Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/29/15


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
221 PM MST MON JUL 27 2015 .SYNOPSIS... DRY WESTERLY FLOW ALOFT WILL KEEP SHOWERS AND THUNDERSTORM CHANCES NEAR-ZERO ACROSS THE REGION TODAY. INCREASING SOUTHERLY FLOW ALOFT WILL GRADUALLY INCREASE MOISTURE LEVELS...AND THUNDERSTORM CHANCES FROM TUESDAY ONWARD THROUGH THURSDAY. HIGH PRESSURE BUILDING OVER THE REGION WILL THEN REDUCE STORM CHANCES SOMEWHAT THROUGH INTO THE WEEKEND. && .DISCUSSION... MOSTLY CLEAR SKIES ARE EVIDENT ON THE VISIBLE SATELLITE PHOTO TODAY ACROSS OUR REGION. SOME VERY THIN CIRRUS IS MOVING NERD OVER PINAL AND GILA COUNTIES AND JUST A BIT OF BUILDING CU OVER SRN GILA COUNTY AS WELL AS FURTHER EAST AND SOUTH. WATER VAPOR IMAGERY CONTINUES TO SHOW THE SERN THIRD OF ARIZONA MOIST LAYER ALOFT...SIMILAR TO WHAT WE HAVE SEEN OVER THE PAST SEVERAL DAYS. SOME TSTM ACTIVITY IS EVIDENT SOUTH OF THE BORDER IN NOGALES STATE AS WELL AS SOME LOW GRADE TSTM ACTIVITY IN PIMA AND COCHISE COUNTIES. DEW POINTS ARE MUCH HIGHER THAN YESTERDAY WITH MOST VALUES IN THE 50S...ABOUT 15 TO 20 DEGREES HIGHER. TEMPERATURES ONCE AGAIN REMAINING NEAR NORMAL LEVELS FOR TODAY. HIGH PRESSURE CONTINUES TO BE CENTERED OVER TEXAS...THIS HAS BEEN A PERSISTENT FEATURE FOR SEVERAL DAYS. A STRONG TROUGH IS ALIGNED OVER THE NORTHWEST...ALONG ERN WA AND OR. AN UPPER LEVEL LOW PRESSURE CELL IS CENTERED OVER SRN BAJA CA. THE TX HIGH AND BAJA LOW ARE HELPING TRANSPORT MOISTURE UP INTO AZ AND NM. GFS MODEL INDICATING A STRENGTHENING OF THE MOISTURE TRANSPORT FOR THE NEXT FEW DAYS...THUS SIGNALLING A RETURN OF THE SOUTHWEST MONSOON FOR ARIZONA...AND LIKELY SRN CA AS WELL. INDEED GFS MODEL SOUNDING PREDICTS STRONG RISE IN PWATS...GOING FROM ABOUT 0.8 IN NOW UP TO 1.8 BY THURSDAY WITH A SATURATED PROFILE AT MID AND UPR LEVELS. HRRR AND OUR WRF4KM SHOW A MARKED INCREASE IN CONVECTION BEGINNING TUESDAY AND CONTINUING THROUGH AT LEAST THURSDAY. TUESDAY ACTIVITY MORE LIKELY TO REMAIN MOSTLY SOUTH AND SOUTHEAST OF OUR AREA...BUT THAT OFTEN BRINGS WITH IT A GOOD CHANCE FOR BLOWING DUST AND MAYBE EVEN DUST STORMS IN LATE AFTN AND EARLY EVENING. THE WRF FOR WEDNESDAY EVEN BRINGS A STRONG OUTFLOW BOUNDARY THROUGH...GENERATED FROM EXTENSIVE CONVECTION PREDICTED FROM PIMA COUNTY STORMS. CLEARLY WE WILL HAVE AN ACTIVE MONSOON PERIOD BEGINNING TUESDAY WITH ACTIVE THUNDERSTORMS AND POTENTIAL FOR DUST STORMS. AN AREA OF BLOWING DUST WAS ADDED TO OUR GRIDS FOR TUESDAY AND WEDNESDAY. BEYOND FRIDAY...WE WILL RETAIN ENOUGH MONSOON MOISTURE TO KEEP UP SOME ACTIVITY ALTHOUGH IT DOES NOT APPEAR TO BE AS STRONG AS THE TUESDAY THROUGH EARLY FRIDAY PERIOD. TEMPERATURES WILL REMAIN NEAR OR JUST BELOW NORMAL LEVELS THROUGHOUT THE PERIOD. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... MOSTLY CLEAR SKIES THROUGH MUCH OF THE PERIOD WITH SOME FEW CU NEAR 12K FEET THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL FOLLOW DIURNAL PATTERNS...BUT STILL EXPECTING A LATE SHIFT TO UPSLOPE EASTERLIES TONIGHT. AFTERNOON OCCASIONAL WIND GUSTS TO AROUND 15 KTS ALSO LIKELY. MONSOON ACTIVITY WILL INCREASE STARTING LATER ON TUESDAY...BUT THERE IS ONLY SLIGHT POTENTIAL FOR ANY THUNDERSTORM OUTFLOWS REACHING INTO THE DESERTS TUESDAY EVENING. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... A FAIRLY PERSISTENT SOUTH SOUTHWESTERLY WIND EXPECTED INTO TUESDAY WITH OCCASIONAL AFTERNOON AND EARLY EVENING BREEZINESS AT KBLH. SKIES WILL REMAIN CLEAR TO MOSTLY CLEAR THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... THURSDAY THROUGH MONDAY... WIDESPREAD MOISTURE WILL ENCOMPASS MUCH OF THE REGION LATE IN THE WEEK BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING HOURS WITH BEST CHANCES ACROSS HIGHER TERRAIN AREAS. A SUBTLE SHIFT IN THE MID LEVEL WIND FLOW SHOULD LEAD TO SOME DRYING FOR FRIDAY INTO THE WEEKEND ALONG WITH SLIGHTLY LOWER RAIN CHANCES. TEMPERATURES THROUGH THE PERIOD WILL REMAIN NEAR NORMALS WHILE MINIMUM AFTERNOON HUMIDITIES WILL GENERALLY FALL INTO A 20-30 PERCENT RANGE OVER THE DESERTS EACH DAY. WINDS WILL REMAIN FAIRLY LIGHT EACH DAY ASIDE FROM AFTERNOON BREEZINESS AND POTENTIAL FOR STRONGER THUNDERSTORM OUTFLOW WINDS.&& .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...WATERS AVIATION...KUHLMAN FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS RENO NV
212 PM PDT MON JUL 27 2015 .SYNOPSIS... CLEAR SKIES AND LIGHT NORTHEAST WINDS WILL CONTINUE THROUGH TUESDAY AS LOW PRESSURE MOVES AWAY INTO THE NORTHERN ROCKIES. WILDFIRES ON THE WEST SLOPES MAY PRODUCE PERIODS OF HAZE ALONG THE SIERRA CREST. HIGH PRESSURE BUILDING OVER THE DESERT SOUTHWEST LATE WEEK WILL TRANSPORT MOISTURE UP INTO THE REGION STARTING THURSDAY, WITH DAILY CHANCES FOR THUNDERSTORMS THROUGH THE UPCOMING WEEKEND. && .SHORT TERM... NEXT COUPLE DAYS WILL BE CLEAR AND DRY IN THE WAKE OF LAST NIGHTS COLD FRONTAL PASSAGE. 700MB TEMPS ACROSS NORTHERN NV ARE FAIRLY COOL FOR THIS TIME OF YEAR. GIVEN LOW PW VALUES (1-2.5 PERCENTILE) WE SHOULD SEE APPRECIABLE DIURNAL TEMPERATURE SWINGS AGAIN TONIGHT AND TOMORROW. HIGH PRESSURE BEGINNING TO BUILD OVER THE DESERT SOUTHWEST WILL PROMPT A WARMING TREND WHICH WILL CONTINUE INTO THE UPCOMING WEEKEND. THICKER SMOKE FROM THE WEST SLOPE WILDFIRES SHOULD LARGELY REMAIN OUT OF THE EASTERN SIERRA AND WESTERN NEVADA THROUGH WEDNESDAY WITH E/NE FLOW IN THE BOUNDARY LAYER. I WILL CONTINUE A MENTION OF HAZE RIGHT ALONG THE CREST THIS AFTERNOON AND AGAIN TOMORROW AFTERNOON AS HRRR GUIDANCE SHOWS SURFACE WESTERLIES SNEAKING IN, EXTENDING TO ABOUT 5-10 MILES EAST OF THE CREST. CS .LONG TERM...THURSDAY THROUGH MONDAY... HIGH PRESSURE WILL BE CENTERED OVER THE FOUR CORNERS REGION BY THURSDAY WITH A WEAK LOW DEVELOPING IN THE EASTERN PACIFIC THIS WEEKEND. THIS WILL BRING ABOVE AVERAGE TEMPERATURES FOR THE END OF THE WEEK AND INCREASING CHANCES FOR THUNDERSTORMS THROUGH THE WEEKEND AND INTO NEXT WEEK. BY THURSDAY TEMPERATURES IN WESTERN NEVADA WILL BE NEAR THE 100 DEGREE MARK AND STAY IN THE UPPER 90`S UNTIL THE COOLING AFFECTS OF THUNDERSTORMS BEGIN TO MODERATE THE TEMPERATURE OVER THE WEEKEND. THIS IS CLIMATOLOGICALLY THE HOTTEST TIME OF THE YEAR FOR WESTERN NEVADA AND TEMPERATURES WILL BE RUNNING AROUND 4-6 DEGREES ABOVE AVERAGE. THE MORE IMPACTFUL PART OF THE FORECAST WILL LIKELY BE THE RETURN OF ANOTHER THUNDERSTORM PATTERN AS WE MOVE INTO THE WEEKEND. INSTABILITY LOOKS LESS IMPRESSIVE FOR THURSDAY AND FRIDAY, BUT A FEW ISOLATED STORMS WILL REMAIN POSSIBLE ALONG THE SIERRA CREST, MAINLY SOUTH OF LAKE TAHOE. AS WE GO INTO THE WEEKEND, AND INTO THE BEGINNING OF NEXT WEEK, THUNDERSTORMS WILL BECOME MORE WIDESPREAD. DETAILS OF THE THUNDERSTORM PATTERN ARE STILL COMING INTO FOCUS, BUT IF YOU HAVE OUTDOOR PLANS THIS WEEKEND IN THE SIERRA OR WESTERN NEVADA KEEP AN EYE ON THE FORECAST AND MAKE A PLAN FOR THUNDERSTORMS. TOLBY && .AVIATION... VFR WITH LIGHT WINDS THROUGH WEDNESDAY. SURFACE WINDS TODAY GENERALLY NNE BECOMING EAST ON TUESDAY. TOLBY && .REV WATCHES/WARNINGS/ADVISORIES... NV...NONE. CA...NONE. && $$ FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1039 PM MDT SUN JUL 26 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 325 PM MDT SUN JUL 26 2015 MOISTURE WORKING AROUND HIGH PRESSURE CENTERED OVER THE TEXAS PANHANDLE THIS AFTERNOON AND WEAK WAVES EMBEDDED IN THE FLOW WILL KEEP SHOWERS IN THE FORECAST THROUGH LATE TONIGHT...MAINLY SOUTH OF INTERSTATE 70. THIS ACTIVITY SENDING SOME ENHANCED DRAINAGE/OUTFLOW WINDS NORTHWARD ACROSS THE CENTRAL VALLEYS WHERE WINDS HAVE BEEN GUSTING OVER 30 MPH FOR A FEW HOURS. THE GUSTY NATURE TO THE WINDS WILL RELAX THIS EVENING...BUT RETURN IN FORCE BY MIDDAY MONDAY AS A DRY FRONT WORKS SOUTHEAST INTO THE REGION. THIS WILL RESULT IN CRITICAL FIRE WEATHER CONDITIONS FOR PORTIONS OF NORTHWEST AND WEST CENTRAL COLORADO...DISCUSSED IN MORE DETAIL BELOW. THE DEEPER MOISTURE PLUME WILL BE SHIFTING SOUTH AND EAST AS THE DRY FRONT WORKS IN...SENDING THE BEST CHANCE FOR ANY PRECIPITATION ALONG WITH IT. ANY LINGERING MOISTURE ON MONDAY WILL BE CONFINED TO THE HIGHER TERRAIN...WITH THE FOCUS OVER AND ALONG THE CONTINENTAL DIVIDE FROM CENTRAL TO SOUTHWEST COLORADO...WHERE THE NAM12 AND RAP HOLDING ON TO DEEPER MOISTURE A BIT LONGER. SFC MOISTURE ALSO DEPARTS WITH DAYTIME HUMIDITIES FALLING INTO THE SINGLE DIGITS AND TEENS IN MANY AREAS. TEMPS WILL BE UP SLIGHTLY IN MANY AREAS...WITH MOS NUMBERS IN THE BALLPARK. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 325 PM MDT SUN JUL 26 2015 ENERGETIC NORTHERN ROCKIES LOW WILL BE LIFTING ENE INTO SOUTHERN CANADA TUESDAY...DRIVING THE ABOVE MENTIONED DRY FRONT ACROSS THE FORECAST AREA...WITH DRIER WESTERLY FLOW SETTING UP FOR A COUPLE DAYS. THE RIDGE STARTS REBUILDING TO THE WEST BY LATE IN THE WEEK WITH HEIGHTS CLIMBING TO OUR WEST. THIS WILL ALLOW SOME MOISTURE TO WORK BACK NORTH...BUT CENTER OF THE RIDGE WILL BE TO OUR WEST AND IT WILL TAKE SOME TIME FOR THE MOISTURE TO FILL BACK INTO OUR REGION. THE RIDGE STRENGTHENS AND RECENTERS OVER WESTERN COLORADO BY THE WEEKEND WHICH WILL FINALLY ALLOW SOME MOISTURE TO WORK BACK INTO EASTERN UTAH AND EVENTUALLY ACROSS WESTERN COLORADO BY EARLY NEXT WEEK AS THE RIDGE SLIDES EAST OF THE FORECAST AREA...SENDING THE DEEP SOUTHERLY FETCH BACK IN. TEMPS WILL BE RUNNING ON THE NEAR NORMAL TO START OFF THE PERIOD...BUT SHOULD AVERAGE 4 TO 8 DEGREES ABOVE NORMAL FOR THE THURSDAY THROUGH SUNDAY TIME PERIOD WITH THE RIDGE MOVING DIRECTLY OVERHEAD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1035 PM MDT SUN JUL 26 2015 PASSING MID LEVEL CLOUDINESS COULD PRODUCE SOME VIRGA/SPRINKLES AND GUSTY WINDS BUT VFR CONDITIONS WILL PREVAIL AT VFR LEVELS OVERNIGHT. LOW LEVEL WIND SHEAR MAY DEVELOP 09Z-15Z WITH WINDS AT 10000-14000 FT MSL INCREASING 40KTS FROM THE SW AFT 12Z. THESE GUSTY SW WINDS WILL MIX INTO TAF SITES BETWEEN 15-18Z MONDAY. ISOLATED STORMS AND SHOWERS CONTINUE THROUGH MONDAY MAINLY NEAR THE CONTINENTAL DIVIDE. && .FIRE WEATHER... ISSUED AT 815 PM MDT SUN JUL 26 2015 THE RED FLAG WARNING FOR TODAY HAS EXPIRED AT 8PM.... TIGHTENING SFC GRADIENT AHEAD OF DRY COLD FRONT PUSHING INTO THE REGION WILL BRING INCREASINGLY GUSTY SOUTHWEST WINDS OVER THE NEXT 24 TO 30 HOURS. WITH FUELS AT CRITICAL LEVELS BASED ON LATEST INPUT FROM PARTNERS...EXPECTED HUMIDITY BELOW 15 PERCENT AND WINDS GUSTING OVER 25 MPH MONDAY AFTERNOON...WILL BE UPGRADING THE FIRE WEATHER WATCH FOR PORTIONS OF NORTHWEST AND WEST CENTRAL COLORADO...INCLUDING FIRE WEATHER ZONES 200...201...202 AND 203. THE GUSTY NATURE TO THE WINDS ARE EXPECTED TO DIMINISH BY SUNSET MONDAY EVENING. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...RED FLAG WARNING FROM 11 AM TO 8 PM MDT MONDAY FOR COZ200>203. UT...NONE. && $$ SHORT TERM...JDC LONG TERM...JDC AVIATION...TGJT FIRE WEATHER...MPM
AREA FORECAST DISCUSSION
NWS ALBANY NY
434 PM EDT MON JUL 27 2015 .SYNOPSIS... HOT AND HUMID WEATHER IS EXPECTED FOR MOST OF THE UPCOMING WORK WEEK AS A RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT BUILDS OVER THE REGION. WITH THE WARM...MUGGY AIR IN PLACE... ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE POSSIBLE. THE WARMEST DAY OF THE WEEK WILL BE WEDNESDAY WHEN HIGHS IN VALLEY AREAS WILL REACH WELL INTO THE 90S. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 434 PM...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE OVER THE SOUTHERN ADIRONDACKS...CATSKILLS...MID HUDSON VALLEY...CENTRAL BERKSHIRE COUNTY...SOUTHWESTERN LITCHFIELD COUNTY CONNECTICUT AND FAR SOUTHERN WINDHAM COUNTY IN VERMONT. CELL MOVEMENT HAS GENERALLY BEEN TO THE SOUTHEAST AT 5-10 MPH. TEMPERATURES RANGE FROM THE 70S WHERE RAIN HAS FALLEN TO THE UPPER 80S IN MANY VALLEY LOCATIONS. SURFACE WINDS ARE LIGHT AND VARIABLE. EXPECT STORMS TO CONTINUE THROUGH ABOUT SUNSET AND THEN THEY SHOULD WEAKEN AND DISSIPATE. LATEST HRRR HAS MOST OF THE ACTIVITY OVER BY 01Z WITH THE LAST ECHO DISSIPATING BEFORE MIDNIGHT. && .SHORT TERM /8 PM THIS EVENING THROUGH WEDNESDAY NIGHT/... HEAT WILL BE THE STORY THIS WEEK. A RIDGE BUILDING IN AT THE SURFACE AND ALOFT WILL PROVIDE FOR MAINLY DRY WEATHER THROUGH WEDNESDAY. A WEAK BACKDOOR FRONT MAY CAUSE SOME THUNDERSTORMS ON TUESDAY OVER THE SOUTHERN ADIRONDACKS...LAKE GEORGE REGION AND SOUTHERN VERMONT. THERE WILL BE LESS CHANCE FOR SHOWERS AND STORMS ON WEDNESDAY...BUT WITH THE WARM AND HUMID AIRMASS IN PLACE...AN ISOLATED THUNDERSTORM OR TWO OVER THE HIGHER TERRAIN IS POSSIBLE. LOW TEMPERATURES WILL GENERALLY BE IN THE 60S WITH SOME 50S TONIGHT IN THE NORMALLY COOLER LOCATIONS. ON WEDNESDAY MORNING...LOWS MAY NOT GO BELOW 70 IN THE NORMALLY WARMER LOCATIONS. && .LONG TERM /THURSDAY THROUGH MONDAY/... ROUNDING OUT THE MONTH OF JULY AND HEADING INTO AUGUST...THE LONG TERM PERIOD WILL CONTINUE WITH WARM...BUT SEASONABLE TEMPERATURES AND DECREASING HUMIDITY LEVELS...ALONG WITH CHANCES FOR PRECIPITATION ACROSS THE REGION THURSDAY AND AGAIN HEADING INTO EARLY NEXT WEEK. AT THE START OF THE LONG TERM PERIOD...THE REGION WILL BE IN THE WARM SECTOR AHEAD OF AN APPROACHING COLD FRONT THAT WILL CROSS THE FORECAST AREA DURING THE DAY. SCATTERED THUNDERSTORMS LOOK LIKELY AHEAD OF THE FRONT BUT THERE ARE STILL SOME QUESTIONS AS TO HOW STRONG THE STORMS WILL BE AS THERE SHOULD BE PLENTY OF INSTABILITY...BUT SHEAR AND MIDLEVEL LAPSE RATES LOOK MARGINAL AT BEST. REGARDLESS...HAVE GONE WITH CHANCE POPS FOR SCATTERED THUNDERSTORMS WITH A FEW CELLS THAT COULD BECOME LOCALLY STRONG TO PERHAPS SEVERE...WITH HEAVY RAIN ALSO BEING A THREAT. THE COLD FRONT SHOULD EXIT THE REGION THURSDAY EVENING INTO THURSDAY NIGHT...WITH LINGERING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS MAINLY ACROSS WESTERN NEW ENGLAND EARLY THURSDAY NIGHT. BEHIND THE COLD FRONT...HIGH PRESSURE WILL RAPIDLY BUILD ACROSS THE REGION FROM WEST TO EAST ALONG WITH GRADUALLY CLEARING SKIES AND DRY WEATHER. FRIDAY LOOKS TO BE A NICE...BUT WARM DAY WITH DRY WEATHER AND LOWER HUMIDITY LEVELS AS SLIGHTLY DRIER AIR...DEWPOINTS DROPPING INTO THE 50S...ARE USHERED INTO THE REGION WITH THE HIGH PRESSURE. THIS AREA OF HIGH PRESSURE WILL CONTINUE TO HAVE AN INFLUENCE ACROSS THE REGION FRIDAY NIGHT THROUGH MOST OF THE WEEKEND...AS PIECES OF SHORTWAVE ENERGY ROTATE THROUGH A BROAD UPPER-LEVEL TROUGH ALOFT. THESE PIECES OF ENERGY WILL PROMOTE DIURNALLY-DRIVEN ISOLATED SHOWERS/THUNDERSTORMS MAINLY ACROSS THE HIGHER TERRAIN OF THE SOUTHERN ADIRONDACKS AND SOUTHERN VERMONT. THE NEXT BEST CHANCE FOR PRECIPITATION...SCATTERED SHOWERS AND THUNDERSTORMS...LOOKS TO OCCUR EARLY NEXT WEEK AS A FRONTAL BOUNDARY APPROACHES THE REGION FROM THE WEST. HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY RANGE FROM UPPER 70S ACROSS THE SOUTHERN ADIRONDACKS/HIGH PEAKS OF SOUTHERN VERMONT...TO MID AND UPPER 80S ACROSS THE REST OF THE REGION...WITH SOME LOCATIONS IN FAVORED DOWNSLOPE AREAS IN THE MID- HUDSON VALLEY REACHING 90. LOW TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY RANGE FROM THE UPPER 50S TO MID 60S. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... A WARM AND HUMID AIR MASS WILL CONTINUE TO BECOME ESTABLISHED ACROSS THE REGION TODAY. ISOLATED SHOWERS AND THUNDERSTORMS ARE DEVELOPING AROUND HIGHER TERRAIN BUT AT THIS TIME LOOK TO BE STAYING AWAY FROM THE TAF SITES. THE SHOWERS AND THUNDERSTORMS ARE SLOW MOVING...SO UNLESS ONE SHOWER OR THUNDERSTORM DEVELOPS VERY CLOSE TO A TAF SITE...THE RAIN IS NOT EXPECTED TO AFFECT THE TAF SITES THROUGH THIS EVENING. ACKNOWLEDGING A VCSH FOR KPSF AND KPOU WHERE THERE IS A SLIGHTLY BETTER CHANCE OF A SHOWER OR THUNDERSTORM NEARBY THROUGH THIS EVENING. ANY SHOWER OR THUNDERSTORM ACTIVITY THIS EVENING WILL END AFTER SUNSET AND WITH INCREASING HUMIDITY AND LIGHT WINDS...SOME FOG AND LOW CLOUDS COULD ONCE AGAIN DEVELOP AFTER MIDNIGHT. INDICATING IFR CEILINGS AND VISIBILITIES AT KPSF AND KGFL...WITH MVFR AT KPOU AND KALB. AFTER 13Z-14Z...RETURN TO VFR. WINDS WILL BE LIGHT SOUTH TO WEST AT 6 KT OR LESS THIS AFTERNOON...THEN NEAR CALM TONIGHT AND VARIABLE AT 6 KT PR LESS TOMORROW. OUTLOOK... TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA. THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX. FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... HOT AND HUMID WEATHER IS EXPECTED FOR MOST OF THE UPCOMING WORK WEEK AS A RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT BUILDS OVER THE REGION. WITH THE WARM...MUGGY AIR IN PLACE... ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE POSSIBLE. THE WARMEST DAY OF THE WEEK WILL BE WEDNESDAY WHEN HIGHS IN VALLEY AREAS WILL REACH WELL INTO THE 90S. RELATIVE HUMIDITY WILL INCREASE TO 80 TO 100 PERCENT AROUND SUNRISE TUESDAY AND WEDNESDAY MORNING AND FALL TO 40 TO 60 PERCENT TUESDAY AFTERNOON. TONIGHT WINDS WILL BE LIGHT AND VARIABLE. WINDS WILL BE BE FROM THE WEST OR NORTHWEST TUESDAY AFTERNOON AT 5-10 MPH. WINDS WILL BECOME LIGHT AND VARIABLE AGAIN ON TUESDAY NIGHT. && .HYDROLOGY... NO LARGER RIVER FLOODING IS FORECAST THROUGH THE NEXT 5 DAYS. LOCALIZED HEAVY RAIN FROM THUNDERSTORMS MAY CAUSE PONDING OF WATER ON ROADWAYS AND POOR DRAINAGE FLOODING OF LOW LYING AREAS. 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. && .CLIMATE... CONDITIONS WILL BECOME HOT AND HUMID THIS WEEK WITH HIGHS FORECAST TO BE IN THE 90S UP THE HUDSON RIVER VALLEY TUESDAY...WEDNESDAY AND THURSDAY. HERE ARE THE RECORD HIGH TEMPERATURES AND YEAR OF OCCURRENCE FOR THESE DATES... JULY 28TH... ALBANY NY: 99 DEGREES 1929 GLENS FALLS: 96 DEGREES 1949 POUGHKEEPSIE NY: 96 DEGREES 1949 JULY 29TH... ALBANY NY: 97 DEGREES 1894 GLENS FALLS: 96 DEGREES 1959 POUGHKEEPSIE NY: 95 DEGREES 1949 JULY 30TH... ALBANY NY: 100 DEGREES 1933 GLENS FALLS: 94 DEGREES 1949 POUGHKEEPSIE NY: 96 DEGREES 1949 NOTE THE DAILY RECORDS DATE BACK TO 1874 AT ALBANY NY AND TO 1949 FOR BOTH GLENS FALLS AND POUGHKEEPSIE NY. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...SND/GJM NEAR TERM...SND SHORT TERM...SND/GJM LONG TERM...IRL AVIATION...NAS FIRE WEATHER...HWJIV HYDROLOGY...SND/GJM CLIMATE...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
301 PM EDT MON JUL 27 2015 DISCUSSION... CURRENT...RUC SURFACE ANALYSIS ALONG WITH THE LATEST RADAR LOOP...VISIBLE SATELLITE IMAGES AND BUOY OBSERVATIONS ARE SHOWING A SMALL LOW SPINNING IN THE NORTHEAST GULF WEST OF HERNANDO AND PASCO COUNTIES. RADAR MOSIAC LOOP SHOWING COVERAGE OF SHOWERS QUICKLY FILLING IN ACROSS EAST CENTRAL FLORIDA. SOME OF THE LOCAL MESONET SITES RECORDING GUSTS OVER 30 MPH IN THE BRIEF FASTER MOVING HEAVIER SHOWERS. THE VERTICAL WIND PROFILERS IN/AROUND THE KENNEDY SPACE CENTER WERE DETECTING SOUTH TO SOUTHWEST WINDS 15 TO 20 KNOTS FROM JUST OFF THE DECK TO AROUND 8000 FEET. JUST IN...A 15Z/11AM SOUNDING FROM CAPE CANAVERAL. THE MANDATORY LEVEL WINDS STRONGER...5 TO 10 KNOTS...THAN THE 12Z/8AM SOUNDING. THIS TRANSLATES TO FASTER STORM/SHOWER MOTION THAN IN PAST DAYS. DAYTIME HEATING COMBINED WITH THE MID LEVEL DISTURBANCES IMPULSES MOVING SOUTHWEST TO NORTHEAST OVER FLORIDA AND THE HIGH PRECIPITABLE WATER CONTENT OF THE ATMOSPHERE WILL KEEP RAIN CHANCES HIGHER THAN THEIR CLIMO 40-50 PERCENT FOR THE AFTERNOON. THE TEMPERATURES ALOFT ARE STILL WARM ALOFT/500MB AT -4C AND -5C. THIS WOULD SUGGEST NOT VERY STEEP MID LEVEL LAPSE RATE THAT WOULD BE MORE CONDUCIVE TO SHOWERS THAN STORMS FOR THE AFTERNOON. WILL LOOK AT A PRE FIRST PERIOD TO CATCH THE LATE AFTERNOON AND BEFORE SUNSET WEATHER. TONIGHT...BOTH THE HRRR AND LOCAL WRFARW3 SHORT TERM MODELS FORECAST THAT THE SHOWERS AND STORMS SHOULD END AROUND SUNSET WHICH IS BETWEEN 815PM AND 820PM THIS EVENING. WILL MOST LIKELY EXTEND SHOWER ACTIVITY UNTIL AROUND 10PM/02Z WHICH AGREES WITH HOURLY RADAR IMAGES FROM LAST NIGHT. TUE...NUMEROUS TO WIDESPREAD SHOWERS WITH A MAYBE STORM IN THE AFTERNOON. WARM TEMPERATURES ALOFT...-5C AT 500 ...AGAIN WOULD SUGGEST MORE SHOWERS/RAIN THAN STORMS BECAUSE OF THE MID LEVEL LAPSE RATES NOT BEING VERY STEEP AND PRECIPITABLE WATER VALUES FORECAST TO BE EVEN HIGHER...OVER 2.25 INCHES...THAN PREVIOUS DAYS. THE ONLY PROBLEM WOULD BE THE GFS MAV MOS WIDE SPREAD OF POP...FROM AROUND 80 NORTH TO 15 TO 20 IN MARTIN COUNTY. MAKES SENSE IF THE STALLED FRONTAL BOUNDARY BECOMES "UNSTALLED" A LITTLE AND LIFTS NORTH. PREVIOUS AFD TUE NIGHT-WED NIGHT...WEAK SURFACE TROUGH/LOW WILL BE NORTH OF THE AREA BUT DEEP MOISTURE WILL LINGER ESPECIALLY TUE NIGH. MOS POPS RANGE FROM 70 PERCENT IN THE NORTH TO 40 PERCENT IN THE FAR SOUTH ON TUE. WILL FOLLOW CLOSE TO THOSE NUMBERS EXCEPT KEEP THE SOUTH AT 50 PERCENT SINCE THE GFS GENERATES CONSIDERABLE PRECIP ACROSS MOST OF THE AREA. MOS POPS DROP OFF CONSIDERABLY ON WED TO 30-40 PERCENT... BUT CONSENSUS NUMBERS REMAIN HIGHER AND CLOSER TO PREVIOUS FORECAST. THE GFS DOES NOT BRING MUCH...IF ANY...DRYING UP FROM THE SOUTH SO WILL GO CLOSE TO THE CONSENSUS NUMBERS...50-60 PERCENT. THU-WEEKEND...WEAKNESS IN SUBTROPICAL RIDGE VICINITY OF FLORIDA IS FORECAST TO MIGRATE ONLY SLOWLY WEST INTO THE GULF OF MEXICO. THIS WILL ALLOW DEEP LAYER RIDGE TO BUILD BACK INTO THE FLORIDA PENINSULA BY THE WEEKEND...CAUSING SOUTHWEST FLOW TO BECOME SOUTH OR EVEN SOUTH/SOUTHEAST ACROSS SOUTHERN SECTIONS. BAND OF DEEPEST MOISTURE...ASSOCIATED WITH SURFACE TROUGH/WEAK LOW...SHOULD ALSO CONTINUE TO MIGRATE WEST. HOWEVER...WITH STEERING FLOW MAINLY OUT OF THE SOUTHWEST AND MOISTURE NEAR TO A LITTLE ABOVE NORMAL...WILL PLAN ON THE SCATTERED POPS (30-50 PERCENT) SHOWN BY THE CONSENSUS MOS. .AVIATION...ALTHOUGH MVFR CEILING SHOWERS WILL DOMINATE THE AFTERNOON AND EARLY EVENING WEATHER...STORMS IN THE VICINITY UNTIL 8PM/00Z STILL A GOOD CALL FOR THE TAFS. THE VERTICAL WIND PROFILERS AT/AROUND THE SPACE CENTER WERE DETECTING SOUTHWEST WINDS 15 TO 20 KNOTS FROM JUST OFF THE DECK THROUGH APPROX. 8000FT. GUSTY WINDS ASSOCIATED WITH SHOWERS AND STORMS THIS AFTERNOON. MAY BE ABLE TO GET AWAY WITH 1-2 HOUR TEMPO GROUPS FOR ANY LATE AFTERNOON STORMS. BEEN NOTICING/OBSERVING LOW...IFR...STRATUS ON MY EARLY MORNING WALKS FROM AROUND 09Z TO LATE MORNING. WILL PUT SCT AT OR BELOW FL010 FROM 28/08Z TO 28/15Z AND ISSUE AMENDS AS NEEDED TUE MORNING. .MARINE...NOAA BUOY 009 AND 010 AT 20 AND 120NM OFF THE BEACH WERE RECORDING SOUTH TO SOUTHWEST WINDS AT 15 TO 20 KNOTS. THE TWO NEARSHORE SCRIPPS BUOYS AT 4 AND 6NM OF THE COAST AND BUOY 009 AT 20NM WERE RECORDING 2 TO 3 FOOT SEAS. EXPANDING THE SMALL CRAFT EXERCISE CAUTION FOR WINDS TO ALL THREE OFFSHORE MARINE ZONES. FAST MOVING SHOWERS AND ISOLATED STORMS COMING OFF THE MAINLAND WILL PRODUCE GUSTY WINDS AND BRIEF HEAVY RAIN ON THE INLAND LAKES AND RIVERS...THE INDIAN RIVER LAGOON AND AT LEAST THE NEARSHORE COASTAL WATERS OUT TO 20NM. TUE-FRI...SURFACE TROUGH NORTH OF THE WATERS AND ATLANTIC RIDGE SUPPRESSED TO THE SOUTH WILL CONTINUE TO PROVIDE A SOUTHWEST WIND FLOW. SPEEDS SHOULD BE CLOSE TO 15 KNOTS ESPECIALLY TUE NIGHT AND WED IN THE OUTER WATERS. && .PRELIMINARY POINT TEMPS/POPS... DAB 75 89 75 94 / 40 80 30 40 MCO 76 89 75 94 / 20 80 40 50 MLB 76 91 76 93 / 30 70 60 50 VRB 73 91 75 91 / 20 50 50 50 LEE 77 90 77 94 / 30 80 30 40 SFB 77 90 76 94 / 30 90 40 50 ORL 76 89 77 94 / 20 80 40 50 FPR 75 92 74 91 / 20 50 50 40 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ IMPACT WX...PENDERGRAST FORECASTS...WIMMER
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
801 PM EDT TUE JUL 28 2015 .SYNOPSIS... SUFFICIENT ATMOSPHERIC MOISTURE ALONG WITH A WEAK SURFACE TROUGH IS EXPECTED TO BRING A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGH THURSDAY. RAIN CHANCES ARE EXPECTED TO INCREASE FRIDAY INTO THE WEEKEND AS A FRONT AND ENHANCED ATMOSPHERIC MOISTURE AFFECT OUR REGION. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... SCATTERED AFTERNOON CONVECTION CONTINUES ACROSS THE WESTERN MIDLANDS EARLY THIS EVENING WITH SLOW MOVING STORMS PRODUCING NEARLY 2 INCH PER HOUR RAIN RATES AND SOME FREQUENT LIGHTNING. STORMS HAVE BEEN WEAKENING OVER THE PAST HOUR OR SO BUT THERE REMAINS SOME INSTABILITY AND MANY OUTFLOW BOUNDARIES WHICH COULD HELP SUPPORT SHOWERS INTO THE EVENING. HAVE UPDATED POPS TO ACCOUNT FOR LINGERING CONVECTION. CONVECTION SHOULD DIMINISH BY LATE EVENING AS DIURNAL HEATING ENDS. LIGHT WINDS AND HIGH LOW LEVEL MOISTURE MAY ALLOW FOR STRATUS TO DEVELOP OVERNIGHT. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... UPPER HIGH WILL REMAIN CENTERED TO OUR WEST WITH UPPER TROUGH ALONG THE EAST COAST. WEAKENING UPPER LOW AND STALLED FRONT TO REMAIN TO OUR SOUTH. AN UPPER IMPULSE OR TWO ALONG WITH A WEAK SURFACE TROUGH...SEA BREEZE...OR OTHER BOUNDARIES AND SUFFICIENT ATMOSPHERIC MOISTURE IS EXPECTED TO LEAD TO A CHANCE OF MAINLY DIURNAL CONVECTION. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MODELS CONTINUE TO INDICATE UPPER HIGH CENTER TO SHIFT WEST TO THE FOUR CORNERS REGION...WITH DEEPENING UPPER TROUGH OVER THE E CONUS...ALLOWING A FRONT TO SLOWLY SHIFT SE INTO OUR REGION FRIDAY. SOME SUBTLE DIFFERENCES BETWEEN GFS AND ECMWF. GFS APPEARS TO MOVE FRONT THROUGH FRI NT OR EARLY SATURDAY STALLING IT TO OUR SOUTH SAT INTO MON...WHILE ECWMF APPEARS TO STALL THE FRONT A LITTLE FARTHER NORTH OVER OUR FA. ENHANCED MOISTURE ASSOCIATED WITH THE STALLED FRONT TO OUR SOUTH MAY BE ABLE TO GET ENTRAINED INTO THE SYSTEM. THIS AREA WILL ALSO HAVE TO BE MONITORED FOR POSSIBLE LOW DEVELOPMENT WITH POSSIBLE IMPACTS ON OUR REGION. CONTINUED TO ACCEPT A BLEND OF GUIDANCE AND ONGOING FORECAST...LEADING TO INCREASED POPS FRIDAY WITH THE FRONT...AND INDICATING A LITTLE HIGHER POPS TO THE SOUTH SAT INTO SUN. UNCERTAINTIES LATE IN THE FORECAST PERIOD FOR EARLY NEXT WEEK. SOME QUESTIONS REGARDING POSITION AND STATUS OF FRONT AND ANY SURFACE WAVES/UPPER VORTS. MODELS SUGGEST MEAN UPPER TROUGH TO REMAIN OVERHEAD ALONG WITH INDICATIONS OF SUFFICIENT MOISTURE. SO...CHANCE POPS APPEAR OK FOR THAT TIME FRAME. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... RESTRICTIONS POSSIBLE EARLY WEDNESDAY MORNING AT ALL TAF SITES AND IN AREAS OF CONVECTIVE SHOWERS EARLY THIS EVENING. SCATTERED CONVECTION CONTINUES OVER PORTIONS OF THE MIDLANDS AND CSRA EARLY THIS EVENING. HRRR INDICATING CONVECTION WILL END LATER THIS EVENING. INCREASING LOW LEVEL MOISTURE ACROSS THE FA MAY PRODUCE MVFR/IFR CONDITIONS AT ALL TAF SITES EARLY WEDNESDAY MORNING. LIGHT WINDS FAVOR LOW STRATUS IN THE MIDLANDS AND THE EASTERN FA. THE MODELS ARE MOST PESSIMISTIC AT OGB BRINGING IN RESTRICTIONS AROUND 09Z. EXTENDED AVIATION OUTLOOK...INCREASING CHANCES OF RESTRICTIONS WEDNESDAY THROUGH SATURDAY IN MAINLY SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
719 AM EDT MON JUL 27 2015 .SYNOPSIS... THE REGION WILL REMAIN BETWEEN WEAK HIGH PRESSURE TO THE NORTH AND LOW PRESSURE TO THE SOUTH UNTIL LATE THIS WEEK. THEN...BROAD LOW PRESSURE WILL DEVELOP AND PERSIST OVER THE REGION LATE THIS WEEK THROUGH NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FOR THE SUNRISE UPDATE...LOOKS LIKE THE SOUTHWARD PROGRESSION OF THE FOG AND STRATUS HAS CEASED NOW THAT THE SUN IS COMING UP. WIDESPREAD DENSE FOG CONTINUES ACROSS MUCH OF THE DENSE FOG ADVISORY AREA. HIGH RESOLUTION MODELS HAVE BEEN INSISTENT ON DEVELOPING SHOWER/TSTMS ALONG THE SEA BREEZE THIS AFTERNOON. HAVE GONE AHEAD AN INTRODUCED A SLIGHT CHANCE POP FOR MOST AREAS ALONG THE SEA BREEZE FOR THIS AFTERNOON. TODAY...HIGH PRESSURE WILL REMAIN NOSED IN ACROSS THE EASTERN CAROLINAS TODAY AS ELONGATED LOW PRESSURE CENTERED ALONG OR JUST OFFSHORE OF THE FLORDIA WEST COAST REMAINS ANCHORED TO THE REMNANTS OF AN OLD FRONT. THE PROXIMITY OF THE SURFACE TROUGH JUST OFFSHORE COMBINED WITH COASTAL SPEED CONVERGENCE IN THE FAVORABLE NORTHEAST FETCH COULD SUPPORT ISOLATED SHOWERS IN THE HILTON HEAD TO DARIEN CORRIDOR AT JUST ABOUT ANYTIME THROUGH MID-MORNING. SLIGHT CHANCE POPS LOOK REASONABLE FOR THIS AREA THROUGH 14-15Z. THERE ARE SIGNALS THAT THE SEA BREEZE COULD BE A BIT MORE ACTIVE COMPARED TO THE PAST SEVERAL DAYS WITH HIGHER DEWPOINTS IN PLACE...BUT FORECAST SOUNDINGS STILL DEPICT A WEAKENING CAP HOLDING THROUGH THE DAY. STILL...WITH A HIGHER DEWPOINT REGIME IN PLACE AND 850-700 HPA THETA-E PROGGED TO POOL THROUGH THE DAY...WOULD NOT BE SURPRISED TO SEE AN ISOLATED/BRIEF SHOWER OR TWO POP ALONG THE SEA BREEZE THIS AFTERNOON. ANY SHOWERS THAT DO FORM WILL LIKELY BE SHORT-LIVED AND TRANSIENT. HIGHS WILL RANGE FROM THE MID 90S INLAND TO UPPER 80S- LOWER 90S AT THE COAST WITH MID 80S AT THE BEACHES. A FEW UPPER 90S COULD OCCUR ACROSS FAR INTERIOR AREAS...ROUGHLY ALONG AND NORTH OF A METTER-HAMPTON LINE...WHERE LINGERING INFLUENCES FROM THE MASSIVE MID-LEVEL ANTICYCLONE CENTERED OVER THE SOUTHERN PLAINS WILL BE THE GREATEST. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... TONIGHT...CUMULUS WILL QUICKLY DISSIPATE THIS EVENING WITH THE LOSS OF INSOLATION...BUT THE RISK FOR MARINE-BASED STRATOCUMULUS MOVING INLAND FROM OFF THE ATLANTIC WILL REMAIN FOR THE COASTAL COUNTIES. ISOLATED SHOWERS WILL REMAIN OFFSHORE DESPITE THE POTENTIAL FOR THE SURFACE TROUGH/FRONTAL REMNANTS DRAWING A BIT CLOSER TO THE COAST AS A WEAK AREA OF LOW PRESSURE DEVELOPS ALONG IT. IF THE LOW DRAWS CLOSER TO THE COAST THAN WHAT IS CURRENTLY EXPECTED...THE INTRODUCTION OF MENTIONABLE POPS AND INCREASED CLOUD COVER MAY BE NEEDED. LOW CONFIDENCE ON THE EXACT TRACK ANY LOW THAT FORMS WILL TAKE. LOWS WILL RANGE FROM THE LOWER 70S INLAND...MID 70S AT THE COAST WITH UPPER 70S AT THE BEACHES AND DOWNTOWN CHARLESTON. WHILE WE SHOULD ENTER A SLIGHTLY MORE ACTIVE CONVECTIVE REGIME DURING THIS PERIOD...AS COMPARED WITH RECENT DAYS...THE POTENTIAL FOR SEVERE WEATHER APPEARS QUITE LOW. EXPECT HIGHS EACH DAY IN THE LOWER TO MID 90S INLAND/MID 80S ON THE BEACHES AND LOWS IN THE LOWER TO MID 70S INLAND/MID TO UPPER 70S AT THE COAST THROUGH THE PERIOD. TUESDAY...27/00Z GUIDANCE DEPICTS AN ILL-DEFINED SHORTWAVE AND ASSOCIATED DEEPER MOISTURE BEGINNING TO SPILL INTO THE REGION FROM THE NORTH AND INTERACTING WITH THE SEA BREEZE DURING THE AFTERNOON. WHILE GUIDANCE HAS OFFERED VERSIONS OF THIS SCENARIO FOR THE PAST FEW DAYS...RUN TO RUN CONSISTENCY HAD REMAINED RATHER POOR ESPECIALLY REGARDING QPF. THE 27/00Z RUNS OF THE NAM AND EUROPEAN DEPICT A FAIR AMOUNT OF CONVECTION COVERAGE TUESDAY AFTERNOON/EVENING...WHILE THE GFS PRODUCES VIRTUALLY NO CONVECTIVE QPF DURING THIS PERIOD. SLIGHT CHANCE/CHANCE POPS ARE JUSTIFIED ESPECIALLY INLAND TUESDAY AFTERNOON/EVENING...BUT FORECAST CONFIDENCE IS NOT HIGH DUE TO MODEL DIFFERENCES AND DUE TO THE POTENTIAL FOR A POCKET OF RELATIVELY DRY 805-500 MB AIR AND AN ASSOCIATED CAP TO REMAIN OVER THE REGION. WEDNESDAY...MAINTAINED SLIGHT CHANCE TO CHANCE POPS...HIGHEST WEST OF I-95...AS A WEAK SHORTWAVE PUSHES THROUGH THEN SOUTH OF THE REGION AND INTERACTS WITH THE SEA BREEZE. PER PROGS OF 850-500 MB RH AND OF K/SHOWALTER INDICES...DRY AIR ALOFT IS PROGGED TO SURGE SOUTH/SOUTHWEST INTO THE REGION LATE WEDNESDAY THROUGH THURSDAY...SEPARATING POOLS OF DEEPER MOISTURE/ ENHANCED PWATS TO THE NORTH/WEST AND SOUTH/SOUTHEAST OF THE REGION. THE GFS HOLDS THIS DRY AIR OFFSHORE...DUE TO LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST...WHILE THE NAM AND EUROPEAN PUSH THIS DRY/CAPPED ENVIRONMENT DIRECTLY OVER THE FORECAST AREA. MAINTAINED SLIGHT CHANCE/LOW CHANCE POPS THURSDAY AFTERNOON...BUT THESE POPS COULD PROVE TO BEE TOO HIGH THURSDAY. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... A POCKET OF RELATIVELY DRY/CAPPED AIR COULD LINGER OVER THE REGION FRIDAY...PERHAPS LIMITING CONVECTION COVERAGE SOMEWHAT EVEN AS A TROUGH OF LOW PRESSURE SETTLES INTO THE SOUTHEAST AT THE SURFACE AND ALOFT. THEN...A TRANSITION TO A WETTER REGIME WITH SLIGHTLY BELOW NORMAL HIGH TEMPERATURES IS EXPECTED THIS WEEKEND...AND THIS UNSETTLED PATTERN COULD PERSIST INTO EARLY NEXT WEEK. THE LATEST FORECAST DEPICTS ABOVE-NORMAL POPS THIS WEEKEND AND INTO EARLY NEXT WEEK. BECAUSE OF THE UNCERTAINTY COMMON TO MEDIUM RANGE FORECASTS OF CONVECTION...CAPPED MAXIMUM POPS AT AROUND 50 PERCENT SATURDAY THROUGH MONDAY. EVENTUALLY...PERIODS OF HIGHER POPS WILL LIKELY BE REQUIRED FOR SOME OR ALL OF THE FORECAST AREA. && .AVIATION /11Z MONDAY THROUGH FRIDAY/... KCHS...DENSE FOG WILL LINGER AT THE TERMINAL THROUGH ABOUT 13Z WITH CONDITIONS RAPIDLY IMPROVING THEREAFTER AS MIXING HEIGHTS INCREASE. EXPECT VFR TO PREVAIL FOR THE REMAINDER OF THE TAF PERIOD. KSAV...SO FAR FOG HAS BEEN REMAIN JUST TO THE NORTH OF THE TERMINAL...ALTHOUGH IFR CIGS HAVE DEVELOPED. LATEST RAP SOUNDINGS SUGGEST IFR CIGS WILL LINGER THROUGH ABOUT 14Z WITH A RAPID IMPROVEMENT TO VFR EXPECTED THEREAFTER. VFR WILL PREVAIL FOR THE REMAINDER OF THE TAF PERIOD. ISOLATED SHOWERS/TSTMS WILL BE AROUND THE TERMINAL THIS AFTERNOON AS THE SEA BREEZE MOVES INLAND. DIRECT IMPACTS ARE UNLIKELY GIVEN THE ISOLATED NATURE OF THE CONVECTION. WILL NOT INTRODUCE A MENTION OF SHRA OR TSRA WITH THIS TAF CYCLE. EXTENDED AVIATION OUTLOOK...LOW PROBABILITY FOR FLIGHT RESTRICTIONS IN EARLY MORNING STRATUS/FOG AND WITHIN AFTERNOON THUNDERSTORMS TUESDAY THROUGH FRIDAY. && .MARINE... A MARINE DENSE FOG ADVISORY HAS BEEN ISSUED FOR CHARLESTON HARBOR UNTIL 9 AM. EXPECT AREAS OF DENSE FOG WITH VSBYS LESS THAN 1 NM TO PREVAIL DURING THIS TIME. THE LOWEST VSBYS WILL OCCUR IN THE UPPER HARBOR...MAINLY NORTH OF THE RAVENEL BRIDGE. TODAY...EAST/NORTHEAST WIND REGIME WILL HOLD IN PLACE TODAY AS THE AREA REMAINS WEDGED IN BY HIGH PRESSURE ALONG THE COAST AND A SURFACE TROUGH OFFSHORE. SPEEDS WILL BE MODEST FOR LATE JULY...10-15 KT WITH LOCALLY HIGHER SPEEDS IN THE HARBOR AND ALONG THE LAND/SEA INTERFACE AS THE SEA BREEZE MOVES INLAND. SEAS WILL AVERAGE 2-3 FT. TONIGHT...WIND DIRECTIONS WILL BE TRICKY TO PIN DOWN AS AN AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ALONG THE OFFSHORE TROUGH. EXPECT NORTHEAST WINDS TO LINGER OFF THE CHARLESTON COUNTY COAST FOR MUCH OF THE NIGHT WITH DIRECTIONS BACKING NORTH OR EVEN NORTHWEST FOR THE REMAINING PARTS OF THE MARINE AREA AS THE LOW PASSES OFF THE GEORGIA COAST. SPEEDS LOOK TO BE AROUND 10 KT WITH SEAS 2-3 FT. TUESDAY THROUGH SATURDAY...PERSISTENT ONSHORE WINDS...ENHANCED BY THE DAILY SEA BREEZE CIRCULATION BUT CAPPED AT AROUND 15 KT...WILL PERSIST THROUGH TUESDAY THROUGH THURSDAY. THEN...WINDS SHOULD TURN TOWARD THE S/SW FRIDAY-SATURDAY...PERHAPS INCREASING TO 15-20 KT IN SOME AREAS WITH THE AFTERNOON SEA BREEZE AND WITH NOCTURNAL SURGES. SEAS SHOULD REMAIN 2-4 FT THROUGH THE PERIOD...HIGHEST AT 20 NM AND BEYOND. && .TIDES/COASTAL FLOODING... TIDAL DEPARTURES WILL CONTINUE TO SLOWLY RISE TODAY AS WATER LOADS INTO THE MARSHES AND WATERWAYS DUE TO THE INFLUENCES OF THE ONGOING EAST/NORTHEAST WIND SURGE AND THE APPROACHING FULL MOON AND PERIGEE. TIDE LEVELS COULD GET VERY CLOSE TO COASTAL FLOOD ADVISORY CRITERIA ALONG THE LOWER SOUTH CAROLINA WITH THE LATE AFTERNOON/EARLY EVENING HIGH TIDE CYCLE...BUT THE LATEST SET OF SURGE MODELS KEEP LEVELS JUST SHY OF THE ADVISORY BENCHMARK OF 7.0 FT MLLW IN THE CHARLESTON HARBOR. TIDES LOOK TO REMAIN ABOUT 0.50-0.75 FT BELOW ADVISORY CRITERIA AT FORT PULASKI ALONG THE NORTH GEORGIA COAST. THE UPCOMING FULL MOON...PERIGEE AND PERSISTENT ONSHORE WINDS COULD CONTRIBUTE TO SHALLOW SALT WATER FLOODING AROUND THE TIMES OF EVENING HIGH TIDES TUESDAY THROUGH NEXT WEEKEND AND LIKELY INTO EARLY NEXT WEEK AS WELL. WHILE THE PROBABILITY FOR A SERIES OF COASTAL FLOOD ADVISORY EVENTS SHOULD INCREASE AS WE DRAW CLOSER TO THE JULY 31 FULL MOON/AUG 2 PERIGEE...DUE TO PERSISTENT EAST/NORTHEAST WINDS FORECAST BY THE GFS THE EXTRATROPICAL SURGE MODEL CONTINUES TO DEPICT THE EVENING HIGH TIDE EXCEEDING SHALLOW COASTAL FLOODING LEVELS ALONG THE SC COAST AS EARLY AS TUESDAY- WEDNESDAY. WILL CONTINUE TO HIGHLIGHT THE POTENTIAL FOR SHALLOW SALT WATER FLOODING WITHIN THE HAZARDOUS WEATHER OUTLOOK. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ088-101. SC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ040- 042>045-047>052. MARINE...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR AMZ330. && $$ ST/SPR
AREA FORECAST DISCUSSION
NWS LINCOLN IL
250 AM CDT MON JUL 27 2015 .SHORT TERM...(TODAY) ISSUED AT 247 AM CDT MON JUL 27 2015 MAIN FORECAST CONCERNS TODAY, MUCH LIKE THE PAST TWO DAYS, REVOLVE AROUND THUNDERSTORM CHANCES AND HOW HIGH PEAK AFTERNOON HEAT INDEX VALUES WILL CLIMB. THUNDERSTORM COVERAGE THE PAST TWO DAYS HAS NOT BEEN BEEN VERY HIGH DESPITE DECENT INSTABILITY AND LITTLE/NO CAPPING. FORECAST INSTABILITY TODAY IS EXPECTED TO BE SIMILAR TO THE PAST COUPLE OF DAYS, WITH PEAK VALUES IN THE 2500-3500 J/KB RANGE (HIGHEST IN THE SOUTHERN HALF OF THE FORECAST AREA). SHEAR PROFILES OVER THE WEEKEND WERE ALSO MODEST, AND SHOULD BE EVEN WEAKER TODAY WITH BULK SHEAR VALUES ONLY FORECAST TO BE AROUND 20 KTS. THE MAIN FOCUS FOR STORMS TODAY WILL BE THE WEAK STATIONARY FRONT THAT LIES ROUGHLY WEST-EAST ACROSS CENTRAL ILLINOIS, AND POSSIBLY OUTFLOW BOUNDARIES FROM CONVECTION THAT IS CURRENTLY OCCURRING JUST TO OUR SOUTH. BOTTOM LINE, PLAN TO CARRY ONLY SLIGHT CHANCE/ISOLATED POPS TODAY, LIMITING THEM MAINLY TO THE SOUTHERN HALF OF THE FORECAST AREA WHERE INSTABILITY AND THE THREAT OF A FOCUSING BOUNDARY SHOULD BE HIGHEST. TEMPERATURES TODAY SHOULD BE A LITTLE WARMER THAN YESTERDAY, MOSTLY DUE TO LESS PRECIPITATION COVERAGE AND AN ASSOCIATED REDUCTION IN CLOUD COVER. HOWEVER, WITH THE LINGERING STATIONARY BOUNDARY IN PLACE, AND LIGHT LOW LEVEL WINDS IN ITS VICINITY, NO SIGNIFICANT AIRMASS CHANGE IS ANTICIPATED. THIS SCENARIO RESULTS IN PEAK AFTERNOON HEAT INDEX VALUES AROUND 100 OVER THE SOUTHERN PORTION OF THE FORECAST AREA. SO, WHILE IT WILL BE QUITE WARM/HUMID ONCE AGAIN TODAY, EXPECTED VALUES REMAIN BELOW ADVISORY CRITERIA. && .LONG TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 247 AM CDT MON JUL 27 2015 DEEP UPPER TROUGH ALONG THE WEST COAST HELPING TO PUSH THE UPPER RIDGE EASTWARD THE NEXT COUPLE DAYS...AS A STRONG LOW DEVELOPS WITHIN THE TROUGH AND LIFTS NORTHEAST INTO WESTERN ONTARIO BY WEDNESDAY MORNING. TUESDAY STILL LOOKING TO BE THE HOTTEST DAY OF THE PERIOD WITH 925 MB TEMPERATURES REACHING 27-28C BY AFTERNOON. MOST OF THE CWA SHOULD SEE TRIPLE DIGIT HEAT INDICES BY TUESDAY AND BE NEAR 110 FROM ABOUT SPRINGFIELD-HAVANA WESTWARD. WE`RE STARTING TO GET CLOSE TO THE TIME WE`LL NEED TO ISSUE A HEAT ADVISORY...BUT WITH ADVISORY CONDITIONS STILL OVER 30 HOURS AWAY...WILL LIKELY WAIT FOR THE AFTERNOON FORECAST PACKAGE BEFORE ISSUING IT. COLD FRONT ASSOCIATED WITH THE LOW STILL EXPECTED TO CROSS THE FORECAST AREA ON WEDNESDAY...WITH SOME 100-105 HEAT INDICES EAST OF I-57 BEFORE THE FRONT BRINGS LOWER DEW POINTS BY MID AFTERNOON. MORE COMFORTABLE CONDITIONS EXPECTED THE REMAINDER OF THE WEEK WITH A GENERAL NORTHWEST FLOW...ALTHOUGH DEW POINTS ARE EXPECTED TO START CREEPING UP AGAIN NEXT WEEKEND. PRECIPITATION-WISE...ANY ISOLATED STORMS SHOULD FADE OFF EARLY THIS EVENING. HAVE LARGELY REMOVED POP`S FOR TUESDAY AS THERE NOT BE MUCH OF A FORCING MECHANISM IN MOST AREAS...ALTHOUGH THE NMM MODEL HINTS AT SOME ISOLATED CONVECTION ACROSS WESTERN ILLINOIS DURING THE AFTERNOON AS THE SOUTHERLY FLOW STARTS TO KICK IN. MAIN FOCUS FOR RAIN WILL BE WITH THE PASSAGE OF THE FRONT...PRIMARILY LATE TUESDAY NIGHT AND WEDNESDAY MORNING. DRY CONDITIONS EXPECTED THE REMAINDER OF THE WEEK...WITH THE NEXT CHANCES ON SUNDAY WITH THE ARRIVAL OF A COLD FRONT BY AFTERNOON AS ADVERTISED BY THE GFS AND ECMWF MODELS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1154 PM CDT SUN JUL 26 2015 FOG FORMATION IS THE MAIN CONCERN FOR THE REST OF THE NIGHT. BMI DROPPED TO 1/4SM FG FOR A WHILE ALREADY THIS EVENING, ALTHOUGH WEB CAMS FROM AROUND BLOOMINGTON/NORMAL DO NOT SHOW MUCH IN THE WAY OF FOG AWAY FROM THE AIRPORT. HAVE INCLUDED A TEMPO FOR VLIFR FOG AT BMI LATER TONIGHT. THE NAM AND HRRR ARE SHOWING AREAS OF DENSE FOG ACROSS CENTRAL IL. WILL INCLUDE 1/2SM FG IN A TEMPO FOR DEC AND CMI, WITH TEMPOS FOR 3/4SM AND 1SM FOR PIA AND SPI RESPECTIVELY. THE CIRRUS OVERCAST FROM CONVECTION IN THE PLAINS MAY REACH PIA AND SPI LATER TONIGHT, HELPING TO KEEP DENSE FOG FROM FORMING. EASTERN AREAS MAY SEE ENOUGH CLEAR SKIES FOR A HIGHER POTENTIAL OF LOCALLY DENSE FOG. ONCE THE FOG CLEARS AFTER SUNRISE, VFR CONDITIONS SHOULD PREVAIL THE REMAINDER OF THE TAF PERIOD. EASTERLY WINDS SHOULD PREVAIL ACROSS THE AREA AS WE REMAIN BETWEEN A TROUGH ACROSS SOUTHERN ILLINOIS AND A STATIONARY FRONT ACROSS NORTHERN IL. WIND SPEEDS SHOULD PREVAIL AT LESS THAN 10KT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BAK LONG TERM...GEELHART AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1154 PM CDT SUN JUL 26 2015 .UPDATE... ISSUED AT 900 PM CDT SUN JUL 26 2015 ANY LINGERING SCATTERED SHOWERS WILL PRIMARILY DISSIPATE OR MOVE EAST OF OUR COUNTIES IN THE NEXT HOUR OR SO. THE PROBABILITY OF ADDITIONAL SHOWER OR STORM DEVELOPMENT LATER TONIGHT APPEARS LOW, BUT ANY DEVELOP THEY WILL MAINLY BE FOCUSED ALONG AND SOUTH OF I-72, WHERE A SURFACE TROUGH AXIS HAS STALLED OUT. WE KEPT ONLY SLIGHT CHANCE POPS IN THE SOUTHERN COUNTIES OVERNIGHT, BUT MOST AREAS WILL REMAIN DRY. DEWPOINTS WILL REMAIN IN THE UPPER 60S TO AROUND 70 OVERNIGHT, WHICH WILL CREATE FAVORABLE CONDITIONS FOR FOG FORMATION. MOST AREAS SHOULD ONLY SEE 3-4 MILE VISIBILITY, BUT LOCALIZED AREAS COULD DROP LESS THAN A MILE, PER HRRR OUTPUT. HAVE ADDED FOG TO THE FORECAST FOR LATER TONIGHT, MAINLY NORTH OF I-70 FOR NOW. WILL MONITOR FOR POSSIBLE NEED TO EXPAND FOG COVERAGE. UPDATES THIS EVENING WERE MAINLY TO POP AND WEATHER, WITH MINOR ADJUSTMENTS TO HOURLY TEMP, DEWPOINTS, AND SKY. && .SHORT TERM...(TONIGHT) ISSUED AT 251 PM CDT SUN JUL 26 2015 MORNING MCS HAS COMPLETELY DISSIPATED ACROSS CENTRAL ILLINOIS EARLY THIS AFTERNOON...WITH 19Z/2PM RADAR IMAGERY SHOWING NO LINGERING PRECIP. THE FOCUS FOR ADDITIONAL CONVECTION THIS AFTERNOON AND EVENING WILL SHIFT FURTHER NORTH AND EAST ALONG A NEARLY STATIONARY FRONTAL BOUNDARY EXTENDING FROM NORTH-CENTRAL INDIANA INTO EASTERN IOWA. SCATTERED THUNDERSTORMS ARE ALREADY DEVELOPING ALONG THE BOUNDARY WITHIN A NARROW INSTABILITY AXIS CHARACTERIZED BY SBCAPES OF 1500 TO 2500J/KG. HRRR HAS BEEN CONSISTENTLY SHOWING STORMS FIRING ALONG THE FRONT THIS AFTERNOON, AS WELL AS ALONG AN OUTFLOW BOUNDARY/DIFFERENTIAL HEATING BOUNDARY CREATED BY THE MORNING MCS. GIVEN CURRENT SATELLITE/RADAR TRENDS...SEE NO REASON TO STRAY FROM THIS SOLUTION. AS A RESULT...HAVE FOCUSED HIGHEST POPS ALONG/NORTH OF I-74 AND EAST OF I-55 THIS AFTERNOON INTO THE EVENING. ANY STORMS THAT DEVELOP WILL BE DIURNALLY DRIVEN AND WILL LIKELY DISSIPATE AFTER SUNSET. AFTER THAT...THE QUESTION BECOMES WHETHER ANY NOCTURNAL CONVECTION CAN DEVELOP OVERNIGHT. THE HRRR AND RAPID REFRESH MODELS SAY NO...HOWEVER THE NAM KEEPS AT LEAST SCATTERED PRECIP GOING. THE MAIN 850MB JET WILL BE ORIENTED FROM THE SOUTHERN PLAINS INTO THE DAKOTAS TONIGHT...SO THERE WILL NOT BE MUCH SUPPORT FOR OVERNIGHT STORMS IN ILLINOIS. WITH THAT BEING SAID...NAM DOES SHOW A WEAK 20-25KT BRANCH OF THE LLJ NOSING INTO THE AREA. WITH THIS WEAK INFLOW COMBINED WITH THE PRESENCE OF THE STATIONARY FRONTAL BOUNDARY IN THE VICINITY...HAVE OPTED TO MAINTAIN JUST SLIGHT CHANCE POPS AFTER MIDNIGHT. LOW TEMPERATURES WILL ONCE AGAIN BE IN THE LOWER 70S. .LONG TERM...(MONDAY THROUGH SUNDAY) ISSUED AT 251 PM CDT SUN JUL 26 2015 WITH HIGH PRESSURE TO THE NORTHEAST AND A WEAK RESIDUAL BOUNDARY IN OR CLOSE TO THE CWA...BELIEVE A SMALL CHANCE/SLIGHT CHANCE OF PCPN WILL REMAIN POSSIBLE TOMORROW THROUGH TUE. THIS WILL ONLY BE SEEN THROUGH MONDAY NIGHT IN THE WORDING...BUT WILL BE SEEN THROUGH TUE. ONCE THIS WEAK BOUNDARY BREAKS DOWN ENOUGH TUE NIGHT SHOULD BE MOSTLY DRY EXCEPT IN THE NORTHWEST OF THE IL RIVER WITH APPROACH OF THE NEXT WEATHER SYSTEM. MODELS HAVE GOTTEN LITTLE FASTER WITH THIS FRONT AND IT NOW ARRIVES EARLY ON WED IN THE AREA. CONVECTION WILL BE POSSIBLE ALONG THIS FRONT WED AND THEN QUICKLY EXIT THE AREA LATE WED AFTERNOON...SO WED NIGHT SHOULD BE DRY THROUGHOUT THE CWA. TEMPS WILL BE QUITE WARM THROUGH WED WITH UPPER 80S TO LOWER 90S POSSIBLE MON AND WED...AND LOWER TO MIDDLE 90S LIKELY FOR TUESDAY. THIS HEAT WILL COMBINE WITH DWPTS IN THE 70S...UPPER 70S ON TUESDAY...TO CREATE HEAT INDEX VALUES OF 90S TO 105 FOR MON AND WED...AND 105-110 FOR TUESDAY. HEAT ADVISORY CRITERIA...105...WILL BE CLOSE TOMORROW BUT ONLY IN EXTREME WESTERN COUNTIES. SO LEANING AWAY FROM ADVISORY AT THIS TIME. CRITERIA IS MET ON TUE AND THEN MAYBE IN THE SOUTHEAST PARTS OF THE CWA FOR WED. OVERNIGHT SHIFT CAN GET ANOTHER LOOK FOR TOMORROW BECAUSE CLOUDS AND POSSIBLE PCPN COULD BE A LIMITING FACTOR. ONCE THE MID WEEK FRONT MOVES THROUGH DRY WEATHER IS EXPECTED THE REST OF THE WEEK AND INTO THE WEEKEND. COOL CANADIAN HIGH PRESSURE IS EXPECTED OVER THE AREA...WHICH WILL ALSO BRING IN DRIER DWPTS TO THE AREA. THIS RIDGE DOES BEGIN TO BREAK DOWN OVER THE WEEKEND AND WILL ALLOW A FRONT TO DROP INTO THE AREA FOR THE LAST PART OF THE WEEKEND. FOR NOW WILL JUST HAVE A SLIGHT CHANCE OF PCPN FOR SAT NIGHT AND SUNDAY. TEMPS WILL ALSO BE COOLER WITH AFTERNOON HIGHS REMAINING IN THE 80S THROUGH THE PERIOD AND OVERNIGHT LOWS IN THE 60S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1154 PM CDT SUN JUL 26 2015 FOG FORMATION IS THE MAIN CONCERN FOR THE REST OF THE NIGHT. BMI DROPPED TO 1/4SM FG FOR A WHILE ALREADY THIS EVENING, ALTHOUGH WEB CAMS FROM AROUND BLOOMINGTON/NORMAL DO NOT SHOW MUCH IN THE WAY OF FOG AWAY FROM THE AIRPORT. HAVE INCLUDED A TEMPO FOR VLIFR FOG AT BMI LATER TONIGHT. THE NAM AND HRRR ARE SHOWING AREAS OF DENSE FOG ACROSS CENTRAL IL. WILL INCLUDE 1/2SM FG IN A TEMPO FOR DEC AND CMI, WITH TEMPOS FOR 3/4SM AND 1SM FOR PIA AND SPI RESPECTIVELY. THE CIRRUS OVERCAST FROM CONVECTION IN THE PLAINS MAY REACH PIA AND SPI LATER TONIGHT, HELPING TO KEEP DENSE FOG FROM FORMING. EASTERN AREAS MAY SEE ENOUGH CLEAR SKIES FOR A HIGHER POTENTIAL OF LOCALLY DENSE FOG. ONCE THE FOG CLEARS AFTER SUNRISE, VFR CONDITIONS SHOULD PREVAIL THE REMAINDER OF THE TAF PERIOD. EASTERLY WINDS SHOULD PREVAIL ACROSS THE AREA AS WE REMAIN BETWEEN A TROUGH ACROSS SOUTHERN ILLINOIS AND A STATIONARY FRONT ACROSS NORTHERN IL. WIND SPEEDS SHOULD PREVAIL AT LESS THAN 10KT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SHIMON SHORT TERM...BARNES LONG TERM...AUTEN AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1022 PM EDT TUE JUL 28 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 306 PM EDT TUE JUL 28 2015 HOT AND HUMID CONDITIONS WILL PERSIST INTO WEDNESDAY. A COLD FRONT WILL THEN MOVE INTO CENTRAL INDIANA BRINGING SCATTERED SHOWERS AND THUNDERSTORMS. DRIER AIR WILL THEN MOVE IN TO END THE WORK WEEK. ANOTHER FRONT COULD BRING CHANCES FOR RAIN EARLY NEXT WEEK. && .NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/ ISSUED AT 935 PM EDT TUE JUL 28 2015 EARLIER THIS EVENING REMOVED PRECIP CHANCES FROM THE FORECAST AREA UNTIL LATE DURING THE OVERNIGHT PERIOD AS POP UP SHOWERS AND STORMS HAVE DISSIPATED ACROSS THE AREA. HRRR AND NAM STILL SHOW SOME STORMS CURRENTLY OVER IOWA MOVING INTO THE AREA LATE DURING THE OVERNIGHT. THUS MADE NO CHANGES TO POPS AFTER 6Z AND KEPT BRINGING THEM INTO THE NORTHWEST AFTER 8Z. OVERNIGHT LOWS IN THE 70S LOOK GOOD BASED ON DEWPOINTS RIGHT NOW IN THE LOW TO MIDDLE 70S AND NO REAL ADVECTION GOING ON. TIME HEIGHTS AND CROSSOVER TEMPERATURES ALONG WITH SREF PROBABILITIES ARE NOT SHOWING MUCH FOR FOG DEVELOPMENT SO WILL CONTINUE TO LEAVE THAT OUT OF THE FORECAST DESPITE THE AMPLE LOW LEVEL MOISTURE. PREVIOUS DISCUSSION FOLLOWS... FOCUS TURNS TO OTHER STORMS MOVING IN LATE. SOME MODELS SHOW STORMS SURVIVING AND MOVING IN LATE TONIGHT ALONG A PREFRONTAL FEATURE. WITH SOME WEAK LIFT AROUND...FEEL THAT THIS THREAT LOOKS GOOD ENOUGH TO GO SLIGHT CHANCE TO LOW END CHANCE POPS 08-12Z. WITH A HUMID AIRMASS IN PLACE A MODEL BLEND OF TEMPERATURES IN THE LOW TO MID 70S LOOKS GOOD FOR LOWS. && .SHORT TERM.../WEDNESDAY THROUGH FRIDAY/ ISSUED AT 306 PM EDT TUE JUL 28 2015 FOCUS IS ON CHANCES FOR RAIN WEDNESDAY. MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED. SOME UNCERTAINTY ON HOW CONVECTION WILL DEVELOP AHEAD OF THE A COLD FRONT ON WEDNESDAY. LINGERING MORNING CONVECTION OR ITS REMNANTS MAY HELP INHIBIT AFTERNOON CONVECTION. HOWEVER IF IT DIES QUICKLY OR DOES NOT MAKE IT INTO THE AREA...ATMOSPHERE WILL BE IN GOOD SHAPE FOR DEVELOPMENT OF AFTERNOON STORMS. GIVEN THE UNCERTAINTY DECIDED TO KEEP POPS BELOW LIKELY CATEGORY. TRIED TO TIME HOURLY POPS SO THAT BEST CHANCE OCCURS LATE MORNING/EARLY AFTERNOON NORTHWEST TO MID AFTERNOON SOUTHEAST WITH THE TIMING OF THE FRONT. STUCK WITH MODEL BLEND FOR HIGH TEMPERATURES WEDNESDAY...BUT THESE TOO MAY DEPEND ON HOW MORNING CONVECTION PLAYS OUT. APPARENT TEMPERATURES WILL BE NEAR HEAT ADVISORY CRITERIA SOUTHWEST...BUT THEE CONDITIONS LOOK TO BE RELATIVELY BRIEF. THIS PLUS THE UNCERTAINTY IN THE RAIN/CLOUD COVER LEADS TO NOT ISSUE A HEAT ADVISORY. KEPT SOME LOW END EVENING POPS WEDNESDAY AS THE FRONT MOVES THROUGH. AFTERWARD...HIGH PRESSURE WILL BUILD IN AND BRING DRY CONDITIONS INTO FRIDAY. GENERALLY STUCK WITH A MODEL BLEND FOR TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... ISSUED AT 231 PM EDT TUE JUL 28 2015 THE FORECAST FOR THIS WEEKEND IS LOOKING COMPLETELY DRY AS A LARGE AREA OF HIGH PRESSURE REMAINS IN CONTROL OVER THE REGION. ENSEMBLES SHOWING A WEAK COLD FRONT NOT MOVING ACROSS OUR REGION UNTIL EARLY MONDAY...WITH A SECONDARY AND EVEN WEAKER FRONT FOLLOWING ON TUESDAY. INCLUDED SOME LOW CHANCES FOR SHOWERS AND STORMS DURING EARLY NEXT WORK WEEK...WITH SLIGHTLY HIGHER POPS ACROSS THE NORTH...CLOSER TO THESE FEATURES. GENERALLY WENT WITH SUPERBLEND INITIALIZATION AS THIS GUIDANCE APPEARS TO BE IN LINE WITH THE CURRENT FORECAST. && .AVIATION /DISCUSSION FOR THE 290300Z IND TAF UPDATE/... ISSUED AT 1022 PM EDT TUE JUL 28 2015 NO SIGNIFICANT CHANGES TO THE TAF. PREVIOUS DISCUSSION FOLLOWS... ISSUED AT 725 PM EDT TUE JUL 28 2015 A WEAK FRONTAL BOUNDARY DRAPED ACROSS CENTRAL INDIANA FROM KLAF SOUTHEASTWARD OVER KIND ALONG WITH SEVERAL OUTFLOW BOUNDARIES WILL KEEP WIND DIRECTIONS VARIABLE TO START THE PERIOD. THE WINDS WILL SETTLE INTO A STEADY SOUTHWESTERLY FLOW BY 08Z...WITH SPEEDS UNDER 10 KTS EXCEPT IN OR NEAR THUNDERSTORMS. VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE PERIOD. A COLD FRONT WILL APPROACH CENTRAL INDIANA FROM THE WEST EARLY WEDNESDAY...BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS. PRECIP WILL MOVE OUT OF KLAF AND KHUF BY 22Z...AND KIND AND KBMG NEAR 00Z. TEMPORARY MVFR CONDITIONS ARE POSSIBLE IN THUNDERSTORMS. CROSSOVER TEMPERATURES SUGGEST THAT THERE IS A SLIGHT CHANCE FOR FOG TO DEVELOP IN KHUF BETWEEN 10Z AND 12Z. SREF MODEL PROBABILITIES OF MVFR VISIBILIES OR WORSE ARE LOW ENOUGH TO KEEP MENTION OUT OF THE TAFS AT THIS TIME. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...50/CP SHORT TERM...50 LONG TERM....SMF AVIATION...MMB/MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
935 PM EDT TUE JUL 28 2015 .UPDATE... THE NEAR TERM SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 306 PM EDT TUE JUL 28 2015 HOT AND HUMID CONDITIONS WILL PERSIST INTO WEDNESDAY. A COLD FRONT WILL THEN MOVE INTO CENTRAL INDIANA BRINGING SCATTERED SHOWERS AND THUNDERSTORMS. DRIER AIR WILL THEN MOVE IN TO END THE WORK WEEK. ANOTHER FRONT COULD BRING CHANCES FOR RAIN EARLY NEXT WEEK. && .NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/ ISSUED AT 935 PM EDT TUE JUL 28 2015 EARLIER THIS EVENING REMOVED PRECIP CHANCES FROM THE FORECAST AREA UNTIL LATE DURING THE OVERNIGHT PERIOD AS POP UP SHOWERS AND STORMS HAVE DISSIPATED ACROSS THE AREA. HRRR AND NAM STILL SHOW SOME STORMS CURRENTLY OVER IOWA MOVING INTO THE AREA LATE DURING THE OVERNIGHT. THUS MADE NO CHANGES TO POPS AFTER 6Z AND KEPT BRINGING THEM INTO THE NORTHWEST AFTER 8Z. OVERNIGHT LOWS IN THE 70S LOOK GOOD BASED ON DEWPOINTS RIGHT NOW IN THE LOW TO MIDDLE 70S AND NO REAL ADVECTION GOING ON. TIME HEIGHTS AND CROSSOVER TEMPERATURES ALONG WITH SREF PROBABILITIES ARE NOT SHOWING MUCH FOR FOG DEVELOPMENT SO WILL CONTINUE TO LEAVE THAT OUT OF THE FORECAST DESPITE THE AMPLE LOW LEVEL MOISTURE. PREVIOUS DISCUSSION FOLLOWS... FOCUS TURNS TO OTHER STORMS MOVING IN LATE. SOME MODELS SHOW STORMS SURVIVING AND MOVING IN LATE TONIGHT ALONG A PREFRONTAL FEATURE. WITH SOME WEAK LIFT AROUND...FEEL THAT THIS THREAT LOOKS GOOD ENOUGH TO GO SLIGHT CHANCE TO LOW END CHANCE POPS 08-12Z. WITH A HUMID AIRMASS IN PLACE A MODEL BLEND OF TEMPERATURES IN THE LOW TO MID 70S LOOKS GOOD FOR LOWS. && .SHORT TERM.../WEDNESDAY THROUGH FRIDAY/ ISSUED AT 306 PM EDT TUE JUL 28 2015 FOCUS IS ON CHANCES FOR RAIN WEDNESDAY. MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED. SOME UNCERTAINTY ON HOW CONVECTION WILL DEVELOP AHEAD OF THE A COLD FRONT ON WEDNESDAY. LINGERING MORNING CONVECTION OR ITS REMNANTS MAY HELP INHIBIT AFTERNOON CONVECTION. HOWEVER IF IT DIES QUICKLY OR DOES NOT MAKE IT INTO THE AREA...ATMOSPHERE WILL BE IN GOOD SHAPE FOR DEVELOPMENT OF AFTERNOON STORMS. GIVEN THE UNCERTAINTY DECIDED TO KEEP POPS BELOW LIKELY CATEGORY. TRIED TO TIME HOURLY POPS SO THAT BEST CHANCE OCCURS LATE MORNING/EARLY AFTERNOON NORTHWEST TO MID AFTERNOON SOUTHEAST WITH THE TIMING OF THE FRONT. STUCK WITH MODEL BLEND FOR HIGH TEMPERATURES WEDNESDAY...BUT THESE TOO MAY DEPEND ON HOW MORNING CONVECTION PLAYS OUT. APPARENT TEMPERATURES WILL BE NEAR HEAT ADVISORY CRITERIA SOUTHWEST...BUT THEE CONDITIONS LOOK TO BE RELATIVELY BRIEF. THIS PLUS THE UNCERTAINTY IN THE RAIN/CLOUD COVER LEADS TO NOT ISSUE A HEAT ADVISORY. KEPT SOME LOW END EVENING POPS WEDNESDAY AS THE FRONT MOVES THROUGH. AFTERWARD...HIGH PRESSURE WILL BUILD IN AND BRING DRY CONDITIONS INTO FRIDAY. GENERALLY STUCK WITH A MODEL BLEND FOR TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... ISSUED AT 231 PM EDT TUE JUL 28 2015 THE FORECAST FOR THIS WEEKEND IS LOOKING COMPLETELY DRY AS A LARGE AREA OF HIGH PRESSURE REMAINS IN CONTROL OVER THE REGION. ENSEMBLES SHOWING A WEAK COLD FRONT NOT MOVING ACROSS OUR REGION UNTIL EARLY MONDAY...WITH A SECONDARY AND EVEN WEAKER FRONT FOLLOWING ON TUESDAY. INCLUDED SOME LOW CHANCES FOR SHOWERS AND STORMS DURING EARLY NEXT WORK WEEK...WITH SLIGHTLY HIGHER POPS ACROSS THE NORTH...CLOSER TO THESE FEATURES. GENERALLY WENT WITH SUPERBLEND INITIALIZATION AS THIS GUIDANCE APPEARS TO BE IN LINE WITH THE CURRENT FORECAST. && .AVIATION /DISCUSSION FOR THE 290000Z TAF ISSUANCE/... ISSUED AT 725 PM EDT TUE JUL 28 2015 A WEAK FRONTAL BOUNDARY DRAPED ACROSS CENTRAL INDIANA FROM KLAF SOUTHEASTWARD OVER KIND ALONG WITH SEVERAL OUTFLOW BOUNDARIES WILL KEEP WIND DIRECTIONS VARIABLE TO START THE PERIOD. THE WINDS WILL SETTLE INTO A STEADY SOUTHWESTERLY FLOW BY 08Z...WITH SPEEDS UNDER 10 KTS EXCEPT IN OR NEAR THUNDERSTORMS. VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE PERIOD. A COLD FRONT WILL APPROACH CENTRAL INDIANA FROM THE WEST EARLY WEDNESDAY...BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS. PRECIP WILL MOVE OUT OF KLAF AND KHUF BY 22Z...AND KIND AND KBMG NEAR 00Z. TEMPORARY MVFR CONDITIONS ARE POSSIBLE IN THUNDERSTORMS. CROSSOVER TEMPERATURES SUGGEST THAT THERE IS A SLIGHT CHANCE FOR FOG TO DEVELOP IN KHUF BETWEEN 10Z AND 12Z. SREF MODEL PROBABILITIES OF MVFR VISIBILIES OR WORSE ARE LOW ENOUGH TO KEEP MENTION OUT OF THE TAFS AT THIS TIME. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...50/CP SHORT TERM...50 LONG TERM....SMF AVIATION...MMB/MK
...UPDATED FOR 27/06Z AVIATION FORECAST DISCUSSION...

