Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/11/15


AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
154 PM PDT WED SEP 9 2015 .SYNOPSIS... UPPER-LEVEL HIGH PRESSURE WILL CONTINUE HOT WEATHER THROUGH THURSDAY...WITH SLOW COOLING FRIDAY INTO EARLY NEXT WEEK. AFTERNOON AND EARLY EVENING HEAVY THUNDERSTORMS WILL CONTINUE OVER THE INLAND AREAS THROUGH THURSDAY...LEADING TO AN ENHANCED FLASH FLOOD THREAT...AS MOISTURE FROM HURRICANE LINDA MOVES OVER THE REGION. THE AFTERNOON AND EARLY EVENING THUNDERSTORM THREAT CONTINUES FOR THE MOUNTAINS AND DESERTS THROUGH THE WEEKEND. EVEN COASTAL AREAS MAY SEE A THUNDERSTORM OR TWO THIS AFTERNOON AND THURSDAY. COOLER AND DRIER NEXT WEEK AS A TROUGH OF LOW PRESSURE MOVES IN ALONG THE WEST COAST. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... MORNING SOUNDING CONTINUES TO SHOW A MOIST AND UNSTABLE ATMOSPHERE...WITH 1.65 INCHES OF PRECIPITABLE WATER AND 780 J/KG OF MOST UNSTABLE CAPE. CURRENT SPC MESOANALYSIS SHOWS 1000-1500 J/KG OF SURFACE BASED CAPE. THUS...RADAR SHOWS THAT THUNDERSTORMS ARE ERUPTING OVER THE MOUNTAINS...HIGH DESERTS AND VALLEYS THIS AFTERNOON. THE SOUNDING ALSO SHOWS MORE OF AN EASTERLY COMPONENT TO THE WINDS IN THE LOW LEVELS. WITH THE WRF SHOWING 700-500 MB WINDS OUT OF THE EAST OF AROUND 10-15 KT AND THE SURFACE CONVERGENCE BOUNDARY SETTING UP IN THE VALLEYS...THIS IS RESULTING IN THUNDERSTORMS DRIFTING IN THE VALLEY AREAS TODAY. IN FACT...THE LATEST HRRR SHOWS THAT THE SOME SHOWERS OR THUNDERSTORMS COULD DRIFT INTO THE COASTAL AREAS THIS AFTERNOON...SO HAVE ADDED A SLIGHT CHANCE OF THUNDERSTORMS/SHOWERS FOR THOSE AREAS WITH THE AFTERNOON FORECAST. ON THURSDAY...PRECIPITABLE WATER INCREASES TO 2 INCHES ACCORDING TO THE GFS AND NAM...AS THE CIRCULATION OF LINDA MOVES NORTHWEST TO A POSITION FAR WEST OF NORTHERN BAJA...RESULTING IN CONTINUED EAST TO SOUTHEAST FLOW BRINGING THE MOISTURE INTO THE AREA. WRF SHOWS THE EAST WINDS IN THE 700-500 MB LAYER INCREASING TO 20 KT...WHICH MEANS THAT STORMS SHOULD BE MOVING QUICKER AND THAT THEY MAY BE ABLE TO DRIFT INTO COASTAL AREAS AS WELL. ONE POSSIBLE LIMITING FACTOR ON THURSDAY IS IF THERE IS TOO MUCH CLOUD COVER...WHICH COULD DECREASE THE AMOUNT OF INSTABILITY. THERE IS STILL A FAIR AMOUNT OF MOISTURE IN THE REGION ON FRIDAY...WITH PRECIPITABLE WATER ONLY DECREASING TO 1.7-1.8 INCHES UNDER SOUTHEAST FLOW ALOFT...SO THUNDERSTORMS ARE LIKELY TO DEVELOP AGAIN FRIDAY AFTERNOON AND EARLY EVENING IN THE MOUNTAINS AND VALLEYS. THE AFTERNOON AND EARLY EVENING THUNDERSTORM THREAT CONTINUES FOR THE MOUNTAINS AND DESERTS SATURDAY WITH MOISTURE DIMINISHING A LITTLE...AND THEN THE GFS SHOWS MOISTURE DECREASING FURTHER ON SUNDAY. FOR DETAILS ON THE FLASH FLOOD THREAT...PLEASE SEE THE HYDROLOGY SECTION BELOW. THE HEAT AND MUGGY CONDITIONS IS THE OTHER STORY...AS OVERNIGHT LOWS WERE ONLY IN THE LOW TO MID 70S. THE LOW OF 77 DEGREES AT LINDBERGH FIELD WAS ONE DEGREE BELOW THE ALL-TIME HIGHEST MINIMUM TEMPERATURE. CURRENTLY...THE TEMPERATURES ARE SEVERAL DEGREES ARE HIGHER THAN AT THIS TIME YESTERDAY. SOME EASTERLY DOWNSLOPE FLOW ASSOCIATED WITH THE CIRCULATION OF LINDA COULD BRING CONTINUED HOT CONDITIONS TO THE SAN DIEGO COUNTY COAST AND VALLEYS THURSDAY AS WELL...ALTHOUGH IT DOES NOT LOOK QUITE AS HOT AS THE MODELS WERE SHOWING YESTERDAY. A SLOW COOLING TREND LOOKS TO START FRIDAY INTO SATURDAY...WITH MORE SIGNIFICANT COOLING SUNDAY INTO EARLY NEXT WEEK AS THE RIDGE WEAKENS AND WE GET A TROUGH ALONG THE WEST COAST. NIGHT AND MORNING MARINE LAYER CLOUDS COULD RETURN BY SATURDAY NIGHT. && .AVIATION... 092000Z...GENERALLY...NO VIS RESTRICTIONS INTO THURSDAY WITH OCCASIONAL CLOUDS ABOVE 10000 FEET MSL. BETWEEN 09/20-10/02Z THIS AFTERNOON...THUNDERSTORMS ARE POSSIBLE IN THE MOUNTAINS...DESERTS AND VALLEYS WITH BASES 8000 FEET MSL AND TOPS TO 45000 FEET. EXPECT STRONG UPDRAFTS AND DOWNDRAFTS...MAINLY SMALL HAIL...AND SURFACE GUSTS OVER 35 KT NEAR ANY STORM. IN STORMS LOCAL VIS REDUCED TO 2SM IN HEAVY RAIN AND/OR BLOWING DUST IN DESERTS. CONFIDENCE IN THE FORECAST OF A VERY LOW RISK OF LOW CLOUDS FOR KSAN TONIGHT IS HIGH...WITH EVEN LESS RISK OF LOW CLOUDS AT KONT OVERNIGHT TONIGHT. && .MARINE... 1255 PM...THERE IS A SLIGHT CHANCE OF A THUNDERSTORM THURSDAY AFTERNOON AND EVENING NEAR THE COAST. OTHERWISE...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SUNDAY. && .BEACHES... 1255 PM...A NEW SOUTH SOUTHEAST SWELL FROM HURRICANE LINDA WILL ARRIVE THIS AFTERNOON INTO FRIDAY MORNING. THIS SWELL WILL PRODUCE 4- 6 FOOT SURF AT ORANGE COUNTY BEACHES INTO FRIDAY...WITH A FEW HIGHER SETS. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AT THE BEACHES THURSDAY AFTERNOON AND EVENING. THERE IS A BEACH HAZARDS STATEMENT IN EFFECT FOR ELEVATED SURF AND STRONG RIP CURRENTS THROUGH FRIDAY MORNING. && .HYDROLOGY... MODERATE TO HIGH FLASH FLOOD THREAT CONTINUES TODAY FOR THE MOUNTAINS...DESERTS AND THE VALLEYS...DUE TO THE MOIST AND UNSTABLE ATMOSPHERE. THUS...THUNDERSTORMS ARE ERUPTING OVER THE INLAND EMPIRE...HIGH DESERTS AND SAN BERNARDINO COUNT MOUNTAINS. THE WINDS ALOFT ARE SOMEWHAT WEAK AS WELL...RESULTING IN SOME SLOW MOVING STORMS WHICH ARE INCREASING THE THREAT OF FLASH FLOODING FURTHER. RAIN RATES OF 1 TO 2 INCHES PER HOUR WILL BE POSSIBLE UNDERNEATH THE HEAVIER STORMS. FLASH FLOODING HAS ALREADY OCCURRED IN FOREST FALLS THIS AFTERNOON. THE FLASH FLOOD WATCH CONTINUES THROUGH THURSDAY FOR THE MOUNTAINS...DESERTS AND VALLEYS...ALTHOUGH STORMS MAY BE MOVING QUICKER ON THURSDAY WHICH COULD DIMINISH THE FLASH FLOOD THREAT A BIT. HOWEVER...TRAINING STORMS COULD BE A CONCERN. THE THREAT LOWERS FURTHER FRIDAY INTO THE WEEKEND AS MOISTURE SLOWLY DECREASES. && .SKYWARN... SKYWARN ACTIVATION IS REQUESTED THROUGH EARLY EVENING FOR SAN DIEGO COUNTY...RIVERSIDE COUNTY...AND SAN BERNARDINO COUNTY. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR APPLE AND LUCERNE VALLEYS-COACHELLA VALLEY-RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY DESERTS- SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY VALLEYS-SAN GORGONIO PASS NEAR BANNING. HEAT ADVISORY UNTIL 6 PM PDT THURSDAY FOR ORANGE COUNTY INLAND AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY COASTAL AREAS-SAN DIEGO COUNTY VALLEYS-SANTA ANA MOUNTAINS AND FOOTHILLS. BEACH HAZARDS STATEMENT THROUGH FRIDAY MORNING FOR ORANGE COUNTY COASTAL AREAS. PZ...NONE. && $$ PUBLIC/HYDROLOGY...HARRISON AVIATION/MARINE/BEACHES...SMALL
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
958 AM PDT WED SEP 9 2015 .SYNOPSIS... UPPER-LEVEL HIGH PRESSURE WILL CONTINUE HOT WEATHER THROUGH THURSDAY...WITH SLOW COOLING FRIDAY INTO EARLY NEXT WEEK. AFTERNOON AND EARLY EVENING HEAVY THUNDERSTORMS WILL CONTINUE OVER THE INLAND AREAS THROUGH THURSDAY...LEADING TO AN ENHANCED FLASH FLOOD THREAT...AS MOISTURE FROM HURRICANE LINDA MOVES OVER THE REGION. THE AFTERNOON AND EARLY EVENING THUNDERSTORM THREAT CONTINUES FOR THE MOUNTAINS AND DESERTS THROUGH THE WEEKEND. EVEN COASTAL AREAS MAY SEE A THUNDERSTORM OR TWO THURSDAY. COOLER AND DRIER NEXT WEEK AS A TROUGH OF LOW PRESSURE MOVES IN ALONG THE WEST COAST. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... MORNING SOUNDING CONTINUES TO SHOW A MOIST AND UNSTABLE ATMOSPHERE...WITH 1.65 INCHES OF PRECIPITABLE WATER AND 780 J/KG OF MOST UNSTABLE CAPE. THE SOUNDING ALSO SHOWS MORE OF AN EASTERLY COMPONENT TO THE WINDS IN THE LOW LEVELS. VISIBLE SATELLITE SHOWS CIRRUS BLOW-OVER FROM LINDA MOVING IN FROM THE SOUTH...OBSCURING PARTS OF SAN DIEGO COUNTY AND THE COACHELLA VALLEY. ALTHOUGH THESE CLOUDS COULD HELP REDUCE TEMPERATURES A TINY BIT FOR THOSE AREAS...THERE IS STILL EXPECTED TO BE ENOUGH SUNSHINE TO CREATE ENOUGH INSTABILITY FOR THUNDERSTORMS TO ERUPT AGAIN THIS AFTERNOON AND EARLY EVENING. THE WRF SHOWS THE SURFACE CONVERGENCE BOUNDARY SETTING UP FARTHER WEST TODAY...OVER THE COASTAL FOOTHILLS...SO THAT COULD BE WHERE THUNDERSTORMS INITIATE. THE HRRR AND OTHER HI-RES MODELS FOCUS MUCH OF THE THUNDERSTORM ACTIVITY FOR THE RIVERSIDE AND SAN BERNARDINO COUNTY AREAS...INCLUDING THE MOUNTAINS...THE INLAND EMPIRE AND THE HIGH DESERTS...SO POPS HAVE BEEN ADJUSTED UPWARDS IN THOSE LOCATIONS. WITH THE WRF SHOWING 700-500 MB WINDS OUT OF THE EAST OF AROUND 10-15 KT...THIS SHOULD ALSO HELP WITH THUNDERSTORMS DRIFTING IN THE VALLEY AREAS TODAY. ON THURSDAY...PRECIPITABLE WATER INCREASES TO 2 INCHES ACCORDING TO THE GFS AND NAM...AS THE CIRCULATION OF LINDA MOVES NORTHWEST TO A POSITION FAR WEST OF NORTHERN BAJA...RESULTING IN CONTINUED EAST TO SOUTHEAST FLOW BRINGING THE MOISTURE INTO THE AREA. WRF SHOWS THE EAST WINDS IN THE 700-500 MB LAYER INCREASING TO 20 KT...WHICH MEANS THAT STORMS SHOULD BE MOVING QUICKER AND THAT THEY MAY BE ABLE TO DRIFT INTO COASTAL AREAS AS WELL. ONE POSSIBLE LIMITING FACTOR ON THURSDAY IS IF THERE IS TOO MUCH CLOUD COVER...WHICH COULD DECREASE THE AMOUNT OF INSTABILITY. THERE IS STILL A FAIR AMOUNT OF MOISTURE IN THE REGION ON FRIDAY...WITH PRECIPITABLE WATER ONLY DECREASING TO 1.7-1.8 INCHES UNDER SOUTHEAST FLOW ALOFT...SO THUNDERSTORMS ARE LIKELY TO DEVELOP AGAIN FRIDAY AFTERNOON AND EARLY EVENING IN THE MOUNTAINS AND VALLEYS. THE AFTERNOON AND EARLY EVENING THUNDERSTORM THREAT CONTINUES FOR THE MOUNTAINS AND DESERTS SATURDAY WITH MOISTURE DIMINISHING A LITTLE...AND THEN THE GFS SHOWS MOISTURE DECREASING FURTHER ON SUNDAY. FOR DETAILS ON THE FLASH FLOOD THREAT...PLEASE SEE THE HYDROLOGY SECTION BELOW. THE HEAT AND MUGGY CONDITIONS IS THE OTHER STORY...AS OVERNIGHT LOWS WERE ONLY IN THE LOW TO MID 70S. THE LOW OF 77 DEGREES AT LINDBERGH FIELD WAS ONE DEGREE BELOW THE ALL-TIME HIGHEST MINIMUM TEMPERATURE. WITH THE RIDGE ALOFT CONTINUING TO BUILD OVER THE REGION...TODAY WILL LIKELY BE THE HOTTEST DAY FOR MOST AREAS...WITH DAY-TIME HIGHS REACHING 10 TO 15 DEGREES ABOVE NORMAL...ALTHOUGH THE DESERTS WILL PROBABLY BE A LITTLE COOLER DUE TO INCREASED MOISTURE AND LOWERING 850 MB TEMPERATURES. SOME EASTERLY DOWNSLOPE FLOW ASSOCIATED WITH THE CIRCULATION OF LINDA COULD BRING CONTINUED HOT CONDITIONS TO THE SAN DIEGO COUNTY COAST AND VALLEYS THURSDAY AS WELL. A SLOW COOLING TREND LOOKS TO START FRIDAY INTO SATURDAY...WITH MORE SIGNIFICANT COOLING SUNDAY INTO EARLY NEXT WEEK AS THE RIDGE WEAKENS AND WE GET A TROUGH ALONG THE WEST COAST. NIGHT AND MORNING MARINE LAYER CLOUDS COULD RETURN BY SATURDAY NIGHT. && .AVIATION... 091600Z...GENERALLY...NO VIS RESTRICTIONS TODAY AND TONIGHT WITH OCCASIONAL CLOUDS ABOVE 10000 FEET MSL. BETWEEN 19-01Z TODAY...THUNDERSTORMS ARE POSSIBLE IN THE MOUNTAINS...DESERTS AND VALLEYS WITH BASES 8000 FEET MSL AND TOPS TO 45000 FEET. EXPECT STRONG UPDRAFTS AND DOWNDRAFTS...SMALL HAIL...AND SURFACE GUSTS OVER 35 KT NEAR ANY STORM. IN STORMS LOCAL VIS REDUCED TO 2SM IN HEAVY RAIN AND/OR BLOWING DUST IN DESERTS. CONFIDENCE IN THE FORECAST OF A VERY LOW RISK OF LOW CLOUDS FOR KSAN TONIGHT IS HIGH...WITH EVEN LESS RISK OF LOW CLOUDS AT KONT OVERNIGHT TONIGHT. && .MARINE... 800 AM...THERE IS A SLIGHT CHANCE OF A THUNDERSTORM THURSDAY AFTERNOON AND EVENING NEAR THE COAST. OTHERWISE...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SUNDAY. && .BEACHES... 800 AM...A NEW SOUTH SOUTHEAST SWELL FROM HURRICANE LINDA WILL ARRIVE THURSDAY. THIS SWELL WILL PRODUCE 5-7 FOOT SURF AT ORANGE COUNTY BEACHES THURSDAY INTO FRIDAY WITH A FEW HIGHER SETS. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS AT THE BEACHES THURSDAY AFTERNOON AND EVENING. && .HYDROLOGY... WITH THUNDERSTORMS EXPECTED TO DEVELOP IN THE INLAND VALLEYS OF SAN DIEGO COUNTY TODAY...THIS AREA HAS BEEN ADDED TO THE FLASH FLOOD WATCH. MODERATE TO HIGH FLASH FLOOD THREAT CONTINUES TODAY FOR THE MOUNTAINS...DESERTS AND THE VALLEYS...AS THE ATMOSPHERE WILL REMAIN MOIST AND UNSTABLE THROUGH THAT TIME. THIS WILL CREATE THE CHANCES FOR THUNDERSTORMS PRODUCING HEAVY RAIN. THE WINDS ALOFT WILL BE SOMEWHAT WEAK AS WELL...RESULTING IN SOME SLOW MOVING STORMS WHICH WILL INCREASE THE THREAT OF FLASH FLOODING FURTHER. RAIN RATES OF 1 TO 2 INCHES PER HOUR WILL BE POSSIBLE UNDERNEATH THE HEAVIER STORMS. THE FLASH FLOOD WATCH CONTINUES THROUGH THURSDAY FOR THESE AREAS...ALTHOUGH STORMS MAY BE MOVING QUICKER ON THURSDAY WHICH COULD DIMINISH THE FLASH FLOOD THREAT A BIT. THE THREAT LOWERS FURTHER FRIDAY INTO THE WEEKEND AS MOISTURE SLOWLY DECREASES. && .SKYWARN... SKYWARN ACTIVATION IS REQUESTED FOR NOON TODAY THROUGH EARLY EVENING FOR SAN BERNARDINO...RIVERSIDE AND SAN DIEGO COUNTIES. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR APPLE AND LUCERNE VALLEYS-COACHELLA VALLEY-RIVERSIDE COUNTY MOUNTAINS-SAN BERNARDINO COUNTY MOUNTAINS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY DESERTS- SAN DIEGO COUNTY MOUNTAINS-SAN DIEGO COUNTY VALLEYS-SAN GORGONIO PASS NEAR BANNING. HEAT ADVISORY UNTIL 6 PM PDT THURSDAY FOR ORANGE COUNTY INLAND AREAS-SAN BERNARDINO AND RIVERSIDE COUNTY VALLEYS-THE INLAND EMPIRE-SAN DIEGO COUNTY COASTAL AREAS-SAN DIEGO COUNTY VALLEYS-SANTA ANA MOUNTAINS AND FOOTHILLS. PZ...NONE. && $$ PUBLIC/HYDROLOGY...HARRISON AVIATION/MARINE/BEACHES...SMALL
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
215 PM MDT WED SEP 9 2015 .SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT) ISSUED AT 215 PM MDT WED SEP 9 2015 DRY WEST NORTHWEST FLOW PREVAILS AND KEEPS MOISTURE SOUTH OF OUR SOUTHERN BORDER. THERE IS REMOTE CHANCE THAT A BRIEF SHOWER/STORM FORMS OVER THE ERN SAN JUAN MOUNTAINS. WATER VAPOR SHOWS PRONOUNCED DRY LAYER ACROSS THE SOUTH...AND COULD BE ONE REASON WHY THE HRRR MODEL SHOWS NO SHOWERS/STORMS ACROSS THE SRN MOUNTAINS AND FOOTHILLS. STABLE CONDITIONS CONTINUE THURSDAY KEEPING CONDITIONS DRY AND WINDS UPSLOPE/DOWNSLOPE INDUCED. VERTICAL PROFILES INDICATE WINDS BELOW 600 MB WILL BE VERY LIGHT - LESS THAN 15 KTS AND NEAR NON- EXISTENT AT THE SURFACE ON THURSDAY...WITH THE EXCEPTION OF THE SOUTHWEST COLORADO VALLEYS WHERE WINDS ALOFT AT 300 MB ARE STILL 40 KTS THROUGH THURSDAY EVENING SO SOME HIGHER GUSTS (TO 20 MPH OR SO) MAY MIX DOWN TO THE SURFACE. TEMPERATURES WILL REMAIN ABOVE NORMAL. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 215 PM MDT WED SEP 9 2015 VERY LITTLE CHANGE IN THE MID RANGE FORECAST PERIOD AS HIGH PRESSURE PERSISTS. ALONG THE WEST COAST...A TROUGH DEVELOPS ON SATURDAY AND WHAT HAPPENS WITH THIS SYSTEM IS OUR NEXT FORECAST CHALLENGE. THE 12Z GFS INDICATES A SMALL CLOSED LOW DEVELOPING IN SOUTHERN UTAH AND PROPAGATING INTO WESTERN COLORADO ON MONDAY WHILE THE EC BRINGS AN OPEN WAVE TROUGH INTO THE FOUR CORNERS. BOTH SOLUTIONS BRING PRECIPITATION TO THE REGION...SO CONFIDENCE IS GOOD ON AN INCREASE IN MOISTURE AND THE POSSIBILITY OF RAIN EARLY NEXT WEEK. TUESDAY LOOKS QUITE BREEZY AND WET WITH EITHER MODEL SOLUTION AS A COLD 700 MB LOW PRESSURE SYSTEM BARRELS DOWN INTO THE NORTHERN ROCKIES ON TUESDAY INTERACTING WITH THE MUCH WARMER AIR IN PLACE TO THE SOUTH. THERE HAVE BEEN PRETTY MAJOR FLUCTUATIONS RUN TO RUN IN THE FORECAST MODELS FOR EARLY NEXT WEEK AS THE PATTERN TRANSITIONS...SO DETAILS WILL HAVE TO BE IRONED OUT AS A SOLUTION BECOMES MORE CONSISTENT. THE GENERAL PATTERN DOES LOOK WETTER AND COOLER NEXT WEEK WITH AN AUTUMN-LIKE LOOK TO THE PATTERN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1126 AM MDT WED SEP 9 2015 NO SIGNIFICANT WEATHER OR AVIATION HAZARDS ARE EXPECTED THROUGH THE TIME PERIOD. VFR AND MOSTLY P6SM SKC WITH LIGHT DIURNAL WIND CIRCULATIONS. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...NONE. UT...NONE. && $$ SHORT TERM...PF/JAM LONG TERM...JAM AVIATION...PF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1105 PM EDT THU SEP 10 2015 .SYNOPSIS... A FRONT WILL PUSH NORTH OVERNIGHT AND PROVIDE A FOCUS FOR LOCALLY HEAVY DOWNPOURS OVERNIGHT. LOW PRESSURE FROM THE MID-ATLANTIC WILL MOVE NORTHEAST ALONG THE FRONT PAST OUR AREA FRIDAY MORNING PULLING IT OUT TO SEA FOLLOWED BY WEAK HIGH PRESSURE THAT BRINGS A LULL IN THE WEATHER SATURDAY. WET-WEATHER RETURNS FOR SUNDAY BUT NOT A WASH- OUT. TURNING DRY AND WARMER INTO NEXT WEEK. POSSIBLE RECORD BREAKING HEAT INTO MID- TO LATE-SEPTEMBER AS ABOVE-AVERAGE TEMPS ARE FORECAST. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... 11 PM UPDATE... EXTENDED THE FLASH FLOOD WATCH ACROSS SOUTHERN RI AND SOUTHEAST MA THROUGH 6 AM. THIS IS THE AREA WHICH SAW THE HEAVIEST RAINFALL EARLIER TODAY...AND IS ALSO THE AREA IN LINE TO RECEIVE THE CONVECTION PRESENTLY OFF THE NJ COAST. WILL NEED TO SEE IF THIS AREA OF CONVECTION RETAINS ITS INTENSITY AS IT MOVES NORTH. THE FLOOD WATCH OVER THE REST OF SOUTHERN NEW ENGLAND CONTINUES UNTIL 6 AM AS WELL. TRYING TO PINPOINT THE PRECISE LOCATION FOR THE HEAVIEST RAINFALL TONIGHT IS VERY DIFFICULT. PRECIPITABLE WATER VALUES REMAIN HIGH FOR THIS TIME OF YEAR...ABOUT 1.7-2.0 INCHES. PRECIPITATION EFFICIENCY WILL BE MAXIMIZED OVERNIGHT...SO ANYWHERE COULD BE THE LOCATION WHICH SEES HEAVY RAINFALL. THUS...THE REASON FOR A WIDESPREAD WATCH. TWEAKED THE FORECAST THROUGH FRIDAY MORNING TO REFLECT OBSERVED TRENDS AND LATEST RUNS OF THE HIGH RESOLUTION GUIDANCE. INCREASED POPS SLIGHTLY...AND TRIED TO ADD MORE TIMING TO THE SHOWERS. PREVIOUS DISCUSSION... TWO AREAS OF FOCUS. THE FIRST IS ACROSS THE INTERIOR. INDICATIONS OF MID-LEVEL FRONTOGENESIS WILL BE ONGOING DURING THE OVERNIGHT HOURS. CAN SEE SOMEWHAT OF A BANDING SIGNATURE WITHIN THE BROADER RADAR LOOP MOVING INTO NEW ENGLAND FROM THE MID- TO UPPER-HUDSON VALLEY REGION OF NY. A FOCUS OF HIGHER PWAT OF NEARLY 2-INCHES AND THERE IS STILL THE LIKELIHOOD OF HEAVY RAIN ACROSS INTERIOR AREAS OF S NEW ENGLAND TO WARRANT THE FLASH FLOOD WATCH. FEEL THERE WILL BE A SQUEEZE...BUT DISPLACED FROM THE MORE FAVORABLE REGIONS OF THE RIGHT-REAR-QUADRANT OF THE UPPER-LEVEL-JET TO THE N...MAY NOT SEE SIGNIFICANT DEEP-LAYER LIFT. FOCUSED ACTIVITY LOOKS TO BE THE RESULT OF CONVERGENCE POTENTIALLY SUPPORTED BY VENTING ALOFT IN ADDITION TO FALLING HEIGHTS. SECOND AREA OF FOCUS IS OVER SE NEW ENGLAND. HIGHER THETA-E AIR AND ACCOMPANYING INSTABILITY AXIS. THIS IS WHERE LIKELY THUNDER WILL PROCEED DURING THE OVERNIGHT HOURS WITHIN THE ANTICYCLONIC BRANCH OF THE WARM-MOIST CONVEYOR BELT AS SYNOPTICALLY THIS IS AN OPEN-WAVE SYSTEM. NO REASON TO BELIEVE THIS WILL CURTAIL BACK CYCLONICALLY TOWARDS THE INTERIOR. PARENT WITH A H925-85 LOW- LEVEL-JET AND AREAS OF CONVERGENCE...THE HEAVIEST RAIN AND THE STRONGEST OF ACTIVITY LOOKS TO OCCUR HERE. MAY HAVE TO EXTEND THE FLASH FLOOD WATCH FOR SE NEW ENGLAND INTO THE MORNING HOURS. WILL LET THE OVERNIGHT CREW EVALUATE AND DECIDE TOWARDS THE EXPIRATION. OVERALL...A WELCOMING RAINFALL AS MUCH OF THE AREA HAS BEEN DRY SINCE MID-AUGUST. D0-D1 ABNORMAL TO MODERATE DROUGHT CONDITIONS HAVE BEEN FLAGGED ACROSS THE REGION. THIS BENEFICIAL RAIN SHOULD EASE SUCH DRY CONDITIONS AND BRING RESERVOIRS AND STREAMFLOWS BACK UP TO NEAR-NORMAL LEVELS. WILL KEEP IT MILD OVERNIGHT WITH THE LIKELIHOOD OF PATCHY FOG AND/OR LOW VISIBILITIES WITH ANY HEAVY RAIN ESPECIALLY ACROSS THE S/SE-COAST WITH HIGHER DEWPOINT AIR IN THE UPPER-60S TO LOW-70S. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... COASTAL LOW PRESSURE MOVES OFF TO THE EAST FRIDAY MORNING...CARRYING ANY REMAINING PCPN OFF TO THE EAST. MODEL MOISTURE FIELDS SHOW DRYING FROM WEST TO EAST DURING THE DAY...SUGGESTING A CLEARING TREND FRIDAY AFTERNOON INTO FRIDAY NIGHT. MEANWHILE...A LARGER UPPER SHORTWAVE DIGS OVER THE GREAT LAKES AND MAINTAINS A SOUTHWEST FLOW ALOFT. THE SUPPORTING UPPER JET WILL BE POSITIONED OVER THE EASTERN GREAT LAKES...GENERATING MORE CONVECTION IN THAT AREA WHILE NEW ENGLAND HAS WEAK SUBSIDENCE. SO FRIDAY AFTERNOON AND NIGHT SHOULD BE A DRY PERIOD. NORTH WIND FRIDAY WILL DIMINISH FRIDAY NIGHT INLAND. && .LONG TERM /SATURDAY THROUGH THURSDAY/... */ HIGHLIGHTS... - KEEPING IT DRY ON SATURDAY - WET WEATHER FOR SUNDAY BUT NOT LOOKING LIKE A WASHOUT EVERYWHERE - HEAVY RAIN THOUGH MAY IMPACT SE NEW ENGLAND ...HIGH TERRAIN - DRY AND WARM INTO NEXT WEEK ...POSSIBLE RECORD BREAKING HEAT */ DISCUSSION... KEEPING WITH AN ENSEMBLE APPROACH. H5 DEEP-TROUGH CLOSED LOW SWEEPS THROUGH THE OHIO-RIVER VALLEY SATURDAY AHEAD OF WHICH THERE IS RIDGE- AMPLIFICATION KEEPING US MOSTLY DRY WITH LIKELY SOME MID-HIGH LEVEL CLOUDS ACROSS THE REGION. LIFTING E SUNDAY DIFFLUENCE PROCEEDS ABOVE LOW-MID LEVEL LIFT / CONVERGENCE BUT CONVINCED S NEW ENGLAND IS IN AN AREA OF LESS FAVORABLE DEVELOPMENT. TWO AREAS OF INTEREST: THE CYCLONIC TROWALING ROUND THE CLOSED LOW BACK INTO THE E GREAT LAKES WHERE DEFORMATION PROCEEDS...AND SE NEW ENGLAND AND POINTS OFFSHORE WITHIN THE ANTI-CYCLONIC BRANCH OF THE WARM CONVEYOR BELT WHERE HIGH THETA-E VALUES RESIDE BENEATH DIFFLUENCE AND ENHANCED ASCENT WITH CONVERGENCE ALONG A STRONG H925-7 JET. S NEW ENGLAND BELOW THE RIGHT- FRONT-QUADRANT OF THE UPPER-LEVEL-JET AND IN THE CROSS-HAIRS OF A MID-LEVEL DRY-PUNCH WRAPPING INTO THE OCCLUDING SYSTEM PER ENSEMBLE MEANS LOOKS TO RESULT IN LITTLE OUTCOME OVER THE AREA. IN OTHER WORDS...NOT APPEARING TO BE A WASHOUT ON SUNDAY. CAN NOT RULE OUT HIGHER AMOUNTS OVER THE HIGHER TERRAIN. WITH ENSEMBLES LIFTING THE TROWAL N OF THE REGION SUNDAY NIGHT INTO MONDAY...LESS CONFIDENCE OF OUTCOMES ON MONDAY BENEATH THE COLD POOL AS THE TROUGH MAY MOVE THRU PRIOR TO BOUNDARY-LAYER DESTABILIZATION. PERHAPS SOME ACTIVITY UP AGAINST THE W-SLOPES OF HIGHER TERRAIN N OF OUR AREA WITH W-WIND CONVERGENCE. FOR THE REMAINDER OF THE WEEK...CONSISTENT SIGNALS OF RIDGING. THINK HEAT AND HUMIDITY BUILD BACK INTO THE REGION. AGREE WITH THE CLIMATE PREDICTION CENTER WITH ABOVE-AVERAGE TEMPERATURES. ENSEMBLES SIGNAL ANOMALOUS H85 TEMPERATURES ACROSS THE REGION. THINKING THAT WE COULD BREAK SOME RECORD HIGH TEMPERATURES INTO MID- TO LATE-SEPTEMBER. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY NIGHT/... TONIGHT...MODERATE CONFIDENCE. CONFIDENT MVFR-VLIFR MIX WITH CIGS. LOWER CONFIDENCE WITH VSBYS BUT EXPECT IFR WITH RA/+RA. FOG ALONG WITH LIFR-VLIFR CIGS LIKELY AN ISSUE FOR S/SE-COASTAL TERMINALS ALONG WITH A GREATER PROPENSITY OF FOG. WILL LEAN HIGHER TSRA CHANCES TOWARDS THE S/SE-COASTAL TERMINALS PREVAILING WITH VCTS. E/NE-WINDS BACKING OUT OF THE N TOWARDS MORNING. FRIDAY...MODERATE CONFIDENCE. IMPROVEMENT BEGINNING DURING THE MORNING TOWARDS VFR. NE-WINDS INCREASING AND GUSTING TO 20 KTS ALONG THE COASTS. FRIDAY NIGHT...HIGH CONFIDENCE. EXPECT MVFR-LIFR FOG DEVELOPMENT ESPECIALLY OVER THE INTERIOR TOWARDS MORNING. TYPICALLY PRONE TERMINALS WITHIN SHELTERED VALLEYS LIKELY TO EXPERIENCE LIGHT WINDS OVERNIGHT LIKE THE CT- RIVER VALLEY ESPECIALLY PRONE. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. WILL KEEP THUNDER OUT OF THE TAF OVERNIGHT EXPECTING IT TO REMAIN E/SE OFFSHORE. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK /SATURDAY THROUGH TUESDAY/... SATURDAY...HIGH CONFIDENCE. VFR. WINDS VEERING E/SE. A MAINLY DRY FORECAST. SATURDAY NIGHT - SUNDAY NIGHT...MODERATE CONFIDENCE. MVFR-IFR MIX WITH E/SE-ONSHORE FLOW BACKING SW TOWARDS THE END OF THE FORECAST PERIOD. RAIN LIKELY ACROSS THE REGION. PATCHY FOG POSSIBLE. MAY ALSO CONTEND WITH SOME LLWS IMPACTS. MONDAY INTO TUESDAY...MODERATE CONFIDENCE. VFR. W/SW-WINDS WITH GUSTS UP TO 20 KTS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY NIGHT/...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN SPECIFIC TIMING. 11 PM UPDATE...NO MAJOR CHANGES. TONIGHT...INCREASING COVERAGE IN SHOWERS AND THUNDERSTORMS. LOCALLY HEAVY DOWNPOURS POSSIBLE. AREAS OF POOR VISIBILITY IN FOG ESPECIALLY AROUND NANTUCKET FRIDAY...LOW PRESSURE LIFTING NE ACROSS THE WATERS. SHOWERS AND AREAS OF FOG START THE DAY. INCREASING NORTH WINDS WILL REACH 20 KNOTS ON OUR EASTERN WATERS AND COULD GET AS STRONG AS 25 KT. THE N-NE FETCH SHOULD BE ENOUGH TO BUILD SEAS ON THE EXPOSED EASTERN WATERS TO 5 FEET...POSSIBLY 6. A SMALL CRAFT ADVISORY HAS BEEN POSTED ON THE OUTER WATERS AND IN MASS BAY...PRIMARILY FOR SEAS BUT WITH AN EYE TOWARD THE WINDS AS WELL. FRIDAY NIGHT...MODERATE CONFIDENCE. DIMINISHING NORTH TO NORTHWEST WINDS WITH SEAS SUBSIDING AFTER MIDNIGHT. OUTLOOK /SATURDAY THROUGH TUESDAY/... SATURDAY...MODERATE CONFIDENCE. A LULL IN THE WEATHER. WINDS BECOME LIGHT WHILE VEERING E/SE. SHOULD SEE SEAS SUBSIDE FOR THE PERIOD BELOW 5-FEET. SUNDAY...MODERATE CONFIDENCE. DEEPER AREA OF LOW PRESSURE TO THE W. WILL SEE AN ACCOMPANYING WARM FRONT LIFT N ACROSS THE WATERS BRINGING WITH IT RAIN ALONG WITH INCREASING E/SE-ONSHORE WINDS. GUSTS UP TO 20 KTS. WAVE HEIGHTS BUILDING IN EXCESS OF 5-FEET INITIALLY OVER THE S WATERS EXPANDING TO THE E/SE WATERS LATE IN THE PERIOD. MONDAY...MODERATE CONFIDENCE. IMPROVING. WINDS BACK OUT OF THE W/SW AND REMAIN ROBUST WITH A STRONG AREA OF LOW PRESSURE SITUATED WELL TO THE W ACROSS THE INTERIOR. ANOTHER DAY OF GUSTS UP TO 20 KTS WHILE SEAS REMAIN AT OR IN EXCESS OF 5-FEET ON THE WATERS. && .HYDROLOGY... 7 PM UPDATE... RAINFALL RATES TODAY HAVE BEEN EFFICIENT AT TIMES WITH 2 TO 4 INCHES PER HOUR. FEEL THIS RISK PERSISTS THROUGH THE OVERNIGHT ESPECIALLY THOSE AREAS OF HIGHER THETA-E WHICH ARE FORECAST TO PREVAIL OVER SE NEW ENGLAND. NEVERTHELESS...CONVERGENCE ALONG A FRONTAL BOUNDARY OVER THE INTERIOR OF A 2-INCH PWAT AIRMASS IS LIKELY TO LEAD TO LOCALIZE EFFICIENCY OF HEAVY RAIN. NOT ABSOLUTELY CERTAIN ON THE SPECIFICS AS TO WHERE...BUT A SW-NE BAND IS EXPECTED ACROSS THE INTERIOR WARRANTING THE CONTINUATION OF THE FLASH FLOOD WATCH. WITH SE NEW ENGLAND UNDER THE FAVORABLE ENVIRONMENT OF HIGHER THETA-E AIR ACCOMPANIED WITH INSTABILITY AND A LOW-LEVEL-JET AND AREAS OF LOCALIZED CONVERGENCE...THE PROPENSITY FOR HEAVY RAIN ALONG WITH THUNDERSTORMS IS GREATER. MAY NEED TO EXPAND THE FLASH FLOOD WATCH FOR SE NEW ENGLAND PAST MIDNIGHT INTO THE MORNING HOURS. WILL ALLOW THE OVERNIGHT SHIFT TO RE-EVALUATE AND AMEND AS NECESSARY. EFFICIENT HEAVY RAINFALL PRODUCERS AS WE HAVE SEEN EARLIER TODAY LEAD TO FLASH FLOODING...ESPECIALLY MORE SO NOW FOR AREAS THAT HAVE ALREADY BECOME WELL-SATURATED FOR THE DAY. SUBSEQUENTLY THIS EMPHASIZES THE NECESSARY CONTINUATION OF THE FLASH FLOOD WATCH. SEE THE UPDATED DISCUSSION AT THE TOP OF THE AFD FOR FURTHER DETAILS. NEAR-TERM HIGH-RES GUIDANCE SUCH AS THE HRRR AND RAP WERE UTILIZED IN MAKING THE DETERMINATIONS TO THE FORECAST OVER THE NEXT 12 HOURS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FLASH FLOOD WATCH UNTIL 6 AM EDT FRIDAY FOR CTZ002>004. MA...FLASH FLOOD WATCH UNTIL 6 AM EDT FRIDAY FOR MAZ002>022-026. RI...FLASH FLOOD WATCH UNTIL 6 AM EDT FRIDAY FOR RIZ001>007. MARINE...SMALL CRAFT ADVISORY FROM 2 AM FRIDAY TO 6 AM EDT SATURDAY FOR ANZ250-254. SMALL CRAFT ADVISORY FROM 5 AM TO 4 PM EDT FRIDAY FOR ANZ251. SMALL CRAFT ADVISORY FROM 2 PM FRIDAY TO 2 AM EDT SATURDAY FOR ANZ255-256. && $$ SYNOPSIS...WTB/SIPPRELL NEAR TERM...WTB/BELK SHORT TERM...WTB LONG TERM...SIPPRELL AVIATION...WTB/BELK/SIPPRELL MARINE...WTB/BELK/SIPPRELL HYDROLOGY...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
335 PM EDT WED SEP 9 2015 .SYNOPSIS... A COLD FRONT WILL SLOWLY MOVE INTO THE REGION TONIGHT BEFORE STALLING NEAR THE SOUTH COAST THURSDAY. LOW PRESSURE WILL TRACK SOUTH OF NEW ENGLAND THURSDAY INTO FRIDAY BRINGING WIDESPREAD SHOWERS AND SOME THUNDERSTORMS...ALONG WITH HEAVY RAINFALL AT TIMES. AS AN AREA OF LOW PRESSURE DEPARTS ON FRIDAY...A LULL IN THE WEATHER WILL FOLLOW PRIOR TO AN ANOMALOUS WEATHER SYSTEM FOR THE WEEKEND WHICH WILL LIKELY BRING THE AREA SOME RAIN FOR SUNDAY. AS THE SYSTEM EXITS...MILDER WEATHER WILL FOLLOW WITH ABOVE- AVERAGE TEMPERATURES BENEATH HIGH PRESSURE INTO NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... RECORD MAX TEMP HAS BEEN SET AT BOS AND BDL. SO FAR PVD IS ONE DEGREE SHY OF THE RECORD. RADAR SHOWS WIDELY SCT SHOWERS AND PERHAPS AN EMBEDDED TSTM MOVING INTO W MA. MLCAPES CLOSE TO 1000 J/KG WITH EFFECTIVE SHEAR 30 KT SO CANT RULE OUT AN ISOLD STRONG STORM BUT HRRR WEAKENS THE CONVECTION AS IT MOVES EAST INTO A LESS FAVORABLE ENVIRONMENT. MORE WIDESPREAD CONVECTION AHEAD OF THE COLD FRONT WAS MOVING EAST FROM CENTRAL AND NORTHERN NY. THIS AREA WAS ASSOCD WITH DECENT LOW LEVEL FRONTOGENESIS AND MLCAPES UP TO 1000 J/KG. MODELS BRING THIS FRONTOGENESIS INTO THE REGION THIS EVENING BUT INSTABILITY IS FORECAST TO WEAKEN TOWARD 00Z SO WE EXPECT WEAKENING LINE OF CONVECTION MOVING INTO THE THE REGION FROM THE WEST AROUND OR AFT 00Z PER HIRES ARW/NMM. COLD FRONT MOVES SLOWLY EAST ACROSS SNE TONIGHT REACHING THE COASTAL PLAIN TOWARD 00Z. WE WILL LIKELY SEE A LULL IN ACTIVITY OVERNIGHT ALTHOUGH CANT RULE OUT A FEW SHOWERS OR AN ISOLD TSTM...ESPECIALLY COASTAL PLAIN LATER TONIGHT WITHIN THE LOW LEVEL THETA-E RIDGE AHEAD OF THE COLD FRONT. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... *** LOCALLY HEAVY RAINFALL LIKELY THURSDAY INTO THURSDAY NIGHT *** INSTABILITY AXIS DEVELOPS ACROSS THE COASTAL PLAIN IN THE MORNING WITHIN THE THETA-E RIDGE AND WILL LIKELY SEE A GENERATION OF SHOWERS AND TSTMS ACROSS E CT...RI AND SE MA THU MORNING ALONG THE FRONTAL BOUNDARY. GIVEN PWATS INCREASING OVER 2 INCHES...LOCALLY HEAVY RAINFALL IS POSSIBLE. THE FRONT IS EXPECTED TO STALL NEAR THE SOUTH COAST AS LOW PRES DEVELOPS OVER THE MID ATLC COAST...THEN LIFTING NE AND TRACKING SOUTH OF NEW ENGLAND THU NIGHT. CLASSIC COLD SEASON SCENARIO WITH LOW LEVEL FRONTOGENESIS AND CONVERGENCE DEVELOPING ON THE NW PERIPHERY OF SFC LOW AND MID LEVEL CENTER WITHIN RIGHT ENTRANCE REGION OF THE UPPER JET. THE BEST LOW LEVEL FORCING BECOMES ALIGNED ACROSS W NEW ENG SO WE EXPECT FOCUS FOR HEAVIER RAINFALL TO SHIFT TO THE WEST ACROSS W MA AND N CT DURING THU AFTERNOON INTO THU NIGHT...EVENTUALLY REACHING THE COAST LATE THU NIGHT INTO EARLY FRI. SFC INSTABILITY IS LIMITED IN THE WEST ON THE COOL SIDE OF THE BOUNDARY BUT THERE IS ENOUGH ELEVATED INSTABILITY FOR A FEW TSTMS. ANOMALOUS PWATS SUGGEST LOCALLY HEAVY RAINFALL WILL BE THE PRIMARY THREAT WITH AREAS OF URBAN AND POOR DRAINAGE FLOODING POSSIBLE. RAINFALL AMOUNTS OF 1 TO 2 INCHES WITH LOCALLY HIGHER AMOUNTS POSSIBLE WITH AXIS OF HEAVIEST RAINFALL LIKELY ACROSS WESTERN NEW ENGLAND. LESSER RAINFALL AMOUNTS EXPECTED IN SE NEW ENG. MUCH COOLER THU WITH MAX TEMPS MOSTLY IN THE 70S...BUT MAY REACH 80 ACROSS PORTIONS OF RI AND E MA. STILL QUITE HUMID IN E NEW ENG WITH DEWPOINTS NEAR 70. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... HIGHLIGHTS... * SHOWERS DISSIPATING THROUGH THE DAY FRIDAY * A LULL IN THE WEATHER AROUND SATURDAY * RETURN OF WET-WEATHER AND POSSIBLE THUNDERSTORMS FOR SUNDAY * LOOKING DRY WITH ABOVE- AVERAGE TEMPERATURES INTO NEXT WEEK DISCUSSION... AN ANOMALOUS WEEKEND SETUP INTO EARLY NEXT WEEK THAT WARRANTS AN ENSEMBLE FORECAST APPROACH. GOOD AGREEMENT ON A DEEP TROUGH PATTERN EVOLVING INTO A QUASI CUT-OFF CLOSED LOW OVER THE OHIO RIVER VALLEY REGION OVER THE WEEKEND...DEAMPLIFYING AS AN OPEN-WAVE OVER THE NE EARLY NEXT WEEK. THEREAFTER ENSEMBLE MEANS CONTINUE TO ADVERTISE RIDGING ACROSS THE REGION WITH PREFERRED TROUGHING TO THE W AND A MAINTAINED AREA OF LOW PRESSURE OVER THE N ATLANTIC. APPEARANCES WOULD LEAD TO BELIEVE THAT SUMMER IS NOT OVER QUITE YET AS THE 8-14 DAY FORECASTS FROM THE CLIMATE PREDICTION CENTER HAVE INCREASED ABOVE-AVERAGE TEMPERATURE PROBABILITY. NORMALS FOR MID-SEPTEMBER ARE AROUND THE LOW- TO MID-70S FOR HIGHS WITH LOW- TO MID-50S FOR LOWS. FRIDAY INTO SATURDAY... SOME INITIAL SHOWERS AND CLOUDY CONDITIONS TO START ON FRIDAY SHOULD BREAK W TO E AS DRIER AIR MOVES IN AND SUBSIDENCE PROCEEDS BENEATH RIDGING AHEAD OF THE CLOSED-LOW OVER THE OHIO RIVER VALLEY EXPECT A LULL IN THE WEATHER-ACTIVITY FRIDAY INTO SATURDAY...THOUGH UNCERTAIN AS TO WHEN IT WILL RE-EMERGE SATURDAY INTO SUNDAY. IT DOES APPEAR BASED ON ENSEMBLE MEANS THAT THE RIDGE LIFTS NE SATURDAY-SUNDAY AS THE CLOSED LOW IS RECAPTURED BY THE MARITIME FLOW DEAMPLIFYING AS AN OPEN-WAVE MONDAY-TUESDAY. PROGRESS OF AN ACCOMPANYING WARM- FRONTAL BOUNDARY ALONG WHICH THERE IS AN INCREASING UPSLOPE MAGNITUDE OF HIGHER THETA-E AIR BENEATH GROWING DIFFLUENCE ALOFT WARRANTS CHANCE POPS OVER THE MAJORITY OF THE AREA BEGINNING SATURDAY NIGHT. WILL GO AHEAD WITH SOME ELEVATED THUNDER CHANCES BUT KEEP THEM ISOLATED AS INSTABILITY APPEARS MARGINAL IN A MODERATELY SHEARED ENVIRONMENT. SUNDAY INTO MONDAY... LIKELY RAIN WITH EMBEDDED THUNDER AND HEAVIER SHOWERS AS AN ENHANCED H925-85 FLOW WRAPS CYCLONICALLY AROUND THE DEAMPLIFYING CLOSED-LOW NE OF THE REGION. A QUASI-TROWALING SETUP COLLOCATED WITH STRONG CONVERGENT ISENTROPIC-UPSLOPE SIGNATURES BENEATH DIFFLUENCE ALOFT... THE POTENTIAL FLY-IN-THE-OINTMENT COULD BE THE POSSIBILITY OF THE GREATER ENHANCED FORCING REMAINING W OF THE REGION ASSOCIATED WITH THE DEAMPLIFYING CLOSED-LOW OVER THE E GREAT LAKES AND/OR THE MODEL CONSENSUS OF NEW ENGLAND BEING BENEATH THE RIGHT-EXIT REGION OF THE UPPER-LEVEL JET...YIELDING A LESS FAVORABLE AREA OF LIFT. ASIDE...THE APPARENT LOW-MID LEVEL LIFT AND CONVERGENCE OF THETA-E YIELDS THE LIKELIHOOD OF RAIN. BUT THE QUICKLY-FOLLOWING PUNCH OF DRIER AIR WRAPPING INTO THE OCCLUDING SYSTEM MAKES THE WET-WEATHER PERIOD BRIEF. MOST OF THE ACTIVITY MAY RESIDE ON SUNDAY WITH DRY WEATHER PREVAILING SUNDAY NIGHT. ONLY A RENEWED CHANCE MAY EMERGE ON MONDAY ASSOCIATED WITH THE COMMA- HEAD TROWAL OF THE LOW WHERE H85-5 TEMPERATURES DROP CONSIDERABLY. H5 TEMPERATURES NEAR -20C. FOCUS ALONG A COLD FRONT AS POSSIBLY THE BOUNDARY-LAYER DESTABILIZES AHEAD SUBSEQUENT OF THE PUNCH OF DRY AIR COULD RESULT IN SOME LOW-TOPPED ACTIVITY. SOME SPATIAL VARIABILITY WITH RESPECT TO ATMOSPHERIC FEATURES THUS ONLY WILLING TO GO WITH CHANCE POPS MAINLY OUT TO THE W. WILL GO WITH AT OR BELOW-AVERAGE TEMPERATURES FOR THE PERIOD. PRESENTLY NOT SEEING MUCH IN THE WAY OF IMPACTS WITH RESPECT TO THE WET-WEATHER. HIGHER THETA-E VALUES LOOK TO REMAIN OFFSHORE WITHIN THE ANTICYCLONIC BRANCH OF THE WARM-CONVEYOR BELT...ALSO GREATER INSTABILITY. TUESDAY AND BEYOND... DRY WEATHER AS RIDGING PROCEEDS PER AN ENSEMBLE-WEIGHTED FORECAST. WILL LEAN TOWARDS AN ABOVE-AVERAGE TEMPERATURE FORECAST IN AGREEMENT WITH THE CLIMATE PREDICTION CENTER. CONTINUED STRONG SIGNALS OF SW- FLOW PREVAILING ALOFT ADVECTING NE ACROSS THE REGION A WARM-HUMID AIRMASS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY/... THROUGH 00Z...VFR. ISOLD SHOWERS OR PERHAPS A TSTM IN W NEW ENG. TONIGHT...MODERATE CONFIDENCE. AREAS OF IFR/LIFR STRATUS AND PATCHY FOG LIKELY DEVELOPING TONIGHT...ESPECIALLY NEAR THE S COAST. MOSTLY VFR ELSEWHERE WITH SOME PATCHY MVFR FOG IN SPOTS. WEAKENING LINE OF SHOWERS/TSTMS MOVING INTO W MA AND N CT THIS EVENING WITH LOW PROB OF A BRIEF SHOWER/TSTM IN THE COASTAL PLAIN OVERNIGHT. THURSDAY...MODERATE CONFIDENCE. IFR CONDITIONS ALONG THE S COAST IMPROVING TO MVFR/VFR. OTHERWISE...VFR GRADUALLY LOWERING TO MVFR AS SHOWERS AND SCT TSTMS DEVELOP. FOCUS FOR SHOWERS/TSTMS WILL INITIALLY BE ACROSS E CT/RI AND SE MA IN THE MORNING...THEN GRADUALLY SHIFTING INTO WESTERN NEW ENG IN THE AFTERNOON. LOCALLY HEAVY RAINFALL POSSIBLE. THURSDAY NIGHT...MODERATE CONFIDENCE. CONDITIONS LOWERING TO IFR IN SHOWERS/TSTMS AND PATCHY FOG. LOCALLY HEAVY RAINFALL POSSIBLE. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK /FRIDAY THROUGH MONDAY/... FRIDAY...MODERATE CONFIDENCE. MVFR-IFR MIX ALONG WITH -SHRA LIFTS E ALLOWING CONDITIONS TO IMPROVE THROUGH THE DAY. N-WINDS WITH THE POSSIBILITY OF 20 KT GUSTS ACROSS THE E-COAST. SATURDAY...MODERATE CONFIDENCE. VFR. WINDS VEERING E/SE. DRY FORECAST. SUNDAY...MODERATE CONFIDENCE. MVFR-IFR MIX WITH E/SE-ONSHORE FLOW. RAIN LIKELY ACROSS THE REGION. MAY ALSO CONTEND WITH SOME LLWS IMPACTS. MONDAY...MODERATE CONFIDENCE. IMPROVING TO VFR BEGINNING SUNDAY NIGHT. W/SW-WINDS WITH GUSTS UP TO 20 KTS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/...HIGH CONFIDENCE. STILL EXPECT SOME G25 KT ACROSS NEARSHORE WATERS NEAR CAPE COD THROUGH THE REST OF THE AFTERNOON ASSOCD WITH MODEST LOW LEVEL JET SO WE WILL CONTINUE THE SMALL CRAFT ADVISORY. THE JET MOVES EAST TONIGHT AND WINDS WILL DIMINISH. VSBYS LOWERING IN PATCHY FOG TONIGHT S COASTAL WATERS. THU...WINDS BECOME NE LESS THAN 20 KT ACROSS E MA COASTAL WATERS AS FRONT MOVES THROUGH BUT REMAINING S/SE OVER SOUTHERN WATERS. VSBYS REDUCED IN SHOWERS AND POSSIBLE TSTMS AND FOG...ESPECIALLY IN THE MORNING. THU NIGHT...MAINLY E/NE WINDS BELOW SCA...BUT THERE IS LOW PROB OF GUSTY NE WINDS DEVELOPING LATE ACROSS NE MA COASTAL WATERS. VSBYS REDUCED AT TIMES IN SHOWERS/POSSIBLE TSTMS AND FOG. OUTLOOK /FRIDAY THROUGH MONDAY/... FRIDAY...MODERATE CONFIDENCE. LOW PRESSURE LIFTING E. SHOWERS LINGER ACROSS THE WATER ALONG WITH THE POSSIBILITY OF FOG. N-WINDS PREVAILING BACKING OUT OF THE NW. INITIALLY COULD SEE GUSTS UP TO 25 KTS ACROSS THE E-WATERS LENDING TO SEAS IN EXCESS OF 5-FEET. SMALL-CRAFT ADV MAY BE WARRANTED. SATURDAY...MODERATE CONFIDENCE. A LULL IN THE WEATHER. WINDS BECOME LIGHT WHILE VEERING E/SE. SHOULD SEE SEAS SUBSIDE FOR THE PERIOD BELOW 5-FEET. SUNDAY...MODERATE CONFIDENCE. DEEPER AREA OF LOW PRESSURE TO THE W. WILL SEE AN ACCOMPANYING WARM FRONT LIFT N ACROSS THE WATERS BRINGING WITH IT THE CHANCE OF RAIN ALONG WITH INCREASING E/SE-ONSHORE WINDS. GUSTS UP TO 20 KTS POSSIBLE. WAVE HEIGHTS BUILDING IN EXCESS OF 5-FEET PLAUSIBLE. MONDAY...MODERATE CONFIDENCE. THOUGH IMPROVING SUNDAY NIGHT...WINDS BACK OUT OF THE W/SW AND REMAIN ROBUST WITH A STRONG AREA OF LOW PRESSURE SITUATED WELL TO THE W ACROSS THE INTERIOR. ANOTHER DAY OF GUSTS UP TO 20 KTS WHILE SEAS REMAIN AT OR IN EXCESS OF 5-FEET ON THE WATERS. && .CLIMATE... RECORD HIGH TEMPERATURES FOR WEDNESDAY...9/9 BOS...91 IN 1971 PVD...91 IN 1971 ORH...90 IN 1915 BDL...91 IN 2002 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ231>234. SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR ANZ250. && $$ SYNOPSIS...KJC/SIPPRELL NEAR TERM...KJC SHORT TERM...KJC LONG TERM...SIPPRELL AVIATION...KJC/SIPPRELL MARINE...KJC/SIPPRELL CLIMATE...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
148 PM EDT WED SEP 9 2015 .SYNOPSIS... HIGH PRESSURE SOUTH OF NEW ENGLAND WILL PUSH OFFSHORE LATE TODAY THROUGH THURSDAY. A COLD FRONT WILL APPROACH LATE THIS AFTERNOON...SLOWLY CROSSING THE REGION TONIGHT AND THURSDAY...BEFORE STALLING ACROSS SOUTHEAST MASSACHUSETTS BY THURSDAY NIGHT. EXPECTING WIDESPREAD SHOWERS AND SOME THUNDERSTORMS...ALONG WITH HEAVY RAINFALL AT TIMES...WHICH MAY CAUSE LOCALIZED FLOODING THURSDAY NIGHT INTO FRIDAY. A BRIEF LULL FOLLOWS FOR SATURDAY PRIOR TO ANOTHER POTENTIAL BATCH OF RAIN SUNDAY INTO MONDAY. A WARM AND DRY PATTERN LOOKS TO PREVAIL INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 145 PM UPDATE... RECORD MAX TEMP HAS BEEN SET AT BOS AND TIED AT BDL. SO FAR PVD IS ONE DEGREE SHY OF THE RECORD. RADAR SHOWS WIDELY SCT SHOWERS ACROSS E NY WITH MORE WIDESPREAD CONVECTION IN THE FORM OF A LINE ACROSS CENTRAL AND N NY ASSOCD WITH THE COLD FRONT. HRRR SHOWS A FEW SHOWERS AND PERHAPS A TSTM SPILLING INTO W NEW ENG MID/LATE AFTERNOON...BUT MAIN ACTIVITY ASSOCD WITH GOOD LOW LEVEL FRONTOGENESIS REMAINS TO THE WEST. MLCAPES UP TO 1000 J/KG ACROSS FAR W NW ENG AND E NY BUT INSTABILITY IS FORECAST TO WEAKEN RAPIDLY TOWARD 00Z SO EXPECT WE EXPECT WEAKENING LINE OF CONVECTION MOVING INTO THE REGION AROUND OR AFT 00Z. PREVIOUS DISCUSSION... STILL SOME STRATUS ALONG THE IMMEDIATE S COAST WHICH MAY TAKE UNTIL THE AFTERNOON TO BURN OFF...OTHERWISE MOSUNNY AND ANOTHER HOT/HUMID DAY. NOT QUITE AS HOT AS YESTERDAY...BUT MAXES WILL LIKELY REACH INTO THE LOWER 90S IN NE MA AND PORTIONS OF THE CT VALLEY AND WELL INTO THE 80S ELSEWHERE. BEST CHANCE OF AT LEAST TYING RECORD MAXES WILL BE AT BOS/BDL. IT WILL BE QUITE HUMID WITH DEWPOINTS UPPER 60S TO LOWER 70S SO HEAT INDICES WILL GET INTO THE LOW AND MID 90S. MODEST SW LOW LEVEL JET WILL LIKELY RESULT IN SOME GUSTS TO 25 MPH ACROSS SE NEW ENG. WEDGE OF VERY DRY MID LEVEL AIR ACROSS SNE THIS MORNING WILL MOVE OFFSHORE WITH COLUMN MOISTENING THROUGH THE AFTERNOON. AIRMASS DESTABILIZES WITH CAPES UP TO 1000 J/KG IN W NEW ENG AHEAD OF COLD FRONT WHICH MOVES THROUGH NEW YORK STATE THIS AFTERNOON. HI-RES GUIDANCE SUGGESTS A FEW SHOWERS/TSTMS COULD SPILL INTO W MA VERY LATE TODAY SO WILL HAVE SLIGHT CHC POPS IN THE AREA. 0-6KM SHEAR INCREASES TO ABOUT 25 KT SO AN ISOLD STRONG STORM IS POSSIBLE BUT SEVERE WEATHER NOT ANTICIPATED. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... COLD FRONT SLOWLY MOVES INTO THE REGION TONIGHT THROUGH MIDDAY THU...THEN WILL STALL ACROSS SOUTHEASTERN AREAS BY THU EVENING. WITH STEADY S-SW WIND FLOW IN PLACE...WILL SEE INCREASING MOISTURE FEED UP THE COAST. PWATS INCREASE UP TO 2 INCHES...SO WILL LIKELY SEE HEAVY RAINFALL ESPECIALLY ON THU AS THE FRONT SLOWS. WILL STILL SEE SOME MARGINAL INSTABILITY IN PLACE...SO SOME ISOLD CONVECTION REMAINS POSSIBLE. NOTING CAPES ACROSS NE CT/RI/SE MA AT AROUND 700- 800 J/KG...SO MIGHT SEE SOME GUSTY WINDS IN ANY THUNDERSTORMS THERE DURING THURSDAY AFTERNOON. EXPECT HIGHS ON THU RANGING FROM THE MID 70S WELL INLAND TO THE LOWER 80S ACROSS SE AREAS. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... HIGHLIGHTS... * POTENTIAL FOCUSED AREA OF HEAVY RAIN THURSDAY NIGHT INTO FRIDAY * THREAT OF URBAN / POOR-DRAINAGE FLOODING OVER NEW ENGLAND * A LULL PRIOR TO RENEWED ACTIVITY SUNDAY INTO MONDAY * LOOKING DRY AND WARMER INTO NEXT WEEK DISCUSSION... THURSDAY NIGHT THROUGH FRIDAY... 09/00Z GUIDANCE SUITE HAS NOT CHANGED MUCH FROM PREVIOUS THINKING. PLENTY OF SYNOPTIC FORCING SHOULD MEAN WIDESPREAD SHOWERS ACROSS SOUTHERN NEW ENGLAND FOR A PORTION OF THIS TIME PERIOD. HAVE HIGH CONFIDENCE IN MEASURABLE RAINFALL ACROSS MOST OF SOUTHERN NEW ENGLAND. STILL NEED TO IRON OUT WHAT THE UPPER LIMIT FOR RAINFALL WILL BE...AND WHERE IT WILL FALL. AT THIS POINT...IT STILL APPEARS THE AXIS FOR HEAVIEST RAINFALL WILL EXTEND NORTHEAST ACROSS NORTHERN CT AND WESTERN AND CENTRAL MA. THE MAJORITY OF RIVERS AND STREAMS ARE WELL BELOW NORMAL WITH RESPECT TO STREAMFLOWS. AS LAKES AND RESERVOIRS ARE ALSO LOW...THE SUBSEQUENT FOCUS REMAINS UPON URBAN AND POOR-DRAINAGE FLOODING. CONVECTIVE INSTABILITY LOOKS RATHER MARGINAL...SO NOT EXPECTING MANY STRONG THUNDERSTORMS. CANNOT COMPLETELY RULE OUT THAT POSSIBILITY THOUGH. NEAR SEASONABLE TEMPERATURES. THIS WEEKEND INTO EARLY NEXT WEEK... FAIRLY GOOD AGREEMENT AMONG THE 09/00Z MODELS HEADING INTO THIS WEEKEND...BREAKS DOWN TO SOME EXTENT SUNDAY INTO MONDAY. THE MAIN ISSUE WILL BE THE PROGRESS OF A MODEST UPPER LOW...AND HOW EFFECTIVE IT WILL BE TO SPAWN A COASTAL LOW OFF THE MID ATLANTIC COAST. BOTH THE GFS AND ECMWF HAVE A POTENT SHORTWAVE IN PLACE TO GENERATE THIS LOW PRESSURE...BUT HAVE RATHER DIFFERENT IDEAS ON ITS TRACK AND TIMING. HAVE MODERATE CONFIDENCE WE WILL SEE A PERIOD OF SHOWERS SOMETIME SUNDAY INTO MONDAY. HAVE LOW CONFIDENCE IN THE PRECISE TIMING. WILL JUST MENTION A CHANCE FOR SHOWERS SUNDAY INTO MONDAY...AND AWAIT FURTHER CLUES ON HOW THIS WINDOW COULD BE NARROWED IN LATER FORECASTS. NEXT WEEK... ENSEMBLE SOLUTIONS SIGNALING A RETURN TO A RIDGING PATTERN. COULD BE LOOKING AT ANOTHER PRONOUNCED HOT AND HUMID PERIOD...AS HIGH PRESSURE BUILDS S/E OF THE REGION. STILL HAVE RATHER LOW CONFIDENCE IN THE FORECAST DETAILS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY/... THROUGH 00Z...VFR. ISOLD SHOWERS OR PERHAPS A TSTM IN W NEW ENG. TONIGHT...MODERATE CONFIDENCE. AREAS OF IFR/LIFR STRATUS AND PATCHY FOG LIKELY DEVELOPING TONIGHT...ESPECIALLY NEAR THE S COAST. MOSTLY VFR ELSEWHERE WITH SOME PATCHY MVFR FOG IN SPOTS. WEAKENING LINE OF SHOWERS/TSTMS MOVING INTO W MA AND N CT THIS EVENING WITH LOW PROB OF A BRIEF SHOWER/TSTM IN THE COASTAL PLAIN OVERNIGHT. THURSDAY...MODERATE CONFIDENCE. IFR CONDITIONS ALONG THE S COAST IMPROVING TO MVFR/VFR. OTHERWISE...VFR GRADUALLY LOWERING TO MVFR AS SHOWERS AND SCT TSTMS DEVELOP. FOCUS FOR SHOWERS/TSTMS WILL INITIALLY BE ACROSS E CT/RI AND SE MA IN THE MORNING...THEN GRADUALLY SHIFTING INTO WESTERN NEW ENG IN THE AFTERNOON. LOCALLY HEAVY RAINFALL POSSIBLE. THURSDAY NIGHT...MODERATE CONFIDENCE. CONDITIONS LOWERING TO IFR IN SHOWERS/TSTMS AND PATCHY FOG. LOCALLY HEAVY RAINFALL POSSIBLE. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/... THURSDAY NIGHT INTO FRIDAY...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN TIMING. A MIX OF LOW-END VFR TO IFR. IFR...ESPECIALLY WITH +RA/TSRA FORECAST. S FLOW BACKING N OVER TIME. IMPROVING FRIDAY NIGHT. SATURDAY...MODERATE CONFIDENCE. VFR. WINDS VEERING E/SE. SUNDAY...LOW CONFIDENCE. LOW-END VFR TO IFR WITH INCREASING CHANCES OF RAIN. E WINDS INCREASE...THEN BACK W/NW WITH TIME. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY/...HIGH CONFIDENCE. 1015 AM UPDATE... WE EXPANDED THE SCA TO THE NEARSHORE WATERS ADJACENT TO CAPE COD WHERE A FEW G25 KT EXPECTED THROUGH THE AFTERNOON. SW WINDS WILL CONTINUE THROUGH THE PERIOD. WILL SEE GUSTS UP TO 25 KNOTS AND SEAS AROUND 5 FT ON THE EASTERN OUTER WATERS THIS AFTERNOON THROUGH AROUND MIDNIGHT TONIGHT. SMALL CRAFT HAS BEEN ISSUED FOR THIS AREA. SOME GUSTS TO AROUND 20 KT POSSIBLE THIS AFTERNOON AND EVENING ALONG THE S COASTAL NEAR SHORE WATERS. WINDS BECOME LIGHT S-SW THOUGH MAY BE ONSHORE ALONG THE EASTERN NEAR SHORE WATERS THU. PATCHY FOG DEVELOPS TONIGHT WITH REDUCED VSBYS. SHOWERS DEVELOP FROM S-N OVERNIGHT TONIGHT...WITH LOW RISK OF ISOLD TSTMS. BEST SHOT FOR SHOWERS/ISOLD TSTMS WILL OCCUR DURING THU. FOG WILL ALSO LINGER. OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/... THURSDAY NIGHT INTO FRIDAY...MODERATE CONFIDENCE. LOW PRESSURE SHOULD PASS ACROSS SOUTHERN NEW ENGLAND. INCREASING SOUTH WINDS AHEAD OF THIS LOW COULD GENERATE SEAS APPROACHING 5 FEET ON THE E WATERS FOR THE LATE THURSDAY INTO FRIDAY PERIOD. IT IS MORE LIKELY THESE BUILDING SEAS WILL DEVELOP IN THE NORTHEAST FETCH ONCE THIS LOW PRESSURE IS FARTHER OFFSHORE. WILL SEE SOME IMPROVEMENT INTO SATURDAY MORNING. SATURDAY...MODERATE CONFIDENCE. WINDS VEERING E/SE. GOOD BOATING WEATHER PREVAILS WITH SEAS BELOW 5 FEET. SUNDAY...LOW CONFIDENCE. ANOTHER AREA OF LOW PRESSURE AND RAIN. TRACK UNCERTAIN. COULD SEE IMPACTS ON THE WATERS...THOUGH THEY MAY REMAIN MORE SOUTH AND EAST COMPARED TO THURSDAY-FRIDAY. && .CLIMATE... RECORD HIGH TEMPERATURES FOR WEDNESDAY...9/9 BOS...91 IN 1971 PVD...91 IN 1971 ORH...90 IN 1915 BDL...91 IN 2002 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ231>234. SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR ANZ250. && $$ SYNOPSIS...BELK/EVT NEAR TERM...KJC SHORT TERM...EVT LONG TERM...BELK AVIATION...BELK/KJC MARINE...BELK/EVT CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
951 PM EDT THU SEP 10 2015 .SYNOPSIS... LOW PRESSURE WILL MOVE ALONG A FRONT OVER THE AREA AND OFF TO THE NORTHEAST TONIGHT. WEAK HIGH PRESSURE WILL BRIEFLY PUSH INTO THE AREA ON FRIDAY. ANOTHER AREA OF LOW PRESSURE DEVELOPS OVER THE SOUTHEASTERN PORTION OF THE NATION ON SATURDAY. THIS LOW WILL PUSH NORTHWARD THROUGH THE WEEKEND, BRINGING UNSETTLED WEATHER TO OUR AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTH ON MONDAY, PERSISTING THROUGH MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... THE STEADIER AND HEAVIER SHOWERS HAVE ENDED ACROSS MOST OF THE AREA WITH THE EXCEPTION OF THE PHILA AND ITS SOUTHERN SUBURBS. THE 00Z HRRR/RAP INITIALIZED THE 850 MB CLOSED LOW IN BETWEEN ILG AND PHL. BANDING ON THE NORTHERN SIDE OF THIS LOW IS PRODUCING AN AREA OF HEAVY RAIN (1-2 INCHES PER HOUR) THAT HAS REMAINED NEARLY JUST SOUTH OF PHILA OVER THE PAST 2-3 HOURS. THE RAP HAS THE 850 MB LOW SLOWLY MOVING EASTWARD INTO SOUTHERN NJ THRU ABOUT MIDNIGHT BEFORE IT OPENS UP AND MOVES TO OUR NORTHEAST OVERNIGHT. THE ASSOCIATED BAND OF HEAVY RAIN WILL FOLLOW A SIMILAR TRACK. THE REST OF THE FORECAST AREA SHOULD REMAIN MOSTLY DRY THOUGH THERE WILL BE SPOTTY SHOWERS. LOW CLOUDS WILL THE FLASH FLOOD WATCH HAS BEEN CANCELLED. MOST OF THE 630 PM UPDATE WAS FOCUSED ON POPS, WX AND QPF. THE LATEST RADAR TRENDS SHOW THE RAINFALL INTENSITY HAS REALLY DIMINISHED OVER THE PAST COUPLE OF HOURS ACROSS THE AREA AS PRECIP BECOMES INCREASINGLY STRATIFORM AND THE DEEPER CONVECTION HAS SHIFTED OFFSHORE. THE BACK EDGE OF THE STEADY RAIN HAS ALREADY MADE IT EASTWARD INTO THE DELAWARE VALLEY, SO EXPECT SHOWERS TO BECOME MORE SCATTERED THIS EVENING BEHIND THIS BACK EDGE. HOWEVER, SHOWERS MAY LINGER ACROSS THE POCONOS AND NORTHERN NEW JERSEY WHERE A WEAK DEFORMATION BAND IS FORECAST TO PIVOT THRU ON THE NORTHERN/NORTHWESTERN SIDE OF THE CLOSED H8 LOW. LOW CLOUDS WILL HANG ON THRU MUCH OF THE NIGHT, WHICH SHOULD KEEP TEMPS FROM DROPPING MUCH OVERNIGHT. SOME CLEARING IS EXPECTED IN OUR WESTERN ZONES BY EARLY MORNING. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... BY DAYBREAK ANY LINGERING PRECIP SHOULD BE MOSTLY CONFINED OFF SHORE, THOUGH SOME LOW CLOUDS COULD LINGER THROUGH THE MORNING HOURS, PRIMARILY FROM THE DELAWARE VALLEY AND FURTHER EAST. THE COLDER AIR MASS WILL BE IN PLACE TOMORROW, AND AS A RESULT, SHOULD SEE HIGHS NEAR OR SLIGHTLY BELOW NORMAL. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... THE EXTENDD STARTS OUT WET AND THEN ENDS UP DRY. HOWEVER, AFTER A PROLONGED PERIOD OF DRY WX, WE WILL HAVE SEVERAL SHOTS OF PRECIP THROUGH THE WEEKEND. UNFORTUNATELY, IT`S THE WEEKEND. THEN THERE WILL BE A RETURN TO MORE PLEASANT, SEPTEMBER-LIKE WX. WK HIGH PRES WILL BE OVER THE REGION AT THE START OF THE PD FRI NIGHT AND DRY WX WILL BE EXPECTED INTO ERLY SAT. THEN, LOW PRES WILL MOVE UP FROM THE SEN PORTION OF THE NATION AND BRING RAIN AS EARLY AT SAT AFTN. THERE ARE STILL SOME TIMING DIFFS WRT THE ONSET OF PRECIP, BUT THE 12Z CYCLE AS A WHOLE HAS SPED UP ONSET TIME. IS THIS THE START OF A TREND, OR ONE CYCLE REMAIN TO BE SEEN. SAT NIGHT LOOKS TO BE THE WETTEST PD. THEN ON SUN, YET A SECOND LOW LOOKS TO DEVELOP ALG THE STALLED FRONT. EXACTLY WHERE THE FRONT IS AND WHERE THE LOW FORMS WILL DETERMINE HOW WET SUN IS. ERLY SUN LOOKS TO BE WET, ESPECIALLY UP N. THEN, THERE CUD BE A SIGNIFICANT BREAK BEFORE MORE PRECIP IN THE AFTN. WHETHER CHANCES ARE BEST CLOSER TO THE CST, UP N, OR EVERYWHERE, STILL NEEDS TO BE RESOLVED IN THE MDLS. SO FOR NOW ILL JUST CARRY HIGH CHC POPS. AS THE LOW PULLS AWAY, ITS ASSOCD CDFNT WILL MOVE THRU AND THIS WILL BRING IN NW FLOW. BY LATER SUN, A LARGE AREA OF HIGH PRES WILL BE MOVG IN FROM THE SW. THIS WILL DRY THINGS OUT AND BRING A RETURN TO DRY WX FOR MUCH OF THE UPCOMING WEEK. TEMPS WILL BE MUCH CLOSER TO NRML WITH MUCH MORE PLEASANT HUMIDITY VALUES. WE WILL PROBABLY EVEN BE BELOW NRML ON SUN, WITH ABUNDANT CLOUDS AND THEN GOOD NW FLOW ON MON, BEFORE A RETURN TO NR OR SLIGHTLY ABV NRML FOR THE REST OF THE PD. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. A BAND OF MODERATE TO HEAVY SHOWERS WILL CONTINUE TO IMPACT PHL THRU MIDNIGHT BEFORE IT TAPERS OFF FROM WEST TO EAST OVERNIGHT. OTHERWISE, IFR CIGS ARE PRESENT AT THE I-95 TAF SITES AND MVFR ELSEWHERE. EXPECT CIGS TO LOWER TO IFR AT MIV/ACY, PROBABLY AROUND OR JUST AFTER MIDNIGHT. KEPT CIGS MVFR AT RDG/ABE WHERE SOUNDINGS SHOW SLIGHTLY DRIER AIR IN THE LOWEST 1 KFT. CLOUDS SHOULD SCATTER OUT AND CIGS SHOULD RISE FROM WEST TO EAST BETWEEN 08Z AND 14Z FRIDAY. WINDS WILL BACK FROM NORTHERLY OR NORTHEASTERLY NOW TO NORTHWESTERLY BY LATE TONIGHT. OUTLOOK... FRI NIGHT...VFR. HIGH CONFIDENCE. SAT...VFR TO START, BUT LOWERING CONDS AS LOW PRES APPROACHES FROM THE SW AND RAIN MOVES IN DURG THE AFTN. MVFR/IFR PSBL. STILL SOME TIMING ISSUES. MODERATE CONFIDENCE. SAT NIGHT...MVFR/IFR LIKELY IN PDS OF STEADY/HEAVY RAIN. SUN...ANOTHER LOW PRES MOVES THRU ALG STALLED FRONT. VFR EXPECTED, BUT MVFR/IFR PSBL, ESPECIALLY IN THE MRNG, DEPENDING ON THE TIMING OF THE LOW AND THE FRONT. LOW CONFIDENCE. SUN NIGHT-MON...HIGH PRES. VFR. HIGH CONFIDENCE. && .MARINE... SEAS SHOULD STAY BELOW SMALL CRAFT ADVISORY CRITERIA TONIGHT AND TOMORROW. WINDS MAY APPROACH 25 KT LATE TONIGHT FOR THE ATLANTIC WATERS ADJACENT TO NORTHERN NEW JERSEY, BUT AT THIS TIME, ANTICIPATE THAT THEY WILL STAY JUST BELOW CRITERIA. GUSTY WINDS MAY ALSO BE POSSIBLE IN THE VICINITY OF ANY THUNDERSTORMS THIS AFTERNOON AND EVENING. OUTLOOK... FRI NIGHT THROUGH SUN...SUB-ADVISORY CONDITIONS ARE EXPECTED TO CONTINUE ON THE AREA WATERS. SEAS WILL REMAIN AROUND 2 TO 4 FEET THROUGH THE WEEKEND, WITH WIND GENLY SSE ON SAT BECOMING SW ON SUN AT 10 TO 15 KT. SUN NIGHT INTO MON...HIGH PRESSURE WILL BUILD IN BEHIND A DEPARTING LOW. THE TIGHT PGRAD BETWEEN THESE SYSTEMS WILL ALLOW FOR WESTERLY WINDS TO BECOME GUSTY, AOA 25 KTS. SEAS WILL ALSO INCREASE BUT ARE EXPECTED TO REMAIN BELOW 5 FT ATTM. SCA MAY BE NEEDED BEGINNING SUN NIGHT AND CONTINUING INTO ERLY MON BEFORE THE PGRAD RELAXES. && .RIP CURRENTS... WHILE A LOW OR LOW ENHANCED RISK OF RIP CURRENTS IS EXPECTED THU- FRI, THE RISK MAY INCREASE TO MODERATE LATE SATURDAY OR SUNDAY WITH A DEVELOPING 4 FOOT SHORT PERIOD SOUTHERLY SWELL. WIND DIRECTION WILL BE THE DETERMINING FACTOR. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...NIERENBERG NEAR TERM...KLEIN SHORT TERM...JOHNSON LONG TERM...NIERENBERG AVIATION...JOHNSON/KLEIN/NIERENBERG MARINE...JOHNSON/KLEIN/NIERENBERG RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1247 AM EDT WED SEP 9 2015 .SYNOPSIS... HIGH PRESSURE IN THE ATLANTIC WILL CIRCULATE A MOIST SOUTH FLOW INTO THE FORECAST AREA THROUGH THURSDAY. A WEAK SURFACE TROUGH WILL ALSO BE NEAR THE AREA. THE PATTERN WILL SUPPORT A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS ESPECIALLY NEAR THE TIMES OF MAXIMUM HEATING. DRIER AIR WILL BEGIN TO FILTER INTO THE REGION BY THE BEGINNING OF NEXT WEEK BEHIND A COLD FRONT THAT WILL PUSH THROUGH OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THE SHOWER CHANCE SHOULD REMAIN LOW DURING THE REST OF TONIGHT BECAUSE OF WEAK INSTABILITY. THE HRRR AND RADAR TRENDS SUPPORT JUST ISOLATED COVERAGE. HIGH LOW-LEVEL MOISTURE AND NOCTURNAL COOLING SHOULD LEAD TO STRATUS AND FOG DURING THE EARLY MORNING HOURS. THE TEMPERATURE FORECAST IS ON TRACK. EXPECT LOWS IN THE LOWER 70S. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... MODELS REMAIN IN GOOD AGREEMENT THROUGH THIS TIME PERIOD. UPPER FLOW WILL BE OUT OF THE SOUTHWEST...WITH THE MAIN UPPER TROUGH STILL OFF TO THE WEST OF THE REGION. CENTER OF THE UPPER RIDGE WILL BE OVER SOUTHERN FLORIDA. WITH SOUTH TO SOUTHWESTERLY LOW- LEVEL FLOW EXPECTED TO OCCUR THROUGH THE PERIOD...MOISTURE IS EXPECTED TO CONTINUE TO INCREASE EACH DAY ACROSS THE REGION. AFTERNOON TEMPERATURES WILL CONTINUE TO BE IN THE LOWER 90S FOR MOST AREAS...WITH OVERNIGHT LOWS FALLING INTO THE LOWER 70S. WITH THE MOISTURE INCREASE EXPECT TO SEE SCATTERED SHOWERS AND THUNDERSTORMS ESPECIALLY DURING THE AFTERNOONS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS WITH PREVIOUS DAYS FORECAST RUNS...THE GFS/ECMWF BEGIN TO DIVERGE WITH THEIR SOLUTIONS THROUGH THE LONGER TERM. BOTH MODELS DIVE AN UPPER TROUGH SOUTHEASTWARD OUT OF THE UPPER PLAINS STATES FRIDAY NIGHT INTO SATURDAY...THEN CREATE A CUTOFF LOW ACROSS THE EASTERN US. IT IS THE DEVELOPMENT AND PLACEMENT OF THIS CUTOFF THAT THE MODELS DISAGREE WITH OVER THE WEEKEND. THE GFS IS FARTHER SOUTH AND WEAKER THAN THE ECMWF...WITH THE ECMWF LIFTING THE LOW QUICKER TOWARDS THE NORTHEAST SUNDAY INTO MONDAY. OBVIOUSLY THE PLACEMENT AND MOVEMENT OF THE UPPER LOW WILL EVENTUALLY HAVE AN AFFECT ON THE FINAL PLACEMENT AND MOVEMENT OF THE EXPECTED COLD FRONT THAT WILL MOVE THROUGH THE REGION THIS WEEKEND. BOTH MODELS HAVE A PREFRONTAL TROUGH ACROSS THE REGION THROUGH SATURDAY. WHATEVER THE FINAL TRACK IS FOR THE UPPER LOW...BOTH MODELS SHOW THE FRONT PUSHING TOWARDS THE COAST SUNDAY...WITH THE ECMWF BEING FASTER WITH THE TRACK. HAVE LEANED A LITTLE MORE TOWARDS A BLEND OF THE TWO MODELS FOR NOW. EXPECTING SHOWERS AND THUNDERSTORMS TO OCCUR EACH AFTERNOON THROUGH SUNDAY...WITH DRYING FINALLY BEGINNING TO PUSH IN SUNDAY NIGHT. THE REGION SHOULD BEGIN TO SEE SOME COOLER TEMPERATURES AND DRYING TO START OFF THE WORK WEEK BEHIND THE COLD FRONTAL PASSAGE. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... ISOLATED SHOWERS CONTINUE JUST OUTSIDE OF THE FORECAST AREA EARLY THIS MORNING BUT CURRENT RADAR TRENDS SHOW NO THREAT AT THE TERMINALS AT THIS TIME. HIGH RESOLUTION MODELS ALL INDICATING IFR/MVFR CONDITIONS DEVELOPING OVERNIGHT. THIS AGREES WITH PERSISTENCE...SO WILL INCLUDE MORNING STRATUS AND/OR FOG IN ALL TAF SITES DURING THE PRE-DAWN HOURS THIS MORNING. COULD SEE ISOLATED SHOWERS OVERNIGHT GIVEN WEAK ISENTROPIC LIFT. CONDITIONS EXPECTED TO IMPROVE TO VFR AROUND MIDDAY TODAY AS SOUTHWEST WINDS INCREASE TO AROUND 5 TO 10 KNOTS. SCATTERED CONVECTION WILL RECONVENE DURING THE AFTERNOON ONCE AGAIN BUT WILL NOT MENTION IN THE TAFS FOR NOW DUE TO LOW CONFIDENCE IN TIMING AND AREAL COVERAGE. .EXTENDED AVIATION OUTLOOK...LATE NIGHT/MORNING FOG/STRATUS POSSIBLE...WITH A CHANCE OF AFTERNOON SHOWERS AND POSSIBLE THUNDERSTORMS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1059 PM CDT THU SEP 10 2015 .UPDATE... ISSUED AT 820 PM CDT THU SEP 10 2015 Convection and effective outflow boundary has exited the forecast area early this evening with storms still ongoing over far southwest Illinois and out to our west in northeast Missouri into central Iowa. ILX local objective analysis indicating the better instability has been pushed out to our west and south thanks to the afternoon storms with the RAP soundings showing Most Unstable Capes of 500-800 J/kg with the highest values over far western IL later this evening and overnight. Next mid level shortwave over the Dakotas this evening and forecast to shift over our area Friday morning. Cluser of storms over Kansas forecast to push into western Mo this evening with the stronger activity expected to remain south and west of our area overnight. Have made some adjustments to the overnight precip with the higher POPs returning as the upper wave approaches our area late tonight. Will have an updated ZFP out by 845 pm. && .SHORT TERM...(TONIGHT) ISSUED AT 245 PM CDT THU SEP 10 2015 19z/2pm surface analysis shows a cold front extending from Lake Superior southwestward into eastern Iowa. A cluster of thunderstorms that developed in advance of the front this morning continues to track E/SE across Livingston County...while additional storms are beginning to develop along its trailing outflow boundary from Bloomington-Normal northwestward to near Burlington, Iowa. LAPS mesoanalysis shows a narrow axis of SBCAPEs from 1500 to 2000J/kg along/ahead of the outflow, which will likely result in a few vigorous updrafts and the potential for hail with some of the storms over the next few hours. Once the sun sets and daytime instability wanes, any risk for hail/gusty winds will diminish. Will highlight the I-74 corridor with the highest PoPs early this evening as the outflow boundary becomes active. After that, think additional scattered thunderstorms will develop along the actual cold front and track E/SE into the area from late evening into the overnight hours. Based on timing of front, have kept locations south of the I-70 corridor dry until after midnight. Elsewhere have carried high chance PoPs. .LONG TERM...(Friday THROUGH Thursday) ISSUED AT 245 PM CDT THU SEP 10 2015 Cold front is progged to pass through central Illinois tonight and will be pushing into Indiana by Friday morning. Despite FROPA...models continue to show lingering showers across much of the area east of the Illinois River through the morning hours. With boundary moving even further away, most of the rain will come to an end by afternoon. Have therefore ended PoPs across the western half of the CWA after 18z. Will need to keep an eye on a deep upper low digging southward late in the day...as NAM continues to suggest scattered showers developing in association with this feature across north-central Illinois by mid to late afternoon. As a result...have kept low chance PoPs in the forecast along/northeast of a Bloomington to Danville line through the entire day. Much cooler conditions will be the rule this weekend, as 1024mb surface high builds southward out of Canada. GFS shows 850mb temps dropping into the 3 to 5C range on Saturday, supporting high temperatures only in the middle to upper 60s. In addition, as upper low digs southward into the Ohio River Valley, a few light showers will be possible across east-central Illinois. Have included slight chance PoPs east of I-57 accordingly. Surface ridge axis will be overhead by 12z Sunday, resulting in the coolest night of the forecast period. Clear skies/light winds will allow dry airmass to cool into the middle 40s in most areas by early Sunday morning. After that, upper low will retreat into eastern Canada and heights will rise substantially across the Midwest early next week. The end result will be a steady warming trend, with highs returning to the middle 80s by Tuesday and Wednesday. GFS/ECMWF are both in fairly good agreement that the next cold front will begin to approach by Thursday. As a result, have included chance PoPs across the western CWA Wednesday night, then everywhere on Thursday. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Friday NIGHT) ISSUED AT 1100 PM CDT THU SEP 10 2015 Forecast a bit more complicated late tonight that what we saw late this afternoon as a period of clear skies across the northeast half of our forecast area has led to some patchy fog to the north of the TAF sites. The last few runs of the HRRR model has taken and run with the idea of low stratu and vsbys advecting south overnight with MVFR and IFR cigs and vsbys, but that is the only solution I have seen to be so aggressive with the lowering of the cigs and vsbys. Forecast soundings off the operational models not showing much if any low cigs across the area late tonight into Friday morning as an upper level wave interacts with the cold front passing across our area late this evening bringing thicker cloud cover back into the forecast area and a return to showers and isold tsra. The rain itself may be enough to temporarily lower cigs at times tomorrow morning before a drying trend works in during the afternoon. Look for light east to northeast winds to turn more northerly on Friday and increase to 12 to 17 kts by afternoon with a few gusts at or above 20 kts during the afternoon, before we see a diminishing trend during the evening. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Smith SHORT TERM...Geelhart LONG TERM...Barnes AVIATION...Smith
AREA FORECAST DISCUSSION
NWS LINCOLN IL
830 PM CDT THU SEP 10 2015 .UPDATE... ISSUED AT 820 PM CDT THU SEP 10 2015 Convection and effective outflow boundary has exited the forecast area early this evening with storms still ongoing over far southwest Illinois and out to our west in northeast Missouri into central Iowa. ILX local objective analysis indicating the better instability has been pushed out to our west and south thanks to the afternoon storms with the RAP soundings showing Most Unstable Capes of 500-800 J/kg with the highest values over far western IL later this evening and overnight. Next mid level shortwave over the Dakotas this evening and forecast to shift over our area Friday morning. Cluser of storms over Kansas forecast to push into western Mo this evening with the stronger activity expected to remain south and west of our area overnight. Have made some adjustments to the overnight precip with the higher POPs returning as the upper wave approaches our area late tonight. Will have an updated ZFP out by 845 pm. && .SHORT TERM...(TONIGHT) ISSUED AT 245 PM CDT THU SEP 10 2015 19z/2pm surface analysis shows a cold front extending from Lake Superior southwestward into eastern Iowa. A cluster of thunderstorms that developed in advance of the front this morning continues to track E/SE across Livingston County...while additional storms are beginning to develop along its trailing outflow boundary from Bloomington-Normal northwestward to near Burlington, Iowa. LAPS mesoanalysis shows a narrow axis of SBCAPEs from 1500 to 2000J/kg along/ahead of the outflow, which will likely result in a few vigorous updrafts and the potential for hail with some of the storms over the next few hours. Once the sun sets and daytime instability wanes, any risk for hail/gusty winds will diminish. Will highlight the I-74 corridor with the highest PoPs early this evening as the outflow boundary becomes active. After that, think additional scattered thunderstorms will develop along the actual cold front and track E/SE into the area from late evening into the overnight hours. Based on timing of front, have kept locations south of the I-70 corridor dry until after midnight. Elsewhere have carried high chance PoPs. .LONG TERM...(Friday THROUGH Thursday) ISSUED AT 245 PM CDT THU SEP 10 2015 Cold front is progged to pass through central Illinois tonight and will be pushing into Indiana by Friday morning. Despite FROPA...models continue to show lingering showers across much of the area east of the Illinois River through the morning hours. With boundary moving even further away, most of the rain will come to an end by afternoon. Have therefore ended PoPs across the western half of the CWA after 18z. Will need to keep an eye on a deep upper low digging southward late in the day...as NAM continues to suggest scattered showers developing in association with this feature across north-central Illinois by mid to late afternoon. As a result...have kept low chance PoPs in the forecast along/northeast of a Bloomington to Danville line through the entire day. Much cooler conditions will be the rule this weekend, as 1024mb surface high builds southward out of Canada. GFS shows 850mb temps dropping into the 3 to 5C range on Saturday, supporting high temperatures only in the middle to upper 60s. In addition, as upper low digs southward into the Ohio River Valley, a few light showers will be possible across east-central Illinois. Have included slight chance PoPs east of I-57 accordingly. Surface ridge axis will be overhead by 12z Sunday, resulting in the coolest night of the forecast period. Clear skies/light winds will allow dry airmass to cool into the middle 40s in most areas by early Sunday morning. After that, upper low will retreat into eastern Canada and heights will rise substantially across the Midwest early next week. The end result will be a steady warming trend, with highs returning to the middle 80s by Tuesday and Wednesday. GFS/ECMWF are both in fairly good agreement that the next cold front will begin to approach by Thursday. As a result, have included chance PoPs across the western CWA Wednesday night, then everywhere on Thursday. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Friday EVENING) ISSUED AT 620 PM CDT THU SEP 10 2015 VFR conditions are expected to prevail during this forecast period. A cold front is slated to push southeast across the area late tonight and during the morning hours on Friday. Scattered showers and storms will be possible along the boundary, especially across our southern TAF sites where we included a period of rain with VCTS later tonight. Once the front clears our area, we look for winds, which will be light easterly tonight to become north and increase to between 12 and 17 kts late Friday morning and through the afternoon hours with some gusts at or just above 20 kts at times. Will have to watch for some lower cigs which are forecast to remain north of our area later tomorrow afternoon as models have a tendency to underplay the southward push to the cold advection stratocumulus. For now, will continue with VFR cigs into the late afternoon hours. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Smith SHORT TERM...Geelhart LONG TERM...Barnes AVIATION...Smith
