Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/19/15


AREA FORECAST DISCUSSION
NWS TUCSON AZ
859 AM MST THU SEP 17 2015 .SYNOPSIS...EXPECT MAINLY DRY CONDITIONS ACROSS MUCH OF THE AREA THROUGH FRIDAY ALTHOUGH AND ISOLATED THUNDERSTORM WILL BE POSSIBLE OVER COCHISE COUNTY. A CHANCE OF SHOWERS AND THUNDERSTORMS GENERALLY EAST OF TUCSON WILL RETURN THIS WEEKEND...THEN MORE WIDESPREAD MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK. TEMPERATURES WILL BE NEAR SEASONAL NORMALS THROUGH THIS WEEKEND...THEN LOWERING TO BELOW NORMAL VALUES BY TUESDAY. && .DISCUSSION...A GORGEOUS MORNING ACROSS SOUTHEAST ARIZONA WITH JUST A FEW MID-LEVEL CLOUDS FROM TUCSON AND POINTS EAST. TEMPERATURES WERE JUST ABOUT UNCHANGED FROM THIS TIME YESTERDAY...WHILE DEWPOINTS WERE 2 TO 8 DEGS F DRIER. THE 12Z KTWC SOUNDING CONTINUES TO SHOW AN UNSUPPORTIVE ATMOSPHERE FOR CONVECTION TODAY EVEN THOUGH THE PWAT VALUE OF 1.20 INCH IS STILL ABOVE NORMAL. THE MEAGER MOISTURE PRESENT IS ALL CONFINED BELOW 700 MB WITH YET ANOTHER RECORD WARM TEMPERATURE OF -2.5 DEGS C AT 500 MB PER THE SPC SOUNDING CLIMATOLOGY PAGE. THAT SAID...FORECAST SOUNDINGS ACROSS PARTS OF COCHISE COUNTY SHOW JUST ENOUGH LOW-LEVEL MOISTURE TO SUPPORT PERHAPS A SHOWER OR TWO LATE THIS AFTERNOON. THIS NOTION IS BACKED UP BY THE RECENT 17/14Z HRRR AND THE 17/12Z UNIV. OF AZ WRF-NAM. WE`RE CARRYING LOW-END SLIGHT CHANCE POPS THERE SO NO UPDATES WILL BE NECESSARY THIS MORNING. MORE ON THE POTENTIAL RETURN OF MOISTURE AND PRECIPITATION CHANCES THIS WEEKEND AND EARLY NEXT WEEK IN THE AFTEROON PACKAGE. && .AVIATION...VALID THRU 18/18Z. FEW CLOUDS AT 10-14 KFT AGL WITH FEW-SCT CUMULUS RE-DEVELOPING AT 6- 9 KFT AGL THROUGH THIS MORNING. AN ISOLATED -SHRA/-TSRA MAY OCCUR THIS AFTERNOON OVER COCHISE COUNTY. WINDS WILL GENERALLY BE LIGHT AND TERRAIN DRIVEN THIS MORNING...THEN BECOME SW AT 10-15 KTS WITH A FEW GUSTS TO 25 MPH THIS AFTERNOON. ANY GUSTINESS WILL SUBSIDE QUICKLY AFTER 18/01Z WITH SURFACE WINDS BECOMING LIGHT AND TERRAIN DRIVEN OVERNIGHT. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...GENERALLY DRY CONDITIONS ARE EXPECTED THROUGH FRIDAY ALTHOUGH AN ISOLATED SHOWER/THUNDERSTORM CANNOT BE RULED OUT SOUTH AND EAST OF TUCSON. A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY EAST OF TUCSON WILL RETURN THIS WEEKEND...THEN MORE WIDESPREAD MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK. SOUTHWEST WINDS...OCCASIONALLY GUSTY DURING THE AFTERNOON WILL PREVAIL THE NEXT SEVERAL DAYS. OTHERWISE...20-FOOT WINDS WILL GENERALLY BE LESS THAN 15 MPH. && .PREV DISCUSSION...A DRY WESTERLY FLOW WILL CONTINUE TO PROVIDE THE AREA WITH SEASONABLE DAYTIME TEMPERATURES THROUGH FRIDAY. THEREAFTER...MODELS SUGGEST THE FLOW PATTERN WILL CHANGE THIS WEEKEND AS THE WESTERLY FLOW BEGINS TO BECOME MORE SOUTHERLY. THIS WILL RESULT IN AN INCREASE IN MOISTURE...ESPECIALLY FROM TUCSON EASTWARD. AS A RESULT...THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE WEEKEND...MAINLY EAST OF TUCSON. A MORE SIGNIFICANT CHANGE WAS PROGGED EARLY NEXT WEEK AS DEEPER MOISTURE SPREADS NORTHWARD THROUGH BAJA AND INTO THE DESERT SOUTHWEST. THIS INCREASE IN MOISTURE WAS ASSOCIATED WITH A LOW PRESSURE SYSTEM APPROACHING THE SOUTHERN CALIFORNIA COAST. THE END RESULT WILL BE INCREASING CHANCES OF RAIN MONDAY INTO EARLY WEDNESDAY WITH THE BEST CHANCE ON TUESDAY AS THE LOW PRESSURE SYSTEM ENTERS ARIZONA. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && $$ CARLAW VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1112 PM EDT FRI SEP 18 2015 .SYNOPSIS... HIGH PRESSURE WILL GRADUALLY SLIDE EASTWARD THROUGH SATURDAY. A COLD FRONT WILL MOVES THROUGH LATE SATURDAY NIGHT AND SUNDAY MORNING. HIGH PRESSURE WILL THEN BUILD TO THE NORTH EARLY NEXT WEEK...AND THEN TO THE NORTHEAST INTO THE MIDDLE OF THE WEEK...WHILE LOW PRESSURE MEANDERS OFF THE SOUTHEAST COAST. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... THE FORECAST REMAINS MAINLY ON TRACK. SOME PATCHY FOG HAS DEVELOPED ACROSS OF EASTERN LONG ISLAND AND EXPECT THIS TO CONTINUE THROUGH THE REST OF THE NIGHT WHERE BETTER COOLING TAKES PLACE. TEMPERATURES WERE SLIGHTLY ADJUSTED DOWN. OTHERWISE...NO OTHER REMARKABLE CHANGES MADE. THE HIGH WILL SLIDE E AND WEAKEN AS A COLD FRONT APPROACHES FROM THE WEST...AND AS LOW PRESSURE SLOWLY MOVES UP THE COAST. SKIES WILL BE CLEAR TONIGHT...AND WITH LIGHT ONSHORE FLOW CONTINUING...SHOULD SEE DEVELOPMENT OF FOG MAINLY AWAY FROM NYC LATE TONIGHT INTO EARLY SAT MORNING. LOWS IN THE VALLEYS OF ORANGE COUNTY AND THE LONG ISLAND PINE BARRENS WILL BE 55-60...WITH 60S ELSEWHERE. KEPT LOWS AROUND 60 ACROSS THE INTERIOR DESPITE AFTERNOON DEWPOINTS IN THE MID 50S SINCE AIR MASS WILL BE SLOWLY MOISTENING TONIGHT IN THE ONSHORE FLOW. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... THE 12Z NAM AND NOW 12Z RAP ARE INDICATING AREA OF ISENTROPIC LIFT...WITH CLOUDS/SHOWERS...MOVING UP THE NJ COAST TOWARD WRN LONG ISLAND/CT AND SKIRTING NYC. NAM QPF OVERDONE BUT NOW THINK THIS IS AT LEAST WORTH A SLIGHT CHANCE MENTION FOR SAT MORNING. OTHERWISE...MOSTLY SUNNY SKIES ON SAT SHOULD LEAD TO HIGH TEMPS A COUPLE DEG HIGHER THAN COMPOSITE MOS GUIDANCE AND SIMILAR TO THOSE OF TODAY...WITH LOWER/MID 80S. A COLD FRONT WILL BEGIN TO MOVE ACROSS LATE SAT NIGHT. LIFT LOOKS WEAK AND DEEP MOISTURE IS LACKING...SO WILL CONTINUE TO CARRY SLIGHT TO LOW CHANCE POP. LOWS WILL BE MAINLY IN THE 60S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... NORTHERN STREAM SHORTWAVE PIVOTS THROUGH SOUTHEASTERN CANADA ON SUNDAY/SUNDAY NIGHT. THEREAFTER MODELS IN FAIRLY GOOD AGREEMENT WITH A SPLIT FLOW DEVELOPING FOR EARLY TO MID NEXT WEEK AS SHORTWAVE ENERGY ENTERING THE PAC NW COAST DIGS THROUGH THE GREAT LAKES INTO THE SE US EARLY NEXT WEEK. PART OF THIS ENERGY SEPARATES ITSELF FROM THE NORTHERN STREAM AND CUTS OFF OVER THE SE US FOR THE MID TO LATE WEEK PERIOD...WHILE THE REST SWINGS THROUGH THE NORTHEAST DURING THE MIDWEEK PERIOD. SOME UNCERTAINTY IN THE FORECAST LIES IN THE INTERACTION OF THE DIGGING EASTERN TROUGH WITH PIECES OF SUB-TROPICAL ENERGY ROUNDING DOMINANT ATLANTIC RIDGING...AND HOW CLOSE TO THE COAST THIS MOISTURE/ENERGY MAY GET FOR MUCH OF THE WEEK. IN TERMS OF SENSIBLE WEATHER...A MOISTURE STARVED COLD FRONT WITH SHORTWAVE ENERGY WELL TO THE NW PASSES EAST OF THE REGION SUNDAY MORNING. A FEW LINGERING SHOWERS POSSIBLE SUNDAY MORNING...OTHERWISE A COOLER AND DRIER AIRMASS BEGINS ADVECTING INTO THE REGION ON BREEZY NORTHERLY FLOW ON SUNDAY. TEMPS SUNDAY SHOULD BE NEAR SEASONABLE. AS HIGH PRESSURE CONTINUES TO BUILD THROUGH AND EAST OF NEW ENGLAND EARLY TO MID NEXT WEEK...A BREEZY NE FLOW WILL PERSIST AND MAINTAIN A MAINLY DRY BUT SEASONABLY COOL CANADIAN MARITIMES AIRMASS OVER THE REGION. THE TIGHT GRADIENT WILL BE COURTESY OF A SERIES OF LOWS DRIFTING NE WELL OFF THE EAST COAST. AS MENTIONED BEFORE...UNCERTAINTY EXISTS ON EXACT EVOLUTION OF THESE OFFSHORE LOW/S INTO MIDWEEK...BUT NHC SEES A MEDIUM POTENTIAL FOR SOME SORT OF TROPICAL/SUB-TROPICAL DEVELOPMENT OVER THE NEXT 5 DAYS. THERE IS CURRENTLY A SLIGHT POTENTIAL FOR THE REGION TO AFFECTED BY SOME SHOWER ACTIVITY MIDWEEK AS THE EARLIER MENTIONED NORTHERN STREAM SHORTWAVE APPROACHES/SWINGS THROUGH...BUT THIS WILL ULTIMATELY BE DEPENDENT ON EVOLUTION OF THE OFFSHORE LOW PRESSURE/S AND STRENGTH OF UPPER CONFLUENCE/SURFACE RIDGING OVER THE NE. OTHERWISE...THE SAME MIDWEEK PATTERN COULD PERSIST THROUGH THE WEEK IN THE CONTINUED SPLIT FLOW REGIME...WITH THE REGION IN BETWEEN NORTHERN STREAM FLOW WELL TO THE NORTH...A BROAD CUTOFF LOW TO THE SOUTH...AND DOMINANT OFFSHORE RIDGING TO THE SE. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE REMAINS OFFSHORE INTO SATURDAY AS A COLD FRONT APPROACHES FROM THE WEST. VFR THROUGH AT LEAST 04Z. STARTING TO SEE SOME CONVERGENCE OF SOLNS THAT THE WORST OF THE FOG/STRATUS SHOULD BE CONFINED TO CT TERMINALS AND PERHAPS KHPN. STILL NOT SURE ABOUT THE EXTENT OF THE STRATUS BUT GAINING INCREASING CONFIDENCE THAT WIDESPREAD MVFR TO LOCALLY IFR OR LOWER FOG IS A GOOD POSSIBILITY. ALREADY SEEING STRATUS DEVELOPMENT TO THE EAST ACROSS THE CAPE AND ISLANDS AND A PATCH IN SE CT...BUT LOW LEVEL FLOW IS SW WHICH IS NOT IDEAL SO UNSURE HOW FAR W IT WILL GET. ADJUSTED 03Z TAFS SLIGHTLY BASED ON THESE TRENDS. LATEST HI RES MODELS HAVE BACKED OFF ON ANY PCPN EARLY SAT MORNING. .OUTLOOK FOR 00Z SATURDAY THROUGH WEDNESDAY... .SAT NIGHT...VFR. CHC OF WIDELY SCT SHOWERS WITH COLD FROPA. .SUN-TUE...MAINLY VFR. CHC SUB-VFR TUE. N-NE GUSTS 20-25KT POSSIBLE AT COASTAL TERMINALS. .WED...VFR. && .MARINE... CONDITIONS ACROSS THE AREA WATERS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH SATURDAY...AS HIGH PRESSURE MOVES OFFSHORE. SCA WIND GUSTS POSSIBLE SUNDAY AFTERNOON FOR ALL WATERS IN WAKE OF COLD FRONTAL PASSAGE...BUT BETTER POTENTIAL FOR SCA DEVELOPS SUNDAY NIGHT AND LIKELY THROUGH EARLY NEXT WEEK ESPECIALLY ON THE OCEAN WITH DEVELOPMENT OF A PERSISTENT E/NE FLOW. OCEAN SEAS COULD BUILD TO 6 TO 8 FT FOR EARLY NEXT WEEK...USUALLY UNDER-PREDICTED IN WNA GUIDANCE. WINDS MAY ALSO GUST CLOSE TO 25 KT DURING THIS TIME ACROSS ALL WATERS. && .FIRE WEATHER... FUEL MOISTURE LEVELS WILL LIKELY CONTINUE TO DECREASE THROUGH THE WEEKEND WITH THE UNSEASONABLY WARM AND DRY WEATHER. CURRENTLY KBDI VALUES ARE GREATER THAN 300 OVER A GOOD PORTION OF THE REGION. DEPENDING ON COVERAGE OF LIGHT RAINFALL WITH COLD FRONTAL PASSAGE SAT NIGHT/EARLY SUN...PREDECESSOR DRY CONDS WITH A GUSTY N FLOW AND LOW RH VALUES MAY RESULT IN AN ENHANCED FIRE WEATHER THREAT ON SUNDAY. && .HYDROLOGY... DRY CONDITIONS EXPECTED THROUGH SATURDAY WITH NO WIDESPREAD SIGNIFICANT PRECIPITATION EXPECTED THROUGH NEXT WEEK. && .TIDES/COASTAL FLOODING... THERE IS THE POSSIBILITY FOR MINOR COASTAL FLOODING DURING THE MON-FRI TIMEFRAME DUE TO THE FORECAST OF PROLONGED E-NE FLOW. POTENTIAL FOR IMPACTS APPEARS LOW FOR MON...BUT MAY INCREASE IN THE TYPICALLY VULNERABLE LOCALES FOR THE MID TO LATE WEEK PERIOD WITH GRADUALLY RISING ASTRONOMICAL HIGH TIDES. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...GOODMAN/NV NEAR TERM...GOODMAN/JM SHORT TERM...GOODMAN LONG TERM...NV AVIATION...24 MARINE...GOODMAN/NV FIRE WEATHER... HYDROLOGY...GOODMAN/NV TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
815 PM EDT FRI SEP 18 2015 .SYNOPSIS... HIGH PRESSURE WILL GRADUALLY SLIDE EASTWARD THROUGH SATURDAY. A COLD FRONT WILL MOVES THROUGH LATE SATURDAY NIGHT AND SUNDAY MORNING. HIGH PRESSURE WILL THEN BUILD TO THE NORTH EARLY NEXT WEEK...AND THEN TO THE NORTHEAST INTO THE MIDDLE OF THE WEEK...WHILE LOW PRESSURE MEANDERS OFF THE SOUTHEAST COAST. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... THE FORECAST IS MAINLY ON TRACK. ADJUSTED DEWPOINTS SLIGHTLY DOWNWARD TO BETTER MATCH OBSERVED TRENDS NEAR NYC AND NORTHWEST. OTHERWISE...NO OTHER REMARKABLE CHANGES MADE. THE HIGH WILL SLIDE E AND WEAKEN AS A COLD FRONT APPROACHES FROM THE WEST...AND AS LOW PRESSURE SLOWLY MOVES UP THE COAST. SKIES WILL BE CLEAR TONIGHT...AND WITH LIGHT ONSHORE FLOW CONTINUING...SHOULD SEE DEVELOPMENT OF FOG MAINLY AWAY FROM NYC LATE TONIGHT INTO EARLY SAT MORNING. LOWS IN THE VALLEYS OF ORANGE COUNTY AND THE LONG ISLAND PINE BARRENS WILL BE 55-60...WITH 60S ELSEWHERE. KEPT LOWS AROUND 60 ACROSS THE INTERIOR DESPITE AFTERNOON DEWPOINTS IN THE MID 50S SINCE AIR MASS WILL BE SLOWLY MOISTENING TONIGHT IN THE ONSHORE FLOW. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... THE 12Z NAM AND NOW 12Z RAP ARE INDICATING AREA OF ISENTROPIC LIFT...WITH CLOUDS/SHOWERS...MOVING UP THE NJ COAST TOWARD WRN LONG ISLAND/CT AND SKIRTING NYC. NAM QPF OVERDONE BUT NOW THINK THIS IS AT LEAST WORTH A SLIGHT CHANCE MENTION FOR SAT MORNING. OTHERWISE...MOSTLY SUNNY SKIES ON SAT SHOULD LEAD TO HIGH TEMPS A COUPLE DEG HIGHER THAN COMPOSITE MOS GUIDANCE AND SIMILAR TO THOSE OF TODAY...WITH LOWER/MID 80S. A COLD FRONT WILL BEGIN TO MOVE ACROSS LATE SAT NIGHT. LIFT LOOKS WEAK AND DEEP MOISTURE IS LACKING...SO WILL CONTINUE TO CARRY SLIGHT TO LOW CHANCE POP. LOWS WILL BE MAINLY IN THE 60S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... NORTHERN STREAM SHORTWAVE PIVOTS THROUGH SOUTHEASTERN CANADA ON SUNDAY/SUNDAY NIGHT. THEREAFTER MODELS IN FAIRLY GOOD AGREEMENT WITH A SPLIT FLOW DEVELOPING FOR EARLY TO MID NEXT WEEK AS SHORTWAVE ENERGY ENTERING THE PAC NW COAST DIGS THROUGH THE GREAT LAKES INTO THE SE US EARLY NEXT WEEK. PART OF THIS ENERGY SEPARATES ITSELF FROM THE NORTHERN STREAM AND CUTS OFF OVER THE SE US FOR THE MID TO LATE WEEK PERIOD...WHILE THE REST SWINGS THROUGH THE NORTHEAST DURING THE MIDWEEK PERIOD. SOME UNCERTAINTY IN THE FORECAST LIES IN THE INTERACTION OF THE DIGGING EASTERN TROUGH WITH PIECES OF SUB-TROPICAL ENERGY ROUNDING DOMINANT ATLANTIC RIDGING...AND HOW CLOSE TO THE COAST THIS MOISTURE/ENERGY MAY GET FOR MUCH OF THE WEEK. IN TERMS OF SENSIBLE WEATHER...A MOISTURE STARVED COLD FRONT WITH SHORTWAVE ENERGY WELL TO THE NW PASSES EAST OF THE REGION SUNDAY MORNING. A FEW LINGERING SHOWERS POSSIBLE SUNDAY MORNING...OTHERWISE A COOLER AND DRIER AIRMASS BEGINS ADVECTING INTO THE REGION ON BREEZY NORTHERLY FLOW ON SUNDAY. TEMPS SUNDAY SHOULD BE NEAR SEASONABLE. AS HIGH PRESSURE CONTINUES TO BUILD THROUGH AND EAST OF NEW ENGLAND EARLY TO MID NEXT WEEK...A BREEZY NE FLOW WILL PERSIST AND MAINTAIN A MAINLY DRY BUT SEASONABLY COOL CANADIAN MARITIMES AIRMASS OVER THE REGION. THE TIGHT GRADIENT WILL BE COURTESY OF A SERIES OF LOWS DRIFTING NE WELL OFF THE EAST COAST. AS MENTIONED BEFORE...UNCERTAINTY EXISTS ON EXACT EVOLUTION OF THESE OFFSHORE LOW/S INTO MIDWEEK...BUT NHC SEES A MEDIUM POTENTIAL FOR SOME SORT OF TROPICAL/SUB-TROPICAL DEVELOPMENT OVER THE NEXT 5 DAYS. THERE IS CURRENTLY A SLIGHT POTENTIAL FOR THE REGION TO AFFECTED BY SOME SHOWER ACTIVITY MIDWEEK AS THE EARLIER MENTIONED NORTHERN STREAM SHORTWAVE APPROACHES/SWINGS THROUGH...BUT THIS WILL ULTIMATELY BE DEPENDENT ON EVOLUTION OF THE OFFSHORE LOW PRESSURE/S AND STRENGTH OF UPPER CONFLUENCE/SURFACE RIDGING OVER THE NE. OTHERWISE...THE SAME MIDWEEK PATTERN COULD PERSIST THROUGH THE WEEK IN THE CONTINUED SPLIT FLOW REGIME...WITH THE REGION IN BETWEEN NORTHERN STREAM FLOW WELL TO THE NORTH...A BROAD CUTOFF LOW TO THE SOUTH...AND DOMINANT OFFSHORE RIDGING TO THE SE. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE REMAINS OFFSHORE INTO SATURDAY AS A COLD FRONT APPROACHES FROM THE WEST. VFR THROUGH AT LEAST 04Z. LOW CONFIDENCE IN THE EXTENT OF FOG/STRATUS OVERNIGHT AS ALL HI RES GUIDANCE HAS VARYING SOLNS. THEREFORE HAVE MAINTAINED PREVIOUS FORECAST AND WILL MONITOR TO SEE IF A TREND BEGINS TO DEVELOP IN THE GUIDANCE. ANOTHER POTENTIAL FLY IN THE OINTMENT IS SEVERAL OF THE HI RES MODELS ARE INDICATING SOME SHOWERS EARLY SAT MORNING. HAVE LOW CONFIDENCE IN THIS OCCURRING SO HAVE LEFT OUT FOR NOW. WILL MONITOR THIS AS WELL. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: POTENTIAL FOR MVFR OR IFR FOG/STRATUS MAINLY BETWEEN 09Z AND 14Z. KLGA FCSTER COMMENTS: POTENTIAL FOR MVFR OR IFR FOG/STRATUS MAINLY BETWEEN 09Z AND 14Z. KEWR FCSTER COMMENTS: POTENTIAL FOR MVFR OR IFR FOG/STRATUS MAINLY BETWEEN 09Z AND 14Z. KTEB FCSTER COMMENTS: POTENTIAL FOR MVFR OR IFR FOG/STRATUS MAINLY BETWEEN 09Z AND 14Z. KHPN FCSTER COMMENTS: POTENTIAL FOR IFR FOG/STRATUS MAINLY BETWEEN 09Z AND 14Z. KISP FCSTER COMMENTS: POTENTIAL FOR IFR FOG/STRATUS MAINLY BETWEEN 09Z AND 14Z. .OUTLOOK FOR 00Z SATURDAY THROUGH WEDNESDAY... .SAT NIGHT...VFR. CHC OF WIDELY SCT SHOWERS WITH COLD FROPA. .SUN-TUE...MAINLY VFR. CHC SUB-VFR TUE. N-NE GUSTS 20-25KT POSSIBLE AT COASTAL TERMINALS. .WED...VFR. && .MARINE... CONDITIONS ACROSS THE AREA WATERS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH SATURDAY...AS HIGH PRESSURE MOVES OFFSHORE. SCA WIND GUSTS POSSIBLE SUNDAY AFTERNOON FOR ALL WATERS IN WAKE OF COLD FRONTAL PASSAGE...BUT BETTER POTENTIAL FOR SCA DEVELOPS SUNDAY NIGHT AND LIKELY THROUGH EARLY NEXT WEEK ESPECIALLY ON THE OCEAN WITH DEVELOPMENT OF A PERSISTENT E/NE FLOW. OCEAN SEAS COULD BUILD TO 6 TO 8 FT FOR EARLY NEXT WEEK...USUALLY UNDER-PREDICTED IN WNA GUIDANCE. WINDS MAY ALSO GUST CLOSE TO 25 KT DURING THIS TIME ACROSS ALL WATERS. && .FIRE WEATHER... FUEL MOISTURE LEVELS WILL LIKELY CONTINUE TO DECREASE THROUGH THE WEEKEND WITH THE UNSEASONABLY WARM AND DRY WEATHER. CURRENTLY KBDI VALUES ARE GREATER THAN 300 OVER A GOOD PORTION OF THE REGION. DEPENDING ON COVERAGE OF LIGHT RAINFALL WITH COLD FRONTAL PASSAGE SAT NIGHT/EARLY SUN...PREDECESSOR DRY CONDS WITH A GUSTY N FLOW AND LOW RH VALUES MAY RESULT IN AN ENHANCED FIRE WEATHER THREAT ON SUNDAY. && .HYDROLOGY... DRY CONDITIONS EXPECTED THROUGH SATURDAY WITH NO WIDESPREAD SIGNIFICANT PRECIPITATION EXPECTED THROUGH NEXT WEEK. && .TIDES/COASTAL FLOODING... THERE IS THE POSSIBILITY FOR MINOR COASTAL FLOODING DURING THE MON-FRI TIMEFRAME DUE TO THE FORECAST OF PROLONGED E-NE FLOW. POTENTIAL FOR IMPACTS APPEARS LOW FOR MON...BUT MAY INCREASE IN THE TYPICALLY VULNERABLE LOCALES FOR THE MID TO LATE WEEK PERIOD WITH GRADUALLY RISING ASTRONOMICAL HIGH TIDES. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...GOODMAN/NV NEAR TERM...GOODMAN/JM SHORT TERM...GOODMAN LONG TERM...NV AVIATION...24 MARINE...GOODMAN/NV FIRE WEATHER... HYDROLOGY...GOODMAN/NV TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
907 AM EDT THU SEP 17 2015 .SYNOPSIS... HIGH PRESSURE OVER THE AREA WILL MOVE SLOWLY EASTWARD THROUGH SATURDAY. A WEAK COLD FRONT WILL THEN CROSS THE REGION SATURDAY NIGHT INTO SUNDAY MORNING. HIGH PRESSURE WILL THEN BUILD OVER NEW ENGLAND ON SUNDAY AND MONDAY, WITH LOW PRESSURE DEVELOPING NEAR THE CAROLINA COAST ON TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... MORNING 12Z SOUNDINGS MAXT SUGGESTIONS ARE 80-85 (SANS ELEVATION AND SEA BREEZE EFFECTS) FOR THIS AFTERNOON. SO NO BIG CHANGES TO PREDICTED HIGH TEMPS. LAST COUPLE OF HRRR RUNS ARE SLIGHTLY STRONGER WITH THE SEA BREEZE CIRCULATION. WE BLENDED THEM AND CONTINUITY. A 1024 MB SURFACE HIGH WAS STILL OVER THE MID-ATLANTIC REGION THIS MORNING. IR SATELLITE SHOWS SOME HIGH CLOUDS STREAMING OVER SRN NJ/DE IN ASSOCIATED WITH AN UPPER-LEVEL JET STREAK TO OUR SOUTH. THIS IS SLOWLY EASING OFFSHORE. THE CENTER OF THE SURFACE HIGH IS FORECAST TO PROGRESS OFFSHORE THIS AFTERNOON, BUT OUR REGION WILL STILL BE UNDER THE INFLUENCE OF HIGH PRESSURE. ENSUING SOUTHERLY RETURN FLOW ON THE WESTERN PERIPHERY OF THE RIDGE WILL BE VERY LIGHT BUT ACTUALLY PRODUCE A MODEST CAA PATTERN AS 1) THE CORE OF THE WARMER AIR PROGRESS FARTHER DOWNSTREAM OFF THE NEW ENGLAND COAST AND 2) COOLER AIR ASSOCIATED WITH AN UPPER SHORTWAVE TROUGH MOVES OVERHEAD. ACCORDINGLY, EXPECT A REPEAT OF YESTERDAY WX WISE THOUGH MAX TEMPS MAY BE 1-2F COOLER THIS AFTERNOON THAN YESTERDAY. SUNNY SKIES AND LIGHT WINDS CAN ALSO BE EXPECTED. THE AIRMASS WILL REMAIN DRY WITH DEWPOINTS DROPPING INTO THE LOWER 50S INLAND BY THE AFTERNOON. DEWPOINTS IN THE 60S ARE FAVORED CLOSER TO THE COAST WITH A SEA-BREEZE FRONT MOVING INLAND THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/... THE HIGH WILL MOVE FARTHER OFFSHORE TONIGHT BUT THE NORTHEAST AND MID-ATLANTIC STATES REMAIN ON THE WESTERN PERIPHERY OF THE HIGH. THE GRADIENT OVER OUR AREA LOOKS TO BE WEAK ENOUGH FOR WINDS TO GO CALM AS THE BOUNDARY LAYER DECOUPLES. WENT A FEW DEGREES BELOW STAT GUIDANCE FOR MIN TEMPS (LOW TO MID 50S) IN THE RURAL VALLEYS AND PINE BARRENS...THE AREAS THAT TYPICALLY RADIATE EFFECTIVELY. RADIATIONAL FOG IS ONCE AGAIN EXPECTED IN THESE AREAS. FOR THE URBAN AND COASTAL AREAS, FORECAST LOWS ARE IN THE 60S. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... HIGH PRES OVER THE REGION WILL BEGIN TO MOVE OFFSHORE ON FRI. HOWEVER, ANOTHER NICE DAY IS EXPECTED WITH DRY AND WARM, BUT PLEASANT CONDS. MEANWHILE A LARGE LOW PRES SYS NEAR JAMES BAY WILL PUS EWD, WITH ITS ATTENDANT CDFNT EXTENDING SWWD ACRS THE CNTRL PLAINS. SECONDARY LOW PRES IS EXPECTED TO DEVELOP ALG THIS CDFNT, AND MOVE NEWD TO SOMEWHERE NR THE GRTLKS BY SAT MRNG. HOWEVER, WE WILL STILL BE INFLUENCED BY THE HIGH PRES TO THE E. THE AFOREMENTIONED CDFNT WILL CONTINUE TO MOVE EWD, WITH THE LOW PRES MOVG INTO SERN CAN. BY THE TIME IT REACHES OUR AREA SAT NIGHT INTO ERLY SUN, THERE WILL HARDLY BE ANY MOISTURE WITH IT AT ALL. IT IS PSBL THE FRONT COMES THRU COMPLETELY DRY, THOUGH ITS ALSO PSBL THERE ARE AT LEAST A FEW SHWRS, MAINLY TO THE N. SO HAVE LEFT SOME LOW POPS IN THESE AREAS. BEHIND THE FRONT, HIGH PRES BUILDS TO OUR N FOR LATER SUN INTO MON AND SOME SEMBLANCE OF LOW PRES WILL TAKE SHAPE OFF THE SERN CONUS CST. ADDITIONALLY, AN H5 TROF BEGINS TO DEVELOP NR THE GRTLKS. SUN LOOKS DRY ATTM. THE POSN OF THE HIGH WILL PUT US IN A NELY FLOW AND BRING QUITE A BIT OF CLOUDS, BUT EXACTLY HOW THESE FEATURES INTERACT AND WHERE ANY POTENTIAL LOW IS WILL DETERMINE IF AND WHERE THERE IS RAIN ON MON. THE GFS HAS A WEAKER MORE ELY POSN LOW AND KEEPS THE PRECIP MORE CONFINED TO COASTAL AREAS. THE ECMWF IS STRONGER WITH THE LOW AND FURTHER W AND THE NELY FLOW BRINGS SOME MOISTURE ONSHORE. THE MDLS HAVE BEEN ANYTHING BUT CONSISTENT THE LAST FEW DAYS WRT PRECIP ERLY NEXT WEEK, SO WHILE MON STILL LOOKS TO BE POTENTIALLY THE BEST SHOT, STILL NOT HANGING MY HAT ON IT JUST YET UNTIL SEE BETTER RUN-TO-RUN CONSISTENCY. THE H5 TROF SHARPENS THRU THE COURSE OF THE WEEK AND AS IT MOVES SWD SEEMS TO MOVE THE HIGH SWD AS WELL. THIS, IN TURN WANTS TO SHUNT ANY PRECIP FURTHER AWAY FROM THE REGION. WHILE IT IS STILL VERY CLOSE ON SOME DAYS, THE DIFFERENCE BETWEEN A NO POP AND VERY LOW POP IS NOT MUCH AT THIS TIME SCALE SO HAVE KEPT MUCH OF THE EXTENDD DRY. HOWEVER, IT MUST BE NOTED THAT CONFIDENCE REMAINS LOWER THAN AVERAGE ATTM. TEMPS WILL START OFF ABV NRML, BUT THEN END UP AT OR SLIGHTLY BELOW NRML. && .AVIATION /13Z THURSDAY THROUGH MONDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR TODAY AND THIS EVENING. A LIGHT SOUTHERLY WINDS UNDER 10 KT WILL DEVELOP TODAY. WITH THE SAME AIRMASS IN PLACE, EXPECT RADIATIONAL FOG TO REDEVELOP AT THE MORE RURAL AIRPORTS LATE TONIGHT. OUTLOOK... SAT...VFR CONDS EXPECTED AFTER PSBL LOWER CEILINGS/VSBYS IN PATCHY FOG IN THE MRNG. MDT TO HIGH CONFIDENCE SAT NIGHT AND SUN...VFR. LOW CHC SHRA AND MVFR, MAINLY NW OF I-95. MDT TO HIGH CONFIDENCE. MON...VFR. LOW CHC SHRA AND MVFR. LOW CONFIDENCE. && .MARINE... NO HAZARDS EXPECTED ON THE WATERS TODAY AND TONIGHT. A LIGHT WLY WIND AROUND 5 KT THIS MORNING WILL BECOME SLY AND INCREASE TO AROUND 10 KT THIS AFTN AS A SEA-BREEZE FRONT MOVES INLAND. OUTLOOK... SAT THRU MON...CONDS WILL START OFF QUIET ON SAT INTO ERLY SUN. HOWEVER, A CDFNT WILL MOVE ACRS THE REGION FROM LATE SAT INTO SUN, REACHING THE CSTL WATERS ON SUN. BEHIND THE CDFNT, HIGH PRES WILL BUILD TO THE NE ALLOWING FOR A MORE NELY FLOW TO DEVELOP LATER SUN INTO MON. THIS WILL CAUSE WIND TO INCREASE AND SEAS TO BUILD. PSBLY BY LATE SUN NIGHT, IF NOT ON MON, WILL LIKELY NEED A SCA. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...NIERENBERG NEAR TERM...GIGI/KLEIN SHORT TERM...KLEIN LONG TERM...NIERENBERG AVIATION...KLEIN/NIERENBERG MARINE...KLEIN/NIERENBERG
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
803 PM EDT FRI SEP 18 2015 .UPDATE (OVERNIGHT AND SATURDAY)... 00Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS WEAK MID/UPPER LEVEL TROUGHING CONTINUES OVER THE FL PENINSULA AND EASTERN GULF OF MEXICO...HOWEVER THE DEEPEST OF MOISTURE HAS BEEN SHOVED EASTWARD DURING THE PAST 24 HOURS AND NOT LIES MAINLY OVER SOUTH FLORIDA AND THE ATLANTIC WATERS. AT THE SURFACE...AN ELONGATED AREA OF LOW WEAK LOW PRESSURE/TROUGHING EXTENDS FROM THE SOUTHEAST GULF OVER THE STATE OF FLORIDA TO NEAR THE COASTS OF GA/CAROLINAS. GUIDANCE IS IN GOOD AGREEMENT THE THIS LOW WILL CONSOLIDATE LATE TONIGHT/SATURDAY AND THEN PULL NORTHEASTWARD AWAY FROM THE FORECAST AREA. A FEW LINGERING SHOWERS STILL SEEN ON REGIONAL RADARS FROM SOUTHERN POLK TO SARASOTA COUNTY...BUT EXPECT THIS ACTIVITY TO FADE RAPIDLY WITH THE SETTING OF THE SUN AND LOSS OF DIURNAL HEATING. REMAINDER OF THE OVERNIGHT SHOULD SEE MOSTLY DRY AND SEASONABLE CONDITIONS AFTER THE LAST OF THE DIURNAL SHOWERS FADE. BETTER CHANCES FOR SHOWERS AFTER 03Z WILL EXIST OVER THE COASTAL WATERS OFF THE NATURE COAST...BUT NO SIGNIFICANT THUNDERSTORM ACTIVITY IS ANTICIPATED. THE FORECAST FOR SATURDAY LOOKS TO REMAIN SEASONABLE. DRY CONDITIONS IN THE MORNING WILL GIVE WAY TO WIDELY SCATTERED AFTERNOON SHOWERS AS THE SEA-BREEZE DEVELOPS AND PUSHES SLOWLY INLAND. RAIN CHANCES MAXIMIZE INLAND AFTER 18-20Z IN THE 30-40% RANGE. && .AVIATION... GENERAL VFR CONDITIONS PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA THIS EVENING. LINGERING DIURNAL SHOWERS LOCATED BETWEEN KSRQ AND KPGD ARE BEGINNING TO FADE WITH THE LOSS OF DIURNAL HEATING AND IS IS UNLIKELY ANY OF THE TERMINALS WILL EXPERIENCE A SHOWER THE REST OF THE NIGHT. A BRIEF PERIOD OF MVFR CIGS WILL BE POSSIBLE LATE TONIGHT/EARLY SATURDAY MORNING...WITH KTPA/KLAL/KPGD SEEING THE BEST CHANCE AT A BRIEF CIG RESTRICTION BETWEEN 09Z AND 13Z. && .MARINE... LOW PRESSURE WILL PULL SLOWLY AWAY FROM THE FLORIDA PENINSULA ALONG THE CAROLINA COAST LATER TONIGHT AND SATURDAY. THE GRADIENT OVER THE EASTERN GULF WILL RELAX DURING SATURDAY AS THIS OCCURS. NORTHEAST WINDS MAY BRIEFLY APPROACH CAUTIONARY LEVELS TO THE NORTH OF TAMPA BAY TONIGHT...BUT WILL QUICKLY SETTLE BELOW 15 KNOTS SATURDAY MORNING. GENERALLY LIGHT WINDS FROM THE NORTH OR NORTHEAST WILL THEN PERSIST THROUGH THE REMAINDER OF THE WEEKEND. && .PRELIMINARY POINT TEMPS/POPS... TPA 74 88 77 91 / 10 30 10 10 FMY 74 89 76 91 / 20 30 10 30 GIF 73 90 74 92 / 20 30 20 20 SRQ 75 90 76 90 / 20 20 10 10 BKV 72 89 70 92 / 20 20 10 10 SPG 75 88 77 90 / 10 20 10 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...NONE. GULF WATERS...NONE. && $$ UPDATE/AVIATION/MARINE...14/MROCZKA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1235 PM EDT THU SEP 17 2015 .SYNOPSIS... DRY HIGH PRESSURE WILL REMAIN ANCHORED ALONG THE EASTERN SEABOARD... WHILE LOW PRESSURE MEANDERS OFFSHORE...ENSURING GENERALLY FAIR WEATHER FOR OUR FORECAST AREA THROUGH THE WEEKEND. A FRONT ALONG WITH AN UPPER LOW IS EXPECTED TO LEAD TO INCREASED PRECIPITATION CHANCES EARLY TO MID NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE FORECAST AREA. THE HRRR DISPLAYS JUST ISOLATED SHOWERS IN THE EAST PART THIS AFTERNOON. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN STRATUS LATE TONIGHT. THE GFS AND NAM MOS INDICATE LOW CLOUDINESS DEVELOPING. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .SHORT TERM /FRIDAY THROUGH SATURDAY NT/... WEAK UPPER TROUGH NEAR OUR REGION WILL MOVE VERY SLOWLY TO THE EAST...WITH LOW PRESSURE DEVELOPING OFFSHORE AND MOVING VERY SLOWLY OFFSHORE. BEST ATMOSPHERIC MOISTURE WILL REMAIN EAST OF OUR FORECAST AREA (FA)...THOUGH A GENERALLY ONSHORE LOW LEVEL FLOW MAY RESULT IN INCREASING MOISTURE PENETRATING SLIGHTLY INLAND TO PERHAPS GIVE OUR SE FA A SLIGHT CHANCE OF A SHOWER. GUIDANCE INDICATING A CONTINUED SLIGHT WARMING TREND...WITH TEMPS REACHING BACK UP TO NEAR OR JUST ABOVE CLIMO. && .LONG TERM /SUNDAY THROUGH THURSDAY/... LITTLE CHANGE SUNDAY. WEAK HIGH PRESSURE TO REMAIN OVER THE MID ATLANTIC AND CAROLINAS WHILE UPPER AND SURFACE LOW REMAIN OFFSHORE. AN UPPER DISTURBANCE AND FRONT WILL MOVE ACROSS THE GREAT LAKES/MIDWEST REGION...WITH SURFACE HIGH PRESSURE BEHIND IT BUILDING INTO NEW ENGLAND SUN/MON. MODELS INDICATE NEXT UPPER TROUGH MOVING ACROSS THE NORTHERN TIER OF STATES...CUTTING OFF JUST TO OUR WEST BY TUE/WED. MEANWHILE OLD UPPER TROUGH AND SURFACE LOW CONTINUE TO MEANDER OFFSHORE. ALL THIS APPEARS TO LEAD TO POSSIBLE BACK DOOR FRONT MOVING SOUTH INTO OUR REGION EARLY TO MID WEEK...WITH INCREASING MOISTURE AND PRECIPITATION CHANCES...AND POSSIBLE WEAK WEDGE DEVELOPMENT. ACCEPTED BLEND OF GUIDANCE...INDICATING INCREASED POPS AND LOWER MAX TEMPS. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE TERMINALS. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN RESTRICTIONS DURING THE EARLY MORNING HOURS FRIDAY. THE NAM AND GFS MOS INDICATE MVFR OR IFR CONDITIONS DEVELOPING. EXTENDED AVIATION OUTLOOK...MVFR RESTRICTIONS IN FOG AND STRATUS POSSIBLE EACH MORNING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1058 AM EDT THU SEP 17 2015 .SYNOPSIS... MOISTURE WILL OCCUR IN AN ONSHORE FLOW BUT THE DEEPER MOISTURE WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. EXPECT WIDELY SCATTERED SHOWERS IN THE CSRA AND SOUTHEAST MIDLANDS THROUGH FRIDAY. IT WILL BE FAIR AND WARMER OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE FORECAST AREA. THE HRRR DISPLAYS JUST ISOLATED SHOWERS IN THE EAST PART THIS AFTERNOON. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN STRATUS LATE TONIGHT. THE GFS AND NAM MOS INDICATE LOW CLOUDINESS DEVELOPING. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... LITTLE CHANGE IN THE PATTERN TONIGHT INTO FRIDAY. LIMITED MOISTURE IN THE MIDLANDS BUT WEAK ONSHORE FLOW CONTINUES WITH WEAK LOW PRESSURE OFF THE COAST. WIDELY SCATTERED MAINLY AFTERNOON SHOWERS IN THE EAST MIDLANDS. WITH AIR MASS MODIFICATION...WARMING SLIGHTLY INTO FRIDAY. TEMPERATURES WILL BE CLOSE TO NORMAL. SURFACE AND UPPER TROUGH MOVES EAST BY SATURDAY WITH WEAK UPPER RIDGE BUILDING EAST FROM THE SOUTHERN PLAINS/GULF COAST. EXPECT WARMING TREND AND LIMITED LOW LEVEL MOISTURE ACROSS AREA. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... INCREASED POPS SLIGHTLY FROM PREVIOUS FORECAST BASED ON LATEST 00Z GFS AND WPC GUIDANCE... HIGH PRESSURE WILL REMAIN THE DOMINATE FEATURE THROUGH THE WEEKEND. A WEAK COLD FRONT AND ASSOCIATED SHORT WAVE WILL APPROACH THE AREA MONDAY INCREASING THE THREAT OF CONVECTION LATE MONDAY INTO TUESDAY. ONCE AGAIN...LOOKS LIKE THE MID/UPPER LEVEL SYSTEM WILL CLOSE OFF ACROSS THE EAST BY MID WEEK. THIS WILL KEEP A CHANCE OF SHOWERS IN THE FORECAST THROUGH THE MIDDLE OF NEXT WEEK. TEMPS WILL MODERATE HEADING INTO THE WEEKEND WITH HIGHS IN THE UPPER 80S TO POSSIBLY LOWER 90S IN A FEW AREAS OVER THE WEEKEND BEFORE COOLING DOWN SLIGHTLY NEXT WEEK. EXPECT OVERNIGHT LOWS TO BE SEASONAL IN THE LOWER/MIDDLE 60S. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE TERMINALS. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN RESTRICTIONS DURING THE EARLY MORNING HOURS FRIDAY. THE NAM AND GFS MOS INDICATE MVFR OR IFR CONDITIONS DEVELOPING. EXTENDED AVIATION OUTLOOK...MVFR RESTRICTIONS IN FOG AND STRATUS POSSIBLE EACH MORNING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
828 AM EDT THU SEP 17 2015 .SYNOPSIS... MOISTURE WILL OCCUR IN AN ONSHORE FLOW BUT THE DEEPER MOISTURE WILL REMAIN SOUTH AND EAST OF THE FORECAST AREA. EXPECT WIDELY SCATTERED SHOWERS IN THE CSRA AND SOUTHEAST MIDLANDS THROUGH FRIDAY. IT WILL BE FAIR AND WARMER OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE FORECAST AREA. THE HRRR DISPLAYS JUST ISOLATED SHOWERS IN THE EAST PART THIS AFTERNOON. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN STRATUS LATE TONIGHT. THE GFS AND NAM MOS INDICATE LOW CLOUDINESS DEVELOPING. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... LITTLE CHANGE IN THE PATTERN TONIGHT INTO FRIDAY. LIMITED MOISTURE IN THE MIDLANDS BUT WEAK ONSHORE FLOW CONTINUES WITH WEAK LOW PRESSURE OFF THE COAST. WIDELY SCATTERED MAINLY AFTERNOON SHOWERS IN THE EAST MIDLANDS. WITH AIR MASS MODIFICATION...WARMING SLIGHTLY INTO FRIDAY. TEMPERATURES WILL BE CLOSE TO NORMAL. SURFACE AND UPPER TROUGH MOVES EAST BY SATURDAY WITH WEAK UPPER RIDGE BUILDING EAST FROM THE SOUTHERN PLAINS/GULF COAST. EXPECT WARMING TREND AND LIMITED LOW LEVEL MOISTURE ACROSS AREA. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... INCREASED POPS SLIGHTLY FROM PREVIOUS FORECAST BASED ON LATEST 00Z GFS AND WPC GUIDANCE... HIGH PRESSURE WILL REMAIN THE DOMINATE FEATURE THROUGH THE WEEKEND. A WEAK COLD FRONT AND ASSOCIATED SHORT WAVE WILL APPROACH THE AREA MONDAY INCREASING THE THREAT OF CONVECTION LATE MONDAY INTO TUESDAY. ONCE AGAIN...LOOKS LIKE THE MID/UPPER LEVEL SYSTEM WILL CLOSE OFF ACROSS THE EAST BY MID WEEK. THIS WILL KEEP A CHANCE OF SHOWERS IN THE FORECAST THROUGH THE MIDDLE OF NEXT WEEK. TEMPS WILL MODERATE HEADING INTO THE WEEKEND WITH HIGHS IN THE UPPER 80S TO POSSIBLY LOWER 90S IN A FEW AREAS OVER THE WEEKEND BEFORE COOLING DOWN SLIGHTLY NEXT WEEK. EXPECT OVERNIGHT LOWS TO BE SEASONAL IN THE LOWER/MIDDLE 60S. && .AVIATION /13Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. HIGH PRESSURE WILL BE NEAR THE MID-ATLANTIC COAST WITH AN INVERTED TROUGH OFF THE SOUTHEAST COAST. MOISTURE ASSOCIATED WITH AN ONSHORE FLOW AND THE TROUGH WILL STAY MAINLY EAST OF THE TERMINALS. LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY RESULT IN RESTRICTIONS DURING THE EARLY MORNING HOURS FRIDAY. THE NAM AND GFS MOS INDICATE MVFR OR IFR CONDITIONS DEVELOPING. EXTENDED AVIATION OUTLOOK...MVFR RESTRICTIONS IN FOG AND STRATUS POSSIBLE EACH MORNING. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$ 99
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1035 PM CDT FRI SEP 18 2015 .SHORT TERM... 211 PM CDT THROUGH TONIGHT... IN ADDITION TO SOME LIGHT RAIN/DRIZZLE FARTHER NORTH...WE ARE BEGINNING TO SEE SCATTERED SHOWER DEVELOPMENT FARTHER NORTH INTO OUR AREA THIS AFTERNOON AS THE AREA BEGINS TO FEEL MORE OF THE LIFT FROM A PAIR OF LEADING SHORTWAVES AHEAD OF A VERY WELL DEFINED UPPER LEVEL TROUGH AND CLOSED CIRCULATION MOVING EAST THROUGH THE DAKOTAS. THE FIRST OF THESE WAVES IS PUSHING INTO WEST CENTRAL ILLINOIS WHERE MORE ORGANIZED THUNDERSTORM ACTIVITY IS FOCUSED. THESE ARE IN AREAS WHERE EARLIER BREAKS IN LOWER LEVEL STRATUS HAVE ENABLED GREATER DESTABILIZATION. A STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE WESTERN CWA. ADDITIONAL ELEVATED THUNDERSTORMS THROUGH SOUTHERN IOWA AND EXTENDING TO NEAR THE MISSISSIPPI RIVER IN FAR EASTERN IOWA AHEAD OF THESE ADDITIONAL LEADING SHORTWAVES. EXPECT SHOWERS AND ISOLATED THUNDERSTORMS TO INCREASE IN COVERAGE INTO NORTHEAST ILLINOIS AND NORTHWEST INDIANA. AS THE AFTERNOON CONTINUES. WITH THE THICK CLOUD COVER FARTHER NORTH...FEEL THE MORE ACTIVE STORMS WILL BE CONFINED ALONG AND SOUTH OF INTERSTATE 80 WHERE LOCALLY HEAVY RAINFALL IS EXPECTED AND STORM MOTION IS NOT SUPER FAST. A SEVERE THREAT EXISTS AS WELL DUE TO MODEST MID LEVEL LAPSE RATES (NEAR 7 DEG/KM ON THE KDVN MORNING SOUNDING)...THOUGH SHEAR HAS DECREASED SOMEWHAT LOWER THAN WHAT WAS DEPICTED EARLIER TODAY ON THE RAP SPC MESOANALYSIS. IT IS FORECAST TO INCREASE AGAIN AS THE AFTERNOON CONTINUES...KEEPING SOME THREAT FOR GUSTY WINDS AND HAIL MAINLY FOR OUR WESTERN AND SOUTHERN AREAS. WIDESPREAD SEVERE WEATHER WITH THIS WAVE IS NOT ANTICIPATED AS SHOWERS/STORMS TO THE NORTH WILL BE ELEVATED. IT LOOKS LIKE AFTER THIS ACTIVITY MOVES THROUGH...THERE COULD BE A SHORT BREAK BEFORE THE MORE ORGANIZED ACTIVITY ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH LATER THIS EVENING AND TONIGHT. THIS BREAK...IF IT OCCURS...WOULD LAST THE LONGEST FOR POINTS SOUTH AND EAST ABD THERE MAY NOT BE MUCH OF A BREAK IN AREAS NORTH AND WEST. THE TIMING ON THIS ROUND OF MORE ORGANIZED THUNDERSTORM ACTIVITY IS AFTER 7-8 PM IN THE WEST...AND AFTER 9 PM CLOSER TO CHICAGO. CURRENT SHORT TERM RUNS OF THE HRRR/RAP SUGGEST IT COULD BE SLIGHTLY LATER THAN THAT FOR AREAS SOUTH AND EAST OF I-57. THE BEST COMBINATION OF UPPER Q-G FORCING FROM THE UPPER TROUGH AND LOWER FRONTOGENETICAL FORCING ON THE BACK SIDE OF THE SURFACE LOW IS ALONG AND NORTH OF I- 80 FOR THIS SECOND ROUND OF STORMS...WHICH IS MAXIMIZED IN THE LATE EVENING AND EARLY MORNING HOURS WHEN THE PERIOD OF HIGHEST CONCERN FOR HEAVY RAIN EXISTS. MANY AREAS WILL SEE HEAVY RAIN ACTIVITY WITH THIS WAVE...BUT HAVE HELD ONTO THE FLASH FLOOD WATCH FOR THE CURRENT AREAS THAT RECEIVED THE HEAVIEST RAINS LAST NIGHT. LEAST FAVORED AREAS ARE SOUTH AND EAST OF INTERSTATE 57 AND HAVE PLACED HIGHEST QPF IN THE MOST FAVORED FORCING LOCATIONS IN NORTH AND NORTH CENTRAL ILLINOIS. MOST UNSTABLE CAPE IN EXCESS OF 1000 J/KG AND EFFECTIVE SHEAR OF 40+ KT SUGGEST THE POTENTIAL FOR SEVERE HAIL AND LOCALLY STRONG WINDS AGAIN WITH THE LATER EVENING STORMS...WITH THE WIND THREAT CONTINGENT ON STORMS EVOLVING INTO A LINE. THE SURFACE LOW CONTINUES DEEPENING OVERNIGHT AS IT MOVES NORTHEASTWARD. THE COLD FRONT SPREADS IN FROM NORTHWEST TO SOUTHEAST WHICH SHOULD EASE SHOWER/STORM THREAT OVERNIGHT. BRISK NORTHWEST WINDS WILL USHER IN A MUCH COOLER AND DRIER AIRMASS. KMD && .LONG TERM... 236 PM CDT SATURDAY THROUGH FRIDAY... MID-LEVEL SHORT WAVE TROUGH AND SURFACE FRONTAL SYSTEM ASSOCIATED WITH SHORT TERM RAIN/THUNDERSTORMS WILL BE MOVING OUT OF THE FORECAST AREA EARLY SATURDAY MORNING. LINGERING LOW LEVEL MOISTURE BEHIND THE FRONT AND FORCING ASSOCIATED WITH THE PASSAGE OF THE MID-LEVEL TROUGH MAY ALLOW A FEW SHOWERS/SPRINKLES TO PERSIST MAINLY ACROSS THE FAR SOUTHEAST PARTS OF THE CWA PAST SUNRISE...THOUGH BREEZY NORTH WINDS QUICKLY ADVECT DRIER AIR INTO THE REGION PER FORECAST SOUNDINGS ALLOWING A QUICK END TO ANY PRECIP AND DECREASING CLOUD COVER THROUGH THE LATE MORNING HOURS. WHILE SUNSHINE RETURNS...COOLER TEMPS IN THE UPPER 60S/AROUND 70 AND BREEZY NORTH WINDS GUSTING AROUND 20 MPH ESPECIALLY IN THE MORNING WILL MAKE FOR AN AUTUMN FEEL. SURFACE HIGH PRESSURE BUILDS ACROSS THE AREA SATURDAY NIGHT...WITH CLEAR SKIES...LIGHT/CALM WINDS AND COOL/DRY AIR MASS...WILL LIKELY PRODUCE SOME CHILLY LOW- MID 40S IN COOLER SPOTS AND HAVE UNDERCUT GUIDANCE/BLENDED TOWARD COOLER MAV MINS. BREEZY NORTH WINDS GUSTING 20-25 MPH SATURDAY MORNING/EARLY AFTERNOON WILL QUICKLY DIMINISH DURING THE AFTERNOON. REST OF EXTENDED PERIOD LOOKS TO REMAIN VERY QUIET...WITH A GRADUAL MODERATING TREND THROUGH MID/LATE WEEK AS UPPER RIDGE DEVELOPS OVER THE SOUTHWESTERN CONUS...AND EVENTUALLY BUILDS NORTHEASTWARD INTO THE GREAT LAKES REGION BY MID-WEEK. SURFACE HIGH SLIDES EAST OF THE AREA BY LATER SUNDAY...THOUGH WESTERN PERIPHERY OF SFC RIDGE AXIS LINGERS ACROSS THE REGION FOR A FEW DAYS. THIS SETS UP A FAIRLY PLEASANT PERIOD OF MILD DAYS WITH TEMPS SLOWLY WARMING FROM THE LOW 70S (UPPER 60S NEAR THE LAKE) TO 75-80/LOW 80S RANGE BY THE LATTER HALF OF THE WEEK...WITH LOWS IN THE 40S/50S MODERATING BACK INTO THE 50S/NEAR 60. NO REAL THREAT OF ORGANIZED RAIN APPEARS AT THIS TIME BEYOND SATURDAY MORNING...UNTIL PERHAPS LATE THURSDAY OR FRIDAY AS A WEAK COLD FRONT SETTLES ACROSS THE UPPER MISSISSIPPI/WESTERN LAKES REGION. SOME MODEL SOLUTIONS KEEP THIS FRONT NORTH OF THE AREA HOWEVER...OR DONT DEVELOP SIGNIFICANT PRECIP ALONG IT...WITH THE UPPER RIDGE RE-BUILDING INTO NEXT WEEKEND. THUS HAVE HELD FORECAST DRY THROUGH FRI AND GIVEN JUST A NOD TO SLIGHTLY COOLER TEMPS ACROSS THE NORTHERN PART OF THE FORECAST AREA BY FRIDAY PER BLENDED GUIDANCE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 03Z... * ONE MORE PERIOD OF RA/TSRA WITH OCNL IFR CONDITIONS * RA/TSRA ENDS OVERNIGHT WITH WIND SHIFT TO NW OR NNW LATE TONIGHT * MODERATELY STRONG/GUSTY NNW WINDS SATURDAY MORNING * WIND SHIFT TO NE PROBABLE LATE SATURDAY AFTERNOON/EARLY SAT EVENING IZZI //DISCUSSION...UPDATED 00Z... UPPER LEVEL DISTURBANCE AND APPROACH COLD FRONT WILL CONTINUE TO SUPPORT FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS THIS EVENING WITH OCNL HEAVY RAIN AND IFR CONDITIONS EXPECTED. SHRA/TSRA SHOULD TAPER OFF AND END OVERNIGHT WITH PASSAGE OF COLD FRONT. GUSTY NORTHWEST TO NORTH-NORTHWEST WINDS WILL DEVELOP BEHIND THE FRONT WITH A COUPLE KNOTS OF 25-30KT GUSTS EXPECTED SAT MORNING BEFORE WINDS SLOWLY EASE SATURDAY AFTERNOON. AS WINDS BEGIN TO EASE DURING THE AFTERNOON EXPECT LAKE BREEZE TO FORM AND PUSH GRADUALLY WESTWARD AND LIKELY MOVING ACROSS ORD/MDW DURING THE LATE AFTERNOON OR EARLY EVENING BEFORE WINDS SUBSIDE WITH SUNSET. COULD SEE FEW HOURS OF MVFR CIGS IMMEDIATELY BEHIND THE FRONT LATE TONIGHT BUT SHOULD SEE TREND TO VFR CONDITIONS SATURDAY MORNING. IZZI //ORD AND MDW CONFIDENCE...UPDATED 03Z... * HIGH CONFIDENCE REMAINING FORECAST ELEMENTS IZZI //OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z... SUNDAY THROUGH THURSDAY...VFR. IZZI && .MARINE... 257 PM CDT MAIN MARINE CONCERNS ARE IN THE FIRST 24-36 HOURS OF THE FORECAST THIS AFTERNOON...WITH A PERIOD OF NORTH GALES LIKELY ON CENTRAL AND SOUTHERN LAKE MICHIGAN SATURDAY MORNING. A NEARLY STATIONARY COLD FRONT STRETCHED FROM LOW PRESSURE OVER EASTERN CANADA...SOUTHWEST ACROSS LAKE MICHIGAN TO THE SOUTHERN PLAINS. A SURFACE LOW PRESSURE WAVE WILL LIFT NORTHEAST ALONG THE FRONT THIS EVENING...EVENTUALLY DEEPENING AS IT LIFTS NORTHEAST OF THE LAKE EARLY SATURDAY AND PULLING THE COLD FRONT SOUTHEAST AND CLEAR OF THE LAKE. AS THE LOW DEEPENS OFF TO THE NORTHEAST EARLY SATURDAY...AND HIGH PRESSURE BEGINS TO BUILD EASTWARD ACROSS THE PLAINS...THE COMBINATION OF A TIGHTENING SURFACE PRESSURE GRADIENT AND LOW LEVEL COLD AIR ADVECTION IS EXPECTED TO LEAD TO A BRIEF PERIOD OF 30-35 KT WINDS OVER THE LAKE. GALE FORCE WINDS APPEAR TO BE MOST LIKELY ACROSS CENTRAL AND SOUTHERN LAKE MICHIGAN FROM THE PREDAWN HOURS THROUGH MID-LATE MORNING SATURDAY. WINDS WILL THEN QUICKLY DIMINISH LATER SATURDAY AFTERNOON AND NIGHT AS THE SURFACE HIGH MOVES INTO THE REGION. BEYOND SATURDAY...THE WEATHER PATTERN LOOKS TO REMAIN FAIRLY QUIET WITH THE TRAILING WESTERN PERIPHERY OF THE SURFACE RIDGE AXIS REMAINING OVER THE CENTRAL OR SOUTHERN PART OF THE LAKE...WHILE AN AREA OF LOW PRESSURE PASSES WELL NORTH OF THE LAKES THROUGH MID- WEEK. THIS WILL LIKELY RESULT IN MODEST SOUTH- SOUTHWEST WINDS INCREASING A BIT ON THE NORTH END OF THE LAKE AND PERHAPS GUSTING 15-20 KTS AT TIMES...WHILE REMAINING LIGHTER FARTHER SOUTH. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022 UNTIL 7 AM SATURDAY. BEACH HAZARDS STATEMENT...ILZ006-ILZ014...4 AM SATURDAY TO 10 PM SATURDAY. IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...4 AM SATURDAY TO 10 PM SATURDAY. LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...4 AM SATURDAY TO 1 PM SATURDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
706 PM CDT FRI SEP 18 2015 .SHORT TERM... 211 PM CDT THROUGH TONIGHT... IN ADDITION TO SOME LIGHT RAIN/DRIZZLE FARTHER NORTH...WE ARE BEGINNING TO SEE SCATTERED SHOWER DEVELOPMENT FARTHER NORTH INTO OUR AREA THIS AFTERNOON AS THE AREA BEGINS TO FEEL MORE OF THE LIFT FROM A PAIR OF LEADING SHORTWAVES AHEAD OF A VERY WELL DEFINED UPPER LEVEL TROUGH AND CLOSED CIRCULATION MOVING EAST THROUGH THE DAKOTAS. THE FIRST OF THESE WAVES IS PUSHING INTO WEST CENTRAL ILLINOIS WHERE MORE ORGANIZED THUNDERSTORM ACTIVITY IS FOCUSED. THESE ARE IN AREAS WHERE EARLIER BREAKS IN LOWER LEVEL STRATUS HAVE ENABLED GREATER DESTABILIZATION. A STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE WESTERN CWA. ADDITIONAL ELEVATED THUNDERSTORMS THROUGH SOUTHERN IOWA AND EXTENDING TO NEAR THE MISSISSIPPI RIVER IN FAR EASTERN IOWA AHEAD OF THESE ADDITIONAL LEADING SHORTWAVES. EXPECT SHOWERS AND ISOLATED THUNDERSTORMS TO INCREASE IN COVERAGE INTO NORTHEAST ILLINOIS AND NORTHWEST INDIANA. AS THE AFTERNOON CONTINUES. WITH THE THICK CLOUD COVER FARTHER NORTH...FEEL THE MORE ACTIVE STORMS WILL BE CONFINED ALONG AND SOUTH OF INTERSTATE 80 WHERE LOCALLY HEAVY RAINFALL IS EXPECTED AND STORM MOTION IS NOT SUPER FAST. A SEVERE THREAT EXISTS AS WELL DUE TO MODEST MID LEVEL LAPSE RATES (NEAR 7 DEG/KM ON THE KDVN MORNING SOUNDING)...THOUGH SHEAR HAS DECREASED SOMEWHAT LOWER THAN WHAT WAS DEPICTED EARLIER TODAY ON THE RAP SPC MESOANALYSIS. IT IS FORECAST TO INCREASE AGAIN AS THE AFTERNOON CONTINUES...KEEPING SOME THREAT FOR GUSTY WINDS AND HAIL MAINLY FOR OUR WESTERN AND SOUTHERN AREAS. WIDESPREAD SEVERE WEATHER WITH THIS WAVE IS NOT ANTICIPATED AS SHOWERS/STORMS TO THE NORTH WILL BE ELEVATED. IT LOOKS LIKE AFTER THIS ACTIVITY MOVES THROUGH...THERE COULD BE A SHORT BREAK BEFORE THE MORE ORGANIZED ACTIVITY ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH LATER THIS EVENING AND TONIGHT. THIS BREAK...IF IT OCCURS...WOULD LAST THE LONGEST FOR POINTS SOUTH AND EAST ABD THERE MAY NOT BE MUCH OF A BREAK IN AREAS NORTH AND WEST. THE TIMING ON THIS ROUND OF MORE ORGANIZED THUNDERSTORM ACTIVITY IS AFTER 7-8 PM IN THE WEST...AND AFTER 9 PM CLOSER TO CHICAGO. CURRENT SHORT TERM RUNS OF THE HRRR/RAP SUGGEST IT COULD BE SLIGHTLY LATER THAN THAT FOR AREAS SOUTH AND EAST OF I-57. THE BEST COMBINATION OF UPPER Q-G FORCING FROM THE UPPER TROUGH AND LOWER FRONTOGENETICAL FORCING ON THE BACK SIDE OF THE SURFACE LOW IS ALONG AND NORTH OF I- 80 FOR THIS SECOND ROUND OF STORMS...WHICH IS MAXIMIZED IN THE LATE EVENING AND EARLY MORNING HOURS WHEN THE PERIOD OF HIGHEST CONCERN FOR HEAVY RAIN EXISTS. MANY AREAS WILL SEE HEAVY RAIN ACTIVITY WITH THIS WAVE...BUT HAVE HELD ONTO THE FLASH FLOOD WATCH FOR THE CURRENT AREAS THAT RECEIVED THE HEAVIEST RAINS LAST NIGHT. LEAST FAVORED AREAS ARE SOUTH AND EAST OF INTERSTATE 57 AND HAVE PLACED HIGHEST QPF IN THE MOST FAVORED FORCING LOCATIONS IN NORTH AND NORTH CENTRAL ILLINOIS. MOST UNSTABLE CAPE IN EXCESS OF 1000 J/KG AND EFFECTIVE SHEAR OF 40+ KT SUGGEST THE POTENTIAL FOR SEVERE HAIL AND LOCALLY STRONG WINDS AGAIN WITH THE LATER EVENING STORMS...WITH THE WIND THREAT CONTINGENT ON STORMS EVOLVING INTO A LINE. THE SURFACE LOW CONTINUES DEEPENING OVERNIGHT AS IT MOVES NORTHEASTWARD. THE COLD FRONT SPREADS IN FROM NORTHWEST TO SOUTHEAST WHICH SHOULD EASE SHOWER/STORM THREAT OVERNIGHT. BRISK NORTHWEST WINDS WILL USHER IN A MUCH COOLER AND DRIER AIRMASS. KMD && .LONG TERM... 236 PM CDT SATURDAY THROUGH FRIDAY... MID-LEVEL SHORT WAVE TROUGH AND SURFACE FRONTAL SYSTEM ASSOCIATED WITH SHORT TERM RAIN/THUNDERSTORMS WILL BE MOVING OUT OF THE FORECAST AREA EARLY SATURDAY MORNING. LINGERING LOW LEVEL MOISTURE BEHIND THE FRONT AND FORCING ASSOCIATED WITH THE PASSAGE OF THE MID-LEVEL TROUGH MAY ALLOW A FEW SHOWERS/SPRINKLES TO PERSIST MAINLY ACROSS THE FAR SOUTHEAST PARTS OF THE CWA PAST SUNRISE...THOUGH BREEZY NORTH WINDS QUICKLY ADVECT DRIER AIR INTO THE REGION PER FORECAST SOUNDINGS ALLOWING A QUICK END TO ANY PRECIP AND DECREASING CLOUD COVER THROUGH THE LATE MORNING HOURS. WHILE SUNSHINE RETURNS...COOLER TEMPS IN THE UPPER 60S/AROUND 70 AND BREEZY NORTH WINDS GUSTING AROUND 20 MPH ESPECIALLY IN THE MORNING WILL MAKE FOR AN AUTUMN FEEL. SURFACE HIGH PRESSURE BUILDS ACROSS THE AREA SATURDAY NIGHT...WITH CLEAR SKIES...LIGHT/CALM WINDS AND COOL/DRY AIR MASS...WILL LIKELY PRODUCE SOME CHILLY LOW- MID 40S IN COOLER SPOTS AND HAVE UNDERCUT GUIDANCE/BLENDED TOWARD COOLER MAV MINS. BREEZY NORTH WINDS GUSTING 20-25 MPH SATURDAY MORNING/EARLY AFTERNOON WILL QUICKLY DIMINISH DURING THE AFTERNOON. REST OF EXTENDED PERIOD LOOKS TO REMAIN VERY QUIET...WITH A GRADUAL MODERATING TREND THROUGH MID/LATE WEEK AS UPPER RIDGE DEVELOPS OVER THE SOUTHWESTERN CONUS...AND EVENTUALLY BUILDS NORTHEASTWARD INTO THE GREAT LAKES REGION BY MID-WEEK. SURFACE HIGH SLIDES EAST OF THE AREA BY LATER SUNDAY...THOUGH WESTERN PERIPHERY OF SFC RIDGE AXIS LINGERS ACROSS THE REGION FOR A FEW DAYS. THIS SETS UP A FAIRLY PLEASANT PERIOD OF MILD DAYS WITH TEMPS SLOWLY WARMING FROM THE LOW 70S (UPPER 60S NEAR THE LAKE) TO 75-80/LOW 80S RANGE BY THE LATTER HALF OF THE WEEK...WITH LOWS IN THE 40S/50S MODERATING BACK INTO THE 50S/NEAR 60. NO REAL THREAT OF ORGANIZED RAIN APPEARS AT THIS TIME BEYOND SATURDAY MORNING...UNTIL PERHAPS LATE THURSDAY OR FRIDAY AS A WEAK COLD FRONT SETTLES ACROSS THE UPPER MISSISSIPPI/WESTERN LAKES REGION. SOME MODEL SOLUTIONS KEEP THIS FRONT NORTH OF THE AREA HOWEVER...OR DONT DEVELOP SIGNIFICANT PRECIP ALONG IT...WITH THE UPPER RIDGE RE-BUILDING INTO NEXT WEEKEND. THUS HAVE HELD FORECAST DRY THROUGH FRI AND GIVEN JUST A NOD TO SLIGHTLY COOLER TEMPS ACROSS THE NORTHERN PART OF THE FORECAST AREA BY FRIDAY PER BLENDED GUIDANCE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * RA/TSRA THIS EVENING WITH OCNL IFR CONDITIONS * RA/TSRA ENDS OVERNIGHT WITH WIND SHIFT TO NW OR NNW LATE TONIGHT * MODERATELY STRONG/GUSTY NNW WINDS SATURDAY MORNING * WIND SHIFT TO NE PROBABLE LATE SATURDAY AFTERNOON/EARLY SAT EVENING IZZI //DISCUSSION...UPDATED 00Z... UPPER LEVEL DISTURBANCE AND APPROACH COLD FRONT WILL CONTINUE TO SUPPORT FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS THIS EVENING WITH OCNL HEAVY RAIN AND IFR CONDITIONS EXPECTED. SHRA/TSRA SHOULD TAPER OFF AND END OVERNIGHT WITH PASSAGE OF COLD FRONT. GUSTY NORTHWEST TO NORTH-NORTHWEST WINDS WILL DEVELOP BEHIND THE FRONT WITH A COUPLE KNOTS OF 25-30KT GUSTS EXPECTED SAT MORNING BEFORE WINDS SLOWLY EASE SATURDAY AFTERNOON. AS WINDS BEGIN TO EASE DURING THE AFTERNOON EXPECT LAKE BREEZE TO FORM AND PUSH GRADUALLY WESTWARD AND LIKELY MOVING ACROSS ORD/MDW DURING THE LATE AFTERNOON OR EARLY EVENING BEFORE WINDS SUBSIDE WITH SUNSET. COULD SEE FEW HOURS OF MVFR CIGS IMMEDIATELY BEHIND THE FRONT LATE TONIGHT BUT SHOULD SEE TREND TO VFR CONDITIONS SATURDAY MORNING. IZZI //ORD AND MDW CONFIDENCE...UPDATED 00Z... * MEDIUM CONFIDENCE IN TIMING OF ENDING OF TSRA TONIGHT * MEDIUM-HIGH CONFIDENCE REMAINING FORECAST ELEMENTS IZZI //OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z... SUNDAY THROUGH THURSDAY...VFR. IZZI && .MARINE... 257 PM CDT MAIN MARINE CONCERNS ARE IN THE FIRST 24-36 HOURS OF THE FORECAST THIS AFTERNOON...WITH A PERIOD OF NORTH GALES LIKELY ON CENTRAL AND SOUTHERN LAKE MICHIGAN SATURDAY MORNING. A NEARLY STATIONARY COLD FRONT STRETCHED FROM LOW PRESSURE OVER EASTERN CANADA...SOUTHWEST ACROSS LAKE MICHIGAN TO THE SOUTHERN PLAINS. A SURFACE LOW PRESSURE WAVE WILL LIFT NORTHEAST ALONG THE FRONT THIS EVENING...EVENTUALLY DEEPENING AS IT LIFTS NORTHEAST OF THE LAKE EARLY SATURDAY AND PULLING THE COLD FRONT SOUTHEAST AND CLEAR OF THE LAKE. AS THE LOW DEEPENS OFF TO THE NORTHEAST EARLY SATURDAY...AND HIGH PRESSURE BEGINS TO BUILD EASTWARD ACROSS THE PLAINS...THE COMBINATION OF A TIGHTENING SURFACE PRESSURE GRADIENT AND LOW LEVEL COLD AIR ADVECTION IS EXPECTED TO LEAD TO A BRIEF PERIOD OF 30-35 KT WINDS OVER THE LAKE. GALE FORCE WINDS APPEAR TO BE MOST LIKELY ACROSS CENTRAL AND SOUTHERN LAKE MICHIGAN FROM THE PREDAWN HOURS THROUGH MID-LATE MORNING SATURDAY. WINDS WILL THEN QUICKLY DIMINISH LATER SATURDAY AFTERNOON AND NIGHT AS THE SURFACE HIGH MOVES INTO THE REGION. BEYOND SATURDAY...THE WEATHER PATTERN LOOKS TO REMAIN FAIRLY QUIET WITH THE TRAILING WESTERN PERIPHERY OF THE SURFACE RIDGE AXIS REMAINING OVER THE CENTRAL OR SOUTHERN PART OF THE LAKE...WHILE AN AREA OF LOW PRESSURE PASSES WELL NORTH OF THE LAKES THROUGH MID- WEEK. THIS WILL LIKELY RESULT IN MODEST SOUTH- SOUTHWEST WINDS INCREASING A BIT ON THE NORTH END OF THE LAKE AND PERHAPS GUSTING 15-20 KTS AT TIMES...WHILE REMAINING LIGHTER FARTHER SOUTH. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022 UNTIL 7 AM SATURDAY. BEACH HAZARDS STATEMENT...ILZ006-ILZ014...4 AM SATURDAY TO 10 PM SATURDAY. IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...4 AM SATURDAY TO 10 PM SATURDAY. LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...4 AM SATURDAY TO 1 PM SATURDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1234 PM CDT THU SEP 17 2015 .UPDATE... ISSUED AT 1045 AM CDT THU SEP 17 2015 At 1035am broken clouds are covering parts of eastern IL late this morning. HiRes/short range models continue to show some scattered light pcpn in the east, but just over the next couple of hours. Believe those models not handling pcpn fields well, as they do not have the larger area of pcpn in central and eastern Iowa. So will making some adjustments to pops and removing slight chances for the area and then adding some chance pops late this afternoon in the northwest to account for area in eastern IA possibly spreading south into extreme northwestern parts of the cwa. Remainder of forecast looks fine. Update will be out shortly. && .SHORT TERM...(TODAY) ISSUED AT 335 AM CDT THU SEP 17 2015 The approaching cold front from the Plains will cause increasing southerly flow in the lower troposphere, raising moisture levels across the forecast area. Warm air advection showers are already nearing western IL from Iowa/Missouri at 08z, and the HRRR and RAP models show spotty showers advancing across our counties west of I- 55 this morning. Most spots will just see sprinkles, but a few locations could get measurable rain under convective updrafts. Therefore, we advanced slight chance PoPs into the western counties over several hours this morning, then diminished just after Noon. A return of slight chances for Knox and Stark counties is expected after 3 pm/20z as a shortwave/low pressure begin to move northeast along the front into Iowa. Depending on cloud cover, high temps should climb to at or above yesterdays very warm readings in the mid to upper 80s in the west, with mid 80s in the east. Held off on low 90s, due to periodic cloud cover limiting full warming potential. South winds will become gusty today ahead of the cold front, with sustained speeds of 15-20 mph, and gusts into the mid to upper 20 mph range this afternoon. .LONG TERM...(TONIGHT THROUGH Wednesday) ISSUED AT 335 AM CDT THU SEP 17 2015 Beyond today, the remaining of the forecast has a lot of agreement in the models overall. The precipitation chances increase tonight as the front gets closer to the region. The front slows a bit tomorrow as it runs into mostly parallel flow out of the southwest, but starts to break down the ridge over the eastern half of the country. There is the potential for a bit of a break on Friday...but that will depend highly on mesoscale features and cloud cover during the day...and keeping the forecast to chance pops a a result. The second wave is expected to bring increasing pops tomorrow night with the actual fropa and wind shift coming in the early morning hours for Saturday. Northwesterly winds for Saturday and lower max temps in the upper 60s in the northern portions of the state, Central Illinois in the 70s. More widespread 70s expected for Sunday afternoon to wrap up the weekend. So far, the mid level temps in the models are not pointing to a deep chill behind the cold front. Although a few degrees below normal briefly, a general warming trend will have Central Illinois back to climatological norms by midweek. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON) ISSUED AT 1234 PM CDT THU SEP 17 2015 Challenging forecast for the TAFs this afternoon as models not handling ongoing pcpn all that well and lots of uncertainty with what will transpire tonight. Thinking that current pcpn in eastern IA will remain north of PIA/BMI this afternoon/evening. Believe trend will be for line of showers and storms to move through the TAFs after midnight. So will keep VFR conditions going this afternoon with scattered clouds around 5kft. Then broken mid clouds around 12kft, remnants of convection to the northwest, will advect into the area this evening. Will then bring vcts into the TAFs starting at 06z at PIA and then progressing eastward overnight...lasting about 3hrs at each site. Then by morning, scattered clouds around 5kft and a broken mid deck is expected. winds should remain southerly through the period with gusts this afternoon, just over 20kts. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Auten SHORT TERM...Shimon LONG TERM...HJS AVIATION...Auten
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT THU SEP 17 2015 .UPDATE... ISSUED AT 1045 AM CDT THU SEP 17 2015 At 1035am broken clouds are covering parts of eastern IL late this morning. HiRes/short range models continue to show some scattered light pcpn in the east, but just over the next couple of hours. Believe those models not handling pcpn fields well, as they do not have the larger area of pcpn in central and eastern Iowa. So will making some adjustments to pops and removing slight chances for the area and then adding some chance pops late this afternoon in the northwest to account for area in eastern IA possibly spreading south into extreme northwestern parts of the cwa. Remainder of forecast looks fine. Update will be out shortly. && .SHORT TERM...(TODAY) ISSUED AT 335 AM CDT THU SEP 17 2015 The approaching cold front from the Plains will cause increasing southerly flow in the lower troposphere, raising moisture levels across the forecast area. Warm air advection showers are already nearing western IL from Iowa/Missouri at 08z, and the HRRR and RAP models show spotty showers advancing across our counties west of I- 55 this morning. Most spots will just see sprinkles, but a few locations could get measurable rain under convective updrafts. Therefore, we advanced slight chance PoPs into the western counties over several hours this morning, then diminished just after Noon. A return of slight chances for Knox and Stark counties is expected after 3 pm/20z as a shortwave/low pressure begin to move northeast along the front into Iowa. Depending on cloud cover, high temps should climb to at or above yesterdays very warm readings in the mid to upper 80s in the west, with mid 80s in the east. Held off on low 90s, due to periodic cloud cover limiting full warming potential. South winds will become gusty today ahead of the cold front, with sustained speeds of 15-20 mph, and gusts into the mid to upper 20 mph range this afternoon. .LONG TERM...(TONIGHT THROUGH Wednesday) ISSUED AT 335 AM CDT THU SEP 17 2015 Beyond today, the remaining of the forecast has a lot of agreement in the models overall. The precipitation chances increase tonight as the front gets closer to the region. The front slows a bit tomorrow as it runs into mostly parallel flow out of the southwest, but starts to break down the ridge over the eastern half of the country. There is the potential for a bit of a break on Friday...but that will depend highly on mesoscale features and cloud cover during the day...and keeping the forecast to chance pops a a result. The second wave is expected to bring increasing pops tomorrow night with the actual fropa and wind shift coming in the early morning hours for Saturday. Northwesterly winds for Saturday and lower max temps in the upper 60s in the northern portions of the state, Central Illinois in the 70s. More widespread 70s expected for Sunday afternoon to wrap up the weekend. So far, the mid level temps in the models are not pointing to a deep chill behind the cold front. Although a few degrees below normal briefly, a general warming trend will have Central Illinois back to climatological norms by midweek. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING) ISSUED AT 700 AM CDT THU SEP 17 2015 Predominantly VFR aviation weather conditions expected across the central Illinois terminals today through 00z/7pm. Clouds will increase for the western terminals of PIA, BMI and SPI as moisture increases ahead of a slowly approaching cold front. A few sprinkles will even be possible today for PIA, BMI and SPI based on the several high resolution models, but little aviation impact is expected. Chances of showers or thunderstorms will increase during the evening. After midnight, storms will become likely west of I-55, including PIA/BMI/SPI. IFR conditions will be possible during any storms. Once again, southerly winds will persist through the period, with winds gusting to around 25 kts during the peak diurnal mixing times today, them remaining 10-12kt tonight. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Auten SHORT TERM...Shimon LONG TERM...HJS AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS LINCOLN IL
702 AM CDT THU SEP 17 2015 .SHORT TERM...(TODAY) ISSUED AT 335 AM CDT THU SEP 17 2015 The approaching cold front from the Plains will cause increasing southerly flow in the lower troposphere, raising moisture levels across the forecast area. Warm air advection showers are already nearing western IL from Iowa/Missouri at 08z, and the HRRR and RAP models show spotty showers advancing across our counties west of I- 55 this morning. Most spots will just see sprinkles, but a few locations could get measurable rain under convective updrafts. Therefore, we advanced slight chance PoPs into the western counties over several hours this morning, then diminished just after Noon. A return of slight chances for Knox and Stark counties is expected after 3 pm/20z as a shortwave/low pressure begin to move northeast along the front into Iowa. Depending on cloud cover, high temps should climb to at or above yesterdays very warm readings in the mid to upper 80s in the west, with mid 80s in the east. Held off on low 90s, due to periodic cloud cover limiting full warming potential. South winds will become gusty today ahead of the cold front, with sustained speeds of 15-20 mph, and gusts into the mid to upper 20 mph range this afternoon. .LONG TERM...(TONIGHT THROUGH Wednesday) ISSUED AT 335 AM CDT THU SEP 17 2015 Beyond today, the remaining of the forecast has a lot of agreement in the models overall. The precipitation chances increase tonight as the front gets closer to the region. The front slows a bit tomorrow as it runs into mostly parallel flow out of the southwest, but starts to break down the ridge over the eastern half of the country. There is the potential for a bit of a break on Friday...but that will depend highly on mesoscale features and cloud cover during the day...and keeping the forecast to chance pops a a result. The second wave is expected to bring increasing pops tomorrow night with the actual fropa and wind shift coming in the early morning hours for Saturday. Northwesterly winds for Saturday and lower max temps in the upper 60s in the northern portions of the state, Central Illinois in the 70s. More widespread 70s expected for Sunday afternoon to wrap up the weekend. So far, the mid level temps in the models are not pointing to a deep chill behind the cold front. Although a few degrees below normal briefly, a general warming trend will have Central Illinois back to climatological norms by midweek. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING) ISSUED AT 700 AM CDT THU SEP 17 2015 Predominantly VFR aviation weather conditions expected across the central Illinois terminals today through 00z/7pm. Clouds will increase for the western terminals of PIA, BMI and SPI as moisture increases ahead of a slowly approaching cold front. A few sprinkles will even be possible today for PIA, BMI and SPI based on the several high resolution models, but little aviation impact is expected. Chances of showers or thunderstorms will increase during the evening. After midnight, storms will become likely west of I-55, including PIA/BMI/SPI. IFR conditions will be possible during any storms. Once again, southerly winds will persist through the period, with winds gusting to around 25 kts during the peak diurnal mixing times today, them remaining 10-12kt tonight. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Shimon LONG TERM...HJS AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS LINCOLN IL
335 AM CDT THU SEP 17 2015 .SHORT TERM...(TODAY) ISSUED AT 335 AM CDT THU SEP 17 2015 The approaching cold front from the Plains will cause increasing southerly flow in the lower troposphere, raising moisture levels across the forecast area. Warm air advection showers are already nearing western IL from Iowa/Missouri at 08z, and the HRRR and RAP models show spotty showers advancing across our counties west of I- 55 this morning. Most spots will just see sprinkles, but a few locations could get measurable rain under convective updrafts. Therefore, we advanced slight chance PoPs into the western counties over several hours this morning, then diminished just after Noon. A return of slight chances for Knox and Stark counties is expected after 3 pm/20z as a shortwave/low pressure begin to move northeast along the front into Iowa. Depending on cloud cover, high temps should climb to at or above yesterdays very warm readings in the mid to upper 80s in the west, with mid 80s in the east. Held off on low 90s, due to periodic cloud cover limiting full warming potential. South winds will become gusty today ahead of the cold front, with sustained speeds of 15-20 mph, and gusts into the mid to upper 20 mph range this afternoon. && .LONG TERM...(TONIGHT THROUGH Wednesday) ISSUED AT 335 AM CDT THU SEP 17 2015 Beyond today, the remaining of the forecast has a lot of agreement in the models overall. The precipitation chances increase tonight as the front gets closer to the region. The front slows a bit tomorrow as it runs into mostly parallel flow out of the southwest, but starts to break down the ridge over the eastern half of the country. There is the potential for a bit of a break on Friday...but that will depend highly on mesoscale features and cloud cover during the day...and keeping the forecast to chance pops a a result. The second wave is expected to bring increasing pops tomorrow night with the actual fropa and wind shift coming in the early morning hours for Saturday. Northwesterly winds for Saturday and lower max temps in the upper 60s in the northern portions of the state, Central Illinois in the 70s. More widespread 70s expected for Sunday afternoon to wrap up the weekend. So far, the mid level temps in the models are not pointing to a deep chill behind the cold front. Although a few degrees below normal briefly, a general warming trend will have Central Illinois back to climatological norms by midweek. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Thursday NIGHT) ISSUED AT 1148 PM CDT WED SEP 16 2015 Predominantly VFR aviation weather conditions expected across the central Illinois terminals through the 06Z TAF valid time. In fact, most of the first half of the forecast period should see little, if any, cloud cover. Eventually clouds will slowly increase from the west with the approach of a slow moving cold front. A few showers or thunderstorms are possible during the evening hours, but coverage is expected to be too low to go above a VCSH mention. Better precipitation chances will arrive after 06Z Friday. Once again, southerly winds will persist through the period, with winds gusting to around 20 kts during the peak diurnal mixing times Thursday. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Shimon LONG TERM...HJS AVIATION...Bak