.SHORT TERM /TONIGHT/... ISSUED AT 310 PM CDT SUN JUL 26 2015 PRIMARY CONCERNS TONIGHT WILL BE CONVECTION REDEVELOPING AND RADIATION FOG POTENTIAL. IA REMAINS ON SRN EDGE OF MAIN CO/SD/MN/WI WESTERLIES BUT IN THE SUBSIDENCE PORTION OF THE WAVE TRAIN. NOTED DARKENING IN WATER VAPOR WHICH COINCIDES WITH H7/H5 QG IMPLIED DOWNWARD MOTION. THERMODYNAMICALLY...RECENT RAP DOES DEPICT A WEAK H85/H7 WAVE ALONG THE IA/MN BORDER BUT FLOW IS VERY WEAK WITH NEUTRAL ADVECTION...THUS CANNOT SEE WRN DAKOTAS/NE CONVECTION MAINTAINING ITSELF TOO FAR EAST. THERE IS STILL SOME PEAK HEATING POTENTIAL WITH RAP 0-1KM MOISTURE CONVERGENCE SHOWING AN AXIS FROM N CENTRAL INTO S CENTRAL IA...BUT THE LOW LEVEL FLOW IS QUITE WEAK AS WELL. OUTFLOW FROM ERN IA CONVECTION IS APPROACHING IOWA FALLS AND GRINNELL BUT IS REALLY STRUGGLING TO GENERATE ANYTHING AND WITH SURFACE FLOW BEHIND IT NEARLY PARALLEL TO THE BOUNDARY ITS POTENTIAL MAY BE WANING. AIRMASS APPEARS TO BE UNCAPPED AND BOUNDARY IS APPROACHING DEEPER CONVERGENCE AND HIGHER INSTABILITY SO HAVE ADDED TOKEN ISOLATED WORDING INTO THE EARLY EVENING HOURS. HAVE ALSO ADDED PATCHY FOG WORDING AREA WIDE OVERNIGHT. MANY AREAS RECEIVED AT LEAST A HALF INCH OF RAIN OVERNIGHT...AND SOME OVER AN INCH...AND BOUNDARY LAYER HAS REMAINED QUITE MOIST WITH LITTLE MIXING. WINDS STILL NEARLY CALM IN MANY LOCATIONS AND TEMP/DEWPOINT SPREADS ARE LOW FOR 20Z. .LONG TERM /MONDAY THROUGH SUNDAY/... ISSUED AT 310 PM CDT SUN JUL 26 2015 MAIN CONCERN FOR EXTENDED WILL FOCUS ON PRECIPITATION TRENDS AND TEMPERATURES FOR BEGINNING OF PERIOD. LARGE LOW PRESSURE SYSTEM PUSHING EAST ACROSS NORTHWESTERN US WILL PUSH RIDGE...CURRENTLY ACROSS HIGH PLAINS...EAST INTO IOWA THROUGH TUESDAY. AS RIDGE PUSHES EAST TEMPERATURES AND HUMIDITY WILL INCREASE...THOUGH MODELS HAVE BACKED OFF SOMEWHAT ON AMOUNT OF WARM UP...AND HAVE TRENDED TEMPS DOWN SLIGHTLY AS WELL. HOWEVER...HOTTEST DAY WILL COME TUESDAY AHEAD OF BOUNDARY SET TO PUSH SOUTH TUESDAY INTO WEDNESDAY. CURRENT FORECAST WOULD INDICATE NEED FOR HEAT ADVISORY ACROSS MUCH OF SOUTHERN CWA TUESDAY...THOUGH TEMPERATURES TRENDS ARE STILL SOMEWHAT UNCERTAIN...MODELS HAVE BEGUN TO SPEED UP TIMING ON APPROACHING TUESDAY SYSTEM...AND PLACEMENT OF BOUNDARY WILL HAVE LARGE IMPACT ON TEMPERATURES THROUGH THE AFTERNOON. IN ADDITION...PRECIPITATION TRENDS MAY HAVE IMPACT ON AFTERNOON WARMING AS WELL. PRECIPITATION REMAINS CHALLENGING AHEAD OF BOUNDARY. WEAK BAND OF ADVECTION PUSHES ACROSS THE NORTH MONDAY AFTERNOON...AND HAVE INCLUDED MENTION FOR PRECIPITATION ACROSS THE NORTHWEST WITH INSTABILITY SUFFICIENT FOR STORMS TO FORM. BEST CHANCES FOR THUNDERSTORMS COME BEGINNING LATE MONDAY NIGHT INTO TUESDAY AS WAVE LIFTS NORTHWEST AHEAD OF BOUNDARY. BEST FORCING REMAINS TO THE NORTH...BUT MODELS ARE BEGINNING TO FOCUS SLIGHTLY FURTHER SOUTH INTO NORTHWESTERN IOWA...AND HAVE TRENDED THIS WAY AS WELL. AGAIN...BEST CHANCE COMES WITH BOUNDARY PUSHING SOUTH FOR TUESDAY...AND MODELS ARE A BIT FASTER AND HAVE SPED UP PROGRESSION OF PRECIPITATION. MAY SEE CHANCES FOR HEAVY RAIN WITH PWAT VALUES NEAR 2 INCHES. BEHIND BOUNDARY...CONDITIONS WILL BE PRIMARILY CALM AND DRY WITH COOLER AIR PUSHING IN. TEMPERATURES WILL BE GENERALLY NEAR NORMAL WITH HIGHS IN THE MID 80S AND LOWS IN THE 50S AND 60S. NEXT BEST CHANCE FOR PRECIPITATION WILL COME NEAR END OF PERIOD FOR THE WEEKEND WITH WEAK BOUNDARY PUSHING SOUTH...THOUGH DO NOT HAVE HIGH CONFIDENCE IN TIMING OR PLACEMENT OF POPS ATTM. && .AVIATION...27/06Z ISSUED AT 1148 PM CDT SUN JUL 26 2015 SHORT TERM CONCERN...DURING THE CRITICAL TAF PERIOD...IS FOG POTENTIAL OVERNIGHT. HAVE INTRODUCED MVFR VSBYS AT THE TERMINALS OVERNIGHT...WITH KFOD...KMCW AND KALO AFFECTED THE MOST. HIGH-LEVEL CLOUDS FROM CONVECTION OVER SD/NE MAY TEMPER THE FOG HOWEVER. VFR FLIGHT CONDITIONS EXPECTED ON MONDAY. SHRA/TSRA MAY BE MOVING INTO/THROUGH NORTHWEST IOWA BY 06Z TUESDAY...AND POSSIBLY AFFECTING THE KFOD/KMCW TERMINALS...BUT HAVE LEFT THOSE TERMINALS DRY FOR NOW BECAUSE CONFIDENCE IS NOT HIGH ENOUGH ATTM TO INCLUDE VCTS/TSRA MENTION THERE. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...SMALL LONG TERM...AWB AVIATION...ZOGG
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
833 PM EDT Tue Jul 28 2015 ...Forecast Update... Issued at 830 PM EDT Tue Jul 28 2015 Issued another update to remove the pre-first period wording and to expand fog coverage. Soupy airmass in place along with winds expected to become light and variable soon should lead to at least areas of fog overnight. Quite the complex has formed to our west this evening, and the residual upper level disturbance may lead to an enhancement of showers storms toward daybreak, mainly west of the I-65 corridor. Thus will keep in the slight chances of storms we have there overnight. Issued at 545 PM EDT Tue Jul 28 2015 Did a grid update earlier this hour to account for current radar trends. Latest HRRR finally getting a handle on precip this afternoon, and it shows this precip decaying with sunset. Previous runs had the cells over central Illinois decaying immediately after model initialization, which has not occurred yet. Latest CIMSS NearCast does show the central part of our county warning area being a less likely place for storm development, and despite stronger outflows moving through that region, we only are seeing weak storms. Latest AMDAR data from a flight into SDF confirms this thinking, with a fairly strong cap above 600 mb that is limiting how tall the storms near SDF are getting. Despite that cap, the presence of these boundaries as well as a muggy airmass should keep non-severe storms forming over the next few hours until we can get the sun to set. Latest NAM still trying to show a wave of decaying storms coming in to our western forecast area toward daybreak. These would be from the cells now over Iowa as they round the top of the ridge over the mid MS valley. Made no changes to the daybreak period for now. .SHORT TERM (Now through Wednesday Night)... Issued at 325 PM EDT Tue Jul 28 2015 Scattered storms were ongoing across the area as of 19Z. Some storms were strong with lots of lightning, torrential rainfall, and gusty winds up to around 40 mph. Expect convection to continue through the evening hours as an upper level shortwave dropping SE out of IL keeps storms going or even enhances development this evening. With ample instability in place as well as DCAPE, high precipitable water values, and weak boundaries for storms to train along, a strong wind threat and localized flooding threat will continue through the evening hours. Storms should diminish through the late evening hours with the area becoming completely dry after midnight. Expect low temps in the low to mid 70s with some patchy fog/haze developing after midnight as it has done the past few mornings. For Wednesday, we`ll start the day with a dying complex of storms entering areas west of I-65. This morning batch should fizzle out or become just isld showers by mid morning. Some breaks in the clouds are expected during the morning and early afternoon hours allowing some instability to build. A cold front will approach the area Wed afternoon causing more convection to fire. Although morning clouds/precip may inhibit the environment somewhat and the front is pretty weak, we should still have enough forcing and instability to produce strong to marginally severe storms with strong winds, small hail, and torrential rainfall. Storms should persist through the evening before diminishing by late evening with the cold front passage. Highs for Wed should range through the upper 80s to lower 90s with heat index values in the lower 100s mainly west of I-65. The good news is any precip should provide relief from the heat tomorrow and there is a good chance for precip to occur 40-50%. Wed night low temps should range through upper 60s/lower 70s. .LONG TERM (Thursday through Tuesday)... Issued at 245 PM EDT Tue Jul 28 2015 The main forecast concern in the long term is temperatures as much of the extended forecast looks dry across the lower Ohio Valley. The start of the period /Thursday morning/ will feature a cold front bisecting the forecast area. A pool of high moisture along and ahead of the front combined with weak lift will support the chance of showers/storms during the morning hours across south-central Kentucky. The front then quickly drops into TN by 18z and in its wake, much drier and more pleasant conditions will build into the region. Plan on low humidity and more pleasant summer conditions Thursday afternoon through Friday as highs top out right around normal /mid to upper 80s/ and overnight lows will be in the low to mid 60s. Outside of scattered afternoon cumulus, skies look to be mostly sunny to sunny. A weak front approaches from the northwest on Saturday but will likely wash out before making it to the Ohio River. Humidity will slowly increase this weekend as dewpoints creep back up into the mid/upper 60s. Look for afternoon highs to gradually warm as well, approaching 90 degrees by Sunday. Going into next week, will continue to advertise a dry forecast as approaching fronts wash out or stall to the northwest. Some signals that a stronger front may make a push through the area mid to late week but model uncertainty is high. && .AVIATION (00Z TAF Update)... Updated 705 PM EDT Tue Jul 28 2015 Steamy conditions across the region. Threat for storms should end with the sun setting, and with the earlier rains at KBWG went ahead and pulled further storm chances this evening. Low level moisture plus some haze in the region should be enough to reduce vsby at the sites a little after midnight. Went with IFR tempo groups at KBWG and KLEX, as both received measurable rain this afternoon. There is a chance that further showers will arrive west of a KSDF/KBWG line by daybreak, but think they should be in a decaying phase at that point. Cold front/pre-frontal trough ahead of it should bring another shot at storms by late in the period for each site. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........RJS Short Term.....AMS Long Term......ZBT Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
710 PM EDT Tue Jul 28 2015 ...Updated Aviation Discussion... ...Forecast Update... Issued at 545 PM EDT Tue Jul 28 2015 Did a grid update earlier this hour to account for current radar trends. Latest HRRR finally getting a handle on precip this afternoon, and it shows this precip decaying with sunset. Previous runs had the cells over central Illinois decaying immediately after model initialization, which has not occurred yet. Latest CIMSS NearCast does show the central part of our county warning area being a less likely place for storm development, and despite stronger outflows moving through that region, we only are seeing weak storms. Latest AMDAR data from a flight into SDF confirms this thinking, with a fairly strong cap above 600 mb that is limiting how tall the storms near SDF are getting. Despite that cap, the presence of these boundaries as well as a muggy airmass should keep non-severe storms forming over the next few hours until we can get the sun to set. Latest NAM still trying to show a wave of decaying storms coming in to our western forecast area toward daybreak. These would be from the cells now over Iowa as they round the top of the ridge over the mid MS valley. Made no changes to the daybreak period for now. .SHORT TERM (Now through Wednesday Night)... Issued at 325 PM EDT Tue Jul 28 2015 Scattered storms were ongoing across the area as of 19Z. Some storms were strong with lots of lightning, torrential rainfall, and gusty winds up to around 40 mph. Expect convection to continue through the evening hours as an upper level shortwave dropping SE out of IL keeps storms going or even enhances development this evening. With ample instability in place as well as DCAPE, high precipitable water values, and weak boundaries for storms to train along, a strong wind threat and localized flooding threat will continue through the evening hours. Storms should diminish through the late evening hours with the area becoming completely dry after midnight. Expect low temps in the low to mid 70s with some patchy fog/haze developing after midnight as it has done the past few mornings. For Wednesday, we`ll start the day with a dying complex of storms entering areas west of I-65. This morning batch should fizzle out or become just isld showers by mid morning. Some breaks in the clouds are expected during the morning and early afternoon hours allowing some instability to build. A cold front will approach the area Wed afternoon causing more convection to fire. Although morning clouds/precip may inhibit the environment somewhat and the front is pretty weak, we should still have enough forcing and instability to produce strong to marginally severe storms with strong winds, small hail, and torrential rainfall. Storms should persist through the evening before diminishing by late evening with the cold front passage. Highs for Wed should range through the upper 80s to lower 90s with heat index values in the lower 100s mainly west of I-65. The good news is any precip should provide relief from the heat tomorrow and there is a good chance for precip to occur 40-50%. Wed night low temps should range through upper 60s/lower 70s. .LONG TERM (Thursday through Tuesday)... Issued at 245 PM EDT Tue Jul 28 2015 The main forecast concern in the long term is temperatures as much of the extended forecast looks dry across the lower Ohio Valley. The start of the period /Thursday morning/ will feature a cold front bisecting the forecast area. A pool of high moisture along and ahead of the front combined with weak lift will support the chance of showers/storms during the morning hours across south-central Kentucky. The front then quickly drops into TN by 18z and in its wake, much drier and more pleasant conditions will build into the region. Plan on low humidity and more pleasant summer conditions Thursday afternoon through Friday as highs top out right around normal /mid to upper 80s/ and overnight lows will be in the low to mid 60s. Outside of scattered afternoon cumulus, skies look to be mostly sunny to sunny. A weak front approaches from the northwest on Saturday but will likely wash out before making it to the Ohio River. Humidity will slowly increase this weekend as dewpoints creep back up into the mid/upper 60s. Look for afternoon highs to gradually warm as well, approaching 90 degrees by Sunday. Going into next week, will continue to advertise a dry forecast as approaching fronts wash out or stall to the northwest. Some signals that a stronger front may make a push through the area mid to late week but model uncertainty is high. && .AVIATION (00Z TAF Update)... Updated 705 PM EDT Tue Jul 28 2015 Steamy conditions across the region. Threat for storms should end with the sun setting, and with the earlier rains at KBWG went ahead and pulled further storm chances this evening. Low level moisture plus some haze in the region should be enough to reduce vsby at the sites a little after midnight. Went with IFR tempo groups at KBWG and KLEX, as both received measurable rain this afternoon. There is a chance that further showers will arrive west of a KSDF/KBWG line by daybreak, but think they should be in a decaying phase at that point. Cold front/pre-frontal trough ahead of it should bring another shot at storms by late in the period for each site. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........RJS Short Term.....AMS Long Term......ZBT Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
110 AM EDT Mon Jul 27 2015 ...Updated Aviation Discussion... ...Forecast Update... Issued at 945 PM EDT Sun Jul 26 2015 Weak cool front is expected to drop into the region overnight. Scattered thunderstorms have recently increased in coverage to our north and these will drift south and east into southern Indiana over the next few hours. For this forecast update, we did increase PoP chances across southern Indiana and northern Kentucky for the early overnight period. Rest of the forecast elements look OK at this time. .SHORT TERM (Now through Monday Night)... Issued at 304 PM EDT Sun Jul 26 2015 Given a weak cool front dropping in from the north, an outflow boundary from old convection coming in from the west, and a weak upper shortwave trof sliding across Illinois and Indiana, will need to retain small PoPs in the forecast this evening. HRRR has been doing fairly well with the convection thus far today and supports small PoPs as well. Convection chances will decrease during the overnight hours, with another muggy, still night in store. Guidance has been too warm with both highs and lows lately, so took lows to around 70 tonight. If we retain more cloud cover than currently expected, though, that forecast may indeed be too cool. On Monday what little is left of tonight`s cool front may still be lingering around the area, and outflow boundaries from overnight convection to our northwest may be present as well. Precipitable water values will pool around two inches and the low levels will become unstable enough to support convection. Mid-level lapse rates, though, will be quite weak and 7H temps will be warm. With the absence of a strong trigger and with the upper ridge building in, will keep PoPs low. High temps will be in the upper 80s to lower 90s. Any convection tomorrow will be diurnal and should dissipate with the setting of the sun, so will go dry for Monday night with warm, muggy conditions once again. .LONG TERM (Tuesday through Sunday)... Issued at 300 PM EDT Sun Jul 26 2015 Tuesday - Thursday... For mid week, we`ll be on the edge of an upper level ridge with a weak cold front progged to push southeast through the region late Wed/Wed night. Ahead of the front, scattered storms will be possible on Tues and Wed. Generally wind profiles look pretty weak although ample instability exists both days. For Tues, some mid level capping may help inhibit storm strength and coverage. Storms that do get going should be mainly heavy rainers with precipitable water amounts (PWATs) around or just over 2 inches and slow storm motions. Wed there will be slightly stronger winds and faster storm motions with high PWATs, so hopefully any heavy rainers will have some motion to them. Thursday some lingering showers and storms may occur early in the day over south central KY close to the front. Temperatures will be in the upper 80s to lower 90s for highs Tues-Thurs with the hottest day being Wed ahead of the front. Friday - Sunday... A dry end to the week looks likely behind the fropa with humidity values dropping as well. Highs will fall back into the mid 80s to around 90. && .AVIATION (06Z TAF Update)... Updated 108 AM EDT Mon Jul 27 2015 Scattered shower activity (and a rumble or two of thunder) will meander across the TAF sites through the overnight, although coverage will be pretty hit or miss. Will only include VCSH for a few hours. Main impacts overnight will be for ongoing haze and the potential for some fog through the pre-dawn hours. Cloudy skies don`t help confidence in just how low visibilities will go, but given the very moist low level atmosphere and some obs sites already MVFR, felt that some brief periods of IFR will be possible at BWG/LEX. Will keep SDF in MVFR toward dawn. A WSW wind will take hold through the daylight hours today, with variable cloudiness and some haze hanging around. There is also a chance for some isolated shower/storm coveage through the afternoon hours as a frontal boundary hangs in the area, however will only include at LEX for now. Winds will veer to NW and then variable as the front passes late afternoon evening. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........MJ Short Term.....13 Long Term......AMS Aviation.......BJS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1000 PM EDT TUE JUL 28 2015 .SYNOPSIS... HIGH PRESSURE REMAINS OFFSHORE THROUGH MIDWEEK...WITH THE NEXT COLD FRONT CROSSING THE AREA BY THURSDAY NIGHT. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... LATEST REGIONAL RADAR MOSAIC DEPICTS AREA OF SHOWERS PERSISTING OVER THE ERN VA PIEDMONT LATE THIS EVENING...REMAINING GENERALLY WEST OF THE LOCAL AREA. OTHERWISE...EARLIER SHOWERS/THUNDERSTORMS HAVE DISSIPATED OVER THE LOCAL AREA. SHORTWAVE VISIBLE ON GOES WV PROGGED TO DROP OVER ERN VA TONIGHT IN CONCERT WITH INCREASING WINDS ALOFT. A WARM/MOIST AIR MASS REMAINS IN PLACE OVER THE LOCAL AREA WITH DEWPOINTS IN THE 70S AND PWATS AROUND 2 INCHES. WILL MAINTAIN SLIGHT CHANCE-CHANCE POPS OVER THE PIEDMONT INTO CENTRAL VA AS RAP DEPICTS AN AXIS OF DEEP MOISTURE CONVERGENCE OVER THAT REGION. SKY AVERAGES PARTLY CLOUDY/MOSTLY CLOUDY INLAND AND MOSTLY CLEAR NE COUNTIES. LOWS IN THE LOW 70S. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... WEDNESDAY... UPPER LEVEL RIDGING CONTINUES TO EXPAND EASTWARD FROM THE SOUTHERN PLAINS. THIS WILL HELP TO LIMIT AFTN CONVECTION WHILE MAX TEMPS WARM A COUPLE OF DEGREES. HAVE CHC POPS (25-30%) ALONG AND WEST OF I-95. PARTLY SUNNY W/ HIGH TEMPS IN THE UPR 80S TO LOW 90S...WITH LOW/MID 80S AT THE BEACHES. MILD WED NIGHT W/ LOW TEMPS IN THE LOW/MID 70S. THURSDAY... UPR RIDGING RETROGRADES A BIT THURSDAY AS A TROUGH MOVES ACROSS THE GREAT LAKES AND PUSHES A COLD FRONT INTO THE MID-ATLANTIC REGION BY LATE IN THE DAY. DUE TO THE LATE ARRIVAL OF THE FRONT...CHC POPS (30-50%) WILL REMAIN ACROSS WESTERN AREAS DURING THE AFTN...LOWERING TO ~20% AT THE COAST. MAX TEMPS WILL REACH INTO THE UPR 80S TO LOW 90S...EXCEPT LOW/MID 80S AT THE IMMEDIATE COAST. THURSDAY NIGHT AND FRIDAY... THE COLD FRONT MOVES ACROSS THE FA THURSDAY NIGHT BEFORE STALLING ACROSS FAR SE VA AND THE EASTERN CAROLINAS ON FRIDAY. HAVE SOLID CHANCE POPS (30-50%) MOST AREAS WITH THE PASSAGE OF THE FRONT THRU MIDDAY FRI...THEN FOCUS CHC POPS ACROSS SE VA AND NE NC FRIDAY AFTN. DRY WX SHOULD RETURN TO NW AREAS BY LATE MORNING OR AFTERNOON. LOWS THU NIGHT IN THE 70S. HIGHS FRIDAY IN THE 80S TO AROUND 90. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... PATTERN BEGINS WITH A MID/UPPER LEVEL RIDGE CENTERED OVER THE SW CONUS AND AN UPPER LEVEL LOW PERSISTING ACRS HUDSON BAY CANADA. GFS/ECMWF INTO BETTER DECENT AGREEMENT THAT AN UPPER TROUGH AXIS WILL EXTEND SOUTH INTO THE GREAT LAKES SAT...THEN FLATTEN OUT SUN WITH A SHORTWAVE PUSHING ACRS THE MID ATLC BY MON. FRONT STALLS AND WEAKENS OVER FAR SRN VA/NC LATE FRI INTO THE WEEKEND. BEST CHC FOR PRECIP LOOKS TO BE ACRS THE FAR SOUTH/MAINLY NE NC THROUGH THE WEEKEND BUT EVEN HERE WILL ONLY GO WITH A 20-30% POPS/PRIMARILY FOR THE AFTN/EVENING TIMEFRAME (TAPERED TO 20% FAR SRN VA AND DRY ELSEWHERE). DID RAISE POPS A BIT FOR MON DUE TO THE SHORTWAVE MOVING THROUGH BUT NOT A LOT OF CONFIDENCE AS THIS IS 5-6 DAYS OUT SO WILL GENLY KEEP POPS ONLY AT 30-40% SOUTH TO 20% NORTH. KEEPING POPS AROUND 20% ALL AREAS TUE. TYPICAL SUMMERTIME TEMPERATURES CAN BE EXPECTED WITH HIGHS MAINLY RANGING FROM THE MID/UPPER 80S ALONG THE COAST TO THE UPPER 80S TO LOWER 90S INLAND. LOWS GENERALLY RANGING FROM THE MID 60S NW TO THE LWR 70S SE THROUGH THE PERIOD. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... THUNDERSTORMS HAVE COME TO AN END THIS EVENING WITH SCATTERED LIGHT TO MODERATE SHOWERS LEFT IN AREAS ALONG AND WEST OF INTERSTATE 95. SHOWERS WILL CONTINUE TO TAPER OFF AND SHOULD END BY 29/0400Z. DUE TO RECENT RAINFALL TODAY AT KRIC AND KSBY... SHALLOW GROUND FOG AND FEW-SCT CLOUDS AROUND 400FT ARE EXPECTED TO DEVELOP AFTER 29/0900Z AND PERSIST THROUGH 29/1200-1300Z BEFORE DISSIPATING. UPPER LEVEL RIDGING CONTINUES TO EXPAND EWD FROM THE SRN PLAINS ON WEDNESDAY. THIS WILL HELP TO LIMIT AFTN THUNDERSTORMS FOR THE ERN HALF OF THE AREA (INCLUDING TAF SITES KSBY/KPHF/KORF/KECG)... HOWEVER THERE IS JUST ENOUGH MOISTURE AND ENERGY WRAPPING AROUND THE UPPER RIDGE TO KEEP VCSH AT KRIC (INCLUDING AREAS ALONG AND WEST OF INTERSTATE 95). OVERALL SHEAR REMAINS VERY WEAK... THEREFORE THE MAIN THREAT WITH AFTN/EVENING THUNDERSTORMS WILL BE HEAVY RAINFALL CAUSING QUICK REDUCTIONS TO CIGS (MVFR) AND VISIBILITIES (LIFR TO IFR). A TROUGH CROSSES THE GREAT LAKES ON THURSDAY AND PUSHES A COLD FRONT INTO THE MID ATLANTIC REGION LATE IN THE DAY INTO THURSDAY NIGHT...THEN IT STALLS ACROSS FAR SE VA AND THE ERN CAROLINAS ON FRIDAY. MORE ORGANIZED THUNDERSTORMS SHOULD BE ANTICIPATED INVOF THIS FRONTAL BOUNDARY BOTH AFTNS/EVENINGS. && .MARINE... WEAK SFC HIGH PRESSURE IS CENTERED OFF THE COAST WITH WEAK SFC TROUGHING INLAND ACRS THE PIEDMONT AND COASTAL PLAIN. S/SE WINDS AVG 10-15 KT THIS EVENING/OVERNIGHT...AND WILL DROP OFF TO S/SW 5-10 KT WED MORNING. MODELS SUGGEST THAT WINDS MAY BE A LITTLE STRONGER LATE WED AFTN/WED NIGHT AS SFC/LEE TROUGH OVER VA DEEPENS SLIGHTLY AND HELPS S/SE WINDS AVG AROUND 15 KT IN THE BAY. COULD BE A FEW HRS WORTH OF 20 KT GUSTS IN THE BAY BUT TOO MARGINAL TO CONSIDER ANY SCA HEADLINES FOR NOW. WAVES GENLY 1-2 FT IN THE BAY BUT WILL PROBABLY BUILD TO 2-3 FT WED EVENING. SEAS 2-3 FT. A WEAK COLD FRONT APPROACHES THE WATERS LATE THU...THEN STALLS SOUTH OF THE AREA BY LATE IN THE WEEK. S/SE WINDS AVG 10-15 KT...TURNING SSW THU NIGHT. NOT A STRONG COOL SURGE ON FRI AS WINDS SHIFT TO THE NORTH WITH THE FRONT DISSIPATING OVER SRN VA/ERN NC SO WILL KEEP WINDS IN THE 10-15 KT RANGE. FLOW GRADUALLY SHIFTS TO E/SE INTO THE WEEKEND WITH WAVES 1-2 FT/SEAS 2-4 FT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...JDM NEAR TERM...JDM/SAM SHORT TERM...JDM LONG TERM...LKB AVIATION...BMD MARINE...LKB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 PM EDT MON JUL 27 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 359 PM EDT MON JUL 27 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH INTO THE NW CONUS AND A RIDGE FROM THE SRN PLAINS THROUGH THE WRN LAKES INTO NRN ONTARIO. AT THE SFC...SRLY WINDS PREVAILED FROM THE DAKOTAS INTO MN BETWEEN HIGH PRES OVER THE CNTREL GREAT LAKES AND A TROUGH OVER ERN MT/WY. ISOLD SHOWERS THAT HAD DEVELOPED ON THE LAKE SUPERIOR BREEZE BOUNDARY FROM NEAR SAW TO ERY HAVE DISIPATED. OTHERWISE...MOSTLY SUNNY SKIES PREAVILED WITH TEMPS INTO THE UPER 80S INLAND AND AROUND 80 ALONG THE GREAT LAKES SHORELINES. A MID LEVEL LOW OVER MONTANA TONIGHT IS EXPECTED TO LIFT TO THE NE INTO THE SW CORNER OF MANITOBA BY TUE EVENING. CONVECTION IS EXPECTED TO DEVELOP OVER THE ERN DAKOTAS INTO SRN MN TONIGHT THAT MAY GENERATE AN MCV THAT COULD SPREAD CLOUDS AND DIMINISHING SHRA/TSRA INTO WEST UPPER MI TUE MORNING AND POSSIBLY INTO THE AFTRNOON. EVEN THOUGH THE CLOUDS MAY HOLD DOWN HEATING EARLY...EXPECT ENOUGH SUNSHINE BY AFTERNOON TO PUSH TEMPS INTO THE UPPER 80S. WITH DEWPOINTS IN THE LOWER 60S WHICH HAVE TRENDED LOWER COMPARED TO PREVIOUS FCSTS ...EXPECT CAPPING WILL REMAIN STRONG ENOUGH OVER MOST OF THE CWA TO PREVENT ANY SHRA/TSRA FROM DEVELOPING. SINCE THERE IS LINGERING UNCERTAINTY WITH THE IMPACT OF THE CONVECTION FROM EARLIER IN THE DAY...CONTINUED TO MENTION LOWER END CHANCE POPS OVER THE WEST. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 352 PM EDT MON JUL 27 2015 BY 00Z WEDNESDAY SHOWERS AND THUNDERSTORMS WILL BE OVER W LAKE SUPERIOR AND FAR W UPPER MI...EXTENDING THROUGH THROUGH W AND CENTRAL WI. THIS WILL BE THE RESULT OF THE STRONG LOW SHIFTING NE ACROSS S CENTRAL CANADA...SITUATED OVER S MANITOBA AT 00Z WEDNESDAY. THE WRAPPED UP LOW WILL LIKELY FEATURE AN OCCLUDED FRONT STRETCHING THROUGH FAR W ONTARIO...BEFORE SWITCHING BACK TO A WARM FRONT OVER W UPPER MI AND A COLD FRONT OVER ORIENTED S THROUGH FAR W LAKE SUPERIOR. SHOWERS AND THUNDERSTORMS WILL BE LIKELY AHEAD OF THE COLD FRONT. EXPECT THE COLD FRONT TO PUSH OVER W UPPER MI BY 06Z...STRETCH FROM AROUND MARQUETTE AND ALGER COUNTIES DOWN THROUGH DELTA COUNTY BY 12Z...AND E OF UPPER MI BY 18Z WEDNESDAY. STILL LOOKS LIKE A THIN LINE OF CONVECTION...TO START OUT THE EVENING. FCST MODELS CONTINUE TO FOLLOW THE IDEA OF THE S STORMS RETAINING THEIR CONVECTIVE LOOK AND E PROGRESSION...WHILE UPPER MI MAY HAVE A FEW MORE BREAKS. LIKE HOW THE SPC CONVECTIVE OUTLOOKS HAVE FOLLOWED THIS TREND. HEAVY RAIN STILL LOOKS TO BE THE MAIN THREAT AS PW VALUES INCREASE TO NEAR 2IN OVER THE W HALF PRIOR TO 09Z WEDNESDAY...AND OVER THE E HALF OF UPPER MI 09-15Z WEDNESDAY. OTHERWISE WEDNESDAY WILL BE 5-10F COOLER THAN MONDAY AND TUESDAY AS MUCH DRIER AIR WORK IN BEHIND THE COLD FRONT. PW VALUES QUICKLY FALL TO 0.75IN OVER THE W HALF BY 15Z WEDNESDAY...BEFORE MODERATING TO AROUND 1IN IN THE AFTERNOON AS THE 500MB LOW OVER THE W HALF OF ONTARIO SHIFTS A TROUGH OVER THE AREA. THE ADDITION OF A FEW AFTERNOON HOURS W WILL NOT BE OUT OF THE QUESTION...AS WELL AS INCREASED WINDS. A W-WNW 30-50KT 850MB JET WILL QUICKLY SWING THROUGH MID AFTERNOON INTO THE EVENING. WENT TOWARDS THE LOWER END OF GUIDANCE TO DEW POINTS...WITH HUMIDITY VALUES BOTTOMING OUT NEAR 40 PERCENT CENTRAL IN THE AFTERNOON. THE TEMPERATURE RELIEF...BACK TO SEASONAL NORMAL VALUES...WILL CONTINUE THROUGH AT LEAST THE REST OF THE WORK WEEK. DRY AIR SHOULD REMAIN IN CONTROL OF MUCH OF THE AREA THROUGH FRIDAY AS THE 500MB LOW PUSHES ACROSS HUDSON BAY. IF WE DO GET ANY PRECIP IT WOULD LIKELY BE OVER LAKE SUPERIOR...AS SEVERAL WAVE ROTATE AROUND THE LOW IN W-NW FLOW. HIGHS WILL REMAIN IN THE 70S TO MID 80S...WARMEST S CENTRAL. A STRONGER WAVE ROTATING THROUGH THE STEADY SFC-500MB LOW OVER HUDSON BAY SHOULD SWEEP A COLD FRONT ACROSS UPPER MI SATURDAY NIGHT. AT THIS DISTANCE THERE ARE A FEW DISCREPANCIES ON STRENGTH AND TIMING...BUT ENOUGH CONFIDENCE FOR HIGH CHANCE POPS SATURDAY NIGHT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 141 PM EDT MON JUL 27 2015 HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH TONIGHT WITH VFR CONDITIONS EXPECTED. ALTHOUGH SOME SHOWERS OR REMNANTS OF OVERNIGHT CONVECTION OVER MN MAY MOVE INTO WESTERN UPPER MICHIGAN TUE MORNING. HOWEVER...WITH ONLY A LOW PROBABILITY OF MAINLY JUST WEAKENING SHOWERS...NO PCPN WAS INCLUDED IN THE FCST AS VFR CONDITIONS PERSIST. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 359 PM EDT MON JUL 27 2015HIGH PRESSURE OVER LOWER MI WILL KEEP A RIDGE ACROSS LAKE SUPERIOR THROUGH EARLY TUESDAY...ALONG WITH THE POTENTIAL FOR PATCHY FOG. DEEPENING LOW PRESSURE OVER S SASKATCHEWAN TUESDAY MORNING WILL RACE ACROSS MANITOBA TUESDAY NIGHT...AND ACROSS ONTARIO TO HUDSON BAY WEDNESDAY NIGHT. LOOK FOR THIS LOW TO REMAIN ACROSS HUDSON BAY THROUGH AT LEAST FRIDAY. THE RESULT WILL BE A TROUGH EXTENDING DOWN THROUGH LAKE SUPERIOR TUESDAY NIGHT AND WEDNESDAY...ALONG WITH THE RETURN OF STRONGER WINDS. S-SW WINDS AHEAD OF THE TROUGH COULD GUST NEAR 25KTS OVER MAINLY E LAKE SUPERIOR TUE NIGHT...WITH SW-W WINDS AROUND 30KTS WEDNESDAY INTO WEDNESDAY EVENING IN THE WAKE OF THE TROUGH. THERE MAY BE SOME GALE FORCE GUSTS BY MIDDAY WED OVER THE WRN LAKE. THE TROUGH WILL SHIFT TO THE NEW ENGLAND STATES THURSDAY...ALLOWING A WEAK RIDGE TO BUILD INTO THE UPPER GREAT LAKES THURSDAY. IT WILL QUICKLY BE REPLACED BY A WEAK TROUGH THURSDAY NIGHT INTO FRIDAY...ROTATING AROUND THE HUDSON BAY LOW. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KF AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1248 PM CDT MON JUL 27 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 355 AM CDT MON JUL 27 2015 CONVECTION JUST REFUSES TO DIE OVER THE CWA, WITH HIT AND MISS ECHOES SHOWING UP THROUGHOUT THE PREDAWN HOURS IN A BROAD BAND ALONG THE MISSISSIPPI RIVER. LARGEST AND MOST PERSISTENT AREA OF PRECIP HAS BEEN OVER OUR SE COUNTIES SOUTHEAST OF STL METRO, WHERE IT APPEARS VERY WEAK WAA INTERACTING WITH CONTINUALLY RAIN-COOLED BOUNDARY IS ALLOWING CONVECTION TO REGENERATE. IN SPITE OF THE INTENSIFICATION OF THE UPPER RIDGE ACROSS THE AREA TODAY THE VARIOUS HI-RES EXPLICIT MODELS CONTINUE TO GENERATE SPOTTY CONVECTION OVER ALL BUT OUR FAR WESTERN COUNTIES, AND JUDGING HOW THERMAL PROFILE OF AMS IS NEARLY UNCHANGED CARRYING SOME LOW/SLIGHT CHANCE POPS LOOKS APPROPRIATE. HAVE PLACED HIGHEST POPS...SUCH AS THEY ARE...NEAR WEAK SURFACE BOUNDARY SUGGESTED AT BY NAM AND RUC FROM N OF COU THRU STL AREA. WITHOUT FAIRLY EXTENSIVE MORNING PRECIP, TEMPERATURES ACROSS MOST OF THE AREA SHOULD WARM NICELY TODAY. THERE IS EXTENSIVE UPSTREAM CIRRUS FROM CONVECTION OVER THE PLAINS, BUT IT SHOULD CERTAINLY THIN AS CONVECTION WANES AND AS THE HIGH LEVEL MOISTURE DRIFTS INTO THE HEART OF THE RIDGE, AND HIGHS SHOULD EASILY REACH THE LOW TO MID 90S. DEWPOINTS ARE ALREADY WELL IN THE 70S, AND AFOREMENTIONED BOUNDARY MAY ALLOW FOR FURTHER POOLING OF THIS LOW LEVEL MOISTURE DURING THE AFTERNOON. SO, ALL PARAMETERS POINT TO A VERY STEAMY JULY AFTERNOON, WITH THE HEAT INDEX REACHING 105 DEGREES OVER MOST OF THE CWA. GOING HEAT ADVISORY STILL LOOKS ON THE MARK. TRUETT .LONG TERM: (TONIGHT THROUGH SUNDAY) ISSUED AT 355 AM CDT MON JUL 27 2015 (TONIGHT-WEDNESDAY) HIGH LEVELS OF HEAT AND HUMIDITY WILL CONTINUE TONIGHT INTO TUESDAY. HIGHS ON TUESDAY WILL LIKELY REACH THEIR HIGHEST LEVELS DURING THIS RECENT STRETCH OF ABOVE NORMAL TEMPERATURES, WITH MID 90S COMMON ACROSS MOST OF THE CWA. HEAT INDEX VALUES SHOULD RATCHET UP A NOTCH FROM TODAY`S LEVELS, WITH FORECAST COMBO OF HOURLY TEMPS/DEWPOINTS YIELDING VALUES IN THE 105-110 RANGE ACROSS THE REGION. ITS POSSIBLE THAT A FEW LOCATIONS OVER SOUTHEAST PARTS OF THE FA COULD ONCE AGAIN PUSH HEAT INDEX VALUES AROUND 105 ON WEDNESDAY BUT THREAT LOOKS LOW AT THIS POINT...SO WILL MAINTAIN TIMING AND LOCATION OF CURRENT HEAT ADVISORY FOR NOW. CONTINUED AMPLIFICATION OF UPPER RIDGE OVER THE MID MISSISSIPPI VALLEY SUGGESTS THAT THREAT OF CONVECTION SHOULD WANE EVEN MORE TONIGHT AND TUESDAY. HAVE MAINTAINED SOME VERY LOW POPS THIS EVENING...PRIMARILY FOR ANY LEFT-OVER AFTERNOON ACTIVITY...AND ALSO CONTINUED SOME LOW POPS IN OUR FAR EASTERN COUNTIES ON TUESDAY WHERE MID LEVEL TEMPS WILL BE THEIR COOLEST. OVERNIGHT MODEL SOLUTIONS ARE STILL BRINGING A COLD FRONT ACROSS THE REGION LATE TUESDAY NIGHT AND INTO WEDNESDAY. BELIEVE THIS MAY BE ONE OF THOSE SITUATIONS WHERE THERE IS A BROAD BAND OF CONVECTION THAT IGNITES ALONG THE COLD FRONT TUESDAY NIGHT, WITH THIS BAND OF PRECIP HAVING TROUBLE WORKING SOUTH AS COLD FRONT...PERHAPS ENHANCED BY OUTFLOW...OUTRUNS THE UPPER LEVEL SHORTWAVE ON WEDNESDAY. ADDITIONAL DEVELOPMENT FURTHER SOUTH ALSO LOOKS QUESTIONABLE DURING THE DAY ON WEDNESDAY...AS CURRENT FORECASTS INDICATE VERY LITTLE SURFACE CONVERGENCE ALONG THE SURFACE BOUNDARY. (THURSDAY-SUNDAY) ALL MEDIUM RANGE SOLUTIONS SUGGEST UPPER LEVEL TROF DEVELOPING OVER THE EASTERN CONUS DURING THE LATTER HALF OF THE WEEK, WHILE HEIGHTS AND UPPER LEVEL RIDGE GRADUALLY RETROGRADES INTO THE WESTERN U.S. ALTHOUGH NORTHWEST FLOW CAN BE SUBTLY STORMY, GUIDANCE SUGGESTS A GENERALLY TRANQUIL WEATHER PATTERN FOR OUR AREA FOR THE LAST PART OF THE WEEK. TEMPERATURES WILL BE SEASONAL, BUT THERE SHOULD BE NOTICEABLYLESS HUMIDITY WITH DEWPOINTS PRIMARILY IN THE 60S. DID STAY WITH MODEL CONSENSUS THAT SUGGESTS SHORTWAVE AND ASSOCIATED COLD FRONT PRODUCING A CHANCE FOR THUNDERSTORMS BY SUNDAY IN SOME AREAS. TRUETT && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1243 PM CDT MON JUL 27 2015 WARM FRONTAL BOUNDARY IS LINGERING JUST NORTH OF I70 CORRIDOR AND SHOULD CONTINUE TO SLOWLY MOVE NORTH THIS AFTERNOON BEFORE STALLING OUT JUST EAST OF MISSISSIPPI RIVER. IN THE MEANTIME, DIURNAL CU WITH SOME HIGH THIN CIRRUS THROUGH THE FORECAST PERIOD. AS FOR WINDS, TO REMAIN LIGHT AND VARIABLE BEFORE PICKING UP A BIT FROM THE SOUTH TO SOUTHWEST FOR TAF SITES ALONG I70 BY TUESDAY MORNING, WHILE KUIN WILL REMAIN CLOSE TO BOUNDARY AND SEE EAST TO SOUTHEAST WINDS. ISOLATED STORMS POSSIBLE BUT HARD TO PIN DOWN IF THEY WILL AFFECT TAF SITES, SO LEFT MENTION OUT FOR NOW. SPECIFICS FOR KSTL: WARM FRONTAL BOUNDARY IS LINGERING JUST NORTH OF I70 CORRIDOR AND SHOULD CONTINUE TO SLOWLY MOVE NORTH THIS AFTERNOON BEFORE STALLING OUT JUST EAST OF MISSISSIPPI RIVER. IN THE MEANTIME, DIURNAL CU WITH SOME HIGH THIN CIRRUS THROUGH THE FORECAST PERIOD. AS FOR WINDS, TO REMAIN LIGHT AND VARIABLE BEFORE PICKING UP A BIT FROM THE SOUTH TO SOUTHWEST BY 15Z TUESDAY. ISOLATED STORMS POSSIBLE BUT HARD TO PIN DOWN IF THEY WILL AFFECT METRO AREA, SO LEFT MENTION OUT FOR NOW. BYRD && .LSX WATCHES/WARNINGS/ADVISORIES: MO...HEAT ADVISORY UNTIL 9 PM CDT TUESDAY 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-STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. IL...HEAT ADVISORY UNTIL 9 PM CDT TUESDAY FOR ADAMS IL-BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL- MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL- PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
643 AM CDT MON JUL 27 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 355 AM CDT MON JUL 27 2015 CONVECTION JUST REFUSES TO DIE OVER THE CWA, WITH HIT AND MISS ECHOES SHOWING UP THROUGHOUT THE PREDAWN HOURS IN A BROAD BAND ALONG THE MISSISSIPPI RIVER. LARGEST AND MOST PERSISTENT AREA OF PRECIP HAS BEEN OVER OUR SE COUNTIES SOUTHEAST OF STL METRO, WHERE IT APPEARS VERY WEAK WAA INTERACTING WITH CONTINUALLY RAIN-COOLED BOUNDARY IS ALLOWING CONVECTION TO REGENERATE. IN SPITE OF THE INTENSIFICATION OF THE UPPER RIDGE ACROSS THE AREA TODAY THE VARIOUS HI-RES EXPLICIT MODELS CONTINUE TO GENERATE SPOTTY CONVECTION OVER ALL BUT OUR FAR WESTERN COUNTIES, AND JUDGING HOW THERMAL PROFILE OF AMS IS NEARLY UNCHANGED CARRYING SOME LOW/SLIGHT CHANCE POPS LOOKS APPROPRIATE. HAVE PLACED HIGHEST POPS...SUCH AS THEY ARE...NEAR WEAK SURFACE BOUNDARY SUGGESTED AT BY NAM AND RUC FROM N OF COU THRU STL AREA. WITHOUT FAIRLY EXTENSIVE MORNING PRECIP, TEMPERATURES ACROSS MOST OF THE AREA SHOULD WARM NICELY TODAY. THERE IS EXTENSIVE UPSTREAM CIRRUS FROM CONVECTION OVER THE PLAINS, BUT IT SHOULD CERTAINLY THIN AS CONVECTION WANES AND AS THE HIGH LEVEL MOISTURE DRIFTS INTO THE HEART OF THE RIDGE, AND HIGHS SHOULD EASILY REACH THE LOW TO MID 90S. DEWPOINTS ARE ALREADY WELL IN THE 70S, AND AFOREMENTIONED BOUNDARY MAY ALLOW FOR FURTHER POOLING OF THIS LOW LEVEL MOISTURE DURING THE AFTERNOON. SO, ALL PARAMETERS POINT TO A VERY STEAMY JULY AFTERNOON, WITH THE HEAT INDEX REACHING 105 DEGREES OVER MOST OF THE CWA. GOING HEAT ADVISORY STILL LOOKS ON THE MARK. TRUETT .LONG TERM: (TONIGHT THROUGH SUNDAY) ISSUED AT 355 AM CDT MON JUL 27 2015 (TONIGHT-WEDNESDAY) HIGH LEVELS OF HEAT AND HUMIDITY WILL CONTINUE TONIGHT INTO TUESDAY. HIGHS ON TUESDAY WILL LIKELY REACH THEIR HIGHEST LEVELS DURING THIS RECENT STRETCH OF ABOVE NORMAL TEMPERATURES, WITH MID 90S COMMON ACROSS MOST OF THE CWA. HEAT INDEX VALUES SHOULD RATCHET UP A NOTCH FROM TODAY`S LEVELS, WITH FORECAST COMBO OF HOURLY TEMPS/DEWPOINTS YIELDING VALUES IN THE 105-110 RANGE ACROSS THE REGION. ITS POSSIBLE THAT A FEW LOCATIONS OVER SOUTHEAST PARTS OF THE FA COULD ONCE AGAIN PUSH HEAT INDEX VALUES AROUND 105 ON WEDNESDAY BUT THREAT LOOKS LOW AT THIS POINT...SO WILL MAINTAIN TIMING AND LOCATION OF CURRENT HEAT ADVISORY FOR NOW. CONTINUED AMPLIFICATION OF UPPER RIDGE OVER THE MID MISSISSIPPI VALLEY SUGGESTS THAT THREAT OF CONVECTION SHOULD WANE EVEN MORE TONIGHT AND TUESDAY. HAVE MAINTAINED SOME VERY LOW POPS THIS EVENING...PRIMARILY FOR ANY LEFT-OVER AFTERNOON ACTIVITY...AND ALSO CONTINUED SOME LOW POPS IN OUR FAR EASTERN COUNTIES ON TUESDAY WHERE MID LEVEL TEMPS WILL BE THEIR COOLEST. OVERNIGHT MODEL SOLUTIONS ARE STILL BRINGING A COLD FRONT ACROSS THE REGION LATE TUESDAY NIGHT AND INTO WEDNESDAY. BELIEVE THIS MAY BE ONE OF THOSE SITUATIONS WHERE THERE IS A BROAD BAND OF CONVECTION THAT IGNITES ALONG THE COLD FRONT TUESDAY NIGHT, WITH THIS BAND OF PRECIP HAVING TROUBLE WORKING SOUTH AS COLD FRONT...PERHAPS ENHANCED BY OUTFLOW...OUTRUNS THE UPPER LEVEL SHORTWAVE ON WEDNESDAY. ADDITIONAL DEVELOPMENT FURTHER SOUTH ALSO LOOKS QUESTIONABLE DURING THE DAY ON WEDNESDAY...AS CURRENT FORECASTS INDICATE VERY LITTLE SURFACE CONVERGENCE ALONG THE SURFACE BOUNDARY. (THURSDAY-SUNDAY) ALL MEDIUM RANGE SOLUTIONS SUGGEST UPPER LEVEL TROF DEVELOPING OVER THE EASTERN CONUS DURING THE LATTER HALF OF THE WEEK, WHILE HEIGHTS AND UPPER LEVEL RIDGE GRADUALLY RETROGRADES INTO THE WESTERN U.S. ALTHOUGH NORTHWEST FLOW CAN BE SUBTLY STORMY, GUIDANCE SUGGESTS A GENERALLY TRANQUIL WEATHER PATTERN FOR OUR AREA FOR THE LAST PART OF THE WEEK. TEMPERATURES WILL BE SEASONAL, BUT THERE SHOULD BE NOTICEABLYLESS HUMIDITY WITH DEWPOINTS PRIMARILY IN THE 60S. DID STAY WITH MODEL CONSENSUS THAT SUGGESTS SHORTWAVE AND ASSOCIATED COLD FRONT PRODUCING A CHANCE FOR THUNDERSTORMS BY SUNDAY IN SOME AREAS. TRUETT && .AVIATION: (FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 635 AM CDT MON JUL 27 2015 ISOLATED SH/TS ARE POSSIBLE TODAY AT ALL TERMINALS, BUT CONFIDENCE IN SH/TS AT ANY GIVEN TERMINAL IS TOO LOW TO INCLUDE IN THE 12Z TAFS ATTM. EARLY MORNING FOG IN RIVER VALLEYS SHOULD BEGIN TO DISSIPATE WITH THE ONSET OF DIURNAL MIXING OVER THE NEXT FEW HOURS. THE AIR MASS TONIGHT WILL BE VERY SIMILAR TO CONDITIONS LAST NIGHT, THEREFORE FOG FOG OUGHT TO RE-DEVELOP AFTER 04Z TONIGHT (ESPECIALLY IN RIVER VALLEYS) GIVEN THE SIMILAR T-TD SPREADS AND LIGHT WINDS. KANOFSKY && .LSX WATCHES/WARNINGS/ADVISORIES: MO...HEAT ADVISORY FROM NOON TODAY TO 9 PM CDT TUESDAY FOR AUDRAIN MO- CRAWFORD MO-FRANKLIN MO-GASCONADE MO-IRON MO-JEFFERSON MO- KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-MARION MO-MONROE MO- MONTGOMERY MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO- STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. HEAT ADVISORY UNTIL 9 PM CDT TUESDAY FOR BOONE MO-CALLAWAY MO- COLE MO-MONITEAU MO-OSAGE MO. IL...HEAT ADVISORY FROM NOON TODAY TO 9 PM CDT TUESDAY FOR ADAMS IL- BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL- JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL- MONTGOMERY IL-PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
403 AM CDT MON JUL 27 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 355 AM CDT MON JUL 27 2015 CONVECTION JUST REFUSES TO DIE OVER THE CWA, WITH HIT AND MISS ECHOES SHOWING UP THROUGHOUT THE PREDAWN HOURS IN A BROAD BAND ALONG THE MISSISSIPPI RIVER. LARGEST AND MOST PERSISTENT AREA OF PRECIP HAS BEEN OVER OUR SE COUNTIES SOUTHEAST OF STL METRO, WHERE IT APPEARS VERY WEAK WAA INTERACTING WITH CONTINUALLY RAIN-COOLED BOUNDARY IS ALLOWING CONVECTION TO REGENERATE. IN SPITE OF THE INTENSIFICATION OF THE UPPER RIDGE ACROSS THE AREA TODAY THE VARIOUS HI-RES EXPLICIT MODELS CONTINUE TO GENERATE SPOTTY CONVECTION OVER ALL BUT OUR FAR WESTERN COUNTIES, AND JUDGING HOW THERMAL PROFILE OF AMS IS NEARLY UNCHANGED CARRYING SOME LOW/SLIGHT CHANCE POPS LOOKS APPROPRIATE. HAVE PLACED HIGHEST POPS...SUCH AS THEY ARE...NEAR WEAK SURFACE BOUNDARY SUGGESTED AT BY NAM AND RUC FROM N OF COU THRU STL AREA. WITHOUT FAIRLY EXTENSIVE MORNING PRECIP, TEMPERATURES ACROSS MOST OF THE AREA SHOULD WARM NICELY TODAY. THERE IS EXTENSIVE UPSTREAM CIRRUS FROM CONVECTION OVER THE PLAINS, BUT IT SHOULD CERTAINLY THIN AS CONVECTION WANES AND AS THE HIGH LEVEL MOISTURE DRIFTS INTO THE HEART OF THE RIDGE, AND HIGHS SHOULD EASILY REACH THE LOW TO MID 90S. DEWPOINTS ARE ALREADY WELL IN THE 70S, AND AFOREMENTIONED BOUNDARY MAY ALLOW FOR FURTHER POOLING OF THIS LOW LEVEL MOISTURE DURING THE AFTERNOON. SO, ALL PARAMETERS POINT TO A VERY STEAMY JULY AFTERNOON, WITH THE HEAT INDEX REACHING 105 DEGREES OVER MOST OF THE CWA. GOING HEAT ADVISORY STILL LOOKS ON THE MARK. TRUETT .LONG TERM: (TONIGHT THROUGH SUNDAY) ISSUED AT 355 AM CDT MON JUL 27 2015 (TONIGHT-WEDNESDAY) HIGH LEVELS OF HEAT AND HUMIDITY WILL CONTINUE TONIGHT INTO TUESDAY. HIGHS ON TUESDAY WILL LIKELY REACH THEIR HIGHEST LEVELS DURING THIS RECENT STRETCH OF ABOVE NORMAL TEMPERATURES, WITH MID 90S COMMON ACROSS MOST OF THE CWA. HEAT INDEX VALUES SHOULD RATCHET UP A NOTCH FROM TODAY`S LEVELS, WITH FORECAST COMBO OF HOURLY TEMPS/DEWPOINTS YIELDING VALUES IN THE 105-110 RANGE ACROSS THE REGION. ITS POSSIBLE THAT A FEW LOCATIONS OVER SOUTHEAST PARTS OF THE FA COULD ONCE AGAIN PUSH HEAT INDEX VALUES AROUND 105 ON WEDNESDAY BUT THREAT LOOKS LOW AT THIS POINT...SO WILL MAINTAIN TIMING AND LOCATION OF CURRENT HEAT ADVISORY FOR NOW. CONTINUED AMPLIFICATION OF UPPER RIDGE OVER THE MID MISSISSIPPI VALLEY SUGGESTS THAT THREAT OF CONVECTION SHOULD WANE EVEN MORE TONIGHT AND TUESDAY. HAVE MAINTAINED SOME VERY LOW POPS THIS EVENING...PRIMARILY FOR ANY LEFT-OVER AFTERNOON ACTIVITY...AND ALSO CONTINUED SOME LOW POPS IN OUR FAR EASTERN COUNTIES ON TUESDAY WHERE MID LEVEL TEMPS WILL BE THEIR COOLEST. OVERNIGHT MODEL SOLUTIONS ARE STILL BRINGING A COLD FRONT ACROSS THE REGION LATE TUESDAY NIGHT AND INTO WEDNESDAY. BELIEVE THIS MAY BE ONE OF THOSE SITUATIONS WHERE THERE IS A BROAD BAND OF CONVECTION THAT IGNITES ALONG THE COLD FRONT TUESDAY NIGHT, WITH THIS BAND OF PRECIP HAVING TROUBLE WORKING SOUTH AS COLD FRONT...PERHAPS ENHANCED BY OUTFLOW...OUTRUNS THE UPPER LEVEL SHORTWAVE ON WEDNESDAY. ADDITIONAL DEVELOPMENT FURTHER SOUTH ALSO LOOKS QUESTIONABLE DURING THE DAY ON WEDNESDAY...AS CURRENT FORECASTS INDICATE VERY LITTLE SURFACE CONVERGENCE ALONG THE SURFACE BOUNDARY. (THURSDAY-SUNDAY) ALL MEDIUM RANGE SOLUTIONS SUGGEST UPPER LEVEL TROF DEVELOPING OVER THE EASTERN CONUS DURING THE LATTER HALF OF THE WEEK, WHILE HEIGHTS AND UPPER LEVEL RIDGE GRADUALLY RETROGRADES INTO THE WESTERN U.S. ALTHOUGH NORTHWEST FLOW CAN BE SUBTLY STORMY, GUIDANCE SUGGESTS A GENERALLY TRANQUIL WEATHER PATTERN FOR OUR AREA FOR THE LAST PART OF THE WEEK. TEMPERATURES WILL BE SEASONAL, BUT THERE SHOULD BE NOTICIABLY LESS HUMIDITY WITH DEWPOINTS PRIMARILY IN THE 60S. DID STAY WITH MODEL CONSENSUS THAT SUGGESTS SHORTWAVE AND ASSOCIATED COLD FRONT PRODUCING A CHANCE FOR THUNDERSTORMS BY SUNDAY IN SOME AREAS. TRUETT && .AVIATION: (FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1105 PM CDT SUN JUL 26 2015 ISOLATE TO SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP...NORTHEAST AND TO THE SOUTH OF STL. THIS MOST LIKELY FROM SOME OUTFLOW BOUNDARIES AND SOME ISENTROPIC LIFT WITH THE 850 MB WIND. WIND BEGINS TO BECOME MORE PARALLEL TO THE FLOW BY 06Z AND FINISHED THE PROCESS BY 12Z. WOULD NOT BE SURPRISED TO SEE CONTINUED SPOTTER DEVELOPMENT FOR SEVERAL HOURS YET. THE LATEST HRRR-CR AGREES WITH THIS SCENARIO AND PLACEMENT PRETTY WELL. PRIMARY MODELS DEVELOP SCATTERED ACTIVITY MONDAY AFTERNOON...BUT WITH VERY LOW POPS IN THE FORECAST WILL GO WITH A DRY FORECAST. WITH LIGHT WIND AND RECENT RAIN AT MOST LOCATIONS WILL GO WITH A TEMPO FOR A COUPLE HOURS OF MORING FOG. SPECIFICS FOR KSTL: ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE IN THE AREA. DEPENDING ON LOCATION...MAY CONTINUE THE VCTS A COUPLE MORE HOURS BEYOND 06Z. A LITTLE CONCERNED WITH POSSIBLE FOG IN THE MORNING GIVEN RECENT RAIN. AS USUAL THE MET GUIDANCE HITS CIG/VIS HARD WITH THE MAV VFR. WILL GO AHEAD AND THROW IN A TEMPO FOR A COUPLE OF HOURS MONDAY MORNING. JPK && .PRELIMINARY POINT TEMPS/POPS: SAINT LOUIS 94 80 97 81 / 20 20 10 20 QUINCY 91 75 94 74 / 20 20 10 30 COLUMBIA 94 76 96 75 / 10 10 10 20 JEFFERSON CITY 95 76 98 76 / 10 10 10 20 SALEM 91 75 93 77 / 20 20 20 20 FARMINGTON 92 75 94 76 / 20 20 10 20 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...HEAT ADVISORY FROM NOON TODAY TO 9 PM CDT TUESDAY FOR AUDRAIN MO- CRAWFORD MO-FRANKLIN MO-GASCONADE MO-IRON MO-JEFFERSON MO- KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-MARION MO-MONROE MO- MONTGOMERY MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO- STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. HEAT ADVISORY UNTIL 9 PM CDT TUESDAY FOR BOONE MO-CALLAWAY MO- COLE MO-MONITEAU MO-OSAGE MO. IL...HEAT ADVISORY FROM NOON TODAY TO 9 PM CDT TUESDAY FOR ADAMS IL- BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL- JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL- MONTGOMERY IL-PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1116 PM CDT SUN JUL 26 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 328 PM CDT SUN JUL 26 2015 SCATTERED THUNDERSTORMS HAVE DEVELOPED LATE THIS AFTERNOON ALONG OLD OUTFLOW BOUNDARY. LATEST HRRR SHOW THUNDERSTORMS CONTINUING ACROSS SOUTHEAST MISSOURI THROUGH THE EVENING HOURS AHEAD OF A WEAK SHORTWAVE TROUGH THAT IS CURRENTLY MOVING SOUTHEASTWARD ACROSS NORTHERN MISSOURI. THE RAP SHOWS THIS SHORTWAVE LIFTING OUT OF THE AREA BY 06Z. BRITT .LONG TERM: (MONDAY THROUGH NEXT SUNDAY) ISSUED AT 328 PM CDT SUN JUL 26 2015 (MONDAY THROUGH WEDNESDAY) MAIN CONCERN WILL BE HEAT ON MONDAY AND TUESDAY WITH HEAT INDICES OF 105 TO 110+ BY TUESDAY AFTERNOON. HAVE EXTENDED THE CURRENT ADVISORY OVER CENTRAL MISSOURI AND HAVE EXPANDED THE ADVISORY TO INCLUDE THE ENTIRE CWA. THE UPPER RIDGE WILL BUILD OVER THE REGION WHICH WILL LIMIT THUNDERSTORMS CHANCES TO SLIGHT CHANCES BOTH DAYS. BECAUSE OF THIS...HIGH TEMPERATURES WILL BE ABLE TO CLIMB INTO THE 90S AS 850MB TEMPERATURES CLIMB INTO THE LOW 20S. FORECAST SOUNDINGS SHOW MIXING UP TO 850MB ON MONDAY AND CLOSE TO 800MB ON TUESDAY. WITH DEWPOINTS WELL IN THE 70S GIVEN THE RECENT RAINFALL...THIS WILL RESULT IN THE HEAT INDICES AROUND 105 ON MONDAY AND NEAR 110 ON TUESDAY. TEMPERATURES WILL BEGIN TO COOL DOWN BY WEDNESDAY AS THE ECMWF/GFS SHOW A COLD FRONT MOVING SOUTHEAST ACROSS THE CWA THROUGH THE DAY. FORCING WILL NOT BE GREAT ALONG THE FRONT, BUT ENOUGH TO INCLUDE A CHANCE OF THUNDERSTORMS. (THURSDAY THROUGH NEXT SUNDAY) STILL EXPECT THIS TO BE A COOLER PERIOD AS THE POLAR FRONT THAT MOVED THROUGH THE AREA ON WEDNESDAY WILL STAY SOUTH OF THE AREA BECAUSE THE UPPER FLOW BECOMING NORTHWESTERLY THROUGH THE WEEKEND. THIS WILL BE BECAUSE OF A BUILDING UPPER HIGH IN THE SOUTHWEST AND A TROUGH IN THE EAST. WHILE THE GFS/ECMWF BOTH AGREE ON THE OVERALL PATTERN CHANGE, THEY DIFFER ON JUST HOW FAST THE UPPER FLOW WILL BE OVER THE AREA AND WHETHER A SECONDARY COLD FRONT WILL MOVE THROUGH THE REGION NEXT SUNDAY. THE GFS SHOWS DEPICTS SOME LIGHT QPF WITH THIS FRONT WHEREAS THE ECMWF IS DRY THROUGH THE EXTENDED PERIOD. FOR NOW WILL GO WITH A DRY FORECAST. WILL ALSO GO WITH SLIGHTLY BELOW NORMAL TEMPERATURES GIVEN 850MB TEMPERATURES IN THE UPPER TEENS CELCIUS. BRITT && .AVIATION: (FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1105 PM CDT SUN JUL 26 2015 ISOLATE TO SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP...NORTHEAST AND TO THE SOUTH OF STL. THIS MOST LIKELY FROM SOME OUTFLOW BOUNDARIES AND SOME ISENTROPIC LIFT WITH THE 850 MB WIND. WIND BEGINS TO BECOME MORE PARALLEL TO THE FLOW BY 06Z AND FINISHED THE PROCESS BY 12Z. WOULD NOT BE SURPRISED TO SEE CONTINUED SPOTTER DEVELOPMENT FOR SEVERAL HOURS YET. THE LATEST HRRR-CR AGREES WITH THIS SCENARIO AND PLACEMENT PRETTY WELL. PRIMARY MODELS DEVELOP SCATTERED ACTIVITY MONDAY AFTERNOON...BUT WITH VERY LOW POPS IN THE FORECAST WILL GO WITH A DRY FORECAST. WITH LIGHT WIND AND RECENT RAIN AT MOST LOCATIONS WILL GO WITH A TEMPO FOR A COUPLE HOURS OF MORING FOG. SPECIFICS FOR KSTL: ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE IN THE AREA. DEPENDING ON LOCATION...MAY CONTINUE THE VCTS A COUPLE MORE HOURS BEYOND 06Z. A LITTLE CONCERNED WITH POSSIBLE FOG IN THE MORNING GIVEN RECENT RAIN. AS USUAL THE MET GUIDANCE HITS CIG/VIS HARD WITH THE MAV VFR. WILL GO AHEAD AND THROW IN A TEMPO FOR A COUPLE OF HOURS MONDAY MORNING. JPK && .LSX WATCHES/WARNINGS/ADVISORIES: MO...HEAT ADVISORY FROM NOON MONDAY TO 9 PM CDT TUESDAY FOR AUDRAIN MO-CRAWFORD MO-FRANKLIN MO-GASCONADE MO-IRON MO-JEFFERSON MO-KNOX MO-LEWIS MO-LINCOLN MO-MADISON MO-MARION MO-MONROE MO-MONTGOMERY MO-PIKE MO-RALLS MO-REYNOLDS MO-SHELBY MO-ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO- STE. GENEVIEVE MO-WARREN MO-WASHINGTON MO. HEAT ADVISORY UNTIL 9 PM CDT TUESDAY FOR BOONE MO-CALLAWAY MO- COLE MO-MONITEAU MO-OSAGE MO. IL...HEAT ADVISORY FROM NOON MONDAY TO 9 PM CDT TUESDAY FOR ADAMS IL- BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL- JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL- MONTGOMERY IL-PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
938 AM MDT MON JUL 27 2015 .UPDATE... MORNING SURFACE ANALYSIS WAS A BIT AMORPHOUS WITH LOCATION OF COLD FRONT WHICH WAS LIKELY CROSSING THE DIVIDE. THERE WAS A PREFRONTAL TROUGH WITH AREAS OF LOW PRESSURE ALONG IT FROM SE MT EXTENDING SW THROUGH WY. RADAR SHOWED BAND OF SHOWERS AND THUNDERSTORMS FROM KTFX/S AREA SSW THROUGH KBTM INTO S ID. OTHER WEAKER THUNDERSTORMS WERE OBSERVED MOVING N THROUGH NE WY. ADJUSTED MORNING POPS TO MATCH CAM MODELS WHICH DID NOT BRING MUCH PRECIPITATION EASTWARD INTO THE AREA BY 18Z. DID ADD LOW POPS TO THE SE CORNER OF THE AREA. CAM MODELS SHOWED TIMING OF CONVECTION TO BE AROUND 20Z INITIATING OFF THE BEARTOOTHS/ABSAROKAS...THEN PROGRESSING E INTO KBIL AREA AROUND 21Z THROUGH 00Z THEN MOVING FURTHER E INTO KMLS AREA/SE MT BEFORE MOVING N OUT OF AREA AROUND 03Z OR SO. NOTED THE NMM AND ARW HAD SLOWER TIMING THAN OTHER MODELS. PUSHED LIKELY POPS A BIT FURTHER E THIS AFTERNOON. VISIBLE SATELLITE AND SURFACE OBSERVATIONS SHOWED A STRATUS LAYER EXPANDING AROUND KBIL DUE TO N FLOW INTO THE PRYORS. RAP HAD THIS LAYER SCATTERING OUT AROUND 16Z-17Z...SO WILL SEE IF THIS PANS OUT. WILL HAVE STRONG LIFT TODAY FROM A COUPLED JET AND Q-VECTOR CONVERGENCE. PRECIPITABLE WATERS WILL BE 1 TO 1.5 INCHES FROM CENTRAL TO E ZONES. SHEAR WILL BE 40 TO 50 KT OVER THESE AREAS AND CAPES WILL BE 500-1000 J/KG WITH HIGHER VALUES ALONG THE DAKOTAS BORDER. CAM MODELS ALSO SHOWED FAIRLY HIGH UPDRAFT HELICITY VALUES OVER CENTRAL AND E. THUS SEVERE WEATHER IS A POSSIBILITY...ESPECIALLY OVER SE MT. STRATUS MAY INHIBIT POTENTIAL SOMEWHAT OVER CENTRAL ZONES. FRONT WILL BECOME BETTER DEFINED THIS AFTERNOON AS IT COMBINES WITH COLD POOLS FROM CONVECTION. WINDS WILL BE ON THE INCREASE BEHIND THE FRONT IN A TIGHT PRESSURE GRADIENT. WILL REVISIT HIGH WIND WATCH FOR TUE IN NEXT PACKAGE. UPPER TROUGH WILL CONTINUE MOVING ACROSS THE AREA THROUGH TUE...ALTHOUGH TUE LOOKED MOSTLY DRY. HIGHEST WINDS WILL BE FOCUSED OVER THE E AND NE ZONES TUE. NO CHANGES NEED TO RED FLAG WARNING IN THE PREFRONTAL ENVIRONMENT. ARTHUR && .SHORT TERM...VALID FOR TDY AND TUE... ACTIVE WEATHER THROUGH THE SHORT TERM WITH THUNDERSTORMS...A STRONG COLD FRONT PASSAGE AND FIRE WEATHER CONCERNS TODAY WITH WIND AND FIRE WEATHER CONCERNS FOR TUESDAY. WATER VAPOR SHOWING A A DEEP TROUGH AND UPPER LOW MOVING ONTO THE PACIFIC NORTHWEST COAST WITH TWO VORT MAXES...ONE CENTERED OVER OREGON AND THE SECOND MOVING INTO NEVADA. THIS WILL PROVIDE A DEEP SOUTHWEST FLOW ALOFT ACROSS OUR FORECAST AREA TODAY. AS THIS TROUGH MOVES EAST...IT WILL SWEEP A STRONG COLD FRONT ACROSS THE AREA. TIMING LOOKS TO BE EARLY THIS MORNING FOR OUR FAR WESTERN AREAS...LATE MORNING/EARLY AFTERNOON FOR THE CENTRAL AREAS AND LATE AFTERNOON/EARLY EVENING FOR THE FAR EAST. AS A RESULT...A LARGE TEMPERATURE DIFFERENCE FOR HIGHS WILL EXIST TODAY RANGING FROM 60S WEST TO THE LOWER 90S EAST. SHOWERS AND THUNDERSTORMS WILL DEVELOP AHEAD OF AND ALONG THE FRONT WITH NUMEROUS SHOWERS INCREASING IN COVERAGE BEHIND THE FRONT. THE STORM PREDICTION CENTER HAS ADDED A SLIGHT RISK FOR SEVERE THUNDERSTORMS FROM YELLOWSTONE COUNTY EASTWARD AND AN ENHANCED RISK ACROSS THE EXTREME EASTERN AREAS OF THE STATE. BEST DYNAMICS WILL BE FROM CUSTER AND POWDER RIVER COUNTIES EASTWARD BUT ESPECIALLY NEAR THE DAKOTA BORDER. SEVERE THUNDERSTORMS WILL BE POSSIBLE FOR THESE AREAS AND HAVE ADDED THIS MENTION TO THE GRIDS. IN ADDITION...VERY WARM TEMPERATURES...LOW HUMIDITIES...INCREASING THUNDERSTORM RISK AND STRONG WINDS WITH THE FRONTAL PASSAGE WILL RESULT IN RED FLAG CONDITIONS ACROSS OUR EASTERN AREAS WHERE A REG FLAG WARNING IS IN PLACE. PRECIPITATION CHANCES WILL INCREASE FROM WEST TO EAST THROUGH THE DAY INTO THIS EVENING WITH LIKELY POPS ALONG AND NORTH OF A MILES CITY-BILLINGS- LIVINGSTON LINE. THE BULK OF THE PRECIP WILL MOVE INTO NORTHEAST MONTANA AND NORTH DAKOTA LATE THIS EVENING INTO TUESDAY. HOWEVER...THE DEEP SURFACE LOW WILL PROVIDE FOR WRAP AROUND SHOWERS ACROSS MOST OF OUR AREA TUESDAY WITH THE BEST CHANCES EAST AND NORTH OF BILLINGS. LASTLY...850MB WINDS TUESDAY ACROSS THE EAST WILL BE AROUND 45-50KTS AND LATEST GUIDANCE HAS 35-40KT WINDS FOR MILES CITY AND BAKER. WILL ISSUE A HIGH WIND WATCH FOR TUESDAY MORNING AND AFTERNOON FOR NORTHERN ROSEBUD...CUSTER...FALLON AND CARTER COUNTIES AS THESE AREAS LOOK TO HAVE THE TIGHTEST PRESSURE GRADIENTS FROM THE SURFACE LOW WHICH IS PROGGED TO BE OVER NORTHERN NORTH DAKOTA DURING THAT TIME PERIOD. HOOLEY .LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN... MAINLY DRY EXTENDED PERIOD WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. MODELS ARE MAINTAINING GOOD AGREEMENT SHOWING ZONAL FLOW OVER THE REGION WITH A DRY AIRMASS. WEAK INTRUSION OF MONSOONAL FLOW INTRODUCES SOME CONVECTION OVER THE MOUNTAINS FRIDAY NIGHT. MODELS SHOWED A BACKDOOR COLD FRONT APPROACHING BUT WASHING OUT ON SATURDAY NIGHT. CURRENT FORECAST IN GOOD SHAPE. BORSUM && .AVIATION... AS OF 15Z A COLD FRONT IS ENTERING WESTERN ZONES NEAR LVM AND NORTHERLY WINDS ARE GENERATING AN UPSLOPE 1400FT STRATUS DECK OVER BIL. THIS STRATUS DECK THAT IS GENERATING MVFR CIGS SHOULD ERODE BY 18-20Z AS THE FRONT GETS CLOSER TO BIL. THROUGH THE AFTERNOON A LINE OF SHOWERS AND STORMS WILL PROGRESS EAST AND GENERATE MVFR/IFR CONDITIONS WITH MOUNTAIN OBSCURATIONS AROUND LVM FROM 18-20Z...BIL 21-23Z...SHR 22-01Z...AND MLS 23-02Z. AFTER THE INITIAL LINE OF STORMS VCSH...WITH POSSIBLE MVFR CONDITIONS...AND INCREASING WESTERLY WINDS AROUND 25 TO 35 KNOTS WILL AFFECT ALL TERMINALS FOR THE REMAINDER OF THE TAF PERIOD. DOBBS && .PRELIMINARY POINT TEMP/POPS... TDY TUE WED THU FRI SAT SUN ------------------------------------------------------- BIL 077 051/075 052/085 057/092 060/094 061/090 061/090 6/T 42/W 11/U 00/U 01/U 11/U 11/B LVM 067 048/074 045/083 051/089 053/092 054/089 055/088 6/T 43/T 11/U 00/U 01/U 11/U 22/T HDN 083 051/076 051/087 055/094 058/096 059/092 059/091 6/T 62/W 11/U 00/U 01/U 11/U 11/B MLS 090 055/072 052/086 058/093 061/095 061/092 061/089 3/T 83/T 21/U 00/U 01/U 11/U 11/B 4BQ 094 053/074 051/086 056/093 060/095 061/093 060/089 3/T 42/W 11/U 00/U 01/U 11/U 11/B BHK 095 056/071 050/084 055/090 057/092 058/090 058/086 4/T 73/T 21/U 00/U 01/U 11/U 11/B SHR 087 047/074 045/083 053/091 055/093 056/091 056/088 3/T 32/W 00/U 00/U 00/U 01/U 12/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR ZONES 30>33-36>38-57-58. HIGH WIND WATCH IN EFFECT FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR ZONES 31>33-37. WY...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR ZONES 98-99. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
331 PM CDT MON JUL 27 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 330 PM CDT MON JUL 27 2015 PRIMARY FORECAST CONCERN IN THE SHORT TERM DEALS WITH CONVECTIVE CHANCES LATE THIS AFTERNOON INTO THE OVERNIGHT. A SECONDARY CONCERN IS THE PASSAGE OF A COLD FRONT...WHICH WILL PROVIDE FOR COOLER...AND DRIER CONDITIONS. FORECAST CONFIDENCE WITH THE CONVECTIVE CHANCES ARE NOT AS HIGH AS ONE WOULD HOPE...ESPECIALLY GIVEN THE RECENT PERFORMANCE OF THE SHORT TERM MODELS. THAT BEING SAID...THE 12Z NAM WITH SUPPORT FROM THE LATEST RAP AND SEVERAL RUNS OF THE HRRR INDICATE TWO FAVORED AREAS FOR DEVELOPMENT LATE THIS AFTERNOON AND EARLY EVENING. THE FIRST IS ALONG A DRYLINE PUSH ACROSS NORTHEAST COLORADO. CURIOUS HOWEVER AS TO WHY THE MODEL IS SO AMBITIOUS WITH THE NORTHEASTWARD EXTEND OF INITIAL CONVECTION INTO SOUTHWEST NEBRASKA...BUT ON FURTHER INVESTIGATION...THE MODEL SEEMS TO BE KEYING ON A SOUTHWEST TO NORTHEAST LINE OF H7 FRONTOGENESIS EXTENDING INTO THE AREA. REGARDLESS THE LATEST MESOSCALE ANALYSIS SHOWS AN ENHANCED AREA OF DEEP LAYER MOISTURE CONVERGENCE ACROSS NORTHWEST KANSAS YIELDING SUPPORT TO THE CONVECTIVE INITIATION IN THE VICINITY OF THE TRI- STATE REGION. INSTABILITY IN THIS AREA IS SIGNIFICANT...BUT DEEP LAYER SHEAR IS LACKING. STORMS MAY HAVE TROUBLE INITIALLY...BUT AS A LLJ STRENGTHENS...CELLS SHOULD GROW UPSCALE INTO A EAST NORTHEAST PROPAGATING MCS. AM CONCERNED WITH THE HEAVY RAIN THREAT AT THIS POINT AS BUFR SOUNDINGS SHOW NEAR RECORD PWATS AT KLBF BEFORE STORM INITIATION...AND STORM MOTIONS OF 15KTS OR SO. IF THE CONVECTIVE COMPLEX MATERIALIZES LATE EVENING TO OVERNIGHT...VERY HEAVY RAINFALL IS POSSIBLE ACROSS OUR SOUTH AS WARM CLOUD DEPTHS INCREASE OVER 11K FEET. THE SECOND AREA OF CONVECTIVE DEVELOPMENT APPEARS TO BE JUST UNDERWAY ACROSS FAR EASTERN WYOMING AND WESTERN NEBRASKA AS THE DRY LINE/THETA GRADIENT MIXES EAST. HOWEVER THE MODELS SEEM TO HAVE STRUGGLED WITH THE AMOUNT OF MIXING TODAY...AND GIVEN NO OTHER DISCERNABLE FEATURES OF LOW-LEVEL CONVERGENCE AT THIS TIME...CONVECTIVE CHANCES ACROSS THE SANDHILLS LATE AFTERNOON ARE IN QUESTION. THE HRRR CONTINUES TO BE FIXED ON A SOLUTION HOWEVER OF CONVECTIVE CLUSTER/S/ SPREADING EAST WITH TIME ACROSS MUCH OF THE SANDHILLS AND NORTHERN NEBRASKA. THE HRRR PICKED UP ON THIS SOLUTION EARLY...AND DID WELL WITH LAST NIGHTS CONVECTION...SO WILL HEAVILY CONSIDER THE GUIDANCE FOR THIS EVENING. EFFECTIVE BULK SHEAR IS LACKING AS OF NOW ACROSS THE SANDHILLS...BUT SLOWLY INCREASES OVER THE NEXT 6 HOURS...WITH SIGNIFICANT CAPE IN PLACE. LARGE HAIL AND GUSTY WIND WILL ALSO BE POSSIBLE WITH THESE CONVECTIVE STORMS. COLD FRONT ARRIVES DRY ASSUMING THE CONVECTION PLAYS OUT AS INDICATED ABOVE...STABLE AND COOLER CONDITIONS WILL FOLLOW FOR TUESDAY. WILL NEED TO MONITOR RH VALUES DURING PEAK HEATING ON TUESDAY ACROSS ZONES 204 AND 210...AS READINGS ARE SHOWN TO FALL BELOW 20 PERCENT. FUELS HOWEVER ARE NOT SUSCEPTIBLE TO LARGE FIRE GROWTH. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 330 PM CDT MON JUL 27 2015 TUESDAY NIGHT...AS SURFACE HIGH PRESSURE BUILDS INTO WESTERN NEBRASKA...CLEAR SKIES...LOWER SURFACE DEWPOINTS IN THE LOW TO MID 40S WILL RESULT IN A RELATIVELY COOL NIGHT. LOWS FROM THE UPPER 40S ERN PNHDL WITH LOWER TO MID 50S MUCH OF WESTERN NEBRASKA. DRY CONDITIONS EXPECTED WEDNESDAY AND WEDNESDAY NIGHT WITH SURFACE HIGH PRESSURE AND A DRIER AIRMASS IN PLACE. WITH DEWPOINTS WEDNESDAY ONLY IN THE MID TO UPPER 40S AND HIGHS AROUND 85...THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITY FALLING TO ABOUT 25 PERCENT. MOISTURE WILL RETURN TO THE CENTRAL HIGH PLAINS INCLUDING WRN NEBR ON THURSDAY. BY AFTERNOON...ISOLATED TSTMS ARE POSSIBLE MAINLY WEST OF VALENTINE THROUGH NORTH PLATTE THEN LINGER INTO THURSDAY NIGHT ACROSS THE SRN HALF OF THE FA. ISOLATED TO SCATTERED THUNDERSTORMS POSSIBLE FRIDAY THROUGH MONDAY WITH NWRLY FLOW PERSISTING ALOFT. LOW LEVEL MOISTURE IS FORECAST TO RESIDE ACROSS THE AREA ONCE AGAIN. TEMPERATURES WILL RANGE FROM NEAR 90 THURSDAY THEN UPPER 80S TO LOWER 90S FRIDAY THROUGH MONDAY. MEDIUM RANGE MODELS AGREE ON A HUDSON BAY LOW PERSISTING WITH AN UPPER RIDGE REMAINING ACROSS THE DESERT SOUTHWEST. THIS WOULD BRING THE POTENTIAL FOR BELOW NORMAL TEMPERATURES TO THE GREAT LAKES REGION...WHILE NORMAL TEMPERATURES WOULD RESIDE ACROSS THE CENTRAL PLAINS INCLUDING WESTERN NEBRASKA. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1252 PM CDT MON JUL 27 2015 CONVECTION CHANCES HIGHLIGHT THE AVIATION FORECAST...WE ANTICIPATED STORMS...SOME OF WHICH MAY BE ON THE STRONG TO SEVERE SIDE...FORMING ONCE AGAIN THIS AFTERNOON AND EVENING ACROSS WEST CENTRAL NEBRASKA. THE MOST LIKELY SCENARIO SUGGESTS THAT STORM INITIATION WILL OCCUR IN TWO FAVORED AREAS...OVER THE EASTERN PANHANDLE AND OVER NORTHEAST COLORADO. THEN STORMS ARE SHOWN TO MOVE EAST NORTHEAST THROUGH THE EVENING HOURS...POSSIBLY IMPACTING BOTH KLBF AND KVTN. THIS FORECAST FOLLOWS THE NEAR TERM GUIDANCE OF THE LATEST HRRR MODEL RUN. OTHERWISE GUSTY ERRATIC WINDS AND IFR /OR LOWER/ VISIBILITY RESTRICTIONS WOULD BE POSSIBLE UNDER ANY STORM THAT DEVELOPS. A FRONT WILL DROP SOUTHEAST OVERNIGHT PROVIDING FOR A WIND SHIFT TO THE NORTHWEST AND CONTINUED GUSTY CONDITIONS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...JACOBS LONG TERM...ROBERG AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1252 PM CDT MON JUL 27 2015 .SYNOPSIS... ISSUED AT 354 AM CDT MON JUL 27 2015 HAND ANALYSIS OF THE 07Z MSL DATA SHOWED A FRONT FROM A LOW ALONG THE WYOMING-MONTANA LINE STRETCHED ACROSS NORTHERN NEBRASKA. THERE WAS ALSO A LOW IN EASTERN NEBRASKA WITH A COUPLE OF BOUNDARIES. SURFACE DEWPOINTS INDICATED THAT THE DRY LINE WAS ACROSS EASTERN WYOMING THROUGH EASTERN COLORADO INTO THE OKLAHOMA PANHANDLE. THE SURFACE MSAS INDICATED THAT THE THETA-E RIDGE WAS JUST EAST OF THE DRY LINE. THE RADAR WIND PROFILES SHOWED A NOSE OF THE LOW LEVEL JET BETWEEN THEDFORD AND RAPID CITY. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 354 AM CDT MON JUL 27 2015 LOW LEVEL FLOW WILL CONTINUE FEEDING MOISTURE INTO WESTERN NEBRASKA...THUS STRENGTHENING THE THETA-E RIDGE ACROSS THE AREA ALONG THE DRY LINE. CONVERGENCE IN THE THETA-E GRADIENT WILL GENERATE THUNDERSTORMS AGAIN LATE THIS MORNING OR EARLY AFTERNOON. THE NAM12 APPEARS TO BE AN OUTLIER WITH THE TIMING. HOWEVER...WITH THE LOW LEVEL JET EXTENDING INTO THE NEBRASKA SANDHILLS...IT IS POSSIBLE THAT CONVECTION COULD DEVELOP THIS MORNING. THE RAP13 AND GFS40 APPEAR TO FAVOR A LATER ONSET. LOOKING AT THE 0-2KM THETA-E PROJECTIONS FROM THE THREE...IT APPEARS THAT THE LATER TIMING MAY BE APPROPRIATE. STILL...THE NAM12 SOLUTION CASTS ENOUGH DOUBT THAT I HAVE ONLY MODERATE CONFIDENCE IN THE PRECIPITATION FORECAST TODAY. IN ANY CASE...IT APPEARS THAT THE SCENARIO WILL PLAY OUT MUCH LIKE IT DID YESTERDAY WITH THE CONVECTIVE INITIATION OVER WESTERN NEBRASKA. CURRENT IDEA IS TO USE A 2/3 BLEND OF THE CURRENT FORECAST WITH THE OTHER MODELS AND GIVE MORE WEIGHT TO THE RAP13 AND THE CANADIAN REGIONAL. ANYWAY...THE SHORT RANGE PROJECTIONS INDICATE SUFFICIENT CONVECTIVE POTENTIAL ENERGY AND 0-6M BULK SHEAR FOR LARGE HAIL OVER THE NORTH AND SLIGHTLY MORE MARGINAL CENTRAL AND SOUTHWEST NEBRASKA. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 354 AM CDT MON JUL 27 2015 COLD FRONT SHOULD BE EAST OR NEARLY EAST OF THE AREA BY TUESDAY MORNING. MODELS CONTINUE TO INCREASE SPEED OF THE COLD FRONT AND NOW LOOKS LIKE BY TUESDAY MORNING THE CONVECTION ASSOCIATED WITH THE FRONT WILL ALSO BE EAST OF THE CWA. THIS WILL RESULT IN A NICE DRY JULY DAY WITH TEMPS TOPPING OUT IN THE 80S. DECIDED WITH MOSTLY SUNNY SKIES...TO GO ON THE HIGHER SIDE OF MOS GUIDANCE. MODELS ALSO IN AGREEMENT WITH VERY DRY /FOR JULY/ AIR TO WORK IN BEHIND THE FRONT. DEW PTS SHOULD EASILY DROP INTO THE 40S FOR MOST IF NOT ALL THE CWA. SOME MODELS EVEN BRING SOME UPPER 30S INTO THE PANHANDLE. WITH THE DRY AIR...MOS GUIDANCE IS TANKING TEMPS. SEE NO REASON WITH THE LOW DEW PTS AND MOSTLY CLEAR SKIES IN PLACE...WHY THIS WILL NOT BE ABLE TO BE REACHED. RECORD LOWS FOR WED /29TH/ ARE FAIRLY WARM WITH MOST IN THE UPPER 40S. WILL HAVE TO MONITOR THE BL MOISTURE AND POSSIBLY SOME PASSING HIGH CLOUDS FROM SOME LIMITED PACIFIC MOISTURE TO SEE HOW LOW WE COULD FALL TO. FOR EXAMPLE THE RECORD LOW FOR NORTH PLATTE IS ONLY 49 DEGREES...WHICH IS POSSIBLE. BOTH THE MET AND MAV GUIDANCE DROPS THE LOW TO 50. WEDNESDAY WILL AGAIN BE COOL WITH LOWER TO MID 80S FOR HIGHS AND DRY. THE UPPER LEVEL TROUGH WILL PUSH TO THE EAST AS MORE ZONAL FLOW DEVELOPS. SFC FRONT STALLED OVER KS SO EXPECTING ANOTHER DRY DAY. THIS CHANGES AS WE GO TO THE END OF THE WEEK AND THE WEEKEND. THE ZONAL FLOW BECOMES MORE NORTHWESTERLY WITH SEVERAL CLIPPERS /SHORT WAVES/ TO MOVE QUICKLY ACROSS THE NORTHERN/HIGH PLAINS. ALSO GOING TO SEE SW/S WINDS DEVELOP AND HELP TO RETURN THE MOISTURE. TIMING EACH PASSING WAVE IS DIFFICULT THIS FAR OUT...BUT EACH WAVE WILL LIKELY RESULT IN ISOLD TO SCT STORMS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1252 PM CDT MON JUL 27 2015 CONVECTION CHANCES HIGHLIGHT THE AVIATION FORECAST...WE ANTICIPATED STORMS...SOME OF WHICH MAY BE ON THE STRONG TO SEVERE SIDE...FORMING ONCE AGAIN THIS AFTERNOON AND EVENING ACROSS WEST CENTRAL NEBRASKA. THE MOST LIKELY SCENARIO SUGGESTS THAT STORM INITIATION WILL OCCUR IN TWO FAVORED AREAS...OVER THE EASTERN PANHANDLE AND OVER NORTHEAST COLORADO. THEN STORMS ARE SHOWN TO MOVE EAST NORTHEAST THROUGH THE EVENING HOURS...POSSIBLY IMPACTING BOTH KLBF AND KVTN. THIS FORECAST FOLLOWS THE NEAR TERM GUIDANCE OF THE LATEST HRRR MODEL RUN. OTHERWISE GUSTY ERRATIC WINDS AND IFR /OR LOWER/ VISIBILITY RESTRICTIONS WOULD BE POSSIBLE UNDER ANY STORM THAT DEVELOPS. A FRONT WILL DROP SOUTHEAST OVERNIGHT PROVIDING FOR A WIND SHIFT TO THE NORTHWEST AND CONTINUED GUSTY CONDITIONS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SPRINGER SHORT TERM...SPRINGER LONG TERM...MASEK AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
308 PM EDT MON JUL 27 2015 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE AREA AND BRING HOT AND HUMID WEATHER THROUGH WEDNESDAY. ON THURSDAY...A COLD FRONT WILL PUSH THROUGH BRING SHOWERS AND THUNDERSTORMS...FOLLOWED BY SOMEWHAT COOLER AIR FOR FRIDAY. . && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... WEAK CONV FIRING ATTM OVER OVER THE HIER TERRAIN OF THE CATSKILLS. SHRT TERM MODELS HAVE FCST THE INITIATION WELL AND CONT MAINLY LGT CONV INTO THE EVE. XCPTN IS THE HRRR THAT ALSO FIRES SOME CELLS ARND THE FINGER LAKES REGION. HAVE DECIDED TO IGNORE THIS FOR NOW AS VSBL/RADAR SHOWS NOTHING. PWATS AND INSTABILITY MUCH LESS TODAY THAN YSTRDY AND WE LACK ANY REAL TRIGGER FOR CONV...SO NOT XPCTG A REPEAT OF YSTRDY/S SVR/NEAR SVR EVENT. MUCH DRIER AIR IN PLACE TNGT...BOTH SFC AND ALOFT...AND WITHOUT AFNT CONV...XPCT FOG TO BE MUCH LESS WIDESPREAD THAN LAST NGT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... SFC HIPRES AND UPR RDG BLDS TUE INTO WED. COMBINATION OF DRIER AIR AND MID LVL WRMG WILL SUPPRESS ANY CONV DVLPMT DESPITE THE HTG AS TEMPS RCH NEAR OF SLGTLY ABV 90F. WARMEST AIR WILL BE OVER THE DEEPER VLYS OF THE CNTRL SRN TIER AND IN NEPA. COLD FNT CRASHES INTO THE RDG ON THU BUT WHILE RDG FLATTENS...PLENTY OF MID LVL WRM AIR APRNTLY STILL ARND LIMITING INSTABILITY. UPR SUPPORT FOR THE FNT REMAINS WELL BACK OVER THE LAKES AND MODEL FCST OF CONV WEAKENS THRU THE DAY THU. IN ANY EVENT...A LEAST A CHANCE OF TSTM SEEMS RSNBL FOR THU. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... 300 PM UPDATE... A QUIET LONG TERM PORTION OF THE FORECAST. SUNSHINE IS EXPECTED FRIDAY AND SATURDAY WITH SEASONABLE TEMPS (HIGHS IN THE 80S LOWS IN THE 60S). THE NEXT POTENTIAL FOR RAIN WILL BE SUNDAY NIGHT INTO MONDAY WITH A COLD FRONT. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... LINGERING CLOUDS AT KAVP MAY PRODUCE ANOTHER HOUR AT MOST OF MVFR CIGS THROUGH 19Z, OTHERWISE A RETURN TO VFR IS EXPECTED. VFR ALL TERMINALS THROUGH EARLY EVENING. DENSE VALLEY FOG EXPECTED AGAIN AT KELM, JUST NOT QUITE AS EARLY AS LAST NIGHT. BELOW AIRPORT MINS POSSIBLE AFTER 08Z. AT KBGM AND KAVP LIGHT FOG POSSIBLE AFTER 08Z. VFR TUESDAY. .OUTLOOK... WEDNESDAY...VFR. POSSIBLE IFR/MVFR FOG AT ELM IN THE AM. THURSDAY...RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS. FRIDAY/SATURDAY...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM...HEDEN AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
234 PM EDT MON JUL 27 2015 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE AREA AND BRING HOT AND HUMID WEATHER THROUGH WEDNESDAY. ON THURSDAY...A COLD FRONT WILL PUSH THROUGH BRING SHOWERS AND THUNDERSTORMS...FOLLOWED BY SOMEWHAT COOLER AIR FOR FRIDAY. . && .NEAR TERM /THROUGH TONIGHT/... WEAK CONV FIRING ATTM OVER OVER THE HIER TERRAIN OF THE CATSKILLS. SHRT TERM MODELS HAVE FCST THE INITIATION WELL AND CONT MAINLY LGT CONV INTO THE EVE. XCPTN IS THE HRRR THAT ALSO FIRES SOME CELLS ARND THE FINGER LAKES REGION. HAVE DECIDED TO IGNORE THIS FOR NOW AS VSBL/RADAR SHOWS NOTHING. PWATS AND INSTABILITY MUCH LESS TODAY THAN YSTRDY AND WE LACK ANY REAL TRIGGER FOR CONV...SO NOT XPCTG A REPEAT OF YSTRDY/S SVR/NEAR SVR EVENT. MUCH DRIER AIR IN PLACE TNGT...BOTH SFC AND ALOFT...AND WITHOUT AFNT CONV...XPCT FOG TO BE MUCH LESS WIDESPREAD THAN LAST NGT. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... SFC HIPRES AND UPR RDG BLDS TUE INTO WED. COMBINATION OF DRIER AIR AND MID LVL WRMG WILL SUPPRESS ANY CONV DVLPMT DESPITE THE HTG AS TEMPS RCH NEAR OF SLGTLY ABV 90F. WARMEST AIR WILL BE OVER THE DEEPER VLYS OF THE CNTRL SRN TIER AND IN NEPA. COLD FNT CRASHES INTO THE RDG ON THU BUT WHILE RDG FLATTENS...PLENTY OF MID LVL WRM AIR APRNTLY STILL ARND LIMITING INSTABILITY. UPR SUPPORT FOR THE FNT REMAINS WELL BACK OVER THE LAKES AND MODEL FCST OF CONV WEAKENS THRU THE DAY THU. IN ANY EVENT...A LEAST A CHANCE OF TSTM SEEMS RSNBL FOR THU. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... 230 AM UPDATE... LITTLE CHANGE TO THE GRIDS. UPDATED WITH THE LATEST WPC GUIDANCE. RAIN SHOWERS AND THUNDERSTORMS THURSDAY THEN DRY FRIDAY AND PROBABLY SATURDAY. SHOWERS AND THUNDERSTORMS AGAIN SUNDAY AND MONDAY. BOTH PRECIP EVENTS WITH COLD FRONTS. 245 PM UPDATE... AFTER EXPERIENCING HOT WEATHER FOR A FEW DAYS UPPER LEVEL HEIGHTS GRADUALLY FALL FROM MID WEEK INTO THE WEEKEND ALLOWING FOR A RETURN TO NEAR NORMAL WEATHER FOR MID SUMMER. BEST SHOT FOR PRECIPITATION WILL BE THURSDAY WITH GOOD MODEL AGREEMENT BETWEEN THE GFS AND EURO ON A COLD FRONTAL PASSAGE. 850 TEMPS FALL INTO THE MID TEENS BY FRIDAY WITH HIGHS NEAR 80 FRIDAY AFTERNOON. WEAK BOUNDARY MAY BRING US ANOTHER SHOT AT PRECIP SATURDAY BUT THIS FAR OUT, KEPT IT AT OR BELOW 30% GIVEN SOME UNCERTAINTY. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... LINGERING CLOUDS AT KAVP MAY PRODUCE ANOTHER HOUR AT MOST OF MVFR CIGS THROUGH 19Z, OTHERWISE A RETURN TO VFR IS EXPECTED. VFR ALL TERMINALS THROUGH EARLY EVENING. DENSE VALLEY FOG EXPECTED AGAIN AT KELM, JUST NOT QUITE AS EARLY AS LAST NIGHT. BELOW AIRPORT MINS POSSIBLE AFTER 08Z. AT KBGM AND KAVP LIGHT FOG POSSIBLE AFTER 08Z. VFR TUESDAY. .OUTLOOK... WEDNESDAY...VFR. POSSIBLE IFR/MVFR FOG AT ELM IN THE AM. THURSDAY...RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS. FRIDAY/SATURDAY...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...DGM SHORT TERM...DGM LONG TERM...HEDEN/TAC AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 PM EDT MON JUL 27 2015 .SYNOPSIS...A SERIES OF PERTURBATIONS ALOFT INTERACTING WITH A MOIST AND UNSTABLE AIR MASS WILL TRIGGER SCATTERED THUNDERSTORMS...MAINLY DURING THE AFTERNOON AND EVENING HOURS...THROUGH THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 325 PM MONDAY... A WEAK SURFACE TROUGH IMMEDIATELY TO THE NW OF CENTRAL NC WILL BE A FOCUS FOR THE DEVELOPMENT OF SCATTERED CONVECTION THROUGH EARLY EVENING. ATMOSPHERE ACROSS CENTRAL NC IS SLIGHTLY UNSTABLE AND EFFECTIVE BULK SHEAR REMAINS MARGINAL. MEAN STEERING FLOW WOULD USHER CONVECTION IN THE HIGHER TERRAIN OF WESTERN NC-SW VA INTO THE NW PIEDMONT LATE THIS AFTERNOON-EARLY EVENING. MAIN QUESTION IS HOW FAR EAST-SOUTH DOES THE SCATTERED CONVECTION GO BEFORE DIMINISHING. THE HRRR AND RAP BOTH SUGGEST THAT CONVECTION MAKES A RUN FOR THE TRIANGLE AREA BUT DIMINISHES IN COVERAGE AND INTENSITY BEFORE CROSSING THE REGION. CONSIDERING THAT A MINOR MOISTURE/INSTABILITY AXIS EXTENDS NW-SE ACROSS THE TRIANGLE...APPEARS THAT ANY CONVECTION THAT EXITS THE NW PIEDMONT SHOULD CONTINUE PROGRESS E-SE INTO THE TRIANGLE AREA. THUS...PLAN TO MAINTAIN A CHANCE POP OVER THIS REGION THROUGH MOST OF THE EVENING. AFTER MIDNIGHT...A MOIST LOW LEVEL AIR MASS SHOULD GENERATE AREAS OF FOG AND/OR LOW CLOUDS BY EARLY TUESDAY. NOT EXPECTING ANY DENSE FOG AS VISIBILITIES SHOULD BE NO WORSE THAN A MILE OR TWO. LOW CEILINGS MAY COVER MORE OF THE REGION THAN WHAT OCCURRED EARLY MONDAY MORNING. IN ADDITION...A SERIES OF WEAK PERTURBATIONS ALOFT MAY TRIGGER A SHOWER OR TWO ANYWHERE ACROSS THE CWA. MIN TEMPS 69-73. && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... AS OF 325 PM MONDAY... A WEAK SFC TROUGH WILL REMAIN STALLED IN VICINITY OF THE WESTERN PIEDMONT. ALOFT...AN UPPER RIDGE CENTERED OVER THE SOUTHERN PLAINS BRIEFLY AMPLIFIES INTO THE WESTERN LAKES...VEERING FLOW ALOFT OVER CENTRAL NC TO A NWLY DIRECTION. WEAK PERTURBATIONS EMBEDDED IN THIS FLOW ALOFT INTERACTING WITH THE STALLED SFC TROUGH AND AVAILABLE MOISTURE/INSTABILITY SHOULD TRIGGER SCATTERED CONVECTION...MAINLY IN THE AFTERNOON AND EVENING HOURS. PROBABILITY OF SCATTERED CONVECTION APPEARS BEST IN VICINITY OF THE STALLED SFC TROUGH IN THE WESTERN PIEDMONT...AND IN VICINITY WHERE THE PERTURBATIONS ALOFT TRACK THROUGH THE REGION. THUS...POPS WILL VARY FROM SOLID CHANCE(SCATTERED) ACROSS THE NORTHERN PIEDMONT-NORTHERN COASTAL PLAIN TO SLIGHT CHANCE(ISOLATED)OVER THE FAR SOUTHERN COUNTIES. BULK OF CONVECTION WILL DIMINISH WITH LOSS OF HEATING TUESDAY EVENING THOUGH A FEW SHOWERS MAY OCCUR WELL INTO THE NIGHT DUE TO PERTURBATIONS IN THE NW FLOW ALOFT INTERACTING WITH THE MOISTURE RICH AIR MASS OVER OUR REGION. WHILE A STRONG OR SEVERE STORM CANNOT BE RULED OUT TUESDAY AFTERNOON...BULK OF CONVECTIVE PARAMETERS POINT TOWARD MOST OF THE STORMS REMAINING BELOW SEVERE CRITERIA. MAX TEMPS TUESDAY HIGHLY DEPENDENT ON EXTENT OF EARLY MORNING CLOUDS AND TIMING OF AFTERNOON CONVECTION. FAVORING PARTIAL SUN TO OCCUR FOR MOST OF THE LATE MORNING-EARLY AFTERNOON...BOOSTING TEMPS WELL INTO THE 80S-AROUND 90. IF LOW CLOUDS LINGER PAST NOON OR CONVECTION DEVELOP BY NOON-2 PM...THAN MAX TEMPS MAY END UP BEING 3-5 DEGREES COOLER THAN FORECAST. MIN TEMPS TUESDAY NIGHT 70-74. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 245 PM MONDAY... MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A MID LEVEL RIDGE CENTERED ACROSS THE CENTRAL/SOUTHERN PLAINS AND LOWER MS RIVER VALLEY TO START THE PERIOD (WEDNESDAY)... THEN RETROGRADING IT WESTWARD ACROSS THE WESTERN U.S. BY LATE WEEK. THE MID LEVEL RIDGE IS FORECAST TO BUILD NORTH/NORTHWESTWARD AS IT RETROGRADES... HELPING TO AMPLIFY THE MID/UPPER LEVEL FLOW PATTERN ACROSS THE CONUS. THIS SHOULD YIELD BROAD MID LEVEL TROUGHING FOR CENTRAL NC LATE WEEK INTO EARLY NEXT WEEK... WITH A SURFACE COLD FRONT PUSHING INTO THE AREA FROM THE NORTH AND WEST LATE THURSDAY INTO FRIDAY. HOWEVER... THE STRONGER FLOW ALOFT WILL REMAIN TO THE NORTH OF CENTRAL NC... YIELDING GENERALLY WEAK DEEP LAYER SHEAR. QUESTIONS STILL REMAIN IF THE FRONT WILL PUSH THROUGH THE AREA OR SETTLE ACROSS SOUTHEASTERN PORTIONS OF CENTRAL NC... AND RESULTANT HOW LONG PRECIP CHANCES WILL CONTINUE ACROSS CENTRAL NC. FOR NOW WILL TO TREND THE FORECAST TOWARDS AN UNSETTLED PATTERN FOR LATE THURSDAY THROUGH SUNDAY... WITH THE POTENTIAL FOR HIGH MOISTURE CONTENT AIR TO ADVECT INTO THE FROM THE NORTHEASTERN GULF OF MEXICO ALONG WITH POTENTIALLY A FEW WEAK DISTURBANCES LIFTING NORTH-NORTHEASTWARD AND ACROSS SOUTH/EASTERN PORTIONS OF THE FA. HOWEVER... DEPENDING ON HOW FAR SOUTH AND EAST THE BOUNDARY MAKES IT WILL DETERMINE HOW MUCH OF THE AREA SEE A GOOD CHANCE FOR SHOWERS AND STORMS OVER THE WEEKEND... ALONG WITH THE POTENTIAL FOR HEAVY RAIN. THUS... WILL LIMIT POPS TO CHANCE FOR NOW BUT RAISE THEM A BIT... WITH THE HIGHEST POPS SOUTH/SOUTHEAST THIS WEEKEND. HIGH TEMPS AHEAD OF THE FRONT ON WEDNESDAY AND THURSDAY ARE EXPECTED TO BE NEAR NORMAL... GENERALLY AROUND 90 TO THE LOWER TO MID 90S. HIGH BEHIND THE FRONT WILL GENERALLY BE IN THE MID TO UPPER 80S... WITH A FEW LOCATIONS TOUCHING THE LOWER 90S... DEPENDING ON THE PRECIP. LOWS AHEAD OF THE FRONT AREA EXPECTED TO BE IN THE LOWER TO MID 70S. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 125 PM MONDAY... A WEAK SURFACE FRONT DRIFTING SOUTHWARD INTO NC FROM VA INTERACTING WITH AN INCREASINGLY MOIST AND SLIGHTLY UNSTABLE AIR MASS WILL GENERATE VARYING DEGREES OF CLOUDINESS AND ISOLATED-SCATTERED CONVECTION THIS AFTERNOON INTO THE EVENING HOURS. WHILE VFR CONDITIONS SHOULD DOMINATE AT THE TAF SITES THIS AFTERNOON-THIS EVENING...THERE WILL BE A CHANCE FOR MVFR CEILING/VISIBILITY DUE TO CONVECTION IN THE TRIAD VICINITY...ESPECIALLY BETWEEN 19Z-23Z. STILL HIGH UNCERTAINTY WHETHER SCATTERED CONVECTION WILL THREATEN THE KRDU VICINITY AFTER 21Z SO HAVE OPTED TO OMIT AT THIS TIME AND MONITOR CONDITIONS UPSTREAM. AFTER 03Z...BULK OF ISOLATED-SCATTERED CONVECTION WILL DIMINISH BY LATE EVENING THOUGH AN ISOLATED SHOWER WILL REMAIN POSSIBLE INTO THE OVERNIGHT PERIOD. AN INCREASINGLY MOIST LOW LEVEL AIR MASS SHOULD LEND TO THE DEVELOPMENT OF PATCHY STRATUS AND/OR FOG....ESPECIALLY AFTER 09Z. TUESDAY...EARLY MORNING LOW CLOUDS/FOG SHOULD LIFT INTO A BROKEN FLAT CU LAYER BY MID-LATE MORNING. AS ATMOSPHERE BECOME SLIGHTLY UNSTABLE..EXPECT SCATTERED CONVECTION ACROSS MOST OF CENTRAL NC IN THE MID-AFTERNOON-EVENING HOURS. THE PROBABILITY FOR EARLY MORNING FOG AND STRATUS WILL REMAIN RELATIVELY HIGH THROUGH THE REMAINDER OF THE WEEK. AFTERNOON CONVECTION MAY BE LESS LIKELY WEDNEDAY AFTERNOON AS A MID-UPPER LEVEL RIDGE BUILDS ACROSS THE REGION. THIS WEATHER FEATURE WILL WEAKEN IN RESPONSE TO A S/W TROUGH APPROACHING FROM THE NW. THIS TROUGH MAY INCREASE THE PROBABILITY OF SCATTERED CONVECTION LATE IN THE WEEK. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...WSS LONG TERM...BSD AVIATION...WSS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