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
722 PM EDT THU SEP 10 2015 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW && .SYNOPSIS... ISSUED AT 350 PM EDT THU SEP 10 2015 CHANCES FOR RAIN WILL INCREASE LATE TONIGHT THROUGH FRIDAY AS A COLD FRONT MOVES THROUGH THE AREA. MUCH COOLER FALL-LIKE WEATHER WILL FOLLOW FOR THE WEEKEND...WITH A WARMING TREND BRINGING TEMPERATURES BACK TO NEAR NORMAL AS HIGH PRESSURE DOMINATES FOR THE FIRST HALF OF THE WEEK. && .NEAR TERM /TONIGHT/... ISSUED AT 350 PM EDT THU SEP 10 2015 WEAK HIGH PRESSURE CONTINUES OVER THE REGION THIS AFTERNOON. SCATTERED CONVECTION PERSISTING OVER NORTHERN ILLINOIS IN VICINITY OF AN UPPER LEVEL WAVE. HAVE SEEN SOME CU FORMATION THIS AFTERNOON BUT IN GENERAL...SEEING GOOD DEAL OF SUNSHINE WITH SEASONABLE TEMPS IN THE LOWER 80S. FOCUS OF THE NEAR TERM REMAINS ON THE APPROACHING COLD FRONT AND UPPER WAVE WITH A GROWING CHANCE FOR RAIN SHOWERS AS THE NIGHT PROGRESSES. INITIAL BATCH OF CONVECTION OVER NORTHERN ILLINOIS MOVING EAST-SOUTHEAST. EXTRAPOLATION WOULD BRING THESE STORMS INTO THE NORTHERN WABASH VALLEY BY 22-23Z. THIS ALIGNS WELL WITH HRRR AND WRF HI-RES GUIDANCE. WITH THE AIRMASS QUITE A BIT MORE STABLE OVER THE FORECAST AREA THOUGH...EXPECT CURRENT INTENSITY TO STORMS TO DIMINISH CONSIDERABLY AS THEY APPROACH NORTHWEST COUNTIES...LIKELY DISSIPATING THIS EVENING. AT THIS POINT...THIS WOULD ONLY WARRANT LOW CHANCE POPS OVER NORTHWEST COUNTIES WITH DRY CONDITIONS CONTINUING ELSEWHERE. ONCE THE CONVECTION DIMINISHES...EXPECT A RELATIVELY QUIET NIGHT WITH MOST RAIN HOLDING OFF UNTIL THE PREDAWN HOURS AS THE FRONTAL BOUNDARY NEARS THE REGION. WILL GRADUALLY INCREASE POPS LATE TONIGHT GENERALLY NORTHWEST OF A SULLIVAN-INDY METRO-MUNCIE LINE WITH DRY WEATHER PERSISTING OVER THE SOUTHEAST HALF OF THE FORECAST AREA. TEMPS...SUBTLE WARM ADVECTION AHEAD OF THE FRONT WILL KEEP TEMPS MILD OVERNIGHT. MOS GUIDANCE MATCHED WITH LOW LEVEL THERMALS WELL AND UTILIZED A BLEND. EXPECT LOWS RANGING FORM THE UPPER 50S TO LOWER 60S. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... ISSUED AT 350 PM EDT THU SEP 10 2015 FORECAST CHALLENGES FOCUS ON PRECIP CHANCES THROUGH SATURDAY...ALONG WITH TEMPS THROUGHOUT THE PERIOD. FIRST TRUE BLAST OF FALL WEATHER POISED TO VISIT THE OHIO VALLEY OVER THE WEEKEND AS A SHARP UPPER TROUGH POSITIONS ITSELF OVER THE REGION. PRIOR TO THIS...WIDESPREAD RAIN SHOWERS ARE EXPECTED TO ACCOMPANY THE COLD FRONT AS IT SWINGS ACROSS CENTRAL INDIANA ON FRIDAY. AXIS OF LOW LEVEL CONVERGENCE COMBINED WITH DIFFLUENCE ALOFT AND POCKETS OF ISENTROPIC LIFT ALL SUPPORT A GOOD THREAT FOR RAIN SHOWERS...ESPECIALLY FROM LATE MORNING THROUGH THE AFTERNOON. DESPITE WEAK INSTABILITY ON FRIDAY...FEEL ISOLATED THUNDER MENTION IS WARRANTED WITH MODEL SOUNDINGS EXHIBITING A FEW HOURS OF STEEPER LAPSE RATES DURING THE AFTERNOON. QUITE POSSIBLE THAT THE GREATER CONVECTIVE THREAT COMES WITH THE TRAILING UPPER WAVE OVER THE WESTERN GREAT LAKES WITH STORMS DEVELOPING ON THE EDGE OF THE APPROACHING COLD POOL ALOFT. MOST OF THIS ACTIVITY SHOULD STAY NORTHWEST OF THE FORECAST AREA PRIOR TO FRIDAY EVENING...BUT THINK THE ARRIVAL OF THIS FEATURE COULD PROLONG THE PRECIP THREAT OVER PARTS OF THE FORECAST AREA THROUGH MUCH OF FRIDAY EVENING EVEN AS WHAT LITTLE INSTABILITY PRESENT DIMINISHES. THE UPPER TROUGH WILL AMPLIFY OVER THE REGION SATURDAY AS TWO SEPARATE VORTS DIVE INTO THE BASE OF THE TROUGH. COMBINED WITH STRENGTHENING COLD ADVECTION AS THE COLD POOL EXPANDS SOUTH INTO INDIANA...SATURDAY WILL HAVE A VERY AUTUMN-LIKE FEEL TO IT WITH PLENTY OF CLOUDS AND BREEZY NORTHERLY WINDS. CANNOT RULE OUT A FEW INSTABILITY SHOWERS AS WELL WITH THE ENERGY ALOFT SWINGING THROUGH AND WILL MAINTAIN LOW CHANCE POPS. SKIES SHOULD GRADUALLY CLEAR SATURDAY NIGHT AS THE UPPER TROUGH SLOWLY SHIFTS EAST AND HIGH PRESSURE BUILDS IN FROM THE WEST. SUNDAY WILL SEE MUCH MORE IN THE WAY OF SUNSHINE AS THE HIGH EXPANDS EAST AND SURFACE WINDS BACK TO A MORE WESTERLY DIRECTION. TEMPS...GENERALLY LEANED CLOSER TO COOLER MAVMOS GUIDANCE FOR FRIDAY HIGHS WITH CLOUDS AND PRECIP IN ABUNDANCE. NEAR THE COOL END OF MOS FOR SATURDAY AS HIGHS WILL BE ONLY IN THE 60S...AND MAY STRUGGLE TO CLIMB OUT OF THE LOWER 60S IN SOME AREAS WHICH IS WELL SUPPORTED BY LOW LEVEL THERMALS. TEMPS WILL BEGIN TO RECOVER ON SUNDAY AS THE COLD POOL SHIFTS EAST...RANGING FROM THE MID 60S EAST TO NEAR 70 WEST. CHILLY NIGHTS ON THE HORIZON THROUGH THE PERIOD...HIGHLIGHTED BY WHAT WILL LIKELY BE THE COLDEST NIGHT IN NEARLY FOUR MONTHS FOR MANY. EXPECT LOWS IN THE 40S BOTH MORNINGS ON THE WEEKEND WITH SUNDAY MORNING BEING THE COLDEST AS SKIES CLEAR AND WINDS DIMINISH. UNDERCUT MOS SLIGHTLY SUNDAY MORNING AS NORMAL COOL SPOTS MAY FALL AS LOW AS THE LOWER 40S. LOCATION OF THE HIGH CENTER TO THE WEST HOWEVER MAY KEEP LOWER LEVELS FROM FULLY DECOUPLING AND KEEPING TEMPS FROM COMPLETELY BOTTOMING OUT. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... ISSUED AT 229 PM EDT THU SEP 10 2015 REGIONAL INITIALIZATION LOOKS GOOD. UPPER LEVEL RIDGING WILL MOVE INTO THE AREA SUNDAY NIGHT AND PERSIST THROUGH WEDNESDAY...KEEPING THE WEATHER DRY. THEN TROUGHING FROM A LOW PRESSURE SYSTEM OVER CANADA AND AN ASSOCIATED COLD FRONT WILL APPROACH FROM THE NORTHWEST. THIS WILL BRING SLIGHT CHANCES FOR RAIN SHOWERS AND THUNDERSTORMS BACK TO THE FORECAST WEDNESDAY NIGHT...WITH BETTER CHANCES DURING THE DAY ON THURSDAY. THE PERIOD WILL BEGIN WITH BELOW NORMAL TEMPERATURES IN THE UPPER 40S FOR LOWS AND LOW 70S FOR AFTERNOON HIGHS...BEFORE REBOUNDING TO SEASONAL NORMALS AS THE RIDGE MOVES INTO PLACE. AS THE RIDGING PERSISTS...TEMPERATURES WILL THEN INCREASE TO ABOVE SEASONAL NORMALS FOR MID WEEK WITH HIGHS IN THE LOW 80S AND LOWS IN THE MID TO UPPER 60S. && .AVIATION /DISCUSSION FOR 110000Z TAF ISSUANCE/... ISSUED AT 722 PM EDT THU SEP 10 2015 WOULD NOT RULE OUT A VERY LIGHT AND BRIEF EVENING SHOWER PRIOR TO SUNSET PER RADAR TRENDS. CLOUDS WILL BE INCREASING FROM NORTHWEST TO SOUTHEAST THROUGH THE EVENING AND OVERNIGHT. HOWEVER...CONDITIONS SHOULD CONTINUE VFR UNTIL AT LEAST AROUND 08Z AT LAF...10Z AT HUF...12Z AT IND AND AND 13Z AT BMG AS A FRONTAL SYSTEM MOVES THROUGH. AT THAT TIME...GOOD CONFIDENCE IN WIDESPREAD COVERAGE OF POST-FRONTAL SHOWERS AND MVFR CONDITIONS THROUGH AT LEAST MUCH OF THE DAY ON FRIDAY. SHOWERS SHOULD BE ENDING AND CONDITIONS IMPROVING TO VFR OR NEAR VFR AFTER 19Z AT LAF AND A FEW HOURS LATER ELSEWHERE FURTHER SOUTHEAST WINDS WILL BE VERY LIGHT TO CALM TONIGHT AND BECOME NORTHWEST BEHIND THE FRONT AND INCREASE TO NEAR 10 KNOTS AFTER 15Z FRIDAY. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...RYAN NEAR TERM...RYAN SHORT TERM...RYAN LONG TERM...MMB/CP AVIATION...MK
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1256 PM CDT WED SEP 9 2015 ...Updated aviation section... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT WED SEP 9 2015 The main forecast challenge for early this morning is areas of fog, and or stratus and how dense. Moist weak northeasterly upslope flow and with clear skies is allowing for good radiational cooling, and causing areas of ground fog to develop and some stratus. Will carry areas of fog in most areas this morning, but may need a dense fog advisory in places especially near and west of Dodge City where the NAM and the RAP model shows the highest boundary layer relative humidity. The HRRR model also shows patchy dense fog in the Garden City area. After the fog burns off by mid morning, expect clearing skies and highs in the mid 80s. A surface high pressure ridge will move east while a trough of low pressure develops in the lee of the Rockies. Light and variable winds this morning will become southeast to southerly at 10 mph with 10 to 20 mph far west. For tonight, expect mainly clear skies. A few thunderstorms could develop late across the I-70 corridor as a jet streak moves in. Will carry some small chances for rainfall, towards dawn. Overnight lows will be in the lower 60s with light southeast winds becoming south around 8 to 12 mph. .LONG TERM...(Thursday THROUGH Tuesday) ISSUED AT 339 AM CDT WED SEP 9 2015 For Thursday, an upper level shortwave trough in northwest flow aloft will move across western Kansas pushing a cold front to near Hays to Garden City and Elkhart by late afternoon. Ahead of the cold front, warmer and moist south winds of 15 to 25 mph, will push highs to around 90. Most models have thunderstorms developing by afternoon ahead of the cold front, with a possible MCS (Mesoscale Convective Complex) developing near and east of Dodge City by late afternoon and evening. The cold front will continue to push across western Kansas overnight with numerous thunderstorms developing. Some low stratus is also suggested towards dawn behind the cold front. Will carry around 50 percent chances in the afternoon and evening with lesser chances north of Garden City where dewpoints are much lower. Forecast instability is around 2000-3000 J/KG, but the NAM is much higher and with dewpoints in the upper 60s. With 30kt at mid levels and around 50 to 60kt aloft there could be some severe thunderstorms with large hail from quarter to half dollar size, and strong winds over 60 mph. For Friday into next Tuesday, a dry period is forecast. A large upper level trough will continue to dig into the Upper Midwest and Mississippi Valley with much cooler surface high pressure moving into the Plains. Highs on Friday and Saturday will be in the mid to upper 70s. As the upper trough moves away from the region Sunday into Tuesday, a warming trend will move back into the High Plains with highs in the low 80s on Sunday, then mid to upper 80s on Monday and Tuesday. Overnight lows will be in the 50s into Sunday morning, the gradually warm to 60 to 65 degrees on Monday and Tuesday morning. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Thursday AFTERNOON) ISSUED AT 1253 PM CDT WED SEP 9 2015 Low clouds will dissipate over the next couple of hours leading to VFR conditions for the remainder of the afternoon into the evening hours. Winds will generally be from the south around 8 knots as lee troughing redevelops across eastern Colorado. && .PRELIMINARY POINT TEMPS/POPS... DDC 85 62 89 60 / 0 10 40 40 GCK 85 61 90 59 / 0 0 30 30 EHA 87 63 91 60 / 10 10 20 20 LBL 86 62 92 61 / 0 10 30 40 HYS 87 61 89 60 / 0 20 30 30 P28 85 63 89 64 / 0 10 20 50 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Kruse LONG TERM...Kruse AVIATION...Hovorka_42
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
702 AM CDT WED SEP 9 2015 ...Updated for aviation discussion... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT WED SEP 9 2015 The main forecast challenge for early this morning is areas of fog, and or stratus and how dense. Moist weak northeasterly upslope flow and with clear skies is allowing for good radiational cooling, and causing areas of ground fog to develop and some stratus. Will carry areas of fog in most areas this morning, but may need a dense fog advisory in places especially near and west of Dodge City where the NAM and the RAP model shows the highest boundary layer relative humidity. The HRRR model also shows patchy dense fog in the Garden City area. After the fog burns off by mid morning, expect clearing skies and highs in the mid 80s. A surface high pressure ridge will move east while a trough of low pressure develops in the lee of the Rockies. Light and variable winds this morning will become southeast to southerly at 10 mph with 10 to 20 mph far west. For tonight, expect mainly clear skies. A few thunderstorms could develop late across the I-70 corridor as a jet streak moves in. Will carry some small chances for rainfall, towards dawn. Overnight lows will be in the lower 60s with light southeast winds becoming south around 8 to 12 mph. .LONG TERM...(Thursday THROUGH Tuesday) ISSUED AT 339 AM CDT WED SEP 9 2015 For Thursday, an upper level shortwave trough in northwest flow aloft will move across western Kansas pushing a cold front to near Hays to Garden City and Elkhart by late afternoon. Ahead of the cold front, warmer and moist south winds of 15 to 25 mph, will push highs to around 90. Most models have thunderstorms developing by afternoon ahead of the cold front, with a possible MCS (Mesoscale Convective Complex) developing near and east of Dodge City by late afternoon and evening. The cold front will continue to push across western Kansas overnight with numerous thunderstorms developing. Some low stratus is also suggested towards dawn behind the cold front. Will carry around 50 percent chances in the afternoon and evening with lesser chances north of Garden City where dewpoints are much lower. Forecast instability is around 2000-3000 J/KG, but the NAM is much higher and with dewpoints in the upper 60s. With 30kt at mid levels and around 50 to 60kt aloft there could be some severe thunderstorms with large hail from quarter to half dollar size, and strong winds over 60 mph. For Friday into next Tuesday, a dry period is forecast. A large upper level trough will continue to dig into the Upper Midwest and Mississippi Valley with much cooler surface high pressure moving into the Plains. Highs on Friday and Saturday will be in the mid to upper 70s. As the upper trough moves away from the region Sunday into Tuesday, a warming trend will move back into the High Plains with highs in the low 80s on Sunday, then mid to upper 80s on Monday and Tuesday. Overnight lows will be in the 50s into Sunday morning, the gradually warm to 60 to 65 degrees on Monday and Tuesday morning. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Thursday MORNING) ISSUED AT 659 AM CDT WED SEP 9 2015 Weak surface high pressure will move off to the east and be replaced by a surface trough in the lee of the Rockies. This will result in light winds becoming south at 5 to 10 mph this afternoon. Dense fog this morning at KDDC/KGCK will rapidly clear by 15z with daytime heating, leaving VFR conditions for the remainder of the period. && .PRELIMINARY POINT TEMPS/POPS... DDC 85 62 89 60 / 0 10 40 40 GCK 85 61 90 59 / 0 0 30 30 EHA 87 63 91 60 / 10 10 20 20 LBL 86 62 92 61 / 0 10 30 40 HYS 87 61 89 60 / 0 20 30 30 P28 85 63 89 64 / 0 10 20 50 && .DDC Watches/Warnings/Advisories... Dense Fog Advisory until 9 AM CDT /8 AM MDT/ this morning for KSZ043>045-061>066-074>081-084>090. && $$ SHORT TERM...Kruse LONG TERM...Kruse AVIATION...Finch
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
342 AM CDT WED SEP 9 2015 ...Updated for Long Term... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT WED SEP 9 2015 The main forecast challenge for early this morning is areas of fog, and or stratus and how dense. Moist weak northeasterly upslope flow and with clear skies is allowing for good radiational cooling, and causing areas of ground fog to develop and some stratus. Will carry areas of fog in most areas this morning, but may need a dense fog advisory in places especially near and west of Dodge City where the NAM and the RAP model shows the highest boundary layer relative humidity. The HRRR model also shows patchy dense fog in the Garden City area. After the fog burns off by mid morning, expect clearing skies and highs in the mid 80s. A surface high pressure ridge will move east while a trough of low pressure develops in the lee of the Rockies. Light and variable winds this morning will become southeast to southerly at 10 mph with 10 to 20 mph far west. For tonight, expect mainly clear skies. A few thunderstorms could develop late across the I-70 corridor as a jet streak moves in. Will carry some small chances for rainfall, towards dawn. Overnight lows will be in the lower 60s with light southeast winds becoming south around 8 to 12 mph. .LONG TERM...(Thursday THROUGH Tuesday) ISSUED AT 339 AM CDT WED SEP 9 2015 For Thursday, an upper level shortwave trough in northwest flow aloft will move across western Kansas pushing a cold front to near Hays to Garden City and Elkhart by late afternoon. Ahead of the cold front, warmer and moist south winds of 15 to 25 mph, will push highs to around 90. Most models have thunderstorms developing by afternoon ahead of the cold front, with a possible MCS (Mesoscale Convective Complex) developing near and east of Dodge City by late afternoon and evening. The cold front will continue to push across western Kansas overnight with numerous thunderstorms developing. Some low stratus is also suggested towards dawn behind the cold front. Will carry around 50 percent chances in the afternoon and evening with lesser chances north of Garden City where dewpoints are much lower. Forecast instability is around 2000-3000 J/KG, but the NAM is much higher and with dewpoints in the upper 60s. With 30kt at mid levels and around 50 to 60kt aloft there could be some severe thunderstorms with large hail from quarter to half dollar size, and strong winds over 60 mph. For Friday into next Tuesday, a dry period is forecast. A large upper level trough will continue to dig into the Upper Midwest and Mississippi Valley with much cooler surface high pressure moving into the Plains. Highs on Friday and Saturday will be in the mid to upper 70s. As the upper trough moves away from the region Sunday into Tuesday, a warming trend will move back into the High Plains with highs in the low 80s on Sunday, then mid to upper 80s on Monday and Tuesday. Overnight lows will be in the 50s into Sunday morning, the gradually warm to 60 to 65 degrees on Monday and Tuesday morning. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Wednesday NIGHT) ISSUED AT 1201 AM CDT WED SEP 9 2015 Areas of LIFR conditions with ground fog and some low stratus will prevail through 14-15Z this morning as winds are light northeasterly and moist upslope along with clear skies and excellent radiational cooling. As a dome of surface high pressure moves east, winds shift to light southeasterly with clearing skies after 15Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 85 62 89 60 / 0 10 50 50 GCK 85 61 90 59 / 0 0 30 20 EHA 87 63 91 60 / 10 10 30 30 LBL 86 62 92 61 / 0 10 30 40 HYS 87 61 89 60 / 0 20 30 40 P28 85 63 89 64 / 0 10 20 50 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Kruse LONG TERM...Kruse AVIATION...Kruse
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
316 AM CDT WED SEP 9 2015 ...Updated for Short Term... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 313 AM CDT WED SEP 9 2015 The main forecast challenge for early this morning is areas of fog, and or stratus and how dense. Moist weak northeasterly upslope flow and with clear skies is allowing for good radiational cooling, and causing areas of ground fog to develop and some stratus. Will carry areas of fog in most areas this morning, but may need a dense fog advisory in places especially near and west of Dodge City where the NAM and the RAP model shows the highest boundary layer relative humidity. The HRRR model also shows patchy dense fog in the Garden City area. After the fog burns off by mid morning, expect clearing skies and highs in the mid 80s. A surface high pressure ridge will move east while a trough of low pressure develops in the lee of the Rockies. Light and variable winds this morning will become southeast to southerly at 10 mph with 10 to 20 mph far west. For tonight, expect mainly clear skies. A few thunderstorms could develop late across the I-70 corridor as a jet streak moves in. Will carry some small chances for rainfall, towards dawn. Overnight lows will be in the lower 60s with light southeast winds becoming south around 8 to 12 mph. .LONG TERM...(Wednesday NIGHT THROUGH Tuesday) ISSUED AT 318 PM CDT TUE SEP 8 2015 Some elevated showers and thunderstorms will be possible around central Kansas late Wednesday night as an area of mid level warm advection develops. These should diminish Thursday morning as low level mixing increases. Northwesterly flow aloft will continue on Thursday. Another shortwave trough will drop out of Alberta into the Midwest on Thursday. This will push another cold front south through western Kansas late Thursday afternoon and Thursday night. Ahead of this front, the boundary layer warms up nicely as low level winds take on a slightly downslope component. Have bumped up Thursdays high temperatures 2-4 degrees in most areas. Widely scattered thunderstorms are expected to develop along and ahead of the cold front across western Kansas by mid to late afternoon. The area of storms will gradually shift to the south and east Thursday night and could linger into Friday before ending. Highs on Friday will be quite a bit cooler behind the front. Model guidance suggests highs in the 70s and this may be a little warm depending on how long any post frontal cloud cover lingers over the area. The weekend into early next week should see dry conditions and moderating temperatures as upper level high pressure redevelops and moves east across the central and southern Plains. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Wednesday NIGHT) ISSUED AT 1201 AM CDT WED SEP 9 2015 Areas of LIFR conditions with ground fog and some low stratus will prevail through 14-15Z this morning as winds are light northeasterly and moist upslope along with clear skies and excellent radiational cooling. As a dome of surface high pressure moves east, winds shift to light southeasterly with clearing skies after 15Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 85 62 89 60 / 0 10 50 50 GCK 85 61 90 59 / 0 0 30 20 EHA 87 63 91 60 / 10 10 30 30 LBL 86 62 92 61 / 0 10 30 40 HYS 87 61 89 60 / 0 20 30 40 P28 85 63 89 64 / 0 10 20 50 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Kruse LONG TERM...Gerard AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1139 PM MDT TUE SEP 8 2015 .UPDATE... ISSUED AT 539 PM MDT TUE SEP 8 2015 A FEW THUNDERSTORMS HAVE POPPED UP IN N-S ORIENTED INSTABILITY AXIS ACROSS EASTERN HALF OF CWA. EXPECT CINH TO STEADILY INCREASE OVER THE NEXT 2 HOURS WHICH WILL ULTIMATELY LIMIT THE COVERAGE AND DURATION THROUGH THE EARLY EVENING. SEEMS TO BE A PRETTY SHARP MOISTURE GRADIENT ACROSS THE AREA ATTM WITH DEWPOINTS AROUND 20 DEGREES COOLER IN THE WEST. WITH LIGHT WINDS AND CLEAR SKIES MAY HAVE TO RETHINK LOW TEMPS...AND HAVE ALSO MODIFIED FOG FORECAST A BIT TO REFLECT THIS ORIENTATION. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 222 PM MDT TUE SEP 8 2015 WV IMAGERY AND RAP H5 ANALYSIS SHOWS NW FLOW ACROSS CENTRAL ROCKIES AND OVER OUR CWA ON WESTERN EXTENT OF LARGE SCALE TROUGH. AXIS OF SUBSIDENCE IS CURRENTLY IN PLACE AS A SHORTWAVE TROUGH IS MOVING ACROSS CENTRAL KANSAS. AT THE SURFACE HIGH PRESSURE IS BUILDING INTO OUR CWA FROM THE NORTHERN PLAINS WITH A COLD FRONT THAT MOVED THROUGH OUR CWA EARLY THIS MORNING EXTENDING FROM NORTHEAST KANSAS THROUGH SOUTH CENTRAL KANSAS. TONIGHT...DRY CONDITIONS SHOULD PERSIST THROUGH THE OVERNIGHT PERIOD WITH SUBSIDENCE PERSISTING THROUGH MOST OF THE NIGHT...AND DEEP DRY AIR MASS IN PLACE. EARLY IN THE EVENING STEEP LAPSE RATES LEE TROUGH REBUILDS ALONG KS/CO BORDER OVERNIGHT WITH SOUTHERLY FLOW BRINING HIGH BL MOISTURE IN PLACE. TREND IN GUIDANCE HAS BEEN TO TO SHOW BETTER MIXING AND BL RH STAYING UP LIMITING FOG POTENTIAL. NAM AND RAP DO STILL SHOW SOME REDUCED VISIBILITIES AND I FELT COMFORTABLE KEEPING MENTION IN FORECAST FOR NOW. WEDNESDAY...A QUICK MOVING/WEAK SHORTWAVE TROUGH WILL ROTATE THROUGH NW FLOW JUST NORTH OF OUR CWA. DRY LAYER IN PLACE LOWERS OVERALL CONFIDENCE IN COVERAGE...HOWEVER GUIDANCE IS SHOWING INITIATION EITHER UPSTREAM OR ALONG SURFACE TROUGH AND TRACKING EAST ACROSS THE NORTHERN HALF OF OUR CWA. IF A CELL WERE TO DEVELOP ML CAPE VALUES AROUND 2000 J/KG AND EFFECTIVE SHEAR VALUES AROUND 35KT COULD SUPPORT A LIMITED SEVERE THREAT. IM JUST NOT SURE IF ANYTHING WILL EVEN DEVELOP CONSIDERING THE DRY AIR MASS IN PLACE. I KEPT SLIGHT CHANCE POPS IN THE AFTERNOON...COVERING POTENTIAL. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 255 PM MDT TUE SEP 8 2015 SEVERAL SHORT WAVE TROUGHS MOVE ACROSS THE CENTRAL HIGH PLAINS REGION WEDNESDAY NIGHT...THURSDAY NIGHT...AND FRIDAY EVENING. THE UPPER PATTERN BECOMES MORE AMPLIFIED AS THE SHORT WAVE TROUGHS DIVE INTO THE BASE OF THE MAIN UPPER TROUGH POSITIONED OVER THE MISSISSIPPI VALLEY REGION AS THE UPPER RIDGE AMPLIFIES OVER THE WESTERN UNITED STATES THURSDAY THROUGH FRIDAY NIGHT AND TRANSITIONS EASTWARD OVER THE ROCKIES AND HIGH PLAINS SATURDAY NIGHT. WITH A SURFACE TROUGH/FRONTAL BOUNDARY REMAINING IN THE VICINITY OF THE FORECAST AREA THESE SHORT WAVE TROUGHS TRANSITIONING THE REGION WILL HELP ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP EACH DAY FROM LATE WEDNESDAY THROUGH EARLY FRIDAY. BY LATE FRIDAY THE FRONTAL BOUNDARY HAS PUSHED SOUTH OF THE REGION AND SURFACE HIGH PRESSURE MOVES INTO THE AREA. TEMPERATURES WILL WARM THROUGH THURSDAY AHEAD OF THE FRONT WITH HIGH TEMPERATURES ONLY EXPECTED TO REACH IN TO THE 70S ON FRIDAY. TEMPERATURES WILL REBOUND QUICKLY THROUGH THE WEEKEND AND INTO NEXT WEEK AS SOUTHERLY NEAR SURFACE FLOW RETURNS AND THE REGION REMAINS UNDER WEAK RIDGING THROUGH THE WEEKEND AS THE UPPER PATTERN UNDERGOES A TRANSITION TO A RIDGE OVER THE EASTERN HALF OF THE UNITED STATES WHILE THE NEXT SIGNIFICANT LONG WAVE TROUGH DEEPENS OVER THE WESTERN UNITES STATES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1136 PM MDT TUE SEP 8 2015 POTENTIAL PERIOD OF IFR VISIBILITIES OVERNIGHT LOOKS ON TRACK AS LIGHT EASTERLY WINDS SLOWLY ADVECTING INCREASING TDS INTO THE AREA...WITH SFC TEMPS BELOW DOWNSTREAM DEWPOINTS IN SEVERAL AREAS. SATELLITE FOG PRODUCT STARTING TO PICK UP ON SOME LOW STRATUS AS WELL WITH HLC SEEING CLOUD HEIGHTS AROUND 2000 FEET. THIS LOOKS RATHER SPOTTY FOR NOW AND PLAN TO KEEP MAIN FOCUS OF TAFS INCREASING THREAT FOR FOG. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JRM SHORT TERM...DR LONG TERM...LOCKHART AVIATION...JRM
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1003 PM EDT THU SEP 10 2015 ...FORECAST UPDATE... ISSUED AT 955 PM EDT THU SEP 10 2015 THE DENSE FOG ADVISORY FOR PORTIONS OF EAST CENTRAL KY STILL LOOKS GOOD ACCORDING TO THE LATEST OBS, NAM, AND HRRR GUIDANCE. A GOOD BUBBLE OF LOW LEVEL MOISTURE COMBINED WITH SUBSIDENCE FROM A SFC HIGH OVER THAT REGION CONTINUE TO LOOK FAVORABLE FOR DENSE FOG FORMATION. IN FACT SOME LIGHT FOG HAS ALREADY STARTED TO FORM NEAR LONDON, KY. LIGHT PATCHY FOG IS EXPECTED ELSEWHERE WITH LOW TEMPS RANGING FROM THE UPPER 50S TO LOWER 60S. .SHORT TERM (NOW THROUGH FRIDAY NIGHT)... ISSUED AT 432 PM EDT THU SEP 10 2015 POPCORN SHOWERS OVER THE FAR SOUTHEAST WILL FALL APART AS THE SUN LOWERS IN THE SKY THIS AFTERNOON, FOLLOWED BY DISSIPATION OF THE CU FIELD AS THE SUN SETS. THIS WILL LEAD TO CLEAR SKIES AND NEARLY CALM WINDS TONIGHT, SUGGESTING THE POSSIBILITY OF FOG. SOME DRY LOW LEVEL AIR LOOKS TO SNEAK IN FROM THE NORTH, BUT SOUTHEASTERN AREAS OF THE CWA WILL NOT BENEFIT FROM THAT AIR AND ALSO SAW QUITE A BIT OF RAIN EARLIER TODAY TO ADD TO GROUND MOISTURE. AFTER CONFERRING WITH JKL, HAVE DECIDED TO GO AHEAD AND PUT OUT A DENSE FOG ADVISORY THIS AFTERNOON FOR THE FAR EAST AND SOUTHEAST PARTS OF THE CWA...GENERALLY FROM THE LAKE CUMBERLAND REGION TO SOUTH/EAST OF LEXINGTON. FOG WILL BE POSSIBLE ELSEWHERE AS WELL, BUT SHOULD BE MOSTLY CONFINED TO SPOTS THAT FOG IN EASILY AND SHOULDN`T BE QUITE AS WIDESPREAD AS IN THE ADVISORY COUNTIES. TOMORROW AN UNSEASONABLE UPPER TROF WILL COME IN FROM THE NORTHWEST AND SPARK SHOWERS AND THUNDERSTORMS, ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS. WE MAY GET SOME GUSTY SHOWERS AND PEA SIZED HAIL IN THE STRONGER SHOWERS...ESPECIALLY IN THE SOUTHEAST WHERE LAPSE RATES WILL BE A LITTLE STEEPER. WE`RE ALREADY SEEING THIS TO OUR WEST WITH ACTIVITY IN MISSOURI AND ILLINOIS TODAY. HIGH TEMPERATURES WILL BE A FEW DEGREES EITHER SIDE OF 80. RAIN CHANCES WILL DECREASE AFTER MIDNIGHT TOMORROW NIGHT AS TEMPERATURES FALL INTO THE 50S. .LONG TERM (SATURDAY THROUGH THURSDAY)... ISSUED AT 245 PM EDT THU SEP 10 2015 THE MAIN FORECAST CONCERN IN THE LONG TERM IS THE UNSEASONABLY COOL CONDITIONS THIS WEEKEND. A VERY ANOMALOUSLY DEEP SHORTWAVE TROUGH WILL DIVE ACROSS THE EASTERN U.S. SATURDAY INTO SUNDAY. ANOMALIES WITH THIS FEATURE ARE ROUGHLY 4 STANDARD DEVIATIONS BELOW NORMAL FOR HEIGHTS AND TEMPS. WITHIN THE DEEP CYCLONIC FLOW AND CRASHING TEMPERATURES ALOFT... THERE COULD BE SOME INSTABILITY SHOWERS OR PERHAPS A RUMBLE OF THUNDER DURING THE DAY SATURDAY. THE MAIN NEGATIVE FACTOR TO MORE WIDESPREAD SHOWERS IS LIMITED AND SHALLOW MOISTURE...AS PRECIPITABLE WATER VALUES ARE ONLY AROUND 0.75 INCH DURING THE DAY. MODEL SOUNDINGS FROM THE NAM AND GFS DO SHOW ABOUT 100 MB OF HIGHER RH BETWEEN 700 AND 800 MB. THINKING THAT WE WILL SEE A GOOD AMOUNT OF STRATO CU CLOUDS FORM WITH THE POTENTIAL FOR DIURNAL SCATTERED SHOWERS AT TIMES. WILL CONTINUE TO ADVERTISE 20-30 PERCENT POPS DURING THE AFTERNOON. THE MORE NOTICEABLE IMPACT WILL BE TEMPERATURES WITH HIGHS STRUGGLING TO REACH 70 IN MOST PLACES ALONG WITH NORTH/NORTHWEST BREEZES. THESE HIGHS WILL BE ABOUT 15 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR ON SATURDAY AND 10 TO 15 DEGREES BELOW NORMAL ON SUNDAY...AND A SOLID 20 TO 25 DEGREES COLDER THAN JUST EARLIER THIS WEEK. RECORD LOWS AND COLD MAXIMUMS SATURDAY AND SUNDAY DO NOT APPEAR TO BE IN JEOPARDY AT ANY OF THE OFFICIAL SITES. SURFACE HIGH PRESSURE BUILDS INTO THE REGION SATURDAY NIGHT INTO SUNDAY MORNING. LIGHT WINDS AND CLEARING SKIES...ESPECIALLY WEST OF I-65...SHOULD LEAD TO LOWS REACHING THE MID 40S TO NEAR 50 FOR SOUTHERN INDIANA AND CENTRAL KENTUCKY. ON SUNDAY...THE UPPER TROUGH AND SURFACE HIGH ADVANCE EASTWARD THOUGH WE WILL STILL HAVE COOLER TEMPERATURES ALOFT. HIGHS AGAIN IN THE UPPER 60S/NEAR 70. FOR NEXT WEEK...HEIGHTS AND TEMPERATURES ALOFT BUILD AS RELATIVELY WEAK WEST TO SOUTHWEST FLOW DEVELOPS. LOW-LEVEL WINDS WILL BECOME SOUTHEAST TO SOUTH IN RESPONSE...RESULTING IN A GRADUAL MODERATION IN TEMPERATURES. NO MAJOR STORM SYSTEMS ARE ON THE HORIZON THROUGH AT LEAST MID NEXT WEEK...BUT EVENTUALLY RETURN SOUTHERLY LOW-LEVEL FLOW AND A WEAK DISTURBANCE OR TWO ALOFT COULD BRING WIDELY SCATTERED CONVECTION TO PARTS OF THE AREA LATE NEXT WEEK. && .AVIATION (00Z TAF UPDATE)... ISSUED AT 725 PM EDT THU SEP 10 2015 CLOUD COVER HAS DECREASED THIS EVENING AS WE ENTER A BRIEF LULL IN BETWEEN WEATHER SYSTEMS. WITH MOIST LOW LEVELS AND A DECENT INVERSION IN BETWEEN SYSTEMS, LIGHT FOG FORMATION WILL CERTAINLY BE POSSIBLE LATE TONIGHT INTO THE MORNING HOURS. A FEW FLIES IN THE OINTMENT FOR FOG FORMATION/DENSITY WILL BE CLOUD COVER EITHER COMING IN FROM LEFT OVER STORMS TO OUR WEST OVERNIGHT OR SOME MODELS INDICATE A LOWER DECK AROUND 3-4 KFT AGL MAY FORM DURING THE PRE- DAWN HOURS. ALSO, LOW LEVEL WIND FIELDS ON THE SOUNDINGS ARE A LITTLE MIXY WHICH MAY INHIBIT FOG FORMATION/DENSITY AS WELL. STILL AN MVFR GROUP AT ALL THREE TAF SITES AND IFR TEMPOS AT BWG/LEX SEEM REASONABLE FROM 9Z-14Z. FOG SHOULD DIMINISH AT ALL LOCATIONS BY MID MORNING. THE NEXT TAF CONCERN WILL BE SHOWERS/STORMS AHEAD OF AN APPROACHING COLD FRONT FOR TOMORROW AFTERNOON. WENT AHEAD WITH VCTS AT ALL SITES ALTHOUGH SOME RESTRICTIONS IN STORMS WILL LIKELY NEED ADDED IN COMING TAF ISSUANCES. THE BEST TIME FOR STORMS WILL BE BETWEEN 19Z- 6Z WITH A FROPA OCCURRING BETWEEN 3-6Z SHIFTING WINDS FROM W TO NNW. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...DENSE FOG ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 9 AM EDT /8 AM CDT/ FRIDAY FOR KYZ056-057-066-067-077-078-081-082. IN...NONE. && $$ UPDATE.........AMS SHORT TERM.....13 LONG TERM......TWF AVIATION.......AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
310 PM EDT WED SEP 9 2015 .SHORT TERM (NOW THROUGH THURSDAY NIGHT)... ISSUED AT 245 PM EDT WED SEP 9 2015 AS OF MID AFTERNOON...WATER VAPOR IMAGERY AND 500 MB HEIGHTS SHOWED A SHORTWAVE TROUGH EXTENDING FROM THE GREAT LAKES DOWN ALONG THE MISSISSIPPI RIVER...JUST WEST OF CENTRAL KENTUCKY. AT THE SURFACE...THE ENVIORNMENT IS CHARACTERIZED BY WARM AND MOIST AIR WITH DEWPOINTS IN THE LOW 70S. A COLD FRONT LIED ALONG THE OHIO RIVER...SLOWLY MOVING EAST THROUGH THE AREA. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS MAINLY IN THE WARM SECTOR WILL CONTINUE THROUGH THE LATE AFTERNOON HOURS. THESE STORMS WILL BE CAPABLE OF PROUDCING BRIEF BUT VERY HEAVY RAINFALL GIVEN THE HIGH PWATS IN THE AREA. SOME GUSTY WINDS ARE POSSIBLE AS WELL. HI-RES MODELS SUCH AS THE HRRR AND 12Z SPC WRF ARE IN GOOD AGREEMENT SHOWING THE HIGHEST CHANCES NOW THROUGH EARLY EVENING...THEN A DECREASE IN COVERAGE AS THE UPPER SHORTWAVE TROUGH KICKS THE FRONT EAST THROUGH THE AREA. A SECONDARY LOW PRESSURE AND TROUGH NEAR MEMPHIS WILL TRACK THROUGH CENTRAL TN TO SOUTHEAST KY OVERNIGHT...KEEPING SOME SHOWERS AND STORMS IN THE FORECAST MAINLY OVERNIGHT FOR THE SOUTHERN FORECAST AREA. AREAS NORTH OF THE KY PARKWAYS INTO SOUTHERN INDIANA WILL PROBABLY SEE THE END OF THE RAIN FROM THIS SYSTEM THIS EVENING OR EARLY OVERNIGHT. LOW CLOUDS AND/OR FOG IS A CONCERN OVERNIGHT INTO THE THURSDAY MORNING COMMUTE AS THE BOUNDARY LAYER WILL REMAIN VERY MOIST WITH LIGHT WINDS. SREF PROBABIALITIES FOR LOW CLOUDS /500 FT OR LESS/ AND FOG ARE BETWEEN 40 AND 60 PERCENT. WILL HAVE TO WATCH FOR LOCALLY DENSE POCKETS OF FOG...ESPECIALLY IF THERE IS ANY CLEARING OR BREAKS IN THE CLOUDS TOWARD SUNRISE. IMPROVING CONDITIONS CAN BE EXPECTED DURING THE DAY THURSDAY. SOME LINGERING SHOWERS AND MAYBE A THUNDERSTORM WILL BE POSSIBLE ALONG AND SOUTHEAST OF A LEXINGTON TO BOWLNG GREEN LINE DURING THE MORNING BUT THIS SHOULD QUICKLY MOVE EAST BY NOON. NORTHWEST WINDS WILL PICK UP...HELPING TO SCATTER OUT OR LIFT SOME OF THE CLOUDS IN THE AREA. LOOK FOR HIGHS RIGHT AROUND NORMAL IN THE LOW 80S. .LONG TERM (FRIDAY THROUGH WEDNESDAY)... ISSUED AT 305 PM EDT TUE SEP 8 2015 THE LONG TERM PERIOD WILL START OUT WITH A COLD FRONT PASSAGE ON FRIDAY BRINGING SHOWERS/STORMS TO THE AREA FRI/FRI NIGHT. ALTHOUGH THE OVERALL FORCING NEAR THE FRONT AND WIND SHEAR LOOK RELATIVELY WEAK, THERE MAY BE ENOUGH SFC INSTABILITY TO PRODUCE A FEW STRONG CELLS DURING THE AFTERNOON HOURS FRIDAY. OVERALL THOUGH, DON`T SEE A BIG THREAT FOR ORGANIZED STRONG TO SEVERE CONVECTION FOR FRIDAY. THE BIGGER STORY WITH THIS FRONT WILL BE THE STRONG UPPER LOW AND MUCH COOLER AIRMASS FOLLOWING IT. WITH THESE FEATURES IN PLACE FOR THE WEEKEND, LOOK FOR TEMPS TO BE 6 TO 12 DEGREES BELOW NORMAL. SATURDAY WE`LL HAVE PLENTY OF LOW CLOUDS AND LINGERING SHOWERS LIMITING HIGHS TO THE MID TO UPPER 60S. SOME MODEL DATA SUGGESTS PERHAPS WE COULD SEE AN ISLD RUMBLE OF THUNDER WITH THIN, SHALLOW INSTABILITY PRESENT IN THE SOUNDINGS. SHOWER ACTIVITY SHOULD CONTINUE INTO SAT NIGHT BEFORE GRADUALLY ENDING FROM WEST TO EAST SUN MORNING. HIGHS ON SUNDAY WILL BE SIMILAR TO SAT IN THE MID TO UPPER 60S. LOW TEMPERATURES THIS WEEKEND WILL RANGE FROM THE MID 40S TO LOWER 50S WITH THE COOLEST NIGHT BEING SUN NIGHT INTO MONDAY MORNING WHEN SKIES WILL BECOME CLEAR WITH THE HIGH PRESSURE CENTER OVER THE REGION. WE`LL REMAIN DRY MON-WED WITH RETURN FLOW BRINGING WARMER TEMPS BACK INTO THE REGION. HIGHS ON MONDAY WILL WARM BACK INTO THE LOWER 70S WITH UPPER 70S/LOWER 80S EXPECTED BY TUES/WED UNDER MOSTLY SUNNY SKIES. && .AVIATION (18Z TAF UPDATE)... ISSUED AT 1258 PM EDT WED SEP 9 2015 MAINLY SHOWERS WILL AFFECT THE TERMINALS THROUGH THE OVERNIGHT PERIOD. FOR THIS AFTERNOON...EXPECT COVERAGE TO BE MORE SCATTERED IN NATURE WITH BRIEF DROPS TO MVFR POSSIBLE. SO FAR ACTIVITY HAS HAD VERY LITTLE IN-CLOUD OR CLOUD TO GROUND LIGHTNING AND WITH LESS COVERAGE...OPTED TO REMOVE VCTS FOR THIS AFTERNOON. LARGER BAND OF RAIN SHOWERS WILL THEN SPREAD OVER SDF/LEX...BETWEEN 21-03Z WEST TO EAST. FOG/STRATUS BECOMES THE NEXT CONCERN AT ALL SITES FOR THE OVERNIGHT. GUIDANCE IS HITTING LOW CLOUDS PRETTY HARD WITH IFR CONDITIONS BASED ON A WELL SATURATED BOUNDARY LAYER. THE WIND FIELD WILL ALSO BE LIGHT AND MOISTURE DOES LINGER WITH THE FRONT NEARBY. AS SUCH...THIS ADDS CONFIDENCE TO WHAT THE GUIDANCE IS SUGGESTING...SO HAVE TRENDED CEILINGS LOWER /IFR AT BWG AND LEX/ BUT THIS MAY NEED TO GO LOWER IN FUTURE UPDATES. THERE MAY ALSO BE REDUCED VISIBILITY...POSSIBLY DENSE FOG AT BWG. THE MAIN PERIOD FOR THE FOG/STRATUS RESTRICTIONS WOULD BE 09-15Z. LOOK FOR SOME GRADUAL IMPROVEMENT WEST TO EAST DURING THE MORNING THURSDAY AS WINDS BECOME NORTHWESTERLY HELPING TO PUSH SLIGHTLY DRIER AIR IN. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ SHORT TERM........ZBT LONG TERM.........AMS AVIATION..........ZBT
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
700 PM CDT THU SEP 10 2015 .AVIATION... FOR THE 11/00Z TAFS...REMNANT FRONTAL BOUNDARY OVER THE SRN TIER SECTIONS OF OUR AREA CONTINUES TO HELP GENERATE SCATTERED SHWRS AND TSTMS...POSING A THREAT TO THE LFK TERMINAL OVER THE NEXT FEW HOURS. THIS CONVECTION HAS SHOWN A TENDENCY TO DRIFT BACK NWRD LATE THIS AFTERNOON BUT EXPECT IT TO REMAIN SOUTH OF OUR I-20 TERMINALS. LIGHT AND VARIABLE WINDS ARE EXPECTED TO PREVAIL AND ALLOW FOR ANOTHER ROUND OF MORNING FOG ON FRIDAY...THICK IN SOME AREAS WITH MVFR/IFR VSBYS LIKELY OCCURRING TOWARD DAYBREAK BEFORE IMPROVING. A STRONGER COLD FRONT WILL ARRIVE INTO THE AREA TOWARD THE END OF THE TAF PERIOD...BRINGING ANOTHER CHANCE OF SHWRS AND TSTMS LATE FRIDAY THROUGH EARLY SATURDAY. /19/ && .PREV DISCUSSION... /ISSUED 234 PM CDT THU SEP 10 2015/ DISCUSSION... FRONTAL BOUNDARY CONTINUES TO BE VERY DIFFUSE LATE THIS AFTERNOON BUT THE LOWER DEWPOINTS ACROSS NORTHERN LOUISIANA SUGGESTS THAT PERHAPS THE BOUNDARY HAS MIXED A LITTLE SOUTH OF THE I-20 CORRIDOR ATTM. SHOWERY CONVECTION FOR THE MOST PART HAS BEEN CONFINED TO AREAS SOUTH OF THE I-20 CORRIDOR...OR ACROSS DEEP EAST TEXAS INTO PORTIONS OF WEST CENTRAL AND EAST CENTRAL LA. FOR TONIGHT... HAVE MAINTAINED CHANCE POPS ACROSS OUR SOUTHERN ZONES WITH SLIGHT CHANCE POPS COVERING THE I-20 CORRIDOR JUST IN CASE SOMETHING WERE TO IGNITE ALONG THE FRONT WHICH THE 12Z NAM STILL SUGGESTS MIGHT HAPPEN EVEN THOUGH THE HRRR HAS BACKED OFF THIS SCENARIO. THIS BOUNDARY WILL CONTINUE TO SERVE AS A FOCUS FOR CONVECTION DURING THE DAY FRIDAY AND GIVEN THE STEEP MID LEVEL LAPSE RATES AND MODERATE INSTABILITY EXPECTED SOUTH OF THE CORRIDOR ON FRIDAY...CANNOT RULE OUT AN ISOLATED STRONG TO SEVERE STORM OR TWO DURING PEAK HEATING. IN ADDITION...SHORTWAVE ENERGY DROPPING QUICKLY OUT OF THE CENTRAL PLAINS INTO THE SOUTHERN PLAINS/MID MISS VALLEY WILL PROVIDE THE UPPER LEVEL SUPPORT NECESSARY FOR INCREASING SHOWERS AND THUNDERSTORMS MOVING INTO OUR REGION FROM THE NORTHWEST. THIS WILL BE THE LEADING EDGE OF THE MUCH COOLER AND DRIER WEATHER FORECAST FOR THE UPCOMING WEEKEND. THE I-20 CORRIDOR WILL LIKELY ENCOUNTER THIS FRONTAL FORCING BY LATE AFTERNOON/EARLY EVENING...THUS THE POSSIBILITY OF A STRONG STORM LATE IN THE DAY. KEPT POPS AT HIGH END CHANCE CATEGORY FOR FRIDAY EVENING WITH THE CONVECTION LIKELY DISSIPATING AFTER MIDNIGHT WITH THE COOLER/DRIER AIR FOLLOWING FROM THE NORTH. COULD SEE TEMPERATURES IN THE UPPER 50S FOR LOWS SATURDAY MORNING WITH HIGHS ON SATURDAY RANGING IN THE 80S WITH MUCH DRIER DEWPOINTS. THE COOLEST MORNING SHOULD BE SUNDAY WITH WIDESPREAD 50S AREAWIDE AND I WOULD NOT BE SURPRISED TO SEE UPPER 40S ACROSS OUR MOST PROTECTED NORTHERN ZONES. RECORDS MAY FALL IF THIS OCCURS. TEMPERATURES SHOULD BEGIN TO MODERATE BY THE FIRST OF NEXT WEEK AS WE SEE RETURNING SOUTHERLY FLOW SETTING UP. ALOFT...WE WILL TRANSITION FROM A NORTHERLY FLOW...TO ZONAL...AND EVENTUAL SOUTHWEST FLOW AS THE NEXT LONGWAVE TROUGH MOVES ONSHORE THE PACIFIC NORTHWEST. WITH UPPER RIDGING FCST TO SETUP ACROSS THE MID ATLANTIC BY THE MIDDLE PART OF NEXT WEEK...WE SHOULD BEGIN TO SEE AT LEAST WIDELY SCATTERED AFTERNOON/EVENING VARIETY CONVECTION WITH A RETURN TO NEAR NORMAL TEMPERATURES. PRELIMS TO FOLLOW...13. && .PRELIMINARY POINT TEMPS/POPS... SHV 73 92 65 84 / 20 30 50 10 MLU 70 92 66 84 / 20 20 50 10 DEQ 66 89 58 81 / 10 40 20 0 TXK 69 91 61 81 / 10 30 40 0 ELD 66 90 60 79 / 10 30 40 0 TYR 73 92 65 84 / 20 30 50 10 GGG 71 92 65 83 / 20 30 50 10 LFK 73 92 69 87 / 30 30 50 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 19
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
250 AM EDT WED SEP 9 2015 .SYNOPSIS... HIGH PRESSURE WILL SLIDE OFF THE MID ATLANTIC COAST TONIGHT THROUGH WEDNESDAY. A COLD FRONT APPROACHES FROM THE NORTHWEST WEDNESDAY...AND SETTLES INTO THE REGION THURSDAY. THE FRONT STALLS OVER NORTH CAROLINA FRIDAY INTO THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... UPDATE...SHOWERS ACROSS INTERIOR NE NC ARE FINALLY TAPERING OFF LATE THIS EVENING AND A LULL IN ACTIVITY IS EXPECTED DURING THE REST OF THE EVENING AND EARLY OVERNIGHT HOURS. PREVIOUS DISCUSSION...PER LATEST RAP GUIDANCE...WEAK VORT MAX LIFTS NEWD OVER ERN VA TONIGHT. HI-RES GUIDANCE INDICATES THE WARM/MOIST AND MODESTLY UNSTABLE AIR MASS MAY PRODUCE SOME ISOLATED SHOWERS OVERNIGHT ACROSS CENTRAL AND ERN VA AS THE VORT LIFTS...ESPECIALLY OVER THE BAY AND ERN SHORE. HOWEVER... CONFIDENCE IS NOT HIGH ATTM...SO WILL LEAVE SLIGHT CHANCE WORDING. A PARTLY CLOUDY SKY AND DISPERSAL WILL LIMIT FOG DEVELOPMENT TONIGHT...BUT WARM/SOUPY AIR MASS SHOULD BE ENOUGH FOR PATCHY FOG IN AREAS THAT RECEIVED RAINFALL EARLIER TODAY. A MILD TONIGHT AHEAD WITH LOWS IN THE LOW 70S. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... UPPER TROUGH DIGS OVER THE GREAT LAKES REGION WEDS AND THU...RESULTING IN HEIGHT FALLS OVER THE MID-ATLANTIC REGION. AN ASSOCIATED COLD FRONT IS EXPECTED TO REACH THE OHIO VALLEY BY WEDS AFTERNOON. LEE/THERMAL TROUGH DEVELOPS OVER THE PIEDMONT IN ADVANCE OF THE FRONT WEDS AFTERNOON. INCREASING SW FLOW WILL ADVECT DEEP LAYERED MOISTURE INTO THE REGION...WITH PWATS PROGGED AOA 2 INCHES (+1 TO +2 STD DEV). WHILE THE MAIN SHEARING VORT ENERGY REMAINS OVER THE OHIO VALLEY...WEAK PERTURBATIONS IN THE SW FLOW WILL PROVIDE SUBTLE FORCING FOR ASCENT OVER THE LOCAL AREA. THETA-E ADVECTION AND DEWPOINTS IN THE LOW 70S WILL RESULT IN BETTER INSTABILITY...WITH MLCAPE ~1500 J/KG. HAVE FAVORED THE PIEDMONT INTO CENTRAL AND EAST CENTRAL VA FOR 30-40 PCT POPS. WARMER TEMPS ALOFT ACROSS THE SE WILL LIMIT OVERALL COVERAGE...SO HAVE CAPPED AT 30 PCT. EFFECTIVE SHEAR PROGGED AROUND 15 TO 20 KT MAY RESULT IN SLIGHT BETTER ORGANIZATION...BUT SEVERE WEATHER IS NOT ANTICIPATED. WARM AND HUMID CONDITIONS PERSIST...WITH HIGHS FORECAST IN THE UPPER 80S TO AROUND 90 (MID 80S ALONG THE COAST). SLIGHT CHANCE TO CHANCE POPS WILL BE MAINTAINED THROUGH WEDNESDAY NIGHT. MILD AGAIN...WITH LOWS IN THE LOW/MID 70S. THE FLOW CONTINUES TO AMPLIFY OVER THE GREAT LAKES AND ERN CONUS THURSDAY AS SHORTWAVE ENERGY REACHES THE MID-ATLANTIC STATES. SFC LOW DEVELOPS ALONG THE FRONT THU MORNING...LIFTING OVER NRN VA INTO THE DELMARVA THU AFTERNOON AND EVENING. EXPECT WIDESPREAD...BENEFICIAL RAINFALL THURSDAY AFTERNOON. A WARM/MOIST AIR MASS REMAINS IN PLACE...BUT INSTABILITY WILL BE LIMITED DUE TO CLOUD COVER AND PRECIP. HAVE RETAINED LIKELY POPS ACROSS ALL BUT THE FAR SE LOCAL AREA. LACK OF ORGANIZED FORCING AND ANOMALOUS FLOW WILL KEEP OVERALL QPF AOB ONE HALF OF AN INCH. WEAK FLOW AND MBE/CORFIDI VECTORS FAVOR LOCALLY HIGHER AMOUNTS. CLOUDS/PRECIP AND HEIGHT/THICKNESS FALLS YIELD TEMPS RANGING FROM THE LOW 80S NW TO UPPER 80S SE. THE FRONT STALLS ALONG THE COAST THU NIGHT AND FRI IN SWLY FLOW ALOFT. BEST MOISTURE AND SHORTWAVE ENERGY LOCATES OVER THE COASTAL PLAIN...AND WILL RETAIN CHANCE POPS ACROSS SOUTHERN VA AND SE VA/NE NC. MORE SEASONABLE CONDITIONS EXPECTED FRI WITH HIGHS IN THE LOW TO MID 80S AND DEWPOINTS COOLING INTO THE LOW 60S NW TO UPPER 60S SE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MODELS CONT TO STRUGGLE WITH A SOLN TO JUST HOW FAR EAST THE FRNTL BNDRY GETS THIS WEEKEND AS IT APPRCHS THE OFFSHORE RIDGE. CONSENSUS IS THAT IT STALLS RIGHT ALONG THE COAST AS SVRL WAVES OF LOW PRS MOVE NE ALONG IT. IN ADDITION...A RTHR POTENT UPR LVL SYSTM PROGGED TO DIVE SE FROM THE GT LAKE RGN LATER THIS WEEKEND. GFS STILL FRTHER SOUTH...BUT IT IS STARTING TO COME IN LINE WITH THE ECMWF SOLN OF SWING THE UPR LVL LOW NORTH OF FA WITH MOST OF THE ENERGY FROM THE VA MTS ON NORTH. APPEARS HIGH PRS MOVG EAST FROM NATIONS MID SECTION WILL BE STRNG ENUF TO PUSH THE ENTIRE SYSTM OFFSHORE ERLY NEXT WK. GIVEN THE ABOVE UNCERTAINTY...WILL KEEP A CONSISTENT FCST AND LEAN MORE TOWARD A ECMWF SOLN. KEPT CHC POPS FRI NITE THRU SUN NITE (HIGHEST POPS ALONG THE COAST AND MENTION THUNDER IN THE IN AFTN AND EVE). DRY MON/TUE. A COOLING TREND THRU THE PRD. HIGHS SAT 80- 85...COOLER AT THE BEACHES. LOWS 60-65. HIGHS SUN/MON 75-80. LOWS M50S-L60S. HIGHS TUE U70S-L80S. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... 06Z TAF PERIOD STARTS OUT WITH VFR CONDS TRANSITIONING TO MVFR/IFR IN SPOTS WITH LIGHT WINDS AND SFC HI PRES IN THE AREA. INCLUDED THIS IN ALL TAFS EXCEPT KORF. CONDS WILL IMPROVE BY MID MORNG EVERYWHERE. THERE WILL BE A CHANCE OF SHRAS/TSTMS FM TDA THRU THE WEEKEND AS A COLD FRNT APPROACHES FM THE W AND STALLS IN THE VICINITY. && .MARINE... NO HEADLINES XPCT AS HIGH PRS MOVES OFFSHORE RESULTING IN A RETURN SLY FLOW THRU THURSDAY. ONCE AGAIN...HIGH RES DATA SUGGESTS SOME CHANNELING UP THE BAY AT NIGHT...SO KEPT SPEEDS AOB 15 KTS FOR NOW. COLD FRONT APPRCHS THE AREA THURSDAY AFTN THEN CROSSES THE WTRS THURSDAY NIGHT BEFORE STALLING JUST OFF THE COAST FRIDAY. LACK OF CAA BEHIND THE FRONT WILL KEEP SUB-SCA CNDTNS INTO FRIDAY. LOCATION OF FRONT INTO THE WEEKEND WILL BE KEY TO THE FCST. RIGHT NOW THE BNDRY LOOKS TO STRADDLE THE COAST KEEPING WNDS IN A GNRL WEST DRCTN AT SPEEDS ARND 10 KTS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...AJZ/SAM NEAR TERM...AJZ/BMD/SAM SHORT TERM...AJZ/SAM LONG TERM...MPR AVIATION...MAS MARINE...MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
320 AM EDT WED SEP 9 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 417 PM EDT TUE SEP 8 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A MID/UPPER LEVEL LOW SPINNING OVER MANITOBA. ONE SHORTWAVE IS LIFTING NE ACROSS NRN ONTARIO TO THE N OF LAKE OF THE WOODS. TAIL END OF THAT WAVE IS GENERATING SHRA/TSRA N OF THE MN/ONTARIO BORDER. CLOSER TO HOME... SHORTWAVE THAT LIFTED ACROSS WI TOWARD ERN UPPER MI BROUGHT WIDESPREAD SHRA/ISOLD TSTMS ACROSS ALL BUT FAR WRN UPPER MI TODAY. THAT ACTIVITY IS MOVING OUT QUICKLY NOW. TO THE W...IT APPEARS THAT THERE ARE 2 BOUNDARIES THAT STILL NEED TO BE WATCHED FOR NEW CONVECTIVE DEVELOPMENT. THE FIRST IS LAKE BREEZE BOUNDARY RUNNING FROM THE E SIDE OF THE KEWEENAW TO CNTRL GOGEBIC COUNTY...AND THE OTHER IS THE COLD FRONT MOVING ACROSS THE WRN PART OF LAKE SUPERIOR. MOSTLY FOLLOWED RECENT RADAR TRENDS TO MOVE LINGERING WIDESPREAD SHRA OUT OF THE ERN FCST AREA OVER THE NEXT FEW HRS. HELD LOW POPS BACK TO THE W AHEAD OF THE TWO AFOREMENTIONED BOUNDARIES. LATEST SPC MESOANALYSIS HAS MLCAPES UP TO AROUND 250J/KG OR SO AND SBCAPE TO AROUND 500J/KG AHEAD OF THE BOUNDARIES. WITH CU BUILDING UP PER VIS SATELLITE IMAGERY...CAN`T RULE OUT ISOLD/SCT SHRA DEVELOPMENT... PERHAPS A TSTM. WHATEVER HAPPENS...PCPN RISK WILL BE DONE BY LATE EVENING AS COLD FRONT SWEEPS ACROSS THE AREA. MUCH DRIER AIR MASS SURGING INTO THE AREA WILL FINALLY BRING AN END TO THE UNSEASONABLY LONG STRETCH OF HIGH DWPTS FOR THIS TIME OF YEAR. UPSTREAM IN NRN MN...SFC DWPTS HAVE FALLEN THRU THE 40S WITH EVEN SOME 30S SHOWING UP. EXPECT CLEARING SKIES FROM THE W TONIGHT. IF THERE IS ANY FOG ON LAKE SUPERIOR...IT WILL AFFECT THE ERN SHORELINE AREAS BEFORE BEING SWEPT CLEAR BY THE MUCH DRIER AIR MASS. IT WILL BE THE COOLEST NIGHT IN WELL OVER A WEEK. MIN TEMPS SHOULD FALL INTO THE MID 40S OVER THE INTERIOR W HALF AND MOSTLY LOW/MID 50S ELSEWHERE. DRY AIR MASS WILL SET UP A NICE WED UNDER PLENTY OF SUNSHINE. DWPTS WILL BE LOW...MOSTLY IN THE 40S...WITH HIGH TEMPS IN THE UPPER 60S TO MID 70S...WARMEST IN THE AREAS THAT SEE DOWNSLOPING UNDER A WESTERLY WIND. SPEAKING OF WHICH...WINDS SHOULD BE GUSTY INTO THE 20 TO 30 MPH RANGE...ESPECIALLY OVER THE NW FCST AREA. .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 320 AM EDT WED SEP 9 2015 NAM SHOWS A BROAD 500MB TROUGH OVER THE UPPER GREAT LAKES AND EASTERN U.S. WITH A RIDGE IN THE WESTERN U.S. THIS TROUGH DEEPENS WITH TIME AND THE TROUGH AXIS MOVES ACROSS THE UPPER GREAT LAKES ON FRI. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE MOVING ACROSS THE AREA ON THU WITH DEEPER MOISTURE ACROSS THE SOUTHERN HALF OF THE CWA. LAKE EFFECT COMES INTO PLAY THIS FORECAST PERIOD AS OPEN LAKE TEMPERATURES RANGE FROM 12C TO 15C AND 850 MB TEMPERATURES DROP TO 2C TO 4C THU NIGHT AND FRI AND THIS IS ENOUGH DELTA-T COMBINED WITH SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE TO AT LEAST KEEP IN SLIGHT CHANCE TO LOW CHANCE POPS THU NIGHT AND FRI AND ALSO A BIT MORE CLOUD COVER DUE TO LAKE EFFECT CLOUDS. FOR THU...KEPT HIGHEST POPS IN THE SOUTH WITH BEST MOISTURE IN THAT AREA AND DRY IN THE FAR NORTHERN CWA. OTHERWISE...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST OR FOR TEMPERATURES. IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE UPPER GREAT LAKES EMBEDDED IN A DEEP TROUGH OVER THE EASTERN U.S. 12Z SAT WITH A RIDGE OVER THE WESTERN U.S. THIS TROUGH MOVES SLOWLY EAST 12Z SUN WITH THE RIDGE OVER THE WESTERN U.S. GETTING FLATTENED WITH TIME. BY 12Z MON...RIDGE IS FLATTENED ENOUGH TO CAUSE ZONAL FLOW OVER THE UPPER GREAT LAKES MON. A TROUGH MOVES ONTO THE WEST COAST 12Z TUE WITH ZONAL FLOW CONTINUING OVER THE UPPER GREAT LAKES ON TUE. TEMPERATURES WILL STAY ABOVE NORMAL THIS FORECAST PERIOD AND WILL GO DRY SAT THROUGH SUN NIGHT AND THEN A WEAK COLD FRONT STALLS OUT OVER THE AREA FOR MON INTO TUE WITH LIMITED MOISTURE AVAILABLE TO WORK WITH. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 119 AM EDT WED SEP 9 2015 EXPECT VFR CONDITIONS THROUGH WEDNESDAY. MID CLOUDS INCREASE ON WEDNESDAY EVENING WITH SOME RAIN POSSIBLE LATER WEDNESDAY NIGHT. GUSTY WINDS ARE EXPECTED AT ALL THE TAF SITES ON WEDNESDAY DURING PEAK MIXING OF THE DAY. STRONGEST WIND GUSTS OVER 25 KTS WILL BE AT THE MORE EXPOSED KCMX LOCATION. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 417 PM EDT TUE SEP 8 2015 FIRST UP...IF THERE IS ANY FOG ON LAKE SUPERIOR...IT WILL BE SWEPT OFF THE ERN PORTION OF THE LAKE TONIGHT AS STRENGTHENING W WINDS BEHIND A PASSING COLD FRONT USHER IN A MUCH DRIER AIR MASS TONIGHT. INCOMING PRES RISES WILL HELP BOOST W WIND GUSTS TO 25-30KT FOR A TIME AFTER FRONTAL PASSAGE. DURING WED...W WINDS OF 15-25KT WILL GENERALLY BE THE RULE...BUT OVER CNTRL LAKE SUPERIOR AND IN PARTICULAR AROUND THE TIP OF THE KEWEENAW PENINSULA...WINDS OF 20- 30KT ARE EXPECTED. LIGHTER WINDS OF 10-20KT ARE EXPECTED FOR WED NIGHT/THU. ARRIVAL OF A COLDER AIR MASS AHEAD OF APPROACHING SFC HIGH PRES WILL LEAD TO A PERIOD OF STRONGER WINDS OF 15-30KT AGAIN THU NIGHT INTO AT LEAST FRI MORNING...STRONGEST OVER THE E HALF. WINDS WILL SLOWLY DIMINISH W TO E FRI AFTN THRU SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...07 AVIATION...JLA MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
119 AM EDT WED SEP 9 2015 .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 417 PM EDT TUE SEP 8 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A MID/UPPER LEVEL LOW SPINNING OVER MANITOBA. ONE SHORTWAVE IS LIFTING NE ACROSS NRN ONTARIO TO THE N OF LAKE OF THE WOODS. TAIL END OF THAT WAVE IS GENERATING SHRA/TSRA N OF THE MN/ONTARIO BORDER. CLOSER TO HOME... SHORTWAVE THAT LIFTED ACROSS WI TOWARD ERN UPPER MI BROUGHT WIDESPREAD SHRA/ISOLD TSTMS ACROSS ALL BUT FAR WRN UPPER MI TODAY. THAT ACTIVITY IS MOVING OUT QUICKLY NOW. TO THE W...IT APPEARS THAT THERE ARE 2 BOUNDARIES THAT STILL NEED TO BE WATCHED FOR NEW CONVECTIVE DEVELOPMENT. THE FIRST IS LAKE BREEZE BOUNDARY RUNNING FROM THE E SIDE OF THE KEWEENAW TO CNTRL GOGEBIC COUNTY...AND THE OTHER IS THE COLD FRONT MOVING ACROSS THE WRN PART OF LAKE SUPERIOR. MOSTLY FOLLOWED RECENT RADAR TRENDS TO MOVE LINGERING WIDESPREAD SHRA OUT OF THE ERN FCST AREA OVER THE NEXT FEW HRS. HELD LOW POPS BACK TO THE W AHEAD OF THE TWO AFOREMENTIONED BOUNDARIES. LATEST SPC MESOANALYSIS HAS MLCAPES UP TO AROUND 250J/KG OR SO AND SBCAPE TO AROUND 500J/KG AHEAD OF THE BOUNDARIES. WITH CU BUILDING UP PER VIS SATELLITE IMAGERY...CAN`T RULE OUT ISOLD/SCT SHRA DEVELOPMENT... PERHAPS A TSTM. WHATEVER HAPPENS...PCPN RISK WILL BE DONE BY LATE EVENING AS COLD FRONT SWEEPS ACROSS THE AREA. MUCH DRIER AIR MASS SURGING INTO THE AREA WILL FINALLY BRING AN END TO THE UNSEASONABLY LONG STRETCH OF HIGH DWPTS FOR THIS TIME OF YEAR. UPSTREAM IN NRN MN...SFC DWPTS HAVE FALLEN THRU THE 40S WITH EVEN SOME 30S SHOWING UP. EXPECT CLEARING SKIES FROM THE W TONIGHT. IF THERE IS ANY FOG ON LAKE SUPERIOR...IT WILL AFFECT THE ERN SHORELINE AREAS BEFORE BEING SWEPT CLEAR BY THE MUCH DRIER AIR MASS. IT WILL BE THE COOLEST NIGHT IN WELL OVER A WEEK. MIN TEMPS SHOULD FALL INTO THE MID 40S OVER THE INTERIOR W HALF AND MOSTLY LOW/MID 50S ELSEWHERE. DRY AIR MASS WILL SET UP A NICE WED UNDER PLENTY OF SUNSHINE. DWPTS WILL BE LOW...MOSTLY IN THE 40S...WITH HIGH TEMPS IN THE UPPER 60S TO MID 70S...WARMEST IN THE AREAS THAT SEE DOWNSLOPING UNDER A WESTERLY WIND. SPEAKING OF WHICH...WINDS SHOULD BE GUSTY INTO THE 20 TO 30 MPH RANGE...ESPECIALLY OVER THE NW FCST AREA. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 414 PM EDT TUE SEP 8 2015 THE UPPER TROUGH THAT IS CURRENTLY MOVING EAST ACROSS SOUTH CENTRAL CANADA AND THE UPPER MISSISSIPPI VALLEY WILL MOVE INTO THE UPPER GREAT LAKES OVER THE NEXT 12 HOURS AND THEN AMPLIFY OVER THE REGION HEADING INTO THE END OF THE WORK WEEK AS A WAVE CURRENTLY MOVING INTO BRITISH COLUMBIA ROTATES THROUGH. THIS SETUP WILL LEAD TO GENERALLY BELOW NORMAL TEMPERATURES INTO THE START OF THE WEEKEND WITH PERIODS OF SHOWERS. AFTER A DRY START TO THE LONG TERM PERIOD ON WEDNESDAY EVENING (DUE TO AN EXISTING HIGH PRESSURE RIDGE)...A WEAK SURFACE TROUGH WILL MOVE EAST ACROSS THE UPPER MISSISSIPPI VALLEY AND INTO THE GREAT LAKES REGION LATER WEDNESDAY NIGHT AND THURSDAY. THIS WILL BE IN RESPONSE TO THE SHORTWAVE CURRENTLY MOVING INTO BRITISH COLUMBIA THAT WILL BE ROUNDING THE BASE OF THE UPPER TROUGH. SHOWERS ARE EXPECTED TO DEVELOP IN SOUTHERN MINNESOTA AND WESTERN WISCONSIN ON WEDNESDAY NIGHT AND THEN SPREADING EAST-NORTHEAST INTO PORTIONS OF UPPER MICHIGAN. MODELS ARE DIFFERING ON THE NORTHWEST EXTENT OF THE SHOWERS...LARGELY DUE TO THE TRACK OF THE SHORTWAVE WITH HALF TRACKING IT ACROSS NORTHERN WISCONSIN (PUSHING PRECIP FARTHER NORTH) AND THE OTHER HALF TRACK IT MORE ACROSS SOUTHERN WISCONSIN (AND HAS PRECIP ONLY BRUSHING THE SOUTHERN THIRD OF THE AREA) ON THURSDAY. DID SEE A SOUTHEAST TREND WITH THE 12Z ECMWF...WHICH IS MORE IN LINE WITH THE 12Z GFS/GEM...SO WHILE CONFIDENCE IS LOW...FELT IT WAS REASONABLE TO TREND THE CHANCE POPS FARTHER TO THE SOUTHEAST AND MORE OVER THE SOUTH CENTRAL AND ALONG THE LAKE MICHIGAN SHORELINE. THOSE SHOWERS WILL DEPART ON THURSDAY NIGHT AS THE SHORTWAVE AND SURFACE TROUGH DEPARTS. THIS WILL ALLOW MUCH COLDER AIR TO SURGE SOUTH ACROSS THE AREA THURSDAY NIGHT INTO FRIDAY...WITH 850MB TEMPS FALLING TO 1-2C. SINCE LAKE SUPERIOR TEMPERATURES ARE IN THE 12-18C RANGE...EXPECT SOME POTENTIAL OF LAKE EFFECT/ENHANCED RAIN FOR THURSDAY NIGHT INTO FRIDAY. MODELS SHOWING DECENT MOISTURE BELOW THE INVERSION AROUND 750MB...SO HAVE CHANCE POPS FOR THE FAVORED NORTHERLY WIND LOCATIONS NEAR LAKE SUPERIOR DURING THAT TIME. WILL LIKELY NEED TO TREND POPS UP FURTHER IF THE LATEST MODEL TRENDS CONTINUE. IN ADDITION...THAT COLD AIR AND DECENT CLOUD COVER FOR MUCH OF THE DAY ON FRIDAY WILL KEEP HIGHS IN THE 50S. A SURFACE HIGH OFF TO THE WEST IN THE DAKOTAS WILL TRY TO PUSH A SURFACE RIDGE INTO THE AREA ON FRIDAY...BUT IT WILL LIKELY REALLY ARRIVE ON SATURDAY AS THE UPPER TROUGH BEGINS TO SHIFT EAST. DRIER AIR ASSOCIATED WITH THE HIGH WILL LEAD TO DECREASING CLOUDS FROM WEST TO EAST ON FRIDAY AFTERNOON...WITH CLEAR SKIES REMAINING IN PLACE THROUGH MUCH OF THE WEEKEND. SATURDAY WILL REMAIN BELOW NORMAL FOR HIGHS...BUT WITH THE UPPER RIDGE AXIS SHIFTING EAST FROM THE DAKOTAS AND INTO THE UPPER GREAT LAKES REGION FOR SUNDAY AND MONDAY...EXPECT HIGHS TO RISE BACK UP TO NORMAL OR EVEN SLIGHTLY ABOVE NORMAL VALUES. WILL NEED TO WATCH THE EVOLUTION OF THE UPPER TROUGH JUST TO THE EAST-SOUTHEAST OF THE AREA FOR SUNDAY/MONDAY TIME FRAME...AS THERE ARE SOME HINTS OF IT ROTATING BACK NORTHWEST AS THE UPPER RIDGE REMAINS FARTHER WEST. THAT WOULD LEAD TO COOLER AND BETTER OPPORTUNITIES FOR RAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 119 AM EDT WED SEP 9 2015 EXPECT VFR CONDITIONS THROUGH WEDNESDAY. MID CLOUDS INCREASE ON WEDNESDAY EVENING WITH SOME RAIN POSSIBLE LATER WEDNESDAY NIGHT. GUSTY WINDS ARE EXPECTED AT ALL THE TAF SITES ON WEDNESDAY DURING PEAK MIXING OF THE DAY. STRONGEST WIND GUSTS OVER 25 KTS WILL BE AT THE MORE EXPOSED KCMX LOCATION. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 417 PM EDT TUE SEP 8 2015 FIRST UP...IF THERE IS ANY FOG ON LAKE SUPERIOR...IT WILL BE SWEPT OFF THE ERN PORTION OF THE LAKE TONIGHT AS STRENGTHENING W WINDS BEHIND A PASSING COLD FRONT USHER IN A MUCH DRIER AIR MASS TONIGHT. INCOMING PRES RISES WILL HELP BOOST W WIND GUSTS TO 25-30KT FOR A TIME AFTER FRONTAL PASSAGE. DURING WED...W WINDS OF 15-25KT WILL GENERALLY BE THE RULE...BUT OVER CNTRL LAKE SUPERIOR AND IN PARTICULAR AROUND THE TIP OF THE KEWEENAW PENINSULA...WINDS OF 20- 30KT ARE EXPECTED. LIGHTER WINDS OF 10-20KT ARE EXPECTED FOR WED NIGHT/THU. ARRIVAL OF A COLDER AIR MASS AHEAD OF APPROACHING SFC HIGH PRES WILL LEAD TO A PERIOD OF STRONGER WINDS OF 15-30KT AGAIN THU NIGHT INTO AT LEAST FRI MORNING...STRONGEST OVER THE E HALF. WINDS WILL SLOWLY DIMINISH W TO E FRI AFTN THRU SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...JLA MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
908 PM CDT THU SEP 10 2015 .UPDATE...MOST PRECIP HAS ENDED FOR NOW ACROSS THE CWA...SO CUT POPS SLIGHTLY FOR THIS EVENING. THE LATEST HRRR STILL INDICATES THAT SOME SHOWERS COULD REDEVELOP LATER TONIGHT IN THE VICINITY OF THE BOUNDARY...SO WILL LEAVE THE SLIGHT CHANCE POPS OVERNIGHT ACROSS THE SOUTHERN ZONES. THE ONLY OTHER CHANGE TO THE CURRENT FORECAST WAS TO SLIGHTLY ADJUST THE HOURLY TEMPS FOR THIS EVENING. /27/ && .AVIATION...SHOWERS AND THUNDERSTORMS HAVE DISSIPATED FOR THE EVENING BUT SOME LIGHT SHOWERS MAY BE POSSIBLE OVERNIGHT ALONG AND SOUTH OF A STALLED BOUNDARY ACROSS THE REGION. MOST SITES NORTH OF THE BOUNDARY(I.E. ALONG AND NORTH OF THE I-20 CORRIDOR) SHOULD REMAIN VFR THROUGH THE NIGHT BUT MVFR VIS RESTRICTIONS WILL BE POSSIBLE ESPECIALLY SOUTH OF THE BOUNDARY MAINLY 09-13Z. ADDITIONAL SHOWERS AND STORMS WILL BE POSSIBLE TOMORROW AHEAD OF ANOTHER COLD FRONT. THIS COULD BRING MVFR VIS/CEILING RESTRICTIONS DURING THE AFTERNOON. /28/ && .PREV DISCUSSION... /ISSUED 318 PM CDT THU SEP 10 2015/ DISCUSSION...COLD FRONT...ALONG AN ELD...GWO...CBM LINE AT 19Z...WILL CONTINUE TO LIMP SOUTH TONIGHT WITH SCATTERED SHOWERS AND THUNDERSTORMS ALONG AND SOUTH OF IT...MAINLY DURING THE EVENING. THE FRONT WILL TEMPORARILY STALL OVER THE FAR SOUTH TOWARD MORNING. MEANWHILE...IMPRESSIVE MID LEVEL TROF DIGGING OVER THE MS VALLEY TONIGHT WILL PUSH A STRONG COLD FRONT INTO THE AREA BY FRIDAY AFTERNOON. WHILE THE BEST COVERAGE OF STORMS LOOKS TO BE OVER THE SOUTH IN PROXIMITY TO STALLED BOUNDARY...INCOMING COLD FRONT SHOULD BE CLOSE ENOUGH BY MID/LATE AFTERNOON TO FIRE OFF A GOOD SCATTERING OF SHOWERS AND A FEW THUNDERSTORMS OVER THE NORTH. THE FRONT WILL CONTINUE A STRONG SOUTHWARD PUSH WITH CONVECTION PUSHING THROUGH THE MAJORITY OF THE FORECAST AREA DURING THE EVENING AND OVERNIGHT. THE EXCEPTION WILL BE THE FAR SE WHERE CONVECTION WILL CONTINUE INTO SATURDAY MORNING...BUT EXPECT THIS AREA TO EXIT BEFORE NOON. MUCH COOLER/DRIER AIR WILL POUR INTO THE REGION LATE FRIDAY NIGHT/SATURDAY. WHILE WOULD NOT NECESSARILY EXPECT A GOOD RADIATIONAL COOLING NIGHT WITH SURFACE HIGH PRESSURE STILL TO THE NORTHWEST OF THE AREA...OVER AR...AND EXPECTED COLD AIR ADVECTION CONTINUING SATURDAY NIGHT...LOW TO MID 40S DEWPOINTS WILL HAVE ALREADY BEEN RESIDENT OVER THE AREA SOME 6-8 HOURS BEFORE DAWN SUNDAY. THUS...WITH SUCH DRY AIR AND RELATIVELY LIGHT WINDS OVERNIGHT...THINK DECOUPLING WILL OCCUR RESULTING IN TEMPS FALLING OFF TO THEIR LOWEST POTENTIAL OF LOW TO MID 50S. WHILE THE CENTER OF THE SURFACE HIGH PRESSURE WILL MOVE EAST INTO THE TN VALLEY SUNDAY NIGHT...RIDGE AXIS WILL EXTEND SW FROM THERE ACROSS THE CWA. LIGHT WINDS DURING THE EARLY EVENING ALONG WITH CONTINUED DRY AIR WILL ALLOW FOR ANOTHER GOOD RADIATIONAL COOLING NIGHT AND TEMPS TO ONCE AGAIN FALL INTO THE LOW TO MID 50S./26/ CONCERNING STORM POTENTIAL FRIDAY EVENING...THERE IS A STRONG SIGNAL IN THE GUIDANCE FOR AT LEAST A BROKEN LINE OF STORMS TO DEVELOP AHEAD OF THE COLD FRONT EARLY FRIDAY EVENING OVER NORTHERN PORTIONS OF THE ARKLAMISS. THE TIMING SUGGESTS THERE MAY BE SOME IMPACTS...MAINLY DUE TO LIGHTNING...FOR OUTDOOR ACTIVITIES DURING THAT TIME FRAME. FOR NOW THE MODEL CONSENSUS IS THAT THERE WILL BE FAIRLY STEEP MID LEVEL LAPSE RATES (H850-500 6.5 TO 7 DEG C/KM)...BUT BOUNDARY LAYER QUALITY WILL BE RELATIVELY LOW GIVEN THE DRIER DEWPOINTS PRECEDING THE FRONTAL CONVERGENCE AND EXPECT MIXED- LAYER BASED INSTABILITY TO BE WEAK. THE COMBINATION OF LIFT AND DEEP LAYER FLOW SHOULD BE SUFFICIENT FOR MULTICELL CONVECTION...AND 0-3KM SHEAR VECTORS OF 15-20KTS MAY SUPPORT A FEW STRONG WIND GUSTS WHERE ANY FAVORABLE SECTOR/SEGMENT ORIENTATION OCCURS. WILL HOLD OFF ON ANY EXPLICIT MENTION OF STRONG/SEVERE STORMS IN HWO/GRAPHICS GIVEN QUESTIONABLE INSTABILITY. /EC/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 71 87 66 80 / 21 34 51 13 MERIDIAN 70 87 66 80 / 27 30 55 17 VICKSBURG 72 87 64 80 / 20 33 41 13 HATTIESBURG 72 86 69 82 / 30 55 31 28 NATCHEZ 71 85 67 79 / 30 47 37 16 GREENVILLE 69 89 62 77 / 13 44 35 13 GREENWOOD 68 87 61 77 / 13 48 48 13 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
654 PM CDT THU SEP 10 2015 .UPDATE: Issued at 623 PM CDT Thu Sep 10 2015 Have increased PoPs across ern portions of the CWA where TSRA continue to drop swd into the region. Outflow boundaries will continue to make wwd extent of precip challenging, but believe bulk of precip will remain E of the Mississippi River. Storms shud weaken with sunset. Minimal svr threat continues. Remainder of forecast for tonight currently appears to be on track. && .SHORT TERM: (Through Late Tonight) Issued at 338 PM CDT Thu Sep 10 2015 Spotty convection will continue across most of the FA early this evening due to numerous outflow/surface boundaries migrating through mostly unstable airmass of MLCAPES 1000-2000 j/kg. However, still believe the primary "show" will be late this evening and overnight as primary shortwave energy digs into the region and begins to interact with southward sagging cold front/baroclinic zone. Last several runs of the HRRR continue to support idea that convection over NE will drop/develop across e KS and w MO during the early evening hours as UVV increases due to shortwave as well as increasing isentropic ascent, with the resultant elevated shower and embedded thunderstorm threat overspreading much of the CWA during the overnight hours. Have highest PoPs (~80%) over mid MO where lift and moisture advection should be maximized...this is a bit higher/bit further north than earlier forecast, but models are still indicating good divergence developing across northern MO in the RRQ of the back building upper level jet. PoPs then taper off to high chance over far northern and southern sections of the FA as precip should tend to "fade" a bit as it advects out of the primary zone of ascent. Truett .LONG TERM: (Friday through Next Thursday) Issued at 338 PM CDT Thu Sep 10 2015 Even though frontal boundary will be south of forecast area by 12z Friday, will see some lingering post frontal precipitation gradually tapering off from north to south, including some isolated thunderstorms. Otherwise, colder air to filter into the region and with plenty of cloud cover and rain, temperatures will only rise into the upper 60s to mid 70s. Dry and colder weather to prevail through the weekend. Could see a stray shower on Saturday as decent shortwave energy rotates around upper level trof that is anchored over the Great Lakes. For now have dry conditions, but will need to keep an eye on the models as we get closer to this time period. By Sunday night surface ridge will begin to move off to the southeast. This will allow southerly winds to return once again and temperatures moderate back into the 80s by Tuesday. Extended models hinting at another cold front moving through region beginning Wednesday night. Have low chance pops Wednesday night and Thursday. Byrd && .AVIATION: (For the 00z TAFs through 00z Friday Evening) Issued at 654 PM CDT Thu Sep 10 2015 An outside chance of TSRA affecting STL metro sites thru 02z from outflow kicking out of central IL and moving SW and will watch closely. Otherwise, VFR and dry until rain with some imbedded TSRA develops, fills in, and expands eastward overnight, reaching UIN and COU by midnight and STL metro sites by 08-09z. Some lower VSBYs possible but for the most part looks like a solid area of stratiform light, possibly briefly moderate, rain for several hours once it moves in. Due to cold front also moving thru near the initial onset and much of the rain on the cool side of the front, should also see low sub-VFR clouds form as well and current suite of TAFs appear to have this well in hand. Rain and low clouds to move out later Friday morning or midday, leaving behind VFR conditions and gusty N-NW winds in its wake. Specifics for KSTL: previous TAF looked to have trends well in hand and made few adjustments, notably expanding VCTS timing to deeper into the night and adding gusty NW winds. Otherwise highlights center around cold FROPA within a couple hours of initial rain onset late tonight with deteriorating conditions that carry well into Friday morning. For now left the IFR out but there is an outside chance for that. Watching closely the slowly approaching TSRA from the north that may warrant an amendment as they develop along an old outflow from central IL. TES && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