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1248 PM CDT THU SEP 17 2015 ...Update to aviation forecast discussion... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 340 AM CDT THU SEP 17 2015 An upper level trough was deepening across the eastern Pacific and the western CONUS at 08Z. A stronger shortwave trough was moving onshore into Washington state while an upper level ridge continued across the southern Plains into the western Gulf with southwesterly upper flow across the Central Plains. A few embedded waves were moving across the Northern Plains early this morning. Isentropic lift in the 315K-320K layer was developing a few isolated showers in north central and northeast Kansas. Short range hi resolution models, including the experimental HRRR show isolated to scattered elevated convection across the forecast area, but mainly focusing across northeast Kansas by sunrise. A frontal boundary was located from central South Dakota to a low pressure area in southwest Nebraska then into eastern Colorado. A trough moving across the Northern Plains today should push the front southeast into north central Kansas later this afternoon then extend from Hiawatha to Abilene by late evening. The front looks to stall out across the forecast area after midnight from northwest Missouri into south central Kansas. Expect the isolated showers and thunderstorms through the morning hours before moving off to the northeast. Expect a break for much of the afternoon as there is little in the way of any lift and convergence along the front is expected to be weak and forecast soundings show EML capping surface convection for the afternoon. That said convective inhibition will begin to wane late in the day and have maintained increasing pops along the frontal zone. Tonight the low level jet will be orientated parallel to the frontal boundary with the pooling of moisture near the front, especially in northeast Kansas initially before shifting to the southeast through the night. Isentropic lift and convergence are also initially focused in the northeast and into northwest Missouri then shifts southward through the night into east central Kansas. Shear and instability will be sufficient for a few strong to severe storms tonight. Locally heavy rainfall is also possible where storms train along the boundary. Mixing to around 850 mb today will make for highs in the upper 80s to mid 90s. Lows tonight will cool into the 60s north of the front and lower 70s to its south. .LONG TERM...(Friday THROUGH Wednesday) ISSUED AT 340 AM CDT THU SEP 17 2015 By Friday morning, the cold front should be stretched across the southeastern portion of the CWA and lift a bit to the north through the morning hours. This front finally will progress eastward through the afternoon and evening hours as the secondary mid-level trough sweeps into the Northern and Central Plains, thus helping to push this system eastward out of the area. Models show that we may lose some of the available lift during the morning hours on Friday, so there may only be some scattered morning showers and thunderstorms. However, thunderstorm potential looks to increase during the afternoon hours and into the evening as the forcing/lift increases across the area with the progressing front and support from the mid- level trough approaching the area. Soundings show the cap potentially eroding away by mid-afternoon, when the front should be nearly bisecting the CWA from southwest to northeast. This available lift/forcing combined with limited inhibition by mid-afternoon, CAPE values increasing to upwards of around 2000 J/kg, and 0-6 km bulk shear values increasing to at least 35-40kts, should result in the potential for some severe thunderstorm development mid Friday afternoon into Friday evening. While the primary hazards will be damaging winds and large hail, 0-1 km shear and helicity values suggest even the potential for a few isolated tornadoes as well. While these afternoon storms should be a bit more progressive, with PWAT values in the 1.7-1.9 inch range and the low/mid level jets expected to be nearly parallel to the boundary, cannot rule out the potential for some locally heavy rain that could potentially lead to some localized flash flooding. The severe threat should diminish by late evening with a dry forecast in place for the entire CWA by the overnight hours (early Saturday morning). Surface high pressure will surge into the central U.S. behind the exiting system, ushering cooler air into the region. Have continued to trend a bit cooler for high temperatures on Saturday as northerly winds may only allow afternoon highs to reach into the low/mid 70s. Lows Saturday night should drop into the low 50s. Winds will shift around to the southeast by Sunday, pushing highs a few degrees higher into the mid/upper 70s. Models continue to show an embedded shortwave trough developing within the mid-level flow over the central U.S. on Sunday, however the best moisture and lift look to remain further south of the CWA so have kept a dry forecast for Sunday. A mid-level ridge will build back into the Southern and Central Plains by early next week. With surface high pressure shifting east of the area, southerly winds will help to gradually moderate high temperatures into the low/mid 80s by Tuesday. Models start diverging in their solutions by mid-week as the GFS develops an embedded wave along the western ridge axis that could potentially result in some precipitation skimming the CWA, while the ECMWF keeps the area dry. While confidence is low in the precip potential, have only some low- end slight chance PoPs in for Wednesday night into Thursday. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON) ISSUED AT 1236 PM CDT THU SEP 17 2015 Expect VFR conditions this afternoon at all terminals. This evening, an unsettled period will enter into the forecast. Low confidence in areas of thunderstorm development have prompted the mention of VCTS. Do believe that there will be essentially two periods of storms, so have not used a blanket VCTS for the entire period. The general trend and model consensus does appear to hint towards a slow Eastward progression of the low and associated boundaries over the next 24 hours or so. This led to opting not to carry a storm chance for the KMHK terminal after the 12z time frame. It still remains possible that subsequent forecasts may need to insert storms back into the forecast for the morning. Additionally, with the overall synoptic setup in place, not expecting the LLJ to be as strong over the terminals and therefore not as concerned that windshear will be a major impact at this time. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...Hennecke AVIATION...Drake
AREA FORECAST DISCUSSION
NWS TOPEKA KS
640 AM CDT THU SEP 17 2015 ...Update to aviation forecast discussion... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 340 AM CDT THU SEP 17 2015 An upper level trough was deepening across the eastern Pacific and the western CONUS at 08Z. A stronger shortwave trough was moving onshore into Washington state while an upper level ridge continued across the southern Plains into the western Gulf with southwesterly upper flow across the Central Plains. A few embedded waves were moving across the Northern Plains early this morning. Isentropic lift in the 315K-320K layer was developing a few isolated showers in north central and northeast Kansas. Short range hi resolution models, including the experimental HRRR show isolated to scattered elevated convection across the forecast area, but mainly focusing across northeast Kansas by sunrise. A frontal boundary was located from central South Dakota to a low pressure area in southwest Nebraska then into eastern Colorado. A trough moving across the Northern Plains today should push the front southeast into north central Kansas later this afternoon then extend from Hiawatha to Abilene by late evening. The front looks to stall out across the forecast area after midnight from northwest Missouri into south central Kansas. Expect the isolated showers and thunderstorms through the morning hours before moving off to the northeast. Expect a break for much of the afternoon as there is little in the way of any lift and convergence along the front is expected to be weak and forecast soundings show EML capping surface convection for the afternoon. That said convective inhibition will begin to wane late in the day and have maintained increasing pops along the frontal zone. Tonight the low level jet will be orientated parallel to the frontal boundary with the pooling of moisture near the front, especially in northeast Kansas initially before shifting to the southeast through the night. Isentropic lift and convergence are also initially focused in the northeast and into northwest Missouri then shifts southward through the night into east central Kansas. Shear and instability will be sufficient for a few strong to severe storms tonight. Locally heavy rainfall is also possible where storms train along the boundary. Mixing to around 850 mb today will make for highs in the upper 80s to mid 90s. Lows tonight will cool into the 60s north of the front and lower 70s to its south. .LONG TERM...(Friday THROUGH Wednesday) ISSUED AT 340 AM CDT THU SEP 17 2015 By Friday morning, the cold front should be stretched across the southeastern portion of the CWA and lift a bit to the north through the morning hours. This front finally will progress eastward through the afternoon and evening hours as the secondary mid-level trough sweeps into the Northern and Central Plains, thus helping to push this system eastward out of the area. Models show that we may lose some of the available lift during the morning hours on Friday, so there may only be some scattered morning showers and thunderstorms. However, thunderstorm potential looks to increase during the afternoon hours and into the evening as the forcing/lift increases across the area with the progressing front and support from the mid- level trough approaching the area. Soundings show the cap potentially eroding away by mid-afternoon, when the front should be nearly bisecting the CWA from southwest to northeast. This available lift/forcing combined with limited inhibition by mid-afternoon, CAPE values increasing to upwards of around 2000 J/kg, and 0-6 km bulk shear values increasing to at least 35-40kts, should result in the potential for some severe thunderstorm development mid Friday afternoon into Friday evening. While the primary hazards will be damaging winds and large hail, 0-1 km shear and helicity values suggest even the potential for a few isolated tornadoes as well. While these afternoon storms should be a bit more progressive, with PWAT values in the 1.7-1.9 inch range and the low/mid level jets expected to be nearly parallel to the boundary, cannot rule out the potential for some locally heavy rain that could potentially lead to some localized flash flooding. The severe threat should diminish by late evening with a dry forecast in place for the entire CWA by the overnight hours (early Saturday morning). Surface high pressure will surge into the central U.S. behind the exiting system, ushering cooler air into the region. Have continued to trend a bit cooler for high temperatures on Saturday as northerly winds may only allow afternoon highs to reach into the low/mid 70s. Lows Saturday night should drop into the low 50s. Winds will shift around to the southeast by Sunday, pushing highs a few degrees higher into the mid/upper 70s. Models continue to show an embedded shortwave trough developing within the mid-level flow over the central U.S. on Sunday, however the best moisture and lift look to remain further south of the CWA so have kept a dry forecast for Sunday. A mid-level ridge will build back into the Southern and Central Plains by early next week. With surface high pressure shifting east of the area, southerly winds will help to gradually moderate high temperatures into the low/mid 80s by Tuesday. Models start diverging in their solutions by mid-week as the GFS develops an embedded wave along the western ridge axis that could potentially result in some precipitation skimming the CWA, while the ECMWF keeps the area dry. While confidence is low in the precip potential, have only some low- end slight chance PoPs in for Wednesday night into Thursday. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING) ISSUED AT 640 AM CDT THU SEP 17 2015 Isolated showers and thunderstorms will affect the terminals this morning, first at MHK then FOE and TOP after 14Z. Kept low level wind shear at TOP and FOE through 14Z. Approach of a cold front will have some scattered tsra after 23Z and continue through the end of the period. For now have gone with VCTS. Winds shift to the north at MHK after 03Z. Front likely to not move through TOP and FOE attm so southerly winds should continue. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...Hennecke AVIATION...53
AREA FORECAST DISCUSSION
NWS TOPEKA KS
343 AM CDT THU SEP 17 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 340 AM CDT THU SEP 17 2015 An upper level trough was deepening across the eastern Pacific and the western CONUS at 08Z. A stronger shortwave trough was moving onshore into Washington state while an upper level ridge continued across the southern Plains into the western Gulf with southwesterly upper flow across the Central Plains. A few embedded waves were moving across the Northern Plains early this morning. Isentropic lift in the 315K-320K layer was developing a few isolated showers in north central and northeast Kansas. Short range hi resolution models, including the experimental HRRR show isolated to scattered elevated convection across the forecast area, but mainly focusing across northeast Kansas by sunrise. A frontal boundary was located from central South Dakota to a low pressure area in southwest Nebraska then into eastern Colorado. A trough moving across the Northern Plains today should push the front southeast into north central Kansas later this afternoon then extend from Hiawatha to Abilene by late evening. The front looks to stall out across the forecast area after midnight from northwest Missouri into south central Kansas. Expect the isolated showers and thunderstorms through the morning hours before moving off to the northeast. Expect a break for much of the afternoon as there is little in the way of any lift and convergence along the front is expected to be weak and forecast soundings show EML capping surface convection for the afternoon. That said convective inhibition will begin to wane late in the day and have maintained increasing pops along the frontal zone. Tonight the low level jet will be orientated parallel to the frontal boundary with the pooling of moisture near the front, especially in northeast Kansas initially before shifting to the southeast through the night. Isentropic lift and convergence are also initially focused in the northeast and into northwest Missouri then shifts southward through the night into east central Kansas. Shear and instability will be sufficient for a few strong to severe storms tonight. Locally heavy rainfall is also possible where storms train along the boundary. Mixing to around 850 mb today will make for highs in the upper 80s to mid 90s. Lows tonight will cool into the 60s north of the front and lower 70s to its south. .LONG TERM...(Friday THROUGH Wednesday) ISSUED AT 340 AM CDT THU SEP 17 2015 By Friday morning, the cold front should be stretched across the southeastern portion of the CWA and lift a bit to the north through the morning hours. This front finally will progress eastward through the afternoon and evening hours as the secondary mid-level trough sweeps into the Northern and Central Plains, thus helping to push this system eastward out of the area. Models show that we may lose some of the available lift during the morning hours on Friday, so there may only be some scattered morning showers and thunderstorms. However, thunderstorm potential looks to increase during the afternoon hours and into the evening as the forcing/lift increases across the area with the progressing front and support from the mid- level trough approaching the area. Soundings show the cap potentially eroding away by mid-afternoon, when the front should be nearly bisecting the CWA from southwest to northeast. This available lift/forcing combined with limited inhibition by mid-afternoon, CAPE values increasing to upwards of around 2000 J/kg, and 0-6 km bulk shear values increasing to at least 35-40kts, should result in the potential for some severe thunderstorm development mid Friday afternoon into Friday evening. While the primary hazards will be damaging winds and large hail, 0-1 km shear and helicity values suggest even the potential for a few isolated tornadoes as well. While these afternoon storms should be a bit more progressive, with PWAT values in the 1.7-1.9 inch range and the low/mid level jets expected to be nearly parallel to the boundary, cannot rule out the potential for some locally heavy rain that could potentially lead to some localized flash flooding. The severe threat should diminish by late evening with a dry forecast in place for the entire CWA by the overnight hours (early Saturday morning). Surface high pressure will surge into the central U.S. behind the exiting system, ushering cooler air into the region. Have continued to trend a bit cooler for high temperatures on Saturday as northerly winds may only allow afternoon highs to reach into the low/mid 70s. Lows Saturday night should drop into the low 50s. Winds will shift around to the southeast by Sunday, pushing highs a few degrees higher into the mid/upper 70s. Models continue to show an embedded shortwave trough developing within the mid-level flow over the central U.S. on Sunday, however the best moisture and lift look to remain further south of the CWA so have kept a dry forecast for Sunday. A mid-level ridge will build back into the Southern and Central Plains by early next week. With surface high pressure shifting east of the area, southerly winds will help to gradually moderate high temperatures into the low/mid 80s by Tuesday. Models start diverging in their solutions by mid-week as the GFS develops an embedded wave along the western ridge axis that could potentially result in some precipitation skimming the CWA, while the ECMWF keeps the area dry. While confidence is low in the precip potential, have only some low- end slight chance PoPs in for Wednesday night into Thursday. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Thursday NIGHT) ISSUED AT 1141 PM CDT WED SEP 16 2015 Low level wind shear will continue through the overnight hours although occasional gusts at the surface will be possible as well. Isolated showers with perhaps thunder will develop during the predawn hours and move eastward towards the taf sites. A cold front will approach later this evening. Isolated storms could develop along the front near MHK after sunset. Brief heavy rain and gusty winds can not be ruled out with any storm. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...Hennecke AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
636 PM EDT THU SEP 17 2015 .SYNOPSIS... RAIN CHANCES WILL INCREASE AS A COLD FRONT MOVES OUT OF THE MIDWEST THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... SURFACE HIGH PRESSURE WILL CONTINUE TO BE THE CONTROLLING FACTOR FOR OUR WEATHER OVERNIGHT...EVEN AS THE CENTER OF THE HIGH STARTS TO MOVE EAST OF THE APPALACHIAN FRONT. WHILE THIS WILL ALLOW FOR SOUTH GRADIENT FLOW FROM THE SOUTHWEST IN THE LOW LEVELS...SURFACE OBSERVATIONS AND RAP SOUNDINGS ALREADY INDICATE DIURNAL MIXING IS WANING. AS A RESULT...SURFACE FLOW WILL LIKELY DROP TO NIL WITHIN THE NEXT COUPLE OF HOURS. THIS WILL YIELD CLEAR SKIES OVERNIGHT DUE TO A DEARTH OF LAYER MOISTURE...AND VERY WEAK BOUNDARY LAYER FLOW. THIS WILL BASICALLY MEAN THAT TEMPERATURES WILL HAVE THEIR EYES SET ON THE DEWPOINTS FORTHWITH AS THEY FALL AGGRESSIVELY INTO THE LATER EVENING. AND DUE TO THE LENGTH IN THE NIGHTS GOING INTO THE FALL...DIURNAL DROPS AFTER A WARM DAY GET TO BE EASIER TO ACCOMPLISH. THE ONLY INFINITESIMALLY DIFFICULT PART OF THE FORECAST IS HOW TO HANDLE THE DEWPOINT FORECAST. THERE IS A WINDOW OF SLIGHTLY LOWER DEWPOINTS IN EASTERN INDIANA AND WESTERN OHIO...WHERE VALUES ARE STRADDLING THE 50F MARK. HRRR GUIDANCE IS EXHIBITING ITS TYPICAL DRY AFTERNOON BIAS DUE TO IRRATIONAL MIXING...AND WITH INVERSIONS READY TO SET UP FAIRLY SHORTLY...THE WINDOW FOR GETTING DRIER AIR INTO THE BOUNDARY LAYER IN OUR CWA IS QUICKLY CLOSING. THIS LEAVES US WITH GENERALLY LOWER TO MIDDLE 50S ACROSS THE CWA...AND WHILE A BIT OF THAT MOISTURE MAY BE REMOVED BY DEW DEPOSITION...IT SEEMS UNLIKELY THAT LOWS WILL BREACH 50F ON AN ORGANIZED BASIS MUCH OF ANYWHERE EXCEPT IN THE LOWEST VALLEYS AMONGST THE RIDGES. THERMAL BELTS WILL LIKELY BE PRONOUNCED IN THE HIGHER TERRAIN...MUCH LIKE LAST NIGHT...YIELDING INVERTED TEMPERATURE GRIDS OVER THE RIDGES. ELSEWHERE...THE URBAN HEAT ISLAND SEEMS LIKELY TO BE A BIT STRONGER AROUND PITTSBURGH THAN LAST NIGHT DUE TO THE INSOLATION TODAY...HOWEVER OUTSIDE OF THERE...LOWS WILL PROBABLY ONLY BE UP A COUPLE OF DEGREES FROM LAST NIGHT. FRIES && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... THE LAST COUPLE MODEL RUNS HAVE PRODUCED SOME LIGHT PRECIP WITH A LEAD SHORTWAVE MOVING OUT OF THE MIDWEST LATE ON FRIDAY. HAVE DECIDED TO INCLUDE A SLIGHT PRECIP PROB OVER EXTREME NWRN...AND WRN ZONES FOR THIS FEATURE...ALTHOUGH LOW LEVEL LAYERS ARE LIKELY TO BE SLOW MOISTENING SUFFICIENTLY. MAY END UP MORE OF A SPRINKLE SITUATION. OTHERWISE...AN AFTERNOON AND EVENING MID LEVEL CLOUD INCREASE CAN BE EXPECTED. THE BETTER PRECIP CHANCE WILL STILL BE WITH THE LATE SATURDAY COLD FRONT...POPS FOR WHICH WERE INCREASED AND ADJUSTED FOR THE QUICKER TIMING OF THE LATEST GFS AND NAM TRENDS. NUMBERS WERE STILL LIMITED TO THE CHANCE CATEGORY FOR NOW GIVEN OMEGA BULLSEYE QUESTIONS AND EXPECTATIONS THAT MODEL-WORLD BOUNDARY MOISTURE MAY BE TOO HIGH. PROGGED INSTABILITY IS THUS ALSO LIKELY TO BE HIGH...AND WOULD NOT SUPPORT SEVERE STORMS DESPITE THE INCREASING DEEP LAYER SHEAR IN THE TIGHTENING PRESSURE GRADIENT. PASSAGE OF THE FRONT WILL DROP TEMPS BACK TO THE SEASONAL AVERAGES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... BUILDING HIGH PRESSURE IS THEN PROJECTED TO BRING DRY AND SEASONAL CONDITIONS SUNDAY AND MONDAY. THEREAFTER...FORECAST CONFIDENCE DROPS QUICKLY AS DIFFERING MODEL SOLUTIONS PROVIDE NO CLEAR PICTURE FOR THE END OF THE LONG TERM. THE FORECAST WAS THUS BASED ON PERSISTENCE WITH ONLY MINOR CHANGES TO TUESDAY AND WEDNESDAY. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE WILL MAINTAIN VFR WITH EXCEPTIONS OF BRIEF DAWN FOG. HAVE GONE WITH PERSISTENCE FORECASTS FROM THIS MORNINGS OBSERVATIONS AT HLG/FKL/DUJ. OUTLOOK...FRIDAY NIGHT THROUGH TUESDAY... THE NEXT CHANCE FOR GENERAL RESTRICTIONS WILL COME WITH A LATE SATURDAY COLD FRONT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
530 PM EDT THU SEP 17 2015 .SYNOPSIS... RAIN CHANCES WILL INCREASE AS A COLD FRONT MOVES OUT OF THE MIDWEST THIS WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... SURFACE HIGH PRESSURE WILL CONTINUE TO BE THE CONTROLLING FACTOR FOR OUR WEATHER OVERNIGHT...EVEN AS THE CENTER OF THE HIGH STARTS TO MOVE EAST OF THE APPALACHIAN FRONT. WHILE THIS WILL ALLOW FOR SOUTH GRADIENT FLOW FROM THE SOUTHWEST IN THE LOW LEVELS...SURFACE OBSERVATIONS AND RAP SOUNDINGS ALREADY INDICATE DIURNAL MIXING IS WANING. AS A RESULT...SURFACE FLOW WILL LIKELY DROP TO NIL WITHIN THE NEXT COUPLE OF HOURS. THIS WILL YIELD CLEAR SKIES OVERNIGHT DUE TO A DEARTH OF LAYER MOISTURE...AND VERY WEAK BOUNDARY LAYER FLOW. THIS WILL BASICALLY MEAN THAT TEMPERATURES WILL HAVE THERE EYES SET ON THE DEWPOINTS FORTHWITH AS THEY FALL AGGRESSIVELY INTO THE LATER EVENING. AND DUE TO THE LENGTH IN THE NIGHTS GOING INTO THE FALL...DIURNAL DROPS AFTER A WARM DAY GET TO BE EASIER TO ACCOMPLISH. THE ONLY INFINITESIMALLY DIFFICULT PART OF THE FORECAST IS HOW TO HANDLE THE DEWPOINT FORECAST. THERE IS A WINDOW OF SLIGHTLY LOWER DEWPOINTS IN EASTERN INDIANA AND WESTERN OHIO...WHERE VALUES ARE STRADDLING THE 50F MARK. HRRR GUIDANCE IS EXHIBITING ITS TYPICAL DRY AFTERNOON BIAS DUE TO IRRATIONAL MIXING...AND WITH INVERSIONS READY TO SET UP FAIRLY SHORTLY...THE WINDOW FOR GETTING DRIER AIR INTO THE BOUNDARY LAYER IN OUR CWA IS QUICKLY CLOSING. THIS LEAVES US WITH GENERALLY LOWER TO MIDDLE 50S ACROSS THE CWA...AND WHILE A BIT OF THAT MOISTURE MAY BE REMOVED BY DEW DEPOSITION...IT SEEMS UNLIKELY THAT LOWS WILL BREACH 50F ON AN ORGANIZED BASIS MUCH OF ANYWHERE EXCEPT IN THE LOWEST VALLEYS AMONGST THE RIDGES. THERMAL BELTS WILL LIKELY BE PRONOUNCED IN THE HIGHER TERRAIN...MUCH LIKE LAST NIGHT...YIELDING INVERTED TEMPERATURE GRIDS OVER THE RIDGES. ELSEWHERE...THE URBAN HEAT ISLAND SEEMS LIKELY TO BE A BIT STRONGER AROUND PITTSBURGH THAN LAST NIGHT DUE TO THE INSOLATION TODAY...HOWEVER OUTSIDE OF THERE...LOWS WILL PROBABLY ONLY BE UP A COUPLE OF DEGREES FROM LAST NIGHT. FRIES && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... THE LAST COUPLE MODEL RUNS HAVE PRODUCED SOME LIGHT PRECIP WITH A LEAD SHORTWAVE MOVING OUT OF THE MIDWEST LATE ON FRIDAY. HAVE DECIDED TO INCLUDE A SLIGHT PRECIP PROB OVER EXTREME NWRN...AND WRN ZONES FOR THIS FEATURE...ALTHOUGH LOW LEVEL LAYERS ARE LIKELY TO BE SLOW MOISTENING SUFFICIENTLY. MAY END UP MORE OF A SPRINKLE SITUATION. OTHERWISE...AN AFTERNOON AND EVENING MID LEVEL CLOUD INCREASE CAN BE EXPECTED. THE BETTER PRECIP CHANCE WILL STILL BE WITH THE LATE SATURDAY COLD FRONT...POPS FOR WHICH WERE INCREASED AND ADJUSTED FOR THE QUICKER TIMING OF THE LATEST GFS AND NAM TRENDS. NUMBERS WERE STILL LIMITED TO THE CHANCE CATEGORY FOR NOW GIVEN OMEGA BULLSEYE QUESTIONS AND EXPECTATIONS THAT MODEL-WORLD BOUNDARY MOISTURE MAY BE TOO HIGH. PROGGED INSTABILITY IS THUS ALSO LIKELY TO BE HIGH...AND WOULD NOT SUPPORT SEVERE STORMS DESPITE THE INCREASING DEEP LAYER SHEAR IN THE TIGHTENING PRESSURE GRADIENT. PASSAGE OF THE FRONT WILL DROP TEMPS BACK TO THE SEASONAL AVERAGES. && .LONG TERM /SUNDAY THROUGH THURSDAY/... BUILDING HIGH PRESSURE IS THEN PROJECTED TO BRING DRY AND SEASONAL CONDITIONS SUNDAY AND MONDAY. THEREAFTER...FORECAST CONFIDENCE DROPS QUICKLY AS DIFFERING MODEL SOLUTIONS PROVIDE NO CLEAR PICTURE FOR THE END OF THE LONG TERM. THE FORECAST WAS THUS BASED ON PERSISTENCE WITH ONLY MINOR CHANGES TO TUESDAY AND WEDNESDAY. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... HIGH PRESSURE WILL MAINTAIN VFR WITH EXCEPTIONS OF BRIEF DAWN FOG. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY... THE NEXT CHANCE FOR GENERAL RESTRICTIONS WILL COME WITH A LATE SATURDAY COLD FRONT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
325 PM EDT THU SEP 17 2015 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/MARINE .SYNOPSIS... ISSUED AT 320 PM EDT THU SEP 17 2015 MULTIPLE ROUNDS OF SHOWERS AND THUNDERSTORMS WILL MOVE THROUGH THE REGION...STARTING AS EARLY AS THIS EVENING AND CONTINUING OVERNIGHT. ANOTHER ROUND OF STORMS LOOKS LIKELY FRIDAY NIGHT INTO SATURDAY MORNING WITH SOME HEAVY RAINS EXPECTED. SOME FLOODING COULD OCCUR WHERE STORMS PERSIST. COOLER AND BREEZY CONDITIONS MOVE IN SATURDAY BEFORE A WARMING TREND STARTS AGAIN. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 320 PM EDT THU SEP 17 2015 THE TWO PRIMARY RISKS TO EVALUATE THROUGH SATURDAY MORNING WILL BE DAMAGING WIND GUST POTENTIAL ALONG WITH LOCALIZED FLOODING. FOR THIS EVENING...ALMOST ALL NUMERICAL GUIDANCE IS STRUGGLING WITH THE CONVECTION ACROSS NORTHERN IL. ONLY THE HRRR HAS A CLUE ABOUT CONVECTIVE TRENDS AT THIS POINT AND SUGGESTS THE RAIN WILL PROCEED ACROSS THE LAKE THIS EVENING AND WEAKEN A BIT...IN SPITE OF SPC SREF-BASED EFFECTIVE BULK SHEAR INCREASING OVER THE LAKE (THOUGH CIN WILL BE GROWING TOWARD NIGHTFALL). BUMPED POPS UP THIS EVENING ESPECIALLY NEAR/WEST OF US 131 TO INCLUDE THIS THREAT FOR STORMS IN CASE THEY SURVIVE THE TRIP OVER THE LAKE. NOT EXPECTING ANY SEVERE WEATHER WITH THIS. LATER TONIGHT...LOOKS LIKE A LINE OF STORMS WILL SOLIDIFY ACROSS EASTERN WI IN THE MIDST OF A MID LEVEL SHORTWAVE APPROACHING BY 06Z AND A 40 KT LLJ ADVECTING MOISTURE INTO THE REGION. THIS LINE FORMS ALONG A WEAK COLD FRONT WHICH WILL SLOW DOWN AND STALL OUT OVER THE HEART OF THE CWA FRIDAY. RAIN CHANCES LOOK QUITE LIKELY OVERNIGHT THOUGH INSTABILITY LOOKS WEAK OR NONEXISTENT FOR MOST PLACES. WITH ONLY MODEST WINDS ACROSS THE COLUMN...WOULD EXPECT LITTLE OR NO SEVERE WEATHER WITH THIS ACTIVITY OVERNIGHT. THE BIGGER THREAT WOULD BE LOCALLY HEAVY DOWNPOURS...MAYBE UP TO AN INCH IN SPOTS. AREAS THAT GET THE HEAVIEST RAIN WOULD BE FAVORED FOR A FLOOD THREAT FRIDAY NIGHT GIVEN MOIST SOILS AND HENCE SOME FAVORABLE ANTECEDENT CONDITIONS. THE SEVERE WEATHER THREAT DOES GO UP FRIDAY...ESPECIALLY IN THE EVENING AND LASTING THROUGH THE NIGHT. DAMAGING WIND GUSTS AND SOME FLOODING ARE BOTH POTENTIAL HAZARDS. THE SFC COLD FRONT WILL STALL OVER THE REGION FRIDAY AND BECOME A WARM FRONT BY EVENING. WITH AN INCREASING LLJ TO 50 KTS...THERE WILL BE VERY GOOD MOISTURE CONVERGENCE SETTING UP ALONG THIS FRONT...LEADING TO SOME HEAVY RAINS. UPPER LEVEL DIVERGENCE WILL BE INCREASING BY 00Z FRIDAY...AND WITH THE RIGHT ENTRANCE REGION OF THE JET APPROACHING THE DEEP LAYER SHEAR WILL INCREASE...ESPECIALLY ACROSS CENTRAL LOWER MI. EVEN THE STRONG LLJ ALONE WOULD SUGGEST SOME DAMAGING WIND POTENTIAL. GIVEN THE WARM FRONT NEARBY...A BOOST TO THE 0-1 KM STORM RELATIVE HELICITY CAN BE EXPECTED...AND THE ECMWF SHOWS THIS NICELY WITH VALUES APPROACHING 200-250 M2/S2 BETWEEN 00Z-06Z SAT. GIVEN RELATIVELY LOW CAPE...THE SEVERE WEATHER POTENTIAL WILL NOT BE AS HIGH AS IT COULD BE. EVEN SO...INCREASING DEEP LAYER SHEAR MAY HELP OFFSET THIS AND STILL SUPPORT SOME STRONG TO SEVERE THUNDERSTORMS. OUR MODEL BLENDED QPF FEATURES 1"-2" THROUGH SATURDAY. HOWEVER... LOCALIZED HEAVY RAINFALL RATES OF 1"/HR OR MORE ARE QUITE POSSIBLE GIVEN THE NATURE OF THIS SYSTEM (HIGH PW VALUES FOR MID SEPTEMBER AND DEW POINTS CLIMBING INTO THE UPPER 60S). SOME PONDING ON ROADS IS POSSIBLE OVERNIGHT AND MAYBE FOR THE MORNING COMMUTE. FLOODING OF ROADS IN A SHORT TIME IS A THREAT FRIDAY/FRIDAY NIGHT WHERE HEAVIER STORMS SET UP. THIS THREAT COULD BE A GREATER HAZARD TO MOTORISTS AND IT MAY LINGER INTO SATURDAY MORNING. && .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 320 PM EDT THU SEP 17 2015 I THINK WE WILL NEED TO WATCH THIS FORECAST CLOSELY IN THE COMING DAYS. WILL MAINTAIN THE DRY PERIOD FOR NOW. THE MAIN CONCERN IS THAT MODELS ARE IN DECENT AGREEMENT IN KEEPING AN UPPER TROUGH OVERHEAD. THIS MAY SUPPORT SOME INSTABILITY TYPE SHOWERS. AT THE SURFACE HIGH PRESSURE IS IN PLACE. SUBSIDENCE WITH THIS FEATURE SHOULD LIMIT THE SHOWER/STORM RISK. SLOW MODERATION OF THE TEMPERATURES IS FORECASTED BECAUSE THE LOW LEVEL THERMAL TROUGH GENERALLY STAYS IN PLACE. TEMPERATURES ARE LIKELY TO END UP FAIRLY CLOSE TO SEASONABLE. THE WARMEST DAYS WILL LIKELY BE BE THURSDAY AS A LOW LEVEL THERMAL RIDGE TRIES TO SET UP OVER THE REGION. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 142 PM EDT THU SEP 17 2015 A BAND OF SHOWERS AND THUNDERSTORMS WILL TRACK THROUGH THE TAF SITES OVERNIGHT FROM WEST TO EAST. THEY SHOULD REACH KMKG ROUGHLY AROUND MIDNIGHT. IMPACTS ARE EXPECTED WITH AT LEAST MVFR AT ALL SITES...ALTHOUGH A BRIEF PERIOD OF IFR COULD OCCUR. THE STORMS SHOULD PUSH EAST OF KJXN BY 14Z FRI. WITH A VERY MOIST AIRMASS IN PLACE...MVFR FOG SHOULD LINGER THROUGH THE MORNING. && .MARINE... ISSUED AT 320 PM EDT THU SEP 17 2015 && .HYDROLOGY... ISSUED AT 206 PM EDT THU SEP 17 2015 RAIN OF ONE TO TWO INCHES EXPECTED TONIGHT INTO SATURDAY MORNING... AHEAD OF AND WITH A FRONTAL BOUNDARY EXPECTED TO STALL OVER THE AREA. NO FLOODING ISSUES ARE EXPECTED THROUGH FRIDAY. LEVELS ARE FALLING OR STEADY ON ALL AREA RIVERS. LOCALLY OVER 2 INCHES OF RAIN ARE POSSIBLE AND MAY LEAD TO PONDING OF WATER IN SOUTHWEST LOWER MICHIGAN FRIDAY INTO THE WEEKEND. ISOLATED AREAS MAY ALSO SEE SOME STREET AND SMALL STREAM FLOODING. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...BEACH HAZARDS STATEMENT THROUGH FRIDAY MORNING FOR MIZ037-043- 050-056. LM...GALE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY AFTERNOON FOR LMZ844>849. SMALL CRAFT ADVISORY UNTIL 7 AM EDT FRIDAY FOR LMZ846>849. && $$ SYNOPSIS...HOVING SHORT TERM...HOVING LONG TERM...MJS AVIATION...MJS HYDROLOGY...63 MARINE...HOVING
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
232 AM EDT THU SEP 17 2015 .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 306 PM EDT WED SEP 16 2015 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOWS THE UPPER GREAT LAKES REGION BEING LOCATED BETWEEN AN UPPER RIDGE OVER THE EASTERN CONUS AND AN UPPER TROUGH OVER THE WESTERN CONUS. THIS HAS LED TO SOUTHWESTERLY FLOW ACROSS THE UPPER GREAT LAKES REGION AND THERE WAS A WEAK SHORTWAVE THAT LIFTED NORTHEAST ACROSS THE AREA THIS MORNING. THIS LED TO CLOUDS/SHOWERS AND EVEN A FEW THUNDERSTORMS OVER THE WESTERN U.P. UNDER THE STEEP 700-300MB LAPSE RATES. THIS WAVE HAS LIFTED TO THE NORTHEAST AND BROUGHT MUCH OF THE MID CLOUDS WITH IT...ALTHOUGH THERE ARE STILL SOME LINGERING SHOWERS/SPRINKLES OVER THE EAST AND NEAR DULUTH. THE THICKER MID CLOUDS DID HOLD OFF TEMPS AND WINDS SOME THIS AFTERNOON BUT NOT THAT WE ARE SEEING MORE BREAKS OVER THE WESTERN HALF OF THE CWA...TEMPERATURES HAVE RISEN INTO THE UPPER 70S AND LOWER 80S. AS OF 3PM...NWS MARQUETTE IS JUST BELOW OUR RECORD HIGH FOR TODAY (79) AND WOULD EXPECT THAT TO BE BROKEN IN THE NEXT HOUR OR TWO. THE CLOUDS DID HELP LIMIT MIXING FROM REACHING THE STRONGER WINDS ALOFT...BUT HAVE STILL BEEN SEEING 15-25KT WINDS OVER MUCH OF THE AREA. EXPECT THE INCREASED SUNSHINE OVER THE NEXT COUPLE HOURS TO LEAD TO SLIGHTLY HIGHER GUSTS THROUGH EARLY EVENING. THE SURFACE LOW THAT IS CURRENTLY IN NORTHERN ONTARIO WILL CONTINUE NORTHEAST THIS EVENING AND OVER NORTHERN JAMES BAY. THEN...ANOTHER WAVE EJECTING NORTHEAST ACROSS EASTERN IDAHO WILL LEAD TO A STRENGTHENING SURFACE LOW THAT IS CURRENTLY IN NORTHEAST WYOMING. THIS LOW WILL LIFT NORTHEAST ACROSS THE DAKOTAS TONIGHT AND THEN INTO NORTHERN ONTARIO ON THURSDAY. EXPECT PRECIPITATION CHANCES TONIGHT INTO THURSDAY MORNING TO BE SIMILAR TO LAST NIGHT INTO THIS MORNING WHERE THERE ARE STEEP 750-400MB LAPSE RATES IN PLACE AND POCKETS OF MOISTURE OVER WESTERN LAKE SUPERIOR INTO FAR WESTERN UPPER MICHIGAN. IN ADDITION...THERE IS A WEAK SHORTWAVE IN WESTERN IOWA THAT LOOKS TO LIFT NORTHEAST THROUGH THE AREA. WITH THOSE FEATURES BRUSHING THE WESTERN HALF OF THE CWA...WILL CONTINUE TO SHOW SLIGHT CHANCE TO LOW END CHANCES FROM EAST TO WEST TOWARDS THE MINNESOTA ARROWHEAD. WHILE THE DRY AIR BELOW 700MB WILL LIKELY LIMIT THE MEASURABLE PRECIP IN SOME AREAS...FEEL THE SUPPORT IS THERE FOR MEASURABLE RAIN TO OCCUR. ONCE AGAIN...EXPECT WINDS TO STAY UP ACROSS THE AREA THROUGH THE NIGHT WITH THE STRONG LOW LEVEL JET (TO 45KTS) 2-3KFT ABOVE THE SURFACE. THOSE GUSTY WINDS WILL ALSO KEEP TEMPERATURES WELL ABOVE THE NORMAL LOWS AND IN THE 60S WITH A FEW 70S OVER THE DOWNSLOPING AREAS OUT WEST. HEADING INTO TOMORROW AFTERNOON...THE COLD FRONT TRAILING THE SURFACE LOW LIFTING NORTHEAST FROM THE DAKOTAS INTO NORTHERN ONTARIO THROUGH THE DAY WILL BE MOVING INTO WESTERN LAKE SUPERIOR DURING THE LATE AFTERNOON AND EVENING HOURS. BELIEVE THE SHOWERS/THUNDERSTORMS WILL BE LARGELY FOCUSED ALONG THE FRONT. BUT THERE ARE SOME HINTS AT DEVELOPMENT OUT AHEAD OF THE FRONT AND TIED TO A SHORTWAVE LIFTING NORTHEAST ACROSS THE WESTERN U.P. DURING THE AFTERNOON HOURS. INSTABILITY WILL INCREASE OVER THE AREA WITH 1000-1500 J/KG OF MLCAPE. BEST 0-6KM BULK SHEAR IS CONFINED TO THE AREAS IN IMMEDIATE PROXIMITY OF THE FRONT...WITH THE REST OF THE AREA 20-25KT OUT AHEAD OF THE FRONT. THAT WILL LEAD TO THE STRONGEST STORMS OCCURRING TO THE WEST OF THE AREA IN THE AFTERNOON AND THEN TRYING TO SHIFT EAST INTO THE U.P. DURING THE EVENING. WITH MORE CLOUD COVER TOMORROW...HAVE LIMITED THE TEMPS TO THE UPPER 70S WITH A FEW LOWER 80S IN THE DOWNSLOPE AREAS NEAR LAKE SUPERIOR. WIND GUSTS WILL ALSO BE SIMILAR BUT SLIGHTLY LOWER AND ONCE AGAIN HAVE GUSTS IN THE 20- 25KT RANGE. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 351 PM EDT WED SEP 16 2015 MAIN FCST CONCERNS IN THE LONGER TERM WL BE FOCUSED ON POPS/SEVERE WX POTENTIAL THU NGT ASSOCIATED WITH COLD FROPA THAT WL BRING A RETURN OF COOLER WX LATE THIS WEEK. ANOTHER CONCERN WL BE POPS LATE FRI INTO SAT RELATED TO THE APRCH OF ANOTHER SHRTWV AND ITS INTERACTION WITH STALLING FNT IN THE CENTRAL GREAT LKS. HI PRES AND NEAR SEASONABLE TEMPS WL THEN DOMINATE LATE THIS WEEKEND. THU NGT INTO FRI...LATEST MODEL GUIDANCE IS IN GOOD AGREEMENT SHOWING SFC COLD FNT CROSSING THE UPR LKS THU NGT PASSING NEWBERRY SOON AFTER 12Z FRI AND INTERACTING WITH WARM AIRMASS/PWAT NEAR 1.75 INCHES. SINCE NAM/GFS SDNGS INDICATE THE PRE FRONTAL AIRMASS WL BE CAPPED...THE BULK OF SHOWERS/TS THAT FORM UNDER H7-5 LAPSE RATES AS STEEP AS 7.5-8C/KM ARE LIKELY TO BE CLOSER TO THE SFC FNT. FCST MUCAPES AS HI AS 1000-1500 J/KG...DEEP LYR SHEAR ABOUT 30-35KTS ALONG THE FRONTAL BNDRY AND FCST DCAPES AS HI AS ABOUT 1000 J/KG FOLLOWING THE WARM DAY ON THU SUPPORT THE MARGINAL/SLGT RISK FOR SVR STORMS OUTLOOK FM SPC. RELATIVELY HI FRZG LVL FCST IN THE 12-14K RANGE AND DEEP SATURATION SHOWN ON ESPECIALLY THE NAM FCST SDNGS AS WELL AS PASSAGE OF STRONGER SHRTWV/HGT FALLS FARTHER TO THE N CLOSER TO THE MAIN SHRTWV TRACK IN FAR NW ONTARIO ARE NEGATIVES. BEST CHC FOR THE STRONGER STORMS SHOULD BE OVER THE W...WHERE THE ARRIVAL OF THE FNT IN THE EVNG WOULD BE MORE IN SYNC WITH THE DAYTIME HEATING CYCLE/HIER DCAPES. THE ARRIVAL OF DRIER/COOLER AIR BEHIND THE FROPA WL BRING A DRYING TREND W-E LATER THU NGT INTO FRI...BUT SHALLOW LLVL MSTR WITH INFLUX OF COOLER AIR BEHIND THE FNT/LO INVRN MAY LEAD TO LINGERING LO CLDS INTO FRI MRNG...ESPECIALLY IN THE UPSLOPE AREAS NEAR LK SUP. FRI/SAT...ARRIVAL OF DRIER AIR/WEAK HI PRES RDG AND LLVL ACYC FLOW WL RESULT IN A PERIOD OF DRY WX ON FRI AFTER LINGERING SHOWERS END IN THE MRNG OVER THE E. BUT APRCH OF SHRTWV FM THE W IN MORE ZONAL FLOW IN THE NRN PLAINS IS FCST TO CAUSE A SFC LO PRES TO DVLP ON FRI AFTN IN IOWA ALONG STALLING COLD FNT STRETCHING FM THAT STATE INTO LOWER MI UNDER MORE SW FLOW ALF ON NW FLANK OF UPR RDG PERSISTING IN THE ERN CONUS. SOME OF THE MEDIUM RANGE GUIDANCE HAD INDICATED A BAND OF PCPN ASSOCIATED WITH AXIS OF MID LVL FGEN WOULD IMPACT AT LEAST PORTIONS OF THE CWA ON FRI AFTN WELL TO THE NE OF THIS FEATURE...BUT DRYNESS OF THE MID LVL AIRMASS SHOWN ON THE 12Z NAM/ GFS FCST SDNGS SUG A DRY FCST IS WARRANTED AFTER THE FROPA SHOWERS END OVER THE E IN THE MRNG. THERE ARE CONSIDERABLE MODEL DIFFERENCES ON HOW QUICKLY AND TO WHAT EXTENT THE SFC LO IN IOWA WL INTENSIFY AS IT TRACKS NE ON THE STALLED FNT INTO THE CENTRAL LKS. THE 12Z NAM IS DEEPEST AND FARTHER W WITH THE TRACK OF THIS SYSTEM...SHOWING WIDESPREAD RA IMPACTING ALL OF UPR MI THRU THE DAY ON SAT WITH FAIRLY SHARP CYC NE FLOW LEADING TO A VERY CHILLY DAY AS WELL. THE 00Z CNDN/ECMWF RUNS ON THE OTHER HAND SHOWED A RELATIVELY WEAK SFC LO MOVING QUICKLY TO THE NE...WITH LIGHTER PCPN ENDING SOON AFTER 12Z SAT. ALTHOUGH THE INCOMING SHRTWV IS RATHER IMPRESSIVE...WITH 00Z-12Z SAT H5 HGT FALLS FCST UP TO 100M EVEN WITH THE WEAKER ECWMF FCST...AND MODEL TRENDS SUPPORT THE NAM FCST...PREFER TO FOLLOW A COMPROMISE BTWN THE SOMEWHAT DEEPER 12Z GFS/CNDN/ECMWF MODEL FCSTS AND THE WEAKER/FASTER SCENARIO SHOWN BY THE 00Z ECMWF/CNDN AND 09Z SREF. NCEP GUIDANCE ALSO INDICATES A PREFERENCE FOR REJECTING THE DEEPER 12Z NAM FCST. THE PREFERRED MODELS SHOW THE HIER CATEGORICAL/ LIKELY POPS OVER ALL BUT THE WRN CWA...WHERE CHC POPS APPEAR MORE APPROPRIATE FARTHEST FM THE STALLED BNDRY TO THE SE. THIS SCENARIO WL ALSO SUPPORT A STEADY DRYING TREND W-E ON SAT...WITH PCPN ENDING OVER THE FAR E BY EARLY/MID AFTN. SAT NGT INTO TUE...HI PRES TRAILING THE DEPARTING SFC LO PRES IS FCST TO BUILD INTO THE LOWER GREAT LKS BY 12Z SUN...THE NE STATES AT 12Z MON AND THEN OVER THE CNDN MARITIMES ON TUE. DRY ACYC SW FLOW ARND THIS FEATURE WL DOMINATE UPR MI DURING THIS TIME AND BRING A PERIOD OF DRY WX. ALTHOUGH PWAT FALLING TOWARD 0.5 INCH AT 12Z SUN WOULD SUPPORT SOME CHILLY OVERNGT LOWS...STEADY WSW FLOW ON THE NRN FLANK OF HI PRES CENTER TO THE S MAY TEND TO LIMIT THE POTENTIAL FOR COLDER TEMPS/FROST...ESPECIALLY OVER THE NW HALF UNDER TIGHTER PRES GRADIENT. H85 TEMPS ARE FCST TO SLOWLY MODERATE THRU THIS TIME... RISING FM ARND 8C ON SUN TO ARND 10C ON MON AND THEN 12C ON TUE... SUPPORTING A SLOW WARMING TREND THAT WL FEATURE MEAN DAILY TEMPS RISING FM NEAR NORMAL ON SUN TO AT LEAST A BIT ABOVE NORMAL AGAIN ON MON/TUE. TUE/WED...SHRTWV MOVING THRU ZONAL FLOW OVER CENTRAL CANADA IS FCST TO DRAG A COLD FNT THRU THE UPR LKS LATE TUE/TUE NGT. SINCE THERE ARE TIMING DIFFERENCES AND THE LONGER RANGE GUIDANCE HINTS MSTR INFLOW WL BE SOMEWHAT LIMITED TO THE S OF SHARPER HGT FALLS TO THE N...NO MORE THAN LO CHC POPS ARE NECESSARY AT THIS POINT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 231 AM EDT THU SEP 17 2015 VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH GUSTY SOUTH-SOUTHWESTERLY WINDS. THE GUSTY WINDS WILL WEAKEN SLIGHTLY OVERNIGHT AND LEAD TO THE POTENTIAL FOR LLWS AT ALL THREE SITES. THOUGH KIWD WOULD HAVE THE BEST CHANCE FOR THE WINDS TO STAY UP AND HAVE LEFT LLWS OUT OF IWD...BUT CMX AND SAW WILL HAVE THEM OVERNIGHT. A DISTURBANCE WILL PUSH ACROSS WESTERN LAKE SUPERIOR LATE TONIGHT AND IT COULD BRUSH KIWD. THEN...SHOWERS WILL INCREASE FROM WEST TO EAST DURING THE AFTERNOON AND EVENING AS A COLD FRONT SWEEPS ACROSS THE AREA. EXPECT DETERIORATING CONDITIONS TO MVFR CIGS FOR ALL SITES LATE IN THE AFTERNOON AND MVFR CIGS WILL BE CLOSE TO CMX AT THAT TIME AS WELL. THE MVFR CONDITIONS WILL LAST INTO FRI EVENING AT ALL SITES. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 306 PM EDT WED SEP 16 2015 GUSTY SOUTHERLY WINDS WILL REMAIN IN PLACE OVER THE NEXT 24-30 HOURS AS THE UPPER GREAT LAKES REGION IS BETWEEN HIGH PRESSURE IN THE MID ATLANTIC STATES AND A COUPLE LOWS THAT WILL BE MOVING NORTHEAST ACROSS ONTARIO. THESE SOUTHERLY WINDS WILL GENERALLY BE IN THE 15-25KT RANGE...BUT WITH VERY STRONG WINDS JUST ABOVE THE SURFACE...COULD SEE SOME STRONGER GUSTS TO 30KTS AT TIMES OVER EASTERN LAKE SUPERIOR. A COLD FRONT MOVING EAST ACROSS LAKE SUPERIOR ON THURSDAY NIGHT WILL SHIFT WINDS TO THE NORTHWEST UP TO 25KTS. THE WINDS WILL DIMINISH THROUGH THE DAY ON FRIDAY AS A HIGH PRESSURE RIDGE QUICKLY BUILDS INTO THE AREA. ON FRIDAY NIGHT...A SURFACE LOW WILL DEVELOP ALONG THE COLD FRONT THAT MOVED THROUGH ON THURSDAY NIGHT AND MOVE THROUGH LOWER MICHIGAN. THIS WILL SHIFT WINDS MORE OUT OF THE NORTHERLY DIRECTION UP TO 25 KNOTS LATE FRIDAY NIGHT INTO SATURDAY MORNING. A LARGE HIGH PRESSURE RIDGE WILL BUILD OVER THE GREAT LAKES REGION SATURDAY NIGHT AND REMAIN INTO MONDAY AND KEEP WINDS BELOW 20KTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...SRF LONG TERM...KC AVIATION...07 MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
644 AM CDT THU SEP 17 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 515 AM CDT THU SEP 17 2015 A VERY SUMMER FEEL TO THE WEATHER THIS MORNING...WITH 3 AM TEMPERATURES ACROSS MUCH OF THE AREA STILL IN THE LOW TO MID 70S...DEWPOINTS IN THE UPPER 60S...AND HIT-AND-MISS THUNDERSTORMS POPPING UP ALL NIGHT WITHIN A MOISTURE RICH 30 KT LLJ. RESPONSIBLE FOR ALL OF THIS IS A BROAD TROUGH OVER WRN CANADA WITH ITS AXIS DIPPING DOWN INTO NEVADA. THIS UPPER FEATURE WILL LIFT NE THROUGH THE DAY...WHICH WILL HELP DRIVE THE SFC LOW OVER SE NODAK INTO NW ONTARIO...FINALLY DRIVING THE COLD FRONT THAT HAS THREATENED TO COME INTO THE MPX AREA THE LAST FEW DAYS THROUGH MN AND WI. BIGGEST CHANGE NOTED WITH THE GUIDANCE...ESPECIALLY WITH RESPECT TO THE CAMS...IS A SLOWING IN THE SPEED WITH WHICH THE FRONT MOVES ACROSS THE AREA...SO BIGGEST CHANGE WITH THE FORECAST WAS TO PULL CATEGORICAL POPS THIS AFTERNOON FARTHER WEST AND SLOW THEIR DEPARTURE OUT OF THE ERN SECTIONS OF THE MPX CWA. FOR THIS MORNING...MOST HI-RES GUIDANCES SHOW GREATEST TSRA COVERAGE OCCURRING THIS MORNING OVER ERN MN/WRN WI AS A WAVE CURRENTLY DOWN BY SIOUX CITY LIFTS NORTHEAST TOWARD WRN WI. THIS ACTIVITY SHOULD LARGELY CLEAR THE MPX AREA BY NOON...WITH THE EVER SO BRIEF BREAK IN TSRA ACTIVITY OCCURRING BEFORE STORMS LIGHT UP ALONG THE COLD FRONT IN THE AFTERNOON. PRETTY GOOD AGREEMENT AMONG THE CAMS THAT WE SEE DEEP CONVECTION INITIATE ALONG THE COLD FRONT BETWEEN 19Z AND 21Z NEAR A CAMBRIDGE TO MANKATO LINE. FORCING AND MORE LINE PARALLEL SHEAR SUPPORT WHAT THE CAMS SHOW IN THAT WE SEE A BROKEN LINE OF STORMS DEVELOP THAT SWEEPS EAST INTO WI AROUND 21/22Z AND QUICKLY CLEARS THE ERN SECTIONS OF THE MPX AREA AROUND 2Z. FROM THE SEVERE POTENTIAL...WE CONTINUE TO SEE MIXED SIGNALS. MODELS ARE PRETTY CONSISTENT WITH DEVELOPING 1500-2500 J/KG OF MLCAPE AHEAD OF THE FRONT THIS AFTERNOON THAT IS RELATIVELY UNCAPPED AS CONTINUED HEIGHT FALLS START TO COOL THE WARM EML THAT MOVED OVER US ON SUNDAY. PROBLEM WITH THIS THOUGH IS THIS EML IS WHAT HAS GIVEN US VERY STEEP MID LEVEL LAPSE RATES...AND THOSE WILL BE WEAKENING WITH THE CAP. IN ADDITION...THERE WILL STILL BE A DISCONNECT BETWEEN THE DEEP LAYER SHEAR AND THE LOW LEVEL SHEAR. THE DEEP SHEAR WILL BE LAGGING BEHIND THE FRONT SOME...WITH THE LOW LEVEL SHEAR PUSHING EAST WITH THE LLJ THIS EVENING. LOOKING AT CAMS...PROBABILITIES FOR UH GREATER THAN 25 M/S IS GREATEST AROUND SE MN/NE IA/SW WI...WHICH IS WHERE THE GREATEST DESTABILIZATION IS EXPECTED AND HAPPENS TO COINCIDE WITH WHERE THE SPC HAS A 5% TORNADO THREAT. WITH QUESTIONS ABOUT AMOUNT OF CLEARING AND DESTABILIZATION WE SEE ALONG WITH THE WEAKER MID LEVEL LAPSE RATES...WE MAY NOT SEE QUITE AS ROBUST UPDRAFTS AS WE HAVE MANAGED THIS MORNING...BUT THE SEVERE RISK SEEMS WARRANTED...WITH THE CIPS SEVERE ANALOGS CONTINUING TO SHOW 4 OF THE 15 ANALOG EVENTS THAT PRODUCED SLIGHT RISK OR GREATER WORTHY SEVERE REPORTS. FOR TONIGHT...WE WILL QUIET DOWN PRETTY QUICK IN THE WAKE OF THE FRONT...WITH DEWPOINTS FALLING BACK INTO THE 40S...THOUGH WE LOOK TO ONLY HAVE ENOUGH TIME TO GET TEMPS DOWN INTO THE 50S BEFORE DIURNAL WARMING KICKS IN FRIDAY MORNING. ANY RAIN COMING IN WITH THE SYSTEM FOR FRIDAY WILL COME AFTER 12Z FRIDAY...SO HAVE THE REST OF THE SHORT TERM DRY ONCE WE CLEAR THE COLD FRONT OUT. .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ISSUED AT 415 AM CDT THU SEP 17 2015 FRIDAY AND FRIDAY NIGHT...POTENT CDFNT WILL BE LOCATED OVER LK MICHIGAN SNAKING SWWD OVER SRN WI INTO NE IA...WELL E OF THE WFO MPX CWFA. THIS WILL ALLOW MUCH COOLER AIR TO INFILTRATE THE REGION AS HIGH TEMPS WILL ONLY HIT THE LOW-MID 60S FRI AFTN. A SECONDARY WEAK LOW PRES CENTER WILL DEVELOP OVER THE WRN DAKOTAS DURG THE DAY ON FRI...IN ADVANCE OF A KICKER SHTWV H5 TROF MOVG EWD WITHIN FAIRLY PROGRESSIVE ZONAL FLOW ALOFT. A SWATH OF MID-UPR LVL MOISTURE WILL ACCOMPANY THE SFC LOW BUT DRIER AIR AT THE SFC WILL MITIGATE HIGH QPF AMOUNTS ALONG WITH THE PROGRESSIVE NATURE OF THIS SYSTEM. PLUS...INSTABILITY WILL BE AT A MINIMUM SO WILL OMIT THUNDER FROM THIS PORTION OF THE FCST. COVERAGE LOOKS TO ONLY BE SCATTERED SO 30-50 POPS WILL GENERALLY SUFFICE...ALTHOUGH THE TRACK OF THE SYSTEM FROM THE SRN DAKOTAS OVER SRN MN DOES WARRANT SOME LIKELY POPS NEAR THE IA BORDER. THIS SYSTEM QUICKLY SHIFTS INTO WI FRI NIGHT...ALLOWING ANY AND ALL PRECIP TO COME TO AN END BY DAYBREAK SAT MRNG. SATURDAY THROUGH MONDAY...HIGH PRES WILL MAKE ITS WAY INTO THE REGION OVER THE WEEKEND THROUGH MONDAY OF NEXT WEEK. MAINLY CLEAR SKIES AND DRIER AIR WILL BE THE RULE. IN ADDITION...SFC WINDS WILL GRADUALLY SWING AROUND FROM NWLY ON SAT TO SLY ON SUN AND MON WHILE A NE-SW RIDGE AXIS ALOFT SHIFTS OVER THE REGION. THE SFC SHIFT PLUS BUILDING HEIGHTS ALOFT THROUGH THIS PERIOD WILL MEAN A GRADUAL WARMING OF TEMPERATURES INTO EARLY NEXT WEEK. HIGHS WILL CLIMB OUT OF THE 60S INTO THE LWR-MID 70S. TUESDAY AND WEDNESDAY...ANOTHER COLD FRONT IS PROGGED TO PUSH THRU THE REGION DURING THE MIDDLE OF NEXT WEEK ALTHOUGH THE TIMING AND PHASING WITH MOISTURE IS A BIT IN QUESTION BETWEEN THE 00Z GFS AND 00Z ECMWF. THERE IS COMMONALITY BETWEEN A FRONTAL PASSAGE SO HAVE OPTED TO INCLUDE POPS BUT NO HIGHER THAN 30 PERCENT FOR EITHER PERIOD. HAVE ALSO SHOWN A SLIGHT DROP IN TEMPS DUE TO THE CLOUD/RAIN COMPLICATIONS AND THE FROPA...KNOCKING HIGHS BACK DOWN TO THE UPR 60S TO ARND 70. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 644 AM CDT THU SEP 17 2015 NUMEROUS THUNDERSTORMS WILL BE IMPACTING ERN MN/WRN WI THIS MORNING. INHERITED TAFS CAPTURED THIS THREAT WELL AND ALL THAT WAS NEEDED WAS TO EXTEND TEMPO GROUPS BY ABOUT AN HOUR AS STORMS CONTINUE TO BUILD TO THE SW. WITH THE MULTIPLE ROUNDS OF RAIN...MVFR CIGS HAVE STARTED TO APPEAR AS WELL...SO LEFT MVFR CIG MENTION IN AS WELL FOR MSP/RNH/EAU...THOUGH THEY MAY NOT LAST AS LONG AS CURRENTLY FORECAST...ESPECIALLY IN WI. HRRR IS STARTING TO BACK OFF SOME ON ITS THUNDERSTORM DEVELOPMENT ALONG THE FRONT THIS AFTERNOON...THOUGH STARTING TO GET MORE CONFIDENT ON POTENTIAL TIMING OF STORMS WITH THE FRONT...SO NARROWED DOWN AFTERNOON TEMPOS AT MSP/RNH/EAU. AFTERNOON ACTIVITY WILL REMAIN EAST OF AXN/STC/RWF. BEHIND THE FRONT TONIGHT...HIGH CONFIDENCE IN WINDS GOING NORTHWEST AND SKIES SKC. KMSP...14Z MAY BE A LITTLE LONG FOR CARRYING A TEMPO GROUP FOR THUNDER THIS MORNING...BUT WITH ACTIVITY CONTINUING TO DEVELOP SW OF THE FIELD...DECIDED TO ERR ON THE SIDE OF CAUTION WITH STORMS THIS MORNING. HRRR IS STARTING TO BACK AWAY FROM STORMS IMPACTING MSP THIS AFTERNOON AND BASED NARROWER WINDOW FOR AFTERNOON TEMPO GROUP ON WHEN MODELS SHOW FRONT WORKING INTO THE TWIN CITIES. /OUTLOOK FOR KMSP/ FRI...VFR. MVFR SHRA POSSIBLE. WIND NNW 5-10 KTS. SAT...VFR. WIND W 7-10 KTS. SUN...VFR. WIND S 10-12 KTS. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SHORT TERM...MPG LONG TERM...JPC AVIATION...MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1057 PM CDT FRI SEP 18 2015 .SHORT TERM...(This Evening through Sunday Night) Issued at 311 PM CDT FRI SEP 18 2015 Complicated forecast shaping up for the remainder of this afternoon and evening as long advertised front slowly works through the area. At 3 PM...regional radars showed a clearly defined fine line slowly working south through northwest Missouri and northeast Kansas...indicative of the current position of the boundary in question. As expected...sfc low across east-central Kansas continues to slowly lift northeastward along the boundary...with plenty of pre- frontal precipitation prevailing over the fcst region this afternoon. Looking aloft...afternoon water vapor imagery showing a nicely defined neutrally tilted trough axis digging through the Central Plains...with a mid-level jetstreak extending from east-central Colorado northeastward into south-central Nebraska. Forcing for ascent will continue to increase through the late afternoon/early evening as aforementioned wave approaches...but morning and early afternoon convection has certainly thrown a monkey wrench into today/s forecast. Latest visible satellite images finally showing some clearing in advance of the boundary this afternoon...and latest MLCAPE estimates from the SPC meso page are responding accordingly. Quick look at the GOES 7.4 micron channel shows leading edge of a secondary EML plume advancing east through west-central Kansas this afternoon...with new convection beginning to develop southwest of Topeka right ahead of the front. In the time its taken to write this much of the AFD...we/ve gone from little hope for severe to renewed optimism that things may in fact get going. That said...latest HRRR appears to be taking into account the partial clearing with decreased surface inhibition and now shows convection working through the KC Metro during the evening rush hour. As a result...all hope does is not lost as of right now anyways. If convection can in fact become organized /and there/s plenty of deep layer shear to support this/ large hail and damaging winds will be possible...especially if surface based inhibition erodes accordingly. Additionally...bulk shear vector orientation normal to the linear line of forcing will support supercell structures with eventual progression into linear segments as convection is able to congeal after sunset. Again...this scenario is only of marginal confidence at this point...and the next few hours will be telling on what is actually able to get organized...if anything. Additionally...concerns for heavy rainfall continue this afternoon as an axis of anomalously high PWAT values (> 1.7") remains entrenched across the fcst area. Combine this with the most recent images from the experimental layered PW satellite product from Colorado State which shows converging subtropical and northern stream moisture plumes over the Lwr Missouri Vly...organized rainfall should have little problem producing heavy rainfall rates across the area. Considering the amount of uncertainty with the going forecast this afternoon...will go ahead and leave the current flash flood watch in place until clearing begins to occur from west to east later tonight. Front to plow through the region overnight with precip quickly coming to an end after 6z or so. Dry air will quickly move in by Saturday morning as high pressure builds south across the Central Plains/upper Miss Rvr Vly. As cold air infiltrates the area...afternoon highs tomorrow afternoon will struggle to make it out of the upper 60s. Slightly warmer temps are expected on Sunday...with highs likely warming into the lower to middle 70s across most locations. Warming trend will commence early next week as southerly flow returns to the area. .LONG TERM...(Tuesday through Friday) Issued at 311 PM CDT FRI SEP 18 2015 Upper-level ridging will then build from the Southern Plains and extend into the Central Plains. Pressure falls over west central Kansas, however, will pull in warm and moist air by the mid to latter half of the week. An advancing shortwave trough should provide enough lift within this region to produce some precipitation within the warm sector of the low center by the late week. With no distinguishable boundary in place, any activity that does develop should remain relatively light. Continued southerly flow in place will push afternoon highs slightly above average before returning to normal by the end of the week. && .AVIATION...(For the 06Z TAFS through 06Z Saturday Night) Issued at 1054 PM CDT FRI SEP 18 2015 Isolated elevated convection will linger over northeast and central MO for a few hours past midnight. Patchy MVFR ceilings over south central IA advecting south-southwest into north central/northeast MO should break up shortly before sunrise. Otherwise, VFR conditions with light north winds. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ SHORT TERM...32 LONG TERM...Welsh AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
650 PM CDT FRI SEP 18 2015 .SHORT TERM...(This Evening through Sunday Night) Issued at 311 PM CDT FRI SEP 18 2015 Complicated forecast shaping up for the remainder of this afternoon and evening as long advertised front slowly works through the area. At 3 PM...regional radars showed a clearly defined fine line slowly working south through northwest Missouri and northeast Kansas...indicative of the current position of the boundary in question. As expected...sfc low across east-central Kansas continues to slowly lift northeastward along the boundary...with plenty of pre- frontal precipitation prevailing over the fcst region this afternoon. Looking aloft...afternoon water vapor imagery showing a nicely defined neutrally tilted trough axis digging through the Central Plains...with a mid-level jetstreak extending from east-central Colorado northeastward into south-central Nebraska. Forcing for ascent will continue to increase through the late afternoon/early evening as aforementioned wave approaches...but morning and early afternoon convection has certainly thrown a monkey wrench into today/s forecast. Latest visible satellite images finally showing some clearing in advance of the boundary this afternoon...and latest MLCAPE estimates from the SPC meso page are responding accordingly. Quick look at the GOES 7.4 micron channel shows leading edge of a secondary EML plume advancing east through west-central Kansas this afternoon...with new convection beginning to develop southwest of Topeka right ahead of the front. In the time its taken to write this much of the AFD...we/ve gone from little hope for severe to renewed optimism that things may in fact get going. That said...latest HRRR appears to be taking into account the partial clearing with decreased surface inhibition and now shows convection working through the KC Metro during the evening rush hour. As a result...all hope does is not lost as of right now anyways. If convection can in fact become organized /and there/s plenty of deep layer shear to support this/ large hail and damaging winds will be possible...especially if surface based inhibition erodes accordingly. Additionally...bulk shear vector orientation normal to the linear line of forcing will support supercell structures with eventual progression into linear segments as convection is able to congeal after sunset. Again...this scenario is only of marginal confidence at this point...and the next few hours will be telling on what is actually able to get organized...if anything. Additionally...concerns for heavy rainfall continue this afternoon as an axis of anomalously high PWAT values (> 1.7") remains entrenched across the fcst area. Combine this with the most recent images from the experimental layered PW satellite product from Colorado State which shows converging subtropical and northern stream moisture plumes over the Lwr Missouri Vly...organized rainfall should have little problem producing heavy rainfall rates across the area. Considering the amount of uncertainty with the going forecast this afternoon...will go ahead and leave the current flash flood watch in place until clearing begins to occur from west to east later tonight. Front to plow through the region overnight with precip quickly coming to an end after 6z or so. Dry air will quickly move in by Saturday morning as high pressure builds south across the Central Plains/upper Miss Rvr Vly. As cold air infiltrates the area...afternoon highs tomorrow afternoon will struggle to make it out of the upper 60s. Slightly warmer temps are expected on Sunday...with highs likely warming into the lower to middle 70s across most locations. Warming trend will commence early next week as southerly flow returns to the area. .LONG TERM...(Tuesday through Friday) Issued at 311 PM CDT FRI SEP 18 2015 Upper-level ridging will then build from the Southern Plains and extend into the Central Plains. Pressure falls over west central Kansas, however, will pull in warm and moist air by the mid to latter half of the week. An advancing shortwave trough should provide enough lift within this region to produce some precipitation within the warm sector of the low center by the late week. With no distinguishable boundary in place, any activity that does develop should remain relatively light. Continued southerly flow in place will push afternoon highs slightly above average before returning to normal by the end of the week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) Issued at 635 PM CDT FRI SEP 18 2015 Scattered thunderstorms along an eastward moving cold front will affect areas east of the terminals through around midnight. MVFR with embedded IFR ceilings with gusty north winds follow the passage of the front. Expect clouds to clear out from west to east after midnight. Thereafter, VFR conditions. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...FLASH FLOOD WATCH through Saturday morning for KSZ057-060- 103>105. MO...FLASH FLOOD WATCH through Saturday morning for MOZ006>008- 014>017-021>025-028>033-037>040-043>046-053-054. && $$ SHORT TERM...32 LONG TERM...Welsh AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
927 AM MDT THU SEP 17 2015 .UPDATE... VERY LITTLE CHANGE NEEDED TO THE GOING FORECAST THIS MORNING. WATER VAPOR IMAGERY SHOWED A STRONG SHORTWAVE AND JET DIVING INTO THE PACIFIC NW. THE WAVE WILL PUSH INTO THE SW ZONES THIS AFTERNOON AS WEAKER ENERGY EXITS THE E. WAVE WILL THEN MOVE THROUGH N WY TONIGHT THROUGH FRI MORNING. PRECIPITABLE WATERS WILL RUN AROUND A HALF INCH UNTIL THEY INCREASE TO /0.75/ INCHES THIS EVENING OVER THE SE. Q-VECTOR CONVERGENCE FROM THE STRONG WAVE WILL MOVE THROUGH THE AREA THIS AFTERNOON THROUGH 18Z FRI BRINGING INCREASING CHANCES FOR SHOWERS TO THE REGION FROM W TO E. MODELS ALL AGREED ON LOW CAPES /250-500 J/KG/ TODAY...BUT HAD STEEP LAPSE RATES. THEREFORE CANNOT RULE OUT A RUMBLE OF THUNDER. LATEST RADAR SHOWED PRECIPITATION MOVING TOWARD NW WY/BEARTOOTH/ABSAROKA MOUNTAINS...SO HAVE INCREASED POPS THERE TO LIKELY THIS MORNING AND SPREAD LIKELIES FURTHER N INTO KLVM AND N PARK COUNTY THIS AFTERNOON. OTHERWISE POPS WERE IN GOOD SHAPE WITH CHANCES MOVING INTO THE CENTRAL PART OF THE AREA AFTER 18Z. DOT REPORTS BLOWING/DRIFTING SNOW ON THE BEARTOOTH PASS FROM VISTA POINT TO THE MT STATE LINE AND ON THE WY SIDE OF THE PASS. THE PASS IS CLOSED IN THESE AREAS. SNOTELS AND WEB CAMS WERE NOT POSITIONED WELL TO PICK UP THE SNOW BUT RAP SOUNDINGS SHOWED SNOW LEVELS OF 8000 TO 9000 FT THIS MORNING. SNOW LEVELS DROP CLOSER TO 8000 FT FRI MORNING. TEMPERATURES SHOULD REACH THE 60S THIS AFTERNOON BASED ON MIXING TO AROUND OR BELOW 700 MB WHERE TEMPERATURES WILL BE AROUND ZERO DEGREES C. EXPECT A FAIR AMOUNT OF CLOUD COVER TODAY WITH THE MOISTURE MOVING IN AHEAD OF THE WAVE...BUT RAP SOUNDINGS STILL MIXED OUT THE LOWEST OF THE CLOUDS OVER THE SE ZONES. ARTHUR && .SHORT TERM...VALID FOR TDY AND FRI... 06Z UPPER ANALYSIS PLACED THE MEAN TROUGH AXIS JUST WEST OF MONTANA. TODAYS WAVE OF INTEREST CAN BE SEEN APPROACHING THE WESTERN COAST OF WASHINGTON AND WILL ADVECT ESE THROUGH TODAY. EXPECTING PRECIPITATION TO BEGIN IN THE WESTERN TERRAIN AND FOOTHILLS AROUND 15Z AND WILL SPREAD EASTWARDS THROUGH THE AFTERNOON. THIS WAVE SHOULD BEHAVE A LITTLE DIFFERENT THAN OUR LAST TWO AS UPPER LEVEL TEMPS WILL BE COLDER. WE ALSO SHOULD BE A LITTLE WARMER...BY A DEGREE OR TWO...IN THE LOWER LEVELS WHICH SHOULD HELP OVERALL INSTABILITY. THOUGH HOW MUCH INSTABILITY WE REALIZE WILL BE DEPENDENT ON HOW CLOUDY WE ARE. WARMER CONDITIONS IN SOUTHEAST MONTANA AND NORTHEAST WYOMING SHOULD ALLOW MORE INSTABILITY AND BETTER CHANCES FOR RAIN. MODELS ALSO SUGGEST THE 700MB LOW WRAPPING UP JUST EAST OF THE BIG HORN MOUNTAINS WHICH COULD ALLOW HIGHER RAINFALL AMOUNTS IN THESE LOCATIONS. .HIGH ELEVATION SNOWFALL IMPACTS... BIGGEST IMPACTS WITH THIS SYSTEM INVOLVE THE POTENTIAL HIGH ELEVATION SNOW IN THE BEARTOOTHS AND IN THE BIG HORNS. 700MB TEMPERATURES WILL BE MUCH COOLER WITH THIS SYSTEM AND THIS WILL BRING SNOW LEVELS DOWN TO AROUND 8000FT WITH FURTHER DECREASES TO NEAR 7500FT POSSIBLE BY EARLY FRIDAY MORNING. THOSE WITH ANY ACTIVITIES OR TRAVEL PLANS IN THE BEARTOOTH OR BIG HORN MOUNTAINS SHOULD PAY VERY CLOSE ATTENTION TO RAPIDLY CHANGING WEATHER CONDITIONS THIS AFTERNOON AND TONIGHT. SNOW ACCUMULATIONS ARE FORECAST TO BE AROUND 1 TO 3 INCHES...WITH MOST OF THESE ACCUMULATIONS ABOVE 9000 FT AND OCCURRING AFTER SUNSET WHEN SURFACE TEMPS COOL. WE COULD SEE HIGHER ACCUMULATIONS OF 2-4 INCHES IN THE BIG HORNS AS THE 700MB LOW WRAPS UP TONIGHT AND SOME NORTHERLY UPSLOPE WINDS...AND WRAP AROUND MOISTURE...COMBINE WITH SOME ENHANCED LAPSE RATES ALOFT. FOR FRIDAY UPPER LEVEL DISTURBANCE SHOULD CLEAR OUT OF EASTERN LOCATIONS AROUND NOON AND BRING MORE TRANQUIL CONDITIONS TO THE AREA. SHORTWAVE RIDGING SHOULD HELP INITIATE A GRADUAL WARM UP AS WE MOVE INTO THE EXTENDED. DOBBS .LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED... BENIGN WEATHER APPEARS TO BE IN STORE FOR US THROUGHOUT THE EXTENDED PERIOD. VERY WEAK SHORTWAVE ON SATURDAY WILL HAVE A DRY AIRMASS...RISING HEIGHTS AND DOWNSLOPE WINDS TO WORK WITH...SO AM COMFORTABLE LEAVING THE FORECAST DRY. HEIGHTS WILL CONTINUE TO RISE W/ FLAT RIDGING SUNDAY. SHOULD SEE HIGH TEMPS INTO THE MID 70S SATURDAY AND NEAR 80F SUNDAY...WITH SOME SW-W WIND EACH DAY. WE WILL BEGIN TO SEE THE EFFECTS OF SHORTWAVE ENERGY ACROSS SW CANADA WHICH WILL SUPPRESS THE RIDGE MONDAY. STILL SOME TIMING ISSUES WITH WHAT SHOULD BE A VERY WEAK FRONTAL PASSAGE EITHER MONDAY OR MONDAY NIGHT. WOULD EXPECT ANOTHER DAY OF ABOVE NORMAL TEMPS ON MONDAY...AND WILL SUSTAIN LOW POPS MONDAY AFTERNOON AND NIGHT TO COVER THE WEAK FORCING ASSOCIATED WITH THE FROPA AND SOME MID LEVEL MOISTENING. A LOW POP IS THE MOST THIS UNDYNAMIC SYSTEM DESERVES. MODELS ARE IN SOME DISAGREEMENT REGARDING THE POST-FRONTAL COOLING AND THE RETURN OF RISING HEIGHTS BY NEXT TUESDAY/WEDNESDAY. ECMWF AND CANADIAN BUILD HEIGHTS QUICKER WHEREAS THE GFS HOLDS ONTO A BIT STRONGER PACIFIC FLOW...AND AS A RESULT THE GFS IS THE COOLER SCENARIO. WILL STICK W/ A COMPROMISE BETWEEN THE TWO SOLUTIONS FOR TEMPS...IE TEMPS IN THE MID 70S TO LOWER 80S...BUT WE COULD SEE A RETURN OF MORE WIDESPREAD 80S IF WE SEE THE STRONGER RIDGING. EITHER WAY WILL KEEP OUR CWA DRY TUESDAY/WEDNESDAY OTHER THAN SOME LOW MOUNTAIN POPS. ONE OTHER ITEM OF NOTE IS THE SUBTROPICAL WAVE THAT ALL MODELS SHOW LIFTING OUT OF THE SW CONUS NEXT WEDNESDAY/THURSDAY. THE ECWMF SUGGEST THIS ENERGY WILL IMPACT OUR REGION BY THURSDAY WHEREAS THE GFS KEEPS IT TO OUR S/SE COURTESY OF THE MORE VEERED FLOW. THIS WILL BE SOMETHING TO KEEP AN EYE ON. JKL && .AVIATION... AREAS OF MVFR OR LOWER CIGS EXIST THIS MORNING ALONG AND EAST OF A GDV-MLS LINE. THESE LOWER CIGS SHOULD GRADUALLY LIFT BY MIDDAY. ANOTHER PACIFIC DISTURBANCE WILL BRING SHOWERS AND ISOLATED TSTMS BEGINNING IN THE WEST THIS AFTERNOON AND SPREADING EASTWARD THROUGH TONIGHT. AREAS OF MVFR CAN BE EXPECTED WITH THESE SHOWERS AND MOUNTAINS WILL BECOME FREQUENTLY OBSCURED. CHAMBERS && .PRELIMINARY POINT TEMP/POPS... TDY FRI SAT SUN MON TUE WED ------------------------------------------------------- BIL 065 044/068 044/073 049/080 054/081 049/076 049/079 3/T 52/W 10/B 00/U 01/U 21/B 11/B LVM 059 038/064 038/069 044/076 049/077 044/075 043/078 6/T 61/B 10/N 00/N 02/W 22/W 11/B HDN 069 044/070 040/075 044/081 047/082 047/079 046/082 2/T 42/W 10/B 00/U 01/U 21/B 11/B MLS 067 046/069 045/075 048/081 053/082 049/077 049/080 0/B 43/W 00/B 00/U 01/U 21/B 11/B 4BQ 066 046/066 043/074 046/080 049/082 049/079 047/080 1/B 64/W 00/B 00/U 00/U 21/B 11/B BHK 064 044/066 043/073 046/078 049/081 047/075 048/076 0/B 43/W 00/B 00/U 01/U 21/B 11/U SHR 068 042/067 037/073 041/081 044/083 045/080 044/081 3/T 64/W 00/B 00/U 00/U 21/B 11/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