131 AM EDT MON JUL 27 2015 .SYNOPSIS... HIGH PRESSURE WILL BRING SEASONABLE TEMPERATURES. THE HIGH WILL MOVE OFFSHORE MID WEEK. UNSETTLED WEATHER IS POSSIBLE NEXT WEEKEND AS A FRONT APPROACHES FROM THE WEST AND STALLS NEAR THE AREA. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 130 AM MONDAY...SHOWERS CONTINUE JUST OFF THE COAST WITH THE BEST COVERAGE ACROSS THE OFFSHORE WATERS. THESE SHOWERS HAVE NOT BEEN ABLE TO MAKE IT ONSHORE AS THEY HAVE BEEN STRUGGLING TO MAINTAIN THEMSELVES AS THEY PUSH WESTWARD AND INTO THE DRIER AIR. AS THE AIRMASS CONTINUES TO MODIFY AND THE COLUMN UNDERGOES FURTHER MOISTENING IN THE LOWER LEVELS...SOME OF THESE SHOWERS SHOULD BE ABLE TO MAKE IT ONTO THE MORE IMMEDIATE COAST. THE HIGH RESOLUTION HRRR MODEL CONTINUES TO SHOW A FEW EARLY MORNING SHOWERS BRIEFLY COMING ASHORE BEFORE DISSIPATING. WILL CARRY SLIGHT CHANCE OF A BRIEF SHOWER FOR MUCH OF THE BEACHES AND IMMEDIATE ADJACENT LOCATIONS. DEWPOINTS HAVE BEEN CREEPING HIGHER FROM E TO W AS THE LOW LEVELS CONTINUE TO SLOWLY MODIFY IN ONSHORE FLOW. THIS WILL SERVE AS A FLOOR...KEEPING TEMPS OVERNIGHT HIGHER THAN IN RECENT NIGHTS. ALSO...WITH MOISTENING IN THE LOW LEVELS CONTINUING...WE SHOULD SEE SOME PATCHY FOG DEVELOP. INLAND MOISTURE PROFILES ARE MOST CONDUCIVE FOR VISIBILITY RESTRICTIONS NEAR SUNRISE. WE ARE FORECASTING LOWS IN THE LOWER TO MID 70S. CONSIDERABLE CLOUD COVER...ESPECIALLY HIGH CLOUDS...WILL CONTINUE TO FILTER ACROSS THE EASTERN CAROLINAS FROM THE N AND W TONIGHT. LOWER CLOUDS WILL BE CONFINED TO THE MORE IMMEDIATE COAST IN ASSOCIATION WITH OFFSHORE/COASTAL SHOWERS. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...WEAK AMORPHOUS PRESSURE PATTERN WILL PREVAIL THROUGH THE PERIOD WITH A STALLED FRONT POSITIONED WELL OFFSHORE AND WEAK HIGH PRESSURE CENTERED TO THE NORTH AND EAST. A LOW MAY DEVELOP ALONG THE STALLED FRONT ON MONDAY...BUT EXPECT IT WILL HAVE NO REAL IMPACT ON LOCAL CONDITIONS. DEEP LAYER FLOW WILL BE NORTHWESTERLY AS AN UPPER TROUGH SLOWLY SWINGS OFF EASTERN CONUS WHILE FLOW NEAR THE SURFACE STAYS GENERALLY EASTERLY. THIS SETUP WILL BRING SEASONAL TEMPERATURES FOR MONDAY AND TUESDAY WITH VERY LITTLE DIFFERENCE IN THE READINGS BETWEEN BOTH DAYS. BEST CHANCES FOR CONVECTION WILL BE ON TUESDAY AS LAPSE RATES STEEPEN AND MODEST INSTABILITY IS INTRODUCED...WITH DEEP-LAYER MOISTURE PROFILES BECOMING MORE FAVORABLE. THE AFTERNOON SEA-BREEZE FRONT MAY ACT AS A TRIGGER TO TUESDAYS CONVECTION...ALONG WITH A STRENGTHENING PIEDMONT TROUGH. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 300 PM SUNDAY...SURFACE AND MID LEVEL RIDGING WED AND THU WILL KEEP THE REGION MOSTLY FREE OF PRECIP. MOISTURE WILL BE LIMITED EACH AFTERNOON BUT DO EXPECT THERE WILL BE SOME ISOLATED CONVECTION DEVELOPING ALONG THE SEA BREEZE WHICH WILL THEN PUSH INLAND. LIMITED SUPPORT ALOFT AND MARGINAL LAPSE RATES WILL KEEP COVERAGE IN THE SLIGHT CHANGE RANGE. UNCERTAINTY LINGERS DURING THE SECOND HALF OF THE PERIOD WITH RESPECT TO FRONT DROPPING IN FROM THE NORTHWEST. PREVIOUSLY THE MEDIUM RANGE GUIDANCE HAD BEEN CONSISTENT WITH STALLING THE BOUNDARY ALONG THE CAROLINA COAST FOR THE WEEKEND. THE LATEST FROM THE GFS AND ECMWF HAVE THE FRONT STALLING CLOSE TO THE WESTERN EDGE OF THE FORECAST AREA WITH DIURNAL CONVECTION AREA WIDE EACH AFTERNOON. COVERAGE INCREASES FOR THE WEEKEND AS 5H RIDGE RETREATS WEST AND DEVELOPING 5H TROUGH CAUSES SOUTHWEST FLOW ALOFT. DEEP MOISTURE SPREADS OVER THE SOUTHEAST NEXT WEEKEND WITH PRECIPITABLE WATERS EXCEEDING 2 INCHES AT TIMES. INCREASED MOISTURE COMBINED WITH MORE FAVORABLE MID LEVEL PATTERN PUSHES PRECIP CHANCES INTO THE HIGH CHC RANGE LATE IN THE WEEK. TEMPERATURES WILL BE WITHIN A FEW DEGREES OF CLIMO THROUGH FORECAST PERIOD. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... AS OF 06Z...MAIN CONCERN TONIGHT WILL BE FOG. THE POTENTIAL IS THERE PARTICULARLY INLAND AS RH`S HAVE ROCKETED UP FROM THIS EVENING. BUFKIT SHOWS FAVORABLE VERTICAL CHANGE IN HUMIDITIES...AS WELL AS LIGHT WINDS AT THE BOUNDARY LAYER. LOOK FOR FOG TO START TO SET UP AFTER 07Z...WITH GREATEST INTENSITY FROM 10-11Z. BELIEVE LOWEST VISIBILITIES WILL BE LBT.A QUICK BURNOFF IS IN STORE MONDAY WITH VFR CONDITIONS AT ALL TERMINALS EXPECTED BY 13Z. EXTENDED OUTLOOK...PREDOMINANTLY VFR THROUGH THE PERIOD...WITH ISOLATED AFTERNOON CONVECTION POSSIBLE TUESDAY THROUGH THURSDAY WITH SCATTERED ACTIVITY FRIDAY AND SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 AM MONDAY...WINDS WILL BE EASTERLY THROUGH THE NIGHT. WIND SPEEDS WILL BE UP TO 10 TO 15 KT...BUT ARE EXPECTED TO DECREASE DURING THE OVERNIGHT. SEAS WILL BE MAINLY 2 TO 3 FT WITH SOME 4 FT SEAS THROUGH LATE EVE ACROSS THE NORTHERN WATERS. A WEAK 11 SECOND SE SWELL WILL PERSIST. A SURFACE TROUGH ASSOCIATED WITH THE REMAINS OF A FRONTAL BOUNDARY WILL REMAIN STALLED TO OUR SOUTH...BUT MAY OSCILLATE SLIGHTLY NORTHWARD LEADING TO A SLIGHT SLACKING OF THE GRADIENT. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 300 PM SUNDAY...WEAK HIGH PRESSURE CENTERED TO THE NORTH AND EAST WILL KEEP WINDS GENERALLY LIGHT AND EASTERLY THROUGH THE PERIOD...WITH SEAS IN THE 2 TO 3 FT RANGE. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 300 PM SUNDAY...WEAK HIGH PRESSURE TO THE NORTH WILL SLIDE OFF THE COAST WED INTO THU...WITH LIGHT EASTERLY FLOW BECOMING MORE SOUTHEAST ON THU. GRADIENT CHANGES LITTLE ON FRI AS WEAK FRONT MOVING IN FROM THE NORTHWEST STALLS WEST OF THE COAST. WIND SPEEDS WILL REMAIN 10 KT OR LESS THROUGH THE PERIOD...EXCEPT ALONG THE COAST WHERE THE SEA BREEZE WILL CAUSE ONSHORE FLOW IN THE 10 TO 15 KT RANGE. SEAS 2 TO 3 FT THROUGH THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RJD/8 SHORT TERM...REK LONG TERM...III AVIATION...8
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
327 PM CDT MON JUL 27 2015 .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 318 PM CDT MON JUL 27 2015 RATHER WEAK SHORT WAVE OVER THE MID RED RIVER VALLEY AT MID AFTN. AREA OF MID LEVEL ALTOCU WITH THIS INTO PARTS OF NW MN AS WELL GFK-DTL REGION. STILL COUPLE OF SHOWERS IN THIS AREA AND WILL CONTINUE MENTION THRU 23Z. OTEHRWISE WARM AIR ALOFT SEEN ON VSBL SAT PIX WITH LACK OF CU FROM BISMARK AREA TO NEAR STANLEY ND TO ESTEVAN SK. HRRR AND OTHER VARIOUS WRF MODELS QUITE SIMILAR IN SHOWING ACTIVITY INCREASING 23Z-01Z IN ERN MT OR FAR WRN ND INTO SE SASK AND THEN EVENTUALLY SPREADING EAST AND NORTHEAST..WITH THREAT NOT INTO ERN ND TIL LIKELY AFTER 06Z. MOST SHORT RANGE MODELS ALSO SO A SECOND AREA OF STORMS IN ECNTRL SD INTO CENTRAL MN. ALL IN ALL BULK SHEAR IS PRETTY GOOD BUT MAIN MID LEVEL JET AROUND THE BASE OF THE 500 MB LOW IS STILL WEST AND NORTHWEST OF OUR AREA OVERNIGHT SO AT THIS POINT THE IDEA OF SEVERE OUTBREAK FOR ERN ND/NW MN POINTS TOWARD ISOLATED AT BEST AS SOME CLUSTERS OR A SQUALL LINE MOVES IN. COORD WITH VARIOUS OFFICES AND HAVE SLOWED DOWN THE POPS A BIT MORE. SUNNIER AND LESS WINDY FOR THURSDAY AS HIGH PRESSURE BUILDS IN. FOR THURSDAY NIGHT THROUGH MONDAY...STILL EXPECTING A RIDGE TO DEVELOP OVER THE WESTERN UNITED STATES WHILE LOW PRESSURE REMAINS OVER HUDSON BAY. THIS WILL PUT THE FA IN NORTHWEST FLOW FOR THE DURATION OF THE LONG TERM. THIS KEEPS THE FA IN A GENERALLY QUIET PERIOD ALTHOUGH THERE MAY BE SOME LOW END PCPN CHANCES AT TIMES. EXACTLY WHEN A TOUGH CALL AT THIS POINT WITH NO DECENT AGREEMENT BETWEEN SOLUTIONS. TEMPS SHOULD REMAIN NEAR OR SLIGHT BELOW NORMAL FOR LATE JULY. .LONG TERM...(WEDNESDAY THROUGH MONDAY) ISSUED AT 318 PM CDT MON JUL 27 2015 ONGOING COVNECTION EXITING THE RRV 12Z TUES AND EXITING NW MN BY MIDDAY. DRY SLOT COMING IN AND PRETTY STRONG 925 MB WINDS ON THE SOUTH SIDE OF THE UPPER LOW MOVES INTO CNTRL ND TUES AFTN AND INTO PARTS OF NE/ECNTRL ND LATE TUES AFTN/EARLY EVE. AT THIS POINT...MAY FLIRT WITH HIGH WIND WARNING CRITERIA FOR A SHORT TIME DVL BASIN WITH ADVISORY CONDITIONS FOR A FEW HOURS OTHER AREAS IN ERN ND. NO HEADLINES WILL BE ISSUED THIS FCST AS IT WILL PAST 18Z TUES AND GIVES MID SHIFT TIME TO ISSUE PRODUCTS AS NEEDED. WRAPAROUND CLOUDS AND A FEW SHOWERS TO MOVE INTO NE ND/NW MN TUES NIGHT..EXITING LAKE OF THE WOODS WED MORNING. BREEZY WEDNESDAY WITH A MIX OF CLOUD/SUN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 109 PM CDT MON JUL 27 2015 LOWER BASED CUMULUS FIELD FORMED DOWN IN THE SOUTHEAST FA WHERE THERE WAS SOME FOG THIS MORNING. IT QUICKLY EXPANDED UP THE RED RIVER VALLEY THROUGH LATE MORNING. THINKING IT SHOULD DIMINISH THRU THE AFTERNOON AS WARMER MID LEVEL TEMPS MOVE IN. FAIRLY STEADY WINDS SHOULD HOLD UP THRU THE NIGHT AND THEN THE GUSTS SHOULD PICK AGAIN BY MID TUE MORNING. PUSHED BACK THE ONSET OF TSTMS TO 09Z AT KDVL AND 11Z INTO KGFK/KFAR. MODELS SEEM TO AGREE ON LATER TIMING THAN PREVIOUS SET OF TAFS...BUT THERE MAY STILL BE A LITTLE WIGGLE ROOM IN THERE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...RIDDLE LONG TERM...GODON/RIDDLE AVIATION...GODON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1236 AM CDT MON JUL 27 2015 .UPDATE... ISSUED AT 1236 AM CDT MON JUL 27 2015 LATEST LOCAL RADAR SHOWS AN AREA OF SHOWERS AND SCATTERED THUNDERSTORMS FROM EARLIER IN THE EVENING CURRENTLY LOCATED OVER GRANT/SIOUX/EMMONS COUNTIES. MOVEMENT ON THIS AREA APPEARS TO BE TAKING ON MORE OF A NORTHEAST TREND...AND THIS IS SOMEWHAT SUPPORTED IN THE LATEST HRRR AND RAP13. THUS...HAVE COORDINATED WITH ABERDEEN WFO TO CONTINUE MENTION OF SHOWERS/THUNDERSTORMS SOUTH CENTRAL OVERNIGHT EXTENDING INTO THE SOUTHERN JAMES RIVER VALLEY. REGIONALLY...THE NEXT AREA OF THUNDERSTORMS WOULD BE THE NORTHWEST OVERNIGHT IN CLOSE PROXIMITY TO THE DEVELOPING WARM FRONT/LOW LEVEL JET. THE NAM/HRRR/RAP13 SUGGESTS SHOWERS AND THUNDERSTORMS GRAZING OUR NORTHWEST CORNER TOWARD 12Z MONDAY. REST OF FORECAST IS ON TRACK. UPDATE ISSUED AT 1039 PM CDT SUN JUL 26 2015 SEVERE THUNDERSTORM WATCH HAS EXPIRED. ONLY A SMALL AREA OF THUNDERSTORMS REMAINS...OVER GRANT AND SIOUX COUNTIES. KEPT HIGHER CHANCES OF PRECIPITATION THERE THROUGH MIDNIGHT CDT...WITH SLIGHT CHANCES TO THE NORTHEAST ALONG THE EARLIER CONVECTION AXIS. ATTENTION THEN TURNS TO LATER TONIGHT WITH POTENTIAL CONVECTION OVER NORTHWESTERN NORTH DAKOTA. UPDATE ISSUED AT 840 PM CDT SUN JUL 26 2015 QUICK UPDATE TO TAKE SEVERAL COUNTIES OUT OF THE WATCH. ALL NORTHERN TIER COUNTIES ARE NOW OUT...AND TOOK OUT SOME WESTERN COUNTIES. THOSE REMAINING IN THE WATCH UNTIL 10 PM CDT INCLUDE MCLEAN...MERCER...OLIVER...MORTON...HETTINGER...GRANT. CONVECTION HAS WEAKENED SIGNIFICANTLY NORTH...AND EXPECT SOUTHERN END OF LINE TO DIMINISH GRADUALLY THIS EVENING. HAD TO ADD SOME MENTION OF CHANCE OF SHOWERS AND THUNDERSTORMS EASTWARD INTO SHERIDAN/WELLS/BURLEIGH/KIDDER...AS STORMS HOLDING TOGETHER. DO NOT EXPECT SEVERE STORMS OUTSIDE THE WATCH AREA...EXCEPT PERHAPS FOR ADAMS/SIOUX COUNTIES. UPDATE ISSUED AT 648 PM CDT SUN JUL 26 2015 A LINE OF STRONG TO SEVERE STORMS CONTINUES FROM BOTTINEAU/ROLETTE COUNTY SOUTHWESTWARD TO BOWMAN COUNTY. SEVERE THUNDERSTORM WATCH CONTINUES FOR THIS AREA AND EAST TO PIERCE/ROLETTE TO MORTON/GRANT...BUT WILL ALLOW THE WATCH TO EXPIRE FOR SOME OF THE WESTERN COUNTIES...NAMELY BURKE...MOUNTRAIL...MCKENZIE AND BILLINGS COUNTIES. LINE OF STORMS IS MAINLY ALONG A SURFACE FRONTAL BOUNDARY...WHICH HAS MOVED EASTWARD DURING THE LATE AFTERNOON AND EVENING. ADJUSTED HOURLY TEMPS/WINDS TO ACCOUNT FOR LATEST OBSERVATIONS AND TRENDS. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 209 PM CDT SUN JUL 26 2015 BLENDED THE CURRENT POPS WITH THE HRRR ENSEMBLE FOR THE REMAINDER OF THE AFTERNOON AND EVENING. AS OF 2 PM CDT THUNDERSTORMS HAVE INITIATED ALONG THE FRONTAL BOUNDARY IN NORTHWEST NORTH DAKOTA. BUFKIT 12Z SOUNDINGS SHOW A CAP IN PLACE SUNDAY AFTERNOON BIS-JMS SO USED THIS AS THE EASTWARD EXTENT FOR THE CONVECTION THIS AFTERNOON AND EVENING. 20Z WATER VAPOR IMAGE SHOWS WEAK TROUGH MOVING THROUGH NORTHEAST MONTANA WITH THE MAIN UPPER LOW COMING ON SHORE ACROSS WASH/OR. AS THE FLOW ALOFT BECOMES PARALLEL WITH THE COLD FRONT IT WILL ONLY MAKE IT THROUGH WEST CENTRAL NORTH DAKOTA SUNDAY EVENING...THEN LIKELY RETREAT TO THE NORTHWEST AS INCREASING LOW LEVEL SOUTHEAST FLOW BECOMES MORE PREDOMINANT LATE TONIGHT IN RESPONSE TO THE UPPER LOW MOVING TO MONTANA BY MONDAY MORNING. AS THIS HAPPENS THE FOCUS FOR THUNDERSTORMS TONIGHT WILL DIMINISH CENTRAL AND RETURN TO THE NORTHWEST. ON MONDAY MID LEVEL COOLING AND INCREASING MID LEVEL ADIABATIC LAPSE RATES WILL CREATE IMPRESSIVE CAPE VALUES IN EXCESS OF 4000. WITH COLD FRONTAL BOUNDARY SET TO HELP BREAK THE CAP SEVERE THUNDERSTORMS ARE ANTICIPATED ACROSS THE NORTHWEST MONDAY MORNING AND ALONG AND WEST OF HIGHWAY 83 BY AFTERNOON. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 209 PM CDT SUN JUL 26 2015 THE MAIN FOCUS FOR THE LONG TERM IS THE POTENTIAL FOR A SEVERE WEATHER OUTBREAK TOMORROW EVENING. AN UPPER LEVEL TROUGH WILL DIG INTO THE NORTHERN ROCKIES TOMORROW. THIS WILL PROVIDE AMPLE UPPER LEVEL ASCENT ACROSS THE NORTHERN PLAINS AHEAD OF THE TROUGH. ADDITIONALLY...A DEEP SURFACE LOW AND COLD FRONT WILL DEVELOP ACROSS EASTERN MONTANA...WITH A WARM FRONT DRAPED ACROSS THE INTERNATIONAL BOARDER. AFTERNOON HEATING ACROSS A VERY WARM AND MOIST WARM SECTOR WILL LIKELY YIELD CAPE VALUES GREATER THAN 3000 J/KG. AFTERNOON CAPING DUE TO AN ELEVATED WARM LAYER WILL LIKELY INHIBIT CONVECTION FROM FORMING ACROSS ALL BUT FAR WESTERN NORTH DAKOTA UNTIL THE EARLY EVENING HOURS...WHEN MID LEVEL COOLING AND STRONGER FORCING ARRIVES VIA THE UPPER LEVEL WAVE. INITIALLY...ISOLATED SUPERCELLS ARE POSSIBLE...WITH VERY LARGE HAIL...DAMAGING WINDS AND A FEW TORNADOES. ONCE THE COLD FRONT AND UPPER LEVEL WAVE BEGINS PUSHING EASTWARD ACROSS THE STATE...A TRANSITION TO DAMAGING LINE SEGMENTS (WITH VERY STRONG WINDS AND SOME HAIL) APPEARS LIKELY. DURING THE DAY TUESDAY...A SECONDARY PRESSURE SURGE WILL PRODUCE VERY STRONG WINDS ACROSS THE REGION. WITH PRESSURE RISES BETWEEN 15 AND 20 MB/6HOUR...AND A STRONG DOWNSLOPE COMPONENT...WIND GUSTS AROUND 50 MPH ARE POSSIBLE. TEMPERATURES TUESDAY WILL BE CONSIDERABLY COOLER WITH READINGS ON AVERAGE 20 TO 30 DEGREES COOLER THAN MONDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1236 AM CDT MON JUL 27 2015 THERE IS SOME POTENTIAL FOR STRATUS CLOUDS/IFR CIGS TO AFFECT KBIS/KJMS TOWARD 12Z MONDAY...HOWEVER WILL GIVE THIS SOME ADDITIONAL TIME BEFORE GOING WITH A PREDOMINATE CLOUD GROUP. AN AREA OF SHOWERS AND THUNDERSTORMS SOUTH OF KBIS/KJMS THROUGH 12Z MONDAY COULD PRODUCE LOWER CLOUDS INTO THESE TERMINALS WITH A SOUTH TO SOUTHEAST WIND. OTHERWISE...A SIGNIFICANT COLD FRONT WILL SUPPORT THE DEVELOPMENT OF SEVERE THUNDERSTORMS FROM 21Z MONDAY THROUGH THEN END OF THE TAF PERIOD. WILL CONTINUE WITH A VCTS AND TRY TO BECOME MORE SPECIFIC WITH THE 12Z TAF ISSUANCE. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...WAA LONG TERM...AJ AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1142 PM CDT SUN JUL 26 2015 .UPDATE... ISSUED AT 929 PM CDT SUN JUL 26 2015 LITTLE TO NO CHANGE IN THE FORECAST AS CONVECTION CONTINUES TO WEAKEN WITH SUNDOWN. KEPT POPS IN THE NORTHERN DVL BSN FOR A COUPLE MORE HOURS. UPDATE ISSUED AT 635 PM CDT SUN JUL 26 2015 CONVECTION IN CENTRAL ND CONTINUES TO SLOWLY WORK EAST NEAR THE DVL BSN THIS EVENING. CURRENT FORECAST FOR A CHC OF THUNDER IN THE DVL BSN REMAINS ON TRACK WITH LITTLE TO NO POPS ELSEWHERE...THIS IS IN LINE WITH CURRENT HRRR AND OTHER CAMS. MIXING A LITTLE STRONGER OVERNIGHT TONIGHT COMPARED TO LAST NIGHT WHEN SOME PATCHY FOG DEVELOPED. WILL LEAVE FOG OUT OF THE FORECAST FOR TONIGHT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT) ISSUED AT 321 PM CDT SUN JUL 26 2015 WEAK SFC LOW IN WCNTRL ND WITH A TROUGH FROM NEAR WATFORD CITY TO MINOT TO BRANDON MANITOBA. NOT UNEXPECTEDLY CONVECTING FIRING JUST BEHIND THE TROUGH AND SHOULD CONTINUE TO SO INTO THE EVENING AS BOUNDARY SLIDES SLOWLY EAST. WILL MAINTAIN THE LOW POP IN AREAS JUST NORTHWEST OF DEVILS LAKE THRU MID EVENING PER 1 PM UPDATE. SPC ADDED THIS AREA INTO A SLIGHT RISK. EASTWARD ADVANCE WILL BE VERY LIMITED DUE TO WARM AIR ALOFT AND LACK OF ANY BOUNDARY. EXPECT THE STORMS TO DIMINISH WITH SUNSET. HRRR HAS FOLLOWED THIS TREND ALL DAY AND HAS BEEN CONSISTENT. MONDAY WILL BE UNDER THE WARM AIR ALOFT AND DRY DURING THE DAY. SFC LOW WILL STRENGTHEN IN WCNTRL ND MON AFTN AND LOOK FOR STRONG INSTABILITY TO BUILD IN NW ND DURING THE AFTN JUST NORTH OF THE SFC AND NR THE WARM FRONT WHICH WILL EXTEND FROM NW ND INTO SOUTHERN MANITOBA. SPC THINKING SVR STORMS FIRING ALONG THE LOW AND WARM FRONT MID AFTN MONDAY AND THEN OVER TIME ORGANIZING AND SPREADING EAST AS A SQUALL LINE INTO ERN ND BUT MOST LIKELY MID TO LATE EVENING AND OVERNIGHT. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 321 PM CDT SUN JUL 26 2015 UPPER LOW WILL MOVE INTO SE SASK AND MANITOBA TUES-TUES NIGHT PERIOD. COLD FRONT WILL SWING THROUGH BEHIND THE TSTMS LATE MONDAY NIGHT INTO TUESDAY...FOLLOWED BY DRY SLOT OVER ALL BUT THE FAR EAST TUESDAY MIDDAY-AFTN. BREEZY SOUTHWEST WINDS EXPECTED. A TAD COOLER WEDNESDAY AS COOLER AIR ALOFT MOVES OVER AS UPPER LOW MOVES INTO NW ONTARIO. SW EDGE OF SOME SHOWERS WILL IMPACT FAR NE ND/NW MN TUES NIGHT INTO A PART OF WED WITH THIS SYSTEM. LOOK FOR WINDY CONDITIONS WEDNESDAY FROM THE WEST. WEDNESDAY NIGHT-SUNDAY...MID/UPPER LEVEL RIDGING IS EXPECTED TO RETROGRADE INTO THE SOUTHWEST CONUS WITH WEST TO NORTHWESTERLY FLOW ALOFT BECOMING MORE ENTRENCHED DURING THIS TIME OVER THE N PLAINS. A GENERALLY QUIET WEATHER PATTEN IS EXPECTED THROUGH THE END OF THE WORK WEEK...WITH ONLY SOME LOW-END POPS BY THE WEEKEND GIVEN THE POTENTIAL FOR SOME EMBEDDED DISTURBANCES IN THE FLOW TO DROP OUT OF && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1135 PM CDT SUN JUL 26 2015 VFR TONIGHT WITH LIGHT SOUTH WINDS. WINDS GUSTING TOMORROW AFTN AROUND 25 KTS. CONVECTION INITIATES IN WESTERN ND AND MOVES EAST INTO THE DVL BSN LATE IN THE TAF PERIOD. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JK SHORT TERM...RIDDLE LONG TERM...MAKOWSKI/RIDDLE AVIATION...JK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
207 AM EDT MON JUL 27 2015 .SYNOPSIS... A WEAK FRONTAL BOUNDARY ACROSS NORTHERN OHIO WILL MOVE VERY SLOWLY TO THE SOUTH OVERNIGHT. SOME THUNDERSTORMS WILL BE POSSIBLE IN SOUTHERN LOCATIONS MONDAY WHEN THE WEAK BOUNDARY IS FORECAST TO BE NEAR THE OHIO RIVER. VERY WARM TEMPERATURES AND MAINLY DRY WEATHER WILL ACCOMPANY HIGH PRESSURE ON TUESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... A WEAK FRONTAL BOUNDARY ACRS THE NRN CWFA THIS EVENING WILL SHOW ONLY A LITTLE PROGRESS TO THE SOUTH OVERNIGHT. IN FACT...IT MAY END UP LOSING ITS IDENTITY IN TERMS OF FRONTAL CONVERGENCE BY MONDAY MORNING. OF MORE CONCERN FOR THE OVERNIGHT HOURS IS AN EMBEDDED DISTURBANCE CURRENTLY MOVING THROUGH CENTRAL INDIANA. THIS FEATURE WILL MOVE SOUTHEAST OVERNIGHT. THE HRRR IS THE ONLY MODEL TRYING TO CAPTURE THE AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS OVER CENTRAL INDIANA...MOVING IT SOUTHEAST BUT WEAKENING IT AS IT PUSHES INTO OUR AREA. BASED ON LATEST RADAR AND TRAJECTORY...FEEL THE NEED TO BUMP UP POPS FOR MEASURABLE PCPN TO LIKELY...MAINLY FOR THE DAYTON METRO AND POINTS TOWARD THE SW CWFA (TRI-STATE) REGION THROUGH AT LEAST THE EARLY MORNING HOURS. THEREAFTER...THERE SHOULD BE CONTINUED WEAKENING TREND AS THE FEATURE MOVES THROUGH THE REMAINDER OF OUR SE CWFA. WITH CONSIDERABLE CLOUDINESS...LOWS WILL RANGE FROM THE MID 60S TO THE LOWER 70S. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... THE FRONTAL BOUNDARY WILL CONTINUE ITS SOUTHWARD PROGRESS TO THE VICINITY OF THE OHIO RIVER ON MONDAY. THUNDERSTORMS MAY DEVELOP AGAIN ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA WHERE FRONTAL CONVERGENCE AND HIGHER INSTABILITY WILL COME INTO PLAY. LOCATIONS NORTH OF I-70 MAY EXPERIENCE DRY WEATHER DUE TO HIGH PRESSURE AND A SLIGHTLY LESS HUMID AIRMASS WORKING INTO NORTHERN OHIO. ANTICIPATE SEASONABLE HIGHS IN THE MID AND UPPER 80S...A BIT BELOW GUIDANCE. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... MID LEVEL RIDGE CENTERED OVER THE NATIONS MID SECTION TO BUILD EAST INTO THE OHIO VALLEY/GREAT LAKES REGION EARLY THIS WEEK. WILL LIMIT ANY MENTION OF THUNDERSTORMS TO SLIGHT CHANCE ACRS THE FAR S-SW CLOSER TO THE WARM FRONTAL BOUNDARY DUE TO LACK OF SIGNIFICANT FORCING. HEIGHT/THICKNESS RISES WILL LEAD TO A WARM UP OF TEMPERATURES...WITH HIGHS ON TUESDAY RANGING FROM THE UPPER 80S NW TO THE LOWER 90S SE. PROGRESSIVE MID LEVEL TROF TO MOVE FROM THE NRN PLAINS/SRN CANADA ACRS THE GREAT LAKES AT MID WEEK FLATTENING OUT THE NRN PORTION OF THE RIDGE. THIS WILL ALLOW A SFC COLD FRONT TO PUSH THRU THE REGION EARLY THURSDAY. MODEL SOLNS HAVE TRENDED A LTL FASTER WITH THIS FRONTAL PASSAGE. HAVE CONTINUED MENTION OF LOW CHANCE POPS FOR THUNDERSTORMS WED AFTN AS MOISTURE AND MODERATE INSTBY RETURNS. WARM TEMPERATURES TO CONTINUE WEDNESDAY AHEAD OF THE FRONT WITH HIGHS FROM THE UPPER 80S NW TO THE LOWER 90S SE. THUNDERSTORM CHANCES INCREASE WEDNESDAY NIGHT INTO EARLY THURSDAY AS THE FRONT APPROACHES. AS SFC HIGH PRESSURE BEGINS TO NOSE IN THURSDAY...DRY CONDITIONS WILL RETURN. TEMPERATURES WILL BE A LTL COOLER WITH HIGHS FROM THE LOWER 80S NW TO THE UPPER 80S SE. NORTHWEST FLOW ALOFT WITH SFC HIGH PRESSURE BUILDING ACRS THE REGION LATE IN THE WEEK INTO NEXT WEEKEND. HIGH TEMPERATURES ON BOTH FRIDAY AND SATURDAY WILL BE CLOSE TO NORMAL WITH HIGHS IN THE LOWER AND MIDDLE 80S. TIMING DIFFERENCES EXIST REGARDING PCPN LATE NEXT WEEKEND. GFS IS QUICKER WITH ECMWF BEING SLOWER. HAVE HELD OFF ANY MENTION OF PCPN UNTIL SUNDAY AFTN AND LIMITED MENTION TO SLIGHT CHANCE ACRS THE NORTH WITH THE APPROACH OF THE NEXT FRONT. TEMPERATURES CONTINUE CLOSE TO NORMAL WITH HIGHS FROM THE LOWER 80S NORTH TO THE MID/UPR 80S SOUTH SUNDAY. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... VERY WEAK WIND FIELD WITH A FRONT DRAPED SOUTH OF THE REGION IN KENTUCKY WILL SEE SHOWERS SCATTERED ABOUT WITH A GRADUAL EASTWARD MOVEMENT THROUGH DAYBREAK. HIGH PRESSURE OVER THE GREAT LAKES REGION WILL STRENGTHEN TODAY AND THE EAST WIND IN OHIO VALLEY WILL TURN MORE NE TO N AND SHIFT THE SOURCE REGION FOR SHOWER INITIATION TO THE SOUTHWEST...KEEPING KCMH/KLCK OUT OF ACTIVITY TODAY. KCVG AND KLUK SHOULD HAVE THE BEST CHANCES FOR SHOWERS THIS AFTERNOON AND THE GRADIENT WILL LIGHTEN BACK UP WITH THE SETTING SUN. EXPECT THE VERY MOIST AIR FROM EARLIER SHOWERS TO HAVE MVFR FOG TO DEVELOP. OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY INTO THURSDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...CONIGLIO NEAR TERM...HICKMAN SHORT TERM...CONIGLIO LONG TERM...AR AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
958 PM EDT TUE JUL 28 2015 .SYNOPSIS... HIGH PRESSURE WILL PERSIST OVER THE REGION THROUGH WEDNESDAY...WITH TEMPERATURES REMAINING ABOVE NORMAL. A WEAK COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON THURSDAY AND SETTLE JUST SOUTH OF THE REGION ON FRIDAY. THE FRONT WILL LIKELY REMAIN STALLED JUST SOUTH OF THE AREA THROUGH THE WEEKEND...WITH COOLER TEMPERATURES EXPECTED. MOISTURE SHOULD INCREASINGLY RETURN NORTHWARD OVER THE FRONT THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... 0200 UTC UPDATE...POPS HAVE BEEN REDUCED OVER MOST OF THE AREA PER RADAR TRENDS...WITH THE EXCEPTION OF THE NW NC PIEDMONT WHERE ACTIVITY IS MOST PRONOUNCED. ONLY MINOR CHANGES WERE MADE TO TEMPERATURES AND DEW POINTS OVERNIGHT. SKY COVER WAS UPDATED FROM INFRARED SATELLITE IMAGERY. 0000 UTC UPDATE...POPS HAVE BEEN ADJUSTED TO ACCOUNT FOR MORE CONVECTION MOVING TOWARD THE NW NC PIEDMONT...AND ACTIVITY OVER THE SC PIEDMONT. QPF WAS ADJUSTED ACCORDINGLY. 2315 UTC UPDATE...POPS HAVE BEEN INCREASED IN THE NW NC PIEDMONT...THE SOUTHERN INTERSTATE 77 CORRIDOR...AND THE SW NC MOUNTAINS PER RADAR TRENDS. QPF HAS BEEN ADJUSTED ACCORDINGLY. SKY COVER WAS UPDATED FROM VISIBLE SATELLITE IMAGERY...WITH INCREASES IN THE PIEDMONT AND MOUNTAINS...AND DECREASES IN BETWEEN. 2100 UTC UPDATE...POPS HAVE BEEN RAISED ALONG THE SOUTHERN INTERSTATE 77 CORRIDOR PER RADAR TRENDS...AND LOWERED IN THE SC INTERSTATES 85 CORRIDOR. 1940 UTC UPDATE...POPS AND QPF HAVE BEEN ADJUSTED TO FAVOR THE INTERSTATE 85 CORRIDOR PER RADAR TRENDS. SKY COVER WAS UPDATED FROM VISIBLE SATELLITE IMAGERY. AS OF 230 PM...CONVECTION WILL CONTINUE TO DEVELOP AND DRIFT TOWARD THE S-SE THIS AFTN...AS SUBTLE SHORTWAVE ENERGY ROUNDS THE EASTERN PERIPHERY OF A LARGE UPPER LEVEL HIGH. THE LATEST HRRR AND THE 12Z HIGH-RES WINDOWS ARE IN REALLY GOOD AGREEMENT ON THE TRENDS...SO I THINK THE POP GRIDS ARE ON TRACK...SINCE THEY WERE BLENDED WITH THOSE CAM POPS EARLIER. AS FOR SEVERE THREAT...WHILE THE STORMS HAVE BEEN GETTING FAIRLY TALL...THE FREEZING LEVEL ABOVE 15 KFT...AND LOW-MOD DCAPE OF 600-800 J/KG IS KEEPING THE MICROBURST THREAT IN CHECK. THERE IS ALSO A HEAVY RAIN THREAT...AS PWATS ARE 1.8-2.0" ACRS THE PIEDMONT...WITH SLOW STORM MOTIONS. TONIGHT...WEAK LOW PRES OVER SOUTHERN GA...AND HIGH PRES TO THE NORTH OF THE AREA WILL KEEP A LIGHT S/SE FLOW ACRS THE CWFA. THIS MAY BE ENUF TO ALLOW FOR LINGERING SHRA AND A FEW EMBEDDED TSTMS WELL PAST SUNSET. I HAVE POPS ON A SLOW DIMINISHING TREND FOR THE TONIGHT PERIOD...TO SLGT CHC BY DAYBREAK WED. LOWS IN THE MID-UPR 60S IN THE MTNS AND LWR-MID 70S PIEDMONT. ON WEDNESDAY...THE SYNOPTIC PATTERN WILL NOT CHANGE MUCH FROM TODAY...WITH 500 MB HIGH PRES CONTINUING TO NOSE N AND E INTO THE AREA FROM THE SOUTHERN PLAINS. HOWEVER...THE OP MODELS ALL RESOLVE ANOTHER VORT MAX DRIFTING SOUTH AROUND THE RIDGE ACRS THE OHIO VALLEY. THIS MAY HELP TRIGGER CONVECTION. THE LLVLS WILL BE SIMILAR...WITH ELEVATED DEWPTS IN THE 70S ACRS THE PIEDMONT. CAPE SHUD BE BACK ABOVE 1500 J/KG OR SO WITH VERY WEAK SHEAR. THE CAMS THAT GO OUT THRU TOMORROW SHOW SIMILAR CONVECTIVE TRENDS AS TODAY. SO WILL GO WITH HIGH-END CHC TO LIKELY POPS. SEVERE THREAT WILL REMAIN LOW WITH MOIST MID LVLS. A SMALL EXCESSIVE RAIN THREAT WILL CONTINUE. HIGHS AROUND PERSISTENCE IN THE 80S MTNS AND LWR-MID 90S PIEDMONT. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... AS OF 140 PM TUESDAY...RETROGRESSION OF THE SUBTROPICAL HIGH INTO THE SOUTHERN ROCKIES/HIGH PLAINS WILL OCCUR THROUGHOUT THE SHORT TERM PERIOD...AS A SERIES OF SHORT WAVES CARVE OUT A LONG WAVE TROUGH ACROSS MUCH OF EASTERN NORTH AMERICA BY THE END OF THE PERIOD. THIS WILL INTRODUCE A (RATHER WEAK) FRONTAL BOUNDARY INTO OUR AREA BY THURSDAY. MEANWHILE...SLIGHT COOLING OF THE MID-LEVEL TEMPS AND CONTINUED HIGH DEWPOINT TEMPERATURES...ALONG WITH THE APPEARANCE OF THE BOUNDARY SHOULD SUPPORT CONTINUED GOOD CHANCES OF CONVECTION THURSDAY AFTERNOON...WITH PERHAPS A BETTER CHANCE FOR A FEW PULSE-SEVERE STORMS WITHIN A MORE UNSTABLE ENVIRONMENT. A DEVELOPING CONSENSUS IN SHORT TERM MODEL GUIDANCE INDICATES THE UPPER TROUGH AXIS WILL BE EAST OF THE FORECAST AREA BY FRI MORNING...TAKING THE FRONTAL BOUNDARY ALONG WITH IT. ALTHOUGH THICKNESS VALUES WILL NOT SUPPORT AN APPRECIABLE COOL DOWN (REALLY ONLY TAKING MAXES BACK TO NEAR-NORMAL LEVELS)...THERE WILL BE A NOTICEABLE CHANGE IN RELATIVE HUMIDITY ACROSS MUCH OF THE AREA FRI AFTERNOON...AS DEWPOINTS COULD MIX OUT INTO THE 50S. THE RESULT WILL BE SMALL (AT BEST) CHANCES FOR CONVECTION FRI AFTERNOON. ALTHOUGH SMALL POPS WILL BE ADVERTISED...MAINLY HIGHLIGHTING SOUTHERN AREAS NEARER THE BOUNDARY...EVEN THESE MAY PROVE TO BE ON THE HIGH SIDE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 210 PM TUESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SATURDAY WITH A BROAD UPPER TROF CENTERED OVER ONTARIO AND QUEBEC AND VERY BROAD UPPER RIDGING IN PLACE OVER THE WESTERN CONUS. THIS GENERAL PATTERN IS EXPECTED TO REMAIN IN PLACE THROUGH THE PERIOD WITH SOME DEAMPLIFICATION OF THE UPPER TROF POSSIBLE TOWARDS THE END OF THE PERIOD. AT THE SFC...RIDGING WILL SPREAD BACK OVER THE CWFA FROM THE NW BY THE START OF THE PERIOD AND LINGER INTO EARLY NEXT WEEK...GRADUALLY GETTING WEAKER. THE ECMWF STILL TRIES TO SPIN UP SOME SORT OF SFC LOW TO OUR SOUTH BY THE END OF THE PERIOD...HOWEVER THE GFS APPEARS LESS BULLISH ON LOW DEVELOPMENT NOW THAN IT HAS OVER THE PAST COUPLE OF DAYS. ALSO OF NOTE...THE LONG RANGE MODEL GUIDANCE IS NOW KEEPING THE PLUME OF DEEPER LYR MOISTURE FARTHER SOUTH AND EAST COMPARED TO PREVIOUS GUIDANCE. THIS WILL ALLOW FOR LOWER OVERALL POPS FOR MOST OF THE PERIOD. AS FOR THE SENSIBLE FCST...WE CAN EXPECT MOSTLY DIURNAL CHANCES FOR SCT CONVECTION EACH DAY/EVENING WITH THE BEST CHANCES OVER THE SE ZONES. TEMPS WILL START OUT RIGHT AROUND NORMAL AND REMAIN NEAR NORMAL THROUGH THE PERIOD. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...CONVECTION AND ASSOCIATED RESTRICTIONS WILL REMAIN POSSIBLE THIS EVENING. WITH RAIN HAVING ALREADY OCCURRED...AND MORE POSSIBLE...DAYBREAK MVFR FOG SEEMS LIKELY. MODEL TIME HEIGHTS SUPPORT A CIG AT AROUND 6000 FT FOR MUCH OF THE FORECAST...BUT SHOW SUBSTANTIAL MOISTURE MUCH LOWER...AND DAYBREAK FOG MAY BE ACCOMPANIED BY AN MVFR CIG...AND PERHAPS EVEN LOWER. ANOTHER ROUND OF CONVECTION IS EXPECTED WEDNESDAY AFTERNOON AS THE PATTERN CHANGES LITTLE. LIGHT WINDS WILL GENERALLY FAVOR THE S. ELSEWHERE...CONVECTION AND ASSOCIATED RESTRICTIONS CANNOT BE RULED OUT THIS EVENING...ALTHOUGH THE BEST COVERAGE OS EAST OF THE FOOTHILLS. DAYBREAK FOG IS LIKELY...AS MANY SITES HAD RAIN OR MAY RECEIVE SOME THIS EVENING...AND GUIDANCE IS LEANING IN THAT DIRECTION. THE WORST RESTRICTIONS WOULD BE AT KAVL AND KHKY. MODEL TIME HEIGHTS FAVOR LOW VFR CIGS AT AROUND 4500 TO 6000 FEET...BUT ENOUGH LOW LEVEL MOISTURE IS PRESENT TO ALLOW FOR DAYBREAK MVFR CIGS WHERE FOG OCCURS...AND POSSIBLE EVEN LOWER CIGS. YET ANOTHER AROUND OF CONVECTION IS EXPECTED WEDNESDAY AFTERNOON IN A PERSISTENT UPPER LEVEL PATTERN. LIGHT WINDS WILL FAVOR THE S. OUTLOOK...AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE ATLANTIC STATES LATE IN THE WEEK...WITH THE LIKELY PASSAGE OF A COLD FRONT ON FRIDAY. THE POTENTIAL FOR CONVECTION WILL INCREASE THROUGH FRIDAY...THEN DECREASE BEHIND THE FRONT ON SATURDAY. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-00Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 83% HIGH 90% HIGH 98% HIGH 100% KHKY HIGH 83% HIGH 83% HIGH 94% HIGH 100% KGMU HIGH 100% HIGH 91% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 87% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JPT NEAR TERM...ARK/JAT SHORT TERM...JDL LONG TERM...JPT AVIATION...JAT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
712 PM EDT TUE JUL 28 2015 .SYNOPSIS... HIGH PRESSURE WILL PERSIST OVER THE REGION THROUGH WEDNESDAY...WITH TEMPERATURES REMAINING ABOVE NORMAL. A WEAK COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON THURSDAY AND SETTLE JUST SOUTH OF THE REGION ON FRIDAY. THE FRONT WILL LIKELY REMAIN STALLED JUST SOUTH OF THE AREA THROUGH THE WEEKEND...WITH COOLER TEMPERATURES EXPECTED. MOISTURE SHOULD INCREASINGLY RETURN NORTHWARD OVER THE FRONT THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH WEDNESDAY/... 2315 UTC UPDATE...POPS HAVE BEEN INCREASED IN THE NW NC PIEDMONT...THE SOUTHERN INTERSTATE 77 CORRIDOR...AND THE SW NC MOUNTAINS PER RADAR TRENDS. QPF HAS BEEN ADJUSTED ACCORDINGLY. SKY COVER WAS UPDATED FROM VISIBLE SATELLITE IMAGERY...WITH INCREASES IN THE PIEDMONT AND MOUNTAINS...AND DECREASES IN BETWEEN. 2100 UTC UPDATE...POPS HAVE BEEN RAISED ALONG THE SOUTHERN INTERSTATE 77 CORRIDOR PER RADAR TRENDS...AND LOWERED IN THE SC INTERSTATES 85 CORRIDOR. 1940 UTC UPDATE...POPS AND QPF HAVE BEEN ADJUSTED TO FAVOR THE INTERSTATE 85 CORRIDOR PER RADAR TRENDS. SKY COVER WAS UPDATED FROM VISIBLE SATELLITE IMAGERY. AS OF 230 PM...CONVECTION WILL CONTINUE TO DEVELOP AND DRIFT TOWARD THE S-SE THIS AFTN...AS SUBTLE SHORTWAVE ENERGY ROUNDS THE EASTERN PERIPHERY OF A LARGE UPPER LEVEL HIGH. THE LATEST HRRR AND THE 12Z HIGH-RES WINDOWS ARE IN REALLY GOOD AGREEMENT ON THE TRENDS...SO I THINK THE POP GRIDS ARE ON TRACK...SINCE THEY WERE BLENDED WITH THOSE CAM POPS EARLIER. AS FOR SEVERE THREAT...WHILE THE STORMS HAVE BEEN GETTING FAIRLY TALL...THE FREEZING LEVEL ABOVE 15 KFT...AND LOW-MOD DCAPE OF 600-800 J/KG IS KEEPING THE MICROBURST THREAT IN CHECK. THERE IS ALSO A HEAVY RAIN THREAT...AS PWATS ARE 1.8-2.0" ACRS THE PIEDMONT...WITH SLOW STORM MOTIONS. TONIGHT...WEAK LOW PRES OVER SOUTHERN GA...AND HIGH PRES TO THE NORTH OF THE AREA WILL KEEP A LIGHT S/SE FLOW ACRS THE CWFA. THIS MAY BE ENUF TO ALLOW FOR LINGERING SHRA AND A FEW EMBEDDED TSTMS WELL PAST SUNSET. I HAVE POPS ON A SLOW DIMINISHING TREND FOR THE TONIGHT PERIOD...TO SLGT CHC BY DAYBREAK WED. LOWS IN THE MID-UPR 60S IN THE MTNS AND LWR-MID 70S PIEDMONT. ON WEDNESDAY...THE SYNOPTIC PATTERN WILL NOT CHANGE MUCH FROM TODAY...WITH 500 MB HIGH PRES CONTINUING TO NOSE N AND E INTO THE AREA FROM THE SOUTHERN PLAINS. HOWEVER...THE OP MODELS ALL RESOLVE ANOTHER VORT MAX DRIFTING SOUTH AROUND THE RIDGE ACRS THE OHIO VALLEY. THIS MAY HELP TRIGGER CONVECTION. THE LLVLS WILL BE SIMILAR...WITH ELEVATED DEWPTS IN THE 70S ACRS THE PIEDMONT. CAPE SHUD BE BACK ABOVE 1500 J/KG OR SO WITH VERY WEAK SHEAR. THE CAMS THAT GO OUT THRU TOMORROW SHOW SIMILAR CONVECTIVE TRENDS AS TODAY. SO WILL GO WITH HIGH-END CHC TO LIKELY POPS. SEVERE THREAT WILL REMAIN LOW WITH MOIST MID LVLS. A SMALL EXCESSIVE RAIN THREAT WILL CONTINUE. HIGHS AROUND PERSISTENCE IN THE 80S MTNS AND LWR-MID 90S PIEDMONT. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... AS OF 140 PM TUESDAY...RETROGRESSION OF THE SUBTROPICAL HIGH INTO THE SOUTHERN ROCKIES/HIGH PLAINS WILL OCCUR THROUGHOUT THE SHORT TERM PERIOD...AS A SERIES OF SHORT WAVES CARVE OUT A LONG WAVE TROUGH ACROSS MUCH OF EASTERN NORTH AMERICA BY THE END OF THE PERIOD. THIS WILL INTRODUCE A (RATHER WEAK) FRONTAL BOUNDARY INTO OUR AREA BY THURSDAY. MEANWHILE...SLIGHT COOLING OF THE MID-LEVEL TEMPS AND CONTINUED HIGH DEWPOINT TEMPERATURES...ALONG WITH THE APPEARANCE OF THE BOUNDARY SHOULD SUPPORT CONTINUED GOOD CHANCES OF CONVECTION THURSDAY AFTERNOON...WITH PERHAPS A BETTER CHANCE FOR A FEW PULSE-SEVERE STORMS WITHIN A MORE UNSTABLE ENVIRONMENT. A DEVELOPING CONSENSUS IN SHORT TERM MODEL GUIDANCE INDICATES THE UPPER TROUGH AXIS WILL BE EAST OF THE FORECAST AREA BY FRI MORNING...TAKING THE FRONTAL BOUNDARY ALONG WITH IT. ALTHOUGH THICKNESS VALUES WILL NOT SUPPORT AN APPRECIABLE COOL DOWN (REALLY ONLY TAKING MAXES BACK TO NEAR-NORMAL LEVELS)...THERE WILL BE A NOTICEABLE CHANGE IN RELATIVE HUMIDITY ACROSS MUCH OF THE AREA FRI AFTERNOON...AS DEWPOINTS COULD MIX OUT INTO THE 50S. THE RESULT WILL BE SMALL (AT BEST) CHANCES FOR CONVECTION FRI AFTERNOON. ALTHOUGH SMALL POPS WILL BE ADVERTISED...MAINLY HIGHLIGHTING SOUTHERN AREAS NEARER THE BOUNDARY...EVEN THESE MAY PROVE TO BE ON THE HIGH SIDE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 210 PM TUESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SATURDAY WITH A BROAD UPPER TROF CENTERED OVER ONTARIO AND QUEBEC AND VERY BROAD UPPER RIDGING IN PLACE OVER THE WESTERN CONUS. THIS GENERAL PATTERN IS EXPECTED TO REMAIN IN PLACE THROUGH THE PERIOD WITH SOME DEAMPLIFICATION OF THE UPPER TROF POSSIBLE TOWARDS THE END OF THE PERIOD. AT THE SFC...RIDGING WILL SPREAD BACK OVER THE CWFA FROM THE NW BY THE START OF THE PERIOD AND LINGER INTO EARLY NEXT WEEK...GRADUALLY GETTING WEAKER. THE ECMWF STILL TRIES TO SPIN UP SOME SORT OF SFC LOW TO OUR SOUTH BY THE END OF THE PERIOD...HOWEVER THE GFS APPEARS LESS BULLISH ON LOW DEVELOPMENT NOW THAN IT HAS OVER THE PAST COUPLE OF DAYS. ALSO OF NOTE...THE LONG RANGE MODEL GUIDANCE IS NOW KEEPING THE PLUME OF DEEPER LYR MOISTURE FARTHER SOUTH AND EAST COMPARED TO PREVIOUS GUIDANCE. THIS WILL ALLOW FOR LOWER OVERALL POPS FOR MOST OF THE PERIOD. AS FOR THE SENSIBLE FCST...WE CAN EXPECT MOSTLY DIURNAL CHANCES FOR SCT CONVECTION EACH DAY/EVENING WITH THE BEST CHANCES OVER THE SE ZONES. TEMPS WILL START OUT RIGHT AROUND NORMAL AND REMAIN NEAR NORMAL THROUGH THE PERIOD. && .AVIATION /23Z TUESDAY THROUGH SUNDAY/... AT KCLT...CONVECTION AND ASSOCIATED RESTRICTIONS WILL REMAIN POSSIBLE THIS EVENING. WITH RAIN HAVING ALREADY OCCURRED...AND MORE POSSIBLE...DAYBREAK MVFR FOG SEEMS LIKELY. MODEL TIME HEIGHTS SUPPORT A CIG AT AROUND 6000 FT FOR MUCH OF THE FORECAST...BUT SHOW SUBSTANTIAL MOISTURE MUCH LOWER...AND DAYBREAK FOG MAY BE ACCOMPANIED BY AN MVFR CIG...AND PERHAPS EVEN LOWER. ANOTHER ROUND OF CONVECTION IS EXPECTED WEDNESDAY AFTERNOON AS THE PATTERN CHANGES LITTLE. LIGHT WINDS WILL GENERALLY FAVOR THE S. ELSEWHERE...CONVECTION AND ASSOCIATED RESTRICTIONS CANNOT BE RULED OUT THIS EVENING...ALTHOUGH THE BEST COVERAGE OS EAST OF THE FOOTHILLS. DAYBREAK FOG IS LIKELY...AS MANY SITES HAD RAIN OR MAY RECEIVE SOME THIS EVENING...AND GUIDANCE IS LEANING IN THAT DIRECTION. THE WORST RESTRICTIONS WOULD BE AT KAVL AND KHKY. MODEL TIME HEIGHTS FAVOR LOW VFR CIGS AT AROUND 4500 TO 6000 FEET...BUT ENOUGH LOW LEVEL MOISTURE IS PRESENT TO ALLOW FOR DAYBREAK MVFR CIGS WHERE FOG OCCURS...AND POSSIBLE EVEN LOWER CIGS. YET ANOTHER AROUND OF CONVECTION IS EXPECTED WEDNESDAY AFTERNOON IN A PERSISTENT UPPER LEVEL PATTERN. LIGHT WINDS WILL FAVOR THE S. OUTLOOK...AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE ATLANTIC STATES LATE IN THE WEEK...WITH THE LIKELY PASSAGE OF A COLD FRONT ON FRIDAY. THE POTENTIAL FOR CONVECTION WILL INCREASE THROUGH FRIDAY...THEN DECREASE BEHIND THE FRONT ON SATURDAY. CONFIDENCE TABLE... 23-05Z 05-11Z 11-17Z 17-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 83% HIGH 83% HIGH 100% KHKY HIGH 100% HIGH 83% MED 78% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JPT NEAR TERM...ARK/JAT SHORT TERM...JDL LONG TERM...JPT AVIATION...JAT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
152 PM EDT MON JUL 27 2015 .SYNOPSIS... HIGH PRESSURE WILL PERSIST OVER THE REGION THROUGH MID WEEK...WITH CONTINUED WARM TEMPERATURES. A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON THURSDAY AND SETTLE SOUTHWARD THROUGH THE REGION ON FRIDAY. THE FRONT WILL LIKELY REMAIN STALLED JUST SOUTH OF THE AREA THROUGH THE WEEKEND...WITH COOLER TEMPERATURES EXPECTED. && .NEAR TERM /THROUGH TONIGHT/... AS OF 145 PM...CONVECTION IS FIRING A LITTLE MORE READILY THAN CURRENT FCST TRENDS...AS A MID LVL SHORTWAVE APPROACHES THE SOUTHERN APPALACHAINS. CAPE IS STILL PRETTY LIMITED...WITH SPC MESO ANALYSIS PAGE SHOWING GENERALLY 500-1000 J/KG OF SBCAPE. CAPE IS AT A MINIMUM ACRS THE PIEDMONT...WHERE DEWPTS HAVE MIXED OUT TO THE MID 60S. THE HRRR IS STILL PRETTY BULLISH ON CONVECTION THIS AFTN AND EVENING ACRS THE ENTIRE AREA. I WILL TAKE ANOTHER LOOK AT GRIDS FOR NEXT UPDATE...BUT HAVE LEFT POPS AS IS FOR NOW. AS OF 1030 AM...EMBEDDED SHORTWAVES CAN BE SEEN ROUNDING THE NORTHERN AND EASTERN PERIPHERY OF A LARGE UPPER LEVEL ANTICYCLONE CENTERED OVER THE SOUTHERN PLAINS. MOST OF THIS ENERGY LOOKS TO REMAIN NORTH OF THE AREA. AT THE SFC...CONDITIONS LOOK SIMILAR TO YESTERDAY...WITH WEAK AXIS OF HIGH PRES STRETCHING ACRS THE SOUTHEAST STATES. THE LATEST GUIDANCE GENERALLY AGREES ON DEWPTS MIXING OUT ACRS THE PIEDMONT...INTO THE LWR-MID 60S. THIS COUPLED WITH WARM MID LVL TEMPS SHUD LIMIT CAPE TO GENERALLY LESS THAN 1000 J/KG. IN THE MTNS...CAPE IS PROGGED TO BE A LITTLE HIGHER. DESPITE THE WEAK BUOYANCY AND SHEAR...THE MAJORITY OF THE HIGH RES MODELS AS WELL AS THE NAM AND RAP SHOW FAIRLY STOUT COVERAGE OF CONVECTION THIS AFTN...ROLLING OFF THE BLUE RIDGE INTO THE PIEDMONT. THE GFS KEEPS THE BULK OF THE CONVECTION IN THE HIGH TERRAIN AND ADJACENT FOOTHILLS...LIKE THE LAST COUPLE DAYS. BASED ON THE CURRENT DEWPT TRENDS AND THE 12Z GSO/FFC SOUNDINGS...I THINK THE GFS IS MORE REALISTIC...AND THAT LINES UP WITH THE CURRENT FCST...WHICH IS CHC POPS ACROSS THE HIGH ELEVATIONS AND THE I-40 CORRIDOR OF THE NC FOOTHILLS AND PIEDMONT. THE REST OF THE FCST IS ON TRACK AS WELL. HIGH TEMPERATURES ARE FORECAST TO PEAK AROUND 1 DEGREE COOLER THAN YESTERDAY. TONIGHT...THE VORT SHOULD SLIDE SE OF THE FA...AS H5 HEIGHTS REMAIN ABOVE 590 DM. FORECAST SOUNDINGS INDICATE THAT CONDITIONS SHOULD GRADUALLY STABILIZE AFTER SUNSET. I WILL INDICATE A SLOW DECREASE IN POPS OVERNIGHT...REMAINING SCHC ACROSS THE NRN NC MTNS AND FOOTHILLS THROUGH SUNRISE TUESDAY. LOW TEMPERATURES ARE FORECAST TO RANGE FROM THE U60S WITHIN THE MTN VALLEYS TO LOW 70S EAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 245 AM EDT MONDAY...A BROAD UPPER RIDGE WILL BE IN PLACE ACROSS THE CENTRAL AND EASTERN CONUS TUESDAY THROUGH WEDNESDAY. WINDS WILL BE LIGHT UNDER THE RIDGE...BUT WITH WEAK LOW LEVEL CONVERGENCE DEVELOPING EACH DAY ALONG THE ERN SLOPES OF THE SRN APPALACHIANS. DESPITE THE RIDGING ALOFT...THE NAM GENERATES CONSIDERABLE INSTABILITY BOTH TUE AND WED AFTERNOONS...ESPECIALLY OVER THE MTNS...WHILE THE GFS PROFILES ARE MORE RESERVED. A BLENDED APPROACH SUGGESTS SCATTERED CONVECTION FOCUSING PRIMARILY ON THE MTNS WITH SOME LATE DAY BLEEDOVER INTO THE ADJACENT FOOTHILLS AND POSSIBLY OUT ACROSS THE INTERSTATE 40 CORRIDOR. MAXES SHOULD BE ABOUT A CATEGORY ABOVE CLIMO...WITH MILD MINS SOME TWO CATEGORIES ABOVE CLIMO. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 245 AM EDT MONDAY...HEIGHTS WILL FALL THURSDAY THROUGH FRIDAY AS THE UPPER RIDGE RETROGRADES TO THE DESERT SOUTHWEST. THIS WILL PERMIT A COLD FRONT TO PUSH SOUTHEAST INTO THE APPALACHIANS THURSDAY EVENING AND SETTLE ACROSS THE SOUTHERN HALF OF THE AREA THROUGH FRIDAY. INSTABILITY MAY POOL ALONG AND AHEAD OF THE APPROACHING COLD FRONT ON THURSDAY...WITH THE BEST CHANCE OF STRONG TO SEVERE THUNDERSTORMS THURSDAY AFTERNOON AND EVENING. AFTER A NIGHTTIME LULL IN CONVECTION...THE BEST COVERAGE ON FRIDAY SHOULD BE ALONG THE SRN TIER CLOSER TO THE BOUNDARY. TROUGHINESS WILL DEVELOP OVER THE EAST AS A DEEP VORTEX SETS UP OVER ONTARIO AND QUEBEC THROUGH THE WEEKEND. AT LOW LEVELS...WEAK SOUTHEAST RETURN FLOW MAY DEVELOP AS THE BOUNDARY LIKELY REMAINS STALLED JUST SOUTH OF THE REGION. A FAIRLY SHARP POP GRADIENT WILL BE NEEDED WITH MUCH BETTER VALUES ACROSS THE SRN TIER SATURDAY AND SUNDAY. COOLER TEMPERATURES ARE EXPECTED...WITH HIGHS IN THE 80S BOTH DAYS AND 70S IN THE HIGH MOUNTAIN VALLEYS. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AT KCLT...GENERALLY VFR CONDITIONS EXPECTED THROUGH THE 18Z TAF PERIOD. CONVECTION IS FIRING ALONG THE BLUE RIDGE AT THE TIME OF THE 18Z TAF ISSUANCE. THE STEERING FLOW WILL TAKE THE SHRA/TSRA TO THE SE TOWARD THE TERMINAL. HOWEVER...THERE IS WEAK INSTABILITY ACRS THE PIEDMONT TODAY. SO MOST OF THE ACTIVITY WILL LIKELY DISSIPATE BEFORE REACHING KCLT. WITH THAT SAID...WILL HAVE A TEMPO FROM 21-24Z FOR TS. THE MOST LIKELY IMPACT WILL BE OUTFLOW THAT WILL COME OUT OF THE NW OR N. SOME OF THE GUIDANCE KEEPS A N TO NE WIND THRU THE EVENING...WHILE OTHER GUIDANCE PREVAILS SE. I THINK THERE WILL BE A PERIOD OF LIGHT NE...BUT THEN SHUD FAVOR SE OVERNIGHT. EITHER WAY...SHUD BE UNDER 5 KTS. OTHERWISE...EXPECT A FAIR AMOUNT OF DEBRIS MID/HIGH CLOUDS...WHICH MAY LIMIT FOG POTENTIAL. UNLESS RAIN IS MORE WIDESPREAD THAN EXPECTED...I THINK IT WILL REMAIN VFR. ON TUESDAY...GUIDANCE IN GOOD AGREEMENT ON BETTER COVERAGE OF CONVECTION STARTING AROUND MIDDAY. WILL LIKELY NEED A PROB30 WITH THE 00Z TAF FOR TOMORROW AFTN. ELSEWHERE...SO FAR CONVECTION IS FIRING ACROSS THE HIGH TERRAIN...AS EXPECTED. INSTABILITY REMAINS WEAK EAST OF THE MTNS...SO EXPECT MOST OF THE ACTIVITY TO REMAIN CONFINED TO THE MTNS. WILL PLACE KAVL AND KHKY WITH VCTS FOR THIS AFTN. THE UPSTATE SITES WILL STRUGGLE TO SEE CONVECTION TOO CLOSE...SO NO MENTION. WINDS WILL BE LIGHT AND CLOUDS GENERALLY 5000 FT OR HIGHER THRU TONIGHT. THEN ON TUESDAY...INCREASED LLVL MOISTURE WILL ALLOW FOR QUICK CUMULUS DEVELOPMENT BELOW 5000 FT. SHRA/TSRA COVERAGE WILL INCREASE TOWARD END OF 18Z TAF PERIOD. WILL MENTION PROB30 AT KAVL...WHERE CONVECTION WILL DEVELOP EARLIEST. FOG POTENTIAL LOOKS LIMITED TO KAVL AND KHKY...WHERE THEY ARE EXPECTED TO RECEIVE SOME RAINFALL TODAY. OUTLOOK...DECENT COVERAGE OF AFTN/EVE SHRA/TSRA EXPECTED EACH DAY THRU THE END OF THIS WEEK...AS MOIST AIR MASS REMAINS IN PLACE. CONFIDENCE TABLE... 18-24Z 00-06Z 06-12Z 12-18Z KCLT HIGH 100% HIGH 100% HIGH 93% HIGH 92% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 94% KAVL HIGH 100% HIGH 100% HIGH 83% HIGH 80% KHKY HIGH 100% HIGH 100% MED 79% HIGH 91% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 98% KAND HIGH 100% HIGH 100% HIGH 97% HIGH 94% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...HG NEAR TERM...ARK/NED SHORT TERM...HG LONG TERM...HG AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1039 AM EDT MON JUL 27 2015 .SYNOPSIS... HIGH PRESSURE WILL PERSIST OVER THE REGION THROUGH MID WEEK...WITH CONTINUED WARM TEMPERATURES. A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON THURSDAY AND SETTLE SOUTHWARD THROUGH THE REGION ON FRIDAY. THE FRONT WILL LIKELY REMAIN STALLED JUST SOUTH OF THE AREA THROUGH THE WEEKEND...WITH COOLER TEMPERATURES EXPECTED. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM...EMBEDDED SHORTWAVES CAN BE SEEN ROUNDING THE NORTHERN AND EASTERN PERIPHERY OF A LARGE UPPER LEVEL ANTICYCLONE CENTERED OVER THE SOUTHERN PLAINS. MOST OF THIS ENERGY LOOKS TO REMAIN NORTH OF THE AREA. AT THE SFC...CONDITIONS LOOK SIMILAR TO YESTERDAY...WITH WEAK AXIS OF HIGH PRES STRETCHING ACRS THE SOUTHEAST STATES. THE LATEST GUIDANCE GENERALLY AGREES ON DEWPTS MIXING OUT ACRS THE PIEDMONT...INTO THE LWR-MID 60S. THIS COUPLED WITH WARM MID LVL TEMPS SHUD LIMIT CAPE TO GENERALLY LESS THAN 1000 J/KG. IN THE MTNS...CAPE IS PROGGED TO BE A LITTLE HIGHER. DESPITE THE WEAK BUOYANCY AND SHEAR...THE MAJORITY OF THE HIGH RES MODELS AS WELL AS THE NAM AND RAP SHOW FAIRLY STOUT COVERAGE OF CONVECTION THIS AFTN...ROLLING OFF THE BLUE RIDGE INTO THE PIEDMONT. THE GFS KEEPS THE BULK OF THE CONVECTION IN THE HIGH TERRAIN AND ADJACENT FOOTHILLS...LIKE THE LAST COUPLE DAYS. BASED ON THE CURRENT DEWPT TRENDS AND THE 12Z GSO/FFC SOUNDINGS...I THINK THE GFS IS MORE REALISTIC...AND THAT LINES UP WITH THE CURRENT FCST...WHICH IS CHC POPS ACROSS THE HIGH ELEVATIONS AND THE I-40 CORRIDOR OF THE NC FOOTHILLS AND PIEDMONT. THE REST OF THE FCST IS ON TRACK AS WELL. HIGH TEMPERATURES ARE FORECAST TO PEAK AROUND 1 DEGREE COOLER THAN YESTERDAY. TONIGHT...THE VORT SHOULD SLIDE SE OF THE FA...AS H5 HEIGHTS REMAIN ABOVE 590 DM. FORECAST SOUNDINGS INDICATE THAT CONDITIONS SHOULD GRADUALLY STABILIZE AFTER SUNSET. I WILL INDICATE A SLOW DECREASE IN POPS OVERNIGHT...REMAINING SCHC ACROSS THE NRN NC MTNS AND FOOTHILLS THROUGH SUNRISE TUESDAY. LOW TEMPERATURES ARE FORECAST TO RANGE FROM THE U60S WITHIN THE MTN VALLEYS TO LOW 70S EAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 245 AM EDT MONDAY...A BROAD UPPER RIDGE WILL BE IN PLACE ACROSS THE CENTRAL AND EASTERN CONUS TUESDAY THROUGH WEDNESDAY. WINDS WILL BE LIGHT UNDER THE RIDGE...BUT WITH WEAK LOW LEVEL CONVERGENCE DEVELOPING EACH DAY ALONG THE ERN SLOPES OF THE SRN APPALACHIANS. DESPITE THE RIDGING ALOFT...THE NAM GENERATES CONSIDERABLE INSTABILITY BOTH TUE AND WED AFTERNOONS...ESPECIALLY OVER THE MTNS...WHILE THE GFS PROFILES ARE MORE RESERVED. A BLENDED APPROACH SUGGESTS SCATTERED CONVECTION FOCUSING PRIMARILY ON THE MTNS WITH SOME LATE DAY BLEEDOVER INTO THE ADJACENT FOOTHILLS AND POSSIBLY OUT ACROSS THE INTERSTATE 40 CORRIDOR. MAXES SHOULD BE ABOUT A CATEGORY ABOVE CLIMO...WITH MILD MINS SOME TWO CATEGORIES ABOVE CLIMO. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 245 AM EDT MONDAY...HEIGHTS WILL FALL THURSDAY THROUGH FRIDAY AS THE UPPER RIDGE RETROGRADES TO THE DESERT SOUTHWEST. THIS WILL PERMIT A COLD FRONT TO PUSH SOUTHEAST INTO THE APPALACHIANS THURSDAY EVENING AND SETTLE ACROSS THE SOUTHERN HALF OF THE AREA THROUGH FRIDAY. INSTABILITY MAY POOL ALONG AND AHEAD OF THE APPROACHING COLD FRONT ON THURSDAY...WITH THE BEST CHANCE OF STRONG TO SEVERE THUNDERSTORMS THURSDAY AFTERNOON AND EVENING. AFTER A NIGHTTIME LULL IN CONVECTION...THE BEST COVERAGE ON FRIDAY SHOULD BE ALONG THE SRN TIER CLOSER TO THE BOUNDARY. TROUGHINESS WILL DEVELOP OVER THE EAST AS A DEEP VORTEX SETS UP OVER ONTARIO AND QUEBEC THROUGH THE WEEKEND. AT LOW LEVELS...WEAK SOUTHEAST RETURN FLOW MAY DEVELOP AS THE BOUNDARY LIKELY REMAINS STALLED JUST SOUTH OF THE REGION. A FAIRLY SHARP POP GRADIENT WILL BE NEEDED WITH MUCH BETTER VALUES ACROSS THE SRN TIER SATURDAY AND SUNDAY. COOLER TEMPERATURES ARE EXPECTED...WITH HIGHS IN THE 80S BOTH DAYS AND 70S IN THE HIGH MOUNTAIN VALLEYS. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... AT KCLT...VFR CONDITIONS EXPECTED THROUGH THE 12Z TAF PERIOD. LIGHT SOUTH WINDS SHOULD DEVELOP WITH MIXING THIS MORNING...THEN STRENGTHENING TO 6 KTS DURING THE HEAT OF THE AFTERNOON. INSTABILITY APPEARS LIMITED TO LESS THAN 500 J/KG THIS AFTERNOON. HOWEVER...CAMS INDICATE THAT A TSRA CLUSTER MAY DEVELOP NEAR KGSO LATE THIS AFTERNOON...THEN SLIDE SE THROUGH EARLY THIS EVENING. COVERAGE OF ANY CONVECTION SHOULD REMAIN EAST OF KCLT...SO NO MENTION WILL BE INCLUDED IN THE TAF. LATEST MOS AND FORECAST SOUNDINGS INDICATE THAT DEPRESSIONS MAY CLOSE TO 3 TO 4 DEGREES BY SUNRISE TUESDAY...TOO WIDE TO MENTION FOG. ELSEWHERE...WIDE DEWPOINT DEPRESSION ACROSS THE WESTERN CAROLINAS WILL LIMIT FOG DEVELOPMENT THIS MORNING. MIXING TO 5 TO 6KFT THIS AFTERNOON SHOULD RESULT IN DEWPOINTS FALLING IN THE LOW TO MID 60S. INSTABILITY ACROSS THE REGION SHOULD REMAIN WEAK...WITH THE GREATEST VALUES OVER THE MTNS. I WILL GIVE KAVL AND KHKY A MID TO LATE AFTERNOON PROB30...ELSEWHERE TERMINALS APPEAR DRY. WINDS SHOULD FAVOR A LIGHT SOUTH WIND DURING THE DAYLIGHT HOURS...KAVL NNW. LATEST OBS AND MOS SHOW THE CLOSEST DEPRESSIONS WITHIN THE MTN VALLEYS AND AREAS OF AFTERNOON RAINFALL. I WILL INDICATE 4 SM BR FOR KAVL AND KHKY AFTER 5Z. OUTLOOK...A MID LEVEL RIDGE WILL REMAIN ACROSS THE WESTERN CAROLINAS THROUGH MID WEEK. A LONGWAVE TROUGH WILL AMPLIFY ACROSS THE ATLANTIC STATE LATE IN THE WEEK...WITH THE LIKELY PASSAGE OF A COLD FRONT ON FRIDAY. THE POTENTIAL FOR CONVECTION WILL INCREASE EACH DAY THIS WEEK. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 88% HIGH 100% HIGH 95% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 95% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...HG NEAR TERM...ARK/NED SHORT TERM...HG LONG TERM...HG AVIATION...NED
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
906 PM CDT TUE JUL 28 2015 .UPDATE... BEST INSTABILITY CONTINUING TO REMAIN ACROSS LOCATIONS APPROACHING THE TN RIVER VALLEY REGION. ALTHOUGH CONVECTION IS WEAKENING... WITH A BROAD AREA OF SHWRS...WITH SOME EMBEDDED TSTMS...REACHING AS FAR E AS THE I-65 CORRIDOR AROUND 02Z...AND THE LATEST HRRR MODEL INITIALIZING THIS OVERALL WX PATTERN BETTER...WILL GO AHEAD WITH INCREASING SHWR/TSTM CHANCES ACROSS THESE AREAS THRU AT LEAST MIDNIGHT...WITH NUMEROUS SHWRS/TSTMS POSSIBLE AS ONE APPROACHES THE TN RIVER VALLEY REGION. BELIEVE THRU THE FIRST PART OF THE EARLY MORNING HRS THAT AT LEAST SCT SHWRS...WITH SOME ISO TSTMS...AROUND UPPER LEVEL RIDGE PERIPHERY...WILL BE POSSIBLE... AND THUS WILL MENTION ALSO. WHILE MAKING THESE CHANGES...TWEAKED HRLY TEMP...DEWPOINT...SKY CONDITION...AND WIND SPEED/DIRECTION GRIDS. && .PREV DISCUSSION.../ISSUED 750 PM CDT TUE JUL 28 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE MENTION OF LATE AFTERNOON ZONE GROUPING IN ZONE FORECAST PRODUCT AND ALL REFERENCES TO HEAT ADVISORY THAT EXPIRED AT 7 PM THIS EVENING. WILL ALSO UPDATE THE HAZARDOUS WEATHER OUTLOOK PRODUCT TO DO THE SAME. PER REGIONAL RADAR TRENDS...WITH SHWRS/TSTMS MOVING IN FROM THE NW INTO LOCATIONS N OF I-40 AND W OF 1-65...AROUND PERIPHERY OF UPPER LEVEL RIDGING DYNAMICS...WILL KEEP CHANCE POPS ACROSS THIS REGION THRU THE MID EVENING HRS...BUT WITH DIURNAL INFLUENCES GRADUALLY WEAKENING...DUE EXPECT AN OVERALL TREND OF WEAKENING SHWRS/TSTMS THRU THE MID EVENING HRS ALONG WITH A DECREASING TREND IN AREAL COVERAGE. THIS REASONING SUPPORTED BY CONSENSUS OF SHORT RANGE MODEL SOLUTIONS. WILL KEEP A SLIGHT CHANCE OF SHWRS/TSTMS ACROSS THE REST OF THE MID STATE THRU THE EVENING HRS. EVEN THOUGH THERE IS SOME INDICATION IN SHORT RANGE MODELS FOR A PREFERENCE FOR SHWR/TSTM ACTIVITY ACROSS WRN PORTIONS OF THE MID STATE AFTER MIDNIGHT...ONLY EXPECTING ISO SHWRS/TSTMS AT BEST...AND WILL THUS ADDRESS ALL AREAS ACROSS THE MID STATE EXPERIENCING A SLIGHT CHANCE OF SHWRS/TSTMS AFTER MIDNIGHT. ALSO TWEAKED HRLY TEMP...DEWPOINT...SKY CONDITION...AND WIND SPEED/DIRECTION GRIDS. CURRENT TEMPS TRENDS SEEM IN LINE WITH FORECASTED LOW VALUES EXPECTED OVERNIGHT AND THUS NO CHANGES NEEDED. PREV DISCUSSION.../ISSUED 615 PM CDT TUE JUL 28 2015/ AVIATION 00Z DISCUSSION... IMPULSE MOVING SOUTHWARD THROUGH THE MID STATE THIS EVENING. NVA SHOULD MOVE IN AFT 03Z AND END THE OVERNIGHT CONVECTION. HRRR CONCURS WITH RAIN FREE CONDITIONS BY 5Z. WILL OPT TO BE A LITTLE MORE BULLISH WITH THE FOG POTENTIAL AND LOWER THE TEMPORARY VSBY REDUCTIONS. MUCH OF THE AREA IS RAIN COOLED AND DEWPOINT SPREADS ARE RATHER LOW. UPPER HIGH MAY BE IN CLOSER PROXIMITY FOR TOMORROW. HOWEVER...CAPE TO CAP RATIOS WILL BECOME FAVORABLE ONCE AGAIN IN THE AFT. WILL INCLUDE VCNTY/CONVECTION IN TAFS AFT 18Z. PREV DISCUSSION.../ISSUED 509 PM CDT TUE JUL 28 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO ADD A LATE AFTERNOON ZONE GROUPING TO THE ZONE FORECAST PRODUCT TO EMPHASIZE SCT SHWR/TSTM CONVECTION ACROSS MID STATE. ALSO ADJUSTED HRLY TEMP...DEWPOINT... WIND DIRECTION/SPEED...AND SKY CONDITION GRIDS. PREV DISCUSSION.../ISSUED 236 PM CDT TUE JUL 28 2015/ DISCUSSION... UPPER RIDGE HAS A STRONGHOLD ON MUCH OF THE AREA WITH HIGH HEAT INDICIES PROMPTING A HEAT ADVISORY FOR A GOOD PART OF THE MID STATE UNTIL 7 PM CDT THIS EVENING. CONVECTION HAS FIRED IN THE AFTERNOON HEAT MAINLY ACROSS EASTERN AREAS AND ALONG THE PLATEAU WITH MORE CONVECTION DROPPING SOUTH BOUND FROM KENTUCKY. LOOKS LIKE A VORTICITY MAX (SHORT WAVE) WORKING DOWN FRONT SIDE OF UPPER RIDGE. VORT MAX CURRENTLY SHOWING UP IN LATEST RUC13 RUN NOSING JUST SOUTH OF OHIO RIVER SOUTH OF LOUISVILLE...HEADED THIS WAY. SHORT WAVE SHOULD ENHANCE CONVECTION OVER SOUTH CENTRAL KENTUCKY THAT WILL WORK DOWN INTO MIDDLE TENNESSEE REMAINDER OF THE AFTERNOON AND INTO THE EVENING. MODELS KEEP SOME CONVECTION AROUND AFTER MIDNIGHT WITH WESTERN AREAS OF THE MID STATE FAVORED. ANOTHER HOT DAY WEDNESDAY WITH AN INCREASED CHANCE OF RAIN AS FRONT APPROACHES FROM THE NORTHWEST. SHOWER AND THUNDERSTORMS WILL RAMP UP WEDNESDAY EVENING AND OVERNIGHT AS FRONT WORKS INTO THE MID STATE. SHOWER AND THUNDERSTORM CHANCES CONTINUE SOUTHEAST HALF ON THURSDAY BUT DRY THURSDAY NIGHT AND THROUGH THE UPCOMING WEEKEND. UPPER RIDGE THAT HAS KEPT TEMPS ABOVE NORMAL AND HEAT INDICIES AROUND TRIPLE DIGITS WILL FINALLY RETROGRADE ALLOWING UPPER TROUGH TO DOMINATE FRIDAY THROUGH THE WEEKEND. NEXT CHANCE FOR RAIN LOOKS TO BE ABOUT THE MIDDLE OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 76 94 75 90 / 40 30 40 30 CLARKSVILLE 75 94 72 87 / 60 30 40 10 CROSSVILLE 71 87 72 84 / 20 30 40 50 COLUMBIA 75 93 74 91 / 60 30 40 40 LAWRENCEBURG 75 90 73 90 / 60 30 40 50 WAVERLY 75 95 73 88 / 60 30 40 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
750 PM CDT TUE JUL 28 2015 .UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE MENTION OF LATE AFTERNOON ZONE GROUPING IN ZONE FORECAST PRODUCT AND ALL REFERENCES TO HEAT ADVISORY THAT EXPIRED AT 7 PM THIS EVENING. WILL ALSO UPDATE THE HAZARDOUS WEATHER OUTLOOK PRODUCT TO DO THE SAME. PER REGIONAL RADAR TRENDS...WITH SHWRS/TSTMS MOVING IN FROM THE NW INTO LOCATIONS N OF I-40 AND W OF 1-65...AROUND PERIPHERY OF UPPER LEVEL RIDGING DYNAMICS...WILL KEEP CHANCE POPS ACROSS THIS REGION THRU THE MID EVENING HRS...BUT WITH DIURNAL INFLUENCES GRADUALLY WEAKENING...DUE EXPECT AN OVERALL TREND OF WEAKENING SHWRS/TSTMS THRU THE MID EVENING HRS ALONG WITH A DECREASING TREND IN AREAL COVERAGE. THIS REASONING SUPPORTED BY CONSENSUS OF SHORT RANGE MODEL SOLUTIONS. WILL KEEP A SLIGHT CHANCE OF SHWRS/TSTMS ACROSS THE REST OF THE MID STATE THRU THE EVENING HRS. EVEN THOUGH THERE IS SOME INDICATION IN SHORT RANGE MODELS FOR A PREFERENCE FOR SHWR/TSTM ACTIVITY ACROSS WRN PORTIONS OF THE MID STATE AFTER MIDNIGHT...ONLY EXPECTING ISO SHWRS/TSTMS AT BEST...AND WILL THUS ADDRESS ALL AREAS ACROSS THE MID STATE EXPERIENCING A SLIGHT CHANCE OF SHWRS/TSTMS AFTER MIDNIGHT. ALSO TWEAKED HRLY TEMP...DEWPOINT...SKY CONDITION...AND WIND SPEED/DIRECTION GRIDS. CURRENT TEMPS TRENDS SEEM IN LINE WITH FORECASTED LOW VALUES EXPECTED OVERNIGHT AND THUS NO CHANGES NEEDED. && .PREV DISCUSSION.../ISSUED 615 PM CDT TUE JUL 28 2015/ AVIATION 00Z DISCUSSION... IMPULSE MOVING SOUTHWARD THROUGH THE MID STATE THIS EVENING. NVA SHOULD MOVE IN AFT 03Z AND END THE OVERNIGHT CONVECTION. HRRR CONCURS WITH RAIN FREE CONDITIONS BY 5Z. WILL OPT TO BE A LITTLE MORE BULLISH WITH THE FOG POTENTIAL AND LOWER THE TEMPORARY VSBY REDUCTIONS. MUCH OF THE AREA IS RAIN COOLED AND DEWPOINT SPREADS ARE RATHER LOW. UPPER HIGH MAY BE IN CLOSER PROXIMITY FOR TOMORROW. HOWEVER...CAPE TO CAP RATIOS WILL BECOME FAVORABLE ONCE AGAIN IN THE AFT. WILL INCLUDE VCNTY/CONVECTION IN TAFS AFT 18Z. PREV DISCUSSION.../ISSUED 509 PM CDT TUE JUL 28 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO ADD A LATE AFTERNOON ZONE GROUPING TO THE ZONE FORECAST PRODUCT TO EMPHASIZE SCT SHWR/TSTM CONVECTION ACROSS MID STATE. ALSO ADJUSTED HRLY TEMP...DEWPOINT... WIND DIRECTION/SPEED...AND SKY CONDITION GRIDS. PREV DISCUSSION.../ISSUED 236 PM CDT TUE JUL 28 2015/ DISCUSSION... UPPER RIDGE HAS A STRONGHOLD ON MUCH OF THE AREA WITH HIGH HEAT INDICIES PROMPTING A HEAT ADVISORY FOR A GOOD PART OF THE MID STATE UNTIL 7 PM CDT THIS EVENING. CONVECTION HAS FIRED IN THE AFTERNOON HEAT MAINLY ACROSS EASTERN AREAS AND ALONG THE PLATEAU WITH MORE CONVECTION DROPPING SOUTH BOUND FROM KENTUCKY. LOOKS LIKE A VORTICITY MAX (SHORT WAVE) WORKING DOWN FRONT SIDE OF UPPER RIDGE. VORT MAX CURRENTLY SHOWING UP IN LATEST RUC13 RUN NOSING JUST SOUTH OF OHIO RIVER SOUTH OF LOUISVILLE...HEADED THIS WAY. SHORT WAVE SHOULD ENHANCE CONVECTION OVER SOUTH CENTRAL KENTUCKY THAT WILL WORK DOWN INTO MIDDLE TENNESSEE REMAINDER OF THE AFTERNOON AND INTO THE EVENING. MODELS KEEP SOME CONVECTION AROUND AFTER MIDNIGHT WITH WESTERN AREAS OF THE MID STATE FAVORED. ANOTHER HOT DAY WEDNESDAY WITH AN INCREASED CHANCE OF RAIN AS FRONT APPROACHES FROM THE NORTHWEST. SHOWER AND THUNDERSTORMS WILL RAMP UP WEDNESDAY EVENING AND OVERNIGHT AS FRONT WORKS INTO THE MID STATE. SHOWER AND THUNDERSTORM CHANCES CONTINUE SOUTHEAST HALF ON THURSDAY BUT DRY THURSDAY NIGHT AND THROUGH THE UPCOMING WEEKEND. UPPER RIDGE THAT HAS KEPT TEMPS ABOVE NORMAL AND HEAT INDICIES AROUND TRIPLE DIGITS WILL FINALLY RETROGRADE ALLOWING UPPER TROUGH TO DOMINATE FRIDAY THROUGH THE WEEKEND. NEXT CHANCE FOR RAIN LOOKS TO BE ABOUT THE MIDDLE OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 76 94 75 90 / 20 30 40 30 CLARKSVILLE 75 94 72 87 / 40 30 40 10 CROSSVILLE 71 87 72 84 / 20 30 40 50 COLUMBIA 75 93 74 91 / 20 30 40 40 LAWRENCEBURG 75 90 73 90 / 20 30 40 50 WAVERLY 75 95 73 88 / 40 30 40 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
615 PM CDT TUE JUL 28 2015 .AVIATION 00Z DISCUSSION... IMPULSE MOVING SOUTHWARD THROUGH THE MID STATE THIS EVENING. NVA SHOULD MOVE IN AFT 03Z AND END THE OVERNIGHT CONVECTION. HRRR CONCURS WITH RAIN FREE CONDITIONS BY 5Z. WILL OPT TO BE A LITTLE MORE BULLISH WITH THE FOG POTENTIAL AND LOWER THE TEMPORARY VSBY REDUCTIONS. MUCH OF THE AREA IS RAIN COOLED AND DEWPOINT SPREADS ARE RATHER LOW. UPPER HIGH MAY BE IN CLOSER PROXIMITY FOR TOMORROW. HOWEVER...CAPE TO CAP RATIOS WILL BECOME FAVORABLE ONCE AGAIN IN THE AFT. WILL INCLUDE VCNTY/CONVECTION IN TAFS AFT 18Z. && .PREV DISCUSSION... /ISSUED 509 PM CDT TUE JUL 28 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO ADD A LATE AFTERNOON ZONE GROUPING TO THE ZONE FORECAST PRODUCT TO EMPHASIZE SCT SHWR/TSTM CONVECTION ACROSS MID STATE. ALSO ADJUSTED HRLY TEMP...DEWPOINT... WIND DIRECTION/SPEED...AND SKY CONDITION GRIDS. PREV DISCUSSION.../ISSUED 236 PM CDT TUE JUL 28 2015/ DISCUSSION... UPPER RIDGE HAS A STRONGHOLD ON MUCH OF THE AREA WITH HIGH HEAT INDICIES PROMPTING A HEAT ADVISORY FOR A GOOD PART OF THE MID STATE UNTIL 7 PM CDT THIS EVENING. CONVECTION HAS FIRED IN THE AFTERNOON HEAT MAINLY ACROSS EASTERN AREAS AND ALONG THE PLATEAU WITH MORE CONVECTION DROPPING SOUTH BOUND FROM KENTUCKY. LOOKS LIKE A VORTICITY MAX (SHORT WAVE) WORKING DOWN FRONT SIDE OF UPPER RIDGE. VORT MAX CURRENTLY SHOWING UP IN LATEST RUC13 RUN NOSING JUST SOUTH OF OHIO RIVER SOUTH OF LOUISVILLE...HEADED THIS WAY. SHORT WAVE SHOULD ENHANCE CONVECTION OVER SOUTH CENTRAL KENTUCKY THAT WILL WORK DOWN INTO MIDDLE TENNESSEE REMAINDER OF THE AFTERNOON AND INTO THE EVENING. MODELS KEEP SOME CONVECTION AROUND AFTER MIDNIGHT WITH WESTERN AREAS OF THE MID STATE FAVORED. ANOTHER HOT DAY WEDNESDAY WITH AN INCREASED CHANCE OF RAIN AS FRONT APPROACHES FROM THE NORTHWEST. SHOWER AND THUNDERSTORMS WILL RAMP UP WEDNESDAY EVENING AND OVERNIGHT AS FRONT WORKS INTO THE MID STATE. SHOWER AND THUNDERSTORM CHANCES CONTINUE SOUTHEAST HALF ON THURSDAY BUT DRY THURSDAY NIGHT AND THROUGH THE UPCOMING WEEKEND. UPPER RIDGE THAT HAS KEPT TEMPS ABOVE NORMAL AND HEAT INDICIES AROUND TRIPLE DIGITS WILL FINALLY RETROGRADE ALLOWING UPPER TROUGH TO DOMINATE FRIDAY THROUGH THE WEEKEND. NEXT CHANCE FOR RAIN LOOKS TO BE ABOUT THE MIDDLE OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 76 94 75 90 / 40 30 40 30 CLARKSVILLE 75 94 72 87 / 30 30 40 10 CROSSVILLE 71 87 72 84 / 40 30 40 50 COLUMBIA 75 93 74 91 / 30 30 40 40 LAWRENCEBURG 75 90 73 90 / 30 30 40 50 WAVERLY 75 95 73 88 / 30 30 40 10 && .OHX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR TNZ005>008-023>028- 056>062-075-093>095. && $$ 21
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
257 PM CDT MON JUL 27 2015 .DISCUSSION... CURRENTLY...UPPER LEVEL HIGH PRESSURE CONTINUES ACROSS THE REGION WITH HOT AND HUMID WEATHER ACROSS THE MIDSOUTH. VERY ISOLATED CONVECTION OCCURRING MAINLY ON THE PERIPHERY OF THE MIDSOUTH ATTM. TEMPS ARE IN THE LOWER TO MID 90S WITH HEAT INDEX VALUES AROUND 105 DEGREES ACROSS THE WEST HALF OF THE MIDSOUTH AND 100-105 DEGREES OVER THE EAST HALF. TONIGHT THROUGH TUESDAY NIGHT...A FEW POP UP THUNDERSTORMS ARE POSSIBLE THROUGH EARLY EVENING MAINLY ACROSS THE NORTHERN TIER JUDGING BY RADAR TRENDS AND THE LATEST HRRR. ANOTHER VERY WARM NIGHT WITH LOWS IN THE 70S BY MORNING. A 594 DM UPPER RIDGE WILL CONTINUE TO MOVE EAST ON TUESDAY AND BE CENTERED JUST WEST OF THE MIDSOUTH. LOOKS LIKE MOST OF THE CONVECTIVE ACTIVITY WILL STAY NE OF THE MIDSOUTH ON TUESDAY. HEAT AND HUMIDITY WILL CONTINUE TO BUILD WITH HIGHS IN THE UPPER 90S...WILL EXPAND THE HEAT ADVISORY TO INCLUDE ALL OF THE MID SOUTH BY LATE TUESDAY MORNING. TUESDAY NIGHT WILL BE VERY WARM WITH LOWS IN THE MID 70S TO AROUND 80. WEDNESDAY AND WEDNESDAY NIGHT...THE UPPER RIDGE WILL START TO WEAKEN AS A COLD FRONT APPROACHES FROM THE NW. TEMPS WILL STILL CLIMB INTO THE MID AND UPPER 90S AND DEWPOINTS WILL PROBABLY POOL AHEAD OF THE COLD FRONT. AT THE VERY LEAST HEAT ADVISORIES WILL PROBABLY NEED TO BE EXPANDED AND A EXCESSIVE HEAT WARMING MAY BE NEEDED AS HEAT INDEX VALUES COULD TOP 110 DEGREES. MODELS CONTINUE TO DISPLAY VERY LITTLE QPF WITH THE FRONT AS IT MOVES THROUGH. SLIGHT CHANCE/CHANCE POPS WILL SUFFICE FOR NOW WEDNESDAY THROUGH THURSDAY MORNING. THURSDAY THROUGH MONDAY...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT THURSDAY INTO THE WEEKEND WITH A MUCH DRIER AIRMASS AND COOLER TEMPERATURES. HIGHS WILL DROP BACK TO AROUND 90 THURSDAY AND FRIDAY WITH IN THE UPPER 60S TO AROUND 70. TEMPS WILL START TO CLIMB DURING THE WEEKEND BUT HUMIDITIES WILL REMAIN REASONABLE. SJM && .AVIATION... 18Z TAFS IN GENERAL VFR CONDITIONS WITH EXCEPTION AT MKL DUE TO FOG WITH LIGHT WINDS AND CLEAR SKIES. LEAVING VCTS IN JBR FROM 20Z-02Z FOR POTENTIAL AS SHOWN ON HRRR MODEL. BELLES && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR COAHOMA-DESOTO- LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA- YALOBUSHA. HEAT ADVISORY FROM 11 AM TO 8 PM CDT TUESDAY FOR ALCORN-BENTON MS-CALHOUN-CHICKASAW-ITAWAMBA-LEE MS-MONROE-PONTOTOC- PRENTISS-TIPPAH-TISHOMINGO-UNION. TN...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DYER-FAYETTE-LAKE- LAUDERDALE-SHELBY-TIPTON. HEAT ADVISORY FROM 11 AM TO 8 PM CDT TUESDAY FOR BENTON TN- CARROLL-CHESTER-CROCKETT-DECATUR-GIBSON-HARDEMAN-HARDIN- HAYWOOD-HENDERSON-HENRY-MADISON-MCNAIRY-OBION-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1259 PM CDT MON JUL 27 2015 .UPDATE... UPDATED FOR 18Z TAFS && .PREV DISCUSSION... /ISSUED 1111 AM CDT MON JUL 27 2015/ DISCUSSION... HOT AND HUMID CONDITIONS ACROSS THE MID-SOUTH. TEMPS ALREADY 93F AT KMEM AT 11 AM CDT. HEAT ADVISORY REMAINS IN EFFECT ALONG AND WEST OF A DYERSBURG TN TO OXFORD MS LINE INCLUDING THE MEMPHIS METRO FOR HEAT INDEX VALUES BETWEEN 105 AND 110 DEGREES. THE COMPLEX OF THUNDERSTORMS THAT MOVED ACROSS SRN IL EARLIER THIS MORNING FELL APART AS IT MOVED INTO WRN KY. AN OUTFLOW BOUNDARY ASSOCIATED WITH THAT ACTIVITY DID PUSH SOUTH INTO HENRY COUNTY AND THAT COULD PROVIDE A FOCUS FOR ACTIVITY THIS AFTN. THE HRRR CONTINUES TO SHOW DEVELOPMENT ACROSS THE NORTHERN TIER THIS AFTERNOON SO THE MENTION OF THUNDERSTORMS NORTH OF A JONESBORO TO JACKSON LINE LOOKS GOOD. FORECAST ON TRACK. SJM PREV DISCUSSION... /ISSUED 413 AM CDT MON JUL 27 2015/ EXCESSIVE HEAT WILL INCREASE AND EXPAND OVER THE MIDSOUTH FROM THE WEST THROUGH WEDNESDAY. EARLY THIS MORNING...SOME MIDDLE LEVEL CLOUDS WERE FORMING ACROSS PORTIONS OF THE AREA BUT NO RAIN WAS OCCURRING. TEMPERATURES WERE IN THE 70S EXCEPT FOR A FEW LOWER 80S ALONG AND WEST OF THE MS RIVER. WATCHING A DEVELOPING COMPLEX OF THUNDERSTORMS ACROSS SOUTHERN IL THAT IS MOVING SOUTHEASTWARD. OUTFLOW BOUNDARIES FROM THIS COMPLEX MAY LEAD TO SCATTERED THUNDERSTORMS AFFECTING PORTIONS OF WEST TN ALONG THE TN RIVER INCLUDING PARIS...THUS INCLUDED A CHANCE OF THUNDERSTORMS FOR THIS AREA. THE HRRR AND RAP INDICATE ADDITIONAL THUNDERSTORMS MAY MOVE INTO EXTREME NORTHEAST AR...THE MO BOOTHEEL...AND THE REMAINDER OF THE EXTREME NORTHERN PORTIONS OF WEST TN FROM THE NORTHWEST TODAY...THUS INDICATED SLIGHT CHANCE POPS FOR THIS AREA. ELSEWHERE KEPT POPS BELOW MENTIONABLE LEVELS...ALTHOUGH A STRAY THUNDERSTORM IS POSSIBLE ANYWHERE WITH THE HIGH HEAT AND HUMIDITY. STRONG HIGH PRESSURE ALOFT OVER THE SOUTHERN PLAINS WILL GRADUALLY MOVE EASTWARD BECOMING CENTERED OVER THE OZARKS TUESDAY WITH 500 MB HEIGHTS INCREASING TO 594 DM. A HEAT ADVISORY HAS BEEN POSTED FOR TODAY THROUGH TUESDAY EVENING FOR NORTHEAST AND EAST CENTRAL AR...THE MO BOOTHEEL...PORTIONS OF WEST TN AND NORTHWEST MS. THE ADVISORY WILL LIKELY NEED TO BE EXPANDED TO INCLUDE THE ENTIRE MIDSOUTH BY WEDNESDAY. LATER FORECASTS MAY ALSO NEED TO CONSIDER AN EXCESSIVE HEAT WARNING FOR PORTIONS OF THE REGION WITH HEAT INDEX READINGS POSSIBLY TOPPING 110 DEGREES IN SOME LOCATIONS. SURFACE DEW POINTS WILL PROBABLY POOL AHEAD OF AN APPROACHING COLD FRONT WEDNESDAY LEADING TO GREATER HUMIDITY AND EVEN MORE OPPRESSIVE CONDITIONS. MODELS ARE IN AGREEMENT IN WEAKENING THE UPPER LEVEL RIDGE ACROSS THE MIDSOUTH WEDNESDAY NIGHT. A COLD FRONT IS FORECAST TO MOVE QUICKLY THROUGH THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. MODELS ARE NOT INDICATING MUCH CONVECTION AND MINIMUM RAINFALL WITH THE FRONT. NOT SURE ABOUT THIS CONSIDERING HOW WARM AND HUMID IT WILL BE ADVANCE OF THE FRONT...ALTHOUGH UPPER LEVEL SUPPORT WILL BE NON-EXISTENT. WILL MENTION A THREAT OF A FEW STRONG THUNDERSTORMS AND LOCALLY HEAVY DOWNPOURS IN THE HAZARDOUS WEATHER OUTLOOK WITH THE FRONTAL PASSAGE. THE COLD FRONT IS NOW FORECAST TO PUSH SOUTH OF THE MIDSOUTH THURSDAY MORNING. WELCOME RELIEF FROM THE HEAT AND HUMIDITY WILL OCCUR AS DRIER AND COOLER AIR FOLLOWS THE FRONT PERSISTING INTO THE FIRST HALF OF THE WEEKEND. HIGH PRESSURE ALOFT WILL BEGIN TO BUILD INTO THE AREA SUNDAY WITH INCREASING TEMPERATURES BUT CONTINUED DRY WEATHER. JCL && .AVIATION... 18Z TAFS IN GENERAL VFR CONDITIONS WITH EXCEPTION AT MKL DUE TO FOG WITH LIGHT WINDS AND CLEAR SKIES. LEAVING VCTS IN JBR FROM 20Z-02Z FOR POTENTIAL AS SHOWN ON HRRR MODEL. BELLES && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR COAHOMA-DESOTO- LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA- YALOBUSHA. TN...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DYER-FAYETTE-LAKE- LAUDERDALE-SHELBY-TIPTON. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1111 AM CDT MON JUL 27 2015 .DISCUSSION... HOT AND HUMID CONDITIONS ACROSS THE MID-SOUTH. TEMPS ALREADY 93F AT KMEM AT 11 AM CDT. HEAT ADVISORY REMAINS IN EFFECT ALONG AND WEST OF A DYERSBURG TN TO OXFORD MS LINE INCLUDING THE MEMPHIS METRO FOR HEAT INDEX VALUES BETWEEN 105 AND 110 DEGREES. THE COMPLEX OF THUNDERSTORMS THAT MOVED ACROSS SRN IL EARLIER THIS MORNING FELL APART AS IT MOVED INTO WRN KY. AN OUTFLOW BOUNDARY ASSOCIATED WITH THAT ACTIVITY DID PUSH SOUTH INTO HENRY COUNTY AND THAT COULD PROVIDE A FOCUS FOR ACTIVITY THIS AFTN. THE HRRR CONTINUES TO SHOW DEVELOPMENT ACROSS THE NORTHERN TIER THIS AFTERNOON SO THE MENTION OF THUNDERSTORMS NORTH OF A JONESBORO TO JACKSON LINE LOOKS GOOD. FORECAST ON TRACK. SJM && PREV DISCUSSION... /ISSUED 413 AM CDT MON JUL 27 2015/ EXCESSIVE HEAT WILL INCREASE AND EXPAND OVER THE MIDSOUTH FROM THE WEST THROUGH WEDNESDAY. EARLY THIS MORNING...SOME MIDDLE LEVEL CLOUDS WERE FORMING ACROSS PORTIONS OF THE AREA BUT NO RAIN WAS OCCURRING. TEMPERATURES WERE IN THE 70S EXCEPT FOR A FEW LOWER 80S ALONG AND WEST OF THE MS RIVER. WATCHING A DEVELOPING COMPLEX OF THUNDERSTORMS ACROSS SOUTHERN IL THAT IS MOVING SOUTHEASTWARD. OUTFLOW BOUNDARIES FROM THIS COMPLEX MAY LEAD TO SCATTERED THUNDERSTORMS AFFECTING PORTIONS OF WEST TN ALONG THE TN RIVER INCLUDING PARIS...THUS INCLUDED A CHANCE OF THUNDERSTORMS FOR THIS AREA. THE HRRR AND RAP INDICATE ADDITIONAL THUNDERSTORMS MAY MOVE INTO EXTREME NORTHEAST AR...THE MO BOOTHEEL...AND THE REMAINDER OF THE EXTREME NORTHERN PORTIONS OF WEST TN FROM THE NORTHWEST TODAY...THUS INDICATED SLIGHT CHANCE POPS FOR THIS AREA. ELSEWHERE KEPT POPS BELOW MENTIONABLE LEVELS...ALTHOUGH A STRAY THUNDERSTORM IS POSSIBLE ANYWHERE WITH THE HIGH HEAT AND HUMIDITY. STRONG HIGH PRESSURE ALOFT OVER THE SOUTHERN PLAINS WILL GRADUALLY MOVE EASTWARD BECOMING CENTERED OVER THE OZARKS TUESDAY WITH 500 MB HEIGHTS INCREASING TO 594 DM. A HEAT ADVISORY HAS BEEN POSTED FOR TODAY THROUGH TUESDAY EVENING FOR NORTHEAST AND EAST CENTRAL AR...THE MO BOOTHEEL...PORTIONS OF WEST TN AND NORTHWEST MS. THE ADVISORY WILL LIKELY NEED TO BE EXPANDED TO INCLUDE THE ENTIRE MIDSOUTH BY WEDNESDAY. LATER FORECASTS MAY ALSO NEED TO CONSIDER AN EXCESSIVE HEAT WARNING FOR PORTIONS OF THE REGION WITH HEAT INDEX READINGS POSSIBLY TOPPING 110 DEGREES IN SOME LOCATIONS. SURFACE DEW POINTS WILL PROBABLY POOL AHEAD OF AN APPROACHING COLD FRONT WEDNESDAY LEADING TO GREATER HUMIDITY AND EVEN MORE OPPRESSIVE CONDITIONS. MODELS ARE IN AGREEMENT IN WEAKENING THE UPPER LEVEL RIDGE ACROSS THE MIDSOUTH WEDNESDAY NIGHT. A COLD FRONT IS FORECAST TO MOVE QUICKLY THROUGH THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. MODELS ARE NOT INDICATING MUCH CONVECTION AND MINIMUM RAINFALL WITH THE FRONT. NOT SURE ABOUT THIS CONSIDERING HOW WARM AND HUMID IT WILL BE ADVANCE OF THE FRONT...ALTHOUGH UPPER LEVEL SUPPORT WILL BE NON-EXISTENT. WILL MENTION A THREAT OF A FEW STRONG THUNDERSTORMS AND LOCALLY HEAVY DOWNPOURS IN THE HAZARDOUS WEATHER OUTLOOK WITH THE FRONTAL PASSAGE. THE COLD FRONT IS NOW FORECAST TO PUSH SOUTH OF THE MIDSOUTH THURSDAY MORNING. WELCOME RELIEF FROM THE HEAT AND HUMIDITY WILL OCCUR AS DRIER AND COOLER AIR FOLLOWS THE FRONT PERSISTING INTO THE FIRST HALF OF THE WEEKEND. HIGH PRESSURE ALOFT WILL BEGIN TO BUILD INTO THE AREA SUNDAY WITH INCREASING TEMPERATURES BUT CONTINUED DRY WEATHER. JCL && .AVIATION... 12Z TAF CYCLE VFR CONDITIONS EXPECTED WITH THE EXCEPTION OF MKL THROUGH THE PERIOD. SHALLOW FOG CONTINUES TO PERIODICALLY REDUCE VISBYS BELOW 3SM THIS MORNING BUT THIS SHOULD BURN OFF BY 14Z. DURING THE DAY ON MONDAY...ISOLATED THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON HOURS AT MKL WITH ALL OTHER TERMINALS LIKELY REMAINING DRY. FOG WILL LIKELY DEVELOP AGAIN AT MKL OVERNIGHT WITH SIMILAR REDUCTIONS IN VISBYS EXPECTED. TVT && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR COAHOMA-DESOTO- LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA- YALOBUSHA. TN...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DYER-FAYETTE-LAKE- LAUDERDALE-SHELBY-TIPTON. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1107 AM CDT MON JUL 27 2015 .UPDATE... LATEST RADAR IMAGERY SHOWS EARLIER CONVECTION NEAR PAH HAS DISSIPATED. 12Z OHX SOUNDING SHOWS SUBSTANTIAL MOISTURE BELOW 600 MB...AND EXPECTED WIDELY SCATTERED SHOWERS AND STORMS TO DEVELOP THIS AFTERNOON ON THE PLATEAU WITH ISOLATED ACTIVITY WEST OF THERE PER LATEST HRRR RUNS. ADJUSTED POPS DOWNWARD ACROSS NORTHWEST ZONES AND TWEAKED GRIDS/ZONES BASED ON LATEST OBS. SHAMBURGER && .PREV DISCUSSION... /ISSUED 616 AM CDT MON JUL 27 2015/ AVIATION UPDATE...FOR 12Z TAF`S...BNA/CKV/CSV...DENSE FOG AND LOW STRATUS ARE STARTING OFF AT CKV, AND EXPECT TO GO VFR BY 14Z. CLUSTER OF CONVECTION CURRENTLY AFFECTING EXTREME WRN KY & SRN IL MAY MAKE IT INTO NW MIDDLE TENNESSEE LATER THIS MORNING, SO AM INCLUDING VCTS FOR CKV. ALSO EXPECT SCATTERED CELLS TO DEVELOP ALONG THE PLATEAU THIS AFTERNOON, SO TS A POSSIBILITY AT CSV. ONCE AGAIN EXPECT RADIATION FOG TO DEVELOP BY LATE EVENING AND OVERNIGHT. PREV DISCUSSION... /ISSUED 303 AM CDT MON JUL 27 2015/ DISCUSSION... AAAH...THE NORTHWEST FLOW ALOFT STINGS US AGAIN. THE MCS THAT WAS UPSTREAM OF US THIS TIME YESTERDAY DECIDED IT HAD JUST ENOUGH STEAM TO MAKE IT INTO OUR NORTHWEST COUNTIES BY MID-MORNING BEFORE DYING OUT. WITH THAT THOUGHT IN MIND AND NW FLOW ALOFT STILL OVERHEAD... GOING TO HEED TO THE CLUSTER OF SHOWERS AND THUNDERSTORMS IN SOUTHWEST ILLINOIS AND INCREASE POPS FOR MID-STATE COUNTIES WEST OF INTERSTATE 65 FOR LATER THIS MORNING. NOT REAL CONCERNED ABOUT SEVERE WEATHER BECAUSE OF THE UPPER RIDGING THAT IS TRYING TO PUSH IN FROM THE WEST...BUT SOME OF THESE STORMS COULD BECOME STRONG AT TIMES WITH SMALL HAIL AND/OR GUSTY WINDS. BY LATE AFTERNOON THE FOCUS WILL SHIFT TO THE CUMBERLAND PLATEAU WITH THE BETTER RAIN CHANCES EAST OF I-65. SAME STORY REGARDING STRENGTH. A SIMILAR CONVECTIVE PATTERN WILL BE POSSIBLE BOTH TUESDAY AND WEDNESDAY...BUT WITH THE BETTER LATE-MORNING CHANCES PUSHING A LITTLE FURTHER EAST EACH DAY DUE TO THE UPPER RIDGE BUILDING IN FROM THE WEST. THAT UPPER RIDGE IS ALSO GOING TO WARM THINGS UP FOR THE FIRST PART OF THE WEEK. MANY MOS GUIDANCE VALUES ARE STILL SUGGESTING 95-97 BY TUESDAY AND WEDNESDAY BUT I`M STILL NOT BUYING THESE VALUES. CLOUD COVER WILL BE PLENTIFUL EACH AFTERNOON AND WITH THE FACT THAT THE RIDGE AXIS DOESN`T GET DIRECTLY OVERHEAD BEFORE FLATTENING OUT WEDNESDAY...I`M STILL GOING TO RUN A COUPLE OF DEGREE BELOW THESE MOS VALUES. THAT ISN`T TO SAY IT ISN`T GOING TO BE HOT AND STEAMY THROUGH MID-WEEK. IT IS. HEAT INDICIES OF 100-105 ARE GOING TO BE PREVALENT BECAUSE OF LOW 70S DEW POINTS AND ANY INCREASE TOWARDS THOSE 95-97 DEGREE READINGS WILL PUSH US INTO HEAT ADVISORY CRITERIA. FOR NOW...WILL COVER ELEVATED HEAT INDICIES WITH A SPECIAL WEATHER STATEMENT AND MONITOR FOR THE NEED OF AN ADVISORY EACH DAY. UNFORTUNATELY THERE WON`T BE MUCH RELIEF IN THE WAY OF OVERNIGHT LOWS. MANY SPOTS WON`T FALL PAST THE MID-70S TUESDAY AND WEDNESDAY MORNINGS...ESPECIALLY WEST OF THE PLATEAU. BY EARLY THURSDAY MORNING MODELS ARE STILL IN GOOD AGREEMENT ON THE PASSAGE OF A WEAK FRONTAL SYSTEM. THE ONLY THING THIS FRONT WILL DO IS ALLOW FOR A SLIGHTLY BETTER FOCUSING MECHANISM FOR THUNDERSTORMS TO DEVELOP. NOT CONCERNED ABOUT SEVERE AS THE MAIN ENERGY FROM THIS SYSTEM IS WELL OFF INTO EASTERN CANADA. WILL MAINTAIN CHANCE POPS FOR NOW. FRIDAY THROUGH THE WEEKEND STILL LOOKS DRY WITH TEMPERATURES FALLING BACK TOWARDS NORMAL VALUES. UNGER AVIATION... 06Z TAF DISCUSSION. UPPER HIGH WILL BE CENTERED OVER TX THIS TAF PD. WEAK NW FLOW WILL RESULT ACROSS OUR AREA WITH NO FRONTAL PASSAGES EXPECTED. CONVECTIVE PARAMETERS DO NOT LOOK FAVORABLE FOR CONVECTIVE DEVELOPMENT. HOWEVER...ISOL CONVECTION MAY OCCUR ALONG THE PLATEAU BETWEEN 18Z AND 00Z. OTW...PATCHY FOG AGAIN EXPECTED TOWARD 12Z FOR ALL THE TAF SITES. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 93 74 94 75 / 20 10 20 20 CLARKSVILLE 91 72 92 73 / 20 10 20 20 CROSSVILLE 87 70 87 70 / 30 20 30 30 COLUMBIA 94 73 94 73 / 20 0 20 20 LAWRENCEBURG 93 72 94 73 / 10 10 20 20 WAVERLY 92 73 93 74 / 20 10 20 20 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 55
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
613 AM CDT MON JUL 27 2015 .UPDATE... UPDATED FOR 12Z AVIATION DISCUSSION... && .PREV DISCUSSION... /ISSUED 413 AM CDT MON JUL 27 2015/ DISCUSSION... EXCESSIVE HEAT WILL INCREASE AND EXPAND OVER THE MIDSOUTH FROM THE WEST THROUGH WEDNESDAY. EARLY THIS MORNING...SOME MIDDLE LEVEL CLOUDS WERE FORMING ACROSS PORTIONS OF THE AREA BUT NO RAIN WAS OCCURRING. TEMPERATURES WERE IN THE 70S EXCEPT FOR A FEW LOWER 80S ALONG AND WEST OF THE MS RIVER. WATCHING A DEVELOPING COMPLEX OF THUNDERSTORMS ACROSS SOUTHERN IL THAT IS MOVING SOUTHEASTWARD. OUTFLOW BOUNDARIES FROM THIS COMPLEX MAY LEAD TO SCATTERED THUNDERSTORMS AFFECTING PORTIONS OF WEST TN ALONG THE TN RIVER INCLUDING PARIS...THUS INCLUDED A CHANCE OF THUNDERSTORMS FOR THIS AREA. THE HRRR AND RAP INDICATE ADDITIONAL THUNDERSTORMS MAY MOVE INTO EXTREME NORTHEAST AR...THE MO BOOTHEEL...AND THE REMAINDER OF THE EXTREME NORTHERN PORTIONS OF WEST TN FROM THE NORTHWEST TODAY...THUS INDICATED SLIGHT CHANCE POPS FOR THIS AREA. ELSEWHERE KEPT POPS BELOW MENTIONABLE LEVELS...ALTHOUGH A STRAY THUNDERSTORM IS POSSIBLE ANYWHERE WITH THE HIGH HEAT AND HUMIDITY. STRONG HIGH PRESSURE ALOFT OVER THE SOUTHERN PLAINS WILL GRADUALLY MOVE EASTWARD BECOMING CENTERED OVER THE OZARKS TUESDAY WITH 500 MB HEIGHTS INCREASING TO 594 DM. A HEAT ADVISORY HAS BEEN POSTED FOR TODAY THROUGH TUESDAY EVENING FOR NORTHEAST AND EAST CENTRAL AR...THE MO BOOTHEEL...PORTIONS OF WEST TN AND NORTHWEST MS. THE ADVISORY WILL LIKELY NEED TO BE EXPANDED TO INCLUDE THE ENTIRE MIDSOUTH BY WEDNESDAY. LATER FORECASTS MAY ALSO NEED TO CONSIDER AN EXCESSIVE HEAT WARNING FOR PORTIONS OF THE REGION WITH HEAT INDEX READINGS POSSIBLY TOPPING 110 DEGREES IN SOME LOCATIONS. SURFACE DEW POINTS WILL PROBABLY POOL AHEAD OF AN APPROACHING COLD FRONT WEDNESDAY LEADING TO GREATER HUMIDITY AND EVEN MORE OPPRESSIVE CONDITIONS. MODELS ARE IN AGREEMENT IN WEAKENING THE UPPER LEVEL RIDGE ACROSS THE MIDSOUTH WEDNESDAY NIGHT. A COLD FRONT IS FORECAST TO MOVE QUICKLY THROUGH THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. MODELS ARE NOT INDICATING MUCH CONVECTION AND MINIMUM RAINFALL WITH THE FRONT. NOT SURE ABOUT THIS CONSIDERING HOW WARM AND HUMID IT WILL BE ADVANCE OF THE FRONT...ALTHOUGH UPPER LEVEL SUPPORT WILL BE NON-EXISTENT. WILL MENTION A THREAT OF A FEW STRONG THUNDERSTORMS AND LOCALLY HEAVY DOWNPOURS IN THE HAZARDOUS WEATHER OUTLOOK WITH THE FRONTAL PASSAGE. THE COLD FRONT IS NOW FORECAST TO PUSH SOUTH OF THE MIDSOUTH THURSDAY MORNING. WELCOME RELIEF FROM THE HEAT AND HUMIDITY WILL OCCUR AS DRIER AND COOLER AIR FOLLOWS THE FRONT PERSISTING INTO THE FIRST HALF OF THE WEEKEND. HIGH PRESSURE ALOFT WILL BEGIN TO BUILD INTO THE AREA SUNDAY WITH INCREASING TEMPERATURES BUT CONTINUED DRY WEATHER. JCL .AVIATION... 12Z TAF CYCLE VFR CONDITIONS EXPECTED WITH THE EXCEPTION OF MKL THROUGH THE PERIOD. SHALLOW FOG CONTINUES TO PERIODICALLY REDUCE VISBYS BELOW 3SM THIS MORNING BUT THIS SHOULD BURN OFF BY 14Z. DURING THE DAY ON MONDAY...ISOLATED THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON HOURS AT MKL WITH ALL OTHER TERMINALS LIKELY REMAINING DRY. FOG WILL LIKELY DEVELOP AGAIN AT MKL OVERNIGHT WITH SIMILAR REDUCTIONS IN VISBYS EXPECTED. TVT && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR COAHOMA-DESOTO- LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA- YALOBUSHA. TN...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DYER-FAYETTE-LAKE- LAUDERDALE-SHELBY-TIPTON. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
