WILL WEAKEN AS THEY CONTINUE MOVING EAST. THINK THERE MAY BE SOME LIGHT RAIN REMAINING AS IT MOVES INTO THE STL AREA AFTER 16Z...BUT I AM NOT CERTAIN OF THIS. EXPECT SCATTERED THUNDERSTORMS TO REDEVELOP THIS AFTERNOON AND PERSIST INTO THE EARLY EVENING...WEAKENING/MOVING OUT OF THE AREA BY 02Z. CARNEY && .LSX WATCHES/WARNINGS/ADVISORIES: MO...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR AUDRAIN MO-BOONE MO- CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO- IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO- MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO- WASHINGTON MO. IL...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR ADAMS IL-BOND IL- BROWN IL-CALHOUN IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-MONTGOMERY IL-PIKE IL-ST. CLAIR IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
333 AM CDT MON JUL 20 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 316 AM CDT MON JUL 20 2015 CONVECTION TRENDS ARE THE PRIMARY FOCUS FOR TODAY`S FORECAST. LATEST SHORT RANGE GUIDANCE INCLUDING THE RAP, NAM, AND TO A LESSER EXTENT THE HRRR SHOW THE LINE OF BACKBUILDING THUNDERSTORMS CURRENTLY OVER SOUTH-CENTRAL MISSOURI CONTINUING AND SLOWLY MOVING EAST-NORTHEAST THROUGH THE EARLY AND MID MORNING HOURS. THE RAP SEEMS TO BE HANDLING THIS BEST WITH MASS FIELDS PICKING UP THE CONVECTION PRETTY WELL AT THIS TIME. NOT SURE HOW FAR EAST- NORTHEAST THE STORMS WILL GET THIS MORNING...BUT HEAVY RAIN OVER OUR EASTERN OZARK COUNTIES LOOKS LIKELY SO HAVE EXPANDED THE FLASH FLOOD WATCH ACCORDINGLY. THE AREA OF STORMS NOW MOVING INTO WEST CENTRAL/NORTHWEST MISSOURI WILL FURTHER COMPLICATE THE FORECAST. SHOULD SEE THAT AREA GRADUALLY DIMINISH THIS MORNING AS THE LOW LEVEL JET WEAKENS, BUT I DON`T THINK IT WILL TOTALLY FALL APART. SHOULD SEE REDEVELOPMENT IN THE VICINITY OF THE MCV THIS AFTERNOON AS DIURNAL HEATING REINVIGORATES CONVECTION. COVERAGE IS UNCERTAIN AT THIS TIME, BUT THINK AT LEAST 40-50 POPS ARE WARRANTED THIS AFTERNOON. SECOND CONCERN IS POTENTIAL FOR HEAT INDEX VALUES IN EXCESS OF 100 DEGREES AGAIN TODAY. THIS SEEMS LESS LIKELY THAN PREVIOUS DAYS DUE TO EXTENSIVE CLOUD COVER FROM CONVECTIVE DEBRIS AND AFTERNOON THUNDERSTORMS. THOUGH FORECAST HEAT INDEX VALUES COME VERY NEAR 100 DEGREES (AND I CANNOT RULE OUT THERE WON`T BE SOME 100+ DEGREE READINGS IN A FEW PLACES THIS AFTERNOON), FEEL THERE ARE TOO MANY FACTORS AGAINST WIDESPREAD 100+ HEAT INDEX VALUES TO ISSUE ANY HEADLINES AT THIS TIME. CARNEY .LONG TERM: (TONIGHT THROUGH SUNDAY) ISSUED AT 333 AM CDT MON JUL 20 2015 AT THE START OF THE PERIOD TONIGHT, IT LOOKS LIKE THE HIGHEST PROBS FOR RAIN WILL BE FOR AREAS NEAR I-70 AND INTO SOUTHEAST MO WITH WHAT SHOULD BE MUCH MORE DIURNALLY DEPENDENT SCATTERED CONVECTION FURTHER TO THE NORTH. ANOTHER COLD FRONT WILL MOVE THRU OUR REGION THIS EVENING AND WILL, OVER TIME, SUPPRESS THE MORE WIDESPREAD SHRA/TSRA OVER OUR SOUTHERN FORECAST AREA TO THE SOUTH WHILE THE NORTHERN SCATTERED CONVECTION WILL LIKELY DISSIPATE. HIGH PRESSURE WILL THEN BE THE DOMINANT INFLUENCE OVER MOST OF OUR REGION TUESDAY MORNING THRU WEDNESDAY AFTERNOON. ENOUGH DRY AIR IS EXPECTED TO BUILD IN MOST AREAS TO RESULT IN DRY WX WITH NIGHTTIME MIN TEMPS POSSIBLY CLIPPING THE 50S NORTH OF I-70 WITH LOW 60S EXPECTED MOST ELSEWHERE. MAX TEMPS ARE EXPECTED TO BE A RELATIVELY BENIGN LOW-MID 80S. UPPER LEVEL DISTURBANCES ARE ANTICIPATED TO HAVE JUST ENOUGH MOISTURE TO WORK WITH AS THEY TRAVERSE ACROSS FAR SOUTHERN MO AND SOUTHERN IL TO RESULT IN CONTINUED CHANCES FOR RAIN THIS PERIOD. THE OLD FRONT TO THE SOUTH IS EXPECTED TO PUSH BACK TO THE NORTH WEDNESDAY NIGHT FOR INCREASING RAIN CHANCES AREAWIDE. AT THIS POINT...THERE IS GOOD MODEL CONSENSUS ON AMPLIFICATION UPSTREAM TO THE ALREADY EXISTING MID AND UPPER LEVEL NW FLOW THAT IT LOOKS LIKE WHERE THE FRONT WINDS UP EARLY THURSDAY MAY BE WHERE IT STAYS FOR THE REMAINDER OF THE WEEK...RESULTING IN PERSISTENT RAIN CHANCES FOR LATE WEEK. THE OTHER SOLUTION...WHICH WAS FAVORED UNTIL RECENTLY...WAS THE FRONT PUSHING NORTH BRIEFLY AS A WARM FRONT...BUT THE MODELS HAVE BEEN GRADUALLY BACKING AWAY FROM THIS SCENARIO OVER THE PAST FEW DAYS. THE AMPLIFIED UPPER LEVEL HIGH TO OUR WEST IS THEN EXPECTED TO PERSIST THRU THE UPCOMING WEEKEND...AND WHILE TEMPS SHOULD BOUNCE BACK...THEIR LIKELIHOOD OF GETTING MUCH ABOVE AVERAGE IS LOOKING SLIMMER BY THE DAY. TES && .AVIATION: (FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 639 PM CDT SUN JUL 19 2015 OUTFLOW BNDY CURRENTLY STRETCHES FROM KC REGION TO JUST S OF KJEF TO KFAM AREA. BELIEVE THIS WILL BE THE FOCUS FOR TSRA THIS EVE. EXPECT A TSRA COMPLEX TO DEVELOP ACROSS ERN KS OR WRN MO OVERNIGHT AND MOVE EWD IMPACTING TERMINALS DURING THE PRE-DAWN AND INTO MID MORNING HOURS. A BRIEF LULL MAY OCCUR DURING THE LATE MORNING HOURS FOR SUS/CPS AND PERHAPS COU BEFORE ANOTHER ROUND BEING POSSIBLE DURING THE AFTERNOON HRS. HOWEVER, THIS WILL GREATLY DEPEND ON TIMING OF MORNING CONVECTION AND EXACT PLACEMENT...WHICH MAY INSTEAD BE A MORE PROLONGED PERIOD OF STORMS BEFORE PUSHING S OF THE TERMINALS. UIN CURRENTLY HAS THE BEST CHANCE FOR DEVELOPING FG OVERNIGHT AND GOING FCST MAY NOT HAVE VSBYS LOW ENUF. OTHERWISE, EXPECT VFR CONDITIONS OUTSIDE OF TSRA. SPECIFICS FOR KSTL: EXPECT TSRA TO IMPACT TERMINAL AROUND SUNRISE MONDAY WITH A LULL IN THE LATE MORNING INTO AFTERNOON BEFORE ANOTHER ROUND POSSIBLE IN THE LATE AFTERNOON INTO EVE. && .LSX WATCHES/WARNINGS/ADVISORIES: MO...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR AUDRAIN MO-BOONE MO- CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO- IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO- MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO- WASHINGTON MO. IL...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR ADAMS IL-BOND IL- BROWN IL-CALHOUN IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-MONTGOMERY IL-PIKE IL-ST. CLAIR IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
331 AM CDT MON JUL 20 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 316 AM CDT MON JUL 20 2015 CONVECTION TRENDS ARE THE PRIMARY FOCUS FOR TODAY`S FORECAST. LATEST SHORT RANGE GUIDANCE INCLUDING THE RAP, NAM, AND TO A LESSER EXTENT THE HRRR SHOW THE LINE OF BACKBUILDING THUNDERSTORMS CURRENTLY OVER SOUTH-CENTRAL MISSOURI CONTINUING AND SLOWLY MOVING EAST-NORTHEAST THROUGH THE EARLY AND MID MORNING HOURS. THE RAP SEEMS TO BE HANDLING THIS BEST WITH MASS FIELDS PICKING UP THE CONVECTION PRETTY WELL AT THIS TIME. NOT SURE HOW FAR EAST- NORTHEAST THE STORMS WILL GET THIS MORNING...BUT HEAVY RAIN OVER OUR EASTERN OZARK COUNTIES LOOKS LIKELY SO HAVE EXPANDED THE FLASH FLOOD WATCH ACCORDINGLY. THE AREA OF STORMS NOW MOVING INTO WEST CENTRAL/NORTHWEST MISSOURI WILL FURTHER COMPLICATE THE FORECAST. SHOULD SEE THAT AREA GRADUALLY DIMINISH THIS MORNING AS THE LOW LEVEL JET WEAKENS, BUT I DON`T THINK IT WILL TOTALLY FALL APART. SHOULD SEE REDEVELOPMENT IN THE VICINITY OF THE MCV THIS AFTERNOON AS DIURNAL HEATING REINVIGORATES CONVECTION. COVERAGE IS UNCERTAIN AT THIS TIME, BUT THINK AT LEAST 40-50 POPS ARE WARRANTED THIS AFTERNOON. SECOND CONCERN IS POTENTIAL FOR HEAT INDEX VALUES IN EXCESS OF 100 DEGREES AGAIN TODAY. THIS SEEMS LESS LIKELY THAN PREVIOUS DAYS DUE TO EXTENSIVE CLOUD COVER FROM CONVECTIVE DEBRIS AND AFTERNOON THUNDERSTORMS. THOUGH FORECAST HEAT INDEX VALUES COME VERY NEAR 100 DEGREES (AND I CANNOT RULE OUT THERE WON`T BE SOME 100+ DEGREE READINGS IN A FEW PLACES THIS AFTERNOON), FEEL THERE ARE TOO MANY FACTORS AGAINST WIDESPREAD 100+ HEAT INDEX VALUES TO ISSUE ANY HEADLINES AT THIS TIME. CARNEY .LONG TERM: (MONDAY THROUGH NEXT SUNDAY) ISSUED AT 327 PM CDT SUN JUL 19 2015 CONVECTION AND ATTENDANT HEAVY RAIN THREAT SHOULD BE ONGOING BY EARLY MONDAY MORNING ALONG AND NORTH OF THE I-70 CORRIDOR (AND ESPECIALLY WEST OF THE MISSISSIPPI RIVER), WITH THIS CONVECTION ROLLING EAST/SOUTHEAST ACROSS THE REGION DURING THE DAY. FOR NOW I`VE MAINTAINED A CLIMATOLOGICAL FLAVOR TO THE HEAVY RAIN THREAT AND PRIMARILY KEPT THIS MENTION DURING THE MORNING. IT`S CERTAINLY POSSIBLE SOME HEAVY RAIN WILL LINGER INTO THE AFTERNOON, BUT WILL LET MID SHIFT GET A BETTER LOOK AT TRENDS BEFORE EXPANDING FFA FURTHER IN EITHER AREA OR TIME. NO REAL CHANGES TO GOING FORECAST THROUGH TUESDAY, AS 12Z GUIDANCE CONTINUES TO INDICATE UPPER TROF DEEPENING OVER THE NORTHEAST CONUS WHICH WILL ALLOW SECONDARY COLD FRONT TO DROP INTO THE MID MISSISSIPPI VALLEY. THIS WILL GRADUALLY SUPPRESS THE THUNDERSTORM THREAT SOUTHWARD WHILE IT ALSO USHERING COOLER AND LESS HUMID AIR INTO THE FA WITH TIME. HOWEVER, THERE IS CONSIDERABLE DISAGREEMENT IN THE SYNOPTIC SOLUTIONS REGARDING THUNDERSTORM THREAT BY MIDWEEK, WITH GFS AND ECMWF MUCH FUTHER NORTH THAT NAM ON WEDNESDAY. FOR NOW GONE WITH A BLEND OF GUIDANCE, AND GENERALLY KEPT POPS IN THE CHANCE CATEGORY OVER SOUTHERN SECTIONS OF THE FA. MEDIUM RANGE SOLUTIONS ARE STILL FORECASTING REINTENSIFICATION OF UPPER RIDGE ACROSS THE AREA DURING THE LATTER HALF OF THE WEEK, BUT GUIDANCE CERTAINLY HINTS AT SOME THREAT OF CONVECTION EVEN AS HEIGHTS BUILD OVER THE REGION. BECAUSE OF THE THREAT DID NOT GO TOO EXTREME ON HIGH TEMPS, BUT IT SHOULD CERTAINLY MEAN A RETURN OF HIGH DEWPOINTS/APPARENT TEMPS AFTER THE MID-WEEK RESPITE. TRUETT && .AVIATION: (FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 639 PM CDT SUN JUL 19 2015 OUTFLOW BNDY CURRENTLY STRETCHES FROM KC REGION TO JUST S OF KJEF TO KFAM AREA. BELIEVE THIS WILL BE THE FOCUS FOR TSRA THIS EVE. EXPECT A TSRA COMPLEX TO DEVELOP ACROSS ERN KS OR WRN MO OVERNIGHT AND MOVE EWD IMPACTING TERMINALS DURING THE PRE-DAWN AND INTO MID MORNING HOURS. A BRIEF LULL MAY OCCUR DURING THE LATE MORNING HOURS FOR SUS/CPS AND PERHAPS COU BEFORE ANOTHER ROUND BEING POSSIBLE DURING THE AFTERNOON HRS. HOWEVER, THIS WILL GREATLY DEPEND ON TIMING OF MORNING CONVECTION AND EXACT PLACEMENT...WHICH MAY INSTEAD BE A MORE PROLONGED PERIOD OF STORMS BEFORE PUSHING S OF THE TERMINALS. UIN CURRENTLY HAS THE BEST CHANCE FOR DEVELOPING FG OVERNIGHT AND GOING FCST MAY NOT HAVE VSBYS LOW ENUF. OTHERWISE, EXPECT VFR CONDITIONS OUTSIDE OF TSRA. SPECIFICS FOR KSTL: EXPECT TSRA TO IMPACT TERMINAL AROUND SUNRISE MONDAY WITH A LULL IN THE LATE MORNING INTO AFTERNOON BEFORE ANOTHER ROUND POSSIBLE IN THE LATE AFTERNOON INTO EVE. && .PRELIMINARY POINT TEMPS/POPS: SAINT LOUIS 91 72 85 66 / 60 50 10 10 QUINCY 86 64 80 61 / 60 40 5 5 COLUMBIA 88 68 84 64 / 70 40 5 10 JEFFERSON CITY 89 69 84 65 / 70 50 10 10 SALEM 89 72 85 62 / 50 50 10 10 FARMINGTON 90 72 85 64 / 50 60 30 20 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR AUDRAIN MO-BOONE MO- CALLAWAY MO-COLE MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO- IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO- MARION MO-MONITEAU MO-MONROE MO-MONTGOMERY MO-OSAGE MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-WARREN MO- WASHINGTON MO. IL...FLASH FLOOD WATCH UNTIL NOON CDT TODAY FOR ADAMS IL-BOND IL- BROWN IL-CALHOUN IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-MONROE IL-MONTGOMERY IL-PIKE IL-ST. CLAIR IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1040 PM MDT SUN JUL 19 2015 UPDATED AVIATION SECTION .DISCUSSION... BOTH HRRR AND RUC ANALYSIS A BIT AGGRESSIVE IN DEVELOPING SHOWERS ACROSS PORTIONS OF THE HI-LINE THIS EVENING. MODELS CONTINUE TO BRING A WEAK BOUNDARY SOUTH ACROSS THE BORDER OVERNIGHT BUT HAVE LOWERED POPS UNTIL AFTER MIDNIGHT, WHEN SHOWERS ARE MORE LIKELY TO DEVELOP. TEMPERATURES LOOK GOOD. && .AVIATION... UPDATED 0440Z. MID-LEVEL CLOUDS WILL CONTINUE TO INCREASE AHEAD OF A BOUNDARY THAT WILL BRING A CHANCE OF SHOWERS TO THE HI-LINE AND PORTIONS OF NORTH CENTRAL MONTANA OVERNIGHT. THE AIRMASS WILL BECOME UNSTABLE AGAIN AFTER 18Z WITH SCATTERED AFTERNOON THUNDERSTORMS DEVELOPING. VFR CONDITIONS PREVAIL WITH MVFR CONDITIONS POSSIBLE IN THE VICINITY OF SHOWERS AND/OR THUNDERSTORMS ALONG WITH GUSTY ERRATIC WINDS. && .PREV DISCUSSION...ISSUED 257 PM MDT SUN JUL 19 2015 TONIGHT THROUGH TUESDAY...NORTHWEST FLOW ALOFT WILL CONTINUE OVERNIGHT THROUGH MID-DAY MONDAY BEFORE SHORTWAVE RIDGING MOVES OVER THE STATE. THIS FEATURE WILL BE WEAK AND TRANSIENT EXISTING JUST LONG ENOUGH TO SWITCH THE FLOW ALOFT TO WESTERLY BEFORE THE NEXT APPROACHING TROUGH BACKS IT AROUND TO THE SOUTHWEST AGAIN. MODELS CONTINUE TO BRING A WEAK BOUNDARY SOUTHWARD INTO NORTH CENTRAL MONTANA WITH ISOLATED TO SCATTERED SHOWERS DEVELOPING ALONG THE HI-LINE OVERNIGHT. SCATTERED SHOWERS AND A FEW THUNDERSTORMS CONTINUE THROUGH MONDAY MORNING BEFORE BECOMING ENHANCED BY A DISTURBANCE ALOFT MONDAY AFTERNOON AND EVENING. OVERNIGHT AIRMASS STABILITY IS EXPECTED TO DIMINISH THE SHOWERS LATE MONDAY NIGHT THROUGH TUESDAY MORNING. HOWEVER, INSTABILITY IN THE SOUTHWEST FLOW AHEAD OF THE NEXT TROUGH WILL TRIGGER ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS OVER SOUTHWEST MONTANA TUESDAY AFTERNOON. HIGH TEMPERATURES ON MONDAY AND TUESDAY WILL CLIMB 5 TO 10 DEGREES ABOVE SEASONAL AVERAGES. MPJ TUESDAY NIGHT THROUGH SUNDAY...AN UPPER LEVEL LOW PRESSURE TROF WILL MOVE OVER THE WEST COAST TUESDAY NIGHT. THIS WILL BRING A PERIOD OF FALLING HEIGHTS ALOFT WITH INCREASING INSTABILITY. THE BEST CHANCE FOR CONVECTION WILL BE OVER THE SOUTHWEST ZONES WHERE UNSETTLED SOUTHWEST FLOW ALOFT WILL ALSO BRING ADDITIONAL MOISTURE INTO THE AIRMASS. AN ASSOCIATED COLD FRONT WILL CROSS THE ROCKIES EARLY WEDNESDAY AND PUSH ACROSS THE ZONES. THIS FRONT DOES NOT LOOK QUITE AS STRONG AS EARLIER MODELS HAD FORECAST. THE TROF WILL BE BROADENING AND MOVING SLOWLY AS IT CROSSES THE PACIFIC NORTHWEST THURSDAY AND BY FRIDAY, AS IT MOVES OVER THE ZONES, FLOW ALOFT WILL BE NEARLY ZONAL. A WEAK RIDGE WILL BUILD OVER THE ZONES FRIDAY NIGHT BUT ANOTHER LOW PRESSURE TROF WILL BE APPROACHING THE WEST COAST AND HEIGHTS ALOFT OVER THE ZONES WILL ALREADY BE DROPPING BY SATURDAY. THE TROF WILL SLOWLY MOVE OVER THE PACIFIC NORTHWEST BY SUNDAY NIGHT AND THE AIRMASS WILL BECOME MORE UNSETTLED BY THE VERY END OF THE FORECAST PERIOD. ZELZER && .PRELIMINARY POINT TEMPS/POPS... GTF 57 87 57 90 / 10 30 20 10 CTB 53 84 52 85 / 20 30 10 10 HLN 60 89 60 92 / 10 20 20 20 BZN 53 87 53 89 / 10 20 20 10 WEY 42 74 43 76 / 10 10 10 30 DLN 51 83 52 85 / 10 20 20 20 HVR 56 87 56 93 / 30 20 30 10 LWT 55 84 56 89 / 20 20 20 20 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1207 PM CDT MON JUL 20 2015 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 316 AM CDT MON JUL 20 2015 REGIONAL RADAR MOSAIC SHOWING A COUPLE AREAS OF CONVECTION TO CONTEND WITH THIS MORNING. FIRST IS CLUSTER OF STORMS OVER SD PUSHING INTO THE NRN CWA ALONG A COLD FRONT THAT IS PROGGED TO PUSH DEEPER INTO THE CNTRL PLAINS LATER TODAY. MEANWHILE A LINE OF STORMS WAS LIFTING ACROSS KS ON NOSE OF LLVL JET/THETA-E ADV. LATEST HRRR/RAP13 ARE IN REASONABLE AGREEMENT AREAL COVERAGE WILL INCREASE AS ACTIVITY MERGES EARLY THIS MORNING...BUT THEN QUICKLY DISSIPATES BY LATE MORNING WHEN THE BNDRY MOVES SOUTH OF THE CWA. THE HRRR IS ALSO SHOWING POTENTIAL FOR POST-FRONTAL REDEVELOPMENT ALONG THE 850MB WARM FRONT/MID LYR AGEOSTROPHIC LIFT MAINLY OVER THE SRN CWA LATER THIS AFTN. RELATIVELY MILD CONDITIONS ON TAP THEN THROUGH AT LEAST WED AS AS COOLER AIR MASS REMAINS IN CONTROL OVER THE REGION. GOING FCST HAS SMALL POPS IN PLACE OVER THE SRN CWA WED NIGHT ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS/MO. WITH LATEST MODELS STILL SUPPORTING POSSIBLE DEVELOPMENT...SEE LITTLE REASON TO MAKE ANY CHANGES. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 316 AM CDT MON JUL 20 2015 OVERALL THE GFS/ECM/CMC MAY BE IN AGREEMENT IN REGARDS TO LARGE SCALE FLOW EVOLVING TO A LOW AMPLITUDE RIDGE PATTERN ENCOMPASSING THE CONUS HEADING INTO NEXT WEEKEND...BUT CONSIDERABLE DIFFERENCES SEEN IN REGARDS TO SFC FEATURES/FROPA. THIS BEST DEPICTED ON SAT/06Z WITH PCPN DEVELOPMENT PER THE GFS ASSOCIATED WITH A COLD FRONT DROPPING INTO THE CNTRL PLAINS. ECM ON THE OTHER HAND AT THAT TIME DEVELOPS PCPN ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS. GIVEN THAT THE EVOLVING PATTERN IS NOT ALL THAT FAVORABLE FOR PCPN ACTIVITY...HAVE TAKEN THE LIBERTY OF REMOVING POPS FROM MOST OF THE EXTENDED PDS EXCEPT FOR FRIDAY NIGHT LEAVING TOKEN 20S IN PLACE. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1205 PM CDT MON JUL 20 2015 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. A FEW-SCT CU ARE EXPECTED TODAY BEHIND THE COLD FRONT WITH NORTHWEST WINDS THAT WILL DIMINISH THIS EVENING. CLEAR SKIES ARE EXPECTED TONIGHT WITH WINDS BECOME SOUTHEAST ON TUE MORNING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DEE LONG TERM...DEE AVIATION...
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
626 AM CDT MON JUL 20 2015 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 316 AM CDT MON JUL 20 2015 REGIONAL RADAR MOSAIC SHOWING A COUPLE AREAS OF CONVECTION TO CONTEND WITH THIS MORNING. FIRST IS CLUSTER OF STORMS OVER SD PUSHING INTO THE NRN CWA ALONG A COLD FRONT THAT IS PROGGED TO PUSH DEEPER INTO THE CNTRL PLAINS LATER TODAY. MEANWHILE A LINE OF STORMS WAS LIFTING ACROSS KS ON NOSE OF LLVL JET/THETA-E ADV. LATEST HRRR/RAP13 ARE IN REASONABLE AGREEMENT AREAL COVERAGE WILL INCREASE AS ACTIVITY MERGES EARLY THIS MORNING...BUT THEN QUICKLY DISSIPATES BY LATE MORNING WHEN THE BNDRY MOVES SOUTH OF THE CWA. THE HRRR IS ALSO SHOWING POTENTIAL FOR POST-FRONTAL REDEVELOPMENT ALONG THE 850MB WARM FRONT/MID LYR AGEOSTROPHIC LIFT MAINLY OVER THE SRN CWA LATER THIS AFTN. RELATIVELY MILD CONDITIONS ON TAP THEN THROUGH AT LEAST WED AS AS COOLER AIR MASS REMAINS IN CONTROL OVER THE REGION. GOING FCST HAS SMALL POPS IN PLACE OVER THE SRN CWA WED NIGHT ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS/MO. WITH LATEST MODELS STILL SUPPORTING POSSIBLE DEVELOPMENT...SEE LITTLE REASON TO MAKE ANY CHANGES. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 316 AM CDT MON JUL 20 2015 OVERALL THE GFS/ECM/CMC MAY BE IN AGREEMENT IN REGARDS TO LARGE SCALE FLOW EVOLVING TO A LOW AMPLITUDE RIDGE PATTERN ENCOMPASSING THE CONUS HEADING INTO NEXT WEEKEND...BUT CONSIDERABLE DIFFERENCES SEEN IN REGARDS TO SFC FEATURES/FROPA. THIS BEST DEPICTED ON SAT/06Z WITH PCPN DEVELOPMENT PER THE GFS ASSOCIATED WITH A COLD FRONT DROPPING INTO THE CNTRL PLAINS. ECM ON THE OTHER HAND AT THAT TIME DEVELOPS PCPN ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS. GIVEN THAT THE EVOLVING PATTERN IS NOT ALL THAT FAVORABLE FOR PCPN ACTIVITY...HAVE TAKEN THE LIBERTY OF REMOVING POPS FROM MOST OF THE EXTENDED PDS EXCEPT FOR FRIDAY NIGHT LEAVING TOKEN 20S IN PLACE. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 623 AM CDT MON JUL 20 2015 MORNING SHOWERS/STORMS COULD SKIRT NEAR KOMA/KOFK...AND HAVE INCLUDED MENTION OF TSRA AT KOMA THIS MORNING. COLD FRONT FOLLOWS BEHIND THE SHOWERS/STORMS...WITH WINDS BECOMING NORTHWESTERLY AND INCREASING TO AROUND 10-14KT BY THIS AFTERNOON. MAY SEE SHOWERS OR AN ISOLATED STORM DEVELOP AGAIN NEAR KOMA/KLNK THIS AFTERNOON...BUT HAVE KEPT MENTION OUT FOR NOW WITH LOW CONFIDENCE ON DEVELOPMENT AND LOCATION. WINDS WILL DECREASE AFTER SUNDOWN TO AROUND 5KT OR LESS. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DEE LONG TERM...DEE AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
316 AM CDT MON JUL 20 2015 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 316 AM CDT MON JUL 20 2015 REGIONAL RADAR MOSAIC SHOWING A COUPLE AREAS OF CONVECTION TO CONTEND WITH THIS MORNING. FIRST IS CLUSTER OF STORMS OVER SD PUSHING INTO THE NRN CWA ALONG A COLD FRONT THAT IS PROGGED TO PUSH DEEPER INTO THE CNTRL PLAINS LATER TODAY. MEANWHILE A LINE OF STORMS WAS LIFTING ACROSS KS ON NOSE OF LLVL JET/THETA-E ADV. LATEST HRRR/RAP13 ARE IN REASONABLE AGREEMENT AREAL COVERAGE WILL INCREASE AS ACTIVITY MERGES EARLY THIS MORNING...BUT THEN QUICKLY DISSIPATES BY LATE MORNING WHEN THE BNDRY MOVES SOUTH OF THE CWA. THE HRRR IS ALSO SHOWING POTENTIAL FOR POST-FRONTAL REDEVELOPMENT ALONG THE 850MB WARM FRONT/MID LYR AGEOSTROPHIC LIFT MAINLY OVER THE SRN CWA LATER THIS AFTN. RELATIVELY MILD CONDITIONS ON TAP THEN THROUGH AT LEAST WED AS AS COOLER AIR MASS REMAINS IN CONTROL OVER THE REGION. GOING FCST HAS SMALL POPS IN PLACE OVER THE SRN CWA WED NIGHT ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS/MO. WITH LATEST MODELS STILL SUPPORTING POSSIBLE DEVELOPMENT...SEE LITTLE REASON TO MAKE ANY CHANGES. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 316 AM CDT MON JUL 20 2015 OVERALL THE GFS/ECM/CMC MAY BE IN AGREEMENT IN REGARDS TO LARGE SCALE FLOW EVOLVING TO A LOW AMPLITUDE RIDGE PATTERN ENCOMPASSING THE CONUS HEADING INTO NEXT WEEKEND...BUT CONSIDERABLE DIFFERENCES SEEN IN REGARDS TO SFC FEATURES/FROPA. THIS BEST DEPICTED ON SAT/06Z WITH PCPN DEVELOPMENT PER THE GFS ASSOCIATED WITH A COLD FRONT DROPPING INTO THE CNTRL PLAINS. ECM ON THE OTHER HAND AT THAT TIME DEVELOPS PCPN ASSOCIATED WITH A WARM FRONT LIFTING OUT OF KS. GIVEN THAT THE EVOLVING PATTERN IS NOT ALL THAT FAVORABLE FOR PCPN ACTIVITY...HAVE TAKEN THE LIBERTY OF REMOVING POPS FROM MOST OF THE EXTENDED PDS EXCEPT FOR FRIDAY NIGHT LEAVING TOKEN 20S IN PLACE. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1145 PM CDT SUN JUL 19 2015 OCCASIONAL MVFR CONDITIONS IN THUNDERSTORMS ARE POSSIBLE AT KOFK BETWEEN 06Z AND 12Z AS STORMS TRACK SOUTHEAST THROUGH NORTHEAST NEBRASKA. MORE STORMS PROGRESSING NORTHEAST FROM KANSAS WILL APPROACH KLNK BY 09Z AND KOMA BY 11Z...AND AGAIN COULD PRODUCE OCCASIONAL MVFR CONDITIONS. EXPECT SHOWERS OR STORMS TO MOVE SOUTHEAST OF ALL TAF SITES BEFORE 18Z...LEAVING NORTH WINDS BETWEEN 15 AND 25K FOR THE AFTERNOON WITH GRADUALLY SCATTERING CLOUDS. CLEAR SKIES AND LIGHT NORTH WINDS ARE FORECAST BY 00Z AND BEYOND AT ALL TAF SITES. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DEE LONG TERM...DEE AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1042 AM PDT MON JUL 20 2015 .SYNOPSIS...A DISTURBANCE STRETCHING FROM THE COAST TO THE SOUTHERN GREAT BASIN WILL AIDE IN SHOWER AND THUNDERSTORM DEVELOPMENT TODAY THROUGH TUESDAY. STORMS IN THIS TYPE OF ENVIRONMENT CAN PRODUCE LOCALLY HEAVY RAIN IN A SHORT PERIOD OF TIME AND RESULT IN FLASH FLOODING. ANYONE PLANNING OUTDOOR ACTIVITIES OR A TRIP IN THE NEXT COUPLE OF DAYS ARE ENCOURAGED TO REMAIN WEATHER AWARE. BY MID WEEK...DRIER AIR IS EXPECTED TO SPREAD ACROSS THE REGION BRINGING AN END TO THUNDERSTORM ACTIVITY THAT WILL LAST INTO THE WEEKEND. && .UPDATE...THICK CLOUD COVER IS HOLDING DOWN TEMPS SIGNIFICANTLY ACROSS MUCH OF THE AREA ESPECIALLY NORTH OF INTERSTATE 15. AS A RESULT, I LOWERED HIGH TEMPS IN THIS AREA ANYWHERE BETWEEN 3 AND 8 DEGREES ON AVERAGE. FURTHER SOUTH THE CLOUD SHIELD HAS ERODED AS DRIER AIR ALOFT HAS WORKED IN AND HIGH TEMPS LOOK MUCH MORE ACHIEVABLE HERE. UPDATED GRIDS AND ASSOCIATED PRODUCTS HAVE BEEN SENT OUT. && .PREVIOUS UPDATE...ISSUED AT 749 AM PDT MON JUL 20 105 WATER VAPOR SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW SWIRLING OFF THE COAST OF CALIFORNIA THIS MORNING WEST OF POINT CONCEPTION. MEANWHILE ACROSS SOUTHEAST CALIFORNIA THE MID-LEVEL WAVE AND ASSOCIATED PV MAX THAT HELPED TO TRIGGER THE OVERNIGHT CONVECTION WAS LIFTING NORTH TOWARD THE NEVADA BORDER. DRIER AIR WAS ALREADY EVIDENT WORKING ON NORTH. OVERALL POPS WERE ADJUSTED UP ACROSS MUCH OF LINCOLN, SOUTHERN NYE AND NORTHERN MOHAVE COUNTIES FOR THE REST OF THIS MORNING BASED ON THE LATEST RADAR RETURNS. POPS WERE ALSO BUMPED UP ACROSS THE NORTHWEST CWFA FOR THIS AFTERNOON AND EVENING BASED ON THE HRRR AND WRF AS THIS AREA SHOULD GET MORE ACTIVE GIVEN THE FEATURES PRESENT TO PROVIDE FORCING (APPROACHING JET STREAK, LOW OFFSHORE, WAVE RIDING NORTH). SOME ADJUSTMENTS WERE ALSO MADE FOR TUESDAY TO BETTER MATCH THE NEIGHBORING WFO`S AND GIVEN WE HAVE A FLASH FLOOD WATCH OUT. THE REST OF THE FORECAST LOOKS IN GOOD SHAPE AT THIS TIME. && .AVIATION...FOR MCCARRAN...CLOUD BASES WILL REMAIN BETWEEN 6 AND 11K FEET THROUGH EARLY THIS EVENING. A FEW SHRA AND POSSIBLY A TSRA THIS MORNING THOUGH IT APPEARS ANY HEAVIER TSRA ACTIVITY WOULD HOLD OFF UNTIL LATER THIS AFTERNOON OR EARLY THIS EVENING THAT WOULD DIRECTLY IMPACT THE AIRPORT COMPLEX. AWAY FROM ANY SHRA/TSRA OR OUTFLOW BOUNDARIES WINDS WILL MAINLY FAVOR DIURNAL DIRECTIONAL TRENDS THROUGH TONIGHT. SHOWERS AND THUNDERSTORMS WILL MOST PREVALENT IN THE BEATTY AND MORMON MESA CORRIDORS WITH ISOLATED SHRA/TSRA IN THE OTHER APPROACH CORRIDORS. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA AND SOUTHEAST CALIFORNIA...SHRA/TSRA ACTIVITY WILL SHIFT SLOWLY NORTH TODAY WITH DRIER CONDITIONS EXPECTED SOUTH OF INTERSTATE 40 BY THIS AFTERNOON. OUTSIDE OF THUNDERSTORM OUTFLOW, WINDS WILL GENERALLY FOLLOW DIURNAL DIRECTIONAL TRENDS THROUGH TONIGHT. BASES WILL MAINLY BE BETWEEN 7K AND 12K FEET LOWERING TO BETWEEN 4K AND 6K FEET NEAR ANY SHRA/TSRA. && .PREVIOUS DISCUSSION... ISSUED AT 244 AM PDT MON JUL 20 2015 .SHORT TERM...THROUGH WEDNESDAY NIGHT. TODAY COULD BE AN INTERESTING DAY ACROSS MUCH OF THE AREA, ESPECIALLY NORTH OF INTERSTATE 40 WITH VARIOUS BOUNDARIES FROM PREVIOUS DAY CONVECTION PROVIDING FOCUS FOR STORM INITIATION. IN ADDITION, THE REMNANTS OF DOLORES IS FORECAST TO COMBINE WITH LOW PRESSURE OFF THE WEST COAST WITH A 50KT JET FORECAST TO DEVELOP AROUND THE BASE OF THE LOW AND MOVE INTO SOUTHERN CALIFORNIA BECOMING AN EXTRA SOURCE OF LIFT. MODELS FORECAST DRIER, MORE STABLE AIR OVER SOUTHERN MOHAVE INTO SOUTHEAST SAN BERNARDINO COUNTY HEADING INTO THE AFTERNOON HOURS TODAY AND SHOWER ACTIVITY MAY SHUT DOWN EARLY THERE. A FLASH FLOOD WATCH REMAINS FOR MOST AREAS THROUGH MID DAY THEN THE SOUTHERN AREAS GET TRIMMED OUT AS THE DRIER AIR MOVES INTO THE DESERTS FOR THIS AFTERNOON. THE LOW OFF THE COAST OPENS UP TONIGHT AND CROSSES THE AREA TUESDAY WITH THE FOCUS FOR SHOWERS/STORMS SHIFTING MAINLY TO INYO COUNTY AND THE SOUTHERN GREAT BASIN. WEAK INSTABILITY EXTENDS INTO PORTIONS OF CLARK COUNTY ON TUESDAY AND THE MOUNTAINS COULD SEE A FEW SHOWERS AS WELL. BY WEDNESDAY, TROUGHING MOVES TO THE NORTHWEST COAST AND THE NORTHWEST CWA LIES IN THE RIGHT ENTRANCE REGION OF A 70+ KNOT JET PROVIDING SOME UPPER LEVEL SUPPORT FOR LINGERING MOISTURE IN THAT AREA FOR ANOTHER SHOT AT THUNDERSTORMS. DRIER, MORE STABLE AIR WILL BE IN PLACE ELSEWHERE AND MAINLY DRY CONDITIONS ARE EXPECTED. A WARMING TREND IS FORECAST THROUGH MID WEEK BUT TEMPERATURES WILL REMAIN BELOW NORMAL. .LONG TERM...THURSDAY THROUGH SUNDAY. LONG TERM STARTS OUT WITH A TROUGH EXTENDING FROM THE THE PAC NW SOUTHWARD INTO NORTHERN CALIFORNIA. MODELS STILL TRYING TO DEVELOP A CONVERGENCE ZONE FROM NEAR BISHOP NORTHEAST INTO CENTRAL NEVADA THURSDAY. ADDED SLIGHTLY HIGHER POPS TO NORTHERN ESMERALDA COUNTY AS AN ISOLATED SHOWER OR THUNDERSTORM COULD DEVELOP. OTHERWISE, DRIER SOUTHWEST FLOW WILL TRANSLATE TO A BREEZY AFTERNOON ALONG WITH WARMER TEMPERATURES. FRIDAY AND SATURDAY WILL BE DRY AND WARMER YET WITH TEMPERATURES NEAR SEASONAL NORMALS. FOR SUNDAY...INCREASED POPS ACROSS EASTERN MOHAVE AS MONSOON MOISTURE COULD SNEAK BACK WEST INTO THE COUNTY. REMAINDER OF THE AREA LOOKS TO STAY DRY WITH SEASONABLE TEMPERATURES. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED TODAY AND/OR TUESDAY. REPORTS OF FLASH FLOODING, THUNDERSTORM WINDS, DUST, HAIL AND RELATED DAMAGE AS WELL AS RAINFALL TOTALS ARE ENCOURAGED. SPOTTER ACTIVATION IS NOT EXPECTED BEYOND WEDNESDAY THROUGH NEXT WEEKEND. && $$ UPDATE/AVIATION...STACHELSKI PREVIOUS...SALMEN/PIERCE FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
749 AM PDT MON JUL 20 2015 .SYNOPSIS...A DISTURBANCE STRETCHING FROM THE COAST TO THE SOUTHERN GREAT BASIN WILL AIDE IN SHOWER AND THUNDERSTORM DEVELOPMENT TODAY THROUGH TUESDAY. STORMS IN THIS TYPE OF ENVIRONMENT CAN PRODUCE LOCALLY HEAVY RAIN IN A SHORT PERIOD OF TIME AND RESULT IN FLASH FLOODING. ANYONE PLANNING OUTDOOR ACTIVITIES OR A TRIP IN THE NEXT COUPLE OF DAYS ARE ENCOURAGED TO REMAIN WEATHER AWARE. BY MID WEEK...DRIER AIR IS EXPECTED TO SPREAD ACROSS THE REGION BRINGING AN END TO THUNDERSTORM ACTIVITY THAT WILL LAST INTO THE WEEKEND. && .UPDATE...WATER VAPOR SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW SWIRLING OFF THE COAST OF CALIFORNIA THIS MORNING WEST OF POINT CONCEPTION. MEANWHILE ACROSS SOUTHEAST CALIFORNIA THE MID-LEVEL WAVE AND ASSOCIATED PV MAX THAT HELPED TO TRIGGER THE OVERNIGHT CONVECTION WAS LIFTING NORTH TOWARD THE NEVADA BORDER. DRIER AIR WAS ALREADY EVIDENT WORKING ON NORTH. OVERALL POPS WERE ADJUSTED UP ACROSS MUCH OF LINCOLN, SOUTHERN NYE AND NORTHERN MOHAVE COUNTIES FOR THE REST OF THIS MORNING BASED ON THE LATEST RADAR RETURNS. POPS WERE ALSO BUMPED UP ACROSS THE NORTHWEST CWFA FOR THIS AFTERNOON AND EVENING BASED ON THE HRRR AND WRF AS THIS AREA SHOULD GET MORE ACTIVE GIVEN THE FEATURES PRESENT TO PROVIDE FORCING (APPROACHING JET STREAK, LOW OFFSHORE, WAVE RIDING NORTH). SOME ADJUSTMENTS WERE ALSO MADE FOR TUESDAY TO BETTER MATCH THE NEIGHBORING WFO`S AND GIVEN WE HAVE A FLASH FLOOD WATCH OUT. THE REST OF THE FORECAST LOOKS IN GOOD SHAPE AT THIS TIME. && .AVIATION...FOR MCCARRAN...CLOUD BASES WILL REMAIN BETWEEN 6 AND 11K FEET THROUGH EARLY THIS EVENING. A FEW SHRA AND POSSIBLY A TSRA THIS MORNING THOUGH IT APPEARS ANY HEAVIER TSRA ACTIVITY WOULD HOLD OFF UNTIL LATER THIS AFTERNOON OR EARLY THIS EVENING THAT WOULD DIRECTLY IMPACT THE AIRPORT COMPLEX. AWAY FROM ANY SHRA/TSRA OR OUTFLOW BOUNDARIES WINDS WILL MAINLY FAVOR DIURNAL DIRECTIONAL TRENDS THROUGH TONIGHT. SHOWERS AND THUNDERSTORMS WILL MOST PREVALENT IN THE BEATTY AND MORMON MESA CORRIDORS WITH ISOLATED SHRA/TSRA IN THE OTHER APPROACH CORRIDORS. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA AND SOUTHEAST CALIFORNIA...SHRA/TSRA ACTIVITY WILL SHIFT SLOWLY NORTH TODAY WITH DRIER CONDITIONS EXPECTED SOUTH OF INTERSTATE 40 BY THIS AFTERNOON. OUTSIDE OF THUNDERSTORM OUTFLOW, WINDS WILL GENERALLY FOLLOW DIURNAL DIRECTIONAL TRENDS THROUGH TONIGHT. BASES WILL MAINLY BE BETWEEN 7K AND 12K FEET LOWERING TO BETWEEN 4K AND 6K FEET NEAR ANY SHRA/TSRA. && .PREVIOUS DISCUSSION... ISSUED AT 244 AM PDT MON JUL 20 2015 .SHORT TERM...THROUGH WEDNESDAY NIGHT. TODAY COULD BE AN INTERESTING DAY ACROSS MUCH OF THE AREA, ESPECIALLY NORTH OF INTERSTATE 40 WITH VARIOUS BOUNDARIES FROM PREVIOUS DAY CONVECTION PROVIDING FOCUS FOR STORM INITIATION. IN ADDITION, THE REMNANTS OF DOLORES IS FORECAST TO COMBINE WITH LOW PRESSURE OFF THE WEST COAST WITH A 50KT JET FORECAST TO DEVELOP AROUND THE BASE OF THE LOW AND MOVE INTO SOUTHERN CALIFORNIA BECOMING AN EXTRA SOURCE OF LIFT. MODELS FORECAST DRIER, MORE STABLE AIR OVER SOUTHERN MOHAVE INTO SOUTHEAST SAN BERNARDINO COUNTY HEADING INTO THE AFTERNOON HOURS TODAY AND SHOWER ACTIVITY MAY SHUT DOWN EARLY THERE. A FLASH FLOOD WATCH REMAINS FOR MOST AREAS THROUGH MID DAY THEN THE SOUTHERN AREAS GET TRIMMED OUT AS THE DRIER AIR MOVES INTO THE DESERTS FOR THIS AFTERNOON. THE LOW OFF THE COAST OPENS UP TONIGHT AND CROSSES THE AREA TUESDAY WITH THE FOCUS FOR SHOWERS/STORMS SHIFTING MAINLY TO INYO COUNTY AND THE SOUTHERN GREAT BASIN. WEAK INSTABILITY EXTENDS INTO PORTIONS OF CLARK COUNTY ON TUESDAY AND THE MOUNTAINS COULD SEE A FEW SHOWERS AS WELL. BY WEDNESDAY, TROUGHING MOVES TO THE NORTHWEST COAST AND THE NORTHWEST CWA LIES IN THE RIGHT ENTRANCE REGION OF A 70+ KNOT JET PROVIDING SOME UPPER LEVEL SUPPORT FOR LINGERING MOISTURE IN THAT AREA FOR ANOTHER SHOT AT THUNDERSTORMS. DRIER, MORE STABLE AIR WILL BE IN PLACE ELSEWHERE AND MAINLY DRY CONDITIONS ARE EXPECTED. A WARMING TREND IS FORECAST THROUGH MID WEEK BUT TEMPERATURES WILL REMAIN BELOW NORMAL. .LONG TERM...THURSDAY THROUGH SUNDAY. LONG TERM STARTS OUT WITH A TROUGH EXTENDING FROM THE THE PAC NW SOUTHWARD INTO NORTHERN CALIFORNIA. MODELS STILL TRYING TO DEVELOP A CONVERGENCE ZONE FROM NEAR BISHOP NORTHEAST INTO CENTRAL NEVADA THURSDAY. ADDED SLIGHTLY HIGHER POPS TO NORTHERN ESMERALDA COUNTY AS AN ISOLATED SHOWER OR THUNDERSTORM COULD DEVELOP. OTHERWISE, DRIER SOUTHWEST FLOW WILL TRANSLATE TO A BREEZY AFTERNOON ALONG WITH WARMER TEMPERATURES. FRIDAY AND SATURDAY WILL BE DRY AND WARMER YET WITH TEMPERATURES NEAR SEASONAL NORMALS. FOR SUNDAY...INCREASED POPS ACROSS EASTERN MOHAVE AS MONSOON MOISTURE COULD SNEAK BACK WEST INTO THE COUNTY. REMAINDER OF THE AREA LOOKS TO STAY DRY WITH SEASONABLE TEMPERATURES. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED TODAY AND/OR TUESDAY. REPORTS OF FLASH FLOODING, THUNDERSTORM WINDS, DUST, HAIL AND RELATED DAMAGE AS WELL AS RAINFALL TOTALS ARE ENCOURAGED. SPOTTER ACTIVATION IS NOT EXPECTED BEYOND WEDNESDAY THROUGH NEXT WEEKEND. && $$ UPDATE/AVIATION...STACHELSKI PREVIOUS...SALMEN/PIERCE FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1045 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COMBINED TROF OF LOW PRESSURE AND COLD FRONT WILL DROP INTO THE REGION LATE TONIGHT AND WEDNESDAY BRINGING A SLIGHT REDUCTION IN THE HEAT. THE FRONT/TROF COMBO WILL PUSH OFF TO THE SOUTH BY FRIDAY...BRINGING GENERALLY A DRYING TREND INTO THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 1030 PM TUESDAY...THE FA IS UNDER THE SOUTHERN END OF A BROKEN LINE OF CONVECTION PUSHING ACROSS THE NORTHERN PORTIONS OF THE ILM CWA...AND SHOULD BE OFF THE COAST AROUND OR JUST AFTER MIDNIGHT. HAVE UPDATED POPS TO ACCOUNT THE ISOLATED CONVECTIVE NATURE ELSEWHERE ACROSS THE ILM CWA. THE SFC TROF/COOL FRONT COMBO ORIENTED ENE-WSW...SHOULD PUSH TO OR JUST OFF THE ILM CWA COASTS AROUND OR JUST AFTER DAYBREAK. LOOK FOR WINDS TO VEER TO THE NW TO N AFTER THIS BOUNDARYS PASSAGE. IN FACT...HAVE INCLUDED SOME PATCHY FOG ACROSS AREAS...ESPECIALLY LOCATIONS HAVING RECEIVED RAINFALL. TEMPS/DEWPTS RELATIVELY UNCHANGED FROM PREVIOUS UPDATE. OVERALL...HRRR MODEL HAD THE GENERAL TRENDS WITH THE PASSAGE OF CONVECTION ACROSS THE FA...WITH THE WORSE CONVECTION N THRU NE OF THE ILM CWA. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...BOTH THE GFS AND NAM SHOW A COLD FRONT APPROACHING THE COAST AT SUNRISE IN THE MORNING AND IS EXPECTED TO STALL ALONG THE SOUTHERN BORDER OF THE FORECAST AREA. A LOW IS FORECAST TO DEVELOP ALONG THE FRONT ON THURSDAY MORNING WILL PUSH THIS FRONT FARTHER TO THE SOUTH. THE EXPECTATIONS OF THIS FRONT IS TO SLIGHT BREAK IN THE HIGHER TEMPERATURES WE HAVE SEEN THE LAST SEVERAL DAYS. AREAS SOUTHWEST OF A LINE FROM DARLINGTON TO GEORGETOWN WILL HAVE WAIT AS TEMPERATURES ARE EXPECTED TO BE IN THE MIDDLE 90S AGAIN ON WEDNESDAY WITH THE LOWER 90S ELSEWHERE. ON THURSDAY TEMPERATURES ARE EXPECTED TO RANGE FROM NEAR 90 IN THE NORTHERN SECTIONS OF SOUTHEAST NORTH CAROLINA TO THE 92 TO 95 RANGE ACROSS SOUTHERN PORTIONS OF NORTHEAST SOUTH CAROLINA. WITH THE FRONTAL PASSAGE A 20 TO 30 PERCENT CHANCE OF THUNDERSTORMS IS EXPECTED ON WEDNESDAY AND CHANCES WILL INCREASE TO A 40 TO 50 PERCENT CHANCE WITH THE LOW RIDING ALONG THE COLD FRONT WEDNESDAY NIGHT INTO THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...THE MID LEVEL PATTERN WILL CONSIST OF STRONG RIDGING ACROSS THE FOUR CORNERS OF THE U.S WITH TROUGHING ACROSS THE EAST...AT LEAST INITIALLY. THE RIDGE WILL BUILD BACK TO THE EAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK LEAVING A WEAKER NORTHWEST FLOW ACROSS THE EASTERN CAROLINAS. THERE ARE INDICATIONS IN SOME OF THE GUIDANCE THAT A COUPLE OF STRONGER SHORTWAVES WILL MOVE ACROSS THIS FLOW NEXT TUESDAY THUS INCREASING THE CHANCE OF CONVECTION. THE HIGHEST POPS OF THE PERIOD WILL RESIDE HERE. FOR FRIDAY TROUGH MONDAY WEAK HIGH PRESSURE IN THE WAKE OF THE MID LEVEL TROUGH WILL KEEP CONDITIONS MOSTLY DRY WITH PRECIPITABLE WATER VALUES WELL BELOW 1.5 INCHES. TEMPERATURES WILL BE AT OR NEAR CLIMATOLOGY THROUGHOUT THE PERIOD. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...FRONTAL BOUNDARY SHOWS UP ON WATER VAPOR AS A HIGHER MOISTURE BOUNDARY JUST WEST OF THE CWA. EVEN WITH DIURNAL COOLING...EXPECT CONVECTION TO MOVE INTO THE WESTERN PORTION OF THE CWA BY TAF TIME...SLOWLY WEAKENING AND ALL BUT ENDING BY 02-03Z. AFTER SOME CONVECTIVE DEBRIS SUBSIDES...EXPECT SOME LIGHT FOG TO DEVELOP...PARTICULARLY AREAS THAT RECEIVED ANY RAIN. WINDS WILL SHIFT LATE TONIGHT TO THE NORTH AS THE FRONTAL BOUNDARY DROPS IN. SOME BRIEF STRATUS IS ALSO POSSIBLE POST FRONTAL...HOWEVER CONFIDENCE IS RATHER LOW. WEDNESDAY...LIGHT NORTHERLY WINDS WITH ISOLATED CONVECTION IN THE AFTERNOON. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM ISOLATED CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1030 PM TUESDAY...BASED ON LATEST WIND AND SEAS REPORTS/TRENDS AND HRRR PROGRESSION OF WX FEATURES...HAVE TWEAKED BOTH WIND AND SIGNIFICANT SEAS FOR THE REMAINDER OF THIS EVENING AND OVERNIGHT. LOOKING AT MAINLY A SLOW VEERING WIND DIRECTION CHANGE AFTER MIDNIGHT THROUGH THE PRE-DAWN WED HOURS. WILL LIKELY SEE W-NW WIND DIRECTIONS BY DAYBREAK WED. WIND SPEEDS WILL BE SLOWER TO DROP DUE TO THE SLOWER PROGRESSION OF THE SFC TROF AXIS TO AND EVENTUALLY ACROSS THE AREA WATERS...MORE-SO OCCURRING AFTER DAYBREAK WED. SIGNIFICANT SEAS ALSO A BIT SLOWER TO SUBSIDE. WIND DRIVEN WAVES AT 4 TO 5 SECOND PERIODS TO DOMINATE THE SIGNIFICANT SEAS WITH A CONTINUED UNDERLYING LAZY 1 FOOT OR LESS SE GROUND SWELL. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A COLD FRONT WILL APPROACH THE WATERS EARLY WEDNESDAY MORNING AND SLOWLY MOVE ACROSS ALONG THE COASTAL WATERS TO JUST SOUTH OF THE LOWER SANTEE. A LOW PRESSURE AREA IS EXPECTED TO DEVELOP ALONG THE FRONT OVERNIGHT WEDNESDAY AND DRIVE THIS FRONT FARTHER SOUTH. WINDS ARE EXPECTED TO BE SWITCHING TO THE THE NORTHWEST TO WEST BY MORNING TO MID-MORNING WITH SPEEDS AROUND 10 TO 15 KNOTS. BY THURSDAY NIGHT WINDS WILL BE BACK FROM THE SOUTHWEST AT 10 TO 15 KNOTS. SEAS WILL RANGE BETWEEN 2 TO 4 FEET THROUGHOUT THE PERIOD. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...WEAK HIGH PRESSURE WILL RESIDE ALONG THE APPALACHIANS FRIDAY AND SATURDAY. THIS WILL BRING A NORTHEASTERLY FLOW OF TEN KNOTS OR SO TO THE WATERS THROUGH SATURDAY. BY SUNDAY THE HIGH WEAKENS SUFFICIENTLY WITH A VERY WEAK PRESSURE PATTERN ENSUING. A MORE EAST TO SOUTHEASTERLY ONSHORE FLOW WILL DEVELOP MAINLY DUE TO THE SEA BREEZE. SEAS...REMAINING WEAKLY FORCED THROUGH THE PERIOD WILL BE 1-3 FEET FOR THE MOST PART. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DCH NEAR TERM...DCH SHORT TERM...DRH LONG TERM...SHK AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
