Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/16/13
AREA FORECAST DISCUSSION...UPDATED
NWS SAN JOAQUIN VALLEY - HANFORD CA
315 PM PDT SAT SEP 14 2013
UPDATED AIR QUALITY SECTION
.SYNOPSIS...
A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS NEAR THE SIERRA NEVADA
CREST THROUGH TODAY. OTHERWISE...DRY CONDITIONS WITH NEAR
NORMAL TEMPERATURES FOR THE NEXT FEW DAYS.
&&
.DISCUSSION...
CONVECTIVE CLOUDS COVERING MOST OF THE SOUTHERN SIERRA EARLY THIS
AFTERNOON THOUGH VERY LITTLE PICKED UP BY THE KHNX RADAR. LATEST
OBJECTIVE ANALYSIS FROM SPC INDICATES MINOR INSTABILITY OVER THE
SIERRA CREST AND HRRR RUNS CONTINUE TO GENERATE SOME PRECIPITATION
THROUGH THE EVENING HOURS. CLOUDS AND SHOWERS SHOULD QUICKLY
DISSIPATE AFTER SUNSET. TEMPERATURES ARE A COUPLE OF DEGREES
WARMER THAN THIS TIME YESTERDAY AND MAX TEMPS LOOK GENERALLY ON
TRACK.
BROAD SCALE PATTERN SHIFT WILL UNFOLD OVER THE NEXT FEW DAYS
TOWARD A FAVORING OF TROUGHING OVER THE WEST COAST...A PATTERN
THAT COULD LAST THROUGH THE REMAINDER OF SEPTEMBER. EC AND GFS
ENSEMBLES ARE IN SUPPORT OF THIS THOUGH OF COURSE THE PICTURE GETS
FUSSIER ON THE DETAILS FURTHER OUT /BY THE END OF THE COMING WORK
WEEK/.
THE MINOR AMOUNTS OF MOISTURE OVER OUR FORECAST AREA THIS
AFTERNOON WILL BE BRUSHED EASTWARD TOMORROW BY THE LOW MOVING INTO
THE PAC NW. THIS WILL PUT AN END TO THE AFTERNOON SHOWERS OVER THE
SIERRA. WITH BROAD CYCLONIC FLOW OVER CENTRAL
CALIFORNIA...TEMPERATURES WILL TAKE A MINOR DOWNWARD THROUGH
WEDNESDAY THOUGH REMAIN NEAR TO SLIGHTLY ABOVE NORMAL.
SHORT WAVE RIDGING AHEAD OF A MORE VIGOROUS SHORT WAVE THURSDAY
SHOULD RESULT IN A TEMPORARY UPWARD BUMP IN
TEMPERATURES...TEMPORARY BECAUSE TEMPERATURES WILL COME BACK DOWN
FRIDAY AND COOL SIGNIFICANTLY BY SATURDAY. A LOT OF ERROR
POTENTIAL IN THE FORECAST FRIDAY AS A SLOWER OR FASTER SPEED TO
THE LOW COMING INTO NORCAL COULD MEAN A DIFFERENCE OF 10-15
DEGREES. GOOD MODEL CONSENSUS ON THE EVENTUALLY DEVELOPMENT OF
THIS SYSTEM...WITH THE DETERMINISTIC GFS SHOWING A DISTINCT TREND
TOWARD A DEEPER SOLUTION. DESPITE TIMING DIFFERENCES...COOL AIR
SHOULD BE IN PLACE BY SATURDAY.
THERE WILL BE A CHANCE OF PRECIP IN THE SIERRA WITH THIS LATE WEEK
SYSTEM...ROUGHLY FROM FRESNO COUNTY NORTH. MOISTURE AMOUNTS ARE
NOT SIGNIFICANT AND FLUX VALUES ARE EQUALLY NOT IMPRESSIVE BUT
COULD BE JUST ENOUGH FORCING WITH A STOUT FRONT TO CAUSE SOME
SHOWERS. RIGHT NOW SNOW LEVELS AROUND 10KFT LOOK POSSIBLE...ANY HIGH
ALTITUDE ENTHUSIASTS SHOULD BE AWARE THAT CHANGING WEATHER WILL BE
POSSIBLE BY WEEK/S END.
&&
.AVIATION...
ISOLATED THUNDERSTORMS ARE POSSIBLE NEAR THE SIERRA NEVADA CREST
UNTIL 02Z SUNDAY. AREAS OF MVFR IN SMOKE FROM THE RIM WILDFIRE WILL
PERSIST IN THE VICINITY OF YOSEMITE NATIONAL PARK WITH LOCAL IFR
POSSIBLE. OTHERWISE...VFR CONDITIONS WILL PREVAIL ELSEWHERE IN THE
CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...
SAN JOAQUIN VALLEY...NONE.
TUOLUMNE COUNTY...AIR QUALITY ALERT THROUGH MONDAY SEPTEMBER 16TH.
SEE SFOAQAHNX.
FOR ADDITIONAL INFORMATION...CALL THE TUOLUMNE COUNTY AIR DISTRICT
OFFICE AT 209.533.5693
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 09-14 106:2012 70:1910 72:1937 47:1903
KFAT 09-15 104:1983 74:1982 72:1938 45:1970
KFAT 09-16 105:1937 70:1908 73:1934 49:1955
KBFL 09-14 105:1989 74:2009 79:1971 45:1915
KBFL 09-15 106:1979 75:1959 77:1979 40:1915
KBFL 09-16 109:1929 74:1959 77:1971 42:1915
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...INIGUEZ
AVN/FW...SANGER
SYNOPSIS...WP
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
115 PM PDT SAT SEP 14 2013
.SYNOPSIS...
A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS NEAR THE SIERRA NEVADA
CREST THROUGH TODAY. OTHERWISE...DRY CONDITIONS WITH NEAR
NORMAL TEMPERATURES FOR THE NEXT FEW DAYS.
&&
.DISCUSSION...
CONVECTIVE CLOUDS COVERING MOST OF THE SOUTHERN SIERRA EARLY THIS
AFTERNOON THOUGH VERY LITTLE PICKED UP BY THE KHNX RADAR. LATEST
OBJECTIVE ANALYSIS FROM SPC INDICATES MINOR INSTABILITY OVER THE
SIERRA CREST AND HRRR RUNS CONTINUE TO GENERATE SOME PRECIPITATION
THROUGH THE EVENING HOURS. CLOUDS AND SHOWERS SHOULD QUICKLY
DISSIPATE AFTER SUNSET. TEMPERATURES ARE A COUPLE OF DEGREES
WARMER THAN THIS TIME YESTERDAY AND MAX TEMPS LOOK GENERALLY ON
TRACK.
BROAD SCALE PATTERN SHIFT WILL UNFOLD OVER THE NEXT FEW DAYS
TOWARD A FAVORING OF TROUGHING OVER THE WEST COAST...A PATTERN
THAT COULD LAST THROUGH THE REMAINDER OF SEPTEMBER. EC AND GFS
ENSEMBLES ARE IN SUPPORT OF THIS THOUGH OF COURSE THE PICTURE GETS
FUSSIER ON THE DETAILS FURTHER OUT /BY THE END OF THE COMING WORK
WEEK/.
THE MINOR AMOUNTS OF MOISTURE OVER OUR FORECAST AREA THIS
AFTERNOON WILL BE BRUSHED EASTWARD TOMORROW BY THE LOW MOVING INTO
THE PAC NW. THIS WILL PUT AN END TO THE AFTERNOON SHOWERS OVER THE
SIERRA. WITH BROAD CYCLONIC FLOW OVER CENTRAL
CALIFORNIA...TEMPERATURES WILL TAKE A MINOR DOWNWARD THROUGH
WEDNESDAY THOUGH REMAIN NEAR TO SLIGHTLY ABOVE NORMAL.
SHORT WAVE RIDGING AHEAD OF A MORE VIGOROUS SHORT WAVE THURSDAY
SHOULD RESULT IN A TEMPORARY UPWARD BUMP IN
TEMPERATURES...TEMPORARY BECAUSE TEMPERATURES WILL COME BACK DOWN
FRIDAY AND COOL SIGNIFICANTLY BY SATURDAY. A LOT OF ERROR
POTENTIAL IN THE FORECAST FRIDAY AS A SLOWER OR FASTER SPEED TO
THE LOW COMING INTO NORCAL COULD MEAN A DIFFERENCE OF 10-15
DEGREES. GOOD MODEL CONSENSUS ON THE EVENTUALLY DEVELOPMENT OF
THIS SYSTEM...WITH THE DETERMINISTIC GFS SHOWING A DISTINCT TREND
TOWARD A DEEPER SOLUTION. DESPITE TIMING DIFFERENCES...COOL AIR
SHOULD BE IN PLACE BY SATURDAY.
THERE WILL BE A CHANCE OF PRECIP IN THE SIERRA WITH THIS LATE WEEK
SYSTEM...ROUGHLY FROM FRESNO COUNTY NORTH. MOISTURE AMOUNTS ARE
NOT SIGNIFICANT AND FLUX VALUES ARE EQUALLY NOT IMPRESSIVE BUT
COULD BE JUST ENOUGH FORCING WITH A STOUT FRONT TO CAUSE SOME
SHOWERS. RIGHT NOW SNOW LEVELS AROUND 10KFT LOOK POSSIBLE...ANY HIGH
ALTITUDE ENTHUSIASTS SHOULD BE AWARE THAT CHANGING WEATHER WILL BE
POSSIBLE BY WEEK/S END.
&&
.AVIATION...
ISOLATED THUNDERSTORMS ARE POSSIBLE NEAR THE SIERRA NEVADA CREST
UNTIL 02Z SUNDAY. AREAS OF MVFR IN SMOKE FROM THE RIM WILDFIRE WILL
PERSIST IN THE VICINITY OF YOSEMITE NATIONAL PARK WITH LOCAL IFR
POSSIBLE. OTHERWISE...VFR CONDITIONS WILL PREVAIL ELSEWHERE IN THE
CENTRAL CALIFORNIA INTERIOR DURING THE NEXT 24 HOURS.
&&
.AIR QUALITY ISSUES...
ON SATURDAY SEPTEMBER 14 2013... UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO... KERN... KINGS AND TULARE COUNTIES AND SEQUOIA NATIONAL
PARK AND FOREST.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 09-14 106:2012 70:1910 72:1937 47:1903
KFAT 09-15 104:1983 74:1982 72:1938 45:1970
KFAT 09-16 105:1937 70:1908 73:1934 49:1955
KBFL 09-14 105:1989 74:2009 79:1971 45:1915
KBFL 09-15 106:1979 75:1959 77:1979 40:1915
KBFL 09-16 109:1929 74:1959 77:1971 42:1915
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
PUBLIC...INIGUEZ
AVN/FW...SANGER
SYNOPSIS...WP
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
811 PM MDT SUN SEP 15 2013
.UPDATE...
ISSUED AT 809 PM MDT SUN SEP 15 2013
QUICK UPDATE TO INCORPORATE LATEST OBS DATA INTO GRIDDED DATABASE.
ALSO...WITH THE AMOUNT OF ONGOING CONVECTION PERSISTING ACROSS THE
CWA...OPTED TO EXTEND THE FLASH FLOOD WATCH FOR EL PASO AND TELLER
COUNTIES UNTIL MIDNIGHT TONIGHT. MOORE
UPDATE ISSUED AT 535 PM MDT SUN SEP 15 2013
UPDATED GRIDS FOR LATEST TRENDS. HEAVIEST RAIN BEGINNING TO WIND
DOWN. HRRR INDICATES SHOWERS DEVELOPING FROM UPPER ARKANSAS SEWD
TO THE RATON WILL SLOWLY MOVE TO THE NE OVER THE NEXT 3-4 HOURS.
THEN...SHOULD WIND DOWN OVERNIGHT WITH JUST SOME ISOLD SHOWERS
AND PC FG TO DEAL WITH MON MORNING. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 231 PM MDT SUN SEP 15 2013
...FLASH FLOOD AND HEAVY RAIN THREAT INTO TONIGHT...
BUSY DAY TODAY...AND STILL A WAYS TO GO BEFORE WE ARE OUT OF THE
WOODS FROM THE FLOODING THREAT. HEAVIEST CONVECTION SO FAR HAS BEEN
IN A GROUP OF STRONG STORMS OVER THE ERN AND SRN PORTIONS OF KCOS.
SOME TWO PLUS INCH RAINFALL AMTS THERE...CONTRIBUTING TO URBAN
STREET FLOODING. IT LOOKS LIKE THE STRONGER CONVECTION SHOULD
GRADUALLY BUILD SOUTH OF THE PIKES PK REGION LATER THIS
AFTERNOON...BUT IT WILL BE CLOSE...WITH KCOS AND THE WALDO AREA ON
THE N SIDE OF A NW-SE ORIENTED BOUNDARY THAT RUNS THROUGH SE CO.
THIS IS WHERE THE HEAVIEST CONVECTION IS EXPECTED TO BUILD THROUGH
THE FIRST HALF OF THIS EVENING. WITH SLOW STORM MOVEMENT AND VERY
EFFICIENT PRECIP RATES...WILL CONTINUE TO SEE THE POTENTIAL FOR
LOCALIZED FLASH FLOODING THROUGH THIS TIME.
THE GOOD NEWS IS THAT THINGS SHOULD START TO IMPROVE ON MONDAY.
HEAVIEST SHOWERS SHOULD WIND DOWN BY MIDNIGHT TONIGHT. SOME SCT
SHOWERS EARLY MONDAY...ALONG WITH AREAS OF FG OR BR...THEN SOME
PARTIAL CLEARING BY LATE MORNING INTO THE AFTERNOON. WITH SOME MORE
SUN...COULD SEE ISOLD-SCT SHOWERS OR STORMS REDEVELOP BY
AFTERNOON...BUT SHOULD NOT SEE THE PROBLEMS THAT WE HAVE SEEN TODAY.
TEMPS TOMORROW ALSO STARTING TO REBOUND...WITH HIGHS IN THE MID
70S FOR THE PLAINS. ROSE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 231 PM MDT SUN SEP 15 2013
...DRYING TREND...
A DRYING TREND WILL BE IN FULL SWING BY TUESDAY...AS A DRIER
WESTERLY FLOW TAKES OVER. THERE WILL STILL BE A COUPLE ROUNDS OF
SHOWERS AND THUNDERSTORMS TO MOVE THROUGH TUESDAY AND WEDNESDAY...BUT
THESE SHOULD MAINLY AFFECT THE MOUNTAINS AND THE CONCERN FOR HEAVY
RAIN WILL BE MUCH LOWER THAN IN RECENT DAYS.
THURSDAY AND FRIDAY ACTUALLY LOOK DRY OVER THE MOUNTAINS AT THIS
POINT...BUT A LOW LEVEL BOUNDARY MAY BACK UP TO THE EASTERN
MOUNTAINS AND PLAINS BRINGING A FEW SHOWERS OR STORMS TO THOSE
AREAS LATE THURSDAY INTO EARLY FRIDAY.
SATURDAY AND SUNDAY...THE FOCUS FOR SHOWERS AND STORMS SHIFTS
BACK TO MAINLY THE MOUNTAINS AGAIN...BUT STILL NOT GREAT COVERAGE
OR RAINFALL AMOUNTS.
THE PRIMARY STORM THREATS TUESDAY THROUGH SUNDAY WILL PROBABLY BE
MORE IN THE LINES OF LIGHTNING AND GUSTY WINDS THAN ANYTHING ELSE.
ALSO...TEMPERATURES WILL BE SHIFTING BACK TO AT OR ABOVE SEASONAL
AVERAGES DURING THE PERIOD. LW
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 231 PM MDT SUN SEP 15 2013
GREATEST POTENTIAL FOR TS AND MVFR-IFR CONDITIONS AT THE TERMINALS
WILL CONTINUE THROUGH ABOUT 03Z. THEN GRADUAL IMPROVEMENT
OVERNIGHT...ALTHOUGH THERE WILL LIKELY BE LOW CIGS AND POSSIBLY
SOME LOCALIZED FG/BR THROUGH 14-16Z MON MORNING. THEN...VFR
EXPECTED WITH JUST ISOLD-SCT SHOWERS/TS ON MONDAY. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ081-084-085.
&&
$$
UPDATE...MOORE
SHORT TERM...ROSE
LONG TERM...LW
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
538 PM MDT SUN SEP 15 2013
.UPDATE...
ISSUED AT 535 PM MDT SUN SEP 15 2013
UPDATED GRIDS FOR LATEST TRENDS. HEAVIEST RAIN BEGINNING TO WIND
DOWN. HRRR INDICATES SHOWERS DEVELOPING FROM UPPER ARKANSAS SEWD
TO THE RATON WILL SLOWLY MOVE TO THE NE OVER THE NEXT 3-4 HOURS.
THEN...SHOULD WIND DOWN OVERNIGHT WITH JUST SOME ISOLD SHOWERS
AND PC FG TO DEAL WITH MON MORNING. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 231 PM MDT SUN SEP 15 2013
...FLASH FLOOD AND HEAVY RAIN THREAT INTO TONIGHT...
BUSY DAY TODAY...AND STILL A WAYS TO GO BEFORE WE ARE OUT OF THE
WOODS FROM THE FLOODING THREAT. HEAVIEST CONVECTION SO FAR HAS BEEN
IN A GROUP OF STRONG STORMS OVER THE ERN AND SRN PORTIONS OF KCOS.
SOME TWO PLUS INCH RAINFALL AMTS THERE...CONTRIBUTING TO URBAN
STREET FLOODING. IT LOOKS LIKE THE STRONGER CONVECTION SHOULD
GRADUALLY BUILD SOUTH OF THE PIKES PK REGION LATER THIS
AFTERNOON...BUT IT WILL BE CLOSE...WITH KCOS AND THE WALDO AREA ON
THE N SIDE OF A NW-SE ORIENTED BOUNDARY THAT RUNS THROUGH SE CO.
THIS IS WHERE THE HEAVIEST CONVECTION IS EXPECTED TO BUILD THROUGH
THE FIRST HALF OF THIS EVENING. WITH SLOW STORM MOVEMENT AND VERY
EFFICIENT PRECIP RATES...WILL CONTINUE TO SEE THE POTENTIAL FOR
LOCALIZED FLASH FLOODING THROUGH THIS TIME.
THE GOOD NEWS IS THAT THINGS SHOULD START TO IMPROVE ON MONDAY.
HEAVIEST SHOWERS SHOULD WIND DOWN BY MIDNIGHT TONIGHT. SOME SCT
SHOWERS EARLY MONDAY...ALONG WITH AREAS OF FG OR BR...THEN SOME
PARTIAL CLEARING BY LATE MORNING INTO THE AFTERNOON. WITH SOME MORE
SUN...COULD SEE ISOLD-SCT SHOWERS OR STORMS REDEVELOP BY
AFTERNOON...BUT SHOULD NOT SEE THE PROBLEMS THAT WE HAVE SEEN TODAY.
TEMPS TOMORROW ALSO STARTING TO REBOUND...WITH HIGHS IN THE MID
70S FOR THE PLAINS. ROSE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 231 PM MDT SUN SEP 15 2013
...DRYING TREND...
A DRYING TREND WILL BE IN FULL SWING BY TUESDAY...AS A DRIER
WESTERLY FLOW TAKES OVER. THERE WILL STILL BE A COUPLE ROUNDS OF
SHOWERS AND THUNDERSTORMS TO MOVE THROUGH TUESDAY AND WEDNESDAY...BUT
THESE SHOULD MAINLY AFFECT THE MOUNTAINS AND THE CONCERN FOR HEAVY
RAIN WILL BE MUCH LOWER THAN IN RECENT DAYS.
THURSDAY AND FRIDAY ACTUALLY LOOK DRY OVER THE MOUNTAINS AT THIS
POINT...BUT A LOW LEVEL BOUNDARY MAY BACK UP TO THE EASTERN
MOUNTAINS AND PLAINS BRINGING A FEW SHOWERS OR STORMS TO THOSE
AREAS LATE THURSDAY INTO EARLY FRIDAY.
SATURDAY AND SUNDAY...THE FOCUS FOR SHOWERS AND STORMS SHIFTS
BACK TO MAINLY THE MOUNTAINS AGAIN...BUT STILL NOT GREAT COVERAGE
OR RAINFALL AMOUNTS.
THE PRIMARY STORM THREATS TUESDAY THROUGH SUNDAY WILL PROBABLY BE
MORE IN THE LINES OF LIGHTNING AND GUSTY WINDS THAN ANYTHING ELSE.
ALSO...TEMPERATURES WILL BE SHIFTING BACK TO AT OR ABOVE SEASONAL
AVERAGES DURING THE PERIOD. LW
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 231 PM MDT SUN SEP 15 2013
GREATEST POTENTIAL FOR TS AND MVFR-IFR CONDITIONS AT THE TERMINALS
WILL CONTINUE THROUGH ABOUT 03Z. THEN GRADUAL IMPROVEMENT
OVERNIGHT...ALTHOUGH THERE WILL LIKELY BE LOW CIGS AND POSSIBLY
SOME LOCALIZED FG/BR THROUGH 14-16Z MON MORNING. THEN...VFR
EXPECTED WITH JUST ISOLD-SCT SHOWERS/TS ON MONDAY. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR COZ081-084-085.
&&
$$
UPDATE...ROSE
SHORT TERM...ROSE
LONG TERM...LW
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1115 PM MDT FRI SEP 13 2013
.UPDATE...
ISSUED AT 1105 PM MDT FRI SEP 13 2013
QUICK UPDATE TO INCORPORATE LATEST OBS DATA AND RADAR IMAGERY
TRENDS. INTRODUCED AREAS OF FOG OVERNIGHT FOR MUCH OF THE FORECAST
AREA BETWEEN MIDNIGHT AND 8 AM. CUT BACK POPS CONSIDERABLY...BUT
WITH SOME MUCH MOISTURE LINGERING FOUND IT HARD TO CUT POPS
TOTALLY. BEST AREA FORSOME OVERNIGHT CONVECTION STILL LOOKS TO BE
ALONG THE CONTDVD. MOORE
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 335 PM MDT FRI SEP 13 2013
TONIGHT...NEXT DISTURBANCE IS MOVING NORTHEAST ACROSS THE CWA.
LINE OF CONVECTION HAS DEVELOPED OVER BENT AND EASTERN LAS ANIMAS
COUNTY AND IT IS MOVING TO THE NORTHEAST AT 25 TO 35 KNOTS. THE 12Z
AND 18Z NAM SUGGESTED THE HEAVIEST PRECIPITATION WOULD MOVE ACROSS
THE EASTERN PLAINS. SO FAR...THE CELLS HEADING TOWARDS EL PASO AND
TELLER COUNTIES ARE WEAK. HRRR HAS NOT BEEN DOING WELL TODAY...AS
18Z HRRR HAS MUCH MORE CONVECTION OVER EL PASO COUNTY AT THIS TIME.
BELIEVE THE NAM AND GFS HAS A BETTER HANDLE ON CONVECTION. WILL NOT
ISSUE A FLASH FLOOD WATCH FOR EL PASO AND TELLER COUNTIES THIS
EVENING...AS CHANCES FOR SLOWER MOVING CELLS WITH HEAVY RAINFALL IS
LOW. CANNOT TOTALLY RULE OUT A STRONG CELL OVER A BURN SCAR...BUT
CHANCES OF THIS HAPPENING ARE SMALL. CONVECTION OF THE CWA WILL
MOSTLY END BY MID EVENING. KEPT POPS OVERNIGHT AS SOME SHOWERS ARE
POSSIBLE WITH ABUNDANT MOISTURE AND CYCLONIC FLOW.
SATURDAY...TROUGH APPROACHES THE REGION FROM THE SOUTHWEST...AND
FLOW ALOFT TURNS MORE TO THE SOUTHWEST. STILL PLENTY OF MOISTURE
WITH BUFKIT SOUNDINGS SHOWING PRECIPITABLE WATERS OF 8 TENTHS OF AN
INCH AND GREATER. MAIN CHALLENGE FOR CONVECTION IS THE AMOUNT OF
INSTABILITY. NAM AND GFS SUGGEST THE GREATEST INSTABILITY WILL BE
OVER AND NEAR THE MOUNTAINS...AND HAVE HIGH SCATTERED TO SOME LIKELY
POPS DURING THE AFTERNOON. GIVEN THE ABUNDANT MOISTURE...SOME
STRONGER STORMS COULD PRODUCE LOCALLY HEAVY RAIN...WHICH COULD CAUSE
PROBLEMS ON THE BURN SCARS. GIVEN THE LACK OF DEEP UPSLOPE AND LACK
OF INSTABILITY...BELIEVE CHANCES FOR FLASH FLOODING OVER BURNS SCARS
AND OTHER SUSCEPTIBLE AREAS IS LOW ENOUGH TO NOT WARRANT A FLASH
FLOOD WATCH. --PGW--
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 335 PM MDT FRI SEP 13 2013
...NEXT HEAVY RAIN THREAT ARRIVES BY SUNDAY MORNING...
OLD UPPER TROUGH OPENS UP AND BEGINS TO MOVE EAST ACROSS COLORADO
SATURDAY. THERE IS STILL ADEQUATE MOISTURE FOR STORMS TO DEVELOP
IN THE AFTERNOON...BUT WITH THE TROUGH OPENING UP...THERE DOESN`T
SEEM TO BE ANYTHING TO REALLY FOCUS THE ENERGY AND GET ANYTHING
WIDESPREAD GOING. SO...GENERALLY ISOLATED TO SCATTERED COVERAGE OF
STORMS SATURDAY...MAINLY OVER THE MOUNTAINS. HEAVY RAIN POTENTIAL
WILL STILL EXIST...BUT AGAIN...MORE HIT AND MISS THAN IN RECENT
DAYS.
ON SUNDAY...WE WILL HAVE SOMETHING TO FOCUS THE PRECIPITATION
AGAIN. SUNDAY MORNING...AND POSSIBLY EVEN LATE SATURDAY NIGHT...
WE WILL HAVE A RATHER SIGNIFICANT COOL FRONT MOVE THROUGH THE
EASTERN PLAINS...ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
THE CENTRAL UNITED STATES. THE COOL FRONT WILL FORCE UPSLOPE
FLOW AGAINST THE MOUNTAINS...TRIGGERING FAIRLY WIDESPREAD
PRECIPITATION...WITH EMBEDDED CONVECTION...FOR LOCALLY HEAVIER
PRECIP. SO...THIS DAY WILL BE A HIGH THREAT DAY AGAIN FOR
AREA BURN SCARS. AND...WITH THE RECENT SATURATION THAT HAS
OCCURRED...OTHER AREAS COULD SEE SOME PROBLEMS AS WELL. THIS
WILL LAST INTO SUNDAY NIGHT...MAINLY AFFECTING THE EASTERN
MOUNTAINS AND PLAINS.
MONDAY...WE START TO FINALLY TRANSITION OUT OF THIS PATTERN
INTO A MUCH DRIER ONE. COULD STILL BE SOME SPOTTY STUFF
AROUND TO CONTEND WITH MONDAY...BUT THE REST OF THE WEEK
DEFINITELY LOOKS MUCH DRIER AND WARMER AS A MUCH DRIER
WESTERLY FLOW ALOFT TAKES HOLD OVER COLORADO. LW
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1105 PM MDT FRI SEP 13 2013
VFR CONDITIONS EXPECTED FOR KPUB THROUGH 21Z SAT...THEN ISOLATED
CONVECTION IN VCNTY. INTRODUCED AREAS OF FOG FOR BOTH KALS AND
KCOS TONIGHT FROM MIDNIGHT THROUGH AROUND 8 AM SAT MORNING. SE SFC
FLOW AT KCOS WILL KEEP MVFR CONDITIONS IN PLACE THROUGH THE
NIGHT...WITH CIGS AND VSBY IMPROVING AFTER 16Z TOMORROW. ISOLATED
TO SCATTERED CONVECTION FORECAST SAT AFTN AFTER 18Z...MAINLY TIED
TO THE HIGHER TERRAIN.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOORE
SHORT TERM...PGW
LONG TERM...LW
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1127 AM EDT SAT SEP 14 2013
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OVER THE GREAT LAKES WILL MOVE SOUTHEAST AND
PASS THROUGH THE FORECAST AREA TONIGHT AND INTO THE WESTERN ATLANTIC
ON SUNDAY. A COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY NIGHT INTO
MONDAY MORNING. ANOTHER HIGH PRESSURE SYSTEM WILL MOVE ACROSS THE
AREA TUESDAY INTO WEDNESDAY BEFORE HEADING SLOWLY OFFSHORE
THURSDAY INTO FRIDAY AS A COLD FRONT STARTS MOVING THROUGH THE
GREAT LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAD TO DO A QUICK UPDATE ON TEMPERATURES AND SKY COVER GIVEN THE
EXTENT AND THICKNESS OF THE STRATOCU. THE LATEST RUC SHOWS THAT
THE MID-LEVEL TROUGH AND ASSOCIATED COLD POOL ARE STILL OVERHEAD
AND ONLY SLOWLY PULLING TOWARDS OUR EAST. 500MB TEMPERATURES ARE
AROUND -18C ALLOWING THE CLOUDS TO CONTINUE TO FORM UNDERNEATH THE
INVERSION. THE THICKER CLOUDS HAVE ALSO KEPT TEMPERATURES COOLER
THAN EXPECTED THIS LATE IN THE MORNING SO WE HAVE KNOCKED DOWN
TODAYS HIGHS BY A FEW DEGREES ACROSS OUR NORTHERN AND WESTERN
ZONES. STILL EXPECT A GRADUAL THINNING AND LIFTING THE STRATOCU
THIS AFTERNOON AS THE COLD POOL MOVES OFF. WE WILL ALSO BEGIN TO
LOSE THE GUSTIER NORTHWEST WINDS AS THE INVERSION ALOFT DEEPENS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
THE CENTER OF THE SURFACE HIGH WILL PARK ITSELF ACROSS THE CWA
TONIGHT. WINDS WILL DIMINISH AND GO CALM IN MANY SPOTS. IN THE
MID-LEVELS, A FAST ZONAL FLOW WILL DEVELOP FROM THE UPPER PLAINS TO
THE EAST COAST. WE COULD SEE SOME HIGH LEVEL CLOUDS TOWARD MORNING,
BUT THEY AREN`T EXPECTED TO AFFECT ANY SENSIBLE WEATHER.
TEMPERATURES WILL BACK INTO THE 40S ACROSS MANY LOCALES. METRO
PHILLY WILL PROBABLY SETTLE BACK INTO THE LOWER 50S. SOME UPPER 30S
CAN BE EXPECTED ACROSS THE POCONOS AND NORTHWEST NJ. CAN`T RULE OUT
SOME MID 30S, BUT THEY WILL BE ISOLATED. THAT SAID, WE`LL MENTION
SOME PATCHY FROST IN THE GRIDS, BUT NOT ISSUE AN ADVISORY. AT LEAST
OF NOW, THE THINKING IS THERE SIMPLY WON`T BE ENOUGH REAL ESTATE IN
THE MID 30S TO NECESSITATE AN ADVISORY.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A SUBDUED LONG TERM FOR OUR CWA WITH A COLD FRONTAL PASSAGE
SANDWICHED AROUND TWO HIGH PRESSURE SYSTEMS. THE GFS INITIALIZATION
UPSTREAM LOOKED SLIGHTLY BETTER THAN THE WRF-NMMB AT 500MB WITH BOTH
MODELS EARNING A SPLIT DECISION AT 850MB AND 925MB. IF ANYTHING THE
CURRENT TROF IS SLIGHTLY STRONGER AND TRENDING SLOWER THAN WHAT THE
GFS HAS.
WE SHOULD START SEEING SOME CIRRUS ON SUNDAY AS THE HIGH PRESSURE
SYSTEM MOVES OFFSHORE. NOT SURE ABOUT ITS THICKNESS, BUT ENOUGH
THERE BASED ON EXPECTED 925MB TEMPS TO COMPROMISE BETWEEN THE STAT
GUIDANCE FOR HIGHS. WE WERE PRETTY CLOSE TO CONSISTENCY ALSO. WINDS
OVERALL SHOULD BE LIGHT.
WHILE CONVECTIVE PARAMETERS ARE NOT SUPPORTING THUNDER FOR SUNDAY
NIGHT OR MONDAY AND THE FCST ISENTROPIC LIFT IS, WELL, MUTED ABOVE
850MB, OUR CWA WILL BE IN THE ENTRANCE REGION OF THE 250MB JET PLUS
MODERATE MID LEVEL QVEC CONVERGENCE. THE FCST SOUNDINGS ARE SHOWING
SOME CAPPING, BUT WOULD BELIEVE THAT THE FCST SHORT WAVES SHOULD
ERODE THESE MORE THAN THE MODELS ARE INDICATING. OVERALL WE BELIEVE,
THERE REMAINS THE CHANCE FOR SOME MEASURABLE, ALBEIT ON THE LIGHT
SIDE, PRECIPITATION AS THIS FRONT MOVES THROUGH OUR CWA. OUR POPS
ARE HIGHER THAN ANY OF THE STAT GUIDANCE. BECAUSE OF TIMING
DIFFERENCES (CENTERED CLOSE TO 12Z FOR BEST POPS), WE KEPT POPS AS
CHANCE FOR NOW (THE PCPN ITSELF LOOKS LIKELY).
WHILE THE GFS HAS BEEN MORE BULLISH, ITS RUN-TO-RUN CONTINUITY HAS
NOT BEEN THERE WITH THE AFTERNOON SHORT WAVE. THE LATEST ECMWF
OFFERS A COMPROMISE AND WPC WAS NOT THRILLED WITH THE MORE
PROGRESSIVE NAM/UKMET SOLUTIONS. WE DID ADD A LOW CHANCE IN FOR THIS
FEATURE, BUT CONFIDENCE IS NOT HIGH. WOULD THINK THAT CLOUDS WILL
KEEP TEMPS UP ON SUNDAY NIGHT AND LEANED TOWARD THE HIGHER STAT
GUIDANCE. MONDAY READS LIKE A REPEAT OF YESTERDAY. IF WE CAN GET A
PERIOD OF SUNSHINE, TEMPS WILL REBOUND. THE DAYS LENGTH IS NOT WHAT
IT USED TO BE, SO WE WENT A BIT CONSERVATIVE WITH MAX TEMPS.
IT WILL GET COOLER ON MONDAY NIGHT AND TUESDAY AGAIN. WE WILL HAVE
TO WATCH THE EASTERN PART OF OUR CWA WITH THE ONSHORE FLOW. MODELS
ARE FORECASTING IT TO BE PRETTY DRY, BUT WE DO START HAVING PROBLEMS
WITH ONSHORE FLOW AND CLOUDS ONCE SEPTEMBER ROLLS AROUND. AS THE
HIGH MOVES CLOSER TUESDAY NIGHT, ALL DOUBTS WILL CEASE. TUESDAY
NIGHT LOOKS TO BE ANOTHER EXCELLENT RADIATIONAL COOLING NIGHT.
OUR AIR MASS WILL START MODIFYING FOR THE REST OF THE WORK WEEK. THE
LATEST MODEL RUNS ARE NOT SHOWING MUCH (OR LESS) BARK WITH A WEAK WARM
FRONT, SO WE DID REMOVE THE POPS FOR WEDNESDAY NIGHT INTO THURSDAY.
WE KEPT THE POPS IN FOR THURSDAY NIGHT FOR THAT FRONT AND FOR FRIDAY
AS THE NEXT COLD FRONT APPROACHES. THE MODELS ARE FORECASTING MORE
INSTABILITY WITH THIS NEXT FRONT, AND WE DID ADD THE MENTION OF
THUNDER. BY THE END OF THE WORK WEEK TEMPERATURES SHOULD RISE ABOVE
NORMAL AGAIN AFTER A CHILLY MID WEEK PERIOD.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR. THE STRATOCU ACROSS MOST OF OUR TERMINALS SHOULD
BEGIN TO DISSIPATE AND LIFT A BIT BY THE MID-AFTERNOON HOURS. NORTHWEST
WINDS COULD GUST TO AROUND 20 KNOTS THROUGH THE EARLY AFTERNOON
HOURS BEFORE RELAXING A BIT.
TONIGHT...VFR. NORTHWEST WINDS LESS THAN 10 KT. CLEAR SKIES, EXCEPT
MAYBE SOME HIGH CIRRUS TOWARD MORNING.
OUTLOOK...
SUNDAY...VFR. SOME PATCHY MORNING GROUND FOG POSSIBLE AT RURAL
AIRPORTS.
SUNDAY NIGHT INTO MONDAY...MOSTLY VFR THROUGH THE PERIOD. CHANCE OF
SHOWERS SUNDAY NIGHT INTO MONDAY MORNING POSSIBLY PRODUCING MVFR
CONDITIONS.
MONDAY NIGHT INTO WEDNESDAY...VFR. SOME PATCHY MORNING GROUND FOG
POSSIBLE AT RURAL AIRPORTS ON WEDNESDAY MORNING.
&&
.MARINE...
CANCELLED THE SCA EARLY ACROSS THE SOUTHERN WATERS. BUOY 44009 HAS
BEEN BOUNCING AROUND QUITE A BIT THIS MORNING THOUGH NEVER
ACTUALLY REACHING 5 FEET. IT IS POSSIBLE THAT 5 FEET MAY BE
REACHED, BRIEFLY, ACROSS THE SOUTH BUT THE OVERALL TREND IS
DOWNWARD THROUGH THE MORNING AND AFTERNOON HOURS.
NORTHWEST WINDS MAINLY 10-15 KTS AND SEAS ON THE OCEAN 2 TO 4 FT
THIS AFTERNOON AND TONIGHT. COULD SEE SOME 20 KT GUSTS THROUGH THE
AFTERNOON.
OUTLOOK...
THE LONG TERM WILL START WITH SUB SMALL CRAFT ADVISORY CONDITIONS
EXPECTED AS THE HIGH PRESSURE SYSTEM MOVES OFFSHORE. THE COLD
FRONTAL PASSAGE ITSELF IS EXPECTED TO BE TAME LATE SUNDAY INTO
MONDAY.
THE HIGHEST CHANCE FOR SMALL CRAFT ADVISORY CONDITIONS IN THE
OUTLOOK PERIOD COMES MONDAY NIGHT INTO TUESDAY IN THE NORTHERLY FLOW
BEHIND THE FRONT. STAT GUIDANCE HAS BECOME A BIT MORE ROBUST WITH
THE WINDS AND THE WAVE WATCH MODEL BRINGS SEAS TO THE 5 FOOT
THRESHOLD ON THE OCEAN. LESS OF AN OVERALL CHANCE ON DELAWARE BAY.
ONCE THE HIGH PRESSURE SYSTEM SETTLES CLOSER, FIRST THE CHANCE OF
SMALL CRAFT ADVISORY WINDS ON TUESDAY DAY SHOULD CEASE FOLLOWED BY
THE SWELLS BY LATE TUESDAY NIGHT.
GREATER CONFIDENCE OF SUB SMALL CRAFT ADVISORY CONDITIONS ON
WEDNESDAY AS THE HIGH IS FORECAST TO BE CLOSE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI/ROBERTSON
NEAR TERM...HEAVENER/KRUZDLO
SHORT TERM...KRUZDLO
LONG TERM...GIGI
AVIATION...GIGI/KRUZDLO/ROBERTSON
MARINE...GIGI/HEAVENER/KRUZDLO
AREA FORECAST DISCUSSION
NWS MIAMI FL
930 PM EDT SUN SEP 15 2013
.DISCUSSION...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE
NIGHT. THE HRRR SHOWS A SIGNIFICANT INCREASE IN COVERAGE, WHICH
MAY BE OVERDONE AS IT SHOWS ACTIVITY NOT ONLY DEVELOPING, BUT ALSO
MOVING SOUTH FROM PALM BEACH COUNTY. GIVEN THE GENERAL FLOW TO
WEST AND NORTHWEST, NOT THINKING IT IS TOTALLY ACCURATE. HOWEVER,
WITH SOME ADDITIONAL CONVECTION DEVELOPING, POPS WILL BE LEFT AT
CHC FOR THE COAST AND RAISED TO NEAR CHC FOR THE INTERIOR THROUGH
06Z.
&&
.PREV DISCUSSION... /ISSUED 736 PM EDT SUN SEP 15 2013/
AVIATION...
THE EAST COAST TAF SITES WILL SEE EASTERLY WIND FLOW OF 5 TO 10
KNOTS TONIGHT BEFORE INCREASING TO AROUND 10 KNOTS ON MONDAY. THIS
WILL ALLOW FOR SOME SHOWERS AND THUNDERSTORMS TO WORK INTO THE
EAST COAST TAF SITES TONIGHT INTO MONDAY FROM THE ATLANTIC WATERS.