413 AM CDT MON JUL 27 2015 .DISCUSSION... EXCESSIVE HEAT WILL INCREASE AND EXPAND OVER THE MIDSOUTH FROM THE WEST THROUGH WEDNESDAY. EARLY THIS MORNING...SOME MIDDLE LEVEL CLOUDS WERE FORMING ACROSS PORTIONS OF THE AREA BUT NO RAIN WAS OCCURRING. TEMPERATURES WERE IN THE 70S EXCEPT FOR A FEW LOWER 80S ALONG AND WEST OF THE MS RIVER. WATCHING A DEVELOPING COMPLEX OF THUNDERSTORMS ACROSS SOUTHERN IL THAT IS MOVING SOUTHEASTWARD. OUTFLOW BOUNDARIES FROM THIS COMPLEX MAY LEAD TO SCATTERED THUNDERSTORMS AFFECTING PORTIONS OF WEST TN ALONG THE TN RIVER INCLUDING PARIS...THUS INCLUDED A CHANCE OF THUNDERSTORMS FOR THIS AREA. THE HRRR AND RAP INDICATE ADDITIONAL THUNDERSTORMS MAY MOVE INTO EXTREME NORTHEAST AR...THE MO BOOTHEEL...AND THE REMAINDER OF THE EXTREME NORTHERN PORTIONS OF WEST TN FROM THE NORTHWEST TODAY...THUS INDICATED SLIGHT CHANCE POPS FOR THIS AREA. ELSEWHERE KEPT POPS BELOW MENTIONABLE LEVELS...ALTHOUGH A STRAY THUNDERSTORM IS POSSIBLE ANYWHERE WITH THE HIGH HEAT AND HUMIDITY. STRONG HIGH PRESSURE ALOFT OVER THE SOUTHERN PLAINS WILL GRADUALLY MOVE EASTWARD BECOMING CENTERED OVER THE OZARKS TUESDAY WITH 500 MB HEIGHTS INCREASING TO 594 DM. A HEAT ADVISORY HAS BEEN POSTED FOR TODAY THROUGH TUESDAY EVENING FOR NORTHEAST AND EAST CENTRAL AR...THE MO BOOTHEEL...PORTIONS OF WEST TN AND NORTHWEST MS. THE ADVISORY WILL LIKELY NEED TO BE EXPANDED TO INCLUDE THE ENTIRE MIDSOUTH BY WEDNESDAY. LATER FORECASTS MAY ALSO NEED TO CONSIDER AN EXCESSIVE HEAT WARNING FOR PORTIONS OF THE REGION WITH HEAT INDEX READINGS POSSIBLY TOPPING 110 DEGREES IN SOME LOCATIONS. SURFACE DEW POINTS WILL PROBABLY POOL AHEAD OF AN APPROACHING COLD FRONT WEDNESDAY LEADING TO GREATER HUMIDITY AND EVEN MORE OPPRESSIVE CONDITIONS. MODELS ARE IN AGREEMENT IN WEAKENING THE UPPER LEVEL RIDGE ACROSS THE MIDSOUTH WEDNESDAY NIGHT. A COLD FRONT IS FORECAST TO MOVE QUICKLY THROUGH THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. MODELS ARE NOT INDICATING MUCH CONVECTION AND MINIMUM RAINFALL WITH THE FRONT. NOT SURE ABOUT THIS CONSIDERING HOW WARM AND HUMID IT WILL BE ADVANCE OF THE FRONT...ALTHOUGH UPPER LEVEL SUPPORT WILL BE NON-EXISTENT. WILL MENTION A THREAT OF A FEW STRONG THUNDERSTORMS AND LOCALLY HEAVY DOWNPOURS IN THE HAZARDOUS WEATHER OUTLOOK WITH THE FRONTAL PASSAGE. THE COLD FRONT IS NOW FORECAST TO PUSH SOUTH OF THE MIDSOUTH THURSDAY MORNING. WELCOME RELIEF FROM THE HEAT AND HUMIDITY WILL OCCUR AS DRIER AND COOLER AIR FOLLOWS THE FRONT PERSISTING INTO THE FIRST HALF OF THE WEEKEND. HIGH PRESSURE ALOFT WILL BEGIN TO BUILD INTO THE AREA SUNDAY WITH INCREASING TEMPERATURES BUT CONTINUED DRY WEATHER. JCL && .AVIATION... 06Z TAF CYCLE MAINLY VFR CONDS WILL PREVAIL FOR THE PERIOD. EXPECT MOSTLY CLEAR SKIES WITH SOME PATCHY LIGHT FOG POSSIBLE AT KMKL. WINDS WILL BE LIGHT THROUGH THE PERIOD....GENERALLY FROM SOUTH TO SOUTHWEST. AN ISOLATED THUNDERSTORMS CANNOT BE RULED OUT TOMORROW. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR CLAY-CRAIGHEAD- CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI- PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DUNKLIN-PEMISCOT. MS...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR COAHOMA-DESOTO- LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA- YALOBUSHA. TN...HEAT ADVISORY UNTIL 8 PM CDT TUESDAY FOR DYER-FAYETTE-LAKE- LAUDERDALE-SHELBY-TIPTON. && $$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
322 PM CDT Mon Jul 27 2015 .SHORT TERM... (Tonight and Tuesday) A cumulus field was developing east of a Sweetwater to Junction line early this afternoon. The HRRR model develops isolated showers and thunderstorms in the Big Country this afternoon/early evening, while the Texas Tech WRF model has a few storms along the I-10 corridor. Expanded coverage of isolated showers and thunderstorms to include the Big Country counties this afternoon/evening, with storms ending by sunset. Models have a slight cooling by a degree or two Tuesday as the center of upper high pressure moves north into Oklahoma. Unfortunately this still means highs in the upper 90s to around 102, with the warmest readings in the Concho Valley. 04 .LONG TERM... (Tuesday night through Monday) Hot and dry conditions are anticipated across West Central Texas for much of the work-week as the subtropical ridge remains entrenched over the southern plains. Temperatures are expected to moderate slightly through Thursday as mid-level temperatures gradually drop by 1-2C. This will put max temperatures at or below 100 degrees by midweek, with overnight lows remaining in the mid 70s. We should see an afternoon cu field each afternoon, but large scale subsidence should preclude convective initiation. Heat indices are expected to remain below 105 degrees, precluding the need for a Heat Advisory. The mid/upper-level anticyclone is progged to build toward the west late this week, eventually centering over the Four Corners area this weekend. As the ridge builds west, the flow aloft will become northwesterly, opening the door for weak shortwave troughs to move across the region. A slug of enhanced moisture will move west across the Lone Star state late in the week and is forecast to increase precipitable water values to near 1.7" over the southeast portion of the CWA on Friday. With temperatures approaching 100 degrees, the cap is expected to break, allowing a few diurnal showers and thunderstorms to develop. Slight chance PoPs were added for areas east of a line from Sonora, to Ballinger to Throckmorton. This moisture will hang around through Saturday, where slight chance PoPs continue areawide. The ridge builds back east on Sunday, with hot and dry weather returning to the CWA. Expect temperatures near or back above 100 degrees across much of the area by Sunday. Johnson && .PRELIMINARY POINT TEMPS/POPS... Abilene 76 98 76 98 76 / 10 5 0 5 0 San Angelo 75 102 76 101 75 / 10 5 0 5 0 Junction 74 100 75 98 73 / 10 5 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 04/25
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1213 PM CDT MON JUL 27 2015 .AVIATION DISCUSSION...FOR 18Z TAF PACKAGE... LATEST VIS SATELLITE SHOWS DECREASING MVFR DECK OVER THE RIO GRANDE VALLEY AND SOME SCATTERED VFR CUMULUS OCCURRING EAST OF THE I35 CORRIDOR MAINLY. DURING PEAK HEATING THIS AFTERNOON...SHOULD SEE AN INCREASE IN THE CONVECTIVE CLOUD COVERAGE BUT NOT EXPECTING A CATEGORY CHANGE AS CLOUD HEIGHTS SHOULD BE ABOVE 3KFT. OVERNIGHT PATTERN LOOKS TO BE VERY SIMILAR TO PREVIOUS FEW NIGHTS WITH MVFR CIGS DEVELOPING AROUND THE 08-09Z TIME FRAME FOR KAUS/KSAT/KSSF AND IMPROVING BY MID MORNING AGAIN. KDRT MAY SEE SOME BRIEF 1500FT CIGS BUT LEFT AS SCATTERED FOR THIS FORECAST. && .PREV DISCUSSION... /ISSUED 1059 AM CDT MON JUL 27 2015/ UPDATE... NO MAJOR CHANGES ARE NEEDED TO THE FORECAST. CLOUD COVER IS STILL PERSISTING ACROSS THE SOUTHWESTERN COUNTIES AND TEMPERATURES ARE RUNNING 1-4 DEGREES COOLER THAN THIS TIME YESTERDAY. TEMPS SHOULD RAPIDLY WARM THIS AFTERNOON AND HIGHS SHOULD REMAIN IN THE 100-102 DEGREE RANGE OUT THERE WITH HEAT INDEX VALUES AROUND 108-110. ONLY MADE MINOR ADJUSTMENTS TO THE HOURLY GRIDS. PREV DISCUSSION... /ISSUED 625 AM CDT MON JUL 27 2015/ AVIATION... NO SIGNIFICANT CHANGES TO TAFS FOR THIS PERIOD. MVFR CIGS IN AUSTIN AND SAN ANTONIO WILL LINGER UNTIL LATE MORNING WHEN THEY WILL SCATTER TO VFR. THE ONGOING PATTERN WILL REPEAT AGAIN TONIGHT WITH MVFR CIGS FORMING OVERNIGHT. DRT WILL BE VFR THROUGH THE ENTIRE PERIOD. PREV DISCUSSION... /ISSUED 328 AM CDT MON JUL 27 2015/ SHORT TERM (TODAY THROUGH TUESDAY)...THE UPPER LEVEL RIDGE SHIFTS SLIGHTLY TO THE EAST-NORTHEAST TODAY...CENTERING OVER OKLAHOMA. A SLIGHT DECREASE IN 1000-500 MB THICKNESS VALUES THE NEXT TWO DAYS WILL YIELD MAX TEMPS A DEG OR SO COOLER IN SOME AREAS THAN OVER THE WEEKEND...BUT STILL WARM. HEAT INDEX VALUES IN THE 103 TO 108 RANGE THIS AFTERNOON ALONG AND SOUTH OF A DEL RIO TO SAN ANTONIO TO BASTROP LINE. A FEW LOCATIONS DOWN NEAR EAGLE PASS TO COTULLA MAY BRIEFLY SEE HEAT INDEX VALUES CLIMB TO AROUND 110. WILL CONTINUE WITH SPS AND HWO HIGHLIGHTS. LATE YESTERDAY AFTERNOON ISOLATED SHOWERS AND STORMS DEVELOPED ACROSS THE NORTHERN EDWARDS PLATEAU...WHERE A SLIGHTLY BETTER POOL OF PWATS RESIDED AND AFTERNOON TEMPS HIT 100-105. SEVERAL OF THE HI RESOLUTION MODELS HAD PICKED UP ON THIS YESTERDAY. THIS MORNING SSEO HI RESOLUTION MEMBERS ALONG WITH TEXAS TECH WRF AND SEVERAL RECENT RUNS OF THE HRRR ARE KEYING IN ON THIS REGION AGAIN TODAY FOR CONVECTIVE INITIATION. PWATS HAVE SLIGHTLY DECREASED...BUT AN ELEVATED POOL DOES EXIST...POSSIBLY SLIGHTLY FARTHER WEST THAN YESTERDAY. WITH CONVECTIVE TEMPS THIS AFTERNOON IN THE UPPER 90S ACROSS THIS REGION AND FORECAST HIGHS AROUND 98 TO 100 THE POSSIBILITY OF ISOLATED SHOWERS AND STORMS EXISTS AGAIN LATE THIS AFTERNOON. HAVE INCLUDED IN TODAY`S LATE AFTERNOON AND EARLY EVENING FORECAST A LESS THAN 20 PERCENT POP ALONG AND NORTH/NORTHWEST OF A PANDALE TO MOUNTAIN HOME TO LLANO LINE. A FEW STRONGER WIND GUSTS CAN NOT BE RULED OUT SHOULD THESE STORMS FORM. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...BOTH THE GFS AND ECMWF SHOW THE UPPER LEVEL RIDGE FLATTENING SOUTHWEST BACK ACROSS TEXAS WEDNESDAY AND THURSDAY...WITH THICKNESS VALUES INCREASING SLIGHTLY OVER SOUTH-CENTRAL TEXAS. MAX TEMPS MAY INCREASE A DEG OR TWO DURING THIS TIME. THE RIDGE BUILDS WESTWARD THURSDAY NIGHT THROUGH SATURDAY...CENTERING NEAR THE FOUR CORNERS. A DEEP EAST TO NORTHEAST FLOW DEVELOPS OVER THE AREA DURING THIS TIME. PWAT VALUES OF AROUND 1.8-2 INCHES POOL INTO THE AREA FROM THE EAST- NORTHEAST AHEAD OF A WEAK COLD FRONT. THE FRINGES OF THE MOISTURE ARRIVE ACROSS THE FAR EASTERN COUNTIES AS EARLY AS THURSDAY...WHERE ISOLATED POPS ARE FORECAST. POPS SPREAD WESTWARD FRIDAY AND POSSIBLY INTO SATURDAY ACROSS MUCH OF THE CWA...WITH COVERAGE AT THIS TIME LOOKING TO REMAIN ISOLATED TO WIDELY SCATTERED. THE RIDGE EXPANDS BACK TO THE EAST SUNDAY INTO MONDAY WITH DRY AND WARM CONDITIONS EXPECTED ACROSS SOUTH-CENTRAL TEXAS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 76 98 75 99 76 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 75 98 73 98 75 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 75 97 73 98 74 / 0 0 0 0 0 BURNET MUNI AIRPORT 73 96 73 98 75 / - 0 0 0 0 DEL RIO INTL AIRPORT 78 100 78 99 77 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 75 97 75 98 76 / - 0 0 0 0 HONDO MUNI AIRPORT 75 97 73 98 72 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 75 97 73 98 74 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 76 97 75 98 75 / - 10 0 - 0 SAN ANTONIO INTL AIRPORT 76 98 75 98 75 / 0 0 0 0 0 STINSON MUNI AIRPORT 76 98 75 99 74 / 0 - 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...TB3 SYNOPTIC/GRIDS...HAMPSHIRE PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1059 AM CDT MON JUL 27 2015 .UPDATE... NO MAJOR CHANGES ARE NEEDED TO THE FORECAST. CLOUD COVER IS STILL PERSISTING ACROSS THE SOUTHWESTERN COUNTIES AND TEMPERATURES ARE RUNNING 1-4 DEGREES COOLER THAN THIS TIME YESTERDAY. TEMPS SHOULD RAPIDLY WARM THIS AFTERNOON AND HIGHS SHOULD REMAIN IN THE 100-102 DEGREE RANGE OUT THERE WITH HEAT INDEX VALUES AROUND 108-110. ONLY MADE MINOR ADJUSTMENTS TO THE HOURLY GRIDS. && .PREV DISCUSSION... /ISSUED 625 AM CDT MON JUL 27 2015/ AVIATION... NO SIGNIFICANT CHANGES TO TAFS FOR THIS PERIOD. MVFR CIGS IN AUSTIN AND SAN ANTONIO WILL LINGER UNTIL LATE MORNING WHEN THEY WILL SCATTER TO VFR. THE ONGOING PATTERN WILL REPEAT AGAIN TONIGHT WITH MVFR CIGS FORMING OVERNIGHT. DRT WILL BE VFR THROUGH THE ENTIRE PERIOD. PREV DISCUSSION... /ISSUED 328 AM CDT MON JUL 27 2015/ SHORT TERM (TODAY THROUGH TUESDAY)...THE UPPER LEVEL RIDGE SHIFTS SLIGHTLY TO THE EAST-NORTHEAST TODAY...CENTERING OVER OKLAHOMA. A SLIGHT DECREASE IN 1000-500 MB THICKNESS VALUES THE NEXT TWO DAYS WILL YIELD MAX TEMPS A DEG OR SO COOLER IN SOME AREAS THAN OVER THE WEEKEND...BUT STILL WARM. HEAT INDEX VALUES IN THE 103 TO 108 RANGE THIS AFTERNOON ALONG AND SOUTH OF A DEL RIO TO SAN ANTONIO TO BASTROP LINE. A FEW LOCATIONS DOWN NEAR EAGLE PASS TO COTULLA MAY BRIEFLY SEE HEAT INDEX VALUES CLIMB TO AROUND 110. WILL CONTINUE WITH SPS AND HWO HIGHLIGHTS. LATE YESTERDAY AFTERNOON ISOLATED SHOWERS AND STORMS DEVELOPED ACROSS THE NORTHERN EDWARDS PLATEAU...WHERE A SLIGHTLY BETTER POOL OF PWATS RESIDED AND AFTERNOON TEMPS HIT 100-105. SEVERAL OF THE HI RESOLUTION MODELS HAD PICKED UP ON THIS YESTERDAY. THIS MORNING SSEO HI RESOLUTION MEMBERS ALONG WITH TEXAS TECH WRF AND SEVERAL RECENT RUNS OF THE HRRR ARE KEYING IN ON THIS REGION AGAIN TODAY FOR CONVECTIVE INITIATION. PWATS HAVE SLIGHTLY DECREASED...BUT AN ELEVATED POOL DOES EXIST...POSSIBLY SLIGHTLY FARTHER WEST THAN YESTERDAY. WITH CONVECTIVE TEMPS THIS AFTERNOON IN THE UPPER 90S ACROSS THIS REGION AND FORECAST HIGHS AROUND 98 TO 100 THE POSSIBILITY OF ISOLATED SHOWERS AND STORMS EXISTS AGAIN LATE THIS AFTERNOON. HAVE INCLUDED IN TODAY`S LATE AFTERNOON AND EARLY EVENING FORECAST A LESS THAN 20 PERCENT POP ALONG AND NORTH/NORTHWEST OF A PANDALE TO MOUNTAIN HOME TO LLANO LINE. A FEW STRONGER WIND GUSTS CAN NOT BE RULED OUT SHOULD THESE STORMS FORM. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...BOTH THE GFS AND ECMWF SHOW THE UPPER LEVEL RIDGE FLATTENING SOUTHWEST BACK ACROSS TEXAS WEDNESDAY AND THURSDAY...WITH THICKNESS VALUES INCREASING SLIGHTLY OVER SOUTH-CENTRAL TEXAS. MAX TEMPS MAY INCREASE A DEG OR TWO DURING THIS TIME. THE RIDGE BUILDS WESTWARD THURSDAY NIGHT THROUGH SATURDAY...CENTERING NEAR THE FOUR CORNERS. A DEEP EAST TO NORTHEAST FLOW DEVELOPS OVER THE AREA DURING THIS TIME. PWAT VALUES OF AROUND 1.8-2 INCHES POOL INTO THE AREA FROM THE EAST- NORTHEAST AHEAD OF A WEAK COLD FRONT. THE FRINGES OF THE MOISTURE ARRIVE ACROSS THE FAR EASTERN COUNTIES AS EARLY AS THURSDAY...WHERE ISOLATED POPS ARE FORECAST. POPS SPREAD WESTWARD FRIDAY AND POSSIBLY INTO SATURDAY ACROSS MUCH OF THE CWA...WITH COVERAGE AT THIS TIME LOOKING TO REMAIN ISOLATED TO WIDELY SCATTERED. THE RIDGE EXPANDS BACK TO THE EAST SUNDAY INTO MONDAY WITH DRY AND WARM CONDITIONS EXPECTED ACROSS SOUTH-CENTRAL TEXAS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 98 76 98 75 99 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 97 75 98 73 98 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 97 75 97 73 98 / 0 0 0 0 0 BURNET MUNI AIRPORT 96 73 96 73 98 / - - 0 0 0 DEL RIO INTL AIRPORT 101 78 100 78 99 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 97 75 97 75 98 / - - 0 0 0 HONDO MUNI AIRPORT 98 75 97 73 98 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 97 75 97 73 98 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 97 76 97 75 98 / - - 10 0 - SAN ANTONIO INTL AIRPORT 98 76 98 75 98 / 0 0 0 0 0 STINSON MUNI AIRPORT 99 76 98 75 99 / 0 0 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...TB3 SYNOPTIC/GRIDS...HAMPSHIRE PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
625 AM CDT MON JUL 27 2015 .AVIATION... NO SIGNIFICANT CHANGES TO TAFS FOR THIS PERIOD. MVFR CIGS IN AUSTIN AND SAN ANTONIO WILL LINGER UNTIL LATE MORNING WHEN THEY WILL SCATTER TO VFR. THE ONGOING PATTERN WILL REPEAT AGAIN TONIGHT WITH MVFR CIGS FORMING OVERNIGHT. DRT WILL BE VFR THROUGH THE ENTIRE PERIOD. && .PREV DISCUSSION... /ISSUED 328 AM CDT MON JUL 27 2015/ SHORT TERM (TODAY THROUGH TUESDAY)...THE UPPER LEVEL RIDGE SHIFTS SLIGHTLY TO THE EAST-NORTHEAST TODAY...CENTERING OVER OKLAHOMA. A SLIGHT DECREASE IN 1000-500 MB THICKNESS VALUES THE NEXT TWO DAYS WILL YIELD MAX TEMPS A DEG OR SO COOLER IN SOME AREAS THAN OVER THE WEEKEND...BUT STILL WARM. HEAT INDEX VALUES IN THE 103 TO 108 RANGE THIS AFTERNOON ALONG AND SOUTH OF A DEL RIO TO SAN ANTONIO TO BASTROP LINE. A FEW LOCATIONS DOWN NEAR EAGLE PASS TO COTULLA MAY BRIEFLY SEE HEAT INDEX VALUES CLIMB TO AROUND 110. WILL CONTINUE WITH SPS AND HWO HIGHLIGHTS. LATE YESTERDAY AFTERNOON ISOLATED SHOWERS AND STORMS DEVELOPED ACROSS THE NORTHERN EDWARDS PLATEAU...WHERE A SLIGHTLY BETTER POOL OF PWATS RESIDED AND AFTERNOON TEMPS HIT 100-105. SEVERAL OF THE HI RESOLUTION MODELS HAD PICKED UP ON THIS YESTERDAY. THIS MORNING SSEO HI RESOLUTION MEMBERS ALONG WITH TEXAS TECH WRF AND SEVERAL RECENT RUNS OF THE HRRR ARE KEYING IN ON THIS REGION AGAIN TODAY FOR CONVECTIVE INITIATION. PWATS HAVE SLIGHTLY DECREASED...BUT AN ELEVATED POOL DOES EXIST...POSSIBLY SLIGHTLY FARTHER WEST THAN YESTERDAY. WITH CONVECTIVE TEMPS THIS AFTERNOON IN THE UPPER 90S ACROSS THIS REGION AND FORECAST HIGHS AROUND 98 TO 100 THE POSSIBILITY OF ISOLATED SHOWERS AND STORMS EXISTS AGAIN LATE THIS AFTERNOON. HAVE INCLUDED IN TODAY`S LATE AFTERNOON AND EARLY EVENING FORECAST A LESS THAN 20 PERCENT POP ALONG AND NORTH/NORTHWEST OF A PANDALE TO MOUNTAIN HOME TO LLANO LINE. A FEW STRONGER WIND GUSTS CAN NOT BE RULED OUT SHOULD THESE STORMS FORM. LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...BOTH THE GFS AND ECMWF SHOW THE UPPER LEVEL RIDGE FLATTENING SOUTHWEST BACK ACROSS TEXAS WEDNESDAY AND THURSDAY...WITH THICKNESS VALUES INCREASING SLIGHTLY OVER SOUTH-CENTRAL TEXAS. MAX TEMPS MAY INCREASE A DEG OR TWO DURING THIS TIME. THE RIDGE BUILDS WESTWARD THURSDAY NIGHT THROUGH SATURDAY...CENTERING NEAR THE FOUR CORNERS. A DEEP EAST TO NORTHEAST FLOW DEVELOPS OVER THE AREA DURING THIS TIME. PWAT VALUES OF AROUND 1.8-2 INCHES POOL INTO THE AREA FROM THE EAST- NORTHEAST AHEAD OF A WEAK COLD FRONT. THE FRINGES OF THE MOISTURE ARRIVE ACROSS THE FAR EASTERN COUNTIES AS EARLY AS THURSDAY...WHERE ISOLATED POPS ARE FORECAST. POPS SPREAD WESTWARD FRIDAY AND POSSIBLY INTO SATURDAY ACROSS MUCH OF THE CWA...WITH COVERAGE AT THIS TIME LOOKING TO REMAIN ISOLATED TO WIDELY SCATTERED. THE RIDGE EXPANDS BACK TO THE EAST SUNDAY INTO MONDAY WITH DRY AND WARM CONDITIONS EXPECTED ACROSS SOUTH-CENTRAL TEXAS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 98 76 98 75 99 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 97 75 98 73 98 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 97 75 97 73 98 / 0 0 0 0 0 BURNET MUNI AIRPORT 96 73 96 73 98 / - - 0 0 0 DEL RIO INTL AIRPORT 101 78 100 78 99 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 97 75 97 75 98 / - - 0 0 0 HONDO MUNI AIRPORT 98 75 97 73 98 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 97 75 97 73 98 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 97 76 97 75 98 / - - 10 0 - SAN ANTONIO INTL AIRPORT 98 76 98 75 98 / 0 0 0 0 0 STINSON MUNI AIRPORT 99 76 98 75 99 / 0 0 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...RUNYEN
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
328 AM CDT MON JUL 27 2015 .SHORT TERM (TODAY THROUGH TUESDAY)...THE UPPER LEVEL RIDGE SHIFTS SLIGHTLY TO THE EAST-NORTHEAST TODAY...CENTERING OVER OKLAHOMA. A SLIGHT DECREASE IN 1000-500 MB THICKNESS VALUES THE NEXT TWO DAYS WILL YIELD MAX TEMPS A DEG OR SO COOLER IN SOME AREAS THAN OVER THE WEEKEND...BUT STILL WARM. HEAT INDEX VALUES IN THE 103 TO 108 RANGE THIS AFTERNOON ALONG AND SOUTH OF A DEL RIO TO SAN ANTONIO TO BASTROP LINE. A FEW LOCATIONS DOWN NEAR EAGLE PASS TO COTULLA MAY BRIEFLY SEE HEAT INDEX VALUES CLIMB TO AROUND 110. WILL CONTINUE WITH SPS AND HWO HIGHLIGHTS. LATE YESTERDAY AFTERNOON ISOLATED SHOWERS AND STORMS DEVELOPED ACROSS THE NORTHERN EDWARDS PLATEAU...WHERE A SLIGHTLY BETTER POOL OF PWATS RESIDED AND AFTERNOON TEMPS HIT 100-105. SEVERAL OF THE HI RESOLUTION MODELS HAD PICKED UP ON THIS YESTERDAY. THIS MORNING SSEO HI RESOLUTION MEMBERS ALONG WITH TEXAS TECH WRF AND SEVERAL RECENT RUNS OF THE HRRR ARE KEYING IN ON THIS REGION AGAIN TODAY FOR CONVECTIVE INITIATION. PWATS HAVE SLIGHTLY DECREASED...BUT AN ELEVATED POOL DOES EXIST...POSSIBLY SLIGHTLY FARTHER WEST THAN YESTERDAY. WITH CONVECTIVE TEMPS THIS AFTERNOON IN THE UPPER 90S ACROSS THIS REGION AND FORECAST HIGHS AROUND 98 TO 100 THE POSSIBILITY OF ISOLATED SHOWERS AND STORMS EXISTS AGAIN LATE THIS AFTERNOON. HAVE INCLUDED IN TODAY`S LATE AFTERNOON AND EARLY EVENING FORECAST A LESS THAN 20 PERCENT POP ALONG AND NORTH/NORTHWEST OF A PANDALE TO MOUNTAIN HOME TO LLANO LINE. A FEW STRONGER WIND GUSTS CAN NOT BE RULED OUT SHOULD THESE STORMS FORM. && .LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...BOTH THE GFS AND ECMWF SHOW THE UPPER LEVEL RIDGE FLATTENING SOUTHWEST BACK ACROSS TEXAS WEDNESDAY AND THURSDAY...WITH THICKNESS VALUES INCREASING SLIGHTLY OVER SOUTH-CENTRAL TEXAS. MAX TEMPS MAY INCREASE A DEG OR TWO DURING THIS TIME. THE RIDGE BUILDS WESTWARD THURSDAY NIGHT THROUGH SATURDAY...CENTERING NEAR THE FOUR CORNERS. A DEEP EAST TO NORTHEAST FLOW DEVELOPS OVER THE AREA DURING THIS TIME. PWAT VALUES OF AROUND 1.8-2 INCHES POOL INTO THE AREA FROM THE EAST- NORTHEAST AHEAD OF A WEAK COLD FRONT. THE FRINGES OF THE MOISTURE ARRIVE ACROSS THE FAR EASTERN COUNTIES AS EARLY AS THURSDAY...WHERE ISOLATED POPS ARE FORECAST. POPS SPREAD WESTWARD FRIDAY AND POSSIBLY INTO SATURDAY ACROSS MUCH OF THE CWA...WITH COVERAGE AT THIS TIME LOOKING TO REMAIN ISOLATED TO WIDELY SCATTERED. THE RIDGE EXPANDS BACK TO THE EAST SUNDAY INTO MONDAY WITH DRY AND WARM CONDITIONS EXPECTED ACROSS SOUTH-CENTRAL TEXAS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 98 76 98 75 99 / 0 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 97 75 98 73 98 / 0 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 97 75 97 73 98 / 0 0 0 0 0 BURNET MUNI AIRPORT 96 73 96 73 98 / - - 0 0 0 DEL RIO INTL AIRPORT 101 78 100 78 99 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 97 75 97 75 98 / - - 0 0 0 HONDO MUNI AIRPORT 98 75 97 73 98 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 97 75 97 73 98 / 0 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 97 76 97 75 98 / - - 10 0 - SAN ANTONIO INTL AIRPORT 98 76 98 75 98 / 0 0 0 0 0 STINSON MUNI AIRPORT 99 76 98 75 99 / 0 0 - 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...RUNYEN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
951 PM EDT TUE JUL 28 2015 .SYNOPSIS... A DIFFUSE FRONTAL BOUNDARY WILL LINGER ACROSS THE REGION THROUGH WEDNESDAY BEFORE ANOTHER STRONGER COLD FRONT ARRIVES FROM THE NORTHWEST THURSDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE IN THE FORECAST UNTIL THE SECONDARY FRONT MOVES SOUTH OF THE REGION FRIDAY. SOMEWHAT DRIER AIR SHOULD FOLLOW THE FRONT FOR THE WEEKEND AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 945 PM EDT TUESDAY... WHILE THERE HAVE BEEN SOME TRENDS IN DECREASING COVERAGE OF SHOWERS AND STORMS AS A WHOLE...PARTS OF THE REGION CONTINUE TO RECEIVE ADDITIONAL HEAVY SHOWERS AND STORMS. THIS AREA OF GREATEST COVERAGE IS STILL WITHIN ROUGHLY A 50 MILES RADIUS OF LYNCHBURG VIRGINIA. OTHER LOCALLY HEAVY RAIN WAS MOVING SOUTH OF THE I-64 CORRIDOR...NEAR COVINGTON VIRGINIA. OTHER SHOWERS AND STORMS WERE CLUSTERED JUST EAST OF THE CREST OF THE BLUE RIDGE FROM ROUGHLY ROCKY MOUNT VIRGINIA...SOUTHWEST TO NEAR WILKESBORO NORTH CAROLINA. THE OVERALL TREND HAS NOT CHANGED FOR THE OVERNIGHT HOURS. PRECIPITATION COVERAGE WILL GRADUALLY DECREASE IN COVERAGE AND BECOME LOCATED MAINLY OVER SOUTHSIDE VIRGINIA...NORTH CENTRAL NORTH CAROLINA AND POINTS WEST TO NEAR THE CREST OF THE BLUE RIDGE. AS TEMPERATURES FALL TO NEAR THE DEW POINT VALUES...LOOK FOR A TREND OF INCREASE COVERAGE OF FOG...AS WELL AS...A TREND TOWARD LOWER VISIBILITIES WITHIN THAT FOG. LOW LEVEL STRATUS CLOUDS ALSO ARE LIKELY TO DEVELOP OVERNIGHT. NO CHANGES WERE MADE TO THE FORECAST LOW TEMPERATURES...BUT ADJUSTMENTS TO THE HOURLY TEMPERATURES THROUGH THE NEXT FEW HOURS WERE MADE BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS. AS OF 650 PM EDT TUESDAY... A GENEROUS COVERAGE OF SHOWERS AND SOME SCATTERED STORMS ARE ACROSS THE REGION THIS EVENING. MOST OF THEM ARE ALONG AND EAST OF A HOT SPRINGS VIRGINIA...ROANOKE VIRGINIA...MARION VIRGINIA LINE. THE GREATEST CONCENTRATION IS BOUNDED INSIDE THE AREA TO THE RIGHT OF A ROANOKE VIRGINIA...HOT SPRINGS VIRGINIA...AMHERST VIRGINIA...BEDFORD VIRGINIA...ROANOKE VIRGINIA LINE. AS THE EVENING PROGRESSES...BOTH DIAGNOSTIC GUIDANCE AND MESO-SCALE MODELS SUGGEST A GENERAL TREND OF THE ACTIVITY PROGRESSING SLOWLY SOUTHEAST...AND DISSIPATING THROUGH THE LATE EVENING. BY EARLY WEDNESDAY MORNING...MAINLY ISOLATED SHOWERS ARE EXPECTED TO EXIST...WITH THE BULK OF THESE BETWEEN THE CREST OF THE BLUE RIDGE AND SOUTHSIDE VIRGINIA...AND NEIGHBORING PARTS OF NORTH CENTRAL NORTH CAROLINA. AS OF 205 PM EDT TUESDAY... CLUSTERS OF DEEPER CONVECTION CONTINUE OVER THE SE ALONG AN AXIS OF HIGHER SURFACE BASED THETA-E/INSTABILITY AND OVER THE NW IN ASSOCIATION WITH THE RESIDUAL FRONT AND A WEAK WAVE ALOFT. MODELS AGAIN STRUGGLING WITH WHERE TO PAINT THE BEST CONVECTIVE COVERAGE INTO TONIGHT GIVEN WEAK FEATURES AND DIURNAL NATURE OF MORE OUTFLOW DRIVEN STORMS. HOWEVER SOME CONSENSUS OFF THE HRRR AND ENSEMBLES AS WELL AS THE GFS TO HAVE BEST HEAVY RAIN PRODUCING SHRA/TSRA OVER THE EAST AS THE WEAK SHORTWAVE TO THE NW DROPS THROUGH THE REGION GIVEN LINGERING INSTABILITY WELL INTO THE EVENING. THIS AREA THOUGH MAY BE TOO WORKED OVER BY THEN SO WILL TREND WITH HIGHER POPS THERE AFTER SUNSET BUT MAINLY OF THE HIGH CHANCE VARIETY AS ADDED PRECIP AFTER DARK MAY BE VOID OF DEEP CONVECTION. OTRW KEEPING THE SCATTERED NATURE REGIME GOING THROUGH ABOUT MIDNIGHT WEST...AND PERIODS OF LIKELYS OR HIGHER OUT EAST A WHILE LONGER BEFORE CUTTING TO PC/FOG LATE. AGAIN QUITE WARM/MUGGY WITH MANY EASTERN LOCATIONS STAY ABOVE 70 UNLESS SPOTS SEE A COOLING SHOWER INTO THIS EVENING. 5H HEIGHTS WILL BUILD A BIT ON WEDNESDAY AS THE AREA REMAINS IN A MOISTURE LADEN ENVIRONMENT UNDER WEAK SURFACE HIGH PRESSURE BUT WITH LESS FOCUS GIVEN THE WASHING OUT OF THE NEARBY FRONT. GUIDANCE SHOWS SOME CONVERGENCE ACROSS THE RIDGES DURING THE AFTERNOON ESPCLY AS THE FLOW TURNS MORE SW ALOFT WHICH SHOULD HELP FOCUS ADDED CONVECTION ALONG THE RIDGES. HOWEVER WITH THE NEXT UPSTREAM SHORTWAVE TROUGH WELL TO THE NW WITH THE NEXT COLD FRONT...APPEARS LIFT WILL BE LESS BUT LIKELY ENOUGH GIVEN STRONG INSTABILITY TO RESULT IN SCATTERED COVERAGE MOUNTAINS AND A BIT LESS IN THE EAST. STEERING REMAINS ON THE WEAK SIDE SO MAIN THREAT AGAIN WITH HEAVY RAINFALL. HIGH TEMPS IN LINE WITH THE LATEST MAV/MOS MIX SO ONLY MADE SMALL TWEAKS TO BUMP UP VALUES A LITTLE IN THE EAST WHERE SOME LOW 90S POSSIBLE. OTRW MUGGY 80S IN STORE. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 300 PM EDT TUESDAY... SCATTERED SHOWERS AND THUNDERSTORMS WILL DIMINISH WEDNESDAY EVENING INTO WEDNESDAY NIGHT. A COLD FRONT WILL APPROACH FROM THE WEST LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO LOWER 70S IN THE PIEDMONT. THE COLD FRONT WILL PUSH EAST ACROSS OUR AREA THURSDAY INTO THURSDAY NIGHT. AS HIGHLIGHTED IN SPC MARGINAL RISK...SOME STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE THURSDAY AFTERNOON AND EARLY EVENING. THE GREATEST THREAT WILL BE FOR PULSE SEVERE THUNDERSTORMS WITH DOWNBURST/LOCALIZED WIND DAMAGE POTENTIAL AS LOW-LEVEL LAPSE RATES STEEPEN THURSDAY AFTERNOON. THE SLIGHTLY STRONGER MID-LEVEL FLOW SHOULD REDUCE THE FLOOD POTENTIAL. HIGH TEMPERATURES THURSDAY WILL VARY FROM THE MID 70S IN THE NORTHWEST MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT. PLACED THE HIGHEST POPS IN THE EAST THURSDAY NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE LOWER 60S IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT. THE AMPLIFICATION OF THE SUBTROPICAL RIDGE INTO THE SOUTHWEST U.S. WILL RESULT IN STRENGTHENING NORTHWEST FLOW ALOFT ACROSS THE EAST COAST. THIS WILL PUSH THE COLD FRONT FURTHER SOUTH BEFORE STALLING IN SOUTHEAST LATE FRIDAY. COOLER HIGHS EXPECTED FRIDAY WITH READINGS FROM THE MID 70S IN THE NORTHWEST MOUNTAINS TO THE UPPER 80S IN THE PIEDMONT. LOWS TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE UPPER 50S IN THE WEST TO THE MID 60S IN THE EAST. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 PM EDT TUESDAY... A GOOD WEEKEND EXPECTED WITH DRY SEASONABLE TEMPERATURES AND HUMIDITY LEVELS...AS HIGH PRESSURE BUILD EAST OUT OF THE OHIO VALLEY. THERE ARE SEVERAL OTHER KEY PLAYERS IN THE MEDIUM RANGE FORECAST ESPECIALLY THE DEEPENING UPPER TROUGH AND PSEUDO-TROPICAL LOW. A BROAD UPPER TROUGH IS PROGGED TO REMAIN ACROSS EASTERN CANADA AND SHOULD DEEPEN INTO THE EASTERN UNITED STATES....THEN FLATTEN OUT EARLY NEXT WEEK. ANOTHER CONCERN FOR THIS PERIOD WILL BE AN AREA OF LOW PRESSURE WHICH DEVELOPS ACROSS FLORIDA OR IN THE GULF AND THE INTERACTION WITH STALLED FRONTAL BOUNDARY LOCATED ACROSS THE SOUTHEAST STATES. WITH RESPECT TO THE PSEUDO-TROPICAL LOW DEVELOPING ACROSS THE EASTERN GULF AND SOUTHEAST STATES...MODELS ARE IN BETTER AGREEMENT WITH THE UPPER TROUGH. THE ECMWF REMAINS THE MOST ROBUST COMPARED TO OTHER SOLUTIONS IN DEVELOPING A CLOSED SFC LOW...AND THEN TRACKING IT NORTHEAST ALONG THE SOUTHEAST COAST INTO EARLY NEXT WEEK. QUESTIONS REMAIN IN THE FORECAST ON WHETHER A WEAK FRONTAL BOUNDARY EARLY NEXT WEEK COULD PULL THE SOUTHEAST LOW PRESSURE CENTER AND ITS ASSOCIATED MOISTURE FURTHER INLAND ACROSS THE PIEDMONT OR BLOCK IT EAST OF THE AREA. IN ANY CASE...THE CHANCE FOR RAIN WILL BE INCREASING HEADING INTO EARLY NEXT WEEK. THE LOCATIONS WITH THE BETTER CHANCE OF RAIN WILL BE ACROSS THE PIEDMONT. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... AS OF 725 PM EDT TUESDAY... SHOWERS AND THUNDERSTORMS WERE SCATTERED ACROSS THE REGION WITH THE GREATEST COVERAGE ALONG AND EAST OF A KMKJ...KROA...KHSP LINE. WITHIN THE STRONGER CELLS...LOCALIZED IFR/MVFR CONDITIONS EXISTED. WITHIN THE LIGHTER CELLS...AND OUTSIDE OF THE PRECIPITATION REGION...VFR CONDITIONS PREVAILED. AS WE HEAD INTO THE OVERNIGHT HOURS...THE COVERAGE OF SHOWERS AND STORMS WILL DECREASE...AND THE DEW POINT DEPRESSION WILL START TO LESSEN. THE RESULT WILL BE AN INCREASING COVERAGE OF SUB-VFR CONDITIONS...NOT BECAUSE OF PRECIPITATION...BUT BECAUSE OF THE FORMATION OF BR/FG AND STRATUS CLOUDS. ANTICIPATE MOST AREAS TO TREND TOWARD MVFR CONDITIONS OVERNIGHT...WITH SEVERAL LOCATIONS IN THE IFR...OR EVEN LIFR...RANGE BY EARLY WEDNESDAY MORNING. FLIGHT CATEGORIES WILL BE SLOW TO IMPROVE AFTER SUNRISE...BUT MOST LOCATIONS WILL BE VFR BY NOONTIME. IN THE AFTERNOON...ANOTHER ROUND OF SHOWERS AND SOME THUNDERSTORMS ARE EXPECTED. AGAIN...LOCALIZED MVFR/IFR CONDITIONS WILL BE POSSIBLE UNDER THE HEAVIER CELLS...WITH THE REMAINDER OF THE REGION STAYING IN VFR. EXTENDED AVIATION FORECAST... AS OF 1235 PM EDT TUESDAY... MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED ON THURSDAY AS A COLD FRONT CROSSES THROUGH REGION FROM THE NORTHWEST. THIS FRONT SHOULD PUSH SOUTH OF THE AREA AND ALLOW FOR DRIER AND MOSTLY VFR CONDITIONS FRIDAY THROUGH SUNDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/RAB NEAR TERM...DS/JH SHORT TERM...KK LONG TERM...KK AVIATION...DS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
734 PM EDT TUE JUL 28 2015 .SYNOPSIS... A DIFFUSE FRONTAL BOUNDARY WILL LINGER ACROSS THE REGION THROUGH WEDNESDAY BEFORE ANOTHER STRONGER COLD FRONT ARRIVES FROM THE NORTHWEST THURSDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE IN THE FORECAST UNTIL THE SECONDARY FRONT MOVES SOUTH OF THE REGION FRIDAY. SOMEWHAT DRIER AIR SHOULD FOLLOW THE FRONT FOR THE WEEKEND AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 650 PM EDT TUESDAY... A GENEROUS COVERAGE OF SHOWERS AND SOME SCATTERED STORMS ARE ACROSS THE REGION THIS EVENING. MOST OF THEM ARE ALONG AND EAST OF A HOT SPRINGS VIRGINIA...ROANOKE VIRGINIA...MARION VIRGINIA LINE. THE GREATEST CONCENTRATION IS BOUNDED INSIDE THE AREA TO THE RIGHT OF A ROANOKE VIRGINIA...HOT SPRINGS VIRGINIA...AMHERST VIRGINIA...BEDFORD VIRGINIA...ROANOKE VIRGINIA LINE. AS THE EVENING PROGRESSES...BOTH DIAGNOSTIC GUIDANCE AND MESO-SCALE MODELS SUGGEST A GENERAL TREND OF THE ACTIVITY PROGRESSING SLOWLY SOUTHEAST...AND DISSIPATING THROUGH THE LATE EVENING. BY EARLY WEDNESDAY MORNING...MAINLY ISOLATED SHOWERS ARE EXPECTED TO EXIST...WITH THE BULK OF THESE BETWEEN THE CREST OF THE BLUE RIDGE AND SOUTHSIDE VIRGINIA...AND NEIGHBORING PARTS OF NORTH CENTRAL NORTH CAROLINA. AS OF 205 PM EDT TUESDAY... CLUSTERS OF DEEPER CONVECTION CONTINUE OVER THE SE ALONG AN AXIS OF HIGHER SURFACE BASED THETA-E/INSTABILITY AND OVER THE NW IN ASSOCIATION WITH THE RESIDUAL FRONT AND A WEAK WAVE ALOFT. MODELS AGAIN STRUGGLING WITH WHERE TO PAINT THE BEST CONVECTIVE COVERAGE INTO TONIGHT GIVEN WEAK FEATURES AND DIURNAL NATURE OF MORE OUTFLOW DRIVEN STORMS. HOWEVER SOME CONSENSUS OFF THE HRRR AND ENSEMBLES AS WELL AS THE GFS TO HAVE BEST HEAVY RAIN PRODUCING SHRA/TSRA OVER THE EAST AS THE WEAK SHORTWAVE TO THE NW DROPS THROUGH THE REGION GIVEN LINGERING INSTABILITY WELL INTO THE EVENING. THIS AREA THOUGH MAY BE TOO WORKED OVER BY THEN SO WILL TREND WITH HIGHER POPS THERE AFTER SUNSET BUT MAINLY OF THE HIGH CHANCE VARIETY AS ADDED PRECIP AFTER DARK MAY BE VOID OF DEEP CONVECTION. OTRW KEEPING THE SCATTERED NATURE REGIME GOING THROUGH ABOUT MIDNIGHT WEST...AND PERIODS OF LIKELYS OR HIGHER OUT EAST A WHILE LONGER BEFORE CUTTING TO PC/FOG LATE. AGAIN QUITE WARM/MUGGY WITH MANY EASTERN LOCATIONS STAY ABOVE 70 UNLESS SPOTS SEE A COOLING SHOWER INTO THIS EVENING. 5H HEIGHTS WILL BUILD A BIT ON WEDNESDAY AS THE AREA REMAINS IN A MOISTURE LADEN ENVIRONMENT UNDER WEAK SURFACE HIGH PRESSURE BUT WITH LESS FOCUS GIVEN THE WASHING OUT OF THE NEARBY FRONT. GUIDANCE SHOWS SOME CONVERGENCE ACROSS THE RIDGES DURING THE AFTERNOON ESPCLY AS THE FLOW TURNS MORE SW ALOFT WHICH SHOULD HELP FOCUS ADDED CONVECTION ALONG THE RIDGES. HOWEVER WITH THE NEXT UPSTREAM SHORTWAVE TROUGH WELL TO THE NW WITH THE NEXT COLD FRONT...APPEARS LIFT WILL BE LESS BUT LIKELY ENOUGH GIVEN STRONG INSTABILITY TO RESULT IN SCATTERED COVERAGE MOUNTAINS AND A BIT LESS IN THE EAST. STEERING REMAINS ON THE WEAK SIDE SO MAIN THREAT AGAIN WITH HEAVY RAINFALL. HIGH TEMPS IN LINE WITH THE LATEST MAV/MOS MIX SO ONLY MADE SMALL TWEAKS TO BUMP UP VALUES A LITTLE IN THE EAST WHERE SOME LOW 90S POSSIBLE. OTRW MUGGY 80S IN STORE. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 300 PM EDT TUESDAY... SCATTERED SHOWERS AND THUNDERSTORMS WILL DIMINISH WEDNESDAY EVENING INTO WEDNESDAY NIGHT. A COLD FRONT WILL APPROACH FROM THE WEST LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO LOWER 70S IN THE PIEDMONT. THE COLD FRONT WILL PUSH EAST ACROSS OUR AREA THURSDAY INTO THURSDAY NIGHT. AS HIGHLIGHTED IN SPC MARGINAL RISK...SOME STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE THURSDAY AFTERNOON AND EARLY EVENING. THE GREATEST THREAT WILL BE FOR PULSE SEVERE THUNDERSTORMS WITH DOWNBURST/LOCALIZED WIND DAMAGE POTENTIAL AS LOW-LEVEL LAPSE RATES STEEPEN THURSDAY AFTERNOON. THE SLIGHTLY STRONGER MID-LEVEL FLOW SHOULD REDUCE THE FLOOD POTENTIAL. HIGH TEMPERATURES THURSDAY WILL VARY FROM THE MID 70S IN THE NORTHWEST MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT. PLACED THE HIGHEST POPS IN THE EAST THURSDAY NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE LOWER 60S IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT. THE AMPLIFICATION OF THE SUBTROPICAL RIDGE INTO THE SOUTHWEST U.S. WILL RESULT IN STRENGTHENING NORTHWEST FLOW ALOFT ACROSS THE EAST COAST. THIS WILL PUSH THE COLD FRONT FURTHER SOUTH BEFORE STALLING IN SOUTHEAST LATE FRIDAY. COOLER HIGHS EXPECTED FRIDAY WITH READINGS FROM THE MID 70S IN THE NORTHWEST MOUNTAINS TO THE UPPER 80S IN THE PIEDMONT. LOWS TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE UPPER 50S IN THE WEST TO THE MID 60S IN THE EAST. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 PM EDT TUESDAY... A GOOD WEEKEND EXPECTED WITH DRY SEASONABLE TEMPERATURES AND HUMIDITY LEVELS...AS HIGH PRESSURE BUILD EAST OUT OF THE OHIO VALLEY. THERE ARE SEVERAL OTHER KEY PLAYERS IN THE MEDIUM RANGE FORECAST ESPECIALLY THE DEEPENING UPPER TROUGH AND PSEUDO-TROPICAL LOW. A BROAD UPPER TROUGH IS PROGGED TO REMAIN ACROSS EASTERN CANADA AND SHOULD DEEPEN INTO THE EASTERN UNITED STATES....THEN FLATTEN OUT EARLY NEXT WEEK. ANOTHER CONCERN FOR THIS PERIOD WILL BE AN AREA OF LOW PRESSURE WHICH DEVELOPS ACROSS FLORIDA OR IN THE GULF AND THE INTERACTION WITH STALLED FRONTAL BOUNDARY LOCATED ACROSS THE SOUTHEAST STATES. WITH RESPECT TO THE PSEUDO-TROPICAL LOW DEVELOPING ACROSS THE EASTERN GULF AND SOUTHEAST STATES...MODELS ARE IN BETTER AGREEMENT WITH THE UPPER TROUGH. THE ECMWF REMAINS THE MOST ROBUST COMPARED TO OTHER SOLUTIONS IN DEVELOPING A CLOSED SFC LOW...AND THEN TRACKING IT NORTHEAST ALONG THE SOUTHEAST COAST INTO EARLY NEXT WEEK. QUESTIONS REMAIN IN THE FORECAST ON WHETHER A WEAK FRONTAL BOUNDARY EARLY NEXT WEEK COULD PULL THE SOUTHEAST LOW PRESSURE CENTER AND ITS ASSOCIATED MOISTURE FURTHER INLAND ACROSS THE PIEDMONT OR BLOCK IT EAST OF THE AREA. IN ANY CASE...THE CHANCE FOR RAIN WILL BE INCREASING HEADING INTO EARLY NEXT WEEK. THE LOCATIONS WITH THE BETTER CHANCE OF RAIN WILL BE ACROSS THE PIEDMONT. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 725 PM EDT TUESDAY... SHOWERS AND THUNDERSTORMS WERE SCATTERED ACROSS THE REGION WITH THE GREATEST COVERAGE ALONG AND EAST OF A KMKJ...KROA...KHSP LINE. WITHIN THE STRONGER CELLS...LOCALIZED IFR/MVFR CONDITIONS EXISTED. WITHIN THE LIGHTER CELLS...AND OUTSIDE OF THE PRECIPITATION REGION...VFR CONDITIONS PREVAILED. AS WE HEAD INTO THE OVERNIGHT HOURS...THE COVERAGE OF SHOWERS AND STORMS WILL DECREASE...AND THE DEW POINT DEPRESSION WILL START TO LESSEN. THE RESULT WILL BE AN INCREASING COVERAGE OF SUB-VFR CONDITIONS...NOT BECAUSE OF PRECIPITATION...BUT BECAUSE OF THE FORMATION OF BR/FG AND STRATUS CLOUDS. ANTICIPATE MOST AREAS TO TREND TOWARD MVFR CONDITIONS OVERNIGHT...WITH SEVERAL LOCATIONS IN THE IFR...OR EVEN LIFR...RANGE BY EARLY WEDNESDAY MORNING. FLIGHT CATEGORIES WILL BE SLOW TO IMPROVE AFTER SUNRISE...BUT MOST LOCATIONS WILL BE VFR BY NOONTIME. IN THE AFTERNOON...ANOTHER ROUND OF SHOWERS AND SOME THUNDERSTORMS ARE EXPECTED. AGAIN...LOCALIZED MVFR/IFR CONDITIONS WILL BE POSSIBLE UNDER THE HEAVIER CELLS...WITH THE REMAINDER OF THE REGION STAYING IN VFR. EXTENDED AVIATION FORECAST... AS OF 1235 PM EDT TUESDAY... MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED ON THURSDAY AS A COLD FRONT CROSSES THROUGH REGION FROM THE NORTHWEST. THIS FRONT SHOULD PUSH SOUTH OF THE AREA AND ALLOW FOR DRIER AND MOSTLY VFR CONDITIONS FRIDAY THROUGH SUNDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/RAB NEAR TERM...DS/JH SHORT TERM...KK LONG TERM...KK AVIATION...DS/JH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
657 PM EDT TUE JUL 28 2015 .SYNOPSIS... A DIFFUSE FRONTAL BOUNDARY WILL LINGER ACROSS THE REGION THROUGH WEDNESDAY BEFORE ANOTHER STRONGER COLD FRONT ARRIVES FROM THE NORTHWEST THURSDAY. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE IN THE FORECAST UNTIL THE SECONDARY FRONT MOVES SOUTH OF THE REGION FRIDAY. SOMEWHAT DRIER AIR SHOULD FOLLOW THE FRONT FOR THE WEEKEND AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 650 PM EDT TUESDAY... A GENEROUS COVERAGE OF SHOWERS AND SOME SCATTERED STORMS ARE ACROSS THE REGION THIS EVENING. MOST OF THEM ARE ALONG AND EAST OF A HOT SPRINGS VIRGINIA...ROANOKE VIRGINIA...MARION VIRGINIA LINE. THE GREATEST CONCENTRATION IS BOUNDED INSIDE THE AREA TO THE RIGHT OF A ROANOKE VIRGINIA...HOT SPRINGS VIRGINIA...AMHERST VIRGINIA...BEDFORD VIRGINIA...ROANOKE VIRGINIA LINE. AS THE EVENING PROGRESSES...BOTH DIAGNOSTIC GUIDANCE AND MESO-SCALE MODELS SUGGEST A GENERAL TREND OF THE ACTIVITY PROGRESSING SLOWLY SOUTHEAST...AND DISSIPATING THROUGH THE LATE EVENING. BY EARLY WEDNESDAY MORNING...MAINLY ISOLATED SHOWERS ARE EXPECTED TO EXIST...WITH THE BULK OF THESE BETWEEN THE CREST OF THE BLUE RIDGE AND SOUTHSIDE VIRGINIA...AND NEIGHBORING PARTS OF NORTH CENTRAL NORTH CAROLINA. AS OF 205 PM EDT TUESDAY... CLUSTERS OF DEEPER CONVECTION CONTINUE OVER THE SE ALONG AN AXIS OF HIGHER SURFACE BASED THETA-E/INSTABILITY AND OVER THE NW IN ASSOCIATION WITH THE RESIDUAL FRONT AND A WEAK WAVE ALOFT. MODELS AGAIN STRUGGLING WITH WHERE TO PAINT THE BEST CONVECTIVE COVERAGE INTO TONIGHT GIVEN WEAK FEATURES AND DIURNAL NATURE OF MORE OUTFLOW DRIVEN STORMS. HOWEVER SOME CONSENSUS OFF THE HRRR AND ENSEMBLES AS WELL AS THE GFS TO HAVE BEST HEAVY RAIN PRODUCING SHRA/TSRA OVER THE EAST AS THE WEAK SHORTWAVE TO THE NW DROPS THROUGH THE REGION GIVEN LINGERING INSTABILITY WELL INTO THE EVENING. THIS AREA THOUGH MAY BE TOO WORKED OVER BY THEN SO WILL TREND WITH HIGHER POPS THERE AFTER SUNSET BUT MAINLY OF THE HIGH CHANCE VARIETY AS ADDED PRECIP AFTER DARK MAY BE VOID OF DEEP CONVECTION. OTRW KEEPING THE SCATTERED NATURE REGIME GOING THROUGH ABOUT MIDNIGHT WEST...AND PERIODS OF LIKELYS OR HIGHER OUT EAST A WHILE LONGER BEFORE CUTTING TO PC/FOG LATE. AGAIN QUITE WARM/MUGGY WITH MANY EASTERN LOCATIONS STAY ABOVE 70 UNLESS SPOTS SEE A COOLING SHOWER INTO THIS EVENING. 5H HEIGHTS WILL BUILD A BIT ON WEDNESDAY AS THE AREA REMAINS IN A MOISTURE LADEN ENVIRONMENT UNDER WEAK SURFACE HIGH PRESSURE BUT WITH LESS FOCUS GIVEN THE WASHING OUT OF THE NEARBY FRONT. GUIDANCE SHOWS SOME CONVERGENCE ACROSS THE RIDGES DURING THE AFTERNOON ESPCLY AS THE FLOW TURNS MORE SW ALOFT WHICH SHOULD HELP FOCUS ADDED CONVECTION ALONG THE RIDGES. HOWEVER WITH THE NEXT UPSTREAM SHORTWAVE TROUGH WELL TO THE NW WITH THE NEXT COLD FRONT...APPEARS LIFT WILL BE LESS BUT LIKELY ENOUGH GIVEN STRONG INSTABILITY TO RESULT IN SCATTERED COVERAGE MOUNTAINS AND A BIT LESS IN THE EAST. STEERING REMAINS ON THE WEAK SIDE SO MAIN THREAT AGAIN WITH HEAVY RAINFALL. HIGH TEMPS IN LINE WITH THE LATEST MAV/MOS MIX SO ONLY MADE SMALL TWEAKS TO BUMP UP VALUES A LITTLE IN THE EAST WHERE SOME LOW 90S POSSIBLE. OTRW MUGGY 80S IN STORE. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... AS OF 300 PM EDT TUESDAY... SCATTERED SHOWERS AND THUNDERSTORMS WILL DIMINISH WEDNESDAY EVENING INTO WEDNESDAY NIGHT. A COLD FRONT WILL APPROACH FROM THE WEST LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. LOW TEMPERATURES WEDNESDAY NIGHT WILL RANGE FROM THE MID 60S IN THE MOUNTAINS TO LOWER 70S IN THE PIEDMONT. THE COLD FRONT WILL PUSH EAST ACROSS OUR AREA THURSDAY INTO THURSDAY NIGHT. AS HIGHLIGHTED IN SPC MARGINAL RISK...SOME STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE THURSDAY AFTERNOON AND EARLY EVENING. THE GREATEST THREAT WILL BE FOR PULSE SEVERE THUNDERSTORMS WITH DOWNBURST/LOCALIZED WIND DAMAGE POTENTIAL AS LOW-LEVEL LAPSE RATES STEEPEN THURSDAY AFTERNOON. THE SLIGHTLY STRONGER MID-LEVEL FLOW SHOULD REDUCE THE FLOOD POTENTIAL. HIGH TEMPERATURES THURSDAY WILL VARY FROM THE MID 70S IN THE NORTHWEST MOUNTAINS TO THE LOWER 90S IN THE PIEDMONT. PLACED THE HIGHEST POPS IN THE EAST THURSDAY NIGHT. LOW TEMPERATURES THURSDAY NIGHT WILL DROP INTO THE LOWER 60S IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT. THE AMPLIFICATION OF THE SUBTROPICAL RIDGE INTO THE SOUTHWEST U.S. WILL RESULT IN STRENGTHENING NORTHWEST FLOW ALOFT ACROSS THE EAST COAST. THIS WILL PUSH THE COLD FRONT FURTHER SOUTH BEFORE STALLING IN SOUTHEAST LATE FRIDAY. COOLER HIGHS EXPECTED FRIDAY WITH READINGS FROM THE MID 70S IN THE NORTHWEST MOUNTAINS TO THE UPPER 80S IN THE PIEDMONT. LOWS TEMPERATURES FRIDAY NIGHT WILL VARY FROM THE UPPER 50S IN THE WEST TO THE MID 60S IN THE EAST. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 300 PM EDT TUESDAY... A GOOD WEEKEND EXPECTED WITH DRY SEASONABLE TEMPERATURES AND HUMIDITY LEVELS...AS HIGH PRESSURE BUILD EAST OUT OF THE OHIO VALLEY. THERE ARE SEVERAL OTHER KEY PLAYERS IN THE MEDIUM RANGE FORECAST ESPECIALLY THE DEEPENING UPPER TROUGH AND PSEUDO-TROPICAL LOW. A BROAD UPPER TROUGH IS PROGGED TO REMAIN ACROSS EASTERN CANADA AND SHOULD DEEPEN INTO THE EASTERN UNITED STATES....THEN FLATTEN OUT EARLY NEXT WEEK. ANOTHER CONCERN FOR THIS PERIOD WILL BE AN AREA OF LOW PRESSURE WHICH DEVELOPS ACROSS FLORIDA OR IN THE GULF AND THE INTERACTION WITH STALLED FRONTAL BOUNDARY LOCATED ACROSS THE SOUTHEAST STATES. WITH RESPECT TO THE PSEUDO-TROPICAL LOW DEVELOPING ACROSS THE EASTERN GULF AND SOUTHEAST STATES...MODELS ARE IN BETTER AGREEMENT WITH THE UPPER TROUGH. THE ECMWF REMAINS THE MOST ROBUST COMPARED TO OTHER SOLUTIONS IN DEVELOPING A CLOSED SFC LOW...AND THEN TRACKING IT NORTHEAST ALONG THE SOUTHEAST COAST INTO EARLY NEXT WEEK. QUESTIONS REMAIN IN THE FORECAST ON WHETHER A WEAK FRONTAL BOUNDARY EARLY NEXT WEEK COULD PULL THE SOUTHEAST LOW PRESSURE CENTER AND ITS ASSOCIATED MOISTURE FURTHER INLAND ACROSS THE PIEDMONT OR BLOCK IT EAST OF THE AREA. IN ANY CASE...THE CHANCE FOR RAIN WILL BE INCREASING HEADING INTO EARLY NEXT WEEK. THE LOCATIONS WITH THE BETTER CHANCE OF RAIN WILL BE ACROSS THE PIEDMONT. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 1235 PM EDT TUESDAY... OVERALL SHOTGUN PATTERN TO DEVELOPING CONVECTION WILL CONTINUE THROUGH MID AFTERNOON BEFORE PERHAPS SHRA/TSRA ORGANIZES A BIT MORE AND HEADS EAST OFF THE BLUE RIDGE. HOWEVER STILL TOO IFFY TO INCLUDE PREVAILING CONVECTION AT ANY ONE TAF SITE PENDING RELEASE SO KEEPING MOSTLY VCTS GOING AT MOST LOCATIONS INTO EARLY THIS EVENING. COULD BE ENOUGH COVERAGE THIS EVENING FOR MORE OF A PREVAILING MVFR GROUP IN SHOWERS OUT EAST BUT LOW CONFIDENCE. OTRW EXPECT MOST SITES TO FINALLY IMPROVE TO VFR LEVELS OUTSIDE OF CONVECTION EARLY THIS AFTERNOON WITH LOCALIZED MVFR/IFR IF A HEAVIER SLOW MOVING SHRA/TSRA MOVES OVER OR NEAR A TAF LOCATION DURING THE NEXT FEW HOURS. SHOWERS MAY LINGER WELL PAST MIDNIGHT TONIGHT ESPCLY IN THE EAST WITH A WEAK WAVE PASSING. THIS SHOULD GRADUALLY TREND TOWARD MORE FOG IN THE VALLEYS AND WHERE HEAVIER RAINFALL OCCURRED LATE. THIS SUPPORTS IFR/LIFR IN THE VALLEY SPOTS SUCH AS KLWB/KBCB AND OVERALL MVFR ELSW WITH EVEN SOME FOG POSSIBLE AT KROA IF THEY SEE AFTERNOON/EVENING RAINFALL. WEDNESDAY WILL BE ANOTHER DAY OF MVFR TO IFR VALLEY FOG IN THE MORNING AND SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. HOWEVER COVERAGE MAY BE LESS AND MORE OROGRAPHIC/OUTFLOW DRIVEN WEDNESDAY AFTERNOON WITH AGAIN LOCAL SUB-VFR IN AND NEAR ANY CONVECTION. EXTENDED AVIATION FORECAST... MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED ON THURSDAY AS A COLD FRONT CROSSES THROUGH REGION FROM THE NORTHWEST. THIS FRONT SHOULD PUSH SOUTH OF THE AREA AND ALLOW FOR DRIER AND MOSTLY VFR CONDITIONS FRIDAY THROUGH SUNDAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JH/RAB NEAR TERM...DS/JH SHORT TERM...KK LONG TERM...KK AVIATION...AMS/JH/MBS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
131 PM EDT MON JUL 27 2015 .SYNOPSIS... A WEAK COLD FRONT WILL DRIFT THROUGH THE REGION TODAY...THEN STALL JUST TO OUR SOUTH. THE FRONT WILL BE ACCOMPANIED BY SCATTERED SHOWERS AND THUNDERSTORMS. ANOTHER COLD FRONT WILL ARRIVE THURSDAY WITH THE NEXT BEST CHANCE FOR SHOWERS AND THUNDERSTORMS. WEAK HIGH PRESSURE AND MOSTLY DRY WEATHER IS EXPECTED BY THE WEEKEND. OTHERWISE...IT WILL REMAIN WARM AND HUMID FOR THE NEXT SEVERAL DAYS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 100 PM EDT MONDAY... A WEAK FRONT BOUNDARY HAS WASHED-OUT OVER THE SOUTHERN OHIO VALLEY. THIS BOUNDARY STILL SHOWING SOME CONVERGENCE TO INDUCE SHOWERS. THE MAIN CULPRIT FOR PRECIPITATION ACTIVITY TODAY STEMS FROM AN UPPER LEVEL RIDGE OVER THE SOUTHERN PLAINS. SHORT WAVES ON THE OUTER RINGS WILL TRACK ACROSS THE UPPER MIDWEST AND OVER THE REGION THROUGH TUESDAY. SHOWERS AND DEBRIS CLOUDS CAME IN EARLY THIS MORNING...LIMITING THE AREA FROM BECOMING TO UNSTABLE. THEREFORE THE SHOWERS COMING ACROSS THE REGION TODAY MAY NOT BECOME TO STRONG. HOWEVER...PWATS HAVE INCREASED TO AROUND AN INCH AND A HALF. A FEW STORMS THIS AFTERNOON COULD BECOME VERY EFFICIENT RAINFALL MAKERS AND COULD LEAD TO LOCALIZED FLOODING...ESPECIALLY IN LOW LYING AND POOR DRAINAGE AREA. BASED ON LATEST SATELLITE AND RADAR DATA...IT DOES NOT APPEAR THAT THE AREA WILL SEE A SIGNIFICANT AMOUNT OF SUN TODAY ACROSS THE MOUNTAINS. THEREFORE WE WILL KNOCK BACK TEMPERATURES A FEW DEGREES...ESPECIALLY ACROSS THE MOUNTAINS...PARTICULARLY SOUTHEAST WEST VIRGINIA AS OF 940 AM EDT MONDAY... PREFRONTAL SHOWERS WILL CONTINUE TO TRACK EAST FROM THE BLUEFIELD AREA TOWARD THE NEW RIVER AND ROANOKE VALLEYS THIS MORNING. AS THEY ARE MOVING EAST...THEY ARE LOSING SOME INTENSITY. THIS AREA OF SHOWERS WILL MOVES EAST OF THE BLUE RIDGE THIS AFTERNOON. IF THE SUN CAN POKE OUT BEFORE THEN...RE-INTENSIFICATION COULD BRING SOME STRONG STORMS TO THE PIEDMONT. AT THIS TIME...STRONG STORMS ARE NOT FORECASTED DUE TO THICK CLOUDS OVER THE PIEDMONT. CONVECTION ASSOCIATED WITH THE FRONT IN THE OHIO VALLEY WILL ENTER THE MOUNTAINS THIS AFTERNOON. THIS MORNING`S SHOWERS HAVE MOSTLY STABILIZED THE ENVIRONMENT AND ARE EXPECTED NOT TO BECOME STRONG THIS AFTERNOON. HOWEVER...LIKE THE PIEDMONT...IF THE SUN CAN SHINE THROUGH...DESTABILIZATION CAN OCCUR. AS OF 750 AM EDT MONDAY... SHOWERS AND THUNDERSTORMS HAVE INCREASED FAIRLY RAPIDLY ACROSS SOUTHERN WV AND FAR SOUTHWEST VA. THESE ARE A MOVING INTO THE BLF AREA...AND WILL LIKELY IMPACT LWB AND BCB BEFORE THE MORNING IS OVER. EXPECT BETTER COVERAGE OF SHOWERS AND STORMS FURTHER EAST BY AFTERNOON. HAVE INCREASED POPS THROUGH THE NEAR TERM IN ACCORDANCE WITH HRRR TRENDS...WHICH SEEMS TO HAVE A GOOD HANDLE ON CURRENT SITUATION. ONLY MINOR TWEAKS TO TEMPS/DEWPOINTS/CLOUD/QPF GRIDS AT THIS TIME. AS OF 400 AM EDT MONDAY... DIFFUSE FRONTAL BOUNDARY REMAINS TO OUR NORTH EARLY THIS MORNING AND SHOWERS CONTINUE TO DEVELOP ALONG IT AND SKIRT THE REGION TO THE NORTH. THE FRONT WILL SINK INTO THE REGION TODAY AND SERVE AS A FOCUS FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON...AIDED BY SHORT WAVE ENERGY STREAMING IN OUR DIRECTION IN NORTHWEST FLOW ALOFT FROM THE UPPER RIDGE OVER THE MIDSECTION OF THE COUNTRY. OVERALL DYNAMIC ENVIRONMENT REMAINS WEAK AND INSTABILITY IS MODEST AT BEST SO THE THREAT OF SEVERE STORMS CONTINUES TO BE LOW. THIS BEING SAID...ALL OF THE LATEST SYNOPTIC AND MESO MODEL GUIDANCE IS KEEN TO DEVELOPING SHOWERS AND THUNDERSTORMS THIS AFTERNOON WITH MORE EXPANSIVE SPATIAL COVERAGE THAN HAS OCCURRED IN RECENT DAYS. MOISTURE WILL ALSO BE INCREASING TODAY AS SEEN IN THE LOW LEVEL THETA/E FIELDS AND RISING PRECIPITABLE WATER VALUES. THIS WILL CONTINUE TO MAKE LOCALLY HEAVY DOWNPOURS A GOOD BET TO ACCOMPANY STORMS DURING THE AFTERNOON. EXPECTING A TYPICAL DIURNAL TREND TO CONVECTION SO ACTIVITY WILL BE DECLINING THIS EVENING WITH THE LOSS OF HEATING AFTER SUNSET. CURRENT SATELLITE IMAGES SHOW A GOOD DEAL OF MID CLOUDS MOVING OVER THE REGION. COMBINED WITH EXPECTED CONVECTIVE DEVELOPMENT AND ATTENDANT CLOUD COVER...WILL BUY INTO THE GUIDANCE TREND WHICH SHOWS READINGS A DEGREE OR TWO COOLER THAN WHAT OCCURRED ON SUNDAY...YIELDING READINGS AROUND 90 EAST OF THE BLUE RIDGE WITH LOW/MID 80S TO THE WEST. TONIGHT WILL BE MUGGY WITH SOME FOG DEVELOPING AND LOWS RANGING FROM THE LOWER 70S EAST TO MIDDLE 60S WEST. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 415 AM EDT MONDAY... THE WEAK COLD FRONT OF TODAY WILL LIE SOMEWHERE ACROSS THE SOUTH- SOUTHWEST PART OF THE BY TUE MORNING...BUT BECOMING VERY WEAK AND DIFFUSE AND DIFFICULT TO FIND IN THE MODELS. HOWEVER...IT WILL LIKELY REMAIN AS ENOUGH OF A CONVERGENCE ZONE TO SERVE AS A FOCUSING MECHANISM FOR DIURNAL SHOWERS AND THUNDERSTORMS. A STRONG SUBTROPICAL RIDGE WILL REMAIN ANCHORED ACROSS THE CENTRAL U.S. THROUGH TUE...WITH 590DM+ HEIGHTS ALOFT AND WARM 500MB TEMPS. THIS WILL CONTINUE TO PUT A LID ON ANY WIDESPREAD CONVECTION. THE COMBINATION OF THE DIFFUSE FRONTAL BOUNDARY AND DIFFERENTIAL HEATING ACROSS THE MOUNTAINS SHOULD FOCUS THE BEST CHANCE OF CONVECTION ACROSS THE MOUNTAINS OF SOUTHWEST VA AND NORTHWEST NC INTO THE SOUTHERN PARTS OF THE PIEDMONT COUNTIES IN THE CWA. CONVECTION SHOULD DIMINISH QUICKLY AFTER SUNSET TUESDAY. FOR WED...THE FRONTAL BOUNDARY CONTINUES TO WASH OUT ACROSS THE REGION...PERHAPS LINGERING ACROSS SW VA/NW NC...WHICH MAY AGAIN SERVE AS A WEAK FOCUS FOR DIURNAL CONVECTION. THE STRONG SUBTROPICAL RIDGE IN THE CENTRAL U.S. BEINGS TO RETROGRADE INTO THE SOUTHWEST U.S. AS LOW PRESSURE ALOFT MOVES EASTWARD ALONG THE U.S./CANADIAN BORDER. THIS WILL DRIVE THE NEXT FRONT INTO OUR REGION FROM THE NORTHWEST WEDNESDAY NIGHT INTO THURSDAY. OVERALL...CONVECTION SHOULD BE AT A MINIMUM WEDNESDAY...BUT AS NOTED...THERE IS A SLIGHT CHANCE TO LOW END CHANCE ACROSS MUCH OF THE CWA...FAVORING AREAS WEST OF I-77. LATE WED NIGHT OR EARLY THU...DIMINISHING CONVECTION COULD REACH THE WESTERN BORDER OF THE CWA IF EXPECTED THUNDERSTORMS FROM THE OH VALLEY HOLD TOGETHER THAT LONG. THU SHOULD IN THEORY BRING THE BEST CHANCE FOR WIDESPREAD CONVECTION TO THE CWA ASSOCIATED WITH THE COLD FRONT. INSTABILITY WILL BE MAXIMIZED. HOWEVER...TIMING OF THE FRONTAL BOUNDARY INTO THE REGION THU MORNING AND THE POTENTIAL FOR MORNING CLOUD DEBRIS AND LIGHT SHOWERS COULD INHIBIT MORE ROBUST CONVECTION LATER IN THE DAY. LATEST MODEL TRENDS HAVE BEEN TO DECREASE THE THREAT FOR WIDESPREAD CONVECTION THURSDAY. WHAT THERE IS MAY BE FOCUSED MOSTLY EAST OF THE BLUE RIDGE DURING THE AFTERNOON WHERE HEATING WILL BE BETTER WITH LESS MORNING CLOUD COVER AND WHERE THE FRONT IS ALSO EXPECTED TO BE LOCATED BY AFTERNOON. FOR ALL THREE DAYS AT THIS POINT...NO MORE THAN CHANCE POPS WARRANTED AT THIS TIME. TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE PERIOD...ESPECIALLY LOW TEMPS WITH DEWPOINTS HOVERING IN THE 65 TO 70 RANGE ACROSS MOST OF THE CWA. WEDNESDAY SHOULD BE THE WARMEST DAY OVERALL BETWEEN WEATHER SYSTEMS...WITH 850MB TEMPS HOVERING AROUND +20C...SOUTHWEST SFC WINDS...AND PRE-FRONTAL CONDITIONS. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 445 AM EDT MONDAY... MODELS HAVE TRENDED MUCH DRIER IN THE EXTENDED PERIODS THAN NOTED THE PAST FEW DAYS AND OVERALL ARE IN FAIRLY GOOD AGREEMENT ON THIS SCENARIO. THE UPPER TROUGH ACROSS THE NORTHEAST U.S. BECOMES DEEP ENOUGH AS THE SUBTROPICAL RIDGE SHIFTS WEST INTO THE CA/AZ REGION...TO PUSH THE FRONTAL BOUNDARY SOUTH INTO THE SOUTHEAST STATES BEFORE IT STALLS. CONSEQUENTLY...ANY SUBSEQUENT LOW PRESSURE OR TROPICAL LOW PRESSURE DEVELOPMENT WILL REMAIN WELL SOUTH OF THE REGION RIDING ALONG THE FRONTAL BOUNDARY. AT THIS TIME...IT DOES NOT APPEAR THAT THIS MOISTURE WILL TRACK FAR ENOUGH NORTH TO IMPACT ANY OF OUR REGION. IT WILL BE INTERESTING TO SEE IF THE MODELS STICK WITH THIS LATEST TREND. DEWPOINTS DROP INTO THE 50S ACROSS THE MOUNTAINS AND 60S PIEDMONT FRI- SUN...WITH INDICATED INSTABILITY AT A MINIMUM...ACTUALLY QUITE STABLE FOR LATE JULY INTO EARLY AUGUST. BY MONDAY...THE UPPER TROUGH ACROSS THE GREAT LAKES DEEPENS AS SHORT WAVE ENERGY TRACKS THROUGH THE BASE OF THE TROUGH. THIS WILL PUSH THE NEXT COLD FRONT INTO THE AREA AND ITS ASSOCIATED PRECIPITATION. MAX/MIN TEMPERATURES SHOULD TREND CLOSER TO NORMAL DURING THIS PERIOD AS DEWPOINTS DROP. WE SHOULD SEE HIGHS IN THE 70S ACROSS THE MOUNTAINS AND 80S ELSEWHERE...WITH LOWS MOSTLY IN THE 60S. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 130 PM EDT MONDAY... AREAS OF RAIN THIS MORNING IS BECOMING MORE CELLULAR EARLY THIS AFTERNOON. WE WILL LIKELY SEE AN INCREASE IN THUNDER/LIGHTNING WITHIN SCATTERED STORMS MOVING ACROSS NORTHWEST NORTH CAROLINA. CLOUDS SHOWING BREAKS ACROSS THE PIEDMONT AND WITH BOUNDARIES ACROSS THE EAST...LATE AFTERNOON THUNDERSTORMS ARE POSSIBLE. WILL MAINTAIN VFR CONDITIONS AT ALL SITES AND WITH SPOTTY NATURE OF STORMS...WILL ONLY HAVE VICINITY SHOWERS. LINGERING SHOWERS ARE POSSIBLE OVERNIGHT ALONG WITH PATCHY VALLEY FOG. EXTENDED AVIATION FORECAST... MODELS APPEAR IN DECENT AGREEMENT THAT THE COLD FRONT WILL STALL JUST SOUTH OF THE FORECAST AREA...BEFORE RETREATING BACK TO THE NORTH ON TUESDAY. EXPECT MAINLY VFR CONDITIONS THROUGH THE WORKWEEK OUTSIDE OF SCATTERED CONVECTION EACH AFTERNOON/ EVENING...AND LOCALIZED FOG/STRATUS EARLY EACH MORNING. SHOWER AND THUNDERSTORM CHANCES THURSDAY AS A NEW COLD FRONT MOVES INTO THE REGION FROM THE NORTHWEST. THIS FRONT SHOULD PUSH SOUTH OF THE AREA AND ALLOW FOR DRIER AND MOSTLY VFR CONDITIONS FRI-SAT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...RAB NEAR TERM...MBS/RCS SHORT TERM...RAB LONG TERM...RAB/WP AVIATION...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
954 AM EDT MON JUL 27 2015 .SYNOPSIS... A WEAK COLD FRONT WILL DRIFT THROUGH THE REGION TODAY...THEN STALL JUST TO OUR SOUTH. THE FRONT WILL BE ACCOMPANIED BY SCATTERED SHOWERS AND THUNDERSTORMS. ANOTHER COLD FRONT WILL ARRIVE THURSDAY WITH THE NEXT BEST CHANCE FOR SHOWERS AND THUNDERSTORMS. WEAK HIGH PRESSURE AND MOSTLY DRY WEATHER IS EXPECTED BY THE WEEKEND. OTHERWISE...IT WILL REMAIN WARM AND HUMID FOR THE NEXT SEVERAL DAYS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 940 AM EDT MONDAY... PREFRONTAL SHOWERS WILL CONTINUE TO TRACK EAST FROM THE BLUEFIELD AREA TOWARD THE NEW RIVER AND ROANOKE VALLEYS THIS MORNING. AS THEY ARE MOVING EAST...THEY ARE LOSING SOME INTENSITY. THIS AREA OF SHOWERS WILL MOVES EAST OF THE BLUE RIDGE THIS AFTERNOON. IF THE SUN CAN POKE OUT BEFORE THEN...RE-INTENSIFICATION COULD BRING SOME STRONG STORMS TO THE PIEDMONT. AT THIS TIME...STRONG STORMS ARE NOT FORECASTED DUE TO THICK CLOUDS OVER THE PIEDMONT. CONVECTION ASSOCIATED WITH THE FRONT IN THE OHIO VALLEY WILL ENTER THE MOUNTAINS THIS AFTERNOON. THIS MORNING`S SHOWERS HAVE MOSTLY STABILIZED THE ENVIRONMENT AND ARE EXPECTED NOT TO BECOME STRONG THIS AFTERNOON. HOWEVER...LIKE THE PIEDMONT...IF THE SUN CAN SHINE THROUGH...DESTABILIZATION CAN OCCUR. AS OF 750 AM EDT MONDAY... SHOWERS AND THUNDERSTORMS HAVE INCREASED FAIRLY RAPIDLY ACROSS SOUTHERN WV AND FAR SOUTHWEST VA. THESE ARE A MOVING INTO THE BLF AREA...AND WILL LIKELY IMPACT LWB AND BCB BEFORE THE MORNING IS OVER. EXPECT BETTER COVERAGE OF SHOWERS AND STORMS FURTHER EAST BY AFTERNOON. HAVE INCREASED POPS THROUGH THE NEAR TERM IN ACCORDANCE WITH HRRR TRENDS...WHICH SEEMS TO HAVE A GOOD HANDLE ON CURRENT SITUATION. ONLY MINOR TWEAKS TO TEMPS/DEWPOINTS/CLOUD/QPF GRIDS AT THIS TIME. AS OF 400 AM EDT MONDAY... DIFFUSE FRONTAL BOUNDARY REMAINS TO OUR NORTH EARLY THIS MORNING AND SHOWERS CONTINUE TO DEVELOP ALONG IT AND SKIRT THE REGION TO THE NORTH. THE FRONT WILL SINK INTO THE REGION TODAY AND SERVE AS A FOCUS FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON...AIDED BY SHORT WAVE ENERGY STREAMING IN OUR DIRECTION IN NORTHWEST FLOW ALOFT FROM THE UPPER RIDGE OVER THE MIDSECTION OF THE COUNTRY. OVERALL DYNAMIC ENVIRONMENT REMAINS WEAK AND INSTABILITY IS MODEST AT BEST SO THE THREAT OF SEVERE STORMS CONTINUES TO BE LOW. THIS BEING SAID...ALL OF THE LATEST SYNOPTIC AND MESO MODEL GUIDANCE IS KEEN TO DEVELOPING SHOWERS AND THUNDERSTORMS THIS AFTERNOON WITH MORE EXPANSIVE SPATIAL COVERAGE THAN HAS OCCURRED IN RECENT DAYS. MOISTURE WILL ALSO BE INCREASING TODAY AS SEEN IN THE LOW LEVEL THETA/E FIELDS AND RISING PRECIPITABLE WATER VALUES. THIS WILL CONTINUE TO MAKE LOCALLY HEAVY DOWNPOURS A GOOD BET TO ACCOMPANY STORMS DURING THE AFTERNOON. EXPECTING A TYPICAL DIURNAL TREND TO CONVECTION SO ACTIVITY WILL BE DECLINING THIS EVENING WITH THE LOSS OF HEATING AFTER SUNSET. CURRENT SATELLITE IMAGES SHOW A GOOD DEAL OF MID CLOUDS MOVING OVER THE REGION. COMBINED WITH EXPECTED CONVECTIVE DEVELOPMENT AND ATTENDANT CLOUD COVER...WILL BUY INTO THE GUIDANCE TREND WHICH SHOWS READINGS A DEGREE OR TWO COOLER THAN WHAT OCCURRED ON SUNDAY...YIELDING READINGS AROUND 90 EAST OF THE BLUE RIDGE WITH LOW/MID 80S TO THE WEST. TONIGHT WILL BE MUGGY WITH SOME FOG DEVELOPING AND LOWS RANGING FROM THE LOWER 70S EAST TO MIDDLE 60S WEST. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 415 AM EDT MONDAY... THE WEAK COLD FRONT OF TODAY WILL LIE SOMEWHERE ACROSS THE SOUTH- SOUTHWEST PART OF THE BY TUE MORNING...BUT BECOMING VERY WEAK AND DIFFUSE AND DIFFICULT TO FIND IN THE MODELS. HOWEVER...IT WILL LIKELY REMAIN AS ENOUGH OF A CONVERGENCE ZONE TO SERVE AS A FOCUSING MECHANISM FOR DIURNAL SHOWERS AND THUNDERSTORMS. A STRONG SUBTROPICAL RIDGE WILL REMAIN ANCHORED ACROSS THE CENTRAL U.S. THROUGH TUE...WITH 590DM+ HEIGHTS ALOFT AND WARM 500MB TEMPS. THIS WILL CONTINUE TO PUT A LID ON ANY WIDESPREAD CONVECTION. THE COMBINATION OF THE DIFFUSE FRONTAL BOUNDARY AND DIFFERENTIAL HEATING ACROSS THE MOUNTAINS SHOULD FOCUS THE BEST CHANCE OF CONVECTION ACROSS THE MOUNTAINS OF SOUTHWEST VA AND NORTHWEST NC INTO THE SOUTHERN PARTS OF THE PIEDMONT COUNTIES IN THE CWA. CONVECTION SHOULD DIMINISH QUICKLY AFTER SUNSET TUESDAY. FOR WED...THE FRONTAL BOUNDARY CONTINUES TO WASH OUT ACROSS THE REGION...PERHAPS LINGERING ACROSS SW VA/NW NC...WHICH MAY AGAIN SERVE AS A WEAK FOCUS FOR DIURNAL CONVECTION. THE STRONG SUBTROPICAL RIDGE IN THE CENTRAL U.S. BEINGS TO RETROGRADE INTO THE SOUTHWEST U.S. AS LOW PRESSURE ALOFT MOVES EASTWARD ALONG THE U.S./CANADIAN BORDER. THIS WILL DRIVE THE NEXT FRONT INTO OUR REGION FROM THE NORTHWEST WEDNESDAY NIGHT INTO THURSDAY. OVERALL...CONVECTION SHOULD BE AT A MINIMUM WEDNESDAY...BUT AS NOTED...THERE IS A SLIGHT CHANCE TO LOW END CHANCE ACROSS MUCH OF THE CWA...FAVORING AREAS WEST OF I-77. LATE WED NIGHT OR EARLY THU...DIMINISHING CONVECTION COULD REACH THE WESTERN BORDER OF THE CWA IF EXPECTED THUNDERSTORMS FROM THE OH VALLEY HOLD TOGETHER THAT LONG. THU SHOULD IN THEORY BRING THE BEST CHANCE FOR WIDESPREAD CONVECTION TO THE CWA ASSOCIATED WITH THE COLD FRONT. INSTABILITY WILL BE MAXIMIZED. HOWEVER...TIMING OF THE FRONTAL BOUNDARY INTO THE REGION THU MORNING AND THE POTENTIAL FOR MORNING CLOUD DEBRIS AND LIGHT SHOWERS COULD INHIBIT MORE ROBUST CONVECTION LATER IN THE DAY. LATEST MODEL TRENDS HAVE BEEN TO DECREASE THE THREAT FOR WIDESPREAD CONVECTION THURSDAY. WHAT THERE IS MAY BE FOCUSED MOSTLY EAST OF THE BLUE RIDGE DURING THE AFTERNOON WHERE HEATING WILL BE BETTER WITH LESS MORNING CLOUD COVER AND WHERE THE FRONT IS ALSO EXPECTED TO BE LOCATED BY AFTERNOON. FOR ALL THREE DAYS AT THIS POINT...NO MORE THAN CHANCE POPS WARRANTED AT THIS TIME. TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE PERIOD...ESPECIALLY LOW TEMPS WITH DEWPOINTS HOVERING IN THE 65 TO 70 RANGE ACROSS MOST OF THE CWA. WEDNESDAY SHOULD BE THE WARMEST DAY OVERALL BETWEEN WEATHER SYSTEMS...WITH 850MB TEMPS HOVERING AROUND +20C...SOUTHWEST SFC WINDS...AND PRE-FRONTAL CONDITIONS. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 445 AM EDT MONDAY... MODELS HAVE TRENDED MUCH DRIER IN THE EXTENDED PERIODS THAN NOTED THE PAST FEW DAYS AND OVERALL ARE IN FAIRLY GOOD AGREEMENT ON THIS SCENARIO. THE UPPER TROUGH ACROSS THE NORTHEAST U.S. BECOMES DEEP ENOUGH AS THE SUBTROPICAL RIDGE SHIFTS WEST INTO THE CA/AZ REGION...TO PUSH THE FRONTAL BOUNDARY SOUTH INTO THE SOUTHEAST STATES BEFORE IT STALLS. CONSEQUENTLY...ANY SUBSEQUENT LOW PRESSURE OR TROPICAL LOW PRESSURE DEVELOPMENT WILL REMAIN WELL SOUTH OF THE REGION RIDING ALONG THE FRONTAL BOUNDARY. AT THIS TIME...IT DOES NOT APPEAR THAT THIS MOISTURE WILL TRACK FAR ENOUGH NORTH TO IMPACT ANY OF OUR REGION. IT WILL BE INTERESTING TO SEE IF THE MODELS STICK WITH THIS LATEST TREND. DEWPOINTS DROP INTO THE 50S ACROSS THE MOUNTAINS AND 60S PIEDMONT FRI- SUN...WITH INDICATED INSTABILITY AT A MINIMUM...ACTUALLY QUITE STABLE FOR LATE JULY INTO EARLY AUGUST. BY MONDAY...THE UPPER TROUGH ACROSS THE GREAT LAKES DEEPENS AS SHORT WAVE ENERGY TRACKS THROUGH THE BASE OF THE TROUGH. THIS WILL PUSH THE NEXT COLD FRONT INTO THE AREA AND ITS ASSOCIATED PRECIPITATION. MAX/MIN TEMPERATURES SHOULD TREND CLOSER TO NORMAL DURING THIS PERIOD AS DEWPOINTS DROP. WE SHOULD SEE HIGHS IN THE 70S ACROSS THE MOUNTAINS AND 80S ELSEWHERE...WITH LOWS MOSTLY IN THE 60S. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... AS OF 745 AM EDT MONDAY... AREA OF SHOWERS AND THUNDERSTORMS ALREADY MOVING INTO THE SOUTHWEST PART OF THE CWA AND WILL LIKELY IMPACT BLF...AND POSSIBLY LWB AND BCB WITHIN THE NEXT FEW HOURS. A FEW LIGHTNING STRIKES AND POCKETS OF VERY HEAVY RAINFALL. COULD BE A PERIOD OF MVFR CIGS/VSBYS AT BLF/LWB/BCB THROUGH 15Z AS A RESULT. MOST MODELS AGRESSIVE WITH CONVECTION THIS AFTERNOON...AND IF CURRENT TREND IS A SIGN OF THINGS TO COME...MODELS MAY BE ON THE RIGHT TRACK. FOCUS WILL BE ON A WEAK FRONTAL BOUNDARY AND A FAIRLY HEALTHY SHORT WAVE TRACKING ESE FROM THE OH VALLEY...SLATED TO ARRIVE DURING THE AFTERNOON. MORNING ACTIVITY MAY DICTATE WHERE AFTERNOON ACTIVITY FORMS...WHICH COULD AT THAT POINT BE MAINLY EAST OF THE BLUE RIDGE. HAVE RETAINED VCTS IN ALL TAFS AS IN THE 06Z SET...BUT HAVE NOT IDENTIFIED ANY TEMPO OR PROB30 GROUPS FOR SPECIFIC PERIODS OF MORE LIKELY TSRA AT THIS POINT. AGAIN...CONVECTION MAY BE ACCOMPANIED BY MVFR-IFR CIGS/VSBYS...BUT TIMING NOT CERTAIN. OUTSIDE CONVECTION...WHICH MAY LINGER INTO THE EVENING HOURS...BUT SHOULD BE DONE BY 04Z...MOIST GROUND AND LOWER ATMOSPHERE SHOULD ALLOW FOR BETTER DEVELOPMENT OF RADIATIONAL FOG. HOWEVER...PERSISTENT MID-LEVEL DECK MAY TEND TO INHIBIT FOG DEVELOPMENT. HAVE ADVERTISED MVFR-IFR BR AT MOST TAF SITES...WITH LIFR AT LWB WHERE WET GROUND AND CALM WINDS SHOULD ALLOW FOR BETTER FOG DEVELOPMENT IN THE GREENBRIER VALLEY. WINDS THROUGH THE TAF PERIOD WILL BE MOSTLY LIGHT AND VARIABLE...BUT WILL TEND TO LEAN TOWARD THE SSE EAST OF THE BLUE RIDGE...AND SSW WEST OF THE BLUE RIDGE. SPEEDS 5KTS OR LESS THROUGH THE TAF VALID PERIOD...EXCEPT IN AND NEAR THUNDERSTORMS. MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND SPEED THROUGH THE TAF VALID PERIOD. LOW CONFIDENCE IN WIND DIRECTION THROUGH THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN THUNDERSTORM POTENTIAL THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION FORECAST... MODELS APPEAR IN DECENT AGREEMENT THAT THE COLD FRONT WILL STALL JUST SOUTH OF THE FORECAST AREA...BEFORE RETREATING BACK TO THE NORTH ON TUESDAY. EXPECT MAINLY VFR CONDITIONS THROUGH THE WORKWEEK OUTSIDE OF SCATTERED CONVECTION EACH AFTERNOON/ EVENING...AND LOCALIZED FOG/STRATUS EARLY EACH MORNING. SHOWER AND THUNDERSTORM CHANCES THURSDAY AS A NEW COLD FRONT MOVES INTO THE REGION FROM THE NORTHWEST. THIS FRONT SHOULD PUSH SOUTH OF THE AREA AND ALLOW FOR DRIER AND MOSTLY VFR CONDITIONS FRI-SAT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...RAB NEAR TERM...MBS/RCS SHORT TERM...RAB LONG TERM...RAB/WP AVIATION...MBS/NF/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
752 AM EDT MON JUL 27 2015 .SYNOPSIS... A WEAK COLD FRONT WILL DRIFT THROUGH THE REGION TODAY...THEN STALL JUST TO OUR SOUTH. THE FRONT WILL BE ACCOMPANIED BY SCATTERED SHOWERS AND THUNDERSTORMS. ANOTHER COLD FRONT WILL ARRIVE THURSDAY WITH THE NEXT BEST CHANCE FOR SHOWERS AND THUNDERSTORMS. WEAK HIGH PRESSURE AND MOSTLY DRY WEATHER IS EXPECTED BY THE WEEKEND. OTHERWISE...IT WILL REMAIN WARM AND HUMID FOR THE NEXT SEVERAL DAYS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 750 AM EDT MONDAY... SHOWERS AND THUNDERSTORMS HAVE INCREASED FAIRLY RAPIDLY ACROSS SOUTHERN WV AND FAR SOUTHWEST VA. THESE ARE A MOVING INTO THE BLF AREA...AND WILL LIKELY IMPACT LWB AND BCB BEFORE THE MORNING IS OVER. EXPECT BETTER COVERAGE OF SHOWERS AND STORMS FURTHER EAST BY AFTERNOON. HAVE INCREASED POPS THROUGH THE NEAR TERM IN ACCORDANCE WITH HRRR TRENDS...WHICH SEEMS TO HAVE A GOOD HANDLE ON CURRENT SITUATION. ONLY MINOR TWEAKS TO TEMPS/DEWPOINTS/CLOUD/QPF GRIDS AT THIS TIME. AS OF 400 AM EDT MONDAY... DIFFUSE FRONTAL BOUNDARY REMAINS TO OUR NORTH EARLY THIS MORNING AND SHOWERS CONTINUE TO DEVELOP ALONG IT AND SKIRT THE REGION TO THE NORTH. THE FRONT WILL SINK INTO THE REGION TODAY AND SERVE AS A FOCUS FOR CONVECTIVE DEVELOPMENT THIS AFTERNOON...AIDED BY SHORT WAVE ENERGY STREAMING IN OUR DIRECTION IN NORTHWEST FLOW ALOFT FROM THE UPPER RIDGE OVER THE MIDSECTION OF THE COUNTRY. OVERALL DYNAMIC ENVIRONMENT REMAINS WEAK AND INSTABILITY IS MODEST AT BEST SO THE THREAT OF SEVERE STORMS CONTINUES TO BE LOW. THIS BEING SAID...ALL OF THE LATEST SYNOPTIC AND MESO MODEL GUIDANCE IS KEEN TO DEVELOPING SHOWERS AND THUNDERSTORMS THIS AFTERNOON WITH MORE EXPANSIVE SPATIAL COVERAGE THAN HAS OCCURRED IN RECENT DAYS. MOISTURE WILL ALSO BE INCREASING TODAY AS SEEN IN THE LOW LEVEL THETA/E FIELDS AND RISING PRECIPITABLE WATER VALUES. THIS WILL CONTINUE TO MAKE LOCALLY HEAVY DOWNPOURS A GOOD BET TO ACCOMPANY STORMS DURING THE AFTERNOON. EXPECTING A TYPICAL DIURNAL TREND TO CONVECTION SO ACTIVITY WILL BE DECLINING THIS EVENING WITH THE LOSS OF HEATING AFTER SUNSET. CURRENT SATELLITE IMAGES SHOW A GOOD DEAL OF MID CLOUDS MOVING OVER THE REGION. COMBINED WITH EXPECTED CONVECTIVE DEVELOPMENT AND ATTENDANT CLOUD COVER...WILL BUY INTO THE GUIDANCE TREND WHICH SHOWS READINGS A DEGREE OR TWO COOLER THAN WHAT OCCURRED ON SUNDAY...YIELDING READINGS AROUND 90 EAST OF THE BLUE RIDGE WITH LOW/MID 80S TO THE WEST. TONIGHT WILL BE MUGGY WITH SOME FOG DEVELOPING AND LOWS RANGING FROM THE LOWER 70S EAST TO MIDDLE 60S WEST. && .SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/... AS OF 415 AM EDT MONDAY... THE WEAK COLD FRONT OF TODAY WILL LIE SOMEWHERE ACROSS THE SOUTH- SOUTHWEST PART OF THE BY TUE MORNING...BUT BECOMING VERY WEAK AND DIFFUSE AND DIFFICULT TO FIND IN THE MODELS. HOWEVER...IT WILL LIKELY REMAIN AS ENOUGH OF A CONVERGENCE ZONE TO SERVE AS A FOCUSING MECHANISM FOR DIURNAL SHOWERS AND THUNDERSTORMS. A STRONG SUBTROPICAL RIDGE WILL REMAIN ANCHORED ACROSS THE CENTRAL U.S. THROUGH TUE...WITH 590DM+ HEIGHTS ALOFT AND WARM 500MB TEMPS. THIS WILL CONTINUE TO PUT A LID ON ANY WIDESPREAD CONVECTION. THE COMBINATION OF THE DIFFUSE FRONTAL BOUNDARY AND DIFFERENTIAL HEATING ACROSS THE MOUNTAINS SHOULD FOCUS THE BEST CHANCE OF CONVECTION ACROSS THE MOUNTAINS OF SOUTHWEST VA AND NORTHWEST NC INTO THE SOUTHERN PARTS OF THE PIEDMONT COUNTIES IN THE CWA. CONVECTION SHOULD DIMINISH QUICKLY AFTER SUNSET TUESDAY. FOR WED...THE FRONTAL BOUNDARY CONTINUES TO WASH OUT ACROSS THE REGION...PERHAPS LINGERING ACROSS SW VA/NW NC...WHICH MAY AGAIN SERVE AS A WEAK FOCUS FOR DIURNAL CONVECTION. THE STRONG SUBTROPICAL RIDGE IN THE CENTRAL U.S. BEINGS TO RETROGRADE INTO THE SOUTHWEST U.S. AS LOW PRESSURE ALOFT MOVES EASTWARD ALONG THE U.S./CANADIAN BORDER. THIS WILL DRIVE THE NEXT FRONT INTO OUR REGION FROM THE NORTHWEST WEDNESDAY NIGHT INTO THURSDAY. OVERALL...CONVECTION SHOULD BE AT A MINIMUM WEDNESDAY...BUT AS NOTED...THERE IS A SLIGHT CHANCE TO LOW END CHANCE ACROSS MUCH OF THE CWA...FAVORING AREAS WEST OF I-77. LATE WED NIGHT OR EARLY THU...DIMINISHING CONVECTION COULD REACH THE WESTERN BORDER OF THE CWA IF EXPECTED THUNDERSTORMS FROM THE OH VALLEY HOLD TOGETHER THAT LONG. THU SHOULD IN THEORY BRING THE BEST CHANCE FOR WIDESPREAD CONVECTION TO THE CWA ASSOCIATED WITH THE COLD FRONT. INSTABILITY WILL BE MAXIMIZED. HOWEVER...TIMING OF THE FRONTAL BOUNDARY INTO THE REGION THU MORNING AND THE POTENTIAL FOR MORNING CLOUD DEBRIS AND LIGHT SHOWERS COULD INHIBIT MORE ROBUST CONVECTION LATER IN THE DAY. LATEST MODEL TRENDS HAVE BEEN TO DECREASE THE THREAT FOR WIDESPREAD CONVECTION THURSDAY. WHAT THERE IS MAY BE FOCUSED MOSTLY EAST OF THE BLUE RIDGE DURING THE AFTERNOON WHERE HEATING WILL BE BETTER WITH LESS MORNING CLOUD COVER AND WHERE THE FRONT IS ALSO EXPECTED TO BE LOCATED BY AFTERNOON. FOR ALL THREE DAYS AT THIS POINT...NO MORE THAN CHANCE POPS WARRANTED AT THIS TIME. TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE PERIOD...ESPECIALLY LOW TEMPS WITH DEWPOINTS HOVERING IN THE 65 TO 70 RANGE ACROSS MOST OF THE CWA. WEDNESDAY SHOULD BE THE WARMEST DAY OVERALL BETWEEN WEATHER SYSTEMS...WITH 850MB TEMPS HOVERING AROUND +20C...SOUTHWEST SFC WINDS...AND PRE-FRONTAL CONDITIONS. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 445 AM EDT MONDAY... MODELS HAVE TRENDED MUCH DRIER IN THE EXTENDED PERIODS THAN NOTED THE PAST FEW DAYS AND OVERALL ARE IN FAIRLY GOOD AGREEMENT ON THIS SCENARIO. THE UPPER TROUGH ACROSS THE NORTHEAST U.S. BECOMES DEEP ENOUGH AS THE SUBTROPICAL RIDGE SHIFTS WEST INTO THE CA/AZ REGION...TO PUSH THE FRONTAL BOUNDARY SOUTH INTO THE SOUTHEAST STATES BEFORE IT STALLS. CONSEQUENTLY...ANY SUBSEQUENT LOW PRESSURE OR TROPICAL LOW PRESSURE DEVELOPMENT WILL REMAIN WELL SOUTH OF THE REGION RIDING ALONG THE FRONTAL BOUNDARY. AT THIS TIME...IT DOES NOT APPEAR THAT THIS MOISTURE WILL TRACK FAR ENOUGH NORTH TO IMPACT ANY OF OUR REGION. IT WILL BE INTERESTING TO SEE IF THE MODELS STICK WITH THIS LATEST TREND. DEWPOINTS DROP INTO THE 50S ACROSS THE MOUNTAINS AND 60S PIEDMONT FRI- SUN...WITH INDICATED INSTABILITY AT A MINIMUM...ACTUALLY QUITE STABLE FOR LATE JULY INTO EARLY AUGUST. BY MONDAY...THE UPPER TROUGH ACROSS THE GREAT LAKES DEEPENS AS SHORT WAVE ENERGY TRACKS THROUGH THE BASE OF THE TROUGH. THIS WILL PUSH THE NEXT COLD FRONT INTO THE AREA AND ITS ASSOCIATED PRECIPITATION. MAX/MIN TEMPERATURES SHOULD TREND CLOSER TO NORMAL DURING THIS PERIOD AS DEWPOINTS DROP. WE SHOULD SEE HIGHS IN THE 70S ACROSS THE MOUNTAINS AND 80S ELSEWHERE...WITH LOWS MOSTLY IN THE 60S. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 745 AM EDT MONDAY... AREA OF SHOWERS AND THUNDERSTORMS ALREADY MOVING INTO THE SOUTHWEST PART OF THE CWA AND WILL LIKELY IMPACT BLF...AND POSSIBLY LWB AND BCB WITHIN THE NEXT FEW HOURS. A FEW LIGHTNING STRIKES AND POCKETS OF VERY HEAVY RAINFALL. COULD BE A PERIOD OF MVFR CIGS/VSBYS AT BLF/LWB/BCB THROUGH 15Z AS A RESULT. MOST MODELS AGRESSIVE WITH CONVECTION THIS AFTERNOON...AND IF CURRENT TREND IS A SIGN OF THINGS TO COME...MODELS MAY BE ON THE RIGHT TRACK. FOCUS WILL BE ON A WEAK FRONTAL BOUNDARY AND A FAIRLY HEALTHY SHORT WAVE TRACKING ESE FROM THE OH VALLEY...SLATED TO ARRIVE DURING THE AFTERNOON. MORNING ACTIVITY MAY DICTATE WHERE AFTERNOON ACTIVITY FORMS...WHICH COULD AT THAT POINT BE MAINLY EAST OF THE BLUE RIDGE. HAVE RETAINED VCTS IN ALL TAFS AS IN THE 06Z SET...BUT HAVE NOT IDENTIFIED ANY TEMPO OR PROB30 GROUPS FOR SPECIFIC PERIODS OF MORE LIKELY TSRA AT THIS POINT. AGAIN...CONVECTION MAY BE ACCOMPANIED BY MVFR-IFR CIGS/VSBYS...BUT TIMING NOT CERTAIN. OUTSIDE CONVECTION...WHICH MAY LINGER INTO THE EVENING HOURS...BUT SHOULD BE DONE BY 04Z...MOIST GROUND AND LOWER ATMOSPHERE SHOULD ALLOW FOR BETTER DEVELOPMENT OF RADIATIONAL FOG. HOWEVER...PERSISTENT MID-LEVEL DECK MAY TEND TO INHIBIT FOG DEVELOPMENT. HAVE ADVERTISED MVFR-IFR BR AT MOST TAF SITES...WITH LIFR AT LWB WHERE WET GROUND AND CALM WINDS SHOULD ALLOW FOR BETTER FOG DEVELOPMENT IN THE GREENBRIER VALLEY. WINDS THROUGH THE TAF PERIOD WILL BE MOSTLY LIGHT AND VARIABLE...BUT WILL TEND TO LEAN TOWARD THE SSE EAST OF THE BLUE RIDGE...AND SSW WEST OF THE BLUE RIDGE. SPEEDS 5KTS OR LESS THROUGH THE TAF VALID PERIOD...EXCEPT IN AND NEAR THUNDERSTORMS. MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD. MEDIUM TO HIGH CONFIDENCE IN WIND SPEED THROUGH THE TAF VALID PERIOD. LOW CONFIDENCE IN WIND DIRECTION THROUGH THE TAF VALID PERIOD. MEDIUM CONFIDENCE IN THUNDERSTORM POTENTIAL THROUGH THE TAF VALID PERIOD. EXTENDED AVIATION FORECAST... MODELS APPEAR IN DECENT AGREEMENT THAT THE COLD FRONT WILL STALL JUST SOUTH OF THE FORECAST AREA...BEFORE RETREATING BACK TO THE NORTH ON TUESDAY. EXPECT MAINLY VFR CONDITIONS THROUGH THE WORKWEEK OUTSIDE OF SCATTERED CONVECTION EACH AFTERNOON/ EVENING...AND LOCALIZED FOG/STRATUS EARLY EACH MORNING. SHOWER AND THUNDERSTORM CHANCES THURSDAY AS A NEW COLD FRONT MOVES INTO THE REGION FROM THE NORTHWEST. THIS FRONT SHOULD PUSH SOUTH OF THE AREA AND ALLOW FOR DRIER AND MOSTLY VFR CONDITIONS FRI-SAT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...RAB NEAR TERM...MBS SHORT TERM...RAB LONG TERM...RAB/WP AVIATION...MBS/NF/RAB
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
921 PM CDT TUE JUL 28 2015 .UPDATE...TOO MUCH UNCERTAINTY TO CONTINUE WITH LIKELY WORDING OVERNIGHT. HOWEVER WILL CONTINUE CHANCE POPS AS STILL EXPECT UPSTREAM AREA OF FRONTOGENETICAL FORCING TO CLIP SOUTHERN WISCONSIN BETWEEN 06Z AND 12Z. UNIMPRESSIVE LOW LEVEL JET BEGINNING TO PIVOT MORE WESTERLY WHICH DOES NOT BODE WELL FOR MORE WIDESPREAD CONVECTION. WIDESPREAD CONVECTION RUMBLING ACROSS CENTRAL IOWA ALONG OUTFLOW BOUNDARY AND WARM FRONT WILL CONTINUE TO SUPPRESS MAIN FORCING TO THE SOUTH OVERNIGHT. OVERNIGHT TEMPS LOOK IN GOOD SHAPE WITH WARM AND MUGGY CONDITIONS EXPECTED UNTIL LATE. && .AVIATION/06Z TAFS/...STILL EXPECT SCT CONVECTION TO AFFECT TAF SITES MAINLY BETWEEN 06Z AND 12Z. CIGS SHOULD LOWER BUT MOSTLY REMAIN VFR WITH RAPID CLEARING EXPECTED WED MRN. && .MARINE...FOR NOW KEPT NORTHERN ZONE IN SMALL CRAFT ADVISORY FOR LATER WED MRNG THRU THE AFTN. BOTH RAP AND EARLIER GFS WERE INDICATING STRONGER WINDS GUSTS AFFECTING NEAR SHORE WATERS THAN CURRENT FORECAST. IF 00Z NAM COMES IN WITH SIMILAR VALUES...THEN NEXT SHIFT MAY NEED TO EXPAND SMALL CRAFT TO INCLUDE SOUTHERN ZONES. && .PREV DISCUSSION... /ISSUED 341 PM CDT TUE JUL 28 2015/ TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM. CURRENT CONVECTION IN IOWA SHOULD REMAIN SOUTH OF THE AREA INTO THE EVENING HOURS...AS BEST UPWARD VERTICAL MOTION FIELDS REMAIN IN THAT AREA. MAY INCLUDE SOME LOWER END POPS IN THE FAR SOUTHWEST/SOUTH IN CASE THEY BUILD FURTHER TO THE NORTHEAST. SHOULD SEE MIDDLE TO HIGH CLOUDS LINGER INTO THE EARLY EVENING...WITH SOME BREAKS AT TIMES. A TOUGH FORECAST FOR TONIGHT INTO EARLY WEDNESDAY MORNING WITH POPS WITH THE PASSING COLD FRONT. THE SYNOPTIC MODELS...AND SOME OF THE MESOSCALE MODELS...ARE SHOWING A DECENT AMOUNT OF QPF WITH THE FRONTAL PASSAGE. HOWEVER...SOME OF THE MESOSCALE MODELS ARE MUCH LESS ROBUST WITH THE QPF. THE SYNOPTIC UPWARD VERTICAL MOTION IS MODEST AT BEST...WITH SOME LOW LEVEL FRONTOGENESIS AND A PASSING BUT MODEST 500 MB VORTICITY MAXIMUM. TALL SKINNY MEAN LAYER CAPES ON AREA FORECAST SOUNDINGS ARE SHOWN...WITH WEAK DEEP LAYER SHEAR. PRECIPITABLE WATER VALUES REMAIN QUITE HIGH...AROUND OR OVER 2.00 INCHES. THE LEVEL OF FREE CONVECTION IS AROUND THE 700 MB LEVEL...SO THINK ANY PRECIPITATION WILL BE RIGHT ALONG THE FRONT. THE UNCERTAINTY IS THERE AND THINGS MAY BE MORE WIDELY SCATTERED THAN CURRENTLY FORECAST. FOR NOW...WILL CONTINUE TO TIME LIKELY POPS EASTWARD ACROSS THE AREA LATER THIS EVENING AND OVERNIGHT. LOCALLY HEAVY RAINFALL IS POSSIBLE WITH HIGH MOISTURE CONTENT IN THE AIR. SMALL HAIL AND BRIEF GUSTY WINDS ARE POSSIBLE AS WELL...WITH THE BEST SEVERE RISK TO THE SOUTHWEST OF THE AREA. GUSTY WEST WINDS ARE EXPECTED WEDNESDAY...AS THE PRESSURE GRADIENT TIGHTENS. THE NORTHERN COUNTIES SHOULD SEE THE HIGHEST GUSTS...AROUND 25 TO 28 KNOTS OR SO. THE MIXING AND DRIER AIRMASS SHOULD RESULT IN HIGHS REACHING INTO THE MID 80S ACROSS THE AREA...PERHAPS A FEW DEGREES WARMER WITH FULL SUNSHINE IN THE AFTERNOON. SHORT TERM...WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE IS HIGH. AN OCCLUDED LOW WILL PREVAIL OVER HUDSON BAY CANADA WITH HIGH PRESSURE FROM THE CENTRAL PLAINS INTO THE OHIO RIVER VALLEY FOR THIS TIME PERIOD. THIS GIVES A WNWLY FLOW ALOFT AND AT THE SFC. BREEZY WINDS AND FULL SUNSHINE IN THE AFTERNOON WILL MIX OUT THE HIGHER DEWPOINTS MAKING FOR LOWER HUMIDITY...AND HIGH TEMPS IN THE MID TO UPPER 80S FOR THU AND FRI. A WEAK SFC TROUGH WILL PASS FRI AFT BUT THE MIXING WILL LIMIT THE CAPE...AND SFC CONVERGENCE WILL BE WEAK SO WILL MAINTAIN THE DRY FORECAST FOR NOW. LONG TERM...SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE IS MEDIUM. SRN WI WILL BE ON THE SRN PERIPHERY OF THE WESTERLIES FOR THIS PERIOD. AT THE SFC...A HIGH PRESSURE RIDGE WILL MOVE ACROSS THE REGION FOR SAT WITH A SFC TROUGH OR WEAK COLD FRONT APPROACHING FOR SAT NT AND SUN. THUS A RETURN OF HIGH THETAE AIR IS EXPECTED ALONG WITH CHANCES OF TSTORMS. THE FRONT MAY THEN STALL INTO MON SO TSTORM CHANCES CONTINUE. THE AREA MAY GET A BREAK FROM TSTORM CHANCES OF TUE BUT LOW CONFIDENCE AT THIS TIME. AVIATION/00Z TAFS/... BROKEN TO OVERCAST MIDDLE TO HIGH CLOUDS SHOULD LINGER ACROSS MOST OF THE AREA INTO THE EARLY EVENING HOURS. THERE MAY BE SOME EROSION OF THESE CLOUDS IN PARTS OF THE AREA. LIGHT/MODERATE SOUTH/SOUTHEAST WINDS ARE EXPECTED INTO EARLY THIS EVENING...BEFORE WEAKENING SOMEWHAT. AN AREA OF SHOWERS AND THUNDERSTORMS ARE LIKELY WITH THE COLD FRONTAL PASSAGE LATER TONIGHT INTO EARLY WEDNESDAY MORNING ACROSS TAF SITES. MAY SEE MVFR VISIBILITIES AND CEILINGS AT TIMES. THERE IS SOME UNCERTAINTY IF THESE SHOWERS AND STORMS WILL OCCUR...SO MAY GO WITH JUST SHOWERS AND VICINITY THUNDER IN TAFS FOR NOW. THIS WOULD BE FOR A THREE OR FOUR HOUR PERIOD LATER THIS EVENING AND OVERNIGHT AT EACH SITE. GUSTY WEST WINDS ARE EXPECTED WEDNESDAY BEHIND THE FRONT...WITH FREQUENT GUSTS TO AROUND 20 KNOTS. VFR CONDITIONS ARE EXPECTED WEDNESDAY AT ALL SITES. MARINE... ISSUED A SMALL CRAFT ADVISORY FOR THE NORTHERN MOST MARINE ZONE...PORT WASHINGTON TO SHEBOYGAN...FROM LATE WEDNESDAY MORNING INTO WEDNESDAY EVENING. GUSTY WEST WINDS ARE EXPECTED TO DEVELOP DURING THIS TIME...WITH FREQUENT GUSTS TO 25 KNOTS. THE WINDS SHOULD DIMINISH BY MIDDLE TO LATE WEDNESDAY EVENING. SIMILAR GUSTS MAY OCCUR ON THURSDAY AS WELL IN THIS AREA. THE REST OF THE NEARSHORE WATERS SHOULD SEE FREQUENT WEST GUSTS TO 20 KNOTS WEDNESDAY AND THURSDAY. THIS AREA WILL NEED TO BE MONITORED AS WELL FOR SMALL CRAFT ADVISORIES...GIVEN THE BORDERLINE GUSTS EXPECTED. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 11 AM TO 11 PM CDT WEDNESDAY FOR LMZ643. && $$ UPDATE...MBK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