755 PM EDT TUE JUL 21 2015 .SYNOPSIS... A COLD FRONT WILL DROP INTO THE REGION TOMORROW AND BRINGING A SLIGHT REDUCTION IN THE HEAT ALONG WITH BETTER RAIN CHANCES. THE FRONT WILL PUSH OFF TO THE SOUTH ON FRIDAY...BRINGING GENERALLY A DRYING TREND INTO NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 730 PM TUESDAY...EXCESSIVE HEAT WARNING AND HEAT ADV ALLOWED TO EXPIRE AT 700 PM. A DEGREE OR 2 COOLING IN THE MID-LEVELS ACROSS THE FA STILL A POSSIBILITY THIS EVENING BEFORE CHANCES FOR CONVECTION LOWER QUICKLY DUE TO THE LOSS OF DAYTIME INSOLATION BY MID-EVENING. THE BROKEN LINE OF CONVECTION ENTERING THE NW PORTIONS OF THE ILM CWA...IS PROGGED BY THE HRRR TO TRAVERSE THE ILM CWA FROM NW-SE AND OFF THE ILM CWA COAST AROUND MIDNIGHT. THEIR STRENGTH REMAINS SUSPECT BUT FOR NOW WILL INDICATE AN ISOLATED 30-45 MPH WIND GUST POSSIBLE. HAIL CHANCES VERY LOW WITH CURRENT AND PROGGED VILS WELL BELOW 1 INCH THRESHOLDS. OVERALL...POPS TO PEAK IN THE LOW TO MODEST CHANCE...20-40 PERCENT THIS EVENING...DROPPING QUICKLY BY THE EARLY AM HOURS OF WED. HAVE UPDATED OVERNIGHT MINS...HRLY DEWPOINTS AND WINDS TO ACCOUNT FOR THE LIMITED INLAND PROGRESSION OF THE SEA BREEZE AND THE PCPN MOVING ACROSS THE FA OVERNIGHT. WILL STAY CLOSE TO USE THE LATEST PROGRESSION OF THE VARIOUS WX FEATURES THROUGH THE HRRR MODEL. PREVIOUS........................................................ AS OF 3 PM TUESDAY...AN AXIS OF ENHANCED MID-LEVEL MOISTURE AND UPPER SUPPORT IS CURRENTLY CROSSING THE MOUNTAINS. A DOME OF WARM H5-H3 AIR REMAINS ENTRENCHED ACROSS THE FORECAST AREA AS AN UPPER RIDGE CONTINUES TO UNDERGO SHEAR FROM SHORT-WAVE ENERGY MOVING ACROSS THE OHIO VALLEY. AS THE PLUME OF DYNAMICAL SUPPORT ALOFT APPROACHES...CONVECTION WILL BEGIN TO BLOSSOM IN VICINITY OF A PIEDMONT TROUGH WEST OF I-95. SEVERAL DISCREET CELLS WILL ALSO BE CAPABLE OF POPPING ALONG THE SEA BREEZE AHEAD OF THE ASCENT ZONE. MODERATE MID-LEVEL FLOW AND DOWNDRAFT CAPES COULD RESULT ISOLATED SEVERE WIND GUSTS LATE THIS AFTERNOON AND EVENING. SPC MAINTAINS A MARGINAL RISK ACROSS THE AREA. AS THE SHORT-WAVE ALOFT PROGRESSES TOWARD THE COAST...IT WILL FORCE THE HAND OF THE SURFACE TROUGH INLAND TO GAIN A SE MIGRATION AS A WEAK COLD FRONT ACROSS THE AREA INTO EARLY WEDNESDAY. THIS FEATURE MAY SERVE AS A FOCUS FOR ONGOING CONVECTION OVERNIGHT. MINIMUMS MIDDLE 70S INLAND TO LOW 80S ALONG THE COAST BY DAYBREAK WEDNESDAY. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...BOTH THE GFS AND NAM SHOW A COLD FRONT APPROACHING THE COAST AT SUNRISE IN THE MORNING AND IS EXPECTED TO STALL ALONG THE SOUTHERN BORDER OF THE FORECAST AREA. A LOW IS FORECAST TO DEVELOP ALONG THE FRONT ON THURSDAY MORNING WILL PUSH THIS FRONT FARTHER TO THE SOUTH. THE EXPECTATIONS OF THIS FRONT IS TO SLIGHT BREAK IN THE HIGHER TEMPERATURES WE HAVE SEEN THE LAST SEVERAL DAYS. AREAS SOUTHWEST OF A LINE FROM DARLINGTON TO GEORGETOWN WILL HAVE WAIT AS TEMPERATURES ARE EXPECTED TO BE IN THE MIDDLE 90S AGAIN ON WEDNESDAY WITH THE LOWER 90S ELSEWHERE. ON THURSDAY TEMPERATURES ARE EXPECTED TO RANGE FROM NEAR 90 IN THE NORTHERN SECTIONS OF SOUTHEAST NORTH CAROLINA TO THE 92 TO 95 RANGE ACROSS SOUTHERN PORTIONS OF NORTHEAST SOUTH CAROLINA. WITH THE FRONTAL PASSAGE A 20 TO 30 PERCENT CHANCE OF THUNDERSTORMS IS EXPECTED ON WEDNESDAY AND CHANCES WILL INCREASE TO A 40 TO 50 PERCENT CHANCE WITH THE LOW RIDING ALONG THE COLD FRONT WEDNESDAY NIGHT INTO THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...THE MID LEVEL PATTERN WILL CONSIST OF STRONG RIDGING ACROSS THE FOUR CORNERS OF THE U.S WITH TROUGHING ACROSS THE EAST...AT LEAST INITIALLY. THE RIDGE WILL BUILD BACK TO THE EAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK LEAVING A WEAKER NORTHWEST FLOW ACROSS THE EASTERN CAROLINAS. THERE ARE INDICATIONS IN SOME OF THE GUIDANCE THAT A COUPLE OF STRONGER SHORTWAVES WILL MOVE ACROSS THIS FLOW NEXT TUESDAY THUS INCREASING THE CHANCE OF CONVECTION. THE HIGHEST POPS OF THE PERIOD WILL RESIDE HERE. FOR FRIDAY TROUGH MONDAY WEAK HIGH PRESSURE IN THE WAKE OF THE MID LEVEL TROUGH WILL KEEP CONDITIONS MOSTLY DRY WITH PRECIPITABLE WATER VALUES WELL BELOW 1.5 INCHES. TEMPERATURES WILL BE AT OR NEAR CLIMATOLOGY THROUGHOUT THE PERIOD. && .AVIATION /23Z TUESDAY THROUGH SUNDAY/... AS OF 00Z...FRONTAL BOUNDARY SHOWS UP ON WATER VAPOR AS A HIGHER MOISTURE BOUNDARY JUST WEST OF THE CWA. EVEN WITH DIURNAL COOLING...EXPECT CONVECTION TO MOVE INTO THE WESTERN PORTION OF THE CWA BY TAF TIME...SLOWLY WEAKENING AND ALL BUT ENDING BY 02-03Z. AFTER SOME CONVECTIVE DEBRIS SUBSIDES...EXPECT SOME LIGHT FOG TO DEVELOP...PARTICULARLY AREAS THAT RECEIVED ANY RAIN. WINDS WILL SHIFT LATE TONIGHT TO THE NORTH AS THE FRONTAL BOUNDARY DROPS IN. SOME BRIEF STRATUS IS ALSO POSSIBLE POST FRONTAL...HOWEVER CONFIDENCE IS RATHER LOW. WEDNESDAY...LIGHT NORTHERLY WINDS WITH ISOLATED CONVECTION IN THE AFTERNOON. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM ISOLATED CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 730 PM TUESDAY...BASED ON LATEST WIND AND SEAS REPORTS/TRENDS AND HRRR PROGRESSION OF WX FEATURES...OF UPDATED BOTH WIND AND SIGNIFICANT SEAS THIS EVENING AND OVERNIGHT. LOOKING AT MAINLY A SLOW VEERING WIND DIRECTION CHANGE AFTER MIDNIGHT THROUGH THE PRE-DAWN WED HOURS. COULD SEE W-NW BY DAYBREAK WED. WIND SPEEDS WILL BE SLOWER TO DROP DUE TO THE SLOWER PROGRESSION OF THE SFC TROF AXIS TO AND EVENTUALLY ACROSS THE AREA WATERS...MORE-SO OCCURRING RIGHT AFTER DAYBREAK WED. SIGNIFICANT SEAS ALSO A BIT SLOWER TO SUBSIDE. WIND DRIVEN WAVES AT 4 TO 5 SECOND PERIODS TO DOMINATE THE SIGNIFICANT WITH A CONTINUED UNDERLYING VERY LAZY 1 FOOT OR LESS GROUND SWELL. PREVIOUS..................................................... AS OF 3 PM TUESDAY...MODERATELY BUMPY MARINE CONDITIONS ON TAP FOR 15-20 KT SW WINDS AND 3-4 FOOT SEAS. SEAS MAINLY COMPRISED OF SSW WAVES AROUND 3-4 FT EVERY 6 SECONDS AND ESE WAVES 1-2 FT EVERY 9 SECONDS. A FEW TSTMS COULD TRACK EAST ACROSS THE COASTAL WATERS AT 25 TO 30 KT OVERNIGHT...CAPABLE OF LOCALLY STRONG GUSTS AND GENERATION OF LOCALLY HIGHER WIND-WAVES. AN EXERCISE CAUTION STATEMENT MAY BE NEEDED OVERNIGHT INTO WEDNESDAY IF 5 FT SEAS EXPAND INTO THE 20NM CORRIDOR. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A COLD FRONT WILL APPROACH THE WATERS EARLY WEDNESDAY MORNING AND SLOWLY MOVE ACROSS ALONG THE COASTAL WATERS TO JUST SOUTH OF THE LOWER SANTEE. A LOW PRESSURE AREA IS EXPECTED TO DEVELOP ALONG THE FRONT OVERNIGHT WEDNESDAY AND DRIVE THIS FRONT FARTHER SOUTH. WINDS ARE EXPECTED TO BE SWITCHING TO THE THE NORTHWEST TO WEST BY MORNING TO MID-MORNING WITH SPEEDS AROUND 10 TO 15 KNOTS. BY THURSDAY NIGHT WINDS WILL BE BACK FROM THE SOUTHWEST AT 10 TO 15 KNOTS. SEAS WILL RANGE BETWEEN 2 TO 4 FEET THROUGHOUT THE PERIOD. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...WEAK HIGH PRESSURE WILL RESIDE ALONG THE APPALACHIANS FRIDAY AND SATURDAY. THIS WILL BRING A NORTHEASTERLY FLOW OF TEN KNOTS OR SO TO THE WATERS THROUGH SATURDAY. BY SUNDAY THE HIGH WEAKENS SUFFICIENTLY WITH A VERY WEAK PRESSURE PATTERN ENSUING. A MORE EAST TO SOUTHEASTERLY ONSHORE FLOW WILL DEVELOP MAINLY DUE TO THE SEA BREEZE. SEAS...REMAINING WEAKLY FORCED THROUGH THE PERIOD WILL BE 1-3 FEET FOR THE MOST PART. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...DRH NEAR TERM...DCH/MJC SHORT TERM...DRH LONG TERM...SHK AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
258 PM EDT MON JUL 20 2015 .SYNOPSIS... OPPRESSIVE HEAT WILL CONTINUE THROUGH TUESDAY. WEDNESDAY A COLD FRONT WILL DROP INTO THE AREA AND LESSEN THE HEAT WHILE INCREASING THUNDERSTORM CHANCES. THIS BOUNDARY WILL SLOWLY SLIP OFF TO THE SOUTH ON FRIDAY. COOLER AND DRIER HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST FOR THE WEEKEND AND START OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM MONDAY...PREVIOUS UPDATES TO THE CURRENT FCST STILL LOOKS AOK THRU THIS EVENING. WIDELY SCATTERED WEAK CONVECTIVE ACTIVITY IN THE VICINITY OF THE PIEDMONT TROF HAS DEVELOPED AND IS IN LINE WITH THE EARLIER HRRR PROGGED REFLECTIVITY DISPLAY. THIS UPDATE IS CONCERNED WITH TWEAKS WITH TONIGHTS LOWS. VARIOUS MODEL GUIDANCE FOR TONIGHT LOWS HAVE INCREASED BY A DEGREE OR 3 FROM PREVIOUS RUNS AND THEREFORE HAVE UPDATED THE LOWS TO THE 76-81 DEGREE RANGE...WITH THE LOW 80S ALONG THE IMMEDIATE COAST WHERE LOCAL SSTS ARE IN THE 80S. THIN/OPAQUE CLOUDS WILL BECOME MAINLY THIN THIS EVENING AND OVERNIGHT. ACTIVE WINDS IN THE 5 MPH INLAND...5 TO 10 MPH ALONG THE COAST SHOULD KEEP FOG AT BAY. PREVIOUS.......................................................... AS OF 1145 AM MONDAY...TWEAKED AFTN/EVENING WINDS ACROSS THE FA...MAINLY CLOSER TO THE COAST WITH RESPECT TO THE SEA BREEZE AND ITS FORWARD AND LIMITED INLAND PROGRESSION. HAVE CONTINUED WITH GUSTS AOA 20 MPH ALONG THE IMMEDIATE COAST LATER THIS AFTN AND EVENING TO ACCOUNT FOR THE STRENGTH OF TODAYS SEA BREEZE. IN ADDITION...FURTHER LIMITED AFTN AND EVENING CLOUD COVERAGE BASED ON LATEST SATELLITE VIS TRENDS AND LESS COVERAGE OF CONVECTION UPSTREAM AND ACROSS THE FA WHICH IN TURN WILL LIMIT CONVECTIVE DEBRIS CLOUDINESS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...PROGRESSIVE MID LEVEL PATTERN DEVELOPING DURING THE PERIOD WILL PUSH A WEAK COLD FRONT INTO THE AREA LATE TUE NIGHT. FRONT STALLS ON WED AS THE BOUNDARY ENDS UP LAYING PARALLEL TO THE STEERING FLOW. DEEP MOISTURE WILL BE PRESENT THROUGH THE PERIOD WITH PRECIPITABLE WATER VALUES RUNNING RIGHT AROUND 2 INCHES. AHEAD OF THE FRONT ON TUE THE PIEDMONT TROUGH AND SEA BREEZE WILL BE THE FOCAL POINT FOR DEEPER CONVECTION. COVERAGE ON TUE IS LIKELY TO BE SOMEWHAT LIMITED AS THERE WILL STILL BE SOME WEAK MID LEVEL SUBSIDENCE ASSOCIATED WITH THE RETREATING 5H RIDGE CENTERED OVER TX. INHERITED LOW CHC POP MESHES WELL WITH VARIOUS GUIDANCE FOR TUE SO PLAN ONLY MINOR TWEAKS. COMBINATION OF LOW LEVEL SOUTHWEST FLOW...INCREASING IN THE AFTERNOON...AND WEAK MID LEVEL SUBSIDENCE WILL ONCE AGAIN RESULT IN HIGHS ABOVE CLIMO. TEMPS IN THE MID TO UPPER 90S AND ABUNDANT MOISTURE WILL AGAIN PUSH HEAT INDEX VALUES OVER 105 DEGREES...WITH SOME INLAND AREAS EXCEEDING 110 DEGREES. HAVE ISSUED A HEAT ADVISORY FOR THE COAST AND COLUMBUS COUNTY WITH AN EXCESSIVE HEAT WARNING IN EFFECT FOR THE REMAINING INLAND COUNTIES. FRONT STALLS JUST SOUTH OF THE AREA WED MORNING THEN LIFTS BACK NORTH AS THE SEA BREEZE DEVELOPS. SURFACE BOUNDARY WILL WILL BECOME DIFFICULT TO DISTINGUISH AS THE SEA BREEZE BECOMES MORE DOMINANT. WEST TO NORTHWEST FLOW WILL EXIST FROM NEAR THE SURFACE THROUGH AT LEAST 200 MB. ALTHOUGH PRECIPITABLE WATER VALUES REMAIN ELEVATED THE FLAT MID LEVEL FLOW AND LACK OF ANY STRONG TRIGGERING MECHANISMS WILL LIMIT COVERAGE OF CONVECTION TO ABOUT 30 PERCENT. TEMPERATURES ARE AGAIN EXPECTED TO BE ABOVE CLIMO...WARMEST ACROSS SOUTHERN SC COUNTIES WHERE A HEAT ADVISORY MAY ONCE AGAIN BE NEEDED. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 PM MONDAY...MODELS CONTINUE TO SHOW LINGERING BOUNDARY AS NW FLOW FLATTENS OUT ON BOTTOM OF MID TO UPPER TROUGH OVER THE CAROLINAS. PCP WATER FIELDS SHOW BOUNDARY NICELY WITH VALUES DOWN BELOW 1.5 IN DRIER AIR TO THE NORTH HEADING INTO THURS MORNING AND HIGHER VALUES UP TO 2 INCHES TO THE SOUTH OVER SC. BUT BOUNDARY MAY BUCKLE UP AS WIND FIELDS SHOW A WEAK SFC LOW DEVELOPING OVER INLAND CAPE FEAR REGION. THIS WILL ALLOW A MORE EASTERLY FETCH TO CARRY MORE MOISTURE RICH AIR BACK INTO THE AREA ON THURS. THIS SHOULD ALSO PRODUCE A FOCAL POINT FOR CONVECTION AS SEA BREEZE ENHANCES CONVERGENCE AS A SHORTWAVE RIDES ALONG THE BASE OF THE TROUGH INTO THE COASTAL CAROLINAS. MODELS SUGGESTING LIKELY POPS ON THURS. FOR NOW...HAVE PUSHED THE POPS UP TO HIGH CHC BUT WILL WAIT FOR ANOTHER MODEL RUN TO JUMP UP ANY FURTHER. WILL KEEP WITH TREND OF GREATEST CHC OF CONVECTION SHIFTING SOUTH INTO SC ON THURS INTO FRI AS BOUNDARY LINGERS NEARBY. ONCE THIS SHORTWAVE AND LOW MOVES OUT OFF TO THE EAST ON FRI...PLENTY OF DRY AIR AND SUBSIDENCE WILL WORK ITS WAY DOWN FROM THE NORTH IN DEEP N-NW FLOW AS HIGH PRESSURE BUILDS DOWN AT THE SFC. BY FRI AFTN ANY MOISTURE SHOULD BE DISPLACED WELL SOUTH AND EAST OF LOCAL AREA LEAVING PCP WATER VALUES DOWN LESS THAN 1.5 INCHES THROUGH MUCH OF THE WEEKEND. POSSIBLE NW FLOW CONVECTIVE DEBRIS CLOUDS OR A LITTLE SHORTWAVE ENERGY LATE SUN INTO MON COULD BRING IN SOME CLOUD OR POSSIBLY PRODUCE A LOCALIZED SHWR BY SUN. FOR NOW...ONLY KEEPING LOW END SLIGHT CHC OF LOCALIZED BUILDUP ALONG SEA BREEZE OVER THE WEEKEND...MAINLY JUST INLAND OF COAST. BY SUN NIGHT INTO MONDAY... A MORE TYPICAL SUMMERTIME PATTERN SETS UP ONCE AGAIN WITH POSSIBLE SHORTWAVE OR WEAK FRONT ENHANCING SOME CONVECTION UP STREAM AND POSSIBLY ALONG PIEDMONT TROUGH INLAND. OVERALL...AFTER EARLY FRI...HEADING INTO DRIER AND SEASONABLE WEATHER WITH TEMPS CLOSE TO NORMAL. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z...EXPECT VFR THRUOUT THE FORECAST PERIOD. EXPECT VFR TO PREVAIL THIS AFTERNOON WITH DIURNAL CU AND HIGH CLOUDS AS WELL. WOULD NOT ENTIRELY RULE OUT AN ISOLATED TSRA LATE THIS AFTERNOON THROUGH MID-EVENING...THOUGH GIVEN LOW CONFIDENCE HAVE ONLY INTRODUCED VCTS AT THE INLAND TERMINALS. COULD SEE DEBRIS CONVECTIVE CLOUDS OVERNIGHT BUT FOR NOW HAVE LIMITED THEIR OCCURRENCE TO BETWEEN 15K-25K FEET. ACROSS THE COASTAL TERMS...AN ACTIVE SEA BREEZE WILL RESULT IN SSE-SSW WINDS 10-15 KT WITH GUSTS AROUND 20 KT THRU MID- LATE EVENING...EVENTUALLY SUBSIDING LATE EVENING AND OVERNIGHT HOURS. WINDS TO STAY ACTIVE OVERNIGHT...EVEN ACROSS INLAND TERMINALS...AND THUS HAVE KEPT FOG OFF THE BOOKS. AFTER DAYBREAK ON TUESDAY...EXPECT VFR WITH WSW WINDS 5 TO 10 KTS WITH THIN CI/CS. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM DIURNAL CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM MONDAY...UPDATED WINDS AND SIGNIFICANT SEAS FROM EARLIER STILL LOOKING AOK THROUGH DAYBREAK TUESDAY. NO ADDITIONAL CHANGES NEEDED AT THIS TIME. PREVIOUS........................................................... AS OF 1145 AM MONDAY...TWEAKED WINDS...MAINLY WIND SPEEDS SLIGHTLY HIER BY UP TO SEVERAL KNOTS ACROSS THE AREA WATERS FOR THE OVERNIGHT PERIOD. IN ESSENCE...THIS WILL RESULT IN THE WIND SPEEDS IN THE 15 TO OCCASIONALLY 20 KT RANGE FOR THE MAJORITY OF THE TONIGHT PERIOD. THIS WILL RESULT IN SIGNIFICANT SEAS BUILDING TO 3 TO 5 FT TONIGHT. THE PROBLEM IS WHETHER THE COMBINED 15-20 KT WINDS AND 3-5 FT SIGNIFICANT SEAS LAST LONG ENOUGH TO WARRANT A SMALL CRAFT EXERCISE CAUTION FLAG. THIS WILL BE DETERMINED AT THE NEXT UPDATE. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL MAINTAIN SOUTHWEST FLOW ACROSS THE WATERS TUE INTO TUE NIGHT. GRADIENT WILL BECOME A LITTLE MORE DEFINED LATER TUE AND TUE NIGHT WITH SPEEDS HITTING A SOLID 20 KT AT TIMES. SEAS TUE AND TUE NIGHT MAY FLIRT WITH 5 FT NEAR THE 20 NM LIMIT BUT THE BULK OF THE ZONES WILL BE 3 TO 4 FT WITH SOME 2 FT NEAR SHORE. WEAK FRONT SETTLES OVER THE AREA LATE TUE...PUSHING JUST SOUTH OF THE AREA BY DAYBREAK WED. FRONT WILL BE OBSCURED WED BY DEVELOPING SEA BREEZE...WHICH WILL RESULT IN SOUTHERLY FLOW RETURNING TO THE WATERS. GRADIENT WEAKENS FOR WED WITH SPEEDS 10 TO 15 KT. SEAS WILL DROP TO 2 TO 4 FT LATE TUE NIGHT AND REMAIN UNCHANGED THROUGH THE END OF THE PERIOD. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 PM MONDAY...LINGERING FRONTAL BOUNDARY MAY PRODUCE MORE VARIABLE WINDS ON THURS...BUT REMAINING VERY LIGHT OVERALL. SOME MODELS HINT AT A BROAD WEAK SFC LOW DEVELOPING ON THURS BUT EITHER WAY A MORE ON SHORE FLOW LESS THAN 10 KTS THURS BECOMING MORE NORTHERLY ON FRI UP TO 10 TO 15 KTS INTO THE WEEKEND AS HIGH PRESSURE BUILDS DOWN FROM THE NORTH. SEAS WILL BASICALLY REMAIN BETWEEN 2 AND 4 FT THROUGH THE PERIOD. EXPECT A SLIGHT UPTICK IN WINDS AND SEAS EACH AFTN AS SEA BREEZE DEVELOPS NEAR SHORE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...EXCESSIVE HEAT WARNING FROM NOON TO 7 PM EDT TUESDAY FOR SCZ017-023-024-032-033-039. HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ017-023-024- 032-033-039-053>056. HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR SCZ053>056. NC...EXCESSIVE HEAT WARNING FROM NOON TO 7 PM EDT TUESDAY FOR NCZ087-096. HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ087-096-099- 105>110. HEAT ADVISORY FROM NOON TO 7 PM EDT TUESDAY FOR NCZ099-105>110. MARINE...NONE. && $$ NEAR TERM...DCH SHORT TERM...III LONG TERM...RGZ AVIATION...DCH/SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
130 PM EDT MON JUL 20 2015 .SYNOPSIS...A RELATIVELY ACTIVE SUMMER PATTERN...NORTHWEST FLOW ALOFT...WILL PREVAIL ACROSS THE REGION THROUGH THE WEEK AS AN UPPER LEVEL RIDGE STRENGTHENS OVER THE CENTRAL PLAINS. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 1100 AM MONDAY... ...HEAT ADVISORY REMAINS IN EFFECT THIS AFTERNOON... LATE MORNING UPDATE WILL MAINLY SLOW DOWN THE MIXING TRENDS THIS AFTERNOON...WHICH WILL STILL RESULT IN MARGINAL HEAT INDICES TO SUPPORT THE ONGOING ADVISORY. PREVIOUS DISCUSSION... CENTRAL NC REMAINS ON THE EAST NORTHEAST PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTH-CENTRAL CONUS - AT THE SOUTHERN FRINGE OF THE WESTERLIES IN WNW FLOW ALOFT. IN SUCH A PATTERN...A VARIETY OF ADDITIONAL VARIABLES CAN INFLUENCE THE DEVELOPMENT/EVOLUTION (OR LACK THEREOF) OF CONVECTION...INCLUDING UPSTREAM CONVECTION OR THE REMNANTS THEREOF (MCV`S/OUTFLOW BOUNDARIES)...SMALL AMPLITUDE BAROCLINIC WAVES AT THE SOUTHERN FRINGE OF THE WESTERLIES...LOW-LEVEL MOISTURE ADVECTION...DEPTH/DEGREE OF MIXING...ETC. AS A RESULT...CONFIDENCE IN CONVECTIVE CHANCES/COVERAGE/TIMING THIS AFTERNOON AND EVENING IS BELOW AVERAGE. H85 TEMPS OF 18-20C AND STRONG INSOLATION/MIXING CONTINUE TO SUGGEST HIGHS IN THE MID/UPPER 90S THIS AFTERNOON. HOWEVER...CONFIDENCE IN SFC DEWPOINTS...RELATIVE HUMIDITY AND HEAT INDICES REMAINS UNCERTAIN. LOW-LEVEL THERMODYNAMIC PROFILES FCST BY THE GFS/NAM ARE CONSIDERABLY DIFFERENT FOR THIS AFTERNOON. THE NAM SUGGESTS 16-18C H85 DEWPOINTS OVER CENTRAL NC...WITH SFC DEWPOINTS RANGING FROM THE MID 60S (NW) TO ~70F (E/SE). AS A RESULT...THE NAM SUGGESTS MODERATE DESTABILIZATION AND HEAT INDICES AT/AROUND ADVISORY CRITERIA SOUTH AND EAST OF THE TRIANGLE. THE GFS INDICATES H85 DEWPOINTS ~14C... DEEPER MIXING...SFC DEWPOINTS IN THE LOWER 60S...MARGINAL INSTABILITY LARGELY CONFINED TO THE WEST/NW PIEDMONT...AND LOWER HEAT INDICES OF 100-103F SOUTH AND EAST OF THE TRIANGLE. SPC MESOANALYSIS DATA INDICATES A DRY LOW-LEVEL AIRMASS IN PLACE OVER CENTRAL NC EARLY THIS MORNING WITH H85 DEWPOINTS OF 12-15C (16-17C ALONG THE COAST AND ALONG/WEST OF THE MOUNTAINS). THOUGH WEAK WESTERLY FLOW SHOULD ALLOW BETTER LOW-LEVEL MOISTURE TO ADVECT INTO PORTIONS OF THE WEST/SW PIEDMONT THIS AFTERNOON...THE AFOREMENTIONED MESOANALYSIS DATA SUGGESTS THERMODYNAMIC PROFILES WILL BE CLOSER TO THOSE DEPICTED BY THE GFS THAN THE NAM. TWO SMALL AMPLITUDE WAVES (BAROCLINIC/MCV/OR A COMBINATION THEREOF) WERE LOCATED UPSTREAM OF THE AREA THIS MORNING...ONE IN WV AND THE OTHER ALONG THE WESTERN TN/KY BORDER. THE LATEST RAP GUIDANCE SUGGESTS THE WAVE IN WV WILL TRACK EASTWARD THROUGH CENTRAL/ NORTHERN VA LATE THIS MORNING AND EARLY THIS AFTERNOON...WHILE THE KY/TN WAVE TAKES A MORE UNCERTAIN COURSE (INTO A WEAKER FLOW REGIME) EAST SOUTHEAST ACROSS SOUTHWEST NC AND UPSTATE SC LATE THIS AFTERNOON. THE LATTER WAVE TRACKING INTO WESTERN NC/SC APPEARS MOST LIKELY TO AID CONVECTIVE DEVELOPMENT THIS AFT/EVE GIVEN EXCELLENT DIURNAL TIMING AND A TRACK WHICH TAKES IS THROUGH A MORE FAVORABLE THERMODYNAMIC ENVIRONMENT. GIVEN UNCERTAINTY IN THERMODYNAMIC PROFILES (AS MENTIONED ABOVE)...UNCERTAINTY IN THE PRECISE TRACK/TIMING OF THE AFOREMENTIONED WAVES IN ADDITION TO THE POTENTIAL CONTRIBUTION FROM MESOSCALE FORCING...WILL INDICATE A 20- 30% CHANCE OF CONVECTION...HIGHEST IN THE WEST/SW PIEDMONT AND FAR NE COASTAL PLAIN. -VINCENT && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... AS OF 430 AM MONDAY... ...HEAT ADVISORY WILL LIKELY BE NEEDED FOR PORTIONS OF CENTRAL NC... FORECAST CHALLENGES WILL BE SIMILAR TO TODAY...ALBEIT WITH A BETTER OVERALL POTENTIAL FOR CONVECTION AS THE WESTERLIES STRENGTHEN /EXTEND FURTHER SOUTH/ IN RESPONSE TO AMPLIFICATION OF AN UPPER LEVEL TROUGH OVER PORTIONS OF EASTERN CANADA...THE GREAT LAKES...AND NEW ENGLAND. LATEST GUIDANCE SUGGESTS DRY CONDITIONS FOR MOST OF THE DAY...WITH A RAPID INCREASE IN CONVECTIVE POTENTIAL AFTER 21Z AND THE BEST OVERALL POTENTIAL BETWEEN LATE AFTERNOON AND MIDNIGHT (21- 04Z). EXPECT HIGHS SIMILAR TO TODAY...ALBEIT SLIGHTLY COOLER IN THE FAR NW PIEDMONT. ANOTHER HEAT ADVISORY WILL LIKELY BE NEEDED... PERHAPS ALONG/EAST OF THE HWY 1 CORRIDOR (I.E. INCLUDING THE TRIANGLE)...DEPENDING ON LOW-LEVEL MOISTURE. -VINCENT && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 320 AM MONDAY... MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A SURFACE FRONT STALLING NEAR OR JUST TO THE SOUTH OF CENTRAL NC FROM MID TO LATE WEEK... BEFORE SHIFTING FURTHER SOUTH OVER THE WEEKEND AS A SURFACE HIGH BUILDS MORE AGGRESSIVELY IN FROM THE NORTH (AS IT SHIFTS EASTWARD AND EVENTUALLY OFFSHORE) WHILE THE MID LEVEL TROUGH AXIS OVER THE NORTHEAST PUSHES OFFSHORE. THIS SHOULD ALLOW FOR MAINLY DIURNAL CHANCES FOR SHOWERS AND STORMS FROM MID TO LATE WEEK... MAINLY ACROSS SOUTHERN PORTIONS OF THE AREA...INVOF THE FRONT... WITH GENERALLY DRY WEATHER RETURNING FOR THE WEEKEND (SMALL CHANCE OF CONVECTION ON SUNDAY... DEPENDING ON THE TIMING OF ANOTHER NORTHERN STREAM S/W TRACKING ACROSS THE NORTHERN HALF OF THE COUNTRY). HIGH TEMPS DURING THE MEDIUM RANGE SHOULD BE NEAR NORMAL... WITH HIGHS IN THE UPPER 80S TO LOWER 90S. LOW TEMPS WILL FOLLOW A SIMILAR TREND... GENERALLY UPPER 60S NORTH TO LOWER 70S SOUTH. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 130 PM MONDAY... 24-HR TAF PERIOD: EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE TAF PERIOD...ASIDE FROM A SMALL POTENTIAL FOR SHOWERS/STORMS LATE THIS AFT/EVE...PRIMARILY AT THE INT/GSO TERMINALS...THOUGH POSSIBLY AT ANY TERMINAL. GENERALLY WESTERLY WINDS ~10 KT THIS AFTERNOON WILL BECOME LIGHT AFTER SUNSET. LONG TERM: TYPICAL SUMMERY PATTERN FEATURING DIURNAL CONVECTION WILL CONTINUE INTO THE WEEKEND WITH AN UPPER RIDGE PERSISTING OVER THE CENTRAL CONUS PRODUCING NORTHWEST FLOW ALOFT DOWNSTREAM ACROSS THE APPALACHIANS AND MID-ATLANTIC. THE PRIMARY AVIATION HAZARD WILL BE LATE DAY CONVECTION...GENERALLY 18-02Z...ALTHOUGH NOCTURNAL ACTIVITY WILL BE A POSSIBILITY IF WE HAVE STRONG DOWNSTREAM CONVECTION THAT MOVES INTO THE AREA OVERNIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ011-027-028-042- 043-077-078-085-086-088-089. && $$ SYNOPSIS...VINCENT NEAR TERM...MLM/VINCENT SHORT TERM...VINCENT LONG TERM...77 AVIATION...MLM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1115 AM EDT MON JUL 20 2015 .SYNOPSIS...A RELATIVELY ACTIVE SUMMER PATTERN...NORTHWEST FLOW ALOFT...WILL PREVAIL ACROSS THE REGION THROUGH NEXT WEEKEND AS AN UPPER LEVEL RIDGE STRENGTHENS OVER THE CENTRAL PLAINS. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 1100 AM MONDAY... ...HEAT ADVISORY REMAINS IN EFFECT THIS AFTERNOON... LATE MORNING UPDATE WILL MAINLY SLOW DOWN THE MIXING TRENDS THIS AFTERNOON...WHICH WILL STILL RESULT IN MARGINAL HEAT INDICES TO SUPPORT THE ONGOING ADVISORY. PREVIOUS DISCUSSION... CENTRAL NC REMAINS ON THE EAST NORTHEAST PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTH-CENTRAL CONUS - AT THE SOUTHERN FRINGE OF THE WESTERLIES IN WNW FLOW ALOFT. IN SUCH A PATTERN...A VARIETY OF ADDITIONAL VARIABLES CAN INFLUENCE THE DEVELOPMENT/EVOLUTION (OR LACK THEREOF) OF CONVECTION...INCLUDING UPSTREAM CONVECTION OR THE REMNANTS THEREOF (MCV`S/OUTFLOW BOUNDARIES)...SMALL AMPLITUDE BAROCLINIC WAVES AT THE SOUTHERN FRINGE OF THE WESTERLIES...LOW-LEVEL MOISTURE ADVECTION...DEPTH/DEGREE OF MIXING...ETC. AS A RESULT...CONFIDENCE IN CONVECTIVE CHANCES/COVERAGE/TIMING THIS AFTERNOON AND EVENING IS BELOW AVERAGE. H85 TEMPS OF 18-20C AND STRONG INSOLATION/MIXING CONTINUE TO SUGGEST HIGHS IN THE MID/UPPER 90S THIS AFTERNOON. HOWEVER...CONFIDENCE IN SFC DEWPOINTS...RELATIVE HUMIDITY AND HEAT INDICES REMAINS UNCERTAIN. LOW-LEVEL THERMODYNAMIC PROFILES FCST BY THE GFS/NAM ARE CONSIDERABLY DIFFERENT FOR THIS AFTERNOON. THE NAM SUGGESTS 16-18C H85 DEWPOINTS OVER CENTRAL NC...WITH SFC DEWPOINTS RANGING FROM THE MID 60S (NW) TO ~70F (E/SE). AS A RESULT...THE NAM SUGGESTS MODERATE DESTABILIZATION AND HEAT INDICES AT/AROUND ADVISORY CRITERIA SOUTH AND EAST OF THE TRIANGLE. THE GFS INDICATES H85 DEWPOINTS ~14C... DEEPER MIXING...SFC DEWPOINTS IN THE LOWER 60S...MARGINAL INSTABILITY LARGELY CONFINED TO THE WEST/NW PIEDMONT...AND LOWER HEAT INDICES OF 100-103F SOUTH AND EAST OF THE TRIANGLE. SPC MESOANALYSIS DATA INDICATES A DRY LOW-LEVEL AIRMASS IN PLACE OVER CENTRAL NC EARLY THIS MORNING WITH H85 DEWPOINTS OF 12-15C (16-17C ALONG THE COAST AND ALONG/WEST OF THE MOUNTAINS). THOUGH WEAK WESTERLY FLOW SHOULD ALLOW BETTER LOW-LEVEL MOISTURE TO ADVECT INTO PORTIONS OF THE WEST/SW PIEDMONT THIS AFTERNOON...THE AFOREMENTIONED MESOANALYSIS DATA SUGGESTS THERMODYNAMIC PROFILES WILL BE CLOSER TO THOSE DEPICTED BY THE GFS THAN THE NAM. TWO SMALL AMPLITUDE WAVES (BAROCLINIC/MCV/OR A COMBINATION THEREOF) WERE LOCATED UPSTREAM OF THE AREA THIS MORNING...ONE IN WV AND THE OTHER ALONG THE WESTERN TN/KY BORDER. THE LATEST RAP GUIDANCE SUGGESTS THE WAVE IN WV WILL TRACK EASTWARD THROUGH CENTRAL/ NORTHERN VA LATE THIS MORNING AND EARLY THIS AFTERNOON...WHILE THE KY/TN WAVE TAKES A MORE UNCERTAIN COURSE (INTO A WEAKER FLOW REGIME) EAST SOUTHEAST ACROSS SOUTHWEST NC AND UPSTATE SC LATE THIS AFTERNOON. THE LATTER WAVE TRACKING INTO WESTERN NC/SC APPEARS MOST LIKELY TO AID CONVECTIVE DEVELOPMENT THIS AFT/EVE GIVEN EXCELLENT DIURNAL TIMING AND A TRACK WHICH TAKES IS THROUGH A MORE FAVORABLE THERMODYNAMIC ENVIRONMENT. GIVEN UNCERTAINTY IN THERMODYNAMIC PROFILES (AS MENTIONED ABOVE)...UNCERTAINTY IN THE PRECISE TRACK/TIMING OF THE AFOREMENTIONED WAVES IN ADDITION TO THE POTENTIAL CONTRIBUTION FROM MESOSCALE FORCING...WILL INDICATE A 20- 30% CHANCE OF CONVECTION...HIGHEST IN THE WEST/SW PIEDMONT AND FAR NE COASTAL PLAIN. -VINCENT && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... AS OF 430 AM MONDAY... ...HEAT ADVISORY WILL LIKELY BE NEEDED FOR PORTIONS OF CENTRAL NC... FORECAST CHALLENGES WILL BE SIMILAR TO TODAY...ALBEIT WITH A BETTER OVERALL POTENTIAL FOR CONVECTION AS THE WESTERLIES STRENGTHEN /EXTEND FURTHER SOUTH/ IN RESPONSE TO AMPLIFICATION OF AN UPPER LEVEL TROUGH OVER PORTIONS OF EASTERN CANADA...THE GREAT LAKES...AND NEW ENGLAND. LATEST GUIDANCE SUGGESTS DRY CONDITIONS FOR MOST OF THE DAY...WITH A RAPID INCREASE IN CONVECTIVE POTENTIAL AFTER 21Z AND THE BEST OVERALL POTENTIAL BETWEEN LATE AFTERNOON AND MIDNIGHT (21- 04Z). EXPECT HIGHS SIMILAR TO TODAY...ALBEIT SLIGHTLY COOLER IN THE FAR NW PIEDMONT. ANOTHER HEAT ADVISORY WILL LIKELY BE NEEDED... PERHAPS ALONG/EAST OF THE HWY 1 CORRIDOR (I.E. INCLUDING THE TRIANGLE)...DEPENDING ON LOW-LEVEL MOISTURE. -VINCENT && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 320 AM MONDAY... MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A SURFACE FRONT STALLING NEAR OR JUST TO THE SOUTH OF CENTRAL NC FROM MID TO LATE WEEK... BEFORE SHIFTING FURTHER SOUTH OVER THE WEEKEND AS A SURFACE HIGH BUILDS MORE AGGRESSIVELY IN FROM THE NORTH (AS IT SHIFTS EASTWARD AND EVENTUALLY OFFSHORE) WHILE THE MID LEVEL TROUGH AXIS OVER THE NORTHEAST PUSHES OFFSHORE. THIS SHOULD ALLOW FOR MAINLY DIURNAL CHANCES FOR SHOWERS AND STORMS FROM MID TO LATE WEEK... MAINLY ACROSS SOUTHERN PORTIONS OF THE AREA...INVOF THE FRONT... WITH GENERALLY DRY WEATHER RETURNING FOR THE WEEKEND (SMALL CHANCE OF CONVECTION ON SUNDAY... DEPENDING ON THE TIMING OF ANOTHER NORTHERN STREAM S/W TRACKING ACROSS THE NORTHERN HALF OF THE COUNTRY). HIGH TEMPS DURING THE MEDIUM RANGE SHOULD BE NEAR NORMAL... WITH HIGHS IN THE UPPER 80S TO LOWER 90S. LOW TEMPS WILL FOLLOW A SIMILAR TREND... GENERALLY UPPER 60S NORTH TO LOWER 70S SOUTH. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 800 AM MONDAY... 24-HR TAF PERIOD: EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE MAJORITY OF THE TAF PERIOD...ASIDE FROM A SMALL POTENTIAL FOR SHOWERS/STORMS LATE THIS AFT/EVE...PRIMARILY AT THE INT/GSO TERMINALS...THOUGH POSSIBLY AT ANY TERMINAL (SEE NEAR TERM DISCUSSION). EXPECT LIGHT/VARIABLE OR CALM WINDS TO BECOME WESTERLY AT ~10 KT THIS AFTERNOON...THEN WEAKENING TO 5 KT OR LESS BY MIDNIGHT. LONG TERM: WITH AN UPPER LEVEL RIDGE EXPECTED TO PERSIST OVER THE CENTRAL CONUS AND AN EXTENDED PERIOD OF NW FLOW ALOFT DOWNSTREAM ACROSS THE APPALACHIANS AND MID-ATLANTIC...EXPECT AN ACTIVE SUMMER- TIME PATTERN TO PERSIST ACROSS THE REGION...WITH THE PRIMARY AVIATION HAZARD ASSOCIATED WITH DIURNAL CONVECTION...THOUGH NOCTURNAL CONVECTION CANNOT BE RULED OUT AT TIMES. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ011-027-028-042- 043-077-078-085-086-088-089. && $$ SYNOPSIS...VINCENT NEAR TERM...MLM/VINCENT SHORT TERM...VINCENT LONG TERM...77 AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
803 AM EDT MON JUL 20 2015 .SYNOPSIS...A RELATIVELY ACTIVE SUMMER PATTERN...NORTHWEST FLOW ALOFT...WILL PREVAIL ACROSS THE REGION THROUGH NEXT WEEKEND AS AN UPPER LEVEL RIDGE STRENGTHENS OVER THE CENTRAL PLAINS. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 400 AM MONDAY... ...HEAT ADVISORY REMAINS IN EFFECT THIS AFTERNOON... CENTRAL NC REMAINS ON THE EAST NORTHEAST PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTH-CENTRAL CONUS - AT THE SOUTHERN FRINGE OF THE WESTERLIES IN WNW FLOW ALOFT. IN SUCH A PATTERN...A VARIETY OF ADDITIONAL VARIABLES CAN INFLUENCE THE DEVELOPMENT/EVOLUTION (OR LACK THEREOF) OF CONVECTION...INCLUDING UPSTREAM CONVECTION OR THE REMNANTS THEREOF (MCV`S/OUTFLOW BOUNDARIES)...SMALL AMPLITUDE BAROCLINIC WAVES AT THE SOUTHERN FRINGE OF THE WESTERLIES...LOW- LEVEL MOISTURE ADVECTION...DEPTH/DEGREE OF MIXING...ETC. AS A RESULT...CONFIDENCE IN CONVECTIVE CHANCES/COVERAGE/TIMING THIS AFTERNOON AND EVENING IS BELOW AVERAGE. H85 TEMPS OF 18-20C AND STRONG INSOLATION/MIXING CONTINUE TO SUGGEST HIGHS IN THE MID/UPPER 90S THIS AFTERNOON. HOWEVER...CONFIDENCE IN SFC DEWPOINTS...RELATIVE HUMIDITY AND HEAT INDICES REMAINS UNCERTAIN. LOW-LEVEL THERMODYNAMIC PROFILES FCST BY THE GFS/NAM ARE CONSIDERABLY DIFFERENT FOR THIS AFTERNOON. THE NAM SUGGESTS 16-18C H85 DEWPOINTS OVER CENTRAL NC...WITH SFC DEWPOINTS RANGING FROM THE MID 60S (NW) TO ~70F (E/SE). AS A RESULT...THE NAM SUGGESTS MODERATE DESTABILIZATION AND HEAT INDICES AT/AROUND ADVISORY CRITERIA SOUTH AND EAST OF THE TRIANGLE. THE GFS INDICATES H85 DEWPOINTS ~14C... DEEPER MIXING...SFC DEWPOINTS IN THE LOWER 60S...MARGINAL INSTABILITY LARGELY CONFINED TO THE WEST/NW PIEDMONT...AND LOWER HEAT INDICES OF 100-103F SOUTH AND EAST OF THE TRIANGLE. SPC MESOANALYSIS DATA INDICATES A DRY LOW-LEVEL AIRMASS IN PLACE OVER CENTRAL NC EARLY THIS MORNING WITH H85 DEWPOINTS OF 12-15C (16-17C ALONG THE COAST AND ALONG/WEST OF THE MOUNTAINS). THOUGH WEAK WESTERLY FLOW SHOULD ALLOW BETTER LOW-LEVEL MOISTURE TO ADVECT INTO PORTIONS OF THE WEST/SW PIEDMONT THIS AFTERNOON...THE AFOREMENTIONED MESOANALYSIS DATA SUGGESTS THERMODYNAMIC PROFILES WILL BE CLOSER TO THOSE DEPICTED BY THE GFS THAN THE NAM. TWO SMALL AMPLITUDE WAVES (BAROCLINIC/MCV/OR A COMBINATION THEREOF) WERE LOCATED UPSTREAM OF THE AREA THIS MORNING...ONE IN WV AND THE OTHER ALONG THE WESTERN TN/KY BORDER. THE LATEST RAP GUIDANCE SUGGESTS THE WAVE IN WV WILL TRACK EASTWARD THROUGH CENTRAL/ NORTHERN VA LATE THIS MORNING AND EARLY THIS AFTERNOON...WHILE THE KY/TN WAVE TAKES A MORE UNCERTAIN COURSE (INTO A WEAKER FLOW REGIME) EAST SOUTHEAST ACROSS SOUTHWEST NC AND UPSTATE SC LATE THIS AFTERNOON. THE LATTER WAVE TRACKING INTO WESTERN NC/SC APPEARS MOST LIKELY TO AID CONVECTIVE DEVELOPMENT THIS AFT/EVE GIVEN EXCELLENT DIURNAL TIMING AND A TRACK WHICH TAKES IS THROUGH A MORE FAVORABLE THERMODYNAMIC ENVIRONMENT. GIVEN UNCERTAINTY IN THERMODYNAMIC PROFILES (AS MENTIONED ABOVE)...UNCERTAINTY IN THE PRECISE TRACK/TIMING OF THE AFOREMENTIONED WAVES IN ADDITION TO THE POTENTIAL CONTRIBUTION FROM MESOSCALE FORCING...WILL INDICATE A 20- 30% CHANCE OF CONVECTION...HIGHEST IN THE WEST/SW PIEDMONT AND FAR NE COASTAL PLAIN. -VINCENT && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... AS OF 430 AM MONDAY... ...HEAT ADVISORY WILL LIKELY BE NEEDED FOR PORTIONS OF CENTRAL NC... FORECAST CHALLENGES WILL BE SIMILAR TO TODAY...ALBEIT WITH A BETTER OVERALL POTENTIAL FOR CONVECTION AS THE WESTERLIES STRENGTHEN /EXTEND FURTHER SOUTH/ IN RESPONSE TO AMPLIFICATION OF AN UPPER LEVEL TROUGH OVER PORTIONS OF EASTERN CANADA...THE GREAT LAKES...AND NEW ENGLAND. LATEST GUIDANCE SUGGESTS DRY CONDITIONS FOR MOST OF THE DAY...WITH A RAPID INCREASE IN CONVECTIVE POTENTIAL AFTER 21Z AND THE BEST OVERALL POTENTIAL BETWEEN LATE AFTERNOON AND MIDNIGHT (21- 04Z). EXPECT HIGHS SIMILAR TO TODAY...ALBEIT SLIGHTLY COOLER IN THE FAR NW PIEDMONT. ANOTHER HEAT ADVISORY WILL LIKELY BE NEEDED... PERHAPS ALONG/EAST OF THE HWY 1 CORRIDOR (I.E. INCLUDING THE TRIANGLE)...DEPENDING ON LOW-LEVEL MOISTURE. -VINCENT && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 320 AM MONDAY... MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A SURFACE FRONT STALLING NEAR OR JUST TO THE SOUTH OF CENTRAL NC FROM MID TO LATE WEEK... BEFORE SHIFTING FURTHER SOUTH OVER THE WEEKEND AS A SURFACE HIGH BUILDS MORE AGGRESSIVELY IN FROM THE NORTH (AS IT SHIFTS EASTWARD AND EVENTUALLY OFFSHORE) WHILE THE MID LEVEL TROUGH AXIS OVER THE NORTHEAST PUSHES OFFSHORE. THIS SHOULD ALLOW FOR MAINLY DIURNAL CHANCES FOR SHOWERS AND STORMS FROM MID TO LATE WEEK... MAINLY ACROSS SOUTHERN PORTIONS OF THE AREA...INVOF THE FRONT... WITH GENERALLY DRY WEATHER RETURNING FOR THE WEEKEND (SMALL CHANCE OF CONVECTION ON SUNDAY... DEPENDING ON THE TIMING OF ANOTHER NORTHERN STREAM S/W TRACKING ACROSS THE NORTHERN HALF OF THE COUNTRY). HIGH TEMPS DURING THE MEDIUM RANGE SHOULD BE NEAR NORMAL... WITH HIGHS IN THE UPPER 80S TO LOWER 90S. LOW TEMPS WILL FOLLOW A SIMILAR TREND... GENERALLY UPPER 60S NORTH TO LOWER 70S SOUTH. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 800 AM MONDAY... 24-HR TAF PERIOD: EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE MAJORITY OF THE TAF PERIOD...ASIDE FROM A SMALL POTENTIAL FOR SHOWERS/STORMS LATE THIS AFT/EVE...PRIMARILY AT THE INT/GSO TERMINALS...THOUGH POSSIBLY AT ANY TERMINAL (SEE NEAR TERM DISCUSSION). EXPECT LIGHT/VARIABLE OR CALM WINDS TO BECOME WESTERLY AT ~10 KT THIS AFTERNOON...THEN WEAKENING TO 5 KT OR LESS BY MIDNIGHT. LONG TERM: WITH AN UPPER LEVEL RIDGE EXPECTED TO PERSIST OVER THE CENTRAL CONUS AND AN EXTENDED PERIOD OF NW FLOW ALOFT DOWNSTREAM ACROSS THE APPALACHIANS AND MID-ATLANTIC...EXPECT AN ACTIVE SUMMER- TIME PATTERN TO PERSIST ACROSS THE REGION...WITH THE PRIMARY AVIATION HAZARD ASSOCIATED WITH DIURNAL CONVECTION...THOUGH NOCTURNAL CONVECTION CANNOT BE RULED OUT AT TIMES. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ011-027-028-042- 043-077-078-085-086-088-089. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...VINCENT LONG TERM...77 AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
511 AM EDT MON JUL 20 2015 .SYNOPSIS...A RELATIVELY ACTIVE SUMMER PATTERN...NORTHWEST FLOW ALOFT...WILL PREVAIL ACROSS THE REGION THROUGH NEXT WEEKEND AS AN UPPER LEVEL RIDGE STRENGTHENS OVER THE CENTRAL PLAINS. && .NEAR TERM /TODAY AND TONIGHT/... AS OF 400 AM MONDAY... ...HEAT ADVISORY REMAINS IN EFFECT THIS AFTERNOON... CENTRAL NC REMAINS ON THE EAST NORTHEAST PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED OVER THE SOUTH-CENTRAL CONUS - AT THE SOUTHERN FRINGE OF THE WESTERLIES IN WNW FLOW ALOFT. IN SUCH A PATTERN...A VARIETY OF ADDITIONAL VARIABLES CAN INFLUENCE THE DEVELOPMENT/EVOLUTION (OR LACK THEREOF) OF CONVECTION...INCLUDING UPSTREAM CONVECTION OR THE REMNANTS THEREOF (MCV`S/OUTFLOW BOUNDARIES)...SMALL AMPLITUDE BAROCLINIC WAVES AT THE SOUTHERN FRINGE OF THE WESTERLIES...LOW- LEVEL MOISTURE ADVECTION...DEPTH/DEGREE OF MIXING...ETC. AS A RESULT...CONFIDENCE IN CONVECTIVE CHANCES/COVERAGE/TIMING THIS AFTERNOON AND EVENING IS BELOW AVERAGE. H85 TEMPS OF 18-20C AND STRONG INSOLATION/MIXING CONTINUE TO SUGGEST HIGHS IN THE MID/UPPER 90S THIS AFTERNOON. HOWEVER...CONFIDENCE IN SFC DEWPOINTS...RELATIVE HUMIDITY AND HEAT INDICES REMAINS UNCERTAIN. LOW-LEVEL THERMODYNAMIC PROFILES FCST BY THE GFS/NAM ARE CONSIDERABLY DIFFERENT FOR THIS AFTERNOON. THE NAM SUGGESTS 16-18C H85 DEWPOINTS OVER CENTRAL NC...WITH SFC DEWPOINTS RANGING FROM THE MID 60S (NW) TO ~70F (E/SE). AS A RESULT...THE NAM SUGGESTS MODERATE DESTABILIZATION AND HEAT INDICES AT/AROUND ADVISORY CRITERIA SOUTH AND EAST OF THE TRIANGLE. THE GFS INDICATES H85 DEWPOINTS ~14C... DEEPER MIXING...SFC DEWPOINTS IN THE LOWER 60S...MARGINAL INSTABILITY LARGELY CONFINED TO THE WEST/NW PIEDMONT...AND LOWER HEAT INDICES OF 100-103F SOUTH AND EAST OF THE TRIANGLE. SPC MESOANALYSIS DATA INDICATES A DRY LOW-LEVEL AIRMASS IN PLACE OVER CENTRAL NC EARLY THIS MORNING WITH H85 DEWPOINTS OF 12-15C (16-17C ALONG THE COAST AND ALONG/WEST OF THE MOUNTAINS). THOUGH WEAK WESTERLY FLOW SHOULD ALLOW BETTER LOW-LEVEL MOISTURE TO ADVECT INTO PORTIONS OF THE WEST/SW PIEDMONT THIS AFTERNOON...THE AFOREMENTIONED MESOANALYSIS DATA SUGGESTS THERMODYNAMIC PROFILES WILL BE CLOSER TO THOSE DEPICTED BY THE GFS THAN THE NAM. TWO SMALL AMPLITUDE WAVES (BAROCLINIC/MCV/OR A COMBINATION THEREOF) WERE LOCATED UPSTREAM OF THE AREA THIS MORNING...ONE IN WV AND THE OTHER ALONG THE WESTERN TN/KY BORDER. THE LATEST RAP GUIDANCE SUGGESTS THE WAVE IN WV WILL TRACK EASTWARD THROUGH CENTRAL/ NORTHERN VA LATE THIS MORNING AND EARLY THIS AFTERNOON...WHILE THE KY/TN WAVE TAKES A MORE UNCERTAIN COURSE (INTO A WEAKER FLOW REGIME) EAST SOUTHEAST ACROSS SOUTHWEST NC AND UPSTATE SC LATE THIS AFTERNOON. THE LATTER WAVE TRACKING INTO WESTERN NC/SC APPEARS MOST LIKELY TO AID CONVECTIVE DEVELOPMENT THIS AFT/EVE GIVEN EXCELLENT DIURNAL TIMING AND A TRACK WHICH TAKES IS THROUGH A MORE FAVORABLE THERMODYNAMIC ENVIRONMENT. GIVEN UNCERTAINTY IN THERMODYNAMIC PROFILES (AS MENTIONED ABOVE)...UNCERTAINTY IN THE PRECISE TRACK/TIMING OF THE AFOREMENTIONED WAVES IN ADDITION TO THE POTENTIAL CONTRIBUTION FROM MESOSCALE FORCING...WILL INDICATE A 20- 30% CHANCE OF CONVECTION...HIGHEST IN THE WEST/SW PIEDMONT AND FAR NE COASTAL PLAIN. -VINCENT && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... AS OF 430 AM MONDAY... ...HEAT ADVISORY WILL LIKELY BE NEEDED FOR PORTIONS OF CENTRAL NC... FORECAST CHALLENGES WILL BE SIMILAR TO TODAY...ALBEIT WITH A BETTER OVERALL POTENTIAL FOR CONVECTION AS THE WESTERLIES STRENGTHEN /EXTEND FURTHER SOUTH/ IN RESPONSE TO AMPLIFICATION OF AN UPPER LEVEL TROUGH OVER PORTIONS OF EASTERN CANADA...THE GREAT LAKES...AND NEW ENGLAND. LATEST GUIDANCE SUGGESTS DRY CONDITIONS FOR MOST OF THE DAY...WITH A RAPID INCREASE IN CONVECTIVE POTENTIAL AFTER 21Z AND THE BEST OVERALL POTENTIAL BETWEEN LATE AFTERNOON AND MIDNIGHT (21- 04Z). EXPECT HIGHS SIMILAR TO TODAY...ALBEIT SLIGHTLY COOLER IN THE FAR NW PIEDMONT. ANOTHER HEAT ADVISORY WILL LIKELY BE NEEDED... PERHAPS ALONG/EAST OF THE HWY 1 CORRIDOR (I.E. INCLUDING THE TRIANGLE)...DEPENDING ON LOW-LEVEL MOISTURE. -VINCENT && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 320 AM MONDAY... MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A SURFACE FRONT STALLING NEAR OR JUST TO THE SOUTH OF CENTRAL NC FROM MID TO LATE WEEK... BEFORE SHIFTING FURTHER SOUTH OVER THE WEEKEND AS A SURFACE HIGH BUILDS MORE AGGRESSIVELY IN FROM THE NORTH (AS IT SHIFTS EASTWARD AND EVENTUALLY OFFSHORE) WHILE THE MID LEVEL TROUGH AXIS OVER THE NORTHEAST PUSHES OFFSHORE. THIS SHOULD ALLOW FOR MAINLY DIURNAL CHANCES FOR SHOWERS AND STORMS FROM MID TO LATE WEEK... MAINLY ACROSS SOUTHERN PORTIONS OF THE AREA...INVOF THE FRONT... WITH GENERALLY DRY WEATHER RETURNING FOR THE WEEKEND (SMALL CHANCE OF CONVECTION ON SUNDAY... DEPENDING ON THE TIMING OF ANOTHER NORTHERN STREAM S/W TRACKING ACROSS THE NORTHERN HALF OF THE COUNTRY). HIGH TEMPS DURING THE MEDIUM RANGE SHOULD BE NEAR NORMAL... WITH HIGHS IN THE UPPER 80S TO LOWER 90S. LOW TEMPS WILL FOLLOW A SIMILAR TREND... GENERALLY UPPER 60S NORTH TO LOWER 70S SOUTH. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 230 AM MONDAY... 24-HR TAF PERIOD: EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE MAJORITY OF THE TAF PERIOD...ASIDE FROM A SMALL POTENTIAL FOR SHOWERS/STORMS LATE THIS AFT/EVE...PRIMARILY AT THE INT/GSO TERMINALS...THOUGH POSSIBLY AT ANY TERMINAL (SEE NEAR TERM DISCUSSION). EXPECT LIGHT/VARIABLE OR CALM WINDS TO BECOME WESTERLY AT ~10 KT THIS AFTERNOON. LONG TERM: WITH AN UPPER LEVEL RIDGE EXPECTED TO PERSIST OVER THE CENTRAL CONUS AND AN EXTENDED PERIOD OF NW FLOW ALOFT DOWNSTREAM ACROSS THE APPALACHIANS AND MID-ATLANTIC...EXPECT AN ACTIVE SUMMER- TIME PATTERN TO PERSIST ACROSS THE REGION...WITH THE PRIMARY AVIATION HAZARD ASSOCIATED WITH DIURNAL CONVECTION...THOUGH NOCTURNAL CONVECTION CANNOT BE RULED OUT AT TIMES. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ011-027-028-042- 043-077-078-085-086-088-089. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT SHORT TERM...VINCENT LONG TERM...77 AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1235 AM EDT MON JUL 20 2015 .SYNOPSIS... HIGH HEAT AND HUMIDITY WILL CONTINUE THROUGH TUESDAY. ON WEDNESDAY A COLD FRONT WILL ENTER THE AREA AND STALL FOR A FEW DAYS BRINGING A BETTER COVERAGE OF SHOWERS AND THUNDERSTORMS AND A BREAK FROM THE HEAT. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1230 AM MONDAY...CONVECTION DIED 1-2 HOURS AGO AND THE REMNANT MID AND UPPER LEVEL MOISTURE IS JUST ABOUT DONE RAINING ITSELF OUT NOW. POPS HAVE BEEN REMOVED FOR THE REMAINDER OF THE NIGHT...AND DEBRIS CLOUDINESS SHOULD ALSO DISSIPATE IN THE 2-4 AM TIMEFRAME. WINDS ARE OVERALL LIGHTER THAN MODELS INDICATED LIKELY DUE TO INTERFERENCE FROM THE SOUTHWARD MOVING CONVECTION EARLIER IN THE NIGHT. IS THE SURFACE INVERSION WELL ENOUGH ESTABLISHED TO RESIST THE MODEST LOW LEVEL JET THAT WOULD TRY TO ADD SOME MOMENTUM BACK INTO THE BOUNDARY LAYER? I`M BETTING THE INVERSION WILL WIN WITH LIGHT WINDS CONTINUING THROUGH DAYBREAK. I HAVE LOWERED LOW TEMP FORECASTS BY 1-2 DEGREES AT MOST INLAND SITES WITH LITTLE CHANGE NECESSARY ALONG THE COAST. DISCUSSION FROM 1030 PM FOLLOWS... CLOUD TOPS ARE WARMING ON INFRARED SATELLITE IMAGERY AND THERE IS NO LONGER ANY CLOUD TO GROUND OR EVEN IN CLOUD LIGHTNING NOTED IN THE AREA. AND ALTHOUGH THIS TOOK TWO HOURS LONGER TO BE TRUE WHEN COMPARED TO YESTERDAY THERE IS NO UPSTREAM CONVECTION ASSOC WITH THE NEXT SHORTWAVE. THUS FEEL THAT LOCAL HI RES MODELS LIKE THE HRRR ARE CORRECT IN KEEPING US RAIN-FREE FOR THE REST OF THE PERIOD. THE 00Z OPERATIONAL WRF HAS COME IN GIVING SUPPORT TO THIS IDEA AS WELL IN CONTRAST WITH ITS EARLIER RUN THAT HELD ON TO SOME LIGHT RAIN SHOWERS INTO AT LEAST PART OF THE OVERNIGHT. THE REMAINDER OF THE NIGHT WILL FEATURE RAIN OVER NWRN COUNTIES TIL ABOUT MIDNIGHT FOLLOWED BY A THINNING VEIL OF DEBRIS CIRRUS. ANY FOG THAT DEVELOPS IN AREAS THAT SEE RAIN WILL ONLY BE OF THE VARIETY OF CONCERN TO AVIATION/FIRE WEATHER. DEWPOINTS IN THE LOW TO MID 70S WILL APPROXIMATE THE MUGGY NIGHTTIME LOW TEMPERATURES. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 PM SUNDAY...THE REGION WILL SPEND ONE LAST DAY ON THE PERIPHERY OF A 5H RIDGE CENTERED OVER TX ON MON. TUE A 5H LOW OVER EASTERN CANADA WILL EXPAND SOUTH...SUPPRESSING THE SOUTHERN CONUS 5H RIDGE. ALTHOUGH DEEP WEST TO NORTHWEST FLOW REMAINS IN PLACE THROUGH THE PERIOD THE COMBINATION OF DEEP MOISTURE...PRECIPITABLE WATER IS AROUND 2 INCHES EACH AFTERNOON...AND THE PIEDMONT TROUGH/SEA BREEZE SHOULD GENERATE SOME ISOLATED AFTERNOON CONVECTION. GFS AND NAM SHOW A WEAK SHORTWAVE PASSING EACH DAY...BUT TIMING IS A LITTLE TOO EARLY BOTH MON AND TUE MEANING LIMITED DIURNAL INSTABILITY. SUBSIDENCE AS THE WAVE IS EXITING WILL WORK TO OFFSET CONVECTION DUE TO DIURNAL HEATING AND SURFACE BOUNDARIES. STILL THINK SOME CONVECTION WILL DEVELOP EACH AFTERNOON BUT COVERAGE WILL BE LIMITED TO SLIGHT CHC TO LOW CHC AT BEST. ORGANIZED SEVERE IS HIGHLY UNLIKELY GIVEN THE LACK OF ANY STRONG FEATURES BUT AN ISOLATED STRONG TO SEVERE STORM REMAINS A POSSIBILITY. BEST PRECIP CHANCES MAY BE AT THE END OF THE PERIOD...AHEAD OF WEAKENING COLD FRONT DROPPING IN FROM THE NORTHWEST. ALTHOUGH THE FRONT WILL BE ARRIVING LATE TUE NIGHT THERE WILL BE PLENTY OF MOISTURE AHEAD OF THE BOUNDARY AND AT LEAST SOME LINGERING INSTABILITY. DO NOT THINK WIDESPREAD PRECIP WILL DEVELOP BUT THINK CHC POP IS WARRANTED TUE NIGHT...ESPECIALLY INLAND. TEMPERATURES WILL REMAIN ABOVE CLIMO THROUGH TUE NIGHT. HIGHS WILL BE IN THE MID TO UPPER 90S EACH AFTERNOON AWAY FROM THE PINNED SEA BREEZE. COMBINATION OF DEEPER MOISTURE AND THE HEAT WILL RESULT IN HEAT INDEX VALUES IN THE 105 TO 109 RANGE MON WITH POTENTIALLY HIGHER VALUES IN PLACES ON TUE. BASED ON THE EXPECTED HEAT INDEX VALUES MON HAVE ISSUED A HEAT ADVISORY FOR ALL ZONES...EVEN THE COASTAL ZONES GIVEN THE EXPECTED LIMITED INLAND PENETRATION OF THE SEA BREEZE. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 3 PM SUNDAY...AN EAST TO WEST FLATTER MID TO UPPER RIDGE OVER THE SOUTH WILL BECOME MORE AMPLIFIED UP THE THROUGH THE MIDWEST THROUGH MID TO LATE WEEK ALLOWING TROUGH TO DIG DOWN ALONG THE EAST COAST. THEREFORE...A GENERAL WESTERLY FLOW ALOFT WED INTO THURS WILL BEGIN TO VEER ON FRI BECOMING MORE N-NW BY FRI NIGHT INTO SATURDAY. THE LATEST MODEL RUNS SHOW A WEAK FRONT PUSHING SOUTHEAST THROUGH WED LEAVING AN AREA OF LOW PRESSURE AND TROUGH LINGERING OVER OR JUST SOUTH OF AREA THURS INTO FRIDAY. BY SATURDAY THE MID TO UPPER RIDGE BUILDS FAR ENOUGH TO THE NORTH NORTHEAST INTO THE GREAT LAKES KEEPING MORE OF A DRIER NORTHERLY FLOW ALOFT AND BETTER SUBSIDENCE AND DRY AIR THROUGH THE MID TO UPPER LEVELS TO KEEP MOST CONVECTION AT BAY. THEREFORE WILL SHOW GREATEST POPS COASTAL ON WED AS SEA BREEZE COMES AGAINST NW FLOW BEHIND FRONT TO PRODUCE GREATEST CONVERGENCE CLOSER TO THE COAST...THEN SHIFTING SOUTH INTO SC ON THURS INTO FRI AS BOUNDARY LINGERS NEARBY. THEN DRIER AND RELATIVELY COOLER TEMPS BY NEXT WEEKEND AS MID TO UPPER TROUGH DIGS DOWN AND TROUGH AXIS SHIFTS OFF SHORE ALLOWING A DEEP N-NW FLOW TO SET UP. IF RIDGE DOES NOT BUILD NORTHEAST INTO THE GREAT LAKES FAR ENOUGH AND WINDS STAY MORE NW INSTEAD OF NORTHERLY ALOFT...THERE WILL BE A GREATER CHC OF UPSTREAM CONVECTION/MCS OR SHORTWAVE ENERGY MAKING ITS WAY INTO THE AREA LATE SAT INTO SUNDAY. AS FOR TEMPS...WED WILL BEGIN THE END OF DANGEROUS HEAT AS LOW LEVEL WINDS VEER AROUND WITH 850 TEMPS DOWN TO 18C BY WED AFTN AND REMAINING AROUND THAT VALUE THROUGH THE WEEKEND. THE GRADIENT OF DRIER VS MOISTER AIR WILL RUN MORE N-NW TO S-SE WITH PCP WATER VALUES DROPPING DOWN CLOSER TO AN INCH OVER CENTRAL TO NORTHERN NC AND REMAINING UP TO 2 INCHES OVER CENTRAL TO COASTAL SC ON WED SOUTH OF FRONTAL BOUNDARY/TROUGH. THE SFC DEWPOINTS MAY NOT SEE AS GREAT A CHANGE DEPENDING ON HOW FAR SOUTH THE SFC BOUNDARY ACTUALLY MAKES IT. GFS SHOWS LOWER SFC DEWPOINTS BY WED INTO THURS MOVING INTO AREA FROM THE NORTH BUT ECMWF SHOWS A GREATER CHANGE FOR NEXT WEEKEND. OVERALL EXPECT TEMPS BACK DOWN CLOSER TO NORMAL VALUES OR POSSIBLY BELOW WITH CLOUDS AND CONVECTION AFFECTING TEMPS AND POSSIBLE DRIER AIR MOVING SOUTH INTO AREA. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 06Z...PATCHY LIGHT RAIN HAS DISSIPATED. WINDS THROUGH SUNRISE BE VARIABLE...EXCEPT AT THE COASTAL TERMINALS WHERE WINDS WILL BE SW AROUND 4 KT. BR WILL DEVELOP WITH HIGHEST CONFIDENCE OF TEMPO IFR AT KFLO/KLBT DUE TO MOIST SOILS FROM YESTERDAYS ACTIVITY. TEMPO MVFR CAN BE EXPECTED AT THE COASTAL TERMINALS ALTHOUGH CONFIDENCE IS NOT AS HIGH. AFTER SUNRISE VFR EXPECTED WITH LIGHT WEST WINDS. THE SEA BREEZE MOVES THROUGH THE COASTAL TERMINALS BY LATE MORNING SHIFTING WINDS TO THE SSW...BUT WESTERLY WINDS ALOFT COULD DELAY PASSAGE TO MID AFTERNOON. EXTENDED OUTLOOK...BRIEF MVFR POSSIBLE THROUGH THE PERIOD FROM DIURNAL CONVECTION. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1230 AM MONDAY...WINDS NEAR THE BEACHES HAVE DROPPED TO LESS THAN 10 KNOTS WHILE OUT AT THE FRYING PAN SHOALS BUOY WINDS ARE BARELY REACHING 15 KNOTS. THIS IS LIGHTER THAN MOST OF THE SYNOPTIC SCALE GUIDANCE INDICATES...BUT IS RIGHT IN LINE WITH THE LATEST RUC AND HRRR OUTPUT. I HAVE REDUCED FORECAST WIND SPEEDS THROUGH THE REST OF THE NIGHT WITH ATTENDANT REDUCTIONS IN SEA HEIGHT FORECASTS AS WELL. LATEST BUOYS CLUSTERED NEAR CAPE FEAR SHOW NOTHING HIGHER THAN ABOUT 3 FEET. DISCUSSION FROM 1030 PM FOLLOWS... OUTFLOW FROM DYING CONVECTION INLAND MAY BRIEFLY DISRUPT THE OTHERWISE SYNOPTIC SOUTHWESTERLY FLOW. NEXT FEW HOURS THIS MAY EVEN MEAN A QUICK TURN TO THE W OR NW BUT FOR THE MOST PART THERE MAY JUST BE A RELAXATION IN THE GRADIENT. ONCE THIS BOUNDARY WASHES OUT (MIDNIGHT-1AM) IT WILL BE BACK TO THE INLAND TROUGH-BORNE SOUTHWESTERLY FLOW. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 PM SUNDAY...SOUTHWEST FLOW WILL CONTINUE OVER THE WATERS THROUGH THE PERIOD WITH BERMUDA HIGH AND PIEDMONT TROUGH THE DOMINANT FEATURES. LATE IN THE PERIOD A WEAK COLD FRONT WILL DROP IN FROM THE NORTHWEST BUT WILL NOT REACH THE WATERS BEFORE THE END OF THE PERIOD. SOUTHWEST FLOW ON MON WILL BE IN THE 10 TO 15 KT RANGE...PEAKING AT A SOLID 15 KT IN THE EVENING. WINDS WILL BE SLIGHTLY HIGHER TUE WITH SPEEDS AROUND 15 KT INCREASING TO 15 TO 20 KT IN THE EVENING. SEAS 2 TO 4 FT ON MON WILL RUN 3 TO 4 FT TUE WITH POTENTIAL FOR SOME ISOLATED 5 FT NEAR 20 NM IN THE EVENING. ALTHOUGH CANNOT RULE OUT A MARGINAL SCEC TUE EVENING/NIGHT HEADLINES SEEM LIKE A LONG SHOT. LONG TERM /WEDNESDAY THROUGH THURSDAY/... AS OF 3 PM SUNDAY...A WEAK FRONT WILL DROP SOUTH REACHING INTO AREA WATERS ON WED. THE LATEST MODELS KEEP THIS BOUNDARY BISECTING WATERS WITH SLIGHTLY STRONGER WINDS OUT OF THE SW-W SOUTH OF BOUNDARY AND LIGHTER NORTHERLY FLOW BEHIND IT...MAINLY NORTH OF CAPE FEAR. AS SEA BREEZE DEVELOPS...WINDS WILL BECOME MORE ON SHORE THROUGH WED AND WILL REMAIN LIGHTER AND MORE VARIABLE WITH A GENERAL EASTERLY FLOW THROUGH THURS INTO FRI. THE WEAKENING FLOW WILL ALLOW LAND/SEA BREEZE TO DOMINATE THE WINDS WITH GREATER ON SHORE FLOW EACH AFTN AND A LIGHT OFF SHORE FLOW OVERNIGHT HEADING INTO THE WEEKEND. THIS LINGERING BOUNDARY WILL MEANDER ACROSS THE WATERS WHILE IT WEAKENS FURTHER THROUGH THE PERIOD. OVERALL EXPECT SEAS 2 TO 4 FT WITH A SLIGHT DOWNWARD TREND THROUGH WED AND SLIGHT UPWARD TREND THURS INTO FRI IN AN ON SHORE EASTERLY FLOW. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR SCZ017-023-024- 032-033-039-053>056. NC...HEAT ADVISORY FROM 1 PM TO 7 PM EDT MONDAY FOR NCZ087-096-099- 105>110. MARINE...NONE. && $$ NEAR TERM...MBB/TRA SHORT TERM...III LONG TERM...RGZ AVIATION...MRR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
945 PM CDT TUE JUL 21 2015 .UPDATE... ISSUED AT 938 PM CDT TUE JUL 21 2015 TRIMMED POPS AGAIN CENTRAL FOR TONIGHT BASED ON LATEST RADAR AND SATELLITE TRENDS. HRRR CONTINUES TO TO HOLD IONTO SOME CONVECTION WEST TONIGHT. BUT HAVE DOUBTS ABOUT THIS. INSTEAD WILL FOCUS ON THE JAMES RIVER VALLEY WHERE LIFT OVER THE WARM FRONT SHOULD PROVIDE MORE FOCUS FOR CONVECTION TONIGHT. UPDATE ISSUED AT 644 PM CDT TUE JUL 21 2015 LATEST HRRR RUN HINTS AT EXPANDING THE CONVECTIVE CLUSTER NORTHWARD INTO SOUTH CENTRAL NORTH DAKOTA DURING THE NEXT FEW HOURS ALONG AND NORTH OF THE WARM FRONTAL BOUNDARY. THIS MAY BE A LITTLE OPTIMISTIC CONSIDERING RADAR AND SATELLITE TRENDS. WILL TRIM POPS BACK ACROSS THE WEST AND CENTRAL THIS EVENING. HOWEVER WILL LEAVE THE TREND OF INCREASING POPS THIS EVENING ACROSS THE JAMES RIVER VALLEY IN PLACE FOR NOW. && .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY AFTERNOON) ISSUED AT 253 PM CDT TUE JUL 21 2015 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE SLIGHT CHANCES FOR THUNDERSTORMS MAINLY TODAY AND TONIGHT...FOLLOWED BY ANOTHER WARM DAY WEDNESDAY...THIS TIME MORE HUMID. CURRENTLY...WEAK MID LEVEL RIDGE AXIS OFF TO OUR WEST WITH A DEVELOPING SFC TROUGH OVER THE NORTHERN HIGH PLAINS. A FEW SCATTERED SHOWERS ABOUT...OVER MY FAR SOUTH AND EASTERN COUNTIES. LACK OF INSTABILITY CENTRAL AND EAST SO REMOVED THUNDER MENTION FOR THE DURATION OF TODAY FOR ALL BUT THE SOUTHWEST. WARM FRONT SLOWLY LIFTING NORTH INTO WESTERN AND SOUTHERN NORTH DAKOTA. WITH A DECENT SOUTHERLY MIXING FLOW COUPLED WITH CLEARING SKIES AND WAA...TEMPERATURES HAVE WARMED NICELY INTO THE 80S. COOLER WHERE CLOUD COVER REMAINS. HIGH RES MODELS STILL INDICATE A DESTABILIZING ATMOSPHERE MID TO LATE AFTERNOON WITH INCREASING THUNDERSTORM CHANCES ACROSS THE FAR SOUTHWEST AND FAR SOUTH CENTRAL INITIALLY NEAR THE WARM FRONT AND IN PROXIMITY TO A MID LEVEL WAVE OVER SOUTH DAKOTA. MODELS THEN HAVE THIS ACTIVITY SPREADING NORTH AND EAST WITH TIME IN THE EVENING. COVERAGE STILL REMAINS VERY UNCERTAIN WITH LATEST NSHARP ANALYSIS STILL SHOWING A CAPPING INVERSION IN PLACE ACROSS THE SOUTH WHERE CLOUDS REMAIN. DUE TO THIS AND LITTLE FORCING ALOFT OPTED TO KEEP OUR POPS SCATTERED TO ISOLATED WITH MOST LOCATIONS STAYING DRY TONIGHT. RIDGE AXIS MOVES EAST TONIGHT BUT REMAINS OVER THE DAKOTAS THROUGH MUCH OF WEDNESDAY. THIS KEEPS THE SFC TROUGH OVER EASTERN PORTIONS OF MONTANA AND WYOMING...AND WILL KEEP NORTH DAKOTA MAINLY DRY THROUGH TOMORROW AFTERNOON. WARM DAY WITH HIGHS WELL INTO THE 80S WITH PERHAPS A FEW LOW 90S WEST. MORE HUMID WEDNESDAY AS SFC DEWPOINTS IN THE 60S ARE TRANSPORTED INTO THE REGION THANKS TO A MID LEVEL SOUTHERLY FLOW STRETCHING AS FAR SOUTH AS THE SOUTHERN PLAINS ALL THE WAY NORTH INTO NORTH DAKOTA. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 253 PM CDT TUE JUL 21 2015 MAIN FORECAST ISSUE IS CONVECTIVE POTENTIAL ON THURSDAY...AND POTENTIAL OF A RISK OF SEVERE THUNDERSTORMS. WEDNESDAY EVENING A SOUTHERLY LOW LEVEL JET IS ESTABLISHED OVER THE EASTERN DAKOTAS WITH A SURFACE TROUGH IN THE LEE OF THE ROCKIES...AND SOUTHERLY SURFACE WINDS DRAWING 60-65F DEWPOINTS INTO THE EASTERN DAKOTAS. AT UPPER LEVELS A RIDGE IS IN PLACE UPSTREAM OF A LARGE UPPER LEVEL TROUGH AXIS OVER THE WEST COAST. AFTER MIDNIGHT WEDNESDAY NIGHT/THURSDAY MORNING...THE UPPER LEVEL RIDGE AXIS MOVES EAST INTO THE EASTERN DAKOTAS...AND THE LEADING EDGE OF UPPER LEVEL IMPULSES MOVING THROUGH THE SOUTHWEST FLOW ALOFT REACHES WESTERN NORTH DAKOTA. KEPT A CHANCE/SLIGHT CHANCE MENTION OF THUNDERSTORMS IN THE WEST LATE WEDNESDAY NIGHT. ON THURSDAY SEVERAL ROUNDS OF UPPER LEVEL IMPULSES MOVE NORTHEASTWARD ACROSS THE STATE IN THE ESTABLISHED SOUTHWEST FLOW ALOFT. AT THE SURFACE...A COLD FRONT AT THE WESTERN BORDER OF THE DAKOTAS THURSDAY MORNING IS FORECAST TO MOVE EAST ACROSS THE STATE THURSDAY AND THURSDAY NIGHT. DEWPOINTS REACH THE UPPER 60S TO AROUND 70 IN CENTRAL NORTH DAKOTA ON THURSDAY. THE SURFACE FRONT WILL BE THE MAIN FOCUS OF THE HIGHEST CAPE VALUES (HIGHEST IN THE AFTERNOON AND EVENING RANGING FROM 3000-5000 J/KG) THROUGH THE DAY AND NIGHT. THE HIGHEST BULK SHEAR VALUES APPEAR TO BE ALONG AND BEHIND THE SURFACE FRONT. THEREFORE THE BEST CHANCE THAT STORMS WOULD REACH SEVERE LEVELS WOULD BE MAINLY ALONG AND EITHER SIDE OF THE SURFACE FRONT. HAVE PUT THE MENTION OF POSSIBLE SEVERE THUNDERSTORMS THURSDAY MORNING IN THE FAR WEST...OVER ALL OF CENTRAL AND WESTERN NORTH DAKOTA IN THE AFTERNOON...AND IN CENTRAL NORTH DAKOTA THURSDAY EVENING. WARM AND HUMID WEDNESDAY EVENING AND NIGHT...WITH LOWS IN THE 60S. HOT AND HUMID THURSDAY WITH HIGHS MAINLY FROM THE MID 80S TO LOWER 90S. MAINLY ZONAL WEST-TO-EAST FLOW ALOFT FRIDAY...WITH A WEAK RIDGE BUILDING INTO OUR AREA SATURDAY AND SUNDAY. ONLY SLIGHT CHANCES TO NO CHANCES OF THUNDERSTORMS THESE TWO DAYS FOR A NICE REPRIEVE...ALTHOUGH AN UPPER LEVEL TROUGH IS FORMING OFF THE WEST COAST OVER THE WEEKEND. NOT AS HUMID FRIDAY AND SATURDAY...WITH HIGHS IN THE 80S...BUT INCREASING HUMIDITY ON SUNDAY. MONDAY THROUGH TUESDAY WILL SEE A RETURN OF ACTIVE WEATHER AS THE AFOREMENTIONED WEST COAST TROUGH LIFTS NORTHEASTWARD INTO THE PLAINS...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE BEGINNING OF NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 938 PM CDT TUE JUL 21 2015 AT 9 PM CDT A WARM FRONT EXTENDS ACROSS SOUTHWEST INTO SOUTH CENTRAL NORTH DAKOTA FROM LOW PRESSURE IN MONTANA. THE WARM FRONT WILL BE THE FOCUS FOR SCATTERED TO ISOLATED THUNDERSTORMS ACROSS SOUTH CENTRAL AND EAST CENTRAL NORTH DAKOTA TONIGHT. HOWEVER TOO MUCH UNCERTAINTY OTHER THAN VICINITY MENTION FOR KJMS. OTHERWISE VFR. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...NH LONG TERM...JV AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
937 PM CDT TUE JUL 21 2015 .UPDATE... ISSUED AT 937 PM CDT TUE JUL 21 2015 MADE A FEW FURTHER TWEAKS TO POPS. THERE CONTINUES TO BE SOME SCATTERED SHOWERS THAT ARE NOW REACHING THE GROUND OVER THE SOUTHERN CWA IN RESPONSE TO A WEAK SHORTWAVE COMING OVER THE TOP OF THE RIDGE. ANOTHER STRONGER SHORTWAVE IS COMING IN FROM THE WEST AND THE LOW LEVEL JET HAS STARTED TO EXTEND INTO CENTRAL ND FROM SD. THE HRRR SEEMS TO HAVE A DECENT HANDLE ON CURRENT ACTIVITY AND IT HAS THE SHOWERS IN THE SOUTH DISSIPATING AND MORE ACTIVITY FIRING JUST WEST OF THE RED RIVER LATER ON DURING THE EARLY MORNING HOURS. RAISED POPS IN THE SOUTH FOR THE NEXT HOUR OR SO AND THEN HAVE ACTIVITY TRANSITIONING FURTHER NORTH FROM THE DEVILS LAKE BASIN INTO THE RED RIVER VALLEY. NOT A LOT OF INSTABILITY TO WORK WITH SO WENT SHOWERS WITH ISOLATED THUNDER. UPDATE ISSUED AT 654 PM CDT TUE JUL 21 2015 TWEAKED POPS A BIT TONIGHT...A FEW STRONGER SHOWERS HAVE STARTED TO MORE INTO THE SOUTHWESTERN CWA...ALTHOUGH MOST OF THE RETURNS ARE NOT REACHING THE GROUND AT THIS POINT. THINK WE WILL GET SOME LIGHT RAIN REACHING THE GROUND EVENTUALLY...ESPECIALLY LATER TONIGHT AS THERE SHOULD BE SOME ACTIVITY ON THE NOSE OF THE LOW LEVEL JET. WILL KEEP SOME SCATTERED POPS GOING OVERNIGHT STARTING IN THE WEST AND TRANSITIONING INTO THE RED RIVER VALLEY TOWARDS MORNING. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 344 PM CDT TUE JUL 21 2015 UPPER AIR PATTERN WAS PROGRESSIVE. UPPER LEVEL RIDGE OVER THE HIGH PLAINS WILL BUILD TONIGHT AND MOVE OVER THE FORECAST AREA BY 12Z THU. PRECIPITABLE WATER RISES TO OVER AN INCH THIS AFTERNOON AS CROSS SECTION INDICATES MID LEVEL MOISTURE TO MOVE IN. BIS SOUNDING INDICATED MUCH OF THE MOISTURE WAS MOVING IN BETWEEN 750 AND 550 HPA. LOW LEVEL MOISTURE TO FOLLOW ON THU. UPPER LEVEL TROUGH OFF THE WEST COAST WILL MOVE ACROSS THE NORTHERN PLAINS AROUND 84 HOURS AS UPSTREAM TROUGH MOVES INTO THE GULF OF AK. PRECIPITABLE WATER RISES TO 1.5 TO 2 INCHES BY LATE THU. NAM AND GFS SHOWALTERS BECOME QUITE NEGATIVE FOR THU NIGHT WHILE THE ECMWF WAS MUCH LESS NEGATIVE. MODEL SOUNDINGS SHOW WARM MID LEVEL TEMPS IN PLACE THU AFTERNOON WILL CAP ATMOSPHERE PRE-FRONTALLY. 700 HPA TEMPS RISE ABOVE 10C. MID LEVEL TEMPS RISE WED NIGHT AND BEGIN TO CAP ATMOSPHERE. THUNDERSTORMS SHOULD OCCUR NEAR OR POST FRONTAL WITH SURFACE TROUGH MOVING THROUGH THU NIGHT. WILL ADD SEVERE WORDING FOR THU NIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 344 PM CDT TUE JUL 21 2015 FOR FRI NIGHT THROUGH TUE...TEMPS SHOULD REMAIN ABOVE NORMAL THROUGH AT LEAST THIS WEEKEND INTO EARLY NEXT WEEK. THE BEST CHANCE FOR SHOWERS AND STORMS SHOULD OCCUR EARLY NEXT WEEK AHEAD OF A COLD FRONT...WITH A DRY WEEKEND EXPECTED FOR THE MOST PART. BOTH THE GFS AND ECMWF INDICATE A SW FLOW ON MON NIGHT INTO TUE WITH A MORE WIDEPSREAD CONVECTIVE EVENT POSSIBLE...DEPENDING ON EXACT TIMING OF SHORTWAVE. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 654 PM CDT TUE JUL 21 2015 CONDITIONS WILL REMAIN VFR THROUGHOUT THE PERIOD. SOME SCATTERED SHOWERS MOVING INTO THE AREA ARE NOT REACHING THE GROUND QUITE YET...BUT WILL IMPACT KFAR TOWARDS 06Z AS WE SHOULD SEE ACTIVITY RAMPING UP. HAVE VCSH AROUND THAT TIME FOR KFAR AND GOING ON NOW AT KDVL BUT HAVE IT HOLDING BACK AT KGFK AND KTVF AS PRECIP ONLY SLOWLY MOVES NORTHEASTWARD. WIND SHOULD STEADY OUT OF THE SOUTH AND THEN BEGIN TO INCREASE ABOVE 10 KTS LATE IN THE PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...HOPPES LONG TERM...DK AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
654 PM CDT TUE JUL 21 2015 .UPDATE... ISSUED AT 644 PM CDT TUE JUL 21 2015 LATEST HRRR RUN HINTS AT EXPANDING THE CONVECTIVE CLUSTER NORTHWARD INTO SOUTH CENTRAL NORTH DAKOTA DURING THE NEXT FEW HOURS ALONG AND NORTH OF THE WARM FRONTAL BOUNDARY. THIS MAY BE A LITTLE OPTIMISTIC CONSIDERING RADAR AND SATELLITE TRENDS. WILL TRIM POPS BACK ACROSS THE WEST AND CENTRAL THIS EVENING. HOWEVER WILL LEAVE THE TREND OF INCREASING POPS THIS EVENING ACROSS THE JAMES RIVER VALLEY IN PLACE FOR NOW. && .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY AFTERNOON) ISSUED AT 253 PM CDT TUE JUL 21 2015 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE SLIGHT CHANCES FOR THUNDERSTORMS MAINLY TODAY AND TONIGHT...FOLLOWED BY ANOTHER WARM DAY WEDNESDAY...THIS TIME MORE HUMID. CURRENTLY...WEAK MID LEVEL RIDGE AXIS OFF TO OUR WEST WITH A DEVELOPING SFC TROUGH OVER THE NORTHERN HIGH PLAINS. A FEW SCATTERED SHOWERS ABOUT...OVER MY FAR SOUTH AND EASTERN COUNTIES. LACK OF INSTABILITY CENTRAL AND EAST SO REMOVED THUNDER MENTION FOR THE DURATION OF TODAY FOR ALL BUT THE SOUTHWEST. WARM FRONT SLOWLY LIFTING NORTH INTO WESTERN AND SOUTHERN NORTH DAKOTA. WITH A DECENT SOUTHERLY MIXING FLOW COUPLED WITH CLEARING SKIES AND WAA...TEMPERATURES HAVE WARMED NICELY INTO THE 80S. COOLER WHERE CLOUD COVER REMAINS. HIGH RES MODELS STILL INDICATE A DESTABILIZING ATMOSPHERE MID TO LATE AFTERNOON WITH INCREASING THUNDERSTORM CHANCES ACROSS THE FAR SOUTHWEST AND FAR SOUTH CENTRAL INITIALLY NEAR THE WARM FRONT AND IN PROXIMITY TO A MID LEVEL WAVE OVER SOUTH DAKOTA. MODELS THEN HAVE THIS ACTIVITY SPREADING NORTH AND EAST WITH TIME IN THE EVENING. COVERAGE STILL REMAINS VERY UNCERTAIN WITH LATEST NSHARP ANALYSIS STILL SHOWING A CAPPING INVERSION IN PLACE ACROSS THE SOUTH WHERE CLOUDS REMAIN. DUE TO THIS AND LITTLE FORCING ALOFT OPTED TO KEEP OUR POPS SCATTERED TO ISOLATED WITH MOST LOCATIONS STAYING DRY TONIGHT. RIDGE AXIS MOVES EAST TONIGHT BUT REMAINS OVER THE DAKOTAS THROUGH MUCH OF WEDNESDAY. THIS KEEPS THE SFC TROUGH OVER EASTERN PORTIONS OF MONTANA AND WYOMING...AND WILL KEEP NORTH DAKOTA MAINLY DRY THROUGH TOMORROW AFTERNOON. WARM DAY WITH HIGHS WELL INTO THE 80S WITH PERHAPS A FEW LOW 90S WEST. MORE HUMID WEDNESDAY AS SFC DEWPOINTS IN THE 60S ARE TRANSPORTED INTO THE REGION THANKS TO A MID LEVEL SOUTHERLY FLOW STRETCHING AS FAR SOUTH AS THE SOUTHERN PLAINS ALL THE WAY NORTH INTO NORTH DAKOTA. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 253 PM CDT TUE JUL 21 2015 MAIN FORECAST ISSUE IS CONVECTIVE POTENTIAL ON THURSDAY...AND POTENTIAL OF A RISK OF SEVERE THUNDERSTORMS. WEDNESDAY EVENING A SOUTHERLY LOW LEVEL JET IS ESTABLISHED OVER THE EASTERN DAKOTAS WITH A SURFACE TROUGH IN THE LEE OF THE ROCKIES...AND SOUTHERLY SURFACE WINDS DRAWING 60-65F DEWPOINTS INTO THE EASTERN DAKOTAS. AT UPPER LEVELS A RIDGE IS IN PLACE UPSTREAM OF A LARGE UPPER LEVEL TROUGH AXIS OVER THE WEST COAST. AFTER MIDNIGHT WEDNESDAY NIGHT/THURSDAY MORNING...THE UPPER LEVEL RIDGE AXIS MOVES EAST INTO THE EASTERN DAKOTAS...AND THE LEADING EDGE OF UPPER LEVEL IMPULSES MOVING THROUGH THE SOUTHWEST FLOW ALOFT REACHES WESTERN NORTH DAKOTA. KEPT A CHANCE/SLIGHT CHANCE MENTION OF THUNDERSTORMS IN THE WEST LATE WEDNESDAY NIGHT. ON THURSDAY SEVERAL ROUNDS OF UPPER LEVEL IMPULSES MOVE NORTHEASTWARD ACROSS THE STATE IN THE ESTABLISHED SOUTHWEST FLOW ALOFT. AT THE SURFACE...A COLD FRONT AT THE WESTERN BORDER OF THE DAKOTAS THURSDAY MORNING IS FORECAST TO MOVE EAST ACROSS THE STATE THURSDAY AND THURSDAY NIGHT. DEWPOINTS REACH THE UPPER 60S TO AROUND 70 IN CENTRAL NORTH DAKOTA ON THURSDAY. THE SURFACE FRONT WILL BE THE MAIN FOCUS OF THE HIGHEST CAPE VALUES (HIGHEST IN THE AFTERNOON AND EVENING RANGING FROM 3000-5000 J/KG) THROUGH THE DAY AND NIGHT. THE HIGHEST BULK SHEAR VALUES APPEAR TO BE ALONG AND BEHIND THE SURFACE FRONT. THEREFORE THE BEST CHANCE THAT STORMS WOULD REACH SEVERE LEVELS WOULD BE MAINLY ALONG AND EITHER SIDE OF THE SURFACE FRONT. HAVE PUT THE MENTION OF POSSIBLE SEVERE THUNDERSTORMS THURSDAY MORNING IN THE FAR WEST...OVER ALL OF CENTRAL AND WESTERN NORTH DAKOTA IN THE AFTERNOON...AND IN CENTRAL NORTH DAKOTA THURSDAY EVENING. WARM AND HUMID WEDNESDAY EVENING AND NIGHT...WITH LOWS IN THE 60S. HOT AND HUMID THURSDAY WITH HIGHS MAINLY FROM THE MID 80S TO LOWER 90S. MAINLY ZONAL WEST-TO-EAST FLOW ALOFT FRIDAY...WITH A WEAK RIDGE BUILDING INTO OUR AREA SATURDAY AND SUNDAY. ONLY SLIGHT CHANCES TO NO CHANCES OF THUNDERSTORMS THESE TWO DAYS FOR A NICE REPRIEVE...ALTHOUGH AN UPPER LEVEL TROUGH IS FORMING OFF THE WEST COAST OVER THE WEEKEND. NOT AS HUMID FRIDAY AND SATURDAY...WITH HIGHS IN THE 80S...BUT INCREASING HUMIDITY ON SUNDAY. MONDAY THROUGH TUESDAY WILL SEE A RETURN OF ACTIVE WEATHER AS THE AFOREMENTIONED WEST COAST TROUGH LIFTS NORTHEASTWARD INTO THE PLAINS...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE BEGINNING OF NEXT WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 644 PM CDT TUE JUL 21 2015 A WARM FRONTAL BOUNDARY EXTENDS ACROSS EASTERN MONTANA INTO NORTHERN SOUTH DAKOTA EARLY TUESDAY EVENING AND IS FORECAST TO LIFT NORTHEAST ACROSS NORTH DAKOTA TONIGHT. THE FRONT WILL BE THE FOCUS FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE JAMES RIVER VALLEY THROUGH EASTERN NORTH DAKOTA TONIGHT. VFR CONDITIONS ARE FORECAST THROUGH THE 00Z TAF PERIOD. THUNDERSTORMS TOO UNCERTAIN TO ADD TO KJMS TAF AT THIS TIME OTHER THAN VCTS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...NH LONG TERM...JV AVIATION...WAA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
406 PM EDT MON JUL 20 2015 .SYNOPSIS... A WEAK SHORTWAVE WILL MOVE EAST THROUGH THE OHIO VALLEY TODAY...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY NEAR AND SOUTH OF THE OHIO RIVER. A COLD FRONT WILL MOVE SOUTHEAST THROUGH THE REGION ON TUESDAY...WITH DRIER AND SLIGHTLY COOLER CONDITIONS EXPECTED THROUGH THE MIDDLE OF THE WEEK. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... THE AIR MASS OVER THE OHIO VALLEY REMAINS WARM AND MOIST...THOUGH NOT QUITE TO THE EXTENT THAT IT WAS OVER THE WEEKEND. DEWPOINTS ARE IN THE UPPER 60S TO MID 70...BUT SURFACE TEMPERATURES ARE GENERALLY IN THE MID 80S...RATHER THAN PUSHING TOWARD 90 DEGREES. THERE HAVE BEEN SEVERAL LAYERS OF CLOUDS HELPING TO SLIGHTLY INHIBIT HEATING...WITH THICK LAYERS OF CUMULUS (2500-4000 FEET) AND SOME HIGH CLOUDS MOVING IN THE WESTERLY FLOW ALOFT. SPC MESOANALYSIS INDICATES THAT THE SOUTHERN HALF OF THE FORECAST AREA HAS BEEN ABLE TO DEVELOP ABOUT 1500 J/KG OF MLCAPE. A WEAK MID-LEVEL WAVE IS FORECAST TO MOVE EAST THROUGH THE REGION THIS EVENING...AND THERE ARE SIGNS OF A WEAK VORTICITY CENTER OVER SOUTHEASTERN ILLINOIS...MOVING INTO INDIANA AS OF ABOUT 19Z. SHOWER AND THUNDERSTORM DEVELOPMENT IS EXPECTED TO BEGIN DURING THE NEXT FEW HOURS...MAINLY IMPACTING THE SOUTHERN HALF OF THE FORECAST AREA BETWEEN 22Z-04Z. THERE APPEARS TO BE JUST ENOUGH DEEP-LAYER SHEAR AND INSTABILITY TO SUPPORT A RISK FOR A FEW STRONG STORMS...THOUGH NONE OF THE HIGH-RES GUIDANCE (12Z SPC-WRF OR RECENT HRRR RUNS) INDICATE THAT DEVELOPMENT WILL BE PARTICULARLY EXPLOSIVE. WITH WEAK FORCING THAT TIMES OUT A LITTLE TOO LATE FOR THE PEAK OF THE DIURNAL CYCLE...THE SEVERE THREAT APPEARS LIMITED. PRECIPITATION POTENTIAL WILL DIMINISH DURING THE SECOND HALF OF THE OVERNIGHT...AS THE SHORTWAVE MOVES AWAY...AND THE DIURNAL CYCLE HEADS TOWARD ITS LOWER END. HOWEVER...THE AIR MASS WILL NOT YET BE CHANGING SIGNIFICANTLY...AS THE APPROACHING COLD FRONT WILL STILL BE NORTH OF THE FORECAST AREA. THUS...ANOTHER ROUND OF FAIRLY WARM MIN TEMPS CAN BE EXPECTED...WITH LOWER 70S IN THE SOUTH AND UPPER 60S IN THE NORTH. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... ON TUESDAY MORNING...A COLD FRONT WILL BE MOVING ACROSS THE MICHIGAN BORDER...CONTINUING ITS SOUTHEASTWARD TREK INTO INDIANA AND OHIO. THIS FRONT DELINEATES THE LEADING EDGE OF A SLIGHTLY COOLER AND SIGNIFICANTLY DRIER AIR MASS...WHICH WILL BE MOVING INTO THE OHIO VALLEY FOR THE MIDDLE OF THE WEEK. TUESDAY WILL STILL BE A TRANSITION DAY FOR THE REGION...THOUGH PREVAILING DRY CONDITIONS ARE LIKELY FOR MOST OF THE FORECAST AREA. FORCING ALONG THE FRONT IS NOT PARTICULARLY STRONG...AND OVERALL MOISTURE CONTENT IS NOTHING NOTEWORTHY FOR JULY (CLOSE TO CLIMATOLOGICAL MEANS BETWEEN 1.0-1.5 INCHES). NORTH WINDS AND DRIER AIR WILL ALREADY BE MOVING INTO THE NORTHERN SECTIONS OF THE FORECAST AREA BY NOON...ESSENTIALLY ENDING ANY CHANCE FOR A PASSING SHOWER. HOWEVER...FOR THE SOUTHEASTERN THIRD OF THE FORECAST AREA...INSTABILITY IS EXPECTED TO BUILD AHEAD OF THE FRONT. THUS...MAINLY BETWEEN NOON AND 6PM...SOME SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP. WITH THE PASSAGE OF THE FRONT...THERE SHOULD BE A GRADIENT FOR MAX TEMPS...WITH UPPER 70S IN THE NORTH AND MID 80S IN THE SOUTH. SKIES WILL CLEAR FROM THE NORTH DURING THE EVENING...AND MOSTLY CLEAR CONDITIONS ARE EXPECTED OVERNIGHT. WITH DEWPOINTS ALSO SIGNIFICANTLY LOWER THAN EARLY TUESDAY MORNING (AS MUCH AS 10-15 DEGREES LOWER)...MIN TEMPS WILL EASILY BE ABLE TO DROP BELOW NORMAL BY WEDNESDAY MORNING...IN THE UPPER 50S TO AROUND 60 DEGREES. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... HAVE USED A BLEND OF THE GFS/ECMWF/WPC FOR THE LONG TERM FORECAST. FOR THE PERIOD WEDNESDAY THROUGH FRIDAY...AS A MID LEVEL RIDGE REASSERTS ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY...WITH JUST SOME CLOUDS FROM TIME TO TIME. FOR THE WEEKEND...IT NOW LOOKS LIKE A WEAK FRONTAL SYSTEM WILL PUSH THROUGH OUR REGION. WE MAY REMAIN DRY DURING THE DAY SATURDAY...WITH CHANCE POPS FOR SHOWERS/STORMS ADDED TO THE FORECAST FOR SATURDAY NIGHT INTO SUNDAY. FOR MONDAY...CURRENT FORECAST CALLS FOR DRY CONDITIONS AS MODELS SUGGEST WE WILL BE BETWEEN SYSTEMS. DRIER AIR AND SLIGHTLY BELOW NORMAL TEMPERATURES CAN BE EXPECTED THROUGH AT LEAST FRIDAY...WITH AN UPTICK IN HIGHS AND HUMIDITY BY THE WEEKEND INTO NEXT WEEK. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... PESKY STRATUS DECK AT KILN IS FINALLY BREAKING UP AND REST OF CWA WILL CONTINUE TO SEE CU DEVELOPMENT THIS AFTERNOON TOPPED BY THIN CI. STORMS WILL BECOME MORE PROMINENT LATER THIS EVENING AND END OVERNIGHT. SURFACE FRONT CROSSES CWA TOWARDS 12Z TOMORROW MORNING AND WINDS SHIFT NORTHWARD WITH A DRIER AIRMASS EXPECTED IN ITS WAKE AS HIGH PRESSURE BUILDS NORTH AND WEST OF THE REGION. VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORM ACTIVITY TONIGHT. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED AT THIS TIME. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM...HICKMAN AVIATION...FRANKS
THE LONG TERM FORECAST DISCUSSION WILL BE UPDATED SHORTLY

PREVIOUS DISCUSSION > UPPER RIDGING WILL DEVELOP INTO THE REGION DURING THE LATTER PART OF THE WEEK. BUT THEN ANOTHER SYSTEM MOVING ALONG THE NORTHERN TIER WILL SUPPRESS THE RIDGE AND TEMPORARILY BRING TROUGHING BACK TO THE GREAT LAKES AND UPPER OHIO VALLEY OVER THE WEEKEND. AT THE SURFACE HIGH PRESSURE WILL PREDOMINATE THROUGH FRIDAY WITH BELOW NORMAL TEMPERATURES THAT WILL SLOWLY MODERATE. FORECAST THEN LEANS TOWARDS GFS ENSEMBLE MEAN WHICH IS A COMPROMISE BETWEEN MORE AGGRESSIVE/FASTER 00Z GFS AND SLOWER 00Z ECMWF IN DROPPING A FRONT INTO THE REGION OVER THE WEEKEND. THIS FRONT WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS ALTHOUGH TEMPERATURES WILL BE SEASONAL. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... PESKY STRATUS DECK AT KILN IS FINALLY BREAKING UP AND REST OF CWA WILL CONTINUE TO SEE CU DEVELOPMENT THIS AFTERNOON TOPPED BY THIN CI. STORMS WILL BECOME MORE PROMINENT LATER THIS EVENING AND END OVERNIGHT. SURFACE FRONT CROSSES CWA TOWARDS 12Z TOMORROW MORNING AND WINDS SHIFT NORTHWARD WITH A DRIER AIRMASS EXPECTED IN ITS WAKE AS HIGH PRESSURE BUILDS NORTH AND WEST OF THE REGION. VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORM ACTIVITY TONIGHT. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED AT THIS TIME. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM... AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
450 PM PDT TUE JUL 21 2015 UPDATED AVIATION SECTION .SHORT TERM...AS ADVERTISED...THUNDERSTORMS ARE FIRING UP IN SISKIYOU AND MODOC COUNTIES THIS AFTERNOON. STORMS WILL CONTINUE THROUGH THE EVENING AND MAY LINGER WELL AFTER SUNSET AS THEY GET TRIGGERED BY A SHORTWAVE APPROACHING THE COAST. THE TROF ASSOCIATED WITH THIS SHORTWAVE WILL CONTINUE TO ALSO APPROACH THE COAST OVERNIGHT. INSTABILITY TOMORROW LOOKS TO BE IN THE SAME GENERAL AREA AS TODAY. THE DIFFERENCE IS IN THE AMOUNT OF MOISTURE AVAILABLE TO FEED STORMS. DRIER AIR WILL MOVE INTO SISKIYOU AND WESTERN MODOC COUNTY TOMORROW AFTERNOON SO ANY STORMS THAT DEVELOP WILL BE FEWER AND SMALLER. HOWEVER...EASTERN MODOC COUNTY COULD STILL SEE MORE AND BIGGER STORMS. IT JUST DEPENDS ON HOW QUICKLY THE TROF AND DRIER AIR SWEEPS EASTWARD. .LONG TERM...COOLER AND MORE STABLE AIR UNDER A WESTERLY FLOW TAKES OVER ON THURSDAY AND CONTINUES THROUGH EARLY NEXT WEEK. ANOTHER WEAK TROF MOVES THROUGH THE PACIFIC NORTHWEST ON SUNDAY. THIS WILL KEEP TEMPERATURES SLIGHTLY BELOW NORMAL. WESTERLY WINDS COULD BE BREEZY AT TIMES ESPECIALLY ON EXPOSED MOUNTAIN RIDGES. && .AVIATION...FOR THE 22/00Z TAF CYCLE...THUNDERSTORMS ARE CURRENTLY ONGOING ACROSS PORTIONS OF NORTHERN CALIFORNIA AND EAST OF THE CASCADES AND WILL CONTINUE UNTIL SHORTLY AFTER SUNSET. THESE STORMS WILL PRODUCE FREQUENT LIGHTNING, HEAVY RAIN, AND SMALL HAIL. OTHERWISE, THE MAIN CONCERN WILL BE GUSTY WINDS ACROSS THE ENTIRE FORECAST AREA. THE WINDS ARE EXPECTED TO DIMINISH THIS EVENING BEFORE RETURNING TOMORROW AFTERNOON. SKIES WILL REMAIN VFR EXCEPT FOR THE UMPQUA BASIN WHICH COULD SEE BRIEF PERIODS OF MVFR SKIES...AND THE COAST WHICH WILL BECOME IFR THIS EVENING BEFORE SCATTERING BACK OUT TOMORROW MORNING. -SCHAAF && .MARINE...UPDATED 300 PM PDT, TUESDAY, 21 JULY 2015... NORTH WINDS WILL PEAK THIS EVENING AS HIGH PRESSURE BUILDS INTO THE PACIFIC NORTHWEST AND LOW PRESSURE NUDGES NORTHWARD ALONG THE COAST IN NORTHERN CALIFORNIA. A HAZARDOUS SEAS AND GALE WARNING HAVE BEEN ISSUED FOR THE INCREASE IN WINDS AND SEAS WEST OF PISTOL RIVER SOUTH THROUGH PORT SAINT GEORGE. WINDS WILL WEAKEN OVERNIGHT BUT REMAIN IN ADVISORY LEVELS THROUGH WEDNESDAY NIGHT. THE HIGH PRESSURE IS THEN FORECAST TO SHIFT INLAND ON THURSDAY CAUSING THE NORTH WINDS TO WEAKEN. SHORT PERIOD SEAS AND WINDS ARE EXPECTED TO FALL TO BELOW ADVISORY THRESHOLDS ON WEDNESDAY EVENING WHERE THEY SHOULD REMAIN THROUGH THE WEEKEND. -SCHAAF && .FIRE WEATHER...UPDATED 130 PM PDT, TUESDAY 21 JULY 2015... THE GFS, NAM, RAP, AND HRRR MODELS ARE IN EXCELLENT AGREEMENT REGARDING THE EXTENT OF INSTABILITY AND THE LOCATION OF THUNDERSTORMS THROUGH TONIGHT. THE RED FLAG WARNING REMAINS IN EFFECT THROUGH THIS EVENING FOR EASTERN SISKIYOU COUNTY, EXTREME SOUTHEAST KLAMATH COUNTY, SOUTHERN LAKE COUNTY, AND MODOC COUNTY. A FEW THUNDERSTORMS HAVE ALREADY DEVELOPED IN THAT AREA WITH COVERAGE EXPECTED TO EXPAND TO SCATTERED AS THERE IS A SHORTWAVE ALONG THE NORTHERN CALIFORNIA COAST NEAR CAPE MENDOCINO AND ANOTHER ALONG THE CALIFORNIA/NEVADA BORDER THAT WILL MOVE NORTH TO NORTHEAST. A BIT BEYOND THE RED FLAG WARNED AREA, ISOLATED THUNDERSTORMS ARE EXPECTED FARTHER WEST AND NORTH TO SOUTHWEST SISKIYOU COUNTY, THE NORTHERN CALIFORNIA CASCADES TO THE KLAMATH BASIN AND MUCH OF THE REMAINDER OF LAKE COUNTY. THE CELLS WILL PRODUCE MODERATE TO HEAVY RAIN BUT WILL BE FASTER MOVING THAN USUAL AT 15 TO 20 KT, WHICH WILL INCREASE THE RISK OF LIGHTNING PRODUCING FIRE STARTS. AFTER THIS EVENING INTO WEDNESDAY MORNING, ACTIVITY IS EXPECTED TO DIMINISH BUT NOT ALTOGETHER END AS A SHORTWAVE LINGERS OVER THE EAST SIDE AND THE LARGER SCALE UPPER TROUGH WORKS ITS WAY INTO THE PACIFIC NORTHWEST. WITH LITTLE CHANGE NECESSARY IN THE FIRST PERIOD OF THE FORECAST, THE QUESTION OF THE DAY WAS THE EXPECTED COVERAGE OF THUNDERSTORMS ON WEDNESDAY AFTERNOON. THE UPPER TROUGH WILL KICK THE REGION OF DEEPER MOISTURE EAST TO THE EASTERN EDGE OF OUR AREA...INCLUDING THE WARNER MOUNTAINS...AND EXTENDING TO THE EAST OUT OF OUR AREA. BUT, THE GFS INDICATES SURFACE BASED CAPE VALUES OF 250 TO 750 J/KG IN NORTHERN CALIFORNIA AND SOUTHERN LAKE COUNTY ON WEDNESDAY COMPARED TO VALUES OF 750 TO 1500 J/KG TODAY. THUS, WILL HOLD EXPECTED COVERAGE OF THUNDERSTORMS TO ISOLATED WITH A FOCUS FOR THE HIGHEST PROBABILITY IN SOUTHEAST LAKE COUNTY. THE ARRIVAL OF THE TROUGH WILL ALSO PRODUCE SLIGHTLY STRONGER THAN NORMAL AFTERNOON AND EVENING WESTERLY WINDS. THE UPPER TROUGH WILL CONTINUE TO TRACK EAST ON THURSDAY WITH A WARM, STABLE AIR MASS ARRIVING. NEAR NORMAL TEMPERATURES AND BREEZY WESTERLY AFTERNOON WINDS ARE EXPECTED AT THE END OF WEEK INTO EARLY NEXT WEEK. /DW && .MFR WATCHES/WARNINGS/ADVISORIES... OR...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR ORZ624-625. CA...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR CAZ284-285. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THURSDAY FOR PZZ350-356-370-376. SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT WEDNESDAY FOR PZZ356-376. HAZARDOUS SEAS WARNING FROM 11 PM THIS EVENING TO 11 PM PDT WEDNESDAY FOR PZZ356-376. $$ KRS/KRS/BMS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
827 AM PDT MON JUL 20 2015 .DISCUSSION...ANOTHER MORNING WITH LOW CLOUDS WELL ENTRENCHED ALONG THE COAST, AND INTO THE COASTAL VALLEYS NORTH OF CAPE BLANCO. HAVE UPDATED CLOUD FIELDS IN THE FORECAST TO BRING THINGS IN LINE WITH CURRENT SATELLITE OBSERVATIONS AND THE EXPECTED TRENDS, BUT MADE VERY LITTLE CHANGES ELSEWHERE. MAIN FOCUS OF EFFORTS TO DAY WILL BE THE THUNDERSTORM CHANCES OVER THE NEXT THREE DAYS. THE FIRST ROUND THIS EVENING, LIKELY TO BE THE WEAKEST OF THE THREE, IS ONLY EXPECTED TO IMPACT AREAS BETWEEN MEDICINE LAKE AND THE TRINITY ALPS IN SISKIYOU COUNTY, AND THIS IS SUPPORTED BY THE HIGHER RESOLUTION HRRR AND NAM MODEL VARIANTS. HOWEVER, CHANCES EXPAND NORTH AND EAST TUESDAY, THEN MORE SO WEDNESDAY. THE LIMITING FACTOR FOR CONVECTION WOULD APPEAR TO BE THE TIMING AND STRENGTH OF A TRIGGER FEATURE, AND THIS HAS THROWN A GOOD DEAL OF UNCERTAINTY INTO THE MIX. FEEL CONFIDENT THAT ISOLATED STORMS WILL FORM, BUT MUCH LESS SO THAT SCATTERED DEVELOPMENT WILL OCCUR. WILL EVALUATE LATEST MODEL RUNS AND ADJUST THE FORECAST AS NECESSARY FOR THE AFTERNOON PACKAGE. SEE THE PREVIOUS DISCUSSION BELOW FOR ADDITIONAL INFORMATION. -BPN && .AVIATION...FOR THE 20/12Z TAF CYCLE...STRATUS WITH IFR TO LIFR CIGS/VIS WILL CONTINUE ALONG MUCH OF THE IMMEDIATE COASTLINE, INCLUDING AT KOTH, INTO THE MORNING, THEN GRADUALLY LIFT. ELSEWHERE, VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. /FB && .MARINE...UPDATED 815 AM PDT, MONDAY, 19 JULY 2015... NORTH WINDS WILL RETURN TODAY AS HIGH PRESSURE REBUILDS FROM THE WEST AND LOW PRESSURE NUDGES NORTHWARD FROM CALIFORNIA. NORTH WINDS AND SEAS ARE EXPECTED TO REACH ADVISORY LEVELS SOUTH OF CAPE BLANCO THIS AFTERNOON THROUGH TUESDAY EVENING BEFORE THEY BEGIN TO SUBSIDE WEDNESDAY THROUGH THURSDAY. THE WIND ADVISORY AREA IS EXPECTED TO SHRINK FOR WEDNESDAY TO A PORTION OF THE AREA SOUTH OF CAPE BLANCO BEYOND 10 NAUTICAL MILES WEST OF GOLD BEACH AND POINT SAINT GEORGE, WHILE ADVISORY LEVEL SEAS WILL BE SLOWER TO SUBSIDE. WINDS AND SEAS ARE EXPECTED TO BE MOST HAZARDOUS LATE TUESDAY AFTERNOON THROUGH MID EVENING. HIGH PRESSURE OFFSHORE IS EXPECTED TO SHIFT INLAND SOME LATER THIS WEEK CAUSING THESE NORTH WINDS TO WEAKEN. /FB && .FIRE WEATHER...UPDATED 600 AM PDT, MONDAY 18 JULY 2015...MOISTURE AND WEAK DISTURBANCES MOVING UP FROM THE SOUTH WILL BRING A SLIGHT CHANCE FOR THUNDERSTORMS IN SOUTHERN SISKIYOU AND SOUTHERN MODOC COUNTIES THIS AFTERNOON AND EVENING. THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE ON TUESDAY AS ADDITIONAL MID LEVEL MOISTURE AND DISTURBANCE MOVE INTO THE AREA FROM THE SOUTH. WITH THE BEST POTENTIAL FOR SCATTERED STORMS ON TUESDAY NEAR AND NORTHEAST OF MOUNT SHASTA AND OVER EASTERN AREAS, ESPECIALLY ZONES 284, 285, SOUTHEAST 624 AND SOUTHERN 625. PRECIPITABLE WATER WILL NOT BE AS HIGH AS WHEN THE LAST ROUND OF STORMS WENT THROUGH AROUND 2 WEEKS AGO. MOREOVER STORMS ARE EXPECTED TO MOVE WEST TO EAST QUICKLY AT 10 TO 15 MPH ON TUESDAY RESULTING IN ONLY LIGHT TO MODERATE RAIN. A FIRE WEATHER WATCH WAS ISSUED EARLIER TO REFLECT THE POTENTIAL FOR SCATTERED THUNDERSTORM COVERAGE ON TUESDAY. SEE DETAILED HAZARD ON OUR HOMEPAGE FOR THE ACTUAL LOCATION. ON WEDNESDAY, THE UPPER TROUGH WILL BRING A MARINE PUSH INLAND WITH SEVERAL DEGREES OF COOLING AND BREEZY SOUTHWEST TO WEST FLOW. THE STRONGEST WINDS ARE EXPECTED FROM THE CASCADES EAST WITH WINDS OF 10 TO 15 MPH AND GUSTS UP TO 30 MPH. MODELS CONTINUE TO INDICATE A POTENTIAL FOR THUNDERSTORMS INTO WEDNESDAY EAST OF THE CASCADES IN OREGON AND FROM CENTRAL SISKIYOU COUNTY EASTWARD INTO MODOC COUNTY. /FB && .PREV DISCUSSION... /ISSUED 625 AM PDT MON JUL 20 2015/ UPDATED AVIATION AND FIRE WEATHER SECTIONS. DISCUSSION...TODAY WILL FEATURE ONE MORE ROUND OF WARM TEMPERATURES ACROSS INLAND PORTIONS OF THE FORECAST AREA...WITH READINGS EXPECTED TO PEAK THIS AFTERNOON ABOUT 5 DEGREES ABOVE NORMAL VALUES. MIDLEVEL FLOW WILL SWITCH TO SOUTHERLY OVER NORTHERN CALIFORNIA...AND THIS WILL USHER IN ENOUGH MOISTURE...LOOSELY CONNECTED TO REMNANTS OF TROPICAL STORM DOLORES...TO SUPPORT A SLIGHT CHANCE OF THUNDERSTORMS OVER SISKIYOU AND MODOC COUNTIES. THE SLIGHT CHANCE OF STORMS CONTINUES OVERNIGHT DUE TO NAM12 H7-H5 MUCAPE IN THE HUNDREDS AND STEEP UPPER LEVEL LEVEL RATES. A WELL- DEFINED MARINE LAYER WILL CONTINUE TO AFFECT THE COAST MUCH OF TODAY...WITH COASTAL VALLEYS SEEING SUNSHINE IN THE AFTERNOON. ON TUESDAY MORE MOISTURE WILL FEED INTO NORTHERN CALIFORNIA AND WILL ACT IN CONCERT WITH COOLING TEMPERATURES ALOFT...SOME DEFORMATION ASSOCIATED WITH THE APPROACHING UPPER TROUGH...AND WEAK IMPULSE ALOFT TO GENERATE THE POTENTIAL FOR SCATTERED THUNDERSTORMS. THE GFS AND NAM ARE IN GOOD AGREEMENT WITH THE AXIS OF MOST SIGNIFICANT INSTABILITY...WITH BOTH SHOWING SWATHS OF -3C 850MB COMPUTED LI VALUES...AND LITTLE IN THE WAY OF CONVECTIVE INHIBITION. ADDITIONALLY...THE HIGH-RES ARW AND NMM MODELS INFER SCATTERED AFTERNOON THUNDERSTORMS FROM EASTERN SISKIYOU COUNTY INTO MODOC AND SOUTHERN KLAMATH AND LAKE COUNTIES. IN SHORT...THIS SUPPORTS A FIRE WEATHER WATCH...FOUND AT RFWMFR. THE TRIGGER CONTINUES TO BE THE WEAKEST INGREDIENT IN THIS THUNDERSTORM RECIPE...BUT BELIEVE THE OTHER INGREDIENTS ARE STRONG ENOUGH TO ACT ON EVEN A WEAK TRIGGER. ONE NOTE IS THAT STORM MOTION WILL BE TO THE EAST AT ABOUT 15KT IN MODOC AND LAKE COUNTIES...LIMITING WETTING RAIN POTENTIAL THERE ASSOCIATED WITH THE STORMS. WEDNESDAY WILL BE SHARPLY COOLER OVER THE CWA...WITH TEMPERATURES DROPPING TO 5 TO 10 DEGREES BELOW NORMAL. THE DAY SHOULD START OUT CLOUDY IN MOST AREAS WEST OF THE CASCADES AS THE UPPER TROUGH LIFTS AND USHERS IN MARINE STRATUS ALL THE WAY TO THE CASCADE FOOTHILLS. CLOUDS WILL CLEAR OUT BY THE AFTERNOON AND BREEZY CONDITIONS ARE EXPECTED MOST AREAS. THUNDERSTORM CHANCES CONTINUE ON WEDNESDAY AFTERNOON FOR THE SOUTHEAST PORTION OF THE CWA...THOUGH SHOULD BE LIMITED IN COVERAGE DUE TO LESS MOISTURE AND INSTABILITY. ANOTHER COOL DAY ON THURSDAY WILL GIVE WAY TO WARMING CONDITIONS FRIDAY AND INTO THE WEEKEND AS TEMPERATURES REACH BACK UP TO NEAR NORMAL READINGS...UNDER THE INFLUENCE OF A BUILDING RIDGE OVER THE DESERT SW. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR ORZ624-625. CA...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY EVENING FOR CAZ281-284-285. PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM THIS AFTERNOON TO 5 AM PDT THURSDAY FOR PZZ356-376. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON TO 5 AM PDT THURSDAY FOR PZZ356-376. $$ BPN/FJB/NSK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