310 PM CDT THU SEP 17 2015 .SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 306 PM CDT THU SEP 17 2015 COLD FRONT IS PROGRESSING THROUGH THE MID-MISSOURI VALLEY REGION TODAY. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES BROAD SOUTHWESTERLY FLOW ACROSS THE WESTERN AND CENTRAL US...WITH TROUGH AXIS FROM OR THROUGH NV/CA...AND WITH NORTHERN STREAM TROUGH NEAR THE AB/SASK BORDER TO MT. 500MB HEIGHT FALLS UP TO 50M WERE NOTED IN THE NORTH CENTRAL US. 850MB COLD FRONT EXTENDED FROM THE ONT/MB BORDER THROUGH THE ND/MN AND SD/MN BORDER...INTO CENTRAL TO SOUTHWEST NEB. AHEAD OF THE FRONT...AIRMASS WAS MOISTURE RICH...WITH DEWPOINTS OF 12C+ FROM THE MO VALLEY TO THE WESTERN GREAT LAKES...AND WITH 40-50KT WEST-SOUTHWESTERLY WINDS. 700-500MB TEMPERATURE DIFFERENCE WAS MAXIMIZED OVER NEB...AT THE NOSE OF THE 700MB THERMAL RIDGE. SURFACE COLD FRONT AT 19Z EXTENDED FROM SURFACE LOW IN WESTERN ONT...THROUGH CENTRAL MM...TO NEAR KDNS...TO KOMA...TO SECONDARY SURFACE LOW IN NORTH CENTRAL KS. ALONG AND AHEAD OF THE FRONT...CU FIELD HAD DEVELOPED...WITH DEWPOINTS IN THE UPPER 60S TO LOWER 70S. BEHIND IT...DEWPOINTS WERE IN THE 50S WITH QUICKLY CLEARING SKIES. MAIN FORECAST CONCERN IS CONVECTIVE DEVELOPMENT THIS AFTERNOON/EVENING...AND RAIN CHANCES TOMORROW. FRONT CONTINUES TO ADVANCE THROUGH THE CWA. AHEAD OF IT...CONVECTIVE DEVELOPMENT IS POSSIBLE THIS AFTERNOON...THOUGH NOT YET IMMINENT AS CU FIELD IS VISUALLY SHALLOW WITH NO ECHOES YET ON RADAR. RAP ANALYSIS INDICATES ABOUT 3000 J/KG UNCAPPED MLCAPE AHEAD OF THE FRONT...BUT MOST OF THE BULK SHEAR IS BEHIND THE FRONT. WITH THAT INSTABILITY...ANY STORMS THAT POP UP COULD BECOME BRIEFLY SEVERE...BUT THINK THEY MAY BE ON THE PULSY SIDE GIVEN THE MISALIGNED DEEP-LAYER SHEAR. FRONT IS MAKING FAIRLY RAPID PROGRESS...AND HAVE SPED THE EXIT OF STORMS IN THE SOUTH AND LOWERED POPS IN ALL BUT THE SOUTHERNMOST/SOUTHEASTERNMOST FRINGE OF THE CWA FOR THIS EVENING. FROM EARLY FRIDAY MORNING THROUGH THE AFTERNOON...UPPER-LEVEL TROUGH ADVANCES THROUGH THE NORTHERN ROCKIES AND TOWARD THE PLAINS...WITH LEE SURFACE LOW DEEPENING AND SLIDING ACROSS THE FRONTAL BOUNDARY THROUGH KS AND INTO NORTHERN MO/SOUTHERN IA. MOST OF THE CWA WILL BE WELL NORTH OF THE LOW...AND AS BAROCLINIC ZONE ON THE NORTHERN SIDE DEVELOPS AND RAIN DEVELOPS/EXPANDS...THINK WE MAINLY WILL SEE JUST DREARY RAIN AND PERHAPS A LITTLE EMBEDDED THUNDER...WITH A COUPLE OF THUNDERSTORMS POSSIBLE IN THE FAR SOUTHERN CWA IF ANYWHERE. RAIN SHOULD SHIFT EAST/SOUTHEAST OF THE CWA THROUGH THE AFTERNOON...WITH MOST OF THE AREA RAIN-FREE BY AROUND 00Z. HIGH PRESSURE WILL FOLLOW ON THE HEELS OF THE SYSTEM AND INFLUENCE THE AREA THROUGH SATURDAY...WITH QUIET AND COOLER WEATHER FRIDAY AND SATURDAY BEFORE TEMPERATURES MODERATE TOWARD NORMAL ON SUNDAY. RETURN FLOW ON SATURDAY NIGHT MAY SPARK A FEW SHOWERS/STORMS IN CENTRAL/WESTERN NEB ON SATURDAY NIGHT INTO SUNDAY MORNING...BUT THINK THIS ACTIVITY WILL STAY WEST OF THE CWA. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 306 PM CDT THU SEP 17 2015 RETURN FLOW CONTINUES INTO THE PLAINS INTO THE WORK WEEK...WITH AN UPPER-LEVEL RIDGE BUILDING INTO THE PLAINS THROUGH TUESDAY AND BRINGING MODERATING TEMPERATURES...BEFORE GIVING WAY TO SOUTHWESTERLY FLOW AS IT FLATTENS. AROUND WEDNESDAY/WEDNESDAY NIGHT...THE NEXT UPPER-LEVEL TROUGH TO PUSH ACROSS THE PLAINS WILL BRING A COLD FRONT AND ASSOCIATED SHOWER/THUNDERSTORM CHANCES. FRONT DOES NOT APPEAR TO HAVE A STRONG COLD PUSH THOUGH...AND NEAR TO ABOVE AVERAGE TEMPERATURES SHOULD CONTINUE THROUGH THURSDAY. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1229 PM CDT THU SEP 17 2015 AS OF 17Z...COLD FRONT EXTENDED FROM JUST EAST OF KOFK...TO KFET TO KHJH. SOME SCT TO MVFR BKN CU WAS IN THE VICINITY OF THE FRONT AND WINDS WERE SHIFTING TO THE NORTH NORTHWEST BEHIND THE FRONT. EXPECT SHOWERS AND THUNDERSTORMS TO FORM IN ADVANCE OF THE COLD FRONT BUT SHOULD REMAIN EAST OF ALL THREE TAF SITES THIS AFTERNOON AND EVENING. AFTER 14Z WINDS WILL BECOME NORTHEAST ON THE BACKSIDE OF THE COLD FRONT WHICH IS A GOOD FLOW TO PRODUCE RAIN AND FOG. HAVE ADDED A TEMPO GROUP TO ALL THREE TAF SITES TO HINT AT THIS POSSIBILITY LATE IN THE FORECAST PERIOD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MAYES LONG TERM...MAYES AVIATION...MEYER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
125 AM EDT THU SEP 17 2015 .SYNOPSIS... HIGH PRESSURE CENTERED TO OUR NORTH WILL WEAKEN GRADUALLY THROUGH THE REMAINDER OF THE WEEK. A TROUGH OF LOW PRESSURE WILL RESIDE ALONG THE COAST. THERE WILL BE A RISK FOR SHOWERS...PRIMARILY ALONG THE COAST INTO THE WEEKEND. A COLD FRONT WILL DROP SOUTH OF THE AREA EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 945 PM WEDNESDAY...SFC HIGH CENTERED OVER LAND...THE VA CAPES ATTM...AND WILL CONTINUE TO FUNNEL RELATIVELY DRY AIR ACROSS THE FA AT THE LOW LEVELS...WITH MUCH OF IT FELT ACROSS THE ILM NC CWA. THIS HAS KEPT THE LOW AND MID LEVELS RELATIVELY DRY WITH ONLY CI/CS...OCCASIONALLY OPAQUE...PUSHING ACROSS THE ENTIRE ILM CWA. LATEST VARIOUS MODEL TIME HEIGHT DISPLAYS ACROSS THE FA SUPPORT THIS OCCURRING THRU THE EVENING AND OVERNIGHT. THE FLY IN THE OINTMENT...IS THE TROUGHINESS IN THE MID AND UPPER LEVELS ACROSS THE NE GULF OF MEXICO EXTENDING INTO THE SOUTHEAST UNITED STATES. MODELS DO INDICATE THIS FEATURE DRIFTING TOWARD THE NE- ENE OVERNIGHT. THIS WILL RESULT IN SOME SHARPENING OF THE INVERTED SFC TROF OFF THE SOUTHEAST U.S. COAST OVERNIGHT INTO THE SHORT TERM PERIOD. IN ADDITION...LOOK FOR MOISTURE TO INCREASE AT ALL LEVELS MAINLY ACROSS THE ILM SC CWA...MAINLY WELL SOUTH AND EAST OF THE I-95 CORRIDOR TO THE SC COAST. HAVE CONCENTRATED THE INCREASE IN POPS MAINLY ACROSS THE COASTAL COUNTIES OF THE ILM SC CWA...AND MAINLY AFTER MIDNIGHT. THE LATEST RAP MODEL RUN HOLDS OFF THE DEEPER MOISTURE FROM REACHING THE ILM NC COASTAL CWA OVERNIGHT. HAVE BASICALLY KEPT A DRY BIAS ACROSS THE ILM NC CWA...WITH ONLY AN ISOLATED -SHRA POSSIBLE ALONG THE IMMEDIATE NC COAST FROM ROUGHLY CAPE FEAR SOUTHWARD OCCURRING AROUND DAYBREAK THU. SOME MASSAGING OF THE MIN TEMPS...SLIGHTLY LOWER BY A DEGREE OR 2 MAINLY ACROSS THE ILM NC CWA...AND ACROSS THE NW PORTIONS OF THE ILM SC CWA. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...A COASTAL TROUGH OR PERHAPS EVEN A VERY MEEKLY CLOSED OFF WILL VERY SLOWLY TAKE SHAPE OVER THE COURSE OF THE SHORT TERM PERIOD. THERE WILL ALSO BE A TROUGHINESS IN THE MID LEVELS RUNNING FROM THE FL BIG BEND TO THE OUTER BANKS OF NC. TOGETHER THESE WILL CHANNEL FAIRLY DEEP MOISTURE UP THE COAST. MODELS ARE HAVING DIFFICULTY RESOLVING THE WESTWARD EXTENT OF THE MOISTURE AND THUS RAIN CHANCES. ADVECTING PRECIPITATION TOO FAR AND TOO FAST IS A COMMON MODEL ERROR SO THE HIGH POPS AND QPF OF THE GFS HAVE BEEN DOWNPLAYED IN FAVOR OF THE MUCH MORE CONSERVATIVE ECMWF. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 300 PM WEDNESDAY...SATURDAY WILL BEGIN WITH A TROUGH SFC- ALOFT MOVING SLOWLY EASTWARD ACROSS SC-GA-FL. THE TROUGH WILL SLOW BY SUNDAY AND LINGER OFF THE SOUTHEAST CONUS INTO TUESDAY. THERE WILL GOOD POTENTIAL FOR SHOWERS TO AFFECT THE CWA SATURDAY AS DEEP MOISTURE CIRCULATES ONSHORE AND PRECIPITABLE WATER VALUES EXCEED TWO INCHES ACROSS THE EASTERN HALF OF THE CWA. THE MOISTURE GRADIENT WILL BE SOMEWHAT TIGHT HOWEVER...SO IF THE TROUGH REMAINS FAR ENOUGH OFFSHORE...PRECIP CHANCES WOULD BE SIGNIFICANTLY LOWER. FOR SUNDAY-WEDNESDAY...THE FORECAST UNCERTAINTY INCREASES AS THE GFS AND ECMWF DIFFER ON HOW THIS TROUGH WILL INTERACT WITH ANOTHER SHARP TROUGH APPROACHING FROM THE WEST. THOUGH BOTH MODELS BRING DRIER MID-LEVEL AIR ACROSS THE AREA ON SUNDAY...THE ECMWF DRAWS THE TROUGH AND ASSOCIATED MOISTURE WESTWARD EARLY NEXT WEEK WHILE THE GFS KEEPS IT FURTHER OFFSHORE. DUE TO THIS UNCERTAINTY...PLAN TO INCLUDE AT LEAST A SMALL POP EACH DAY EXCEPT SUNDAY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... AS OF 06Z...A COASTAL TROUGH WILL SLOWLY MOVE NORTH DURING THE NEXT 24 HOURS. LOOK FOR MAINLY A MID CLOUD CEILING OVERNIGHT... INTERMITTENTLY A VFR STRATOCUMULUS CEILING. TIME HEIGHT SECTIONS SHOW CEILINGS SLOWLY LOWERING OVERNIGHT...WITH A 4K DECK OVER MUCH OF THE COAST BY MORNING. THINK THERE WILL BE ENOUGH ONSHORE MOISTURE TO PRODUCE WEAK SHOWERS AT THE MYRTLES. THE PRECIP MAY MAKE IT AS FAR NORTH AS ILM...HOWEVER IT WILL TAKE QUITE A FEW HOURS LONGER. INLAND TERMINALS WILL REMAIN VFR WITH NO PRECIP EXPECTED THROUGH THE END OF THE FORECAST PERIOD. EXTENDED OUTLOOK...COASTAL SHOWERS ARE POSSIBLE THROUGH SATURDAY OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 945 PM WEDNESDAY...SFC HIGH TO REMAIN CENTERED ACROSS THE VA CAPES THIS EVENING AND OVERNIGHT...AND WILL RIDGE SW ACROSS THE CENTRAL CAROLINAS INTO DAYTIME THU. AT THE SAME TIME...AN INVERTED SFC TROF WILL FURTHER DEVELOP AND EXTEND NE ACROSS THE OFFSHORE WATERS OFF THE CAROLINAS...NEARLY PARALLEL TO THE CAROLINAS COASTLINES. SOME MODELS INDICATE A TIGHTENING OF THE SFC PG IN THE VICINITY OF THE ILM SC WATERS AND THUS WILL GO AHEAD AND INDICATE A SOLID 15 KT...TO POSSIBLY 20 KT ACROSS THE SOUTHERNMOST PORTIONS OF THE ILM COASTAL WATERS. SIGNIFICANT SEAS WILL RUN AROUND 3 FT FOR THE ILM NC WATERS...AND POSSIBLY BUILD TO A SOLID 4 FT FOR THE SOUTHERNMOST ILM SC WATERS DURING THE OVERNIGHT. WITH THIS PERSISTENT ONSHORE FLOW...A SEMI-GROUND SWELL SO TO SPEAK...WILL AFFECT THE AREA WATERS RUNNING AT 6 TO 7 SECOND PERIODS. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 300 PM WEDNESDAY...THE LARGE AREA OF HIGH PRESSURE THAT HAS BEEN BRINGING NORTHEASTERLY WINDS FOR A WHILE NOW WILL GRADUALLY WEAKEN AND DRIFT EASTWARD THROUGH THE PERIOD. MEANWHILE AN UPPER LEVEL TROUGH LINING UP ALONG THE COAST WILL INDUCE A SURFACE WAVE OF LOW PRESSURE THAT MAY EVEN TRY TO FORM A WEAKLY CLOSED LOW. THIS TROUGHINESS WILL OFFSET THE WEAKENING OF THE HIGH TO KEEP WIND SPEEDS FAIRLY STEADY IN THE 10-15KT RANGE OVER MOST ZONES AND SOME GUSTS TO 20 ARE POSSIBLE LATE IN THE PERIOD AS LOW LEVEL JETTING INCREASES SOME. A FEW 4 FT SEAS MAY APPEAR ALONG THE EASTWARD EXTREME OF SOME OF THE MARINE ZONES. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 300 PM WEDNESDAY...SURFACE LOW PRESSURE IS EXPECTED TO DEVELOP OFF THE SOUTH CAROLINA COAST SATURDAY AND LINGER OFF THE SOUTHEAST COAST OF THE CONUS THROUGH MONDAY. GIVEN THE PROXIMITY OF THE LOW...THE AREA WATERS SHOULD REMAIN IN A GENERAL NORTHEAST FLOW IN THE 15-20 KNOT RANGE. EXPECT SEAS OF 3-4 FEET THROUGH THE PERIOD...CLOSER TO 2 FEET IN THE SHELTERED WATERS SOUTH OF CAPE FEAR...BUT WINDS AND SEAS LOOK TO TREND HIGHER SUNDAY NIGHT AND MONDAY AS HIGH PRESSURE BUILDS OVER THE CAROLINAS AND THE PRESSURE GRADIENT INTENSIFIES OVER THE WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH SHORT TERM...MBB LONG TERM...CRM AVIATION...RJD/DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1239 AM CDT THU SEP 17 2015 .UPDATE... ISSUED AT 1235 AM CDT THU SEP 17 2015 A MINOR UPDATE TO ACCOUNT FOR LATEST TRENDS. THE TROUGH AXIS CURRENTLY BISECTS THE STATE. EAST OF THE AXIS SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP. WEST OF THE AXIS GUSTY NORTHWEST WINDS AND LOWER CLOUDS WERE MOVING IN. UPDATED THE LATEST PRECIPITATION FORECAST BASED ON RADAR TRENDS AND HIGH RESOLUTION SHORT TERM MODELS. UPDATE ISSUED AT 1027 PM CDT WED SEP 16 2015 AS OF 330 UTC...ELEVATED CONVECTION ASSOCIATED WITH A WARM FRONT ACROSS THE I-94 CORRIDOR IN A LOW CAPE...HIGH SHEAR ENVIRONMENT HAS DISPLAYED LOW-TOPPED SUPERCELLULAR CHARACTERISTICS OVER THE PAST 1-2 HOURS. THIS INCLUDES THE STORM THAT IMPACTED THE DICKINSON AREA EARLIER THIS EVENING. THUS...EXPECT A MARGINAL THREAT FOR SEVERE HAIL AND WIND GUSTS TO PERSIST THROUGH 06-07 UTC ACROSS THE I-94 THROUGH ND HIGHWAY 200 CORRIDORS. UPDATE ISSUED AT 651 PM CDT WED SEP 16 2015 NO SIGNIFICANT CHANGES REQUIRED WITH THIS UPDATE AS A TIME LAGGED ENSEMBLE OF THE 21-23 UTC HRRR ITERATIONS MATCHES WELL WITH ONGOING RADAR TRENDS THROUGH 00 UTC AHEAD OF MULTIPLE SHORTWAVES ACROSS EASTERN MONTANA INTO NORTHWEST SOUTH DAKOTA. GIVEN WEAK INSTABILITY...THE PREDOMINANT MODE OF PRECIPITATION IS EXPECTED TO BE RAIN SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS. SEVERE WEATHER IS NOT EXPECTED. && .SHORT TERM...(THIS EVENING THROUGH THURSDAY) ISSUED AT 216 PM CDT WED SEP 16 2015 A STRONG UPPER LEVEL SHORTWAVE TROUGH AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL BRING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TO WESTERN AND CENTRAL NORTH DAKOTA TONIGHT. FOLLOWED BY COOLER TEMPERATURES AND BREEZY CONDITIONS ON THURSDAY. CURRENTLY...SHORTWAVE TROUGH FROM CENTRAL MONTANA INTO WESTERN WYOMING IS LIFTING NORTHEAST THROUGH THE WESTERN U.S. UPPER LEVEL LONGWAVE TROUGH. LEADING EDGE OF SHOWER ACTIVITY EXTENDS TO AROUND WOLF POINT AND MILES CITY IN EASTERN MONTANA. SURFACE LOW PRESSURE WAS SITUATED OVER NORTHEAST WYOMING WITH AND INCREASING SOUTHEAST SURFACE FLOW OVER SOUTHWEST NORTH DAKOTA...AND AN INCREASING EAST TO NORTHEAST SURFACE FLOW ELSEWHERE. LATE THIS AFTERNOON AND TONIGHT. EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO INCREASE OVER EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE THIS AFTERNOON AS THE SURFACE LOW TRACKS INTO NORTHWEST NORTH DAKOTA. THERE IS SOME WEAK INSTABILITY ALOFT LATE THIS AFTERNOON INTO EARLY THIS EVENING OVER WESTERN NORTH DAKOTA. BUT LOW LEVEL INHIBITION REMAINS STRONG. WE DO SEE INCREASING LAPSE RATES LATER THIS AFTERNOON AND WITH THE STRONG DYNAMIC WAVE LIFTING THROUGH THE AREA...AN ISOLATED SEVERE WIND GUST COULD BE POSSIBLE. BUT GENERALLY THINK SCATTERED TO NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS LIFTING FROM WESTERN INTO NORTH CENTRAL NORTH DAKOTA ALONG AND NORTH OF THE SURFACE LOW THAT TRACKS ACROSS THE NORTH DAKOTA/SOUTH DAKOTA BORDER. ON THURSDAY...SCATTERED SHOWERS WILL REMAIN ALONG THE INTERNATIONAL BORDER...CLOSER TO THE COLD AIR ASSOCIATED WITH THE UPPER LEVEL TROUGH. FARTHER SOUTH...PERHAPS A LINGERING SHOWER ACROSS THE SOUTH CENTRAL...BUT EXPECT INCREASING SUBSIDENCE THROUGH THE DAY WITH HIGH PRESSURE BUILDING OVER THE AREA. BREEZY CONDITIONS DURING THE MORNING AND EARLY AFTERNOON WITH DIMINISHING WINDS MID TO LATE AFTERNOON AS THE SURFACE HIGH BUILDS OVER THE STATE. .LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY) ISSUED AT 216 PM CDT WED SEP 16 2015 SHOWERS AND THUNDERSTORMS HIGHLIGHT THE FORECAST FOR THURSDAY NIGHT AND FRIDAY...WHILE DRY AND SEASONABLE CONDITIONS BECOME THE FOCUS FOR THE WEEKEND. THURSDAY NIGHT...A DEPARTING SHORTWAVE WILL KEEP AN ISOLATED SHOWER OR TWO POSSIBLE IN THE NORTHEAST PART OF THE COUNTY WARNING AREA... WITH A BRIEF PERIOD OF CLEARING ACROSS THE STATE FROM WEST TO EAST. EARLY FRIDAY MORNING...THE NEXT SHORTWAVE WILL MOVE INTO SOUTH DAKOTA FROM WYOMING...INCREASING CLOUD COVER AND PRECIPITATION CHANCES OVER OUR SOUTHERN ZONES. 12Z NAM/GFS MODEL RUNS SUGGEST THE BEST CHANCES FOR SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM WILL RESIDE OVER SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA...MAINLY ALONG AND SOUTH OF INTERSTATE 94 FRIDAY MORNING AND INTO THE EARLY AFTERNOON. MEAGER INSTABILITY FROM MODEL FORECAST SOUNDINGS SHOULD KEEP THUNDERSTORM COVERAGE AND STRENGTH TO A MINIMUM. HIGH TEMPERATURES ON FRIDAY WILL REMAIN ON THE COOL SIDE...GENERALLY IN THE 60S. SATURDAY WILL FEATURE DRY AND SEASONABLE CONDITIONS WITH HIGHS IN THE LOWER 70S. PLEASANT WEATHER WILL CONTINUE THROUGH MONDAY...WITH TEMPERATURES WARMING SLIGHTLY EACH DAY. THE NEXT CHANCES FOR PRECIPITATION WILL BE OVERNIGHT MONDAY AND INTO TUESDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1235 AM CDT THU SEP 17 2015 SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE ACROSS CENTRAL AND EASTERN NORTH DAKOTA LATE TONIGHT. CEILINGS ARE EXPECTED TO LOWER TO MVFR AT KISN/KDIK/KMOT TONIGHT. KJMS AND KBIS ARE MORE UNCERTAIN REGARDING POTENTIAL STRATUS IMPACTS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AJ SHORT TERM...TWH LONG TERM...ZH AVIATION...AJ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
424 PM EDT THU SEP 17 2015 .SYNOPSIS... A COLD FRONT WILL APPROACH ON FRIDAY BEFORE PUSHING THROUGH THE OHIO VALLEY ON SATURDAY...ALLOWING FOR SHOWERS AND PERHAPS A FEW THUNDERSTORMS. HIGH PRESSURE AND COOLER TEMPERATURES WILL BUILD IN BEHIND THE FRONT ON SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A SURFACE RIDGE WILL EXTEND WEST BACK INTO THE UPPER OHIO VALLEY OVERNIGHT WHILE A COLD FRONT SLOWLY SAGS SOUTHEAST TO THE WESTERN GREAT LAKES. IT SHOULD START OFF MAINLY CLEAR THIS EVENING. THEREAFTER...CLOUDS WILL INCREASE FROM THE NORTHWEST OVERNIGHT DUE TO UPSTREAM CONVECTION. MODELS CONTINUE TO INDICATE THAT AN EMBEDDED S/WV...MODEST LOW LEVEL JET...AND FRONTAL ZONE WILL PRODUCE PCPN TO OUR WEST/NORTHWEST OVERNIGHT...WEAKENING THE COVERAGE AS IT MOVES SOUTHEAST TOWARD SUNRISE. THERE COULD BE A FEW SHOWERS THAT SNEAK IN TO OUR FAR NORTHWEST ZONES BY MORNING. OTHERWISE...THE EAST/SERN CWFA WILL REMAIN MOSTLY CLEAR. LOWS WILL VARY FROM THE LOWER 50S IN THE COOLER LOCATIONS OF EAST CENTRAL AND SOUTH CENTRAL OHIO TO THE LOWER 60S FAR NORTHWEST DUE TO LIGHT SOUTHERLY WINDS AND INCREASING CLOUDS. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... HAVE USED A BLEND OF THE GFS AND ECMWF FOR THE SHORT TERM FORECAST. COLD FRONT WILL MOVE A LITTLE FARTHER SOUTHEAST ON FRIDAY BUT WILL REMAIN WELL TO OUR NORTHWEST. THERE COULD BE CONSIDERABLE CLOUDS DURING THE MORNING HOURS RESULTING FROM PREVIOUS NIGHTS CONVECTION TO OUR NORTHWEST. AGAIN...A FEW SHOWERS MAY BE SKIMMING OUR NORTHWEST ZONES DURING THE MORNING. IT LOOKS LIKE ANY SHOWER/THUNDERSTORM ACTIVITY WILL REMAIN CLOSER TO THE FRONT FOR THE AFTERNOON HOURS. TEMPERATURES WILL BE CLOUD DEPENDENT BUT SHOULD WARM INTO THE LOWER AND MID 80S ONCE AGAIN. FOR FRIDAY NIGHT...POTENT S/WV WITHIN THE FLOW ALOFT WILL EJECT NORTHEAST TO THE GREAT LAKES. A STRONG LLJ WILL TEAM UP WITH FAVORABLE UPR DIV FROM THE RR QUAD OF AN UPR LVL JET TO PERTURB A WAVE LOW PRESSURE ON THE FRONT. WIDESPREAD PCPN IS EXPECTED FROM NRN IL...SRN WI...NRN IND...SRN MI AND THEN INTO NW OHIO. OUR AREA WILL BE ON THE PERIPHERY OF THE BEST LOW LEVEL FORCING SO ONLY HAVE CHANCE POPS IN THE FORECAST FOR THE NW TAPERING OFF TO A DRY FORECAST MAINLY ALONG AND SOUTHEAST OF I-71. OVERNIGHT LOWS WILL BE MAINLY IN THE 60S. ON SATURDAY...AS WAVE OF LOW PRESSURE PASSES BY TO OUR NORTHEAST... ATTENDANT COLD FRONT THEN WILL MOVE THROUGH OUR AREA. THE FRONT WILL INTERACT WITH FAIRLY HIGH PWATS. HOWEVER...LIFT WILL BE MAINLY FROM LOW LEVEL FRONTAL CONVERGENCE ALONG AND AHEAD OF THE FRONT. WE SHOULD AT LEAST SEE LIKELY POPS FOR OUR WESTERN HALF OF THE CWFA...BUT FRONTAL CONVERGENCE SEEMS TO WEAKEN AS IT MOVES THROUGH THE REMAINDER OF THE AREA SATURDAY AFTERNOON AND EVENING...SO HAVE CHANCE POPS ELSEWHERE. THERE SHOULD BE ENOUGH INSTABILITY FOR EMBEDDED THUNDER. BY SATURDAY NIGHT...THE COLD FRONT WILL EXIT TO OUR SOUTHEAST... ALLOWING SURFACE HIGH PRESSURE TO BUILD IN FROM THE NORTHWEST. DRIER AND COOLER WEATHER WILL FILTER INTO THE REGION. LOWS WILL BOTTOM OUT IN THE UPPER 40S NORTH TO THE MID 50S ALONG AND SOUTH OF THE OHIO RIVER. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... AT THE START OF THE EXTENDED FORECAST PERIOD...A COLD FRONT WILL BE JUST SOUTHEAST OF THE ILN FORECAST AREA...WITH HIGH PRESSURE BUILDING INTO THE SOUTHERN GREAT LAKES AND NORTHERN OHIO VALLEY. THIS HIGH WILL BE FAIRLY DRY...PROVIDING A MOSTLY SUNNY DAY ON SUNDAY...WITH HIGHS IN THE LOWER TO MID 70S. THE FOCUS GOING INTO THE FIRST HALF OF THE WEEK WILL BE ON THE FORMATION OF AN AREA OF UPPER LEVEL LOW PRESSURE...WHICH WILL DEVELOP AS THE SURFACE HIGH TRANSLATES NORTHEAST. AT THE SAME TIME...A SSW-TO-NNE ORIENTED SURFACE TROUGH WILL DEVELOP JUST WEST OF THE APPALACHIAN MOUNTAINS...WITH MOISTURE AND PRECIPITATION SPREADING ALONG THE MOUNTAINS AND INTO THE UPPER OHIO AND TENNESSEE VALLEY REGIONS BY MONDAY NIGHT. THERE IS DECENT AGREEMENT BETWEEN THE 12Z GFS/ECMWF THROUGH TUESDAY...AND BOTH MODELS SUGGEST THAT MOST OF THE PRECIPITATION WILL REMAIN EAST OF THE ILN FORECAST AREA. THUS...POPS HAVE BEEN SLIGHTLY LOWERED FROM THE PREVIOUS FORECAST...WITH ONLY SLIGHT CHANCES OF SHOWERS EXPECTED ON MONDAY AND TUESDAY (PERHAPS A LITTLE MORE LIKELY ON TUESDAY). WITH MODELS INDICATING RELATIVELY STABLE CONDITIONS...THUNDER SEEMS UNLIKELY. MODEL SPREAD INCREASES SIGNIFICANTLY BY WEDNESDAY...PRIMARILY WITH REGARD TO THE LOCATION AND STRENGTH OF THE UPPER LOW. THE 12Z OPERATIONAL RUNS LOOK VASTLY DIFFERENT TODAY THAN THEY DID YESTERDAY. GFSE MEMBERS ARE SHOWING A POSITIONAL SPREAD OF AROUND 400 MILES WITH REGARDS TO THE CENTER OF THE UPPER LOW BY 12Z WEDNESDAY MORNING...AND ARE SPREAD OUT ENOUGH BY WEDNESDAY EVENING THAT THE ENSEMBLE MEAN IS SO DAMPENED AS TO MISS THE PRESENCE OF THE CLOSED LOW ENTIRELY. THUS...THE FORECAST BEYOND TUESDAY IS OF VERY LOW CONFIDENCE. A GRADUAL WARMING TREND THROUGH THE WEEK WILL BE FORECAST...WITH TEMPERATURES RETURNING TO NEAR NORMAL BY THE MIDDLE OF THE WEEK. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... FEW TO SCATTERED CU ARE EXPECTED AGAIN THIS AFTERNOON BEFORE MIXING OUT BEFORE SENT. SFC HIGH PRESSURE WILL FINALLY GIVE WAY TONIGHT...RETREATING A LITTLE TO THE EAST. AS THIS OCCURS A H5 S/W WILL PUSH INTO THE WRN GREAT LAKES AFT 00Z. AREA OF CONVECTION IS FORECAST TO PUSH E THROUGH NRN ILLINOIS INTO NRN INDIANA AND POSSIBLY INTO NW OHIO BY 12Z. A CIRRUS CIG IS EXPECTED TO WORK INTO THE TAFS AHEAD OF THE CONVECTION. CONDITIONS SHOULD BE VFR OVERNIGHT FOR THE TAFS...EXCEPT FOR LUK...WHERE FOG IS EXPECTED AGAIN. NOT THAT CONFIDENT ON EXACTLY HOW LOW THE VSBYS WILL DROP WITH THE HIGHER CLOUDS WORKING IN. TOOK LUK DOWN TO MVFR BETWEEN 06-12Z FOR NOW. THE ABOVE MENTIONED CONVECTION WILL BE WEAKENING AS IT HEADS EAST...BUT COULD HOLD TOGETHER FRIDAY MORNING. THREW IN A VCSH AFT 12Z AT DAY TO COVER THE POSSIBILITY OF PCPN IN THE AREA. OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...CONIGLIO/HICKMAN NEAR TERM...HICKMAN SHORT TERM...CONIGLIO/HICKMAN LONG TERM...HATZOS AVIATION...SITES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
145 PM EDT THU SEP 17 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE ALONG THE EAST COAST WILL WEAKEN AND MOVE EAST THIS WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE THROUGH SATURDAY AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES AND LOWER OHIO VALLEY ON SUNDAY AND LINGER EARLY IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...UPDATED HOURLY AND MAX TEMPS BASED ON HRRR AND CURRENT READINGS. ORIGINAL...HIGH PRESSURE IN CONTROL. THE PATCHY CIRRUS IS GONE. LOW LEVEL MOISTURE IS PROGGED TO INCREASE SLIGHTLY TODAY...JUST ENOUGH FOR A FEW MORE FAIR WEATHER CUMULUS BUT STILL A SUNNY DAY. TOOK YESTERDAYS HIGH TEMPERATURES AND ADDED A DEGREE TO MOST SITES FOR THE FORECAST MAX. THE GRADIENT IS LIGHT ENOUGH AGAIN FOR A LAKE BREEZE...ESPECIALLY FROM AROUND CLEVELAND EAST...SO TEMPS WILL DROP BACK A COUPLE OF DEGREES AT THE LAKESHORE THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... THE MODELS CONTINUE TO SHOW THE INITIAL BATCH OF SHOWERS/STORMS MAKING A RUN FOR THE FORECAST AREA ON FRIDAY OUT AHEAD OF THE COLD FRONT. THE AIR MASS WILL BE RELATIVELY DRY AND STABLE BUT THERE WILL LIKELY BE ENOUGH ELEVATED INSTABILITY TO ALLOW THE SHOWERS TO SURVIVE AS THEY CROSS MICHIGAN AND SPREAD ACROSS THE TOLEDO AREA AND WESTERN LAKE ERIE. NOT SURE IF IT WILL BE A FEW SPRINKLES...A FEW HUNDREDTHS... OR RESPECTABLE SHOWERS. WILL HAVE A CHANCE OF SHOWERS/STORMS MAINLY FOR NORTHWEST OHIO BUT CANNOT RULE OUT A SHOWER/SPRINKLES SNEAKING ACROSS THE NORTHERN COUNTIES ON FRIDAY. STILL SOME TIMING DIFFERENCES AMONG MODELS ON SATURDAY WITH THE COLD FRONTAL PASSAGE BUT THE GFS AND ECMWF ARE IN RELATIVE AGREEMENT AND USED THEIR TIMING. NOT OVERLY EXCITED ABOUT THUNDERSTORMS...THE MID LEVEL LAPSE RATES ARE WEAK...BUT THERE IS MODERATE SHEAR AND SOME LOW LEVEL CAPE. WE WILL PROBABLY END UP WITH A FEW THUNDERSTORMS. IT WILL PROBABLY BE A BREEZY DAY AHEAD OF THE FRONT. TEMPS ARE TRICKY ON SATURDAY DEPENDING ON HOW FAST THE CLOUDS AND SHOWERS MOVE EAST. THE FORECAST ASSUMES THERE IS TIME FOR WARMING FOR NE OH/NW PA WITH HIGHS AROUND 80/LOWER 80S. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON SUNDAY. THE NORTHEAST ANTICYCLONIC FLOW AND SUBSIDENCE SHOULD PROVIDE FOR PARTIAL CLEARING ALTHOUGH SOME HIGH CLOUDS MAY LINGER. COOLER...FEELING MORE LIKE FALL...WITH HIGHS FROM THE MID 60S TO LOWER 70S. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... IT WILL BE PREDOMINATELY DRY THROUGH THE FIRST HALF OF THE WORK WEEK...BUT AN UPPER TROUGH AND SOME MOISTURE FEEDING INTO THE REGION MAY BE ENOUGH FOR A FEW SHOWERS. GFS AND CANADIAN SIMILAR IN KEEPING US DRY. THE ECMWF IS ON THE OTHER EXTREME AND PAINTS OUT QPF. FEEL IT WILL BE HARD TO GET TOO DEEP OF MOISTURE INTO THE AREA WITH THE SURFACE HIGH SITTING TO OUR NORTH. WILL HAVE SILENT 20 PERCENT PRECIP CHANCES ACROSS THE EASTERN HALF OF THE AREA TUESDAY AND WEDNESDAY. TEMPERATURES REAL CLOSE TO NORMAL AND GUIDANCE TEMPS CLUSTERED TOGETHER. TEMPS AROUND 70 ON MONDAY INCHING UP TO THE LOWER 70S FOR WEDNESDAY. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS CONTINUE AS HIGH PRESSURE SLIDES OFF TO THE EAST. THE WIND WILL TRY AND COME AROUND NNW LATE THIS AFTN OFF THE LAKE AT KCLE AND KERI. FARTHER WEST...AT KTOL AND KFDY...THE WIND WILL BEGIN TO GUST FROM THE SSW THROUGH SUNSET. AFTER SUNSET ALL SITES WILL OBSERVE S TO SW FLOW 5 KTS OR LESS. BY 12Z FRI A WEAK COLD FRONT WILL BE LOCATED JUST WEST OF KTOL. THIS FRONT WILL WEAKEN AS IT MOVES E ACROSS NORTHERN OH...SO ONLY MENTIONING -TSRA AT KCLE AND KFDY STARTING AROUND 15Z...AND VCTS AT KCLE AFTER 18Z. THE BETTER CHANCES CONTINUE TO COME AFTER THE TAF PERIOD WITH A SECONDARY FRONT AND LOW. OUTLOOK...NON-VFR POSSIBLE WITH SHOWERS AND A CHANCE OF THUNDERSTORMS FRI NIGHT INTO SAT NIGHT. && .MARINE... HIGH PRESSURE IS INCHING EASTWARD...ENOUGH NOW TO GIVE A SOUTHWEST BREEZE TODAY THROUGH FRIDAY. STILL EXPECT A LAKE BREEZE/ONSHORE FLOW TO DEVELOP FOR THE EASTERN HALF OF THE NEARSHORE WATERS TODAY...LESS SO FOR FRIDAY. THE LATEST TIMING TAKES A COLD FRONT ACROSS THE LAKE DURING THE DAYLIGHT HOURS ON SATURDAY. MOST OF THE GUIDANCE IS CLUSTERED THERE. WHAT IS ALSO FAIRLY WELL AGREED UPON NOW IS THERE WILL BE SOME WIND BEHIND THE FRONT FOR A TIME BEFORE THE HIGH BUILDS IN SUFFICIENTLY TO CALM THINGS DOWN. A SMALL CRAFT ADVISORY IS LIKELY LATE SATURDAY INTO SUNDAY. WITH HIGH PRESSURE SITTING NORTH OF THE LAKE ON MONDAY...WILL KEEP A LIGHT NORTHEAST FLOW GOING. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KOSARIK NEAR TERM...TK/KOSARIK SHORT TERM...KOSARIK LONG TERM...OUDEMAN AVIATION...MAYERS MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1134 AM EDT THU SEP 17 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE ALONG THE EAST COAST WILL WEAKEN AND MOVE EAST THIS WEEKEND. THIS WILL ALLOW A COLD FRONT TO MOVE THROUGH SATURDAY AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES AND LOWER OHIO VALLEY ON SUNDAY AND LINGER EARLY IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATE...UPDATED HOURLY AND MAX TEMPS BASED ON HRRR AND CURRENT READINGS. ORIGINAL...HIGH PRESSURE IN CONTROL. THE PATCHY CIRRUS IS GONE. LOW LEVEL MOISTURE IS PROGGED TO INCREASE SLIGHTLY TODAY...JUST ENOUGH FOR A FEW MORE FAIR WEATHER CUMULUS BUT STILL A SUNNY DAY. TOOK YESTERDAYS HIGH TEMPERATURES AND ADDED A DEGREE TO MOST SITES FOR THE FORECAST MAX. THE GRADIENT IS LIGHT ENOUGH AGAIN FOR A LAKE BREEZE...ESPECIALLY FROM AROUND CLEVELAND EAST...SO TEMPS WILL DROP BACK A COUPLE OF DEGREES AT THE LAKESHORE THIS AFTERNOON. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... THE MODELS CONTINUE TO SHOW THE INITIAL BATCH OF SHOWERS/STORMS MAKING A RUN FOR THE FORECAST AREA ON FRIDAY OUT AHEAD OF THE COLD FRONT. THE AIR MASS WILL BE RELATIVELY DRY AND STABLE BUT THERE WILL LIKELY BE ENOUGH ELEVATED INSTABILITY TO ALLOW THE SHOWERS TO SURVIVE AS THEY CROSS MICHIGAN AND SPREAD ACROSS THE TOLEDO AREA AND WESTERN LAKE ERIE. NOT SURE IF IT WILL BE A FEW SPRINKLES...A FEW HUNDREDTHS... OR RESPECTABLE SHOWERS. WILL HAVE A CHANCE OF SHOWERS/STORMS MAINLY FOR NORTHWEST OHIO BUT CANNOT RULE OUT A SHOWER/SPRINKLES SNEAKING ACROSS THE NORTHERN COUNTIES ON FRIDAY. STILL SOME TIMING DIFFERENCES AMONG MODELS ON SATURDAY WITH THE COLD FRONTAL PASSAGE BUT THE GFS AND ECMWF ARE IN RELATIVE AGREEMENT AND USED THEIR TIMING. NOT OVERLY EXCITED ABOUT THUNDERSTORMS...THE MID LEVEL LAPSE RATES ARE WEAK...BUT THERE IS MODERATE SHEAR AND SOME LOW LEVEL CAPE. WE WILL PROBABLY END UP WITH A FEW THUNDERSTORMS. IT WILL PROBABLY BE A BREEZY DAY AHEAD OF THE FRONT. TEMPS ARE TRICKY ON SATURDAY DEPENDING ON HOW FAST THE CLOUDS AND SHOWERS MOVE EAST. THE FORECAST ASSUMES THERE IS TIME FOR WARMING FOR NE OH/NW PA WITH HIGHS AROUND 80/LOWER 80S. HIGH PRESSURE WILL BUILD IN FROM THE WEST ON SUNDAY. THE NORTHEAST ANTICYCLONIC FLOW AND SUBSIDENCE SHOULD PROVIDE FOR PARTIAL CLEARING ALTHOUGH SOME HIGH CLOUDS MAY LINGER. COOLER...FEELING MORE LIKE FALL...WITH HIGHS FROM THE MID 60S TO LOWER 70S. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... IT WILL BE PREDOMINATELY DRY THROUGH THE FIRST HALF OF THE WORK WEEK...BUT AN UPPER TROUGH AND SOME MOISTURE FEEDING INTO THE REGION MAY BE ENOUGH FOR A FEW SHOWERS. GFS AND CANADIAN SIMILAR IN KEEPING US DRY. THE ECMWF IS ON THE OTHER EXTREME AND PAINTS OUT QPF. FEEL IT WILL BE HARD TO GET TOO DEEP OF MOISTURE INTO THE AREA WITH THE SURFACE HIGH SITTING TO OUR NORTH. WILL HAVE SILENT 20 PERCENT PRECIP CHANCES ACROSS THE EASTERN HALF OF THE AREA TUESDAY AND WEDNESDAY. TEMPERATURES REAL CLOSE TO NORMAL AND GUIDANCE TEMPS CLUSTERED TOGETHER. TEMPS AROUND 70 ON MONDAY INCHING UP TO THE LOWER 70S FOR WEDNESDAY. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... HIGH PRESSURE DRIFTS A LITTLE FURTHER EASTWARD TODAY ALLOWING US TO PICK UP A MORE OF A BREEZE THIS AFTERNOON. SOUTHERLY WINDS MAY GUST AROUND 15 KNOTS ACROSS THE WEST. VFR CONDITIONS CONTINUE. TODAY MAY FEATURE A FEW CUMULUS DOTTING THE SKY. LAKE BREEZE WILL OCCUR AT KERI. LESS CONFIDENT WITH CLE AND THE LAKE BREEZE. IT PUSHED THROUGH ON WEDNESDAY...BUT IT LOOKS REAL CLOSE FOR TODAY TOO. SOME MID AND HIGH CLOUDS ENTER THE PICTURE FROM THE WEST TOWARD THE END OF THE TAF PERIOD. OUTLOOK...NON-VFR POSSIBLE WITH SHOWERS AND A CHANCE OF THUNDERSTORMS FRI NIGHT INTO SAT NIGHT. && .MARINE... HIGH PRESSURE IS INCHING EASTWARD...ENOUGH NOW TO GIVE A SOUTHWEST BREEZE TODAY THROUGH FRIDAY. STILL EXPECT A LAKE BREEZE/ONSHORE FLOW TO DEVELOP FOR THE EASTERN HALF OF THE NEARSHORE WATERS TODAY...LESS SO FOR FRIDAY. THE LATEST TIMING TAKES A COLD FRONT ACROSS THE LAKE DURING THE DAYLIGHT HOURS ON SATURDAY. MOST OF THE GUIDANCE IS CLUSTERED THERE. WHAT IS ALSO FAIRLY WELL AGREED UPON NOW IS THERE WILL BE SOME WIND BEHIND THE FRONT FOR A TIME BEFORE THE HIGH BUILDS IN SUFFICIENTLY TO CALM THINGS DOWN. A SMALL CRAFT ADVISORY IS LIKELY LATE SATURDAY INTO SUNDAY. WITH HIGH PRESSURE SITTING NORTH OF THE LAKE ON MONDAY...WILL KEEP A LIGHT NORTHEAST FLOW GOING. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...KOSARIK NEAR TERM...TK/KOSARIK SHORT TERM...KOSARIK LONG TERM...OUDEMAN AVIATION...OUDEMAN MARINE...OUDEMAN
AREA FORECAST DISCUSSION...UPDATED
NWS PENDLETON OR
1044 PM PDT WED SEP 16 2015 UPDATED AVIATION DISCUSSION .UPDATE...A WEAK WAVE IS MOVING ACROSS THE EASTERN PART OF THE AREA AND SHOULD EXIT IN THE NEXT FEW HOURS. THIS WAVE HAS BROUGHT VERY MODEST AMOUNTS OF RAIN IN SOME LOCATIONS...UP TO A COUPLE OF HUNDREDTHS OF AN INCH AT MOST, WHILE MUCH OF THE AREA REMAINED DRY. SATELLITE IMAGERY SHOW ANOTHER STRONGER WAVE MOVING SOUTH ALONG THE NORTHERN WASHINGTON AREA AND SHOULD ARRIVE IN OUR AREA LATER NIGHT AND TOMORROW MORNING WITH MORE GENEROUS AMOUNTS OF RAIN LIKELY. CONSIDERED DROPPING POPS THROUGH MIDNIGHT BUT THE SHORT RANGE HRRR MODEL SHOWS AN INCREASE IN ACTIVITY IN THE NEXT FEW HOURS IN CENTRAL OREGON AND THEN MOVING THROUGH THE AREA, SO LEFT POPS AS IS. RADAR DOES SHOW A SLOW GENERAL UPWARD TREND IN THE SHOWER ACTIVITY. MADE SOME WIND ADJUSTMENTS THROUGH THE REST OF THE NIGHT BUT NOTHING VERY SIGNIFICANT. ALSO MADE A FEW TEMPERATURE ADJUSTMENTS UPWARD DUE TO THE HEAVY CLOUD COVER AND SLIGHTLY STRONGER WINDS. FORECAST UPDATE ALREADY OUT. PERRY && .AVIATION...06Z TAFS...VFR CONDITIONS WILL BE PREVALENT FOR THE NEXT 24 HOURS. ONE WAVE IS EXITING THE AREA WITH LIGHT SHOWERS OVER THE EASTERN PORTIONS OF THE AREA. ANOTHER WAVE IS POISED TO MOVE INTO THE AREA IN THE NEXT FEW HOURS WITH STRATIFORM RAIN INCREASING FROM CENTRAL OREGON NORTHEAST ACROSS THE AREA FROM 07Z TO 12Z. RAIN WILL BE MODERATE AT TIMES AND MVFR CEILINGS AND VISIBILITIES WILL BE POSSIBLE AT ALL TAF SITES, ESPECIALLY KDLS AND KBDN. RAIN WILL TAPER OFF AND END FROM 16Z TO 20Z. SKIES WILL BE BROKEN TO OVERCAST AT 4000-8000 FEET THROUGH 00Z THEN BECOMING SCATTERED TO BROKEN ABOVE 6000 FEET AFTER THAT. WINDS WILL REMAIN BELOW 15 KTS TONIGHT THEN INCREASE TO 10 TO 20 KTS WITH HIGHER GUSTS FROM 16Z-03Z. WINDS WILL DROP BELOW 12 KTS AFTER 03Z. PERRY && .PREV DISCUSSION... /ISSUED 415 PM PDT WED SEP 16 2015/ SHORT TERM...TONIGHT THROUGH SATURDAY...A BROAD AND DEEP UPPER LEVEL TROUGH REMAINS OVER THE WESTERN US. THERE ARE A COUPLE OF SHORTWAVES IN THE PATTERN THAT WILL IMPACT THE AREA. THE FIRST IS COMING INTO SOUTHWEST OREGON THAT WILL SPREAD SOME PRECIPITATION INTO CENTRAL OREGON LATE TODAY AND THEN OVER THE REST OF THE FORECAST AREA OVERNIGHT. THE SECOND IS SLIDING DOWN THE COAST OF BRITISH COLUMBIA AND WILL MOVE ACROSS THE FORECAST AREA ON THURSDAY KEEPING US UNDER A HIGH THREAT OF PRECIPITATION. PRECIPITATION AMOUNTS WILL RANGE FROM A HALF INCH OR MORE IN THE MOUNTAINS TO A TENTH TO ONE QUARTER OF AN INCH IN THE BASIN THROUGH THURSDAY EVENING. FOLLOWING THE PASSAGE OF THIS SECOND SYSTEM WITH WEATHER PATTERN WILL CHANGE. THE TROUGH OVER THE REGION NOW WILL MOVE OFF TO THE EAST PLACING US UNDER A DRY WESTERLY FLOW THROUGH SATURDAY. WE WILL SEE TEMPERATURES BEGIN TO WARM ON FRIDAY AND SATURDAY. LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY AFTERNOON...A MID/UPPER LEVEL SHORT WAVE WILL BRING INCREASING MOISTURE ALONG THE EAST SLOPES OF THE CENTRAL WASHINGTON CASCADE SATURDAY NIGHT THUS INTRODUCING A LOW CHANCE OF SHOWERS NEAR THE WASHINGTON CASCADE CRESTS SATURDAY NIGHT INTO SUNDAY MORNING. THE SHORT WAVE PUSHES A COLD FRONT THROUGH THE REGION ON MONDAY. THE SHORT WAVE AND COLD FRONT WILL GIVE THE EAST SLOPES OF THE WASHINGTON CASCADES SHOWERS LIKELY MONDAY AFTERNOON AND MONDAY EVENING AND JUST A SLIGHT CHANCE OF SHOWERS ALONG THE EAST SLOPES OF THE CENTRAL AND NORTHERN OREGON CASCADES AND IN THE NORTHERN BLUE MOUNTAINS AND THE WALLOWA MOUNTAINS ON MONDAY. OTHERWISE, FLOW ALOFT ASSOCIATED WITH THE SHORT WAVE WILL BE WESTERLY THUS PRODUCING DOWNSLOPE WINDS AND SINKING AIR MOTION FOR DRY CONDITIONS ELSEWHERE IN FORECAST AREA FOR A DRY COLD FRONT AT LOWER ELEVATIONS. THE SHORT WAVE WILL EXIT THE REGION LATE MONDAY NIGHT WITH AN UPSTREAM FLAT RIDGE OF HIGH PRESSURE MOVING INTO THE PACIFIC NORTHWEST FOR TUESDAY THROUGH WEDNESDAY FOR DRY CONDITIONS PERSISTING THROUGH THE EXTENDED PERIOD. POLAN && .PRELIMINARY POINT TEMPS/POPS... PDT 51 65 47 72 / 60 70 10 0 ALW 54 67 50 74 / 60 70 20 0 PSC 53 71 49 77 / 60 70 10 0 YKM 45 68 43 75 / 60 70 10 0 HRI 53 69 48 75 / 60 70 10 0 ELN 44 66 42 73 / 60 70 10 10 RDM 39 61 38 73 / 60 70 10 0 LGD 44 59 42 69 / 60 80 20 10 GCD 44 62 40 73 / 70 90 10 0 DLS 52 70 50 77 / 60 70 10 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON $$ 83/99/83
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1033 PM EDT FRI SEP 18 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN PLACE THROUGH TOMORROW. A COLD FRONT WILL MOVE INTO THE CAROLINAS FROM THE NORTH ON SUNDAY WITH PRECIPITATION CHANCES INCREASING FOR SUNDAY AND MONDAY. COOLER TEMPERATURES WILL ALSO RETURN ON MONDAY...WITH PERIODIC CHANCES FOR PRECIPITATION CONTINUING INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 1030 PM...ANOTHER CLEAR NIGHT ACROSS THE FORECAST AREA AS DRY SURFACE RIDGE REMAINS THE DOMINANT SYNOPTIC SCALE FEATURE ACROSS THE AREA. SLOWLY BUT SURELY INCREASING DEWPOINTS/LOW LEVEL THICKNESS VALUES SHOULD YIELD MIN TEMPS ABOUT A DEGREE WARMER THAN FRIDAY MORNING...OR WITHIN A DEGREE OR SO OF CLIMO. OTHERWISE...FOG/LOW STRATUS SHOULD DEVELOP/EXPAND ACROSS THE LITTLE TENN VALLEY AND ADJACENT DRAINAGES OVER THE NEXT COUPLE OF HOURS...BUT REMAIN SPORADIC ACROSS MOST OF THE OTHER MAJOR VALLEYS. AS OF 735 PM...DEWPOINTS MIXED OUT A BIT THIS AFTERNOON...SO ITS ANOTHER DECENT LATE SUMMER EVENING ACROSS THE FORECAST AREA...WITH LITTLE IN THE WAY OF CLOUD COVER NOW THAT AFTERNOON CU HAS MOSTLY DISSIPATED. TEMPS SHOULD BE IN THE 60S ACROSS MUCH OF THE AREA BY MIDNIGHT. AS OF 230 PM EDT...THE 500 MB RIDGE AXIS OVER THE SRN APPALACHIANS TONIGHT WILL SLOWLY BREAK DOWN FROM THE NORTHWEST ON SATURDAY AS THE NORTHERN TIER BELT OF WESTERLIES SPREADS SOUTHWARD. THE SURFACE HIGH OVER THE FORECAST AREA WILL GET INCREASINGLY PINCHED OVERHEAD BETWEEN LOW PRESSURE OVER THE COASTAL WATERS AND A COLD FRONT APPROACHING FROM THE OH VALLEY. PROFILES OVER OUR AREA WILL STAY RELATIVELY DRY...ALTHOUGH THE NAM AND RAP DO INDICATE PATCHY LOWER STRATUS TRYING TO MAKE A RUN WESTWARD FROM THE COAST INTO THE PIEDMONT OVERNIGHT. MOST CLOUDINESS THROUGH THE PERIOD...HOWEVER... SHOULD BE CONFINED MAINLY TO EARLY MORNING MOUNTAIN VALLEY STRATUS AND THEN A FEW DAYTIME CUMULUS WITH HEATING SATURDAY AFTERNOON. TEMPERATURES WILL CONTINUE TO REBOUND...WITH MINS AT LEAST A CATEGORY ABOVE CLIMO THROUGHOUT OVERNIGHT...AND TWO TO THREE CATEGORIES ABOVE CLIMO FOR MAX TEMPS SATURDAY AFTERNOON. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 245 PM...A DISTURBANCE WILL REMAIN OFF THE CAROLINA COAST THROUGH THE SHORT RANGE...RESULTING IN LITTLE CHANGE TO THE SENSIBLE WEATHER OVER THE CWA. ON SUNDAY...A WEAK COLD FRONT WILL SWEEP FROM THE NORTHWEST...LIKELY REMAINING WEST OF THE FA BY SUNSET. SKY COVER WILL INCREASE ACROSS THE SOUTHERN APPALACHIAN REGION THROUGH THE DAY. LITTLE TO NO INSTABILITY AND NO FORCING SHOULD RESULT IN DRY WEATHER ON SUNDAY. HIGH TEMPERATURES SHOULD RANGE FROM THE L80S WITHIN THE MTN VALLEYS TO THE U80S EAST. THE WEAK COLD FRONT WILL LIKELY HANG OVER THE SOUTHERN APPALACHIANS EARLY MONDAY MORNING. THE CENTER OF SFC HIGH PRESSURE OVER NEW ENGLAND...THE RIDGE OVER THE REGION ON MONDAY. THE GFS INDICATE THAT WEAK 300 K ISENTROPIC LIFT WILL DEVELOP ACROSS THE REGION DURING THE DAYLIGHT HOURS...SUPPORTED BY LLVL SE FLOW. THE COMBINATION OF ISENTROPIC LIFT...LIGHT UPSLOPE FLOW...AND WIDESPREAD WEAK INSTABILITY SHOULD RESULT IN AN EXPANDING AREA OF SHRA/TSRA ON MONDAY. THICK CLOUDS...RAINFALL...AND DEVELOPING NE SFC WINDS WILL FAVOR HIGH TEMPERATURES BELOW THE MOS CONSENSUS. I WILL FORECAST HIGH TEMPERATURES FROM THE L70S WITHIN THE MTN VALLEYS TO THE L80S ACROSS THE LAKELANDS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 210 PM FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON TUESDAY WITH AN UPPER TROF AXIS JUST TO OUR WEST AND UPPER RIDGING OVER THE WESTERN CONUS. OVER THE NEXT COUPLE OF DAYS...THE TROF IS EXPECTED TO SLOWLY MOVE OVER THE FCST AREA AND MORPH INTO A CLOSED UPPER LOW BY LATE WED. THE LONG RANGE MODELS KEEP THE LOW SPINNING OVER THE SE REGION INTO FRI WITH BROAD SCALE UPPER RIDGING SPREADING FARTHER EAST OVER THE SAME PERIOD. IT IS NOTABLE THAT THE LATEST 12Z RUN OF THE GFS DOES TRY TO MAINTAIN THE CLOSED LOW ABOUT 24 TO 48 HRS LONGER THAN THE OLDER RUN OF THE ECWMF. AT THE SFC...CANADIAN HIGH PRESSURE WILL BE SLIDING OFF THE NEW ENGLAND COAST BY EARLY TUES WITH A BROAD LOW CENTERED JUST OFF THE CAROLINA COAST. THE EVOLUTION OF THE SFC PATTERN REMAINS FAIRLY UNCLEAR AT THIS POINT...WITH SIG DIFFERENCES BETWEEN THE LONG RANGE MODELS. THE GFS AND THE CMC KEEP THE LOW JUST OFFSHORE WELL INTO THURS WITH ANOTHER CANADIAN HIGH SLIDING EASTWARD IN THE WAKE OF THE PREVIOUS SFC HIGH. THE LOW EVENTUALLY DISSIPATES OVER THE CWFA BY FRI WITH AN EVEN STRONGER HIGH MAKING ITS WAY SOUTHWARD AND TOWARDS THE GREAT LAKES BY THE END OF THE PERIOD. ON THE OTHER HAND...THE ECMWF MOVES THE LOW UP THE EAST COAST ON TUES AND THEN WELL OFFSHORE BY LATE WED ALL WHILE KEEPING HIGH PRESSURE OVER THE FCST AREA THRU THE ENTIRE PERIOD. AS FOR THE SENSIBLE FCST...MORE WEIGHT HAS BEEN PLACED ON A GFS TYPE SOLUTION WITH THE BEST CHANCES FOR PRECIP DURING THE FIRST DAY OR 2 OF THE PERIOD. TEMPS APPEAR MORE CONSISTENT BETWEEN THE MODELS WITH VALUES WARMING A FEW DEGREES THRU THE MEDIUM RANGE NEARING CLIMATOLOGY VALUES FOR MID/LATE SEPT. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... AT KCLT AND ELSEWHERE...DRY SURFACE RIDGING WILL RESULT IN PERSISTENT LIGHT NE WINDS AND PRIMARILY VFR CONDITIONS THROUGH THE PERIOD. STILL WOULD NOT RULE OUT A BRIEF FLIGHT RESTRICTION AT KAVL AROUND DAYBREAK...BUT VALLEY FOG/LOW STRATUS SHOULD ONCE AGAIN BE LARGELY CONTAINED TO THE VALLEYS WEST OF KAVL. ADDITIONALLY...A BAND OF MVFR CLOUDS MAY MAKE A RUN TOWARD KCLT AROUND SUNRISE. A CIG IS NOT LIKELY...BUT WILL CONTINUE A MENTION OF FEW020 FOR AROUND THIS TIME. OUTLOOK...MORNING MOUNTAIN VALLEY FOG AND LOW STRATUS WILL CONTINUE SAT NIGHT INTO SUNDAY MORNING. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON SUNDAY...AND A DEVELOPING MID LEVEL LOW MAY INCREASE THE CHANCES OF LOW CLOUDS AND RAIN ACROSS THE REGION EARLY TO MIDDLE NEXT WEEK. CONFIDENCE TABLE... 02-08Z 08-14Z 14-20Z 20-00Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 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...JPT NEAR TERM...HG/JDL SHORT TERM...NED LONG TERM...JPT AVIATION...JDL
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
741 PM EDT FRI SEP 18 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN PLACE THROUGH TOMORROW. A COLD FRONT WILL MOVE INTO THE CAROLINAS FROM THE NORTH ON SUNDAY WITH PRECIPITATION CHANCES INCREASING FOR SUNDAY AND MONDAY. COOLER TEMPERATURES WILL ALSO RETURN ON MONDAY...WITH PERIODIC CHANCES FOR PRECIPITATION CONTINUING INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AS OF 735 PM...DEWPOINTS MIXED OUT A BIT THIS AFTERNOON...SO ITS ANOTHER DECENT LATE SUMMER EVENING ACROSS THE FORECAST AREA...WITH LITTLE IN THE WAY OF CLOUD COVER NOW THAT AFTERNOON CU HAS MOSTLY DISSIPATED. TEMPS SHOULD BE IN THE 60S ACROSS MUCH OF THE AREA BY MIDNIGHT. AS OF 230 PM EDT...THE 500 MB RIDGE AXIS OVER THE SRN APPALACHIANS TONIGHT WILL SLOWLY BREAK DOWN FROM THE NORTHWEST ON SATURDAY AS THE NORTHERN TIER BELT OF WESTERLIES SPREADS SOUTHWARD. THE SURFACE HIGH OVER THE FORECAST AREA WILL GET INCREASINGLY PINCHED OVERHEAD BETWEEN LOW PRESSURE OVER THE COASTAL WATERS AND A COLD FRONT APPROACHING FROM THE OH VALLEY. PROFILES OVER OUR AREA WILL STAY RELATIVELY DRY...ALTHOUGH THE NAM AND RAP DO INDICATE PATCHY LOWER STRATUS TRYING TO MAKE A RUN WESTWARD FROM THE COAST INTO THE PIEDMONT OVERNIGHT. MOST CLOUDINESS THROUGH THE PERIOD...HOWEVER... SHOULD BE CONFINED MAINLY TO EARLY MORNING MOUNTAIN VALLEY STRATUS AND THEN A FEW DAYTIME CUMULUS WITH HEATING SATURDAY AFTERNOON. TEMPERATURES WILL CONTINUE TO REBOUND...WITH MINS AT LEAST A CATEGORY ABOVE CLIMO THROUGHOUT OVERNIGHT...AND TWO TO THREE CATEGORIES ABOVE CLIMO FOR MAX TEMPS SATURDAY AFTERNOON. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 245 PM...A DISTURBANCE WILL REMAIN OFF THE CAROLINA COAST THROUGH THE SHORT RANGE...RESULTING IN LITTLE CHANGE TO THE SENSIBLE WEATHER OVER THE CWA. ON SUNDAY...A WEAK COLD FRONT WILL SWEEP FROM THE NORTHWEST...LIKELY REMAINING WEST OF THE FA BY SUNSET. SKY COVER WILL INCREASE ACROSS THE SOUTHERN APPALACHIAN REGION THROUGH THE DAY. LITTLE TO NO INSTABILITY AND NO FORCING SHOULD RESULT IN DRY WEATHER ON SUNDAY. HIGH TEMPERATURES SHOULD RANGE FROM THE L80S WITHIN THE MTN VALLEYS TO THE U80S EAST. THE WEAK COLD FRONT WILL LIKELY HANG OVER THE SOUTHERN APPALACHIANS EARLY MONDAY MORNING. THE CENTER OF SFC HIGH PRESSURE OVER NEW ENGLAND...THE RIDGE OVER THE REGION ON MONDAY. THE GFS INDICATE THAT WEAK 300 K ISENTROPIC LIFT WILL DEVELOP ACROSS THE REGION DURING THE DAYLIGHT HOURS...SUPPORTED BY LLVL SE FLOW. THE COMBINATION OF ISENTROPIC LIFT...LIGHT UPSLOPE FLOW...AND WIDESPREAD WEAK INSTABILITY SHOULD RESULT IN AN EXPANDING AREA OF SHRA/TSRA ON MONDAY. THICK CLOUDS...RAINFALL...AND DEVELOPING NE SFC WINDS WILL FAVOR HIGH TEMPERATURES BELOW THE MOS CONSENSUS. I WILL FORECAST HIGH TEMPERATURES FROM THE L70S WITHIN THE MTN VALLEYS TO THE L80S ACROSS THE LAKELANDS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 210 PM FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON TUESDAY WITH AN UPPER TROF AXIS JUST TO OUR WEST AND UPPER RIDGING OVER THE WESTERN CONUS. OVER THE NEXT COUPLE OF DAYS...THE TROF IS EXPECTED TO SLOWLY MOVE OVER THE FCST AREA AND MORPH INTO A CLOSED UPPER LOW BY LATE WED. THE LONG RANGE MODELS KEEP THE LOW SPINNING OVER THE SE REGION INTO FRI WITH BROAD SCALE UPPER RIDGING SPREADING FARTHER EAST OVER THE SAME PERIOD. IT IS NOTABLE THAT THE LATEST 12Z RUN OF THE GFS DOES TRY TO MAINTAIN THE CLOSED LOW ABOUT 24 TO 48 HRS LONGER THAN THE OLDER RUN OF THE ECWMF. AT THE SFC...CANADIAN HIGH PRESSURE WILL BE SLIDING OFF THE NEW ENGLAND COAST BY EARLY TUES WITH A BROAD LOW CENTERED JUST OFF THE CAROLINA COAST. THE EVOLUTION OF THE SFC PATTERN REMAINS FAIRLY UNCLEAR AT THIS POINT...WITH SIG DIFFERENCES BETWEEN THE LONG RANGE MODELS. THE GFS AND THE CMC KEEP THE LOW JUST OFFSHORE WELL INTO THURS WITH ANOTHER CANADIAN HIGH SLIDING EASTWARD IN THE WAKE OF THE PREVIOUS SFC HIGH. THE LOW EVENTUALLY DISSIPATES OVER THE CWFA BY FRI WITH AN EVEN STRONGER HIGH MAKING ITS WAY SOUTHWARD AND TOWARDS THE GREAT LAKES BY THE END OF THE PERIOD. ON THE OTHER HAND...THE ECMWF MOVES THE LOW UP THE EAST COAST ON TUES AND THEN WELL OFFSHORE BY LATE WED ALL WHILE KEEPING HIGH PRESSURE OVER THE FCST AREA THRU THE ENTIRE PERIOD. AS FOR THE SENSIBLE FCST...MORE WEIGHT HAS BEEN PLACED ON A GFS TYPE SOLUTION WITH THE BEST CHANCES FOR PRECIP DURING THE FIRST DAY OR 2 OF THE PERIOD. TEMPS APPEAR MORE CONSISTENT BETWEEN THE MODELS WITH VALUES WARMING A FEW DEGREES THRU THE MEDIUM RANGE NEARING CLIMATOLOGY VALUES FOR MID/LATE SEPT. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AT KCLT AND ELSEWHERE...DRY SURFACE RIDGING WILL RESULT IN PERSISTENT LIGHT NE WINDS AND PRIMARILY VFR CONDITIONS THROUGH THE PERIOD. STILL WOULD NOT RULE OUT A BRIEF FLIGHT RESTRICTION AT KAVL AROUND DAYBREAK...BUT VALLEY FOG/LOW STRATUS SHOULD ONCE AGAIN BE LARGELY CONTAINED TO THE VALLEYS WEST OF KAVL. ADDITIONALLY...A BAND OF MVFR CLOUDS MAY MAKE A RUN TOWARD KCLT AROUND SUNRISE. A CIG IS NOT LIKELY...BUT WILL CONTINUE A MENTION OF FEW020 FOR AROUND THIS TIME. OUTLOOK...MORNING MOUNTAIN VALLEY FOG AND LOW STRATUS WILL CONTINUE SAT NIGHT INTO SUNDAY MORNING. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON SUNDAY...AND A DEVELOPING MID LEVEL LOW MAY INCREASE THE CHANCES OF LOW CLOUDS AND RAIN ACROSS THE REGION EARLY TO MIDDLE NEXT WEEK. CONFIDENCE TABLE... 23-05Z 05-11Z 11-17Z 17-18Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% MED 61% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 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...JPT NEAR TERM...HG/JDL SHORT TERM...NED LONG TERM...JPT AVIATION...JDL
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1223 PM CDT THU SEP 17 2015 .UPDATE... ISSUED AT 1221 PM CDT THU SEP 17 2015 SEE UPDATED AVIATION DISCUSSION BELOW. UPDATE ISSUED AT 1118 AM CDT THU SEP 17 2015 SURFACE TROF HAS JUST ABOUT CLEARED THE CWA...ALONG WITH THE REMAINING ELEVATED SHOWERS. HAVE INCREASED THE WINDS A TAD...OTHERWISE NO CHANGES TO THE FORECAST AS FOCUS SHIFTS TO TONIGHT/FRIDAYS RAIN POTENTIAL. && .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 334 AM CDT THU SEP 17 2015 COLD FRONT IS MAKING ITS WAY EAST ACROSS THE CWA EARLY THIS MORNING WITH STILL SOME ISO/WDLY SCT LIGHT SHOWERS OVER THE AREA AS WELL. UPSTREAM RADARS STILL SHOW ACTIVITY ALL THE WAY DOWN INTO THE NEBRASKA PANHANDLE...WHICH THE HRRR HAS A DECENT HANDLE ON. HAVE EXTENDED SOME SMALL POPS THROUGH THE MORNING HOURS TO ACCOUNT FOR WHATS YET TO COME FROM THE SOUTHWEST. BY LATER THIS AFTERNOON...DRIER AIR WILL BE WORKING INTO THE AREA WITH BREEZY NORTHWEST WINDS. HIGHS WILL BE COOLER AS 850 MB TEMPS GO DOWNWARD THROUGH THE DAY. SHORTWAVE ENERGY STILL ON TRACK FOR FRIDAY AND MODELS STILL AGREE RATHER WELL IN BRINGING RAINFALL TO WESTERN AND CENTRAL SD TONIGHT AND THROUGH THE DAY FRIDAY. DELAYED THE ONSET OF PRECIP ACROSS CENTRAL SD A BIT AND CUT BACK THE EASTWARD PROGRESSION PRIOR TO 12Z FRIDAY. STILL APPEARS HEAVIEST RAINFALL ACROSS OUR CWA WILL BE ACROSS CENTRAL SD...WITH LESSER AMOUNTS OVER NORTHEAST SD INTO WEST CENTRAL MN. SYSTEM QUICKLY SLIDES EAST OF THE AREA FRIDAY EVENING...MAKING WAY FOR DRIER CONDITIONS AND WARMING TEMPERATURES ON SATURDAY. .LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY) ISSUED AT 334 AM CDT THU SEP 17 2015 SFC HIGH PRESSURE WILL DOMINATE THROUGH THE WEEKEND KEEPING THE FORECAST DRY. A WEAK FRONT WILL APPROACH THE AREA ON MONDAY. WITH SOUTHERLY FLOW AHEAD OF THE FRONT..MONDAY WILL BE THE WARMEST DAY OF THE PERIOD. A BROAD AREA OF LOW PRESSURE WILL DEVELOP ON TUESDAY AS A WARM FRONT NUDGES UP INTO THE EASTERN CWA. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN THE WAA REGIME TUE AFTERNOON THROUGH WED MORNING. GFS ALSO INDICATES STRONG SHORTWAVE ENHANCEMENT BY WED AFTERNOON/EVENING LEADING TO GREATER POTENTIAL OF STRONGER STORMS AND/OR HEAVIER RAIN. ON THE FLIP SIDE...THE ECMWF SHOWS A LOW WITH A WARM FRONT DRAPED OVER THE CWA BUT KEEPS THE REGION CAPPED AND DRY. NEEDLESS TO SAY..STUCK WITH SLIGHT CHANCE TO CHANCE POPS AS GIVEN BY SUPERBLEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON) ISSUED AT 1221 PM CDT THU SEP 17 2015 AN AREA OF MVFR CIGS WILL TRACK ACROSS THE NORTH CENTRAL AND NORTHEASTERN CWA THIS AFTERNOON. OTHERWISE...VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE TAF PERIOD. AN AREA OF RAIN WILL SPREAD FROM WEST TO EAST LATE TONIGHT THROUGH MIDDAY FRIDAY. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...CONNELLY SHORT TERM...TMT LONG TERM...WISE AVIATION...PARKIN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1121 AM CDT THU SEP 17 2015 .UPDATE... ISSUED AT 1118 AM CDT THU SEP 17 2015 SURFACE TROF HAS JUST ABOUT CLEARED THE CWA...ALONG WITH THE REMAINING ELEVATED SHOWERS. HAVE INCREASED THE WINDS A TAD...OTHERWISE NO CHANGES TO THE FORECAST AS FOCUS SHIFTS TO TONIGHT/FRIDAYS RAIN POTENTIAL. && .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 334 AM CDT THU SEP 17 2015 COLD FRONT IS MAKING ITS WAY EAST ACROSS THE CWA EARLY THIS MORNING WITH STILL SOME ISO/WDLY SCT LIGHT SHOWERS OVER THE AREA AS WELL. UPSTREAM RADARS STILL SHOW ACTIVITY ALL THE WAY DOWN INTO THE NEBRASKA PANHANDLE...WHICH THE HRRR HAS A DECENT HANDLE ON. HAVE EXTENDED SOME SMALL POPS THROUGH THE MORNING HOURS TO ACCOUNT FOR WHATS YET TO COME FROM THE SOUTHWEST. BY LATER THIS AFTERNOON...DRIER AIR WILL BE WORKING INTO THE AREA WITH BREEZY NORTHWEST WINDS. HIGHS WILL BE COOLER AS 850 MB TEMPS GO DOWNWARD THROUGH THE DAY. SHORTWAVE ENERGY STILL ON TRACK FOR FRIDAY AND MODELS STILL AGREE RATHER WELL IN BRINGING RAINFALL TO WESTERN AND CENTRAL SD TONIGHT AND THROUGH THE DAY FRIDAY. DELAYED THE ONSET OF PRECIP ACROSS CENTRAL SD A BIT AND CUT BACK THE EASTWARD PROGRESSION PRIOR TO 12Z FRIDAY. STILL APPEARS HEAVIEST RAINFALL ACROSS OUR CWA WILL BE ACROSS CENTRAL SD...WITH LESSER AMOUNTS OVER NORTHEAST SD INTO WEST CENTRAL MN. SYSTEM QUICKLY SLIDES EAST OF THE AREA FRIDAY EVENING...MAKING WAY FOR DRIER CONDITIONS AND WARMING TEMPERATURES ON SATURDAY. .LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY) ISSUED AT 334 AM CDT THU SEP 17 2015 SFC HIGH PRESSURE WILL DOMINATE THROUGH THE WEEKEND KEEPING THE FORECAST DRY. A WEAK FRONT WILL APPROACH THE AREA ON MONDAY. WITH SOUTHERLY FLOW AHEAD OF THE FRONT..MONDAY WILL BE THE WARMEST DAY OF THE PERIOD. A BROAD AREA OF LOW PRESSURE WILL DEVELOP ON TUESDAY AS A WARM FRONT NUDGES UP INTO THE EASTERN CWA. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN THE WAA REGIME TUE AFTERNOON THROUGH WED MORNING. GFS ALSO INDICATES STRONG SHORTWAVE ENHANCEMENT BY WED AFTERNOON/EVENING LEADING TO GREATER POTENTIAL OF STRONGER STORMS AND/OR HEAVIER RAIN. ON THE FLIP SIDE...THE ECMWF SHOWS A LOW WITH A WARM FRONT DRAPED OVER THE CWA BUT KEEPS THE REGION CAPPED AND DRY. NEEDLESS TO SAY..STUCK WITH SLIGHT CHANCE TO CHANCE POPS AS GIVEN BY SUPERBLEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 631 AM CDT THU SEP 17 2015 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NORTHWEST WINDS WILL DIMINISH THIS EVENING AND BECOME LIGHT AND VARIABLE OVERNIGHT. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...CONNELLY SHORT TERM...TMT LONG TERM...WISE AVIATION...WISE
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
632 AM CDT THU SEP 17 2015 .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 334 AM CDT THU SEP 17 2015 COLD FRONT IS MAKING ITS WAY EAST ACROSS THE CWA EARLY THIS MORNING WITH STILL SOME ISO/WDLY SCT LIGHT SHOWERS OVER THE AREA AS WELL. UPSTREAM RADARS STILL SHOW ACTIVITY ALL THE WAY DOWN INTO THE NEBRASKA PANHANDLE...WHICH THE HRRR HAS A DECENT HANDLE ON. HAVE EXTENDED SOME SMALL POPS THROUGH THE MORNING HOURS TO ACCOUNT FOR WHATS YET TO COME FROM THE SOUTHWEST. BY LATER THIS AFTERNOON...DRIER AIR WILL BE WORKING INTO THE AREA WITH BREEZY NORTHWEST WINDS. HIGHS WILL BE COOLER AS 850 MB TEMPS GO DOWNWARD THROUGH THE DAY. SHORTWAVE ENERGY STILL ON TRACK FOR FRIDAY AND MODELS STILL AGREE RATHER WELL IN BRINGING RAINFALL TO WESTERN AND CENTRAL SD TONIGHT AND THROUGH THE DAY FRIDAY. DELAYED THE ONSET OF PRECIP ACROSS CENTRAL SD A BIT AND CUT BACK THE EASTWARD PROGRESSION PRIOR TO 12Z FRIDAY. STILL APPEARS HEAVIEST RAINFALL ACROSS OUR CWA WILL BE ACROSS CENTRAL SD...WITH LESSER AMOUNTS OVER NORTHEAST SD INTO WEST CENTRAL MN. SYSTEM QUICKLY SLIDES EAST OF THE AREA FRIDAY EVENING...MAKING WAY FOR DRIER CONDITIONS AND WARMING TEMPERATURES ON SATURDAY. .LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY) ISSUED AT 334 AM CDT THU SEP 17 2015 SFC HIGH PRESSURE WILL DOMINATE THROUGH THE WEEKEND KEEPING THE FORECAST DRY. A WEAK FRONT WILL APPROACH THE AREA ON MONDAY. WITH SOUTHERLY FLOW AHEAD OF THE FRONT..MONDAY WILL BE THE WARMEST DAY OF THE PERIOD. A BROAD AREA OF LOW PRESSURE WILL DEVELOP ON TUESDAY AS A WARM FRONT NUDGES UP INTO THE EASTERN CWA. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN THE WAA REGIME TUE AFTERNOON THROUGH WED MORNING. GFS ALSO INDICATES STRONG SHORTWAVE ENHANCEMENT BY WED AFTERNOON/EVENING LEADING TO GREATER POTENTIAL OF STRONGER STORMS AND/OR HEAVIER RAIN. ON THE FLIP SIDE...THE ECMWF SHOWS A LOW WITH A WARM FRONT DRAPED OVER THE CWA BUT KEEPS THE REGION CAPPED AND DRY. NEEDLESS TO SAY..STUCK WITH SLIGHT CHANCE TO CHANCE POPS AS GIVEN BY SUPERBLEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT 631 AM CDT THU SEP 17 2015 VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. NORTHWEST WINDS WILL DIMINISH THIS EVENING AND BECOME LIGHT AND VARIABLE OVERNIGHT. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...TMT LONG TERM...WISE AVIATION...WISE
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
334 AM CDT THU SEP 17 2015 .SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON) ISSUED AT 334 AM CDT THU SEP 17 2015 COLD FRONT IS MAKING ITS WAY EAST ACROSS THE CWA EARLY THIS MORNING WITH STILL SOME ISO/WDLY SCT LIGHT SHOWERS OVER THE AREA AS WELL. UPSTREAM RADARS STILL SHOW ACTIVITY ALL THE WAY DOWN INTO THE NEBRASKA PANHANDLE...WHICH THE HRRR HAS A DECENT HANDLE ON. HAVE EXTENDED SOME SMALL POPS THROUGH THE MORNING HOURS TO ACCOUNT FOR WHATS YET TO COME FROM THE SOUTHWEST. BY LATER THIS AFTERNOON...DRIER AIR WILL BE WORKING INTO THE AREA WITH BREEZY NORTHWEST WINDS. HIGHS WILL BE COOLER AS 850 MB TEMPS GO DOWNWARD THROUGH THE DAY. SHORTWAVE ENERGY STILL ON TRACK FOR FRIDAY AND MODELS STILL AGREE RATHER WELL IN BRINGING RAINFALL TO WESTERN AND CENTRAL SD TONIGHT AND THROUGH THE DAY FRIDAY. DELAYED THE ONSET OF PRECIP ACROSS CENTRAL SD A BIT AND CUT BACK THE EASTWARD PROGRESSION PRIOR TO 12Z FRIDAY. STILL APPEARS HEAVIEST RAINFALL ACROSS OUR CWA WILL BE ACROSS CENTRAL SD...WITH LESSER AMOUNTS OVER NORTHEAST SD INTO WEST CENTRAL MN. SYSTEM QUICKLY SLIDES EAST OF THE AREA FRIDAY EVENING...MAKING WAY FOR DRIER CONDITIONS AND WARMING TEMPERATURES ON SATURDAY. .LONG TERM...(SATURDAY EVENING THROUGH WEDNESDAY) ISSUED AT 334 AM CDT THU SEP 17 2015 SFC HIGH PRESSURE WILL DOMINATE THROUGH THE WEEKEND KEEPING THE FORECAST DRY. A WEAK FRONT WILL APPROACH THE AREA ON MONDAY. WITH SOUTHERLY FLOW AHEAD OF THE FRONT..MONDAY WILL BE THE WARMEST DAY OF THE PERIOD. A BROAD AREA OF LOW PRESSURE WILL DEVELOP ON TUESDAY AS A WARM FRONT NUDGES UP INTO THE EASTERN CWA. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN THE WAA REGIME TUE AFTERNOON THROUGH WED MORNING. GFS ALSO INDICATES STRONG SHORTWAVE ENHANCEMENT BY WED AFTERNOON/EVENING LEADING TO GREATER POTENTIAL OF STRONGER STORMS AND/OR HEAVIER RAIN. ON THE FLIP SIDE...THE ECMWF SHOWS A LOW WITH A WARM FRONT DRAPED OVER THE CWA BUT KEEPS THE REGION CAPPED AND DRY. NEEDLESS TO SAY..STUCK WITH SLIGHT CHANCE TO CHANCE POPS AS GIVEN BY SUPERBLEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1223 AM CDT THU SEP 17 2015 VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE DAY THURSDAY. THERE WILL ALSO BE SCATTERED SHOWERS AND THUNDERSTORMS MOVING ACROSS THE REGION TONIGHT AND INTO THE MORNING ON THURSDAY. ISOLATED STRONG WIND GUSTS TO 50 KTS ARE POSSIBLE WITH THESE STORMS. LOOK FOR SOUTH/SOUTHEASTERLY WINDS TO SHIFT TO THE NORTHWEST AND INCREASE INTO THE 15 TO 30 KT RANGE THURSDAY MORNING. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ SHORT TERM...TMT LONG TERM...WISE AVIATION...WISE
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1231 AM CDT THU SEP 17 2015 .UPDATE... ISSUED AT 1228 AM CDT THU SEP 17 2015 BROKEN LINE OF SHOWERS AND STORMS MOVING EASTWARD ACROSS CENTRAL SD AND WILL BE INTO THE JAMES VALLEY SOON. SOME OF THE STRONGER CORES ARE PRODUCING GUSTS OVER 50 MPH AND EVEN A 60 MPH GUST AT PRESHO. ALSO SEEING A FEW WEAK HEAT BURSTS WITH TEMP RISES FROM 5 TO 10 DEGREES. HAVE UPDATED POPS TO INCREASE PRECIP CHANCES THROUGH THE NIGHT AS THIS ACTIVITY MOVES EASTWARD. HRRR SEEMS TO HAVE A GOOD HANDLE ON THIS. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 314 PM CDT WED SEP 16 2015 WEAK CONVECTION OVER CLEAR LAKE WILL CONTINUE TO PUSH OFF INTO MINNESOTA THIS AFTERNOON. HRRR SHOWS ADDITIONAL WEAK/SCATTERED REDEVELOPMENT...THE DISORGANIZATION LIKELY OWING TO A LACK OF STRONG FORCING ALOFT. THIS AREA MAY EXPERIENCE SOME ADDITIONAL MORE ORGANIZED ELEVATED CONVECTION AS A LOW LEVEL JET DEVELOPS THIS EVENING...HOWEVER THE MAIN FOCUS OF THE JET WILL SHIFT EAST OF THE CWA. A WAVE ALOFT WILL PROVIDE FOR INCREASING MID LEVEL MOISTURE WEST RIVER...SHIFTING EAST OVERNIGHT. SOUNDINGS ARE DRY BELOW 10KFT...WITH VERY LIMITED INSTABILITY ALOFT...SUGGESTING SCATTERED VERY LIGHT SHOWERS WITH THE OCCASIONAL LIGHTING STRIKE. CANADIAN HIGH PRESSURE NOSING INTO THE CWA THURSDAY WILL ALLOW FOR MORE AVERAGE DAYTIME TEMPERATURES. MODELS CONTINUE TO GENERATE A RATHER PROMINENT QPF BULLSEYE WEST RIVER INTO CENTRAL COUNTIES FRIDAY IN THE VICINITY OF AN INVERTED TROF...WITH FAVORABLE PLACEMENT OF A SHARED ENERGY AREA AND Q VECTOR BULLSEYE. TO THE EAST...WE WILL SEE A DRY NORTHEAST FETCH...WHICH WILL LIMIT QPF/POPS. 850MB TEMPERATURES WILL HAVE BOTTOMED OUT AROUND +5C BY THAT POINT...SO ANTICIPATE MUCH OF THE FORECAST AREA WILL STRUGGLE TO TOP 60F. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 314 PM CDT WED SEP 16 2015 HIGH PRESSURE WILL BE CENTERED OVER NEBRASKA WHEN THE PERIOD BEGINS...THEN GETS QUICKLY PUSHED EASTWARD AHEAD OF AN APPROACHING TROUGH SATURDAY NIGHT. THE TROUGH/FRONT WILL SLOWLY STRENGTHEN AND LOOKS TO FINALLY TRACK ACROSS THE CWA TUESDAY AND WEDNESDAY...BECOMING THE FOCUS FOR POTENTIAL PRECIPITATION. BEST CHANCES WILL BE ACROSS THE EASTERN PART OF THE CWA WHERE SOME INSTABILITY IS NOTED IN THE MODELS. NOT MUCH IN THE WAY OF UPPER LEVEL ENERGY...SO WILL KEEP POPS LOW FOR THE TIME BEING. WILL SEE A GRADUAL WARMING TREND DURING THE FIRST HALF OF THE PERIOD WITH HIGHS IN THE UPPER 60S AND LOWER 70S SATURDAY...MAINLY IN THE 70S ON SUNDAY...AND IN THE UPPER 70S TO MID 80S MONDAY. HIGHS IN THE 70S TO AROUND 80 WILL BE COMMON TUESDAY AND WEDNESDAY...DEPENDING ON CLOUD COVER AND POSSIBLE PRECIPITATION. OVERNIGHT LOWS WILL BE IN THE UPPER 40S TO MID 50S THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1223 AM CDT THU SEP 17 2015 VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE DAY THURSDAY. THERE WILL ALSO BE SCATTERED SHOWERS AND THUNDERSTORMS MOVING ACROSS THE REGION TONIGHT AND INTO THE MORNING ON THURSDAY. ISOLATED STRONG WIND GUSTS TO 50 KTS ARE POSSIBLE WITH THESE STORMS. LOOK FOR SOUTH/SOUTHEASTERLY WINDS TO SHIFT TO THE NORTHWEST AND INCREASE INTO THE 15 TO 30 KT RANGE THURSDAY MORNING. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...TMT SHORT TERM...CONNELLY LONG TERM...PARKIN AVIATION...WISE