631 PM CDT THU SEP 10 2015 .UPDATE: Issued at 623 PM CDT Thu Sep 10 2015 Have increased PoPs across ern portions of the CWA where TSRA continue to drop swd into the region. Outflow boundaries will continue to make wwd extent of precip challenging, but believe bulk of precip will remain E of the Mississippi River. Storms shud weaken with sunset. Minimal svr threat continues. Remainder of forecast for tonight currently appears to be on track. && .SHORT TERM: (Through Late Tonight) Issued at 338 PM CDT Thu Sep 10 2015 Spotty convection will continue across most of the FA early this evening due to numerous outflow/surface boundaries migrating through mostly unstable airmass of MLCAPES 1000-2000 j/kg. However, still believe the primary "show" will be late this evening and overnight as primary shortwave energy digs into the region and begins to interact with southward sagging cold front/baroclinic zone. Last several runs of the HRRR continue to support idea that convection over NE will drop/develop across e KS and w MO during the early evening hours as UVV increases due to shortwave as well as increasing isentropic ascent, with the resultant elevated shower and embedded thunderstorm threat overspreading much of the CWA during the overnight hours. Have highest PoPs (~80%) over mid MO where lift and moisture advection should be maximized...this is a bit higher/bit further north than earlier forecast, but models are still indicating good divergence developing across northern MO in the RRQ of the back building upper level jet. PoPs then taper off to high chance over far northern and southern sections of the FA as precip should tend to "fade" a bit as it advects out of the primary zone of ascent. Truett .LONG TERM: (Friday through Next Thursday) Issued at 338 PM CDT Thu Sep 10 2015 Even though frontal boundary will be south of forecast area by 12z Friday, will see some lingering post frontal precipitation gradually tapering off from north to south, including some isolated thunderstorms. Otherwise, colder air to filter into the region and with plenty of cloud cover and rain, temperatures will only rise into the upper 60s to mid 70s. Dry and colder weather to prevail through the weekend. Could see a stray shower on Saturday as decent shortwave energy rotates around upper level trof that is anchored over the Great Lakes. For now have dry conditions, but will need to keep an eye on the models as we get closer to this time period. By Sunday night surface ridge will begin to move off to the southeast. This will allow southerly winds to return once again and temperatures moderate back into the 80s by Tuesday. Extended models hinting at another cold front moving through region beginning Wednesday night. Have low chance pops Wednesday night and Thursday. Byrd && .AVIATION: (For the 18z TAFs through 18z Friday Afternoon) Issued at 1255 PM CDT Thu Sep 10 2015 SCT to occasionally BKN CU field with bases aoa 4kft expected across the FA this afternoon. There appears to be two areas of potential convection for this afternoon...one is associated with weak convergence along cold front/surface trof that will be drifting into the KUIN area this afternoon, and have maintained VCTS for several hours in KUIN TAF in the late afternoon and early evening hours for this threat. Second area is isolated/AMS-type convection forming ahead of shortwave now entering STL Metro. Have maintained a dry forecast at all metro area TAFs for now, but getting a few cells forming to the NW of the area, and if they hold together/intensify may need to nowcast this threat into some of the metro TAFS. However, still believe the primary threat of convection during this TAF period will be late this evening and overnight, as discussed in Short-term AFD update. Like the trends suggested by the 15z HRRR, and have trended onset of precip and potential thunderstorm activity based on this output. Both NAM and GFS MOS suggest cigs lowering to IFR in the primary rain area along and I-70 corridor during the predawn hours...haven`t gone quite this low, but given time of year and post-frontal cool air...low end MVFR certainly seems reasonable. Specifics for KSTL: Scattered CU with bases aoa 4kft expected this afternoon. AMS-type storms will dot the area, but will isolated coverage will monitor their trends and use nowcast techniques to determine if these will impact TAF area. Much larger of area of rain and embedded thunderstorms expected to work into the area after 06z, with ceilings in the stratus and rain deteriorating to low-end MVFR by daybreak Friday. Truett && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1202 AM CDT WED SEP 9 2015 .UPDATE: Issued at 850 PM CDT Tue Sep 8 2015 Have updated forecast to pull precip further S as cdfnt continues to slowly move swd. Precip along the fnt shud fill in a little more to the E over night. Overall, have trended twd the RAP soln which keeps most of the precip across sern portions of the CWA by sunrise Wed morning. && .SHORT TERM: (Through Late Tonight) Issued at 210 PM CDT Tue Sep 8 2015 Cold front really struggling to make too much progress south today and is currenlty aligned from near Kansas City to the Quad Cities. Precipitation trends remain the focus for the forecast. Area of showers and thunderstorms continue to slowly progress south on outflow from last nights convection that occurred to our northwest. This is well out ahead of the front and away from any deep layer flow aloft so severe chances have been largely removed. More convection is forming back across central Kansas and think this wave of precipitation will replace ongoing activity overnight and into tomorrow morning. CVKING .LONG TERM: (Wednesday through Next Tuesday) Issued at 210 PM CDT Tue Sep 8 2015 Upper level trof axis, currently extending from the upper Midwest to the central Plains, will move east over the next 24 hours forcing the cold front south through the area and ending the threat of precipiation from northwest to southeast. Temperatures should cool to near normal values Wednesday and Thursday before a stronger cold front arrives Thursday night and Firday. Have some chance PoPs with the front, but think focus may remain west of the CWA. Autumn temperatures arrive for the weekend with highs in the 70s and lows dipping into the upper 40s and lower 50s. CVKING && .AVIATION: (For the 06z TAFs through 06z Wednesday Night) Issued at 1157 PM CDT Tue Sep 8 2015 Cold front is still approaching KCOU, and is south of KUIN. Broken line of SHRA/TSRA continues to fire along it and different waves should continue to develop and dissipate over the next several hours. Low CIGs continue to develop with expanded area of IFR now looking likely for STL metro and back to KCOU and have placed in the 06z TAF issuance for overnight and Wednesday morning. These IFR CIGs will then be slow to pull out, with non-VFR CIGs expected well into the day Wednesday with diurnal enhancements as it becomes more of a broken cumulus cloud field. Eventually clearing is anticipated by Wednesday evening. Winds will be light throughout, becoming northerly behind front. Specifics for KSTL: conditions on their way down with IFR now expected later tonight and to continue into Wednesday morning before gradual improvement, with MVFR CIGs hanging on into the afternoon, with a return to VFR conditions is expected by nightfall Wednesday night. TES && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
614 PM CDT THU SEP 10 2015 .UPDATE... ISSUED AT 613 PM CDT THU SEP 10 2015 JUST CANCELLED THE SEVERE THUNDERSTORM WATCH FOR HAYES...FRONTIER...CUSTER AND LINCOLN COUNTIES. THUNDERSTORMS HAVE MOVED SOUTH AND EAST OF THE AREA...WITH A FAIRLY STABLE BOUNDARY LAYER NOTED ACROSS SWRN AND PORTIONS OF CENTRAL NEBRASKA. SOME LIGHT RAIN SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE NERN CWA FOR THE NEXT 1 TO 2 HRS AND WILL BE UPDATING THE FORECAST WHEN THIS ACTIVITY CLEARS THE AREA. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 323 PM CDT THU SEP 10 2015 STRONG TO LOCALLY SEVERE THUNDERSTORMS ARE THE PRIMARY CONCERN GOING IN THE NEAR TERM...WITH THE MAIN THREAT AREA FOR SEVERE WEATHER MAINLY ACROSS OUR FAR SOUTHEASTERN ZONES. LARGE SCALE FORCING IN ASSOCIATION WITH NORTHERN PLAINS IMPULSE HAS ALREADY SPARKED OFF SHOWERS AND A FEW STRONG THUNDERSTORMS THIS AFTERNOON. DEVELOPMENT HAVE BEEN NOTICED ACROSS OUR NORTHERN ZONES WHERE THE ATMOSPHERE IS CHARACTERIZED AS WEAKLY UNSTABLE. A SECOND AREA OF DEVELOPMENT APPEARS TO BE ALONG A MID-LEVEL FRONT ACROSS SOUTHEASTERN CUSTER COUNTY WEST INTO THE SANDHILLS AND THE THIRD IS ACROSS FAR SOUTHWEST NEBRASKA /EAST OF MCK/. THIS DEVELOPMENT IS FOCUSING ALONG A DRY LINE. WILL NEED TO MONITOR OUR SOUTHEASTERN ZONES AS THEY LIE IN A FAVORABLE REGION FOR SUPERCELL DEVELOPMENT. MESOANALYSIS FROM ACROSS OUR SOUTHEASTERN ZONES REVEALS AMPLE INSTABILITY...WITH SBCAPES ESTIMATED AT 3500 J/KG WITH FAVORABLE INCREASING/VEERING WINDS ALOFT ACROSS MUCH OF FRONTIER COUNTY. THE SPC SIGNIFICANT HAIL PARAMETER INDICATES A BULLSEYE OF 3 ALONG THE LINCOLN/FRONTIER COUNTY LINE AND A 2 OVER MUCH OF OUR SOUTHEASTERN ZONES. THE SUPERCELL COMPOSITE GENERALLY FAVORS THE SAME AREA. LARGE HAIL IS THE PRIMARY CONCERN WHERE STORMS FORM ACROSS OUR SOUTHEASTERN ZONES. LATEST HRRR GUIDANCE IS PICKED UP ON THE SB CONVECTION ACROSS OUR FAR SOUTHEASTERN ZONES WELL IN PREVIOUS RUNS...BUT LARGELY IGNORED THE MID-LEVEL FRONT /ELEVATED CONVECTION OVER THE SANDHILLS EAST THROUGH CUSTER COUNTY/ UNTIL THE MOST RECENT RUN. THE MODEL HAS BEEN STEADY THOUGH SUGGESTING THE POTENTIAL SEVERE ACTIVITY SOUTHEAST OF THE FORECAST AREA SHORTLY AFTER 22Z. FOR THE NORTHERN SHOWERS AND WEAK STORMS...THE FORCING WILL QUICKLY SHIFT EAST THIS EVENING...WITH THE SHOWERS EXPECTED TO BE OVER BY MID-EVENING. POST FRONTAL CONDITIONS WILL PROVIDE FOR A DRY AND COOL DAY ACROSS THE CENTRAL PLAINS ON FRIDAY. HIGHS ARE FORECAST TO WARM INTO THE 60S TO LOWER 70S ACROSS THE FORECAST AREA. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 323 PM CDT THU SEP 10 2015 FOR FRIDAY NIGHT AND SATURDAY...AN AMPLIFIED NWRLY FLOW ALOFT WITH A RETURN OF SOUTHERLY WINDS WITH HIGHS WARMING TO THE LOWER 80S ACROSS THE WEST WHILE THE EAST REMAINS IN THE LOWER TO MID 70S. ON SUNDAY...A BROAD TROUGH WILL EXTEND WEST TO EAST ACROSS CANADA WITH FAIRLY ZONAL FLOW ACROSS THE NRN CONUS. THIS WILL BRING A THERMAL RIDGE EASTWARD INTO THE PLAINS AS H85 TEMPS IN WRN NEBR REACH 25 TO 30C. HIGHS WERE NUDGED UPWARD TO NEAR 90 WEST. FOR MONDAY THROUGH THURSDAY...ABOVE NORMAL TEMPERATURES. UPPER FLOW WILL BECOME SOUTHWESTERLY ALOFT MONDAY AND TUESDAY AS AN UPPER TROUGH DIGS INTO THE NWRN CONUS. THIS WILL ACT TO EXPAND THE THERMAL RIDGE EASTWARD ACROSS THE CENTRAL PLAINS. HIGHS AGAIN NUDGED UPWARD TO THE UPPER 8OS TO AROUND 90 MOST AREAS THESE HIGHS WILL BE 10 TO 15 DEGREES ABOVE NORMAL. A COLD FRONT TUESDAY NIGHT TO BRING A SLIGHT CHC FOR SHOWERS AND THUNDERSTORMS. EXTENDED PROCEDURE KEEPS WEDNESDAY DRY EXCEPT A SLIGHT CHANCE IN THE NORTHEASTERN AREAS. FUTURE MODEL RUNS MAY SHOW BETTER SUPPORT FOR WEDNESDAY AND WEDNESDAY NIGHT. BEHIND THE FRONT....HIGHS COOL BACK SOME TO THE UPPER 70S NORTH AND LOWER 80S NORTH FOR WEDNESDAY AND THURSDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 613 PM CDT THU SEP 10 2015 FOR THE KLBF TERMINAL...EXPECT SCATTERED TO BROKEN CIGS AON 20000 FT AGL THIS EVENING WITH A BROKEN DECK OF CLOUDS AON 10000 FT AGL DEVELOPING AFTER 08Z FRIDAY. THIS DECK OF CLOUDS IS EXPECTED TO REMAIN IN PLACE INTO FRIDAY AFTERNOON. FOR THE KVTN TERMINAL...EXPECT SCATTERED TO BROKEN CIGS AON 10000 FT AGL OVER THE NEXT 24 HRS. FOR BOTH TERMINALS...NORTHEASTERLY WINDS OF AROUND 10 KTS WILL BECOME VARIABLE AT UNDER 10 KTS OVERNIGHT...AND WILL PERSIST THROUGH FRIDAY AFTERNOON. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CLB SHORT TERM...JACOBS LONG TERM...ROBERG AVIATION...CLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
302 PM CDT WED SEP 9 2015 .SYNOPSIS... ISSUED AT 302 PM CDT WED SEP 9 2015 AS OF WEDNESDAY AFTERNOON THE UPPER AIR SYNOPTIC PATTERN OVER THE CONTINUED TO BE HIGHLIGHTED BY A BROAD TROUGH ASSOCIATED WITH A LOW SLOWLY MOVING TOWARD HUDSON BAY. THIS HAS THE NORTHERN AND CENTRAL PLAINS IN RELATIVELY FAST NORTHWEST FLOW ALOFT. COOLER AIR IN THE MID TO UPPER LEVEL OF THIS FLOW FOSTERED AN ENVIRONMENT CHARACTERIZED BY STEEP LAPSE RATES AND ELEVATED INSTABILITY...WHICH HAS AIDED IN THE FORMATION AND PERSISTENCE OF ISOLATED TO SCATTERED THUNDERSTORM ACTIVITY IN CENTRAL NEBRASKA LATE IN THE MORNING AND EARLY THIS AFTERNOON. AT THE SURFACE...A WEAK FRONT WAS SLOWLY MOVING EAST ACROSS THE CWA. AS OF 20Z THE FRONT EXTENDED FROM JUST EAST OF IMPERIAL AND NORTH PLATTE...NORTHEASTWARD TO NEAR AINSWORTH. DRY WESTERLY WINDS BEHIND THE FRONT HAD DEWPOINTS DROPPING INTO THE 30S AND 40S ACROSS THE PANHANDLE AND WESTERN SANDHILLS. AHEAD OF THE FRONT WINDS WERE SOUTHERLY AND DEWPOINTS REMAINED IN THE UPPER 50S AND 60S...WITH A CU FIELD DEVELOPING AS THE BOUNDARY LAYER BECOMES MORE UNSTABLE. TEMPERATURES WERE GENERALLY IN THE MID 80S. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 302 PM CDT WED SEP 9 2015 THUNDERSTORMS IN CENTRAL AND NORTH CENTRAL NEBRASKA SHOULD CONTINUE TO SLOWLY PUSH EAST THROUGH THE REMAINDER AFTERNOON. CONVECTIVE ACTIVITY HAS ACCELERATED OVER CENTRAL ROCK AND HOLT COUNTY. SOME LOCATIONS ARE RECEIVING HEAVY RAINFALL DUE TO TRAINING STORMS...HOWEVER LATEST FFG IN THIS AREA IS QUITE HIGH. ADDITIONAL SURFACE BASED SHOWERS AND THUNDERSTORM DEVELOPMENT HAS BEGUN IN FAR SOUTHWEST NEBRASKA AND NORTHWEST KANSAS ALONG AN EASTWARD PROGRESSING FRONT. HRRR HAS FAVORED AREAS JUST EAST OF A NORTH PLATTE TO THEDFORD MUCH OF THE DAY...AND THIS MATCHES UP WELL WITH THE DEVELOPING CU FIELD ON SATELLITE SO THE FORECAST LOOKS ON TRACK. UPPER LEVEL FORCING IS TOUGH TO DISCERN SO THE SPATIAL EXTENT OF THE NEW CONVECTION IS NOT EXPECTED TO BE EXPANSIVE. MLCAPE VALUES 1500 J/KG AND 35-40 KTS DEEP LAYER SHEAR WILL SUPPORT A FEW STRONG TO SEVERE STORMS...HOWEVER WIDESPREAD SEVERE WEATHER IS NOT EXPECTED. THUNDERSTORMS PUSH EAST THIS EVENING AND BEGIN TO WANE AFTER DARK WITH THE LOSS OF HEATING AND INSTABILITY. WEAK SHORTWAVE TROUGH DIVES SOUTHEAST THROUGH THE AREA OVERNIGHT. WINDS BECOME EASTERLY AS THE FRONT SLOWLY PUSHES JUST SOUTHEAST OF THE CWA AND A LEE SIDE SURFACE LOW DEEPENS IN NORTHEAST COLORADO. THIS WILL ALLOW LOW LEVEL MOISTURE TO CREEP BACK WESTWARD...WITH ANOTHER ROUND OF FOG/STRATUS POSSIBLE FOR SOUTHWEST INTO CENTRAL NEBRASKA. DID NOT INCLUDE PATCHY FOG IN THE FORECAST AT THIS TIME SINCE MODEL GUIDANCE HAS BEEN SOMEWHAT INCONSISTENT WITH COVERAGE AND SEVERITY OF VISIBILITY RESTRICTIONS. THE MOST FAVORABLE AREAS FOR LOCALLY DENSE FOG FORMATION WILL LIKELY BE WHERE PRECIPITATION FALLS LATER THIS EVENING. AN AREA OF SURFACE HIGH PRESSURE BEGINS TO DROP OUT OF ALBERTA AND INTO THE NORTHERN PLAINS ON THURSDAY. THIS WILL PUSH TEMPERATURES DOWN A FEW DEGREES WITH HIGHS RANGING FROM THE LOW 70S TO LOW 80S ACROSS THE CWA. MODELS ADVERTISE LIGHT QPF LATE IN THE AFTERNOON AS A MID-LEVEL JET STREAK NOSES INTO THE CENTRAL PLAINS...BUT DID NOT ADD ANY MENTION OF POPS TO THE SHORT TERM FORECAST JUST YET AS THE BETTER CHANCES LOOK TO BE AFTER 00Z FRIDAY. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 302 PM CDT WED SEP 9 2015 THE NAM REMAINS IN AGREEMENT WITH CURRENT FORECAST WITH A DISTURBANCE DROPPING SOUTHEAST FROM SWRN SD INTO WRN NEBR OVERNIGHT. THE GFS IS FASTER WITH THIS DISTURBANCE AND REMAINS MOSTLY DRY. THEREFORE KEPT POPS LIMITED TO 20 PERCENT WEST OF A LINE FROM GORDON THROUGH BROKEN BOW. KEPT VERY NEAR PREVIOUS HIGHS FRIDAY AS EASTERLY WINDS BECOME SOUTHEAST BY AFTERNOON AND WEAK WAA WILL NOT KICK IN UNTIL AFTERNOON. THERE COULD ALSO BE A FEW SHOWERS AND CLOUDINESS LINGERING AS WELL. ON SATURDAY...A RETURN SOUTHERLY WIND RETURNS WITH HIGHS WARMING TO NEAR 80 ACROSS THE WEST WHILE THE EAST REMAINS IN THE LOWER TO MID 70S. FOR SUNDAY THROUGH TUESDAY...ABOVE NORMAL TEMPERATURES. ZONAL FLOW ALOFT ACROSS THE CENTRAL PLAINS SUNDAY WILL PERSIST INTO MONDAY AS AN UPPER TROUGH DIGS INTO THE PACIFIC NORTHWEST. THIS WILL KEEP A THERMAL RIDGE ACROSS THE REGION WITH HIGHS RANGING IN THE 80S. ON TUESDAY...THE UPPER TROUGH WILL ADVANCE ACROSS MONTANA THROUGH COLORADO WITH STRONG HEATING TO OCCUR IN ADVANCE ACROSS THE CENTRAL PLAINS. FORECAST HIGH ARE 85 TO 90...ALTHOUGH THE POTENTIAL IS THERE FOR HIGHS TO EXCEED 90 IN SOME AREAS OF WRN NEBR. A COLD FRONT TUESDAY NIGHT TO COOL BACK HIGHS TO NEAR 75 NORTH AND NEAR 80 SOUTH. THE 12Z ECMWF HOWEVER IS MUCH WEAKER WITH THE POST FRONTAL COOLDOWN AND SUGGESTS 80S STILL POSSIBLE. MAINLY DRY THROUGH THE EXTENDED PERIODS...EXCEPT A SLIGHT CHANCE ERN PNHDL TUESDAY AFTN...AND MOST AREAS TUESDAY NIGHT. LOOKS DRY BEHIND THE FRONT FOR WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1223 PM CDT WED SEP 9 2015 MAIN CONCERNS FOR THE CURRENT TAF PERIOD IS THE ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING...AND THE POTENTIAL FOR SUB-VFR CIGS/VISBYS LATE TONIGHT AND EARLY THURSDAY MORNING. A LINE OF THUNDERSTORMS ARE ONGOING EARLY THIS AFTERNOON IN PARTS OF CENTRAL NEBRASKA...WITH REDEVELOPMENT TO THE WEST AND NORTH POSSIBLE LATER THIS AFTERNOON AND EVENING. DID NOT FEEL CONFIDENT ENOUGH IN THE SPATIAL EXTENT OF THUNDERSTORM ACTIVITY TO INCLUDE IN THE TAF AT KLBF. ALL MODEL GUIDANCE AND OBSERVATIONAL TRENDS SUGGEST THE ACTIVITY SHOULD REMAIN SOUTH AND EAST OF KVTN. FOG AND LOW STRATUS MAY DEVELOP OVERNIGHT...GENERALLY FROM SOUTHWEST INTO NORTH CENTRAL NEBRASKA...INCLUDING KLBF...KBBW...KONL. INTRODUCED MVFR CIGS/VISBYS INTO THE TAF TO SUGGEST THE POTENTIAL...ALTHOUGH THEY MAY NEED TO BE LOWERED INTO IFR SHOULD FORECASTER CONFIDENCE INCREASE. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MARTIN SHORT TERM...MARTIN LONG TERM...ROBERG AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
310 PM MDT WED SEP 9 2015 .SYNOPSIS... SCATTERED THUNDERSTORMS OVER CENTRAL NEW MEXICO WILL TAPER OFF THIS EVENING. THE COVERAGE OF STORMS WILL FOCUS OVER SOUTHWEST NEW MEXICO ON THURSDAY. DRIER AIR SETTLING INTO NORTHERN NEW MEXICO TONIGHT AND THURSDAY NIGHT WILL ALLOW LOW TEMPERATURES TO SETTLE INTO THE 30S AND 40S. A BACK DOOR COLD FRONT WILL SHIFT DOWN THE EASTERN PLAINS ON FRIDAY ALLOWING FOR ANOTHER UPTICK IN STORMS. HIGH TEMPERATURES WILL FALL BELOW NORMAL WITH MANY AREAS STAYING IN THE 70S. ISOLATED STORMS ARE EXPECTED OVER THE WEEKEND BEFORE THE NEXT INCREASE IN COVERAGE DEVELOPS MONDAY AND TUESDAY. && .DISCUSSION... THE COMBINATION OF A 40-50KT 300MB JET CORE AND MOIST UNSTABLE UPSLOPE FLOW ALONG THE EAST SLOPES OF THE CENTRAL MT CHAIN TODAY HAS LED TO A FEW STRONG TO LOCALLY SEVERE STORMS. SPC SSEO PICKED UP ON THE COVERAGE AREA VERY WELL. HRRR AND LOCAL WRF SHOW THIS ACTIVITY TAPERING OFF DURING THE EVENING WHILE DRYING TAKES PLACE FROM NORTH TO SOUTH. SFC DEWPOINTS FROM THE NAM12 SHOW UPPER 20S/ LOW 30S TONIGHT ACROSS THE NW HALF OF THE STATE...WHICH COMBINED WITH RADIATIONAL COOLING WILL LEAD TO CHILLY TEMPS. ANGEL FIRE IS EXPECTED TO HIT FREEZING FOR THE 1ST TIME SINCE AUGUST 5TH. THE AXIS FOR MOIST INSTABILITY WILL SHIFT FARTHER SOUTH THURSDAY INTO SW NM WHILE DRY AIR ALOFT CONTINUES PRESSING S/SE OVER NORTHERN NM. A FEW STORMS ARE STILL LIKELY AS WEAKLY FAVORABLE UPPER LEVEL JET DYNAMICS DRIFT SOUTH OUT OF COLORADO. AT THE SURFACE THE FIRST SIGNS OF A BACK DOOR FRONT WILL FLIRT WITH THE FAR NE PLAINS THUS PROVIDING YET ANOTHER FORCING MECHANISM WITHIN COLFAX AND UNION COUNTIES. THIS FRONT WILL SURGE INTO EASTERN NM AND THRU GAPS IN THE CENTRAL MT CHAIN FRIDAY. MEANWHILE A 590DM H5 HIGH CENTER WILL BECOME POSITIONED OVERHEAD AND FOCUS MORE TERRAIN DOMINATED STORM COVERAGE FRIDAY THROUGH THE WEEKEND. EXTENDED MODEL GUIDANCE IS GOING TO HAVE A DIFFICULT TIME WITH THE REMNANTS OF HURRICANE LINDA NEXT WEEK AS SEVERAL DISORGANIZED UPPER LEVEL VORT FEATURES TAKE SHAPE ALONG THE WEST COAST. FOR NOW IT APPEARS MONDAY/TUESDAY COULD FEATURE AN UPTICK IN STORM COVERAGE AS A PORTION OF THE 700-500MB MOISTURE AXIS CROSSES NM. GUYER && .FIRE WEATHER... A NEW CENTROID OF HIGH PRESSURE HAS TAKEN SHAPE OVER THE GREAT BASIN. THIS WILL FUNNEL DRIER AIR OVER NM FROM THE NORTHWEST WITH MINIMUM HUMIDITIES FALLING A FEW TO 14 DEGREES ACROSS THE FORECAST AREA THURSDAY. SINCE LOW LEVEL FLOW WILL ALSO TAKE ON MORE OF A SOUTHWESTERLY COMPONENT ON THURSDAY...THERE WILL BE A DOWNTICK IN SHOWER AND THUNDERSTORM COVERAGE WITH MAINLY ISOLATED ACTIVITY FAVORING LOCATIONS ALONG AND EAST OF THE CONTINENTAL DIVIDE. A STRONGER BACK DOOR COLD FRONT FRIDAY WILL BRING WITH IT MORE MOISTURE WITH AN UPTICK IN SHOWER AND THUNDERSTORM ACTIVITY ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN DURING THE AFTERNOON...THEN AS FAR WEST AS THE CONTINENTAL DIVIDE DURING THE EVENING. THIS FRONT IS FORECAST TO PRODUCE A MODERATELY GUSTY EAST CANYON WIND IN THE MIDDLE AND LOWER RIO GRANDE VALLEY FRIDAY AND FRIDAY NIGHT. ANOTHER CROP OF THUNDERSTORMS IS EXPECTED ALONG AND EAST OF THE CONTINENTAL DIVIDE ON SATURDAY AS MOISTURE RECYCLES...BUT THERE WILL BE A DOWNTICK IN COVERAGE. THE UPPER HIGH IS FORECAST TO MIGRATE SOUTHEASTWARD TO AROUND THE NM BOOT HEEL ON SUNDAY...THEN TO THE SE OF NM ON MONDAY AS AN UPPER LEVEL TROUGH DEEPENS INTO A LOW PRESSURE SYSTEM ON THE WEST COAST AND EJECTS SOME OF ITS SHORTWAVE ENERGY INLAND ACROSS THE CENTRAL ROCKIES. THERE ARE SIGNIFICANT DISAGREEMENTS BETWEEN MODELS ON THE TRACK AND TIMING OF THIS LOW AND THE SHORTWAVES...BUT THE GFS AND ECMWF DO AGREE FAIRLY WELL ON A TAP OF SUBTROPICAL MOISTURE IN STRENGTHENING SW FLOW ALOFT REACHING SW AREAS SUNDAY AND MUCH OF CENTRAL AND WESTERN NM MONDAY. A ROLLER COASTER OF TEMPERATURES IS EXPECTED THROUGH THE WEEKEND. HIGH TEMPERATURES WILL WARM A FEW TO 5 DEGREES THURSDAY...THEN FALL WITH THE BACK DOOR COLD FRONT FRIDAY. FALLING TEMPERATURES WILL CONTINUE IN THE WEST THROUGH SATURDAY...WHILE EASTERN READINGS BEGIN TO REBOUND. HIGH TEMPS SHOULD THEN WARM SUNDAY AS THE CENTER OF HIGH PRESSURE DRAWS NEAR...THEN BEGIN TO FALL IN THE WEST AGAIN MONDAY AS BETTER MOISTURE ARRIVES. MINIMUM HUMIDITIES SHOULD FALL A FEW TO 22 PERCENT ON SUNDAY BEFORE BEGINNING TO REBOUND IN THE WEST ON MONDAY. HIGH HAINES VALUES IN THE 5 TO 6 RANGE ARE EXPECTED OVER NORTHWEST AND NORTH CENTRAL AREAS THURSDAY...THEN OVER NW AND WEST CENTRAL AREAS FRIDAY. EXTREME VALUES SHOULD ABATE EAST OF THE CONTINENTAL DIVIDE WITH THE ARRIVAL OF BETTER MOISTURE ON FRIDAY NIGHT AND SATURDAY...ONLY TO OVERSPREAD MOST LOCATIONS ALONG AND NORTH OF INTERSTATE 40 ON SUNDAY. NORTHEAST AREAS MAY CONTINUE TO BE AFFLICTED WITH HIGH HAINES ON MONDAY. POCKETS OF POOR VENTILATION WILL IMPACT WEST CENTRAL AREAS WEDNESDAY...THEN NORTH CENTRAL...CENTRAL AND SOUTHWEST AREAS THURSDAY. POCKETS OF POOR VENTILATION MAY LINGER INTO FRIDAY WEST OF THE CONTINENTAL DIVIDE AND OVER THE SANGRE DE CRISTOS...BUT VENTILATION LOOKS TO IMPROVE MOST PLACES SATURDAY AND ESPECIALLY SUNDAY. RATES SHOULD THEN STAY GOOD TO EXCELLENT MONDAY. 44 && .AVIATION... 18Z TAF CYCLE TRUSTED MESOSCALE MODELS DEPICT SLOW MOVING -SHRA/-TS FAVORING THE CENTRAL MT CHAIN AND ADJACENT E SLOPES...AS WELL AS NEW MEXICOS SOUTHERN HIGH TERRAIN TODAY. MOST OF THE ACTIVITY WILL DRIFT TO THE SE AROUND 5 TO 15 MPH...WHICH SHOULD EVENTUALLY TRACK CELLS NEAR KTCC AND KROW. MODELS ALSO SUGGEST A FEW CELLS WILL POP UP NEAR KSAF...KABQ...KAEG AND KGUP...THOUGH TS PROBABILITIES WERE LOW ENOUGH TO USE VCSH RATHER THAN VCTS IN THESE TAFS. A FEW ISOLD CELLS COULD LINGER INTO THE LATE NIGHT HOURS MAINLY ALONG AND S OF HWY 60. A MIXTURE OF WET AND DRY MICROBURSTS ARE EXPECTED TODAY WITH LOCALIZED AND ERRATIC WIND GUSTS NEAR 45 KT. 44 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 52 90 52 89 / 0 0 0 5 DULCE........................... 36 83 37 82 / 10 10 5 5 CUBA............................ 46 81 46 78 / 10 5 5 5 GALLUP.......................... 46 87 46 87 / 5 5 0 5 EL MORRO........................ 43 81 43 80 / 10 10 5 10 GRANTS.......................... 45 86 44 83 / 10 10 5 5 QUEMADO......................... 53 80 50 82 / 20 20 20 20 GLENWOOD........................ 56 77 54 83 / 30 30 30 20 CHAMA........................... 42 76 43 75 / 10 10 10 10 LOS ALAMOS...................... 58 81 58 79 / 10 10 5 10 PECOS........................... 55 78 54 73 / 20 10 10 30 CERRO/QUESTA.................... 51 78 50 75 / 20 20 10 30 RED RIVER....................... 38 72 39 66 / 20 20 10 40 ANGEL FIRE...................... 49 68 50 62 / 20 30 20 40 TAOS............................ 44 82 42 78 / 20 10 10 10 MORA............................ 50 75 51 68 / 30 30 20 30 ESPANOLA........................ 50 87 50 85 / 10 5 5 10 SANTA FE........................ 58 81 58 77 / 10 10 5 10 SANTA FE AIRPORT................ 54 87 55 83 / 10 10 5 10 ALBUQUERQUE FOOTHILLS........... 61 87 59 83 / 10 5 5 5 ALBUQUERQUE HEIGHTS............. 64 90 62 86 / 10 5 5 5 ALBUQUERQUE VALLEY.............. 59 91 58 88 / 10 5 0 5 ALBUQUERQUE WEST MESA........... 63 92 60 88 / 10 0 0 5 LOS LUNAS....................... 56 91 56 89 / 10 5 5 5 RIO RANCHO...................... 61 91 59 87 / 10 0 0 5 SOCORRO......................... 62 90 59 89 / 30 20 10 20 SANDIA PARK/CEDAR CREST......... 55 84 55 79 / 20 10 10 30 TIJERAS......................... 58 86 55 81 / 20 5 5 10 MORIARTY/ESTANCIA............... 49 85 49 81 / 20 10 10 30 CLINES CORNERS.................. 55 82 55 74 / 30 10 10 30 GRAN QUIVIRA.................... 58 81 55 78 / 40 20 20 30 CARRIZOZO....................... 62 84 59 83 / 40 30 20 20 RUIDOSO......................... 57 76 55 75 / 50 50 40 40 CAPULIN......................... 54 80 53 64 / 10 20 30 30 RATON........................... 49 87 51 74 / 10 20 20 30 SPRINGER........................ 51 86 52 74 / 10 10 20 30 LAS VEGAS....................... 50 83 49 74 / 30 30 20 30 CLAYTON......................... 59 88 58 70 / 10 10 30 30 ROY............................. 57 85 52 70 / 10 10 20 30 CONCHAS......................... 64 92 62 80 / 10 10 20 30 SANTA ROSA...................... 62 90 61 81 / 20 10 10 30 TUCUMCARI....................... 64 93 61 77 / 10 10 20 30 CLOVIS.......................... 63 89 61 80 / 20 10 10 30 PORTALES........................ 66 88 63 82 / 20 10 10 30 FORT SUMNER..................... 64 89 62 80 / 20 10 10 30 ROSWELL......................... 68 93 65 91 / 30 10 10 30 PICACHO......................... 62 86 60 83 / 30 20 20 30 ELK............................. 61 76 58 76 / 40 30 30 30 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1038 PM EDT THU SEP 10 2015 .SYNOPSIS... LATE SUMMER HEAT AND HUMIDITY ALONG WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL PREVAIL THROUGH SATURDAY...AHEAD OF AN APPROACHING BUT STALLING COLD FRONT. A SECONDARY AND STRONGER COLD FRONT WILL SWEEP OFF THE COAST LATE SUNDAY...USHERING DRIER AND COOLER EARLY AUTUMN AIR ACROSS THE CAROLINAS THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 1000 PM THURSDAY...A MESO-LOW WAS DETECTABLE ACROSS THE EASTERN CAROLINAS LATE THIS EVE. A SURFACE COLD FRONT WAS APPROACHING FROM THE NW. A LARGE CLUSTER OF SHOWERS AND THUNDERSTORMS THAT MOVED INTO THE SOUTHERN REACHES OF THE FORECAST AREA EARLIER HAS BECOME A LARGE AREA OF STRATIFORM RAIN ACROSS A GOOD PORTION OF SOUTH CAROLINA. HOWEVER...STRONG THUNDERSTORMS PERSIST ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA...AROUND BENNETTSVILLE AND DARLINGTON TO DILLON AND THEN ACROSS ROBESON AND BLADEN COUNTIES. THE DEVELOPING MESO-LOW SHOULD ALLOW THESE SHOWERS AND THUNDERSTORMS TO PERSIST FOR SEVERAL MORE HOURS AND WE ARE NOW FORECASTING CONVECTION/HIGH POPS ALL THE WAY TO THE CAPE FEAR COAST OVERNIGHT. THE CLOUD TOPS HAVE BEGUN TO SLOWLY WARM AND WITH THAT AND THE INTENSITY OF THE THUNDERSTORMS HAS DIMINISHED FROM EARLIER IN THE EVE. THE NUMBER OF LIGHTNING STRIKES...WHICH HAD BEEN PROLIFIC...IS ALSO ON THE WANE. STILL...A STRONG THUNDERSTORM IS POSSIBLE ACROSS THE NORTHERN THIRD OR SO OF THE FORECAST AREA THROUGH THE LATE EVE. IT IS HERE THAT I WILL CONTINUE TO HIGHLIGHT THE RISK FOR FREQUENT LIGHTNING...HEAVY DOWNPOURS AND GUSTY WINDS. OVERNIGHT...AS THE ATMOSPHERE CONTINUES TO STABILIZE...THUNDERSTORMS WILL BECOME FEWER AND FEWER. AFTER 08-09Z...EXPECT MOST OF THE CONVECTION WILL BE OFFSHORE. CONDITIONS ARE NOT IDEAL FOR FOG. HOWEVER...AS THE LOW-LEVEL JET WEAKENS LATE AND THE THICKER CLOUD COVER THINS INLAND...THERE WILL BE AN OPPORTUNITY FOR STRATUS/FOG TO DEVELOP NEAR DAYBREAK GIVEN THE HEAVY RAIN THAT HAS AND IN SOME AREAS IS STILL FALLING. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...UNSEASONABLY WARM AND HUMID CONDITIONS ALONG WITH UNSETTLED WEATHER WILL CONTINUE IN ADVANCE OF THE NEXT COLD FRONT...WHICH WILL BE POISED TO MOVE OFFSHORE BY DAYBREAK ON SUNDAY MORNING. COLD FRONT WILL BE THE STRONGEST OF THE SEASON SO FAR...AND ITS ASSOCIATED UPPER TROUGH WILL LIKEWISE BE ON THE DEEP AND SHARP SIDE. DYNAMICS WILL BE IN PLAY FOR AT LEAST SCATTERED CONVECTION BOTH DAYS. GUIDANCE IS NOT IN REAL GOOD AGREEMENT REGARDING TIMING OF CONVECTION AND MUCH WILL DEPEND UPON THE STRENGTH AND PLACEMENT OF A SERIES OF UPPER DISTURBANCES THAT WILL ROUND THE BASE OF THE UPPER TROUGH. BEST GUESS BASED ON A CONSENSUS OF GUIDANCE WILL BE THAT SATURDAY WILL BE THE MOST ACTIVE OF THE TWO DAYS. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 300 PM THURSDAY...STRONG COLD FRONT WILL BE CROSSING OFFSHORE SUNDAY MORNING...AND RESIDUAL CONVECTION MAY STILL BE ONGOING ACROSS COASTAL SECTIONS OF THE CWA THE BEGINNING OF SUNDAY. THEREAFTER HOWEVER...A BEAUTIFUL LATE-SUMMER STRETCH OF WEATHER IS ANTICIPATED AS COOL CANADIAN HIGH PRESSURE EXPANDS ACROSS THE EAST. STRONG UPPER LOW WILL BE ROTATING OVERHEAD SUNDAY MORNING...AND WILL PASS OFFSHORE BY THE AFTN. SHOWERS AND TSTMS WILL BE RAPIDLY EXITING THE AREA SUNDAY AS THE FIRST TRUE AUTUMN COLD FRONT AND AIRMASS ADVECT INTO AND ACROSS THE CAROLINAS. BY MONDAY...850MB TEMPS DROP TO AROUND 10C AND PWATS FALL TO AROUND 1/2 INCH...BOTH SIGNALS TO THE COOLNESS/DRYNESS OF THE UPCOMING AIRMASS. WHILE SUNDAY WILL FEATURE NEAR NORMAL TEMPERATURES...THE MON-WED TIMEFRAME WILL BE ABOUT PERFECT WITH HIGHS AROUND 80 AND LOWS DIPPING INTO THE UPPER 50S BENEATH ABUNDANT SUNSHINE. THE UPPER RIDGE WILL BEGIN TO BREAK DOWN THURSDAY BUT ANOTHER BEAUTIFUL DAY IS EXPECTED...ALTHOUGH CLOUD COVER MAY BEGIN TO INCREASE. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AS OF 00Z...TIGHT GRADIENT CONTINUES FROM THE SOUTHWEST OUT AHEAD OF AN APPROACHING TROUGH/FRONT. WINDS CONTINUE TO GUST TO OVER 20 KT ALONG THE NC/SC COASTAL TERMINALS BUT HAVE STARTED TO ABATE INLAND. HRRR HAS A PRETTY GOOD HANDLE ON PRECIPITATION ACROSS THE REGION ALTHOUGH A LITTLE OVERDONE NEAR THE COAST AND MODEL STARTS TO DISSIPATE PRECIP AS THE NIGHT GOES ON. WILL BACK OFF OF POPS ALONG THE COASTAL TERMINALS AS WELL AS KLBT...RIGHT NOW KFLO LOOKS LIKE THE BEST TERMINAL FOR POPS OVER THE NEXT FEW HOURS. GFS IS MODEL OF CHOICE OVER NAMS AND WILL SCALE DONE THE POPS FOR THE REMAINDER OF THE NIGHT AND INTO TOMORROW MORNING AND EARLY AFTERNOON. WINDS SHIFT TAKES PLACE FROM INLAND TO THE COAST WITH INLAND TERMINALS DURING THE MID MORNING AND COASTAL TERMINALS BY EARLY AFTERNOON. LOOK FOR A MODERATE DEGREE OF CONFIDENCE TO STAY VFR ACROSS THE TERMINALS ON FRIDAY WITH A LOW TO MODERATE CHANCE ACROSS THE INLAND TERMINALS FOR THE EARLY MORNING PERIOD. EXTENDED OUTLOOK...SCATTERED STORMS FRIDAY AFTERNOON...MORE NUMEROUS ON SATURDAY. SHOWERS ENDING SUNDAY MORNING WITH COOLER AND DRIER CONDITIONS THROUGH TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 PM THURSDAY...A SMALL CRAFT SHOULD EXERCISE CAUTION HEADLINE IS IN EFFECT THROUGH THE OVERNIGHT. IT CONTINUES TO BE BREEZY ACROSS THE WATERS WITH SUSTAINED WIND SPEEDS AROUND 20 KT WITH GUSTS UP TO 25 KT. THESE WINDS ARE EXPECTED TO CONTINUE TONIGHT WITH LOW-LEVEL JETTING ON THE ORDER OF 25 KT WELL INTO THE NIGHT. SEAS WILL BE 4 TO 5 FT...WITH 6 FT SEAS POSSIBLE JUST BEYOND 20 NM. CONVECTION ACROSS THE SOUTHERN WATERS WILL BE WANING WHILE CONVECTION ACROSS THE NORTHERN WATERS INCREASES OVERNIGHT. WINDS AND SEAS MAY BE HIGHER IN THUNDERSTORMS. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...SWLY WINDS WILL GENERALLY INCREASE OVER THE WATERS IN ADVANCE OF A STRONG COLD FRONT. ON FRIDAY WINDS WILL LIKELY BE IN THE 10 TO 15 KT RANGE...INCREASING TO 15 TO 20 KT ON SATURDAY. WINDS WILL SLACKEN IN THE EARLY MORNING HOURS OF SUNDAY AS THE FRONT APPROACHES THE WATERS. SEAS WILL LIKEWISE GRADUALLY BUILD THROUGH THE PERIOD...SUBSIDING A BIT TOWARDS DAYBREAK ON SUNDAY MORNING. AT THIS POINT IT DOES NOT LOOK LIKE SEAS WILL BUILD HIGH ENOUGH TO NEED AND ADVISORY PRODUCTS. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 PM THURSDAY...COLD FRONT WILL BE MOVING OFFSHORE SUNDAY MORNING...WITH WINDS VEERING FROM W/SW EARLY SUNDAY AT 10-15 KT...TO NW AT AROUND 10 KT SUNDAY NIGHT. LARGE CANADIAN HIGH PRESSURE WILL BUILD DOWN ACROSS THE AREA EARLY NEXT WEEK...CREATING A WEAK PRESSURE GRADIENT AND LIGHT N/NE WINDS MONDAY...INCREASING SLIGHTLY ON TUESDAY TO AROUND 10 KT AS THE RIDGING INTENSIFIES DOWN THE COAST. THE PERIOD WILL BE BOOKENDED BY 2-4 FT SEAS BOTH SUNDAY ON THE W/SW WINDS AND AGAIN LATE TUESDAY WITH THE INCREASING NE WINDS. OTHERWISE EXPECT JUST 1-2 FT BENEATH THE LIGHT GRADIENT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RJD SHORT TERM...REK LONG TERM...JDW AVIATION...MAC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
956 PM EDT THU SEP 10 2015 .SYNOPSIS... HIGH PRESSURE REMAINS WELL OFF THE SOUTHEAST COAST THROUGH FRIDAY. A WEAK TROF OF LOW PRESSURE WILL APPROACH FROM THE WEST TONIGHT THEN SLOWLY MOVE INTO THE AREA ON FRIDAY. AREA OF LOW PRESSURE WILL DEVELOP NORTHWEST OF THE REGION SATURDAY INTO SATURDAY NIGHT THEN PASS NORTH OF THE AREA SUNDAY. A COLD FRONT TRAILING THE LOW WILL CROSS THE AREA SUNDAY NIGHT FOLLOWED BY HIGH PRESSURE EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 950 PM THURSDAY...VERY MINIMAL CHANGES TO CURRENT FORECAST. ACTIVE CONVECTION CONTINUES ACROSS OUR FAR NORTHERN CWA WITH ADDITIONAL SHOWERS/THUNDERSTORMS APPROACHING FROM THE SOUTHWEST. WILL CONTINUE HIGH CHANCE POPS OVER THE COASTAL PLAINS TAPERING TO SLIGHT CHANCE TOWARD THE CRYSTAL COAST/OUTER BANKS REGION. AIRMASS IS STILL QUITE UNSTABLE...ESPECIALLY NEAR THE COAST BUT WOULD EXPECT THE STORMS TO GRADUALLY DIMINISH OVER THE NEXT HOUR OR TWO. THE 3KM HRRR SHOWS ALOT OF THE CONVECTION TO THE SOUTHWEST DIMINISH AS IT MOVES INTO COASTAL SECTIONS AFTER MIDNIGHT. ANOTHER WARM/MUGGY NIGHT WITH LOWS RANGING FROM LOW 70S DEEP INLAND TO UPPER 70S BEACHES. REMNANT CONVECTIVE CLOUD DEBRIS/INCREASING CLOUDINESS OVERNIGHT SHUD DETER WIDESPREAD FOG FORMATION ALTHO SOME PATCHY FOG ESPECIALLY WHERE ANY PRECIP HAS FALLEN WILL BE POSSIBLE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... AS OF 320 PM THU...SFC TROF SLOWLY PUSHES INTO THE FORECAST AREA FRIDAY AND MAY HELP FOCUS INCREASING PRECIP CHANCES DURING DIURNAL CYCLE AIDED BY APPROACH OF WEAK MID LEVEL TROF DURING THE AFTERNOON. WILL CAP POPS AT GOOD CHANCE FOR NOW GIVEN THE GENERALLY WEAK FORCING MECHANISMS BUT PRECIP CHANCES MAY NEED TO BE RAISED IF LATER MODELS RUNS SUPPORT A WETTER SCENARIO. INSTABILITY WILL BE LACKING FRIDAY SO NOT EXPECTING MUCH OF SEVERE THREAT. NOT AS WARM TOMORROW AS CLOUDS WILL HELP HOLD TEMPS IN THE MID AND UPPER 80S BUT WITH DEW POINTS REMAINING IN THE 70S, HEAT INDICES WILL REACH INTO THE LOW 90S. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... AS OF 310 PM THU...UNSETTLED THIS WEEKEND AS STRONG FRONTAL SYSTEM IMPACTS THE REGION...THEN DRIER AND COOLER FOR NEXT WEEK. A STRONG COLD FRONT WILL APPROACH THE REGION FRI NIGHT AND SAT AS ASSOCIATED UPPER LEVEL TROUGH DEEPENS TO THE WEST. SPC HAS ENC OUTLOOKED IN MARGINAL RISK FOR SVR TSTMS SAT. DEEP SW FLOW CONTINUES AHEAD OF THE FRONT WITH THE REGION IN THE WARM SECTOR. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH GOOD FORCING AND INCREASING SHEAR. AT THIS TIME THINK THE BEST CHANCE FOR STRONG/SEVERE STORMS WOULD BE LATE AFTERNOON AND EARLY EVENING...WITH THE MAIN THREATS DAMAGING WIND GUSTS AND LOCALLY HEAVY RAINFALL. LATEST 12Z GUIDANCE HAS SLOWED THE BOUNDARY AND ASSOCIATED PRECIP SLIGHTLY. THE LIMITING FACTOR CONTINUES TO BE INSTABILITY. THOUGH MORE INSTABILITY COULD BE REALIZED IF WE SEE SOME BREAKS IN THE CLOUDS. ADJUSTED POPS SLIGHTLY...THOUGH CONTINUED HIGH CHANCE INCREASING TO LIKELY SAT EVENING/NIGHT. UPPER LOW AND TROUGH STRENGTHEN TO THE NORTH SUNDAY AS TRAILING COLD FRONT PUSHES THROUGH THE AREA. GFS STILL SLIGHTLY FASTER THAN THE ECMWF WITH THE FRONTAL PASSAGE...BUT EXPECT FRONT TO MOVE THROUGH LATE SUN/SUN EVENING. DRIER AND COOLER AIR WILL BE GRADUALLY FILTERING INTO THE REGION WITH PRECIP TAPERING OFF FROM WEST TO EAST. HIGH PRESSURE WILL BUILD OVER THE AREA MONDAY AS UPPER TROUGH PUSHES OFF THE EAST COAST. HIGH WILL REMAIN ANCHORED OVER THE AREA THROUGH THURSDAY. VERY PLEASANT WEATHER EXPECTED WITH THE REGION SEEING THE FIRST GLIMPSE OF FALL...AS DEWPOINTS DROP INTO THE 50S. LOW LEVEL THICKNESS VALUES SUPPORT TEMPS A FEW DEGREES BELOW NORMAL...WITH HIGHS IN THE UPPER 70S/LOW 80S AND OVERNIGHT LOWS IN THE MID/UPPER 50S INLAND AND LOW/UPPER 60S ALONG THE COAST. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH 00Z SATURDAY/... AS OF 655 PM THURSDAY...SCATTERED THUNDERSTORMS MOVING OFF THE EASTERN PIEDMONT MAY IMPACT THE KPGV/KISO TAF SITES THROUGH LATE EVENING. LESSER CHANCES OF CONVECTION AT KEWN/KOAJ. THINK DEBRIS CLOUDINESS FROM THIS CONVECTION ACCOMPANIED BY WEAK LOW-LEVEL MIXING SHOULD PRECLUDE ANY WIDESPREAD FOG FORMATION OVERNIGHT...ALTHOUGH A FEW PATCHES OF DENSE FOG WILL BE POSSIBLE IN AREAS THAT RECEIVE RAINFALL. VFR CONDITIONS SHOULD PREVAIL THROUGH MID-AFTERNOON FRIDAY AS WILL LIKELY BE DELAYED INTO THE AFTERNOON. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 310 PM THU...PERIODS OF SUB-VFR WILL BE POSSIBLE FRI NIGHT THROUGH SUNDAY...WITH SCATTERED TO NUMEROUS SHOWER/TSTMS AHEAD OF A STRONG COLD FRONT. PRED VFR CONDITIONS SHOULD RETURN BY LATE SUNDAY AS A COLD FRONT PUSHES THROUGH THE TERMINALS. && .MARINE... SHORT TERM /THROUGH FRIDAY/... AS OF 955 PM THURSDAY...GUSTY S/SW WINDS CONTINUE OVER THE PAMLICO SOUND AND CENTRAL/SOUTHERN WATERS WITH THE GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND AN APPROACHING FRONTAL BOUNDARY. NO CHANGES TO THE SMALL CRAFT ADVISORIES IN EFFECT. THIS BOUNDARY PUSHES INTO THE MARINE AREA FRIDAY WITH WINDS SHIFTING NORTH AND BECOMING LIGHT OVER NORTHERN COASTAL WATERS, WHILE REMAINING SW AT MODERATE SPEEDS OVER SOUTHERN AREAS DURING THE AFTERNOON. LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 310 PM THU...A STRONG COLD FRONT WILL APPROACH THE WATERS FROM THE WEST FRIDAY NIGHT AND SATURDAY. PRESSURE GRADIENT WILL TIGHTEN WITH SWLY WINDS INCREASING TO 15-25KT AND SEAS BUILDING TO 4-6FT. PERIOD OF SCA CONDITIONS EXPECTED TO DEVELOP EARLY SAT EVENING AND CONTINUE INTO EARLY SUN MORNING...MAINLY SOUTH OF OREGON INLET. SW/WSW 10-20KT CONTINUES SUN WITH SEAS 2-5FT. THE FRONT WILL MOVE THROUGH THE WATERS LATE SUN/SUN EVENING...WITH HIGH PRESSURE BUILDING IN BEHIND THE FRONT. HIGH PRESSURE WILL REMAIN ANCHORED OVER THE AREA MONDAY AND TUESDAY. WINDS BECOMING N/NW LESS THAN 15KT FOR MON AND SEAS 2-4FT...AND 10KT OR LESS TUE WITH SEAS 1-3FT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT FRIDAY FOR AMZ135-152-154- 156-158. && $$ SYNOPSIS...BTC NEAR TERM...CTC SHORT TERM...BTC LONG TERM...CQD AVIATION...BTC/CTC/CQD MARINE...BTC/CTC/CQD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
745 PM EDT THU SEP 10 2015 .SYNOPSIS... LATE SUMMER HEAT AND HUMIDITY ALONG WITH SCATTERED SHOWERS AND THUNDERSTORMS WILL PREVAIL THROUGH SATURDAY...AHEAD OF AN APPROACHING BUT STALLING COLD FRONT. A SECONDARY AND STRONGER COLD FRONT WILL SWEEP OFF THE COAST LATE SUNDAY...USHERING DRIER AND COOLER EARLY AUTUMN AIR ACROSS THE CAROLINAS THROUGH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... AS OF 700 PM THURSDAY...A LARGE CLUSTER OF STRONG THUNDERSTORMS WILL BE MOVING INTO THE PEE DEE REGION OF SOUTH CAROLINA THIS EVE. FREQUENT CLOUD TO GROUND LIGHTING...TORRENTIAL RAINFALL AND STRONG GUSTY WINDS ARE EXPECTED. AN ISOLATED DAMAGING WIND GUST IS POSSIBLE. HAVE INCREASED POPS TO CATEGORICAL ALONG AND W OF A LINE FROM NEAR GGE TO MAO TO LBT. AS THESE THUNDERSTORMS MOVE FURTHER E...THEY WILL BEGIN TO DIMINISH BOTH IN INTENSITY AND COVERAGE. WILL THEREFORE TREND POPS DOWNWARD AND TO JUST A CHANCE ALONG THE MORE IMMEDIATE COAST OVERNIGHT. OVERNIGHT...AS THE ATMOSPHERE STABILIZES...THUNDERSTORMS WILL BECOME FEWER AND FEWER. THE HIGH RESOLUTION MODELS ARE TRENDING TOWARD LITTLE OR NO SHOWER OR THUNDERSTORM ACTIVITY AFTER 06-07Z. GIVEN THE CURRENT ORGANIZATION...WILL BE A LITTLE MORE PESSIMISTIC...BUT DO EXPECT CONVECTION TO REDEVELOP ACROSS THE CLIMATOLOGICALLY FAVORED WARM OCEAN WATERS AS THE EARLY MORNING HOURS PROGRESS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...UNSEASONABLY WARM AND HUMID CONDITIONS ALONG WITH UNSETTLED WEATHER WILL CONTINUE IN ADVANCE OF THE NEXT COLD FRONT...WHICH WILL BE POISED TO MOVE OFFSHORE BY DAYBREAK ON SUNDAY MORNING. COLD FRONT WILL BE THE STRONGEST OF THE SEASON SO FAR...AND ITS ASSOCIATED UPPER TROUGH WILL LIKEWISE BE ON THE DEEP AND SHARP SIDE. DYNAMICS WILL BE IN PLAY FOR AT LEAST SCATTERED CONVECTION BOTH DAYS. GUIDANCE IS NOT IN REAL GOOD AGREEMENT REGARDING TIMING OF CONVECTION AND MUCH WILL DEPEND UPON THE STRENGTH AND PLACEMENT OF A SERIES OF UPPER DISTURBANCES THAT WILL ROUND THE BASE OF THE UPPER TROUGH. BEST GUESS BASED ON A CONSENSUS OF GUIDANCE WILL BE THAT SATURDAY WILL BE THE MOST ACTIVE OF THE TWO DAYS. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 300 PM THURSDAY...STRONG COLD FRONT WILL BE CROSSING OFFSHORE SUNDAY MORNING...AND RESIDUAL CONVECTION MAY STILL BE ONGOING ACROSS COASTAL SECTIONS OF THE CWA THE BEGINNING OF SUNDAY. THEREAFTER HOWEVER...A BEAUTIFUL LATE-SUMMER STRETCH OF WEATHER IS ANTICIPATED AS COOL CANADIAN HIGH PRESSURE EXPANDS ACROSS THE EAST. STRONG UPPER LOW WILL BE ROTATING OVERHEAD SUNDAY MORNING...AND WILL PASS OFFSHORE BY THE AFTN. SHOWERS AND TSTMS WILL BE RAPIDLY EXITING THE AREA SUNDAY AS THE FIRST TRUE AUTUMN COLD FRONT AND AIRMASS ADVECT INTO AND ACROSS THE CAROLINAS. BY MONDAY...850MB TEMPS DROP TO AROUND 10C AND PWATS FALL TO AROUND 1/2 INCH...BOTH SIGNALS TO THE COOLNESS/DRYNESS OF THE UPCOMING AIRMASS. WHILE SUNDAY WILL FEATURE NEAR NORMAL TEMPERATURES...THE MON-WED TIMEFRAME WILL BE ABOUT PERFECT WITH HIGHS AROUND 80 AND LOWS DIPPING INTO THE UPPER 50S BENEATH ABUNDANT SUNSHINE. THE UPPER RIDGE WILL BEGIN TO BREAK DOWN THURSDAY BUT ANOTHER BEAUTIFUL DAY IS EXPECTED...ALTHOUGH CLOUD COVER MAY BEGIN TO INCREASE. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AS OF 00Z...TIGHT GRADIENT CONTINUES FROM THE SOUTHWEST OUT AHEAD OF AN APPROACHING TROUGH/FRONT. WINDS CONTINUE TO GUST TO OVER 20 KT ALONG THE NC/SC COASTAL TERMINALS BUT HAVE STARTED TO ABATE INLAND. HRRR HAS A PRETTY GOOD HANDLE ON PRECIPITATION ACROSS THE REGION ALTHOUGH A LITTLE OVERDONE NEAR THE COAST AND MODEL STARTS TO DISSIPATE PRECIP AS THE NIGHT GOES ON. WILL BACK OFF OF POPS ALONG THE COASTAL TERMINALS AS WELL AS KLBT...RIGHT NOW KFLO LOOKS LIKE THE BEST TERMINAL FOR POPS OVER THE NEXT FEW HOURS. GFS IS MODEL OF CHOICE OVER NAMS AND WILL SCALE DONE THE POPS FOR THE REMAINDER OF THE NIGHT AND INTO TOMORROW MORNING AND EARLY AFTERNOON. WINDS SHIFT TAKES PLACE FROM INLAND TO THE COAST WITH INLAND TERMINALS DURING THE MID MORNING AND COASTAL TERMINALS BY EARLY AFTERNOON. LOOK FOR A MODERATE DEGREE OF CONFIDENCE TO STAY VFR ACROSS THE TERMINALS ON FRIDAY WITH A LOW TO MODERATE CHANCE ACROSS THE INLAND TERMINALS FOR THE EARLY MORNING PERIOD. EXTENDED OUTLOOK...SCATTERED STORMS FRIDAY AFTERNOON...MORE NUMEROUS ON SATURDAY. SHOWERS ENDING SUNDAY MORNING WITH COOLER AND DRIER CONDITIONS THROUGH TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 700 PM THURSDAY...HAVE RAISED A SMALL CRAFT SHOULD EXERCISE CAUTION HEADLINE FOR TONIGHT. ANOTHER BREEZY EVE ACROSS THE WATERS WITH SUSTAINED WIND SPEEDS AROUND 20 KT. THESE WINDS ARE EXPECTED TO CONTINUE TONIGHT WITH LOW-LEVEL JETTING ON THE ORDER OF 20 TO 25 KT WELL INTO THE NIGHT. LATER TONIGHT...UPSTREAM CONVECTION IS EXPECTED TO REDEVELOP OR PERHAPS EVEN MOVE OUT ACROSS THE SOUTH CAROLINA WATERS. SEAS WILL BE 3 TO 5 FT...HIGHEST OFFSHORE. WINDS AND SEAS WILL BE HIGHER IN THUNDERSTORMS. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...SWLY WINDS WILL GENERALLY INCREASE OVER THE WATERS IN ADVANCE OF A STRONG COLD FRONT. ON FRIDAY WINDS WILL LIKELY BE IN THE 10 TO 15 KT RANGE...INCREASING TO 15 TO 20 KT ON SATURDAY. WINDS WILL SLACKEN IN THE EARLY MORNING HOURS OF SUNDAY AS THE FRONT APPROACHES THE WATERS. SEAS WILL LIKEWISE GRADUALLY BUILD THROUGH THE PERIOD...SUBSIDING A BIT TOWARDS DAYBREAK ON SUNDAY MORNING. AT THIS POINT IT DOES NOT LOOK LIKE SEAS WILL BUILD HIGH ENOUGH TO NEED AND ADVISORY PRODUCTS. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 PM THURSDAY...COLD FRONT WILL BE MOVING OFFSHORE SUNDAY MORNING...WITH WINDS VEERING FROM W/SW EARLY SUNDAY AT 10-15 KT...TO NW AT AROUND 10 KT SUNDAY NIGHT. LARGE CANADIAN HIGH PRESSURE WILL BUILD DOWN ACROSS THE AREA EARLY NEXT WEEK...CREATING A WEAK PRESSURE GRADIENT AND LIGHT N/NE WINDS MONDAY...INCREASING SLIGHTLY ON TUESDAY TO AROUND 10 KT AS THE RIDGING INTENSIFIES DOWN THE COAST. THE PERIOD WILL BE BOOKENDED BY 2-4 FT SEAS BOTH SUNDAY ON THE W/SW WINDS AND AGAIN LATE TUESDAY WITH THE INCREASING NE WINDS. OTHERWISE EXPECT JUST 1-2 FT BENEATH THE LIGHT GRADIENT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RJD SHORT TERM...REK LONG TERM...JDW AVIATION...MAC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
316 PM EDT WED SEP 9 2015 .SYNOPSIS... LATE SUMMER WEATHER WILL BE IN PLACE TODAY WITH HIGH HUMIDITY AND SCATTERED THUNDERSTORMS. CLOUDS AND RAIN CHANCES REMAIN THROUGH LATE IN THE WEEK WITH THE SLOW APPROACH OF A COLD FRONT. THIS FRONT MAY STALL IN THE AREA UNTIL EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM WEDNESDAY...ISOLATED SHOWERS AND THUNDERSTORMS CONTINUE GENERALLY IN THE REGION THE HRRR HAD INDICATED BUT NOT THE COVERAGE IT WAS ADVERTISING. THE CONVECTION IS GENERALLY EAST OF A LINE FROM LUMBERTON TO MYRTLE BEACH TO GEORGETOWN. OVERNIGHT IT IS VERY HARD TO DETECT A SIGNIFICANT SHORTWAVE AS WE HAD LAST NIGHT. THE MODELS ARE SHOWING THE SURFACE LOW PRESSURE AREA DEPICTED BY THE MODELS WEAKENING AS IT DRIFTS NORTHWARD. THUS WILL PROVIDE LITTLE FORCING SO HAVE KEPT ONLY ISOLATED CONVECTION FOR THE OVERNIGHT PERIOD. FOR LOW TEMPERATURES ARE EXPECTED TO FALL INTO THE LOWER TO MIDDLE 70S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...A WARM AND MOIST AIRMASS WILL REMAIN IN PLACE OVER THE EASTERN CAROLINAS IN ADVANCE OF A SLOW-MOVING COLD FRONT...WHICH WILL BE POSITIONED TO THE NW OVER THE APPALACHIANS BY THE END OF THE SHORT TERM. THIS FRONT WILL BE PRECEDED BY A PRE-FRONTAL TROUGH...WHILE AT THE MID LEVELS AN H/5 TROUGH DEEPENS OVER EASTERN CONUS. AMPLE MOISTURE AND A SERIES OF UPPER DISTURBANCES ROUNDING THE BASE OF THE H/5 TROUGH MEANS CHANCE POPS WILL REMAIN IN PLAY FOR BOTH THURSDAY AND FRIDAY. BEST CHANCES FOR CONVECTION WILL ACTUALLY BE ON FRIDAY...WHEN GUIDANCE SUGGESTS WE WILL HAVE THE DEEPEST MOISTURE AND WHEN THE PREFRONTAL TROUGH IMPINGES UPON THE CWA. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 3 PM WEDNESDAY...LOOKS LIKE UNSETTLED WEATHER WILL EXIST THROUGH MUCH OF THE WEEKEND AS LINGERING FRONT/LOW PRESSURE TROUGH REMAINS OVER INLAND CAROLINAS THROUGH SATURDAY INTO EARLY SUNDAY. WINDS WILL BASICALLY STAY SW THROUGH THE COLUMN SAT THROUGH SUNDAY MORNING WITH DEEP LAYER MOISTURE AND MINOR PERTURBATIONS RIDING AROUND THE DEEP LONG WAVE MID TO UPPER LEVEL DIGGING DOWN FROM THE GREAT LAKES TO THE GULF COAST. MAY SEE A DRY PUNCH THROUGH SATURDAY WITH A DROP IN PCP WATER VALUES DOWN TO LESS THAN 1.5 INCHES...MAINLY INLAND EARLIER IN THE DAY. PCP WATER VALUES UP NEAR 2 INCHES ALONG THE CAPE FEAR COAST WILL SEE SOME DRYING OUT BUT OVERALL EXPECT A MOIST AND UNSTABLE AIR MASS WITH INCREASED POTENTIAL FOR SHWRS AND TSTMS THROUGH SATURDAY INTO EARLY SUNDAY BEFORE NEXT COLD FRONT MOVES IN. ECMWF REMAINS SLIGHTLY DRIER AS POSITION OF UPPER TROUGH FARTHER EAST THROUGH SATURDAY BUT WILL HAVE TO SEE WHAT NEW MODEL RUN BRINGS. THIS MID TO UPPER TROUGH WILL PUSH A COLD FRONT EAST THROUGH THE CAROLINAS ON SUNDAY WITH PLENTY OF DRY AIR BEHIND IT. THIS RUSH OF DRY AND RELATIVELY COOLER AIR SHOULD MAKE ITS WAY IN THROUGH SUN AFTN AS PCP WATER VALUES DROP TO LESS THAN AN INCH WITH AN ADDITIONAL DROP DOWN TO LESS THAN A HALF INCH BY MON INTO TUES. 850 TEMPS SHOW A DROP FROM NEAR 17C SAT EVENING TO 11C BY MON MORNING. THEREFORE EXPECT TEMPS DOWN BELOW NORMAL...CLOSER TO 80 FOR HIGHS AND DEWPOINT TEMPS DOWN BELOW 50 IN SPOTS INLAND AND MID 50S MOST PLACES MON INTO TUES. THIS VERY DRY AIR IN PLACE WILL CREATE LARGER DIURNAL RANGES WITH LOW TEMPS TO DROP INTO THE 50S AND 60S ALONG THE COAST SUN NIGHT AND MON NIGHT. OVERALL EXPECT UNSETTLED WEATHER WITH PLENTY OF CLOUDS AND INCREASED POTENTIAL FOR SHWRS/TSTMS IN A MORE HUMID AIR MASS AHEAD OF COLD FRONT THROUGH EARLY SUNDAY. THEN MUCH LESS HUMID WEATHER WITH COOLER NIGHT AND WARMER EVE THROUGH TUES AS DRY HIGH PRESSURE DOMINATES OUR WEATHER. BY LATE NEXT WED WINDS WILL COME AROUND BECOMING MORE ON SHORE WITH A SLIGHT INCREASE IN MOISTURE BUT ANY PCP SHOULD HOLD OFF UNTIL WED NIGHT OR THURS. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...THE CONVERGENT BAND OF CONVECTION SPOOLING OFF OF A LOW IN GEORGIA HAS MOVED THROUGH THE CWA...HOWEVER THE ATMOSPHERE EXPECTED TO RELOAD WITH INSTABILITY BY TAF TIME. EXPECT THE RESULTANT BOUNDARY TO BE THE FOCUS FOR CONVECTION NEAR SHORE...WITH ISOLATED ACTIVITY INLAND. BRIEF IFR POSSIBLE...BUT MVFR IN SHOWERS FOR THE MOST PART. MOST OF THE ACTIVITY WILL DIMINISH BY LATE AFTERNOON. OVERNIGHT...SOME LIGHT FOG COMBINED WITH MVFR/NEAR IFR CEILINGS TOWARD MORNING WITH CONTINUED LOW LEVEL MOISTURE. COULD NOT RULE OUT A SHOWER BASED ON THE NAM...HOWEVER IT HAS BEEN OVERDOING IT THROUGH THE OVERNIGHT HOURS. THURSDAY...CONTINUED HOT AND HUMID WITH AFTERNOON CONVECTION POSSIBLE. SOUTHWEST GRADIENT WILL BE STRONGER THAN TODAY...BECOMING GUSTY IN THE AFTERNOON. EXTENDED OUTLOOK...POSSIBLE NUMEROUS STORMS FRIDAY AND SATURDAY. STORMS ENDING SUNDAY MORNING WITH COOLER CONDITIONS INTO MONDAY.&& && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM WEDNESDAY...SOUTH TO SOUTH-SOUTHWEST WINDS OF 10 TO 15 KTS WITH SEAS OF 2 TO 3 FEET ARE CURRENTLY OCCURRING OVER THE COASTAL WATERS. AS HIGH PRESSURE WEAKENS SLOWLY OVERNIGHT AND THE INFLUENCE OF A COLD FRONT WEST OF THE CAROLINAS WILL CAUSE THE WINDS TO BECOME MORE SOUTHWESTERLY OVERNIGHT. WINDS SPEEDS ARE FORECAST TO RUN AROUND 15 KNOT. SEAS WILL RUN AROUND 3 FEET WITH A FEW 4 FOOTS IN THE SOUTHEAST PORTIONS OF THE LITTLE RIVER TO CAPE FEAR MARINE ZONE. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...WINDS WILL REMAIN SOUTHWESTERLY THROUGH THE PERIOD AS A COLD FRONT SLOWLY ADVANCES UPON THE WATERS. THE FRONT WILL NOT MAKE IT TO THE WATERS DURING THE NEAR TERM...BUT WE WILL LIKELY SEE A GRADUAL TIGHTENING OF THE GRADIENT...WHICH WILL INCREASE WINDS FROM A GENERAL 10 TO 15 KT RANGE TO AROUND 15 KTS OR SO BY FRIDAY NIGHT. SEAS WILL LIKEWISE INCREASE...WITH 3 TO 4 FT SEAS DEVELOPING FRIDAY/FRIDAY NIGHT. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 PM WEDNESDAY...DECENT SW FLOW THROUGH MUCH OF THE WEEKEND AS TROUGH OF LOW PRESSURE REMAINS JUST INLAND OF COAST. DECENT GRADIENT THROUGH SAT MORNING WITH SW WINDS UP TO 15 KTS WILL DIMINISH THROUGH LATE SATURDAY INTO SUNDAY AS WINDS BEGIN TO VEER AROUND AS COLD FRONT APPROACHES FROM THE WEST. LATEST WNA SHOWS WIND SHIFT TO W-NW BY LATE SUNDAY AS COLD FRONT CROSSES THE WATERS. PERSISTENT SW WINDS WILL PUSH SEAS UP TO 3 TO 5 FT THROUGH SAT AND THEN DIMINISHING WITH OFF SHORE FLOW THROUGH LATE SUNDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...REK NEAR TERM...DRH SHORT TERM...REK/MBB LONG TERM...RGZ AVIATION...DL MARINE...REK/RGZ/DRH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
138 PM EDT WED SEP 9 2015 .SYNOPSIS... SUMMER LIKE HEAT WILL BE IN PLACE TODAY WITH SCATTERED THUNDERSTORMS...MOST NUMEROUS ALONG THE COAST. CLOUDS AND RAIN CHANCES THEN INCREASE LATE IN THE WEEK WITH THE SLOW APPROACH OF A COLD FRONT. THIS BOUNDARY MAY NOT PUSH THROUGH UNTIL MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1 PM WEDNESDAY...ISOLATED SHOWERS AND THUNDERSTORMS CONTINUE BEHIND THIS MORNINGS SHORTWAVE. MOST OF THIS AFTERNOONS CONVECTION IS EAST OF A LINE FROM LUMBERTON TO MYRTLE BEACH TO GEORGETOWN. THE 15/16 HRRR CONTINUE TO SHOW CONVECTION WANING LATER THIS AFTERNOON AND ONLY ISOLATED CONVECTION AFTER SUNSET. OVERNIGHT IT IS VERY HARD TO DETECT A SIGNIFICANT SHORTWAVE AS WAS EARLY THOUGHT. THE LOW PRESSURE AREA IS DEPICTED BY THE MODELS OF WEAKENING AS IT DRIFTS NORTHWARD. THUS WILL LITTLE FORCING HAVE KEPT ONLY ISOLATED FOR THE OVERNIGHT PERIOD. FOR LOW TEMPERATURES AREA EXPECTED TO FALL INTO THE LOWER TO MIDDLE 70S. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY... PREFRONTAL TROUGH MOVES INTO THE CAROLINAS AND STALLS ON THURSDAY. AHEAD OF THIS FEATURE THERE SHOULD BE AMPLE MOISTURE FOR AT LEAST SCATTERED CONVECTIVE COVERAGE. MID LEVEL FORCING IN THE FORM OF VORT MAXES COME LATE IN THE DAY AND AT NIGHT PREVENTING THE NORMAL DIURNAL DYING OFF OF RADAR COVERAGE EVEN THOUGH DEEP CONVECTION MAY BE HARDER TO COME BY DUE TO THE DECREASE IN INSTABILITY. THIS BOUNDARY WEAKENS AND MOVES OFFSHORE BY FRIDAY AND WAS PREVIOUSLY TO BE REPLACED BY A LEGITIMATE COLD FRONT. THIS FRONT NOW APPEARS SLOWER LEAVING NOT MUCH IN THE WAY OF SURFACE FEATURES IN PLACE LOCALLY. FURTHER COMPLICATING FRIDAY FORECAST IS THE DIFFERENCE IN TIMING AMONGST MODELS WITH RESPECT TO SOME MID LEVEL IMPULSES. IN THE END DID NOT MAKE MUCH CHANGE AND WILL ONCE AGAIN CARRY CHANCE POPS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY... IMPRESSIVELY DEEP UPPER TROUGH DRIVES COLD FRONT INTO THE COASTAL PLAIN ON SATURDAY. BEING ALIGNED WITH THE FLOW ALOFT IT WILL STALL ON SUNDAY. SATURDAY OFFERS THE DEEPEST MOISTURE AND WILL LIKELY PAN OUT BEING A VERY UNSETTLED DAY WITH PERHAPS NUMEROUS SHOWERS AND IF THE DIURNAL TIMING IS RIGHT STRONGER THUNDERSTORMS. MODELS AT SOME ODDS REGARDING THE DEPTH AND TILT OF THE UPPER WAVE AND UNTIL IT ENTERS THE UPPER AIR NETWORK ITS HARD TO SPECULATE WHICH IS CORRECT. ON SUNDAY THE DEEP MOISTURE GETS SHUNTED OFFSHORE BUT SOME LOW LEVEL MOISTURE ALONG THE BOUNDARY WILL STILL CALL FOR SOME LOW RAIN CHANCES MAINLY ALONG THE COAST. COOLER AND DRYER AIR NOW APPEARS TO ARRIVE FASTER AND SHOULD BE ADVECTING IN MODERATELY STRONGLY BY MONDAY. COOLER WEATHER WILL LAST INTO TUESDAY AS THE CENTER OF THE LARGE HIGH BUILDS TO OUR NORTH. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...THE CONVERGENT BAND OF CONVECTION SPOOLING OFF OF A LOW IN GEORGIA HAS MOVED THROUGH THE CWA...HOWEVER THE ATMOSPHERE EXPECTED TO RELOAD WITH INSTABILITY BY TAF TIME. EXPECT THE RESULTANT BOUNDARY TO BE THE FOCUS FOR CONVECTION NEAR SHORE...WITH ISOLATED ACTIVITY INLAND. BRIEF IFR POSSIBLE...BUT MVFR IN SHOWERS FOR THE MOST PART. MOST OF THE ACTIVITY WILL DIMINISH BY LATE AFTERNOON. OVERNIGHT...SOME LIGHT FOG COMBINED WITH MVFR/NEAR IFR CEILINGS TOWARD MORNING WITH CONTINUED LOW LEVEL MOISTURE. COULD NOT RULE OUT A SHOWER BASED ON THE NAM...HOWEVER IT HAS BEEN OVERDOING IT THROUGH THE OVERNIGHT HOURS. THURSDAY...CONTINUED HOT AND HUMID WITH AFTERNOON CONVECTION POSSIBLE. SOUTHWEST GRADIENT WILL BE STRONGER THAN TODAY...BECOMING GUSTY IN THE AFTERNOON. EXTENDED OUTLOOK...POSSIBLE NUMEROUS STORMS FRIDAY AND SATURDAY. STORMS ENDING SUNDAY MORNING WITH COOLER CONDITIONS INTO MONDAY.&& .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 PM WEDNESDAY...SOUTH TO SOUTH-SOUTHWEST WINDS OF 10 TO 15 KTS WITH SEAS OF 2 TO 3 FEET CURRENTLY ARE OCCURRING OVER THE COASTAL WATERS. HIGH PRESSURE WILL SLOWLY LESSEN ITS IMPACT BY THIS EVENING AS A COLD FRONT WELL TO THE WEST MOVES CLOSER TO THE CAROLINAS. WINDS ARE EXPECTED TO SHIFT MORE TO THE SOUTHWEST AND INCREASE TO 10 TO 15 KNOTS. SEAS WILL GRADUALLY INCREASE TO 3 FEET. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY... A PREFRONTAL TROUGH WILL BOOST WIND AND SEAS ON THURSDAY. WE ARE NOT ANTICIPATING HEADLINES OR ADVISORIES, BUT ITS BEEN FAIRLY QUIET SO THURSDAY WILL BE MORE UNSETTLED THAN THE PAST FEW DAYS WITH THE ADVENT OF SOME 4 FT SEAS. ON FRIDAY THIS BOUNDARY MOVES OFFSHORE AND WEAKENS IF NOT DISSIPATE ALTOGETHER. THE 20KT GUSTINESS SHOULD DROP OUT OF THE FORECAST AS WILL ANY 4 FT WAVES. A COLD FRONT WILL ALSO BE APPROACHING FROM THE NW ON FRIDAY BUT IT NOW LOOKS SLOWER THAN PREVIOUSLY FORECAST. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY... WITH THE SLOWER ARRIVAL OF COLD FRONT ON SATURDAY THE AREA MAY STAY IN AN INCREASED GRADIENT PRE-FRONTAL FLOW REGIME. AS SUCH WIND SPEEDS MAY NEED TO BE RE-EVALUATED AND RAISED ESPECIALLY AS SOME HIGHER MID LEVEL WINDS MAY BE IMPINGING UPON THE AREA. THE UPPER WAVE DRIVING THIS SYSTEM IS FAR FROM BEING SAMPLED BY THE UPPER AIR NETWORK HOWEVER AND SO NO LARGE CHANGES WILL BE MADE AT THIS TIME. SHOULD THINGS KEEP SLOWING DOWN THEN A SW WIND WILL REMAIN ON SUNDAY AS THE BOUNDARY EITHER STALLS ALONG THE COAST OR PERHAPS JUST INLAND. EITHER WAY THE STRONGER GRADIENT WILL HAVE PUSHED FURTHER OFFSHORE AND THE POSSIBILITY OF HIGHER WINDS AND SEAS THAN THE CURRENT FORECAST ALONG WITH IT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DRH SHORT TERM...MBB LONG TERM...MBB AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1019 AM EDT WED SEP 9 2015 .SYNOPSIS... SUMMER LIKE HEAT WILL BE IN PLACE TODAY WITH SCATTERED THUNDERSTORMS...MOST NUMEROUS ALONG THE COAST. CLOUDS AND RAIN CHANCES THEN INCREASE LATE IN THE WEEK WITH THE SLOW APPROACH OF A COLD FRONT. THIS BOUNDARY MAY NOT PUSH THROUGH UNTIL MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 10 AM WEDNESDAY...THE SHORTWAVE MOVING UP THE CAROLINA COAST IS PRODUCING A LINE OF SHOWERS AND THUNDERSTORMS THAT IS QUICKLY MOVING ACROSS SOUTHEAST NORTH CAROLINA. THE ATMOSPHERE CONTINUES TO BE VERY MOIST WITH PRECIPITABLE WATER AROUND 2 INCHES ALONG THE COAST. THE 12 UTC HRRR IS SHOWING THE INITIAL BAND OF CONVECTION SHIFTING TO THE NORTHEAST WITH ADDITIONAL CONVECTION DEVELOPING AROUND 15 UTC ALONG OUR ENTIRE COAST BUT QUICKLY ENDING BY MID-AFTERNOON AS THE SUBSIDENCE AND SLIGHTLY DRIER AIR WORKS ITS WAY BEHIND THE SHORTWAVE. WITH WARMER TEMPERATURES ALOFT AND CLEARING SKIES WILL PUSH TEMPERATURES INTO THE LOWER 90S INLAND WITH UPPER 80S ON THE COAST. THIS IS STILL 5 OR MORE DEGREES AWAY FROM RECORDS. WITH DEWPOINTS REMAINING IN THE LOWER TO MID 70S HEAT INDEX VALUES SHOULD REACH 100 DEGREES ACROSS PARTS OF THE PEE DEE REGION. TONIGHT ANOTHER UPPER DISTURBANCE TAKING A MORE INLAND TRACK COULD SPREAD EVENING SHOWERS AND STORMS ACROSS THE I-95 CORRIDOR. I HAVE NOT GONE TOO HIGH WITH POPS HOWEVER GIVEN THE COOLING/STABILIZING BOUNDARY LAYER AND THE BEST LIFT WITH THE DISTURBANCE EXPECTED TO PASS ACROSS CENTRAL AND WESTERN NORTH CAROLINA. AS LOW LEVEL WINDS TURN SOUTHWESTERLY A MODEST LOW LEVEL JET SHOULD DEVELOP WITH 975 MB (1000 FOOT AGL) WINDS INCREASING TO 20-25 KT. THIS SHOULD HELP KEEP A STRONG NOCTURNAL INVERSION FROM DEVELOPING AND LOWS SHOULD ONLY FALL TO 72-75 INLAND AND 75-78 AT THE COAST...ABOUT 7 DEGREES ABOVE NORMAL FOR THE DATE. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY... PREFRONTAL TROUGH MOVES INTO THE CAROLINAS AND STALLS ON THURSDAY. AHEAD OF THIS FEATURE THERE SHOULD BE AMPLE MOISTURE FOR AT LEAST SCATTERED CONVECTIVE COVERAGE. MID LEVEL FORCING IN THE FORM OF VORT MAXES COME LATE IN THE DAY AND AT NIGHT PREVENTING THE NORMAL DIURNAL DYING OFF OF RADAR COVERAGE EVEN THOUGH DEEP CONVECTION MAY BE HARDER TO COME BY DUE TO THE DECREASE IN INSTABILITY. THIS BOUNDARY WEAKENS AND MOVES OFFSHORE BY FRIDAY AND WAS PREVIOUSLY TO BE REPLACED BY A LEGITIMATE COLD FRONT. THIS FRONT NOW APPEARS SLOWER LEAVING NOT MUCH IN THE WAY OF SURFACE FEATURES IN PLACE LOCALLY. FURTHER COMPLICATING FRIDAY FORECAST IS THE DIFFERENCE IN TIMING AMONGST MODELS WITH RESPECT TO SOME MID LEVEL IMPULSES. IN THE END DID NOT MAKE MUCH CHANGE AND WILL ONCE AGAIN CARRY CHANCE POPS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY... IMPRESSIVELY DEEP UPPER TROUGH DRIVES COLD FRONT INTO THE COASTAL PLAIN ON SATURDAY. BEING ALIGNED WITH THE FLOW ALOFT IT WILL STALL ON SUNDAY. SATURDAY OFFERS THE DEEPEST MOISTURE AND WILL LIKELY PAN OUT BEING A VERY UNSETTLED DAY WITH PERHAPS NUMEROUS SHOWERS AND IF THE DIURNAL TIMING IS RIGHT STRONGER THUNDERSTORMS. MODELS AT SOME ODDS REGARDING THE DEPTH AND TILT OF THE UPPER WAVE AND UNTIL IT ENTERS THE UPPER AIR NETWORK ITS HARD TO SPECULATE WHICH IS CORRECT. ON SUNDAY THE DEEP MOISTURE GETS SHUNTED OFFSHORE BUT SOME LOW LEVEL MOISTURE ALONG THE BOUNDARY WILL STILL CALL FOR SOME LOW RAIN CHANCES MAINLY ALONG THE COAST. COOLER AND DRYER AIR NOW APPEARS TO ARRIVE FASTER AND SHOULD BE ADVECTING IN MODERATELY STRONGLY BY MONDAY. COOLER WEATHER WILL LAST INTO TUESDAY AS THE CENTER OF THE LARGE HIGH BUILDS TO OUR NORTH. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...SHOWERS ARE MOVING TOWARD THE MYRTLES AND THE HRRR MODEL INITIALIZED WELL WITH THIS. ONLY A LITTLE BIT OF HEATING TODAY WILL KICK OFF MORE SHOWERS AS THE LFC IS FAIRLY LOW. LOOK FOR CONVECTION TO MOVE INTO ILM BY MID MORNING WITH THUNDER A DECENT BET. MAINLY MVFR CEILINGS WITH TEMPO IFR VISIBILITIES IN THE HEAVIER RAIN. INLAND...DENSE FOG WILL PERSIST THROUGH AT LEAST 14Z WITH GRADUAL IMPROVEMENT TO VFR BY 15-16Z. SOME CONVECTION WILL ALSO MOVE INTO THIS REGION IN THE AFTERNOON...HOWEVER COVERAGE WILL NOT BE A WIDESPREAD AS THE COAST WHICH WILL HAVE THE RESULTANT BOUNDARY TO WORK WITH. EXTENDED OUTLOOK...SCATTERED CONVECTION ON THURSDAY WITH POSSIBLE NUMEROUS STORMS FRIDAY AND SATURDAY. STORMS ENDING SUNDAY MORNING WITH COOLER CONDITIONS INTO MONDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 10 AM WEDNESDAY...SOUTH-SOUTHWEST WINDS OF 10 KTS WITH SEAS OF 2 TO 2.5 FEET THIS MORNING ARE OCCURRING OVER THE COASTAL WATERS. HIGH PRESSURE WILL SLOWLY LESSEN ITS IMPACT BY THIS EVENING AS A COLD FRONT WELL TO THE WEST MOVES CLOSER TO THE CAROLINAS. WINDS ARE EXPECTED TO SHIFT MORE TO THE SOUTHWEST AND INCREASE TO 10 TO 15 KNOTS. SEAS WILL GRADUALLY INCREASE TO 3 FEET. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY... A PREFRONTAL TROUGH WILL BOOST WIND AND SEAS ON THURSDAY. WE ARE NOT ANTICIPATING HEADLINES OR ADVISORIES, BUT ITS BEEN FAIRLY QUIET SO THURSDAY WILL BE MORE UNSETTLED THAN THE PAST FEW DAYS WITH THE ADVENT OF SOME 4 FT SEAS. ON FRIDAY THIS BOUNDARY MOVES OFFSHORE AND WEAKENS IF NOT DISSIPATE ALTOGETHER. THE 20KT GUSTINESS SHOULD DROP OUT OF THE FORECAST AS WILL ANY 4 FT WAVES. A COLD FRONT WILL ALSO BE APPROACHING FROM THE NW ON FRIDAY BUT IT NOW LOOKS SLOWER THAN PREVIOUSLY FORECAST. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY... WITH THE SLOWER ARRIVAL OF COLD FRONT ON SATURDAY THE AREA MAY STAY IN AN INCREASED GRADIENT PRE-FRONTAL FLOW REGIME. AS SUCH WIND SPEEDS MAY NEED TO BE RE-EVALUATED AND RAISED ESPECIALLY AS SOME HIGHER MID LEVEL WINDS MAY BE IMPINGING UPON THE AREA. THE UPPER WAVE DRIVING THIS SYSTEM IS FAR FROM BEING SAMPLED BY THE UPPER AIR NETWORK HOWEVER AND SO NO LARGE CHANGES WILL BE MADE AT THIS TIME. SHOULD THINGS KEEP SLOWING DOWN THEN A SW WIND WILL REMAIN ON SUNDAY AS THE BOUNDARY EITHER STALLS ALONG THE COAST OR PERHAPS JUST INLAND. EITHER WAY THE STRONGER GRADIENT WILL HAVE PUSHED FURTHER OFFSHORE AND THE POSSIBILITY OF HIGHER WINDS AND SEAS THAN THE CURRENT FORECAST ALONG WITH IT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...HAWKINS/TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