657 PM CDT TUE JUL 28 2015 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND WEDNESDAY ISSUED AT 251 PM CDT TUE JUL 28 2015 SHOWERS AND STORMS RAPIDLY DISSIPATED EARLY THIS AFTERNOON AS THEY MOVED EAST INTO CENTRAL WISCONSIN. MEANWHILE...A COLD FRONT WAS LOCATIONS ACROSS WESTERN MINNESOTA. SHOWERS AND STORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT LATER THIS AFTERNOON AND THIS EVENING...AND THEN MOVE ACROSS NORTH-CENTRAL AND NORTHEAST WISCONSIN LATER THIS EVENING AND OVERNIGHT. THE SEVERE WEATHER POTENTIAL LOOKS VERY LOW AS BEST 0-6KM SHEAR LAGS BEHIND THE FRONT. HOWEVER...THIS IS THE TIME OF YEAR FOR WET MICROBURSTS...THUS WILL MENTION GUSTY WINDS AND LOCALLY HEAVY RAINFALL IN THE HAZARDOUS WEATHER OUTLOOK. FORMAL SPOTTER ACTIVATION IS NOT ANTICIPATED...BUT SPOTTERS ARE REQUESTED TO REPORT RAINFALL AMOUNTS OVER AN INCH OR WIND GUSTS OVER 40 MPH. KIND OF AN UNUSUAL EVENT FOR LATE JULY WILL TAKE PLACE ON WEDNESDAY. STRONG LOW PRESSURE ACROSS SOUTHERN CANADA WILL MOVE EAST TOWARDS HUDSON BAY. TIGHT PRESSURE GRADIENT AND STRONGER WINDS ALOFT SUPPORT WIND GUSTS OF 30 TO 35 MPH POSSIBLE. MIXING HEIGHTS ON THE BUFKIT SOUNDINGS INDICATED BETWEEN FIVE AND EIGHT THOUSAND FEET...WHICH COULD TAP WINDS AS STRONG AS 35 KNOTS. DID INCREASE WINDS ON WEDNESDAY TO ACCOUNT FOR DEEP MIXING AND STRONGER WINDS ALOFT. BASED ON TEMPERATURES UPSTREAM...BELIEVE GUIDANCE IS TOO WARM FOR HIGHS ON WEDNESDAY. .LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY ISSUED AT 251 PM CDT TUE JUL 28 2015 THE TIMING OF A COLD FRONT AND ASSOCIATED PCPN CHANCES OVER THE WEEKEND IS THE MAIN FCST CONCERN. THE REGION WILL REMAIN IN A FAST ZONAL WEST-NORTHWEST FLOW PATTERN THROUGH MOST OF THE PERIOD...WITH A SERIES OF S/W TROFS BRUSHING NORTHERN WI...AND FRONTAL PASSAGES EVERY COUPLE DAYS. THERE IS GOOD MODEL AGREEMENT ON A WEAK COLD FRONT MOVING THROUGH THE AREA THURSDAY NIGHT INTO FRIDAY. HAVE ADDED A SMALL POP OVER NORTHERN WI LATE THU NGT...WHEN THE FRONT AND A S/W TROF MAY COMBINE TO PRODUCE ISOLD/SCT LIGHT SHOWERS. WEAK HIGH PRESSURE WILL PUSH ACROSS THE WESTERN GREAT LAKES ON FRIDAY NIGHT AND SATURDAY...BRINGING DRY CONDITIONS. FCST GETS A BIT MUDDLED OVER THE WEEKEND AND BEYOND...AS MODELS HAVE TRENDED SLOWER WITH A COLD FRONTAL PASSAGE. THE ECMWF HAS NOT ONLY SLOWED THE FRONT DOWN CONSIDERABLY...BUT IS ALSO SHOWING A WEAKER FEATURE THAN YESTERDAY. WILL LEAN TOWARD THE GFS...WHICH HAS A STRONGER AND MORE PROGRESSIVE FRONTAL PASSAGE LATE SATURDAY NIGHT INTO SUNDAY. THERE IS ALSO CONCERN ABOUT WHERE THE FRONT WILL RESIDE AFTER IT MOVES THROUGH...AND WHETHER IT WILL REMAIN CLOSE ENOUGH TO GENERATE ADDITIONAL PCPN EARLY NEXT WEEK... ESPECIALLY OVER OUR SOUTHERN AND EASTERN COUNTIES. WILL CONTINUE TO FOCUS HIGHEST POPS ON SATURDAY NIGHT/SUNDAY PERIOD FOR NOW... BUT THIS MAY BE SUBJECT TO CHANGE WITH SUBSEQUENT FCSTS. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 656 PM CDT TUE JUL 28 2015 CONFIDENCE IN THE EARLY PART OF THE TAF VALID PERIOD IS NOT AS GOOD AS ONE WOULD LIKE. MOST OF THE CONVECTION LATE THIS AFTERNOON WAS CONFINED TO IOWA. THERE WAS JUST A THIN LINE OF SHOWERS ALONG THE APPROACHING COLD FRONT...IN EASTERN MINNESOTA...AND ISOLATED/SCATTERED SHOWERS AHEAD OF THAT IN WESTERN WISCONSIN. LOCAL MESO GRAPHICS INDICATED MUCAPE VALUES IN EXCESS OF 1000J/KG THERE AT 23Z BUT THAT AREA ALSO HAD 50-100J/KG OF CIN. THERE WAS A MULTITUDE OF CLOUD HEIGHTS ACROSS WISCONSIN AT 23Z BUT OBSERVATION SITES ALL INDICATED VFR CIGS. HAVE SOME MVFR VSBYS FOG PRIOR TO FRONTAL PASSAGE AND SOME MVFR/IFR VSBYS/CIGS WITH THUNDER. THE 22Z HRRR HAD MORE AREAL COVERAGE AHEAD OF THE FRONT...SO NOT SO SURE ABOUT PREVAILING VCSH THAT WAS IN THE FORECAST BUT DID NOT REMOVE SINCE THERE IS STILL PLENTY OF INSTABILITY AND DEW POINTS WERE MOST 65 TO 70F IN THE AREA. ALSO...THE HRRR BROUGHT CONVECTION FROM IOWA INTO EAST CENTRAL WISCONSIN LATE TONIGHT...TOWARD DAYBREAK...SO THUNDER MAY ONLY IMPACT OSH/MTW/ATW/GRB TAF SITES. ONCE THE FRONT PASSES WINDS WILL INCREASE CONSIDERABLY. 925MB WINDS ARE FORECAST TO BE IN THE 30 TO 35 KT RANGE AT 12Z SO HAVE SUSTAINED WINDS AROUND 20 KTS WITH GUSTS AROUND 30 TO 33 KTS. VFR CONDITIONS SHOULD PREVAIL ON WEDNESDAY MORNING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ECKBERG LONG TERM......KIECKBUSCH AVIATION.......MG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
604 PM CDT TUE JUL 28 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 331 PM CDT TUE JUL 28 2015 LATEST WATER VAPOR SATELLITE IMAGERY SHOWS VIGOROUS SHORTWAVE TROUGH OVER EASTERN IOWA AND SOUTHERN WISCONSIN. LATEST MOSAIC RADAR INDICATING SHOWERS/THUNDERSTORMS HAVE WEAKENED WITH THE SHORTWAVE TROUGH EARLY THIS AFTERNOON. LATEST 19Z SURFACE ANALYSIS SHOWING COLD FRONT EXTENDING FROM WESTERN MINNESOTA INTO EASTERN NEBRASKA. MAIN FORECAST CONCERNS TONIGHT ARE PRECIPITATION CHANCES AND POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING. WITH THE SHORTWAVE TROUGH AND ASSOCIATED PRECIPITATION/CLOUDS OVER THE FORECAST AREA MUCH OF TODAY...THIS HAS ALLOWED THE ATMOSPHERE TO BE CAPPED OVER THE FORECAST AREA. THIS IS EVIDENT WITH THE LATEST 28.18Z RAP BUFKIT SOUNDINGS INDICATING A STRONG INVERSION OVER MUCH OF THE FORECAST AREA. IN ADDITION...THE LATEST 28.17Z HRRR/HOPWRF SHOW VERY LITTLE CONVECTION TO DEVELOP ALONG THE COLD FRONT...DUE TO LACK OF CONVERGENCE ALONG FRONT...AND HINT AT POSSIBLE DEVELOPMENT OF ISOLATED SHOWER/THUNDERSTORM MAINLY EAST OF THE MISSISSIPPI RIVER AFTER 00Z WEDNESDAY. THE HRRR/HOPWRF INDICATE SHOWER/THUNDERSTORM DEVELOPMENT SOUTH OF FORECAST AREA IN CENTRAL IOWA...WHERE BETTER MOISTURE CONVERGENCE AND LIFT IS ALONG OUTFLOW BOUNDARY FROM THIS MORNINGS MCS. DUE TO THE LOSS OF INSTABILITY/FORECAST AREA CAPPED AND LACK OF MOISTURE CONVERGENCE ALONG FRONT...HAVE REDUCED PRECIPITATION CHANCES ACROSS THE FORECAST AREA THIS EVENING/TONIGHT. PLUS...WITH THE BETTER LIFT/MOISTURE CONVERGENCE AND INSTABILITY SOUTH OF THE FORECAST AREA. SEVERE WEATHER THREAT WILL BE CONFINED TO THE FAR SOUTHERN PART OF THE FORECAST AREA OR SOUTH OF THE FORECAST AREA. UPPER LEVEL TROUGH DIGS INTO THE GREAT LAKES REGION AND PRESSURE GRADIENT TIGHTENS BEHIND COLD FRONT ACROSS THE FORECAST AREA WEDNESDAY. THE 28.12Z GFS/NAM BUFKIT SOUNDINGS SUGGEST AREA WILL MIX UP TO AROUND 800MB AND WINDS AT THIS LEVEL INCREASE TO AROUND 30 KNOTS. HAVE INCREASED WINDS/WIND GUSTS ACROSS THE FORECAST AREA...ESPECIALLY IN THE HIGHER TERRAIN AND OPEN AREAS WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 331 PM CDT TUE JUL 28 2015 SURFACE RIDGE BUILDS INTO THE CENTRAL PLAINS THURSDAY INTO FRIDAY. WITH SUBSIDENCE UNDERNEATH HIGH AND MAIN SHORTWAVE ENERGY OVER LAKE SUPERIOR AND SOUTHERN CANADA...FORECAST AREA WILL REMAIN DRY THROUGH THE END OF THE WEEK. MAIN FORECAST CONCERNS FRIDAY NIGHT INTO TUESDAY ARE PRECIPITATION CHANCES THROUGH THE PERIOD. THE 28.12Z GFS/ECMWF/GEM ARE IN DECENT AGREEMENT IN DIGGING UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION THROUGH 00Z SUNDAY...THEN DIVERGE ON THE STRENGTH OF THE UPPER LEVEL TROUGH. WHERE THE 28.12Z GFS/GEM ARE STRONGER WITH THE UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION THAN THE ECMWF. THE 28.12Z GFS/GEM/ECMWF INDICATE DIFFERENCES IN TIMING OF SHORTWAVE TROUGHS EMBEDDED IN THE NORTHWEST FLOW ALOFT OVER THE GREAT LAKES REGION. THE 28.12Z GFS/GEM/ECMWF SUGGEST ENOUGH LIFT AND MOISTURE CONVERGENCE IN ASSOCIATION WITH EACH SHORTWAVE TROUGH TO WARRANT CHANCES OF SHOWERS/THUNDERSTORMS ACROSS MUCH OF THE FORECAST AREA FROM SATURDAY NIGHT INTO TUESDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING) ISSUED AT 604 PM CDT TUE JUL 28 2015 THE COLD FRONT CONTINUES TO MAKE GOOD PROGRESS ACROSS MINNESOTA LATE THIS AFTERNOON AND IS EXPECTED TO PASS THROUGH BOTH TAF SITES THIS EVENING. STILL VERY LITTLE CONVECTIVE ACTIVITY ALONG THE FRONT AND THE TRENDS IN THE 28.20Z HRRR-CR AND 28.21Z HRRR CONTINUE TO SHOW THE FRONT LIKELY PASSING THROUGH WITH JUST SOME SCATTERED ACTIVITY AT MOST ALONG IT. PLAN TO CONTINUE THE TREND OF SHOWING A VCTS FOR BOTH TAF SITES THIS EVENING UNTIL THE FRONT MOVES THROUGH. SATELLITE IMAGERY IS SHOWING A PRETTY EXPANSIVE SHIELD OF CLOUDS AHEAD OF THE FRONT WITH MOST OF THE CEILINGS VFR. ONCE THE FRONT GOES THROUGH...THE WINDS WILL SWING AROUND TO THE WEST AND THE SKIES SHOULD CLEAR OUT PRETTY RAPIDLY. ONCE THE INVERSION GETS MIXED OUT WEDNESDAY MORNING...THE WEST WINDS WILL BECOME GUSTY WITH GUSTS IN THE 25 TO 30 KNOT RANGE FOR THE LATE MORNING AND ENTIRE AFTERNOON. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM...DTJ AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1131 AM MDT MON JUL 27 2015 .UPDATE... ISSUED AT 1107 AM MDT MON JUL 27 2015 EXTREME RED FLAG CONDITIONS STILL ON TRACK FOR THIS AFTERNOON...ESPECIALLY TO THE WEST OF THE LARAMIE RANGE. FUELS IN FIRE WEATHER ZONE 306 (UPPER NORTH PLATTE RIVER BASIN) HAVE BECOME CRITICAL AND THIS ZONE HAS BEEN ADDED TO THE RED FLAG WARNING. RH VALUES AND WINDS IN ZONE 310 WILL BE MORE MARGINAL NEAR THE SFC TROUGH...HOWEVER WILL KEEP THEM IN THE WARNING. THE THREAT FOR A STRONG TO MARGINALLY SVR STORM IS STILL MOSTLY CONFINED TO THE FAR EASTERN ZONES WHERE THE RUC SHOWS CAPE VALUES OF AROUND 1250 J/KG BY LATE AFTN. && .SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT) ISSUED AT 145 AM MDT MON JUL 27 2015 ONE MORE HOT DAY FOR SOUTHEAST WYOMING AND THE NEBRASKA PANHANDLE TODAY...THEN COOLER READINGS FOR THE REST OF THE WORK WEEK FOLLOWING THE PASSAGE OF A COLD FRONT TONIGHT. GUSTY WEST TO SOUTHWEST WINDS WILL ACCOMPANY THE VERY WARM AIR TODAY. IN FACT WIND SPEEDS WILL APPROACH HIGH WIND WARNING CRITERIA ACROSS MUCH OF CARBON COUNTY AND INTO WESTERN CONVERSE COUNTY THIS AFTERNOON WITH WIND GUSTS TO 50 MPH OR GREATER. THE COMBINATION OF STRONG WINDS AND WARM TEMPERATURES WILL PRODUCE VERY LOW HUMIDITY VALUES...AND WITH THAT COMES AN EXTREME RISK FOR RAPIDLY SPREADING WILDFIRE. A RED FLAG WARNING IS IN EFFECT FOR MUCH OF SOUTHEAST WYOMING DUE TO THESE HAZARDOUS CONDITIONS. SWITCHING FROM FIRE DANGER IN SOUTHEAST WYOMING TO SEVERE THUNDERSTORM CHANCES INTO THE NEBRASKA PANHANDLE. HOT AND HUMID AIR INTO THE PANHANDLE WILL SET THE STAGE FOR THUNDERSTORMS THIS AFTERNOON. THERE IS SOME UNCERTAINTY AS TO WHERE THUNDERSTORMS WILL ACTUALLY DEVELOP BUT A PUNCH OF DRY AIR AHEAD OF AN UPPER LEVEL TROUGH OVER THE NORTHERN ROCKIES WILL LIKELY BE THE TRIGGER WHICH SETS OFF THUNDERSTORMS TODAY. THUNDERSTORMS COULD DEVELOP ANYWHERE FROM ALONG THE NEBRASKA/WYOMING BORDER TO JUST EAST OF THE FORECAST AREA THIS AFTERNOON...BUT THAT WILL DEPEND ON WHERE A DEVELOPING DRY LINE/STRONGEST LOW LEVEL CONVERGENCE OCCURS. BEST GUESS AT THIS TIME IS FOR THUNDERSTORM DEVELOPMENT IN THE WESTERN NEBRASKA PANHANDLE. THUNDERSTORMS THAT DEVELOP WILL HAVE A HIGH LIKELIHOOD OF QUICKLY BECOMING SEVERE. 00Z NAM SHOWING UPWARDS OF 4000J/KG SB CAPE AT 21Z TODAY FROM AROUND CHADRON TO SIDNEY. SHOULD THIS BE THE CASE THEN LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE. THUNDERSTORMS THAT DEVELOP WILL QUICKLY MOVE EAST AND OUT OF THE FORECAST AREA BY EARLY EVENING. COOLER DRIER AIR WILL SETTLE INTO THE REGION TUESDAY AND WEDNESDAY WITH VIRTUALLY NO CHANCE FOR PRECIPITATION. TEMPERATURES TUESDAY WILL BE CLOSER TO NORMAL WITH HIGHS MAINLY IN THE 80S ACROSS THE PLAINS WITH 70S INTO THE HIGHER ELEVATIONS OF SOUTHEAST WYOMING OUTSIDE OF THE MOUNTAINS. TUESDAY WILL BE BREEZY TO WINDY ACROSS THE FORECAST AREA WITH GUSTY WEST TO NORTHWEST WINDS IN PLACE. RELATIVELY LIGHT WINDS WILL BE IN PLACE WEDNESDAY AND SLIGHTLY WARMER TEMPERATURES WITH HIGHS MAINLY IN THE 80S. .LONG TERM...(THURSDAY THROUGH SUNDAY) ISSUED AT 300 AM MDT MON JUL 27 2015 THE UPPER RIDGE CENTER OVER THE SOUTHERN HIGH PLAINS WILL RETROGRADE WEST OVER THE FOUR CORNERS BY THIS WEEKEND. THIS PATTERN WILL SUPPORT A WEST TO NORTHWEST FLOW ALOFT OVER THE CWA. PRECIPITATION CHANCES WILL BE ALMOST NON-EXISTENT. THE EXCEPTIONS MAY BE ISOLATED TSTORMS OVER THE FAR EASTERN ZONES LATE THURSDAY WITH WEAK LOW LEVEL CONVERGENCE...AND OVER THE SOUTHEAST WY MOUNTAINS SUNDAY AFTERNOON DUE TO SOME SUBTROPICAL MOISTURE AND OROGRAPHIC LIFT. LIGHT WINDS WILL PREVAIL WITH A WEAK SURFACE PRESSURE GRADIENT. TEMPERATURES WILL AVERAGE SLIGHT ABOVE SEASONAL NORMALS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1107 AM MDT MON JUL 27 2015 THE MAIN CONCERN WITH THIS TAF ISSUANCE IS THE POTENTIAL FOR THUNDERSTORMS THIS AFTERNOON. LATEST WATER VAPOR LOOP WAS SHOWING THE STRONG UPPER LEVEL TROF MOVING THROUGH IDAHO. MEANWHILE...THE DRY SLOT WAS STARTING TO PUSH INTO WESTERN COLORADO. THE SURFACE TROF WAS SITUATED ALONG THE LEE SIDE OF THE LARAMIE RANGE WITH THE BULK OF THE HIGHER DEWPOINTS EAST IN THE NEBRASKA PANHANDLE. AS THIS UPPER LEVEL TROF PUSHES EAST TODAY...THIS SHOULD HELP INITIATE SOME STRONG TO SEVERE STORMS ALONG THE SURFACE TROF LATE THIS AFTERNOON. AS A RESULT...THE NEBRASKA TAF SITES HAVE A PRETTY GOOD SHOT OF SEEING SOME OF THESE STORMS THIS AFTERNOON. THE MAIN CONCERN WITH THESE THUNDERSTORMS WILL STRONG GUSTY WINDS AND LARGE HAIL. THE UPPER LEVEL TROF AND ITS ASSOCIATED SURFACE FRONT IS PROGGED TO SHIFT THROUGH THE WYOMING TAF SITES EARLY THIS EVENING BEFORE 03Z WHILE THE NEBRASKA TAF SITES SHOULD SEE THIS WIND SHIFT TO THE NORTHWEST BETWEEN BETWEEN 03Z- 06Z. GUSTY WINDS UP 50 MPH MAY BE POSSIBLE AFTER THIS FRONT MOVES THROUGH. && .FIRE WEATHER... ISSUED AT 204 AM MDT MON JUL 27 2015 A RED FLAG WARNING IS IN EFFECT TODAY FOR PORTIONS OF SOUTHEAST WYOMING WHERE GRASSES AND OTHER QUICK TO DRY VEGETATION IS SUPPORTIVE OF RAPID FIRE GROWTH. UNSEASONABLY STRONG WEST TO SOUTHWEST WINDS WILL COMBINE WITH VERY LOW HUMIDITIES TO PRODUCE EXTREME FIRE CONDITIONS TODAY...PARTICULARLY OVER PORTIONS OF CARBON COUNTY AND FAR WESTERN CONVERSE COUNTY WHERE WIND GUSTS TO 50 MPH ARE LIKELY. COOLER TEMPERATURES WILL SPREAD ACROSS THE REGION TUESDAY BUT GUSTY WEST TO NORTHWEST WINDS AND LOW HUMIDITIES WILL MAKE FOR MARGINAL FIRE CONDITIONS. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR WYZ301-302-304- 306-310. NE...NONE. && $$ UPDATE...ZF SHORT TERM...SML LONG TERM...MAJ AVIATION...REC FIRE WEATHER...SML/MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
119 AM MDT MON JUL 27 2015 .UPDATE... ISSUED AT 934 PM MDT SUN JUL 26 2015 MINOR UPDATE TO INCLUDE MENTION OF PATCHY FOG FOR THE SOUTHERN NE PANHANDLE AFTER 06Z. DUAL-POL RAINFALL ESTIMATES ARE IN THE AREA OF 2-4 INCHES ROUGHLY ALONG A KIMBALL TO BROADWATER LINE FROM THE CONVECTION EARLIER TODAY. BUFKIT SOUNDINGS APPEAR TO BE ON TRACK WITH GOOD LLVL SATURATION OVERNIGHT...ALONG WITH CLEAR SKIES AND LIGHT WINDS THAT ARE ALREADY TAKING SHAPE. HRRR SHOWS POCKETS OF REDUCED VISIBILITY AS FAR WEST AS CYS...BUT BELIEVE WE WILL STAY MIXED ENOUGH TO KEEP FOG AT BAY. HOWEVER WITH DEW POINTS STILL IN THE MID 50S AMID SOUTHEASTERLY SFC FLOW...WILL NEED TO MONITOR. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 246 PM MDT SUN JUL 26 2015 QUITE AN ACTIVE AFTERNOON WITH SEVERE THUNDERSTORMS EAST AND NEAR CRITICAL FIRE WEATHER CONDITIONS WEST. CURRENTLY...WE HAVE A DRY LINE PUSHING INTO THE NEBRASKA PANHANDLE THIS AFTERNOON. BEHIND THE DRY LINE...DEWPOINTS IN THE 20S AND 30S ARE BEING REPORTED IN SOUTHEASTERN WYOMING. AHEAD OF THIS LINE...DEWPOINTS IN THE MID TO UPPER 50S ARE BEING OBSERVED. OUT WEST IN CARBON COUNTY...GETTING WIND GUSTS TO 30 MPH AT RAWLINS AND LOW 20 MPH RANGE DOWN BY DIXON. DECIDED TO KEEP THE CURRENT RED FLAG WARNING GOING FOR FWZ 304 THROUGH 8 PM THIS EVENING. STRONG WIND EVENT STILL ON TRACK FOR MONDAY AS A PACIFIC LOW PRESSURE SYSTEM TRACKS INTO WESTERN MONTANA AND NORTHWESTERN WYOMING. LATEST NAM FORECAST SOUNDINGS SHOWING US MIXING UP TO NEAR 500MBS MONDAY WITH FORECAST WINDS AT THIS LEVEL OF 45-50KTS. WE COULD BE LOOKING AT SOME HIGH WIND CRITERIA...ESPECIALLY FOR OUR WIND PRONE AREAS OF INTERSTATES 80 AND 25. PROBABLY OF MORE SIGNIFICANCE IS WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS THAT ARE ALMOST CERTAIN TO HAPPEN MONDAY. FORECAST MIN HUMIDITIES OF 7 TO 15 PERCENT LOOK TO BE WIDESPREAD MONDAY...ESPECIALLY WITH POOR OVERNIGHT RECOVERIES. WENT AHEAD AND UPGRADED PREVIOUS FIRE WEATHER WATCHES TO WARNINGS WHERE FUELS ARE REPORTED RECEPTIVE. WHILE DEALING WITH RED FLAG CONDITIONS ACROSS SOUTHEAST WYOMING...WE COULD BE DEALING WITH SEVERE THUNDERSTORMS IN THE PANHANDLE AHEAD OF THAT FRONT. NAM FORECAST MOST UNSTABLE CAPE ACROSS THE PANHANDLE MONDAY AFTERNOON FORECAST AROUND 2000J/KG. FORECAST SHEAR 0-6KM AROUND 33KTS...CAN NOT RULE OUT SEVERE THUNDERSTORMS OUT THERE FOR MONDAY AFTERNOON. ESPECIALLY WITH THE TIMING OF THE FRONT MOVING THROUGH LATE AFTERNOON/EARLY EVENING. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 246 PM MDT SUN JUL 26 2015 PRETTY QUIET EXTENDED PERIOD AS THE SUBTROPICAL RIDGE REMAINS ANCHORED NEAR THE FOUR CORNERS REGION AND KEEPS A DRY WESTERLY MIDLVL FLOW OVER THE CWA. TEMPS ON WED WILL BE COOL...HOWEVER WITH A DRY AIRMASS IN PLACE...MIN RH VALUES WILL STILL DROP TO 10-15 PERCENT OVER CARBON COUNTY. COULD BE AN ISOLATED STORM OVER THE SOUTHERN LARAMIE RANGE DURING THE EVENING AS SOUTHEASTERLY WINDS ACROSS THE PLAINS PRODUCES CONVERGENCE. WE WILL SEE 5-10 DEGREES OF WARMING FOR THURS AND THEN LITTLE CHANGE THROUGH NEXT WEEKEND. 700- 500MB FLOW REMAINS WEST NORTHWEST THROUGH SATURDAY WITH THE GFS SHOWING PW VALUES REMAINING 0.25-0.50 INCHES...WHICH IS WELL BELOW NORMAL FOR THIS TIME OF YEAR. CONVECTION WILL BE REALLY STYMIED IN THIS PATTERN. ALTHOUGH RH VALUES WILL DROP TO BELOW CRITICAL LEVELS TO THE WEST OF THE LARAMIE RANGE ON ALL AFTNS...THE WEAK GRADIENTS AND WINDS WILL LIKELY KEEP FIRE WEATHER HIGHLIGHTS LIMITED. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 119 AM MDT SUN JUL 27 2015 STRONG WEST TO SOUTHWEST WINDS WITH GUST TO AROUND 50 MPH THIS AFTERNOON OVER HIGHER ELEVATIONS OF SOUTHEAST WYOMING. THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE NEBRASKA PANHANDLE THIS AFTERNOON. A FEW SEVERE THUNDERSTORMS WILL BE POSSIBLE WITH HAIL 1 INCH IN DIAMETER OR LARGER AND 60 MPH WIND GUSTS. THUNDERSTORMS WILL QUICKLY PUSH EAST INTO CENTRAL NEBRASKA BY THIS EVENING. && .FIRE WEATHER... ISSUED AT 246 PM MDT SUN JUL 26 2015 MARGINAL CRITICAL FIRE WEATHER CONDITIONS CONTINUE THIS AFTERNOON FOR WESTERN CARBON COUNTY WITH WINDS EASING TEMPORARILY AFTER SUNSET. WINDS BEGIN TO INCREASE AFTER MIDNIGHT TONIGHT AND WILL BECOME QUITE STRONG MONDAY. EXPECT POOR OVERNIGHT HUMIDITY RECOVERIES...ESPECIALLY WEST OF THE LARAMIE RANGE AS THESE WINDS INCREASE. A DRY COLD FRONT IS STILL EXPECTED TO MOVE INTO THE AREA LATE MONDAY AFTERNOON. AHEAD OF THIS FRONT...WIDESPREAD WIND GUSTS IN EXCESS OF 40 MPH ARE LIKELY. COULD SEE CRITICAL FIRE WEATHER CONDITIONS CONTINUING INTO TUESDAY AS NORTHWEST WINDS WILL REMAIN STRONG AND DRY AIR REMAINS IN PLACE. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...RED FLAG WARNING FROM 9 AM THIS MORNING TO 8 PM MDT THIS EVENING FOR WYZ301-302-304-310. NE...NONE. && $$ UPDATE...CLH SHORT TERM...GCC LONG TERM...ZF AVIATION...TJT FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1125 PM MDT TUE JUL 28 2015 .UPDATE... ISSUED AT 1115 PM MDT TUE JUL 28 2015 VERY LITTLE IN THE WAY OF CONVECTION HAS OCCURRED THIS EVENING OVER THE AREA...DESPITE MOST MODELS...INCLUDING NEWLY ARRIVING 00Z RUNS...INSISTING ON -SHRA/-TSRA ALONG AND EAST OF THE MOUNTAINS THROUGH THE NIGHT. LATEST 03Z/04Z RUNS OF THE HRRR HAVE FINALLY CAUGHT ON TO THE DRY TREND...WITH JUST SOME VERY ISOLATED SHOWERS ACROSS THE EASTERN MOUNTAINS AND PLAINS THROUGH THE NIGHT...BEST CHANCES OVER BACA COUNTY AS DEEPER CONVECTION STAYS FAIRLY CLOSE TO THE SE CORNER OF THE STATE. WILL DROP THE MENTION OF THUNDER FROM MANY ZONES FOR THE REMAINDER OF THE NIGHT...BUT KEEP A MENTION OF SOME ISOLATED -SHRA OVER THE ERN MTS/PLAINS AS WEAK WARM ADVECTIVE LIFT MAY FINALLY PRODUCE SOME LIGHTER PRECIP AFTER MIDNIGHT. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 259 PM MDT TUE JUL 28 2015 ...COOLER WITH INCREASED CHANCES OF STORMS... CURRENT WATER VAPOR IMAGERY AND UPPER AIR ANALYSIS CONTINUES TO INDICATE MODERATE WEST TO SOUTHWEST FLOW ALOFT ACROSS THE STATE WITH A BROAD UPPER HIGH ACROSS THE SOUTHERN HIGH PLAINS BUILDING INTO THE SOUTHERN ROCKIES AS STRONG UPPER TROUGH CONTINUES TO TRANSLATE EAST ACROSS THE UPPER MIDWEST AND NORTHERN HIGH PLAINS. WATER VAPOR IMAGERY CONTINUES TO INDICATE MONSOONAL MOISTURE PLUME ACROSS THE DESERT SW AND SOUTHERN ROCKIES STREAMING ACROSS SOUTHERN COLORADO AND INTO WESTERN KANSAS AT THIS TIME. AT THE SFC...THIS MORNINGS PASSING COLD FRONT HAS MOVED INTO EAST CENTRAL NEW MEXICO AND THE WESTERN TEXAS PANHANDLE...WITH BREEZY EAST TO SOUTHEAST WINDS ACROSS THE EASTERN PLAINS KEEPING TEMPERATURES SOME 10 DEGREES COOLER THAN THIS SAME TIME YESTERDAY. FURTHER WEST...TEMPS ARE RUNNING SIMILAR TO YESTERDAY. REGIONAL RADARS ONLY INDICATING A FEW ECHOES ACROSS THE SOUTHERN MTS WITH A BETTER COVERAGE OF STORMS ACROSS NORTH CENTRAL AND NORTHEAST NEW MEXICO. TONIGHT AND WEDNESDAY...FLOW ALOFT SLOWLY BECOMES MORE WESTERLY AS UPPER MIDWEST SYSTEM CONTINUES TO MOVE EAST AND UPPER HIGH CONTINUES TO BUILD WEST INTO THE SOUTHERN ROCKIES...OWNING TO A SLIGHT INCREASE IN MONSOONAL MOISTURE ACROSS THE AREA THROUGH THE DAY TOMORROW. MODELS CONTINUE TO INDICATE CONVECTION ACROSS NORTH CENTRAL NEW MEXICO TO CONTINUE TO LIFT NORTHEAST AND DEVELOPING INTO AN MCS ROLLING ACROSS THE SOUTHEAST COLORADO AND NEW MEXICO BORDER LATE TONIGHT AND INTO EARLY WEDNESDAY MORNING AND HAVE KEPT THE BEST POPS ACROSS THIS AREA. ACROSS THE REST OF THE AREA...HAVE KEPT ISOLATED POPS THROUGH THE EARLY EVENING. MODEL SOUNDINGS INDICATING INCREASING MOISTURE WITHIN THE LOW LEVEL UPSLOPE ACROSS THE EASTERN PLAINS...ALONG WITH DEVELOPING MID LEVEL WAA...TO SUPPORT ELEVATED CONVECTION AND POSSIBLE SHOWERS AND A FEW STORMS ACROSS THE EASTERN MTS AND ADJACENT PLAINS LATER THIS EVENING AND OVERNIGHT. THE INCREASED AVAILABLE MOISTURE ACROSS THE AREA TOMORROW SHOULD LEAD TO BETTER COVERAGE OF STORMS OVER ALL OF THE HIGHER TERRAIN WITH STORMS SPREADING EAST ACROSS THE ADJACENT PLAINS THROUGH THE AFTERNOON. THE BEST COVERAGE OF STORMS REMAINS ACROSS THE SOUTHERN MTS AND ADJACENT PLAINS...WITH THE PROXIMITY TO THE MONSOONAL PLUME. HIGH TEMPERATURES ARE EXPECTED TO BE NEAR TO WELL BELOW SEASONAL AVERAGES...COOLEST ACROSS THE EASTERN PLAINS. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 259 PM MDT TUE JUL 28 2015 LATEST MODEL RUNS SHOW SOUTHERLY TAP OF MONSOON MOISTURE WILL REMAIN ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH FRIDAY WHILE AT THE SURFACE LOW LEVEL SOUTHEAST FLOW WILL ADVECT 50 AND LOWER 60 DEW POINTS BACK INTO SOUTHEAST CO. WEAK DISTURBANCES ROTATING NORTHWARD OUT OF NEW MEXICO WILL GET SHUNTED EASTWARD ACROSS SOUTHERN SECTIONS OF THE FORECAST AREA PROVIDING FORCING FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THURSDAY...WITH MAJORITY OF THE ACTIVITY EXPECTED DURING THE AFTERNOON AND EVENING HOURS. HOWEVER SEVERAL OF THE SHORT AND MEDIUM RANGE MODELS SUGGEST ACTIVITY MAY PERSIST WED NIGHT NORTH OF THE STALLED FRONTAL BOUNDARY ACROSS EAST CENTRAL NM/TX PANHANDLE WHICH MAY AFFECT SOUTHERN PORTIONS OF THE SOUTHEAST PLAINS. THERE IS SUFFICIENT AGREEMENT IN THE MODELS TO KEEP AT LEAST SOME ISOLATED TO LOW END SCATTERED POPS ACROSS THE RATON RIDGE AND FAR SOUTHEAST CORNER WED NIGHT THROUGH THURS MORNING...BUT HUNCH IS MORE WIDESPREAD ACTIVITY BE FARTHER SOUTH IN CLOSER PROXIMITY TO THE FRONTAL BOUNDARY. THURSDAY...THE UPPER HIGH BUILDS ACROSS THE GREAT BASIN AND WESTERN US...WHICH PUTS CO UNDER A MORE NW FLOW COMPONENT ALOFT. STILL PLENTY OF MOISTURE AVAILABLE WITH DEW POINTS REMAINING IN THE 50S AND LOWER 60S ACROSS EASTERN SECTIONS OF THE DISTRICT...WITH 40S ACROSS THE SOUTHWEST MTS/SAN LUIS VALLEY. BUT RISING HEIGHTS ALOFT REALLY CUTS BACK ON CAPE VALUES...AND APPEARS TRAJECTORY FOR ANY WEAK DISTURBANCES EMBEDDED WITHIN THE MONSOON PLUME MAY SHIFT OFF TO THE WEST...ACROSS AZ/NM. SO THURS LOOKS LIKE ANOTHER DAY OF NEAR TO SLIGHTLY BELOW CLIMO TEMPERATURES...WITH GREATEST POPS ACROSS THE SE MTS...AND SRN SECTIONS OF THE DISTRICT. LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY STORM THREAT...AS SHEAR LOOKS TOO WEAK TO SUPPORT MUCH OF A SEVERE THREAT. FRIDAY LOOKS A TAD MORE ACTIVE NOW FOR THE SOUTHWEST MOUNTAINS AS ANOTHER DISTURBANCE ENTERS THE 4 CORNERS REGION DURING THE AFTERNOON. AGAIN...0-6KM SHEAR VALUES LOOK RELATIVELY WEAK...AND CAPE REMAINS BELOW 1000 J/KG...SO MAIN THREAT WITH THUNDERSTORMS WILL BE LOCALLY HEAVY RAINFALL. DRIER AND WARMER WEATHER IS EXPECTED FOR THE WEEKEND AS NORTHWEST FLOW ALOFT ADVECTS DRIER AIR INTO THE REGION ALOFT. SFC DEW POINTS START TO FALL OFF WITH AFTERNOON MIXING ACROSS THE I-25 CORRIDOR...AND MOST THUNDERSTORMS SHOULD STAY CONFINED TO THE MOUNTAIN AREAS. EVENTUALLY ANOTHER UPSWING IN THUNDERSTORM CHANCES MAY SPREAD INTO WESTERN CO BY EARLY NEXT WEEK AS MONSOON MOISTURE ENTRAINED WITHIN THE UPPER HIGH SPREADS IN FROM THE WEST. GFS SUGGESTS ANOTHER FRONT MAY DROP THROUGH THE PLAINS FOR TUESDAY...INCREASING POPS FOR THE EASTERN SECTIONS AS WELL. ECMWF LOOKS A TOUCH SLOWER THAN GFS...BUT WILL START TO TREND DOWN MAX TEMPS A FEW DEGREES FOR NEXT TUES. -KT && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1115 PM MDT TUE JUL 28 2015 HAVE DROPPED THE MENTION OF -SHRA OVERNIGHT FROM ALL TAF SITES AS PRECIP HAS BEEN VERY SLOW TO DEVELOP. MAY SEE SOME LIGHT PRECIP OVER THE PLAINS TOWARD 12Z AS WEAK WARM ADVECTION CONTINUES...BUT COVERAGE LOOKS TOO LOW TO INCLUDE IN TAFS. ON WED...VFR THROUGH THE MORNING WITH TSRA DEVELOPING OVER THE MOUNTAINS BEGINNING 18Z. MOISTURE LEVELS AND INSTABILITY LOOK HIGHER WED AFTERNOON/EVENING...AND EXPECT GREATER COVERAGE OF STORMS...ESPECIALLY ALONG AND WEST OF I-25. WILL INCLUDE A VCTS MENTION ALL TAFS FROM ABOUT 19Z-21Z THROUGH 02Z-03Z...AND EXPECT MOST STORMS TO PRODUCE AT LEAST A BRIEF PERIOD OF MVFR CIGS/VIS DUE TO HEAVY RAINFALL. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...PETERSEN SHORT TERM...MW LONG TERM...KT AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1205 AM EDT WED JUL 29 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... ISSUED AT 306 PM EDT TUE JUL 28 2015 HOT AND HUMID CONDITIONS WILL PERSIST INTO WEDNESDAY. A COLD FRONT WILL THEN MOVE INTO CENTRAL INDIANA BRINGING SCATTERED SHOWERS AND THUNDERSTORMS. DRIER AIR WILL THEN MOVE IN TO END THE WORK WEEK. ANOTHER FRONT COULD BRING CHANCES FOR RAIN EARLY NEXT WEEK. && .NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/ ISSUED AT 935 PM EDT TUE JUL 28 2015 EARLIER THIS EVENING REMOVED PRECIP CHANCES FROM THE FORECAST AREA UNTIL LATE DURING THE OVERNIGHT PERIOD AS POP UP SHOWERS AND STORMS HAVE DISSIPATED ACROSS THE AREA. HRRR AND NAM STILL SHOW SOME STORMS CURRENTLY OVER IOWA MOVING INTO THE AREA LATE DURING THE OVERNIGHT. THUS MADE NO CHANGES TO POPS AFTER 6Z AND KEPT BRINGING THEM INTO THE NORTHWEST AFTER 8Z. OVERNIGHT LOWS IN THE 70S LOOK GOOD BASED ON DEWPOINTS RIGHT NOW IN THE LOW TO MIDDLE 70S AND NO REAL ADVECTION GOING ON. TIME HEIGHTS AND CROSSOVER TEMPERATURES ALONG WITH SREF PROBABILITIES ARE NOT SHOWING MUCH FOR FOG DEVELOPMENT SO WILL CONTINUE TO LEAVE THAT OUT OF THE FORECAST DESPITE THE AMPLE LOW LEVEL MOISTURE. PREVIOUS DISCUSSION FOLLOWS... FOCUS TURNS TO OTHER STORMS MOVING IN LATE. SOME MODELS SHOW STORMS SURVIVING AND MOVING IN LATE TONIGHT ALONG A PREFRONTAL FEATURE. WITH SOME WEAK LIFT AROUND...FEEL THAT THIS THREAT LOOKS GOOD ENOUGH TO GO SLIGHT CHANCE TO LOW END CHANCE POPS 08-12Z. WITH A HUMID AIRMASS IN PLACE A MODEL BLEND OF TEMPERATURES IN THE LOW TO MID 70S LOOKS GOOD FOR LOWS. && .SHORT TERM.../WEDNESDAY THROUGH FRIDAY/ ISSUED AT 306 PM EDT TUE JUL 28 2015 FOCUS IS ON CHANCES FOR RAIN WEDNESDAY. MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED. SOME UNCERTAINTY ON HOW CONVECTION WILL DEVELOP AHEAD OF THE A COLD FRONT ON WEDNESDAY. LINGERING MORNING CONVECTION OR ITS REMNANTS MAY HELP INHIBIT AFTERNOON CONVECTION. HOWEVER IF IT DIES QUICKLY OR DOES NOT MAKE IT INTO THE AREA...ATMOSPHERE WILL BE IN GOOD SHAPE FOR DEVELOPMENT OF AFTERNOON STORMS. GIVEN THE UNCERTAINTY DECIDED TO KEEP POPS BELOW LIKELY CATEGORY. TRIED TO TIME HOURLY POPS SO THAT BEST CHANCE OCCURS LATE MORNING/EARLY AFTERNOON NORTHWEST TO MID AFTERNOON SOUTHEAST WITH THE TIMING OF THE FRONT. STUCK WITH MODEL BLEND FOR HIGH TEMPERATURES WEDNESDAY...BUT THESE TOO MAY DEPEND ON HOW MORNING CONVECTION PLAYS OUT. APPARENT TEMPERATURES WILL BE NEAR HEAT ADVISORY CRITERIA SOUTHWEST...BUT THEE CONDITIONS LOOK TO BE RELATIVELY BRIEF. THIS PLUS THE UNCERTAINTY IN THE RAIN/CLOUD COVER LEADS TO NOT ISSUE A HEAT ADVISORY. KEPT SOME LOW END EVENING POPS WEDNESDAY AS THE FRONT MOVES THROUGH. AFTERWARD...HIGH PRESSURE WILL BUILD IN AND BRING DRY CONDITIONS INTO FRIDAY. GENERALLY STUCK WITH A MODEL BLEND FOR TEMPERATURES. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... ISSUED AT 231 PM EDT TUE JUL 28 2015 THE FORECAST FOR THIS WEEKEND IS LOOKING COMPLETELY DRY AS A LARGE AREA OF HIGH PRESSURE REMAINS IN CONTROL OVER THE REGION. ENSEMBLES SHOWING A WEAK COLD FRONT NOT MOVING ACROSS OUR REGION UNTIL EARLY MONDAY...WITH A SECONDARY AND EVEN WEAKER FRONT FOLLOWING ON TUESDAY. INCLUDED SOME LOW CHANCES FOR SHOWERS AND STORMS DURING EARLY NEXT WORK WEEK...WITH SLIGHTLY HIGHER POPS ACROSS THE NORTH...CLOSER TO THESE FEATURES. GENERALLY WENT WITH SUPERBLEND INITIALIZATION AS THIS GUIDANCE APPEARS TO BE IN LINE WITH THE CURRENT FORECAST. && .AVIATION /DISCUSSION FOR THE 290600Z TAF ISSUANCE/... ISSUED AT 1205 AM EDT WED JUL 29 2015 WITH LOWER 70S DEW POINTS...WOULD NOT RULE OUT MVFR FOG OVERNIGHT AT THE SMALLER AIRPORTS. HOWEVER...INCREASING MID DECK AND CONVECTIVE DEBRIS AHEAD OF A COLD FRONT...SHOULD KEEP THE VISIBILITY FROM DROPPING TO IFR OR WORSE SAVE PERHAPS A BRIEF TIME. RAPID REFRESH REFLECTIVITY PROGS AND RADAR TRENDS SUGGEST THE OWA CONVECTION COULD MAKE IT IN OUR WESTERN TAF SITES AFTER 10Z AND EASTERN ONES AFTER 12Z. THE COLD FRONT SHOULD MOVE THROUGH THE AREA AFTER 23Z WEDNESDAY AT LAF AND HUF AND 01Z THURSDAY AT IND AND BMG. THIS SHOULD PUT AN END TO ANY OTHER CONVECTION. WILL GO WITH A 2 HOUR MORNING MVFR THUNDERSTORM GROUP AND VCTS TO HANDLE THE POTENTIAL FOR AFTERNOON RE-DEVELOPMENT. WINDS WILL BE LIGHT AND VARIABLE TO CALM OVERNIGHT...SOUTHWEST AND WEST TO LESS THAN 10 KNOTS AFTER DAYBREAK AND NORTHWEST LESS THAN 10 KNOTS THIS EVENING...BEHIND THE FRONT. && .IND WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...50 NEAR TERM...50/CP SHORT TERM...50 LONG TERM....SMF AVIATION...MK
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
106 AM EDT Wed Jul 29 2015 ...Updated Aviation Discussion... ...Forecast Update... Issued at 830 PM EDT Tue Jul 28 2015 Issued another update to remove the pre-first period wording and to expand fog coverage. Soupy airmass in place along with winds expected to become light and variable soon should lead to at least areas of fog overnight. Quite the complex has formed to our west this evening, and the residual upper level disturbance may lead to an enhancement of showers storms toward daybreak, mainly west of the I-65 corridor. Thus will keep in the slight chances of storms we have there overnight. Issued at 545 PM EDT Tue Jul 28 2015 Did a grid update earlier this hour to account for current radar trends. Latest HRRR finally getting a handle on precip this afternoon, and it shows this precip decaying with sunset. Previous runs had the cells over central Illinois decaying immediately after model initialization, which has not occurred yet. Latest CIMSS NearCast does show the central part of our county warning area being a less likely place for storm development, and despite stronger outflows moving through that region, we only are seeing weak storms. Latest AMDAR data from a flight into SDF confirms this thinking, with a fairly strong cap above 600 mb that is limiting how tall the storms near SDF are getting. Despite that cap, the presence of these boundaries as well as a muggy airmass should keep non-severe storms forming over the next few hours until we can get the sun to set. Latest NAM still trying to show a wave of decaying storms coming in to our western forecast area toward daybreak. These would be from the cells now over Iowa as they round the top of the ridge over the mid MS valley. Made no changes to the daybreak period for now. .SHORT TERM (Now through Wednesday Night)... Issued at 325 PM EDT Tue Jul 28 2015 Scattered storms were ongoing across the area as of 19Z. Some storms were strong with lots of lightning, torrential rainfall, and gusty winds up to around 40 mph. Expect convection to continue through the evening hours as an upper level shortwave dropping SE out of IL keeps storms going or even enhances development this evening. With ample instability in place as well as DCAPE, high precipitable water values, and weak boundaries for storms to train along, a strong wind threat and localized flooding threat will continue through the evening hours. Storms should diminish through the late evening hours with the area becoming completely dry after midnight. Expect low temps in the low to mid 70s with some patchy fog/haze developing after midnight as it has done the past few mornings. For Wednesday, we`ll start the day with a dying complex of storms entering areas west of I-65. This morning batch should fizzle out or become just isld showers by mid morning. Some breaks in the clouds are expected during the morning and early afternoon hours allowing some instability to build. A cold front will approach the area Wed afternoon causing more convection to fire. Although morning clouds/precip may inhibit the environment somewhat and the front is pretty weak, we should still have enough forcing and instability to produce strong to marginally severe storms with strong winds, small hail, and torrential rainfall. Storms should persist through the evening before diminishing by late evening with the cold front passage. Highs for Wed should range through the upper 80s to lower 90s with heat index values in the lower 100s mainly west of I-65. The good news is any precip should provide relief from the heat tomorrow and there is a good chance for precip to occur 40-50%. Wed night low temps should range through upper 60s/lower 70s. .LONG TERM (Thursday through Tuesday)... Issued at 245 PM EDT Tue Jul 28 2015 The main forecast concern in the long term is temperatures as much of the extended forecast looks dry across the lower Ohio Valley. The start of the period /Thursday morning/ will feature a cold front bisecting the forecast area. A pool of high moisture along and ahead of the front combined with weak lift will support the chance of showers/storms during the morning hours across south-central Kentucky. The front then quickly drops into TN by 18z and in its wake, much drier and more pleasant conditions will build into the region. Plan on low humidity and more pleasant summer conditions Thursday afternoon through Friday as highs top out right around normal /mid to upper 80s/ and overnight lows will be in the low to mid 60s. Outside of scattered afternoon cumulus, skies look to be mostly sunny to sunny. A weak front approaches from the northwest on Saturday but will likely wash out before making it to the Ohio River. Humidity will slowly increase this weekend as dewpoints creep back up into the mid/upper 60s. Look for afternoon highs to gradually warm as well, approaching 90 degrees by Sunday. Going into next week, will continue to advertise a dry forecast as approaching fronts wash out or stall to the northwest. Some signals that a stronger front may make a push through the area mid to late week but model uncertainty is high. && .AVIATION (06Z TAF Update)... Updated 100 AM EDT Tue Jul 28 2015 Steamy conditions will persist overnight, with fog potential being the biggest near-term question. Rainfall Tue afternoon/evening was fairly unimpressive near the terminals, and visibilities didn`t drop too hard in the morning anyway. Temp/dewpoint spreads remain slightly wider than advertised by models, so it seems that MVFR should cover the visibilities around daybreak. Best chance of any IFR restriction seems to be in LEX, as cirrus should keep any fog at BWG in check. Next challenge is timing and impact of any convection as a cold front moves in late in the day. Morning should be high and dry as the storms over Iowa and northern Missouri struggle to organize into any kind of MCS that could dive at us early in the day. Hi-res models all point to mid/late afternoon for any T-storms, and there remains a hint that some of the are could get gapped. If a storm does directly affect an airport, there will be MVFR vis in rain, if not briefly IFR. Will carry a PROB30 group for that into early evening. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Update.........RJS Short Term.....AMS Long Term......ZT Aviation.......RAS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
151 AM EDT WED JUL 29 2015 .SYNOPSIS... HIGH PRESSURE REMAINS OFFSHORE THROUGH MIDWEEK...WITH THE NEXT COLD FRONT CROSSING THE AREA BY THURSDAY NIGHT. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... LATEST REGIONAL RADAR MOSAIC DEPICTS AREA OF SHOWERS PERSISTING OVER THE ERN VA PIEDMONT LATE THIS EVENING...REMAINING GENERALLY WEST OF THE LOCAL AREA. OTHERWISE...EARLIER SHOWERS/THUNDERSTORMS HAVE DISSIPATED OVER THE LOCAL AREA. SHORTWAVE VISIBLE ON GOES WV PROGGED TO DROP OVER ERN VA TONIGHT IN CONCERT WITH INCREASING WINDS ALOFT. A WARM/MOIST AIR MASS REMAINS IN PLACE OVER THE LOCAL AREA WITH DEWPOINTS IN THE 70S AND PWATS AROUND 2 INCHES. WILL MAINTAIN SLIGHT CHANCE-CHANCE POPS OVER THE PIEDMONT INTO CENTRAL VA AS RAP DEPICTS AN AXIS OF DEEP MOISTURE CONVERGENCE OVER THAT REGION. SKY AVERAGES PARTLY CLOUDY/MOSTLY CLOUDY INLAND AND MOSTLY CLEAR NE COUNTIES. LOWS IN THE LOW 70S. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... WEDNESDAY... UPPER LEVEL RIDGING CONTINUES TO EXPAND EASTWARD FROM THE SOUTHERN PLAINS. THIS WILL HELP TO LIMIT AFTN CONVECTION WHILE MAX TEMPS WARM A COUPLE OF DEGREES. HAVE CHC POPS (25-30%) ALONG AND WEST OF I-95. PARTLY SUNNY W/ HIGH TEMPS IN THE UPR 80S TO LOW 90S...WITH LOW/MID 80S AT THE BEACHES. MILD WED NIGHT W/ LOW TEMPS IN THE LOW/MID 70S. THURSDAY... UPR RIDGING RETROGRADES A BIT THURSDAY AS A TROUGH MOVES ACROSS THE GREAT LAKES AND PUSHES A COLD FRONT INTO THE MID-ATLANTIC REGION BY LATE IN THE DAY. DUE TO THE LATE ARRIVAL OF THE FRONT...CHC POPS (30-50%) WILL REMAIN ACROSS WESTERN AREAS DURING THE AFTN...LOWERING TO ~20% AT THE COAST. MAX TEMPS WILL REACH INTO THE UPR 80S TO LOW 90S...EXCEPT LOW/MID 80S AT THE IMMEDIATE COAST. THURSDAY NIGHT AND FRIDAY... THE COLD FRONT MOVES ACROSS THE FA THURSDAY NIGHT BEFORE STALLING ACROSS FAR SE VA AND THE EASTERN CAROLINAS ON FRIDAY. HAVE SOLID CHANCE POPS (30-50%) MOST AREAS WITH THE PASSAGE OF THE FRONT THRU MIDDAY FRI...THEN FOCUS CHC POPS ACROSS SE VA AND NE NC FRIDAY AFTN. DRY WX SHOULD RETURN TO NW AREAS BY LATE MORNING OR AFTERNOON. LOWS THU NIGHT IN THE 70S. HIGHS FRIDAY IN THE 80S TO AROUND 90. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... PATTERN BEGINS WITH A MID/UPPER LEVEL RIDGE CENTERED OVER THE SW CONUS AND AN UPPER LEVEL LOW PERSISTING ACRS HUDSON BAY CANADA. GFS/ECMWF INTO BETTER DECENT AGREEMENT THAT AN UPPER TROUGH AXIS WILL EXTEND SOUTH INTO THE GREAT LAKES SAT...THEN FLATTEN OUT SUN WITH A SHORTWAVE PUSHING ACRS THE MID ATLC BY MON. FRONT STALLS AND WEAKENS OVER FAR SRN VA/NC LATE FRI INTO THE WEEKEND. BEST CHC FOR PRECIP LOOKS TO BE ACRS THE FAR SOUTH/MAINLY NE NC THROUGH THE WEEKEND BUT EVEN HERE WILL ONLY GO WITH A 20-30% POPS/PRIMARILY FOR THE AFTN/EVENING TIMEFRAME (TAPERED TO 20% FAR SRN VA AND DRY ELSEWHERE). DID RAISE POPS A BIT FOR MON DUE TO THE SHORTWAVE MOVING THROUGH BUT NOT A LOT OF CONFIDENCE AS THIS IS 5-6 DAYS OUT SO WILL GENLY KEEP POPS ONLY AT 30-40% SOUTH TO 20% NORTH. KEEPING POPS AROUND 20% ALL AREAS TUE. TYPICAL SUMMERTIME TEMPERATURES CAN BE EXPECTED WITH HIGHS MAINLY RANGING FROM THE MID/UPPER 80S ALONG THE COAST TO THE UPPER 80S TO LOWER 90S INLAND. LOWS GENERALLY RANGING FROM THE MID 60S NW TO THE LWR 70S SE THROUGH THE PERIOD. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... UPR LEVEL RIDGING WILL EXPAND EWD FM THE SRN PLAINS TODAY. THIS WILL HELP TO LIMIT AFTN TSTMS FOR THE ERN HALF OF THE AREA (INCLUDING TAF SITES KSBY/KPHF/KORF/KECG). HOWEVER...THERE IS JUST ENOUGH MOISTURE AND ENERGY WRAPPING ARND THE UPR RIDGE TO KEEP VCSH AT KRIC (INCLUDING AREAS ALONG AND W OF INTERSTATE 95). OVERALL SHEAR REMAINS VERY WEAK...THEREFORE THE MAIN THREAT WITH AFTN/EVENING TSTMS WILL BE HEAVY RAINFALL CAUSING QUICK REDUCTIONS TO CIGS (MVFR) AND VSBYS (IFR). A COLD FRONT WILL THEN SLOWLY PUSH INTO AND ACRS THE MID ATLC REGION THU THRU FRI AFTN. THIS FRONT WILL PROVIDE SCTD TSTM CHCS AT ALL TAF SITES DURING THIS PERIOD. && .MARINE... WEAK SFC HIGH PRESSURE IS CENTERED OFF THE COAST WITH WEAK SFC TROUGHING INLAND ACRS THE PIEDMONT AND COASTAL PLAIN. S/SE WINDS AVG 10-15 KT THIS EVENING/OVERNIGHT...AND WILL DROP OFF TO S/SW 5-10 KT WED MORNING. MODELS SUGGEST THAT WINDS MAY BE A LITTLE STRONGER LATE WED AFTN/WED NIGHT AS SFC/LEE TROUGH OVER VA DEEPENS SLIGHTLY AND HELPS S/SE WINDS AVG AROUND 15 KT IN THE BAY. COULD BE A FEW HRS WORTH OF 20 KT GUSTS IN THE BAY BUT TOO MARGINAL TO CONSIDER ANY SCA HEADLINES FOR NOW. WAVES GENLY 1-2 FT IN THE BAY BUT WILL PROBABLY BUILD TO 2-3 FT WED EVENING. SEAS 2-3 FT. A WEAK COLD FRONT APPROACHES THE WATERS LATE THU...THEN STALLS SOUTH OF THE AREA BY LATE IN THE WEEK. S/SE WINDS AVG 10-15 KT...TURNING SSW THU NIGHT. NOT A STRONG COOL SURGE ON FRI AS WINDS SHIFT TO THE NORTH WITH THE FRONT DISSIPATING OVER SRN VA/ERN NC SO WILL KEEP WINDS IN THE 10-15 KT RANGE. FLOW GRADUALLY SHIFTS TO E/SE INTO THE WEEKEND WITH WAVES 1-2 FT/SEAS 2-4 FT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...JDM NEAR TERM...JDM/SAM SHORT TERM...JDM LONG TERM...LKB AVIATION...TMG MARINE...LKB/TMG
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 AM EDT WED JUL 29 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 418 AM EDT WED JUL 29 2015 FAIRLY IMPRESSIVE SURFACE AND UPPER LOW FOR LATE JULY IS LOCATED JUST TO THE SOUTH OF LAKE WINNIPEG EARLY THIS MORNING...AND IT IS KEEPING MUCH OF ITS ENERGY NEAR THE LOW IN MANITOBA. THIS HAS LED TO A FAIRLY UNEVENTFUL PASSAGE OF THE COLD FRONT DUE TO THE LACK OF ANY UPPER LEVEL SUPPORT/SHORTWAVES MOVING THROUGH THE AREA AND THE MID- LEVEL DRY AIR AND CAPPING SEEN ON RAP ANALYSIS SOUNDINGS. THERE WAS A THUNDERSTORM THAT MOVED NORTHEAST OUT OF NORTHWEST WISCONSIN EARLIER IN THE NIGHT BUT DISSIPATED OVER WESTERN LAKE SUPERIOR. HAVE SEEN SOME LIGHT SHOWER DEVELOPMENT OVER THE WESTERN U.P. OVER THE LAST 1-2HRS AND THEY ARE MOVING NORTHEAST WHILE THE FRONT SHIFTS THEM TO THE EAST. THERE HASN/T BEEN ANY LIGHTNING NOTED WITH THEM THUS FAR...LARGELY DUE TO THEM STRUGGLING TO GET ABOVE THE FREEZING LEVEL (HAVE PEAKED AROUND 15KFT). STILL THINK SOME THUNDER IS POSSIBLE AS THEY ALIGN WITH A THIN AREA OF 500 J/KG OF MUCAPE AHEAD OF THE FRONT AS SEEN ON THE SPC MESOSCALE ANALYSIS PAGE. THE COLD FRONT WILL CONTINUE TO THE EAST THIS MORNING AND EXIT THE AREA BY NOON. WILL CONTINUE TO SHOW SLIGHT CHANCE POPS RIGHT ALONG THE FRONT AS IT MOVES EAST THIS MORNING...BUT DON/T EXPECT ANYTHING MORE THAN AN ISOLATED SHOWER/THUNDERSTORM. HAVE SEEN A FAIRLY SIGNIFICANT DROP IN DEWPOINTS BEHIND THE FRONT...AS KIWD WENT FROM A 72 DEGREE DEWPOINT AT 535Z AND QUICKLY DROPPED TO 64 AT 615Z AND IS NOW AT 57 AT 735Z. BEHIND THE FRONT...THE DRY SLOT SEEN ON WATER VAPOR IMAGERY WILL MOVE THROUGH THE AREA AND LEAD TO AN AREA OF MOSTLY SUNNY START TO THE DAY OVER THE WEST. DO EXPECT THE AREA OF CLOUDS IN NORTHEAST ND AND NORTHWEST MN TO MOVE EAST INTO THE WESTERN CWA THIS AFTERNOON AND BE AIDED BY DIURNAL HEATING TO PRODUCE DIURNAL CU ON THE LEADING EDGE AND AHEAD OF THE CLOUDS INTO THE CENTRAL U.P. OVER THE EAST...AFTER A CLOUDY START TO THE DAY...EXPECT A PERIOD OF MOSTLY SUNNY SKIES AND THEN SOME DIURNAL CU IN AFTERNOON AND LINGERING INTO THE EVENING. HIGHS TODAY WILL BE IN THE UPPER 70S OVER THE WEST AND THE LOW-MID 80S OVER THE CENTRAL AND EAST. THE MAIN HAZARD BEHIND THE FRONT WILL BE THE GUSTY WEST-SOUTHWEST WINDS. THESE WINDS WILL BE AIDED BY THE TIGHT PRESSURE GRADIENT OVER THE NORTHWEST HALF OF THE CWA AND LARGELY OVER NORTHWESTERN LAKE SUPERIOR. HAVE ALREADY SEEN GUSTS TO 20-25KTS IMMEDIATELY BEHIND THE FRONT EARLIER IN THE NIGHT AND CLOSER TO THE LOW WINDS HAVE BEEN GUSTING TO 30-35KTS IN NORTHWEST MINNESOTA. THE AMPLE SUNSHINE THIS MORNING WILL HELP TO MIX INTO THE 25-40KT WINDS AROUND 925MB TO THE SURFACE...WITH THE STRONGEST WINDS OVER THE KEWEENAW PENINSULA. IN THAT AREA...WOULD EXPECT GUSTS TO AROUND 35KTS BY MID AFTERNOON AND THERE COULD BE A BRIEF PERIOD OF GUSTS TO 40KTS BY EARLY EVENING. DON/T THINK THERE WILL BE A LONG ENOUGH PERIOD FOR A WIND ADVISORY FOR THE KEWEENAW PENINSULA (NEED 39KTS)...SO WILL ISSUE AN SPS FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES TO HIGHLIGHT THE WINDY CONDITIONS FOR TODAY. THE REST OF THE U.P. WILL SEE WIND GUSTS OF 20- 30KTS...HIGHEST OVER THE WEST. WITH THE MUCH DRIER AIR MOVING INTO THE AREA...THINK DEWPOINTS WILL MIX OUT INTO THE UPPER 40S TO AROUND 50 OVER THE WEST/CENTRAL TODAY. WHILE TEMPERATURES WILL BE COOLER THAN YESTERDAY...RH VALUES WILL STILL FALL INTO THE 30S. THAT WILL LEAD TO AN ELEVATED RISK OF WILDFIRES ACROSS MUCH OF THE U.P. TODAY. SINCE THE RH VALUES WILL BE ABOVE RED FLAG CRITERIA...THIS SITUATION WOULD FALL UNDER AN RFD PRODUCT DUE TO THE FREQUENT GUSTS OVER 25 MPH. SINCE COORDINATION NEEDS TO BE DONE WITH FIRE WX USERS BEFORE ISSUANCE...WILL PASS ALONG TO DAY SHIFT TO COORDINATE POTENTIAL ISSUANCE. A SECONDARY TROUGH MOVES EAST ACROSS THE AREA TONIGHT. SOME CLOUDS ASSOCIATED WITH IT...LARGELY OVER LAKE SUPERIOR...BUT NOT EXPECTING ANY RAIN. THERE WILL STILL BE STRONG WINDS JUST ABOVE THE SURFACE AGAIN TONIGHT...WHICH WILL HELP TO KEEP THE WINDS FROM DECOUPLING. HAVE KEPT UP GUSTS OVER THE KEWEENAW PENINSULA (TO 20-30KTS) ...ESPECIALLY FOR THE EXPOSED LOCATIONS. OTHERWISE...THE REST OF THE AREA WILL SEE WINDS TURNING WESTERLY WITH GUSTS TO 10-20KTS (HIGHEST NORTH). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 455 AM EDT WED JUL 29 2015 THE OVERALL PATTERN AFFECTING THE AREA WILL NOT CHANGE MUCH THROUGH THE LONG TERM AS PERSISTENT CLOSED LOW NEAR HUDSON BAY WILL KEEP A BROAD TROUGH ENTRENCHED OVER MUCH OF ERN CANADA AND A BROAD RIDGE IS ANCHORED OVER THE WRN CONUS. BETWEEN THESE LARGE SCALE FEATURES A NW FLOW WILL DOMINATE THE GREAT LAKES REGION AS A SERIES OF MAINLY WEAK SHORTWAVES PASSING THRU BRING CHCS FOR PERIODIC LIGHT SHOWERS. TIMING OF THESE WEAK SHORTWAVES WILL LIKELY BE POORLY RESOLVED BY MODELS WHICH WILL MAKE FOR A TRICKY FCST IN THE LONG TERM. IT LOOKS LIKE TEMPERATURES WILL BE NEAR NORMAL THROUGH THE WEEKEND AND THEN TREND BELOW NORMAL TOWARD THE BEGINNING HALF OF NEXT WEEK AS A MID- LVL TROUGH BEGINS TO AMPLIFY INTO THE UPPER GREAT LAKES REGION. THU THROUGH FRI...MOST OF MODELS SHOW A WEAK SHORTWAVE MOVING THROUGH THE AREA TOWARD THU EVENING WITH ANOTHER WEAK SHORTWAVE MOVING THROUGH DURING THE DAY ON FRI. WITH SEVERAL OF THE MODELS SHOWING A FEW HUNDRED J/KG OF MLCAPE EACH DAY MAINLY DURING THE AFTERNOON/EVENING HRS WILL PROBABLY NEED TO MAINTAIN SLIGHT CHC POPS EACH DAY FOR ISOLD SHRA/TSRA. WITH LIMITED MOISTURE IN NW FLOW EXPECT ANY PCPN FROM ISOLD CONVECTION TO BE FAIRLY LIGHT. FRI NIGHT AND SAT...ANOTHER SHORTWAVE MOVING THROUGH DURING THIS TIME WILL WARRANT HAVING SLIGHT CHC POPS OVER MAINLY THE NW AND NE CWA INCLUDING LAKE SUPERIOR. TEMPERATURES THU THROUGH SAT WILL BE CLOSER TO NORMAL WITH HIGHS IN THE 70S TO LOWER 80S AND LOWS IN THE 50S TO LOWER 60S. MODELS HAVE TRENDED FARTHER NORTH WITH MORE SIGNIFICANT SHORTWAVE DUE TO MOVE IN SAT NIGHT INTO SUN SO HAVE BACKED OFF TO ONLY SLIGHT CHANCE POPS FOR THAT TIME FRAME. BEST LIFT WITH SHORTWAVE STAYS NORTH AND BETTER INSTABILITY AS INDICATED BY MODELS IS FARTHER SOUTH. TIMING OF SHORTWAVE AND ASSOC COLD FRONT FOR EARLY NEXT WEEK DIFFERS BTWN THE 00Z GFS AND 00Z ECMWF. THE ECMWF IS QUICKER BRINGING SYSTEM THROUGH SUN NIGHT INTO MON WHILE THE GFS DOESN/T BRING SYSTEM THRU UNTIL LATE MON INTO MON NIGHT. THIS SYSTEM MAY HAVE A BETTER CHC OF BRINGING MORE WIDESPREAD...ALTHOUGH LIGHT PCPN...BUT GIVEN UNCERTAINTY IN TIMING AT THIS POINT DON/T HAVE ANYTHING MORE THAN LOW CHC POPS. MODELS ADVERTISE TEMPS COOLING BELOW NORMAL TEMPS BEHIND THE FRONTAL SYSTEM ESPECIALLY BY TUE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 129 AM EDT WED JUL 29 2015 HIGH CLOUDS WILL BEGIN TO LOWER THIS EVENING RIGHT AHEAD AND ALONG A COLD FRONT CROSSING W TO E OVER THE AREA. THE FRONT IS CURRENTLY JUST TO THE WEST OF KIWD AND ALTHOUGH THERE MAY BE AN ISOLATED SHOWER OR THUNDERSTORM...CONFIDENCE WAS TOO LOW TO INCLUDE IN THE TAF. LLWS IS A CONCERN THROUGH THE EARLY MORNING HOURS TODAY AHEAD OF THE FRONT AS WINDS JUST ABOVE THE SFC CONTINUE AROUND 35KTS. EXPECT THE GUSTY WINDS TO MIX BETTER DURING THE DAY...LIMITING THE NEED FOR LLWS. EXPECT SIGNIFICANT CLEARING AND MIXING DIRECTLY BEHIND THE FRONT...WITH SOME SCT-BKN VFR CLOUDS ENCROACHING BY MID AFTERNOON. VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 AM EDT WED JUL 29 2015 A STRONG LOW PRESSURE SYSTEM FOR LATE JULY IS LOCATED NEAR LAKE WINNIPEG EARLY THIS MORNING AND IT WILL LIFT NORTHEAST INTO FAR NORTHERN ONTARIO TODAY. MEANWHILE...IT WILL SWEEP A COLD FRONT CURRENTLY OVER CENTRAL LAKE SUPERIOR EAST ACROSS THE REST OF THE LAKE THIS MORNING. BEHIND THE FRONT...SOUTHWEST WINDS WILL INCREASE THROUGH THE MORNING OVER THE WESTERN HALF OF THE LAKE AND PRODUCE GALES TO 35-40KTS. THERE COULD BE A FEW GUSTS IN THE 40-45KT RANGE TOWARDS ISLE ROYALE THIS AFTERNOON. THESE WINDS WILL DECREASE AND SHIFT TO THE WEST THIS EVENING AS THE FIRST IN A SERIES OF TROUGHS MOVE ACROSS LAKE SUPERIOR THROUGH SUNDAY MORNING (ASSOCIATED WITH THE SURFACE LOW SLOWLY DRIFTING OVER HUDSON BAY). THERE IS THE POTENTIAL FOR GALES OUT OF THE WEST-NORTHWEST TONIGHT BEHIND THE SECONDARY TROUGH AS THE PRESSURE GRADIENT REMAINS TIGHT OVER NORTHERN LAKE SUPERIOR. BUT EXPECT THE MARINE LAYER TO BE THE STRONGEST IN THAT AREA WITH THE WATER TEMPERATURES STILL IN THE UPPER 30S AND LOWER 40S. WILL ADD A MENTION OF GALE FORCE GUSTS FOR NOW. THE PRESSURE GRADIENT WILL GRADUALLY DECREASE THROUGH THE REST OF THE WEAK AS ADDITIONAL WEAK SURFACE TROUGHS MOVE SOUTHEAST ACROSS THE LAKE. EXPECT WINDS TO STAY BELOW 25KTS AFTER THURSDAY AND THROUGH THE WEEKEND. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 8 AM EDT /7 AM CDT/ THIS MORNING TO 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-240>242-263. GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR LSZ264. GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR LSZ245>247. GALE WARNING FROM 11 AM THIS MORNING TO 10 PM EDT THIS EVENING FOR LSZ243-244. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...VOSS AVIATION...07/SRF MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 AM EDT WED JUL 29 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 418 AM EDT WED JUL 29 2015 FAIRLY IMPRESSIVE SURFACE AND UPPER LOW FOR LATE JULY IS LOCATED JUST TO THE SOUTH OF LAKE WINNIPEG EARLY THIS MORNING...AND IT IS KEEPING MUCH OF ITS ENERGY NEAR THE LOW IN MANITOBA. THIS HAS LED TO A FAIRLY UNEVENTFUL PASSAGE OF THE COLD FRONT DUE TO THE LACK OF ANY UPPER LEVEL SUPPORT/SHORTWAVES MOVING THROUGH THE AREA AND THE MID- LEVEL DRY AIR AND CAPPING SEEN ON RAP ANALYSIS SOUNDINGS. THERE WAS A THUNDERSTORM THAT MOVED NORTHEAST OUT OF NORTHWEST WISCONSIN EARLIER IN THE NIGHT BUT DISSIPATED OVER WESTERN LAKE SUPERIOR. HAVE SEEN SOME LIGHT SHOWER DEVELOPMENT OVER THE WESTERN U.P. OVER THE LAST 1-2HRS AND THEY ARE MOVING NORTHEAST WHILE THE FRONT SHIFTS THEM TO THE EAST. THERE HASN/T BEEN ANY LIGHTNING NOTED WITH THEM THUS FAR...LARGELY DUE TO THEM STRUGGLING TO GET ABOVE THE FREEZING LEVEL (HAVE PEAKED AROUND 15KFT). STILL THINK SOME THUNDER IS POSSIBLE AS THEY ALIGN WITH A THIN AREA OF 500 J/KG OF MUCAPE AHEAD OF THE FRONT AS SEEN ON THE SPC MESOSCALE ANALYSIS PAGE. THE COLD FRONT WILL CONTINUE TO THE EAST THIS MORNING AND EXIT THE AREA BY NOON. WILL CONTINUE TO SHOW SLIGHT CHANCE POPS RIGHT ALONG THE FRONT AS IT MOVES EAST THIS MORNING...BUT DON/T EXPECT ANYTHING MORE THAN AN ISOLATED SHOWER/THUNDERSTORM. HAVE SEEN A FAIRLY SIGNIFICANT DROP IN DEWPOINTS BEHIND THE FRONT...AS KIWD WENT FROM A 72 DEGREE DEWPOINT AT 535Z AND QUICKLY DROPPED TO 64 AT 615Z AND IS NOW AT 57 AT 735Z. BEHIND THE FRONT...THE DRY SLOT SEEN ON WATER VAPOR IMAGERY WILL MOVE THROUGH THE AREA AND LEAD TO AN AREA OF MOSTLY SUNNY START TO THE DAY OVER THE WEST. DO EXPECT THE AREA OF CLOUDS IN NORTHEAST ND AND NORTHWEST MN TO MOVE EAST INTO THE WESTERN CWA THIS AFTERNOON AND BE AIDED BY DIURNAL HEATING TO PRODUCE DIURNAL CU ON THE LEADING EDGE AND AHEAD OF THE CLOUDS INTO THE CENTRAL U.P. OVER THE EAST...AFTER A CLOUDY START TO THE DAY...EXPECT A PERIOD OF MOSTLY SUNNY SKIES AND THEN SOME DIURNAL CU IN AFTERNOON AND LINGERING INTO THE EVENING. HIGHS TODAY WILL BE IN THE UPPER 70S OVER THE WEST AND THE LOW-MID 80S OVER THE CENTRAL AND EAST. THE MAIN HAZARD BEHIND THE FRONT WILL BE THE GUSTY WEST-SOUTHWEST WINDS. THESE WINDS WILL BE AIDED BY THE TIGHT PRESSURE GRADIENT OVER THE NORTHWEST HALF OF THE CWA AND LARGELY OVER NORTHWESTERN LAKE SUPERIOR. HAVE ALREADY SEEN GUSTS TO 20-25KTS IMMEDIATELY BEHIND THE FRONT EARLIER IN THE NIGHT AND CLOSER TO THE LOW WINDS HAVE BEEN GUSTING TO 30-35KTS IN NORTHWEST MINNESOTA. THE AMPLE SUNSHINE THIS MORNING WILL HELP TO MIX INTO THE 25-40KT WINDS AROUND 925MB TO THE SURFACE...WITH THE STRONGEST WINDS OVER THE KEWEENAW PENINSULA. IN THAT AREA...WOULD EXPECT GUSTS TO AROUND 35KTS BY MID AFTERNOON AND THERE COULD BE A BRIEF PERIOD OF GUSTS TO 40KTS BY EARLY EVENING. DON/T THINK THERE WILL BE A LONG ENOUGH PERIOD FOR A WIND ADVISORY FOR THE KEWEENAW PENINSULA (NEED 39KTS)...SO WILL ISSUE AN SPS FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES TO HIGHLIGHT THE WINDY CONDITIONS FOR TODAY. THE REST OF THE U.P. WILL SEE WIND GUSTS OF 20- 30KTS...HIGHEST OVER THE WEST. WITH THE MUCH DRIER AIR MOVING INTO THE AREA...THINK DEWPOINTS WILL MIX OUT INTO THE UPPER 40S TO AROUND 50 OVER THE WEST/CENTRAL TODAY. WHILE TEMPERATURES WILL BE COOLER THAN YESTERDAY...RH VALUES WILL STILL FALL INTO THE 30S. THAT WILL LEAD TO AN ELEVATED RISK OF WILDFIRES ACROSS MUCH OF THE U.P. TODAY. SINCE THE RH VALUES WILL BE ABOVE RED FLAG CRITERIA...THIS SITUATION WOULD FALL UNDER AN RFD PRODUCT DUE TO THE FREQUENT GUSTS OVER 25 MPH. SINCE COORDINATION NEEDS TO BE DONE WITH FIRE WX USERS BEFORE ISSUANCE...WILL PASS ALONG TO DAY SHIFT TO COORDINATE POTENTIAL ISSUANCE. A SECONDARY TROUGH MOVES EAST ACROSS THE AREA TONIGHT. SOME CLOUDS ASSOCIATED WITH IT...LARGELY OVER LAKE SUPERIOR...BUT NOT EXPECTING ANY RAIN. THERE WILL STILL BE STRONG WINDS JUST ABOVE THE SURFACE AGAIN TONIGHT...WHICH WILL HELP TO KEEP THE WINDS FROM DECOUPLING. HAVE KEPT UP GUSTS OVER THE KEWEENAW PENINSULA (TO 20-30KTS) ...ESPECIALLY FOR THE EXPOSED LOCATIONS. OTHERWISE...THE REST OF THE AREA WILL SEE WINDS TURNING WESTERLY WITH GUSTS TO 10-20KTS (HIGHEST NORTH). .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 333 PM EDT TUE JUL 28 2015 IMPACTS...MAIN IMPACTS WILL BE ASSOCIATED WITH GUSTY WINDS WED NIGHT AND THU. THE OVERALL PATTERN AFFECTING THE AREA WILL NOT CHANGE MUCH REGIONALLY THROUGH THE LONG TERM. A LOW PRESSURE SYSTEM OVER FAR NRN ONTARIO AT 00Z THU WILL MOVE TO HUDSON BAY BY 00Z FRI AND MEANDER OVER THE BAY INTO THE WEEKEND. THE LOW WILL THEN BEHIND THE CYCLE BACK TO THE W...POSSIBLY BRINGING AN UPPER TROUGH OVER THE AREA LATE THIS WEEKEND INTO NEXT WEEK. THE PRESSURE GRADIENT...AND THEREFOR WINDS...WILL BE TIGHTEST OVER THE AREA WED NIGHT...AND WILL GRADUALLY WEAKEN INTO SAT. WINDS GUSTS AT 00Z THU WILL RANGE FROM 30-35MPH OVER THE KEWEENAW TO 10-20MPH N/NE OF LAKE MICHIGAN. A TROUGH MOVES THROUGH WED NIGHT THAT MAY LOCALLY ENHANCE WINDS OVER/NEAR LAKE SUPERIOR...BUT WINDS WILL GENERALLY BE STRONGEST AT 00Z THU AND GRADUALLY DIMINISHING AFTER THAT. ANOTHER MOISTURE STARVED TROUGH OR TWO MOVES THROUGH ON THU...BUT WILL ONLY PROVIDE SOME INCREASED CLOUD COVER. A SHORTWAVE WITH LIMITED MOISTURE MOVES THROUGH THU NIGHT...WHICH JUSTIFIES SLIGHT CHANCE POPS AS MODELS SHOW LIGHT QPF AMOUNTS OVER MUCH OF THE AREA. FRI INTO SAT LOOKS DRY...ALTHOUGH THE 12Z/28 GFS DOES BRING A PRECIP PRODUCING SHORTWAVE INTO THE AREA FRI NIGHT. LEFT PRECIP OUT OF THE FORECAST SINCE THE PREVIOUS GFS RUN WAS DRY AND OTHER MODELS ARE DRY. TEMPERATURES THU THROUGH SAT WILL BE NEAR NORMAL WITH HIGHS IN THE 70S TO LOW 80S AND LOW IN THE 50S TO LOW 60S. MODELS SHOW A MORE SIGNIFICANT SHORTWAVE AND WIDESPREAD QPF SAT NIGHT INTO SUN SO WILL KEEP CHANCE POPS FOR THAT TIME FRAME. COOLER TEMPS COME IN WITH THAT UPPER TROUGH EARLY NEXT WEEK...BRINGING BELOW NORMAL TEMPS FOR A CHANGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 129 AM EDT WED JUL 29 2015 HIGH CLOUDS WILL BEGIN TO LOWER THIS EVENING RIGHT AHEAD AND ALONG A COLD FRONT CROSSING W TO E OVER THE AREA. THE FRONT IS CURRENTLY JUST TO THE WEST OF KIWD AND ALTHOUGH THERE MAY BE AN ISOLATED SHOWER OR THUNDERSTORM...CONFIDENCE WAS TOO LOW TO INCLUDE IN THE TAF. LLWS IS A CONCERN THROUGH THE EARLY MORNING HOURS TODAY AHEAD OF THE FRONT AS WINDS JUST ABOVE THE SFC CONTINUE AROUND 35KTS. EXPECT THE GUSTY WINDS TO MIX BETTER DURING THE DAY...LIMITING THE NEED FOR LLWS. EXPECT SIGNIFICANT CLEARING AND MIXING DIRECTLY BEHIND THE FRONT...WITH SOME SCT-BKN VFR CLOUDS ENCROACHING BY MID AFTERNOON. VFR CONDITIONS EXPECTED THROUGH THE FORECAST PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 AM EDT WED JUL 29 2015 A STRONG LOW PRESSURE SYSTEM FOR LATE JULY IS LOCATED NEAR LAKE WINNIPEG EARLY THIS MORNING AND IT WILL LIFT NORTHEAST INTO FAR NORTHERN ONTARIO TODAY. MEANWHILE...IT WILL SWEEP A COLD FRONT CURRENTLY OVER CENTRAL LAKE SUPERIOR EAST ACROSS THE REST OF THE LAKE THIS MORNING. BEHIND THE FRONT...SOUTHWEST WINDS WILL INCREASE THROUGH THE MORNING OVER THE WESTERN HALF OF THE LAKE AND PRODUCE GALES TO 35-40KTS. THERE COULD BE A FEW GUSTS IN THE 40-45KT RANGE TOWARDS ISLE ROYALE THIS AFTERNOON. THESE WINDS WILL DECREASE AND SHIFT TO THE WEST THIS EVENING AS THE FIRST IN A SERIES OF TROUGHS MOVE ACROSS LAKE SUPERIOR THROUGH SUNDAY MORNING (ASSOCIATED WITH THE SURFACE LOW SLOWLY DRIFTING OVER HUDSON BAY). THERE IS THE POTENTIAL FOR GALES OUT OF THE WEST-NORTHWEST TONIGHT BEHIND THE SECONDARY TROUGH AS THE PRESSURE GRADIENT REMAINS TIGHT OVER NORTHERN LAKE SUPERIOR. BUT EXPECT THE MARINE LAYER TO BE THE STRONGEST IN THAT AREA WITH THE WATER TEMPERATURES STILL IN THE UPPER 30S AND LOWER 40S. WILL ADD A MENTION OF GALE FORCE GUSTS FOR NOW. THE PRESSURE GRADIENT WILL GRADUALLY DECREASE THROUGH THE REST OF THE WEAK AS ADDITIONAL WEAK SURFACE TROUGHS MOVE SOUTHEAST ACROSS THE LAKE. EXPECT WINDS TO STAY BELOW 25KTS AFTER THURSDAY AND THROUGH THE WEEKEND. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 8 AM EDT /7 AM CDT/ THIS MORNING TO 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-240>242-263. GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR LSZ264. GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR LSZ245>247. GALE WARNING FROM 11 AM THIS MORNING TO 10 PM EDT THIS EVENING FOR LSZ243-244. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...TITUS AVIATION...07/SRF MARINE...SRF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
331 AM EDT WED JUL 29 2015 .NEAR TERM...(TODAY THROUGH TONIGHT) ISSUED AT 331 AM EDT WED JUL 29 2015 PERSISTENT HIGH PRESSURE HAS SHIFTED EAST OF MICHIGAN EARLY THIS MORNING AS A COLD FRONT APPROACHES FROM THE WEST. MID AND HIGH CLOUDS HAVE BEGUN TO INCREASE ALONG THE NE PERIPHERY OF THE CONVECTIVE CLOUD SHIELD GENERATED FROM THE MCS CURRENTLY IMPACTING IOWA...NRN MISSOURI AND NRN ILLINOIS. THIS CONVECTION IS FUELED BY A STRONG INSTABILITY AXIS (CAPES OF AROUND 3000 JOULES) AND 850 MB THETA E RIDGING PUNCHING THRU THE MISSISSIPPI VALLEY ATTM. FURTHER NORTH...OUR UPSTREAM RADARS SHOW A FEW SHOWERS AND EMBEDDED WEAK STORMS TRYING TO DEVELOP JUST EAST OF THE ARROWHEAD OF MINNESOTA OVER WRN LAKE SUPERIOR JUST AHEAD OF THE APPROACHING COLD FRONT. CONVECTION IS STRUGGLING DUE TO WEAK INSTABILITY (500 JOULES OR LESS) AND VERY LIMITED MOISTURE. LATEST NAM12...RAP13 AND HRRR ALL SUGGEST THE FOCUS FOR MEANINGFUL CONVECTIVE DEVELOPMENT WILL STAY SOUTH OF OUR CWA THRU TODAY WHERE STRONGER INSTABILITY AND MUCH BETTER MOISTURE WILL RESIDE. NORTHERN MICHIGAN IS ONCE AGAIN LOOKING AT THE PROSPECT THAT THE MAJORITY OF OUR CWA MAY MISS OUT ON AN OPPORTUNITY FOR SOME MUCH NEEDED RAIN TODAY. STILL...CHANCE POPS WILL REMAIN IN ORDER THRU THE DAY...WITH THE EXPECTATION THAT A NARROW LINE OF SCATTERED SHOWERS WITH SOME EMBEDDED THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD FRONT. WILL MAKE SOME MINOR TIMING ADJUSTMENTS TO THIS BAND OF PRECIP AS IT SLOWLY MOVES THRU OUR CWA TODAY...BUT WILL CERTAINLY KEEP POPS IN THE CHANCE CATEGORY. NO REAL CHANCE FOR STRONG TO SEVERE STORMS GIVEN LIMITED INSTABILITY AND MOISTURE AND UNIMPRESSIVE WIND FIELDS AHEAD OF THE FRONT. EXPECT ANOTHER VERY WARM DAY FOR NORTHERN MICHIGAN...BUT NOT AS WARM AS IT HAS BEEN THE PAST FEW DAYS. HIGH TEMPS WILL WARM WELL INTO THE 80S...BUT SHOULD REFRAIN FROM REACHING INTO THE 90S. OVERNIGHT LOWS WILL COOL BACK INTO THE 60S. && .SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT) ISSUED AT 331 AM EDT WED JUL 29 2015 (7/30)THURSDAY...WITH THE FRONTAL PASSAGE TODAY, THE TEMPERATURES FALL BACK TO NORMAL FOR THURSDAY. THERE ARE TWO CONCERNS FOR THE DAY AND INTO THE NIGHT. 1) CLOUD COVER, ESPECIALLY NEAR ANJ. THE 850 MB RH IS AROUND 90%, AND WITH THE 850 MB TEMPERATURES NEAR +10C, NEAR E UPPER, IT COULD BE CLOUDIER. WHICH LEADS TO 2) TEMPERATURES COULD END UP COOLER IF THERE ARE MORE CLOUDS IN E UPPER AND EVEN PARTS OF THE N LOWER IF THE CLOUDS MAKE IT DOWN FAR ENOUGH SOUTH, BUT THAT SEEMS ONLY TO ABOUT M-32 AT THE MOST. SOUTH OF M-32, HOWEVER, THERE IS A DIFFERENT CONCERN, FIRE WEATHER. WILL EXPECT THAT THE HIGH TEMPERATURES WILL REMAIN OVER 75F (CIPS ANALOG GUIDANCE SHOWS 70% AT THE TEMPERATURES>75F). WINDS WILL BE AROUND 15MPH AT THE 20FT LEVEL (SUSTAINED), WITH THE RH AROUND 30- 35%. AND WITH THE EXTENDED DRY PERIOD, WILL BE GOING WITH THE ELEVATED FIRE DANGER. (7/31)FRIDAY...THE DISCUSSION FOR THURSDAY COULD VERY WELL FIT FOR FRIDAY AS WELL, EXCEPT THAT THERE IS A WEAK SFC LOW TRYING TO MOVE INTO THE REGION AS THE 500 MB LOW SINKS A LITTLE MORE SOUTH AND BEGINS TO COOL THINGS DOWN A BIT. AGAIN THE COOLEST, PROBABLY CLOUDIEST AREA WILL BE NORTH OF M-32, WITH THE SOO DROPPING INTO THE LOWER 70S FOR HIGHS POSSIBLY. LOOKS LIKE WE ARE STILL AROUND 80S SOUTH OF M-32, AND WINDS WILL BE AGAIN BE CLOSE TO 15 MPH AT 20FT, SO THERE IS AN ELEVATED FIRE DANGER RISK, ALTHOUGH THE RH MAY NOT BE AS BAD THURSDAY. HOWEVER, IT WILL STILL BE AN ISSUE. && .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 331 AM EDT WED JUL 29 2015 WITH THE 500 MB LOW JUST NORTH OF JAMES BAY, WE GO BACK TO THE PATTERN THAT WE`VE HAD OVER N MICHIGAN THE LAST 2 YEARS WITH COOLER THAN NORMAL TEMPERATURES AND POSSIBLY SHOWERY CONDITIONS, BUT NOTHING APPRECIABLE, AT LEAST FOR THE TIME BEING. CIPS ANALOGS FALL RIGHT IN LINE WITH THE MEX NUMBERS AS WELL AS THE ECMWF IDEAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 100 AM EDT WED JUL 29 2015 OVERALL CONDITIONS WILL REMAIN VFR AT ALL NRN LWR MICHIGAN TAF SITES THRU WEDNESDAY NIGHT. A COLD FRONT WILL SWEEP THRU THE REGION TODAY. LIMITED MOISTURE AND ONLY WEAK INSTABILITY ALONG AND AHEAD OF THE FRONT WILL RESTRICT POPS TO ONLY CHANCE. EXPECT A BAND OF SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS WILL SLOWLY PUSH FROM WEST TO EAST THRU NRN LWR MICHIGAN THROUGHOUT THE DAY. AT THIS POINT...SHORT TERM MODELS ARE LEANING TOWARD DIMINISHED COVERAGE...THUS WILL HANDLE WITH VCSH IN THE TAFS FOR NOW. SOUTH WINDS UNDER 10 KTS WILL SHIFT TO THE WEST IN THE WAKE OF THE FRONT AND WILL INCREASE TO 10 TO 15 KTS...WITH A FEW HIGHER GUSTS POSSIBLE. && .MARINE... ISSUED AT 331 AM EDT WED JUL 29 2015 CHANCES OF SHOWERS AND STORMS WILL INCREASE FROM WEST TO EAST TODAY AS A COLD FRONT SWINGS THROUGH NORTHERN MICHIGAN. WINDS AND WAVES WILL APPROACH SCA CRITERIA THIS AFTERNOON AND THIS EVENING AS WINDS SHIFT TO THE WEST AND STRENGTHEN BEHIND THE COLD FRONT. AT THIS POINT...EXPECT CONDITIONS WILL FALL JUST SHORT OF CRITERIA. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ NEAR TERM...MLR SHORT TERM...JSL LONG TERM...JSL AVIATION...MLR MARINE...MLR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
330 AM EDT WED JUL 29 2015 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/MARINE .SYNOPSIS... ISSUED AT 330 AM EDT WED JUL 29 2015 SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A COLD FRONT CROSSES THE REGION. GUSTY WESTERLY WINDS BEHIND THE FRONT WILL USHER IN MORE COMFORTABLE LESS HUMID AIR FOR THE REMAINDER OF THE WEEK ALTHOUGH HIGHS WILL REMAIN IN THE LOWER TO MID 80S. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 ISOLATED SHOWERS HAVE DEVELOPED OVERNIGHT ON THE LEADING EDGE OF THE HIGHER PRECIPITABLE WATER AROUND TWO INCHES MOVING IN FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. SUSPECT COVERAGE OF SHOWERS WILL REMAIN RATHER LIMITED THIS MORNING ACROSS SW LWR MI AS MORE EXPANSIVE AREA OF CONVECTION IMPACTS IOWA AND ILLINOIS. OUR BEST PROSPECTS FOR BETTER COVERAGE OF STORMS WILL BE THIS AFTERNOON EAST OF HIGHWAY 131 WHERE SB CAPES NEAR 1500 J/KG ARE PROGGED JUST AHEAD OF THE FRONT. RUC FCST SNDGS EXHIBIT STEEP LOW LEVEL LAPSE RATES WITH SFC TO 3 KM AROUND 8.5C NEAR JXN. BASED ON THE HIGH PWAT VALUES OF UP TO 2.25 INCHES WE WILL HAVE TO WATCH OF THE POSSIBILITY OF SOME TORRENTIAL RAINFALL AND POSSIBLY A LOCALIZED WET MICROBURST DAMAGING WIND EVENT. CONVECTION ENDS FROM WEST TO EAST 18Z-22Z WITH THE PASSAGE OF THE FRONT THEN DECREASING CLOUDS AND FALLING SFC DEW PTS EXPECTED. BREEZY CONDITIONS EXPECTED THURSDAY ONCE DEEPER MIXING COMMENCES. SOME GUSTS TO 30 MPH WILL BE POSSIBLE IN THE AFTERNOON. HAVE KEPT FRIDAY DRY FOR NOW ALTHOUGH SOME SMALL POPS MAY NEED TO BE ADDED IN LATER FCSTS AS NEXT WEAK FRONT/TROUGH DROPS SOUTH. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 THERE HAS NOT BEEN MUCH CHANGE OVER THE THE PAST FEW DAYS WITH REGARD TO THE EXPECTED PATTERN. WE CONTINUE TO EXPECT LITTLE TO NO RAIN THROUGH SAT...BEFORE AN UNSETTLED WEATHER PATTERN TAKES SHAPE LATER THIS WEEKEND AND INTO NEXT WEEK. WE HAVE CONTINUED WITH A DRY FCST FOR THE FRI NIGHT AND SAT TIME FRAME FOR NOW. WE WILL SEE WHAT IS LEFT OF THE WEAKENING COLD FRONT TRYING TO MOVE THROUGH ON FRI SLIP SE OF THE AREA FRI EVENING. WE CAN NOT RULE OUT A SHOWER DEVELOPING NEAR THIS FRONT...HOWEVER THE CHC IS LOW ENOUGH TO LEAVE OUT OF THE FCST FOR THE TIME BEING. A LACK OF MOISTURE WITH THE FRI FRONT WILL ONLY DIMINISH BY SAT AS THE FRONT MOVES OUT. THERE IS NOT REALLY SIGNIFICANTLY COOLER AIR BEHIND THIS...SO WE CONTINUE TO EXPECT HIGHS AROUND 80. THE CHCS OF RAIN DOES GO UP ON SUN...AND WILL CONTINUE THROUGH THE END OF THE PERIOD ON TUE. THE AREA WILL BE UNDER THE INFLUENCE OF BROAD LONG WAVE TROUGHING CENTERED WELL NORTH IN CANADA. WE WILL SEE THE JET CORE DROP A LITTLE FURTHER SOUTH WITH A TRAIN OF SHORT WAVES HELPING THIS CAUSE. BEING CLOSER TO THE JET...WE WILL HAVE MORE OF AN OPPORTUNITY FOR THE SHORT WAVES TO DIRECTLY IMPACT THE AREA. WE WILL ALSO SEE THE LOW LEVEL FLOW BECOME A LITTLE MORE FAVORABLE TO BRING SUFFICIENT MOISTURE TO THE AREA FOR RAIN. EXACT TIMING OF THE SHORT WAVES WILL BE PROBLEMATIC AS IS USUAL IN A PATTERN LIKE THIS. TEMPERATURES DO NOT LOOK TO BE TOO BAD IN THIS PATTERN. THE UNSEASONABLY COOL AIR WILL REMAIN JUST NORTH OF THE STATE...NORTH OF THE JET CORE. WE WILL SEE AVERAGE TO JUST SLIGHTLY BELOW AVERAGE TEMPS DURING THIS PERIOD FOR OUR AREA. THIS EQUATES TO HIGHS GENERALLY AROUND 80 AND LOWS AROUND 60. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 149 AM EDT WED JUL 29 2015 OUR MAIN FOCUS WITH THE 06Z FCST IS THE POTENTIAL OF SHOWERS AND/OR STORMS WITH A FRONT THAT WILL MOVE THROUGH TODAY. WE HAVE ACCOUNTED FOR A COUPLE POP UP SHOWERS NEAR KMKG FOR THE FIRST HOUR OF THE VALID FCST PERIOD. THESE WILL PRODUCE SOME LOCAL MVFR IN RAIN ESPECIALLY SOUTH OF KMKG...BUT WILL MOVE OUT QUICKLY AND WILL LIKELY NOT HIT THE OTHER SITES. WE EXPECTED A SCT LINE OF SHOWERS TO FORM WEST OF THE AREA TOWARD 12Z AND THEN SHIFT EAST THROUGH THE MORNING. NOT SURE ALL OF THE SITES WILL BE DIRECTLY HIT...SO WE HAVE USED A VCSH TO COVER THIS POTENTIAL. IF A SITE GETS HIT BY A SHOWER...SOME MVFR OR EVEN BRIEF IFR WILL BE POSSIBLE. SOME OF THE SHOWERS COULD BE STORMS TOWARD KLAN AND KJXN THIS AFTERNOON BEFORE EVERYTHING MOVES OUT OF THE AREA BY AROUND 22Z. SOME GUSTY WINDS WILL BE POSSIBLE RIGHT BEHIND THE FRONT/SHOWERS. THE WINDS WILL DIMINISH TOWARD SUNSET WITH CLEARING SKIES. && .MARINE... ISSUED AT 330 AM EDT WED JUL 29 2015 CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA LATE TONIGHT AND EARLY THURSDAY DUE TO STRONG WESTERLY FLOW BEHIND THE COLD FRONT. THIS WILL NEED TO BE MONITORED. THIS SITUATION COULD ALSO SUPPORT BEACH HAZARD STATEMENTS ESPECIALLY CONSIDERING THE CURRENT WARM WATER TEMPERATURES AND OVERALL ATTRACTIVE BEACH CONDITIONS SUPPORTIVE OF A HIGH BEACH POPULATION. && .HYDROLOGY... ISSUED AT 1250 PM EDT TUE JUL 28 2015 RIVER LEVELS ARE FALLING AND WELL BELOW BANKFULL. WITH UNDER A HALF INCH OF PRECIPITATION EXPECTED INTO NEXT WEEK... THESE CONDITIONS SHOULD CONTINUE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...NJJ AVIATION...NJJ HYDROLOGY...63 MARINE...MEADE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 AM CDT WED JUL 29 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT WED JUL 29 2015 FOR THE MAJORITY OF THE CWA (ESPECIALLY NEB ZONES)...THIS SHOULD BE A PRETTY STRAIGHTFORWARD NEXT 24 HOURS...WITH A CONTINUED EXPECTATION OF DRY CONDITIONS AND SEASONABLY PLEASANT TEMPS/DEWPOINTS...ALTHOUGH IT MAY BE A SOMEWHAT CLOUDIER DAY THAN PREVIOUSLY THOUGHT. HOWEVER...THINGS GET A BIT TRICKIER SOUTHWARD INTO KS ZONES (ESPECIALLY OUR BOTTOM-MOST 3 COUNTIES)...AS THERE ARE SOME MODELS (FOR EXAMPLE THE GFS) SUGGESTING THAT THIS AREA WILL BE BRUSHED BY THE FAR NORTHERN EDGES OF SOMEWHAT BETTER SHOWER/WEAK THUNDERSTORM POTENTIAL THAT SHOULD MAINLY FOCUS JUST SOUTH OF THE CWA...ESPECIALLY TONIGHT. THAT BEING SAID...OTHER MODELS INCLUDING SIMULATED REFLECTIVITY FROM 4KM WRF/ARW RUNS (INCLUDING THE OFTEN-RELIABLE NSSL WRF) ARE MORE SUPPORTIVE OF THESE MEASURABLE RAIN CHANCES REMAINING JUST SOUTH OF THE CWA...ALBEIT A RATHER CLOSE CALL. TO MAKE A LONG STORY SHORTER...CONSIDERED ADDING A FORMAL SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS TO PARTS OF OUR KS COUNTIES FOR MUCH OF THIS TIME FRAME...BUT GIVEN THE MIXED MESSAGES IN THE MODEL WORLD...AND ALSO CONSIDERING THAT WE HAD BEEN CONSISTENTLY ADVERTISING A "DRY" WEDNESDAY-WEDNESDAY NIGHT FORECAST CWA-WIDE THESE PAST FEW DAYS...OPTED TO TAKE A "MIDDLE GROUND" APPROACH FOR NOW BY SIMPLY INSERTING A "SLIGHT CHANCE OF SPRINKLES" INTO OUR FAR SOUTHERN AREAS. THE INTENDED MESSAGE HERE IS THAT ALTHOUGH WE CONTINUE TO DOWNPLAY PRECIP CHANCES...THE SPRINKLE MENTION BETTER IMPLIES THAT CHANCES ARE NOT TRULY "ZERO" EITHER. OBVIOUSLY THE NEXT FEW SHIFTS WILL HAVE TO MONITOR THE LATEST TRENDS JUST IN CASE PRECIP CHANCES (POPS) AND POSSIBLY THUNDERSTORM POTENTIAL MAY NEED BEEFED UP A BIT IN THIS TRICKY SOUTHERN AREA. TAKING A LOOK AT THE HERE AND NOW AS OF 08Z/3AM: WE ARE ALREADY IN THE MIDST OF A "CLOSE CALL" REGARDING SHOWER/THUNDERSTORM CHANCES IN OUR FAR SOUTHERN CWA...AS A FAIRLY CONCENTRATED AXIS OF SHOWERS /NON-SEVERE STORMS EXTENDING FROM NORTHEAST-CENTRAL KS IS JUST BARELY REMAINING OUTSIDE OUR CWA FOR THE MOST PART. THIS CONVECTION IS FOCUSED SLIGHTLY NORTH OF THE SYNOPTIC SURFACE COLD FRONT POSITIONED OVER SOUTHERN AND EAST-CENTRAL KS...AND IS LARGELY TIED TO AN AXIS OF LOW-MID LEVEL CONVERGENCE/FRONTOGENESIS IN THE 850-700MB LAYER. NOT SURPRISINGLY...THE NORTHERN FRINGE OF THIS CONVECTION IS ALIGNED ALMOST PERFECTLY WITH THE NORTHERN FRINGES OF A VERY SLOWLY SOUTHWARD-SINKING ELEVATED INSTABILITY AXIS...WHICH CLEARED THE VAST MAJORITY OF THE CWA BEHIND THE COLD FRONTAL PASSAGE DURING THE PAST 24 HOURS. IN THE BIGGER PICTURE OF THE MID-UPPER LEVELS...WATER VAPOR SATELLITE AND THE LATEST MODEL DATA DEPICT LIMITED LARGE-SCALE FORCING OVER THE CENTRAL PLAINS...AS THE LOCAL REGION IS SANDWICHED BETWEEN ANTICYCLONIC FLOW ASSOCIATED WITH THE SOUTHERN PLAINS SUBTROPICAL HIGH...AND THE SOUTHERN EDGES OF STRONGER WESTERLY FLOW ASSOCIATED WITH THE VIGOROUS CLOSED LOW PRESSURE SYSTEM SLOWLY DEPARTING NORTHEAST ACROSS THE MANITOBA/ONTARIO BORDER AREA. HOWEVER...THERE IS EVIDENCE OF A SUBTLE DISTURBANCE PASSING NORTHEAST THROUGH SOUTHWEST KS ASSOCIATED WITH A CLUSTER OF CONVECTION NEAR DODGE CITY. WHILE 11-3.9 MICRON SATELLITE IMAGERY HAS REVEALED A LARGELY CLEAR NIGHT THUS FAR OVER MUCH OF THE CWA...AT LEAST A THIN VEIL OF HIGH CLOUDS IS INCREASINGLY SPREADING NORTHEAST INTO THE CWA FROM THE SOUTHWEST KS CONVECTION. AT THE SURFACE...THINGS ARE LARGELY PLAYING OUT AS EXPECTED TONIGHT...WITH THE SOUTHEASTERN REACH OF BROAD HIGH PRESSURE CENTERED OVER THE NORTHERN ROCKIES PROVIDING VERY LIGHT/MAINLY NORTHERLY BREEZES TO THE LOCAL AREA. THIS HIGH PRESSURE AXIS...COMBINED WITH THE WELCOMED PRESENCE OF NOTICEABLY DRIER AIR MARKED BY DEWPOINTS MAINLY IN THE 50S...HAS ALLOWED TEMPS TO FALL SLIGHTLY BELOW LATE-JULY NORMALS IN MOST AREAS...AND ULTIMATELY EXPECT OVERNIGHT LOWS TO RANGE FROM MID 50S NORTHWEST...NEAR 60 CENTRAL AND MID-60S SOUTH. NOW LOOKING AHEAD FORECAST-WISE: EARLY THIS MORNING (THROUGH 7AM): OTHER THAN A CONTINUED GRADUAL INCREASE IN HIGH CLOUDS SPREADING IN FROM THE SOUTHWEST...LITTLE CHANGE FROM THE CURRENT SITUATION EXPECTED. GIVEN THAT IT APPEARS THAT THE EXTREME SOUTHERN FRINGES OF THE CWA WILL CONTINUE TO BARELY MISS OUT ON THE CENTRAL-NORTHEAST KS CONVECTION...WILL BE REMOVING THE PREVIOUSLY-EXISTING SLIGHT CHANCE OF SHOWERS/STORMS IN OUR FAR SOUTH FOR THE PRE-DAWN HOURS. TODAY (7AM-7PM): SEE THE OPENING PARAGRAPH ABOVE FOR THE BASIC REASONING BEHIND INTRODUCING SPRINKLE POTENTIAL INTO OUR FAR SOUTHERN CWA IN KS. HOWEVER...BARRING AN UNEXPECTED NORTHWARD SHIFT IN THE ONGOING EARLY MORNING CONVECTION IN CENTRAL KS...PLAN ON MAINTAINING A THUNDERSTORM-FREE FORECAST GOING FORWARD INTO THE OFFICIAL DAYTIME FORECAST PERIOD. AGAIN...FOR THE MAJORITY OF THE CWA (ESSENTIALLY NEB ZONES)...CONFIDENCE IS STILL HIGH ENOUGH IN A DRY DAY TO PRECLUDE EVEN A SPRINKLE MENTION. THAT BEING SAID THOUGH...THE LAST FEW HRRR RUNS ACTUALLY DO TRY TO DROP A FEW SPRINKLES OUT OF AN INCREASING MID LEVEL CLOUD DECK...BUT WILL LARGELY IGNORE THIS FOR NOW WITH VERY LITTLE SUPPORT FROM OTHER MODELS AND GIVEN THAT THIS LIMITED MOISTURE IS LARGELY AT/ABOVE 600MB. IN THE MID-UPPER LEVELS...SEASONABLY STRONG WESTERLY FLOW PERSISTS OVERHEAD...WITH HINTS OF A SUBTLE DISTURBANCE PASSING THROUGH THE CWA...POSSIBLY INCLUDING THE REMNANTS OF THE AFOREMENTIONED SOUTHWEST KS ONE. MEANWHILE...THE NORTHERN EDGES OF THE ELEVATED INSTABILITY AXIS OVER KS SHOULD LARGELY STALL OUT JUST SOUTH OF THE CWA IN A WEST-T0-EAST FASHION. ALTHOUGH DO NOT HAVE A GREAT FEEL FOR CLOUD COVER TODAY...BEEFED UP SKY COVER PERCENTAGES SOLIDLY INTO PARTLY CLOUDY TERRITORY MOST AREAS FOR MOST OF THE DAY...AND THERE COULD EASILY BE PERIODS OF MOSTLY CLOUDY TOO...ESPECIALLY IF THE NAM IS CORRECT IN DEPICTING A FAIRLY WIDESPREAD COVERAGE OF MID-HIGH CLOUDS DEVELOPING IN RESPONSE TO THE AFOREMENTIONED WEAK DISTURBANCE(S) PASSING THROUGH. AT THE SURFACE...BROAD HIGH PRESSURE WILL PASS EASTWARD OVER THE HEART OF THE CWA...PROMOTING NOT ONLY LIGHT BREEZES THAT WILL LARGELY AVERAGE UNDER 10 MPH...BUT ALSO A GRADUALLY VARYING DIRECTION AS MANY PLACES SEE A TRANSITION FROM NORTHERLY TO EASTERLY TO SOUTHERLY BY LATE IN THE DAY. TEMP-WISE...WOULD NOT BE SURPRISED IF INCREASING CLOUDS HOLD THINGS BACK A TOUCH AND DID DROP SOME AREAS (INCLUDING TRI-CITIES) 1-2 DEGREES FROM PREVIOUS FORECAST...BUT OVERALL STILL CALLING FOR MOST OF THE CWA TO TOP OUT IN THE 82-85 RANGE...WHICH COMBINED WITH LIGHT WIND AND DEWPOINTS LARGELY IN THE 50S SHOULD MAKE FOR A VERY COMFORTABLE LATE JULY DAY. TONIGHT (7PM-7AM): AGAIN...SEE OPENING PARAGRAPH FOR FURTHER INSIGHT INTO THE DECISION TO ADD SPRINKLE POSSIBILITY INTO PARTS OF KS ZONES. ALTHOUGH MODEL DISCREPANCY CONTINUES REGARDING NORTHERN KS PRECIP POTENTIAL...ITS WORTH NOTING THAT THE VERY LATEST 06Z NAM HAS BACKED OFF THE NORTHWARD EXTENT OF SHOWER/THUNDERSTORM POTENTIAL...NOW KEEPING OVERNIGHT CONVECTION JUST SOUTH OF THE CWA (MUCH THE SAME PLACEMENT AS THE ONGOING ACTIVITY). IN THE MID-UPPER LEVELS TONIGHT...FLOW OVER THE CWA STARTS TO TURN EVER-SO-SLIGHTLY NORTHWESTERLY...IN RESPONSE TO THE SOUTHERN PLAINS RIDGE STARTING TO RETROGRADE WESTWARD A BIT. WHILE FAIRLY SUBTLE LOW-MID LEVEL LIFT/CONVERGENCE IS EXPECTED TO PROMOTE "SOME" COVERAGE OF SHOWERS/STORMS MAINLY JUST SOUTH OF THE CWA...THE VAST MAJORITY OF THE LOCAL AREA SHOULD REMAIN VOID OF EVEN SPRINKLES...WITH A LIKELY DECREASE IN MID-HIGH LEVEL CLOUDS AS WELL FROM THE DAYTIME...THUS PROMOTING MOSTLY CLEAR SKIES ESPECIALLY NORTH OF THE STATE LINE. AT THE SURFACE...LIGHT BREEZES WILL CONTINUE IN THE PRESENCE OF BROAD HIGH PRESSURE...BUT LIKELY TAKING ON MORE OF A SOUTHERLY AND/OR WESTERLY COMPONENT. ALL IN ALL...LOW TEMPS ACROSS MOST OF THE CWA MAY END UP BEING VERY SIMILAR TO THOSE OBSERVED THIS MORNING...BUT FOR NOW WILL AIM MOST PLACES VERY SLIGHTLY WARMER...WITH MOST OF THE CWA BOTTOMING OUT SOMEWHERE IN THE 58-63 RANGE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 400 AM CDT WED JUL 29 2015 AFTER A VERY NICE WEDNESDAY WE WILL WARM RIGHT BACK UP INTO THE UPPER 80S TO LOWER 90S FOR THURSDAY THROUGH THE WEEKEND AND INTO NEXT MONDAY...BEFORE PERHAPS ANOTHER COOL DOWN NEXT TUESDAY. WE DO HAVE SEVERAL RAIN CHANCES...BUT CONFIDENCE IN SEEING PRECIPITATION IS NOT THAT HIGH ON ANY GIVEN DAY. MOST LOCATIONS WILL LIKELY END UP DRY THROUGH FRIDAY...BUT WE WILL SEE AT LEAST A FEW MORE CHANCES OF RAIN THEREAFTER. THURSDAY AND FRIDAY...THE HUMIDITY WILL BEGIN TO WORK BACK INTO THE REGION. DEWPOINTS WILL RISE FROM THEIR LOW POINT IN THE LOWER 50S TODAY...TO AROUND 60 ON THURSDAY...AND INTO THE MID 60S BY FRIDAY. THE SFC WIND WILL BE FAIRLY LIGHT...BUT IS EXPECTED TO BECOME GENERALLY SOUTHERLY...WHICH WILL HELP TO WARM THINGS UP A COUPLE DEGREES BACK TO AROUND NORMAL IN THE UPPER 80S TO AROUND 90. THE UPPER RIDGE OVER THE SOUTHERN PLAINS WILL RETROGRADE BACK TO THE WEST AND SET UP OVER THE DESERT SOUTHWEST. IN OUR AREA THERE WILL BE AN AREA OF WEAK SFC CONVERGENCE ACROSS OUR NORTHERN AND EASTERN ZONES FRIDAY AFTERNOON THAT COULD POP A FEW ISOLATED THUNDERSTORMS BASED ON THE 00Z NAM AND 00Z GFS. CONFIDENCE IS LOW AND CONVECTION WOULD LIKELY BE VERY HIT AND MISS WITH MOST FOLKS LIKELY MISSING OUT ON IT. SATURDAY THROUGH MONDAY...NORTHWESTERLY FLOW ALOFT WILL SEND US A FEW SHORTWAVES AND SUBSEQUENT THUNDERSTORM CHANCES. ONE SUCH SHORTWAVE IS EVIDENT IN THE 00Z GFS AND 00Z ECMWF SATURDAY AFTERNOON/EVENING. THEREFORE...WILL THROW SOME CHANCE POPS IN THE FORECAST WITH THE HIGHEST POPS BEING ACROSS NORTHERN AND EASTERN ZONES. OVERALL...AT LEAST THE WAY IT LOOK RIGHT NOW...PRECIPITATION CHANCES WILL STILL BE FAIRLY LOW AT LESS THAN 50/50. WE SHOULD BE IN BETWEEN SHORTWAVES ON SUNDAY SO CONFIDENCE IN DRY WEATHER IS FAIRLY GOOD FOR SUNDAY. THE NEXT SHORTWAVE ENTERS THE PICTURE ON MONDAY BUT FORECAST MODELS DIFFER ON THE SPEED OF THE ASSOCIATED FRONT. GIVEN THE EXPECTATION OF HAVING SOME UPPER LEVEL SUPPORT IN THE GENERAL AREA FROM THIS UPPER WAVE...WILL CALL FOR CHANCE POPS. TEMPERATURES WILL REMAIN NEAR NORMAL DURING THIS STRETCH...OR GENERALLY IN THE UPPER 80S TO LOWER 90S. TUESDAY...CONFIDENCE IS PRETTY LOW THIS FAR OUT GIVEN THE NORTHWESTERLY FLOW REGIME. THEREFORE...WILL STICK WITH THE SUPERBLEND OF ALL MODELS...WHICH GIVES US A SMALL CHANCE OF PRECIPITATION AND SLIGHTLY COOLER TEMPERATURES WITH HIGHS IN THE MID TO UPPER 80S. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1236 AM CDT WED JUL 29 2015 COMPARED TO THE PAST 24 HOURS...SHOULD BE A CONSIDERABLY MORE "STRAIGHTFORWARD" UPCOMING 24 HOURS IN THE AVIATION DEPARTMENT. FIRST OFF...NOT ANTICIPATING ANY PRECIPITATION/THUNDERSTORMS. CONFIDENCE IS ACTUALLY VERY HIGH IN VFR CEILING...ALTHOUGH MUCH OF THE LATTER HALF OF THE PERIOD COULD FEATURE SOME CONSIDERABLE MID-LEVEL CLOUD COVER. VISIBILITY-WISE...CONFIDENCE IS ALSO RATHER HIGH IN VFR...BUT THERE DOES APPEAR TO BE THE SLIMMEST POSSIBILITY FOR A BRIEF PERIOD OF MVFR EARLY THIS MORNING IN LIGHT HAZE...SO AT LEAST HINTED AT THIS WITH A "6SM BR" MENTION. AS FOR SURFACE WIND...THE VAST MAJORITY OF THE PERIOD SHOULD FEATURE SPEEDS AT/BELOW 6KT...AND WITH A HIGH PRESSURE AXIS CENTERED OVER THE REGION...DIRECTION WILL BE RATHER VARIABLE IN NATURE. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...WESELY AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