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1225 AM CDT THU SEP 17 2015 .UPDATE... ISSUED AT 1032 PM CDT WED SEP 16 2015 NO CHANGES PLANNED. FORECAST ON TRACK. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 314 PM CDT WED SEP 16 2015 WEAK CONVECTION OVER CLEAR LAKE WILL CONTINUE TO PUSH OFF INTO MINNESOTA THIS AFTERNOON. HRRR SHOWS ADDITIONAL WEAK/SCATTERED REDEVELOPMENT...THE DISORGANIZATION LIKELY OWING TO A LACK OF STRONG FORCING ALOFT. THIS AREA MAY EXPERIENCE SOME ADDITIONAL MORE ORGANIZED ELEVATED CONVECTION AS A LOW LEVEL JET DEVELOPS THIS EVENING...HOWEVER THE MAIN FOCUS OF THE JET WILL SHIFT EAST OF THE CWA. A WAVE ALOFT WILL PROVIDE FOR INCREASING MID LEVEL MOISTURE WEST RIVER...SHIFTING EAST OVERNIGHT. SOUNDINGS ARE DRY BELOW 10KFT...WITH VERY LIMITED INSTABILITY ALOFT...SUGGESTING SCATTERED VERY LIGHT SHOWERS WITH THE OCCASIONAL LIGHTING STRIKE. CANADIAN HIGH PRESSURE NOSING INTO THE CWA THURSDAY WILL ALLOW FOR MORE AVERAGE DAYTIME TEMPERATURES. MODELS CONTINUE TO GENERATE A RATHER PROMINENT QPF BULLSEYE WEST RIVER INTO CENTRAL COUNTIES FRIDAY IN THE VICINITY OF AN INVERTED TROF...WITH FAVORABLE PLACEMENT OF A SHARED ENERGY AREA AND Q VECTOR BULLSEYE. TO THE EAST...WE WILL SEE A DRY NORTHEAST FETCH...WHICH WILL LIMIT QPF/POPS. 850MB TEMPERATURES WILL HAVE BOTTOMED OUT AROUND +5C BY THAT POINT...SO ANTICIPATE MUCH OF THE FORECAST AREA WILL STRUGGLE TO TOP 60F. .LONG TERM...(SATURDAY THROUGH WEDNESDAY) ISSUED AT 314 PM CDT WED SEP 16 2015 HIGH PRESSURE WILL BE CENTERED OVER NEBRASKA WHEN THE PERIOD BEGINS...THEN GETS QUICKLY PUSHED EASTWARD AHEAD OF AN APPROACHING TROUGH SATURDAY NIGHT. THE TROUGH/FRONT WILL SLOWLY STRENGTHEN AND LOOKS TO FINALLY TRACK ACROSS THE CWA TUESDAY AND WEDNESDAY...BECOMING THE FOCUS FOR POTENTIAL PRECIPITATION. BEST CHANCES WILL BE ACROSS THE EASTERN PART OF THE CWA WHERE SOME INSTABILITY IS NOTED IN THE MODELS. NOT MUCH IN THE WAY OF UPPER LEVEL ENERGY...SO WILL KEEP POPS LOW FOR THE TIME BEING. WILL SEE A GRADUAL WARMING TREND DURING THE FIRST HALF OF THE PERIOD WITH HIGHS IN THE UPPER 60S AND LOWER 70S SATURDAY...MAINLY IN THE 70S ON SUNDAY...AND IN THE UPPER 70S TO MID 80S MONDAY. HIGHS IN THE 70S TO AROUND 80 WILL BE COMMON TUESDAY AND WEDNESDAY...DEPENDING ON CLOUD COVER AND POSSIBLE PRECIPITATION. OVERNIGHT LOWS WILL BE IN THE UPPER 40S TO MID 50S THROUGH THE PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT 1223 AM CDT THU SEP 17 2015 VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE DAY THURSDAY. THERE WILL ALSO BE SCATTERED SHOWERS AND THUNDERSTORMS MOVING ACROSS THE REGION TONIGHT AND INTO THE MORNING ON THURSDAY. ISOLATED STRONG WIND GUSTS TO 50 KTS ARE POSSIBLE WITH THESE STORMS. LOOK FOR SOUTH/SOUTHEASTERLY WINDS TO SHIFT TO THE NORTHWEST AND INCREASE INTO THE 15 TO 30 KT RANGE THURSDAY MORNING. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ UPDATE...DORN SHORT TERM...CONNELLY LONG TERM...PARKIN AVIATION...WISE
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1150 AM CDT THU SEP 17 2015 .DISCUSSION...HIGH PRESSURE REMAINS IN CONTROL OF OUR WEATHER, AND OUR DRY FORECAST FOR TODAY LOOKS TO BE ON TRACK, AS DOES CURRENT TEMP FORECAST. LOW LEVEL MOISTURE WORKING NORTHEASTWARD OUT OF ALABAMA IS PRODUCING A CU FIELD OF NOTE, AND CSV DEVELOPED A 4K FT CIG AT 16Z. WILL THEREFORE INCREASE CU COVERAGE IN OUR FCST GRIDS FOR SRN AND ERN AREAS FOR THIS AFTERNOON. LATEST HRRR PRECIP FCST FOR TODAY GIVES A VERY WEAK INDICATION OF ISOLATED SHOWER DEVELOPMENT OVER THE SOUTH, BUT BLV SUBSIDENCE INVERSION NEAR 780MB AND PREVAILING DRYNESS OF ATMOSPHERIC COLUMN WILL BE STRONG ENOUGH TO KEEP SHOWERS AT BAY. ALTHOUGH CHANGES TO GRIDS ARE MINOR, WILL GO AHEAD AND SEND OUT A NEW SUITE OF PRODUCTS TO REFLECT LATEST DIURNAL TRENDS AND EXPECTATIONS. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 87 62 88 64 / 0 0 10 10 CLARKSVILLE 86 61 87 65 / 0 0 10 10 CROSSVILLE 80 56 81 59 / 0 0 10 10 COLUMBIA 86 59 87 62 / 0 0 10 10 LAWRENCEBURG 85 60 86 62 / 0 0 10 10 WAVERLY 86 61 86 64 / 0 0 10 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 19
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
246 PM CDT THU SEP 17 2015 .SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)... ONLY HIGHLIGHT IN THE SHORT TERM PERIOD WILL BE THE POSSIBILITY OF LOCALIZED DENSE FOG FRIDAY MORNING FOR THE COASTAL PLAINS AND EASTERN COUNTIES. RAIN CHANCES WILL CONTINUE TO BE LOW WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. THE SYNOPTIC PATTERN REVEALS AN H5 RIDGE CENTERED OVER TEXAS WITH A LONGWAVE TROUGH SHIFTING ACROSS THE NORTHERN ROCKIES WHILE ANOTHER TROUGH IS LOCATED OVER FLORIDA. THE RIDGE OVER TEXAS WILL CONTINUE TO BEAR ITS INFLUENCE AND PERPETUATE THE SLIGHTLY ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS. ONLY CAVEAT WILL BE ISOLATED LIGHT SHOWERS ACROSS PORTIONS OF THE COASTAL PLAINS BUT HAVE ONLY MENTIONED A 15% CHANCE IN THAT LOCATION THIS AFTERNOON. THESE SHOWERS WILL DISSIPATE QUICKLY AFTER SUNSET. LOW CLOUDS WILL DEVELOP ONCE AGAIN OVERNIGHT WITH ANOTHER LIKELY ROUND OF FOG IN THE EASTERN AND COASTAL PLAIN COUNTIES. DEWPOINT DEPRESSIONS WILL BE 1F OR LESS PER RAP OUTPUT WITH NEAR CALM WINDS. SREF PROBABILITIES OF <1 MILE VISIBILITIES ARE HIGHER THEN WHAT IT INDICATED FOR THIS MORNING ALSO. AREAS OF FOG WERE ADDED TO THE WEATHER FORECAST WITH THE DEVELOPMENT OF DENSE FOG NEEDING TO BE CLOSELY MONITORED. THE LOW CLOUDS AND FOG THAT DO FROM WILL DISSIPATE OUT THROUGH THE MID TO LATE MORNING...SIMILAR TO TODAY. ADDITIONAL CLEARING WILL OCCUR THROUGH THE AFTERNOON HOURS FRIDAY WITH TEMPERATURES REACHING BACK INTO THE MID TO UPPER 90S. && .LONG TERM (SATURDAY THROUGH THURSDAY)... THE LONG TERM FORECAST WILL CONTINUE TO BE MAINLY DOMINATED BY AN UPPER LEVEL RIDGE. A QUICKLY MOVING TROUGH WILL PASS NORTH OF THE RIDGE...ACROSS THE NORTHERN PLAINS FRIDAY AFTERNOON. THIS UPPER LOW WILL ALLOW A COLD FRONT TO MOVE INTO NORTH TEXAS SATURDAY AFTERNOON. HOWEVER...WITH THE RIDGE IN PLACE ACROSS SOUTHERN AND CENTRAL TEXAS...THE FRONT SHOULD STALL SOMEWHERE NEAR THE I-20 CORRIDOR. THE GFS/ECMWF BOTH ARE SHOWING SOME AFTERNOON AND EVENING CONVECTION ALONG THE FRONT SATURDAY...BUT MOST IF NOT ALL OF THIS SHOULD STAY TO OUR NORTH CLOSER TO THE FRONT AND WILL NOT MENTION ANY PRECIP AT THIS TIME FOR THE NORTHERN HILL COUNTRY. FOR THE REST OF THE EXTENDED FORECAST...MODELS ARE PROGGING SURFACE DEWPOINTS TO LOWER INTO THE 50S AND LOWER 60S BY SATURDAY AFTERNOON...CONTINUING EACH AFTERNOON THROUGH THE REST OF THE PERIOD. HIGH TEMPERATURES WILL BE IN THE LOWER TO MIDDLE 90S WITH PLEASANT...DRY EVENINGS. LOW TEMPERATURES WILL UPPER 60S TO LOWER 70S ACROSS THE AREA. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 73 95 72 95 71 / 0 - 0 - - AUSTIN BERGSTROM INTL AIRPORT 71 95 70 94 68 / 0 - 0 - - NEW BRAUNFELS MUNI AIRPORT 73 96 72 96 69 / 0 - 0 - - BURNET MUNI AIRPORT 72 94 71 94 69 / 0 0 0 10 - DEL RIO INTL AIRPORT 75 97 76 96 73 / 0 0 0 - - GEORGETOWN MUNI AIRPORT 73 95 71 94 70 / 0 0 0 - - HONDO MUNI AIRPORT 73 96 72 96 68 / 0 0 0 - - SAN MARCOS MUNI AIRPORT 73 94 72 93 69 / 0 - 0 - - LA GRANGE - FAYETTE REGIONAL 73 94 71 93 70 / - - 0 - - SAN ANTONIO INTL AIRPORT 75 95 74 95 71 / 0 0 0 - - STINSON MUNI AIRPORT 75 96 74 96 71 / 0 - 0 - - && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT-TERM...ALLEN LONG-TERM...HAMPSHIRE PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
613 AM CDT THU SEP 17 2015 .AVIATION... /12Z TAFS/ Early this morning, stratus with ceilings around 2000 feet persist at all terminals except KABI and KBBD. The morning stratus will lift after 14z, with VFR conditions expected area-wide for the remainder of the TAF period. Gusty south winds in the 20 to 25 knot range will also develop by late morning/early afternoon before subsiding after sunset. && .PREV DISCUSSION... /ISSUED 328 AM CDT THU SEP 17 2015/ SHORT TERM... (Today and Tonight) Very little change today from what we experienced yesterday. The upper level ridge will remain parked over the area, and may strengthen just a tad. 850mb temperatures also warm a degree or so, so have gone with highs of a degree or two warmer generally. Low clouds have already begun making their way into the Concho Valley early this morning, and so we will likely see another day with a field of stratocumulus or cumulus clouds across much of the area. The HRRR tries to produce a few showers in our southeastern counties, but with the upper level high strengthening a bit, there shouldn`t be enough coverage to mention anything in the forecast, if they even develop. We will see another mild night with lows in the upper 60s to lower 70s and southerly winds of 5 to 15 mph. 20 LONG TERM... (Friday through Wednesday) Above normal temperatures are forecast across West Central Texas on Friday as an upper level ridge remains centered across Central Texas. Highs will generally be in the mid to upper 90s, with overnight lows mainly in the lower 70s. An upper level trough will move across the Plains on Friday, sending a cold front into the northern Big Country Saturday morning. Previous GFS/ECMWF models runs indicated the front stalling south of Interstate 20, across the northern Concho Valley or Heartland. The 00z runs are less aggressive, keeping the front across the Big Country. Although the farther south solution is still possible, PoPs were reduced slightly across much of the region, especially for areas south of Interstate 20. The best chance of showers and thunderstorms looks to be across the northern Big Country. Rain chances will linger into Sunday, mainly across the Big Country, with the remnant front still in the area. Highs this weekend will range from the mid and upper 80s across much of the Big Country, to the upper 80s to lower 90s elsewhere. Upper level ridging will build back across West Central Texas next week. This will result in a return of above normal temperatures and generally dry conditions. Daniels && .PRELIMINARY POINT TEMPS/POPS... Abilene 95 73 96 72 / 0 0 0 20 San Angelo 96 72 97 72 / 0 0 0 5 Junction 94 70 94 71 / 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ Aviation: Doll
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
328 AM CDT THU SEP 17 2015 .SHORT TERM... (Today and Tonight) Very little change today from what we experienced yesterday. The upper level ridge will remain parked over the area, and may strengthen just a tad. 850mb temperatures also warm a degree or so, so have gone with highs of a degree or two warmer generally. Low clouds have already begun making their way into the Concho Valley early this morning, and so we will likely see another day with a field of stratocumulus or cumulus clouds across much of the area. The HRRR tries to produce a few showers in our southeastern counties, but with the upper level high strengthening a bit, there shouldn`t be enough coverage to mention anything in the forecast, if they even develop. We will see another mild night with lows in the upper 60s to lower 70s and southerly winds of 5 to 15 mph. 20 .LONG TERM... (Friday through Wednesday) Above normal temperatures are forecast across West Central Texas on Friday as an upper level ridge remains centered across Central Texas. Highs will generally be in the mid to upper 90s, with overnight lows mainly in the lower 70s. An upper level trough will move across the Plains on Friday, sending a cold front into the northern Big Country Saturday morning. Previous GFS/ECMWF models runs indicated the front stalling south of Interstate 20, across the northern Concho Valley or Heartland. The 00z runs are less aggressive, keeping the front across the Big Country. Although the farther south solution is still possible, PoPs were reduced slightly across much of the region, especially for areas south of Interstate 20. The best chance of showers and thunderstorms looks to be across the northern Big Country. Rain chances will linger into Sunday, mainly across the Big Country, with the remnant front still in the area. Highs this weekend will range from the mid and upper 80s across much of the Big Country, to the upper 80s to lower 90s elsewhere. Upper level ridging will build back across West Central Texas next week. This will result in a return of above normal temperatures and generally dry conditions. Daniels && .PRELIMINARY POINT TEMPS/POPS... Abilene 95 73 96 72 / 0 0 0 20 San Angelo 96 72 97 72 / 0 0 0 5 Junction 94 70 94 71 / 0 0 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... None. && $$ 20/Daniels
AREA FORECAST DISCUSSION
NWS SEATTLE WA
330 AM PDT THU SEP 17 2015 .SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRING RAIN AT TIMES TO WESTERN WASHINGTON THIS MORNING BEFORE TAPERING TO SHOWERS THIS AFTERNOON. THE TROUGH WILL SHIFT EAST TONIGHT WITH RESIDUAL SHOWERS AND A PUGET SOUND CONVERGENCE ZONE POSSIBLE. DRIER CONDITIONS ARE LIKELY FRIDAY THROUGH SATURDAY NIGHT...THOUGH SYSTEMS BRUSHING THE AREA COULD BRING A LITTLE RAIN TO THE FAR NORTH AND COAST AND TIMES. ANOTHER FRONT WILL ARRIVE SUNDAY AND SUNDAY NIGHT...POSSIBLY LINGERING INTO MONDAY. DRIER WEATHER IS POSSIBLE BY TUESDAY AND WEDNESDAY. && .SHORT TERM...RADAR IS QUITE ACTIVE THIS MORNING INDICATING VIGOROUS SHOWER BANDS ROTATING INLAND ACROSS WRN WA. HIGHEST RAIN AMOUNTS OVERNIGHT WERE NEAR THE COAST...OVER THE OLYMPICS...AND THE SOUTHWEST INTERIOR WITH UP TO A QUARTER INCH IN SPOTS. THE REST OF THE INTERIOR HAS GENERALLY ONLY SEEN A TENTH OR LESS. IR SATELLITE IMAGERY SHOWS THE COLDEST CLOUD TOPS ASSOCIATED WITH A SHORT WAVE NEARING THE WA/OREGON COASTS. MODEL SURFACE BASED LI`S SUGGEST THUNDERSTORMS SHOULD MOSTLY REMAIN OVER THE COASTAL WATERS. HOWEVER...A DOPPLER INDICATED MESO CONVECTIVE FEATURE WITH EMBEDDED LIGHTNING STRIKES MAY HOLD TOGETHER AS IT MOVES ONTO INLAND NEAR GRAYS HARBOR WITHIN THE NEXT HOUR OR TWO. WILL ADD A MENTION OF THUNDER TO JUST THE SOUTH CENTRAL PORTION OF THE COAST FOR THIS MORNING. RAIN AT TIMES WILL PERSIST ELSEWHERE UNTIL THE TROUGH AXIS MOVES INLAND THIS AFTERNOON WITH PRECIPITATION BECOMING MORE SCATTERED. HIGHS TODAY WILL REMAIN IN THE 60S. SHOWERS WILL DECREASE THIS EVENING WITH LOSS OF DIURNAL INSTABILITY AND THE TROUGH AXIS MOVING EAST. THE SURFACE RIDGE PATTERN WEST OF PUGET SOUND WILL FAVOR A PUGET SOUND CONVERGENCE ZONE WHICH COULD LINGER IN THE FAVORED SEATTLE TO EVERETT CORRIDOR TONIGHT. 500 MB HEIGHTS RISE ON FRIDAY BY THE FLOW IS STILL NWLY AND MORE ZONAL THAN PAST RUNS. THE 06Z GFS SHOWS SOME LIGHT QPF OVER THE COAST AND NORTH WHICH IS SOMEWHAT OF AN OUTLIER COMPARED TO OTHER DRIER MODELS. WILL STILL KEEP SOME LOW POPS FOR THE NORTH COAST AND OLYMPICS/N CASCADES BUT DRY ELSEWHERE. ONSHORE FLOW WILL BE WEAKER BUT CLOUDS WILL STILL BE AROUND TO SOME EXTENT HOLDING BACK TEMPERATURES. HIGHS STRUGGLING TO REACH 70 INLAND. FRIDAY NIGHT AND SATURDAY LOOK LIKE A DRIER PERIOD WITH A SOMEWHAT STRONGER RIDGE. THE MAIN MOISTURE FLOW WILL BE AIMED AT B.C. BUT STILL BRUSHING THE FAR NORTH PART OF WA AT TIMES...ESPECIALLY THE NORTH COAST. KEPT SOME LOW CHANCE POPS NORTH OF EVERETT DURING THIS PERIOD. AROUND GREATER PUGET SOUND...PARTLY TO MOSTLY CLEAR SKIES ARE EXPECTED WITH SLIGHT WARMING INTO THE LOW 70S SATURDAY. .LONG TERM...EXTENDED MODELS CONTINUE TO HAVE DIFFICULTY WITH THE TIMING AND STRENGTH OF SYSTEMS FROM SUNDAY INTO THE MIDDLE OF NEXT WEEK. THE LATEST 00Z GFS/ECMWF AT LEAST GENERALLY AGREE ON A STRONGER FRONT PUSHING THROUGH WRN WA LATER SUNDAY OR SUNDAY NIGHT WITH A ROUND OF RAIN FOR MOST THE AREA. QPF AMOUNTS AND TIMING STILL REMAIN FAIRLY UNCERTAIN. LIGHT RAIN OR SHOWERS MAY LINGER INTO MONDAY...THEN MOST MODELS NOW POINT TOWARD A GRADUAL DRYING TREND. ANOTHER FRONT MAY APPROACH THE COAST BY LATER WEDNESDAY. MERCER && .AVIATION...AN UPPER LEVEL TROUGH OVER THE COASTAL WATERS AT 09Z WILL MOVE INLAND OVER W WA THIS MORNING AND E OF THE CASCADES AROUND 18Z. CIGS REMAIN VFR OVC030-070 IN -RA BUT ARE EXPECTED TO LOWER TO MVFR OVC010-030 THIS MORNING. THE TROUGH AXIS WILL MOVE OVER E WA 18Z WITH SLIGHTLY DRIER NW FLOW ALOFT DEVELOPING OVER W WA BEHIND THE TROUGH. SHOWERS WILL DECREASE AND CIGS ARE EXPECTED TO LIFT TO VFR BKN040-060 BETWEEN 20Z-00Z. KSEA...CIGS REMAIN AROUND BKN-OVC050 THIS MORNING BUT LOWER MVFR CIGS AROUND 2000 FT ARE STILL EXPECTED TO FORM AS THE MAIN AREA OF RAIN MOVES N OF THE TERMINAL. THERE IS ANOTHER LINE OF SHOWERS ALONG THE COAST AT 10Z ASSOCIATED WITH A TROUGH AXIS THAT COULD BRING A FEW SHOWERS TO THE TERMINAL LATER THIS MORNING. CONFIDENCE IS PRETTY GOOD THAT THERE WILL BE A PERIOD OF MVFR CIGS THIS MORNING BUT JUST HOW LONG IS IN QUESTION. CIGS SHOULD LIFT TO VFR BKN040-060 AFTER 21Z. SURFACE WINDS WILL BE SOUTHERLY 5-10 KT. KAM && .MARINE...A 1007 MB SURFACE LOW OVER THE COASTAL WATERS AROUND 2 AM WILL MOVE INLAND THIS MORNING AND DISSIPATE. A SURFACE RIDGE WILL BUILD OVER THE WA COAST THIS AFTERNOON...THEN CONTINUE THROUGH SATURDAY. A SURFACE TROUGH WILL MOVE OVER THE OFFSHORE WATERS FRIDAY AND WILL BE CLOSE AND STRONG ENOUGH TO RAISE SCA WINDS OVER THE COASTAL WATERS BEFORE IT WEAKENS OFFSHORE. A WARM FRONT WILL MOVE ACROSS SOUTHERN B.C. ON SATURDAY. S FLOW SHOULD INCREASE OVER THE COAST AND N INTERIOR AND FUTURE MODEL RUNS MAY SHOW STRONGER WINDS. THE TRAILING COLD FRONT WILL MOVE RAPIDLY SE ACROSS W WA ON SUNDAY. THE GFS SHOWS A MODERATELY STRONG PRESSURE GRADIENT WITH THE FRONT AND IT LOOKS LIKE THERE IS A GOOD CHANCE OF SCA WINDS. ONSHORE FLOW INCREASES STRONGLY BEHIND THE FRONT LATE SUNDAY AFTERNOON. THE 00Z GFS IS SHOWING 5.5 MB UIL-BLI FOR 00Z MONDAY. IT IS PROBABLY A LITTLE EARLY BUT I OPTED TO INDICATE GALES IN THE CENTRAL AND E STRAIT. KAM && .SEW WATCHES/WARNINGS/ADVISORIES... WA...NONE. ] PZ...NONE. && $$ WWW.WEATHER.GOV/SEATTLE YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion National Weather Service Spokane WA 254 AM PDT THU SEP 17 2015 .SYNOPSIS... Today will be a cool and showery day with the best chance for precipitation over the central and southern Idaho Panhandle. A warming trend is expected Friday through the weekend with temperatures climbing into the 70s Saturday and Sunday. A strong frontal system will bring windy weather to the region on Sunday. Next week looks dry Monday through Wednesday with near average temperatures. && .DISCUSSION... Today through Friday night...An upper level trough off the Washington coast will drop southeast across southern Washington, Oregon, and central Idaho today. With this trajectory models continue to favor rain showers along the East Slopes of the Cascades, SE Washington, Lewiston area, Camas Prairie, and Central Panhandle Mountains. Models continue to show some differences with qpf totals, but have leaned more heavily towards the ECMWF solutions which has the best handle on precip totals thus far. The ECMWF suggests around a tenth of an inch or less in the aforementioned areas...with only a chance of showers elsewhere. Overall this is a decrease compared to what was previously expected. For this afternoon models show the best instability over the Idaho Panhandle and Camas Prairie where a slight chance of thunderstorms is forecast over the high terrain. If any storms occur they will be brief and short lived with cloud cover likely be a limiting factor for storm development. This system exits tonight bringing about drier conditions except for possibly a few lingering showers over the Idaho Panhandle. A moist boundary layer over NE Washington and North Idaho Panhandle will likely lead to increasing areas of stratus and patchy fog overnight into Friday morning. Another system passes by north of the Canadian border Friday afternoon into Friday night. Main impact from this will be mid and high clouds...along with a chance of light showers or sprinkles near the Canadian border and Cascade crest. JW Saturday and Sunday: The evening model runs continue to forecast a mainly dry weekend with the passage of a vigorous low pressure system through southern Canada on Sunday. What this system lacks in precipitation, it will compensate with wind. The brunt of the wind will occur on Sunday as a deep surface low forms in the lee of the Canadian Rockies north of Calgary. The tight westerly pressure gradient will peak late in the day Sunday between the Alberta low and high pressure along the Washington coast. Strong momentum aloft will contribute to the windy conditions as a 120kt jet core (at 250mb) sets up the BC/Washington border. With 850mb winds of in the neighborhood of 30kts over central Washington to the Idaho Panhandle, it looks like sustained winds of 20-25mph in the afternoon with gusts to 35 mph. Blowing dust may need to be added to the forecast especially if rain does not materialize today. As far as precipitation chances, the Cascade crest will have the best shot of rain (60-80 percent) with the cold frontal passage Sunday afternoon/ evening. Chances east of the Cascades will fall off dramatically in the strong west flow with 20-40 percent chances in the mountains along the Canadian border, and 10 percent or less in the Basin, Palouse, Spokane area. Monday through Wednesday: Behind Sunday`s cold front, Monday looks to be breezy in the afternoon with afternoon winds in the 10-20mph range. Humidity levels on Monday will be considerably lower than on Sunday, and we may see some areas flirt with Red Flag criteria for wind and low humidity. As the winds diminish Monday night, the dry air mass over the region combined with clearing skies will support strong radiational cooling. Sheltered valleys in north Idaho and northeast Washington will drop into the lower to mid 30s Tuesday and Wednesday morning. Look for large diurnal temperature swings with places like Deer Park, Springdale, and Republic. Morning lows in the low 30s Tuesday/Wednesday morning climbing to near 70 in the afternoon. We are nearing the autumn equinox, a time for big diurnal temperature swings. /GKoch && .AVIATION... 06Z TAFS: Light rain expected to develop over Central and Southeast Washington into the lower Idaho Panhandle by 10Z...spreading to all TAF sites after 15Z. The system is splitting while coming onshore and looks to bring very light spotty rain in the northern Basin and northern mountains. CIGS are expected to remain VFR at the TAF sites through 12z Thursday but there is a chance of MVFR Ceilings after 15Z near the Cascades and over SE Washington. Rain will transition to showers after 18z with a small chance for a few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z. Confidence for t-storms is low at this point. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 58 46 64 47 72 53 / 50 10 10 10 10 10 Coeur d`Alene 58 46 64 46 71 50 / 60 20 10 10 10 10 Pullman 58 45 67 46 72 50 / 70 10 10 0 10 10 Lewiston 63 49 73 50 77 55 / 70 10 10 0 10 0 Colville 59 45 64 45 73 48 / 30 10 10 10 10 10 Sandpoint 58 44 62 43 68 46 / 40 20 20 10 10 10 Kellogg 56 46 63 44 67 48 / 70 50 20 10 10 10 Moses Lake 67 45 72 48 77 53 / 40 10 0 0 10 10 Wenatchee 68 51 71 54 79 59 / 50 10 0 0 10 10 Omak 67 44 71 49 76 52 / 40 10 10 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
Area Forecast Discussion National Weather Service Spokane WA 254 AM PDT THU SEP 17 2015 .SYNOPSIS... Today will be a cool and showery day with the best chance for precipitation over the central and southern Idaho Panhandle. A warming trend is expected Friday through the weekend with temperatures climbing into the 70s Saturday and Sunday. A strong frontal system will bring windy weather to the region on Sunday. Next week looks dry Monday through Wednesday with near average temperatures. && .DISCUSSION... Today through Friday night...An upper level trough off the Washington coast will drop southeast across southern Washington, Oregon, and central Idaho today. With this trajectory models continue to favor rain showers along the East Slopes of the Cascades, SE Washington, Lewiston area, Camas Prairie, and Central Panhandle Mountains. Models continue to show some differences with qpf totals, but have leaned more heavily towards the ECMWF solutions which has the best handle on precip totals thus far. The ECMWF suggests around a tenth of an inch or less in the aforementioned areas...with only a chance of showers elsewhere. Overall this is a decrease compared to what was previously expected. For this afternoon models show the best instability over the Idaho Panhandle and Camas Prairie where a slight chance of thunderstorms is forecast over the high terrain. If any storms occur they will be brief and short lived with cloud cover likely be a limiting factor for storm development. This system exits tonight bringing about drier conditions except for possibly a few lingering showers over the Idaho Panhandle. A moist boundary layer over NE Washington and North Idaho Panhandle will likely lead to increasing areas of stratus and patchy fog overnight into Friday morning. Another system passes by north of the Canadian border Friday afternoon into Friday night. Main impact from this will be mid and high clouds...along with a chance of light showers or sprinkles near the Canadian border and Cascade crest. JW Saturday and Sunday: The evening model runs continue to forecast a mainly dry weekend with the passage of a vigorous low pressure system through southern Canada on Sunday. What this system lacks in precipitation, it will compensate with wind. The brunt of the wind will occur on Sunday as a deep surface low forms in the lee of the Canadian Rockies north of Calgary. The tight westerly pressure gradient will peak late in the day Sunday between the Alberta low and high pressure along the Washington coast. Strong momentum aloft will contribute to the windy conditions as a 120kt jet core (at 250mb) sets up the BC/Washington border. With 850mb winds of in the neighborhood of 30kts over central Washington to the Idaho Panhandle, it looks like sustained winds of 20-25mph in the afternoon with gusts to 35 mph. Blowing dust may need to be added to the forecast especially if rain does not materialize today. As far as precipitation chances, the Cascade crest will have the best shot of rain (60-80 percent) with the cold frontal passage Sunday afternoon/ evening. Chances east of the Cascades will fall off dramatically in the strong west flow with 20-40 percent chances in the mountains along the Canadian border, and 10 percent or less in the Basin, Palouse, Spokane area. Monday through Wednesday: Behind Sunday`s cold front, Monday looks to be breezy in the afternoon with afternoon winds in the 10-20mph range. Humidity levels on Monday will be considerably lower than on Sunday, and we may see some areas flirt with Red Flag criteria for wind and low humidity. As the winds diminish Monday night, the dry air mass over the region combined with clearing skies will support strong radiational cooling. Sheltered valleys in north Idaho and northeast Washington will drop into the lower to mid 30s Tuesday and Wednesday morning. Look for large diurnal temperature swings with places like Deer Park, Springdale, and Republic. Morning lows in the low 30s Tuesday/Wednesday morning climbing to near 70 in the afternoon. We are nearing the autumn equinox, a time for big diurnal temperature swings. /GKoch && .AVIATION... 06Z TAFS: Light rain expected to develop over Central and Southeast Washington into the lower Idaho Panhandle by 10Z...spreading to all TAF sites after 15Z. The system is splitting while coming onshore and looks to bring very light spotty rain in the northern Basin and northern mountains. CIGS are expected to remain VFR at the TAF sites through 12z Thursday but there is a chance of MVFR Ceilings after 15Z near the Cascades and over SE Washington. Rain will transition to showers after 18z with a small chance for a few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z. Confidence for t-storms is low at this point. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 58 46 64 47 72 53 / 50 10 10 10 10 10 Coeur d`Alene 58 46 64 46 71 50 / 60 20 10 10 10 10 Pullman 58 45 67 46 72 50 / 70 10 10 0 10 10 Lewiston 63 49 73 50 77 55 / 70 10 10 0 10 0 Colville 59 45 64 45 73 48 / 30 10 10 10 10 10 Sandpoint 58 44 62 43 68 46 / 40 20 20 10 10 10 Kellogg 56 46 63 44 67 48 / 70 50 20 10 10 10 Moses Lake 67 45 72 48 77 53 / 40 10 0 0 10 10 Wenatchee 68 51 71 54 79 59 / 50 10 0 0 10 10 Omak 67 44 71 49 76 52 / 40 10 10 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
Area Forecast Discussion National Weather Service Spokane WA 1147 PM PDT WED SEP 16 2015 .SYNOPSIS... Cool and showery conditions will prevail through the week as a series of Pacific storms move through the Inland Northwest. Tonight into Thursday will feature our best shot of rain. Look for a warming and drying trend over the weekend. Breezy conditions are expected Sunday and Monday followed by mild and dry conditions early next week. && .DISCUSSION... Late evening update just sent out based on current radar trends and model data. Main changes were to further lower pops tonight based on latest HRRR data which shows the best chances for rain along the East Slopes of the Cascades, and over SE Washington and the Camas Prairie late tonight. Satellite shows a couple waves with one tracking towards western Washington and another over Oregon that will track towards Central Idaho tonight. The 00z ECMWF appears to have the best handle on this scenario with the GFS and NAM overdone with its current precipitation totals over western and south central Washington. JW && .AVIATION... 06Z TAFS: Light rain expected to develop over Central and Southeast Washington into the lower Idaho Panhandle by 10Z...spreading to all TAF sites after 15Z. The system is splitting while coming onshore and looks to bring very light spotty rain in the northern Basin and northern mountains. CIGS are expected to remain VFR at the TAF sites through 12z Thursday but there is a chance of MVFR Ceilings after 15Z near the Cascades and over SE Washington. Rain will transition to showers after 18z with a small chance for a few weak thunderstorms in the Idaho Panhandle and far NE WA btwn 21-02Z. Confidence for t-storms is low at this point. /sb && .PRELIMINARY POINT TEMPS/POPS... Spokane 46 56 46 64 46 71 / 10 70 20 10 10 10 Coeur d`Alene 45 57 49 63 43 70 / 10 70 30 10 10 10 Pullman 45 56 45 65 44 72 / 40 70 20 10 0 10 Lewiston 51 63 49 71 50 77 / 50 80 20 10 0 10 Colville 42 58 45 65 41 71 / 10 60 20 10 10 10 Sandpoint 37 56 44 60 39 67 / 0 70 30 20 10 10 Kellogg 42 54 46 61 42 66 / 10 70 50 10 10 10 Moses Lake 48 65 45 71 47 77 / 20 40 10 0 0 10 Wenatchee 53 66 51 72 53 78 / 20 50 10 0 10 10 Omak 49 66 46 70 48 77 / 10 40 10 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1038 PM CDT FRI SEP 18 2015 UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE .SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 213 PM CDT FRI SEP 18 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE GATHERING STRENGTH OVER KANSAS AS A SHORTWAVE TROUGH MOVES EAST ACROSS THE NORTHERN PLAINS. SHOWERS AND STORMS ARE INCREASING IN COVERAGE AHEAD OF THE LOW ACROSS IOWA AND FAR SOUTHERN MINNESOTA. A SECONDARY NARROW BAND OF RAIN IS ALSO MOVING NORTHEAST OVER WESTERN WI WITHIN A MID-LEVEL FGEN ZONE. LAST NITES COLD FRONT HAS SETTLED FROM NORTHERN ILLINOIS TO NORTHEAST LOWER MICHIGAN...BUT CLOUDS BEHIND THE FRONT HAVE LINGERED OVER EAST-CENTRAL WI THROUGH EARLY THIS AFTERNOON. DO NOT THINK THESE CLOUDS WILL MOVE MUCH WITH THE FRONT NEARLY STALLED. AS THE LOW MOVES NORTHEAST ALONG THE FRONT...RAIN TIMING AND AMOUNTS ARE THE MAIN FORECAST CONCERNS. TONIGHT...LOW PRESSURE WILL TRAVEL FROM THE MID-MISSISSIPPI VALLEY TO CENTRAL LAKE HURON. ON THE NORTHERN SIDE OF THE LOW...FORCING IN THE FORM OF MID-LEVEL FGEN AND UPPER DIVERGENCE WILL BE EXCELLENT. A SECONDARY BAND OF FGEN WILL ALSO MOVE ACROSS NORTH-CENTRAL WI FOR THE EVENING AHEAD OF THE MID-LEVEL SHORTWAVE THAT IS CURRENTLY OVER THE NORTHERN PLAINS. SO ANTICIPATE THE MAIN BRUNT OF THE RAIN TO PUSH NORTHEAST THIS EVENING FROM THE PLAINS AND SPREAD ACROSS MUCH OF CENTRAL AND NORTHEAST WISCONSIN FROM MID-EVENING THROUGH THE EARLY MORNING HOURS. THE SECONDARY BAND OF RAIN SHOULD ALSO IMPACT NORTH-CENTRAL WI EARLY TO MID-EVENING BEFORE BEING OVERTAKEN BY THE MAIN AREA OF RAIN. MID-LEVEL THETAE LAPSE RATES SUGGEST THE CHANCE OF THUNDER IS RATHER LOW...BUT GIVEN THE MAGNITUDE OF THE FORCING...WILL LEAVE A CHANCE OVER THE SOUTHEAST HALF OF THE FORECAST AREA. RAINFALL AMOUNTS COULD BE RATHER BEEFY OVER EAST- CENTRAL WI...POSSIBLY OVER AN INCH. BUT THE QUICK MOTION OF THE LOW SUGGESTS THE CHANCE OF FLOODING IS TOO LOW TO MENTION. THE RAIN WILL BE PULLING OUT LATE TONIGHT AND SOME CLEARING COULD ALREADY BE MOVING INTO THE I-39/ROUTE 51 CORRIDOR BY 12Z. LOWS IN THE UPPER 40S TO MID 50S. SATURDAY...WITH THE RAIN EXPECTED TO HAVE EXITED ACROSS THE REGION EXCEPT FOR POSSIBLY THE DOOR...CLEARING SHOULD QUICKLY MOVE FROM WEST TO EAST OVER THE COURSE OF THE MORNING. AMPLE SUNSHINE SHOULD THEN RETURN FOR THE AFTERNOON WHEN HIGHS SHOULD REACH FROM THE MID TO UPPER 60S. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 213 PM CDT FRI SEP 18 2015 HIGH PRESSURE WILL DOMINATE THE FCST FOR THE END OF THE WEEKEND AND BEGINNING OF THE NEXT WORK WEEK. WILL CONTINUE TO MENTION PATCHY FOG LATE SATURDAY NIGHT...GIVEN RECENT RAIN...LIGHT WINDS AND CLEAR SKIES. WILL LIKELY SEE A FEW SPOTS IN NORTH CENTRAL WI DROP INTO THE UPPER 30S...AND WILL NEED TO MONITOR FOR PATCHY FROST POTENTIAL WITH SUBSEQUENT FCSTS. EXPECT A GRADUAL WARMING TREND AS SW WINDS DEVELOP AND INCREASE ON THE NW PERIPHERY OF THE SFC HIGH. MODELS ARE SHOWING A WEAK FRONT MEANDERING AROUND THE REGION FOR THE REST OF THE WORK WEEK...PASSING THROUGH AS A COLD FRONT LATE MONDAY NIGHT INTO TUESDAY...LIFTING BACK NORTH AS A WARM FRONT ON WEDNESDAY...THEN RETURNING AS A COLD FRONT ON THURSDAY AND THURSDAY NIGHT. SMALL CHANCES OF SHOWERS AND TSTMS ARE ANTICIPATED...MOST NOTABLY OVER THE NW HALF OF THE FORECAST AREA. TEMPERATURES SHOULD REMAIN ABOVE NORMAL FOR MOST OF THE PERIOD... THEN RETURN TO NEAR NORMAL AT THE END OF THE WEEK. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1038 PM CDT FRI SEP 18 2015 LOW PRESSURE WILL TRACK ALONG A COLD FRONT LOCATED ACROSS THE WESTERN GREAT LAKES TONIGHT...BRINGING WIDESPREAD RAIN TO MUCH OF THE REGION. THE HEAVIEST RAIN WILL OCCUR OVER EAST- CENTRAL AND NORTHEAST WI WHERE MVFR CONDITIONS ARE LIKELY AND IFR CONDITIONS ARE POSSIBLE. A QUICK IMPROVEMENT IS EXPECTED LATE TONIGHT AS THE LOW PULLS OUT...LEAVING VFR CONDITIONS ACROSS THE REGION BY MID-MORNING ON SATURDAY. VFR CONDITIONS ARE EXPECTED TO LAST SATURDAY AFTERNOON AND INTO THE EVENING HOURS. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......KURIMSKI
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
608 PM CDT FRI SEP 18 2015 UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE .SHORT TERM...TONIGHT AND SATURDAY ISSUED AT 213 PM CDT FRI SEP 18 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE GATHERING STRENGTH OVER KANSAS AS A SHORTWAVE TROUGH MOVES EAST ACROSS THE NORTHERN PLAINS. SHOWERS AND STORMS ARE INCREASING IN COVERAGE AHEAD OF THE LOW ACROSS IOWA AND FAR SOUTHERN MINNESOTA. A SECONDARY NARROW BAND OF RAIN IS ALSO MOVING NORTHEAST OVER WESTERN WI WITHIN A MID-LEVEL FGEN ZONE. LAST NITES COLD FRONT HAS SETTLED FROM NORTHERN ILLINOIS TO NORTHEAST LOWER MICHIGAN...BUT CLOUDS BEHIND THE FRONT HAVE LINGERED OVER EAST-CENTRAL WI THROUGH EARLY THIS AFTERNOON. DO NOT THINK THESE CLOUDS WILL MOVE MUCH WITH THE FRONT NEARLY STALLED. AS THE LOW MOVES NORTHEAST ALONG THE FRONT...RAIN TIMING AND AMOUNTS ARE THE MAIN FORECAST CONCERNS. TONIGHT...LOW PRESSURE WILL TRAVEL FROM THE MID-MISSISSIPPI VALLEY TO CENTRAL LAKE HURON. ON THE NORTHERN SIDE OF THE LOW...FORCING IN THE FORM OF MID-LEVEL FGEN AND UPPER DIVERGENCE WILL BE EXCELLENT. A SECONDARY BAND OF FGEN WILL ALSO MOVE ACROSS NORTH-CENTRAL WI FOR THE EVENING AHEAD OF THE MID-LEVEL SHORTWAVE THAT IS CURRENTLY OVER THE NORTHERN PLAINS. SO ANTICIPATE THE MAIN BRUNT OF THE RAIN TO PUSH NORTHEAST THIS EVENING FROM THE PLAINS AND SPREAD ACROSS MUCH OF CENTRAL AND NORTHEAST WISCONSIN FROM MID-EVENING THROUGH THE EARLY MORNING HOURS. THE SECONDARY BAND OF RAIN SHOULD ALSO IMPACT NORTH-CENTRAL WI EARLY TO MID-EVENING BEFORE BEING OVERTAKEN BY THE MAIN AREA OF RAIN. MID-LEVEL THETAE LAPSE RATES SUGGEST THE CHANCE OF THUNDER IS RATHER LOW...BUT GIVEN THE MAGNITUDE OF THE FORCING...WILL LEAVE A CHANCE OVER THE SOUTHEAST HALF OF THE FORECAST AREA. RAINFALL AMOUNTS COULD BE RATHER BEEFY OVER EAST- CENTRAL WI...POSSIBLY OVER AN INCH. BUT THE QUICK MOTION OF THE LOW SUGGESTS THE CHANCE OF FLOODING IS TOO LOW TO MENTION. THE RAIN WILL BE PULLING OUT LATE TONIGHT AND SOME CLEARING COULD ALREADY BE MOVING INTO THE I-39/ROUTE 51 CORRIDOR BY 12Z. LOWS IN THE UPPER 40S TO MID 50S. SATURDAY...WITH THE RAIN EXPECTED TO HAVE EXITED ACROSS THE REGION EXCEPT FOR POSSIBLY THE DOOR...CLEARING SHOULD QUICKLY MOVE FROM WEST TO EAST OVER THE COURSE OF THE MORNING. AMPLE SUNSHINE SHOULD THEN RETURN FOR THE AFTERNOON WHEN HIGHS SHOULD REACH FROM THE MID TO UPPER 60S. .LONG TERM...SATURDAY NIGHT THROUGH FRIDAY ISSUED AT 213 PM CDT FRI SEP 18 2015 HIGH PRESSURE WILL DOMINATE THE FCST FOR THE END OF THE WEEKEND AND BEGINNING OF THE NEXT WORK WEEK. WILL CONTINUE TO MENTION PATCHY FOG LATE SATURDAY NIGHT...GIVEN RECENT RAIN...LIGHT WINDS AND CLEAR SKIES. WILL LIKELY SEE A FEW SPOTS IN NORTH CENTRAL WI DROP INTO THE UPPER 30S...AND WILL NEED TO MONITOR FOR PATCHY FROST POTENTIAL WITH SUBSEQUENT FCSTS. EXPECT A GRADUAL WARMING TREND AS SW WINDS DEVELOP AND INCREASE ON THE NW PERIPHERY OF THE SFC HIGH. MODELS ARE SHOWING A WEAK FRONT MEANDERING AROUND THE REGION FOR THE REST OF THE WORK WEEK...PASSING THROUGH AS A COLD FRONT LATE MONDAY NIGHT INTO TUESDAY...LIFTING BACK NORTH AS A WARM FRONT ON WEDNESDAY...THEN RETURNING AS A COLD FRONT ON THURSDAY AND THURSDAY NIGHT. SMALL CHANCES OF SHOWERS AND TSTMS ARE ANTICIPATED...MOST NOTABLY OVER THE NW HALF OF THE FORECAST AREA. TEMPERATURES SHOULD REMAIN ABOVE NORMAL FOR MOST OF THE PERIOD... THEN RETURN TO NEAR NORMAL AT THE END OF THE WEEK. && .AVIATION...FOR 00Z TAF ISSUANCE ISSUED AT 608 PM CDT FRI SEP 18 2015 LOW PRESSURE WILL TRACK ALONG A COLD FRONT LOCATED ACROSS THE WESTERN GREAT LAKES TONIGHT...BRINGING WIDESPREAD RAIN TO MUCH OF THE REGION. THE HEAVIEST RAIN WILL OCCUR OVER EAST- CENTRAL AND NORTHEAST WI WHERE IFR CONDITIONS ARE LIKELY. A QUICK IMPROVEMENT IS EXPECTED LATE TONIGHT AS THE LOW PULLS OUT...LEAVING VFR CONDITIONS ACROSS THE REGION BY MID-MORNING ON SATURDAY. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......KURIMSKI
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND FRIDAY ISSUED AT 250 PM CDT THU SEP 17 2015 THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE OVER NORTHWEST ONTARIO...AND A COLD FRONT EXTENDING SOUTHWEST ACROSS WESTERN MINNESOTA TO THE CENTRAL PLAINS. A BAND OF SHOWERS AND STORMS ASSOCIATED WITH MID-LEVEL MOISTURE TRANSPORT AND WEAK SHORTWAVE IMPULSES HAVE BEEN SLOWLY WEAKENING EARLY THIS AFTERNOON AS THEY RUN INTO A MORE STABLE AIRMASS OVER CENTRAL AND EASTERN WI. BUT SOME OF THIS RAIN SHOULD SURVIVE THE TRIP INTO NORTHEAST WI. HOWEVER...THE RAIN AND CLOUD COVER HAVE HELD BACK TEMPERATURES ACROSS MUCH OF WESTERN AND CENTRAL WISCONSIN...THEREBY PREVENTING A SIGNFICANT RISE OF INSTABILITY AND REDUCING THE RISK OF SEVERE WEATHER. THE BEST INSTABILITY RESIDES OVER MINNESOTA JUST AHEAD OF THE FRONT WHERE STORMS ARE ANTICIPATED TO REDEVELOP LATER THIS AFTERNOON. AS THE FRONT MOVES EAST TONIGHT...THUNDERSTORM IMPACTS ARE THE MAIN FORECAST CONCERN. TONIGHT...THE COLD FRONT WILL MOVE EAST....ACROSS WESTERN AND CENTRAL WISCONSIN THIS EVENING...AND EASTERN WISCONSIN OVERNIGHT. AHEAD OF THE FRONT...WILL HAVE IMPRESSIVE MOISTURE TRANSPORT WITH PWATS BETWEEN 1.5 AND 2.0 INCHES AND ELEVATED CAPES AROUND 1000 J/KG...THOUGH THINK THE ATMOSPHERE WILL GET WORKED OVER A LITTLE BY THIS AFTERNOONS CONVECTION. SO THE SEVERE THREAT DOES NOT LOOK AS IMPRESSIVE AS YESTERDAY GIVEN THE MARGINAL INSTABILITY...WHICH MATCHES SPC/S ASSESSMENT. STILL THOUGH...A FEW STRONG STORMS CAPABLE OF PRODUCING STRONG STRAIGHT LINE WINDS CANNOT BE RULED OUT THIS EVENING OVER CENTRAL AND NORTH-CENTRAL WISCONSIN AS CONVECTION ROLLS IN FROM THE WEST. THE MAIN THREAT WILL BE HEAVY RAINFALL HOWEVER. UPSTREAM OBS OVER WESTERN WISCONSIN FROM EARLIER TODAY REPORTED UPWARDS OF 2.5 INCHES OF RAINFALL. GIVEN THE HIGH PWATS AND SLOW MOVEMENT OF THE CONVECTION...THINK ISOLATED AMOUNTS COULD REACH THIS AMOUNT. THE CONVECTION WILL BE WEAKENING AS IT MOVES INTO EASTERN WISCONSIN LATE IN THE EVENING AND OVERNIGHT WHERE RAINFALL POTENTIAL IS NOT NEARLY AS HIGH. LOW CLOUDS WILL LIKELY LINGER BEHIND THE FRONT EVEN AS WINDS SHIFT TO THE NW. AS A RESULT...LOWS SHOULD ONLY FALL INTO THE UPPER 50S WEST TO MID 60S EAST. FRIDAY...WILL LEAVE A SLIGHT CHANCE OF A SHOWER ALONG THE LAKE SHORE AT THE START OF THE MORNING. BUT OTHERWISE...THINK THE SHOWER ACTIVITY WILL HAVE PASSED TO THE EAST OF THE REGION BY 12Z AS THE FRONT MOVES OVER LAKE MICHIGAN. THEN A DRY PERIOD SHOULD ENSUE THROUGH AT LEAST MID-AFTERNOON AS NORTHWEST WINDS BRING IN DRIER AIR. BY LATE AFTERNOON...THE RIGHT REAR QUAD OF A JETSTREAK COMBINED WITH MID-LEVEL FGEN WILL PROMOTE A BAND OF LIGHT RAIN LIFTING NORTHWARD TOWARDS NORTH-CENTRAL WI. BUT THE NEXT ROUND OF PRECIP SHOULD MAINLY HOLD OFF UNTIL FRIDAY NIGHT. HIGHS COOLING OFF ON FRIDAY INTO THE MID 60S NORTH TO MID 70S SOUTH. .LONG TERM...FRIDAY NIGHT THROUGH THURSDAY ISSUED AT 250 PM CDT THU SEP 17 2015 PCPN TRENDS AND QPF AMOUNTS FRIDAY NIGHT INTO SATURDAY MORNING ARE THE MAIN FCST CONCERNS. MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT ON THE FRIDAY NIGHT SYSTEM...WITH A DEEPENING CYCLONE TRACKING NE THROUGH SOUTHERN LAKE MICHIGAN...AS A POTENT S/W TROF MOVES THROUGH THE WSTRN GREAT LAKES. STRONG DYNAMIC FORCING...COMBINED WITH PRECIPITABLE WATER VALUES OF 1-1.5 INCHES...WILL LEAD TO A SIGNIFICANT RAINFALL ACROSS ALL BUT THE NW PART OF THE CWA. HEAVY RAINFALL...WITH AMOUNTS IN EXCESS OF AN INCH...ARE POSSIBLE IN THE FOX VALLEY/ LAKESHORE AREAS. AFTER LOOKING AT PROGS OF ELEVATED INSTABILITY... WILL CONFINE TSTM CHANCES TO ONLY OUR SE COUNTIES. LINGERING SHOWERS SHOULD QUICKLY EXIT NE WI EARLY SATURDAY MORNING...WITH DECREASING CLOUDS THROUGH THE DAY. A BRIEF PERIOD OF STRONG GUSTY NE-N WINDS IS EXPECTED OVER THE FOX VALLEY AND LAKESHORE AREAS LATE FRIDAY NIGHT INTO SATURDAY MORNING...AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED. HIGH PRESSURE WILL BRING DRY CONDITIONS FROM SATURDAY AFTERNOON THROUGH TUESDAY. HAVE ADDED A MENTION OF PATCHY FOG TO THE LATE SATURDAY NIGHT FCST. THERE IS A SMALL CHANCE OF TSTMS WED-THU AS WEAK FRONTAL BOUNDARY SAGS TOWARD NORTHERN WI. HOWEVER...THE ECMWF KEEPS A STRONG UPPER RIDGE IN PLACE...AND HAS THE FRONT REMAINING NORTH OF THE WI/MI BORDER. THUS...WILL ONLY HAVE SLGT CHC/CHC POPS AT THIS TIME. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1149 AM CDT THU SEP 17 2015 AN ACTIVE PERIOD OF WEATHER WILL MOVE ACROSS THE REGION THROUGH THE END OF THE TAF PERIOD. SHOWERS AND STORMS WILL IMPACT CENTRAL AND NORTH-CENTRAL WISCONSIN THROUGH EARLY THIS AFTERNOON. NOT SURE HOW FAR EAST THESE STORMS WILL MAKE IT...DUE TO A MORE STABLE AIRMASS IN THE EASTERN PART OF THE STATE. ONCE THIS FIRST ROUND EXITS/DIMINISHES...A SECOND ROUND OF STORMS IS ANTICIPATED TO MOVE ACROSS THE REGION LATE THIS AFTERNOON THROUGH THE EVENING. STRONG GUSTY WINDS AND HEAVY RAIN WILL BE POSSIBLE IN ANY STORMS. IN THE WAKE OF THESE STORMS...CIGS/VSBYS WILL LOWER TO IFR/LIFR ALONG THE COLD FRONT. SOME IMPROVEMENT IS EXPECTED FRIDAY MORNING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......KIECKBUSCH AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1149 AM CDT THU SEP 17 2015 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND FRIDAY ISSUED AT 310 AM CDT THU SEP 17 2015 FORECAST CHALLENGE CENTERS ON CONVECTION TRENDS TODAY INTO TONIGHT AND SEVERE POTENTIAL. AREA RADARS SHOW LEAD CONVECTION EARLY THIS MORNING NEAR THE MINNESOTA WISCONSIN BORDER IN THE LLJ REGION...HIGHER PWATS AND 850 MB WARM AIR ADVECTION. THIS FOCUS OF CONVECTION WILL GRADUALLY SHIFT EASTWARD TODAY BUT MAY DIMINISH FOR A PERIOD LATER THIS MORNING. A COLD FRONT AND MID LEVEL TROUGH WITH EVEN MORE CONVECTION WAS OVER THE NORTHERN PLAINS AND APPROACHING THE WESTERN GREAT LAKES REGION TODAY. SHOWERS AND STORMS WILL LIKELY BECOME MORE WIDESPREAD BY THIS AFTERNOON OVER WESTERN WISCONSIN AND THEN TOWARD EASTERN AREAS BY THIS EVENING AS THE INITIAL CONVECTION MERGES WITH THE WITH THE APPROACHING NORTHERN PLAINS SYSTEM. HRRR MODEL KEEPS THE LEAD WARM SECTOR CONVECTION AND THE FRONTAL CONVECTION A BIT MORE SEPARATE. BLEND OF MODEL RUNS SUGGEST A FASTER DEPARTURE TOWARD FRIDAY MORNING...WITH PERHAPS A BREAK IN PCPN FOR MUCH OF FRIDAY. PCPN BEGINS TO SPREAD BACK INTO THE AREA FROM SOUTHWEST TO NORTHEAST AS A SURFACE WAVE TRACKS ALONG THE FRONTAL BOUNDARY SOUTH OF THE AREA. THE NORTHERN AREAS ARE EXPECTED TO BE OVERALL DRY ON FRIDAY. LIFT WITH THE RRQ REGION OF THE UPPER JET NOT EXPECTED TO AFFECT THE AREA UNTIL AFTER FRIDAY AFTERNOON. AS FAR AS SEVERE POTENTIAL. BEST ML CAPE VALUES OCCUR THIS AFTERNOON OVER THE WEST HALF OF THE STATE INCLUDING CENTRAL AND NORTH CENTRAL WISCONSIN AND TOWARD EARLY EVENING OVER EASTERN AREAS. SHEAR WILL BE ON THE INCREASE THIS AFTERNOON AND EARLY EVENING AS MID LEVEL WINDS INCREASE AND TURN MORE WSW AS A MID LEVEL TROUGH OF LOW PRESSURE SLIDES ALONG THE US/CANADA BORDER. THESE LIKELY STRONGER WINDS ALOFT WILL INTERACT WITH THE SOUTH FLOW IN THE BOUNDARY LAYER AHEAD OF THE FRONT. THIS INCREASE IN SHEAR AND INSTABILITY WILL PRODUCE A WINDOW OF SEVERE POTENTIAL...BUT THE STRONGER WINDS ALOFT MAY ALSO PUSH THE STORMS EASTWARD FASTER OVERNIGHT. THE PRIMARY ISSUE WILL BE HEAVY RAIN DUE TO HIGHER PWATS AND DAMAGING WINDS. HAIL POSSIBLE WITH ANY SUPER STORM DEVELOPMENT IN THE SHEARED ENVIRONMENT BUT PROGGED FORECAST SOUNDINGS INDICATE WBZ START TO FALL BELOW 10000 FEET WELL AFTER THE FROPA AND CONVECTION. AMOUNT OF CLOUDS TODAY WILL OBVIOUSLY AFFECT AVAILABLE INSTABILITY. SPC HAS PAINTED A SLIGHT RISK DAY 1 TODAY OVER ALL OF CENTRAL WISCONSIN AND PARTS OF NORTH CENTRAL AND NORTHEAST WISCONSIN. LAST DAY OF ABOVE NORMAL TEMPERATURES THIS WEEK FOR TODAY FOLLOWED WITH NEAR NORMAL TEMPERATURES ON FRIDAY IN THE WAKE OF THE COLD FRONT. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY ISSUED AT 310 AM CDT THU SEP 17 2015 A WET START TO THE EXTENDED FCST AS A STRENGTHENING SFC LOW RIDES NE THRU THE GREAT LAKES...TRAILED BY A STRONG SHORTWAVE TROF. ONCE THIS SYSTEM CLEARS...MEAN FLOW TO BE DOMINATED BY A STRONG BAND OF WESTERLIES RUNNING FROM THE PAC NW E-EN INTO S-CNTRL CANADA. THIS KEEPS MOST WEATHER SYSTEMS TO OUR NW FOR THE FIRST HALF OF NEXT WEEK WITH TEMPS HOVERING NEAR OR SLIGHTLY ABOVE NORMAL. MODELS CONT TO BATTLE WITH THE INTERACTION OF A STRENGTHENING AREA OF LOW PRES RIDING NE ALONG THE CDFNT AND THE APPROACH OF A STRONG SHORTWAVE TROF/EMBEDDED SHORTWAVES FRI NGT. THE NAM REMAINS STRONGEST/FARTHEST WEST WITH THE TRACK OF THE SFC LOW...ALTHO THE ECMWF HAS TRENDED CLOSER TO THE NAM SOLUTION THAN 24 HOURS AGO. THE GFS/GEM ARE WEAKER/BIT FARTHER EAST WITH THE LOW TRACK. MODELS DO AGREE ON TWO MAIN AREAS OF PCPN WITH ONE STAYING TO OUR SOUTH ASSOCIATED WITH STRONG ISEN LIFT AND THE OTHER MOVING THRU WI ASSOCIATED WITH THE PRIMARY DEFORMATION ZONE. DESPITE THE MODEL DIFFERENCES...IT APPEARS THAT THE SE HALF OF WI COULD RECEIVE A HEALTHY RAINFALL FRI NGT WITH LOCALLY HEAVY RAINS POSSIBLE. MIN TEMPS TO RANGE FROM THE 45-50 DEG RANGE NORTH...LWR TO MID 50S SOUTH. THE BIGGER FCST ISSUE MAY ACTUALLY BE WHEN TO END THE PCPN CHCS ON SAT AS THE SLOWER NAM WOULD KEEP SHWRS GOING ALL DAY AS OPPOSED TO THE SHWRS ENDING BY MIDDAY ON THE OTHER MODELS. HAVE CONTINUED TO LEAN TOWARD THE MAJORITY SOLUTION MAINLY DUE TO THE PROGRESSIVE NATURE OF THE MEAN FLOW. THEREFORE...WL KEEP POPS IN THE FCST THRU SAT MORNING AND TREND TOWARD DECREASING CLOUDS IN THE AFTERNOON. MAX TEMPS ARE EXPECTED TO DIP SLIGHTLY BELOW NORMAL WITH READINGS GENERALLY IN THE LWR TO MID 60S NORTH...MID TO UPR 60S SOUTH. HI PRES IS FCST TO MOVE EAST FROM THE CNTRL PLAINS TOWARD SRN SECTIONS OF THE GREAT LAKES SAT NGT. MOSTLY CLEAR TO PARTLY CLOUDY SKIES...LIGHT WINDS AND A DRIER AIR MASS WL ALLOW FOR TEMPS TO FALL TO AROUND 40 DEGS OVER THE COLDER LOCATIONS OF THE NORTHWOODS...AROUND 50 DEGS ALONG LAKE MI. DEPENDING ON HOW MUCH RAIN FALLS FRI NGT/SAT MORNING...THERE COULD BE PATCHY FOG DEVELOPING JUST ABOUT ANYWHERE OVER NE WI. THE SFC HI WL DRIFT ACROSS THE GREAT LAKES ON SUNDAY WITH A RETURN FLOW DEVELOPING OVER WI. IN ADDITION...MODELS SUGGEST A WEAK SHORTWAVE TROF WL APPROACH THE GREAT LAKES SUNDAY AFTERNOON. THERE IS NOT ENUF LIFT/ FORCING/MOISTURE FOR ANY PCPN TO DEVELOP...HOWEVER WE MAY SEE SOME CLOUDS PUSH INTO THE FCST AREA THROUGHOUT THE DAY. MAX TEMPS SHOULD BE CLOSE TO SEASONAL NORMALS WITH PLENTY OF UPR 60S TO LWR 70S. THIS WEAK SHORTWAVE TROF PUSHES ACROSS WI WITH ITS PASSING CLOUDS SUNDAY NGT...THEN THE MODELS BRING RISING UPR HEIGHTS INTO THE REGION ON MON AS SOUTHERLY WINDS TO PREVAIL. MORE SUNSHINE ON MON WL HELP NUDGE TEMPS UP A TAD WITH READINGS RANGING FROM AROUND 70 DEGS TO THE LWR 70S. QUIET WEATHER CONDITIONS TO PREVAIL THRU TUE WITH UPR RIDGING OVER THE WRN GREAT LAKES. MODELS DO SHOW A MODEST CDFNT PUSHING ACROSS THE UPR MS VALLEY ON TUE...BUT BE TOO FAR AWAY YET TO IMPACT OUR WEATHER. LOOK FOR MAX TEMPS TUE TO RANGE FROM THE UPR 60S NEAR LAKE MI...TO THE LWR TO MID 70S OVER PARTS OF CNTRL WI. THE MOVEMENT OF THIS CDFNT WL ULTIMATELY DETERMINE WHEN TO PLACE THE NEXT CHC FOR SHWRS/TSTMS INTO THE FCST. FULLY ANTICIPATE THE MODELS TO WAFFLE ON NOT ONLY THE LOCATION OF THE FNT...BUT ALSO HOW MUCH MOISTURE WL BE AVAILABLE WHEN THE FNT DOES ARRIVE. HAVE FOLLOWED THE CONSENSUS SOLUTION FOR NOW WHICH ONLY BRINGS A MINIMAL POP TO N-CNTRL WI TUE NGT AND WED. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 1149 AM CDT THU SEP 17 2015 AN ACTIVE PERIOD OF WEATHER WILL MOVE ACROSS THE REGION THROUGH THE END OF THE TAF PERIOD. SHOWERS AND STORMS WILL IMPACT CENTRAL AND NORTH-CENTRAL WISCONSIN THROUGH EARLY THIS AFTERNOON. NOT SURE HOW FAR EAST THESE STORMS WILL MAKE IT...DUE TO A MORE STABLE AIRMASS IN THE EASTERN PART OF THE STATE. ONCE THIS FIRST ROUND EXITS/DIMINISHES...A SECOND ROUND OF STORMS IS ANTICIPATED TO MOVE ACROSS THE REGION LATE THIS AFTERNOON THROUGH THE EVENING. STRONG GUSTY WINDS AND HEAVY RAIN WILL BE POSSIBLE IN ANY STORMS. IN THE WAKE OF THESE STORMS...CIGS/VSBYS WILL LOWER TO IFR/LIFR ALONG THE COLD FRONT. SOME IMPROVEMENT IS EXPECTED FRIDAY MORNING. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TDH LONG TERM......KALLAS AVIATION.......MPC
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1117 AM CDT THU SEP 17 2015 .UPDATE... SCATTERED SHOWERS AND THUNDERSTORMS ARE SPREADING INTO WESTERN WISCONSIN LATE THIS MORNING IN RESPONSE TO WEAK 925-700MB WARM AIR ADVECTION AND STEADY MOISTURE TRANSPORT. THE LATEST 14Z HRRR MODEL SHOWS THIS CONVECTION TRACKING EAST THROUGH SOUTHERN WI THROUGH EARLY AFTERNOON. THIS MAY PAN OUT GRADUALLY OVER TIME... BUT THE CONVECTION IS GETTING EATEN BY DRY AIR AS IT WORKS EAST LATE THIS MORNING. THE INSTABILITY AND MOISTURE WILL NEED TIME TO SPREAD EAST TODAY TO SUPPORT CONVECTION. CAPE VALUES ARE BETWEEN 500 AND 1000 J/KG IN WESTERN/SOUTH CENTRAL WI. LOW LEVEL SHEAR IS DECENT BUT BULK SHEAR IS WEAK SO NOT EXPECTING SEVERE WITH THESE BRIEF THUNDERSTORMS. THE MAIN EVENT WILL ARRIVE THIS EVENING AS A LINE OF CONVECTION IS EXPECTED TO SLIDE SOUTHEAST THROUGH WI WITH A COLD FRONT. THERE IS A SLIGHT RISK FOR SEVERE WEATHER NORTHWEST OF MADISON AND A MARGINAL RISK ELSEWHERE. && .AVIATION/18Z TAFS/... GUSTY SOUTH WINDS AGAIN TODAY WITH GUSTS TO 20-25 KNOTS. SHOWERS AND THUNDERSTORMS TRACKING INTO SOUTH CENTRAL WI ARE DISSIPATING AS THEY HEAD EAST OF MADISON DUE TO DRY AIR. THE ENVIRONMENT WILL GET BETTER FOR SUPPORTING CONVECTION FARTHER EAST LATER IN THE AFTERNOON. EXPECT CHANCE OF SHOWERS AND THUNDERSTORMS FOR MUCH OF THE DAY. THUNDERSTORM CHANCES INCREASE LATE THIS AFTERNOON AND EVENING WITH THE APPROACH OF SURFACE COLD FRONT. EXPECT MVFR VSBYS IN THE STORMS...WITH SOME STRONG WIND GUSTS AND HAIL POSSIBLE OVER MAINLY SOUTH CENTRAL WISCONSIN LATE THIS AFTERNOON AND EVENING. WILL SEE MVFR CIGS FRIDAY MORNING BEHIND PCPN WITH THE COLD AIR ADVECTION BEHIND THE FRONT. && .PREV DISCUSSION... /ISSUED 657 AM CDT THU SEP 17 2015/ TODAY...FORECAST CONFIDENCE MEDIUM TWO AREAS OF CONVECTION ONGOING...THE FIRST NARROW BAND OF SHOWERS AND THUNDERSTORMS IN ERN MN/WRN WI DRIVEN BY 850-700 MB WARM AIR ADVECTION/MOISTURE TRANSPORT AS WELL AS CVA WITH LEAD SHORT WAVE UNDER INCREASING 250 MB UPPER LEVEL DIVERGENCE. SECOND AREA IN THE DAKOTAS IS WITH FORCING ASSOCIATED WITH MAIN SHORT WAVE TROUGH AND SURFACE LOW. UPPER LEVEL DIVERGENCE/DIFFLUENCE INCREASES THIS AFTERNOON AS IT SHIFTS EAST AHEAD OF APPROACHING UPPER TROUGH...WITH A LEAD SHORT WAVE REACHING LAKE MICHIGAN BY 00Z. HOWEVER 700 MB OMEGA WEAKENS AROUND 18Z IN AREA OF 850 MB DIVERGENCE AS STRONGEST 850 MB WINDS SPLIT... WITH ONE MAX LIFTING OFF TO THE NORTH OVER THE U.P. AND LAKE SUPERIOR AND A SECOND MAX APPROACHES FROM MISSOURI AHEAD OF THE MAIN TROUGH. NAM ACTUALLY SHOWING SUBSIDENCE OVER SRN WI DURING THE AFTERNOON...WHICH EXPLAINS THE LACK OF QPF OVER THE FORECAST AREA. WILL FOLLOW CONSENSUS BLEND WHICH BRINGS INITIAL WAA PCPN INTO SOUTH CENTRAL WI THIS MORNING THEN LIFTS IT NORTH...WITH REDEVELOPMENT TO THE SOUTHWEST AHEAD OF NEXT WARM...MOIST SURGE THIS AFTERNOON... KEEPING MOST OF SOUTHEAST WISCONSIN DRY. CLOUDS...AND THIS FIRST ROUND OF PCPN WILL KEEP HIGH TEMPS A BIT LOWER IN THE WEST THAN THAT PAST FEW DAYS BUT WILL STILL REACH 80 MOST LOCATIONS WITH THE WARMEST TEMPS IN THE SOUTHEAST. THOUGH 850 MB WINDS LOWER...WILL STILL MIX UP TO AROUND 900 MB AND 20-25 KT WINDS SO IT WILL BE BREEZY AGAIN THIS AFTERNOON. TONIGHT...FORECAST CONFIDENCE MEDIUM. SHOWERS AND THUNDERSTORMS WILL REDEVELOP TONIGHT AS COLD FRONT/SURFACE TROUGH MOVES INTO THE REGION. PRECIPITABLE WATER VALUES REACH 1.8 TO 1.9 INCHES FOR TONIGHT WITH MOISTURE TRANSPORT RIDING IN ON 30-40KT LOW LEVEL JET AHEAD OF APPROACHING .WITH MOST-UNSTABLE CAPE VALUES OF 1000-1300 J/KG. COULD SEE SOME HEAVY RAIN TONIGHT...WITH SOUTH CENTRAL POSSIBLY SEEING 3/4 INCH TO 1 INCH AND THE SOUTHEAST WIDESPREAD 1/2 INCH AMOUNTS BY FRIDAY MORNING...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. FORTUNATELY FLASH FLOOD GUIDANCE IS HIGH WITH 1-HOURLY THRESHOLDS AROUND 2 INCHES AND 3 TO 6-HOURLY BETWEEN 2.5 AND 3 INCHES. DEEP LAYER SHEAR DOES RISE TO 25-30 KNOTS SO POTENTIAL IS THERE FOR ROTATING CELLS THAT COULD PRODUCE HAIL AND STRONG WIND GUSTS. SPC HAS MOST OF SOUTH CENTRAL IN A SLIGHT RISK...MAINLY DURING PERIOD OF MAXIMUM INSTABILITY FOR LATE THIS AFTERNOON AND EVENING...AND THE REST OF SOUTHERN WISCONSIN IN A MARGINAL RISK FOR SEVERE. FRIDAY AND SATURDAY...FORECAST CONFIDENCE...MEDIUM THE COLD FRONT IS EXPECTED TO STALL FRIDAY IN THE VICINITY OF THE WI/IL BORDER. MEANWHILE...ANOTHER SURFACE LOW WILL TAKE AIM AT THE AREA...MOVING THROUGH THE STALLED FRONTAL ZONE FRIDAY NIGHT AHEAD OF A STRONG SHORTWAVE. THINK THAT THERE MAY BE A FEW LINGERING SHOWERS/STORMS EARLY FRIDAY FROM THE FRONTAL PASSAGE...WITH IT POSSIBLY TURNING DRY FOR A TIME MID MORNING INTO EARLY AFTERNOON. MAY SEE A FEW MID/LATE AFTERNOON STORMS AS INSTABILITY INCREASES...THOUGH BULK OF FORCING NOT SET TO ARRIVE UNTIL THE EVENING AND OVERNIGHT HOURS. MODELS STILL STRUGGLING WITH THE PATH/SPEED OF THE STRONG SURFACE LOW FRIDAY NIGHT. THE GFS HAS IT OVER THE SOUTHERN TIP OF LAKE MICHIGAN AT DAYBREAK SATURDAY...WITH THE NAM PUTTING THE CENTER OF THE LOW OVER THE WESTERN FORECAST AREA. MEANWHILE...THE ECMWF AND CANADIAN HAVE THE LOW OVER EASTERN LOWER MICHIGAN. FOR NOW...STUCK CLOSE TO THE ECMWF/CANADIAN SOLUTIONS...WHICH HAVE BEEN PRETTY CONSISTENT THE LAST COUPLE DAYS. EITHER WAY...LOOKS LIKE A WET EVENING AND NIGHT WITH WIDESPREAD RAINFALL EXPECTED. BEST CHANCE FOR CONVECTION IN THE SOUTHEAST FORECAST AREA...AS THE WARM SECTOR AND BETTER INSTABILITY TRY TO SNEAK IN. MODELS STILL GENERALLY PAINTING OUT 0.5 TO 1.O INCH OF RAIN OVERNIGHT. HAVE POPS LINGERING INTO SATURDAY MORNING...MAINLY IGNORING NAM FOR NOW...WHICH WOULD LINGER RAIN MUCH OF THE DAY. SHOULD BE DRY BY LATE MORNING OR EARLY AFTERNOON AS HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. THOUGH THE SURFACE FRONT IS PROGGED TO BE MAINLY SOUTH OF MUCH OF THE FORECAST AREA BY LATE MORNING FRIDAY...MODELS STILL SHOWING PRETTY MILD TEMPS AT 925 MB. KEPT HIGHS CLOSER TO MODEL 2M TEMPS THOUGH...AS IT WILL PROBABLY BE HARD TO TAP THOSE WARMER TEMPS GIVEN THE POSITION OF THE FRONT...ALONG WITH CLOUDS AND PRECIP CHANCES. WILL BE COOLER THEN SATURDAY IN THE WAKE OF THE DEPARTING LOW. SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...HIGH MODELS IN PRETTY GOOD AGREEMENT THAT HIGH PRESSURE WILL BE OVERHEAD FOR SUNDAY THROUGH WEDNESDAY. LOOKS LIKE PLENTY OF SUNSHINE WITH HIGH TEMPS WARMING BACK TO AROUND OR A LITTLE ABOVE AVERAGE VALUES FOR THE LAST COUPLE DAYS OF SUMMER. AVIATION/12Z TAFS... NARROW BAND OF SHOWERS AND THUNDERSTORMS OVER FAR WESTERN WISCONSIN EARLY THIS MORNING IS DIMINISHING AS LOW-LEVEL JET MOVES TO THE NORTH. WILL WATCH SHOWERS AND STORMS IN IOWA APPROACHING WITH A WEAK WAVE...BUT EXPECT VFR CONDITIONS THROUGH THE MORNING AND EARLY AFTERNOON. GUSTY SOUTH WINDS AGAIN TODAY WITH GUSTS TO 20-25 KNOTS. SHOWER AND STORM CHANCES INCREASE LATE THIS AFTERNOON AND EVENING WITH THE APPROACH OF SURFACE COLD FRONT. EXPECT MVFR VSBYS IN THE STORMS...WITH SOME STRONG WIND GUSTS AND HAIL POSSIBLE OVER MAINLY SOUTH CENTRAL WISCONSIN LATE THIS AFTERNOON AND EVENING. WILL SEE MVFR CIGS FRIDAY MORNING BEHIND PCPN WITH THE COLD AIR ADVECTION BEHIND THE FRONT. MARINE... SOUTH WINDS AGAIN INCREASE TO 10 TO 20 KNOTS BY LATE MORNING....WITH GUSTS TO 25 KNOTS FREQUENT ENOUGH FROM PORT WASHINGTON NORTH TO KEEP SMALL CRAFT ADVISORY AS IS. WINDS AND WAVES MARGINAL SOUTH OF PORT WASHINGTON. LOOKING FOR THUNDERSTORMS TO REACH THE NEARSHORE WATERS BY EARLY EVENING AHEAD OF A COLD FRONT. SOME STORMS COULD PRODUCE STRONG WIND GUSTS AND HAIL. BEACHES... WITH SOUTH WINDS OF 15 TO 25 KNOTS AND WAVES OF 3 TO 5 FEET HAVE ISSUED A BEACH HAZARD STATEMENT FOR THE BEACHES OF SHEBOYGAN COUNTY TO LINE UP WITH THE SMALL CRAFT ADVISORY. HAZARDOUS CONDITIONS WILL LINGER INTO THE EVENING BEFORE WINDS AND WAVES LOWER. A MODERATE SWIM RISK WILL EXIST AT THE LAKE MICHIGAN BEACHES FROM OZAUKEE COUNTY SOUTH THROUGH KENOSHA COUNTY FROM MID MORNING THROUGH EARLY EVENING. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...BEACH HAZARDS STATEMENT UNTIL 10 PM CDT THIS EVENING FOR WIZ052. LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643. && $$ UPDATE...MRC TODAY/TONIGHT AND AVIATION/MARINE...REM FRIDAY THROUGH WEDNESDAY...DDV
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
608 AM CDT THU SEP 17 2015 UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND FRIDAY ISSUED AT 310 AM CDT THU SEP 17 2015 FORECAST CHALLENGE CENTERS ON CONVECTION TRENDS TODAY INTO TONIGHT AND SEVERE POTENTIAL. AREA RADARS SHOW LEAD CONVECTION EARLY THIS MORNING NEAR THE MINNESOTA WISCONSIN BORDER IN THE LLJ REGION...HIGHER PWATS AND 850 MB WARM AIR ADVECTION. THIS FOCUS OF CONVECTION WILL GRADUALLY SHIFT EASTWARD TODAY BUT MAY DIMINISH FOR A PERIOD LATER THIS MORNING. A COLD FRONT AND MID LEVEL TROUGH WITH EVEN MORE CONVECTION WAS OVER THE NORTHERN PLAINS AND APPROACHING THE WESTERN GREAT LAKES REGION TODAY. SHOWERS AND STORMS WILL LIKELY BECOME MORE WIDESPREAD BY THIS AFTERNOON OVER WESTERN WISCONSIN AND THEN TOWARD EASTERN AREAS BY THIS EVENING AS THE INITIAL CONVECTION MERGES WITH THE WITH THE APPROACHING NORTHERN PLAINS SYSTEM. HRRR MODEL KEEPS THE LEAD WARM SECTOR CONVECTION AND THE FRONTAL CONVECTION A BIT MORE SEPARATE. BLEND OF MODEL RUNS SUGGEST A FASTER DEPARTURE TOWARD FRIDAY MORNING...WITH PERHAPS A BREAK IN PCPN FOR MUCH OF FRIDAY. PCPN BEGINS TO SPREAD BACK INTO THE AREA FROM SOUTHWEST TO NORTHEAST AS A SURFACE WAVE TRACKS ALONG THE FRONTAL BOUNDARY SOUTH OF THE AREA. THE NORTHERN AREAS ARE EXPECTED TO BE OVERALL DRY ON FRIDAY. LIFT WITH THE RRQ REGION OF THE UPPER JET NOT EXPECTED TO AFFECT THE AREA UNTIL AFTER FRIDAY AFTERNOON. AS FAR AS SEVERE POTENTIAL. BEST ML CAPE VALUES OCCUR THIS AFTERNOON OVER THE WEST HALF OF THE STATE INCLUDING CENTRAL AND NORTH CENTRAL WISCONSIN AND TOWARD EARLY EVENING OVER EASTERN AREAS. SHEAR WILL BE ON THE INCREASE THIS AFTERNOON AND EARLY EVENING AS MID LEVEL WINDS INCREASE AND TURN MORE WSW AS A MID LEVEL TROUGH OF LOW PRESSURE SLIDES ALONG THE US/CANADA BORDER. THESE LIKELY STRONGER WINDS ALOFT WILL INTERACT WITH THE SOUTH FLOW IN THE BOUNDARY LAYER AHEAD OF THE FRONT. THIS INCREASE IN SHEAR AND INSTABILITY WILL PRODUCE A WINDOW OF SEVERE POTENTIAL...BUT THE STRONGER WINDS ALOFT MAY ALSO PUSH THE STORMS EASTWARD FASTER OVERNIGHT. THE PRIMARY ISSUE WILL BE HEAVY RAIN DUE TO HIGHER PWATS AND DAMAGING WINDS. HAIL POSSIBLE WITH ANY SUPER STORM DEVELOPMENT IN THE SHEARED ENVIRONMENT BUT PROGGED FORECAST SOUNDINGS INDICATE WBZ START TO FALL BELOW 10000 FEET WELL AFTER THE FROPA AND CONVECTION. AMOUNT OF CLOUDS TODAY WILL OBVIOUSLY AFFECT AVAILABLE INSTABILITY. SPC HAS PAINTED A SLIGHT RISK DAY 1 TODAY OVER ALL OF CENTRAL WISCONSIN AND PARTS OF NORTH CENTRAL AND NORTHEAST WISCONSIN. LAST DAY OF ABOVE NORMAL TEMPERATURES THIS WEEK FOR TODAY FOLLOWED WITH NEAR NORMAL TEMPERATURES ON FRIDAY IN THE WAKE OF THE COLD FRONT. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY ISSUED AT 310 AM CDT THU SEP 17 2015 A WET START TO THE EXTENDED FCST AS A STRENGTHENING SFC LOW RIDES NE THRU THE GREAT LAKES...TRAILED BY A STRONG SHORTWAVE TROF. ONCE THIS SYSTEM CLEARS...MEAN FLOW TO BE DOMINATED BY A STRONG BAND OF WESTERLIES RUNNING FROM THE PAC NW E-EN INTO S-CNTRL CANADA. THIS KEEPS MOST WEATHER SYSTEMS TO OUR NW FOR THE FIRST HALF OF NEXT WEEK WITH TEMPS HOVERING NEAR OR SLIGHTLY ABOVE NORMAL. MODELS CONT TO BATTLE WITH THE INTERACTION OF A STRENGTHENING AREA OF LOW PRES RIDING NE ALONG THE CDFNT AND THE APPROACH OF A STRONG SHORTWAVE TROF/EMBEDDED SHORTWAVES FRI NGT. THE NAM REMAINS STRONGEST/FARTHEST WEST WITH THE TRACK OF THE SFC LOW...ALTHO THE ECMWF HAS TRENDED CLOSER TO THE NAM SOLUTION THAN 24 HOURS AGO. THE GFS/GEM ARE WEAKER/BIT FARTHER EAST WITH THE LOW TRACK. MODELS DO AGREE ON TWO MAIN AREAS OF PCPN WITH ONE STAYING TO OUR SOUTH ASSOCIATED WITH STRONG ISEN LIFT AND THE OTHER MOVING THRU WI ASSOCIATED WITH THE PRIMARY DEFORMATION ZONE. DESPITE THE MODEL DIFFERENCES...IT APPEARS THAT THE SE HALF OF WI COULD RECEIVE A HEALTHY RAINFALL FRI NGT WITH LOCALLY HEAVY RAINS POSSIBLE. MIN TEMPS TO RANGE FROM THE 45-50 DEG RANGE NORTH...LWR TO MID 50S SOUTH. THE BIGGER FCST ISSUE MAY ACTUALLY BE WHEN TO END THE PCPN CHCS ON SAT AS THE SLOWER NAM WOULD KEEP SHWRS GOING ALL DAY AS OPPOSED TO THE SHWRS ENDING BY MIDDAY ON THE OTHER MODELS. HAVE CONTINUED TO LEAN TOWARD THE MAJORITY SOLUTION MAINLY DUE TO THE PROGRESSIVE NATURE OF THE MEAN FLOW. THEREFORE...WL KEEP POPS IN THE FCST THRU SAT MORNING AND TREND TOWARD DECREASING CLOUDS IN THE AFTERNOON. MAX TEMPS ARE EXPECTED TO DIP SLIGHTLY BELOW NORMAL WITH READINGS GENERALLY IN THE LWR TO MID 60S NORTH...MID TO UPR 60S SOUTH. HI PRES IS FCST TO MOVE EAST FROM THE CNTRL PLAINS TOWARD SRN SECTIONS OF THE GREAT LAKES SAT NGT. MOSTLY CLEAR TO PARTLY CLOUDY SKIES...LIGHT WINDS AND A DRIER AIR MASS WL ALLOW FOR TEMPS TO FALL TO AROUND 40 DEGS OVER THE COLDER LOCATIONS OF THE NORTHWOODS...AROUND 50 DEGS ALONG LAKE MI. DEPENDING ON HOW MUCH RAIN FALLS FRI NGT/SAT MORNING...THERE COULD BE PATCHY FOG DEVELOPING JUST ABOUT ANYWHERE OVER NE WI. THE SFC HI WL DRIFT ACROSS THE GREAT LAKES ON SUNDAY WITH A RETURN FLOW DEVELOPING OVER WI. IN ADDITION...MODELS SUGGEST A WEAK SHORTWAVE TROF WL APPROACH THE GREAT LAKES SUNDAY AFTERNOON. THERE IS NOT ENUF LIFT/ FORCING/MOISTURE FOR ANY PCPN TO DEVELOP...HOWEVER WE MAY SEE SOME CLOUDS PUSH INTO THE FCST AREA THROUGHOUT THE DAY. MAX TEMPS SHOULD BE CLOSE TO SEASONAL NORMALS WITH PLENTY OF UPR 60S TO LWR 70S. THIS WEAK SHORTWAVE TROF PUSHES ACROSS WI WITH ITS PASSING CLOUDS SUNDAY NGT...THEN THE MODELS BRING RISING UPR HEIGHTS INTO THE REGION ON MON AS SOUTHERLY WINDS TO PREVAIL. MORE SUNSHINE ON MON WL HELP NUDGE TEMPS UP A TAD WITH READINGS RANGING FROM AROUND 70 DEGS TO THE LWR 70S. QUIET WEATHER CONDITIONS TO PREVAIL THRU TUE WITH UPR RIDGING OVER THE WRN GREAT LAKES. MODELS DO SHOW A MODEST CDFNT PUSHING ACROSS THE UPR MS VALLEY ON TUE...BUT BE TOO FAR AWAY YET TO IMPACT OUR WEATHER. LOOK FOR MAX TEMPS TUE TO RANGE FROM THE UPR 60S NEAR LAKE MI...TO THE LWR TO MID 70S OVER PARTS OF CNTRL WI. THE MOVEMENT OF THIS CDFNT WL ULTIMATELY DETERMINE WHEN TO PLACE THE NEXT CHC FOR SHWRS/TSTMS INTO THE FCST. FULLY ANTICIPATE THE MODELS TO WAFFLE ON NOT ONLY THE LOCATION OF THE FNT...BUT ALSO HOW MUCH MOISTURE WL BE AVAILABLE WHEN THE FNT DOES ARRIVE. HAVE FOLLOWED THE CONSENSUS SOLUTION FOR NOW WHICH ONLY BRINGS A MINIMAL POP TO N-CNTRL WI TUE NGT AND WED. && .AVIATION...FOR 12Z TAF ISSUANCE ISSUED AT 608 AM CDT THU SEP 17 2015 ISOLATED SHOWERS AND STORMS MAY BRUSH OVER FAR NORTH CENTRAL WISCONSIN OR AREAS NORTHWEST OF RHI THIS MORNING...OTHERWISE VFR CONDITIONS FOR MUCH OF THE AREA FOR THE START OF TODAY. LLWS CONDITIONS WILL LINGER THIS MORNING BEFORE GUSTY SOUTH SURFACE WINDS DEVELOP. SHOWERS AND STORMS ALONG WITH SCATTERED MVFR CONDITIONS WILL BE ON THE INCREASE TODAY AND EVENING THEN DIMINISHING FROM WEST TO EAST LATE TONIGHT. SOME STRONG OR SEVERE STORMS ARE POSSIBLE IN THE AFTERNOON AND EARLY EVENING. OVERNIGHT...AREAS OF IFR CIGS/VSBYS MAY BE DEVELOPING ALONG AND IN THE WAKE OF THE COLD FRONT. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TDH LONG TERM......KALLAS AVIATION.......TDH