642 AM EDT WED SEP 9 2015 .SYNOPSIS... SUMMERLIKE HEAT WILL BE IN PLACE TODAY WITH SCATTERED THUNDERSTORMS...MOST NUMEROUS ALONG THE COAST. CLOUDS AND RAIN CHANCES THEN INCREASE LATE IN THE WEEK WITH THE SLOW APPROACH OF A COLD FRONT. THIS BOUNDARY MAY NOT PUSH THROUGH UNTIL MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 645 AM WEDNESDAY...SURFACE HIGH PRESSURE NORTH OF BERMUDA WILL PROVIDE A WARM AND HUMID AIRMASS TO THE CAROLINAS TODAY STRAIGHT OUT OF THE BAHAMAS. 850 MB TEMP EXPECTED TO HOVER AROUND +18C IS NEAR THE 95TH PERCENTILE FOR CLIMATOLOGICAL READINGS THIS TIME OF YEAR AT CHS. AS A RESULT WE SHOULD SEE HIGH TEMPERATURES RISE INTO THE LOWER 90S INLAND WITH UPPER 80S ON THE COAST. THIS IS STILL 5 OR MORE DEGREES AWAY FROM RECORDS. WITH DEWPOINTS REMAINING IN THE LOWER TO MID 70S HEAT INDEX VALUES SHOULD REACH 100 DEGREES ACROSS PARTS OF THE PEE DEE REGION. AN UPPER DISTURBANCE CURRENTLY MOVING NORTHEASTWARD THROUGH COASTAL SOUTH CAROLINA IS HELPING SUPPORT A CLUSTER OF SHOWERS & THUNDERSTORMS NEAR GEORGETOWN/MURRELLS INLET. THIS DISTURBANCE SHOULD MOVE THROUGH MYRTLE BEACH AFTER SUNRISE...REACHING SE NORTH CAROLINA BY LATE THIS MORNING. HIGH RES MODELS INCLUDING THE NSSL WRF...THE LATEST SEVERAL HRRR RUNS...AND THE ARW AND NMM VERSIONS OF THE WRF ALL SUPPORT THE IDEA OF CONVECTION BECOMING MORE WIDESPREAD ACROSS SE NORTH CAROLINA AROUND 14-15Z (10-11 AM) AS THE UPPER DISTURBANCE ENCOUNTERS AN UNCAPPED AIRMASS WITH SURFACE-BASED CAPE IN EXCESS OF 2000 J/KG. I HAVE INCREASED POPS TO 40-60 PERCENT IN THE CAPE FEAR REGION...WITH POPS ELSEWHERE IN THE 10-30 PERCENT RANGE GIVEN PROBABLE SUBSIDENCE AND MID-LEVEL DRYING BEHIND THE UPPER DISTURBANCE. CONVECTION SHOULD TEND TO MOVE NORTHEASTWARD DURING THE MID TO LATE AFTERNOON...FOLLOWING THE DISTURBANCE INTO FAR-EASTERN NORTH CAROLINA. TONIGHT ANOTHER UPPER DISTURBANCE TAKING A MORE INLAND TRACK COULD SPREAD EVENING SHOWERS AND STORMS ACROSS THE I-95 CORRIDOR. I HAVE NOT GONE TOO HIGH WITH POPS HOWEVER GIVEN THE COOLING/STABILIZING BOUNDARY LAYER AND THE BEST LIFT WITH THE DISTURBANCE EXPECTED TO PASS ACROSS CENTRAL AND WESTERN NORTH CAROLINA. AS LOW LEVEL WINDS TURN SOUTHWESTERLY A MODEST LOW LEVEL JET SHOULD DEVELOP WITH 975 MB (1000 FOOT AGL) WINDS INCREASING TO 20-25 KT. THIS SHOULD HELP KEEP A STRONG NOCTURNAL INVERSION FROM DEVELOPING AND LOWS SHOULD ONLY FALL TO 72-75 INLAND AND 75-78 AT THE COAST...ABOUT 7 DEGREES ABOVE NORMAL FOR THE DATE. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY... PREFRONTAL TROUGH MOVES INTO THE CAROLINAS AND STALLS ON THURSDAY. AHEAD OF THIS FEATURE THERE SHOULD BE AMPLE MOISTURE FOR AT LEAST SCATTERED CONVECTIVE COVERAGE. MID LEVEL FORCING IN THE FORM OF VORT MAXES COME LATE IN THE DAY AND AT NIGHT PREVENTING THE NORMAL DIURNAL DYING OFF OF RADAR COVERAGE EVEN THOUGH DEEP CONVECTION MAY BE HARDER TO COME BY DUE TO THE DECREASE IN INSTABILITY. THIS BOUNDARY WEAKENS AND MOVES OFFSHORE BY FRIDAY AND WAS PREVIOUSLY TO BE REPLACED BY A LEGITIMATE COLD FRONT. THIS FRONT NOW APPEARS SLOWER LEAVING NOT MUCH IN THE WAY OF SURFACE FEATURES IN PLACE LOCALLY. FURTHER COMPLICATING FRIDAY FORECAST IS THE DIFFERENCE IN TIMING AMONGST MODELS WITH RESPECT TO SOME MID LEVEL IMPULSES. IN THE END DID NOT MAKE MUCH CHANGE AND WILL ONCE AGAIN CARRY CHANCE POPS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY... IMPRESSIVELY DEEP UPPER TROUGH DRIVES COLD FRONT INTO THE COASTAL PLAIN ON SATURDAY. BEING ALIGNED WITH THE FLOW ALOFT IT WILL STALL ON SUNDAY. SATURDAY OFFERS THE DEEPEST MOISTURE AND WILL LIKELY PAN OUT BEING A VERY UNSETTLED DAY WITH PERHAPS NUMEROUS SHOWERS AND IF THE DIURNAL TIMING IS RIGHT STRONGER THUNDERSTORMS. MODELS AT SOME ODDS REGARDING THE DEPTH AND TILT OF THE UPPER WAVE AND UNTIL IT ENTERS THE UPPER AIR NETWORK ITS HARD TO SPECULATE WHICH IS CORRECT. ON SUNDAY THE DEEP MOISTURE GETS SHUNTED OFFSHORE BUT SOME LOW LEVEL MOISTURE ALONG THE BOUNDARY WILL STILL CALL FOR SOME LOW RAIN CHANCES MAINLY ALONG THE COAST. COOLER AND DRYER AIR NOW APPEARS TO ARRIVE FASTER AND SHOULD BE ADVECTING IN MODERATELY STRONGLY BY MONDAY. COOLER WEATHER WILL LAST INTO TUESDAY AS THE CENTER OF THE LARGE HIGH BUILDS TO OUR NORTH. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... AS OF 12Z...SHOWERS ARE MOVING TOWARD THE MYRTLES AND THE HRRR MODEL INITIALIZED WELL WITH THIS. ONLY A LITTLE BIT OF HEATING TODAY WILL KICK OFF MORE SHOWERS AS THE LFC IS FAIRLY LOW. LOOK FOR CONVECTION TO MOVE INTO ILM BY MID MORNING WITH THUNDER A DECENT BET. MAINLY MVFR CEILINGS WITH TEMPO IFR VISIBILITIES IN THE HEAVIER RAIN. INLAND...DENSE FOG WILL PERSIST THROUGH AT LEAST 14Z WITH GRADUAL IMPROVEMENT TO VFR BY 15-16Z. SOME CONVECTION WILL ALSO MOVE INTO THIS REGION IN THE AFTERNOON...HOWEVER COVERAGE WILL NOT BE A WIDESPREAD AS THE COAST WHICH WILL HAVE THE RESULTANT BOUNDARY TO WORK WITH. EXTENDED OUTLOOK...SCATTERED CONVECTION ON THURSDAY WITH POSSIBLE NUMEROUS STORMS FRIDAY AND SATURDAY. STORMS ENDING SUNDAY MORNING WITH COOLER CONDITIONS INTO MONDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 645 AM WEDNESDAY...HIGH PRESSURE NORTH OF BERMUDA WILL BE OUR CONTROLLING WEATHER SYSTEM THROUGH TONIGHT. TODAY`S SOUTH WINDS WILL VEER MORE SOUTHWESTERLY TONIGHT AS A COLD FRONT...CURRENTLY MOVING SE ACROSS ILLINOIS AND WISCONSIN...MOVES INTO WEST VIRGINIA AND KENTUCKY. AN UPPER LEVEL DISTURBANCE CURRENTLY MOVING NORTHEASTWARD ACROSS COASTAL SOUTH CAROLINA WILL SPREAD SCATTERED SHOWERS ALONG THE NORTHEASTERN SOUTH CAROLINA COAST THIS MORNING. LATEST HIGH-RES MODELS INDICATE COVERAGE OF STORMS WILL EXPAND ONCE THE DISTURBANCE REACHES SOUTHEASTERN NORTH CAROLINA LATE THIS MORNING. STEERING WINDS IN THE ATMOSPHERE WILL TEND TO PUSH STORMS NORTHEASTWARD AT 10 MPH...HOWEVER ASSUMING ENOUGH STORMS FORM COLLIDING OUTFLOW BOUNDARIES WILL ULTIMATELY DETERMINE WHERE STORMS MOVE. MARINERS IN THE CAPE FEAR AREA WILL WANT TO KEEP AN EYE ON THE SKY LATE THIS MORNING AND EARLY THIS AFTERNOON. SEAS CURRENTLY AROUND 2 FEET WILL BUILD CLOSER TO 3 FEET LATE THIS AFTERNOON AS WIND SPEEDS INCREASE WITH THE SEABREEZE. SW WINDS WILL INCREASE TO NEAR 15 KT TONIGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY... A PREFRONTAL TROUGH WILL BOOST WIND AND SEAS ON THURSDAY. WE ARE NOT ANTICIPATING HEADLINES OR ADVISORIES, BUT ITS BEEN FAIRLY QUIET SO THURSDAY WILL BE MORE UNSETTLED THAN THE PAST FEW DAYS WITH THE ADVENT OF SOME 4 FT SEAS. ON FRIDAY THIS BOUNDARY MOVES OFFSHORE AND WEAKENS IF NOT DISSIPATE ALTOGETHER. THE 20KT GUSTINESS SHOULD DROP OUT OF THE FORECAST AS WILL ANY 4 FT WAVES. A COLD FRONT WILL ALSO BE APPROACHING FROM THE NW ON FRIDAY BUT IT NOW LOOKS SLOWER THAN PREVIOUSLY FORECAST. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY... WITH THE SLOWER ARRIVAL OF COLD FRONT ON SATURDAY THE AREA MAY STAY IN AN INCREASED GRADIENT PRE-FRONTAL FLOW REGIME. AS SUCH WIND SPEEDS MAY NEED TO BE RE-EVALUATED AND RAISED ESPECIALLY AS SOME HIGHER MID LEVEL WINDS MAY BE IMPINGING UPON THE AREA. THE UPPER WAVE DRIVING THIS SYSTEM IS FAR FROM BEING SAMPLED BY THE UPPER AIR NETWORK HOWEVER AND SO NO LARGE CHANGES WILL BE MADE AT THIS TIME. SHOULD THINGS KEEP SLOWING DOWN THEN A SW WIND WILL REMAIN ON SUNDAY AS THE BOUNDARY EITHER STALLS ALONG THE COAST OR PERHAPS JUST INLAND. EITHER WAY THE STRONGER GRADIENT WILL HAVE PUSHED FURTHER OFFSHORE AND THE POSSIBILITY OF HIGHER WINDS AND SEAS THAN THE CURRENT FORECAST ALONG WITH IT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
324 AM EDT WED SEP 9 2015 .SYNOPSIS... SUMMERLIKE HEAT WILL BE IN PLACE TODAY WITH A FEW STRAY THUNDERSTORMS. CLOUDS AND RAIN CHANCES THEN INCREASE LATE IN THE WEEK WITH THE SLOW APPROACH OF A COLD FRONT. THIS BOUNDARY MAY NOT PUSH THROUGH UNTIL MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM WEDNESDAY...SURFACE HIGH PRESSURE NORTH OF BERMUDA WILL PROVIDE A WARM AND HUMID AIRMASS TO THE CAROLINAS TODAY STRAIGHT OUT OF THE BAHAMAS. 850 MB TEMP EXPECTED TO HOVER AROUND +18C IS NEAR THE 95TH PERCENTILE FOR CLIMATOLOGICAL READINGS THIS TIME OF YEAR AT CHS. AS A RESULT WE SHOULD SEE HIGH TEMPERATURES RISE INTO THE LOWER 90S INLAND WITH UPPER 80S ON THE COAST. THIS IS STILL 5 OR MORE DEGREES AWAY FROM RECORDS. WITH DEWPOINTS REMAINING IN THE LOWER TO MID 70S HEAT INDEX VALUES SHOULD REACH 100 DEGREES ACROSS PARTS OF THE PEE DEE REGION. AN UPPER DISTURBANCE CURRENTLY MOVING NORTHEASTWARD FROM GEORGIA INTO SOUTHERNMOST SOUTH CAROLINA IS HELPING SUPPORT A CLUSTER OF THUNDERSTORMS NEAR CHARLESTON. THIS DISTURBANCE SHOULD MOVE ALONG THE SOUTH CAROLINA COAST AFTER SUNRISE...REACHING SE NORTH CAROLINA BY LATE THIS MORNING. HIGH RES MODELS INCLUDING THE NSSL WRF...THE LATEST SEVERAL HRRR RUNS...AND THE ARW AND NMM VERSIONS OF THE WRF ALL SUPPORT THE IDEA OF CONVECTION BECOMING MORE WIDESPREAD ACROSS SE NORTH CAROLINA AROUND 15Z (11 AM) AS THE UPPER DISTURBANCE ENCOUNTERS AN UNCAPPED AIRMASS WITH SURFACE-BASED CAPE IN EXCESS OF 2000 J/KG. I HAVE INCREASED POPS TO 40-60 PERCENT IN THE CAPE FEAR REGION...WITH POPS ELSEWHERE IN THE 10-30 PERCENT RANGE GIVEN PROBABLE SUBSIDENCE AND MID-LEVEL DRYING BEHIND THE UPPER DISTURBANCE. CONVECTION SHOULD TEND TO MOVE NORTHEASTWARD DURING THE MID TO LATE AFTERNOON...FOLLOWING THE DISTURBANCE INTO FAR-EASTERN NORTH CAROLINA. TONIGHT ANOTHER UPPER DISTURBANCE TAKING A MORE INLAND TRACK COULD SPREAD EVENING SHOWERS AND STORMS ACROSS THE I-95 CORRIDOR. I HAVE NOT GONE TOO HIGH WITH POPS HOWEVER GIVEN THE COOLING/STABILIZING BOUNDARY LAYER AND THE BEST LIFT WITH THE DISTURBANCE EXPECTED TO PASS ACROSS CENTRAL AND WESTERN NORTH CAROLINA. AS LOW LEVEL WINDS TURN SOUTHWESTERLY A MODEST LOW LEVEL JET SHOULD DEVELOP WITH 975 MB (1000 FOOT AGL) WINDS INCREASING TO 20-25 KT. THIS SHOULD HELP KEEP A STRONG NOCTURNAL INVERSION FROM DEVELOPING AND LOWS SHOULD ONLY FALL TO 72-75 INLAND AND 75-78 AT THE COAST...ABOUT 7 DEGREES ABOVE NORMAL FOR THE DATE. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY... PREFRONTAL TROUGH MOVES INTO THE CAROLINAS AND STALLS ON THURSDAY. AHEAD OF THIS FEATURE THERE SHOULD BE AMPLE MOISTURE FOR AT LEAST SCATTERED CONVECTIVE COVERAGE. MID LEVEL FORCING IN THE FORM OF VORT MAXES COME LATE IN THE DAY AND AT NIGHT PREVENTING THE NORMAL DIURNAL DYING OFF OF RADAR COVERAGE EVEN THOUGH DEEP CONVECTION MAY BE HARDER TO COME BY DUE TO THE DECREASE IN INSTABILITY. THIS BOUNDARY WEAKENS AND MOVES OFFSHORE BY FRIDAY AND WAS PREVIOUSLY TO BE REPLACED BY A LEGITIMATE COLD FRONT. THIS FRONT NOW APPEARS SLOWER LEAVING NOT MUCH IN THE WAY OF SURFACE FEATURES IN PLACE LOCALLY. FURTHER COMPLICATING FRIDAY FORECAST IS THE DIFFERENCE IN TIMING AMONGST MODELS WITH RESPECT TO SOME MID LEVEL IMPULSES. IN THE END DID NOT MAKE MUCH CHANGE AND WILL ONCE AGAIN CARRY CHANCE POPS. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY... IMPRESSIVELY DEEP UPPER TROUGH DRIVES COLD FRONT INTO THE COASTAL PLAIN ON SATURDAY. BEING ALIGNED WITH THE FLOW ALOFT IT WILL STALL ON SUNDAY. SATURDAY OFFERS THE DEEPEST MOISTURE AND WILL LIKELY PAN OUT BEING A VERY UNSETTLED DAY WITH PERHAPS NUMEROUS SHOWERS AND IF THE DIURNAL TIMING IS RIGHT STRONGER THUNDERSTORMS. MODELS AT SOME ODDS REGARDING THE DEPTH AND TILT OF THE UPPER WAVE AND UNTIL IT ENTERS THE UPPER AIR NETWORK ITS HARD TO SPECULATE WHICH IS CORRECT. ON SUNDAY THE DEEP MOISTURE GETS SHUNTED OFFSHORE BUT SOME LOW LEVEL MOISTURE ALONG THE BOUNDARY WILL STILL CALL FOR SOME LOW RAIN CHANCES MAINLY ALONG THE COAST. COOLER AND DRYER AIR NOW APPEARS TO ARRIVE FASTER AND SHOULD BE ADVECTING IN MODERATELY STRONGLY BY MONDAY. COOLER WEATHER WILL LAST INTO TUESDAY AS THE CENTER OF THE LARGE HIGH BUILDS TO OUR NORTH. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...LOW STRATUS AND FOG IS MOST LIKELY TO OCCUR AT THE INLAND AIRPORTS: FLO AND LBT. THE LATEST HRRR MODEL (WHICH HAS DONE VERY WELL THE PAST SEVERAL NIGHTS) SHOWS LOW CEILINGS INTERMITTENTLY PRESENT AT THESE SITES BETWEEN 08-12Z. CLOSER TO THE COAST THE AIRMASS SHOULD SUPPORT THE DEVELOPMENT OF LOW MARITIME CUMULUS IN A MOIST ONSHORE FLOW BEGINNING 08-09Z...WITH TEMPORARY MVFR CEILINGS POSSIBLE. UPSTREAM SHOWERS IN THE CHARLESTON SC VICINITY MAY PASS NEAR THE COASTAL AIRPORTS AFTER 09Z. FOR DAYTIME WED...LOOKING AT MVFR POSSIBLE BRIEF IFR CONDITIONS FROM CONVECTION. THIS CONVECTION MAY DEVELOP ALONG A WEAK SFC TROF LIFTING NORTH ACROSS THE REGION...AND/OR ALONG THE LATE MORNING THRU EARLY EVENING INLAND PROGRESSING SEA BREEZE. FOR NOW...HAVE INDICATED VCTS AND WILL LET FOLLOWING SHIFTS UPDATE TO PINPOINT A MORE CONCRETE TIME FOR POSSIBLE MVFR/IFR CONVECTIVE CONDITIONS. BY THE MID TO LATE EVENING HRS...DIURNALLY DRIVEN CONVECTION SHOULD DISSIPATE. FORCING FOR CONVECTION FROM THE MESOSCALE INDUCED SEA BREEZE WILL DISSIPATE...AND THE SFC TROF SHOULD HAVE LIFTED NORTH OF THE FA. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 300 AM WEDNESDAY...HIGH PRESSURE NORTH OF BERMUDA WILL BE OUR CONTROLLING WEATHER SYSTEM THROUGH TONIGHT. TODAY`S SOUTH WINDS WILL VEER MORE SOUTHWESTERLY TONIGHT AS A COLD FRONT...CURRENTLY MOVING SE ACROSS ILLINOIS AND WISCONSIN...MOVES INTO WEST VIRGINIA AND KENTUCKY. AN UPPER LEVEL DISTURBANCE CURRENTLY MOVING NORTHEASTWARD ACROSS SOUTHERNMOST SOUTH CAROLINA MAY SPREAD ISOLATED SHOWERS ALONG THE NORTHEASTERN SOUTH CAROLINA COAST THIS MORNING...BUT LATEST HIGH- RES MODELS INDICATE COVERAGE OF STORMS WILL EXPAND ONCE THE DISTURBANCE REACHES SOUTHEASTERN NORTH CAROLINA LATE THIS MORNING AND EARLY THIS AFTERNOON. STEERING WINDS IN THE ATMOSPHERE WILL TEND TO PUSH STORMS NORTHEASTWARD AT 10 MPH...HOWEVER ASSUMING ENOUGH STORMS FORM COLLIDING OUTFLOW BOUNDARIES WILL ULTIMATELY DETERMINE WHERE STORMS MOVE. MARINERS IN THE CAPE FEAR AREA WILL WANT TO KEEP AN EYE ON THE SKY LATE THIS MORNING AND EARLY THIS AFTERNOON. SEAS CURRENTLY AROUND 2 FEET WILL BUILD CLOSER TO 3 FEET LATE THIS AFTERNOON AS WIND SPEEDS INCREASE WITH THE SEABREEZE. SW WINDS WILL INCREASE TO NEAR 15 KT TONIGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY... A PREFRONTAL TROUGH WILL BOOST WIND AND SEAS ON THURSDAY. WE ARE NOT ANTICIPATING HEADLINES OR ADVISORIES, BUT ITS BEEN FAIRLY QUIET SO THURSDAY WILL BE MORE UNSETTLED THAN THE PAST FEW DAYS WITH THE ADVENT OF SOME 4 FT SEAS. ON FRIDAY THIS BOUNDARY MOVES OFFSHORE AND WEAKENS IF NOT DISSIPATE ALTOGETHER. THE 20KT GUSTINESS SHOULD DROP OUT OF THE FORECAST AS WILL ANY 4 FT WAVES. A COLD FRONT WILL ALSO BE APPROACHING FROM THE NW ON FRIDAY BUT IT NOW LOOKS SLOWER THAN PREVIOUSLY FORECAST. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY... WITH THE SLOWER ARRIVAL OF COLD FRONT ON SATURDAY THE AREA MAY STAY IN AN INCREASED GRADIENT PRE-FRONTAL FLOW REGIME. AS SUCH WIND SPEEDS MAY NEED TO BE RE-EVALUATED AND RAISED ESPECIALLY AS SOME HIGHER MID LEVEL WINDS MAY BE IMPINGING UPON THE AREA. THE UPPER WAVE DRIVING THIS SYSTEM IS FAR FROM BEING SAMPLED BY THE UPPER AIR NETWORK HOWEVER AND SO NO LARGE CHANGES WILL BE MADE AT THIS TIME. SHOULD THINGS KEEP SLOWING DOWN THEN A SW WIND WILL REMAIN ON SUNDAY AS THE BOUNDARY EITHER STALLS ALONG THE COAST OR PERHAPS JUST INLAND. EITHER WAY THE STRONGER GRADIENT WILL HAVE PUSHED FURTHER OFFSHORE AND THE POSSIBILITY OF HIGHER WINDS AND SEAS THAN THE CURRENT FORECAST ALONG WITH IT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...TRA SHORT TERM...MBB LONG TERM...MBB AVIATION...DCH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
315 AM EDT WED SEP 9 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH FRIDAY AS WEAK LOW PRESSURE DEVELOPS TO THE WEST. LOW PRESSURE WILL PASS NORTH OF THE REGION SUNDAY PUSHING A COLD FRONT THROUGH THE AREA SUNDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 225 AM WED...UPR RDG TO THE S WILL CONT TO EXTEND N INTO THE REGION TODAY. WITH SFC HIGH OFFSHORE EXPECT S/SW LOW LVL FLOW WITH MOISTURE REMAINING QUITE HIGH...PWAT NEAR 2 INCHES. AS INSTAB DEVELOPS TODAY EXPECT SCT CONVECTION TO FORM ALONG SEA BRZ AND SHIFT INLAND WITH CHC POPS INLAND TO SLIGHT CHC CST. WITH DECENT AMOUNT OF SUN WILL SEE HIGHS NEAR 90 INLAND WITH MID/UPR 80S CST. && .SHORT TERM /TONIGHT/... AS OF 225 AM WED...SW FLOW ALOFT WILL INCREASE AS UPR TRF BEGINS TO APPROACH FROM THE W. MAY SEE JUST ENOUGH FORCING FROM THIS APPROACHING TRF TO KEEP ISOLD CONVECTION GOING OVERNIGHT...WITH BEST CVRG INLAND EARLY SHIFTING TOWARD CST LATE. WILL BE A VERY WARM NIGHT WITH SW LOW LVL FLOW...LOWS 70 TO 75 INLAND AND MID/UPR 70S BEACHES. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 3 AM WEDNESDAY...SUMMERLIKE PATTERN THROUGH THE FIRST PART OF THE LONG TERM PERIOD WITH SCATTERED SHOWERS AND THUNDERSTORMS, THEN A BETTER CHANCE OF PRECIP LATE IN THE WEEK, FOLLOWED BY A STRONG COLD FRONTAL PASSAGE AND COOLER/DRIER CONDITIONS BY EARLY NEXT WEEK. THURSDAY THROUGH FRIDAY...LARGE SCALE TROUGH ACROSS THE NORTHERN TIER OF THE CONUS WILL MIGRATE EASTWARD DURING THE PERIOD, WHILE UPPER RIDGE AMPLIFIES ACROSS THE INTERMOUNTAIN WEST. THIS WILL INDUCE STRONG DIGGING SHORTWAVE TROUGH ACROSS THE EASTERN US/OHIO VALLEY BY THE WEEKEND. AHEAD OF THIS SYSTEM IN RESPONSE, DEEP LAYER SOUTHWESTERLY FLOW WILL INDUCE VERY WARM AND HUMID CONDITIONS ACROSS EASTERN NC. WEAK SURFACE FRONT WILL SLOWLY MOVE THROUGH THE GREAT LAKES AREA, SOUTHEAST INTO THE WESTERN SLOPES OF THE APPALACHIAN MOUNTAINS ON THURSDAY. SLIGHTLY BETTER CHANCES FOR ORGANIZED PRECIP AS MOISTURE CONVERGENCE INCREASES OVER THE SOUTHEAST CONUS WITH NEARLY UNIDIRECTIONAL SW FLOW OVER EASTERN NC. MAINTAINED HIGH CHANCE POPS THURSDAY THROUGH FRIDAY FOR INLAND ZONES DUE TO HIGH PWATS AND SHORTWAVE ENERGY ROTATING AROUND STRONGER SHORTWAVE TO THE NORTHWEST. BULK OF UPPER LEVEL SUPPORT WILL REMAIN NORTH OF THE REGION SO SEVERE THREAT WILL BE MINIMAL. CONDITIONS WILL CONTINUE TO BE VERY MUGGY AND ABOVE CLIMO WITH HIGHS 85-90 AND LOWS IN THE 70S. THIS WEEKEND...MULTI-MODEL GUIDANCE HAS SHIFTED INTO BETTER AGREEMENT REGARDING TO EVOLUTION OF THE DIGGING STRONG SHORTWAVE THIS WEEKEND. 00Z GFS/GEM NOW VERY SIMILAR TO 00Z/PREVIOUS RUNS OF THE ECMWF, THEREFORE WILL CONTINUE MUCH OF THE PREVIOUS FORECAST THOUGH WITH GREATER CONFIDENCE IN EXPECTED SENSIBLE WX THIS WEEKEND. THE REGION WILL REMAIN IN THE WARM SECTOR WITH GOOD CHANCES OF SHOWERS AND STORMS ON SATURDAY. LATEST OPERATIONAL RUNS INDICATE A STRONG SHORTWAVE MAY ALSO CROSS THE REGION SATURDAY AFTERNOON, COINCIDENT WITH PEAK HEATING, THOUGH CLOUDS/PRECIP MAY INHIBIT MAXIMUM INSOLATION THEREBY LIMITING INSTABILITY SOMEWHAT. INCREASED POPS TO LIKELY FOR INLAND SECTIONS SATURDAY, TRANSLATING TO LIKELIES ALONG THE COAST SATURDAY NIGHT AS BEST CONVERGENCE AND MOISTURE SHIFTS OFFSHORE. INCREASING MID AND UPPER SW FLOW, ALONG WITH SHORTWAVE IN MEAN SW FLOW, COULD BRING A THREAT FOR SEVERE THUNDERSTORMS AS DEEP LAYER SHEAR INCREASES. THE LIMITING FACTOR FOR SEVERE THREAT WILL BE AMOUNT OF INSTABILITY. FOR SUNDAY, MORE QUESTIONABLE ON HOW QUICKLY SYSTEM EXITS THE EASTERN CONUS WITH A FASTER FRONTAL PASSAGE SOLUTION BRINGING DRIER AND COOLER CONDITIONS AND A SLOWER SCENARIO KEEPING SHOWER CHANCES THROUGH THE DAY. TRENDED POPS LOWER SUNDAY NIGHT INTO EARLY MONDAY FROM WEST TO EAST AS GUIDANCE HAS MOVED INTO BETTER AGREEMENT. MONDAY AND TUESDAY...HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE REGION MONDAY AND TUESDAY. MONDAY SHOULD BRING A RETURN TO COOLER AND MUCH DRIER CONDITIONS WITH HIGHS IN THE 80-85 RANGE AND LOWS 60-65 INLAND TO 65-70 BEACHES. DEWPOINTS WILL BE DOWN INTO THE 50S BRINGING FIRST EARLY TOUCH OF FALL TO THE REGION UNDER MOSTLY SUNNY SKIES. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 225 AM WED...MCLR SKIES...LIGHT WINDS AND HIGH LOW LVL MOISTURE ALL WOULD SEEM FAVORABLE FOR SOME FOG/ST TO DEVELOP THRU DAYBREAK. HIGH RES NARRE AND HRRR SHOW LITTLE TO NO IFR OVERNIGHT SO NOT REAL CONFIDENT HOW MUCH WILL FORM WITH LIGHT SSW LOW LVL FLOW. FOR NOW WILL SHOW PERIOD OF MAINLY IFR LATE. WHATEVER FOG OR ST DEVELOPS SHLD LIFT FAIRLY QUICKLY IN THE MORN WITH RETURN TO VFR. SCT SHRA/TSRA WILL DEVELOP TODAY WITH HEATING...VERY BRIEF REDUCTIONS IN CIGS/VSBYS POSS. ISOLD CONVECTION COULD CONT TONIGHT HOWEVER GIVEN UNCERTAIN CVRG WILL NOT MENTION IN TAFS. SLIGHTLY STRONGER SW LOW LVL FLOW AND DECENT AMOUNT OF CLOUDS SHLD LIMIT THREAT FOR LATE NIGHT FOG/ST. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 310 AM WEDNESDAY...GENERALLY VFR THROUGH THE PERIOD, THOUGH OCCASIONAL FOG POSSIBLE EACH NIGHT/EARLY MORNING DUE TO LIGHT WINDS AND HIGH BOUNDARY LAYER MOISTURE. TEMPO RESTRICTIONS POSSIBLE EACH AFTERNOON DUE TO SCATTERED SHOWERS/THUNDERSTORMS. BETTER CHANCE FOR MORE WIDESPREAD SHOWERS/THUNDERSTORMS LATE WEEK INTO FIRST PART OF THE WEEKEND AHEAD OF A STRONG COLD FRONT. THE FRONT WILL CROSS EASTERN NC LATE SUNDAY INTO SUNDAY NIGHT. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 225 AM WED...HIGH PRES OFFSHORE AND DEVELOPING TRF TO THE W WILL LEAD TO MAINLY SW FLOW THRU THE PERIOD. GRDNT REMAINS FAIRLY LOOSE TODAY WITH SPEEDS MAINLY 8 TO 12 KTS. SPEEDS WILL INCREASE A BIT TONIGHT TO 10 TO 15 KTS. SEAS OF 2 TO 3 FEET TODAY WILL BUILD A BIT WITH 3 TO 4 FEET OUTER WATERS LATER TONIGHT. LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 315 AM WEDNESDAY...A TIGHTENING SOUTHWESTERLY PRESSURE GRADIENT WILL CREATE POOR BOATING CONDITIONS THURSDAY THROUGH THE WEEKEND. WINDS WILL BE SW 5-15 KT THROUGH EARLY THURSDAY, THEN INCREASE TO 10-20 KT LATER THURSDAY, HIGHEST ON THE OUTER PORTIONS OF THE COASTAL WATERS. SEAS WILL GENERALLY BE 3 FEET OR LESS THROUGH EARLY THURSDAY, THEN BUILD 3-5 FT THURSDAY INTO FRIDAY IN RESPONSE TO STRENGTHENING SOUTHWESTERLY WINDS. STRONG COLD FRONT WILL APPROACH BY LATE WEEKEND AND CROSS THE EASTERN NC WATERS LATE SUNDAY NIGHT INTO MONDAY. FORECAST CONFIDENCE HAS INCREASED WITH REGARDS TO WEEKEND SCENARIO DUE TO MUCH BETTER AGREEMENT AMONGST MEDIUM/LONG RANGE GUIDANCE. CONDITIONS COULD REACH MARGINAL SCA CRITERIA WITH WIND GUSTS TO 25 KT AND 6 FT SEAS LATE SATURDAY INTO EARLY SUNDAY AHEAD OF THE STRONG COLD FRONT. WAVEWATCH AND LOCAL SWAN/NWPS IN GOOD AGREEMENT THROUGH THE MEDIUM RANGE, THEN WAVEWATCH APPEARED REASONABLE FOR THE EXTENDED SEAS AS ITS GFS- BASED WINDS ARE BETTER IN LINE WITH FORECAST WINDS. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RF NEAR TERM...RF SHORT TERM...RF LONG TERM...DAG/TL AVIATION...RF/DAG MARINE...RF/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
236 AM EDT WED SEP 9 2015 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH FRIDAY AS WEAK LOW PRESSURE DEVELOPS TO THE WEST. LOW PRESSURE WILL PASS NORTH OF THE REGION SUNDAY PUSHING A COLD FRONT THROUGH THE AREA SUNDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 225 AM WED...UPR RDG TO THE S WILL CONT TO EXTEND N INTO THE REGION TODAY. WITH SFC HIGH OFFSHORE EXPECT S/SW LOW LVL FLOW WITH MOISTURE REMAINING QUITE HIGH...PWAT NEAR 2 INCHES. AS INSTAB DEVELOPS TODAY EXPECT SCT CONVECTION TO FORM ALONG SEA BRZ AND SHIFT INLAND WITH CHC POPS INLAND TO SLIGHT CHC CST. WITH DECENT AMOUNT OF SUN WILL SEE HIGHS NEAR 90 INLAND WITH MID/UPR 80S CST. && .SHORT TERM /TONIGHT/... AS OF 225 AM WED...SW FLOW ALOFT WILL INCREASE AS UPR TRF BEGINS TO APPROACH FROM THE W. MAY SEE JUST ENOUGH FORCING FROM THIS APPROACHING TRF TO KEEP ISOLD CONVECTION GOING OVERNIGHT...WITH BEST CVRG INLAND EARLY SHIFTING TOWARD CST LATE. WILL BE A VERY WARM NIGHT WITH SW LOW LVL FLOW...LOWS 70 TO 75 INLAND AND MID/UPR 70S BEACHES. && .LONG TERM /THURSDAY THROUGH TUESDAY/... AS OF 315 PM TUESDAY...SUMMERLIKE PATTERN THROUGH THE FIRST PART OF THE LONG TERM PERIOD WITH SCATTERED SHOWERS AND THUNDERSTORMS, THEN A BETTER CHANCE OF PRECIP LATE IN THE WEEK, FOLLOWED BY A POSSIBLE STRONG COLD FRONTAL PASSAGE AND COOLER/DRIER CONDITIONS BY LATE WEEKEND/EARLY NEXT WEEK. THURSDAY THROUGH FRIDAY...LARGE SCALE TROUGH ACROSS THE NORTHERN TIER OF THE CONUS WILL MIGRATE EASTWARD DURING THE PERIOD, WHILE UPR RIDGE AMPLIFIES ACROSS THE INTERMOUNTAIN WEST. THIS WILL INDUCE STRONG DIGGING SHORTWAVE TROUGH ACROSS THE EASTERN US/OHIO VALLEY BY THE WEEKEND. AHEAD OF THIS SYSTEM IN RESPONSE...DEEP LAYER SWRLY FLOW WILL PUMP IN VERY WARM AND HUMID CONDITIONS. WEAK SURFACE FRONT WILL SLOWLY MOVE THROUGH THE GREAT LAKES AREA, SOUTHEAST INTO THE WESTERN SLOPES OF THE APPALACHIAN MOUNTAINS ON THURSDAY. SLIGHTLY BETTER CHANCES FOR ORGANIZED PRECIP AS MOISTURE CONVERGENCE INCREASES OVER THE SOUTHEAST CONUS WITH NEARLY UNIDIRECTIONAL SW FLOW OVER EASTERN NC. MAINTAINED HIGH CHANCE POPS THURSDAY THROUGH FRIDAY FOR INLAND ZONES DUE TO HIGH PWATS AND PIECES OF SHORTWAVE ENERGY ROTATING AROUND STRONGER SHORTWAVE TO THE NORTH AND WEST. THE BULK OF UPPER LEVEL SUPPORT WILL REMAIN NORTH OF THE REGION SO SEVERE THREAT WILL BE MINIMAL. CONDITIONS WILL CONTINUE TO BE VERY MUGGY AND ABOVE CLIMO WITH HIGHS 85-90 AND LOWS IN THE 70S. THIS WEEKEND...THERE ARE STILL SOME DIFFERENCES AMONGST MODEL SUITE IN REGARDS TO EVOLUTION OF THE DIGGING STRONG SHORTWAVE THIS WEEKEND. HAVE CONTINUED TO FOLLOW MORE CLOSELY TO WPC/ECMWF SOLN. A LOOK AT THE ENSEMBLE MEAN HEIGHTS INDICATE THE NCEP/ECM ENSEMBLE MEAN ALONG WITH ECMWF/GEM GLOBAL HAVE FAIRLY UNANIMOUS SUPPORT WITH HANDLING UP UPR LOW/SHORTWAVE POSITIONING ACROSS THE OHIO VALLEY...WHILE DETERMINISTIC GFS STILL A BIT OF AN OUTLIER. THIS WILL KEEP AREA IN THE WARM SECTOR WITH GOOD CHANCES OF SHOWERS AND STORMS ON SATURDAY. WILL RAISE POPS A BIT...INTO THE 40-50 PERCENT RANGE. INCREASING MID AND UPPER SW FLOW COULD BRING A THREAT FOR SEVERE STORMS AS DEEP LAYER SHEAR INCREASES...WITH SEVERE THREAT BEING DEPENDENT ON AMOUNT OF AVAILABLE INSTABILITY. FOR SUNDAY, MORE QUESTIONABLE ON HOW QUICKLY SYSTEM EXITS THE EASTERN CONUS WITH A FASTER FRONTAL PASSAGE SOLUTION BRINGING DRIER AND COOLER CONDITIONS AND A SLOWER SCENARIO KEEPING SHOWER CHANCES THROUGH THE DAY. FOR NOW WILL MAINTAIN THE 30 POPS. MONDAY AND TUESDAY...MONDAY SHOULD BRING A RETURN TO COOLER AND MUCH DRIER CONDITIONS WITH HIGHS IN THE 80-85 RANGE AND LOWS 60-65 INLAND TO 65-70 BEACHES. TD`S WILL BE DOWN INTO THE 50S BRINGING FIRST EARLY TOUCH OF FALL TO THE REGION UNDER MOSTLY SUNNY SKIES. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH TONIGHT/... AS OF 225 AM WED...MCLR SKIES...LIGHT WINDS AND HIGH LOW LVL MOISTURE ALL WOULD SEEM FAVORABLE FOR SOME FOG/ST TO DEVELOP THRU DAYBREAK. HIGH RES NARRE AND HRRR SHOW LITTLE TO NO IFR OVERNIGHT SO NOT REAL CONFIDENT HOW MUCH WILL FORM WITH LIGHT SSW LOW LVL FLOW. FOR NOW WILL SHOW PERIOD OF MAINLY IFR LATE. WHATEVER FOG OR ST DEVELOPS SHLD LIFT FAIRLY QUICKLY IN THE MORN WITH RETURN TO VFR. SCT SHRA/TSRA WILL DEVELOP TODAY WITH HEATING...VERY BRIEF REDUCTIONS IN CIGS/VSBYS POSS. ISOLD CONVECTION COULD CONT TONIGHT HOWEVER GIVEN UNCERTAIN CVRG WILL NOT MENTION IN TAFS. SLIGHTLY STRONGER SW LOW LVL FLOW AND DECENT AMOUNT OF CLOUDS SHLD LIMIT THREAT FOR LATE NIGHT FOG/ST. LONG TERM /THU THROUGH SUNDAY/... AS OF 315 PM TUESDAY...GENERALLY VFR THROUGH THE PERIOD, THOUGH OCCASIONAL FOG POSSIBLE EACH NIGHT/EARLY MORNING DUE TO CALM WINDS AND HIGH BOUNDARY LAYER MOISTURE. TEMPO RESTRICTIONS POSSIBLE EACH AFTERNOON DUE TO SCATTERED SHOWERS/THUNDERSTORMS. BETTER CHANCE FOR MORE WIDESPREAD SHOWERS/THUNDERSTORMS LATE WEEK INTO FIRST PART OF THE WEEKEND AHEAD OF A STRONG COLD FRONT. WINDS WILL INC OUT OF THE SW ON THUR AND BECOME GUSTY 12-16 KT. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 225 AM WED...HIGH PRES OFFSHORE AND DEVELOPING TRF TO THE W WILL LEAD TO MAINLY SW FLOW THRU THE PERIOD. GRDNT REMAINS FAIRLY LOOSE TODAY WITH SPEEDS MAINLY 8 TO 12 KTS. SPEEDS WILL INCREASE A BIT TONIGHT TO 10 TO 15 KTS. SEAS OF 2 TO 3 FEET TODAY WILL BUILD A BIT WITH 3 TO 4 FEET OUTER WTRS LATER TONIGHT. LONG TERM /THU THROUGH SUNDAY/... AS OF 315 PM TUESDAY...A TIGHTENING SOUTHWESTERLY PRESSURE GRADIENT WILL CREATE MARGINAL CONDITIONS BY THURSDAY THROUGH THE WEEKEND. WINDS WILL BE SW 5-15 KT THROUGH EARLY THURSDAY, THEN INCREASE TO 10-20 KT LATER THURSDAY, HIGHEST ON THE OUTER PORTIONS OF THE COASTAL WATERS. SEAS WILL GENERALLY BE 3 FEET OR LESS THROUGH EARLY THURSDAY, THEN BUILD 3-5 FT THURSDAY INTO FRIDAY IN RESPONSE TO STRENGTHENING SOUTHWESTERLY WINDS. STRONG COLD FRONT WILL APPROACH BY LATE WEEKEND, THOUGH FORECAST CONFIDENCE STILL RELATIVELY LOW AT THIS TIME DUE TO DISAGREEMENT AMONGST GUIDANCE IN THE FAR EXTENDED PERIOD. CONTINUED AROUND A FOOT HIGHER THAN 12Z WAVEWATCH GUIDANCE AS ITS GFS-BASED WINDS WERE LOWER THAN FCST 15-20 KT SUSTAINED WINDS. CONDITIONS COULD REACH MARGINAL SCA CRITERIA WITH 6 FOOT SEAS FOR A TIME LATE SATURDAY INTO EARLY SUNDAY AHEAD OF THE STRONG COLD FRONT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RF NEAR TERM...RF SHORT TERM...RF LONG TERM...TL/DAG AVIATION...RF/TL MARINE...RF/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
150 AM EDT WED SEP 9 2015 .SYNOPSIS... SUMMERTIME HEAT AND HUMIDITY WILL RETURN AS HIGH PRESSURE CONTINUES OVER THE REGION THROUGH THURSDAY. A COLD FRONT WILL APPROACH FROM THE WEST THURSDAY AFTERNOON AND THEN STALL ALONG THE COAST WHICH WILL INCREASE THE RISK FOR THUNDERSTORMS INTO THE WEEKEND. THE FRONT WILL SLOWLY DISSIPATE EARLY NEXT WEEK AS HIGH PRESSURE RETURNS. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 100 AM WEDNESDAY...SHOWERS ARE DEVELOPING UPSTREAM IN THE CHARLESTON VICINITY MUCH LIKE THE 02Z HRRR INDICATES. ADVECTION OF THIS CONVECTION ACROSS THE SANTEE RIVER INTO NE SOUTH CAROLINA IS POSSIBLE AFTER 2-3 AM. OTHERWISE SKIES ARE CURRENTLY CLEAR TO PARTLY CLOUDY WITH PATCHY FOG ACROSS THE AREA. UPDATES WITH THIS FINAL NEAR-TERM UPDATE OF THE NIGHT INCLUDE TWEAKS TO SKY...WIND...AND DEWPOINT. DISCUSSION FROM 1000 PM FOLLOWS... THE HIGH RESOLUTION MODELS CONTINUE TO SHOW SOME UPTICK IN CONVECTION AS DAYBREAK APPROACHES. WEAK LOW PRESSURE ACROSS GEORGIA DOES LIFT N ACROSS SOUTH CAROLINA OVERNIGHT. GIVEN HOW QUICKLY CONVECTION HAS DISSIPATED THIS EVE...WILL CONFINE MENTIONABLE POPS TO THE CLIMATOLOGICALLY FAVORED WARM OCEAN WATERS AND ADJACENT IMMEDIATE COAST WITH THE APPROACH OF DAYBREAK WHERE SOME WEAK LOW-LEVEL CONVERGENCE WAS NOTED. PROFILES DO NOT SUPPORT DENSE FOG OVERNIGHT. THE WEDGE WHICH HAD BEEN IN PLACE LAST NIGHT...HAS BROKEN DOWN AND WARM SOUTHERLY WINDS HAVE RETURNED. WINDS ABOVE THE BOUNDARY LAYER WILL BE IN THE 15 TO 20 KT RANGE FOR MOST OF THE OVERNIGHT. CONSIDERABLE CONVECTIVE CLOUD DEBRIS SHOULD CONTINUE TO FILTER ACROSS THE AREA FROM THE SOUTH. GIVEN THE LACK OF SIGNALS SUPPORTING SIGNIFICANT FOG...WILL OPT TO LEAVE FOG OUT OF THE FORECAST. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...UPPER LEVEL HIGH PRESSURE CENTERED OVER THE FLORIDA STRAITS WILL BRING IN VERY WARM 500 MB TEMPERATURES OF - 5.5C. THIS COMBINED WITH PRECIPITABLE WATER OF AROUND 2 INCHES WILL PROVIDE ABOVE NORMAL TEMPERATURES AND SCATTERED DIURNAL CONVECTION FOR WEDNESDAY. HIGHS ARE EXPECTED TO REACH INTO THE LOWER 90S INLAND AND NEAR NINETY AT THE BEACHES. ALOFT THE SOUTHERLY FLOW WILL SLOWLY VEER TO THE SOUTHWEST AHEAD OF COLD FRONT THAT WILL APPROACH THE REGION ON THURSDAY BEFORE STALLING INTO THE AREA OVERNIGHT. LITTLE TO NO STRONG SYNOPTIC FORCING BOTH WEDNESDAY AND THURSDAY SO MESOSCALE LIFT WILL BE THE MAIN TRIGGER FOR THE SCATTERED LOCATION EACH DAY. WITH THE FRONTAL BOUNDARY STILL LINGERING TO THE WEST ON THURSDAY HIGHS ARE EXPECTED TO THE LOWER 90S MOST LOCALES. LOW TEMPERATURE BOTH DAYS ARE EXPECTED TO FALL INTO THE LOWER TO MIDDLE 70S. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... AS OF 300 PM TUESDAY...THE EXTENDED FORECAST WILL BE DOMINATED BY SIGNIFICANT AMPLITUDE AT THE MID LEVELS AT LEAST THROUGH THE WEEKEND. A POTENT TROUGH WILL DEEPEN FURTHER AND POSSIBLY EVEN CUTOFF AS ADVERTISED BY SOME GUIDANCE BUT CERTAINLY DEEPEN THROUGH SUNDAY BEFORE FINALLY GETTING KICKED BY AN UPSTREAM SYSTEM OPENING UP AND MOVING OFF IN THE WESTERLIES. AT THE SURFACE A FRONT WILL BE ESSENTIALLY STATIONARY OVER THE CWA THROUGH MONDAY MORNING FINALLY PUSHING THROUGH AS THE TROUGH LIFTS OUT. WITH THE TROUGH IN THE MIDWEST...THE EASTERN CAROLINAS WILL BE UNDER A DEEP AND MOIST SOUTHWEST FLOW THUS SHOWERS AND THUNDERSTORMS ARE FAIR GAME JUST ABOUT ANYTIME. IT APPEARS THE BEST SHOT AT LEAST WITH THE LATEST GUIDANCE APPEARS TO BE SATURDAY INTO EARLY SUNDAY WHEN THE MOISTURE AND LOW LEVEL FORCING TEAM UP WITH A DECENT 300MB JET. TEMPERATURE FORECAST REMAINS BASICALLY UNCHANGED WITH LOW DIURNAL RANGES EARLY WITH A COOL DOWN AND HIGHER SPREAD MONDAY AND TUESDAY. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...LOW STRATUS AND FOG IS MOST LIKELY TO OCCUR AT THE INLAND AIRPORTS: FLO AND LBT. THE LATEST HRRR MODEL (WHICH HAS DONE VERY WELL THE PAST SEVERAL NIGHTS) SHOWS LOW CEILINGS INTERMITTENTLY PRESENT AT THESE SITES BETWEEN 08-12Z. CLOSER TO THE COAST THE AIRMASS SHOULD SUPPORT THE DEVELOPMENT OF LOW MARITIME CUMULUS IN A MOIST ONSHORE FLOW BEGINNING 08-09Z...WITH TEMPORARY MVFR CEILINGS POSSIBLE. UPSTREAM SHOWERS IN THE CHARLESTON SC VICINITY MAY PASS NEAR THE COASTAL AIRPORTS AFTER 09Z. FOR DAYTIME WED...LOOKING AT MVFR POSSIBLE BRIEF IFR CONDITIONS FROM CONVECTION. THIS CONVECTION MAY DEVELOP ALONG A WEAK SFC TROF LIFTING NORTH ACROSS THE REGION...AND/OR ALONG THE LATE MORNING THRU EARLY EVENING INLAND PROGRESSING SEA BREEZE. FOR NOW...HAVE INDICATED VCTS AND WILL LET FOLLOWING SHIFTS UPDATE TO PINPOINT A MORE CONCRETE TIME FOR POSSIBLE MVFR/IFR CONVECTIVE CONDITIONS. BY THE MID TO LATE EVENING HRS...DIURNALLY DRIVEN CONVECTION SHOULD DISSIPATE. FORCING FOR CONVECTION FROM THE MESOSCALE INDUCED SEA BREEZE WILL DISSIPATE...AND THE SFC TROF SHOULD HAVE LIFTED NORTH OF THE FA. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 100 AM WEDNESDAY...CURRENTLY OBSERVATIONS INDICATE WINDS LESS THAN 10 KNOTS EXCEPT RIGHT UP ON THE BEACHES WHERE SOME RECENT GUSTS HAVE BEEN IN THE 12-14 KNOT RANGE. MINOR TWEAKS ARE ALL THAT ARE NEEDED TO THE FORECAST. DISCUSSION FROM 1000 PM FOLLOWS... SOUTHERLY WINDS WILL REMAIN IN PLACE OVERNIGHT AHEAD OF AN INLAND TROUGH. THIS SHOULD KEEP WINDS IN THE 10 TO 15 KT RANGE. SEAS OF MAINLY 2 FT SHOULD BUILD A HALF FOOT TO A FOOT THROUGH WED MORNING. CONVECTION IS EXPECTED TO DEVELOP ACROSS THE WATERS AND OFFSHORE DURING THE LATE NIGHT AND MORNING HOURS OF WED. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 300 PM TUESDAY...HIGH PRESSURE DURING THE EARLY PORTION OF THIS PERIOD WILL SLOWLY WEAKEN AS A FRONTAL BOUNDARY MOVES INTO THE CENTRAL PORTIONS OF THE CAROLINAS BY THURSDAY NIGHT. WINDS WILL BECOME MORE SOUTHWESTERLY WITH TIME AND A INCREASE IN WINDS OF 15 TO 20 KNOTS IS EXPECTED THURSDAY NIGHT. SEAS ARE EXPECTED TO SLOWLY BUILD INTO THE 3 TO 4 FT RANGE BY FRIDAY NIGHT WITH AN ISOLATED 5 FOOTER POSSIBLE. A SMALL CRAFT EXERCISE CAUTION IS POSSIBLE THURSDAY NIGHT. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 300 PM TUESDAY...WINDS WILL BE MOSTLY FROM THE SOUTHWEST FRIDAY AND SATURDAY AS A COLD FRONT GETS HUNG UP INLAND. WIND SPEEDS SEEM TO BE HIGHEST FRIDAY BEFORE THE FRONT WEAKENS AND IN THE 10-15 KNOT RANGE. SATURDAY WINDS SHOULD DIMINISH TO NEAR TEN KNOTS. TOUGH CALL ON WINDS FOR SUNDAY AS LOW PRESSURE IS PROGGED TO DEVELOP INLAND WHICH WILL TURN THE WINDS TO THE SOUTHEAST FOR A WHILE. SIGNIFICANT SEAS SHOULD END UP IN A 1-3 FOOT RANGE. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RJD NEAR TERM...RJD/TRA SHORT TERM...DRH LONG TERM...SHK AVIATION...DCH/TRA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1230 AM EDT WED SEP 9 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFFSHORE THROUGH MIDWEEK AS WEAK LOW PRESSURE DEVELOPS TO THE WEST. A STRONG COLD FRONT WILL APPROACH FROM THE WEST LATE IN THE WEEK AND CROSS THE AREA BY LATE THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1225 AM WED...NO SIGNIF CHANGES OVERNIGHT WITH MOST AREAS REMAINING DRY. DID ADD SLIGHT POP TOWARD DAYBREAK NEAR S CST WHERE MDLS SHOW SOME POSS OF SHRA/TSRA DEVELOPING. PREV DISC...PRECIPITATION HAS DISSIPATED ACROSS OUR CWA AND HAVE REMOVED ALL POPS FROM THE FORECAST OVERNIGHT. LATEST RUN OF THE 3KM HRRR AND RUC MODELS INDICATE NO ADDITIONAL PRECIPITATION OVER LAND AREAS OVERNIGHT. WITH HIGH LOW- LEVEL MOISTURE AND LIGHT WINDS...FOG IS A GOOD BET OVERNIGHT. NO CHANGES TO FORECAST TEMPERATURES WITH LOWS AROUND 70 INLAND TO MID 70S BEACHES. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TODAY/... AS OF 2 PM TUE...WEAK UPPER RIDGING OVER THE BAHAMAS/FLORIDA WITH LONG WAVE TROUGHING ACROSS THE UPPER PLAINS/MIDWEST WILL RESULT IN SOUTHWESTERLY FLOW ALOFT. S TO SW SFC SFC WINDS WILL RESULT IN WARM AND MUGGY CONDITIONS ALONG WITH ISOLATED TO SCATTERED DIURNAL SHOWERS AND THUNDERSTORMS...BEST CHANCES ALONG THE SEA BREEZE. COASTAL AREAS SHOULD REMAIN MOSTLY DRY AND THE SEVERE THREAT IS LOW DUE TO WEAK UPPER LEVEL SUPPORT. HIGHS WILL RANGE FROM NEAR 90 INLAND TO MID 80S BEACHES. && .LONG TERM /TONIGHT THROUGH TUESDAY/... AS OF 315 PM TUESDAY...SUMMERLIKE PATTERN THROUGH THE FIRST PART OF THE LONG TERM PERIOD WITH SCATTERED SHOWERS AND THUNDERSTORMS, THEN A BETTER CHANCE OF PRECIP LATE IN THE WEEK, FOLLOWED BY A POSSIBLE STRONG COLD FRONTAL PASSAGE AND COOLER/DRIER CONDITIONS BY LATE WEEKEND/EARLY NEXT WEEK. THURSDAY THROUGH FRIDAY...LARGE SCALE TROUGH ACROSS THE NORTHERN TIER OF THE CONUS WILL MIGRATE EASTWARD DURING THE PERIOD, WHILE UPR RIDGE AMPLIFIES ACROSS THE INTERMOUNTAIN WEST. THIS WILL INDUCE STRONG DIGGING SHORTWAVE TROUGH ACROSS THE EASTERN US/OHIO VALLEY BY THE WEEKEND. AHEAD OF THIS SYSTEM IN RESPONSE...DEEP LAYER SWRLY FLOW WILL PUMP IN VERY WARM AND HUMID CONDITIONS. WEAK SURFACE FRONT WILL SLOWLY MOVE THROUGH THE GREAT LAKES AREA, SOUTHEAST INTO THE WESTERN SLOPES OF THE APPALACHIAN MOUNTAINS ON THURSDAY. SLIGHTLY BETTER CHANCES FOR ORGANIZED PRECIP AS MOISTURE CONVERGENCE INCREASES OVER THE SOUTHEAST CONUS WITH NEARLY UNIDIRECTIONAL SW FLOW OVER EASTERN NC. MAINTAINED HIGH CHANCE POPS THURSDAY THROUGH FRIDAY FOR INLAND ZONES DUE TO HIGH PWATS AND PIECES OF SHORTWAVE ENERGY ROTATING AROUND STRONGER SHORTWAVE TO THE NORTH AND WEST. THE BULK OF UPPER LEVEL SUPPORT WILL REMAIN NORTH OF THE REGION SO SEVERE THREAT WILL BE MINIMAL. CONDITIONS WILL CONTINUE TO BE VERY MUGGY AND ABOVE CLIMO WITH HIGHS 85-90 AND LOWS IN THE 70S. THIS WEEKEND...THERE ARE STILL SOME DIFFERENCES AMONGST MODEL SUITE IN REGARDS TO EVOLUTION OF THE DIGGING STRONG SHORTWAVE THIS WEEKEND. HAVE CONTINUED TO FOLLOW MORE CLOSELY TO WPC/ECMWF SOLN. A LOOK AT THE ENSEMBLE MEAN HEIGHTS INDICATE THE NCEP/ECM ENSEMBLE MEAN ALONG WITH ECMWF/GEM GLOBAL HAVE FAIRLY UNANIMOUS SUPPORT WITH HANDLING UP UPR LOW/SHORTWAVE POSITIONING ACROSS THE OHIO VALLEY...WHILE DETERMINISTIC GFS STILL A BIT OF AN OUTLIER. THIS WILL KEEP AREA IN THE WARM SECTOR WITH GOOD CHANCES OF SHOWERS AND STORMS ON SATURDAY. WILL RAISE POPS A BIT...INTO THE 40-50 PERCENT RANGE. INCREASING MID AND UPPER SW FLOW COULD BRING A THREAT FOR SEVERE STORMS AS DEEP LAYER SHEAR INCREASES...WITH SEVERE THREAT BEING DEPENDENT ON AMOUNT OF AVAILABLE INSTABILITY. FOR SUNDAY, MORE QUESTIONABLE ON HOW QUICKLY SYSTEM EXITS THE EASTERN CONUS WITH A FASTER FRONTAL PASSAGE SOLUTION BRINGING DRIER AND COOLER CONDITIONS AND A SLOWER SCENARIO KEEPING SHOWER CHANCES THROUGH THE DAY. FOR NOW WILL MAINTAIN THE 30 POPS. MONDAY AND TUESDAY...MONDAY SHOULD BRING A RETURN TO COOLER AND MUCH DRIER CONDITIONS WITH HIGHS IN THE 80-85 RANGE AND LOWS 60-65 INLAND TO 65-70 BEACHES. TD`S WILL BE DOWN INTO THE 50S BRINGING FIRST EARLY TOUCH OF FALL TO THE REGION UNDER MOSTLY SUNNY SKIES. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /THROUGH 00Z THURSDAY/... AS OF 1225 AM WED...MCLR SKIES...LIGHT WINDS AND HIGH LOW LVL MOISTURE ALL WOULD SEEM FAVORABLE FOR SOME FOG/ST TO DEVELOP. HIGH RES NARRE AND HRRR SHOW LITTLE TO NO IFR OVERNIGHT SO NOT REAL CONFIDENT HOW MUCH WILL FORM WITH LIGHT SSW LOW LVL FLOW. FOR NOW WILL SHOW PERIOD OF IFR INLAND AND MVFR CST LATER TONIGHT. WHATEVER FOG OR ST DEVELOPS SHLD LIFT FAIRLY QUICKLY IN THE MORN WITH RETURN TO VFR. SCT SHRA/TSRA WILL DEVELOP WED WITH HEATING WITH VERY BRIEF REDUCTIONS IN CIGS/VSBYS POSS. LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/ AS OF 315 PM TUESDAY...GENERALLY VFR THROUGH THE PERIOD, THOUGH OCCASIONAL FOG POSSIBLE EACH NIGHT/EARLY MORNING DUE TO CALM WINDS AND HIGH BOUNDARY LAYER MOISTURE. TEMPO RESTRICTIONS POSSIBLE EACH AFTERNOON DUE TO SCATTERED SHOWERS/THUNDERSTORMS. BETTER CHANCE FOR MORE WIDESPREAD SHOWERS/THUNDERSTORMS LATE WEEK INTO FIRST PART OF THE WEEKEND AHEAD OF A STRONG COLD FRONT. WINDS WILL INC OUT OF THE SW ON THUR AND BECOME GUSTY 12-16 KT. && .MARINE... SHORT TERM /TONIGHT THROUGH WEDNESDAY/... AS OF 1225 AM WED...FCST LOOKS GOOD WITH NO SIGNIF CHANGES PLANNED. PREV DISC...MINOR ADJUSTMENTS TO WIND DIRECTION AS WINDS ARE GENERALLY SE/S AT SPEEDS OF 10 KNOTS OR LESS WITH SEAS GENERALLY 2 TO 3 FEET WITH SOME LONGER PERIOD SWELL ENERGY. NO CHANGES TO THIS ARE EXPECTED OVERNIGHT. WINDS VEER TO MORE SW BY EARLY WEDNESDAY AS AXIS OF HIGH PRESSURE RIDGE SHIFTS OFFSHORE. SEAS CONTINUE AT 2 TO 3 FEET FOR WEDNESDAY. LONG TERM /WED NIGHT THROUGH SUNDAY/ AS OF 315 PM TUESDAY...GENERALLY GOOD BOATING CONDITIONS CONTINUE THROUGH WEDNESDAY NIGHT, THEN A TIGHTENING SOUTHWESTERLY PRESSURE GRADIENT WILL CREATE MARGINAL CONDITIONS BY THURSDAY THROUGH THE WEEKEND. WINDS WILL BE SW 5-15 KT WEDNESDAY NIGHT THROUGH EARLY THURSDAY, THEN INCREASE TO 10-20 KT LATER THURSDAY, HIGHEST ON THE OUTER PORTIONS OF THE COASTAL WATERS. SEAS WILL GENERALLY BE 3 FEET OR LESS THROUGH EARLY THURSDAY, THEN BUILD 3-5 FT THURSDAY INTO FRIDAY IN RESPONSE TO STRENGTHENING SOUTHWESTERLY WINDS. STRONG COLD FRONT WILL APPROACH BY LATE WEEKEND, THOUGH FORECAST CONFIDENCE STILL RELATIVELY LOW AT THIS TIME DUE TO DISAGREEMENT AMONGST GUIDANCE IN THE FAR EXTENDED PERIOD. CONTINUED AROUND A FOOT HIGHER THAN 12Z WAVEWATCH GUIDANCE AS ITS GFS-BASED WINDS WERE LOWER THAN FCST 15-20 KT SUSTAINED WINDS. CONDITIONS COULD REACH MARGINAL SCA CRITERIA WITH 6 FOOT SEAS FOR A TIME LATE SATURDAY INTO EARLY SUNDAY AHEAD OF THE STRONG COLD FRONT. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JAC NEAR TERM...RF/CTC SHORT TERM...JAC LONG TERM...DAG/TL AVIATION...RF/TL MARINE...RF/CTC/TL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1250 AM CDT WED SEP 9 2015 .UPDATE... ISSUED AT 1250 AM CDT WED SEP 9 2015 COLD FRONTAL BOUNDARY WILL CONTINUE TO MOVE SLOWLY SOUTH INTO THE NORTHERN PLAINS LATE TONIGHT THROUGH WEDNESDAY. COMBINED WITH MID LEVEL EMBEDDED S/WV TROUGHS AND UPPER LEVEL JET DYNAMICS...CLOUD COVER AND CHANCES FOR LIGHT SHOWERS CAN BE EXPECTED EARLY THIS MORNING THROUGH AT LEAST WEDNESDAY NIGHT STARTING NORTH AND SLOWLY EXPANDING SOUTHWARD ALONG THE FROPA. HAVE A SLIGHT CHANCE OF SHOWERS NOW STARTING IN THE NORTHWEST AND EXPANDING EAST AND SLIGHTLY SOUTH WITH TIME THROUGH THE AM HOURS. JET ENTRANCE DYNAMICS TRIGGERING AN AREA OF LIGHT SHOWERS NOW MOVING INTO NORTHEASTERN MONTANA. WITH CLOUD BASES AROUND 10K FT AGL IN SOUTHERN SASKATCHEWAN...UNSURE HOW MUCH OF THE RADAR RETURNS ARE ACTUALLY REACHING THE GROUND. WILL INCREASE POPS ACCORDINGLY IF WE START MEASURING. UPDATE ISSUED AT 848 PM CDT TUE SEP 8 2015 AT 830 PM CDT...A COLD FRONTAL BOUNDARY EXTENDED ACROSS SOUTHWEST SASKATCHEWAN. THE FRONT WILL SLOWLY SLIDE SOUTHEAST TONIGHT AND WEDNESDAY WITH ONLY A SLOW SOUTHWARD MOVING COMPONENT AS IT NEARLY ALIGNS WITH THE FLOW ALOFT. LATEST HRRR MODEL RUNS SHOW SOME SCATTERED SHOWERS ACROSS THE NORTHWEST AFTER 09Z TONIGHT AND NORTH CENTRAL AFTER 12Z WEDNESDAY. ADDED MORE SLIGHT CHANCE AREA TO THE NORTHWEST IN CONCERT WITH THE HRRR AFTER 09Z. OTHERWISE CURRENT FORECAST LOOKS GOOD. UPDATE ISSUED AT 553 PM CDT TUE SEP 8 2015 THE NORTHERN PLAINS REMAINS ON THE SOUTHERN EDGE OF A LARGE UPPER LOW ACROSS NORTHERN MANITOBA. THIS HAS MAINTAINED A BREEZY NORTHWEST FLOW ACROSS THE REGION SO FAR THIS AFTERNOON. AS THE EVENING APPROACHES EXPECT WINDS TO DIMINISH AFTER 7 PM AND SKIES TO BECOME MOSTLY CLEAR. UPDATED CURRENT OBSERVATIONS AND SKY CONDITION ONLY. && .SHORT TERM...(THIS EVENING THROUGH WEDNESDAY) ISSUED AT 239 PM CDT TUE SEP 8 2015 QUIET WEATHER HIGHLIGHTS THE SHORT TERM FORECAST. GIVEN GOOD AGREEMENT...UTILIZED A BLEND OF THE 12 UTC GUIDANCE SUITES. OVERALL...WEAK HIGH PRESSURE ACROSS WESTERN AND CENTRAL NORTH DAKOTA SOUTH OF THE FILLING NORTHERN MANITOBA LOW WILL CONTINUE TO WEAKEN THROUGH THE NIGHT. A WEAK IMPULSE EMBEDDED IN NORTHWEST FLOW ALOFT ON WEDNESDAY MAY SUPPORT ISOLATED RAIN SHOWER DEVELOPMENT DURING THE AFTERNOON. GIVEN WEAK MID LEVEL LAPSE RATES...DID NOT INCLUDE A MENTION OF THUNDER AT THIS TIME. TEMPERATURES WEDNESDAY ARE EXPECTED TO BE SIMILAR TO TODAY WITH 60S NORTH AND 70S SOUTH. .LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY) ISSUED AT 239 PM CDT TUE SEP 8 2015 NO MAIN CONCERNS IN THE LONG TERM WITH FAIRLY DRY AND QUIET WEATHER EXPECTED. EARLY IN THE LONG TERM THE NORTHWEST FLOW ALOFT WITH A FEW UPPER LEVEL SHORTWAVES...COMBINED WITH A COLD FRONTAL BOUNDARY OVER THE STATE WILL KEEP SMALL CHANCES OF SHOWERS IN THE FORECAST WEDNESDAY NIGHT AND THURSDAY. FAIRLY COOL WITH LOWS IN THE UPPER 30S TO UPPER 40S...AND HIGHS MAINLY IN THE 60S. ANOTHER COOL NIGHT THURSDAY NIGHT AS THE COOL HIGH PRESSURE CENTER SETTLES OVER THE DAKOTAS BY FRIDAY MORNING. LOWS IN THE MID TO UPPER 30S TO LOWER 40S. THEN A WARMING TREND INTO THE WEEKEND AS THE WESTERN RIDGE BUILDS BACK INTO THE WESTERN PLAINS. THE NEXT CHANCE FOR WIDESPREAD SHOWERS SHOULD BE TUESDAY. THE WESTERN RIDGE WILL BECOME MORE ZONAL OVER THE WEEKEND...THEN SOUTHWEST FLOW ALOFT RETURNS BY TUESDAY AS AN UPPER LEVEL TROUGH DIVES SOUTHEAST FROM THE GULF OF ALASKA INTO THE WEST COAST...DEVELOPING A SURFACE LOW IN THE LEE OF THE ROCKIES BY TUESDAY MORNING...BRINGING BETTER CHANCES FOR PRECIPITATION NEXT WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 1250 AM CDT WED SEP 9 2015 INCREASING MID TO UPPER LEVEL CLOUDS AS SURFACE LOW PRESSURE ACROSS NORTHEAST MONTANA AND AN ASSOCIATED WEAK COLD FRONT APPROACHES NORTH DAKOTA TONIGHT INTO WEDNESDAY. FOR THE 06Z TAF VFR IS EXPECTED. AN INCREASE IN CLOUDS AOA 5 THOUSAND AGL IS EXPECTED NORTH HALF OF THE STATE ALONG WITH VCSH FOR KISN-KMOT THROUGH THE PERIOD. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...NH SHORT TERM...AYD LONG TERM...JV AVIATION...NH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
658 PM EDT WED SEP 9 2015 .SYNOPSIS... A COLD FRONT OVER NORTHERN OHIO WILL CONTINUE TO MOVE SOUTHEAST AWAY FROM THE LOCAL AREA TONIGHT. THE FRONT IS EXPECTED TO EVENTUALLY STALL NEAR THE OHIO RIVER ON THURSDAY MORNING. WEAK HIGH PRESSURE WILL BUILD OVER THE REGION TOMORROW AND TOMORROW NIGHT. ANOTHER COLD FRONT WILL FOLLOW ON FRIDAY WITH A POTENT UPPER AIR DISTURBANCE EXPECTED TO IMPACT THE LOCAL AREA OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... SHOWERS HAVE DIMINISHED ACROSS MOST OF THE AREA EXCEPT A FEW SPRINKLES THAT MOVED INTO SOUTHERN HANCOCK COUNTY. MOST AREAS WILL BE DRY FOR THE REMAINDER OF THE NIGHT BUT LEFT A LOW 20-30 POP IN ACROSS THE SOUTHERN COUNTIES AS SOME SHORTWAVE ENERGY CONTINUES TO STREAM NORTHEAST. LOW LEVEL DRY AIR SHOULD WIN OUT ACROSS THE NORTHERN COUNTIES AND REMOVED ANY REMAINING CHANCE OF RAIN FROM THE FORECAST. LOW CLOUDS HAVE ALREADY SCATTERED OUT ACROSS NW OHIO SO ANY PRECIPITATION REACHING THE GROUND WILL BE VERY LIGHT AS IT FALLS OUT OF A MID-CLOUD DECK. PREVIOUS DISCUSSION... AS FEARED...LITTLE PRECIP HAS DEVELOPED THIS AFTERNOON. SOME SCATTERED SHOWERS REMAIN OVER THE EASTERN END OF THE AREA. MOST OF THE GUIDANCE INCLUDING THE LATEST RUC AND HRRR SHOW THE POSSIBILITY OF NEW DEVELOPMENT THROUGH EARLY EVENING FROM ABOUT I-71 EAST. THIS SEEM PLAUSIBLE GIVEN THE SHOWERS OVER INDIANA AND SW OHIO SO WILL KEEP A SMALL MENTION FOR A FEW HOURS. BY MIDNIGHT ALL BUT THE SE END OF THE AREA SHOULD BE DRY. THE SURFACE FRONT WILL EVENTUALLY STALL AND THE THREAT FOR SHOWERS ACROSS THE SE TIP OF THE AREA COULD PERSIST INTO THURSDAY MORNING. THE NEAREST CLEARING IS STILL BACK BY CHICAGO SO THAT WILL TAKE SOME TO REACH THE LOCAL AREA AS WELL. DO THINK THAT THAT ABOUT THE NW 1/3 TO 1/2 OF THE AREA WILL BECOME PARTLY CLOUDY BY MORNING. THIS WILL RESULT IN A DECENT TEMPERATURE GRADIENT ACROSS THE AREA WITH LOW 60S IN THE SE AND READINGS WELL DOWN INTO THE 50S IN THE NW. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/... JUST MINOR ADJUSTMENTS TO THE SHORT TERM TODAY AS THE PREVIOUS PACKAGE WAS ON THE RIGHT TRACK. THURSDAY AND THURSDAY NIGHT WILL BE DRY. ANOTHER COLD FRONT IS STILL ON TRACK FOR FRIDAY. VERY LITTLE IF ANY PRECIP IS EXPECTED BEFORE 12Z. WILL END UP GOING WITH A FEW HOURS OF LIKELY MOST AREAS. UNFORTUNATELY THE BEST WINDOW FOR PRECIP IN THE EAST WILL BE FRIDAY AFTERNOON AND EVENING. THERE WILL BE A DISTINCT AIRMASS CHANGE BEHIND THIS FRONT WITH THE UNSEASONABLY COOL AIR SETTLING OVER THE AREA OVER THE WEEKEND. AS A RESULT...INSTABILITY SHOWERS HELPED ALONG BY LAKE ERIE CAN BE EXPECTED BOTH SATURDAY AND SUNDAY. BY 12Z SUNDAY 500 MB TEMPS WILL BE ON THEIR WAY TO NEG 20 OR COLDER WHICH WILL GIVE LAKE TO 500MB TEMP DIFFERENCES OF 45 DEGREES OR GREATER. THIS MEANS THUNDER WILL BE A GOOD BET DOWNWIND OF THE LAKE AND HAVE BUMPED PRECIP CHANCES TO LIKELY IN FAR NE OH AND NW PA FOR SATURDAY NIGHT. HAVE CONTINUED THE RECENT TREND OF LOWERING HIGH TEMPS OVER THE WEEKEND. THERE COULD BE A FEW AREAS THAT FAIL TO GET OUT OF THE 50S FOR HIGHS ON SUNDAY. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AN UPPER LEVEL LOW WILL BE MOVING OFF TO THE EAST ON SUNDAY WILL BRING COLDER TEMPERATURES 10-15 DEGREES BELOW AVERAGE AND NORTHWESTERLY FLOW TO NORTHERN OHIO AND NORTHEAST PA. THIS NORTHWEST FLOW OFF OF LAKE ERIE...PLUS 850 MB TEMPERATURES OF 6-8C...AND WARM LAKE WATER TEMPERATURES AROUND 70F (A TEMPERATURE DIFFERENCE OF AROUND 25 DEGREES FAHRENHEIT) WILL ALLOW FOR SOME SIGNIFICANT LAKE EFFECT RAIN TO DEVELOP OVER THE AREA ON SUNDAY INTO THE EARLY PART OF MONDAY. IN SHORT...SUNDAY WILL BE MORE REPRESENTATIVE OF A COLD AND RAINY NOVEMBER DAY THAN THE GLIMPSE OF JULY THAT WE HAD OVER LABOR DAY WEEKEND. LATE ON MONDAY...SOME UPPER LEVEL RIDGING WILL MOVE IN ALONG WITH A SURFACE HIGH PRESSURE. WINDS WILL SHIFT TO COME FROM THE SOUTH AND WILL WARM TEMPERATURES CLOSER TO CLIMO AND DRY THE AREA OUT FROM WET WEATHER OVER THE WEEKEND. HIGH PRESSURE LOOKS TO BE IN PLACE THROUGH A MAJORITY OF WEDNESDAY ALLOWING FOR A COUPLE OF DRY...TYPICAL MID- SEPTEMBER DAYS IN NORTHERN OHIO AND NORTHWEST PA. MODELS CURRENTLY DEPICT A COLD FRONT BEGINNING TO APPROACH THE AREA BY THURSDAY MORNING...WHICH COULD BRING SOME WET WEATHER FOR THE END OF NEXT WEEK. STILL A LITTLE FAR OUT TO TELL WHAT COULD HAPPEN WITH THIS SYSTEM AS IT APPROACHES THE EASTERN GREAT LAKES. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... COLD FRONT IS NOW EAST OF THE TAF SITES WITH A FEW SCATTERED SHOWERS AND MAYBE A RUMBLE OF THUNDER LAGGING BEHIND. WIDESPREAD MVFR CONDITIONS WITH CEILINGS ON EITHER SIDE OF 2K FEET WILL BE COMMON THROUGH THE REMAINDER OF THE AFTERNOON. THE FRONTS EASTWARD PROGRESS SLOWS TONIGHT AND SHOWERS MAY CONTINUE ACROSS CAK/YNG INTO THE NIGHT. QUESTIONS WITH WHAT CEILINGS MAY DO OVERNIGHT. FORECAST SOUNDINGS AND OBSERVED SOUNDINGS SHOW THE LOWER LEVEL MOISTURE RESIDING BELOW MID LEVEL DRYING. GUIDANCE IS SUGGESTING VFR CONDITIONS OVERNIGHT...BUT WITH FRONT LINGERING TO OUR SOUTHEAST AND A NORTHEAST FLOW OFF OF THE LAKE...THINK AT LEAST KEEPING MVFR CEILINGS AROUND WOULD BE THE WAY TO GO. WINDS HAVE SHIFTED TO THE WEST- NORTHWEST TO NORTHWEST AND WILL CONTINUE TO ROTATE AROUND TO NORTHEAST THIS EVENING AND CONTINUE FROM THAT DIRECTION THURSDAY. OUTLOOK...NON VFR STARTING LATER FRIDAY AND CONTINUING THROUGH THE WEEKEND...ESPECIALLY FOR NE OH AND NW PA. && .MARINE... HAVE CANCELED THE SMALL CRAFT ADVISORY. LATEST GUIDANCE AND ANALYSIS OF CURRENT CONDITIONS LEADS TOWARD 2 TO OCCASIONALLY 4 FEET OVERNIGHT. THE GRADIENT IS NOT THAT TIGHT AND COLD AIR ADVECTION NOT STRONG. NORTH FLOW COMES AROUND TO THE NORTHEAST THIS EVENING AND WILL BE SITTING AT 10 TO 15 KNOTS SUSTAINED. HIGH PRESSURE WILL STAY NORTH OF THE LAKE ON THURSDAY AND GET SQUEEZED OUT BY AN APPROACHING COLD FRONT FROM THE NORTHWEST ON FRIDAY. THIS FRONT WILL HAVE THE POTENTIAL TO CHURN UP THE LAKE WITH STRONG COLD AIR ADVECTION COMMENCING FRIDAY NIGHT OR SATURDAY MORNING. SMALL CRAFT ADVISORIES A POSSIBILITY THIS WEEKEND. UPPER LOW STAYS IN THE VICINITY AND IT WILL BE A COOL AND SHOWERY WEEKEND. WINDS ARE NOT TOO STRONG ALOFT AND WATERSPOUTS MAY BE POSSIBLE THIS WEEKEND TOO. HIGH PRESSURE BUILDS ACROSS THE LOWER OHIO VALLEY MONDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KUBINA NEAR TERM...KUBINA SHORT TERM...KUBINA LONG TERM...SEFCOVIC AVIATION...OUDEMAN MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
345 PM EDT WED SEP 9 2015 .SYNOPSIS... A COLD FRONT OVER NORTHERN OHIO WILL CONTINUE TO MOVE SOUTHEAST AWAY FROM THE LOCAL AREA TONIGHT. THE FRONT IS EXPECTED TO EVENTUALLY STALL NEAR THE OHIO RIVER ON THURSDAY MORNING. WEAK HIGH PRESSURE WILL BUILD OVER THE REGION TOMORROW AND TOMORROW NIGHT. ANOTHER COLD FRONT WILL FOLLOW ON FRIDAY WITH A POTENT UPPER AIR DISTURBANCE EXPECTED TO IMPACT THE LOCAL AREA OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS FEARED...LITTLE PRECIP HAS DEVELOPED THIS AFTERNOON. SOME SCATTERED SHOWERS REMAIN OVER THE EASTERN END OF THE AREA. MOST OF THE GUIDANCE INCLUDING THE LATEST RUC AND HRRR SHOW THE POSSIBILITY OF NEW DEVELOPMENT THROUGH EARLY EVENING FROM ABOUT I-71 EAST. THIS SEEM PLAUSIBLE GIVEN THE SHOWERS OVER INDIANA AND SW OHIO SO WILL KEEP A SMALL MENTION FOR A FEW HOURS. BY MIDNIGHT ALL BUT THE SE END OF THE AREA SHOULD BE DRY. THE SURFACE FRONT WILL EVENTUALLY STALL AND THE THREAT FOR SHOWERS ACROSS THE SE TIP OF THE AREA COULD PERSIST INTO THURSDAY MORNING. THE NEAREST CLEARING IS STILL BACK BY CHICAGO SO THAT WILL TAKE SOME TO REACH THE LOCAL AREA AS WELL. DO THINK THAT THAT ABOUT THE NW 1/3 TO 1/2 OF THE AREA WILL BECOME PARTLY CLOUDY BY MORNING. THIS WILL RESULT IN A DECENT TEMPERATURE GRADIENT ACROSS THE AREA WITH LOW 60S IN THE SE AND READINGS WELL DOWN INTO THE 50S IN THE NW. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/... JUST MINOR ADJUSTMENTS TO THE SHORT TERM TODAY AS THE PREVIOUS PACKAGE WAS ON THE RIGHT TRACK. THURSDAY AND THURSDAY NIGHT WILL BE DRY. ANOTHER COLD FRONT IS STILL ON TRACK FOR FRIDAY. VERY LITTLE IF ANY PRECIP IS EXPECTED BEFORE 12Z. WILL END UP GOING WITH A FEW HOURS OF LIKELY MOST AREAS. UNFORTUNATELY THE BEST WINDOW FOR PRECIP IN THE EAST WILL BE FRIDAY AFTERNOON AND EVENING. THERE WILL BE A DISTINCT AIRMASS CHANGE BEHIND THIS FRONT WITH THE UNSEASONABLY COOL AIR SETTLING OVER THE AREA OVER THE WEEKEND. AS A RESULT...INSTABILITY SHOWERS HELPED ALONG BY LAKE ERIE CAN BE EXPECTED BOTH SATURDAY AND SUNDAY. BY 12Z SUNDAY 500 MB TEMPS WILL BE ON THEIR WAY TO NEG 20 OR COLDER WHICH WILL GIVE LAKE TO 500MB TEMP DIFFERENCES OF 45 DEGREES OR GREATER. THIS MEANS THUNDER WILL BE A GOOD BET DOWNWIND OF THE LAKE AND HAVE BUMPED PRECIP CHANCES TO LIKELY IN FAR NE OH AND NW PA FOR SATURDAY NIGHT. HAVE CONTINUED THE RECENT TREND OF LOWERING HIGH TEMPS OVER THE WEEKEND. THERE COULD BE A FEW AREAS THAT FAIL TO GET OUT OF THE 50S FOR HIGHS ON SUNDAY. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... AN UPPER LEVEL LOW WILL BE MOVING OFF TO THE EAST ON SUNDAY WILL BRING COLDER TEMPERATURES 10-15 DEGREES BELOW AVERAGE AND NORTHWESTERLY FLOW TO NORTHERN OHIO AND NORTHEAST PA. THIS NORTHWEST FLOW OFF OF LAKE ERIE...PLUS 850 MB TEMPERATURES OF 6-8C...AND WARM LAKE WATER TEMPERATURES AROUND 70F (A TEMPERATURE DIFFERENCE OF AROUND 25 DEGREES FAHRENHEIT) WILL ALLOW FOR SOME SIGNIFICANT LAKE EFFECT RAIN TO DEVELOP OVER THE AREA ON SUNDAY INTO THE EARLY PART OF MONDAY. IN SHORT...SUNDAY WILL BE MORE REPRESENTATIVE OF A COLD AND RAINY NOVEMBER DAY THAN THE GLIMPSE OF JULY THAT WE HAD OVER LABOR DAY WEEKEND. LATE ON MONDAY...SOME UPPER LEVEL RIDGING WILL MOVE IN ALONG WITH A SURFACE HIGH PRESSURE. WINDS WILL SHIFT TO COME FROM THE SOUTH AND WILL WARM TEMPERATURES CLOSER TO CLIMO AND DRY THE AREA OUT FROM WET WEATHER OVER THE WEEKEND. HIGH PRESSURE LOOKS TO BE IN PLACE THROUGH A MAJORITY OF WEDNESDAY ALLOWING FOR A COUPLE OF DRY...TYPICAL MID- SEPTEMBER DAYS IN NORTHERN OHIO AND NORTHWEST PA. MODELS CURRENTLY DEPICT A COLD FRONT BEGINNING TO APPROACH THE AREA BY THURSDAY MORNING...WHICH COULD BRING SOME WET WEATHER FOR THE END OF NEXT WEEK. STILL A LITTLE FAR OUT TO TELL WHAT COULD HAPPEN WITH THIS SYSTEM AS IT APPROACHES THE EASTERN GREAT LAKES. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... COLD FRONT IS NOW EAST OF THE TAF SITES WITH A FEW SCATTERED SHOWERS AND MAYBE A RUMBLE OF THUNDER LAGGING BEHIND. WIDESPREAD MVFR CONDITIONS WITH CEILINGS ON EITHER SIDE OF 2K FEET WILL BE COMMON THROUGH THE REMAINDER OF THE AFTERNOON. THE FRONTS EASTWARD PROGRESS SLOWS TONIGHT AND SHOWERS MAY CONTINUE ACROSS CAK/YNG INTO THE NIGHT. QUESTIONS WITH WHAT CEILINGS MAY DO OVERNIGHT. FORECAST SOUNDINGS AND OBSERVED SOUNDINGS SHOW THE LOWER LEVEL MOISTURE RESIDING BELOW MID LEVEL DRYING. GUIDANCE IS SUGGESTING VFR CONDITIONS OVERNIGHT...BUT WITH FRONT LINGERING TO OUR SOUTHEAST AND A NORTHEAST FLOW OFF OF THE LAKE...THINK AT LEAST KEEPING MVFR CEILINGS AROUND WOULD BE THE WAY TO GO. WINDS HAVE SHIFTED TO THE WEST- NORTHWEST TO NORTHWEST AND WILL CONTINUE TO ROTATE AROUND TO NORTHEAST THIS EVENING AND CONTINUE FROM THAT DIRECTION THURSDAY. OUTLOOK...NON VFR STARTING LATER FRIDAY AND CONTINUING THROUGH THE WEEKEND...ESPECIALLY FOR NE OH AND NW PA. && .MARINE... HAVE CANCELED THE SMALL CRAFT ADVISORY. LATEST GUIDANCE AND ANALYSIS OF CURRENT CONDITIONS LEADS TOWARD 2 TO OCCASIONALLY 4 FEET OVERNIGHT. THE GRADIENT IS NOT THAT TIGHT AND COLD AIR ADVECTION NOT STRONG. NORTH FLOW COMES AROUND TO THE NORTHEAST THIS EVENING AND WILL BE SITTING AT 10 TO 15 KNOTS SUSTAINED. HIGH PRESSURE WILL STAY NORTH OF THE LAKE ON THURSDAY AND GET SQUEEZED OUT BY AN APPROACHING COLD FRONT FROM THE NORTHWEST ON FRIDAY. THIS FRONT WILL HAVE THE POTENTIAL TO CHURN UP THE LAKE WITH STRONG COLD AIR ADVECTION COMMENCING FRIDAY NIGHT OR SATURDAY MORNING. SMALL CRAFT ADVISORIES A POSSIBILITY THIS WEEKEND. UPPER LOW STAYS IN THE VICINITY AND IT WILL BE A COOL AND SHOWERY WEEKEND. WINDS ARE NOT TOO STRONG ALOFT AND WATERSPOUTS MAY BE POSSIBLE THIS WEEKEND TOO. HIGH PRESSURE BUILDS ACROSS THE LOWER OHIO VALLEY MONDAY. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KUBINA NEAR TERM...KUBINA SHORT TERM...KUBINA LONG TERM...SEFCOVIC AVIATION...OUDEMAN MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
657 AM EDT WED SEP 9 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION TODAY THROUGH TONIGHT...BRINGING OCCASIONAL SHOWERS AND A CHANCE OF A FEW THUNDERSTORMS. COOLER AIR WILL SETTLE IN BEHIND THIS FRONT BY THURSDAY. ANOTHER FRONT WILL MOVE THROUGH THE REGION ON FRIDAY...WITH EVEN COOLER CONDITIONS EXPECTED FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS HIGH PRESSURE SOUTHEAST OF THE OHIO VALLEY LOSES ITS INFLUENCE OVER THE REGION...A TRANSITION IN WEATHER PATTERN IS UNDERWAY. SURFACE OBSERVATIONS AT 07Z PLACE A COLD FRONT ALONG AN AXIS FROM BAD AXE MICHIGAN TO SPRINGFIELD ILLINOIS. WHAT THIS FRONT WILL EVENTUALLY USHER IN OVER THE NEXT DAY OR SO IS A 10-12 DEGREE DROP IN TEMPERATURES...ALONG WITH LESS HUMID CONDITIONS. WHAT THE FRONT LACKS IS MUCH IN THE WAY OF FOCUS...STRENGTH...OR SPEED. IT WILL TAKE MOST OF THE DAY FOR THE SURFACE FRONT TO CROSS THE FORECAST AREA...WHICH WILL ALLOW FOR ANOTHER DAY OF FAIRLY WARM CONDITIONS IN THE SOUTHEASTERN CWA...WITH NOTICEABLY COOLER TEMPERATURES IN THE NORTHWESTERN CWA. WITH FORCING NOT EXPECTED TO BE PARTICULARLY STRONG...COVERAGE AND INTENSITY OF PRECIPITATION IS IN QUESTION. POPS TODAY RANGE FROM 70 (NW) TO 90 (SE) PERCENT...WITH THUNDER SEEMING MOST LIKELY IN THE WARMER AIR IN THE SOUTHEASTERN CWA. PRECIPITATION POTENTIAL APPEARS MAXIMIZED JUST AHEAD OF A (VERY) WEAK SURFACE LOW...WHICH WILL ALLOW FOR A LITTLE EXTRA LIFT AHEAD OF ITS TRACK (ACROSS EASTERN KENTUCKY AND INTO WEST VIRGINIA). ALTHOUGH THE ATMOSPHERE IS FAIRLY MOIST...THE COMBINATION OF POOR MID-LEVEL LAPSE RATES AND COOLING CONDITIONS AT THE SURFACE WILL SEVERELY LIMIT INSTABILITY...WITH MLCAPE VALUES LIKELY TO REMAIN BELOW 1000 J/KG. IN FACT...USING THE RECENT HRRR RUNS AS GUIDANCE...AREAS NORTH OF THE INTERSTATE 71 CORRIDOR MAY NOT SEE MUCH (IF ANY) POTENTIAL FOR THUNDERSTORMS AT ALL. WITH THE WEAK FORCING AND LACK OF ANY NOTABLE WIND SHEAR...STRONG STORMS APPEAR FAIRLY UNLIKELY TODAY. SOME BRIEF HEAVY RAIN COULD OCCUR IN THE SOUTHEASTERN CWA...ESPECIALLY IF THE CELLS DO NOT MOVE QUICKLY. THE AFTERNOON WILL END WITH THE FRONT CLEARING THE SOUTHEASTERN CWA...BUT SOME POST-FRONTAL SHOWERS WILL BE POSSIBLE ELSEWHERE...SO POPS WILL BE MAINTAINED INTO THE EVENING. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... A SHORTWAVE WELL BEHIND THE COLD FRONT WILL REMAIN JUST WEST OF THE FORECAST AREA TO START THE DAY ON THURSDAY...MOVING SLOWLY THROUGH THE REGION THROUGH EVENING. THIS WILL ALLOW FOR A CONTINUED CHANCE OF SHOWERS IN THE SOUTHEASTERN SECTIONS OF THE FORECAST AREA...WITH A SLIGHT CHANCE OF A THUNDERSTORM NEAR PEAK HEATING. UNDER THE INFLUENCE OF HIGH PRESSURE...WHICH WILL STRETCH WEST-TO-EAST ACROSS THE SOUTHERN GREAT LAKES...THE NORTHWESTERN HALF OF THE FORECAST AREA IS LIKELY TO REMAIN DRY. NAM/GFS/ECMWF TEMPERATURE PROJECTIONS ARE IN VERY GOOD AGREEMENT...WITH THE WARMEST CONDITIONS (LOWER 80S) IN THE SOUTHWESTERN CWA...AND SLIGHTLY COOLER CONDITIONS (UPPER 70S) IN THE NORTHEASTERN CWA. ATTENTION ON FRIDAY AND GOING INTO THE WEEKEND WILL TURN TOWARD THE DEVELOPMENT OF A LARGE MID-LEVEL TROUGH...WHICH APPEARS TO BE MODELED MORE ENERGETICALLY ON THE 00Z RUNS EARLY THIS MORNING. AHEAD OF THIS TROUGH...ANOTHER COLD FRONT WILL SLICE ACROSS THE UPPER MISSISSIPPI VALLEY ON THURSDAY NIGHT INTO FRIDAY...CLEARING THROUGH THE OHIO VALLEY ON FRIDAY NIGHT INTO SATURDAY. THIS FRONT WILL SHAVE ROUGHLY ANOTHER 10 DEGREES OFF THE TEMPERATURES...LEADING TO AN EXPECTATION FOR BELOW-NORMAL CONDITIONS OVER THE WEEKEND. THE GREATEST POTENTIAL FOR PRECIPITATION APPEARS TO BE FROM FRIDAY AFTERNOON THROUGH EARLY SATURDAY MORNING. THE FRONTAL FORCING THIS TIME MAY BE A LITTLE STRONGER THAN WITH THE SYSTEM TODAY (WEDNESDAY)...BUT INSTABILITY WILL BE ALMOST COMPLETELY LACKING. IF THERE WILL BE A CHANCE FOR THUNDER...IT MAY BE CONFINED TO THE SOUTHERN SECTIONS OF THE FORECAST AREA...AND EVEN THIS IS NOT CERTAIN. POPS WERE INCREASED TO 40-PERCENT ACROSS THE BOARD AS THIS SYSTEM PASSES WNW-TO-ESE THROUGH THE CWA...AND IF THE 00Z ECMWF/GFS PROJECTIONS ARE THE START OF THE TREND...THESE VALUES WILL HAVE TO BE INCREASED FURTHER IN FUTURE FORECASTS. IF THE TROUGH REMAINS IN PLACE...CONDITIONS MAY NOT COMPLETELY DRY OUT ON SATURDAY. SKY GRIDS WERE INCREASED TO ACCOUNT FOR THIS...WITH 20-30 PERCENT POPS MAINTAINED THROUGH THE DAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... SHOWERS WILL DIMINISH BUT NOT DISAPPEAR SUNDAY AS THE UPPER LOW GRADUALLY LIFTS NORTHEAST. A BROAD UPPER RIDGE IS THEN INDICATED TO PUSH ACROSS MOST OF THE CONUS BY TUESDAY...COUPLING WITH A SURFACE HIGH TO USHER IN A PERIOD OF DRY WEATHER FOR THE OHIO VALLEY REGION. TEMPERATURES WILL VARY NOTABLY WITH RESPECT TO THE UNDULATING UPPER AIR PATTERN. HIGHS ARE FORECAST TO BE NEAR NORMAL IN THE UPPER 70S ON FRIDAY. BELOW NORMAL READINGS IN THE UPPER 60S ARE EXPECTED FOR SATURDAY AND SUNDAY UNDER THE UPPER LOW AND ASSOCIATED CLOUDS AND PRECIP. A RETURN TO NEAR NORMAL UPPER 70S SHOULD OCCUR BY TUESDAY IN WARM ADVECTION ON A SOUTHWEST LOW LEVEL FLOW CIRCULATING AROUND THE HIGH. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... A COLD FRONT WILL SLOWLY MAKE ITS WAY SOUTHEAST THROUGH OUR REGION TODAY. MEANWHILE...MODELS SUGGEST THAT A WEAK WAVE OF LOW PRESSURE WILL TRY TO MOVE WEST TO EAST ALONG THE FRONTAL BOUNDARY NEAR THE OHIO RIVER. THE AIRMASS WILL BECOME INCREASINGLY MOIST AHEAD OF THE FRONT TODAY. THE FORCING WITH THE FRONT...LOW...AND SOME UPPER LEVEL ENERGY IS WEAK. THIS WILL MAKE IT DIFFICULT TO PINPOINT THE BEST TIMING FOR SHOWERS AND EMBEDDED THUNDERSTORMS. BEST COVERAGE PER HIGH RESOLUTION MODELS SEEM TO FAVOR THE PERIOD FROM EARLY AFTERNOON TO THE EARLY EVENING HOURS WHEN INSTABILITY WILL BE AT ITS MAXIMUM. IN THIS UPDATE...IT APPEARS THAT THE THREAT FOR THUNDER WILL OCCUR ALONG AND SOUTHEAST OF THE SLOW MOVING COLD FRONT AND NEAR THE WEAK SFC WAVE. AS SUCH...HAVE KEPT THE VCTS DESCRIPTORS AT THE SOUTHERN TAF SITES OF KCVG/KLUK. OTHERWISE...ALL TAF SITES WILL HAVE THE THREAT FOR MVFR CONDITIONS. IT SHOULD BE NOTED THAT WITH THE MOIST AIRMASS...WELL DEVELOPED SHOWERS AND ESPECIALLY ANY THUNDERSTORMS...WILL BE CAPABLE OF LOWER VISIBILITIES IN THE IFR/LIFR CATEGORY...SO AVIATORS SHOULD BE AWARE OF THIS POTENTIAL. FOR TONIGHT...THE FRONTAL BOUNDARY WILL CONTINUE ON ITS WAY TO OUR SOUTHEAST AS THE WEAK WAVE OF LOW PRESSURE BEGINS TO TRANSFER AND DEEPEN OVER THE MID ATLANTIC REGION. PRECIPITATION THREAT SHOULD BE EXITING AWAY FROM THE TAF SITES BETWEEN 00Z AND 09Z. WILL FORECAST VFR CEILINGS/VISIBILITIES OVERNIGHT FOR THE NORTHERN TAF SITES. IT APPEARS THAT KILN...KCVG...AND KLUK MAY DROP INTO PREDOMINATE MVFR CEILINGS LATE (WHERE IT MAY RAIN THE MOST TODAY) WHERE LOW LEVELS WILL SATURATE THE BEST OVERNIGHT. OUTLOOK...MVFR CEILINGS POSSIBLE THURSDAY MORNING. THUNDERSTORMS POSSIBLE FRIDAY INTO FRIDAY EVENING. MVFR CEILINGS POSSIBLE AGAIN FRIDAY NIGHT INTO SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM...CONIGLIO AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
343 AM EDT WED SEP 9 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE REGION TODAY THROUGH TONIGHT...BRINGING OCCASIONAL SHOWERS AND A CHANCE OF A FEW THUNDERSTORMS. COOLER AIR WILL SETTLE IN BEHIND THIS FRONT BY THURSDAY. ANOTHER FRONT WILL MOVE THROUGH THE REGION ON FRIDAY...WITH EVEN COOLER CONDITIONS EXPECTED FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS HIGH PRESSURE SOUTHEAST OF THE OHIO VALLEY LOSES ITS INFLUENCE OVER THE REGION...A TRANSITION IN WEATHER PATTERN IS UNDERWAY. SURFACE OBSERVATIONS AT 07Z PLACE A COLD FRONT ALONG AN AXIS FROM BAD AXE MICHIGAN TO SPRINGFIELD ILLINOIS. WHAT THIS FRONT WILL EVENTUALLY USHER IN OVER THE NEXT DAY OR SO IS A 10-12 DEGREE DROP IN TEMPERATURES...ALONG WITH LESS HUMID CONDITIONS. WHAT THE FRONT LACKS IS MUCH IN THE WAY OF FOCUS...STRENGTH...OR SPEED. IT WILL TAKE MOST OF THE DAY FOR THE SURFACE FRONT TO CROSS THE FORECAST AREA...WHICH WILL ALLOW FOR ANOTHER DAY OF FAIRLY WARM CONDITIONS IN THE SOUTHEASTERN CWA...WITH NOTICEABLY COOLER TEMPERATURES IN THE NORTHWESTERN CWA. WITH FORCING NOT EXPECTED TO BE PARTICULARLY STRONG...COVERAGE AND INTENSITY OF PRECIPITATION IS IN QUESTION. POPS TODAY RANGE FROM 70 (NW) TO 90 (SE) PERCENT...WITH THUNDER SEEMING MOST LIKELY IN THE WARMER AIR IN THE SOUTHEASTERN CWA. PRECIPITATION POTENTIAL APPEARS MAXIMIZED JUST AHEAD OF A (VERY) WEAK SURFACE LOW...WHICH WILL ALLOW FOR A LITTLE EXTRA LIFT AHEAD OF ITS TRACK (ACROSS EASTERN KENTUCKY AND INTO WEST VIRGINIA). ALTHOUGH THE ATMOSPHERE IS FAIRLY MOIST...THE COMBINATION OF POOR MID-LEVEL LAPSE RATES AND COOLING CONDITIONS AT THE SURFACE WILL SEVERELY LIMIT INSTABILITY...WITH MLCAPE VALUES LIKELY TO REMAIN BELOW 1000 J/KG. IN FACT...USING THE RECENT HRRR RUNS AS GUIDANCE...AREAS NORTH OF THE INTERSTATE 71 CORRIDOR MAY NOT SEE MUCH (IF ANY) POTENTIAL FOR THUNDERSTORMS AT ALL. WITH THE WEAK FORCING AND LACK OF ANY NOTABLE WIND SHEAR...STRONG STORMS APPEAR FAIRLY UNLIKELY TODAY. SOME BRIEF HEAVY RAIN COULD OCCUR IN THE SOUTHEASTERN CWA...ESPECIALLY IF THE CELLS DO NOT MOVE QUICKLY. THE AFTERNOON WILL END WITH THE FRONT CLEARING THE SOUTHEASTERN CWA...BUT SOME POST-FRONTAL SHOWERS WILL BE POSSIBLE ELSEWHERE...SO POPS WILL BE MAINTAINED INTO THE EVENING. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... A SHORTWAVE WELL BEHIND THE COLD FRONT WILL REMAIN JUST WEST OF THE FORECAST AREA TO START THE DAY ON THURSDAY...MOVING SLOWLY THROUGH THE REGION THROUGH EVENING. THIS WILL ALLOW FOR A CONTINUED CHANCE OF SHOWERS IN THE SOUTHEASTERN SECTIONS OF THE FORECAST AREA...WITH A SLIGHT CHANCE OF A THUNDERSTORM NEAR PEAK HEATING. UNDER THE INFLUENCE OF HIGH PRESSURE...WHICH WILL STRETCH WEST-TO-EAST ACROSS THE SOUTHERN GREAT LAKES...THE NORTHWESTERN HALF OF THE FORECAST AREA IS LIKELY TO REMAIN DRY. NAM/GFS/ECMWF TEMPERATURE PROJECTIONS ARE IN VERY GOOD AGREEMENT...WITH THE WARMEST CONDITIONS (LOWER 80S) IN THE SOUTHWESTERN CWA...AND SLIGHTLY COOLER CONDITIONS (UPPER 70S) IN THE NORTHEASTERN CWA. ATTENTION ON FRIDAY AND GOING INTO THE WEEKEND WILL TURN TOWARD THE DEVELOPMENT OF A LARGE MID-LEVEL TROUGH...WHICH APPEARS TO BE MODELED MORE ENERGETICALLY ON THE 00Z RUNS EARLY THIS MORNING. AHEAD OF THIS TROUGH...ANOTHER COLD FRONT WILL SLICE ACROSS THE UPPER MISSISSIPPI VALLEY ON THURSDAY NIGHT INTO FRIDAY...CLEARING THROUGH THE OHIO VALLEY ON FRIDAY NIGHT INTO SATURDAY. THIS FRONT WILL SHAVE ROUGHLY ANOTHER 10 DEGREES OFF THE TEMPERATURES...LEADING TO AN EXPECTATION FOR BELOW-NORMAL CONDITIONS OVER THE WEEKEND. THE GREATEST POTENTIAL FOR PRECIPITATION APPEARS TO BE FROM FRIDAY AFTERNOON THROUGH EARLY SATURDAY MORNING. THE FRONTAL FORCING THIS TIME MAY BE A LITTLE STRONGER THAN WITH THE SYSTEM TODAY (WEDNESDAY)...BUT INSTABILITY WILL BE ALMOST COMPLETELY LACKING. IF THERE WILL BE A CHANCE FOR THUNDER...IT MAY BE CONFINED TO THE SOUTHERN SECTIONS OF THE FORECAST AREA...AND EVEN THIS IS NOT CERTAIN. POPS WERE INCREASED TO 40-PERCENT ACROSS THE BOARD AS THIS SYSTEM PASSES WNW-TO-ESE THROUGH THE CWA...AND IF THE 00Z ECMWF/GFS PROJECTIONS ARE THE START OF THE TREND...THESE VALUES WILL HAVE TO BE INCREASED FURTHER IN FUTURE FORECASTS. IF THE TROUGH REMAINS IN PLACE...CONDITIONS MAY NOT COMPLETELY DRY OUT ON SATURDAY. SKY GRIDS WERE INCREASED TO ACCOUNT FOR THIS...WITH 20-30 PERCENT POPS MAINTAINED THROUGH THE DAY. && .LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/... SHOWERS WILL DIMINISH BUT NOT DISAPPEAR SUNDAY AS THE UPPER LOW GRADUALLY LIFTS NORTHEAST. A BROAD UPPER RIDGE IS THEN INDICATED TO PUSH ACROSS MOST OF THE CONUS BY TUESDAY...COUPLING WITH A SURFACE HIGH TO USHER IN A PERIOD OF DRY WEATHER FOR THE OHIO VALLEY REGION. TEMPERATURES WILL VARY NOTABLY WITH RESPECT TO THE UNDULATING UPPER AIR PATTERN. HIGHS ARE FORECAST TO BE NEAR NORMAL IN THE UPPER 70S ON FRIDAY. BELOW NORMAL READINGS IN THE UPPER 60S ARE EXPECTED FOR SATURDAY AND SUNDAY UNDER THE UPPER LOW AND ASSOCIATED CLOUDS AND PRECIP. A RETURN TO NEAR NORMAL UPPER 70S SHOULD OCCUR BY TUESDAY IN WARM ADVECTION ON A SOUTHWEST LOW LEVEL FLOW CIRCULATING AROUND THE HIGH. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... A COLD FRONT WILL SLOWLY MAKE ITS WAY SOUTHEAST THROUGH OUR REGION TODAY. MEANWHILE...MODELS SUGGEST THAT A WEAK WAVE OF LOW PRESSURE WILL TRY TO MOVE WEST TO EAST ALONG THE FRONTAL BOUNDARY NEAR THE OHIO RIVER. THE AIRMASS WILL BECOME INCREASINGLY MOIST AHEAD OF THE FRONT TODAY. THE FORCING WITH THE FRONT...LOW...AND SOME UPPER LEVEL ENERGY IS WEAK. THIS WILL MAKE IT DIFFICULT TO PINPOINT THE BEST TIMING FOR SHOWERS AND EMBEDDED THUNDERSTORMS AT THE TAF SITES. BEST COVERAGE PER HIGH RESOLUTION MODELS SEEM TO FAVOR THE EARLY TO LATE AFTERNOON HOURS WHEN INSTABILITY WILL BE AT ITS MAXIMUM. AS SUCH...HAD ADDED VCTS DESCRIPTORS AT ALL TAF SITES EXCEPT DAYTON WITH TEMPO MVFR CONDITIONS IN SHOWERS. WITH THE INSTABILITY NOT BEING OVERLY GREAT...HAVE NOT GONE WITH TEMPO TSRA ATTM. IT SHOULD BE NOTED THAT WITH THE MOIST AIRMASS...WELL DEVELOPED SHOWERS AND ESPECIALLY ANY THUNDERSTORMS...WILL BE CAPABLE OF LOWER VISIBILITIES IN THE IFR/LIFR CATEGORY...SO AVIATORS SHOULD BE AWARE OF THIS POTENTIAL. FOR TONIGHT...THE FRONTAL BOUNDARY WILL CONTINUE ON ITS WAY TO OUR SOUTHEAST AS THE WEAK WAVE OF LOW PRESSURE BEGINS TO TRANSFER AND DEEPEN OVER THE MID ATLANTIC REGION. PRECIPITATION THREAT SHOULD BE EXITING AWAY FROM THE TAF SITES BETWEEN THE 22Z AND 03Z TIME FRAME. WILL FORECAST VFR CEILINGS/VISIBILITIES OVERNIGHT FOR NOW...BUT THERE IS SOME SUGGESTION THAT MVFR CEILINGS COULD FORM IN THE POST FRONTAL AIRMASS NEAR THE OHIO RIVER TOWARD THURSDAY MORNING. OUTLOOK...MVFR CEILINGS POSSIBLE THURSDAY MORNING. THUNDERSTORMS POSSIBLE FRIDAY INTO FRIDAY EVENING. MVFR CEILINGS POSSIBLE AGAIN FRIDAY NIGHT INTO SATURDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...HATZOS NEAR TERM...HATZOS SHORT TERM...HATZOS LONG TERM...CONIGLIO AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS NORMAN OK