439 AM EDT MON JUL 20 2015 .SYNOPSIS... A PAIR OF COLD FRONTS WILL PUSH SOUTHEAST ACROSS THE REGION TONIGHT AND ON TUESDAY. HIGH PRESSURE WILL BUILD OVER PENNSYLVANIA DURING THE SECOND HALF OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 930 PM... HEAT ADVISORY FOR SE HAS ENDED. ONGOING CLUSTER OF SEVERE WEATHER ALONG I-80 CORRIDOR THIS MID EVENING LOOKS LIKE IT WILL GRADUALLY WEAKEN OVER NEXT FEW HOURS. WW443 CONTINUES FOR THIS REGION...BUT HAS BEEN SCALED BACK ALONG NORTHERN BORDER WHERE THREAT HAS ENDED. BEGAN TO TAPER POPS BACK GRADUALLY LATE THIS EVENING AND ESP OVERNIGHT...THOUGH THREAT FOR SHOWERS/POSS A TSTM WILL PERSIST UNTIL COLD FROPA. 6 PM... EARLY CONVECTION WHICH POPPED UP IN THE HEAT OVER THE CENTRAL MOUNTAINS HAVE DISSIPATED. OTHER THAN A FEW SPECKLES ELSEWHERE...THE ONLY GAME IN TOWN IS NOW THE STORMS OVER THE FAR NW. LOTS OF STORMS SEEM TO SPLIT AND LEAVE THE LEFT-MOVER AS THE STRONGER CELL. SO HAIL IS ALSO A THREAT WITH THE WIND DAMAGE STILL THE MAIN THREAT. HAIL MAY END UP MELTING DOWN SOME EVEN IF IT WAS LARGE ALOFT DUE TO HOT TEMPS AND DEEP WARM CLOUD DEPTH. TWEAKS MAINLY FOR TIMING AND PLACEMENT. PREV... SEVERE THUNDERSTORM WATCH #443 IS NOW IN EFFECT FOR THE NORTHERN HALF OF CENTRAL PA THROUGH 11 PM EDT. PRELIMINARY CELLS FIRING DUE TO DIURNAL DESTABILIZATION AND BOUNDARY LAYER THERMAL RIDGE PUSHING EAST OF MY AREA. HOTTEST DAY OF SUMMER THUS FAR IN PROGRESS WITH APPARENT TEMPS SURGING INTO THE 90S THROUGHOUT. HEAT INDICES WILL TOP OUT BETWEEN 100F AND 104F ACROSS THE SUSQ VALLEY. VERY WARM ALOFT WITH BOUNDARY LAYER CAPPING OF EARLIER TOWERS NOW DECREASING AS CIN ANALYSIS SHOWS DESTABLIZATION OCCURRING OVER LAKE ERIE AND NORTHWEST PA. JUST ONE HOUR AGO...ELEVATED HEAT SOURCE SHOWERS BRIEFLY SPROUTED OVER SOUTH MOUNTAIN BEFORE MOVING OFF THE TERRAIN AND QUICKLY DISSIPATING. SIMILAR SHOWERS TRYING TO GROW OVER PORTIONS OF THE CENTRAL MOUNTAINS...AND ARE NOW OVERCOMING THE CAP. HRRR DOES DEVELOP AND PROPAGATE THIS ISOLD TO SCT SHRA/TSRA AREA SIMILAR TO SAT EVENING ACTIVITY BEFORE DISSIPATING IT WITH THE DECREASE IN DIURNAL HEATING BY 00Z. MAIN ACTIVITY EXPECTED WITH APPROACHING SHORTWAVE/COLD FRONT FROM THE EASTERN GLAKS THIS EVENING THROUGH LATE TONIGHT. NO REAL CHANGES TO PREVIOUS THINKING...WITH NORTHERN AREAS STANDING THE GREATEST THREAT OF STRONG TO LOCALLY SEVERE STORMS...AS THE PARENT SHORTWAVE WILL LIFT WELL NORTH OF THE REGION THIS EVENING. FAR SOUTHEAST MAY BE HARD PRESSED TO RAIN FROM THIS FRONT AS A RESULT LATE TONIGHT...AS GREATER DISTANCE FROM THE WANING LG SCALE FORCING ACCOMPANIES FROPA FURTHER SOUTH. THUS TAPERING POPS TO THE SOUTHEAST WILL BE MAINTAINED. COOLER/DRIER AIR IN WAKE OF COLD FRONT SHOULD MAKE SOME INROADS ACROSS THE NW MTNS...WHERE LOWS IN THE L60S EXPECTED TONIGHT. THE REST OF CENTRAL PA WILL REMAIN IN MUGGY AIR MASS FOR ANOTHER NIGHT WITH LOWS BTWN 70-75F SOUTH OF I-80. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... STALLED OUT COLD FRONT NR THE MASON DIXON LINE WILL BE THE FOCUS FOR SCT PM CONVECTION ON MONDAY. ELSEWHERE...ARRIVAL OF LOW PWAT AIR ACROSS NORTHERN PA SHOULD ENSURE A DRY DAY. ENS MEAN 8H TEMPS ARE SUPPORTIVE OF HIGHS FROM THE L80S OVR THE N MTNS...TO THE L90S ACROSS THE LOWER SUSQ VALLEY. DID NOT CHANGE MUCH ON THIS PERIOD. DID GO WITH A DRY FCST FOR THE MORNING HOURS. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HARD TO SEE A LOT GOING ON AFTER THIS EVENING...DUE TO THE LACK OF SFC CONVERGENCE. DID GO WITH SOME CHC POPS LATER MONDAY INTO TUE. HIGHEST CHC ON TUE...AS SECONDARY FRONT DROPS SE. AFTER THIS...LOOKING AT MAINLY DRY WEATHER WED INTO FRIDAY. SOME MODELS LIKE THE GFS40 HAVE SOME SHOWERS IN THE SW ON THU. LEFT FCST DRY FOR NOW. MAIN CHANGE WAS TO LOWER TEMPS MORE FOR THE PERIOD WED INTO FRIDAY. MAIN FACTORS ARE LOWER 500 MB HEIGHTS ON THE MODELS LATELY ALSO THE TENDENCY FOR THE AIRMASS BEHIND COLD FRONTS TO BE COLDER THAN FCST LATELY. ALSO THE WET GROUND. MID SHIFT DID PUT SOME SHOWERS IN FOR THE FIRST PART OF THE WEEKEND. SOME MODELS SHOW VERY STRONG WARM ADVECTION AND DIRECTIONAL SHEAR INTO AT LEAST NW PA ON SUNDAY. EC NOT REALLY SHOWING MUCH OF THIS. FOR NOW...DID CARRY SHOWERS INTO SUNDAY. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... ISOLATED SHOWERS WITH AN EVEN RARER TSTM STILL IMPACTING CENTRAL PA EARLY THIS MORNING AHEAD OF AN APPROACHING COLD FRONT. BUT ACTIVITY SIGNIFICANTLY DIMINISHED SINCE THE EVENING HOURS. ATTENTION DURING THE PREDAWN HOURS WILL TURN TO DEVELOPMENT OF FOG/MIST AND CIG RESTRICTIONS. MOST LIKELY AREAS FOR FOG WILL BE ACROSS THE NORTHERN HALF WHERE RAIN OCCURRED /FROM KBFD-KUNV- KIPT/. LIGHT SW FLOW AHEAD OF THE APPROACHING COLD FRONT WILL ALSO BRING AN MVFR/IFR CLOUD DECK TO MAINLY WESTERN SECTIONS. THE SE SHOULD REMAIN VFR...WITH JUST A BIT OF MVFR FOG POSS RIGHT AROUND SUNRISE. EXPECT RESTRICTIONS TO IMPROVE BETWEEN 12-15Z. MONDAY WILL BRING MAINLY VFR CONDITIONS AS DRIER AIR WORKS IN FROM THE NW. BUT SLIGHT CHANCE FOR A SHOWER OR TSTM WILL REMAIN ALONG THE SOUTHERN TIER AND POSS VICINITY OF KMDT-KLNS WHERE DEWPOINTS REMAIN HIGH. WINDS WILL REMAIN WESTERLY AND PICK UP TO NEAR 10 MPH DURING THE DAY. OUTLOOK... TUE...ANOTHER COLD FRONT WILL BRING SCT SHOWERS/TSTMS. CIG RESTRICTIONS LIKELY NW HALF...PRIMARILY VFR SE. WED-FRI...MAINLY VFR. LOCAL A.M. FOG POSS. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DEVOIR/RXR NEAR TERM...DANGELO/DEVOIR/RXR SHORT TERM...DEVOIR/MARTIN LONG TERM...MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1003 PM CDT TUE JUL 21 2015 .UPDATE... STORMS DYING OFF AS DAYTIME HEATING SUBSIDES BUT ADDITIONAL DEVELOPMENT SHOWING UP ACROSS NORTHEAST AR ASSOCIATED WITH UPPER WAVE MAY AFFECT THE WEST/SOUTHWEST OVERNIGHT. DO NOT EXPECT TOO MUCH OUT OF THIS PRE-12Z WITH A WEAK WIND FIELD BEHIND. WILL LEAVE ONLY SMALL POPS IN AT THIS TIME THERE. WILL REMOVE FROM NORTHEAST ALL TOGETHER. NO CHANGES OVERWISE. && .PREV DISCUSSION... /ISSUED 724 PM CDT TUE JUL 21 2015/ AVIATION UPDATE... DIURNALLY DRIVEN ISOLATED SHOWERS/TSTORMS HAVE BEEN SKIRTING ALABAMA BORDER DURING THE AFTERNOON. THIS ACTIVITY ALL BUT DISSIPATED. RUC SHOWING SHORT WAVE NORTHERN ARKANSAS AT 00Z WILL WORK EAST NEXT FEW HOURS ACCOMPANIED BY TSTORMS. SCATTERED TSTORMS IN CENTRAL KENTUCKY SINKING SOUTH BUT APPEAR TO BE DIMINISHING AT THIS TIME. I KEPT ANY MENTION OF TSTORMS OUT OF THE TERMINAL FORECAST NEXT 24 HOURS BUT THINK BEST CHANCE WILL COME WEDNESDAY AFTERNOON. WILL TAKE CLOSER LOOK AT NEW MODEL DATA LATER THIS EVENING AND UPDATE TERMINALS IF NEED BE. DO EXPECT FOG IN THE OVERNIGHT HOURS AT ALL TERMINALS. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 90 73 88 71 / 20 20 30 50 CLARKSVILLE 88 71 86 70 / 10 10 30 40 CROSSVILLE 85 68 83 67 / 20 10 30 20 COLUMBIA 91 72 87 71 / 20 20 50 50 LAWRENCEBURG 92 72 87 71 / 30 20 60 50 WAVERLY 91 71 86 70 / 20 20 40 50 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 07
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
724 PM CDT TUE JUL 21 2015 .AVIATION UPDATE... DIURNALLY DRIVEN ISOLATED SHOWERS/TSTORMS HAVE BEEN SKIRTING ALABAMA BORDER DURING THE AFTERNOON. THIS ACTIVITY ALL BUT DISSIPATED. RUC SHOWING SHORT WAVE NORTHERN ARKANSAS AT 00Z WILL WORK EAST NEXT FEW HOURS ACCOMPANIED BY TSTORMS. SCATTERED TSTORMS IN CENTRAL KENTUCKY SINKING SOUTH BUT APPEAR TO BE DIMINISHING AT THIS TIME. I KEPT ANY MENTION OF TSTORMS OUT OF THE TERMINAL FORECAST NEXT 24 HOURS BUT THINK BEST CHANCE WILL COME WEDNESDAY AFTERNOON. WILL TAKE CLOSER LOOK AT NEW MODEL DATA LATER THIS EVENING AND UPDATE TERMINALS IF NEED BE. DO EXPECT FOG IN THE OVERNIGHT HOURS AT ALL TERMINALS. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ BOYD 01
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
335 PM CDT MON JUL 20 2015 .DISCUSSION... JUST NOW SEEING THE BEGINNINGS OF THE NEXT MCS WHICH IS EXPECTED TO MOVE OUR WAY TONIGHT. CONFIDENCE IS NOT REAL HIGH. HOWEVER...DEVELOPMENT OVER EASTERN MO IS SUPPORTED BY THE HRRR BUT THE MODELS TRANSFER THE BULK OF THE MOISTURE ON AN EASTWARD TRACK...PRIMARILY NORTH OF OUR AREA. AT ANY RATE...FOR THE FCST THIS EVENING...WILL ADHERE LARGELY TO THE LATEST RADAR SCANS AND INCLUDE POPS BASED ON TRENDS. OVERNIGHT HOWEVER...WILL NEED TO KEEP POPS A LITTLE ELEVATED ACROSS OUR NORTHWEST AREAS. AS FOR SEVERE POTENTIAL...OUR NW COUNTIES ARE STILL IN A SLIGHT RISK. NOT REALLY SEEING MUCH UPPER DIVERGENCE SUPPORT BUT LOW LEVEL FORCING WILL COMBINE WITH A 20 KT FLOW AT 850 TO PERHAPS MAKE THINGS INTERESTING. TUESDAY AND WEDNESDAY...MODEL DIFFERENCES DO ABOUND AS FAR AS THE SOUTHWARD INTRUSION OF THE DRY AIR GOES AS WELL AS THE SOUTHWARD EXTENT OF THE FRONTAL BOUNDARY. GFS IS MORE BULLISH BUT STILL...CAPES ARE RATHER HEFTY THE NEXT 2 AFTERNOONS ACROSS OUR SOUTH. OVERALL...MODELS HAVE BACKED OFF ON THE OVERALL CONVECTION CHANCES. I WILL MAKE A SLIGHT DOWNWARD TREND BUT GIVEN THE FACT THAT THE EURO AND NAM ARE MORE UNCERTAIN WITH THE FRONTS SOUTHWARD PROGRESS...LOW POPS WILL GENERALLY STILL REMAIN. FOR THE NEAR TERM TEMPS...MANY PLACES ARE CURRENTLY IN THE 100 TO 105 HEAT INDEX ZONE. WILL GO AHEAD AND ALLOW THE HEAT ADVISORY TO CONTINUE UNTIL 7 PM AS SCHEDULED. OTW...NUMERICAL MODELS ALL HINT TOWARD LOWER HUMIDITIES BEGINNING ON WEDNESDAY. TEMPS WILL BACK OFF A FEW DEGREES FOR BOTH HIGHS AND LOWS AS WE RETURN TO MORE NORMAL VALUES AND HUMIDITIES. IN THE EXT FCST...THE POTENTIALLY ACTIVE NW FLOW PATTERN WILL CONTINUE THU AND FRIDAY. OVER THE WEEKEND...HOWEVER...UPPER RIDGE OVER THE SOUTHERN PLAINS WILL STRENGTHEN. HEIGHTS WILL RISE OVER TN AND POPS WILL LOWER. WE WILL SEE A WARMING TREND WITH TEMPS BACK UP INTO THE 90S THROUGH MUCH OF THE EXTENDED BUT THE LOWER LEVEL GULF FETCH WILL NO LONGER BE IN TACT. THUS...A SOMEWHAT DRIER AND LESS HUMID TEMP REGIME IS EXPECTED. INSTEAD OF THE MID 70S DEWPOINTS...WE WILL BE LOOKING AT UPPER 60S TO NEAR 70 DEWPOINTS...WHICH IS A CONSIDERABLE DIFFERENCE. .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 76 93 72 90 / 30 30 20 30 CLARKSVILLE 73 91 69 86 / 50 30 20 20 CROSSVILLE 72 88 68 84 / 40 30 30 20 COLUMBIA 76 94 72 90 / 30 30 30 30 LAWRENCEBURG 75 94 72 90 / 20 40 30 40 WAVERLY 73 91 70 87 / 40 30 30 30 && .OHX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR TNZ005>009-023>030- 056>064-075-077-093>095. && $$ 21
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
346 AM CDT MON JUL 20 2015 .DISCUSSION... CURRENTLY...AT 3 AM AROUND THE MIDSOUTH TEMPERATURES RANGE FROM THE MID 70S IN THE EAST TO THE LOWER 80S IN THE WEST. CURRENT INFRARED SATELLITE IMAGERY DEPICTS CLOUDS MOVING INTO NORTHERN REACHES OF THE FA ASSOCIATED WITH ONGOING CONVECTION OVER SOUTHEAST MISSOURI...SOUTHERN ILLINOIS...AND WESTERN KENTUCKY. THIS ACTIVITY IS MARCHING TOWARD THE MIDSOUTH AND WILL LIKELY AFFECT NORTHERN COUNTIES THROUGH SUNRISE. H5 ANALYSIS DEPICTS A HIGH PRESSURE CENTER LOCATED OVER WEST TEXAS...AND THE CONTINUED WESTWARD MIGRATION OF THE FEATURE WILL ALLOW DAILY SHOWER AND THUNDERSTORM CHANCES TO RETURN TO THE REGION. A HEAT ADVISORY REMAINS IN EFFECT THROUGH 7 PM THIS EVENING WITH TEMPERATURES TOPPING OUT ONCE AGAIN IN THE UPPER 90S AT MOST LOCATIONS TODAY...LEADING TO HEAT INDICES IN EXCESS OF 105 DEGREES. UNCERTAINTY EXISTS IN REGARD TO THE ADVISORY AFTER THIS EVENING...AND THUS THE DAY SHIFT WILL DETERMINE EXACTLY WHERE AND FOR HOW LONG TO EXTEND. TEMPERATURES WILL COOL UNDER INCREASED CLOUD COVER AND CONVECTION THROUGHOUT THE WEEK...THOUGH AREAS PRIMARILY LOCATED IN NORTH MISSISSIPPI COULD SEE HEAT INDICES JUST NEAR CRITERIA AT LEAST THROUGH WEDNESDAY. WITH THE INFLUENCE OF THE RIDGE ABSENT FROM THE REGION...A COLD FRONT WILL BEGIN TO APPROACH THE REGION...LEADING TO AN INCREASE IN SHOWER AND THUNDERSTORM CHANCES. THESE CHANCES WILL GRADUALLY INCREASE FROM NORTH TO SOUTH AS WE ADVANCE THE WEEK WITH THE MIGRATION OF THE BOUNDARY SOUTH. TUESDAY THROUGH THURSDAY WILL HOLD THE BEST PRECIPITATION CHANCES THIS WEEK AS THE BOUNDARY REMAINS STATIONED IN THE VICINITY OF THE MIDSOUTH WITH SEVERAL SUBTLE IMPULSES ALOFT INTERACTING WITH THE FEATURE. A FEW STORMS COULD BE STRONG THIS WEEK WITH GUSTY WINDS AND HEAVY RAIN...PARTICULARLY DURING THE AFTERNOON AND EVENING HOURS WHEN THE GREATEST INSTABILITY IS REALIZED. ALONG WITH INCREASED PRECIPITATION CHANCES COMES A RELIEF FROM THE OPPRESSIVE HEAT...WITH TEMPERATURES RANGING FROM THE UPPER 80S TO MID 90S FOR MUCH OF THE WEEK AFTER MONDAY. CHANCES FOR PRECIPITATION WILL DECREASE LATE IN THE WEEK AND INTO THE WEEKEND WITH TEMPERATURES SLOWLY INCREASING AS MODELS HINT AT THE AMPLIFIED RIDGE BUILDING BACK INTO THE REGION. ZDM && .AVIATION... 06Z TAFS LATE EVENING RADAR TRENDS AND SHORT TERM MODEL DATA SUGGESTS THE SOUTHERN FRINGES OF TSRA COMPLEX IN SOUTHEAST MO MAY ENTER NORTHEAST AR AND NORTHWEST TN DURING THE OVERNIGHT. IT MAY BE CLOSE CALL IF THE HRRR IS CORRECT. NAM REMAINS FURTHER NORTH... KEEPING MKL AND JBR DRY OVERNIGHT WITH UPPER RIDGE RETROGRADING FURTHER ON MONDAY... ADDITIONAL AFTERNOON TSRA WILL BE POSSIBLE NEAR THE TN RIVER... POSSIBLY INTO THE MKL VICINITY. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS- MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN- TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR BENTON TN-CARROLL- CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN- HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON- MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1143 PM CDT SUN JUL 19 2015 .UPDATE... UPDATED FOR 06Z AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... /ISSUED 845 PM CDT SUN JUL 19 2015/ DISCUSSION... MINOR UPDATE MAINLY IN THE NORTHERN PORTION OF FORECAST AREA. INCREASED POPS DUE TO STORMS IN MISSOURI...WHICH THE HRRR BRINGS INTO THE MID-SOUTH OVERNIGHT. NAM ALSO HINTS AT SOME PRECIPITATION OVER AREA TONIGHT. HRRR IS MORE AGGRESSIVE AND MUCH MORE OF THE AREA COVERED. HOWEVER...ONLY RAISED POPS SLIGHTLY AND THUS ONLY NORTHERN PORTION HAVE HIGH ENOUGH POPS TO MENTION PRECIPITATION IN THE FORECAST. HAVE TO WATCH THIS CLOSELY. HEAT ADVISORY STILL CONTINUES FOR THROUGH TOMORROW. THIS IS BEGINNING TO LOOK LIKE A RARE EVENT FOR THE MID-SOUTH WITH CONSECUTIVE DAYS OF HEAT ADVISORIES...AT LEAST ACCORDING TO DATA FOUND THIS EVENING AT OFFICE...SEE CLIMATE SECTION FOR MORE DETAILS. TLSJR PREV DISCUSSION... /ISSUED 306 PM CDT SUN JUL 19 2015/ DISCUSSION...WATER VAPOR SATELLITE TRENDS THIS AFTERNOON PLACE AN UPPER LEVEL RIDGE OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY. MOST AREAS HAVE REMAINED RAIN FREE EXCEPT FOR A PORTION OF WEST TENNESSEE NEAR SAVANNAH AND EXTREME NORTHEAST MISSISSIPPI WHERE ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPED AND QUICKLY PUSHED OUT OF THE FORECAST AREA. VISIBLE SATELLITE TRENDS INDICATE MOSTLY SUNNY TO PARTLY SUNNY SKIES ACROSS THE MID SOUTH DUE TO THE DEVELOPMENT OF DIURNAL BASED CUMULUS FROM LATE MORNING. AS OF 2 PM CDT...TEMPERATURES ACROSS THE MID SOUTH ARE IN THE LOWER TO MIDDLE 90S AT MOST LOCATIONS. HEAT ADVISORY POTENTIAL THROUGH EARLY THIS WEEK AND INCREASED CONVECTIVE POTENTIAL CHANCES ARE THE CHALLENGES IN THIS AFTERNOON/S FORECAST ISSUANCE. AFTERNOON TEMPERATURES IN THE LOWER TO MIDDLE 90S COMBINED WITH SURFACE DEWPOINTS IN THE LOWER TO MIDDLE 70S HAS RESULTED IN HEAT INDEX READINGS REACHING OR EXCEEDING 105 DEGREES THIS AFTERNOON. SOME CLOUD COVER HAS TEMPORARILY DROPPED HEAT INDEX READINGS BELOW ADVISORY CRITERIA ACROSS PORTIONS OF THE MID SOUTH...BUT POTENTIAL EXISTS FOR THESE AREAS TO SEE VALUES AT OR ABOVE 105 DEGREES AGAIN BEFORE SUNSET. MODELS CONTINUE TO INDICATE AN UPPER LEVEL RIDGE AXIS HOLDING IN PLACE ACROSS MUCH OF THE MID SOUTH THIS EVENING BUT WILL WEAKEN ACROSS AREAS NEAR THE KENTUCKY/MISSOURI BORDER LATE TONIGHT AND NORTH OF I-40 ON MONDAY. SHEAR WILL CONTINUE TO REMAIN WEAK OVERALL AND THINK ANY CONVECTIVE ACTIVITY WILL BE TRIGGERED BY CONVECTIVE TEMPERATURES BEING REACHED...RESULTING IN THE DEVELOPMENT OF RATHER DISORGANIZED PULSE TYPE THUNDERSTORMS. TEMPERATURES AGAIN WILL BE HOT ON MONDAY AND HIGH SURFACE DEWPOINTS IN THE LOWER TO PERHAPS MIDDLE 70S WILL RESULT IN HEAT INDEX READINGS ONCE AGAIN REACHING OR EXCEEDING 105 DEGREES. THE HEAT ADVISORY WILL REMAIN IN EFFECT FOR THE ENTIRE MID SOUTH THROUGH AT LEAST 7 PM CDT MONDAY. BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS WILL ARRIVE FOR TUESDAY AS A WEAK COLD FRONT DROPS INTO THE LOWER MISSISSIPPI VALLEY. HEAT INDEX READINGS MAY ONCE AGAIN APPROACH/EXCEED 105 DEGREES AND THE CURRENT HEAT ADVISORY MAY ONCE AGAIN NEED TO BE EXTENDED IN TIME. WILL HOLD OFF FOR THE TIME BEING TO UNCERTAINTY RELATED TO CONVECTIVE COVERAGE AND ITS AFFECT ON TEMPERATURES. BEST CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH THURSDAY. LONG TERM MODELS INDICATE THE UPPER LEVEL RIDGE AXIS WILL TRY TO BUILD BACK IN ACROSS THE LOWER MISSISSIPPI VALLEY WITH THE BEST CHANCES FOR SHOWERS AND THUNDERSTORMS BEING SLIGHTLY EAST OF THE MID SOUTH TOWARDS NEXT WEEKEND. CJC && .CLIMATE... LOOKING AT DATA FROM 2004 TO TODAY WHEN THE MEMPHIS OFFICE ISSUED EITHER A HEAT ADVISORY OR EXCESSIVE HEAT WARNING. THE FOLLOWING TABLES SHOW THE TOP SIX NUMBER OF DAYS IN A ROW A ADVISORY OR WARNING WERE ISSUED. WE DON/T HAVE RECORDS OF HEAT INDEX VALUES FOR ALL DAYS ACROSS THE MID-SOUTH SO USED THE ADVISORIES AND WARNINGS. FOR ALL THE MID-SOUTH (THAT IS ANYWHERE IN THE MID-SOUTH) 19 DAYS - JULY 29 - AUGUST 16, 2010 13 DAYS - JULY 26 - AUGUST 8, 2011 11 DAYS - JULY 16 - JULY 26, 2010 11 DAYS - JULY 26 - AUGUST 5, 2008 9 DAYS - JULY 18 - JULY 26, 2012 8 DAYS - JULY 12 - JULY 19, 2015 /TODAY/ 8 DAYS - JULY 28 - AUGUST 5, 2012 8 DAYS - JUNE 18 - JUNE 25, 2010 8 DAYS - JULY 20 - JULY 27, 2005 WE SHOULD REACH THE TOP FIVE FOR THE AREA ON MONDAY. LOOKING SPECIFICALLY AT MEMPHIS /SHELBY COUNTY/ IT IS ALREADY IN THE TOP 5 FOR THE PAST 11 YEARS. FOR SHELBY COUNTY 11 DAYS - JULY 26 - AUGUST 5, 2008 10 DAYS - JULY 30 - AUGUST 8, 2011 10 DAYS - AUGUST 7 - AUGUST 16, 2010 9 DAYS - JULY 18 - JULY 26, 2012 8 DAYS - JULY 12 - JULY 19, 2015 /TODAY/ 8 DAYS - JULY 29 - AUGUST 5, 2010 8 DAYS - JUNE 18 - JUNE 25, 2010 && .AVIATION... 06Z TAFS LATE EVENING RADAR TRENDS AND SHORT TERM MODEL DATA SUGGESTS THE SOUTHERN FRINGES OF TSRA COMPLEX IN SOUTHEAST MO MAY ENTER NORTHEAST AR AND NORTHWEST TN DURING THE OVERNIGHT. IT MAY BE CLOSE CALL IF THE HRRR IS CORRECT. NAM REMAINS FURTHER NORTH... KEEPING MKL AND JBR DRY OVERNIGHT WITH UPPER RIDGE RETROGRADING FURTHER ON MONDAY... ADDITIONAL AFTERNOON TSRA WILL BE POSSIBLE NEAR THE TN RIVER... POSSIBLY INTO THE MKL VICINITY. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR ALCORN-BENTON MS-CALHOUN- CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL- MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-TALLAHATCHIE-TATE- TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA. TN...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR BENTON TN-CARROLL- CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN- HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON- MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1105 PM CDT SUN JUL 19 2015 .AVIATION AND MESOSCALE UPDATE...FOR 06Z FORECAST MESO CONVECTIVE SYSTEM HAS DEVELOPED IN SOUTHEAST MISSOURI. THIS IN AREA OF 700 MBAR THERMAL TROUGH AND SHORT WAVE AS CAN BE SEEN IN LATEST RUC RUN. HOW FAR SOUTHEAST THIS COMPLEX WILL GET IS IN QUESTION SINCE IT WILL BE MOVING INTO AN AREA THAT IS CURRENTLY CAPPED WITH TEMPS AROUND 11 DEGREE CELSIUS ALONG TENNESSEE/KENTUCKY BORDER UNDERNEATH WARM UPPER LEVEL ANTICYCLONE AND AROUND 14 DEGREES ACROSS A GOOD PART OF ARKANSAS INTO SOUTHWESTERN TENNESSEE. I DID NOTICE WHAT APPEARS TO BE A STATIONARY FRONT OR SOME TYPE OF BOUNDARY FEATURE STRUNG OUT FROM CENTRAL MISSOURI EASTWARD TO ALONG THE OHIO RIVER NORTH OF LOUISVILLE. NOT SURE HOW THIS FEATURE EVOLVED BUT IT IS DEFINITELY THERE. WINDS ARE LIGHT NORTHERLY NORTH OF THIS FEATURE AND LIGHT SOUTHERLY SOUTH. DEWPOINTS CONTINUE TO POOL ACROSS SOUTHEAST MISSOURI AND FAR WESTERN KENTUCKY AHEAD OF COMPLEX. H-TRIPLE-R WORKS COMPLEX DOWN INTO FAR NORTHWEST MIDDLE TENNESSEE AROUND 09Z THE PLAYS IT OUT TOWARD DAYBREAK. WILL BASE 06Z FORECASTS ON THIS SCENARIO AS IT SEEMS REASONABLE AT THIS TIME. && .OHX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR TNZ005>009-023>030- 056>064-075-077-093>095. && $$ BOYD 01
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1031 PM CDT TUE JUL 21 2015 .UPDATE... REMOVED POPS REST OF TONIGHT AS VERY LITTLE PRECIPITATION HAS OCCURRED THIS EVENING. REDEVELOPMENT OF SHOWERS AND TSTMS IS NOT EXPECTED THE REMAINDER OF TONIGHT. ANDRADE && .PREV DISCUSSION... /ISSUED 635 PM CDT TUE JUL 21 2015/ AVIATION... FOR THE 00Z TAFS...SOME POTENTIAL EXISTS FOR ISOLD TO PERHAPS SCT TSTMS TO AFFECT PARTS OF THE OK AND NRN TX PNHDLS THIS EVENING AND TONIGHT. HOWEVER...CONFIDENCE IS LOW AS TO WHETHER KGUY OR KDHT WILL BE IMPACTED SO HAVE OPTED TO OMIT THIS ELEMENT FROM THIS FCST CYCLE. WILL MONITOR TRENDS THIS EVENING FOR PSBL AMENDMENTS. SOME CONCERN FOR LOW CLOUDS LATER TONIGHT INTO EARLY WED MORNING. HAVE KEPT A SCT MVFR DECK FROM PREVIOUS FCST. ANDRADE PREV DISCUSSION... /ISSUED 432 PM CDT TUE JUL 21 2015/ DISCUSSION... PRIMARY FOCUS CONTINUES TO BE POTENTIAL FOR ADDITIONAL FLOODING TONIGHT AS MANY LOCATIONS ARE SATURATED FROM LAST NIGHT. 12Z SOUNDING SHOWS SIGNIFICANT CONVECTIVE OVERTURNING WITH VERY SHALLOW LOW LEVEL MOISTURE AND A MARKED DECREASE IN MOISTURE JUST ABOVE THAT THROUGHOUT THE LOW LEVELS. MID-HIGH LEVEL CLOUDS KEPT THE AREA FROM DESTABILIZATION AS SIGNIFICANTLY AS YESTERDAY AND ABSENCE OF ANY WELL DEFINED SURFACE BOUNDARIES HAS YIELDED A FAIRLY UNIFORM CUMULUS FIELD PER VISIBLE SATELLITE THIS AFTERNOON. SOME TERRAIN INDUCED CONVECTION IN NEW MEXICO HAS FORMED BUT OVERALL EXPANSIVENESS IS FAR LESS THAN YESTERDAY AT THIS TIME. WATER VAPOR LOOP AND RAP PV ANALYSIS SHOW ONE WAVE TRAVERSING THE PANHANDLES NOW WITH SUBSIDENCE FOLLOWING THIS FEATURE ALREADY OVERSPREADING THE WESTERN PORTION OF THE AREA. HAVE SIGNIFICANTLY LOWERED PRECIPITATION PROBABILITIES TONIGHT GIVEN TRENDS. MID LEVEL HEIGHTS RISE AS RIDGE ONCE AGAIN AMPLIFIES. THIS SHOULD LIMIT COVERAGE OF CONVECTION FOR MUCH OF THE WEEK. ISOLATED THUNDERSTORMS MAY OCCUR MAINLY OVER THE FAR NORTHWEST PORTION OF THE AREA. THE RIDGE WEAKENS AGAIN SUFFICIENTLY FOR AN INCREASE IN PRECIPITATION PROBABILITIES ESPECIALLY ACROSS THE NORTHERN PORTION OF THE AREA SATURDAY AND SUNDAY. BRB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
918 PM CDT TUE JUL 21 2015 .UPDATE... T-STORM ACTIVITY THIS EVENING HAS PRETTY MUCH BEEN LIMITED TO THE VICNITY OF THE FRONTAL ZONE ARCING NEWD FROM SOUTHWEST TEXAS TO NORTH TEXAS/RED RIVER VALLEY. MOST OF THE STORMS MOVING OFF THE HIGHER TERRAIN OF NEW MEXICO HAVE DIED OFF IN THE FACE OF COOLER TEMPERATURES/WEAKER INSTABILITY AND SOME SUBSIDENCE IN THE WAKE OF A SHORTWAVE BEHIND AN EXITING SHORTWAVE. KAMA 00 UTC SOUNDING SHOWED A PRETTY STOUT INVERSION AROUND 700 MB. DESPITE THIS...WE CAN/T COMPLETELY RULE OUT ISOLATED T-STORMS ALMOST ANYWHERE ACROSS THE FORECAST AREA TONIGHT DUE TO THE MOIST ATMOSPHERE AND SOME WEAK ASCENT ALONG THE REMNANT FRONTAL ZONE LIFTING NORTHWARD. WE HAVE UPDATED POPS AND WEATHER TO ACCOUNT FOR THESE TRENDS. && .PREV DISCUSSION... /ISSUED 629 PM CDT TUE JUL 21 2015/ AVIATION... THE MAIN AVIATION CONCERN IS THE POSSIBILITY OF TSRA IN THE VICINITY OF ALL TERMINALS THROUGH ABOUT 07 OR 08 UTC. AT THIS TIME...CONFIDENCE IS TOO LOW TO PINPOINT A PARTICULAR TIME OR AREA SO WE KEPT THE MENTION OUT OF THE TAF. LIGHT AND VARIABLE SURFACE WINDS WILL GRADUALLY COME AROUND TO THE S-SW AND INCREASE ON WEDNESDAY. THUNDERSTORMS MAY BE A CONCERN AT SOME TERMINALS WEDNESDAY AFTERNOON. PREV DISCUSSION... /ISSUED 315 PM CDT TUE JUL 21 2015/ SHORT TERM... MORE RAIN IS EXPECTED AGAIN LATER THIS AFTERNOON AND EVENING FOR WEST TEXAS...THIS TIME WITH A BIT MORE COVERAGE THAN LAST NIGHT IF THE FORECAST PANS OUT AS EXPECTED. MODELS PRE-12Z WERE VERY SKEPTICAL AND DIFFERED GREATLY ON WHERE AND WHEN CONVECTION WOULD OCCUR LATER TODAY. WHILE SOME QUESTIONS STILL REMAIN...MOST MODELS MINUS THE HRRR HAVE COME INTO AGREEMENT THAT CONVECTION SHOULD SPREAD FARTHER SOUTH AND EAST THAN YESTERDAY AFTERNOON. THE 12Z NAM SEEMED TO HAVE AT FIRST GLANCE THE BEST HANDLE ON THE FORECAST AS IT PICKED UP ON AN AREA OF LIFT OVER SOUTH-CENTRAL NM WHICH STARTED TO SHOW UP ON WV JUST AFTER 13Z. THE AREA OF LIFT HAS SINCE ENHANCED FURTHER AND HAS AIDED IN THE DEVELOPMENT OF EASTWARD PROPAGATING THUNDERSTORMS JUST EAST OF RUIDOSO NM. THESE STORMS SHOULD GRADUALLY MAKE THEIR WAY TOWARDS THE TX/NM STATE LINE BY THE LATE AFTERNOON/EARLY EVENING. ANOTHER AREA OF INTEREST FOR SHOWER AND THUNDERSTORM DEVELOPMENT IS A WESTWARD PROPAGATING SURFACE BOUNDARY ACROSS THE WESTERN THIRD OF THE FA. HIGHER RES MODELS...EVEN THE HRRR TO AN EXTENT...HAVE HINTED AT CONVECTIVE DEVELOPMENT ALONG THIS BOUNDARY WITHIN THE NEXT FEW HOURS AS MLCAPE INCREASES TO AROUND 1500 J/KG. THE AMOUNT OF CAPE THAT WILL BECOME AVAILABLE WILL DEPEND ON HOW MUCH ADDITIONS SURFACE HEATING CAN BE ACHIEVED AS TEMPS ARE COOLER THAN EXPECTED THIS AFTERNOON DUE TO CLOUD COVER THAT LINGERED INTO MID DAY. THE MAIN THREAT...AS IS USUALLY OUT HERE IN THESE PARTS...FROM CONVECTION WOULD BE STRONG TO POSSIBLY MARGINALLY SEVERE WINDS ASSOCIATED WITH DOWNBURSTS. HEAVY RAIN WILL ALSO BE A VALID THREAT AS WAS SEEN YESTERDAY EVENING. RAIN CHANCES WILL DIMINISH OVERNIGHT AS THE ATMOSPHERE COOLS AND STABILIZES. THE RIDGE WILL SLOWLY PUSH BACK INTO THE REGION MAKING WAY FOR HEIGHT RISES TOMORROW WHICH WILL GREATLY DECREASE STORM CHANCES ACROSS THE FA TOMORROW AFTERNOON. THE BEST CHANCES WILL BE IN OUR WESTERN ZONES WHICH WILL BE LOCATED NEAR THE WESTERN EDGE OF THE RIDGE. HIGH TEMPS TOMORROW WILL BE DEPENDENT UPON CONVECTIVE COVERAGE TONIGHT WHICH COULD COOL TEMPS BY SEVERAL DEGREES. FOR NOW MID 90S ON THE CAPROCK/UPPER 90S ACROSS THE ROLLING PLAINS WILL BE MAINTAINED. ALDRICH LONG TERM... CHANCES OF PRECIPITATION WILL BE FLEETING BY THURSDAY AFTERNOON ON THE WESTERN EDGE OF AN UPPER LEVEL RIDGE MOVING OVERHEAD. HEIGHT RISES WILL LIKELY SQUASH ANY CONVECTION LOCALLY. AFTERNOON/EVENING STORMS ARE STILL LIKELY ACROSS NEW MEXICO WITHIN SURFACE TROUGHING WELL WEST OF THE REGION. THERE IS SOME CHANCE BUT VERY LITTLE OF ANY STORMS BEING ABLE TO CROSS STATE LINES THROUGH EARLY NEXT WEEK. LATEST MOS GUIDANCE HAS CONTINUED ITS WARM BIAS ON MAX TEMPERATURES AND WILL CONTINUE TO FORECAST BELOW MOS...CLOSER TO BIAS CORRECTED GUIDANCE. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 90 67 94 / 30 20 20 20 TULIA 66 92 69 95 / 30 10 20 10 PLAINVIEW 68 91 70 94 / 20 10 20 0 LEVELLAND 68 93 71 95 / 20 20 20 10 LUBBOCK 72 94 72 97 / 20 20 10 0 DENVER CITY 69 94 70 95 / 30 20 20 20 BROWNFIELD 69 94 71 96 / 20 20 20 0 CHILDRESS 73 98 75 101 / 20 10 10 0 SPUR 70 94 73 96 / 20 10 10 0 ASPERMONT 73 98 76 101 / 30 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33/6
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
635 PM CDT TUE JUL 21 2015 .AVIATION... FOR THE 00Z TAFS...SOME POTENTIAL EXISTS FOR ISOLD TO PERHAPS SCT TSTMS TO AFFECT PARTS OF THE OK AND NRN TX PNHDLS THIS EVENING AND TONIGHT. HOWEVER...CONFIDENCE IS LOW AS TO WHETHER KGUY OR KDHT WILL BE IMPACTED SO HAVE OPTED TO OMIT THIS ELEMENT FROM THIS FCST CYCLE. WILL MONITOR TRENDS THIS EVENING FOR PSBL AMENDMENTS. SOME CONCERN FOR LOW CLOUDS LATER TONIGHT INTO EARLY WED MORNING. HAVE KEPT A SCT MVFR DECK FROM PREVIOUS FCST. ANDRADE && .PREV DISCUSSION... /ISSUED 432 PM CDT TUE JUL 21 2015/ DISCUSSION... PRIMARY FOCUS CONTINUES TO BE POTENTIAL FOR ADDITIONAL FLOODING TONIGHT AS MANY LOCATIONS ARE SATURATED FROM LAST NIGHT. 12Z SOUNDING SHOWS SIGNIFICANT CONVECTIVE OVERTURNING WITH VERY SHALLOW LOW LEVEL MOISTURE AND A MARKED DECREASE IN MOISTURE JUST ABOVE THAT THROUGHOUT THE LOW LEVELS. MID-HIGH LEVEL CLOUDS KEPT THE AREA FROM DESTABILIZATION AS SIGNIFICANTLY AS YESTERDAY AND ABSENCE OF ANY WELL DEFINED SURFACE BOUNDARIES HAS YIELDED A FAIRLY UNIFORM CUMULUS FIELD PER VISIBLE SATELLITE THIS AFTERNOON. SOME TERRAIN INDUCED CONVECTION IN NEW MEXICO HAS FORMED BUT OVERALL EXPANSIVENESS IS FAR LESS THAN YESTERDAY AT THIS TIME. WATER VAPOR LOOP AND RAP PV ANALYSIS SHOW ONE WAVE TRAVERSING THE PANHANDLES NOW WITH SUBSIDENCE FOLLOWING THIS FEATURE ALREADY OVERSPREADING THE WESTERN PORTION OF THE AREA. HAVE SIGNIFICANTLY LOWERED PRECIPITATION PROBABILITIES TONIGHT GIVEN TRENDS. MID LEVEL HEIGHTS RISE AS RIDGE ONCE AGAIN AMPLIFIES. THIS SHOULD LIMIT COVERAGE OF CONVECTION FOR MUCH OF THE WEEK. ISOLATED THUNDERSTORMS MAY OCCUR MAINLY OVER THE FAR NORTHWEST PORTION OF THE AREA. THE RIDGE WEAKENS AGAIN SUFFICIENTLY FOR AN INCREASE IN PRECIPITATION PROBABILITIES ESPECIALLY ACROSS THE NORTHERN PORTION OF THE AREA SATURDAY AND SUNDAY. BRB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
629 PM CDT TUE JUL 21 2015 .AVIATION... THE MAIN AVIATION CONCERN IS THE POSSIBILITY OF TSRA IN THE VICINITY OF ALL TERMINALS THROUGH ABOUT 07 OR 08 UTC. AT THIS TIME...CONFIDENCE IS TOO LOW TO PINPOINT A PARTICULAR TIME OR AREA SO WE KEPT THE MENTION OUT OF THE TAF. LIGHT AND VARIABLE SURFACE WINDS WILL GRADUALLY COME AROUND TO THE S-SW AND INCREASE ON WEDNESDAY. THUNDERSTORMS MAY BE A CONCERN AT SOME TERMINALS WEDNESDAY AFTERNOON. && .PREV DISCUSSION... /ISSUED 315 PM CDT TUE JUL 21 2015/ SHORT TERM... MORE RAIN IS EXPECTED AGAIN LATER THIS AFTERNOON AND EVENING FOR WEST TEXAS...THIS TIME WITH A BIT MORE COVERAGE THAN LAST NIGHT IF THE FORECAST PANS OUT AS EXPECTED. MODELS PRE-12Z WERE VERY SKEPTICAL AND DIFFERED GREATLY ON WHERE AND WHEN CONVECTION WOULD OCCUR LATER TODAY. WHILE SOME QUESTIONS STILL REMAIN...MOST MODELS MINUS THE HRRR HAVE COME INTO AGREEMENT THAT CONVECTION SHOULD SPREAD FARTHER SOUTH AND EAST THAN YESTERDAY AFTERNOON. THE 12Z NAM SEEMED TO HAVE AT FIRST GLANCE THE BEST HANDLE ON THE FORECAST AS IT PICKED UP ON AN AREA OF LIFT OVER SOUTH-CENTRAL NM WHICH STARTED TO SHOW UP ON WV JUST AFTER 13Z. THE AREA OF LIFT HAS SINCE ENHANCED FURTHER AND HAS AIDED IN THE DEVELOPMENT OF EASTWARD PROPAGATING THUNDERSTORMS JUST EAST OF RUIDOSO NM. THESE STORMS SHOULD GRADUALLY MAKE THEIR WAY TOWARDS THE TX/NM STATE LINE BY THE LATE AFTERNOON/EARLY EVENING. ANOTHER AREA OF INTEREST FOR SHOWER AND THUNDERSTORM DEVELOPMENT IS A WESTWARD PROPAGATING SURFACE BOUNDARY ACROSS THE WESTERN THIRD OF THE FA. HIGHER RES MODELS...EVEN THE HRRR TO AN EXTENT...HAVE HINTED AT CONVECTIVE DEVELOPMENT ALONG THIS BOUNDARY WITHIN THE NEXT FEW HOURS AS MLCAPE INCREASES TO AROUND 1500 J/KG. THE AMOUNT OF CAPE THAT WILL BECOME AVAILABLE WILL DEPEND ON HOW MUCH ADDITIONS SURFACE HEATING CAN BE ACHIEVED AS TEMPS ARE COOLER THAN EXPECTED THIS AFTERNOON DUE TO CLOUD COVER THAT LINGERED INTO MID DAY. THE MAIN THREAT...AS IS USUALLY OUT HERE IN THESE PARTS...FROM CONVECTION WOULD BE STRONG TO POSSIBLY MARGINALLY SEVERE WINDS ASSOCIATED WITH DOWNBURSTS. HEAVY RAIN WILL ALSO BE A VALID THREAT AS WAS SEEN YESTERDAY EVENING. RAIN CHANCES WILL DIMINISH OVERNIGHT AS THE ATMOSPHERE COOLS AND STABILIZES. THE RIDGE WILL SLOWLY PUSH BACK INTO THE REGION MAKING WAY FOR HEIGHT RISES TOMORROW WHICH WILL GREATLY DECREASE STORM CHANCES ACROSS THE FA TOMORROW AFTERNOON. THE BEST CHANCES WILL BE IN OUR WESTERN ZONES WHICH WILL BE LOCATED NEAR THE WESTERN EDGE OF THE RIDGE. HIGH TEMPS TOMORROW WILL BE DEPENDENT UPON CONVECTIVE COVERAGE TONIGHT WHICH COULD COOL TEMPS BY SEVERAL DEGREES. FOR NOW MID 90S ON THE CAPROCK/UPPER 90S ACROSS THE ROLLING PLAINS WILL BE MAINTAINED. ALDRICH LONG TERM... CHANCES OF PRECIPITATION WILL BE FLEETING BY THURSDAY AFTERNOON ON THE WESTERN EDGE OF AN UPPER LEVEL RIDGE MOVING OVERHEAD. HEIGHT RISES WILL LIKELY SQUASH ANY CONVECTION LOCALLY. AFTERNOON/EVENING STORMS ARE STILL LIKELY ACROSS NEW MEXICO WITHIN SURFACE TROUGHING WELL WEST OF THE REGION. THERE IS SOME CHANCE BUT VERY LITTLE OF ANY STORMS BEING ABLE TO CROSS STATE LINES THROUGH EARLY NEXT WEEK. LATEST MOS GUIDANCE HAS CONTINUED ITS WARM BIAS ON MAX TEMPERATURES AND WILL CONTINUE TO FORECAST BELOW MOS...CLOSER TO BIAS CORRECTED GUIDANCE. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 90 67 94 / 40 20 20 20 TULIA 66 92 69 95 / 40 10 20 10 PLAINVIEW 68 91 70 94 / 40 10 20 0 LEVELLAND 68 93 71 95 / 30 20 20 10 LUBBOCK 72 94 72 97 / 30 20 10 0 DENVER CITY 69 94 70 95 / 30 20 20 20 BROWNFIELD 69 94 71 96 / 30 20 20 0 CHILDRESS 73 98 75 101 / 40 10 10 0 SPUR 70 94 73 96 / 30 10 10 0 ASPERMONT 73 98 76 101 / 20 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33
AREA FORECAST DISCUSSION
NWS AMARILLO TX
242 PM CDT MON JUL 20 2015 .DISCUSSION... LATEST WATER VAPOR CHANNEL LOOP AND GOES DERIVED TPW SHOWS ANOMALOUS MOISTURE FLOWING NORTHWARD ACROSS EASTERN NEW MEXICO ON THE WESTERN EDGE OF UPPER RIDGE. 12Z SOUNDINGS CONFIRM THIS WITH A SIGNIFICANT INCREASE IN PWAT FROM 00Z LAST NIGHT (1.47 VS 0.82 INCHES). THIS IS APPROACHING 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY. DOWNSTREAM...A SHORTWAVE AND EXTENSIVE CONVECTION CONTINUES TO MOVE EASTWARD OUT OF THE CENTRAL PLAINS TOWARD THE MIDDLE MISSISSIPPI VALLEY WITH WEAK SUBSIDENCE EVIDENT BEHIND IT. VISIBLE SATELLITE REVEALS SOME MID-HIGH LEVEL CLOUDS LEFT IN THE WAKE OF OVERNIGHT CONVECTION AND THIS COULD POTENTIALLY LIMIT DIABATIC HEATING SOME THIS AFTERNOON WITH A TREND TOWARD PARTIAL CLEARING IN THE FAR SOUTH TEXAS PANHANDLE. SUBJECTIVE SURFACE ANALYSIS AT 18Z SHOWS A WEAK COLD FRONT/COMPOSITE OUTFLOW ORIENTED NORTHEAST TO SOUTHWEST FROM NEAR WHEELER TO JUST SOUTH OF CANYON. STORMS HAVE ALREADY FORMED NEAR CLOVIS AND CU/TCU HAS RECENTLY FORMED NEAR THIS BOUNDARY FURTHER EAST ACROSS THE FAR SOUTHERN PORTION OF OUR AREA. THIS SHOULD BE THE INITIAL FOCUS WITH MORE WIDESPREAD CONVECTION OCCURRING LATER THIS EVENING. THE TENDENCY OF MID LEVEL HEIGHTS WILL BE TO FALL SLIGHTLY AS UPPER RIDGE DEAMPLIFIES AND THIS SHOULD SUPPORT GREATER COVERAGE OF CONVECTION THAN HAS BEEN SEEN IN PREVIOUS DAYS. PRESENCE OF ANOMALOUS MOISTURE COMBINED WITH SLOW STORM MOTIONS RAISES CONCERN FOR FLASH FLOODING. FLASH FLOOD GUIDANCE IS AT OR ABOVE CURRENT QPF OUTPUT FROM MOST GUIDANCE. IN THE ABSENCE OF A WELL DEFINED SHORTWAVE TO FOCUS DEVELOPMENT BELIEVE THAT THE IMPACTS WOULD BE LOCALIZED. SOME OF THE SHORT RANGE HI-RES GUIDANCE AMOUNTS ARE MORE AGGRESSIVE BUT THERE IS SOME QUESTION ABOUT HOW MUCH OF THIS IS INFLUENCED BY THE BAD AWOS OBSERVATION AT PLAINVIEW/KPVW. THIS IS GETTING INTO THE RAP AND HAS CONSISTENTLY RESULTED IN A SPURIOUS 7000+ CAPE BULLSEYE IN THE SOUTH TEXAS PANHANDLE THE LAST SEVERAL DAYS. CAM GUIDANCE NESTED WITHIN THE RAP SUCH AS THE HRRR MAY BE EXAGGERATED WITH CONVECTIVE COVERAGE AND QPF AS A RESULT. SEVERE THUNDERSTORMS ARE A SECONDARY CONCERN TODAY ALTHOUGH DEEP LAYER SHEAR SHOULD BE TOO WEAK TO SUPPORT SUSTAINED UPDRAFTS. SEVERE EPISODES SHOULD BE BRIEF AND MARGINAL. MID LEVEL LAPSE RATES ARE NOT PARTICULARLY STEEP WHICH IS TYPICAL FOR THIS MONSOON PATTERN BUT ARE STEEP ENOUGH TO SUPPORT AROUND 1000 J/KG CAPE IN THE HAIL GROWTH ZONE. ISOLATED OCCURRENCES OF MARGINALLY SEVERE HAIL ARE POSSIBLE BUT MODERATE INSTABILITY AND WEAK SHEAR SUPPORTING FAIRLY INTENSE BUT VERTICAL UPDRAFTS WITH WATER LOADING BENEATH STEEPENING LOW LEVEL LAPSE RATES SHOULD SUPPORT PRIMARILY A WIND THREAT FROM BRIEF DOWNBURSTS LATE THIS AFTERNOON THROUGH AT LEAST MID EVENING. OVERNIGHT...WEAK ASCENT IS DEPICTED BY THE MODELS ON THE 315K SURFACE WHICH IS FAIRLY MOIST AND THIS SHOULD BE ENOUGH TO SUSTAIN CHANCES FOR CONVECTION INTO THE NIGHT AND IN A WEAKENED STATE PROBABLY EVEN INTO THE MORNING HOURS ESPECIALLY ACROSS THE EAST. SIMILAR CHALLENGES TO TODAY ARE EXPECTED TOMORROW WITH OVERNIGHT CONVECTION AND MESOSCALE BOUNDARIES/RESIDUAL CLOUDS MAKING SPATIAL AND TEMPORAL DETAILS UNCLEAR AT THIS POINT. FORECAST CONFIDENCE SHOULD INCREASE LATER TONIGHT AND BY MORNING AS WE MONITOR HOW EVENING/OVERNIGHT CONVECTION EVOLVES. STARTING WEDNESDAY MID LEVEL HEIGHTS RISE AS UPPER HIGH BUILDS NORTH/NORTHWESTWARD ONCE AGAIN RESULTING IN DRY WEATHER AND WARMER TEMPERATURES THROUGH AT LEAST THE END OF THE WEEK. TOWARD SATURDAY MEDIUM RANGE GUIDANCE CONSENSUS IS FOR RIDGE FLATTENS AGAIN AND MEAN WEST-NORTHWESTERLY FLOW MAY BE ENOUGH FOR CONVECTION TO MOVE INTO AT LEAST WESTERN AND NORTHERN SECTIONS. BRB && .PRELIMINARY POINT TEMPS/POPS... AMARILLO TX 89 66 82 66 91 / 40 60 50 30 10 BEAVER OK 91 68 78 66 91 / 30 60 60 50 20 BOISE CITY OK 84 63 79 62 92 / 30 60 60 40 20 BORGER TX 91 70 82 69 94 / 30 60 60 40 20 BOYS RANCH TX 89 67 84 67 95 / 40 60 60 30 20 CANYON TX 91 66 84 65 92 / 40 60 50 30 10 CLARENDON TX 95 69 85 68 94 / 30 60 50 30 10 DALHART TX 86 65 82 65 94 / 40 60 60 30 20 GUYMON OK 91 67 80 65 93 / 30 60 60 50 20 HEREFORD TX 92 66 86 66 92 / 40 60 50 30 20 LIPSCOMB TX 94 69 79 67 93 / 30 60 60 50 20 PAMPA TX 90 66 79 65 91 / 30 60 60 40 10 SHAMROCK TX 96 70 85 68 95 / 30 60 50 40 10 WELLINGTON TX 98 71 89 69 97 / 20 50 50 30 10 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 17