413 AM EDT WED JUL 29 2015 .SYNOPSIS...A WEAK SURFACE TROUGH WILL REMAIN OVER CENTRAL NC TODAY AS AN UPPER LEVEL RIDGE BRIEFLY BUILDS OVERHEAD. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY AND SINK SOUTH OF THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 350 AM WEDNESDAY... NORTHWESTERLY FLOW ALOFT WILL SHIFT TO A LITTLE MORE NORTHERLY TODAY AS THE CENTRAL US RIDGE BUILDS EAST IN RESPONSE TO A STRONG SHORTWAVE CROSSING THE UPPER MIDWEST. WATER VAPOR IMAGERY AND RAP H5 VORTICITY SUGGEST A COUPLE WEAK DISTURBANCES WILL DROP SOUTH ACROSS THE AREA...BUT NEITHER APPEARS TO BE VERY STRONG AND THERE SHOULDN`T BE MUCH IMPACT GIVEN THAT HEIGHTS BUILD ALOFT AND INSTABILITY WILL BE WEAK. AT THE SURFACE...A TROUGH EXTENDING SOUTH FROM THE MID ATLANTIC STATES APPEARS TO HAVE SUNK A LITTLE FURTHER SOUTH IN RESPONSE TO THE LAST EVENINGS CONVECTION NEAR THE NC-VA BORDER...NOW SITUATED FROM ROUGHLY DAVIDSON COUNTY NORTHEAST TO GRANVILLE COUNTY. THIS COULD SERVE AS AN ADDITIONAL FOCUS FROM SOME WIDELY SCATTERED CONVECTION...IN ADDITION TO CONVECTION OVER THE HIGHER TERRAIN...AND RECENT RUNS OF THE HRRR HINT AT DEVELOPMENT BY MIDDAY. IF NOTHING FORMS ON THIS BOUNDARY AND/OR IT WASHES OUT...THEN CONVECTION WILL BE FOCUS OVER THE NORTHWEST PIEDMONT AND SHOULDN`T HAVE MUCH OPPORTUNITY TO MOVE EAST GIVEN WEAK NORTHERLY STEERING FLOW. OVERALL...THE COVERAGE OF SHOWERS/STORMS IS EXPECTED TO BE LESS THAN THE PAST COUPLE OF DAYS. HIGHS SHOULD BE ABLE TO REACH THE FULL SUN POTENTIAL AS IR IMAGERY SHOWS LITTLE IN THE WAY OF UPSTREAM CLOUD COVER TO INHIBIT HEATING. HIGHS 88-93. CONVECTION SHOULD SEND A LITTLE SOONER THIS EVENING WITH LOSS OF HEATING AND NO SUPPORT FROM DISTURBANCES ALOFT. THERE IS A DISTURBANCE OVER SOUTHERN MICHIGAN THIS MORNING THAT IS FORECAST TO DIVE SOUTH LATE TONIGHT AND EARLY THURSDAY...WHICH COULD CONCEIVABLY CAUSE SOME REDEVELOPMENT OF SHOWERS...MAINLY WEST..BY EARLY THURSDAY MORNING...BUT GUIDANCE DOESN`T SHOW MUCH ACTIVITY...SO WILL LEAVE THE OVERNIGHT FORECAST DRY. LOWS WILL BE IN THE LOWER 70S. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 400 AM WEDNESDAY... A COLD FRONT...ATTENDANT TO AN OCCLUDED LOW WAY TO THE NORTH OVER CENTRAL CANADA...WILL APPROACH FROM THE NORTHWEST ON THURSDAY. THE PREFRONTAL LEE TROUGH WILL SHARPEN IN RESPONSE TO THE APPROACHING FRONT... BUT WITH INSTABILITY STILL EXPECTED TO BE RELATIVELY WEAK...MODELS ARE SURPRISINGLY DRY DURING THE DAY ON THURSDAY. THERE IS A DISTURBANCE FORECAST TO DIVE SOUTH INTO THE AREA EARLY THURSDAY...AS MENTIONED IN THE NEAR TERM DISCUSSION...AND EVOLUTION OF THIS FEATURE MAY BE WORTH WATCHING TO SEE IF/HOW IT COULD IMPACT CONVECTION INITIATION ON THURSDAY. THE FRONT WILL PUSH INTO THE AREA THURSDAY EVENING...BUT POOR DIURNAL TIMING AND FORCING LIMITED TO JUST FRONTAL CONVERGENCE SHOULD RESULT IN JUST SCATTERED CONVECTION AND NO WIDESPREAD SEVERE WEATHER. HIGHS THURSDAY HAVE THE POTENTIAL TO REACH THE LOW TO MID 90S ACROSS THE ENTIRE AREA AS THE 850MB THERMAL RIDGE SHIFTS OVER THE AREA AHEAD OF THE FRONT AND 850MB TEMPS REACH 19-20C. SOME HIGH CLOUDS ASSOCIATED WITH THE FRONTAL ZONE WILL SPREAD ACROSS THE AREA BUT CURRENTLY DO NOT LOOK WIDESPREAD OR THICK ENOUGH TO IMPACT HIGHS. LOWS THURSDAY NIGHT WILL BE MOSTLY IN THE LOW TO MID 70S...ESPECIALLY INT HE SOUTHEAST WHERE THE FRONT WILL ONLY SLOW REACH BY FRIDAY MORNING. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 410 AM WEDNESDAY... FORECAST RATIONALE REMAINS GENERALLY UNCHANGED FROM PREVIOUS DAYS. THE MODELS REMAIN IN GOOD AGREEMENT REGARDING THE PERSISTENCE OF AN EASTERN CONUS TROUGH FORECAST TO DEVELOP DURING THE NEAR AND SHORT TERM...COINCIDENT WITH THE RETROGRESSION OF A SUB-TROPICAL RIDGE FROM THE SOUTHERN PLAINS AND MID-MS VALLEY WEST TO THE FOUR CORNERS REGION. MEANWHILE IN THE LOW LEVELS...THE MODELS AGREE THAT A COLD FRONT RELATED TO A POTENT UPPER LOW OVER SOUTHERN MANITOBA THIS MORNING WILL BE INVOF THE I-95 CORRIDOR FRI MORNING...THEN DRIFT SOUTHEAST THROUGH THE COASTAL PLAIN THROUGH THE MIDDAY-AFTERNOON HOURS. THIS GRADUALLY DIFFUSING BOUNDARY WILL BE THE FOCUS FOR SHOWERS AND STORMS CENTERED OVER THE EASTERN CAROLINAS FRI-SUN...WHILE A DRIER AIR MASS BOTH AT THE SURFACE AND ALOFT SETTLES ACROSS THE WESTERN... AND MUCH OF THE CENTRAL PART...OF NC. AS THE PREVIOUS SHIFT NOTED...ANY NORTHWESTWARD SHIFT IN THE FRONTAL POSITION AND ASSOCIATED AXIS OF TROPICAL MOISTURE --CHARACTERIZED BY PRECIPITABLE WATER VALUES AOA TWO INCHES-- WOULD RESULT IN A WETTER WEEKEND FOR PARTICULARLY EAST-CENTRAL NC. THOUGH MODEL SPREAD INCREASES BY THE EARLY-MIDDLE OF NEXT WEEK...THE MODELS TO VARYING DEGREES HAVE HINTED THAT THE TROPICAL MOISTURE MAY GET DRAWN NORTH/INCORPORATED INTO THE LONGWAVE TROUGH BY LATE SUN-MON...AT WHICH TIME THE PROBABILITY OF SHOWERS AND STORMS ARE MORE LIKELY TO INCREASE THROUGHOUT CENTRAL NC. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 145 AM WEDNESDAY... CONVECTION FROM LAST EVENING DIMINISHED A FEW HOURS AGO...LEAVING JUST CONVECTIVE DEBRIS CLOUDS AT OR ABOVE 6K FT DRIFTING SOUTHEAST ACROSS THE AREA. THE CRUX OF THE CLOUD COVER APPEARS TO BE MOVING SOUTH OF THE AREA AND SOME DRIER AIR ALOFT IS MOVING IN FROM UPSTREAM...WHICH SHOULD ALLOW SOME AREAS OF SUB-VFR VSBY TO DEVELOP. BASED ON EARLIER RAINFALL...KINT AND KGSO SHOULD RUN THE BEST CHANCE OF IFR OR LIFR VSBYS...AND KGSO HAS ALREADY REPORTED A PERIOD OF 1/2SM VSBY WITH PARTIAL CLEARING. CONFIDENCE IS ONLY MEDIUM AT THE MOMENT...BUT THERE IS SOME SUPPORT FROM THE HRRR MODEL. EXPECT MAINLY MVFR VSBYS AT OTHER SITES...THOUGH THE OFTEN FOG PRONE KRWI MAY SEE LOWER VSBYS AS WELL. AN UPPER LEVEL RIDGE WILL BRIEFLY BUILD OVER THE REGION TODAY AND MAY LIMIT STORM COVERAGE MORE SO THAN IN PRIOR DAYS. AS SUCH...WILL NOT MENTION THUNDER IN THE CURRENT TAF...BUT CHANCES WILL BE GREATEST AT KGSO AND KINT ONCE AGAIN. OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY...WITH SOME PREFRONTAL CONVECTION POSSIBLE THURSDAY AFTERNOON. THE FRONT WILL THEN PUSH THROUGH THE AREA THURSDAY NIGHT AND SETTLE SOUTH OF THE AREA ON FRIDAY. IF THIS FRONT DOES PUSH ALL THE WAY THROUGH THE AREA...THEN VFR CONDITIONS WILL BE MUCH MORE LIKELY FOR THE UPCOMING WEEKEND. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...22 LONG TERM...26 AVIATION...22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
400 AM EDT WED JUL 29 2015 .SYNOPSIS...A WEAK SURFACE TROUGH WILL REMAIN OVER CENTRAL NC TODAY AS AN UPPER LEVEL RIDGE BRIEFLY BUILDS OVERHEAD. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY AND SINK SOUTH OF THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 350 AM WEDNESDAY... NORTHWESTERLY FLOW ALOFT WILL SHIFT TO A LITTLE MORE NORTHERLY TODAY AS THE CENTRAL US RIDGE BUILDS EAST IN RESPONSE TO A STRONG SHORTWAVE CROSSING THE UPPER MIDWEST. WATER VAPOR IMAGERY AND RAP H5 VORTICITY SUGGEST A COUPLE WEAK DISTURBANCES WILL DROP SOUTH ACROSS THE AREA...BUT NEITHER APPEARS TO BE VERY STRONG AND THERE SHOULDN`T BE MUCH IMPACT GIVEN THAT HEIGHTS BUILD ALOFT AND INSTABILITY WILL BE WEAK. AT THE SURFACE...A TROUGH EXTENDING SOUTH FROM THE MID ATLANTIC STATES APPEARS TO HAVE SUNK A LITTLE FURTHER SOUTH IN RESPONSE TO THE LAST EVENINGS CONVECTION NEAR THE NC-VA BORDER...NOW SITUATED FROM ROUGHLY DAVIDSON COUNTY NORTHEAST TO GRANVILLE COUNTY. THIS COULD SERVE AS AN ADDITIONAL FOCUS FROM SOME WIDELY SCATTERED CONVECTION...IN ADDITION TO CONVECTION OVER THE HIGHER TERRAIN...AND RECENT RUNS OF THE HRRR HINT AT DEVELOPMENT BY MIDDAY. IF NOTHING FORMS ON THIS BOUNDARY AND/OR IT WASHES OUT...THEN CONVECTION WILL BE FOCUS OVER THE NORTHWEST PIEDMONT AND SHOULDN`T HAVE MUCH OPPORTUNITY TO MOVE EAST GIVEN WEAK NORTHERLY STEERING FLOW. OVERALL...THE COVERAGE OF SHOWERS/STORMS IS EXPECTED TO BE LESS THAN THE PAST COUPLE OF DAYS. HIGHS SHOULD BE ABLE TO REACH THE FULL SUN POTENTIAL AS IR IMAGERY SHOWS LITTLE IN THE WAY OF UPSTREAM CLOUD COVER TO INHIBIT HEATING. HIGHS 88-93. CONVECTION SHOULD SEND A LITTLE SOONER THIS EVENING WITH LOSS OF HEATING AND NO SUPPORT FROM DISTURBANCES ALOFT. THERE IS A DISTURBANCE OVER SOUTHERN MICHIGAN THIS MORNING THAT IS FORECAST TO DIVE SOUTH LATE TONIGHT AND EARLY THURSDAY...WHICH COULD CONCEIVABLY CAUSE SOME REDEVELOPMENT OF SHOWERS...MAINLY WEST..BY EARLY THURSDAY MORNING...BUT GUIDANCE DOESN`T SHOW MUCH ACTIVITY...SO WILL LEAVE THE OVERNIGHT FORECAST DRY. LOWS WILL BE IN THE LOWER 70S. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 400 AM WEDNESDAY... A COLD FRONT...ATTENDANT TO AN OCCLUDED LOW WAY TO THE NORTH OVER CENTRAL CANADA...WILL APPROACH FROM THE NORTHWEST ON THURSDAY. THE PREFRONTAL LEE TROUGH WILL SHARPEN IN RESPONSE TO THE APPROACHING FRONT... BUT WITH INSTABILITY STILL EXPECTED TO BE RELATIVELY WEAK...MODELS ARE SURPRISINGLY DRY DURING THE DAY ON THURSDAY. THERE IS A DISTURBANCE FORECAST TO DIVE SOUTH INTO THE AREA EARLY THURSDAY...AS MENTIONED IN THE NEAR TERM DISCUSSION...AND EVOLUTION OF THIS FEATURE MAY BE WORTH WATCHING TO SEE IF/HOW IT COULD IMPACT CONVECTION INITIATION ON THURSDAY. THE FRONT WILL PUSH INTO THE AREA THURSDAY EVENING...BUT POOR DIURNAL TIMING AND FORCING LIMITED TO JUST FRONTAL CONVERGENCE SHOULD RESULT IN JUST SCATTERED CONVECTION AND NO WIDESPREAD SEVERE WEATHER. HIGHS THURSDAY HAVE THE POTENTIAL TO REACH THE LOW TO MID 90S ACROSS THE ENTIRE AREA AS THE 850MB THERMAL RIDGE SHIFTS OVER THE AREA AHEAD OF THE FRONT AND 850MB TEMPS REACH 19-20C. SOME HIGH CLOUDS ASSOCIATED WITH THE FRONTAL ZONE WILL SPREAD ACROSS THE AREA BUT CURRENTLY DO NOT LOOK WIDESPREAD OR THICK ENOUGH TO IMPACT HIGHS. LOWS THURSDAY NIGHT WILL BE MOSTLY IN THE LOW TO MID 70S...ESPECIALLY INT HE SOUTHEAST WHERE THE FRONT WILL ONLY SLOW REACH BY FRIDAY MORNING. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 PM TUESDAY... THE MAIN FEATURE FOR OUR AREA DURING THE LONG TERM PERIOD WILL BE THE DEEPENING LONG WAVE TROUGH OVER THE EAST. IT WILL BEGIN LATE THURSDAY AS THE TROUGH BEGINS DEEPENING OVER THE OHIO VALLEY AND MID ATLANTIC REGION...AND IN DOING SO WILL PUSH A COLD FRONT ACROSS OUR AREA THURSDAY NIGHT. WILL HAVE TO BEGIN RAMPING POPS UP ACROSS OUR WESTERN ZONES DURING THE AFTERNOON THURSDAY...BUT MOST OF DAYTIME THURSDAY SHOULD REMAIN DRY. THE BEST CHANCE FOR RAIN WILL BE THURSDAY NIGHT INTO FRIDAY MORNING...THEN RAIN CHANCES ENDING FROM W- E DURING THE AFTERNOON FRIDAY. TEMPS DURING THIS TIME NEAR NORMAL. FAIR WEATHER THEN APPEARS TO BE IN STORE FOR CENTRAL NC OVER THE WEEKEND WITH HIGH PRESSURE BUILDING TO OUR NORTH AND MUCH DRIER AIR OVER OUR REGION. THE PROGGED LOW LEVEL AIRMASS STILL APPEARS TO SUPPORT HIGHS AS WARM AS THE LOW 90S...SO LITTLE IF ANY RELIEF TEMPERATURE-WISE DESPITE HIGH PRESSURE BUILDING TO OUR NORTH. POPS EXPECTED TO REBOUND CLOSER TO DAILY CLIMO VALUES AS WE HEAD THROUGH EARLY NEXT WEEK AND PWAT SLOWLY RECOVERS. HOWEVER... COVERAGE SHOULD BE ISOLATED AT BEST GIVEN THE BETTER SYNOP FEATURES REMAINING BOTH TO OUR NORTH AND TO OUR SOUTH. IT`S WORTH NOTING THAT GIVEN THE LINGERING BOUNDARY AND LOW PRESSURE TO OUR SOUTH DURING THIS TIME...ANY SLIGHT NORTHWARD SHIFT IN THE PATTERN COULD MEAN HIGHER RAIN CHANCES FOR US DURING THE WEEKEND AND EARLY NEXT WEEK...ESP ACROSS OUR SOUTHERN ZONES. SO GIVEN OUR PROXIMITY TO THESE FEATURES...OUR CONFIDENCE IN THIS PART OF THE FORECAST ISN`T PARTICULARLY HIGH. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 145 AM WEDNESDAY... CONVECTION FROM LAST EVENING DIMINISHED A FEW HOURS AGO...LEAVING JUST CONVECTIVE DEBRIS CLOUDS AT OR ABOVE 6K FT DRIFTING SOUTHEAST ACROSS THE AREA. THE CRUX OF THE CLOUD COVER APPEARS TO BE MOVING SOUTH OF THE AREA AND SOME DRIER AIR ALOFT IS MOVING IN FROM UPSTREAM...WHICH SHOULD ALLOW SOME AREAS OF SUB-VFR VSBY TO DEVELOP. BASED ON EARLIER RAINFALL...KINT AND KGSO SHOULD RUN THE BEST CHANCE OF IFR OR LIFR VSBYS...AND KGSO HAS ALREADY REPORTED A PERIOD OF 1/2SM VSBY WITH PARTIAL CLEARING. CONFIDENCE IS ONLY MEDIUM AT THE MOMENT...BUT THERE IS SOME SUPPORT FROM THE HRRR MODEL. EXPECT MAINLY MVFR VSBYS AT OTHER SITES...THOUGH THE OFTEN FOG PRONE KRWI MAY SEE LOWER VSBYS AS WELL. AN UPPER LEVEL RIDGE WILL BRIEFLY BUILD OVER THE REGION TODAY AND MAY LIMIT STORM COVERAGE MORE SO THAN IN PRIOR DAYS. AS SUCH...WILL NOT MENTION THUNDER IN THE CURRENT TAF...BUT CHANCES WILL BE GREATEST AT KGSO AND KINT ONCE AGAIN. OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY...WITH SOME PREFRONTAL CONVECTION POSSIBLE THURSDAY AFTERNOON. THE FRONT WILL THEN PUSH THROUGH THE AREA THURSDAY NIGHT AND SETTLE SOUTH OF THE AREA ON FRIDAY. IF THIS FRONT DOES PUSH ALL THE WAY THROUGH THE AREA...THEN VFR CONDITIONS WILL BE MUCH MORE LIKELY FOR THE UPCOMING WEEKEND. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...22 LONG TERM...RAH AVIATION...22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 AM EDT WED JUL 29 2015 .SYNOPSIS...A WEAK SURFACE TROUGH WILL REMAIN OVER CENTRAL NC TODAY AS AN UPPER LEVEL RIDGE BRIEFLY BUILDS OVERHEAD. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY AND SINK SOUTH OF THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1050 PM TUESDAY... THE 00Z WEDNESDAY UPPER AIR ANALYSES CONTINUE TO SHOW THE UPPER LEVEL RIDGE CENTERED TO THE WEST-SOUTHWEST...WITH GENERALLY NW FLOW ALOFT OVER CENTRAL NC. ASIDE FROM A FEW LINGERING SHOWERS IN VA... THE CONVECTION FROM EARLY THIS EVENING HAS ENDED. A FEW OF THE HI- RES CAMS TRY TO GENERATE SOME ADDITIONAL SHOWER ACTIVITY IN THE NW OVERNIGHT. ALTHOUGH CONFIDENCE IS NOT TERRIBLY HIGH AT THIS TIME...WILL FORECAST A SLIGHT CHANCE FOR SHOWERS IN THE NW TONIGHT. OTHERWISE...EXPECT LOWS IN THE LOW TO MID 70S OVERNIGHT. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... AS OF 335 PM TUESDAY... UPPER RIDGE CENTERED OVER THE SOUTHERN PLAINS TEMPORARILY AMPLIFIES/EXTENDS EASTWARD INTO THE CAROLINAS WEDNESDAY IN RESPONSE TO A S/W TRAVERSING THE NORTHERN PLAINS. THIS BUILDING OF HEIGHTS ALOFT WILL INDUCE A MID LEVEL CAP ON THE ATMOSPHERE...INHIBITING CONVECTIVE DEVELOPMENT OVER MOST OF THE AREA. THE EXCEPTION WILL BE THE FAR WEST AND NORTH SECTIONS OF THE CWA WHERE THE PERSISTENT LEESIDE TROUGH AND A STALLED WEAK SFC BOUNDARY WILL PROVIDE A FOCUS FOR IS ATTRIBUTED TO PATCHY FOG AND/OR LOW CLOUDS. THIS OCCURRENCE APPEARS MORE LIKELY AT KRWI AND POSSIBLY KFAY.OLATED-SCATTERED CONVECTION INT EH AFTERNOON-EARLY EVENING. MAX TEMPS WEDNEDAY SHOULD BE COMPARABLE TO HIGH TEMPS RECORDED TODAY (NEAR 90-LOWER 90S). POTENTIAL TO SEE A SPOT OR TWO IN THE SOUTHERN PIEDMONT/SANDHILLS FLIRT WITH MID 90S. MIN TEMPS NEAR 70-LOWER 70S. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 PM TUESDAY... THE MAIN FEATURE FOR OUR AREA DURING THE LONG TERM PERIOD WILL BE THE DEEPENING LONG WAVE TROUGH OVER THE EAST. IT WILL BEGIN LATE THURSDAY AS THE TROUGH BEGINS DEEPENING OVER THE OHIO VALLEY AND MID ATLANTIC REGION...AND IN DOING SO WILL PUSH A COLD FRONT ACROSS OUR AREA THURSDAY NIGHT. WILL HAVE TO BEGIN RAMPING POPS UP ACROSS OUR WESTERN ZONES DURING THE AFTERNOON THURSDAY...BUT MOST OF DAYTIME THURSDAY SHOULD REMAIN DRY. THE BEST CHANCE FOR RAIN WILL BE THURSDAY NIGHT INTO FRIDAY MORNING...THEN RAIN CHANCES ENDING FROM W- E DURING THE AFTERNOON FRIDAY. TEMPS DURING THIS TIME NEAR NORMAL. FAIR WEATHER THEN APPEARS TO BE IN STORE FOR CENTRAL NC OVER THE WEEKEND WITH HIGH PRESSURE BUILDING TO OUR NORTH AND MUCH DRIER AIR OVER OUR REGION. THE PROGGED LOW LEVEL AIRMASS STILL APPEARS TO SUPPORT HIGHS AS WARM AS THE LOW 90S...SO LITTLE IF ANY RELIEF TEMPERATURE-WISE DESPITE HIGH PRESSURE BUILDING TO OUR NORTH. POPS EXPECTED TO REBOUND CLOSER TO DAILY CLIMO VALUES AS WE HEAD THROUGH EARLY NEXT WEEK AND PWAT SLOWLY RECOVERS. HOWEVER... COVERAGE SHOULD BE ISOLATED AT BEST GIVEN THE BETTER SYNOP FEATURES REMAINING BOTH TO OUR NORTH AND TO OUR SOUTH. IT`S WORTH NOTING THAT GIVEN THE LINGERING BOUNDARY AND LOW PRESSURE TO OUR SOUTH DURING THIS TIME...ANY SLIGHT NORTHWARD SHIFT IN THE PATTERN COULD MEAN HIGHER RAIN CHANCES FOR US DURING THE WEEKEND AND EARLY NEXT WEEK...ESP ACROSS OUR SOUTHERN ZONES. SO GIVEN OUR PROXIMITY TO THESE FEATURES...OUR CONFIDENCE IN THIS PART OF THE FORECAST ISN`T PARTICULARLY HIGH. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 145 AM WEDNESDAY... CONVECTION FROM LAST EVENING DIMINISHED A FEW HOURS AGO...LEAVING JUST CONVECTIVE DEBRIS CLOUDS AT OR ABOVE 6K FT DRIFTING SOUTHEAST ACROSS THE AREA. THE CRUX OF THE CLOUD COVER APPEARS TO BE MOVING SOUTH OF THE AREA AND SOME DRIER AIR ALOFT IS MOVING IN FROM UPSTREAM...WHICH SHOULD ALLOW SOME AREAS OF SUB-VFR VSBY TO DEVELOP. BASED ON EARLIER RAINFALL...KINT AND KGSO SHOULD RUN THE BEST CHANCE OF IFR OR LIFR VSBYS...AND KGSO HAS ALREADY REPORTED A PERIOD OF 1/2SM VSBY WITH PARTIAL CLEARING. CONFIDENCE IS ONLY MEDIUM AT THE MOMENT...BUT THERE IS SOME SUPPORT FROM THE HRRR MODEL. EXPECT MAINLY MVFR VSBYS AT OTHER SITES...THOUGH THE OFTEN FOG PRONE KRWI MAY SEE LOWER VSBYS AS WELL. AN UPPER LEVEL RIDGE WILL BRIEFLY BUILD OVER THE REGION TODAY AND MAY LIMIT STORM COVERAGE MORE SO THAN IN PRIOR DAYS. AS SUCH...WILL NOT MENTION THUNDER IN THE CURRENT TAF...BUT CHANCES WILL BE GREATEST AT KGSO AND KINT ONCE AGAIN. OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY...WITH SOME PREFRONTAL CONVECTION POSSIBLE THURSDAY AFTERNOON. THE FRONT WILL THEN PUSH THROUGH THE AREA THURSDAY NIGHT AND SETTLE SOUTH OF THE AREA ON FRIDAY. IF THIS FRONT DOES PUSH ALL THE WAY THROUGH THE AREA...THEN VFR CONDITIONS WILL BE MUCH MORE LIKELY FOR THE UPCOMING WEEKEND. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...22 NEAR TERM...10 SHORT TERM...WSS LONG TERM...RAH AVIATION...22
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
210 AM EDT WED JUL 29 2015 .SYNOPSIS... HIGH PRESSURE WILL PERSIST OVER THE REGION THROUGH WEDNESDAY...WITH TEMPERATURES REMAINING ABOVE NORMAL. A WEAK COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON THURSDAY AND SETTLE JUST SOUTH OF THE REGION ON FRIDAY. THE FRONT WILL LIKELY REMAIN STALLED JUST SOUTH OF THE AREA THROUGH THE WEEKEND...WITH COOLER TEMPERATURES EXPECTED. MOISTURE SHOULD INCREASINGLY RETURN NORTHWARD OVER THE FRONT THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 2 AM...I WILL RECONFIGURE THE FOG MENTION TO LATEST GUIDANCE AND OBSERVATIONS. OTHERWISE...THE CURRENT FORECAST REMAINS ON TRACK. AS OF 1215 AM...LATEST REGIONAL RADAR COMPOSITE INDICATES THAT SHOWERS HAVE DISSIPATED ACROSS THE CWA. LATEST GUIDANCE SHOWS LITTLE POTENTIAL FOR SHOWERS TO DEVELOP THROUGH THE REST OF THE NIGHT. I WILL UPDATE THE FORECAST TO REDUCE POPS BELOW SCHC AND DELAY MENTION OF FOG. 0200 UTC UPDATE...POPS HAVE BEEN REDUCED OVER MOST OF THE AREA PER RADAR TRENDS...WITH THE EXCEPTION OF THE NW NC PIEDMONT WHERE ACTIVITY IS MOST PRONOUNCED. ONLY MINOR CHANGES WERE MADE TO TEMPERATURES AND DEW POINTS OVERNIGHT. SKY COVER WAS UPDATED FROM INFRARED SATELLITE IMAGERY. 0000 UTC UPDATE...POPS HAVE BEEN ADJUSTED TO ACCOUNT FOR MORE CONVECTION MOVING TOWARD THE NW NC PIEDMONT...AND ACTIVITY OVER THE SC PIEDMONT. QPF WAS ADJUSTED ACCORDINGLY. 2315 UTC UPDATE...POPS HAVE BEEN INCREASED IN THE NW NC PIEDMONT...THE SOUTHERN INTERSTATE 77 CORRIDOR...AND THE SW NC MOUNTAINS PER RADAR TRENDS. QPF HAS BEEN ADJUSTED ACCORDINGLY. SKY COVER WAS UPDATED FROM VISIBLE SATELLITE IMAGERY...WITH INCREASES IN THE PIEDMONT AND MOUNTAINS...AND DECREASES IN BETWEEN. 2100 UTC UPDATE...POPS HAVE BEEN RAISED ALONG THE SOUTHERN INTERSTATE 77 CORRIDOR PER RADAR TRENDS...AND LOWERED IN THE SC INTERSTATES 85 CORRIDOR. 1940 UTC UPDATE...POPS AND QPF HAVE BEEN ADJUSTED TO FAVOR THE INTERSTATE 85 CORRIDOR PER RADAR TRENDS. SKY COVER WAS UPDATED FROM VISIBLE SATELLITE IMAGERY. AS OF 230 PM...CONVECTION WILL CONTINUE TO DEVELOP AND DRIFT TOWARD THE S-SE THIS AFTN...AS SUBTLE SHORTWAVE ENERGY ROUNDS THE EASTERN PERIPHERY OF A LARGE UPPER LEVEL HIGH. THE LATEST HRRR AND THE 12Z HIGH-RES WINDOWS ARE IN REALLY GOOD AGREEMENT ON THE TRENDS...SO I THINK THE POP GRIDS ARE ON TRACK...SINCE THEY WERE BLENDED WITH THOSE CAM POPS EARLIER. AS FOR SEVERE THREAT...WHILE THE STORMS HAVE BEEN GETTING FAIRLY TALL...THE FREEZING LEVEL ABOVE 15 KFT...AND LOW-MOD DCAPE OF 600-800 J/KG IS KEEPING THE MICROBURST THREAT IN CHECK. THERE IS ALSO A HEAVY RAIN THREAT...AS PWATS ARE 1.8-2.0" ACRS THE PIEDMONT...WITH SLOW STORM MOTIONS. TONIGHT...WEAK LOW PRES OVER SOUTHERN GA...AND HIGH PRES TO THE NORTH OF THE AREA WILL KEEP A LIGHT S/SE FLOW ACRS THE CWFA. THIS MAY BE ENUF TO ALLOW FOR LINGERING SHRA AND A FEW EMBEDDED TSTMS WELL PAST SUNSET. I HAVE POPS ON A SLOW DIMINISHING TREND FOR THE TONIGHT PERIOD...TO SLGT CHC BY DAYBREAK WED. LOWS IN THE MID-UPR 60S IN THE MTNS AND LWR-MID 70S PIEDMONT. ON WEDNESDAY...THE SYNOPTIC PATTERN WILL NOT CHANGE MUCH FROM TODAY...WITH 500 MB HIGH PRES CONTINUING TO NOSE N AND E INTO THE AREA FROM THE SOUTHERN PLAINS. HOWEVER...THE OP MODELS ALL RESOLVE ANOTHER VORT MAX DRIFTING SOUTH AROUND THE RIDGE ACRS THE OHIO VALLEY. THIS MAY HELP TRIGGER CONVECTION. THE LLVLS WILL BE SIMILAR...WITH ELEVATED DEWPTS IN THE 70S ACRS THE PIEDMONT. CAPE SHUD BE BACK ABOVE 1500 J/KG OR SO WITH VERY WEAK SHEAR. THE CAMS THAT GO OUT THRU TOMORROW SHOW SIMILAR CONVECTIVE TRENDS AS TODAY. SO WILL GO WITH HIGH-END CHC TO LIKELY POPS. SEVERE THREAT WILL REMAIN LOW WITH MOIST MID LVLS. A SMALL EXCESSIVE RAIN THREAT WILL CONTINUE. HIGHS AROUND PERSISTENCE IN THE 80S MTNS AND LWR-MID 90S PIEDMONT. && .SHORT TERM /TONIGHT THROUGH FRIDAY/... AS OF 140 PM TUESDAY...RETROGRESSION OF THE SUBTROPICAL HIGH INTO THE SOUTHERN ROCKIES/HIGH PLAINS WILL OCCUR THROUGHOUT THE SHORT TERM PERIOD...AS A SERIES OF SHORT WAVES CARVE OUT A LONG WAVE TROUGH ACROSS MUCH OF EASTERN NORTH AMERICA BY THE END OF THE PERIOD. THIS WILL INTRODUCE A (RATHER WEAK) FRONTAL BOUNDARY INTO OUR AREA BY THURSDAY. MEANWHILE...SLIGHT COOLING OF THE MID-LEVEL TEMPS AND CONTINUED HIGH DEWPOINT TEMPERATURES...ALONG WITH THE APPEARANCE OF THE BOUNDARY SHOULD SUPPORT CONTINUED GOOD CHANCES OF CONVECTION THURSDAY AFTERNOON...WITH PERHAPS A BETTER CHANCE FOR A FEW PULSE-SEVERE STORMS WITHIN A MORE UNSTABLE ENVIRONMENT. A DEVELOPING CONSENSUS IN SHORT TERM MODEL GUIDANCE INDICATES THE UPPER TROUGH AXIS WILL BE EAST OF THE FORECAST AREA BY FRI MORNING...TAKING THE FRONTAL BOUNDARY ALONG WITH IT. ALTHOUGH THICKNESS VALUES WILL NOT SUPPORT AN APPRECIABLE COOL DOWN (REALLY ONLY TAKING MAXES BACK TO NEAR-NORMAL LEVELS)...THERE WILL BE A NOTICEABLE CHANGE IN RELATIVE HUMIDITY ACROSS MUCH OF THE AREA FRI AFTERNOON...AS DEWPOINTS COULD MIX OUT INTO THE 50S. THE RESULT WILL BE SMALL (AT BEST) CHANCES FOR CONVECTION FRI AFTERNOON. ALTHOUGH SMALL POPS WILL BE ADVERTISED...MAINLY HIGHLIGHTING SOUTHERN AREAS NEARER THE BOUNDARY...EVEN THESE MAY PROVE TO BE ON THE HIGH SIDE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 210 PM TUESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SATURDAY WITH A BROAD UPPER TROF CENTERED OVER ONTARIO AND QUEBEC AND VERY BROAD UPPER RIDGING IN PLACE OVER THE WESTERN CONUS. THIS GENERAL PATTERN IS EXPECTED TO REMAIN IN PLACE THROUGH THE PERIOD WITH SOME DEAMPLIFICATION OF THE UPPER TROF POSSIBLE TOWARDS THE END OF THE PERIOD. AT THE SFC...RIDGING WILL SPREAD BACK OVER THE CWFA FROM THE NW BY THE START OF THE PERIOD AND LINGER INTO EARLY NEXT WEEK...GRADUALLY GETTING WEAKER. THE ECMWF STILL TRIES TO SPIN UP SOME SORT OF SFC LOW TO OUR SOUTH BY THE END OF THE PERIOD...HOWEVER THE GFS APPEARS LESS BULLISH ON LOW DEVELOPMENT NOW THAN IT HAS OVER THE PAST COUPLE OF DAYS. ALSO OF NOTE...THE LONG RANGE MODEL GUIDANCE IS NOW KEEPING THE PLUME OF DEEPER LYR MOISTURE FARTHER SOUTH AND EAST COMPARED TO PREVIOUS GUIDANCE. THIS WILL ALLOW FOR LOWER OVERALL POPS FOR MOST OF THE PERIOD. AS FOR THE SENSIBLE FCST...WE CAN EXPECT MOSTLY DIURNAL CHANCES FOR SCT CONVECTION EACH DAY/EVENING WITH THE BEST CHANCES OVER THE SE ZONES. TEMPS WILL START OUT RIGHT AROUND NORMAL AND REMAIN NEAR NORMAL THROUGH THE PERIOD. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...WET GROUND AND HUMID BL CONDITIONS ARE WIDESPREAD ACROSS THE NC PIEDMONT THIS MORNING. BASED ON LATEST MOS GUIDANCE AND FORECAST SOUNDING...IT APPEARS CONDITIONS WILL BECOME SUPPORTIVE FOR MVFR FOG DURING THE PRE DAWN HOURS. THE TAF WILL INCLUDE A TEMPO FOR 8Z TO 12Z FOR 5SM BR. SIMILAR TO TUESDAY...EARLY MORNING HEATING MAY SUPPORT MVFR CEILINGS THROUGH MID MORNING. A SWEEPING MID LEVEL SHORTWAVE WILL APPROACH THE REGION THIS AFTERNOON...LIKELY TRIGGERING CLUSTERS OF TSRA. USING THE EXAMPLE FROM TUESDAY...I WILL INCLUDE A PROB30 FOR TSRA FROM 19Z THROUGH 23Z. WINDS SHOULD FAVOR A SOUTH DIRECTION...LIKELY REMAINING LESS THAN 5 KTS. ELSEWHERE...OVERALL CONDITIONS SHOULD FOLLOW THE TIMING OF CLT. KAVL AND KHKY SHOULD SEE THE GREATEST POTENTIAL FOR FOG AND LOW CLOUDS EARLY THIS MORNING. OTHERWISE...THE ENVIRONMENT SHOULD YIELD MORNING MVFR STRATUS...MIXING TO VFR CU BY MID DAY. A SWEEPING MID LEVEL SHORTWAVE WILL APPROACH THE REGION THIS AFTERNOON...LIKELY TRIGGERING CLUSTERS OF TSRA. USING THE EXAMPLE FROM TUESDAY...I WILL INCLUDE A PROB30 FOR TSRA FROM 19Z THROUGH 23Z. OUTLOOK...AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE ATLANTIC STATES LATE IN THE WEEK...WITH THE LIKELY PASSAGE OF A COLD FRONT ON FRIDAY. THE POTENTIAL FOR CONVECTION WILL INCREASE THROUGH FRIDAY...THEN DECREASE BEHIND THE FRONT ON SATURDAY. CONFIDENCE TABLE... 06-12Z 12-18Z 18-24Z 00-06Z KCLT HIGH 93% MED 67% HIGH 100% HIGH 100% KGSP LOW 56% MED 65% HIGH 100% HIGH 100% KAVL MED 75% MED 70% HIGH 100% HIGH 100% KHKY MED 74% MED 76% HIGH 100% HIGH 100% KGMU MED 74% MED 63% HIGH 100% HIGH 100% KAND HIGH 81% MED 63% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JPT NEAR TERM...NED SHORT TERM...JDL LONG TERM...JPT AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1219 AM EDT WED JUL 29 2015 .SYNOPSIS... HIGH PRESSURE WILL PERSIST OVER THE REGION THROUGH WEDNESDAY...WITH TEMPERATURES REMAINING ABOVE NORMAL. A WEAK COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON THURSDAY AND SETTLE JUST SOUTH OF THE REGION ON FRIDAY. THE FRONT WILL LIKELY REMAIN STALLED JUST SOUTH OF THE AREA THROUGH THE WEEKEND...WITH COOLER TEMPERATURES EXPECTED. MOISTURE SHOULD INCREASINGLY RETURN NORTHWARD OVER THE FRONT THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 1215 AM...LATEST REGIONAL RADAR COMPOSITE INDICATES THAT SHOWERS HAVE DISSIPATED ACROSS THE CWA. LATEST GUIDANCE SHOWS LITTLE POTENTIAL FOR SHOWERS TO DEVELOP THROUGH THE REST OF THE NIGHT. I WILL UPDATE THE FORECAST TO REDUCE POPS BELOW SCHC AND DELAY MENTION OF FOG. 0200 UTC UPDATE...POPS HAVE BEEN REDUCED OVER MOST OF THE AREA PER RADAR TRENDS...WITH THE EXCEPTION OF THE NW NC PIEDMONT WHERE ACTIVITY IS MOST PRONOUNCED. ONLY MINOR CHANGES WERE MADE TO TEMPERATURES AND DEW POINTS OVERNIGHT. SKY COVER WAS UPDATED FROM INFRARED SATELLITE IMAGERY. 0000 UTC UPDATE...POPS HAVE BEEN ADJUSTED TO ACCOUNT FOR MORE CONVECTION MOVING TOWARD THE NW NC PIEDMONT...AND ACTIVITY OVER THE SC PIEDMONT. QPF WAS ADJUSTED ACCORDINGLY. 2315 UTC UPDATE...POPS HAVE BEEN INCREASED IN THE NW NC PIEDMONT...THE SOUTHERN INTERSTATE 77 CORRIDOR...AND THE SW NC MOUNTAINS PER RADAR TRENDS. QPF HAS BEEN ADJUSTED ACCORDINGLY. SKY COVER WAS UPDATED FROM VISIBLE SATELLITE IMAGERY...WITH INCREASES IN THE PIEDMONT AND MOUNTAINS...AND DECREASES IN BETWEEN. 2100 UTC UPDATE...POPS HAVE BEEN RAISED ALONG THE SOUTHERN INTERSTATE 77 CORRIDOR PER RADAR TRENDS...AND LOWERED IN THE SC INTERSTATES 85 CORRIDOR. 1940 UTC UPDATE...POPS AND QPF HAVE BEEN ADJUSTED TO FAVOR THE INTERSTATE 85 CORRIDOR PER RADAR TRENDS. SKY COVER WAS UPDATED FROM VISIBLE SATELLITE IMAGERY. AS OF 230 PM...CONVECTION WILL CONTINUE TO DEVELOP AND DRIFT TOWARD THE S-SE THIS AFTN...AS SUBTLE SHORTWAVE ENERGY ROUNDS THE EASTERN PERIPHERY OF A LARGE UPPER LEVEL HIGH. THE LATEST HRRR AND THE 12Z HIGH-RES WINDOWS ARE IN REALLY GOOD AGREEMENT ON THE TRENDS...SO I THINK THE POP GRIDS ARE ON TRACK...SINCE THEY WERE BLENDED WITH THOSE CAM POPS EARLIER. AS FOR SEVERE THREAT...WHILE THE STORMS HAVE BEEN GETTING FAIRLY TALL...THE FREEZING LEVEL ABOVE 15 KFT...AND LOW-MOD DCAPE OF 600-800 J/KG IS KEEPING THE MICROBURST THREAT IN CHECK. THERE IS ALSO A HEAVY RAIN THREAT...AS PWATS ARE 1.8-2.0" ACRS THE PIEDMONT...WITH SLOW STORM MOTIONS. TONIGHT...WEAK LOW PRES OVER SOUTHERN GA...AND HIGH PRES TO THE NORTH OF THE AREA WILL KEEP A LIGHT S/SE FLOW ACRS THE CWFA. THIS MAY BE ENUF TO ALLOW FOR LINGERING SHRA AND A FEW EMBEDDED TSTMS WELL PAST SUNSET. I HAVE POPS ON A SLOW DIMINISHING TREND FOR THE TONIGHT PERIOD...TO SLGT CHC BY DAYBREAK WED. LOWS IN THE MID-UPR 60S IN THE MTNS AND LWR-MID 70S PIEDMONT. ON WEDNESDAY...THE SYNOPTIC PATTERN WILL NOT CHANGE MUCH FROM TODAY...WITH 500 MB HIGH PRES CONTINUING TO NOSE N AND E INTO THE AREA FROM THE SOUTHERN PLAINS. HOWEVER...THE OP MODELS ALL RESOLVE ANOTHER VORT MAX DRIFTING SOUTH AROUND THE RIDGE ACRS THE OHIO VALLEY. THIS MAY HELP TRIGGER CONVECTION. THE LLVLS WILL BE SIMILAR...WITH ELEVATED DEWPTS IN THE 70S ACRS THE PIEDMONT. CAPE SHUD BE BACK ABOVE 1500 J/KG OR SO WITH VERY WEAK SHEAR. THE CAMS THAT GO OUT THRU TOMORROW SHOW SIMILAR CONVECTIVE TRENDS AS TODAY. SO WILL GO WITH HIGH-END CHC TO LIKELY POPS. SEVERE THREAT WILL REMAIN LOW WITH MOIST MID LVLS. A SMALL EXCESSIVE RAIN THREAT WILL CONTINUE. HIGHS AROUND PERSISTENCE IN THE 80S MTNS AND LWR-MID 90S PIEDMONT. && .SHORT TERM /TONIGHT THROUGH FRIDAY/... AS OF 140 PM TUESDAY...RETROGRESSION OF THE SUBTROPICAL HIGH INTO THE SOUTHERN ROCKIES/HIGH PLAINS WILL OCCUR THROUGHOUT THE SHORT TERM PERIOD...AS A SERIES OF SHORT WAVES CARVE OUT A LONG WAVE TROUGH ACROSS MUCH OF EASTERN NORTH AMERICA BY THE END OF THE PERIOD. THIS WILL INTRODUCE A (RATHER WEAK) FRONTAL BOUNDARY INTO OUR AREA BY THURSDAY. MEANWHILE...SLIGHT COOLING OF THE MID-LEVEL TEMPS AND CONTINUED HIGH DEWPOINT TEMPERATURES...ALONG WITH THE APPEARANCE OF THE BOUNDARY SHOULD SUPPORT CONTINUED GOOD CHANCES OF CONVECTION THURSDAY AFTERNOON...WITH PERHAPS A BETTER CHANCE FOR A FEW PULSE-SEVERE STORMS WITHIN A MORE UNSTABLE ENVIRONMENT. A DEVELOPING CONSENSUS IN SHORT TERM MODEL GUIDANCE INDICATES THE UPPER TROUGH AXIS WILL BE EAST OF THE FORECAST AREA BY FRI MORNING...TAKING THE FRONTAL BOUNDARY ALONG WITH IT. ALTHOUGH THICKNESS VALUES WILL NOT SUPPORT AN APPRECIABLE COOL DOWN (REALLY ONLY TAKING MAXES BACK TO NEAR-NORMAL LEVELS)...THERE WILL BE A NOTICEABLE CHANGE IN RELATIVE HUMIDITY ACROSS MUCH OF THE AREA FRI AFTERNOON...AS DEWPOINTS COULD MIX OUT INTO THE 50S. THE RESULT WILL BE SMALL (AT BEST) CHANCES FOR CONVECTION FRI AFTERNOON. ALTHOUGH SMALL POPS WILL BE ADVERTISED...MAINLY HIGHLIGHTING SOUTHERN AREAS NEARER THE BOUNDARY...EVEN THESE MAY PROVE TO BE ON THE HIGH SIDE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 210 PM TUESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON SATURDAY WITH A BROAD UPPER TROF CENTERED OVER ONTARIO AND QUEBEC AND VERY BROAD UPPER RIDGING IN PLACE OVER THE WESTERN CONUS. THIS GENERAL PATTERN IS EXPECTED TO REMAIN IN PLACE THROUGH THE PERIOD WITH SOME DEAMPLIFICATION OF THE UPPER TROF POSSIBLE TOWARDS THE END OF THE PERIOD. AT THE SFC...RIDGING WILL SPREAD BACK OVER THE CWFA FROM THE NW BY THE START OF THE PERIOD AND LINGER INTO EARLY NEXT WEEK...GRADUALLY GETTING WEAKER. THE ECMWF STILL TRIES TO SPIN UP SOME SORT OF SFC LOW TO OUR SOUTH BY THE END OF THE PERIOD...HOWEVER THE GFS APPEARS LESS BULLISH ON LOW DEVELOPMENT NOW THAN IT HAS OVER THE PAST COUPLE OF DAYS. ALSO OF NOTE...THE LONG RANGE MODEL GUIDANCE IS NOW KEEPING THE PLUME OF DEEPER LYR MOISTURE FARTHER SOUTH AND EAST COMPARED TO PREVIOUS GUIDANCE. THIS WILL ALLOW FOR LOWER OVERALL POPS FOR MOST OF THE PERIOD. AS FOR THE SENSIBLE FCST...WE CAN EXPECT MOSTLY DIURNAL CHANCES FOR SCT CONVECTION EACH DAY/EVENING WITH THE BEST CHANCES OVER THE SE ZONES. TEMPS WILL START OUT RIGHT AROUND NORMAL AND REMAIN NEAR NORMAL THROUGH THE PERIOD. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... AT KCLT...CONVECTION AND ASSOCIATED RESTRICTIONS WILL REMAIN POSSIBLE THIS EVENING. WITH RAIN HAVING ALREADY OCCURRED...AND MORE POSSIBLE...DAYBREAK MVFR FOG SEEMS LIKELY. MODEL TIME HEIGHTS SUPPORT A CIG AT AROUND 6000 FT FOR MUCH OF THE FORECAST...BUT SHOW SUBSTANTIAL MOISTURE MUCH LOWER...AND DAYBREAK FOG MAY BE ACCOMPANIED BY AN MVFR CIG...AND PERHAPS EVEN LOWER. ANOTHER ROUND OF CONVECTION IS EXPECTED WEDNESDAY AFTERNOON AS THE PATTERN CHANGES LITTLE. LIGHT WINDS WILL GENERALLY FAVOR THE S. ELSEWHERE...CONVECTION AND ASSOCIATED RESTRICTIONS CANNOT BE RULED OUT THIS EVENING...ALTHOUGH THE BEST COVERAGE OS EAST OF THE FOOTHILLS. DAYBREAK FOG IS LIKELY...AS MANY SITES HAD RAIN OR MAY RECEIVE SOME THIS EVENING...AND GUIDANCE IS LEANING IN THAT DIRECTION. THE WORST RESTRICTIONS WOULD BE AT KAVL AND KHKY. MODEL TIME HEIGHTS FAVOR LOW VFR CIGS AT AROUND 4500 TO 6000 FEET...BUT ENOUGH LOW LEVEL MOISTURE IS PRESENT TO ALLOW FOR DAYBREAK MVFR CIGS WHERE FOG OCCURS...AND POSSIBLE EVEN LOWER CIGS. YET ANOTHER AROUND OF CONVECTION IS EXPECTED WEDNESDAY AFTERNOON IN A PERSISTENT UPPER LEVEL PATTERN. LIGHT WINDS WILL FAVOR THE S. OUTLOOK...AN UPPER LEVEL TROUGH WILL AMPLIFY ACROSS THE ATLANTIC STATES LATE IN THE WEEK...WITH THE LIKELY PASSAGE OF A COLD FRONT ON FRIDAY. THE POTENTIAL FOR CONVECTION WILL INCREASE THROUGH FRIDAY...THEN DECREASE BEHIND THE FRONT ON SATURDAY. CONFIDENCE TABLE... 04-10Z 10-16Z 16-22Z 22-00Z KCLT HIGH 100% HIGH 97% HIGH 87% HIGH 100% KGSP HIGH 100% HIGH 100% MED 78% HIGH 100% KAVL HIGH 100% MED 63% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 83% HIGH 81% HIGH 100% KGMU HIGH 100% HIGH 100% MED 78% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...JPT NEAR TERM...NED SHORT TERM...JDL LONG TERM...JPT AVIATION...JAT
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
341 AM CDT WED JUL 29 2015 .DISCUSSION... ONE MORE DAY OF DANGEROUS HEAT AND HUMIDITY IS EXPECTED ON WEDNESDAY WITH RELIEF COMING IN THE FORM OF A COLD FRONT MOVING THROUGH THE MID-SOUTH LATE WEDNESDAY NIGHT/THURSDAY MORNING... CURRENTLY...A VERY WARM NIGHT WAS ONGOING ACROSS THE MID-SOUTH WITH TEMPERATURES NEAR 80 DEGREES AND DEWPOINTS IN THE MID TO UPPER 70S. ALOFT...AN UPPER LEVEL RIDGE WAS ANCHORED ACROSS MUCH OF THE SOUTHERN US. AT THE SURFACE...HIGH PRESSURE WAS IN PLACE ACROSS MUCH OF THE SOUTHEASTERN US WITH A COLD FRONT ORIENTED SW TO NE FROM THE TX PANHANDLE THROUGH NORTHERN MO/SRN WI. EARLIER IN THE EVENING...A SUBSTANTIAL COMPLEX OF THUNDERSTORMS DEVELOPED ACROSS PORTIONS OF MIDDLE TENNESSEE WHICH EXPELLED AN OUTFLOW BOUNDARY SOUTHWEST INTO PORTIONS OF THE TENNESSEE RIVER VALLEY. WHILE SURFACE WINDS ARE VARIABLE...THAT BOUNDARY IS LIKELY STILL PRESENT THROUGH THE REGION BUT BECOMING MORE DIFFUSE WITH TIME. FOR WEDNESDAY...EXCESSIVE HEAT IS STILL FORECAST...HOWEVER THERE ARE A FEW COMPLICATING FACTORS. HI-RES MEMBERS INCLUDING THE NSSL WRF AND THE HRRR DEVELOP THUNDERSTORMS EARLY IN THE DAY AS A WEAK DISTURBANCE DIVES SOUTHEAST AROUND THE PERIPHERY OF THE SURFACE RIDGE. THE AFOREMENTIONED OUTFLOW BOUNDARY MAY SERVE AS A FOCUS FOR THIS DEVELOPMENT BUT THIS SOLUTION IS EXTREMELY UNCERTAIN AT THIS POINT. IF IT WERE TO UNFOLD AS SUCH...PORTIONS OF WEST TENNESSEE ALONG THE TN RIVER MAY NOT REACH HEAT ADVISORY CRITERIA OWING TO CLOUD COVER/PRECIP. AT THIS POINT...DID NOT ADJUST THE ADVISORY GIVEN THE AFOREMENTIONED UNCERTAINTY. BELIEVE THE HI-RES SOLUTIONS TO BE MUCH TOO AGGRESSIVE WITH PRECIP DEVELOPMENT...BUT IT IS WORTH MENTIONING. FURTHER WEST TOWARD THE MS RIVER...EXCESSIVE HEAT WARNINGS REMAIN IN EFFECT ACROSS E AND NE AR/NW MS/W TN WITH HIGH CONFIDENCE IN DANGEROUS HEAT INDICES DEVELOPING FROM MIDDAY THROUGH EARLY EVENING. MANY LOCATIONS WILL EXPERIENCE SEVERAL HOURS OF HEAT INDICES BETWEEN 111 AND 114 DEGREES GIVEN THE EXTREMELY MOIST BOUNDARY LAYER IN PLACE WITH DEWPOINTS IN THE MID AND UPPER 70S AND TEMPERATURES IN THE UPPER 90S. PRECIPITATION IS NOT EXPECTED TO HINDER SOLAR HEATING AND SHOULD HOLD OFF UNTIL THE EVENING HOURS. WEDNESDAY NIGHT...THE FRONTAL BOUNDARY APPROACHES FROM THE NORTH BUT CONSIDERABLE UNCERTAINTY EXISTS WITH RESPECT TO COVERAGE OF SHOWERS AND THUNDERSTORMS. THERE WILL LIKELY BE ISOLATED DEVELOPMENT AFTER 00Z THURSDAY ALONG THE FRONT BUT PLACING THIS DEVELOPMENT IS DIFFICULT AT THIS TIME. FOR NOW...SLIGHT CHANCE TO CHANCE POPS WERE MAINTAINED TO ACCOUNT FOR THIS. BY THURSDAY...THE FRONTAL BOUNDARY WILL CONTINUE TO PUSH SOUTH WITH DRIER AIR ADVECTING INTO THE REGION. NORTHERN MISSISSIPPI MAY STILL NEAR HEAT ADVISORY CRITERIA EARLIER IN THE DAY BUT EVEN THIS SHOULD BE SHORT-LIVED AS CLOUD COVER AND SHOWERS/TSTORMS SHOULD PROVIDE RELIEF DURING THE MID TO LATE AFTERNOON HOURS. BY THURSDAY NIGHT...THE FRONT WILL HAVE CLEARED THE REGION LEAVING A MUCH MORE PLEASANT AIRMASS IN PLACE WITH DEWPOINTS IN THE LOW TO MID 60S AND TEMPERATURES IN THE UPPER 60S TO NEAR 70 THURSDAY NIGHT. THROUGH THE WEEKEND...A SLOW WARMUP IS EXPECTED BUT SEVERAL DAYS OF BEARABLE TEMPERATURES ARE FORECAST WITH LOWER HUMIDITY. THIS PERIOD SHOULD ALSO BE DRY FOR THE ENTIRE REGION. IN THE LONG-TERM...UPPER LEVEL RIDGING STRENGTHENS ACROSS THE DESERT SOUTHWEST WITH A PERSISTENT AREA OF UPPER LEVEL LOW PRESSURE ACROSS THE EAST-CENTRAL CANADIAN PROVINCES. THE MID-SOUTH WILL FALL SOMEWHERE BETWEEN THESE TWO FEATURES WITH WARMING TEMPERATURES ONCE AGAIN. A SLOW INCREASE IN HEIGHTS SUGGESTS THAT ANOTHER WARM TO HOT PERIOD MAY DEVELOP BUT IT IS TOO SOON TO TELL HOW HOT...BUT IT IS WORTH WATCHING. TVT && .AVIATION... 06Z TAF CYCLE PATCHY FOG MAY DEVELOP LATE TONIGHT PRODUCING TEMPORARY MVFR/IFR CONDITIONS AT MKL AND MVFR CONDITIONS AT TUP. OTHERWISE...VFR CONDITIONS EXPECTED TO PREVAIL AT SITES FOR MOST OF THE PERIOD. VCTS POSSIBLE AT SITES AFTER 29/12Z AND AT LEAST THROUGH 30/02Z AS AN UPPER LEVEL RIDGE BEGINS TO WEAKEN SLIGHTLY AND A WEAK COLD FRONT ENTERS THE LOWER MISSISSIPPI VALLEY. CJC && .MEG WATCHES/WARNINGS/ADVISORIES... AR...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR CLAY- CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR- MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR DUNKLIN- PEMISCOT. MS...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR COAHOMA- DESOTO-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA. HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-ITAWAMBA-LAFAYETTE-LEE MS-MONROE-PONTOTOC- PRENTISS-TIPPAH-TISHOMINGO-UNION-YALOBUSHA. TN...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR DYER- FAYETTE-LAKE-LAUDERDALE-OBION-SHELBY-TIPTON. HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BENTON TN-CARROLL- CHESTER-CROCKETT-DECATUR-GIBSON-HARDEMAN-HARDIN-HAYWOOD- HENDERSON-HENRY-MADISON-MCNAIRY-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1144 PM CDT TUE JUL 28 2015 .AVIATION 06Z DISCUSSION... CURRENT DEWPOINT SPREADS ARE RATHER LOW AND RANGE BETWEEN 1F AND 3F ACROSS MUCH OF THE AREA. BROKEN DECK...MOSTLY MID LEVEL WILL PERSIST THROUGH MUCH OF THE NIGHT. HOWEVER...FOG MAY RED VSBYS DOWN TO 3SM AT TIMES TOWARD 12Z. CAPE/CAP RATIO TO BECOME QUITE FAVORABLE ONCE AGAIN ON WED AFT. CATALYTIC IMPULSES MAY BE HARDER TO COME BY...HOWEVER...AS THE UPPER HIGH IS IN CLOSER PROXIMITY. STILL THOUGH...ISOL TO SCT ACTIVITY WILL LIKELY DEVELOP AFT 18Z. WILL INCLUDE PROB 30S FOR CKV AND BNA. SOME STORMS MAY BE STRONG WITH GUSTY WINDS POSSIBLE. && .PREV DISCUSSION... /ISSUED 906 PM CDT TUE JUL 28 2015/ UPDATE... BEST INSTABILITY CONTINUING TO REMAIN ACROSS LOCATIONS APPROACHING THE TN RIVER VALLEY REGION. ALTHOUGH CONVECTION IS WEAKENING... WITH A BROAD AREA OF SHWRS...WITH SOME EMBEDDED TSTMS...REACHING AS FAR E AS THE I-65 CORRIDOR AROUND 02Z...AND THE LATEST HRRR MODEL INITIALIZING THIS OVERALL WX PATTERN BETTER...WILL GO AHEAD WITH INCREASING SHWR/TSTM CHANCES ACROSS THESE AREAS THRU AT LEAST MIDNIGHT...WITH NUMEROUS SHWRS/TSTMS POSSIBLE AS ONE APPROACHES THE TN RIVER VALLEY REGION. BELIEVE THRU THE FIRST PART OF THE EARLY MORNING HRS THAT AT LEAST SCT SHWRS...WITH SOME ISO TSTMS...AROUND UPPER LEVEL RIDGE PERIPHERY...WILL BE POSSIBLE... AND THUS WILL MENTION ALSO. WHILE MAKING THESE CHANGES...TWEAKED HRLY TEMP...DEWPOINT...SKY CONDITION...AND WIND SPEED/DIRECTION GRIDS. PREV DISCUSSION.../ISSUED 750 PM CDT TUE JUL 28 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE MENTION OF LATE AFTERNOON ZONE GROUPING IN ZONE FORECAST PRODUCT AND ALL REFERENCES TO HEAT ADVISORY THAT EXPIRED AT 7 PM THIS EVENING. WILL ALSO UPDATE THE HAZARDOUS WEATHER OUTLOOK PRODUCT TO DO THE SAME. PER REGIONAL RADAR TRENDS...WITH SHWRS/TSTMS MOVING IN FROM THE NW INTO LOCATIONS N OF I-40 AND W OF 1-65...AROUND PERIPHERY OF UPPER LEVEL RIDGING DYNAMICS...WILL KEEP CHANCE POPS ACROSS THIS REGION THRU THE MID EVENING HRS...BUT WITH DIURNAL INFLUENCES GRADUALLY WEAKENING...DUE EXPECT AN OVERALL TREND OF WEAKENING SHWRS/TSTMS THRU THE MID EVENING HRS ALONG WITH A DECREASING TREND IN AREAL COVERAGE. THIS REASONING SUPPORTED BY CONSENSUS OF SHORT RANGE MODEL SOLUTIONS. WILL KEEP A SLIGHT CHANCE OF SHWRS/TSTMS ACROSS THE REST OF THE MID STATE THRU THE EVENING HRS. EVEN THOUGH THERE IS SOME INDICATION IN SHORT RANGE MODELS FOR A PREFERENCE FOR SHWR/TSTM ACTIVITY ACROSS WRN PORTIONS OF THE MID STATE AFTER MIDNIGHT...ONLY EXPECTING ISO SHWRS/TSTMS AT BEST...AND WILL THUS ADDRESS ALL AREAS ACROSS THE MID STATE EXPERIENCING A SLIGHT CHANCE OF SHWRS/TSTMS AFTER MIDNIGHT. ALSO TWEAKED HRLY TEMP...DEWPOINT...SKY CONDITION...AND WIND SPEED/DIRECTION GRIDS. CURRENT TEMPS TRENDS SEEM IN LINE WITH FORECASTED LOW VALUES EXPECTED OVERNIGHT AND THUS NO CHANGES NEEDED. PREV DISCUSSION.../ISSUED 615 PM CDT TUE JUL 28 2015/ AVIATION 00Z DISCUSSION... IMPULSE MOVING SOUTHWARD THROUGH THE MID STATE THIS EVENING. NVA SHOULD MOVE IN AFT 03Z AND END THE OVERNIGHT CONVECTION. HRRR CONCURS WITH RAIN FREE CONDITIONS BY 5Z. WILL OPT TO BE A LITTLE MORE BULLISH WITH THE FOG POTENTIAL AND LOWER THE TEMPORARY VSBY REDUCTIONS. MUCH OF THE AREA IS RAIN COOLED AND DEWPOINT SPREADS ARE RATHER LOW. UPPER HIGH MAY BE IN CLOSER PROXIMITY FOR TOMORROW. HOWEVER...CAPE TO CAP RATIOS WILL BECOME FAVORABLE ONCE AGAIN IN THE AFT. WILL INCLUDE VCNTY/CONVECTION IN TAFS AFT 18Z. PREV DISCUSSION.../ISSUED 509 PM CDT TUE JUL 28 2015/ UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO ADD A LATE AFTERNOON ZONE GROUPING TO THE ZONE FORECAST PRODUCT TO EMPHASIZE SCT SHWR/TSTM CONVECTION ACROSS MID STATE. ALSO ADJUSTED HRLY TEMP...DEWPOINT... WIND DIRECTION/SPEED...AND SKY CONDITION GRIDS. PREV DISCUSSION.../ISSUED 236 PM CDT TUE JUL 28 2015/ DISCUSSION... UPPER RIDGE HAS A STRONGHOLD ON MUCH OF THE AREA WITH HIGH HEAT INDICIES PROMPTING A HEAT ADVISORY FOR A GOOD PART OF THE MID STATE UNTIL 7 PM CDT THIS EVENING. CONVECTION HAS FIRED IN THE AFTERNOON HEAT MAINLY ACROSS EASTERN AREAS AND ALONG THE PLATEAU WITH MORE CONVECTION DROPPING SOUTH BOUND FROM KENTUCKY. LOOKS LIKE A VORTICITY MAX (SHORT WAVE) WORKING DOWN FRONT SIDE OF UPPER RIDGE. VORT MAX CURRENTLY SHOWING UP IN LATEST RUC13 RUN NOSING JUST SOUTH OF OHIO RIVER SOUTH OF LOUISVILLE...HEADED THIS WAY. SHORT WAVE SHOULD ENHANCE CONVECTION OVER SOUTH CENTRAL KENTUCKY THAT WILL WORK DOWN INTO MIDDLE TENNESSEE REMAINDER OF THE AFTERNOON AND INTO THE EVENING. MODELS KEEP SOME CONVECTION AROUND AFTER MIDNIGHT WITH WESTERN AREAS OF THE MID STATE FAVORED. ANOTHER HOT DAY WEDNESDAY WITH AN INCREASED CHANCE OF RAIN AS FRONT APPROACHES FROM THE NORTHWEST. SHOWER AND THUNDERSTORMS WILL RAMP UP WEDNESDAY EVENING AND OVERNIGHT AS FRONT WORKS INTO THE MID STATE. SHOWER AND THUNDERSTORM CHANCES CONTINUE SOUTHEAST HALF ON THURSDAY BUT DRY THURSDAY NIGHT AND THROUGH THE UPCOMING WEEKEND. UPPER RIDGE THAT HAS KEPT TEMPS ABOVE NORMAL AND HEAT INDICIES AROUND TRIPLE DIGITS WILL FINALLY RETROGRADE ALLOWING UPPER TROUGH TO DOMINATE FRIDAY THROUGH THE WEEKEND. NEXT CHANCE FOR RAIN LOOKS TO BE ABOUT THE MIDDLE OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 76 94 75 90 / 40 30 40 30 CLARKSVILLE 75 94 72 87 / 60 30 40 10 CROSSVILLE 71 87 72 84 / 20 30 40 50 COLUMBIA 75 93 74 91 / 60 30 40 40 LAWRENCEBURG 75 90 73 90 / 60 30 40 50 WAVERLY 75 95 73 88 / 60 30 40 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1137 PM CDT TUE JUL 28 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 331 PM CDT TUE JUL 28 2015 LATEST WATER VAPOR SATELLITE IMAGERY SHOWS VIGOROUS SHORTWAVE TROUGH OVER EASTERN IOWA AND SOUTHERN WISCONSIN. LATEST MOSAIC RADAR INDICATING SHOWERS/THUNDERSTORMS HAVE WEAKENED WITH THE SHORTWAVE TROUGH EARLY THIS AFTERNOON. LATEST 19Z SURFACE ANALYSIS SHOWING COLD FRONT EXTENDING FROM WESTERN MINNESOTA INTO EASTERN NEBRASKA. MAIN FORECAST CONCERNS TONIGHT ARE PRECIPITATION CHANCES AND POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING. WITH THE SHORTWAVE TROUGH AND ASSOCIATED PRECIPITATION/CLOUDS OVER THE FORECAST AREA MUCH OF TODAY...THIS HAS ALLOWED THE ATMOSPHERE TO BE CAPPED OVER THE FORECAST AREA. THIS IS EVIDENT WITH THE LATEST 28.18Z RAP BUFKIT SOUNDINGS INDICATING A STRONG INVERSION OVER MUCH OF THE FORECAST AREA. IN ADDITION...THE LATEST 28.17Z HRRR/HOPWRF SHOW VERY LITTLE CONVECTION TO DEVELOP ALONG THE COLD FRONT...DUE TO LACK OF CONVERGENCE ALONG FRONT...AND HINT AT POSSIBLE DEVELOPMENT OF ISOLATED SHOWER/THUNDERSTORM MAINLY EAST OF THE MISSISSIPPI RIVER AFTER 00Z WEDNESDAY. THE HRRR/HOPWRF INDICATE SHOWER/THUNDERSTORM DEVELOPMENT SOUTH OF FORECAST AREA IN CENTRAL IOWA...WHERE BETTER MOISTURE CONVERGENCE AND LIFT IS ALONG OUTFLOW BOUNDARY FROM THIS MORNINGS MCS. DUE TO THE LOSS OF INSTABILITY/FORECAST AREA CAPPED AND LACK OF MOISTURE CONVERGENCE ALONG FRONT...HAVE REDUCED PRECIPITATION CHANCES ACROSS THE FORECAST AREA THIS EVENING/TONIGHT. PLUS...WITH THE BETTER LIFT/MOISTURE CONVERGENCE AND INSTABILITY SOUTH OF THE FORECAST AREA. SEVERE WEATHER THREAT WILL BE CONFINED TO THE FAR SOUTHERN PART OF THE FORECAST AREA OR SOUTH OF THE FORECAST AREA. UPPER LEVEL TROUGH DIGS INTO THE GREAT LAKES REGION AND PRESSURE GRADIENT TIGHTENS BEHIND COLD FRONT ACROSS THE FORECAST AREA WEDNESDAY. THE 28.12Z GFS/NAM BUFKIT SOUNDINGS SUGGEST AREA WILL MIX UP TO AROUND 800MB AND WINDS AT THIS LEVEL INCREASE TO AROUND 30 KNOTS. HAVE INCREASED WINDS/WIND GUSTS ACROSS THE FORECAST AREA...ESPECIALLY IN THE HIGHER TERRAIN AND OPEN AREAS WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 331 PM CDT TUE JUL 28 2015 SURFACE RIDGE BUILDS INTO THE CENTRAL PLAINS THURSDAY INTO FRIDAY. WITH SUBSIDENCE UNDERNEATH HIGH AND MAIN SHORTWAVE ENERGY OVER LAKE SUPERIOR AND SOUTHERN CANADA...FORECAST AREA WILL REMAIN DRY THROUGH THE END OF THE WEEK. MAIN FORECAST CONCERNS FRIDAY NIGHT INTO TUESDAY ARE PRECIPITATION CHANCES THROUGH THE PERIOD. THE 28.12Z GFS/ECMWF/GEM ARE IN DECENT AGREEMENT IN DIGGING UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION THROUGH 00Z SUNDAY...THEN DIVERGE ON THE STRENGTH OF THE UPPER LEVEL TROUGH. WHERE THE 28.12Z GFS/GEM ARE STRONGER WITH THE UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION THAN THE ECMWF. THE 28.12Z GFS/GEM/ECMWF INDICATE DIFFERENCES IN TIMING OF SHORTWAVE TROUGHS EMBEDDED IN THE NORTHWEST FLOW ALOFT OVER THE GREAT LAKES REGION. THE 28.12Z GFS/GEM/ECMWF SUGGEST ENOUGH LIFT AND MOISTURE CONVERGENCE IN ASSOCIATION WITH EACH SHORTWAVE TROUGH TO WARRANT CHANCES OF SHOWERS/THUNDERSTORMS ACROSS MUCH OF THE FORECAST AREA FROM SATURDAY NIGHT INTO TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1137 PM CDT TUE JUL 28 2015 THE FRONT HAS ALREADY PASSED THROUGH KRST THIS EVENING AND WILL HAVE GONE THROUGH KLSE BY 06Z. SHOWERS COMING NORTHEAST OUT OF CENTRAL IOWA SHOULD CONTINUE TO MOVE NORTHEAST WITH THE 29.02Z HRRR-CR SHOWING THESE MISSING KLSE WELL TO THE SOUTHEAST...SO DO NOT PLAN TO INCLUDE ANY MENTION OF SHOWERS OR STORMS IN EITHER TAF. STILL EXPECTING A BREEZY DAY WEDNESDAY ONCE THE INVERSION MIXES OUT WITH WEST WINDS GUSTING INTO THE 25 TO 30 KNOT RANGE FOR THE LATE MORNING THROUGH THE AFTERNOON. LOOKS LIKE THESE WINDS SHOULD SETTLE DOWN EARLY WEDNESDAY EVENING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DTJ LONG TERM...DTJ AVIATION...04
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
958 AM MDT WED JUL 29 2015 .UPDATE... ISSUED AT 958 AM MDT WED JUL 29 2015 SCATTERED RAIN SHOWERS HAVE DEVELOPED OVER LINCOLN COUNTY ON THE NORTHERN FRINGE OF THE MONSOONAL MOISTURE MOVING OVER THE STATE OUT OF NEW MEXICO. THE HRRR MODEL MOVES THESE SHOWERS OFF TO THE EAST OVER THE NEXT COUPLE HOURS WITH DRY WEATHER THEN CONTINUING THROUGH THE AFTERNOON ACROSS THE FORECAST AREA. THE LATEST RUN OF THE NAM ALSO SHOWS THE FORECAST AREA REMAINING DRY THIS AFTENROON AND EVENING AFTER THE THE LINCOLN COUNTY SHOWERS DISSIPATE. CURRENT FORECAST FOR THIS AFTERNOON SHOWS LOW POPS OVER PARK COUNTY AND THE PALMER DIVIDE...WHICH WILL REMAIN UNCHANGED TO ACCOUNT FOR THE PRESENCE OF MOISTURE TO OUR SOUTH. ADDING A COUPLE HOURS OF SCATTERED SHOWERS TO THE PALMER DIVIDE THIS MORNING WILL BE THE ONLY CHANGE TO THE FORECASTS AT THIS TIME. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 349 AM MDT WED JUL 29 2015 A WEST-SOUTHWEST FLOW ALOFT WILL PREVAIL AS AN UPPER LEVEL RIDGE REMAINS OVER THE SOUTHERN PLAINS. A FEW SHOWERS HAVE FORMED THIS MORNING OVER LINCOLN COUNTY AND ARE EXPECTED TO MOVE EAST OF THE AREA. MONSOON MOISTURE WILL REMAIN OVER THE STATE...WITH THE GREATEST MOISTURE BEING OVER THE SOUTHEAST COLORADO. PRECIPITABLE WATER VALUES WILL BE THREE-QUARTERS OF AN INCH TO ONE INCH. HOWEVER...AIRMASS WILL BE STABLE OVER THE PLAINS AND SLIGHTLY UNSTABLE ALONG THE FRONT RANGE AND OVER THE HIGHER TERRAIN WHERE CAPES WILL BE LESS THAN 500 J/KG. BEST CHANCE FOR A SHOWER OR STORM WILL BE SOUTH AND OVER THE HIGHER TERRAIN THIS AFTERNOON AND EVENING. SURFACE HIGH WILL MOVE FROM THE NORTHERN ROCKIES TO CENTRAL PLAINS. THIS WILL PRODUCE SOUTHEAST WINDS TO WITH GUSTS THIS AFTERNOON UP TO 25 MPH. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY`S READINGS WITH HIGHS IN THE 80S OVER NORTHEAST COLORADO. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 349 AM MDT WED JUL 29 2015 ON THURSDAY...A BROAD UPPER LEVEL RIDGE WILL STRETCH FROM SRN CALIFORNIA TO THE SERN GULF STATES AND ALONG ITS NORTHERN PERIPHERY 60-80KT MID-LEVEL ZONAL FLOW. BENEATH THE WRN SECTOR OF THIS RIDGE WILL BE A PLUME OF SUBTROPICAL MOISTURE WHICH MODELS SHOW NUDGING NORTHWARD OVER SRN COLORADO. FROM THERE THEY SHOW THE MAIN CORE OF THIS MOISTURE BEING SHEARED EASTWARD AWAY FROM NERN COLORADO AND THE FRONT RANGE. HOWEVER LATE ON THURSDAY...MODELS ALSO SHOW SELY SFC- 700MB ON THE PLAINS OF COLORADO DRIVING A LOW-LEVEL MOISTURE/THETA-E RIDGE UP INTO NERN COLORADO. BY THURSDAY EVENING...NAM INDICATES 750- 1000 J/KG OF SFC BASED CAPE ACROSS DOUGLAS...ELBERT AND LINCOLN COUNTIES. GFS AND ECMWF CAPES ARE SPREAD OUT ACROSS THE PLAINS WITH THE HIGHER VALUES APPROACHING A 1000 J/KGS ACROSS THE SERN CORNER OF THE CWA. IF IT WERE NOT FOR THE WARM TEMPERATURES ALOFT AND STG CAP UP AROUND 550 MBS...ERN SECTIONS OF THE FCST AREA COULD END UP SEEING MORE THAN JUST A FEW LOW TOP T-STORMS PRODUCING NO MORE THAN A RAIN SHOWER AND GUSTY WINDS. THAT SAID...HAVE SLIGHTLY RAISED PRECIP CHANCES OVER THE FRONT RANGE AND ALONG THE PALMER DIVIDE OUT ACRS LINCOLN COUNTY THURSDAY AFTERNOON AND EVENING. AREAS ROUGHLY NORTH OF DENVER SHOULD ESCAPE ANY PRECIP OR STORMS AS THIS AIR APPEARS DRIER AND TOO CAPPED. HIGHS ON THURSDAY ONLY SLIGHTLY WARMER THAN WEDNESDAY AND SLIGHT A 1-2DEGS C BELOW AVERAGE FOR THE DATE. FOR FRIDAY...THE UPPER RIDGE IS FORECAST TO BUILD NORTHWESTWARD UP OVER THE GREAT BASIN PLACING NERN COLORADO MORE UNDER NWLY FLOW ALOFT. THIS LEADS TO DRYING ALOFT BUT NOT MUCH IN THE WAY OF COOLING. THIS AMPLIFICATION ON THE RIDGE ALLOWS FOR SOME SUBTROPICAL MOISTURE POOLING OVER NEW MEXICO/ERN ARIZONA TO FLOW NORTHWARD ALONG THE SPINE OF THE COLORADO ROCKIES. PW CHARTS SHOW HIGH COUNTRY VALUES CREEPING UP THROUGH THE DAY WITH THE NAM AND GFS INDICATING POCKETS OF LIGHT QPF OVER AND NEAR THE FRONT RANGE BY AFTERNOON. HOWEVER THE EC AND SREF SHOW THE BULK OF THIS LIGHT PRECIP FARTHER OUT ON THE PLAINS IN PROXIMITY OF GREATER LOW-LEVEL MOISTURE... ELEVATED CAPE AND SHEAR VALUES. FOR NOW WILL HOLD ONTO 20-30PCT POPS OVER THE HIGH TERRAIN...AND 10-20PCT POPS MAINLY OVER THE PALMER DIVIDE AND ADJACENT PLAINS THRU EVENING ON FRIDAY. LOOKING AHEAD TO THE PERIOD SATURDAY-WEDNESDAY...THE UPPER RIDGE CONTINUES TO BULGE NORTHWESTWARD TOWARDS THE PACIFIC NORTHWEST OVER THE WEEKEND...PLACING THE FCST AREA UNDER A DRIER AND MORE STABLE NORTHWESTERLY MID-LEVEL FLOW. THEREFORE SHOULD SEE LESS STORM ACTIVITY ON SATURDAY...WITH THE BETTER CHANCE OF T-STORMS WITH STEEPER LAPSE RATES OVER THE HIGHER TERRAIN. ON SUNDAY...MODELS SHOW THE UPPER RIDGE SHIFTING EAST WITH LIGHT W-NWLY FLOW OVER THE CWA. SUBTROPICAL MOISTURE TRAPPED BENEATH THE RIDGE COUPLED WITH STG DAYTIME HEATING MAY RESULT IN A BIT MORE T-STORM COVERAGE IN THE HIGH COUNTRY. SO RAISED POPS SLIGHTLY UP THERE. DO NOT SEE MUCH CONVECTIVE ACTIVITY ON THE PLAINS. HIGHS ON SATURDAY AND SUNDAY CONTINUE TO CREEP UP WITH READING RETURNING TO NEAR TO SLIGHTLY ABOVE AVERAGE. MONDAY THROUGH WEDNESDAY...THE UPPER RIDGE IS PROGGED TO REMAIN OVER THE ROCKY MTN REGION WITH LITTLE DAY-TO-DAY CHANGE IN WEATHER. EXPECT NEAR AVERAGE TEMPS AND A SLIGHT CHANCE OF AFTERNOON AND EVENING T-STORMS MTNS AND PLAINS EACH DAY. && .AVIATION...(FOR THE TAFS THROUGH 18Z THURSDAY MORNING) ISSUED AT 958 AM MDT WED JUL 29 2015 MANAGING WIND SHIFTS AT THE AIRPORT THROUGH THIS AFTERNOON WILL BE THE ONLY FORECAST PROBLEM OF THE DAY TODAY. SOUTHEASTERLY FLOW ACROSS THE PLAINS IS FORECAST TO PERSIST THROUGH THE AFTERNOON WHICH WILL PRODUCE SOUTH TO SOUTHEASTERLY WINDS AT KDEN THROUGH THIS EVENING. THE TRANSISTION BACK TO NOCTURNAL SOUTHERLIES SHOULD THEN OCCUR BETWEEN 02Z AND 04Z. NO OTHER AVIATION IMPACTS TODAY. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...DANKERS SHORT TERM...MEIER LONG TERM...BAKER AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
9 AM EDT WED JUL 29 2015 .DISCUSSION... PER THE 29/12Z SOUNDINGS THE 500MB TROUGH AXIS LOOKS TO HAVE PUSHED SOUTH TO THE LAKE OKEECHOBEE AREA. THE 12Z/8AM BUOY REPORTS INDICATE THAT THE SURFACE TROUGH AXIS WAS STILL LAGGING BACK TO AROUND THE CAPE CANAVERAL AREA. WATER VAPOR LOOP SHOWS RELATIVELY DRIER MID/UPPER LEVEL AIR MASS TRYING TO WORK ITS WAY ACROSS NORTH FLORIDA AND TOWARD CENTRAL FLORIDA. THE 12Z SOUNDINGS INDICATE PRECIPITABLE WATER VALUES STILL HIGH AND RANGE FROM 1.95 AT TALLAHASSEE TO 2.26 AT CAPE CANAVERAL. RAIN CHANCES TO REMAIN HIGH RANGING FROM AROUND 50 PERCENT NORTH TO 30 PERCENT SOUTH. MODELS BOTH LONGER TERM/GFS AND SHORT TERM MODELS SUCH AS THE HRRR AND LOCAL WRF/S INDICATE THAT THE LOW OFF THE FLORIDA EAST COAST WILL CONTINUE TO TRACK AWAY FROM FLORIDA. THE WINDS SHOULD SHIFT TO THE NORTHWEST THROUGH NORTHEAST DURING THE DAY. PARTLY CLOUDY SKIES NORTH AND WINDS SPEEDS LOOK LIGHT ENOUGH TO ALLOW FOR AFTERNOON SEA BREEZES. .AVIATION...SCATTERED TEMPO MVFR CONDITIONS DUE TO LOW CLOUDS AND MIST/FOG UNTIL 29/1400Z. WARM TEMPERATURES ALOFT HOLD DOWN THUNDERSTORMS PROBABILITY SO WILL KEEP VCTS FOR THE AFTERNOON. .MARINE...BUOYS RECORDING SOUTHWEST WINDS 5 TO 10 KNOTS AT THE COAST AND NEARSHORE...AND 15 TO 20 KNOTS AT BUOY 010 AT 12NM OFFSHORE. THE OUTLIER WAS THE CMAN AT SAINT AUGUSTINE WHERE THE WIND WAS NORTHWEST AT 5 TO 10 KNOTS. WINDS FORECAST TO SHIFT TO THE NORTHWEST AND NORTH DURING THE DAY AS LOW PRESSURE OFF NORTHEAST AND CENTRAL FLORIDA TRACKS EAST INTO THE ATLANTIC. WINDS LOOK LIGHT ENOUGH TO ALLOW FOR AN ONSHORE WIND DOWN TO AT LEAST SEBASTIAN INLET IN THE AFTERNOON. PREVIOUS AFD TODAY-TONIGHT...LOCAL WEATHER PATTERN CONTINUES TO BE DRIVEN BY THE DIFFUSE LOW LEVEL BOUNDARY MEANDERING ACROSS THE NORTH/CENTRAL PENINSULA. LATEST SURFACE ANALYSIS SHOWS A BROAD AND WEAK SURFACE LOW OVER NE FLORIDA AND ADJACENT ATLANTIC WITH THE LOW LEVEL BOUNDARY MARKED BY A SLIGHT WIND SHIFT SOMEWHERE IN NORTH FLORIDA/S GEORGIA. MODELS SHOW SURFACE LOW CONSOLIDATING OF TO OUR NE OVER THE NEXT 24 HOURS (THOUGH WITH LITTLE IN THE WAY OF DEEPENING)...WHICH WILL BE ENOUGH TO DRIVE THE BOUNDARY A LITTLE FURTHER SOUTH AND MORE SOLIDLY BACK INTO CENTRAL FLORIDA. THIS OCCURS WHILE THE UPPER LEVEL TROUGH AXIS ALSO SHIFTS MORE SOUTHEAST THIS AFTERNOON. THE NET RESULT IS THAT THE NARROWING DEEP MOISTURE BAND ASSOCIATED WITH THESE FEATURES WILL BE PUSHED A LITTLE MORE SOUTHWARDS TODAY AS THE PREVAILING LOW-MID LEVEL FLOW ALSO BECOMES MORE WEST-NORTHWEST. MODELS SHOW SHOWER/STORM COVERAGE NOT QUITE AS HIGH AS THE PAST FEW DAYS...THOUGH STILL NEAR TO ABOVE NORMAL AT 30-50%. PINPOINTING THE HIGHEST RAIN COVERAGE WILL BE SOMEWHAT COMPLEX GIVEN WHERE THE BOUNDARY ENDS UP AND HOW MUCH DRY AIR MANAGES TO WORK ITS WAY IN. UPSTREAM 29/00Z SOUNDING AT JAX HAD A PWAT OF ONLY 1.55"...MUCH BELOW THE 2"+ AT TAMPA AND THE CAPE...BUT INDICATES DRIER AIR IS NOT TOO FAR AWAY. ALSO WINDS LOOK LIGHT ENOUGH FOR A SEA BREEZE TO DEVELOP NORTH OF THE CAPE IN THE AFTERNOON...WHICH IN COMBINATION WITH DRIER AIR WILL LIKELY SHIFT RAIN AWAY FROM THE NORTHERN COASTAL AREAS INTO THE I-4 CORRIDOR. ATMOSPHERE REMAINS WARM ALOFT SO WILL CONTINUE TO WORD FOR SCATTERED SHOWERS AND ISOLATED STORMS. THU-WEEKEND...PLAINS MID/UPPER ANTICYCLONE WILL SLOWLY RETROGRADE WHILE TROUGH GRADUALLY DIGS IN OVER THE EASTERN CONUS. WEAK CUT OFF LOW EAST OF THE WATERS EARLY SHOULD SHEAR OUT BY SUNDAY AS THE EASTERN TROUGH DIGS. THE MODELS DO NOT SHOW MUCH SUBSIDENCE/DRYING ON THE BACK SIDE OF THIS LOW AND KEEP PRECIPITABLE WATER VALUES 2 INCHES OR GREATER THROUGH MOST OF THE PERIOD. ADDITIONALLY...MID LEVEL TEMPS WILL COOL SLIGHTLY TO AROUND MINUS 7 CELSIUS. EXPECT THIS WILL LEAD TO AN OVERALL GREATER COVERAGE OF STORMS WITH INCREASED LIGHTNING ACTIVITY. STEERING FLOW WILL GRADUALLY WEAKEN...BUT WITH LOW LEVEL RIDGE SUPPRESSED TO THE SOUTH PROVIDING SOUTHWEST FLOW...SUFFICIENT FOCUSING FOR STORMS WILL EXIST OVER THE EASTERN SIDE OF THE PENINSULA. MOS/CONSENSUS POPS ARE ABOUT 50-60 PERCENT THROUGH THE PERIOD AND SEE NO REASON TO DIFFER FROM THEM. MON-WED...THE MODELS SHOW ATLANTIC RIDGE BUILDING BACK ACROSS THE PENINSULA WED AS THE EASTERN CONUS TROUGH LIFTS AND SOUTHERN EXTENSION INTO FLORIDA SHIFTS WEST OVER THE GULF OF MEXICO. THIS REPRESENTS A DELAYED TREND THOUGH...SO EXPECT MOISTURE TO REMAIN HIGH AND POPS 50 PERCENT OR A LITTLE HIGHER SEEM WARRANTED...EXCEPT POSSIBLY TRENDING LOWER WED...IF RIDGE DOES INDEED BUILD BACK INTO CENTRAL FLORIDA. && .AVIATION... PATCHY MVFR AND IFR CIGS PRESENT AGAIN THIS MORNING THOUGH WITH CONSIDERABLY LESS AREAL EXTENT THAN THE PAST FEW NIGHTS. WILL KEEP THE MENTION OF SCT LOW CLOUDS IN SITES THAT HAVE BEEN REPORTING THE STRATUS AND MONITOR FOR BKN-OVC CONDITIONS. OVERALL THINK ANY CIGS WILL BE VERY SHORT LIVED. THE BOUNDARY THAT HAS BEEN FLIRTING WITH THE REGION DROPS BACK SOUTHWARDS THIS MORNING AND SITES FROM KMLB-KLAL NORTHWARDS WILL SEE A NW WIND COMPONENT THROUGH MIDDAY. SPEEDS WILL BE LIGHT ENOUGH FOR SEA BREEZE DEVELOPMENT NORTH OF KTTS...POSSIBLY REACHING AS FAR INLAND AS KDED IN THE LATE AFTERNOON. SCT SHRA/ISOLD TSRA DEVELOPING ACROSS THE REGION AFTER 15Z. TEMPO IFR CIGS/VSBYS WITH ANY CONVECTION WITH A FEW GUSTS TO 35KTS. && .MARINE... TODAY-TONIGHT...WEAK FRONTAL TROUGH PUSHES SOUTHWARD INTO CENTRAL FLORIDA WITH N/NW WINDS DEVELOPING NORTH OF THE CAPE TOWARDS DAYBREAK THIS MORNING WITH WINDS FURTHER SOUTH REMAINING W/SW. LOCAL OBSERVATIONS SHOW SPEEDS HAVE WEAKENED TO 10-15KTS WITH MODELS SHOWING SPEEDS AROUND THIS LEVEL THROUGH THE REMAINDER OF THE DAY SO WILL NOT EXTEND CAUTIONARY STATEMENT. NORTH OF THE CAPE...FLOW WILL BE LIGHT ENOUGH TO ALLOW SEA BREEZE TO DEVELOP WITH WINDS BECOMING VARIABLE TO EAST-NORTHEAST IN THE AFTERNOON. W/SW FLOW RE- ESTABLISHES OVER ALL THE WATERS OVERNIGHT. SEAS WILL BE AROUND 2FT NEARSHORE 2-3 FEET OFFSHORE. COVERAGE OF STORMS NOT QUITE AS HIGH AS PREVIOUS FEW DAYS WITH STORM MOTION BECOMING MORE TO THE SOUTH. HOWEVER STILL COULD SEE A FEW STORMS PUSHING OFF THE COAST SOUTH OF THE CAPE. THU-FRI...SURFACE RIDGE AXIS WILL REMAIN SUPPRESSED TO THE SOUTH. THE PRESSURE GRADIENT LOOKS LIKE IT WILL SUPPORT SOUTHWEST WINDS AROUND 10 KNOTS NEAR SHORE AND 10 TO 15 KNOTS IN THE OUTER WATERS. MID LEVEL WIND FLOW IS FORECAST TO WEAKEN BUT WINDS IN THE LOWER PORTION OF THE ATMOSPHERE OUT OF THE WEST LOOK SUFFICIENT TO PUSH STORMS OFF THE PENINSULA INTO THE ATLANTIC WATERS. COVERAGE LOOKS RATHER HIGH AND STORMS SHOULD START TO PRODUCE MORE FREQUENT LIGHTNING STRIKES. WEEKEND...LITTLE CHANGE IN THE MOIST SOUTHWEST WIND FLOW REGIME. BOATERS SHOULD CONTINUE TO BE VIGILANT FOR MARINE STORMS... ESPECIALLY DURING THE AFTERNOON AND EVENING. && .PRELIMINARY POINT TEMPS/POPS... DAB 92 75 91 75 / 50 20 60 30 MCO 94 76 91 75 / 50 20 60 30 MLB 92 74 90 74 / 50 20 60 30 VRB 91 73 91 74 / 50 20 60 40 LEE 92 77 90 77 / 50 20 60 30 SFB 92 77 91 76 / 50 20 60 30 ORL 94 77 91 76 / 50 20 60 30 FPR 91 74 91 74 / 40 20 60 40 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ IMPACT WX...PENDERGRAST FORECASTS...WIMMER
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
647 AM EDT WED JUL 29 2015 .SYNOPSIS... ISSUED AT 305 AM EDT WED JUL 29 2015 A WEAK FRONT WILL PASS THROUGH THE GREAT LAKES TODAY BRINGING THE CHANCE FOR A FEW SHOWERS AND THUNDERSTORMS...MAINLY THIS AFTERNOON. HIGHS WILL RANGE FROM LOWER 80S NEAR LAKE MICHIGAN TO THE UPPER 80S IN NORTHWEST OHIO. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 305 AM EDT WED JUL 29 2015 POTENT SW DISTURBANCE OVR SRN MB WILL CARRY NEWD INTO JAMES BAY BY THU AM AS TRAILING SFC BNDRY WASHES OUT ACRS THE LAKES THIS AFTN. DOWNSTREAM LL FLW WITHIN EWD FOLDING LL THETA-E RIDGE HWVR REMAINS WK W/H85 WRLY WINDS OF 15KTS OR LESS. THUS IN COMBINATION W/EWD STREAM OF CONV CLD DEBRIS THROUGH THIS MORNING AND GENERAL POOR FNTL BASED FORCING AS ASSOCD HGT FALLS W/SW PASS WELL NORTH. ALL THE MORE REASON TO BACK OFF ON POPS ESP WRN PORTIONS EARLY ON EVEN IN LIGHT OF RECENT CONV CLUSTER ACRS NE IL WHICH IS XPCD TO DECAY EWD INTO FAR NW INDIANA PRIOR TO SUNRISE. MEANWHILE MOST AGREEABLE SHRT TERM GUIDANCE SUGGESTS SOME ISOLD-SCT STORM DVLPMNT PLAUSIBLE AFT 18Z IN ERN AREAS...I-69 EAST AND GENERALLY FOLLOWED. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 305 AM EDT WED JUL 29 2015 UPPER LEVEL LOW CURRENTLY MOVING NORTHEAST THROUGH THE PLAINS WILL HEAD TOWARDS HUDSON BAY AND REMAIN IN THE GENERAL AREA THROUGH MUCH OF THE EXTENDED PERIOD. SERIES OF WAVES WILL ROTATE THROUGH THE FLOW AND MAKE HEADWAY TOWARDS THE GREAT LAKES EVERY FEW DAYS. BEST FOCUS FOR CHANCES APPEARS TO BE IN THE SUNDAY TO MONDAY TIME FRAME WHEN PLUME OF MSTR MOVES IN AHEAD OF A SLIGHTLY MORE PRONOUNCED WAVE TO GIVE SOMEWHAT BETTER CHANCES FOR MEASURABLE RAIN. GRIDS GENERALLY LEFT ALONE WITH MODELS CONTINUING TO FLIP FLOP ON TIMING/LOCATION OF BEST CHANCES. TEMPERATURES WILL REMAIN SEASONABLE IN THE LOWER TO MIDDLE 80S FOR HIGH THROUGH MUCH OF THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 645 AM EDT WED JUL 29 2015 VFR CONDS XPCD THROUGH THIS PD. LTL CHANGE FM PRIOR THINKING WRT WEAKLY FORCED FNTL BNDRY THAT WILL PUSH ACRS THE TERMINALS THIS AFTN. HWVR BASED ON NR TERM HRRR TRENDS AND XPCD UPSTREAM DECAY OF NE IL MCS...DELAYED MENTION AT KFWA A BIT LTR. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...T SHORT TERM...T LONG TERM...FISHER AVIATION...T 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 GRAND RAPIDS MI
1151 AM EDT WED JUL 29 2015 LATEST UPDATE... HYDRO .SYNOPSIS... ISSUED AT 330 AM EDT WED JUL 29 2015 SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A COLD FRONT CROSSES THE REGION. GUSTY WESTERLY WINDS BEHIND THE FRONT WILL USHER IN MORE COMFORTABLE LESS HUMID AIR FOR THE REMAINDER OF THE WEEK ALTHOUGH HIGHS WILL REMAIN IN THE LOWER TO MID 80S. && .UPDATE... ISSUED AT 1044 AM EDT WED JUL 29 2015 DECREASED POPS A BIT BASED ON RADAR TRENDS. A WEAK COLD FRONT IS MOVING ACROSS LAKE MICHIGAN ATTM AND MAY KICK OFF A STORM OR TWO THIS AFTERNOON MAINLY ACROSS THE EASTERN CWA. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 ISOLATED SHOWERS HAVE DEVELOPED OVERNIGHT ON THE LEADING EDGE OF THE HIGHER PRECIPITABLE WATER AROUND TWO INCHES MOVING IN FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. SUSPECT COVERAGE OF SHOWERS WILL REMAIN RATHER LIMITED THIS MORNING ACROSS SW LWR MI AS MORE EXPANSIVE AREA OF CONVECTION IMPACTS IOWA AND ILLINOIS. OUR BEST PROSPECT FOR BETTER COVERAGE OF STORMS WILL BE THIS AFTERNOON EAST OF HIGHWAY 131 WHERE SB CAPES NEAR 1500 J/KG ARE PROGGED JUST AHEAD OF THE FRONT. RUC FCST SOUNDINGS EXHIBIT STEEP LOW LEVEL LAPSE RATES WITH SFC TO 3 KM VALUES AROUND 8.5C NEAR JXN. BASED ON THE HIGH PWAT VALUES OF UP TO 2.25 INCHES WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF SOME TORRENTIAL RAINFALL AND POSSIBLY A LOCALIZED WET MICROBURST DAMAGING WIND EVENT. CONVECTION ENDS FROM WEST TO EAST 18Z-22Z WITH THE PASSAGE OF THE FRONT THEN DECREASING CLOUDS AND FALLING SFC DEW PTS EXPECTED. BREEZY CONDITIONS LIKELY THURSDAY ONCE DEEPER MIXING COMMENCES. SOME GUSTS TO 30 MPH WILL BE POSSIBLE IN THE AFTERNOON. HAVE KEPT FRIDAY DRY FOR NOW ALTHOUGH SOME SMALL POPS MAY NEED TO BE ADDED IN LATER FCSTS AS NEXT WEAK SFC FRONT/TROUGH DROPS SOUTH. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 THERE HAS NOT BEEN MUCH CHANGE OVER THE THE PAST FEW DAYS WITH REGARD TO THE EXPECTED PATTERN. WE CONTINUE TO EXPECT LITTLE TO NO RAIN THROUGH SAT...BEFORE AN UNSETTLED WEATHER PATTERN TAKES SHAPE LATER THIS WEEKEND AND INTO NEXT WEEK. WE HAVE CONTINUED WITH A DRY FCST FOR THE FRI NIGHT AND SAT TIME FRAME FOR NOW. WE WILL SEE WHAT IS LEFT OF THE WEAKENING COLD FRONT TRYING TO MOVE THROUGH ON FRI SLIP SE OF THE AREA FRI EVENING. WE CAN NOT RULE OUT A SHOWER DEVELOPING NEAR THIS FRONT...HOWEVER THE CHC IS LOW ENOUGH TO LEAVE OUT OF THE FCST FOR THE TIME BEING. A LACK OF MOISTURE WITH THE FRI FRONT WILL ONLY DIMINISH BY SAT AS THE FRONT MOVES OUT. THERE IS NOT REALLY SIGNIFICANTLY COOLER AIR BEHIND THIS...SO WE CONTINUE TO EXPECT HIGHS AROUND 80. THE CHCS OF RAIN DOES GO UP ON SUN...AND WILL CONTINUE THROUGH THE END OF THE PERIOD ON TUE. THE AREA WILL BE UNDER THE INFLUENCE OF BROAD LONG WAVE TROUGHING CENTERED WELL NORTH IN CANADA. WE WILL SEE THE JET CORE DROP A LITTLE FURTHER SOUTH WITH A TRAIN OF SHORT WAVES HELPING THIS CAUSE. BEING CLOSER TO THE JET...WE WILL HAVE MORE OF AN OPPORTUNITY FOR THE SHORT WAVES TO DIRECTLY IMPACT THE AREA. WE WILL ALSO SEE THE LOW LEVEL FLOW BECOME A LITTLE MORE FAVORABLE TO BRING SUFFICIENT MOISTURE TO THE AREA FOR RAIN. EXACT TIMING OF THE SHORT WAVES WILL BE PROBLEMATIC AS IS USUAL IN A PATTERN LIKE THIS. TEMPERATURES DO NOT LOOK TO BE TOO BAD IN THIS PATTERN. THE UNSEASONABLY COOL AIR WILL REMAIN JUST NORTH OF THE STATE...NORTH OF THE JET CORE. WE WILL SEE AVERAGE TO JUST SLIGHTLY BELOW AVERAGE TEMPS DURING THIS PERIOD FOR OUR AREA. THIS EQUATES TO HIGHS GENERALLY AROUND 80 AND LOWS AROUND 60. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 745 AM EDT WED JUL 29 2015 IT SHOULD REMAIN VFR FOR THE MOST PART TODAY DESPITE A COLD FRONT WITH SCATTERED SHOWERS MOVING THROUGH. HOWEVER SOME BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE WHERE/WHEN THE SHOWERS ARE OCCURRING. THE BEST CHANCE OF TSTMS WILL BE FROM ABOUT 17Z TO 22Z EAST OF A GRR-AZO LINE. SKIES WILL CLEAR FROM WEST TO EAST AFTER 18Z WITH WINDS INCREASING OUT OF THE WEST TO 12-22KTS. CLR SKIES AND WEST WINDS OF 5-10 KTS ARE EXPECTED AFTER 00Z TONIGHT. && .MARINE... ISSUED AT 330 AM EDT WED JUL 29 2015 CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA LATE TONIGHT AND EARLY THURSDAY DUE TO STRONG WESTERLY FLOW BEHIND THE COLD FRONT. THIS WILL NEED TO BE MONITORED. THIS SITUATION COULD ALSO SUPPORT BEACH HAZARD STATEMENTS ESPECIALLY CONSIDERING THE CURRENT WARM WATER TEMPERATURES AND OVERALL ATTRACTIVE BEACH CONDITIONS SUPPORTIVE OF A HIGH BEACH POPULATION. && .HYDROLOGY... ISSUED AT 1151 AM EDT WED JUL 29 2015 RIVER LEVELS ARE FALLING AND WELL BELOW BANKFULL. THE MAIN CHANCE OF RAIN IN THE NEXT 7 DAYS WOULD BE SUNDAY INTO MONDAY NIGHT. LOCALLY HEAVY RAIN IS POSSIBLE... BUT ONLY PONDING OF WATER IS EXPECTED AWAY FROM THE RIVERS. RIVERS MAY SHOW RISES... BUT SHOULD NOT REACH BANK FULL LEVELS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...04 SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...NJJ AVIATION...MEADE HYDROLOGY...63 MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1105 AM EDT WED JUL 29 2015 .UPDATE... ISSUED AT 1054 AM EDT WED JUL 29 2015 ONE LONE RAIN SHOWER JUST NORTH OF BELLAIRE IN ANTRIM COUNTY. STILL BELIEVE THAT THERE IS SOME INCREASED CHANCE FOR RAIN SHOWERS AND PERHAPS A FEW THUNDERSTORMS ACROSS NE LOWER THIS AFTERNOON. HEATING IS UNDERWAY WITH SFC BASED TEMPS ALREADY CLIMBING INTO THE MIDDLE 80S WITH SFC TD`S AVERAGING IN THE MIDDLE 60S...ON THE WAY TO CAPE VALUES DISCUSSED IN PREVIOUS UPDATE. UPDATE ISSUED AT 805 AM EDT WED JUL 29 2015 IMPACT WEATHER: SCATTERED THUNDERSTORMS DEVELOPING THROUGH THE DAY. SYNOPTIC PATTERN AND OBSERVATIONS: MORNING ANALYSIS...LOW PRESSURE WAS PUSHING THROUGH WESTERN ONTARIO WHILE DRAGGING A COLD FRONT ACROSS CENTRAL LAKE SUPERIOR...EASTERN WISCONSIN AND ILLINOIS. SFC OBS...UPPER AIR AND HI-RES THETA-E ANALYSIS SHOWING A WARM FRONT OUT AHEAD OF THE COLD FRONT...DRAPED FROM CENTRAL LAKE MICHIGAN TO NRN INDIANA. THIS LEAVES A RATHER NARROW "WARM SECTOR" THAT WAS PROGRESSING INTO THE REGION...WIDEST THOUGH ACROSS THE SRN CWA. SCATTERED SHOWERS WERE SEEN ACROSS SRN WI AND SRN LAKE MICHIGAN...IN THE WARM SECTOR...FORCED BY SOME UPPER DIVERGENCE IN RIGHT ENTRANCE REGION OF 100+KT JET OVER MN. ALSO IN PLAY...WEAK VORTICITY MAXIMA IN THE SRN END OF THE BETTER SW FLOW ALOFT ACROSS THIS REGION. THERE WAS NOTHING ON THE FRONT NORTH OF THIS FORCING. LAPSE RATES ALOFT WERE NOT TOO GOOD AT 5.0 C/KM AND THE RESULTING CAPE WAS MINIMAL TO NONE AT THE MOMENT. WIND FIELDS ARE ALSO PATHETIC RIGHT NOW...BUT STRONGER WINDS AND RESULTANT 0-6KM BULK SHEAR OF 25-30KTS WAS ACROSS SRN WISCONSIN...GETTING A LITTLE BETTER. THROUGH THE DAY...AFOREMENTIONED WARM/COLD FRONTS LIFT INTO NRN MICHIGAN..WITH WIDEST WARM SECTOR...BETTER PVA/VORTICITY AND POSSIBLE WEAK UPPER DIVERGENCE (ALTHOUGH WE ARE REALLY IN A POOR POSITION OF THE UPPER JET) TO SPREAD ACROSS THE SRN CWA. LAPSE RATES IMPROVE LITTLE...MAXING OUT AT 5.5 C/KM...WHILE THE FRONT MAKES IT TO NE LOWER EARLY TO MID AFTERNOON. THE SITUATION IS NOW PLAYING OUT FOR WARMING/DESTABILIZATION THROUGH THE DAY TO DEVELOP SHOWERS AND SCATTERED THUNDERSTORMS ALONG THE FRONT. THE MOST INSTABILITY WE SEEM TO BE ABLE TO GENERATE WILL BE SOMEWHERE BETWEEN 200 J/KG IN EASTERN UPPER...TO AS MUCH AS 700-800 J/KG SOUTH. THIS IS MORE THAN LIKELY NOT GOING TO RESULT IN ANY CHANCE OF ORGANIZED STORMS/SEVERE WEATHER....EVEN WITH INCREASING WINDS/0-6KM BULK SHEAR THROUGH THE DAY. DO BELIEVE THAT SHOWERS WILL SLOWLY INCREASE THROUGH THE MORNING WITH THE CHANCE OF THUNDERSTORMS INCREASING ALONG/AHEAD OF THE FRONT THROUGH THE LATE MORNING/EARLY AFTERNOON. && .NEAR TERM...(TODAY THROUGH TONIGHT) ISSUED AT 331 AM EDT WED JUL 29 2015 PERSISTENT HIGH PRESSURE HAS SHIFTED EAST OF MICHIGAN EARLY THIS MORNING AS A COLD FRONT APPROACHES FROM THE WEST. MID AND HIGH CLOUDS HAVE BEGUN TO INCREASE ALONG THE NE PERIPHERY OF THE CONVECTIVE CLOUD SHIELD GENERATED FROM THE MCS CURRENTLY IMPACTING IOWA...NRN MISSOURI AND NRN ILLINOIS. THIS CONVECTION IS FUELED BY A STRONG INSTABILITY AXIS (CAPES OF AROUND 3000 JOULES) AND 850 MB THETA E RIDGING PUNCHING THRU THE MISSISSIPPI VALLEY ATTM. FURTHER NORTH...OUR UPSTREAM RADARS SHOW A FEW SHOWERS AND EMBEDDED WEAK STORMS TRYING TO DEVELOP JUST EAST OF THE ARROWHEAD OF MINNESOTA OVER WRN LAKE SUPERIOR JUST AHEAD OF THE APPROACHING COLD FRONT. CONVECTION IS STRUGGLING DUE TO WEAK INSTABILITY (500 JOULES OR LESS) AND VERY LIMITED MOISTURE. LATEST NAM12...RAP13 AND HRRR ALL SUGGEST THE FOCUS FOR MEANINGFUL CONVECTIVE DEVELOPMENT WILL STAY SOUTH OF OUR CWA THRU TODAY WHERE STRONGER INSTABILITY AND MUCH BETTER MOISTURE WILL RESIDE. NORTHERN MICHIGAN IS ONCE AGAIN LOOKING AT THE PROSPECT THAT THE MAJORITY OF OUR CWA MAY MISS OUT ON AN OPPORTUNITY FOR SOME MUCH NEEDED RAIN TODAY. STILL...CHANCE POPS WILL REMAIN IN ORDER THRU THE DAY...WITH THE EXPECTATION THAT A NARROW LINE OF SCATTERED SHOWERS WITH SOME EMBEDDED THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD FRONT. WILL MAKE SOME MINOR TIMING ADJUSTMENTS TO THIS BAND OF PRECIP AS IT SLOWLY MOVES THRU OUR CWA TODAY...BUT WILL CERTAINLY KEEP POPS IN THE CHANCE CATEGORY. NO REAL CHANCE FOR STRONG TO SEVERE STORMS GIVEN LIMITED INSTABILITY AND MOISTURE AND UNIMPRESSIVE WIND FIELDS AHEAD OF THE FRONT. EXPECT ANOTHER VERY WARM DAY FOR NORTHERN MICHIGAN...BUT NOT AS WARM AS IT HAS BEEN THE PAST FEW DAYS. HIGH TEMPS WILL WARM WELL INTO THE 80S...BUT SHOULD REFRAIN FROM REACHING INTO THE 90S. OVERNIGHT LOWS WILL COOL BACK INTO THE 60S. && .SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT) ISSUED AT 331 AM EDT WED JUL 29 2015 (7/30)THURSDAY...WITH THE FRONTAL PASSAGE TODAY, THE TEMPERATURES FALL BACK TO NORMAL FOR THURSDAY. THERE ARE TWO CONCERNS FOR THE DAY AND INTO THE NIGHT. 1) CLOUD COVER, ESPECIALLY NEAR ANJ. THE 850 MB RH IS AROUND 90%, AND WITH THE 850 MB TEMPERATURES NEAR +10C, NEAR E UPPER, IT COULD BE CLOUDIER. WHICH LEADS TO 2) TEMPERATURES COULD END UP COOLER IF THERE ARE MORE CLOUDS IN E UPPER AND EVEN PARTS OF THE N LOWER IF THE CLOUDS MAKE IT DOWN FAR ENOUGH SOUTH, BUT THAT SEEMS ONLY TO ABOUT M-32 AT THE MOST. SOUTH OF M-32, HOWEVER, THERE IS A DIFFERENT CONCERN, FIRE WEATHER. WILL EXPECT THAT THE HIGH TEMPERATURES WILL REMAIN OVER 75F (CIPS ANALOG GUIDANCE SHOWS 70% AT THE TEMPERATURES>75F). WINDS WILL BE AROUND 15MPH AT THE 20FT LEVEL (SUSTAINED), WITH THE RH AROUND 30- 35%. AND WITH THE EXTENDED DRY PERIOD, WILL BE GOING WITH THE ELEVATED FIRE DANGER. (7/31)FRIDAY...THE DISCUSSION FOR THURSDAY COULD VERY WELL FIT FOR FRIDAY AS WELL, EXCEPT THAT THERE IS A WEAK SFC LOW TRYING TO MOVE INTO THE REGION AS THE 500 MB LOW SINKS A LITTLE MORE SOUTH AND BEGINS TO COOL THINGS DOWN A BIT. AGAIN THE COOLEST, PROBABLY CLOUDIEST AREA WILL BE NORTH OF M-32, WITH THE SOO DROPPING INTO THE LOWER 70S FOR HIGHS POSSIBLY. LOOKS LIKE WE ARE STILL AROUND 80S SOUTH OF M-32, AND WINDS WILL BE AGAIN BE CLOSE TO 15 MPH AT 20FT, SO THERE IS AN ELEVATED FIRE DANGER RISK, ALTHOUGH THE RH MAY NOT BE AS BAD THURSDAY. HOWEVER, IT WILL STILL BE AN ISSUE. && .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 331 AM EDT WED JUL 29 2015 WITH THE 500 MB LOW JUST NORTH OF JAMES BAY, WE GO BACK TO THE PATTERN THAT WE`VE HAD OVER N MICHIGAN THE LAST 2 YEARS WITH COOLER THAN NORMAL TEMPERATURES AND POSSIBLY SHOWERY CONDITIONS, BUT NOTHING APPRECIABLE, AT LEAST FOR THE TIME BEING. CIPS ANALOGS FALL RIGHT IN LINE WITH THE MEX NUMBERS AS WELL AS THE ECMWF IDEAS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY) ISSUED AT 650 AM EDT WED JUL 29 2015 OVERALL CONDITIONS WILL REMAIN VFR AT ALL NRN LWR MICHIGAN TAF SITES THRU WEDNESDAY NIGHT. A COLD FRONT WILL SWEEP THRU THE REGION TODAY. LIMITED MOISTURE AND ONLY WEAK INSTABILITY ALONG AND AHEAD OF THE FRONT WILL RESTRICT POPS TO ONLY CHANCE. EXPECT A BAND OF SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS WILL SLOWLY PUSH FROM WEST TO EAST THRU NRN LWR MICHIGAN THROUGHOUT THE DAY. WILL CONTINUE TO HANDLE WITH VCSH IN THE TAFS FOR NOW. SOUTH WINDS UNDER 10 KTS WILL SHIFT TO THE WEST IN THE WAKE OF THE FRONT AND WILL INCREASE TO 10 TO 15 KTS...WITH A FEW HIGHER GUSTS POSSIBLE. && .MARINE... ISSUED AT 1054 AM EDT WED JUL 29 2015 ...BECOMING BREEZY THROUGH THE AFTERNOON... A COLD FRONT IS CROSSING INTO NRN MICHIGAN LATE THIS MORNING WITH DEEP DRY AIR AND GUSTY WESTERLY WINDS MAKING THEIR WAY EAST ACROSS LAKE MICHIGAN. FEEL FAIRLY CONFIDENT IN THE DEVELOPMENT OF ADVISORY LEVEL WINDS DEVELOPING OVER MOST OF THE NEARSHORE WATERS THROUGH TONIGHT...AS SHALLOW COOLER AIR RESULTS IN NEAR NEUTRAL STABILITY OVER THE LAKES. COULD BE DEALING WITH SOME CONTINUED ADVISORY LEVEL GUSTS FOR LATER PERIODS...AS WINDS REMAIN WESTERLY. LOOKING FOR SOME SCATTERED SHOWERS AND PERHAPS SOME THUNDERSTORMS ALONG AND AHEAD OF THE COLD FRONT...FOR THE NE LOWER NEARSHORE WATERS FOR THE EARLY AND MID AFTERNOON. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR LHZ345>347. LM...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR LMZ323-341-342- 344>346. LS...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR LSZ322. && $$ UPDATE...SMD NEAR TERM...MLR SHORT TERM...JSL LONG TERM...JSL AVIATION...MLR MARINE...SMD
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1045 AM EDT WED JUL 29 2015 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 330 AM EDT WED JUL 29 2015 SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A COLD FRONT CROSSES THE REGION. GUSTY WESTERLY WINDS BEHIND THE FRONT WILL USHER IN MORE COMFORTABLE LESS HUMID AIR FOR THE REMAINDER OF THE WEEK ALTHOUGH HIGHS WILL REMAIN IN THE LOWER TO MID 80S. && .UPDATE... ISSUED AT 1044 AM EDT WED JUL 29 2015 DECREASED POPS A BIT BASED ON RADAR TRENDS. A WEAK COLD FRONT IS MOVING ACROSS LAKE MICHIGAN ATTM AND MAY KICK OFF A STORM OR TWO THIS AFTERNOON MAINLY ACROSS THE EASTERN CWA. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 ISOLATED SHOWERS HAVE DEVELOPED OVERNIGHT ON THE LEADING EDGE OF THE HIGHER PRECIPITABLE WATER AROUND TWO INCHES MOVING IN FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. SUSPECT COVERAGE OF SHOWERS WILL REMAIN RATHER LIMITED THIS MORNING ACROSS SW LWR MI AS MORE EXPANSIVE AREA OF CONVECTION IMPACTS IOWA AND ILLINOIS. OUR BEST PROSPECT FOR BETTER COVERAGE OF STORMS WILL BE THIS AFTERNOON EAST OF HIGHWAY 131 WHERE SB CAPES NEAR 1500 J/KG ARE PROGGED JUST AHEAD OF THE FRONT. RUC FCST SOUNDINGS EXHIBIT STEEP LOW LEVEL LAPSE RATES WITH SFC TO 3 KM VALUES AROUND 8.5C NEAR JXN. BASED ON THE HIGH PWAT VALUES OF UP TO 2.25 INCHES WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF SOME TORRENTIAL RAINFALL AND POSSIBLY A LOCALIZED WET MICROBURST DAMAGING WIND EVENT. CONVECTION ENDS FROM WEST TO EAST 18Z-22Z WITH THE PASSAGE OF THE FRONT THEN DECREASING CLOUDS AND FALLING SFC DEW PTS EXPECTED. BREEZY CONDITIONS LIKELY THURSDAY ONCE DEEPER MIXING COMMENCES. SOME GUSTS TO 30 MPH WILL BE POSSIBLE IN THE AFTERNOON. HAVE KEPT FRIDAY DRY FOR NOW ALTHOUGH SOME SMALL POPS MAY NEED TO BE ADDED IN LATER FCSTS AS NEXT WEAK SFC FRONT/TROUGH DROPS SOUTH. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 THERE HAS NOT BEEN MUCH CHANGE OVER THE THE PAST FEW DAYS WITH REGARD TO THE EXPECTED PATTERN. WE CONTINUE TO EXPECT LITTLE TO NO RAIN THROUGH SAT...BEFORE AN UNSETTLED WEATHER PATTERN TAKES SHAPE LATER THIS WEEKEND AND INTO NEXT WEEK. WE HAVE CONTINUED WITH A DRY FCST FOR THE FRI NIGHT AND SAT TIME FRAME FOR NOW. WE WILL SEE WHAT IS LEFT OF THE WEAKENING COLD FRONT TRYING TO MOVE THROUGH ON FRI SLIP SE OF THE AREA FRI EVENING. WE CAN NOT RULE OUT A SHOWER DEVELOPING NEAR THIS FRONT...HOWEVER THE CHC IS LOW ENOUGH TO LEAVE OUT OF THE FCST FOR THE TIME BEING. A LACK OF MOISTURE WITH THE FRI FRONT WILL ONLY DIMINISH BY SAT AS THE FRONT MOVES OUT. THERE IS NOT REALLY SIGNIFICANTLY COOLER AIR BEHIND THIS...SO WE CONTINUE TO EXPECT HIGHS AROUND 80. THE CHCS OF RAIN DOES GO UP ON SUN...AND WILL CONTINUE THROUGH THE END OF THE PERIOD ON TUE. THE AREA WILL BE UNDER THE INFLUENCE OF BROAD LONG WAVE TROUGHING CENTERED WELL NORTH IN CANADA. WE WILL SEE THE JET CORE DROP A LITTLE FURTHER SOUTH WITH A TRAIN OF SHORT WAVES HELPING THIS CAUSE. BEING CLOSER TO THE JET...WE WILL HAVE MORE OF AN OPPORTUNITY FOR THE SHORT WAVES TO DIRECTLY IMPACT THE AREA. WE WILL ALSO SEE THE LOW LEVEL FLOW BECOME A LITTLE MORE FAVORABLE TO BRING SUFFICIENT MOISTURE TO THE AREA FOR RAIN. EXACT TIMING OF THE SHORT WAVES WILL BE PROBLEMATIC AS IS USUAL IN A PATTERN LIKE THIS. TEMPERATURES DO NOT LOOK TO BE TOO BAD IN THIS PATTERN. THE UNSEASONABLY COOL AIR WILL REMAIN JUST NORTH OF THE STATE...NORTH OF THE JET CORE. WE WILL SEE AVERAGE TO JUST SLIGHTLY BELOW AVERAGE TEMPS DURING THIS PERIOD FOR OUR AREA. THIS EQUATES TO HIGHS GENERALLY AROUND 80 AND LOWS AROUND 60. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 745 AM EDT WED JUL 29 2015 IT SHOULD REMAIN VFR FOR THE MOST PART TODAY DESPITE A COLD FRONT WITH SCATTERED SHOWERS MOVING THROUGH. HOWEVER SOME BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE WHERE/WHEN THE SHOWERS ARE OCCURRING. THE BEST CHANCE OF TSTMS WILL BE FROM ABOUT 17Z TO 22Z EAST OF A GRR-AZO LINE. SKIES WILL CLEAR FROM WEST TO EAST AFTER 18Z WITH WINDS INCREASING OUT OF THE WEST TO 12-22KTS. CLR SKIES AND WEST WINDS OF 5-10 KTS ARE EXPECTED AFTER 00Z TONIGHT. && .MARINE... ISSUED AT 330 AM EDT WED JUL 29 2015 CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA LATE TONIGHT AND EARLY THURSDAY DUE TO STRONG WESTERLY FLOW BEHIND THE COLD FRONT. THIS WILL NEED TO BE MONITORED. THIS SITUATION COULD ALSO SUPPORT BEACH HAZARD STATEMENTS ESPECIALLY CONSIDERING THE CURRENT WARM WATER TEMPERATURES AND OVERALL ATTRACTIVE BEACH CONDITIONS SUPPORTIVE OF A HIGH BEACH POPULATION. && .HYDROLOGY... ISSUED AT 1250 PM EDT TUE JUL 28 2015 RIVER LEVELS ARE FALLING AND WELL BELOW BANKFULL. WITH UNDER A HALF INCH OF PRECIPITATION EXPECTED INTO NEXT WEEK... THESE CONDITIONS SHOULD CONTINUE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...04 SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...NJJ AVIATION...MEADE HYDROLOGY...63 MARINE...MEADE
AREA FORECAST DISCUSSION
NWS GAYLORD MI