1034 PM CDT THU SEP 10 2015 .DISCUSSION... && .AVIATION... A COLD FRONT WITH SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE NORTHERN HALF OF OKLAHOMA OVERNIGHT BRINGING A PERIOD OF GUSTY NORTH WINDS IN ITS WAKE. THE FRONT WILL SLOW AND ARRIVE NEAR THE RED RIVER FRIDAY AFTERNOON WHERE ADDITIONAL THUNDERSTORMS ARE EXPECTED. MVFR CONDITIONS ARE EXPECTED BEHIND THE FRONT FOR A GOOD PORTION OF THE DAYTIME FRIDAY. && .PREV DISCUSSION... /ISSUED 1005 PM CDT THU SEP 10 2015/ UPDATE... UPDATED POP AND WIND GRIDS THROUGH 12Z. DISCUSSION... SHOWERS AND THUNDERSTORMS HAVE CONSOLIDATED INTO A COMPLEX ACROSS CENTRAL KANSAS THIS EVENING. ANY ADDITIONAL DEVELOPMENT AHEAD OF THE PRIMARY COMPLEX HAS DISSIPATED. THE HRRR APPEARS TOO FAST WITH THE SOUTHWARD PROGRESS OF THE THUNDERSTORM COMPLEX. THEREFORE...OPTED TO DECREASE PRECIPITATION CHANCES SUBSTANTIALLY THROUGH 06Z. NORTH CENTRAL OKLAHOMA APPEARS TO HAVE THE MOST LIKELY CHANCE OF BEING INFLUENCED BY THE THUNDERSTORM COMPLEX. CONSEQUENTLY...INCREASED PRECIPITATION CHANCES ACROSS NORTH CENTRAL AND EAST CENTRAL OKLAHOMA AFTER 06Z. MAHALE PREV DISCUSSION... /ISSUED 250 PM CDT THU SEP 10 2015/ DISCUSSION... PRIMARY FORECAST CONCERN IS FOCUSED ON PRECIPITATION CHANCES TONIGHT THROUGH FRIDAY IN RESPONSE TO A COLD FRONT MOVING ACROSS THE AREA. CURRENTLY... 19Z SFC ANALYSIS PLACES THE COLD FRONT NEAR THE NE/KS BORDER... WITH INCREASING CU DEVELOPMENT ALONG AND AHEAD OF THE FRONT ACROSS NRN INTO CENTRAL KS. THIS FRONT WILL CONTINUE TO PUSH SOUTHWARD THROUGH THE AFTN INTO THE EVENING... APPROACHING THE OK/KS BORDER THROUGH THIS EVENING. CONTINUITY BETWEEN TRADITIONAL AND MESOSCALE GUIDANCE REMAINS DECENT. THE HRRR AND HIRES WRFS CONTINUE TO GENERATE CONVECTION WITH THE SFC TROUGH OVER THE PANHANDLES THROUGH 00Z... THE 12Z NAM IS A STEP SLOWER... BUT SIMILAR. GIVEN INCREASING DPTS THIS AFTN AND AN INCREASING ISENTROPIC RESPONSE INTO THE EVENING ACROSS NWRN OK... FELT COMFORTABLE TO INCREASE PRECIP CHCS IN THE NW BETWEEN 00-06Z. EXPECT PRECIP COVERAGE TO INCREASE INCREMENTALLY OVERNIGHT WITH THE BEST CHANCES AFTER MIDNIGHT THROUGH SUNRISE ACROSS NRN AND NERN OK. AS FOR SEVERE CHANCES... MODEST ML- CAPE VALUES 1000-1700 J/KG ARE POSSIBLE THIS EVENING AND OVERNIGHT... WITH 20 TO 30 KTS OF 0-6KM SHEAR. LOOKING AT BUFR SOUNDINGS... MOST OF THIS INSTABILITY IS WELL ELEVATED... WITH ANY STRONGER STORMS DEVELOPING A HAIL OR WIND THREAT... QUARTER TO HALF DOLLAR SIZE HAIL AND 60 MPH WINDS. OVERALL... THE CHANCE FOR SEVERE STORMS WILL RESIDE WITHIN A NARROW WINDOW OF TIME ACROSS NRN OK THIS EVENING THROUGH SUNSET. FRIDAY... SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY BE ONGOING AROUND SUNRISE ACROSS NERN INTO CENTRAL OK. CHANCES WILL CONTINUE THROUGH THE AFTN ACROSS MUCH OF THE REGION AS THE COLD FRONT PUSHES TOWARDS THE RED RIVER THROUGH THE AFTN. INTO THE LATE AFTN/EVENING... SOME STEEPER LAPSE RATES MAY DEVELOP... RESULTING IN SOME STRONGER THUNDERSTORMS NEAR THE RED RIVER. HOWEVER... SEVERE CHANCES REMAIN LOW. SHOULD BE A WONDERFUL WEEKEND AS TEMPS REMAIN MILD... WITH HIGHS IN THE UPPER 70S AND LOWER 80S EACH DAY. TEMPS WILL START TO REBOUND EARLY NEXT WEEK AS SRLY FLOW RETURNS AND TROUGHING DEVELOPS OVER THE WRN US MON-TUE. OVERALL... THE FORECAST REMAINS DRY THROUGH MUCH OF NEXT WEEK... WITH THE NEXT BEST CHANCE FOR PRECIP LATE NEXT WEEK AS A FRONTAL BOUNDARY APPROACHES THE REGION. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 68 80 55 78 / 30 40 0 0 HOBART OK 68 81 58 81 / 10 30 10 0 WICHITA FALLS TX 70 87 59 83 / 10 30 10 0 GAGE OK 63 78 54 81 / 40 30 10 0 PONCA CITY OK 66 78 51 75 / 80 40 0 0 DURANT OK 71 87 59 81 / 0 40 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 10/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
1005 PM CDT THU SEP 10 2015 .UPDATE... UPDATED POP AND WIND GRIDS THROUGH 12Z. && .DISCUSSION... SHOWERS AND THUNDERSTORMS HAVE CONSOLIDATED INTO A COMPLEX ACROSS CENTRAL KANSAS THIS EVENING. ANY ADDITIONAL DEVELOPMENT AHEAD OF THE PRIMARY COMPLEX HAS DISSIPATED. THE HRRR APPEARS TOO FAST WITH THE SOUTHWARD PROGRESS OF THE THUNDERSTORM COMPLEX. THEREFORE...OPTED TO DECREASE PRECIPITATION CHANCES SUBSTANTIALLY THROUGH 06Z. NORTH CENTRAL OKLAHOMA APPEARS TO HAVE THE MOST LIKELY CHANCE OF BEING INFLUENCED BY THE THUNDERSTORM COMPLEX. CONSEQUENTLY...INCREASED PRECIPITATION CHANCES ACROSS NORTH CENTRAL AND EAST CENTRAL OKLAHOMA AFTER 06Z. MAHALE && .PREV DISCUSSION... /ISSUED 250 PM CDT THU SEP 10 2015/ DISCUSSION... PRIMARY FORECAST CONCERN IS FOCUSED ON PRECIPITATION CHANCES TONIGHT THROUGH FRIDAY IN RESPONSE TO A COLD FRONT MOVING ACROSS THE AREA. CURRENTLY... 19Z SFC ANALYSIS PLACES THE COLD FRONT NEAR THE NE/KS BORDER... WITH INCREASING CU DEVELOPMENT ALONG AND AHEAD OF THE FRONT ACROSS NRN INTO CENTRAL KS. THIS FRONT WILL CONTINUE TO PUSH SOUTHWARD THROUGH THE AFTN INTO THE EVENING... APPROACHING THE OK/KS BORDER THROUGH THIS EVENING. CONTINUITY BETWEEN TRADITIONAL AND MESOSCALE GUIDANCE REMAINS DECENT. THE HRRR AND HIRES WRFS CONTINUE TO GENERATE CONVECTION WITH THE SFC TROUGH OVER THE PANHANDLES THROUGH 00Z... THE 12Z NAM IS A STEP SLOWER... BUT SIMILAR. GIVEN INCREASING DPTS THIS AFTN AND AN INCREASING ISENTROPIC RESPONSE INTO THE EVENING ACROSS NWRN OK... FELT COMFORTABLE TO INCREASE PRECIP CHCS IN THE NW BETWEEN 00-06Z. EXPECT PRECIP COVERAGE TO INCREASE INCREMENTALLY OVERNIGHT WITH THE BEST CHANCES AFTER MIDNIGHT THROUGH SUNRISE ACROSS NRN AND NERN OK. AS FOR SEVERE CHANCES... MODEST ML- CAPE VALUES 1000-1700 J/KG ARE POSSIBLE THIS EVENING AND OVERNIGHT... WITH 20 TO 30 KTS OF 0-6KM SHEAR. LOOKING AT BUFR SOUNDINGS... MOST OF THIS INSTABILITY IS WELL ELEVATED... WITH ANY STRONGER STORMS DEVELOPING A HAIL OR WIND THREAT... QUARTER TO HALF DOLLAR SIZE HAIL AND 60 MPH WINDS. OVERALL... THE CHANCE FOR SEVERE STORMS WILL RESIDE WITHIN A NARROW WINDOW OF TIME ACROSS NRN OK THIS EVENING THROUGH SUNSET. FRIDAY... SCATTERED SHOWERS AND THUNDERSTORMS WILL LIKELY BE ONGOING AROUND SUNRISE ACROSS NERN INTO CENTRAL OK. CHANCES WILL CONTINUE THROUGH THE AFTN ACROSS MUCH OF THE REGION AS THE COLD FRONT PUSHES TOWARDS THE RED RIVER THROUGH THE AFTN. INTO THE LATE AFTN/EVENING... SOME STEEPER LAPSE RATES MAY DEVELOP... RESULTING IN SOME STRONGER THUNDERSTORMS NEAR THE RED RIVER. HOWEVER... SEVERE CHANCES REMAIN LOW. SHOULD BE A WONDERFUL WEEKEND AS TEMPS REMAIN MILD... WITH HIGHS IN THE UPPER 70S AND LOWER 80S EACH DAY. TEMPS WILL START TO REBOUND EARLY NEXT WEEK AS SRLY FLOW RETURNS AND TROUGHING DEVELOPS OVER THE WRN US MON-TUE. OVERALL... THE FORECAST REMAINS DRY THROUGH MUCH OF NEXT WEEK... WITH THE NEXT BEST CHANCE FOR PRECIP LATE NEXT WEEK AS A FRONTAL BOUNDARY APPROACHES THE REGION. JTK && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 68 80 55 78 / 20 40 0 0 HOBART OK 68 81 58 81 / 10 30 10 0 WICHITA FALLS TX 70 87 59 83 / 10 30 10 0 GAGE OK 63 78 54 81 / 40 30 10 0 PONCA CITY OK 66 78 51 75 / 80 40 0 0 DURANT OK 71 87 59 81 / 0 40 10 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 10/09
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1031 PM EDT THU SEP 10 2015 .SYNOPSIS... A COLD FRONT AND UPPER TROUGH WILL SLOWLY SWEEP OVER THE SOUTHERN APPALACHIAN REGION LATE THIS WEEK. BY EARLY NEXT WEEK...A COOL AND DRY AIR MASS IS FORECAST TO SETTLE OVER THE WESTERN CAROLINAS AND NORTHEAST GEORGIA. MOISTURE SHOULD BEGIN TO INCREASE OVER THE REGION BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH FRIDAY/... 1015 PM UPDATE...ISOLATED CONVECTION CONTINUES ACROSS THE CHARLOTTE AREA INVOF A STALLED OUTFLOW BOUNDARY. AXIS OF SHORTWAVE TROUGH CAN BE SEEN ON WV IMAGERY...MORE OR LESS LINED UP WITH THE NC MTNS. ROUNDS OF WEAK ACTIVITY MAY FORM OVER THE NEXT COUPLE OF HOURS BUT INSTABILITY ALMOST CERTAINLY WILL BE USED UP BY THE TIME THE SHORTWAVE AXIS ARRIVES. MESO MODELS ARE NOT DOING MUCH AND THE HRRR IS TRENDING WEAKER WITH ITS DEPICTION OF NEW DEVELOPMENT OVER OUR AREA. A LINE OF CELLS OVER UPPER EAST TN IS MOVING SWD SLOWLY...BUT ARE NOT EXPECTED TO PUSH VERY FAR PAST THE NC BORDER. ALL REMAINING POPS ARE ISOLATED AND DIMINISH BELOW MENTIONABLE VALUES BY 200 A.M. ALREADY SEEING SOME LOWERING VSBYS ON AREA OBS...BUT STILL THINK THE THICKEST FOG WILL BE WHERE HEAVY RAIN FELL LATE IN THE DAY. REMAINDER OF PREVIOUS DISCUSSION...AS OF 225 PM...A COLD FRONT WAS ANALYZED WINDING FROM THE MID ATLANTIC TO THE TN VALLEY...TO THE SOUTHERN PLAINS. THE COLD FRONT WILL STALL IN THE MTNS FOR MUCH OF THE NIGHT...WHILE NWLY LLVL FLOW HELPS SCOUR OUT CLOUD COVER. SO PATCHY FOG AND STRATUS IS EXPECTED TO DEVELOP ACRS THE AREA...ESP WHERE THE HEAVIEST RAIN FALLS AND IN THE MTN VALLEYS. TEMPS WILL DROP A CATEGORY OR TWO COOLER THAN THIS MORNING/S LOWS FOR FRIDAY MORNING. FRIDAY...THE CWFA WILL BE IN BETWEEN SHORTWAVE TROFS AND BETWEEN SFC FRONTS. LLVL FLOW WILL REMAIN WLY TO NWLY...LIMITING MOISTURE AND LLVL CONVERGENCE. SO EXPECT ONLY ISOLATED TO WIDELY SCATTERED CONVECTION WITH PEAK HEATING FRIDAY AFTN. TEMPS WILL BE A CATEGORY OR TWO ABOVE NORMAL. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... AS OF 215 PM THURSDAY...LINGERING SCATTERED/ISOLATED DIURNAL CONVECTION IS EXPECTED TO WANE FRI EVENING...BUT POPS WILL INCREASE AGAIN TOWARD DAYBREAK ACROSS THE MTNS...AS A BAND OF DEEP MOISTURE ASSOCIATED WITH STRONG HEIGHT FALLS AND ASSOCIATED FRONTAL SURGE APPROACHES THE FORECAST AREA. WHILE THE MOIST BAND IS EXPECTED TO DIMINISH AS IT MOVES QUICKLY ACROSS THE FORECAST AREA DURING THE MORNING...MID-LEVEL DRY SLOT WILL OVERSPREAD THE AREA DURING THE AFTERNOON...WITH PART OF THE FRONT LIKELY GETTING HUNG UP A BIT ACROSS THE MOUNTAINS...LIKELY NOT COMPLETELY CLEARING THE AREA UNTIL A POTENT SHORT WAVE TROUGH MOVES ACROSS THE AREA DURING THE EVENING. AS A RESULT...THERE SHOULD BE PLENTY OF LOW LEVEL MOISTURE AND WARMTH LINGERING THROUGH THE DAY TO SUPPORT MODEST LEVELS OF INSTABILITY. TERRAIN EFFECTS AND THE FRONT SHOULD PROVIDE FOCI FOR SCATTERED CONVECTIVE DEVELOPMENT INTO THE AFTERNOON AND EARLY EVENING...ESP FROM THE BLUE RIDGE EAST...PRIMARILY WARRANTING CHANCE POPS. WITH CANADIAN HIGH PRESSURE BUILDING INTO THE REGION IN THE WAKE OF DEPARTING TROUGH/COLD FRONT...SUNDAY SHAPES UP TO BE A SPECTACULAR EARLY TASTE OF AUTUMN...WITH MAXES EXPECTED IN THE 70S AND DEWPOINTS LIKELY FALLING INTO THE 40S BY AFTERNOON. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 225 PM THURSDAY...THE EARLY PART OF THE MEDIUM RANGE WILL BE DOMINATED BY AN ANOMALOUSLY DEEP...YET PROGRESSIVE EAST COAST LONG WAVE TROUGH AND ASSOCIATED CANADIAN HIGH PRESSURE. THIS WILL SUPPORT A CONTINUATION OF EARLY FALL-LIKE WEATHER...WITH TEMPS/DEWPOINTS EXPECTED TO REMAIN BELOW CLIMO THROUGH AT LEAST TUESDAY. IN FACT... MON MORNING IS EXPECTED TO BE DOWNRIGHT CHILLY ACROSS THE HIGH ELEVATIONS...WITH TEMPS LIKELY DIPPING TO NEAR 40 ABOVE 4000 FEET OR SO. HEIGHT RISES BY THE END OF THE PERIOD WILL RESULT IN TEMPS CREEPING BACK TOWARD CLIMO...ALTHOUGH WITH SURFACE RIDGE AXIS EXPECTED TO PERSIST ACROSS THE REGION...DEWPOINTS SHOULD BE SLOWER TO RECOVER...AND IT APPEARS CHANCES FOR ANY DIURNAL CONVECTION...OR PRECIP OF ANY STRIPE WILL BE BELOW 20 PERCENT THROUGH THE PERIOD. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... AT KCLT...THE LATE DAY THUNDERSTORMS HAVE LIKELY ENSURED RESTRICTIONS WILL DEVELOP OVERNIGHT. SETUP IS SIMILAR TO LAST NIGHT...WITH SHIFTING LOW LEVEL WINDS ASSOCIATED WITH A PASSING TROUGH...ENHANCING CONVERGENCE. DRYING ALOFT WILL PROMOTE COOLING ATOP THE LOWER CLOUD LAYERS. DUE TO WET SOILS...SOME VSBY RESTRICTIONS MAY COME AND GO PARTICULARLY EARLIER IN THE NIGHT. WILL HAVE TO MONITOR OBS. A LESS ACTIVE DAY IS EXPECTED FRIDAY...WITH WEAKER LAPSE RATES AND POPS CURRENTLY LOW ENOUGH NOT TO WARRANT A MENTION FOR THE AFTN. SW WINDS RETURN FOLLOWING DEPARTURE OF TSRA THIS EVENING...THEN GO BRIEFLY N OF W AS TROUGH PASSES. THEY WILL EVENTUALLY BACK TO SW AGAIN FOR THE AFTN...AHEAD OF ANOTHER APPROACHING TROUGH. ELSEWHERE...CONVECTION SHOULD DIMINISH PRETTY QUICKLY THIS EVENING AND IS NOT EXPECTED TO AFFECT ANY TAF SITES. WITH ABUNDANT LLVL MOISTURE AND WITH SIMILAR FLOW PATTERN TO LAST NIGHT...IFR STRATUS AND FOG WILL PLAGUE PARTS OF THE AREA BY DAYBREAK. MTN VALLEYS INCLUDING KAVL APPEAR TO BE AT PARTICULARLY GREAT RISK OF IFR. THE ONLY OTHER SITE WHICH SAW HEAVY RAIN WAS KHKY...BUT GUIDANCE DOES NOT SUPPORT RESTRICTIONS THERE...POSSIBLY BECAUSE WIND SHIFT OCCURS EARLY ENOUGH. THUS IFR PREVAILS AT KAVL BUT TEMPO AT KHKY. EXCEPT AT KAVL WHICH REMAINS NW...WINDS WILL TREND SIMILAR TO KCLT AND WILL FAVOR SW EXCEPT WITH NW BEING MORE LIKELY IN THE EARLY PART OF FRI. OUTLOOK...UNSETTLED CONDITIONS WILL CONTINUE THROUGH THE WEEKEND AS A FRONT STALLS IN THE REGION...AND AN UPPER LEVEL LOW PRESSURE SYSTEM DRIFTS EAST THROUGH THE APPALACHIANS. MTN VALLEY FOG AND STRATUS ARE POSSIBLE EACH MORNING...WITH SCATTERED THUNDERSTORMS MAINLY IN THE AFTN. DRIER CONDITIONS WILL ARRIVE EARLY NEXT WEEK. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-00Z KCLT HIGH 100% MED 74% HIGH 100% LOW 25% KGSP HIGH 100% HIGH 95% HIGH 100% LOW 25% KAVL HIGH 90% MED 77% HIGH 93% LOW 25% KHKY HIGH 95% HIGH 100% HIGH 100% LOW 25% KGMU HIGH 100% HIGH 95% HIGH 100% LOW 25% KAND HIGH 100% HIGH 94% HIGH 100% LOW 25% 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 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...RWH NEAR TERM...ARK/WIMBERLEY SHORT TERM...JDL LONG TERM...JDL AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
ISSUED BY NATIONAL WEATHER SERVICE JACKSON MS 1020 AM CDT WED SEP 9 2015 .DISCUSSION...VISIBLE SATELLITE IMAGERY THIS MORNING SHOWED A DECK OF MOSTLY MID/HIGH CLOUDS STREAMING ACROSS SERN PORTIONS OF THE FORECAST AREA, WITH SUBSTANTIAL BREAKS ACROSS THE REMAINDER OF THE CWA. AS A RESULT, 15Z TEMPS RANGED FROM THE LOW-MID 80S IN AREAS SEEING MORE SUNSHINE TO MID-UPPER 70S OVER MUCH OF THE CUMBERLAND PLATEAU. ISOLATED SHOWERS WERE ONGOING NORTHEAST OF THE METRO AREA FROM PORTLAND TO AROUND CARTHAGE, HOWEVER MOST AREAS REMAIN DRY AT THIS POINT. HEADING THROUGH THE REMAINDER OF THE DAY, THE PRESENCE OF DEEP LAYER MOISTURE (1.82 IN PW NOTED ON 12Z OHX SOUNDING), DEVELOPING WEAK TO MODERATE INSTABILITY, AND AN APPROACHING COLD FRONT WILL PROVIDE INCREASING CONVECTIVE COVERAGE ACROSS THE REGION. THOUGH RELATIVELY WEAK DEEP LAYER SHEAR AND UNIMPRESSIVE LAPSE RATES WILL LIMIT THE THREAT OF STRONG STORMS, THUNDERSTORMS WILL BE POSSIBLE. SOME MINOR TWEAKS WERE MADE TO THE FORECAST TO INDICATE GREATER POPS THIS AFTERNOON THAN THIS MORNING. OTHERWISE, THE INHERITED FORECAST WAS ON TRACK AND NO OTHER ADJUSTMENTS WERE MADE. DL/JAN && .PREV DISCUSSION... /ISSUED 304 AM CDT WED SEP 9 2015/ SURFACE OBSERVATIONS THIS MORNING SHOW TEMPERATURES AND DEWPOINTS IN THE 66-73 DEGREE RANGE WHICH IS SEVERAL DEGREES HIGHER THAN YESTERDAY AT THIS TIME. CLOUD COVER IS ALSO INCREASING EARLY THIS MORNING AS DEEPER MOISTURE...CHARACTERIZED BY PWATS AROUND 1.85 INCHES PER 00Z RAOBS AT BHM AND ATL...CONTINUES TO ADVECT NORTHWESTWARD INTO THE MID STATE. IN FACT...LATEST RADAR IMAGERY SHOWS LIGHT SHOWERS ALREADY DEVELOPING ACROSS NORTH ALABAMA AND SOUTHERN TENNESSEE ON THE LEADING EDGE OF THIS DEEPER MOISTURE. LATEST HRRR MODEL GUIDANCE EXPANDS THIS ACTIVITY THROUGHOUT THE CWA LATER THIS MORNING INTO THE AFTERNOON...WHILE SHOWERS/STORMS CURRENTLY APPROACHING THE MISSISSIPPI RIVER ALSO SPREAD INTO THE AREA AS A UPPER TROUGH AXIS SHIFTS EASTWARD ACROSS THE TENNESSEE VALLEY. THUS WILL CONTINUE LIKELY POPS FOR ALL ZONES...WITH CLOUD COVER AND PRECIPITATION KEEPING HIGHS DOWN IN THE 80S TODAY. SHOWERS AND STORMS WILL CONTINUE INTO TONIGHT AS H5 TROUGH AXIS CONTINUES TO THE EAST...WITH ACTIVITY GRADUALLY SHIFTING SOUTHEAST OUT OF THE CWA FROM THURSDAY INTO THURSDAY NIGHT AS A WEAK COLD FRONT PUSHES SOUTHEASTWARD. A FEW SHOWERS AND MAYBE A THUNDERSTORM APPEAR POSSIBLE ON FRIDAY...BUT A BETTER CHANCE WILL ARRIVE FRIDAY NIGHT INTO SATURDAY AS THE FIRST STRONG COLD FRONT OF METEOROLOGICAL FALL ARRIVES. 00Z GFS/ECMWF CONTINUE TO TREND STRONGER WITH THE UPPER TROUGH THAT WILL FORCE THIS FRONT THROUGH THE AREA...SO HAVE NUDGED POPS UP A TAD FRIDAY NIGHT INTO SATURDAY. THE FIRST TASTE OF FALL IS THEN EXPECTED FOR THE REST OF THE WEEKEND...WITH GFS FINALLY CATCHING ON TO THE ECMWF IN SHOWING DRY WEATHER WITH SIGNIFICANTLY COOLER TEMPERATURES SOME 10 TO 15 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. BASED ON THE LATEST LOCAL MODEL BLEND...WHICH HAS BEEN PERFORMING QUITE WELL OVER THE PAST MONTH...HIGHS IN THE UPPER 60S AND 70S WITH LOWS IN THE UPPER 40S AND 50S ARE EXPECTED FOR SEVERAL DAYS FROM SUNDAY THROUGH AT LEAST TUESDAY. AFTER THAT TIME...MODELS DIFFER ON WHETHER A STRONG COASTAL TROUGH OR POSSIBLE TROPICAL CYCLONE DEVELOPS IN THE WESTERN GULF OF MEXICO...BUT IF THIS OCCURS MOISTURE FROM THIS SYSTEM COULD SPREAD NORTHWARD INTO THE AREA LATER NEXT WEEK. SHAMBURGER && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 86 70 83 66 / 60 60 50 20 CLARKSVILLE 85 68 82 63 / 60 60 30 10 CROSSVILLE 80 66 77 63 / 70 60 60 40 COLUMBIA 86 68 81 64 / 60 60 60 20 LAWRENCEBURG 86 68 82 65 / 60 60 60 20 WAVERLY 85 68 83 64 / 60 60 40 20 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
304 AM CDT WED SEP 9 2015 .DISCUSSION... SURFACE OBSERVATIONS THIS MORNING SHOW TEMPERATURES AND DEWPOINTS IN THE 66-73 DEGREE RANGE WHICH IS SEVERAL DEGREES HIGHER THAN YESTERDAY AT THIS TIME. CLOUD COVER IS ALSO INCREASING EARLY THIS MORNING AS DEEPER MOISTURE...CHARACTERIZED BY PWATS AROUND 1.85 INCHES PER 00Z RAOBS AT BHM AND ATL...CONTINUES TO ADVECT NORTHWESTWARD INTO THE MID STATE. IN FACT...LATEST RADAR IMAGERY SHOWS LIGHT SHOWERS ALREADY DEVELOPING ACROSS NORTH ALABAMA AND SOUTHERN TENNESSEE ON THE LEADING EDGE OF THIS DEEPER MOISTURE. LATEST HRRR MODEL GUIDANCE EXPANDS THIS ACTIVITY THROUGHOUT THE CWA LATER THIS MORNING INTO THE AFTERNOON...WHILE SHOWERS/STORMS CURRENTLY APPROACHING THE MISSISSIPPI RIVER ALSO SPREAD INTO THE AREA AS A UPPER TROUGH AXIS SHIFTS EASTWARD ACROSS THE TENNESSEE VALLEY. THUS WILL CONTINUE LIKELY POPS FOR ALL ZONES...WITH CLOUD COVER AND PRECIPITATION KEEPING HIGHS DOWN IN THE 80S TODAY. SHOWERS AND STORMS WILL CONTINUE INTO TONIGHT AS H5 TROUGH AXIS CONTINUES TO THE EAST...WITH ACTIVITY GRADUALLY SHIFTING SOUTHEAST OUT OF THE CWA FROM THURSDAY INTO THURSDAY NIGHT AS A WEAK COLD FRONT PUSHES SOUTHEASTWARD. A FEW SHOWERS AND MAYBE A THUNDERSTORM APPEAR POSSIBLE ON FRIDAY...BUT A BETTER CHANCE WILL ARRIVE FRIDAY NIGHT INTO SATURDAY AS THE FIRST STRONG COLD FRONT OF METEOROLOGICAL FALL ARRIVES. 00Z GFS/ECMWF CONTINUE TO TREND STRONGER WITH THE UPPER TROUGH THAT WILL FORCE THIS FRONT THROUGH THE AREA...SO HAVE NUDGED POPS UP A TAD FRIDAY NIGHT INTO SATURDAY. THE FIRST TASTE OF FALL IS THEN EXPECTED FOR THE REST OF THE WEEKEND...WITH GFS FINALLY CATCHING ON TO THE ECMWF IN SHOWING DRY WEATHER WITH SIGNIFICANTLY COOLER TEMPERATURES SOME 10 TO 15 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. BASED ON THE LATEST LOCAL MODEL BLEND...WHICH HAS BEEN PERFORMING QUITE WELL OVER THE PAST MONTH...HIGHS IN THE UPPER 60S AND 70S WITH LOWS IN THE UPPER 40S AND 50S ARE EXPECTED FOR SEVERAL DAYS FROM SUNDAY THROUGH AT LEAST TUESDAY. AFTER THAT TIME...MODELS DIFFER ON WHETHER A STRONG COASTAL TROUGH OR POSSIBLE TROPICAL CYCLONE DEVELOPS IN THE WESTERN GULF OF MEXICO...BUT IF THIS OCCURS MOISTURE FROM THIS SYSTEM COULD SPREAD NORTHWARD INTO THE AREA LATER NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 86 70 83 66 / 60 60 50 20 CLARKSVILLE 85 68 82 63 / 60 60 30 10 CROSSVILLE 80 66 77 63 / 70 60 60 40 COLUMBIA 86 68 81 64 / 60 60 60 20 LAWRENCEBURG 86 68 82 65 / 60 60 60 20 WAVERLY 85 68 83 64 / 60 60 40 20 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHAMBURGER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
951 PM CDT THU SEP 10 2015 .DISCUSSION... WILL KEEP THE FORECAST AS IS THIS EVENING. LOOK FOR POSSIBLE SHOWER/ THUNDERSTORM DEVELOPMENT MAINLY TOWARD THE COAST IN THE MORNING WITH ACTIVITY DEVELOPING FURTHER INLAND DURING THE DAY. TOMORROW`S CHANCE FOR STORMS LOOKS BEST NEAR THE COAST WITH THE LOWER VALUES INLAND... JUST AS THE CURRENT FORECAST SAYS. LOCALLY HEAVY RAINFALL IS POSSIBLE ONCE AGAIN TOMORROW WITH HIGH PRECIPITABLE WATER VALUES STILL ACROSS THE AREA. SIMILAR TO TODAY...WOULD NOT BE SURPRISED TO SEE 1 TO 2 INCH TOTALS WITH ISOLATED SPOTS GETTING INTO A 2 TO 4 INCH RANGE. LOCALIZED FLOODING WILL ONCE AGAIN BE POSSIBLE WITH THESE NUMBERS. 42 && .PREV DISCUSSION... AVIATION... CONVECTION DYING OUT OVER THE NEXT HOUR...SCATTERED LOW TO MID LEVEL DECKS SHOULD CLEAR OUT TO SKC OR SCT250 BY 03Z. VERY BRIEF PERIODS OF INTERIOR RURAL MVFR DECKS AT...OR SHORTLY AFTER...SUNRISE. RETURNING SHOWERS WITH ISOLATED STORMS CLOSER TO THE COAST DURING DAYLIGHT MORNING HOURS...TRANSITIONING TO MORE WIDESPREAD RAIN AND NUMEROUS CLUSTERED STORMS FROM AROUND 17Z THROUGH 22-23Z. SIMILAR LARGE SCALE SETUP WITH BROAD WEAK TOUGHING OVER THE STATE...ENOUGH LOWER LEVEL MOISTURE AND INSTABILITY TO COMMENCE CONVECTION ONCE MID 80S SURFACE TEMPERATURES ARE MET. 31 PREV DISCUSSION... DISCUSSION... RADAR THIS AFTERNOON SHOWS WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY WITH THE STRONGEST STORMS OVER E HARRIS COUNTY WHERE STORMS ARE PRODUCING RAIN RATES OF 2 INCHES AN HOUR. THERE IS ALSO A BAND OF ACTIVITY ALONG A STALLED FRONTAL BOUNDARY FROM AUSTIN TO COLLEGE STATION EAST TO JASPER. LATEST TRENDS WITH THE HRRR MODEL SEEM TO SHOW ACTIVITY ENDING BETWEEN 00-03Z THIS EVENING. WATER VAPOR IMAGE LOOP SHOWS A WEAK JET STREAK/SHORTWAVE PUSHING THROUGH THE REGION THIS AFTERNOON WHICH MAY BE HELPING TO ENHANCE CONVECTION. OVERALL UPPER LEVEL PATTERN IS ON TRACK WITH A STRONGER SHORTWAVE TROUGH DEVELOPING OVER THE N ROCKIES WHICH WILL HELP AMPLIFY THE TROUGH FROM SW OF HUDSON BAY TO THE UPPER MIDWEST TONIGHT INTO FRIDAY. WITH PRECIP WATER VALUES OVER 2 INCHES TOMORROW AND FAVORABLE UPPER LEVEL PATTERN...FORECAST WILL HOLD ONTO 60/70 POPS. GFS/NAM/ECMWF ALL SUPPORT SHOWER AND THUNDERSTORM ACTIVITY SIMILAR TO TODAY`S ACTIVITY. THERE WILL ALSO BE AN ADDED TROUGH AXIS THAT PUSHES THROUGH FRI TO HELP INCREASE LARGE SCALE LIFT. AS HAS BEEN THE CASE TODAY...EXPECTING A GENERAL 1 TO 2 INCHES OF RAIN WITH ISOLATED HIGHER AMOUNTS. SINCE CONVECTION WILL BE PULSE TYPE...VERY WELL COULD HAVE AREAS THAT GET NO RAINFALL BUT THEN AREAS THAT GET TOO MUCH. THERE MAY BE FLOODING ASSOCIATED WITH ANY OF THE HIGHER AMOUNTS BUT A WIDESPREAD FLOOD THREAT IS NOT EXPECTED AT THIS TIME. GIVEN THE MORE AMPLIFIED PATTERN FRIDAY INTO SATURDAY...COLD FRONT WILL BE PUSHING THROUGH THE AREA AND OFF THE COAST. LATEST TIMING FROM THE NAM/GFS/ECMWF SHOWS IT REACHING COLLEGE STATION TO HUNTSVILLE AROUND 1-3AM SATURDAY...REACHING HOUSTON CLOSER TO 6-8AM AND OFF THE COAST BEFORE NOON SATURDAY. WINDS SHOULD SHIFT TO THE N/NE. THE MUCH DRIER COOLER AIRMASS WILL LIKELY LAG BEHIND THE FRONT AND NOT ARRIVE UNTIL LATER IN THE AFTERNOON AND OVERNIGHT. THERE DOES NOT APPEAR TO BE MUCH OF A CHANCE OF THUNDERSTORMS WITH THE FRONT BUT GIVEN THE MOISTURE CONTENT WILL AT LEAST HAVE A 30 PERCENT IN THE FORECAST. WEATHER CONDITIONS SUNDAY/MONDAY WILL CERTAINLY GIVE EVERYONE A GOOD TASTE OF FALL WEATHER WITH LOW TEMPS IN THE LOW 60S...PERHAPS UPPER 50S FOR AREAS NORTH OF HOUSTON. HIGH TEMPERATURES WILL BE IN THE MID 80S. ENJOY IT WHILE YOU CAN BECAUSE THE MOISTURE SHOULD BE BACK TUESDAY THROUGH THURSDAY NEXT WEEK. EXTENDED FORECAST...STILL VERY UNCERTAIN WITH REGARDS TO A SURGE OF TROPICAL MOISTURE EXPECTED TO PUSH INTO THE AREA TUESDAY AND WEDNESDAY. GFS HAS BEEN VERY CONSISTENT AND HAS HAD ENSEMBLE SUPPORT OF MAINLY A SURFACE COASTAL TROUGH DEVELOPING IN THE W GULF AND PUSHING NORTH TOWARDS THE AREA. THE ECMWF THE LAST 2 RUNS HAS NOW TAPPED THE BREAKS ON TROPICAL CYCLONE FORMATION ALTHOUGH IT STILL WANTS TO DEVELOP SOME TYPE OF LOW PRESSURE WHICH IT SLOWLY PUSHES TOWARDS THE LOWER TEXAS COAST NEXT WEEK. GFS CONTINUES TO HOLD ONTO SOME W SHEAR ACROSS THE N GULF WITH THE ECMWF STILL HAVING SOMEWHAT OF A RIDGE. THE DIFFERENCES IN THE PATTERNS WILL LIKELY DETERMINE HOW MUCH SHEAR DEVELOPS OVER THE NW GULF AND IF THERE IS ANY DEVELOPMENT. AT THIS POINT IT DOES NOT LOOK LIKELY BUT WE WILL STILL NEED TO MONITOR FORECAST DATA. 39 MARINE... NOT TOO MANY CHANGES WITH THE SHORT TERM PART OF THE FCST AS MOSTLY LIGHT ONSHORE WINDS PREVAIL...ALONG WITH THE WIDESPREAD STORMS THRU TOMORROW(FRI). MODELS STILL IN DECENT AGREEMENT WITH THE PASSAGE OF A WEAK COLD FRONT INTO THE COASTAL WATERS EARLY SAT MORNING. GENERALLY LIGHT/MODERATE NE WINDS TO DEVELOP IN ITS WAKE...FROM SAT AFTN INTO SUN MORNING. AS THIS FRONT DISSIPATES OVER THE GULF AND A WEAK TROF OF LOW PRESSURE BEGINS TO DEVELOP NEAR THE LOWER TX COAST...WE SHOULD START SEEING A MORE EASTERLY FETCH DEVELOP OVER THE UPPER TX COAST SUN AFTN/EVE. THIS FEATURE WILL THEN HELP TO BRING PERIODS OF SHRA/TSRA AND PERHAPS A PROLONGED PERIOD OF ESE WINDS TO THE REGION FOR THE FIRST HALF OF NEXT WEEK. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 74 89 71 86 61 / 30 40 30 10 10 HOUSTON (IAH) 74 87 71 86 62 / 40 60 30 20 10 GALVESTON (GLS) 78 84 76 86 72 / 50 70 50 30 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...42 AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
706 PM CDT THU SEP 10 2015 .AVIATION... CONVECTION DYING OUT OVER THE NEXT HOUR...SCATTERED LOW TO MID LEVEL DECKS SHOULD CLEAR OUT TO SKC OR SCT250 BY 03Z. VERY BRIEF PERIODS OF INTERIOR RURAL MVFR DECKS AT...OR SHORTLY AFTER...SUNRISE. RETURNING SHOWERS WITH ISOLATED STORMS CLOSER TO THE COAST DURING DAYLIGHT MORNING HOURS...TRANSITIONING TO MORE WIDESPREAD RAIN AND NUMEROUS CLUSTERED STORMS FROM AROUND 17Z THROUGH 22-23Z. SIMILAR LARGE SCALE SETUP WITH BROAD WEAK TOUGHING OVER THE STATE...ENOUGH LOWER LEVEL MOISTURE AND INSTABILITY TO COMMENCE CONVECTION ONCE MID 80S SURFACE TEMPERATURES ARE MET. 31 && .PREV DISCUSSION... DISCUSSION... RADAR THIS AFTERNOON SHOWS WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY WITH THE STRONGEST STORMS OVER E HARRIS COUNTY WHERE STORMS ARE PRODUCING RAIN RATES OF 2 INCHES AN HOUR. THERE IS ALSO A BAND OF ACTIVITY ALONG A STALLED FRONTAL BOUNDARY FROM AUSTIN TO COLLEGE STATION EAST TO JASPER. LATEST TRENDS WITH THE HRRR MODEL SEEM TO SHOW ACTIVITY ENDING BETWEEN 00-03Z THIS EVENING. WATER VAPOR IMAGE LOOP SHOWS A WEAK JET STREAK/SHORTWAVE PUSHING THROUGH THE REGION THIS AFTERNOON WHICH MAY BE HELPING TO ENHANCE CONVECTION. OVERALL UPPER LEVEL PATTERN IS ON TRACK WITH A STRONGER SHORTWAVE TROUGH DEVELOPING OVER THE N ROCKIES WHICH WILL HELP AMPLIFY THE TROUGH FROM SW OF HUDSON BAY TO THE UPPER MIDWEST TONIGHT INTO FRIDAY. WITH PRECIP WATER VALUES OVER 2 INCHES TOMORROW AND FAVORABLE UPPER LEVEL PATTERN...FORECAST WILL HOLD ONTO 60/70 POPS. GFS/NAM/ECMWF ALL SUPPORT SHOWER AND THUNDERSTORM ACTIVITY SIMILAR TO TODAY`S ACTIVITY. THERE WILL ALSO BE AN ADDED TROUGH AXIS THAT PUSHES THROUGH FRI TO HELP INCREASE LARGE SCALE LIFT. AS HAS BEEN THE CASE TODAY...EXPECTING A GENERAL 1 TO 2 INCHES OF RAIN WITH ISOLATED HIGHER AMOUNTS. SINCE CONVECTION WILL BE PULSE TYPE...VERY WELL COULD HAVE AREAS THAT GET NO RAINFALL BUT THEN AREAS THAT GET TOO MUCH. THERE MAY BE FLOODING ASSOCIATED WITH ANY OF THE HIGHER AMOUNTS BUT A WIDESPREAD FLOOD THREAT IS NOT EXPECTED AT THIS TIME. GIVEN THE MORE AMPLIFIED PATTERN FRIDAY INTO SATURDAY...COLD FRONT WILL BE PUSHING THROUGH THE AREA AND OFF THE COAST. LATEST TIMING FROM THE NAM/GFS/ECMWF SHOWS IT REACHING COLLEGE STATION TO HUNTSVILLE AROUND 1-3AM SATURDAY...REACHING HOUSTON CLOSER TO 6-8AM AND OFF THE COAST BEFORE NOON SATURDAY. WINDS SHOULD SHIFT TO THE N/NE. THE MUCH DRIER COOLER AIRMASS WILL LIKELY LAG BEHIND THE FRONT AND NOT ARRIVE UNTIL LATER IN THE AFTERNOON AND OVERNIGHT. THERE DOES NOT APPEAR TO BE MUCH OF A CHANCE OF THUNDERSTORMS WITH THE FRONT BUT GIVEN THE MOISTURE CONTENT WILL AT LEAST HAVE A 30 PERCENT IN THE FORECAST. WEATHER CONDITIONS SUNDAY/MONDAY WILL CERTAINLY GIVE EVERYONE A GOOD TASTE OF FALL WEATHER WITH LOW TEMPS IN THE LOW 60S...PERHAPS UPPER 50S FOR AREAS NORTH OF HOUSTON. HIGH TEMPERATURES WILL BE IN THE MID 80S. ENJOY IT WHILE YOU CAN BECAUSE THE MOISTURE SHOULD BE BACK TUESDAY THROUGH THURSDAY NEXT WEEK. EXTENDED FORECAST...STILL VERY UNCERTAIN WITH REGARDS TO A SURGE OF TROPICAL MOISTURE EXPECTED TO PUSH INTO THE AREA TUESDAY AND WEDNESDAY. GFS HAS BEEN VERY CONSISTENT AND HAS HAD ENSEMBLE SUPPORT OF MAINLY A SURFACE COASTAL TROUGH DEVELOPING IN THE W GULF AND PUSHING NORTH TOWARDS THE AREA. THE ECMWF THE LAST 2 RUNS HAS NOW TAPPED THE BREAKS ON TROPICAL CYCLONE FORMATION ALTHOUGH IT STILL WANTS TO DEVELOP SOME TYPE OF LOW PRESSURE WHICH IT SLOWLY PUSHES TOWARDS THE LOWER TEXAS COAST NEXT WEEK. GFS CONTINUES TO HOLD ONTO SOME W SHEAR ACROSS THE N GULF WITH THE ECMWF STILL HAVING SOMEWHAT OF A RIDGE. THE DIFFERENCES IN THE PATTERNS WILL LIKELY DETERMINE HOW MUCH SHEAR DEVELOPS OVER THE NW GULF AND IF THERE IS ANY DEVELOPMENT. AT THIS POINT IT DOES NOT LOOK LIKELY BUT WE WILL STILL NEED TO MONITOR FORECAST DATA. 39 && MARINE... NOT TOO MANY CHANGES WITH THE SHORT TERM PART OF THE FCST AS MOSTLY LIGHT ONSHORE WINDS PREVAIL...ALONG WITH THE WIDESPREAD STORMS THRU TOMORROW(FRI). MODELS STILL IN DECENT AGREEMENT WITH THE PASSAGE OF A WEAK COLD FRONT INTO THE COASTAL WATERS EARLY SAT MORNING. GENERALLY LIGHT/MODERATE NE WINDS TO DEVELOP IN ITS WAKE...FROM SAT AFTN INTO SUN MORNING. AS THIS FRONT DISSIPATES OVER THE GULF AND A WEAK TROF OF LOW PRESSURE BEGINS TO DEVELOP NEAR THE LOWER TX COAST...WE SHOULD START SEEING A MORE EASTERLY FETCH DEVELOP OVER THE UPPER TX COAST SUN AFTN/EVE. THIS FEATURE WILL THEN HELP TO BRING PERIODS OF SHRA/TSRA AND PERHAPS A PROLONGED PERIOD OF ESE WINDS TO THE REGION FOR THE FIRST HALF OF NEXT WEEK. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 74 89 71 86 61 / 30 40 30 10 10 HOUSTON (IAH) 74 87 71 86 62 / 40 60 30 20 10 GALVESTON (GLS) 78 84 76 86 72 / 50 70 50 30 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...42 AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
657 PM CDT THU SEP 10 2015 .AVIATION... BIGGEST CONCERNS THIS CYCLE REVOLVE AROUND A FRONTAL PASSAGE AND THUNDER CHANCES...BOTH OF WHICH THE TIMING IS SOMEWHAT UNCERTAIN. LIGHT SOUTHEASTERLY BREEZES AND VFR CONDITIONS WILL PREVAIL THIS EVENING. ATTENTION WILL THEN TURN TO THE NORTH AS CONVECTION CURRENTLY STRETCHING FROM NORTHEAST NEW MEXICO INTO SOUTHWEST KANSAS WILL PROPAGATE SOUTHEASTWARD. IT IS UNCLEAR IF THIS ACTIVITY WILL BE ABLE TO MAINTAIN ITSELF WELL INTO THE NIGHT...BUT IF IT DOES IT COULD AFFECT THE NORTHERN TERMINALS AFTER MIDNIGHT. CONFIDENCE IN THIS IS LOW...SO IT HAS BEEN LEFT OUT OF THE TAFS ATTM. EVENTUALLY...A NORTHEASTERLY WIND SHIFT WILL TRAVERSE THE TERMINALS SOMETIME FRIDAY MORNING AS A CONVECTIVELY AIDED COLD FRONT MOVES THROUGH. THIS FROPA WILL BOOST STORM CHANCES IN ITS WAKE FOR SEVERAL HOURS AT EACH TERMINAL BEFORE CHANCES WANE TOWARD EVENING. A PROB30 GROUP WAS INCLUDED TO OUTLINE THE MOST LIKELY WINDOW FOR CONVECTION AT EACH OF THE TERMINALS. IN ADDITION TO STORM CHANCES...BREEZY NORTHEASTERLY WINDS WILL FOLLOW THE FRONT WITH SOME RISK OF LOW CLOUD DEVELOPMENT WELL BEHIND THE FROPA. && .PREV DISCUSSION... /ISSUED 304 PM CDT THU SEP 10 2015/ SHORT TERM... A PROMINENT FEATURE IN THE WEATHER TODAY HAS BEEN A BAND OF CIRRUS ARCING FROM CENTRAL ARIZONA ACROSS WEST TEXAS. THIS IS ASSOCIATED WITH SOME TROPICAL MOISTURE CAUGHT UP IN THE CIRCULATION OF DECAYING TROPICAL STORM LINDA OFF THE WEST COAST OF BAJA. UPPER-AIR ANALYSIS SHOWS THAT THIS MOISTURE IS LIMITED TO THE UPPER TROPOSPHERE WITH MID-LEVELS REMAINING FAIRLY DRY AND UNSUPPORTIVE OF ANY CONVECTIVE DEVELOPMENT. HOWEVER...WE ARE SEEING SOME DEVELOPMENT ACROSS NORTH- CENTRAL NEW MEXICO IN VICINITY OF THE RATON MESA. NORTHWEST FLOW ALOFT WILL CARRY THIS ACTIVITY TO THE SOUTHEAST THIS EVENING TOWARD THE FAR SOUTHWEST TEXAS PANHANDLE ASSUMING IT SURVIVES THE TREK ACROSS THE NORTHEAST NEW MEXICO PLAINS. THE HRRR IS ABOUT THE THE ONLY MODEL THAT INDICATES THIS...BUT WE WILL MAINTAIN A SLIGHT CHANCE MENTION ACROSS MUCH OF THE SRN TX PANHANDLE BETWEEN 00 AND 06 UTC TO ACCOUNT FOR THIS POSSIBILITY. BETTER T-STORM/RAIN CHANCES SHOULD ARRIVE EARLY FRIDAY MORNING AS A FAIRLY SHARP COLD FRONT MOVES IN FROM THE NORTH IN CONJUNCTION WITH A GLANCING BLOW FROM A SHORTWAVE MOVING SOUTHEAST THROUGH THE PLAINS. THE FRONT IS CURRENTLY MOVING INTO NORTHERN KANSAS AND THERE IS SOME UNCERTAINTY REGARDING IT/S TIMING INTO OUR FORECAST AREA OWING TO THE IMPACT OF CONVECTIVE OUTFLOWS ON THE FRONT. IN ADDITION...IT IS UNCERTAIN WHETHER OR NOT THE FRONTOGENETIC FORCING WILL SYNCH UP WITH THE BEST LARGE-SCALE ASCENT ASSOCIATED WITH THE PASSING WAVE. FINALLY...THE TIMING OF THE FRONT...PASSING THROUGH THE AREA ROUGHLY BETWEEN 12 UTC AND 18 UTC...IS NOT OPTIMAL FOR THE GENERATION OF INSTABILITY AVAILABLE FOR CONVECTION. WITH THIS IN MIND...WE HAVE KEPT POPS IN THE CHANCE CATEGORY FOR THE AREA ON FRIDAY AS THE LINGERING UNCERTAINTY DOES LEND ITSELF FOR LIKELY OR CATEGORICAL POPS. IN GENERAL...GUIDANCE FAVORS A BROAD ZONE OR CLUSTER OF ALONG AND POST- FRONTAL SHOWERS AND THUNDERSTORMS FRIDAY MORNING FOLLOWING THE FRONT FROM NORTHEAST TO SOUTHWEST....AND GRADUALLY TAPERING OFF FROM THE NORTHEAST DURING THE AFTERNOON. BREEZY NORTHEAST WINDS WILL DEVELOP BEHIND THE FRONT AND LAST THROUGH THE AFTERNOON. TEMPERATURES WILL BE MARKEDLY COOLER ACROSS THE NORTH...WITH HIGHS IN THE MID TO UPPER 70S ACROSS THE FAR SW TEXAS PANHANDLE AND NORTHERN SOUTH PLAINS. DEPENDING ON THE TIMING OF THE FRONT...WE MAY STILL STILL SOME HIGH TEMPS REACH 90 DOWN IN THE SOUTHERN ROLLING PLAINS. LONG TERM... MID-LEVEL DRYING WILL ADVANCE SLOWLY SW BY FRIDAY EVENING IN THE WAKE OF THE 850-700 MB COLD FRONT. THE DRIEST SURFACE RIDGING WILL LAG UNTIL SATURDAY MORNING...SO POST-FRONTAL STRATUS AIDED BY E-NE WINDS SHOULD LINGER ESPECIALLY ON THE CAPROCK BEFORE ERODING BY MIDDAY SAT. SOME OF THIS STRATUS IS PROGGED TO BE SUFFICIENTLY THICK FRI NIGHT THAT A FEW SHOWERS COULD MATERIALIZE FROM WEAK FN FORCING ALONG THE AFOREMENTIONED ELEVATED FRONTAL LAYER...BUT POPS OVERALL WERE SKIMMED BACK EVEN FURTHER THAN BEFORE. SAT MORNING WILL SEE SURFACE WINDS VEER SELY BEHIND THE PROGRESSIVE SURFACE RIDGE AND THIS PROCESS WILL AID IN WEAK ISENTROPIC LIFT ACROSS THE WESTERN HALF OF THE CWA COINCIDENT WITH A MODEST AXIS OF HIGHER PWATS. WHILE SATURATED DEPTHS ARE NOT MUCH TO WRITE ABOUT... THE BRUNT OF THIS SATURATION IS BELOW 700 MB WHICH COULD BE WRUNG OUT IN THE FORM OF SPRINKLES OR EVEN DRIZZLE PROVIDED STRATUS CAN DESCEND LOW ENOUGH AT TIMES. CLEARING SKIES BY MIDDAY COULD OPEN THE DOOR TO WEAK CAPE ACROSS EASTERN NM UNDERNEATH 10-20 KNOTS OF NW FLOW...HOWEVER NO DISCERNIBLE BACKGROUND SUPPORT PRECLUDES FURTHER POPS AT THIS TIME. EVEN WITH CLEARING...BELOW NORMAL HIGHS REMAIN ON TRACK GIVEN OUR PROXIMITY TO THE SURFACE RIDGE. THIS COOL THEME WILL BE SHORT LIVED AS SUNDAY AND BEYOND FEATURE LEE TROUGHING BENEATH AMPLIFYING SW FLOW. SIDED CLOSE TO THE WARMEST MEX AND ECE MOS HIGHS NEXT WEEK AS THIS LOOKS TO BE A VERY DRY AND BREEZY PATTERN FOR WEST TX. SUCH DRY SOILS IN THIS SETUP ARGUE IN FAVOR OF A RATHER STRONG DIURNAL TEMP RANGE...SO LOWS WERE NUDGED BELOW THE MILD SUPERBLEND VALUES. A SMALL WINDOW FOR MID-LEVEL MOISTENING MAY UNFOLD NEAR MIDWEEK AS A BROAD TROUGH LIFTS NORTHEAST OUT OF THE FOUR CORNERS. MONSOONAL MOISTURE ALOFT WILL LIKELY BE THINNED OUT BY THIS TIME...BUT SOME UPTICK IN PWATS MAY BE REALIZED BY TUE AND WED AS THE SW FLOW TURNS WEAKLY CYCLONIC. WHETHER THIS RESULTS IN PRECIP ALONG A DRYLINE IN/NEAR OUR AREA IS TOO UNCERTAIN...ESPECIALLY WITH OUR REGION RESIDING LARGELY SOUTH OF THE UPPER JET MAXIMA. LUB WATCHES/WARNINGS/ADVISORIES... NONE. $$ && .PRELIMINARY POINT TEMPS/POPS... FRIONA 60 76 55 76 / 20 50 20 10 TULIA 62 77 55 77 / 20 50 10 10 PLAINVIEW 62 79 55 77 / 20 40 10 10 LEVELLAND 62 82 56 76 / 10 40 20 10 LUBBOCK 63 82 57 77 / 10 40 20 10 DENVER CITY 63 85 58 77 / 10 40 30 10 BROWNFIELD 63 84 57 77 / 10 40 20 10 CHILDRESS 68 82 59 81 / 10 40 10 0 SPUR 66 85 58 79 / 10 40 10 0 ASPERMONT 69 90 60 82 / 10 40 10 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
648 PM CDT THU SEP 10 2015 .DISCUSSION...NOTE AVIATION DISCUSSION BELOW. && .AVIATION...PREDOMIANTE VFR OVER SOUTH TEXAS THIS EVENING NOTWITHSTANDING ISOLD/SCT SHOWERS/THUNDERSTORMS GENERALLY WEST OF U.S. ROUTE 281. ANTICIPATE GENERALLY RAIN FREE OVERNIGHT WITH MVFR CEILINGS DEVELOPING. EXPECT SCATTERED SHOWER/THUNDERSTORM ACTIVITY WITH MVFR CEILINGS/VISIBILITIES TO DEVELOP NEAR THE COAST AFTER 09Z FRIDAY WITH ACTIVITY INCREASING IN COVERAGE OVER THE COASTAL BEND/VICTORIA CROSSROADS DRG THE LATE MORNING/EARLY AFTN FRIDAY THEN OVER THE REMAINDER OF SOUTH TEXAS. GENERALLY LGT ONSHORE FLOW OVERNIGHT THROUGH FRIDAY MORNING THEN BECOMING MODERATE ONSHORE. && .PREV DISCUSSION... /ISSUED 334 PM CDT THU SEP 10 2015/ SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...ABUNDANT MOISTURE WITH OVER 2 INCH PWATS REMAINS OVER SOUTH TEXAS WITH SCATTERED CONVECTION ONGOING...WITH CONVECTION EXPECTED TO DWINDLE THROUGH THE EVENING. CHALLENGE GOES INTO TIMING OF CONVECTION FOR FRIDAY. TEXAS TECH WRF AND HRRR BOTH HAVE HAD A PRETTY GOOD HOLD CONVECTION TODAY...AND LOOKING AT WHAT THEY SHOW FOR FRIDAY...THEY KEEP A MUCH SLOWER TREND FOR CONVECTION...WITH THINGS MOSTLY DRY THROUGH MID MORNING FRIDAY. DUE TO AN INCREASE IN H925 FLOW AND A SHORTWAVE MOVING SOUTH ALONG THE RIO GRANDE OVERNIGHT KEPT IN POPS FOR TONIGHT...BUT DUE TO A BIT OF SUBSIDENCE AHEAD OF THE SOUTHWARD PROGRESSING TROUGH...DID CUT BACK FROM PREVIOUS FORECAST PACKAGE. CHANCES FOR RAIN WILL INCREASE THROUGH THE DAY...WITH THE BEST TIMING MORE DURING THE AFTERNOON THROUGH OVERNIGHT HOURS...DUE TO MORE CONVERGENCE AND INCREASED LIFT WITH THE TROUGH SHIFTING SOUTH. AS FOR TEMPERATURES...TRENDED ON THE COOLER SIDE FROM THE EXPECTED CLOUD COVERAGE AND RAIN CHANCES. LONG TERM (SATURDAY THROUGH THURSDAY)...THE MODELS ARE FAIRLY CONSISTENT IN PUSHING A COLD FRONT THROUGH THE CWA BY SATURDAY NIGHT. SUFFICIENT MOISTURE/INSTABILITY AND KINEMATIC FORCING WL EXIST ALONG AND AHEAD OF THE FRONT TO MAINTAIN SLIGHT CHC TO CHC POPS ON SATURDAY. DRY AIR ADVECTION AIDED BY A WK TO MODERATE NORTHEAST FLOW WL PRODUCE ABUNDANT SUNSHINE AND MUCH LOWER HUMIDITIES FOR SUNDAY. THE ECMWF 12Z SOLUTION HAS NOW COME MORE IN LINE WITH THE WEAKER GFS REFLECTION OF THE AREA OF LOW PRESSURE THAT MAY DEVELOP OVER THE SW GULF BY SUNDAY AND MONDAY. THE CURRENT THINKING IS THAT THIS SYSTEM WL REMAIN WK AND REMAIN TO OUR SOUTH POSSIBLY MOVING INTO NORTHERN MEXICO NEAR TAMPICO BY TUESDAY. THE NET EFFECT WL LKLY BE TO KEEP MOST OF THE DEEP TROPICAL MOISTURE TO THE SOUTH. HOWEVER...DO EXPECT MOISTURE TRANSPORT NEXT WEEK AS THE BOUNDARY LAYER FLOW BECOMES MORE SOUTHEASTERLY BY MONDAY. THERE WL LKLY BE SUFFICIENT MOISTURE TO WARRANT SLIGHT CHC TO CHC POPS FOR MOSTLY THE WATERS AND COASTAL BEND FROM LATE MONDAY THROUGH THURSDAY. OVERALL DID TRIM THESE POPS BACK FOR NEXT WEEK FROM PRIOR REASONING. SLIGHTLY BELOW NORMAL TEMPS ARE EXPECTED DURING THE WEEKEND AND THEN WL SLOWLY TRANSITION TO MORE NORMAL MID SEPTEMBER VALUES THROUGH NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 78 89 74 88 71 / 40 60 60 40 20 VICTORIA 74 86 71 87 64 / 40 60 40 20 10 LAREDO 78 93 73 90 71 / 40 60 60 30 20 ALICE 75 90 72 88 68 / 40 60 60 40 20 ROCKPORT 79 87 75 87 72 / 40 60 60 40 20 COTULLA 76 90 73 91 67 / 40 60 40 20 10 KINGSVILLE 77 91 73 88 70 / 40 60 60 40 20 NAVY CORPUS 79 87 76 87 74 / 40 60 60 40 20 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ WC/87...AVIATION
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
647 PM CDT THU SEP 10 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...MOISTURE WILL CONTINUE TO POOL ACROSS SOUTHERN TEXAS WELL SOUTH OF A COLD FRONT LOCATED IN CENTRAL TEXAS. SCATTERED SHOWERS AND STORMS HAVE BEEN ONGOING THIS AFTERNOON MAINLY NORTH OF THE VALLEY AND HAVE BEEN SHOWING A DECREASING TREND OVER THE PAST HOUR AND THIS IS ECHOED IN THE MOST RECENT HRRR MODEL. OVERNIGHT TONIGHT WILL SEE A MIX OF MAINLY HIGH CLOUDS FROM CONVECTION TO THE NORTH AND FEW-SCT LOW CLOUDS DEVELOPING IN MOIST CONDS ACROSS DEEP SOUTH TEXAS. WINDS WILL LAY DOWN AROUND MID EVENING AND REMAIN BELOW 10 KTS THROUGH AROUND MID MORNING. CUMULUS WILL DEVELOP 14-15Z AROUND 2500 FEET AND WINDS WILL BEGIN TO PICK UP AT THIS TIME WITH GUSTS 18-22 KNOTS THROUGH THE AFTERNOON HOURS. RAIN CHANCES INCREASE LATE MORNING AND AFTERNOON WITH MAINLY ISOLD TO SCT SEABREEZE CONVECTION AFFECTING THE TAF SITES WITH MORE ORGANIZED CONVECTION AFFECTING WEST OF RGC-HBV LATE AFTERNOON. WILL INSERT VCTS TO THE TAF SITES BEGINNING LATE MORNING FRIDAY. TEMPO MVFR CONDS CAN BE EXPECTED UNDER ANY STORM FRIDAY. && .PREV DISCUSSION... /ISSUED 230 PM CDT THU SEP 10 2015/ SHORT TERM /NOW THROUGH FRIDAY NIGHT/...MORE ACTIVE WEATHER PATTERN SETTING UP FOR THE SHORT TERM AS THE FIRST AUTUMN COLD FRONT MOVES THROUGH TEXAS. DEEP TROPICAL MOISTURE IS SETTLING INTO THE REGION ALREADY...WITH PW VALUES ALREADY ABOVE 2 INCHES. MOISTURE COMPRESSING AHEAD OF THE FRONT AND SMALLER BOUNDARIES HAVE ALREADY SPARKED A FEW SHOWERS ALONG THE SEABREEZE TODAY...BUT INSTABILITY ALOFT HAS STAYED WELL OFFSHORE STILL. TOMORROW WITH THE FRONT IN THE VICINITY...RAIN CHANCES ARE LIKELY AREAWIDE... STARTING TO THE NORTH AND MOVING SOUTHWARD ALONG AND AHEAD OF THE FRONT. WITH PW VALUES FORECAST ABOVE 2.2 INCHES...ANY RAINFALL WILL LIKELY BE VERY HEAVY IN SOME LOCATIONS. SINCE STORMS ARE FIRING WITH A MOVING BOUNDARY...CELLS WONT BE IDLING ON ONE LOCATION FOR A LONG PERIOD OF TIME. THE MAIN FOCUS TIME FOR THE RAINFALL WILL BE LATE TOMORROW AFTERNOON THROUGH SUNRISE SATURDAY. RAINFALL AMOUNTS ABOVE 3 INCHES ARE POSSIBLE...ESPECIALLY ACROSS THE WESTERN VALLEY. CLOUD COVER WILL ALSO BE HIGHER TOMORROW... SO HIGH TEMPERATURES WILL STRUGGLE TO REACH 90 DEGREES... ESPECIALLY FOR THE NORTHERN RANCHLANDS. LONG TERM /SATURDAY THROUGH WEDNESDAY/...THE BEST LIFT SHOULD BE FRIDAY AND FRIDAY NIGHT...WITH HIGH PRESSURE AND DRIER AIR CONTINUING TO FILTER INTO THE AREA ON SATURDAY CAN NOT RULE OUT SOME LINGERING MODERATE RAIN POTENTIAL EARLY SATURDAY...BUT THE MODELS SEEM TO AGREE WITH PUSHING MOST OF THE ENERGY SOUTH OF THE RIVER BY LATE IN THE DAY. THE CANADIAN DIFFERS SLIGHTLY WITH HIGHER QPF ALONG THE COAST SATURDAY MORNING...AS OPPOSED TO OVER THE MID AND UPPER VALLEY PER THE GFS/ECMWF. TIME HEIGHT SHOWS DRIER MIDLEVEL AIR MOVING IN SATURDAY AS DEEPER NORTHEAST WINDS SET UP. THUS...LIGHTER RAINS...WITH A FEW HEAVIER SHOWERS AND AN EMBEDDED THUNDERSTORM EARLY...WILL BE THE RULE SATURDAY. TROPICAL...BOTH THE GFS AND ECMWF MAINTAIN LOW PRESSURE IN THE SOUTHWEST GULF THROUGH THE WEEKEND...DRIFTING A WEAK CIRCULATION NORTH ALONG THE MEXICAN COAST TOWARD BROWNSVILLE BY TUESDAY...WHERE IT WILL REMAIN IDENTIFIABLE AS A FEATURE. MARINE... NOW THROUGH FRIDAY NIGHT...MAIN MARINE THREAT IS CONTINUED THUNDERSTORM ACTIVITY THROUGH THE SHORT TERM. MARINE INSTABILITY WILL BRING INCREASED COVERAGE OVERNIGHT TONIGHT...ESPECIALLY FURTHER OFFSHORE NEARER THE MIDLEVEL TROUGH. SEAS WILL REMAIN 2 TO 3 FEET...EXCEPT FOR HIGHER AGITATION NEAR STORMS. THE COLD FRONT ARRIVES LATE TOMORROW...WITH A MODEST WIND SHIFT TO THE NORTHEAST. SINCE THE FRONT IS ALREADY SLOWING DOWN WHEN IT ARRIVES...NORTHEAST FLOW WILL REMAIN 15KTS OR LESS BEHIND THE WIND SHIFT. THIS WILL KEEP THE SEAS FROM BUILDING SIGNIFICANTLY BEHIND THE FRONT...STAYING ABOUT 3 FEET. SATURDAY THROUGH MONDAY...LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS WILL PREVAIL ALONG THE LWR TEXAS COAST INITIALLY... BUT A SURGE OF HIGH PRESSURE WILL PRODUCE A MODERATE NORTHEAST WIND...HELPING TO BUMP SEAS UP A COUPLE OF FEET SUNDAY THROUGH MONDAY AS A WEAK COLD FRONT PASSES THROUGH. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 55
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1226 PM CDT WED SEP 9 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...VFR CONDITIONS. SEA BREEZE NOT QUITE ESTABLISHED YET...AND MAY HAVE A TOUGH TIME WITH BREEZY SOUTH SOUTHEAST WINDS IN CONTROL. FEW TO SCT LOW CLOUDS MAINLY EAST OF US281/IH69C. MOSTLY CLEAR SKIES TONIGHT. DEEPER MOISTURE WILL BRING THICKER CLOUDS ON THURSDAY...BUT STILL LOOKING FOR VFR CONDITIONS. A WEAK SEA BREEZE WILL BE POSSIBLE. && .PREV DISCUSSION... /ISSUED 652 AM CDT WED SEP 9 2015/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...LIGHT SOUTHEAST WINDS WITH A FEW PASSING CLOUDS PREVAIL OVER DEEP SOUTH TEXAS THIS MORNING. VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS...EXCEPT A BRIEF PERIOD OF MVFR CONDITIONS POSSIBLE IN ANY CONVECTION. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE EASTERN PORTIONS OF THE CWA ALONG AND AHEAD OF THE SEABREEZE FRONT MOVING INLAND THIS AFTERNOON. LIGHT SOUTHEAST WINDS WILL BECOME MODERATE LATER THIS MORNING WITH GUSTS AROUND 20 KNOTS IN THE AFTERNOON. WINDS WILL GRADUALLY WEAKEN THIS EVENING AND OVERNIGHT. PREV DISCUSSION... /ISSUED 434 AM CDT WED SEP 9 2015/ SHORT TERM /NOW THROUGH THURSDAY/...LATEST WATER VAPOR SATELLITE IMAGERY SHOWS A 500MB RIDGE CENTERED OVER WEST TEXAS INTO NORTHERN MEXICO AND A 500MB LOW OVER THE WESTERN GULF OF MEXICO. BROWNSVILLE RADAR SHOWS VERY ISOLATED ACTIVITY ACROSS THE LOWER TEXAS GULF WATERS THIS MORNING. THE LATEST HRRR SUGGESTS CONVECTION WILL INCREASE ACROSS THE GULF WATERS LATER THIS MORNING. BRO SOUNDING FROM TUESDAY EVENING INDICATES PRECIPITABLE WATER VALUES OF 2.02 INCHES. MOSTLY CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS DEEP SOUTH TEXAS EARLY THIS MORNING. NOTE...THE SURFACE OBSERVATION FROM EDINBURG IS NOT REPRESENTATIVE TO CURRENT WEATHER CONDITIONS. THE COMBINATION OF THE 500MB LOW ACROSS THE WESTERN GULF OF MEXICO AND A FRONT MOVING SOUTH OVER CENTRAL TEXAS WILL ALLOW LOW TO MID LEVEL MOISTURE TO INCREASE ACROSS DEEP SOUTH TEXAS THROUGH THE FORECAST PERIOD. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE EASTERN PORTIONS OF THE CWA ALONG AND AHEAD OF THE SEABREEZE FRONT MOVING INLAND THIS AFTERNOON. THE LATEST HRRR/GFS AND ECMWF SUGGEST AN ACTIVE SEA BREEZE TODAY WHILE THE MET REMAINS GENERALLY DRY. WILL LEAN TOWARDS THE WETTER MAV/ECMWF MOS POPS FOR TODAY. DEEPER MOISTURE SHOULD SUPPORT MORE ACTIVITY ACROSS THE AREA ON THURSDAY...ESPECIALLY ACROSS THE COASTAL WATERS AND THE RANCHLANDS. WILL BLEND TOWARDS THE WETTER NAM/ECMWF FOR POPS AREA WIDE FOR THURSDAY. ANY OF THE HEAVIER OR SLOWER-MOVING SHOWERS AND THUNDERSTORMS TODAY AND THURSDAY WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL WITH NUISANCE FLOODING ON ROADS AND IN LOW-LYING AREAS...ESPECIALLY THOSE WITH A HISTORY OF FLOODING. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 90S NEAR THE COAST TO AROUND 100 ACROSS THE UPPER VALLEY. HIGH TEMPERATURES WILL BE A FEW DEGREES LOWER ON THURSDAY DUE TO THE INCREASE IN CLOUDS AND RAIN CHANCES. LOW TEMPERATURES TONIGHT WILL GENERALLY BE IN THE UPPER 70S TO AROUND 80. LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...RATHER BUSY LONG TERM PORTION OF THE FORECAST ANTICIPATED. DEEP TROPICAL MOISTURE (PRECIPITABLE WATER VALUES IN EXCESS OF 2 INCHES) WILL COMBINE WITH THE FRIDAY NIGHT PASSAGE OF A WEAK COLD FRONT...AND THE SUBSEQUENT DEVELOPMENT AND PERSISTENCE OF AN INVERTED SURFACE TROUGH OF LOW PRESSURE ALONG THE LOWER TEXAS COAST AFTERWARDS. WITH PERSISTENT 500 MB TROUGHINESS ALONG THE TEXAS COASTLINE IN ASSOCIATION WITH A CLOSED 500 MB LOW PRESSURE SYSTEM OVER THE GREAT LAKES REGION...DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY CAN EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS FOR MUCH OF THE FORECAST PERIOD...WITH THE HIGHEST RAIN CHANCES FROM FRIDAY THROUGH SATURDAY...WHEN LOCALLY HEAVY RAINFALL HAS ALSO BEEN INCLUDED IN THE FORECAST. THE MOST INTERESTING ASPECT OF THE LONG TERM FORECAST PERIOD IS THE GFS` INDICATION THAT A WEAK CLOSED AREA OF LOW PRESSURE WILL FORM OVER THE WESTERN GULF OF MEXICO AND MOVE INLAND OVER THE BRO CWFA TOWARDS THE END OF THE FORECAST PERIOD. ANY CLOSED AREA OF LOW PRESSURE...SHOULD IT FORM...WOULD HAVE THE ABILITY TO RADICALLY CHANGE PRECIPITATION AND WIND VALUES ON MONDAY AND TUESDAY...AND THIS WILL NEED TO BE MONITORED BY SUCCESSIVE SHIFTS THROUGH THE NEXT FEW DAYS. MARINE...NOW THROUGH THURSDAY...BUOY DATA AND OBSERVATION PLATFORMS ALONG THE LOWER TEXAS COAST THIS MORNING INDICATE SOUTH WINDS BETWEEN 8 TO 13 KNOTS WITH SEA HEIGHTS NEAR 3 FEET ON THE GULF WATERS. A WEAK PRESSURE GRADIENT OVER THE WESTERN GULF OF MEXICO WILL MAINTAIN LIGHT TO MODERATE SOUTHEAST TO SOUTH WINDS AND LOW TO MODERATE SEAS. HOWEVER...SMALL CRAFT WILL NEED TO EXERCISE CAUTION ON THE LAGUNA MADRE THIS AFTERNOON DUE TO A SLIGHTLY STRONGER WINDS. THURSDAY NIGHT THROUGH TUESDAY...GENERALLY LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS ARE EXPECTED THROUGH THE PERIOD AS WEAK LOW PRESSURE PERSISTS OVER THE WESTERN GULF OF MEXICO AND A COLD FRONT INTRUDES INTO THE LOWER TEXAS COASTAL WATERS. WEAK CLOSED LOW PRESSURE MAY DEVELOP ALONG THE LOWER TEXAS COAST TOWARDS THE END OF THE FORECAST PERIOD PER ONE WEATHER FORECAST MODEL...BUT THE STRONGER WINDS AND HIGHER SEAS INDICATED IN ASSOCIATION WITH THE LOW PRESSURE DEVELOPMENT HAVE NOT BEEN INCLUDED IN THE FORECAST AT THIS TIME. BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 54/64
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1029 AM CDT WED SEP 9 2015 .UPDATE... MORNING FORECAST UPDATE... && .DISCUSSION... LATEST RADAR TRENDS SHOW SHOWER ACTIVITY LEFT OVER FROM A MORNING MCS OVER N TX. MCS HAS FOR THE MOST PART JUST FALLEN APART WITH OUTFLOW PUSHING SOUTH IN THE AREA. MAIN QUESTION WILL BE HOW MUCH RE-DEVELOPMENT OF CONVECTION OCCURS ALONG THE OUTFLOW. UPPER LEVEL ANALYSIS HAS UPPER RIDGE OVER THE S ROCKIES WITH NW/N FLOW ALOFT OVER SE TX THAT WRAPS AROUND AN UPPER LOW OVER THE N GULF. LOWER 500MB HEIGHTS AND PRECIP WATER VALUES AROUND 1.8-2 INCHES SUGGEST ISO TO SCT SHRA/TSRA ACTIVITY AS TEMPS WARM TOWARDS 90F MARK. RADAR ALREADY SHOWS SCT ACTIVITY OFF THE COAST AND JUST INLAND. UPDATED RAIN CHANCES TO PRETTY MUCH 40 PRECENT AREAWIDE TO ACCOUNT FOR SCT SHRA/TSRA ACTIVITY. THERE EVEN MAY BE AN ISO STRONG STORM SINCE CRP/LCH SOUNDINGS SHOW AROUND 2000 J/KG OF CAPE THIS MORNING. THINK THE MAIN THREATS WILL BE BRIEF HEAVY RAINFALL AND GUSTY WINDS WITH FREEZING LEVELS QUITE HIGH. CLOUD COVER MAY KEEP TEMPS IN THE 80S BUT THERE COULD BE ENOUGH BREAKS TO REACH LOW 90S. MAIN CHANGES TO THE FORECAST WERE TO UPDATE POP/WX/T/TD FORECAST BASED ON CURRENT TRENDS. 39 && .PREV DISCUSSION... /ISSUED / DISCUSSION... SEE 12Z AVIATION DISCUSSION. AVIATION... PRECIP OVER N TX CONTINUES TO SAG SOUTH AND IF THE LINE HOLDS TOGETHER...IT SHOULD ARRIVE AT NORTHERN TAF SITES AROUND 15Z. SHORT TERM GUIDANCE SUGGESTS THAT THE AREA WILL WEAKEN AND IR IMAGERY SHOWS SOME SLIGHT WARMING OF THE CLOUD TOPS. KGRK VWP STILL SHOWING 30 KTS OF INFLOW INTO THE LINE WHICH SHOULD HELP SUSTAIN THE LINE. PW VALUES WILL EXCEED 2.00 INCHES OVER MUCH OF THEN AREA TODAY SO SCT SHRA/ISO TSRA WILL BE POSSIBLE AT ALL TAF SITES TODAY. TIMING IS THE TRICKY PART. TOOK A BLEND OF THE NAM... GFS AND THE ECMWF WITH BEST RAIN CHANCES AT THE HOUSTON TERMINALS BETWEEN 18-03Z. NCEP 4 KM WRF IS VERY AGGRESSIVE WITH PRECIP BETWEEN 09-12Z THURSDAY OVER THE SOUTHERN TAF SITES. NOT SURE IF IT IS ON TO SOMETHING BUT ADDED VCSH FOR KSGR...KHOU...KLBX AND KGLS FOR EARLY THURSDAY MORNING. 43 PREV DISCUSSION... /ISSUED / DISCUSSION... REGIONAL RADAR MOSAIC EARLY THIS MORNING SHOWED A COMPLEX OF THUNDERSTORMS LOCATED ALONG THE INTERSTATE 20 CORRIDOR PUSHING SOUTH. EARLY MORNING WATER VAPOR IMAGERY SHOWED THIS COMPLEX WAS AIDED BY A SHORTWAVE TROUGH MOVING ACROSS NORTH TEXAS... WITH 06Z SURFACE ANALYSIS PLACING A COLD FRONT BEHIND THESE THUNDERSTORMS FROM WEST TEXAS INTO CENTRAL OKLAHOMA. EVENING UPPER AIR ANALYSIS SHOWED A BROAD UPPER TROUGH SWINGING ACROSS THE SOUTHERN/CENTRAL PLAINS AND THIS TROUGH WILL HELP PUSH THE COLD FRONT CLOSER TO THE REGION THROUGHOUT TODAY AND TOMORROW. FOR TODAY... THE FT. HOOD VAD WIND PROFILER SHOWS 25 TO 30 KNOTS OF SOUTHERLY INFLOW FEEDING INTO THE THUNDERSTORM COMPLEX OVER NORTH TEXAS EARLY THIS MORNING. THIS SHOULD HELP THESE THUNDERSTORMS MAINTAIN THEMSELVES THROUGH THE REMAINDER OF THE EARLY MORNING HOURS. AS LOW LEVEL INFLOW VEERS AND WEAKENS LATER LATER THIS MORNING HOWEVER... UNCERTAINTY BEGINS TO INCREASE ON HOW FAR SOUTH THIS COMPLEX WILL MAKE IT. SOME HIGH RESOLUTION GUIDANCE SOLUTIONS /NOTABLY THE HRRR AND TEXAS TECH WRF/ SHOWS OUTFLOW FROM THIS COMPLEX REACHING THE BRAZOS VALLEY LATE MORNING/EARLY AFTERNOON. GIVEN RADAR AND SATELLITE TRENDS... THINK AREAS NORTH OF A BRENHAM TO LIVINGSTON LINE APPEAR TO BE THE MOST LIKELY TO SEE RAIN FROM THIS COMPLEX OR ANY ASSOCIATED OUTFLOW AND HIGHLIGHTING THE HIGHEST POPS FOR THE DAY IN THESE AREAS. EVEN IF THE STORMS DISSIPATE BEFORE THE OUTFLOW REACHES THE AREA... DIABATIC HEATING MAY CONTRIBUTE TO ADDITIONAL DEVELOPMENT ALONG IT LATER THIS AFTERNOON. FARTHER SOUTH... CONVECTIVE TEMPERATURES NEAR 90 TODAY WILL ALSO SUPPORT ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT ACROSS THE REMAINDER OF THE REGION... ESPECIALLY AS A SEA BREEZE MOVES FARTHER INLAND. THE UPPER LOW CHURNING OVER THE NORTHERN GULF EARLY THIS MORNING IS EXPECTED TO SHEAR OUT TODAY... DECREASING THE SUBSIDENCE THAT HAS LIMITED MORE ROBUST COVERAGE OVER THE PAST FEW DAYS. IF THE OUTFLOW IS ABLE TO MAKE IT FARTHER SOUTH TODAY THAN ORIGINALLY THOUGHT... POPS ALSO WILL NEED TO BE INCREASED FARTHER SOUTH TODAY. ADDITIONALLY... FORECAST SOUNDINGS FOR HOUSTON THIS AFTERNOON HAVE A DISTINCT INVERTED-V SIGNATURE AND THIS WILL SUPPORT AT LEAST AN ISOLATED GUSTY WIND THREAT FROM ANY THUNDERSTORM THAT DEVELOPS. THE COLD FRONT IS EXPECTED TO MAKE SLOW PROGRESS ACROSS NORTH TEXAS TODAY... AND WITH SOME UNCERTAINTY ON WHERE OUTFLOW FROM TODAY/S THUNDERSTORMS WILL END UP KEEPING POPS HIGHEST TONIGHT ALONG AND NORTH OF A BRENHAM TO CLEVELAND LINE. AS PRECIPITABLE WATER VALUES RISE TO NEAR 2 INCHES LATER TODAY AND INTO TOMORROW... LOCALLY HEAVY RAIN WILL REMAIN POSSIBLE. OTHERWISE... EXPECT HIGHS IN THE UPPER 80S TO LOW 90S TODAY AND LOWS IN THE 70S TO NEAR 80 TONIGHT. THE GREAT PLAINS UPPER TROUGH WILL CONTINUE TO SWING EAST TOWARDS THE GREAT LAKES ON THURSDAY... WITH ITS AXIS EXTENDING OVER THE REGION. THE COLD FRONT WILL MAKE MORE PROGRESS INTO/ STALL SOMEWHERE ACROSS CENTRAL TEXAS ON THURSDAY AND THIS WITH ADDED LIFT FROM A 50-60 KNOT UPPER LEVEL JET STREAK APPROACHING FROM WEST TEXAS WILL KEEP SCATTERED TO NUMEROUS THUNDERSTORMS IN THE FORECAST ON THURSDAY AND FRIDAY. HIGHS TO END THE WEEK WILL BE NEAR NORMAL IN THE MID TO UPPER 80S. HEADING INTO THE WEEKEND... A STRONG SHORTWAVE TROUGH ROTATING AROUND THE BASE OF THE BROAD UPPER TROUGH FRIDAY/SATURDAY WILL SEND A SECONDARY... STRONGER FRONT INTO THE REGION. THIS FRONT LOOKS TO PUSH THROUGH THE REGION SOMETIME ON SATURDAY WITH MUCH DRIER AIR FILTERING INTO THE AREA BEHIND IT. PRECIPITABLE WATER VALUES WILL FALL THROUGHOUT THE DAY ON SATURDAY... BOTTOMING OUT UNDER ONE INCH ON SUNDAY. THIS WILL ALLOW RAIN CHANCES TO TAPER OFF FROM NORTH TO SOUTH DURING THE DAY ON SATURDAY AND PROVIDE WHAT APPEARS TO BE A VERY PLEASANT SUNDAY IN THE MAKING. DRIER AIR WILL ALLOW FOR OVERNIGHT LOW TEMPERATURES TO POSSIBLY FALL INTO THE 60S SUNDAY... WITH HIGHS IN THE LOW TO MID 80S. MEDIUM RANGE GUIDANCE CONTINUES TO SHOW THE DEVELOPMENT OF A COASTAL TROUGH/SURFACE LOW OFF MEXICO/DEEP SOUTH TEXAS HEADING INTO THE BEGINNING OF NEXT WEEK. WHILE STILL OFFERING SOMEWHAT DIFFERENT SOLUTIONS... THE GFS AND THE EUROPEAN BOTH ADVERTISE A GOOD SLUG OF TROPICAL MOISTURE ASSOCIATED WITH THIS FEATURE MAKING ITS WAY BACK INTO THE REGION /GFS PWATS INCREASE FROM LESS THAN ONE INCH MONDAY TO NEARLY 2 INCHES ON TUESDAY/ HEADING INTO THE MIDDLE OF NEXT WEEK. SHOWER AND THUNDERSTORM CHANCES WILL RETURN AS THIS SYSTEM EJECTS NORTHWARD TOWARDS THE TEXAS COAST... AND WILL NEED TO CONTINUE TO MONITOR FOR THE POTENTIAL OF HEAVY RAIN. HUFFMAN MARINE... LIGHT TO MODERATE ONSHORE FLOW WILL PERSIST THROUGH FRIDAY. PERIODS OF UNSETTLED WEATHER CAN BE EXPECTED...ESPECIALLY THURSDAY THROUGH SATURDAY...AS UPPER LEVEL DISTURBANCES INTERACT WITH DEEPER MOISTURE IN THE AREA. WINDS/SEAS WILL BE HIGHER IN AND NEAR STORMS. A WEAK FRONTAL BOUNDARY WILL PUSH INTO THE WATERS LATE FRIDAY NIGHT OR SATURDAY MORNING WITH NORTHEAST WINDS IN ITS WAKE. A WEAK TROUGH OF LOW PRESSURE WILL DEVELOP NEAR THE LOWER TEXAS COAST EARLY NEXT WEEK AND THIS FEATURE WILL BRING PERIODS OF SHRA/TSRA AND A PROLONGED PERIOD OF E-SE WINDS TO THE UPPER TEXAS COASTAL WATERS. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 91 75 89 74 89 / 40 50 60 30 40 HOUSTON (IAH) 91 75 89 74 87 / 40 30 60 40 50 GALVESTON (GLS) 88 81 89 79 85 / 40 30 60 50 60 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
652 AM CDT WED SEP 9 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...LIGHT SOUTHEAST WINDS WITH A FEW PASSING CLOUDS PREVAIL OVER DEEP SOUTH TEXAS THIS MORNING. VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS...EXCEPT A BRIEF PERIOD OF MVFR CONDITIONS POSSIBLE IN ANY CONVECTION. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE EASTERN PORTIONS OF THE CWA ALONG AND AHEAD OF THE SEABREEZE FRONT MOVING INLAND THIS AFTERNOON. LIGHT SOUTHEAST WINDS WILL BECOME MODERATE LATER THIS MORNING WITH GUSTS AROUND 20 KNOTS IN THE AFTERNOON. WINDS WILL GRADUALLY WEAKEN THIS EVENING AND OVERNIGHT. && .PREV DISCUSSION... /ISSUED 434 AM CDT WED SEP 9 2015/ SHORT TERM /NOW THROUGH THURSDAY/...LATEST WATER VAPOR SATELLITE IMAGERY SHOWS A 500MB RIDGE CENTERED OVER WEST TEXAS INTO NORTHERN MEXICO AND A 500MB LOW OVER THE WESTERN GULF OF MEXICO. BROWNSVILLE RADAR SHOWS VERY ISOLATED ACTIVITY ACROSS THE LOWER TEXAS GULF WATERS THIS MORNING. THE LATEST HRRR SUGGESTS CONVECTION WILL INCREASE ACROSS THE GULF WATERS LATER THIS MORNING. BRO SOUNDING FROM TUESDAY EVENING INDICATES PRECIPITABLE WATER VALUES OF 2.02 INCHES. MOSTLY CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS DEEP SOUTH TEXAS EARLY THIS MORNING. NOTE...THE SURFACE OBSERVATION FROM EDINBURG IS NOT REPRESENTATIVE TO CURRENT WEATHER CONDITIONS. THE COMBINATION OF THE 500MB LOW ACROSS THE WESTERN GULF OF MEXICO AND A FRONT MOVING SOUTH OVER CENTRAL TEXAS WILL ALLOW LOW TO MID LEVEL MOISTURE TO INCREASE ACROSS DEEP SOUTH TEXAS THROUGH THE FORECAST PERIOD. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE EASTERN PORTIONS OF THE CWA ALONG AND AHEAD OF THE SEABREEZE FRONT MOVING INLAND THIS AFTERNOON. THE LATEST HRRR/GFS AND ECMWF SUGGEST AN ACTIVE SEA BREEZE TODAY WHILE THE MET REMAINS GENERALLY DRY. WILL LEAN TOWARDS THE WETTER MAV/ECMWF MOS POPS FOR TODAY. DEEPER MOISTURE SHOULD SUPPORT MORE ACTIVITY ACROSS THE AREA ON THURSDAY...ESPECIALLY ACROSS THE COASTAL WATERS AND THE RANCHLANDS. WILL BLEND TOWARDS THE WETTER NAM/ECMWF FOR POPS AREA WIDE FOR THURSDAY. ANY OF THE HEAVIER OR SLOWER-MOVING SHOWERS AND THUNDERSTORMS TODAY AND THURSDAY WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL WITH NUISANCE FLOODING ON ROADS AND IN LOW-LYING AREAS...ESPECIALLY THOSE WITH A HISTORY OF FLOODING. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 90S NEAR THE COAST TO AROUND 100 ACROSS THE UPPER VALLEY. HIGH TEMPERATURES WILL BE A FEW DEGREES LOWER ON THURSDAY DUE TO THE INCREASE IN CLOUDS AND RAIN CHANCES. LOW TEMPERATURES TONIGHT WILL GENERALLY BE IN THE UPPER 70S TO AROUND 80. LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...RATHER BUSY LONG TERM PORTION OF THE FORECAST ANTICIPATED. DEEP TROPICAL MOISTURE (PRECIPITABLE WATER VALUES IN EXCESS OF 2 INCHES) WILL COMBINE WITH THE FRIDAY NIGHT PASSAGE OF A WEAK COLD FRONT...AND THE SUBSEQUENT DEVELOPMENT AND PERSISTENCE OF AN INVERTED SURFACE TROUGH OF LOW PRESSURE ALONG THE LOWER TEXAS COAST AFTERWARDS. WITH PERSISTENT 500 MB TROUGHINESS ALONG THE TEXAS COASTLINE IN ASSOCIATION WITH A CLOSED 500 MB LOW PRESSURE SYSTEM OVER THE GREAT LAKES REGION...DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY CAN EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS FOR MUCH OF THE FORECAST PERIOD...WITH THE HIGHEST RAIN CHANCES FROM FRIDAY THROUGH SATURDAY...WHEN LOCALLY HEAVY RAINFALL HAS ALSO BEEN INCLUDED IN THE FORECAST. THE MOST INTERESTING ASPECT OF THE LONG TERM FORECAST PERIOD IS THE GFS` INDICATION THAT A WEAK CLOSED AREA OF LOW PRESSURE WILL FORM OVER THE WESTERN GULF OF MEXICO AND MOVE INLAND OVER THE BRO CWFA TOWARDS THE END OF THE FORECAST PERIOD. ANY CLOSED AREA OF LOW PRESSURE...SHOULD IT FORM...WOULD HAVE THE ABILITY TO RADICALLY CHANGE PRECIPITATION AND WIND VALUES ON MONDAY AND TUESDAY...AND THIS WILL NEED TO BE MONITORED BY SUCCESSIVE SHIFTS THROUGH THE NEXT FEW DAYS. MARINE...NOW THROUGH THURSDAY...BUOY DATA AND OBSERVATION PLATFORMS ALONG THE LOWER TEXAS COAST THIS MORNING INDICATE SOUTH WINDS BETWEEN 8 TO 13 KNOTS WITH SEA HEIGHTS NEAR 3 FEET ON THE GULF WATERS. A WEAK PRESSURE GRADIENT OVER THE WESTERN GULF OF MEXICO WILL MAINTAIN LIGHT TO MODERATE SOUTHEAST TO SOUTH WINDS AND LOW TO MODERATE SEAS. HOWEVER...SMALL CRAFT WILL NEED TO EXERCISE CAUTION ON THE LAGUNA MADRE THIS AFTERNOON DUE TO A SLIGHTLY STRONGER WINDS. THURSDAY NIGHT THROUGH TUESDAY...GENERALLY LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS ARE EXPECTED THROUGH THE PERIOD AS WEAK LOW PRESSURE PERSISTS OVER THE WESTERN GULF OF MEXICO AND A COLD FRONT INTRUDES INTO THE LOWER TEXAS COASTAL WATERS. WEAK CLOSED LOW PRESSURE MAY DEVELOP ALONG THE LOWER TEXAS COAST TOWARDS THE END OF THE FORECAST PERIOD PER ONE WEATHER FORECAST MODEL...BUT THE STRONGER WINDS AND HIGHER SEAS INDICATED IN ASSOCIATION WITH THE LOW PRESSURE DEVELOPMENT HAVE NOT BEEN INCLUDED IN THE FORECAST AT THIS TIME. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 63
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