SO WILL CONTINUE WITH THE VCTS FOR THE EAST COAST TAF SITES
TONIGHT INTO MONDAY. HOWEVER...THE START OF THE THREAT OF STORMS
SHOULD BE BETWEEN 3Z AND 4Z FOR KMIA...KOPF...AND KTMB TAF SITES
WHILE REST OF THE EAST COAST TAF SITES WILL SEE THE THUNDERSTORM
THREAT ANYTIME TONIGHT INTO MONDAY.
KAPF TAF SITE WILL ALSO HAVE AN EASTERLY WIND FLOW TONIGHT INTO
MONDAY WITH SPEEDS AT 5 KNOTS OR LESS TONIGHT INCREASING TO AROUND
10 KNOTS BY MONDAY AFTERNOON. KAPF TAF SITE SHOULD REMAIN DRY
TONIGHT BEFORE THE THREAT OF SHOWERS RETURN TO THE TAF SITE BY 13Z
MONDAY AND THUNDERSTORM THREAT BY 17Z MONDAY.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS TONIGHT INTO
MONDAY OVER ALL OF THE TAF SITES...AS ANY SHOWERS OR STORMS THAT
DO TAF SITES WILL BE SHORT LIVE LESS THAN 30 MINUTES. WHEN THE
SHOWERS AND THUNDERSTORM DO AFFECT THE TAF SITES...THE VIS AND
CEILING COULD FALL DOWN INTO THE IFR CONDITIONS AND THIS WILL BE
HANDLE BY A SHORT FUSE TEMPO GROUP.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 232 PM EDT SUN SEP 15 2013/
SYNOPSIS...
DEEP TROPICAL MOISTURE SPREADING NORTHWESTWARD OVER THE AREA WILL
LEAD TO A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS OVER THE NEXT
SEVERAL DAYS.
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
EARLIER CONVECTION IS SPREADING WEST OF THE REGION...AND WITH
LITTLE ADDITIONAL TIME FOR SURFACE HEATING/DESTABILIZATION...RISK
FOR STRONG/SEVERE CONVECTION IS LOW FOR THE REMAINDER OF THE AFTERNOON.
THE NORTH ATLANTIC RIDGE WILL CONTINUE MOVING NORTH AS ANOTHER RIDGE
LOCATED OVER THE GULF STATES WILL CONTINUE MOVING EAST TOWARDS THE
FLORIDA PENINSULA. THESE FEATURES WILL ALLOW FOR THE WIND FLOW TO
PREVAIL FROM THE EAST ACROSS OUR AREA...KEEPING OUR ATMOSPHERE HUMID AND
WARM. WITH THIS...SUMMER-TYPE AFTERNOON CONVECTION IS EXPECTED
THROUGH AT LEAST MID WEEK...WITH HIGHER COVERAGE ACROSS THE INTERIOR
AND WEST.
LONG TERM ...
MODELS SHOW MID LEVEL HIGH PRESSURE OVER THE CENTRAL GULF STATES,
LEADING TO MORE OF A NORTHWEST FLOW ALOFT IN COMBINATION WITH
CONTINUED E/NE LOW LEVEL WINDS. EARLIER RUNS OF THE ECMWF WERE
SHOWING A MID-LEVEL LOW CUTTING OFF OVER THE EASTERN GULF OF
MEXICO, BUT THE LATEST RUN OF THE ECMWF HAS BACKED OFF FROM THAT
SOLUTION AND IS SIMILAR TO THE GFS IN SHOWING A WEAK TROUGH OVER
THE SE GULF AND STRAITS OF FLORIDA. THE NORTHWEST FLOW ALOFT WILL
INTRODUCE SLIGHTLY DRIER AIR WHICH WOULD BRING POPS BACK DOWN TO
THE 30/40 PERCENT RANGE FOR THE LATTER PART OF THE WEEK INTO NEXT
WEEKEND. NOT A DRY FORECAST, BUT PROBABLY NOT AS WET AS THE FIRST
PART OF THE WEEK.
TEMPERATURES THROUGH THE FORECAST PERIOD WILL SHOW LITTLE CHANGE
AS CONTINENTAL AIR REMAINS WELL TO OUR NORTH.
MARINE...
BAND OF STRONG CONVECTION MOVING WEST THROUGH GULF WATERS IS
PROMPTING SPECIAL MARINE WARNINGS FOR WIND GUSTS IN EXCESS OF 40
KTS. THIS FEATURE SHOULD EXIT BY EARLY THIS EVENING...THEN
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED
FOR ALL THE WATERS THROUGH AT LEAST MID-WEEK.
AWAY FROM SHOWERS AND THUNDERSTORMS...EAST WINDS OF 10-15 KTS WILL
PREVAIL WITH SEAS LESS THAN 3 FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 89 78 88 / 50 50 40 60
FORT LAUDERDALE 79 88 80 89 / 50 60 40 60
MIAMI 78 89 79 89 / 50 60 40 60
NAPLES 75 93 75 91 / 40 70 40 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS MIAMI FL
236 PM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED NORTH OF THE REGION WILL ESTABLISH MODEST
BUT DEEP EASTERLY FLOW OVER SOUTH FLORIDA FOR MUCH OF NEXT WEEK.
THIS WILL ADVECT TROPICAL MOISTURE INTO THE AREA...RESULTING IN
INCREASING CHANCES OF SHOWERS AND THUNDERSTORMS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
SAL APPEARS TO BE SUCCESSFULLY SUPPRESSING CONVECTION TODAY OVER
MOST OF SOUTH FLORIDA. EASTERLY FLOW IS A BIT STRONGER TODAY THAN
YESTERDAY...SO GULF BREEZE HAS BEEN SLOW TO DEVELOP...WHILE
ATLANTIC BREEZE IS NOW INLAND OF METRO EAST COAST METRO AREAS.
ISOLATED TO SCATTERED CONVECTION IS STILL EXPECTED ALONG AND AHEAD
OF EITHER SEA-BREEZE...WITH GREATEST COVERAGE NEAR/WEST OF LAKE
OKEECHOBEE...WHERE LOW/MID-LEVELS ARE LEAST DRY AND DUST LAYER IS
LESS SIGNIFICANT. 18Z VSB SATELLITE ALREADY DEPICTS SIGNIFICANT CU
FIELD IN THIS REGION...AND HRRR FORECAST COMPOSITE REFLECTIVITY IS
MORE IMPRESSIVE THAN WAS INDICTED YESTERDAY AT THIS TIME. EXPECT
ACTIVITY TO HAVE SLOW SOUTHWARD DRIFT...THOUGH WITH LOW PWATS
FLOODING IS NOT A SIGNIFICANT THREAT. FORECAST AND 12Z SOUNDING
WERE NOT PARTICULARLY FAVORABLE FOR ANYTHING STRONGER THAN TYPICAL
SUMMERTIME CONVECTION...SO WILL LEAVE HWO MENTIONING FREQUENT
CLOUD-TO-GROUND LIGHTNING AS MAIN THREAT. CONVECTION WILL
DIURNALLY WANE.
UPPER-LEVEL TROUGH OVER EASTERN CONUS LIFTS NORTHWARD
TONIGHT...ALLOWING DEEP LAYER HIGH PRESSURE TO BUILD OVER THE
SOUTHEAST UNITED STATES AND ADJACENT ATLANTIC. WITH THE RIDGE AXIS
NORTH OF SOUTH FLORIDA...DEEP EASTERLY FLOW WILL
ESTABLISH...USHERING IN GREATER MOISTURE AND CAUSING AN UPWARD-
TREND IN POPS SUNDAY INTO MONDAY. SCATTERED TO PERHAPS NUMEROUS
CONVECTION IS EXPECTED BOTH AFTERNOONS. TEMPERATURES WILL BE
SOMEWHAT REGULATED BY THE INCREASE IN PCPN/CLOUDS...BUT OVERALL
WILL REMAIN NEAR NORMAL FOR MID-SEPTEMBER.
.LONG TERM /TUESDAY THROUGH FRIDAY...
SIMILAR SYNOPTIC CONDITIONS WILL PERSIST THROUGH MUCH OF THE
PERIOD WITH MODELS PROJECTING LIKELY POPS. FOR NOW...CAPPING RAIN
CHANCES AT THIS TIME IN THE 40-50% RANGE. IN THE LATTER HALF OF
THE WEEK LOW LEVEL RIDGE PERSISTS AND WITH MOISTURE LEVELS
REMAINING CLOSE TO NORMAL RAIN CHANCES ARE FORECAST TO BE NEAR
CLIMO WITH DIURNALLY DRIVEN SHOWERS AND THUNDERSTORMS FORECAST
WEDNESDAY THROUGH FRIDAY. AS IN THE SHORT RANGE...TEMPERATURE
PATTERN OF NEARLY NORMAL DAYTIME HIGHS AND ABOVE NORMAL OVERNIGHT
LOWS WILL PERSIST.
&&
.AVIATION...
THE EAST AND WEST COAST SEA-BREEZES HAVE FORMED. FOR THE EAST COAST
TERMINALS SHOWERS/THUNDERSTORMS WILL LIKELY REMAIN WESTWARD OF THE
TERMINALS WITH VCSH ASSIGNED ALTHOUGH ACTIVE CONVECTION IS NOT
EXPECTED TODAY. FOR TERMINAL KAPF VCTS ASSIGNED AT 19Z...ALTHOUGH
THUNDERSTORMS COULD BE INLAND AND EAST OF THE TERMINAL WHICH IS
INDICATED IN LATEST MESO-SCALE MODEL GUIDANCE. BUT GIVEN THE
UNCERTAINTIES VCTS ASSIGNED. MAINLY VFR CONDITIONS EXPECTED THIS
AFTERNOON ALL TERMINALS...BUT ANY OCCURRENCE OF SHOWERS OR A
THUNDERSTORM COULD RESULT IN BRIEF SUB-VFR CONDITIONS.
&&
.MARINE...
EAST WINDS OF 5-15 KTS WILL PREVAIL FOR MOST OF THE NEXT 5 DAYS.
SEAS WILL BE 3 FEET OR LESS. SCATTERED THUNDERSTORMS SHOULD BE
PRESENT OVER THE WATERS BEGINNING SUNDAY AFTERNOON AND CONTINUE
THROUGH AT LEAST MID-WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 89 78 89 / 10 40 30 50
FORT LAUDERDALE 79 89 80 90 / 20 40 30 50
MIAMI 79 90 79 89 / 20 40 30 50
NAPLES 76 91 76 91 / 10 40 30 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...23/SK
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1019 AM EDT SAT SEP 14 2013
.DISCUSSION...
.UPDATE... VERY WEAK RIDGE AXIS LIES ACROSS SOUTH-CTRL FL THIS
MORNING...SOUTH OF THE COLD FRONT DRAPED ACROSS NORTH FL. SFC
METARS AND PROFILER DATA SHOW A DEARTH OF WIND FLOW THROUGH THE
0-2KM BLYR. MORNING RAOBS INDICATE MEAN PWAT HAS RECOVERED A BIT
OVER FRIDAY...WITH VALUES GENERALLY RUNNING IN THE 1.6" TO 1.7"
RANGE...NOT TOO FAR FROM THE MEDIAN FOR MID-SEP. WATER VAPOR
AND RUC ANLYS FIELDS SHOW THE UPPER TROUGH OVER THE SERN CONUS
DROPPING SEWD...WHILE THE MID LEVEL REFLECTION OF THE TROUGH IS
LIFTING OUT OVER THE WRN ATLC.
EARLY 12Z NAM GUIDANCE SHOWS UPPER TROUGH DROPPING SE ACROSS FL
OVER THE NEXT H24 AS THE BOUNDARY TO THE NORTH WASHES OUT WITH
MID LEVEL RIDGE GRADUALLY BUILDING INTO FL. SIMILAR TO FRI...
THIS SETUP APPEARS TO FAVOR SOMEWHAT OF A LATER START TO DIURNAL
CONVECTION (PERHAPS NOT QUITE AS LATE) WITH SLIGHTLY BETTER RAIN
CHANCES INLAND COMPARED TO THE COAST...WITH PERHAPS SOME SLIGHT
EASTWARD DRIFT TO LATE AFTN/EARLY EVENING CONVECTION. MADE SOME
SLIGHT TWEAKS TO POPS TO TRIM BACK COASTAL/MARINE POPS TO SLIGHT
CHANCE (15-20). OTHERWISE...FORECAST WILL REMAIN LARGELY INTACT.
&&
.AVIATION...MADE SOME VERY MINOR TWEAKS TO TAFS TO SHOW A LITTLE
EARLIER START TO DIURNAL CONVECTION (PREVAILING VCTS FOR A FEW HRS)
OVER THE INTERIOR 22Z-02Z). CURRENTLY DO NOT HAVE ANY VC TERM FOR
THE COASTAL AERODROMES...BUT WILL NEED TO MONITOR EARLY-MID AFTN
RADAR TRENDS FOR ANY POTENTIAL AMDS.
&&
.MARINE...VERY LIGHT FLOW INVOF RIDGE AXIS WITH SEAS 2FT OR LESS.
LOOKS AS THOUGH WAVE MODEL GUIDANCE IS RUNNING ABOUT A FOOT TOO
HIGH OVER THE NEXT FEW PERIODS. PLAN TO SHAVE BACK ACCORDINGLY.
&&
FORECAST UPDATES...CRISTALDI
IMPACT WX/RADAR...BRAGAW
&&
.PREV DISCUSSION... /ISSUED 325 AM EDT SAT SEP 14 2013/
SUNDAY...MID LVL TROUGH OFF THE SE ATLC COAST WILL BEING TO SLOWLY
NE WITH SFC HIGH PRESSURE OFF THE MID ATLC AND ESE LOW LVL FLOW.
MOISTURE LEVELS WILL BE HIGHEST ACROSS SRN SECTIONS WHERE SCATTERED
SHOWERS AND ISOLATED LIGHTNINGS STORMS WILL MOVE INLAND TOWARD
AFTERNOON. DRIER AIR LINGERING ACROSS FAR NRN SECTIONS AND ONSHORE
FLOW WILL LIMIT RAIN CHANCES ACROSS N CSTL SECTIONS WHERE WILL
ADVERTISE 20 PCT. HIGHS UPPER 80S COAST TO LWR 90S INTERIOR.
SUNDAY NIGHT...MOIST ONSHORE LOW LVL FLOW WILL KEEP THE CHANCE FOR
AN ONSHORE MOVING SHOWER OR TSTM ALONG COASTAL AREAS THROUGH THE
NIGHT. WILL LIMIT SHOWER/TSTM CHCS FOR THE INTERIOR IN THE EVENING.
MONDAY...SFC RIDGE AXIS WILL REMAIN OFF THE SC COAST WITH ONSHORE
ESE LOW LVL FLOW. MOISTURE LVLS WILL AGAIN BE HIGHEST ACROSS SRN
SECTIONS WHERE 40 PCT SHOWER/TSTM CHCS ARE EXPECTED WITH 30 PCT
ACROSS MUCH OF THE REMAINDER OF THE FORECAST AREA. WILL AGAIN GO
WITH LOWER POPS ALONG THE VOLUSIA COAST WHERE EAST COAST SEA BREEZE
MOVING INLAND AND SLIGHTLY LOWER MOISTURE LVLS ARE EXPECTED.
TUE-THU...MID WEEK FORECAST LOOKS A BIT WETTER PER LATEST 00Z
GFS/ECMWF RUNS WITH DEEP MOISTURE RETURNING AND CONTINUED INCREASING
ONSHORE LOW LVL FLOW. APPEARS SOME CONNECTION TO THE DEEPER TROPICAL
MOISTURE ACROSS THE SE GULF AND FL STRAITS MAY TRY TO MAKE SOME
INROADS NWD TWD E CENTRAL FL...ESPEC BY WED. WILL BRING POPS INTO
THE MID SCATTERED RANGE 40-50 PCT FOR MID WEEK WITH ONSHORE MOVING
SHOWERS AND SOME STORMS...POSSIBLY BRINGING SOME LOCALLY HEAVY RAIN
ALONG THE EAST COAST IN SPOTS. HAVE INCREASED CLOUD COVER FOR MID
WEEK WITH CONSIDERABLE CLOUDINESS AT TIMES. HIGHS UPPER 80S COAST TO
AROUND 90 INTERIOR.
FRI-SAT...GFS/ECMWF ARE DIFFERING ON THE EVOLUTION AND SPEED OF NEXT
MID LVL WAVE NEAR FLORIDA WITH GENERAL TRENDS PUTTING E CENTRAL FL
ON THE BACK SIDE OF THE MID-UPR LVL TROUGH AND SOME DRYING COMPARED
TO MID WEEK. WILL KEEP POPS MAINLY IN THE 30 PCT RANGE TO START NEXT
WEEKEND...CLOSE TO GFS MOS.
&&
.AVIATION...VFR WITH PATCHES OF SHALLOW GROUND FOG...MIFG...AROUND
SUNRISE SATURDAY. SOME SITES WENT BRIEFLY IFR AROUND SUNRISE FRIDAY
THEN QUICKLY BECAME VFR AS THE SUN CLIMBED HIGHER IN THE SKY BURNING
OFF THE LOW CLOUDS. TEMPO MVFR MAINLY INTERIOR SITES 20Z-02Z IN THE
VICINITY OF STORMS. VFR AFTER 15/04Z WITH SHALLOW GROUND FOG AROUND
SUNRISE MONDAY.
&&
.MARINE...
CURRENT...BUOYS RECORDING SOUTH WINDS AROUND 10 KNOTS AND 2 FOOT
SEAS WITH AN 8 SECOND PERIOD.
SAT...WEST TO SOUTHWEST WIND 5 TO 10 KNOTS BECOMES EASTERLY 10 KNOTS
AT THE COAST SATURDAY AFTERNOON DUE TO THE SEA BREEZE COMPONENT.
SEAS 2 FEET NEARSHORE AND 2 TO 3 FEET OFFSHORE.
SAT NIGHT...WINDS 10 KNOTS BECOME EAST OVERNIGHT AS A SURFACE RIDGE
MOVES NORTHWARD OVER THE CENTRAL FLORIDA WATERS.
SUN-WED...EASTERLY WINDS WILL INCREASE INTO MID WEEK TO 10-15 KNOTS
WITH SEAS 2-4 FT (MAINLY IN AN EAST SWELL) ON SUNDAY GRADUALLY
INCREASING TO 4-5 FT OFFSHORE BY WED. SHOULD ALSO SEE AN INCREASING
COVERAGE OF ONSHORE MOVING MARINE SHOWERS/TSTMS BY TUE/WED OF NEXT
WEEK. EXPECT AN ELEVATED RIP CURRENT RISK DEVELOPING NEXT WEEK WITH
ONSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 90 75 90 76 / 30 20 20 20
MCO 93 74 92 74 / 40 20 30 20
MLB 89 76 89 78 / 30 20 30 30
VRB 89 76 90 77 / 30 20 30 30
LEE 93 74 92 75 / 30 20 30 20
SFB 93 75 92 76 / 30 20 20 20
ORL 93 76 92 76 / 40 20 30 20
FPR 89 75 89 77 / 30 20 40 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
704 PM CDT SUN SEP 15 2013
.SYNOPSIS...
ISSUED AT 250 PM CDT SUN SEP 15 2013
A COLD FRONT STRETCHING FROM NORTHEAST TO CENTRAL AND
SOUTHWEST KANSAS IS KEEPING ON ITS SOUTHEAST TRACK. THIS FRONT WILL
PUSH THROUGH THIS EVENING...AND A RIDGE WILL BE ON ITS TAILS FOR
MONDAY. A FAIRLY ACTIVE PATTERN IS IN PLACE TO KEEP SYSTEMS MOVING
ACROSS THE CONUS.
&&
.UPDATE...
ISSUED AT 701 PM CDT SUN SEP 15 2013
PUT OUT A QUICK UPDATE TO TWEAK STORM CHANCES OVER THE NEXT FEW HOURS.
CURRENT THINKING IS THAT THE STORMS SHOULD STAY CONFINED TO
SOUTHERN KS FOR THE NEXT FEW HOURS. THERE SHOULD BE A GRADUAL
INCREASE IN COVERAGE TOWARD 06Z AS ISENTROPIC LIFT NORTH OF THE
FRONT INCREASES WITH SOME OF THIS ACTIVITY TRYING TO SPREAD BACK
INTO CENTRAL KS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 250 PM CDT SUN SEP 15 2013
AS MENTIONED IN THE SYNOPSIS...THE COLD FRONT SHOULD CONTINUE TO
SLIDE THROUGH THE REST OF KANSAS AND INTO OKLAHOMA THIS EVENING
AND TONIGHT. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO
BUBBLE UP ALONG AND BEHIND THIS FRONTAL FEATURE THIS AFTERNOON
GIVEN DAYTIME HEATING AND . SOME OF THE STORMS COULD BE STRONG
WITH ABOVE 1K J/KG CAPE VALUES MAINLY IN SOUTH CENTRAL
KANSAS...HOWEVER 0-6KM BULK SHEAR VALUES ARE LESS THAN 30KTS
ACCORDING TO THE MODELS DURING THIS RESPECTIVE TIME FRAME FOR ALL
BUT THE RUC WHICH HAS VALUES JUST AT 40KTS. PRECIPITATION ACTIVITY
IS STILL ANTICIPATED TO LINGER INTO MUCH OF MONDAY AND TUESDAY
WHEN ANOTHER SHORTWAVE IN THE MID LEVELS MOVES THROUGH THE AREA.
ANOTHER TROUGH AT 500MB AND 700MB IS GOING TO MOVE ONSHORE ON
TUESDAY...WHILE THE 850MB TROUGH HALTS AND STARTS TO DEVELOP ALONG
THE FRONT RANGE. EVENING POPS ON TUESDAY WERE SLIGHTLY DROPPED
FROM THE PREVIOUS FORECAST...BUT THE MAIN TRENDS FOR ALL OTHER
PARAMETERS WERE MAINTAINED. COOLER AIR ON MONDAY AND CLOUD COVER
WILL KEEP HIGHS BELOW SEASONAL NORMAL BY 5 DEGREES IN SOUTH
CENTRAL KANSAS AND AS MUCH AS 10 DEGREES IN CENTRAL KANSAS.
TUESDAY SHOULD REBOUND BACK TO ABOVE NORMAL IN THE MID TO UPPER
80S.
JUANITA
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN SEP 15 2013
WEDNESDAY THRU THURSDAY: IN THIS TIME FRAME...THE NEXT SYSTEM IS
EXPECTED TO MOVE THROUGH THE PLAINS. WHILE THE CENTER OF THE LOW
STAYS ACROSS THE CANADIAN AND U.S. BORDER AND MOVES THE FRONT ON
WEDNESDAY INTO THURSDAY...THERE ARE MODEL DIFFERENCES IN ITS TIMING.
ECMWF IS MORE PROGRESSIVE WITH PUSHING THE FRONT THROUGH THE AREA.
THERE COULD BE A CHANGE IN PRECIP ACTIVITY WITH THIS DIFFERENCE.
POPS WERE SLIGHTLY INCREASED FOR THURSDAY AND THURSDAY EVENING WITH
A SMIDGEN OF BETTER CONSISTENCY.
FRIDAY THRU SUNDAY: CURRENT MODEL PREDICTIONS OF THIS TIME FRAME MAKE IT
APPEAR THAT A RIDGE WILL BE IN PLACE. MODEL DISCREPANCIES BEGIN AT
THE START OF NEXT WEEK WHICH MAY MAKE AN IMPACT TO THE FORECAST
FOR SUNDAY DEPENDING ON THE POTENTIAL PROGRESSIVE NATURE OF THE
SYSTEM. THIS IS TOO FAR OUT FOR ANY CERTAINTY IN EITHER PREDICTION
OF THE NEXT SYSTEM TO MOVE THROUGH THE CENTRAL UNITED STATES.
SLIGHT CHANCES WERE PUT IN FOR SUNDAY...BUT AGAIN CONFIDENCE IS
LOW AT THIS TIME.
JUANITA
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 636 PM CDT SUN SEP 15 2013
AVIATION CONCERNS WILL BE CONVECTIVE CHANCES OVER SOUTHERN KS AND
LOWER CEILINGS MOVING SOUTH.
COLD FRONT CURRENTLY EXTENDS FROM NEAR KICT TO NEAR KEMP AND IS
CONTINUING TO SURGE SOUTH. STORMS DEVELOPED ALONG THIS FRONT A FEW
HOURS AGO OVER CENTRAL KS AND KICKED OUT AN OUTFLOW BOUNDARY THAT
LOOKS TO HAVE ESSENTIALLY BECOME THE FRONT. SCT STORMS ARE
EXPECTED TO CONTINUE OVERNIGHT INTO MON MORNING FOR SOUTHERN KS
WITH KICT AND KCNU HAVING THE BEST CHANCES TO EXPERIENCE THE
STORMS. FURTHER NORTH...MVFR CIGS WILL CONTINUE TO SLOWLY MOVE
SOUTH...MAKING IT TO KICT BEFORE SUNRISE. CONFIDENCE IS FAIRLY HIGH AT
THIS POINT THAT THE CIGS SHOULD STAY ABOVE IFR LEVELS.
LAWSON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 65 78 65 86 / 50 50 30 30
HUTCHINSON 62 75 63 85 / 50 50 30 30
NEWTON 61 74 62 83 / 50 50 30 30
ELDORADO 63 78 63 84 / 50 50 30 30
WINFIELD-KWLD 67 81 65 86 / 60 60 30 30
RUSSELL 58 72 61 86 / 40 40 40 30
GREAT BEND 59 73 62 85 / 40 40 40 30
SALINA 60 73 62 84 / 40 40 40 40
MCPHERSON 61 74 63 84 / 40 40 30 40
COFFEYVILLE 66 83 65 86 / 60 60 40 40
CHANUTE 64 78 63 85 / 60 60 40 40
IOLA 63 76 62 84 / 60 50 40 40
PARSONS-KPPF 65 81 64 85 / 60 60 40 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
642 PM CDT SUN SEP 15 2013
.SYNOPSIS...
ISSUED AT 250 PM CDT SUN SEP 15 2013
A COLD FRONT STRETCHING FROM NORTHEAST TO CENTRAL AND
SOUTHWEST KANSAS IS KEEPING ON ITS SOUTHEAST TRACK. THIS FRONT WILL
PUSH THROUGH THIS EVENING...AND A RIDGE WILL BE ON ITS TAILS FOR
MONDAY. A FAIRLY ACTIVE PATTERN IS IN PLACE TO KEEP SYSTEMS MOVING
ACROSS THE CONUS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 250 PM CDT SUN SEP 15 2013
AS MENTIONED IN THE SYNOPSIS...THE COLD FRONT SHOULD CONTINUE TO
SLIDE THROUGH THE REST OF KANSAS AND INTO OKLAHOMA THIS EVENING
AND TONIGHT. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO
BUBBLE UP ALONG AND BEHIND THIS FRONTAL FEATURE THIS AFTERNOON
GIVEN DAYTIME HEATING AND . SOME OF THE STORMS COULD BE STRONG
WITH ABOVE 1K J/KG CAPE VALUES MAINLY IN SOUTH CENTRAL
KANSAS...HOWEVER 0-6KM BULK SHEAR VALUES ARE LESS THAN 30KTS
ACCORDING TO THE MODELS DURING THIS RESPECTIVE TIME FRAME FOR ALL
BUT THE RUC WHICH HAS VALUES JUST AT 40KTS. PRECIPITATION ACTIVITY
IS STILL ANTICIPATED TO LINGER INTO MUCH OF MONDAY AND TUESDAY
WHEN ANOTHER SHORTWAVE IN THE MID LEVELS MOVES THROUGH THE AREA.
ANOTHER TROUGH AT 500MB AND 700MB IS GOING TO MOVE ONSHORE ON
TUESDAY...WHILE THE 850MB TROUGH HALTS AND STARTS TO DEVELOP ALONG
THE FRONT RANGE. EVENING POPS ON TUESDAY WERE SLIGHTLY DROPPED
FROM THE PREVIOUS FORECAST...BUT THE MAIN TRENDS FOR ALL OTHER
PARAMETERS WERE MAINTAINED. COOLER AIR ON MONDAY AND CLOUD COVER
WILL KEEP HIGHS BELOW SEASONAL NORMAL BY 5 DEGREES IN SOUTH
CENTRAL KANSAS AND AS MUCH AS 10 DEGREES IN CENTRAL KANSAS.
TUESDAY SHOULD REBOUND BACK TO ABOVE NORMAL IN THE MID TO UPPER
80S.
JUANITA
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN SEP 15 2013
WEDNESDAY THRU THURSDAY: IN THIS TIME FRAME...THE NEXT SYSTEM IS
EXPECTED TO MOVE THROUGH THE PLAINS. WHILE THE CENTER OF THE LOW
STAYS ACROSS THE CANADIAN AND U.S. BORDER AND MOVES THE FRONT ON
WEDNESDAY INTO THURSDAY...THERE ARE MODEL DIFFERENCES IN ITS TIMING.
ECMWF IS MORE PROGRESSIVE WITH PUSHING THE FRONT THROUGH THE AREA.
THERE COULD BE A CHANGE IN PRECIP ACTIVITY WITH THIS DIFFERENCE.
POPS WERE SLIGHTLY INCREASED FOR THURSDAY AND THURSDAY EVENING WITH
A SMIDGEN OF BETTER CONSISTENCY.
FRIDAY THRU SUNDAY: CURRENT MODEL PREDICTIONS OF THIS TIME FRAME MAKE IT
APPEAR THAT A RIDGE WILL BE IN PLACE. MODEL DISCREPANCIES BEGIN AT
THE START OF NEXT WEEK WHICH MAY MAKE AN IMPACT TO THE FORECAST
FOR SUNDAY DEPENDING ON THE POTENTIAL PROGRESSIVE NATURE OF THE
SYSTEM. THIS IS TOO FAR OUT FOR ANY CERTAINTY IN EITHER PREDICTION
OF THE NEXT SYSTEM TO MOVE THROUGH THE CENTRAL UNITED STATES.
SLIGHT CHANCES WERE PUT IN FOR SUNDAY...BUT AGAIN CONFIDENCE IS
LOW AT THIS TIME.
JUANITA
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 636 PM CDT SUN SEP 15 2013
AVIATION CONCERNS WILL BE CONVECTIVE CHANCES OVER SOUTHERN KS AND
LOWER CEILINGS MOVING SOUTH.
COLD FRONT CURRENTLY EXTENDS FROM NEAR KICT TO NEAR KEMP AND IS
CONTINUING TO SURGE SOUTH. STORMS DEVELOPED ALONG THIS FRONT A FEW
HOURS AGO OVER CENTRAL KS AND KICKED OUT AN OUTFLOW BOUNDARY THAT
LOOKS TO HAVE ESSENTIALLY BECOME THE FRONT. SCT STORMS ARE
EXPECTED TO CONTINUE OVERNIGHT INTO MON MORNING FOR SOUTHERN KS
WITH KICT AND KCNU HAVING THE BEST CHANCES TO EXPERIENCE THE
STORMS. FURTHER NORTH...MVFR CIGS WILL CONTINUE TO SLOWLY MOVE
SOUTH...MAKING IT TO KICT BEFORE SUNRISE. CONFIDENCE IS FAIRLY HIGH AT
THIS POINT THAT THE CIGS SHOULD STAY ABOVE IFR LEVELS.
LAWSON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 65 78 65 86 / 60 50 30 30
HUTCHINSON 62 75 63 85 / 60 50 30 30
NEWTON 61 74 62 83 / 70 50 30 30
ELDORADO 63 78 63 84 / 60 50 30 30
WINFIELD-KWLD 67 81 65 86 / 60 60 30 30
RUSSELL 58 72 61 86 / 40 40 40 30
GREAT BEND 59 73 62 85 / 40 40 40 30
SALINA 60 73 62 84 / 40 40 40 40
MCPHERSON 61 74 63 84 / 50 40 30 40
COFFEYVILLE 66 83 65 86 / 70 60 40 40
CHANUTE 64 78 63 85 / 70 60 40 40
IOLA 63 76 62 84 / 70 50 40 40
PARSONS-KPPF 65 81 64 85 / 70 60 40 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
846 PM EDT SUN SEP 15 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT FOLLOWED BY HIGH
PRESSURE THROUGH MID WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPPER AIR ANALYSIS SHOWS WELL DEFINED SHORTWAVE TROUGH CROSSING
THE GREAT LAKES REGION. AT THE SURFACE...COLD FRONT IS PROGGED TO
MOVE OVER THE REGION LATE TONIGHT. CURRENT UPPER AIR SOUNDING
DISPLAYS DRY AIR AT LOW LEVELS. HENCE...ANY RADAR ECHOS BEING
DISPLAYED IN OR NEAR THE CWA IS VIRGA AND IS FURTHER EVIDENT BY
CURRENT SURFACE OBSERVATIONS. RAP MODEL SOUNDINGS ARE ON POINT
WITH THE DRY AIR LINGERING AT LOWER LEVELS AND SUGGESTING COMPLETE
SATURATION A FEW HOURS AFTER MIDNIGHT. POPS REFLECT WHAT THE
MODELS SUGGEST AND HAVE INCREASED POPS TO HIGH CHANCE OVERNIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
AS THE FRONT PUSHES THROUGH THE SOUTHERN HALF OF THE AREA ON
MONDAY...THE BEST CHANCES OF SHOWERS WILL ALSO TRANSLATE SOUTHWARD
WITH IT. A SECONDARY SHORT WAVE TROUGH LOOKS TO QUICKLY FOLLOW
BEHIND IT...ALSO BRINGING A BIT MORE COLD ADVECTION ALOFT. THIS
SHOULD INCREASE LAPSE RATES IN THE LOW LEVELS AND ALSO ALIGN THE
FLOW FROM A NORTHWESTERLY DIRECTION WHILE RAISING INVERSION LEVELS
TOWARD 9 KFT OFF LAKE ERIE. LAKE TO 850 MB DELTA T VALUES LOOK TO
RUN IN THE RANGE OF 14C...WHICH SHOULD BE ENOUGH COMBINED WITH A
MID-LEVEL COLD POOL TO GENERATE A FEW SHOWERS DOWN FROM THE LAKE.
THESE WILL CARRY IN AN ISOLATED FASHION INTO THE NORTHERN PORTIONS
OF THE FORECAST AREA MONDAY AFTERNOON...WITH JUST A FEW SPRINKLES
FARTHER DOWNSTREAM.
COLD NIGHTS SEEM LIKELY TO FOLLOW THE SYSTEM FROM MONDAY ON MONDAY
NIGHT AND TUESDAY NIGHT. CLOUDS WILL LIKELY BE THE MITIGATING
FACTOR ON MONDAY NIGHT AS LOW LEVEL MOISTURE WILL AGAIN NEED TO BE
SCOURED OUT TO ALLOW FOR DISSIPATION OF THE STRATOCUMULUS LAYER
THAT WILL LIKELY BE GENERATED DOWNWIND OF LAKE ERIE. AS SUCH...IT
IS DEBATABLE WHETHER MONDAY OR TUESDAY NIGHT WILL BE COLDER AT THE
MOMENT. REGARDLESS...BOTH NIGHTS WILL BE RATHER COLD...ALL THE
WHILE HIGH TEMPERATURES TREND BACK TOWARD NORMAL TOWARD MID-WEEK
WITH SURFACE HIGH PRESSURE BUILDING QUICKLY INTO THE REGION. FRIES
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LONG RANGE MODELS AGREE ON UPPER LEVEL RIDGE OVER THE REGION
THROUGH THURSDAY NIGHT BUT ECMWF AND GFS CONTINUE TO HAVE
DIFFERENCES WITH THE LOCATION OF THE MID LVL WAVE TRAVERSING BY FRIDAY.
GFS DESPITE HAVING A MORE AMPLIFIED H5 RIDGE...DEPICTS QPF AND
POCKET OF ENERGY FARTHER SOUTH OVER THE TN RVR VALLEY...WHILE
ECMWF OUTPUTS QPF ACROSS THE OHIO VALLEY. LEANED MORE TOWARD THE
LATTER GIVEN POSITION OF S/W TROUGH WITH RESPECT TO H5 HEIGHT
PATTERN.
AREA FULLY IN WARM SECTOR FRIDAY INTO THE WEEKEND BEFORE COLD FRONT
CROSSES SAT NGT INTO SUN. MSTR PUMPED N FROM THE GULF WILL CREATE
MILD NIGHTS FRI AND SAT WHILE DAYTIME HIGHS WILL BE 5 - 10F ABOVE
NORMAL. IF BOUNDARY SLOWS DOWN WHICH IS A GOOD POSSIBILITY...80
DEGREE WEATHER COULD RETURN BY WEEKS END FOR A DAY OR TWO.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHING WESTERN LAKE ERIE WILL SAG SOUTH ACROSS
THE AREA TONIGHT. LIGHT SOUTH WIND WILL BECOME N TO NE BEHIND THE
FRONT TOWARD DAYBREAK. CIGS EXPECTED TO DIP TO MVFR TOWARD EARLY
MORNING BEHIND THE FRONT WITH A FEW MVFR SHOWERS AS WELL. MVFR AND
ISOLATED IFR FOG DEVELOPMENT WILL ALSO BE POSSIBLE IN THE PREDAWN
HOURS. AS FRONT PUSHES SOUTH MONDAY DRY HIGH PRESSURE WILL GIVE VFR
CLOUD COVER ACROSS THE AREA WITH COLD ADVECTION.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
VFR THROUGH WEDNESDAY. A WARM FRONT MOVING NORTH THURSDAY
FOLLOWED BY A COLD FRONT FRIDAY WILL BRING POSSIBLE RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
914 AM MDT SAT SEP 14 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
UPDATED FORECAST TO ACCOUNT FOR PPT TRENDS CURRENTLY ON RADAR AND
EXTRAPOLATED IN THE HRRR AND NAM MODELS.
FRONT CURRENTLY RUNS NORTHEAST TO SOUTHWEST ACROSS THE AREA AND A
FEW SHOWERS HAVE POPPED UP ALONG IT IN ROOSEVELT...MCCONE...AND
GARFIELD COUNTY WITH SOME LIGHTER SHOWERS TO THE SOUTH. WITH
NORTHERLY FLOW BEHIND THE FRONT...THIS ACTIVITY WILL MOVE
SOUTHWARD AND LEAVE THE AREA BY 6PM TODAY.
850MB WINDS WERE WEAKER IN THIS MORNING`S SOUNDING THAN FORECAST
IN THE MODELS...HOWEVER...THIS IS MOSTLY A RESULT OF FRONTAL
TIMING...WHICH IS SLIGHTLY SLOWER THAN THE MODELS HAVE. MID-
LEVEL WINDS ARE STILL FORECAST TO INCREASE THROUGH THE LATE
MORNING AND AFTERNOON AS THE FRONT PROGRESSES...AND STILL EXPECT
LAKE WIND ADVISORY TO VERIFY. SURFACE WINDS SUNDAY AND MONDAY
MAYBE A LITTLE WEAKER THAN TODAY...AND NEXT FORECAST PACKAGE WILL
NEED TO DECIDE IF AN ADVISORY FOR WIND IS NEEDED FOR THE LAKE FOR
THOSE DAYS. MARTIN
PREVIOUS DISCUSSION...
A SURFACE LOW PRESSURE SYSTEM OVER THE SOUTHEASTERN SECTION OF THE
STATE WILL PUSH OFF INTO THE NORTHERN PLAINS THIS MORNING.
THEREFORE WILL KEEP SOME SHOWER/THUNDERSHOWER WORDING FOR THE
SOUTHERN AREAS FOR TODAY.
HIGH PRESSURE WILL SINK DOWN OVER THE DAKOTA/S TONIGHT KEEPING
NORTHEAST MONTANA MAINLY CLEAR...HOWEVER NOT AS COLD WITH RISING
HEIGHTS AND TEMPERATURES ALOFT. STILL ON THE DRY SIDE.
FOR THE REMAINDER OF THE WEEKEND...SLIGHTLY ABOVE NORMAL
TEMPERATURES AND CLEAR SKIES SHOULD DOMINATE.
NOW FOR THE FORECAST ISSUE FOR THE NEXT COUPLE OF DAYS... A LAKE
WIND ADVISORY FOR FORT PECK LAKE. A COOLER AIR-MASS TO THE
NORTHEAST WILL PUSH A FRONT THROUGH NORTHEAST MONTANA TODAY KICKING
UP WINDS WITH THE COLD AIR ADVECTION AND MIXING DOWN OF GUSTY
WINDS FROM ALOFT. THIS EVENING THE WINDS WILL DECOUPLE AND THE
INVERSION WILL SET UP AROUND 3000FT WHICH WILL BE ENOUGH TO LOWER
THE WIND SPEEDS BELOW ADVISORY CRITERIA.