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AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
134 PM EDT MON JUL 20 2015 .SYNOPSIS... A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS HUMID AND COOLER AIR BEHIND THE BOUNDARY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM EDT MONDAY... THE FORECAST UPDATE FOR THIS AFTERNOON WILL REFLECT A DECREASE IN PRECIPITATION CHANCES ACROSS THE AREA UNTIL LATER THIS AFTERNOON. THE NEWLY ARRIVED 12Z/8AM NAM AND GFS SUPPORT WHAT THE MESO-SCALE MODELS HAVE BEEN HINTING AT...NAMELY LESS COVERAGE OF SHOWERS AND STORMS TODAY UNTIL LATER IN THE AFTERNOON...WITH THE GREATEST CONCENTRATION OVER THE FAR SOUTHWEST PORTION OF THE AREA. THIS APPEARS REASONABLE GIVEN OUR MOST RECENT RADAR TRENDS OF VERY LITTLE IN THE WAY OF SHOWERS ACROSS THE REGION...WITH NO THUNDERSTORMS CURRENTLY. FOR HIGH TEMPERATURES...HAVE MADE ONLY SMALL CHANGES TO THE ONGOING FORECAST. THE BIGGEST ADJUSTMENT WAS A SLIGHT LOWERING OF TEMPERATURES ACROSS THE NORTHERN MOUNTAINS OF NORTH CAROLINA WHERE SHOWERS WERE PERSISTENT THROUGH THE MORNING...AND LINGERING CLOUD COVER WILL HELP SLOW THE RISE OF TEMPERATURES THIS AFTERNOON. AS OF 955 AM EDT MONDAY... SHOWERS ACROSS THE AREA ARE OCCURRING IN TWO DISTINCT AREAS. THERE ARE WEAK AND ISOLATED SHOWERS HEADING EASTWARD THROUGH PARTS OF BATH AND ALLEGHANY COUNTIES OF VIRGINIA. THERE ARE MORE SUBSTANTIAL SHOWERS...AND A FEW THUNDERSTORMS...HEADING SOUTHEAST THROUGH THE NORTHERN MOUNTAINS OF NORTH CAROLINA FROM NORTHEAST TENNESSEE. COVERAGE WILL CONTINUE TO BE MINIMAL THROUGH THE REMAINDER OF THE MORNING HOURS AND ALSO THE EARLY AFTERNOON. LOOK FOR COVERAGE IN INCREASE ONCE WE REACH THE MID AFTERNOON...AND CONTINUE INTO THE EVENING HOURS. NO NOTABLE CHANGES HAVE BEEN MADE TO THE FORECAST HIGH TEMPERATURES. HOWEVER...SOME MINOR ADJUSTMENTS WERE MADE TO THE HOURLY TEMPERATURES THROUGH THE NEXT FEW HOURS BASED UPON CURRENT OBSERVATIONS AND EXPECTED TRENDS. AS OF 400 AM EDT MONDAY... 500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN BEFORE 12Z/8AM. WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE. WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME. MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM TEMPERATURES TODAY AND LOWS TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 AM EDT MONDAY... A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA- LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE. MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY 501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS. TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS SOUTH. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 350 PM EDT SUNDAY... BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF THE CWA...ESPECIALLY THE NW NC MOUNTAINS. THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE CONVECTION WITH IT. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 130 PM EDT MONDAY... CURRENTLY...ALL TAF SITES ALONG AND EAST OF THE BLUE RIDGE ARE HOLDING WITH VFR CONDITIONS...WHILE KLWB/KBLF CONTINUE TO FLIRT WITH THE VFR/MVFR LINE. CEILING HEIGHTS ARE EXPECTED TO CONTINUE TO CLIMB INTO VFR CATEGORIES THROUGH THE AFTERNOON HOURS. UPPER-LEVEL ENERGY WILL CROSSES THE AREA...AS A COLD FRONT SINKS TOWARD THE WV/VA LINE THIS AFTERNOON. REMOVED VCTS FROM ALL SITES EXCEPT KBLF DUE TO A DROP EXPECTED PRECIPITATION COVERAGE...IN PART TO EARLY MORNING SHOWER ACTIVITY ACROSS THE RIVER VALLEYS OF VA AND HIGHLANDS OF NC. NEAR-TERM MODELS TEND TO AGREE..WITH LITTLE TO NO INITIATION EXPECTED THROUGH 00Z TONIGHT. THIS MAY NEED AMENDING BASED ON FUTURE RADAR TRENDS...ESPECIALLY IF HEATING BECOMES ENOUGH FOR SPOTTY INITIATION LATER THIS AFTERNOON. EXPECT HIGHER PROBABILITY OF PRECIPITATION AND POTENTIAL STORM/LTG FORMATION MAINLY IN THE FAR WEST. LOWER CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE CHANCE OF PRECIPITATION FROM THE FORECAST AFTER 02Z/10PM AT KBLF. BR/FG FORMATION WILL BE WIDELY SCATTERED...AND LIKELY DEPENDENT ON THE OCCURRENCE OF RAINFALL...AND RESIDUAL CLOUDS TUESDAY AM. KEPT BR/FG FORMATION AT KLWB AND BR AT KBLF WITH MEDIUM CONFIDENCE. THE REMAINDER OF THE SITES HAVE BEEN LEFT OFF DUE TO THE LIKELIHOOD OF AN AM MID-DECK ALONG WITH LOW MON EVENING POPS. THIS MAY NEED TO BE AMENDED BASED ON RAINFALL AMOUNTS EXPERIENCED. EXTENDED AVIATION DISCUSSION... MORE WIDESPREAD THUNDERSTORM FORMATION WILL OCCUR ON TUESDAY... AS A REINFORCED FRONT SINKS SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT LAKES AND NORTHEAST UNITED STATES. A BIT CONCERNED WITH THE TIMING OF THE DRY-AIR BEHIND THE FRONT...WHICH SOME MODELS BRING INTO THE AREA WELL BEFORE PEAK-HEATING...WHICH COULD GREATLY DIMINISH COVERAGE AND SEVERITY OF PRECIPITATION AND CONVECTION. THIS FRONT SINKS SOUTH OF THE AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...DS/JM AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1251 PM EDT MON JUL 20 2015 .SYNOPSIS... A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS HUMID AND COOLER AIR BEHIND THE BOUNDARY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1245 PM EDT MONDAY... THE FORECAST UPDATE FOR THIS AFTERNOON WILL REFLECT A DECREASE IN PRECIPITATION CHANCES ACROSS THE AREA UNTIL LATER THIS AFTERNOON. THE NEWLY ARRIVED 12Z/8AM NAM AND GFS SUPPORT WHAT THE MESO-SCALE MODELS HAVE BEEN HINTING AT...NAMELY LESS COVERAGE OF SHOWERS AND STORMS TODAY UNTIL LATER IN THE AFTERNOON...WITH THE GREATEST CONCENTRATION OVER THE FAR SOUTHWEST PORTION OF THE AREA. THIS APPEARS REASONABLE GIVEN OUR MOST RECENT RADAR TRENDS OF VERY LITTLE IN THE WAY OF SHOWERS ACROSS THE REGION...WITH NO THUNDERSTORMS CURRENTLY. FOR HIGH TEMPERATURES...HAVE MADE ONLY SMALL CHANGES TO THE ONGOING FORECAST. THE BIGGEST ADJUSTMENT WAS A SLIGHT LOWERING OF TEMPERATURES ACROSS THE NORTHERN MOUNTAINS OF NORTH CAROLINA WHERE SHOWERS WERE PERSISTENT THROUGH THE MORNING...AND LINGERING CLOUD COVER WILL HELP SLOW THE RISE OF TEMPERATURES THIS AFTERNOON. AS OF 955 AM EDT MONDAY... SHOWERS ACROSS THE AREA ARE OCCURRING IN TWO DISTINCT AREAS. THERE ARE WEAK AND ISOLATED SHOWERS HEADING EASTWARD THROUGH PARTS OF BATH AND ALLEGHANY COUNTIES OF VIRGINIA. THERE ARE MORE SUBSTANTIAL SHOWERS...AND A FEW THUNDERSTORMS...HEADING SOUTHEAST THROUGH THE NORTHERN MOUNTAINS OF NORTH CAROLINA FROM NORTHEAST TENNESSEE. COVERAGE WILL CONTINUE TO BE MINIMAL THROUGH THE REMAINDER OF THE MORNING HOURS AND ALSO THE EARLY AFTERNOON. LOOK FOR COVERAGE IN INCREASE ONCE WE REACH THE MID AFTERNOON...AND CONTINUE INTO THE EVENING HOURS. NO NOTABLE CHANGES HAVE BEEN MADE TO THE FORECAST HIGH TEMPERATURES. HOWEVER...SOME MINOR ADJUSTMENTS WERE MADE TO THE HOURLY TEMPERATURES THROUGH THE NEXT FEW HOURS BASED UPON CURRENT OBSERVATIONS AND EXPECTED TRENDS. AS OF 400 AM EDT MONDAY... 500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN BEFORE 12Z/8AM. WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE. WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME. MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM TEMPERATURES TODAY AND LOWS TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 AM EDT MONDAY... A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA- LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE. MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY 501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS. TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS SOUTH. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 350 PM EDT SUNDAY... BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF THE CWA...ESPECIALLY THE NW NC MOUNTAINS. THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE CONVECTION WITH IT. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 1730 AM EDT MONDAY... ISOLATED SHOWERS SHOWN ON RADAR WILL MOVE EAST AND WEAKEN BEFORE 14Z. NO IMPACT IS EXPECTED FOR LOCAL AIRPORTS. THERE WILL BE MORE SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS UPPER ENERGY CROSSES THE AREA. EXPECT HIGHER PROBABILITY OF PRECIPITATION IN THE WEST. LOWER CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE CHANCE OF PRECIPITATION FROM THE FORECAST AFTER 03Z/11PM. EXTENDED AVIATION DISCUSSION... TUESDAY WILL SEE MORE WIDESPREAD THUNDERSTORMS SINCE A FRONT WILL SINK SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT LAKES AND NORTHEAST UNITED STATES. THIS FRONT SINKS SOUTH OF THE AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...RAB AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1003 AM EDT MON JUL 20 2015 .SYNOPSIS... A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS HUMID AND COOLER AIR BEHIND THE BOUNDARY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 955 AM EDT MONDAY... SHOWERS ACROSS THE AREA ARE OCCURRING IN TWO DISTINCT AREAS. THERE ARE WEAK AND ISOLATED SHOWERS HEADING EASTWARD THROUGH PARTS OF BATH AND ALLEGHANY COUNTIES OF VIRGINIA. THERE ARE MORE SUBSTANTIAL SHOWERS...AND A FEW THUNDERSTORMS...HEADING SOUTHEAST THROUGH THE NORTHERN MOUNTAINS OF NORTH CAROLINA FROM NORTHEAST TENNESSEE. COVERAGE WILL CONTINUE TO BE MINIMAL THROUGH THE REMAINDER OF THE MORNING HOURS AND ALSO THE EARLY AFTERNOON. LOOK FOR COVERAGE IN INCREASE ONCE WE REACH THE MID AFTERNOON...AND CONTINUE INTO THE EVENING HOURS. NO NOTABLE CHANGES HAVE BEEN MADE TO THE FORECAST HIGH TEMPERATURES. HOWEVER...SOME MINOR ADJUSTMENTS WERE MADE TO THE HOURLY TEMPERATURES THROUGH THE NEXT FEW HOURS BASED UPON CURRENT OBSERVATIONS AND EXPECTED TRENDS. AS OF 400 AM EDT MONDAY... 500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN BEFORE 12Z/8AM. WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE. WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME. MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM TEMPERATURES TODAY AND LOWS TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 AM EDT MONDAY... A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA- LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE. MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY 501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS. TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS SOUTH. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 350 PM EDT SUNDAY... BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF THE CWA...ESPECIALLY THE NW NC MOUNTAINS. THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE CONVECTION WITH IT. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... AS OF 1730 AM EDT MONDAY... ISOLATED SHOWERS SHOWN ON RADAR WILL MOVE EAST AND WEAKEN BEFORE 14Z. NO IMPACT IS EXPECTED FOR LOCAL AIRPORTS. THERE WILL BE MORE SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS UPPER ENERGY CROSSES THE AREA. EXPECT HIGHER PROBABILITY OF PRECIPITATION IN THE WEST. LOWER CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE CHANCE OF PRECIPITATION FROM THE FORECAST AFTER 03Z/11PM. EXTENDED AVIATION DISCUSSION... TUESDAY WILL SEE MORE WIDESPREAD THUNDERSTORMS SINCE A FRONT WILL SINK SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT LAKES AND NORTHEAST UNITED STATES. THIS FRONT SINKS SOUTH OF THE AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS/DS SHORT TERM...RCS LONG TERM...RAB AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
731 AM EDT MON JUL 20 2015 .SYNOPSIS... A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS HUMID AND COOLER AIR BEHIND THE BOUNDARY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT MONDAY... 500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN BEFORE 12Z/8AM. WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE. WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME. MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM TEMPERATURES TODAY AND LOWS TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 AM EDT MONDAY... A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA- LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE. MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY 501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS. TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS SOUTH. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 350 PM EDT SUNDAY... BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF THE CWA...ESPECIALLY THE NW NC MOUNTAINS. THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE CONVECTION WITH IT. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 1730 AM EDT MONDAY... ISOLATED SHOWERS SHOWN ON RADAR WILL MOVE EAST AND WEAKEN BEFORE 14Z. NO IMPACT IS EXPECTED FOR LOCAL AIRPORTS. THERE WILL BE MORE SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS UPPER ENERGY CROSSES THE AREA. EXPECT HIGHER PROBABILITY OF PRECIPITATION IN THE WEST. LOWER CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE CHANCE OF PRECIPITATION FROM THE FORECAST AFTER 03Z/11PM. EXTENDED AVIATION DISCUSSION... TUESDAY WILL SEE MORE WIDESPREAD THUNDERSTORMS SINCE A FRONT WILL SINK SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT LAKES AND NORTHEAST UNITED STATES. THIS FRONT SINKS SOUTH OF THE AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...RCS LONG TERM...RAB AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
418 AM EDT MON JUL 20 2015 .SYNOPSIS... A COLD FRONT EXTENDING FROM LAKE ONTARIO TO IOWA THIS MORNING WILL MOVE SOUTH INTO THE REGION TODAY. A SECOND STRONGER FRONT WILL PASS THROUGH THE REGION LATE TUESDAY. EXPECT PERIODS OF SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONTS...THEN DRY WEATHER WITH LESS HUMID AND COOLER AIR BEHIND THE BOUNDARY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 400 AM EDT MONDAY... 500 MB SHORT WAVE MOVING INTO WEST VIRGINIA WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS INTO THE WESTERN COUNTY WARNING AREA THIS MORNING. HRRR AND LOCAL WRF SHOWED SOME INDICATIONS THAT PRECIPITATION MAY SURVIVE ACROSS THE NORTHERN COUNTY WARNING AREA BUT OVERALL TREND WILL BE FOR SHOWERS AND THUNDERSTORMS TO WEAKEN BEFORE 12Z/8AM. WEST TO NORTHWEST SURFACE AND LOW LEVEL WIND EXPECTED TODAY WHICH FAVORS DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS AGAIN IN THE MOUNTAINS THIS AFTERNOON. WITH LEE TROUGHING IN PLACE...FAR EASTERN PIEDMONT MAY ALSO HAVE BETTER COVERAGE. WEST TO NORTHWEST WINDS WILL CREATE DOWNSLOPING AND MIXING BY THIS AFTERNOON...ENOUGH TO LOWER DEW POINTS INTO THE 60S IN THE FOOTHILLS AND KEEP THE HEAT INDEX EAST OF THE BLUE RIDGE FROM REACHING ADVISORY LEVELS. NO HEAT ADVISORY PLANNED AT THIS TIME. MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON. THESE STORMS WILL MOVE INTO THE WESTERN COUNTY WARNING AREA LATE TONIGHT. USED A BLEND OF BIAS CORRECTED MET/MAV GUIDANCE FOR MAXIMUM TEMPERATURES TODAY AND LOWS TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 330 AM EDT MONDAY... A COLD FRONT WILL MOVE OVER THE OHIO RIVER VALLEY TUESDAY MORNING AND IS EXPECTED TO JUMP TO THE LEE TROUGH PERCHED ACROSS THE PIEDMONT IN THE AFTERNOON. A PREFRONTAL SHORT WAVE WILL TRACK ACROSS KENTUCKY TUESDAY MORNING...BRINGING SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER...TO THE FAR WESTERN FORECAST AREA (BLUEFIELD VA- LEWISBURG WV). LOW AND MID LEVEL FLOW TURNS WESTERLY QUICKLY...REDUCING SHOWER ACTIVITY MOVING EAST TO THE BLUE RIDGE. MORNING SHOWERS MAY NOT COMPLETELY FADE AS THEY APPROACH THE BLUE RIDGE AS THIS WAVE TRACKS EAST OVER THE AREA. AS THE FRONT JUMPS TO THE LEE TROUGH IN THE AFTERNOON...A NEW LINE OF CONVECTION WILL FORM. ALL MODELS ARE HAVING A TOUGH TIME PINPOINTING WHERE THIS LINE WILL INITIATE. BASED ON WHERE MODELS HAVE THE LEE TROUGH POSITIONED...THIS LINE WILL BE EAST OF HWY 29...POSSIBLY EAST OF HWY 501. THE DEW POINT FRONT LAGS BEHIND AND THE MOUNTAINS MAY NOT SEE SHOWERS CLEARING THE AREA UNTIL LATE IN THE EVENING...WITH CLEARING IN THE PIEDMONT DURING THE EARLY MORNING HOURS WEDNESDAY. BY SUNRISE WEDNESDAY MORNING...THE DEW POINT FRONT SHOULD BE SOUTH INTO NORTH CAROLINA. A WEAK BUT COOL AREA OF HIGH PRESSURE WILL MOVE OVER THE REGION WEDNESDAY...KEEPING THE REGION DRY FOR A COUPLE OF DAYS. TUESDAY SHOULD BE THE LAST OF THE HOT DAY FOR THIS WEEK. DEPENDING ON THE TIMING OF SHOWERS...HIGH TEMPERATURES ACROSS THE MOUNTAINS WILL RANGE IN THE 80S...WITH LOWER TO MID 90S EAST. WEDNESDAY TEMPERATURES WILL FALL BACK CLOSER TO NORMAL AS THE FRONT SINKS SOUTH. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 350 PM EDT SUNDAY... BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH THURSDAY AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF THE CWA...ESPECIALLY THE NW NC MOUNTAINS. THERE IS BETTER PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE PASSES BY TO THE SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR THE FRONTAL BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE CONVECTION WITH IT. A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES TO REACH THE REGION. 850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS BY THE WEEKEND. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... AS OF 130 AM EDT MONDAY... WEAK SHORT WAVE COMING OUT OF OHIO WILL GENERATE SCATTERED SHOWERS AND THUNDERSTORMS OVER SOUTHERN WEST VIRGINIA THIS MORNING. EXPECT STORMS TO WEAKEN AS THEY MOVE EAST BUT HAVE KEPT VCSH IN THE KBLF AND KLWB TAF BEFORE 12Z. FORMATION OF MVFR FOG EARLY THIS MORNING WILL DEPEND ON AMOUNT OF CLOUD COVER. NO FOG FOG NOW EXPECTED AT KROA BUT CONFIDENCE IS HIGH ENOUGH TO INCLUDE IN KBCB/KLYH AND KDAN THROUGH 13Z/9AM. WILL SEE MORE SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS UPPER ENERGY CROSSES THE AREA. EXPECT HIGHER POPS IN THE WEST. LOWER CONFIDENCE THAT STORMS WILL IMPACT KLYH AND KDAN. THREAT OF SHOWERS AND THUNDERSTORMS WILL DIMINISH AFTER SUNSET. REMOVED THE CHANCE OF PRECIPITATION FROM THE FORECAST BY 03Z/11PM. EXTENDED AVIATION DISCUSSION... TUESDAY WILL SEE MORE WIDESPREAD THUNDERSTORMS SINCE A FRONT WILL SINK SWD IN RESPONSE TO STRONGER UPPER TROUGH OVER THE GREAT LAKES AND NORTHEAST UNITED STATES. THIS FRONT SINKS SOUTH OF THE AREA FOR WEDNESDAY AND THURSDAY AND BUCKLES NWD AGAIN FRIDAY. SO FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE CONVECTION TUESDAY...THEN FOG/STRATUS POSSIBLE WED/THU MORNING IN THE BCB/LWB AREA PENDING HOW DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...RCS LONG TERM...RAB AVIATION...AMS/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
248 PM CDT MON JUL 20 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 248 PM CDT MON JUL 20 2015 CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED A DEEP TROUGH PLOWING INTO BRITISH COLUMBIA... RIDGING OVER THE NORTHERN U.S. ROCKIES INTO ALBERTA / SASKATCHEWAN...AND TROUGHING FROM NORTHERN ONTARIO INTO NORTHERN MN. A SHORTWAVE WAS ALSO EVIDENT OVER EASTERN IOWA...WHICH COMBINED WITH A SURGE OF 850MB MOISTURE TRANSPORT...MID LEVEL FRONTOGENESIS AND PRECIPITABLE WATER AROUND 1.5 INCHES HELPED BRING SHOWERS AND SOME THUNDERSTORMS TO THE SOUTHEAST HALF OF THE FORECAST AREA THIS MORNING. A SURFACE COLD FRONT WAS ALSO MARCHING THROUGH THE FORECAST AREA...NOW FROM GREEN BAY TO OELWEIN. INSTABILITY HAS BEEN BEEN LIMITED DUE TO MORNING CLOUDS/SHOWERS... BUT RAP MESOANALYSIS SUGGESTS UP TO 1000 J/KG OF MLCAPE EXISTS ALONG THE FRONT. THIS INSTABILITY HAS RESULTED IN SOME ISOLATED SHOWERS ALONG THE FRONT...WITH WEAK LOW LEVEL CONVERGENCE PREVENTING MORE DEVELOPMENT. IN THE WAKE OF THE FRONT... PRECIPITABLE WATER DROPS DOWN TO 0.75 INCHES...RESULTING IN DRYING OF THE AIR INCLUDING AT THE SURFACE. HOWEVER...A FEW SHOWERS WERE NOTED IN THE COLD POOL REGION UNDERNEATH THE TROUGH IN FAR NORTHERN MN/ONTARIO. BREEZY CONDITIONS NOTED TOO BEHIND THE FRONT WITH TIGHTER PRESSURE GRADIENT AND DAYTIME MIXING. THESE NORTHWEST WINDS WERE DRIVING IN COLDER AIR...NOTED BY 850MB TEMPS OF 16-18C AHEAD COMPARED TO 8-10C OVER NORTHERN MN. SURFACE RIDGE RESIDED WELL TO THE WEST OVER THE WESTERN DAKOTAS. ANY SHOWERS/STORMS THE DEVELOP ALONG THE COLD FRONT OVER THE SOUTHEAST THIRD OF THE FORECAST AREA SHOULD EXIT BY 23/00Z AS THE FRONT CONTINUES TO PUSH SOUTHEAST. AFTER THAT...COOLER...DRIER AIR REMAINS ON TRACK TO DROP INTO THE REGION FOR TONIGHT AND MONDAY. THE EXTENSION OF THE UPPER TROUGH IN NORTHERN MN LOOKS TO SWING ACROSS ALL OF WI TONIGHT AND INTO THE EASTERN GREAT LAKES ON TUESDAY. THIS UPPER TROUGH WILL HELP DRIVE 850MB TEMPS DOWN TO 10-11C BY 12Z TUE. ANY OF THE SHOWERS ACCOMPANYING THE COLD POOL LOOK TO STAY WELL NORTH AND DIMINISH WITH LOSS OF DAYTIME HEATING THIS EVENING. SKIES WILL CLEAR OUT QUICKLY THIS EVENING AS DRY AIR INFILTRATES AND LOSS OF DAYTIME HEATING DISSIPATES CUMULUS. IF NOT FOR A PERSISTENT NORTHWEST BREEZE WE COULD SEE A DECENT VALLEY FOG EVENT. NEVERTHELESS...THE MORE SHELTERED SMALLER VALLEYS LIKE THE WISCONSIN WILL FOG. THE TYPICAL COLD SPOTS SHOULD ALSO RADIATE NICELY AND DIP DOWN INTO THE UPPER 40S. THE REST OF THE REGION SHOULD SEE LOWS IN THE 50S. PLENTY OF SUN ON TRACK FOR TUESDAY WITH DRY AIR IN PLACE AND HIGH PRESSURE BUILDING IN. WITH 850MB TEMPS CLIMBING TO 12-14C BY 00Z WEDNESDAY THANKS TO DEEP MIXING...HIGHS IN THE 70S SHOULD BE COMMON WITH LOW 80S FOUND IN RIVER VALLEYS AND SANDY SOIL AREAS. THE DEEP MIXING ALSO SHOULD PROMOTE IN QUITE A BIT LOWER DEWPOINTS COMPARED TO TODAY. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 248 PM CDT MON JUL 20 2015 UPPER RIDGING SEEN OVER THE NORTHERN ROCKIES AND SASKATCHEWAN / ALBERTA IS PROGGED TO GRADUALLY MOVE EAST INTO THE REGION OVER THE NEXT FEW DAYS...MOVING OVERHEAD AROUND 12Z FRIDAY. SUBSIDENCE WITH THIS UPPER RIDGING BUILDING IN...COMBINED WITH THE FRONT TODAY PUSHING ALL THE MOISTURE SOUTH OF I-70 RESULT IN DRY CONDITIONS FOR THE MOST PART THROUGH THURSDAY NIGHT. HOWEVER...THERE IS A BAND OF MID LEVEL FRONTOGENESIS THAT LOOKS TO SET UP LATE WEDNESDAY INTO THURSDAY...SITUATED FROM CENTRAL MN INTO NORTH CENTRAL WI. THE 20.12Z NAM/ECMWF/CANADIAN HAVE BACKED OFF ON THE INTENSITY AND THUS QPF PRODUCTION TO THE POINT OF NEARLY DRY. ON THE OTHER HAND THE 20.12Z GFS STILL PRODUCES SOME QPF. BELIEVE THE GFS MIGHT BE OVERLY MOIST...A KNOWN BIAS...AND THEREFORE HAVE TRENDED DRY FOR TAYLOR/CLARK COUNTIES DURING MID- WEEK. TEMPERATURES WEDNESDAY AND THURSDAY WILL BE ON A WARMING TREND AS 850MB TEMPS EVENTUALLY CLIMB TO 14-16C BY 00Z FRI. MAY HAVE TO CONTEND WITH VALLEY FOG TUESDAY NIGHT WITH LIGHT WINDS...BUT THERE ARE HINTS OF SOME CLOUDS PASSING THROUGH. THEREFORE...HAVE KEPT MUCH FOG OUT. FOR FRIDAY THROUGH MONDAY...THE MAIN FEATURE OF INTEREST IS A PORTION OF THE DEEP TROUGH IN BRITISH COLUMBIA THAT DROPS THROUGH THE REGION LATE FRIDAY THROUGH SATURDAY EVENING. 20.12Z GFS/ECMWF/CANADIAN ALL WANT TO DEVELOP CONVECTION IN WARM ADVECTION AHEAD OF THE SHORTWAVE TROUGH...THEN ADDITIONAL CONVECTION AS THE COLD FRONT ASSOCIATED WITH THE TROUGH COMES THROUGH. SOME TIMING ISSUES THUS PRECIPITATION CHANCES ARE SPREAD OUT...THOUGH IF TRENDS CONTINUE SHOULD BE ABLE TO PULL OUT CHANCES FOR SATURDAY NIGHT AND EVEN SATURDAY AFTERNOON. IF THE GFS PANS OUT WE MIGHT HAVE TO DEAL WITH SOME SEVERE STORMS...PARTICULARLY FRIDAY NIGHT...BUT THE ECMWF WOULD KEEP ITS SEVERE THREAT FARTHER TO THE SOUTHWEST. SOMETHING TO WATCH. DRIER WEATHER THEN FOLLOWS FOR SUNDAY AS UPPER AND SURFACE RIDGING BEGINS BUILDING BACK IN. PERHAPS ANOTHER INTERESTING PERIOD COULD SETUP SUNDAY NIGHT AND MONDAY...PARTICULARLY IN THE ECMWF...AS A SHORTWAVE COMES DOWN THE RIDGE BUILDING IN. FOR NOW JUST HAVE SOME LOW CHANCES ON MONDAY PER CONSENSUS BUT THESE MAY NEED ADJUSTMENT. OVERALL TEMPERATURES LOOK TO STAY AT OR ABOVE SEASONABLE NORMALS...AND SOME OF THE HIGHS IN THE CURRENT FORECAST ALTHOUGH NEAR CONSENSUS COULD END UP BEING A LITTLE HIGHER. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1226 PM CDT MON JUL 20 2015 A COLD FRONT EXTENDED FROM NEAR KMCW TO KRST TO KRPD AT 20.1730Z AND WILL CONTINUE TO SLIDE EAST-SOUTHEAST THROUGH THE AFTERNOON. MAJORITY OF SHOWERS WITH EMBEDDED ISOLATED THUNDERSTORMS FROM NORTHEAST IA INTO SOUTHERN WI/NORTHERN IL WILL MOVE OUT OF THE REGION...BUT COULD SEE SOME SCATTERED CONVECTION REDEVELOP ALONG THE COLD FRONT THIS AFTERNOON. THIS ACTIVITY SHOULD BE EAST OF THE TAF SITES...KEEPING THEM DRY THROUGH THE PERIOD. DRY AIR MASS BEHIND THE FRONT WILL RESULT IN MOSTLY SUNNY/CLEAR/VFR CONDITIONS THROUGH 21.18Z. WINDS WILL SHIFT TO THE NORTHWEST WITH THE FRONTAL PASSAGE...GUSTING OCCASIONALLY UP TO 20 KTS AT KRST THIS AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...AJ LONG TERM...AJ AVIATION...ROGERS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1011 AM CDT MON JUL 20 2015 .UPDATE... 500 MB SHORTWAVE TROUGH OVER NORTHWEST IOWA INTO NORTHEAST NEBRASKA IS EXPECTED TO SLIDE SOUTHEASTWARD THIS AFTERNOON AND EARLY THIS EVENING...CLIPPING SOUTHERN WISCONSIN. A COLD FRONT WILL ALSO MOVE SOUTHEAST THROUGH THE AREA LATER THIS AFTERNOON AND EARLY THIS EVENING. AREA OF SHOWERS WITH A FEW THUNDERSTORMS BEING HELPED ALONG BY THESE FEATURES ACROSS SOUTHWEST WISCONSIN INTO CENTRAL IOWA. MESOSCALE MODELS WERE MIXED WITH INITIALIZATION OF CURRENT FEATURES...AND DIFFER WITH HOW MUCH OF THIS ACTIVITY MOVES THROUGH THE AREA THIS AFTERNOON. RAP SOUNDINGS SHOWING DECENT HANDLE ON SURFACE DEW POINTS...WITH TALL AND SKINNY MEAN LAYER CAPES UP TO 800 J/KG OR SO. DEEP LAYER SHEAR IS MODEST...WITH POOR MID LEVEL LAPSE RATES. GIVEN THE ABOVE...EXPECTING SCATTERED SHOWERS AND SOME STORMS ACROSS THE AREA THIS AFTERNOON...ENDING BY EARLY EVENING...AS THE FRONT AND SHORTWAVE TROUGH MOVE THROUGH. SOME GUSTY WINDS MAY OCCUR WITH THE STORMS. BROKEN CLOUD COVER IS EXPECTED THROUGH MOST OF THE REST OF THE DAY...WHICH MAY HOLD DOWN HIGHS A BIT. MAY HAVE TO ADJUST THESE DOWNWARD FROM THE CURRENT MID 80S. && .AVIATION/18Z TAFS/... BROKEN VFR CLOUDS WILL CONTINUE TO SPREAD ACROSS THE AREA TODAY INTO EARLY THIS EVENING. COLD FRONT IS EXPECTED TO SLIDE SOUTHEAST TOWARD THE AREA THIS AFTERNOON...THEN ACROSS THE AREA EARLY THIS EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ALONG AND AHEAD OF THE FRONT...MAINLY IN THE AFTERNOON. GIVEN SOME UNCERTAINTY WITH TIMING AND AREAL COVERAGE...USED VICINITY SHOWER WORDING IN TAFS FOR NOW. MVFR VISIBILITIES AND CEILINGS ARE POSSIBLE IN ANY STORMS. GUSTY SOUTHWEST WINDS WILL DEVELOP AND LINGER THROUGH THE AFTERNOON. GUSTS TO AROUND 20 KNOTS ARE EXPECTED. WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT TONIGHT AND LINGER ON TUESDAY. CLOUDS WILL GRADUALLY MOVE OUT OF THE AREA LATER THIS EVENING...WITH MOSTLY CLEAR SKIES LATER TONIGHT INTO TUESDAY. && .MARINE... SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE NEARSHORE WATERS OF LAKE MICHIGAN UNTIL 10 PM CDT THIS EVENING. GUSTY SOUTHWEST WINDS ARE EXPECTED TO DEVELOP OVER THE NEXT HOUR OR TWO...AND LINGER UNTIL EARLY THIS EVENING. FREQUENT GUSTS UP TO AROUND 25 KNOTS ARE ANTICIPATED...ESPECIALLY NEAR THE SHORELINE. HIGH WAVES WILL REMAIN OVER THE OPEN WATERS...WITH THE OFFSHORE FLOW. && .PREV DISCUSSION... /ISSUED 338 AM CDT MON JUL 20 2015/ SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. THE MAIN FOCUS FOR TODAY IS ON THE CHANCES FOR CONVECTION AHEAD OF A COLD FRONT WHICH WILL PUSH THROUGH THE REGION BY THIS EVENING. A CLUSTER OF SHOWERS OUT IN NORTHWEST IOWA AND SOUTHWEST MINNESOTA ASSOCIATED WITH A MID LEVEL SHORT WAVE TROUGH IS EXPECTED TO DIMINISH IN COVERAGE/INTENSITY OVER THE NEXT FEW HOURS...BUT COULD CLIP PORTIONS OF SOUTH CENTRAL WISCONSIN THIS MORNING...SO HAVE PUT SOME HIGH CHANCES IN THERE FOR THE SHOWERS. INSTABILITY WILL BE ON THE INCREASE TODAY AHEAD OF THE COLD FRONT WHICH IS CURRENTLY IN CENTRAL MINNESOTA AND WILL EXTEND FROM NORTHEAST WISCONSIN TO WEST CENTRAL WISCONSIN AROUND NOON TODAY. HAVE LIKED THE RAP THIS MORNING AND ITS TRENDS WITH SURFACE DEW POINTS/INSTABILITY...WHICH IS ON THE LOWER SIDE AT 1000 J/KG MLCAPE WHEN COMPARED TO THE 20.00Z NAM/GFS WHICH ARE PUSHING CLOSER TO 2000-3000 J/KG THANKS TO FORECAST SURFACE DEW POINTS OVER 70F. SHOULD THE RAP THERMAL PROFILE PAN OUT...IT WOULD MEAN A SKINNY CAPE SCENARIO WITH DECREASING SHEAR DUE TO THE LEAD SHORTWAVE TROUGH DEPARTING TO THE SOUTHEAST. THEREFORE...OUTSIDE OF A FEW HIGHER GUSTS POSSIBLE DUE TO THE DRY SOUNDING...AM NOT ANTICIPATING MUCH IN THE WAY OF SEVERE WEATHER FOR TODAY. AFTER THE COLD FRONT MOVES THROUGH...SKIES WILL CLEAR OUT WITH WINDS GOING LIGHT TONIGHT. LONG TERM... TUESDAY THROUGH FRIDAY... FORECAST CONFIDENCE HIGH. DRIER AIR WILL SETTLE INTO SOUTHERN WI ON TUESDAY. A HIGH AMPLITUDE UPPER RIDGE OVER THE CENTER OF THE COUNTRY AND A SPRAWLING UPPER LOW OVER ONTARIO AND QUEBEC CANADA WILL SET UP A BLOCKING PATTERN AND WE WILL BE UNDER A DRY NORTHWEST FLOW PATTERN THROUGH MUCH OF THE WEEK. SURFACE HIGH PRESSURE WILL TAKE HOLD OVER THE GREAT LAKES REGION AND WE CAN EXPECT LIGHT WESTERLY WINDS. MAX TEMPERATURES WILL ONLY BE IN THE UPPER 70S TUESDAY AND GRADUALLY MODIFY INTO THE LOWER 80S BY FRIDAY... EXCEPT SLIGHTLY COOLER BY THE LAKESHORE. THE GFS ALLOWS A SHORTWAVE TO MAKE IT ACROSS A HIGH-AMPLITUDE RIDGE OVER THE UPPER MIDWEST AND BRING PRECIP TO WI ON THURSDAY. THE ECMWF SHOWS A WEAKER SHORTWAVE THAT RUNS INTO THE DRY AIR AND KEEPS THE AREA DRY. TRENDED TOWARD THE DRIER FORECAST FOR THU SINCE PRECIP WILL HAVE A HARD TIME OVERCOMING THE DRY AIR IN PLACE. SATURDAY... FORECAST CONFIDENCE MEDIUM. THERE IS BETTER AGREEMENT FOR A STRONGER SHORTWAVE TROUGH TO REACH THE GREAT LAKES ON FRI NIGHT OR SATURDAY AND BRING SHOWER AND THUNDERSTORM CHANCES TO WI. THE GFS IS STRONGER AND BRINGS A BOWLING BALL UPPER LOW THROUGH SOUTHERN CANADA WITH THE SURFACE TROUGH CROSSING WI FRIDAY NIGHT. THE ECMWF HAS A WEAKER UPPER TROUGH AND DELAYS THE SURFACE TROUGH UNTIL SATURDAY AFTERNOON. A FRIDAY NIGHT FRONTAL PASSAGE WOULD KEEP SEVERE THUNDERSTORM CHANCES DOWN. SUNDAY AND MONDAY... FORECAST CONFIDENCE MEDIUM. A RIDGE OVER THE SOUTHWEST STATES WILL KEEP US IN A FAIRLY DRY NORTHWEST FLOW PATTERN EARLY NEXT WEEK. WEAK SHORTWAVES RIDING OVER THE RIDGE WILL LEAD TO INTERMITTENT PRECIP CHANCES. EXPECT MAX TEMPERATURES TO REMAIN IN THE LOWER 80S DURING THIS TIME. AVIATION/12Z TAFS/... THE MAIN FOCUS AT THE TAF SITES IS ON THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS TODAY AHEAD OF A COLD FRONT. WINDS WILL BECOME GUSTY AS WELL OUT OF THE SOUTHWEST AHEAD OF THE FRONT WITH SOME GUSTS POSSIBLY REACHING THE 20-25KT RANGE. ANY SHOWERS OR THUNDERSTORMS COULD PRODUCE SOME WINDY CONDITIONS AS WELL...BUT THINK THAT FLIGHT CONDITIONS SHOULD MAINLY STAY VFR GIVEN HOW DRY CONDITIONS ARE. SKIES WILL CLEAR OUT AND WINDS WILL GO LIGHT THIS EVENING AS THE FRONT PUSHES OFF TO THE SOUTHEAST. MARINE... THE MAIN CONCERN FOR TODAY IS WITH THE GUSTY OFF SHORE WINDS WHICH LOOK LIKE THEY WILL PUSH INTO THE 20 TO 30KT RANGE...PARTICULARLY FURTHER TO THE NORTH. WAVES WILL BE THE HIGHEST OUT TOWARD THE OPEN WATER DUE TO THE WEST-SOUTHWEST WINDS. MAY HAVE TO PUSH OUT A SMALL CRAFT ADVISORY DUE TO THESE POTENTIALLY HIGHER GUSTS. OTHERWISE...SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY AS WELL WHEN A COLD FRONT DROPS THROUGH THE REGION. SOME GUSTY WINDS MAY ACCOMPANY THESE SHOWERS AND STORMS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643>645. && $$ UPDATE...WOOD TODAY/TONIGHT AND AVIATION/MARINE...HALBACH TUESDAY THROUGH SUNDAY...MRC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
338 AM CDT MON JUL 20 2015 .SHORT TERM... TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM. THE MAIN FOCUS FOR TODAY IS ON THE CHANCES FOR CONVECTION AHEAD OF A COLD FRONT WHICH WILL PUSH THROUGH THE REGION BY THIS EVENING. A CLUSTER OF SHOWERS OUT IN NORTHWEST IOWA AND SOUTHWEST MINNESOTA ASSOCIATED WITH A MID LEVEL SHORT WAVE TROUGH IS EXPECTED TO DIMINISH IN COVERAGE/INTENSITY OVER THE NEXT FEW HOURS...BUT COULD CLIP PORTIONS OF SOUTH CENTRAL WISCONSIN THIS MORNING...SO HAVE PUT SOME HIGH CHANCES IN THERE FOR THE SHOWERS. INSTABILITY WILL BE ON THE INCREASE TODAY AHEAD OF THE COLD FRONT WHICH IS CURRENTLY IN CENTRAL MINNESOTA AND WILL EXTEND FROM NORTHEAST WISCONSIN TO WEST CENTRAL WISCONSIN AROUND NOON TODAY. HAVE LIKED THE RAP THIS MORNING AND ITS TRENDS WITH SURFACE DEW POINTS/INSTABILITY...WHICH IS ON THE LOWER SIDE AT 1000 J/KG MLCAPE WHEN COMPARED TO THE 20.00Z NAM/GFS WHICH ARE PUSHING CLOSER TO 2000-3000 J/KG THANKS TO FORECAST SURFACE DEW POINTS OVER 70F. SHOULD THE RAP THERMAL PROFILE PAN OUT...IT WOULD MEAN A SKINNY CAPE SCENARIO WITH DECREASING SHEAR DUE TO THE LEAD SHORTWAVE TROUGH DEPARTING TO THE SOUTHEAST. THEREFORE...OUTSIDE OF A FEW HIGHER GUSTS POSSIBLE DUE TO THE DRY SOUNDING...AM NOT ANTICIPATING MUCH IN THE WAY OF SEVERE WEATHER FOR TODAY. AFTER THE COLD FRONT MOVES THROUGH...SKIES WILL CLEAR OUT WITH WINDS GOING LIGHT TONIGHT. .LONG TERM... TUESDAY THROUGH FRIDAY... FORECAST CONFIDENCE HIGH. DRIER AIR WILL SETTLE INTO SOUTHERN WI ON TUESDAY. A HIGH AMPLITUDE UPPER RIDGE OVER THE CENTER OF THE COUNTRY AND A SPRAWLING UPPER LOW OVER ONTARIO AND QUEBEC CANADA WILL SET UP A BLOCKING PATTERN AND WE WILL BE UNDER A DRY NORTHWEST FLOW PATTERN THROUGH MUCH OF THE WEEK. SURFACE HIGH PRESSURE WILL TAKE HOLD OVER THE GREAT LAKES REGION AND WE CAN EXPECT LIGHT WESTERLY WINDS. MAX TEMPERATURES WILL ONLY BE IN THE UPPER 70S TUESDAY AND GRADUALLY MODIFY INTO THE LOWER 80S BY FRIDAY... EXCEPT SLIGHTLY COOLER BY THE LAKESHORE. THE GFS ALLOWS A SHORTWAVE TO MAKE IT ACROSS A HIGH-AMPLITUDE RIDGE OVER THE UPPER MIDWEST AND BRING PRECIP TO WI ON THURSDAY. THE ECMWF SHOWS A WEAKER SHORTWAVE THAT RUNS INTO THE DRY AIR AND KEEPS THE AREA DRY. TRENDED TOWARD THE DRIER FORECAST FOR THU SINCE PRECIP WILL HAVE A HARD TIME OVERCOMING THE DRY AIR IN PLACE. SATURDAY... FORECAST CONFIDENCE MEDIUM. THERE IS BETTER AGREEMENT FOR A STRONGER SHORTWAVE TROUGH TO REACH THE GREAT LAKES ON FRI NIGHT OR SATURDAY AND BRING SHOWER AND THUNDERSTORM CHANCES TO WI. THE GFS IS STRONGER AND BRINGS A BOWLING BALL UPPER LOW THROUGH SOUTHERN CANADA WITH THE SURFACE TROUGH CROSSING WI FRIDAY NIGHT. THE ECMWF HAS A WEAKER UPPER TROUGH AND DELAYS THE SURFACE TROUGH UNTIL SATURDAY AFTERNOON. A FRIDAY NIGHT FRONTAL PASSAGE WOULD KEEP SEVERE THUNDERSTORM CHANCES DOWN. SUNDAY AND MONDAY... FORECAST CONFIDENCE MEDIUM. A RIDGE OVER THE SOUTHWEST STATES WILL KEEP US IN A FAIRLY DRY NORTHWEST FLOW PATTERN EARLY NEXT WEEK. WEAK SHORTWAVES RIDING OVER THE RIDGE WILL LEAD TO INTERMITTENT PRECIP CHANCES. EXPECT MAX TEMPERATURES TO REMAIN IN THE LOWER 80S DURING THIS TIME. && .AVIATION/12Z TAFS/... THE MAIN FOCUS AT THE TAF SITES IS ON THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS TODAY AHEAD OF A COLD FRONT. WINDS WILL BECOME GUSTY AS WELL OUT OF THE SOUTHWEST AHEAD OF THE FRONT WITH SOME GUSTS POSSIBLY REACHING THE 20-25KT RANGE. ANY SHOWERS OR THUNDERSTORMS COULD PRODUCE SOME WINDY CONDITIONS AS WELL...BUT THINK THAT FLIGHT CONDITIONS SHOULD MAINLY STAY VFR GIVEN HOW DRY CONDITIONS ARE. SKIES WILL CLEAR OUT AND WINDS WILL GO LIGHT THIS EVENING AS THE FRONT PUSHES OFF TO THE SOUTHEAST. && .MARINE... THE MAIN CONCERN FOR TODAY IS WITH THE GUSTY OFF SHORE WINDS WHICH LOOK LIKE THEY WILL PUSH INTO THE 20 TO 30KT RANGE...PARTICULARLY FURTHER TO THE NORTH. WAVES WILL BE THE HIGHEST OUT TOWARD THE OPEN WATER DUE TO THE WEST-SOUTHWEST WINDS. MAY HAVE TO PUSH OUT A SMALL CRAFT ADVISORY DUE TO THESE POTENTIALLY HIGHER GUSTS. OTHERWISE...SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY AS WELL WHEN A COLD FRONT DROPS THROUGH THE REGION. SOME GUSTY WINDS MAY ACCOMPANY THESE SHOWERS AND STORMS. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...HALBACH TUESDAY THROUGH SUNDAY...MRC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1133 PM MDT TUE JUL 21 2015 .UPDATE... ISSUED AT 613 PM MDT TUE JUL 21 2015 UPDATED GRIDS/ZONES PER LATEST RADAR AND SAT TRENDS ALONG WITH HIGH RES PROGS. HRRR DEVELOPS ANOTHER ROUND OF SHOWERS/STORMS OVER THE NRN I-25 CORRIDOR LATER THIS EVE...AS A SECOND SHORTWAVE NOW MOVING THROUGH NWRN CO MOVES THROUGH. CANNOT DISCOUNT IT...ALTHOUGH MOST OF THE HEAVIER CONVECTION IS NOW E OF THE CORRIDOR...SO WILL MAINTAIN LOW POPS THROUGH LATE TONIGHT FOR THE PLAINS. ROSE && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 238 PM MDT TUE JUL 21 2015 CURRENTLY...SOMEWHAT FLAT UPPER RIDGE OVER THE SOUTHERN U.S TODAY...WHILE AN UPPER SHORTWAVE WAS CROSSING WY. THE DAY STARTED OFF MOSTLY CLOUDY FOR MOST AREAS AND MT CONVECTION WAS SLOW TO INITIATE. A LITTLE BIT OF CLEARING...AND FORTUITOUS TIMING OF THE UPPER SHORTWAVE...HAS NOW KICKED SHOWERS AND STORMS OFF OVER THE HIGHER TERRAIN AND ADJACENT PLAINS. HI RES MODELS HAVE HAD A VERY DIFFICULT TIME TRYING TO GET A HANDLE ON ACTUAL ONGOING WX...SO THE SHORT TERM FORECAST HAS BEEN A LITTLE CHALLENGING. TEMPS HAVE WARMED INTO THE 70S AND 80S FOR MOST LOCATIONS. TONIGHT...BANDS OF CONVECTION...LIKELY TIED TO THE UPPER SHORTWAVE TO THE NORTH...WILL CONTINUE ACROSS THE FORECAST AREA THIS EVE UNTIL THE 04Z-06Z TIME FRAME. STORMS HAVE BEEN MOVING...SO NO WORD OF ANY FLOODING ISSUES SO FAR AND STORMS HAVE BEEN AVOIDING AREA BURN SCARS...SO FAR. SPC HAS PAINTED MUCH OF THE E PLAINS IN THE MARGINAL AREA....SO THERE IS STILL THE POSSIBILITY OF A STRONG TO SEVERE STORM ACROSS THE PLAINS THIS EVE PRODUCING DAMAGING WINDS AND HAIL AROUND 1 INCH. THE UPPER WAVE WILL CONTINUE EAST TONIGHT...AND CONVECTION IS FORECAST TO DIMINISH LATE FROM WEST TO EAST AND TAPER OFF OVERNIGHT. TOMORROW...MODELS INDICATE THAT THE UPPER RIDGE WILL START TO STRENGTHEN AND BUILD INTO COLORADO...SHUNTING AVAILABLE MOISTURE EITHER FAR NORTH...OR WELL SOUTH. THERE WILL STILL BE THE ISOLATED SHOT AT MT CONVECTION STARTING MIDDAY...BUT FOR THE MOST PART THIS LOOKS LIKE THE START TO A WARM AND ESSENTIALLY DRY PERIOD INTO THE WEEKEND. LOOK FOR MAX TEMPS IN THE 80S TO LOWER 90S FOR THE E PLAINS...AND 80S FOR THE HIGH VALLEYS. MOORE .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 238 PM MDT TUE JUL 21 2015 MODEST SOUTHWEST FLOW ALOFT WILL CONTINUE OVER THE REGION DURING THIS FORECAST TIME PERIOD. GUIDANCE INDICATES THAT AREAS ALONG AND WEST OF THE CONTDVD WILL LIKELY SEE LESS STORMS OVERALL AS DRIER AIR IS FORECAST TO IMPINGE OVER THIS REGION DURING MOST OF THE PERIOD...SO THE BEST CHANCE OF STORMS WILL LIKELY BE ALONG THE MOUNTAINS/PLAINS INTERFACE...IE...THE PIKES PEAK REGION...WETS AND SANGRE DE CRISTO MOUNTAINS. WITH NO SIGNIFICANT SURGE OF MOISTURE NOTED IN THE GUIDANCE AND ONLY MODEST WEAK BOUNDARIES MOVING ACROSS THE PLAINS...THE POPS OVER THE MTNS/PLAINS INTERFACE WILL BE IN THE ISOLD TO LOW SCATTERED CATEGORY...WITH MAINLY ISOLD POPS OVER THE PLAINS. THE OVERALL BEST CHANCE OF PRECIP WILL BE OVER THE WEEKEND. MAX TEMPS THROUGH THE PERIOD WILL GENERALLY BE IN THE L/M90S ACROSS MOST OF THE PLAINS...WITH 70S AND 80S OVER THE VALLEYS. /HODANISH && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1127 PM MDT TUE JUL 21 2015 MAIN CONCERN WILL BE FOR SOME MVFR TO POSSIBLY IFR CIGS DEVELOPING LATE TONIGHT OR EARLY WED MORNING OVER THE LOWER ARKANSAS VALLEY AND PORTIONS OF THE SE CO PLAINS. THIS IS NOT A CERTAINTY AT THIS TIME...BUT THERE IS A HIGH ENOUGH PROBABILITY THAT LOW CIGS WILL DEVELOP AT KCOS FOR A FEW HOURS EARLY WED THAT IT HAS BEEN INTRODUCED IN THE TAF. VERY MOIST CONDITIONS ARE PRESENT IN THE LOWER LEVELS AND WINDS WILL BE LIGHT. PROBABILITY IS SLIGHTLY LOWER AT KPUB SO WILL LEAVE THE LOW CLOUD GROUP SCT FOR NOW...BUT THIS MAY REQUIRE AMENDMENT IF LOW CIGS DEVELOP OVERNIGHT. KALS SHOULD REMAIN VFR. DRY AIR WILL MOVE INTO SE CO ON WED...SO TS PROBABILITIES WILL BE TOO LOW TO MENTION EVEN AS VCTS IN THE TAFS. THERE COULD BE SOME BUILDUPS OVER THE MTS...BUT THEY SHOULD STAY CONFINED TO THE HIGHER ELEVATIONS. ROSE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ROSE SHORT TERM...MOORE LONG TERM...HODANISH AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
