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
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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
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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