WIND ON SUNDAY WILL BE TRICKY TO FORECAST...ALOFT THERE WILL BE
WARM AIR ADVECTION AND GENERALLY LIGHT WIND WITH LITTLE POTENTIAL
TO MIX DOWN. HOWEVER THE SURFACE PRESSURE GRADIENT WILL BUILD
WITH THE LEE TROUGH STRENGTHENING TO THE WEST AND SURFACE HIGH
PRESSURE TO THE EAST-SOUTHEAST. THE SURFACE PRESSURE GRADIENTS WILL
TIGHTEN...WILL NOT BE AS GUSTY AS TODAY...BUT THE SUSTAINED WINDS
WILL BE NEAR THE THRESHOLD OF THE LAKE WIND ADVISORY CRITERIA. FOR
NOW WILL HOLD OFF ON THE ISSUANCE OF A SECOND LAKE WIND ADVISORY
UNTIL TODAY/S EVENT IS OVER. DO FEEL THE SOUTHEAST WIND WITH THE
FULL FETCH OF THE MAIN BODY OF WATER ON FORT PECK LAKE WILL CREATE
ROUGH WATERS FOR THE FACE OF THE DAM AND THE NORTHWEST SHORELINE
BAYS AND COASTLINE. PROTON
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
THE EXTENDED FORECAST PERIOD IS DOMINATED BY A LARGE-SCALE UPPER
LEVEL-TROUGH PATTERN FROM THE PACIFIC OCEAN THROUGH THE PACIFIC
NORTHWEST STATES AND THROUGH THROUGH THE NORTHERN PLAINS STATES.
SHORT-WAVE TROUGH AND SHORT-WAVE RIDGES EMBEDDED WITHIN THE
OVERALL FLOW REGIME WILL DICTATE THE DAY-TO-DAY SENSIBLE WEATHER
EXPERIENCED OVER NORTHEAST MONTANA.
TIMING AND INTENSITY DISCREPANCIES STILL ABOUND...SO CONFIDENCE IS
NOT EXTREMELY HIGH...BUT MODEL CONSENSUS IS BEGINNING TO SHOW THE
BEST CHANCE FOR PRECIPITATION TO BE BETWEEN TUESDAY NIGHT AND
THURSDAY MORNING WITH THE PASSAGE OF A TROUGH AXIS AND COLD FRONT.
BY DAY 6...MODELS ARE SIGNIFICANTLY OUT OF PHASE WITH EACH OTHER.
OVERALL A LOWER CONFIDENCE FORECAST...BUT A GRADUAL SLIDE INTO A
MORE AUTUMN-LIKE PATTERN. BMICKELSON
&&
.AVIATION...
SCATTERED SHOWERS WITH ISOLATED THUNDER MAY CONTINUE TO AFFECT
KGDV AND KSDY TODAY. AN OUTSIDE CHANCE ALSO EXISTS AT KOLF FOR A
QUICK PASSING SHOWER. OTHERWISE EXPECT VFR CEILINGS AND
VISIBILITIES TO PREVAIL THROUGH THE REMAINDER OF THE TAF CYCLE. A
FEW NEAR MVFR CEILINGS ARE POSSIBLE FOR A TIME AT KGDV AND KSDY
WITH THE MORE CONCENTRATED SHOWER ACTIVITY. WILL EXPECT NORTH TO
NORTHEAST WINDS AT 10 TO 20 KTS WITH SOME GUSTS TO 30 KTS. MALIAWCO
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
1210 AM MDT SAT SEP 14 2013
.UPDATE...
WE MADE A MINOR UPDATE TO THE FORECAST TO PUSH THE AREA OF LIKELY
POPS FURTHER WESTWARD ACROSS MORE OF SOUTH CENTRAL MT IN RESPONSE
TO RECENT RADAR TRENDS. IT APPEARS THAT MOISTURE WILL CONTINUE IN
THE BIG TIMBER...COLUMBUS...BILLINGS AND HYSHAM AREAS FOR MUCH OF
THE NIGHT...THOUGH FORCING SHOULD WEAKEN AND DRIFT BACK SOUTHWARD
TOWARD 12 UTC PER RECENT GUIDANCE. SCHULTZ
&&
.SHORT TERM...VALID FOR SAT AND SUN...
SLOW MOVING UPPER LOW CONTINUES TO SPIN OVER THE NORTHERN GREAT
BASIN...WITH IMPRESSIVE SUBTROPICAL MOISTURE FETCH ALONG THE HIGH
PLAINS FROM NM TO MT. LATEST H3 ANALYSIS SHOWS A 50 KT JET
LIFTING INTO CENTRAL WY. AN AREA OF SHOWERS AT NOSE OF THIS JET
MAX HAS DEVELOPED FROM NEAR CPR TO THE BIG HORNS. OTHER THAN THE
ACTIVITY IN OUR FAR SOUTH...OUR AREA REMAINS DRY AS HIGH CLOUD HAS
SUPPRESSED CONVECTION TO THIS POINT...DESPITE COOLING TEMPS ALOFT
UNDERNEATH LOW TO OUR SW.
MODELS AGREE IN THEIR DEVELOPMENT OF A WEAK MID LEVEL LOW IN OUR
EAST TONIGHT...AND THIS IS CONSISTENT WITH EXPECTED GRADUAL
EASTWARD SHIFT IN THE JET ALOFT. COMBINATION OF SYNOPTIC SCALE
FORCING WITH PWATS ON THE ORDER OF AN INCH SHOULD RESULT IN GOOD
COVERAGE OF SHOWER ACTIVITY TONIGHT. RAP HAS TRENDED A BIT FURTHER
WEST WITH THIS LOW THAN THE GFS/NAM...AND THIS SEEMS REASONABLE
GIVEN CURRENT JET POSITION...SO HAVE COVERED EVERYWHERE FROM
BILLINGS EAST WITH A LIKELY POP TONIGHT. BEARTOOTH FOOTHILLS
SHOULD ALSO BE FAVORED PER DEEPENING UPSLOPE FLOW. INSTABILITY
SEEMS SUFFICIENT FOR ISOLD EMBEDDED TSTMS...BUT FOR THE MOST PART
BELIEVE WE WILL SEE LIGHT TO MODERATE SHOWERS...ESPECIALLY
CONSIDERING THE EFFECTS OF CLOUD COVER THIS AFTERNOON...SO DO NOT
SEE A SIGNIFICANT HEAVY RAIN THREAT TONIGHT.
MID LEVEL LOW WILL GET CAUGHT UP IN SAGGING CANADIAN JET AND
SHIFT EAST INTO THE DAKOTAS AROUND 12Z SATURDAY...SO EXPECT
STRONGER FORCING TO EXIT OUR AREA TOMORROW MORNING. SFC FRONTAL
PASSAGE FROM THE NORTH AND WEAK Q-VECTOR CONVERGENCE ON BACK SIDE
OF DEPARTING LOW WILL ALLOW FOR SHOWER DEVELOPMENT TOMORROW.
COOLER TEMPS ALOFT AND DIURNAL HEATING SHOULD ALLOW FOR AN
INCREASED CHANCE OF TSTMS ON SATURDAY...THOUGH BY AFTERNOON WE
WILL SEE AFFECTS OF DRIER POST FRONTAL CANADIAN AIR AS NORTH WINDS
INCREASE. THERE IS A WINDOW OF OPPORTUNITY...ALBEIT A FAIRLY
SHORT ONE...FOR DOWNPOURS AND LOCALLY HEAVY RAINFALL AMOUNTS WITH
TOMORROWS CONVECTION. HIGHEST POPS WILL BE IN OUR SOUTH AND EAST
PER UPSLOPE FLOW AND TIMING OF FROPA. EXPECT ACTIVITY TO BE
GREATLY REDUCED BY EVENING AS DRIER AND MORE STABLE SFC RIDGE
BUILDS FROM THE NORTH. HAVE SCALED BACK POPS QUITE A BIT SATURDAY
NIGHT.
AS FOR RAINFALL AMOUNTS...BELIEVE MOST AREAS WILL RECEIVE LESS
THAN AN INCH BUT CANNOT RULE OUT LOCAL AMOUNTS THAT HIGH
ESPECIALLY IN OUR SOUTH AND EAST. AS FOR BILLINGS...LOOKS LIKE ON
THE ORDER OF A QUARTER INCH WITH A HALF INCH POSSIBLE IF A HEAVY
SHOWER HITS US JUST RIGHT TOMORROW. TAKE NOTE...THIS SYSTEM IS
NOTHING LIKE WE HAD LAST WEEKEND...NOR WILL WE SEE THE INCREDIBLE
PCPN AMOUNTS THAT EASTERN COLORADO HAS EXPERIENCED OVER THE PAST
COUPLE DAYS. DIFFERENT SET UP ENTIRELY.
SUNDAY LOOKS DRY WITH INCREASED E-SE WINDS AS SFC RIDGE SHIFTS
EAST. COULD BE SOME SHOWERS/ISOLD TSTMS OVER OUR WEST/SOUTHERN
MTNS AS WEAK SHORTWAVE INTERACTS WITH MOISTURE LINGERING OVER THE
NORTHERN GREAT BASIN.
AS FOR TEMPERATURES...NEXT TWO DAYS WILL BE COOLER...BUT WITH
TEMPS NEAR TO SLIGHTLY ABOVE MID SEPTEMBER NORMALS. LOOK FOR
HIGHS MAINLY IN THE 70S SATURDAY AND SUNDAY.
JKL
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
MINIMAL CHANGES TO THE INHERITED LONG TERM FORECAST THIS
AFTERNOON...WITH MODELS IN CONTINUED GOOD AGREEMENT ON RELATIVELY
PROGRESSIVE WEATHER PATTERN. SOME TIMING DIFFERENCE REMAIN...BUT
DO NOT HAVE MUCH IMPACT ON THE OVERALL FORECAST. CHANGES CENTERED
AROUND INCREASING WINDS IN THE GAP FLOW AREAS AND WESTERN
FOOTHILLS AROUND LIVINGSTON AND BIG TIMBER... TO RESPOND TO
WEATHER SYSTEMS MOVING INTO AND OUT OF THE REGION.
STABLE CONDITIONS WILL CONTINUE INTO MONDAY...BUT CHANGE IS AGAIN
ON THE HORIZON. THE UPPER LEVEL RIDGING OVER THE AREA WILL BE
FLATTENED BY AN COLD FRONT THROUGH THE REGION MONDAY EVENING.
MONDAY WILL SEE WELL ABOVE AVERAGE TEMPERATURES AHEAD OF THE
FRONT...WITH SHOWERS AND THUNDERSTORMS DEVELOPING FROM WEST TO
EAST THROUGH THE EVENING AND NIGHT. SLIGHT CHANCE POPS WILL
CONTINUE THROUGH THE DAY TUESDAY...AS THE UPPER LEVEL TROD PASSES
EASTWARD. SO FAR MOISTURE AVAILABILITY APPEARS SOMEWHAT
LIMITED...COMPARED TO RECENT WEATHER...BUT CANNOT RULE OUT
DEVELOPMENT WITH STRENGTH OF THE SYSTEM. TEMPS WILL BE A BIT
COOLER TUESDAY...WITH EXPECTED INTERVENING CLOUD COVER AND SHOWER
ACTIVITY. THE FORECAST DRIES OUT SIGNIFICANTLY FOR THE REMAINDER
OF THE PERIOD FOLLOWING THIS WEATHER SYSTEM. TEMPS WILL FALL TO
AROUND SEASONAL AVERAGE FOR WEDNESDAY AND THURSDAY BEHIND THE
WEATHER SYSTEM...BUT JUMP BACK WELL ABOVE NORMAL FOR FRIDAY...AS
UPPER LEVEL RIDGING DEVELOPS ACROSS THE REGION. AAG
&&
.AVIATION...
RAIN/RAIN SHOWERS...AND ISOLATED THUNDERSTORMS...WILL IMPACT
CENTRAL AND WESTERN ROUTES/TERMINALS TONIGHT INTO SATURDAY
MORNING...INCLUDING KLVM...KBIL...KSHR...AND KMLS. THE RAIN AND
CLOUDS WILL PRODUCE AREAS OF MVFR...WITH LOCALIZED IFR/LIFR.
MOUNTAIN OBSCURATIONS ARE LIKELY. STC
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 062/076 052/078 055/085 057/081 054/073 049/073 049/083
65/T 20/B 01/U 23/T 32/W 11/U 00/U
LVM 054/073 047/078 050/085 049/078 045/072 042/072 041/079
54/T 22/T 22/T 23/T 32/W 21/B 02/T
HDN 058/076 050/079 051/086 054/083 052/076 048/076 050/083
66/T 21/B 11/U 13/T 32/W 11/U 00/U
MLS 061/077 050/076 053/084 058/083 056/074 050/074 052/083
66/T 10/U 01/U 12/T 33/W 11/B 00/U
4BQ 056/076 047/076 050/083 053/084 053/076 047/075 051/083
66/T 31/B 11/U 11/U 22/W 11/U 00/U
BHK 057/075 046/071 047/078 053/082 054/074 047/072 049/081
56/T 20/U 01/U 11/U 33/W 21/U 00/U
SHR 055/072 048/074 048/082 051/082 050/075 044/073 047/080
36/T 32/T 21/U 11/U 33/W 11/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1045 PM MDT Fri Sep 13 2013
UPDATED AVIATION SECTION
.DISCUSSION...
Update forthcoming. Have lowered pops across the northern portion of
the county warning area. Radar returns continue to indicate some
showers and isolated thunderstorms over southwest Montana. With
monsoonal moisture continuing to spread north, the latest RUC
analysis and HRRR data indicate showers will persist overnight over
southwest Montana. Remainder of the forecast looks good, including
temperatures. Emanuel
&&
.AVIATION...
UPDATED 0445Z.
Mid and high level moisture continues to move across the area.
Showers and isolated thunderstorms will continue overnight, mainly
south of a KHLN to KLWT line. VFR conditions persist with MVFR
conditions and gusty erratic winds possible in the vicinity of
thunderstorms.
&&
.PREV DISCUSSION...Issued 243 PM MDT Fri Sep 13 2013
Friday through Sunday...Monsoonal moisture continues to move into
the area as a mid level jet continues to move northward out of
Wyoming and into Southwest and South Central Montana. Storms have
generally been scattered and short lived...producing some lightning
along with brief heavy rainfall. Slow storm movement will create
the potential for some flash flooding...however no highlites are
anticipated at this time. Slightly cooler temperatures are
expected for Saturday across the area...with another round of
showers and storms possible...mainly over Southwest Montana.
Monday will see temperatures trend back to 5 to 10 degrees above
seasonal averages...with a decreasing chance of showers and
thunderstorms. Suk
Sunday Night through Friday...Conditions for first half of next week
looking a bit unsettled but not overly wet as large Pacific trof
with embedded shortwaves moves from the PacNW coast to ern MT by Wed
eve. Warm southwesterly flow ahead of the trof will push
temperatures into the mid-80s (about 10-12 degrees above normal) on
Mon. Then first of the shortwaves arrives Mon night, with a weak
cold front coming through the forecast area and generating scattered
showers and thunderstorms across the region. We`ll see some initial
cooling behind the front as temps on Tues cool back to the mid-70s
before a second, sharper front and colder Canadian airmass cross
east of the Divide Tues night. Forecast models are depicting broader
precipitation coverage and rainfall totals possibly reaching 0.25
inch over the central mountains before the precipitation ends Wed
morning. The more noticeable impact will the autumn-like temps, as
highs on Wed are only expected to reach the mid-/upper-60s. Breezy
west-northwest winds behind the front will make it feel a few
degrees cooler across the north-central plains. But the cool down
will be brief, as models now in better agreement than yesterday in
showing a high pressure ridge building back over the state from Wed
aftn through Fri eve, with dry conditions and gradually warming
temps. Waranauskas
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 86 53 78 50 / 10 30 20 10
CTB 86 51 76 47 / 10 10 10 10
HLN 86 54 79 51 / 30 30 30 20
BZN 84 48 78 45 / 40 40 40 30
WEY 71 38 67 35 / 60 60 40 30
DLN 78 48 75 46 / 50 50 40 30
HVR 86 54 78 46 / 10 10 10 0
LWT 83 52 74 46 / 20 40 40 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS HASTINGS NE
100 AM CDT SAT SEP 14 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 400 PM CDT FRI SEP 13 2013
ALOFT: UPR-LVL FLOW IS COMPLEX. A CUT-OFF LOW IS NEAR SLC AND WILL
REMAIN THERE THRU 00Z/SUN. A SMALL SUBTROPICAL HIGH WAS OVER TX
WITH ITS RIDGE EXTENDING N THRU THE PLAINS. A SHRTWV TROF WAS OVER
WY AND LIFTING N. THIS TROF WILL CONT INTO THE DAKOTAS TNGT-SAT
AND /COMBINED WITH A SIGNIFICANT TROF DROPPING THRU CNTRL CANADA/
WILL FORCE THE RIDGE TO DEAMPLIFY AND SHIFT E.
SFC: HIGH PRES WAS OVER THE UPR MIDWEST...WHILE A WEAK SFC LOW WAS
OVER MT...ALONG A SFC TROF. SFC WINDS WILL GRADUALLY SHIFT FROM SE
TO S TNGT AND THEN TO SW TOMORROW. THRU 00Z/SUN...THE HIGH WILL
MIGRATE TO THE MID-ATLANTIC STATES...AND THE TROF WILL SETTLE INTO
NRN AND WRN NEB...AS THE NEXT CANADIAN COOL FRONT PRESSES INTO THE
NRN PLAINS.
REST OF THIS AFTN: CLOUDY S AND W OF THE TRI-CITIES WITH THE
THREAT OF PATCHY -RA W OF HWY 183 ENDING. FROM THE TRI-CITIES N
AND E... SLOWLY INCREASING CLOUDS.
RADAR TRENDS: THE HI-RES RAP AND THE 06Z WRF-NMM HAVE DONE A VERY
NICE JOB WITH THEIR SIMULATED REFLECTIVITY TODAY AND CONTS TO
SUPPORT CURRENT TRENDS. THIS BAND OF -RA WILL CONT LIFTING N WHILE
GRADUALLY DISSIPATING AS IT PROGRESSES INTO DRIER AIR. THE FCST
AREA COULD THEN BE MOSTLY DRY THE REST OF THE NGT.
THE 12Z NAM WAS WAY TOO DRY WITH ITS 12 HR QPF ENDING AT 00Z VS
REALITY.
THE WY SHRTWV TROF WILL TAKE THE BEST FORCING FOR LIFT/PCPN INTO
THE DAKOTAS TNGT. THAT IS ALSO WHERE THE NOSE OF THE LLJ WILL BE
AIMED. CAN/T COMPLETELY RULE OUT A SHWR OR TWO WITHIN GENTLE
ISENTROPIC LIFT.
WINDS BACKED TO THE S ON THE 12Z LBF SOUNDING AND MSTR IN THE
850-500 MB LAYER INCREASED SUBSTANTIALLY. THIS IS SUPPORTING THE
ON-GOING -RA OVER WRN/SRN PARTS OF THE FCST AREA...WHICH IS AT THE
LEADING EDGE OF THE GRADIENT OF HIGHER PW. BACKING WINDS AT ALL
LVLS WILL SHOVE THE MAX PW AXIS INTO THE FCST AREA TNGT.
WHILE MUCH OF THE FCST AREA HAS SEEN THE DECENT RAINFALL IN THE
PAST 3 DAYS /MOSTLY ALONG AND S OF I-80/...THE SAD FACT IS MUCH OF
THE HIGH PW AIR MAY END UP BEING WASTED. PROSPECTS FOR RAIN ARE
NIL TNGT AND NOT LOOKING GOOD TOMORROW EXCEPT IN VERY ISOLATED
POCKETS. WHILE THE SFC TROF GETS CLOSE...AND THE TAIL END OF THE
DAKOTA/S SHRTWV TROF WILL BE OVER THE PANHANDLE ...THERE ISN/T
MUCH FORCING ALOFT. SO AM NOT EXPECTING MUCH DURING THE DAYLGT HRS
OF SAT. WE CAN HOLD OUT HOPE FOR SAT NGT.
TNGT: MAINLY CLOUDY. CAN/T ENTIRELY RULE OUT A SHWR OR TWO BUT
MOST LOCATIONS REMAIN DRY.
ONE CONCERN IS WHERE CLOUDS ARE CURRENTLY THIN FROM THE TRI-CITIES
N AND E. DWPTS ARE LOW THERE AND TEMPS WILL DROP OFF RATHER
SHARPLY THIS EVNG. FOR NOW ANTICIPATED THAT CLOUDS WILL INCREASE
IN TIME TO ARREST DROP-OFF WITH LOWS FAIRLY UNIFORM OVER THE
ENTIRE FCST AREA /MID-UPR 50S/. LOWS N AND E OF THE TRI-CITIES ARE
ONLY AVERAGE CONFIDENCE.
SAT: M/CLOUDY. TEMPS ARE LOW CONFIDENCE DUE TO CLOUD COVER
UNCERTAINTY. HIGHS WERE LOWERED 1-2F. A HIGH-PW AIR MASS WILL BE
IN PLACE /2 STANDARD DEVIATIONS ABOVE NORMAL/. EXPECT SOME AREAS
MAY THIN ENOUGH FOR MARGINAL DESTABILIZATION AND ISOLD-SCT TSTM
DEVELOPMENT...MUCH LIKE WHAT IS OCCURRING OVER SERN CO AND THE TX
PANHANDLE ATTM.
MLCAPE WILL BE LESS THAN 1000 J/KG. INDIVIDUAL CELL MVMT WILL BE
NE AROUND 25 KTS. DEEP LAYER SHEAR WILL BE 15-20 KTS. NO SVR WX IS
EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 PM CDT FRI SEP 13 2013
SATURDAY NIGHT...AN UPPER LEVEL TROUGH WITH AN ACCOMPANYING COLD
FRONT WILL SWING THROUGH THE FORECAST AREA BRINGING WITH IT OUR
BEST CHANCE OF SHOWERS AND THUNDERSTORMS. INSTABILITY WILL BE WEAK
AND THUS AM NOT EXPECTING ANY KIND OF SEVERE WEATHER...BUT RATHER
PERHAPS JUST A GENERAL LINE OR SEVERAL LINES OF SHOWERS AND
THUNDERSTORMS THAT WILL TRACK ACROSS THE AREA.
SUNDAY AND MONDAY...THE COOL FRONT WILL TRACK ACROSS KANSAS ON
SUNDAY AND WATCH OUT OVER OKLAHOMA BY SUNDAY NIGHT/MONDAY MORNING.
RAIN CHANCES WILL DECREASE ACROSS OUR FORECAST AREA WITH BETTER
CHANCES OF SHOWERS AND THUNDERSTORMS FURTHER SOUTH FOLLOWING THE
FRONT. HAVE DECREASED RAIN CHANCES ACROSS OR FORECAST AREA DURING
THIS PERIOD DUE TO THE QUICK PROGRESS OF THE FRONT AND AM NOW EVEN
GOING DRY FOR MONDAY ACROSS NEBRASKA ZONES WITH JUST A SLIGHT
CHANCE OF SHOWERS ACROSS NORTHERN KANSAS. TEMPERATURES WILL BE
COOLER BEHIND THE COLD FRONT RANGING FROM AROUND 70 NORTH TO THE
MID 70S OVER NORTHERN KANSAS.
MONDAY NIGHT/TUESDAY...A MINOR SHORTWAVE WILL TRACK NORTHEAST
ACROSS OUR FORECAST AREA AND A WEAK WARM FRONT WILL LIFT BACK
THROUGH. THIS WILL RESULT IN GENERALLY LOW END RAIN CHANCES.
TEMPERATURES WILL START TO WARM UP AND MAY ONCE AGAIN BE BACK TO
AROUND 80 BY TUESDAY AFTERNOON.
WEDNESDAY THROUGH FRIDAY...AN UPPER RIDGE WILL TRY TO BUILD ACROSS
THE PLAINS...BUT WILL NOT BE OVERLY STRONG SO NO REPEAT OF THE 90
DEGREE HEAT. EXPECT MOST AREAS WILL BE DRY WITH ABOVE NORMAL
TEMPERATURES IN THE 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1222 AM CDT SAT SEP 14 2013
CEILINGS WILL REMAIN VFR AND CHANCES OF PRECIPITATION WILL BE LOW
ENOUGH TO KEEP OUT OF THE FORECAST. WIND SPEED WILL INCREASE A BIT
BY LATE MORNING SATURDAY AS LOW-LEVEL LAPSE RATES INCREASE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1138 PM CDT FRI SEP 13 2013
.AVIATION...06Z TAFS FOR KOMA...KLNK AND KOFK. OVERALL THINKING
REMAINS THE SAME. VFR CONDITIONS WILL PREVAIL THROUGH THE
PERIOD...WITH LOWERING CLOUD HEIGHTS FROM 25000 TO 3500-7000
THROUGH TIME. WINDS WILL BE LIGHT OR FROM THE SOUTHEAST AT TAF
ISSUANCE...BUT SHOULD INCREASE TO 12 TO 15 KNOTS BY 15-17Z...AND
COULD GUST INTO THE LOWER 20S THIS AFTERNOON...WITH GUSTS
DIMINISHING ONCE AGAIN BY 00-01Z. COULD ALSO SEE A FEW SHOWERS AT
KOFK 11-15Z WHEN CEILINGS COULD LOWER TO 3000-3500 FEET.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 1039 PM CDT FRI SEP 13 2013/
DISCUSSION...
TWEAKED CLOUD COVER UP OVERNIGHT...AND TRIMMED PRECIP JUST A
LITTLE BIT IN NORTHEAST NEBRASKA. LATEST RAP DATA WOULD SUGGEST
THAT PRECIP MAY NOT MAKE IT ALL BEFORE DAYBREAK INTO NORTHEAST
NEBRASKA...AND GIVEN RADAR TRENDS...THAT MAY THE CASE. ALSO HAD
SOME CONCERN THAT TEMPS MAY NOT GET AS LOW AS PREVIOUSLY THOUGHT
IN SOME SPOTS IN EASTERN NEBRASKA GIVEN SLIGHTLY THICKER CLOUD
COVER.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 318 PM CDT FRI SEP 13 2013/
DISCUSSION...
DRIER AND COOLER AIRMASS HAS SETTLED IN ACROSS THE AREA. SUBJECTIVE
12Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL HIGH CENTERED OVER OK
BUT EXTENDING ACROSS THE CENTRAL AND SOUTHERN PLAINS...WITH UPPER-
LEVEL LOW CENTERED NEAR NORTHEAST NV/NORTHWEST UT...AND DEEPER LOW
CENTERED IN QB. WITH 850MB HIGH PLANTED FIRMLY OVER THE MID
MISSOURI RIVER VALLEY...MOISTURE WAS SHUNTED WELL SOUTH AND
WEST...WITH A COOL AND DRY POCKET CENTERED ON THE GREAT LAKES.
SURFACE HIGH AT 19Z WAS CENTERED IN THE WESTERN GREAT LAKES...WITH
TIGHTER PRESSURE GRADIENT ALONG THE HIGH PLAINS CONTRIBUTING TO
UPSLOPE FLOW ALONG THE ROCKIES.
MAIN FORECAST CONCERNS ARE POTENTIAL FOR SHOWERS/ISOLATED THUNDER
THIS WEEKEND...AND AGAIN MIDWEEK...WITH LINGERING NEAR TO BELOW
NORMAL TEMPERATURES ON MOST DAYS. WITH CONSIDERABLE DRY AIRMASS TO
OVERCOME...WEAK WARM AIR ADVECTION/ISENTROPIC LIFT WILL STRUGGLE TO
SATURATE PROFILE ENOUGH TO PRODUCE PRECIPITATION. STRONGEST LIFT
WILL SKIRT NORTH OF THE CWA...ACROSS SOUTHERN SD...BUT DID RETAIN A
SMALL AREA OF SLIGHT CHANCE POPS TONIGHT IN CASE SHOWERS SLIP INTO
NORTHEAST NEB. POTENTIAL FOR WARM AIR ADVECTION-TYPE SHOWERS WILL
CONTINUE IN NORTHEAST NEB ON SATURDAY...BUT BULK OF THE CWA WILL
WAIT FOR FRONTAL PASSAGE FOR RAIN TO FALL. WITH STRONG UPPER-LEVEL
WAVE DROPPING ACROSS THE DAKOTAS INTO THE WESTERN GREAT
LAKES...FRONT WILL MOVE THROUGH THE CWA FROM SATURDAY NIGHT THROUGH
SUNDAY. FRONT DOES SEEM STRONG ENOUGH...WITH ENOUGH UPPER-LEVEL
SUPPORT...TO PRODUCE GOOD COVERAGE OF SHOWERS AS WELL AS ISOLATED
THUNDER FROM SATURDAY NIGHT INTO SUNDAY...AS MUCAPE /ELEVATED ABOVE
850MB/ INCREASES TO AROUND 500-1000 J/KG. MAY SEE A FEW SHOWERS
LINGERING INTO THROUGH SUNDAY MORNING...BUT BULK OF THE ACTIVITY
LOOKS LIKE IT WILL CLEAR ALL BUT THE SOUTHERNMOST COUNTIES BY SUNDAY
AFTERNOON. HAVE SPED DRYING BEHIND THE FRONT...AS MODELS AGREE ON
RAPID COOL/DRY AIR INTRUSION ON SUNDAY NIGHT/MONDAY BEHIND THE
FRONT. HAVE COOLED TEMPERATURES A BIT ON SUNDAY WITH FRONTAL
PASSAGE AND LINGERING SHOWERS...AS WELL AS IN POST-FRONTAL COOL AIR
ON MONDAY.
DRY PERIOD WILL BE SHORT-LIVED...AS STRONG AND MOISTURE-RICH RETURN
FLOW ON MONDAY NIGHT BRINGS A CHANCE OF SHOWERS/ISOLATED THUNDER
BACK INTO THE AREA AFTER MIDNIGHT...SPREADING FROM SOUTH TO NORTH.
NOSE OF SOUTHWESTERLY 850MB FLOW MAY NOT LINGER IN THE CWA TOO LONG
AS IT MAKES ITS WAY INTO IA/MN...BUT SHOULD BRING POTENTIAL FOR
SHRA/TSRA PARTICULARLY IN THE EASTERN CWA THROUGH TUESDAY NIGHT
BEFORE RISK PUSHES EASTWARD AND HIGH PRESSURE AGAIN SLIDES IN.
THURSDAY/FRIDAY LOOK MORE LIKELY TO BE DRY...AT LEAST WITH ENOUGH
UNCERTAINTY IN PRECIP TO LEAVE IT OUT OF THE FORECAST UNTIL MODEL
AGREEMENT IMPROVES.
MAYES
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
403 PM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT INTO SUNDAY WITH
MAINLY CLEAR SKIES AND SEASONABLY COOL TEMPERATURES. A COLD FRONT
WILL CROSS THE AREA SUNDAY NIGHT INTO MONDAY MORNING WITH SCATTERED
TO NUMEROUS SHOWERS...FOLLOWED BY CLEARING AND CHILLY TEMPERATURES
MONDAY NIGHT. THEREAFTER...HIGH PRESSURE WILL DOMINATE REGIONAL
WEATHER CONDITIONS FOR MUCH OF NEXT WEEK WITH FAIR WEATHER AND
GRADUALLY MODERATING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 341 PM EDT SATURDAY...FORECAST REMAINS GENERALLY ON TRACK
FOR TONIGHT AS UPPER LOW PRESSURE WEAKENS AND PULLS NORTHEAST INTO
THE CANADIAN MARITIMES....AND SFC HIGH PRESSURE ACROSS THE OHIO
VALLEY SLIDES TO THE MID-ATLANTIC BY SUNDAY MORNING. THUS THE IDEA
OF CLEARING SKIES THROUGH THE EVENING HOURS LOOKS REASONABLE AS
WINDS TREND LIGHT. DESPITE SOME EVIDENCE OF MODEST WESTERLY FLOW
ATOP THE NOCTURNAL PBL...PATCHY FOG STILL LOOKS LIKE GOOD BET IN
FAVORED LOCALES GIVEN AMBIENT GROUND MOISTURE REALLY HASN`T HAD A
SOLID PERIOD OF EVAPORATIVE DRYING TODAY AND WILL ACT TO SATURATE
NEAR SFC LAYERS AFTER MIDNIGHT. COULD EVEN SEE SOME PATCHY FROST
IN OUR COLDEST LOCALES OF THE DACKS/NERN VT AS WELL...BUT ONLY
LIMITED COVERAGE WARRANTS EXCLUSION OF ANY FROST HEADLINES AT THIS
POINT. LOWS GENERALLY IN THE 30S TO AROUND 40 IN THE
MOUNTAINS...AROUND 40 IN THE SLV AND IN THE 40S FOR THE CHAMPLAIN
VALLEY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 341 PM EDT SATURDAY...HIGH PRESSURE THEN SLOWLY SLIDES EAST
OFF THE MID ATLANTIC COAST DURING SUNDAY WITH SUNNY SKIES EXPECTED
AND MILDER TEMPERATURES IN THE 60S TO AROUND 70. WINDS BECOMING
SOUTHERLY AND TRENDING A TAD GUSTY BY AFTERNOON AS PBL P-GRAD
TIGHTENS SOMEWHAT BETWEEN AFOREMENTIONED HIGH AND A COLD FRONT OFF
TO OUR NORTHWEST. STRONGEST FLOW LIKELY TO OCCUR IN THE SLV WHERE
GUSTS TO 25 KT MOST PROBABLE.
BY SUNDAY NIGHT THE COLD FRONT THEN PROGRESSES FAIRLY QUICKLY SOUTH
AND EAST INTO OUR AREA ALONG WITH INCREASING CLOUDS AND CHANCES OF
SHOWERS. GIVEN FAIRLY NARROW BAND OF DEEPER MOISTURE ALONG THE
BOUNDARY AND IT`S RATHER QUICK PROGRESSION...QPF SHOULD
REMAIN LIGHT AND GENERALLY LESS THAN ONE QUARTER INCH WITH HIGHEST
TOTALS IN THE NRN MTNS. LOWS TRICKY GIVEN FRONTAL PASSAGE WITHIN A
FEW HOURS OF SUNRISE SO KEPT CLOSE TO BIAS-CORECTED MOS VALUES FROM
45 TO 55 FOR MOST SPOTS.
ANY LINGERING SHOWERS WILL THEN END DURING THE MORNING HOURS ON
MONDAY AS THE COLD FRONT CLEARS QUICKLY SOUTH AND EAST ALLOWING
FAIRLY STRONG COLD THERMAL ADVECTION TO TAKE OVER BY AFTERNOON ON
OCCASIONALLY GUSTY NORTHWESTERLY FLOW. INDEED...TEMPERATURES WILL
ONLY RECOVER A FEW DEGREES INTO THE 55 TO 65 RANGE AS LINGERING
STRATOCUMULUS SLOWLY THINS BY AFTERNOON.
THEN CLEAR...CALM AND QUITE CHILLY BY MONDAY NIGHT AS STRONGER 1030
HPA CANADIAN SFC HIGH SETTLES ATOP THE AREA. WIDESPREAD PATCHY FROST
AND/OR FOG A GOOD BET WITH OUR COLDEST LOCALES POSSIBLY SEEING A
HARD FREEZE. TOO FAR OUT AT THIS POINT TO COVER WITH HEADLINES...BUT
IMAGINE THIS WILL BE LIKELY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 400 PM EDT SATURDAY...EXCELLENT AGREEMENT BTWN GFS/GEM AND
ECMWF ON LARGE SCALE SYNOPTIC PATTERN THRU THURSDAY...BEFORE
SIGNIFICANT DIFFERENCES DEVELOP BY LATE NEXT WEEK. PATTERN WL
FEATURE BUILDING MID/UPPER LVL RIDGE OF HIGH PRES ACRS THE EASTERN
CONUS WITH 1030MB SFC HIGH PRES NEAR SLK ON 12Z TUES...SLOWLY
SHIFTING OFF THE EAST COAST BY THURSDAY. THIS WL RESULT IN DRY
CONDITIONS...WITH A LARGE DIURNAL SPREAD IN DAILY HIGH/LOW TEMPS
EXPECTED...PER DEEP DRY LAYER. PROGGED 85H TEMPS START NEAR 2C
TUES 12Z...BUT WARM TO NEAR 10C BY 00Z FRIDAY...AS WAA DEVELOPS ON
BACKSIDE OF SFC HIGH PRES. PROGGED 85H TEMPS WARM BTWN 4-6C ON
TUES AFTN...SUPPORTING HIGHS IN THE U50S MTNS TO U60S VALLEYS. ON
WEDS/THURS...85H TEMPS WARM BTWN 8-10C...SUPPORTING HIGHS BACK
INTO THE M60S MTNS TO M70S VALLEYS. SOUNDINGS SHOW VERY DRY AIR
MASS IN PLACE FOR MID WEEK...SO EXPECT AT OR BLW NORMAL LOWS WITH
READINGS IN THE U20S/L30S COLDER VALLEYS TO U40S/L50S NEAR LAKE
CHAMPLAIN...ON TUES NIGHT...THESE TEMPS WL WARM SEVERAL DEGREES
EACH NIGHT...WITH AREAS OF PATCHY FOG POSSIBLE. LOTS OF
UNCERTAINTY WITH MAGNITUDE/TIMING AND IMPACTS OF NEXT SYSTEM LATE
NEXT WEEK INTO THE WEEKEND. GIVEN THE PROGGED FAST FLW ALOFT WL
TREND TWD A MORE PROGRESSIVE GFS SOLUTION...WHICH SHOWS A CLOSED
MID/UPPER LVL CIRCULATION ACRS THE NORTHERN LAKES ON
FRIDAY...MOVING TWD THE NE CONUS BY SATURDAY. THIS WL PUSH VERY
WARM TEMPS INTO OUR REGION THURSDAY/FRIDAY...BEFORE A SFC COLD
FRNT SWINGS ACRS THE REGION ON SATURDAY...WITH A BAND OF SHOWERS.
GIVEN THE RIBBON OF ENHANCED MOISTURE/LIFT...EXPECTING A 6 TO 10
HOUR WINDOW OF PRECIP...BUT THIS SUBJECT TO CHANGE...ESPECIALLY IF
THE SYSTEM SLOWS DOWN...AS ADVERTISED BY THE GEM/ECMWF. THE ECMWF
SHOWS AN INITIAL SURGE OF WAA/MOISTURE IMPACTING OUR CWA ON
FRIDAY...WITH MAIN CLOSED CORE SYSTEM NOT IMPACTING OUR REGION
UNTIL SUNDAY/MONDAY OF THE FOLLOWING WEEK. WL MENTION CHC POPS
FRI/SAT...WITH MUCH ABOVE NORMAL TEMPS EXPECTED...ESPECIALLY
OVERNIGHT LOWS.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...AVIATION CHALLENGE THIS AFTN/EVENING WL BE
TIMING OF LOW CLOUDS DISSIPATING...FOLLOWED BY FOG/BR TONIGHT AT
SLK/MPV. A MOIST CYCLONIC UPSLOPE FLW WITH COLD AIR ALOFT CONTS TO
PRODUCE PLENTY OF STRATO CUMULUS CLOUDS ACRS OUR TAF SITES THIS
AFTN...WITH SOME BREAKS NOTED IN THE DOWNSLOPE AREAS...SUCH AS THE
WESTERN CPV NEAR PBG. EXPECT THESE LOW CLOUDS AND MVFR CONTS TO
PREVAIL THROUGH 21Z...BEFORE SLOWLY IMPROVING AT ALL SITES BTWN
00Z-02Z. THE COMBINATION OF SFC HIGH PRES AND CLRING SKIES SHOULD
ALLOW TEMPS TO REACH CROSS OVER VALUES AT SLK/MPV WITH AREAS OF
FOG/BR ANTICIPATED WITH LIFR CONDITIONS LIKELY BTWN 06Z-12Z
SUNDAY. INTERESTING THE RAP SHOWS A LLVL JET AT 975 MB OF 25 TO 30
KNTS FROM THE WEST DEVELOPING AT PBG/MSS AFT 06Z...WHICH COULD PRODUCE
SOME LOCALIZED WIND SHEAR AND TURBULENCE. FOG WL LIFT BTWN 12Z-
14Z SUNDAY...WITH SOUTH TO SOUTHWEST WINDS DEVELOPING AT 10 TO 15
KNOTS...WITH SOME HIGHER GUSTS POSSIBLE. GIVEN FAST JET ALOFT...EXPECT
SOME MID/UPPER LVL CLOUDS AHEAD OF NEXT SYSTEM TO STREAM QUICKLY
FROM WEST TO EAST ACRS OUR TAF SITES BY SUNDAY.
OUTLOOK 18Z SUNDAY THRU WEDNESDAY...
MID/UPPER LVL CLOUDS WL THICKEN AHEAD OF NEXT SFC BOUNDARY ON
SUNDAY AFTN. GIVEN NARROW RIBBON OF MOISTURE/LIFT...EXPECTING ONLY
A 2 TO 4 HOUR WINDOW OF PRECIP WITH POTENTIAL MVFR CONDITIONS ON
SUNDAY NIGHT INTO MONDAY. THE COMBINATION OF WINDS/CLOUDS WL
PREVENT FOG FROM DEVELOPING ON SUNDAY NIGHT. HIGH PRES WITH VFR
CONDITIONS RETURN FOR MONDAY THRU WEDS...WITH THE POTENTIAL FOR
DAILY FOG/FREEZING FOG WITH IFR CONDITIONS AT SLK/MPV EACH
MORNING.