624 AM CDT WED SEP 9 2015 .DISCUSSION... SEE 12Z AVIATION DISCUSSION. && .AVIATION... PRECIP OVER N TX CONTINUES TO SAG SOUTH AND IF THE LINE HOLDS TOGETHER...IT SHOULD ARRIVE AT NORTHERN TAF SITES AROUND 15Z. SHORT TERM GUIDANCE SUGGESTS THAT THE AREA WILL WEAKEN AND IR IMAGERY SHOWS SOME SLIGHT WARMING OF THE CLOUD TOPS. KGRK VWP STILL SHOWING 30 KTS OF INFLOW INTO THE LINE WHICH SHOULD HELP SUSTAIN THE LINE. PW VALUES WILL EXCEED 2.00 INCHES OVER MUCH OF THEN AREA TODAY SO SCT SHRA/ISO TSRA WILL BE POSSIBLE AT ALL TAF SITES TODAY. TIMING IS THE TRICKY PART. TOOK A BLEND OF THE NAM... GFS AND THE ECMWF WITH BEST RAIN CHANCES AT THE HOUSTON TERMINALS BETWEEN 18-03Z. NCEP 4 KM WRF IS VERY AGGRESSIVE WITH PRECIP BETWEEN 09-12Z THURSDAY OVER THE SOUTHERN TAF SITES. NOT SURE IF IT IS ON TO SOMETHING BUT ADDED VCSH FOR KSGR...KHOU...KLBX AND KGLS FOR EARLY THURSDAY MORNING. 43 && .PREV DISCUSSION... /ISSUED / DISCUSSION... REGIONAL RADAR MOSAIC EARLY THIS MORNING SHOWED A COMPLEX OF THUNDERSTORMS LOCATED ALONG THE INTERSTATE 20 CORRIDOR PUSHING SOUTH. EARLY MORNING WATER VAPOR IMAGERY SHOWED THIS COMPLEX WAS AIDED BY A SHORTWAVE TROUGH MOVING ACROSS NORTH TEXAS... WITH 06Z SURFACE ANALYSIS PLACING A COLD FRONT BEHIND THESE THUNDERSTORMS FROM WEST TEXAS INTO CENTRAL OKLAHOMA. EVENING UPPER AIR ANALYSIS SHOWED A BROAD UPPER TROUGH SWINGING ACROSS THE SOUTHERN/CENTRAL PLAINS AND THIS TROUGH WILL HELP PUSH THE COLD FRONT CLOSER TO THE REGION THROUGHOUT TODAY AND TOMORROW. FOR TODAY... THE FT. HOOD VAD WIND PROFILER SHOWS 25 TO 30 KNOTS OF SOUTHERLY INFLOW FEEDING INTO THE THUNDERSTORM COMPLEX OVER NORTH TEXAS EARLY THIS MORNING. THIS SHOULD HELP THESE THUNDERSTORMS MAINTAIN THEMSELVES THROUGH THE REMAINDER OF THE EARLY MORNING HOURS. AS LOW LEVEL INFLOW VEERS AND WEAKENS LATER LATER THIS MORNING HOWEVER... UNCERTAINTY BEGINS TO INCREASE ON HOW FAR SOUTH THIS COMPLEX WILL MAKE IT. SOME HIGH RESOLUTION GUIDANCE SOLUTIONS /NOTABLY THE HRRR AND TEXAS TECH WRF/ SHOWS OUTFLOW FROM THIS COMPLEX REACHING THE BRAZOS VALLEY LATE MORNING/EARLY AFTERNOON. GIVEN RADAR AND SATELLITE TRENDS... THINK AREAS NORTH OF A BRENHAM TO LIVINGSTON LINE APPEAR TO BE THE MOST LIKELY TO SEE RAIN FROM THIS COMPLEX OR ANY ASSOCIATED OUTFLOW AND HIGHLIGHTING THE HIGHEST POPS FOR THE DAY IN THESE AREAS. EVEN IF THE STORMS DISSIPATE BEFORE THE OUTFLOW REACHES THE AREA... DIABATIC HEATING MAY CONTRIBUTE TO ADDITIONAL DEVELOPMENT ALONG IT LATER THIS AFTERNOON. FARTHER SOUTH... CONVECTIVE TEMPERATURES NEAR 90 TODAY WILL ALSO SUPPORT ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT ACROSS THE REMAINDER OF THE REGION... ESPECIALLY AS A SEA BREEZE MOVES FARTHER INLAND. THE UPPER LOW CHURNING OVER THE NORTHERN GULF EARLY THIS MORNING IS EXPECTED TO SHEAR OUT TODAY... DECREASING THE SUBSIDENCE THAT HAS LIMITED MORE ROBUST COVERAGE OVER THE PAST FEW DAYS. IF THE OUTFLOW IS ABLE TO MAKE IT FARTHER SOUTH TODAY THAN ORIGINALLY THOUGHT... POPS ALSO WILL NEED TO BE INCREASED FARTHER SOUTH TODAY. ADDITIONALLY... FORECAST SOUNDINGS FOR HOUSTON THIS AFTERNOON HAVE A DISTINCT INVERTED-V SIGNATURE AND THIS WILL SUPPORT AT LEAST AN ISOLATED GUSTY WIND THREAT FROM ANY THUNDERSTORM THAT DEVELOPS. THE COLD FRONT IS EXPECTED TO MAKE SLOW PROGRESS ACROSS NORTH TEXAS TODAY... AND WITH SOME UNCERTAINTY ON WHERE OUTFLOW FROM TODAY/S THUNDERSTORMS WILL END UP KEEPING POPS HIGHEST TONIGHT ALONG AND NORTH OF A BRENHAM TO CLEVELAND LINE. AS PRECIPITABLE WATER VALUES RISE TO NEAR 2 INCHES LATER TODAY AND INTO TOMORROW... LOCALLY HEAVY RAIN WILL REMAIN POSSIBLE. OTHERWISE... EXPECT HIGHS IN THE UPPER 80S TO LOW 90S TODAY AND LOWS IN THE 70S TO NEAR 80 TONIGHT. THE GREAT PLAINS UPPER TROUGH WILL CONTINUE TO SWING EAST TOWARDS THE GREAT LAKES ON THURSDAY... WITH ITS AXIS EXTENDING OVER THE REGION. THE COLD FRONT WILL MAKE MORE PROGRESS INTO/ STALL SOMEWHERE ACROSS CENTRAL TEXAS ON THURSDAY AND THIS WITH ADDED LIFT FROM A 50-60 KNOT UPPER LEVEL JET STREAK APPROACHING FROM WEST TEXAS WILL KEEP SCATTERED TO NUMEROUS THUNDERSTORMS IN THE FORECAST ON THURSDAY AND FRIDAY. HIGHS TO END THE WEEK WILL BE NEAR NORMAL IN THE MID TO UPPER 80S. HEADING INTO THE WEEKEND... A STRONG SHORTWAVE TROUGH ROTATING AROUND THE BASE OF THE BROAD UPPER TROUGH FRIDAY/SATURDAY WILL SEND A SECONDARY... STRONGER FRONT INTO THE REGION. THIS FRONT LOOKS TO PUSH THROUGH THE REGION SOMETIME ON SATURDAY WITH MUCH DRIER AIR FILTERING INTO THE AREA BEHIND IT. PRECIPITABLE WATER VALUES WILL FALL THROUGHOUT THE DAY ON SATURDAY... BOTTOMING OUT UNDER ONE INCH ON SUNDAY. THIS WILL ALLOW RAIN CHANCES TO TAPER OFF FROM NORTH TO SOUTH DURING THE DAY ON SATURDAY AND PROVIDE WHAT APPEARS TO BE A VERY PLEASANT SUNDAY IN THE MAKING. DRIER AIR WILL ALLOW FOR OVERNIGHT LOW TEMPERATURES TO POSSIBLY FALL INTO THE 60S SUNDAY... WITH HIGHS IN THE LOW TO MID 80S. MEDIUM RANGE GUIDANCE CONTINUES TO SHOW THE DEVELOPMENT OF A COASTAL TROUGH/SURFACE LOW OFF MEXICO/DEEP SOUTH TEXAS HEADING INTO THE BEGINNING OF NEXT WEEK. WHILE STILL OFFERING SOMEWHAT DIFFERENT SOLUTIONS... THE GFS AND THE EUROPEAN BOTH ADVERTISE A GOOD SLUG OF TROPICAL MOISTURE ASSOCIATED WITH THIS FEATURE MAKING ITS WAY BACK INTO THE REGION /GFS PWATS INCREASE FROM LESS THAN ONE INCH MONDAY TO NEARLY 2 INCHES ON TUESDAY/ HEADING INTO THE MIDDLE OF NEXT WEEK. SHOWER AND THUNDERSTORM CHANCES WILL RETURN AS THIS SYSTEM EJECTS NORTHWARD TOWARDS THE TEXAS COAST... AND WILL NEED TO CONTINUE TO MONITOR FOR THE POTENTIAL OF HEAVY RAIN. HUFFMAN MARINE... LIGHT TO MODERATE ONSHORE FLOW WILL PERSIST THROUGH FRIDAY. PERIODS OF UNSETTLED WEATHER CAN BE EXPECTED...ESPECIALLY THURSDAY THROUGH SATURDAY...AS UPPER LEVEL DISTURBANCES INTERACT WITH DEEPER MOISTURE IN THE AREA. WINDS/SEAS WILL BE HIGHER IN AND NEAR STORMS. A WEAK FRONTAL BOUNDARY WILL PUSH INTO THE WATERS LATE FRIDAY NIGHT OR SATURDAY MORNING WITH NORTHEAST WINDS IN ITS WAKE. A WEAK TROUGH OF LOW PRESSURE WILL DEVELOP NEAR THE LOWER TEXAS COAST EARLY NEXT WEEK AND THIS FEATURE WILL BRING PERIODS OF SHRA/TSRA AND A PROLONGED PERIOD OF E-SE WINDS TO THE UPPER TEXAS COASTAL WATERS. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 92 75 89 74 89 / 60 50 60 30 40 HOUSTON (IAH) 91 75 89 74 87 / 40 30 60 40 50 GALVESTON (GLS) 90 81 89 79 85 / 30 30 60 50 60 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...14 AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
458 AM CDT WED SEP 9 2015 .DISCUSSION... REGIONAL RADAR MOSAIC EARLY THIS MORNING SHOWED A COMPLEX OF THUNDERSTORMS LOCATED ALONG THE INTERSTATE 20 CORRIDOR PUSHING SOUTH. EARLY MORNING WATER VAPOR IMAGERY SHOWED THIS COMPLEX WAS AIDED BY A SHORTWAVE TROUGH MOVING ACROSS NORTH TEXAS... WITH 06Z SURFACE ANALYSIS PLACING A COLD FRONT BEHIND THESE THUNDERSTORMS FROM WEST TEXAS INTO CENTRAL OKLAHOMA. EVENING UPPER AIR ANALYSIS SHOWED A BROAD UPPER TROUGH SWINGING ACROSS THE SOUTHERN/CENTRAL PLAINS AND THIS TROUGH WILL HELP PUSH THE COLD FRONT CLOSER TO THE REGION THROUGHOUT TODAY AND TOMORROW. FOR TODAY... THE FT. HOOD VAD WIND PROFILER SHOWS 25 TO 30 KNOTS OF SOUTHERLY INFLOW FEEDING INTO THE THUNDERSTORM COMPLEX OVER NORTH TEXAS EARLY THIS MORNING. THIS SHOULD HELP THESE THUNDERSTORMS MAINTAIN THEMSELVES THROUGH THE REMAINDER OF THE EARLY MORNING HOURS. AS LOW LEVEL INFLOW VEERS AND WEAKENS LATER LATER THIS MORNING HOWEVER... UNCERTAINTY BEGINS TO INCREASE ON HOW FAR SOUTH THIS COMPLEX WILL MAKE IT. SOME HIGH RESOLUTION GUIDANCE SOLUTIONS /NOTABLY THE HRRR AND TEXAS TECH WRF/ SHOWS OUTFLOW FROM THIS COMPLEX REACHING THE BRAZOS VALLEY LATE MORNING/EARLY AFTERNOON. GIVEN RADAR AND SATELLITE TRENDS... THINK AREAS NORTH OF A BRENHAM TO LIVINGSTON LINE APPEAR TO BE THE MOST LIKELY TO SEE RAIN FROM THIS COMPLEX OR ANY ASSOCIATED OUTFLOW AND HIGHLIGHTING THE HIGHEST POPS FOR THE DAY IN THESE AREAS. EVEN IF THE STORMS DISSIPATE BEFORE THE OUTFLOW REACHES THE AREA... DIABATIC HEATING MAY CONTRIBUTE TO ADDITIONAL DEVELOPMENT ALONG IT LATER THIS AFTERNOON. FARTHER SOUTH... CONVECTIVE TEMPERATURES NEAR 90 TODAY WILL ALSO SUPPORT ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT ACROSS THE REMAINDER OF THE REGION... ESPECIALLY AS A SEA BREEZE MOVES FARTHER INLAND. THE UPPER LOW CHURNING OVER THE NORTHERN GULF EARLY THIS MORNING IS EXPECTED TO SHEAR OUT TODAY... DECREASING THE SUBSIDENCE THAT HAS LIMITED MORE ROBUST COVERAGE OVER THE PAST FEW DAYS. IF THE OUTFLOW IS ABLE TO MAKE IT FARTHER SOUTH TODAY THAN ORIGINALLY THOUGHT... POPS ALSO WILL NEED TO BE INCREASED FARTHER SOUTH TODAY. ADDITIONALLY... FORECAST SOUNDINGS FOR HOUSTON THIS AFTERNOON HAVE A DISTINCT INVERTED-V SIGNATURE AND THIS WILL SUPPORT AT LEAST AN ISOLATED GUSTY WIND THREAT FROM ANY THUNDERSTORM THAT DEVELOPS. THE COLD FRONT IS EXPECTED TO MAKE SLOW PROGRESS ACROSS NORTH TEXAS TODAY... AND WITH SOME UNCERTAINTY ON WHERE OUTFLOW FROM TODAY/S THUNDERSTORMS WILL END UP KEEPING POPS HIGHEST TONIGHT ALONG AND NORTH OF A BRENHAM TO CLEVELAND LINE. AS PRECIPITABLE WATER VALUES RISE TO NEAR 2 INCHES LATER TODAY AND INTO TOMORROW... LOCALLY HEAVY RAIN WILL REMAIN POSSIBLE. OTHERWISE... EXPECT HIGHS IN THE UPPER 80S TO LOW 90S TODAY AND LOWS IN THE 70S TO NEAR 80 TONIGHT. THE GREAT PLAINS UPPER TROUGH WILL CONTINUE TO SWING EAST TOWARDS THE GREAT LAKES ON THURSDAY... WITH ITS AXIS EXTENDING OVER THE REGION. THE COLD FRONT WILL MAKE MORE PROGRESS INTO/ STALL SOMEWHERE ACROSS CENTRAL TEXAS ON THURSDAY AND THIS WITH ADDED LIFT FROM A 50-60 KNOT UPPER LEVEL JET STREAK APPROACHING FROM WEST TEXAS WILL KEEP SCATTERED TO NUMEROUS THUNDERSTORMS IN THE FORECAST ON THURSDAY AND FRIDAY. HIGHS TO END THE WEEK WILL BE NEAR NORMAL IN THE MID TO UPPER 80S. HEADING INTO THE WEEKEND... A STRONG SHORTWAVE TROUGH ROTATING AROUND THE BASE OF THE BROAD UPPER TROUGH FRIDAY/SATURDAY WILL SEND A SECONDARY... STRONGER FRONT INTO THE REGION. THIS FRONT LOOKS TO PUSH THROUGH THE REGION SOMETIME ON SATURDAY WITH MUCH DRIER AIR FILTERING INTO THE AREA BEHIND IT. PRECIPITABLE WATER VALUES WILL FALL THROUGHOUT THE DAY ON SATURDAY... BOTTOMING OUT UNDER ONE INCH ON SUNDAY. THIS WILL ALLOW RAIN CHANCES TO TAPER OFF FROM NORTH TO SOUTH DURING THE DAY ON SATURDAY AND PROVIDE WHAT APPEARS TO BE A VERY PLEASANT SUNDAY IN THE MAKING. DRIER AIR WILL ALLOW FOR OVERNIGHT LOW TEMPERATURES TO POSSIBLY FALL INTO THE 60S SUNDAY... WITH HIGHS IN THE LOW TO MID 80S. MEDIUM RANGE GUIDANCE CONTINUES TO SHOW THE DEVELOPMENT OF A COASTAL TROUGH/SURFACE LOW OFF MEXICO/DEEP SOUTH TEXAS HEADING INTO THE BEGINNING OF NEXT WEEK. WHILE STILL OFFERING SOMEWHAT DIFFERENT SOLUTIONS... THE GFS AND THE EUROPEAN BOTH ADVERTISE A GOOD SLUG OF TROPICAL MOISTURE ASSOCIATED WITH THIS FEATURE MAKING ITS WAY BACK INTO THE REGION /GFS PWATS INCREASE FROM LESS THAN ONE INCH MONDAY TO NEARLY 2 INCHES ON TUESDAY/ HEADING INTO THE MIDDLE OF NEXT WEEK. SHOWER AND THUNDERSTORM CHANCES WILL RETURN AS THIS SYSTEM EJECTS NORTHWARD TOWARDS THE TEXAS COAST... AND WILL NEED TO CONTINUE TO MONITOR FOR THE POTENTIAL OF HEAVY RAIN. HUFFMAN && .MARINE... LIGHT TO MODERATE ONSHORE FLOW WILL PERSIST THROUGH FRIDAY. PERIODS OF UNSETTLED WEATHER CAN BE EXPECTED...ESPECIALLY THURSDAY THROUGH SATURDAY...AS UPPER LEVEL DISTURBANCES INTERACT WITH DEEPER MOISTURE IN THE AREA. WINDS/SEAS WILL BE HIGHER IN AND NEAR STORMS. A WEAK FRONTAL BOUNDARY WILL PUSH INTO THE WATERS LATE FRIDAY NIGHT OR SATURDAY MORNING WITH NORTHEAST WINDS IN ITS WAKE. A WEAK TROUGH OF LOW PRESSURE WILL DEVELOP NEAR THE LOWER TEXAS COAST EARLY NEXT WEEK AND THIS FEATURE WILL BRING PERIODS OF SHRA/TSRA AND A PROLONGED PERIOD OF E-SE WINDS TO THE UPPER TEXAS COASTAL WATERS. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 92 75 89 74 89 / 60 50 60 30 40 HOUSTON (IAH) 91 75 89 74 87 / 40 30 60 40 50 GALVESTON (GLS) 90 81 89 79 85 / 30 30 60 50 60 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...14 AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
434 AM CDT WED SEP 9 2015 .SHORT TERM /NOW THROUGH THURSDAY/...LATEST WATER VAPOR SATELLITE IMAGERY SHOWS A 500MB RIDGE CENTERED OVER WEST TEXAS INTO NORTHERN MEXICO AND A 500MB LOW OVER THE WESTERN GULF OF MEXICO. BROWNSVILLE RADAR SHOWS VERY ISOLATED ACTIVITY ACROSS THE LOWER TEXAS GULF WATERS THIS MORNING. THE LATEST HRRR SUGGESTS CONVECTION WILL INCREASE ACROSS THE GULF WATERS LATER THIS MORNING. BRO SOUNDING FROM TUESDAY EVENING INDICATES PRECIPITABLE WATER VALUES OF 2.02 INCHES. MOSTLY CLEAR SKIES AND LIGHT WINDS PREVAIL ACROSS DEEP SOUTH TEXAS EARLY THIS MORNING. NOTE...THE SURFACE OBSERVATION FROM EDINBURG IS NOT REPRESENTATIVE TO CURRENT WEATHER CONDITIONS. THE COMBINATION OF THE 500MB LOW ACROSS THE WESTERN GULF OF MEXICO AND A FRONT MOVING SOUTH OVER CENTRAL TEXAS WILL ALLOW LOW TO MID LEVEL MOISTURE TO INCREASE ACROSS DEEP SOUTH TEXAS THROUGH THE FORECAST PERIOD. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE EASTERN PORTIONS OF THE CWA ALONG AND AHEAD OF THE SEABREEZE FRONT MOVING INLAND THIS AFTERNOON. THE LATEST HRRR/GFS AND ECMWF SUGGEST AN ACTIVE SEA BREEZE TODAY WHILE THE MET REMAINS GENERALLY DRY. WILL LEAN TOWARDS THE WETTER MAV/ECMWF MOS POPS FOR TODAY. DEEPER MOISTURE SHOULD SUPPORT MORE ACTIVITY ACROSS THE AREA ON THURSDAY...ESPECIALLY ACROSS THE COASTAL WATERS AND THE RANCHLANDS. WILL BLEND TOWARDS THE WETTER NAM/ECMWF FOR POPS AREA WIDE FOR THURSDAY. ANY OF THE HEAVIER OR SLOWER-MOVING SHOWERS AND THUNDERSTORMS TODAY AND THURSDAY WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL WITH NUISANCE FLOODING ON ROADS AND IN LOW-LYING AREAS...ESPECIALLY THOSE WITH A HISTORY OF FLOODING. HIGH TEMPERATURES TODAY WILL RANGE FROM THE LOWER 90S NEAR THE COAST TO AROUND 100 ACROSS THE UPPER VALLEY. HIGH TEMPERATURES WILL BE A FEW DEGREES LOWER ON THURSDAY DUE TO THE INCREASE IN CLOUDS AND RAIN CHANCES. LOW TEMPERATURES TONIGHT WILL GENERALLY BE IN THE UPPER 70S TO AROUND 80. .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...RATHER BUSY LONG TERM PORTION OF THE FORECAST ANTICIPATED. DEEP TROPICAL MOISTURE (PRECIPITABLE WATER VALUES IN EXCESS OF 2 INCHES) WILL COMBINE WITH THE FRIDAY NIGHT PASSAGE OF A WEAK COLD FRONT...AND THE SUBSEQUENT DEVELOPMENT AND PERSISTENCE OF AN INVERTED SURFACE TROUGH OF LOW PRESSURE ALONG THE LOWER TEXAS COAST AFTERWARDS. WITH PERSISTENT 500 MB TROUGHINESS ALONG THE TEXAS COASTLINE IN ASSOCIATION WITH A CLOSED 500 MB LOW PRESSURE SYSTEM OVER THE GREAT LAKES REGION...DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY CAN EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS FOR MUCH OF THE FORECAST PERIOD...WITH THE HIGHEST RAIN CHANCES FROM FRIDAY THROUGH SATURDAY...WHEN LOCALLY HEAVY RAINFALL HAS ALSO BEEN INCLUDED IN THE FORECAST. THE MOST INTERESTING ASPECT OF THE LONG TERM FORECAST PERIOD IS THE GFS` INDICATION THAT A WEAK CLOSED AREA OF LOW PRESSURE WILL FORM OVER THE WESTERN GULF OF MEXICO AND MOVE INLAND OVER THE BRO CWFA TOWARDS THE END OF THE FORECAST PERIOD. ANY CLOSED AREA OF LOW PRESSURE...SHOULD IT FORM...WOULD HAVE THE ABILITY TO RADICALLY CHANGE PRECIPITATION AND WIND VALUES ON MONDAY AND TUESDAY...AND THIS WILL NEED TO BE MONITORED BY SUCCESSIVE SHIFTS THROUGH THE NEXT FEW DAYS. && .MARINE...NOW THROUGH THURSDAY...BUOY DATA AND OBSERVATION PLATFORMS ALONG THE LOWER TEXAS COAST THIS MORNING INDICATE SOUTH WINDS BETWEEN 8 TO 13 KNOTS WITH SEA HEIGHTS NEAR 3 FEET ON THE GULF WATERS. A WEAK PRESSURE GRADIENT OVER THE WESTERN GULF OF MEXICO WILL MAINTAIN LIGHT TO MODERATE SOUTHEAST TO SOUTH WINDS AND LOW TO MODERATE SEAS. HOWEVER...SMALL CRAFT WILL NEED TO EXERCISE CAUTION ON THE LAGUNA MADRE THIS AFTERNOON DUE TO A SLIGHTLY STRONGER WINDS. THURSDAY NIGHT THROUGH TUESDAY...GENERALLY LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS ARE EXPECTED THROUGH THE PERIOD AS WEAK LOW PRESSURE PERSISTS OVER THE WESTERN GULF OF MEXICO AND A COLD FRONT INTRUDES INTO THE LOWER TEXAS COASTAL WATERS. WEAK CLOSED LOW PRESSURE MAY DEVELOP ALONG THE LOWER TEXAS COAST TOWARDS THE END OF THE FORECAST PERIOD PER ONE WEATHER FORECAST MODEL...BUT THE STRONGER WINDS AND HIGHER SEAS INDICATED IN ASSOCIATION WITH THE LOW PRESSURE DEVELOPMENT HAVE NOT BEEN INCLUDED IN THE FORECAST AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 92 80 91 79 / 30 20 30 20 BROWNSVILLE 93 79 93 79 / 30 20 30 20 HARLINGEN 96 78 95 78 / 30 20 30 20 MCALLEN 98 80 97 78 / 20 10 20 20 RIO GRANDE CITY 100 78 98 77 / 10 10 30 20 SOUTH PADRE ISLAND 87 82 88 80 / 30 30 40 30 && .BRO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV SHORT TERM...CACERES-63 LONG TERM...TOMASELLI-66
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
119 AM CDT WED SEP 9 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...LIGHT SOUTHEAST WINDS WITH A FEW PASSING CLOUDS PREVAIL OVER DEEP SOUTH TEXAS EARLY THIS MORNING. VFR CONDITIONS EXPECTED TO CONTINUE THROUGH MID MORNING. LOW TO MID LEVEL MOISTURE WILL INCREASE ACROSS THE AREA TODAY AS A 500MB LOW MOVES ACROSS THE WESTERN GULF OF MEXICO. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE EASTERN PORTIONS OF THE CWA ALONG AND AHEAD OF THE SEABREEZE FRONT MOVING INLAND THIS AFTERNOON. LIGHT SOUTHEAST WINDS OVERNIGHT WILL BECOME MODERATE LATER THIS MORNING WITH GUSTS AROUND 20 KNOTS IN THE AFTERNOON. && .PREV DISCUSSION... /ISSUED 636 PM CDT TUE SEP 8 2015/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE MOSTLY CLEAR SKIES ACROSS THE CWA EARLY THIS EVENING. EXPECT VFR CONDITIONS TO PREVAIL THE REST OF THE EVENING INTO EARLY WED MORNING AS NORTHERLY WINDS ALOFT CONTINUE TO PROVIDE SUBSIDENCE ACROSS THE RIO GRANDE VALLEY. A 500MB LOW ACROSS THE NORTH CENTRAL GULF OF MEXICO WILL MOVE ACROSS THE WESTERN GULF OF MEXICO WEDNESDAY. THIS WILL ALLOW LOW TO MID LEVEL MOISTURE TO INCREASE ACROSS THE COASTAL SECTIONS OF THE CWA. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE EASTERN PORTIONS OF THE CWA ALONG AND AHEAD OF THE SEABREEZE FRONT MOVING INLAND WED AFTERNOON. PREV DISCUSSION... /ISSUED 300 PM CDT TUE SEP 8 2015/ SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/... AN ACTIVE SEA BREEZE IS MOVING SLOWLY INLAND THIS AFTERNOON. THE HRRR SUGGESTS THAT IT WILL PUSH INTO THE MID VALLEY. DRIER AIR IS STILL IN PLACE FARTHER WEST. SKIES SHOULD BECOME MOSTLY CLEAR TONIGHT. WV IMAGERY SHOWS A MID LEVEL CIRCULATION SOUTH OF LOUISIANA...WHICH IS PROGGED TO DRIFT SOUTHWEST TOWARD THE AREA. THUS...LOOK FOR CONTINUED UNSETTLED CONDITIONS OVER THE GULF...WITH A FEW SHOWERS TRANSLATING FARTHER WEST OVER THE COAST TONIGHT. THE NAM SHOWS DRIER AIR AGAIN OUT WEST ON WEDNESDAY...SO WILL ANTICIPATE SIMILAR CONDITIONS AS TODAY WITH MAYBE A LITTLE MORE ACTIVITY OVER THE COASTAL AREAS. THE MOISTURE POOLING ALONG AND AHEAD OF A FRONT MOVING SOUTH OVER CENTRAL TEXAS WILL NOT BE FAR ENOUGH SOUTH TO CAUSE A MAJOR PROBLEM IN THE SHORT TERM...EXCEPT PERHAPS FOR A FEW SHOWERS OVER THE FAR NORTHWEST... ZAPATA COUNTY...WEDNESDAY NIGHT. LONG TERM /THURSDAY THROUGH TUESDAY/... H5 TROUGH REMAINS BOTTLED BETWEEN 2 RIDGES...WITH THE AXIS REMAINING TO THE EAST ON THURSDAY. THIS WILL KEEP THE REGION ON THE DRIER WEST SIDE THURSDAY AND INTO FRIDAY. FRIDAY BRINGS THE TROUGH AXIS WESTWARD AS THE OVERALL TROUGH DEEPENS. AN INCREASE IN MOISTURE FROM THE SOUTH WILL BEGIN TO RAMP UP POPS LATER FRIDAY AFTERNOON. GOOD DEEP MOISTURE AND INSTABILITY COMBINES ON SATURDAY FOR A GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS. SUNDAY INTO MONDAY A WEAK COLD FRONT TRIES TO MOVE SOUTHWARD INTO SOUTH TEXAS. THE MAIN ISSUE IS SOUTHWARD MOVING DRIER AIR AND HOW FAR SOUTH IT WILL REACH...CLASHING WITH GULF MOISTURE MOVING BACK TO THE NORTH. CONTINUING WITH A GOOD CHANCE FOR THUNDERSTORMS BOTH DAYS AS INSTABILITY REMAINS DECENT. QUESTION MARKS CROP UP STARTING EARLY NEXT WEEK AS MODELS DIFFER ON WHAT HAPPENS TO THE REMNANTS OF THE FRONT. NEEDLESS TO SAY...A DEGRADING FRONT HOVERING IN THE WESTERN GULF NEEDS TO HAVE A CLOSE EYE KEPT ON IT. FOR NOW...THE LOCALIZED INSTABILITY RAIN CHANCES CONTINUE TUESDAY INTO WEDNESDAY...ESPECIALLY CLOSER TO THE COAST...AS WE MOVE INTO OUR CLIMATOLOGICALLY WETTEST WEEK OF THE ENTIRE YEAR. MARINE... A WEAK PRESSURE GRADIENT WILL CAUSE LIGHT TO MODERATE SOUTHEAST TO SOUTH WINDS AND LOW TO MODERATE SEAS TO PERSIST ALONG THE LOWER TEXAS COAST. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV 63
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
909 PM CDT THU SEP 10 2015 .UPDATE... 00Z NAM SHOWS A SOMEWHAT SLOWER AND WEAKER PUSH OF NORTHEAST WINDS DOWN THE LAKE. HOWEVER LATEST HRRR EXPERIMENTAL IS STILL SHOWING STRONGER WINDS. WILL ADJUST WINDS ONCE THE 00Z DATASET IS INCORPORATED IN THE MESO MODELS. THIS WILL ALLOW SOME PATCHY DENSE FOG...ESPECIALLY IN LOW AREAS AND RIVER VALLEYS. 00Z NAM SHOWS AN ELEVATED NON TORNADO INDEX VALUES OVER LAKE MICHIGAN NEAR SHEBOYGAN BETWEEN 4 AM AND 7 AM CDT THEN PUSHING SOUTH DURING THE MORNING HOURS. BY AFTERNOON THE HIGHEST VALUES ARE SOUTH OF MILWAUKEE BUT REMAIN SOMEWHAT ELEVATED INTO FRIDAY NIGHT ALONG THE SHORE AREAS. THIS HAS BEEN A GOOD INDICATOR TO WATERSPOUT POTENTIAL. && .AVIATION/06Z TAFS/... PATCHY IFR/LIFR FOG IN LOW AREAS AND RIVER VALLEYS UNTIL NORTH WINDS INCREASE DURING THE MORNING HOURS. A BAND OF MVFR CIGS POSSIBLE NEAR LAKE MICHIGAN WITH THE SURGE OF HIGHER NORTH WINDS EXPECTED LATE TONIGHT AND FRIDAY MORNING. OTHERWISE MAINLY VFR CIGS ON FRIDAY WITH A STRATOCUMULUS DECK DUE TO THE MID LEVEL COLD TROUGH. && .MARINE... NORTH TO NORTHEAST WINDS WILL INCREASE LATER TONIGHT AS HIGH PRESSURE BUILDS SOUTH INTO THE REGION AND LOW PRESSURE PUSHES OFF TO THE EAST. WAVES WILL BUILD TO 3 TO 6 FEET BY FRIDAY. WINDS WILL SUBSIDE BY FRIDAY EVENING BUT WAVES WILL TAKE A BIT LONGER TO SUBSIDE. A SMALL CRAFT REMAINS IN EFFECT FOR LATER TONIGHT THROUGH FRIDAY NIGHT. THERE WILL BE A WATERSPOUT POTENTIAL NORTH OF PORT WASHINGTON LATE TONIGHT AND ACROSS THE WATERS FRIDAY INTO FRIDAY NIGHT. && .PREV DISCUSSION... /ISSUED 250 PM CDT THU SEP 10 2015/ TONIGHT...FORECAST CONFIDENCE IS MEDIUM. MOST OF THE PRECIP HAS ENDED ACROSS THE FORECAST AREA WHILE THE SURFACE COLD FRONT IS CURRENTLY WORKING THROUGH THE FAR SOUTHEAST...IT WILL BE OUT OF WI BY EARLY EVENING. THE HRRR AND MOST OF THE MODELS KEEP THE AREA DRY THROUGH ABOUT 4 AM TONIGHT. THE ONLY THREAT WOULD BE ACROSS THE FAR SOUTH AND EAST WHERE SOME WEAK TROUGHING CONTINUES. WILL ONLY KEEP SLIGHT CHANCES THERE STRONG COLD ADVECTION KICKS IN LATER TONIGHT AND WINDS TURN NORTHEAST. DELTA T/S START TO CLIMB TOWARD SUNRISE AND THE ADVECTING MOIST MARINE LAYER OFF LAKE MICHIGAN WILL CERTAINLY INCREASE CLOUDS AND COULD BRING SOME LIGHT SHOWERS/SPRINKLES TO THE EAST AT THAT TIME. FRIDAY...FORECAST CONFIDENCE IS MEDIUM. A SHARP MID LEVEL TROUGH WILL BE ROTATING ACROSS THE AREA AND THE SETUP MENTIONED FOR LATE TONIGHT WILL JUST STRENGTHEN. DELTA T/S WILL MAX TO AROUND 15-17C AND THE CONVECTIVE CLOUD DEPTH COULD BE PUSHING 15-17KFT. IT LOOKS LIKE THE BEST AXIS FOR LAKE EFFECT SHOWERS WILL BE STAYING JUST OFF SHORE. THIS WILL HAVE TO BE WATCHED CLOSELY AS IT EVOLVES. THE COLD AIR ALOFT COUPLED WITH DEEP CYCLONIC FLOW SHOULD BRING AT LEAST A SMALL CHANCE OF SHOWERS TO MOST PLACES ON FRIDAY. FOR THOSE NEAR LAKE MICHIGAN...THERE IS A RISK OF WATERSPOUTS AS THE COLD AIR FLOWS DOWN THE WARMER WATERS OF LAKE MICHIGAN. FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE...MEDIUM THE AXIS OF THE UPPER LEVEL TROUGH WILL EXIT THE SOUTHEAST FORECAST AREA FRIDAY EVENING...POSSIBLY BRINGING A FEW MORE SHOWERS EAST DURING THE EVENING HOURS. PRETTY CHILLY AIR ALOFT WILL CONTINUE TO POUR INTO THE AREA OVERNIGHT...WITH 850 MB TEMPS FALLING TO AROUND 2C BY SATURDAY MORNING. THIS WILL LIKELY RESULT IN LAKE EFFECT RAIN SHOWERS. MEAN SURFACE TO 850 MB FLOW IS NORTHERLY..SO THINK THESE SHOWERS WILL LIKELY NOT AFFECT SOUTHERN WISCONSIN. DRY WEATHER IS THUS EXPECTED SATURDAY. KEPT MOSTLY SUNNY SKIES FOR SATURDAY WITH DRIER AIR IN PLACE...BUT WONDER IF MODELS ARE NOT CATCHING DIURNAL CUMULUS POTENTIAL WITH PRETTY COOL TEMPS LINGERING ALOFT. HIGH TEMPS WILL REMAIN WELL BELOW NORMAL IN THE LOW TO MID 60S. SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...HIGH STRONG HIGH PRESSURE OVER THE EASTERN UNITED STATES SHOULD RESULT IN DRY WEATHER FOR SOUTHERN WISCONSIN SUNDAY THROUGH TUESDAY. SOUTHERLY WINDS WILL BE IN PLACE WITH THE HIGH TO THE EAST...WHICH WILL RESULT IN A WARMING TREND DURING THIS PERIOD. EXPECT HIGHS TO GET BACK TO AROUND 80 BY TUESDAY. WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...MEDIUM A TROUGH OF LOW PRESSURE AND ASSOCIATED COLD FRONT WILL APPROACH THE AREA WEDNESDAY. RIGHT NOW...LOOKS LIKE THE SYSTEM WILL REMAIN FAR ENOUGH WEST FOR DRY WEATHER DURING THE DAYTIME HOURS...SO CUT BACK ON POPS. HAVE HIGHER POPS FOR SHOWERS/STORMS THEN SPREAD OUT BETWEEN WEDNESDAY NIGHT AND THURSDAY...WITH THE GFS AND ECMWF DIFFERING IN THE TIMING OF THE FRONT BY 12 HOURS OR SO. WITH WEDNESDAY CURRENTLY PROGGED TO BE DRY DURING THE DAY...BUMPED TEMPS UP A BIT INTO THE LOWER 80S MOST PLACE. FORECAST HIGHS MAY STILL BE TOO COOL GIVEN MODEL 925 MB TEMPS IN THE 22-24C RANGE. SHOULD BE COOLER THURSDAY AS THE FRONT MOVES THROUGH THE AREA. AVIATION/00Z TAFS/... MVFR CIGS DEVELOPED IN THE WAKE OF THE COLD FRONT MOVING SOUTHEAST THROUGH THE AREA THIS AFTERNOON...THESE SHOULD DISSIPATE LATER THIS AFTERNOON. THEN VFR CONDITIONS ARE EXPECTED UNTIL ABOUT 08Z FRI. THEREAFTER...COLD AIR WILL BE FLOWING SOUTH INTO THE AREA AND WILL COMBINE WITH LINGERING MOISTURE...AND A WARMER/MOIST MARINE LAYER FLOWING IN FROM LAKE MICHIGAN...TO BRING MVFR TO POSSIBLY IFR CIGS TO ALL THE TAF SITES CENTERED AROUND 08-13Z FRI. THEREAFTER...CIGS SHOULD GRADUALLY LIFT BACK TO VFR LEVELS. IT SHOULD BE MOSTLY DRY TONIGHT...WITH SHOWER CHANCES RETURNING LATER TONIGHT AND FRIDAY WITH THE COLD AIR ADVECTION. THERE IS A CHANCE OF WATERSPOUTS OUT OVER LAKE MICHIGAN FROM ABOUT 09Z THROUGH THE DAY ON FRIDAY. MARINE... NORTH TO NORTHEAST WINDS INCREASE LATER TONIGHT AS HIGH PRESSURE BUILDS SOUTH INTO THE REGION AND LOW PRESSURE PUSHES OFF TO THE EAST. WAVES WILL BUILD TO 3 TO 6 FEET BY FRIDAY. WINDS WILL SUBSIDE BY FRIDAY EVENING BUT WAVES WILL TAKE A BIT LONGER TO SUBSIDE. A SMALL CRAFT REMAINS IN EFFECT FOR LATER TONIGHT THROUGH FRIDAY NIGHT. THERE IS A SLIGHT CHANCE OF WATER SPOUTS FROM 4AM TONIGHT THROUGH FRIDAY AFTERNOON DUE IN PART TO COLD AIR FLOWING SOUTH ACROSS THE WARM WATERS OF LAKE MICHIGAN. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 4 AM FRIDAY TO 7 AM CDT SATURDAY FOR LMZ645-646. SMALL CRAFT ADVISORY FROM 1 AM FRIDAY TO 7 AM CDT SATURDAY FOR LMZ643-644. && $$ UPDATE...HENTZ TONIGHT/FRIDAY AND AVIATION/MARINE...DAVIS FRIDAY NIGHT THROUGH THURSDAY...DDV
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
645 PM CDT THU SEP 10 2015 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 243 PM CDT THU SEP 10 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD FRONT STRETCHING FROM ABOUT IRON MOUNTAIN TO WAUSAU EARLY THIS AFTERNOON. SHOWERS AND STORMS HAVE DEVELOPED ALONG IT OVER THE UPPER PENINSULA...BUT ONLY A FEW BLIPS SHOWING UP ON RADAR OVER NORTHERN WI SO FAR. SB CAPE HAS BEEN BUILDING AHEAD OF THE FRONT AND THE HRRR/ARW CONTINUE TO DEVELOP SCT SHOWERS LATER THIS AFTERNOON. ALTHOUGH BROUGHT DOWN PRECIP CHANCES SLIGHTLY THIS AFTERNOON...DATA DOES NOT SUPPORT DROPPING THEM ENTIRELY. WILL KEEP A SCATTERED MENTION MID-AFTERNOON INTO THE EARLY EVENING. BEHIND THE FRONT...AN UPPER TROUGH IS DIGGING SOUTHWARD OVER ONTARIO AND MINNESOTA...BRINGING WIDESPREAD CLOUDS AND SHOWERS WITH IT. FORECAST CONCERNS INCLUDE PRECIP AND CLOUDS TRENDS. TONIGHT...THE COLD FRONT WILL STALL OVER NORTHEAST WI FOR A PERIOD THIS EVENING AS IT WAITS FOR A SHORTWAVE OVER NORTHERN MINNESOTA TO ARRIVE. THEN THE SHORTWAVE WILL GIVE THE FRONT A PUSH TO THE SOUTH LATE OVERNIGHT. DUE TO THE SLOW DEPARTURE OF THE FRONT...WILL KEEP A SMALL CHANCE OF A SHOWER OVER NE WI UNTIL LATE TONIGHT. OTHERWISE...THE SHORTWAVE WILL BRING AN INFLUX OF LOW STRATUS SOUTHEAST FROM NORTHERN MINNESOTA AND WESTERN ONTARIO. 850MB TEMPS WILL FALL TO AROUND +1C OVER WESTERN LAKE SUPERIOR...WHICH WILL CREATE DELTA T/S OF AROUND 14C...SUFFICIENT OF LAKE EFFECT RAIN SHOWERS TO DEVELOP. THEREFORE...AFTER A DRY START TO THE EVENING....NORTH-CENTRAL WISCONSIN SHOULD SEE CLOUDS INCREASE AND SHOWERS MOVE IN AFTER MIDNIGHT. LOWS TO FALL INTO THE MID 40S NORTH TO LOW 50S SOUTH. FRIDAY...THE UPPER TROUGH WILL MOVE OVERHEAD...BRINGING A COOL AND CLOUDY AIRMASS WITH IT. THE MAIN VORT MAX WILL BE EXITING NORTHEAST WISCONSIN AROUND MIDDAY...WHICH IS PERHAPS A REASON WHY MODELS ARE UNENTHUSIASTIC ABOUT PRECIP CHANCES. HOWEVER...MODELS PROJECT A NEARLY SATURATED LAYER UP TO ABOUT 700MB WITH STEEP LOW LEVEL LAPSE RATES IN THE BL. SO THEREFORE THINK WILL SEE SCT LIGHT SHOWER DEVELOP ACROSS MUCH OF THE AREA BY LATE MORNING AND PEAKING AROUND EARLY AFTERNOON. SOME DRIER AIR MOVING IN FROM THE NORTH MAY CAUSE SHOWERS TO DIMINISH THERE FIRST...AWAY FROM THE LAKE EFFECT BELTS. WITH PLENTY OF CLOUDS...HIGHS TO ONLY REACH FROM THE MID 50S NORTH TO LOW 60S SOUTH. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 243 PM CDT THU SEP 10 2015 HIGH PRESSURE WILL BUILD IN ACROSS THE WESTERN GREAT LAKES DURING THE WEEKEND...DRYING OUT THE WEATHER OVER NORTHEAST WISCONSIN. HOWEVER IN ADDITION TO DRY WEATHER THE HIGH WILL BRING COOL TEMPERATURES AS 850 MB TEMPERATURES FALL INTO THE SINGLE DIGITS ABOVE ZERO. AS THE HIGH BUILDS IN...CLOUDS WILL CLEAR OUT AND SURFACE WINDS WILL BECOME LIGHT...MAKING FOR IDEAL RADIATIVE COOLING CONDITIONS. THIS WILL LIKELY PRODUCE AREAS OF FROST ON FRIDAY NIGHT ACROSS NORTH CENTRAL WISCONSIN...WITH PATCHY FROST ACROSS THE SAME AREA SATURDAY NIGHT. OF THESE TWO NIGHTS IT LOOKS LIKE FRIDAY NIGHT WILL BE THE COOLER OF THE TWO NIGHTS...WITH AN ADVISORY BEING A POSSIBILITY AS LOWS DROP INTO THE MIDDLE 30S. THERE WILL BE SOME RETURN FLOW SATURDAY NIGHT WITH SLIGHTLY WARMER TEMPERATURES AS LOWS ONLY DROP TO AROUND 40 DEGREES. HIGHS THIS WEEKEND WILL BE SEVERAL DEGREES BELOW NORMAL...WITH TEMPERATURES ONLY EXPECTED TO GET INTO THE 60S. RETURN FLOW ON THE BACKSIDE OF THE HIGH WILL ALLOW DAYTIME TEMPERATURES TO REBOUND BACK INTO THE 70S...CLOSE TO NORMAL FOR THIS TIME OF YEAR...DURING THE EARLY PART OF NEXT WEEK AS THE HIGH CONTINUES TO PROVIDE DRY WEATHER ACROSS THE WESTERN GREAT LAKES REGION. THE NEXT CHANCE FOR RAIN WILL NOT OCCUR UNTIL WEDNESDAY AND THURSDAY AS A LOW PRESSURE SYSTEM DEVELOPS ACROSS THE PLAINS AND HEADS EAST THROUGH THE GREAT LAKES REGION. WITH THE HIGH IN PLACE ACROSS THE EAST FEEDING IN DRY AIR IT WILL MAKE THE EASTWARD PROGRESS OF THE LOW RATHER SLOW. WITH THIS IN MIND IT APPEARS THE SLOWER ECMWF SOLUTION IS PREFERRED TO THE QUICKER GFS MODEL. HIGHS DURING THIS PERIOD AHEAD OF THE COLD FRONT SHOULD STAY IN THE 70S ACROSS NORTHEAST WISCONSIN. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 639 PM CDT THU SEP 10 2015 SHOWERS AND ISOLD TSTMS WILL DIMINISH OVER NORTHEAST WI EARLY THIS EVENING...AS A COLD FRONT MOVES THROUGH THE AREA. VFR CONDITIONS SHOULD PREVAIL FOR MOST OF THE NIGHT...THOUGH SOME LAKE-ENHANCED CLOUDS AND MVFR CIGS SHOULD DEVELOP OVER NORTH CENTRAL WI OVERNIGHT. AN UPPER LEVEL TROUGH WILL COMBINE WITH DAYTIME HEATING TO PRODUCE SCT SHOWERS AND MVFR OR LOW-END VFR CONDITIONS ACROSS MUCH OF THE AREA ON FRIDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KURIMSKI AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
208 PM CDT WED SEP 9 2015 .SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT) ISSUED AT 208 PM CDT WED SEP 9 2015 BIG PICTURE WATER VAPOR IMAGERY/RAP ANALYSIS SHOWING A CLOSED UPPER LOW OVER WESTERN ONTARIO WITH A BROAD TROUGH OVER THE NORTHER/CENTRAL CONUS. AN EMBEDDED MID-LEVEL SHORTWAVE TROUGH WAS PUSHING INTO MN/DAKOTAS. RADAR MOSAIC SHOWING SCATTERED BAND OF SHOWERS AND THUNDERSTORMS AHEAD OF THIS WAVE EXTENDING FROM NORTHWEST WI/EAST CENTRAL MN TO SOUTH CENTRAL MN...MOVING EAST AT 35- 40KT. OTHERWISE...TEMPERATURES AS OF 2 PM RANGED FROM NEAR 70 ACROSS NORTH CENTRAL WI...TO THE 75-80 DEGREE RANGE ALONG AND SOUTH OF I-90. FOR THIS EVENING OVERNIGHT...WILL BE WATCHING THE WAVE CONTINUE MOVING EAST ACROSS OUR AREA. RAP DEPICTING INCREASING 850-700MB MOISTURE TRANSPORT ALONG WITH INCREASING MUCAPE...HIGHER 500-1000 J/KG SOUTH OF I-90. THEREFORE CARRIED SHRA/TS ALONG AND SOUTH OF I- 90 WITH ISOLATED THUNDER NORTH. MOST MESO MODELS DEPICTING SCATTERED NATURE TO THIS CONVECTION...SO MAINTAINED 30-50 POPS FOR NOW. ANOTHER STRONGER MID-LEVEL WAVE/DECENT 500-300MB PV-ADVECTION PUSHES IN ACROSS THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY BY TOMORROW MORNING AND IS EXPECTED TO REINFORCE SHOWER/THUNDER CHANCES ACROSS THE AREA. WITH EXPECTED SCATTERED CONVECTION AND CLOUD COVER...WILL SEE COOLER TEMPERATURES WITH HIGHS ACROSS NORTH CENTRAL WI ONLY IN THE 65-70 DEGREE RANGE AND LOW-MID 70S SOUTH OF I-90. LOOKS LIKE SHOWER/ISOLATED THUNDER CHANCES PUSH OUT OF THE AREA BY LATER THURSDAY EVENING WITH CLEARING SKIES THROUGH THE OVERNIGHT HOURS. WITH DEEPENING MID/UPPER LEVEL TROUGH OVERHEAD AND RATHER COLD 850MB TEMPS DROPPING INTO THE 1-5C RANGE...WILL SEE OVERNIGHT LOWS DIP INTO THE 40S MOST LOCATIONS. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 208 PM CDT WED SEP 9 2015 FOR FRIDAY THROUGH SATURDAY NIGHT... ANOTHER EMBEDDED SHORTWAVE TROUGH COMES DOWN ACROSS THE AREA ON FRIDAY. STEEP LOW TO MID-LEVEL LAPSE RATES EXPECTED TO GENERATE QUITE A BIT OF CUMULUS AND SCATTERED SHOWERS...MAINLY ALONG AND EAST OF THE MISSISSIPPI RIVER. OTHERWISE...A RATHER CHILLY AUTUMN-LIKE DAY ON TAP AS HIGHS ONLY TOP OFF IN THE UPPER 50S TO THE MIDDLE 60S. CHILLY DAY FRIDAY AND CLEARING SKIES FRIDAY NIGHT AS SURFACE HIGHS SETTLES IN WILL SET THE STAGE FOR COLD TEMPERATURES FRIDAY NIGHT WITH LOWS DIPPING INTO TO THE UPPER 30S/AROUND 40 ACROSS NORTH CENTRAL WI...TO THE LOWER/MIDDLE 40S ELSEWHERE. MODELS SHOW THE MID-LEVEL TROUGH PUSHING INTO THE EASTERN GREAT LAKES/OHIO RIVER VALLEY SATURDAY AS MID-LEVEL RIDGE BUILD INTO OUR REGION. THIS WILL PROVIDE DRY AND SLIGHTLY WARMER //BUT STILL WELL BELOW NORMAL// TEMPERATURES IN THE LOW-MID 60S UNDER MOSTLY SUNNY SKIES. PLAN ON ANOTHER CLEAR AND COLD SATURDAY NIGHT WITH SURFACE HIGH OVERHEAD. LOOKS TO BE AN IDEAL RIVER VALLEY/BOG AREA FOG NIGHT WITH OVERNIGHT LOWS DIPPING INTO THE 40S ONCE AGAIN. DID NOT INCLUDE IN THE WEATHER GRIDS FOR NOW AS EXACT RIDGE LOCATION COULD CHANGE A BIT...BUT SOMETHING TO KEEP AN EYE ON NONETHELESS. FOR SUNDAY THROUGH WEDNESDAY...DAYS 4 TO 7... GFS AND ECMWF IN AGREEMENT ON A WARMING TREND FOR THIS PERIOD AS LOW PRESSURE LIFT ACROSS THE NORTHERN PLAINS INTO CANADA. THIS PUTS US IN WARM SECTOR WITH BROAD-SCALE LIFT ACROSS OUR AREA FOR A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY IN THE TUESDAY NIGHT THROUGH WEDNESDAY TIME FRAME. LOOKS LIKE HIGHS ON SUNDAY IN THE 65-70 DEGREE RANGE...WARMING BACK INTO THE 70S...OR NEAR SEASONAL NORMALS...BY WEDNESDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON) ISSUED AT 1230 PM CDT WED SEP 9 2015 MAIN TAF CONCERNS ARE SHOWERS/THUNDERSTORM CHANCES AT BOTH RST/LSE TAF SITES THIS EVENING INTO THURSDAY MORNING. A WEAK UPPER LEVEL DISTURBANCE OVER WESTERN MINNESOTA WILL MOVE OVER THE RST/LSE TAF SITES LATE THIS AFTERNOON INTO THURSDAY MORNING. THE LATEST 09.12Z RAP/NAM SUGGEST WEAK MOISTURE CONVERGENCE AND VERTICAL MOTION IN ASSOCIATION WITH THE UPPER LEVEL DISTURBANCE. DRY AIR ALOFT AND NEAR THE SURFACE WILL ALLOW CLOUD HEIGHTS TO REMAIN ABOVE THE MVFR CONDITIONS FOR THE MAJORITY OF THE TAF PERIOD. WITH THE FAST PROGRESSION OF THE UPPER LEVEL DISTURBANCE...CEILING HEIGHTS MAY BRIEFLY LOWER TO MVFR BETWEEN THE 03Z-10Z THURSDAY TIME FRAME. EXPECT VFR CONDITIONS TO PREVAIL AT BOTH TAF SITES THROUGH TAF PERIOD. THUNDERSTORM PROBABILITIES REMAIN VERY LOW AT TAF SITES...AS THE 09.12Z NAM/RAP SUGGEST LIMITED ELEVATED INSTABILITY WITH THE UPPER LEVEL DISTURBANCE. WILL KEEP MENTION OF THUNDER OUT OF TAF PERIOD...DUE TO THIS LIMITED INSTABILITY AND ISOLATED TO SCATTERED COVERAGE OF CONVECTION. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM....DAS AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS TAUNTON MA
455 AM EDT FRI SEP 11 2015 .SYNOPSIS... LOW PRESSURE FROM THE MID ATLANTIC WILL MOVE NORTHEAST ALONG A FRONT PAST OUR AREA THIS MORNING...THEN PULL THIS FRONT OUT TO SEA TONIGHT. WEAK HIGH PRESSURE WILL BRING DRY AND MILD CONDITIONS SATURDAY. MORE WET WEATHER RETURNS SUNDAY INTO EARLY MONDAY AS ANOTHER LOW PRESSURE AREA MOVES ACROSS...BUT WILL NOT SEE A TOTAL WASHOUT. LARGE HIGH PRESSURE WILL BUILD ACROSS THE NORTHEAST THROUGH MID AND LATE NEXT WEEK...BRINGING ANOTHER AROUND OF DRY AND WARM WEATHER. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 455 AM UPDATE... CANCELED THE REMAINDER OF THE FLASH FLOOD WATCH ACROSS RI AND SOUTHEAST MA. WHILE STILL RAINING ACROSS THESE AREAS...THE INTENSITY IS JUST NOT THERE WHERE ANYTHING BEYOND NUISANCE POOR- DRAINAGE FLOODING WILL BE A CONCERN THROUGH DAYBREAK. AXIS OF HEAVIEST RAINFALL ALREADY MOVING OFFSHORE THIS MORNING. GREATEST SYNOPTIC LIFT WILL BE MAINLY EAST OF SOUTHERN NEW ENGLAND BETWEEN 6-10 AM THIS MORNING. MOISTURE WILL TAKE A LITTLE WHILE LONGER TO DIMINISH...BUT SHOULD DO SO LATER TODAY. OF ALL THE GUIDANCE...THOUGHT THE 11/05Z HRRR BEST CAPTURED THE TIMING...AND MATCHED UP BEST WITH OBSERVED RADAR TRENDS. THAT WAS THE BASIS FOR THE RAINFALL THIS MORNING. STILL PLENTY OF CLOUDS TODAY...SO FORECASTING SEASONABLE TEMPERATURES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/... LOW PRESSURE MOVES FARTHER FROM OUR REGION. STILL DEALING WITH A MID LEVEL TROUGH...WHICH WILL STEER A SHORTWAVE OUR WAY LATE. THE BIG QUESTION IS HOW MUCH MOISTURE TO WORK WITH. RIGHT NOW... THINKING THERE WILL BE ENOUGH FOR SOME CLOUDS...BUT NOT FOR RAINFALL. KEEPING THE FORECAST FOR TONIGHT DRY. && .LONG TERM /SATURDAY THROUGH THURSDAY/... HIGHLIGHTS... * DRY CONDITIONS EXPECTED SATURDAY * PERIODS OF WET WEATHER SUNDAY INTO EARLY MONDAY AS LOW PRESSURE * HIGH PRES RETURNS WITH DRY AND WARM CONDITIONS INTO LATE NEXT WEEK OVERVIEW... MODELS AND ENSEMBLES CONTINUE TO SIGNAL LONG WAVE TROUGH WITH CUTOFF H5 LOW PRES DIGGING ACROSS THE GREAT LAKES THAT WILL SHIFT NE DURING SUNDAY-MONDAY TIMEFRAME. SOME TIMING ISSUES REMAIN IN PUSHING THE ASSOCIATED SURFACE LOW ACROSS THE REGION...BUT EXPECT THIS TO SHIFT NE BY MID TO LATE DAY MONDAY. WITH LIGHT BUT STEADY ONSHORE WIND IN PLACE ALONG WITH PWATS UP TO 1.9 INCHES CROSSING THE REGION. THIS COULD BRING A FEW PERIODS OF HEAVY RAINFALL MAINLY ACROSS THE WESTERN CT VALLEY INTO THE E SLOPES OF THE BERKSHIRES WITH LOW LEVEL UPSLOPE WIND FLOW. BEYOND THIS...MEDIUM RANGE GUIDANCE REMAINS REMARKABLY CONSISTENT IN REDEVELOPING LONG WAVE RIDGING ACROSS THE EASTERN THIRD OF THE NATION WHILE LONG WAVE TROUGH DIGS OUT WEST. THIS WILL BRING A RETURN OF DRY AND INCREASINGLY WARM CONDITIONS INTO LATE NEXT WEEK. DETAILS... SATURDAY...WILL SEE DRY AND MILD CONDITIONS AS WEAK HIGH PRES CROSSES THE REGION. MAY SEE LEADING EDGE OF SHOWERS PUSH INTO E SLOPES OF THE BERKSHIRES INTO THE CT VALLEY SAT AFTERNOON...WITH AN ISOLD THUNDERSTORM OR TWO POSSIBLE. SUNDAY-MONDAY...UPPER LEVEL LONG WAVE TROUGH AND CUTOFF LOW WILL LIFT NE AS IT TENDS TO FLATTEN OUT LATE SUNDAY INTO MONDAY. SURFACE LOW PRES AND FRONT WILL PUSH ACROSS. BEST SHOT FOR STEADIER PRECIP WILL OCCUR SUNDAY AFTERNOON AND NIGHT...MAINLY ACROSS WESTERN AREAS. SHOULD SEE IMPROVING CONDITIONS BEGINNING ACROSS N CT/RI DURING THE PRE DAWN HOURS MONDAY THEN WILL PUSH STEADILY NE. SOME SHOWERS MAY LINGER INTO THE AFTERNOON ACROSS N MA AROUND THE ROUTE 2 AREA. COLD POOL WILL PASS N AND W OF THE REGION...SO TEMPS WILL BE COOLER DURING THE DAY MONDAY WITH HIGHS IN THE LOWER-MID 70S. MAY SEE UP TO AN INCH OF RAIN ACROSS THE E SLOPES OF THE BERKSHIRES FROM THIS SYSTEM...RANGING TO ABOUT 0.50 INCHES ALONG E COAST BEFORE ENDING DURING MONDAY. TUESDAY-THURSDAY...MORE DRY AND WARMING CONDITIONS WILL BE THE RULE ACROSS THE REGION AS LARGE SURFACE HIGH PRES TAKES OVER. EXPECT TEMPS TO BE RUNNING UP TO 10 DEGREES ABOVE SEASONAL NORMALS BY THURSDAY WITH SOME RECORD HIGHS POSSIBLE. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/... THROUGH 12Z...MODERATE CONFIDENCE. CONFIDENT MVFR-VLIFR MIX WITH CIGS ACROSS MOST OF SOUTHERN NEW ENGLAND. LOWER CONFIDENCE WITH VSBYS BUT EXPECT IFR WITH ANY SHRA/+SHRA. FOG ALONG WITH LIFR-VLIFR CIGS LIKELY AN ISSUE FOR S /SE-COASTAL TERMINALS. GREATER TSRA RISK WILL BE OVER THE COASTAL WATERS. TODAY...MODERATE CONFIDENCE. IMPROVEMENT BEGINNING DURING THIS MORNING TOWARDS VFR. NE WINDS INCREASING AND GUSTING TO 20 KTS ALONG THE COASTS. TONIGHT...HIGH CONFIDENCE. EXPECTING MVFR-LIFR FOG DEVELOPMENT ESPECIALLY OVER THE INTERIOR TOWARDS MORNING. TYPICALLY PRONE TERMINALS WITHIN SHELTERED VALLEYS LIKELY TO EXPERIENCE LIGHT WINDS OVERNIGHT LIKE THE CT RIVER VALLEY ESPECIALLY PRONE. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING ISSUES. HIGH CONFIDENCE IN TRENDS. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING ISSUES. HIGH CONFIDENCE IN TRENDS. OUTLOOK /SATURDAY THROUGH TUESDAY/... SATURDAY...HIGH CONFIDENCE. PATCHY FOG EARLY SAT MORNING WITH LOCAL MVFR-IFR VSBYS THROUGH MID MORNING...OTHERWISE VFR. WINDS BECOME LIGHT S-SE. MAINLY DRY FORECAST...THOUGH MAY SEE SCT SHOWERS MOVE INTO WESTERN MA/CT LATE IN THE DAY. SATURDAY NIGHT THROUGH SUNDAY NIGHT...MODERATE CONFIDENCE. AREAS OF MVFR-IFR CONDITIONS WITH SHOWERS LIKELY ACROSS THE REGION. LOW CHANCE FOR ISOLD THUNDERSTORMS SAT NIGHT THROUGH MIDDAY SUNDAY. PATCHY FOG POSSIBLE. MAY ALSO CONTEND WITH SOME LLWS IMPACTS. MAY SEE IMPROVING CONDITIONS MOVE INTO N CT/RI AFTER MIDNIGHT SUNDAY NIGHT...PUSHING NE TOWARD DAYBREAK. MONDAY...MODERATE CONFIDENCE. MAY SEE PATCHY MVFR CONDITIONS ACROSS N MA EARLY MON MORNING. OTHERWISE...VFR. W-SW WINDS WITH GUSTS UP TO 20 KT. TUESDAY...MODERATE CONFIDENCE. VFR. LIGHT W-NW WINDS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY NIGHT/...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN SPECIFIC TIMING. TODAY...LOW PRESSURE MOVING NORTHEAST ACROSS THE WATERS. SHOWERS AND AREAS OF FOG START THE DAY. INCREASING NORTH WINDS WILL REACH 20 KNOTS ON OUR EASTERN WATERS AND COULD GET AS STRONG AS 25 KT. THE N-NE FETCH SHOULD BE ENOUGH TO BUILD SEAS ON THE EXPOSED EASTERN WATERS TO 5 FEET...POSSIBLY 6. A SMALL CRAFT ADVISORY REMAINS POSTED ON THE OUTER WATERS AND IN MASS BAY...PRIMARILY FOR SEAS...BUT WITH AN EYE TOWARD THE WINDS AS WELL. EXPANDED THE SMALL CRAFT ADVISORY INTO CAPE COD BAY FOR A TIME AS WELL. TONIGHT...MODERATE CONFIDENCE. DIMINISHING NORTH TO NORTHWEST WINDS WITH SEAS SUBSIDING AFTER MIDNIGHT. OUTLOOK /SATURDAY THROUGH TUESDAY/... SATURDAY...MODERATE TO HIGH CONFIDENCE. LIGHT NW WINDS BECOME SE DURING THE AFTERNOON AND EVENING. WIND GUSTS PICK UP TO AROUND 20 KT WHICH MAY CAUSE SEAS TO BUILD UP TO AROUND 5 FT ON THE SOUTHERN OUTER WATERS AROUND OR AFTER MIDNIGHT. SUNDAY AND MONDAY...MODERATE CONFIDENCE. SE WINDS BECOME SW AS LOW PRES MOVES W OF THE WATERS SUNDAY...THEN SHIFT TO W SUNDAY NIGHT. GUSTS UP TO 20 KT ON THE 4-6 FT ON THE OUTER WATERS INTO MONDAY...THEN WILL SUBSIDE DURING MON NIGHT. TUESDAY...MODERATE CONFIDENCE. EXPECT WINDS AND SEAS BELOW SMALL CRAFT CRITERIA. LIGHT W WINDS. && .HYDROLOGY... 455 AM UPDATE... LATEST RADAR TRENDS SHOWING SHOWERS BECOMING LESS WIDESPREAD FROM SOUTHWEST TO NORTHEAST THIS MORNING. HEAVIEST RAINFALL IS EXPECTED TO BE OVER THE COASTAL WATERS LATER THIS MORNING AS A LOW PRESSURE MOVES BY. NOT MUCH INSTABILITY LEFT ACROSS SOUTHERN NEW ENGLAND THIS MORNING...REDUCING THE POTENTIAL FOR THUNDERSTORMS. PRECIPITABLE WATER REMAIN HIGH. THE HEAVIEST RAINFALL RATES WERE UP TO ONE INCH PER HOUR...WITH MOST LOCATIONS LESS THAN ONE QUARTER INCH PER HOUR. AXIS OF HEAVIEST RAINFALL WAS MOVING OFFSHORE ALREADY THIS MORNING...SO THE FLASH FLOOD WATCH WAS CANCELED. ANY LINGERING SHOWERS THIS MORNING COULD STILL PRODUCE NUISANCE FLOODING OF POOR-DRAINAGE AND URBAN AREAS...MAINLY ACROSS THE CAPE AND ISLANDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 7 PM EDT THIS EVENING FOR ANZ231. SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ250-254. SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ251. SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM EDT SATURDAY FOR ANZ255-256. && $$ SYNOPSIS...BELK/EVT NEAR TERM...BELK SHORT TERM...BELK LONG TERM...EVT AVIATION...BELK/EVT MARINE...BELK/EVT HYDROLOGY...BELK
AREA FORECAST DISCUSSION
NWS TAUNTON MA
309 AM EDT FRI SEP 11 2015 .SYNOPSIS... A FRONT WILL PUSH NORTH OVERNIGHT AND PROVIDE A FOCUS FOR LOCALLY HEAVY DOWNPOURS OVERNIGHT. LOW PRESSURE FROM THE MID-ATLANTIC WILL MOVE NORTHEAST ALONG THE FRONT PAST OUR AREA FRIDAY MORNING PULLING IT OUT TO SEA FOLLOWED BY WEAK HIGH PRESSURE THAT BRINGS A LULL IN THE WEATHER SATURDAY. WET-WEATHER RETURNS FOR SUNDAY BUT NOT A WASH- OUT. TURNING DRY AND WARMER INTO NEXT WEEK. POSSIBLE RECORD BREAKING HEAT INTO MID- TO LATE-SEPTEMBER AS ABOVE-AVERAGE TEMPS ARE FORECAST. && .NEAR TERM /THROUGH TODAY/... 300 PM UPDATE... CANCELED THE FLASH FLOOD WATCH ACROSS NORTHERN CT AND WESTERN MA. WHILE STILL RAINING ACROSS THESE AREAS...THE INTENSITY IS JUST NOT THERE WHERE ANYTHING BEYOND NUISANCE POOR-DRAINAGE FLOODING WILL BE A CONCERN THROUGH DAYBREAK. AXIS OF HEAVIEST RAINFALL WILL BE ACROSS THE CAPE AND ISLANDS THIS MORNING. GREATEST SYNOPTIC LIFT WILL BE MAINLY EAST OF SOUTHERN NEW ENGLAND BETWEEN 6-10 AM THIS MORNING. MOISTURE WILL TAKE A LITTLE WHILE LONGER TO DIMINISH...BUT SHOULD DO SO LATER TODAY. OF ALL THE GUIDANCE...THOUGHT THE 11/05Z HRRR BEST CAPTURED THE TIMING...AND MATCHED UP BEST WITH OBSERVED RADAR TRENDS. THAT WAS THE BASIS FOR THE RAINFALL THIS MORNING. LATEST SURFACE OBSERVATIONS HAVE AT MOST 0.50-1.00 INCH/HOUR RAINFALL IN THE HEAVIEST SHOWERS...WITH MOST SITES REPORTING LESS THAN 0.25 INCH/HOUR RATES. WILL LIKELY BE ABLE TO CANCEL THE REMAINING FLASH FLOOD WATCH PRIOR TO ITS 6 AM EXPIRATION TIME. WILL EVALUATE THAT CLOSE TO THE OFFICIAL FORECAST TIME. STILL PLENTY OF CLOUDS TODAY...SO FORECASTING SEASONABLE TEMPERATURES. && .SHORT TERM /TONIGHT/... LOW PRESSURE MOVES FARTHER FROM OUR REGION. STILL DEALING WITH A MID LEVEL TROUGH...WHICH WILL STEER A SHORTWAVE OUR WAY LATE. THE BIG QUESTION IS HOW MUCH MOISTURE TO WORK WITH. RIGHT NOW... THINKING THERE WILL BE ENOUGH FOR SOME CLOUDS...BUT NOT FOR RAINFALL. KEEPING THE FORECAST FOR TONIGHT DRY. && .LONG TERM /SATURDAY THROUGH THURSDAY/... */ HIGHLIGHTS... - KEEPING IT DRY ON SATURDAY - WET WEATHER FOR SUNDAY BUT NOT LOOKING LIKE A WASHOUT EVERYWHERE - HEAVY RAIN THOUGH MAY IMPACT SE NEW ENGLAND ...HIGH TERRAIN - DRY AND WARM INTO NEXT WEEK ...POSSIBLE RECORD BREAKING HEAT */ DISCUSSION... KEEPING WITH AN ENSEMBLE APPROACH. H5 DEEP-TROUGH CLOSED LOW SWEEPS THROUGH THE OHIO-RIVER VALLEY SATURDAY AHEAD OF WHICH THERE IS RIDGE- AMPLIFICATION KEEPING US MOSTLY DRY WITH LIKELY SOME MID-HIGH LEVEL CLOUDS ACROSS THE REGION. LIFTING E SUNDAY DIFFLUENCE PROCEEDS ABOVE LOW-MID LEVEL LIFT / CONVERGENCE BUT CONVINCED S NEW ENGLAND IS IN AN AREA OF LESS FAVORABLE DEVELOPMENT. TWO AREAS OF INTEREST: THE CYCLONIC TROWALING ROUND THE CLOSED LOW BACK INTO THE E GREAT LAKES WHERE DEFORMATION PROCEEDS...AND SE NEW ENGLAND AND POINTS OFFSHORE WITHIN THE ANTI-CYCLONIC BRANCH OF THE WARM CONVEYOR BELT WHERE HIGH THETA-E VALUES RESIDE BENEATH DIFFLUENCE AND ENHANCED ASCENT WITH CONVERGENCE ALONG A STRONG H925-7 JET. S NEW ENGLAND BELOW THE RIGHT- FRONT-QUADRANT OF THE UPPER-LEVEL-JET AND IN THE CROSS-HAIRS OF A MID-LEVEL DRY-PUNCH WRAPPING INTO THE OCCLUDING SYSTEM PER ENSEMBLE MEANS LOOKS TO RESULT IN LITTLE OUTCOME OVER THE AREA. IN OTHER WORDS...NOT APPEARING TO BE A WASHOUT ON SUNDAY. CAN NOT RULE OUT HIGHER AMOUNTS OVER THE HIGHER TERRAIN. WITH ENSEMBLES LIFTING THE TROWAL N OF THE REGION SUNDAY NIGHT INTO MONDAY...LESS CONFIDENCE OF OUTCOMES ON MONDAY BENEATH THE COLD POOL AS THE TROUGH MAY MOVE THRU PRIOR TO BOUNDARY-LAYER DESTABILIZATION. PERHAPS SOME ACTIVITY UP AGAINST THE W-SLOPES OF HIGHER TERRAIN N OF OUR AREA WITH W-WIND CONVERGENCE. FOR THE REMAINDER OF THE WEEK...CONSISTENT SIGNALS OF RIDGING. THINK HEAT AND HUMIDITY BUILD BACK INTO THE REGION. AGREE WITH THE CLIMATE PREDICTION CENTER WITH ABOVE-AVERAGE TEMPERATURES. ENSEMBLES SIGNAL ANOMALOUS H85 TEMPERATURES ACROSS THE REGION. THINKING THAT WE COULD BREAK SOME RECORD HIGH TEMPERATURES INTO MID- TO LATE-SEPTEMBER. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH TONIGHT/... THROUGH 12Z...MODERATE CONFIDENCE. CONFIDENT MVFR-VLIFR MIX WITH CIGS. LOWER CONFIDENCE WITH VSBYS BUT EXPECT IFR WITH RA/+RA. FOG ALONG WITH LIFR-VLIFR CIGS LIKELY AN ISSUE FOR S/SE-COASTAL TERMINALS. GREATER TSRA RISK WILL BE OVER THE COASTAL WATERS. TODAY...MODERATE CONFIDENCE. IMPROVEMENT BEGINNING DURING THIS MORNING TOWARDS VFR. NE WINDS INCREASING AND GUSTING TO 20 KTS ALONG THE COASTS. TONIGHT...HIGH CONFIDENCE. EXPECTING MVFR-LIFR FOG DEVELOPMENT ESPECIALLY OVER THE INTERIOR TOWARDS MORNING. TYPICALLY PRONE TERMINALS WITHIN SHELTERED VALLEYS LIKELY TO EXPERIENCE LIGHT WINDS OVERNIGHT LIKE THE CT RIVER VALLEY ESPECIALLY PRONE. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING ISSUES. HIGH CONFIDENCE IN TRENDS. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING ISSUES. HIGH CONFIDENCE IN TRENDS. OUTLOOK /SATURDAY THROUGH TUESDAY/... SATURDAY...HIGH CONFIDENCE. VFR. WINDS VEERING E/SE. A MAINLY DRY FORECAST. SATURDAY NIGHT - SUNDAY NIGHT...MODERATE CONFIDENCE. MVFR-IFR MIX WITH E/SE-ONSHORE FLOW BACKING SW TOWARDS THE END OF THE FORECAST PERIOD. RAIN LIKELY ACROSS THE REGION. PATCHY FOG POSSIBLE. MAY ALSO CONTEND WITH SOME LLWS IMPACTS. MONDAY INTO TUESDAY...MODERATE CONFIDENCE. VFR. W/SW-WINDS WITH GUSTS UP TO 20 KTS. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY NIGHT/...HIGH CONFIDENCE IN TRENDS. MODERATE CONFIDENCE IN SPECIFIC TIMING. TODAY...LOW PRESSURE MOVING NORTHEAST ACROSS THE WATERS. SHOWERS AND AREAS OF FOG START THE DAY. INCREASING NORTH WINDS WILL REACH 20 KNOTS ON OUR EASTERN WATERS AND COULD GET AS STRONG AS 25 KT. THE N-NE FETCH SHOULD BE ENOUGH TO BUILD SEAS ON THE EXPOSED EASTERN WATERS TO 5 FEET...POSSIBLY 6. A SMALL CRAFT ADVISORY REMAINS POSTED ON THE OUTER WATERS AND IN MASS BAY...PRIMARILY FOR SEAS...BUT WITH AN EYE TOWARD THE WINDS AS WELL. TONIGHT...MODERATE CONFIDENCE. DIMINISHING NORTH TO NORTHWEST WINDS WITH SEAS SUBSIDING AFTER MIDNIGHT. OUTLOOK /SATURDAY THROUGH TUESDAY/... SATURDAY...MODERATE CONFIDENCE. A LULL IN THE WEATHER. WINDS BECOME LIGHT WHILE VEERING E/SE. SHOULD SEE SEAS SUBSIDE FOR THE PERIOD BELOW 5-FEET. SUNDAY...MODERATE CONFIDENCE. DEEPER AREA OF LOW PRESSURE TO THE W. WILL SEE AN ACCOMPANYING WARM FRONT LIFT N ACROSS THE WATERS BRINGING WITH IT RAIN ALONG WITH INCREASING E/SE-ONSHORE WINDS. GUSTS UP TO 20 KTS. WAVE HEIGHTS BUILDING IN EXCESS OF 5-FEET INITIALLY OVER THE S WATERS EXPANDING TO THE E/SE WATERS LATE IN THE PERIOD. MONDAY...MODERATE CONFIDENCE. IMPROVING. WINDS BACK OUT OF THE W/SW AND REMAIN ROBUST WITH A STRONG AREA OF LOW PRESSURE SITUATED WELL TO THE W ACROSS THE INTERIOR. ANOTHER DAY OF GUSTS UP TO 20 KTS WHILE SEAS REMAIN AT OR IN EXCESS OF 5-FEET ON THE WATERS. && .HYDROLOGY... 3 AM UPDATE... LATEST RADAR TRENDS SHOWING SHOWERS BECOMING LESS WIDESPREAD FROM SOUTHWEST TO NORTHEAST THIS MORNING. HEAVIEST RAINFALL IS EXPECTED TO BE OVER THE COASTAL WATERS LATER THIS MORNING AS A LOW PRESSURE MOVES BY. NOT MUCH INSTABILITY LEFT ACROSS SOUTHERN NEW ENGLAND THIS MORNING...REDUCING THE POTENTIAL FOR THUNDERSTORMS. PRECIPITABLE WATER REMAIN HIGH. THE HEAVIEST RAINFALL RATES WERE UP TO ONE INCH PER HOUR...WITH MOST LOCATIONS LESS THAN ONE QUARTER INCH PER HOUR. WE MAY BE ABLE TO CANCEL THE REMAINING FLASH FLOOD WATCH EARLY...DESPITE THE CONTINUING RAINFALL THIS MORNING. WE WILL CONTINUE TO EVALUATE OVER THE NEXT HOUR. AT THIS TIME...IT APPEARS THE GREATEST RISK WILL BE FOR NUISANCE FLOODING OF POOR- DRAINAGE AND URBAN AREAS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...FLASH FLOOD WATCH UNTIL 6 AM EDT EARLY THIS MORNING FOR MAZ004>007-012>022-026. RI...FLASH FLOOD WATCH UNTIL 6 AM EDT EARLY THIS MORNING FOR RIZ001>007. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ250-254. SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ251. SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM EDT SATURDAY FOR ANZ255-256. && $$ SYNOPSIS...BELK/SIPPRELL NEAR TERM...BELK SHORT TERM...BELK LONG TERM...SIPPRELL AVIATION...BELK/SIPPRELL MARINE...BELK/SIPPRELL HYDROLOGY...BELK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
335 AM CDT FRI SEP 11 2015 .SHORT TERM...(TODAY) ISSUED AT 334 AM CDT FRI SEP 11 2015 A weakening MCS over Missouri continues to move east toward southern IL early this morning while an upper level shortwave approaches central IL via Iowa. A cold front at the surface has pushed southward to around I-64 however convergence aloft due to the interaction of the above features is triggering numerous thunderstorms across central IL. Modest instability generally under 500 J/kg according to SPC mesoscale analysis has kept most of the storms fairly weak to moderate...however some heavy rainfall corridors have developed due to orientation of repeated thunderstorms. This system will gradually move eastward through the early afternoon with thunderstorms tapering off from west to east. Meanwhile...much colder air aloft moving into the region from the north will bring lake effect rain showers off of Lake Michigan...some of these could trigger a some more showers and isolated thunder out to Vermilion and Champaign counties and this is hinted at by several models. Highs today will only reach the lower 70s given the cooler post frontal air mass which has moved in. && .LONG TERM...(TONIGHT THROUGH Thursday) ISSUED AT 334 AM CDT FRI SEP 11 2015 Much cooler temperatures expected this weekend due to strong upper level trof/low pressure digging southward from the western great lakes into IL/IN and ohio river valley through Saturday. Have a slight chance of showers into mid evening from Bloomington to Champaign to Paris northeast. Then isolated chances of showers returns on Sat with partly to mostly cloudy skies and breezy north winds, especially east of the IL river with best chances over east central IL. Lows tonight in the upper 40s/lower 50s with mildest readings south of I-72. Cool highs Saturday mostly in the mid 60s. Strong upper level trof pushes east of IL Sat night and Sunday while 1025 mb Canadian high pressure over ND settles into the mid MS river valley Sunday morning. Clouds and wind decrease Sat night and sets us up for cooler night with lows 43-48F. A pleasant day expected Sunday with ample sunshine and highs in the lower 70s, expect a few upper 60s in eastern IL. Not quite as cool Sunday night as high pressure slips se of IL toward the central Appalachians. Lows around 50F in eastern IL and mid 50s near the MS river valley of west central IL. 00Z medium and extended range models show upper level high pressure ridge building across the eastern U.S. Monday through Wed and providing dry and warmer weather to IL. Highs Monday in the mid to upper 70s with west central IL near 80F, climb into the lower 80s Tue and mid 80s Wed and back to the lower 80s Thu. A cold front to push into the southern Great Lakes by sunset Thursday and to bring an increasing chance of showers and thunderstorms Thu/Fri. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Friday NIGHT) ISSUED AT 1100 PM CDT THU SEP 10 2015 Forecast a bit more complicated late tonight that what we saw late this afternoon as a period of clear skies across the northeast half of our forecast area has led to some patchy fog to the north of the TAF sites. The last few runs of the HRRR model has taken and run with the idea of low stratu and vsbys advecting south overnight with MVFR and IFR cigs and vsbys, but that is the only solution I have seen to be so aggressive with the lowering of the cigs and vsbys. Forecast soundings off the operational models not showing much if any low cigs across the area late tonight into Friday morning as an upper level wave interacts with the cold front passing across our area late this evening bringing thicker cloud cover back into the forecast area and a return to showers and isold tsra. The rain itself may be enough to temporarily lower cigs at times tomorrow morning before a drying trend works in during the afternoon. Look for light east to northeast winds to turn more northerly on Friday and increase to 12 to 17 kts by afternoon with a few gusts at or above 20 kts during the afternoon, before we see a diminishing trend during the evening. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Onton LONG TERM...07 AVIATION...Smith
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1250 AM EDT FRI SEP 11 2015 ...UPDATED AVIATION DISCUSSION... ...FORECAST UPDATE... ISSUED AT 955 PM EDT THU SEP 10 2015 THE DENSE FOG ADVISORY FOR PORTIONS OF EAST CENTRAL KY STILL LOOKS GOOD ACCORDING TO THE LATEST OBS, NAM, AND HRRR GUIDANCE. A GOOD BUBBLE OF LOW LEVEL MOISTURE COMBINED WITH SUBSIDENCE FROM A SFC HIGH OVER THAT REGION CONTINUE TO LOOK FAVORABLE FOR DENSE FOG FORMATION. IN FACT SOME LIGHT FOG HAS ALREADY STARTED TO FORM NEAR LONDON, KY. LIGHT PATCHY FOG IS EXPECTED ELSEWHERE WITH LOW TEMPS RANGING FROM THE UPPER 50S TO LOWER 60S. .SHORT TERM (NOW THROUGH SUNDAY)... ISSUED AT 432 PM EDT THU SEP 10 2015 POPCORN SHOWERS OVER THE FAR SOUTHEAST WILL FALL APART AS THE SUN LOWERS IN THE SKY THIS AFTERNOON, FOLLOWED BY DISSIPATION OF THE CU FIELD AS THE SUN SETS. THIS WILL LEAD TO CLEAR SKIES AND NEARLY CALM WINDS TONIGHT, SUGGESTING THE POSSIBILITY OF FOG. SOME DRY LOW LEVEL AIR LOOKS TO SNEAK IN FROM THE NORTH, BUT SOUTHEASTERN AREAS OF THE CWA WILL NOT BENEFIT FROM THAT AIR AND ALSO SAW QUITE A BIT OF RAIN EARLIER TODAY TO ADD TO GROUND MOISTURE. AFTER CONFERRING WITH JKL, HAVE DECIDED TO GO AHEAD AND PUT OUT A DENSE FOG ADVISORY THIS AFTERNOON FOR THE FAR EAST AND SOUTHEAST PARTS OF THE CWA...GENERALLY FROM THE LAKE CUMBERLAND REGION TO SOUTH/EAST OF LEXINGTON. FOG WILL BE POSSIBLE ELSEWHERE AS WELL, BUT SHOULD BE MOSTLY CONFINED TO SPOTS THAT FOG IN EASILY AND SHOULDN`T BE QUITE AS WIDESPREAD AS IN THE ADVISORY COUNTIES. TOMORROW AN UNSEASONABLE UPPER TROF WILL COME IN FROM THE NORTHWEST AND SPARK SHOWERS AND THUNDERSTORMS, ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS. WE MAY GET SOME GUSTY SHOWERS AND PEA SIZED HAIL IN THE STRONGER SHOWERS...ESPECIALLY IN THE SOUTHEAST WHERE LAPSE RATES WILL BE A LITTLE STEEPER. WE`RE ALREADY SEEING THIS TO OUR WEST WITH ACTIVITY IN MISSOURI AND ILLINOIS TODAY. HIGH TEMPERATURES WILL BE A FEW DEGREES EITHER SIDE OF 80. RAIN CHANCES WILL DECREASE AFTER MIDNIGHT TOMORROW NIGHT AS TEMPERATURES FALL INTO THE 50S. .LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)... ISSUED AT 245 PM EDT THU SEP 10 2015 THE MAIN FORECAST CONCERN IN THE LONG TERM IS THE UNSEASONABLY COOL CONDITIONS THIS WEEKEND. A VERY ANOMALOUSLY DEEP SHORTWAVE TROUGH WILL DIVE ACROSS THE EASTERN U.S. SATURDAY INTO SUNDAY. ANOMALIES WITH THIS FEATURE ARE ROUGHLY 4 STANDARD DEVIATIONS BELOW NORMAL FOR HEIGHTS AND TEMPS. WITHIN THE DEEP CYCLONIC FLOW AND CRASHING TEMPERATURES ALOFT... THERE COULD BE SOME INSTABILITY SHOWERS OR PERHAPS A RUMBLE OF THUNDER DURING THE DAY SATURDAY. THE MAIN NEGATIVE FACTOR TO MORE WIDESPREAD SHOWERS IS LIMITED AND SHALLOW MOISTURE...AS PRECIPITABLE WATER VALUES ARE ONLY AROUND 0.75 INCH DURING THE DAY. MODEL SOUNDINGS FROM THE NAM AND GFS DO SHOW ABOUT 100 MB OF HIGHER RH BETWEEN 700 AND 800 MB. THINKING THAT WE WILL SEE A GOOD AMOUNT OF STRATO CU CLOUDS FORM WITH THE POTENTIAL FOR DIURNAL SCATTERED SHOWERS AT TIMES. WILL CONTINUE TO ADVERTISE 20-30 PERCENT POPS DURING THE AFTERNOON. THE MORE NOTICEABLE IMPACT WILL BE TEMPERATURES WITH HIGHS STRUGGLING TO REACH 70 IN MOST PLACES ALONG WITH NORTH/NORTHWEST BREEZES. THESE HIGHS WILL BE ABOUT 15 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR ON SATURDAY AND 10 TO 15 DEGREES BELOW NORMAL ON SUNDAY...AND A SOLID 20 TO 25 DEGREES COLDER THAN JUST EARLIER THIS WEEK. RECORD LOWS AND COLD MAXIMUMS SATURDAY AND SUNDAY DO NOT APPEAR TO BE IN JEOPARDY AT ANY OF THE OFFICIAL SITES. SURFACE HIGH PRESSURE BUILDS INTO THE REGION SATURDAY NIGHT INTO SUNDAY MORNING. LIGHT WINDS AND CLEARING SKIES...ESPECIALLY WEST OF I-65...SHOULD LEAD TO LOWS REACHING THE MID 40S TO NEAR 50 FOR SOUTHERN INDIANA AND CENTRAL KENTUCKY. ON SUNDAY...THE UPPER TROUGH AND SURFACE HIGH ADVANCE EASTWARD THOUGH WE WILL STILL HAVE COOLER TEMPERATURES ALOFT. HIGHS AGAIN IN THE UPPER 60S/NEAR 70. FOR NEXT WEEK...HEIGHTS AND TEMPERATURES ALOFT BUILD AS RELATIVELY WEAK WEST TO SOUTHWEST FLOW DEVELOPS. LOW-LEVEL WINDS WILL BECOME SOUTHEAST TO SOUTH IN RESPONSE...RESULTING IN A GRADUAL MODERATION IN TEMPERATURES. NO MAJOR STORM SYSTEMS ARE ON THE HORIZON THROUGH AT LEAST MID NEXT WEEK...BUT EVENTUALLY RETURN SOUTHERLY LOW-LEVEL FLOW AND A WEAK DISTURBANCE OR TWO ALOFT COULD BRING WIDELY SCATTERED CONVECTION TO PARTS OF THE AREA LATE NEXT WEEK. && .AVIATION (00Z TAF UPDATE)... ISSUED AT 1230 AM EDT FRI SEP 11 2015 MAIN CHALLENGE OVERNIGHT IS FOG POTENTIAL, ESPECIALLY IN BWG AND LEX. DRIER AIR HAS STARTED TO FILTER IN AND WE HAVE 5F TEMP/DEWPOINT SPREADS, SO WILL NOT HIT IT THAT HARD. WILL CARRY A FEW HRS OF MVFR VIS AROUND DAYBREAK, WHILE HEAT ISLAND EFFECTS KEEP SDF UNRESTRICTED. OTHER CONCERN IS LATE AFTERNOON/EVENING SHOWER/T-STORM POTENTIAL AS THE NEXT UPPER IMPULSE SWINGS THROUGH. NOT ENOUGH CONFIDENCE IN THE TIMING OR IMPACTS TO INCLUDE ANY RESTRICTIONS AT THIS TIME, HOWEVER WE WILL CARRY VCTS/CB FROM 20-21Z WELL INTO THE EVENING. PREVAILING VFR CONDITIONS FOR NOW, AT LEAST UNTIL WE CAN BETTER NAIL DOWN THE TIMING. WNW WINDS IN THE AFTERNOON WILL COME AROUND TO NNW LATER IN THE EVENING, BUT LESS THAN 10 KT OUTSIDE OF ANY STORMS. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...DENSE FOG ADVISORY UNTIL 9 AM EDT /8 AM CDT/ THIS MORNING FOR KYZ056-057-066-067-077-078-081-082. IN...NONE. && $$ UPDATE.........AMS SHORT TERM.....13 LONG TERM......TWF AVIATION.......RAS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
500 AM CDT FRI SEP 11 2015 .DISCUSSION... OUR SURFACE WINDS ARE LIGHT S/SW OR CALM WITH MUGGY UPPER 60S OR LOWER 70 DEW POINTS FOR MOST OF THE FOUR STATE AREA. SOME LOWER 60S LINGER NORTH OF A STATIONARY FRONT WITH LOW TO MID 60S. AIR TEMPERATURES ARE LIKE WISE...COOLER NORTH OF THE OLD STATIONARY FRONTAL BOUNDARY WITH LOW TO MID 70S ALONG AND SOUTH OF I-20. SKIES ARE FAIR TO PARTLY CLOUDY WITH SOME PATCHY FOG MAINLY SOUTH WHERE SOILS ARE FRESHLY DAMP. THE KSHV 88D IS QUIET...BUT THERE IS SOME DRIZZLE WITH THE FOG OVER DEEP EAST TEXAS AND THUNDERSTORMS ON APPROACH FROM THE NORTH. HOWEVER...GUST FRONTS ARE SEEN ON RADAR MOSAICS MOVING OUT AHEAD OF THE MAIN PRECIP AREA AND WILL CONTINUE TO DIMINISH BASED ON GUIDANCE. THE HRRR SHOWS SOME NEW DEVELOPMENT BY MID MORNING AND WITH HEATING ALL AFTERNOON. THE NAM EVEN GOES WELL INTO THE EVENING HOURS AS THE FRONT IS STILL FAR TO THE NORTH. THE OUTFLOW BOUNDARY COMING WILL BE THE MAIN...BUT NOT THE ONLY FOCUS WITH SOME LOW LEVEL VARIATIONS AND GOOD HEATING STILL LIKELY. THE CURRENT SURFACE FLOW IS VERY SHALLOW AS OUR VAD PROFILER IS SHOWING NORTHERLY FLOW AT ALL LEVELS FROM 1KFT ON UP. THE MOISTURE WILL BE SLOW TO SCOUR UNTIL THE FRONT ARRIVES LATE WITH EVEN HRRR SHOWING SOME WIDELY SCATTERED ACTIVITY ALONG AND SOUTH OF I-30 INTO THE EARLY EVENING. SO CHECK THE RADAR FOR ALL OUTDOOR PLANS INTO THE EVENING. THE GFS SHOWS LIKEWISE WITH SOME DECENT QPF STILL AT THE MIDNIGHT HOUR. OVERALL...QPF IS LIGHT FROM WPC AND ACTIVITY SHOULD BE BRIEF AND PERHAPS MORE SHOWERY THAN THUNDERY.OUR LAST SOUNDING WAS DRY ALOFT...BUT WITH MID AND UPPER LEVEL MOISTURE ON APPROACH POOLING AHEAD OF THE FRONT...THE UPPER LEVELS SHOULD BE THINNING BACK TO DRIER SOONER THAN THE REMAINING LOW LEVEL MOISTURE ALONG THE OLD FRONT. THE SPC HAS A GENERAL LINE FAR TO OUR NORTH RIGHT AHEAD OF THE NEW COLD FRONT SEEN WELL WITH 50 DEW POINTS FROM KN INTO N MO. THIS BOUNDARY WILL MAKE FOR A LATE SEPTEMBER FALL FEEL FOR THE WEEKEND WITH A NICE CHANGE OF SEASON EARLY. HOWEVER...WE COULD USE ANY AND ALL RAINFALL AS THIS FRONTAL PASSAGE WILL BRING BACK A DRY PATTERN ALONG WITH THE COOLER AIR INTO EARLY NEXT WEEK. BY THEN...THE GULF OPENS UP A BIT WITH SOME MOISTURE AND GOOD LATE SUMMER HEATING TO RETURN BY MID AND THROUGH LATE WEEK. /24/ && .PRELIMINARY POINT TEMPS/POPS... SHV 94 68 84 57 / 30 50 10 0 MLU 92 66 82 53 / 20 60 10 0 DEQ 90 60 81 52 / 40 20 0 0 TXK 92 63 81 54 / 30 20 0 0 ELD 91 62 79 52 / 30 40 0 0 TYR 93 67 83 59 / 30 50 10 0 GGG 93 67 83 57 / 30 50 10 0 LFK 92 71 87 58 / 30 50 10 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 24
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1140 PM CDT THU SEP 10 2015 .UPDATE: Issued at 623 PM CDT Thu Sep 10 2015 Have increased PoPs across ern portions of the CWA where TSRA continue to drop swd into the region. Outflow boundaries will continue to make wwd extent of precip challenging, but believe bulk of precip will remain E of the Mississippi River. Storms shud weaken with sunset. Minimal svr threat continues. Remainder of forecast for tonight currently appears to be on track. && .SHORT TERM: (Through Late Tonight) Issued at 338 PM CDT Thu Sep 10 2015 Spotty convection will continue across most of the FA early this evening due to numerous outflow/surface boundaries migrating through mostly unstable airmass of MLCAPES 1000-2000 j/kg. However, still believe the primary "show" will be late this evening and overnight as primary shortwave energy digs into the region and begins to interact with southward sagging cold front/baroclinic zone. Last several runs of the HRRR continue to support idea that convection over NE will drop/develop across e KS and w MO during the early evening hours as UVV increases due to shortwave as well as increasing isentropic ascent, with the resultant elevated shower and embedded thunderstorm threat overspreading much of the CWA during the overnight hours. Have highest PoPs (~80%) over mid MO where lift and moisture advection should be maximized...this is a bit higher/bit further north than earlier forecast, but models are still indicating good divergence developing across northern MO in the RRQ of the back building upper level jet. PoPs then taper off to high chance over far northern and southern sections of the FA as precip should tend to "fade" a bit as it advects out of the primary zone of ascent. Truett .LONG TERM: (Friday through Next Thursday) Issued at 338 PM CDT Thu Sep 10 2015 Even though frontal boundary will be south of forecast area by 12z Friday, will see some lingering post frontal precipitation gradually tapering off from north to south, including some isolated thunderstorms. Otherwise, colder air to filter into the region and with plenty of cloud cover and rain, temperatures will only rise into the upper 60s to mid 70s. Dry and colder weather to prevail through the weekend. Could see a stray shower on Saturday as decent shortwave energy rotates around upper level trof that is anchored over the Great Lakes. For now have dry conditions, but will need to keep an eye on the models as we get closer to this time period. By Sunday night surface ridge will begin to move off to the southeast. This will allow southerly winds to return once again and temperatures moderate back into the 80s by Tuesday. Extended models hinting at another cold front moving through region beginning Wednesday night. Have low chance pops Wednesday night and Thursday. Byrd && .AVIATION: (For the 06z TAFs through 06z Friday Night) Issued at 1140 PM CDT Thu Sep 10 2015 Rain with imbedded TSRA has indeed developed over western MO and is in the process of working its way eastward: reaching UIN and COU by the beginning of the valid period and the STL metro sites by 08-09z. Some lower VSBYs possible but looks to brief and primarily on the front-end of this system. Also, due to cold front also moving thru near the initial onset and much of the rain on the cool side of the front, should see low-end MVFR CIGs form and prevail for several hours into the morning. Rain and low clouds to move out later Friday morning or midday, leaving behind VFR conditions and gusty N-NW winds in its wake. Specifics for KSTL: rain and thunder still on track to move in but pushed back slightly to 08z from 07z, otherwise no changes to previous 00z TAF: rain and possibly some thunder overnight and Friday morning with several hours of low MVFR CIGs, becoming VFR and dry by afternoon with gusty NW winds. Winds to diminish with clearing by Friday evening. TES && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1124 PM CDT THU SEP 10 2015 .UPDATE... ISSUED AT 613 PM CDT THU SEP 10 2015 JUST CANCELLED THE SEVERE THUNDERSTORM WATCH FOR HAYES...FRONTIER...CUSTER AND LINCOLN COUNTIES. THUNDERSTORMS HAVE MOVED SOUTH AND EAST OF THE AREA...WITH A FAIRLY STABLE BOUNDARY LAYER NOTED ACROSS SWRN AND PORTIONS OF CENTRAL NEBRASKA. SOME LIGHT RAIN SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE NERN CWA FOR THE NEXT 1 TO 2 HRS AND WILL BE UPDATING THE FORECAST WHEN THIS ACTIVITY CLEARS THE AREA. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 323 PM CDT THU SEP 10 2015 STRONG TO LOCALLY SEVERE THUNDERSTORMS ARE THE PRIMARY CONCERN GOING IN THE NEAR TERM...WITH THE MAIN THREAT AREA FOR SEVERE WEATHER MAINLY ACROSS OUR FAR SOUTHEASTERN ZONES. LARGE SCALE FORCING IN ASSOCIATION WITH NORTHERN PLAINS IMPULSE HAS ALREADY SPARKED OFF SHOWERS AND A FEW STRONG THUNDERSTORMS THIS AFTERNOON. DEVELOPMENT HAVE BEEN NOTICED ACROSS OUR NORTHERN ZONES WHERE THE ATMOSPHERE IS CHARACTERIZED AS WEAKLY UNSTABLE. A SECOND AREA OF DEVELOPMENT APPEARS TO BE ALONG A MID-LEVEL FRONT ACROSS SOUTHEASTERN CUSTER COUNTY WEST INTO THE SANDHILLS AND THE THIRD IS ACROSS FAR SOUTHWEST NEBRASKA /EAST OF MCK/. THIS DEVELOPMENT IS FOCUSING ALONG A DRY LINE. WILL NEED TO MONITOR OUR SOUTHEASTERN ZONES AS THEY LIE IN A FAVORABLE REGION FOR SUPERCELL DEVELOPMENT. MESOANALYSIS FROM ACROSS OUR SOUTHEASTERN ZONES REVEALS AMPLE INSTABILITY...WITH SBCAPES ESTIMATED AT 3500 J/KG WITH FAVORABLE INCREASING/VEERING WINDS ALOFT ACROSS MUCH OF FRONTIER COUNTY. THE SPC SIGNIFICANT HAIL PARAMETER INDICATES A BULLSEYE OF 3 ALONG THE LINCOLN/FRONTIER COUNTY LINE AND A 2 OVER MUCH OF OUR SOUTHEASTERN ZONES. THE SUPERCELL COMPOSITE GENERALLY FAVORS THE SAME AREA. LARGE HAIL IS THE PRIMARY CONCERN WHERE STORMS FORM ACROSS OUR SOUTHEASTERN ZONES. LATEST HRRR GUIDANCE IS PICKED UP ON THE SB CONVECTION ACROSS OUR FAR SOUTHEASTERN ZONES WELL IN PREVIOUS RUNS...BUT LARGELY IGNORED THE MID-LEVEL FRONT /ELEVATED CONVECTION OVER THE SANDHILLS EAST THROUGH CUSTER COUNTY/ UNTIL THE MOST RECENT RUN. THE MODEL HAS BEEN STEADY THOUGH SUGGESTING THE POTENTIAL SEVERE ACTIVITY SOUTHEAST OF THE FORECAST AREA SHORTLY AFTER 22Z. FOR THE NORTHERN SHOWERS AND WEAK STORMS...THE FORCING WILL QUICKLY SHIFT EAST THIS EVENING...WITH THE SHOWERS EXPECTED TO BE OVER BY MID-EVENING. POST FRONTAL CONDITIONS WILL PROVIDE FOR A DRY AND COOL DAY ACROSS THE CENTRAL PLAINS ON FRIDAY. HIGHS ARE FORECAST TO WARM INTO THE 60S TO LOWER 70S ACROSS THE FORECAST AREA. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 323 PM CDT THU SEP 10 2015 FOR FRIDAY NIGHT AND SATURDAY...AN AMPLIFIED NWRLY FLOW ALOFT WITH A RETURN OF SOUTHERLY WINDS WITH HIGHS WARMING TO THE LOWER 80S ACROSS THE WEST WHILE THE EAST REMAINS IN THE LOWER TO MID 70S. ON SUNDAY...A BROAD TROUGH WILL EXTEND WEST TO EAST ACROSS CANADA WITH FAIRLY ZONAL FLOW ACROSS THE NRN CONUS. THIS WILL BRING A THERMAL RIDGE EASTWARD INTO THE PLAINS AS H85 TEMPS IN WRN NEBR REACH 25 TO 30C. HIGHS WERE NUDGED UPWARD TO NEAR 90 WEST. FOR MONDAY THROUGH THURSDAY...ABOVE NORMAL TEMPERATURES. UPPER FLOW WILL BECOME SOUTHWESTERLY ALOFT MONDAY AND TUESDAY AS AN UPPER TROUGH DIGS INTO THE NWRN CONUS. THIS WILL ACT TO EXPAND THE THERMAL RIDGE EASTWARD ACROSS THE CENTRAL PLAINS. HIGHS AGAIN NUDGED UPWARD TO THE UPPER 8OS TO AROUND 90 MOST AREAS THESE HIGHS WILL BE 10 TO 15 DEGREES ABOVE NORMAL. A COLD FRONT TUESDAY NIGHT TO BRING A SLIGHT CHC FOR SHOWERS AND THUNDERSTORMS. EXTENDED PROCEDURE KEEPS WEDNESDAY DRY EXCEPT A SLIGHT CHANCE IN THE NORTHEASTERN AREAS. FUTURE MODEL RUNS MAY SHOW BETTER SUPPORT FOR WEDNESDAY AND WEDNESDAY NIGHT. BEHIND THE FRONT....HIGHS COOL BACK SOME TO THE UPPER 70S NORTH AND LOWER 80S NORTH FOR WEDNESDAY AND THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1125 PM CDT THU SEP 10 2015 FOR THE KLBF TERMINAL...EXPECT SCATTERED CLOUDS AROUND 20000 FT AGL OVERNIGHT WITH A THREAT FOR PATCHY FOG FROM 10Z TO 14Z FRIDAY MORNING. VISBYS MAY DROP AS LOW AS 4SM. ON FRIDAY...MID CLOUDS WILL THICKEN BY AFTERNOON WITH CIGS AROUND 10000 FT AGL EXPECTED. FOR THE KVTN TERMINAL...EXPECT SCATTERED TO BROKEN CIGS AROUND 10000 FT AGL OVER THE NEXT 24 HOURS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CLB SHORT TERM...JACOBS LONG TERM...ROBERG AVIATION...CLB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