806 AM EDT WED JUL 29 2015 .UPDATE... ISSUED AT 805 AM EDT WED JUL 29 2015 IMPACT WEATHER: SCATTERED THUNDERSTORMS DEVELOPING THROUGH THE DAY. SYNOPTIC PATTERN AND OBSERVATIONS: MORNING ANALYSIS...LOW PRESSURE WAS PUSHING THROUGH WESTERN ONTARIO WHILE DRAGGING A COLD FRONT ACROSS CENTRAL LAKE SUPERIOR...EASTERN WISCONSIN AND ILLINOIS. SFC OBS...UPPER AIR AND HI-RES THETA-E ANALYSIS SHOWING A WARM FRONT OUT AHEAD OF THE COLD FRONT...DRAPED FROM CENTRAL LAKE MICHIGAN TO NRN INDIANA. THIS LEAVES A RATHER NARROW "WARM SECTOR" THAT WAS PROGRESSING INTO THE REGION...WIDEST THOUGH ACROSS THE SRN CWA. SCATTERED SHOWERS WERE SEEN ACROSS SRN WI AND SRN LAKE MICHIGAN...IN THE WARM SECTOR...FORCED BY SOME UPPER DIVERGENCE IN RIGHT ENTRANCE REGION OF 100+KT JET OVER MN. ALSO IN PLAY...WEAK VORTICITY MAXIMA IN THE SRN END OF THE BETTER SW FLOW ALOFT ACROSS THIS REGION. THERE WAS NOTHING ON THE FRONT NORTH OF THIS FORCING. LAPSE RATES ALOFT WERE NOT TOO GOOD AT 5.0 C/KM AND THE RESULTING CAPE WAS MINIMAL TO NONE AT THE MOMENT. WIND FIELDS ARE ALSO PATHETIC RIGHT NOW...BUT STRONGER WINDS AND RESULTANT 0-6KM BULK SHEAR OF 25-30KTS WAS ACROSS SRN WISCONSIN...GETTING A LITTLE BETTER. THROUGH THE DAY...AFOREMENTIONED WARM/COLD FRONTS LIFT INTO NRN MICHIGAN..WITH WIDEST WARM SECTOR...BETTER PVA/VORTICITY AND POSSIBLE WEAK UPPER DIVERGENCE (ALTHOUGH WE ARE REALLY IN A POOR POSITION OF THE UPPER JET) TO SPREAD ACROSS THE SRN CWA. LAPSE RATES IMPROVE LITTLE...MAXING OUT AT 5.5 C/KM...WHILE THE FRONT MAKES IT TO NE LOWER EARLY TO MID AFTERNOON. THE SITUATION IS NOW PLAYING OUT FOR WARMING/DESTABILIZATION THROUGH THE DAY TO DEVELOP SHOWERS AND SCATTERED THUNDERSTORMS ALONG THE FRONT. THE MOST INSTABILITY WE SEEM TO BE ABLE TO GENERATE WILL BE SOMEWHERE BETWEEN 200 J/KG IN EASTERN UPPER...TO AS MUCH AS 700-800 J/KG SOUTH. THIS IS MORE THAN LIKELY NOT GOING TO RESULT IN ANY CHANCE OF ORGANIZED STORMS/SEVERE WEATHER....EVEN WITH INCREASING WINDS/0-6KM BULK SHEAR THROUGH THE DAY. DO BELIEVE THAT SHOWERS WILL SLOWLY INCREASE THROUGH THE MORNING WITH THE CHANCE OF THUNDERSTORMS INCREASING ALONG/AHEAD OF THE FRONT THROUGH THE LATE MORNING/EARLY AFTERNOON. && .NEAR TERM...(TODAY THROUGH TONIGHT) ISSUED AT 331 AM EDT WED JUL 29 2015 PERSISTENT HIGH PRESSURE HAS SHIFTED EAST OF MICHIGAN EARLY THIS MORNING AS A COLD FRONT APPROACHES FROM THE WEST. MID AND HIGH CLOUDS HAVE BEGUN TO INCREASE ALONG THE NE PERIPHERY OF THE CONVECTIVE CLOUD SHIELD GENERATED FROM THE MCS CURRENTLY IMPACTING IOWA...NRN MISSOURI AND NRN ILLINOIS. THIS CONVECTION IS FUELED BY A STRONG INSTABILITY AXIS (CAPES OF AROUND 3000 JOULES) AND 850 MB THETA E RIDGING PUNCHING THRU THE MISSISSIPPI VALLEY ATTM. FURTHER NORTH...OUR UPSTREAM RADARS SHOW A FEW SHOWERS AND EMBEDDED WEAK STORMS TRYING TO DEVELOP JUST EAST OF THE ARROWHEAD OF MINNESOTA OVER WRN LAKE SUPERIOR JUST AHEAD OF THE APPROACHING COLD FRONT. CONVECTION IS STRUGGLING DUE TO WEAK INSTABILITY (500 JOULES OR LESS) AND VERY LIMITED MOISTURE. LATEST NAM12...RAP13 AND HRRR ALL SUGGEST THE FOCUS FOR MEANINGFUL CONVECTIVE DEVELOPMENT WILL STAY SOUTH OF OUR CWA THRU TODAY WHERE STRONGER INSTABILITY AND MUCH BETTER MOISTURE WILL RESIDE. NORTHERN MICHIGAN IS ONCE AGAIN LOOKING AT THE PROSPECT THAT THE MAJORITY OF OUR CWA MAY MISS OUT ON AN OPPORTUNITY FOR SOME MUCH NEEDED RAIN TODAY. STILL...CHANCE POPS WILL REMAIN IN ORDER THRU THE DAY...WITH THE EXPECTATION THAT A NARROW LINE OF SCATTERED SHOWERS WITH SOME EMBEDDED THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD FRONT. WILL MAKE SOME MINOR TIMING ADJUSTMENTS TO THIS BAND OF PRECIP AS IT SLOWLY MOVES THRU OUR CWA TODAY...BUT WILL CERTAINLY KEEP POPS IN THE CHANCE CATEGORY. NO REAL CHANCE FOR STRONG TO SEVERE STORMS GIVEN LIMITED INSTABILITY AND MOISTURE AND UNIMPRESSIVE WIND FIELDS AHEAD OF THE FRONT. EXPECT ANOTHER VERY WARM DAY FOR NORTHERN MICHIGAN...BUT NOT AS WARM AS IT HAS BEEN THE PAST FEW DAYS. HIGH TEMPS WILL WARM WELL INTO THE 80S...BUT SHOULD REFRAIN FROM REACHING INTO THE 90S. OVERNIGHT LOWS WILL COOL BACK INTO THE 60S. && .SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT) ISSUED AT 331 AM EDT WED JUL 29 2015 (7/30)THURSDAY...WITH THE FRONTAL PASSAGE TODAY, THE TEMPERATURES FALL BACK TO NORMAL FOR THURSDAY. THERE ARE TWO CONCERNS FOR THE DAY AND INTO THE NIGHT. 1) CLOUD COVER, ESPECIALLY NEAR ANJ. THE 850 MB RH IS AROUND 90%, AND WITH THE 850 MB TEMPERATURES NEAR +10C, NEAR E UPPER, IT COULD BE CLOUDIER. WHICH LEADS TO 2) TEMPERATURES COULD END UP COOLER IF THERE ARE MORE CLOUDS IN E UPPER AND EVEN PARTS OF THE N LOWER IF THE CLOUDS MAKE IT DOWN FAR ENOUGH SOUTH, BUT THAT SEEMS ONLY TO ABOUT M-32 AT THE MOST. SOUTH OF M-32, HOWEVER, THERE IS A DIFFERENT CONCERN, FIRE WEATHER. WILL EXPECT THAT THE HIGH TEMPERATURES WILL REMAIN OVER 75F (CIPS ANALOG GUIDANCE SHOWS 70% AT THE TEMPERATURES>75F). WINDS WILL BE AROUND 15MPH AT THE 20FT LEVEL (SUSTAINED), WITH THE RH AROUND 30- 35%. AND WITH THE EXTENDED DRY PERIOD, WILL BE GOING WITH THE ELEVATED FIRE DANGER. (7/31)FRIDAY...THE DISCUSSION FOR THURSDAY COULD VERY WELL FIT FOR FRIDAY AS WELL, EXCEPT THAT THERE IS A WEAK SFC LOW TRYING TO MOVE INTO THE REGION AS THE 500 MB LOW SINKS A LITTLE MORE SOUTH AND BEGINS TO COOL THINGS DOWN A BIT. AGAIN THE COOLEST, PROBABLY CLOUDIEST AREA WILL BE NORTH OF M-32, WITH THE SOO DROPPING INTO THE LOWER 70S FOR HIGHS POSSIBLY. LOOKS LIKE WE ARE STILL AROUND 80S SOUTH OF M-32, AND WINDS WILL BE AGAIN BE CLOSE TO 15 MPH AT 20FT, SO THERE IS AN ELEVATED FIRE DANGER RISK, ALTHOUGH THE RH MAY NOT BE AS BAD THURSDAY. HOWEVER, IT WILL STILL BE AN ISSUE. && .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 331 AM EDT WED JUL 29 2015 WITH THE 500 MB LOW JUST NORTH OF JAMES BAY, WE GO BACK TO THE PATTERN THAT WE`VE HAD OVER N MICHIGAN THE LAST 2 YEARS WITH COOLER THAN NORMAL TEMPERATURES AND POSSIBLY SHOWERY CONDITIONS, BUT NOTHING APPRECIABLE, AT LEAST FOR THE TIME BEING. CIPS ANALOGS FALL RIGHT IN LINE WITH THE MEX NUMBERS AS WELL AS THE ECMWF IDEAS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY) ISSUED AT 650 AM EDT WED JUL 29 2015 OVERALL CONDITIONS WILL REMAIN VFR AT ALL NRN LWR MICHIGAN TAF SITES THRU WEDNESDAY NIGHT. A COLD FRONT WILL SWEEP THRU THE REGION TODAY. LIMITED MOISTURE AND ONLY WEAK INSTABILITY ALONG AND AHEAD OF THE FRONT WILL RESTRICT POPS TO ONLY CHANCE. EXPECT A BAND OF SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS WILL SLOWLY PUSH FROM WEST TO EAST THRU NRN LWR MICHIGAN THROUGHOUT THE DAY. WILL CONTINUE TO HANDLE WITH VCSH IN THE TAFS FOR NOW. SOUTH WINDS UNDER 10 KTS WILL SHIFT TO THE WEST IN THE WAKE OF THE FRONT AND WILL INCREASE TO 10 TO 15 KTS...WITH A FEW HIGHER GUSTS POSSIBLE. && .MARINE... ISSUED AT 331 AM EDT WED JUL 29 2015 CHANCES OF SHOWERS AND STORMS WILL INCREASE FROM WEST TO EAST TODAY AS A COLD FRONT SWINGS THROUGH NORTHERN MICHIGAN. WINDS AND WAVES WILL APPROACH SCA CRITERIA THIS AFTERNOON AND THIS EVENING AS WINDS SHIFT TO THE WEST AND STRENGTHEN BEHIND THE COLD FRONT. AT THIS POINT...EXPECT CONDITIONS WILL FALL JUST SHORT OF CRITERIA. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ UPDATE...SMD NEAR TERM...MLR SHORT TERM...JSL LONG TERM...JSL AVIATION...MLR MARINE...MLR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
746 AM EDT WED JUL 29 2015 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 330 AM EDT WED JUL 29 2015 SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A COLD FRONT CROSSES THE REGION. GUSTY WESTERLY WINDS BEHIND THE FRONT WILL USHER IN MORE COMFORTABLE LESS HUMID AIR FOR THE REMAINDER OF THE WEEK ALTHOUGH HIGHS WILL REMAIN IN THE LOWER TO MID 80S. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 ISOLATED SHOWERS HAVE DEVELOPED OVERNIGHT ON THE LEADING EDGE OF THE HIGHER PRECIPITABLE WATER AROUND TWO INCHES MOVING IN FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. SUSPECT COVERAGE OF SHOWERS WILL REMAIN RATHER LIMITED THIS MORNING ACROSS SW LWR MI AS MORE EXPANSIVE AREA OF CONVECTION IMPACTS IOWA AND ILLINOIS. OUR BEST PROSPECT FOR BETTER COVERAGE OF STORMS WILL BE THIS AFTERNOON EAST OF HIGHWAY 131 WHERE SB CAPES NEAR 1500 J/KG ARE PROGGED JUST AHEAD OF THE FRONT. RUC FCST SOUNDINGS EXHIBIT STEEP LOW LEVEL LAPSE RATES WITH SFC TO 3 KM VALUES AROUND 8.5C NEAR JXN. BASED ON THE HIGH PWAT VALUES OF UP TO 2.25 INCHES WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF SOME TORRENTIAL RAINFALL AND POSSIBLY A LOCALIZED WET MICROBURST DAMAGING WIND EVENT. CONVECTION ENDS FROM WEST TO EAST 18Z-22Z WITH THE PASSAGE OF THE FRONT THEN DECREASING CLOUDS AND FALLING SFC DEW PTS EXPECTED. BREEZY CONDITIONS LIKELY THURSDAY ONCE DEEPER MIXING COMMENCES. SOME GUSTS TO 30 MPH WILL BE POSSIBLE IN THE AFTERNOON. HAVE KEPT FRIDAY DRY FOR NOW ALTHOUGH SOME SMALL POPS MAY NEED TO BE ADDED IN LATER FCSTS AS NEXT WEAK SFC FRONT/TROUGH DROPS SOUTH. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 THERE HAS NOT BEEN MUCH CHANGE OVER THE THE PAST FEW DAYS WITH REGARD TO THE EXPECTED PATTERN. WE CONTINUE TO EXPECT LITTLE TO NO RAIN THROUGH SAT...BEFORE AN UNSETTLED WEATHER PATTERN TAKES SHAPE LATER THIS WEEKEND AND INTO NEXT WEEK. WE HAVE CONTINUED WITH A DRY FCST FOR THE FRI NIGHT AND SAT TIME FRAME FOR NOW. WE WILL SEE WHAT IS LEFT OF THE WEAKENING COLD FRONT TRYING TO MOVE THROUGH ON FRI SLIP SE OF THE AREA FRI EVENING. WE CAN NOT RULE OUT A SHOWER DEVELOPING NEAR THIS FRONT...HOWEVER THE CHC IS LOW ENOUGH TO LEAVE OUT OF THE FCST FOR THE TIME BEING. A LACK OF MOISTURE WITH THE FRI FRONT WILL ONLY DIMINISH BY SAT AS THE FRONT MOVES OUT. THERE IS NOT REALLY SIGNIFICANTLY COOLER AIR BEHIND THIS...SO WE CONTINUE TO EXPECT HIGHS AROUND 80. THE CHCS OF RAIN DOES GO UP ON SUN...AND WILL CONTINUE THROUGH THE END OF THE PERIOD ON TUE. THE AREA WILL BE UNDER THE INFLUENCE OF BROAD LONG WAVE TROUGHING CENTERED WELL NORTH IN CANADA. WE WILL SEE THE JET CORE DROP A LITTLE FURTHER SOUTH WITH A TRAIN OF SHORT WAVES HELPING THIS CAUSE. BEING CLOSER TO THE JET...WE WILL HAVE MORE OF AN OPPORTUNITY FOR THE SHORT WAVES TO DIRECTLY IMPACT THE AREA. WE WILL ALSO SEE THE LOW LEVEL FLOW BECOME A LITTLE MORE FAVORABLE TO BRING SUFFICIENT MOISTURE TO THE AREA FOR RAIN. EXACT TIMING OF THE SHORT WAVES WILL BE PROBLEMATIC AS IS USUAL IN A PATTERN LIKE THIS. TEMPERATURES DO NOT LOOK TO BE TOO BAD IN THIS PATTERN. THE UNSEASONABLY COOL AIR WILL REMAIN JUST NORTH OF THE STATE...NORTH OF THE JET CORE. WE WILL SEE AVERAGE TO JUST SLIGHTLY BELOW AVERAGE TEMPS DURING THIS PERIOD FOR OUR AREA. THIS EQUATES TO HIGHS GENERALLY AROUND 80 AND LOWS AROUND 60. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 ISOLATED SHOWERS HAVE DEVELOPED OVERNIGHT ON THE LEADING EDGE OF THE HIGHER PRECIPITABLE WATER AROUND TWO INCHES MOVING IN FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. SUSPECT COVERAGE OF SHOWERS WILL REMAIN RATHER LIMITED THIS MORNING ACROSS SW LWR MI AS MORE EXPANSIVE AREA OF CONVECTION IMPACTS IOWA AND ILLINOIS. OUR BEST PROSPECTS FOR BETTER COVERAGE OF STORMS WILL BE THIS AFTERNOON EAST OF HIGHWAY 131 WHERE SB CAPES NEAR 1500 J/KG ARE PROGGED JUST AHEAD OF THE FRONT. RUC FCST SNDGS EXHIBIT STEEP LOW LEVEL LAPSE RATES WITH SFC TO 3 KM AROUND 8.5C NEAR JXN. BASED ON THE HIGH PWAT VALUES OF UP TO 2.25 INCHES WE WILL HAVE TO WATCH OF THE POSSIBILITY OF SOME TORRENTIAL RAINFALL AND POSSIBLY A LOCALIZED WET MICROBURST DAMAGING WIND EVENT. CONVECTION ENDS FROM WEST TO EAST 18Z-22Z WITH THE PASSAGE OF THE FRONT THEN DECREASING CLOUDS AND FALLING SFC DEW PTS EXPECTED. BREEZY CONDITIONS EXPECTED THURSDAY ONCE DEEPER MIXING COMMENCES. SOME GUSTS TO 30 MPH WILL BE POSSIBLE IN THE AFTERNOON. HAVE KEPT FRIDAY DRY FOR NOW ALTHOUGH SOME SMALL POPS MAY NEED TO BE ADDED IN LATER FCSTS AS NEXT WEAK FRONT/TROUGH DROPS SOUTH. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 THERE HAS NOT BEEN MUCH CHANGE OVER THE THE PAST FEW DAYS WITH REGARD TO THE EXPECTED PATTERN. WE CONTINUE TO EXPECT LITTLE TO NO RAIN THROUGH SAT...BEFORE AN UNSETTLED WEATHER PATTERN TAKES SHAPE LATER THIS WEEKEND AND INTO NEXT WEEK. WE HAVE CONTINUED WITH A DRY FCST FOR THE FRI NIGHT AND SAT TIME FRAME FOR NOW. WE WILL SEE WHAT IS LEFT OF THE WEAKENING COLD FRONT TRYING TO MOVE THROUGH ON FRI SLIP SE OF THE AREA FRI EVENING. WE CAN NOT RULE OUT A SHOWER DEVELOPING NEAR THIS FRONT...HOWEVER THE CHC IS LOW ENOUGH TO LEAVE OUT OF THE FCST FOR THE TIME BEING. A LACK OF MOISTURE WITH THE FRI FRONT WILL ONLY DIMINISH BY SAT AS THE FRONT MOVES OUT. THERE IS NOT REALLY SIGNIFICANTLY COOLER AIR BEHIND THIS...SO WE CONTINUE TO EXPECT HIGHS AROUND 80. THE CHCS OF RAIN DOES GO UP ON SUN...AND WILL CONTINUE THROUGH THE END OF THE PERIOD ON TUE. THE AREA WILL BE UNDER THE INFLUENCE OF BROAD LONG WAVE TROUGHING CENTERED WELL NORTH IN CANADA. WE WILL SEE THE JET CORE DROP A LITTLE FURTHER SOUTH WITH A TRAIN OF SHORT WAVES HELPING THIS CAUSE. BEING CLOSER TO THE JET...WE WILL HAVE MORE OF AN OPPORTUNITY FOR THE SHORT WAVES TO DIRECTLY IMPACT THE AREA. WE WILL ALSO SEE THE LOW LEVEL FLOW BECOME A LITTLE MORE FAVORABLE TO BRING SUFFICIENT MOISTURE TO THE AREA FOR RAIN. EXACT TIMING OF THE SHORT WAVES WILL BE PROBLEMATIC AS IS USUAL IN A PATTERN LIKE THIS. TEMPERATURES DO NOT LOOK TO BE TOO BAD IN THIS PATTERN. THE UNSEASONABLY COOL AIR WILL REMAIN JUST NORTH OF THE STATE...NORTH OF THE JET CORE. WE WILL SEE AVERAGE TO JUST SLIGHTLY BELOW AVERAGE TEMPS DURING THIS PERIOD FOR OUR AREA. THIS EQUATES TO HIGHS GENERALLY AROUND 80 AND LOWS AROUND 60. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 745 AM EDT WED JUL 29 2015 IT SHOULD REMAIN VFR FOR THE MOST PART TODAY DESPITE A COLD FRONT WITH SCATTERED SHOWERS MOVING THROUGH. HOWEVER SOME BRIEF PERIODS OF MVFR CONDITIONS ARE POSSIBLE WHERE/WHEN THE SHOWERS ARE OCCURRING. THE BEST CHANCE OF TSTMS WILL BE FROM ABOUT 17Z TO 22Z EAST OF A GRR-AZO LINE. SKIES WILL CLEAR FROM WEST TO EAST AFTER 18Z WITH WINDS INCREASING OUT OF THE WEST TO 12-22KTS. CLR SKIES AND WEST WINDS OF 5-10 KTS ARE EXPECTED AFTER 00Z TONIGHT. && .MARINE... ISSUED AT 330 AM EDT WED JUL 29 2015 CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA LATE TONIGHT AND EARLY THURSDAY DUE TO STRONG WESTERLY FLOW BEHIND THE COLD FRONT. THIS WILL NEED TO BE MONITORED. THIS SITUATION COULD ALSO SUPPORT BEACH HAZARD STATEMENTS ESPECIALLY CONSIDERING THE CURRENT WARM WATER TEMPERATURES AND OVERALL ATTRACTIVE BEACH CONDITIONS SUPPORTIVE OF A HIGH BEACH POPULATION. && .HYDROLOGY... ISSUED AT 1250 PM EDT TUE JUL 28 2015 RIVER LEVELS ARE FALLING AND WELL BELOW BANKFULL. WITH UNDER A HALF INCH OF PRECIPITATION EXPECTED INTO NEXT WEEK... THESE CONDITIONS SHOULD CONTINUE. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...NJJ AVIATION...MEADE HYDROLOGY...63 MARINE...MEADE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 AM EDT WED JUL 29 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 418 AM EDT WED JUL 29 2015 FAIRLY IMPRESSIVE SURFACE AND UPPER LOW FOR LATE JULY IS LOCATED JUST TO THE SOUTH OF LAKE WINNIPEG EARLY THIS MORNING...AND IT IS KEEPING MUCH OF ITS ENERGY NEAR THE LOW IN MANITOBA. THIS HAS LED TO A FAIRLY UNEVENTFUL PASSAGE OF THE COLD FRONT DUE TO THE LACK OF ANY UPPER LEVEL SUPPORT/SHORTWAVES MOVING THROUGH THE AREA AND THE MID- LEVEL DRY AIR AND CAPPING SEEN ON RAP ANALYSIS SOUNDINGS. THERE WAS A THUNDERSTORM THAT MOVED NORTHEAST OUT OF NORTHWEST WISCONSIN EARLIER IN THE NIGHT BUT DISSIPATED OVER WESTERN LAKE SUPERIOR. HAVE SEEN SOME LIGHT SHOWER DEVELOPMENT OVER THE WESTERN U.P. OVER THE LAST 1-2HRS AND THEY ARE MOVING NORTHEAST WHILE THE FRONT SHIFTS THEM TO THE EAST. THERE HASN/T BEEN ANY LIGHTNING NOTED WITH THEM THUS FAR...LARGELY DUE TO THEM STRUGGLING TO GET ABOVE THE FREEZING LEVEL (HAVE PEAKED AROUND 15KFT). STILL THINK SOME THUNDER IS POSSIBLE AS THEY ALIGN WITH A THIN AREA OF 500 J/KG OF MUCAPE AHEAD OF THE FRONT AS SEEN ON THE SPC MESOSCALE ANALYSIS PAGE. THE COLD FRONT WILL CONTINUE TO THE EAST THIS MORNING AND EXIT THE AREA BY NOON. WILL CONTINUE TO SHOW SLIGHT CHANCE POPS RIGHT ALONG THE FRONT AS IT MOVES EAST THIS MORNING...BUT DON/T EXPECT ANYTHING MORE THAN AN ISOLATED SHOWER/THUNDERSTORM. HAVE SEEN A FAIRLY SIGNIFICANT DROP IN DEWPOINTS BEHIND THE FRONT...AS KIWD WENT FROM A 72 DEGREE DEWPOINT AT 535Z AND QUICKLY DROPPED TO 64 AT 615Z AND IS NOW AT 57 AT 735Z. BEHIND THE FRONT...THE DRY SLOT SEEN ON WATER VAPOR IMAGERY WILL MOVE THROUGH THE AREA AND LEAD TO AN AREA OF MOSTLY SUNNY START TO THE DAY OVER THE WEST. DO EXPECT THE AREA OF CLOUDS IN NORTHEAST ND AND NORTHWEST MN TO MOVE EAST INTO THE WESTERN CWA THIS AFTERNOON AND BE AIDED BY DIURNAL HEATING TO PRODUCE DIURNAL CU ON THE LEADING EDGE AND AHEAD OF THE CLOUDS INTO THE CENTRAL U.P. OVER THE EAST...AFTER A CLOUDY START TO THE DAY...EXPECT A PERIOD OF MOSTLY SUNNY SKIES AND THEN SOME DIURNAL CU IN AFTERNOON AND LINGERING INTO THE EVENING. HIGHS TODAY WILL BE IN THE UPPER 70S OVER THE WEST AND THE LOW-MID 80S OVER THE CENTRAL AND EAST. THE MAIN HAZARD BEHIND THE FRONT WILL BE THE GUSTY WEST-SOUTHWEST WINDS. THESE WINDS WILL BE AIDED BY THE TIGHT PRESSURE GRADIENT OVER THE NORTHWEST HALF OF THE CWA AND LARGELY OVER NORTHWESTERN LAKE SUPERIOR. HAVE ALREADY SEEN GUSTS TO 20-25KTS IMMEDIATELY BEHIND THE FRONT EARLIER IN THE NIGHT AND CLOSER TO THE LOW WINDS HAVE BEEN GUSTING TO 30-35KTS IN NORTHWEST MINNESOTA. THE AMPLE SUNSHINE THIS MORNING WILL HELP TO MIX INTO THE 25-40KT WINDS AROUND 925MB TO THE SURFACE...WITH THE STRONGEST WINDS OVER THE KEWEENAW PENINSULA. IN THAT AREA...WOULD EXPECT GUSTS TO AROUND 35KTS BY MID AFTERNOON AND THERE COULD BE A BRIEF PERIOD OF GUSTS TO 40KTS BY EARLY EVENING. DON/T THINK THERE WILL BE A LONG ENOUGH PERIOD FOR A WIND ADVISORY FOR THE KEWEENAW PENINSULA (NEED 39KTS)...SO WILL ISSUE AN SPS FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES TO HIGHLIGHT THE WINDY CONDITIONS FOR TODAY. THE REST OF THE U.P. WILL SEE WIND GUSTS OF 20- 30KTS...HIGHEST OVER THE WEST. WITH THE MUCH DRIER AIR MOVING INTO THE AREA...THINK DEWPOINTS WILL MIX OUT INTO THE UPPER 40S TO AROUND 50 OVER THE WEST/CENTRAL TODAY. WHILE TEMPERATURES WILL BE COOLER THAN YESTERDAY...RH VALUES WILL STILL FALL INTO THE 30S. THAT WILL LEAD TO AN ELEVATED RISK OF WILDFIRES ACROSS MUCH OF THE U.P. TODAY. SINCE THE RH VALUES WILL BE ABOVE RED FLAG CRITERIA...THIS SITUATION WOULD FALL UNDER AN RFD PRODUCT DUE TO THE FREQUENT GUSTS OVER 25 MPH. SINCE COORDINATION NEEDS TO BE DONE WITH FIRE WX USERS BEFORE ISSUANCE...WILL PASS ALONG TO DAY SHIFT TO COORDINATE POTENTIAL ISSUANCE. A SECONDARY TROUGH MOVES EAST ACROSS THE AREA TONIGHT. SOME CLOUDS ASSOCIATED WITH IT...LARGELY OVER LAKE SUPERIOR...BUT NOT EXPECTING ANY RAIN. THERE WILL STILL BE STRONG WINDS JUST ABOVE THE SURFACE AGAIN TONIGHT...WHICH WILL HELP TO KEEP THE WINDS FROM DECOUPLING. HAVE KEPT UP GUSTS OVER THE KEWEENAW PENINSULA (TO 20-30KTS) ...ESPECIALLY FOR THE EXPOSED LOCATIONS. OTHERWISE...THE REST OF THE AREA WILL SEE WINDS TURNING WESTERLY WITH GUSTS TO 10-20KTS (HIGHEST NORTH). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 455 AM EDT WED JUL 29 2015 THE OVERALL PATTERN AFFECTING THE AREA WILL NOT CHANGE MUCH THROUGH THE LONG TERM AS PERSISTENT CLOSED LOW NEAR HUDSON BAY WILL KEEP A BROAD TROUGH ENTRENCHED OVER MUCH OF ERN CANADA AND A BROAD RIDGE IS ANCHORED OVER THE WRN CONUS. BETWEEN THESE LARGE SCALE FEATURES A NW FLOW WILL DOMINATE THE GREAT LAKES REGION AS A SERIES OF MAINLY WEAK SHORTWAVES PASSING THRU BRING CHCS FOR PERIODIC LIGHT SHOWERS. TIMING OF THESE WEAK SHORTWAVES WILL LIKELY BE POORLY RESOLVED BY MODELS WHICH WILL MAKE FOR A TRICKY FCST IN THE LONG TERM. IT LOOKS LIKE TEMPERATURES WILL BE NEAR NORMAL THROUGH THE WEEKEND AND THEN TREND BELOW NORMAL TOWARD THE BEGINNING HALF OF NEXT WEEK AS A MID- LVL TROUGH BEGINS TO AMPLIFY INTO THE UPPER GREAT LAKES REGION. THU THROUGH FRI...MOST OF MODELS SHOW A WEAK SHORTWAVE MOVING THROUGH THE AREA TOWARD THU EVENING WITH ANOTHER WEAK SHORTWAVE MOVING THROUGH DURING THE DAY ON FRI. WITH SEVERAL OF THE MODELS SHOWING A FEW HUNDRED J/KG OF MLCAPE EACH DAY MAINLY DURING THE AFTERNOON/EVENING HRS WILL PROBABLY NEED TO MAINTAIN SLIGHT CHC POPS EACH DAY FOR ISOLD SHRA/TSRA. WITH LIMITED MOISTURE IN NW FLOW EXPECT ANY PCPN FROM ISOLD CONVECTION TO BE FAIRLY LIGHT. FRI NIGHT AND SAT...ANOTHER SHORTWAVE MOVING THROUGH DURING THIS TIME WILL WARRANT HAVING SLIGHT CHC POPS OVER MAINLY THE NW AND NE CWA INCLUDING LAKE SUPERIOR. TEMPERATURES THU THROUGH SAT WILL BE CLOSER TO NORMAL WITH HIGHS IN THE 70S TO LOWER 80S AND LOWS IN THE 50S TO LOWER 60S. MODELS HAVE TRENDED FARTHER NORTH WITH MORE SIGNIFICANT SHORTWAVE DUE TO MOVE IN SAT NIGHT INTO SUN SO HAVE BACKED OFF TO ONLY SLIGHT CHANCE POPS FOR THAT TIME FRAME. BEST LIFT WITH SHORTWAVE STAYS NORTH AND BETTER INSTABILITY AS INDICATED BY MODELS IS FARTHER SOUTH. TIMING OF SHORTWAVE AND ASSOC COLD FRONT FOR EARLY NEXT WEEK DIFFERS BTWN THE 00Z GFS AND 00Z ECMWF. THE ECMWF IS QUICKER BRINGING SYSTEM THROUGH SUN NIGHT INTO MON WHILE THE GFS DOESN/T BRING SYSTEM THRU UNTIL LATE MON INTO MON NIGHT. THIS SYSTEM MAY HAVE A BETTER CHC OF BRINGING MORE WIDESPREAD...ALTHOUGH LIGHT PCPN...BUT GIVEN UNCERTAINTY IN TIMING AT THIS POINT DON/T HAVE ANYTHING MORE THAN LOW CHC POPS. MODELS ADVERTISE TEMPS COOLING BELOW NORMAL TEMPS BEHIND THE FRONTAL SYSTEM ESPECIALLY BY TUE. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 717 AM EDT WED JUL 29 2015 A COLD FRONT HAS PASSED THROUGH ALL THREE TAF SITES EARLY THIS MORNING. GUSTY WEST-SOUTHWEST WINDS ARE EXPECTED AT ALL THREE SITES TODAY...WITH THE HIGHEST GUSTS (TO AROUND 35KTS) EXPECTED AT KCMX. THE WINDS WILL DIMINISH SOME AT ALL THREE SITES TONIGHT...BUT STILL EXPECT GUSTS TO 25KTS AT KCMX. AS FOR CLOUDS...CLEARING THIS MORNING WILL GIVE WAY TO AN AREA OF VFR CLOUDS MOVING IN FROM NORTHERN MINNESOTA...ALONG WITH SOME DIURNAL CU AT KSAW. FEW-SCATTERED VFR CLOUDS WILL REMAIN INTO TONIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 AM EDT WED JUL 29 2015 A STRONG LOW PRESSURE SYSTEM FOR LATE JULY IS LOCATED NEAR LAKE WINNIPEG EARLY THIS MORNING AND IT WILL LIFT NORTHEAST INTO FAR NORTHERN ONTARIO TODAY. MEANWHILE...IT WILL SWEEP A COLD FRONT CURRENTLY OVER CENTRAL LAKE SUPERIOR EAST ACROSS THE REST OF THE LAKE THIS MORNING. BEHIND THE FRONT...SOUTHWEST WINDS WILL INCREASE THROUGH THE MORNING OVER THE WESTERN HALF OF THE LAKE AND PRODUCE GALES TO 35-40KTS. THERE COULD BE A FEW GUSTS IN THE 40-45KT RANGE TOWARDS ISLE ROYALE THIS AFTERNOON. THESE WINDS WILL DECREASE AND SHIFT TO THE WEST THIS EVENING AS THE FIRST IN A SERIES OF TROUGHS MOVE ACROSS LAKE SUPERIOR THROUGH SUNDAY MORNING (ASSOCIATED WITH THE SURFACE LOW SLOWLY DRIFTING OVER HUDSON BAY). THERE IS THE POTENTIAL FOR GALES OUT OF THE WEST-NORTHWEST TONIGHT BEHIND THE SECONDARY TROUGH AS THE PRESSURE GRADIENT REMAINS TIGHT OVER NORTHERN LAKE SUPERIOR. BUT EXPECT THE MARINE LAYER TO BE THE STRONGEST IN THAT AREA WITH THE WATER TEMPERATURES STILL IN THE UPPER 30S AND LOWER 40S. WILL ADD A MENTION OF GALE FORCE GUSTS FOR NOW. THE PRESSURE GRADIENT WILL GRADUALLY DECREASE THROUGH THE REST OF THE WEAK AS ADDITIONAL WEAK SURFACE TROUGHS MOVE SOUTHEAST ACROSS THE LAKE. EXPECT WINDS TO STAY BELOW 25KTS AFTER THURSDAY AND THROUGH THE WEEKEND. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162- 240>242-263. GALE WARNING FROM 11 AM THIS MORNING TO 11 PM EDT THIS EVENING FOR LSZ264. GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR LSZ245>247. GALE WARNING FROM 11 AM THIS MORNING TO 10 PM EDT THIS EVENING FOR LSZ243-244. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...VOSS AVIATION...SRF MARINE...SRF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
650 AM EDT WED JUL 29 2015 .NEAR TERM...(TODAY THROUGH TONIGHT) ISSUED AT 331 AM EDT WED JUL 29 2015 PERSISTENT HIGH PRESSURE HAS SHIFTED EAST OF MICHIGAN EARLY THIS MORNING AS A COLD FRONT APPROACHES FROM THE WEST. MID AND HIGH CLOUDS HAVE BEGUN TO INCREASE ALONG THE NE PERIPHERY OF THE CONVECTIVE CLOUD SHIELD GENERATED FROM THE MCS CURRENTLY IMPACTING IOWA...NRN MISSOURI AND NRN ILLINOIS. THIS CONVECTION IS FUELED BY A STRONG INSTABILITY AXIS (CAPES OF AROUND 3000 JOULES) AND 850 MB THETA E RIDGING PUNCHING THRU THE MISSISSIPPI VALLEY ATTM. FURTHER NORTH...OUR UPSTREAM RADARS SHOW A FEW SHOWERS AND EMBEDDED WEAK STORMS TRYING TO DEVELOP JUST EAST OF THE ARROWHEAD OF MINNESOTA OVER WRN LAKE SUPERIOR JUST AHEAD OF THE APPROACHING COLD FRONT. CONVECTION IS STRUGGLING DUE TO WEAK INSTABILITY (500 JOULES OR LESS) AND VERY LIMITED MOISTURE. LATEST NAM12...RAP13 AND HRRR ALL SUGGEST THE FOCUS FOR MEANINGFUL CONVECTIVE DEVELOPMENT WILL STAY SOUTH OF OUR CWA THRU TODAY WHERE STRONGER INSTABILITY AND MUCH BETTER MOISTURE WILL RESIDE. NORTHERN MICHIGAN IS ONCE AGAIN LOOKING AT THE PROSPECT THAT THE MAJORITY OF OUR CWA MAY MISS OUT ON AN OPPORTUNITY FOR SOME MUCH NEEDED RAIN TODAY. STILL...CHANCE POPS WILL REMAIN IN ORDER THRU THE DAY...WITH THE EXPECTATION THAT A NARROW LINE OF SCATTERED SHOWERS WITH SOME EMBEDDED THUNDERSTORMS WILL DEVELOP ALONG AND AHEAD OF THE COLD FRONT. WILL MAKE SOME MINOR TIMING ADJUSTMENTS TO THIS BAND OF PRECIP AS IT SLOWLY MOVES THRU OUR CWA TODAY...BUT WILL CERTAINLY KEEP POPS IN THE CHANCE CATEGORY. NO REAL CHANCE FOR STRONG TO SEVERE STORMS GIVEN LIMITED INSTABILITY AND MOISTURE AND UNIMPRESSIVE WIND FIELDS AHEAD OF THE FRONT. EXPECT ANOTHER VERY WARM DAY FOR NORTHERN MICHIGAN...BUT NOT AS WARM AS IT HAS BEEN THE PAST FEW DAYS. HIGH TEMPS WILL WARM WELL INTO THE 80S...BUT SHOULD REFRAIN FROM REACHING INTO THE 90S. OVERNIGHT LOWS WILL COOL BACK INTO THE 60S. && .SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT) ISSUED AT 331 AM EDT WED JUL 29 2015 (7/30)THURSDAY...WITH THE FRONTAL PASSAGE TODAY, THE TEMPERATURES FALL BACK TO NORMAL FOR THURSDAY. THERE ARE TWO CONCERNS FOR THE DAY AND INTO THE NIGHT. 1) CLOUD COVER, ESPECIALLY NEAR ANJ. THE 850 MB RH IS AROUND 90%, AND WITH THE 850 MB TEMPERATURES NEAR +10C, NEAR E UPPER, IT COULD BE CLOUDIER. WHICH LEADS TO 2) TEMPERATURES COULD END UP COOLER IF THERE ARE MORE CLOUDS IN E UPPER AND EVEN PARTS OF THE N LOWER IF THE CLOUDS MAKE IT DOWN FAR ENOUGH SOUTH, BUT THAT SEEMS ONLY TO ABOUT M-32 AT THE MOST. SOUTH OF M-32, HOWEVER, THERE IS A DIFFERENT CONCERN, FIRE WEATHER. WILL EXPECT THAT THE HIGH TEMPERATURES WILL REMAIN OVER 75F (CIPS ANALOG GUIDANCE SHOWS 70% AT THE TEMPERATURES>75F). WINDS WILL BE AROUND 15MPH AT THE 20FT LEVEL (SUSTAINED), WITH THE RH AROUND 30- 35%. AND WITH THE EXTENDED DRY PERIOD, WILL BE GOING WITH THE ELEVATED FIRE DANGER. (7/31)FRIDAY...THE DISCUSSION FOR THURSDAY COULD VERY WELL FIT FOR FRIDAY AS WELL, EXCEPT THAT THERE IS A WEAK SFC LOW TRYING TO MOVE INTO THE REGION AS THE 500 MB LOW SINKS A LITTLE MORE SOUTH AND BEGINS TO COOL THINGS DOWN A BIT. AGAIN THE COOLEST, PROBABLY CLOUDIEST AREA WILL BE NORTH OF M-32, WITH THE SOO DROPPING INTO THE LOWER 70S FOR HIGHS POSSIBLY. LOOKS LIKE WE ARE STILL AROUND 80S SOUTH OF M-32, AND WINDS WILL BE AGAIN BE CLOSE TO 15 MPH AT 20FT, SO THERE IS AN ELEVATED FIRE DANGER RISK, ALTHOUGH THE RH MAY NOT BE AS BAD THURSDAY. HOWEVER, IT WILL STILL BE AN ISSUE. && .LONG TERM...(SATURDAY THROUGH TUESDAY) ISSUED AT 331 AM EDT WED JUL 29 2015 WITH THE 500 MB LOW JUST NORTH OF JAMES BAY, WE GO BACK TO THE PATTERN THAT WE`VE HAD OVER N MICHIGAN THE LAST 2 YEARS WITH COOLER THAN NORMAL TEMPERATURES AND POSSIBLY SHOWERY CONDITIONS, BUT NOTHING APPRECIABLE, AT LEAST FOR THE TIME BEING. CIPS ANALOGS FALL RIGHT IN LINE WITH THE MEX NUMBERS AS WELL AS THE ECMWF IDEAS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY) ISSUED AT 650 AM EDT WED JUL 29 2015 OVERALL CONDITIONS WILL REMAIN VFR AT ALL NRN LWR MICHIGAN TAF SITES THRU WEDNESDAY NIGHT. A COLD FRONT WILL SWEEP THRU THE REGION TODAY. LIMITED MOISTURE AND ONLY WEAK INSTABILITY ALONG AND AHEAD OF THE FRONT WILL RESTRICT POPS TO ONLY CHANCE. EXPECT A BAND OF SCATTERED SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS WILL SLOWLY PUSH FROM WEST TO EAST THRU NRN LWR MICHIGAN THROUGHOUT THE DAY. WILL CONTINUE TO HANDLE WITH VCSH IN THE TAFS FOR NOW. SOUTH WINDS UNDER 10 KTS WILL SHIFT TO THE WEST IN THE WAKE OF THE FRONT AND WILL INCREASE TO 10 TO 15 KTS...WITH A FEW HIGHER GUSTS POSSIBLE. && .MARINE... ISSUED AT 331 AM EDT WED JUL 29 2015 CHANCES OF SHOWERS AND STORMS WILL INCREASE FROM WEST TO EAST TODAY AS A COLD FRONT SWINGS THROUGH NORTHERN MICHIGAN. WINDS AND WAVES WILL APPROACH SCA CRITERIA THIS AFTERNOON AND THIS EVENING AS WINDS SHIFT TO THE WEST AND STRENGTHEN BEHIND THE COLD FRONT. AT THIS POINT...EXPECT CONDITIONS WILL FALL JUST SHORT OF CRITERIA. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...NONE. LS...NONE. && $$ NEAR TERM...MLR SHORT TERM...JSL LONG TERM...JSL AVIATION...MLR MARINE...MLR
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
702 AM CDT WED JUL 29 2015 .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 311 AM CDT WED JUL 29 2015 08Z SURFACE ANALYSIS REVEALS THAT THE EAGERLY-AWAITED COLD FRONT (AND ITS NOTICEABLY LESS HUMID POST-FRONTAL AIR MASS) WAS TANTALIZINGLY CLOSE TO THE LSX CWA EARLY THIS MORNING. AT 08Z, THE FRONT STRETCHED FROM CENTRAL KS THROUGH EXTREME SOUTHEASTERN NEB AND THROUGH CENTRAL IA INTO WESTERN WI. A NOCTURNAL MCS AHEAD OF THE FRONT WAS MAKING STEADY SOUTHWARD PROGRESS BUT VERY SLOW EASTWARD PROGRESS. ADDITIONAL THUNDERSTORMS ARE POSSIBLE WITH THE FRONT TODAY AS IT MOVES INTO A MOIST AND UNSTABLE AIR MASS DURING THE AFTERNOON HOURS, AND THE OUTFLOW BOUNDARY MAY ALSO SERVE AS A TRIGGER FOR AFTN SH/TS. UNTIL THE COLD FRONT ARRIVES, THERE WILL BE VERY LITTLE CHANGE IN THE SOUPY AIR MASS STILL IN PLACE ACROSS THE REGION. THE TIMING OF THE COLD FRONT IS SUCH THAT ROUGHLY THE SOUTHERN TO SOUTHEASTERN HALF OF THE CWA SHOULD SEE ANOTHER DAY OF HOT/HUMID CONDITIONS, ALBEIT NOT AS OPPRESSIVE AS YESTERDAY. HEAT INDEX VALUES SHOULD BE CLOSER TO 105-109 IN THE WORST AREAS TODAY COMPARED TO THE HEAT INDICES OF 110-117 WHICH WERE OBSERVED YESTERDAY. DESPITE THE SLIGHTLY LOWER HEAT INDEX VALUES WHICH ARE EXPECTED TODAY, THE EXCESSIVE HEAT WARNING STILL LOOKS APPROPRIATE BECAUSE IT IS THE CUMULATIVE EXPOSURE TO EXCESSIVE HEAT WHICH NEGATIVELY AFFECTS THE HUMAN BODY, AND TODAY WILL BE THE THIRD OR FOURTH DAY OF SUCH CONDITIONS FOR SOME AREAS. KANOFSKY .LONG TERM: (TONIGHT THROUGH TUESDAY) ISSUED AT 311 AM CDT WED JUL 29 2015 A TWO-DAY RESPITE FROM THE OPPRESSIVE HEAT/HUMIDITY IS EXPECTED ON THU/FRI. TEMPERATURES SHOULD BE SEASONABLY WARM (UPPER 80S TO LOWER 90S), BUT THE DEW POINTS WILL BE MUCH LOWER THAN THEY HAVE BEEN RECENTLY. THE UPPER AIR PATTERN WILL HAVE TRANSITIONED TO NORTHWEST FLOW ALOFT BY FRIDAY DUE TO THE BUILDING RIDGE ACROSS THE WESTERN CONUS AND A TROUGH OVER THE EASTERN CONUS. MODELS SHOW THAT THIS NW FLOW PATTERN REMAINS UNCHANGED THROUGH EARLY NEXT WEEK. ALTHOUGH THE MODELS CONTINUE TO SHOW HINTS OF A SHORTWAVE OR TWO WHICH COULD SUPPORT CONVECTION (PERHAPS AS EARLY AS SATURDAY NIGHT), CONFIDENCE IN THE TIMING AND PLACEMENT OF THESE FEATURES IS LOW. TEMPERATURES LOOK SEASONABLY WARM IN THE UPPER 80S TO LOWER 90S THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. KANOFSKY && .AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 638 AM CDT WED JUL 29 2015 LARGE CONVECTIVE COMPLEX THAT BLANKETED MOST OF S IA AND N MO LATE YESTERDAY EVENING BECAME OUTFLOW DOMINATED SHORTLY AFTER 05Z...WITH MAIN ELEMENTS DEVELOPING/PROPAGATING SSW WHILE E EDGE REMAINED Q-STATIONARY BETWEEN KIRK-KUIN. IN THE SHORT TERM...E EDGE OF THIS DYING PRECIP AREA MAY CLIP KUIN OVER THE NEXT HOUR OR SO, WHILE DRY WEATHER WILL PREVAIL ELSEWHERE. VFR CONDITIONS ARE ANTICIPATED...WITH CLOUDS AOA 4KFT. CURRENT SURFACE ANALYSIS AND LATEST RAP GUIDANCE SUGGESTS TWO BOUNDARIES THAT COULD PROVIDE FOCUS FOR AFTERNOON CONVECTION...THE FIRST IS THE OUTFLOW FROM THE EARLY MORNING CONVECTION WHICH APPEARS TO BE PUSHING THROUGH STL AREA ATTM. THE SECOND BOUNDARY WILL BE THE ACTUAL SYNOPTIC FRONT. ITS CURRENT LOCATION IS BEING MASKED BY MESOSCALE IMPACTS OF OVERNIGHT CONVECTION BUT IT APPEARS TO BE OVER S CENTRAL/SE IA...AND RAP SUGGESTS IT WILL BE WITH FRONT NEAR THE STL METRO BY MIDDAY. CONVERGENCE WILL BE FAIRLY WEAK BUT THERE SHOULD CERTAINLY BE ENOUGH INSTABILITY TO CARRY CURRENT VCTS AT STL METRO TAF SITES IN THE EARLY AFTERNOON. HOWEVER...HAVE DROPPED MENTION OF VCTS AT KCOU SINCE CONVERGENCE ALONG SYNOPTIC FRONT SHOULD BE SOUTH OF THAT AREA. PREVAILING CONDITIONS ACROSS THE AREA FOR THE AFTERNOON HOURS SHOULD BE SCT- BKN CU 4-5KFT (WITH GREATEST CLOUD COVER NEAR/SOUTH OF COLD FRONT)...WITH THIS CU FIELD QUICKLY DISSIPATING DURING THE EARLY EVENING WITH LOSS OF HEATING AND AS THE DRIER POST-FRONTAL AIR ADVECTS INTO THE AREA. SPECIFICS FOR KSTL: SCATTERED CLOUDS AOA 4KFT ARE EXPECTED THIS MORNING...WITH CU FIELD AOA 4KFT BECOMING SCT-BKN BY LATE MORNING AND INTO THE AFTERNOON. HAVE CONTINUED VCTS IN THE 18-21 TIME FRAME AS SYNOPTIC FRONT WILL BE PASSING AT THAT TIME. CU FIELD SHOULD QUICKLY DISSIPATE HEADING INTO THE EARLY EVENING...WITH A FEW CLOUDS AOA 10KFT OVERNIGHT AND INTO EARLY THURSDAY. TRUETT && .LSX WATCHES/WARNINGS/ADVISORIES: MO...EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR CRAWFORD MO-FRANKLIN MO-IRON MO-JEFFERSON MO-MADISON MO-REYNOLDS MO- ST. CHARLES MO-ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE. GENEVIEVE MO-WASHINGTON MO. IL...EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR CLINTON IL-MADISON IL-MARION IL-MONROE IL-RANDOLPH IL-ST. CLAIR IL- WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
642 AM CDT WED JUL 29 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT WED JUL 29 2015 FOR THE MAJORITY OF THE CWA (ESPECIALLY NEB ZONES)...THIS SHOULD BE A PRETTY STRAIGHTFORWARD NEXT 24 HOURS...WITH A CONTINUED EXPECTATION OF DRY CONDITIONS AND SEASONABLY PLEASANT TEMPS/DEWPOINTS...ALTHOUGH IT MAY BE A SOMEWHAT CLOUDIER DAY THAN PREVIOUSLY THOUGHT. HOWEVER...THINGS GET A BIT TRICKIER SOUTHWARD INTO KS ZONES (ESPECIALLY OUR BOTTOM-MOST 3 COUNTIES)...AS THERE ARE SOME MODELS (FOR EXAMPLE THE GFS) SUGGESTING THAT THIS AREA WILL BE BRUSHED BY THE FAR NORTHERN EDGES OF SOMEWHAT BETTER SHOWER/WEAK THUNDERSTORM POTENTIAL THAT SHOULD MAINLY FOCUS JUST SOUTH OF THE CWA...ESPECIALLY TONIGHT. THAT BEING SAID...OTHER MODELS INCLUDING SIMULATED REFLECTIVITY FROM 4KM WRF/ARW RUNS (INCLUDING THE OFTEN-RELIABLE NSSL WRF) ARE MORE SUPPORTIVE OF THESE MEASURABLE RAIN CHANCES REMAINING JUST SOUTH OF THE CWA...ALBEIT A RATHER CLOSE CALL. TO MAKE A LONG STORY SHORTER...CONSIDERED ADDING A FORMAL SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS TO PARTS OF OUR KS COUNTIES FOR MUCH OF THIS TIME FRAME...BUT GIVEN THE MIXED MESSAGES IN THE MODEL WORLD...AND ALSO CONSIDERING THAT WE HAD BEEN CONSISTENTLY ADVERTISING A "DRY" WEDNESDAY-WEDNESDAY NIGHT FORECAST CWA-WIDE THESE PAST FEW DAYS...OPTED TO TAKE A "MIDDLE GROUND" APPROACH FOR NOW BY SIMPLY INSERTING A "SLIGHT CHANCE OF SPRINKLES" INTO OUR FAR SOUTHERN AREAS. THE INTENDED MESSAGE HERE IS THAT ALTHOUGH WE CONTINUE TO DOWNPLAY PRECIP CHANCES...THE SPRINKLE MENTION BETTER IMPLIES THAT CHANCES ARE NOT TRULY "ZERO" EITHER. OBVIOUSLY THE NEXT FEW SHIFTS WILL HAVE TO MONITOR THE LATEST TRENDS JUST IN CASE PRECIP CHANCES (POPS) AND POSSIBLY THUNDERSTORM POTENTIAL MAY NEED BEEFED UP A BIT IN THIS TRICKY SOUTHERN AREA. TAKING A LOOK AT THE HERE AND NOW AS OF 08Z/3AM: WE ARE ALREADY IN THE MIDST OF A "CLOSE CALL" REGARDING SHOWER/THUNDERSTORM CHANCES IN OUR FAR SOUTHERN CWA...AS A FAIRLY CONCENTRATED AXIS OF SHOWERS /NON-SEVERE STORMS EXTENDING FROM NORTHEAST-CENTRAL KS IS JUST BARELY REMAINING OUTSIDE OUR CWA FOR THE MOST PART. THIS CONVECTION IS FOCUSED SLIGHTLY NORTH OF THE SYNOPTIC SURFACE COLD FRONT POSITIONED OVER SOUTHERN AND EAST-CENTRAL KS...AND IS LARGELY TIED TO AN AXIS OF LOW-MID LEVEL CONVERGENCE/FRONTOGENESIS IN THE 850-700MB LAYER. NOT SURPRISINGLY...THE NORTHERN FRINGE OF THIS CONVECTION IS ALIGNED ALMOST PERFECTLY WITH THE NORTHERN FRINGES OF A VERY SLOWLY SOUTHWARD-SINKING ELEVATED INSTABILITY AXIS...WHICH CLEARED THE VAST MAJORITY OF THE CWA BEHIND THE COLD FRONTAL PASSAGE DURING THE PAST 24 HOURS. IN THE BIGGER PICTURE OF THE MID-UPPER LEVELS...WATER VAPOR SATELLITE AND THE LATEST MODEL DATA DEPICT LIMITED LARGE-SCALE FORCING OVER THE CENTRAL PLAINS...AS THE LOCAL REGION IS SANDWICHED BETWEEN ANTICYCLONIC FLOW ASSOCIATED WITH THE SOUTHERN PLAINS SUBTROPICAL HIGH...AND THE SOUTHERN EDGES OF STRONGER WESTERLY FLOW ASSOCIATED WITH THE VIGOROUS CLOSED LOW PRESSURE SYSTEM SLOWLY DEPARTING NORTHEAST ACROSS THE MANITOBA/ONTARIO BORDER AREA. HOWEVER...THERE IS EVIDENCE OF A SUBTLE DISTURBANCE PASSING NORTHEAST THROUGH SOUTHWEST KS ASSOCIATED WITH A CLUSTER OF CONVECTION NEAR DODGE CITY. WHILE 11-3.9 MICRON SATELLITE IMAGERY HAS REVEALED A LARGELY CLEAR NIGHT THUS FAR OVER MUCH OF THE CWA...AT LEAST A THIN VEIL OF HIGH CLOUDS IS INCREASINGLY SPREADING NORTHEAST INTO THE CWA FROM THE SOUTHWEST KS CONVECTION. AT THE SURFACE...THINGS ARE LARGELY PLAYING OUT AS EXPECTED TONIGHT...WITH THE SOUTHEASTERN REACH OF BROAD HIGH PRESSURE CENTERED OVER THE NORTHERN ROCKIES PROVIDING VERY LIGHT/MAINLY NORTHERLY BREEZES TO THE LOCAL AREA. THIS HIGH PRESSURE AXIS...COMBINED WITH THE WELCOMED PRESENCE OF NOTICEABLY DRIER AIR MARKED BY DEWPOINTS MAINLY IN THE 50S...HAS ALLOWED TEMPS TO FALL SLIGHTLY BELOW LATE-JULY NORMALS IN MOST AREAS...AND ULTIMATELY EXPECT OVERNIGHT LOWS TO RANGE FROM MID 50S NORTHWEST...NEAR 60 CENTRAL AND MID-60S SOUTH. NOW LOOKING AHEAD FORECAST-WISE: EARLY THIS MORNING (THROUGH 7AM): OTHER THAN A CONTINUED GRADUAL INCREASE IN HIGH CLOUDS SPREADING IN FROM THE SOUTHWEST...LITTLE CHANGE FROM THE CURRENT SITUATION EXPECTED. GIVEN THAT IT APPEARS THAT THE EXTREME SOUTHERN FRINGES OF THE CWA WILL CONTINUE TO BARELY MISS OUT ON THE CENTRAL-NORTHEAST KS CONVECTION...WILL BE REMOVING THE PREVIOUSLY-EXISTING SLIGHT CHANCE OF SHOWERS/STORMS IN OUR FAR SOUTH FOR THE PRE-DAWN HOURS. TODAY (7AM-7PM): SEE THE OPENING PARAGRAPH ABOVE FOR THE BASIC REASONING BEHIND INTRODUCING SPRINKLE POTENTIAL INTO OUR FAR SOUTHERN CWA IN KS. HOWEVER...BARRING AN UNEXPECTED NORTHWARD SHIFT IN THE ONGOING EARLY MORNING CONVECTION IN CENTRAL KS...PLAN ON MAINTAINING A THUNDERSTORM-FREE FORECAST GOING FORWARD INTO THE OFFICIAL DAYTIME FORECAST PERIOD. AGAIN...FOR THE MAJORITY OF THE CWA (ESSENTIALLY NEB ZONES)...CONFIDENCE IS STILL HIGH ENOUGH IN A DRY DAY TO PRECLUDE EVEN A SPRINKLE MENTION. THAT BEING SAID THOUGH...THE LAST FEW HRRR RUNS ACTUALLY DO TRY TO DROP A FEW SPRINKLES OUT OF AN INCREASING MID LEVEL CLOUD DECK...BUT WILL LARGELY IGNORE THIS FOR NOW WITH VERY LITTLE SUPPORT FROM OTHER MODELS AND GIVEN THAT THIS LIMITED MOISTURE IS LARGELY AT/ABOVE 600MB. IN THE MID-UPPER LEVELS...SEASONABLY STRONG WESTERLY FLOW PERSISTS OVERHEAD...WITH HINTS OF A SUBTLE DISTURBANCE PASSING THROUGH THE CWA...POSSIBLY INCLUDING THE REMNANTS OF THE AFOREMENTIONED SOUTHWEST KS ONE. MEANWHILE...THE NORTHERN EDGES OF THE ELEVATED INSTABILITY AXIS OVER KS SHOULD LARGELY STALL OUT JUST SOUTH OF THE CWA IN A WEST-T0-EAST FASHION. ALTHOUGH DO NOT HAVE A GREAT FEEL FOR CLOUD COVER TODAY...BEEFED UP SKY COVER PERCENTAGES SOLIDLY INTO PARTLY CLOUDY TERRITORY MOST AREAS FOR MOST OF THE DAY...AND THERE COULD EASILY BE PERIODS OF MOSTLY CLOUDY TOO...ESPECIALLY IF THE NAM IS CORRECT IN DEPICTING A FAIRLY WIDESPREAD COVERAGE OF MID-HIGH CLOUDS DEVELOPING IN RESPONSE TO THE AFOREMENTIONED WEAK DISTURBANCE(S) PASSING THROUGH. AT THE SURFACE...BROAD HIGH PRESSURE WILL PASS EASTWARD OVER THE HEART OF THE CWA...PROMOTING NOT ONLY LIGHT BREEZES THAT WILL LARGELY AVERAGE UNDER 10 MPH...BUT ALSO A GRADUALLY VARYING DIRECTION AS MANY PLACES SEE A TRANSITION FROM NORTHERLY TO EASTERLY TO SOUTHERLY BY LATE IN THE DAY. TEMP-WISE...WOULD NOT BE SURPRISED IF INCREASING CLOUDS HOLD THINGS BACK A TOUCH AND DID DROP SOME AREAS (INCLUDING TRI-CITIES) 1-2 DEGREES FROM PREVIOUS FORECAST...BUT OVERALL STILL CALLING FOR MOST OF THE CWA TO TOP OUT IN THE 82-85 RANGE...WHICH COMBINED WITH LIGHT WIND AND DEWPOINTS LARGELY IN THE 50S SHOULD MAKE FOR A VERY COMFORTABLE LATE JULY DAY. TONIGHT (7PM-7AM): AGAIN...SEE OPENING PARAGRAPH FOR FURTHER INSIGHT INTO THE DECISION TO ADD SPRINKLE POSSIBILITY INTO PARTS OF KS ZONES. ALTHOUGH MODEL DISCREPANCY CONTINUES REGARDING NORTHERN KS PRECIP POTENTIAL...ITS WORTH NOTING THAT THE VERY LATEST 06Z NAM HAS BACKED OFF THE NORTHWARD EXTENT OF SHOWER/THUNDERSTORM POTENTIAL...NOW KEEPING OVERNIGHT CONVECTION JUST SOUTH OF THE CWA (MUCH THE SAME PLACEMENT AS THE ONGOING ACTIVITY). IN THE MID-UPPER LEVELS TONIGHT...FLOW OVER THE CWA STARTS TO TURN EVER-SO-SLIGHTLY NORTHWESTERLY...IN RESPONSE TO THE SOUTHERN PLAINS RIDGE STARTING TO RETROGRADE WESTWARD A BIT. WHILE FAIRLY SUBTLE LOW-MID LEVEL LIFT/CONVERGENCE IS EXPECTED TO PROMOTE "SOME" COVERAGE OF SHOWERS/STORMS MAINLY JUST SOUTH OF THE CWA...THE VAST MAJORITY OF THE LOCAL AREA SHOULD REMAIN VOID OF EVEN SPRINKLES...WITH A LIKELY DECREASE IN MID-HIGH LEVEL CLOUDS AS WELL FROM THE DAYTIME...THUS PROMOTING MOSTLY CLEAR SKIES ESPECIALLY NORTH OF THE STATE LINE. AT THE SURFACE...LIGHT BREEZES WILL CONTINUE IN THE PRESENCE OF BROAD HIGH PRESSURE...BUT LIKELY TAKING ON MORE OF A SOUTHERLY AND/OR WESTERLY COMPONENT. ALL IN ALL...LOW TEMPS ACROSS MOST OF THE CWA MAY END UP BEING VERY SIMILAR TO THOSE OBSERVED THIS MORNING...BUT FOR NOW WILL AIM MOST PLACES VERY SLIGHTLY WARMER...WITH MOST OF THE CWA BOTTOMING OUT SOMEWHERE IN THE 58-63 RANGE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 400 AM CDT WED JUL 29 2015 AFTER A VERY NICE WEDNESDAY WE WILL WARM RIGHT BACK UP INTO THE UPPER 80S TO LOWER 90S FOR THURSDAY THROUGH THE WEEKEND AND INTO NEXT MONDAY...BEFORE PERHAPS ANOTHER COOL DOWN NEXT TUESDAY. WE DO HAVE SEVERAL RAIN CHANCES...BUT CONFIDENCE IN SEEING PRECIPITATION IS NOT THAT HIGH ON ANY GIVEN DAY. MOST LOCATIONS WILL LIKELY END UP DRY THROUGH FRIDAY...BUT WE WILL SEE AT LEAST A FEW MORE CHANCES OF RAIN THEREAFTER. THURSDAY AND FRIDAY...THE HUMIDITY WILL BEGIN TO WORK BACK INTO THE REGION. DEWPOINTS WILL RISE FROM THEIR LOW POINT IN THE LOWER 50S TODAY...TO AROUND 60 ON THURSDAY...AND INTO THE MID 60S BY FRIDAY. THE SFC WIND WILL BE FAIRLY LIGHT...BUT IS EXPECTED TO BECOME GENERALLY SOUTHERLY...WHICH WILL HELP TO WARM THINGS UP A COUPLE DEGREES BACK TO AROUND NORMAL IN THE UPPER 80S TO AROUND 90. THE UPPER RIDGE OVER THE SOUTHERN PLAINS WILL RETROGRADE BACK TO THE WEST AND SET UP OVER THE DESERT SOUTHWEST. IN OUR AREA THERE WILL BE AN AREA OF WEAK SFC CONVERGENCE ACROSS OUR NORTHERN AND EASTERN ZONES FRIDAY AFTERNOON THAT COULD POP A FEW ISOLATED THUNDERSTORMS BASED ON THE 00Z NAM AND 00Z GFS. CONFIDENCE IS LOW AND CONVECTION WOULD LIKELY BE VERY HIT AND MISS WITH MOST FOLKS LIKELY MISSING OUT ON IT. SATURDAY THROUGH MONDAY...NORTHWESTERLY FLOW ALOFT WILL SEND US A FEW SHORTWAVES AND SUBSEQUENT THUNDERSTORM CHANCES. ONE SUCH SHORTWAVE IS EVIDENT IN THE 00Z GFS AND 00Z ECMWF SATURDAY AFTERNOON/EVENING. THEREFORE...WILL THROW SOME CHANCE POPS IN THE FORECAST WITH THE HIGHEST POPS BEING ACROSS NORTHERN AND EASTERN ZONES. OVERALL...AT LEAST THE WAY IT LOOK RIGHT NOW...PRECIPITATION CHANCES WILL STILL BE FAIRLY LOW AT LESS THAN 50/50. WE SHOULD BE IN BETWEEN SHORTWAVES ON SUNDAY SO CONFIDENCE IN DRY WEATHER IS FAIRLY GOOD FOR SUNDAY. THE NEXT SHORTWAVE ENTERS THE PICTURE ON MONDAY BUT FORECAST MODELS DIFFER ON THE SPEED OF THE ASSOCIATED FRONT. GIVEN THE EXPECTATION OF HAVING SOME UPPER LEVEL SUPPORT IN THE GENERAL AREA FROM THIS UPPER WAVE...WILL CALL FOR CHANCE POPS. TEMPERATURES WILL REMAIN NEAR NORMAL DURING THIS STRETCH...OR GENERALLY IN THE UPPER 80S TO LOWER 90S. TUESDAY...CONFIDENCE IS PRETTY LOW THIS FAR OUT GIVEN THE NORTHWESTERLY FLOW REGIME. THEREFORE...WILL STICK WITH THE SUPERBLEND OF ALL MODELS...WHICH GIVES US A SMALL CHANCE OF PRECIPITATION AND SLIGHTLY COOLER TEMPERATURES WITH HIGHS IN THE MID TO UPPER 80S. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 642 AM CDT WED JUL 29 2015 BARRING UNEXPECTED DEVELOPMENTS...THIS SHOULD BE A VERY QUIET 24 HOURS IN THE AVIATION DEPARTMENT. FIRST OFF...NOT ANTICIPATING ANY PRECIPITATION/THUNDERSTORMS. CONFIDENCE IS ACTUALLY VERY HIGH IN VFR CEILING AND VISIBILITY...ALTHOUGH MUCH OF THE DAY WILL LIKELY FEATURE A DECENT AMOUNT OF MID-HIGH CLOUD COVER. AS FOR SURFACE WIND...THE VAST MAJORITY OF THE PERIOD SHOULD FEATURE SPEEDS AT/BELOW 6KT...AND WITH A HIGH PRESSURE AXIS CENTERED OVER THE REGION...DIRECTION WILL BE RATHER VARIABLE IN NATURE TODAY BEFORE POSSIBLY BECOMING A BIT MORE CONSISTENT FROM THE SOUTHWEST TONIGHT. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...WESELY AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1158 AM EDT WED JUL 29 2015 .SYNOPSIS... HOT TEMPERATURES ARE EXPECTED ONCE AGAIN ACROSS THE NORTH COUNTRY WITH HIGHS IN THE UPPER 80S TO LOWER 90S. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE HIGHER TERRAIN THIS AFTERNOON...BUT A MUCH BETTER CHANCE FOR THUNDERSTORMS WILL COME ON THURSDAY AS A COLD FRONT MOVES ACROSS THE REGION. NUMEROUS THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE NORTHERN ADIRONDACKS OF NEW YORK BY MIDDAY ON THURSDAY AND MOVE EAST THROUGH THE AFTERNOON. THESE THUNDERSTORMS WILL ALSO HAVE THE POTENTIAL TO BE STRONG OR SEVERE WITH STRONG AND GUSTY WINDS...HAIL...AND HEAVY DOWNPOURS. COOLER AND DRIER WEATHER RETURNS ON FRIDAY AS THE COLD FRONT EXITS THE AREA THURSDAY NIGHT. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 1155 AM EDT WEDNESDAY...GOING FORECAST IN GOOD SHAPE. TEMPERATURES ARE ALREADY IN THE MID 80S WITH SEVERAL MORE HOURS OF HEATING TO GO. LATEST RAP ANALYSIS ALSO SHOWING BETWEEN 500-1500 J/KG OF MLCAPE...BUT STILL CAPPED FOR THE TIME BEING. CU FIELD IS STARTING TO FORM OVER THE HIGHER ELEVATIONS. AN ISOLATED SHOWER/STORM REMAINS POSSIBLE THIS AFTERNOON. PREVIOUS DISCUSSION FROM 958 AM WEDNESDAY... RIDGING ALOFT AND AT THE SURFACE WILL PROVIDE FOR ANOTHER MOSTLY SUNNY AND HOT DAY. DO HAVE SOME THIN CIRRUS SPILLING OVER THE TOP OF THE RIDGE BUT NOT ENOUGH TO OBSCURE THE SUN. WILL ALSO HAVE A CU-FIELD DEVELOP THIS AFTERNOON...MAINLY OVER THE TERRAIN. LOW LEVEL THERMAL FIELDS ARE ABOUT 2C WARMER THAN YESTERDAY...WHICH SHOULD RESULT IN TEMPERATURES ABOUT 3 DEGREES WARMER THAN YESTERDAY. THIS WILL YIELD HIGHS IN THE UPPER 80S AND LOWER 90S AREA-WIDE. THE HEAT COMBINED WITH DEW POINTS IN THE MID/UPPER 60S WILL PRODUCE HEAT INDEX VALUES OF 91 TO 97 DEGREES. THE HEAT/HUMIDITY WILL ALSO LEAD TO THE DEVELOPMENT OF BETWEEN 500-1500 J/KG OF MLCAPE. MOST OF THE REGION SHOULD REMAIN CAPPED...BUT THE HIGHER TERRAIN MAY PRODUCE JUST ENOUGH LIFT TO TRIGGER AN ISOLATED SHOWER OR THUNDERSTORM OR TWO. WITH ONLY LIMITED WIND SHEAR (20-25 KNOTS 0-6KM)...A SEVERE THREAT IS NOT ANTICIPATED. && .SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/... AS OF 414 AM EDT WEDNESDAY...WE ARE STILL LOOKING AT THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS ON THURSDAY ACROSS MUCH OF THE AREA. A SHARP COLD FRONT WILL MOVE INTO THE SAINT LAWRENCE VALLEY BY MIDDAY. THE MOISTURE GRADIENT ASSOCIATED WITH THE FRONT IS RATHER SHARP...SO THIS BOUNDARY WILL BE A GOOD SOURCE OF LIFT AS IT MOVES EASTWARD THURSDAY AFTERNOON. THE ATMOSPHERE WILL DESTABILIZE IN ADVANCE OF THE FRONT WITH WITH HIGHS IN THE MID 80S TO LOWER 90S AND DEW POINTS WILL INTO THE 60S. STILL EXPECTING THIS TO RESULT IN CAPE VALUES IN THE 1000-1500 J/KG RANGE. WHAT CONTINUES TO STAND OUT IS THE INCREASING DEEP LAYER SHEAR OVER THE TOP OF THE COLD FRONT AND INSTABILITY AXIS TO SUPPORT THE DEVELOPMENT OF ORGANIZED STORMS WHICH BASED ON THE STRENGTH OF THE INSTABILITY AND SHEAR...SHOULD BECOME STRONG TO SEVERE. AT THIS TIME...THINKING STORMS FORM OVER THE NORTHERN ADIRONDACKS AND QUICKLY INTENSIFY WITH THE CHAMPLAIN VALLEY AND REMAINDER OF VERMONT HAVING THE BEST CHANCE TO EXPERIENCE THE STRONG TO SEVERE STORMS. WILL INCLUDE THE MENTION OF GUSTY WINDS...HAIL...AND HEAVY DOWNPOURS IN THE FORECAST. NARROW BAND OF STORMS EXITS THE AREA BY EARLY EVENING AND WITH COLD FRONT ALSO EXITING THE AREA...COOLER AND DRIER WEATHER SHOULD MOVE IN FOR THURSDAY NIGHT AND FRIDAY WITH HIGHS ON FRIDAY CLOSER TO SEASONAL NORMALS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 310 AM EDT WEDNESDAY...LITTLE OVERALL CHANGE FROM PREVIOUS FORECASTER THINKING IN REGARDS TO THE UPCOMING PATTERN FOR THE EXTENDED PERIOD WITH MEDIUM RANGE GLOBAL MODELS REMAINING IN GOOD AGREEMENT DEPICTING A LARGE-SCALE POLAR UPPER LOW TAKING RESIDENCE OVER HUDSONS BAY. THIS LEAVES THE NORTHEAST IN A PERSISTENT BROAD UPPER TROUGH WITH SEVERAL PIECES OF WEAK SHORTWAVE ENERGY MOVING THROUGH THE FLOW ALOFT. FIRST PIECE MOVES THROUGH ON SATURDAY AND THIS ENERGY COMBINED WITH DAYTIME HEATING MAY TRIGGER A FEW SHOWERS AND/OR THUNDERSTORMS, THOUGH WITH THE LACK OF ANY STRONG FORCING AND LIMITED DEEP LAYER MOISTURE RAINFALL SHOULD BE SHOWERY IN NATURE AND ON THE LIGHT SIDE. BEST CHANCES FOR SHOWERS/STORMS DURING THE PERIOD STILL LOOK TO BE MONDAY AND ESPECIALLY TUESDAY AS A COUPLE STRONGER SHORTWAVES SHIFT THROUGH THE REGION AS THE UPPER LOW DIGS SLIGHTLY SOUTHWARD FROM JAMES BAY INTO THE GREAT LAKES. THIS WILL ALLOW A WEAK COLD FRONT TO MOVE ACROSS THE AREA AS A BETTER FOCUS FOR PRECIPITATION. TEMPERATURES THROUGH THE PERIOD WILL BE NEAR NORMAL WITH HIGHS IN THE MID 70S TO LOWER 80S, AND LOWS IN THE MID 50S TO LOWER 60S. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... THROUGH 12Z THURSDAY...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH SCT-BKN MID/HIGH CLOUDS DRIFTING THROUGH THE REGION. LIGHT WINDS EARLY THIS MORNING BECOME WEST-SOUTHWEST (EXCEPT SOUTHEAST AT KPBG) AT 5 TO 10 KNOTS THROUGH THE DAY, GOING CALM AGAIN AFTER 00Z. WINDS JUST OFF THE SURFACE PICK UP TONIGHT AHEAD OF AN APPROACHING COLD FRONT WHICH SHOULD INHIBIT ANY FOG. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... 12Z THU - 00Z FRI: VFR WITH BRIEF MVFR/IFR IN SHOWERS/STORMS. ISOLATED SEVERE TURBULENCE/WINDS/HAIL POSSIBLE. 00Z FRI - 12Z SAT: MAINLY VFR. CHANCE MVFR/IFR FOG. 12Z SAT - 00Z MON: MAINLY VFR. CHANCE SHRA/TSRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...EVENSON/MUCCILLI SHORT TERM...EVENSON LONG TERM...LAHIFF AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
908 AM EDT WED JUL 29 2015 .SYNOPSIS...A WEAK SURFACE TROUGH WILL REMAIN OVER CENTRAL NC TODAY AS AN UPPER LEVEL RIDGE BRIEFLY BUILDS OVERHEAD. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY AND SINK SOUTH OF THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 900 AM WEDNESDAY... WITH REGARD TO THE REMAINDER OF THIS MORNING...THERE WILL BE LITTLE CHANGE IN THE FORECAST OTHER THAN TO CONFINE SHOWER CHANCES TO THE NE COASTAL PLAIN (I.E. WARREN/HALIFAX COUNTIES) THROUGH NOON. A NEW DISCUSSION FOR THIS AFT/EVE INTO TONIGHT WILL BE POSTED EARLY THIS AFTERNOON. -VINCENT PRIOR DISCUSSION: NORTHWESTERLY FLOW ALOFT WILL SHIFT TO A LITTLE MORE NORTHERLY TODAY AS THE CENTRAL US RIDGE BUILDS EAST IN RESPONSE TO A STRONG SHORTWAVE CROSSING THE UPPER MIDWEST. WATER VAPOR IMAGERY AND RAP H5 VORTICITY SUGGEST A COUPLE WEAK DISTURBANCES WILL DROP SOUTH ACROSS THE AREA...BUT NEITHER APPEARS TO BE VERY STRONG AND THERE SHOULDN`T BE MUCH IMPACT GIVEN THAT HEIGHTS BUILD ALOFT AND INSTABILITY WILL BE WEAK. AT THE SURFACE...A TROUGH EXTENDING SOUTH FROM THE MID ATLANTIC STATES APPEARS TO HAVE SUNK A LITTLE FURTHER SOUTH IN RESPONSE TO THE LAST EVENINGS CONVECTION NEAR THE NC-VA BORDER...NOW SITUATED FROM ROUGHLY DAVIDSON COUNTY NORTHEAST TO GRANVILLE COUNTY. THIS COULD SERVE AS AN ADDITIONAL FOCUS FROM SOME WIDELY SCATTERED CONVECTION...IN ADDITION TO CONVECTION OVER THE HIGHER TERRAIN...AND RECENT RUNS OF THE HRRR HINT AT DEVELOPMENT BY MIDDAY. IF NOTHING FORMS ON THIS BOUNDARY AND/OR IT WASHES OUT...THEN CONVECTION WILL BE FOCUS OVER THE NORTHWEST PIEDMONT AND SHOULDN`T HAVE MUCH OPPORTUNITY TO MOVE EAST GIVEN WEAK NORTHERLY STEERING FLOW. OVERALL...THE COVERAGE OF SHOWERS/STORMS IS EXPECTED TO BE LESS THAN THE PAST COUPLE OF DAYS. HIGHS SHOULD BE ABLE TO REACH THE FULL SUN POTENTIAL AS IR IMAGERY SHOWS LITTLE IN THE WAY OF UPSTREAM CLOUD COVER TO INHIBIT HEATING. HIGHS 88-93. CONVECTION SHOULD SEND A LITTLE SOONER THIS EVENING WITH LOSS OF HEATING AND NO SUPPORT FROM DISTURBANCES ALOFT. THERE IS A DISTURBANCE OVER SOUTHERN MICHIGAN THIS MORNING THAT IS FORECAST TO DIVE SOUTH LATE TONIGHT AND EARLY THURSDAY...WHICH COULD CONCEIVABLY CAUSE SOME REDEVELOPMENT OF SHOWERS...MAINLY WEST..BY EARLY THURSDAY MORNING...BUT GUIDANCE DOESN`T SHOW MUCH ACTIVITY...SO WILL LEAVE THE OVERNIGHT FORECAST DRY. LOWS WILL BE IN THE LOWER 70S. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 400 AM WEDNESDAY... A COLD FRONT...ATTENDANT TO AN OCCLUDED LOW WAY TO THE NORTH OVER CENTRAL CANADA...WILL APPROACH FROM THE NORTHWEST ON THURSDAY. THE PREFRONTAL LEE TROUGH WILL SHARPEN IN RESPONSE TO THE APPROACHING FRONT... BUT WITH INSTABILITY STILL EXPECTED TO BE RELATIVELY WEAK...MODELS ARE SURPRISINGLY DRY DURING THE DAY ON THURSDAY. THERE IS A DISTURBANCE FORECAST TO DIVE SOUTH INTO THE AREA EARLY THURSDAY...AS MENTIONED IN THE NEAR TERM DISCUSSION...AND EVOLUTION OF THIS FEATURE MAY BE WORTH WATCHING TO SEE IF/HOW IT COULD IMPACT CONVECTION INITIATION ON THURSDAY. THE FRONT WILL PUSH INTO THE AREA THURSDAY EVENING...BUT POOR DIURNAL TIMING AND FORCING LIMITED TO JUST FRONTAL CONVERGENCE SHOULD RESULT IN JUST SCATTERED CONVECTION AND NO WIDESPREAD SEVERE WEATHER. HIGHS THURSDAY HAVE THE POTENTIAL TO REACH THE LOW TO MID 90S ACROSS THE ENTIRE AREA AS THE 850MB THERMAL RIDGE SHIFTS OVER THE AREA AHEAD OF THE FRONT AND 850MB TEMPS REACH 19-20C. SOME HIGH CLOUDS ASSOCIATED WITH THE FRONTAL ZONE WILL SPREAD ACROSS THE AREA BUT CURRENTLY DO NOT LOOK WIDESPREAD OR THICK ENOUGH TO IMPACT HIGHS. LOWS THURSDAY NIGHT WILL BE MOSTLY IN THE LOW TO MID 70S...ESPECIALLY INT HE SOUTHEAST WHERE THE FRONT WILL ONLY SLOW REACH BY FRIDAY MORNING. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 410 AM WEDNESDAY... FORECAST RATIONALE REMAINS GENERALLY UNCHANGED FROM PREVIOUS DAYS. THE MODELS REMAIN IN GOOD AGREEMENT REGARDING THE PERSISTENCE OF AN EASTERN CONUS TROUGH FORECAST TO DEVELOP DURING THE NEAR AND SHORT TERM...COINCIDENT WITH THE RETROGRESSION OF A SUB-TROPICAL RIDGE FROM THE SOUTHERN PLAINS AND MID-MS VALLEY WEST TO THE FOUR CORNERS REGION. MEANWHILE IN THE LOW LEVELS...THE MODELS AGREE THAT A COLD FRONT RELATED TO A POTENT UPPER LOW OVER SOUTHERN MANITOBA THIS MORNING WILL BE INVOF THE I-95 CORRIDOR FRI MORNING...THEN DRIFT SOUTHEAST THROUGH THE COASTAL PLAIN THROUGH THE MIDDAY-AFTERNOON HOURS. THIS GRADUALLY DIFFUSING BOUNDARY WILL BE THE FOCUS FOR SHOWERS AND STORMS CENTERED OVER THE EASTERN CAROLINAS FRI-SUN...WHILE A DRIER AIR MASS BOTH AT THE SURFACE AND ALOFT SETTLES ACROSS THE WESTERN... AND MUCH OF THE CENTRAL PART...OF NC. AS THE PREVIOUS SHIFT NOTED...ANY NORTHWESTWARD SHIFT IN THE FRONTAL POSITION AND ASSOCIATED AXIS OF TROPICAL MOISTURE --CHARACTERIZED BY PRECIPITABLE WATER VALUES AOA TWO INCHES-- WOULD RESULT IN A WETTER WEEKEND FOR PARTICULARLY EAST-CENTRAL NC. THOUGH MODEL SPREAD INCREASES BY THE EARLY-MIDDLE OF NEXT WEEK...THE MODELS TO VARYING DEGREES HAVE HINTED THAT THE TROPICAL MOISTURE MAY GET DRAWN NORTH/INCORPORATED INTO THE LONGWAVE TROUGH BY LATE SUN-MON...AT WHICH TIME THE PROBABILITY OF SHOWERS AND STORMS ARE MORE LIKELY TO INCREASE THROUGHOUT CENTRAL NC. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 640 AM WEDNESDAY... DENSE FOG THIS AT KINT THIS MORNING IS VERY ISOLATED AND WILL IMPROVE QUICKLY...WITH VFR CONDITIONS LIKELY TO RETURN BY 13Z. ELSEWHERE...SOME SCATTERED SHOWERS HAVE DEVELOPED NORTH OF KRDU/KRWI AND ARE DRIFTING SLOWLY TO THE EAST-NORTHEAST...GENERALLY AWAY FROM THE TERMINALS. SOME ADDITIONAL SHOWERS MAY DEVELOP IN THE NEXT COUPLE HOURS...BUT THE IMPACTS OF THE SHOWERS SHOULD BE LIMITED AND VFR CONDITIONS SHOULD PREVAIL. AN UPPER LEVEL RIDGE WILL BRIEFLY BUILD OVER THE REGION TODAY AND MAY LIMIT STORM COVERAGE MORE SO THAN IN PRIOR DAYS. AS SUCH...WILL NOT MENTION THUNDER IN THE CURRENT TAF...BUT CHANCES WILL BE GREATEST AT KGSO AND KINT ONCE AGAIN. STRATUS IS POSSIBLE AGAIN TONIGHT...AND CONFIDENCE IS A LITTLE HIGHER THAN IN PAST NIGHTS GIVEN A SLIGHTLY STRONGER WIND JUST ABOVE THE SURFACE AND A BETTER AGREEMENT ON AMONG MODELS...WITH THE BEST CHANCE FROM KFAY TO KRWI. OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY...WITH SOME PREFRONTAL CONVECTION POSSIBLE THURSDAY AFTERNOON. THE FRONT WILL THEN PUSH THROUGH THE AREA THURSDAY NIGHT AND SETTLE SOUTH OF THE AREA ON FRIDAY. IF THIS FRONT DOES PUSH ALL THE WAY THROUGH THE AREA...THEN VFR CONDITIONS WILL BE MUCH MORE LIKELY FOR THE UPCOMING WEEKEND. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...22 LONG TERM...26 AVIATION...22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
640 AM EDT WED JUL 29 2015 .SYNOPSIS...A WEAK SURFACE TROUGH WILL REMAIN OVER CENTRAL NC TODAY AS AN UPPER LEVEL RIDGE BRIEFLY BUILDS OVERHEAD. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY AND SINK SOUTH OF THE AREA THROUGH THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 350 AM WEDNESDAY... NORTHWESTERLY FLOW ALOFT WILL SHIFT TO A LITTLE MORE NORTHERLY TODAY AS THE CENTRAL US RIDGE BUILDS EAST IN RESPONSE TO A STRONG SHORTWAVE CROSSING THE UPPER MIDWEST. WATER VAPOR IMAGERY AND RAP H5 VORTICITY SUGGEST A COUPLE WEAK DISTURBANCES WILL DROP SOUTH ACROSS THE AREA...BUT NEITHER APPEARS TO BE VERY STRONG AND THERE SHOULDN`T BE MUCH IMPACT GIVEN THAT HEIGHTS BUILD ALOFT AND INSTABILITY WILL BE WEAK. AT THE SURFACE...A TROUGH EXTENDING SOUTH FROM THE MID ATLANTIC STATES APPEARS TO HAVE SUNK A LITTLE FURTHER SOUTH IN RESPONSE TO THE LAST EVENINGS CONVECTION NEAR THE NC-VA BORDER...NOW SITUATED FROM ROUGHLY DAVIDSON COUNTY NORTHEAST TO GRANVILLE COUNTY. THIS COULD SERVE AS AN ADDITIONAL FOCUS FROM SOME WIDELY SCATTERED CONVECTION...IN ADDITION TO CONVECTION OVER THE HIGHER TERRAIN...AND RECENT RUNS OF THE HRRR HINT AT DEVELOPMENT BY MIDDAY. IF NOTHING FORMS ON THIS BOUNDARY AND/OR IT WASHES OUT...THEN CONVECTION WILL BE FOCUS OVER THE NORTHWEST PIEDMONT AND SHOULDN`T HAVE MUCH OPPORTUNITY TO MOVE EAST GIVEN WEAK NORTHERLY STEERING FLOW. OVERALL...THE COVERAGE OF SHOWERS/STORMS IS EXPECTED TO BE LESS THAN THE PAST COUPLE OF DAYS. HIGHS SHOULD BE ABLE TO REACH THE FULL SUN POTENTIAL AS IR IMAGERY SHOWS LITTLE IN THE WAY OF UPSTREAM CLOUD COVER TO INHIBIT HEATING. HIGHS 88-93. CONVECTION SHOULD SEND A LITTLE SOONER THIS EVENING WITH LOSS OF HEATING AND NO SUPPORT FROM DISTURBANCES ALOFT. THERE IS A DISTURBANCE OVER SOUTHERN MICHIGAN THIS MORNING THAT IS FORECAST TO DIVE SOUTH LATE TONIGHT AND EARLY THURSDAY...WHICH COULD CONCEIVABLY CAUSE SOME REDEVELOPMENT OF SHOWERS...MAINLY WEST..BY EARLY THURSDAY MORNING...BUT GUIDANCE DOESN`T SHOW MUCH ACTIVITY...SO WILL LEAVE THE OVERNIGHT FORECAST DRY. LOWS WILL BE IN THE LOWER 70S. && .SHORT TERM /THURSDAY AND THURSDAY NIGHT/... AS OF 400 AM WEDNESDAY... A COLD FRONT...ATTENDANT TO AN OCCLUDED LOW WAY TO THE NORTH OVER CENTRAL CANADA...WILL APPROACH FROM THE NORTHWEST ON THURSDAY. THE PREFRONTAL LEE TROUGH WILL SHARPEN IN RESPONSE TO THE APPROACHING FRONT... BUT WITH INSTABILITY STILL EXPECTED TO BE RELATIVELY WEAK...MODELS ARE SURPRISINGLY DRY DURING THE DAY ON THURSDAY. THERE IS A DISTURBANCE FORECAST TO DIVE SOUTH INTO THE AREA EARLY THURSDAY...AS MENTIONED IN THE NEAR TERM DISCUSSION...AND EVOLUTION OF THIS FEATURE MAY BE WORTH WATCHING TO SEE IF/HOW IT COULD IMPACT CONVECTION INITIATION ON THURSDAY. THE FRONT WILL PUSH INTO THE AREA THURSDAY EVENING...BUT POOR DIURNAL TIMING AND FORCING LIMITED TO JUST FRONTAL CONVERGENCE SHOULD RESULT IN JUST SCATTERED CONVECTION AND NO WIDESPREAD SEVERE WEATHER. HIGHS THURSDAY HAVE THE POTENTIAL TO REACH THE LOW TO MID 90S ACROSS THE ENTIRE AREA AS THE 850MB THERMAL RIDGE SHIFTS OVER THE AREA AHEAD OF THE FRONT AND 850MB TEMPS REACH 19-20C. SOME HIGH CLOUDS ASSOCIATED WITH THE FRONTAL ZONE WILL SPREAD ACROSS THE AREA BUT CURRENTLY DO NOT LOOK WIDESPREAD OR THICK ENOUGH TO IMPACT HIGHS. LOWS THURSDAY NIGHT WILL BE MOSTLY IN THE LOW TO MID 70S...ESPECIALLY INT HE SOUTHEAST WHERE THE FRONT WILL ONLY SLOW REACH BY FRIDAY MORNING. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 410 AM WEDNESDAY... FORECAST RATIONALE REMAINS GENERALLY UNCHANGED FROM PREVIOUS DAYS. THE MODELS REMAIN IN GOOD AGREEMENT REGARDING THE PERSISTENCE OF AN EASTERN CONUS TROUGH FORECAST TO DEVELOP DURING THE NEAR AND SHORT TERM...COINCIDENT WITH THE RETROGRESSION OF A SUB-TROPICAL RIDGE FROM THE SOUTHERN PLAINS AND MID-MS VALLEY WEST TO THE FOUR CORNERS REGION. MEANWHILE IN THE LOW LEVELS...THE MODELS AGREE THAT A COLD FRONT RELATED TO A POTENT UPPER LOW OVER SOUTHERN MANITOBA THIS MORNING WILL BE INVOF THE I-95 CORRIDOR FRI MORNING...THEN DRIFT SOUTHEAST THROUGH THE COASTAL PLAIN THROUGH THE MIDDAY-AFTERNOON HOURS. THIS GRADUALLY DIFFUSING BOUNDARY WILL BE THE FOCUS FOR SHOWERS AND STORMS CENTERED OVER THE EASTERN CAROLINAS FRI-SUN...WHILE A DRIER AIR MASS BOTH AT THE SURFACE AND ALOFT SETTLES ACROSS THE WESTERN... AND MUCH OF THE CENTRAL PART...OF NC. AS THE PREVIOUS SHIFT NOTED...ANY NORTHWESTWARD SHIFT IN THE FRONTAL POSITION AND ASSOCIATED AXIS OF TROPICAL MOISTURE --CHARACTERIZED BY PRECIPITABLE WATER VALUES AOA TWO INCHES-- WOULD RESULT IN A WETTER WEEKEND FOR PARTICULARLY EAST-CENTRAL NC. THOUGH MODEL SPREAD INCREASES BY THE EARLY-MIDDLE OF NEXT WEEK...THE MODELS TO VARYING DEGREES HAVE HINTED THAT THE TROPICAL MOISTURE MAY GET DRAWN NORTH/INCORPORATED INTO THE LONGWAVE TROUGH BY LATE SUN-MON...AT WHICH TIME THE PROBABILITY OF SHOWERS AND STORMS ARE MORE LIKELY TO INCREASE THROUGHOUT CENTRAL NC. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 640 AM WEDNESDAY... DENSE FOG THIS AT KINT THIS MORNING IS VERY ISOLATED AND WILL IMPROVE QUICKLY...WITH VFR CONDITIONS LIKELY TO RETURN BY 13Z. ELSEWHERE...SOME SCATTERED SHOWERS HAVE DEVELOPED NORTH OF KRDU/KRWI AND ARE DRIFTING SLOWLY TO THE EAST-NORTHEAST...GENERALLY AWAY FROM THE TERMINALS. SOME ADDITIONAL SHOWERS MAY DEVELOP IN THE NEXT COUPLE HOURS...BUT THE IMPACTS OF THE SHOWERS SHOULD BE LIMITED AND VFR CONDITIONS SHOULD PREVAIL. AN UPPER LEVEL RIDGE WILL BRIEFLY BUILD OVER THE REGION TODAY AND MAY LIMIT STORM COVERAGE MORE SO THAN IN PRIOR DAYS. AS SUCH...WILL NOT MENTION THUNDER IN THE CURRENT TAF...BUT CHANCES WILL BE GREATEST AT KGSO AND KINT ONCE AGAIN. STRATUS IS POSSIBLE AGAIN TONIGHT...AND CONFIDENCE IS A LITTLE HIGHER THAN IN PAST NIGHTS GIVEN A SLIGHTLY STRONGER WIND JUST ABOVE THE SURFACE AND A BETTER AGREEMENT ON AMONG MODELS...WITH THE BEST CHANCE FROM KFAY TO KRWI. OUTLOOK...A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY...WITH SOME PREFRONTAL CONVECTION POSSIBLE THURSDAY AFTERNOON. THE FRONT WILL THEN PUSH THROUGH THE AREA THURSDAY NIGHT AND SETTLE SOUTH OF THE AREA ON FRIDAY. IF THIS FRONT DOES PUSH ALL THE WAY THROUGH THE AREA...THEN VFR CONDITIONS WILL BE MUCH MORE LIKELY FOR THE UPCOMING WEEKEND. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...22 LONG TERM...26 AVIATION...22
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1131 AM EDT WED JUL 29 2015 .SYNOPSIS... SUMMERTIME HEAT AND HUMIDITY WILL BE THE MAIN WEATHER STORY TODAY ACROSS CENTRAL PENNSYLVANIA. A COLD FRONT WILL MOVE THROUGH THE KEYSTONE STATE ON THURSDAY...WITH ISOLATED SEVERE THUNDERSTORMS POSSIBLE NEAR THE LOWER SUSQUEHANNA VALLEY. FRIDAY WILL BE SEASONABLY WARM AND DRY WITH MUCH LOWER HUMIDITY TO CLOSE OUT JULY 2015. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG NEARLY COMPLETELY BURNED OFF THIS MORNING. FORECAST ON TRACK WITH A HAZY HOT AND HUMID AFTERNOON ACROSS THE AREA. PRETTY DECENT CHANCE THAT STATE COLLEGE WILL HAVE ITS FIRST 90 DEGREE DAY IN 2 YEARS. HRRR SHOWS WIDELY SCATTERED CONVECTION FIRING OFF ON SOUTHERN CWA RIDGES AND DRIFTING SLOWLY EASTWARD. MID LEVEL TEMPS STILL WARM AND THIS WILL LIMIT WIDESPREAD CONVECTION. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... SHORT TERM MODEL DATA OVER THE LAST TWO CYCLES ARE A TAD FASTER WITH THE EWD MVMT OF THE SFC COLD FRONT FCST TO SWEEP ACROSS SERN CANADA AND THE NORTHEAST/MID ATLANTIC STATES ON D2/THURSDAY. WEAK HEIGHT FALLS ARE STILL EXPECTED TO OVERSPREAD CENTRAL PA ON THE SRN PERIPHERY OF STRONG UPPER TROUGH AMPLIFYING OVER ERN CANADA. EARLY-DAY CLOUD COVER W/ISOLD SHOWERS ALONG EWD-ADVANCING COLD FRONT SHOULD EXTEND FURTHER INTO THE INTERIOR CENTRAL ZONES. WHILE THE BEST LARGE SCALE FORCING FOR ASCENT/0-6KM SHEAR AND MID-LEVEL LAPSE RATES WILL BE DISPLACED FURTHER TO THE NORTH OVER THE NEW ENGLAND STATES...STILL THINK THAT THE SERN 1/3 TO 1/4 OF THE CWA STANDS AT BETTER THAN 50/50 ODDS TO SEE A SCT TSTMS AHEAD OF THE COLD FRONT...A FEW OF WHICH MAY BE STRONG TO MARGINALLY SEVERE WITH LOCALIZED WIND DAMAGE POTENTIAL GIVEN STEEP LOW-LEVEL LAPSE RATES AND DCAPE VALUES IN EXCESS OF 1000 J/KG. PREVIOUS SPC D3 MRGL RISK HAS BEEN SHIFTED SOUTH/EAST NOW COVERING ONLY PORTIONS OF THE LWR SUSQ VLY. DRIER LOW PWAT AIR QUICKLY SPREADS INTO THE AREA BEHIND THE FROPA AND ENDS THE PCPN RISK IN THE FAR SE COUNTIES BY LATE THURSDAY EVE/00Z FRI. && .LONG TERM /FRIDAY THROUGH TUESDAY/... LITTLE CHANGE IS ANTICIPATED IN THE LARGE SCALE FLOW PATTERN ACROSS THE EASTERN U.S. THROUGH THE MEDIUM RANGE PERIOD...WITH A MEAN RIDGE IN THE WEST AND BROAD TROUGH EXTENDING SWD FROM HUDSON BAY VORTEX AND EAST OF THE CONTINENTAL DIVIDE. CONVECTIVE PCPN SHOULD BE RATHER SPARSE AND FOCUSED ALONG WEAKENING NRN STREAM FRONTAL SYSTEMS PROGRESSING SEWD FROM THE GREAT LAKES ABOUT EVERY 1-2 DAYS STARTING ON SATURDAY. CONFIDENCE IN TIMING IS LOW ESPECIALLY INTO EARLY NEXT WEEK GIVEN INCREASING MODEL SPREAD. TEMPERATURES SHOULD COOL BACK TO SEASONAL AVERAGES INTO THE BEGINNING OF AUGUST. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... FOG DISSIPATED AND VFR CONDITIONS THIS AFTERNOON UNDER HIGH PRESSURE. CLOUDS WILL START TO ADVANCE TONIGHT AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. MVFR CIGS AND VSBYS ARE POSSIBLE BEGINNING IN THE SOUTHWEST AND THEN SPREADING EASTWARD AS SHOWERS IN ADVANCE OF THE FRONT MAY NUDGE INTO BFD BEFORE SUNRISE THURSDAY. THE FRONT SHOULD PASS THURSDAY BRINGING DRIER CONDITIONS AND A DECREASE IN THE COVERAGE OF SHOWERS AND THUNDERSTORMS LATE THURSDAY INTO FRIDAY. OUTLOOK... FRI...MAINLY VFR. SAT...MAINLY VFR...PM TSRA POSS W. SUN...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STEINBUGL NEAR TERM...ROSS SHORT TERM...STEINBUGL LONG TERM...STEINBUGL AVIATION...ROSS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1100 AM EDT WED JUL 29 2015 .SYNOPSIS... SUMMERTIME HEAT AND HUMIDITY WILL BE THE MAIN WEATHER STORY TODAY ACROSS CENTRAL PENNSYLVANIA. A COLD FRONT WILL MOVE THROUGH THE KEYSTONE STATE ON THURSDAY...WITH ISOLATED SEVERE THUNDERSTORMS POSSIBLE NEAR THE LOWER SUSQUEHANNA VALLEY. FRIDAY WILL BE SEASONABLY WARM AND DRY WITH MUCH LOWER HUMIDITY TO CLOSE OUT JULY 2015. && .NEAR TERM /THROUGH TONIGHT/... PATCHY FOG NEARLY COMPLETELY BURNED OFF THIS MORNING. FORECAST ON TRACK WITH A HAZY HOT AND HUMID AFTERNOON ACROSS THE AREA. PRETTY DECENT CHANCE THAT STATE COLLEGE WILL HAVE ITS FIRST 90 DEGREE DAY IN 2 YEARS. HRRR SHOWS WIDELY SCATTERED CONVECTION FIRING OFF ON SOUTHERN CWA RIDGES AND DRIFTING SLOWLY EASTWARD. MID LEVEL TEMPS STILL WARM AND THIS WILL LIMIT WIDESPREAD CONVECTION. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... SHORT TERM MODEL DATA OVER THE LAST TWO CYCLES ARE A TAD FASTER WITH THE EWD MVMT OF THE SFC COLD FRONT FCST TO SWEEP ACROSS SERN CANADA AND THE NORTHEAST/MID ATLANTIC STATES ON D2/THURSDAY. WEAK HEIGHT FALLS ARE STILL EXPECTED TO OVERSPREAD CENTRAL PA ON THE SRN PERIPHERY OF STRONG UPPER TROUGH AMPLIFYING OVER ERN CANADA. EARLY-DAY CLOUD COVER W/ISOLD SHOWERS ALONG EWD-ADVANCING COLD FRONT SHOULD EXTEND FURTHER INTO THE INTERIOR CENTRAL ZONES. WHILE THE BEST LARGE SCALE FORCING FOR ASCENT/0-6KM SHEAR AND MID-LEVEL LAPSE RATES WILL BE DISPLACED FURTHER TO THE NORTH OVER THE NEW ENGLAND STATES...STILL THINK THAT THE SERN 1/3 TO 1/4 OF THE CWA STANDS AT BETTER THAN 50/50 ODDS TO SEE A SCT TSTMS AHEAD OF THE COLD FRONT...A FEW OF WHICH MAY BE STRONG TO MARGINALLY SEVERE WITH LOCALIZED WIND DAMAGE POTENTIAL GIVEN STEEP LOW-LEVEL LAPSE RATES AND DCAPE VALUES IN EXCESS OF 1000 J/KG. PREVIOUS SPC D3 MRGL RISK HAS BEEN SHIFTED SOUTH/EAST NOW COVERING ONLY PORTIONS OF THE LWR SUSQ VLY. DRIER LOW PWAT AIR QUICKLY SPREADS INTO THE AREA BEHIND THE FROPA AND ENDS THE PCPN RISK IN THE FAR SE COUNTIES BY LATE THURSDAY EVE/00Z FRI. && .LONG TERM /FRIDAY THROUGH TUESDAY/... LITTLE CHANGE IS ANTICIPATED IN THE LARGE SCALE FLOW PATTERN ACROSS THE EASTERN U.S. THROUGH THE MEDIUM RANGE PERIOD...WITH A MEAN RIDGE IN THE WEST AND BROAD TROUGH EXTENDING SWD FROM HUDSON BAY VORTEX AND EAST OF THE CONTINENTAL DIVIDE. CONVECTIVE PCPN SHOULD BE RATHER SPARSE AND FOCUSED ALONG WEAKENING NRN STREAM FRONTAL SYSTEMS PROGRESSING SEWD FROM THE GREAT LAKES ABOUT EVERY 1-2 DAYS STARTING ON SATURDAY. CONFIDENCE IN TIMING IS LOW ESPECIALLY INTO EARLY NEXT WEEK GIVEN INCREASING MODEL SPREAD. TEMPERATURES SHOULD COOL BACK TO SEASONAL AVERAGES INTO THE BEGINNING OF AUGUST. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... PATCHY FOG CONTINUES TO LINGER AT LNS AND UNV AND WILL SLOWLY DISSIPATE BETWEEN 12Z AND 14Z. AFTER 14Z VFR CONDITIONS WILL DOMINATE THE REST OF THE DAY UNDER HIGH PRESSURE. CLOUDS WILL START TO ADVANCE TONIGHT AHEAD OF A COLD FRONT APPROACHING FROM THE WEST. MVFR CIGS AND VSBYS ARE POSSIBLE BEGINNING IN THE SOUTHWEST AND THEN SPREADING EASTWARD AS SHOWERS IN ADVANCE OF THE FRONT MAY NUDGE INTO BFD BEFORE SUNRISE THURSDAY. THE FRONT SHOULD PASS THURSDAY BRINGING DRIER CONDITIONS AND A DECREASE IN THE COVERAGE OF SHOWERS AND THUNDERSTORMS LATE THURSDAY INTO FRIDAY. OUTLOOK... FRI...MAINLY VFR. SAT...MAINLY VFR...PM TSRA POSS W. SUN...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...STEINBUGL NEAR TERM...ROSS SHORT TERM...STEINBUGL LONG TERM...STEINBUGL AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1026 AM CDT WED JUL 29 2015 .UPDATE... BROKEN/OVERCAST MIDLEVEL ALTOCUMULUS DECK WAS SLOWLY DRIFTING SOUTH THROUGH SOUTHWEST TN AND PORTIONS OF NORTH MS. EVEN WHERE SKIES WERE CLOUDY...HEAT INDICES WERE NEAR 100 AT 10 AM CDT. FOR THE MORNING UPDATE...HAVE TRIMMED RAIN CHANCES BACK TO BELOW MENTIONABLE LEVELS UNDER THE UPPER RIDGE/WEST OF THE TN RIVER VALLEY. HRRR WAS OVERDONE WITH RESPECT TO MORNING STORMS OVER NORTHEAST MS... BUT EVEN IT WAS PREDOMINATELY DRY WEST OF THE MS RIVER THIS AFTERNOON. THE 12Z NAM AND 06Z SHOWED NO QPF OVER ANY OF THE MIDSOUTH TODAY. GIVEN 700MB TEMPS OF 12C TO 13C...THIS SCENARIO ISN/T OUT OF THE QUESTION. TEMPERATURE AND HEAT INDEX FORECAST APPEAR ON TRACK...WITH NO ADJUSTMENTS NEEDED AT MIDMORNING. PWB && .PREV DISCUSSION... /ISSUED 711 AM CDT WED JUL 29 2015/ UPDATE... UPDATED FOR THE 12Z AVIATION DISCUSSION. PREV DISCUSSION... /ISSUED 341 AM CDT WED JUL 29 2015/ DISCUSSION... ONE MORE DAY OF DANGEROUS HEAT AND HUMIDITY IS EXPECTED ON WEDNESDAY WITH RELIEF COMING IN THE FORM OF A COLD FRONT MOVING THROUGH THE MID-SOUTH LATE WEDNESDAY NIGHT/THURSDAY MORNING... CURRENTLY...A VERY WARM NIGHT WAS ONGOING ACROSS THE MID-SOUTH WITH TEMPERATURES NEAR 80 DEGREES AND DEWPOINTS IN THE MID TO UPPER 70S. ALOFT...AN UPPER LEVEL RIDGE WAS ANCHORED ACROSS MUCH OF THE SOUTHERN US. AT THE SURFACE...HIGH PRESSURE WAS IN PLACE ACROSS MUCH OF THE SOUTHEASTERN US WITH A COLD FRONT ORIENTED SW TO NE FROM THE TX PANHANDLE THROUGH NORTHERN MO/SRN WI. EARLIER IN THE EVENING...A SUBSTANTIAL COMPLEX OF THUNDERSTORMS DEVELOPED ACROSS PORTIONS OF MIDDLE TENNESSEE WHICH EXPELLED AN OUTFLOW BOUNDARY SOUTHWEST INTO PORTIONS OF THE TENNESSEE RIVER VALLEY. WHILE SURFACE WINDS ARE VARIABLE...THAT BOUNDARY IS LIKELY STILL PRESENT THROUGH THE REGION BUT BECOMING MORE DIFFUSE WITH TIME. FOR WEDNESDAY...EXCESSIVE HEAT IS STILL FORECAST...HOWEVER THERE ARE A FEW COMPLICATING FACTORS. HI-RES MEMBERS INCLUDING THE NSSL WRF AND THE HRRR DEVELOP THUNDERSTORMS EARLY IN THE DAY AS A WEAK DISTURBANCE DIVES SOUTHEAST AROUND THE PERIPHERY OF THE SURFACE RIDGE. THE AFOREMENTIONED OUTFLOW BOUNDARY MAY SERVE AS A FOCUS FOR THIS DEVELOPMENT BUT THIS SOLUTION IS EXTREMELY UNCERTAIN AT THIS POINT. IF IT WERE TO UNFOLD AS SUCH...PORTIONS OF WEST TENNESSEE ALONG THE TN RIVER MAY NOT REACH HEAT ADVISORY CRITERIA OWING TO CLOUD COVER/PRECIP. AT THIS POINT...DID NOT ADJUST THE ADVISORY GIVEN THE AFOREMENTIONED UNCERTAINTY. BELIEVE THE HI-RES SOLUTIONS TO BE MUCH TOO AGGRESSIVE WITH PRECIP DEVELOPMENT...BUT IT IS WORTH MENTIONING. FURTHER WEST TOWARD THE MS RIVER...EXCESSIVE HEAT WARNINGS REMAIN IN EFFECT ACROSS E AND NE AR/NW MS/W TN WITH HIGH CONFIDENCE IN DANGEROUS HEAT INDICES DEVELOPING FROM MIDDAY THROUGH EARLY EVENING. MANY LOCATIONS WILL EXPERIENCE SEVERAL HOURS OF HEAT INDICES BETWEEN 111 AND 114 DEGREES GIVEN THE EXTREMELY MOIST BOUNDARY LAYER IN PLACE WITH DEWPOINTS IN THE MID AND UPPER 70S AND TEMPERATURES IN THE UPPER 90S. PRECIPITATION IS NOT EXPECTED TO HINDER SOLAR HEATING AND SHOULD HOLD OFF UNTIL THE EVENING HOURS. WEDNESDAY NIGHT...THE FRONTAL BOUNDARY APPROACHES FROM THE NORTH BUT CONSIDERABLE UNCERTAINTY EXISTS WITH RESPECT TO COVERAGE OF SHOWERS AND THUNDERSTORMS. THERE WILL LIKELY BE ISOLATED DEVELOPMENT AFTER 00Z THURSDAY ALONG THE FRONT BUT PLACING THIS DEVELOPMENT IS DIFFICULT AT THIS TIME. FOR NOW...SLIGHT CHANCE TO CHANCE POPS WERE MAINTAINED TO ACCOUNT FOR THIS. BY THURSDAY...THE FRONTAL BOUNDARY WILL CONTINUE TO PUSH SOUTH WITH DRIER AIR ADVECTING INTO THE REGION. NORTHERN MISSISSIPPI MAY STILL NEAR HEAT ADVISORY CRITERIA EARLIER IN THE DAY BUT EVEN THIS SHOULD BE SHORT-LIVED AS CLOUD COVER AND SHOWERS/TSTORMS SHOULD PROVIDE RELIEF DURING THE MID TO LATE AFTERNOON HOURS. BY THURSDAY NIGHT...THE FRONT WILL HAVE CLEARED THE REGION LEAVING A MUCH MORE PLEASANT AIRMASS IN PLACE WITH DEWPOINTS IN THE LOW TO MID 60S AND TEMPERATURES IN THE UPPER 60S TO NEAR 70 THURSDAY NIGHT. THROUGH THE WEEKEND...A SLOW WARMUP IS EXPECTED BUT SEVERAL DAYS OF BEARABLE TEMPERATURES ARE FORECAST WITH LOWER HUMIDITY. THIS PERIOD SHOULD ALSO BE DRY FOR THE ENTIRE REGION. IN THE LONG-TERM...UPPER LEVEL RIDGING STRENGTHENS ACROSS THE DESERT SOUTHWEST WITH A PERSISTENT AREA OF UPPER LEVEL LOW PRESSURE ACROSS THE EAST-CENTRAL CANADIAN PROVINCES. THE MID-SOUTH WILL FALL SOMEWHERE BETWEEN THESE TWO FEATURES WITH WARMING TEMPERATURES ONCE AGAIN. A SLOW INCREASE IN HEIGHTS SUGGESTS THAT ANOTHER WARM TO HOT PERIOD MAY DEVELOP BUT IT IS TOO SOON TO TELL HOW HOT...BUT IT IS WORTH WATCHING. TVT .AVIATION... 12Z TAF CYCLE VFR CONDITIONS SHOULD PREVAIL THROUGH THE PERIOD. THERE SHOULD BE A FEW SHOWERS AND THUNDERSTORMS ACROSS WEST TENNESSEE AND NORTHEAST MISSISSIPPI LATER TODAY. VCTS HAS BEEN INCLUDED FOR BOTH KMKL AND KTUP WITH THIS IN MIND. ALL CONVECTION SHOULD DIMINISH OR COVERAGE SHOULD BECOME TOO LOW TO KEEP ANY MENTION IN TAFS TONIGHT. WINDS SHOULD BE LIGHT WESTERLY AT 7 KTS OR LESS BECOMING LIGHT NORTHEASTERLY BEHIND A FRONTAL PASSAGE TONIGHT. JLH && .MEG WATCHES/WARNINGS/ADVISORIES... AR...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR CLAY- CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR- MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR DUNKLIN- PEMISCOT. MS...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR COAHOMA- DESOTO-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA. HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-ITAWAMBA-LAFAYETTE-LEE MS-MONROE-PONTOTOC- PRENTISS-TIPPAH-TISHOMINGO-UNION-YALOBUSHA. TN...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR DYER- FAYETTE-LAKE-LAUDERDALE-OBION-SHELBY-TIPTON. HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BENTON TN-CARROLL- CHESTER-CROCKETT-DECATUR-GIBSON-HARDEMAN-HARDIN-HAYWOOD- HENDERSON-HENRY-MADISON-MCNAIRY-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
711 AM CDT WED JUL 29 2015 .UPDATE... UPDATED FOR THE 12Z AVIATION DISCUSSION. && .PREV DISCUSSION... /ISSUED 341 AM CDT WED JUL 29 2015/ DISCUSSION... ONE MORE DAY OF DANGEROUS HEAT AND HUMIDITY IS EXPECTED ON WEDNESDAY WITH RELIEF COMING IN THE FORM OF A COLD FRONT MOVING THROUGH THE MID-SOUTH LATE WEDNESDAY NIGHT/THURSDAY MORNING... CURRENTLY...A VERY WARM NIGHT WAS ONGOING ACROSS THE MID-SOUTH WITH TEMPERATURES NEAR 80 DEGREES AND DEWPOINTS IN THE MID TO UPPER 70S. ALOFT...AN UPPER LEVEL RIDGE WAS ANCHORED ACROSS MUCH OF THE SOUTHERN US. AT THE SURFACE...HIGH PRESSURE WAS IN PLACE ACROSS MUCH OF THE SOUTHEASTERN US WITH A COLD FRONT ORIENTED SW TO NE FROM THE TX PANHANDLE THROUGH NORTHERN MO/SRN WI. EARLIER IN THE EVENING...A SUBSTANTIAL COMPLEX OF THUNDERSTORMS DEVELOPED ACROSS PORTIONS OF MIDDLE TENNESSEE WHICH EXPELLED AN OUTFLOW BOUNDARY SOUTHWEST INTO PORTIONS OF THE TENNESSEE RIVER VALLEY. WHILE SURFACE WINDS ARE VARIABLE...THAT BOUNDARY IS LIKELY STILL PRESENT THROUGH THE REGION BUT BECOMING MORE DIFFUSE WITH TIME. FOR WEDNESDAY...EXCESSIVE HEAT IS STILL FORECAST...HOWEVER THERE ARE A FEW COMPLICATING FACTORS. HI-RES MEMBERS INCLUDING THE NSSL WRF AND THE HRRR DEVELOP THUNDERSTORMS EARLY IN THE DAY AS A WEAK DISTURBANCE DIVES SOUTHEAST AROUND THE PERIPHERY OF THE SURFACE RIDGE. THE AFOREMENTIONED OUTFLOW BOUNDARY MAY SERVE AS A FOCUS FOR THIS DEVELOPMENT BUT THIS SOLUTION IS EXTREMELY UNCERTAIN AT THIS POINT. IF IT WERE TO UNFOLD AS SUCH...PORTIONS OF WEST TENNESSEE ALONG THE TN RIVER MAY NOT REACH HEAT ADVISORY CRITERIA OWING TO CLOUD COVER/PRECIP. AT THIS POINT...DID NOT ADJUST THE ADVISORY GIVEN THE AFOREMENTIONED UNCERTAINTY. BELIEVE THE HI-RES SOLUTIONS TO BE MUCH TOO AGGRESSIVE WITH PRECIP DEVELOPMENT...BUT IT IS WORTH MENTIONING. FURTHER WEST TOWARD THE MS RIVER...EXCESSIVE HEAT WARNINGS REMAIN IN EFFECT ACROSS E AND NE AR/NW MS/W TN WITH HIGH CONFIDENCE IN DANGEROUS HEAT INDICES DEVELOPING FROM MIDDAY THROUGH EARLY EVENING. MANY LOCATIONS WILL EXPERIENCE SEVERAL HOURS OF HEAT INDICES BETWEEN 111 AND 114 DEGREES GIVEN THE EXTREMELY MOIST BOUNDARY LAYER IN PLACE WITH DEWPOINTS IN THE MID AND UPPER 70S AND TEMPERATURES IN THE UPPER 90S. PRECIPITATION IS NOT EXPECTED TO HINDER SOLAR HEATING AND SHOULD HOLD OFF UNTIL THE EVENING HOURS. WEDNESDAY NIGHT...THE FRONTAL BOUNDARY APPROACHES FROM THE NORTH BUT CONSIDERABLE UNCERTAINTY EXISTS WITH RESPECT TO COVERAGE OF SHOWERS AND THUNDERSTORMS. THERE WILL LIKELY BE ISOLATED DEVELOPMENT AFTER 00Z THURSDAY ALONG THE FRONT BUT PLACING THIS DEVELOPMENT IS DIFFICULT AT THIS TIME. FOR NOW...SLIGHT CHANCE TO CHANCE POPS WERE MAINTAINED TO ACCOUNT FOR THIS. BY THURSDAY...THE FRONTAL BOUNDARY WILL CONTINUE TO PUSH SOUTH WITH DRIER AIR ADVECTING INTO THE REGION. NORTHERN MISSISSIPPI MAY STILL NEAR HEAT ADVISORY CRITERIA EARLIER IN THE DAY BUT EVEN THIS SHOULD BE SHORT-LIVED AS CLOUD COVER AND SHOWERS/TSTORMS SHOULD PROVIDE RELIEF DURING THE MID TO LATE AFTERNOON HOURS. BY THURSDAY NIGHT...THE FRONT WILL HAVE CLEARED THE REGION LEAVING A MUCH MORE PLEASANT AIRMASS IN PLACE WITH DEWPOINTS IN THE LOW TO MID 60S AND TEMPERATURES IN THE UPPER 60S TO NEAR 70 THURSDAY NIGHT. THROUGH THE WEEKEND...A SLOW WARMUP IS EXPECTED BUT SEVERAL DAYS OF BEARABLE TEMPERATURES ARE FORECAST WITH LOWER HUMIDITY. THIS PERIOD SHOULD ALSO BE DRY FOR THE ENTIRE REGION. IN THE LONG-TERM...UPPER LEVEL RIDGING STRENGTHENS ACROSS THE DESERT SOUTHWEST WITH A PERSISTENT AREA OF UPPER LEVEL LOW PRESSURE ACROSS THE EAST-CENTRAL CANADIAN PROVINCES. THE MID-SOUTH WILL FALL SOMEWHERE BETWEEN THESE TWO FEATURES WITH WARMING TEMPERATURES ONCE AGAIN. A SLOW INCREASE IN HEIGHTS SUGGESTS THAT ANOTHER WARM TO HOT PERIOD MAY DEVELOP BUT IT IS TOO SOON TO TELL HOW HOT...BUT IT IS WORTH WATCHING. TVT && .AVIATION... 12Z TAF CYCLE VFR CONDITIONS SHOULD PREVAIL THROUGH THE PERIOD. THERE SHOULD BE A FEW SHOWERS AND THUNDERSTORMS ACROSS WEST TENNESSEE AND NORTHEAST MISSISSIPPI LATER TODAY. VCTS HAS BEEN INCLUDED FOR BOTH KMKL AND KTUP WITH THIS IN MIND. ALL CONVECTION SHOULD DIMINISH OR COVERAGE SHOULD BECOME TOO LOW TO KEEP ANY MENTION IN TAFS TONIGHT. WINDS SHOULD BE LIGHT WESTERLY AT 7 KTS OR LESS BECOMING LIGHT NORTHEASTERLY BEHIND A FRONTAL PASSAGE TONIGHT. JLH && .MEG WATCHES/WARNINGS/ADVISORIES... AR...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR CLAY- CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR- MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR DUNKLIN- PEMISCOT. MS...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR COAHOMA- DESOTO-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA. HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-ITAWAMBA-LAFAYETTE-LEE MS-MONROE-PONTOTOC- PRENTISS-TIPPAH-TISHOMINGO-UNION-YALOBUSHA. TN...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR DYER- FAYETTE-LAKE-LAUDERDALE-OBION-SHELBY-TIPTON. HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BENTON TN-CARROLL- CHESTER-CROCKETT-DECATUR-GIBSON-HARDEMAN-HARDIN-HAYWOOD- HENDERSON-HENRY-MADISON-MCNAIRY-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