&&
.EQUIPMENT...
AS OF 341 PM EDT SATURDAY...NOAA WEATHER RADIO STATION WXM 44...
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR DUE TO A DAMAGED ANTENNA. REPLACEMENT PARTS ARE ORDERED
AND THE REPAIR WORK HAS BEEN SCHEDULED FOR SEPTEMBER 17-20.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...TABER
AVIATION...TABER
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
341 PM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT INTO SUNDAY WITH
MAINLY CLEAR SKIES AND SEASONABLY COOL TEMPERATURES. A COLD FRONT
WILL CROSS THE AREA SUNDAY NIGHT INTO MONDAY MORNING WITH SCATTERED
TO NUMEROUS SHOWERS...FOLLOWED BY CLEARING AND CHILLY TEMPERATURES
MONDAY NIGHT. THEREAFTER...HIGH PRESSURE WILL DOMINATE REGIONAL
WEATHER CONDITIONS FOR MUCH OF NEXT WEEK WITH FAIR WEATHER AND
GRADUALLY MODERATING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 341 PM EDT SATURDAY...FORECAST REMAINS GENERALLY ON TRACK
FOR TONIGHT AS UPPER LOW PRESSURE WEAKENS AND PULLS NORTHEAST INTO
THE CANADIAN MARITIMES....AND SFC HIGH PRESSURE ACROSS THE OHIO
VALLEY SLIDES TO THE MID-ATLANTIC BY SUNDAY MORNING. THUS THE IDEA
OF CLEARING SKIES THROUGH THE EVENING HOURS LOOKS REASONABLE AS
WINDS TREND LIGHT. DESPITE SOME EVIDENCE OF MODEST WESTERLY FLOW
ATOP THE NOCTURNAL PBL...PATCHY FOG STILL LOOKS LIKE GOOD BET IN
FAVORED LOCALES GIVEN AMBIENT GROUND MOISTURE REALLY HASN`T HAD A
SOLID PERIOD OF EVAPORATIVE DRYING TODAY AND WILL ACT TO SATURATE
NEAR SFC LAYERS AFTER MIDNIGHT. COULD EVEN SEE SOME PATCHY FROST
IN OUR COLDEST LOCALES OF THE DACKS/NERN VT AS WELL...BUT ONLY
LIMITED COVERAGE WARRANTS EXCLUSION OF ANY FROST HEADLINES AT THIS
POINT. LOWS GENERALLY IN THE 30S TO AROUND 40 IN THE
MOUNTAINS...AROUND 40 IN THE SLV AND IN THE 40S FOR THE CHAMPLAIN
VALLEY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 341 PM EDT SATURDAY...HIGH PRESSURE THEN SLOWLY SLIDES EAST
OFF THE MID ATLANTIC COAST DURING SUNDAY WITH SUNNY SKIES EXPECTED
AND MILDER TEMPERATURES IN THE 60S TO AROUND 70. WINDS BECOMING
SOUTHERLY AND TRENDING A TAD GUSTY BY AFTERNOON AS PBL P-GRAD
TIGHTENS SOMEWHAT BETWEEN AFOREMENTIONED HIGH AND A COLD FRONT OFF
TO OUR NORTHWEST. STRONGEST FLOW LIKELY TO OCCUR IN THE SLV WHERE
GUSTS TO 25 KT MOST PROBABLE.
BY SUNDAY NIGHT THE COLD FRONT THEN PROGRESSES FAIRLY QUICKLY SOUTH
AND EAST INTO OUR AREA ALONG WITH INCREASING CLOUDS AND CHANCES OF
SHOWERS. GIVEN FAIRLY NARROW BAND OF DEEPER MOISTURE ALONG THE
BOUNDARY AND IT`S RATHER QUICK PROGRESSION...QPF SHOULD
REMAIN LIGHT AND GENERALLY LESS THAN ONE QUARTER INCH WITH HIGHEST
TOTALS IN THE NRN MTNS. LOWS TRICKY GIVEN FRONTAL PASSAGE WITHIN A
FEW HOURS OF SUNRISE SO KEPT CLOSE TO BIAS-CORECTED MOS VALUES FROM
45 TO 55 FOR MOST SPOTS.
ANY LINGERING SHOWERS WILL THEN END DURING THE MORNING HOURS ON
MONDAY AS THE COLD FRONT CLEARS QUICKLY SOUTH AND EAST ALLOWING
FAIRLY STRONG COLD THERMAL ADVECTION TO TAKE OVER BY AFTERNOON ON
OCCASIONALLY GUSTY NORTHWESTERLY FLOW. INDEED...TEMPERATURES WILL
ONLY RECOVER A FEW DEGREES INTO THE 55 TO 65 RANGE AS LINGERING
STRATOCUMULUS SLOWLY THINS BY AFTERNOON.
THEN CLEAR...CALM AND QUITE CHILLY BY MONDAY NIGHT AS STRONGER 1030
HPA CANADIAN SFC HIGH SETTLES ATOP THE AREA. WIDESPREAD PATCHY FROST
AND/OR FOG A GOOD BET WITH OUR COLDEST LOCALES POSSIBLY SEEING A
HARD FREEZE. TOO FAR OUT AT THIS POINT TO COVER WITH HEADLINES...BUT
IMAGINE THIS WILL BE LIKELY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 318 AM EDT SATURDAY...NWP GUIDANCE SUITE AT 00Z LARGELY THE SAME
AS PREVIOUSLY FORECAST WITH ADVERTISED QUIET STRETCH OF WEATHER.
A LARGE SFC ANTICYCLONE WILL BUILD EWD FROM THE GREAT LAKES MONDAY
NIGHT AND SETTLE ACROSS NRN NY INTO VT BY 12Z TUESDAY. WITH
DIMINISHING CLOUDS AND WIND...GOOD RADIATIVE COOLING WILL SETUP A
FROST/FREEZE SCENARIO FOR CENTRAL/ERN VT AND NRN NY AWAY FROM THE
CHAMPLAIN VALLEY. HAVE INCLUDED PATCHY/AREAS OF FROST ASSOCIATED
WITH TEMPERATURES NEAR FREEZING IN ABOVE MENTIONED AREAS. COLDEST
LOW TEMPS EXPECTED AROUND LAKE PLACID AND SARANAC LAKE (AROUND
28F)...AND LOCALLY NEAR 30F AROUND ISLAND POND/CANAAN IN FAR NERN
VT. LOWS WILL GENERALLY REMAIN IN THE UPR 30S IN THE IMMEDIATE
CHAMPLAIN VALLEY. ALSO...VALLEY FOG TYPICAL IN THE LOWER
PASSUMPSIC VALLEY...IMMEDIATE CT RIVER VALLEY...AND THE WINOOSKI
VALLEY WILL LIMIT FROST FORMATION IN THESE CENTRAL AND ERN VT
RIVER VALLEYS. OUTLYING AREAS AND SHELTERED VALLEYS WILL HAVE
BETTER PROSPECTS FOR FROST/FREEZE 06-12Z TUE.
SFC RIDGE MAKES FOR SEASONABLE AND PLEASANT WEATHER CONDITIONS
TUE-THU...AND STAYED CLOSE TO A MIX OF 00Z MEX-MOS AND MEX BIAS
CORRECTION ON TEMPERATURES. GENERALLY LOOKING AT A MODERATING TREND
WITH TEMPERATURES IN THE LOW-MID 60S FOR AFTN HIGHS TUESDAY...BUT
UP IN THE LOWER 70S WED AND THU. A WARM FRONT DEVELOPING TO OUR SW
AND DEVELOPING SWLY FLOW ALOFT BRINGS 20-30 POPS FOR -SHRA ON
FRIDAY WITH INCREASING CLOUDINESS. TEMPS LIKELY ABOVE NORMAL WITH
VALLEY HIGHS IN THE LOW-MID 70S ON FRIDAY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...AVIATION CHALLENGE THIS AFTN/EVENING WL BE
TIMING OF LOW CLOUDS DISSIPATING...FOLLOWED BY FOG/BR TONIGHT AT
SLK/MPV. A MOIST CYCLONIC UPSLOPE FLW WITH COLD AIR ALOFT CONTS TO
PRODUCE PLENTY OF STRATO CUMULUS CLOUDS ACRS OUR TAF SITES THIS
AFTN...WITH SOME BREAKS NOTED IN THE DOWNSLOPE AREAS...SUCH AS THE
WESTERN CPV NEAR PBG. EXPECT THESE LOW CLOUDS AND MVFR CONTS TO
PREVAIL THROUGH 21Z...BEFORE SLOWLY IMPROVING AT ALL SITES BTWN
00Z-02Z. THE COMBINATION OF SFC HIGH PRES AND CLRING SKIES SHOULD
ALLOW TEMPS TO REACH CROSS OVER VALUES AT SLK/MPV WITH AREAS OF
FOG/BR ANTICIPATED WITH LIFR CONDITIONS LIKELY BTWN 06Z-12Z
SUNDAY. INTERESTING THE RAP SHOWS A LLVL JET AT 975 MB OF 25 TO 30
KNTS FROM THE WEST DEVELOPING AT PBG/MSS AFT 06Z...WHICH COULD PRODUCE
SOME LOCALIZED WIND SHEAR AND TURBULENCE. FOG WL LIFT BTWN 12Z-
14Z SUNDAY...WITH SOUTH TO SOUTHWEST WINDS DEVELOPING AT 10 TO 15
KNOTS...WITH SOME HIGHER GUSTS POSSIBLE. GIVEN FAST JET ALOFT...EXPECT
SOME MID/UPPER LVL CLOUDS AHEAD OF NEXT SYSTEM TO STREAM QUICKLY
FROM WEST TO EAST ACRS OUR TAF SITES BY SUNDAY.
OUTLOOK 18Z SUNDAY THRU WEDNESDAY...
MID/UPPER LVL CLOUDS WL THICKEN AHEAD OF NEXT SFC BOUNDARY ON
SUNDAY AFTN. GIVEN NARROW RIBBON OF MOISTURE/LIFT...EXPECTING ONLY
A 2 TO 4 HOUR WINDOW OF PRECIP WITH POTENTIAL MVFR CONDITIONS ON
SUNDAY NIGHT INTO MONDAY. THE COMBINATION OF WINDS/CLOUDS WL
PREVENT FOG FROM DEVELOPING ON SUNDAY NIGHT. HIGH PRES WITH VFR
CONDITIONS RETURN FOR MONDAY THRU WEDS...WITH THE POTENTIAL FOR
DAILY FOG/FREEZING FOG WITH IFR CONDITIONS AT SLK/MPV EACH
MORNING.
&&
.EQUIPMENT...
AS OF 341 PM EDT SATURDAY...NOAA WEATHER RADIO STATION WXM 44...
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR DUE TO A DAMAGED ANTENNA. REPLACEMENT PARTS ARE ORDERED
AND THE REPAIR WORK HAS BEEN SCHEDULED FOR SEPTEMBER 17-20.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...BANACOS
AVIATION...TABER
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
125 PM EDT SAT SEP 14 2013
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL SHIFT FROM THE NEW ENGLAND
REGION INTO THE CANADIAN MARITIMES DURING THE DAY TODAY...GIVING WAY
TO HIGH PRESSURE FOR TONIGHT RIGHT THROUGH SUNDAY. A FRONT WILL
SWING DOWN FROM EAST CENTRAL CANADA SUNDAY NIGHT INTO MONDAY BEFORE
HIGH PRESSURE RETURNS FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1226 PM EDT SATURDAY...MINOR ADJUSTMENTS TO SKY COVER AND
LOWER HOURLY/MAX TEMPS BY A DEGREE RO TWO AS WE HEAD INTO THE
AFTERNOON HOURS. CHANGES VERY MINOR AND AS A WHOLE FORECAST
REMAINS IN GOOD SHAPE. PRIOR DISCUSSION BELOW...
UPDATE AS OF MID-MORNING TO INCREASE POPS SIGNIFICANTLY ACROSS FAR
NERN VT THROUGH THIS MORNING...THEN TAPER THINGS SLOWLY OFF. GYX
RADAR ESTIMATES OF OVER 3 INCHES JUST NORTHEAST ACROSS THE BORDER
IN COOS COUNTY NEAR DIXVILLE NOTCH SO CATEGORICAL/LIKELY POPS
(60-80%) LOOK REASONABLE. FURTHER WEST ACROSS THE REMAINDER OF
CENTRAL/NWRN VT/DACKS...JUST A FEW/SCT SHOWERS AND PATCHY DRIZZLE
ENDING BY NOONTIME OR SO AS UPPER LOW PIVOTS SLOWLY NORTH AND EAST
AWAY FROM THE REGION. CLOUDS TO DEPART SLOWER FROM THE DACKS EAST
HOWEVER AS ONE FINAL H5 VORT BAND STILL ON TRACK TO PIVOT THROUGH
THE AREA AROUND SUNSET. BEST WX TODAY ACROSS THE SLV WHERE PARTIAL
TO FULL SUN IS EXPECTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 333 AM EDT SATURDAY...NICE DAY ON TAP FOR SUNDAY WITH HIGH
PRESSURE TO OUR SOUTH...GIVING THE FORECAST AREA WSW SFC FLOW THRU
MUCH OF THE DAY...ALLOWING FOR MAINLY SUNNY/MSUNNY SKIES TO
PERSIST. TOWARDS THE LATE AFTNOON HRS...MDLS CONTINUE TO BRING
NEXT WX SYSTEM SE FROM CENTRAL QUEBEC IN THE FORM OF WK FRNTL
BOUNDARY. THIS SYSTEM HAS HAD MDL TIMING ISSUES AS TO ARRIVAL OF
PRECIP INTO THE ST LAW VALLEY/DACKS. LATEST CONSENSUS IS FOR -RW
TO START AROUND 22Z-23Z SUNDAY...OVERSPREADING THE REST OF CWA
THRU THE EARLY EVENING. OVERNGT IS WHERE HIGHEST POPS WILL OCCUR
AS FROPA COMMENCES ACROSS THE AREA. BY MORNING HRS MONDAY...BULK
OF RAIN WILL HAVE CLRD NORTHERN/WESTERN ZONES...W/ SLOW EXIT OF
CWA IN ITS ENTIRETY BY LATE AFTNOON. LIGHT QPF AROUND 0.10-0.20"
FOR EVENT. COOLER AIR COMING IN ON BACKSIDE OF FRNT WILL SLOWLY
FILTER FROM NW TO SE THRU THE DAY. THIS CAA COMBINED WITH
CLDS/RAIN FROM FRNT WILL LIMIT DAYTIME HIGHS. OVERALL SUNDAY
WARMEST PART OF FORECAST WITH HIGHS NEAR 70F FOR VALLEY LOCALES
AND 60S ELSEWHERE. MONDAY WILL SEE THE CWA MAINLY 50S WITH SOME
L60S IN SE VT AND CVLY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 318 AM EDT SATURDAY...NWP GUIDANCE SUITE AT 00Z LARGELY THE SAME
AS PREVIOUSLY FORECAST WITH ADVERTISED QUIET STRETCH OF WEATHER.
A LARGE SFC ANTICYCLONE WILL BUILD EWD FROM THE GREAT LAKES MONDAY
NIGHT AND SETTLE ACROSS NRN NY INTO VT BY 12Z TUESDAY. WITH
DIMINISHING CLOUDS AND WIND...GOOD RADIATIVE COOLING WILL SETUP A
FROST/FREEZE SCENARIO FOR CENTRAL/ERN VT AND NRN NY AWAY FROM THE
CHAMPLAIN VALLEY. HAVE INCLUDED PATCHY/AREAS OF FROST ASSOCIATED
WITH TEMPERATURES NEAR FREEZING IN ABOVE MENTIONED AREAS. COLDEST
LOW TEMPS EXPECTED AROUND LAKE PLACID AND SARANAC LAKE (AROUND
28F)...AND LOCALLY NEAR 30F AROUND ISLAND POND/CANAAN IN FAR NERN
VT. LOWS WILL GENERALLY REMAIN IN THE UPR 30S IN THE IMMEDIATE
CHAMPLAIN VALLEY. ALSO...VALLEY FOG TYPICAL IN THE LOWER
PASSUMPSIC VALLEY...IMMEDIATE CT RIVER VALLEY...AND THE WINOOSKI
VALLEY WILL LIMIT FROST FORMATION IN THESE CENTRAL AND ERN VT
RIVER VALLEYS. OUTLYING AREAS AND SHELTERED VALLEYS WILL HAVE
BETTER PROSPECTS FOR FROST/FREEZE 06-12Z TUE.
SFC RIDGE MAKES FOR SEASONABLE AND PLEASANT WEATHER CONDITIONS
TUE-THU...AND STAYED CLOSE TO A MIX OF 00Z MEX-MOS AND MEX BIAS
CORRECTION ON TEMPERATURES. GENERALLY LOOKING AT A MODERATING TREND
WITH TEMPERATURES IN THE LOW-MID 60S FOR AFTN HIGHS TUESDAY...BUT
UP IN THE LOWER 70S WED AND THU. A WARM FRONT DEVELOPING TO OUR SW
AND DEVELOPING SWLY FLOW ALOFT BRINGS 20-30 POPS FOR -SHRA ON
FRIDAY WITH INCREASING CLOUDINESS. TEMPS LIKELY ABOVE NORMAL WITH
VALLEY HIGHS IN THE LOW-MID 70S ON FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...AVIATION CHALLENGE THIS AFTN/EVENING WL BE
TIMING OF LOW CLOUDS DISSIPATING...FOLLOWED BY FOG/BR TONIGHT AT
SLK/MPV. A MOIST CYCLONIC UPSLOPE FLW WITH COLD AIR ALOFT CONTS TO
PRODUCE PLENTY OF STRATO CUMULUS CLOUDS ACRS OUR TAF SITES THIS
AFTN...WITH SOME BREAKS NOTED IN THE DOWNSLOPE AREAS...SUCH AS THE
WESTERN CPV NEAR PBG. EXPECT THESE LOW CLOUDS AND MVFR CONTS TO
PREVAIL THROUGH 21Z...BEFORE SLOWLY IMPROVING AT ALL SITES BTWN
00Z-02Z. THE COMBINATION OF SFC HIGH PRES AND CLRING SKIES SHOULD
ALLOW TEMPS TO REACH CROSS OVER VALUES AT SLK/MPV WITH AREAS OF
FOG/BR ANTICIPATED WITH LIFR CONDITIONS LIKELY BTWN 06Z-12Z
SUNDAY. INTERESTING THE RAP SHOWS A LLVL JET AT 975 MB OF 25 TO 30
KNTS FROM THE WEST DEVELOPING AT PBG/MSS AFT 06Z...WHICH COULD PRODUCE
SOME LOCALIZED WIND SHEAR AND TURBULENCE. FOG WL LIFT BTWN 12Z-
14Z SUNDAY...WITH SOUTH TO SOUTHWEST WINDS DEVELOPING AT 10 TO 15
KNOTS...WITH SOME HIGHER GUSTS POSSIBLE. GIVEN FAST JET ALOFT...EXPECT
SOME MID/UPPER LVL CLOUDS AHEAD OF NEXT SYSTEM TO STREAM QUICKLY
FROM WEST TO EAST ACRS OUR TAF SITES BY SUNDAY.
OUTLOOK 18Z SUNDAY THRU WEDNESDAY...
MID/UPPER LVL CLOUDS WL THICKEN AHEAD OF NEXT SFC BOUNDARY ON
SUNDAY AFTN. GIVEN NARROW RIBBON OF MOISTURE/LIFT...EXPECTING ONLY
A 2 TO 4 HOUR WINDOW OF PRECIP WITH POTENTIAL MVFR CONDITIONS ON
SUNDAY NIGHT INTO MONDAY. THE COMBINATION OF WINDS/CLOUDS WL
PREVENT FOG FROM DEVELOPING ON SUNDAY NIGHT. HIGH PRES WITH VFR
CONDITIONS RETURN FOR MONDAY THRU WEDS...WITH THE POTENTIAL FOR
DAILY FOG/FREEZING FOG WITH IFR CONDITIONS AT SLK/MPV EACH
MORNING.
&&
.EQUIPMENT...
AS OF 333 AM EDT SATURDAY...NOAA WEATHER RADIO STATION WXM 44...
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR DUE TO A DAMAGED ANTENNA. REPLACEMENT PARTS ARE ORDERED
AND THE REPAIR WORK HAS BEEN SCHEDULED FOR SEPTEMBER 17-20.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...JMG
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...TABER
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
232 AM EDT SAT SEP 14 2013
.SYNOPSIS...
MOSTLY CLOUDY SKIES WILL PERSIST TONIGHT...WITH SCATTERED LIGHT
SHOWERS AND PATCHY DRIZZLE MAINLY DOWNWIND OF LAKE ONTARIO AND
THE FINGER LAKES. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY ON
SATURDAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. FAIR AND
WARMER WEATHER IS EXPECTED ON SUNDAY AS THIS HIGH MOVES OFF THE
EAST COAST. A COLD FRONT WILL PASS THE REGION ON SUNDAY NIGHT AND
MONDAY WITH A CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...
JUST A QUICK UPDATE TO BRING MINS UP BY A DEGREE OR TWO OVRNGT
WITH THICK LOW CLDS NOT ALLOWING TEMPS TO FALL. TEMPS HV HELD
FAIRLY STEADY ARND 50/U40S AND EXPECT THEY WL ONLY FALL BY ANOTHER
2-3 DEGREES BY MRNG ESPECIALLY IN FINGER LKS REGION. SCTD
SHOWERS/PATCHY DRIZZLE STILL APPEAR TO BE ON TRACK.
PREV DISCOS BLO...
1030 PM UPDATE...
FORECAST IN EXCELLENT SHAPE. THE DAYSHIFT CAPTURED LAKE
SHOWERS/DRIZZLE QUITE WELL IN THE FORECAST AND THIS IS SUPPORTED
BY OBS OF LIGHT RAIN AND/OR DRIZZLE THROUGH THE FINGER LAKES NOW.
THE PREVIOUS AFD IS BELOW...
BATCH OF HEAVIER SHRA ACRS SE ZONES WILL MOVG OUT OF THE AREA BY
MID/LATE AFTN AS UPR LOW CONTINUES IT`S SLOW NEWD TREK. ANOTHER
VORT AXIS ACRS MI WILL MOV EWD ACRS THE FCST AREA LATER TNGT.
PLENTY OF LOW LVL MSTR PERSISTS TNGT...AND CONDITIONAL LAKE
INSTABILITY DVLPS. LOW LVL FLOW WILL MEANDER ARND 340 DEG...WITH
LAKE ONTARIO AND THE FINGER LAKES LIKELY AIDING DVLPMNT OF --SHRA
OR PATCHY -DZ. BEST BEST FOR LGT PCPN APPEARS TO BE ALONG AND W OF
THE I-81 CORRIDOR. GIVEN EXPECTATION OF CLDS TNGT XPCT MOST LOWS
TO BE IN THE M40S.
NAM/GFS STRONGLY SUGGEST THAT WE`LL BE CLEARING OUT EARLY TMRW
MRNG...BUT GEM HOLDS ONTO THE CLDS MUCH LONGER (WELL INTO THE
AFTN...SPCLY ERN ZONES). LATEST RUC PROFILES ALSO SUGGEST OVC
SKIES AT 11Z ACRS CNTRL NY. FOR THIS REASON WE WERE LEARY OF
CLEARING OUT THE SKIES AS QUICK AS MOS WOULD SUGGEST. CRNT FCST
MAY STILL BE TOO QUICK IN CLEARING THINGS OUT BUT TRENDED TWDS
SLOWER IMPRVMNT TMRW. MAXES TMRW ON THE COOL SIDE...GNRLY 60-65.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
SFC HI PRES RDG CRESTS OVER THE FCST AREA ON SAT NGT. POTNL FOR
PATCHY FROST SPCLY IN THE CATSKILLS AND COLDER SRN TIER VLYS. FOR
NOW WILL JUST MENTION POTNL IN THE HWO. OTRW SUNDAY LOOKS LIKE A
NICE DAY WITH MAXES MODERATING INTO THE U60S AND LOWER 70S. WE`LL
PRBLY SEE A BKN CI DECK MOVG INTO THE REGION DURING THE AFTN
AHEAD OF THE NXT S/WV. THIS WAVE WILL PUSH A CDFNT THRU ON SUNDAY
NGT...WITH POTNL FOR 2NDRY REINFORCING SHOT ON MONDAY. CHC/LIKELY
POPS FOR SUNDAY NGT...DCRSNG TO CHC POPS ON MONDAY. BEST CHC FOR
-SHRA ON MON APPEARS TO BE IN THE MRNG...WITH DRIER AIR AND
IMPRVNG SKY COVER ACRS NRN ZONES ON MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
230 AM UPDATE....
EXTENDED FCST REMAINS IN EXCELLENT SHAPE THIS MORNING AND NO
CHANGES NEEDED AT THE PRESENT TIME. MODERATING TEMPS EXPECTED OVER
THE COURSE OF THE WEEK AS WARM AIR ADVECTION INCREASES AS SFC HIGH
PRESSURE SLIDES OFF THE EAST COAST AS HEIGHTS BUILD ALOFT. NEXT
CHANCE FOR ORGANIZED PRECIP LOOKS TO HOLD OFF UNTIL THURSDAY WHEN
A WARM FRONT ATTACHED TO A STRONG AREA OF LOW PRESSURE ACROSS THE
CANADIAN PRAIRIE PROVINCES ADVANCES NORTH OF THE REGION. HIGH
TEMPS IN THE MIDDLE TO UPPER 60S ON TUESDAY WILL QUICKLY WARM INTO
THE LOWER TO MIDDLE 70S BY THU AS WARM AIR ADVECTION INCREASES.
PREVIOUS LONG TERM FORECAST...
AT THE BEGINNING OF THE PERIOD UPPER LEVEL TROF WILL MOVE
EAST OF AREA AS A FLAT RIDGE BUILDS ACROSS THE NORTHEAST. LATE IN
THE PERIOD AN UPPER LEVEL TROF DROPS INTO THE GREAT LAKES.
WILL CONTINUE WITH A DRY FORECAST MONDAY NIGHT THROUGH WEDNESDAY,
AS SFC HIGH PRES BUILDS SOUTH ACROSS THE AREA ON TUESDAY THEN
MOVES OFF THE NEW JERSEY COAST BY WEDNESDAY. TEMPS WILL WARM
DURING THE PERIOD AS FLOW SHIFTS FROM NORTHWEST TO SOUTHWEST.
WEDNESDAY NIGHT THROUGH FRIDAY, WILL CARRY SLIGHT CHC/CHC POPS AS
NEXT UPPER LEVEL TROF APPROACHES THE REGION AND ASSOCIATED SFC LOW
TRACKS FROM THE UPPER GREAT LAKES EAST ACROSS NEARBY SOUTHERN
CANADA. MEDIUM RANGE MODELS SHOW SIGNIFICANT TIMING DIFFERENCES
WITH THIS FEATURE, WITH THE ECMWF FASTER THAN THE GFS. AREA MAY BE
IMPACTED BY WARM FRONTAL SHOWERS THURSDAY/THURSDAY NIGHT FOLLOWED
BY SFC COLD FRONT ON FRIDAY. TEMPS WILL RANGE SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
LOW STRATUS PREVAILING OVER THE REGION EARLY THIS MORNING AS COLD
AIR FUNNELS OVER THE REGION BEHIND A DEPARTING UPPER TROUGH. AS A
RESULT...WIDESPREAD MVFR RESTRICTIONS EXPECTED AT ALL TERMINALS
THROUGH 12Z...WITH PERIODIC IFR CONDITIONS LIKELY AT BOTH BGM AND
ITH IN NORTHWEST LOW-LEVEL FLOW. FOR NOW...WE EXPECT CIGS TO
LARGELY REMAIN ABOVE ALTERNATE MIN THRESHOLDS AT BOTH ITH AND BGM.
AFTER 12Z...DRIER AIR WILL BEGIN WORKING INTO THE AREA WHICH
SHOULD ALLOW FOR A GRADUAL SCATTERING OUT OF LINGERING LOW STRATUS
BY 16Z. WINDS WILL INCREASE OUT OF THE NORTHWEST TODAY WITH SPEEDS
GENERALLY RANGING IN THE 10-15 KT RANGE... BEFORE WEAKENING AND
BECOMING CALM AFTER 00Z THIS EVENING. SKC CONDITIONS TO RETURN
AREAWIDE BY MID TO LATE AFTERNOON AS HIGH PRESSURE BUILDS INTO THE
REGION.
OUTLOOK...
SUN...MAINLY VFR...HOWEVER EARLY MORNING VSBY RESTRICTIONS
POSSIBLE AT ELM IN VALLEY FOG.
SUN NGT/MON...MVFR RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS.
MON NGT THROUGH WED...VFR UNDER HIGH PRESSURE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...HEDEN/PVN
SHORT TERM...
LONG TERM...CMG/RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
201 AM EDT SAT SEP 14 2013
.SYNOPSIS...
MOSTLY CLOUDY SKIES WILL PERSIST TONIGHT...WITH SCATTERED LIGHT
SHOWERS AND PATCHY DRIZZLE MAINLY DOWNWIND OF LAKE ONTARIO AND
THE FINGER LAKES. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY ON
SATURDAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. FAIR AND
WARMER WEATHER IS EXPECTED ON SUNDAY AS THIS HIGH MOVES OFF THE
EAST COAST. A COLD FRONT WILL PASS THE REGION ON SUNDAY NIGHT AND
MONDAY WITH A CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...
JUST A QUICK UPDATE TO BRING MINS UP BY A DEGREE OR TWO OVRNGT
WITH THICK LOW CLDS NOT ALLOWING TEMPS TO FALL. TEMPS HV HELD
FAIRLY STEADY ARND 50/U40S AND EXPECT THEY WL ONLY FALL BY ANOTHER
2-3 DEGREES BY MRNG ESPECIALLY IN FINGER LKS REGION. SCTD
SHOWERS/PATCHY DRIZZLE STILL APPEAR TO BE ON TRACK.
PREV DISCOS BLO...
1030 PM UPDATE...
FORECAST IN EXCELLENT SHAPE. THE DAYSHIFT CAPTURED LAKE
SHOWERS/DRIZZLE QUITE WELL IN THE FORECAST AND THIS IS SUPPORTED
BY OBS OF LIGHT RAIN AND/OR DRIZZLE THROUGH THE FINGER LAKES NOW.
THE PREVIOUS AFD IS BELOW...
BATCH OF HEAVIER SHRA ACRS SE ZONES WILL MOVG OUT OF THE AREA BY
MID/LATE AFTN AS UPR LOW CONTINUES IT`S SLOW NEWD TREK. ANOTHER
VORT AXIS ACRS MI WILL MOV EWD ACRS THE FCST AREA LATER TNGT.
PLENTY OF LOW LVL MSTR PERSISTS TNGT...AND CONDITIONAL LAKE
INSTABILITY DVLPS. LOW LVL FLOW WILL MEANDER ARND 340 DEG...WITH
LAKE ONTARIO AND THE FINGER LAKES LIKELY AIDING DVLPMNT OF --SHRA
OR PATCHY -DZ. BEST BEST FOR LGT PCPN APPEARS TO BE ALONG AND W OF
THE I-81 CORRIDOR. GIVEN EXPECTATION OF CLDS TNGT XPCT MOST LOWS
TO BE IN THE M40S.
NAM/GFS STRONGLY SUGGEST THAT WE`LL BE CLEARING OUT EARLY TMRW
MRNG...BUT GEM HOLDS ONTO THE CLDS MUCH LONGER (WELL INTO THE
AFTN...SPCLY ERN ZONES). LATEST RUC PROFILES ALSO SUGGEST OVC
SKIES AT 11Z ACRS CNTRL NY. FOR THIS REASON WE WERE LEARY OF
CLEARING OUT THE SKIES AS QUICK AS MOS WOULD SUGGEST. CRNT FCST
MAY STILL BE TOO QUICK IN CLEARING THINGS OUT BUT TRENDED TWDS
SLOWER IMPRVMNT TMRW. MAXES TMRW ON THE COOL SIDE...GNRLY 60-65.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
SFC HI PRES RDG CRESTS OVER THE FCST AREA ON SAT NGT. POTNL FOR
PATCHY FROST SPCLY IN THE CATSKILLS AND COLDER SRN TIER VLYS. FOR
NOW WILL JUST MENTION POTNL IN THE HWO. OTRW SUNDAY LOOKS LIKE A
NICE DAY WITH MAXES MODERATING INTO THE U60S AND LOWER 70S. WE`LL
PRBLY SEE A BKN CI DECK MOVG INTO THE REGION DURING THE AFTN
AHEAD OF THE NXT S/WV. THIS WAVE WILL PUSH A CDFNT THRU ON SUNDAY
NGT...WITH POTNL FOR 2NDRY REINFORCING SHOT ON MONDAY. CHC/LIKELY
POPS FOR SUNDAY NGT...DCRSNG TO CHC POPS ON MONDAY. BEST CHC FOR
-SHRA ON MON APPEARS TO BE IN THE MRNG...WITH DRIER AIR AND
IMPRVNG SKY COVER ACRS NRN ZONES ON MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT THE BEGINNING OF THE PERIOD UPPER LEVEL TROF WILL MOVE EAST OF
AREA AS A FLAT RIDGE BUILDS ACROSS THE NORTHEAST. LATE IN THE
PERIOD AN UPPER LEVEL TROF DROPS INTO THE GREAT LAKES.
WILL CONTINUE WITH A DRY FORECAST MONDAY NIGHT THROUGH WEDNESDAY,
AS SFC HIGH PRES BUILDS SOUTH ACROSS THE AREA ON TUESDAY THEN
MOVES OFF THE NEW JERSEY COAST BY WEDNESDAY. TEMPS WILL WARM
DURING THE PERIOD AS FLOW SHIFTS FROM NORTHWEST TO SOUTHWEST.
WEDNESDAY NIGHT THROUGH FRIDAY, WILL CARRY SLIGHT CHC/CHC POPS AS
NEXT UPPER LEVEL TROF APPROACHES THE REGION AND ASSOCIATED SFC LOW
TRACKS FROM THE UPPER GREAT LAKES EAST ACROSS NEARBY SOUTHERN
CANADA. MEDIUM RANGE MODELS SHOW SIGNIFICANT TIMING DIFFERENCES
WITH THIS FEATURE, WITH THE ECMWF FASTER THAN THE GFS. AREA MAY BE
IMPACTED BY WARM FRONTAL SHOWERS THURSDAY/THURSDAY NIGHT FOLLOWED
BY SFC COLD FRONT ON FRIDAY. TEMPS WILL RANGE SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
LOW STRATUS PREVAILING OVER THE REGION EARLY THIS MORNING AS COLD
AIR FUNNELS OVER THE REGION BEHIND A DEPARTING UPPER TROUGH. AS A
RESULT...WIDESPREAD MVFR RESTRICTIONS EXPECTED AT ALL TERMINALS
THROUGH 12Z...WITH PERIODIC IFR CONDITIONS LIKELY AT BOTH BGM AND
ITH IN NORTHWEST LOW-LEVEL FLOW. FOR NOW...WE EXPECT CIGS TO
LARGELY REMAIN ABOVE ALTERNATE MIN THRESHOLDS AT BOTH ITH AND BGM.
AFTER 12Z...DRIER AIR WILL BEGIN WORKING INTO THE AREA WHICH
SHOULD ALLOW FOR A GRADUAL SCATTERING OUT OF LINGERING LOW STRATUS
BY 16Z. WINDS WILL INCREASE OUT OF THE NORTHWEST TODAY WITH SPEEDS
GENERALLY RANGING IN THE 10-15 KT RANGE... BEFORE WEAKENING AND
BECOMING CALM AFTER 00Z THIS EVENING. SKC CONDITIONS TO RETURN
AREAWIDE BY MID TO LATE AFTERNOON AS HIGH PRESSURE BUILDS INTO THE
REGION.
OUTLOOK...
SUN...MAINLY VFR...HOWEVER EARLY MORNING VSBY RESTRICTIONS
POSSIBLE AT ELM IN VALLEY FOG.
SUN NGT/MON...MVFR RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS.
MON NGT THROUGH WED...VFR UNDER HIGH PRESSURE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...HEDEN/PVN
SHORT TERM...
LONG TERM...RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1218 AM EDT SAT SEP 14 2013
.SYNOPSIS...
MOSTLY CLOUDY SKIES WILL PERSIST TONIGHT...WITH SCATTERED LIGHT
SHOWERS AND PATCHY DRIZZLE MAINLY DOWNWIND OF LAKE ONTARIO AND
THE FINGER LAKES. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY ON
SATURDAY AS HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. FAIR AND
WARMER WEATHER IS EXPECTED ON SUNDAY AS THIS HIGH MOVES OFF THE
EAST COAST. A COLD FRONT WILL PASS THE REGION ON SUNDAY NIGHT AND
MONDAY WITH A CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...
JUST A QUICK UPDATE TO BRING MINS UP BY A DEGREE OR TWO OVRNGT
WITH THICK LOW CLDS NOT ALLOWING TEMPS TO FALL. TEMPS HV HELD
FAIRLY STEADY ARND 50/U40S AND EXPECT THEY WL ONLY FALL BY ANOTHER
2-3 DEGREES BY MRNG ESPECIALLY IN FINGER LKS REGION. SCTD
SHOWERS/PATCHY DRIZZLE STILL APPEAR TO BE ON TRACK.
PREV DISCOS BLO...
1030 PM UPDATE...
FORECAST IN EXCELLENT SHAPE. THE DAYSHIFT CAPTURED LAKE
SHOWERS/DRIZZLE QUITE WELL IN THE FORECAST AND THIS IS SUPPORTED
BY OBS OF LIGHT RAIN AND/OR DRIZZLE THROUGH THE FINGER LAKES NOW.
THE PREVIOUS AFD IS BELOW...
BATCH OF HEAVIER SHRA ACRS SE ZONES WILL MOVG OUT OF THE AREA BY
MID/LATE AFTN AS UPR LOW CONTINUES IT`S SLOW NEWD TREK. ANOTHER
VORT AXIS ACRS MI WILL MOV EWD ACRS THE FCST AREA LATER TNGT.
PLENTY OF LOW LVL MSTR PERSISTS TNGT...AND CONDITIONAL LAKE
INSTABILITY DVLPS. LOW LVL FLOW WILL MEANDER ARND 340 DEG...WITH
LAKE ONTARIO AND THE FINGER LAKES LIKELY AIDING DVLPMNT OF --SHRA
OR PATCHY -DZ. BEST BEST FOR LGT PCPN APPEARS TO BE ALONG AND W OF
THE I-81 CORRIDOR. GIVEN EXPECTATION OF CLDS TNGT XPCT MOST LOWS
TO BE IN THE M40S.
NAM/GFS STRONGLY SUGGEST THAT WE`LL BE CLEARING OUT EARLY TMRW
MRNG...BUT GEM HOLDS ONTO THE CLDS MUCH LONGER (WELL INTO THE
AFTN...SPCLY ERN ZONES). LATEST RUC PROFILES ALSO SUGGEST OVC
SKIES AT 11Z ACRS CNTRL NY. FOR THIS REASON WE WERE LEARY OF
CLEARING OUT THE SKIES AS QUICK AS MOS WOULD SUGGEST. CRNT FCST
MAY STILL BE TOO QUICK IN CLEARING THINGS OUT BUT TRENDED TWDS
SLOWER IMPRVMNT TMRW. MAXES TMRW ON THE COOL SIDE...GNRLY 60-65.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
SFC HI PRES RDG CRESTS OVER THE FCST AREA ON SAT NGT. POTNL FOR
PATCHY FROST SPCLY IN THE CATSKILLS AND COLDER SRN TIER VLYS. FOR
NOW WILL JUST MENTION POTNL IN THE HWO. OTRW SUNDAY LOOKS LIKE A
NICE DAY WITH MAXES MODERATING INTO THE U60S AND LOWER 70S. WE`LL
PRBLY SEE A BKN CI DECK MOVG INTO THE REGION DURING THE AFTN
AHEAD OF THE NXT S/WV. THIS WAVE WILL PUSH A CDFNT THRU ON SUNDAY
NGT...WITH POTNL FOR 2NDRY REINFORCING SHOT ON MONDAY. CHC/LIKELY
POPS FOR SUNDAY NGT...DCRSNG TO CHC POPS ON MONDAY. BEST CHC FOR
-SHRA ON MON APPEARS TO BE IN THE MRNG...WITH DRIER AIR AND
IMPRVNG SKY COVER ACRS NRN ZONES ON MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT THE BEGINNING OF THE PERIOD UPPER LEVEL TROF WILL MOVE EAST OF
AREA AS A FLAT RIDGE BUILDS ACROSS THE NORTHEAST. LATE IN THE
PERIOD AN UPPER LEVEL TROF DROPS INTO THE GREAT LAKES.