421 AM EDT FRI SEP 11 2015 .SYNOPSIS... A COLD FRONT OVER THE CENTRAL GREAT LAKES WILL MOVE EAST ACROSS THE AREA TODAY. A STRONG UPPER AIR DISTURBANCE WILL DROP ACROSS THE GREAT LAKES THIS WEEKEND. HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UNSETTLED WEATHER IS EXPECTED TO DEVELOP ACROSS THE REGION TODAY AS A COLD FRONT CURRENTLY LOCATED FROM NORTHERN LOWER MICHIGAN TO ILLINOIS MOVES ACROSS THE REGION THIS AFTERNOON. SHOWERS ARE EXPECTED TO DEVELOP OVER NORTHWEST OHIO LATE THIS MORNING AND PROGRESS TO NORTHEAST OHIO BY THIS EVENING. MOST OF THE SHOWERS ARE EXPECTED TO BE POST FRONTAL. HAVE USED THE HRRR FOR TIMING OF THE PRECIPITATION. LATE MORNING SHOWERS WILL LIMIT MAX TEMPERATURES NEAR TOL WHILE EASTERN COUNTIES WILL BE RAINFREE MOST OF THE DAY WHICH WILL ALLOW TEMPERATURES TO CLIMB INTO THE MID 70S. A MODEST AMOUNT OF INSTABILITY IS EXPECTED WITH CAPE EXPECTED TO INCREASE TO AROUND 500 J/KG. WILL INITIALLY MENTION SHOWERS TODAY AND THEN ADD THUNDERSTORMS FOR THE AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SOMEWHAT SHOWERY FOR THE FIRST HALF OF THE WEEKEND AND THEN GRADUALLY IMPROVEMENT SUNDAY AND ESPECIALLY ON MONDAY. LITTLE CHANGE IN EXPECTATION FOR THE WEEKEND WEATHER AS A POTENT SHORT WAVE DISTURBANCES AMPLIFIES THE LONG WAVE TROUGH OVER THE REGION SATURDAY. THE TROUGH WILL THEN SLOWLY LIFT NORTHEAST AWAY FROM THE REGION SUNDAY AND MONDAY. THE COLD AIR ALOFT WITH THE APPROACHING TROUGH IN COMBINATION WITH RATHER WARM LAKE ERIE NEAR 24C WILL CREATE AN UNSTABLE BOUNDARY LAYER OVER AND DOWNWIND OF THE LAKE. CONSEQUENTLY, INSTABILITY SHOWERS WITH PERHAPS SOME THUNDER ARE LIKELY ESPECIALLY SATURDAY AND SATURDAY NIGHT EAST OF KCLE. CAPE OVER LAKE ERIE MAY BE AS HIGH AS 500-1000 J/KG WHICH COULD PRODUCE MODERATE TO BRIEFLY HEAVY SHOWERS. THE DOWNSCALED NAM DEPICTS CONVECTIVE DEVELOPMENT OVER AND SOUTHEAST OF THE LAKE OVER THE EASTERN HALF OF THE FORECAST AREA MAINLY ON SATURDAY AND THIS SEEMS REASONABLE. AS THE UPPER SYSTEM BEGINS TO LIFT AWAY AND INSTABILITY AND MOISTURE DECREASE ON SUNDAY AND SUNDAY NIGHT, SHOWERS WILL BECOME MORE SCATTERED AND CONFINED MAINLY TO THE SNOWBELT COUNTIES EAST OF KCLE. HAVE REDUCED POP BELOW MENTIONABLE VALUES ON MONDAY GIVEN THE EXPECTED RIDGING AND DRY LOW LEVEL WESTERLY FLOW OVER THE REGION ALONG WITH THE WARMING STABILIZING FLOW. THE WEEKEND WILL BE RATHER COOL AND ABOUT 10 DEGREES BELOW NORMAL AND BE MAINLY IN THE MID TO UPPER 60S. IF PRECIPITATION IS MORE CONSTANT ALONG WITH CLOUD COVER, READINGS MAY ON REACH 60 IN THE HIGHER TERRAIN OF GEAUGA COUNTY AND INLAND NORTHWEST PENNSYLVANIA. MODERATING CONDITIONS ARE EXPECTED MONDAY. && .LONG TERM /TUESDAY THROUGH THURSDAY/... THE FORECAST FOR TUE THRU THU STILL LOOKS IN LINE WITH HIGH PRESSURE...DRY WX AND WARMING TEMPS. THE MODELS SHOW MOISTURE WITH A WEAK S/W SPREADING BACK INTO THE AREA THU INTO THU NIGHT SO WILL CONTINUE TO SHOW INCREASING CHC POPS WEST TO EAST FOR THEN. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SOME PATCHY MVFR FOG SHOULD DEVELOP AROUND CAK AND YNG TOWARD DAYBREAK...OTHERWISE VFR WILL PREVAIL INTO THE DAYLIGHT HOURS. RAIN AND EVENTUAL MVFR CONDITIONS SHOULD RAPIDLY DEVELOP WEST TO EAST FROM 15Z AROUND TOL AND FDY TO 19 TO 21Z FOR YNG AND ERI. MOST OF THE RAIN SHOULD END IN THE WEST AROUND 00Z AND CIGS MAY IMPROVE FOR A WHILE BEFORE LOWERING AGAIN LATER IN THE NIGHT. LIGHT WINDS WILL BECOME NORTH FROM 10 TO 15 KNOTS LATER TODAY INTO TONIGHT. OUTLOOK...NON VFR CONTINUING THROUGH THE WEEKEND...ESPECIALLY FOR NE OH AND NW PA. && .MARINE... NORTH WINDS BEHIND A COLD FRONT WILL INCREASE THIS AFTERNOON AND EVENING WITH SCA CONDITIONS DEVELOPING BY THE END OF THE DAY. WINDS ARE EXPECTED TO DECREASE SOME ON SAT BUT MAY NOT BE ENOUGH TO SEE WAVES FALL BELOW 4 FEET SO THE SCA MAY NEED TO CONTINUE INTO SUN. IF THE HIGH MOVING UP THE OH VALLEY SUN AND SUN NIGHT STAYS FAR ENOUGH TO THE SOUTH WINDS WILL BACK TO SW SUN NIGHT INTO MON BUT COULD STAY JUST STRONG ENOUGH FOR MARGINAL SCA WAVES TO HANG ON FOR THE EAST PART OF THE LAKE...BUT FOR NOW WILL MAINTAIN CONTINUITY WITH SUB SCA CONDITIONS. WINDS CONTINUE TO BACK TO SOUTH AND LIGHTEN MON NIGHT AND TUE AS THE HIGH DRIFTS OVER CENTRAL PA. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...LAPLANTE NEAR TERM...LAPLANTE SHORT TERM...LAPLANTE LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS TULSA OK
1201 AM CDT FRI SEP 11 2015 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. For the 6Z TAFs, a cold front will traverse the area overnight tonight, bringing thunderstorms to all sites. MVFR conditions will likely accompany storm cells as they move across a TAF site. Winds will increase out of the north after frontal passage and precipitation chances will slowly diminish. MVFR ceilings will likely persist into the mid morning at Northeast Oklahoma and Northwest Arkansas sites. && .PREV DISCUSSION... /ISSUED 908 PM CDT THU SEP 10 2015/ ..UPDATE... DISCUSSION... Thunderstorm complex over Kansas this evening is still on track to move into portions of northeast Oklahoma and northwest Arkansas around midnight as the strong cold front continues its southward push toward the area. Although an overall weakening trend should occur in the complex as a whole due to lower available shear this far south, mesoanalysis is indicative of instability that could support a limited threat of isolated damaging wind potential, especially along and north of Interstate 44. Given the current movement of the complex, expect a faster movement than projected by the new NAM but slower than the recent runs of the HRRR. It`s a good bet that most of northeast Oklahoma and northwest Arkansas will see rain prior to sunrise. Main changes to the forecast were to tweak the POPs some, including raising them along and north of Interstate 40 through 12z and also to delay the spread into most of southeast Oklahoma until after 09z. The rest of the forecast looks good to go. PREV DISCUSSION... /ISSUED 614 PM CDT THU SEP 10 2015/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. For the 0Z TAFs, a cold front will traverse the area overnight, bringing thunderstorms to all sites. MVFR conditions will likely accompany storm cells as they move across a TAF site. Winds will increase out of the north after frontal passage and precipitation chances will slowly diminish. MVFR ceilings will likely persist into the mid morning at Northeast Oklahoma and Northwest Arkansas sites PREV DISCUSSION... /ISSUED 355 PM CDT THU SEP 10 2015/ DISCUSSION... A cold front will move south across the area late tonight and Friday morning accompanied by scattered to numerous showers and thunderstorms. The HRRR is much quicker moving convection into and out of the area than most other models and have leaned towards this solution. A limited severe risk will exist especially near the Kansas and Missouri borders, and this is also the area where the greatest storm coverage is expected. Much cooler and drier air will move into the area for the weekend bringing our first taste of fall. Southerly winds will return and increase early next week resulting in a quick warmup. By the latter half of next week, temperatures will be several degrees above normal, and higher humidity levels will return as well. Rain chances look like they will hold off until the very end of the week when a frontal boundary will approach from the north. Stayed close to guidance temperatures the next couple days. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...06
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
154 AM EDT FRI SEP 11 2015 .SYNOPSIS... A COLD FRONT AND UPPER TROUGH WILL SLOWLY SWEEP OVER THE SOUTHERN APPALACHIAN REGION LATE THIS WEEK. BY EARLY NEXT WEEK...A COOL AND DRY AIR MASS IS FORECAST TO SETTLE OVER THE WESTERN CAROLINAS AND NORTHEAST GEORGIA. MOISTURE SHOULD BEGIN TO INCREASE OVER THE REGION BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... 130 AM UPDATE...NO MAJOR CHANGES NEED TO THE GOING FCST. STCU IS DEVELOPING IN THE WAKE OF MID/UPPER CLOUDS DEPARTING AND TEMPS/TDS ARE REMINING FAIRLY STEADY STATE. ANOTHER ROUND OF UPPER CLOUDS PUSHING IN FROM THE SW WILL HELP MAINTAIN RELATIVELY SLOW NOCTURNAL TEMP CURVES. KEEPING AN EYE ON DENSE FG FOR A POSSIBLE DFA ACROSS THE NC PIEDMONT/FHILLS WHERE GOOD COV PRECIP FELL LAST EVENING. 1015 PM UPDATE...ISOLATED CONVECTION CONTINUES ACROSS THE CHARLOTTE AREA INVOF A STALLED OUTFLOW BOUNDARY. AXIS OF SHORTWAVE TROUGH CAN BE SEEN ON WV IMAGERY...MORE OR LESS LINED UP WITH THE NC MTNS. ROUNDS OF WEAK ACTIVITY MAY FORM OVER THE NEXT COUPLE OF HOURS BUT INSTABILITY ALMOST CERTAINLY WILL BE USED UP BY THE TIME THE SHORTWAVE AXIS ARRIVES. MESO MODELS ARE NOT DOING MUCH AND THE HRRR IS TRENDING WEAKER WITH ITS DEPICTION OF NEW DEVELOPMENT OVER OUR AREA. A LINE OF CELLS OVER UPPER EAST TN IS MOVING SWD SLOWLY...BUT ARE NOT EXPECTED TO PUSH VERY FAR PAST THE NC BORDER. ALL REMAINING POPS ARE ISOLATED AND DIMINISH BELOW MENTIONABLE VALUES BY 200 A.M. ALREADY SEEING SOME LOWERING VSBYS ON AREA OBS...BUT STILL THINK THE THICKEST FOG WILL BE WHERE HEAVY RAIN FELL LATE IN THE DAY. REMAINDER OF PREVIOUS DISCUSSION...AS OF 225 PM...A COLD FRONT WAS ANALYZED WINDING FROM THE MID ATLANTIC TO THE TN VALLEY...TO THE SOUTHERN PLAINS. THE COLD FRONT WILL STALL IN THE MTNS FOR MUCH OF THE NIGHT...WHILE NWLY LLVL FLOW HELPS SCOUR OUT CLOUD COVER. SO PATCHY FOG AND STRATUS IS EXPECTED TO DEVELOP ACRS THE AREA...ESP WHERE THE HEAVIEST RAIN FALLS AND IN THE MTN VALLEYS. TEMPS WILL DROP A CATEGORY OR TWO COOLER THAN THIS MORNING/S LOWS FOR FRIDAY MORNING. FRIDAY...THE CWFA WILL BE IN BETWEEN SHORTWAVE TROFS AND BETWEEN SFC FRONTS. LLVL FLOW WILL REMAIN WLY TO NWLY...LIMITING MOISTURE AND LLVL CONVERGENCE. SO EXPECT ONLY ISOLATED TO WIDELY SCATTERED CONVECTION WITH PEAK HEATING FRIDAY AFTN. TEMPS WILL BE A CATEGORY OR TWO ABOVE NORMAL. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... AS OF 215 PM THURSDAY...LINGERING SCATTERED/ISOLATED DIURNAL CONVECTION IS EXPECTED TO WANE FRI EVENING...BUT POPS WILL INCREASE AGAIN TOWARD DAYBREAK ACROSS THE MTNS...AS A BAND OF DEEP MOISTURE ASSOCIATED WITH STRONG HEIGHT FALLS AND ASSOCIATED FRONTAL SURGE APPROACHES THE FORECAST AREA. WHILE THE MOIST BAND IS EXPECTED TO DIMINISH AS IT MOVES QUICKLY ACROSS THE FORECAST AREA DURING THE MORNING...MID-LEVEL DRY SLOT WILL OVERSPREAD THE AREA DURING THE AFTERNOON...WITH PART OF THE FRONT LIKELY GETTING HUNG UP A BIT ACROSS THE MOUNTAINS...LIKELY NOT COMPLETELY CLEARING THE AREA UNTIL A POTENT SHORT WAVE TROUGH MOVES ACROSS THE AREA DURING THE EVENING. AS A RESULT...THERE SHOULD BE PLENTY OF LOW LEVEL MOISTURE AND WARMTH LINGERING THROUGH THE DAY TO SUPPORT MODEST LEVELS OF INSTABILITY. TERRAIN EFFECTS AND THE FRONT SHOULD PROVIDE FOCI FOR SCATTERED CONVECTIVE DEVELOPMENT INTO THE AFTERNOON AND EARLY EVENING...ESP FROM THE BLUE RIDGE EAST...PRIMARILY WARRANTING CHANCE POPS. WITH CANADIAN HIGH PRESSURE BUILDING INTO THE REGION IN THE WAKE OF DEPARTING TROUGH/COLD FRONT...SUNDAY SHAPES UP TO BE A SPECTACULAR EARLY TASTE OF AUTUMN...WITH MAXES EXPECTED IN THE 70S AND DEWPOINTS LIKELY FALLING INTO THE 40S BY AFTERNOON. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 225 PM THURSDAY...THE EARLY PART OF THE MEDIUM RANGE WILL BE DOMINATED BY AN ANOMALOUSLY DEEP...YET PROGRESSIVE EAST COAST LONG WAVE TROUGH AND ASSOCIATED CANADIAN HIGH PRESSURE. THIS WILL SUPPORT A CONTINUATION OF EARLY FALL-LIKE WEATHER...WITH TEMPS/DEWPOINTS EXPECTED TO REMAIN BELOW CLIMO THROUGH AT LEAST TUESDAY. IN FACT... MON MORNING IS EXPECTED TO BE DOWNRIGHT CHILLY ACROSS THE HIGH ELEVATIONS...WITH TEMPS LIKELY DIPPING TO NEAR 40 ABOVE 4000 FEET OR SO. HEIGHT RISES BY THE END OF THE PERIOD WILL RESULT IN TEMPS CREEPING BACK TOWARD CLIMO...ALTHOUGH WITH SURFACE RIDGE AXIS EXPECTED TO PERSIST ACROSS THE REGION...DEWPOINTS SHOULD BE SLOWER TO RECOVER...AND IT APPEARS CHANCES FOR ANY DIURNAL CONVECTION...OR PRECIP OF ANY STRIPE WILL BE BELOW 20 PERCENT THROUGH THE PERIOD. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AT KCLT...MID AND UPPER LEVEL CLOUDS ARE DIMINISHING AND PUSHING OFF TO THE EAST WHICH WILL ALLOW MOISTURE TRAPPED IN WEAK SFC INVERSIONS TO INCREASE WITH RAD COOLING. WENT A LITTLE PESSIMISTIC WITH THE MORNING PERIOD DUE TO PREVIOUS PRECIP IN THE AREA AND CURRENT AREA OB TRENDS. FOR NOW...HAVE IFR CIGS/VSBY DEVELOPING AROUND 11Z...QUICKLY TRANSITIONING TO VFR CONDS AFT 13Z. PRECIP CHANCES ARE TOO LOW FOR A PROB30 MENTION THIS AFTERNOON AND WILL EXPECT MAINLY UPPER CLOUDS AFT 02Z. ELSEWHERE...TRICKY TAF SET FOR THE THE FIRST 6-8 HRS. LLVL STCU HAS ALREADY DEVELOPED ACROSS THE UPSTATE WITH IFR CIGS AT KGMU. WENT BELOW MODEL GUIDE FOR CIGS AND HAVE IFR CONDS AT ALL SITES AFT 09Z OR SO...THRU 13Z. KAVL AN KHKY WILL HAVE THE BEST CHANCE OF PRECIP AS FRONTAL ZONE IMPINGES ON THE NC MTNS LATE SO HAVE VCSH THESE SITES AFT 00Z. DOWNSLOPING NW/LY TO W/LY FLOW WILL INHIBIT CONVEC CHANCES OVER THE UPSTATE TO PRECLUDE A WX MENTION THIS AFTERNOON AND EVENING. OUTLOOK...UNSETTLED CONDITIONS WILL CONTINUE THROUGH THE WEEKEND AS A FRONT STALLS JUST EAST OF THE REGION...AND AN UPPER LEVEL LOW PRESSURE SYSTEM DRIFTS EAST THROUGH THE APPALACHIANS. MTN VALLEY FOG AND STRATUS ARE POSSIBLE EACH MORNING...WITH SCATTERED THUNDERSTORMS MAINLY IN THE AFTN. DRIER CONDITIONS WILL ARRIVE EARLY NEXT WEEK. CONFIDENCE TABLE... 06-12Z 12-18Z 18-24Z 00-06Z KCLT HIGH 91% HIGH 94% HIGH 100% HIGH 100% KGSP HIGH 97% HIGH 100% HIGH 100% HIGH 100% KAVL LOW 51% HIGH 82% HIGH 100% HIGH 100% KHKY HIGH 97% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 97% HIGH 100% HIGH 100% KAND MED 78% 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 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...RWH NEAR TERM...ARK/SBK/WIMBERLEY SHORT TERM...JDL LONG TERM...JDL AVIATION...SBK
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
408 AM CDT FRI SEP 11 2015 .DISCUSSION... CONVECTION STARTING A LITTLE EARLIER THIS MORNING AS A WEAK DISTURBANCE OVER NORTHERN MEXICO APPROACHES SOUTHEAST TEXAS. THE FLOW ALOFT REMAINS DIVERGENT AND PW VALUES REMAIN BETWEEN 2.10 AND 2.30 INCHES. RAP IS DOING A GOOD JOB THIS MORNING AND WILL LEAN TOWARD A GFS/ECMWF RAP BLEND. WILL CARRY LIKELY POPS TODAY WITH CONVECTION TRENDING TOWARD LESS COVERAGE OVER THE CENTRAL/COASTAL ZONES BY MID AFTN. WITH PW VALUES AOA 2.00 INCHES...THERE IS SOME POTENTIAL FOR LOCALLY HEAVY RAIN. STORM MOTION SHOULD BE BETWEEN 10-15 KNOTS BUT THERE IS A WEAK SFC TROUGH ALIGNED FROM KIAH TO KLRD AND THIS FEATURE COULD FOCUS SOME TRAINING THIS MORNING. AT 3 AM...A COLD FRONT WAS LOCATED FROM ABOUT JOPLIN MO TO ARDMORE OK TO CHILDRESS. THE FRONT WILL MOVE SLOWLY SOUTH TODAY AND TONIGHT AND CROSS SE TX LATE TONIGHT. THE FRONT MIGHT TRIGGER ADDITIONAL SHRA BUT MOST OF THE MOISTURE IS SHUNTED EAST AHEAD OF THE FRONT SO NOT EXPECTING MUCH MORE THAN ISOLATED TO WIDELY SCATTERED SHOWERS WITH THE FROPA. DRIER AIR WILL SLOWLY WORK INTO SE TX ON SATURDAY AND DEW PTS WILL LOWER INTO THE 50S NORTH OF I-10 DURING THE AFTN BUT REMAIN IN THE LOWER 70S ALONG THE COAST. DRIER AIR WILL COVER ALL OF SE TX SAT NITE THROUGH MONDAY. A WARM START TO SATURDAY COUPLED WITH THE DRIER AIR SHOULD YIELD SOME WARM TEMPS BUT LOWER 850 TEMPS ON SUNDAY SHOULD PRODUCE SLIGHTLY COOLER MAX TEMPS ON SUNDAY. A WEAK COASTAL TROUGH WILL DEVELOP OFF THE MEXICAN COAST MONDAY NIGHT AND THIS FEATURE WILL EXTEND NORTH ALONG THE TEXAS COAST. SYSTEM SHOULD REMAIN SOMEWHAT DISORGANIZED AS UPPER LEVEL WINDS OF 30 KNOTS SHOULD PROVIDE ENOUGH SHEAR TO INHIBIT DEVELOPMENT. THE TROUGH WILL FOCUS HIGHER MOISTURE ALONG THE TEXAS COAST ON TUES/WED. NOT SURE HOW FAR INLAND MOISTURE WILL GET AND HAVE TAPERED POPS RATHER SIGNIFICANTLY FROM KGLS TO KCLL. THE ELONGATED SURFACE TROUGH WEAKENS AND WILL MOVE INLAND WEDNESDAY NIGHT. RAIN CHANCES SHOULD DECREASE AGAIN THU/FRI AS UPPER LEVEL RIDGING EXPANDS OVER NORTHERN MEXICO AND IMPINGES ON SE TX. 43 && .MARINE... EXPECT ANOTHER PERIOD OF SHOWERS AND THUNDERSTORMS OVER THE COASTAL WATERS TODAY AND A FRONTAL PASSAGE IS EXPECTED SATURDAY MORNING WITH OFFSHORE WINDS DEVELOPING BEHIND THE FRONT. THE MODELS DO NOT INCREASE WIND SPEEDS UNTIL SUNDAY WHEN AT LEAST CAUTION CONDITIONS ARE EXPECTED. A GRADUAL DECREASE IN WIND SPEEDS WILL THEN OCCUR ON MONDAY AND A MORE SOUTHEASTERLY FLOW IS EXPECTED TO DEVELOP MONDAY NIGHT AND TUESDAY. 40 && .CLIMATE... HOUSTON HOBBY AIRPORT RECEIVED 0.68 INCHES OF RAIN YESTERDAY. THAT BRINGS THE 2015 ANNUAL TOTAL TO 54.79 INCHES WHICH EXCEEDS THE 1981-2010 30 YEAR AVERAGE RAINFALL OF 54.65 INCHES. IN OTHER WORDS...HOBBY EXCEEDED THEIR NORMAL YEARLY RAINFALL IN JUST OVER NINE MONTHS. WITH THREE MONTHS TO GO...THE 2015 TOTAL WILL LIKELY GROW. 43 .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 89 73 88 62 86 / 50 30 10 10 0 HOUSTON (IAH) 87 73 88 63 83 / 70 30 20 10 0 GALVESTON (GLS) 84 76 84 74 84 / 60 50 30 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1223 AM CDT FRI SEP 11 2015 .DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. && .AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE OVERNIGHT HOURS WITH CIRRUS DEBRIS LEFTOVER FROM CONVECTION OUT WEST. VFR WILL INITIALLY PREVAIL DURING THE MORNING HOURS OF FRIDAY AS A WEAK COLD FRONT APPROACHES FROM THE NORTH...WITH DEGRADED AVIATION CONDITIONS EXPECTED TOMORROW AFTERNOON AND NIGHT AS THE FRONT INTRUDES INTO DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY. && .PREV DISCUSSION... /ISSUED 647 PM CDT THU SEP 10 2015/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...MOISTURE WILL CONTINUE TO POOL ACROSS SOUTHERN TEXAS WELL SOUTH OF A COLD FRONT LOCATED IN CENTRAL TEXAS. SCATTERED SHOWERS AND STORMS HAVE BEEN ONGOING THIS AFTERNOON MAINLY NORTH OF THE VALLEY AND HAVE BEEN SHOWING A DECREASING TREND OVER THE PAST HOUR AND THIS IS ECHOED IN THE MOST RECENT HRRR MODEL. OVERNIGHT TONIGHT WILL SEE A MIX OF MAINLY HIGH CLOUDS FROM CONVECTION TO THE NORTH AND FEW-SCT LOW CLOUDS DEVELOPING IN MOIST CONDS ACROSS DEEP SOUTH TEXAS. WINDS WILL LAY DOWN AROUND MID EVENING AND REMAIN BELOW 10 KTS THROUGH AROUND MID MORNING. CUMULUS WILL DEVELOP 14-15Z AROUND 2500 FEET AND WINDS WILL BEGIN TO PICK UP AT THIS TIME WITH GUSTS 18-22 KNOTS THROUGH THE AFTERNOON HOURS. RAIN CHANCES INCREASE LATE MORNING AND AFTERNOON WITH MAINLY ISOLD TO SCT SEABREEZE CONVECTION AFFECTING THE TAF SITES WITH MORE ORGANIZED CONVECTION AFFECTING WEST OF RGC-HBV LATE AFTERNOON. WILL INSERT VCTS TO THE TAF SITES BEGINNING LATE MORNING FRIDAY. TEMPO MVFR CONDS CAN BE EXPECTED UNDER ANY STORM FRIDAY. PREV DISCUSSION... /ISSUED 230 PM CDT THU SEP 10 2015/ SHORT TERM /NOW THROUGH FRIDAY NIGHT/...MORE ACTIVE WEATHER PATTERN SETTING UP FOR THE SHORT TERM AS THE FIRST AUTUMN COLD FRONT MOVES THROUGH TEXAS. DEEP TROPICAL MOISTURE IS SETTLING INTO THE REGION ALREADY...WITH PW VALUES ALREADY ABOVE 2 INCHES. MOISTURE COMPRESSING AHEAD OF THE FRONT AND SMALLER BOUNDARIES HAVE ALREADY SPARKED A FEW SHOWERS ALONG THE SEABREEZE TODAY...BUT INSTABILITY ALOFT HAS STAYED WELL OFFSHORE STILL. TOMORROW WITH THE FRONT IN THE VICINITY...RAIN CHANCES ARE LIKELY AREAWIDE... STARTING TO THE NORTH AND MOVING SOUTHWARD ALONG AND AHEAD OF THE FRONT. WITH PW VALUES FORECAST ABOVE 2.2 INCHES...ANY RAINFALL WILL LIKELY BE VERY HEAVY IN SOME LOCATIONS. SINCE STORMS ARE FIRING WITH A MOVING BOUNDARY...CELLS WONT BE IDLING ON ONE LOCATION FOR A LONG PERIOD OF TIME. THE MAIN FOCUS TIME FOR THE RAINFALL WILL BE LATE TOMORROW AFTERNOON THROUGH SUNRISE SATURDAY. RAINFALL AMOUNTS ABOVE 3 INCHES ARE POSSIBLE...ESPECIALLY ACROSS THE WESTERN VALLEY. CLOUD COVER WILL ALSO BE HIGHER TOMORROW... SO HIGH TEMPERATURES WILL STRUGGLE TO REACH 90 DEGREES... ESPECIALLY FOR THE NORTHERN RANCHLANDS. LONG TERM /SATURDAY THROUGH WEDNESDAY/...THE BEST LIFT SHOULD BE FRIDAY AND FRIDAY NIGHT...WITH HIGH PRESSURE AND DRIER AIR CONTINUING TO FILTER INTO THE AREA ON SATURDAY CAN NOT RULE OUT SOME LINGERING MODERATE RAIN POTENTIAL EARLY SATURDAY...BUT THE MODELS SEEM TO AGREE WITH PUSHING MOST OF THE ENERGY SOUTH OF THE RIVER BY LATE IN THE DAY. THE CANADIAN DIFFERS SLIGHTLY WITH HIGHER QPF ALONG THE COAST SATURDAY MORNING...AS OPPOSED TO OVER THE MID AND UPPER VALLEY PER THE GFS/ECMWF. TIME HEIGHT SHOWS DRIER MIDLEVEL AIR MOVING IN SATURDAY AS DEEPER NORTHEAST WINDS SET UP. THUS...LIGHTER RAINS...WITH A FEW HEAVIER SHOWERS AND AN EMBEDDED THUNDERSTORM EARLY...WILL BE THE RULE SATURDAY. TROPICAL...BOTH THE GFS AND ECMWF MAINTAIN LOW PRESSURE IN THE SOUTHWEST GULF THROUGH THE WEEKEND...DRIFTING A WEAK CIRCULATION NORTH ALONG THE MEXICAN COAST TOWARD BROWNSVILLE BY TUESDAY...WHERE IT WILL REMAIN IDENTIFIABLE AS A FEATURE. MARINE... NOW THROUGH FRIDAY NIGHT...MAIN MARINE THREAT IS CONTINUED THUNDERSTORM ACTIVITY THROUGH THE SHORT TERM. MARINE INSTABILITY WILL BRING INCREASED COVERAGE OVERNIGHT TONIGHT...ESPECIALLY FURTHER OFFSHORE NEARER THE MIDLEVEL TROUGH. SEAS WILL REMAIN 2 TO 3 FEET...EXCEPT FOR HIGHER AGITATION NEAR STORMS. THE COLD FRONT ARRIVES LATE TOMORROW...WITH A MODEST WIND SHIFT TO THE NORTHEAST. SINCE THE FRONT IS ALREADY SLOWING DOWN WHEN IT ARRIVES...NORTHEAST FLOW WILL REMAIN 15KTS OR LESS BEHIND THE WIND SHIFT. THIS WILL KEEP THE SEAS FROM BUILDING SIGNIFICANTLY BEHIND THE FRONT...STAYING ABOUT 3 FEET. SATURDAY THROUGH MONDAY...LIGHT TO MODERATE WINDS AND LOW TO MODERATE SEAS WILL PREVAIL ALONG THE LWR TEXAS COAST INITIALLY... BUT A SURGE OF HIGH PRESSURE WILL PRODUCE A MODERATE NORTHEAST WIND...HELPING TO BUMP SEAS UP A COUPLE OF FEET SUNDAY THROUGH MONDAY AS A WEAK COLD FRONT PASSES THROUGH. .BRO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1156 PM CDT THU SEP 10 2015 .AVIATION... SHORT TERM HIGH RESOLUTION MODELING FOCUS EARLY MORNING CONVECTION ALONG THE COAST...EXPANDING PRECIPITATION INLAND INTO THE EARLY AFTERNOON HOURS. A NEAR CALM WIND FIELD WITHIN THIS VERY MOIST AIR MASS MAY INDUCE BRIEF PERIODS OF NEAR SUNRISE MVFR CEILINGS...POSSIBLE VSBY RESTRICTIONS IN BR OVER MORE RURAL HUBS THAT EXPERIENCED RAINFALL TODAY. VFR CEILINGS...MVFR CONDITIONS WITHIN HEAVY RAINFALL/STORMS. GENERALLY ONSHORE WINDS...BECOMING VARIABLE AFTER SUNSET. 31 && .PREV DISCUSSION... DISCUSSION... WILL KEEP THE FORECAST AS IS THIS EVENING. LOOK FOR POSSIBLE SHOWER/ THUNDERSTORM DEVELOPMENT MAINLY TOWARD THE COAST IN THE MORNING WITH ACTIVITY DEVELOPING FURTHER INLAND DURING THE DAY. TOMORROW`S CHANCE FOR STORMS LOOKS BEST NEAR THE COAST WITH THE LOWER VALUES INLAND... JUST AS THE CURRENT FORECAST SAYS. LOCALLY HEAVY RAINFALL IS POSSIBLE ONCE AGAIN TOMORROW WITH HIGH PRECIPITABLE WATER VALUES STILL ACROSS THE AREA. SIMILAR TO TODAY...WOULD NOT BE SURPRISED TO SEE 1 TO 2 INCH TOTALS WITH ISOLATED SPOTS GETTING INTO A 2 TO 4 INCH RANGE. LOCALIZED FLOODING WILL ONCE AGAIN BE POSSIBLE WITH THESE NUMBERS. 42 PREV DISCUSSION... AVIATION... CONVECTION DYING OUT OVER THE NEXT HOUR...SCATTERED LOW TO MID LEVEL DECKS SHOULD CLEAR OUT TO SKC OR SCT250 BY 03Z. VERY BRIEF PERIODS OF INTERIOR RURAL MVFR DECKS AT...OR SHORTLY AFTER...SUNRISE. RETURNING SHOWERS WITH ISOLATED STORMS CLOSER TO THE COAST DURING DAYLIGHT MORNING HOURS...TRANSITIONING TO MORE WIDESPREAD RAIN AND NUMEROUS CLUSTERED STORMS FROM AROUND 17Z THROUGH 22-23Z. SIMILAR LARGE SCALE SETUP WITH BROAD WEAK TOUGHING OVER THE STATE...ENOUGH LOWER LEVEL MOISTURE AND INSTABILITY TO COMMENCE CONVECTION ONCE MID 80S SURFACE TEMPERATURES ARE MET. 31 PREV DISCUSSION... DISCUSSION... RADAR THIS AFTERNOON SHOWS WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY WITH THE STRONGEST STORMS OVER E HARRIS COUNTY WHERE STORMS ARE PRODUCING RAIN RATES OF 2 INCHES AN HOUR. THERE IS ALSO A BAND OF ACTIVITY ALONG A STALLED FRONTAL BOUNDARY FROM AUSTIN TO COLLEGE STATION EAST TO JASPER. LATEST TRENDS WITH THE HRRR MODEL SEEM TO SHOW ACTIVITY ENDING BETWEEN 00-03Z THIS EVENING. WATER VAPOR IMAGE LOOP SHOWS A WEAK JET STREAK/SHORTWAVE PUSHING THROUGH THE REGION THIS AFTERNOON WHICH MAY BE HELPING TO ENHANCE CONVECTION. OVERALL UPPER LEVEL PATTERN IS ON TRACK WITH A STRONGER SHORTWAVE TROUGH DEVELOPING OVER THE N ROCKIES WHICH WILL HELP AMPLIFY THE TROUGH FROM SW OF HUDSON BAY TO THE UPPER MIDWEST TONIGHT INTO FRIDAY. WITH PRECIP WATER VALUES OVER 2 INCHES TOMORROW AND FAVORABLE UPPER LEVEL PATTERN...FORECAST WILL HOLD ONTO 60/70 POPS. GFS/NAM/ECMWF ALL SUPPORT SHOWER AND THUNDERSTORM ACTIVITY SIMILAR TO TODAY`S ACTIVITY. THERE WILL ALSO BE AN ADDED TROUGH AXIS THAT PUSHES THROUGH FRI TO HELP INCREASE LARGE SCALE LIFT. AS HAS BEEN THE CASE TODAY...EXPECTING A GENERAL 1 TO 2 INCHES OF RAIN WITH ISOLATED HIGHER AMOUNTS. SINCE CONVECTION WILL BE PULSE TYPE...VERY WELL COULD HAVE AREAS THAT GET NO RAINFALL BUT THEN AREAS THAT GET TOO MUCH. THERE MAY BE FLOODING ASSOCIATED WITH ANY OF THE HIGHER AMOUNTS BUT A WIDESPREAD FLOOD THREAT IS NOT EXPECTED AT THIS TIME. GIVEN THE MORE AMPLIFIED PATTERN FRIDAY INTO SATURDAY...COLD FRONT WILL BE PUSHING THROUGH THE AREA AND OFF THE COAST. LATEST TIMING FROM THE NAM/GFS/ECMWF SHOWS IT REACHING COLLEGE STATION TO HUNTSVILLE AROUND 1-3AM SATURDAY...REACHING HOUSTON CLOSER TO 6-8AM AND OFF THE COAST BEFORE NOON SATURDAY. WINDS SHOULD SHIFT TO THE N/NE. THE MUCH DRIER COOLER AIRMASS WILL LIKELY LAG BEHIND THE FRONT AND NOT ARRIVE UNTIL LATER IN THE AFTERNOON AND OVERNIGHT. THERE DOES NOT APPEAR TO BE MUCH OF A CHANCE OF THUNDERSTORMS WITH THE FRONT BUT GIVEN THE MOISTURE CONTENT WILL AT LEAST HAVE A 30 PERCENT IN THE FORECAST. WEATHER CONDITIONS SUNDAY/MONDAY WILL CERTAINLY GIVE EVERYONE A GOOD TASTE OF FALL WEATHER WITH LOW TEMPS IN THE LOW 60S...PERHAPS UPPER 50S FOR AREAS NORTH OF HOUSTON. HIGH TEMPERATURES WILL BE IN THE MID 80S. ENJOY IT WHILE YOU CAN BECAUSE THE MOISTURE SHOULD BE BACK TUESDAY THROUGH THURSDAY NEXT WEEK. EXTENDED FORECAST...STILL VERY UNCERTAIN WITH REGARDS TO A SURGE OF TROPICAL MOISTURE EXPECTED TO PUSH INTO THE AREA TUESDAY AND WEDNESDAY. GFS HAS BEEN VERY CONSISTENT AND HAS HAD ENSEMBLE SUPPORT OF MAINLY A SURFACE COASTAL TROUGH DEVELOPING IN THE W GULF AND PUSHING NORTH TOWARDS THE AREA. THE ECMWF THE LAST 2 RUNS HAS NOW TAPPED THE BREAKS ON TROPICAL CYCLONE FORMATION ALTHOUGH IT STILL WANTS TO DEVELOP SOME TYPE OF LOW PRESSURE WHICH IT SLOWLY PUSHES TOWARDS THE LOWER TEXAS COAST NEXT WEEK. GFS CONTINUES TO HOLD ONTO SOME W SHEAR ACROSS THE N GULF WITH THE ECMWF STILL HAVING SOMEWHAT OF A RIDGE. THE DIFFERENCES IN THE PATTERNS WILL LIKELY DETERMINE HOW MUCH SHEAR DEVELOPS OVER THE NW GULF AND IF THERE IS ANY DEVELOPMENT. AT THIS POINT IT DOES NOT LOOK LIKELY BUT WE WILL STILL NEED TO MONITOR FORECAST DATA. 39 MARINE... NOT TOO MANY CHANGES WITH THE SHORT TERM PART OF THE FCST AS MOSTLY LIGHT ONSHORE WINDS PREVAIL...ALONG WITH THE WIDESPREAD STORMS THRU TOMORROW(FRI). MODELS STILL IN DECENT AGREEMENT WITH THE PASSAGE OF A WEAK COLD FRONT INTO THE COASTAL WATERS EARLY SAT MORNING. GENERALLY LIGHT/MODERATE NE WINDS TO DEVELOP IN ITS WAKE...FROM SAT AFTN INTO SUN MORNING. AS THIS FRONT DISSIPATES OVER THE GULF AND A WEAK TROF OF LOW PRESSURE BEGINS TO DEVELOP NEAR THE LOWER TX COAST...WE SHOULD START SEEING A MORE EASTERLY FETCH DEVELOP OVER THE UPPER TX COAST SUN AFTN/EVE. THIS FEATURE WILL THEN HELP TO BRING PERIODS OF SHRA/TSRA AND PERHAPS A PROLONGED PERIOD OF ESE WINDS TO THE REGION FOR THE FIRST HALF OF NEXT WEEK. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 74 89 71 86 61 / 30 40 30 10 10 HOUSTON (IAH) 74 87 71 86 62 / 40 60 30 20 10 GALVESTON (GLS) 78 84 76 86 72 / 50 70 50 30 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...42 AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1142 PM CDT THU SEP 10 2015 .AVIATION... GREATEST CONCERNS THIS ITERATION CONTINUE TO REVOLVE AROUND THUNDER CHANCES AND A FROPA. A SOUTHEAST MOVING LINE OF THUNDERSTORMS CURRENTLY IN THE NORTHEAST TEXAS PANHANDLE WILL AFFECT KCDS BY AROUND 09Z...IF IT CAN MAINTAIN ITSELF. CONFIDENCE IN SHOWERS AND SOME THUNDER AFFECTING KCDS IN THE PREDAWN HOURS IS NOW HIGH ENOUGH TO INCLUDE IN THE TAF. FURTHER WEST..KPVW AND KLBB COULD ALSO SEE CONVECTION ATTEMPT TO FORM AS OUTFLOW FROM THE PANHANDLE COMPLEX ADVANCES SOUTHWARD...THOUGH CONFIDENCE IN THIS IS LOWER AND HAS NOT BEEN INCLUDED EXPLICITLY IN THE TAFS. THE CONVECTIVE OUTFLOW MAY BRING A NORTHERLY WIND SHIFT /OR ERRATIC WINDS/ TO ALL OF THE TERMINALS BEFORE DAWN...WITH BREEZY NORTHEASTERLY WINDS THEN TO BUILD IN AS THE FRONT MOVES THROUGH BY LATE MORNING. ADDITIONAL STORM DEVELOPMENT WILL BE POSSIBLE BEHIND THE FRONT FRIDAY AFTERNOON...WITH THE GREATEST CONFIDENCE BEING AT KLBB AND KPVW...WHERE PROB30 GROUPS WERE INCLUDED. OUTSIDE OF THE CONVECTION...VFR CONDITIONS SHOULD PREVAIL THROUGH THE DAY...WITH PERHAPS A RISK OF LOWER CLOUDS DEVELOPING FRIDAY EVENING/NIGHT. && .PREV DISCUSSION... /ISSUED 304 PM CDT THU SEP 10 2015/ SHORT TERM... A PROMINENT FEATURE IN THE WEATHER TODAY HAS BEEN A BAND OF CIRRUS ARCING FROM CENTRAL ARIZONA ACROSS WEST TEXAS. THIS IS ASSOCIATED WITH SOME TROPICAL MOISTURE CAUGHT UP IN THE CIRCULATION OF DECAYING TROPICAL STORM LINDA OFF THE WEST COAST OF BAJA. UPPER-AIR ANALYSIS SHOWS THAT THIS MOISTURE IS LIMITED TO THE UPPER TROPOSPHERE WITH MID-LEVELS REMAINING FAIRLY DRY AND UNSUPPORTIVE OF ANY CONVECTIVE DEVELOPMENT. HOWEVER...WE ARE SEEING SOME DEVELOPMENT ACROSS NORTH- CENTRAL NEW MEXICO IN VICINITY OF THE RATON MESA. NORTHWEST FLOW ALOFT WILL CARRY THIS ACTIVITY TO THE SOUTHEAST THIS EVENING TOWARD THE FAR SOUTHWEST TEXAS PANHANDLE ASSUMING IT SURVIVES THE TREK ACROSS THE NORTHEAST NEW MEXICO PLAINS. THE HRRR IS ABOUT THE THE ONLY MODEL THAT INDICATES THIS...BUT WE WILL MAINTAIN A SLIGHT CHANCE MENTION ACROSS MUCH OF THE SRN TX PANHANDLE BETWEEN 00 AND 06 UTC TO ACCOUNT FOR THIS POSSIBILITY. BETTER T-STORM/RAIN CHANCES SHOULD ARRIVE EARLY FRIDAY MORNING AS A FAIRLY SHARP COLD FRONT MOVES IN FROM THE NORTH IN CONJUNCTION WITH A GLANCING BLOW FROM A SHORTWAVE MOVING SOUTHEAST THROUGH THE PLAINS. THE FRONT IS CURRENTLY MOVING INTO NORTHERN KANSAS AND THERE IS SOME UNCERTAINTY REGARDING IT/S TIMING INTO OUR FORECAST AREA OWING TO THE IMPACT OF CONVECTIVE OUTFLOWS ON THE FRONT. IN ADDITION...IT IS UNCERTAIN WHETHER OR NOT THE FRONTOGENETIC FORCING WILL SYNCH UP WITH THE BEST LARGE-SCALE ASCENT ASSOCIATED WITH THE PASSING WAVE. FINALLY...THE TIMING OF THE FRONT...PASSING THROUGH THE AREA ROUGHLY BETWEEN 12 UTC AND 18 UTC...IS NOT OPTIMAL FOR THE GENERATION OF INSTABILITY AVAILABLE FOR CONVECTION. WITH THIS IN MIND...WE HAVE KEPT POPS IN THE CHANCE CATEGORY FOR THE AREA ON FRIDAY AS THE LINGERING UNCERTAINTY DOES NOT LEND ITSELF FOR LIKELY OR CATEGORICAL POPS. IN GENERAL...GUIDANCE FAVORS A BROAD ZONE OR CLUSTER OF ALONG AND POST- FRONTAL SHOWERS AND THUNDERSTORMS FRIDAY MORNING FOLLOWING THE FRONT FROM NORTHEAST TO SOUTHWEST....AND GRADUALLY TAPERING OFF FROM THE NORTHEAST DURING THE AFTERNOON. BREEZY NORTHEAST WINDS WILL DEVELOP BEHIND THE FRONT AND LAST THROUGH THE AFTERNOON. TEMPERATURES WILL BE MARKEDLY COOLER ACROSS THE NORTH...WITH HIGHS IN THE MID TO UPPER 70S ACROSS THE FAR SW TEXAS PANHANDLE AND NORTHERN SOUTH PLAINS. DEPENDING ON THE TIMING OF THE FRONT...WE MAY STILL STILL SOME HIGH TEMPS REACH 90 DOWN IN THE SOUTHERN ROLLING PLAINS. LONG TERM... MID-LEVEL DRYING WILL ADVANCE SLOWLY SW BY FRIDAY EVENING IN THE WAKE OF THE 850-700 MB COLD FRONT. THE DRIEST SURFACE RIDGING WILL LAG UNTIL SATURDAY MORNING...SO POST-FRONTAL STRATUS AIDED BY E-NE WINDS SHOULD LINGER ESPECIALLY ON THE CAPROCK BEFORE ERODING BY MIDDAY SAT. SOME OF THIS STRATUS IS PROGGED TO BE SUFFICIENTLY THICK FRI NIGHT THAT A FEW SHOWERS COULD MATERIALIZE FROM WEAK FN FORCING ALONG THE AFOREMENTIONED ELEVATED FRONTAL LAYER...BUT POPS OVERALL WERE SKIMMED BACK EVEN FURTHER THAN BEFORE. SAT MORNING WILL SEE SURFACE WINDS VEER SELY BEHIND THE PROGRESSIVE SURFACE RIDGE AND THIS PROCESS WILL AID IN WEAK ISENTROPIC LIFT ACROSS THE WESTERN HALF OF THE CWA COINCIDENT WITH A MODEST AXIS OF HIGHER PWATS. WHILE SATURATED DEPTHS ARE NOT MUCH TO WRITE ABOUT... THE BRUNT OF THIS SATURATION IS BELOW 700 MB WHICH COULD BE WRUNG OUT IN THE FORM OF SPRINKLES OR EVEN DRIZZLE PROVIDED STRATUS CAN DESCEND LOW ENOUGH AT TIMES. CLEARING SKIES BY MIDDAY COULD OPEN THE DOOR TO WEAK CAPE ACROSS EASTERN NM UNDERNEATH 10-20 KNOTS OF NW FLOW...HOWEVER NO DISCERNIBLE BACKGROUND SUPPORT PRECLUDES FURTHER POPS AT THIS TIME. EVEN WITH CLEARING...BELOW NORMAL HIGHS REMAIN ON TRACK GIVEN OUR PROXIMITY TO THE SURFACE RIDGE. THIS COOL THEME WILL BE SHORT LIVED AS SUNDAY AND BEYOND FEATURE LEE TROUGHING BENEATH AMPLIFYING SW FLOW. SIDED CLOSE TO THE WARMEST MEX AND ECE MOS HIGHS NEXT WEEK AS THIS LOOKS TO BE A VERY DRY AND BREEZY PATTERN FOR WEST TX. SUCH DRY SOILS IN THIS SETUP ARGUE IN FAVOR OF A RATHER STRONG DIURNAL TEMP RANGE...SO LOWS WERE NUDGED BELOW THE MILD SUPERBLEND VALUES. A SMALL WINDOW FOR MID-LEVEL MOISTENING MAY UNFOLD NEAR MIDWEEK AS A BROAD TROUGH LIFTS NORTHEAST OUT OF THE FOUR CORNERS. MONSOONAL MOISTURE ALOFT WILL LIKELY BE THINNED OUT BY THIS TIME...BUT SOME UPTICK IN PWATS MAY BE REALIZED BY TUE AND WED AS THE SW FLOW TURNS WEAKLY CYCLONIC. WHETHER THIS RESULTS IN PRECIP ALONG A DRYLINE IN/NEAR OUR AREA IS TOO UNCERTAIN...ESPECIALLY WITH OUR REGION RESIDING LARGELY SOUTH OF THE UPPER JET MAXIMA. LUB WATCHES/WARNINGS/ADVISORIES... NONE. $$ && .PRELIMINARY POINT TEMPS/POPS... FRIONA 60 76 55 76 / 20 50 20 10 TULIA 62 77 55 77 / 20 50 10 10 PLAINVIEW 62 79 55 77 / 20 40 10 10 LEVELLAND 62 82 56 76 / 10 40 20 10 LUBBOCK 63 82 57 77 / 10 40 20 10 DENVER CITY 63 85 58 77 / 10 40 30 10 BROWNFIELD 63 84 57 77 / 10 40 20 10 CHILDRESS 68 82 59 81 / 10 40 10 0 SPUR 66 85 58 79 / 10 40 10 0 ASPERMONT 69 90 60 82 / 10 40 10 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/07/23
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1008 AM CDT FRI SEP 11 2015 .UPDATE... ISSUED AT 1007 AM CDT FRI SEP 11 2015 Back edge of precipitation shield is now generally east of a Bloomington to Springfield line, and the clearing line is trying to penetrate the Illinois River Valley. However, clouds are increasing a bit over northern Illinois in response to a shortwave swinging southeast across Iowa, and latest RAP model guidance indicates periods of diurnal clouds through the afternoon across the western CWA as the associated cold air aloft settles into the area. Much of this area should remain dry this afternoon, but the wind trajectory off Lake Michigan will combine with the trough to keep clouds and some showers lingering across the east through the afternoon. A couple thunderstorms may occur as well with some higher lapse rates aloft. Recent zone/grid update updated the precipitation trends, and nudged high temperatures down a bit across the east where the clouds will persist the longest. && .SHORT TERM...(TODAY) ISSUED AT 334 AM CDT FRI SEP 11 2015 A weakening MCS over Missouri continues to move east toward southern IL early this morning while an upper level shortwave approaches central IL via Iowa. A cold front at the surface has pushed southward to around I-64 however convergence aloft due to the interaction of the above features is triggering numerous thunderstorms across central IL. Modest instability generally under 500 J/kg according to SPC mesoscale analysis has kept most of the storms fairly weak to moderate...however some heavy rainfall corridors have developed due to orientation of repeated thunderstorms. This system will gradually move eastward through the early afternoon with thunderstorms tapering off from west to east. Meanwhile...much colder air aloft moving into the region from the north will bring lake effect rain showers off of Lake Michigan...some of these could trigger a some more showers and isolated thunder out to Vermilion and Champaign counties and this is hinted at by several models. Highs today will only reach the lower 70s given the cooler post frontal air mass which has moved in. .LONG TERM...(TONIGHT THROUGH Thursday) ISSUED AT 334 AM CDT FRI SEP 11 2015 Much cooler temperatures expected this weekend due to strong upper level trof/low pressure digging southward from the western great lakes into IL/IN and ohio river valley through Saturday. Have a slight chance of showers into mid evening from Bloomington to Champaign to Paris northeast. Then isolated chances of showers returns on Sat with partly to mostly cloudy skies and breezy north winds, especially east of the IL river with best chances over east central IL. Lows tonight in the upper 40s/lower 50s with mildest readings south of I-72. Cool highs Saturday mostly in the mid 60s. Strong upper level trof pushes east of IL Sat night and Sunday while 1025 mb Canadian high pressure over ND settles into the mid MS river valley Sunday morning. Clouds and wind decrease Sat night and sets us up for cooler night with lows 43-48F. A pleasant day expected Sunday with ample sunshine and highs in the lower 70s, expect a few upper 60s in eastern IL. Not quite as cool Sunday night as high pressure slips SE of IL toward the central Appalachians. Lows around 50F in eastern IL and mid 50s near the MS river valley of west central IL. 00Z medium and extended range models show upper level high pressure ridge building across the eastern U.S. Monday through Wed and providing dry and warmer weather to IL. Highs Monday in the mid to upper 70s with west central IL near 80F, climb into the lower 80s Tue and mid 80s Wed and back to the lower 80s Thu. A cold front to push into the southern Great Lakes by sunset Thursday and to bring an increasing chance of showers and thunderstorms Thu/Fri. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Saturday MORNING) ISSUED AT 654 AM CDT FRI SEP 11 2015 Showers and isolated thunderstorms continue this morning across central IL. IFR/MVFR conditions and isolated TSRA are mainly confined to areas SE of KDEC-KCMI. Conditions will continue to improve from west to east through afternoon as the current system shifts eastward. However...continued lake effect rain showers may linger as far west as KCMI through evening from a band extending off of Lake Michigan. Clearing expected overnight as a shortwave high pressure ridge aloft crosses the area. Winds north throughout the period...generally 6-12 kts. Gusts 16-20 kts during afternoon today. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SHORT TERM...Onton LONG TERM...07 AVIATION...Onton
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
628 AM CDT FRI SEP 11 2015 .DISCUSSION... IFR CONDITIONS WILL REMAIN THROUGH MID-MORNING FOR TERMINAL SITES ALONG AND SOUTH OF I-20...INCLUDING KTYR...KLFK...KGGG...KMLU...KLFK AND KSHV WITH FOG/FG REDUCING VISIBILITY TO ONE HALF TO ONE QUARTER OF AN MILE. KTXK AND KELD MAY SEE BRIEF MIST/BR BUT WITH VISIBILITY RESTRICTIONS OF 3-5 STATUTE MILES. FLIGHT CATEGORIES WILL SLOWLY IMPROVE DURING THE MID TO LATE MORNING TO MVFR AND THEN MOSTLY VFR BY MID DAY TO EARLY AFTERNOON. A COLD FRONT WILL MOVE THROUGH THE FOUR STATE REGION DURING THE DAY PROVIDING COOLER AND DRIER AIR. A FEW ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE WITH THE PASSAGE OF THE BOUNDARY. LIGHT AND VARIABLE WINDS WILL PREVAIL UNTIL THE FRONT MOVES THROUGH SHIFTINGTHE WINDS TO THE NORTH TO NORTHEAST 5-8 KNOTS. /21/ && .PREV DISCUSSION... /ISSUED 5 AM CDT FRI SEP 11 2015/ .DISCUSSION... OUR SURFACE WINDS ARE LIGHT S/SW OR CALM WITH MUGGY UPPER 60S OR LOWER 70 DEW POINTS FOR MOST OF THE FOUR STATE AREA. SOME LOWER 60S LINGER NORTH OF A STATIONARY FRONT WITH LOW TO MID 60S. AIR TEMPERATURES ARE LIKE WISE...COOLER NORTH OF THE OLD STATIONARY FRONTAL BOUNDARY WITH LOW TO MID 70S ALONG AND SOUTH OF I-20. SKIES ARE FAIR TO PARTLY CLOUDY WITH SOME PATCHY FOG MAINLY SOUTH WHERE SOILS ARE FRESHLY DAMP. THE KSHV 88D IS QUIET...BUT THERE IS SOME DRIZZLE WITH THE FOG OVER DEEP EAST TEXAS AND THUNDERSTORMS ON APPROACH FROM THE NORTH. HOWEVER...GUST FRONTS ARE SEEN ON RADAR MOSAICS MOVING OUT AHEAD OF THE MAIN PRECIP AREA AND WILL CONTINUE TO DIMINISH BASED ON GUIDANCE. THE HRRR SHOWS SOME NEW DEVELOPMENT BY MID MORNING AND WITH HEATING ALL AFTERNOON. THE NAM EVEN GOES WELL INTO THE EVENING HOURS AS THE FRONT IS STILL FAR TO THE NORTH. THE OUTFLOW BOUNDARY COMING WILL BE THE MAIN...BUT NOT THE ONLY FOCUS WITH SOME LOW LEVEL VARIATIONS AND GOOD HEATING STILL LIKELY. THE CURRENT SURFACE FLOW IS VERY SHALLOW AS OUR VAD PROFILER IS SHOWING NORTHERLY FLOW AT ALL LEVELS FROM 1KFT ON UP. THE MOISTURE WILL BE SLOW TO SCOUR UNTIL THE FRONT ARRIVES LATE WITH EVEN HRRR SHOWING SOME WIDELY SCATTERED ACTIVITY ALONG AND SOUTH OF I-30 INTO THE EARLY EVENING. SO CHECK THE RADAR FOR ALL OUTDOOR PLANS INTO THE EVENING. THE GFS SHOWS LIKEWISE WITH SOME DECENT QPF STILL AT THE MIDNIGHT HOUR. OVERALL...QPF IS LIGHT FROM WPC AND ACTIVITY SHOULD BE BRIEF AND PERHAPS MORE SHOWERY THAN THUNDERY.OUR LAST SOUNDING WAS DRY ALOFT...BUT WITH MID AND UPPER LEVEL MOISTURE ON APPROACH POOLING AHEAD OF THE FRONT...THE UPPER LEVELS SHOULD BE THINNING BACK TO DRIER SOONER THAN THE REMAINING LOW LEVEL MOISTURE ALONG THE OLD FRONT. THE SPC HAS A GENERAL LINE FAR TO OUR NORTH RIGHT AHEAD OF THE NEW COLD FRONT SEEN WELL WITH 50 DEW POINTS FROM KN INTO N MO. THIS BOUNDARY WILL MAKE FOR A LATE SEPTEMBER FALL FEEL FOR THE WEEKEND WITH A NICE CHANGE OF SEASON EARLY. HOWEVER...WE COULD USE ANY AND ALL RAINFALL AS THIS FRONTAL PASSAGE WILL BRING BACK A DRY PATTERN ALONG WITH THE COOLER AIR INTO EARLY NEXT WEEK. BY THEN...THE GULF OPENS UP A BIT WITH SOME MOISTURE AND GOOD LATE SUMMER HEATING TO RETURN BY MID AND THROUGH LATE WEEK. /24/ .PRELIMINARY POINT TEMPS/POPS... SHV 94 68 84 57 / 30 50 10 0 MLU 92 66 82 53 / 20 60 10 0 DEQ 90 60 81 52 / 40 20 0 0 TXK 92 63 81 54 / 30 20 0 0 ELD 91 62 79 52 / 30 40 0 0 TYR 93 67 83 59 / 30 50 10 0 GGG 93 67 83 57 / 30 50 10 0 LFK 92 71 87 58 / 30 50 10 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS BUFFALO NY
736 AM EDT FRI SEP 11 2015 .SYNOPSIS... HIGH PRESSURE ACROSS THE REGION WILL BRING ONE MORE DRY DAY BEFORE EXITING INTO NEW ENGLAND. THEN A SLOW MOVING UPPER LEVEL LOW WILL MOVE INTO THE AREA TONIGHT AND SATURDAY WITH PERIODS OF RAIN DEVELOPING AND COOLER TEMPERATURES. A FEW SHOWERS WILL LINGER INTO SUNDAY WITH COOL AND CLOUDY CONDITIONS THEN HIGH PRESSURE WILL RETURN EARLY NEXT WEEK ALONG WITH SLOWLY WARMING TEMPERATURES. && .NEAR TERM /THROUGH TONIGHT/... AT 700 AM...SKIES WERE CLEAR ACROSS THE REGION WITH A NARROW RIDGE OF HIGH PRESSURE ACROSS WESTERN NEW YORK BETWEEN A DEPARTING COASTAL LOW AND AN UPPER LEVEL LOW ACROSS THE UPPER LAKES. THE MORNING WILL START OFF COOL...WITH SOME FOG ACROSS THE SOUTHERN TIER VALLEYS AND EASTERN LAKE ONTARIO REGIONS. THIS SHOULD DISSIPATE BY MID-MORNING. HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR WEATHER FOR MOST OF THE DAY...WITH TEMPERATURES SIMILAR TO MAYBE A DEGREE OR TWO WARMER THAN YESTERDAY. THE SURFACE HIGH WILL GRADUALLY GIVE-WAY TO AN UPPER LEVEL TROUGH WHICH IS FORECAST TO DIG ACROSS THE GREAT LAKES REGION. 06Z RUNS AND THE HRRR HAVE TRENDED A BIT SLOWER...WITH THE FORECAST UPDATE REFLECTING THIS SLIGHTLY SLOWER TIMING WHICH KEEPS OUR CWA DRY THROUGH LATE THIS AFTERNOON. RAIN WILL CONTINUE TO MOVE IN FROM WEST TO EAST AS THE 500 MB TROUGH GRADUALLY DEEPENS ACROSS THE LOWER LAKES. MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT...WITH BUFKIT SHOWING SIGNIFICANT LIFT IN THE MID-LEVELS SUGGESTING LARGE-SCALE SYNOPTIC FORCING WITH THE TROUGH. THIS CONTINUES TO SUPPORT CATEGORICAL POPS IN THE WESTERN HALF OF THE CWA TONIGHT. HIGH RESOLUTION GUIDANCE ALSO SUGGESTS SOME UPSLOPE ENHANCEMENT ACROSS WESTERN PORTIONS OF THE SOUTHERN TIER WHICH DOES SEEM REASONABLE GIVEN THE NORTHERLY FLOW. THIS WILL NOT IMPACT POPS...BUT THIS WILL BE REFLECTED IN QPFS OF GREATER THAN A HALF INCH THROUGH SATURDAY MORNING IN THESE AREAS. OTHERWISE...GRADUALLY COOLER AIR WILL ADVECT INTO THE REGION WITH THE TROUGH AND PRECIPITATION. WILL FAVOR MODEL RAW TEMPERATURE GUIDANCE OVER BIAS CORRECTED SINCE THERE IS NOT LIKELY TO BE MUCH RADIATIONAL COOLING OUTSIDE OF THE EASTERN LAKE ONTARIO REGION. THIS WILL RESULT IN UNIFORM LOWS IN THE 50S. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... THERE WILL BE A BAND OF RAIN ACROSS WESTERN NEW YORK ON SATURDAY MORNING WITH A REGION OF BAROCLINICITY AND BOUNDARY LAYER CONVERGENCE ACROSS WESTERN NEW YORK. THIS RAIN WILL CONTINUE TO SHIFT EASTWARD THROUGH THE DAY WITH THE HEAVIEST RAIN EXPECTED TO BE ACROSS THE SOUTHERN TIER TO CENTRAL NEW YORK...STORM TOTALS RANGING FROM A QUARTER TO A HALF INCH ACROSS WESTERN NY AND MORE THAN AN INCH OVER THE FINGER LAKES TO CENTRAL NY. TEMPERATURES WILL BE QUITE COOL ON SATURDAY AS NORTHERLY WINDS HOLD THE MAX TEMPS TO THE UPPER 50S TO LOWER 60S ACROSS THE HIGHLANDS OF THE SOUTHERN TIER AND TUG HILL PLATEAU...WITH LOWER TO MID 60S ACROSS THE LAKE PLAINS. DURING SATURDAY NIGHT...THE STEADIER RAIN WILL GIVE WAY TO OCCASIONAL SHOWERS AS THE FRONT/BAROCLINIC ZONE MOVES EAST AND THE INFLUENCE OF COOLER AIR ALOFT TAKES OVER. ON SUNDAY...THE CLOSED 500MB5 LOW WILL GRADUALLY PUSH ACROSS OUR FORECAST AREA. WHILE THE STRONGER DYNAMICS FROM THIS SYSTEM WILL BE NORTH AND EAST OF OUR FORECAST AREA...WE WILL STILL EXPERIENCE SOME SHOWERS UNDER THE UNSTABLE COLD CORE OF THIS SYSTEM. MOST OF THESE SHOWERS WILL BE DURING THE FIRST HALF OF THE DAY. HIGH TEMPERATURES ACROSS THE REGION WILL BE IN THE UPPER 50S TO MID 60S...SIMILAR TO TEMPERATURES ON SATURDAY. && .LONG TERM /MONDAY THROUGH THURSDAY/... THIS PERIOD WILL FEATURE A RETURN TO FAIR DRY WEATHER WITH DAY TO DAY WARMING SENDING TEMPERATURES BACK ABOVE NORMAL. THE UPPER LEVEL STORM SYSTEM THAT WILL BE RESPONSIBLE FOR THE INCLEMENT WEEKEND WEATHER WILL BE EXITING ACROSS THE ST LAWRENCE VALLEY AND QUEBEC ON MONDAY...WHILE SIGNIFICANT RIDGING WILL START TO BUILD ACROSS THE LOWER GREAT LAKES. THIS WILL RESULT IN A RETURN TO AT LEAST PARTIAL SUNSHINE FOR MONDAY WITH THE MERCURY RETURNING TO THE 70S. THE RIDGE WILL AMPLIFY OVER THE LOWER GREAT LAKES TUESDAY INTO THURSDAY WITH STRONG SFC HIGH PRESSURE BEING CENTERED OVER THE MID ATLANTIC REGION. THIS WILL GUARANTEE FAIR DRY WEATHER WITH THE MERCURY CLIMBING BACK INTO THE 80S FOR MANY AREAS BY MID WEEK. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AT DAYBREAK THERE IS PATCHY FOG ACROSS THE REGION IMPACTING THE ART/JHW TERMINALS. THIS SHOULD DISSIPATE QUICKLY AT ART AND BY MID-MORNING AT JHW. AFTER THIS...HIGH PRESSURE WILL PROVIDE DRY WEATHER AND VFR CONDITIONS THROUGH LATE AFTERNOON. AN UPPER TROUGH WILL APPROACH AND GRADUALLY BRING RAIN INTO THE REGION OVERNIGHT. FLIGHT CONDITIONS SHOULD GRADUALLY LOWER FROM WEST TO EAST...GENERALLY TO MVFR AS THE RAIN MOVES IN. THE EXCEPTION MAY BE JHW WHERE THE UPSLOPE NORTHERLY FLOW WILL INCREASE LOW MOISTURE AND POSSIBLY CAUSE A LOWER IFR CLOUD DECK. OUTLOOK... SATURDAY...AREAS OF MVFR/IFR WITH PERIODS OF RAIN. SUNDAY...AREAS OF MVFR WITH SCATTERED SHOWERS. MONDAY AND TUESDAY...VFR. && .MARINE... HIGH PRESSURE WILL REMAIN ACROSS THE REGION TODAY WITH LIGHT TO MODEST WINDS AND MINIMAL WAVES. WEAK LOW PRESSURE WILL BRING A BRIEF UPTICK IN WINDS THIS WEEKEND BUT THIS NORTHERLY FLOW STILL LOOKS TO BE A BIT SHY OF SMALL CRAFT CRITERIA. THEN HIGH PRESSURE WILL BUILD BACK ACROSS THE REGION EARLY NEXT WEEK. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. && $$ SYNOPSIS...APFFEL NEAR TERM...APFFEL SHORT TERM...WCH LONG TERM...RSH AVIATION...APFFEL MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
706 AM EDT FRI SEP 11 2015 .SYNOPSIS... A COLD FRONT OVER THE CENTRAL GREAT LAKES WILL MOVE EAST ACROSS THE AREA TODAY. A STRONG UPPER AIR DISTURBANCE WILL DROP ACROSS THE GREAT LAKES THIS WEEKEND. HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... RECENT SATELLITE IMAGERY SHOWS WARMING CLOUD TOPS IN THE BAROCLINIC LEAF OVER ILLINOIS AND MISSOURI WITH LIGHTNING ACTIVITY ALSO DECREASING. THE REGIONAL RADAR MOSAIC ALSO SHOWS A WEAKENING TREND IN THE SHOWERS OVER ILLINOIS TOO. THE HRRR HAS PICKED UP ON THESE TRENDS AND IS SLOWER IN MOVING THE PRECIPITATION INTO NORTHERN OHIO. WE WILL DELAY THE ONSET OF SHOWERS IN THE FORECAST AREA TODAY TO REFLECT THIS CHANGE. PREVIOUS DISCUSSION: UNSETTLED WEATHER IS EXPECTED TO DEVELOP ACROSS THE REGION TODAY AS A COLD FRONT CURRENTLY LOCATED FROM NORTHERN LOWER MICHIGAN TO ILLINOIS MOVES ACROSS THE REGION THIS AFTERNOON. SHOWERS ARE EXPECTED TO DEVELOP OVER NORTHWEST OHIO LATE THIS MORNING AND PROGRESS TO NORTHEAST OHIO BY THIS EVENING. MOST OF THE SHOWERS ARE EXPECTED TO BE POST FRONTAL. HAVE USED THE HRRR FOR TIMING OF THE PRECIPITATION. LATE MORNING SHOWERS WILL LIMIT MAX TEMPERATURES NEAR TOL WHILE EASTERN COUNTIES WILL BE RAINFREE MOST OF THE DAY WHICH WILL ALLOW TEMPERATURES TO CLIMB INTO THE MID 70S. A MODEST AMOUNT OF INSTABILITY IS EXPECTED WITH CAPE EXPECTED TO INCREASE TO AROUND 500 J/KG. WILL INITIALLY MENTION SHOWERS TODAY AND THEN ADD THUNDERSTORMS FOR THE AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SOMEWHAT SHOWERY FOR THE FIRST HALF OF THE WEEKEND AND THEN GRADUAL IMPROVEMENT SUNDAY AND ESPECIALLY ON MONDAY. LITTLE CHANGE IN EXPECTATION FOR THE WEEKEND WEATHER AS A POTENT SHORT WAVE DISTURBANCES AMPLIFIES THE LONG WAVE TROUGH OVER THE REGION SATURDAY. THE TROUGH WILL THEN SLOWLY LIFT NORTHEAST AWAY FROM THE REGION SUNDAY AND MONDAY. THE COLD AIR ALOFT WITH THE APPROACHING TROUGH IN COMBINATION WITH RATHER WARM LAKE ERIE NEAR 24C WILL CREATE AN UNSTABLE BOUNDARY LAYER OVER AND DOWNWIND OF THE LAKE. CONSEQUENTLY, INSTABILITY SHOWERS WITH PERHAPS SOME THUNDER ARE LIKELY ESPECIALLY SATURDAY AND SATURDAY NIGHT EAST OF KCLE. CAPE OVER LAKE ERIE MAY BE AS HIGH AS 500-1000 J/KG WHICH COULD PRODUCE MODERATE TO BRIEFLY HEAVY SHOWERS. THE DOWNSCALED NAM DEPICTS CONVECTIVE DEVELOPMENT OVER AND SOUTHEAST OF THE LAKE OVER THE EASTERN HALF OF THE FORECAST AREA MAINLY ON SATURDAY AND THIS SEEMS REASONABLE. AS THE UPPER SYSTEM BEGINS TO LIFT AWAY AND INSTABILITY AND MOISTURE DECREASE ON SUNDAY AND SUNDAY NIGHT, SHOWERS WILL BECOME MORE SCATTERED AND CONFINED MAINLY TO THE SNOWBELT COUNTIES EAST OF KCLE. HAVE REDUCED POP BELOW MENTIONABLE VALUES ON MONDAY GIVEN THE EXPECTED RIDGING AND DRY LOW LEVEL WESTERLY FLOW OVER THE REGION ALONG WITH THE WARMING STABILIZING FLOW. THE WEEKEND WILL BE RATHER COOL AND ABOUT 10 DEGREES BELOW NORMAL AND BE MAINLY IN THE MID TO UPPER 60S. IF PRECIPITATION IS MORE CONSTANT ALONG WITH CLOUD COVER, READINGS MAY ON REACH 60 IN THE HIGHER TERRAIN OF GEAUGA COUNTY AND INLAND NORTHWEST PENNSYLVANIA. MODERATING CONDITIONS ARE EXPECTED MONDAY. && .LONG TERM /TUESDAY THROUGH THURSDAY/... THE FORECAST FOR TUE THRU THU STILL LOOKS IN LINE WITH HIGH PRESSURE...DRY WX AND WARMING TEMPS. THE MODELS SHOW MOISTURE WITH A WEAK S/W SPREADING BACK INTO THE AREA THU INTO THU NIGHT SO WILL CONTINUE TO SHOW INCREASING CHC POPS WEST TO EAST FOR THEN. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... ANY PATCHY FOG SHOULD DISSIPATE BY 13Z. RAIN AND EVENTUAL MVFR CONDITIONS SHOULD RAPIDLY DEVELOP WEST TO EAST FROM ABOUT 16Z AT TOL AND FDY TO AROUND 21Z FOR YNG AND ERI. MOST OF THE RAIN SHOULD END IN THE WEST AROUND 00Z AND CIGS MAY IMPROVE FOR A WHILE BEFORE LOWERING AGAIN LATER IN THE NIGHT. THE REST OF THE AREA SHOULD SEE MAINLY MVFR CONTINUE THE REST OF THE NIGHT WITH SCT SHRA. LIGHT WINDS WILL BECOME NORTH FROM 10 TO 15 KNOTS LATER TODAY INTO TONIGHT. OUTLOOK...NON VFR CONTINUING THROUGH THE WEEKEND...ESPECIALLY FOR NE OH AND NW PA. && .MARINE... NORTH WINDS BEHIND A COLD FRONT WILL INCREASE THIS AFTERNOON AND EVENING WITH SCA CONDITIONS DEVELOPING BY THE END OF THE DAY. WINDS ARE EXPECTED TO DECREASE SOME ON SAT BUT MAY NOT BE ENOUGH TO SEE WAVES FALL BELOW 4 FEET SO THE SCA MAY NEED TO CONTINUE INTO SUN. IF THE HIGH MOVING UP THE OH VALLEY SUN AND SUN NIGHT STAYS FAR ENOUGH TO THE SOUTH WINDS WILL BACK TO SW SUN NIGHT INTO MON BUT COULD STAY JUST STRONG ENOUGH FOR MARGINAL SCA WAVES TO HANG ON FOR THE EAST PART OF THE LAKE...BUT FOR NOW WILL MAINTAIN CONTINUITY WITH SUB SCA CONDITIONS. WINDS CONTINUE TO BACK TO SOUTH AND LIGHTEN MON NIGHT AND TUE AS THE HIGH DRIFTS OVER CENTRAL PA. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...LAPLANTE NEAR TERM...LAPLANTE SHORT TERM...LAPLANTE LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
635 AM EDT FRI SEP 11 2015 .SYNOPSIS... A COLD FRONT OVER THE CENTRAL GREAT LAKES WILL MOVE EAST ACROSS THE AREA TODAY. A STRONG UPPER AIR DISTURBANCE WILL DROP ACROSS THE GREAT LAKES THIS WEEKEND. HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE WEST EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... RECENT SATELLITE IMAGERY SHOWS WARMING CLOUD TOPS IN THE BAROCLINIC LEAF OVER ILLINOIS AND MISSOURI WITH LIGHTNING ACTIVITY ALSO DECREASING. THE REGIONAL RADAR MOSAIC ALSO SHOWS A WEAKENING TREND IN THE SHOWERS OVER ILLINOIS TOO. THE HRRR HAS PICKED UP ON THESE TRENDS AND IS SLOWER IN MOVING THE PRECIPITATION INTO NORTHERN OHIO. WE WILL DELAY THE ONSET OF SHOWERS IN THE FORECAST AREA TODAY TO REFLECT THIS CHANGE. PREVIOUS DISCUSSION: UNSETTLED WEATHER IS EXPECTED TO DEVELOP ACROSS THE REGION TODAY AS A COLD FRONT CURRENTLY LOCATED FROM NORTHERN LOWER MICHIGAN TO ILLINOIS MOVES ACROSS THE REGION THIS AFTERNOON. SHOWERS ARE EXPECTED TO DEVELOP OVER NORTHWEST OHIO LATE THIS MORNING AND PROGRESS TO NORTHEAST OHIO BY THIS EVENING. MOST OF THE SHOWERS ARE EXPECTED TO BE POST FRONTAL. HAVE USED THE HRRR FOR TIMING OF THE PRECIPITATION. LATE MORNING SHOWERS WILL LIMIT MAX TEMPERATURES NEAR TOL WHILE EASTERN COUNTIES WILL BE RAINFREE MOST OF THE DAY WHICH WILL ALLOW TEMPERATURES TO CLIMB INTO THE MID 70S. A MODEST AMOUNT OF INSTABILITY IS EXPECTED WITH CAPE EXPECTED TO INCREASE TO AROUND 500 J/KG. WILL INITIALLY MENTION SHOWERS TODAY AND THEN ADD THUNDERSTORMS FOR THE AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SOMEWHAT SHOWERY FOR THE FIRST HALF OF THE WEEKEND AND THEN GRADUAL IMPROVEMENT SUNDAY AND ESPECIALLY ON MONDAY. LITTLE CHANGE IN EXPECTATION FOR THE WEEKEND WEATHER AS A POTENT SHORT WAVE DISTURBANCES AMPLIFIES THE LONG WAVE TROUGH OVER THE REGION SATURDAY. THE TROUGH WILL THEN SLOWLY LIFT NORTHEAST AWAY FROM THE REGION SUNDAY AND MONDAY. THE COLD AIR ALOFT WITH THE APPROACHING TROUGH IN COMBINATION WITH RATHER WARM LAKE ERIE NEAR 24C WILL CREATE AN UNSTABLE BOUNDARY LAYER OVER AND DOWNWIND OF THE LAKE. CONSEQUENTLY, INSTABILITY SHOWERS WITH PERHAPS SOME THUNDER ARE LIKELY ESPECIALLY SATURDAY AND SATURDAY NIGHT EAST OF KCLE. CAPE OVER LAKE ERIE MAY BE AS HIGH AS 500-1000 J/KG WHICH COULD PRODUCE MODERATE TO BRIEFLY HEAVY SHOWERS. THE DOWNSCALED NAM DEPICTS CONVECTIVE DEVELOPMENT OVER AND SOUTHEAST OF THE LAKE OVER THE EASTERN HALF OF THE FORECAST AREA MAINLY ON SATURDAY AND THIS SEEMS REASONABLE. AS THE UPPER SYSTEM BEGINS TO LIFT AWAY AND INSTABILITY AND MOISTURE DECREASE ON SUNDAY AND SUNDAY NIGHT, SHOWERS WILL BECOME MORE SCATTERED AND CONFINED MAINLY TO THE SNOWBELT COUNTIES EAST OF KCLE. HAVE REDUCED POP BELOW MENTIONABLE VALUES ON MONDAY GIVEN THE EXPECTED RIDGING AND DRY LOW LEVEL WESTERLY FLOW OVER THE REGION ALONG WITH THE WARMING STABILIZING FLOW. THE WEEKEND WILL BE RATHER COOL AND ABOUT 10 DEGREES BELOW NORMAL AND BE MAINLY IN THE MID TO UPPER 60S. IF PRECIPITATION IS MORE CONSTANT ALONG WITH CLOUD COVER, READINGS MAY ON REACH 60 IN THE HIGHER TERRAIN OF GEAUGA COUNTY AND INLAND NORTHWEST PENNSYLVANIA. MODERATING CONDITIONS ARE EXPECTED MONDAY. && .LONG TERM /TUESDAY THROUGH THURSDAY/... THE FORECAST FOR TUE THRU THU STILL LOOKS IN LINE WITH HIGH PRESSURE...DRY WX AND WARMING TEMPS. THE MODELS SHOW MOISTURE WITH A WEAK S/W SPREADING BACK INTO THE AREA THU INTO THU NIGHT SO WILL CONTINUE TO SHOW INCREASING CHC POPS WEST TO EAST FOR THEN. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... SOME PATCHY MVFR FOG SHOULD DEVELOP AROUND CAK AND YNG TOWARD DAYBREAK...OTHERWISE VFR WILL PREVAIL INTO THE DAYLIGHT HOURS. RAIN AND EVENTUAL MVFR CONDITIONS SHOULD RAPIDLY DEVELOP WEST TO EAST FROM 15Z AROUND TOL AND FDY TO 19 TO 21Z FOR YNG AND ERI. MOST OF THE RAIN SHOULD END IN THE WEST AROUND 00Z AND CIGS MAY IMPROVE FOR A WHILE BEFORE LOWERING AGAIN LATER IN THE NIGHT. LIGHT WINDS WILL BECOME NORTH FROM 10 TO 15 KNOTS LATER TODAY INTO TONIGHT. OUTLOOK...NON VFR CONTINUING THROUGH THE WEEKEND...ESPECIALLY FOR NE OH AND NW PA. && .MARINE... NORTH WINDS BEHIND A COLD FRONT WILL INCREASE THIS AFTERNOON AND EVENING WITH SCA CONDITIONS DEVELOPING BY THE END OF THE DAY. WINDS ARE EXPECTED TO DECREASE SOME ON SAT BUT MAY NOT BE ENOUGH TO SEE WAVES FALL BELOW 4 FEET SO THE SCA MAY NEED TO CONTINUE INTO SUN. IF THE HIGH MOVING UP THE OH VALLEY SUN AND SUN NIGHT STAYS FAR ENOUGH TO THE SOUTH WINDS WILL BACK TO SW SUN NIGHT INTO MON BUT COULD STAY JUST STRONG ENOUGH FOR MARGINAL SCA WAVES TO HANG ON FOR THE EAST PART OF THE LAKE...BUT FOR NOW WILL MAINTAIN CONTINUITY WITH SUB SCA CONDITIONS. WINDS CONTINUE TO BACK TO SOUTH AND LIGHTEN MON NIGHT AND TUE AS THE HIGH DRIFTS OVER CENTRAL PA. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...LAPLANTE NEAR TERM...LAPLANTE SHORT TERM...LAPLANTE LONG TERM...ADAMS AVIATION...ADAMS MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1054 AM CDT FRI SEP 11 2015 .UPDATE... MORNING FORECAST UPDATE. && .DISCUSSION... RADAR TRENDS SHOW MORE SCATTERED SHOWER/THUNDERSTORM ACTIVITY DEVELOPING NORTH OF HOUSTON AND SOUTH OF A COLLEGE STATION TO HUNTSVILLE LINE. STORM MOTIONS ARE MORE FROM THE NORTH WITH THIS ACTIVITY AND LIKELY ASSOCIATED WITH THE APPROACHING TROUGH AXIS ON WATER VAPOR IMAGERY. THERE ALSO LOOKS TO BE SOME PUSH SOUTHWARD OF A STALLED FRONT FROM YESTERDAY OVER C AND E TX. THE STRONGER COLD FRONT WHICH SHOULD BRING MUCH DRIER AND SOME COOLER CONDITIONS FOR THE WEEKEND WAS STILL LOCATED BACK OVER OKLAHOMA AND TX PANHANDLE. THIS FRONT WILL PUSH THROUGH TONIGHT/SATURDAY MORNING WITH DRIER AIR LAGGING BEHIND. RECENT TRENDS WITH THE HRRR SEEM NOT TO BE PICKING UP ON NEW DEVELOPMENT WELL SO WILL AT LEAST LEAVE SOME THUNDERSTORM CHANCES IN THE FORECAST FOR THE AFTERNOON WITH THE TROUGH AXIS PUSHING THROUGH. DO EXPECT LOWER CHANCES THIS AFTERNOON AND THINK MOST OF THE ACTIVITY WILL BE DONE IN TIME FOR THE EVENING RUSH HOUR. MAIN CHANGES TO THE FORECAST WERE TO UPDATE RAIN CHANCES AND THEN TEMPERATURE TRENDS WITH RAIN COOLED AIRMASS WHICH WITH CLOUD COVER SHOULD NOT HEAT UP MUCH. 39 && .PREV DISCUSSION... /ISSUED / DISCUSSION... SEE THE 12Z AVIATION DISCUSSION BELOW. 40 AVIATION... PERIODS OF SHOWERS AND THUNDERSTORMS WILL AFFECT THE BIG METRO AIRPORTS AND TERMINALS SOUTH TO THE COAST THROUGH AT LEAST 14Z. THE HIGH RESOLUTION MODELS ARE THEN FORECASTING A BREAK TO DEVELOP...ALTHOUGH WITH DAYTIME HEATING MORE SHOWERS WILL LIKELY DEVELOP AFTER 17Z. NOT A HIGH CONFIDENCE FORECAST DURING THE AFTERNOON...HOWEVER FELT THAT THE ARW AND HRRR MODELS WERE DOING WELL SO FAR THIS MORNING AND BOTH LOWER CHANCES THIS AFTERNOON. THE FRONT WILL BEGIN WORKING ITS WAY INTO THE AREA LATER TONIGHT. A PREFRONTAL FRONT WILL PUSH INTO KIAH AND KHOU. THE SREF FOG PROBABILITIES REACH OVER 30 PERCENT FOR KSGR AND KLBX FOR GENERALLY THE OVERNIGHT PERIOD AFTER 06Z TONIGHT. 40 PREV DISCUSSION... /ISSUED 408 AM CDT FRI SEP 11 2015/ DISCUSSION... CONVECTION STARTING A LITTLE EARLIER THIS MORNING AS A WEAK DISTURBANCE OVER NORTHERN MEXICO APPROACHES SOUTHEAST TEXAS. THE FLOW ALOFT REMAINS DIVERGENT AND PW VALUES REMAIN BETWEEN 2.10 AND 2.30 INCHES. RAP IS DOING A GOOD JOB THIS MORNING AND WILL LEAN TOWARD A GFS/ECMWF RAP BLEND. WILL CARRY LIKELY POPS TODAY WITH CONVECTION TRENDING TOWARD LESS COVERAGE OVER THE CENTRAL/COASTAL ZONES BY MID AFTN. WITH PW VALUES AOA 2.00 INCHES...THERE IS SOME POTENTIAL FOR LOCALLY HEAVY RAIN. STORM MOTION SHOULD BE BETWEEN 10-15 KNOTS BUT THERE IS A WEAK SFC TROUGH ALIGNED FROM KIAH TO KLRD AND THIS FEATURE COULD FOCUS SOME TRAINING THIS MORNING. AT 3 AM...A COLD FRONT WAS LOCATED FROM ABOUT JOPLIN MO TO ARDMORE OK TO CHILDRESS. THE FRONT WILL MOVE SLOWLY SOUTH TODAY AND TONIGHT AND CROSS SE TX LATE TONIGHT. THE FRONT MIGHT TRIGGER ADDITIONAL SHRA BUT MOST OF THE MOISTURE IS SHUNTED EAST AHEAD OF THE FRONT SO NOT EXPECTING MUCH MORE THAN ISOLATED TO WIDELY SCATTERED SHOWERS WITH THE FROPA. DRIER AIR WILL SLOWLY WORK INTO SE TX ON SATURDAY AND DEW PTS WILL LOWER INTO THE 50S NORTH OF I-10 DURING THE AFTN BUT REMAIN IN THE LOWER 70S ALONG THE COAST. DRIER AIR WILL COVER ALL OF SE TX SAT NITE THROUGH MONDAY. A WARM START TO SATURDAY COUPLED WITH THE DRIER AIR SHOULD YIELD SOME WARM TEMPS BUT LOWER 850 TEMPS ON SUNDAY SHOULD PRODUCE SLIGHTLY COOLER MAX TEMPS ON SUNDAY. A WEAK COASTAL TROUGH WILL DEVELOP OFF THE MEXICAN COAST MONDAY NIGHT AND THIS FEATURE WILL EXTEND NORTH ALONG THE TEXAS COAST. SYSTEM SHOULD REMAIN SOMEWHAT DISORGANIZED AS UPPER LEVEL WINDS OF 30 KNOTS SHOULD PROVIDE ENOUGH SHEAR TO INHIBIT DEVELOPMENT. THE TROUGH WILL FOCUS HIGHER MOISTURE ALONG THE TEXAS COAST ON TUES/WED. NOT SURE HOW FAR INLAND MOISTURE WILL GET AND HAVE TAPERED POPS RATHER SIGNIFICANTLY FROM KGLS TO KCLL. THE ELONGATED SURFACE TROUGH WEAKENS AND WILL MOVE INLAND WEDNESDAY NIGHT. RAIN CHANCES SHOULD DECREASE AGAIN THU/FRI AS UPPER LEVEL RIDGING EXPANDS OVER NORTHERN MEXICO AND IMPINGES ON SE TX. 43 MARINE... EXPECT ANOTHER PERIOD OF SHOWERS AND THUNDERSTORMS OVER THE COASTAL WATERS TODAY AND A FRONTAL PASSAGE IS EXPECTED SATURDAY MORNING WITH OFFSHORE WINDS DEVELOPING BEHIND THE FRONT. THE MODELS DO NOT INCREASE WIND SPEEDS UNTIL SUNDAY WHEN AT LEAST CAUTION CONDITIONS ARE EXPECTED. A GRADUAL DECREASE IN WIND SPEEDS WILL THEN OCCUR ON MONDAY AND A MORE SOUTHEASTERLY FLOW IS EXPECTED TO DEVELOP MONDAY NIGHT AND TUESDAY. 40 CLIMATE... HOUSTON HOBBY AIRPORT RECEIVED 0.68 INCHES OF RAIN YESTERDAY. THAT BRINGS THE 2015 ANNUAL TOTAL TO 54.79 INCHES WHICH EXCEEDS THE 1981-2010 30 YEAR AVERAGE RAINFALL OF 54.65 INCHES. IN OTHER WORDS...HOBBY EXCEEDED THEIR NORMAL YEARLY RAINFALL IN JUST OVER NINE MONTHS. WITH THREE MONTHS TO GO...THE 2015 TOTAL WILL LIKELY GROW. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 89 73 88 62 86 / 50 30 10 10 0 HOUSTON (IAH) 85 73 88 63 83 / 70 30 20 10 0 GALVESTON (GLS) 82 76 84 74 84 / 70 50 30 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