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND FRIDAY ISSUED AT 310 AM CDT THU SEP 17 2015 FORECAST CHALLENGE CENTERS ON CONVECTION TRENDS TODAY INTO TONIGHT AND SEVERE POTENTIAL. AREA RADARS SHOW LEAD CONVECTION EARLY THIS MORNING NEAR THE MINNESOTA WISCONSIN BORDER IN THE LLJ REGION...HIGHER PWATS AND 850 MB WARM AIR ADVECTION. THIS FOCUS OF CONVECTION WILL GRADUALLY SHIFT EASTWARD TODAY BUT MAY DIMINISH FOR A PERIOD LATER THIS MORNING. A COLD FRONT AND MID LEVEL TROUGH WITH EVEN MORE CONVECTION WAS OVER THE NORTHERN PLAINS AND APPROACHING THE WESTERN GREAT LAKES REGION TODAY. SHOWERS AND STORMS WILL LIKELY BECOME MORE WIDESPREAD BY THIS AFTERNOON OVER WESTERN WISCONSIN AND THEN TOWARD EASTERN AREAS BY THIS EVENING AS THE INITIAL CONVECTION MERGES WITH THE WITH THE APPROACHING NORTHERN PLAINS SYSTEM. HRRR MODEL KEEPS THE LEAD WARM SECTOR CONVECTION AND THE FRONTAL CONVECTION A BIT MORE SEPARATE. BLEND OF MODEL RUNS SUGGEST A FASTER DEPARTURE TOWARD FRIDAY MORNING...WITH PERHAPS A BREAK IN PCPN FOR MUCH OF FRIDAY. PCPN BEGINS TO SPREAD BACK INTO THE AREA FROM SOUTHWEST TO NORTHEAST AS A SURFACE WAVE TRACKS ALONG THE FRONTAL BOUNDARY SOUTH OF THE AREA. THE NORTHERN AREAS ARE EXPECTED TO BE OVERALL DRY ON FRIDAY. LIFT WITH THE RRQ REGION OF THE UPPER JET NOT EXPECTED TO AFFECT THE AREA UNTIL AFTER FRIDAY AFTERNOON. AS FAR AS SEVERE POTENTIAL. BEST ML CAPE VALUES OCCUR THIS AFTERNOON OVER THE WEST HALF OF THE STATE INCLUDING CENTRAL AND NORTH CENTRAL WISCONSIN AND TOWARD EARLY EVENING OVER EASTERN AREAS. SHEAR WILL BE ON THE INCREASE THIS AFTERNOON AND EARLY EVENING AS MID LEVEL WINDS INCREASE AND TURN MORE WSW AS A MID LEVEL TROUGH OF LOW PRESSURE SLIDES ALONG THE US/CANADA BORDER. THESE LIKELY STRONGER WINDS ALOFT WILL INTERACT WITH THE SOUTH FLOW IN THE BOUNDARY LAYER AHEAD OF THE FRONT. THIS INCREASE IN SHEAR AND INSTABILITY WILL PRODUCE A WINDOW OF SEVERE POTENTIAL...BUT THE STRONGER WINDS ALOFT MAY ALSO PUSH THE STORMS EASTWARD FASTER OVERNIGHT. THE PRIMARY ISSUE WILL BE HEAVY RAIN DUE TO HIGHER PWATS AND DAMAGING WINDS. HAIL POSSIBLE WITH ANY SUPER STORM DEVELOPMENT IN THE SHEARED ENVIRONMENT BUT PROGGED FORECAST SOUNDINGS INDICATE WBZ START TO FALL BELOW 10000 FEET WELL AFTER THE FROPA AND CONVECTION. AMOUNT OF CLOUDS TODAY WILL OBVIOUSLY AFFECT AVAILABLE INSTABILITY. SPC HAS PAINTED A SLIGHT RISK DAY 1 TODAY OVER ALL OF CENTRAL WISCONSIN AND PARTS OF NORTH CENTRAL AND NORTHEAST WISCONSIN. LAST DAY OF ABOVE NORMAL TEMPERATURES THIS WEEK FOR TODAY FOLLOWED WITH NEAR NORMAL TEMPERATURES ON FRIDAY IN THE WAKE OF THE COLD FRONT. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY ISSUED AT 310 AM CDT THU SEP 17 2015 A WET START TO THE EXTENDED FCST AS A STRENGTHENING SFC LOW RIDES NE THRU THE GREAT LAKES...TRAILED BY A STRONG SHORTWAVE TROF. ONCE THIS SYSTEM CLEARS...MEAN FLOW TO BE DOMINATED BY A STRONG BAND OF WESTERLIES RUNNING FROM THE PAC NW E-EN INTO S-CNTRL CANADA. THIS KEEPS MOST WEATHER SYSTEMS TO OUR NW FOR THE FIRST HALF OF NEXT WEEK WITH TEMPS HOVERING NEAR OR SLIGHTLY ABOVE NORMAL. MODELS CONT TO BATTLE WITH THE INTERACTION OF A STRENGTHENING AREA OF LOW PRES RIDING NE ALONG THE CDFNT AND THE APPROACH OF A STRONG SHORTWAVE TROF/EMBEDDED SHORTWAVES FRI NGT. THE NAM REMAINS STRONGEST/FARTHEST WEST WITH THE TRACK OF THE SFC LOW...ALTHO THE ECMWF HAS TRENDED CLOSER TO THE NAM SOLUTION THAN 24 HOURS AGO. THE GFS/GEM ARE WEAKER/BIT FARTHER EAST WITH THE LOW TRACK. MODELS DO AGREE ON TWO MAIN AREAS OF PCPN WITH ONE STAYING TO OUR SOUTH ASSOCIATED WITH STRONG ISEN LIFT AND THE OTHER MOVING THRU WI ASSOCIATED WITH THE PRIMARY DEFORMATION ZONE. DESPITE THE MODEL DIFFERENCES...IT APPEARS THAT THE SE HALF OF WI COULD RECEIVE A HEALTHY RAINFALL FRI NGT WITH LOCALLY HEAVY RAINS POSSIBLE. MIN TEMPS TO RANGE FROM THE 45-50 DEG RANGE NORTH...LWR TO MID 50S SOUTH. THE BIGGER FCST ISSUE MAY ACTUALLY BE WHEN TO END THE PCPN CHCS ON SAT AS THE SLOWER NAM WOULD KEEP SHWRS GOING ALL DAY AS OPPOSED TO THE SHWRS ENDING BY MIDDAY ON THE OTHER MODELS. HAVE CONTINUED TO LEAN TOWARD THE MAJORITY SOLUTION MAINLY DUE TO THE PROGRESSIVE NATURE OF THE MEAN FLOW. THEREFORE...WL KEEP POPS IN THE FCST THRU SAT MORNING AND TREND TOWARD DECREASING CLOUDS IN THE AFTERNOON. MAX TEMPS ARE EXPECTED TO DIP SLIGHTLY BELOW NORMAL WITH READINGS GENERALLY IN THE LWR TO MID 60S NORTH...MID TO UPR 60S SOUTH. HI PRES IS FCST TO MOVE EAST FROM THE CNTRL PLAINS TOWARD SRN SECTIONS OF THE GREAT LAKES SAT NGT. MOSTLY CLEAR TO PARTLY CLOUDY SKIES...LIGHT WINDS AND A DRIER AIR MASS WL ALLOW FOR TEMPS TO FALL TO AROUND 40 DEGS OVER THE COLDER LOCATIONS OF THE NORTHWOODS...AROUND 50 DEGS ALONG LAKE MI. DEPENDING ON HOW MUCH RAIN FALLS FRI NGT/SAT MORNING...THERE COULD BE PATCHY FOG DEVELOPING JUST ABOUT ANYWHERE OVER NE WI. THE SFC HI WL DRIFT ACROSS THE GREAT LAKES ON SUNDAY WITH A RETURN FLOW DEVELOPING OVER WI. IN ADDITION...MODELS SUGGEST A WEAK SHORTWAVE TROF WL APPROACH THE GREAT LAKES SUNDAY AFTERNOON. THERE IS NOT ENUF LIFT/ FORCING/MOISTURE FOR ANY PCPN TO DEVELOP...HOWEVER WE MAY SEE SOME CLOUDS PUSH INTO THE FCST AREA THROUGHOUT THE DAY. MAX TEMPS SHOULD BE CLOSE TO SEASONAL NORMALS WITH PLENTY OF UPR 60S TO LWR 70S. THIS WEAK SHORTWAVE TROF PUSHES ACROSS WI WITH ITS PASSING CLOUDS SUNDAY NGT...THEN THE MODELS BRING RISING UPR HEIGHTS INTO THE REGION ON MON AS SOUTHERLY WINDS TO PREVAIL. MORE SUNSHINE ON MON WL HELP NUDGE TEMPS UP A TAD WITH READINGS RANGING FROM AROUND 70 DEGS TO THE LWR 70S. QUIET WEATHER CONDITIONS TO PREVAIL THRU TUE WITH UPR RIDGING OVER THE WRN GREAT LAKES. MODELS DO SHOW A MODEST CDFNT PUSHING ACROSS THE UPR MS VALLEY ON TUE...BUT BE TOO FAR AWAY YET TO IMPACT OUR WEATHER. LOOK FOR MAX TEMPS TUE TO RANGE FROM THE UPR 60S NEAR LAKE MI...TO THE LWR TO MID 70S OVER PARTS OF CNTRL WI. THE MOVEMENT OF THIS CDFNT WL ULTIMATELY DETERMINE WHEN TO PLACE THE NEXT CHC FOR SHWRS/TSTMS INTO THE FCST. FULLY ANTICIPATE THE MODELS TO WAFFLE ON NOT ONLY THE LOCATION OF THE FNT...BUT ALSO HOW MUCH MOISTURE WL BE AVAILABLE WHEN THE FNT DOES ARRIVE. HAVE FOLLOWED THE CONSENSUS SOLUTION FOR NOW WHICH ONLY BRINGS A MINIMAL POP TO N-CNTRL WI TUE NGT AND WED. && .AVIATION...FOR 06Z TAF ISSUANCE ISSUED AT 1054 PM CDT WED SEP 16 2015 SHOULD BE MAINLY VFR TONIGHT THOUGH SOME SHOWERS ARE NOT OUT OF THE QUESTION OVER THE NORTH. LOW LEVEL WIND SHEAR IS LIKELY WITH SOUTHWEST WINDS AROUND 35 KNOTS AT 1000` AGL AND LIGHT SOUTH SURFACE WINDS. THURSDAY WILL BE CLOUDY WITH SHOWERS AND THUNDERSTORMS ARRIVING FROM THE WEST DURING THE LATE MORNING AND AFTERNOON. SOME STRONG OR SEVERE STORMS ARE POSSIBLE IN THE AFTERNOON. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TDH LONG TERM......KALLAS AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1124 PM MDT FRI SEP 18 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 208 PM MDT FRI SEP 18 2015 ...COOLER WEATHER CONTINUES ON SATURDAY... STRETCH OF BEAUTIFUL FALL-LIKE WEATHER SHOULD CONTINUE ON SATURDAY AS HIGH PRESSURE DOMINATES AND DRY WESTERLY FLOW PERSISTS. UPSLOPE REGIME OVER THE PLAINS WILL ALLOW FOR ANOTHER DAY OF SEASONABLE TEMPS ON SATURDAY. HIGH RES MODELS INCLUDING THE HRRR CONTINUE TO INDICATE SOME ISOLD SHOWER OR TS DEVELOPING LATE THIS AFTERNOON OVER NRN TELLER COUNTY. THERE IS SOME CU OVER THAT AREA THIS AFTERNOON SO CANNOT RULE IT OUT...AND WILL LEAVE SOME LOW POPS OVER THE PIKES PEAK REGION AND ALSO OVER THE HYR TRRN IN NRN FREMONT COUNTY AND MOSQUITO RANGE THRU THIS EVENING. HAVE TRIMMED BACK POPS ELSEWHERE SINCE THE PROBABILITY LOOKS TOO LOW OVER THE ERN RANGES AND CENTRAL MTS. ANYTHING THAT GETS GOING LATER TODAY SHOULD WIND DOWN THIS EVE. THE HRRR INDICATES CONVECTION DRIFTING NWD TONIGHT...SO MAY BE ABLE TO PULL POPS OUT COMPLETELY IF THINGS DON`T DEVELOP BY EARLY EVE. OVERNIGHT...WILL BE COOL WITH CLEARING SKIES AND WINDS DIMINISHING. SOME LOWS IN THE UPR 40S POSSIBLE OVER THE PLAINS. A FEW AREAS OF LOWER CLOUDS WILL BE POSSIBLE BUT SHOULD NOT BE TOO EXTENSIVE. SATURDAY...FAIRLY SIMILAR TEMPS EXPECTED AS THE COOLER AIR REMAINS WITH US...AND SFC WINDS SHIFT AROUND TO THE SE. SHOULD TOP OUT AROUND 80 DEGREES FOR THE PLAINS...WHILE THE MTS AND HIGH VALLEYS REMAIN IN THE 60S TO LOWER 70S. A SHORT WAVE WILL MOVE THROUGH THE CENTRAL ROCKIES IN THE AFTERNOON...AND THIS COULD SPARK A FEW SHOWERS OR STORMS MAINLY OVER THE HIGHER TRRN LATE IN THE AFTERNOON...BUT NOT EXPECTING ANYTHING TOO WIDESPREAD OR HEAVY. SHOULD BE A RATHER PLEASANT FALL-LIKE DAY ACROSS THE CWA. ROSE .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 208 PM MDT FRI SEP 18 2015 A SHORTWAVE TROF MOVING THRU THE AREA SAT NIGHT MAY BRING SOME ISOLD PCPN TO LOCATIONS FROM THE ERN MTNS TO THE ERN BORDER...WHICH SHOULD END TOWARD SUN MORNING. AN UPR RIDGE WL BUILD OVR THE AREA FOR SUN AND MON WITH DRY WX EXPECTED AND ABOVE AVERAGE HIGH TEMPS. ON TUE AN UPR TROF IS EXPECTED TO MOVE OVR SRN CA AND THE SW FLOW ALOFT AHEAD OF THIS SYSTEM WL BRING AN INCREASE IN MSTR AND A CHANCE FOR PCPN TO MAINLY THE SW CO MTNS LATE IN THE AFTERNOON. THE ECMWF IS A LITTLE SLOWER BRINGING THE MSTR INTO THE AREA THAN THE GFS. TUE NIGHT AND EARLY WED A SHORTWAVE TROF MOVES ACRS CO AND WL HAVE THE POTENTIAL TO BRING ISOLD TO SCT PCPN TO MUCH OF THE FORECAST AREA. THE ECMWF SHOWS A SLOWER MOVING TROF OVR THE AREA WED AND INTO THE FIRST HALF OF THU...WITH ISOLD TO SCT PCPN CHANCES FOR MUCH OF THE AREA. LOW LEVEL UPSLOPE FLOW IS EXPECTED ON THU AND THERE MAY BE SOME SCT PCPN OVR AND NR THE MTNS AREAS. AN UPR RIDGE IS EXPECTED OVR THE AREA ON FRI. THE GFS SHOWS A MONSOON MSTR TAP INTO THE AREA FRI...WHILE THE ECMWF IS DRIER. SO THERE MAY BE SOME ISOLD TO SCT PCPN CHANCES ON FRI. IT GENERALLY LOOKS LIKE HIGH TEMPS TUE THRU FRI WL BE ABOVE AVERAGE. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1117 PM MDT FRI SEP 18 2015 VFR CONDITIONS EXPECTED NEXT 24H AT ALL 3 TAF SITES...KPUB...KALS AND KCOS. SFC WINDS WILL BE DIURNALLY DRIVEN. THERE IS A VERY LOW CHANCE OF AN ISOLD -TSRA AT KCOS AND KPUB TOMOROW AFTERNOON...BUT PROBABILITY TOO LOW TO EXPLICITLY MENTION IN TAF PRODUCT ATTM. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ROSE LONG TERM...28 AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS ALBANY NY
412 AM EDT SAT SEP 19 2015 .SYNOPSIS... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 412 AM EDT...SOME HIGH LEVEL CLOUDS HAVE MOVED INTO THE AREA EARLY THIS MORNING...WHICH ARE DEBRIS CLOUDS FROM SHOWERS THAT FELL APART TO THE WEST OF OUR REGION YESTERDAY. THE CLOUDS HAVE NOT PREVENTED TEMPERATURES FROM FALLING THOUGH...WITH 50S ACROSS MUCH OF THE AREA. THE ONLY EXCEPTION IS IN THE CAPITAL DISTRICT WHERE A SOUTHERLY BREEZE HAS KEPT TEMPS IN THE LOWER TO MID 60S. PATCHY FOG IS ALSO OCCURRING...BUT THE COVERAGE APPEARS TO BE LESS THAN YESTERDAY MORNING. CLOUDS SHOULD TEND TO THIN OUT SOMEWHAT LATER THIS MORNING...BEFORE ADDITIONAL CLOUDS INCREASE FROM THE WEST ASSOCIATED WITH A COLD FRONT APPROACHING FROM THE GREAT LAKES. ONE MORE WARM DAY IS EXPECTED...WITH SUNSHINE AND A SOUTHERLY FLOW RESULTING IN HIGH TEMPS IN THE UPPER 70S TO LOWER 80S. MOST OF THE AREA SHOULD REMAIN DRY THROUGH THE DAYLIGHT HOURS. HOWEVER...CHANCES FOR SHOWERS WILL START TO INCREASE FOR THE WESTERN ADIRONDACKS/MOHAWK VALLEY LATE IN THE DAY AS THE COLD FRONT MOVES INTO WESTERN NY. BASED ON TIMING FROM HRRR AND LOCAL HI-RES WRF...WILL ONLY MENTION 20-30 POPS FOR HERKIMER/HAMILTON COUNTIES THROUGH 6 PM TODAY. THE BULK OF THE SHOWERS WILL ARRIVE TONIGHT. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SHOWERS WILL BE MOVING INTO WESTERN PORTIONS OF THE AREA EARLY THIS EVENING...PRECEDING A COLD FRONT PUSHING EASTWARD ACROSS NY STATE. MODELS INDICATING A NARROW RIBBON OF WEAK INSTABILITY JUST AHEAD OF THE FRONT...SO WILL MENTION ISOLATED THUNDER ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. SOME BRIEF GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE LINE OF SHOWERS/STORMS FOR THIS AREA...BUT THERE WILL NOT BE ENOUGH INSTABILITY TO SUSTAIN TALL ENOUGH UPDRAFTS TO PRODUCE STRONGER WINDS. MODELS INDICATE THE LINE OF SHOWERS WILL BE WEAKENING SOMEWHAT AS THEY MOVE EAST DURING THE LATE EVENING AND OVERNIGHT HOURS. SO WILL MAINLY MENTION CHANCE POPS FOR MUCH OF THE AREA WITH LIGHT QPF AMOUNTS. THE COLD FRONT AND ANY ASSOCIATED SHOWERS SHOULD CLEAR THE ENTIRE AREA BY DAYBREAK SUNDAY. WINDS WILL BECOME NORTHERLY BEHIND THE FRONT AND WILL BE NOTICEABLE ALONG WITH COOLER TEMPERATURES. HIGHS ARE ONLY EXPECTED TO BE IN THE 60S TO NEAR 70...WHICH IS NEAR NORMAL BUT MUCH COOLER THAN RECENT DAYS. CLOUDS WILL DECREASE THROUGHOUT THE DAY AS HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE AREA. HIGH PRESSURE WILL SETTLE IN OVER THE REGION SUNDAY NIGHT INTO MONDAY MORNING...RESULTING IN CLEAR SKIES AND LIGHT WINDS. THESE CONDITIONS WILL ALLOW FOR THE COOLEST OVERNIGHT TEMPERATURES WE HAVE SEEN IN THREE MONTHS. LOWS ARE FORECAST TO BE IN THE UPPER 30S TO MID 40S...WITH PATCHY FROST POSSIBLE FOR SOME AREAS NORTH AND EAST OF ALBANY. THE LAST DAY ALBANY OFFICIALLY HAD A TEMPERATURE IN THE 40S WAS BACK ON JUNE 20TH...WHICH WAS 49 DEGREES THAT MORNING. TRANQUIL WEATHER WILL PERSIST MONDAY AND MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN CONTROL. TEMPERATURES LOOK TO BE CLOSE TO NORMAL. MONDAY NIGHT WILL LIKELY NOT BE AS COLD AS THE PREVIOUS NIGHT DUE TO SOME POSSIBLE ADDED CLOUD COVER AND A SLIGHT EASTERLY BREEZE...AS THE CENTER OF THE HIGH PRESSURE SYSTEM RETREATS TOWARDS THE CANADIAN MARITIMES. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE LONG TERM PERIOD STARTS OUT DRY AND SEASONABLE AS A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM THE OHIO VALLEY NORTHEASTWARD INTO THE NORTHEASTERN US. A WEAK COLD FRONT IS EXPECTED TO DROP SOUTHEAST FROM SOUTHERN CANADA THROUGH THE NORTHEAST ON WEDNESDAY AND STALL ACROSS THE MIDDLE ATLANTIC REGION ON THURSDAY. AT THIS TIME EXPECT THE FRONTAL PASSAGE WILL BE DRY WITH MODEL GUIDANCE INDICATING LITTLE IF ANY MOISTURE WITH THE FRONTAL BOUNDARY. FRIDAY AT THIS POINT IS A DIFFICULT FORECAST AS THE MODELS DIVERGE ON WHETHER OR NOT MOISTURE FROM THE SOUTH LIFTS NORTH WITH THE FRONTAL BOUNDARY STALLED JUST TO OUR SOUTH. AT THIS TIME THE GFS LIFTS MOISTURE NORTHWARD ACROSS OUR REGION ON FRIDAY WHILE THE ECMWF IS DRY WITH HIGH PRESSURE REMAINING IN CONTROL OF OUR WEATHER. FOR NOW WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR FRIDAY. TEMPERATURES FOR THE LONG TERM PERIOD WILL BE SEASONABLE TO SLIGHTLY BELOW NORMAL. EXPECT HIGHS TUESDAY TO BE IN THE MID 60S TO MID 70S WITH HIGHS ON WEDNESDAY AND THURSDAY IN THE UPPER 60S TO MID 70S AND HIGHS ON FRIDAY IN THE 60S TO AROUND 70 ALTHOUGH IT COULD BE COOLER IF THE GFS IS CORRECT. LOWS WILL BE IN THE 40S TO LOWER 50S TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE WILL GRADUALLY SHIFT EASTWARD TONIGHT. CONDITIONS WILL ONCE AGAIN BE FAVORABLE FOR RADIATIONAL FOG OVERNIGHT ESPECIALLY AT KPSF AND KGFL WHERE THEY ARE PRONE TO THE DEVELOPMENT OF FOG...EXPECTING IFR CONDITIONS TO OCCUR. HAVE FOG MENTIONED IN KALB AND KPOU TAF HOWEVER IS LIMITED TO MIFG SINCE THEY HAVE NOT HAD ISSUES THAT LAST COUPLE OF NIGHTS/MORNINGS. EXPECTING SOME HIGH CLOUDS TO STREAM IN AND EVENTUALLY MID CLOUDS SATURDAY AFTERNOON TO MOVE IN AHEAD AN APPROACHING COLD FRONT. THIS BOUNDARY WILL USHER A MUCH COOLER AND MORE SEASONABLE AIR MASS INTO THE REGION WITH ITS PASSAGE SATURDAY NIGHT. HAVE INCLUDED -SHRA FOR KGFL AFTER 03Z AND VCSH FOR KALB...KPSF AND KPOU BTWN 03Z AND 05Z AS SHOWERS WILL BE DIMINISHING IN COVERAGE AS THEY MOVE SOUTH AND EAST. CIGS WILL ALSO LOWER TO OVC035-050 BTWN 03Z AND 05Z. CALM WINDS FOR THE OVERNIGHT WITH A SOUTHERLY FLOW DEVELOPING SATURDAY. THE FLOW WILL PICK UP DURING THE DAY TO 8 TO 12 KNOTS WITH SOME GUSTS EXPECTED AT KGFL...KPSF AND ESPECIALLY KALB DURING THE AFTERNOON. WINDS WILL REMAIN BTWN 08-12 KTS SATURDAY EVENING BEFORE SHIFTING TO THE NORTHWEST WITH THE FRONTAL PASSAGE LATE SATURDAY NIGHT. OUTLOOK... SAT NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. SUN-WED: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. MINIMUM RELATIVE HUMIDITY VALUES TODAY WILL BE AROUND 45 TO 50 PERCENT...INCREASING TO MAXIMUM VALUES OF 85 TO 100 PERCENT TONIGHT. MIN RH VALUES ON SUNDAY ARE FORECAST TO BE BETWEEN 35 AND 45 PERCENT. WINDS TODAY WILL BE SOUTHERLY AROUND 10 TO 15 MPH...BECOMING NORTHWEST AT 5 TO 15 MPH TONIGHT AS A COLD FRONT PASSES THROUGH. WINDS ON SUNDAY WILL BECOME NORTHERLY AROUND 5 TO 15 MPH. && .HYDROLOGY... NO HYDROLOGIC CONCERNS THROUGH THE NEXT FIVE DAYS. DRY CONDITIONS WILL PERSIST THROUGH MUCH OF TODAY. A COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST TONIGHT WITH MAINLY SCATTERED SHOWERS EXPECTED. SHOWERS WILL BE MORE NUMEROUS ACROSS THE WESTERN ADIRONDACKS WHERE ONE QUARTER TO ONE THIRD OF AN INCH OF RAINFALL IS POSSIBLE. ELSEWHERE GENERALLY A TENTH OF AN INCH OR LESS IS EXPECTED. THE RAINFALL WILL HAVE LITTLE...IF ANY IMPACT ON AREA RIVERS. DRY CONDITIONS RETURN FOR SUNDAY AND WILL LIKELY LAST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH ANOTHER AREA OF HIGH PRESSURE BUILDING IN. RIVER FLOWS WILL CONTINUE TO RECEDE INTO NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...11 AVIATION...IAA/11 FIRE WEATHER...JPV HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
206 AM EDT SAT SEP 19 2015 .SYNOPSIS... HIGH PRESSURE WILL GRADUALLY SLIDE EASTWARD THROUGH TODAY. A COLD FRONT WILL MOVES THROUGH LATE TONIGHT AND SUNDAY MORNING. HIGH PRESSURE WILL THEN BUILD TO THE NORTH EARLY NEXT WEEK...AND THEN TO THE NORTHEAST INTO THE MIDDLE OF THE WEEK...WHILE LOW PRESSURE MEANDERS OFF THE SOUTHEAST COAST. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THE FORECAST REMAINS MAINLY ON TRACK. SOME PATCHY FOG HAS DEVELOPED ACROSS OF EASTERN LONG ISLAND AND EXPECT THIS TO CONTINUE THROUGH THE REST OF THE NIGHT WHERE BETTER COOLING TAKES PLACE. TEMPERATURES WERE SLIGHTLY ADJUSTED DOWN. OTHERWISE...NO OTHER REMARKABLE CHANGES MADE. THE HIGH WILL SLIDE E AND WEAKEN AS A COLD FRONT APPROACHES FROM THE WEST...AND AS LOW PRESSURE SLOWLY MOVES UP THE COAST. SKIES WILL BE CLEAR TONIGHT...AND WITH LIGHT ONSHORE FLOW CONTINUING...SHOULD SEE DEVELOPMENT OF FOG MAINLY AWAY FROM NYC LATE TONIGHT INTO EARLY SAT MORNING. LOWS IN THE VALLEYS OF ORANGE COUNTY AND THE LONG ISLAND PINE BARRENS WILL BE 55-60...WITH 60S ELSEWHERE. KEPT LOWS AROUND 60 ACROSS THE INTERIOR DESPITE AFTERNOON DEWPOINTS IN THE MID 50S SINCE AIR MASS WILL BE SLOWLY MOISTENING TONIGHT IN THE ONSHORE FLOW. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/... THE 12Z NAM AND NOW 12Z RAP ARE INDICATING AREA OF ISENTROPIC LIFT...WITH CLOUDS/SHOWERS...MOVING UP THE NJ COAST TOWARD WRN LONG ISLAND/CT AND SKIRTING NYC. NAM QPF OVERDONE BUT NOW THINK THIS IS AT LEAST WORTH A SLIGHT CHANCE MENTION FOR SAT MORNING. OTHERWISE...MOSTLY SUNNY SKIES ON SAT SHOULD LEAD TO HIGH TEMPS A COUPLE DEG HIGHER THAN COMPOSITE MOS GUIDANCE AND SIMILAR TO THOSE OF TODAY...WITH LOWER/MID 80S. A COLD FRONT WILL BEGIN TO MOVE ACROSS LATE SAT NIGHT. LIFT LOOKS WEAK AND DEEP MOISTURE IS LACKING...SO WILL CONTINUE TO CARRY SLIGHT TO LOW CHANCE POP. LOWS WILL BE MAINLY IN THE 60S. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... NORTHERN STREAM SHORTWAVE PIVOTS THROUGH SOUTHEASTERN CANADA ON SUNDAY/SUNDAY NIGHT. THEREAFTER MODELS IN FAIRLY GOOD AGREEMENT WITH A SPLIT FLOW DEVELOPING FOR EARLY TO MID NEXT WEEK AS SHORTWAVE ENERGY ENTERING THE PAC NW COAST DIGS THROUGH THE GREAT LAKES INTO THE SE US EARLY NEXT WEEK. PART OF THIS ENERGY SEPARATES ITSELF FROM THE NORTHERN STREAM AND CUTS OFF OVER THE SE US FOR THE MID TO LATE WEEK PERIOD...WHILE THE REST SWINGS THROUGH THE NORTHEAST DURING THE MIDWEEK PERIOD. SOME UNCERTAINTY IN THE FORECAST LIES IN THE INTERACTION OF THE DIGGING EASTERN TROUGH WITH PIECES OF SUB-TROPICAL ENERGY ROUNDING DOMINANT ATLANTIC RIDGING...AND HOW CLOSE TO THE COAST THIS MOISTURE/ENERGY MAY GET FOR MUCH OF THE WEEK. IN TERMS OF SENSIBLE WEATHER...A MOISTURE STARVED COLD FRONT WITH SHORTWAVE ENERGY WELL TO THE NW PASSES EAST OF THE REGION SUNDAY MORNING. A FEW LINGERING SHOWERS POSSIBLE SUNDAY MORNING...OTHERWISE A COOLER AND DRIER AIRMASS BEGINS ADVECTING INTO THE REGION ON BREEZY NORTHERLY FLOW ON SUNDAY. TEMPS SUNDAY SHOULD BE NEAR SEASONABLE. AS HIGH PRESSURE CONTINUES TO BUILD THROUGH AND EAST OF NEW ENGLAND EARLY TO MID NEXT WEEK...A BREEZY NE FLOW WILL PERSIST AND MAINTAIN A MAINLY DRY BUT SEASONABLY COOL CANADIAN MARITIMES AIRMASS OVER THE REGION. THE TIGHT GRADIENT WILL BE COURTESY OF A SERIES OF LOWS DRIFTING NE WELL OFF THE EAST COAST. AS MENTIONED BEFORE...UNCERTAINTY EXISTS ON EXACT EVOLUTION OF THESE OFFSHORE LOW/S INTO MIDWEEK...BUT NHC SEES A MEDIUM POTENTIAL FOR SOME SORT OF TROPICAL/SUB-TROPICAL DEVELOPMENT OVER THE NEXT 5 DAYS. THERE IS CURRENTLY A SLIGHT POTENTIAL FOR THE REGION TO AFFECTED BY SOME SHOWER ACTIVITY MIDWEEK AS THE EARLIER MENTIONED NORTHERN STREAM SHORTWAVE APPROACHES/SWINGS THROUGH...BUT THIS WILL ULTIMATELY BE DEPENDENT ON EVOLUTION OF THE OFFSHORE LOW PRESSURE/S AND STRENGTH OF UPPER CONFLUENCE/SURFACE RIDGING OVER THE NE. OTHERWISE...THE SAME MIDWEEK PATTERN COULD PERSIST THROUGH THE WEEK IN THE CONTINUED SPLIT FLOW REGIME...WITH THE REGION IN BETWEEN NORTHERN STREAM FLOW WELL TO THE NORTH...A BROAD CUTOFF LOW TO THE SOUTH...AND DOMINANT OFFSHORE RIDGING TO THE SE. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE REMAINS OFFSHORE TODAY AS A COLD FRONT APPROACHES FROM THE WEST. THIS REMAINS A CHALLENGING FORECAST WITH THE EXTENT OF FOG/STRATUS OVERNIGHT. AIRMASS REMAINS EXTREMELY DRY JUST OFF THE DECK WITH A LIGHT S/SW FLOW AT THE SFC. IN ADDITION...THERE ARE SOME HIGH LEVEL CLOUDS MOVING IN FROM THE WEST THAT COULD LIMIT THE COVERAGE. FOR NOW...WILL GO IFR AT KGON BASED ON CURRENT CONDITIONS...AND PATCHY MVFR ELSEWHERE OUTSIDE THE NYC TERMINALS. GUIDANCE VARIES WITH THE BEST CHANCE OF STRATUS/FOG ACROSS CT. .OUTLOOK FOR 06Z SATURDAY THROUGH WEDNESDAY... .SAT NIGHT...VFR. CHC OF WIDELY SCT SHOWERS WITH COLD FROPA. .SUN-TUE...MAINLY VFR. CHC SUB-VFR TUE. N-NE GUSTS 20-25KT POSSIBLE AT COASTAL TERMINALS. .WED...VFR. && .MARINE... CONDITIONS ACROSS THE AREA WATERS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS THROUGH SATURDAY...AS HIGH PRESSURE MOVES OFFSHORE. SCA WIND GUSTS POSSIBLE SUNDAY AFTERNOON FOR ALL WATERS IN WAKE OF COLD FRONTAL PASSAGE...BUT BETTER POTENTIAL FOR SCA DEVELOPS SUNDAY NIGHT AND LIKELY THROUGH EARLY NEXT WEEK ESPECIALLY ON THE OCEAN WITH DEVELOPMENT OF A PERSISTENT E/NE FLOW. OCEAN SEAS COULD BUILD TO 6 TO 8 FT FOR EARLY NEXT WEEK...USUALLY UNDER-PREDICTED IN WNA GUIDANCE. WINDS MAY ALSO GUST CLOSE TO 25 KT DURING THIS TIME ACROSS ALL WATERS. && .FIRE WEATHER... FUEL MOISTURE LEVELS WILL LIKELY CONTINUE TO DECREASE THROUGH THE WEEKEND WITH THE UNSEASONABLY WARM AND DRY WEATHER. CURRENTLY KBDI VALUES ARE GREATER THAN 300 OVER A GOOD PORTION OF THE REGION. DEPENDING ON COVERAGE OF LIGHT RAINFALL WITH COLD FRONTAL PASSAGE SAT NIGHT/EARLY SUN...PREDECESSOR DRY CONDS WITH A GUSTY N FLOW AND LOW RH VALUES MAY RESULT IN AN ENHANCED FIRE WEATHER THREAT ON SUNDAY. && .HYDROLOGY... DRY CONDITIONS EXPECTED THROUGH SATURDAY WITH NO WIDESPREAD SIGNIFICANT PRECIPITATION EXPECTED THROUGH NEXT WEEK. && .TIDES/COASTAL FLOODING... THERE IS THE POSSIBILITY FOR MINOR COASTAL FLOODING DURING THE MON-FRI TIMEFRAME DUE TO THE FORECAST OF PROLONGED E-NE FLOW. POTENTIAL FOR IMPACTS APPEARS LOW FOR MON...BUT MAY INCREASE IN THE TYPICALLY VULNERABLE LOCALES FOR THE MID TO LATE WEEK PERIOD WITH GRADUALLY RISING ASTRONOMICAL HIGH TIDES. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...GOODMAN/NV NEAR TERM...GOODMAN/JM SHORT TERM...GOODMAN LONG TERM...DW AVIATION...24 MARINE...GOODMAN/NV FIRE WEATHER... HYDROLOGY...GOODMAN/NV TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1253 AM CDT SAT SEP 19 2015 .SHORT TERM... 211 PM CDT THROUGH TONIGHT... IN ADDITION TO SOME LIGHT RAIN/DRIZZLE FARTHER NORTH...WE ARE BEGINNING TO SEE SCATTERED SHOWER DEVELOPMENT FARTHER NORTH INTO OUR AREA THIS AFTERNOON AS THE AREA BEGINS TO FEEL MORE OF THE LIFT FROM A PAIR OF LEADING SHORTWAVES AHEAD OF A VERY WELL DEFINED UPPER LEVEL TROUGH AND CLOSED CIRCULATION MOVING EAST THROUGH THE DAKOTAS. THE FIRST OF THESE WAVES IS PUSHING INTO WEST CENTRAL ILLINOIS WHERE MORE ORGANIZED THUNDERSTORM ACTIVITY IS FOCUSED. THESE ARE IN AREAS WHERE EARLIER BREAKS IN LOWER LEVEL STRATUS HAVE ENABLED GREATER DESTABILIZATION. A STATIONARY FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE WESTERN CWA. ADDITIONAL ELEVATED THUNDERSTORMS THROUGH SOUTHERN IOWA AND EXTENDING TO NEAR THE MISSISSIPPI RIVER IN FAR EASTERN IOWA AHEAD OF THESE ADDITIONAL LEADING SHORTWAVES. EXPECT SHOWERS AND ISOLATED THUNDERSTORMS TO INCREASE IN COVERAGE INTO NORTHEAST ILLINOIS AND NORTHWEST INDIANA. AS THE AFTERNOON CONTINUES. WITH THE THICK CLOUD COVER FARTHER NORTH...FEEL THE MORE ACTIVE STORMS WILL BE CONFINED ALONG AND SOUTH OF INTERSTATE 80 WHERE LOCALLY HEAVY RAINFALL IS EXPECTED AND STORM MOTION IS NOT SUPER FAST. A SEVERE THREAT EXISTS AS WELL DUE TO MODEST MID LEVEL LAPSE RATES (NEAR 7 DEG/KM ON THE KDVN MORNING SOUNDING)...THOUGH SHEAR HAS DECREASED SOMEWHAT LOWER THAN WHAT WAS DEPICTED EARLIER TODAY ON THE RAP SPC MESOANALYSIS. IT IS FORECAST TO INCREASE AGAIN AS THE AFTERNOON CONTINUES...KEEPING SOME THREAT FOR GUSTY WINDS AND HAIL MAINLY FOR OUR WESTERN AND SOUTHERN AREAS. WIDESPREAD SEVERE WEATHER WITH THIS WAVE IS NOT ANTICIPATED AS SHOWERS/STORMS TO THE NORTH WILL BE ELEVATED. IT LOOKS LIKE AFTER THIS ACTIVITY MOVES THROUGH...THERE COULD BE A SHORT BREAK BEFORE THE MORE ORGANIZED ACTIVITY ASSOCIATED WITH THE UPPER TROUGH MOVES THROUGH LATER THIS EVENING AND TONIGHT. THIS BREAK...IF IT OCCURS...WOULD LAST THE LONGEST FOR POINTS SOUTH AND EAST ABD THERE MAY NOT BE MUCH OF A BREAK IN AREAS NORTH AND WEST. THE TIMING ON THIS ROUND OF MORE ORGANIZED THUNDERSTORM ACTIVITY IS AFTER 7-8 PM IN THE WEST...AND AFTER 9 PM CLOSER TO CHICAGO. CURRENT SHORT TERM RUNS OF THE HRRR/RAP SUGGEST IT COULD BE SLIGHTLY LATER THAN THAT FOR AREAS SOUTH AND EAST OF I-57. THE BEST COMBINATION OF UPPER Q-G FORCING FROM THE UPPER TROUGH AND LOWER FRONTOGENETICAL FORCING ON THE BACK SIDE OF THE SURFACE LOW IS ALONG AND NORTH OF I- 80 FOR THIS SECOND ROUND OF STORMS...WHICH IS MAXIMIZED IN THE LATE EVENING AND EARLY MORNING HOURS WHEN THE PERIOD OF HIGHEST CONCERN FOR HEAVY RAIN EXISTS. MANY AREAS WILL SEE HEAVY RAIN ACTIVITY WITH THIS WAVE...BUT HAVE HELD ONTO THE FLASH FLOOD WATCH FOR THE CURRENT AREAS THAT RECEIVED THE HEAVIEST RAINS LAST NIGHT. LEAST FAVORED AREAS ARE SOUTH AND EAST OF INTERSTATE 57 AND HAVE PLACED HIGHEST QPF IN THE MOST FAVORED FORCING LOCATIONS IN NORTH AND NORTH CENTRAL ILLINOIS. MOST UNSTABLE CAPE IN EXCESS OF 1000 J/KG AND EFFECTIVE SHEAR OF 40+ KT SUGGEST THE POTENTIAL FOR SEVERE HAIL AND LOCALLY STRONG WINDS AGAIN WITH THE LATER EVENING STORMS...WITH THE WIND THREAT CONTINGENT ON STORMS EVOLVING INTO A LINE. THE SURFACE LOW CONTINUES DEEPENING OVERNIGHT AS IT MOVES NORTHEASTWARD. THE COLD FRONT SPREADS IN FROM NORTHWEST TO SOUTHEAST WHICH SHOULD EASE SHOWER/STORM THREAT OVERNIGHT. BRISK NORTHWEST WINDS WILL USHER IN A MUCH COOLER AND DRIER AIRMASS. KMD && .LONG TERM... 236 PM CDT SATURDAY THROUGH FRIDAY... MID-LEVEL SHORT WAVE TROUGH AND SURFACE FRONTAL SYSTEM ASSOCIATED WITH SHORT TERM RAIN/THUNDERSTORMS WILL BE MOVING OUT OF THE FORECAST AREA EARLY SATURDAY MORNING. LINGERING LOW LEVEL MOISTURE BEHIND THE FRONT AND FORCING ASSOCIATED WITH THE PASSAGE OF THE MID-LEVEL TROUGH MAY ALLOW A FEW SHOWERS/SPRINKLES TO PERSIST MAINLY ACROSS THE FAR SOUTHEAST PARTS OF THE CWA PAST SUNRISE...THOUGH BREEZY NORTH WINDS QUICKLY ADVECT DRIER AIR INTO THE REGION PER FORECAST SOUNDINGS ALLOWING A QUICK END TO ANY PRECIP AND DECREASING CLOUD COVER THROUGH THE LATE MORNING HOURS. WHILE SUNSHINE RETURNS...COOLER TEMPS IN THE UPPER 60S/AROUND 70 AND BREEZY NORTH WINDS GUSTING AROUND 20 MPH ESPECIALLY IN THE MORNING WILL MAKE FOR AN AUTUMN FEEL. SURFACE HIGH PRESSURE BUILDS ACROSS THE AREA SATURDAY NIGHT...WITH CLEAR SKIES...LIGHT/CALM WINDS AND COOL/DRY AIR MASS...WILL LIKELY PRODUCE SOME CHILLY LOW- MID 40S IN COOLER SPOTS AND HAVE UNDERCUT GUIDANCE/BLENDED TOWARD COOLER MAV MINS. BREEZY NORTH WINDS GUSTING 20-25 MPH SATURDAY MORNING/EARLY AFTERNOON WILL QUICKLY DIMINISH DURING THE AFTERNOON. REST OF EXTENDED PERIOD LOOKS TO REMAIN VERY QUIET...WITH A GRADUAL MODERATING TREND THROUGH MID/LATE WEEK AS UPPER RIDGE DEVELOPS OVER THE SOUTHWESTERN CONUS...AND EVENTUALLY BUILDS NORTHEASTWARD INTO THE GREAT LAKES REGION BY MID-WEEK. SURFACE HIGH SLIDES EAST OF THE AREA BY LATER SUNDAY...THOUGH WESTERN PERIPHERY OF SFC RIDGE AXIS LINGERS ACROSS THE REGION FOR A FEW DAYS. THIS SETS UP A FAIRLY PLEASANT PERIOD OF MILD DAYS WITH TEMPS SLOWLY WARMING FROM THE LOW 70S (UPPER 60S NEAR THE LAKE) TO 75-80/LOW 80S RANGE BY THE LATTER HALF OF THE WEEK...WITH LOWS IN THE 40S/50S MODERATING BACK INTO THE 50S/NEAR 60. NO REAL THREAT OF ORGANIZED RAIN APPEARS AT THIS TIME BEYOND SATURDAY MORNING...UNTIL PERHAPS LATE THURSDAY OR FRIDAY AS A WEAK COLD FRONT SETTLES ACROSS THE UPPER MISSISSIPPI/WESTERN LAKES REGION. SOME MODEL SOLUTIONS KEEP THIS FRONT NORTH OF THE AREA HOWEVER...OR DONT DEVELOP SIGNIFICANT PRECIP ALONG IT...WITH THE UPPER RIDGE RE-BUILDING INTO NEXT WEEKEND. THUS HAVE HELD FORECAST DRY THROUGH FRI AND GIVEN JUST A NOD TO SLIGHTLY COOLER TEMPS ACROSS THE NORTHERN PART OF THE FORECAST AREA BY FRIDAY PER BLENDED GUIDANCE. RATZER && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * WIND SHIFT TO NORTH/NORTHWEST EARLY THIS MORNING. * STRONG/GUSTY NORTH/NORTHWEST WINDS THRU MID AFTERNOON. * POSSIBLE NORTHEAST WIND SHIFT/LAKE BREEZE LATE THIS AFTERNOON. * MVFR CIGS THRU MID MORNING...POSSIBLE IFR CIGS EARLY THIS MORNING. CMS //DISCUSSION...UPDATED 06Z... LAST LINE OF THUNDERSTORMS NOW PUSHING EAST OF ORD/MDW AND WILL AFFECT GYY THRU 07Z. COLD FRONT WILL MOVE ACROSS THE TERMINALS OVER THE NEXT FEW HOURS WITH STRONG NORTHWEST WINDS BEHIND THE FRONT ALREADY AT RFD. THESE STRONGER WINDS WILL SPREAD ACROSS THE TERMINALS THIS MORNING WITH WIND DIRECTIONS INTO THE 340-360 RANGE. STILL A CHANCE OF SHOWERS THRU THE OVERNIGHT HOURS AND ESPECIALLY WITH THE FRONTAL PASSAGE. MVFR CIGS APPEAR LIKELY ACROSS THE REGION THRU MID MORNING...BUT A PERIOD OF IFR CIGS IS ALSO POSSIBLE. WINDS WILL SLOWLY DIMINISH THIS AFTERNOON AS THE GRADIENT BEGINS TO WEAKEN. ITS POSSIBLE A LAKE BREEZE MAY DEVELOP AND PUSH INLAND LATE THIS AFTERNOON. IF THIS OCCURS...WINDS MAY TURN NORTHEASTERLY AT ORD/MDW. SPEEDS WITH THIS FRONTAL PASSAGE COULD APPROACH 10KTS...BUT CONFIDENCE IS LOW. CMS //ORD AND MDW CONFIDENCE...UPDATED 06Z... * HIGH FOR WINDS THRU THIS AFTERNOON...LOW FOR LAKE BREEZE AND TIMING LATE THIS AFTERNOON. * MEDIUM FOR IFR CIGS EARLY THIS MORNING. CMS //OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z... SUNDAY THROUGH THURSDAY...VFR. IZZI && .MARINE... 257 PM CDT MAIN MARINE CONCERNS ARE IN THE FIRST 24-36 HOURS OF THE FORECAST THIS AFTERNOON...WITH A PERIOD OF NORTH GALES LIKELY ON CENTRAL AND SOUTHERN LAKE MICHIGAN SATURDAY MORNING. A NEARLY STATIONARY COLD FRONT STRETCHED FROM LOW PRESSURE OVER EASTERN CANADA...SOUTHWEST ACROSS LAKE MICHIGAN TO THE SOUTHERN PLAINS. A SURFACE LOW PRESSURE WAVE WILL LIFT NORTHEAST ALONG THE FRONT THIS EVENING...EVENTUALLY DEEPENING AS IT LIFTS NORTHEAST OF THE LAKE EARLY SATURDAY AND PULLING THE COLD FRONT SOUTHEAST AND CLEAR OF THE LAKE. AS THE LOW DEEPENS OFF TO THE NORTHEAST EARLY SATURDAY...AND HIGH PRESSURE BEGINS TO BUILD EASTWARD ACROSS THE PLAINS...THE COMBINATION OF A TIGHTENING SURFACE PRESSURE GRADIENT AND LOW LEVEL COLD AIR ADVECTION IS EXPECTED TO LEAD TO A BRIEF PERIOD OF 30-35 KT WINDS OVER THE LAKE. GALE FORCE WINDS APPEAR TO BE MOST LIKELY ACROSS CENTRAL AND SOUTHERN LAKE MICHIGAN FROM THE PREDAWN HOURS THROUGH MID-LATE MORNING SATURDAY. WINDS WILL THEN QUICKLY DIMINISH LATER SATURDAY AFTERNOON AND NIGHT AS THE SURFACE HIGH MOVES INTO THE REGION. BEYOND SATURDAY...THE WEATHER PATTERN LOOKS TO REMAIN FAIRLY QUIET WITH THE TRAILING WESTERN PERIPHERY OF THE SURFACE RIDGE AXIS REMAINING OVER THE CENTRAL OR SOUTHERN PART OF THE LAKE...WHILE AN AREA OF LOW PRESSURE PASSES WELL NORTH OF THE LAKES THROUGH MID- WEEK. THIS WILL LIKELY RESULT IN MODEST SOUTH- SOUTHWEST WINDS INCREASING A BIT ON THE NORTH END OF THE LAKE AND PERHAPS GUSTING 15-20 KTS AT TIMES...WHILE REMAINING LIGHTER FARTHER SOUTH. RATZER && .LOT WATCHES/WARNINGS/ADVISORIES... IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010- ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022 UNTIL 7 AM SATURDAY. BEACH HAZARDS STATEMENT...ILZ006-ILZ014...4 AM SATURDAY TO 10 PM SATURDAY. IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...4 AM SATURDAY TO 10 PM SATURDAY. LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777- LMZ779...4 AM SATURDAY TO 1 PM SATURDAY. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
353 AM CDT SAT SEP 19 2015 ...UPDATED LONG TERM SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 111 AM CDT SAT SEP 19 2015 The main challenge in the short term will be low stratus potential up in the northeast zones (particularly around Hays) and if it will impact temperatures at all. A secondary push of cooler air was making its way south into southwest Kansas with a slight bump in winds from the north. On the 11-3.9u imagery during the overnight hours, we were watching an area of stratus advance south- southwestward toward north central KS. The HRRR suggests that this will reach as far southwest as a Dighton to Dodge City line by 14z. This may be a bit ambitious, but there is certainly some merit to this prog as there is some better low level moisture across central/south central Nebraska that wrapped around the low...which will likely continue to advect southwestward through the early morning hours. We will bump up the clouds in the Sky grids to reflect this latest thinking, especially northeast of the Dighton to Dodge City line. Any low stratus should erode by late morning given how shallow it will be. Temperatures today, with the fresh Canadian airmass in place, will only top out in the lower to mid 70s. Will go with slightly cooler temps in the north where low morning clouds will likely delay the diurnal warmup. Advancing to tonight, we will see low level winds turn back around to the south in response to another loosely organized Pacific system moving into the Northern Rockies. Some marginal moisture will return via the "scenic route" (Eastern New Mexico/western TX-OK Panhandles), and increased deformation/convergence in the 700-800mb layer will promote some elevated showers and isolated thunderstorms after 06z Sunday. We will maintain the 20-30 POPs across mainly the western third of the forecast area late tonight, with low Chance POPs between the Arkansas River and the OK border in the 12-18z Sunday time frame. .LONG TERM...(Sunday THROUGH Friday) ISSUED AT 352 AM CDT SAT SEP 19 2015 Our region of the world will once again see a warming trend going into next week as the primary polar jet shifts back to the north and mid level heights rise across the Southern and Central Rockies/adjacent High Plains. During the slow transition back into above-average temperatures, we will see low chances for precipitation, particularly early Sunday as one last shortwave trough ripples through the longwave trough. Highs Sunday will be tricky, and we feel that portions of south central Kansas, especially, will stay stuck in the 60s to lower 70s with elevated convection and stratus clouds lingering through at least the middle part of the day. The lee trough comes back strong by Monday and will be a quasi- steady feature through at least Wednesday. Afternoon temperatures will gradually increase each day with highs in the lower 90s in some locations. The global spectral models suggest a subtropical shortwave trough ejecting from the Baja California region into Rockies which will bring some mid level moisture across into the High Plains. We will have some Slight Chance to Chance POPs in the grids Wednesday Night through Thursday Night, but at this point, it does not look like a real good opportunity for widespread beneficial rainfall across our region given the degree of downslope momentum in the middle troposphere and the general weak nature of the subtropical system to begin with. Beyond mid-week, it certainly looks like we will continue the theme of above average temperatures across the Rockies and adjacent High Plains in the final days of September with both the GFS and the ECMWF showing some semblance of a longwave trough across western North America leading to fairly strong (warm and dry) southwest momentum across the Rockies. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Saturday NIGHT) ISSUED AT 1134 PM CDT FRI SEP 18 2015 Aviation weather will be fairly tranquil as high pressure continues to settle in across western Kansas. There is a secondary surge of stronger north wind moving in, so expect wind speeds to pick back up at GCK and DDC to the 12 to 16 knot range for a few hours in the 06 to 10z time frame, but they will drop back to below 10 knots by daybreak. Winds will remain light through the day Saturday, but winds will gradually pick back up (from the southeast) late in the day in response to a redeveloping leeside trough. VFR conditions are expected to prevail with the dry airmass in place now. && .PRELIMINARY POINT TEMPS/POPS... DDC 73 55 75 59 / 0 20 30 10 GCK 74 53 80 58 / 10 30 30 10 EHA 74 50 84 57 / 10 20 20 10 LBL 75 54 84 59 / 10 30 20 10 HYS 70 52 78 60 / 0 10 20 10 P28 74 58 75 61 / 0 20 20 10 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Umscheid
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
112 AM CDT SAT SEP 19 2015 ...Updated Short Term Section... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 111 AM CDT SAT SEP 19 2015 The main challenge in the short term will be low stratus potential up in the northeast zones (particularly around Hays) and if it will impact temperatures at all. A secondary push of cooler air was making its way south into southwest Kansas with a slight bump in winds from the north. On the 11-3.9u imagery during the overnight hours, we were watching an area of stratus advance south- southwestward toward north central KS. The HRRR suggests that this will reach as far southwest as a Dighton to Dodge City line by 14z. This may be a bit ambitious, but there is certainly some merit to this prog as there is some better low level moisture across central/south central Nebraska that wrapped around the low...which will likely continue to advect southwestward through the early morning hours. We will bump up the clouds in the Sky grids to reflect this latest thinking, especially northeast of the Dighton to Dodge City line. Any low stratus should erode by late morning given how shallow it will be. Temperatures today, with the fresh Canadian airmass in place, will only top out in the lower to mid 70s. Will go with slightly cooler temps in the north where low morning clouds will likely delay the diurnal warmup. Advancing to tonight, we will see low level winds turn back around to the south in response to another loosely organized Pacific system moving into the Northern Rockies. Some marginal moisture will return via the "scenic route" (Eastern New Mexico/western TX-OK Panhandles), and increased deformation/convergence in the 700-800mb layer will promote some elevated showers and isolated thunderstorms after 06z Sunday. We will maintain the 20-30 POPs across mainly the western third of the forecast area late tonight, with low Chance POPs between the Arkansas River and the OK border in the 12-18z Sunday time frame. .LONG TERM...(Saturday NIGHT THROUGH Friday) ISSUED AT 220 PM CDT FRI SEP 18 2015 High temperatures have most recently been best handled by the bias corrected ECMWF MOS. Further past the weekend temperatures will rapidly bounce back toward around 90 degrees on Monday and Tuesday as the southerly flow becomes reestablished. Recent forecasts have included chances for thunderstorms centered around the late Sunday timeframe. This potential still looks favorable with rapid return flow along a redeveloped surface trough over the central High Plains and differential vorticity advection across the area. The next appreciable chance returns on Wednesday or Thursday as the upper flow turn more southwesterly with stronger embedded shortwaves helping to create lee cyclones over the northern plains region. Breezy and warm should also be the character of the period with strong southwest downslope flow for several days. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Saturday NIGHT) ISSUED AT 1134 PM CDT FRI SEP 18 2015 Aviation weather will be fairly tranquil as high pressure continues to settle in across western Kansas. There is a secondary surge of stronger north wind moving in, so expect wind speeds to pick back up at GCK and DDC to the 12 to 16 knot range for a few hours in the 06 to 10z time frame, but they will drop back to below 10 knots by daybreak. Winds will remain light through the day Saturday, but winds will gradually pick back up (from the southeast) late in the day in response to a redeveloping leeside trough. VFR conditions are expected to prevail with the dry airmass in place now. && .PRELIMINARY POINT TEMPS/POPS... DDC 73 55 80 59 / 0 20 30 10 GCK 74 53 81 58 / 10 30 30 10 EHA 74 50 83 57 / 10 20 20 10 LBL 75 54 81 59 / 10 30 20 10 HYS 70 52 84 60 / 0 10 20 10 P28 74 58 79 61 / 0 20 20 10 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Russell AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS NORMAN OK
313 AM CDT SAT SEP 19 2015 .DISCUSSION... SCATTERED SHOWERS AND THUNDERSTORMS WILL SLOWLY CONTINUE TO SLIDE SOUTH WITH THE 850 MB FRONTOGENETIC ZONE THROUGH THE MORNING HOURS. THE HRRR HAS THE BEST HANDLE ON WHAT IS OCCURRING RIGHT NOW SO POPS WERE ADJUSTED UPWARD ALONG THIS NARROW ZONE THROUGH SUNRISE. MOST OF THE RAIN WILL MOVE TOWARD THE RED RIVER BEFORE LUNCHTIME AND SKIES WILL CONTINUE TO CLEAR FROM NE TO SW. EXPECT LINGERING STRATUS ACROSS THE SW...HOWEVER...THROUGH MOST OF THE DAY. MUCH COOLER TEMPS ARE EXPECTED TODAY BEHIND THE COLD FRONT FROM THE MID 70S NORTHWARD TO THE LOW 80S SOUTHWARD. THE NEXT CHANCE FOR RAIN RETURNS SUN AS ISENTROPIC ASCENT DEVELOPS AND A WEAK MID LEVEL SHORTWAVE TROUGH MOVES OUT OF THE ROCKIES. THE HIGHEST CHANCES WILL LIKELY BE DURING THE MORNING HOURS ACROSS WESTERN AND CENTRAL OK...AND THEN SHIFT NE/E DURING THE DAY. DECIDED TO LOWER TEMPS ACROSS THE NORTH AND EAST FOR THIS REASON SIMILAR TO THE NAM12. RAIN CHANCES WILL LINGER ACROSS THE EAST THROUGH EARLY MON AM AS A MORE SIGNIFICANT MID TO UPPER LEVEL SHORTWAVE TROUGH MOVES INTO NE/E OK. MONDAY SHOULD BE MOSTLY CLEAR AS THE WAVE QUICKLY MOVES INTO THE MISS RIVER VALLEY. TEMPS WILL BEGIN TO REBOUND BACK TO/OR JUST ABOVE AVG MONDAY...AND THEN WARM UP THROUGH MID WEEK AS THE SUBTROPICAL RIDGE MOVES OVER THE SOUTHERN PLAINS. MOST OF THE NWP MODELS INDICATE A MID TO UPPER SHORTWAVE TROUGH WILL MOVE SOMEWHERE NEAR KS THROUGH THURS SO WILL GO WITH SOME SLIGHT CHCS ACROSS NORTHERN OK DURING THIS TIME PERIOD. OTHERWISE...EXPECT ABOVE AVG TEMPS THROUGH THE EXTENDED PERIOD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 76 61 81 64 / 20 40 40 30 HOBART OK 77 62 85 65 / 20 50 50 20 WICHITA FALLS TX 82 66 88 67 / 40 40 40 20 GAGE OK 76 58 84 62 / 10 30 40 10 PONCA CITY OK 77 57 76 62 / 10 20 30 30 DURANT OK 84 67 86 66 / 30 40 50 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 26/03
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
523 AM EDT SAT SEP 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. HIGH PRESSURE WILL BRING A RETURN OF NEAR NORMAL DAYTIME TEMPERATURES FOR SUNDAY AND CONTINUE INTO THE MIDDLE OF NEXT WEEK. AN UPPER LEVEL LOW MAY LEAD TO A FEW SHOWERS MONDAY OR TUESDAY OVER THE SOUTHERN MOUNTAINS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3AM...THE SURFACE LOW WAS NEAR CHICAGO WITH THE COLD FRONT TRAILING SOUTH THROUGH ILLINOIS. THERE IS GOOD AGREEMENT ON THE TIMING OF THE FRONT...ENTERING WESTERN PA BY ABOUT 18Z...AND MOVING INTO THE SUSQ VALLEY BY 00Z. THERE IS ALSO GOOD AGREEMENT WITH THE PARENT UPPER SHORTWAVE SHEARING OUT THROUGH THE EASTERN LAKES AND SOUTHERN CANADA...LEADING TO A WEAKENING OF THE LARGE SCALE FORCING FOR THE SHOWERS AND THUNDERSTORMS CURRENTLY TRACKING EAST OVER CENTRAL LAKE ERIE DOWN INTO FAR NORTHERN OHIO. EXTRAPOLATION AND HRRR TIMING SUGGEST THESE BEGIN TO ENCROACH ON MY FAR NWRN ZONES BETWEEN ABOUT 7 AND 9 AM...11-13Z. THESE LEADING SHOWERS AND STORMS ARE MADE TO WEAKEN BY THE NEAR TERM MESO MODELS AS THEY MOVE OUT OF THE MOUNTAINS. ADDITIONAL CONVECTION ALONG THE COLD FRONT WILL ORGANIZE TO THE WEST AND ENTER THE NWRN MOUNTAINS ONCE AGAIN BY EARLY TO MID AFTERNOON...WITH A BETTER CHANCE OF SURVIVING INTO THE CENTRAL MOUNTAINS BY LATER TODAY AND THIS EVENING. THE WEAKENING TREND IN THE MODELS IS CONSISTENT AS THE FRONT PUSHES EAST...AND IT REMAINS UNCLEAR HOW MUCH EAST OF A LINE FROM ABOUT WILLIAMSPORT TO STATE COLLEGE TO ABOUT BEDFORD THE RAIN WILL MANAGE TO GET BEFORE PETERING OUT. THE HIGHEST CHANCES FOR RAIN WILL BE OVER NORTHERN AND NORTHWESTERN AREAS WHERE I HAVE CATEGORICAL POPS FOR TODAY. THE NUMBERS TAPER DOWN QUICKLY INTO THE CENTRAL MOUNTAINS AND LOWER STILL OVER MY SERN ZONES. QPF WILL RANGE FROM MEAGER AMOUNTS FROM THE MIDDLE SUSQUEHANNA VALLEY WEST TO THE LAURELS...TO PERHAPS .50" TO .75" OVER THE FAR NW. MODEST INSTABILITY AND MARGINAL WIND PROFILES SHOULD LIMIT SEVERE POTENTIAL TODAY...BUT SPC HAS PAINTED NWRN PA WITH A MARGINAL RISK FOR SEVERE STORMS TODAY. THE BEST CHANCE SEEMS TO BE IF A STRONG LINE CAN FORM IN OHIO/LOWER LAKES AND TRACK INTO THE REGION BEFORE IT DECAYS THIS EVENING. WE`LL EEK OUT ONE MORE WARM DAY AHEAD OF THE COLD FRONT WITH HIGHS IN THE MID 70S TO MID 80S. A COOL DOWN WILL BEGIN TONIGHT AS HIGH PRESSURE PUSHES QUICKLY INTO THE EASTERN GR LAKES AND SHOVES THE COLD FRONT OFF TO THE SOUTH. LOWS WILL RANGE FROM THE CHILLY MID 40S OVER THE NORTH TO AROUND 60 IN THE SOUTHEAST. OVER AREAS WHERE SKIES CLEAR TONIGHT...FOG SEEMS LIKELY LATE. THE BEST CHANCE WOULD SEEM TO BE OVER THE NORTHERN MOUNTAINS. && .SHORT TERM /SUNDAY/... CLOUDS WILL SETTLE OFF TO THE SOUTH SUNDAY AS HIGH PRESSURE QUICKLY MOVES INTO NORTHERN PA/SOUTHERN NY. IT WILL BE A MARKEDLY COOLER DAY WITH HIGHS AVERAGING AROUND 10 DEG COOLER THAN TODAY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... CONFIDENCE IN THE EXTENDED FORECAST CONTINUES TO DWINDLE WITH EACH PASSING MODE RUN. EARLY IN THE PERIOD...MODELS AGREE IN BRINGING FAIRLY AMPLIFIED UPPER TROUGH THROUGH THE OHIO VALLEY INTO THE NERN US. THE RESULTING SOUTH-SOUTHEAST FLOW SHOULD BRING THE CHANCE OF SOME LIGHT RAINS FOR MONDAY AND POSSIBLY TUESDAY. AT THIS POINT I HAVE FAIRLY LOW CHANCES OF RAIN OVER MUCH OF THE AREA MONDAY AND MAINLY OVER SOUTHERN AREAS INTO TUESDAY. BEFORE THIS HAPPENS HOWEVER...WITH CLEAR SKIES...VERY DRY AIR AND LIGHT WINDS...LOWS OVER THE NWRN MOUNTAINS MONDAY MORNING WILL DROP DOWN INTO THE MIDDLE 30S. MAY SEE THE FIRST FROST OF THE SEASON IN A FEW OF THE NORMAL COLD SHELTERED LOCATIONS. FROM THERE MODEL SOLUTIONS DIVERGE FURTHER. THE ECMWF AND GFS/GEFS ALL SHOW THE UPPER TROUGH CLOSING OFF. WHAT HAPPENS THEN MEANS THE DIFFERENCE BETWEEN A MILD AND DRY REST OF THE WEEK...OR A COLD RAINY ONE. THE GFS/GEFS HAVE TRENDED MUCH FURTHER NORTH WITH THE UPPER LOW...KEEPING AN EXTENDED PERIOD OF MOIST EASTERLY LOW LEVEL FLOW FROM WEDNESDAY INTO FRIDAY. THIS WOULD RESULT IN A PERIOD OF CHILLY WET WEATHER. THE ECMWF ON THE OTHER HAND SETTLES THE LOW DOWN OVER THE SERN STATES AND EVEN TRACKS IT WEST ALONG THE GULF COAST FOR THE WEEKEND. THIS WOULD KEEP US UNDER FAVORABLE RIDGING NORTH OF THE SYSTEM...WITH DRY AND MILD CONDITIONS. I USED OUR SUPERBLENDED MODEL MOS WHICH DOWNPLAYS THE GFS/GEFS PESSIMISM...RESULTING IN A MUCH BRIGHTER FORECAST FROM MID WEEK ONWARD. PRESUMING THE OPTIMISTIC FORECAST VERIFIES...TEMPERATURES WHICH WILL START THE WEEK BELOW NORMAL WILL TREND BACK TO A BIT ABOVE NORMAL BY MID WEEK. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... 09Z TAFS SENT. SOME SHOWERS MOVING TOWARD BFD. ADJUSTED THIS TAF. THE ACTIVITY SHOULD WEAKEN...AS THE SHOWERS MOVE AWAY FROM THE BETTER DYNAMICS AND MOISTURE. EARLIER DISCUSSION BELOW. RIDGE OF HIGH PRESSURE ALONG THE EAST COAST WILL ENSURE ANOTHER NIGHT OF FAIR WEATHER AND LIGHT WIND ACROSS CENTRAL PA. MAIN AVIATION CONCERN WILL BE EARLY AM FOG...FOCUSED MAINLY ACROSS SOUTHEAST PA...DIRECTLY BENEATH RETREATING SFC RIDGE. A DEVELOPING SOUTHERLY BREEZE AND PATCHY MID LVL CLOUDS WORKING INTO THE WESTERN HALF OF THE STATE SHOULD LIMIT THE FOG POTENTIAL FROM THE CENTRAL MTNS WESTWARD. LATEST HRRR/NAM/LAMP...AS WELL AS LATEST SREF...ALL SUPPORT A LIKELY PERIOD OF IFR/LIFR CONDS AT KLNS BTWN 09Z-14Z. CAN/T RULE OUT OF BRIEF PERIOD OF IFR CONDS AT KIPT/KMDT ARND DAWN. HOWEVER...CONFIDENCE NOT AS HIGH. ANY FOG ACROSS SOUTHEAST PA SHOULD LIFT BY LATE AM. FOCUS WILL THEN SHIFT TOWARD A COLD FRONT PUSHING INTO NORTHWEST PA LATE IN THE DAY. A WEAKENING BAND OF SHRA/TSRA WILL LIKELY PRODUCE A BRIEF VIS REDUCTION AT KBFD LATE IN THE DAY...AND POSSIBLY AT KIPT/KUNV/KAOO/KJST ARND 00Z. OUTLOOK... SUN-WED...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
428 AM EDT SAT SEP 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. HIGH PRESSURE WILL BRING A RETURN OF NEAR NORMAL DAYTIME TEMPERATURES FOR SUNDAY AND CONTINUE INTO THE MIDDLE OF NEXT WEEK. AN UPPER LEVEL LOW MAY LEAD TO A FEW SHOWERS MONDAY OR TUESDAY OVER THE SOUTHERN MOUNTAINS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3AM...THE SURFACE LOW WAS NEAR CHICAGO WITH THE COLD FRONT TRAILING SOUTH THROUGH ILLINOIS. THERE IS GOOD AGREEMENT ON THE TIMING OF THE FRONT...ENTERING WESTERN PA BY ABOUT 18Z...AND MOVING INTO THE SUSQ VALLEY BY 00Z. THERE IS ALSO GOOD AGREEMENT WITH THE PARENT UPPER SHORTWAVE SHEARING OUT THROUGH THE EASTERN LAKES AND SOUTHERN CANADA...LEADING TO A WEAKENING OF THE LARGE SCALE FORCING FOR THE SHOWERS AND THUNDERSTORMS CURRENTLY TRACKING EAST OVER CENTRAL LAKE ERIE DOWN INTO FAR NORTHERN OHIO. EXTRAPOLATION AND HRRR TIMING SUGGEST THESE BEGIN TO ENCROACH ON MY FAR NWRN ZONES BETWEEN ABOUT 7 AND 9 AM...11-13Z. THESE LEADING SHOWERS AND STORMS ARE MADE TO WEAKEN BY THE NEAR TERM MESO MODELS AS THEY MOVE OUT OF THE MOUNTAINS. ADDITIONAL CONVECTION ALONG THE COLD FRONT WILL ORGANIZE TO THE WEST AND ENTER THE NWRN MOUNTAINS ONCE AGAIN BY EARLY TO MID AFTERNOON...WITH A BETTER CHANCE OF SURVIVING INTO THE CENTRAL MOUNTAINS BY LATER TODAY AND THIS EVENING. THE WEAKENING TREND IN THE MODELS IS CONSISTENT AS THE FRONT PUSHES EAST...AND IT REMAINS UNCLEAR HOW MUCH EAST OF A LINE FROM ABOUT WILLIAMSPORT TO STATE COLLEGE TO ABOUT BEDFORD THE RAIN WILL MANAGE TO GET BEFORE PETERING OUT. THE HIGHEST CHANCES FOR RAIN WILL BE OVER NORTHERN AND NORTHWESTERN AREAS WHERE I HAVE CATEGORICAL POPS FOR TODAY. THE NUMBERS TAPER DOWN QUICKLY INTO THE CENTRAL MOUNTAINS AND LOWER STILL OVER MY SERN ZONES. QPF WILL RANGE FROM MEAGER AMOUNTS FROM THE MIDDLE SUSQUEHANNA VALLEY WEST TO THE LAURELS...TO PERHAPS .50" TO .75" OVER THE FAR NW. MODEST INSTABILITY AND MARGINAL WIND PROFILES SHOULD LIMIT SEVERE POTENTIAL TODAY...BUT SPC HAS PAINTED NWRN PA WITH A MARGINAL RISK FOR SEVERE STORMS TODAY. THE BEST CHANCE SEEMS TO BE IF A STRONG LINE CAN FORM IN OHIO/LOWER LAKES AND TRACK INTO THE REGION BEFORE IT DECAYS THIS EVENING. WE`LL EEK OUT ONE MORE WARM DAY AHEAD OF THE COLD FRONT WITH HIGHS IN THE MID 70S TO MID 80S. A COOL DOWN WILL BEGIN TONIGHT AS HIGH PRESSURE PUSHES QUICKLY INTO THE EASTERN GR LAKES AND SHOVES THE COLD FRONT OFF TO THE SOUTH. LOWS WILL RANGE FROM THE CHILLY MID 40S OVER THE NORTH TO AROUND 60 IN THE SOUTHEAST. OVER AREAS WHERE SKIES CLEAR TONIGHT...FOG SEEMS LIKELY LATE. THE BEST CHANCE WOULD SEEM TO BE OVER THE NORTHERN MOUNTAINS. && .SHORT TERM /SUNDAY/... CLOUDS WILL SETTLE OFF TO THE SOUTH SUNDAY AS HIGH PRESSURE QUICKLY MOVES INTO NORTHERN PA/SOUTHERN NY. IT WILL BE A MARKEDLY COOLER DAY WITH HIGHS AVERAGING AROUND 10 DEG COOLER THAN TODAY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... CONFIDENCE IN THE EXTENDED FORECAST CONTINUES TO DWINDLE WITH EACH PASSING MODE RUN. EARLY IN THE PERIOD...MODELS AGREE IN BRINGING FAIRLY AMPLIFIED UPPER TROUGH THROUGH THE OHIO VALLEY INTO THE NERN US. THE RESULTING SOUTH-SOUTHEAST FLOW SHOULD BRING THE CHANCE OF SOME LIGHT RAINS FOR MONDAY AND POSSIBLY TUESDAY. AT THIS POINT I HAVE FAIRLY LOW CHANCES OF RAIN OVER MUCH OF THE AREA MONDAY AND MAINLY OVER SOUTHERN AREAS INTO TUESDAY. BEFORE THIS HAPPENS HOWEVER...WITH CLEAR SKIES...VERY DRY AIR AND LIGHT WINDS...LOWS OVER THE NWRN MOUNTAINS MONDAY MORNING WILL DROP DOWN INTO THE MIDDLE 30S. MAY SEE THE FIRST FROST OF THE SEASON IN A FEW OF THE NORMAL COLD SHELTERED LOCATIONS. FROM THERE MODEL SOLUTIONS DIVERGE FURTHER. THE ECMWF AND GFS/GEFS ALL SHOW THE UPPER TROUGH CLOSING OFF. WHAT HAPPENS THEN MEANS THE DIFFERENCE BETWEEN A MILD AND DRY REST OF THE WEEK...OR A COLD RAINY ONE. THE GFS/GEFS HAVE TRENDED MUCH FURTHER NORTH WITH THE UPPER LOW...KEEPING AN EXTENDED PERIOD OF MOIST EASTERLY LOW LEVEL FLOW FROM WEDNESDAY INTO FRIDAY. THIS WOULD RESULT IN A PERIOD OF CHILLY WET WEATHER. THE ECMWF ON THE OTHER HAND SETTLES THE LOW DOWN OVER THE SERN STATES AND EVEN TRACKS IT WEST ALONG THE GULF COAST FOR THE WEEKEND. THIS WOULD KEEP US UNDER FAVORABLE RIDGING NORTH OF THE SYSTEM...WITH DRY AND MILD CONDITIONS. I USED OUR SUPERBLENDED MODEL MOS WHICH DOWNPLAYS THE GFS/GEFS PESSIMISM...RESULTING IN A MUCH BRIGHTER FORECAST FROM MID WEEK ONWARD. PRESUMING THE OPTIMISTIC FORECAST VERIFIES...TEMPERATURES WHICH WILL START THE WEEK BELOW NORMAL WILL TREND BACK TO A BIT ABOVE NORMAL BY MID WEEK. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... 06Z TAFS SENT. EARLIER DISCUSSION BELOW. RIDGE OF HIGH PRESSURE ALONG THE EAST COAST WILL ENSURE ANOTHER NIGHT OF FAIR WEATHER AND LIGHT WIND ACROSS CENTRAL PA. MAIN AVIATION CONCERN WILL BE EARLY AM FOG...FOCUSED MAINLY ACROSS SOUTHEAST PA...DIRECTLY BENEATH RETREATING SFC RIDGE. A DEVELOPING SOUTHERLY BREEZE AND PATCHY MID LVL CLOUDS WORKING INTO THE WESTERN HALF OF THE STATE SHOULD LIMIT THE FOG POTENTIAL FROM THE CENTRAL MTNS WESTWARD. LATEST HRRR/NAM/LAMP...AS WELL AS LATEST SREF...ALL SUPPORT A LIKELY PERIOD OF IFR/LIFR CONDS AT KLNS BTWN 09Z-14Z. CAN/T RULE OUT OF BRIEF PERIOD OF IFR CONDS AT KIPT/KMDT ARND DAWN. HOWEVER...CONFIDENCE NOT AS HIGH. ANY FOG ACROSS SOUTHEAST PA SHOULD LIFT BY LATE AM. FOCUS WILL THEN SHIFT TOWARD A COLD FRONT PUSHING INTO NORTHWEST PA LATE IN THE DAY. A WEAKENING BAND OF SHRA/TSRA WILL LIKELY PRODUCE A BRIEF VIS REDUCTION AT KBFD LATE IN THE DAY...AND POSSIBLY AT KIPT/KUNV/KAOO/KJST ARND 00Z. OUTLOOK... SUN-WED...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
140 AM EDT SAT SEP 19 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN PLACE THROUGH TOMORROW. A COLD FRONT WILL MOVE INTO THE CAROLINAS FROM THE NORTH ON SUNDAY WITH PRECIPITATION CHANCES INCREASING FOR SUNDAY AND MONDAY. COOLER TEMPERATURES WILL ALSO RETURN ON MONDAY...WITH PERIODIC CHANCES FOR PRECIPITATION CONTINUING INTO THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... AS OF 130 AM...ALL QUIET THUS FAR. VALLEY FOG DEVELOPING IN THE LITTLE TN RIVER VALLEY...AS EXPECTED. TEMP TRENDS LOOK OK. NO CHANGES. AS OF 1030 PM...ANOTHER CLEAR NIGHT ACROSS THE FORECAST AREA AS DRY SURFACE RIDGE REMAINS THE DOMINANT SYNOPTIC SCALE FEATURE ACROSS THE AREA. SLOWLY BUT SURELY INCREASING DEWPOINTS/LOW LEVEL THICKNESS VALUES SHOULD YIELD MIN TEMPS ABOUT A DEGREE WARMER THAN FRIDAY MORNING...OR WITHIN A DEGREE OR SO OF CLIMO. OTHERWISE...FOG/LOW STRATUS SHOULD DEVELOP/EXPAND ACROSS THE LITTLE TENN VALLEY AND ADJACENT DRAINAGES OVER THE NEXT COUPLE OF HOURS...BUT REMAIN SPORADIC ACROSS MOST OF THE OTHER MAJOR VALLEYS. AS OF 735 PM...DEWPOINTS MIXED OUT A BIT THIS AFTERNOON...SO ITS ANOTHER DECENT LATE SUMMER EVENING ACROSS THE FORECAST AREA...WITH LITTLE IN THE WAY OF CLOUD COVER NOW THAT AFTERNOON CU HAS MOSTLY DISSIPATED. TEMPS SHOULD BE IN THE 60S ACROSS MUCH OF THE AREA BY MIDNIGHT. AS OF 230 PM EDT...THE 500 MB RIDGE AXIS OVER THE SRN APPALACHIANS TONIGHT WILL SLOWLY BREAK DOWN FROM THE NORTHWEST ON SATURDAY AS THE NORTHERN TIER BELT OF WESTERLIES SPREADS SOUTHWARD. THE SURFACE HIGH OVER THE FORECAST AREA WILL GET INCREASINGLY PINCHED OVERHEAD BETWEEN LOW PRESSURE OVER THE COASTAL WATERS AND A COLD FRONT APPROACHING FROM THE OH VALLEY. PROFILES OVER OUR AREA WILL STAY RELATIVELY DRY...ALTHOUGH THE NAM AND RAP DO INDICATE PATCHY LOWER STRATUS TRYING TO MAKE A RUN WESTWARD FROM THE COAST INTO THE PIEDMONT OVERNIGHT. MOST CLOUDINESS THROUGH THE PERIOD...HOWEVER... SHOULD BE CONFINED MAINLY TO EARLY MORNING MOUNTAIN VALLEY STRATUS AND THEN A FEW DAYTIME CUMULUS WITH HEATING SATURDAY AFTERNOON. TEMPERATURES WILL CONTINUE TO REBOUND...WITH MINS AT LEAST A CATEGORY ABOVE CLIMO THROUGHOUT OVERNIGHT...AND TWO TO THREE CATEGORIES ABOVE CLIMO FOR MAX TEMPS SATURDAY AFTERNOON. && .SHORT TERM /TONIGHT THROUGH MONDAY/... AS OF 245 PM...A DISTURBANCE WILL REMAIN OFF THE CAROLINA COAST THROUGH THE SHORT RANGE...RESULTING IN LITTLE CHANGE TO THE SENSIBLE WEATHER OVER THE CWA. ON SUNDAY...A WEAK COLD FRONT WILL SWEEP FROM THE NORTHWEST...LIKELY REMAINING WEST OF THE FA BY SUNSET. SKY COVER WILL INCREASE ACROSS THE SOUTHERN APPALACHIAN REGION THROUGH THE DAY. LITTLE TO NO INSTABILITY AND NO FORCING SHOULD RESULT IN DRY WEATHER ON SUNDAY. HIGH TEMPERATURES SHOULD RANGE FROM THE L80S WITHIN THE MTN VALLEYS TO THE U80S EAST. THE WEAK COLD FRONT WILL LIKELY HANG OVER THE SOUTHERN APPALACHIANS EARLY MONDAY MORNING. THE CENTER OF SFC HIGH PRESSURE OVER NEW ENGLAND...THE RIDGE OVER THE REGION ON MONDAY. THE GFS INDICATE THAT WEAK 300 K ISENTROPIC LIFT WILL DEVELOP ACROSS THE REGION DURING THE DAYLIGHT HOURS...SUPPORTED BY LLVL SE FLOW. THE COMBINATION OF ISENTROPIC LIFT...LIGHT UPSLOPE FLOW...AND WIDESPREAD WEAK INSTABILITY SHOULD RESULT IN AN EXPANDING AREA OF SHRA/TSRA ON MONDAY. THICK CLOUDS...RAINFALL...AND DEVELOPING NE SFC WINDS WILL FAVOR HIGH TEMPERATURES BELOW THE MOS CONSENSUS. I WILL FORECAST HIGH TEMPERATURES FROM THE L70S WITHIN THE MTN VALLEYS TO THE L80S ACROSS THE LAKELANDS. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 210 PM FRIDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON TUESDAY WITH AN UPPER TROF AXIS JUST TO OUR WEST AND UPPER RIDGING OVER THE WESTERN CONUS. OVER THE NEXT COUPLE OF DAYS...THE TROF IS EXPECTED TO SLOWLY MOVE OVER THE FCST AREA AND MORPH INTO A CLOSED UPPER LOW BY LATE WED. THE LONG RANGE MODELS KEEP THE LOW SPINNING OVER THE SE REGION INTO FRI WITH BROAD SCALE UPPER RIDGING SPREADING FARTHER EAST OVER THE SAME PERIOD. IT IS NOTABLE THAT THE LATEST 12Z RUN OF THE GFS DOES TRY TO MAINTAIN THE CLOSED LOW ABOUT 24 TO 48 HRS LONGER THAN THE OLDER RUN OF THE ECWMF. AT THE SFC...CANADIAN HIGH PRESSURE WILL BE SLIDING OFF THE NEW ENGLAND COAST BY EARLY TUES WITH A BROAD LOW CENTERED JUST OFF THE CAROLINA COAST. THE EVOLUTION OF THE SFC PATTERN REMAINS FAIRLY UNCLEAR AT THIS POINT...WITH SIG DIFFERENCES BETWEEN THE LONG RANGE MODELS. THE GFS AND THE CMC KEEP THE LOW JUST OFFSHORE WELL INTO THURS WITH ANOTHER CANADIAN HIGH SLIDING EASTWARD IN THE WAKE OF THE PREVIOUS SFC HIGH. THE LOW EVENTUALLY DISSIPATES OVER THE CWFA BY FRI WITH AN EVEN STRONGER HIGH MAKING ITS WAY SOUTHWARD AND TOWARDS THE GREAT LAKES BY THE END OF THE PERIOD. ON THE OTHER HAND...THE ECMWF MOVES THE LOW UP THE EAST COAST ON TUES AND THEN WELL OFFSHORE BY LATE WED ALL WHILE KEEPING HIGH PRESSURE OVER THE FCST AREA THRU THE ENTIRE PERIOD. AS FOR THE SENSIBLE FCST...MORE WEIGHT HAS BEEN PLACED ON A GFS TYPE SOLUTION WITH THE BEST CHANCES FOR PRECIP DURING THE FIRST DAY OR 2 OF THE PERIOD. TEMPS APPEAR MORE CONSISTENT BETWEEN THE MODELS WITH VALUES WARMING A FEW DEGREES THRU THE MEDIUM RANGE NEARING CLIMATOLOGY VALUES FOR MID/LATE SEPT. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AT KCLT AND ELSEWHERE...VFR THRU THE PERIOD. HIGH PRESSURE TO THE NE WILL KEEP A LIGHT N OR NE WIND ACROSS THE REGION THRU SATURDAY EVENING. STILL A POSSIBILITY THAT SOME LOW CLOUDINESS WILL MOVE TOWARD KCLT BY DAYBREAK...BUT EXPECT THAT EVEN IF IT DOES HAPPEN...CLOUD BASE WILL BE VFR. STILL CANNOT RULE OUT VALLEY FOG/LOW STRATUS AT KAVL AROUND DAYBREAK...BUT GOING WITH PERSISTENCE ONCE AGAIN...HAVE LIMITED THE RESTRICTION TO A TEMPO. A FEW STRATOCU MAY DEVELOP AT 060 OR ABOVE THIS AFTERNOON ACROSS THE REGION. OTHERWISE...CLEAR SKY. OUTLOOK...THE POSSIBILITY OF MORNING MOUNTAIN VALLEY FOG AND LOW STRATUS WILL CONTINUE SAT NIGHT INTO SUNDAY MORNING. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON SUNDAY...AND A DEVELOPING MID LEVEL LOW MAY INCREASE THE CHANCES OF LOW CLOUDS AND RAIN ACROSS THE REGION EARLY TO MIDDLE NEXT WEEK. CONFIDENCE TABLE... 05-11Z 11-17Z 17-23Z 23-00Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 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...JPT NEAR TERM...HG/JDL/PM SHORT TERM...NED LONG TERM...JPT AVIATION...PM
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
354 AM CDT SAT SEP 19 2015 .DISCUSSION... .SHORT TERM(TODAY-MON)... COLD FRONT IS CURRENTLY POSITIONED FROM CHI TOWN SW ACROSS NORTHERN TX. UPPER RIDGE AXIS ACROSS THE SOUTHEASTERN U.S. WILL BE SINKING SOUTHWARD AND UPPER LEVEL WESTERLIES SHOULD PREVAIL BY AFTERNOON. THIS WILL ACT TO MOVE THE FRONT OUR WAY. FROPA IS EXPECTED DURING THE LATE AFTERNOON HOURS. MOISTURE AVAILABILITY FOR THE APPROACHING FRONT WILL BE VERY LIMITED. IT DOES APPEAR THAT JUST ENOUGH INSTABILITY WILL RESIDE SO AS TO PROMOTE A LOW 20 POP FOR MOST OF THE AREA FOR TODAY AND THIS EVENING. THE ASSOCIATED UPPER LEVEL DYNAMICS WILL TAKE A NORTHERLY ROUTE...WELL NORTH OF TN. HRRR IS VERY STINGY WITH ANY APPRECIABLE PRECIP WITH THIS SYSTEM. WILL THEREFORE KEEP THE EXPECTED QPF FIELDS ON THE LOW SIDE. AT ANY RATE...CLOUDS WILL INCREASE SLOWLY BETWEEN NOW AND THIS EVENING. MOSTLY CLOUDY SKIES SHOULD PREVAIL FOR TONIGHT AND EARLY SUNDAY. THEN...WE`LL LEAN TOWARD PARTIAL CLOUD COVER. FOR THE NEAR TERM TEMPS...WARM AGAIN FOR TODAY. HIGHS WILL BE WELL INTO THE 80S FOR MOST AREAS. THE COOL DOWN WILL BEGIN TONIGHT AFTER THE FROPA. SUNDAY AND MONDAY WILL FEATURE HIGHS NEAR 80 WEST OF PLATEAU...WITH DEW POINTS IN THE 50S. OVERNIGHT LOWS WILL GENERALLY BE FROM 55 TO 60 FOR SUNDAY NIGHT...ABOUT 5 DEGREES COOLER THAN SAT NT. .LONG TERM(TUE-SAT)... DISCREPANCIES BETWEEN MODEL SOLUTIONS STILL REMAIN WITH THIS MORNING`S RUNS...BUT A GENERAL TREND FOR MID TO LATER PORTIONS OF THE WORK WEEK TOWARD A COMPLETELY DRY FORECAST...WITH THE ONLY POTENTIAL OF RAINFALL POSSIBLY THE FIRST PART OF NEXT WEEKEND...AND EVEN THEN ONLY A SLIGHT CHANCE OF SHWRS ACROSS THE ERN HALF OF THE MID STATE. TEMPS WILL GENERALLY BE AROUND OR MAYBE A FEW DEGREES HERE AND THERE ABOVE SEASONAL NORMAL VALUES. MOSTLY CLEAR TO PTCLDY SKIES ARE CONTINUED TO BE EXPECTED THRU THIS PERIOD TOO. BROAD SURFACE HIGH PRESSURE INFLUENCES ALONG WITH BUILDING UPPER LEVEL RIDGING INFLUENCES WILL BE THE MAJOR WX PLAYER THRU THIS PERIOD. DEPENDING ON MODEL LEAN...UPPER LEVEL CLOSED LOW CIRCULATION THAT PREVIOUSLY WAS EXPECTED TO PLAY A ROLE IN BRINGING CONVECTIVE CHANCES TO THE MID STATE PLATEAU WED AFTERNOON AND ON FRI... LOOKS TO DEVELOP BY THE MID PORTION OF NEXT WORK WEEK IN AN UPPER LEVEL TROUGHING PATTERN OVER THE CAROLINA`S AND EITHER EVENTUALLY GO NEWD OF OR SWD OF MID STATE...GENERALLY RESULTING IN NO SIGNIFICANT IMPACTS TO THE MID STATE. MENTION OF ISO SHWRS ON SAT PER POSSIBILITY OF SOME MOISTURE BEING USHERED ACROSS ERN HALF IF CIRCULATION ACTUALLY MOVES NEWD. .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 88 63 80 59 / 20 20 10 10 CLARKSVILLE 86 58 78 54 / 30 10 10 10 CROSSVILLE 82 62 77 57 / 10 20 20 10 COLUMBIA 88 62 80 58 / 20 20 10 10 LAWRENCEBURG 87 63 80 59 / 10 10 10 10 WAVERLY 87 59 78 56 / 20 20 10 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21
AREA FORECAST DISCUSSION
NWS AMARILLO TX