328 AM CDT WED JUL 22 2015 .SHORT TERM...(TODAY) ISSUED AT 328 AM CDT WED JUL 22 2015 HIGH PRESSURE CENTERED OVER THE MIDWEST EARLY THIS MORNING WILL DOMINATE THE WEATHER OVER MOST OF THE FORECAST AREA THRU THE DAY. HAVE HAD SOME PATCHY FOG DEVELOP OVER PARTS OF THE AREA EARLY THIS MORNING WITH THE HRRR SUGGESTING PARTS OF THE IL RIVER VALLEY AND FROM CMI TO JUST SOUTH OF SPI WILL SEE SOME RESTRICTED VISIBILITIES AT TIMES EARLY THIS MORNING. FORECAST SOUNDINGS AND TIME HEIGHT CROSS SECTIONS INDICATE AN INCREASE IN HIGH LEVEL CLOUD COVER LATER THIS MORNING INTO THE AFTERNOON HOURS AS SHORTWAVE ENERGY TRACKS WELL SOUTH OF THE REGION TODAY. RAP SOUNDINGS INDICATE WE SHOULD MIX DOWN FROM AROUND 800 MB OR APPROX 6000 FEET...WHICH WOULD BRING US AFTERNOON HIGHS IN THE 80 TO 84 DEGREE RANGE. CLOUD COVER SHOULD THICKEN UP EVEN MORE OVER FAR SOUTHEAST IL LATE THIS AFTERNOON AS ADDITIONAL SHORTWAVE ENERGY AND 850-700 MB MOISTURE CONVERGENCE APPROACHES THE I-70 CORRIDOR TOWARDS 00Z. && .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 328 AM CDT WED JUL 22 2015 MODELS HAVE SHIFTED CONSIDERABLY WITH THE HANDLING OF THE EXTENDED SUN-WED. IN THE MEANTIME, HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THURSDAY, WITH THE WARMING TREND CONTINUING THROUGH THE END OF THE WEEK AND INTO THE WEEKEND. BROAD UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY. FOR NOW, THE FORECAST IS DRY, BUT THE NAM CONTINUING TO TREND THE TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS WILL REMAIN IN THE FORECAST FOR THU. AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE AXIS DRIFTING OVER THE MIDWEST, TEMPS WARM INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION. HOWEVER, MODELS HIGH TEMPS WILL BE COOLED CONSIDERABLY SHOULD THE PRECIP THAT IS CURRENTLY SHOWING UP IN THE SAT NIGHT-TUES TIME FRAME MATERIALIZES. PREV DRY RUNS UNDER THE EXPANSIVE RIDGE WITH WEAK FLOW ARE LOSING THE DRY FORECAST TO A SERIES OF SMALL WAVES AND WHAT LOOKS LIKE A STALLED BOUNDARY AT THE SFC ALONG THE OHIO RIVER VALLEY SIMILAR TO THE SAME PATTERN REPEATED THROUGH THIS SUMMER. WITH A LACK OF CONTINUITY OR CONSENSUS, SLIGHTS AND LOW CHANCE POPS THROUGH THE END WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1149 PM CDT TUE JUL 21 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE ENTIRE 06Z TAF PERIOD...AS HIGH PRESSURE DOMINATES THE WEATHER. NEARLY CALM WINDS TONIGHT WILL BECOME SOUTHEASTERLY AT 5-8KT ON WEDNESDAY. FORECAST SOUNDINGS SUGGEST SCT DIURNAL CLOUDS DEVELOPING FROM LATE MORNING THROUGH THE AFTERNOON...WITH PERHAPS SOME SCT-BKN HIGH CLOUDS SPREADING ACROSS THE AREA FROM LATE AFTERNOON INTO WEDNESDAY NIGHT AS LOW PRESSURE TRACKS ACROSS THE OZARKS INTO THE OHIO RIVER VALLEY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS HASTINGS NE
339 AM CDT WED JUL 22 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT WED JUL 22 2015 FOCUS WILL BE ON THE CHANCE FOR RAIN TODAY AND TONIGHT. MOST NOTABLE THING WILL BE THE FACT THESE CHANCES HAVE DIMINISHED ACROSS THE FORECAST AREA. TEMPERATURES WILL BE BELOW NORMAL FOR HIGHS TODAY...BUT LOWS WILL BE ABOVE NORMAL LATER TONIGHT. AT THE SURFACE...AN AREA OF HIGH PRESSURE IS CENTER EAST OF THE FORECAST AREA...WHICH SHOULD KEEP US IN A SOUTHERLY WIND PATTERN THROUGH THE SHORT TERM WITH SPEEDS GENERALLY AROUND/UNDER 10 MPH. WE LACK A TRIGGERING MECHANISM TODAY...AND CAPE VALUES ARE NIL TO VERY LOW FOR MOST OF THE DAY. MUCAPE VALUES START TO PICK UP THIS AFTERNOON...ESPECIALLY ACROSS OUR SOUTHWEST AND SOUTH...WITH VALUES MOSTLY AROUND THE 500-1500 J/KG RANGE. THE NAM SUGGEST VALUES COULD BE AS HIGH AS 2000 J/KG BUT THIS IS THE MORE AGGRESSIVE SOLUTION. 0- 6 KM BULK SHEAR VALUES RANGE BETWEEN 20-35 KNOTS. 0-1 KM HELICITY VALUES VARY GREATLY BETWEEN THE NAM...GFS...AND EUROPEAN. OVERALL...THESE VALUES ARE VERY LOW UNTIL TONIGHT WHEN VALUES RANGE BETWEEN 80-150 M^2/S^2 OVERNIGHT. WITHOUT A TRUE TRIGGERING MECHANISM TODAY...WE ARE RELYING SOLELY ON ISENTROPIC LIFT WHICH IS NOT BACK ACROSS KANSAS...AND THIS IS REFLECTED IN THE FORECAST WITH HIGHER POPS ACROSS THE SOUTH. WE ARE REALLY GOING TO STRUGGLE TO GET RAINFALL TODAY. MANY OF THE SIMULATED REFLECTIVITY MODELS SUGGEST MOSTLY DRY CONDITIONS OVER THE SHORT TERM. THE HRRR IS REALLY THE MOST OPTIMISTIC FOR RAINFALL CHANCES TODAY. NMM...ARW...AND THE NAM4KM ALL HAVE MOSTLY DRY CONDITIONS. I HAVE DECREASED POPS FROM THE PREVIOUS FORECAST TO REFLECT THIS TREND. HIGHER CHANCES WILL BE TONIGHT...ESPECIALLY FOR AREAS GENERALLY SOUTH OF INTERSTATE 80. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 338 AM CDT WED JUL 22 2015 GUIDANCE SUGGESTS GENERALLY WEAK QUASI-ZONAL UPPER TROPOSPHERIC FLOW WILL EXIST OVER THE CENTRAL PLAINS TO START THE LONG-TERM FORECAST PERIOD AT 12Z THURSDAY. GUIDANCE SUGGESTS THIS WEAK UPPER TROPOSPHERIC FLOW WILL CONTINUE OVER OUR AREA THROUGH NEXT SUNDAY AS UPPER TROPOSPHERIC RIDING STRENGTHENS ACROSS THE AREA. SOME BREAKDOWN IN THE RIDGE IS THEN EXPECTED EARLY NEXT WEEK AS AN UPPER TROPOSPHERIC SHORT WAVE MOVES FROM THE NORTHWESTERN CONUS INTO THE NORTH CENTRAL CONUS. IT APPEARS OMEGA WILL REMAIN ON THE WEAK SIDE ACROSS OUR AREA DURING MUCH OF THE LONG-TERM FORECAST PERIOD...WHICH INCLUDES EARLY NEXT WEEK WITH THE AFOREMENTIONED UPPER TROPOSPHERIC SHORT WAVE REMAINING NORTH OF OUR AREA. THAT SAID...VARIOUS SETS OF GUIDANCE CONTINUE TO SUGGEST AN UPPER TROPOSPHERIC PERTURBATION OR TWO COULD CLEAR THE REGION LATE THIS WEEK INTO EARLY NEXT WEEK...AND THERE REMAIN SIGNALS THAT HIGH PLAINS CONVECTION COULD SUSTAIN ITSELF LONG ENOUGH TO IMPACT OUR AREA DURING THE EVENING AND OVERNIGHT HOURS BETWEEN THURSDAY AND TUESDAY. GIVEN ALL THIS...WENT AHEAD WITH GENERALLY 20- 40% POPS ACROSS VARIOUS PORTIONS OF THE CWA BETWEEN THURSDAY EVENING AND NEXT TUESDAY. AS MENTIONED YESTERDAY...LOW VALUES DEEP-LAYER SHEAR AND HIGH VALUES OF POTENTIAL ENERGY SHOULD PRESENT ITSELF ACROSS MUCH OF THE AREA DURING THE LONG-TERM FORECAST PERIOD. ALTHOUGH THERE REMAINS CONSIDERABLE UNCERTAINTY WITH RESPECT TO THE TIMING AND PLACEMENT OF CONVECTIVE INITIATION FROM DAY TO DAY...GIVEN THE FACT THAT GUIDANCE SUGGESTS POTENTIAL ENERGY VALUES OF ~2000J/KG WILL BE REALIZED ACROSS MUCH OF THE AREA BOTH THURSDAY AND FRIDAY...FELT IT PRUDENT TO GO WITH A MENTION OF STRONG THUNDERSTORM ACTIVITY IN THE HWO FOR THURSDAY EVENING AS WELL AS FRIDAY AFTERNOON AND EVENING. MUCH WARMER WEATHER IS STILL EXPECTED DURING THE LONG-TERM FORECAST PERIOD...WITH HIGHS GENERALLY IN THE UPPER 80S AND 90S ON MOST DAYS...AND PERHAPS APPROACHING 100 DEGREES FOR SOME LOCATIONS ON FRIDAY. GUIDANCE ALSO SUGGESTS BOUNDARY-LAYER DEW POINTS IN THE UPPER 60S TO MID 70S WILL HELP PROMOTE HEAT INDEX READINGS NEAR 100 DEGREES FOR PORTIONS OF THE OUTLOOK AREA BOTH THURSDAY AND SATURDAY...AND AROUND 105 DEGREES ON FRIDAY. WILL GO AHEAD AND CONTINUE WITH THE HEAT INDEX WORDING IN THE HWO AS A RESULT. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1159 PM CDT TUE JUL 21 2015 VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS. HIGH-LEVEL CLOUDS...NEAR 15000FT AGL...WILL REMAIN POSSIBLE DURING THE TAF PERIOD. THE SURFACE WIND WILL REMAIN FROM THE SOUTHEAST AT 5-10KTS...AND VISIBILITY RESTRICTION IS NOT CURRENTLY EXPECTED THROUGH THE NEXT 24 HOURS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...GUERRERO LONG TERM...BRYANT AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1235 AM EDT WED JUL 22 2015 .SYNOPSIS...A WEAK COLD FRONT WILL DROP INTO THE REGION LATE TONIGHT AND WEDNESDAY BRINGING A SLIGHT REDUCTION IN THE HEAT. THE FRONT WILL PUSH OFF TO THE SOUTH BY FRIDAY...WITH A DRYING TREND EXPECTED THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 1230 AM WEDNESDAY...HAVE ADDED A SWATH OF 30-60 POPS FROM THE WHITEVILLE-LAKE WACCAMAW AREA EAST INTO WILMINGTON WITH A PERSISTENT BAND OF SHOWERS AND TSTORMS MOVING EAST AT AROUND 20 MPH. COMPARED TO THE DEEP CONVECTION THAT MOVED ACROSS SAMPSON...PENDER AND DUPLIN COUNTIES OVER THE NEXT FEW HOURS THIS IS WEAKER AND MORE LIMITED IN VERTICAL DEPTH BUT STILL CAPABLE OF DROPPING LOCALLY HEAVY RAINFALL AND PRODUCING LIGHTNING. ISOLATED SHOWERS JUST NORTH OF DARLINGTON MAY HAVE A TOUGHER TIME HOLDING TOGETHER. REGARDLESS...SHOWERS AND STORMS SHOULD SHIFT OFFSHORE IN THE 3-5 AM TIMEFRAME WITH CONVECTIVE DEBRIS CLOUDINESS SLOWLY DIMINISHING. DISCUSSION FROM 1030 PM FOLLOWS... THE FA IS UNDER THE SOUTHERN END OF A BROKEN LINE OF CONVECTION PUSHING ACROSS THE NORTHERN PORTIONS OF THE ILM CWA...AND SHOULD BE OFF THE COAST AROUND OR JUST AFTER MIDNIGHT. HAVE UPDATED POPS TO ACCOUNT THE ISOLATED CONVECTIVE NATURE ELSEWHERE ACROSS THE ILM CWA. THE SFC TROF/COOL FRONT COMBO ORIENTED ENE-WSW...SHOULD PUSH TO OR JUST OFF THE ILM CWA COASTS AROUND OR JUST AFTER DAYBREAK. LOOK FOR WINDS TO VEER TO THE NW TO N AFTER THIS BOUNDARIES PASSAGE. IN FACT...HAVE INCLUDED SOME PATCHY FOG ACROSS AREAS...ESPECIALLY LOCATIONS HAVING RECEIVED RAINFALL. TEMPS/DEWPTS RELATIVELY UNCHANGED FROM PREVIOUS UPDATE. OVERALL...HRRR MODEL HAD THE GENERAL TRENDS WITH THE PASSAGE OF CONVECTION ACROSS THE FA...WITH THE WORSE CONVECTION N THRU NE OF THE ILM CWA. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...BOTH THE GFS AND NAM SHOW A COLD FRONT APPROACHING THE COAST AT SUNRISE IN THE MORNING AND IS EXPECTED TO STALL ALONG THE SOUTHERN BORDER OF THE FORECAST AREA. A LOW IS FORECAST TO DEVELOP ALONG THE FRONT ON THURSDAY MORNING WILL PUSH THIS FRONT FARTHER TO THE SOUTH. THE EXPECTATIONS OF THIS FRONT IS TO SLIGHT BREAK IN THE HIGHER TEMPERATURES WE HAVE SEEN THE LAST SEVERAL DAYS. AREAS SOUTHWEST OF A LINE FROM DARLINGTON TO GEORGETOWN WILL HAVE WAIT AS TEMPERATURES ARE EXPECTED TO BE IN THE MIDDLE 90S AGAIN ON WEDNESDAY WITH THE LOWER 90S ELSEWHERE. ON THURSDAY TEMPERATURES ARE EXPECTED TO RANGE FROM NEAR 90 IN THE NORTHERN SECTIONS OF SOUTHEAST NORTH CAROLINA TO THE 92 TO 95 RANGE ACROSS SOUTHERN PORTIONS OF NORTHEAST SOUTH CAROLINA. WITH THE FRONTAL PASSAGE A 20 TO 30 PERCENT CHANCE OF THUNDERSTORMS IS EXPECTED ON WEDNESDAY AND CHANCES WILL INCREASE TO A 40 TO 50 PERCENT CHANCE WITH THE LOW RIDING ALONG THE COLD FRONT WEDNESDAY NIGHT INTO THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...THE MID LEVEL PATTERN WILL CONSIST OF STRONG RIDGING ACROSS THE FOUR CORNERS OF THE U.S WITH TROUGHING ACROSS THE EAST...AT LEAST INITIALLY. THE RIDGE WILL BUILD BACK TO THE EAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK LEAVING A WEAKER NORTHWEST FLOW ACROSS THE EASTERN CAROLINAS. THERE ARE INDICATIONS IN SOME OF THE GUIDANCE THAT A COUPLE OF STRONGER SHORTWAVES WILL MOVE ACROSS THIS FLOW NEXT TUESDAY THUS INCREASING THE CHANCE OF CONVECTION. THE HIGHEST POPS OF THE PERIOD WILL RESIDE HERE. FOR FRIDAY TROUGH MONDAY WEAK HIGH PRESSURE IN THE WAKE OF THE MID LEVEL TROUGH WILL KEEP CONDITIONS MOSTLY DRY WITH PRECIPITABLE WATER VALUES WELL BELOW 1.5 INCHES. TEMPERATURES WILL BE AT OR NEAR CLIMATOLOGY THROUGHOUT THE PERIOD. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...SOUTHWARD-DRIFTING COLD FRONT OVER SOUTHERN SOUTH CAROLINA WILL PUSH THROUGH THE AREA OVER THE NEXT 4-6 HOURS. HEAVIEST THUNDERSTORMS HAVE MOVED TOWARD THE SOUTHERN OUTER BANKS...BUT NEW STORMS WILL PROBABLY STILL AFFECT THE ILM AIRPORT OVER THE NEXT HOUR. AREAS THAT RECEIVED RAIN MAY SEE SOME FOG...PREDOMINATELY MVFR. WINDS SHIFT TO THE NORTH TOWARD DAYBREAK AS THE FRONT DROPS SOUTH. CONVECTION WILL BE ISOLATED AT BEST LATER THIS AFTERNOON...WITH CHANCES MAINLY CONFINED TO THE MYRTLE BEACH & FLORENCE AREA. EXTENDED OUTLOOK...A GOOD CHANCE FOR SHOWERS AND STORMS THURSDAY AND FRIDAY AS THE FRONT WAVES BACK NORTH. FRONT DROPS BACK SOUTH AGAIN FRIDAY EVENING WITH VFR CONDITIONS SATURDAY AND SUNDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1230 AM WEDNESDAY...HAVE ISSUED AN EXERCISE CAUTION HEADLINE FOR THE NC WATERS. SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY OCCURRING NEAR 20 MILES FROM SHORE AT THIS TIME...BUT THE TREND SHOULD BE TOWARD RAPID IMPROVEMENT AS WINDS SHIFT MORE WESTERLY AND DIMINISH IN STRENGTH. LATEST SEAS AT THE HARBOR BUOY SOUTH OF SOUTHPORT WERE 5.5 FEET...WITH 4 FOOT SEAS AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY. OFFSHORE THE FRYING PAN SHOALS BUOY HAS HAD 6 FOOT SEAS SINCE 9 PM EDT. DISCUSSION FROM 1000 PM FOLLOWS... BASED ON LATEST WIND AND SEAS REPORTS/TRENDS AND HRRR PROGRESSION OF WX FEATURES...HAVE TWEAKED BOTH WIND AND SIGNIFICANT SEAS FOR THE REMAINDER OF THIS EVENING AND OVERNIGHT. LOOKING AT MAINLY A SLOW VEERING WIND DIRECTION CHANGE AFTER MIDNIGHT THROUGH THE PRE-DAWN WED HOURS. WILL LIKELY SEE W-NW WIND DIRECTIONS BY DAYBREAK WED. WIND SPEEDS WILL BE SLOWER TO DROP DUE TO THE SLOWER PROGRESSION OF THE SFC TROF AXIS TO AND EVENTUALLY ACROSS THE AREA WATERS...MORE-SO OCCURRING AFTER DAYBREAK WED. SIGNIFICANT SEAS ALSO A BIT SLOWER TO SUBSIDE. WIND DRIVEN WAVES AT 4 TO 5 SECOND PERIODS TO DOMINATE THE SIGNIFICANT SEAS WITH A CONTINUED UNDERLYING LAZY 1 FOOT OR LESS SE GROUND SWELL. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...A COLD FRONT WILL APPROACH THE WATERS EARLY WEDNESDAY MORNING AND SLOWLY MOVE ACROSS ALONG THE COASTAL WATERS TO JUST SOUTH OF THE LOWER SANTEE. A LOW PRESSURE AREA IS EXPECTED TO DEVELOP ALONG THE FRONT OVERNIGHT WEDNESDAY AND DRIVE THIS FRONT FARTHER SOUTH. WINDS ARE EXPECTED TO BE SWITCHING TO THE THE NORTHWEST TO WEST BY MORNING TO MID-MORNING WITH SPEEDS AROUND 10 TO 15 KNOTS. BY THURSDAY NIGHT WINDS WILL BE BACK FROM THE SOUTHWEST AT 10 TO 15 KNOTS. SEAS WILL RANGE BETWEEN 2 TO 4 FEET THROUGHOUT THE PERIOD. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...WEAK HIGH PRESSURE WILL RESIDE ALONG THE APPALACHIANS FRIDAY AND SATURDAY. THIS WILL BRING A NORTHEASTERLY FLOW OF TEN KNOTS OR SO TO THE WATERS THROUGH SATURDAY. BY SUNDAY THE HIGH WEAKENS SUFFICIENTLY WITH A VERY WEAK PRESSURE PATTERN ENSUING. A MORE EAST TO SOUTHEASTERLY ONSHORE FLOW WILL DEVELOP MAINLY DUE TO THE SEA BREEZE. SEAS...REMAINING WEAKLY FORCED THROUGH THE PERIOD WILL BE 1-3 FEET FOR THE MOST PART. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...TRA NEAR TERM...DCH/TRA SHORT TERM...DRH LONG TERM...SHK AVIATION...DL/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
346 AM CDT WED JUL 22 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 317 AM CDT WED JUL 22 2015 THUNDERSTORMS WILL BE THE FOCUS FOR THE SHORT TERM. A WARM FRONT WILL CONTINUE TO LIFT NORTHEAST ACROSS THE STATE THIS MORNING. ISOLATED THUNDERSTORMS MAY DEVELOP ALONG THE FRONT THROUGH THE MORNING HOURS ACROSS THE JAMES VALLEY. THE LATEST (7UTC) HRRR IS A LITTLE TOO ROBUST WITH THUNDERSTORM DEVELOPMENT ACROSS THE VALLEY AS IT HAS THUNDERSTORMS ACROSS PORTIONS OF LOGAN...MCINTOSH...LAMOURE AND DICKEY COUNTIES...YET CURRENT RADAR TRENDS INDICATE ONLY ISOLATED THUNDERSTORMS WELL TO THE EAST. A COLD FRONT AND SURFACE TROUGH WILL SLOWLY ENTER WESTERN NORTH DAKOTA THIS EVENING/OVERNIGHT. SHOWERS AND THUNDERSTORMS ARE SHOWN DEVELOPING ALONG THE FRONT IN THE HRRR/RAP/WRF/NAM. SCATTERED STORMS ARE POSSIBLE THROUGH THE NIGHT ACROSS WESTERN NORTH DAKOTA. TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGREES WARMER THAN YESTERDAY AS WAA CONTINUES AND WE BECOME FULLY ENTRENCHED IN THE WARM SECTOR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 317 AM CDT WED JUL 22 2015 MAIN FORECAST ISSUE CONTINUES TO BE THUNDERSTORM TIMING...COVERAGE AND POSSIBILITY OF SEVERE ON THURSDAY. MODELS ARE GENERALLY ON THE SAME TRACK...ALTHOUGH GFS HAS A SLIGHTLY FARTHER NORTHWARD PLACEMENT OF QPF COMPARED TO NAM/ECMWF/SREF. GFS APPEARS TO HAVE A SLIGHTLY WEAKER VORT MAX MOVING ACROSS SOUTHWESTERN AND CENTRAL ND IN WEST/SOUTHWEST FLOW. FOR THE FORECAST...FOLLOWED THE NAM/ECMWF SOLUTIONS WITH A MORE SOUTHWARD DEVELOPMENT OF CONVECTION WHICH IS ALSO MORE IN LINE WITH THE SPC DAY 2 CONVECTIVE OUTLOOK SHOWING SLIGHT RISK OF SEVERE THUNDERSTORM AREA OVER ALL BUT FAR WESTERN ND ON THURSDAY. ALL MODELS FORECAST AMPLE INSTABILITY WITH UPWARDS OF 2000-3000 J/KG OF SURFACE BASED CAPE ACROSS CENTRAL AND EASTERN ND BY 18Z WITH SURFACE LOW AND ASSOCIATED COLD FRONT INTO WESTERN ND...WHICH WILL SERVE AS A FOCUS FOR CONVECTIVE DEVELOPMENT. 0-6KM SHEAR STARTS OUT AROUND 20-25KTS AT 18Z THU PER GFS/NAM WITH STRONGER VALUES DISPLACED WEST OF BEST CAPE...EVENTUALLY INCREASING TO 30-35KTS BY THURSDAY EVENING ACROSS THE STATE. STORMS SHOULD BE EXITING EASTERN CWA BETWEEN 06Z AND 12Z FRIDAY. QUASI-ZONAL FLOW DEVELOPS THROUGH EARLY WEEKEND BEFORE A DEEPER LONGWAVE TROUGH MOVES THROUGH THE PAC NW BRINGING ANOTHER LOW PRESSURE SYSTEM THROUGH MONTANA...BRUSHING WESTERN ND AND INTO SOUTHERN CANADA. OVERALL WILL CONTINUE TO SEE PERIODIC...GENERALLY LOW CHANCES OF PRECIP THROUGH REMAINDER OF EXTENDED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1218 AM CDT WED JUL 22 2015 VFR CONDITIONS AT ALL TAF SITES THROUGH THE PERIOD. SHOWERS AND THUNDERSTORMS MAY IMPACT KJMS THIS MORNING...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH TO WARRANT MENTION IN THE TAF AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...AJ LONG TERM...JNS AVIATION...AJ
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1223 AM CDT WED JUL 22 2015 .UPDATE... ISSUED AT 1218 AM CDT WED JUL 22 2015 MINOR UPDATE TO TRIM POPS FURTHER EAST AND SLIGHTLY ADJUST TEMPERATURES TO MATCH CURRENT TRENDS. LATEST RADAR AND SHORT TERM MODELS INDICATE VERY LITTLE PRECIP UNTIL THE MORNING HOURS. UPDATE ISSUED AT 938 PM CDT TUE JUL 21 2015 TRIMMED POPS AGAIN CENTRAL FOR TONIGHT BASED ON LATEST RADAR AND SATELLITE TRENDS. HRRR CONTINUES TO TO HOLD ONTO SOME CONVECTION WEST TONIGHT. BUT HAVE DOUBTS ABOUT THIS. INSTEAD WILL FOCUS ON THE JAMES RIVER VALLEY WHERE LIFT OVER THE WARM FRONT SHOULD PROVIDE MORE FOCUS FOR CONVECTION TONIGHT. UPDATE ISSUED AT 644 PM CDT TUE JUL 21 2015 LATEST HRRR RUN HINTS AT EXPANDING THE CONVECTIVE CLUSTER NORTHWARD INTO SOUTH CENTRAL NORTH DAKOTA DURING THE NEXT FEW HOURS ALONG AND NORTH OF THE WARM FRONTAL BOUNDARY. THIS MAY BE A LITTLE OPTIMISTIC CONSIDERING RADAR AND SATELLITE TRENDS. WILL TRIM POPS BACK ACROSS THE WEST AND CENTRAL THIS EVENING. HOWEVER WILL LEAVE THE TREND OF INCREASING POPS THIS EVENING ACROSS THE JAMES RIVER VALLEY IN PLACE FOR NOW. && .SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY AFTERNOON) ISSUED AT 253 PM CDT TUE JUL 21 2015 FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE SLIGHT CHANCES FOR THUNDERSTORMS MAINLY TODAY AND TONIGHT...FOLLOWED BY ANOTHER WARM DAY WEDNESDAY...THIS TIME MORE HUMID. CURRENTLY...WEAK MID LEVEL RIDGE AXIS OFF TO OUR WEST WITH A DEVELOPING SFC TROUGH OVER THE NORTHERN HIGH PLAINS. A FEW SCATTERED SHOWERS ABOUT...OVER MY FAR SOUTH AND EASTERN COUNTIES. LACK OF INSTABILITY CENTRAL AND EAST SO REMOVED THUNDER MENTION FOR THE DURATION OF TODAY FOR ALL BUT THE SOUTHWEST. WARM FRONT SLOWLY LIFTING NORTH INTO WESTERN AND SOUTHERN NORTH DAKOTA. WITH A DECENT SOUTHERLY MIXING FLOW COUPLED WITH CLEARING SKIES AND WAA...TEMPERATURES HAVE WARMED NICELY INTO THE 80S. COOLER WHERE CLOUD COVER REMAINS. HIGH RES MODELS STILL INDICATE A DESTABILIZING ATMOSPHERE MID TO LATE AFTERNOON WITH INCREASING THUNDERSTORM CHANCES ACROSS THE FAR SOUTHWEST AND FAR SOUTH CENTRAL INITIALLY NEAR THE WARM FRONT AND IN PROXIMITY TO A MID LEVEL WAVE OVER SOUTH DAKOTA. MODELS THEN HAVE THIS ACTIVITY SPREADING NORTH AND EAST WITH TIME IN THE EVENING. COVERAGE STILL REMAINS VERY UNCERTAIN WITH LATEST NSHARP ANALYSIS STILL SHOWING A CAPPING INVERSION IN PLACE ACROSS THE SOUTH WHERE CLOUDS REMAIN. DUE TO THIS AND LITTLE FORCING ALOFT OPTED TO KEEP OUR POPS SCATTERED TO ISOLATED WITH MOST LOCATIONS STAYING DRY TONIGHT. RIDGE AXIS MOVES EAST TONIGHT BUT REMAINS OVER THE DAKOTAS THROUGH MUCH OF WEDNESDAY. THIS KEEPS THE SFC TROUGH OVER EASTERN PORTIONS OF MONTANA AND WYOMING...AND WILL KEEP NORTH DAKOTA MAINLY DRY THROUGH TOMORROW AFTERNOON. WARM DAY WITH HIGHS WELL INTO THE 80S WITH PERHAPS A FEW LOW 90S WEST. MORE HUMID WEDNESDAY AS SFC DEWPOINTS IN THE 60S ARE TRANSPORTED INTO THE REGION THANKS TO A MID LEVEL SOUTHERLY FLOW STRETCHING AS FAR SOUTH AS THE SOUTHERN PLAINS ALL THE WAY NORTH INTO NORTH DAKOTA. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 253 PM CDT TUE JUL 21 2015 MAIN FORECAST ISSUE IS CONVECTIVE POTENTIAL ON THURSDAY...AND POTENTIAL OF A RISK OF SEVERE THUNDERSTORMS. WEDNESDAY EVENING A SOUTHERLY LOW LEVEL JET IS ESTABLISHED OVER THE EASTERN DAKOTAS WITH A SURFACE TROUGH IN THE LEE OF THE ROCKIES...AND SOUTHERLY SURFACE WINDS DRAWING 60-65F DEWPOINTS INTO THE EASTERN DAKOTAS. AT UPPER LEVELS A RIDGE IS IN PLACE UPSTREAM OF A LARGE UPPER LEVEL TROUGH AXIS OVER THE WEST COAST. AFTER MIDNIGHT WEDNESDAY NIGHT/THURSDAY MORNING...THE UPPER LEVEL RIDGE AXIS MOVES EAST INTO THE EASTERN DAKOTAS...AND THE LEADING EDGE OF UPPER LEVEL IMPULSES MOVING THROUGH THE SOUTHWEST FLOW ALOFT REACHES WESTERN NORTH DAKOTA. KEPT A CHANCE/SLIGHT CHANCE MENTION OF THUNDERSTORMS IN THE WEST LATE WEDNESDAY NIGHT. ON THURSDAY SEVERAL ROUNDS OF UPPER LEVEL IMPULSES MOVE NORTHEASTWARD ACROSS THE STATE IN THE ESTABLISHED SOUTHWEST FLOW ALOFT. AT THE SURFACE...A COLD FRONT AT THE WESTERN BORDER OF THE DAKOTAS THURSDAY MORNING IS FORECAST TO MOVE EAST ACROSS THE STATE THURSDAY AND THURSDAY NIGHT. DEWPOINTS REACH THE UPPER 60S TO AROUND 70 IN CENTRAL NORTH DAKOTA ON THURSDAY. THE SURFACE FRONT WILL BE THE MAIN FOCUS OF THE HIGHEST CAPE VALUES (HIGHEST IN THE AFTERNOON AND EVENING RANGING FROM 3000-5000 J/KG) THROUGH THE DAY AND NIGHT. THE HIGHEST BULK SHEAR VALUES APPEAR TO BE ALONG AND BEHIND THE SURFACE FRONT. THEREFORE THE BEST CHANCE THAT STORMS WOULD REACH SEVERE LEVELS WOULD BE MAINLY ALONG AND EITHER SIDE OF THE SURFACE FRONT. HAVE PUT THE MENTION OF POSSIBLE SEVERE THUNDERSTORMS THURSDAY MORNING IN THE FAR WEST...OVER ALL OF CENTRAL AND WESTERN NORTH DAKOTA IN THE AFTERNOON...AND IN CENTRAL NORTH DAKOTA THURSDAY EVENING. WARM AND HUMID WEDNESDAY EVENING AND NIGHT...WITH LOWS IN THE 60S. HOT AND HUMID THURSDAY WITH HIGHS MAINLY FROM THE MID 80S TO LOWER 90S. MAINLY ZONAL WEST-TO-EAST FLOW ALOFT FRIDAY...WITH A WEAK RIDGE BUILDING INTO OUR AREA SATURDAY AND SUNDAY. ONLY SLIGHT CHANCES TO NO CHANCES OF THUNDERSTORMS THESE TWO DAYS FOR A NICE REPRIEVE...ALTHOUGH AN UPPER LEVEL TROUGH IS FORMING OFF THE WEST COAST OVER THE WEEKEND. NOT AS HUMID FRIDAY AND SATURDAY...WITH HIGHS IN THE 80S...BUT INCREASING HUMIDITY ON SUNDAY. MONDAY THROUGH TUESDAY WILL SEE A RETURN OF ACTIVE WEATHER AS THE AFOREMENTIONED WEST COAST TROUGH LIFTS NORTHEASTWARD INTO THE PLAINS...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE BEGINNING OF NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1218 AM CDT WED JUL 22 2015 VFR CONDITIONS AT ALL TAF SITES THROUGH THE PERIOD. SHOWERS AND THUNDERSTORMS MAY IMPACT KJMS THIS MORNING...HOWEVER CONFIDENCE IS NOT HIGH ENOUGH TO WARRANT MENTION IN THE TAF AT THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...NH LONG TERM...JV AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1142 PM CDT TUE JUL 21 2015 .UPDATE... ISSUED AT 1142 PM CDT TUE JUL 21 2015 MADE A FEW MINOR TWEAKS TO FIT RADAR TRENDS...BUT CONTINUE THINK SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP AS WARM AIR ADVECTION INCREASES AND A FEW WEAK SHORTWAVES COME THROUGH. UPDATE ISSUED AT 937 PM CDT TUE JUL 21 2015 MADE A FEW FURTHER TWEAKS TO POPS. THERE CONTINUES TO BE SOME SCATTERED SHOWERS THAT ARE NOW REACHING THE GROUND OVER THE SOUTHERN CWA IN RESPONSE TO A WEAK SHORTWAVE COMING OVER THE TOP OF THE RIDGE. ANOTHER STRONGER SHORTWAVE IS COMING IN FROM THE WEST AND THE LOW LEVEL JET HAS STARTED TO EXTEND INTO CENTRAL ND FROM SD. THE HRRR SEEMS TO HAVE A DECENT HANDLE ON CURRENT ACTIVITY AND IT HAS THE SHOWERS IN THE SOUTH DISSIPATING AND MORE ACTIVITY FIRING JUST WEST OF THE RED RIVER LATER ON DURING THE EARLY MORNING HOURS. RAISED POPS IN THE SOUTH FOR THE NEXT HOUR OR SO AND THEN HAVE ACTIVITY TRANSITIONING FURTHER NORTH FROM THE DEVILS LAKE BASIN INTO THE RED RIVER VALLEY. NOT A LOT OF INSTABILITY TO WORK WITH SO WENT SHOWERS WITH ISOLATED THUNDER. UPDATE ISSUED AT 654 PM CDT TUE JUL 21 2015 TWEAKED POPS A BIT TONIGHT...A FEW STRONGER SHOWERS HAVE STARTED TO MORE INTO THE SOUTHWESTERN CWA...ALTHOUGH MOST OF THE RETURNS ARE NOT REACHING THE GROUND AT THIS POINT. THINK WE WILL GET SOME LIGHT RAIN REACHING THE GROUND EVENTUALLY...ESPECIALLY LATER TONIGHT AS THERE SHOULD BE SOME ACTIVITY ON THE NOSE OF THE LOW LEVEL JET. WILL KEEP SOME SCATTERED POPS GOING OVERNIGHT STARTING IN THE WEST AND TRANSITIONING INTO THE RED RIVER VALLEY TOWARDS MORNING. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT) ISSUED AT 344 PM CDT TUE JUL 21 2015 UPPER AIR PATTERN WAS PROGRESSIVE. UPPER LEVEL RIDGE OVER THE HIGH PLAINS WILL BUILD TONIGHT AND MOVE OVER THE FORECAST AREA BY 12Z THU. PRECIPITABLE WATER RISES TO OVER AN INCH THIS AFTERNOON AS CROSS SECTION INDICATES MID LEVEL MOISTURE TO MOVE IN. BIS SOUNDING INDICATED MUCH OF THE MOISTURE WAS MOVING IN BETWEEN 750 AND 550 HPA. LOW LEVEL MOISTURE TO FOLLOW ON THU. UPPER LEVEL TROUGH OFF THE WEST COAST WILL MOVE ACROSS THE NORTHERN PLAINS AROUND 84 HOURS AS UPSTREAM TROUGH MOVES INTO THE GULF OF AK. PRECIPITABLE WATER RISES TO 1.5 TO 2 INCHES BY LATE THU. NAM AND GFS SHOWALTERS BECOME QUITE NEGATIVE FOR THU NIGHT WHILE THE ECMWF WAS MUCH LESS NEGATIVE. MODEL SOUNDINGS SHOW WARM MID LEVEL TEMPS IN PLACE THU AFTERNOON WILL CAP ATMOSPHERE PRE-FRONTALLY. 700 HPA TEMPS RISE ABOVE 10C. MID LEVEL TEMPS RISE WED NIGHT AND BEGIN TO CAP ATMOSPHERE. THUNDERSTORMS SHOULD OCCUR NEAR OR POST FRONTAL WITH SURFACE TROUGH MOVING THROUGH THU NIGHT. WILL ADD SEVERE WORDING FOR THU NIGHT. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 344 PM CDT TUE JUL 21 2015 FOR FRI NIGHT THROUGH TUE...TEMPS SHOULD REMAIN ABOVE NORMAL THROUGH AT LEAST THIS WEEKEND INTO EARLY NEXT WEEK. THE BEST CHANCE FOR SHOWERS AND STORMS SHOULD OCCUR EARLY NEXT WEEK AHEAD OF A COLD FRONT...WITH A DRY WEEKEND EXPECTED FOR THE MOST PART. BOTH THE GFS AND ECMWF INDICATE A SW FLOW ON MON NIGHT INTO TUE WITH A MORE WIDEPSREAD CONVECTIVE EVENT POSSIBLE...DEPENDING ON EXACT TIMING OF SHORTWAVE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1142 PM CDT TUE JUL 21 2015 VFR CONDITIONS WILL CONTINUE THROUGHOUT THE PERIOD WITH CIGS AROUND 8000 FT AND ABOVE FOR THE MOST PART. SOME SCATTERED SHOWERS IMPACTING KFAR AND KDVL WILL MOVE SLOWLY NORTHEASTWARD...AND SHOULD BE NEAR KGFK AND KTVF BY EARLY MORNING HOURS. SOME SHOWERS ARE POSSIBLE NEAR KBJI AFTER SUNRISE BUT THERE IS QUITE A BIT OF UNCERTAINTY SO WILL LEAVE IT OUT FOR NOW. WINDS WILL BE LIGHT AND VARIABLE FOR THE FIRST FEW HOURS BEFORE COMING OUT OF THE SOUTH AND INCREASING TO ABOVE 10 KTS LATE IN THE PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...HOPPES LONG TERM...DK AVIATION...JR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
437 AM EDT WED JUL 22 2015 .SYNOPSIS... HIGH PRESSURE BUILDING INTO THE NORTHEAST WILL USHER IN COMFORTABLE TEMPERATURES AND LOW HUMIDITY RIGHT THROUGH SATURDAY. THE NEXT CHANCE OF SHOWERS WILL ARRIVE LATE SATURDAY NIGHT OR SUNDAY AS A WEAK COLD FRONTAL SYSTEM DRIFTS SOUTHEAST FROM THE GREAT LAKES REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE COLD FRONT THAT BROUGHT A BROKEN LINE OF BRIEF SHOWERS AND THUNDERSTORMS TO THE REGION LATE TUESDAY AFTERNOON AND EVENING...NOW STRETCHES FROM LONG ISLAND TO CENTRAL VA. LLVL RIDGING AND GRADUALLY RISING HEIGHTS IN THE WAKE OF THIS FRONT WILL LEAD TO CLEAR TO PTLY CLOUDY SKIES FOR PRACTICALLY ALL OF THE CWA THIS MORNING...COMPLETE WITH REFRESHINGLY COOLER AND LESS HUMID AIR. THE LONE...SMALL FRUIT FLY IN THE OINTMENT COMES IN THE FORM OF A WELL-DEFINED/BUT RATHER COMPACT MID-LEVEL THERMAL TROUGH AND RIGHT ENTRANCE REGION OF A 90 KT 300 MB JETLET...THAT WAS FOCUSED OVER EASTERN LAKE ERIE AT 08Z. THIS SMALL POCKET OF INSTABILITY AND UVVEL WILL SLIDE EAST AND WEAKEN GRADUALLY TODAY. SOME BKN-OVC HIGH-BASED STRATO CU AND ALTO CU WILL BE ACCOMPANIED BY A FEW SPRINKLES OR EVEN A BRIEF SHOWERS ACROSS OUR FAR NW CWA. LATEST SEVERAL RUNS OF THE HRRR INDICATE THIS SPOTTY AND VERY MINOR QPF POTENTIAL. THE AREA OF HIGH PRESSURE AND MUCH DRIER AIR MASS WILL SET UP RESIDENCE FOR SEVERAL DAYS AS THE PATTERN OVER NOAM SHIFTS FROM THE UNPLEASANTLY HUMID/WET WITH MEAN UPPER RIDGE LOCATED OVER THE UPPER MIDWEST. MIN TEMPS EARLY THIS WEDNESDAY WILL VARY FROM THE LOWER 50S NORTH...TO THE LOWER 60S THROUGHOUT THE LOWER SUSQ VALLEY. HIGH PRESSURE AND ANOMALOUSLY LOW PW WILL SPELL A GEM OF A DAY TODAY...AS A DEEP UPPER LOW OVER SERN CANADA AND NWRLY UPPER FLOW ACROSS PENN DELIVERS A MORE REFRESHING CANADIAN AIR TO THE REGION...GIVING US A BREAK FROM THE RECENT 8 WEEKS OF FREQUENTLY HUMID AND WET WEATHER. A NW BREEZE...FRESHENING TO 8-12 KTS /WITH A FEW GUSTS INTO THE MID TEENS/ WILL COMBINE WITH LOW DEWPOINTS...AND MAX TEMPS RANGING FROM THE MID 70S NORTH TO THE LOWER 80S IN THE SOUTHEAST /JUST A FEW DEG F BELOW NORMAL/. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... HIGH PRESSURE WILL BE MOVING INTO WRN PENN TONIGHT. THIS WEATHER FEATURE WILL BRING CLEAR SKIES /AND JUST A LIGHT NW BREEZE EARLY TONIGHT/. AN EVEN COOLER NIGHT IS ON TAP...WITH MINS EARLY THURSDAY RANGING FROM THE U40S TO L50S ACROSS THE NRN MTNS AND COLD SPOTS THROUGHOUT THE LAUREL HIGHLANDS...TO THE U50S IN THE LOWER SUSQ VALLEY. THE COOL AIR TEMPS AND WARM WATER TEMPS MAY YIELD SOME PATCHY 2SM RIVER VALLEY FOG UP NORTH BETWEEN 08-12Z THUR. ANOTHER SPLENDID MID SUMMER DAY FOR THURSDAY...UNDER SFC HIGH PRESSURE AND NW FLOW ALOFT. AFTERNOON HIGH TEMPS WILL BE JUST 1-3 DEG F SHY OF NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... 1016-1018 MB SFC HIGH PRESSURE LOCATED NEAR THE PA/OHIO BORDER TO START THE PERIOD...WILL DRIFT EAST ACROSS THE FCST AREA FRI NIGHT AND SATURDAY. THIS DOMINANT WEATHER FEATURE WILL PROVIDE FAIR WEATHER WITH MAINLY LIGHT WIND...CONTINUED COMFORTABLY LOW DAYTIME HUMIDITY...AND MAX TEMPS NEAR TO SLIGHTLY ABOVE NORMAL. THE NEXT CHANCE OF A SHOWER OR THUNDERSTORM WILL BE MAINLY AFTER 00Z SUNDAY...AS LOW-MID LEVEL WARM ADVECTION AND INCREASING SHEAR DEVELOPS. THE BULK OF THIS PRECIP POTENTIAL WILL BE MAINLY SUNDAY AND MONDAY. WENT DRY FOR TUE...AS THE NEXT HIGH PRESSURE SYSTEM BUILDS SE. ENJOY THE NICE WEATHER. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... MID CLOUD DECK SLIDING OFF LAKE ERIE INTO WESTERN NY STATE AS COOL POOL ALOFT EVEN GENERATES A COUPLE OF SHOWERS. PROB REMAINS REMOTE THAT ONE OF THESE WILL SNEAK TOWARDS KBFD. ELSEWHERE... PREDOMINANTLY CLEAR SKIES AND LIGHT WINDS BEHIND LATEST FRONTAL PASSAGE /TUE AFT AND EVE/ MARK THE BEGINNING OF A PROLONGED PERIOD OF EXCELLENT FLYING CONDITIONS AND DRY WEATHER THAT WILL EXTEND INTO SAT. BIGGEST FORECAST CONCERN TODAY WILL BE NW WINDS INCREASING TO 10 MPH WITH GUSTS TO 20 MPH FROM LATE MORNING THROUGH THE AFTERNOON. WINDS SUBSIDE AROUND SUNSET. OUTLOOK... THU-SAT...MAINLY VFR. LOCAL A.M. FOG POSS NORTH. SAT NIGHT-SUN...CHC SHRA/TSTM. MVFR CIGS POSS NW. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1140 PM CDT TUE JUL 21 2015 .AVIATION... VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR THE NEXT 24 HOURS WITH JUST A SLIM CHANCE OF A T-STORM IN THE VICINITY OF ANY OF THE TERMINALS THROUGH ABOUT 11 OR 12 UTC...THEN AT KLBB AND KPVW WEDNESDAY EVENING. && .PREV DISCUSSION... /ISSUED 918 PM CDT TUE JUL 21 2015/ UPDATE... T-STORM ACTIVITY THIS EVENING HAS PRETTY MUCH BEEN LIMITED TO THE VICINITY OF THE FRONTAL ZONE ARCING NEWD FROM SOUTHWEST TEXAS TO NORTH TEXAS/RED RIVER VALLEY. MOST OF THE STORMS MOVING OFF THE HIGHER TERRAIN OF NEW MEXICO HAVE DIED OFF IN THE FACE OF COOLER TEMPERATURES/WEAKER INSTABILITY AND SOME SUBSIDENCE IN THE WAKE OF A SHORTWAVE BEHIND AN EXITING SHORTWAVE. KAMA 00 UTC SOUNDING SHOWED A PRETTY STOUT INVERSION AROUND 700 MB. DESPITE THIS...WE CAN/T COMPLETELY RULE OUT ISOLATED T-STORMS ALMOST ANYWHERE ACROSS THE FORECAST AREA TONIGHT DUE TO THE MOIST ATMOSPHERE AND SOME WEAK ASCENT ALONG THE REMNANT FRONTAL ZONE LIFTING NORTHWARD. WE HAVE UPDATED POPS AND WEATHER TO ACCOUNT FOR THESE TRENDS. PREV DISCUSSION... /ISSUED 629 PM CDT TUE JUL 21 2015/ AVIATION... THE MAIN AVIATION CONCERN IS THE POSSIBILITY OF TSRA IN THE VICINITY OF ALL TERMINALS THROUGH ABOUT 07 OR 08 UTC. AT THIS TIME...CONFIDENCE IS TOO LOW TO PINPOINT A PARTICULAR TIME OR AREA SO WE KEPT THE MENTION OUT OF THE TAF. LIGHT AND VARIABLE SURFACE WINDS WILL GRADUALLY COME AROUND TO THE S-SW AND INCREASE ON WEDNESDAY. THUNDERSTORMS MAY BE A CONCERN AT SOME TERMINALS WEDNESDAY AFTERNOON. PREV DISCUSSION... /ISSUED 315 PM CDT TUE JUL 21 2015/ SHORT TERM... MORE RAIN IS EXPECTED AGAIN LATER THIS AFTERNOON AND EVENING FOR WEST TEXAS...THIS TIME WITH A BIT MORE COVERAGE THAN LAST NIGHT IF THE FORECAST PANS OUT AS EXPECTED. MODELS PRE-12Z WERE VERY SKEPTICAL AND DIFFERED GREATLY ON WHERE AND WHEN CONVECTION WOULD OCCUR LATER TODAY. WHILE SOME QUESTIONS STILL REMAIN...MOST MODELS MINUS THE HRRR HAVE COME INTO AGREEMENT THAT CONVECTION SHOULD SPREAD FARTHER SOUTH AND EAST THAN YESTERDAY AFTERNOON. THE 12Z NAM SEEMED TO HAVE AT FIRST GLANCE THE BEST HANDLE ON THE FORECAST AS IT PICKED UP ON AN AREA OF LIFT OVER SOUTH-CENTRAL NM WHICH STARTED TO SHOW UP ON WV JUST AFTER 13Z. THE AREA OF LIFT HAS SINCE ENHANCED FURTHER AND HAS AIDED IN THE DEVELOPMENT OF EASTWARD PROPAGATING THUNDERSTORMS JUST EAST OF RUIDOSO NM. THESE STORMS SHOULD GRADUALLY MAKE THEIR WAY TOWARDS THE TX/NM STATE LINE BY THE LATE AFTERNOON/EARLY EVENING. ANOTHER AREA OF INTEREST FOR SHOWER AND THUNDERSTORM DEVELOPMENT IS A WESTWARD PROPAGATING SURFACE BOUNDARY ACROSS THE WESTERN THIRD OF THE FA. HIGHER RES MODELS...EVEN THE HRRR TO AN EXTENT...HAVE HINTED AT CONVECTIVE DEVELOPMENT ALONG THIS BOUNDARY WITHIN THE NEXT FEW HOURS AS MLCAPE INCREASES TO AROUND 1500 J/KG. THE AMOUNT OF CAPE THAT WILL BECOME AVAILABLE WILL DEPEND ON HOW MUCH ADDITIONS SURFACE HEATING CAN BE ACHIEVED AS TEMPS ARE COOLER THAN EXPECTED THIS AFTERNOON DUE TO CLOUD COVER THAT LINGERED INTO MID DAY. THE MAIN THREAT...AS IS USUALLY OUT HERE IN THESE PARTS...FROM CONVECTION WOULD BE STRONG TO POSSIBLY MARGINALLY SEVERE WINDS ASSOCIATED WITH DOWNBURSTS. HEAVY RAIN WILL ALSO BE A VALID THREAT AS WAS SEEN YESTERDAY EVENING. RAIN CHANCES WILL DIMINISH OVERNIGHT AS THE ATMOSPHERE COOLS AND STABILIZES. THE RIDGE WILL SLOWLY PUSH BACK INTO THE REGION MAKING WAY FOR HEIGHT RISES TOMORROW WHICH WILL GREATLY DECREASE STORM CHANCES ACROSS THE FA TOMORROW AFTERNOON. THE BEST CHANCES WILL BE IN OUR WESTERN ZONES WHICH WILL BE LOCATED NEAR THE WESTERN EDGE OF THE RIDGE. HIGH TEMPS TOMORROW WILL BE DEPENDENT UPON CONVECTIVE COVERAGE TONIGHT WHICH COULD COOL TEMPS BY SEVERAL DEGREES. FOR NOW MID 90S ON THE CAPROCK/UPPER 90S ACROSS THE ROLLING PLAINS WILL BE MAINTAINED. ALDRICH LONG TERM... CHANCES OF PRECIPITATION WILL BE FLEETING BY THURSDAY AFTERNOON ON THE WESTERN EDGE OF AN UPPER LEVEL RIDGE MOVING OVERHEAD. HEIGHT RISES WILL LIKELY SQUASH ANY CONVECTION LOCALLY. AFTERNOON/EVENING STORMS ARE STILL LIKELY ACROSS NEW MEXICO WITHIN SURFACE TROUGHING WELL WEST OF THE REGION. THERE IS SOME CHANCE BUT VERY LITTLE OF ANY STORMS BEING ABLE TO CROSS STATE LINES THROUGH EARLY NEXT WEEK. LATEST MOS GUIDANCE HAS CONTINUED ITS WARM BIAS ON MAX TEMPERATURES AND WILL CONTINUE TO FORECAST BELOW MOS...CLOSER TO BIAS CORRECTED GUIDANCE. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 64 90 67 94 / 30 20 20 20 TULIA 66 92 69 95 / 30 10 20 10 PLAINVIEW 68 91 70 94 / 20 10 20 0 LEVELLAND 68 93 71 95 / 20 20 20 10 LUBBOCK 72 94 72 97 / 20 20 10 0 DENVER CITY 69 94 70 95 / 30 20 20 20 BROWNFIELD 69 94 71 96 / 20 20 20 0 CHILDRESS 73 98 75 101 / 20 10 10 0 SPUR 70 94 73 96 / 20 10 10 0 ASPERMONT 73 98 76 101 / 30 0 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1107 PM CDT TUE JUL 21 2015 .AVIATION... FOR THE 06Z TAFS...LITTLE CHANGE TO PREVIOUS AVIATION AFD. TSTMS HAVE DIMINISHED ACROSS THE AREA...AND REDEVELOPMENT IS UNLIKELY THE REST OF TONIGHT. SOME CONCERN FOR LOW CLOUDS EARLY WED MORNING. HAVE RETAINED A SCT MVFR LAYER FROM PREVIOUS FCST. ISOLD TSTMS MAY DEVELOP LATE WED AFTERNOON AND EVENING. HOWEVER...IF STORMS FORM...COVERAGE SHOULD BE SPARSE. THEREFORE...HAVE OMITTED THAT ELEMENT FROM THIS FCST CYCLE. ANDRADE && .PREV DISCUSSION... /ISSUED 1031 PM CDT TUE JUL 21 2015/ UPDATE... REMOVED POPS REST OF TONIGHT AS VERY LITTLE PRECIPITATION HAS OCCURRED THIS EVENING. REDEVELOPMENT OF SHOWERS AND TSTMS IS NOT EXPECTED THE REMAINDER OF TONIGHT. ANDRADE PREV DISCUSSION... /ISSUED 635 PM CDT TUE JUL 21 2015/ AVIATION... FOR THE 00Z TAFS...SOME POTENTIAL EXISTS FOR ISOLD TO PERHAPS SCT TSTMS TO AFFECT PARTS OF THE OK AND NRN TX PNHDLS THIS EVENING AND TONIGHT. HOWEVER...CONFIDENCE IS LOW AS TO WHETHER KGUY OR KDHT WILL BE IMPACTED SO HAVE OPTED TO OMIT THIS ELEMENT FROM THIS FCST CYCLE. WILL MONITOR TRENDS THIS EVENING FOR PSBL AMENDMENTS. SOME CONCERN FOR LOW CLOUDS LATER TONIGHT INTO EARLY WED MORNING. HAVE KEPT A SCT MVFR DECK FROM PREVIOUS FCST. ANDRADE PREV DISCUSSION... /ISSUED 432 PM CDT TUE JUL 21 2015/ DISCUSSION... PRIMARY FOCUS CONTINUES TO BE POTENTIAL FOR ADDITIONAL FLOODING TONIGHT AS MANY LOCATIONS ARE SATURATED FROM LAST NIGHT. 12Z SOUNDING SHOWS SIGNIFICANT CONVECTIVE OVERTURNING WITH VERY SHALLOW LOW LEVEL MOISTURE AND A MARKED DECREASE IN MOISTURE JUST ABOVE THAT THROUGHOUT THE LOW LEVELS. MID-HIGH LEVEL CLOUDS KEPT THE AREA FROM DESTABILIZATION AS SIGNIFICANTLY AS YESTERDAY AND ABSENCE OF ANY WELL DEFINED SURFACE BOUNDARIES HAS YIELDED A FAIRLY UNIFORM CUMULUS FIELD PER VISIBLE SATELLITE THIS AFTERNOON. SOME TERRAIN INDUCED CONVECTION IN NEW MEXICO HAS FORMED BUT OVERALL EXPANSIVENESS IS FAR LESS THAN YESTERDAY AT THIS TIME. WATER VAPOR LOOP AND RAP PV ANALYSIS SHOW ONE WAVE TRAVERSING THE PANHANDLES NOW WITH SUBSIDENCE FOLLOWING THIS FEATURE ALREADY OVERSPREADING THE WESTERN PORTION OF THE AREA. HAVE SIGNIFICANTLY LOWERED PRECIPITATION PROBABILITIES TONIGHT GIVEN TRENDS. MID LEVEL HEIGHTS RISE AS RIDGE ONCE AGAIN AMPLIFIES. THIS SHOULD LIMIT COVERAGE OF CONVECTION FOR MUCH OF THE WEEK. ISOLATED THUNDERSTORMS MAY OCCUR MAINLY OVER THE FAR NORTHWEST PORTION OF THE AREA. THE RIDGE WEAKENS AGAIN SUFFICIENTLY FOR AN INCREASE IN PRECIPITATION PROBABILITIES ESPECIALLY ACROSS THE NORTHERN PORTION OF THE AREA SATURDAY AND SUNDAY. BRB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT TUE JUL 21 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 257 PM CDT TUE JUL 21 2015 PRETTY QUIET WEATHER COMING UP OVER THE NEXT COUPLE OF DAYS. THE SURFACE RIDGE...CURRENTLY CENTERED OVER NORTHWEST IOWA AND SOUTHWEST MINNESOTA...WILL DRIFT EAST AND BECOME CENTERED OVER THE GREAT LAKES REGION WEDNESDAY. THIS HIGH WILL THEN ESSENTIALLY REMAIN STATIONARY THROUGH THURSDAY WHICH WILL CONTINUE TO PROVIDE THE REGION WITH DRY CONDITIONS. WITH THE HIGH MOVING OVER THE AREA...THERE IS SOME SMALL POTENTIAL FOR VALLEY FOG TONIGHT. HOWEVER...THE 21.12Z NAM FORECAST SOUNDINGS ARE NOT THAT FAVORABLE FOR FOG FORMATION. IT SUGGESTS IT WILL COME CLOSE TO SATURATION AT THE SURFACE BUT THEN QUICKLY DRY OUT ABOVE THAT AS THE WEST TO NORTHWEST WINDS JUST ABOVE THE SURFACE INCREASE TO AROUND 10 KNOTS. THE 21.17Z RAP IS EVEN LESS ENTHUSED AS IT SHOWS A 3C TEMP/DEW POINT SPREAD AT 11Z. PREVIOUS FORECAST HAD INTRODUCED SOME PATCHY FOG FOR LATE TONIGHT INTO WEDNESDAY MORNING AND WILL MAINTAIN THIS FOR NOW. OTHERWISE...LOOK FOR TEMPERATURES TO SLOWLY WARM WITH HIGHS IN THE LOWER TO MIDDLE 80S EXPECTED BY THURSDAY AND LOWS OF 60 TO 65 BY THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 257 PM CDT TUE JUL 21 2015 THE NEXT CHANCE FOR SOME RAIN WILL COME IN THE FRIDAY TO SATURDAY TIME FRAME. THE MODELS AGREE THAT A SHORT WAVE TROUGH WILL COME OUT OF THE WESTERN CONUS LONG WAVE TROUGH AND MOVE EAST INTO THE RIDGE AXIS. SOME DIFFERENCES BETWEEN THE 21.12Z ECMWF...GFS AND GEM ON HOW MUCH THIS WAVE WILL BE ABLE TO FLATTEN THE RIDGE. THE GFS IS THE MOST AGGRESSIVE WITH THIS SYSTEM WHICH RESULTS IN THE FLATTEST RIDGE AND THE STRONGEST WAVE COMING ACROSS THE REGION. THE WAVE THE GFS BRINGS THROUGH HAS THE LOOK OF POSSIBLY BEING FROM CONVECTIVE FEEDBACK. THE GEM IS THE WEAKEST WITH THE SYSTEM AND KEEPS MORE RIDGING OVER THE AREA WHILE THE ECMWF IS IN BETWEEN THESE TWO SOLUTIONS BUT LOOKS MORE LIKE THE GEM THAN THE GFS. THE ECMWF HAS STARTED TO BACK OFF FROM THE 21.00Z RUN ON THE AMOUNT AND COVERAGE OF RAIN FOR FRIDAY NIGHT WITH THIS SYSTEM AS THE COLD FRONT COMES THROUGH. BASED ON THIS TREND...CAPPED THE MODEL CONSENSUS GRIDS AT A 60 PERCENT CHANCE OF RAIN...WHICH MAINTAINS PRETTY GOOD CONTINUITY WITH THE PREVIOUS FORECAST. IF THE GFS IS CORRECT...THERE COULD BE SOME SEVERE POTENTIAL WITH THIS SYSTEM AS IT SHOWS AROUND 2000 J/KG OF ML CAPE FRIDAY EVENING DROPPING TO AROUND 1000 J/KG OVERNIGHT. THE 0-6KM SHEAR LOOKS PRETTY WEAK IN THE EVENING BUT COULD INCREASE TO 35 TO 40 KNOTS OVERNIGHT. AFTER THIS SYSTEM...ANOTHER QUICK MOVING SHORT WAVE TROUGH COULD COME ACROSS SATURDAY NIGHT WITH SOME ADDITIONAL RAIN AND THEN THE NEXT SHORT WAVE TROUGH TO POTENTIALLY COME THROUGH RIDGE COULD BE MONDAY NIGHT INTO TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1100 PM CDT TUE JUL 21 2015 A SFC HIGH WILL BE THE MAIN WEATHER FEATURE FOR THE REGION INTO THU...ALTHOUGH A FEW MID/LEVEL CLOUDS COULD SPILL ACROSS THE UPPER LEVEL RIDGE ON WED. VFR CONDITIONS SHOULD PREVAIL. THAT SAID...WITH THE HIGH OVERHEAD AND A LIGHT SFC WIND VALLEY FOG HAS TO BE CONSIDERED. KLSE BUFKIT RAP/HRRR SOUNDINGS SUGGEST A DEEP LIGHT WIND FIELD IN EXCESS OF 8 KFT...BUT KEEP A HEALTHY T/TD SPREAD. NAM12 SIMILAR BUT BRINGS SFC T/TD TOGETHER BY 12Z. EXPECT SOME RIVER VALLEY FOG...BUT HOW WIDESPREAD IN THE MISSISSIPPI IS IN QUESTION. 03Z T/TD SPREAD AT KLSE WAS 9 F...NOT FAVORABLE FOR 1/4SM FG MAKING IT TO THE AIRPORT. WINDS HAVE GONE LIGHT THOUGH. WILL KEEP BCFG AND MONITOR TRENDS FOR POSSIBLE UPDATE IF THE FOG THREAT BECOMES MORE LIKELY. THU MORNING ALSO SHOWING THE POTENTIAL FOR MORE RIVER VALLEY FOG WHICH COULD IMPACT KLSE. THE SFC HIGH IS SHIFTING TO THE SOUTHEAST...BUT DEEP LIGHT WIND LAYER PERSISTS. LINGERING HIGH CLOUDS COULD BE A DETERRENT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