338 PM MST WED JUL 29 2015 .SYNOPSIS...SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED OVER SOUTHERN ARIZONA AND SOUTHEAST CALIFORNIA TONIGHT...INCLUDING THE LOWER DESERTS. LOCALIZED HEAVY RAIN AND STRONG WINDS CAN BE EXPECTED...ESPECIALLY OVER HIGHER TERRAIN. HIGH PRESSURE BUILDING OVER THE REGION WILL THEN GRADUALLY REDUCE RAIN CHANCES FROM THURSDAY ONWARD INTO THE UPCOMING WEEKEND...AND INTO EARLY NEXT WEEK...BUT AT LEAST SLIGHT CHANCES WILL REMAIN OVER SOUTH-CENTRAL ARIZONA. TEMPERATURES WILL TAKE A SLIGHT DIP BELOW NORMAL THURSDAY DUE TO WIDESPREAD CLOUD COVERAGE...BEFORE SLOWING WARMING BACK UP FROM FRIDAY INTO EARLY NEXT WEEK AS THE ATMOSPHERE SLOWLY DRIES OUT. && .DISCUSSION... REST OF TODAY THROUGH THURSDAY... STORM ACTIVITY BUILDING OVER GILA...SOUTHERN YAVAPAI...AND SOUTHEAST ARIZONA ARE ANTICIPATED TO PRODUCE OUTFLOWS WHICH WILL LEAD TO NEW STORM DEVELOPMENT OVER THE LOWER DESERTS. RELATIVELY HIGH POPS FOR THIS EVENING ARE PREDICATED ON THAT. OF NOTE...MODEL CAPE NOT VERY IMPRESSIVE FOR PHOENIX AREA AND LATEST HRRR UNIMPRESSIVE WITH PRECIP/REFLECTIVITIES THERE AS WELL. MODEL CAPE IS BETTER OVER SOUTHEAST CALIFORNIA...LESS SO SOUTHWEST ARIZONA. OF NOTE...HRRR CONTINUES TO SHOW A GOOD DEAL OF ACTIVITY OVER LA PAZ COUNTY...DUE TO INFLUENCE FROM SOUTHERN YAVAPAI STORMS. THE SHORT WAVE MOVING ACROSS THE NORTHERN GULF OF CALIFORNIA AND SOUTHERN PORTIONS OF ARIZONA AND CALIFORNIA HAS BEEN SLOW IN AIDING STORM PRODUCTION WHICH SUGGESTS THAT DYNAMICAL FORCING HAS NOT BEEN OVERLY STRONG. THE MCV OVER SOUTHERN ARIZONA HAS NOT BEEN PARTICULARLY PRODUCTIVE EITHER. HOWEVER...WITH CLOUD COVER THINNING OUT AND A FEW HOURS OF DAYLIGHT LEFT...THE WINDOW OF OPPORTUNITY HAS NOT CLOSED YET. THE STRONGER STORMS WILL BE CAPABLE OF LOCALIZED FLOODING AS WELL AS STRONG ERRATIC WINDS. THURSDAY MAY START OFF LOOKING LIKE TODAY WITH A LOT OF DEBRIS CLOUDS AND SPOTTY SHOWERS AROUND AS MODELS INDICATE AN MCV ORIGINATING FROM SONORA MOVING THROUGH VERY LATE TONIGHT AND THURSDAY MORNING. LATEST SREF ACTUALLY DEPICTS MORE CAPE THURSDAY THAN TODAY. IF WE ARE ACTIVE TONIGHT...THAT WONT BE THE CASE. CONVERSELY...IF WE STAY RELATIVELY QUIET THEN THAT COULD VERY WELL BE THE CASE. AS USUAL THIS TIME OF YEAR...A LOT OF UNCERTAINTY REMAINS. FRIDAY AND BEYOND...ALTHOUGH THERE WILL STILL BE ENOUGH MONSOON MOISTURE TO KEEP UP SOME ACTIVITY DURING THIS PERIOD...A GRADUAL DOWNTREND IN CONVECTIVE ACTIVITY AND A SLOW WARMING TREND APPEARS TO BE IN THE CARDS AS THE MAIN UPPER HIGH CENTER GRADUALLY BUILDS OVERHEAD AND THE ATMOSPHERE SLOWLY DRIES OUT...WITH PWATS FALLING INTO THE 1.30 TO 1.50 RANGE BY EARLY NEXT WEEK. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... STORMS OVER GILA AND SOUTHERN YAVAPAI COUNTIES...AS WELL AS SOUTHEAST ARIZONA...ARE EXPECTED TO PRODUCE OUTFLOW WINDS WHICH WILL EVENTUALLY GENERATE NEW STORMS OVER THE VALLEY FLOOR...MAINLY AFTER 00Z. ENOUGH UNCERTAINTY REMAINS THAT VICINITY THUNDERSTORM PHRASING WAS USED IN THE TAFS AS OPPOSED TO TEMPO OR PREVAILING TSRA. ENOUGH MOISTURE IS AVAILABLE IN THE ATMOSPHERE THAT STORMS WILL BE CAPABLE OF PRODUCING LOCALLY REDUCED VISIBILITY IN HEAVY RAIN. IF STRONG STORMS MANAGE TO FORM OVER PINAL COUNTY...THEN LARGE AREAS OF DUST ARE POSSIBLE BUT PROBABLY ANY BLOWING DUST WILL TEND TO BE PATCHY. LINGERING DEBRIS CLOUDS AND SHOWERS ARE QUITE POSSIBLE THROUGH THE OVERNIGHT HOURS. SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP BY 01Z WITH MOST OF THE ACTIVITY FINISHED BY 07Z. HOWEVER...LINGERING DEBRIS SHOWERS AND CLOUDS POSSIBLE OVERNIGHT. ENOUGH UNCERTAINTY REMAINS AT ANY GIVEN TAF SITE THAT VICINITY THUNDERSTORM PHRASING WAS USED AS OPPOSED TO TEMPO OR PREVAILING TSRA. ENOUGH MOISTURE IS AVAILABLE IN THE ATMOSPHERE THAT STORMS WILL BE CAPABLE OF PRODUCING LOCALLY REDUCED VISIBILITY IN HEAVY RAIN ALONG WITH STRONG WINDS. IF STRONG ENOUGH STORMS MANAGE TO FORM...THEN LARGE AREAS OF DUST ARE POSSIBLE BUT PROBABLY ANY BLOWING DUST WILL TEND TO BE PATCHY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER...SATURDAY THROUGH WEDNESDAY...ATMOSPHERIC MOISTURE WILL DECLINE FROM WEST TO EAST OVER THE WEEKEND. THIS WILL CONFINE STORM CHANCES TO SOUTH-CENTRAL ARIZONA...MAINLY THE HIGHER TERRAIN...THROUGH THE FIRST HALF OF NEXT WEEK. HUMIDITIES WILL BE A BIT LOWER AS WELL WITH MAX TEMPERATURES A BIT ABOVE NORMAL. WINDS WILL FOLLOW FAMILIAR WARM SEASON PATTERNS. && .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...AJ/PERCHA AVIATION...AJ FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS GOODLAND KS
221 PM MDT WED JUL 29 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 221 PM MDT WED JUL 29 2015 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS WEST- NORTHWEST FLOW ACROSS NORTHERN PLAINS WITH BROAD RIDGE ACROSS THE SOUTHERN US AND TROUGH ACROSS THE NORTHERN GREAT LAKES. AT THE SURFACE HIGH PRESSURE EXTEND FROM THE NORTHERN PLAINS ACROSS WESTERLY KANSAS. THIS AFTERNOON-TONIGHT...AXIS OF FAVORABLE LAPSE RATES (AROUND 7C/KM) IS IN THE PROCESS OF SHIFTING EAST WITH WEAK SHORTWAVE TROUGH. AS THIS SHIFTS EAST CHANCE FOR SPRINKLES/LIGHT SHOWERS COMES TO AN END (BY EARLY EVENING). LOW TEMPS TONIGHT WILL BE VERY SIMILAR TO LAST NIGHT WITH NEAR SEASONAL VALUES AROUND 60F...AND SOME COOLER LOCATIONS IN THE MID-UPPER 50S. THURSDAY...H5 RIDGE BEINGS TO AMPLIFY ACROSS WESTERN US RESULTING IN STRENGTHENING OF LEE TROUGH AND INCREASE IN WAA ACROSS EASTERN COLORADO/FAR WESTERN KANSAS. TEMPS WILL APPROACH SEASONAL VALUES IN THE UPPER 80S/NEAR 90 FOR MOST PARTS OF OUR CWA. STEEP MID LEVEL LAPSE RATES AND 400-700 J/KG CAPE AXIS BEGINS TO BUILD BACK OVER THE WESTER CWA...WHICH COULD RESULT IN THUNDERSTORM DEVELOPMENT POSSIBLY AS EARLY AS MID MORNING THURSDAY. BEST SURFACE CONVERGENCE IS WEST OF CWA...SO UNTIL WEAK ENERGY TOWARDS THE CWA FROM THE SW DURING THE AFTERNOON WE PROBABLY WONT SEE ANY ACTIVITY. BEST LIFT IS ALSO SOUTH OF OUR CWA...SO CONFIDENCE IS LOW ON COVERAGE AT THIS POINT. BEST SIGNAL/CHANCES WILL BE ACROSS THE WEST ROUGHLY ALONG KS/CO STATE LINE. WITH WEAK CAPE VALUES SEVERE POTENTIAL IS VERY LOW DESPITE INCREASING EFFECTIVE SHEER LATE THURSDAY AFTERNOON. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 145 PM MDT WED JUL 29 2015 THE LONG TERM FORECAST PERIOD WILL BE DOMINATED BY AN UPPER LEVEL HIGH PRESSURE SYSTEM POSITIONED OVER THE SOUTH CENTRAL CONUS...WHICH WILL BRING THE RETURN OF NEAR NORMAL TEMPERATURES IN THE LOWER TO MID 90S ON FRIDAY. THE UPPER LEVEL RIDGE WILL CONTINUE TO AMPLIFY OVER THE WESTERN THIRD OF THE CONUS ON FRIDAY...WHICH WILL BRING MOSTLY DRY CONDITIONS. HOWEVER...A FRONTAL BOUNDARY WILL BE POSITIONED OVER THE SOUTH/SOUTHWEST CORNER OF THE FORECAST AREA WHICH WILL BRING SOME CHANCES FOR SOME DEVELOPING SHOWERS AND THUNDERSTORMS FOR FRIDAY THROUGH SATURDAY. SEVERE INDICATORS AT THIS TIME LOOK MARGINAL AT BEST...SO SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME. AS UPPER LEVEL RIDGE AMPLIFIES OVER THE WEEKEND WITH A LACK OF A SURFACE FORCING MECHANISM...SO EXPECTING DRY WEATHER FOR THE REST OF THE WEEKEND SATURDAY NIGHT THROUGH SUNDAY. WARM SURFACE SOUTHERLY FLOW WILL CONTINUE TO BRING INCREASED MOISTURE WITH DEW POINTS IN THE MID 60S AND TEMPERATURES IN THE UPPER 80S TO LOWER 90S. THE NEXT CHANCES FOR PRECIPITATION WILL BE TUESDAY AS AN UPPER LEVEL SHORTWAVE TROUGH APPROACHES THE CENTRAL HIGH PLAINS REGION. MODEL FORECASTS DIFFER AS TO THE LOCATION AND TIMING OF THE FEATURE...WITH THE ECMWF BRINGING THE DISTURBANCE IN THE FASTEST STARTING TUESDAY. AT THIS POINT...NOT VERY CONFIDENT THAT SHOWERS AND STORMS WILL DEVELOP CONSIDERING GFS/CANADIAN/DGEX MODELS ALL INDICATE THE RIDGE MAINTAINING STRENGTH OVER THE REGION. TO STAY WITHIN FORECAST COLLABORATION THRESHOLDS...KEPT CHANCES FOR PRECIPITATION IN THE FORECAST...ESPECIALLY CONSIDERING THAT THE ECMWF TENDS TO LATCH ON TO FORECAST PATTERNS SOONER THAN THE OTHER MODELS IN THE LONG TERM PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1116 AM MDT WED JUL 29 2015 VFR CONDITIONS SHOULD PREVAIL AT BOTH KGLD AND KMCK TERMINALS. THERE IS A POSSIBILITY FOR 1500 KFT CIGS AT KGLD AROUND 12Z...HOWEVER MOST GUIDANCE IS TRENDING TOWARDS VFR...AND KGLD MAY BE JUST TO THE NE OF BEST BL MOISTURE AXIS. LIGHT SHOWERS OR VIRGA WILL CONTINUE TO MOVE WITHIN THE VICINITY OF BOTH KGLD AND KMCK THIS AFTERNOON WITH GUSTS NEAR THESE SHOWERS AROUND 20KT POSSIBLE. OTHERWISE WINDS WILL BE LESS THAN 10KT THROUGH THE TAF PERIOD AS HIGH PRESSURE LINGERS OVER THE REGION. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...MK AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
242 PM EDT WED JUL 29 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 418 AM EDT WED JUL 29 2015 FAIRLY IMPRESSIVE SURFACE AND UPPER LOW FOR LATE JULY IS LOCATED JUST TO THE SOUTH OF LAKE WINNIPEG EARLY THIS MORNING...AND IT IS KEEPING MUCH OF ITS ENERGY NEAR THE LOW IN MANITOBA. THIS HAS LED TO A FAIRLY UNEVENTFUL PASSAGE OF THE COLD FRONT DUE TO THE LACK OF ANY UPPER LEVEL SUPPORT/SHORTWAVES MOVING THROUGH THE AREA AND THE MID- LEVEL DRY AIR AND CAPPING SEEN ON RAP ANALYSIS SOUNDINGS. THERE WAS A THUNDERSTORM THAT MOVED NORTHEAST OUT OF NORTHWEST WISCONSIN EARLIER IN THE NIGHT BUT DISSIPATED OVER WESTERN LAKE SUPERIOR. HAVE SEEN SOME LIGHT SHOWER DEVELOPMENT OVER THE WESTERN U.P. OVER THE LAST 1-2HRS AND THEY ARE MOVING NORTHEAST WHILE THE FRONT SHIFTS THEM TO THE EAST. THERE HASN/T BEEN ANY LIGHTNING NOTED WITH THEM THUS FAR...LARGELY DUE TO THEM STRUGGLING TO GET ABOVE THE FREEZING LEVEL (HAVE PEAKED AROUND 15KFT). STILL THINK SOME THUNDER IS POSSIBLE AS THEY ALIGN WITH A THIN AREA OF 500 J/KG OF MUCAPE AHEAD OF THE FRONT AS SEEN ON THE SPC MESOSCALE ANALYSIS PAGE. THE COLD FRONT WILL CONTINUE TO THE EAST THIS MORNING AND EXIT THE AREA BY NOON. WILL CONTINUE TO SHOW SLIGHT CHANCE POPS RIGHT ALONG THE FRONT AS IT MOVES EAST THIS MORNING...BUT DON/T EXPECT ANYTHING MORE THAN AN ISOLATED SHOWER/THUNDERSTORM. HAVE SEEN A FAIRLY SIGNIFICANT DROP IN DEWPOINTS BEHIND THE FRONT...AS KIWD WENT FROM A 72 DEGREE DEWPOINT AT 535Z AND QUICKLY DROPPED TO 64 AT 615Z AND IS NOW AT 57 AT 735Z. BEHIND THE FRONT...THE DRY SLOT SEEN ON WATER VAPOR IMAGERY WILL MOVE THROUGH THE AREA AND LEAD TO AN AREA OF MOSTLY SUNNY START TO THE DAY OVER THE WEST. DO EXPECT THE AREA OF CLOUDS IN NORTHEAST ND AND NORTHWEST MN TO MOVE EAST INTO THE WESTERN CWA THIS AFTERNOON AND BE AIDED BY DIURNAL HEATING TO PRODUCE DIURNAL CU ON THE LEADING EDGE AND AHEAD OF THE CLOUDS INTO THE CENTRAL U.P. OVER THE EAST...AFTER A CLOUDY START TO THE DAY...EXPECT A PERIOD OF MOSTLY SUNNY SKIES AND THEN SOME DIURNAL CU IN AFTERNOON AND LINGERING INTO THE EVENING. HIGHS TODAY WILL BE IN THE UPPER 70S OVER THE WEST AND THE LOW-MID 80S OVER THE CENTRAL AND EAST. THE MAIN HAZARD BEHIND THE FRONT WILL BE THE GUSTY WEST-SOUTHWEST WINDS. THESE WINDS WILL BE AIDED BY THE TIGHT PRESSURE GRADIENT OVER THE NORTHWEST HALF OF THE CWA AND LARGELY OVER NORTHWESTERN LAKE SUPERIOR. HAVE ALREADY SEEN GUSTS TO 20-25KTS IMMEDIATELY BEHIND THE FRONT EARLIER IN THE NIGHT AND CLOSER TO THE LOW WINDS HAVE BEEN GUSTING TO 30-35KTS IN NORTHWEST MINNESOTA. THE AMPLE SUNSHINE THIS MORNING WILL HELP TO MIX INTO THE 25-40KT WINDS AROUND 925MB TO THE SURFACE...WITH THE STRONGEST WINDS OVER THE KEWEENAW PENINSULA. IN THAT AREA...WOULD EXPECT GUSTS TO AROUND 35KTS BY MID AFTERNOON AND THERE COULD BE A BRIEF PERIOD OF GUSTS TO 40KTS BY EARLY EVENING. DON/T THINK THERE WILL BE A LONG ENOUGH PERIOD FOR A WIND ADVISORY FOR THE KEWEENAW PENINSULA (NEED 39KTS)...SO WILL ISSUE AN SPS FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES TO HIGHLIGHT THE WINDY CONDITIONS FOR TODAY. THE REST OF THE U.P. WILL SEE WIND GUSTS OF 20- 30KTS...HIGHEST OVER THE WEST. WITH THE MUCH DRIER AIR MOVING INTO THE AREA...THINK DEWPOINTS WILL MIX OUT INTO THE UPPER 40S TO AROUND 50 OVER THE WEST/CENTRAL TODAY. WHILE TEMPERATURES WILL BE COOLER THAN YESTERDAY...RH VALUES WILL STILL FALL INTO THE 30S. THAT WILL LEAD TO AN ELEVATED RISK OF WILDFIRES ACROSS MUCH OF THE U.P. TODAY. SINCE THE RH VALUES WILL BE ABOVE RED FLAG CRITERIA...THIS SITUATION WOULD FALL UNDER AN RFD PRODUCT DUE TO THE FREQUENT GUSTS OVER 25 MPH. SINCE COORDINATION NEEDS TO BE DONE WITH FIRE WX USERS BEFORE ISSUANCE...WILL PASS ALONG TO DAY SHIFT TO COORDINATE POTENTIAL ISSUANCE. A SECONDARY TROUGH MOVES EAST ACROSS THE AREA TONIGHT. SOME CLOUDS ASSOCIATED WITH IT...LARGELY OVER LAKE SUPERIOR...BUT NOT EXPECTING ANY RAIN. THERE WILL STILL BE STRONG WINDS JUST ABOVE THE SURFACE AGAIN TONIGHT...WHICH WILL HELP TO KEEP THE WINDS FROM DECOUPLING. HAVE KEPT UP GUSTS OVER THE KEWEENAW PENINSULA (TO 20-30KTS) ...ESPECIALLY FOR THE EXPOSED LOCATIONS. OTHERWISE...THE REST OF THE AREA WILL SEE WINDS TURNING WESTERLY WITH GUSTS TO 10-20KTS (HIGHEST NORTH). .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 239 PM EDT WED JUL 29 2015 IMPACTS...WITH LIMITED CHANCES FOR PRECIP...WILL HAVE TO KEEP WATCHING FIRE WEATHER. A LOW PRESSURE SYSTEM WILL HANG OUT OVER HUDSON BAY FROM THU NIGHT THROUGH AT LEAST THE WEEKEND...SENDING SEVERAL WAVES ACROSS THE AREA THROUGH DURING TIME. PREDICTABILITY OF THE WAVES IS POOR AS MODELS STRUGGLE TO CONSISTENTLY RESOLVE THE FEATURES. AVAILABLE MOISTURE IS ALSO ON THE LOW SIDE...LIMITING PRECIP COVERAGE AND AMOUNTS. WILL KEEP SLIGHT CHANCE POPS OVER AT LEAST PORTIONS OF THE AREA EACH PERIOD. TEMPERATURES LOOK TO BE NEAR NORMAL. FRI LOOKS PRETTY DRY WHEN LOOKING AT THE SFC RH DROPPING INTO THE MID TO UPPER 30 PERCENT RANGE. WINDS WILL GUSTS TO 20-25MPH...MAKING FOR SOMEWHAT ELEVATED FIRE WEATHER CONCERNS. MODELS SHOW THE LOW SHIFTING TO THE SE IN THE EARLY TO MIDDLE PART OF NEXT WEEK...BUT HOW MUCH AND HOW FAST IS UNCERTAIN. IT DOES LOOK LIKE BETTER PRECIP CHANCES WILL RESULT FROM THE SHIFT AND SUBSEQUENT COLD FRONTAL PASSAGE...TIMING OF THAT IS ALSO UNCERTAIN...BUT SUN NIGHT INTO MON LOOKS LIKE BEST BET FOR NOW. WIDESPREAD PRECIP STILL MAY NOT OCCUR ALONG THE STRONGER WAVE AND COLD FRONTAL PASSAGE. TEMPS LOOK TO DROP TO BELOW NORMAL VALUES MON THROUGH WED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 144 PM EDT WED JUL 29 2015 GUSTY WEST-SOUTHWEST WINDS ARE EXPECTED AT ALL THREE SITES THIS AFTEROON...WITH THE HIGHEST GUSTS (TO AROUND 35KTS) EXPECTED AT KCMX. THE WINDS WILL DIMINISH SOME AT ALL THREE SITES TONIGHT...BUT STILL EXPECT GUSTS TO 25KTS AT KCMX. VFR CU/SC CIG IS EXPECTED THROUGH THIS AFTERNOON AT IWD/CMX WITH FEW-SCATTERED VFR CLOUDS WITH LINGERING INTO TONIGHT. OTHERWISE...EXPECT MAINLY JUST SCT CU AT SAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 AM EDT WED JUL 29 2015 A STRONG LOW PRESSURE SYSTEM FOR LATE JULY IS LOCATED NEAR LAKE WINNIPEG EARLY THIS MORNING AND IT WILL LIFT NORTHEAST INTO FAR NORTHERN ONTARIO TODAY. MEANWHILE...IT WILL SWEEP A COLD FRONT CURRENTLY OVER CENTRAL LAKE SUPERIOR EAST ACROSS THE REST OF THE LAKE THIS MORNING. BEHIND THE FRONT...SOUTHWEST WINDS WILL INCREASE THROUGH THE MORNING OVER THE WESTERN HALF OF THE LAKE AND PRODUCE GALES TO 35-40KTS. THERE COULD BE A FEW GUSTS IN THE 40-45KT RANGE TOWARDS ISLE ROYALE THIS AFTERNOON. THESE WINDS WILL DECREASE AND SHIFT TO THE WEST THIS EVENING AS THE FIRST IN A SERIES OF TROUGHS MOVE ACROSS LAKE SUPERIOR THROUGH SUNDAY MORNING (ASSOCIATED WITH THE SURFACE LOW SLOWLY DRIFTING OVER HUDSON BAY). THERE IS THE POTENTIAL FOR GALES OUT OF THE WEST-NORTHWEST TONIGHT BEHIND THE SECONDARY TROUGH AS THE PRESSURE GRADIENT REMAINS TIGHT OVER NORTHERN LAKE SUPERIOR. BUT EXPECT THE MARINE LAYER TO BE THE STRONGEST IN THAT AREA WITH THE WATER TEMPERATURES STILL IN THE UPPER 30S AND LOWER 40S. WILL ADD A MENTION OF GALE FORCE GUSTS FOR NOW. THE PRESSURE GRADIENT WILL GRADUALLY DECREASE THROUGH THE REST OF THE WEAK AS ADDITIONAL WEAK SURFACE TROUGHS MOVE SOUTHEAST ACROSS THE LAKE. EXPECT WINDS TO STAY BELOW 25KTS AFTER THURSDAY AND THROUGH THE WEEKEND. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162- 240>242-245>247-263. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ264. GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LSZ243-244. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...TITUS AVIATION...JLB MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 PM EDT WED JUL 29 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 418 AM EDT WED JUL 29 2015 FAIRLY IMPRESSIVE SURFACE AND UPPER LOW FOR LATE JULY IS LOCATED JUST TO THE SOUTH OF LAKE WINNIPEG EARLY THIS MORNING...AND IT IS KEEPING MUCH OF ITS ENERGY NEAR THE LOW IN MANITOBA. THIS HAS LED TO A FAIRLY UNEVENTFUL PASSAGE OF THE COLD FRONT DUE TO THE LACK OF ANY UPPER LEVEL SUPPORT/SHORTWAVES MOVING THROUGH THE AREA AND THE MID- LEVEL DRY AIR AND CAPPING SEEN ON RAP ANALYSIS SOUNDINGS. THERE WAS A THUNDERSTORM THAT MOVED NORTHEAST OUT OF NORTHWEST WISCONSIN EARLIER IN THE NIGHT BUT DISSIPATED OVER WESTERN LAKE SUPERIOR. HAVE SEEN SOME LIGHT SHOWER DEVELOPMENT OVER THE WESTERN U.P. OVER THE LAST 1-2HRS AND THEY ARE MOVING NORTHEAST WHILE THE FRONT SHIFTS THEM TO THE EAST. THERE HASN/T BEEN ANY LIGHTNING NOTED WITH THEM THUS FAR...LARGELY DUE TO THEM STRUGGLING TO GET ABOVE THE FREEZING LEVEL (HAVE PEAKED AROUND 15KFT). STILL THINK SOME THUNDER IS POSSIBLE AS THEY ALIGN WITH A THIN AREA OF 500 J/KG OF MUCAPE AHEAD OF THE FRONT AS SEEN ON THE SPC MESOSCALE ANALYSIS PAGE. THE COLD FRONT WILL CONTINUE TO THE EAST THIS MORNING AND EXIT THE AREA BY NOON. WILL CONTINUE TO SHOW SLIGHT CHANCE POPS RIGHT ALONG THE FRONT AS IT MOVES EAST THIS MORNING...BUT DON/T EXPECT ANYTHING MORE THAN AN ISOLATED SHOWER/THUNDERSTORM. HAVE SEEN A FAIRLY SIGNIFICANT DROP IN DEWPOINTS BEHIND THE FRONT...AS KIWD WENT FROM A 72 DEGREE DEWPOINT AT 535Z AND QUICKLY DROPPED TO 64 AT 615Z AND IS NOW AT 57 AT 735Z. BEHIND THE FRONT...THE DRY SLOT SEEN ON WATER VAPOR IMAGERY WILL MOVE THROUGH THE AREA AND LEAD TO AN AREA OF MOSTLY SUNNY START TO THE DAY OVER THE WEST. DO EXPECT THE AREA OF CLOUDS IN NORTHEAST ND AND NORTHWEST MN TO MOVE EAST INTO THE WESTERN CWA THIS AFTERNOON AND BE AIDED BY DIURNAL HEATING TO PRODUCE DIURNAL CU ON THE LEADING EDGE AND AHEAD OF THE CLOUDS INTO THE CENTRAL U.P. OVER THE EAST...AFTER A CLOUDY START TO THE DAY...EXPECT A PERIOD OF MOSTLY SUNNY SKIES AND THEN SOME DIURNAL CU IN AFTERNOON AND LINGERING INTO THE EVENING. HIGHS TODAY WILL BE IN THE UPPER 70S OVER THE WEST AND THE LOW-MID 80S OVER THE CENTRAL AND EAST. THE MAIN HAZARD BEHIND THE FRONT WILL BE THE GUSTY WEST-SOUTHWEST WINDS. THESE WINDS WILL BE AIDED BY THE TIGHT PRESSURE GRADIENT OVER THE NORTHWEST HALF OF THE CWA AND LARGELY OVER NORTHWESTERN LAKE SUPERIOR. HAVE ALREADY SEEN GUSTS TO 20-25KTS IMMEDIATELY BEHIND THE FRONT EARLIER IN THE NIGHT AND CLOSER TO THE LOW WINDS HAVE BEEN GUSTING TO 30-35KTS IN NORTHWEST MINNESOTA. THE AMPLE SUNSHINE THIS MORNING WILL HELP TO MIX INTO THE 25-40KT WINDS AROUND 925MB TO THE SURFACE...WITH THE STRONGEST WINDS OVER THE KEWEENAW PENINSULA. IN THAT AREA...WOULD EXPECT GUSTS TO AROUND 35KTS BY MID AFTERNOON AND THERE COULD BE A BRIEF PERIOD OF GUSTS TO 40KTS BY EARLY EVENING. DON/T THINK THERE WILL BE A LONG ENOUGH PERIOD FOR A WIND ADVISORY FOR THE KEWEENAW PENINSULA (NEED 39KTS)...SO WILL ISSUE AN SPS FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES TO HIGHLIGHT THE WINDY CONDITIONS FOR TODAY. THE REST OF THE U.P. WILL SEE WIND GUSTS OF 20- 30KTS...HIGHEST OVER THE WEST. WITH THE MUCH DRIER AIR MOVING INTO THE AREA...THINK DEWPOINTS WILL MIX OUT INTO THE UPPER 40S TO AROUND 50 OVER THE WEST/CENTRAL TODAY. WHILE TEMPERATURES WILL BE COOLER THAN YESTERDAY...RH VALUES WILL STILL FALL INTO THE 30S. THAT WILL LEAD TO AN ELEVATED RISK OF WILDFIRES ACROSS MUCH OF THE U.P. TODAY. SINCE THE RH VALUES WILL BE ABOVE RED FLAG CRITERIA...THIS SITUATION WOULD FALL UNDER AN RFD PRODUCT DUE TO THE FREQUENT GUSTS OVER 25 MPH. SINCE COORDINATION NEEDS TO BE DONE WITH FIRE WX USERS BEFORE ISSUANCE...WILL PASS ALONG TO DAY SHIFT TO COORDINATE POTENTIAL ISSUANCE. A SECONDARY TROUGH MOVES EAST ACROSS THE AREA TONIGHT. SOME CLOUDS ASSOCIATED WITH IT...LARGELY OVER LAKE SUPERIOR...BUT NOT EXPECTING ANY RAIN. THERE WILL STILL BE STRONG WINDS JUST ABOVE THE SURFACE AGAIN TONIGHT...WHICH WILL HELP TO KEEP THE WINDS FROM DECOUPLING. HAVE KEPT UP GUSTS OVER THE KEWEENAW PENINSULA (TO 20-30KTS) ...ESPECIALLY FOR THE EXPOSED LOCATIONS. OTHERWISE...THE REST OF THE AREA WILL SEE WINDS TURNING WESTERLY WITH GUSTS TO 10-20KTS (HIGHEST NORTH). .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 455 AM EDT WED JUL 29 2015 THE OVERALL PATTERN AFFECTING THE AREA WILL NOT CHANGE MUCH THROUGH THE LONG TERM AS PERSISTENT CLOSED LOW NEAR HUDSON BAY WILL KEEP A BROAD TROUGH ENTRENCHED OVER MUCH OF ERN CANADA AND A BROAD RIDGE IS ANCHORED OVER THE WRN CONUS. BETWEEN THESE LARGE SCALE FEATURES A NW FLOW WILL DOMINATE THE GREAT LAKES REGION AS A SERIES OF MAINLY WEAK SHORTWAVES PASSING THRU BRING CHCS FOR PERIODIC LIGHT SHOWERS. TIMING OF THESE WEAK SHORTWAVES WILL LIKELY BE POORLY RESOLVED BY MODELS WHICH WILL MAKE FOR A TRICKY FCST IN THE LONG TERM. IT LOOKS LIKE TEMPERATURES WILL BE NEAR NORMAL THROUGH THE WEEKEND AND THEN TREND BELOW NORMAL TOWARD THE BEGINNING HALF OF NEXT WEEK AS A MID- LVL TROUGH BEGINS TO AMPLIFY INTO THE UPPER GREAT LAKES REGION. THU THROUGH FRI...MOST OF MODELS SHOW A WEAK SHORTWAVE MOVING THROUGH THE AREA TOWARD THU EVENING WITH ANOTHER WEAK SHORTWAVE MOVING THROUGH DURING THE DAY ON FRI. WITH SEVERAL OF THE MODELS SHOWING A FEW HUNDRED J/KG OF MLCAPE EACH DAY MAINLY DURING THE AFTERNOON/EVENING HRS WILL PROBABLY NEED TO MAINTAIN SLIGHT CHC POPS EACH DAY FOR ISOLD SHRA/TSRA. WITH LIMITED MOISTURE IN NW FLOW EXPECT ANY PCPN FROM ISOLD CONVECTION TO BE FAIRLY LIGHT. FRI NIGHT AND SAT...ANOTHER SHORTWAVE MOVING THROUGH DURING THIS TIME WILL WARRANT HAVING SLIGHT CHC POPS OVER MAINLY THE NW AND NE CWA INCLUDING LAKE SUPERIOR. TEMPERATURES THU THROUGH SAT WILL BE CLOSER TO NORMAL WITH HIGHS IN THE 70S TO LOWER 80S AND LOWS IN THE 50S TO LOWER 60S. MODELS HAVE TRENDED FARTHER NORTH WITH MORE SIGNIFICANT SHORTWAVE DUE TO MOVE IN SAT NIGHT INTO SUN SO HAVE BACKED OFF TO ONLY SLIGHT CHANCE POPS FOR THAT TIME FRAME. BEST LIFT WITH SHORTWAVE STAYS NORTH AND BETTER INSTABILITY AS INDICATED BY MODELS IS FARTHER SOUTH. TIMING OF SHORTWAVE AND ASSOC COLD FRONT FOR EARLY NEXT WEEK DIFFERS BTWN THE 00Z GFS AND 00Z ECMWF. THE ECMWF IS QUICKER BRINGING SYSTEM THROUGH SUN NIGHT INTO MON WHILE THE GFS DOESN/T BRING SYSTEM THRU UNTIL LATE MON INTO MON NIGHT. THIS SYSTEM MAY HAVE A BETTER CHC OF BRINGING MORE WIDESPREAD...ALTHOUGH LIGHT PCPN...BUT GIVEN UNCERTAINTY IN TIMING AT THIS POINT DON/T HAVE ANYTHING MORE THAN LOW CHC POPS. MODELS ADVERTISE TEMPS COOLING BELOW NORMAL TEMPS BEHIND THE FRONTAL SYSTEM ESPECIALLY BY TUE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 144 PM EDT WED JUL 29 2015 GUSTY WEST-SOUTHWEST WINDS ARE EXPECTED AT ALL THREE SITES THIS AFTEROON...WITH THE HIGHEST GUSTS (TO AROUND 35KTS) EXPECTED AT KCMX. THE WINDS WILL DIMINISH SOME AT ALL THREE SITES TONIGHT...BUT STILL EXPECT GUSTS TO 25KTS AT KCMX. VFR CU/SC CIG IS EXPECTED THROUGH THIS AFTERNOON AT IWD/CMX WITH FEW-SCATTERED VFR CLOUDS WITH LINGERING INTO TONIGHT. OTHERWISE...EXPECT MAINLY JUST SCT CU AT SAW. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 418 AM EDT WED JUL 29 2015 A STRONG LOW PRESSURE SYSTEM FOR LATE JULY IS LOCATED NEAR LAKE WINNIPEG EARLY THIS MORNING AND IT WILL LIFT NORTHEAST INTO FAR NORTHERN ONTARIO TODAY. MEANWHILE...IT WILL SWEEP A COLD FRONT CURRENTLY OVER CENTRAL LAKE SUPERIOR EAST ACROSS THE REST OF THE LAKE THIS MORNING. BEHIND THE FRONT...SOUTHWEST WINDS WILL INCREASE THROUGH THE MORNING OVER THE WESTERN HALF OF THE LAKE AND PRODUCE GALES TO 35-40KTS. THERE COULD BE A FEW GUSTS IN THE 40-45KT RANGE TOWARDS ISLE ROYALE THIS AFTERNOON. THESE WINDS WILL DECREASE AND SHIFT TO THE WEST THIS EVENING AS THE FIRST IN A SERIES OF TROUGHS MOVE ACROSS LAKE SUPERIOR THROUGH SUNDAY MORNING (ASSOCIATED WITH THE SURFACE LOW SLOWLY DRIFTING OVER HUDSON BAY). THERE IS THE POTENTIAL FOR GALES OUT OF THE WEST-NORTHWEST TONIGHT BEHIND THE SECONDARY TROUGH AS THE PRESSURE GRADIENT REMAINS TIGHT OVER NORTHERN LAKE SUPERIOR. BUT EXPECT THE MARINE LAYER TO BE THE STRONGEST IN THAT AREA WITH THE WATER TEMPERATURES STILL IN THE UPPER 30S AND LOWER 40S. WILL ADD A MENTION OF GALE FORCE GUSTS FOR NOW. THE PRESSURE GRADIENT WILL GRADUALLY DECREASE THROUGH THE REST OF THE WEAK AS ADDITIONAL WEAK SURFACE TROUGHS MOVE SOUTHEAST ACROSS THE LAKE. EXPECT WINDS TO STAY BELOW 25KTS AFTER THURSDAY AND THROUGH THE WEEKEND. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162- 240>242-245>247-263. GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ264. GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LSZ243-244. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...VOSS AVIATION...JLB MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
123 PM EDT WED JUL 29 2015 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 330 AM EDT WED JUL 29 2015 SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A COLD FRONT CROSSES THE REGION. GUSTY WESTERLY WINDS BEHIND THE FRONT WILL USHER IN MORE COMFORTABLE LESS HUMID AIR FOR THE REMAINDER OF THE WEEK ALTHOUGH HIGHS WILL REMAIN IN THE LOWER TO MID 80S. && .UPDATE... ISSUED AT 1044 AM EDT WED JUL 29 2015 DECREASED POPS A BIT BASED ON RADAR TRENDS. A WEAK COLD FRONT IS MOVING ACROSS LAKE MICHIGAN ATTM AND MAY KICK OFF A STORM OR TWO THIS AFTERNOON MAINLY ACROSS THE EASTERN CWA. && .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 ISOLATED SHOWERS HAVE DEVELOPED OVERNIGHT ON THE LEADING EDGE OF THE HIGHER PRECIPITABLE WATER AROUND TWO INCHES MOVING IN FROM THE SOUTHWEST AHEAD OF THE APPROACHING COLD FRONT. SUSPECT COVERAGE OF SHOWERS WILL REMAIN RATHER LIMITED THIS MORNING ACROSS SW LWR MI AS MORE EXPANSIVE AREA OF CONVECTION IMPACTS IOWA AND ILLINOIS. OUR BEST PROSPECT FOR BETTER COVERAGE OF STORMS WILL BE THIS AFTERNOON EAST OF HIGHWAY 131 WHERE SB CAPES NEAR 1500 J/KG ARE PROGGED JUST AHEAD OF THE FRONT. RUC FCST SOUNDINGS EXHIBIT STEEP LOW LEVEL LAPSE RATES WITH SFC TO 3 KM VALUES AROUND 8.5C NEAR JXN. BASED ON THE HIGH PWAT VALUES OF UP TO 2.25 INCHES WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF SOME TORRENTIAL RAINFALL AND POSSIBLY A LOCALIZED WET MICROBURST DAMAGING WIND EVENT. CONVECTION ENDS FROM WEST TO EAST 18Z-22Z WITH THE PASSAGE OF THE FRONT THEN DECREASING CLOUDS AND FALLING SFC DEW PTS EXPECTED. BREEZY CONDITIONS LIKELY THURSDAY ONCE DEEPER MIXING COMMENCES. SOME GUSTS TO 30 MPH WILL BE POSSIBLE IN THE AFTERNOON. HAVE KEPT FRIDAY DRY FOR NOW ALTHOUGH SOME SMALL POPS MAY NEED TO BE ADDED IN LATER FCSTS AS NEXT WEAK SFC FRONT/TROUGH DROPS SOUTH. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 330 AM EDT WED JUL 29 2015 THERE HAS NOT BEEN MUCH CHANGE OVER THE THE PAST FEW DAYS WITH REGARD TO THE EXPECTED PATTERN. WE CONTINUE TO EXPECT LITTLE TO NO RAIN THROUGH SAT...BEFORE AN UNSETTLED WEATHER PATTERN TAKES SHAPE LATER THIS WEEKEND AND INTO NEXT WEEK. WE HAVE CONTINUED WITH A DRY FCST FOR THE FRI NIGHT AND SAT TIME FRAME FOR NOW. WE WILL SEE WHAT IS LEFT OF THE WEAKENING COLD FRONT TRYING TO MOVE THROUGH ON FRI SLIP SE OF THE AREA FRI EVENING. WE CAN NOT RULE OUT A SHOWER DEVELOPING NEAR THIS FRONT...HOWEVER THE CHC IS LOW ENOUGH TO LEAVE OUT OF THE FCST FOR THE TIME BEING. A LACK OF MOISTURE WITH THE FRI FRONT WILL ONLY DIMINISH BY SAT AS THE FRONT MOVES OUT. THERE IS NOT REALLY SIGNIFICANTLY COOLER AIR BEHIND THIS...SO WE CONTINUE TO EXPECT HIGHS AROUND 80. THE CHCS OF RAIN DOES GO UP ON SUN...AND WILL CONTINUE THROUGH THE END OF THE PERIOD ON TUE. THE AREA WILL BE UNDER THE INFLUENCE OF BROAD LONG WAVE TROUGHING CENTERED WELL NORTH IN CANADA. WE WILL SEE THE JET CORE DROP A LITTLE FURTHER SOUTH WITH A TRAIN OF SHORT WAVES HELPING THIS CAUSE. BEING CLOSER TO THE JET...WE WILL HAVE MORE OF AN OPPORTUNITY FOR THE SHORT WAVES TO DIRECTLY IMPACT THE AREA. WE WILL ALSO SEE THE LOW LEVEL FLOW BECOME A LITTLE MORE FAVORABLE TO BRING SUFFICIENT MOISTURE TO THE AREA FOR RAIN. EXACT TIMING OF THE SHORT WAVES WILL BE PROBLEMATIC AS IS USUAL IN A PATTERN LIKE THIS. TEMPERATURES DO NOT LOOK TO BE TOO BAD IN THIS PATTERN. THE UNSEASONABLY COOL AIR WILL REMAIN JUST NORTH OF THE STATE...NORTH OF THE JET CORE. WE WILL SEE AVERAGE TO JUST SLIGHTLY BELOW AVERAGE TEMPS DURING THIS PERIOD FOR OUR AREA. THIS EQUATES TO HIGHS GENERALLY AROUND 80 AND LOWS AROUND 60. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 122 PM EDT WED JUL 29 2015 THERE IS A NARROW BAND OF MVFR CIGS THAT TRAIL THE FRONT...THIS WILL LAST ABOUT 2 HOURS AT ANY ONE STATION. IT HAS ALREADY CLEARED THE MKG TAF SITE AND SHOULD BE CLEARING THE GRR...AZO AND BTL TAF SITES BY 20Z. AHEAD OF THE FRONT CONVECTION IS STARTING TO DEVELOP SO THE LAN AND JXN TAF SITES COULD SEE A THUNDERSTORM PRIOR TO THE PASSAGE OF THE FRONT. THE FRONT SHOULD BE PASSING THROUGH THOSE TAF SITES BY 21Z. TONIGHT SKIES SHOULD BE CLEAR AND WINDS SHOULD BE SOUTHWEST UNDER 10 KNOTS. WINDS WILL INCREASE TO 10 TO 20 KNOTS AND GUSTY THURSDAY AS COOLER AIR AT MID LEVELS MOVES IN. SKIES SHOULD REMAIN CLEAR OR AT LEAST NEARLY SO. && .MARINE... ISSUED AT 330 AM EDT WED JUL 29 2015 CONDITIONS MAY APPROACH SMALL CRAFT ADVISORY CRITERIA LATE TONIGHT AND EARLY THURSDAY DUE TO STRONG WESTERLY FLOW BEHIND THE COLD FRONT. THIS WILL NEED TO BE MONITORED. THIS SITUATION COULD ALSO SUPPORT BEACH HAZARD STATEMENTS ESPECIALLY CONSIDERING THE CURRENT WARM WATER TEMPERATURES AND OVERALL ATTRACTIVE BEACH CONDITIONS SUPPORTIVE OF A HIGH BEACH POPULATION. && .HYDROLOGY... ISSUED AT 1151 AM EDT WED JUL 29 2015 RIVER LEVELS ARE FALLING AND WELL BELOW BANKFULL. THE MAIN CHANCE OF RAIN IN THE NEXT 7 DAYS WOULD BE SUNDAY INTO MONDAY NIGHT. LOCALLY HEAVY RAIN IS POSSIBLE... BUT ONLY PONDING OF WATER IS EXPECTED AWAY FROM THE RIVERS. RIVERS MAY SHOW RISES... BUT SHOULD NOT REACH BANK FULL LEVELS. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...04 SYNOPSIS...MEADE SHORT TERM...MEADE LONG TERM...NJJ AVIATION...WDM HYDROLOGY...63 MARINE...MEADE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
515 PM CDT WED JUL 29 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 331 PM CDT WED JUL 29 2015 "COLD" FRONT IS NOW ALMOST ALL THE WAY THROUGH THE CWFA. TOUGH TO REALLY PICK IT OUT, BUT EVEN FARMINGTON IS REPORTING NORTHWESTERLY WINDS AT THIS HOUR. IT MIGHT BE HUNG UP OVER THE FAR SOUTHERN PORTIONS OF IRON AND REYNOLDS THOUGH. REGARDLESS, WE`RE AT PEAK HEATING RIGHT NOW, AND WE CAN`T SEEM TO CRACK 105 DEGREES ON THE HEAT INDEX, SO WILL BE DROPPING THE EXCESSIVE HEAT WARNING AT 400 PM. WIDELY SCATTERED CONVECTION IS FIRING ALONG THE FRONT, BUT IN SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS, BUT A WEAK CAP HAS DEVELOPED OVER THE AREA ACCORDING TO RAP SOUNDINGS SO I DON`T EXPECT ANY CONVECTION FOR THE REST OF THE DAY AND EVENING HOURS EXCEPT POTENTIALLY IN THE VICINITY OF THE FRONT. ANY STORMS THAT DO AFFECT OUR SOUTHERN CWFA SHOULD BE OUT OF THE AREA OR DISSIPATED BY EARLY EVENING. SLIGHTLY COOLER, BUT SUBSTANTIALLY DRIER AIR WILL FILTER SOUTH OVERNIGHT. STUCK CLOSE TO ENSEMBLE GUIDANCE FOR LOWS TONIGHT WHICH ARE ACTUALLY A LITTLE WARMER THAN OPERATIONAL MET/MAV. WANTED TO BE A LITTLE MORE CONSERVATIVE ON THE "COOL DOWN" SINCE IT IS JULY AFTER ALL, AND THIS ISN`T EXACTLY AN ARCTIC FRONT. CARNEY .LONG TERM: (THURSDAY THROUGH NEXT WEDNESDAY) ISSUED AT 352 PM CDT WED JUL 29 2015 AIR TEMPERATURES BEHIND THE FRONT ON THURSDAY WILL NOT BE THAT MUCH COOLER THAN TODAY. HOWEVER, SHOULD HAVE DEWPOINT TEMPERATURES AS MUCH AS 10-15 DEGREES COOLER SO WHILE IT WILL STILL BE HOT, IT SHOULD FEEL SIGNIFICANTLY LESS BAD. NORTHWEST FLOW ALOFT WILL BRING ANOTHER WEAK COLD FRONT SOUTHEAST THROUGH THE BI-STATE REGION FRIDAY NIGHT. THERE APPEARS TO BE VERY LITTLE IF ANY RETURN FLOW AHEAD OF THE FRONT, SO UNLESS EVAPOTRANSPIRATION CAN RAISE THE DEWPOINTS SIGNIFICANTLY AHEAD OF THE FRONT, IT MIGHT GO THROUGH DRY. HOWEVER, NAM AND GFS ARE PRINTING OUT SOME PRECIP ALONG THE FRONT FRIDAY AFTERNOON AND FRIDAY NIGHT OVER NORTHERN MISSOURI AND WEST CENTRAL ILLINOIS, SO HAVE INTRODUCED SOME SLIGHT CHANCE POPS. AFTER THE FRONT GOES THROUGH IT LOOKS LIKE A DRY AND CONTINUED WARM FORECAST AT LEAST UNTIL MONDAY OR MONDAY NIGHT WHEN ANOTHER COLD FRONT DIPS SOUTH ACROSS THE MIDWEST. THE STRONG HIGH NORTH OF THE FRONT MOVES SOUTHEAST ACROSS THE GREAT LAKES INTO THE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY, BUT WE STAY ON THE PERIPHERY, AND CURRENT MEDIUM RANGE SOLUTIONS KEEP THE FRONT WAVERING BETWEEN CENTRAL MISSOURI AND THE MISSISSIPPI RIVER THROUGH EARLY THURSDAY MORNING. THIS WILL KEEP A CHANCE OF PRECIP IN THE FORECAST INTO THE LATTER PART OF THE WEEK. CARNEY && .AVIATION: (FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING) ISSUED AT 508 PM CDT WED JUL 29 2015 COLD FRONT HAS M0VED THROUGH THE AREA WITH HIGH PRESSURE SETTLING IN FROM THE NORTHERN ROCIKES TO THE LOWER MISSOURI VALLEY. DEW POINTS IN THE 60S WILL BE A WELCOME CHANGE. LIGHT WEST TO NORTHWEST WIND AND VFR CONDITIONS. SPECIFICS FOR KSTL: HIGH PRESSURE MOVING WITH DRIER AIR. LIGHT WEST TO NORTHWEST WIND THROUGH THURSDAY. VFR. JPK && .PRELIMINARY POINT TEMPS/POPS: SAINT LOUIS 71 91 72 91 / 5 0 0 10 QUINCY 65 89 66 89 / 0 0 0 20 COLUMBIA 67 89 67 90 / 0 0 0 10 JEFFERSON CITY 67 91 66 91 / 0 0 0 10 SALEM 67 89 67 89 / 10 0 0 10 FARMINGTON 68 89 65 89 / 10 0 0 5 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
352 PM CDT WED JUL 29 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 331 PM CDT WED JUL 29 2015 "COLD" FRONT IS NOW ALMOST ALL THE WAY THROUGH THE CWFA. TOUGH TO REALLY PICK IT OUT, BUT EVEN FARMINGTON IS REPORTING NORTHWESTERLY WINDS AT THIS HOUR. IT MIGHT BE HUNG UP OVER THE FAR SOUTHERN PORTIONS OF IRON AND REYNOLDS THOUGH. REGARDLESS, WE`RE AT PEAK HEATING RIGHT NOW, AND WE CAN`T SEEM TO CRACK 105 DEGREES ON THE HEAT INDEX, SO WILL BE DROPPING THE EXCESSIVE HEAT WARNING AT 400 PM. WIDELY SCATTERED CONVECTION IS FIRING ALONG THE FRONT, BUT IN SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS, BUT A WEAK CAP HAS DEVELOPED OVER THE AREA ACCORDING TO RAP SOUNDINGS SO I DON`T EXPECT ANY CONVECTION FOR THE REST OF THE DAY AND EVENING HOURS EXCEPT POTENTIALLY IN THE VICINITY OF THE FRONT. ANY STORMS THAT DO AFFECT OUR SOUTHERN CWFA SHOULD BE OUT OF THE AREA OR DISSIPATED BY EARLY EVENING. SLIGHTLY COOLER, BUT SUBSTANTIALLY DRIER AIR WILL FILTER SOUTH OVERNIGHT. STUCK CLOSE TO ENSEMBLE GUIDANCE FOR LOWS TONIGHT WHICH ARE ACTUALLY A LITTLE WARMER THAN OPERATIONAL MET/MAV. WANTED TO BE A LITTLE MORE CONSERVATIVE ON THE "COOL DOWN" SINCE IT IS JULY AFTER ALL, AND THIS ISN`T EXACTLY AN ARCTIC FRONT. CARNEY .LONG TERM: (THURSDAY THROUGH NEXT WEDNESDAY) ISSUED AT 352 PM CDT WED JUL 29 2015 AIR TEMPERATURES BEHIND THE FRONT ON THURSDAY WILL NOT BE THAT MUCH COOLER THAN TODAY. HOWEVER, SHOULD HAVE DEWPOINT TEMPERATURES AS MUCH AS 10-15 DEGREES COOLER SO WHILE IT WILL STILL BE HOT, IT SHOULD FEEL SIGNIFICANTLY LESS BAD. NORTHWEST FLOW ALOFT WILL BRING ANOTHER WEAK COLD FRONT SOUTHEAST THROUGH THE BI-STATE REGION FRIDAY NIGHT. THERE APPEARS TO BE VERY LITTLE IF ANY RETURN FLOW AHEAD OF THE FRONT, SO UNLESS EVAPOTRANSPIRATION CAN RAISE THE DEWPOINTS SIGNIFICANTLY AHEAD OF THE FRONT, IT MIGHT GO THROUGH DRY. HOWEVER, NAM AND GFS ARE PRINTING OUT SOME PRECIP ALONG THE FRONT FRIDAY AFTERNOON AND FRIDAY NIGHT OVER NORTHERN MISSOURI AND WEST CENTRAL ILLINOIS, SO HAVE INTRODUCED SOME SLIGHT CHANCE POPS. AFTER THE FRONT GOES THROUGH IT LOOKS LIKE A DRY AND CONTINUED WARM FORECAST AT LEAST UNTIL MONDAY OR MONDAY NIGHT WHEN ANOTHER COLD FRONT DIPS SOUTH ACROSS THE MIDWEST. THE STRONG HIGH NORTH OF THE FRONT MOVES SOUTHEAST ACROSS THE GREAT LAKES INTO THE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY, BUT WE STAY ON THE PERIPHERY, AND CURRENT MEDIUM RANGE SOLUTIONS KEEP THE FRONT WAVERING BETWEEN CENTRAL MISSOURI AND THE MISSISSIPPI RIVER THROUGH EARLY THURSDAY MORNING. THIS WILL KEEP A CHANCE OF PRECIP IN THE FORECAST INTO THE LATTER PART OF THE WEEK. CARNEY && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1248 PM CDT WED JUL 29 2015 VFR FCST AT THE TERMINALS THRU THE PRD. SFC COLD FRONT IS SOUTH OF ALL THE TERMINAL AS OF EARLY THIS AFTN...ACROSS STHRN IL INTO SE MO. ISLD CONVECTION IS IN THE PROCESS OF DVLPNG ALONG THE BNDRY ACROSS STHRN IL AS OF 18Z...AND EXPECT THIS TO CONTINUE TO DVLP TO THE SW ACROSS SE MO. THIS ACTIVITY IS DVLPNG WITHIN THE BAND OF MVFR CIGS THAT MOVED THRU THE STL METRO TERMINALS. THE SHRAS/TSTMS WILL CONTINUE TO PUSH SE ALONG WITH THE BNDRY. BEHIND THE FRONT...WINDS HAVE TURNED TO THE NORTH FILTERING IN DRIER AIR. WINDS WILL GRADUALLY BECOME W/WNW BY THU MRNG. SPECIFICS FOR KSTL: VFR FCST THRU THE PRD WITH N WIND THIS AFTN BCMNG W/WNW BY THRU MRNG. THE THREAT OF PRECIP IS FCST TO REMAIN SOUTH OF THE TERMINAL THIS AFTN. 2% && .PRELIMINARY POINT TEMPS/POPS: SAINT LOUIS 71 91 72 91 / 5 0 0 10 QUINCY 65 89 66 89 / 0 0 0 20 COLUMBIA 67 89 67 90 / 0 0 0 10 JEFFERSON CITY 67 91 66 91 / 0 0 0 10 SALEM 67 89 67 89 / 10 0 0 10 FARMINGTON 68 89 65 89 / 10 0 0 5 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
332 PM CDT WED JUL 29 2015 .SHORT TERM: (THROUGH LATE TONIGHT) ISSUED AT 331 PM CDT WED JUL 29 2015 "COLD" FRONT IS NOW ALMOST ALL THE WAY THROUGH THE CWFA. TOUGH TO REALLY PICK IT OUT, BUT EVEN FARMINGTON IS REPORTING NORTHWESTERLY WINDS AT THIS HOUR. IT MIGHT BE HUNG UP OVER THE FAR SOUTHERN PORTIONS OF IRON AND REYNOLDS THOUGH. REGARDLESS, WE`RE AT PEAK HEATING RIGHT NOW, AND WE CAN`T SEEM TO CRACK 105 DEGREES ON THE HEAT INDEX, SO WILL BE DROPPING THE EXCESSIVE HEAT WARNING AT 400 PM. WIDELY SCATTERED CONVECTION IS FIRING ALONG THE FRONT, BUT IN SOUTHEAST MISSOURI AND SOUTHERN ILLINOIS, BUT A WEAK CAP HAS DEVELOPED OVER THE AREA ACCORDING TO RAP SOUNDINGS SO I DON`T EXPECT ANY CONVECTION FOR THE REST OF THE DAY AND EVENING HOURS EXCEPT POTENTIALLY IN THE VICINITY OF THE FRONT. ANY STORMS THAT DO AFFECT OUR SOUTHERN CWFA SHOULD BE OUT OF THE AREA OR DISSIPATED BY EARLY EVENING. SLIGHTLY COOLER, BUT SUBSTANTIALLY DRIER AIR WILL FILTER SOUTH OVERNIGHT. STUCK CLOSE TO ENSEMBLE GUIDANCE FOR LOWS TONIGHT WHICH ARE ACTUALLY A LITTLE WARMER THAN OPERATIONAL MET/MAV. WANTED TO BE A LITTLE MORE CONSERVATIVE ON THE "COOL DOWN" SINCE IT IS JULY AFTER ALL, AND THIS ISN`T EXACTLY AN ARCTIC FRONT. CARNEY .LONG TERM: (TONIGHT THROUGH TUESDAY) ISSUED AT 311 AM CDT WED JUL 29 2015 A TWO-DAY RESPITE FROM THE OPPRESSIVE HEAT/HUMIDITY IS EXPECTED ON THU/FRI. TEMPERATURES SHOULD BE SEASONABLY WARM (UPPER 80S TO LOWER 90S), BUT THE DEW POINTS WILL BE MUCH LOWER THAN THEY HAVE BEEN RECENTLY. THE UPPER AIR PATTERN WILL HAVE TRANSITIONED TO NORTHWEST FLOW ALOFT BY FRIDAY DUE TO THE BUILDING RIDGE ACROSS THE WESTERN CONUS AND A TROUGH OVER THE EASTERN CONUS. MODELS SHOW THAT THIS NW FLOW PATTERN REMAINS UNCHANGED THROUGH EARLY NEXT WEEK. ALTHOUGH THE MODELS CONTINUE TO SHOW HINTS OF A SHORTWAVE OR TWO WHICH COULD SUPPORT CONVECTION (PERHAPS AS EARLY AS SATURDAY NIGHT), CONFIDENCE IN THE TIMING AND PLACEMENT OF THESE FEATURES IS LOW. TEMPERATURES LOOK SEASONABLY WARM IN THE UPPER 80S TO LOWER 90S THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. KANOFSKY && .AVIATION: (FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1248 PM CDT WED JUL 29 2015 VFR FCST AT THE TERMINALS THRU THE PRD. SFC COLD FRONT IS SOUTH OF ALL THE TERMINAL AS OF EARLY THIS AFTN...ACROSS STHRN IL INTO SE MO. ISLD CONVECTION IS IN THE PROCESS OF DVLPNG ALONG THE BNDRY ACROSS STHRN IL AS OF 18Z...AND EXPECT THIS TO CONTINUE TO DVLP TO THE SW ACROSS SE MO. THIS ACTIVITY IS DVLPNG WITHIN THE BAND OF MVFR CIGS THAT MOVED THRU THE STL METRO TERMINALS. THE SHRAS/TSTMS WILL CONTINUE TO PUSH SE ALONG WITH THE BNDRY. BEHIND THE FRONT...WINDS HAVE TURNED TO THE NORTH FILTERING IN DRIER AIR. WINDS WILL GRADUALLY BECOME W/WNW BY THU MRNG. SPECIFICS FOR KSTL: VFR FCST THRU THE PRD WITH N WIND THIS AFTN BCMNG W/WNW BY THRU MRNG. THE THREAT OF PRECIP IS FCST TO REMAIN SOUTH OF THE TERMINAL THIS AFTN. 2% && .PRELIMINARY POINT TEMPS/POPS: SAINT LOUIS 71 91 72 91 / 5 0 0 10 QUINCY 65 89 66 89 / 0 0 0 20 COLUMBIA 67 89 67 90 / 0 0 0 10 JEFFERSON CITY 67 91 66 91 / 0 0 0 10 SALEM 67 89 67 89 / 10 0 0 10 FARMINGTON 68 89 65 89 / 10 0 0 5 && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1211 PM CDT WED JUL 29 2015 .UPDATE: ISSUED AT 1159 AM CDT WED JUL 29 2015 EXCESSIVE HEAT WARNING WILL BE CANCELLED SHORTLY FOR A GOOD CHUNK OF THE AREA. CLOUDS AND AND LOWER DEWPOINTS ARE FILTERING IN BEHIND THE FRONT AND IT LOOKS LIKE 105 HEAT INDEX VALUES WON`T BE ACHIEVED TODAY. CARNEY && .SHORT TERM: (THROUGH LATE THIS AFTERNOON) ISSUED AT 311 AM CDT WED JUL 29 2015 08Z SURFACE ANALYSIS REVEALS THAT THE EAGERLY-AWAITED COLD FRONT (AND ITS NOTICEABLY LESS HUMID POST-FRONTAL AIR MASS) WAS TANTALIZINGLY CLOSE TO THE LSX CWA EARLY THIS MORNING. AT 08Z, THE FRONT STRETCHED FROM CENTRAL KS THROUGH EXTREME SOUTHEASTERN NEB AND THROUGH CENTRAL IA INTO WESTERN WI. A NOCTURNAL MCS AHEAD OF THE FRONT WAS MAKING STEADY SOUTHWARD PROGRESS BUT VERY SLOW EASTWARD PROGRESS. ADDITIONAL THUNDERSTORMS ARE POSSIBLE WITH THE FRONT TODAY AS IT MOVES INTO A MOIST AND UNSTABLE AIR MASS DURING THE AFTERNOON HOURS, AND THE OUTFLOW BOUNDARY MAY ALSO SERVE AS A TRIGGER FOR AFTN SH/TS. UNTIL THE COLD FRONT ARRIVES, THERE WILL BE VERY LITTLE CHANGE IN THE SOUPY AIR MASS STILL IN PLACE ACROSS THE REGION. THE TIMING OF THE COLD FRONT IS SUCH THAT ROUGHLY THE SOUTHERN TO SOUTHEASTERN HALF OF THE CWA SHOULD SEE ANOTHER DAY OF HOT/HUMID CONDITIONS, ALBEIT NOT AS OPPRESSIVE AS YESTERDAY. HEAT INDEX VALUES SHOULD BE CLOSER TO 105-109 IN THE WORST AREAS TODAY COMPARED TO THE HEAT INDICES OF 110-117 WHICH WERE OBSERVED YESTERDAY. DESPITE THE SLIGHTLY LOWER HEAT INDEX VALUES WHICH ARE EXPECTED TODAY, THE EXCESSIVE HEAT WARNING STILL LOOKS APPROPRIATE BECAUSE IT IS THE CUMULATIVE EXPOSURE TO EXCESSIVE HEAT WHICH NEGATIVELY AFFECTS THE HUMAN BODY, AND TODAY WILL BE THE THIRD OR FOURTH DAY OF SUCH CONDITIONS FOR SOME AREAS. KANOFSKY .LONG TERM: (TONIGHT THROUGH TUESDAY) ISSUED AT 311 AM CDT WED JUL 29 2015 A TWO-DAY RESPITE FROM THE OPPRESSIVE HEAT/HUMIDITY IS EXPECTED ON THU/FRI. TEMPERATURES SHOULD BE SEASONABLY WARM (UPPER 80S TO LOWER 90S), BUT THE DEW POINTS WILL BE MUCH LOWER THAN THEY HAVE BEEN RECENTLY. THE UPPER AIR PATTERN WILL HAVE TRANSITIONED TO NORTHWEST FLOW ALOFT BY FRIDAY DUE TO THE BUILDING RIDGE ACROSS THE WESTERN CONUS AND A TROUGH OVER THE EASTERN CONUS. MODELS SHOW THAT THIS NW FLOW PATTERN REMAINS UNCHANGED THROUGH EARLY NEXT WEEK. ALTHOUGH THE MODELS CONTINUE TO SHOW HINTS OF A SHORTWAVE OR TWO WHICH COULD SUPPORT CONVECTION (PERHAPS AS EARLY AS SATURDAY NIGHT), CONFIDENCE IN THE TIMING AND PLACEMENT OF THESE FEATURES IS LOW. TEMPERATURES LOOK SEASONABLY WARM IN THE UPPER 80S TO LOWER 90S THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. KANOFSKY && .AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING) ISSUED AT 638 AM CDT WED JUL 29 2015 LARGE CONVECTIVE COMPLEX THAT BLANKETED MOST OF S IA AND N MO LATE YESTERDAY EVENING BECAME OUTFLOW DOMINATED SHORTLY AFTER 05Z...WITH MAIN ELEMENTS DEVELOPING/PROPAGATING SSW WHILE E EDGE REMAINED Q-STATIONARY BETWEEN KIRK-KUIN. IN THE SHORT TERM...E EDGE OF THIS DYING PRECIP AREA MAY CLIP KUIN OVER THE NEXT HOUR OR SO, WHILE DRY WEATHER WILL PREVAIL ELSEWHERE. VFR CONDITIONS ARE ANTICIPATED...WITH CLOUDS AOA 4KFT. CURRENT SURFACE ANALYSIS AND LATEST RAP GUIDANCE SUGGESTS TWO BOUNDARIES THAT COULD PROVIDE FOCUS FOR AFTERNOON CONVECTION...THE FIRST IS THE OUTFLOW FROM THE EARLY MORNING CONVECTION WHICH APPEARS TO BE PUSHING THROUGH STL AREA ATTM. THE SECOND BOUNDARY WILL BE THE ACTUAL SYNOPTIC FRONT. ITS CURRENT LOCATION IS BEING MASKED BY MESOSCALE IMPACTS OF OVERNIGHT CONVECTION BUT IT APPEARS TO BE OVER S CENTRAL/SE IA...AND RAP SUGGESTS IT WILL BE WITH FRONT NEAR THE STL METRO BY MIDDAY. CONVERGENCE WILL BE FAIRLY WEAK BUT THERE SHOULD CERTAINLY BE ENOUGH INSTABILITY TO CARRY CURRENT VCTS AT STL METRO TAF SITES IN THE EARLY AFTERNOON. HOWEVER...HAVE DROPPED MENTION OF VCTS AT KCOU SINCE CONVERGENCE ALONG SYNOPTIC FRONT SHOULD BE SOUTH OF THAT AREA. PREVAILING CONDITIONS ACROSS THE AREA FOR THE AFTERNOON HOURS SHOULD BE SCT- BKN CU 4-5KFT (WITH GREATEST CLOUD COVER NEAR/SOUTH OF COLD FRONT)...WITH THIS CU FIELD QUICKLY DISSIPATING DURING THE EARLY EVENING WITH LOSS OF HEATING AND AS THE DRIER POST-FRONTAL AIR ADVECTS INTO THE AREA. SPECIFICS FOR KSTL: SCATTERED CLOUDS AOA 4KFT ARE EXPECTED THIS MORNING...WITH CU FIELD AOA 4KFT BECOMING SCT-BKN BY LATE MORNING AND INTO THE AFTERNOON. HAVE CONTINUED VCTS IN THE 18-21 TIME FRAME AS SYNOPTIC FRONT WILL BE PASSING AT THAT TIME. CU FIELD SHOULD QUICKLY DISSIPATE HEADING INTO THE EARLY EVENING...WITH A FEW CLOUDS AOA 10KFT OVERNIGHT AND INTO EARLY THURSDAY. TRUETT && .LSX WATCHES/WARNINGS/ADVISORIES: MO...EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR IRON MO- MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE. GENEVIEVE MO. IL...EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR MARION IL- RANDOLPH IL-WASHINGTON IL. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
353 PM CDT WED JUL 29 2015 .SHORT TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 249 PM CDT WED JUL 29 2015 FORECAST CONCERNS IN THE VERY SHORT TERM WILL BE ANY LIGHT SPRINKLES IN SOUTHEAST NEBRASKA...THEN TEMPERATURES...AND CHANCE OF THUNDERSTORMS FRIDAY INTO SATURDAY. WATER VAPOR SATELLITE IMAGERY SHOWED THE MAIN SYNOPTIC FEATURE OF INTEREST WAS THE CLOSED LOW PRESSURE CENTER OVER ONTARIO CANADA WITH THE MID LEVEL MOISTURE PLUME FROM THE BAJA OF CALIFORNIA THROUGH THE FOUR CORNERS REGION INTO THE CENTRAL PLAINS AND OHIO RIVER VALLEY. OF NOTE ON THE H3 MAP WAS THE H3 JET OVER THE NORTHERN/CENTRAL PLAINS INTO THE GREAT LAKES. AT H5...THE STRONGEST HEIGHT FALLS WERE ASSOCIATED WITH THE CLOSED LOW IN CANADA AND THESE TRAILED SOUTHWARD INTO THE PLAINS. MID LEVEL MOISTURE WAS NOTED AT H5 AT KLBF ON THEIR 12Z SOUNDING. THE BETTER H7 AND H85 MOISTURE WAS SUPPRESSED TO THE SOUTH ACROSS KANSAS.H85 DEWPOINTS OF 14-16 DEG C FROM NEW MEXICO INTO TX/OK/SOUTHERN KS. THERE IS A POCKET OF WEAK WARM AIR ADVECTION/WEAKENING H85-H7 FRONTOGENESIS WITH PATCHY MID LEVEL CUMULUS AND A FEW SPRINKLES. ALSO HAVE SOME WEAK RIGHT ENTRANCE JET LIFT. HAVE ADDED SOME SPRINKLES WITH THESE FEATURES. MOST OF THE MODELS WERE DRY...HOWEVER THE HRRR AND THE HRRRX DID HINT AT THIS IN THEIR ASSIMILATED REFLECTIVITY FIELDS. SURFACE HIGH PRESSURE PREVAILS FOR THE REST OF TONIGHT INTO THURSDAY. LOWS TONIGHT IN THE UPPER 50S TO LOWER 60S. HIGH THURSDAY SHOULD TOP OUT IN THE UPPER 80S TO LOWER 90S. DEEPER MOISTURE RETURNS THURSDAY NIGHT AND FRIDAY WITH A WEST TO EAST INSTABILITY AXIS DEVELOPING AND MOISTURE POOLING ALONG THIS AXIS. WE ARE IN NORTHWEST LOW ALOFT AND THE FORCING IS WEAK. INSTABILITY DOES INCREASE TO 2000 J/KG THURSDAY NIGHT AND 4000 J/KG FRIDAY. DO MENTION ISOLATED TO SCATTERED THUNDERSTORMS FRIDAY AND SATURDAY WITH WEAK FORCING IN THIS PATTERN. HIGH TEMPERATURES CONTINUE IN THE MID TO UPPER 80S EACH DAY. .LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 249 PM CDT WED JUL 29 2015 THE UNSETTLED PATTERN CONTINUES IN THE EXTENDED AS RIDGE AMPLIFIES TO THE WEST WITH THE MID TROPOSPHERIC TROF TO OUR EAST AND WE REMAIN IN NORTHWEST FLOW ALOFT. THE EC TRIES TO BRING A DEEPER WAVE ACROSS THE ROCKIES INTO THE PLAINS MONDAY NIGHT AND TUESDAY WITH MORE ROBUST PRECIPITATION TUESDAY NIGHT INTO WEDNESDAY. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1206 PM CDT WED JUL 29 2015 A COUPLE STRONGER WIND GUSTS UP TO AROUND 15MPH COULD MIX DOWN INTO KOFK EARLY THIS AFTERNOON...HOWEVER LEAVING GUSTS OUT OF THE TAF FOR NOW AS IT DOES NOT SEEM OVERLY LIKELY AND SHOULD NOT PERSIST VERY LONG. OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...KG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1229 PM CDT WED JUL 29 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 400 AM CDT WED JUL 29 2015 FOR THE MAJORITY OF THE CWA (ESPECIALLY NEB ZONES)...THIS SHOULD BE A PRETTY STRAIGHTFORWARD NEXT 24 HOURS...WITH A CONTINUED EXPECTATION OF DRY CONDITIONS AND SEASONABLY PLEASANT TEMPS/DEWPOINTS...ALTHOUGH IT MAY BE A SOMEWHAT CLOUDIER DAY THAN PREVIOUSLY THOUGHT. HOWEVER...THINGS GET A BIT TRICKIER SOUTHWARD INTO KS ZONES (ESPECIALLY OUR BOTTOM-MOST 3 COUNTIES)...AS THERE ARE SOME MODELS (FOR EXAMPLE THE GFS) SUGGESTING THAT THIS AREA WILL BE BRUSHED BY THE FAR NORTHERN EDGES OF SOMEWHAT BETTER SHOWER/WEAK THUNDERSTORM POTENTIAL THAT SHOULD MAINLY FOCUS JUST SOUTH OF THE CWA...ESPECIALLY TONIGHT. THAT BEING SAID...OTHER MODELS INCLUDING SIMULATED REFLECTIVITY FROM 4KM WRF/ARW RUNS (INCLUDING THE OFTEN-RELIABLE NSSL WRF) ARE MORE SUPPORTIVE OF THESE MEASURABLE RAIN CHANCES REMAINING JUST SOUTH OF THE CWA...ALBEIT A RATHER CLOSE CALL. TO MAKE A LONG STORY SHORTER...CONSIDERED ADDING A FORMAL SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS TO PARTS OF OUR KS COUNTIES FOR MUCH OF THIS TIME FRAME...BUT GIVEN THE MIXED MESSAGES IN THE MODEL WORLD...AND ALSO CONSIDERING THAT WE HAD BEEN CONSISTENTLY ADVERTISING A "DRY" WEDNESDAY-WEDNESDAY NIGHT FORECAST CWA-WIDE THESE PAST FEW DAYS...OPTED TO TAKE A "MIDDLE GROUND" APPROACH FOR NOW BY SIMPLY INSERTING A "SLIGHT CHANCE OF SPRINKLES" INTO OUR FAR SOUTHERN AREAS. THE INTENDED MESSAGE HERE IS THAT ALTHOUGH WE CONTINUE TO DOWNPLAY PRECIP CHANCES...THE SPRINKLE MENTION BETTER IMPLIES THAT CHANCES ARE NOT TRULY "ZERO" EITHER. OBVIOUSLY THE NEXT FEW SHIFTS WILL HAVE TO MONITOR THE LATEST TRENDS JUST IN CASE PRECIP CHANCES (POPS) AND POSSIBLY THUNDERSTORM POTENTIAL MAY NEED BEEFED UP A BIT IN THIS TRICKY SOUTHERN AREA. TAKING A LOOK AT THE HERE AND NOW AS OF 08Z/3AM: WE ARE ALREADY IN THE MIDST OF A "CLOSE CALL" REGARDING SHOWER/THUNDERSTORM CHANCES IN OUR FAR SOUTHERN CWA...AS A FAIRLY CONCENTRATED AXIS OF SHOWERS /NON-SEVERE STORMS EXTENDING FROM NORTHEAST-CENTRAL KS IS JUST BARELY REMAINING OUTSIDE OUR CWA FOR THE MOST PART. THIS CONVECTION IS FOCUSED SLIGHTLY NORTH OF THE SYNOPTIC SURFACE COLD FRONT POSITIONED OVER SOUTHERN AND EAST-CENTRAL KS...AND IS LARGELY TIED TO AN AXIS OF LOW-MID LEVEL CONVERGENCE/FRONTOGENESIS IN THE 850-700MB LAYER. NOT SURPRISINGLY...THE NORTHERN FRINGE OF THIS CONVECTION IS ALIGNED ALMOST PERFECTLY WITH THE NORTHERN FRINGES OF A VERY SLOWLY SOUTHWARD-SINKING ELEVATED INSTABILITY AXIS...WHICH CLEARED THE VAST MAJORITY OF THE CWA BEHIND THE COLD FRONTAL PASSAGE DURING THE PAST 24 HOURS. IN THE BIGGER PICTURE OF THE MID-UPPER LEVELS...WATER VAPOR SATELLITE AND THE LATEST MODEL DATA DEPICT LIMITED LARGE-SCALE FORCING OVER THE CENTRAL PLAINS...AS THE LOCAL REGION IS SANDWICHED BETWEEN ANTICYCLONIC FLOW ASSOCIATED WITH THE SOUTHERN PLAINS SUBTROPICAL HIGH...AND THE SOUTHERN EDGES OF STRONGER WESTERLY FLOW ASSOCIATED WITH THE VIGOROUS CLOSED LOW PRESSURE SYSTEM SLOWLY DEPARTING NORTHEAST ACROSS THE MANITOBA/ONTARIO BORDER AREA. HOWEVER...THERE IS EVIDENCE OF A SUBTLE DISTURBANCE PASSING NORTHEAST THROUGH SOUTHWEST KS ASSOCIATED WITH A CLUSTER OF CONVECTION NEAR DODGE CITY. WHILE 11-3.9 MICRON SATELLITE IMAGERY HAS REVEALED A LARGELY CLEAR NIGHT THUS FAR OVER MUCH OF THE CWA...AT LEAST A THIN VEIL OF HIGH CLOUDS IS INCREASINGLY SPREADING NORTHEAST INTO THE CWA FROM THE SOUTHWEST KS CONVECTION. AT THE SURFACE...THINGS ARE LARGELY PLAYING OUT AS EXPECTED TONIGHT...WITH THE SOUTHEASTERN REACH OF BROAD HIGH PRESSURE CENTERED OVER THE NORTHERN ROCKIES PROVIDING VERY LIGHT/MAINLY NORTHERLY BREEZES TO THE LOCAL AREA. THIS HIGH PRESSURE AXIS...COMBINED WITH THE WELCOMED PRESENCE OF NOTICEABLY DRIER AIR MARKED BY DEWPOINTS MAINLY IN THE 50S...HAS ALLOWED TEMPS TO FALL SLIGHTLY BELOW LATE-JULY NORMALS IN MOST AREAS...AND ULTIMATELY EXPECT OVERNIGHT LOWS TO RANGE FROM MID 50S NORTHWEST...NEAR 60 CENTRAL AND MID-60S SOUTH. NOW LOOKING AHEAD FORECAST-WISE: EARLY THIS MORNING (THROUGH 7AM): OTHER THAN A CONTINUED GRADUAL INCREASE IN HIGH CLOUDS SPREADING IN FROM THE SOUTHWEST...LITTLE CHANGE FROM THE CURRENT SITUATION EXPECTED. GIVEN THAT IT APPEARS THAT THE EXTREME SOUTHERN FRINGES OF THE CWA WILL CONTINUE TO BARELY MISS OUT ON THE CENTRAL-NORTHEAST KS CONVECTION...WILL BE REMOVING THE PREVIOUSLY-EXISTING SLIGHT CHANCE OF SHOWERS/STORMS IN OUR FAR SOUTH FOR THE PRE-DAWN HOURS. TODAY (7AM-7PM): SEE THE OPENING PARAGRAPH ABOVE FOR THE BASIC REASONING BEHIND INTRODUCING SPRINKLE POTENTIAL INTO OUR FAR SOUTHERN CWA IN KS. HOWEVER...BARRING AN UNEXPECTED NORTHWARD SHIFT IN THE ONGOING EARLY MORNING CONVECTION IN CENTRAL KS...PLAN ON MAINTAINING A THUNDERSTORM-FREE FORECAST GOING FORWARD INTO THE OFFICIAL DAYTIME FORECAST PERIOD. AGAIN...FOR THE MAJORITY OF THE CWA (ESSENTIALLY NEB ZONES)...CONFIDENCE IS STILL HIGH ENOUGH IN A DRY DAY TO PRECLUDE EVEN A SPRINKLE MENTION. THAT BEING SAID THOUGH...THE LAST FEW HRRR RUNS ACTUALLY DO TRY TO DROP A FEW SPRINKLES OUT OF AN INCREASING MID LEVEL CLOUD DECK...BUT WILL LARGELY IGNORE THIS FOR NOW WITH VERY LITTLE SUPPORT FROM OTHER MODELS AND GIVEN THAT THIS LIMITED MOISTURE IS LARGELY AT/ABOVE 600MB. IN THE MID-UPPER LEVELS...SEASONABLY STRONG WESTERLY FLOW PERSISTS OVERHEAD...WITH HINTS OF A SUBTLE DISTURBANCE PASSING THROUGH THE CWA...POSSIBLY INCLUDING THE REMNANTS OF THE AFOREMENTIONED SOUTHWEST KS ONE. MEANWHILE...THE NORTHERN EDGES OF THE ELEVATED INSTABILITY AXIS OVER KS SHOULD LARGELY STALL OUT JUST SOUTH OF THE CWA IN A WEST-T0-EAST FASHION. ALTHOUGH DO NOT HAVE A GREAT FEEL FOR CLOUD COVER TODAY...BEEFED UP SKY COVER PERCENTAGES SOLIDLY INTO PARTLY CLOUDY TERRITORY MOST AREAS FOR MOST OF THE DAY...AND THERE COULD EASILY BE PERIODS OF MOSTLY CLOUDY TOO...ESPECIALLY IF THE NAM IS CORRECT IN DEPICTING A FAIRLY WIDESPREAD COVERAGE OF MID-HIGH CLOUDS DEVELOPING IN RESPONSE TO THE AFOREMENTIONED WEAK DISTURBANCE(S) PASSING THROUGH. AT THE SURFACE...BROAD HIGH PRESSURE WILL PASS EASTWARD OVER THE HEART OF THE CWA...PROMOTING NOT ONLY LIGHT BREEZES THAT WILL LARGELY AVERAGE UNDER 10 MPH...BUT ALSO A GRADUALLY VARYING DIRECTION AS MANY PLACES SEE A TRANSITION FROM NORTHERLY TO EASTERLY TO SOUTHERLY BY LATE IN THE DAY. TEMP-WISE...WOULD NOT BE SURPRISED IF INCREASING CLOUDS HOLD THINGS BACK A TOUCH AND DID DROP SOME AREAS (INCLUDING TRI-CITIES) 1-2 DEGREES FROM PREVIOUS FORECAST...BUT OVERALL STILL CALLING FOR MOST OF THE CWA TO TOP OUT IN THE 82-85 RANGE...WHICH COMBINED WITH LIGHT WIND AND DEWPOINTS LARGELY IN THE 50S SHOULD MAKE FOR A VERY COMFORTABLE LATE JULY DAY. TONIGHT (7PM-7AM): AGAIN...SEE OPENING PARAGRAPH FOR FURTHER INSIGHT INTO THE DECISION TO ADD SPRINKLE POSSIBILITY INTO PARTS OF KS ZONES. ALTHOUGH MODEL DISCREPANCY CONTINUES REGARDING NORTHERN KS PRECIP POTENTIAL...ITS WORTH NOTING THAT THE VERY LATEST 06Z NAM HAS BACKED OFF THE NORTHWARD EXTENT OF SHOWER/THUNDERSTORM POTENTIAL...NOW KEEPING OVERNIGHT CONVECTION JUST SOUTH OF THE CWA (MUCH THE SAME PLACEMENT AS THE ONGOING ACTIVITY). IN THE MID-UPPER LEVELS TONIGHT...FLOW OVER THE CWA STARTS TO TURN EVER-SO-SLIGHTLY NORTHWESTERLY...IN RESPONSE TO THE SOUTHERN PLAINS RIDGE STARTING TO RETROGRADE WESTWARD A BIT. WHILE FAIRLY SUBTLE LOW-MID LEVEL LIFT/CONVERGENCE IS EXPECTED TO PROMOTE "SOME" COVERAGE OF SHOWERS/STORMS MAINLY JUST SOUTH OF THE CWA...THE VAST MAJORITY OF THE LOCAL AREA SHOULD REMAIN VOID OF EVEN SPRINKLES...WITH A LIKELY DECREASE IN MID-HIGH LEVEL CLOUDS AS WELL FROM THE DAYTIME...THUS PROMOTING MOSTLY CLEAR SKIES ESPECIALLY NORTH OF THE STATE LINE. AT THE SURFACE...LIGHT BREEZES WILL CONTINUE IN THE PRESENCE OF BROAD HIGH PRESSURE...BUT LIKELY TAKING ON MORE OF A SOUTHERLY AND/OR WESTERLY COMPONENT. ALL IN ALL...LOW TEMPS ACROSS MOST OF THE CWA MAY END UP BEING VERY SIMILAR TO THOSE OBSERVED THIS MORNING...BUT FOR NOW WILL AIM MOST PLACES VERY SLIGHTLY WARMER...WITH MOST OF THE CWA BOTTOMING OUT SOMEWHERE IN THE 58-63 RANGE. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 400 AM CDT WED JUL 29 2015 AFTER A VERY NICE WEDNESDAY WE WILL WARM RIGHT BACK UP INTO THE UPPER 80S TO LOWER 90S FOR THURSDAY THROUGH THE WEEKEND AND INTO NEXT MONDAY...BEFORE PERHAPS ANOTHER COOL DOWN NEXT TUESDAY. WE DO HAVE SEVERAL RAIN CHANCES...BUT CONFIDENCE IN SEEING PRECIPITATION IS NOT THAT HIGH ON ANY GIVEN DAY. MOST LOCATIONS WILL LIKELY END UP DRY THROUGH FRIDAY...BUT WE WILL SEE AT LEAST A FEW MORE CHANCES OF RAIN THEREAFTER. THURSDAY AND FRIDAY...THE HUMIDITY WILL BEGIN TO WORK BACK INTO THE REGION. DEWPOINTS WILL RISE FROM THEIR LOW POINT IN THE LOWER 50S TODAY...TO AROUND 60 ON THURSDAY...AND INTO THE MID 60S BY FRIDAY. THE SFC WIND WILL BE FAIRLY LIGHT...BUT IS EXPECTED TO BECOME GENERALLY SOUTHERLY...WHICH WILL HELP TO WARM THINGS UP A COUPLE DEGREES BACK TO AROUND NORMAL IN THE UPPER 80S TO AROUND 90. THE UPPER RIDGE OVER THE SOUTHERN PLAINS WILL RETROGRADE BACK TO THE WEST AND SET UP OVER THE DESERT SOUTHWEST. IN OUR AREA THERE WILL BE AN AREA OF WEAK SFC CONVERGENCE ACROSS OUR NORTHERN AND EASTERN ZONES FRIDAY AFTERNOON THAT COULD POP A FEW ISOLATED THUNDERSTORMS BASED ON THE 00Z NAM AND 00Z GFS. CONFIDENCE IS LOW AND CONVECTION WOULD LIKELY BE VERY HIT AND MISS WITH MOST FOLKS LIKELY MISSING OUT ON IT. SATURDAY THROUGH MONDAY...NORTHWESTERLY FLOW ALOFT WILL SEND US A FEW SHORTWAVES AND SUBSEQUENT THUNDERSTORM CHANCES. ONE SUCH SHORTWAVE IS EVIDENT IN THE 00Z GFS AND 00Z ECMWF SATURDAY AFTERNOON/EVENING. THEREFORE...WILL THROW SOME CHANCE POPS IN THE FORECAST WITH THE HIGHEST POPS BEING ACROSS NORTHERN AND EASTERN ZONES. OVERALL...AT LEAST THE WAY IT LOOK RIGHT NOW...PRECIPITATION CHANCES WILL STILL BE FAIRLY LOW AT LESS THAN 50/50. WE SHOULD BE IN BETWEEN SHORTWAVES ON SUNDAY SO CONFIDENCE IN DRY WEATHER IS FAIRLY GOOD FOR SUNDAY. THE NEXT SHORTWAVE ENTERS THE PICTURE ON MONDAY BUT FORECAST MODELS DIFFER ON THE SPEED OF THE ASSOCIATED FRONT. GIVEN THE EXPECTATION OF HAVING SOME UPPER LEVEL SUPPORT IN THE GENERAL AREA FROM THIS UPPER WAVE...WILL CALL FOR CHANCE POPS. TEMPERATURES WILL REMAIN NEAR NORMAL DURING THIS STRETCH...OR GENERALLY IN THE UPPER 80S TO LOWER 90S. TUESDAY...CONFIDENCE IS PRETTY LOW THIS FAR OUT GIVEN THE NORTHWESTERLY FLOW REGIME. THEREFORE...WILL STICK WITH THE SUPERBLEND OF ALL MODELS...WHICH GIVES US A SMALL CHANCE OF PRECIPITATION AND SLIGHTLY COOLER TEMPERATURES WITH HIGHS IN THE MID TO UPPER 80S. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1228 PM CDT WED JUL 29 2015 VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...PFANNKUCH LONG TERM...WESELY AVIATION...FAY
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
948 AM PDT WED JUL 29 2015 .SYNOPSIS...MOISTURE WILL SPREAD NORTH INTO THE AREA TODAY INTO TOMORROW ALLOWING FOR SHOWERS AND THUNDERSTORMS TO RETURN TO SOME AREAS MAINLY DURING THE AFTERNOON AND EVENING HOURS. THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL LINGER FROM FRIDAY INTO NEXT MONDAY THEN BEGIN TO DECREASE IN MOST AREAS ON TUESDAY AS DRIER AIR MOVES BACK ON IN. TEMPERATURES WILL REMAIN NEAR NORMAL THROUGH THE WEEKEND WARMING TO SLIGHTLY ABOVE NORMAL EARLY NEXT WEEK. && .UPDATE...MOISTURE POOLED OVER THE LOWER COLORADO RIVER VALLEY YESTERDAY HAS SPREAD AS FAR NORTH AS SOUTHERN NEVADA WITH SURFACE DEWPOINTS INTO THE LOW TO MID 50S UP TO CAL-NEV-ARI AND LAUGHLIN. RADAR IS DETECTING WEAK RETURNS IN PARTS OF SAN BERNARDINO, SRN CLARK AND MOHAVE COUNTIES WITH LITTLE OF THAT REACHING THE GROUND. MADE ONLY MINOR UPDATES TO THE FORECAST TODAY BASED ON 12Z HI-RES AND HRRR OUTPUT. EXPANDED POPS SLIGHTLY FURTHER NORTHWARD IN THE HIGHER TERRAIN OF FAR SOUTHERN CLARK COUNTY. LEFT STORMS OUT OF LAS VEGAS BUT HRRR DOES SHOW THE POTENTIAL FOR OUTFLOW WINDS REACHING THE VALLEY BETWEEN 00Z AND 01Z WHICH BEARS MONITORING. && .AVIATION...FOR MCCARRAN...WINDS WILL FAVOR AN EASTERLY DIRECTION AND BE LESS THAN 8 KTS THROUGH 03Z OR SO THURSDAY THEN TRANSITION TO THE SOUTHWEST. FEW-SCT CLOUDS ABOVE 12K FT THIS AFTERNOON INTO TONIGHT. THERE IS A SLIGHT CHANCE OF A SHRA OR TSRA AFTER 20Z TODAY IN THE DAGGETT AND PEACH SPRINGS APPROACH CORRIDORS THROUGH AROUND 04Z OR SO THURSDAY. LEFT STORMS OUT OF LAS VEGAS BUT HRRR MODEL DOES SHOW THE POTENTIAL FOR OUTFLOW WINDS REACHING THE VALLEY BETWEEN 00Z AND 01Z WHICH BEARS MONITORING. THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...TYPICAL DIURNAL WINDS ARE EXPECTED THROUGH TONIGHT AT ALL TERMINALS. A SLIGHT CHANCE OF THUNDERSTORMS EXISTS MAINLY OVER THE HIGHER TERRAIN IN AREAS SOUTH OF A KDAG-KIGM LINE WITH SCT-BKN CLOUDS AVERAGING AOA 7-12K FEET. LOWER CIGS AND GUSTY WINDS POSSIBLE NEAR STRONGER STORMS. MOSTLY CLEAR NORTH OF A KDAG-KIGM LINE. && .PREV DISCUSSION...256 AM PDT WED JUL 29 2015 .SHORT TERM...TODAY THROUGH FRIDAY NIGHT. AS IS EVIDENT ON SATELLITE AND LOOKING AT OBSERVATIONS THIS MORNING MOISTURE IS MAKING A MOVE ON NORTH. IPW SENSORS SHOW A STEADY CLIMB IN PWAT VALUES SINCE YESTERDAY WITH VALUES MAINLY BETWEEN 0.50 INCH AND 1.00 INCH ACROSS MUCH OF THE AREA AND AS HIGH AS 1.48 INCH AT VIDAL JUNCTION. SURFACE DEWPOINTS HAVE SHOWN A STEADY RISE IN THE COLORADO RIVER VALLEY AS WELL IN THIS TIME FRAME. THERE WAS AN AREA OF CLOUDS THAT POPPED UP LATE YESTERDAY EVENING IN LA PAZ AND SOUTHERN MOHAVE COUNTIES WHICH HAS MOVED NORTH OVERNIGHT AND EVEN TRIGGERED SOME RETURNS ON RADAR THIS MORNING. AS A RESULT, POPS WERE TWEAKED UP A BIT TO ACCOUNT FOR THE POTENTIAL OF A FEW SPRINKLES OR A VERY LIGHT SHOWER REACHING THE GROUND IN SOUTHERN MOHAVE AND SOUTHEAST SAN BERNARDINO COUNTIES. THE FLOW ALOFT REMAINS SOUTH TO SOUTHEAST INTO TONIGHT WHICH WILL CONTINUE TO TRANSPORT MOISTURE ON UP. PWATS WILL CONTINUE TO RISE THROUGH THE DAY AND BE OVER AN INCH ACROSS MOST OF THE SAN BERNARDINO COUNTY DESERTS, SOUTHERN CLARK AND CENTRAL AND SOUTHERN MOHAVE COUNTIES. WHILE WE WILL HAVE THE MOISTURE GOING FOR US TODAY AS WELL AS SUFFICIENT INSTABILITY AND CAPE VALUES (LI`S OF 0 TO -2 COMPUTED AT THE SURFACE AND CAPE VALUES OF 300-600 J/KG), THERE IS REALLY NO REAL MECHANISM OTHER THAN TERRAIN AND HEATING TO DRIVE STORMS. THE MID AND HIGHER LEVEL CLOUD COVER STREAMING NORTH THIS MORNING IS NOT TOO THICK AT THE PRESENT BUT COULD BE ENOUGH TO TRIM BACK ON ACTIVITY IN MOHAVE COUNTY OR DELAY THE START OF IT. NORTH OF THIS AREA, IT WILL BE TOO DRY AND TOO STABLE TODAY TO SEE MUCH ACTIVITY THOUGH WE MAY SEE SOME CUMULUS DEVELOP THIS AFTERNOON ESPECIALLY OVER THE SOUTHERN SIERRA. HIGH TEMPS WERE TWEAKED UP A FEW DEGREES BASED ON YESTERDAY`S HIGHS AS WELL AS A BLEND OF THE LATEST STATISTICAL GUIDANCE. ACTIVITY SHOULD DECREASE THIS EVENING WITH THE LOSS OF HEATING. THERE IS SOME POTENTIAL THURSDAY THAT SOME SORT OF MID-LEVEL WEAKNESS AND ASSOCIATED PV MAX HEADS NORTHWEST, HOWEVER, THIS MAY ALSO DEPEND ON WHAT GOES ON TO OUR SOUTHEAST THIS EVENING OVER THE CENTRAL AND SOUTHERN PARTS OF ARIZONA. OTHERWISE MOISTURE WILL LINGER AND SPREAD FURTHER NORTH ON THURSDAY AND BE SUFFICIENT FOR SHOWERS AND STORMS IN ANY PART OF THE AREA BY FRIDAY. AGAIN, HEATING AND TERRAIN WILL MAINLY DRIVE STORMS. TEMPS WILL REMAIN NEAR NORMAL FOR HIGHS. THE MAIN THREATS IN AND NEAR STORMS WILL BE GUSTY WINDS, HAIL, BLOWING DUST AND FLASH FLOODING IN ANY STRONGER OR SLOWER MOVING STORMS. THE FLASH FLOOD THREAT WILL INCREASE A BIT MORE THURSDAY INTO FRIDAY AS THE MOISTURE CONTENT OF THE AIR INCREASES. .LONG TERM...SATURDAY THROUGH TUESDAY. IT IS LOOKING LIKE A LOW GRADE MONSOON PATTERN FOR THIS PERIOD. HIGH PRESSURE CENTERED NEAR THE FOUR CORNERS REGION SATURDAY WILL KEEP A SOUTHERLY FLOW OVER THE AREA AND ENOUGH MOISTURE AND INSTABILITY FOR AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS AREA WIDE. THE MODELS DO NOT REALLY SHOW MUCH OF A SHIFT IN THE HIGH CENTER WITH TIME BUT THEY ARE HINTING AT THE FLOW MAYBE BECOMING MORE SOUTHWESTERLY WITH SOME DRYING ACROSS THE WESTERN PART OF THE FORECAST AREA WITH TIME. SINCE THE GFS AND ECMWF ARE BOTH SHOWING THIS TREND I WENT AHEAD AND LOWERED POPS A TOUCH IN THE WEST SUNDAY AND MONDAY AND LOWERED POPS A BIT MORE FOR TUESDAY. IF YOU BELIEVE THE MODELS THERE MAY NOT BE ANY THUNDERSTORMS IN THE CWA BY TUESDAY BUT AS WE HAVE MENTIONED BEFORE...THE MODELS FREQUENTLY GET TOO AGGRESSIVE FLUSHING MOISTURE OUT THIS TIME OF YEAR. SO I KEPT A SLIGHT CHANCE OF THUNDERSTORMS IN TUESDAY FOR MAINLY MOHAVE AND LINCOLN COUNTIES AND THE HIGHER TERRAIN OF CLARK COUNTY. I KEPT TEMPERATURES CLOSE TO OR JUST SLIGHTLY ABOVE NORMAL FOR THE LONG TERM WHICH IS CLOSE TO THE GFS MEX GUIDANCE. I AM NOT READY TO BUY THE SIGNIFICANT WARMING INDICATED BY THE ECE GUIDANCE WHICH HAS TEMPERATURES 5 PLUS DEGREES ABOVE NORMAL SUNDAY THROUGH TUESDAY. && .SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES WEDNESDAY THROUGH MONDAY. && $$ UPDATE...PIERCE SHORT TERM/AVIATION...STACHELSKI LONG TERM...HARRISON FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
126 PM EDT WED JUL 29 2015 .SYNOPSIS... HOT TEMPERATURES ARE EXPECTED ONCE AGAIN ACROSS THE NORTH COUNTRY WITH HIGHS IN THE UPPER 80S TO LOWER 90S. A FEW THUNDERSTORMS WILL BE POSSIBLE OVER THE HIGHER TERRAIN THIS AFTERNOON...BUT A MUCH BETTER CHANCE FOR THUNDERSTORMS WILL COME ON THURSDAY AS A COLD FRONT MOVES ACROSS THE REGION. NUMEROUS THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE NORTHERN ADIRONDACKS OF NEW YORK BY MIDDAY ON THURSDAY AND MOVE EAST THROUGH THE AFTERNOON. THESE THUNDERSTORMS WILL ALSO HAVE THE POTENTIAL TO BE STRONG OR SEVERE WITH STRONG AND GUSTY WINDS...HAIL...AND HEAVY DOWNPOURS. COOLER AND DRIER WEATHER RETURNS ON FRIDAY AS THE COLD FRONT EXITS THE AREA THURSDAY NIGHT. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 1155 AM EDT WEDNESDAY...GOING FORECAST IN GOOD SHAPE. TEMPERATURES ARE ALREADY IN THE MID 80S WITH SEVERAL MORE HOURS OF HEATING TO GO. LATEST RAP ANALYSIS ALSO SHOWING BETWEEN 500-1500 J/KG OF MLCAPE...BUT STILL CAPPED FOR THE TIME BEING. CU FIELD IS STARTING TO FORM OVER THE HIGHER ELEVATIONS. AN ISOLATED SHOWER/STORM REMAINS POSSIBLE THIS AFTERNOON. PREVIOUS DISCUSSION FROM 958 AM WEDNESDAY... RIDGING ALOFT AND AT THE SURFACE WILL PROVIDE FOR ANOTHER MOSTLY SUNNY AND HOT DAY. DO HAVE SOME THIN CIRRUS SPILLING OVER THE TOP OF THE RIDGE BUT NOT ENOUGH TO OBSCURE THE SUN. WILL ALSO HAVE A CU-FIELD DEVELOP THIS AFTERNOON...MAINLY OVER THE TERRAIN. LOW LEVEL THERMAL FIELDS ARE ABOUT 2C WARMER THAN YESTERDAY...WHICH SHOULD RESULT IN TEMPERATURES ABOUT 3 DEGREES WARMER THAN YESTERDAY. THIS WILL YIELD HIGHS IN THE UPPER 80S AND LOWER 90S AREA-WIDE. THE HEAT COMBINED WITH DEW POINTS IN THE MID/UPPER 60S WILL PRODUCE HEAT INDEX VALUES OF 91 TO 97 DEGREES. THE HEAT/HUMIDITY WILL ALSO LEAD TO THE DEVELOPMENT OF BETWEEN 500-1500 J/KG OF MLCAPE. MOST OF THE REGION SHOULD REMAIN CAPPED...BUT THE HIGHER TERRAIN MAY PRODUCE JUST ENOUGH LIFT TO TRIGGER AN ISOLATED SHOWER OR THUNDERSTORM OR TWO. WITH ONLY LIMITED WIND SHEAR (20-25 KNOTS 0-6KM)...A SEVERE THREAT IS NOT ANTICIPATED. && .SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/... AS OF 414 AM EDT WEDNESDAY...WE ARE STILL LOOKING AT THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS ON THURSDAY ACROSS MUCH OF THE AREA. A SHARP COLD FRONT WILL MOVE INTO THE SAINT LAWRENCE VALLEY BY MIDDAY. THE MOISTURE GRADIENT ASSOCIATED WITH THE FRONT IS RATHER SHARP...SO THIS BOUNDARY WILL BE A GOOD SOURCE OF LIFT AS IT MOVES EASTWARD THURSDAY AFTERNOON. THE ATMOSPHERE WILL DESTABILIZE IN ADVANCE OF THE FRONT WITH WITH HIGHS IN THE MID 80S TO LOWER 90S AND DEW POINTS WILL INTO THE 60S. STILL EXPECTING THIS TO RESULT IN CAPE VALUES IN THE 1000-1500 J/KG RANGE. WHAT CONTINUES TO STAND OUT IS THE INCREASING DEEP LAYER SHEAR OVER THE TOP OF THE COLD FRONT AND INSTABILITY AXIS TO SUPPORT THE DEVELOPMENT OF ORGANIZED STORMS WHICH BASED ON THE STRENGTH OF THE INSTABILITY AND SHEAR...SHOULD BECOME STRONG TO SEVERE. AT THIS TIME...THINKING STORMS FORM OVER THE NORTHERN ADIRONDACKS AND QUICKLY INTENSIFY WITH THE CHAMPLAIN VALLEY AND REMAINDER OF VERMONT HAVING THE BEST CHANCE TO EXPERIENCE THE STRONG TO SEVERE STORMS. WILL INCLUDE THE MENTION OF GUSTY WINDS...HAIL...AND HEAVY DOWNPOURS IN THE FORECAST. NARROW BAND OF STORMS EXITS THE AREA BY EARLY EVENING AND WITH COLD FRONT ALSO EXITING THE AREA...COOLER AND DRIER WEATHER SHOULD MOVE IN FOR THURSDAY NIGHT AND FRIDAY WITH HIGHS ON FRIDAY CLOSER TO SEASONAL NORMALS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 310 AM EDT WEDNESDAY...LITTLE OVERALL CHANGE FROM PREVIOUS FORECASTER THINKING IN REGARDS TO THE UPCOMING PATTERN FOR THE EXTENDED PERIOD WITH MEDIUM RANGE GLOBAL MODELS REMAINING IN GOOD AGREEMENT DEPICTING A LARGE-SCALE POLAR UPPER LOW TAKING RESIDENCE OVER HUDSONS BAY. THIS LEAVES THE NORTHEAST IN A PERSISTENT BROAD UPPER TROUGH WITH SEVERAL PIECES OF WEAK SHORTWAVE ENERGY MOVING THROUGH THE FLOW ALOFT. FIRST PIECE MOVES THROUGH ON SATURDAY AND THIS ENERGY COMBINED WITH DAYTIME HEATING MAY TRIGGER A FEW SHOWERS AND/OR THUNDERSTORMS, THOUGH WITH THE LACK OF ANY STRONG FORCING AND LIMITED DEEP LAYER MOISTURE RAINFALL SHOULD BE SHOWERY IN NATURE AND ON THE LIGHT SIDE. BEST CHANCES FOR SHOWERS/STORMS DURING THE PERIOD STILL LOOK TO BE MONDAY AND ESPECIALLY TUESDAY AS A COUPLE STRONGER SHORTWAVES SHIFT THROUGH THE REGION AS THE UPPER LOW DIGS SLIGHTLY SOUTHWARD FROM JAMES BAY INTO THE GREAT LAKES. THIS WILL ALLOW A WEAK COLD FRONT TO MOVE ACROSS THE AREA AS A BETTER FOCUS FOR PRECIPITATION. TEMPERATURES THROUGH THE PERIOD WILL BE NEAR NORMAL WITH HIGHS IN THE MID 70S TO LOWER 80S, AND LOWS IN THE MID 50S TO LOWER 60S. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... THROUGH 18Z THURSDAY...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH SCT-BKN MID/HIGH CLOUDS DRIFTING THROUGH THE REGION. SOUTHWEST (EXCEPT SOUTHEAST AT KPBG/KRUT) AT 5 TO 10 KNOTS THROUGH THE DAY, GOING CALM AGAIN AFTER 00Z. WINDS JUST OFF THE SURFACE PICK UP TONIGHT AHEAD OF AN APPROACHING COLD FRONT WHICH SHOULD INHIBIT ANY FOG AT KSLK BUT STILL POSSIBLE AT KMPV. SHOWERS/THUNDERSTORMS DEVELOPING ALG/AHD COLD FRONT IN NRN NY BETWEEN 14-17Z AND AFT 17Z IN VT. OUTLOOK 12Z THURSDAY THROUGH SUNDAY... 18Z THU - 00Z FRI: VFR WITH BRIEF MVFR/IFR IN SHOWERS/STORMS. ISOLATED SEVERE TURBULENCE/WINDS/HAIL POSSIBLE. 00Z FRI - 12Z SAT: MAINLY VFR. CHANCE MVFR/IFR FOG. 12Z SAT - 00Z MON: MAINLY VFR. CHANCE SHRA/TSRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...EVENSON NEAR TERM...EVENSON/MUCCILLI SHORT TERM...EVENSON LONG TERM...LAHIFF AVIATION...SLW
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
329 PM CDT WED JUL 29 2015 .DISCUSSION... HOT AND HUMID CONDITIONS CONTINUE ACROSS MIDDLE TENNESSEE THIS AFTERNOON AS THE SHOWERS AND THUNDERSTORMS THAT MOVED THROUGH THE AREA EARLIER THIS MORNING LEFT QUITE THE SOUPY AIRMASS IN PLACE. FOR THIS EVENING AND TONIGHT...STILL THINK A FEW ISOLATED SHOWERS AND THUNDERSTORMS MAY DEVELOP...BUT WILL SIDE WITH THE HRRR AS MUCH OF THE AREA WILL REMAIN DRY. A COLD FRONT WILL PUSH ACROSS MIDDLE TENNESSEE OVERNIGHT BRINGING MUCH DRIER AIR...A VERY NICE CHANGE IN TIME FOR THE WEEKEND. THURSDAY THROUGH TUESDAY...A QUIET WEATHER PATTERN CAN BE EXPECTED...ESPECIALLY FOR THE BEGINNING OF AUGUST...AS HIGH PRESSURE BUILDS OVER THE REGION. CONDITIONS WILL NOT BE QUITE AS HUMID ALTHOUGH HIGHS WILL STILL REACH THE LOWER 90S IN MOST LOCATIONS. BIGGEST DIFFERENCE WILL BE FELT WITH LOW TEMPERATURES WITH MID TO UPPER 60S EXPECTED INSTEAD OF THE LOWER TO MID 70S. TEMPERATURES WILL SLOWLY BEGIN TO INCREASE AFTER THE WEEKEND...ALONG WITH HUMIDITY VALUES TOO. BY THE MIDDLE OF NEXT WEEK...UPPER LEVEL PATTERN WILL AGAIN SHIFT TO NORTHWEST FLOW AS THE SURFACE HIGH LOSES ITS STRONGHOLD. AS A RESULT...THUNDERSTORM CHANCES WILL INCREASE TUESDAY NIGHT AND LIKELY REMAIN IN THE FORECAST THEREAFTER. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 75 90 66 90 / 20 10 0 0 CLARKSVILLE 71 88 65 89 / 20 0 0 0 CROSSVILLE 72 85 64 84 / 30 20 0 0 COLUMBIA 75 90 66 90 / 20 20 0 0 LAWRENCEBURG 74 90 66 89 / 20 20 0 0 WAVERLY 73 89 67 89 / 20 0 0 0 && .OHX WATCHES/WARNINGS/ADVISORIES... HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR TNZ005>007-023>027- 056>061-093>095. && $$ HURLEY
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1232 PM CDT WED JUL 29 2015 .DISCUSSION... UPDATED FOR AVIATION DISCUSSION FOR 18Z TAFS && .PREV DISCUSSION... /ISSUED 1026 AM CDT WED JUL 29 2015/ UPDATE... BROKEN/OVERCAST MIDLEVEL ALTOCUMULUS DECK WAS SLOWLY DRIFTING SOUTH THROUGH SOUTHWEST TN AND PORTIONS OF NORTH MS. EVEN WHERE SKIES WERE CLOUDY...HEAT INDICES WERE NEAR 100 AT 10 AM CDT. FOR THE MORNING UPDATE...HAVE TRIMMED RAIN CHANCES BACK TO BELOW MENTIONABLE LEVELS UNDER THE UPPER RIDGE/WEST OF THE TN RIVER VALLEY. HRRR WAS OVERDONE WITH RESPECT TO MORNING STORMS OVER NORTHEAST MS... BUT EVEN IT WAS PREDOMINATELY DRY WEST OF THE MS RIVER THIS AFTERNOON. THE 12Z NAM AND 06Z SHOWED NO QPF OVER ANY OF THE MIDSOUTH TODAY. GIVEN 700MB TEMPS OF 12C TO 13C...THIS SCENARIO ISN/T OUT OF THE QUESTION. TEMPERATURE AND HEAT INDEX FORECAST APPEAR ON TRACK...WITH NO ADJUSTMENTS NEEDED AT MIDMORNING. PWB PREV DISCUSSION... /ISSUED 341 AM CDT WED JUL 29 2015/ DISCUSSION... ONE MORE DAY OF DANGEROUS HEAT AND HUMIDITY IS EXPECTED ON WEDNESDAY WITH RELIEF COMING IN THE FORM OF A COLD FRONT MOVING THROUGH THE MID-SOUTH LATE WEDNESDAY NIGHT/THURSDAY MORNING... CURRENTLY...A VERY WARM NIGHT WAS ONGOING ACROSS THE MID-SOUTH WITH TEMPERATURES NEAR 80 DEGREES AND DEWPOINTS IN THE MID TO UPPER 70S. ALOFT...AN UPPER LEVEL RIDGE WAS ANCHORED ACROSS MUCH OF THE SOUTHERN US. AT THE SURFACE...HIGH PRESSURE WAS IN PLACE ACROSS MUCH OF THE SOUTHEASTERN US WITH A COLD FRONT ORIENTED SW TO NE FROM THE TX PANHANDLE THROUGH NORTHERN MO/SRN WI. EARLIER IN THE EVENING...A SUBSTANTIAL COMPLEX OF THUNDERSTORMS DEVELOPED ACROSS PORTIONS OF MIDDLE TENNESSEE WHICH EXPELLED AN OUTFLOW BOUNDARY SOUTHWEST INTO PORTIONS OF THE TENNESSEE RIVER VALLEY. WHILE SURFACE WINDS ARE VARIABLE...THAT BOUNDARY IS LIKELY STILL PRESENT THROUGH THE REGION BUT BECOMING MORE DIFFUSE WITH TIME. FOR WEDNESDAY...EXCESSIVE HEAT IS STILL FORECAST...HOWEVER THERE ARE A FEW COMPLICATING FACTORS. HI-RES MEMBERS INCLUDING THE NSSL WRF AND THE HRRR DEVELOP THUNDERSTORMS EARLY IN THE DAY AS A WEAK DISTURBANCE DIVES SOUTHEAST AROUND THE PERIPHERY OF THE SURFACE RIDGE. THE AFOREMENTIONED OUTFLOW BOUNDARY MAY SERVE AS A FOCUS FOR THIS DEVELOPMENT BUT THIS SOLUTION IS EXTREMELY UNCERTAIN AT THIS POINT. IF IT WERE TO UNFOLD AS SUCH...PORTIONS OF WEST TENNESSEE ALONG THE TN RIVER MAY NOT REACH HEAT ADVISORY CRITERIA OWING TO CLOUD COVER/PRECIP. AT THIS POINT...DID NOT ADJUST THE ADVISORY GIVEN THE AFOREMENTIONED UNCERTAINTY. BELIEVE THE HI-RES SOLUTIONS TO BE MUCH TOO AGGRESSIVE WITH PRECIP DEVELOPMENT...BUT IT IS WORTH MENTIONING. FURTHER WEST TOWARD THE MS RIVER...EXCESSIVE HEAT WARNINGS REMAIN IN EFFECT ACROSS E AND NE AR/NW MS/W TN WITH HIGH CONFIDENCE IN DANGEROUS HEAT INDICES DEVELOPING FROM MIDDAY THROUGH EARLY EVENING. MANY LOCATIONS WILL EXPERIENCE SEVERAL HOURS OF HEAT INDICES BETWEEN 111 AND 114 DEGREES GIVEN THE EXTREMELY MOIST BOUNDARY LAYER IN PLACE WITH DEWPOINTS IN THE MID AND UPPER 70S AND TEMPERATURES IN THE UPPER 90S. PRECIPITATION IS NOT EXPECTED TO HINDER SOLAR HEATING AND SHOULD HOLD OFF UNTIL THE EVENING HOURS. WEDNESDAY NIGHT...THE FRONTAL BOUNDARY APPROACHES FROM THE NORTH BUT CONSIDERABLE UNCERTAINTY EXISTS WITH RESPECT TO COVERAGE OF SHOWERS AND THUNDERSTORMS. THERE WILL LIKELY BE ISOLATED DEVELOPMENT AFTER 00Z THURSDAY ALONG THE FRONT BUT PLACING THIS DEVELOPMENT IS DIFFICULT AT THIS TIME. FOR NOW...SLIGHT CHANCE TO CHANCE POPS WERE MAINTAINED TO ACCOUNT FOR THIS. BY THURSDAY...THE FRONTAL BOUNDARY WILL CONTINUE TO PUSH SOUTH WITH DRIER AIR ADVECTING INTO THE REGION. NORTHERN MISSISSIPPI MAY STILL NEAR HEAT ADVISORY CRITERIA EARLIER IN THE DAY BUT EVEN THIS SHOULD BE SHORT-LIVED AS CLOUD COVER AND SHOWERS/TSTORMS SHOULD PROVIDE RELIEF DURING THE MID TO LATE AFTERNOON HOURS. BY THURSDAY NIGHT...THE FRONT WILL HAVE CLEARED THE REGION LEAVING A MUCH MORE PLEASANT AIRMASS IN PLACE WITH DEWPOINTS IN THE LOW TO MID 60S AND TEMPERATURES IN THE UPPER 60S TO NEAR 70 THURSDAY NIGHT. THROUGH THE WEEKEND...A SLOW WARMUP IS EXPECTED BUT SEVERAL DAYS OF BEARABLE TEMPERATURES ARE FORECAST WITH LOWER HUMIDITY. THIS PERIOD SHOULD ALSO BE DRY FOR THE ENTIRE REGION. IN THE LONG-TERM...UPPER LEVEL RIDGING STRENGTHENS ACROSS THE DESERT SOUTHWEST WITH A PERSISTENT AREA OF UPPER LEVEL LOW PRESSURE ACROSS THE EAST-CENTRAL CANADIAN PROVINCES. THE MID-SOUTH WILL FALL SOMEWHERE BETWEEN THESE TWO FEATURES WITH WARMING TEMPERATURES ONCE AGAIN. A SLOW INCREASE IN HEIGHTS SUGGESTS THAT ANOTHER WARM TO HOT PERIOD MAY DEVELOP BUT IT IS TOO SOON TO TELL HOW HOT...BUT IT IS WORTH WATCHING. TVT && .AVIATION... 18Z TAF CYCLE VFR CONDITIONS SHOULD PREVAIL THROUGH THE PERIOD. THERE CLOUD BE A FEW THUNDERSTORMS ACROSS WEST TENNESSEE AND NORTHEAST MISSISSIPPI THIS AFTERNOON. INCLUDED VCTS AT BOTH KMKL AND KTUP TO ACCOUNT FOR THIS. WINDS SHOULD BE LIGHT THROUGHOUT THE PERIOD. TLSJR && .MEG WATCHES/WARNINGS/ADVISORIES... AR...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR CLAY- CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR- MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS. MO...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR DUNKLIN- PEMISCOT. MS...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR COAHOMA- DESOTO-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-TUNICA. HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ALCORN-BENTON MS- CALHOUN-CHICKASAW-ITAWAMBA-LAFAYETTE-LEE MS-MONROE-PONTOTOC- PRENTISS-TIPPAH-TISHOMINGO-UNION-YALOBUSHA. TN...EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR DYER- FAYETTE-LAKE-LAUDERDALE-OBION-SHELBY-TIPTON. HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BENTON TN-CARROLL- CHESTER-CROCKETT-DECATUR-GIBSON-HARDEMAN-HARDIN-HAYWOOD- HENDERSON-HENRY-MADISON-MCNAIRY-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
542 PM CDT WED JUL 29 2015 .DISCUSSION... See 00Z Aviation Discussion below. && .AVIATION... Area radars and short-term models show another night of convection on tap, mainly SE NM, although many boundaries abound elsewhere. Regardless, VFR conditions will prevail next 24 hours in return flow under persistent ridging aloft. Forecast soundings develop a widespread cu field by late Thursday morning, w/initial bases 4.5-6 kft agl. && .PREV DISCUSSION... /ISSUED 332 PM CDT WED JUL 29 2015/ UPDATE... Updated forecast for increased chance of thunderstorms over the northern Permian Basin, southeast New Mexico and mountain areas. DISCUSSION... By mid-afternoon, showers and thunderstorms were developing along a surface boundary entering the northern Permian Basin in an area characterized by CAPE values ranging from 500 to 1000. Continued development along this boundary as well as any additional outflow boundaries that might develop is possible through early evening as the atmosphere across the region is uncapped. Though instability is less over the Permian Basin, will need to watch boundaries for possible foci of development. Thunderstorms will begin to decrease this evening with a loss of heating. Though shear is insufficient for organized thunderstorm activity, DCAPE values are significant, in excess of 1000. Sub-cloud evaporation will be capable of producing strong and possibly damaging downbursts. PREV DISCUSSION... /ISSUED 224 PM CDT WED JUL 29 2015/ DISCUSSION...As of 2:15 PM CDT Wednesday...Hot and muggy weather continues with convection starting in the usual places...the Davis/Guadalupe Mtns and the adjacent Plains. Convection is also forming a little further east in Western Lea and Eddy Counties along the thetae ridge per the HRRR and RAP13 high res models. The persistent subtropical ridge centered over the Arklatex area will shift west over the Central Plains as a trough deepens in the eastern US. This might actually result in no convection in the CWA Thursday thru Friday due to increased subsidence from the ridge center moving overhead. Temps might not be as hot as the previous week...but will remain above normal. Medium range models are hinting at the possibility of convection in the CWA over the weekend as the ridge continues to shift west to over the four corners area. This will bring a NW flow aloft possibly bringing convection into the area out of Northern New Mexico. As a trough in the EastPac moves into the Pacific NW early next week the ridge will flatten and elongate bringing a return to drier weather...with triple digits possible once again in the Plains by mid week. Strobin && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 44
AREA FORECAST DISCUSSION
NWS MIDLAND/ODESSA TX
224 PM CDT WED JUL 29 2015 .DISCUSSION...As of 2:15 PM CDT Wednesday...Hot and muggy weather continues with convection starting in the usual places...the Davis/Guadalupe Mtns and the adjacent Plains. Convection is also forming a little further east in Western Lea and Eddy Counties along the thetae ridge per the HRRR and RAP13 high res models. The persistent subtropical ridge centered over the Arklatex area will shift west over the Central Plains as a trough deepens in the eastern US. This might actually result in no convection in the CWA Thursday thru Friday due to increased subsidence from the ridge center moving overhead. Temps might not be as hot as the previous week...but will remain above normal. Medium range models are hinting at the possibility of convection in the CWA over the weekend as the ridge continues to shift west to over the four corners area. This will bring a NW flow aloft possibly bringing convection into the area out of Northern New Mexico. As a trough in the EastPac moves into the Pacific NW early next week the ridge will flatten and elongate bringing a return to drier weather...with triple digits possible once again in the Plains by mid week. Strobin && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 74 97 73 96 / 0 10 0 10 CARLSBAD NM 70 97 69 96 / 10 10 0 0 DRYDEN TX 75 100 74 99 / 0 0 0 0 FORT STOCKTON TX 72 98 73 97 / 0 0 0 0 GUADALUPE PASS TX 68 89 68 88 / 20 10 10 10 HOBBS NM 70 95 70 93 / 0 10 10 10 MARFA TX 59 90 57 88 / 20 10 0 10 MIDLAND INTL AIRPORT TX 73 98 72 97 / 0 0 0 10 ODESSA TX 73 98 74 97 / 0 0 0 0 WINK TX 75 103 73 101 / 0 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 80/33