WILL CONTINUE WITH A DRY FORECAST MONDAY NIGHT THROUGH WEDNESDAY,
AS SFC HIGH PRES BUILDS SOUTH ACROSS THE AREA ON TUESDAY THEN
MOVES OFF THE NEW JERSEY COAST BY WEDNESDAY. TEMPS WILL WARM
DURING THE PERIOD AS FLOW SHIFTS FROM NORTHWEST TO SOUTHWEST.
WEDNESDAY NIGHT THROUGH FRIDAY, WILL CARRY SLIGHT CHC/CHC POPS AS
NEXT UPPER LEVEL TROF APPROACHES THE REGION AND ASSOCIATED SFC LOW
TRACKS FROM THE UPPER GREAT LAKES EAST ACROSS NEARBY SOUTHERN
CANADA. MEDIUM RANGE MODELS SHOW SIGNIFICANT TIMING DIFFERENCES
WITH THIS FEATURE, WITH THE ECMWF FASTER THAN THE GFS. AREA MAY BE
IMPACTED BY WARM FRONTAL SHOWERS THURSDAY/THURSDAY NIGHT FOLLOWED
BY SFC COLD FRONT ON FRIDAY. TEMPS WILL RANGE SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
730 PM UPDATE...
BOTTOM LINE AT NY SITES WILL BE MVFR AND IFR CONDITIONS CAUSING
FUEL ALTERNATES AND AT BGM AND ITH MAYBE ALTERNATE MINIMUMS. KAVP
A LITTLE HIGHER CIG BETWEEN 2K AND 4K FEET. IMPROVING TO VFR BY
SAT NOON.
UPPER LEVEL TROF WILL REMAIN OVER THE AREA THROUGH THIS TAF PERIOD
WITH A COOL NORTH TO NORTHWEST FLOW. THIS COLD FLOW OVER THE GREAT
LAKES AND FINGER LAKES WILL KEEP THE LOW LEVELS SATURATED TONIGHT.
THROUGH MID MORNING SATURDAY WIDESPREAD MVFR CIGS ARE EXPECTED
WITH IFR CIGS LIKELY AT KBGM/KITH LATE TONIGHT AND SOME IFR CIGS
EVEN THIS EVENING. SCATTERED LIGHT LAKE EFFECT RAIN SHOWERS ARE
ALSO EXPECTED OVERNIGHT MAINLY IN THE FINGER LAKES REGION. THIS
WAS INCLUDED IN JUST THE KITH TERMINAL THIS EVENING. KAVP WILL BE
ON THE EDGE OF THE CLOUDS AND WILL PROBABLY BOUNCE BETWEEN HIGH
MVFR AND VFR TONIGHT.
SATURDAY, LOW LEVEL DRYING WILL LEAD TO VFR CONDITIONS BY 16Z.
NORTHWEST WINDS 4 TO 8 KNOTS TONIGHT INCREASING TO 10 KTS AROUND
14Z SATURDAY.
OUTLOOK...
SAT NGT THROUGH SUN...VFR...BUT MAYBE SOME EARLY MORNING FOG/IFR
AT KELM.
SUN NGT/MON...SOME MAINLY MVFR RESTRICTIONS IN SCATTERED SHOWERS.
MON NGT THROUGH WED...VFR UNDER HIGH PRESSURE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...HEDEN/PVN
SHORT TERM...
LONG TERM...RRM
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
245 AM EDT SAT SEP 14 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL BUILD INTO THE MID ATLANTIC TODAY...
SETTLE OVER THE CAROLINAS TONIGHT...THEN MOVE OFFSHORE DURING THE
DAY SUNDAY. A WARMER SOUTHWEST FLOW WILL BRIEFLY RETURN TO THE AREA
LATE SUNDAY AND MONDAY. CANADIAN HIGH PRESSURE WILL BUILD INTO THE
REGION AGAIN MONDAY NIGHT AND TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 920 PM FRIDAY...
REST OF TONIGHT: QUIET AND COOL BUT WITH SOME CLOUDS. THE LATEST
SURFACE ANALYSIS SHOWS THE SYNOPTIC COLD FRONT HAVING PUSHED
SOUTHEAST OF THE FORECAST AREA... STRETCHING ACROSS SE NC... WHILE
SECONDARY TROUGHS WERE PUSHING SOUTHWARD OVER NE NC AND OVER NRN VA.
THE 850 MB TROUGH IS SEEN ON THE 00Z UPPER AIR ANALYSIS DROPPING SE
THROUGH CENTRAL NC... WITH ABUNDANT MOISTURE ALONG AND AHEAD OF THIS
FEATURE AT 850-750 MB. MODELS INCLUDING THE RAP INDICATE ENOUGH
FORCING FOR ASCENT AND MOISTURE CONTINUING THROUGH TONIGHT TO KEEP A
PERIOD OF MOSTLY CLOUDY SKIES OVER THE AREA... THICKEST AND MOST
EXPANSIVE IN THE NORTHEAST CWA WHERE THE LOWER LEVEL ONSHORE FLOW IS
DRAWING IN ATLANTIC MOISTURE ATTENDING THE AREA OF GREATEST LIFT.
THE POTENTIAL REMAINS FOR A FEW SPRINKLES IN THE NORTHEAST INCLUDING
ROANOKE RAPIDS / ROCKY MOUNT / WILSON / GOLDSBORO... HOWEVER THE
NEAR-SURFACE LAYER APPEARS TOO DRY FOR MUCH OF ANYTHING TO SURVIVE
TO THE GROUND... ESPECIALLY WITH DEW POINTS CONTINUING TO FALL
OVERNIGHT. CURRENT TEMPS ARE ON CLOSE PACE WITH FORECAST TEMPS...
AND SEE NO REASON TO ALTER EARLIER FORECAST LOWS RANGING FROM 54
NORTHEAST TO 63 SOUTHEAST. WITH THE LOWEST 50-100 MB REMAINING
FAIRLY MIXED AS THE COLDER/DENSER AIR SPILLS IN UNIFORMLY THROUGH
THIS LAYER... WE SHOULD SEE PERIODIC GUSTS TO AROUND 20 MPH
OVERNIGHT. -GIH
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 230 PM FRIDAY...
SATURDAY WILL BE AN ABSOLUTE PICTURESQUE DAY ACROSS CENTRAL NC.
A MODERATING CANADIAN PARENT SURFACE HIGH OVER THE OHIO VALLEY WILL
BUILD SOUTHWARD AND WILL BECOME CENTERED OVER THE AREA BY SUNDAY
MORNING. THIS WILL PROVIDE A SNEAK PEEK OF AUTUMN WITH PRIOR NIGHTS
COLD AIR ADVECTION HAVING THICKNESSES STARTING OUT A GOOD 30 METERS
BELOW NORMAL FOR MID SEPTEMBER. FULL SUN THICKNESSES SUPPORT HIGHS
IN THE LOWER 70S NW TO UPPER 70S SE...HOWEVER DAYTIME HEATING AND A
RELATIVELY MOIST LOW-LEVEL NELY FLOW MAY RESULT IN SCATTERED TO
POSSIBLY BROKEN AT TIME STRATOCU DECK BETWEEN 4 TO 6KFT WHICH COULD
IMPEDE TEMPERATURES A BIT...ESPECIALLY IN THE EAST.
A DRY AIRMASS WITH BOUNDARY LAYER DEWPOINTS IN THE MID TO UPPER 40S
AND GOOD RADIATIONAL COOLING CONDITIONS OVERNIGHT SHOULD RESULT
IN COOLEST TEMPERATURES OF THE SEASON. HOWEVER...AS LOW-LEVEL FLOW
OVER THE SOUTHEAST BEGINS TO VEER TO A MORE EASTERLY DIRECTION SAT
NIGHT. RESULTING WEAK WARM ADVECTION COULD PRODUCE SOME LOW-LEVEL
CLOUD COVER...MOST LIKELY ACROSS SOUTHERN PORTIONS OF FORECAST
AREA...BUT NAM BUFR SOUNDINGS SUGGEST THAT THESE LOW CLOUDS COULD
ARC NWD AS FAR AS THE TRIAD. SO WITH UNCERTAINTY WITH RESPECT
TO CLOUD COVER...LOWS COULD RANGE FROM THE UPPER 40S TO LOWER 50S
NORTH/NE TO LOWER/MID 50S NEAR THE SC BORDER...WITH THE POTENTIAL
FOR SOME OF THE CLIMATOLOGICALLY COOLER SPOTS TO FALL INTO THE MID
40S FOR AN HOUR OR TWO.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 245 AM SATURDAY...
COOL TO START THE WEEK... THEN WARMER AND STILL NO SIGNIFICANT RAIN
IN THE FORECAST...
A COLD FRONT IS EXPECTED TO APPROACH OUR REGION FROM THE NORTHWEST
ON MONDAY AFTERNOON. HOWEVER... LIMITED INSTABILITY... LOW LEVEL
MOISTURE RETURN... AND UPPER SUPPORT ALL POINT TOWARD ONLY ISOLATED
SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON AND EVENING. MODELS ARE
IN GOOD OVERALL AGREEMENT WITH THE TIMING OF THE FRONT (AFTERNOON
AND EVENING). THEREFORE THE CONFIDENCE IS HIGH WITH THIS FORECAST.
EXPECT PARTLY SUNNY SKIES MONDAY WITH A 20 PERCENT CHANCE OF A
SHOWER OR THUNDERSTORM DURING THE AFTERNOON AND EVENING. LOW LEVEL
THICKNESSES SUPPORT HIGHS RETURNING TO THE MID TO UPPER 80S. THE
FRONT SHOULD BE OVER NORTHERN SOUTH CAROLINA MONDAY EVENING... WITH
GOOD CAA INTO THE REGION FROM THE NNE. MODELS SUGGEST ENOUGH MID
LEVEL MOISTURE TO KEEP SKIES MOSTLY CLOUDY. LOWS IN THE MIXED
BOUNDARY LAYER WITH NE WINDS 10-15 MPH SHOULD STAY AT OR ABOVE 60 IN
THE SOUTH... WITH SOME MID TO UPPER 50S NORTH. TUESDAY... THE HIGH
PRESSURE (1028+ MB) IS FORECAST TO EXTEND FROM NY/PA SOUTHWARD INTO
NC/SC. FORECAST SOUNDINGS SUGGEST MUCH DRIER AIR WILL EXTEND WELL
SOUTHWARD INTO NC/SC BRINGING MOSTLY SUNNY SKIES. HIGHS 75-80
EXPECTED.
WED-THU... THE HIGH PRESSURE IS FORECAST TO SLOWLY MOVE EAST AND
SOUTH TO A POSITION OVER THE CAROLINAS BY THURSDAY. THIS SHOULD
ENSURE DRY AND SEASONABLY COOL NIGHTS... AND MOSTLY SUNNY WARM DAYS.
LOWS IN THE 50S. HIGHS WARMING FROM THE LOWER 80S WEDNESDAY INTO THE
MID 80S THURSDAY.
FRIDAY... UPPER RIDGING IS FORECAST TO BE SLOW TO RETREAT FROM THE
EASTERN SEABOARD. ANOTHER DAY OF SUNNY WARM CONDITIONS IS EXPECTED.
LOWS 60-65. HIGHS IN THE MID TO UPPER 80S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
24-HR TAF PERIOD:
VFR CONDITIONS WILL RULE THROUGH THE TAF PERIOD AS CANADIAN HIGH
PRESSURE BUILDS INTO CENTRAL NORTH CAROLINA. WINDS WILL BECOME NORTH
OR NORTHEASTERLY AT 8-13 KT BY 12Z...WITH SPORADIC GUSTS UP TO ~20
KT POSSIBLE AT THE FAY/RDU/RWI TERMINALS...ESPECIALLY AT FAY BETWEEN
09-15Z WHERE ONGOING PRESSURE RISES WILL BETTER COINCIDE WITH
DIURNAL HEATING/MIXING. WINDS WILL WEAKEN AND VEER TO THE ENE/EAST
BY LATE AFTERNOON AS THE MSLP GRADIENT WEAKENS AND DIURNAL HEATING
WANES.
LOOKING AHEAD:
VFR CONDITIONS WILL PREVAIL THROUGH THE DAY SUNDAY IN ASSOC/W HIGH
PRESSURE OVER THE REGION. SOME UNCERTAINTY PERSISTS WITH REGARD TO
WHETHER OR NOT BORDERLINE VFR/MVFR CEILINGS WILL DEVELOP OVER SOUTH
CAROLINA AND PERHAPS SOUTHERN NC (FAY TERMINAL) SUNDAY MORNING. AT
THIS TIME IT APPEARS THE BEST CHANCE FOR MVFR CEILINGS WILL BE WELL
SOUTH ACROSS SOUTH CAROLINA. AREAS OF FOG OR SUB-VFR CEILINGS CANNOT
BE RULED OUT EARLY MONDAY MORNING DUE TO INCREASING LOW-LEVEL
MOISTURE IN ASSOC/W A LIGHT SW RETURN FLOW. A BACK DOOR COLD FRONT
IS EXPECTED TO SURGE SOUTHWARD THROUGH CENTRAL NC LATE MONDAY AND
EARLY TUESDAY AS STRONG CANADIAN HIGH PRESSURE BUILDS INTO THE
MID-ATLANTIC AGAIN. EXPECT A FRONTAL PASSAGE VERY SIMILAR TO
YESTERDAY EVENING AND THIS MORNING...I.E. DRY/VFR WITH A SHORT
PERIOD OF BREEZY NORTHEAST WINDS IN THE WAKE OF THE FRONT MON NIGHT
AND TUE MORNING. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...HARTFIELD
SHORT TERM...CBL
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
152 AM EDT SAT SEP 14 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL BUILD INTO THE MID ATLANTIC TODAY...
SETTLE OVER THE CAROLINAS TONIGHT...THEN MOVE OFFSHORE DURING THE
DAY SUNDAY. A WARM SOUTHWEST FLOW WILL BRIEFLY RETURN TO THE AREA
LATE SUNDAY AND MONDAY. CANADIAN HIGH PRESSURE WILL BUILD INTO THE
REGION AGAIN MONDAY NIGHT AND TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 920 PM FRIDAY...
REST OF TONIGHT: QUIET AND COOL BUT WITH SOME CLOUDS. THE LATEST
SURFACE ANALYSIS SHOWS THE SYNOPTIC COLD FRONT HAVING PUSHED
SOUTHEAST OF THE FORECAST AREA... STRETCHING ACROSS SE NC... WHILE
SECONDARY TROUGHS WERE PUSHING SOUTHWARD OVER NE NC AND OVER NRN VA.
THE 850 MB TROUGH IS SEEN ON THE 00Z UPPER AIR ANALYSIS DROPPING SE
THROUGH CENTRAL NC... WITH ABUNDANT MOISTURE ALONG AND AHEAD OF THIS
FEATURE AT 850-750 MB. MODELS INCLUDING THE RAP INDICATE ENOUGH
FORCING FOR ASCENT AND MOISTURE CONTINUING THROUGH TONIGHT TO KEEP A
PERIOD OF MOSTLY CLOUDY SKIES OVER THE AREA... THICKEST AND MOST
EXPANSIVE IN THE NORTHEAST CWA WHERE THE LOWER LEVEL ONSHORE FLOW IS
DRAWING IN ATLANTIC MOISTURE ATTENDING THE AREA OF GREATEST LIFT.
THE POTENTIAL REMAINS FOR A FEW SPRINKLES IN THE NORTHEAST INCLUDING
ROANOKE RAPIDS / ROCKY MOUNT / WILSON / GOLDSBORO... HOWEVER THE
NEAR-SURFACE LAYER APPEARS TOO DRY FOR MUCH OF ANYTHING TO SURVIVE
TO THE GROUND... ESPECIALLY WITH DEW POINTS CONTINUING TO FALL
OVERNIGHT. CURRENT TEMPS ARE ON CLOSE PACE WITH FORECAST TEMPS...
AND SEE NO REASON TO ALTER EARLIER FORECAST LOWS RANGING FROM 54
NORTHEAST TO 63 SOUTHEAST. WITH THE LOWEST 50-100 MB REMAINING
FAIRLY MIXED AS THE COLDER/DENSER AIR SPILLS IN UNIFORMLY THROUGH
THIS LAYER... WE SHOULD SEE PERIODIC GUSTS TO AROUND 20 MPH
OVERNIGHT. -GIH
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 230 PM FRIDAY...
SATURDAY WILL BE AN ABSOLUTE PICTURESQUE DAY ACROSS CENTRAL NC.
A MODERATING CANADIAN PARENT SURFACE HIGH OVER THE OHIO VALLEY WILL
BUILD SOUTHWARD AND WILL BECOME CENTERED OVER THE AREA BY SUNDAY
MORNING. THIS WILL PROVIDE A SNEAK PEEK OF AUTUMN WITH PRIOR NIGHTS
COLD AIR ADVECTION HAVING THICKNESSES STARTING OUT A GOOD 30 METERS
BELOW NORMAL FOR MID SEPTEMBER. FULL SUN THICKNESSES SUPPORT HIGHS
IN THE LOWER 70S NW TO UPPER 70S SE...HOWEVER DAYTIME HEATING AND A
RELATIVELY MOIST LOW-LEVEL NELY FLOW MAY RESULT IN SCATTERED TO
POSSIBLY BROKEN AT TIME STRATOCU DECK BETWEEN 4 TO 6KFT WHICH COULD
IMPEDE TEMPERATURES A BIT...ESPECIALLY IN THE EAST.
A DRY AIRMASS WITH BOUNDARY LAYER DEWPOINTS IN THE MID TO UPPER 40S
AND GOOD RADIATIONAL COOLING CONDITIONS OVERNIGHT SHOULD RESULT
IN COOLEST TEMPERATURES OF THE SEASON. HOWEVER...AS LOW-LEVEL FLOW
OVER THE SOUTHEAST BEGINS TO VEER TO A MORE EASTERLY DIRECTION SAT
NIGHT. RESULTING WEAK WARM ADVECTION COULD PRODUCE SOME LOW-LEVEL
CLOUD COVER...MOST LIKELY ACROSS SOUTHERN PORTIONS OF FORECAST
AREA...BUT NAM BUFR SOUNDINGS SUGGEST THAT THESE LOW CLOUDS COULD
ARC NWD AS FAR AS THE TRIAD. SO WITH UNCERTAINTY WITH RESPECT
TO CLOUD COVER...LOWS COULD RANGE FROM THE UPPER 40S TO LOWER 50S
NORTH/NE TO LOWER/MID 50S NEAR THE SC BORDER...WITH THE POTENTIAL
FOR SOME OF THE CLIMATOLOGICALLY COOLER SPOTS TO FALL INTO THE MID
40S FOR AN HOUR OR TWO.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 215 PM FRIDAY...
SUNDAY WILL BEGIN AN EXTENDED PERIOD OF FAIRLY WEAK AND MORE ZONAL
UPPER LEVEL FLOW. EXCEPT FOR A COUPLE OF COLD FRONTS MOVING THROUGH
THE AREA...FIRST ON MONDAY EVENING AND THEN A POTENTIALLY WETTER
SYSTEM ASSOCIATED WITH A FAIRLY PROGRESSIVE UPPER LEVEL LOW ON
FRIDAY...THE MAJORITY OF THE LONG TERM WILL BE DRY AND COOL WITH
TEMPERATURES WITHIN FIVE DEGREES OF SEASONAL NORMALS.
REGARDING THE COLD FRONT EXPECTED TO MOVE THROUGH NORTH CAROLINA ON
MONDAY AND MONDAY NIGHT...THE FRONT LOOKS MOSTLY DRY BUT FAVORABLE
DIURNAL TIMING AND POSSIBLE INTERACTION WITH A SEA BREEZE FRONT IN
THE EAST MAKE SHOWERS POSSIBLE...ESPECIALLY IN THE SOUTHEAST. GFS
FORECAST SOUNDINGS VIEWED IN BUFKIT SHOW DRY ADIABATIC LAPSE RATES
UP TO 800 MB BUT VERY DRY DEWPOINTS IN THE LOW LEVELS...LIMITING THE
AMOUNT OF CAPE AVAILABLE FOR THE AFTERNOON AT SITES WHERE
NORTHWESTERLY FLOW TAKES OVER BY PEAK HEATING. SLIGHTLY MORE CAPE
(BUT STILL LESS THAN 100 J/KG) WILL BE AVAILABLE TO THE SOUTHEASTERN
TIER OF COUNTIES IN THE CWA. ALL IN ALL EXPECTING A NON-EVENT WITH
SOME SCATTERED SHOWERS AROUND THE AREA.
THE SECOND...AND POTENTIALLY MORE CONCERNING SYSTEM IS ASSOCIATED
WITH A MIGRATORY SURFACE LOW LOW THAT WILL MOVE SOUTHEAST ALONG THE
FRONT OF THE UPPER LEVEL RIDGE...INTO THE CAROLINAS FOR FRIDAY AND
SATURDAY. AT THIS TIME THE GFS SHOWS THIS SYSTEM ACCOMPANIED BY A
CLOSED UPPER LEVEL LOW...WHICH COULD HELP TO PROVIDE THE NECESSARY
DYNAMICS FOR CONVECTION ON FRIDAY. THE ECMWF HOWEVER IS SHOWING A
LESS ROBUST FRONTAL SYSTEM WITHOUT A CLOSED UPPER LOW AT THIS TIME
AND FRANKLY IT IS TOO EARLY TO TELL WHAT WILL HAPPEN. FOR NOW WILL
INCLUDE INCREASING CHANCE POPS INTO FRIDAY EVENING.
HIGH TEMPERATURES THROUGH THE PERIOD WILL RANGE FROM THE LOW 70S TO
MIDDLE 80S WITH LOWS IN THE MIDDLE 50S TO LOW 60S...VERY SEASONAL
FOR MID-SEPTEMBER.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 145 AM SATURDAY...
24-HR TAF PERIOD:
VFR CONDITIONS WILL RULE THROUGH THE TAF PERIOD AS CANADIAN HIGH
PRESSURE BUILDS INTO CENTRAL NORTH CAROLINA. WINDS WILL BECOME NORTH
OR NORTHEASTERLY AT 8-13 KT BY 12Z...WITH SPORADIC GUSTS UP TO ~20
KT POSSIBLE AT THE FAY/RDU/RWI TERMINALS...ESPECIALLY AT FAY BETWEEN
09-15Z WHERE ONGOING PRESSURE RISES WILL BETTER COINCIDE WITH
DIURNAL HEATING/MIXING. WINDS WILL WEAKEN AND VEER TO THE ENE/EAST
BY LATE AFTERNOON AS THE MSLP GRADIENT WEAKENS AND DIURNAL HEATING
WANES.
LOOKING AHEAD:
VFR CONDITIONS WILL PREVAIL THROUGH THE DAY SUNDAY IN ASSOC/W HIGH
PRESSURE OVER THE REGION. SOME UNCERTAINTY PERSISTS WITH REGARD TO
WHETHER OR NOT BORDERLINE VFR/MVFR CEILINGS WILL DEVELOP OVER SOUTH
CAROLINA AND PERHAPS SOUTHERN NC (FAY TERMINAL) SUNDAY MORNING. AT
THIS TIME IT APPEARS THE BEST CHANCE FOR MVFR CEILINGS WILL BE WELL
SOUTH ACROSS SOUTH CAROLINA. AREAS OF FOG OR SUB-VFR CEILINGS CANNOT
BE RULED OUT EARLY MONDAY MORNING DUE TO INCREASING LOW-LEVEL
MOISTURE IN ASSOC/W A LIGHT SW RETURN FLOW. A BACK DOOR COLD FRONT
IS EXPECTED TO SURGE SOUTHWARD THROUGH CENTRAL NC LATE MONDAY AND
EARLY TUESDAY AS STRONG CANADIAN HIGH PRESSURE BUILDS INTO THE
MID-ATLANTIC AGAIN. EXPECT A FRONTAL PASSAGE VERY SIMILAR TO
YESTERDAY EVENING AND THIS MORNING...I.E. DRY/VFR WITH A SHORT
PERIOD OF BREEZY NORTHEAST WINDS IN THE WAKE OF THE FRONT MON NIGHT
AND TUE MORNING. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...HARTFIELD
SHORT TERM...CBL
LONG TERM...RTE
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
100 AM EDT SAT SEP 14 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL BRING COOLER CONDITIONS FOR THE
WEEKEND. A DRY COLD FRONT WILL MOVE THROUGH BY EARLY TUESDAY
FOLLOWED BY YET ANOTHER COOL AND DRY CANADIAN HIGH PRESSURE SYSTEM.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 905 PM FRIDAY...LATEST WATER VAPOR IMAGERY...WVI...LOOPS
ILLUSTRATE THE EVOLUTION OF THE UPPER TROF ACROSS THE EASTERN U.S.
VIA WVI...DRIER AIR IN THE MID AND UPPER LEVELS HAS PUSHED ACROSS
THE ILM CWA. VARIOUS MODEL TIME HEIGHTS ACROSS LOCATIONS WITHIN
THE FA INDICATE LOW LEVEL MOISTURE TO STICK AROUND UNTIL THE
UPPER TROF AXIS PUSHES ACROSS THE FA...WHICH IS PROGGED TO OCCUR
DURING SATURDAY EARLY ON WITHIN THE SHORT TERM PERIOD. AS A
RESULT...HAVE INCREASED CLOUD COVERAGE OVERNIGHT INTO
SATURDAY...WITH UPSTREAM SFC OBS AND IR IMAGERY INDICATING A
RATHER WIDESPREAD AREA OF SC AND AC DEVELOPING BEHIND THE NE
SURGE. AS FOR POPS...THE EXTREME SOUTHERN PORTIONS COULD SEE AN
ISOLATED TSTORM THRU MID-EVENING OTHERWISE NO POPS. MODEL UPPER
AIR SOUNDINGS INDICATE A DECENT CONVECTIVE CAP/LID IN THE
MID-LEVELS PREVENTING CU FROM DEVELOPING IN THE VERTICAL DURING
THE PRE-DAWN SAT HRS. THE NE SURGE WILL WORK ITS WAY FROM NORTH TO
SOUTH WITH DRIER AIR...IE. LOWER DEWPOINTS...ADVECTING ACROSS THE
FA. THE LEADING EDGE OF THIS SURGE EXTENDS BETWEEN CAPE LOOKOUT
AND ROCKY MOUNT...AND SHOULD PUSH SOUTH OF THE ILM CWA BEFORE
DAYBREAK SAT. THE CURRENT MIN TEMP FORECAST REMAINS ON TARGET WITH
LITTLE TO NO TWEAKING NEEDED.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...COOL HIGH PRESSURE WILL BUILD DOWN INTO THE
CAROLINAS OVER THE WEEKEND. THE CENTER OF THE HIGH AT THE SURFACE
WILL SHIFT FROM THE OHIO VALLEY EARLY SATURDAY TO THE DELMARVA
COAST BY SUNDAY AFTERNOON. THEREFORE WINDS WILL START OUT
NORTHERLY BUT WILL VEER AROUND AS THE HIGH MOVES EAST BECOMING
MORE ON SHORE AND EASTERLY THROUGH THE WEEKEND. THIS WILL ADVECT
MOISTURE OFF THE ATLANTIC IN THE LOWER LEVELS WHILE IN THE MID TO
UPPER LEVELS THERE WILL BE PLENTY OF DRY AIR AND SUBSIDENCE AS H5
TROUGH CLEARS THE COAST LEAVING A DEEPER NW TO NORTHERLY FLOW
REINFORCING IT. THE OVERALL MOISTURE THROUGH THE COLUMN WILL
THEREFORE BE LESS THAN 1.5 INCHES BUT MOISTURE PROFILES AND
SOUNDING DATA CONTINUE TO SHOW THIS LOW LEVEL MOISTURE UNDERNEATH
THE SUBSIDENCE INVERSION. THIS LOW LEVEL MOISTURE WILL BE
REINFORCED WITH THE EASTERLY FLOW THROUGH THE FIRST FEW THOUSAND
FEET THROUGH MUCH OF THE WEEKEND. THIS COULD PRODUCE SOME LOWER
CLOUDS SAT AFTN THROUGH SUNDAY. MODELS DO SHOW WARMING ABOVE A
VERY SHALLOW COOL LAYER WHICH COULD COMBINE WITH ON SHORE FLOW IN
THE LOW LEVELS TO PRODUCE SOME CLOUDS. THE NAM IS MUCH MORE
AGGRESSIVE WITH CLOUDS AND SHOWS SOME SPOTTY PCP...MAINLY CLOSER
TO THE COAST...BUT FOR NOW WILL KEEP BELOW MOSTLY CLOUDY AT ANY
GIVEN TIME PERIOD AND KEEP POPS OUT OF FORECAST.
RELATIVELY COOLER AND DRIER AIR MASS WILL SETTLE UPON THE AREA
WITH TEMPS RUNNING BELOW NORMAL. EXPECT READINGS CLOSER TO 80 BOTH
DAYS. OVERNIGHT LOWS WILL DROP INTO THE LOWER HALF OF THE 60S MOST
PLACES WITH TRADITIONALLY COOLER SPOTS DROPPING JUST BELOW 60. INLAND
AREAS SHOULD EXPERIENCE MUCH DRIER AIR WITH DEWPOINTS DOWN IN THE
MID 50S. GRADIENT WILL RUN FROM NW TO SE WITH HIGHEST DEWPOINT
TEMPS CLOSER TO WINYAH BAY. THEREFORE EXPECT LOWEST TEMPS INLAND. THE
MOIST EASTERLY FETCH OFF THE WATERS COULD AFFECT THE CLOUD COVER
AND IN TURN WOULD INFLUENCE THE TEMPS DEPENDING ON THE AMOUNT OF
CLOUD COVER WE GET.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...AN OVERALL COOL AND DRY WEEK WILL BE BRACKETED
BY WEAK COLD FRONTS...CREATING THE ONLY SLIGHT PRECIP CHANCES FOR
THE PERIOD.
MONDAY STARTS WITH CONTINUED 5H TROUGHING ACROSS THE EAST WITH BROAD
RIDGING AT THE SURFACE EXTENDING ACROSS THE SOUTHEAST. ISOLATED
CONVECTION WILL BE POSSIBLE MONDAY AS TEMPS CLIMB TO ABOVE CLIMO
VALUES AND COMBINE WITH LOWERED THICKNESSES BENEATH THE 5H TROUGH.
QUITE A BIT OF DRY AIR ABOVE THE BOUNDARY LAYER WILL PRECLUDE MUCH
CONVECTION...BUT SCHC IS WARRANTED DURING THE AFTN/EVE ALONG THE SEA
BREEZE...AND THEN AREA-WIDE LATE MONDAY INTO TUESDAY AS WEAK COLD
FRONT APPROACHES. AGAIN...EXPECT ISOLATED COVERAGE AT BEST...BUT
INCREASING MOISTURE POOLING AHEAD OF THE COLD FRONT RAISES PWATS TO
1.6-1.7 INCHES WHICH WILL SUPPORT SCHC SHOWERS INTO TUESDAY MORNING.
TUE-FRI...COOL HIGH PRESSURE BUILDS DOWN FROM THE NORTH WITH MUCH
DRIER AIR AND TEMPS AROUND OR BELOW CLIMO...RISING SLOWLY TOWARDS
THE END OF THE WEEK DUE TO AIR MASS MODIFICATION. A SECOND COLD
FRONT WILL APPROACH FROM THE NW ON FRIDAY...BUT LITTLE MOISTURE
RETURN AHEAD OF THIS FEATURE WILL LIMIT OVERALL PRECIP POTENTIAL AND
WILL KEEP POP SILENT FOR D7.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...SCT-BKN MID LEVEL CLOUDS CAN BE EXPECTED EARLY THIS
MORNING. SHOWERS THROUGH SUNRISE SHOULD OCCUR MAINLY OFFSHORE.
MODELS INDICATES LOW/MID LEVEL CIGS (ABOVE 3000 FT) WILL CONTINUE
THROUGHOUT THIS TAF PERIOD. CONFIDENCE REMAINS LOW BUT MVFR CIGS
COULD DEVELOP AT THE COASTAL TERMINALS LATE MORNING/EARLY AFTERNOON
AND INLAND TERMINALS MID TO LATE AFTERNOON AS LOW LEVEL MOISTURE
INCREASES FROM OFF THE ATLANTIC. MVFR CIGS SHOULD BECOME MORE LIKELY
TOWARDS THE END OF THE TAF VALID PERIOD. NE WINDS WILL GRADUALLY
INCREASE IN SPEED EARLY THIS MORNING...WITH GUSTS TO 15-20 KNOTS
POSSIBLE AFTER SUNRISE. ISOLATED SHOWERS WILL BE POSSIBLE BY
AFTERNOON MAINLY AT THE COASTAL TERMINALS.
EXTENDED OUTLOOK...VFR SATURDAY AFTERNOON AND SUNDAY. MORNING FOG
POSSIBLE MONDAY. SLIGHT CHANCE OF SHOWERS LATE MONDAY THROUGH
WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM SATURDAY...BASED ON UPSTREAM OBSERVATIONS NEAR CAPE
LOOKOUT AND THE LATEST TWO RUNS OF THE HRRR MODEL I AM INCREASING
FORECAST WIND SPEEDS OVER THE NEXT SEVERAL HOURS TO 15-20 KNOTS.
THIS IS THE LONG-AWAITED SURGE MOVING SOUTH AHEAD OF CANADIAN HIGH
PRESSURE OVER THE WESTERN GREAT LAKES. SEAS CURRENTLY 2-3 FEET WILL
BEGIN TO BUILD WITH A SHORT PERIOD CHOP TOWARD DAYBREAK. PREVIOUS
DISCUSSION FROM 930 PM FOLLOWS...
SCEC REMAINS IN EFFECT FOR ALL WATERS DURING SATURDAY. THE COLD
FRONT MOVED SOUTH OF THE ILM COASTAL WATERS LATE THIS AFTERNOON. THE
FOCUS TURNS TOWARD THE NE SURGE LATER TONIGHT INTO SATURDAY. MODELS
INDICATE THE NE DRY AIR SURGE TO WORK ITS WAY ACROSS THE ILM WATERS
FROM NORTH TO SOUTH DURING THE SAT PRE-DAWN HRS. CURRENTLY THE
LEADING EDGE WAS IN CLOSE PROXIMITY OF CAPE LOOKOUT. WITH THE ILM
WATERS LYING BETWEEN THE COLD FRONT AND THE 1020+ MB HIGH OVER THE
GREAT LAKES OVERNIGHT...THE SFC PG WILL ALSO TIGHTEN ACROSS THE
LOCAL WATERS. THE LEADING EDGE OF THE NE SURGE SHOULD PUSH SOUTH OF
THE ILM WATERS BY SUNRISE SATURDAY. WILL CONTINUE THE TREND FOR WIND
SPEEDS INCREASING OVERNIGHT TO AROUND 15 KT WITH OCCASIONAL GUSTS TO
20 KT. SIGNIFICANT SEAS 2 TO 3 FT THIS EVENING...WILL BUILD TO 3 TO
5 FT BY DAYBREAK ACROSS THE ILM NC WATERS...SLIGHTLY LAGGING ACROSS
THE ILM SC WATERS. THE 3 TO 6 SECOND PERIOD WIND DRIVEN WAVES WILL
LIKELY DOMINATE THE SEAS SPECTRUM...WITH A CONTINUED UNDERLYING 1 TO
2 FOOT 8 TO 9 SECOND EASTERLY GROUND SWELL REMAINING PRESENT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH
AS IT SHIFTS FROM THE GREAT LAKES TO THE DELMARVA COAST THROUGH
THE WEEKEND. NORTHEASTERLY FLOW WILL VEER AROUND BECOMING MORE ON
SHORE AS THE HIGH MOVES EAST REMAINING NORTH OF WATERS. SURGE OF
COOL AND DRY AIR ON SATURDAY WILL PRODUCE WINDS UP AROUND 15 KTS
AND CLOSER TO 20 KTS IN OUTER WATERS WITH FREQUENT HIGHER GUSTS.
INCLUDED A PRECAUTIONARY SCEC HEADLINE FOR SAT FORECAST. WINDS
WILL SLOWLY DIMINISH ON SUNDAY AS AIR MASS SLOWLY MODIFIES AND
GRADIENT WEAKENS. SIGNIFICANT SEAS WILL SEE A RANGE OF 3-5 FEET
SATURDAY FALLING DOWN TO 2-4 FEET SUNDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...LIGHT AND VARIABLE WINDS WILL VEER THROUGH
MANY COMPASS DIRECTIONS ON MONDAY BEFORE A COLD FRONT
APPROACHES...AND CROSSES THE WATERS INTO TUESDAY MORNING. THIS
FRONT IS IN ADVANCE OF A SURFACE HIGH PRESSURE WHICH WILL RIDGE
DOWN THE COAST THROUGH MID-WEEK...CREATING A PINCHED GRADIENT AND
INCREASED NE WINDS THROUGH THE REMAINDER OF THE PERIOD. WINDS
TUESDAY WILL STEADILY INCREASE TO 15-20 KTS...BEFORE SLOWLY EASING
WEDNESDAY TO 10-15 KTS. THE ELEVATED WINDS WILL DRIVE SEAS UPWARD
WITH A STRONG NE WIND WAVE CONTRIBUTION TO THE SPECTRUM. SEAS OF
2-3 FT MONDAY WILL RISE QUICKLY TO 4-5 FT TUESDAY BEFORE FALLING
OFF TO 3-4 FT ON WEDNESDAY. THE COMBINATION OF WINDS AND SEAS MAY
REQUIRE A SCEC DURING MUCH OF TUESDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...DCH/TRA
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
945 PM CDT SUN SEP 15 2013
.UPDATE...
ISSUED AT 945 PM CDT SUN SEP 15 2013
DEWPOINT VALUES AROUND THE REGION ARE IN THE UPPER 30S OR LOW 40S.
IDEAL RADIATIONAL COOLING CONDITIONS ARE PRESENT...BUT DO NOT
EXPECT WIDESPREAD FROST GIVEN CURRENT DEW POINT VALUES. DID DROP
MIN TEMPS TO AROUND 33F FOR A FEW LOCATIONS THAT USUALLY BOTTOM
OUT (LANGDON...PORTIONS OF LAKE OF THE WOODS AND BELTRAMI
COUNTIES) AND ARE FALLING A BIT FASTER THAN EXPECTED. ALSO...EXPANDED
THE PATCHY FROST MENTION TO THE NORTHERN RED RIVER VALLEY.
OTHERWISE...THE GENERAL IDEA REMAINS THE SAME. ALTHOUGH PATCHY
FROST IS LIKELY...DO NOT EXPECT THE WIDESPREAD FROST NEEDED FOR AN
ADVISORY. WILL ALSO HAVE TO MONITOR THE POTENTIAL FOR FOG ACROSS
THE SOUTHERN FA WHERE RAIN FELL YESTERDAY...ALTHOUGH THE RAP AND
HRRR DO NOT INDICATE ANY FOG POTENTIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 322 PM CDT SUN SEP 15 2013
CLOUDS IN SOUTHEASTERN FCST AREA CLEARING OUT AND EXPECT A CLEAR
SKY TONIGHT AS HIGH PRESSURE MOVES FROM NORTH OF KENORA SOUTHEAST
TOWARD THE MN ARROWHEAD AND NW WISCONSIN BY 12Z MON. TRACK OF HIGH
AND LOWEST DEW PTS LOOK TO GO OVER MN ARROWHEAD JUST EAST OF OUR
FCST AREA AND WOULD EXPECT BEST CHANCES FOR WIDESPREAD 30-35 IN
KOOCH-ITASCA COUNTY EASTWARD. SOME THOUGHTS ON FROST ADVISORY FOR
SOME COUNTIES IN NW MN...BUT WITH CENTER OF HIGH A TAD EAST THINK
LOW TEMPS AROUND 34-35 WILL BE MORE ISOLATED TO THE TYPICAL COLD
SPOTS-LOW LYING AREAS-FORESTED FIRE WEATHER STATIONS. GENERALLY
FOR MOST PLACES OVER NRN VALLEY INTO NW MN EXPECT 37-38-39. DID
INCLUDE PATCHY FROST IN NW MN BUT LET EVE SHIFT MONITOR TEMP TRENDS.
SUNNY ON MONDAY AND A BIT WARMER AS WINDS TURN SOUTHEAST-SOUTHERLY
BUT REMAIN LIGHT. CLEAR MON NIGHT BUT WITH MILDER LOWS IN THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 322 PM CDT SUN SEP 15 2013
TUESDAY WILL SEE SOUTHERLY WINDS PICK UP AS PRESSURE GRADIENT
TIGHTENS BETWEEN DEPARTING HIGH AND SFC LOW IN CENTRAL SASK. IT
WILL BE WARMER AS WELL WITH HIGH UPPER 60S EAST TO MID 70S WEST.