453 AM PDT WED JUL 22 2015 .SYNOPSIS...COOLER THAN NORMAL TEMPERATURES CAN BE EXPECTED INLAND WITH NEAR NORMAL READINGS AT THE COAST FOR THE REST OF THE WEEK. A RIDGE OF HIGH PRESSURE IS ANTICIPATED TO BUILD OVER THE FORECAST AREA NEXT WEEK PROMOTING WARMING TEMPERATURES AND CONTINUED DRY WEATHER. && .DISCUSSION...AS OF 3:00 AM PDT WEDNESDAY...AS FORECAST COOLER AND DRIER AIR HAS SETTLED ACROSS OUR REGION. THANKS TO A MODERATE ONSHORE FLOW AT THE SURFACE PLUS A MARINE LAYER AROUND 1800 FEET SHOULD SEE WIDESPREAD COASTAL CLOUDS TODAY ALONG WITH MANY VALLEY SPOTS. IN OTHER WORDS...A TYPICAL JULY DAY FOR THE SAN FRANCISCO AND MONTEREY BAY REGION. THE ONLY DIFFERENCE WILL BE THE LACK OF STRONG INLAND HEAT DUE TO A LONGWAVE TROF STRETCHING FROM CALIFORNIA INTO WESTERN CANADA. HIGHS WILL BE GENERALLY IN THE 60S TO LOWER 70S AT THE COAST WITH UPPER 70S TO AROUND 90 FOR MOST INLAND SPOTS. SYNOPTICALLY LITTLE WILL CHANGE THROUGH AT LEAST FRIDAY WITH THE TROF OVERHEAD AND PERSISTENT ONSHORE FLOW AT THE SURFACE. MODELS CONTINUE TO SHOW THE POSSIBILITY OF COASTAL DRIZZLE WHICH LINES UP WELL WITH THE PATTERN. HIGHS WILL REMAIN COOLER THAN NORMAL INLAND WHILE COASTAL SPOTS WILL BE NEAR NORMAL. BY THE WEEKEND A RIDGE OF HIGH PRESSURE WILL START TO BUILD BACK TO OUR AREA FROM THE SOUTHEAST. BOTH 500 MB HEIGHTS PLUS 850 MB TEMPS WILL RISE HELPING TO PUSH INLAND HIGHS BACK CLOSER TO NORMAL AT FIRST AND THEN ABOVE NORMAL BY NEXT WORK WEEK. LONGER RANGE OUTLOOK SHOWS ABOVE NORMAL READINGS FOR ALL NEXT WEEK ALONG WITH DRY CONDITIONS AS 500 MB HEIGHTS EXCEED 590 DM AND 850 MB TEMPS APPROACH 25C. && .AVIATION...AS OF 04:50 AM PDT WEDNESDAY... MARINE LAYER STRUGGLING TO GAIN A FOOTHOLD IN THE BAY AREA THIS MORNING AFTER MAKING AN INITIAL PUSH EARLIER IN THE NIGHT. MAJORITY OF SHORT TERM GUIDANCE STRUGGLING NOT KEEPING UP WITH SATELLITE TRENDS... SO HAVE LEANED CLOSER TOWARDS RUC SOLUTION OF BRIEF MVFR CIGS POSBL BTWN 14-15Z FOR BAY AREA. ELSEWHERE... FORT ORD PROFILER SHOWING DEPTH OF MARINE LAYER AROUND 1000 FT WITH BASES AT 1000 FT AND TOPS CLOSE TO 2000 FT. FOG PRODUCT SHOWS MONTEREY BAY AND SALINAS VALLEY COMMUNITIES ARE UNDER MVFR CEILINGS. EXPECT A MID TO LATE MORNING CLEARING FOR MONTEREY BAY. VICINITY OF KSFO... LOW TO MODERATE CONFIDENCE REFLECTED BY TEMPO GROUP THIS MORNING. VFR POSBL THRU MORN AT KSFO. ONSHORE GRADIENTS TIGHTEN THIS AFTERNOON. MARINE LAYER RETURNS TONIGHT. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS... CIGS AROUND 1000 FT THIS MORNING THROUGH 18-19Z... WITH MARINE LAYER RETURNING LATER TODAY AROUND 01Z. && .MARINE...AS OF 04:35 AM PDT WEDNESDAY...APPROACHING TROUGH WILL LEAD TO MODERATE NORTHWEST WINDS THROUGH TODAY WITH THE STRONGEST WINDS OVER THE NORTHERN OUTER WATERS. WINDS OVER THE NORTHERN SAN FRANCISCO BAY WATERS STRENGTHEN THIS AFTERNOON AS THE ONSHORE GRADIENT INCREASES. SEAS REMAIN RELATIVELY CALM. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...SF BAY FROM 2 PM && $$ PUBLIC FORECAST: BELL AVIATION: DRP MARINE: DRP VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1039 AM CDT WED JUL 22 2015 .UPDATE... ISSUED AT 1039 AM CDT WED JUL 22 2015 ANOTHER MOSTLY SUNNY AND DRY DAY IS UNFOLDING ACROSS CENTRAL ILLINOIS TODAY. AFTERNOON HIGH TEMPERATURES WILL BE A DEGREE OR TWO WARMER THAN YESTERDAY...GENERALLY REACHING THE LOWER TO MIDDLE 80S. CURRENT FORECAST IS ON TRACK AND REQUIRES NO UPDATE THIS MORNING. && .SHORT TERM...(TODAY) ISSUED AT 328 AM CDT WED JUL 22 2015 HIGH PRESSURE CENTERED OVER THE MIDWEST EARLY THIS MORNING WILL DOMINATE THE WEATHER OVER MOST OF THE FORECAST AREA THRU THE DAY. HAVE HAD SOME PATCHY FOG DEVELOP OVER PARTS OF THE AREA EARLY THIS MORNING WITH THE HRRR SUGGESTING PARTS OF THE IL RIVER VALLEY AND FROM CMI TO JUST SOUTH OF SPI WILL SEE SOME RESTRICTED VISIBILITIES AT TIMES EARLY THIS MORNING. FORECAST SOUNDINGS AND TIME HEIGHT CROSS SECTIONS INDICATE AN INCREASE IN HIGH LEVEL CLOUD COVER LATER THIS MORNING INTO THE AFTERNOON HOURS AS SHORTWAVE ENERGY TRACKS WELL SOUTH OF THE REGION TODAY. RAP SOUNDINGS INDICATE WE SHOULD MIX DOWN FROM AROUND 800 MB OR APPROX 6000 FEET...WHICH WOULD BRING US AFTERNOON HIGHS IN THE 80 TO 84 DEGREE RANGE. CLOUD COVER SHOULD THICKEN UP EVEN MORE OVER FAR SOUTHEAST IL LATE THIS AFTERNOON AS ADDITIONAL SHORTWAVE ENERGY AND 850-700 MB MOISTURE CONVERGENCE APPROACHES THE I-70 CORRIDOR TOWARDS 00Z. .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 328 AM CDT WED JUL 22 2015 MODELS HAVE SHIFTED CONSIDERABLY WITH THE HANDLING OF THE EXTENDED SUN-WED. IN THE MEANTIME, HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THURSDAY, WITH THE WARMING TREND CONTINUING THROUGH THE END OF THE WEEK AND INTO THE WEEKEND. BROAD UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY. FOR NOW, THE FORECAST IS DRY, BUT THE NAM CONTINUING TO TREND THE TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS WILL REMAIN IN THE FORECAST FOR THU. AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE AXIS DRIFTING OVER THE MIDWEST, TEMPS WARM INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION. HOWEVER, MODELS HIGH TEMPS WILL BE COOLED CONSIDERABLY SHOULD THE PRECIP THAT IS CURRENTLY SHOWING UP IN THE SAT NIGHT-TUES TIME FRAME MATERIALIZES. PREV DRY RUNS UNDER THE EXPANSIVE RIDGE WITH WEAK FLOW ARE LOSING THE DRY FORECAST TO A SERIES OF SMALL WAVES AND WHAT LOOKS LIKE A STALLED BOUNDARY AT THE SFC ALONG THE OHIO RIVER VALLEY SIMILAR TO THE SAME PATTERN REPEATED THROUGH THIS SUMMER. WITH A LACK OF CONTINUITY OR CONSENSUS, SLIGHTS AND LOW CHANCE POPS THROUGH THE END WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 600 AM CDT WED JUL 22 2015 MAY SEE A BRIEF PERIOD OF MVFR VSBYS IN SHALLOW GROUND FOG...ESPECIALLY ALONG THE ILLINOIS RIVER VALLEY WHICH WOULD AFFECT KPIA...BUT THAT APPEARS TO BE TOO LOW A PROBABILITY TO MENTION IN THE TAF THIS MORNING. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH THIS FORECAST PERIOD. HIGH PRESSURE WILL SLOWLY MOVE AWAY FROM OUR AREA TODAY BRINGING ANOTHER DAY WITH SCATTERED CLOUD COVER AND LIGHT WINDS. LOOK FOR THE SURFACE WINDS TO BE LIGHT EAST TO SOUTHEAST TODAY WITH SPEEDS OF 10 KTS OR LESS...AND THEN LIGHT AND VARIABLE WINDS TONIGHT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARNES SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
603 AM CDT WED JUL 22 2015 .SHORT TERM...(TODAY) ISSUED AT 328 AM CDT WED JUL 22 2015 HIGH PRESSURE CENTERED OVER THE MIDWEST EARLY THIS MORNING WILL DOMINATE THE WEATHER OVER MOST OF THE FORECAST AREA THRU THE DAY. HAVE HAD SOME PATCHY FOG DEVELOP OVER PARTS OF THE AREA EARLY THIS MORNING WITH THE HRRR SUGGESTING PARTS OF THE IL RIVER VALLEY AND FROM CMI TO JUST SOUTH OF SPI WILL SEE SOME RESTRICTED VISIBILITIES AT TIMES EARLY THIS MORNING. FORECAST SOUNDINGS AND TIME HEIGHT CROSS SECTIONS INDICATE AN INCREASE IN HIGH LEVEL CLOUD COVER LATER THIS MORNING INTO THE AFTERNOON HOURS AS SHORTWAVE ENERGY TRACKS WELL SOUTH OF THE REGION TODAY. RAP SOUNDINGS INDICATE WE SHOULD MIX DOWN FROM AROUND 800 MB OR APPROX 6000 FEET...WHICH WOULD BRING US AFTERNOON HIGHS IN THE 80 TO 84 DEGREE RANGE. CLOUD COVER SHOULD THICKEN UP EVEN MORE OVER FAR SOUTHEAST IL LATE THIS AFTERNOON AS ADDITIONAL SHORTWAVE ENERGY AND 850-700 MB MOISTURE CONVERGENCE APPROACHES THE I-70 CORRIDOR TOWARDS 00Z. .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 328 AM CDT WED JUL 22 2015 MODELS HAVE SHIFTED CONSIDERABLY WITH THE HANDLING OF THE EXTENDED SUN-WED. IN THE MEANTIME, HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THURSDAY, WITH THE WARMING TREND CONTINUING THROUGH THE END OF THE WEEK AND INTO THE WEEKEND. BROAD UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY. FOR NOW, THE FORECAST IS DRY, BUT THE NAM CONTINUING TO TREND THE TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS WILL REMAIN IN THE FORECAST FOR THU. AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE AXIS DRIFTING OVER THE MIDWEST, TEMPS WARM INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION. HOWEVER, MODELS HIGH TEMPS WILL BE COOLED CONSIDERABLY SHOULD THE PRECIP THAT IS CURRENTLY SHOWING UP IN THE SAT NIGHT-TUES TIME FRAME MATERIALIZES. PREV DRY RUNS UNDER THE EXPANSIVE RIDGE WITH WEAK FLOW ARE LOSING THE DRY FORECAST TO A SERIES OF SMALL WAVES AND WHAT LOOKS LIKE A STALLED BOUNDARY AT THE SFC ALONG THE OHIO RIVER VALLEY SIMILAR TO THE SAME PATTERN REPEATED THROUGH THIS SUMMER. WITH A LACK OF CONTINUITY OR CONSENSUS, SLIGHTS AND LOW CHANCE POPS THROUGH THE END WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 600 AM CDT WED JUL 22 2015 MAY SEE A BRIEF PERIOD OF MVFR VSBYS IN SHALLOW GROUND FOG...ESPECIALLY ALONG THE ILLINOIS RIVER VALLEY WHICH WOULD AFFECT KPIA...BUT THAT APPEARS TO BE TOO LOW A PROBABILITY TO MENTION IN THE TAF THIS MORNING. OTHERWISE...VFR CONDITIONS ARE EXPECTED THROUGH THIS FORECAST PERIOD. HIGH PRESSURE WILL SLOWLY MOVE AWAY FROM OUR AREA TODAY BRINGING ANOTHER DAY WITH SCATTERED CLOUD COVER AND LIGHT WINDS. LOOK FOR THE SURFACE WINDS TO BE LIGHT EAST TO SOUTHEAST TODAY WITH SPEEDS OF 10 KTS OR LESS...AND THEN LIGHT AND VARIABLE WINDS TONIGHT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SMITH LONG TERM...HJS AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
649 AM CDT WED JUL 22 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT WED JUL 22 2015 FOCUS WILL BE ON THE CHANCE FOR RAIN TODAY AND TONIGHT. MOST NOTABLE THING WILL BE THE FACT THESE CHANCES HAVE DIMINISHED ACROSS THE FORECAST AREA. TEMPERATURES WILL BE BELOW NORMAL FOR HIGHS TODAY...BUT LOWS WILL BE ABOVE NORMAL LATER TONIGHT. AT THE SURFACE...AN AREA OF HIGH PRESSURE IS CENTER EAST OF THE FORECAST AREA...WHICH SHOULD KEEP US IN A SOUTHERLY WIND PATTERN THROUGH THE SHORT TERM WITH SPEEDS GENERALLY AROUND/UNDER 10 MPH. WE LACK A TRIGGERING MECHANISM TODAY...AND CAPE VALUES ARE NIL TO VERY LOW FOR MOST OF THE DAY. MUCAPE VALUES START TO PICK UP THIS AFTERNOON...ESPECIALLY ACROSS OUR SOUTHWEST AND SOUTH...WITH VALUES MOSTLY AROUND THE 500-1500 J/KG RANGE. THE NAM SUGGEST VALUES COULD BE AS HIGH AS 2000 J/KG BUT THIS IS THE MORE AGGRESSIVE SOLUTION. 0- 6 KM BULK SHEAR VALUES RANGE BETWEEN 20-35 KNOTS. 0-1 KM HELICITY VALUES VARY GREATLY BETWEEN THE NAM...GFS...AND EUROPEAN. OVERALL...THESE VALUES ARE VERY LOW UNTIL TONIGHT WHEN VALUES RANGE BETWEEN 80-150 M^2/S^2 OVERNIGHT. WITHOUT A TRUE TRIGGERING MECHANISM TODAY...WE ARE RELYING SOLELY ON ISENTROPIC LIFT WHICH IS NOT BACK ACROSS KANSAS...AND THIS IS REFLECTED IN THE FORECAST WITH HIGHER POPS ACROSS THE SOUTH. WE ARE REALLY GOING TO STRUGGLE TO GET RAINFALL TODAY. MANY OF THE SIMULATED REFLECTIVITY MODELS SUGGEST MOSTLY DRY CONDITIONS OVER THE SHORT TERM. THE HRRR IS REALLY THE MOST OPTIMISTIC FOR RAINFALL CHANCES TODAY. NMM...ARW...AND THE NAM4KM ALL HAVE MOSTLY DRY CONDITIONS. I HAVE DECREASED POPS FROM THE PREVIOUS FORECAST TO REFLECT THIS TREND. HIGHER CHANCES WILL BE TONIGHT...ESPECIALLY FOR AREAS GENERALLY SOUTH OF INTERSTATE 80. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 338 AM CDT WED JUL 22 2015 GUIDANCE SUGGESTS GENERALLY WEAK QUASI-ZONAL UPPER TROPOSPHERIC FLOW WILL EXIST OVER THE CENTRAL PLAINS TO START THE LONG-TERM FORECAST PERIOD AT 12Z THURSDAY. GUIDANCE SUGGESTS THIS WEAK UPPER TROPOSPHERIC FLOW WILL CONTINUE OVER OUR AREA THROUGH NEXT SUNDAY AS UPPER TROPOSPHERIC RIDING STRENGTHENS ACROSS THE AREA. SOME BREAKDOWN IN THE RIDGE IS THEN EXPECTED EARLY NEXT WEEK AS AN UPPER TROPOSPHERIC SHORT WAVE MOVES FROM THE NORTHWESTERN CONUS INTO THE NORTH CENTRAL CONUS. IT APPEARS OMEGA WILL REMAIN ON THE WEAK SIDE ACROSS OUR AREA DURING MUCH OF THE LONG-TERM FORECAST PERIOD...WHICH INCLUDES EARLY NEXT WEEK WITH THE AFOREMENTIONED UPPER TROPOSPHERIC SHORT WAVE REMAINING NORTH OF OUR AREA. THAT SAID...VARIOUS SETS OF GUIDANCE CONTINUE TO SUGGEST AN UPPER TROPOSPHERIC PERTURBATION OR TWO COULD CLEAR THE REGION LATE THIS WEEK INTO EARLY NEXT WEEK...AND THERE REMAIN SIGNALS THAT HIGH PLAINS CONVECTION COULD SUSTAIN ITSELF LONG ENOUGH TO IMPACT OUR AREA DURING THE EVENING AND OVERNIGHT HOURS BETWEEN THURSDAY AND TUESDAY. GIVEN ALL THIS...WENT AHEAD WITH GENERALLY 20- 40% POPS ACROSS VARIOUS PORTIONS OF THE CWA BETWEEN THURSDAY EVENING AND NEXT TUESDAY. AS MENTIONED YESTERDAY...LOW VALUES DEEP-LAYER SHEAR AND HIGH VALUES OF POTENTIAL ENERGY SHOULD PRESENT ITSELF ACROSS MUCH OF THE AREA DURING THE LONG-TERM FORECAST PERIOD. ALTHOUGH THERE REMAINS CONSIDERABLE UNCERTAINTY WITH RESPECT TO THE TIMING AND PLACEMENT OF CONVECTIVE INITIATION FROM DAY TO DAY...GIVEN THE FACT THAT GUIDANCE SUGGESTS POTENTIAL ENERGY VALUES OF ~2000J/KG WILL BE REALIZED ACROSS MUCH OF THE AREA BOTH THURSDAY AND FRIDAY...FELT IT PRUDENT TO GO WITH A MENTION OF STRONG THUNDERSTORM ACTIVITY IN THE HWO FOR THURSDAY EVENING AS WELL AS FRIDAY AFTERNOON AND EVENING. MUCH WARMER WEATHER IS STILL EXPECTED DURING THE LONG-TERM FORECAST PERIOD...WITH HIGHS GENERALLY IN THE UPPER 80S AND 90S ON MOST DAYS...AND PERHAPS APPROACHING 100 DEGREES FOR SOME LOCATIONS ON FRIDAY. GUIDANCE ALSO SUGGESTS BOUNDARY-LAYER DEW POINTS IN THE UPPER 60S TO MID 70S WILL HELP PROMOTE HEAT INDEX READINGS NEAR 100 DEGREES FOR PORTIONS OF THE OUTLOOK AREA BOTH THURSDAY AND SATURDAY...AND AROUND 105 DEGREES ON FRIDAY. WILL GO AHEAD AND CONTINUE WITH THE HEAT INDEX WORDING IN THE HWO AS A RESULT. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 636 AM CDT WED JUL 22 2015 VFR CONDITIONS ARE EXPECTED AT THE TERMINAL SITES THROUGH A MAJORITY OF THE VALID TAF PERIOD. THERE ARE REALLY TWO CONCERNS THIS PERIOD. ONE IS THE CHANCE FOR THUNDERSTORMS LATER TODAY/TONIGHT...AND THE OTHER IS FOR THE POSSIBILITY OF FOG DEVELOPMENT TOMORROW MORNING. THUNDERSTORM CHANCES ARE SMALL TODAY BUT LOOK TO BE BEST LATE THIS AFTERNOON/EARLY EVENING AROUND 00Z. THERE COULD BE SOME LIGHT RAIN AROUND THIS MORNING AND EARLY AFTERNOON...BUT THE LACK INSTABILITY SHOULD HOLD OFF THUNDERSTORMS UNTIL LATER THIS AFTERNOON. ALSO...LOOK FOR AMENDMENTS IN THE TAF LATER TODAY ONCE TIMING AND COVERAGE IS BETTER UNDERSTOOD. WE COULD HAVE A CHANGE IN FLIGHT CATEGORIES IF THUNDERSTORMS LOOK MORE LIKELY. OTHERWISE...WE DO NOT HAVE CONDITIONS CHANGING UNTIL AROUND 09Z TOMORROW WHEN THE CHANCES FOR FOG INCREASE. WE COULD GO TO AT LEAST MVFR AT THIS TIME. TOMORROW NIGHT WIND SPEEDS WILL GO LIGHT AND VARIABLE...AND CONDITIONS FOR FOG DEVELOPMENT INCREASE UNDER A MOIST ATMOSPHERE. THE INVERSION TOMORROW IS NOT TOO DEEP/STRONG...SO THE WINDOW OF OPPORTUNITY FOR FOG DEVELOPMENT IS AROUND 4 TO 5 HOURS AT MOST BEFORE WE START MIXING OUT. IT WILL BE SOMETHING TO LOOK TOMORROW MORNING. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...GUERRERO LONG TERM...BRYANT AVIATION...GUERRERO
AREA FORECAST DISCUSSION
NWS BISMARCK ND
956 AM CDT WED JUL 22 2015 .UPDATE... ISSUED AT 956 AM CDT WED JUL 22 2015 SKY COVER AND POPS WERE ADJUSTED TO FIT LATEST OBSERVATIONS AND RADAR IMAGERY. TWO EMBEDDED S/WV IMPULSES MOVING THROUGH THE MID LEVEL RIDGE TRIGGERING CONVECTION THIS MORNING ACROSS NORTHEASTERN MONTANA AND NORTHEASTERN SOUTH DAKOTA. A FEW OF THESE STORMS MAY MIGRATE OR DEVELOP INTO THE SOUTHERN JAMES RIVER VALLEY...ALTHOUGH BETTER CHANCE THAT CONVECTION IN NORTHEASTERN MONTANA WILL CROSS THE BORDER INTO NORTHWEST NORTH DAKOTA OVER THE NEXT FEW HOURS. NOTHING SEVERE EXPECTED. HIGH RES MODELS DEVELOP ISOLATED STORMS THIS AFTERNOON WEST AND OVER THE JAMES RIVER VALLEY...SO WILL MAINTAIN/ADD A LOW POP FOR THESE AREAS. OTHER FORECAST ELEMENTS ON TRACK FOR THE MID/LATE MORNING UPDATE. UPDATE ISSUED AT 650 AM CDT WED JUL 22 2015 FORECAST GENERALLY ON TRACK. MADE A FEW MINOR ADJUSTMENTS TO SKY AND BLENDED OTHER ELEMENTS TO LATEST OBSERVATIONS. CONTINUED TO CARRY LOW POPS ACROSS SOUTHEAST AND NORTHWEST. RADAR SHOWED A FEW THUNDERSTORMS OVER NORTHEAST MONTANA SLOWLY APPROACHING NORTHWEST ND. HIGH RES MODELS CONTINUE TO SHOW A FEW SHOWERS POSSIBLE ACROSS THE FAR SOUTHEAST AS WELL...THOUGH CURRENT RADAR HAS ANY ACTIVITY OUTSIDE OUR CWA AT THE MOMENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 317 AM CDT WED JUL 22 2015 THUNDERSTORMS WILL BE THE FOCUS FOR THE SHORT TERM. A WARM FRONT WILL CONTINUE TO LIFT NORTHEAST ACROSS THE STATE THIS MORNING. ISOLATED THUNDERSTORMS MAY DEVELOP ALONG THE FRONT THROUGH THE MORNING HOURS ACROSS THE JAMES VALLEY. THE LATEST (7UTC) HRRR IS A LITTLE TOO ROBUST WITH THUNDERSTORM DEVELOPMENT ACROSS THE VALLEY AS IT HAS THUNDERSTORMS ACROSS PORTIONS OF LOGAN...MCINTOSH...LAMOURE AND DICKEY COUNTIES...YET CURRENT RADAR TRENDS INDICATE ONLY ISOLATED THUNDERSTORMS WELL TO THE EAST. A COLD FRONT AND SURFACE TROUGH WILL SLOWLY ENTER WESTERN NORTH DAKOTA THIS EVENING/OVERNIGHT. SHOWERS AND THUNDERSTORMS ARE SHOWN DEVELOPING ALONG THE FRONT IN THE HRRR/RAP/WRF/NAM. SCATTERED STORMS ARE POSSIBLE THROUGH THE NIGHT ACROSS WESTERN NORTH DAKOTA. TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGREES WARMER THAN YESTERDAY AS WAA CONTINUES AND WE BECOME FULLY ENTRENCHED IN THE WARM SECTOR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 317 AM CDT WED JUL 22 2015 MAIN FORECAST ISSUE CONTINUES TO BE THUNDERSTORM TIMING...COVERAGE AND POSSIBILITY OF SEVERE ON THURSDAY. MODELS ARE GENERALLY ON THE SAME TRACK...ALTHOUGH GFS HAS A SLIGHTLY FARTHER NORTHWARD PLACEMENT OF QPF COMPARED TO NAM/ECMWF/SREF. GFS APPEARS TO HAVE A SLIGHTLY WEAKER VORT MAX MOVING ACROSS SOUTHWESTERN AND CENTRAL ND IN WEST/SOUTHWEST FLOW. FOR THE FORECAST...FOLLOWED THE NAM/ECMWF SOLUTIONS WITH A MORE SOUTHWARD DEVELOPMENT OF CONVECTION WHICH IS ALSO MORE IN LINE WITH THE SPC DAY 2 CONVECTIVE OUTLOOK SHOWING SLIGHT RISK OF SEVERE THUNDERSTORM AREA OVER ALL BUT FAR WESTERN ND ON THURSDAY. ALL MODELS FORECAST AMPLE INSTABILITY WITH UPWARDS OF 2000-3000 J/KG OF SURFACE BASED CAPE ACROSS CENTRAL AND EASTERN ND BY 18Z WITH SURFACE LOW AND ASSOCIATED COLD FRONT INTO WESTERN ND...WHICH WILL SERVE AS A FOCUS FOR CONVECTIVE DEVELOPMENT. 0-6KM SHEAR STARTS OUT AROUND 20-25KTS AT 18Z THU PER GFS/NAM WITH STRONGER VALUES DISPLACED WEST OF BEST CAPE...EVENTUALLY INCREASING TO 30-35KTS BY THURSDAY EVENING ACROSS THE STATE. STORMS SHOULD BE EXITING EASTERN CWA BETWEEN 06Z AND 12Z FRIDAY. QUASI-ZONAL FLOW DEVELOPS THROUGH EARLY WEEKEND BEFORE A DEEPER LONGWAVE TROUGH MOVES THROUGH THE PAC NW BRINGING ANOTHER LOW PRESSURE SYSTEM THROUGH MONTANA...BRUSHING WESTERN ND AND INTO SOUTHERN CANADA. OVERALL WILL CONTINUE TO SEE PERIODIC...GENERALLY LOW CHANCES OF PRECIP THROUGH REMAINDER OF EXTENDED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 650 AM CDT WED JUL 22 2015 VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...AJ LONG TERM...JNS AVIATION...JNS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
650 AM CDT WED JUL 22 2015 .UPDATE... ISSUED AT 650 AM CDT WED JUL 22 2015 FORECAST GENERALLY ON TRACK. MADE A FEW MINOR ADJUSTMENTS TO SKY AND BLENDED OTHER ELEMENTS TO LATEST OBSERVATIONS. CONTINUED TO CARRY LOW POPS ACROSS SOUTHEAST AND NORTHWEST. RADAR SHOWED A FEW THUNDERSTORMS OVER NORTHEAST MONTANA SLOWLY APPROACHING NORTHWEST ND. HIGH RES MODELS CONTINUE TO SHOW A FEW SHOWERS POSSIBLE ACROSS THE FAR SOUTHEAST AS WELL...THOUGH CURRENT RADAR HAS ANY ACTIVITY OUTSIDE OUR CWA AT THE MOMENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 317 AM CDT WED JUL 22 2015 THUNDERSTORMS WILL BE THE FOCUS FOR THE SHORT TERM. A WARM FRONT WILL CONTINUE TO LIFT NORTHEAST ACROSS THE STATE THIS MORNING. ISOLATED THUNDERSTORMS MAY DEVELOP ALONG THE FRONT THROUGH THE MORNING HOURS ACROSS THE JAMES VALLEY. THE LATEST (7UTC) HRRR IS A LITTLE TOO ROBUST WITH THUNDERSTORM DEVELOPMENT ACROSS THE VALLEY AS IT HAS THUNDERSTORMS ACROSS PORTIONS OF LOGAN...MCINTOSH...LAMOURE AND DICKEY COUNTIES...YET CURRENT RADAR TRENDS INDICATE ONLY ISOLATED THUNDERSTORMS WELL TO THE EAST. A COLD FRONT AND SURFACE TROUGH WILL SLOWLY ENTER WESTERN NORTH DAKOTA THIS EVENING/OVERNIGHT. SHOWERS AND THUNDERSTORMS ARE SHOWN DEVELOPING ALONG THE FRONT IN THE HRRR/RAP/WRF/NAM. SCATTERED STORMS ARE POSSIBLE THROUGH THE NIGHT ACROSS WESTERN NORTH DAKOTA. TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGREES WARMER THAN YESTERDAY AS WAA CONTINUES AND WE BECOME FULLY ENTRENCHED IN THE WARM SECTOR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 317 AM CDT WED JUL 22 2015 MAIN FORECAST ISSUE CONTINUES TO BE THUNDERSTORM TIMING...COVERAGE AND POSSIBILITY OF SEVERE ON THURSDAY. MODELS ARE GENERALLY ON THE SAME TRACK...ALTHOUGH GFS HAS A SLIGHTLY FARTHER NORTHWARD PLACEMENT OF QPF COMPARED TO NAM/ECMWF/SREF. GFS APPEARS TO HAVE A SLIGHTLY WEAKER VORT MAX MOVING ACROSS SOUTHWESTERN AND CENTRAL ND IN WEST/SOUTHWEST FLOW. FOR THE FORECAST...FOLLOWED THE NAM/ECMWF SOLUTIONS WITH A MORE SOUTHWARD DEVELOPMENT OF CONVECTION WHICH IS ALSO MORE IN LINE WITH THE SPC DAY 2 CONVECTIVE OUTLOOK SHOWING SLIGHT RISK OF SEVERE THUNDERSTORM AREA OVER ALL BUT FAR WESTERN ND ON THURSDAY. ALL MODELS FORECAST AMPLE INSTABILITY WITH UPWARDS OF 2000-3000 J/KG OF SURFACE BASED CAPE ACROSS CENTRAL AND EASTERN ND BY 18Z WITH SURFACE LOW AND ASSOCIATED COLD FRONT INTO WESTERN ND...WHICH WILL SERVE AS A FOCUS FOR CONVECTIVE DEVELOPMENT. 0-6KM SHEAR STARTS OUT AROUND 20-25KTS AT 18Z THU PER GFS/NAM WITH STRONGER VALUES DISPLACED WEST OF BEST CAPE...EVENTUALLY INCREASING TO 30-35KTS BY THURSDAY EVENING ACROSS THE STATE. STORMS SHOULD BE EXITING EASTERN CWA BETWEEN 06Z AND 12Z FRIDAY. QUASI-ZONAL FLOW DEVELOPS THROUGH EARLY WEEKEND BEFORE A DEEPER LONGWAVE TROUGH MOVES THROUGH THE PAC NW BRINGING ANOTHER LOW PRESSURE SYSTEM THROUGH MONTANA...BRUSHING WESTERN ND AND INTO SOUTHERN CANADA. OVERALL WILL CONTINUE TO SEE PERIODIC...GENERALLY LOW CHANCES OF PRECIP THROUGH REMAINDER OF EXTENDED. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 650 AM CDT WED JUL 22 2015 VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JNS SHORT TERM...AJ LONG TERM...JNS AVIATION...JNS
AREA FORECAST DISCUSSION
NWS TULSA OK
938 AM CDT WED JUL 22 2015 ...UPDATE... .DISCUSSION... SCATTERED THUNDERSTORMS PERSIST THIS MORNING GENERALLY ALONG THE INTERSTATE 40 CORRIDOR IN A REGION OF MID LEVEL WARM ADVECTION. THESE WILL CONTINUE TO PUSH OFF TO THE EAST THROUGH THE REST OF THE MORNING AND INTO EARLY AFTERNOON. ANOTHER BATCH OF STORMS REMAINS ACROSS NORTHWEST OKLAHOMA...ALSO MOVING TO THE EAST. IT HAS EXHIBITED SOME WEAKENING OVER THE PAST HOUR OR SO...ALTHOUGH NOT AS DRASTIC AS THE HRRR WOULD SUGGEST. WITH INSTABILITY BEING FAIRLY LOW ACROSS NORTH CENTRAL AND NORTHEAST OKLAHOMA...WOULD EXPECT THESE TO WEAKEN FURTHER AS THEY NEAR THE FORECAST AREA. HAVE MADE A FEW TWEAKS TO THE POP AND QPF FORECAST TO FOCUS HIGHER POPS AND FORECAST RAINFALL ALONG INTERSTATE 40...AND LOWER THEM SOME IN FAR NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS. UPDATES ALREADY OUT. && .PREV DISCUSSION... /ISSUED 634 AM CDT WED JUL 22 2015/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS MORNING MAINLY OVER SOUTHEAST OK AND WESTERN AR. A FEW AREAS OF IFR AND LIFR CIGS WILL BE POSSIBLE...WITH IMPROVEMENT EXPECTED THIS AFTERNOON. SCATTERED THUNDERSTORM REDEVELOPMENT WILL BE POSSIBLE LATER THIS AFTERNOON...WITH ANOTHER THUNDERSTORM COMPLEX POSSIBLY IMPACTING FAR NORTHEAST OK/NORTHWEST ARKANSAS LATER TONIGHT. PREV DISCUSSION... /ISSUED 356 AM CDT WED JUL 22 2015/ DISCUSSION... ONGOING AREA OF SHOWERS AND THUNDERSTORMS AFFECTING MAINLY AREAS SOUTH OF I-44 AND NORTH OF I-40 WITH 2-3 INCH RAINFALL AMOUNTS FAIRLY COMMON AS SOME TRAINING OF CELLS HAS BEEN NOTED. OVERALL TREND HAS BEEN FOR THIS AREA TO BE PROGRESSIVE AND SHOULD CONTINUE TO PUSH SLOWLY EAST THROUGH EARLY THIS MORNING. STORMS CONTINUE TO BE EFFICIENT RAIN MAKERS AND A FEW AMOUNTS OF 4-5 INCHES REMAIN POSSIBLE WITH LOCAL FLOODING ISSUES PROBABLE. ADDITIONAL SHOWERS AND STORMS HAVE BEEN ON THE INCREASE ACROSS SW KANSAS OVER THE PAST COUPLE OF HOURS AND WHILE IT IS POSSIBLE THESE COULD MAKE A RUN AT NE OKLAHOMA BY THIS AFTERNOON...WOULD EXPECT DECREASING TREND HERE AS WELL WITH WANING LOW LEVEL JET SUPPORT THROUGH THE MORNING. FRONTAL BOUNDARY WILL BEGIN LIFTING NORTH TODAY AND WILL NEED TO BE WATCHED FOR ADDITIONAL THUNDERSTORM DEVELOPMENT THIS AFTERNOON. ANY STORMS DURING THE AFTERNOON WOULD BE CAPABLE OF BECOMING STRONG WITH GUSTY WINDS POSSIBLE. MORE WIDESPREAD STORMS AGAIN TONIGHT NORTH OF THE BOUNDARY...MOSTLY ACROSS KS/MO. HOWEVER SOME OF THE LATEST DATA SUGGESTS THIS COULD BRUSH FAR NE OKLAHOMA AND NW ARKANSAS LATER TONIGHT. AFTER TONIGHT THE HEAT WILL BE ON ONCE AGAIN AS MID LEVEL HEIGHTS RISE WITH STRENGTHENING RIDGE. DEW POINTS WILL REMAIN HIGH AND HEAT INDEX VALUES SHOULD EASILY EXCEED 105 IN SOME AREAS BY THURSDAY AND MUCH OF THE AREA BY FRIDAY AND BEYOND. HOT WEATHER WILL PERSIST INTO NEXT WEEK WITH SOMEWHAT DEEPER LOW LEVEL MOISTURE PERHAPS WORKING INTO EASTERN AREAS BY TUESDAY RESULTING IN SLIM CHANCE OF SHOWERS AND THUNDERSTORMS IN TERRAIN AREAS. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...22
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
753 AM EDT WED JUL 22 2015 .SYNOPSIS... HIGH PRESSURE BUILDING INTO THE NORTHEAST WILL USHER IN COMFORTABLE TEMPERATURES AND LOW HUMIDITY RIGHT THROUGH SATURDAY. THE NEXT CHANCE OF SHOWERS WILL ARRIVE LATE SATURDAY NIGHT OR SUNDAY AS A WEAK COLD FRONTAL SYSTEM DRIFTS SOUTHEAST FROM THE GREAT LAKES REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE COLD FRONT THAT BROUGHT A BROKEN LINE OF BRIEF SHOWERS AND THUNDERSTORMS TO THE REGION LATE TUESDAY AFTERNOON AND EVENING...NOW STRETCHES FROM LONG ISLAND TO CENTRAL VA. LLVL RIDGING AND GRADUALLY RISING HEIGHTS IN THE WAKE OF THIS FRONT WILL LEAD TO CLEAR TO PTLY CLOUDY SKIES FOR PRACTICALLY ALL OF THE CWA THIS MORNING...COMPLETE WITH REFRESHINGLY COOLER AND LESS HUMID AIR. THE LONE...SMALL FRUIT FLY IN THE OINTMENT COMES IN THE FORM OF A WELL-DEFINED/BUT RATHER COMPACT MID-LEVEL THERMAL TROUGH AND RIGHT ENTRANCE REGION OF A 90 KT 300 MB JETLET...THAT WAS FOCUSED OVER EASTERN LAKE ERIE AT 08Z. THIS SMALL POCKET OF INSTABILITY AND UVVEL WILL SLIDE EAST AND WEAKEN GRADUALLY TODAY. SOME BKN-OVC HIGH-BASED STRATO CU AND ALTO CU WILL BE ACCOMPANIED BY A FEW SPRINKLES OR EVEN A BRIEF SHOWERS ACROSS OUR FAR NW CWA. LATEST SEVERAL RUNS OF THE HRRR INDICATE THIS SPOTTY AND VERY MINOR QPF POTENTIAL. THE AREA OF HIGH PRESSURE AND MUCH DRIER AIR MASS WILL SET UP RESIDENCE FOR SEVERAL DAYS AS THE PATTERN OVER NOAM SHIFTS FROM THE UNPLEASANTLY HUMID/WET WITH MEAN UPPER RIDGE LOCATED OVER THE UPPER MIDWEST. MIN TEMPS EARLY THIS WEDNESDAY WILL VARY FROM THE LOWER 50S NORTH...TO THE LOWER 60S THROUGHOUT THE LOWER SUSQ VALLEY. HIGH PRESSURE AND ANOMALOUSLY LOW PW WILL SPELL A GEM OF A DAY TODAY...AS A DEEP UPPER LOW OVER SERN CANADA AND NWRLY UPPER FLOW ACROSS PENN DELIVERS A MORE REFRESHING CANADIAN AIR TO THE REGION...GIVING US A BREAK FROM THE RECENT 8 WEEKS OF FREQUENTLY HUMID AND WET WEATHER. A NW BREEZE...FRESHENING TO 8-12 KTS /WITH A FEW GUSTS INTO THE MID TEENS/ WILL COMBINE WITH LOW DEWPOINTS...AND MAX TEMPS RANGING FROM THE MID 70S NORTH TO THE LOWER 80S IN THE SOUTHEAST /JUST A FEW DEG F BELOW NORMAL/. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... HIGH PRESSURE WILL BE MOVING INTO WRN PENN TONIGHT. THIS WEATHER FEATURE WILL BRING CLEAR SKIES /AND JUST A LIGHT NW BREEZE EARLY TONIGHT/. AN EVEN COOLER NIGHT IS ON TAP...WITH MINS EARLY THURSDAY RANGING FROM THE U40S TO L50S ACROSS THE NRN MTNS AND COLD SPOTS THROUGHOUT THE LAUREL HIGHLANDS...TO THE U50S IN THE LOWER SUSQ VALLEY. THE COOL AIR TEMPS AND WARM WATER TEMPS MAY YIELD SOME PATCHY 2SM RIVER VALLEY FOG UP NORTH BETWEEN 08-12Z THUR. ANOTHER SPLENDID MID SUMMER DAY FOR THURSDAY...UNDER SFC HIGH PRESSURE AND NW FLOW ALOFT. AFTERNOON HIGH TEMPS WILL BE JUST 1-3 DEG F SHY OF NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... 1016-1018 MB SFC HIGH PRESSURE LOCATED NEAR THE PA/OHIO BORDER TO START THE PERIOD...WILL DRIFT EAST ACROSS THE FCST AREA FRI NIGHT AND SATURDAY. THIS DOMINANT WEATHER FEATURE WILL PROVIDE FAIR WEATHER WITH MAINLY LIGHT WIND...CONTINUED COMFORTABLY LOW DAYTIME HUMIDITY...AND MAX TEMPS NEAR TO SLIGHTLY ABOVE NORMAL. THE NEXT CHANCE OF A SHOWER OR THUNDERSTORM WILL BE MAINLY AFTER 00Z SUNDAY...AS LOW-MID LEVEL WARM ADVECTION AND INCREASING SHEAR DEVELOPS. THE BULK OF THIS PRECIP POTENTIAL WILL BE MAINLY SUNDAY AND MONDAY. WENT DRY FOR TUE...AS THE NEXT HIGH PRESSURE SYSTEM BUILDS SE. ENJOY THE NICE WEATHER. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... COOL POOL ALOFT CONTINUING TO GENERATE A MID DECK AS IT SLIPS EASTWARD...WITH BRIEF VFR CIG LIKELY AT KIPT RIGHT AROUND 12Z. OTHERWISE...FEW CLOUDS TODAY AS WE ENTER A PROLONGED PERIOD OF EXCELLENT FLYING CONDITIONS AND DRY WEATHER THAT WILL EXTEND INTO SAT. BIGGEST FORECAST CONCERN TODAY WILL BE NW WINDS INCREASING TO 10 MPH WITH GUSTS TO 20 MPH FROM LATE MORNING THROUGH THE AFTERNOON. WINDS SUBSIDE AROUND SUNSET. OUTLOOK... THU-SAT...MAINLY VFR. LOCAL A.M. FOG POSS NORTH. SAT NIGHT-SUN...CHC SHRA/TSTM. MVFR CIGS POSS NW. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LAMBERT NEAR TERM...LAMBERT SHORT TERM...LAMBERT LONG TERM...LAMBERT/MARTIN AVIATION...RXR
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
918 AM PDT WED JUL 22 2015 .SYNOPSIS...COOLER THAN NORMAL TEMPERATURES CAN BE EXPECTED INLAND WITH NEAR NORMAL READINGS AT THE COAST FOR THE REST OF THE WEEK. A RIDGE OF HIGH PRESSURE IS ANTICIPATED TO BUILD OVER THE FORECAST AREA NEXT WEEK PROMOTING WARMING TEMPERATURES AND CONTINUED DRY WEATHER. && .DISCUSSION...AS OF 09:09 AM PDT WEDNESDAY...A DEEP MARINE LAYER OF AROUND 2000 FEET IN DEPTH THIS MORNING HAS KEPT WIDESPREAD STRATUS OVER A GOOD PORTION OF THE COASTAL AND VALLEY AREAS. WHILE MOST INLAND AREAS SHOULD SEE THE LOW CLOUDS BURN-OFF THROUGH LATE MORNING...MANY COASTAL AREAS MAY REMAIN UNDER OVERCAST SKIES THROUGH THE DAY. NO UPDATED NEEDED TO THE FORECAST AT THIS TIME. && .PREV DISCUSSION...AS OF 3:00 AM PDT WEDNESDAY...AS FORECAST COOLER AND DRIER AIR HAS SETTLED ACROSS OUR REGION. THANKS TO A MODERATE ONSHORE FLOW AT THE SURFACE PLUS A MARINE LAYER AROUND 1800 FEET SHOULD SEE WIDESPREAD COASTAL CLOUDS TODAY ALONG WITH MANY VALLEY SPOTS. IN OTHER WORDS...A TYPICAL JULY DAY FOR THE SAN FRANCISCO AND MONTEREY BAY REGION. THE ONLY DIFFERENCE WILL BE THE LACK OF STRONG INLAND HEAT DUE TO A LONGWAVE TROF STRETCHING FROM CALIFORNIA INTO WESTERN CANADA. HIGHS WILL BE GENERALLY IN THE 60S TO LOWER 70S AT THE COAST WITH UPPER 70S TO AROUND 90 FOR MOST INLAND SPOTS. SYNOPTICALLY LITTLE WILL CHANGE THROUGH AT LEAST FRIDAY WITH THE TROF OVERHEAD AND PERSISTENT ONSHORE FLOW AT THE SURFACE. MODELS CONTINUE TO SHOW THE POSSIBILITY OF COASTAL DRIZZLE WHICH LINES UP WELL WITH THE PATTERN. HIGHS WILL REMAIN COOLER THAN NORMAL INLAND WHILE COASTAL SPOTS WILL BE NEAR NORMAL. BY THE WEEKEND A RIDGE OF HIGH PRESSURE WILL START TO BUILD BACK TO OUR AREA FROM THE SOUTHEAST. BOTH 500 MB HEIGHTS PLUS 850 MB TEMPS WILL RISE HELPING TO PUSH INLAND HIGHS BACK CLOSER TO NORMAL AT FIRST AND THEN ABOVE NORMAL BY NEXT WORK WEEK. LONGER RANGE OUTLOOK SHOWS ABOVE NORMAL READINGS FOR ALL NEXT WEEK ALONG WITH DRY CONDITIONS AS 500 MB HEIGHTS EXCEED 590 DM AND 850 MB TEMPS APPROACH 25C. && .AVIATION...AS OF 04:50 AM PDT WEDNESDAY... MARINE LAYER STRUGGLING TO GAIN A FOOTHOLD IN THE BAY AREA THIS MORNING AFTER MAKING AN INITIAL PUSH EARLIER IN THE NIGHT. MAJORITY OF SHORT TERM GUIDANCE STRUGGLING NOT KEEPING UP WITH SATELLITE TRENDS... SO HAVE LEANED CLOSER TOWARDS RUC SOLUTION OF BRIEF MVFR CIGS POSBL BTWN 14-15Z FOR BAY AREA. ELSEWHERE... FORT ORD PROFILER SHOWING DEPTH OF MARINE LAYER AROUND 1000 FT WITH BASES AT 1000 FT AND TOPS CLOSE TO 2000 FT. FOG PRODUCT SHOWS MONTEREY BAY AND SALINAS VALLEY COMMUNITIES ARE UNDER MVFR CEILINGS. EXPECT A MID TO LATE MORNING CLEARING FOR MONTEREY BAY. VICINITY OF KSFO... LOW TO MODERATE CONFIDENCE REFLECTED BY TEMPO GROUP THIS MORNING. VFR POSBL THRU MORN AT KSFO. ONSHORE GRADIENTS TIGHTEN THIS AFTERNOON. MARINE LAYER RETURNS TONIGHT. KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MONTEREY BAY AREA TERMINALS... CIGS AROUND 1000 FT THIS MORNING THROUGH 18-19Z... WITH MARINE LAYER RETURNING LATER TODAY AROUND 01Z. && .MARINE...AS OF 09:09 AM PDT WEDNESDAY...NORTHWEST WINDS WILL PREVAIL TODAY WITH MODERATE STRENGTH WINDS OVER THE NORTHERN OUTER WATERS AS A TROUGH OF LOW PRESSURE PASSES THROUGH THE FORECAST AREA. WINDS WILL DECREASE BEHIND THE TROUGH AS THE SURFACE PRESSURE GRADIENT WEAKENS...RESULTING IN GENERALLY LIGHT WINDS TOMORROW THROUGH SUNDAY. BY SUNDAY AFTERNOON EXPECT INCREASING NORTHERLY WINDS AS THE SURFACE PRESSURE GRADIENT INCREASES ONCE AGAIN. && .MTR WATCHES/WARNINGS/ADVISORIES... .TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM SCA...SF BAY FROM 2 PM && $$ PUBLIC FORECAST: RGASS AVIATION: DRP MARINE: LARRY VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO FOLLOW US ON FACEBOOK AND TWITTER AT: WWW.FACEBOOK.COM/NWSBAYAREA WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1248 PM CDT WED JUL 22 2015 .UPDATE... ISSUED AT 1039 AM CDT WED JUL 22 2015 ANOTHER MOSTLY SUNNY AND DRY DAY IS UNFOLDING ACROSS CENTRAL ILLINOIS TODAY. AFTERNOON HIGH TEMPERATURES WILL BE A DEGREE OR TWO WARMER THAN YESTERDAY...GENERALLY REACHING THE LOWER TO MIDDLE 80S. CURRENT FORECAST IS ON TRACK AND REQUIRES NO UPDATE THIS MORNING. && .SHORT TERM...(TODAY) ISSUED AT 328 AM CDT WED JUL 22 2015 HIGH PRESSURE CENTERED OVER THE MIDWEST EARLY THIS MORNING WILL DOMINATE THE WEATHER OVER MOST OF THE FORECAST AREA THRU THE DAY. HAVE HAD SOME PATCHY FOG DEVELOP OVER PARTS OF THE AREA EARLY THIS MORNING WITH THE HRRR SUGGESTING PARTS OF THE IL RIVER VALLEY AND FROM CMI TO JUST SOUTH OF SPI WILL SEE SOME RESTRICTED VISIBILITIES AT TIMES EARLY THIS MORNING. FORECAST SOUNDINGS AND TIME HEIGHT CROSS SECTIONS INDICATE AN INCREASE IN HIGH LEVEL CLOUD COVER LATER THIS MORNING INTO THE AFTERNOON HOURS AS SHORTWAVE ENERGY TRACKS WELL SOUTH OF THE REGION TODAY. RAP SOUNDINGS INDICATE WE SHOULD MIX DOWN FROM AROUND 800 MB OR APPROX 6000 FEET...WHICH WOULD BRING US AFTERNOON HIGHS IN THE 80 TO 84 DEGREE RANGE. CLOUD COVER SHOULD THICKEN UP EVEN MORE OVER FAR SOUTHEAST IL LATE THIS AFTERNOON AS ADDITIONAL SHORTWAVE ENERGY AND 850-700 MB MOISTURE CONVERGENCE APPROACHES THE I-70 CORRIDOR TOWARDS 00Z. .LONG TERM...(TONIGHT THROUGH TUESDAY) ISSUED AT 328 AM CDT WED JUL 22 2015 MODELS HAVE SHIFTED CONSIDERABLY WITH THE HANDLING OF THE EXTENDED SUN-WED. IN THE MEANTIME, HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST BELOW NORMAL FOR THURSDAY, WITH THE WARMING TREND CONTINUING THROUGH THE END OF THE WEEK AND INTO THE WEEKEND. BROAD UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY. FOR NOW, THE FORECAST IS DRY, BUT THE NAM CONTINUING TO TREND THE TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS WILL REMAIN IN THE FORECAST FOR THU. AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE AXIS DRIFTING OVER THE MIDWEST, TEMPS WARM INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION. HOWEVER, MODELS HIGH TEMPS WILL BE COOLED CONSIDERABLY SHOULD THE PRECIP THAT IS CURRENTLY SHOWING UP IN THE SAT NIGHT-TUES TIME FRAME MATERIALIZES. PREV DRY RUNS UNDER THE EXPANSIVE RIDGE WITH WEAK FLOW ARE LOSING THE DRY FORECAST TO A SERIES OF SMALL WAVES AND WHAT LOOKS LIKE A STALLED BOUNDARY AT THE SFC ALONG THE OHIO RIVER VALLEY SIMILAR TO THE SAME PATTERN REPEATED THROUGH THIS SUMMER. WITH A LACK OF CONTINUITY OR CONSENSUS, SLIGHTS AND LOW CHANCE POPS THROUGH THE END WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1248 PM CDT WED JUL 22 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE ENTIRE 18Z TAF PERIOD. SCT DIURNAL CLOUDS AT AROUND 4000-5000FT THIS AFTERNOON WILL FADE AWAY BY SUNSET...LEAVING BEHIND ONLY SCT HIGH CLOUDS TONIGHT INTO THURSDAY MORNING. WINDS WILL BECOME LIGHT/VARIABLE OVERNIGHT AS RIDGE OF HIGH PRESSURE REMAINS OVERHEAD. DUE TO MOSTLY CLEAR SKIES/NEARLY CALM WINDS/AMPLE LOW-LEVEL MOISTURE...PATCHY FOG WILL BE POSSIBLE LATE TONIGHT. HAVE THEREFORE INCLUDED SOME MINOR VISBY RESTRICTIONS AT ALL TERMINALS BETWEEN 09Z AND 14Z. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...BARNES SHORT TERM...SMITH LONG TERM...HJS AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS PADUCAH KY