459 AM CDT SAT SEP 19 2015 .DISCUSSION... EARLY THIS MORNING THE SURFACE COLD FRONT HAD PROGRESSED WELL TO THE SOUTH OF THE PANHANDLES WITH NORTHEASTERLY SURFACE WINDS IN ITS WAKE. COOLER TEMPERATURES HAVE ARRIVED WITH UPPER 40S AT BOISE CITY AND KENTON. POST-FRONTAL STRATUS SHOULD BE QUITE EXTENSIVE TODAY AS IS EVIDENT BY WEAK ISENTROPIC ASCENT. THIS WILL LIMIT TEMPERATURES AND HAVE WENT ON THE COOL SIDE OF GUIDANCE WHICH MAY NOT BE COOL ENOUGH. THIS IS A DOWNWARD TREND FROM PREVIOUS FORECAST. HAVE STRUGGLED TO FIND A NOTABLE SOURCE FOR LIFT SUFFICIENT FOR PRECIPITATION. MODEL FORECAST SOUNDINGS SHOW A RELATIVELY SHALLOW SATURATION WITHIN THE FRONTAL INVERSION. IF SATURATION IS DEEP ENOUGH FOR ELEVATED CONVECTION IT WOULD BE IN THE SOUTHEAST TEXAS PANHANDLE NEAR WHERE ISOLATED SHOWERS AND THUNDERSTORMS HAVE PERSISTED MUCH OF THE NIGHT BUT CONFIDENCE IS LOW. LOW LEVEL FLOW WILL GRADUALLY BECOME MORE SOUTHEASTERLY BY TOMORROW EVENING AND SLIGHTLY DEEPER MOISTURE ADVECTS NORTHWARD INTO THE AREA. IN THIS SCENARIO SOME CONVECTIVE DEVELOPMENT MAY OCCUR DURING THE EVENING PARTICULARLY ACROSS THE NORTHEASTERN PORTION OF THE AREA AS LOW LEVEL JET STRENGTHENS AND THIS MAY PERSIST INTO SUNDAY MORNING. ANOTHER SHORTWAVE IS DEPICTED TO MOVE THROUGH LATE SUNDAY AND BY THAT TIME CLEARING AND INCREASED DIABATIC HEATING WILL BE SUFFICIENT FOR AT LEAST MODEST INSTABILITY AND SOME DIURNAL CONVECTION LATE SUNDAY LASTING INTO EARLY SUNDAY EVENING. SUBSIDENCE BEHIND THIS WAVE SHOULD BRING AN END TO ANY CONVECTION THAT DOES FORM BY MID EVENING. EARLY NEXT WEEK THE MODELS BUILD AN UPPER RIDGE ACROSS THE SOUTHERN PLAINS RESULTING IN WARMER TEMPERATURES AND DRIER CONDITIONS. A PLUME OF DEEP MOISTURE IS SHOWN TO MOVE NORTHWARD INTO THE DESERT SOUTHWEST ON THE WESTERN SIDE OF THIS RIDGE AND AHEAD OF A CLOSED UPPER LOW APPROACHING THE COAST OF BAJA CALIFORNIA. BY LATE TUESDAY A WEAK SHORTWAVE AHEAD OF THE OPENING CLOSED LOW IN COMBINATION WITH INCREASING MOISTURE MAY LEAD TO SOME CONVECTION IN THE FAR NORTHWEST. BETTER CHANCES WILL ARRIVE WEDNESDAY AS THE MAIN SHORTWAVE APPROACHES. TIMING AND AMPLITUDE DIFFER IN THE MEDIUM RANGE MODELS DIFFER AT THIS TIME RANGE LEADING TO SOME UNCERTAINTY. BRB && .PRELIMINARY POINT TEMPS/POPS... AMARILLO TX 55 84 61 90 65 / 20 20 20 0 0 BEAVER OK 58 83 60 92 66 / 30 20 10 0 0 BOISE CITY OK 53 85 57 92 63 / 10 5 0 0 0 BORGER TX 59 86 64 92 68 / 20 20 10 0 0 BOYS RANCH TX 58 87 60 91 65 / 20 20 5 0 0 CANYON TX 56 84 60 90 63 / 20 20 20 0 0 CLARENDON TX 60 83 62 91 65 / 30 20 20 0 0 DALHART TX 56 88 58 92 62 / 10 10 5 0 0 GUYMON OK 56 86 60 93 65 / 20 10 5 0 0 HEREFORD TX 56 85 60 90 63 / 20 20 10 0 0 LIPSCOMB TX 60 81 62 90 67 / 30 30 20 0 0 PAMPA TX 59 84 62 91 65 / 30 20 20 0 0 SHAMROCK TX 61 80 62 89 65 / 30 30 20 0 0 WELLINGTON TX 63 81 63 90 66 / 30 30 20 0 0 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 15/17
  [top] Area Forecast Discussion National Weather Service Midland/Odessa TX 423 AM CDT SAT SEP 19 2015 .DISCUSSION...As of 4:00 AM CDT Saturday...a brief respite from the heat this weekend. Sfc obs and KMAF radar is indc that a cold front is currently over the Central Permian Basin. A few small thunderstorms are popping up behind the front. There are also a few thunderstorms along the Rio Grande in Northwest Presidio County along the edge of a large MCS centered over portions of Sonora and Chihuahua Mexico. The HRRR and RAP13 hi-res models move the cold front slowly south this morning...stalling near or north of I-10 this aftn. With good low-level convergence and weak mid level impulses the hi-res models bring a good shot of convection along the I-20 corridor this morning...moving south this aftn. The main impacts from the thunderstorms will be locally heavy rain and gusty winds. With the rain potential and cloud cover it will be significantly cooler than yesterday...in fact today should be the coolest day this month. Have continued convective chances tonight with the front over the CWA. The cold front will retreat north/wash out on Sunday as a ridge builds back into the Southern Plains/Rockies. Temps will warm to near seasonal levels on Sunday with a slight chance of thunderstorms. A blocking pattern develops over the CONUS next week with a trough along both coasts and a ridge over the Central US. Shortwaves will ride over the ridge...occasionally flattening it slightly. The Davis Mtns...and even more so the Guadalupe Mtns will be on the eastern edge of any convective activity into mid week. Otherwise...the rest of the CWA will be dry. Even though the center of the H85 thermal ridge will be just west of the CWA expect temps next week to be 5-10 degrees above normal...with widespread low 90s and even a few mid 90s across the lower elevations. Widespread 80s are expected in the Mtns...with upper 80s along the extreme northern portions of the CWA. The latest GFS ensemble forecasts keeps West Texas/Southeast New Mexico dry with above normal temperatures through the end of September and into the first several days of October. Strobin && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 81 64 88 64 / 50 30 20 10 CARLSBAD NM 76 66 87 65 / 40 50 30 10 DRYDEN TX 96 73 94 70 / 20 20 10 10 FORT STOCKTON TX 88 68 89 66 / 40 40 20 10 GUADALUPE PASS TX 71 60 80 62 / 40 50 30 10 HOBBS NM 78 63 84 64 / 30 50 20 10 MARFA TX 81 58 80 57 / 30 30 20 20 MIDLAND INTL AIRPORT TX 84 67 88 66 / 50 40 20 10 ODESSA TX 82 67 87 68 / 50 40 20 10 WINK TX 85 68 88 67 / 50 50 20 10 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 72/33
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
240 AM CDT SAT SEP 19 2015 .DISCUSSION... THE COLD FRONT WAS LOCATED ALONG A LINE FROM FORT SMITH TO SOUTH OF LUBBOCK AT 07Z/2AM AND MOVING SOUTHEAST NEAR 18 MPH. AN OUTFLOW BOUNDARY AHEAD OF CONVECTION ALONG/BEHIND THE FRONT WILL WORK THROUGH THE NORTHWEST HALF OF THE CWA THIS MORNING WITH CONVECTION SPREADING SOUTHEASTWARD AS WELL. THE HRRR AND TT WRF SPREAD CONVECTION INTO THE NORTHWEST HALF OF THE DFW METROPLEX 10-12Z SO HAVE MAINTAINED CHANCE POPS OVER THE NORTHWEST HALF TODAY. THE FRONT WILL LIKELY MOVE TO NEAR A PALESTINE TO GOLDTHWAITE LINE BY MIDNIGHT TONIGHT...THEN DRIFT NORTHWARD A LITTLE EARLY SUNDAY AND STALL OUT JUST SOUTH OF I-20 DURING THE DAY WITH THE BEST CHANCE OF CONVECTION GENERALLY NORTH OF THE FRONT. THE WEST END OF THE FRONT LIFTS NORTHWARD ON SUNDAY NIGHT AND THEN THE ENTIRE FRONT LIFTS OUT NORTHEAST ON MONDAY. SUNDAY NIGHT POPS WILL SHIFT TO THE NORTHEAST COUNTIES AND MONDAY POPS WILL BE MAINLY OVER THE FAR EASTERN COUNTIES. SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING DUE TO A FAIR AMOUNT OF INSTABILITY ALONG THE FRONT....AND LOCALIZED HEAVY RAINFALL IS ALSO POSSIBLE DUE TO PWATS NEAR/AROUND 2 INCHES. HIGH TEMPERATURES TODAY WILL NOT CHANGE AHEAD OF THE FRONT BUT THEY WILL BE 5-10 DEGREES COOLER BEHIND IT. AS THE FRONT BECOMES DIFFUSED ON SUNDAY AND LIFTS OUT ON MONDAY...HIGH TEMPS WILL CREEP UPWARD WITH MOST OF THE CWA BACK IN THE LOWER TO MID 90S TUESDAY THROUGH FRIDAY. HAVE ADJUSTED OVERNIGHT LOWS DOWN 1-3 DEGREES...MAINLY RURAL AREAS...THURSDAY AND FRIDAY DUE TO DRIER AIR SPREADING INTO THE REGION. LOOKING AHEAD INTO NEXT WEEKEND AND THE LAST WEEK OF SEPTEMBER...BOTH THE GFS AND ECMWF MODELS ARE INDICATING A WEAKNESS ALOFT OVER THE SOUTHEAST OR SOUTHERN STATES AND THE UPPER RIDGE OFF TO OUR WEST. THIS PATTERN WOULD RESULT IN LOWER HEIGHTS ALOFT OVER NORTH AND CENTRAL TEXAS...AND THUS TEMPERATURES A LITTLE CLOSER TO NORMAL WITH HIGHS IN THE MID 80S TO LOWER 90S. 75 && .AVIATION... /ISSUED 1153 PM CDT FRI SEP 18 2015/ NOT MUCH CHANGE FROM THE 00Z FORECAST WITH GENERALLY VFR CONDITIONS THROUGH SATURDAY AND INCREASING CLOUD COVER ASSOCIATED WITH AN APPROACHING COLD FRONT. THE COLD FRONT CONTINUES TO MAKE STEADY PROGRESS SOUTHWARD LATE THIS EVENING AND SHOULD APPROACH THE METROPLEX TAF SITES JUST AFTER DAYBREAK WHICH IS A FEW HOURS EARLIER THAN PREVIOUSLY THOUGHT. THE ARRIVAL OF THE FRONT WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS. HOWEVER...MOISTURE AND UPPER LEVEL SUPPORT WILL BE SOMEWHAT LIMITED SO WILL ONLY MENTION VCTS AT THE METROPLEX TERMINALS. THE FRONT SHOULD STALL NORTH OF WACO AND STORM CHANCES WILL BE EVEN LOWER THERE. EXPECT SOUTHERLY WINDS BETWEEN 8 AND 12 KNOTS AHEAD OF THE COLD FRONT. THE WIND WILL TURN TO THE NORTH/NORTHEAST AT THE METROPLEX TERMINALS BETWEEN 13 AND 15Z AND REMAIN FROM THE NORTHEAST THROUGH SATURDAY EVENING. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 88 72 90 72 92 / 40 30 20 10 5 WACO, TX 93 70 95 71 93 / 20 10 10 5 5 PARIS, TX 87 67 87 66 87 / 30 20 30 30 20 DENTON, TX 87 69 89 68 91 / 40 40 20 20 5 MCKINNEY, TX 88 69 90 69 90 / 40 30 20 20 10 DALLAS, TX 89 73 90 71 92 / 40 30 20 10 5 TERRELL, TX 91 69 91 69 91 / 20 20 20 20 10 CORSICANA, TX 94 71 93 71 92 / 10 10 10 5 10 TEMPLE, TX 93 69 93 70 92 / 10 10 5 5 5 MINERAL WELLS, TX 87 67 90 68 91 / 40 40 20 10 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ /75
AREA FORECAST DISCUSSION
NWS ALBANY NY
1104 AM EDT SAT SEP 19 2015 .SYNOPSIS... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT...BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1045 AM EDT...SUNNY TO MOSTLY SUNNY AROSS THE REGION WITH THE EXCEPTION OF THE CONNECTICUT VALLEY IN SOUTHEAST VERMONT WHERE STRATUS IS STILL HANGING ON...BUT IT SHOULD BURN OFF BY AROUND NOON. WIDESPREAD CLOUDINESS ALSO SEEN OVER LAKE ONTARIO...WHICH WILL BEGIN TO SPREAD INTO THE ADIRONDACKS DURING THE AFTERNOON. HAVE ONLY MADE SOME MINOR TEMP ADJUSTMENTS...AND ASLO SOME ADJUSTMENTS TO THE SKY COVER GRIDS TO REFLECT CURRETN CONDITIONS... OTHERWISE THE PREVIOUS FORECAST WAS IN GOOD SHAPE. PREVIOUS DISCUSSION... ADDITIONAL CLOUDS INCREASE FROM THE WEST ASSOCIATED WITH A COLD FRONT APPROACHING FROM THE GREAT LAKES LATE IN THE DAY. ONE MORE WARM DAY IS EXPECTED...WITH SUNSHINE AND A SOUTHERLY FLOW RESULTING IN HIGH TEMPS IN THE UPPER 70S TO LOWER 80S. MOST OF THE AREA SHOULD REMAIN DRY THROUGH THE DAYLIGHT HOURS. HOWEVER...CHANCES FOR SHOWERS WILL START TO INCREASE FOR THE WESTERN ADIRONDACKS/MOHAWK VALLEY LATE IN THE DAY AS THE COLD FRONT MOVES INTO WESTERN NY. BASED ON TIMING FROM HRRR AND LOCAL HI-RES WRF...WILL ONLY MENTION 20-30 POPS FOR HERKIMER/HAMILTON COUNTIES THROUGH 6 PM TODAY. THE BULK OF THE SHOWERS WILL ARRIVE AFTER DARK. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SHOWERS WILL BE MOVING INTO WESTERN PORTIONS OF THE AREA EARLY THIS EVENING...PRECEDING A COLD FRONT PUSHING EASTWARD ACROSS NY STATE. MODELS INDICATING A NARROW RIBBON OF WEAK INSTABILITY JUST AHEAD OF THE FRONT...SO WILL MENTION ISOLATED THUNDER ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. SOME BRIEF GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE LINE OF SHOWERS/STORMS FOR THIS AREA...BUT THERE WILL NOT BE ENOUGH INSTABILITY TO SUSTAIN TALL ENOUGH UPDRAFTS TO PRODUCE STRONGER WINDS. MODELS INDICATE THE LINE OF SHOWERS WILL BE WEAKENING SOMEWHAT AS THEY MOVE EAST DURING THE LATE EVENING AND OVERNIGHT HOURS. SO WILL MAINLY MENTION CHANCE POPS FOR MUCH OF THE AREA WITH LIGHT QPF AMOUNTS. THE COLD FRONT AND ANY ASSOCIATED SHOWERS SHOULD CLEAR THE ENTIRE AREA BY DAYBREAK SUNDAY. WINDS WILL BECOME NORTHERLY BEHIND THE FRONT AND WILL BE NOTICEABLE ALONG WITH COOLER TEMPERATURES. HIGHS ARE ONLY EXPECTED TO BE IN THE 60S TO NEAR 70...WHICH IS NEAR NORMAL BUT MUCH COOLER THAN RECENT DAYS. CLOUDS WILL DECREASE THROUGHOUT THE DAY AS HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE AREA. HIGH PRESSURE WILL SETTLE IN OVER THE REGION SUNDAY NIGHT INTO MONDAY MORNING...RESULTING IN CLEAR SKIES AND LIGHT WINDS. THESE CONDITIONS WILL ALLOW FOR THE COOLEST OVERNIGHT TEMPERATURES WE HAVE SEEN IN THREE MONTHS. LOWS ARE FORECAST TO BE IN THE UPPER 30S TO MID 40S...WITH PATCHY FROST POSSIBLE FOR SOME AREAS NORTH AND EAST OF ALBANY. THE LAST DAY ALBANY OFFICIALLY HAD A TEMPERATURE IN THE 40S WAS BACK ON JUNE 20TH...WHICH WAS 49 DEGREES THAT MORNING. TRANQUIL WEATHER WILL PERSIST MONDAY AND MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN CONTROL. TEMPERATURES LOOK TO BE CLOSE TO NORMAL. MONDAY NIGHT WILL LIKELY NOT BE AS COLD AS THE PREVIOUS NIGHT DUE TO SOME POSSIBLE ADDED CLOUD COVER AND A SLIGHT EASTERLY BREEZE...AS THE CENTER OF THE HIGH PRESSURE SYSTEM RETREATS TOWARDS THE CANADIAN MARITIMES. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE LONG TERM PERIOD STARTS OUT DRY AND SEASONABLE AS A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM THE OHIO VALLEY NORTHEASTWARD INTO THE NORTHEASTERN US. A WEAK COLD FRONT IS EXPECTED TO DROP SOUTHEAST FROM SOUTHERN CANADA THROUGH THE NORTHEAST ON WEDNESDAY AND STALL ACROSS THE MIDDLE ATLANTIC REGION ON THURSDAY. AT THIS TIME EXPECT THE FRONTAL PASSAGE WILL BE DRY WITH MODEL GUIDANCE INDICATING LITTLE IF ANY MOISTURE WITH THE FRONTAL BOUNDARY. FRIDAY AT THIS POINT IS A DIFFICULT FORECAST AS THE MODELS DIVERGE ON WHETHER OR NOT MOISTURE FROM THE SOUTH LIFTS NORTH WITH THE FRONTAL BOUNDARY STALLED JUST TO OUR SOUTH. AT THIS TIME THE GFS LIFTS MOISTURE NORTHWARD ACROSS OUR REGION ON FRIDAY WHILE THE ECMWF IS DRY WITH HIGH PRESSURE REMAINING IN CONTROL OF OUR WEATHER. FOR NOW WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR FRIDAY. TEMPERATURES FOR THE LONG TERM PERIOD WILL BE SEASONABLE TO SLIGHTLY BELOW NORMAL. EXPECT HIGHS TUESDAY TO BE IN THE MID 60S TO MID 70S WITH HIGHS ON WEDNESDAY AND THURSDAY IN THE UPPER 60S TO MID 70S AND HIGHS ON FRIDAY IN THE 60S TO AROUND 70 ALTHOUGH IT COULD BE COOLER IF THE GFS IS CORRECT. LOWS WILL BE IN THE 40S TO LOWER 50S TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... FOR TODAY EXPECTING SOME HIGH CLOUDS TO STREAM IN AND EVENTUALLY MID CLOUDS THIS AFTERNOON TO MOVE IN AHEAD AN APPROACHING COLD FRONT. THIS BOUNDARY WILL USHER A MUCH COOLER AND MORE SEASONABLE AIR MASS INTO THE REGION WITH ITS PASSAGE TONIGHT. HAVE INCLUDED -SHRA FOR KGFL AFTER 03Z AND VCSH FOR KALB...KPSF AND KPOU BTWN 03Z AND 05Z AS SHOWERS WILL BE DIMINISHING IN COVERAGE AS THEY MOVE SOUTH AND EAST. CIGS WILL ALSO LOWER TO OVC035-050 BTWN 03Z AND 05Z. SKIES WILL THEN BECOME SCT035-045 LATE TONIGHT IN THE WAKE OF THE COLD FRONT. CALM WINDS WILL BECOME SOUTHERLY TODAY AS THE FLOW WILL PICK UP DURING THE DAY TO 8 TO 12 KNOTS WITH SOME 15-22 KTS EXPECTED AT KGFL...KPSF AND ESPECIALLY KALB DURING THE AFTERNOON. WINDS WILL REMAIN BTWN 08-12 KTS THIS EVENING BEFORE SHIFTING TO THE WEST- NORTHWEST WITH THE FRONTAL PASSAGE LATE TONIGHT. OUTLOOK... SUN-WED: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. MINIMUM RELATIVE HUMIDITY VALUES TODAY WILL BE AROUND 45 TO 50 PERCENT...INCREASING TO MAXIMUM VALUES OF 85 TO 100 PERCENT TONIGHT. MIN RH VALUES ON SUNDAY ARE FORECAST TO BE BETWEEN 35 AND 45 PERCENT. WINDS TODAY WILL BE SOUTHERLY AROUND 10 TO 15 MPH...BECOMING NORTHWEST AT 5 TO 15 MPH TONIGHT AS A COLD FRONT PASSES THROUGH. WINDS ON SUNDAY WILL BECOME NORTHERLY AROUND 5 TO 15 MPH. && .HYDROLOGY... NO HYDROLOGIC CONCERNS THROUGH THE NEXT FIVE DAYS. DRY CONDITIONS WILL PERSIST THROUGH MUCH OF TODAY. A COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST TONIGHT WITH MAINLY SCATTERED SHOWERS EXPECTED. SHOWERS WILL BE MORE NUMEROUS ACROSS THE WESTERN ADIRONDACKS WHERE ONE QUARTER TO ONE THIRD OF AN INCH OF RAINFALL IS POSSIBLE. ELSEWHERE GENERALLY A TENTH OF AN INCH OR LESS IS EXPECTED. THE RAINFALL WILL HAVE LITTLE...IF ANY IMPACT ON AREA RIVERS. DRY CONDITIONS RETURN FOR SUNDAY AND WILL LIKELY LAST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH ANOTHER AREA OF HIGH PRESSURE BUILDING IN. RIVER FLOWS WILL CONTINUE TO RECEDE INTO NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...GJM/JPV SHORT TERM...JPV LONG TERM...11 AVIATION...11 FIRE WEATHER...JPV HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1002 AM EDT SAT SEP 19 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL TODAY...WITH A COLD FRONT BRINGING JUST A FEW SHOWERS LATE TONIGHT INTO EARLY SUNDAY. HIGH PRESSURE THEN BUILDS INTO NORTHERN NEW ENGLAND FOR MUCH OF NEXT WEEK. LOW PRESSURE WELL OFFSHORE TO THE SOUTH MAY BRING SHOWERS CLOSE TO THE ISLANDS TUESDAY...OTHERWISE DRY WEATHER THROUGH THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE... ALLOWED THE DENSE FOG ADVISORY TO EXPIRE NATURALLY AS MOST LOCATIONS HAD LIFTED TO AT LEAST 0.5 MILES OR HIGHER. STILL SOME AREAS WHERE FOG IS HANGING IN...BUT VSBYS ALL SHOWING SIGNS OF RISING. OTHERWISE...FORECAST REQUIRED A BIT MORE MANUAL ADJUSTMENT THIS MORNING AS THE STRATUS DEC CONTINUES TO HOLD FAST AS OF 1O AM. SKIES WERE THE FIRST THING THAT NEEDED ADJUSTING. HOWEVER...THIS IS ALSO IMPACTING THE TEMPS...AND ARE LIKELY TO IMPACT THE HIGHS THIS AFTERNOON. GUIDANCE...EVEN IN THE SHORT TERM ARE NOT REALLY HANDLING THIS WELL. SO STARTED WITH A BASELINE OF 2M HRRR TEMPS COMBINED WITH OUR IN-HOUSE BIAS CORRECTED MAV. THIS PRESENTED A GOOD FOUNDATION BUT THEN MADE MANUAL EDITS FROM THERE BASED ON THE TIMING OF CLOUD COVER CLEARING. THE OVERALL FINAL NUMBERS ARE A BIT LOWER THAN PREVIOUS. PREVIOUS DISCUSSION... AFTER ANY EARLY MORNING FOG BURNS OFF...EXPECTING ANOTHER MOSTLY SUNNY...WARM DAY BEFORE A COLD FRONT MOVES THROUGH TONIGHT. HIGH TEMPERATURES ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S MOST LOCATIONS. SLIGHTLY COOLER TEMPERATURES EXPECTED ALONG THE SOUTH COAST WITH AN ONSHORE WIND. INCREASING DEWPOINTS WILL LEAD TO A MORE HUMID FEELING TO THE DAY...BUT IT SHOULD NOT FEEL OPPRESSIVE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... TONIGHT...LOW PRESSURE MOVES THROUGH QUEBEC BRINGING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND. THERE IS ENOUGH MOISTURE AVAILABLE... AS INDICATED BY K INDICES...FOR SHOWERS TO DEVELOP. INSTABILITY AND MID LEVEL LAPSE RATES ARE LACKING SO NO THUNDER IS EXPECTED. NOT EXPECTING WIDESPREAD RAIN OVERNIGHT BUT SOME LOCATIONS WILL LIKELY HAVE A SHOWER OR TWO. DESPITE ABOVE NORMAL PWAT VALUES...RAINFALL AMOUNTS WILL BE LESS THAN A QUARTER INCH. NOT ENOUGH TO MAKE MUCH OF A DIFFERENCE IN THE RAINFALL DEFICIT. INCREASING CLOUDS...CHANCE OF SHOWERS...AND INCREASED DEWPOINTS... WILL COMBINE TO KEEP OVERNIGHT TEMPERATURES A BIT WARMER THAN PREVIOUS NIGHTS. THE ONLY EXCEPTION TO THIS MAY BE IN NORTHWESTERN MASSACHUSETTS WHERE COLD ADVECTION BEHIND THE FRONT MAY BEGIN BY THE EARLY MORNING HOURS. SUNDAY...MOST PRECIP SHOULD HAVE COME TO AN END BY SUNRISE SUNDAY MORNING. THERE IS A LOW PROBABILITY THAT A FEW SHOWERS MAY LINGER ON THE CAPE AND ISLANDS EARLY BEFORE THE FRONT PUSHES OFFSHORE. HIGH PRESSURE BUILDS INTO NORTHERN NEW ENGLAND BRINGING DRY WEATHER TO THE REGION. EXPECT STRONG COLD ADVECTION TO HOLD OFF UNTIL AFTER SUNSET SUNDAY SO MUCH OF THE DAY WILL BE PLEASANT WITH SUNNY SKIES AND MORE SEASONABLE TEMPERATURES. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... BIG PICTURE... UPPER TROUGH OVER THE GULF OF ALASKA WITH NEAR-ZONAL FLOW ACROSS THE PACIFIC NORTHWEST AND CANADA. SOUTHERN NEW ENGLAND REMAINS SOUTH OF THIS NORTHERN JET THROUGH THE FORECAST PERIOD. SOUTHERN STREAM UPPER LOW LOITERS OVER THE SOUTHEAST USA THROUGH THE WEEK. THE GFS EJECTS THIS LOW TOWARD NEW ENGLAND AT THE END OF THE WEEK WHILE THE ECMWF MOVES IT SOUTHWEST TOWARD THE GULF OF MEXICO. THE LARGE SCALE PATTERN IS DRY AND WARM WITH 500 MB CONTOURS MOSTLY ABOVE NORMAL. HOWEVER A LOW LEVEL EAST/NORTHEAST FLOW WOULD BUFFER SURFACE TEMPS SEVERAL DEGREES...CLOSER TO NORMAL OR A LITTLE BELOW. THE DAILIES... SUNDAY NIGHT-MONDAY... HIGH PRESSURE BUILDS OVER NORTHERN NEW ENGLAND WITH SHORTWAVE RIDGE ALOFT. THIS SHOULD PROVIDE GENERAL SUBSIDENCE. POSITIONING OF THE HIGH CENTER WILL BRING A NORTHEAST FLOW ACROSS SOUTHERN NEW ENGLAND...STRONGEST NEAR THE EAST MASSACHUSETTS SHORE. THIS SUGGESTS MOSTLY CLEAR SKIES WITH LIGHT WIND INLAND AND A BUFFERING EAST/NORTHEAST WIND FLOW NEAR THE EASTERN SHORE. RADIATIONAL COOLING SUNDAY NIGHT SHOULD BRING SFC TEMPS TO NEAR THE DEW POINT. INLAND DEWS WILL BE IN THE UPPER 30S TO LOWER 40S...COASTAL DEWS IN THE MID 40S TO LOWER 50S. EAST FLOW WILL LIMIT MIXING DEPTHS...BASED ON TEMPS AT 900 MB THIS WOULD SUPPORT MONDAY MAX TEMPS IN THE MID AND UPPER 60S NEAR THE SHORE AND LOWER 70S INLAND. TUESDAY THROUGH THURSDAY... HIGH PRESSURE IN CONTROL MUCH OF THE TIME OVER NEW ENGLAND. A WEAK SHORTWAVE MOVES THROUGH THE REGION WEDNESDAY WITH VERY LIMITED MOISTURE NOTED ON THE MODELS. MAYBE ENOUGH FOR A PERIOD OF CLOUDS...BUT NO PCPN. FRIDAY...THE ECMWF BUILDS CANADIAN HIGH PRESSURE OVER THE REGION WITH A NORTHWEST UPPER FLOW. THE GFS IS MORE SHALLOW WITH A SHORTWAVE OVER QUEBEC FRIDAY AND FRIDAY NIGHT...ALSO FARTHER NORTH WITH SOUTHERN STREAM UPPER LOW MOVING THROUGH CAROLINAS INTO DELMARVA AREA. THIS BRINGS SHOWERS FARTHER NORTH ON FRIDAY AS WELL AS THE LEFT FRONT QUADRANT OF ASSOCIATED UPPER JET. THE ECMWF SCENARIO IS FOR DRY WEATHER. THE GFS SCENARIO WOULD SUGGEST A CHANCE OF SHOWERS ON FRIDAY...BUT ITS SUDDEN APPEARANCE ON THIS RUN AND IN THE FINAL PERIOD OF THE FORECAST DOES NOT GENERATE A LOT OF CONFIDENCE. WE WILL GO WITH THE DRY ECMWF SCENARIO. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SUNDAY/...HIGH CONFIDENCE. VFR. AREAS OF IFR/LIFR IN MORNING FOG...ESPECIALLY IN THE CT VALLEY AND IN RI/SOUTHEAST MASS. BUT THIS FOG WILL THIN THROUGH THE MORNING. BRIEF MVFR CONDITIONS POSSIBLE IN SCT SHRA TONIGHT. SURFACE WINDS SHIFT FROM SOUTH TO NORTH ON SUNDAY AS A COLD FRONT MOVES THROUGH. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...MODERATE TO HIGH CONFIDENCE. VFR THROUGH THE PERIOD. NORTHEAST TO EAST WINDS ARE EXPECTED MONDAY WITH GUSTS 20 TO 25 KNOTS MAINLY ACROSS CAPE COD AND ISLANDS. EAST TO NORTHEAST FLOW CONTINUES THROUGH MIDWEEK WITH LIGHTER WINDS IN THE INTERIOR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SUNDAY/...HIGH CONFIDENCE. FOG MAY LIMIT VISIBILITIES THIS MORNING...BUT SHOULD THIN DURING THE MORNING HOURS. THEN HIGH PRESSURE OVER THE WATERS WILL BRING LIGHT WINDS AND CALM SEAS THROUGH SUNDAY MORNING. WINDS AND SEAS BUILD SUNDAY AFTERNOON AS A COLD FRONT CROSSES THE WATERS. SCA CONDITIONS MAY OCCUR BY SUNDAY EVENING. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE. HIGH PRESSURE BUILDS OVER NORTHERN NEW ENGLAND WITH EAST TO NORTHEAST WINDS ACROSS THE MASS AND RI COASTAL WATERS. LOW LEVEL FLOW SUPPORTS WINDS 20 TO 25 KNOTS SUNDAY NIGHT AND MONDAY THEN DIMINISHING. THESE WINDS WILL MAINTAIN 5 TO 7 FOOT SEAS ON THE OUTER WATERS AND MASS BAY...POSSIBLY CAPE COD BAY. WINDS DIMINISH THROUGH MIDWEEK WHILE SEAS SUBSIDE VERY SLOWLY. SMALL CRAFT ADVISORY CONTINUES THROUGH AT LEAST MONDAY...AND POSSIBLY LINGERING SMALL CRAFTS FOR SEAS ON THE OUTER WATERS THROUGH MIDWEEK. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...WTB/RLG NEAR TERM...DOODY/RLG SHORT TERM...RLG LONG TERM...WTB AVIATION...WTB/RLG MARINE...WTB/RLG
AREA FORECAST DISCUSSION
NWS ALBANY NY
640 AM EDT SAT SEP 19 2015 .SYNOPSIS... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 640 AM EDT...HIGH LEVEL CLOUDS ALREADY STARTING TO THIN OUT AS EXPECTED AND WILL CONTINUE THROUGH THIS MORNING LEAVING MOSTLY SUNNY SKIES FOR MUCH OF THE AREA INTO THE AFTERNOON. ADDITIONAL CLOUDS INCREASE FROM THE WEST ASSOCIATED WITH A COLD FRONT APPROACHING FROM THE GREAT LAKES LATE IN THE DAY. ONE MORE WARM DAY IS EXPECTED...WITH SUNSHINE AND A SOUTHERLY FLOW RESULTING IN HIGH TEMPS IN THE UPPER 70S TO LOWER 80S. MOST OF THE AREA SHOULD REMAIN DRY THROUGH THE DAYLIGHT HOURS. HOWEVER...CHANCES FOR SHOWERS WILL START TO INCREASE FOR THE WESTERN ADIRONDACKS/MOHAWK VALLEY LATE IN THE DAY AS THE COLD FRONT MOVES INTO WESTERN NY. BASED ON TIMING FROM HRRR AND LOCAL HI-RES WRF...WILL ONLY MENTION 20-30 POPS FOR HERKIMER/HAMILTON COUNTIES THROUGH 6 PM TODAY. THE BULK OF THE SHOWERS WILL ARRIVE AFTER DARK. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SHOWERS WILL BE MOVING INTO WESTERN PORTIONS OF THE AREA EARLY THIS EVENING...PRECEDING A COLD FRONT PUSHING EASTWARD ACROSS NY STATE. MODELS INDICATING A NARROW RIBBON OF WEAK INSTABILITY JUST AHEAD OF THE FRONT...SO WILL MENTION ISOLATED THUNDER ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. SOME BRIEF GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE LINE OF SHOWERS/STORMS FOR THIS AREA...BUT THERE WILL NOT BE ENOUGH INSTABILITY TO SUSTAIN TALL ENOUGH UPDRAFTS TO PRODUCE STRONGER WINDS. MODELS INDICATE THE LINE OF SHOWERS WILL BE WEAKENING SOMEWHAT AS THEY MOVE EAST DURING THE LATE EVENING AND OVERNIGHT HOURS. SO WILL MAINLY MENTION CHANCE POPS FOR MUCH OF THE AREA WITH LIGHT QPF AMOUNTS. THE COLD FRONT AND ANY ASSOCIATED SHOWERS SHOULD CLEAR THE ENTIRE AREA BY DAYBREAK SUNDAY. WINDS WILL BECOME NORTHERLY BEHIND THE FRONT AND WILL BE NOTICEABLE ALONG WITH COOLER TEMPERATURES. HIGHS ARE ONLY EXPECTED TO BE IN THE 60S TO NEAR 70...WHICH IS NEAR NORMAL BUT MUCH COOLER THAN RECENT DAYS. CLOUDS WILL DECREASE THROUGHOUT THE DAY AS HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE AREA. HIGH PRESSURE WILL SETTLE IN OVER THE REGION SUNDAY NIGHT INTO MONDAY MORNING...RESULTING IN CLEAR SKIES AND LIGHT WINDS. THESE CONDITIONS WILL ALLOW FOR THE COOLEST OVERNIGHT TEMPERATURES WE HAVE SEEN IN THREE MONTHS. LOWS ARE FORECAST TO BE IN THE UPPER 30S TO MID 40S...WITH PATCHY FROST POSSIBLE FOR SOME AREAS NORTH AND EAST OF ALBANY. THE LAST DAY ALBANY OFFICIALLY HAD A TEMPERATURE IN THE 40S WAS BACK ON JUNE 20TH...WHICH WAS 49 DEGREES THAT MORNING. TRANQUIL WEATHER WILL PERSIST MONDAY AND MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN CONTROL. TEMPERATURES LOOK TO BE CLOSE TO NORMAL. MONDAY NIGHT WILL LIKELY NOT BE AS COLD AS THE PREVIOUS NIGHT DUE TO SOME POSSIBLE ADDED CLOUD COVER AND A SLIGHT EASTERLY BREEZE...AS THE CENTER OF THE HIGH PRESSURE SYSTEM RETREATS TOWARDS THE CANADIAN MARITIMES. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE LONG TERM PERIOD STARTS OUT DRY AND SEASONABLE AS A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM THE OHIO VALLEY NORTHEASTWARD INTO THE NORTHEASTERN US. A WEAK COLD FRONT IS EXPECTED TO DROP SOUTHEAST FROM SOUTHERN CANADA THROUGH THE NORTHEAST ON WEDNESDAY AND STALL ACROSS THE MIDDLE ATLANTIC REGION ON THURSDAY. AT THIS TIME EXPECT THE FRONTAL PASSAGE WILL BE DRY WITH MODEL GUIDANCE INDICATING LITTLE IF ANY MOISTURE WITH THE FRONTAL BOUNDARY. FRIDAY AT THIS POINT IS A DIFFICULT FORECAST AS THE MODELS DIVERGE ON WHETHER OR NOT MOISTURE FROM THE SOUTH LIFTS NORTH WITH THE FRONTAL BOUNDARY STALLED JUST TO OUR SOUTH. AT THIS TIME THE GFS LIFTS MOISTURE NORTHWARD ACROSS OUR REGION ON FRIDAY WHILE THE ECMWF IS DRY WITH HIGH PRESSURE REMAINING IN CONTROL OF OUR WEATHER. FOR NOW WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR FRIDAY. TEMPERATURES FOR THE LONG TERM PERIOD WILL BE SEASONABLE TO SLIGHTLY BELOW NORMAL. EXPECT HIGHS TUESDAY TO BE IN THE MID 60S TO MID 70S WITH HIGHS ON WEDNESDAY AND THURSDAY IN THE UPPER 60S TO MID 70S AND HIGHS ON FRIDAY IN THE 60S TO AROUND 70 ALTHOUGH IT COULD BE COOLER IF THE GFS IS CORRECT. LOWS WILL BE IN THE 40S TO LOWER 50S TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... FOR TODAY EXPECTING SOME HIGH CLOUDS TO STREAM IN AND EVENTUALLY MID CLOUDS THIS AFTERNOON TO MOVE IN AHEAD AN APPROACHING COLD FRONT. THIS BOUNDARY WILL USHER A MUCH COOLER AND MORE SEASONABLE AIR MASS INTO THE REGION WITH ITS PASSAGE TONIGHT. HAVE INCLUDED -SHRA FOR KGFL AFTER 03Z AND VCSH FOR KALB...KPSF AND KPOU BTWN 03Z AND 05Z AS SHOWERS WILL BE DIMINISHING IN COVERAGE AS THEY MOVE SOUTH AND EAST. CIGS WILL ALSO LOWER TO OVC035-050 BTWN 03Z AND 05Z. SKIES WILL THEN BECOME SCT035-045 LATE TONIGHT IN THE WAKE OF THE COLD FRONT. CALM WINDS WILL BECOME SOUTHERLY TODAY AS THE FLOW WILL PICK UP DURING THE DAY TO 8 TO 12 KNOTS WITH SOME 15-22 KTS EXPECTED AT KGFL...KPSF AND ESPECIALLY KALB DURING THE AFTERNOON. WINDS WILL REMAIN BTWN 08-12 KTS THIS EVENING BEFORE SHIFTING TO THE WEST- NORTHWEST WITH THE FRONTAL PASSAGE LATE TONIGHT. OUTLOOK... SUN-WED: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. MINIMUM RELATIVE HUMIDITY VALUES TODAY WILL BE AROUND 45 TO 50 PERCENT...INCREASING TO MAXIMUM VALUES OF 85 TO 100 PERCENT TONIGHT. MIN RH VALUES ON SUNDAY ARE FORECAST TO BE BETWEEN 35 AND 45 PERCENT. WINDS TODAY WILL BE SOUTHERLY AROUND 10 TO 15 MPH...BECOMING NORTHWEST AT 5 TO 15 MPH TONIGHT AS A COLD FRONT PASSES THROUGH. WINDS ON SUNDAY WILL BECOME NORTHERLY AROUND 5 TO 15 MPH. && .HYDROLOGY... NO HYDROLOGIC CONCERNS THROUGH THE NEXT FIVE DAYS. DRY CONDITIONS WILL PERSIST THROUGH MUCH OF TODAY. A COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST TONIGHT WITH MAINLY SCATTERED SHOWERS EXPECTED. SHOWERS WILL BE MORE NUMEROUS ACROSS THE WESTERN ADIRONDACKS WHERE ONE QUARTER TO ONE THIRD OF AN INCH OF RAINFALL IS POSSIBLE. ELSEWHERE GENERALLY A TENTH OF AN INCH OR LESS IS EXPECTED. THE RAINFALL WILL HAVE LITTLE...IF ANY IMPACT ON AREA RIVERS. DRY CONDITIONS RETURN FOR SUNDAY AND WILL LIKELY LAST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH ANOTHER AREA OF HIGH PRESSURE BUILDING IN. RIVER FLOWS WILL CONTINUE TO RECEDE INTO NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...11 AVIATION...11 FIRE WEATHER...JPV HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
620 AM EDT SAT SEP 19 2015 .SYNOPSIS... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 412 AM EDT...SOME HIGH LEVEL CLOUDS HAVE MOVED INTO THE AREA EARLY THIS MORNING...WHICH ARE DEBRIS CLOUDS FROM SHOWERS THAT FELL APART TO THE WEST OF OUR REGION YESTERDAY. THE CLOUDS HAVE NOT PREVENTED TEMPERATURES FROM FALLING THOUGH...WITH 50S ACROSS MUCH OF THE AREA. THE ONLY EXCEPTION IS IN THE CAPITAL DISTRICT WHERE A SOUTHERLY BREEZE HAS KEPT TEMPS IN THE LOWER TO MID 60S. PATCHY FOG IS ALSO OCCURRING...BUT THE COVERAGE APPEARS TO BE LESS THAN YESTERDAY MORNING. CLOUDS SHOULD TEND TO THIN OUT SOMEWHAT LATER THIS MORNING...BEFORE ADDITIONAL CLOUDS INCREASE FROM THE WEST ASSOCIATED WITH A COLD FRONT APPROACHING FROM THE GREAT LAKES. ONE MORE WARM DAY IS EXPECTED...WITH SUNSHINE AND A SOUTHERLY FLOW RESULTING IN HIGH TEMPS IN THE UPPER 70S TO LOWER 80S. MOST OF THE AREA SHOULD REMAIN DRY THROUGH THE DAYLIGHT HOURS. HOWEVER...CHANCES FOR SHOWERS WILL START TO INCREASE FOR THE WESTERN ADIRONDACKS/MOHAWK VALLEY LATE IN THE DAY AS THE COLD FRONT MOVES INTO WESTERN NY. BASED ON TIMING FROM HRRR AND LOCAL HI-RES WRF...WILL ONLY MENTION 20-30 POPS FOR HERKIMER/HAMILTON COUNTIES THROUGH 6 PM TODAY. THE BULK OF THE SHOWERS WILL ARRIVE TONIGHT. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SHOWERS WILL BE MOVING INTO WESTERN PORTIONS OF THE AREA EARLY THIS EVENING...PRECEDING A COLD FRONT PUSHING EASTWARD ACROSS NY STATE. MODELS INDICATING A NARROW RIBBON OF WEAK INSTABILITY JUST AHEAD OF THE FRONT...SO WILL MENTION ISOLATED THUNDER ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. SOME BRIEF GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE LINE OF SHOWERS/STORMS FOR THIS AREA...BUT THERE WILL NOT BE ENOUGH INSTABILITY TO SUSTAIN TALL ENOUGH UPDRAFTS TO PRODUCE STRONGER WINDS. MODELS INDICATE THE LINE OF SHOWERS WILL BE WEAKENING SOMEWHAT AS THEY MOVE EAST DURING THE LATE EVENING AND OVERNIGHT HOURS. SO WILL MAINLY MENTION CHANCE POPS FOR MUCH OF THE AREA WITH LIGHT QPF AMOUNTS. THE COLD FRONT AND ANY ASSOCIATED SHOWERS SHOULD CLEAR THE ENTIRE AREA BY DAYBREAK SUNDAY. WINDS WILL BECOME NORTHERLY BEHIND THE FRONT AND WILL BE NOTICEABLE ALONG WITH COOLER TEMPERATURES. HIGHS ARE ONLY EXPECTED TO BE IN THE 60S TO NEAR 70...WHICH IS NEAR NORMAL BUT MUCH COOLER THAN RECENT DAYS. CLOUDS WILL DECREASE THROUGHOUT THE DAY AS HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE AREA. HIGH PRESSURE WILL SETTLE IN OVER THE REGION SUNDAY NIGHT INTO MONDAY MORNING...RESULTING IN CLEAR SKIES AND LIGHT WINDS. THESE CONDITIONS WILL ALLOW FOR THE COOLEST OVERNIGHT TEMPERATURES WE HAVE SEEN IN THREE MONTHS. LOWS ARE FORECAST TO BE IN THE UPPER 30S TO MID 40S...WITH PATCHY FROST POSSIBLE FOR SOME AREAS NORTH AND EAST OF ALBANY. THE LAST DAY ALBANY OFFICIALLY HAD A TEMPERATURE IN THE 40S WAS BACK ON JUNE 20TH...WHICH WAS 49 DEGREES THAT MORNING. TRANQUIL WEATHER WILL PERSIST MONDAY AND MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN CONTROL. TEMPERATURES LOOK TO BE CLOSE TO NORMAL. MONDAY NIGHT WILL LIKELY NOT BE AS COLD AS THE PREVIOUS NIGHT DUE TO SOME POSSIBLE ADDED CLOUD COVER AND A SLIGHT EASTERLY BREEZE...AS THE CENTER OF THE HIGH PRESSURE SYSTEM RETREATS TOWARDS THE CANADIAN MARITIMES. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE LONG TERM PERIOD STARTS OUT DRY AND SEASONABLE AS A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM THE OHIO VALLEY NORTHEASTWARD INTO THE NORTHEASTERN US. A WEAK COLD FRONT IS EXPECTED TO DROP SOUTHEAST FROM SOUTHERN CANADA THROUGH THE NORTHEAST ON WEDNESDAY AND STALL ACROSS THE MIDDLE ATLANTIC REGION ON THURSDAY. AT THIS TIME EXPECT THE FRONTAL PASSAGE WILL BE DRY WITH MODEL GUIDANCE INDICATING LITTLE IF ANY MOISTURE WITH THE FRONTAL BOUNDARY. FRIDAY AT THIS POINT IS A DIFFICULT FORECAST AS THE MODELS DIVERGE ON WHETHER OR NOT MOISTURE FROM THE SOUTH LIFTS NORTH WITH THE FRONTAL BOUNDARY STALLED JUST TO OUR SOUTH. AT THIS TIME THE GFS LIFTS MOISTURE NORTHWARD ACROSS OUR REGION ON FRIDAY WHILE THE ECMWF IS DRY WITH HIGH PRESSURE REMAINING IN CONTROL OF OUR WEATHER. FOR NOW WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR FRIDAY. TEMPERATURES FOR THE LONG TERM PERIOD WILL BE SEASONABLE TO SLIGHTLY BELOW NORMAL. EXPECT HIGHS TUESDAY TO BE IN THE MID 60S TO MID 70S WITH HIGHS ON WEDNESDAY AND THURSDAY IN THE UPPER 60S TO MID 70S AND HIGHS ON FRIDAY IN THE 60S TO AROUND 70 ALTHOUGH IT COULD BE COOLER IF THE GFS IS CORRECT. LOWS WILL BE IN THE 40S TO LOWER 50S TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... FOR TODAY EXPECTING SOME HIGH CLOUDS TO STREAM IN AND EVENTUALLY MID CLOUDS THIS AFTERNOON TO MOVE IN AHEAD AN APPROACHING COLD FRONT. THIS BOUNDARY WILL USHER A MUCH COOLER AND MORE SEASONABLE AIR MASS INTO THE REGION WITH ITS PASSAGE TONIGHT. HAVE INCLUDED -SHRA FOR KGFL AFTER 03Z AND VCSH FOR KALB...KPSF AND KPOU BTWN 03Z AND 05Z AS SHOWERS WILL BE DIMINISHING IN COVERAGE AS THEY MOVE SOUTH AND EAST. CIGS WILL ALSO LOWER TO OVC035-050 BTWN 03Z AND 05Z. SKIES WILL THEN BECOME SCT035-045 LATE TONIGHT IN THE WAKE OF THE COLD FRONT. CALM WINDS WILL BECOME SOUTHERLY TODAY AS THE FLOW WILL PICK UP DURING THE DAY TO 8 TO 12 KNOTS WITH SOME 15-22 KTS EXPECTED AT KGFL...KPSF AND ESPECIALLY KALB DURING THE AFTERNOON. WINDS WILL REMAIN BTWN 08-12 KTS THIS EVENING BEFORE SHIFTING TO THE WEST- NORTHWEST WITH THE FRONTAL PASSAGE LATE TONIGHT. OUTLOOK... SUN-WED: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. MINIMUM RELATIVE HUMIDITY VALUES TODAY WILL BE AROUND 45 TO 50 PERCENT...INCREASING TO MAXIMUM VALUES OF 85 TO 100 PERCENT TONIGHT. MIN RH VALUES ON SUNDAY ARE FORECAST TO BE BETWEEN 35 AND 45 PERCENT. WINDS TODAY WILL BE SOUTHERLY AROUND 10 TO 15 MPH...BECOMING NORTHWEST AT 5 TO 15 MPH TONIGHT AS A COLD FRONT PASSES THROUGH. WINDS ON SUNDAY WILL BECOME NORTHERLY AROUND 5 TO 15 MPH. && .HYDROLOGY... NO HYDROLOGIC CONCERNS THROUGH THE NEXT FIVE DAYS. DRY CONDITIONS WILL PERSIST THROUGH MUCH OF TODAY. A COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST TONIGHT WITH MAINLY SCATTERED SHOWERS EXPECTED. SHOWERS WILL BE MORE NUMEROUS ACROSS THE WESTERN ADIRONDACKS WHERE ONE QUARTER TO ONE THIRD OF AN INCH OF RAINFALL IS POSSIBLE. ELSEWHERE GENERALLY A TENTH OF AN INCH OR LESS IS EXPECTED. THE RAINFALL WILL HAVE LITTLE...IF ANY IMPACT ON AREA RIVERS. DRY CONDITIONS RETURN FOR SUNDAY AND WILL LIKELY LAST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH ANOTHER AREA OF HIGH PRESSURE BUILDING IN. RIVER FLOWS WILL CONTINUE TO RECEDE INTO NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...JPV SHORT TERM...JPV LONG TERM...11 AVIATION...11 FIRE WEATHER...JPV HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS MIAMI FL
1123 AM EDT SAT SEP 19 2015 .UPDATE... UPDATED POPS ONCE AGAIN, LEAVING ONLY THE COASTAL AREAS UNDER A CHANCE, WITH THE OTHER AREAS DROPPED TO A SLIGHT CHANCE. THIS IS SUPPORTED BY BOTH THE LACK OF ACTIVITY OVER THE INTERIOR, THE FAIRLY CLEAR SKIES FOR THE LATE MORNING, AND THE HRRR, WHICH ONLY DEVELOPS A SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON INTO THE EVENING HOURS. && .PREV DISCUSSION... /ISSUED 1037 AM EDT SAT SEP 19 2015/ UPDATE... MUCH DIFFERENT MORNING THAN YESTERDAY MORNING. VERY LITTLE ACTIVITY ON RADAR. WITH ALL THE ACTIVITY OVER THE COASTAL WATERS AT THIS TIME. THE HRRR KEEPS THE WEATHER FAIRLY QUIET ACROSS THE CWA THROUGH THE AFTERNOON HOURS, WITH SOME ISOLATED TO SCATTERED CONVECTION THIS AFTERNOON. ONLY REAL CHANGES ARE TO SKY COVER AND TO ADJUST WIND TO INCLUDE MORE CURRENT MODEL RUNS, ALSO REDUCE POPS IN THE WESTERN PORTION OF THE CWA, GIVEN THE CURRENT RUN OF THE HRRR. OTHERWISE, THE FORECAST IS PROGRESSING FAIRLY WELL. PREV DISCUSSION... /ISSUED 808 AM EDT SAT SEP 19 2015/ AVIATION... MAINLY VFR CONDITIONS ACROSS SOUTH FLORIDA TODAY. THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS ALONG THE EAST COAST OF SOUTH FLORIDA, MAINLY THIS AFTERNOON. HOWEVER, THE COVERAGE SHOULD BE LESS THAN YESTERDAY. GIVEN THIS, ONLY VCTS IN THE TAFS TODAY. EXPECT WIND TO CONTINUE FROM THE SOUTHWEST THROUGH THE DAY, GOING LIGHT AND VARIABLE THIS EVENING. PREV DISCUSSION... /ISSUED 340 AM EDT SAT SEP 19 2015/ DISCUSSION... TODAY-TONIGHT...SURFACE LOW CONTINUES TO SLOWLY DEEPEN OFF THE FL/GA COAST THIS MORNING WHILE RADAR AND SATELLITE SHOW THE WEAKER GULF LOW HAS BEEN ABSORBED INTO THE LARGER CIRCULATION. THE MID- UPPER LEVEL TROUGH THAT`S BEEN OVER THE STATE WILL ALSO BEGIN LIFTING OUT TO THE NORTHEAST...THOUGH THE AXIS WILL GET SHIFTED FURTHER SOUTH INTO S FLORIDA AS A RESULTING BRINGING COOLER MID LEVEL TEMPS. WAVER VAPOR SATELLITE IS SHOWING THE DEEPER MOISTURE BEING LIFTED OUT WITH SOME MID LEVEL DRYING ACROSS NORTH AND CENTRAL FLORIDA THAT MODELS BRING INTO SOUTH FLORIDA INTO THE AFTERNOON. STEERING FLOW HAS PICKED UP OUT OF THE SW WITH THE CURRENT SHOWERS AND STORMS OVER THE WATERS THIS MORNING MOVING AT AROUND 20KTS. LITTLE CHANGE IN THIS SPEED THROUGH THE DAY SO WE WILL SEE FAIRLY QUICK MOVING SHOWERS AND STORMS INTO THE AFTERNOON. ACTIVITY WILL ONCE AGAIN FAVOR EAST COAST...WITH MODELS FOCUSING MORE TOWARDS BROWARD /MIAMI-DADE WHERE TRAILING SURFACE TROUGH LIES. GIVEN STORM MOTION...DON`T EXPECT HEAVY RAIN TO BE AS SIGNIFICANT A CONCERN BUT WILL HAVE TO WATCH FOR SOME TRAINING IN SPOTS GIVEN THE ALREADY SATURATED GROUND. OVERALL COVERAGE IS ALSO EXPECTED TO BE LOWER THAN THE PAST FEW DAYS. ACTIVITY SHOULD BE FAIRLY QUICK TO PUSH OFFSHORE THIS EVENING WITH ACTIVITY JUST OVER THE WATERS OVERNIGHT. SUNDAY...MID-UPPER LEVEL TROUGH CONTINUES TO WEAKEN AND LIFT OFF TO THE NORTHEAST INTO SUNDAY...TAKING WITH IT THE DEEPENING SURFACE LOW OFFSHORE THE CAROLINA COAST. TRAILING EDGE OF THE TROUGH LINGERS OVER S FLORIDA WITH CONTINUING DEEP AND BRISK WEST-SOUTHWESTERLY FLOW. DRIER AIR BEGINS TO WORK FURTHER DOWN THE PENINSULA IN THE CYCLONIC FLOW AROUND THE BACK SIDE OF THE DISTANT LOW...PUSHING THE DEEPER TROPICAL MOISTURE SOUTH OF THE STATE. RAIN CHANCES ACROSS THE REGION DIMINISH CONSIDERABLY...STILL FAVORING THE EAST COAST AND FAR SOUTH PENINSULA IN FAST MOVING SHOWERS AND A FEW STORMS. LONG TERM (MONDAY-FRIDAY)...SURFACE LOW CONTINUES TO LIFT FURTHER OFF TO THE NORTHEAST EARLY NEXT WEEK LEAVING A WEAK PRESSURE GRADIENT IN PLACE ACROSS THE STATE WITH DAILY SEA BREEZES BECOMING THE MAIN DRIVER OF AFTERNOON CONVECTION. MODELS REMAIN CONSISTENT IN SHOWING FAIRLY DECENT MID LEVEL DRY AIR WRAPPING AROUND THE BACK OF THE LOW INTO THE STATE MON-WED WHICH LOOKS TO KEEP RAIN CHANCES A LITTLE BELOW NORMAL AT 20-30 PERCENT...INCREASING TO 30-40 PERCENT ON WED WITH SOME MOISTURE ADVECTION AHEAD OF THE NEXT TROUGH. WEST- SOUTHWESTERLY STEERING COMPONENT REMAINS IN PLACE ON MONDAY...KEEPING THE BEST (THOUGH MUCH LOWER) RAIN CHANCES TOWARDS THE EAST COAST...BEFORE BECOMING LIGHT AND VARIABLE INTO MID WEEK WITH MORE ACTIVITY OVER THE INTERIOR. MID TO LATE WEEK MODELS SHOW THE NEXT TROUGH MOVING INTO THE EASTERN US CUTTING OFF OVER THE SOUTHEAST...A LITTLE FARTHER NORTH THAN YESTERDAY`S RUNS. 19/00Z GFS LIFTS THE LOW OUT INTO THE MID-ATLANTIC FAIRLY QUICKLY WHILE THE ECMWF STILL HAS IT RETROGRADING BACK TO THE GULF. WITH THE GFS`S MORE PROGRESSIVE SOLUTION...FLOW REMAINS MORE SOUTHWEST THAN SOUTH AND DEEP MOISTURE ADVECTION IS NOT QUITE AS PRONOUNCED ACROSS S FL. NONETHELESS...WE ARE LOOKING AT A RETURN TO A STORMY PATTERN TOWARDS THE END OF NEXT WEEK. MARINE...MODERATE SW WINDS OVER THE ATLANTIC TODAY 10-15KTS AS SURFACE LOW OFF THE GA/FL COAST DEEPENS AND SLOWLY MOVES OFF TO THE NE. WEST-NW WINDS 10KTS OVER THE GULF WATERS. PRESSURE GRADIENT COLLAPSES ON SUN RESULTING IN LIGHT WEST-NW WINDS 5-10KTS...VEERING N-NE MON AND TUES THEN EAST ON WED. SEAS GENERALLY 2FT OR LESS...WITH UP TO 3FT IN THE GULF STREAM THIS AFTERNOON AND 4FT TUES- THURS WITH SOME INCOMING SWELL AND NORTH FETCH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 90 75 91 77 / 30 20 30 20 FORT LAUDERDALE 91 77 90 78 / 30 20 40 30 MIAMI 91 77 91 78 / 30 20 40 30 NAPLES 89 76 90 75 / 20 10 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....88/ALM
AREA FORECAST DISCUSSION
NWS MIAMI FL
1037 AM EDT SAT SEP 19 2015 .UPDATE... MUCH DIFFERENT MORNING THAN YESTERDAY MORNING. VERY LITTLE ACTIVITY ON RADAR. WITH ALL THE ACTIVITY OVER THE COASTAL WATERS AT THIS TIME. THE HRRR KEEPS THE WEATHER FAIRLY QUIET ACROSS THE CWA THROUGH THE AFTERNOON HOURS, WITH SOME ISOLATED TO SCATTERED CONVECTION THIS AFTERNOON. ONLY REAL CHANGES ARE TO SKY COVER AND TO ADJUST WIND TO INCLUDE MORE CURRENT MODEL RUNS, ALSO REDUCE POPS IN THE WESTERN PORTION OF THE CWA, GIVEN THE HRRRS CURRENT RUN. OTHERWISE, THE FORECAST IS PROGRESSING FAIRLY WELL. && .PREV DISCUSSION... /ISSUED 808 AM EDT SAT SEP 19 2015/ AVIATION... MAINLY VFR CONDITIONS ACROSS SOUTH FLORIDA TODAY. THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS ALONG THE EAST COAST OF SOUTH FLORIDA, MAINLY THIS AFTERNOON. HOWEVER, THE COVERAGE SHOULD BE LESS THAN YESTERDAY. GIVEN THIS, ONLY VCTS IN THE TAFS TODAY. EXPECT WIND TO CONTINUE FROM THE SOUTHWEST THROUGH THE DAY, GOING LIGHT AND VARIABLE THIS EVENING. PREV DISCUSSION... /ISSUED 340 AM EDT SAT SEP 19 2015/ DISCUSSION... TODAY-TONIGHT...SURFACE LOW CONTINUES TO SLOWLY DEEPEN OFF THE FL/GA COAST THIS MORNING WHILE RADAR AND SATELLITE SHOW THE WEAKER GULF LOW HAS BEEN ABSORBED INTO THE LARGER CIRCULATION. THE MID- UPPER LEVEL TROUGH THAT`S BEEN OVER THE STATE WILL ALSO BEGIN LIFTING OUT TO THE NORTHEAST...THOUGH THE AXIS WILL GET SHIFTED FURTHER SOUTH INTO S FLORIDA AS A RESULTING BRINGING COOLER MID LEVEL TEMPS. WAVER VAPOR SATELLITE IS SHOWING THE DEEPER MOISTURE BEING LIFTED OUT WITH SOME MID LEVEL DRYING ACROSS NORTH AND CENTRAL FLORIDA THAT MODELS BRING INTO SOUTH FLORIDA INTO THE AFTERNOON. STEERING FLOW HAS PICKED UP OUT OF THE SW WITH THE CURRENT SHOWERS AND STORMS OVER THE WATERS THIS MORNING MOVING AT AROUND 20KTS. LITTLE CHANGE IN THIS SPEED THROUGH THE DAY SO WE WILL SEE FAIRLY QUICK MOVING SHOWERS AND STORMS INTO THE AFTERNOON. ACTIVITY WILL ONCE AGAIN FAVOR EAST COAST...WITH MODELS FOCUSING MORE TOWARDS BROWARD /MIAMI-DADE WHERE TRAILING SURFACE TROUGH LIES. GIVEN STORM MOTION...DON`T EXPECT HEAVY RAIN TO BE AS SIGNIFICANT A CONCERN BUT WILL HAVE TO WATCH FOR SOME TRAINING IN SPOTS GIVEN THE ALREADY SATURATED GROUND. OVERALL COVERAGE IS ALSO EXPECTED TO BE LOWER THAN THE PAST FEW DAYS. ACTIVITY SHOULD BE FAIRLY QUICK TO PUSH OFFSHORE THIS EVENING WITH ACTIVITY JUST OVER THE WATERS OVERNIGHT. SUNDAY...MID-UPPER LEVEL TROUGH CONTINUES TO WEAKEN AND LIFT OFF TO THE NORTHEAST INTO SUNDAY...TAKING WITH IT THE DEEPENING SURFACE LOW OFFSHORE THE CAROLINA COAST. TRAILING EDGE OF THE TROUGH LINGERS OVER S FLORIDA WITH CONTINUING DEEP AND BRISK WEST-SOUTHWESTERLY FLOW. DRIER AIR BEGINS TO WORK FURTHER DOWN THE PENINSULA IN THE CYCLONIC FLOW AROUND THE BACK SIDE OF THE DISTANT LOW...PUSHING THE DEEPER TROPICAL MOISTURE SOUTH OF THE STATE. RAIN CHANCES ACROSS THE REGION DIMINISH CONSIDERABLY...STILL FAVORING THE EAST COAST AND FAR SOUTH PENINSULA IN FAST MOVING SHOWERS AND A FEW STORMS. LONG TERM (MONDAY-FRIDAY)...SURFACE LOW CONTINUES TO LIFT FURTHER OFF TO THE NORTHEAST EARLY NEXT WEEK LEAVING A WEAK PRESSURE GRADIENT IN PLACE ACROSS THE STATE WITH DAILY SEA BREEZES BECOMING THE MAIN DRIVER OF AFTERNOON CONVECTION. MODELS REMAIN CONSISTENT IN SHOWING FAIRLY DECENT MID LEVEL DRY AIR WRAPPING AROUND THE BACK OF THE LOW INTO THE STATE MON-WED WHICH LOOKS TO KEEP RAIN CHANCES A LITTLE BELOW NORMAL AT 20-30 PERCENT...INCREASING TO 30-40 PERCENT ON WED WITH SOME MOISTURE ADVECTION AHEAD OF THE NEXT TROUGH. WEST- SOUTHWESTERLY STEERING COMPONENT REMAINS IN PLACE ON MONDAY...KEEPING THE BEST (THOUGH MUCH LOWER) RAIN CHANCES TOWARDS THE EAST COAST...BEFORE BECOMING LIGHT AND VARIABLE INTO MID WEEK WITH MORE ACTIVITY OVER THE INTERIOR. MID TO LATE WEEK MODELS SHOW THE NEXT TROUGH MOVING INTO THE EASTERN US CUTTING OFF OVER THE SOUTHEAST...A LITTLE FARTHER NORTH THAN YESTERDAY`S RUNS. 19/00Z GFS LIFTS THE LOW OUT INTO THE MID-ATLANTIC FAIRLY QUICKLY WHILE THE ECMWF STILL HAS IT RETROGRADING BACK TO THE GULF. WITH THE GFS`S MORE PROGRESSIVE SOLUTION...FLOW REMAINS MORE SOUTHWEST THAN SOUTH AND DEEP MOISTURE ADVECTION IS NOT QUITE AS PRONOUNCED ACROSS S FL. NONETHELESS...WE ARE LOOKING AT A RETURN TO A STORMY PATTERN TOWARDS THE END OF NEXT WEEK. MARINE...MODERATE SW WINDS OVER THE ATLANTIC TODAY 10-15KTS AS SURFACE LOW OFF THE GA/FL COAST DEEPENS AND SLOWLY MOVES OFF TO THE NE. WEST-NW WINDS 10KTS OVER THE GULF WATERS. PRESSURE GRADIENT COLLAPSES ON SUN RESULTING IN LIGHT WEST-NW WINDS 5-10KTS...VEERING N-NE MON AND TUES THEN EAST ON WED. SEAS GENERALLY 2FT OR LESS...WITH UP TO 3FT IN THE GULF STREAM THIS AFTERNOON AND 4FT TUES- THURS WITH SOME INCOMING SWELL AND NORTH FETCH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 90 75 91 77 / 30 20 30 20 FORT LAUDERDALE 91 77 90 78 / 40 20 40 30 MIAMI 91 77 91 78 / 30 20 40 30 NAPLES 89 76 90 75 / 20 10 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....88/ALM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1019 AM EDT SAT SEP 19 2015 .DISCUSSION...LOW CLOUDS WHICH IMPACTED NORTHERN COUNTIES NOW BEGINNING TO LIFT...TRANSITIONING TO PARTLY/MOSTLY SUNNY LATE MRONING. UPPER TROUGH REMAINS OVER REGION TODAY...WITH SURFACE TROUGH EXTENDING FROM SURFACE LOW WELL OFFSHORE JACKSONVILLE TO THE TREASURE COAST/LAKE OKEECHOBEE AREA. CYCLONIC FLOW PATTERN WILL AFFECT CWA TODAY TO THE SW OF SURFACE LOW. HRRR AND LOCAL WRF BOTH SUGGEST ONSHORE FLOW WILL INITIATE AREA OF SCATTERED SHOWERS OVER/NEAR VOLUSIA COUNTY...WITH ACTIVITY EXPANDING INTO PRIMARILY SEMINOLE/ORANGE AND NORTHERN BREVARD COUNTIES DURING THE AFTERNOON...WITH ISOLATED STORMS POSSIBLE. EXPECT CONVERGENCE/LIFT ALONG BOUNDARY OVER SOUTHERN COUNTIES TO ALSO PROMPT SOME CONVECTIVE DEVELOPMENT. CURRENT POP DISTRIBUTION AGREES WELL WITH SCENARIO OF HIGHEST POPS (40) NE AND A LITTLE LOWER SOUTH AND INLAND. EXPECT ISOLATED SHOWERS/STORMS TO LINGER INTO EARLY EVENING. MAX TEMPS UPPER 80S COAST AND AROUND 90 INLAND. && .AVIATION...LIFR CIGS AT NORTH/INTERIOR TAF SITES WILL LIFT/DIMINISH BY 15Z. SHOWER/STORM COVERAGE LOW ENOUGH TO OMIT FROM TAFS...BUT BASED ON TRENDS...MAY NEED TO ADD SMALL WINDOW OF SHRA AND MVFR CIGS TO SOME TAF SITES...MAINLY KDAB/KTIX/KSFB. && .MARINE...N WINDS INCREASING TO 15-20 KT OFFSHORE/NORTH THIS AFTERNOON AND 10-15 KT ELSEWHERE...EXCEPT 5-10 KT NEARSHORE/SOUTH. SEAS 3-5 FT...EXCEPT BUILDING TO 4-6 FT OFFSHORE/NORTH THIS AFTERNOON. NO CHANGES TO EARLY MORNING CWF. && .HYDROLOGY... AS A RESULT OF THE RECENT HEAVY RAINS...THE ST. JOHNS RIVER ABOVE LAKE HARNEY /GENF1/ HAS REACHED 6.1FT...WHICH IS 0.4 FEET BELOW ACTION STAGE (6.5FT). THE RIVER IS FORECAST TO REACH THE LOWER THRESHOLD OF ACTION STAGE EARLY SUNDAY...AND REMAIN NEARLY STEADY STATE WELL INTO NEXT WEEK. THE SAINT JOHNS RIVER AT ASTOR /ASTF1/ HAS REACHED 2.25FT...WHICH IS 0.25 FEET BELOW ACTIONS STAGE (2.5FT). THE RIVER WILL REMAIN NEAR ACTION STAGE OVER THE NEXT SEVERAL DAYS DUE TO SLIGHT RISES DOWNSTREAM AND NORTHERLY WINDS SLOWING DRAINAGE UPSTREAM. && .PRELIMINARY POINT TEMPS/POPS... DAB 87 73 89 71 / 40 20 10 10 MCO 89 73 91 72 / 40 20 20 10 MLB 89 73 90 74 / 30 20 20 10 VRB 89 72 88 70 / 30 20 20 10 LEE 88 73 92 73 / 30 20 10 10 SFB 88 73 91 72 / 40 20 10 10 ORL 89 74 92 74 / 40 20 20 10 FPR 90 73 89 70 / 30 20 20 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ SHORT TERM...SPRATT IMPACT WEATHER/DSS...GLITTO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
945 AM MDT SAT SEP 19 2015 .UPDATE... ISSUED AT 938 AM MDT SAT SEP 19 2015 JUST COMPLETED AN UPDATE. MODELS NOT DOING WELL WITH THE STRENGTH POSITION OF THE SURFACE RIDGE OVER THE AREA AND ALSO THE STRATUS DECK OVER THE EASTERN THIRD OF THE AREA. SURFACE IS STRONGER AND FURTHER WEST THAN WHAT OUTPUT IS INDICATING. SO A SHIFTING TO SOUTHERLY WINDS WILL BE SLOWER...ESPECIALLY FOR THE EASTERN HALF. THICK STRATUS STILL OVER THE EAST AND IS SLOWING DOWN TEMPERATURE RISE. NEWER DATA IS HOLDING ONTO THIS A LITTLE LONGER THAN INDICATED. ALSO MID LEVEL WARM AIR ADVECTION OVER THE COLD DOME AND A WEAK SHORTWAVE TROUGH ARE CREATING A DECENT AREA OF MID LEVEL CLOUD COVER. THIS AREA OF CLOUDS SHOULD MOVE TOWARD THE EAST ...OVER THE STRATUS FIELD. MORNING SOUNDINGS ALSO SHOWING A STRONG INVERSION THIS MORNING. SO LOWERED HIGH TEMPERATURES ACROSS MY NEBRASKA AND KANSAS COUNTIES BECAUSE OF THE CLOUD COVER AND A LESS FAVORABLE WIND FIELD. INCREASED THE CLOUD COVER TO MATCH UP WITH REALITY AND KEPT IT AROUND LONGER AS WELL. UPDATED THE WINDS PER THE NAM WHO IS THE CLOSEST TO REALITY AT THIS TIME. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 208 AM MDT SAT SEP 19 2015 AFTER A CHILLY MORNING...PATCHY FOG AND LOW CLOUDS WILL DISSIPATE WITH MOSTLY SUNNY SKIES BY THE AFTERNOON. HIGH TEMPERATURES WILL BE NEAR SEASONAL NORMALS. TONIGHT...SHORTWAVE EMBEDDED IN ZONAL FLOW ACROSS THE NORTHERN CONUS WILL RESULT IN WEAK SYNOPTIC SCALE LIFT. HOWEVER MOISTURE WILL BE LIMITED AND NONE OF THE MESOSCALE MODELS GENERATE PRECIPITATION...SO WILL REMOVE MENTION OF THUNDERSTORMS AND KEEP POPS AT 10 PERCENT. UPPER RIDGE WILL REBUILD OVER THE REGION SUNDAY AND MONDAY WITH DRY CONDITIONS AND TEMPERATURES WARMING BACK INTO THE 80S ON SUNDAY AND NEAR 90 ON MONDAY. RELATIVE HUMIDITY VALUES WILL DROP TO NEAR 15 PERCENT PRIMARILY IN EASTERN COLORADO BOTH DAYS...BUT WIND SPEEDS WILL BE RELATIVELY LIGHT SO DO NOT EXPECT TO REACH RED FLAG CRITERIA. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 208 AM MDT SAT SEP 19 2015 UPPER LEVEL RIDGING IS OVER THE AREA AT THE START OF THE EXTENDED PERIOD WITH A LEE TROUGH DEVELOPED NEAR THE COLORADO/KANSAS BORDER AT THE SURFACE. THIS WILL KEEP THE FORECAST DRY FOR TUESDAY/TUESDAY NIGHT AS SOUTHERLY SURFACE WINDS BRING WARM TEMPERATURES TO THE REGION. SOUTHWEST FLOW ALOFT WILL CARRY TROPICAL MOISTURE ONTO THE SOUTHWESTERN CONUS FROM THE BAJA PENINSULA ON TUESDAY...WHICH WILL CONTINUE NORTHEAST TOWARDS THE HIGH PLAINS. THIS COINCIDES WITH AN UPPER LEVEL LOW PRESSURE SYSTEM COMING ONTO THE SOUTHERN CALIFORNIA COAST BEFORE WEAKENING TO AN OPEN WAVE AS IT APPROACHES THE REGION. MULTIPLE SHORTWAVES DEVELOP WITHIN THIS SOUTHWEST FLOW ALOFT...IMPACTING THE FORECAST AREA WEDNESDAY THROUGH THURSDAY NIGHT. HOWEVER...MODELS DISAGREE ON THE TIMING AND PLACEMENT OF THESE DISTURBANCES...SO THIS WILL HAVE TO BE MONITORED. KEPT SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS DURING THE WEDNESDAY TO THURSDAY NIGHT TIME FRAME. UPPER LEVEL RIDGING APPEARS TO REBUILD ON FRIDAY...BRINGING DRY CONDITIONS BACK TO THE FORECAST. A VERY GRADUAL COOLING TREND IS EXPECTED FOR THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW 90S ON TUESDAY DECREASING THROUGH THE WORK WEEK TO THE LOW 80S ON FRIDAY. A SIMILAR TREND WILL BE SEEN WITH LOW TEMPERATURES WHICH WILL RANGE FROM THE 50S TO MID 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 519 AM MDT SAT SEP 19 2015 LOW CLOUDS WILL IMPACT KMCK WITH IFR CEILINGS THROUGH LATE MORNING BEFORE CLEARING. UNCERTAIN IF THE LOW CLOUDS WILL MAKE IT AS FAR AS KGLD...BUT WILL CONTINUE TO MONITOR AS SATELLITE SHOWS THEM SPREADING QUICKLY WEST. LATEST RUN OF THE HRRR HAS THEM REACHING TO ABOUT COLBY BEFORE DISSIPATING AFTER 15Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...BULLER SHORT TERM...024 LONG TERM...JBH AVIATION...024
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
902 AM CDT SAT SEP 19 2015 ...UPDATE TO SYNOPSIS... .SYNOPSIS... ISSUED AT 900 AM CDT SAT SEP 19 2015 WV Imagery and 12Z upper air analysis indicate a general westerly flow aloft prevailing across the Western High Plains. Meanwhile, a weak upper level shortwave trough is moving east- southeast across eastern Montana and northern Wyoming. Near the surface, a broad area of high pressure is shifting eastward across Nebraska and Kansas. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 111 AM CDT SAT SEP 19 2015 The main challenge in the short term will be low stratus potential up in the northeast zones (particularly around Hays) and if it will impact temperatures at all. A secondary push of cooler air was making its way south into southwest Kansas with a slight bump in winds from the north. On the 11-3.9u imagery during the overnight hours, we were watching an area of stratus advance south- southwestward toward north central KS. The HRRR suggests that this will reach as far southwest as a Dighton to Dodge City line by 14z. This may be a bit ambitious, but there is certainly some merit to this prog as there is some better low level moisture across central/south central Nebraska that wrapped around the low...which will likely continue to advect southwestward through the early morning hours. We will bump up the clouds in the Sky grids to reflect this latest thinking, especially northeast of the Dighton to Dodge City line. Any low stratus should erode by late morning given how shallow it will be. Temperatures today, with the fresh Canadian airmass in place, will only top out in the lower to mid 70s. Will go with slightly cooler temps in the north where low morning clouds will likely delay the diurnal warmup. Advancing to tonight, we will see low level winds turn back around to the south in response to another loosely organized Pacific system moving into the Northern Rockies. Some marginal moisture will return via the "scenic route" (Eastern New Mexico/western TX-OK Panhandles), and increased deformation/convergence in the 700-800mb layer will promote some elevated showers and isolated thunderstorms after 06z Sunday. We will maintain the 20-30 POPs across mainly the western third of the forecast area late tonight, with low Chance POPs between the Arkansas River and the OK border in the 12-18z Sunday time frame. .LONG TERM...(Sunday THROUGH Friday) ISSUED AT 352 AM CDT SAT SEP 19 2015 Our region of the world will once again see a warming trend going into next week as the primary polar jet shifts back to the north and mid level heights rise across the Southern and Central Rockies/adjacent High Plains. During the slow transition back into above-average temperatures, we will see low chances for precipitation, particularly early Sunday as one last shortwave trough ripples through the longwave trough. Highs Sunday will be tricky, and we feel that portions of south central Kansas, especially, will stay stuck in the 60s to lower 70s with elevated convection and stratus clouds lingering through at least the middle part of the day. The lee trough comes back strong by Monday and will be a quasi- steady feature through at least Wednesday. Afternoon temperatures will gradually increase each day with highs in the lower 90s in some locations. The global spectral models suggest a subtropical shortwave trough ejecting from the Baja California region into Rockies which will bring some mid level moisture across into the High Plains. We will have some Slight Chance to Chance POPs in the grids Wednesday Night through Thursday Night, but at this point, it does not look like a real good opportunity for widespread beneficial rainfall across our region given the degree of downslope momentum in the middle troposphere and the general weak nature of the subtropical system to begin with. Beyond mid-week, it certainly looks like we will continue the theme of above average temperatures across the Rockies and adjacent High Plains in the final days of September with both the GFS and the ECMWF showing some semblance of a longwave trough across western North America leading to fairly strong (warm and dry) southwest momentum across the Rockies. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Sunday MORNING) ISSUED AT 556 AM CDT SAT SEP 19 2015 Surface high pressure centered in Nebraska will move into Iowa by 00Z. Pressures will begin to fall in the lee of the Rockies this afternoon as an upper level trough moves from Idaho into eastern Wyoming. An area of stratus with ceilings near 015 extending from southeast South Dakota into northern Kansas will propagate south and gradually erode during the morning hours. Ceilings from 010 to 015 will persist in HYS through the morning and scatter out around 17Z. The stratus will approach DDC by 14Z but should remain mostly east of the TAF location. Other than the area of stratus, VFR conditions will prevail through 12Z Sunday. A few showers and possibly a thunderstorm with bases near 070 can be expected after 06Z in GCK and around 09Z in DDC. && .PRELIMINARY POINT TEMPS/POPS... DDC 73 55 76 58 / 0 10 10 0 GCK 74 53 81 57 / 0 10 10 0 EHA 74 50 85 56 / 0 10 10 0 LBL 75 54 85 58 / 0 20 10 0 HYS 71 52 79 59 / 0 10 10 0 P28 74 58 76 60 / 0 20 20 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ SYNOPSIS...JJohnson SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Ruthi
AREA FORECAST DISCUSSION
NWS GOODLAND KS
522 AM MDT SAT SEP 19 2015 .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 208 AM MDT SAT SEP 19 2015 AFTER A CHILLY MORNING...PATCHY FOG AND LOW CLOUDS WILL DISSIPATE WITH MOSTLY SUNNY SKIES BY THE AFTERNOON. HIGH TEMPERATURES WILL BE NEAR SEASONAL NORMALS. TONIGHT...SHORTWAVE EMBEDDED IN ZONAL FLOW ACROSS THE NORTHERN CONUS WILL RESULT IN WEAK SYNOPTIC SCALE LIFT. HOWEVER MOISTURE WILL BE LIMITED AND NONE OF THE MESOSCALE MODELS GENERATE PRECIPITATION...SO WILL REMOVE MENTION OF THUNDERSTORMS AND KEEP POPS AT 10 PERCENT. UPPER RIDGE WILL REBUILD OVER THE REGION SUNDAY AND MONDAY WITH DRY CONDITIONS AND TEMPERATURES WARMING BACK INTO THE 80S ON SUNDAY AND NEAR 90 ON MONDAY. RELATIVE HUMIDITY VALUES WILL DROP TO NEAR 15 PERCENT PRIMARILY IN EASTERN COLORADO BOTH DAYS...BUT WIND SPEEDS WILL BE RELATIVELY LIGHT SO DO NOT EXPECT TO REACH RED FLAG CRITERIA. .LONG TERM...(TUESDAY THROUGH FRIDAY) ISSUED AT 208 AM MDT SAT SEP 19 2015 UPPER LEVEL RIDGING IS OVER THE AREA AT THE START OF THE EXTENDED PERIOD WITH A LEE TROUGH DEVELOPED NEAR THE COLORADO/KANSAS BORDER AT THE SURFACE. THIS WILL KEEP THE FORECAST DRY FOR TUESDAY/TUESDAY NIGHT AS SOUTHERLY SURFACE WINDS BRING WARM TEMPERATURES TO THE REGION. SOUTHWEST FLOW ALOFT WILL CARRY TROPICAL MOISTURE ONTO THE SOUTHWESTERN CONUS FROM THE BAJA PENINSULA ON TUESDAY...WHICH WILL CONTINUE NORTHEAST TOWARDS THE HIGH PLAINS. THIS COINCIDES WITH AN UPPER LEVEL LOW PRESSURE SYSTEM COMING ONTO THE SOUTHERN CALIFORNIA COAST BEFORE WEAKENING TO AN OPEN WAVE AS IT APPROACHES THE REGION. MULTIPLE SHORTWAVES DEVELOP WITHIN THIS SOUTHWEST FLOW ALOFT...IMPACTING THE FORECAST AREA WEDNESDAY THROUGH THURSDAY NIGHT. HOWEVER...MODELS DISAGREE ON THE TIMING AND PLACEMENT OF THESE DISTURBANCES...SO THIS WILL HAVE TO BE MONITORED. KEPT SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS DURING THE WEDNESDAY TO THURSDAY NIGHT TIME FRAME. UPPER LEVEL RIDGING APPEARS TO REBUILD ON FRIDAY...BRINGING DRY CONDITIONS BACK TO THE FORECAST. A VERY GRADUAL COOLING TREND IS EXPECTED FOR THE EXTENDED PERIOD WITH HIGHS IN THE UPPER 80S TO LOW 90S ON TUESDAY DECREASING THROUGH THE WORK WEEK TO THE LOW 80S ON FRIDAY. A SIMILAR TREND WILL BE SEEN WITH LOW TEMPERATURES WHICH WILL RANGE FROM THE 50S TO MID 60S. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 519 AM MDT SAT SEP 19 2015 LOW CLOUDS WILL IMPACT KMCK WITH IFR CEILINGS THROUGH LATE MORNING BEFORE CLEARING. UNCERTAIN IF THE LOW CLOUDS WILL MAKE IT AS FAR AS KGLD...BUT WILL CONTINUE TO MONITOR AS SATELLITE SHOWS THEM SPREADING QUICKLY WEST. LATEST RUN OF THE HRRR HAS THEM REACHING TO ABOUT COLBY BEFORE DISSIPATING AFTER 15Z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...024 LONG TERM...JBH AVIATION...024
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
557 AM CDT SAT SEP 19 2015 ...Updated Aviation Section... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 111 AM CDT SAT SEP 19 2015 The main challenge in the short term will be low stratus potential up in the northeast zones (particularly around Hays) and if it will impact temperatures at all. A secondary push of cooler air was making its way south into southwest Kansas with a slight bump in winds from the north. On the 11-3.9u imagery during the overnight hours, we were watching an area of stratus advance south- southwestward toward north central KS. The HRRR suggests that this will reach as far southwest as a Dighton to Dodge City line by 14z. This may be a bit ambitious, but there is certainly some merit to this prog as there is some better low level moisture across central/south central Nebraska that wrapped around the low...which will likely continue to advect southwestward through the early morning hours. We will bump up the clouds in the Sky grids to reflect this latest thinking, especially northeast of the Dighton to Dodge City line. Any low stratus should erode by late morning given how shallow it will be. Temperatures today, with the fresh Canadian airmass in place, will only top out in the lower to mid 70s. Will go with slightly cooler temps in the north where low morning clouds will likely delay the diurnal warmup. Advancing to tonight, we will see low level winds turn back around to the south in response to another loosely organized Pacific system moving into the Northern Rockies. Some marginal moisture will return via the "scenic route" (Eastern New Mexico/western TX-OK Panhandles), and increased deformation/convergence in the 700-800mb layer will promote some elevated showers and isolated thunderstorms after 06z Sunday. We will maintain the 20-30 POPs across mainly the western third of the forecast area late tonight, with low Chance POPs between the Arkansas River and the OK border in the 12-18z Sunday time frame. .LONG TERM...(Sunday THROUGH Friday) ISSUED AT 352 AM CDT SAT SEP 19 2015 Our region of the world will once again see a warming trend going into next week as the primary polar jet shifts back to the north and mid level heights rise across the Southern and Central Rockies/adjacent High Plains. During the slow transition back into above-average temperatures, we will see low chances for precipitation, particularly early Sunday as one last shortwave trough ripples through the longwave trough. Highs Sunday will be tricky, and we feel that portions of south central Kansas, especially, will stay stuck in the 60s to lower 70s with elevated convection and stratus clouds lingering through at least the middle part of the day. The lee trough comes back strong by Monday and will be a quasi- steady feature through at least Wednesday. Afternoon temperatures will gradually increase each day with highs in the lower 90s in some locations. The global spectral models suggest a subtropical shortwave trough ejecting from the Baja California region into Rockies which will bring some mid level moisture across into the High Plains. We will have some Slight Chance to Chance POPs in the grids Wednesday Night through Thursday Night, but at this point, it does not look like a real good opportunity for widespread beneficial rainfall across our region given the degree of downslope momentum in the middle troposphere and the general weak nature of the subtropical system to begin with. Beyond mid-week, it certainly looks like we will continue the theme of above average temperatures across the Rockies and adjacent High Plains in the final days of September with both the GFS and the ECMWF showing some semblance of a longwave trough across western North America leading to fairly strong (warm and dry) southwest momentum across the Rockies. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Sunday MORNING) ISSUED AT 556 AM CDT SAT SEP 19 2015 Surface high pressure centered in Nebraska will move into Iowa by 00Z. Pressures will begin to fall in the lee of the Rockies this afternoon as an upper level trough moves from Idaho into eastern Wyoming. An area of stratus with ceilings near 015 extending from southeast South Dakota into northern Kansas will propagate south and gradually erode during the morning hours. Ceilings from 010 to 015 will persist in HYS through the morning and scatter out around 17Z. The stratus will approach DDC by 14Z but should remain mostly east of the TAF location. Other than the area of stratus, VFR conditions will prevail through 12Z Sunday. A few showers and possibly a thunderstorm with bases near 070 can be expected after 06Z in GCK and around 09Z in DDC. && .PRELIMINARY POINT TEMPS/POPS... DDC 73 55 75 59 / 0 20 30 10 GCK 74 53 80 58 / 10 30 30 10 EHA 74 50 84 57 / 10 20 20 10 LBL 75 54 84 59 / 10 30 20 10 HYS 70 52 78 60 / 0 10 20 10 P28 74 58 75 61 / 0 20 20 10 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Ruthi
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