MODELS CONTINUE TO ADVERTISE A SURGE OF MOISTURE AND SOME PRECIP
CHANCES NORTH-NORTHEAST INTO CENTRAL AND EASTERN MN TUES
OVERNIGHT-WED AND WILL MAINTAIN LOW POPS IN OUR EAST (BDE-BJI-
ADC)...THOUGH MAIN RISK OF PRECIP JUST EAST OF OUR REGION.
500 MB SHORT WAVE WILL MOVE NORTHEAST IN SOUTHWEST FLOW ALOFT WITH
SFC LOW DEVELOPING IN ERN MT INTO SE SASK WEDNESDAY. ENOUGH
MOISTURE FEED AND INSTABILITY BY AFTN FOR SOME THUNDER CHANCES IN
DVL REGION WED AFTN WITH GFS/GEM SHOWWALTERS DROPPING BELOW ZERO.
CHANCE OF SHOWERS AND THUNDERSTORMS WILL SPREAD EAST THRU THE AREA
WEDNESDAY AS SFC LOW MOVES INTO MANITOBA AND 500 MB LOW WITH
SYSTEM STRENGTHENS...THOUGH GREATEST RISK IS NORTH OF THE BORDER.
THE WEDNESDAY NIGHT THROUGH SUNDAY PERIOD WILL BE DOMINATED BY A
BIG CLOSED 500MB LOW PRESSURE SYSTEM MOVING ACROSS THE NORTHERN
PLAINS THU INTO FRI. MODELS NOT IN THE BEST OF AGREEMENT IN
REGARDS TO PCPN PLACEMENT AND TIMING FOR THIS SYSTEM BUT THERE ARE
SOME TRENDS. THERE MAY BE SOME CONVECTION OUT AHEAD OF THE LOW WED
NIGHT WITH A DRY SLOT DEVELOPING ON THU. THEREFORE MOST OF THE
AREA MAY ACTUALLY SEE A BIT OF A BREAK ON THU AND POSSIBLY EVEN
INTO THU NIGHT BEFORE WRAPAROUND SHOWERS COME BACK INTO THE AREA
FRI. WILL KEEP SAT DRY WITH BRIEF RIDGING MOVING IN AND THE NEXT
CHANCE OF PCPN ARRIVES QUICKLY BY SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 648 PM CDT SUN SEP 15 2013
LIGHT WINDS TONIGHT ALONG WITH CLEAR SKY. THE CLEAR SKY WILL
CONTINUE INTO MONDAY...ALTHOUGH WINDS WILL INCREASE FROM THE
SOUTH.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...GODON/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
948 PM EDT SUN SEP 15 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION OVERNIGHT. AN AREA OF
HIGH PRESSURE WILL BEGIN TO WORK INTO THE AREA ON MONDAY AND WILL
REMAIN NEAR THE AREA THROUGH TUESDAY NIGHT. A WEAK DISTURBANCE
WILL MOVE INTO THE REGION ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SHOWER ACTIVITY CONTINUES TO PROGRESS SOUTH AND EAST ACROSS THE FA
ALONG A COLD FRONT THAT CURRENTLY STRETCHES FROM AROUND IND TO CLE.
MAIN CONCERN WILL BE IF THE RAIN HOLDS TOGETHER OVERNIGHT TO MAKE
IT TO THE SOUTHERN HALF OF THE FA. THE 00Z KILN SOUNDING CONFIRMS
A DRY LAYER IN THE LOW LEVELS...AND THERE IS UNCERTAINTY WHETHER
THIS WILL ALLOW FOR MUCH /IF ANY/ MEASURABLE PRECIPITATION ACROSS
THE SOUTH. THE LATEST RAP RUNS HAVE TRENDED DRY ACROSS THE
TRI-STATE...AND ALTHOUGH THE SHOWER ACTIVITY HAS BEEN LEANING THAT
WAY...DID NOT HAVE ENOUGH CONFIDENCE TO GO LESS THAN CHANCE POPS
THERE. REGARDLESS...PRECIPITATION WILL REMAIN LIGHT OVERNIGHT WITH
AROUND A TENTH OF AN INCH OR LESS EXPECTED. ONLY MADE MINOR
ADJUSTMENTS TO THE PREVIOUS LOW TEMP FORECAST FOR TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL BE JUST SOUTH OF THE FA AT THE BEGINNING OF
THE SHORT TERM TIME PERIOD WITH ONLY THE CHANCE FOR A FEW LIGHT
SHOWERS ACROSS FAR SOUTHERN PORTIONS OF THE FA. A FEW ADDITIONAL
LIGHT SHOWERS WILL BE POSSIBLE DURING THE MORNING HOURS TO AROUND
MID DAY ACROSS CENTRAL OHIO WITH H8 WINDS OFF OF THE LAKE.
PRECIPITATION WILL TAPER OFF ACROSS THE FA BY THE AFTERNOON HOURS.
DRY CONDITIONS WILL BE PRESENT FOR THE REMAINDER OF THE SHORT TERM
TIME PERIOD AS HIGH PRESSURE BUILDS INTO THE REGION.
ALTHOUGH CLOUD COVER MAY DECREASE SLIGHTLY DURING THE DAYTIME
MORNING HOURS ON MONDAY ADDITIONAL CLOUD COVER WILL DEVELOP FOR
THE AFTERNOON HOURS WITH CAA. CLOUD COVER WILL DECREASE DURING THE
EVENING HOURS ON MONDAY AND BE MOSTLY CLEAR FOR A LARGE PORTION OF
THE OVERNIGHT HOURS MONDAY NIGHT.
COOL NORTHERLY FLOW AND CLOUD COVER WILL LIMIT TEMPERATURES FROM
RISING TOO MUCH ON MONDAY. HIGH TEMPERATURES WILL GENERALLY BE IN
THE MIDDLE 60S TO LOW 70S. AS CLOUD COVER AND WINDS BEGIN TO
DECREASE MONDAY NIGHT TEMPERATURES WILL FALL INTO THE MIDDLE 40S
TO LOWER 50S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BE CENTERED OVER NEW ENGLAND AT THE BEGINNING OF
THE FORECAST PERIOD PROVIDING DRY AND BELOW NORMAL CONDITIONS FOR
TUESDAY. BY WEDNESDAY...THE REGION WILL BE ON THE BACK SIDE OF THE
HIGH AND A RETURN FLOW WILL BRING WARMING TEMPERATURES AND AN
INCREASE IN HUMIDITY. PRECIPITATION CHANCES WILL RETURN BY WEDNESDAY
WITH 20 POPS...AND WILL INCREASE ON THURSDAY AND FRIDAY AS A CDFNT
PUSHES OUT OF THE PLAINS AND INTO THE OHIO VALLEY. AFT THE 00Z ECMWF
WAS A LITTLE QUICKER WITH THE FROPA FRIDAY...THE 12Z MODELS HAVE
COME INTO PRETTY GOOD AGREEMENT ON THE FRONTAL TIMING...PUSHING IT
THROUGH FRIDAY NIGHT. KEPT POPS FOR BOTH THURSDAY AND FRIDAY IN THE
CHANCE CATEGORY FOR NOW...BUT IF THE AGREEMENT CONTINUES INTO
TOMORROW...HIGHER POPS MIGHT BE WARRANTED. AS MENTIONED BEFORE THE
MODELS PUSH THE FRONT THROUGH THE REGION FRIDAY NIGHT. THE SOUTH AND
SOUTHEAST COULD SEE SOME LINGERING PCPN EARLY SATURDAY.
ANOTHER HIGH PRESSURE SYSTEM BUILDS DOWN FROM CANADA INTO THE GREAT
LAKES FOR SATURDAY NIGHT INTO SUNDAY.
TEMPERATURES WILL INCREASE FOR WEDNESDAY WITH HIGHS IN THE UPPER 70S
TO LOWER 80S. THURSDAY LOOKS LIKE THE WARMEST DAY OF THE WEEK WITH
HIGHS IN THE LOWER TO MID 80S...BEFORE CLOUDS AND PCPN DROP
TEMPERATURES BACK TO THE LOWER 80S ON FRIDAY. COOLER AIR WILL BUILD
IN NEXT WEEKEND. LOWS TUE NGT WILL BE IN THE 50S...BUT WILL WARM IN
THE 60S WED AND THU NIGHTS.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
SHOWERS WILL OCCUR ALONG AND BEHIND A COLD FRONT THAT WILL MOVE
ACROSS THE TERMINALS OVERNIGHT. PRECIPITATION COULD BRIEFLY REDUCE
VISIBILITY TO MVFR. THERE WILL BE A WIND SHIFT BUT WIND SPEEDS
WILL BE LIGHT ON EITHER SIDE OF THE BOUNDARY. AS COOLER AIR WORKS
IN CEILINGS ARE EXPECTED TO FALL BELOW 2000 FT BEFORE 12Z. MVFR
CEILINGS WILL PERSIST THROUGH THE MORNING WITH IMPROVEMENT IN
CONDITIONS LATE IN THE TAF PERIOD. NORTHERLY WINDS WILL INCREASE
TO AROUND 10 KT DURING THE DAY.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THURSDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...KURZ
SHORT TERM...NOVAK/SITES
LONG TERM...SITES
AVIATION...
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
115 PM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL BUILD TO THE MID-ATLANTIC ON SUNDAY. LOW
PRESSURE PASSING NORTH OF THE GREAT LAKES WILL PULL A COLD FRONT
SOUTH ACROSS THE AREA SUNDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST FOR THIS AFTERNOON IS GOOD.
ORIGINAL DISCUSSION...HIGH PRESSURE IS CENTERED OVER LAKE
MICHIGAN THIS MORNING WITH LIGHT NORTHERLY FLOW MAINTAINING A
STRATOCU DECK OFF OF LAKE ERIE ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. THE RUC HAS BEEN DOING A GOOD JOB OVERNIGHT WITH
THE DEPICTION OF 850MB MOISTURE WHICH SEEMS TO BE A GOOD PROXY FOR
THE CLEARING TREND APPROACHING FROM THE NORTH. A VERY DRY AIRMASS
IS IN PLACE ACROSS THE UPPER GREAT LAKES AND EXPECT THIS TO SETTLE
SOUTH ACROSS LAKE ERIE THIS MORNING AND BRING AN END TO THE LAKE
EFFECT CLOUDS. SOME DIURNAL ENHANCEMENT TO THE CU FIELD WILL OCCUR
THIS MORNING WITH SKIES RANGING FROM MOSTLY SUNNY IN EXTREME NW
OHIO TO MOSTLY CLOUDY IN NW PA. CLOUDS WILL CLEAR FROM NORTH TO
SOUTH THROUGH THE AFTERNOON AS SUBSIDENCE INCREASES WITH VERY DRY
AIR ALOFT. TEMPERATURES WILL WARM 3 TO 5 DEGREES FROM YESTERDAYS
HIGHS AT MOST LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL START OFF OVERHEAD THIS EVENING...BUILDING TO
PENNSYLVANIA OVERNIGHT. CLEAR SKIES...LIGHT WINDS AND SUBSIDENCE
WILL BE A GOOD RECIPE FOR ANOTHER COLD NIGHT ACROSS THE EASTERN HALF
OF THE AREA. OVERNIGHT TEMPERATURES WILL FOLLOW THE DEWPOINTS DOWN
WITH MINS RANGING FROM THE MID 40S WEST TO UPPER 30S EAST. PATCHY
FROST MAY BE POSSIBLE IN SOME OF THE TYPICALLY COOLER LOCATIONS IN
NW PA OVERNIGHT BUT EXPECTING THE COVERAGE TO BE PRETTY ISOLATED SO
LEFT OUT OF THE FORECAST.
LOW PRESSURE NEAR HUDSON BAY WILL TRACK INTO QUEBEC ON SUNDAY WITH A
TRAILING COLD FRONT PUSHING SOUTH ACROSS THE AREA ON SUNDAY NIGHT.
MID AND HIGH CLOUDS WILL OVERSPREAD THE AREA AND THICKEN DURING THE
DAY ON SUNDAY AHEAD OF THE UPPER LEVEL TROUGH DROPPING SOUTH OUT OF
CANADA. KNOCKED TEMPERATURES DOWN A DEGREE OR TWO IN THE WEST ON
SUNDAY IN FAVOR OF MORE CLOUDS. VERY DRY AIR WILL BE SLOW TO
OVERCOME IN THE LOW LEVELS AND EXPECT ONLY SOME SPRINKLES OR AN
ISOLATED SHOWER IN NW OHIO DURING THE LATE AFTERNOON. SCATTERED
SHOWERS WILL OVERSPREAD THE AREA SUNDAY EVENING AS THE FRONT
PUSHES SOUTH TOWARDS THE HIGHER MOISTURE. NOT MUCH INSTABILITY
ACCOMPANYING THIS SYSTEM SO WILL LEAVE THUNDER OUT OF THE
FORECAST. DRY AIR AND NEGATIVE THETA-E ADVECTION ALREADY ARRIVING
BY LATE SUNDAY NIGHT SO SHOWERS SHOULD COME TO A QUICK END EXCEPT
IN THE SNOW BELT WHERE WE WILL SEE SOME LAKE EFFECT SHOWERS
DEVELOP AND LINGER INTO MONDAY MORNING. TEMPERATURES ON MONDAY
WILL BE BACK DOWN IN THE LOW AND MID 60S AGAIN.
STRONG HIGH PRESSURE AND VERY DRY AIR WILL BUILD IN BEHIND THIS NEXT
FRONT AGAIN FOR MONDAY AFTERNOON AND TUESDAY. EXPECTING LOW LEVELS
TO DRY OUT ENOUGH BY MONDAY AFTERNOON FOR THE LAKE EFFECT SHOWERS
TO BE WINDING DOWN. TEMPERATURES ONCE AGAIN DROP INTO THE LOW 40S
ON MONDAY NIGHT...ISOLATED LOCALS INTO THE UPPER 30S IN NW PA.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
DRY WEDNESDAY AND THEN A CHANCE OF SHOWERS AND THUNDERSTORMS RETURN
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. FOR WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT THE THREAT OF PRECIPITATION IS BECAUSE OF
SHORT WAVES IN THE WESTERLY FLOW ALOFT ALONG WITH ADEQUATE MOISTURE.
WEDNESDAY NIGHT SHOULD BE STABLE ENOUGH FOR JUST SHOWERS. A COLD
FRONT WILL MOVE THROUGH FRIDAY AFTERNOON AND EVENING. THE MODELS ARE
IN GENERAL AGREEMENT DURING THIS PERIOD. JUST MADE SOME MINOR
CHANGES TO THE POPS. FOR THE TIME BEING KEPT THE POPS EITHER 30 OR
40 PERCENT. THAT SEEMS REAL GOOD FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT BASED ON THE AMOUNT OF MOISTURE ALOFT. FOR FRIDAY
WHEN THE MOISTURE SEEMS TO GET BETTER AHEAD OF THE FRONT THE POPS
MAY NEED TO BE RAISED IF THE TIMING AND TREND CONTINUES. KEPT CLOSE
TO HPC GUIDANCE FOR THE TEMPERATURE FORECAST WHICH IS A LITTLE ABOVE
NORMAL.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
QUIET WEATHER WILL CONTINUE DURING THE PERIOD WITH JUST A FEW CU
THIS AFTERNOON. WILL SEE A GRADUAL INCREASE IN HIGH CLOUDS THE
SECOND HALF OF THE PERIOD. LIGHT AND VARIABLE FLOW WILL BECOME
SOUTHERLY ON SUNDAY MORNING.
OUTLOOK...AREAS OF NON VFR POSSIBLE MAINLY SUN NIGHT.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE LAKE TODAY. THE BIG
QUESTION IS WILL THE SMALL CRAFT ADVISORY HAVE TO BE EXTENDED FOR A
FEW MORE HOURS. THE TREND FOR THE WINDS AND WAVES IS DEFINITELY
DOWN. BASED ON THE 3 AM MARINE OBSERVATIONS WILL LET THE SMALL CRAFT
ADVISORY EXPIRE. THE NEARSHORE FORECAST WILL HAVE 2 TO 4 FEET TO
START AND THEN SUBSIDING AS THE MORNING AND DAY GOES ON. THE RIP
CURRENT RISK IS CLOSE TO MODERATE MAINLY EARLY THIS MORNING BUT THE
RISK WILL DECREASE QUICKLY TODAY.
THE HIGH WILL MOVE EAST OF THE LAKE BY SUNDAY MORNING RETURNING A
SOUTHWEST FLOW. A FRONT WILL MOVE ACROSS THE LAKE LATE SUNDAY
SHIFTING THE WINDS TO ONSHORE. AT THIS TIME IT LOOKS LIKE THEY WILL
BE LIGHT ENOUGH NOT TO NEED A SMALL CRAFT ADVISORY. HIGH PRESSURE
WILL MOVE JUST TO THE NORTH OF LAKE ERIE MONDAY INTO TUESDAY. A
SOUTH TO SOUTHWEST FLOW WILL RETURN FOR WEDNESDAY AND THURSDAY. AT
THIS TIME IT DOESN`T LOOK LIKE CONDITIONS WILL MEET SMALL CRAFT
ADVISORY CRITERIA.
A COLD FRONT WILL MOVE ACROSS THE LAKE LATE FRIDAY. A SMALL CRAFT
ADVISORY MAY BE NEEDED MAINLY AFTER THE FRONTAL PASSAGE AND SPECIAL
MARINE WARNINGS MAY BE ISSUED FOR THUNDERSTORMS AHEAD OF THE
FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/OUDEMAN
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KUBINA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1212 PM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL BUILD TO THE MID-ATLANTIC ON SUNDAY. LOW
PRESSURE PASSING NORTH OF THE GREAT LAKES WILL PULL A COLD FRONT
SOUTH ACROSS THE AREA SUNDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST FOR THIS AFTERNOON IS GOOD.
ORIGINAL DISCUSSION...HIGH PRESSURE IS CENTERED OVER LAKE
MICHIGAN THIS MORNING WITH LIGHT NORTHERLY FLOW MAINTAINING A
STRATOCU DECK OFF OF LAKE ERIE ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. THE RUC HAS BEEN DOING A GOOD JOB OVERNIGHT WITH
THE DEPICTION OF 850MB MOISTURE WHICH SEEMS TO BE A GOOD PROXY FOR
THE CLEARING TREND APPROACHING FROM THE NORTH. A VERY DRY AIRMASS
IS IN PLACE ACROSS THE UPPER GREAT LAKES AND EXPECT THIS TO SETTLE
SOUTH ACROSS LAKE ERIE THIS MORNING AND BRING AN END TO THE LAKE
EFFECT CLOUDS. SOME DIURNAL ENHANCEMENT TO THE CU FIELD WILL OCCUR
THIS MORNING WITH SKIES RANGING FROM MOSTLY SUNNY IN EXTREME NW
OHIO TO MOSTLY CLOUDY IN NW PA. CLOUDS WILL CLEAR FROM NORTH TO
SOUTH THROUGH THE AFTERNOON AS SUBSIDENCE INCREASES WITH VERY DRY
AIR ALOFT. TEMPERATURES WILL WARM 3 TO 5 DEGREES FROM YESTERDAYS
HIGHS AT MOST LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL START OFF OVERHEAD THIS EVENING...BUILDING TO
PENNSYLVANIA OVERNIGHT. CLEAR SKIES...LIGHT WINDS AND SUBSIDENCE
WILL BE A GOOD RECIPE FOR ANOTHER COLD NIGHT ACROSS THE EASTERN HALF
OF THE AREA. OVERNIGHT TEMPERATURES WILL FOLLOW THE DEWPOINTS DOWN
WITH MINS RANGING FROM THE MID 40S WEST TO UPPER 30S EAST. PATCHY
FROST MAY BE POSSIBLE IN SOME OF THE TYPICALLY COOLER LOCATIONS IN
NW PA OVERNIGHT BUT EXPECTING THE COVERAGE TO BE PRETTY ISOLATED SO
LEFT OUT OF THE FORECAST.
LOW PRESSURE NEAR HUDSON BAY WILL TRACK INTO QUEBEC ON SUNDAY WITH A
TRAILING COLD FRONT PUSHING SOUTH ACROSS THE AREA ON SUNDAY NIGHT.
MID AND HIGH CLOUDS WILL OVERSPREAD THE AREA AND THICKEN DURING THE
DAY ON SUNDAY AHEAD OF THE UPPER LEVEL TROUGH DROPPING SOUTH OUT OF
CANADA. KNOCKED TEMPERATURES DOWN A DEGREE OR TWO IN THE WEST ON
SUNDAY IN FAVOR OF MORE CLOUDS. VERY DRY AIR WILL BE SLOW TO
OVERCOME IN THE LOW LEVELS AND EXPECT ONLY SOME SPRINKLES OR AN
ISOLATED SHOWER IN NW OHIO DURING THE LATE AFTERNOON. SCATTERED
SHOWERS WILL OVERSPREAD THE AREA SUNDAY EVENING AS THE FRONT
PUSHES SOUTH TOWARDS THE HIGHER MOISTURE. NOT MUCH INSTABILITY
ACCOMPANYING THIS SYSTEM SO WILL LEAVE THUNDER OUT OF THE
FORECAST. DRY AIR AND NEGATIVE THETA-E ADVECTION ALREADY ARRIVING
BY LATE SUNDAY NIGHT SO SHOWERS SHOULD COME TO A QUICK END EXCEPT
IN THE SNOW BELT WHERE WE WILL SEE SOME LAKE EFFECT SHOWERS
DEVELOP AND LINGER INTO MONDAY MORNING. TEMPERATURES ON MONDAY
WILL BE BACK DOWN IN THE LOW AND MID 60S AGAIN.
STRONG HIGH PRESSURE AND VERY DRY AIR WILL BUILD IN BEHIND THIS NEXT
FRONT AGAIN FOR MONDAY AFTERNOON AND TUESDAY. EXPECTING LOW LEVELS
TO DRY OUT ENOUGH BY MONDAY AFTERNOON FOR THE LAKE EFFECT SHOWERS
TO BE WINDING DOWN. TEMPERATURES ONCE AGAIN DROP INTO THE LOW 40S
ON MONDAY NIGHT...ISOLATED LOCALS INTO THE UPPER 30S IN NW PA.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
DRY WEDNESDAY AND THEN A CHANCE OF SHOWERS AND THUNDERSTORMS RETURN
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. FOR WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT THE THREAT OF PRECIPITATION IS BECAUSE OF
SHORT WAVES IN THE WESTERLY FLOW ALOFT ALONG WITH ADEQUATE MOISTURE.
WEDNESDAY NIGHT SHOULD BE STABLE ENOUGH FOR JUST SHOWERS. A COLD
FRONT WILL MOVE THROUGH FRIDAY AFTERNOON AND EVENING. THE MODELS ARE
IN GENERAL AGREEMENT DURING THIS PERIOD. JUST MADE SOME MINOR
CHANGES TO THE POPS. FOR THE TIME BEING KEPT THE POPS EITHER 30 OR
40 PERCENT. THAT SEEMS REAL GOOD FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT BASED ON THE AMOUNT OF MOISTURE ALOFT. FOR FRIDAY
WHEN THE MOISTURE SEEMS TO GET BETTER AHEAD OF THE FRONT THE POPS
MAY NEED TO BE RAISED IF THE TIMING AND TREND CONTINUES. KEPT CLOSE
TO HPC GUIDANCE FOR THE TEMPERATURE FORECAST WHICH IS A LITTLE ABOVE
NORMAL.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE
TAF PERIOD. THE FLOW WILL REMAIN NORTHERLY INTO THE AFTERNOON
BEFORE WEAKENING. THE QUESTION IS HOW QUICKLY WILL THE CLOUDS GO
AWAY OVER NE OH AND NW PA. THE LAKE AND 850 MB TEMPERATURE
DIFFERENCE IS NEAR 18C TO START AND BY MID AFTERNOON WILL BE DOWN
TO AROUND 15C. THIS DIFFERENCE IS ENOUGH TO KEEP SOME CLOUDS
GOING. HOWEVER WITH PLENTY OF SUBSIDENCE THAT WILL EVENTUALLY WIN
OUT...BUT THE QUESTION IS HOW SOON WILL THAT HAPPEN. BASED ON THE
SATELLITE PICTURES AND USING THE RAP MODEL WILL SCATTER THE CLOUDS
OUT BY NOON. SOME HEATING THIS MORNING MAY BRIEFLY INCREASE THE
CLOUDS. NONE THE LESS IT IS VFR. NORTHWEST OHIO SHOULD REMAIN
MOSTLY CLEAR TODAY.
AS THE FLOW BECOMES OFFSHORE LATE THIS AFTERNOON AND EVENING THE
CLOUDS WILL GO AWAY. SOME CIRRUS FROM THE NEXT SYSTEM WILL START
COMING IN TONIGHT. THE AIRMASS SHOULD BE DRY ENOUGH FOR NO FOG AT
THE TAF SITES...OTHERWISE ISOLATED MVFR BR AT FAVORED LOCATIONS.
OUTLOOK...AREAS OF NON VFR POSSIBLE MAINLY SUN NIGHT.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE LAKE TODAY. THE BIG
QUESTION IS WILL THE SMALL CRAFT ADVISORY HAVE TO BE EXTENDED FOR A
FEW MORE HOURS. THE TREND FOR THE WINDS AND WAVES IS DEFINITELY
DOWN. BASED ON THE 3 AM MARINE OBSERVATIONS WILL LET THE SMALL CRAFT
ADVISORY EXPIRE. THE NEARSHORE FORECAST WILL HAVE 2 TO 4 FEET TO
START AND THEN SUBSIDING AS THE MORNING AND DAY GOES ON. THE RIP
CURRENT RISK IS CLOSE TO MODERATE MAINLY EARLY THIS MORNING BUT THE
RISK WILL DECREASE QUICKLY TODAY.
THE HIGH WILL MOVE EAST OF THE LAKE BY SUNDAY MORNING RETURNING A
SOUTHWEST FLOW. A FRONT WILL MOVE ACROSS THE LAKE LATE SUNDAY
SHIFTING THE WINDS TO ONSHORE. AT THIS TIME IT LOOKS LIKE THEY WILL
BE LIGHT ENOUGH NOT TO NEED A SMALL CRAFT ADVISORY. HIGH PRESSURE
WILL MOVE JUST TO THE NORTH OF LAKE ERIE MONDAY INTO TUESDAY. A
SOUTH TO SOUTHWEST FLOW WILL RETURN FOR WEDNESDAY AND THURSDAY. AT
THIS TIME IT DOESN`T LOOK LIKE CONDITIONS WILL MEET SMALL CRAFT
ADVISORY CRITERIA.
A COLD FRONT WILL MOVE ACROSS THE LAKE LATE FRIDAY. A SMALL CRAFT
ADVISORY MAY BE NEEDED MAINLY AFTER THE FRONTAL PASSAGE AND SPECIAL
MARINE WARNINGS MAY BE ISSUED FOR THUNDERSTORMS AHEAD OF THE
FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/OUDEMAN
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
929 AM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL BUILD TO THE MID-ATLANTIC ON SUNDAY. LOW
PRESSURE PASSING NORTH OF THE GREAT LAKES WILL PULL A COLD FRONT
SOUTH ACROSS THE AREA SUNDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE ADJUSTED SKY COVER FOR THE QUICKER CLEARING THIS MORNING. MAY
STILL HAVE A FEW AFTERNOON CU DOTTING THE SKY...BUT NOT MUCH.
ADJUSTED HOURLY TEMPERATURES...BUT OVERALL HIGH FOR THE DAY STILL
APPEARS ON TRACK.
ORIGINAL DISCUSSION...HIGH PRESSURE IS CENTERED OVER LAKE
MICHIGAN THIS MORNING WITH LIGHT NORTHERLY FLOW MAINTAINING A
STRATOCU DECK OFF OF LAKE ERIE ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. THE RUC HAS BEEN DOING A GOOD JOB OVERNIGHT WITH
THE DEPICTION OF 850MB MOISTURE WHICH SEEMS TO BE A GOOD PROXY FOR
THE CLEARING TREND APPROACHING FROM THE NORTH. A VERY DRY AIRMASS
IS IN PLACE ACROSS THE UPPER GREAT LAKES AND EXPECT THIS TO SETTLE
SOUTH ACROSS LAKE ERIE THIS MORNING AND BRING AN END TO THE LAKE
EFFECT CLOUDS. SOME DIURNAL ENHANCEMENT TO THE CU FIELD WILL OCCUR
THIS MORNING WITH SKIES RANGING FROM MOSTLY SUNNY IN EXTREME NW
OHIO TO MOSTLY CLOUDY IN NW PA. CLOUDS WILL CLEAR FROM NORTH TO
SOUTH THROUGH THE AFTERNOON AS SUBSIDENCE INCREASES WITH VERY DRY
AIR ALOFT. TEMPERATURES WILL WARM 3 TO 5 DEGREES FROM YESTERDAYS
HIGHS AT MOST LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL START OFF OVERHEAD THIS EVENING...BUILDING TO
PENNSYLVANIA OVERNIGHT. CLEAR SKIES...LIGHT WINDS AND SUBSIDENCE
WILL BE A GOOD RECIPE FOR ANOTHER COLD NIGHT ACROSS THE EASTERN HALF
OF THE AREA. OVERNIGHT TEMPERATURES WILL FOLLOW THE DEWPOINTS DOWN
WITH MINS RANGING FROM THE MID 40S WEST TO UPPER 30S EAST. PATCHY
FROST MAY BE POSSIBLE IN SOME OF THE TYPICALLY COOLER LOCATIONS IN
NW PA OVERNIGHT BUT EXPECTING THE COVERAGE TO BE PRETTY ISOLATED SO
LEFT OUT OF THE FORECAST.
LOW PRESSURE NEAR HUDSON BAY WILL TRACK INTO QUEBEC ON SUNDAY WITH A
TRAILING COLD FRONT PUSHING SOUTH ACROSS THE AREA ON SUNDAY NIGHT.
MID AND HIGH CLOUDS WILL OVERSPREAD THE AREA AND THICKEN DURING THE
DAY ON SUNDAY AHEAD OF THE UPPER LEVEL TROUGH DROPPING SOUTH OUT OF
CANADA. KNOCKED TEMPERATURES DOWN A DEGREE OR TWO IN THE WEST ON
SUNDAY IN FAVOR OF MORE CLOUDS. VERY DRY AIR WILL BE SLOW TO
OVERCOME IN THE LOW LEVELS AND EXPECT ONLY SOME SPRINKLES OR AN
ISOLATED SHOWER IN NW OHIO DURING THE LATE AFTERNOON. SCATTERED
SHOWERS WILL OVERSPREAD THE AREA SUNDAY EVENING AS THE FRONT
PUSHES SOUTH TOWARDS THE HIGHER MOISTURE. NOT MUCH INSTABILITY
ACCOMPANYING THIS SYSTEM SO WILL LEAVE THUNDER OUT OF THE
FORECAST. DRY AIR AND NEGATIVE THETA-E ADVECTION ALREADY ARRIVING
BY LATE SUNDAY NIGHT SO SHOWERS SHOULD COME TO A QUICK END EXCEPT
IN THE SNOW BELT WHERE WE WILL SEE SOME LAKE EFFECT SHOWERS
DEVELOP AND LINGER INTO MONDAY MORNING. TEMPERATURES ON MONDAY
WILL BE BACK DOWN IN THE LOW AND MID 60S AGAIN.
STRONG HIGH PRESSURE AND VERY DRY AIR WILL BUILD IN BEHIND THIS NEXT
FRONT AGAIN FOR MONDAY AFTERNOON AND TUESDAY. EXPECTING LOW LEVELS
TO DRY OUT ENOUGH BY MONDAY AFTERNOON FOR THE LAKE EFFECT SHOWERS
TO BE WINDING DOWN. TEMPERATURES ONCE AGAIN DROP INTO THE LOW 40S
ON MONDAY NIGHT...ISOLATED LOCALS INTO THE UPPER 30S IN NW PA.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
DRY WEDNESDAY AND THEN A CHANCE OF SHOWERS AND THUNDERSTORMS RETURN
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. FOR WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT THE THREAT OF PRECIPITATION IS BECAUSE OF
SHORT WAVES IN THE WESTERLY FLOW ALOFT ALONG WITH ADEQUATE MOISTURE.
WEDNESDAY NIGHT SHOULD BE STABLE ENOUGH FOR JUST SHOWERS. A COLD
FRONT WILL MOVE THROUGH FRIDAY AFTERNOON AND EVENING. THE MODELS ARE
IN GENERAL AGREEMENT DURING THIS PERIOD. JUST MADE SOME MINOR
CHANGES TO THE POPS. FOR THE TIME BEING KEPT THE POPS EITHER 30 OR
40 PERCENT. THAT SEEMS REAL GOOD FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT BASED ON THE AMOUNT OF MOISTURE ALOFT. FOR FRIDAY
WHEN THE MOISTURE SEEMS TO GET BETTER AHEAD OF THE FRONT THE POPS
MAY NEED TO BE RAISED IF THE TIMING AND TREND CONTINUES. KEPT CLOSE
TO HPC GUIDANCE FOR THE TEMPERATURE FORECAST WHICH IS A LITTLE ABOVE
NORMAL.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE
TAF PERIOD. THE FLOW WILL REMAIN NORTHERLY INTO THE AFTERNOON
BEFORE WEAKENING. THE QUESTION IS HOW QUICKLY WILL THE CLOUDS GO
AWAY OVER NE OH AND NW PA. THE LAKE AND 850 MB TEMPERATURE
DIFFERENCE IS NEAR 18C TO START AND BY MID AFTERNOON WILL BE DOWN
TO AROUND 15C. THIS DIFFERENCE IS ENOUGH TO KEEP SOME CLOUDS
GOING. HOWEVER WITH PLENTY OF SUBSIDENCE THAT WILL EVENTUALLY WIN
OUT...BUT THE QUESTION IS HOW SOON WILL THAT HAPPEN. BASED ON THE
SATELLITE PICTURES AND USING THE RAP MODEL WILL SCATTER THE CLOUDS
OUT BY NOON. SOME HEATING THIS MORNING MAY BRIEFLY INCREASE THE
CLOUDS. NONE THE LESS IT IS VFR. NORTHWEST OHIO SHOULD REMAIN
MOSTLY CLEAR TODAY.
AS THE FLOW BECOMES OFFSHORE LATE THIS AFTERNOON AND EVENING THE
CLOUDS WILL GO AWAY. SOME CIRRUS FROM THE NEXT SYSTEM WILL START
COMING IN TONIGHT. THE AIRMASS SHOULD BE DRY ENOUGH FOR NO FOG AT
THE TAF SITES...OTHERWISE ISOLATED MVFR BR AT FAVORED LOCATIONS.
OUTLOOK...AREAS OF NON VFR POSSIBLE MAINLY SUN NIGHT.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE LAKE TODAY. THE BIG
QUESTION IS WILL THE SMALL CRAFT ADVISORY HAVE TO BE EXTENDED FOR A
FEW MORE HOURS. THE TREND FOR THE WINDS AND WAVES IS DEFINITELY
DOWN. BASED ON THE 3 AM MARINE OBSERVATIONS WILL LET THE SMALL CRAFT
ADVISORY EXPIRE. THE NEARSHORE FORECAST WILL HAVE 2 TO 4 FEET TO
START AND THEN SUBSIDING AS THE MORNING AND DAY GOES ON. THE RIP
CURRENT RISK IS CLOSE TO MODERATE MAINLY EARLY THIS MORNING BUT THE
RISK WILL DECREASE QUICKLY TODAY.
THE HIGH WILL MOVE EAST OF THE LAKE BY SUNDAY MORNING RETURNING A
SOUTHWEST FLOW. A FRONT WILL MOVE ACROSS THE LAKE LATE SUNDAY
SHIFTING THE WINDS TO ONSHORE. AT THIS TIME IT LOOKS LIKE THEY WILL
BE LIGHT ENOUGH NOT TO NEED A SMALL CRAFT ADVISORY. HIGH PRESSURE
WILL MOVE JUST TO THE NORTH OF LAKE ERIE MONDAY INTO TUESDAY. A
SOUTH TO SOUTHWEST FLOW WILL RETURN FOR WEDNESDAY AND THURSDAY. AT
THIS TIME IT DOESN`T LOOK LIKE CONDITIONS WILL MEET SMALL CRAFT
ADVISORY CRITERIA.
A COLD FRONT WILL MOVE ACROSS THE LAKE LATE FRIDAY. A SMALL CRAFT
ADVISORY MAY BE NEEDED MAINLY AFTER THE FRONTAL PASSAGE AND SPECIAL
MARINE WARNINGS MAY BE ISSUED FOR THUNDERSTORMS AHEAD OF THE
FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/OUDEMAN
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
737 AM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL BUILD TO THE MID-ATLANTIC ON SUNDAY. LOW
PRESSURE PASSING NORTH OF THE GREAT LAKES WILL PULL A COLD FRONT
SOUTH ACROSS THE AREA SUNDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SATELLITE IMAGERY SHOWS CLEARING TREND CONTINUING TO PUSH
SOUTH...NEARING THE SOUTHERN SHORE OF LAKE ERIE AT 7 AM. STILL
EXPECTING CLOUDS TO BREAK AWAY FROM THE LAKE AND PUSH INLAND THIS
MORNING WITH SOME DIURNAL ENHANCEMENT...THEN CLEARING THIS
AFTERNOON. GOING FORECAST REMAINS ON TRACK.
ORIGINAL DISCUSSION...HIGH PRESSURE IS CENTERED OVER LAKE
MICHIGAN THIS MORNING WITH LIGHT NORTHERLY FLOW MAINTAINING A
STRATOCU DECK OFF OF LAKE ERIE ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. THE RUC HAS BEEN DOING A GOOD JOB OVERNIGHT WITH
THE DEPICTION OF 850MB MOISTURE WHICH SEEMS TO BE A GOOD PROXY FOR
THE CLEARING TREND APPROACHING FROM THE NORTH. A VERY DRY AIRMASS
IS IN PLACE ACROSS THE UPPER GREAT LAKES AND EXPECT THIS TO SETTLE
SOUTH ACROSS LAKE ERIE THIS MORNING AND BRING AN END TO THE LAKE
EFFECT CLOUDS. SOME DIURNAL ENHANCEMENT TO THE CU FIELD WILL OCCUR
THIS MORNING WITH SKIES RANGING FROM MOSTLY SUNNY IN EXTREME NW
OHIO TO MOSTLY CLOUDY IN NW PA. CLOUDS WILL CLEAR FROM NORTH TO
SOUTH THROUGH THE AFTERNOON AS SUBSIDENCE INCREASES WITH VERY DRY
AIR ALOFT. TEMPERATURES WILL WARM 3 TO 5 DEGREES FROM YESTERDAYS
HIGHS AT MOST LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL START OFF OVERHEAD THIS EVENING...BUILDING TO
PENNSYLVANIA OVERNIGHT. CLEAR SKIES...LIGHT WINDS AND SUBSIDENCE
WILL BE A GOOD RECIPE FOR ANOTHER COLD NIGHT ACROSS THE EASTERN HALF
OF THE AREA. OVERNIGHT TEMPERATURES WILL FOLLOW THE DEWPOINTS DOWN
WITH MINS RANGING FROM THE MID 40S WEST TO UPPER 30S EAST. PATCHY
FROST MAY BE POSSIBLE IN SOME OF THE TYPICALLY COOLER LOCATIONS IN
NW PA OVERNIGHT BUT EXPECTING THE COVERAGE TO BE PRETTY ISOLATED SO
LEFT OUT OF THE FORECAST.
LOW PRESSURE NEAR HUDSON BAY WILL TRACK INTO QUEBEC ON SUNDAY WITH A
TRAILING COLD FRONT PUSHING SOUTH ACROSS THE AREA ON SUNDAY NIGHT.
MID AND HIGH CLOUDS WILL OVERSPREAD THE AREA AND THICKEN DURING THE
DAY ON SUNDAY AHEAD OF THE UPPER LEVEL TROUGH DROPPING SOUTH OUT OF
CANADA. KNOCKED TEMPERATURES DOWN A DEGREE OR TWO IN THE WEST ON
SUNDAY IN FAVOR OF MORE CLOUDS. VERY DRY AIR WILL BE SLOW TO
OVERCOME IN THE LOW LEVELS AND EXPECT ONLY SOME SPRINKLES OR AN
ISOLATED SHOWER IN NW OHIO DURING THE LATE AFTERNOON. SCATTERED
SHOWERS WILL OVERSPREAD THE AREA SUNDAY EVENING AS THE FRONT
PUSHES SOUTH TOWARDS THE HIGHER MOISTURE. NOT MUCH INSTABILITY
ACCOMPANYING THIS SYSTEM SO WILL LEAVE THUNDER OUT OF THE
FORECAST. DRY AIR AND NEGATIVE THETA-E ADVECTION ALREADY ARRIVING
BY LATE SUNDAY NIGHT SO SHOWERS SHOULD COME TO A QUICK END EXCEPT
IN THE SNOW BELT WHERE WE WILL SEE SOME LAKE EFFECT SHOWERS
DEVELOP AND LINGER INTO MONDAY MORNING. TEMPERATURES ON MONDAY
WILL BE BACK DOWN IN THE LOW AND MID 60S AGAIN.