231 PM CDT WED JUL 22 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 231 PM CDT WED JUL 22 2015 MINOR DISTURBANCE SEEN OVER SW MO HEADING EAST WITH SOME UPTICK IN CONVECTION NOTED. HRRR HAS A REASONABLE HANDLE ON THIS ACTIVITY THROUGH 00Z-03Z...MOVING THE ACTIVITY EAST. LIGHTNING PROGS OFF THE REFRESH MODEL NOT IMPRESSIVE...AND AS PREVIOUSLY DISCUSSED... MID LEVEL MARGINAL LAPSE RATES AND WEAK ML CAPES MEANS WE WILL KEEP THUNDER MENTION AT ISOLATED. BETTER POPS WILL BE ACROSS SE MO INTO WRN KY AND SRN TIP OF IL INITIALLY. SHOULD REMAIN DRY EARLY TONIGHT UP ALONG THE I-64 CORRIDOR. SUPPOSE A SPRINKLE CANNOT BE RULED OUT THERE. OVERNIGHT...THE CHANCE OF CONVECTION WILL CONTINUE...WITH BEST POPS SRN 1/2 OF THE AREA. A SLIGHT NORTHWARD EXPANSION IS FORECAST ESPECIALLY BY THE NAM EVEN UP TOWARD THE KEVV TRI-STATE AS MOISTURE INCREASES THAT DIRECTION. WILL GUIDE POPS INTO THAT AREA. THURSDAY...BEST POPS WILL SHIFT SE WITH TIME COINCIDENT WITH THE DEPARTURE OF MID LEVEL ENERGY AND BEST MOISTURE...AND AS THE MID TROP FLOW VEERS MORE TO THE NW. THE VEERING WILL CONTINUE WITH DRYING INCREASING EAST OF THE MISSISSIPPI INTO THURSDAY NIGHT. WE DO CONTINUE WITH A CHANCE OF CONVECTION OVER SE MO WHERE MOISTURE AND INSTABILITY ARE FORECAST TO EXIST. THAT CHANCE WILL CONTINUE INTO AT LEAST THE FIRST 1/2 OF FRIDAY BEFORE HEADING SSE. FRIDAY NIGHT DRY FOR NOW...BUT THIS IS NOT A GIVEN. WE COULD SEE AN EASTWARD EXPANSION OF THE MOISTURE OUT OF MISSOURI WHICH COULD LEAD TO SOME LATE NIGHT CONVECTION. THERE IS CONSIDERABLE MODEL DISAGREEMENT WITH RESPECT TO THIS. WILL WAIT FOR A MORE CONSISTENT SIGNAL. TEMPERATURES ARE ESSENTIALLY A BLEND OF MOS. TRENDED AWAY FROM GFS MOS WHEN IT WAS AT ITS WARMEST ESPECIALLY FRIDAY. IT HAS NOT PERFORMED WELL AS OF LATE...ESPECIALLY DURING THE RECENT HEAT EVENT (OPPRESSIVE EVAPOTRANSPIRATION EFFECTS/HIGH DEW POINT AIR) IN WHICH AMBIENT TEMPS SEEMED TO REACH A LIMIT...JUST BELOW WHAT GUIDANCE WOULD PROJECT FOR HIGHS. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 231 PM CDT WED JUL 22 2015 THOUGH THE FINER DETAILS ARE MORE DIFFICULT TO PIN DOWN...THE GENERAL SCENARIO IN THE EXTENDED TIME FRAME WILL BE THE PAH FORECAST AREA WILL BE ON THE PERIPHERY OF A MID/UPPER LEVEL RIDGE OVER MOST OF THE SRN STATES. TWO MAIN NRN STREAM SHRTWVS ARE PROGGED BY THE MED RANGE MODELS TO MOVE BY TO THE NORTH...ONE DURING THE WEEKEND... AND ONE IN THE MIDDLE OF NEXT WEEK. EACH SHOULD ENHANCE SOMEWHAT THE LIKELIHOOD OF SHOWER AND TSTM DEVELOPMENT ACROSS PARTS OF OUR REGION. EARLY IN THE PERIOD...A NORTH-SOUTH FRONTAL BOUNDARY IS EXPECTED TO BE IN PLACE IN FAR WRN SECTIONS OF THE PAH FORECAST AREA. MEANWHILE...A LINGERING WEDGE OF RELATIVELY DRIER AIR WILL BE IN PLACE OVER THE REST OF THE REGION. LOW LEVEL WINDS SHOULD EVENTUALLY TURN AROUND TO THE SOUTH OVER THE WEEKEND...ENCOURAGING MORE MOISTURE ADVECTION INTO THE AREA. WITH THIS SETUP...AFTERNOON TEMPS AND DEWPOINTS SHOULD BE SEVERAL DEGREES HIGHER IN THE WEST VS. THE EAST ESPECIALLY SAT. THUS...HEAT INDICES COULD SPIKE TO HEAT ADVISORY CRITERIA IN THE WEST OVER THE WEEKEND. HEAT INDICES BETWEEN 100 AND 105 SHOULD BE MORE COMMON ACROSS THE ENTIRE REGION AFTERWARDS. THE MED RANGE MODELS GENERALLY DEPICT THE PRESENCE OF NRN STREAM SHRTWV ENERGY ALOFT IN THE AREA BY EARLY SUNDAY. THE DESTABILIZING EFFECT OF THIS FEATURE WILL COMBINE WITH THE INCREASINGLY UNSTABLE AIRMASS TO GENERATE SCATTERED SHOWER AND TSTM ACTIVITY PRIMARILY SUNDAY/SUNDAY NIGHT...WITH THE PENNYRILE REGION OF WRN KY HAVING THE LEAST POP. IF A SEWD-MOVING SFC BOUNDARY MAKES IT INTO OUR AREA BY SUNDAY NIGHT...IT MAY BECOME UNRECOGNIZABLE. THE MODEL BLEND SHOWS A PERSISTENT SRLY COMPONENT TO THE SFC WINDS THROUGH SUNDAY NIGHT AND BEYOND. IT APPEARS A SIMILAR PATTERN WILL SET UP EARLY NEXT WEEK...AS ANOTHER SFC BOUNDARY MAY SET UP IN THE FAR WEST...WITH ANOTHER (POSSIBLY STRONGER) SEWD-MOVING SFC BOUNDARY APPROACHING. THIS SHOULD MEAN SOMEWHAT DIMINISHED CHANCES OF SHOWERS/TSTMS POPPING UP UNTIL WED...WHEN THE PARENT SHRTWV WILL BE CLOSER TO THE REGION. SCATTERED ACTIVITY IS EXPECTED AGAIN BY THEN. RATHER WEAK FLOW ALOFT WILL NOT NECESSARILY BE CONDUCIVE TO SEVERE WEATHER IN OUR REGION. TEMPS/DEWPOINTS IN ANY ONE AREA ARE NOT EXPECTED TO CHANGE MUCH DURING THE EXTENDED PERIOD...OUTSIDE OF TSTM ACTIVITY. LOWER TO MIDDLE 90S WILL PREVAIL...WITH DEWPOINTS IN THE LOWER 70S FOR ALMOST THE ENTIRE TIME...YIELDING THE AFOREMENTIONED HEAT INDICES. && .AVIATION... ISSUED AT 1220 PM CDT WED JUL 22 2015 AREA IS ESSENTIALLY PRECIP FREE. CU/MID CLOUDS HAVE SCATTERED WITH LITTLE CLOUD COVER OVER KEVV TRI-STATE. NEXT WEAK MID LEVEL DISTURBANCE OVER SW MO WILL HEAD EAST ACCOMPANIED BY CHC SHRA MAINLY SE MO / WRN KY...SRN TIP OF IL LATE DAY / EARLY EVENING. COULD BE BRIEF MVFR RESTRICTIONS. OVERNIGHT SW OF PERRYVILLE MO...GREENVILLE KY LINE...MAY BE SOME MVFR CIGS VSBYS...BUT VFR CONDITIONS WITH MAINLY MID CLOUDS EXPECTED NE OF THERE INCLUDING KEVV / KOWB. THERE IS A CHANCE FOR ADDITIONAL CONVECTION. BUT CONFIDENCE TOO LOW TO INCLUDE AT TERMINALS AT THIS TIME. FUTURE UPDATES CAN ADD UPON INCREASED CONFIDENCE OVERNIGHT. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM...CN LONG TERM...DB AVIATION...CN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
315 PM EDT WED JUL 22 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT) ISSUED AT 310 PM EDT WED JUL 22 2015 18Z SFC ANALYSIS SHOWS HIGH PRESSURE BUILDING DEEPER INTO THE OHIO VALLEY AND NORTHERN KENTUCKY. THIS HAS BROUGHT DRIER AIR TO THE NORTHERN SECTIONS OF THE CWA WHERE SOME MID 50S ARE NOTED WHILE TO THE SOUTH MIDDLE AND UPPER 60S ARE COMMON. THE HIGH ALSO HELPED TO BREAK UP AND LIFT THE LOWER STRATUS DECK FROM THIS MORNING. ON SATELLITE AND RADAR...A PAIR OF MCVS ARE MOVING EAST INTO AND THROUGH THE TENNESSEE VALLEY. THE LEADING ONE OF THESE IS JUST ABOUT TO PUSH SOME LIGHT SHOWERS INTO THE CUMBERLAND VALLEY NEAR THE TENNESSEE BORDER. OTHERWISE...IT IS A PLEASANT ENOUGH DAY OUT THERE UNDER PARTLY SUNNY DAYS WITH TEMPERATURES RANGING FROM NEAR 80 NORTH TO THE MID 80S SOUTH ALONG WITH LIGHT NORTHWEST WINDS. THE MODELS ARE IN GOOD AGREEMENT WITH THE MAIN PATTERN ALOFT THROUGH THE SHORT TERM PORTION OF THE FORECAST. THEY ALL AGREE THAT FLAT FLOW CURRENTLY ABOVE KENTUCKY WILL BECOME MORE NORTHWESTERLY WITH TIME AS RIDGING BUILDS OVER THE SOUTHERN PLAINS INTO FRIDAY MORNING. DURING THIS TRANSITION...WEAK SHORTWAVES WILL RIDE THROUGH KENTUCKY STARTING WITH THE MCVS PASSING TO THE SOUTH THIS AFTERNOON AND TONIGHT. GIVEN THE SMALL SCALE NATURE OF THESE FEATURES WILL FAVOR THE HIGHER RESOLUTION NAM12 AND HRRR FOR WX DETAILS. SENSIBLE WEATHER WILL FEATURE A SMALL CHANCE FOR SHOWERS OR A STRAY THUNDERSTORM ACROSS THE SOUTHERN TIER THROUGH THE EVENING AND INTO THE OVERNIGHT AS THE MINOR MID LEVEL WAVES PASS BY. THE CLOUDS ASSOCIATED WITH THESE SHOULD KEEP THE FOG A BIT MORE LIMITED THROUGH THE NIGHT AND INTO THURSDAY MORNING. THE THREAT OF CONVECTION CONTINUES FOR MUCH OF THE SOUTHERN PARTS OF THE AREA DURING THE DAY THURSDAY...BUT WITH LITTLE IN THE WAY OF SUPPORT FOR ANYTHING BECOMING ORGANIZED OR TOO STRONG. THIS LEADS TO A BETTER CHANCE FOR VALLEY FOG LATER THURSDAY NIGHT AS THE WAVES PULL OUT OF KENTUCKY. TEMPERATURES WILL BE NEAR NORMAL OR A LITTLE ON THE COOL SIDE THROUGH FRIDAY MORNING. USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WINDS INTO TONIGHT AND THEN THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR ADJUSTMENTS TO THE LOWS TONIGHT AND THURSDAY NIGHT BASED ON TERRAIN DIFFERENCES AND THE EXPECTATION OF RIDGE TO VALLEY TEMPERATURE DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE DRIER MET MOS THAN THE MAV TONIGHT AND THURSDAY WHILE WAS IN LINE WITH THE LOW POP CONSENSUS FOR THURSDAY NIGHT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 245 PM EDT WED JUL 22 2015 UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BE ENTRENCHED OVER TEXAS AND THE SOUTHERN PLAINS THROUGH THE PERIOD KEEPING NORTHWEST FLOW IN PLACE ACROSS THE OHIO AND TENNESSEE VALLEYS. DRY HIGH PRESSURE WILL BE IN PLACE AT THE SURFACE FRIDAY AND SATURDAY WITH A DRY AND SEASONABLY WARM AND NOT SO HUMID FORECAST THE RESULT. A SHORTWAVE WILL THEN TRAVERSE THE US/CANADIAN BORDER OVER THE WEEKEND FLATTENING THE RIDGE AND SENDING A WEAK COLD FRONT SOUTHEASTWARD TOWARD OUR REGION. THE FRONT IS EXPECTED TO REMAIN IN THE VICINITY WHILE GRADUALLY WASHING OUT EARLY NEXT WEEK. THIS WILL KEEP A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS IN OUR FORECAST SUNDAY THROUGH WEDNESDAY...WITH COVERAGE LIKELY PEAKING IN THE AFTERNOON AND EARLY EVENING HOURS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 235 PM EDT WED JUL 22 2015 HIGH PRESSURE BUILDING INTO THE AREA HAS HELPED TO CLEAR THE MORNING FOG AND ALSO LIFT THE LOWER CIGS BY EARLY AFTERNOON. A SFC WAVE TRACKING TO OUR SOUTH AND AN APPROACHING MID LEVEL SHORTWAVE COULD BRING A FEW SHOWERS OR A STRAY STORM TO THE WESTERN AND SOUTHERN TAF SITES LATE TONIGHT AND INTO THE DAY ON THURSDAY. ACCORDINGLY...HAVE INCLUDED A VCTS AND CB IN THE SOUTHERN TAFS ALONG WITH LOWERING CIGS FOR THIS TIME. WINDS THROUGH THE PERIOD WILL BE MAINLY LIGHT AND VARIABLE FOR ALL SITES. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GREIF LONG TERM...ABE AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1214 PM CDT WED JUL 22 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 338 AM CDT WED JUL 22 2015 FOCUS WILL BE ON THE CHANCE FOR RAIN TODAY AND TONIGHT. MOST NOTABLE THING WILL BE THE FACT THESE CHANCES HAVE DIMINISHED ACROSS THE FORECAST AREA. TEMPERATURES WILL BE BELOW NORMAL FOR HIGHS TODAY...BUT LOWS WILL BE ABOVE NORMAL LATER TONIGHT. AT THE SURFACE...AN AREA OF HIGH PRESSURE IS CENTER EAST OF THE FORECAST AREA...WHICH SHOULD KEEP US IN A SOUTHERLY WIND PATTERN THROUGH THE SHORT TERM WITH SPEEDS GENERALLY AROUND/UNDER 10 MPH. WE LACK A TRIGGERING MECHANISM TODAY...AND CAPE VALUES ARE NIL TO VERY LOW FOR MOST OF THE DAY. MUCAPE VALUES START TO PICK UP THIS AFTERNOON...ESPECIALLY ACROSS OUR SOUTHWEST AND SOUTH...WITH VALUES MOSTLY AROUND THE 500-1500 J/KG RANGE. THE NAM SUGGEST VALUES COULD BE AS HIGH AS 2000 J/KG BUT THIS IS THE MORE AGGRESSIVE SOLUTION. 0- 6 KM BULK SHEAR VALUES RANGE BETWEEN 20-35 KNOTS. 0-1 KM HELICITY VALUES VARY GREATLY BETWEEN THE NAM...GFS...AND EUROPEAN. OVERALL...THESE VALUES ARE VERY LOW UNTIL TONIGHT WHEN VALUES RANGE BETWEEN 80-150 M^2/S^2 OVERNIGHT. WITHOUT A TRUE TRIGGERING MECHANISM TODAY...WE ARE RELYING SOLELY ON ISENTROPIC LIFT WHICH IS NOT BACK ACROSS KANSAS...AND THIS IS REFLECTED IN THE FORECAST WITH HIGHER POPS ACROSS THE SOUTH. WE ARE REALLY GOING TO STRUGGLE TO GET RAINFALL TODAY. MANY OF THE SIMULATED REFLECTIVITY MODELS SUGGEST MOSTLY DRY CONDITIONS OVER THE SHORT TERM. THE HRRR IS REALLY THE MOST OPTIMISTIC FOR RAINFALL CHANCES TODAY. NMM...ARW...AND THE NAM4KM ALL HAVE MOSTLY DRY CONDITIONS. I HAVE DECREASED POPS FROM THE PREVIOUS FORECAST TO REFLECT THIS TREND. HIGHER CHANCES WILL BE TONIGHT...ESPECIALLY FOR AREAS GENERALLY SOUTH OF INTERSTATE 80. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 338 AM CDT WED JUL 22 2015 GUIDANCE SUGGESTS GENERALLY WEAK QUASI-ZONAL UPPER TROPOSPHERIC FLOW WILL EXIST OVER THE CENTRAL PLAINS TO START THE LONG-TERM FORECAST PERIOD AT 12Z THURSDAY. GUIDANCE SUGGESTS THIS WEAK UPPER TROPOSPHERIC FLOW WILL CONTINUE OVER OUR AREA THROUGH NEXT SUNDAY AS UPPER TROPOSPHERIC RIDING STRENGTHENS ACROSS THE AREA. SOME BREAKDOWN IN THE RIDGE IS THEN EXPECTED EARLY NEXT WEEK AS AN UPPER TROPOSPHERIC SHORT WAVE MOVES FROM THE NORTHWESTERN CONUS INTO THE NORTH CENTRAL CONUS. IT APPEARS OMEGA WILL REMAIN ON THE WEAK SIDE ACROSS OUR AREA DURING MUCH OF THE LONG-TERM FORECAST PERIOD...WHICH INCLUDES EARLY NEXT WEEK WITH THE AFOREMENTIONED UPPER TROPOSPHERIC SHORT WAVE REMAINING NORTH OF OUR AREA. THAT SAID...VARIOUS SETS OF GUIDANCE CONTINUE TO SUGGEST AN UPPER TROPOSPHERIC PERTURBATION OR TWO COULD CLEAR THE REGION LATE THIS WEEK INTO EARLY NEXT WEEK...AND THERE REMAIN SIGNALS THAT HIGH PLAINS CONVECTION COULD SUSTAIN ITSELF LONG ENOUGH TO IMPACT OUR AREA DURING THE EVENING AND OVERNIGHT HOURS BETWEEN THURSDAY AND TUESDAY. GIVEN ALL THIS...WENT AHEAD WITH GENERALLY 20- 40% POPS ACROSS VARIOUS PORTIONS OF THE CWA BETWEEN THURSDAY EVENING AND NEXT TUESDAY. AS MENTIONED YESTERDAY...LOW VALUES DEEP-LAYER SHEAR AND HIGH VALUES OF POTENTIAL ENERGY SHOULD PRESENT ITSELF ACROSS MUCH OF THE AREA DURING THE LONG-TERM FORECAST PERIOD. ALTHOUGH THERE REMAINS CONSIDERABLE UNCERTAINTY WITH RESPECT TO THE TIMING AND PLACEMENT OF CONVECTIVE INITIATION FROM DAY TO DAY...GIVEN THE FACT THAT GUIDANCE SUGGESTS POTENTIAL ENERGY VALUES OF ~2000J/KG WILL BE REALIZED ACROSS MUCH OF THE AREA BOTH THURSDAY AND FRIDAY...FELT IT PRUDENT TO GO WITH A MENTION OF STRONG THUNDERSTORM ACTIVITY IN THE HWO FOR THURSDAY EVENING AS WELL AS FRIDAY AFTERNOON AND EVENING. MUCH WARMER WEATHER IS STILL EXPECTED DURING THE LONG-TERM FORECAST PERIOD...WITH HIGHS GENERALLY IN THE UPPER 80S AND 90S ON MOST DAYS...AND PERHAPS APPROACHING 100 DEGREES FOR SOME LOCATIONS ON FRIDAY. GUIDANCE ALSO SUGGESTS BOUNDARY-LAYER DEW POINTS IN THE UPPER 60S TO MID 70S WILL HELP PROMOTE HEAT INDEX READINGS NEAR 100 DEGREES FOR PORTIONS OF THE OUTLOOK AREA BOTH THURSDAY AND SATURDAY...AND AROUND 105 DEGREES ON FRIDAY. WILL GO AHEAD AND CONTINUE WITH THE HEAT INDEX WORDING IN THE HWO AS A RESULT. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1209 PM CDT WED JUL 22 2015 AN AREA OF CONVECTION IS EXPECTED TO SKIRT NORTH OF THE TERMINALS THIS AFTERNOON. MODELS ARE HIT AND MISS ON REDEVELOPMENT OF STORMS TONIGHT AS THE LLVL JET STRENGTHENS BUT BETTER CHCS FOR THIS APPEARS EAST OF THE TERMINALS. OTHERWISE...CLOUD COVER IS FAIRLY VARIABLE DUE TO CONVECTION AROUND AND CIGS RANGE FROM NEAR IFR TO VFR. HAVE INCLUDED A PERIOD OF MVFR CIGS THIS AFTN AND WILL NEED TO MONITOR POTENTIAL FOR A BRIEF VSBY IN BR AND A LOWER CIG TONIGHT AS WELL. WINDS WILL REMAIN FROM A SOUTHEAST DIRECTION. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...GUERRERO LONG TERM...BRYANT AVIATION...FAY
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1227 PM CDT WED JUL 22 2015 .UPDATE... ISSUED AT 1227 PM CDT WED JUL 22 2015 NO CHANGES FROM THE PREVIOUS UPDATE. UPDATE ISSUED AT 956 AM CDT WED JUL 22 2015 SKY COVER AND POPS WERE ADJUSTED TO FIT LATEST OBSERVATIONS AND RADAR IMAGERY. TWO EMBEDDED S/WV IMPULSES MOVING THROUGH THE MID LEVEL RIDGE TRIGGERING CONVECTION THIS MORNING ACROSS NORTHEASTERN MONTANA AND NORTHEASTERN SOUTH DAKOTA. A FEW OF THESE STORMS MAY MIGRATE OR DEVELOP INTO THE SOUTHERN JAMES RIVER VALLEY...ALTHOUGH BETTER CHANCE THAT CONVECTION IN NORTHEASTERN MONTANA WILL CROSS THE BORDER INTO NORTHWEST NORTH DAKOTA OVER THE NEXT FEW HOURS. NOTHING SEVERE EXPECTED. HIGH RES MODELS DEVELOP ISOLATED STORMS THIS AFTERNOON WEST AND OVER THE JAMES RIVER VALLEY...SO WILL MAINTAIN/ADD A LOW POP FOR THESE AREAS. OTHER FORECAST ELEMENTS ON TRACK FOR THE MID/LATE MORNING UPDATE. UPDATE ISSUED AT 650 AM CDT WED JUL 22 2015 FORECAST GENERALLY ON TRACK. MADE A FEW MINOR ADJUSTMENTS TO SKY AND BLENDED OTHER ELEMENTS TO LATEST OBSERVATIONS. CONTINUED TO CARRY LOW POPS ACROSS SOUTHEAST AND NORTHWEST. RADAR SHOWED A FEW THUNDERSTORMS OVER NORTHEAST MONTANA SLOWLY APPROACHING NORTHWEST ND. HIGH RES MODELS CONTINUE TO SHOW A FEW SHOWERS POSSIBLE ACROSS THE FAR SOUTHEAST AS WELL...THOUGH CURRENT RADAR HAS ANY ACTIVITY OUTSIDE OUR CWA AT THE MOMENT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 317 AM CDT WED JUL 22 2015 THUNDERSTORMS WILL BE THE FOCUS FOR THE SHORT TERM. A WARM FRONT WILL CONTINUE TO LIFT NORTHEAST ACROSS THE STATE THIS MORNING. ISOLATED THUNDERSTORMS MAY DEVELOP ALONG THE FRONT THROUGH THE MORNING HOURS ACROSS THE JAMES VALLEY. THE LATEST (7UTC) HRRR IS A LITTLE TOO ROBUST WITH THUNDERSTORM DEVELOPMENT ACROSS THE VALLEY AS IT HAS THUNDERSTORMS ACROSS PORTIONS OF LOGAN...MCINTOSH...LAMOURE AND DICKEY COUNTIES...YET CURRENT RADAR TRENDS INDICATE ONLY ISOLATED THUNDERSTORMS WELL TO THE EAST. A COLD FRONT AND SURFACE TROUGH WILL SLOWLY ENTER WESTERN NORTH DAKOTA THIS EVENING/OVERNIGHT. SHOWERS AND THUNDERSTORMS ARE SHOWN DEVELOPING ALONG THE FRONT IN THE HRRR/RAP/WRF/NAM. SCATTERED STORMS ARE POSSIBLE THROUGH THE NIGHT ACROSS WESTERN NORTH DAKOTA. TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGREES WARMER THAN YESTERDAY AS WAA CONTINUES AND WE BECOME FULLY ENTRENCHED IN THE WARM SECTOR. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 317 AM CDT WED JUL 22 2015 MAIN FORECAST ISSUE CONTINUES TO BE THUNDERSTORM TIMING...COVERAGE AND POSSIBILITY OF SEVERE ON THURSDAY. MODELS ARE GENERALLY ON THE SAME TRACK...ALTHOUGH GFS HAS A SLIGHTLY FARTHER NORTHWARD PLACEMENT OF QPF COMPARED TO NAM/ECMWF/SREF. GFS APPEARS TO HAVE A SLIGHTLY WEAKER VORT MAX MOVING ACROSS SOUTHWESTERN AND CENTRAL ND IN WEST/SOUTHWEST FLOW. FOR THE FORECAST...FOLLOWED THE NAM/ECMWF SOLUTIONS WITH A MORE SOUTHWARD DEVELOPMENT OF CONVECTION WHICH IS ALSO MORE IN LINE WITH THE SPC DAY 2 CONVECTIVE OUTLOOK SHOWING SLIGHT RISK OF SEVERE THUNDERSTORM AREA OVER ALL BUT FAR WESTERN ND ON THURSDAY. ALL MODELS FORECAST AMPLE INSTABILITY WITH UPWARDS OF 2000-3000 J/KG OF SURFACE BASED CAPE ACROSS CENTRAL AND EASTERN ND BY 18Z WITH SURFACE LOW AND ASSOCIATED COLD FRONT INTO WESTERN ND...WHICH WILL SERVE AS A FOCUS FOR CONVECTIVE DEVELOPMENT. 0-6KM SHEAR STARTS OUT AROUND 20-25KTS AT 18Z THU PER GFS/NAM WITH STRONGER VALUES DISPLACED WEST OF BEST CAPE...EVENTUALLY INCREASING TO 30-35KTS BY THURSDAY EVENING ACROSS THE STATE. STORMS SHOULD BE EXITING EASTERN CWA BETWEEN 06Z AND 12Z FRIDAY. QUASI-ZONAL FLOW DEVELOPS THROUGH EARLY WEEKEND BEFORE A DEEPER LONGWAVE TROUGH MOVES THROUGH THE PAC NW BRINGING ANOTHER LOW PRESSURE SYSTEM THROUGH MONTANA...BRUSHING WESTERN ND AND INTO SOUTHERN CANADA. OVERALL WILL CONTINUE TO SEE PERIODIC...GENERALLY LOW CHANCES OF PRECIP THROUGH REMAINDER OF EXTENDED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1227 PM CDT WED JUL 22 2015 VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...AJ LONG TERM...JNS AVIATION...NH
AREA FORECAST DISCUSSION
NWS TULSA OK
1142 AM CDT WED JUL 22 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. MVFR CIGS REMAIN AT BVO...WITH OCCASIONALLY MVFR CONDITIONS AT FYV/XNA/ROG AS WELL. THESE SHOULD IMPROVE DURING THE FIRST COUPLE OF HOURS OF THE TAF PERIOD. SHRA/TSRA WILL AFFECT ALL TERMINALS THIS AFTERNOON...WITH TSRA AFTER MIDNIGHT AND INTO TOMORROW MORNING IMPACTING THE NW AR TERMINALS. && .PREV DISCUSSION... /ISSUED 938 AM CDT WED JUL 22 2015/ ..UPDATE... DISCUSSION... SCATTERED THUNDERSTORMS PERSIST THIS MORNING GENERALLY ALONG THE INTERSTATE 40 CORRIDOR IN A REGION OF MID LEVEL WARM ADVECTION. THESE WILL CONTINUE TO PUSH OFF TO THE EAST THROUGH THE REST OF THE MORNING AND INTO EARLY AFTERNOON. ANOTHER BATCH OF STORMS REMAINS ACROSS NORTHWEST OKLAHOMA...ALSO MOVING TO THE EAST. IT HAS EXHIBITED SOME WEAKENING OVER THE PAST HOUR OR SO...ALTHOUGH NOT AS DRASTIC AS THE HRRR WOULD SUGGEST. WITH INSTABILITY BEING FAIRLY LOW ACROSS NORTH CENTRAL AND NORTHEAST OKLAHOMA...WOULD EXPECT THESE TO WEAKEN FURTHER AS THEY NEAR THE FORECAST AREA. HAVE MADE A FEW TWEAKS TO THE POP AND QPF FORECAST TO FOCUS HIGHER POPS AND FORECAST RAINFALL ALONG INTERSTATE 40...AND LOWER THEM SOME IN FAR NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS. UPDATES ALREADY OUT. PREV DISCUSSION... /ISSUED 634 AM CDT WED JUL 22 2015/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE THIS MORNING MAINLY OVER SOUTHEAST OK AND WESTERN AR. A FEW AREAS OF IFR AND LIFR CIGS WILL BE POSSIBLE...WITH IMPROVEMENT EXPECTED THIS AFTERNOON. SCATTERED THUNDERSTORM REDEVELOPMENT WILL BE POSSIBLE LATER THIS AFTERNOON...WITH ANOTHER THUNDERSTORM COMPLEX POSSIBLY IMPACTING FAR NORTHEAST OK/NORTHWEST ARKANSAS LATER TONIGHT. PREV DISCUSSION... /ISSUED 356 AM CDT WED JUL 22 2015/ DISCUSSION... ONGOING AREA OF SHOWERS AND THUNDERSTORMS AFFECTING MAINLY AREAS SOUTH OF I-44 AND NORTH OF I-40 WITH 2-3 INCH RAINFALL AMOUNTS FAIRLY COMMON AS SOME TRAINING OF CELLS HAS BEEN NOTED. OVERALL TREND HAS BEEN FOR THIS AREA TO BE PROGRESSIVE AND SHOULD CONTINUE TO PUSH SLOWLY EAST THROUGH EARLY THIS MORNING. STORMS CONTINUE TO BE EFFICIENT RAIN MAKERS AND A FEW AMOUNTS OF 4-5 INCHES REMAIN POSSIBLE WITH LOCAL FLOODING ISSUES PROBABLE. ADDITIONAL SHOWERS AND STORMS HAVE BEEN ON THE INCREASE ACROSS SW KANSAS OVER THE PAST COUPLE OF HOURS AND WHILE IT IS POSSIBLE THESE COULD MAKE A RUN AT NE OKLAHOMA BY THIS AFTERNOON...WOULD EXPECT DECREASING TREND HERE AS WELL WITH WANING LOW LEVEL JET SUPPORT THROUGH THE MORNING. FRONTAL BOUNDARY WILL BEGIN LIFTING NORTH TODAY AND WILL NEED TO BE WATCHED FOR ADDITIONAL THUNDERSTORM DEVELOPMENT THIS AFTERNOON. ANY STORMS DURING THE AFTERNOON WOULD BE CAPABLE OF BECOMING STRONG WITH GUSTY WINDS POSSIBLE. MORE WIDESPREAD STORMS AGAIN TONIGHT NORTH OF THE BOUNDARY...MOSTLY ACROSS KS/MO. HOWEVER SOME OF THE LATEST DATA SUGGESTS THIS COULD BRUSH FAR NE OKLAHOMA AND NW ARKANSAS LATER TONIGHT. AFTER TONIGHT THE HEAT WILL BE ON ONCE AGAIN AS MID LEVEL HEIGHTS RISE WITH STRENGTHENING RIDGE. DEW POINTS WILL REMAIN HIGH AND HEAT INDEX VALUES SHOULD EASILY EXCEED 105 IN SOME AREAS BY THURSDAY AND MUCH OF THE AREA BY FRIDAY AND BEYOND. HOT WEATHER WILL PERSIST INTO NEXT WEEK WITH SOMEWHAT DEEPER LOW LEVEL MOISTURE PERHAPS WORKING INTO EASTERN AREAS BY TUESDAY RESULTING IN SLIM CHANCE OF SHOWERS AND THUNDERSTORMS IN TERRAIN AREAS. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...22
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1228 PM CDT WED JUL 22 2015 .AVIATION UPDATE... MCV CONTINUES TO MOVE EAST ACROSS CWA. -RA WILL AFFECT BNA OVER THE NEXT COUPLE OF HOURS. CSV WILL LIKELY SEE SOME -RA AS WELL THIS AFTERNOON. CKV COULD ESCAPE MOST OF THE AFTERNOON DRY ALTHOUGH HRRR IS BRINGING SOME SHOWERS AND STORMS TOWARD CKV THIS EVENING. RAIN CHANCES WILL REMAIN FOR THE REST OF THE TAF PERIOD WITH A SERIES OF DISTURBANCES IN MID LEVEL FLOW. CONFIDENCE IS NOT HIGH ENOUGH TO PIN DOWN TIMING OF LATER RAIN SO ADDRESSED IT WITH VCSH. BR COULD BECOME AN ISSUE PARTICULARLY AT CSV TONIGHT. WINDS WILL BE LIGHT AND VARIABLE FOR THE AFTERNOON AND OVERNIGHT BEFORE LIGHT SW WINDS AFTER DAYBREAK TOMORROW. && .PREV DISCUSSION... /ISSUED 1039 AM CDT WED JUL 22 2015/ UPDATE... A COMPLEX OF SHOWERS AND A FEW RUMBLES OF THUNDER ASSOCIATED WITH SHORT WAVE DISTURBANCE IS CURRENTLY PUSHING EAST THROUGH NASHVILLE METRO. AN MCV CAN BE NOTED ON RADAR AS WELL AS THE VIS SATELLITE CENTERED OVER HICKMAN COUNTY. THIS COMPLEX LOOKS LIKE IT WILL HOLD TOGETHER AS IT CONTINUES EAST ACROSS THE REMAINDER OF THE CWA. BUMPED UP POPS EAST OF NASHVILLE. ACTIVITY IN MEG`S CWA IS ON THE DOWNSWING. AFTER CURRENT ACTIVITY PUSHES THROUGH SOME ATMOSPHERIC RECOVERY WILL BE POSSIBLE THIS AFTERNOON TO ALLOW MORE SCATTERED SHOWERS AND STORMS. THE SPC 13Z DAY 1 OUTLOOK HAD THE SW THIRD OF THE CWA IN A MARGINAL RISK FOR AN ISOLATED SEVERE WIND GUST. NOT CONFIDENT IN THE AMOUNT OF RECOVERY THAT CAN OCCUR BUT IF A STRONG STORM DOES OCCUR IT WOULD BE CLOSER TO THE AL BORDER IN VICINITY OF WEAK QUASI STATIONARY FRONT. REAGAN && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 72 86 71 91 / 50 60 20 20 CLARKSVILLE 70 85 70 90 / 40 60 20 20 CROSSVILLE 68 80 67 84 / 30 60 20 10 COLUMBIA 71 88 70 91 / 40 60 30 20 LAWRENCEBURG 71 88 71 92 / 30 60 40 30 WAVERLY 70 86 70 90 / 50 60 20 20 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 10
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND THURSDAY ISSUED AT 242 PM CDT WED JUL 22 2015 NORTHWESTERLY FLOW CONTINUES ACROSS THE WESTERN GREAT LAKES AS A SURFACE HIGH PRESSURE RIDGE CONTINUES TO HOLD. CURRENT SURFACE ANALYSIS SHOWS A WEAKNESS IN THE RIDGE ACROSS NORTHERN WISCONSIN WITHIN THE RIDGE...WHICH APPEARS TO BE A WEAK WARM FRONT. RADAR AND VISIBLE SATELLITE TRENDS INDICATE THE HI-RES HRRR RUNS ARE FAIRLY ON POINT IN DEVELOPING SHOWERS ACROSS THIS BOUNDARY THIS AFTERNOON AS A WEAK SHORTWAVE TRACKS THROUGH THE WESTERN GREAT LAKES. THEREFORE WILL PLACE ISOLATED SHOWERS ACROSS THE CENTRAL CWA WITH THIS ACTIVITY...WHICH SHOULD WANE QUICKLY ONCE THE SUN GOES DOWN. DRY CONDITIONS ARE EXPECTED TONIGHT WITH THE LOSS OF DAYTIME HEATING AS THE CUMULUS CLOUDS DISSIPATE QUICKLY. HOWEVER ANOTHER SHORTWAVE WILL BRING SOME MID-LEVEL CLOUDINESS AT TIMES. THE SURFACE RIDGE BEGINS MOVING EAST ON THURSDAY AS WEAK LOW LEVEL WARM AIR ADVECTION CONTINUES. DESPITE MUCH IN THE WAY OF FORCING...THE NWP MODELS ARE STILL ON TRACK TO PRODUCE SOME SHOWERS AND THUNDERSTORMS ACROSS NORTHERN WISCONSIN IN THE VICINITY OF A WEAK WARM FRONT. GIVEN THE CONTINUED MODEL CONSENSUS AMONGST THE MEMBERS AND FROM RUN TO RUN WILL MAINTAIN THE LOW POPS ACROSS THIS AREA FOR THURSDAY. HIGHS ON THURSDAY SHOULD WARM A FEW MORE DEGREES GIVEN CONTINUED WARM AIR ADVECTION...WITH HIGHS GENERALLY IN THE LOWER TO MIDDLE 80S. IN ADDITION TO THE WARMER TEMPERATURES...DEW POINTS RISING TO AROUND 60 DEGREES WILL MAKE CONDITIONS FEEL A BIT MORE HUMID THAN TODAY. .LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY ISSUED AT 242 PM CDT WED JUL 22 2015 500 MB ZONAL FLOW WILL CONTINUE INTO EARLY NEXT WEEK...THEN WESTERN RIDGE WILL BUILD BY THE END OF NEXT WEEK. AN ISOLATED SHOWER OR STORM IS POSSIBLE EARLY THURSDAY EVENING. ATTENTION THEN TURNS TO COLD FRONT THAT WILL APPROACH WISCONSIN FRIDAY MORNING. SYSTEM IS A TAD BIT FASTER TODAY THAN YESTERDAY. MODIFIED SOUNDINGS INDICATED 1500 TO 3000 J/KG OF CAPE. WIND SHEAR VALUES OF 30 TO 40 KNOTS NOTED ON THE MODELS DURING THIS PERIOD. MAIN CONCERN IS WARM LAYER ALOFT MAY INHIBIT CONVECTION FROM DEVELOPING UNTIL LATE IN THE DAY DUE TO DAYTIME HEATING AND THE APPROACH OF THE COLD. SOME OF THE STORMS COULD BECOME STRONG OR SEVERE WITH DAMAGING WINDS...LARGE HAIL AND TORRENTIAL RAINFALL. THE GREATEST SEVERE POTENTIALS LOOKS TO BE NORTH AND WEST OF THE FOX VALLEY AT THIS POINT. HOWEVER...STRONG SHEAR ALOFT LEAVES THE POTENTIAL FOR SOME STRONG OR SEVERE STORMS ACROSS NORTHEAST AND EAST-CENTRAL WISCONSIN OVERNIGHT. ANY LINGERING SHOWER OR STORM ACTIVITY SHOULD EXIT THE REGION SATURDAY MORNING WITH DRY CONDITIONS SATURDAY AFTERNOON. THE NEXT CHANCE FOR SHOWERS AND STORMS WILL BE TUESDAY INTO WEDNESDAY MORNING WITH NEXT COLD FRONT MOVING THROUGH THE REGION. IT IS TOO EARLY TO DETERMINE IF ANY OF THESE STORMS WOULD BECOME STRONG OR SEVERE. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1217 PM CDT WED JUL 22 2015 SURFACE HIGH PRESSURE RIDGE WILL SLOWLY MOVE EAST ACROSS THE FORECAST AREA THIS AFTERNOON WITH VFR CONDITIONS PREVAILING THROUGH THE FORECAST PERIOD. HOWEVER...WEAK LOW-LEVEL WARM ADVECTION IN CONCERT WITH WEAK UPPER-LEVEL IMPULSES APPROACHING THE AREA...WILL LEAD TO INCREASING MIDDLE AND HIGH-LEVEL CLOUDS DURING THE DAY. A FEW LIGHT SPOTTY HIGH-BASED SHOWERS ARE POSSIBLE MAINLY NORTH OF A LINE FROM GRB TO AUW AFTER 20 OR 21 UTC THIS AFTERNOON. AS THIS ACTIVITY IS EXPECTED TO BE VERY SPOTTY AND OF LITTLE CONSEQUENCE...IT WILL NOT BE INCLUDED IN THE 18Z TAFS. OVERNIGHT VFR CONDITIONS EXPECTED WITH PERHAPS SOME PATCHY FOG DEVLOPING ESPECIALLY WEST AND NORTH OF THE FOX VALLEY AFTER 09Z. CONFIDENCE TOO LOW TO INCLUDE MENTION OF BR IN TAFS AT THIS TIME. GENERALLY VFR CONDITIONS ON THURSDAY WITH SW BOUNDARY LAYER WINDS OF 5 TO 10 KTS BY AFTERNOON. A SMALL CHANCE FOR SHOWERS OR PERHAPS A THUNDERSTORM EXISTS IN THE VICINITY OF A WEAK WARM FRONT ACROSS NORTHERN WISCONSIN THURSDAY AFTERNOON. THE FOX VALLEY AND EASTCENTRAL AREAS SHOULD REMAIN DRY WITH SCT-BKN MID- LEVEL CLOUDINESS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....KURIMSKI LONG TERM......ECKBERG AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
231 PM MDT WED JUL 22 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 230 PM MDT WED JUL 22 2015 LATEST WATER VAPOR DEPICTING LAST OF MONSOONAL MOISTURE ACROSS SOUTHEAST WYOMING THIS AFTERNOON. SIGNIFICANT DRYING ON WATER VAPOR OVER MOST OF COLORADO IS INCHING EVER SO SLOWLY NORTHWARD TOWARDS THE SOUTHERN WYOMING BORDER. SEEING SCATTERED SHOWERS AND THUNDERSTORMS ON AREA RADAR THIS AFTERNOON...MAINLY ALONG THE WYOMING/COLORADO BORDER AND MOUNTAIN RANGES TO OUR WEST AND NORTH. SURFACE BASED CAPE OFF THE MESOANALYST PAGE SHOWING RIGHT AROUND 500 J/KG WHERE THESE THUNDERSTORMS ARE FORMING...SO DO NOT EXPECT ANY SEVERE TSTMS FROM THESE. BETTER INSTABILITY ACROSS THE PANHANDLE WHERE CAPES ARE RUNNING 1500-2500 J/KG AT 1 PM THIS AFTERNOON. DEWPOINTS ACROSS THE PANHANDLE NEAR 60 FOR ALLIANCE...SCOTTSBLUFF AND SIDNEY. WILL NEED TO WATCH THUNDERSTORM EVOLUTION AS THE AFTERNOON PROGRESSES OUT THAT WAY. LATEST HRRR FORECAST RADAR SHOWING THE POSSIBILITY OF A FEW STRONG STORMS MAKING IT INTO THIS MORE UNSTABLE AIR IN THE PANHANDLE THIS AFTERNOON AROUND 00Z. CAN NOT RULE OUT ONE OR TWO SEVERE STORMS FOR THIS EVENING OUT THAT WAY. SHEAR OUT THAT WAY ALMOST NONEXISTENT...WITH LONG SKINNY CAPE PROFILES...SO THINK THE MORE PROMINENT HAZARD WOULD BE HEAVY RAIN. ATTENTION TURNS TO ELEVATED FIRE CONDITIONS THURSDAY AND FRIDAY. GFS FORECASTING THE LOW PRESSURE SYSTEM CURRENTLY OVER SOUTHERN BRITISH COLUMBIA...TO TRACK INTO NORTHERN MONTANA THURSDAY. THIS IS A FAVORABLE WIND PATTERN FOR SOUTHEAST WYOMING. AS A RESULT...WESTERLY WINDS BEGIN TO INCREASE OUT ACROSS CARBON AND ALBANY COUNTIES. GFS 700MB WINDS OF 30-35KTS THURSDAY AFTERNOON. LOOKS LIKE THE AREA WILL MIX UP TO AT LEAST 580MBS OUT THAT WAY. NAM WINDS UP AROUND THAT LEVEL FORECAST AT 35-40KTS...SO CARBON AND ALBANY COUNTIES COULD BE SEEING WINDS GUSTING TO 40MPH OR MORE. FORTUNATELY...FUELS ARE STILL BEING REPORTED AS NOT READY FOR MOST FIRE ZONES...SO RED FLAG WARNINGS ARE NOT EXPECTED. WINDS EASE SOME FRIDAY AS THE LOW TRACKS EAST INTO SOUTHERN ALBERTA CANADA AND EASTWARD. LESS CLOUD COVERAGE AND 700MB TEMPERATURES CLIMBING TO +16C FRIDAY AND SATURDAY SHOULD LEAD TO SOME VERY WARM TEMPERATURES. DID GO OVER GUIDANCE ON HIGHS FOR THURSDAY AND FRIDAY. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 230 PM MDT WED JUL 22 2015 UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS/HIGH PLAINS WILL MEANDER OVER THAT GENERAL AREA THROUGH THIS PERIOD. THE CWA WILL RESIDE ON THE NORTHERN PERIPHERY OF THE HIGH WITH WARM AND MAINLY DRY WEATHER EXPECTED OVERALL...WITH THE WARMEST DAYS SATURDAY THROUGH MONDAY. A COUPLE DISTURBANCES SHOULD ROTATE OVER THE HIGH AND MAY BRING SOME CONVECTION TO PARTS OF THE CWA...MAINLY SUNDAY AND WEDNESDAY. MONSOONAL MOISTURE LOOKS LIKE IT WILL REMAIN CUT OFF FOR THE MOST PART. AN UPPER LOW WILL MOVE EAST ACROSS THE SOUTHERN CANADIAN PRAIRIES MONDAY THROUGH TUESDAY AND SHOULD DRIVE A COOL FRONT ACROSS THE CWA MONDAY NIGHT WITH TEMPS LOWERING CLOSER TO SEASONAL AVERAGES FOR TUESDAY AND WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1125 AM MDT WED JUL 22 2015 VFR EXPECTED OVERALL OVER THE TERMINALS THROUGH THE PERIOD. THERE WILL BE WDLY SCTD SHOWERS AND TSTRMS DEVELOPING OVER THE SE WY MTNS THIS AFTERNOON AND MOVING EAST OVER PARTS OF THE PLAINS INTO THIS EVENING BEFORE ENDING. BRIEF PDS OF GUSTY WINDS AND MVFR VSBYS IN STRONGER ACTIVITY. && .FIRE WEATHER... ISSUED AT 230 PM MDT WED JUL 22 2015 A DRIER AND MORE WINDY PERIOD AHEAD FOR THE REMAINDER OF THE WEEK AFTER SHOWERS AND THUNDERSTORMS END TODAY. MONSOONAL MOISTURE FORECAST TO BE SUPPRESSED SOUTH AND EAST BY THURSDAY. LOW PRESSURE TRACKING THROUGH NORTHERN MONTANA THURSDAY WILL AID IN INCREASING WESTERLY TO SOUTHWESTERLY WINDS...ESPECIALLY WEST OF THE LARAMIE RANGE THURSDAY AND FRIDAY. ELEVATED FIRE WEATHER CONCERNS WITH THESE WINDS AND AFTERNOON HUMIDITIES FALLING TO 15 PERCENT BOTH AFTERNOONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...GCC LONG TERM...RE AVIATION...RE FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1125 AM MDT WED JUL 22 2015 .UPDATE... ISSUED AT 1039 AM MDT WED JUL 22 2015 LATEST HRRR SHOWING SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE SOUTH LARAMIE RANGE AND MOVING OUT INTO THE WESTERN NEBRASKA PANHANDLE THIS AFTERNOON. WENT AHEAD AND ADDED SLIGHT CHANCE POPS INTO THE PANHANDLE FOR LATE AFTERNOON. UPDATES HAVE BEEN SENT. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 325 AM MDT WED JUL 22 2015 SKIES ARE GENERALLY CLEAR OVER SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE BEHIND THE SHORTWAVE THAT MOVED OVERHEAD YESTERDAY. HEIGHTS WILL RISE THROUGH THE DAY AND THE 500MB RIDGE AXIS WILL BE LOCATED OVER SOUTHEAST WY BY THIS AFTN. CONVECTIVE COVERAGE WILL BE LESS TODAY ESPECIALLY OVER THE NEBRASKA PANHANDLE. WITH SOUTHWESTERLY 700 TO 500 MB FLOW THERE IS STILL GOOD SUBTROPICAL MOISTURE STREAMING INTO SOUTHEAST WYOMING DURING PEAK HEATING AND PW VALUES ARE 0.75 TO 1 INCH. THUS...EXPECTING ISOLATED TO SCATTERED TSTMS TO DEVELOP THIS AFTN OVER SOUTHEAST WYOMING. CAPE IS RATHER MEAGER...SO MAIN THREATS WILL BE BRIEF HEAVY RAIN AND GUSTY WINDS. KEPT SLIGHT CHANCE POPS OUT OF THE PANHANDLE AS THE MODELS INDICATE CONVECTION STRUGGLING AS IT PROGRESSES TO THE NORTHEAST. TEMPS TODAY WILL BE AROUND 10 DEGREES WARMER THAN YESTERDAY WITH MORE SUNSHINE AND 700 MB TEMPS INCREASING TO 14C. MORE WARMING WITH OCCUR THURSDAY ALONG WITH SUBSTANTIAL DRYING. PW VALUES DROP TO BELOW 0.5 INCH OVER MUCH OF THE CWA. CONVECTION WILL BE ISOLATED AT BEST. PRESSURE FALLS ACROSS NORTHEAST WYOMING WILL CAUSE SOUTHWEST WINDS TO INCREASE MOST NOTABLY TO THE WEST OF THE LARAMIE RANGE. GUSTS OF 30 TO 35 MPH WILL BE COMMON DURING THE AFTN OVER LOWER ELEVATIONS OF CARBON AND ALBANY COUNTIES. THE BREEZY WINDS WILL COMBINE WITH MIN RH VALUES OF 15 TO 20 PERCENT TO PRODUCE SOME ELEVATED FIRE WEATHER CONDITIONS THERE. FIRE WEATHER ZONE 304 CURRENTLY HAS FUELS READY...SO WILL HAVE TO MONITOR THIS ZONE FOR A POTENTIAL RED FLAG HIGHLIGHT. RH VALUES ARE MARGINAL RIGHT NOW THOUGH. TEMPS WILL BE QUITE WARM ON THURSDAY AS 700 MB TEMPS RISE TO AROUND 17C. BY FRIDAY...A SHORTWAVE TROUGH WILL BE MOVING ACROSS MONTANA AND NORTHERN WYOMING. THE GRADIENT DOES WEAKEN SOME OVER SOUTHEAST WYOMING AS WINDS BECOME MORE WESTERLY. CONVECTION WILL ONCE AGAIN BE ALMOST NON-EXISTENT. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 AM MDT WED JUL 22 2015 THE 00Z MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT MAINTAINING THE UPPER RIDGE OVER THE SOUTHERN HALF OF THE CONUS. THIS RIDGE BUILDS OVER THE GREAT PLAINS AS A POTENT UPPER TROUGH MOVES INTO THE PACIFIC NORTHWEST LATE IN THE WEEKEND. TSTORM COVERAGE WILL BE SCARCE DUE TO THE WARM TEMPERATURES ALOFT AND CONVECTIVE INHIBITION. THE ECMWF DEVELOPS CONVECTION OVER THE HIGH PLAINS SUNDAY AFTERNOON WHILE IT IS ALMOST NON-EXISTENT PER THE GFS. COMPROMISED WITH 15 TO 20 PERCENT POPS ALONG AND EAST OF A CHADRON TO KIMBALL LINE SUNDAY EVENING. WEEKEND TEMPERATURES WILL AVERAGE ABOVE SEASONAL NORMALS WITH HIGHS FROM 85 TO 95. THE SOUTHWEST FLOW ALOFT INCREASES EARLY NEXT WEEK AS THE TROUGH IMPACTS THE NORTHERN ROCKIES. WARM TEMPERATURES WILL CONTINUE MONDAY...COOLING SOMEWHAT IN THE WAKE OF A PACIFIC FRONT TUESDAY. DIURNAL CONVECTION MONDAY AND TUESDAY WILL BE ISOLATED AND MAINLY CONFINED TO THE SOUTHEAST WYOMING MOUNTAINS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING) ISSUED AT 1125 AM MDT WED JUL 22 2015 VFR EXPECTED OVERALL OVER THE TERMINALS THROUGH THE PERIOD. THERE WILL BE WDLY SCTD SHOWERS AND TSTRMS DEVELOPING OVER THE SE WY MTNS THIS AFTERNOON AND MOVING EAST OVER PARTS OF THE PLAINS INTO THIS EVENING BEFORE ENDING. BRIEF PDS OF GUSTY WINDS AND MVFR VSBYS IN STRONGER ACTIVITY. && .FIRE WEATHER... ISSUED AT 325 AM MDT WED JUL 22 2015 TEMPERATURES WILL INCREASE OVER THE NEXT FEW DAYS AS A DRIER AIR MASS MOVES INTO THE REGION...ESPECIALLY BY THURSDAY. THERE IS THE POTENTIAL FOR ELEVATED FIRE WEATHER CONDITIONS THURSDAY AFTERNOON OVER SOUTHEAST WYOMING. MINIMUM HUMIDITY VALUES WILL FALL TO 15 TO 20 PERCENT AND SOUTHWEST WINDS WILL OCCASIONALLY GUST TO 25 TO 30 MPH MAINLY ALONG AND WEST OF THE LARAMIE RANGE. WINDS WILL WEAKEN SOME BY FRIDAY...HOWEVER AFTERNOON HUMIDITY VALUES WILL STILL BE NEAR CRITICAL LEVELS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...GCC SHORT TERM...ZF LONG TERM...MAJ AVIATION...RE FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1041 AM MDT WED JUL 22 2015 .UPDATE... ISSUED AT 1039 AM MDT WED JUL 22 2015 LATEST HRRR SHOWING SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE SOUTH LARAMIE RANGE AND MOVING OUT INTO THE WESTERN NEBRASKA PANHANDLE THIS AFTERNOON. WENT AHEAD AND ADDED SLIGHT CHANCE POPS INTO THE PANHANDLE FOR LATE AFTERNOON. UPDATES HAVE BEEN SENT. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 325 AM MDT WED JUL 22 2015 SKIES ARE GENERALLY CLEAR OVER SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE BEHIND THE SHORTWAVE THAT MOVED OVERHEAD YESTERDAY. HEIGHTS WILL RISE THROUGH THE DAY AND THE 500MB RIDGE AXIS WILL BE LOCATED OVER SOUTHEAST WY BY THIS AFTN. CONVECTIVE COVERAGE WILL BE LESS TODAY ESPECIALLY OVER THE NEBRASKA PANHANDLE. WITH SOUTHWESTERLY 700 TO 500 MB FLOW THERE IS STILL GOOD SUBTROPICAL MOISTURE STREAMING INTO SOUTHEAST WYOMING DURING PEAK HEATING AND PW VALUES ARE 0.75 TO 1 INCH. THUS...EXPECTING ISOLATED TO SCATTERED TSTMS TO DEVELOP THIS AFTN OVER SOUTHEAST WYOMING. CAPE IS RATHER MEAGER...SO MAIN THREATS WILL BE BRIEF HEAVY RAIN AND GUSTY WINDS. KEPT SLIGHT CHANCE POPS OUT OF THE PANHANDLE AS THE MODELS INDICATE CONVECTION STRUGGLING AS IT PROGRESSES TO THE NORTHEAST. TEMPS TODAY WILL BE AROUND 10 DEGREES WARMER THAN YESTERDAY WITH MORE SUNSHINE AND 700 MB TEMPS INCREASING TO 14C. MORE WARMING WITH OCCUR THURSDAY ALONG WITH SUBSTANTIAL DRYING. PW VALUES DROP TO BELOW 0.5 INCH OVER MUCH OF THE CWA. CONVECTION WILL BE ISOLATED AT BEST. PRESSURE FALLS ACROSS NORTHEAST WYOMING WILL CAUSE SOUTHWEST WINDS TO INCREASE MOST NOTABLY TO THE WEST OF THE LARAMIE RANGE. GUSTS OF 30 TO 35 MPH WILL BE COMMON DURING THE AFTN OVER LOWER ELEVATIONS OF CARBON AND ALBANY COUNTIES. THE BREEZY WINDS WILL COMBINE WITH MIN RH VALUES OF 15 TO 20 PERCENT TO PRODUCE SOME ELEVATED FIRE WEATHER CONDITIONS THERE. FIRE WEATHER ZONE 304 CURRENTLY HAS FUELS READY...SO WILL HAVE TO MONITOR THIS ZONE FOR A POTENTIAL RED FLAG HIGHLIGHT. RH VALUES ARE MARGINAL RIGHT NOW THOUGH. TEMPS WILL BE QUITE WARM ON THURSDAY AS 700 MB TEMPS RISE TO AROUND 17C. BY FRIDAY...A SHORTWAVE TROUGH WILL BE MOVING ACROSS MONTANA AND NORTHERN WYOMING. THE GRADIENT DOES WEAKEN SOME OVER SOUTHEAST WYOMING AS WINDS BECOME MORE WESTERLY. CONVECTION WILL ONCE AGAIN BE ALMOST NON-EXISTENT. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 325 AM MDT WED JUL 22 2015 THE 00Z MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT MAINTAINING THE UPPER RIDGE OVER THE SOUTHERN HALF OF THE CONUS. THIS RIDGE BUILDS OVER THE GREAT PLAINS AS A POTENT UPPER TROUGH MOVES INTO THE PACIFIC NORTHWEST LATE IN THE WEEKEND. TSTORM COVERAGE WILL BE SCARCE DUE TO THE WARM TEMPERATURES ALOFT AND CONVECTIVE INHIBITION. THE ECMWF DEVELOPS CONVECTION OVER THE HIGH PLAINS SUNDAY AFTERNOON WHILE IT IS ALMOST NON-EXISTENT PER THE GFS. COMPROMISED WITH 15 TO 20 PERCENT POPS ALONG AND EAST OF A CHADRON TO KIMBALL LINE SUNDAY EVENING. WEEKEND TEMPERATURES WILL AVERAGE ABOVE SEASONAL NORMALS WITH HIGHS FROM 85 TO 95. THE SOUTHWEST FLOW ALOFT INCREASES EARLY NEXT WEEK AS THE TROUGH IMPACTS THE NORTHERN ROCKIES. WARM TEMPERATURES WILL CONTINUE MONDAY...COOLING SOMEWHAT IN THE WAKE OF A PACIFIC FRONT TUESDAY. DIURNAL CONVECTION MONDAY AND TUESDAY WILL BE ISOLATED AND MAINLY CONFINED TO THE SOUTHEAST WYOMING MOUNTAINS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 325 AM MDT WED JUL 22 2015 PATCHY MVFR TO IFR CIGS AND VSBYS WILL BE POSSIBLE ALONG THE CYS TO SNY ROUTE EARLY THIS MORNING PER THE LATEST HRRR/SREF. OTHERWISE... VFR CONDITIONS WILL PREVAIL TODAY WITH LOCALIZED MVFR VSBY POSSIBLE IN THE VICINITY OF SCATTERED AFTERNOON CONVECTION MAINLY ALONG THE RWL TO CYS ROUTE. GUSTY/ERRATIC WINDS AND LIGHTNING WILL BE THE MAIN HAZARDS. THE CONVECTION WILL BE DIMINISH EARLY THIS EVENING. && .FIRE WEATHER... ISSUED AT 325 AM MDT WED JUL 22 2015 TEMPERATURES WILL INCREASE OVER THE NEXT FEW DAYS AS A DRIER AIR MASS MOVES INTO THE REGION...ESPECIALLY BY THURSDAY. THERE IS THE POTENTIAL FOR ELEVATED FIRE WEATHER CONDITIONS THURSDAY AFTERNOON OVER SOUTHEAST WYOMING. MINIMUM HUMIDITY VALUES WILL FALL TO 15 TO 20 PERCENT AND SOUTHWEST WINDS WILL OCCASIONALLY GUST TO 25 TO 30 MPH MAINLY ALONG AND WEST OF THE LARAMIE RANGE. WINDS WILL WEAKEN SOME BY FRIDAY...HOWEVER AFTERNOON HUMIDITY VALUES WILL STILL BE NEAR CRITICAL LEVELS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...GCC SHORT TERM...ZF LONG TERM...MAJ AVIATION...MAJ FIRE WEATHER...ZF