915 AM MDT SAT SEP 19 2015 .UPDATE... JUST A FEW TWEAKS FOR THE MORNING UPDATE. RAP SOUNDINGS SHOWED GOOD MIXING POTENTIAL TODAY WHICH WILL PRODUCE BREEZY/WINDY CONDITIONS CENTRAL AND W. NOTED KLVM AND KBIL WERE ALREADY GUSTING THIS MORNING...AND EXPECT SUBSIDENCE BEHIND THE DEPARTING SHORTWAVE TO AID IN GUSTY WINDS. THUS HAVE RAISED WIND SPEEDS OVER THE CENTRAL AND W ZONES. NOT MUCH CLOUD COVER EXPECTED TODAY WITH THE WAVE MOVING OUT AND CLOUDS CONFINED TO N OF CANADIAN BORDER WITH THE ZONAL JET. GIVEN THE LIMITED CLOUD COVER AND GOOD MIXING HAVE RAISED HIGH TEMPERATURES IN SEVERAL AREAS TOWARD THE RUC GUIDANCE. DOWNSLOPE FLOW WILL ALSO SUPPORT HIGHER TEMPERATURES. LOWERED CLOUD COVER IN THE GRIDS FOR TODAY. ARTHUR && .SHORT TERM...VALID FOR TDY AND SUN... SHORT WAVE TROUGH MOVING ACROSS OUR FORECAST AREA AT THIS TIME ONLY ABLE TO PRODUCE SOME CLOUD COVER DUE TO DRY LOWER LEVELS. WE WILL SLOWLY TRANSITION TO ZONAL FLOW BEHIND THIS WAVE BY SUNDAY. LEE-SIDE SURFACE TROUGHING THROUGH THE WEEKEND WILL LEAD TO WARMING WITH HIGHS IN THE LOWER TO MID 70S TODAY...FOLLOWED BY UPPER 70S TO LOWER 80S SUNDAY. LOOK FOR STIFF W/SW WINDS LATE MORNING THROUGH AFTERNOON EACH DAY...ESPECIALLY FROM BILLINGS WEST TO LIVINGSTON. PROGGS INDICATE WIND DIRECTION WILL HAVE TOO MUCH OF A WESTERLY COMPONENT FOR ANY SIGNIFICANT GAP EFFECTS AT LIVINGSTON/NYE...BUT WILL CERTAINLY BE WINDY AT TIMES. BT .LONG TERM...VALID FOR MON...TUE...WED...THU...FRI... NO SIGNIFICANT CHANGES IN THE EXTENDED OUTSIDE OF BORDER COLLABORATION AND NEW PERIODS. MODELS CONTINUE IN GOOD AGREEMENT...WITH GENERALLY WARM AND DRY CONDITIONS THROUGH THE WORK WEEK...UNDER ZONAL FLOW ALOFT THROUGH WEDNESDAY. THAT SAID...THERE IS A WEAK SHORTWAVE SLIDES ACROSS THE NORTHERN TIER OF THE CWA MONDAY NIGHT INTO TUESDAY...WITH JUST ENOUGH ENERGY THAT IT COULD BRING A SLIGHT CHANCE OF PRECIP IN THE EASTERN ZONES. SOUTHWEST FLOW BEGINS TO RETURN TO THE REGION WEDNESDAY NIGHT...AS THE REMNANTS OF THE SUB-TROPICAL SYSTEM LIFTING OUT OF THE PACIFIC SOUTHWEST APPEAR TO REACH THE AREA. AT THIS TIME THIS SYSTEM ONLY LOOKS LIKE IT WILL BRING SOME ISOLATED TO SCATTERED MOUNTAIN PRECIP...AND AN ISOLATED CHANCE TO EASTERNMOST ZONES. SOUTHWEST FLOW DEEPENS INTO THE WEEKEND IN ADVANCE OF THE APPROACHING STRONG PACIFIC TROF...SO HAVE KEPT SOME SLIGHT MOUNTAIN POPS IN PLACE IN THE MOUNTAINS. THE REMAINDER OF THE PERIOD IS A BIT MORE UNCERTAIN. TIMING IS A INCONSISTENT AMONGST MODELS WITH THE PROGRESSION OF THE TROF...BUT IN GOOD AGREEMENT ON IMPACTING THE REGION OVER THE WEEKEND AND EARLY NEXT WEEK. THE ECMWF DOES INDICATE A SLOWER PROGRESSION WITH GREATER PRECIP POTENTIAL AT THIS TIME...BUT MUCH CAN CHANGE IN A WEEK. AAG && .AVIATION... WINDS WILL BE INCREASING FROM WEST TO EAST THIS MORNING AND EARLY AFTERNOON ACROSS ALL ROUTES. STRONGEST WINDS WILL BE IN AND AROUND KLVM AND K6SO...WITH GUSTS OF 25 TO 35 KNOTS. GUSTS APPROACHING 20 KNOTS ACROSS EASTERN MONTANA...INCLUDING KBIL...KMLS...AND KBHK. WINDS WILL TAPER OFF AGAIN THIS EVENING. OTHERWISE VFR CONDITIONS WILL PREVAIL OVER THE FEW DAYS...UNDER CLEAR TO PARTLY CLOUDY SKIES. AAG/REIMER && .PRELIMINARY POINT TEMP/POPS... TDY SUN MON TUE WED THU FRI ------------------------------------------------------- BIL 076 050/080 053/077 048/078 054/080 053/080 053/082 0/B 00/B 01/B 11/B 11/B 12/T 22/T LVM 071 043/078 046/075 043/078 047/079 047/079 048/080 0/N 00/N 02/W 11/U 11/B 22/T 23/T HDN 077 045/082 048/080 046/081 051/082 050/083 050/085 0/B 00/B 01/B 11/B 12/W 11/B 11/B MLS 076 049/081 052/078 048/080 052/081 053/080 053/085 0/B 00/U 01/U 22/W 11/B 12/W 12/T 4BQ 076 047/081 049/080 048/081 052/082 052/081 051/085 0/B 00/U 01/U 11/U 12/W 11/B 11/B BHK 074 046/078 050/077 046/074 050/078 051/076 051/080 0/B 00/U 01/U 22/W 12/W 12/T 22/T SHR 074 042/080 046/080 045/083 049/082 048/082 048/085 0/B 00/U 01/U 11/U 12/W 12/T 21/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORMAN OK
657 AM CDT SAT SEP 19 2015 .DISCUSSION... PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW. && .AVIATION... BRIEF MVFR CIGS ARE EXPECTED THIS MORNING AT A FEW OF THE TERMINALS...BUT CONDITIONS WILL IMPROVE TO VFR AROUND 14-16Z. ALL OF THE SHOWERS/STORMS HAVE MOVED INTO SE OK THIS MORNING SO DO NOT EXPECT ANY PRECIP OVER THE TERMINALS FOR THE NEXT 12 HOURS. MID TO HIGH CLOUDS WILL REMAIN OVERHEAD THROUGH MOST OF THE DAY. EXPECT NORTH WINDS THROUGH THE AFTERNOON...SHIFTING TO THE ENE THIS EVENING. && .PREV DISCUSSION... /ISSUED 313 AM CDT SAT SEP 19 2015/ DISCUSSION... SCATTERED SHOWERS AND THUNDERSTORMS WILL SLOWLY CONTINUE TO SLIDE SOUTH WITH THE 850 MB FRONTOGENETIC ZONE THROUGH THE MORNING HOURS. THE HRRR HAS THE BEST HANDLE ON WHAT IS OCCURRING RIGHT NOW SO POPS WERE ADJUSTED UPWARD ALONG THIS NARROW ZONE THROUGH SUNRISE. MOST OF THE RAIN WILL MOVE TOWARD THE RED RIVER BEFORE LUNCHTIME AND SKIES WILL CONTINUE TO CLEAR FROM NE TO SW. EXPECT LINGERING STRATUS ACROSS THE SW...HOWEVER...THROUGH MOST OF THE DAY. MUCH COOLER TEMPS ARE EXPECTED TODAY BEHIND THE COLD FRONT FROM THE MID 70S NORTHWARD TO THE LOW 80S SOUTHWARD. THE NEXT CHANCE FOR RAIN RETURNS SUN AS ISENTROPIC ASCENT DEVELOPS AND A WEAK MID LEVEL SHORTWAVE TROUGH MOVES OUT OF THE ROCKIES. THE HIGHEST CHANCES WILL LIKELY BE DURING THE MORNING HOURS ACROSS WESTERN AND CENTRAL OK...AND THEN SHIFT NE/E DURING THE DAY. DECIDED TO LOWER TEMPS ACROSS THE NORTH AND EAST FOR THIS REASON SIMILAR TO THE NAM12. RAIN CHANCES WILL LINGER ACROSS THE EAST THROUGH EARLY MON AM AS A MORE SIGNIFICANT MID TO UPPER LEVEL SHORTWAVE TROUGH MOVES INTO NE/E OK. MONDAY SHOULD BE MOSTLY CLEAR AS THE WAVE QUICKLY MOVES INTO THE MISS RIVER VALLEY. TEMPS WILL BEGIN TO REBOUND BACK TO/OR JUST ABOVE AVG MONDAY...AND THEN WARM UP THROUGH MID WEEK AS THE SUBTROPICAL RIDGE MOVES OVER THE SOUTHERN PLAINS. MOST OF THE NWP MODELS INDICATE A MID TO UPPER SHORTWAVE TROUGH WILL MOVE SOMEWHERE NEAR KS THROUGH THURS SO WILL GO WITH SOME SLIGHT CHCS ACROSS NORTHERN OK DURING THIS TIME PERIOD. OTHERWISE...EXPECT ABOVE AVG TEMPS THROUGH THE EXTENDED PERIOD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 76 61 81 64 / 20 40 50 30 HOBART OK 77 62 85 65 / 20 50 50 20 WICHITA FALLS TX 82 66 88 67 / 40 40 40 20 GAGE OK 76 58 84 62 / 10 30 40 10 PONCA CITY OK 77 57 76 62 / 10 20 30 30 DURANT OK 84 67 86 66 / 30 40 50 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 26/03/03
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
731 AM EDT SAT SEP 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. HIGH PRESSURE WILL BRING A RETURN OF NEAR NORMAL DAYTIME TEMPERATURES FOR SUNDAY AND CONTINUE INTO THE MIDDLE OF NEXT WEEK. AN UPPER LEVEL LOW MAY LEAD TO A FEW SHOWERS MONDAY OR TUESDAY OVER THE SOUTHERN MOUNTAINS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3AM...THE SURFACE LOW WAS NEAR CHICAGO WITH THE COLD FRONT TRAILING SOUTH THROUGH ILLINOIS. THERE IS GOOD AGREEMENT ON THE TIMING OF THE FRONT...ENTERING WESTERN PA BY ABOUT 18Z...AND MOVING INTO THE SUSQ VALLEY BY 00Z. THERE IS ALSO GOOD AGREEMENT WITH THE PARENT UPPER SHORTWAVE SHEARING OUT THROUGH THE EASTERN LAKES AND SOUTHERN CANADA...LEADING TO A WEAKENING OF THE LARGE SCALE FORCING FOR THE SHOWERS AND THUNDERSTORMS CURRENTLY TRACKING EAST OVER CENTRAL LAKE ERIE DOWN INTO FAR NORTHERN OHIO. EXTRAPOLATION AND HRRR TIMING SUGGEST THESE BEGIN TO ENCROACH ON MY FAR NWRN ZONES BETWEEN ABOUT 7 AND 9 AM...11-13Z. THESE LEADING SHOWERS AND STORMS ARE MADE TO WEAKEN BY THE NEAR TERM MESO MODELS AS THEY MOVE OUT OF THE MOUNTAINS. ADDITIONAL CONVECTION ALONG THE COLD FRONT WILL ORGANIZE TO THE WEST AND ENTER THE NWRN MOUNTAINS ONCE AGAIN BY EARLY TO MID AFTERNOON...WITH A BETTER CHANCE OF SURVIVING INTO THE CENTRAL MOUNTAINS BY LATER TODAY AND THIS EVENING. THE WEAKENING TREND IN THE MODELS IS CONSISTENT AS THE FRONT PUSHES EAST...AND IT REMAINS UNCLEAR HOW MUCH EAST OF A LINE FROM ABOUT WILLIAMSPORT TO STATE COLLEGE TO ABOUT BEDFORD THE RAIN WILL MANAGE TO GET BEFORE PETERING OUT. THE HIGHEST CHANCES FOR RAIN WILL BE OVER NORTHERN AND NORTHWESTERN AREAS WHERE I HAVE CATEGORICAL POPS FOR TODAY. THE NUMBERS TAPER DOWN QUICKLY INTO THE CENTRAL MOUNTAINS AND LOWER STILL OVER MY SERN ZONES. QPF WILL RANGE FROM MEAGER AMOUNTS FROM THE MIDDLE SUSQUEHANNA VALLEY WEST TO THE LAURELS...TO PERHAPS .50" TO .75" OVER THE FAR NW. MODEST INSTABILITY AND MARGINAL WIND PROFILES SHOULD LIMIT SEVERE POTENTIAL TODAY...BUT SPC HAS PAINTED NWRN PA WITH A MARGINAL RISK FOR SEVERE STORMS TODAY. THE BEST CHANCE SEEMS TO BE IF A STRONG LINE CAN FORM IN OHIO/LOWER LAKES AND TRACK INTO THE REGION BEFORE IT DECAYS THIS EVENING. WE`LL EEK OUT ONE MORE WARM DAY AHEAD OF THE COLD FRONT WITH HIGHS IN THE MID 70S TO MID 80S. A COOL DOWN WILL BEGIN TONIGHT AS HIGH PRESSURE PUSHES QUICKLY INTO THE EASTERN GR LAKES AND SHOVES THE COLD FRONT OFF TO THE SOUTH. LOWS WILL RANGE FROM THE CHILLY MID 40S OVER THE NORTH TO AROUND 60 IN THE SOUTHEAST. OVER AREAS WHERE SKIES CLEAR TONIGHT...FOG SEEMS LIKELY LATE. THE BEST CHANCE WOULD SEEM TO BE OVER THE NORTHERN MOUNTAINS. && .SHORT TERM /SUNDAY/... CLOUDS WILL SETTLE OFF TO THE SOUTH SUNDAY AS HIGH PRESSURE QUICKLY MOVES INTO NORTHERN PA/SOUTHERN NY. IT WILL BE A MARKEDLY COOLER DAY WITH HIGHS AVERAGING AROUND 10 DEG COOLER THAN TODAY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... CONFIDENCE IN THE EXTENDED FORECAST CONTINUES TO DWINDLE WITH EACH PASSING MODE RUN. EARLY IN THE PERIOD...MODELS AGREE IN BRINGING FAIRLY AMPLIFIED UPPER TROUGH THROUGH THE OHIO VALLEY INTO THE NERN US. THE RESULTING SOUTH-SOUTHEAST FLOW SHOULD BRING THE CHANCE OF SOME LIGHT RAINS FOR MONDAY AND POSSIBLY TUESDAY. AT THIS POINT I HAVE FAIRLY LOW CHANCES OF RAIN OVER MUCH OF THE AREA MONDAY AND MAINLY OVER SOUTHERN AREAS INTO TUESDAY. BEFORE THIS HAPPENS HOWEVER...WITH CLEAR SKIES...VERY DRY AIR AND LIGHT WINDS...LOWS OVER THE NWRN MOUNTAINS MONDAY MORNING WILL DROP DOWN INTO THE MIDDLE 30S. MAY SEE THE FIRST FROST OF THE SEASON IN A FEW OF THE NORMAL COLD SHELTERED LOCATIONS. FROM THERE MODEL SOLUTIONS DIVERGE FURTHER. THE ECMWF AND GFS/GEFS ALL SHOW THE UPPER TROUGH CLOSING OFF. WHAT HAPPENS THEN MEANS THE DIFFERENCE BETWEEN A MILD AND DRY REST OF THE WEEK...OR A COLD RAINY ONE. THE GFS/GEFS HAVE TRENDED MUCH FURTHER NORTH WITH THE UPPER LOW...KEEPING AN EXTENDED PERIOD OF MOIST EASTERLY LOW LEVEL FLOW FROM WEDNESDAY INTO FRIDAY. THIS WOULD RESULT IN A PERIOD OF CHILLY WET WEATHER. THE ECMWF ON THE OTHER HAND SETTLES THE LOW DOWN OVER THE SERN STATES AND EVEN TRACKS IT WEST ALONG THE GULF COAST FOR THE WEEKEND. THIS WOULD KEEP US UNDER FAVORABLE RIDGING NORTH OF THE SYSTEM...WITH DRY AND MILD CONDITIONS. I USED OUR SUPERBLENDED MODEL MOS WHICH DOWNPLAYS THE GFS/GEFS PESSIMISM...RESULTING IN A MUCH BRIGHTER FORECAST FROM MID WEEK ONWARD. PRESUMING THE OPTIMISTIC FORECAST VERIFIES...TEMPERATURES WHICH WILL START THE WEEK BELOW NORMAL WILL TREND BACK TO A BIT ABOVE NORMAL BY MID WEEK. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... SEVERAL BANDS OF SHOWERS AND STORMS EARLY...MAINLY ACROSS THE NW...GIVEN DYNAMICS. SOME FOG FOR A FEW MORE HOURS...BUT NOT AS EXTENSIVE AS THE LAST 2 MORNINGS. MAIN AREA FOR DENSE FOG AT TIMES HAS BEEN LNS. MOST OF THE DAY WILL BE DRY WITH VFR CONDITIONS. A COLD FRONT MOVING SE MAY BRING SOME MORE SHOWERS LATE. LOW CIGS POSSIBLE TONIGHT...BEHIND THE COLD FRONT. WEATHER NOT LOOKING BAD SUN INTO WED. OUTLOOK... SUN-WED...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE NEAR TERM...LA CORTE SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
540 AM CDT SAT SEP 19 2015 .UPDATE...FOR 12Z AVIATION DISCUSSION. && .AVIATION UPDATE...12Z AVIATION DISCUSSION. FIGURING IN SUBTLE MODEL DISCREPANCIES ON SFC FRONTAL PASSAGE TIMING... INCLUDING BELOW REFERENCED LIMITED MOISTURE POTENTIAL ALSO...BELIEVE AT BEST TAF SITES WILL EXPERIENCE MAINLY VFR CB CEILINGS WITH VCTS 19/16Z W TO 19/22Z E. ACTUAL CLRING TIMING AMOUNT OF POSSIBLE CEILING EROSION STILL IN QUESTION BEHIND SFC FRONTAL PASSAGE...BUT BELIEVE BECAUSE OF LATE AFTERNOON MIXING POTENTIAL CKV...A TRANSITION TO SCT AC OR SKC CONDITIONS POSSIBLE BY NO LATER THAN 20/03Z. VFR BKN STRATUS CEILINGS SHOULD PERSIST BNA THRU AT LEAST 20/10Z WITH A TRANSITION FROM HIGH END MVFR CEILINGS TO IFR CEILINGS CSV WITH MVFR FOG INDUCED VSBYS POSSIBLY 20/10Z. && PREV DISCUSSION.../ISSUED 354 AM CDT SAT SEP 19 2015/ DISCUSSION... SHORT TERM(TODAY-MON)... COLD FRONT IS CURRENTLY POSITIONED FROM CHI TOWN SW ACROSS NORTHERN TX. UPPER RIDGE AXIS ACROSS THE SOUTHEASTERN U.S. WILL BE SINKING SOUTHWARD AND UPPER LEVEL WESTERLIES SHOULD PREVAIL BY AFTERNOON. THIS WILL ACT TO MOVE THE FRONT OUR WAY. FROPA IS EXPECTED DURING THE LATE AFTERNOON HOURS. MOISTURE AVAILABILITY FOR THE APPROACHING FRONT WILL BE VERY LIMITED. IT DOES APPEAR THAT JUST ENOUGH INSTABILITY WILL RESIDE SO AS TO PROMOTE A LOW 20 POP FOR MOST OF THE AREA FOR TODAY AND THIS EVENING. THE ASSOCIATED UPPER LEVEL DYNAMICS WILL TAKE A NORTHERLY ROUTE...WELL NORTH OF TN. HRRR IS VERY STINGY WITH ANY APPRECIABLE PRECIP WITH THIS SYSTEM. WILL THEREFORE KEEP THE EXPECTED QPF FIELDS ON THE LOW SIDE. AT ANY RATE...CLOUDS WILL INCREASE SLOWLY BETWEEN NOW AND THIS EVENING. MOSTLY CLOUDY SKIES SHOULD PREVAIL FOR TONIGHT AND EARLY SUNDAY. THEN...WE`LL LEAN TOWARD PARTIAL CLOUD COVER. FOR THE NEAR TERM TEMPS...WARM AGAIN FOR TODAY. HIGHS WILL BE WELL INTO THE 80S FOR MOST AREAS. THE COOL DOWN WILL BEGIN TONIGHT AFTER THE FROPA. SUNDAY AND MONDAY WILL FEATURE HIGHS NEAR 80 WEST OF PLATEAU...WITH DEW POINTS IN THE 50S. OVERNIGHT LOWS WILL GENERALLY BE FROM 55 TO 60 FOR SUNDAY NIGHT...ABOUT 5 DEGREES COOLER THAN SAT NT. LONG TERM(TUE-SAT)... DISCREPANCIES BETWEEN MODEL SOLUTIONS STILL REMAIN WITH THIS MORNING`S RUNS...BUT A GENERAL TREND FOR MID TO LATER PORTIONS OF THE WORK WEEK TOWARD A COMPLETELY DRY FORECAST...WITH THE ONLY POTENTIAL OF RAINFALL POSSIBLY THE FIRST PART OF NEXT WEEKEND...AND EVEN THEN ONLY A SLIGHT CHANCE OF SHWRS ACROSS THE ERN HALF OF THE MID STATE. TEMPS WILL GENERALLY BE AROUND OR MAYBE A FEW DEGREES HERE AND THERE ABOVE SEASONAL NORMAL VALUES. MOSTLY CLEAR TO PTCLDY SKIES ARE CONTINUED TO BE EXPECTED THRU THIS PERIOD TOO. BROAD SURFACE HIGH PRESSURE INFLUENCES ALONG WITH BUILDING UPPER LEVEL RIDGING INFLUENCES WILL BE THE MAJOR WX PLAYER THRU THIS PERIOD. DEPENDING ON MODEL LEAN...UPPER LEVEL CLOSED LOW CIRCULATION THAT PREVIOUSLY WAS EXPECTED TO PLAY A ROLE IN BRINGING CONVECTIVE CHANCES TO THE MID STATE PLATEAU WED AFTERNOON AND ON FRI... LOOKS TO DEVELOP BY THE MID PORTION OF NEXT WORK WEEK IN AN UPPER LEVEL TROUGHING PATTERN OVER THE CAROLINA`S AND EITHER EVENTUALLY GO NEWD OF OR SWD OF MID STATE...GENERALLY RESULTING IN NO SIGNIFICANT IMPACTS TO THE MID STATE. MENTION OF ISO SHWRS ON SAT PER POSSIBILITY OF SOME MOISTURE BEING USHERED ACROSS ERN HALF IF CIRCULATION ACTUALLY MOVES NEWD. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 88 63 80 59 / 20 20 10 10 CLARKSVILLE 86 58 78 54 / 30 10 10 10 CROSSVILLE 82 62 77 57 / 10 20 20 10 COLUMBIA 88 62 80 58 / 20 20 10 10 LAWRENCEBURG 87 63 80 59 / 10 10 10 10 WAVERLY 87 59 78 56 / 20 20 10 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
537 AM CDT SAT SEP 19 2015 .UPDATE...FOR 12Z AVIATION DISCUSSION. && .AVIATION UPDATE...12Z AVIATION DISCUSSION. FIGURING IN SUBTLE MODEL DISCREPANCIES ON SFC FRONTAL PASSAGE TIMING... INCLUDING BELOW REFERENCED LIMITED MOISTURE POTENTIAL ALSO... BELIEVE AT BEST TAF SITES WILL EXPERIENCE MAINLY VFR CB CEILINGS WITH VCTS 19/16Z W TO 19/22Z E. ACTUAL CLRING TIMING AMOUNT OF POSSIBLE CEILING EROSION STILL IN QUESTION BEHIND SFC FRONTAL PASSAGE...BUT BELIEVE BECAUSE OF LATE AFTERNOON MIXING POTENTIAL CKV...A TRANSITION TO SCT AC OR SKC CONDITIONS POSSIBLE BY NO LATER THAN 20/03Z. VFR BKN STRATUS CEILINGS SHOULD PERSIST BNA THRU AT LEAST 20/10Z WITH A TRANSITION FROM HIGH END MVFR CEILINGS TO IFR CEILINGS CSV WITH MVFR FOG INDUCED VSBYS POSSIBLY 20/10Z. && .PREV DISCUSSION.../ISSUED 532 AM CDT SAT SEP 19 2015/ UPDATE...FOR 12Z AVIATION DISCUSSION. AVIATION UPDATE...12Z AVIATION DISCUSSION. FIGURING IN SUBTLE MODEL DISCREPANCIES ON SFC FRONTAL PASSAGE TIMING... INCLUDING BELOW REFERENCED LIMITED MOISTURE POTENTIAL ALSO...BELIEVE AT BEST TAF SITES WILL EXPERIENCE MAINLY VFR CB CEILINGS WITH VCTS 19/16Z W TO 19/22Z E. ACTUAL CLRING TIMING AMOUNT OF POSSIBLE CEILING EROSION STILL IN QUESTION BEHIND SFC FRONTAL PASSAGE...BUT BELIEVE BECAUSE OF LATE AFTERNOON MIXING POTENTIAL CKV...A TRANSITION TO SCT AC OR SKC CONDITIONS POSSIBLE BY NO LATER THAN 20/03Z. VFR BKN STRATUS CEILINGS SHOULD PERSIST BNA THRU AT LEAST 20/10Z WITH A TRANSITION FROM HIGH END MVFR CEILINGS TO IFR CEILINGS CSV WITH MVFR FOG INDUCED VSBYS POSSIBLY 20/10Z. PREV DISCUSSION.../ISSUED 354 AM CDT SAT SEP 19 2015/ DISCUSSION... SHORT TERM(TODAY-MON)... COLD FRONT IS CURRENTLY POSITIONED FROM CHI TOWN SW ACROSS NORTHERN TX. UPPER RIDGE AXIS ACROSS THE SOUTHEASTERN U.S. WILL BE SINKING SOUTHWARD AND UPPER LEVEL WESTERLIES SHOULD PREVAIL BY AFTERNOON. THIS WILL ACT TO MOVE THE FRONT OUR WAY. FROPA IS EXPECTED DURING THE LATE AFTERNOON HOURS. MOISTURE AVAILABILITY FOR THE APPROACHING FRONT WILL BE VERY LIMITED. IT DOES APPEAR THAT JUST ENOUGH INSTABILITY WILL RESIDE SO AS TO PROMOTE A LOW 20 POP FOR MOST OF THE AREA FOR TODAY AND THIS EVENING. THE ASSOCIATED UPPER LEVEL DYNAMICS WILL TAKE A NORTHERLY ROUTE...WELL NORTH OF TN. HRRR IS VERY STINGY WITH ANY APPRECIABLE PRECIP WITH THIS SYSTEM. WILL THEREFORE KEEP THE EXPECTED QPF FIELDS ON THE LOW SIDE. AT ANY RATE...CLOUDS WILL INCREASE SLOWLY BETWEEN NOW AND THIS EVENING. MOSTLY CLOUDY SKIES SHOULD PREVAIL FOR TONIGHT AND EARLY SUNDAY. THEN...WE`LL LEAN TOWARD PARTIAL CLOUD COVER. FOR THE NEAR TERM TEMPS...WARM AGAIN FOR TODAY. HIGHS WILL BE WELL INTO THE 80S FOR MOST AREAS. THE COOL DOWN WILL BEGIN TONIGHT AFTER THE FROPA. SUNDAY AND MONDAY WILL FEATURE HIGHS NEAR 80 WEST OF PLATEAU...WITH DEW POINTS IN THE 50S. OVERNIGHT LOWS WILL GENERALLY BE FROM 55 TO 60 FOR SUNDAY NIGHT...ABOUT 5 DEGREES COOLER THAN SAT NT. LONG TERM(TUE-SAT)... DISCREPANCIES BETWEEN MODEL SOLUTIONS STILL REMAIN WITH THIS MORNING`S RUNS...BUT A GENERAL TREND FOR MID TO LATER PORTIONS OF THE WORK WEEK TOWARD A COMPLETELY DRY FORECAST...WITH THE ONLY POTENTIAL OF RAINFALL POSSIBLY THE FIRST PART OF NEXT WEEKEND...AND EVEN THEN ONLY A SLIGHT CHANCE OF SHWRS ACROSS THE ERN HALF OF THE MID STATE. TEMPS WILL GENERALLY BE AROUND OR MAYBE A FEW DEGREES HERE AND THERE ABOVE SEASONAL NORMAL VALUES. MOSTLY CLEAR TO PTCLDY SKIES ARE CONTINUED TO BE EXPECTED THRU THIS PERIOD TOO. BROAD SURFACE HIGH PRESSURE INFLUENCES ALONG WITH BUILDING UPPER LEVEL RIDGING INFLUENCES WILL BE THE MAJOR WX PLAYER THRU THIS PERIOD. DEPENDING ON MODEL LEAN...UPPER LEVEL CLOSED LOW CIRCULATION THAT PREVIOUSLY WAS EXPECTED TO PLAY A ROLE IN BRINGING CONVECTIVE CHANCES TO THE MID STATE PLATEAU WED AFTERNOON AND ON FRI... LOOKS TO DEVELOP BY THE MID PORTION OF NEXT WORK WEEK IN AN UPPER LEVEL TROUGHING PATTERN OVER THE CAROLINA`S AND EITHER EVENTUALLY GO NEWD OF OR SWD OF MID STATE...GENERALLY RESULTING IN NO SIGNIFICANT IMPACTS TO THE MID STATE. MENTION OF ISO SHWRS ON SAT PER POSSIBILITY OF SOME MOISTURE BEING USHERED ACROSS ERN HALF IF CIRCULATION ACTUALLY MOVES NEWD. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 88 63 80 59 / 20 20 10 10 CLARKSVILLE 86 58 78 54 / 30 10 10 10 CROSSVILLE 82 62 77 57 / 10 20 20 10 COLUMBIA 88 62 80 58 / 20 20 10 10 LAWRENCEBURG 87 63 80 59 / 10 10 10 10 WAVERLY 87 59 78 56 / 20 20 10 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
532 AM CDT SAT SEP 19 2015 .UPDATE...FOR 12Z AVIATION DISCUSSION. && .AVIATION UPDATE...12Z AVIATION DISCUSSION. FIGURING IN SUBTLE MODEL DISCREPANCIES ON SFC FRONTAL PASSAGE TIMING... INCLUDING BELOW REFERENCED LIMITED MOISTURE POTENTIAL ALSO...BELIEVE AT BEST TAF SITES WILL EXPERIENCE MAINLY VFR CB CEILINGS WITH VCTS 19/16Z W TO 19/22Z E. ACTUAL CLRING TIMING AMOUNT OF POSSIBLE CEILING EROSION STILL IN QUESTION BEHIND SFC FRONTAL PASSAGE...BUT BELIEVE BECAUSE OF LATE AFTERNOON MIXING POTENTIAL CKV...A TRANSITION TO SCT AC OR SKC CONDITIONS POSSIBLE BY NO LATER THAN 20/03Z. VFR BKN STRATUS CEILINGS SHOULD PERSIST BNA THRU AT LEAST 20/10Z WITH A TRANSITION FROM HIGH END MVFR CEILINGS TO IFR CEILINGS CSV WITH MVFR FOG INDUCED VSBYS POSSIBLY 20/10Z. && .PREV DISCUSSION.../ISSUED 354 AM CDT SAT SEP 19 2015/ DISCUSSION... SHORT TERM(TODAY-MON)... COLD FRONT IS CURRENTLY POSITIONED FROM CHI TOWN SW ACROSS NORTHERN TX. UPPER RIDGE AXIS ACROSS THE SOUTHEASTERN U.S. WILL BE SINKING SOUTHWARD AND UPPER LEVEL WESTERLIES SHOULD PREVAIL BY AFTERNOON. THIS WILL ACT TO MOVE THE FRONT OUR WAY. FROPA IS EXPECTED DURING THE LATE AFTERNOON HOURS. MOISTURE AVAILABILITY FOR THE APPROACHING FRONT WILL BE VERY LIMITED. IT DOES APPEAR THAT JUST ENOUGH INSTABILITY WILL RESIDE SO AS TO PROMOTE A LOW 20 POP FOR MOST OF THE AREA FOR TODAY AND THIS EVENING. THE ASSOCIATED UPPER LEVEL DYNAMICS WILL TAKE A NORTHERLY ROUTE...WELL NORTH OF TN. HRRR IS VERY STINGY WITH ANY APPRECIABLE PRECIP WITH THIS SYSTEM. WILL THEREFORE KEEP THE EXPECTED QPF FIELDS ON THE LOW SIDE. AT ANY RATE...CLOUDS WILL INCREASE SLOWLY BETWEEN NOW AND THIS EVENING. MOSTLY CLOUDY SKIES SHOULD PREVAIL FOR TONIGHT AND EARLY SUNDAY. THEN...WE`LL LEAN TOWARD PARTIAL CLOUD COVER. FOR THE NEAR TERM TEMPS...WARM AGAIN FOR TODAY. HIGHS WILL BE WELL INTO THE 80S FOR MOST AREAS. THE COOL DOWN WILL BEGIN TONIGHT AFTER THE FROPA. SUNDAY AND MONDAY WILL FEATURE HIGHS NEAR 80 WEST OF PLATEAU...WITH DEW POINTS IN THE 50S. OVERNIGHT LOWS WILL GENERALLY BE FROM 55 TO 60 FOR SUNDAY NIGHT...ABOUT 5 DEGREES COOLER THAN SAT NT. LONG TERM(TUE-SAT)... DISCREPANCIES BETWEEN MODEL SOLUTIONS STILL REMAIN WITH THIS MORNING`S RUNS...BUT A GENERAL TREND FOR MID TO LATER PORTIONS OF THE WORK WEEK TOWARD A COMPLETELY DRY FORECAST...WITH THE ONLY POTENTIAL OF RAINFALL POSSIBLY THE FIRST PART OF NEXT WEEKEND...AND EVEN THEN ONLY A SLIGHT CHANCE OF SHWRS ACROSS THE ERN HALF OF THE MID STATE. TEMPS WILL GENERALLY BE AROUND OR MAYBE A FEW DEGREES HERE AND THERE ABOVE SEASONAL NORMAL VALUES. MOSTLY CLEAR TO PTCLDY SKIES ARE CONTINUED TO BE EXPECTED THRU THIS PERIOD TOO. BROAD SURFACE HIGH PRESSURE INFLUENCES ALONG WITH BUILDING UPPER LEVEL RIDGING INFLUENCES WILL BE THE MAJOR WX PLAYER THRU THIS PERIOD. DEPENDING ON MODEL LEAN...UPPER LEVEL CLOSED LOW CIRCULATION THAT PREVIOUSLY WAS EXPECTED TO PLAY A ROLE IN BRINGING CONVECTIVE CHANCES TO THE MID STATE PLATEAU WED AFTERNOON AND ON FRI... LOOKS TO DEVELOP BY THE MID PORTION OF NEXT WORK WEEK IN AN UPPER LEVEL TROUGHING PATTERN OVER THE CAROLINA`S AND EITHER EVENTUALLY GO NEWD OF OR SWD OF MID STATE...GENERALLY RESULTING IN NO SIGNIFICANT IMPACTS TO THE MID STATE. MENTION OF ISO SHWRS ON SAT PER POSSIBILITY OF SOME MOISTURE BEING USHERED ACROSS ERN HALF IF CIRCULATION ACTUALLY MOVES NEWD. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 88 63 80 59 / 20 20 10 10 CLARKSVILLE 86 58 78 54 / 30 10 10 10 CROSSVILLE 82 62 77 57 / 10 20 20 10 COLUMBIA 88 62 80 58 / 20 20 10 10 LAWRENCEBURG 87 63 80 59 / 10 10 10 10 WAVERLY 87 59 78 56 / 20 20 10 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1002 AM CDT SAT SEP 19 2015 .UPDATE... BASED ON CURRENT RADAR TRENDS...HAVE UPDATED POPS FOR TODAY TO ACCOUNT FOR THE MORE WIDESPREAD COVERAGE OF SHOWERS AND STORMS IN THE NORTHEAST ZONES AND MORE SCATTERED COVERAGE OUT WEST. EXPECT THE COLD FRONT TO STALL AND BECOME LESS DEFINED THIS AFTERNOON...BUT SCATTERED SHOWERS AND STORMS WILL STILL BE POSSIBLE NEAR THIS BOUNDARY AS THE DAY PROGRESSES. AJS && .AVIATION... /ISSUED 714 AM CDT SAT SEP 19 2015/ /12Z TAFS/ DIFFUSE COLD FRONT EXTENDS FROM NEAR FT SMITH TO SHERMAN TO ABILENE AT 12Z. ZONAL FLOW ALOFT AND THE LACK OF A STRONG THUNDERSTORM-INDUCED COLD POOL OVER WRN OK HAS LIMITED THE SOUTHWARD PROGRESSION OF THIS BOUNDARY OVERNIGHT. NEVERTHELESS... THE FRONT SHOULD HAVE ENOUGH VIGOR TO PRESS ONWARD INTO THE INTERSTATE 20 CORRIDOR BY LATE MORNING...REACHING A CORSICANA- GOLDTHWAITE LINE BY 06Z TONIGHT. ONE OR MORE WEAK SURFACE OUTFLOW BOUNDARIES...ARISING FROM THE EARLY MORNING CONVECTION NW OF THE METROPLEX...SHOULD MOVE ACROSS THE DFW-AREA TAF SITES IN THE 12-14Z TIMEFRAME....TEMPORARILY VEERING WINDS AT SOME LOCATIONS TO A LIGHT WEST/NW DIRECTION. THE MAIN FRONT ITSELF SHOULD CLEAR ALL OF THESE TAF SITES BY 15-16Z...PRODUCING SUSTAINED N TO NE FLOW FROM LATE MORNING ONWARD THROUGH TONIGHT. ISOLATED TO SCATTERED SHOWERS HAVE ALREADY REACHED THE I-35 CORRIDOR AS OF 12Z...AND CONVERGENCE ALONG THE FRONT/OUTFLOW BOUNDARIES SHOULD BE SUFFICIENT TO MAINTAIN SCATTERED CONVECTIVE ACTIVITY ACROSS THE DFW AREA THROUGH 22Z. THROUGH 16Z THIS MORNING...THUNDERSTORM ACTIVITY SHOULD BE VERY ISOLATED. AS DAYTIME HEATING ENSUES...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ANYWHERE NORTH OF I-20 IN THE 16-22Z WINDOW. CEILINGS AND VISIBILITIES AT THE METROPLEX TAF SITES SHOULD REMAIN VFR TODAY...HOWEVER...EVEN IN AREAS THAT EXPERIENCE SHOWER ACTIVITY. THE FRONT SHOULD REMAIN JUST NORTH OF WACO THROUGH MOST OF TODAY...BUT CLOSE ENOUGH TO NUDGE SOUTHERLY WINDS BACK TO A SE- EAST DIRECTION AFTER 22Z. ISOLATED SHOWERS OR THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON NEAR WACO...BUT THE THREAT IS SUFFICIENTLY LOW TO PRECLUDE MENTION IN THE 12Z TAF. VFR CONDITIONS SHOULD PREVAIL AT WACO THROUGH TONIGHT. BRADSHAW && .PREV DISCUSSION... /ISSUED 240 AM CDT SAT SEP 19 2015/ THE COLD FRONT WAS LOCATED ALONG A LINE FROM FORT SMITH TO SOUTH OF LUBBOCK AT 07Z/2AM AND MOVING SOUTHEAST NEAR 18 MPH. AN OUTFLOW BOUNDARY AHEAD OF CONVECTION ALONG/BEHIND THE FRONT WILL WORK THROUGH THE NORTHWEST HALF OF THE CWA THIS MORNING WITH CONVECTION SPREADING SOUTHEASTWARD AS WELL. THE HRRR AND TT WRF SPREAD CONVECTION INTO THE NORTHWEST HALF OF THE DFW METROPLEX 10-12Z SO HAVE MAINTAINED CHANCE POPS OVER THE NORTHWEST HALF TODAY. THE FRONT WILL LIKELY MOVE TO NEAR A PALESTINE TO GOLDTHWAITE LINE BY MIDNIGHT TONIGHT...THEN DRIFT NORTHWARD A LITTLE EARLY SUNDAY AND STALL OUT JUST SOUTH OF I-20 DURING THE DAY WITH THE BEST CHANCE OF CONVECTION GENERALLY NORTH OF THE FRONT. THE WEST END OF THE FRONT LIFTS NORTHWARD ON SUNDAY NIGHT AND THEN THE ENTIRE FRONT LIFTS OUT NORTHEAST ON MONDAY. SUNDAY NIGHT POPS WILL SHIFT TO THE NORTHEAST COUNTIES AND MONDAY POPS WILL BE MAINLY OVER THE FAR EASTERN COUNTIES. SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING DUE TO A FAIR AMOUNT OF INSTABILITY ALONG THE FRONT....AND LOCALIZED HEAVY RAINFALL IS ALSO POSSIBLE DUE TO PWATS NEAR/AROUND 2 INCHES. HIGH TEMPERATURES TODAY WILL NOT CHANGE AHEAD OF THE FRONT BUT THEY WILL BE 5-10 DEGREES COOLER BEHIND IT. AS THE FRONT BECOMES DIFFUSED ON SUNDAY AND LIFTS OUT ON MONDAY...HIGH TEMPS WILL CREEP UPWARD WITH MOST OF THE CWA BACK IN THE LOWER TO MID 90S TUESDAY THROUGH FRIDAY. HAVE ADJUSTED OVERNIGHT LOWS DOWN 1-3 DEGREES...MAINLY RURAL AREAS...THURSDAY AND FRIDAY DUE TO DRIER AIR SPREADING INTO THE REGION. LOOKING AHEAD INTO NEXT WEEKEND AND THE LAST WEEK OF SEPTEMBER...BOTH THE GFS AND ECMWF MODELS ARE INDICATING A WEAKNESS ALOFT OVER THE SOUTHEAST OR SOUTHERN STATES AND THE UPPER RIDGE OFF TO OUR WEST. THIS PATTERN WOULD RESULT IN LOWER HEIGHTS ALOFT OVER NORTH AND CENTRAL TEXAS...AND THUS TEMPERATURES A LITTLE CLOSER TO NORMAL WITH HIGHS IN THE MID 80S TO LOWER 90S. 75 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 88 72 90 72 92 / 40 30 20 10 5 WACO, TX 93 70 95 71 93 / 10 10 10 5 5 PARIS, TX 87 67 87 66 87 / 50 20 30 30 20 DENTON, TX 87 69 89 68 91 / 50 40 20 20 5 MCKINNEY, TX 88 69 90 69 90 / 50 30 20 20 10 DALLAS, TX 89 73 90 71 92 / 40 30 20 10 5 TERRELL, TX 91 69 91 69 91 / 30 20 20 20 10 CORSICANA, TX 94 71 93 71 92 / 10 10 10 5 10 TEMPLE, TX 93 69 93 70 92 / 10 10 5 5 5 MINERAL WELLS, TX 87 67 90 68 91 / 40 40 20 10 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
714 AM CDT SAT SEP 19 2015 .AVIATION... /12Z TAFS/ DIFFUSE COLD FRONT EXTENDS FROM NEAR FT SMITH TO SHERMAN TO ABILENE AT 12Z. ZONAL FLOW ALOFT AND THE LACK OF A STRONG THUNDERSTORM-INDUCED COLD POOL OVER WRN OK HAS LIMITED THE SOUTHWARD PROGRESSION OF THIS BOUNDARY OVERNIGHT. NEVERTHELESS... THE FRONT SHOULD HAVE ENOUGH VIGOR TO PRESS ONWARD INTO THE INTERSTATE 20 CORRIDOR BY LATE MORNING...REACHING A CORSICANA- GOLDTHWAITE LINE BY 06Z TONIGHT. ONE OR MORE WEAK SURFACE OUTFLOW BOUNDARIES...ARISING FROM THE EARLY MORNING CONVECTION NW OF THE METROPLEX...SHOULD MOVE ACROSS THE DFW-AREA TAF SITES IN THE 12-14Z TIMEFRAME....TEMPORARILY VEERING WINDS AT SOME LOCATIONS TO A LIGHT WEST/NW DIRECTION. THE MAIN FRONT ITSELF SHOULD CLEAR ALL OF THESE TAF SITES BY 15-16Z...PRODUCING SUSTAINED N TO NE FLOW FROM LATE MORNING ONWARD THROUGH TONIGHT. ISOLATED TO SCATTERED SHOWERS HAVE ALREADY REACHED THE I-35 CORRIDOR AS OF 12Z...AND CONVERGENCE ALONG THE FRONT/OUTFLOW BOUNDARIES SHOULD BE SUFFICIENT TO MAINTAIN SCATTERED CONVECTIVE ACTIVITY ACROSS THE DFW AREA THROUGH 22Z. THROUGH 16Z THIS MORNING...THUNDERSTORM ACTIVITY SHOULD BE VERY ISOLATED. AS DAYTIME HEATING ENSUES...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ANYWHERE NORTH OF I-20 IN THE 16-22Z WINDOW. CEILINGS AND VISIBILITIES AT THE METROPLEX TAF SITES SHOULD REMAIN VFR TODAY...HOWEVER...EVEN IN AREAS THAT EXPERIENCE SHOWER ACTIVITY. THE FRONT SHOULD REMAIN JUST NORTH OF WACO THROUGH MOST OF TODAY...BUT CLOSE ENOUGH TO NUDGE SOUTHERLY WINDS BACK TO A SE- EAST DIRECTION AFTER 22Z. ISOLATED SHOWERS OR THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON NEAR WACO...BUT THE THREAT IS SUFFICIENTLY LOW TO PRECLUDE MENTION IN THE 12Z TAF. VFR CONDITIONS SHOULD PREVAIL AT WACO THROUGH TONIGHT. BRADSHAW && .PREV DISCUSSION... /ISSUED 240 AM CDT SAT SEP 19 2015/ THE COLD FRONT WAS LOCATED ALONG A LINE FROM FORT SMITH TO SOUTH OF LUBBOCK AT 07Z/2AM AND MOVING SOUTHEAST NEAR 18 MPH. AN OUTFLOW BOUNDARY AHEAD OF CONVECTION ALONG/BEHIND THE FRONT WILL WORK THROUGH THE NORTHWEST HALF OF THE CWA THIS MORNING WITH CONVECTION SPREADING SOUTHEASTWARD AS WELL. THE HRRR AND TT WRF SPREAD CONVECTION INTO THE NORTHWEST HALF OF THE DFW METROPLEX 10-12Z SO HAVE MAINTAINED CHANCE POPS OVER THE NORTHWEST HALF TODAY. THE FRONT WILL LIKELY MOVE TO NEAR A PALESTINE TO GOLDTHWAITE LINE BY MIDNIGHT TONIGHT...THEN DRIFT NORTHWARD A LITTLE EARLY SUNDAY AND STALL OUT JUST SOUTH OF I-20 DURING THE DAY WITH THE BEST CHANCE OF CONVECTION GENERALLY NORTH OF THE FRONT. THE WEST END OF THE FRONT LIFTS NORTHWARD ON SUNDAY NIGHT AND THEN THE ENTIRE FRONT LIFTS OUT NORTHEAST ON MONDAY. SUNDAY NIGHT POPS WILL SHIFT TO THE NORTHEAST COUNTIES AND MONDAY POPS WILL BE MAINLY OVER THE FAR EASTERN COUNTIES. SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING DUE TO A FAIR AMOUNT OF INSTABILITY ALONG THE FRONT....AND LOCALIZED HEAVY RAINFALL IS ALSO POSSIBLE DUE TO PWATS NEAR/AROUND 2 INCHES. HIGH TEMPERATURES TODAY WILL NOT CHANGE AHEAD OF THE FRONT BUT THEY WILL BE 5-10 DEGREES COOLER BEHIND IT. AS THE FRONT BECOMES DIFFUSED ON SUNDAY AND LIFTS OUT ON MONDAY...HIGH TEMPS WILL CREEP UPWARD WITH MOST OF THE CWA BACK IN THE LOWER TO MID 90S TUESDAY THROUGH FRIDAY. HAVE ADJUSTED OVERNIGHT LOWS DOWN 1-3 DEGREES...MAINLY RURAL AREAS...THURSDAY AND FRIDAY DUE TO DRIER AIR SPREADING INTO THE REGION. LOOKING AHEAD INTO NEXT WEEKEND AND THE LAST WEEK OF SEPTEMBER...BOTH THE GFS AND ECMWF MODELS ARE INDICATING A WEAKNESS ALOFT OVER THE SOUTHEAST OR SOUTHERN STATES AND THE UPPER RIDGE OFF TO OUR WEST. THIS PATTERN WOULD RESULT IN LOWER HEIGHTS ALOFT OVER NORTH AND CENTRAL TEXAS...AND THUS TEMPERATURES A LITTLE CLOSER TO NORMAL WITH HIGHS IN THE MID 80S TO LOWER 90S. 75 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 88 72 90 72 92 / 40 30 20 10 5 WACO, TX 93 70 95 71 93 / 20 10 10 5 5 PARIS, TX 87 67 87 66 87 / 30 20 30 30 20 DENTON, TX 87 69 89 68 91 / 40 40 20 20 5 MCKINNEY, TX 88 69 90 69 90 / 40 30 20 20 10 DALLAS, TX 89 73 90 71 92 / 40 30 20 10 5 TERRELL, TX 91 69 91 69 91 / 20 20 20 20 10 CORSICANA, TX 94 71 93 71 92 / 10 10 10 5 10 TEMPLE, TX 93 69 93 70 92 / 10 10 5 5 5 MINERAL WELLS, TX 87 67 90 68 91 / 40 40 20 10 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
641 AM CDT SAT SEP 19 2015 .AVIATION... LOW CLOUDS HAVE FILLED IN BEHIND LAST NIGHT/S FROPA AND THEY WILL LIKELY STICK AROUND THROUGH MUCH OF THE DAY TODAY. MVFR CIGS SHOULD BE THE RULE AT KLBB AND KPVW...THOUGH KCDS WILL BE MOSTLY IN LOW VFR TERRITORY. CIGS SHOULD GRADUALLY SCATTER/LIFT TO VFR BY LATE THIS AFTERNOON OR EARLY THIS EVENING AT ALL OF THE TERMINALS. IN ADDITION...AN ISOLATED SHOWER OR STORM COULD VISIT THE TERMINALS ALMOST ANY TIME OVER THE NEXT 24 HOURS...THOUGH OVERALL PROBABILITIES OF A DIRECT IMPACT ARE TOO LOW TO INCLUDE EXPLICITLY IN THE TAFS. BREEZY NORTHEASTERLY WIND THIS MORNING WILL GRADUALLY WEAKEN THIS AFTERNOON. && .PREV DISCUSSION... /ISSUED 335 AM CDT SAT SEP 19 2015/ SHORT TERM... THE MAIN THEME TODAY WILL BE MUCH COOLER WEATHER THANKS TO A COLD FRONT THAT MOVED THROUGH FRIDAY EVENING. THE COLD FRONT HAS ALREADY EXITED THE SOUTHERN ZONES AND IS FORECAST TO STALL OUT WELL TO OUR SOUTH NEAR I-10 THIS AFTERNOON. BEHIND THE FRONT...WE HAVE SEEN A LITTLE CONVECTION LINGER ACROSS THE ROLLING PLAINS EARLY THIS MORNING...WITH SOME ADDITIONAL CONVECTION TIED TO AN ELEVATED FRONTAL ZONE FROM THE CENTRAL TEXAS PANHANDLE INTO WESTERN OKLAHOMA. ALTHOUGH WE COULD SEE A FEW ELEVATED SHOWERS AND STORMS LINGER INTO THE DAY TODAY...THE MORE CERTAIN BET IS FOR WIDESPREAD LOW CLOUDS TO FILL IN ACROSS THE AREA. THESE STUBBORN CLOUDS ALONG WITH PERSISTENT NORTHEASTERLY BREEZES WILL PROVIDE A MUCH COOLER DAY TODAY. IN FACT HIGHS TODAY WILL BE SOME 25 TO 30 DEGREES COOLER THAN YESTERDAY...ONLY TOPPING OUT IN THE LOWER TO MIDDLE 70S AT MOST SPOTS. REGARDING PRECIPITATION CHANCES...IT IS TOUGH TO FIND ANY GOOD FORCING WITH THE SURFACE FRONT WELL TO THE SOUTH AND SURFACE RIDGING BUILDING IN...BUT WITH A RELATIVELY MOIST TROPOSPHERE IN PLACE IT WILL NOT TAKE MUCH EITHER...SO WE HAVE CONTINUED WITH SLIGHT CHANCE TO LOW CHANCE POPS TODAY /FAVORING THE SOUTHERN ZONES/. THE NWP SUPPORTS THIS TOO...WITH LIGHT QPF SMATTERED ABOUT THE CWA BUT NO CLEAR COHERENT SIGNAL. WE WILL THEN SEE AN UPTICK IN ISENTROPIC UPGLIDE TONIGHT AS A MODEST SOUTHERLY LLJ DEVELOPS. THIS COUPLED WITH A POSSIBLE EMBEDDED DISTURBANCE AND EVEN RICHER DEEP LAYER MOISTURE APPROACHING FROM THE SOUTHWEST COULD IMPROVE OUR RAIN CHANCES SOMEWHAT...THOUGH THE BEST FORCING MAY STAY SOUTH AND WEST OF THE CWA. THE NWP GUIDANCE IS NOT OVERWHELMING WITH REGARDS TO QPF PRODUCTION LOCALLY EITHER...LIMITING OVERALL CONFIDENCE IN RAIN CHANCES. GIVEN THIS WE HAVE CARRIED LOW CHANCE POPS FOR MOST OF THE FA TONIGHT. THE RELATIVELY MOIST AND MOSTLY CLOUDY CONDITIONS WILL HELP SECURE A MILD NIGHT WITH LOWS RANGING FROM THE UPPER 50S ACROSS THE SOUTHWEST TEXAS PANHANDLE TO MIDDLE 60S IN THE ROLLING PLAINS. LONG TERM... THE RETURN OF SOUTHERLY FLOW BRINGING WARMER TEMPS...LINGERING MOISTURE...AND A PASSING WEAK SHORTWAVE ARGUE FOR MAINTAINING A CHANCE OF RAIN ACROSS THE AREA ON SUNDAY. QPF SIGNALS IN THE GUIDANCE ARE PRETTY WEAK AND THERE IS SOME QUESTION REGARDING THE DEGREE OF INSTABILITY WITH SURFACE TEMPS REMAINING RELATIVELY COOL /80S/...SO WE`VE KEPT POPS IN THE 20 TO 30 PERCENT RANGE. THE UPPER WAVE MOVES OFF ON MONDAY WITH RIDGING BUILDING IN OVER NEW MEXICO AND WEST TEXAS. THIS WILL RESULT IN WARMER AND DRIER CONDITIONS WITH HIGHS BACK UP NEAR 90 FOR MONDAY AND TUESDAY. MEANWHILE...WE ARE STILL LOOKING FOR A PLUME OF SUB-TROPICAL MOISTURE TO SPREAD OVER THE DESERT SOUTHWEST DOWNSTREAM OF AN UPPER LOW APPROACHING THE SOUTHERN CALIFORNIA COAST. A SHORTWAVE EMBEDDED IN THIS PLUME SHOULD SPREAD SHOWER AND T-STORM ACTIVITY NEWD ACROSS NEW MEXICO...AND PERHAPS BRUSH OUR COUNTIES ALONG THE TX/NM STATE LINE LATE TUESDAY. THE UPPER LOW WEAKENS AND EJECTS NEWD ACROSS THE SRN ROCKIES AROUND MIDWEEK. THE GFS AND ECMWF CONTINUE TO DIFFER ON THE TRACK OF THE SYSTEM...WITH THE ECMWF SOMEWHAT DEEPER AND SLOWER THAN THE GFS. THE ECMWF SOLUTION MAY SUPPORT SOME RAIN CHANCES FOR PORTIONS OF THE AREA ON THURSDAY. A NARROW UPPER RIDGE WILL AMPLIFY FROM SW TO NE ACROSS THE REGION LATE WEEK IN RESPONSE TO A LARGE TROUGH MOVING ONTO THE WEST COAST. THIS SHOULD KEEP RAIN CHANCES LOW AND TEMPS ABOVE NORMAL THROUGH THE END OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 70 58 85 60 / 20 20 20 10 TULIA 70 58 83 60 / 20 20 20 20 PLAINVIEW 70 60 83 61 / 20 30 20 10 LEVELLAND 73 61 83 62 / 20 30 20 10 LUBBOCK 73 62 84 63 / 20 30 20 10 DENVER CITY 74 62 82 62 / 30 40 20 10 BROWNFIELD 74 62 83 63 / 30 30 20 10 CHILDRESS 74 63 85 66 / 20 30 30 20 SPUR 74 63 85 65 / 20 30 20 10 ASPERMONT 78 66 88 66 / 30 30 30 10 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/33/23
  [top] Area Forecast Discussion National Weather Service Midland/Odessa TX 639 AM CDT SAT SEP 19 2015 .DISCUSSION... && .AVIATION... Cold front moving through the area and storms beginning to develop over the Central Permian Basin. Expect storm coverage to increase... have TSRA in all TAFs. Low clouds moving south behind the front with low MVFR cigs. && .PREV DISCUSSION... /issued 423 AM CDT SAT SEP 19 2015/ DISCUSSION...As of 4:00 AM CDT Saturday...a brief respite from the heat this weekend. Sfc obs and KMAF radar is indc that a cold front is currently over the Central Permian Basin. A few small thunderstorms are popping up behind the front. There are also a few thunderstorms along the Rio Grande in Northwest Presidio County along the edge of a large MCS centered over portions of Sonora and Chihuahua Mexico. The HRRR and RAP13 hi-res models move the cold front slowly south this morning...stalling near or north of I-10 this aftn. With good low-level convergence and weak mid level impulses the hi-res models bring a good shot of convection along the I-20 corridor this morning...moving south this aftn. The main impacts from the thunderstorms will be locally heavy rain and gusty winds. With the rain potential and cloud cover it will be significantly cooler than yesterday...in fact today should be the coolest day this month. Have continued convective chances tonight with the front over the CWA. The cold front will retreat north/wash out on Sunday as a ridge builds back into the Southern Plains/Rockies. Temps will warm to near seasonal levels on Sunday with a slight chance of thunderstorms. A blocking pattern develops over the CONUS next week with a trough along both coasts and a ridge over the Central US. Shortwaves will ride over the ridge...occasionally flattening it slightly. The Davis Mtns...and even more so the Guadalupe Mtns will be on the eastern edge of any convective activity into mid week. Otherwise...the rest of the CWA will be dry. Even though the center of the H85 thermal ridge will be just west of the CWA expect temps next week to be 5-10 degrees above normal...with widespread low 90s and even a few mid 90s across the lower elevations. Widespread 80s are expected in the Mtns...with upper 80s along the extreme northern portions of the CWA. The latest GFS ensemble forecasts keeps West Texas/Southeast New Mexico dry with above normal temperatures through the end of September and into the first several days of October. Strobin && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
234 PM MDT SAT SEP 19 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 231 PM MDT SAT SEP 19 2015 A SHORTWAVE TROF WL BE MOVING ACRS THE AREA TONIGHT AND INTO EARLY SUN. THE NAM SHOWS SOME ISOLD PCPN DEVELOPING LATER TODAY OVER SOME OF THE MTNS AND THEN SPREADING EAST TONIGHT ACRS THE PLAINS. THE LATEST HRRR IS DRY THRU ABOUT 00Z AND THEN IT SHOWS SOME ISOLD PCPN DEVELOPING OVR THE ERN PLAINS WHICH THEN EXITS THE STATE AROUND 07Z. MEASURABLE PCPN CHANCES LOOK QUITE LOW TONIGHT SO WL KEEP POPS MINIMAL. OVER NIGHT LOW TEMPS TONIGHT WL BE IN THE 40S TO LOWER 50S ACRS THE PLAINS...WITH 30S TO LOWER 40S OVER THE HIGH VALLEYS. ALAMOSA AND SURROUNDING LOCATIONS SHOULD HAVE LOWS IN THE LOWER TO MID 30S. ON SUN AN UPR RIDGE WL START BUILDING BACK OVR THE AREA...BUT A WEAK SHORTWAVE WL BRUSH NE AND E CENTRAL CO IN THE AFTERNOON. AT THIS TIME IT LOOKS LIKE DRY WEATHER CAN BE EXPECTED ACRS THE FORECAST AREA ON SUN...WITH HIGH TEMPS BEING WARMER THAN TODAY AND AROUND 5 DEGREES ABOVE NORMAL. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 231 PM MDT SAT SEP 19 2015 ...DRY AND WARM THROUGH THE EXTENDED PERIOD... LOOKS LIKE THE DRY AND WARM WEATHER THAT HAS DEFINED SEPTEMBER IN SE CO IS HERE TO STAY...AT LEAST THROUGH THE END OF NEXT WEEK. MONDAY...SHOULD BE THE WARMEST DAY OF THE WEEK AS HIGH PRESSURE REMAINS OVER THE AREA AND SW FLOW INCREASES AHEAD OF THE NEXT SYSTEM. TEMPS COULD GET INTO THE LOWER 90S OVER PORTIONS OF THE SE PLAINS. POPS WILL REMAIN BASICALLY NIL...EVEN FOR THE MT AREAS. TUESDAY THROUGH WEDNESDAY...A SUBTROPICAL LOW PRESSURE SYSTEM WILL MOVE OUT OF THE BAJA REGION ON TUE AND INTO THE DESERT SW...IN A TRAJECTORY THAT WILL MOVE IT THROUGH NW CO ON WED. THE BULK OF THE MOISTURE LOOKS TO IMPACT THE SW MTS TUE AFTERNOON AND EVENING. IT LOOKS LIKE MOST OF THE QPF WILL FALL OVER AZ...SO FLASH FLOODING RISK SHOULD BE LESS...BUT WILL STILL HAVE TO WATCH FOR SOME LOCALIZED MODERATE-HEAVY RAIN. THE SYSTEM THEN SHEARS OUT OVER THE ROCKIES...LEAVING ONLY SPOTTY CONVECTION FOR THE ERN MTS AND PLAINS ON WED. TEMPS REMAIN IN THE 80S FOR THE PLAINS...OR ABOUT 5-10 DEGREES ABOVE AVERAGE. THURSDAY-FRIDAY...WILL SEE A SLIGHT FRONTAL PUSH ON THU BEHIND THE DEPARTING SYSTEM...BUT DUE TO ITS SW-NE TRAJECTORY WILL NOT SEE MUCH COLD AIR BEHIND THE TROUGH...SO TEMPS LIKELY TO REMAIN IN THE 70S AND 80S FOR THE END OF THE WEEK. WITH DRY QUASI-ZONAL FLOW BECOMING RE-ESTABLISHED OVER THE AREA...POPS WILL REMAIN LOW. NEXT CHANCE OF ANY SIGNIFICANT WX WILL NOT COME UNTIL AT LEAST NEXT SATURDAY...AS A PACNW SYSTEM STARTS TO ADVANCE EWD INTO THE ROCKIES. THE ECMWF IS A BIT SLOWER AND DEEPER WITH THIS SYSTEM...WHILE THE GFS DELIVERS ANOTHER QUICK SHOT OF PRECIP TO THE AREA LATE NEXT WEEKEND. ENSEMBLE SPREADS ARE NOT VERY WIDE...AND SHOW A GENERALLY WEAK SYSTEM FINALLY MOVING INTO THE AREA BY EARLY THE FOLLOWING WEEK. SO...NOT MUCH HOPE FOR ANY INTERESTING WEATHER THROUGH THE END OF SEPTEMBER...BUT IT WILL PROBABLY BE A GOOD TIME TO GET OUTSIDE PROJECTS DONE. ROSE && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 231 PM MDT SAT SEP 19 2015 VFR CONDITIONS ARE EXPECTED TONIGHT THROUGH SUNDAY AFTERNOON AS RELATIVELY DRY AIR REMAINS OVER THE AREA AND AN UPR RIDGE BUILDS INTO CO ON SUN. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...28 LONG TERM...ROSE AVIATION...28
AREA FORECAST DISCUSSION
NWS ALBANY NY
206 PM EDT SAT SEP 19 2015 .SYNOPSIS... A VERY WARM AIR MASS WILL PERSIST THROUGH THIS AFTERNOON WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT...BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... JUST SOME MINOR ADJUSTMENTS BASED ON THE TIMING OF ONSET OF SCATTERED SHOWERS. OTHERWISE CURRENT FORECAST GENERALLY IN LINE WITH CURRENT DATA AND TRENDS THROUGH THIS AFTERNOON. PREVIOUS DISCUSSION... ADDITIONAL CLOUDS INCREASE FROM THE WEST ASSOCIATED WITH A COLD FRONT APPROACHING FROM THE GREAT LAKES LATE IN THE DAY. ONE MORE WARM DAY IS EXPECTED...WITH SUNSHINE AND A SOUTHERLY FLOW RESULTING IN HIGH TEMPS IN THE UPPER 70S TO LOWER 80S. MOST OF THE AREA SHOULD REMAIN DRY THROUGH THE DAYLIGHT HOURS. HOWEVER...CHANCES FOR SHOWERS WILL START TO INCREASE FOR THE WESTERN ADIRONDACKS/MOHAWK VALLEY LATE IN THE DAY AS THE COLD FRONT MOVES INTO WESTERN NY. BASED ON TIMING FROM HRRR AND LOCAL HI-RES WRF...WILL ONLY MENTION 20-30 POPS FOR HERKIMER/HAMILTON COUNTIES THROUGH 6 PM TODAY. THE BULK OF THE SHOWERS WILL ARRIVE AFTER DARK. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SHOWERS WILL BE MOVING INTO WESTERN PORTIONS OF THE AREA EARLY THIS EVENING...PRECEDING A COLD FRONT PUSHING EASTWARD ACROSS NY STATE. MODELS INDICATING A NARROW RIBBON OF WEAK INSTABILITY JUST AHEAD OF THE FRONT...SO WILL MENTION ISOLATED THUNDER ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. SOME BRIEF GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE LINE OF SHOWERS/STORMS FOR THIS AREA...BUT THERE WILL NOT BE ENOUGH INSTABILITY TO SUSTAIN TALL ENOUGH UPDRAFTS TO PRODUCE STRONGER WINDS. MODELS INDICATE THE LINE OF SHOWERS WILL BE WEAKENING SOMEWHAT AS THEY MOVE EAST DURING THE LATE EVENING AND OVERNIGHT HOURS. SO WILL MAINLY MENTION CHANCE POPS FOR MUCH OF THE AREA WITH LIGHT QPF AMOUNTS. THE COLD FRONT AND ANY ASSOCIATED SHOWERS SHOULD CLEAR THE ENTIRE AREA BY DAYBREAK SUNDAY. WINDS WILL BECOME NORTHERLY BEHIND THE FRONT AND WILL BE NOTICEABLE ALONG WITH COOLER TEMPERATURES. HIGHS ARE ONLY EXPECTED TO BE IN THE 60S TO NEAR 70...WHICH IS NEAR NORMAL BUT MUCH COOLER THAN RECENT DAYS. CLOUDS WILL DECREASE THROUGHOUT THE DAY AS HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE AREA. HIGH PRESSURE WILL SETTLE IN OVER THE REGION SUNDAY NIGHT INTO MONDAY MORNING...RESULTING IN CLEAR SKIES AND LIGHT WINDS. THESE CONDITIONS WILL ALLOW FOR THE COOLEST OVERNIGHT TEMPERATURES WE HAVE SEEN IN THREE MONTHS. LOWS ARE FORECAST TO BE IN THE UPPER 30S TO MID 40S...WITH PATCHY FROST POSSIBLE FOR SOME AREAS NORTH AND EAST OF ALBANY. THE LAST DAY ALBANY OFFICIALLY HAD A TEMPERATURE IN THE 40S WAS BACK ON JUNE 20TH...WHICH WAS 49 DEGREES THAT MORNING. TRANQUIL WEATHER WILL PERSIST MONDAY AND MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN CONTROL. TEMPERATURES LOOK TO BE CLOSE TO NORMAL. MONDAY NIGHT WILL LIKELY NOT BE AS COLD AS THE PREVIOUS NIGHT DUE TO SOME POSSIBLE ADDED CLOUD COVER AND A SLIGHT EASTERLY BREEZE...AS THE CENTER OF THE HIGH PRESSURE SYSTEM RETREATS TOWARDS THE CANADIAN MARITIMES. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE LONG TERM PERIOD STARTS OUT DRY AND SEASONABLE AS A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM THE OHIO VALLEY NORTHEASTWARD INTO THE NORTHEASTERN US. A WEAK COLD FRONT IS EXPECTED TO DROP SOUTHEAST FROM SOUTHERN CANADA THROUGH THE NORTHEAST ON WEDNESDAY AND STALL ACROSS THE MIDDLE ATLANTIC REGION ON THURSDAY. AT THIS TIME EXPECT THE FRONTAL PASSAGE WILL BE DRY WITH MODEL GUIDANCE INDICATING LITTLE IF ANY MOISTURE WITH THE FRONTAL BOUNDARY. FRIDAY AT THIS POINT IS A DIFFICULT FORECAST AS THE MODELS DIVERGE ON WHETHER OR NOT MOISTURE FROM THE SOUTH LIFTS NORTH WITH THE FRONTAL BOUNDARY STALLED JUST TO OUR SOUTH. AT THIS TIME THE GFS LIFTS MOISTURE NORTHWARD ACROSS OUR REGION ON FRIDAY WHILE THE ECMWF IS DRY WITH HIGH PRESSURE REMAINING IN CONTROL OF OUR WEATHER. FOR NOW WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR FRIDAY. TEMPERATURES FOR THE LONG TERM PERIOD WILL BE SEASONABLE TO SLIGHTLY BELOW NORMAL. EXPECT HIGHS TUESDAY TO BE IN THE MID 60S TO MID 70S WITH HIGHS ON WEDNESDAY AND THURSDAY IN THE UPPER 60S TO MID 70S AND HIGHS ON FRIDAY IN THE 60S TO AROUND 70 ALTHOUGH IT COULD BE COOLER IF THE GFS IS CORRECT. LOWS WILL BE IN THE 40S TO LOWER 50S TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... DESPITE A COLD FRONT MOVING THROUGH THE REGION TONIGHT...EXPECT VFR CONDITIONS AT THE TAF SITES FOR MOST OF THE TAF PERIOD. SHOWERS ASSOCIATED WITH THE FRONT WILL BEGIN TO DIMINISH AFTER SUNSET...AND MAINLY LIGHT RAIN SHOWERS...IF ANY...ARE EXPECTED TO AFFECT THE TAF SITES BETWEEN 02Z AND 09Z. HAVE ONLY INCLUDED VCSH AT THE KALB/KPSF/KPOU TAF SITES...AND 6SM -SHRA T KGFL. OTHERWISE HAVE FORECAST ONLY VFR CONDITIONS AT THE TAF SITES. SOUTH TO SOUTHWEST WINDS FOR THE REST OF THE AFTN AND INTO THIS EVENING AT 8 TO 12 KTS...WITH GUSTS UP TO 20 KTS. THE WINDS WILL DECREASE SOMEWHAT AFTER SUNSET...BUT REMAIN STRONG ENOUGH TO PREVENT ANY FOG FORMATION TONIGHT. THE FRONT WILL MOVE THROUGH BETWEEN 05Z AND 09...WITH WINDS SHIFTING TO WESTERLY AND THEN NORTHWWEST TO NORTH AT 8 TO 10 KTS WITH GUSTS AORUND 15 KTS. OUTLOOK... SUN AFTN-WED: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. MINIMUM RELATIVE HUMIDITY VALUES TODAY WILL BE AROUND 45 TO 50 PERCENT...INCREASING TO MAXIMUM VALUES OF 85 TO 100 PERCENT TONIGHT. MIN RH VALUES ON SUNDAY ARE FORECAST TO BE BETWEEN 35 AND 45 PERCENT. WINDS TODAY WILL BE SOUTHERLY AROUND 10 TO 15 MPH...BECOMING NORTHWEST AT 5 TO 15 MPH TONIGHT AS A COLD FRONT PASSES THROUGH. WINDS ON SUNDAY WILL BECOME NORTHERLY AROUND 5 TO 15 MPH. && .HYDROLOGY... NO HYDROLOGIC CONCERNS THROUGH THE NEXT FIVE DAYS. DRY CONDITIONS WILL PERSIST THROUGH MUCH OF TODAY. A COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST TONIGHT WITH MAINLY SCATTERED SHOWERS EXPECTED. SHOWERS WILL BE MORE NUMEROUS ACROSS THE WESTERN ADIRONDACKS WHERE ONE QUARTER TO ONE THIRD OF AN INCH OF RAINFALL IS POSSIBLE. ELSEWHERE GENERALLY A TENTH OF AN INCH OR LESS IS EXPECTED. THE RAINFALL WILL HAVE LITTLE...IF ANY IMPACT ON AREA RIVERS. DRY CONDITIONS RETURN FOR SUNDAY AND WILL LIKELY LAST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH ANOTHER AREA OF HIGH PRESSURE BUILDING IN. RIVER FLOWS WILL CONTINUE TO RECEDE INTO NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...NAS/JPV SHORT TERM...JPV LONG TERM...11 AVIATION...GJM FIRE WEATHER...JPV HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS TAUNTON MA
141 PM EDT SAT SEP 19 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL TODAY...WITH A COLD FRONT BRINGING JUST A FEW SHOWERS LATE TONIGHT INTO EARLY SUNDAY. HIGH PRESSURE THEN BUILDS INTO NORTHERN NEW ENGLAND FOR MUCH OF NEXT WEEK. LOW PRESSURE WELL OFFSHORE TO THE SOUTH MAY BRING SHOWERS CLOSE TO THE ISLANDS TUESDAY...OTHERWISE DRY WEATHER THROUGH THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM UPDATE... ALLOWED THE DENSE FOG ADVISORY TO EXPIRE NATURALLY AS MOST LOCATIONS HAD LIFTED TO AT LEAST 0.5 MILES OR HIGHER. STILL SOME AREAS WHERE FOG IS HANGING IN...BUT VSBYS ALL SHOWING SIGNS OF RISING. OTHERWISE...FORECAST REQUIRED A BIT MORE MANUAL ADJUSTMENT THIS MORNING AS THE STRATUS DEC CONTINUES TO HOLD FAST AS OF 1O AM. SKIES WERE THE FIRST THING THAT NEEDED ADJUSTING. HOWEVER...THIS IS ALSO IMPACTING THE TEMPS...AND ARE LIKELY TO IMPACT THE HIGHS THIS AFTERNOON. GUIDANCE...EVEN IN THE SHORT TERM ARE NOT REALLY HANDLING THIS WELL. SO STARTED WITH A BASELINE OF 2M HRRR TEMPS COMBINED WITH OUR IN-HOUSE BIAS CORRECTED MAV. THIS PRESENTED A GOOD FOUNDATION BUT THEN MADE MANUAL EDITS FROM THERE BASED ON THE TIMING OF CLOUD COVER CLEARING. THE OVERALL FINAL NUMBERS ARE A BIT LOWER THAN PREVIOUS. PREVIOUS DISCUSSION... AFTER ANY EARLY MORNING FOG BURNS OFF...EXPECTING ANOTHER MOSTLY SUNNY...WARM DAY BEFORE A COLD FRONT MOVES THROUGH TONIGHT. HIGH TEMPERATURES ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S MOST LOCATIONS. SLIGHTLY COOLER TEMPERATURES EXPECTED ALONG THE SOUTH COAST WITH AN ONSHORE WIND. INCREASING DEWPOINTS WILL LEAD TO A MORE HUMID FEELING TO THE DAY...BUT IT SHOULD NOT FEEL OPPRESSIVE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... TONIGHT...LOW PRESSURE MOVES THROUGH QUEBEC BRINGING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND. THERE IS ENOUGH MOISTURE AVAILABLE... AS INDICATED BY K INDICES...FOR SHOWERS TO DEVELOP. INSTABILITY AND MID LEVEL LAPSE RATES ARE LACKING SO NO THUNDER IS EXPECTED. NOT EXPECTING WIDESPREAD RAIN OVERNIGHT BUT SOME LOCATIONS WILL LIKELY HAVE A SHOWER OR TWO. DESPITE ABOVE NORMAL PWAT VALUES...RAINFALL AMOUNTS WILL BE LESS THAN A QUARTER INCH. NOT ENOUGH TO MAKE MUCH OF A DIFFERENCE IN THE RAINFALL DEFICIT. INCREASING CLOUDS...CHANCE OF SHOWERS...AND INCREASED DEWPOINTS... WILL COMBINE TO KEEP OVERNIGHT TEMPERATURES A BIT WARMER THAN PREVIOUS NIGHTS. THE ONLY EXCEPTION TO THIS MAY BE IN NORTHWESTERN MASSACHUSETTS WHERE COLD ADVECTION BEHIND THE FRONT MAY BEGIN BY THE EARLY MORNING HOURS. SUNDAY...MOST PRECIP SHOULD HAVE COME TO AN END BY SUNRISE SUNDAY MORNING. THERE IS A LOW PROBABILITY THAT A FEW SHOWERS MAY LINGER ON THE CAPE AND ISLANDS EARLY BEFORE THE FRONT PUSHES OFFSHORE. HIGH PRESSURE BUILDS INTO NORTHERN NEW ENGLAND BRINGING DRY WEATHER TO THE REGION. EXPECT STRONG COLD ADVECTION TO HOLD OFF UNTIL AFTER SUNSET SUNDAY SO MUCH OF THE DAY WILL BE PLEASANT WITH SUNNY SKIES AND MORE SEASONABLE TEMPERATURES. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... BIG PICTURE... UPPER TROUGH OVER THE GULF OF ALASKA WITH NEAR-ZONAL FLOW ACROSS THE PACIFIC NORTHWEST AND CANADA. SOUTHERN NEW ENGLAND REMAINS SOUTH OF THIS NORTHERN JET THROUGH THE FORECAST PERIOD. SOUTHERN STREAM UPPER LOW LOITERS OVER THE SOUTHEAST USA THROUGH THE WEEK. THE GFS EJECTS THIS LOW TOWARD NEW ENGLAND AT THE END OF THE WEEK WHILE THE ECMWF MOVES IT SOUTHWEST TOWARD THE GULF OF MEXICO. THE LARGE SCALE PATTERN IS DRY AND WARM WITH 500 MB CONTOURS MOSTLY ABOVE NORMAL. HOWEVER A LOW LEVEL EAST/NORTHEAST FLOW WOULD BUFFER SURFACE TEMPS SEVERAL DEGREES...CLOSER TO NORMAL OR A LITTLE BELOW. THE DAILIES... SUNDAY NIGHT-MONDAY... HIGH PRESSURE BUILDS OVER NORTHERN NEW ENGLAND WITH SHORTWAVE RIDGE ALOFT. THIS SHOULD PROVIDE GENERAL SUBSIDENCE. POSITIONING OF THE HIGH CENTER WILL BRING A NORTHEAST FLOW ACROSS SOUTHERN NEW ENGLAND...STRONGEST NEAR THE EAST MASSACHUSETTS SHORE. THIS SUGGESTS MOSTLY CLEAR SKIES WITH LIGHT WIND INLAND AND A BUFFERING EAST/NORTHEAST WIND FLOW NEAR THE EASTERN SHORE. RADIATIONAL COOLING SUNDAY NIGHT SHOULD BRING SFC TEMPS TO NEAR THE DEW POINT. INLAND DEWS WILL BE IN THE UPPER 30S TO LOWER 40S...COASTAL DEWS IN THE MID 40S TO LOWER 50S. EAST FLOW WILL LIMIT MIXING DEPTHS...BASED ON TEMPS AT 900 MB THIS WOULD SUPPORT MONDAY MAX TEMPS IN THE MID AND UPPER 60S NEAR THE SHORE AND LOWER 70S INLAND. TUESDAY THROUGH THURSDAY... HIGH PRESSURE IN CONTROL MUCH OF THE TIME OVER NEW ENGLAND. A WEAK SHORTWAVE MOVES THROUGH THE REGION WEDNESDAY WITH VERY LIMITED MOISTURE NOTED ON THE MODELS. MAYBE ENOUGH FOR A PERIOD OF CLOUDS...BUT NO PCPN. FRIDAY...THE ECMWF BUILDS CANADIAN HIGH PRESSURE OVER THE REGION WITH A NORTHWEST UPPER FLOW. THE GFS IS MORE SHALLOW WITH A SHORTWAVE OVER QUEBEC FRIDAY AND FRIDAY NIGHT...ALSO FARTHER NORTH WITH SOUTHERN STREAM UPPER LOW MOVING THROUGH CAROLINAS INTO DELMARVA AREA. THIS BRINGS SHOWERS FARTHER NORTH ON FRIDAY AS WELL AS THE LEFT FRONT QUADRANT OF ASSOCIATED UPPER JET. THE ECMWF SCENARIO IS FOR DRY WEATHER. THE GFS SCENARIO WOULD SUGGEST A CHANCE OF SHOWERS ON FRIDAY...BUT ITS SUDDEN APPEARANCE ON THIS RUN AND IN THE FINAL PERIOD OF THE FORECAST DOES NOT GENERATE A LOT OF CONFIDENCE. WE WILL GO WITH THE DRY ECMWF SCENARIO. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SUNDAY NIGHT/... THROUGH 02Z TONIGHT...HIGH CONFIDENCE. MAINLY VFR WITH SSW FLOW 5-10 KT. AFTER 02Z TONIGHT TO ABOUT 10Z TOMORROW MORNING...MODERATE CONFIDENCE. EXPECT SIMILAR CONDITIONS TO LAST NIGHT WITH LOW CLOUDS AND FOG BUILDING FROM THE S COAST INLAND THROUGH THE OVERNIGHT HOURS. TIMING MAY BE OFF SOMEWHAT IN THE TAFS. THE PRIMARY DIFFERENCE WILL BE THE RISK FOR SHWRS WHICH MAY SCOUR THINGS OUT TO MAINLY MVFR ESPECIALLY NW OF A HFD-ORH-BVY LINE...AREAS SE MAY REMAIN IFR/LIFR AT TIMES. 10Z TOMORROW MORNING THROUGH SUNDAY NIGHT...HIGH CONFIDENCE. EXPECT IMPROVEMENT AS THE COLD FRONT MOVES THROUGH AND WINDS SHIFT TO THE NW /PICKING UP WITH GUSTS 10-15 KT/. MAINLY VFR ALL TERMINALS BY MID DAY...REMAINING VFR INTO SUN NIGHT. KBOS TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY WITH TIMING AND PERSISTENCE OF LATE NIGHT IFR CONDITIONS. KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY WITH TIMING AND PERSISTENCE OF LATE NIGHT IFR CONDITIONS. OUTLOOK...MONDAY THROUGH THURSDAY...MODERATE TO HIGH CONFIDENCE. VFR THROUGH THE PERIOD. NORTHEAST TO EAST WINDS ARE EXPECTED MONDAY WITH GUSTS 20 TO 25 KNOTS MAINLY ACROSS CAPE COD AND ISLANDS. EAST TO NORTHEAST FLOW CONTINUES THROUGH MIDWEEK WITH LIGHTER WINDS IN THE INTERIOR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SUNDAY/...HIGH CONFIDENCE. FOG MAY LIMIT VISIBILITIES THIS MORNING...BUT SHOULD THIN DURING THE MORNING HOURS. THEN HIGH PRESSURE OVER THE WATERS WILL BRING LIGHT WINDS AND CALM SEAS THROUGH SUNDAY MORNING. WINDS AND SEAS BUILD SUNDAY AFTERNOON AS A COLD FRONT CROSSES THE WATERS. SCA CONDITIONS MAY OCCUR BY SUNDAY EVENING. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE. HIGH PRESSURE BUILDS OVER NORTHERN NEW ENGLAND WITH EAST TO NORTHEAST WINDS ACROSS THE MASS AND RI COASTAL WATERS. LOW LEVEL FLOW SUPPORTS WINDS 20 TO 25 KNOTS SUNDAY NIGHT AND MONDAY THEN DIMINISHING. THESE WINDS WILL MAINTAIN 5 TO 7 FOOT SEAS ON THE OUTER WATERS AND MASS BAY...POSSIBLY CAPE COD BAY. WINDS DIMINISH THROUGH MIDWEEK WHILE SEAS SUBSIDE VERY SLOWLY. SMALL CRAFT ADVISORY CONTINUES THROUGH AT LEAST MONDAY...AND POSSIBLY LINGERING SMALL CRAFTS FOR SEAS ON THE OUTER WATERS THROUGH MIDWEEK. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...WTB/RLG NEAR TERM...DOODY/RLG SHORT TERM...RLG LONG TERM...WTB AVIATION...WTB/DOODY MARINE...WTB/RLG
AREA FORECAST DISCUSSION
NWS ALBANY NY
105 PM EDT SAT SEP 19 2015 .SYNOPSIS... A VERY WARM AIR MASS WILL PERSIST THROUGH THIS AFTERNOON WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT...BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... JUST SOME MINOR ADJUSTMENTS BASED ON THE TIMING OF ONSET OF SCATTERED SHOWERS. OTHERWISE CURRENT FORECAST GENERALLY IN LINE WITH CURRENT DATA AND TRENDS THROUGH THIS AFTERNOON. PREVIOUS DISCUSSION... ADDITIONAL CLOUDS INCREASE FROM THE WEST ASSOCIATED WITH A COLD FRONT APPROACHING FROM THE GREAT LAKES LATE IN THE DAY. ONE MORE WARM DAY IS EXPECTED...WITH SUNSHINE AND A SOUTHERLY FLOW RESULTING IN HIGH TEMPS IN THE UPPER 70S TO LOWER 80S. MOST OF THE AREA SHOULD REMAIN DRY THROUGH THE DAYLIGHT HOURS. HOWEVER...CHANCES FOR SHOWERS WILL START TO INCREASE FOR THE WESTERN ADIRONDACKS/MOHAWK VALLEY LATE IN THE DAY AS THE COLD FRONT MOVES INTO WESTERN NY. BASED ON TIMING FROM HRRR AND LOCAL HI-RES WRF...WILL ONLY MENTION 20-30 POPS FOR HERKIMER/HAMILTON COUNTIES THROUGH 6 PM TODAY. THE BULK OF THE SHOWERS WILL ARRIVE AFTER DARK. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... SHOWERS WILL BE MOVING INTO WESTERN PORTIONS OF THE AREA EARLY THIS EVENING...PRECEDING A COLD FRONT PUSHING EASTWARD ACROSS NY STATE. MODELS INDICATING A NARROW RIBBON OF WEAK INSTABILITY JUST AHEAD OF THE FRONT...SO WILL MENTION ISOLATED THUNDER ACROSS PORTIONS OF THE WESTERN ADIRONDACKS. SOME BRIEF GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE LINE OF SHOWERS/STORMS FOR THIS AREA...BUT THERE WILL NOT BE ENOUGH INSTABILITY TO SUSTAIN TALL ENOUGH UPDRAFTS TO PRODUCE STRONGER WINDS. MODELS INDICATE THE LINE OF SHOWERS WILL BE WEAKENING SOMEWHAT AS THEY MOVE EAST DURING THE LATE EVENING AND OVERNIGHT HOURS. SO WILL MAINLY MENTION CHANCE POPS FOR MUCH OF THE AREA WITH LIGHT QPF AMOUNTS. THE COLD FRONT AND ANY ASSOCIATED SHOWERS SHOULD CLEAR THE ENTIRE AREA BY DAYBREAK SUNDAY. WINDS WILL BECOME NORTHERLY BEHIND THE FRONT AND WILL BE NOTICEABLE ALONG WITH COOLER TEMPERATURES. HIGHS ARE ONLY EXPECTED TO BE IN THE 60S TO NEAR 70...WHICH IS NEAR NORMAL BUT MUCH COOLER THAN RECENT DAYS. CLOUDS WILL DECREASE THROUGHOUT THE DAY AS HIGH PRESSURE BUILDS SOUTHWARD ACROSS THE AREA. HIGH PRESSURE WILL SETTLE IN OVER THE REGION SUNDAY NIGHT INTO MONDAY MORNING...RESULTING IN CLEAR SKIES AND LIGHT WINDS. THESE CONDITIONS WILL ALLOW FOR THE COOLEST OVERNIGHT TEMPERATURES WE HAVE SEEN IN THREE MONTHS. LOWS ARE FORECAST TO BE IN THE UPPER 30S TO MID 40S...WITH PATCHY FROST POSSIBLE FOR SOME AREAS NORTH AND EAST OF ALBANY. THE LAST DAY ALBANY OFFICIALLY HAD A TEMPERATURE IN THE 40S WAS BACK ON JUNE 20TH...WHICH WAS 49 DEGREES THAT MORNING. TRANQUIL WEATHER WILL PERSIST MONDAY AND MONDAY NIGHT...WITH HIGH PRESSURE REMAINING IN CONTROL. TEMPERATURES LOOK TO BE CLOSE TO NORMAL. MONDAY NIGHT WILL LIKELY NOT BE AS COLD AS THE PREVIOUS NIGHT DUE TO SOME POSSIBLE ADDED CLOUD COVER AND A SLIGHT EASTERLY BREEZE...AS THE CENTER OF THE HIGH PRESSURE SYSTEM RETREATS TOWARDS THE CANADIAN MARITIMES. && .LONG TERM /TUESDAY THROUGH FRIDAY/... THE LONG TERM PERIOD STARTS OUT DRY AND SEASONABLE AS A LARGE RIDGE OF HIGH PRESSURE EXTENDS FROM THE OHIO VALLEY NORTHEASTWARD INTO THE NORTHEASTERN US. A WEAK COLD FRONT IS EXPECTED TO DROP SOUTHEAST FROM SOUTHERN CANADA THROUGH THE NORTHEAST ON WEDNESDAY AND STALL ACROSS THE MIDDLE ATLANTIC REGION ON THURSDAY. AT THIS TIME EXPECT THE FRONTAL PASSAGE WILL BE DRY WITH MODEL GUIDANCE INDICATING LITTLE IF ANY MOISTURE WITH THE FRONTAL BOUNDARY. FRIDAY AT THIS POINT IS A DIFFICULT FORECAST AS THE MODELS DIVERGE ON WHETHER OR NOT MOISTURE FROM THE SOUTH LIFTS NORTH WITH THE FRONTAL BOUNDARY STALLED JUST TO OUR SOUTH. AT THIS TIME THE GFS LIFTS MOISTURE NORTHWARD ACROSS OUR REGION ON FRIDAY WHILE THE ECMWF IS DRY WITH HIGH PRESSURE REMAINING IN CONTROL OF OUR WEATHER. FOR NOW WILL PLACE SLIGHT CHANCE POPS IN THE GRIDS FOR FRIDAY. TEMPERATURES FOR THE LONG TERM PERIOD WILL BE SEASONABLE TO SLIGHTLY BELOW NORMAL. EXPECT HIGHS TUESDAY TO BE IN THE MID 60S TO MID 70S WITH HIGHS ON WEDNESDAY AND THURSDAY IN THE UPPER 60S TO MID 70S AND HIGHS ON FRIDAY IN THE 60S TO AROUND 70 ALTHOUGH IT COULD BE COOLER IF THE GFS IS CORRECT. LOWS WILL BE IN THE 40S TO LOWER 50S TUESDAY NIGHT THROUGH THURSDAY NIGHT. && .AVIATION /17Z SATURDAY THROUGH WEDNESDAY/... FOR TODAY EXPECTING SOME HIGH CLOUDS TO STREAM IN AND EVENTUALLY MID CLOUDS THIS AFTERNOON TO MOVE IN AHEAD AN APPROACHING COLD FRONT. THIS BOUNDARY WILL USHER A MUCH COOLER AND MORE SEASONABLE AIR MASS INTO THE REGION WITH ITS PASSAGE TONIGHT. HAVE INCLUDED -SHRA FOR KGFL AFTER 03Z AND VCSH FOR KALB...KPSF AND KPOU BTWN 03Z AND 05Z AS SHOWERS WILL BE DIMINISHING IN COVERAGE AS THEY MOVE SOUTH AND EAST. CIGS WILL ALSO LOWER TO OVC035-050 BTWN 03Z AND 05Z. SKIES WILL THEN BECOME SCT035-045 LATE TONIGHT IN THE WAKE OF THE COLD FRONT. CALM WINDS WILL BECOME SOUTHERLY TODAY AS THE FLOW WILL PICK UP DURING THE DAY TO 8 TO 12 KNOTS WITH SOME 15-22 KTS EXPECTED AT KGFL...KPSF AND ESPECIALLY KALB DURING THE AFTERNOON. WINDS WILL REMAIN BTWN 08-12 KTS THIS EVENING BEFORE SHIFTING TO THE WEST- NORTHWEST WITH THE FRONTAL PASSAGE LATE TONIGHT. OUTLOOK... SUN-WED: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A VERY WARM AIR MASS WILL PERSIST THROUGH TODAY WITH HIGH PRESSURE ALONG THE EAST COAST. HOWEVER...A COLD FRONT APPROACHING FROM THE GREAT LAKES WILL CROSS OUR REGION TONIGHT BRINGING SOME SHOWERS AND USHERING IN A COOLER AND MORE SEASONABLE AIR MASS FOR SUNDAY INTO EARLY NEXT WEEK. MINIMUM RELATIVE HUMIDITY VALUES TODAY WILL BE AROUND 45 TO 50 PERCENT...INCREASING TO MAXIMUM VALUES OF 85 TO 100 PERCENT TONIGHT. MIN RH VALUES ON SUNDAY ARE FORECAST TO BE BETWEEN 35 AND 45 PERCENT. WINDS TODAY WILL BE SOUTHERLY AROUND 10 TO 15 MPH...BECOMING NORTHWEST AT 5 TO 15 MPH TONIGHT AS A COLD FRONT PASSES THROUGH. WINDS ON SUNDAY WILL BECOME NORTHERLY AROUND 5 TO 15 MPH. && .HYDROLOGY... NO HYDROLOGIC CONCERNS THROUGH THE NEXT FIVE DAYS. DRY CONDITIONS WILL PERSIST THROUGH MUCH OF TODAY. A COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST TONIGHT WITH MAINLY SCATTERED SHOWERS EXPECTED. SHOWERS WILL BE MORE NUMEROUS ACROSS THE WESTERN ADIRONDACKS WHERE ONE QUARTER TO ONE THIRD OF AN INCH OF RAINFALL IS POSSIBLE. ELSEWHERE GENERALLY A TENTH OF AN INCH OR LESS IS EXPECTED. THE RAINFALL WILL HAVE LITTLE...IF ANY IMPACT ON AREA RIVERS. DRY CONDITIONS RETURN FOR SUNDAY AND WILL LIKELY LAST THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WITH ANOTHER AREA OF HIGH PRESSURE BUILDING IN. RIVER FLOWS WILL CONTINUE TO RECEDE INTO NEXT WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...JPV NEAR TERM...NAS/JPV SHORT TERM...JPV LONG TERM...11 AVIATION...GJM FIRE WEATHER...JPV HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS MIAMI FL
324 PM EDT SAT SEP 19 2015 .DISCUSSION... A RARE, QUIET RADAR FOR A SUMMER AFTERNOON HERE IN SOUTH FL. THE MORNING MIAMI SOUNDING SHOWS A CAP AT AROUND H85...AND CONVECTION SURE IS STRUGGLING TO GET GOING. A MAJOR FACTOR IS LACK OF CONVERGENCE WITH A WEST-NORTHWEST WIND NEAR 10 MPH EVERYWHERE AND NO ATLANTIC SEA BREEZE FORMING. HRRR SHOWS AN ATLANTIC SEA BREEZE DEVELOPING BY 5 PM...BUT THAT IS QUESTIONABLE. GOES SOUNDER PW FIELDS SHOW DRIER AIR OVER THE GULF MOVING IN AS WELL. GIVEN ALL OF THESE FACTORS...HAVE KEPT POPS ON THE LOW SIDE THROUGH THE REMAINDER OF THE DAY-EVENING. DRIER AIR WILL CONTINUE TO MOVE INTO THE AREA SUNDAY THROUGH MONDAY WITH A MEAN WIND FLOW OUT OF THE W-NW WHILE SURFACE WINDS OUT OF THE W-NW EVENTUALLY BECOME NORTHEAST-EAST AS SURFACE HIGH MOVES IN FROM THE NORTH. ISOLATED-SCATTERED MAINLY AFTERNOON/EVENING TSTORMS ARE FORECAST WITH FOCUS OVER THE INTERIOR AND EAST COAST ON SUNDAY AND SOUTHERN INTERIOR SECTIONS ON MONDAY. BY MID NEXT WEEK A MID LEVEL LOW IS STILL SHOWN BY THE GLOBAL MODELS TO DEVELOP AND CUT OFF THEN RETROGRADE OVER THE SOUTHEAST U.S. LATE IN THE WEEK...BUT THE PLACEMENT OF THIS CUT OFF LOW HAS BEEN CHANGING AND THIS HAS IMPLICATIONS ON JUST HOW WET AND STORMY IT GETS HERE MID-LATE NEXT WEEK. POPS WILL CONTINUE TO SHOW AN INCREASING TREND DURING THIS PERIOD AS EVEN THE LESS AGGRESSIVE MODEL RUNS STILL SHOW MORE STORMINESS AND INCREASING MOISTURE FROM THE SOUTH. /GREGORIA && .MARINE... NO CONCERNS AS WINDS LIGHTEN AND SEAS REMAIN GENERALLY LESS THAN 4 FT. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 76 90 76 89 / 30 30 30 20 FORT LAUDERDALE 77 90 78 89 / 30 40 40 30 MIAMI 77 92 78 90 / 20 50 30 40 NAPLES 77 90 76 91 / 20 20 10 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MIAMI FL