STRONG HIGH PRESSURE AND VERY DRY AIR WILL BUILD IN BEHIND THIS NEXT
FRONT AGAIN FOR MONDAY AFTERNOON AND TUESDAY. EXPECTING LOW LEVELS
TO DRY OUT ENOUGH BY MONDAY AFTERNOON FOR THE LAKE EFFECT SHOWERS
TO BE WINDING DOWN. TEMPERATURES ONCE AGAIN DROP INTO THE LOW 40S
ON MONDAY NIGHT...ISOLATED LOCALS INTO THE UPPER 30S IN NW PA.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
DRY WEDNESDAY AND THEN A CHANCE OF SHOWERS AND THUNDERSTORMS RETURN
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. FOR WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT THE THREAT OF PRECIPITATION IS BECAUSE OF
SHORT WAVES IN THE WESTERLY FLOW ALOFT ALONG WITH ADEQUATE MOISTURE.
WEDNESDAY NIGHT SHOULD BE STABLE ENOUGH FOR JUST SHOWERS. A COLD
FRONT WILL MOVE THROUGH FRIDAY AFTERNOON AND EVENING. THE MODELS ARE
IN GENERAL AGREEMENT DURING THIS PERIOD. JUST MADE SOME MINOR
CHANGES TO THE POPS. FOR THE TIME BEING KEPT THE POPS EITHER 30 OR
40 PERCENT. THAT SEEMS REAL GOOD FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT BASED ON THE AMOUNT OF MOISTURE ALOFT. FOR FRIDAY
WHEN THE MOISTURE SEEMS TO GET BETTER AHEAD OF THE FRONT THE POPS
MAY NEED TO BE RAISED IF THE TIMING AND TREND CONTINUES. KEPT CLOSE
TO HPC GUIDANCE FOR THE TEMPERATURE FORECAST WHICH IS A LITTLE ABOVE
NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE
TAF PERIOD. THE FLOW WILL REMAIN NORTHERLY INTO THE AFTERNOON
BEFORE WEAKENING. THE QUESTION IS HOW QUICKLY WILL THE CLOUDS GO
AWAY OVER NE OH AND NW PA. THE LAKE AND 850 MB TEMPERATURE
DIFFERENCE IS NEAR 18C TO START AND BY MID AFTERNOON WILL BE DOWN
TO AROUND 15C. THIS DIFFERENCE IS ENOUGH TO KEEP SOME CLOUDS
GOING. HOWEVER WITH PLENTY OF SUBSIDENCE THAT WILL EVENTUALLY WIN
OUT...BUT THE QUESTION IS HOW SOON WILL THAT HAPPEN. BASED ON THE
SATELLITE PICTURES AND USING THE RAP MODEL WILL SCATTER THE CLOUDS
OUT BY NOON. SOME HEATING THIS MORNING MAY BRIEFLY INCREASE THE
CLOUDS. NONE THE LESS IT IS VFR. NORTHWEST OHIO SHOULD REMAIN
MOSTLY CLEAR TODAY.
AS THE FLOW BECOMES OFFSHORE LATE THIS AFTERNOON AND EVENING THE
CLOUDS WILL GO AWAY. SOME CIRRUS FROM THE NEXT SYSTEM WILL START
COMING IN TONIGHT. THE AIRMASS SHOULD BE DRY ENOUGH FOR NO FOG AT
THE TAF SITES...OTHERWISE ISOLATED MVFR BR AT FAVORED LOCATIONS.
OUTLOOK...AREAS OF NON VFR POSSIBLE MAINLY SUN NIGHT.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE LAKE TODAY. THE BIG
QUESTION IS WILL THE SMALL CRAFT ADVISORY HAVE TO BE EXTENDED FOR A
FEW MORE HOURS. THE TREND FOR THE WINDS AND WAVES IS DEFINITELY
DOWN. BASED ON THE 3 AM MARINE OBSERVATIONS WILL LET THE SMALL CRAFT
ADVISORY EXPIRE. THE NEARSHORE FORECAST WILL HAVE 2 TO 4 FEET TO
START AND THEN SUBSIDING AS THE MORNING AND DAY GOES ON. THE RIP
CURRENT RISK IS CLOSE TO MODERATE MAINLY EARLY THIS MORNING BUT THE
RISK WILL DECREASE QUICKLY TODAY.
THE HIGH WILL MOVE EAST OF THE LAKE BY SUNDAY MORNING RETURNING A
SOUTHWEST FLOW. A FRONT WILL MOVE ACROSS THE LAKE LATE SUNDAY
SHIFTING THE WINDS TO ONSHORE. AT THIS TIME IT LOOKS LIKE THEY WILL
BE LIGHT ENOUGH NOT TO NEED A SMALL CRAFT ADVISORY. HIGH PRESSURE
WILL MOVE JUST TO THE NORTH OF LAKE ERIE MONDAY INTO TUESDAY. A
SOUTH TO SOUTHWEST FLOW WILL RETURN FOR WEDNESDAY AND THURSDAY. AT
THIS TIME IT DOESN`T LOOK LIKE CONDITIONS WILL MEET SMALL CRAFT
ADVISORY CRITERIA.
A COLD FRONT WILL MOVE ACROSS THE LAKE LATE FRIDAY. A SMALL CRAFT
ADVISORY MAY BE NEEDED MAINLY AFTER THE FRONTAL PASSAGE AND SPECIAL
MARINE WARNINGS MAY BE ISSUED FOR THUNDERSTORMS AHEAD OF THE
FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
703 AM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL BUILD TO THE MID-ATLANTIC ON SUNDAY. LOW
PRESSURE PASSING NORTH OF THE GREAT LAKES WILL PULL A COLD FRONT
SOUTH ACROSS THE AREA SUNDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SATELLITE IMAGERY SHOWS CLEARING TREND CONTINUING TO PUSH
SOUTH...NEARING THE SOUTHERN SHORE OF LAKE ERIE AT 7 AM. STILL
EXPECTING CLOUDS TO BREAK AWAY FROM THE LAKE AND PUSH INLAND THIS
MORNING WITH SOME DIURNAL ENHANCEMENT...THEN CLEARING THIS
AFTERNOON. GOING FORECAST REMAINS ON TRACK.
ORIGINAL DISCUSSION...HIGH PRESSURE IS CENTERED OVER LAKE
MICHIGAN THIS MORNING WITH LIGHT NORTHERLY FLOW MAINTAINING A
STRATOCU DECK OFF OF LAKE ERIE ACROSS EASTERN PORTIONS OF THE
FORECAST AREA. THE RUC HAS BEEN DOING A GOOD JOB OVERNIGHT WITH
THE DEPICTION OF 850MB MOISTURE WHICH SEEMS TO BE A GOOD PROXY FOR
THE CLEARING TREND APPROACHING FROM THE NORTH. A VERY DRY AIRMASS
IS IN PLACE ACROSS THE UPPER GREAT LAKES AND EXPECT THIS TO SETTLE
SOUTH ACROSS LAKE ERIE THIS MORNING AND BRING AN END TO THE LAKE
EFFECT CLOUDS. SOME DIURNAL ENHANCEMENT TO THE CU FIELD WILL OCCUR
THIS MORNING WITH SKIES RANGING FROM MOSTLY SUNNY IN EXTREME NW
OHIO TO MOSTLY CLOUDY IN NW PA. CLOUDS WILL CLEAR FROM NORTH TO
SOUTH THROUGH THE AFTERNOON AS SUBSIDENCE INCREASES WITH VERY DRY
AIR ALOFT. TEMPERATURES WILL WARM 3 TO 5 DEGREES FROM YESTERDAYS
HIGHS AT MOST LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL START OFF OVERHEAD THIS EVENING...BUILDING TO
PENNSYLVANIA OVERNIGHT. CLEAR SKIES...LIGHT WINDS AND SUBSIDENCE
WILL BE A GOOD RECIPE FOR ANOTHER COLD NIGHT ACROSS THE EASTERN HALF
OF THE AREA. OVERNIGHT TEMPERATURES WILL FOLLOW THE DEWPOINTS DOWN
WITH MINS RANGING FROM THE MID 40S WEST TO UPPER 30S EAST. PATCHY
FROST MAY BE POSSIBLE IN SOME OF THE TYPICALLY COOLER LOCATIONS IN
NW PA OVERNIGHT BUT EXPECTING THE COVERAGE TO BE PRETTY ISOLATED SO
LEFT OUT OF THE FORECAST.
LOW PRESSURE NEAR HUDSON BAY WILL TRACK INTO QUEBEC ON SUNDAY WITH A
TRAILING COLD FRONT PUSHING SOUTH ACROSS THE AREA ON SUNDAY NIGHT.
MID AND HIGH CLOUDS WILL OVERSPREAD THE AREA AND THICKEN DURING THE
DAY ON SUNDAY AHEAD OF THE UPPER LEVEL TROUGH DROPPING SOUTH OUT OF
CANADA. KNOCKED TEMPERATURES DOWN A DEGREE OR TWO IN THE WEST ON
SUNDAY IN FAVOR OF MORE CLOUDS. VERY DRY AIR WILL BE SLOW TO
OVERCOME IN THE LOW LEVELS AND EXPECT ONLY SOME SPRINKLES OR AN
ISOLATED SHOWER IN NW OHIO DURING THE LATE AFTERNOON. SCATTERED
SHOWERS WILL OVERSPREAD THE AREA SUNDAY EVENING AS THE FRONT
PUSHES SOUTH TOWARDS THE HIGHER MOISTURE. NOT MUCH INSTABILITY
ACCOMPANYING THIS SYSTEM SO WILL LEAVE THUNDER OUT OF THE
FORECAST. DRY AIR AND NEGATIVE THETA-E ADVECTION ALREADY ARRIVING
BY LATE SUNDAY NIGHT SO SHOWERS SHOULD COME TO A QUICK END EXCEPT
IN THE SNOW BELT WHERE WE WILL SEE SOME LAKE EFFECT SHOWERS
DEVELOP AND LINGER INTO MONDAY MORNING. TEMPERATURES ON MONDAY
WILL BE BACK DOWN IN THE LOW AND MID 60S AGAIN.
STRONG HIGH PRESSURE AND VERY DRY AIR WILL BUILD IN BEHIND THIS NEXT
FRONT AGAIN FOR MONDAY AFTERNOON AND TUESDAY. EXPECTING LOW LEVELS
TO DRY OUT ENOUGH BY MONDAY AFTERNOON FOR THE LAKE EFFECT SHOWERS
TO BE WINDING DOWN. TEMPERATURES ONCE AGAIN DROP INTO THE LOW 40S
ON MONDAY NIGHT...ISOLATED LOCALS INTO THE UPPER 30S IN NW PA.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
DRY WEDNESDAY AND THEN A CHANCE OF SHOWERS AND THUNDERSTORMS RETURN
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. FOR WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT THE THREAT OF PRECIPITATION IS BECAUSE OF
SHORT WAVES IN THE WESTERLY FLOW ALOFT ALONG WITH ADEQUATE MOISTURE.
WEDNESDAY NIGHT SHOULD BE STABLE ENOUGH FOR JUST SHOWERS. A COLD
FRONT WILL MOVE THROUGH FRIDAY AFTERNOON AND EVENING. THE MODELS ARE
IN GENERAL AGREEMENT DURING THIS PERIOD. JUST MADE SOME MINOR
CHANGES TO THE POPS. FOR THE TIME BEING KEPT THE POPS EITHER 30 OR
40 PERCENT. THAT SEEMS REAL GOOD FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT BASED ON THE AMOUNT OF MOISTURE ALOFT. FOR FRIDAY
WHEN THE MOISTURE SEEMS TO GET BETTER AHEAD OF THE FRONT THE POPS
MAY NEED TO BE RAISED IF THE TIMING AND TREND CONTINUES. KEPT CLOSE
TO HPC GUIDANCE FOR THE TEMPERATURE FORECAST WHICH IS A LITTLE ABOVE
NORMAL.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE
TAF PERIOD. THE FLOW WILL REMAIN NORTHERLY INTO THE AFTERNOON
BEFORE WEAKENING. THE QUESTION IS HOW QUICKLY WILL THE CLOUDS GO
AWAY OVER NE OH AND NW PA. THE LAKE AND 850 MB TEMPERATURE
DIFFERENCE IS NEAR 20C TO START AND BY MID AFTERNOON WILL BE DOWN
TO AROUND 15C. THIS DIFFERENCE IS ENOUGH TO KEEP SOME CLOUDS
GOING. HOWEVER WITH PLENTY OF SUBSIDENCE THAT WILL EVENTUALLY WIN
OUT...BUT THE QUESTION IS HOW SOON WILL THAT HAPPEN. BASED ON THE
SATELLITE PICTURES AND USING THE RAP MODEL WILL SCATTER THE CLOUDS
OUT BETWEEN DAYBREAK AND NOON. THE NORTHEAST FLOW COULD SPREAD A
LITTLE CLOUDS TOWARD TOL AND FDY...BUT THEY SHOULD ONLY BE
SCATTERED OR FEW AND VFR. WITH THE HIGH BUILDING IN KEEPING THE
FORECAST DRY.
AS THE FLOW BECOMES OFFSHORE LATE THIS AFTERNOON AND EVENING THE
CLOUDS WILL GO AWAY. SOME CIRRUS FROM THE NEXT SYSTEM MAY START
COMING IN.
OUTLOOK...AREAS OF NON VFR POSSIBLE SUN NIGHT.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE LAKE TODAY. THE BIG
QUESTION IS WILL THE SMALL CRAFT ADVISORY HAVE TO BE EXTENDED FOR A
FEW MORE HOURS. THE TREND FOR THE WINDS AND WAVES IS DEFINITELY
DOWN. BASED ON THE 3 AM MARINE OBSERVATIONS WILL LET THE SMALL CRAFT
ADVISORY EXPIRE. THE NEARSHORE FORECAST WILL HAVE 2 TO 4 FEET TO
START AND THEN SUBSIDING AS THE MORNING AND DAY GOES ON. THE RIP
CURRENT RISK IS CLOSE TO MODERATE MAINLY EARLY THIS MORNING BUT THE
RISK WILL DECREASE QUICKLY TODAY.
THE HIGH WILL MOVE EAST OF THE LAKE BY SUNDAY MORNING RETURNING A
SOUTHWEST FLOW. A FRONT WILL MOVE ACROSS THE LAKE LATE SUNDAY
SHIFTING THE WINDS TO ONSHORE. AT THIS TIME IT LOOKS LIKE THEY WILL
BE LIGHT ENOUGH NOT TO NEED A SMALL CRAFT ADVISORY. HIGH PRESSURE
WILL MOVE JUST TO THE NORTH OF LAKE ERIE MONDAY INTO TUESDAY. A
SOUTH TO SOUTHWEST FLOW WILL RETURN FOR WEDNESDAY AND THURSDAY. AT
THIS TIME IT DOESN`T LOOK LIKE CONDITIONS WILL MEET SMALL CRAFT
ADVISORY CRITERIA.
A COLD FRONT WILL MOVE ACROSS THE LAKE LATE FRIDAY. A SMALL CRAFT
ADVISORY MAY BE NEEDED MAINLY AFTER THE FRONTAL PASSAGE AND SPECIAL
MARINE WARNINGS MAY BE ISSUED FOR THUNDERSTORMS AHEAD OF THE
FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
409 AM EDT SAT SEP 14 2013
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL BUILD TO THE MID-ATLANTIC ON SUNDAY. LOW
PRESSURE PASSING NORTH OF THE GREAT LAKES WILL PULL A COLD FRONT
SOUTH ACROSS THE AREA SUNDAY NIGHT. HIGH PRESSURE WILL RETURN FOR
THE EARLY PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE IS CENTERRED OVER LAKE MICHIGAN THIS MORNING WITH
LIGHT NORTHERLY FLOW MAINTAINING A STRATOCU DECK OFF OF LAKE ERIE
ACROSS EASTERN PORTIONS OF THE FORECAST AREA. THE RUC HAS BEEN
DOING A GOOD JOB OVERNIGHT WITH THE DEPICTION OF 850MB MOISTURE
WHICH SEEMS TO BE A GOOD PROXY FOR THE CLEARING TREND APPROACHING
FROM THE NORTH. A VERY DRY AIRMASS IS IN PLACE ACROSS THE UPPER
GREAT LAKES AND EXPECT THIS TO SETTLE SOUTH ACROSS LAKE ERIE THIS
MORNING AND BRING AN END TO THE LAKE EFFECT CLOUDS. SOME DIURNAL
ENHANCEMENT TO THE CU FIELD WILL OCCUR THIS MORNING WITH SKIES
RANGING FROM MOSTLY SUNNY IN EXTREME NW OHIO TO MOSTLY CLOUDY IN NW
PA. CLOUDS WILL CLEAR FROM NORTH TO SOUTH THROUGH THE AFTERNOON AS
SUBSIDENCE INCREASES WITH VERY DRY AIR ALOFT. TEMPERATURES WILL
WARM 3 TO 5 DEGREES FROM YESTERDAYS HIGHS AT MOST LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HIGH PRESSURE WILL START OFF OVERHEAD THIS EVENING...BUILDING TO
PENNSYLVANIA OVERNIGHT. CLEAR SKIES...LIGHT WINDS AND SUBSIDENCE
WILL BE A GOOD RECIPE FOR ANOTHER COLD NIGHT ACROSS THE EASTERN HALF
OF THE AREA. OVERNIGHT TEMPERATURES WILL FOLLOW THE DEWPOINTS DOWN
WITH MINS RANGING FROM THE MID 40S WEST TO UPPER 30S EAST. PATCHY
FROST MAY BE POSSIBLE IN SOME OF THE TYPICALLY COOLER LOCATIONS IN
NW PA OVERNIGHT BUT EXPECTING THE COVERAGE TO BE PRETTY ISOLATED SO
LEFT OUT OF THE FORECAST.
LOW PRESSURE NEAR HUDSON BAY WILL TRACK INTO QUEBEC ON SUNDAY WITH A
TRAILING COLD FRONT PUSHING SOUTH ACROSS THE AREA ON SUNDAY NIGHT.
MID AND HIGH CLOUDS WILL OVERSPREAD THE AREA AND THICKEN DURING THE
DAY ON SUNDAY AHEAD OF THE UPPER LEVEL TROUGH DROPPING SOUTH OUT OF
CANADA. KNOCKED TEMPERATURES DOWN A DEGREE OR TWO IN THE WEST ON
SUNDAY IN FAVOR OF MORE CLOUDS. VERY DRY AIR WILL BE SLOW TO
OVERCOME IN THE LOW LEVELS AND EXPECT ONLY SOME SPRINKLES OR AN
ISOLATED SHOWER IN NW OHIO DURING THE LATE AFTERNOON. SCATTERD
SHOWERS WILL OVERSPREAD THE AREA SUNDAY EVENING AS THE FRONT
PUSHES SOUTH TOWARDS THE HIGHER MOISTURE. NOT MUCH INSTABILITY
ACCOMPANYING THIS SYSTEM SO WILL LEAVE THUNDER OUT OF THE
FORECAST. DRY AIR AND NEGATIVE THETA-E ADVECTION ALREADY ARRIVING
BY LATE SUNDAY NIGHT SO SHOWERS SHOULD COME TO A QUICK END EXCEPT
IN THE SNOW BELT WHERE WE WILL SEE SOME LAKE EFFECT SHOWERS
DEVELOP AND LINGER INTO MONDAY MORNING. TEMPERATURES ON MONDAY
WILL BE BACK DOWN IN THE LOW AND MID 60S AGAIN.
STRONG HIGH PRESSURE AND VERY DRY AIR WILL BUILD IN BEHIND THIS NEXT
FRONT AGAIN FOR MONDAY AFTERNOON AND TUESDAY. EXPECTING LOW LEVELS
TO DRY OUT ENOUGH BY MONDAY AFTERNOON FOR THE LAKE EFFECT SHOWERS
TO BE WINDING DOWN. TEMPERATURES ONCE AGAIN DROP INTO THE LOW 40S
ON MONDAY NIGHT...ISOLATED LOCALS INTO THE UPPER 30S IN NW PA.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
DRY WEDNESDAY AND THEN A CHANCE OF SHOWERS AND THUNDERSTORMS RETURN
FOR WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. FOR WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT THE THREAT OF PRECIPITATION IS BECAUSE OF
SHORT WAVES IN THE WESTERLY FLOW ALOFT ALONG WITH ADEQUATE MOISTURE.
WEDNESDAY NIGHT SHOULD BE STABLE ENOUGH FOR JUST SHOWERS. A COLD
FRONT WILL MOVE THROUGH FRIDAY AFTERNOON AND EVENING. THE MODELS ARE
IN GENERAL AGREEMENT DURING THIS PERIOD. JUST MADE SOME MINOR
CHANGES TO THE POPS. FOR THE TIME BEING KEPT THE POPS EITHER 30 OR
40 PERCENT. THAT SEEMS REAL GOOD FOR WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT BASED ON THE AMOUNT OF MOISTURE ALOFT. FOR FRIDAY
WHEN THE MOISTURE SEEMS TO GET BETTER AHEAD OF THE FRONT THE POPS
MAY NEED TO BE RAISED IF THE TIMING AND TREND CONTINUES. KEPT CLOSE
TO HPC GUIDANCE FOR THE TEMPERATURE FORECAST WHICH IS A LITTLE ABOVE
NORMAL.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE
TAF PERIOD. THE FLOW WILL REMAIN NORTHERLY INTO THE AFTERNOON
BEFORE WEAKENING. THE QUESTION IS HOW QUICKLY WILL THE CLOUDS GO
AWAY OVER NE OH AND NW PA. THE LAKE AND 850 MB TEMPERATURE
DIFFERENCE IS NEAR 20C TO START AND BY MID AFTERNOON WILL BE DOWN
TO AROUND 15C. THIS DIFFERENCE IS ENOUGH TO KEEP SOME CLOUDS
GOING. HOWEVER WITH PLENTY OF SUBSIDENCE THAT WILL EVENTUALLY WIN
OUT...BUT THE QUESTION IS HOW SOON WILL THAT HAPPEN. BASED ON THE
SATELLITE PICTURES AND USING THE RAP MODEL WILL SCATTER THE CLOUDS
OUT BETWEEN DAYBREAK AND NOON. THE NORTHEAST FLOW COULD SPREAD A
LITTLE CLOUDS TOWARD TOL AND FDY...BUT THEY SHOULD ONLY BE
SCATTERED OR FEW AND VFR. WITH THE HIGH BUILDING IN KEEPING THE
FORECAST DRY.
AS THE FLOW BECOMES OFFSHORE LATE THIS AFTERNOON AND EVENING THE
CLOUDS WILL GO AWAY. SOME CIRRUS FROM THE NEXT SYSTEM MAY START
COMING IN.
OUTLOOK...AREAS OF NON VFR POSSIBLE SUN NIGHT.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE LAKE TODAY. THE BIG
QUESTION IS WILL THE SMALL CRAFT ADVISORY HAVE TO BE EXTENDED FOR A
FEW MORE HOURS. THE TREND FOR THE WINDS AND WAVES IS DEFINITELY
DOWN. BASED ON THE 3 AM MARINE OBSERVATIONS WILL LET THE SMALL CRAFT
ADVISORY EXPIRE. THE NEARSHORE FORECAST WILL HAVE 2 TO 4 FEET TO
START AND THEN SUBSIDING AS THE MORNING AND DAY GOES ON. THE RIP
CURRENT RISK IS CLOSE TO MODERATE MAINLY EARLY THIS MORNING BUT THE
RISK WILL DECREASE QUICKLY TODAY.
THE HIGH WILL MOVE EAST OF THE LAKE BY SUNDAY MORNING RETURNING A
SOUTHWEST FLOW. A FRONT WILL MOVE ACROSS THE LAKE LATE SUNDAY
SHIFTING THE WINDS TO ONSHORE. AT THIS TIME IT LOOKS LIKE THEY WILL
BE LIGHT ENOUGH NOT TO NEED A SMALL CRAFT ADVISORY. HIGH PRESSURE
WILL MOVE JUST TO THE NORTH OF LAKE ERIE MONDAY INTO TUESDAY. A
SOUTH TO SOUTHWEST FLOW WILL RETURN FOR WEDNESDAY AND THURSDAY. AT
THIS TIME IT DOESN`T LOOK LIKE CONDITIONS WILL MEET SMALL CRAFT
ADVISORY CRITERIA.
A COLD FRONT WILL MOVE ACROSS THE LAKE LATE FRIDAY. A SMALL CRAFT
ADVISORY MAY BE NEEDED MAINLY AFTER THE FRONTAL PASSAGE AND SPECIAL
MARINE WARNINGS MAY BE ISSUED FOR THUNDERSTORMS AHEAD OF THE
FRONT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
204 AM EDT SAT SEP 14 2013
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE EAST OVERNIGHT ALLOWING
HIGH PRESSURE TO BUILD OVER THE REGION ON SATURDAY. A COLD FRONT
WILL APPROACH THE GREAT LAKES REGION SUNDAY NIGHT INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATE...ADJUSTED CLOUDS A BIT BUT FORECAST STILL ON TRACK OF
CONTINUING CLOUDS ACROSS THE EAST WHILE SKIES WILL BE CLEAR/PARTLY
CLOUDY WEST. TAPERED POPS BACK TO SLIGHT CHANCE FROM CHANCE FOR
THE REMAINDER OF THE EVENING. ALSO RAISED TEMPS A BIT EAST GIVEN
THE CONTINUING CLOUD COVER.
ORIGINAL..COLD AIR ADVECTION OVER THE LAKES HAS GENERATED SOME
LAKE EFFECT RAIN THIS AFTERNOON. A NORTHERLY FLOW HAS GENERATED A
LAKE HURON FETCH AND AS EXPECTED MOST OF THE SHOWERS ARE OVER THE
WESTERN SUBURBS OF CLE AND EXTENDING SOUTH TO NEAR MANSFIELD. THE
FORECAST CONCERN OVERNIGHT IS HOW LONG TO HANG ON TO THESE
SHOWERS. BOTH THE GFS AND THE NAM DO NOT MOVE THE THERMAL TROF
EAST OF THE AREA UNTIL AFT 06Z. 12Z BUFKIT DATA KEEPS CONDITIONAL
INSTABILITY OVER THE AREA UNTIL NEAR 12Z SAT. THE WILD CARD IS THE
DRY AIR WORKING INTO THE REGION. THIS IS APPARENT BY LOOKING AT
THE SATELLITE OVER CENTRAL LOWER MICHIGAN THIS AFTERNOON AS A DRY
AIR INTRUSION IS QUICKLY ERODING THE CLOUDS. MOS GUIDANCE IS
SUGGESTING THE SHOWERS WILL QUICKLY END THIS EVENING. IT IS MY
EXPERIENCE THAT THE MODELS ARE OFTEN TOO QUICK TO MOVE LAKE EFFECT
OUT OF THE AREA. THE DRY AIR IS A CONCERN AND MAY LIMIT THE AREAL
EXTENT OF THE SHOWERS. SOME OF THE SHOWERS ARE ALSO DIURNAL.
HOWEVER...BASED ON THE FLOW AND THE FACT WE ALREADY HAVE
SHOWERS...I AM INCLINED TO KEEP SCATTERED RAIN SHOWERS OVER MOST
OF NORTHERN OH/NW PA THIS EVENING. I WILL SLOWLY TAPER THE SHOWERS
LATE THIS EVENING. GUIDANCE TEMPERATURES LOOK REASONABLE. THERE
WAS SOME CONCERN OVER NORTHWEST OHIO THAT PATCHY FROST MAY OCCUR
IF THE RIDGE BUILDS IN QUICKLY OVERNIGHT BUT I DO NOT EXPECT
TEMPERATURES TO GET THE COLD. I WILL KEEP TEMPERATURES IN NW OH
MID TO UPPER 30S WITH NO MENTION OF FROST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL BUILD OVER THE FORECAST AREA SATURDAY. ANY
LINGERING EFFECTS OF LAKE EFFECT CLOUDS OR SHOWERS SHOULD QUICKLY
DISSIPATE EARLY IN THE MORNING SATURDAY AS DRY AIR AND A SOUTHWEST
FLOW DEVELOP OVER THE REGION. HIGH PRESSURE SHOULD DOMINATE THROUGH
MOST OF SUNDAY. THE MODELS SHOW AN APPROACHING COLD FRONT SUNDAY
NIGHT INTO MONDAY MORNING. THE GFS SHOWS A WEAK WAVE ON THE FRONT
JUST TO THE WEST OF THE FORECAST AREA SUNDAY EVENING. OVERALL THE
FRONT IS VERY STRONG AND I DO NOT EXPECT A LOT OF PRECIPITATION WITH
THE FRONT. THE CURRENT FORECAST BRINGS A SLIGHT CHC OF RAIN INTO NW
OHIO SUNDAY AFTERNOON. I SEE NO STRONG REASON TO PULL BACK THIS
THREAT SO I WILL LEAVE IT. I WILL BRING SCATTERED SHOWERS ALL AREAS
SUNDAY NIGHT AND POSSIBLY HOLD ON TO A FEW LINGERING SHOWERS OVER NW
PA MONDAY MORNING. HIGH PRESSURE WILL QUICKLY BUILD BACK OVER THE
AREA BY MONDAY AFTERNOON.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
NOT MANY CHANGES TO THE LONG TERM TODAY. THE PERIOD WILL START OFF
WITH HIGH PRESSURE OVER THE REGION. THE HIGH WILL MOVE OFF TO THE
EAST ON WEDNESDAY ALLOWING WARMER SOUTHERLY FLOW TO RETURN. THE
AREA COULD SEE SOME WARM AIR ADVECTION SHOWERS AS EARLY AS WEDNESDAY
NIGHT. BETTER CHANCES WILL COME THURSDAY INTO THURSDAY NIGHT.
THINGS WILL EVENTUALLY DRY OUT FROM WEST TO EAST ON FRIDAY AS LOW
PRESSURE PASSES TO THE NORTH AND DRAGS A COLD FRONT ACROSS THE
REGION. TEMPERATURES WILL START OUT CLOSE TO NORMAL ON TUESDAY BUT
THE REMAINDER OF THE PERIOD WILL AVERAGE A LITTLE ABOVE NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE AREA THROUGH THE
TAF PERIOD. THE FLOW WILL REMAIN NORTHERLY INTO THE AFTERNOON
BEFORE WEAKENING. THE QUESTION IS HOW QUICKLY WILL THE CLOUDS GO
AWAY OVER NE OH AND NW PA. THE LAKE AND 850 MB TEMPERATURE
DIFFERENCE IS NEAR 20C TO START AND BY MID AFTERNOON WILL BE DOWN
TO AROUND 15C. THIS DIFFERENCE IS ENOUGH TO KEEP SOME CLOUDS
GOING. HOWEVER WITH PLENTY OF SUBSIDENCE THAT WILL EVENTUALLY WIN
OUT...BUT THE QUESTION IS HOW SOON WILL THAT HAPPEN. BASED ON THE
SATELLITE PICTURES AND USING THE RAP MODEL WILL SCATTER THE CLOUDS
OUT BETWEEN DAYBREAK AND NOON. THE NORTHEAST FLOW COULD SPREAD A
LITTLE CLOUDS TOWARD TOL AND FDY...BUT THEY SHOULD ONLY BE
SCATTERED OR FEW AND VFR. WITH THE HIGH BUILDING IN KEEPING THE
FORECAST DRY.
AS THE FLOW BECOMES OFFSHORE LATE THIS AFTERNOON AND EVENING THE
CLOUDS WILL GO AWAY. SOME CIRRUS FROM THE NEXT SYSTEM MAY START
COMING IN.
OUTLOOK...AREAS OF NON VFR POSSIBLE SUN NIGHT.
&&
.MARINE...
WINDS CONTINUE TO SLOWLY DIMINISH LATE THIS AFTERNOON. STILL SEEING
SUSTAINED SPEEDS AT 15 TO 20 KNOTS SO WILL KEEP THE SMALL CRAFT
GOING AS IS. WINDS SHOULD DIMINISH OVERNIGHT AND THE WEEKEND WILL
BE FAIRLY QUIET. SPEEDS ON SATURDAY WILL GENERALLY BE IN THE 10 TO
15 KNOT RANGE FROM THE NORTH OR NORTHEAST. WINDS TOMORROW NIGHT
WILL BE LIGHT AS HIGH PRESSURE SLIDES OVER THE LAKE. BY SUNDAY THE
FLOW WILL BE SOUTHERLY. ANOTHER WEAK FRONT IS EXPECTED TO MOVE
ACROSS THE LAKE ON SUNDAY NIGHT WITH THE FLOW RETURNING TO THE
NORTH. COULD COME CLOSE TO NEEDING ANOTHER SMALL CRAFT AT THAT
TIME. ANOTHER HIGH WILL LINGER OVER THE REGION FOR THE FIRST HALF
OF THE WEEKEND. LIGHT NORTHEAST FLOW ON MONDAY WILL BECOME
SOUTHERLY ON WEDNESDAY AS THE HIGH PULLS OFF TO THE EAST.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
LEZ142>149.
&&
$$
SYNOPSIS...GARNET
NEAR TERM...GARNET/TK
SHORT TERM...GARNET
LONG TERM...KUBINA
AVIATION...KIELTYKA
MARINE...KUBINA
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SPOKANE WA
420 PM PDT Sun Sep 15 2013
.SYNOPSIS...
Widespread showers and thunderstorms will occur over the Pacific
Northwest tonight as a vigorous cold front moves through the
region. Locally heavy rain and gusty winds will be possible this
evening over much of central and eastern Washington. The cold
front will bring an end to the record breaking heat. By Monday,
afternoon temperatures will fall into the 70s. Cooler and
occasionally showery weather is expected to persist through much
of the week.
&&
.DISCUSSION...
Tonight: Clusters of showers and thunderstorms are expected to
traverse the Inland Northwest tonight. We have talked extensively
the last few days about the phasing of two low pressure systems
along the coast and the negatively tilted 500mb trough progged to
move over the region tonight. As of 2PM, thunderstorms were
organizing over Oregon over the high terrain around Burns and also
in the vicinity of a deepening surface low near Pendleton. Surface
based instability (CAPE of 800-1100J/KG per RUC analysis) will
fuel rapid development of storms over Oregon late this afternoon.
Dewpoints around Tri-Cities and Pendleton are in the low to mid
50s. Oregon and south central Washington look to have a good shot
of strong to severe thunderstorms capable of damaging wind and
hail. Further north (central and northeast Washington), the
environment appears to be marginal for sustaining strong
convection. A persistent east wind the last few days has generated
a relatively dry boundary layer. Dewpoints from Sandpoint to
Spokane to Pullman to Wenatchee are generally in the upper 40s.
LAPS and RUC analysis shows very little surface based instability
which may end up being detrimental to sustaining strong storms
this evening. We will monitor the situation closely. As the
surface low near Pendleton kicks northward this evening it is
possible that low level moisture will traverse along with the low
and fuel strong storms along the way. There may also be enough
shear and mid-level instability with the vigorous, negatively
tilted trough to maintain storm organization into Wenatchee, Moses
Lake, Pullman and Spokane.
A Flash Flood Watch remains in effect for the burn scar areas
around Wenatchee, Chelan and Leavenworth through 11 PM. Tonight`s
system is probably not as favorable for flash flooding as others
we have seen this summer. Tonight`s system will be more
progressive and mid-level flow should be strong enough to produce
storm motion of 20-30mph. Yet, with the high mid-level moisture
content of the atmosphere and strong forcing, it is possible that
the burn scars could experience a couple rounds of heavy rain this
evening. Certainly worth heightening awareness of these vulnerable
areas with a watch.
Monday: The cold front will be into western Montana by daybreak on
Monday. Morning showers will linger over northeast Washington and
the Idaho Panhandle under the cold core. Strong mid-level dry
advection should bring a more stable air mass to the Idaho
Panhandle during the afternoon hours and we should see a general
decrease in shower activity through the day. Scattered showers and
thunderstorms will be slower to move out of northeast and north
central Washington around Colville and Republic where mid level
moisture will be slower to evacuate. Fall will arrive behind the
cold front. High temperatures will be much more typical of mid
September on Monday with 70s the rule for most of the Inland
Northwest. /GKoch
Monday night through Thursday morning...The brief break in the
weather early in the week will give way to another trough that
will bring showers and thunderstorms to the Inland Northwest. The
trough will move from southwest to northeast, perhaps lifting
northward a little further east than the current system. As a
result, precipitation chances ramp up during the afternoon on
Tuesday and continue into Wednesday night. The western Columbia
Basin into the Waterville Plateau may miss out on a lot of the
precipitation given the track of the storm. However, if the track
is further to the west then chances for precipitation will
increase. The moisture associated with this system will not be as
great as what we will experience this evening/tonight, but PW
values are going to be about 120 to 140 percent of normal, so some
localized heavier rainfall is possible, especially over far
eastern Washington into the Idaho panhandle. Chances for
precipitation will continue over the eastern higher terrain on
Wednesday with the trough not completely out of the region. But
the clouds and rainfall should clear out by Thursday morning.
Temperatures will be cool for mid- September, with Tuesday and
Wednesday afternoon topping out a few degrees below normal.
A quiet day is in store for Thursday, although it will be a
chilly when you wake up. A transient shortwave ridge will
traverse eastern Washington and the Idaho panhandle. A nice
rebound in temperatures will occur Thursday afternoon, with
readings topping out a few degrees above normal. ty
Thursday Night through Sunday: The short lived ridge will exit to
the east allowing another trough of low pressure to influence the
region. The trough and associated cold front will bring lower
temperatures and another good chance for widespread precipitation
across the region. Friday will bring the warmest and nicest day
of the period with strong SW flow ahead of the frontal system that
will push temperatures a handful of degrees above normal. Winds on
Friday will also be mostly terrain driven and remain light.
Friday afternoon is when the system will reach the Cascades
bringing increased precipitation chances. Overnight Friday into
Saturday the remainder of the region will stand the best chance
for precipitation. For right now the areas that will receive the
most rainfall from the system will be the Cascades along with the
NE Washington and ID Panhandle Mountains. The Basin currently
still remains questionable as models are wanting to shadow this
area. I went ahead and added slight chance of thunder for Saturday
based on weak CAPE values and due to the passage of the low center
over the region during this time frame.
Winds will be on the rise once again with the passage of the
front and then also with post frontal winds. Strongest winds look
to be on Saturday afternoon and evening. This system will likely
have some similarities with the system passing today and tomorrow.
Temperatures with the frontal passage will dip back below normal
remaining in the 60s and low 70s for most over the weekend.
Models then hint at another flat ridge after the trough exits to
the east which would bring lower chances for precipitation before
another system takes aim at the region for next week. /Fliehman
&&
.AVIATION...
00Z TAFS: A vigorous cold front will produce showers and
thunderstorms from late this afternoon through Monday morning. Gusty
outflow winds and brief heavy rains will accompany the strongest
cells this evening. There is a chance for a ragged stratus deck
Monday morning behind the cold front at Spokane and Coeur D`Alene,
especially if rains are widespread enough to moisten the boundary
layer. Isolated showers and thunderstorms will redevelop in the
post-frontal air mass Monday afternoon, but should be confined to
the higher elevations north and east of the basin. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 60 73 52 70 47 68 / 70 30 10 40 60 10
Coeur d`Alene 60 70 51 69 47 66 / 70 40 10 50 60 20
Pullman 58 72 46 69 41 68 / 60 20 10 50 50 10
Lewiston 64 81 57 75 52 73 / 60 10 10 40 50 10
Colville 61 73 49 72 46 70 / 80 70 20 60 50 40
Sandpoint 59 68 47 68 43 63 / 60 60 20 50 90 40
Kellogg 58 69 49 68 45 62 / 60 60 10 60 90 30
Moses Lake 62 77 52 74 48 74 / 70 10 10 20 10 10
Wenatchee 61 73 56 72 52 72 / 70 10 10 20 10 10
Omak 62 76 52 74 48 73 / 70 30 10 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Flash Flood Watch until 11 PM PDT this evening for East Slopes
Northern Cascades-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
643 PM CDT SUN SEP 15 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 301 PM CDT SUN SEP 15 2013
THE MAIN FOCUS INTO TOMORROW IS WITH HOW LONG THE LOW LEVEL CLOUD
COVER WILL LINGER WHICH WILL AFFECT HOW MUCH TEMPERATURES CAN DROP
TONIGHT.