640 AM CDT FRI SEP 11 2015 .DISCUSSION... SEE THE 12Z AVIATION DISCUSSION BELOW. 40 && .AVIATION... PERIODS OF SHOWERS AND THUNDERSTORMS WILL AFFECT THE BIG METRO AIRPORTS AND TERMINALS SOUTH TO THE COAST THROUGH AT LEAST 14Z. THE HIGH RESOLUTION MODELS ARE THEN FORECASTING A BREAK TO DEVELOP...ALTHOUGH WITH DAYTIME HEATING MORE SHOWERS WILL LIKELY DEVELOP AFTER 17Z. NOT A HIGH CONFIDENCE FORECAST DURING THE AFTERNOON...HOWEVER FELT THAT THE ARW AND HRRR MODELS WERE DOING WELL SO FAR THIS MORNING AND BOTH LOWER CHANCES THIS AFTERNOON. THE FRONT WILL BEGIN WORKING ITS WAY INTO THE AREA LATER TONIGHT. A PREFRONTAL FRONT WILL PUSH INTO KIAH AND KHOU. THE SREF FOG PROBABILITIES REACH OVER 30 PERCENT FOR KSGR AND KLBX FOR GENERALLY THE OVERNIGHT PERIOD AFTER 06Z TONIGHT. 40 && .PREV DISCUSSION... /ISSUED 408 AM CDT FRI SEP 11 2015/ DISCUSSION... CONVECTION STARTING A LITTLE EARLIER THIS MORNING AS A WEAK DISTURBANCE OVER NORTHERN MEXICO APPROACHES SOUTHEAST TEXAS. THE FLOW ALOFT REMAINS DIVERGENT AND PW VALUES REMAIN BETWEEN 2.10 AND 2.30 INCHES. RAP IS DOING A GOOD JOB THIS MORNING AND WILL LEAN TOWARD A GFS/ECMWF RAP BLEND. WILL CARRY LIKELY POPS TODAY WITH CONVECTION TRENDING TOWARD LESS COVERAGE OVER THE CENTRAL/COASTAL ZONES BY MID AFTN. WITH PW VALUES AOA 2.00 INCHES...THERE IS SOME POTENTIAL FOR LOCALLY HEAVY RAIN. STORM MOTION SHOULD BE BETWEEN 10-15 KNOTS BUT THERE IS A WEAK SFC TROUGH ALIGNED FROM KIAH TO KLRD AND THIS FEATURE COULD FOCUS SOME TRAINING THIS MORNING. AT 3 AM...A COLD FRONT WAS LOCATED FROM ABOUT JOPLIN MO TO ARDMORE OK TO CHILDRESS. THE FRONT WILL MOVE SLOWLY SOUTH TODAY AND TONIGHT AND CROSS SE TX LATE TONIGHT. THE FRONT MIGHT TRIGGER ADDITIONAL SHRA BUT MOST OF THE MOISTURE IS SHUNTED EAST AHEAD OF THE FRONT SO NOT EXPECTING MUCH MORE THAN ISOLATED TO WIDELY SCATTERED SHOWERS WITH THE FROPA. DRIER AIR WILL SLOWLY WORK INTO SE TX ON SATURDAY AND DEW PTS WILL LOWER INTO THE 50S NORTH OF I-10 DURING THE AFTN BUT REMAIN IN THE LOWER 70S ALONG THE COAST. DRIER AIR WILL COVER ALL OF SE TX SAT NITE THROUGH MONDAY. A WARM START TO SATURDAY COUPLED WITH THE DRIER AIR SHOULD YIELD SOME WARM TEMPS BUT LOWER 850 TEMPS ON SUNDAY SHOULD PRODUCE SLIGHTLY COOLER MAX TEMPS ON SUNDAY. A WEAK COASTAL TROUGH WILL DEVELOP OFF THE MEXICAN COAST MONDAY NIGHT AND THIS FEATURE WILL EXTEND NORTH ALONG THE TEXAS COAST. SYSTEM SHOULD REMAIN SOMEWHAT DISORGANIZED AS UPPER LEVEL WINDS OF 30 KNOTS SHOULD PROVIDE ENOUGH SHEAR TO INHIBIT DEVELOPMENT. THE TROUGH WILL FOCUS HIGHER MOISTURE ALONG THE TEXAS COAST ON TUES/WED. NOT SURE HOW FAR INLAND MOISTURE WILL GET AND HAVE TAPERED POPS RATHER SIGNIFICANTLY FROM KGLS TO KCLL. THE ELONGATED SURFACE TROUGH WEAKENS AND WILL MOVE INLAND WEDNESDAY NIGHT. RAIN CHANCES SHOULD DECREASE AGAIN THU/FRI AS UPPER LEVEL RIDGING EXPANDS OVER NORTHERN MEXICO AND IMPINGES ON SE TX. 43 MARINE... EXPECT ANOTHER PERIOD OF SHOWERS AND THUNDERSTORMS OVER THE COASTAL WATERS TODAY AND A FRONTAL PASSAGE IS EXPECTED SATURDAY MORNING WITH OFFSHORE WINDS DEVELOPING BEHIND THE FRONT. THE MODELS DO NOT INCREASE WIND SPEEDS UNTIL SUNDAY WHEN AT LEAST CAUTION CONDITIONS ARE EXPECTED. A GRADUAL DECREASE IN WIND SPEEDS WILL THEN OCCUR ON MONDAY AND A MORE SOUTHEASTERLY FLOW IS EXPECTED TO DEVELOP MONDAY NIGHT AND TUESDAY. 40 CLIMATE... HOUSTON HOBBY AIRPORT RECEIVED 0.68 INCHES OF RAIN YESTERDAY. THAT BRINGS THE 2015 ANNUAL TOTAL TO 54.79 INCHES WHICH EXCEEDS THE 1981-2010 30 YEAR AVERAGE RAINFALL OF 54.65 INCHES. IN OTHER WORDS...HOBBY EXCEEDED THEIR NORMAL YEARLY RAINFALL IN JUST OVER NINE MONTHS. WITH THREE MONTHS TO GO...THE 2015 TOTAL WILL LIKELY GROW. 43 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 89 73 88 62 86 / 50 30 10 10 0 HOUSTON (IAH) 87 73 88 63 83 / 70 30 20 10 0 GALVESTON (GLS) 84 76 84 74 84 / 60 50 30 10 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...43 AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
141 PM MST FRI SEP 11 2015 .SYNOPSIS... SOMEWHAT DRIER AIR WILL REMAIN IN PLACE ACROSS THE REGION THROUGH THE FIRST HALF OF THE WEEKEND...AS NORTHERLY FLOW TAKES HOLD ACROSS THE AREA. A TROUGH WILL SLOWLY MOVE THROUGH THE DESERT SOUTHWEST SUNDAY AND MONDAY...RESULTING IN AN INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS. DRIER AIR WILL RETURN BY THE MIDDLE OF NEXT WEEK WITH MINIMAL STORM CHANCES ALONG WITH BELOW NORMAL TEMPERATURES. && .DISCUSSION... EARLY AFTERNOON WATER VAPOR IMAGERY CONTINUES TO REVEAL DRY NORTHERLY FLOW ACROSS PORTIONS OF ARIZONA...WITH DEEPER MOISTURE PRIMARILY CONFINED TO AREAS SOUTH OF THE INTERNATIONAL BORDER. A FEW SHOWERS HAVE DEVELOPED SOUTH OF YUMA AND PIMA COUNTIES /AND ALONG THE AZ NM BORDER/ THIS AFTERNOON BUT HAVE BEEN SLOW TO MOVE OR MAKE ANY PROGRESS TOWARD THE FORECAST AREA. MEANWHILE ACROSS THE DESERTS...TEMPERATURES HAVE REBOUNDED INTO THE MID 90S AS OF 20Z. ALL OF THESE STORMS HAVE BEEN ACCOUNTED FOR BY THE PAST SEVERAL RUNS OF THE HRRR AS WELL AS THE NCAR ENSEMBLE...LEADING TO A MODERATELY HIGH DEGREE OF CONFIDENCE FOR THIS EVENING. NOT MUCH IN THE WAY OF INSTABILITY ACROSS THE LOWER DESERTS THIS EVENING...LIKEWISE THERE AREN`T ANY DISCERNIBLE UPPER LEVEL TROUGHS HEADING TOWARD ARIZONA. ALL GLOBAL AND HI-RES GUIDANCE INDICATES THAT ANY STORM DEVELOPMENT WILL BE SHORT LIVED AND PRIMARILY FOCUSED ACROSS SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA...THUS POPS WILL REMAIN AT OR BELOW 10 PERCENT AROUND THE PHOENIX AREA WITH ONLY SLIGHTLY HIGHER VALUES AROUND YUMA AND EL CENTRO. TOMORROW WILL SEE A VERY SIMILAR SETUP WITH MOISTURE MAINLY ALONG AND WEST OF THE COLORADO RIVER. MODELS BARELY INDICATE 100-250 J/KG MLCAPE AROUND YUMA AND POINTS WEST ALONG WITH FAIRLY WARM 500MB TEMPS /-5C/. HARD TO IMAGINE MUCH IN THE WAY OF STORMS ANYWHERE ON SATURDAY BUT MUCH LIKE TODAY...I WOULD EXPECT STORMS SOUTH OF THE INTERNATIONAL BORDER AND THERE`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
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1135 AM MDT FRI SEP 11 2015 .UPDATE... ISSUED AT 1005 AM MDT FRI SEP 11 2015 UPDATED TO DIMINISH PRECIPITATION CHANCES ACROSS THE AREA WITH LATEST RUNS HIGHER RESOLUTION HRRR AND RAP KEEPING ISOLATED POPS OVER AND NEAR THE EASTERN AND SOUTHWESTERN MTS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 301 AM MDT FRI SEP 11 2015 ...COOL START TO THE WEEKEND... CURRENTLY...LOW CLOUD DECK IS SPREADING OVER THE PLAINS WITH CIGS FROM 15 TO 2500 FT AGL. WINDS GENERALLY FROM THE NE BUT NOT PARTICULARLY STRONG. RADAR HAS BEEN PRETTY QUIET OVERNIGHT...BUT A FEW CONVECTIVE CELLS HAVE MATERIALIZED OVER SRN BACA COUNTY THIS MORNING. MAIN QUESTION TODAY IS HOW EXTENSIVE AND PERSISTENT THE LOW CLOUD DECK WILL BE. MODELS NOT TOO HELPFUL AS THERE IS A WIDE RANGE OF SOLUTIONS...FROM THE 00Z NAM WHICH KEPT MOST OF THE PLAINS UNDER LOW CIGS FOR MOST OF THE DAY...TO SOME OF THE HYR RES MODELS SUCH AS THE HRRR...WHICH APPEARS TO BREAK OUT MUCH OF THE PLAINS BY LATE MORNING. LATEST 06Z NAM SOLUTION HAS BACKED OFF A BIT ON THE EXTENT OF CLOUDS THIS MORN. MODEL SOUNDINGS SHOW A MOIST LAYER THAT IS NOT TERRIBLY DEEP...WITH TOPS FROM 7-9K FEET MSL. CURRENT IR SAT IMAGES SHOW A RAGGED STRETCH OF LOW CIGS ACROSS THE PLAINS. THESE FACTORS POINT TOWARDS A BIT LESS CLOUDINESS THIS AFTERNOON. HOWEVER...THE 1026 MB SFC HIGH OVER THE DAKOTAS WILL CONTINUE BUILDING SWD TODAY...KEEPING A FAIRLY STRONG ERLY GRADIENT INTACT THROUGH THIS EVE. MODERATE S-SE WINDS SHOULD PERSIST THROUGH THIS AFTERNOON...WHICH TYPICALLY IS A RECIPE FOR PERSISTENT LOW CIGS AT KCOS. NAM MOS GUIDANCE BACKS THIS SCENARIO UP. SO...WILL PLAY THE MIDDLE ROAD AND KEEP CLOUDS FOR MOST OF THE PLAINS THROUGH THE MORNING HOURS...WITH SOME BREAKS EXPECTED BY LATE MORNING OR EARLY AFTERNOON. KCOS WILL BE THE TRICKIEST CALL SINCE IT MAY BE ON THE EDGE OF THE CLOUD DECK FOR A WHILE THIS AFTERNOON. AT ANY RATE...CLOUDS WILL KEEP TEMPS CONSIDERABLY LOWER TODAY...WITH HIGHS STRUGGLING TO GET INTO THE LOWER 70S MOST SPOTS. A FEW SPOTTY SHOWERS ALSO LIKELY WHERE THE CLOUD DECK IS THICKEST...MAINLY OVER THE BETTER UPSLOPE REGIONS ALONG THE ERN MTS AND ACROSS THE RATON MESA. A COUPLE STORMS ALSO POSSIBLE LATER THIS AFTERNOON ACROSS OR NR THE HYR TRRN...BUT NOT EXPECTING A LOT OF HEAVY CONVECTION. AREAS W OF THE SRN FRONT RANGE SHOULD STAY DRY AND WILL SEE A FAIR AMOUNT OF SUN. WILL SEE SOME AREAS OF LOWER CIGS REDEVELOP IN THE EARLY HOURS AS THE UPSLOPE REGIME CONTINUES. BUT BY LATER TONIGHT WILL START TO SEE SOME CLEARING ACROSS THE PLAINS...AS WINDS SHIFT TO THE N-NW OVER ERN CO. WILL SEE SOME LINGERING SHOWERS AND PERHAPS EVEN AN ISOLD TS OVER THE SRN MTS AND RATON MESA AREA OVERNIGHT. ROSE .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 301 AM MDT FRI SEP 11 2015 OVERALL PATTERN THROUGH THE EXTENDED PERIOD WILL SEE THE JET REMAINING TO OUR NORTH WITH A FEW SHORT WAVES UNDULATING IN THE GENERALLY ZONAL FLOW. TEMPERATURES...ESPECIALLY MAXIMUM TEMPERATURES WILL REMAIN ABOVE NORMAL...AND PRECIP WILL LIKELY REMAIN SCANT AT BEST. EXCEPT FOR A FEW AFTERNOON SHOWERS ALONG THE CO/NM BORDER SATURDAY AND SUNDAY...IT WILL REMAIN DRY ACROSS THE REGION. MAX TEMPS WILL GENERALLY BE IN THE 80S TO L90S ACROSS THE PLAINS. ON MONDAY...SOME MONSOON MOISTURE WILL GET ADVECTED OVER THE REGION AND SHOWERS SHOULD BECOME SCATTERED ACROSS THE MTNS WITH ISOLD ACTIVITY OVER THE PLAINS. A BIT COOLER WEATHER WILL OCCUR OVER THE HIGHER TRRN BUT L90S SHOULD CONTINUE OVER THE LOWER ELEVATIONS. THROUGH THE REST OF THE WEEK...SIMULATIONS SHOW A COUPLE OF WEAK SURGES WORKING SOUTH DOWN THE PLAINS AND THIS SHOULD TRIM MAX TEMPS 2-3F DEGREES...ESPECIALLY OVER THE LOWER ELEVATIONS. ANY PRECIP...MAINLY ISOLD...WILL LIKELY REMAIN OVER THE HIGHER TRRN...ESPECIALLY OVER THE CONTDVD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1135 AM MDT FRI SEP 11 2015 MVFR AND VFR STRATUS WILL CONTINUE TO DIMINISH AT COS...PUB AND ACROSS THE LOWER EASTERN SLOPES OF THE SOUTHERN FRONT RANGE THROUGH THE REST OF THE AFTERNOON UNDER GENERALLY WEAK UPSLOPE FLOW. LATEST MODEL DATA SUGGESTS ANY SHOWER AND THUNDERSTORM DEVELOP TO BE FAIRLY SPOTTY AND REMAIN OVER THE HIGHER TERRAIN OF MAINLY THE SOUTHERN MTS. COULD SEE MVFR STRATUS REDEVELOP THROUGH THE EARLY EVENING...MAINLY AT COS...THOUGH WILL KEEP ONLY SCT CLOUDS IN TAFS AT THIS TIME WITH UPSLOPE FLOW NOT TOO DEEP AND MID LEVEL FLOW BECOMING MORE WESTERLY THROUGH THE OVERNIGHT. VFR CONDITIONS EXPECTED AT ALS THROUGH THE NEXT 24 HOURS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...ROSE LONG TERM...HODANISH AVIATION...MW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1005 AM MDT FRI SEP 11 2015 .UPDATE... ISSUED AT 1005 AM MDT FRI SEP 11 2015 UPDATED TO DIMINISH PRECIPITATION CHANCES ACROSS THE AREA WITH LATEST RUNS HIGHER RESOLUTION HRRR AND RAP KEEPING ISOLATED POPS OVER AND NEAR THE EASTERN AND SOUTHWESTERN MTS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 301 AM MDT FRI SEP 11 2015 ...COOL START TO THE WEEKEND... CURRENTLY...LOW CLOUD DECK IS SPREADING OVER THE PLAINS WITH CIGS FROM 15 TO 2500 FT AGL. WINDS GENERALLY FROM THE NE BUT NOT PARTICULARLY STRONG. RADAR HAS BEEN PRETTY QUIET OVERNIGHT...BUT A FEW CONVECTIVE CELLS HAVE MATERIALIZED OVER SRN BACA COUNTY THIS MORNING. MAIN QUESTION TODAY IS HOW EXTENSIVE AND PERSISTENT THE LOW CLOUD DECK WILL BE. MODELS NOT TOO HELPFUL AS THERE IS A WIDE RANGE OF SOLUTIONS...FROM THE 00Z NAM WHICH KEPT MOST OF THE PLAINS UNDER LOW CIGS FOR MOST OF THE DAY...TO SOME OF THE HYR RES MODELS SUCH AS THE HRRR...WHICH APPEARS TO BREAK OUT MUCH OF THE PLAINS BY LATE MORNING. LATEST 06Z NAM SOLUTION HAS BACKED OFF A BIT ON THE EXTENT OF CLOUDS THIS MORN. MODEL SOUNDINGS SHOW A MOIST LAYER THAT IS NOT TERRIBLY DEEP...WITH TOPS FROM 7-9K FEET MSL. CURRENT IR SAT IMAGES SHOW A RAGGED STRETCH OF LOW CIGS ACROSS THE PLAINS. THESE FACTORS POINT TOWARDS A BIT LESS CLOUDINESS THIS AFTERNOON. HOWEVER...THE 1026 MB SFC HIGH OVER THE DAKOTAS WILL CONTINUE BUILDING SWD TODAY...KEEPING A FAIRLY STRONG ERLY GRADIENT INTACT THROUGH THIS EVE. MODERATE S-SE WINDS SHOULD PERSIST THROUGH THIS AFTERNOON...WHICH TYPICALLY IS A RECIPE FOR PERSISTENT LOW CIGS AT KCOS. NAM MOS GUIDANCE BACKS THIS SCENARIO UP. SO...WILL PLAY THE MIDDLE ROAD AND KEEP CLOUDS FOR MOST OF THE PLAINS THROUGH THE MORNING HOURS...WITH SOME BREAKS EXPECTED BY LATE MORNING OR EARLY AFTERNOON. KCOS WILL BE THE TRICKIEST CALL SINCE IT MAY BE ON THE EDGE OF THE CLOUD DECK FOR A WHILE THIS AFTERNOON. AT ANY RATE...CLOUDS WILL KEEP TEMPS CONSIDERABLY LOWER TODAY...WITH HIGHS STRUGGLING TO GET INTO THE LOWER 70S MOST SPOTS. A FEW SPOTTY SHOWERS ALSO LIKELY WHERE THE CLOUD DECK IS THICKEST...MAINLY OVER THE BETTER UPSLOPE REGIONS ALONG THE ERN MTS AND ACROSS THE RATON MESA. A COUPLE STORMS ALSO POSSIBLE LATER THIS AFTERNOON ACROSS OR NR THE HYR TRRN...BUT NOT EXPECTING A LOT OF HEAVY CONVECTION. AREAS W OF THE SRN FRONT RANGE SHOULD STAY DRY AND WILL SEE A FAIR AMOUNT OF SUN. WILL SEE SOME AREAS OF LOWER CIGS REDEVELOP IN THE EARLY HOURS AS THE UPSLOPE REGIME CONTINUES. BUT BY LATER TONIGHT WILL START TO SEE SOME CLEARING ACROSS THE PLAINS...AS WINDS SHIFT TO THE N-NW OVER ERN CO. WILL SEE SOME LINGERING SHOWERS AND PERHAPS EVEN AN ISOLD TS OVER THE SRN MTS AND RATON MESA AREA OVERNIGHT. ROSE .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 301 AM MDT FRI SEP 11 2015 OVERALL PATTERN THROUGH THE EXTENDED PERIOD WILL SEE THE JET REMAINING TO OUR NORTH WITH A FEW SHORT WAVES UNDULATING IN THE GENERALLY ZONAL FLOW. TEMPERATURES...ESPECIALLY MAXIMUM TEMPERATURES WILL REMAIN ABOVE NORMAL...AND PRECIP WILL LIKELY REMAIN SCANT AT BEST. EXCEPT FOR A FEW AFTERNOON SHOWERS ALONG THE CO/NM BORDER SATURDAY AND SUNDAY...IT WILL REMAIN DRY ACROSS THE REGION. MAX TEMPS WILL GENERALLY BE IN THE 80S TO L90S ACROSS THE PLAINS. ON MONDAY...SOME MONSOON MOISTURE WILL GET ADVECTED OVER THE REGION AND SHOWERS SHOULD BECOME SCATTERED ACROSS THE MTNS WITH ISOLD ACTIVITY OVER THE PLAINS. A BIT COOLER WEATHER WILL OCCUR OVER THE HIGHER TRRN BUT L90S SHOULD CONTINUE OVER THE LOWER ELEVATIONS. THROUGH THE REST OF THE WEEK...SIMULATIONS SHOW A COUPLE OF WEAK SURGES WORKING SOUTH DOWN THE PLAINS AND THIS SHOULD TRIM MAX TEMPS 2-3F DEGREES...ESPECIALLY OVER THE LOWER ELEVATIONS. ANY PRECIP...MAINLY ISOLD...WILL LIKELY REMAIN OVER THE HIGHER TRRN...ESPECIALLY OVER THE CONTDVD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 301 AM MDT FRI SEP 11 2015 A FAIR AMOUNT OF UNCERTAINTY PERSISTS THIS MORNING OVER LOW LONG LOW CIGS WILL LAST AT KCOS AND KPUB TODAY. KPUB WILL BE MOST LIKELY TO BREAK OUT FROM MVFR CIGS BY 17-19Z...WHILE KCOS COULD STAY MVFR OR EVEN BRIEFLY IFR FOR A LONGER PORTION OF THE DAY...POSSIBLY INTO THE MID AFTERNOON PERIOD. LOW CIGS SHOULD RETURN AT LEAST BRIEFLY IN THE EARLY EVENING LATER TODAY...BEFORE GRADUAL CLEARING OCCURS TONIGHT... WITH IMPROVING CONDITIONS AFTER 06Z SAT. A FEW STORMS WILL BE POSSIBLE LATER THIS AFTERNOON AND EVE...BUT MAINLY OVER THE SRN AND ERN MTS...AND SHOULD NOT AFFECT THE TAF SITES. KALS SHOULD REMAIN VFR THROUGH THE NEXT 24 HR PERIOD. ROSE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...MW SHORT TERM...ROSE LONG TERM...HODANISH AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
237 PM EDT FRI SEP 11 2015 ...A WET START TO THE WEEKEND IN THE FORECAST... .SYNOPSIS... 16Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS WE NOW HAVE A HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE OVER THE CONUS...AND THE AMPLIFICATION WILL ONLY CONTINUE FOR THE NEXT 12-24 HOURS. PATTERN CURRENTLY SHOWS LONGWAVE RIDGING OVER THE PACIFIC COAST / INTERMOUNTAIN WEST...FOLLOWED DOWNSTREAM BY THE FLOW QUICKLY DIVING INTO AN IMPRESSIVE LONGWAVE TROUGH FROM THE CENTRAL PLAINS TO THE EASTERN STATES. STRONG SHORTWAVE IMPULSE DROPPING DOWN THROUGH THE UPPER MIDWEST...AND CLEARLY EVIDENT WITH WIDESPREAD DRYING ALOFT IN WV IMAGERY WILL FURTHER AMPLIFY THE FLOW AS IT HEADS FOR THE TN VALLEY SATURDAY. CLOSER TO HOME...THE FLORIDA PENINSULA IS STILL UNDER A WEAKENING AREA OF UPPER LEVEL RIDGING...HOWEVER THIS WILL NOT LAST MUCH LONGER AS THE EASTERN CONUS TROUGH DIGS INTO THE EASTERN GULF AND OVER THE STATE FOR SATURDAY. AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS HAS BEEN SHIFTED TO THE SOUTHERN PART OF THE FLORIDA PENINSULA...PROVIDING MUCH OF THE FORECAST AREA WITH A SW LOW LEVEL FLOW OFF THE EASTERN GULF OF MEXICO. THE 12Z SOUNDING DID NOT SHOW ANYTHING PARTICULARLY SIGNIFICANT...WITH A PW AROUND 1.6"...AND WEAK TO MODEST LAPSE RATES. STRONGER LOW LEVEL FLOW ALONG THE NATURE COAST WILL KEEP SEA-BREEZE FOCUS WEAKER AND LIKELY RESULT IN LESS CONVECTIVE COVERAGE THIS AFTERNOON/EARLY EVENING...SIMILAR TO WHAT WAS SEEN ON THURSDAY. ALSO SIMILAR TO THURSDAY...WHERE THE BETTER FOCUS EXISTS TO THE SOUTH OF THE I-4 CORRIDOR IS WHERE WE BELIEVE THE BEST COVERAGE OF SCT SHOWERS/STORMS WILL EXIST THE REMAINDER OF THE DAY. STILL...EVEN THESE AREA WILL ONLY FORECAST 30-50% POPS THROUGH 00Z. && .SHORT TERM (TONIGHT AND SATURDAY)... THE PATTERN AND RESULTING FORECAST WILL BECOME MORE ACTIVE AS WE HEAD INTO THE DAYLIGHT HOURS OF SATURDAY. AS MENTIONED ABOVE...DEEP LAYER MID/UPPER LEVEL TROUGHING WILL CONTINUE TO AMPLIFY INTO THE SOUTHEASTERN CONUS...WITH AN ASSOCIATED SURFACE FRONT MAKING A DECENT PUSH SOUTHWARD TOWARD THE NORTHERN GULF COAST FOR THIS TIME OF YEAR. LINGERING EVENING SHOWERS/STORMS OVER THE INTERIOR SOUTHERN ZONES OF THE PENINSULA WILL FADE WITHIN A FEW HOURS OF SUNSET...AND SET UP A MAINLY DRY OVERNIGHT FOR MUCH OF THE TERRESTRIAL FORECAST AREA. ONLY EXCEPTIONS WILL BE UP TOWARD LEVY/CITRUS COUNTY WHERE THERE IS A POTENTIAL FOR THINGS TO START GETTING WET BEFORE DAWN. MUCH BETTER CHANCES FOR OVERNIGHT SHOWERS/STORMS WILL EXIST OVER THE COASTAL WATERS OF THE NORTHEAST GULF. BY EARLY SATURDAY MORNING. THE CENTRAL AND NORTHERN FLORIDA PENINSULA WILL BE UNDER DEEP LAYER CYCLONIC FLOW TO THE EAST OF THE MAIN TROUGH AXIS. GFS/ECMWF BOTH SHOW A DECENT SWATH OF 700-300MB QVECTOR CONVERGENCE OVERSPREADING THE REGION...BUT MAXIMIZED FROM THE I-4 CORRIDOR NORTHWARD ACROSS THE NATURE COAST. IN ADDITION TO THE OVERALL SYNOPTIC SUPPORT FOR LIFT...FAVORABLE RRQ JET DYNAMICS AND DIFFLUENT FLOW ALOFT WILL FURTHER SUPPORT LARGE SCALE RISING MOTION. SO ALTHOUGH LAPSE RATES LOOK TO BE MARGINAL...WOULD ANTICIPATE AN EXPANDING AREA OF RAIN/EMBEDDED STORMS TO MOVE ASHORE FROM THE NORTHEAST GULF DURING THE MORNING HOURS. HIGHEST POPS WILL BE FROM TAMPA BAY AREA NORTHWARD WITH CATEGORICAL 80-100% POPS IN THE GRIDS. FURTHER SOUTH...WILL START WITH CHANCE SCT SHOWERS DURING THE MORNING HOURS...AND THEN RAMP UP TO NUMEROUS LIKELY COVERAGE FOR THE AFTERNOON. ALTHOUGH THE SYNOPTICS WILL BE WEAKER FOR OUR SOUTHERN ZONES...THESE AREA WILL LIKELY SEE MORE INSOLATION TO SUPPLEMENT ANY LACK OF LARGE SCALE LIFT WITH INSTABILITY. WILL HAVE 60-70% POPS DOWN SOUTH FOR THE AFTERNOON HOURS. GENERALLY SPEAKING WE ARE LOOKING FOR WIDESPREAD RAINFALL TOTALS THROUGH SATURDAY OF 1-1.5" FOR THE NATURE COAST...AND RANGING DOWN TO ABOUT 0.5" FOR CHARLOTTE/LEE COUNTIES. HOWEVER...KEEP IN MIND...THAT INDIVIDUAL STRONGER OR TRAINING STORM COMPLEXES COULD DELIVER LOCALLY HIGHER TOTALS. NOT EXPECTED MUCH IN THE WAY OF SEVERE WEATHER...BUT GIVEN THE SYNOPTICS IN PLACE AND A BIT MORE LOW LEVEL WIND ENERGY THAN IS NORMAL FOR THE MIDDLE OF SEPTEMBER...A FEW MORE POTENT STORMS ARE NOT OUT OF THE QUESTION. THE MAIN THREAT FROM ANY STRONGER STORMS WOULD BE LOCALLY STRONG WIND GUSTS...AND OF COURSE POSSIBLE FLOODING. ONE GOOD THING ABOUT THIS SETUP...IS THAT STORM MOTION WILL BE QUITE FAST...SO UNLESS STORMS ARE TRAINING...ANY HEAVIER POCKETS OF RAIN SHOULD NOT LAST TOO LONG OVER ANY ONE PARTICULAR LOCATION. && .MID/LONG TERM (SATURDAY NIGHT - FRIDAY...A DEEPENING TROUGH CONTINUES TO DIG IN FROM THE GREAT LAKES SOUTHWARD THROUGH THE MISSISSIPPI RIVER VALLEY AND INTO THE NORTHERN GULF OF MEXICO. THE TROUGH CONTINUES TO DEEPEN FURTHER OVER THE NORTHERN HALF OF THE FLORIDA PENINSULA BY SUNDAY MORNING...THEN WILL SLOWLY PROGRESS NORTHEASTWARD AND CLOSE OFF INTO A CLOSED UPPER LOW OVER NEW YORK BY SUNDAY EVENING. THE UPPER LOW SLIGHTLY FILLS AS IT TRAVERSES NORTHEAST OFF THE NEW ENGLAND COAST TOWARD NOVA SCOTIA. AS THE UPPER LOW MOVES NORTHEAST...HIGH PRESSURE RIDGING BUILDS INTO THE SOUTHEAST CONUS. BY LATE TUESDAY...AN UPPER LEVEL HIGH SETS UP OVER THE FLORIDA PENINSULA AND WILL BUILD FARTHER WESTWARD INTO THE GULF OF MEXICO THROUGH THE REMAINDER OF NEXT WEEK. ON THE SURFACE...A LOW PRESSURE CENTER DEVELOPS OVER THE DELMARVA PENINSULA AND EXTENDS A COLD FRONT SOUTHWEST ALONG THE EASTERN SEABOARD...OVER THE NORTHERN HALF OF FLORIDA AND INTO THE GULF OF MEXICO. A 30-40 KNOT MID LEVEL JET...COMBINED WITH ABUNDANT MOISTURE AND FRONTAL LIFT WILL SUPPORT WIDESPREAD RAIN SHOWERS AND STORMS THROUGH SUNDAY EVENING. SOME OF THESE STORMS MAY PRODUCE DAMAGING WINDS AND HEAVY DOWNPOURS. HEAVY RAINS WILL ONLY AGGRAVATE THE RIVER FLOODING THAT IS OCCURRING AT SEVERAL LOCAL RIVERS AND WILL BE CLOSELY MONITORED FOR ANY SIGNIFICANT RISE OVER THE WEEKEND. THE PARENT LOW MOVES NORTHEAST ALONG THE NEW ENGLAND COAST AND WILL BE LOCATED BETWEEN MAINE AND NOVA SCOTIA BY MONDAY MORNING. THE ASSOCIATED FRONTAL BOUNDARY WILL SHIFT EAST AND SOUTH AS STRONG CONTINENTAL HIGH PRESSURE MOVES INTO THE MID-ATLANTIC STATES. AS THE HIGH PRESSURE BUILDS SOUTH...THE FRONT SLOWLY WASHES OUT. WINDS AHEAD OF THE FRONT WILL REMAIN OUT OF THE SOUTHWEST AND THEN SHIFT TO NORTHEAST AND THEN EASTERLY IN BETWEEN THE FRONT TO THE SOUTH AND HIGH PRESSURE TO THE NORTH. WITH LINGERING MOISTURE FROM THE FRONT AND MOIST EASTERLY WIND FLOW...FORECAST PWAT VALUES WILL REMAIN BETWEEN 1.75-2.00 INCHES SO THE ENVIRONMENT WILL STILL BE CAPABLE OF PRODUCING SCATTERED SHOWERS AND STORMS THROUGH THE WEEK. WITH AN EASTERLY WIND FLOW...THE HIGHEST COVERAGE WILL COME OVER THE INLAND AREAS EARLIER IN DAY AND MOVING TOWARD THE WEST COAST OF FLORIDA AND COASTAL WATERS LATER IN THE EVENING. TEMPERATURES WILL BE A FEW DEGREES COOLER ON SATURDAY AND SUNDAY DUE TO EXTENSIVE CLOUDINESS AND RAINFALL...THEN WARMING BACK UP TO NORMAL BY THE BEGINNING OF NEXT WEEK. && .AVIATION... VFR CONDITIONS GENERALLY PREVAIL ACROSS THE REGION EARLY THIS AFTERNOON...ALTHOUGH A SCATTERING OF SHOWERS HAS BEGUN TO DEVELOP ACROSS THE SOUTHERN ZONES AROUND KPGD/KFMY/KRSW. ANY OF THESE TERMINALS MAY SEE A BRIEF DOWNPOUR THROUGH THE AFTERNOON WITH WIDELY SCT STORM DIMINISHING THIS EVENING. GENERAL VFR CONDITIONS CONTINUE OVERNIGHT...WITH INCREASING CHANCES FOR SHOWERS OFF THE GULF TOWARD DAWN. KTPA/KPIE/KLAL/KSRQ EXPECT NUMEROUS SHOWERS THROUGHOUT SATURDAY...WITH MORE SCATTERED ACTIVITY FURTHER SOUTH. && .MARINE... HIGH PRESSURE OVER THE EASTERN GULF WILL WEAKEN AND PUSH SOUTH LATE TODAY AND TONIGHT IN RESPONSE TO THE APPROACH OF A COLD FRONT FROM THE NORTH. THIS FRONT WILL REACH THE NORTHEAST GULF OF MEXICO LATE SATURDAY AND SATURDAY NIGHT...AND THEN WEAKEN QUICKLY AS IT SLOWLY SAGS SOUTH DURING SUNDAY. SHOWERS AND STORMS WILL BE NUMEROUS IN NATURE OVER THE EASTERN GULF ON SATURDAY AHEAD OF THIS FRONT. WINDS MAY BRIEFLY APPROACH CAUTIONARY LEVELS TO THE NORTH OF TAMPA BAY LATE SATURDAY NIGHT...HOWEVER THE WEAKENING NATURE OF THE FRONT SHOULD KEEP ANY ELEVATED WINDS OF SHORT DURATION. && .FIRE WEATHER... NO SIGNIFICANT FIRE WEATHER CONCERNS ARE ANTICIPATED THROUGH THE WEEKEND IN TERMS OF LOW RELATIVE HUMIDITY OR STRONG WINDS. SOUTHWEST WINDS OFF THE GULF OF MEXICO AHEAD OF AN APPROACHING FRONT WILL KEEP ABUNDANT LOW LEVEL MOISTURE IN PLACE. SHOWERS AND STORMS WILL BE INCREASING IN COVERAGE DURING SATURDAY...WITH THE HEAVIEST RAINFALL POTENTIAL FROM THE I-4 CORRIDOR NORTHWARD. MORE SCATTERED TO NUMEROUS SHOWERS WILL BE IN THE FORECAST FOR SUNDAY...HOWEVER THE MOST WIDESPREAD SHOWERS BY THIS TIME WILL HAVE SETTLED TO THE I-4 CORRIDOR AND SOUTHWARD. && .PRELIMINARY POINT TEMPS/POPS... TPA 78 85 75 85 / 20 90 70 80 FMY 77 88 76 88 / 20 70 50 70 GIF 75 87 74 86 / 20 80 60 70 SRQ 77 85 76 86 / 20 70 60 80 BKV 74 85 71 86 / 20 100 70 70 SPG 78 85 76 85 / 20 90 70 80 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA MID/LONG TERM/DECISION SUPPORT...74/WYNN
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1207 PM EDT FRI SEP 11 2015 ...A WET START TO THE WEEKEND IN THE FORECAST... .SYNOPSIS... 16Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS WE NOW HAVE A HIGHLY AMPLIFIED UPPER LEVEL PATTERN IN PLACE OVER THE CONUS...AND THE AMPLIFICATION WILL ONLY CONTINUE FOR THE NEXT 12-24 HOURS. PATTERN CURRENTLY SHOWS LONGWAVE RIDGING OVER THE PACIFIC COAST / INTERMOUNTAIN WEST...FOLLOWED DOWNSTREAM BY THE FLOW QUICKLY DIVING INTO AN IMPRESSIVE LONGWAVE TROUGH FROM THE CENTRAL PLAINS TO THE EASTERN STATES. STRONG SHORTWAVE IMPULSE DROPPING DOWN THROUGH THE UPPER MIDWEST...AND CLEARLY EVIDENT WITH WIDESPREAD DRYING ALOFT IN WV IMAGERY WILL FURTHER AMPLIFY THE FLOW AS IT HEADS FOR THE TN VALLEY SATURDAY. CLOSER TO HOME...THE FLORIDA PENINSULA IS STILL UNDER A WEAKENING AREA OF UPPER LEVEL RIDGING...HOWEVER THIS WILL NOT LAST MUCH LONGER AS THE EASTERN CONUS TROUGH DIGS INTO THE EASTERN GULF AND OVER THE STATE FOR SATURDAY. AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS HAS BEEN SHIFTED TO THE SOUTHERN PART OF THE FLORIDA PENINSULA...PROVIDING MUCH OF THE FORECAST AREA WITH A SW LOW LEVEL FLOW OFF THE EASTERN GULF OF MEXICO. THE 12Z SOUNDING DID NOT SHOW ANYTHING PARTICULARLY SIGNIFICANT...WITH A PW AROUND 1.6"...AND WEAK TO MODEST LAPSE RATES. STRONGER LOW LEVEL FLOW ALONG THE NATURE COAST WILL KEEP SEA-BREEZE FOCUS WEAKER AND LIKELY RESULT IN LESS CONVECTIVE COVERAGE THIS AFTERNOON/EARLY EVENING...SIMILAR TO WHAT WAS SEEN ON THURSDAY. ALSO SIMILAR TO THURSDAY...WHERE THE BETTER FOCUS EXISTS TO THE SOUTH OF THE I-4 CORRIDOR IS WHERE WE BELIEVE THE BEST COVERAGE OF SCT SHOWERS/STORMS WILL EXIST THE REMAINDER OF THE DAY. STILL...EVEN THESE AREA WILL ONLY FORECAST 30-50% POPS THROUGH 00Z. && .SHORT TERM (TONIGHT AND SATURDAY)... THE PATTERN AND RESULTING FORECAST WILL BECOME MORE ACTIVE AS WE HEAD INTO THE DAYLIGHT HOURS OF SATURDAY. AS MENTIONED ABOVE...DEEP LAYER MID/UPPER LEVEL TROUGHING WILL CONTINUE TO AMPLIFY INTO THE SOUTHEASTERN CONUS...WITH AN ASSOCIATED SURFACE FRONT MAKING A DECENT PUSH SOUTHWARD TOWARD THE NORTHERN GULF COAST FOR THIS TIME OF YEAR. LINGERING EVENING SHOWERS/STORMS OVER THE INTERIOR SOUTHERN ZONES OF THE PENINSULA WILL FADE WITHIN A FEW HOURS OF SUNSET...AND SET UP A MAINLY DRY OVERNIGHT FOR MUCH OF THE TERRESTRIAL FORECAST AREA. ONLY EXCEPTIONS WILL BE UP TOWARD LEVY/CITRUS COUNTY WHERE THERE IS A POTENTIAL FOR THINGS TO START GETTING WET BEFORE DAWN. MUCH BETTER CHANCES FOR OVERNIGHT SHOWERS/STORMS WILL EXIST OVER THE COASTAL WATERS OF THE NORTHEAST GULF. BY EARLY SATURDAY MORNING. THE CENTRAL AND NORTHERN FLORIDA PENINSULA WILL BE UNDER DEEP LAYER CYCLONIC FLOW TO THE EAST OF THE MAIN TROUGH AXIS. GFS/ECMWF BOTH SHOW A DECENT SWATH OF 700-300MB QVECTOR CONVERGENCE OVERSPREADING THE REGION...BUT MAXIMIZED FROM THE I-4 CORRIDOR NORTHWARD ACROSS THE NATURE COAST. IN ADDITION TO THE OVERALL SYNOPTIC SUPPORT FOR LIFT...FAVORABLE RRQ JET DYNAMICS AND DIFFLUENT FLOW ALOFT WILL FURTHER SUPPORT LARGE SCALE RISING MOTION. SO ALTHOUGH LAPSE RATES LOOK TO BE MARGINAL...WOULD ANTICIPATE AN EXPANDING AREA OF RAIN/EMBEDDED STORMS TO MOVE ASHORE FROM THE NORTHEAST GULF DURING THE MORNING HOURS. HIGHEST POPS WILL BE FROM TAMPA BAY AREA NORTHWARD WITH CATEGORICAL 80-100% POPS IN THE GRIDS. FURTHER SOUTH...WILL START WITH CHANCE SCT SHOWERS DURING THE MORNING HOURS...AND THEN RAMP UP TO NUMEROUS LIKELY COVERAGE FOR THE AFTERNOON. ALTHOUGH THE SYNOPTICS WILL BE WEAKER FOR OUR SOUTHERN ZONES...THESE AREA WILL LIKELY SEE MORE INSOLATION TO SUPPLEMENT ANY LACK OF LARGE SCALE LIFT WITH INSTABILITY. WILL HAVE 60-70% POPS DOWN SOUTH FOR THE AFTERNOON HOURS. GENERALLY SPEAKING WE ARE LOOKING FOR WIDESPREAD RAINFALL TOTALS THROUGH SATURDAY OF 1-1.5" FOR THE NATURE COAST...AND RANGING DOWN TO ABOUT 0.5" FOR CHARLOTTE/LEE COUNTIES. HOWEVER...KEEP IN MIND...THAT INDIVIDUAL STRONGER OR TRAINING STORM COMPLEXES COULD DELIVER LOCALLY HIGHER TOTALS. NOT EXPECTED MUCH IN THE WAY OF SEVERE WEATHER...BUT GIVEN THE SYNOPTICS IN PLACE AND A BIT MORE LOW LEVEL WIND ENERGY THAN IS NORMAL FOR THE MIDDLE OF SEPTEMBER...A FEW MORE POTENT STORMS ARE NOT OUT OF THE QUESTION. THE MAIN THREAT FROM ANY STRONGER STORMS WOULD BE LOCALLY STRONG WIND GUSTS...AND OF COURSE POSSIBLE FLOODING. ONE GOOD THING ABOUT THIS SETUP...IS THAT STORM MOTION WILL BE QUITE FAST...SO UNLESS STORMS ARE TRAINING...ANY HEAVIER POCKETS OF RAIN SHOULD NOT LAST TOO LONG OVER ANY ONE PARTICULAR LOCATION. && .LONG TERM (SATURDAY NIGHT - THURSDAY)... AN UPPER LOW IN THE OHIO VALLEY/UPPER GREAT LAKES REGION SAT NIGHT TROUGHS DOWN INTO THE GULF OF MEXICO. A SURFACE REFLECTION OF THE UPPER LOW IS BETWEEN THE MID-ATLANTIC STATES AND THE LOWER GREAT LAKES AND TRAILS A COLD FRONT DOWN THE EASTERN SEABOARD THEN WEST ALONG NORTHERN GULF WATERS. CANADIAN HIGH PRESSURE SPRAWLS FROM THE UPPER MIDWEST TO THE SOUTHERN PLAINS WHILE ATLANTIC HIGH PRESSURE RIDGES WEST...REACHING THE BAHAMAS. SUN-MON: THE UPPER LOW AND IT/S TROUGH LIFTS NORTHEASTWARD...TO NEW ENGLAND OR THE SAINT LAWRENCE VALLEY...WHILE A RIDGE OVER THE ATLANTIC BUILDS TOWARD THE SOUTHEAST U.S. COAST. THE SURFACE LOW MOVES TO NEW BRUNSWICK/NOVA SCOTIA WITH THE FRONT ARCING OUT OVER THE ATLANTIC...WITH THE WESTERN PORTION WEAKENING AND SAGGING SOUTH OVER THE GULF AND NORTHERN FL. THE MID CONUS HIGH TREKS EAST TO THE MID-ATLANTIC COAST. SCATTERED TO WIDESPREAD SHOWERS AND ISOLATED TO SCATTERED THUNDER- STORMS WILL TREND DOWN TO ISOLATED TO SCATTERED SHOWERS AND STORMS. SOME OF THE STORMS...ESPECIALLY SUN...MAY BECOME ROBUST WITH GUSTY WINDS AND LOCALLY HEAVY RAINFALL. AN INITIAL WESTERLY FLOW VEERS TO NORTHEASTERLY AS THE FRONT MOVES SOUTH AND THE SURFACE HIGH PRESSURE REACHES THE MID-ATLANTIC COAST. TEMPERATURES WILL RUN NEAR NORMAL FOR THE LOWS...THE HIGHS WILL STAY ON THE COOL SIDE OF NORMAL THANKS TO RAINFALL AND CLOUDS. TUE-THU: THE UPPER RIDGE CONTINUES TO BUILD WEST AND SPREADS ACROSS THE EASTERN STATES AND GULF BEFORE WEAKENING AND SHIFTING SOUTH ON THU. THE SURFACE HIGH REMAINS ON THE COAST THROUGH WED THEN SLIDES OFFSHORE THU. THE FRONT...BY NOW MORE OF MOISTURE BOUNDARY...SLOWLY SETTLES SOUTH DOWN FL AND CONTINUES TO WEAKEN. DESPITE THE UPPER RIDGE BUILDING IN THE DECAYING FRONTAL BOUNDARY ALONG WITH EASTERLY FLOW...AS THE HIGH TO THE NORTH BEGINS TO DOMINATE...WILL PROVIDE ADEQUATE MOISTURE FOR ISOLATED TO SCATTERED SHOWERS AND STORMS...BUT LOCALLY NUMEROUS. TIMING WILL GENERALLY FAVOR AFTERNOONS AND EARLY EVENINGS. TEMPERATURES RUN JUST ABOVE NORMAL FOR THE LOWS...THE HIGHS WILL FLUCTUATE AROUND NORMAL. && .AVIATION... VFR CONDITIONS GENERALLY PREVAIL ACROSS THE REGION EARLY THIS AFTERNOON...ALTHOUGH A SCATTERING OF SHOWERS HAS BEGUN TO DEVELOP ACROSS THE SOUTHERN ZONES AROUND KPGD/KFMY/KRSW. ANY OF THESE TERMINALS MAY SEE A BRIEF DOWNPOUR THROUGH THE AFTERNOON WITH WIDELY SCT STORM DIMINISHING THIS EVENING. GENERAL VFR CONDITIONS CONTINUE OVERNIGHT...WITH INCREASING CHANCES FOR SHOWERS OFF THE GULF TOWARD DAWN. KTPA/KPIE/KLAL/KSRQ EXPECT NUMEROUS SHOWERS THROUGHOUT SATURDAY...WITH MORE SCATTERED ACTIVITY FURTHER SOUTH. && .MARINE... HIGH PRESSURE OVER THE EASTERN GULF WILL WEAKEN AND PUSH SOUTH LATE TODAY AND TONIGHT IN RESPONSE TO THE APPROACH OF A COLD FRONT FROM THE NORTH. THIS FRONT WILL REACH THE NORTHEAST GULF OF MEXICO LATE SATURDAY AND SATURDAY NIGHT...AND THEN WEAKEN QUICKLY AS IT SLOWLY SAGS SOUTH DURING SUNDAY. SHOWERS AND STORMS WILL BE NUMEROUS IN NATURE OVER THE EASTERN GULF ON SATURDAY AHEAD OF THIS FRONT. WINDS MAY BRIEFLY APPROACH CAUTIONARY LEVELS TO THE NORTH OF TAMPA BAY LATE SATURDAY NIGHT...HOWEVER THE WEAKENING NATURE OF THE FRONT SHOULD KEEP ANY ELEVATED WINDS OF SHORT DURATION. && .FIRE WEATHER... NO SIGNIFICANT FIRE WEATHER CONCERNS ARE ANTICIPATED THROUGH THE WEEKEND IN TERMS OF LOW RELATIVE HUMIDITY OR STRONG WINDS. SOUTHWEST WINDS OFF THE GULF OF MEXICO AHEAD OF AN APPROACHING FRONT WILL KEEP ABUNDANT LOW LEVEL MOISTURE IN PLACE. SHOWERS AND STORMS WILL BE INCREASING IN COVERAGE DURING SATURDAY...WITH THE HEAVIEST RAINFALL POTENTIAL FROM THE I-4 CORRIDOR NORTHWARD. MORE SCATTERED TO NUMEROUS SHOWERS WILL BE IN THE FORECAST FOR SUNDAY...HOWEVER THE MOST WIDESPREAD SHOWERS BY THIS TIME WILL HAVE SETTLED TO THE I-4 CORRIDOR AND SOUTHWARD. && .PRELIMINARY POINT TEMPS/POPS... TPA 78 85 75 85 / 20 90 70 80 FMY 77 88 76 89 / 20 70 50 60 GIF 75 87 73 87 / 20 80 50 70 SRQ 77 85 75 87 / 20 70 70 80 BKV 74 85 71 85 / 20 100 70 70 SPG 78 85 76 85 / 20 90 70 80 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1228 PM CDT FRI SEP 11 2015 .UPDATE... ISSUED AT 1007 AM CDT FRI SEP 11 2015 Back edge of precipitation shield is now generally east of a Bloomington to Springfield line, and the clearing line is trying to penetrate the Illinois River Valley. However, clouds are increasing a bit over northern Illinois in response to a shortwave swinging southeast across Iowa, and latest RAP model guidance indicates periods of diurnal clouds through the afternoon across the western CWA as the associated cold air aloft settles into the area. Much of this area should remain dry this afternoon, but the wind trajectory off Lake Michigan will combine with the trough to keep clouds and some showers lingering across the east through the afternoon. A couple thunderstorms may occur as well with some higher lapse rates aloft. Recent zone/grid update updated the precipitation trends, and nudged high temperatures down a bit across the east where the clouds will persist the longest. && .SHORT TERM...(TODAY) ISSUED AT 334 AM CDT FRI SEP 11 2015 A weakening MCS over Missouri continues to move east toward southern IL early this morning while an upper level shortwave approaches central IL via Iowa. A cold front at the surface has pushed southward to around I-64 however convergence aloft due to the interaction of the above features is triggering numerous thunderstorms across central IL. Modest instability generally under 500 J/kg according to SPC mesoscale analysis has kept most of the storms fairly weak to moderate...however some heavy rainfall corridors have developed due to orientation of repeated thunderstorms. This system will gradually move eastward through the early afternoon with thunderstorms tapering off from west to east. Meanwhile...much colder air aloft moving into the region from the north will bring lake effect rain showers off of Lake Michigan...some of these could trigger a some more showers and isolated thunder out to Vermilion and Champaign counties and this is hinted at by several models. Highs today will only reach the lower 70s given the cooler post frontal air mass which has moved in. .LONG TERM...(TONIGHT THROUGH Thursday) ISSUED AT 334 AM CDT FRI SEP 11 2015 Much cooler temperatures expected this weekend due to strong upper level trof/low pressure digging southward from the western great lakes into IL/IN and ohio river valley through Saturday. Have a slight chance of showers into mid evening from Bloomington to Champaign to Paris northeast. Then isolated chances of showers returns on Sat with partly to mostly cloudy skies and breezy north winds, especially east of the IL river with best chances over east central IL. Lows tonight in the upper 40s/lower 50s with mildest readings south of I-72. Cool highs Saturday mostly in the mid 60s. Strong upper level trof pushes east of IL Sat night and Sunday while 1025 mb Canadian high pressure over ND settles into the mid MS river valley Sunday morning. Clouds and wind decrease Sat night and sets us up for cooler night with lows 43-48F. A pleasant day expected Sunday with ample sunshine and highs in the lower 70s, expect a few upper 60s in eastern IL. Not quite as cool Sunday night as high pressure slips SE of IL toward the central Appalachians. Lows around 50F in eastern IL and mid 50s near the MS river valley of west central IL. 00Z medium and extended range models show upper level high pressure ridge building across the eastern U.S. Monday through Wed and providing dry and warmer weather to IL. Highs Monday in the mid to upper 70s with west central IL near 80F, climb into the lower 80s Tue and mid 80s Wed and back to the lower 80s Thu. A cold front to push into the southern Great Lakes by sunset Thursday and to bring an increasing chance of showers and thunderstorms Thu/Fri. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Saturday AFTERNOON) ISSUED AT 1228 PM CDT FRI SEP 11 2015 Large deck of MVFR ceilings is persisting east of a KSTL-KIKK line and settling southward, with the area west of there seeing some brief MVFR conditions as diurnal clouds become more elevated. Have kept some MVFR ceilings in the TAF`s for a couple more hours, before the larger cloud deck exits the area. Will likely be a period of clear skies early tonight, but more clouds will stream southward as a deep upper trough passes overhead. Forecast soundings show these mainly above 5000 feet, although KCMI will be closer to the low end of VFR conditions as a persistent wind trajectory comes off Lake Michigan. This may also result in some showers Saturday morning. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SHORT TERM...Onton LONG TERM...07 AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
333 PM MDT FRI SEP 11 2015 .SYNOPSIS... A BACK DOOR COLD FRONT SLIDING INTO EASTERN NEW MEXICO TODAY WILL CONTINUE TO CREATE GUSTY WINDS...PARTICULARLY BELOW CANYONS IN THE RIO GRANDE VALLEY. AREAS ON THE EAST SIDE OF ALBUQUERQUE MAY GUST UP TO 35 MPH THIS EVENING. ISOLATED THUNDERSTORMS WILL DEVELOP OVER THE STATE THIS WEEKEND...ESPECIALLY THE SOUTHERN HIGH TERRAIN. A SLIGHT UPTICK IN STORM COVERAGE IS EXPECTED FOR WESTERN NEW MEXICO MONDAY AND TUESDAY. DRIER AND BREEZY CONDITIONS WILL RETURN TO THE STATE NEXT WEEK BEFORE A POTENTIAL INCREASE IN MOISTURE BY NEXT FRIDAY. && .DISCUSSION... THE POST-FRONTAL INVERSION OVER EASTERN NM IS HOLDING STRONG AND CAPPING CHANCES AT RELEASING WHAT LITTLE SURFACE INSTABILITY IS PRESENT OVER THE AREA. THIS IS ALSO EVIDENCED BY SCATTERED WAVE CLOUDS ALONG AND EAST OF THE CENTRAL MT CHAIN. FORCING ALONG THE SURFACE FRONT AND STRONG HEATING OVER CHAVES COUNTY IS PROVIDING INSTABILITY FOR AT LEAST ISOLD ACTIVITY. A FEW MEAGER SHOWERS ARE ATTEMPTING TO FIRE UP OVER THE NORTHERN HIGH TERRAIN WITH LITTLE SUCCESS. THE LATEST HRRR/RUC AND LOCAL WRF AGREE WITH THE SPC SSEO THAT THE VAST MAJORITY OF ACTIVITY WILL TAPER OFF AFTER SUNSET. THE 12Z GFS WAS STILL VERY WET FOR THE HIGH PLAINS THIS EVENING BUT REMAINDER OF DETERMINISTIC GUIDANCE IS ON THE DRY SIDE. THE 18Z NAM STILL SHOWS LOW CLOUDS REDEVELOPING OVER THE EAST WITH PERHAPS SOME LIGHT RAIN OVERNIGHT. OVERALL LOWERED POPS AND REMOVED MENTION OF THUNDER AFTER MIDNIGHT. THE OTHER STORY HAS BEEN GAP WINDS IN THE RIO GRANDE VALLEY...WHICH ARE STILL PROGGED TO INCREASE DURING THE EVENING. THE 19Z HRRR HAS DELAYED THE PEAK WINDS FOR THE ABQ EAST SIDE UNTIL BTWN 8PM AND 1AM...WHICH IS CONSISTENT WITH THE LATEST MET/MAV/ECS MOS GUIDANCE. THIS WEEKEND LOOKS GENERALLY TRANQUIL AT THIS TIME WITH ONLY ISOLD STORMS RECYCLING UNDER THE H5 RIDGE CRESTING EASTWARD FROM THE GREAT BASIN. THE BEST STORM CHANCES WILL FOCUS OVER THE HIGHER TERRAIN OF CATRON COUNTY AS INCREASINGLY MOIST SOUTHWEST FLOW ARRIVES OVER THE AREA. TEMPS WILL REBOUND SEVERAL DEGREES SATURDAY OVER THE EAST THEN BECOME HOT AGAIN BY SUNDAY WITH BETTER KATABATIC FLOW. MODELS ARE STILL STRUGGLING WITH MOISTURE DELIVERY MONDAY/TUESDAY AS SEVERAL COMPLEX UPPER FEATURES SHEAR EASTWARD AHEAD OF A DEVELOPING LARGE SCALE UPPER TROUGH ALONG THE WEST COAST. IT APPEARS THAT THE WESTERN THIRD WILL STILL FAVOR ISOLATED STORMS...HOWEVER TRENDS ARE EVEN DRIER. LEE TROUGHING INCREASING OVER THE EAST WILL ALLOW FOR WINDS TO TREND UP WITH HOT TEMPS ONCE AGAIN. EXTENDED TRENDS TOWARD A WETTER PATTERN ARE ADVERTISED NOW BY BOTH THE GFS AND ECMWF BEYOND FRIDAY. THERE ARE SOME INTERESTING FEATURES TO ANALYZE AS AN ELONGATED UPPER RIDGE DEVELOPS OVER NORTHERN MEXICO WITH FAST WSW FLOW ALOFT OVER THE NORTHERN ROCKIES. THE 700-500MB LEVEL MOISTURE PATTERN HAS INDICATIONS OF A TAP TO THE EASTERN PACIFIC. THIS COULD BE AN INITIAL SIGN OF THE LONG ANTICIPATED ACTIVE SUBTROPICAL JET MORE COMMON WITH EL NINO IN THE SW CONUS. GUYER && .FIRE WEATHER... THE BACK DOOR COLD FRONT ARRIVED EARLIER THAN SCHEDULED TODAY BRINGING STABLER AIR OVER THE FIRE WEATHER FORECAST AREA. THE FRONT DID BRING SOME LOW LEVEL MOISTURE INTO THE AREA AND THIS WILL RECYCLE ON SATURDAY AS AN UPPER HIGH OVER THE GREAT BASIN BEGINS TO MIGRATE IN THIS DIRECTION. MAINLY ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED SATURDAY...EXCEPT FOR SOME SCATTERED ACTIVITY OVER THE SW MOUNTAINS. TEMPERATURES AND VENTILATION WILL GENERALLY TREND UPWARD WHILE HUMIDITIES TREND DOWNWARD. SUNDAY THE UPPER HIGH WILL WEAKEN INTO A RIDGE OF HIGHER PRESSURE WITH AN AXIS ORIENTED NORTH TO SOUTH ALONG NEW MEXICOS RIO GRANDE VALLEY. THIS WILL FUNNEL MOISTURE NORTHWARD OVER WESTERN PARTS OF THE FORECAST AREA WHERE AN UPTICK IN HUMIDITIES AND THUNDERSTORM COVERAGE IS EXPECTED WITH A SLIGHT DROP IN TEMPERATURES. ELSEWHERE TEMPERATURES WILL CONTINUE TO WARM WHILE HUMIDITIES FALL. HIGH HAINES INDICES IN THE 5 TO 6 RANGE ARE EXPECTED ALONG AND NORTH OF I- 40. MONDAY THROUGH THE MIDDLE OF NEXT WEEK MOISTURE SHOULD CONTINUE TO FUNNEL OVER WESTERN AREAS...AND TO A LESSER EXTENT CENTRAL AREAS...AS A LONG WAVE TROUGH TAKES SHAPE OVER THE W COAST. SHORTWAVE TROUGHS WILL EJECT NORTHEASTWARD FROM THIS FEATURE ACROSS THE NORTHERN AND CENTRAL ROCKIES MONDAY AND TUESDAY...INTERACTING WITH THIS MOISTURE AND STRENGTHENING THE FLOW ALOFT FOR AN UPTICK IN SHOWER AND THUNDERSTORM ACTIVITY ON THESE DAYS. THE MONSOON PLUME MAY WEAKEN SOME WEDNESDAY AND THURSDAY IF SOME DRIER AIR CAN GET ENTRAINED IN THE WAKE OF MONDAY AND TUESDAYS SHORTWAVES AS DEPICTED BY THE GFS AND ECMWF. ALSO ON MONDAY...A LEE TROUGH SHOULD TRIGGER BREEZY TO WINDY CONDITIONS ACROSS THE NORTHEAST HIGHLANDS AND PLAINS. 44 && .AVIATION... 18Z TAF CYCLE MODELS HAVE BEEN TRENDING DOWNWARD ON THE PCPN COVERAGE PROGNOSIS FOR TODAY...PROBABLY BECAUSE THE BACK DOOR COLD FRONT ARRIVED EARLIER THAN EXPECTED. THE FRONT SHOULD REACH THE AZ BORDER THIS AFTN. THE ATMOSPHERE BEHIND THE FRONT IS SIGNIFICANTLY MORE STABLE...BUT THERE SHOULD STILL BE ENOUGH INSTABILITY FOR SCT TO ISOLD TS/SHRA ALONG AND E OF THE CENTRAL MT CHAIN AS WELL AS THE SOUTHERN TIER OF MTS. SOME PRECIP MAY LINGER IN THESE AREAS INTO TONIGHT...BUT THE BIGGER IMPACT WILL BE WDSPR IFR AND MVFR CONDITIONS IN LOW CLOUDS E OF THE CENTRAL MT CHAIN. SOME OF THESE SHOULD EVEN WORK THEIR WAY INTO THE KSAF AREA. ONE TRUSTED MODEL SUGGESTS MVFR CONDITIONS AROUND ALBUQUERQUE TOO...BUT IT IS VERY UNCOMMON FOR KABQ AND KAEG TO DROP BELOW VFR IN THIS PARTICULAR SCENARIO. LOW CLOUDS SHOULD BURN OFF MOST PLACES BY MID TO LATE MORNING ON SATURDAY AS A DEVELOPING LEE TROUGH SHIFTS SFC WINDS OUT OF THE W AND SW. 44 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 53 89 51 89 / 0 5 0 0 DULCE........................... 41 81 38 82 / 5 5 5 5 CUBA............................ 48 78 46 79 / 10 5 5 5 GALLUP.......................... 44 88 44 85 / 0 10 5 10 EL MORRO........................ 43 80 43 78 / 10 10 10 30 GRANTS.......................... 46 84 43 83 / 10 10 5 20 QUEMADO......................... 53 81 53 78 / 5 30 20 30 GLENWOOD........................ 53 81 53 81 / 10 30 20 30 CHAMA........................... 44 74 44 75 / 10 10 5 5 LOS ALAMOS...................... 56 79 57 81 / 20 20 10 5 PECOS........................... 52 76 53 79 / 30 20 10 5 CERRO/QUESTA.................... 52 76 49 78 / 20 10 5 5 RED RIVER....................... 43 71 39 71 / 30 20 10 5 ANGEL FIRE...................... 51 66 49 68 / 30 20 10 5 TAOS............................ 47 80 42 82 / 10 5 5 5 MORA............................ 52 74 48 76 / 30 20 10 5 ESPANOLA........................ 50 85 49 87 / 5 5 0 5 SANTA FE........................ 56 78 56 80 / 20 10 5 5 SANTA FE AIRPORT................ 55 85 52 86 / 10 5 5 5 ALBUQUERQUE FOOTHILLS........... 60 86 60 87 / 10 10 5 5 ALBUQUERQUE HEIGHTS............. 63 88 62 89 / 5 10 5 5 ALBUQUERQUE VALLEY.............. 59 90 59 91 / 5 5 5 5 ALBUQUERQUE WEST MESA........... 60 90 60 91 / 5 5 5 5 LOS LUNAS....................... 57 90 54 91 / 5 10 5 5 RIO RANCHO...................... 59 90 59 90 / 5 5 0 5 SOCORRO......................... 60 89 59 90 / 10 30 20 20 SANDIA PARK/CEDAR CREST......... 53 82 54 83 / 20 10 10 5 TIJERAS......................... 55 84 56 85 / 20 10 5 5 MORIARTY/ESTANCIA............... 48 84 47 86 / 20 10 10 5 CLINES CORNERS.................. 52 79 54 82 / 30 20 10 5 GRAN QUIVIRA.................... 54 80 55 82 / 30 20 10 10 CARRIZOZO....................... 58 82 58 85 / 20 20 10 20 RUIDOSO......................... 52 75 56 77 / 40 30 20 30 CAPULIN......................... 53 77 51 82 / 20 10 5 10 RATON........................... 50 84 49 88 / 20 10 5 5 SPRINGER........................ 52 83 50 87 / 20 10 5 5 LAS VEGAS....................... 51 81 47 84 / 30 10 10 5 CLAYTON......................... 57 82 59 89 / 30 10 5 10 ROY............................. 56 80 53 86 / 20 10 5 0 CONCHAS......................... 62 88 60 93 / 20 10 5 0 SANTA ROSA...................... 60 87 59 91 / 30 10 5 0 TUCUMCARI....................... 61 86 61 94 / 20 10 5 0 CLOVIS.......................... 59 81 60 91 / 20 20 10 0 PORTALES........................ 62 82 63 90 / 20 20 10 0 FORT SUMNER..................... 62 83 61 91 / 20 20 10 0 ROSWELL......................... 62 88 61 95 / 20 20 10 0 PICACHO......................... 57 84 58 88 / 30 20 10 5 ELK............................. 55 75 58 79 / 30 30 20 30 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1205 PM MDT FRI SEP 11 2015 .AVIATION... 18Z TAF CYCLE MODELS HAVE BEEN TRENDING DOWNWARD ON THE PCPN COVERAGE PROGNOSIS FOR TODAY...PROBABLY BECAUSE THE BACK DOOR COLD FRONT ARRIVED EARLIER THAN EXPECTED. THE FRONT SHOULD REACH THE AZ BORDER THIS AFTN. THE ATMOSPHERE BEHIND THE FRONT IS SIGNIFICANTLY MORE STABLE...BUT THERE SHOULD STILL BE ENOUGH INSTABILITY FOR SCT TO ISOLD TS/SHRA ALONG AND E OF THE CENTRAL MT CHAIN AS WELL AS THE SOUTHERN TIER OF MTS. SOME PRECIP MAY LINGER IN THESE AREAS INTO TONIGHT...BUT THE BIGGER IMPACT WILL BE WDSPR IFR AND MVFR CONDITIONS IN LOW CLOUDS E OF THE CENTRAL MT CHAIN. SOME OF THESE SHOULD EVEN WORK THEIR WAY INTO THE KSAF AREA. ONE TRUSTED MODEL SUGGESTS MVFR CONDITIONS AROUND ALBUQUERQUE TOO...BUT IT IS VERY UNCOMMON FOR KABQ AND KAEG TO DROP BELOW VFR IN THIS PARTICULAR SCENARIO. LOW CLOUDS SHOULD BURN OFF MOST PLACES BY MID TO LATE MORNING ON SATURDAY AS A DEVELOPING LEE TROUGH SHIFTS SFC WINDS OUT OF THE W AND SW. 44 && .PREV DISCUSSION...1149 AM MDT FRI SEP 11 2015... .UPDATE... LATEST HRRR/NAM12/WRF CONTINUE TO TREND MORE STABLE TODAY/TONIGHT WITH QPF DEVELOPMENT JUST ABOUT ALL AREAS. MADE CHANGES TO ADJUST POPS LOWER ALL AREAS THRU TONIGHT. WILL CONSIDER MORE CHANGES WITH LATE AFTERNOON PACKAGE. GUYER && .PREV DISCUSSION...1028 AM MDT FRI SEP 11 2015... .UPDATE... HIGHLY LOCALIZED GAP WIND BELOW TIJERAS CANYON ON THE ABQ EAST SIDE IS PRODUCING EAST WIND GUSTS UP TO 30 KTS AT TIMES THIS MORNING. UPDATED WIND GRIDS TO REFLECT THIS CHANGE FROM EARLIER GUIDANCE THRU REST OF TODAY. THE LATEST HRRR SHOWS THE EFFECT VERY WELL WITH LOCAL OBS PLOT VERIFYING THE MESOSCALE IMPACTS ON THE WIND...WITH A MESO HIGH OVER THE NORTHERN HALF OF ABQ AND A MESOLOW SOUTH OF THE SUNPORT. WINDS ARE LIGHT OVER THE REMAINDER OF THE CITY. EXPECT STRENGTHENING OVER A LARGER PORTION OF THE RIO GRANDE VALLEY THIS EVENING AS THE MAIN FRONTAL BOUNDARY SLIDES INTO THE REGION. GUYER && .PREV DISCUSSION...334 AM MDT FRI SEP 11 2015... .SYNOPSIS... A STRONG BACKDOOR COLD FRONT WILL PUSH RAPIDLY INTO EASTERN AND CENTRAL NEW MEXICO TODAY. THE FRONT WILL BRING COOLER TEMPERATURES AND A GOOD SHOT AT SHOWERS AND THUNDERSTORMS PRIMARILY TO AREAS ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN TODAY AND TONIGHT. ON SATURDAY...SHOWERS AND STORMS WILL FAVOR MOUNTAIN AREAS DURING THE AFTERNOON AND LOWER ELEVATIONS OF CENTRAL AND EASTERN NEW MEXICO DURING THE EVENING. AS A WEAK TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST ON SUNDAY AND MONDAY...SHOWERS AND STORMS WILL FAVOR THE WESTERN HALF OF THE STATE. && .DISCUSSION... BACKDOOR COLD FRONT NEAR A SPRINGER TO NARA VISA LINE AS OF THIS WRITING. MODELS CONTINUE IDEA OF MARCHING THE FRONT SOUTHWEST TO THE EAST SLOPES OF THE CENTRAL MTN CHAIN BY ABOUT SUNRISE AND THEN WWD INTO THE RGV AND POINTS WEST DURING THE DAY. GFS AND NAM BOTH TAKE THE FRONT TO THE DIVIDE BY ABOUT MIDNIGHT AND TO THE AZ LINE EARLY SATURDAY MORNING. GFS AND NAM PROG ABOUT A 12MB DIFFERENCE ACROSS THE STATE SO EAST WINDS INTO THE MID RGV AND ABQ METRO LIKELY TO PEAK IN THE 25 TO 35 MPH RANGE AROUND SUNSET. GFS STILL MUCH MORE BULLISH THAN THE NAM WITH PRECIP TODAY AND TONIGHT. DRY NW FLOW ALOFT EXPECTED TO NOT ONLY GENERATE CONVERGENCE ZONES BUT EXTRA BUOYANCY AS WELL AND THUS FAVORED THE WETTER GFS SOLUTION. RESIDUAL LOW LEVEL MOISTURE EXPECTED TO RESULT IN SCATTERED CONVECTION OVER MOST MTN RANGES SATURDAY AFTERNOON...SPREADING TO LOWER ELEVATIONS OF CENTRAL AND EASTERN NEW MEXICO SATURDAY EVENING. DRY AIR OVER THE NW QUARTER...HOWEVER...WILL KEEP THIS PORTION OF THE FORECAST AREA DRY. GFS AND ECMWF TRENDING SLIGHTLY FASTER WITH THE EWD PROGRESSION OF THE SRN PORTION OF A WEAK UPPER LEVEL LOW JUST OFF THE CENTRAL CALIFORNIA COAST. MODELS AGREE THAT RESIDUAL MOISTURE FROM PRECIP ASSOCIATED WITH THE CURRENT BACKDOOR COLD FRONT WILL COMBINE WITH REMNANT MOISTURE FROM WHAT WAS ONCE TROPICAL STORM/HURRICANE LINDA TO GENERATE GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS OVER WRN NM SUNDAY AFTERNOON AND EVENING AND OVER THE NWRN HALF OF THE STATE MONDAY. GFS AND ECMWF BEGIN TO DIFFER SIGNIFICANTLY BY MID WEEK NEXT WEEK. GFS IS FARTHER SOUTH WITH JET STREAM AND SHORT- WAVE TROUGHS PASSING EWD THROUGH THE NORTHERN ROCKIES AND THE ASSOCIATED DRY WESTERLY FLOW ALOFT OVER NM. ECMWF ON THE OTHER HAND IS FARTHER TO THE NORTH WITH THE JET AND THE FOUR CORNERS HIGH AND BEGINS TO REINTRODUCE A MONSOON MOISTURE PLUME TOWARD THE END OF NEXT WEEK. GIVEN ALL THE CONVECTIVE ACTIVITY IN THE TROPICAL PACIFIC OCEAN AND SEVERAL SYSTEMS TRANSITIONING FROM TROPICAL (WARM CORE) TO EXTRA- TROPICAL (COLD CORE)...FORECASTER CONFIDENCE BEYOND DAY 5 REMAINS LOW. 33 && .FIRE WEATHER... A BACKDOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE FORECAST AREA TODAY RESULTING IN COOLER DAYTIME TEMPERATURES ACROSS CENTRAL AND EASTERN AREAS. HIGHS ARE FORECAST TO BE BELOW NORMAL ACROSS THE EAST CENTRAL AND NORTHEAST PLAINS BEHIND THE FRONT...ACCOMPANIED BY AN UPTREND IN HUMIDITY. BEST CHANCES FOR WETTING RAIN WILL BE ALONG THE CENTRAL MOUNTAIN CHAIN AND ADJACENT HIGHLANDS...BUT ESPECIALLY OVER THE SANGRE DE CRISTOS BY LATE DAY. DRY AND WARM CONDITIONS ACROSS FAR WESTERN PORTIONS OF THE AREA WILL RESULT IN HAINES VALUES OF 5 TODAY. EXCELLENT HUMIDITY RECOVERY IS FORECAST OVERNIGHT MOST AREAS THANKS TO MOISTURE BEHIND THE BACKDOOR FRONT. THE UPPER HIGH IS FORECAST TO WEAKEN OVER THE REGION THROUGH THE WEEKEND...WITH THE UPPER/MID LEVEL FLOW BECOMING WESTERLY AND ALLOWING MOISTURE FROM OVER THE DESERT SOUTHWEST TO TRANSPORT EAST OVER NEW MEXICO. MOIST WESTERLY FLOW WILL RESULT IN A HUMIDITY UPTREND LATE IN THE WEEKEND AND INTO MONDAY...WITH CHANCES FOR WETTING RAIN INCREASING OVER THE WESTERN AND NORTHERN MOUNTAINS. MODERATE WESTERLY FLOW TO PREVAIL FROM TUESDAY THROUGH AT LEAST THURSDAY OF NEXT WEEK WITH INCREASING WINDS AND A GRADUAL DRYING TREND. TEMPERATURES ARE FORECAST TO BE NEAR/BELOW NORMAL WEST AND ABOVE NORMAL CENTRAL AND EAST. 11 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1149 AM MDT FRI SEP 11 2015 .UPDATE... LATEST HRRR/NAM12/WRF CONTINUE TO TREND MORE STABLE TODAY/TONIGHT WITH QPF DEVELOPMENT JUST ABOUT ALL AREAS. MADE CHANGES TO ADJUST POPS LOWER ALL AREAS THRU TONIGHT. WILL CONSIDER MORE CHANGES WITH LATE AFTERNOON PACKAGE. GUYER && .PREV DISCUSSION...1028 AM MDT FRI SEP 11 2015... .UPDATE... HIGHLY LOCALIZED GAP WIND BELOW TIJERAS CANYON ON THE ABQ EAST SIDE IS PRODUCING EAST WIND GUSTS UP TO 30 KTS AT TIMES THIS MORNING. UPDATED WIND GRIDS TO REFLECT THIS CHANGE FROM EARLIER GUIDANCE THRU REST OF TODAY. THE LATEST HRRR SHOWS THE EFFECT VERY WELL WITH LOCAL OBS PLOT VERIFYING THE MESOSCALE IMPACTS ON THE WIND...WITH A MESO HIGH OVER THE NORTHERN HALF OF ABQ AND A MESOLOW SOUTH OF THE SUNPORT. WINDS ARE LIGHT OVER THE REMAINDER OF THE CITY. EXPECT STRENGTHENING OVER A LARGER PORTION OF THE RIO GRANDE VALLEY THIS EVENING AS THE MAIN FRONTAL BOUNDARY SLIDES INTO THE REGION. GUYER && .PREV DISCUSSION...541 AM MDT FRI SEP 11 2015... .AVIATION... 12Z TAF CYCLE VFR CONDITIONS CURRENTLY PREVAIL AND ARE FORECAST TO PERSIST WITH A FEW EXCEPTIONS. A MVFR STRATUS DECK IS FILLING-IN BEHIND A BACKDOOR COLD FRONT ACROSS THE NORTHEAST PLAINS AND WILL IMPACT KLVS AND KTCC THIS MORNING. KLVS AND KTCC BOTH HAVE THE POTENTIAL TO DETERIORATE DOWN TO IFR OVERNIGHT...BUT ONLY MVFR CONDITIONS ARE FORECAST AT THIS TIME. OTHERWISE...MVFR CONDITIONS ARE POSSIBLE IN/NEAR STORMS THIS AFTERNOON AND EVENING WITHIN THE VICINITY OF KSAF...KLVS AND KROW. MODERATE EAST CANYON/GAP WINDS ARE FORECAST TO DEVELOP AT KABQ LATER TODAY WHEN THE BACKDOOR FRONT MAKES A PUSH THROUGH THE CENTRAL MOUNTAIN CHAIN. HIGHEST FORECAST GUSTS AT KABQ CURRENTLY 32KTS...BUT SOME POTENTIAL EXISTS TO HIGH AWW CRITERIA (+35KTS) LATE THIS AFTERNOON AND EVENING. 11 && .PREV DISCUSSION...334 AM MDT FRI SEP 11 2015... .SYNOPSIS... A STRONG BACKDOOR COLD FRONT WILL PUSH RAPIDLY INTO EASTERN AND CENTRAL NEW MEXICO TODAY. THE FRONT WILL BRING COOLER TEMPERATURES AND A GOOD SHOT AT SHOWERS AND THUNDERSTORMS PRIMARILY TO AREAS ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN TODAY AND TONIGHT. ON SATURDAY...SHOWERS AND STORMS WILL FAVOR MOUNTAIN AREAS DURING THE AFTERNOON AND LOWER ELEVATIONS OF CENTRAL AND EASTERN NEW MEXICO DURING THE EVENING. AS A WEAK TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST ON SUNDAY AND MONDAY...SHOWERS AND STORMS WILL FAVOR THE WESTERN HALF OF THE STATE. && .DISCUSSION... BACKDOOR COLD FRONT NEAR A SPRINGER TO NARA VISA LINE AS OF THIS WRITING. MODELS CONTINUE IDEA OF MARCHING THE FRONT SOUTHWEST TO THE EAST SLOPES OF THE CENTRAL MTN CHAIN BY ABOUT SUNRISE AND THEN WWD INTO THE RGV AND POINTS WEST DURING THE DAY. GFS AND NAM BOTH TAKE THE FRONT TO THE DIVIDE BY ABOUT MIDNIGHT AND TO THE AZ LINE EARLY SATURDAY MORNING. GFS AND NAM PROG ABOUT A 12MB DIFFERENCE ACROSS THE STATE SO EAST WINDS INTO THE MID RGV AND ABQ METRO LIKELY TO PEAK IN THE 25 TO 35 MPH RANGE AROUND SUNSET. GFS STILL MUCH MORE BULLISH THAN THE NAM WITH PRECIP TODAY AND TONIGHT. DRY NW FLOW ALOFT EXPECTED TO NOT ONLY GENERATE CONVERGENCE ZONES BUT EXTRA BUOYANCY AS WELL AND THUS FAVORED THE WETTER GFS SOLUTION. RESIDUAL LOW LEVEL MOISTURE EXPECTED TO RESULT IN SCATTERED CONVECTION OVER MOST MTN RANGES SATURDAY AFTERNOON...SPREADING TO LOWER ELEVATIONS OF CENTRAL AND EASTERN NEW MEXICO SATURDAY EVENING. DRY AIR OVER THE NW QUARTER...HOWEVER...WILL KEEP THIS PORTION OF THE FORECAST AREA DRY. GFS AND ECMWF TRENDING SLIGHTLY FASTER WITH THE EWD PROGRESSION OF THE SRN PORTION OF A WEAK UPPER LEVEL LOW JUST OFF THE CENTRAL CALIFORNIA COAST. MODELS AGREE THAT RESIDUAL MOISTURE FROM PRECIP ASSOCIATED WITH THE CURRENT BACKDOOR COLD FRONT WILL COMBINE WITH REMNANT MOISTURE FROM WHAT WAS ONCE TROPICAL STORM/HURRICANE LINDA TO GENERATE GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS OVER WRN NM SUNDAY AFTERNOON AND EVENING AND OVER THE NWRN HALF OF THE STATE MONDAY. GFS AND ECMWF BEGIN TO DIFFER SIGNIFICANTLY BY MID WEEK NEXT WEEK. GFS IS FARTHER SOUTH WITH JET STREAM AND SHORT- WAVE TROUGHS PASSING EWD THROUGH THE NORTHERN ROCKIES AND THE ASSOCIATED DRY WESTERLY FLOW ALOFT OVER NM. ECMWF ON THE OTHER HAND IS FARTHER TO THE NORTH WITH THE JET AND THE FOUR CORNERS HIGH AND BEGINS TO REINTRODUCE A MONSOON MOISTURE PLUME TOWARD THE END OF NEXT WEEK. GIVEN ALL THE CONVECTIVE ACTIVITY IN THE TROPICAL PACIFIC OCEAN AND SEVERAL SYSTEMS TRANSITIONING FROM TROPICAL (WARM CORE) TO EXTRA- TROPICAL (COLD CORE)...FORECASTER CONFIDENCE BEYOND DAY 5 REMAINS LOW. 33 && .FIRE WEATHER... A BACKDOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE FORECAST AREA TODAY RESULTING IN COOLER DAYTIME TEMPERATURES ACROSS CENTRAL AND EASTERN AREAS. HIGHS ARE FORECAST TO BE BELOW NORMAL ACROSS THE EAST CENTRAL AND NORTHEAST PLAINS BEHIND THE FRONT...ACCOMPANIED BY AN UPTREND IN HUMIDITY. BEST CHANCES FOR WETTING RAIN WILL BE ALONG THE CENTRAL MOUNTAIN CHAIN AND ADJACENT HIGHLANDS...BUT ESPECIALLY OVER THE SANGRE DE CRISTOS BY LATE DAY. DRY AND WARM CONDITIONS ACROSS FAR WESTERN PORTIONS OF THE AREA WILL RESULT IN HAINES VALUES OF 5 TODAY. EXCELLENT HUMIDITY RECOVERY IS FORECAST OVERNIGHT MOST AREAS THANKS TO MOISTURE BEHIND THE BACKDOOR FRONT. THE UPPER HIGH IS FORECAST TO WEAKEN OVER THE REGION THROUGH THE WEEKEND...WITH THE UPPER/MID LEVEL FLOW BECOMING WESTERLY AND ALLOWING MOISTURE FROM OVER THE DESERT SOUTHWEST TO TRANSPORT EAST OVER NEW MEXICO. MOIST WESTERLY FLOW WILL RESULT IN A HUMIDITY UPTREND LATE IN THE WEEKEND AND INTO MONDAY...WITH CHANCES FOR WETTING RAIN INCREASING OVER THE WESTERN AND NORTHERN MOUNTAINS. MODERATE WESTERLY FLOW TO PREVAIL FROM TUESDAY THROUGH AT LEAST THURSDAY OF NEXT WEEK WITH INCREASING WINDS AND A GRADUAL DRYING TREND. TEMPERATURES ARE FORECAST TO BE NEAR/BELOW NORMAL WEST AND ABOVE NORMAL CENTRAL AND EAST. 11 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 42
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1028 AM MDT FRI SEP 11 2015 .UPDATE... HIGHLY LOCALIZED GAP WIND BELOW TIJERAS CANYON ON THE ABQ EAST SIDE IS PRODUCING EAST WIND GUSTS UP TO 30 KTS AT TIMES THIS MORNING. UPDATED WIND GRIDS TO REFLECT THIS CHANGE FROM EARLIER GUIDANCE THRU REST OF TODAY. THE LATEST HRRR SHOWS THE EFFECT VERY WELL WITH LOCAL OBS PLOT VERIFYING THE MESOSCALE IMPACTS ON THE WIND...WITH A MESO HIGH OVER THE NORTHERN HALF OF ABQ AND A MESOLOW SOUTH OF THE SUNPORT. WINDS ARE LIGHT OVER THE REMAINDER OF THE CITY. EXPECT STRENGTHENING OVER A LARGER PORTION OF THE RIO GRANDE VALLEY THIS EVENING AS THE MAIN FRONTAL BOUNDARY SLIDES INTO THE REGION. GUYER && .PREV DISCUSSION...541 AM MDT FRI SEP 11 2015... .AVIATION... 12Z TAF CYCLE VFR CONDITIONS CURRENTLY PREVAIL AND ARE FORECAST TO PERSIST WITH A FEW EXCEPTIONS. A MVFR STRATUS DECK IS FILLING-IN BEHIND A BACKDOOR COLD FRONT ACROSS THE NORTHEAST PLAINS AND WILL IMPACT KLVS AND KTCC THIS MORNING. KLVS AND KTCC BOTH HAVE THE POTENTIAL TO DETERIORATE DOWN TO IFR OVERNIGHT...BUT ONLY MVFR CONDITIONS ARE FORECAST AT THIS TIME. OTHERWISE...MVFR CONDITIONS ARE POSSIBLE IN/NEAR STORMS THIS AFTERNOON AND EVENING WITHIN THE VICINITY OF KSAF...KLVS AND KROW. MODERATE EAST CANYON/GAP WINDS ARE FORECAST TO DEVELOP AT KABQ LATER TODAY WHEN THE BACKDOOR FRONT MAKES A PUSH THROUGH THE CENTRAL MOUNTAIN CHAIN. HIGHEST FORECAST GUSTS AT KABQ CURRENTLY 32KTS...BUT SOME POTENTIAL EXISTS TO HIGH AWW CRITERIA (+35KTS) LATE THIS AFTERNOON AND EVENING. 11 && .PREV DISCUSSION...334 AM MDT FRI SEP 11 2015... .SYNOPSIS... A STRONG BACKDOOR COLD FRONT WILL PUSH RAPIDLY INTO EASTERN AND CENTRAL NEW MEXICO TODAY. THE FRONT WILL BRING COOLER TEMPERATURES AND A GOOD SHOT AT SHOWERS AND THUNDERSTORMS PRIMARILY TO AREAS ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN TODAY AND TONIGHT. ON SATURDAY...SHOWERS AND STORMS WILL FAVOR MOUNTAIN AREAS DURING THE AFTERNOON AND LOWER ELEVATIONS OF CENTRAL AND EASTERN NEW MEXICO DURING THE EVENING. AS A WEAK TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST ON SUNDAY AND MONDAY...SHOWERS AND STORMS WILL FAVOR THE WESTERN HALF OF THE STATE. && .DISCUSSION... BACKDOOR COLD FRONT NEAR A SPRINGER TO NARA VISA LINE AS OF THIS WRITING. MODELS CONTINUE IDEA OF MARCHING THE FRONT SOUTHWEST TO THE EAST SLOPES OF THE CENTRAL MTN CHAIN BY ABOUT SUNRISE AND THEN WWD INTO THE RGV AND POINTS WEST DURING THE DAY. GFS AND NAM BOTH TAKE THE FRONT TO THE DIVIDE BY ABOUT MIDNIGHT AND TO THE AZ LINE EARLY SATURDAY MORNING. GFS AND NAM PROG ABOUT A 12MB DIFFERENCE ACROSS THE STATE SO EAST WINDS INTO THE MID RGV AND ABQ METRO LIKELY TO PEAK IN THE 25 TO 35 MPH RANGE AROUND SUNSET. GFS STILL MUCH MORE BULLISH THAN THE NAM WITH PRECIP TODAY AND TONIGHT. DRY NW FLOW ALOFT EXPECTED TO NOT ONLY GENERATE CONVERGENCE ZONES BUT EXTRA BUOYANCY AS WELL AND THUS FAVORED THE WETTER GFS SOLUTION. RESIDUAL LOW LEVEL MOISTURE EXPECTED TO RESULT IN SCATTERED CONVECTION OVER MOST MTN RANGES SATURDAY AFTERNOON...SPREADING TO LOWER ELEVATIONS OF CENTRAL AND EASTERN NEW MEXICO SATURDAY EVENING. DRY AIR OVER THE NW QUARTER...HOWEVER...WILL KEEP THIS PORTION OF THE FORECAST AREA DRY. GFS AND ECMWF TRENDING SLIGHTLY FASTER WITH THE EWD PROGRESSION OF THE SRN PORTION OF A WEAK UPPER LEVEL LOW JUST OFF THE CENTRAL CALIFORNIA COAST. MODELS AGREE THAT RESIDUAL MOISTURE FROM PRECIP ASSOCIATED WITH THE CURRENT BACKDOOR COLD FRONT WILL COMBINE WITH REMNANT MOISTURE FROM WHAT WAS ONCE TROPICAL STORM/HURRICANE LINDA TO GENERATE GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS OVER WRN NM SUNDAY AFTERNOON AND EVENING AND OVER THE NWRN HALF OF THE STATE MONDAY. GFS AND ECMWF BEGIN TO DIFFER SIGNIFICANTLY BY MID WEEK NEXT WEEK. GFS IS FARTHER SOUTH WITH JET STREAM AND SHORT- WAVE TROUGHS PASSING EWD THROUGH THE NORTHERN ROCKIES AND THE ASSOCIATED DRY WESTERLY FLOW ALOFT OVER NM. ECMWF ON THE OTHER HAND IS FARTHER TO THE NORTH WITH THE JET AND THE FOUR CORNERS HIGH AND BEGINS TO REINTRODUCE A MONSOON MOISTURE PLUME TOWARD THE END OF NEXT WEEK. GIVEN ALL THE CONVECTIVE ACTIVITY IN THE TROPICAL PACIFIC OCEAN AND SEVERAL SYSTEMS TRANSITIONING FROM TROPICAL (WARM CORE) TO EXTRA- TROPICAL (COLD CORE)...FORECASTER CONFIDENCE BEYOND DAY 5 REMAINS LOW. 33 && .FIRE WEATHER... A BACKDOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE FORECAST AREA TODAY RESULTING IN COOLER DAYTIME TEMPERATURES ACROSS CENTRAL AND EASTERN AREAS. HIGHS ARE FORECAST TO BE BELOW NORMAL ACROSS THE EAST CENTRAL AND NORTHEAST PLAINS BEHIND THE FRONT...ACCOMPANIED BY AN UPTREND IN HUMIDITY. BEST CHANCES FOR WETTING RAIN WILL BE ALONG THE CENTRAL MOUNTAIN CHAIN AND ADJACENT HIGHLANDS...BUT ESPECIALLY OVER THE SANGRE DE CRISTOS BY LATE DAY. DRY AND WARM CONDITIONS ACROSS FAR WESTERN PORTIONS OF THE AREA WILL RESULT IN HAINES VALUES OF 5 TODAY. EXCELLENT HUMIDITY RECOVERY IS FORECAST OVERNIGHT MOST AREAS THANKS TO MOISTURE BEHIND THE BACKDOOR FRONT. THE UPPER HIGH IS FORECAST TO WEAKEN OVER THE REGION THROUGH THE WEEKEND...WITH THE UPPER/MID LEVEL FLOW BECOMING WESTERLY AND ALLOWING MOISTURE FROM OVER THE DESERT SOUTHWEST TO TRANSPORT EAST OVER NEW MEXICO. MOIST WESTERLY FLOW WILL RESULT IN A HUMIDITY UPTREND LATE IN THE WEEKEND AND INTO MONDAY...WITH CHANCES FOR WETTING RAIN INCREASING OVER THE WESTERN AND NORTHERN MOUNTAINS. MODERATE WESTERLY FLOW TO PREVAIL FROM TUESDAY THROUGH AT LEAST THURSDAY OF NEXT WEEK WITH INCREASING WINDS AND A GRADUAL DRYING TREND. TEMPERATURES ARE FORECAST TO BE NEAR/BELOW NORMAL WEST AND ABOVE NORMAL CENTRAL AND EAST. 11 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
336 PM CDT FRI SEP 11 2015 .DISCUSSION... SHOWER AND THUNDERSTORM ACTIVITY CONTINUES TO COME TO AN END THIS AFTERNOON AFTER THUNDERSTORM ACTIVITY HAS DUMPED 1 TO 2 INCHES OF RAIN MAINLY SOUTH OF A BRENHAM TO CLEVELAND LINE. NORTH OF THAT LINE AREAS HAVE GOTTEN VERY LITTLE RAINFALL AND THOSE ARE THE AREAS THAT NEED IT. AREAS OF W HARRIS CO THAT DO NOT NEED THE RAIN ENDED UP WITH ANYWHERE FROM 3 TO 6 INCHES OF RAIN CAUSING LOCALIZED FLOODING MAINLY ON THE SOUTH MAYDE CREEK. LATEST RADAR TRENDS SHOW PRECIPITATION ENDING BUT ALSO NOTICED GRAVITY WAVES WORKING SOUTH. SURFACE COLD FRONT AT 20Z OR 3PM LOOKS TO BE PUSHING THROUGH N TEXAS WITH A PRE-FRONTAL TROUGH AHEAD OF IT. WATER VAPOR IMAGERY SHOWS A WELL DEVELOPED LONG WAVE TROUGH STRETCHING FROM AN UPPER LOW OVER S HUDSON BAY. ONE ELONGATED TROUGH AXIS STRETCHED W TO E ACROSS THE AREA WITH A SECOND STRONGER TROUGH AXIS THROUGH THE S PLAINS. AMPLIFIED PATTERN WILL SUPPORT COLD FRONTAL PASSAGE THROUGH THE AREA LATE TONIGHT INTO SATURDAY MORNING. POSSIBLE THAT A FEW STORMS COULD FORM ON THE FRONT TONIGHT PER LATEST HRRR MODEL TRENDS SO WILL KEEP SOME RAIN CHANCES IN THE FORECAST. OTHERWISE RAIN CHANCES SHOULD DECREASE THROUGH SATURDAY MORNING WITH A DRIER AIRMASS ARRIVING DURING THE DAY. SURFACE DEWPOINTS COULD DROP INTO THE 40S LATE SATURDAY AFTERNOON AND OVERNIGHT. MIN TEMPS SUNDAY MORNING WILL BE QUITE COOL IN THE LOW 60S FOR MOST AREAS AND PERHAPS 50S FOR AREAS NORTH OF HOUSTON. THE SAME WILL BE POSSIBLE MONDAY. IN OTHER WORDS GET OUT AND ENJOY THE FALL LIKE WEATHER. .EXTENDED FORECAST... THE FORECAST FOR TUE THROUGH FRI NEXT WEEK HAS BEEN CHALLENGING WITH THE GFS REMAINING MOSTLY CONSISTENT AND THEN THE ECMWF PRODUCING EITHER A HURRICANE OR NOW JUST A THUNDERSTORM IN THE GULF. IT DOES LOOK LIKE THE 12Z GFS/ECMWF ARE IN MORE AGREEMENT. BOTH MODELS SHOW THAT A WEAK AREA OF LOW PRESSURE OR COASTAL TROUGH COULD FORM IN THE W GULF AND BAY OF CAMPECHE MONDAY INTO TUESDAY. AS THE SURFACE LOW OR COASTAL TROUGH MOVES NORTH...MOISTURE SHOULD INCREASE OVER THE AREA MID WEEK BUT IT DOES NOT LOOK AS ROBUST AS BEFORE. PRECIP WATER VALUES MAY REACH 1.7-1.8 INCHES INSTEAD OF OVER 2 INCHES IN PRIOR MODEL RUNS. SO RAIN CHANCES WERE TRIMMED A BIT BUT STILL THINK THERE MAY BE A DECENT CHANCE OF AT LEAST SCATTERED SHOWER AND THUNDERSTORM ACTIVITY FOR THE MID WEEK. TEMPERATURES WILL BE MORE CLOSER TO NORMAL WITH HIGH TEMPS IN THE LOW 90S AND LOWS IN THE 70S. WITH ALL THAT SAID...CONFIDENCE IS PRETTY LOW THAT THERE WILL BE ANY TROPICAL DEVELOPMENT BASED ON CURRENT FORECAST TRENDS. 39 && .AVIATION... BACK EDGE OF THIS MORNINGS PCPN MAKING SLOW PROGRESS SWD WITH IFR TO LIFR CIGS PERSISTING OVER THE SRN SITES. ALSO STILL SEEING ISO SHRAS REDEVELOPING OVER THE NRN HALF OF THE CWA (ALONG THE PREFRONTAL TROF SLOWLY NUDGING IN FROM THE NORTH). LIGHT NORTH WINDS EXPECTED IN THE WAKE OF THIS BOUNDARY THIS EVE AS IT MOVES TOWARD THE COAST. HOWEVER WITH THE ACTUAL COLD FRONT LAGGING THIS INITIAL LINE BY A FEW HRS... WE COULD SEE SOME BRIEF PATCHY BR DEVELOP OVERNIGHT. OTHERWISE...VFR CONDITIONS TO PREVAIL ONCE THIS PCPN MOVES OUT. 41 && .MARINE... WIDESPREAD SHOWERS/THUNDERSTORMS TO PERSIST ACROSS THE MARINE WATERS THIS EVENING AS THE STRONG DISTURBANCE MOVES OFFSHORE. RAIN CHC WILL LIKELY LINGER OVERNITE AS THE PREFRONTAL TROF APPROACHES FROM THE N. THE MAIN COLD FRONT IS STILL PROGGED TO PUSH OFFSHORE EARLY SAT MORN WITH LIGHT/MODERATE NE FLOW DEVELOPING SAT AFTN THRU SUN. AS THE SFC HIGH NUDGES EAST OF THE STATE...WE SHOULD EXPECT A MORE EASTERLY LOW LEVEL FLOW BY SUN NIGHT. MARINE WINDS TO BECOME MORE SELY DURING THE START OF NEXT WEEK WITH PERIODS OF UNSETTLED WX RETURNING AS WELL. 41 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 73 87 61 87 64 / 30 10 10 0 0 HOUSTON (IAH) 73 88 61 85 64 / 20 10 10 0 0 GALVESTON (GLS) 77 87 73 84 74 / 30 20 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39 AVIATION/MARINE...41