145 PM EDT SAT SEP 19 2015 .AVIATION... DRIER AIR IS MOVING INTO THE AREA. THIS HAS SEVERELY LIMITED CONVECTIVE DEVELOPMENT TODAY. THERE STILL MAY BE SOME ISOLATED ACTIVITY LATE THIS AFTERNOON AND THIS EVENING, BUT EXPECT IT TO BE ISOLATED AT BEST. IT MAY NOT DEVELOP AT ALL. GIVEN THIS, REMOVED ANY MENTION OF CONVECTION. SO, VFR EXPECTED THROUGH THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 1123 AM EDT SAT SEP 19 2015/ UPDATE... UPDATED POPS ONCE AGAIN, LEAVING ONLY THE COASTAL AREAS UNDER A CHANCE, WITH THE OTHER AREAS DROPPED TO A SLIGHT CHANCE. THIS IS SUPPORTED BY BOTH THE LACK OF ACTIVITY OVER THE INTERIOR, THE FAIRLY CLEAR SKIES FOR THE LATE MORNING, AND THE HRRR, WHICH ONLY DEVELOPS A SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON INTO THE EVENING HOURS. PREV DISCUSSION... /ISSUED 1037 AM EDT SAT SEP 19 2015/ UPDATE... MUCH DIFFERENT MORNING THAN YESTERDAY MORNING. VERY LITTLE ACTIVITY ON RADAR. WITH ALL THE ACTIVITY OVER THE COASTAL WATERS AT THIS TIME. THE HRRR KEEPS THE WEATHER FAIRLY QUIET ACROSS THE CWA THROUGH THE AFTERNOON HOURS, WITH SOME ISOLATED TO SCATTERED CONVECTION THIS AFTERNOON. ONLY REAL CHANGES ARE TO SKY COVER AND TO ADJUST WIND TO INCLUDE MORE CURRENT MODEL RUNS, ALSO REDUCE POPS IN THE WESTERN PORTION OF THE CWA, GIVEN THE CURRENT RUN OF THE HRRR. OTHERWISE, THE FORECAST IS PROGRESSING FAIRLY WELL. PREV DISCUSSION... /ISSUED 340 AM EDT SAT SEP 19 2015/ DISCUSSION... TODAY-TONIGHT...SURFACE LOW CONTINUES TO SLOWLY DEEPEN OFF THE FL/GA COAST THIS MORNING WHILE RADAR AND SATELLITE SHOW THE WEAKER GULF LOW HAS BEEN ABSORBED INTO THE LARGER CIRCULATION. THE MID- UPPER LEVEL TROUGH THAT`S BEEN OVER THE STATE WILL ALSO BEGIN LIFTING OUT TO THE NORTHEAST...THOUGH THE AXIS WILL GET SHIFTED FURTHER SOUTH INTO S FLORIDA AS A RESULTING BRINGING COOLER MID LEVEL TEMPS. WAVER VAPOR SATELLITE IS SHOWING THE DEEPER MOISTURE BEING LIFTED OUT WITH SOME MID LEVEL DRYING ACROSS NORTH AND CENTRAL FLORIDA THAT MODELS BRING INTO SOUTH FLORIDA INTO THE AFTERNOON. STEERING FLOW HAS PICKED UP OUT OF THE SW WITH THE CURRENT SHOWERS AND STORMS OVER THE WATERS THIS MORNING MOVING AT AROUND 20KTS. LITTLE CHANGE IN THIS SPEED THROUGH THE DAY SO WE WILL SEE FAIRLY QUICK MOVING SHOWERS AND STORMS INTO THE AFTERNOON. ACTIVITY WILL ONCE AGAIN FAVOR EAST COAST...WITH MODELS FOCUSING MORE TOWARDS BROWARD /MIAMI-DADE WHERE TRAILING SURFACE TROUGH LIES. GIVEN STORM MOTION...DON`T EXPECT HEAVY RAIN TO BE AS SIGNIFICANT A CONCERN BUT WILL HAVE TO WATCH FOR SOME TRAINING IN SPOTS GIVEN THE ALREADY SATURATED GROUND. OVERALL COVERAGE IS ALSO EXPECTED TO BE LOWER THAN THE PAST FEW DAYS. ACTIVITY SHOULD BE FAIRLY QUICK TO PUSH OFFSHORE THIS EVENING WITH ACTIVITY JUST OVER THE WATERS OVERNIGHT. SUNDAY...MID-UPPER LEVEL TROUGH CONTINUES TO WEAKEN AND LIFT OFF TO THE NORTHEAST INTO SUNDAY...TAKING WITH IT THE DEEPENING SURFACE LOW OFFSHORE THE CAROLINA COAST. TRAILING EDGE OF THE TROUGH LINGERS OVER S FLORIDA WITH CONTINUING DEEP AND BRISK WEST-SOUTHWESTERLY FLOW. DRIER AIR BEGINS TO WORK FURTHER DOWN THE PENINSULA IN THE CYCLONIC FLOW AROUND THE BACK SIDE OF THE DISTANT LOW...PUSHING THE DEEPER TROPICAL MOISTURE SOUTH OF THE STATE. RAIN CHANCES ACROSS THE REGION DIMINISH CONSIDERABLY...STILL FAVORING THE EAST COAST AND FAR SOUTH PENINSULA IN FAST MOVING SHOWERS AND A FEW STORMS. LONG TERM (MONDAY-FRIDAY)...SURFACE LOW CONTINUES TO LIFT FURTHER OFF TO THE NORTHEAST EARLY NEXT WEEK LEAVING A WEAK PRESSURE GRADIENT IN PLACE ACROSS THE STATE WITH DAILY SEA BREEZES BECOMING THE MAIN DRIVER OF AFTERNOON CONVECTION. MODELS REMAIN CONSISTENT IN SHOWING FAIRLY DECENT MID LEVEL DRY AIR WRAPPING AROUND THE BACK OF THE LOW INTO THE STATE MON-WED WHICH LOOKS TO KEEP RAIN CHANCES A LITTLE BELOW NORMAL AT 20-30 PERCENT...INCREASING TO 30-40 PERCENT ON WED WITH SOME MOISTURE ADVECTION AHEAD OF THE NEXT TROUGH. WEST- SOUTHWESTERLY STEERING COMPONENT REMAINS IN PLACE ON MONDAY...KEEPING THE BEST (THOUGH MUCH LOWER) RAIN CHANCES TOWARDS THE EAST COAST...BEFORE BECOMING LIGHT AND VARIABLE INTO MID WEEK WITH MORE ACTIVITY OVER THE INTERIOR. MID TO LATE WEEK MODELS SHOW THE NEXT TROUGH MOVING INTO THE EASTERN US CUTTING OFF OVER THE SOUTHEAST...A LITTLE FARTHER NORTH THAN YESTERDAY`S RUNS. 19/00Z GFS LIFTS THE LOW OUT INTO THE MID-ATLANTIC FAIRLY QUICKLY WHILE THE ECMWF STILL HAS IT RETROGRADING BACK TO THE GULF. WITH THE GFS`S MORE PROGRESSIVE SOLUTION...FLOW REMAINS MORE SOUTHWEST THAN SOUTH AND DEEP MOISTURE ADVECTION IS NOT QUITE AS PRONOUNCED ACROSS S FL. NONETHELESS...WE ARE LOOKING AT A RETURN TO A STORMY PATTERN TOWARDS THE END OF NEXT WEEK. MARINE...MODERATE SW WINDS OVER THE ATLANTIC TODAY 10-15KTS AS SURFACE LOW OFF THE GA/FL COAST DEEPENS AND SLOWLY MOVES OFF TO THE NE. WEST-NW WINDS 10KTS OVER THE GULF WATERS. PRESSURE GRADIENT COLLAPSES ON SUN RESULTING IN LIGHT WEST-NW WINDS 5-10KTS...VEERING N-NE MON AND TUES THEN EAST ON WED. SEAS GENERALLY 2FT OR LESS...WITH UP TO 3FT IN THE GULF STREAM THIS AFTERNOON AND 4FT TUES- THURS WITH SOME INCOMING SWELL AND NORTH FETCH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 75 91 77 88 / 20 30 20 20 FORT LAUDERDALE 77 90 78 88 / 20 40 30 30 MIAMI 77 91 78 90 / 20 40 30 40 NAPLES 76 90 75 92 / 10 20 10 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ SHORT TERM...13/SI LONG TERM....88/ALM AVIATION...13/SI
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1202 PM CDT SAT SEP 19 2015 ...UPDATE TO AVIATION... .SYNOPSIS... ISSUED AT 900 AM CDT SAT SEP 19 2015 WV Imagery and 12Z upper air analysis indicate a general westerly flow aloft prevailing across the Western High Plains. Meanwhile, a weak upper level shortwave trough is moving east- southeast across eastern Montana and northern Wyoming. Near the surface, a broad area of high pressure is shifting eastward across Nebraska and Kansas. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 111 AM CDT SAT SEP 19 2015 The main challenge in the short term will be low stratus potential up in the northeast zones (particularly around Hays) and if it will impact temperatures at all. A secondary push of cooler air was making its way south into southwest Kansas with a slight bump in winds from the north. On the 11-3.9u imagery during the overnight hours, we were watching an area of stratus advance south- southwestward toward north central KS. The HRRR suggests that this will reach as far southwest as a Dighton to Dodge City line by 14z. This may be a bit ambitious, but there is certainly some merit to this prog as there is some better low level moisture across central/south central Nebraska that wrapped around the low...which will likely continue to advect southwestward through the early morning hours. We will bump up the clouds in the Sky grids to reflect this latest thinking, especially northeast of the Dighton to Dodge City line. Any low stratus should erode by late morning given how shallow it will be. Temperatures today, with the fresh Canadian airmass in place, will only top out in the lower to mid 70s. Will go with slightly cooler temps in the north where low morning clouds will likely delay the diurnal warmup. Advancing to tonight, we will see low level winds turn back around to the south in response to another loosely organized Pacific system moving into the Northern Rockies. Some marginal moisture will return via the "scenic route" (Eastern New Mexico/western TX-OK Panhandles), and increased deformation/convergence in the 700-800mb layer will promote some elevated showers and isolated thunderstorms after 06z Sunday. We will maintain the 20-30 POPs across mainly the western third of the forecast area late tonight, with low Chance POPs between the Arkansas River and the OK border in the 12-18z Sunday time frame. .LONG TERM...(Sunday THROUGH Friday) ISSUED AT 352 AM CDT SAT SEP 19 2015 Our region of the world will once again see a warming trend going into next week as the primary polar jet shifts back to the north and mid level heights rise across the Southern and Central Rockies/adjacent High Plains. During the slow transition back into above-average temperatures, we will see low chances for precipitation, particularly early Sunday as one last shortwave trough ripples through the longwave trough. Highs Sunday will be tricky, and we feel that portions of south central Kansas, especially, will stay stuck in the 60s to lower 70s with elevated convection and stratus clouds lingering through at least the middle part of the day. The lee trough comes back strong by Monday and will be a quasi- steady feature through at least Wednesday. Afternoon temperatures will gradually increase each day with highs in the lower 90s in some locations. The global spectral models suggest a subtropical shortwave trough ejecting from the Baja California region into Rockies which will bring some mid level moisture across into the High Plains. We will have some Slight Chance to Chance POPs in the grids Wednesday Night through Thursday Night, but at this point, it does not look like a real good opportunity for widespread beneficial rainfall across our region given the degree of downslope momentum in the middle troposphere and the general weak nature of the subtropical system to begin with. Beyond mid-week, it certainly looks like we will continue the theme of above average temperatures across the Rockies and adjacent High Plains in the final days of September with both the GFS and the ECMWF showing some semblance of a longwave trough across western North America leading to fairly strong (warm and dry) southwest momentum across the Rockies. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Sunday AFTERNOON) ISSUED AT 1200 PM CDT SAT SEP 19 2015 VFR conditions will prevail at all TAF sites through early Sunday morning. Light northeasterly winds will prevail across western Kansas this afternoon as a surface high moves eastward across Nebraska and northern Kansas. Winds will then become more easterly 5 to 15kt this evening as the surface high pushes east into Iowa and northern Missouri, and more southeasterly early Sunday as it lifts northeastward into the Great Lakes Region. && .PRELIMINARY POINT TEMPS/POPS... DDC 73 55 76 58 / 0 10 10 0 GCK 74 53 81 57 / 0 10 10 0 EHA 75 50 85 56 / 0 10 10 0 LBL 75 54 85 58 / 0 20 10 0 HYS 71 52 79 59 / 0 10 10 0 P28 75 58 76 60 / 0 20 20 0 && .DDC Watches/Warnings/Advisories... NONE. && $$ SYNOPSIS...JJohnson SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
334 PM MDT SAT SEP 19 2015 .SYNOPSIS... THE BACKDOOR COLD FRONT THAT MOVED THROUGH THE AREA LAST NIGHT AND THIS MORNING WILL STALL ALONG THE CONTINENTAL DIVIDE AND WEAKEN THIS EVENING. THIS FEATURE WILL BE THE FOCUS FOR A FEW SHOWERS AND THUNDERSTORMS OVER WESTERN NEW MEXICO THROUGH THE EVENING HOURS. DRY AIR WILL MOVE INTO THE STATE FROM THE NORTHWEST ON SUNDAY AS THE FOUR CORNERS HIGH REBUILDS OVER ARIZONA. THE DRY AIR WILL KEEP SHOWERS AND THUNDERSTORMS CONFINED TO THE SOUTHWEST AND SOUTH-CENTRAL MOUNTAINS. SOUTHERLY FLOW BETWEEN A WEAK STORM SYSTEM OFF OF THE FAR SOUTHERN CALIFORNIA COAST AND THE FOUR CORNERS HIGH WILL BRING IN DEEP SUBTROPICAL MOISTURE AND SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS BEGINNING LATE- DAY MONDAY AND CONTINUING THROUGH WEDNESDAY. && .DISCUSSION... BACKDOOR COLD FRONT HAS PUSHED AS FAR WEST AS THE DIVIDE THIS AFTERNOON. ENOUGH WARMING HERE AT THE ABQ SUNPORT...HOWEVER...TO GET SOUTHWEST WINDS TO SURFACE...INDICATING THE AIRMASS IS QUITE SHALLOW AND WILL LIKELY GET MIXED OUT WEST OF THE CENTRAL MTN CHAIN LATE THIS AFTERNOON/EARLY EVENING. A BAND OF CONVECTION HAS DEVELOPED IN NW CATRON COUNTY AND THIS IS THE AREA OF SFC CONVERGENCE AND INSTABILITY THAT THE MODELS ATTEMPT TO BRING NEWD DURING THE EVENING. 18Z NAM12 NOT AT ALL EXCITED ABOUT IT AND WITH NO STRONG UPPER LEVEL LARGE SCALE FORCING TO SPEAK OF...SUSPECT IT`S ON THE RIGHT TRACK. GFS IS ONCE AGAIN OUT TO LUNCH WITH THIS SHALLOW BACKDOOR COLD FRONT SCENARIO. MAIN FORECAST CHANGE FOR SUNDAY WAS TO LOWER PRECIP CHANCES OVER THE SOUTHWEST AND SOUTH-CENTRAL MOUNTAINS. BOTH GFS AND NAM BRING IN SINGLE DIGIT RH AT/NEAR 500MB MAKING IT ALL BUT IMPOSSIBLE FOR CUMULUS UPDRAFTS TO SURVIVE OUTSIDE OF SW CATRON...SW SOCORRO AND SRN LINCOLN COUNTIES SUNDAY AFTERNOON. FAVORED AREA FOR ISOLATED THUNDERSTORMS APPEARS TO BE OVER SRN LINCOLN COUNTY WHERE THE SELY SFC RETURN FLOW PRODUCES SUFFICIENT CONVERGENCE AND MOISTURE ADVECTION. GFS AND NAM TRENDING TOWARD THE SLOWER ECMWF SOLUTION FOR NEXT WEEK. STARTED PROCESS OF LOWERING PRECIP CHANCES MONDAY AS NEARLY ALL MODELS ARE SLOWER WITH THE DEEPER MOISTURE AND PRECIP SHIELD IN THE STRONG SOUTHERLY FLOW BETWEEN A WEAK UPPER LOW SW OF SAN DIEGO AND THE UPPER HIGH OVER FAR W TX/NRN MEXICO. TUESDAY AND TUESDAY NIGHT NOW LOOKING LIKE THE MOST ACTIVE PERIOD AS ALL GLOBAL MODELS PRODUCING WIDESPREAD PRECIP OVER THE LAND OF ENCHANTMENT. 12Z GFS AND ECMWF HAVE NOW COME IN LINE WITH ONE ANOTHER FOR WEDNESDAY THROUGH FRIDAY. BOTH MODELS BRING IN DRIER AIR ON WLY FLOW ALOFT BEGINNING WEDNESDAY AFTERNOON. STILL PLENTY ACTIVE ALONG AND EAST OF THE CENTRAL MOUNTAIN CHAIN WEDNESDAY AFTERNOON BUT DRY AIR WINDS OUT OVER THE NW THIRD. THURSDAY AND FRIDAY LOOK LIKE DOWN DAYS AHEAD OF A HIGH AMPLITUDE UPPER LEVEL TROUGH WHICH BEGINS TO SPREAD SUBTROPICAL MOISTURE NEWD INTO WRN NM SATURDAY...AT LEAST ACCORDING TO THE GFS. ECMWF IS ABOUT 24 HRS SLOWER BUT VERY SIMILAR WITH THE OVERALL UPPER LEVEL PATTERN. LET THE EL NINO GAMES OF 2015 BEGIN. 33 && .FIRE WEATHER... ISOLATED TO SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS DEVELOPED SOUTH OF THE I40 CORRIDOR AS MID LEVEL MOISTURE SURGED NORTHWARD FROM THE SOUTHERN BAJA PENINSULA...WITH DRIER CONDITIONS ACROSS THE NORTHWEST. WINDS WILL CONTINUE SHIFTING SOUTHERLY CENTRAL AND EAST...WITH WESTERLIES WEST OF THE CONTDVD. SOUTH WINDS WILL ALSO BE BREEZY ACROSS THE NORTHEAST TOWARDS SUNSET THEN TAPERING OFF OVERNIGHT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL FAVOR AREAS ALONG AND SOUTH OF THE I40 CORRIDOR...WITH CHANCES ALONG THE CENTRAL MOUNTAIN CHAIN THE REST OF THE AFTERNOON INTO THE EVENING HOURS. TEMPERATURES WERE BELOW NORMAL IN THE EAST...NEAR NORMAL WEST OF THE CENTRAL MOUNTAIN CHAIN. SHOWERS AND THICK CLOUD COVER SOUTH OF THE I40 CORRIDOR WILL GRADUALLY DIMINISH OVERNIGHT AS RECOVERIES IMPROVE GREATLY AREAWIDE THAN PREVIOUS. TEMPERATURES WILL REBOUND TO NEAR AND ABOVE NORMAL READINGS SUNDAY FOLLOWING A DOWN TREND IN MIN RH VALUES ACROSS THE NORTHERN HALF OF THE STATE AS DRIER MID LEVEL AIR FILTERS IN FROM THE NORTHWEST...WHILE RH VALUES REMAIN FAIR ACROSS THE FAR EAST AND SOUTHERN HALF OF THE STATE. ANY CHANCE OF SHOWERS WILL BE LIMITED TO SOUTHERN AREAS. OVERNIGHT RECOVERIES WILL DOWNTREND ACROSS PORTIONS OF THE NORTHWEST PLATEAU...ADJACENT HIGHLANDS AND THE SANGRE DE CRISTOS...WHILE REMAINING GOOD TO EXCELLENT ELSEWHERE. DOWN TREND IN RH VALUES WILL CONTINUE MONDAY ACROSS NORTHERN AREAS ...ESPECIALLY ACROSS THE NORTHWEST AS DRIER AIR REMAINS OVER THE NORTHERN HALF OF THE STATE. TEMPERATURES WILL BE NEAR NORMAL...ABOVE NORMAL IN THE EAST. ANY SHOWER CHANCES WILL BE LIMITED TO THE SOUTHWEST MOUNTAINS BECAUSE OF AN UPTREND IN MOISTURE LEVELS AHEAD OF AN APPROACHING UPPER LEVEL SYSTEM IN THE EASTERN PACIFIC. LATE MONDAY INTO TUESDAY...THE UPPER LEVEL LOW LOOKS TO CROSS OVER THE CALIFORNIA...NEVADA VALLEY USHERING THE MOISTURE BULLS EYE OVER ARIZONA...WITH SCATTERED CHANCES ACROSS WESTERN AND CENTRAL AREAS...BECOMING WIDESPREAD LATE TUESDAY INTO WEDNESDAY. RH VALUES AND RECOVERIES WILL GREATLY IMPROVE WEST TO EAST. BY THURSDAY...MODELS BEGAN TO DIFFER ON TIMING OF SHOWERS MOVING OUT OF THE STATE AS UPPER LEVEL RIDGING TAKES OVER TOWARD THE WEEKEND VENT RATES WILL IMPROVE CENTRAL AND NORTH SUNDAY...POOR ACROSS THE SOUTH CENTRAL MOUNTAINS...THEN BECOMING GOOD TO EXCELLENT IN THE EAST...FAIR IN THE SOUTH...TO POOR ACROSS PORTIONS OF THE NORTHWEST...SOUTH CENTRAL AND NORTH CENTRAL MOUNTAINS MONDAY...THEN IMPROVING AREA WIDE TUESDAY. && .AVIATION... 18Z TAF CYCLE AS THE BACK DOOR COLD FRONT CONTINUES PUSHING TOWARD THE SOUTHWEST MTNS FOLLOWING MID LEVEL MOISTURE FILTERING NORTHWARD FROM THE SOUTHERN BAJA PENINSULA...THICK CLOUD COVER/MVFR CIGS WILL CONTINUE TO FAVOR THE EAST CENTRAL AND SOUTHEAST PLAINS THROUGHOUT THE DAY...WITH PERIODS OF MVFR CIGS ALONG THE EAST SLOPES OF THE SANGRE DE CRISTOS. WINDS WILL CONTINUE SHIFTING SOUTH EASTERLY CENTRAL AND EAST AS POST BACK DOOR FRONTAL WINDS WASH OUT...WITH BREEZY SOUTHERLY WINDS ACROSS THE NORTHEAST. WINDS ACROSS WESTERN NM WILL SHIFT WESTERLY AFTER 20Z. HRRR MODELS ARE INDICATING SHRA/TSRA CHANCES FAVORING AREAS SOUTH OF THE INTERSTATE 40 CORRIDOR BUT ONLY ADDED VCSH FOR KROW. && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 45 86 42 86 / 5 0 0 0 DULCE........................... 33 79 28 81 / 10 0 0 0 CUBA............................ 46 77 44 78 / 10 0 0 5 GALLUP.......................... 41 85 37 85 / 5 0 0 5 EL MORRO........................ 39 78 36 78 / 10 0 0 10 GRANTS.......................... 41 82 37 82 / 10 5 0 5 QUEMADO......................... 52 79 49 77 / 20 10 0 20 GLENWOOD........................ 52 78 53 77 / 20 30 10 20 CHAMA........................... 42 73 32 74 / 10 0 0 5 LOS ALAMOS...................... 55 78 56 79 / 20 0 0 5 PECOS........................... 51 76 52 77 / 10 0 0 5 CERRO/QUESTA.................... 45 76 40 77 / 5 0 0 5 RED RIVER....................... 43 67 36 69 / 10 0 0 5 ANGEL FIRE...................... 49 68 44 69 / 10 0 0 5 TAOS............................ 42 80 40 82 / 5 0 0 5 MORA............................ 48 74 48 76 / 10 0 0 5 ESPANOLA........................ 49 85 47 85 / 10 0 0 0 SANTA FE........................ 53 79 54 79 / 10 0 0 5 SANTA FE AIRPORT................ 51 83 51 83 / 10 0 0 5 ALBUQUERQUE FOOTHILLS........... 60 84 60 84 / 10 5 0 5 ALBUQUERQUE HEIGHTS............. 60 86 61 86 / 10 0 0 0 ALBUQUERQUE VALLEY.............. 58 88 55 88 / 10 0 0 0 ALBUQUERQUE WEST MESA........... 58 87 59 87 / 10 0 0 0 LOS LUNAS....................... 54 89 52 89 / 10 0 0 5 RIO RANCHO...................... 57 87 58 87 / 10 0 0 0 SOCORRO......................... 59 88 60 90 / 10 5 5 5 SANDIA PARK/CEDAR CREST......... 54 80 52 81 / 20 5 0 5 TIJERAS......................... 56 82 46 83 / 20 5 0 5 MORIARTY/ESTANCIA............... 45 83 40 84 / 10 5 0 5 CLINES CORNERS.................. 52 79 52 81 / 10 5 0 5 GRAN QUIVIRA.................... 54 79 55 81 / 10 5 5 5 CARRIZOZO....................... 58 80 58 84 / 20 20 5 10 RUIDOSO......................... 53 72 54 76 / 20 30 10 20 CAPULIN......................... 50 77 51 81 / 10 0 0 5 RATON........................... 48 84 49 88 / 5 0 0 0 SPRINGER........................ 49 84 49 87 / 5 0 0 0 LAS VEGAS....................... 48 82 48 84 / 10 5 0 5 CLAYTON......................... 56 85 58 90 / 10 0 0 0 ROY............................. 53 83 53 85 / 10 5 0 0 CONCHAS......................... 60 89 60 91 / 10 5 0 0 SANTA ROSA...................... 60 88 60 89 / 10 5 0 0 TUCUMCARI....................... 60 90 61 93 / 10 5 0 0 CLOVIS.......................... 60 85 60 90 / 10 10 0 0 PORTALES........................ 62 84 62 89 / 10 10 0 0 FORT SUMNER..................... 62 86 62 89 / 5 5 0 0 ROSWELL......................... 63 88 61 93 / 10 10 0 0 PICACHO......................... 58 84 58 86 / 20 20 5 10 ELK............................. 56 73 56 78 / 20 30 10 10 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1146 AM MDT SAT SEP 19 2015 .AVIATION... 18Z TAF CYCLE AS THE BACK DOOR COLD FRONT CONTINUES PUSHING TOWARD THE SOUTHWEST MTNS FOLLOWING MID LEVEL MOISTURE FILTERING NORTHWARD FROM THE SOUTHERN BAJA PENINSULA...THICK CLOUD COVER/MVFR CIGS WILL CONTINUE TO FAVOR THE EAST CENTRAL AND SOUTHEAST PLAINS THROUGHOUT THE DAY...WITH PERIODS OF MVFR CIGS ALONG THE EAST SLOPES OF THE SANGRE DE CRISTOS. WINDS WILL CONTINUE SHIFTING SOUTH EASTERLY CENTRAL AND EAST AS POST BACK DOOR FRONTAL WINDS WASH OUT...WITH BREEZY SOUTHERLY WINDS ACROSS THE NORTHEAST. WINDS ACROSS WESTERN NM WILL SHIFT WESTERLY AFTER 20Z. HRRR MODELS ARE INDICATING SHRA/TSRA CHANCES FAVORING AREAS SOUTH OF THE INTERSTATE 40 CORRIDOR BUT ONLY ADDED VCSH FOR KROW. 32 && .PREV DISCUSSION...340 AM MDT SAT SEP 19 2015... .SYNOPSIS... A STRONG COLD FRONT SURGED THROUGH CENTRAL AND EASTERN NEW MEXICO AS OF EARLY SATURDAY. GUSTY NORTHEAST TO EAST WINDS ARE EXPECTED TO SLOWLY DIMINISH AS THE MORNING PROGRESSES. HIGHS IN THE EAST WILL FINALLY FALL TO BELOW AVERAGE TODAY...BUT WILL BE WITHIN A FEW DEGREES BOTH ABOVE AND BELOW NORMAL FOR THE CENTRAL AND WEST. BEST CHANCES FOR SHOWERS AND STORMS WILL BE SOUTH OF INTERSTATE 40 TODAY THROUGH SUNDAY...WITH HIGHS REBOUNDING SUNDAY. INCREASING MOISTURE IN ADVANCE OF AN UPPER LOW NEAR BAJA CALIFORNIA WILL BOOST CHANCES FOR SHOWERS AND STORMS MONDAY THROUGH WEDNESDAY BEFORE DRIER WEATHER DOMINATES LATE NEXT WEEK. && .DISCUSSION... FRONT MADE IT/S WAY THROUGH THE RGV AND APPEARS TO BE INVOF THE CONTDVD EARLY THIS MORNING. CONSIDERED DROPPING THE WIND ADVY FOR THE MIDDLE RGV...AS WINDS AT THE SUNPORT HAD DECREASED...WHILE ALLOWING THE REMAINDER OF THE ADVY TO CONTINUE UNTIL 7 AM...HOWEVER KABQ GUSTS HAVE INCREASED AGAIN...SO DECIDED TO LET THE ADVY CONTINUE IN IT/S ENTIRETY. OTHERWISE...THE FRONT LOOKED TO INITIATE AN ISOLD STORM IN THE LOWER RGV AROUND MIDNIGHT...WHICH DISSIPATED FAIRLY QUICKLY. ATTM ECHOES OBSERVED TO OUR SOUTH ASSOCIATED WITH DECAYING COMPLEX AS WELL AS FRONTAL BOUNDARY. FORECAST BEST MOISTURE AND INSTAB FOR TODAY LIKELY TO REMAIN SOUTH OF I-40 BUT THERE MAY BE ENOUGH MOISTURE AND INSTAB FOR AN ISOLD CELL OVER THE NRN MTS...SO LITTLE CHANGE FROM INHERITED GRIDS. HIGHS IN THE EAST FALL BELOW AVERAGE TODAY WHILE COOLER CENTRAL BUT STILL WITHIN A FEW DEGREES OF NORMAL. HIGHS REBOUND SUNDAY WITH BEST MOISTURE AND INSTAB FORECAST SOUTH OF I-40 AGAIN. GFS REMAINS SOMEWHAT FASTER THAN THE ECMWF OPENING UP THE UPPER LOW OFF BAJA AND BRINGING IT AS WELL AS A SLUG OF MOISTURE INTO NEW MEXICO...BUT THE IDEA IS THE SAME...MAINLY THE TIMING IS OFF. TUESDAY MAY SEE THE MOST WIDESPREAD SHOWERS AND STORMS WITH WETTING RAIN...WITH A DRY OUT FROM WEST TO EAST WEDNESDAY INTO THURSDAY. THERE MAY BE A WEAK SURFACE BOUNDARY IN THE EAST THURSDAY...BUT DOESN/T LOOK TO HAVE SIGNIFICANT IMPACT. UPPER HIGH DEVELOPS OVER THE STATE LATE IN THE WEEK...BUT POTENTIAL LATE NEXT WEEKEND FOR INCREASING WIND AND SHOWERS/STORMS WEST AND NORTH AS A STRONG TROUGH TRACKS THROUGH THE NRN/CENTRAL ROCKIES. && .FIRE WEATHER... BACK DOOR FRONT HAS POWERED ITS WAY THROUGH THE GAPS OF THE CENTRAL MOUNTAIN CHAIN AND IS CURRENTLY PUSHING TOWARD THE CONTINENTAL DIVIDE. GUSTY WINDS WILL CONTINUE BELOW CANYONS THROUGH SUNRISE OR SHORTLY THEREAFTER. LOW LEVEL MOISTURE BEHIND THE FRONT IS ALSO MAKING ITS WAY TOWARD THE CONTDVD. THIS COMBINED WITH SOME MID LEVEL MOISTURE CREEPING NORTHWARD SHOULD ALLOW FOR SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS THE WEST CENTRAL AND NORTHWEST HIGHLANDS THIS AFTERNOON AND EVENING. DESPITE THE INCREASE IN LOW LEVEL MOISTURE ACROSS THE PLAINS...TEMPERATURES WILL BE MUCH COOLER AND THEREFORE...CONDITIONS APPEAR TO BE TOO STABLE FOR MUCH...IF ANY...SHOWER DEVELOPMENT. MINIMUM HUMIDITIES THIS AFTERNOON WILL BE MUCH HIGHER THAN YESTERDAY FOR MOST AREAS...THOUGH WILL REMAIN BELOW 15 PERCENT ACROSS THE NORTHWEST PLATEAU. GOOD TO EXCELLENT RECOVERIES ARE EXPECTED TONIGHT. ON SUNDAY...DRY MID LEVEL AIR WILL NOSE BACK INTO THE NORTHERN HALF OR SO OF THE STATE...CONFINING SHOWERS AND THUNDERSTORMS TO THE SOUTHERN TIER OF THE FORECAST AREA...THOUGH WETTING RAINS WILL BE SPOTTY AT BEST. TEMPERATURES WILL REBOUND WHICH WILL RESULT IN DAYTIME HUMIDITIES TRENDING SHARPLY DOWNWARD. EARLY NEXT WEEK...MODELS CONTINUE TO BE AT ODDS REGARDING THE TIMING OF A SHORTWAVE TROUGH...OR TWO...AND THE ACCOMPANYING MOISTURE AND PRECIPITATION. IN GENERAL...MODELS AGREE THAN A WEAK SHORTWAVE WILL EJECT FROM THE MAIN LOW OVER THE PACIFIC AND MOVE NORTHEASTWARD OVER AZ AND NM SOMETIME BETWEEN MONDAY NIGHT AND TUESDAY. THEN...THE MAIN LOW WILL OPEN INTO A WAVE AND ALSO EJECT NORTHEASTWARD AROUND THE TUESDAY NIGHT INTO WEDNESDAY TIME FRAME. THE GFS TENDS TO BRING THE MAIN SLUG OF MOISTURE WITH THE INITIAL SHORTWAVE...WHILE THE ECMWF TENDS TO KEEP THAT MOISTURE LARGELY OVER AZ. HOWEVER...THE ECMWF DOES SHOW WIDESPREAD WETTING RAINS WITH THE MAIN TROUGH AS IT CROSSES NM. SINCE THESE DIFFERENCES HAVE BEEN PERSISTENT FOR MANY DAYS...BEST WE CAN SAY FOR NOW IS THAT MOISTURE AND PRECIPITATION CHANCES SHOULD BE TRENDING UPWARD FOR AT LEAST CENTRAL AND WESTERN NM EARLY NEXT WEEK. MANY AREAS SHOULD SEE WETTING RAINS...JUST A QUESTION OF TIMING. LOOKS LIKE BOTH MODELS REBUILD THE UPPER LEVEL HIGH OVER THE DESERT SOUTHWEST LATE NEXT WEEK WITH THUNDERSTORM CHANCES SIGNIFICANTLY REDUCED. POOR TO FAIR VENTILATION IS EXPECTED FOR MUCH OF THE RIO GRANDE VALLEY AND AREAS EASTWARD...WHILE SOME IMPROVEMENT IN VENT RATES WILL BE NOTED ACROSS THE WEST TODAY. WITH THE EXCEPTION OF POOR VENT RATES ACROSS THE LOWER RIO GRANDE VALLEY...VENT RATES ON SUNDAY SHOULD BE GOOD TO VERY GOOD AREAWIDE. THOUGH THE DETAILS ARE STILL BEING IRONED OUT FOR EARLY NEXT WEEK...IT CURRENTLY LOOKS LIKE POOR TO FAIR VENTILATION WILL PREVAIL ACROSS NORTHWEST AND NORTH CENTRAL AREAS MONDAY AND TUESDAY...WITH GOOD OR BETTER VENT RATES PREVAILING ELSEWHERE. && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
107 PM CDT SAT SEP 19 2015 .DISCUSSION... && .AVIATION... CEILINGS WILL LOWER OVERNIGHT WHEN LIFT OVER THE COLD FRONT WILL HELP GENERATE SHOWERS AND A FEW THUNDERSTORMS OVER THE SOUTHERN OR CENTRAL THIRD OF OKLAHOMA. MVFR CEILINGS ARE EXPECTED BY SUNRISE SUNDAY IN MUCH OF THIS AREA. THUNDER IS LESS LIKELY THROUGH THE MORNING, BUT RAIN AND LOW CEILINGS WILL LIKELY CONTINUE. && .PREV DISCUSSION... /ISSUED 1140 AM CDT SAT SEP 19 2015/ UPDATE... ADJUSTED PRECIP/WX... TEMPS... DISCUSSION... BROKEN AREA OF SHOWERS CONTINUES TO SLOWLY DISSIPATE AND MOVE SOUTHWARD OUT OF SOUTH CENTRAL OK INTO NRN TX THIS MORNING. REMOVED CHANCES ACROSS CENTRAL AND SWRN OK AND WRN N TX GIVEN CURRENT RADAR TRENDS AND MORE STABLE AIRMASS BUILDING INTO THE REGION AS THE SFC FRONT HAS PUSHED WELL SOUTH OF THE RED RIVER. BROUGHT BACK A 15 TO 20 PERCENT CHANCE OF ISOLATED SHOWER DEVELOPMENT IN SWRN OK/WRN N TX THROUGH THE AFTN... AS THE RIDGE CENTERED OVER WEST TX COMES INTO PLAY... WITH MODEST MOISTURE CONTINUE TO TRAVERSE THE CAPROCK INTO THE TX PANHANDLE AND WRN OK. WV IMAGERY SHOWS THIS FEATURE QUITE WELL. IN RESPONSE... THERE IS A SLIGHT SIGNAL OF ISENTROPIC ASCENT FROM THE TX PANHANDLE INTO THE RED RIVER VALLEY OF SWRN OK/WRN N TX THROUGH 00Z (0700 PM CDT). HOWEVER... GIVEN 4000 TO 5000 FT CLOUD BASES AND 20 TO 25 DEGREES SFC TEMP/DPT SPREADS... SHOWERS WILL BE FAR AND FEW BETWEEN IF ANYTHING DEVELOPS THIS AFTN. THE VAST MAJORITY WILL STAY DRY. JTK PREV DISCUSSION... /ISSUED 657 AM CDT SAT SEP 19 2015/ DISCUSSION... PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW. AVIATION... BRIEF MVFR CIGS ARE EXPECTED THIS MORNING AT A FEW OF THE TERMINALS...BUT CONDITIONS WILL IMPROVE TO VFR AROUND 14-16Z. ALL OF THE SHOWERS/STORMS HAVE MOVED INTO SE OK THIS MORNING SO DO NOT EXPECT ANY PRECIP OVER THE TERMINALS FOR THE NEXT 12 HOURS. MID TO HIGH CLOUDS WILL REMAIN OVERHEAD THROUGH MOST OF THE DAY. EXPECT NORTH WINDS THROUGH THE AFTERNOON...SHIFTING TO THE ENE THIS EVENING. PREV DISCUSSION... /ISSUED 313 AM CDT SAT SEP 19 2015/ DISCUSSION... SCATTERED SHOWERS AND THUNDERSTORMS WILL SLOWLY CONTINUE TO SLIDE SOUTH WITH THE 850 MB FRONTOGENETIC ZONE THROUGH THE MORNING HOURS. THE HRRR HAS THE BEST HANDLE ON WHAT IS OCCURRING RIGHT NOW SO POPS WERE ADJUSTED UPWARD ALONG THIS NARROW ZONE THROUGH SUNRISE. MOST OF THE RAIN WILL MOVE TOWARD THE RED RIVER BEFORE LUNCHTIME AND SKIES WILL CONTINUE TO CLEAR FROM NE TO SW. EXPECT LINGERING STRATUS ACROSS THE SW...HOWEVER...THROUGH MOST OF THE DAY. MUCH COOLER TEMPS ARE EXPECTED TODAY BEHIND THE COLD FRONT FROM THE MID 70S NORTHWARD TO THE LOW 80S SOUTHWARD. THE NEXT CHANCE FOR RAIN RETURNS SUN AS ISENTROPIC ASCENT DEVELOPS AND A WEAK MID LEVEL SHORTWAVE TROUGH MOVES OUT OF THE ROCKIES. THE HIGHEST CHANCES WILL LIKELY BE DURING THE MORNING HOURS ACROSS WESTERN AND CENTRAL OK...AND THEN SHIFT NE/E DURING THE DAY. DECIDED TO LOWER TEMPS ACROSS THE NORTH AND EAST FOR THIS REASON SIMILAR TO THE NAM12. RAIN CHANCES WILL LINGER ACROSS THE EAST THROUGH EARLY MON AM AS A MORE SIGNIFICANT MID TO UPPER LEVEL SHORTWAVE TROUGH MOVES INTO NE/E OK. MONDAY SHOULD BE MOSTLY CLEAR AS THE WAVE QUICKLY MOVES INTO THE MISS RIVER VALLEY. TEMPS WILL BEGIN TO REBOUND BACK TO/OR JUST ABOVE AVG MONDAY...AND THEN WARM UP THROUGH MID WEEK AS THE SUBTROPICAL RIDGE MOVES OVER THE SOUTHERN PLAINS. MOST OF THE NWP MODELS INDICATE A MID TO UPPER SHORTWAVE TROUGH WILL MOVE SOMEWHERE NEAR KS THROUGH THURS SO WILL GO WITH SOME SLIGHT CHCS ACROSS NORTHERN OK DURING THIS TIME PERIOD. OTHERWISE...EXPECT ABOVE AVG TEMPS THROUGH THE EXTENDED PERIOD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 61 81 64 87 / 60 60 30 10 HOBART OK 62 85 65 91 / 60 50 20 0 WICHITA FALLS TX 66 88 67 92 / 60 50 20 0 GAGE OK 58 84 62 90 / 30 40 10 0 PONCA CITY OK 57 76 62 84 / 20 30 30 10 DURANT OK 67 86 66 89 / 40 50 30 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 03/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
1140 AM CDT SAT SEP 19 2015 .UPDATE... ADJUSTED PRECIP/WX... TEMPS... && .DISCUSSION... BROKEN AREA OF SHOWERS CONTINUES TO SLOWLY DISSIPATE AND MOVE SOUTHWARD OUT OF SOUTH CENTRAL OK INTO NRN TX THIS MORNING. REMOVED CHANCES ACROSS CENTRAL AND SWRN OK AND WRN N TX GIVEN CURRENT RADAR TRENDS AND MORE STABLE AIRMASS BUILDING INTO THE REGION AS THE SFC FRONT HAS PUSHED WELL SOUTH OF THE RED RIVER. BROUGHT BACK A 15 TO 20 PERCENT CHANCE OF ISOLATED SHOWER DEVELOPMENT IN SWRN OK/WRN N TX THROUGH THE AFTN... AS THE RIDGE CENTERED OVER WEST TX COMES INTO PLAY... WITH MODEST MOISTURE CONTINUE TO TRAVERSE THE CAPROCK INTO THE TX PANHANDLE AND WRN OK. WV IMAGERY SHOWS THIS FEATURE QUITE WELL. IN RESPONSE... THERE IS A SLIGHT SIGNAL OF ISENTROPIC ASCENT FROM THE TX PANHANDLE INTO THE RED RIVER VALLEY OF SWRN OK/WRN N TX THROUGH 00Z (0700 PM CDT). HOWEVER... GIVEN 4000 TO 5000 FT CLOUD BASES AND 20 TO 25 DEGREES SFC TEMP/DPT SPREADS... SHOWERS WILL BE FAR AND FEW BETWEEN IF ANYTHING DEVELOPS THIS AFTN. THE VAST MAJORITY WILL STAY DRY. JTK && .PREV DISCUSSION... /ISSUED 657 AM CDT SAT SEP 19 2015/ DISCUSSION... PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW. AVIATION... BRIEF MVFR CIGS ARE EXPECTED THIS MORNING AT A FEW OF THE TERMINALS...BUT CONDITIONS WILL IMPROVE TO VFR AROUND 14-16Z. ALL OF THE SHOWERS/STORMS HAVE MOVED INTO SE OK THIS MORNING SO DO NOT EXPECT ANY PRECIP OVER THE TERMINALS FOR THE NEXT 12 HOURS. MID TO HIGH CLOUDS WILL REMAIN OVERHEAD THROUGH MOST OF THE DAY. EXPECT NORTH WINDS THROUGH THE AFTERNOON...SHIFTING TO THE ENE THIS EVENING. PREV DISCUSSION... /ISSUED 313 AM CDT SAT SEP 19 2015/ DISCUSSION... SCATTERED SHOWERS AND THUNDERSTORMS WILL SLOWLY CONTINUE TO SLIDE SOUTH WITH THE 850 MB FRONTOGENETIC ZONE THROUGH THE MORNING HOURS. THE HRRR HAS THE BEST HANDLE ON WHAT IS OCCURRING RIGHT NOW SO POPS WERE ADJUSTED UPWARD ALONG THIS NARROW ZONE THROUGH SUNRISE. MOST OF THE RAIN WILL MOVE TOWARD THE RED RIVER BEFORE LUNCHTIME AND SKIES WILL CONTINUE TO CLEAR FROM NE TO SW. EXPECT LINGERING STRATUS ACROSS THE SW...HOWEVER...THROUGH MOST OF THE DAY. MUCH COOLER TEMPS ARE EXPECTED TODAY BEHIND THE COLD FRONT FROM THE MID 70S NORTHWARD TO THE LOW 80S SOUTHWARD. THE NEXT CHANCE FOR RAIN RETURNS SUN AS ISENTROPIC ASCENT DEVELOPS AND A WEAK MID LEVEL SHORTWAVE TROUGH MOVES OUT OF THE ROCKIES. THE HIGHEST CHANCES WILL LIKELY BE DURING THE MORNING HOURS ACROSS WESTERN AND CENTRAL OK...AND THEN SHIFT NE/E DURING THE DAY. DECIDED TO LOWER TEMPS ACROSS THE NORTH AND EAST FOR THIS REASON SIMILAR TO THE NAM12. RAIN CHANCES WILL LINGER ACROSS THE EAST THROUGH EARLY MON AM AS A MORE SIGNIFICANT MID TO UPPER LEVEL SHORTWAVE TROUGH MOVES INTO NE/E OK. MONDAY SHOULD BE MOSTLY CLEAR AS THE WAVE QUICKLY MOVES INTO THE MISS RIVER VALLEY. TEMPS WILL BEGIN TO REBOUND BACK TO/OR JUST ABOVE AVG MONDAY...AND THEN WARM UP THROUGH MID WEEK AS THE SUBTROPICAL RIDGE MOVES OVER THE SOUTHERN PLAINS. MOST OF THE NWP MODELS INDICATE A MID TO UPPER SHORTWAVE TROUGH WILL MOVE SOMEWHERE NEAR KS THROUGH THURS SO WILL GO WITH SOME SLIGHT CHCS ACROSS NORTHERN OK DURING THIS TIME PERIOD. OTHERWISE...EXPECT ABOVE AVG TEMPS THROUGH THE EXTENDED PERIOD. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 77 61 81 64 / 20 40 50 30 HOBART OK 77 62 85 65 / 20 50 50 20 WICHITA FALLS TX 79 66 88 67 / 40 40 40 20 GAGE OK 76 58 84 62 / 10 30 40 10 PONCA CITY OK 77 57 76 62 / 10 20 30 30 DURANT OK 83 67 86 66 / 30 40 50 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
555 PM EDT SAT SEP 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. HIGH PRESSURE WILL BRING A RETURN OF NEAR NORMAL DAYTIME TEMPERATURES FOR SUNDAY AND CONTINUE INTO THE MIDDLE OF NEXT WEEK. AN UPPER LEVEL LOW MAY LEAD TO A FEW SHOWERS MONDAY OR TUESDAY OVER THE SOUTHERN MOUNTAINS. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... EARLY THIS AFTERNOON...SURFACE LOW LIFTING OUT OF EASTERN GREAT LAKES WITH TRAILING COLD FRONT PROGRESSING ACROSS OHIO VALLEY /AT 17Z MOVING INTO CENTRAL OH/. THERE IS GOOD AGREEMENT ON THE TIMING OF THE FRONT...ENTERING WESTERN PA SHORTLY AFTER 18Z...AND MOVING INTO THE SUSQ VALLEY AROUND 03Z SUN. CONVECTION ALONG THE COLD FRONT WILL ORGANIZE TO OUR WEST AND ENTER THE NWRN MOUNTAINS DURING THE MID AFTERNOON. TOUGH TO FIND MUCH CAPE FURTHER EAST...SO SHOULD SEE A DEF WEAKENING TREND TO PRECIP AS FRONT SLIDES INTO THE ALLEGHENY FRONT AND CENTRAL MTNS. INTERESTING FEATURE FIRST HINTED AT BY THE LAST COUPLE RUNS OF THE HRRR /AND LIKELY WELL OVERDONE BY HRRR/ AND ON DISPLAY IN THE WV IS A VERY SUBTLE SHORTWAVE SLIDING FROM THE SOUTHERN TIP OF ILLINOIS AT 10Z TO SE OHIO AT 17Z BEGINNING TO SHOW SOME ENHANCED CLOUD HEIGHTS IN A NARROW DEFORMATION ZONE. THIS FEATURE WILL SLIDE NE IN QUICK MID-LEVEL FLOW OVER NEXT SEVERAL HOURS AND SHOULD BE ENOUGH TO KICK START SOME TSTMS OVER W PA WHERE CAPES ARE ONLY AROUND 500J/KG. IT REMAINS A BIT UNCLEAR JUST HOW FAR EAST OF A LINE FROM ABOUT BEDFORD TO STATE COLLEGE TO WILLIAMSPORT THE RAIN WILL MANAGE TO GET BEFORE PETERING OUT THOUGH...SO HELD ONTO SCT POPS THERE...RAMPING POPS HIGHER HEADING INTO NW MTNS. DID HOLD TSTM PROBS IN THE SCT CATEGORY...WITH FAST FLOW NOT TOTALLY RULING OUT AN ISOLATED STRONGER WIND GUST THERE /AS NOTED IN THE SPC DAY1 DISCUSSION CONCERNING A MARGINAL RISK/. WE`LL EEK OUT ONE MORE WARM DAY AHEAD OF THE COLD FRONT WITH HIGHS IN THE MID 70S TO MID 80S MOST LOCALES...WITH A SSW BREEZE OVER WESTERN SECTIONS. A COOL DOWN WILL BEGIN TONIGHT AS HIGH PRESSURE PUSHES QUICKLY INTO THE EASTERN GR LAKES AND SHOVES THE COLD FRONT OFF TO THE SOUTH. LOWS WILL RANGE FROM THE CHILLY MID 40S OVER THE NORTH TO AROUND 60 IN THE SOUTHEAST. OVER AREAS WHERE SKIES CLEAR TONIGHT...FOG SEEMS LIKELY LATE. THE BEST CHANCE WOULD SEEM TO BE OVER THE NORTHERN MOUNTAINS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... CLOUDS WILL SETTLE OFF TO THE SOUTH SUNDAY AS HIGH PRESSURE QUICKLY MOVES INTO NORTHERN PA/SOUTHERN NY. IT WILL BE A MARKEDLY COOLER DAY WITH HIGHS AVERAGING AROUND 10 DEG COOLER THAN TODAY. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... PATCHY FROST IS POSSIBLE OVER THE NORTHWEST VALLEYS AS TEMPERATURES DROP INTO THE MID 30S BY MONDAY MORNING. TEMPERATURES WILL MODERATE AFTER THAT AS AN UPPER TROUGH DRIFTS TOWARD PENNSYLVANIA FROM THE MIDWEST. INCREASING CLOUDS AHEAD OF THIS SYSTEM WILL THEN LEAD TO ISOLATED SHOWERS LATE MONDAY INTO TUESDAY. THE SLOW MOVING UPPER TROUGH DIGS INTO THE SOUTHEAST STATES...ULTIMATELY CLOSING OFF NEAR THE CAROLINA COAST. UNCERTAINTY IN THE FORECAST INCREASES IN THIS PERIOD AS THE SYSTEM MAY STILL BE CLOSE ENOUGH TO THE AREA TO BRING AN EASTERLY WIND AND LOW CLOUD/SHOWER CHANCES. KEPT THINGS DRY FOR THIS TIME THOUGH BUT WILL HAVE TO ADJUST AS THE TRACK OF THE UPPER TROUGH/LOW COMES INTO FOCUS THROUGH EARLY WEEK. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... REGIONAL RADAR AT 21Z SHOWS A LINE OF SHRA/TSRA ALONG COLD FRONT MOVING INTO WESTERN PA. FROPA IS LIKELY TO BE ACCOMPANIED BY A A BRIEF TSRA AND A WIND SHIFT FROM SW TO NW AT KBFD ARND 23Z. UPSTREAM REPORTS AT KERI AND KWBC SHOWING A SCT LYR AT 700FT IMMEDIATELY BEHIND FRONT. FEEL A BRIEF DIP TO IFR CIGS AT KBFD IS QUITE POSSIBLE BTWN 23Z-01Z AS POST-FRONTAL MOISTURE IS FORCED OVER THE HIGH TERRAIN SURROUNDING KBFD. DRIER AIR WILL WORK IN ON NW FLOW LATER TONIGHT...LIKELY RESULTING IN A MORE FAVORABLE /MVFR/ STRATOCU DECK OVERNIGHT. ELSEWHERE...EXPECT SHOWERS TO DWINDLE AS WEAKENING FRONT MOVES SE INTO THE REST OF THE AREA LATE THIS EVENING. LATEST NEAR TERM MDLS SUGGEST THE DWINDLING LINE OF SHOWERS WILL MAKE IT TO KIPT/KUNV/KAOO/KJST AS FRONT MOVES THRU ARND 03Z. FURTHER SE...THE FRONT SHOULD COME THRU DRY ARND 07Z AT KMDT/KLNS. A PERIOD OF MVFR CIGS IS LIKELY AT KUNV/KAOO BTWN 03Z-06Z BEFORE DRIER NW FLOW BRINGS IMPROVEMENT LATE TONIGHT. AT KJST...UPSLOPE FLOW COULD MAINTAIN MVFR CIGS THRU DAWN. FURTHER SE...MDL SOUNDINGS SUGGEST VFR CONDS ARE LIKELY TO LAST THRU THE ENTIRE NIGHT AT KIPT/KMDT/KLNS. HIGH PRES AND DRY AIR MASS WILL BUILD IN FROM THE GRT LKS ON SUNDAY...BRINGING A NEAR CERTAINTY OF WIDESPREAD VFR CONDS. PRES GRADIENT BTWN HIGH PRES TO THE WEST AND LOW PRES OFF THE E COAST...WILL CREATE SOME FAIRLY GUSTY NORTH WINDS SUNDAY...ESP ACROSS EASTERN PA...WHERE BUFKIT SOUNDINGS INDICATE GUSTS NR 20KTS. OUTLOOK... SUN-WED...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/RXR NEAR TERM...LA CORTE/RXR SHORT TERM...LA CORTE LONG TERM...LA CORTE/TYBURSKI AVIATION...FITZGERALD/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
339 PM EDT SAT SEP 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. HIGH PRESSURE WILL BRING A RETURN OF NEAR NORMAL DAYTIME TEMPERATURES FOR SUNDAY AND CONTINUE INTO THE MIDDLE OF NEXT WEEK. AN UPPER LEVEL LOW MAY LEAD TO A FEW SHOWERS MONDAY OR TUESDAY OVER THE SOUTHERN MOUNTAINS. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... EARLY THIS AFTERNOON...SURFACE LOW LIFTING OUT OF EASTERN GREAT LAKES WITH TRAILING COLD FRONT PROGRESSING ACROSS OHIO VALLEY /AT 17Z MOVING INTO CENTRAL OH/. THERE IS GOOD AGREEMENT ON THE TIMING OF THE FRONT...ENTERING WESTERN PA SHORTLY AFTER 18Z...AND MOVING INTO THE SUSQ VALLEY AROUND 03Z SUN. CONVECTION ALONG THE COLD FRONT WILL ORGANIZE TO OUR WEST AND ENTER THE NWRN MOUNTAINS DURING THE MID AFTERNOON. TOUGH TO FIND MUCH CAPE FURTHER EAST...SO SHOULD SEE A DEF WEAKENING TREND TO PRECIP AS FRONT SLIDES INTO THE ALLEGHENY FRONT AND CENTRAL MTNS. INTERESTING FEATURE FIRST HINTED AT BY THE LAST COUPLE RUNS OF THE HRRR /AND LIKELY WELL OVERDONE BY HRRR/ AND ON DISPLAY IN THE WV IS A VERY SUBTLE SHORTWAVE SLIDING FROM THE SOUTHERN TIP OF ILLINOIS AT 10Z TO SE OHIO AT 17Z BEGINNING TO SHOW SOME ENHANCED CLOUD HEIGHTS IN A NARROW DEFORMATION ZONE. THIS FEATURE WILL SLIDE NE IN QUICK MID-LEVEL FLOW OVER NEXT SEVERAL HOURS AND SHOULD BE ENOUGH TO KICK START SOME TSTMS OVER W PA WHERE CAPES ARE ONLY AROUND 500J/KG. IT REMAINS A BIT UNCLEAR JUST HOW FAR EAST OF A LINE FROM ABOUT BEDFORD TO STATE COLLEGE TO WILLIAMSPORT THE RAIN WILL MANAGE TO GET BEFORE PETERING OUT THOUGH...SO HELD ONTO SCT POPS THERE...RAMPING POPS HIGHER HEADING INTO NW MTNS. DID HOLD TSTM PROBS IN THE SCT CATEGORY...WITH FAST FLOW NOT TOTALLY RULING OUT AN ISOLATED STRONGER WIND GUST THERE /AS NOTED IN THE SPC DAY1 DISCUSSION CONCERNING A MARGINAL RISK/. WE`LL EEK OUT ONE MORE WARM DAY AHEAD OF THE COLD FRONT WITH HIGHS IN THE MID 70S TO MID 80S MOST LOCALES...WITH A SSW BREEZE OVER WESTERN SECTIONS. A COOL DOWN WILL BEGIN TONIGHT AS HIGH PRESSURE PUSHES QUICKLY INTO THE EASTERN GR LAKES AND SHOVES THE COLD FRONT OFF TO THE SOUTH. LOWS WILL RANGE FROM THE CHILLY MID 40S OVER THE NORTH TO AROUND 60 IN THE SOUTHEAST. OVER AREAS WHERE SKIES CLEAR TONIGHT...FOG SEEMS LIKELY LATE. THE BEST CHANCE WOULD SEEM TO BE OVER THE NORTHERN MOUNTAINS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... CLOUDS WILL SETTLE OFF TO THE SOUTH SUNDAY AS HIGH PRESSURE QUICKLY MOVES INTO NORTHERN PA/SOUTHERN NY. IT WILL BE A MARKEDLY COOLER DAY WITH HIGHS AVERAGING AROUND 10 DEG COOLER THAN TODAY. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... PATCHY FROST IS POSSIBLE OVER THE NORTHWEST VALLEYS AS TEMPERATURES DROP INTO THE MID 30S BY MONDAY MORNING. TEMPERATURES WILL MODERATE AFTER THAT AS AN UPPER TROUGH DRIFTS TOWARD PENNSYLVANIA FROM THE MIDWEST. INCREASING CLOUDS AHEAD OF THIS SYSTEM WILL THEN LEAD TO ISOLATED SHOWERS LATE MONDAY INTO TUESDAY. THE SLOW MOVING UPPER TROUGH DIGS INTO THE SOUTHEAST STATES...ULTIMATELY CLOSING OFF NEAR THE CAROLINA COAST. UNCERTAINTY IN THE FORECAST INCREASES IN THIS PERIOD AS THE SYSTEM MAY STILL BE CLOSE ENOUGH TO THE AREA TO BRING AN EASTERLY WIND AND LOW CLOUD/SHOWER CHANCES. KEPT THINGS DRY FOR THIS TIME THOUGH BUT WILL HAVE TO ADJUST AS THE TRACK OF THE UPPER TROUGH/LOW COMES INTO FOCUS THROUGH EARLY WEEK. && .AVIATION /20Z SATURDAY THROUGH THURSDAY/... VFR AREAWIDE THIS MIDDAY AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WILL GENERATE SHOWERS AND SCT TSTMS ACROSS THE NW MTNS THIS MID/LATE AFTERNOON WITH OCCASIONAL RESTRICTIONS AT KBFD...WITH DIMINISHING CHANCES LATE THIS AFTERNOON INTO EARLY EVENING FROM KAOO-KUNV-KIPT WITH ONLY LOCAL RESTRICTIONS POSS. THE SE WILL REMAIN VFR. FRONT CLEARS THE AREA THIS EVE...WITH NW/N FLOW ARRIVING BEHIND AS HIGH PRESSURE STARTS TO BUILD IN. THIS WILL PRODUCE CIG RESTRICTIONS ACROSS MAINLY NW HALF OF CWA...WITH IFR DEVELOPING AT KBFD-KJST AND MVFR FOR CENTRAL SECTIONS. OUTLOOK... SUN-WED...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/RXR NEAR TERM...LA CORTE/RXR SHORT TERM...LA CORTE LONG TERM...LA CORTE/TYBURSKI AVIATION...MARTIN/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
133 PM EDT SAT SEP 19 2015 .SYNOPSIS... A COLD FRONT WILL MOVE THROUGH THE AREA TODAY. HIGH PRESSURE WILL BRING A RETURN OF NEAR NORMAL DAYTIME TEMPERATURES FOR SUNDAY AND CONTINUE INTO THE MIDDLE OF NEXT WEEK. AN UPPER LEVEL LOW MAY LEAD TO A FEW SHOWERS MONDAY OR TUESDAY OVER THE SOUTHERN MOUNTAINS. && .NEAR TERM /THROUGH TONIGHT/... EARLY THIS AFTERNOON...SURFACE LOW LIFTING OUT OF EASTERN GREAT LAKES WITH TRAILING COLD FRONT PROGRESSING ACROSS OHIO VALLEY /AT 17Z MOVING INTO CENTRAL OH/. THERE IS GOOD AGREEMENT ON THE TIMING OF THE FRONT...ENTERING WESTERN PA SHORTLY AFTER 18Z...AND MOVING INTO THE SUSQ VALLEY AROUND 03Z SUN. CONVECTION ALONG THE COLD FRONT WILL ORGANIZE TO OUR WEST AND ENTER THE NWRN MOUNTAINS DURING THE MID AFTERNOON. TOUGH TO FIND MUCH CAPE FURTHER EAST...SO SHOULD SEE A DEF WEAKENING TREND TO PRECIP AS FRONT SLIDES INTO THE ALLEGHENY FRONT AND CENTRAL MTNS. INTERESTING FEATURE FIRST HINTED AT BY THE LAST COUPLE RUNS OF THE HRRR /AND LIKELY WELL OVERDONE BY HRRR/ AND ON DISPLAY IN THE WV IS A VERY SUBTLE SHORTWAVE SLIDING FROM THE SOUTHERN TIP OF ILLINOIS AT 10Z TO SE OHIO AT 17Z BEGINNING TO SHOW SOME ENHANCED CLOUD HEIGHTS IN A NARROW DEFORMATION ZONE. THIS FEATURE WILL SLIDE NE IN QUICK MID-LEVEL FLOW OVER NEXT SEVERAL HOURS AND SHOULD BE ENOUGH TO KICK START SOME TSTMS OVER W PA WHERE CAPES ARE ONLY AROUND 500J/KG. IT REMAINS A BIT UNCLEAR JUST HOW FAR EAST OF A LINE FROM ABOUT BEDFORD TO STATE COLLEGE TO WILLIAMSPORT THE RAIN WILL MANAGE TO GET BEFORE PETERING OUT THOUGH...SO HELD ONTO SCT POPS THERE...RAMPING POPS HIGHER HEADING INTO NW MTNS. DID HOLD TSTM PROBS IN THE SCT CATEGORY...WITH FAST FLOW NOT TOTALLY RULING OUT AN ISOLATED STRONGER WIND GUST THERE /AS NOTED IN THE SPC DAY1 DISCUSSION CONCERNING A MARGINAL RISK/. WE`LL EEK OUT ONE MORE WARM DAY AHEAD OF THE COLD FRONT WITH HIGHS IN THE MID 70S TO MID 80S MOST LOCALES...WITH A SSW BREEZE OVER WESTERN SECTIONS. A COOL DOWN WILL BEGIN TONIGHT AS HIGH PRESSURE PUSHES QUICKLY INTO THE EASTERN GR LAKES AND SHOVES THE COLD FRONT OFF TO THE SOUTH. LOWS WILL RANGE FROM THE CHILLY MID 40S OVER THE NORTH TO AROUND 60 IN THE SOUTHEAST. OVER AREAS WHERE SKIES CLEAR TONIGHT...FOG SEEMS LIKELY LATE. THE BEST CHANCE WOULD SEEM TO BE OVER THE NORTHERN MOUNTAINS. && .SHORT TERM /SUNDAY/... CLOUDS WILL SETTLE OFF TO THE SOUTH SUNDAY AS HIGH PRESSURE QUICKLY MOVES INTO NORTHERN PA/SOUTHERN NY. IT WILL BE A MARKEDLY COOLER DAY WITH HIGHS AVERAGING AROUND 10 DEG COOLER THAN TODAY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... CONFIDENCE IN THE EXTENDED FORECAST CONTINUES TO DWINDLE WITH EACH PASSING MODE RUN. EARLY IN THE PERIOD...MODELS AGREE IN BRINGING FAIRLY AMPLIFIED UPPER TROUGH THROUGH THE OHIO VALLEY INTO THE NERN US. THE RESULTING SOUTH-SOUTHEAST FLOW SHOULD BRING THE CHANCE OF SOME LIGHT RAINS FOR MONDAY AND POSSIBLY TUESDAY. AT THIS POINT I HAVE FAIRLY LOW CHANCES OF RAIN OVER MUCH OF THE AREA MONDAY AND MAINLY OVER SOUTHERN AREAS INTO TUESDAY. BEFORE THIS HAPPENS HOWEVER...WITH CLEAR SKIES...VERY DRY AIR AND LIGHT WINDS...LOWS OVER THE NWRN MOUNTAINS MONDAY MORNING WILL DROP DOWN INTO THE MIDDLE 30S. MAY SEE THE FIRST FROST OF THE SEASON IN A FEW OF THE NORMAL COLD SHELTERED LOCATIONS. FROM THERE MODEL SOLUTIONS DIVERGE FURTHER. THE ECMWF AND GFS/GEFS ALL SHOW THE UPPER TROUGH CLOSING OFF. WHAT HAPPENS THEN MEANS THE DIFFERENCE BETWEEN A MILD AND DRY REST OF THE WEEK...OR A COLD RAINY ONE. THE GFS/GEFS HAVE TRENDED MUCH FURTHER NORTH WITH THE UPPER LOW...KEEPING AN EXTENDED PERIOD OF MOIST EASTERLY LOW LEVEL FLOW FROM WEDNESDAY INTO FRIDAY. THIS WOULD RESULT IN A PERIOD OF CHILLY WET WEATHER. THE ECMWF ON THE OTHER HAND SETTLES THE LOW DOWN OVER THE SERN STATES AND EVEN TRACKS IT WEST ALONG THE GULF COAST FOR THE WEEKEND. THIS WOULD KEEP US UNDER FAVORABLE RIDGING NORTH OF THE SYSTEM...WITH DRY AND MILD CONDITIONS. I USED OUR SUPERBLENDED MODEL MOS WHICH DOWNPLAYS THE GFS/GEFS PESSIMISM...RESULTING IN A MUCH BRIGHTER FORECAST FROM MID WEEK ONWARD. PRESUMING THE OPTIMISTIC FORECAST VERIFIES...TEMPERATURES WHICH WILL START THE WEEK BELOW NORMAL WILL TREND BACK TO A BIT ABOVE NORMAL BY MID WEEK. && .AVIATION /18Z SATURDAY THROUGH WEDNESDAY/... VFR AREAWIDE THIS MIDDAY AHEAD OF AN APPROACHING COLD FRONT. THE FRONT WILL GENERATE SHOWERS AND SCT TSTMS ACROSS THE NW MTNS THIS MID/LATE AFTERNOON WITH OCCASIONAL RESTRICTIONS AT KBFD...WITH DIMINISHING CHANCES LATE THIS AFTERNOON INTO EARLY EVENING FROM KAOO-KUNV-KIPT WITH ONLY LOCAL RESTRICTIONS POSS. THE SE WILL REMAIN VFR. FRONT CLEARS THE AREA THIS EVE...WITH NW/N FLOW ARRIVING BEHIND AS HIGH PRESSURE STARTS TO BUILD IN. THIS WILL PRODUCE CIG RESTRICTIONS ACROSS MAINLY NW HALF OF CWA...WITH IFR DEVELOPING AT KBFD-KJST AND MVFR FOR CENTRAL SECTIONS. OUTLOOK... SUN-WED...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...LA CORTE/RXR NEAR TERM...LA CORTE/RXR SHORT TERM...LA CORTE LONG TERM...LA CORTE AVIATION...MARTIN/RXR
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1231 PM CDT SAT SEP 19 2015 .UPDATE...LATEST HRRR CONTINUES TO PAINT A VERY SKIMPY PRECIP PATTERN OVER THE MID STATE THIS AFTERNOON AND EVENING. SO, WILL LEAVE OUR LOW POP FCST IN PLACE. SHORTLY AFTER NOON, AREA RADARS SHOWED ISOLATED SHOWERS IMMEDIATELY BEHIND THE FRONT OVER NORTHWESTERN TENNESSEE. SINCE CLOUDS ARE RELATIVELY HIGH AND THIN AHEAD OF THE FRONT, TEMPS ARE WARMING NICELY IN THE W-SWLY PRE- FRONTAL FLOW. THUS, HAVE ADJUSTED MAX TEMP EXPECTATIONS UP A FEW DEGS FOR THIS AFTERNOON OVER SOUTHERN AND EASTERN AREAS (INCLUDING THE NASHVILLE AREA). NEW SUITE OF PRODUCTS, REFLECTING THESE UPDATES, HAS ALREADY BEEN ISSUED. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 90 62 80 59 / 20 20 10 10 CLARKSVILLE 84 58 78 54 / 30 10 10 10 CROSSVILLE 83 62 77 57 / 10 20 20 10 COLUMBIA 90 63 80 58 / 20 20 10 10 LAWRENCEBURG 88 63 80 59 / 10 20 10 10 WAVERLY 86 59 78 56 / 20 10 10 10 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 19
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1258 PM CDT SAT SEP 19 2015 .AVIATION... /18Z TAFS/ COLD FRONT HAS MOVED THROUGH MOST OF THE MAJOR AIRPORTS SO FAR THIS AFTERNOON WITH THE EXCEPTION OF WACO...ALTHOUGH THE FRONT IS NOT VERY STRONG AND THE BOUNDARY MAY ACTUALLY WOBBLE A BIT THROUGH THE EARLY AFTERNOON. NORTHERLY FLOW DOES PREVAIL AT THIS TIME IN THE METROPLEX AND THAT SHOULD REMAIN THROUGH TONIGHT. MOST OF THE EARLIER CONVECTION HAS WEAKENED SUBSTANTIALLY OVER THE LAST 2 HOURS BUT THERE IS STILL AN AREA OF RAIN THAT EXTENDS FROM DFW NORTHEAST TO PARIS. NEW CONVECTION HAS BEGUN TO DEVELOP SOUTHWEST OF THE METROPLEX IN MORE UNSTABLE AIR ALONG THE FRONTAL BOUNDARY. THIS WILL LIKELY BE WHERE MOST OF THE CONVECTIVE ACTIVITY WILL BE THROUGH THIS AFTERNOON. AT THIS TIME...WILL PREVAIL VFR CONDITIONS AT THE MAJOR AIRPORTS ALTHOUGH THERE ARE SOME MVFR CIGS JUST TO THE NORTHWEST. THINKING IS THAT THESE WILL SCATTER OUT THROUGH THE AFTERNOON. WINDS ARE EXPECTED TO BE NORTH/NORTHEAST THROUGH THIS EVENING THEN BECOME LGT/VAR OVERNIGHT. THE FRONT IS NOT EXPECTED TO MAKE IT THROUGH WACO AT THIS TIME...SO WILL KEEP SOUTHERLY FLOW IN PLACE THERE. DUNN && .UPDATE... BASED ON CURRENT RADAR TRENDS...HAVE UPDATED POPS FOR TODAY TO ACCOUNT FOR THE MORE WIDESPREAD COVERAGE OF SHOWERS AND STORMS IN THE NORTHEAST ZONES AND MORE SCATTERED COVERAGE OUT WEST. EXPECT THE COLD FRONT TO STALL AND BECOME LESS DEFINED THIS AFTERNOON...BUT SCATTERED SHOWERS AND STORMS WILL STILL BE POSSIBLE NEAR THIS BOUNDARY AS THE DAY PROGRESSES. AJS && .PREV DISCUSSION... /ISSUED 240 AM CDT SAT SEP 19 2015/ THE COLD FRONT WAS LOCATED ALONG A LINE FROM FORT SMITH TO SOUTH OF LUBBOCK AT 07Z/2AM AND MOVING SOUTHEAST NEAR 18 MPH. AN OUTFLOW BOUNDARY AHEAD OF CONVECTION ALONG/BEHIND THE FRONT WILL WORK THROUGH THE NORTHWEST HALF OF THE CWA THIS MORNING WITH CONVECTION SPREADING SOUTHEASTWARD AS WELL. THE HRRR AND TT WRF SPREAD CONVECTION INTO THE NORTHWEST HALF OF THE DFW METROPLEX 10-12Z SO HAVE MAINTAINED CHANCE POPS OVER THE NORTHWEST HALF TODAY. THE FRONT WILL LIKELY MOVE TO NEAR A PALESTINE TO GOLDTHWAITE LINE BY MIDNIGHT TONIGHT...THEN DRIFT NORTHWARD A LITTLE EARLY SUNDAY AND STALL OUT JUST SOUTH OF I-20 DURING THE DAY WITH THE BEST CHANCE OF CONVECTION GENERALLY NORTH OF THE FRONT. THE WEST END OF THE FRONT LIFTS NORTHWARD ON SUNDAY NIGHT AND THEN THE ENTIRE FRONT LIFTS OUT NORTHEAST ON MONDAY. SUNDAY NIGHT POPS WILL SHIFT TO THE NORTHEAST COUNTIES AND MONDAY POPS WILL BE MAINLY OVER THE FAR EASTERN COUNTIES. SOME STRONG THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING DUE TO A FAIR AMOUNT OF INSTABILITY ALONG THE FRONT....AND LOCALIZED HEAVY RAINFALL IS ALSO POSSIBLE DUE TO PWATS NEAR/AROUND 2 INCHES. HIGH TEMPERATURES TODAY WILL NOT CHANGE AHEAD OF THE FRONT BUT THEY WILL BE 5-10 DEGREES COOLER BEHIND IT. AS THE FRONT BECOMES DIFFUSED ON SUNDAY AND LIFTS OUT ON MONDAY...HIGH TEMPS WILL CREEP UPWARD WITH MOST OF THE CWA BACK IN THE LOWER TO MID 90S TUESDAY THROUGH FRIDAY. HAVE ADJUSTED OVERNIGHT LOWS DOWN 1-3 DEGREES...MAINLY RURAL AREAS...THURSDAY AND FRIDAY DUE TO DRIER AIR SPREADING INTO THE REGION. LOOKING AHEAD INTO NEXT WEEKEND AND THE LAST WEEK OF SEPTEMBER...BOTH THE GFS AND ECMWF MODELS ARE INDICATING A WEAKNESS ALOFT OVER THE SOUTHEAST OR SOUTHERN STATES AND THE UPPER RIDGE OFF TO OUR WEST. THIS PATTERN WOULD RESULT IN LOWER HEIGHTS ALOFT OVER NORTH AND CENTRAL TEXAS...AND THUS TEMPERATURES A LITTLE CLOSER TO NORMAL WITH HIGHS IN THE MID 80S TO LOWER 90S. 75 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 88 72 90 72 92 / 40 30 20 10 5 WACO, TX 93 70 95 71 93 / 10 10 10 5 5 PARIS, TX 87 67 87 66 87 / 50 20 30 30 20 DENTON, TX 87 69 89 68 91 / 50 40 20 20 5 MCKINNEY, TX 88 69 90 69 90 / 50 30 20 20 10 DALLAS, TX 89 73 90 71 92 / 40 30 20 10 5 TERRELL, TX 91 69 91 69 91 / 30 20 20 20 10 CORSICANA, TX 94 71 93 71 92 / 10 10 10 5 10 TEMPLE, TX 93 69 93 70 92 / 10 10 5 5 5 MINERAL WELLS, TX 87 67 90 68 91 / 40 40 20 10 5 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1244 PM CDT SAT SEP 19 2015 .DISCUSSION...UPDATED FOR LATEST /18Z/ AVIATION DISCUSSION BELOW. && .AVIATION...ASIDE FROM THE FIRST FEW HOURS OF THE FORECAST...STRAIGHTFORWARD SITUATION UPCOMING THROUGH MIDDAY SUNDAY. EVEN WITH VERY DRY AIR ALOFT...THERE WAS ENOUGH MOISTURE THROUGH 700 MB (WHICH SEEMS TO BE THE MAGIC FORMULA SOMETIMES) FOR SCATTERED BUT LOCALLY HEAVY SHOWERS NEARBY AND OVER KBRO AND KHRL. UNLIKE RECENT DAYS...LOW LEVEL FLOW HAS SLACKENED AND CELLS NOT MOVING ALL THAT MUCH WITH A SLOW WESTWARD DRIFT. SO...HAVE KEPT MVFR VISIBILITY RAIN AT KBRO THROUGH 3 PM AND ADDED A TEMPO GROUP FOR KHRL FOR THE DEVELOPMENT ALL AROUND THEM. WILL KEEP A CLOSE EYE FOR THUNDER AND IFR VISIBILITY ALONG WITH MVFR CEILINGS AND MAY HAVE TO AMEND AT KHRL. FOR KMFE...DRY AIR DOMINATES AND WITH LITTLE WESTWARD MOTION TODAY HAVE LEFT MENTIONABLE RAIN/VISIBILITY RESTRICTIONS OUT OF THE FORECAST. AFTER THE ACTIVITY CALMS DOWN...SKIES RETURN TO FEW-SCATTERED VFR CUMULUS AND THE USUAL 10-15 KNOT EASTERLY SEA BREEZE ENHANCEMENT WILL SPREAD FROM KHRL/KBRO TO KMFE BY 4-5 PM OR SO. SKIES SHOULD CLEAR OVERNIGHT AND WINDS DROP TOWARD CALM...WITH FAIR WEATHER HIGH MVFR/LOW VFR SCATTERED CUMULUS BY 14/15Z SUNDAY. ATMOSPHERE LOOKS A TAD DRIER SUNDAY SO HAVE LEFT OUT RAIN MENTION AFTER 16Z BUT MAY NEED TO REVIEW WITH LATER FORECASTS. 52/BSG && .PREV DISCUSSION... /ISSUED 633 AM CDT SAT SEP 19 2015/ DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. AVIATION...GENERAL VFR CONDITIONS TO PREVAIL ACROSS THE RIO GRANDE VALLEY AND MUCH OF DEEP SOUTH TEXAS TODAY AND TONIGHT WITH STRONG HIGH PRESSURE RESIDING OVER TEXAS. ONCE AGAIN PATCHY GROUND FOG MAY DEVELOP PRODUCING MVFR VSBY FOR AN HOUR OR LESS THIS MORNING WITH LATEST OBSERVATIONS SHOWING CONDITIONS NOT THAT CONDUCIVE FOR FOG FORMATION. WITH THE FOG HAVING A DIFFICULT TIME FORMING THIS MORNING WILL ONLY MENTION TEMPS CONDITIONS FOR AN HOUR AT KHRL AND KMFE. A FEW SHOWERS LINGER ALONG AND JUST EAST OF THE LOWER TEXAS COAST BUT REMAIN FAR REMOVED FROM THE 3 TERMINALS SITES. A WEAK SEA BREEZE MOVES INLAND TODAY AND MAY SPARK AN ISOLATED SHOWER BUT THE WIDE DISTRIBUTION OF THE SHOWERS SHOULD NOT IMPACT THE TERMINALS AND NO SHWR OR RAIN IS MENTIONED IN THE LATEST TAFS. A LIGHT SOUTHEAST TO EAST WIND TO PREVAIL. PREV DISCUSSION... /ISSUED 401 AM CDT SAT SEP 19 2015/ SHORT TERM /TODAY THROUGH SUNDAY/...500 MB RIDGE WELL ESTABLISHED OVER TEXAS WITH A VERY DRY 700-300MB LAYER IN PLACE ACROSS SOUTH TEXAS. MEAN RH WITHIN THIS LAYER IS BELOW 10 PERCENT WITH THE LOWER 10K FEET STILL EXHIBITING THE TYPICAL RH LEVELS OF 50 TO 80 PERCENT. TIME HEIGHT FORECAST INDICATE SLIGHTLY HIGHER RH LEVELS IN THE LOWER LAYER OVER THE MID RIO GRANDE VALLEY. LIGHT EASTERLY FLOW AND THERMAL GRADIENT TO INITIALIZE A SEA BREEZE THIS AFTERNOON WHICH WILL COMBINE WITH THE SLIGHTLY HIGHER MOISTURE CONTENT TO PRODUCE AN ISOLATED SHOWER OR TWO SOME WHERE BETWEEN INTERSTATE HIGHWAYS 69E AND 69C LATE THIS MORNING AND AFTERNOON. IF THE DRIER MID LEVEL AIR MIXES THROUGH THE LOWER LAYER QUICKER THAN EXPECTED CONVECTION WILL BE VERY DIFFICULT TO DEVELOP AND THE SLIGHT CHANCES WILL EVAPORATE QUICKLY. THE DRY AIR MASS TO REMAIN IN PLACE TONIGHT AND SUNDAY WITH PWAT VALUES LOWERING WELL BELOW MID SEPTEMBER NORMALS WHICH WILL MAINTAIN A RELATIVELY DRY FORECAST. HIGH TEMPERATURES RANGED 3 TO 5 DEGREES ABOVE NORMAL YESTERDAY AND MODEL GUIDANCE CONTINUES TO INDICATED THIS TREND TODAY AND SUNDAY. LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...LOW TO MID LEVEL MOISTURE WILL BE LIMITED ACROSS SOUTH TEXAS SUNDAY AS THE 500MB RIDGE ACROSS NORTHERN MEXICO AND THE WESTERN GULF OF MEXICO CONTINUES TO PROVIDE SUBSIDENCE ACROSS THE AREA. A 500MB TROUGH ACROSS THE EASTERN U.S. ALLOWS THE UPPER LEVEL RIDGE TO SHIFT SLIGHTLY WESTWARD AND AMPLIFY ACROSS THE SOUTH CENTRAL U.S. MONDAY INTO TUESDAY. NORTHERLY FLOW ALOFT WILL CONTINUE TO PROVIDE SUBSIDENCE ACROSS THE AREA. A WEAK COLD FRONT IS EXPECTED TO MOVE ACROSS THE SOUTHEAST U.S. MONDAY INTO TUESDAY BUT THE FRONT IS NOT EXPECTED TO MOVE THROUGH SOUTH TX. THE UPPER LEVEL PATTERN IS PROGGED TO REMAIN SUBSIDENT ACROSS THE STATE THROUGH THE REST OF THE FORECAST PERIOD WITH A 500MB LOW CUTTING OFF FROM THE UPPER LEVEL TROUGH ACROSS THE EASTERN U.S. WEDNESDAY INTO THURSDAY AND THE UPPER LEVEL RIDGE ACROSS THE SOUTH CENTRAL U.S. RETROGRADES WESTWARD ACROSS THE SOUTHWEST U.S. AND AMPLIFIES. WILL CONTINUE NOT TO MENTION RAIN CHANCES THROUGH FRIDAY WITH WARM AND RELATIVELY DRY CONDITIONS PREVAILING THROUGH THE REST OF THE WEEK. MARINE... TODAY THROUGH SUNDAY...WEAK SURFACE HIGH PRESSURE TO RESIDE OVER THE NORTHWEST GULF TODAY SPREADING EASTWARD SUNDAY. LIGHT EAST TO SOUTHEAST WINDS AND A SLOW SUBSIDING SEA IS EXPECTED. SUNDAY NIGHT THROUGH WEDNESDAY...LIGHT EAST TO SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS SUN NIGHT INTO MONDAY AS A WEAK COLD FRONT MOVES ACROSS THE SOUTHEAST UNITED STATES AND STALLS. THE PRESSURE GRADIENT IS EXPECTED TO REMAIN WEAK ACROSS THE WESTERN GULF OF MEXICO TUESDAY WITH HIGH PRESSURE ACROSS THE EASTERN UNITED STATES. LIGHT EAST TO SOUTHEAST WINDS WILL PREVAIL ACROSS THE LOWER TEXAS COAST TUESDAY AND WEDNESDAY. && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WEATHER.GOV/RGV
Area Forecast Discussion National Weather Service Midland/Odessa TX 1241 PM CDT SAT SEP 19 2015 .AVIATION... 18Z TAF issuance. The main aviation concern for the next 24 hours is thunderstorms affecting terminals this afternoon/evening and potentially overnight. Currently have a cold front located near the Pecos River Valley with NE winds and SCT-BKN low cigs to the north of this boundary. Low cigs continue to affect CNM/HOB/MAF but clouds will scatter out shortly over most areas. Showers and storms moving north across far west this morning will continue to move north and potentially affect CNM in the next couple hours. In addition, should see TS activity increase near the front later this afternoon but confidence in timing and specific locations is low, therefore just mentioned TSRA in a TEMPO for a few hours this afternoon at all terminals. Some forecast models indicate thunderstorms lasting well into the night and potentially through early Sunday morning. For now, will hold off on any mention of thunder beyond this evening. Will continue to monitor current radar/satellite trends and amend when needed. Otherwise, VFR conditions are expected to prevail except where TSRA may result in brief periods of low vis. && PREV DISCUSSION... /issued 423 AM CDT SAT SEP 19 2015/ DISCUSSION...As of 4:00 AM CDT Saturday...a brief respite from the heat this weekend. Sfc obs and KMAF radar is indc that a cold front is currently over the Central Permian Basin. A few small thunderstorms are popping up behind the front. There are also a few thunderstorms along the Rio Grande in Northwest Presidio County along the edge of a large MCS centered over portions of Sonora and Chihuahua Mexico. The HRRR and RAP13 hi-res models move the cold front slowly south this morning...stalling near or north of I-10 this aftn. With good low-level convergence and weak mid level impulses the hi-res models bring a good shot of convection along the I-20 corridor this morning...moving south this aftn. The main impacts from the thunderstorms will be locally heavy rain and gusty winds. With the rain potential and cloud cover it will be significantly cooler than yesterday...in fact today should be the coolest day this month. Have continued convective chances tonight with the front over the CWA. The cold front will retreat north/wash out on Sunday as a ridge builds back into the Southern Plains/Rockies. Temps will warm to near seasonal levels on Sunday with a slight chance of thunderstorms. A blocking pattern develops over the CONUS next week with a trough along both coasts and a ridge over the Central US. Shortwaves will ride over the ridge...occasionally flattening it slightly. The Davis Mtns...and even more so the Guadalupe Mtns will be on the eastern edge of any convective activity into mid week. Otherwise...the rest of the CWA will be dry. Even though the center of the H85 thermal ridge will be just west of the CWA expect temps next week to be 5-10 degrees above normal...with widespread low 90s and even a few mid 90s across the lower elevations. Widespread 80s are expected in the Mtns...with upper 80s along the extreme northern portions of the CWA. The latest GFS ensemble forecasts keeps West Texas/Southeast New Mexico dry with above normal temperatures through the end of September and into the first several days of October. Strobin MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && .MAF WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ 27
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
215 PM CDT SAT SEP 19 2015 .SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT) ISSUED AT 215 PM CDT SAT SEP 19 2015 HIGH PRESSURE OVER THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI RIVER VALLEY REGION WAS PRODUCING A PICTURE PERFECT AUTUMN-LIKE DAY ACROSS THE FORECAST AREA WITH SUNNY SKIES AND COMFORTABLY COOL TEMPERATURES IN THE 65-70 DEGREE RANGE. CENTER OF THIS HIGH PRESSURE DRIFTS SLOWLY EAST TOWARD EASTERN IA/WESTERN IL TONIGHT. THIS SETS UP A VERY LIGHT SOUTH/SOUTHWEST SURFACE WIND FLOW ACROSS THE FORECAST AREA....GENERALLY 5 TO 10 MPH. CONCERN WILL BE HOW MUCH THE WIND DECOUPLES IN THE RIVER VALLEYS/BOG COUNTRY OF CENTRAL WI FOR FOG DEVELOPMENT POTENTIAL. RAP BUFKIT DEPICTING FAIRLY LIGHT WINDS IN THE 5-10KT RANGE ALL THE WAY UP TO 500MB WHILE THE NAM SHOWS WINDS OF 10-15KT FROM 300 FEET AND ABOVE. WHILE THE RAP WOULD BE MORE CONDUCIVE FOR DECOUPLING/FOG...THE NAM IS TOO WINDY. BESIDE THE WIND...ANOTHER NEGATIVE FACTOR FOR FOG DEVELOPMENT WILL BE A BATCH OF CIRRUS ASSOCIATED WITH AN UPPER LEVEL TROUGH MOVING INTO THE AREA. IF CIRRUS IS THICK ENOUGH...THIS MAY SHUT DOWN FULL RADIATIONAL COOLING POTENTIAL NEEDED FOR FOG. HAVE TO BELIEVE THERE WILL BE SOME DECOUPLING IN THE RIVER VALLEYS/BOG COUNTRY OF CENTRAL WI FOR AT LEAST PATCHY FOG...SO WILL STICK WITH THIS FOR NOW AND LET THE EVENING FORECASTER ASSESS FURTHER. OTHERWISE...PLAN ON COOL OVERNIGHT LOWS IN THE LOWER 40S ACROSS THE SANDY/BOG COUNTRY OF CENTRAL WI...AND MIDDLE TO UPPER 40S ELSEWHERE. TEMPERATURES SHOULD REBOUND NICELY TO RIGHT AROUND SEASONAL NORMALS SUNDAY AS HIGHS TOP OFF IN THE UPPER 60S TO THE MIDDLE 70S UNDER MOSTLY SUNNY SKIES WITH LIGHT SOUTHERLY WINDS. LOOK FOR THESE LIGHT SOUTHERLY WINDS TO CONTINUE THROUGH SUNDAY NIGHT UNDER MOSTLY CLEAR SKIES WITH OVERNIGHT LOWS IN THE MIDDLE 40S TO THE MIDDLE 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 215 PM CDT SAT SEP 19 2015 SEASONABLY WARM/SOMEWHAT BREEZY MONDAY ON TAP AS HIGH PRESSURE DRIFTS INTO THE GREAT LAKES REGION AND COLD FRONT APPROACHES FROM SOUTHERN CANADA/NORTHERN PLAINS. UNDER MOSTLY SUNNY SKIES...PLAN ON HIGHS IN THE LOWER/MIDDLE 70S. FOR MONDAY NIGHT INTO TUESDAY...WILL BE WATCHING THAT COLD FRONT SLOWLY DRIFT SOUTHEAST INTO THE AREA. MODELS SHOWING NARROW BAND OF WEAK 850MB MOISTURE TRANSPORT/BETTER RAIN CHANCES STAYING MAINLY NORTH OF OUR AREA. THERE WILL BE SLIGHT CHANCE OF SHOWERS/ISOLATED THUNDER MAINLY FROM PORTIONS OF SOUTHEAST MN INTO NORTHERN WI ON THE EASTERN PERIPHERY OF THIS MOISTURE TRANSPORT AND WHERE NAM BUFKIT INDICATING CAP MAY BE WEAK ENOUGH TO RELEASE SOME CONVECTION. OTHERWISE...LOOK FOR HIGHS TUESDAY AGAIN WELL INTO THE 70S. FOR TUESDAY NIGHT THROUGH THURSDAY...THE LATEST GFS/ECMWF SHOW A WEAK MID-LEVEL TROUGH PROGRESSING EAST FROM THE NORTHERN PLAINS TOWARD THE UPPER MISSISSIPPI RIVER REGION. THE ECMWF WASHES THIS TROUGH OUT WHILE THE GFS MAINTAINS IT AS IT DRIFTS ACROSS THE REGION. RESULT IS LOW-END SHOWER/THUNDER CHANCES DURING THIS PERIOD. LATEST ECMWF/GFS SHOWING MASSIVE RIDGING OVER THE CENTRAL CONUS/UPPER MISSISSIPPI RIVER VALLEY REGION FRIDAY AND SATURDAY. AS A RESULT...DRIED THIS PERIOD OUT. OTHERWISE...TEMPERATURES FOR WEDNESDAY THROUGH SATURDAY LOOK TO BE CLOSE TO SEASONAL NORMALS IN THE UPPER 60S TO THE UPPER 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1240 PM CDT SAT SEP 19 2015 MOSTLY SUNNY SKIES AND LIGHT NORTHWEST WIND WILL CONTINUE AT KRST/KLSE THROUGH THE AFTERNOON. WINDS WILL SHIFT TO THE SOUTH- SOUTHWEST LATE THIS EVENING AND OVERNIGHT AS SURFACE HIGH PRESSURE OVER OMAHA NE MOVES TOWARD CHICAGO IL. BESIDES SOME INCREASING CIRRUS OVERHEAD TONIGHT...A DRY LOW-MID LEVEL AIR MASS WILL RESULT IN CLEAR SKIES. WESTERLY WINDS AROUND 15 KTS ABOVE THE NOCTURNAL INVERSION WILL PROHIBIT FOG AT KRST. HOWEVER...THE LIGHT WIND LAYER MAY BE DEEP ENOUGH AT KLSE FOR SOME PATCHY FOG. WILL INTRODUCE BCFG AND A LOW SCATTERED CLOUD DECK FROM 20.10Z UNTIL 20.14Z...BUT STILL EXPECT VFR CONDITIONS AT THIS TIME. SUNDAY WILL BE MOSTLY SUNNY WITH LIGHT SOUTHERLY WINDS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...DAS LONG TERM...DAS AVIATION...ROGERS