CURRENTLY...AN EXPANSIVE STRATOCUMULUS DECK TRAPPED UNDER AN
INVERSION AROUND 850MB IS IN PLACE ACROSS MUCH OF THE UPPER
MISSISSIPPI RIVER VALLEY ON UP TO CENTRAL MINNESOTA. THE MAIN
CLEARING COMES AS YOU APPROACH THE CORE OF A SURFACE HIGH THAT IS
CENTERED OVER SOUTHERN MANITOBA. SOME HOLES HAVE WORKED IN AS WELL
AND EXPECT THAT AS THIS HIGH DROPPING SOUTH TONIGHT...SKIES WILL
CLEAR OUT AS THIS DRIER AIR COMES IN. CONFIDENCE IS NOT THE
HIGHEST IN WHEN THE WIDESPREAD CLEARING WILL GET IN AS THE 15.12Z
NAM/GFS AND 15.18Z RAP ALL SUGGEST DIFFERENT TIMING WITH WHEN THE
LOW LEVEL RH DROPS. BOTH THE NAM AND GFS SHOW THE QUICK DROP IN LOW
LEVEL RH THIS EVENING WHERE AS THE PAST FEW RUNS OF THE RAP
SHOWING SOME HIGHER RH HOLDING ON OVERNIGHT...PARTICULARLY IN
NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THIS CLOUD COVER WILL
HELP TO KEEP TEMPERATURES DOWN GOING INTO THE EVENING AND AS IT
CLEARS IT WILL ALLOW FOR SOME IDEAL RADIATIONAL COOLING WITH WINDS
DROPPING DOWN AS WELL. CONSIDERED BRINGING THE FROST ADVISORY
FURTHER SOUTH INTO THE BOG/LOW LYING AREAS OF
JACKSON/MONROE/JUNEAU/ADAMS COUNTIES THAT TYPICALLY ARE ABOUT 10F
COOLER THAN ITS SURROUNDINGS...BUT CONFIDENCE IS NOT HIGH ON HOW
LONG TEMPERATURES WOULD BE DOWN THAT LOW TO DEVELOP A WIDESPREAD
FROST.
OTHERWISE...IT WILL BE A PLEASANT DAY WEATHER-WISE ON MONDAY AS
THE SURFACE HIGH CONTINUES TO DROP SOUTH AND PROVIDE CLEAR
SKIES...LIGHT WINDS AND HIGHS IN THE MID TO UPPER 60S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 PM CDT SUN SEP 15 2013
THE MAIN FOCUS THROUGH THE REST OF THE WEEK IS WITH THE
RAIN/THUNDER CHANCES TUESDAY THROUGH FRIDAY MORNING.
AFTER THE RIDGE OF HIGH PRESSURE SHIFTS TO THE EAST ON TUESDAY...A
MID LEVEL TROUGH CURRENTLY STALLED OUT OVER THE CENTRAL ROCKIES
WILL TRACK TO THE EAST AND PROVIDE SOME WEAK MID TO UPPER LEVEL
LIFT TUESDAY INTO EARLY WEDNESDAY. INSTABILITY LOOKS LIKE IT
REMAINS RATHER WEAK ON TUESDAY BUT THEN INCREASES TUESDAY NIGHT
AND WEDNESDAY AS THE LOW LEVEL MOISTURE TRANSPORT INCREASES.
OVERALL LIFT LOOKS RATHER WEAK FOR THIS SYSTEM...BUT IT MAY BE
ENOUGH THAT WITH SOME DECENT MOISTURE THAT THERE WILL BE SOME
SCATTERED SHOWERS AND A FEW NON-SEVERE STORMS THAT DEVELOP.
THE MORE IMPRESSIVE LOOKING SYSTEM IS WITH WHAT COMES IN ON
THURSDAY NIGHT. A CLOSED MID LEVEL LOW FORMS ACROSS THE DAKOTAS
ON THURSDAY THAT APPEARS TO BECOME NEGATIVELY TILTED THURSDAY
NIGHT PER THE 15.12Z GFS/GEM. THE 15.12Z ECMWF IS A LITTLE SLOWER
WITH THIS TROUGH BUT DOES SHOW SOME NEGATIVE TILT WITH THE INITIAL
SHORT WAVE THAT COMES THROUGH EARLY ON FRIDAY. AT THE SURFACE...A
DEEPENING LOW PRESSURE SYSTEM WILL TRACK THROUGH SOUTHERN CANADA
AS A COLD FRONT COMES THROUGH ON THURSDAY NIGHT. WILL HAVE TO
WATCH THIS FEATURE FOR THE POTENTIAL OF SOME SEVERE WEATHER BUT AT
THE MOMENT THE NOCTURNAL TIMING DOES NOT LOOK TO BE THE GREATEST.
COOLER TEMPERATURES WILL ENSUE AS WINDS COME AROUND TO THE
NORTHWEST BEHIND THE FRONT WITH THE LOW TRACKING TOWARD HUDSON
BAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 643 PM CDT SUN SEP 15 2013
CHALLENGING CEILING TREND AND HEIGHT FORECAST FOR TAF SITES
THROUGH EARLY MONDAY MORNING. LATEST SATELLITE IMAGERY SHOWS
CELLULAR VFR STRATOCUMULUS ALONG THE I-90 CORRIDOR FOLLOWED BY A
MVFR BROKEN STRATUS DECK ACROSS NORTHERN WISCONSIN. THIS LATTER
DECK IS ADVECTING SOUTHWARD AND PER LATEST TIMING AND FORECAST
SOUNDINGS SHOULD MAKE IT TO KRST/KLSE BY MID EVENING. SOME
INDICATIONS ARE THAT AS DRIER/COOLER AIR ADVECTS IN AT THE SAME
TIME...THE CEILING WILL LOWER TO 1500 TO 2500 FT. SOME UPSTREAMS
OBSERVATIONS ARE ALREADY DOING SO...SO HAVE TRENDED FORECAST IN
THAT DIRECTION. THERE IS ALSO ALREADY A BACK EDGE TO THIS DECK AND
CURRENT TIMING PUTS IT THROUGH AROUND 08Z BUT WILL MONITOR CLOSELY
TO SEE IF IT REMAINS ON TRACK. THERE IS THE POTENTIAL IT COULD
SLOW DOWN...AND LAST UNTIL SUNRISE OR SO.
IF CLEARING LINE DOES PUSH THROUGH OVERNIGHT...THEN THE NEXT
CONCERN IS FOG POTENTIAL AT BOTH KRST/KLSE. THE BIG DETERRENT
REMAINS THE BOUNDARY LAYER WIND FIELD...WHICH HAS BEEN FORECAST TO
BE 10 TO 15 KTS BETWEEN 950 AND 900 MB. HOWEVER...RECENT TRENDS IN
MODEL SOUNDINGS ARE SUGGESTING THIS MIGHT BE OVERDONE AND COULD BE
MORE AROUND 10 KTS. THIS CHANGE...COMBINED WITH THE LOW
TEMP/DEW POINT SPREAD AND WIDESPREAD 0.5 TO 1.0 INCH RAINFALL TODAY
INTRODUCES CONCERN FOR AT LEAST A MVFR VISIBILITY RESTRICTION BUT
COULD NOT RULE A BRIEF PERIOD OF LOWER CONDITIONS...MAINLY IN THE
11 TO 13Z TIME FRAME. THE HIGHER CHANCE OF CLEARING OUT IN TIME
FOR FOG FORMATION IS AT KRST...SO HAVE INTRODUCED A PERIOD OF MVFR
VISIBILITY RESTRICTION. AT KLSE...LOWER CONFIDENCE ON CLOUDS
COMPLETELY CLEARING OUT PRECLUDES MENTION OF FOG AT THIS TIME. ALL
OF THIS IS OF COURSE CONDITIONAL ON CLOUD TRENDS...SO WILL MAKE
ADJUSTMENTS IF THIS SCENARIO APPEARS TO BE PLAYING OUT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY FROM 1 AM TO 8 AM CDT MONDAY FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS TUCSON AZ
922 PM MST SUN SEP 15 2013
.SYNOPSIS...THERE WILL BE ENOUGH MOISTURE FOR ISOLATED TO SCATTERED
THUNDERSTORMS MAINLY EAST OF TUCSON TO START THE WEEK. THE DRIER
WESTERLY FLOW WILL CONTINUE TO DIMINISH MOISTURE THROUGH THE
WEEK...BUT WE MAY HOLD ON TO ENOUGH TO KEEP A FEW MOUNTAIN
THUNDERSTORMS AROUND IN THE AFTERNOONS.
&&
.DISCUSSION...WATER VAPOR IMAGER SHOWS THE WEAK TROUGH EXTENDING
FROM WESTERN COLORADO AND ALONG THE ARIZONA/NEW MEXICO BORDER...WITH
RADAR MOSAIC DETECTING ONLY A FEW SHOWERS AND THUNDERSTORMS
REMAINING OVER THE REGION...MAINLY FROM WHETSTONE TO SIERRA VISTA...
BUT ALSO JUST EAST OF THE ARIZONA BORDER IN WEST CENTRAL NEW MEXICO.
MEANWHILE...A LARGE AREA OF HIGH PRESSURE COVERS THE EASTERN PACIFIC
WATERS...WEST OF THE CENTRAL BAJA PENINSULA.
THE SHOWERS AND STORMS SHOULD GRADUALLY TAPER OFF THROUGH THE LATE
EVENING AND OVERNIGHT HOURS WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES
ACROSS THE REGION. WILL LEAVE SOME SINGLE DIGIT AND SLIGHT CHANCE
POPS IN THE FORECAST...MAINLY ALONG THE AZ/NM BORDER OVERNIGHT.
OTHERWISE...A DRY FORECAST IN STORE ELSEWHERE FOR THE REST OF
TONIGHT.
AS OF 04Z (9 PM MST)...TEMPERATURES ACROSS THE REGION RANGED FROM
THE LOWER 70S TO THE LOWER 90S...WITH THE TUCSON INTL AIRPORT
REPORTING A TEMP OF 92 DEGS AFTER REACHING AN AFTERNOON HIGH OF 100
DEGS. THESE READINGS SEEM TO BE ON TRACK WITH THE EXPECTED OVERNIGHT
LOWS...SO NO CHANGES ARE PLANNED AT THIS TIME...BUT WILL CONTINUE TO
MONITOR AND WILL MAKE ADJUSTMENTS IF NEEDED.
FOR DETAILS REGARDING THE FORECAST BEYOND TONIGHT...PLEASE REFER TO
THE PREVIOUS DISCUSSION BELOW. ALSO SEE THE HYDROLOGY SECTION FOR
INFO REGARDING HIGH WATER LEVELS EXPECTED ON THE GILA RIVER TONIGHT
AND MONDAY.
&&
.AVIATION...VALID THRU 17/00Z.
WEST OF KTUS MOSTLY CLEAR. KTUS EWD/SWD ISOLD-SCT -TSRA/-SHRA THIS
EVENING...AND A FEW -TSRA/-SHRA MAINLY NEAR THE NEW MEXICO BORDER
LATE TONIGHT. OTHERWISE...FEW-SCT CLOUDS MAINLY AT 8-10K FT AGL THIS
EVENING AND OVERNIGHT. SURFACE WIND GENERALLY OUT OF THE EAST AT
5-15KTS AND GUSTY AT TIMES INTO MONDAY. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MAINLY
EAST OF TUCSON THROUGH TUESDAY. SOME DRYING THROUGH THE WEEK BUT WE
MAY HOLD ON TO ENOUGH MOISTURE FOR ISOLATED MOUNTAIN
THUNDERSTORMS...ESPECIALLY NEAR THE INTERNATIONAL BORDER. GUSTY EAST
WINDS AT TIMES THROUGH TUESDAY. OTHERWISE...DAYTIME TEMPERATURES
WILL BE A FEW DEGREES ABOVE NORMAL THIS WEEK.
&&
.HYDROLOGY...THE SAN FRANCISCO RIVER AT CLIFTON CRESTED AT 24.1 FEET
AT 1045 AM MST...BUT HAS SINCE FALLEN TO 18.0 FEET AS OF 5:00 PM
MST. THE RIVER IS EXPECTED TO CONTINUE TO GRADUALLY FALL THIS
EVENING. THEREFORE...THE FLOOD WARNING FOR THE SAN FRANCISCO RIVER
AT CLIFTON WILL BE ALLOWED TO EXPIRE AT 9 PM MST.
THE FLOWS FROM THE SAN FRANCISCO HAVE MOVED INTO THE GILA RIVER
WHICH WILL REMAIN ABOVE BANKFULL AT SOLOMON BUT BELOW MINOR FLOOD
STAGE. AS OF 7:15 PM MST...THE STAGE ON THE GILA RIVER AT SOLOMON
WAS 15.5 FT WITH A FLOW NEAR 22700 CFS. AT THIS LEVEL THE SOLOMON
ROAD BRIDGE APPROACHES BECOME FLOODED. COUNTY OFFICIALS IN GRAHAM
COUNTY HAVE CLOSED THE SOLOMON ROAD BRIDGE AND SANCHEZ ROAD. IT ALSO
MEANS FLOODING OF LOW LYING AGRICULTURAL AREAS NEAR THE RIVER IS
POSSIBLE.
THE GILA RIVER AT GILA NEW MEXICO CRESTED AT A STAGE OF 12.9 FT AND
A FLOW OF NEAR 29000 CFS AS OF 6:30 PM MST. WHILE RISES WILL OCCUR
DURING THE OVERNIGHT AND EARLY MORNING HOURS ON THE GILA RIVER AT
DUNCAN...SOUTH OF CLIFTON AND SOLOMON...THE RIVER SHOULD REMAIN
BELOW BANKFULL LATE TONIGHT AND INTO MONDAY BUT THE FLOOD ADVISORY
WILL BE EXTENDED IN AREAL COVERAGE TO INCLUDE AREAS ALONG THE GILA
AS FAR WEST AS CALVA AND ALSO TO EXTEND THE ADVISORY THROUGH AROUND
MID MORNING MONDAY.
&&
.PREVIOUS DISCUSSION...LATEST HRRR CONTINUES NEAR SURFACE
STREAMLINES FROM NEW MEXICO INTO EASTERN ZONES INTO EARLY MONDAY.
THIS WILL PROBABLY HELP KEEP ISOLATED TO LOW END SCATTERED
CONVECTION GOING MAINLY EAST OF TUCSON WITH AN EMPHASIS ON THE
MOUNTAINS.
LATEST NAMDNG5 CONTINUES EASTERLY SURFACE WINDS INTO TUESDAY AS FAR
WEST AS TUCSON...UP TO BREEZY LEVELS AT TIMES. THIS COULD CAUSE
PROBLEMS WITH OVERNIGHT LOWS IN A COUPLE OF LOCATIONS WITH THE
POTENTIAL FOR THE BOUNDARY LAYER TO REMAIN MIXED AND KEEP
TEMPERATURES UP A BIT. AT THAT POINT THE LOWER LEVEL FLOW STARTS TO
STACK MORE NEATLY AND ADDITIONAL DRYING WILL PROBABLY SEE EVEN
EASTERN MOUNTAINS LOSING THUNDERSTORMS WITH A BELOW 10 PERCENT
FORECAST AREA WIDE BY WEDNESDAY.
SOME MOISTURE PUSH FROM THE TROPICS INTO SONORA AND CHIHUAHUA IS
EXPECTED LATER IN THE WEEK...BUT IS STILL EXPECTED TO HAVE
DIFFICULTY MAKING MUCH PROGRESS FURTHER NORTH WITH THE UNFAVORABLE
WESTERLY FLOW. A WEAK SHORTWAVE RIDGE COULD ALLOW ENOUGH OF A BREAK
IN THE FLOW FOR AREAS MAINLY NEAR THE INTERNATIONAL BORDER TO SEE
ISOLATED CONVECTION AGAIN LATER IN THE WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...FLOOD ADVISORY FOR THE GILA RIVER
AT DUNCAN AND SOLOMON IN EFFECT THROUGH 10 PM MST THIS
EVENING.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
CURRENT DISCUSSION/HYDROLOGY...MOLLERE
PREVIOUS DISCUSSION...MEYER/DROZD
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
337 AM MDT MON SEP 16 2013
.SHORT TERM...AREAS OF DRIZZLE AND FOG WERE OCCURRING EARLY THIS MORNING IN AND NR
THE FOOTHILLS. THIS ACTIVITY MAY LINGER THRU ABOUT 15Z BEFORE
STARTING TO LIFT.
FOR THIS AFTN THE WK UPPER LEVEL TROUGH WILL FINALLY BEGIN TO EXIT
NERN CO. ALTHOUGH THERE WILL BE DRYING ALOFT SMALL MID LVL COLD
POOL COMBINED WITH LINGERING PRECIPITABLE WATER VALUES AROUND AN
INCH COULD STILL LEAD TO ANOTHER ROUND OF SCT SHOWERS AND TSTMS OVER
THE HIGHER TERRAIN THIS AFTN. A FEW OF THE STORMS COULD PRODUCE
RAINFALL AMOUNTS UP TO AN INCH IN 30 MINUTES. WITH VERY SATURATED
CONDITIONS AND AFTER COORDINATION WITH EOC WILL ISSUE AN FFA FM
18Z- 01Z FOR THE FRONT RANGE FOOTHILLS AND ADJACENT PLAINS WEST OF
I-25 FM THE WY BORDER SOUTH TO THE WRN SUBURBS OF DENVER. AS FOR
AFTN HIGHS READINGS WILL BE WARMER OVER NERN CO WITH HIGHS MAINLY
IN THE LOWER TO MID 70S.
BY TONIGHT TSTM ACTIVITY SHOULD END RATHER QUICKLY BY SUNSET WITH NO
ADDITONAL PCPN OVERNIGHT.
.LONG TERM...WEAK UPPER RIDGING AND ZONAL FLOW ALOFT ON TUESDAY
BECOMES SOUTHWESTERLY TUESDAY NIGHT INTO WEDNESDAY AS AN UPPER
TROUGH MOVES EASTWARD. THE UPPER TROUGH AXIS IS PROGGED OVER
WESTERN COLORADO BY 12Z THURSDAY. THE QG VERTICAL VELOCITY FIELDS
HAVE WEAK DOWNWARD MOTION PROGGED FOR THE CWA TUESDAY...THEN WEAK
UPWARD MOTION IS PROGGED LATE TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. LOW LEVEL TROUGHING IS PROGGED OVER THE PLAINS TUESDAY INTO
WEDNESDAY...WITH THE NORMAL DIURNAL WIND PATTERNS PARTLY USURPED
BY DOWNSLOPING. BY 12Z THURSDAY MORNING...A COLD FRONT IS EXPECTED
TO BE MOVING ACROSS THE FORECAST AREA. FOR MOISTURE...TUESDAY IS
PRETTY DRY...WITH A SLIGHT INCREASE OF MOISTURE ON WEDNESDAY.
PRECIPITABLE WATER VALUES OVER THE WESTERN PLAINS ARE 0.40 TO 0.70
INCH ON TUESDAY. THEY INCREASE THERE INTO THE 0.70 TO 0.90 INCH
RANGE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. VALUES FURTHER EAST
ON THE PLAINS ARE A TAD HIGHER. THERE IS LIMITED CAPE PROGGED LATE
DAY TUESDAY...BUT IT INCREASES SOMEWHAT LATE DAY WEDNESDAY. THE
BOUNDARY LAYER DEW POINTS RANGE FROM THE MID 30S F OVER THE
WESTERN FORECAST AREA TO THE LOWER 50S EAST ALL FOUR PERIODS. THE
QPF FIELDS HAD A TAD OF MEASURABLE RAINFALL OVER THE MOUNTAINS
LATE DAY TUESDAY. THERE IS A SLIGHT BIT MORE LATE DAY WEDNESDAY
AND IT ALSO COVERS THE FOOTHILLS. WILL GO MINIMAL POPS LATE DAY
TUESDAY AND WEDNESDAY IN THE MOUNTAINS. FOR TEMPERATURES...
TUESDAY`S HIGHS ARE 3-6 C WARMER THEN TODAY`S. WEDNESDAY`S HIGHS
ARE SIMILAR TO TUESDAY`S. FOR THE LATER DAYS...THURSDAY THROUGH
SUNDAY...MODELS HAVE THE UPPER TROUGH MOVE ACROSS THE CWA ON
THURSDAY. THURSDAY NIGHT INTO SATURDAY MORNING...UPPER RIDGING
MOVES EASTWARD ACROSS THE FORECAST AREA. SOUTHWESTERLY FLOW ALOFT
THEN MOVES IN WITH THE NEXT UPPER TROUGH TO GET INTO COLORADO BY
SUNDAY NIGHT. MOISTURE IS SPARSE UNTIL SUNDAY. TEMPERATURES ARE
AROUND SEASONAL NORMALS THURSDAY AND FRIDAY...THEN ABOVE SATURDAY
AND SUNDAY.
&&
.AVIATION...WK DENVER CYCLONE WAS OVER DENVER EARLY THIS MORNING WITH
SOME AREAS OF FOG AND DRIZZLE. WILL KEEP LIFR CONDITIONS THRU 15Z
WITH IMPROVING CONDITIONS THERAFTER. FOR THIS AFTN THERE WILL BE A
SLIGHT CHC OF TSTMS HOWEVER FOR NOW WILL KEEP ACTIVITY TO THE WEST
AND SW OF DIA AND NOT MENTION IN THE TAF. WINDS THIS AFTN WILL BE
SSE ALTHOUGH THE RAP HAS THEM A BIT MORE ELY. FOR TONIGHT SHOULD
SEE WINDS BECOMING DRAINAGE WITH NO LOW CLOUDS OR FOG EXPECTED
OVERNIGHT.
&&
.HYDROLOGY...AFTER COORDINATION WITH EOC HAVE DECIDED TO ISSUE A FLASH
FLOOD WATCH FOR THE FOOTHILLS AND AREAS WEST OF I-25 FM 18Z-01Z.
THERE IS STILL A POTENTIAL FOR A FEW STORMS TO GENERATE RAINFALL
AMOUNTS UP TO AN INCH IN 30 MINUTES. WITH THE GROUND STILL VERY
SATURATED THIS COULD LEAD TO SOME LOCALIZED FLASH FLOODING IN A
FEW AREAS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH EARLY THIS EVENING
FOR COZ035-036-038-039.
&&
$$
SHORT TERM...RPK
LONG TERM....RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1143 PM MDT SUN SEP 15 2013
.UPDATE...
ISSUED AT 1139 PM MDT SUN SEP 15 2013
FLASH FLOOD WATCH HAS BEEN CANCELLED. SHOWER ACTIVITY OVER FREMONT
COUNTY THAT IS EDGING UP INTO TELLER COUNTY IS WEAKENING...AND DO
NOT FEEL POSES ANY THREAT FOR THE REST OF THE NIGHT.
UPDATE ISSUED AT 809 PM MDT SUN SEP 15 2013
QUICK UPDATE TO INCORPORATE LATEST OBS DATA INTO GRIDDED DATABASE.
ALSO...WITH THE AMOUNT OF ONGOING CONVECTION PERSISTING ACROSS THE
CWA...OPTED TO EXTEND THE FLASH FLOOD WATCH FOR EL PASO AND TELLER
COUNTIES UNTIL MIDNIGHT TONIGHT. MOORE
UPDATE ISSUED AT 535 PM MDT SUN SEP 15 2013
UPDATED GRIDS FOR LATEST TRENDS. HEAVIEST RAIN BEGINNING TO WIND
DOWN. HRRR INDICATES SHOWERS DEVELOPING FROM UPPER ARKANSAS SEWD
TO THE RATON WILL SLOWLY MOVE TO THE NE OVER THE NEXT 3-4 HOURS.
THEN...SHOULD WIND DOWN OVERNIGHT WITH JUST SOME ISOLD SHOWERS
AND PC FG TO DEAL WITH MON MORNING. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 231 PM MDT SUN SEP 15 2013
...FLASH FLOOD AND HEAVY RAIN THREAT INTO TONIGHT...
BUSY DAY TODAY...AND STILL A WAYS TO GO BEFORE WE ARE OUT OF THE
WOODS FROM THE FLOODING THREAT. HEAVIEST CONVECTION SO FAR HAS BEEN
IN A GROUP OF STRONG STORMS OVER THE ERN AND SRN PORTIONS OF KCOS.
SOME TWO PLUS INCH RAINFALL AMTS THERE...CONTRIBUTING TO URBAN
STREET FLOODING. IT LOOKS LIKE THE STRONGER CONVECTION SHOULD
GRADUALLY BUILD SOUTH OF THE PIKES PK REGION LATER THIS
AFTERNOON...BUT IT WILL BE CLOSE...WITH KCOS AND THE WALDO AREA ON
THE N SIDE OF A NW-SE ORIENTED BOUNDARY THAT RUNS THROUGH SE CO.
THIS IS WHERE THE HEAVIEST CONVECTION IS EXPECTED TO BUILD THROUGH
THE FIRST HALF OF THIS EVENING. WITH SLOW STORM MOVEMENT AND VERY
EFFICIENT PRECIP RATES...WILL CONTINUE TO SEE THE POTENTIAL FOR
LOCALIZED FLASH FLOODING THROUGH THIS TIME.
THE GOOD NEWS IS THAT THINGS SHOULD START TO IMPROVE ON MONDAY.
HEAVIEST SHOWERS SHOULD WIND DOWN BY MIDNIGHT TONIGHT. SOME SCT
SHOWERS EARLY MONDAY...ALONG WITH AREAS OF FG OR BR...THEN SOME
PARTIAL CLEARING BY LATE MORNING INTO THE AFTERNOON. WITH SOME MORE
SUN...COULD SEE ISOLD-SCT SHOWERS OR STORMS REDEVELOP BY
AFTERNOON...BUT SHOULD NOT SEE THE PROBLEMS THAT WE HAVE SEEN TODAY.
TEMPS TOMORROW ALSO STARTING TO REBOUND...WITH HIGHS IN THE MID
70S FOR THE PLAINS. ROSE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 231 PM MDT SUN SEP 15 2013
...DRYING TREND...
A DRYING TREND WILL BE IN FULL SWING BY TUESDAY...AS A DRIER
WESTERLY FLOW TAKES OVER. THERE WILL STILL BE A COUPLE ROUNDS OF
SHOWERS AND THUNDERSTORMS TO MOVE THROUGH TUESDAY AND WEDNESDAY...BUT
THESE SHOULD MAINLY AFFECT THE MOUNTAINS AND THE CONCERN FOR HEAVY
RAIN WILL BE MUCH LOWER THAN IN RECENT DAYS.
THURSDAY AND FRIDAY ACTUALLY LOOK DRY OVER THE MOUNTAINS AT THIS
POINT...BUT A LOW LEVEL BOUNDARY MAY BACK UP TO THE EASTERN
MOUNTAINS AND PLAINS BRINGING A FEW SHOWERS OR STORMS TO THOSE
AREAS LATE THURSDAY INTO EARLY FRIDAY.
SATURDAY AND SUNDAY...THE FOCUS FOR SHOWERS AND STORMS SHIFTS
BACK TO MAINLY THE MOUNTAINS AGAIN...BUT STILL NOT GREAT COVERAGE
OR RAINFALL AMOUNTS.
THE PRIMARY STORM THREATS TUESDAY THROUGH SUNDAY WILL PROBABLY BE
MORE IN THE LINES OF LIGHTNING AND GUSTY WINDS THAN ANYTHING ELSE.
ALSO...TEMPERATURES WILL BE SHIFTING BACK TO AT OR ABOVE SEASONAL
AVERAGES DURING THE PERIOD. LW
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1139 PM MDT SUN SEP 15 2013
SOME SHOWER ACTIVITY OVER FREMONT COUNTY TONIGHT THAT WILL SLIDE
UP INTO TELLER COUNTY AS IT WEAKENS. SHOWERS OVER OTERO AND LAS
ANIMAS COUNTIES IS DIMINISHING AS WELL...SO EXPECT IMPROVING
CONDITIONS OVERNIGHT FOR MOST AREAS. HOWEVER...LOW CIGS AND SOME
PATCHY FOG IS PROBABLE THROUGH 14Z FOR KPUB AND MORESO KCOS. VFR
CONDITIONS THEN EXPECTED WITH ISOLATED THUNDERSTORM ACTIVITY OVER
THE HIGHER TERRAIN AFTER 19Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOORE
SHORT TERM...ROSE
LONG TERM...LW
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS MIAMI FL
147 AM EDT MON SEP 16 2013
.AVIATION...
DEEP MOISTURE WILL REMAIN ACROSS SOUTH FLORIDA OVER THE NEXT
COUPLE DAYS. SHOWERS WERE BEGINNING TO REDEVELOP OVER THE ATLANTIC
WATERS TO THE EAST OF KMIA...AND THESE SHOWERS COULD MOVE TOWARDS
THE COAST OVER THE NEXT SEVERAL HOURS. KEPT WITH VCSH FOR
NOW...BUT IT IS POSSIBLE STORMS COULD DEVELOP NEAR THE TAF SITES
BEFORE 12Z. THE DEEP MOISTURE AND LIGHT TO MODERATE EASTERLY FLOW
COMBINED WITH A WEAK SURFACE TROUGH WILL LEAD TO NUMEROUS SHOWERS
AND STORMS ACROSS THE REGION ONCE AGAIN TODAY. SHOWERS AND STORMS
COULD OCCUR AT ANY TIME THROUGHOUT THE DAY...BUT THE MOST LIKELY
PERIOD MAY BE THE LATE MORNING AND EARLY AFTERNOON FOR THE EAST
COAST AND EARLY TO MID AFTERNOON FOR KAPF. SO ADDED TEMPO AND
PROB30 GROUPS TO ACCOUNT FOR THIS AND KEEP CONSISTENT WITH THE
HIGH POPS FORECAST. MVFR/IFR CONDITIONS ARE POSSIBLE IN/NEAR
SHOWERS AND STORMS. AN UPPER LEVEL VORTICITY MAX IS FORECAST TO
MOVE NORTHWARD TOWARDS THE REGION MONDAY NIGHT INTO TUESDAY
MORNING...AND THIS IS FORECAST TO ENHANCE SHOWERS AND STORMS FOR
AT LEAST THE EAST COAST TAF SITES NEAR OR AFTERNOON THE END OF THE
CURRENT TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 930 PM EDT SUN SEP 15 2013/
DISCUSSION...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE
NIGHT. THE HRRR SHOWS A SIGNIFICANT INCREASE IN COVERAGE, WHICH
MAY BE OVERDONE AS IT SHOWS ACTIVITY NOT ONLY DEVELOPING, BUT ALSO
MOVING SOUTH FROM PALM BEACH COUNTY. GIVEN THE GENERAL FLOW TO
WEST AND NORTHWEST, NOT THINKING IT IS TOTALLY ACCURATE. HOWEVER,
WITH SOME ADDITIONAL CONVECTION DEVELOPING, POPS WILL BE LEFT AT
CHC FOR THE COAST AND RAISED TO NEAR CHC FOR THE INTERIOR THROUGH
06Z.
PREV DISCUSSION... /ISSUED 736 PM EDT SUN SEP 15 2013/
AVIATION...
THE EAST COAST TAF SITES WILL SEE EASTERLY WIND FLOW OF 5 TO 10
KNOTS TONIGHT BEFORE INCREASING TO AROUND 10 KNOTS ON MONDAY. THIS
WILL ALLOW FOR SOME SHOWERS AND THUNDERSTORMS TO WORK INTO THE
EAST COAST TAF SITES TONIGHT INTO MONDAY FROM THE ATLANTIC WATERS.
SO WILL CONTINUE WITH THE VCTS FOR THE EAST COAST TAF SITES
TONIGHT INTO MONDAY. HOWEVER...THE START OF THE THREAT OF STORMS
SHOULD BE BETWEEN 3Z AND 4Z FOR KMIA...KOPF...AND KTMB TAF SITES
WHILE REST OF THE EAST COAST TAF SITES WILL SEE THE THUNDERSTORM
THREAT ANYTIME TONIGHT INTO MONDAY.
KAPF TAF SITE WILL ALSO HAVE AN EASTERLY WIND FLOW TONIGHT INTO
MONDAY WITH SPEEDS AT 5 KNOTS OR LESS TONIGHT INCREASING TO AROUND
10 KNOTS BY MONDAY AFTERNOON. KAPF TAF SITE SHOULD REMAIN DRY
TONIGHT BEFORE THE THREAT OF SHOWERS RETURN TO THE TAF SITE BY 13Z
MONDAY AND THUNDERSTORM THREAT BY 17Z MONDAY.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS TONIGHT INTO
MONDAY OVER ALL OF THE TAF SITES...AS ANY SHOWERS OR STORMS THAT
DO TAF SITES WILL BE SHORT LIVE LESS THAN 30 MINUTES. WHEN THE
SHOWERS AND THUNDERSTORM DO AFFECT THE TAF SITES...THE VIS AND
CEILING COULD FALL DOWN INTO THE IFR CONDITIONS AND THIS WILL BE
HANDLE BY A SHORT FUSE TEMPO GROUP.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 232 PM EDT SUN SEP 15 2013/
SYNOPSIS...
DEEP TROPICAL MOISTURE SPREADING NORTHWESTWARD OVER THE AREA WILL
LEAD TO A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS OVER THE NEXT
SEVERAL DAYS.
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
EARLIER CONVECTION IS SPREADING WEST OF THE REGION...AND WITH
LITTLE ADDITIONAL TIME FOR SURFACE HEATING/DESTABILIZATION...RISK
FOR STRONG/SEVERE CONVECTION IS LOW FOR THE REMAINDER OF THE AFTERNOON.
THE NORTH ATLANTIC RIDGE WILL CONTINUE MOVING NORTH AS ANOTHER RIDGE
LOCATED OVER THE GULF STATES WILL CONTINUE MOVING EAST TOWARDS THE
FLORIDA PENINSULA. THESE FEATURES WILL ALLOW FOR THE WIND FLOW TO
PREVAIL FROM THE EAST ACROSS OUR AREA...KEEPING OUR ATMOSPHERE HUMID AND
WARM. WITH THIS...SUMMER-TYPE AFTERNOON CONVECTION IS EXPECTED
THROUGH AT LEAST MID WEEK...WITH HIGHER COVERAGE ACROSS THE INTERIOR
AND WEST.
LONG TERM ...
MODELS SHOW MID LEVEL HIGH PRESSURE OVER THE CENTRAL GULF STATES,
LEADING TO MORE OF A NORTHWEST FLOW ALOFT IN COMBINATION WITH
CONTINUED E/NE LOW LEVEL WINDS. EARLIER RUNS OF THE ECMWF WERE
SHOWING A MID-LEVEL LOW CUTTING OFF OVER THE EASTERN GULF OF
MEXICO, BUT THE LATEST RUN OF THE ECMWF HAS BACKED OFF FROM THAT
SOLUTION AND IS SIMILAR TO THE GFS IN SHOWING A WEAK TROUGH OVER
THE SE GULF AND STRAITS OF FLORIDA. THE NORTHWEST FLOW ALOFT WILL
INTRODUCE SLIGHTLY DRIER AIR WHICH WOULD BRING POPS BACK DOWN TO
THE 30/40 PERCENT RANGE FOR THE LATTER PART OF THE WEEK INTO NEXT
WEEKEND. NOT A DRY FORECAST, BUT PROBABLY NOT AS WET AS THE FIRST
PART OF THE WEEK.
TEMPERATURES THROUGH THE FORECAST PERIOD WILL SHOW LITTLE CHANGE
AS CONTINENTAL AIR REMAINS WELL TO OUR NORTH.
MARINE...
BAND OF STRONG CONVECTION MOVING WEST THROUGH GULF WATERS IS
PROMPTING SPECIAL MARINE WARNINGS FOR WIND GUSTS IN EXCESS OF 40
KTS. THIS FEATURE SHOULD EXIT BY EARLY THIS EVENING...THEN
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED
FOR ALL THE WATERS THROUGH AT LEAST MID-WEEK.
AWAY FROM SHOWERS AND THUNDERSTORMS...EAST WINDS OF 10-15 KTS WILL
PREVAIL WITH SEAS LESS THAN 3 FEET.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 78 88 76 / 50 40 60 40
FORT LAUDERDALE 88 80 89 78 / 60 40 60 40
MIAMI 89 79 89 78 / 60 40 60 40
NAPLES 93 75 91 76 / 70 40 60 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS WICHITA KS
1143 PM CDT SUN SEP 15 2013
.SYNOPSIS...
ISSUED AT 250 PM CDT SUN SEP 15 2013
A COLD FRONT STRETCHING FROM NORTHEAST TO CENTRAL AND
SOUTHWEST KANSAS IS KEEPING ON ITS SOUTHEAST TRACK. THIS FRONT WILL
PUSH THROUGH THIS EVENING...AND A RIDGE WILL BE ON ITS TAILS FOR
MONDAY. A FAIRLY ACTIVE PATTERN IS IN PLACE TO KEEP SYSTEMS MOVING
ACROSS THE CONUS.
&&
.UPDATE...
ISSUED AT 701 PM CDT SUN SEP 15 2013
PUT OUT A QUICK UPDATE TO TWEAK STORM CHANCES OVER THE NEXT FEW HOURS.
CURRENT THINKING IS THAT THE STORMS SHOULD STAY CONFINED TO
SOUTHERN KS FOR THE NEXT FEW HOURS. THERE SHOULD BE A GRADUAL
INCREASE IN COVERAGE TOWARD 06Z AS ISENTROPIC LIFT NORTH OF THE
FRONT INCREASES WITH SOME OF THIS ACTIVITY TRYING TO SPREAD BACK
INTO CENTRAL KS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 250 PM CDT SUN SEP 15 2013
AS MENTIONED IN THE SYNOPSIS...THE COLD FRONT SHOULD CONTINUE TO
SLIDE THROUGH THE REST OF KANSAS AND INTO OKLAHOMA THIS EVENING
AND TONIGHT. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO
BUBBLE UP ALONG AND BEHIND THIS FRONTAL FEATURE THIS AFTERNOON
GIVEN DAYTIME HEATING AND . SOME OF THE STORMS COULD BE STRONG
WITH ABOVE 1K J/KG CAPE VALUES MAINLY IN SOUTH CENTRAL
KANSAS...HOWEVER 0-6KM BULK SHEAR VALUES ARE LESS THAN 30KTS
ACCORDING TO THE MODELS DURING THIS RESPECTIVE TIME FRAME FOR ALL
BUT THE RUC WHICH HAS VALUES JUST AT 40KTS. PRECIPITATION ACTIVITY
IS STILL ANTICIPATED TO LINGER INTO MUCH OF MONDAY AND TUESDAY
WHEN ANOTHER SHORTWAVE IN THE MID LEVELS MOVES THROUGH THE AREA.
ANOTHER TROUGH AT 500MB AND 700MB IS GOING TO MOVE ONSHORE ON
TUESDAY...WHILE THE 850MB TROUGH HALTS AND STARTS TO DEVELOP ALONG
THE FRONT RANGE. EVENING POPS ON TUESDAY WERE SLIGHTLY DROPPED
FROM THE PREVIOUS FORECAST...BUT THE MAIN TRENDS FOR ALL OTHER
PARAMETERS WERE MAINTAINED. COOLER AIR ON MONDAY AND CLOUD COVER
WILL KEEP HIGHS BELOW SEASONAL NORMAL BY 5 DEGREES IN SOUTH
CENTRAL KANSAS AND AS MUCH AS 10 DEGREES IN CENTRAL KANSAS.
TUESDAY SHOULD REBOUND BACK TO ABOVE NORMAL IN THE MID TO UPPER
80S.
JUANITA
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN SEP 15 2013
WEDNESDAY THRU THURSDAY: IN THIS TIME FRAME...THE NEXT SYSTEM IS
EXPECTED TO MOVE THROUGH THE PLAINS. WHILE THE CENTER OF THE LOW
STAYS ACROSS THE CANADIAN AND U.S. BORDER AND MOVES THE FRONT ON
WEDNESDAY INTO THURSDAY...THERE ARE MODEL DIFFERENCES IN ITS TIMING.
ECMWF IS MORE PROGRESSIVE WITH PUSHING THE FRONT THROUGH THE AREA.
THERE COULD BE A CHANGE IN PRECIP ACTIVITY WITH THIS DIFFERENCE.
POPS WERE SLIGHTLY INCREASED FOR THURSDAY AND THURSDAY EVENING WITH
A SMIDGEN OF BETTER CONSISTENCY.
FRIDAY THRU SUNDAY: CURRENT MODEL PREDICTIONS OF THIS TIME FRAME MAKE IT
APPEAR THAT A RIDGE WILL BE IN PLACE. MODEL DISCREPANCIES BEGIN AT
THE START OF NEXT WEEK WHICH MAY MAKE AN IMPACT TO THE FORECAST
FOR SUNDAY DEPENDING ON THE POTENTIAL PROGRESSIVE NATURE OF THE
SYSTEM. THIS IS TOO FAR OUT FOR ANY CERTAINTY IN EITHER PREDICTION
OF THE NEXT SYSTEM TO MOVE THROUGH THE CENTRAL UNITED STATES.
SLIGHT CHANCES WERE PUT IN FOR SUNDAY...BUT AGAIN CONFIDENCE IS
LOW AT THIS TIME.
JUANITA
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1139 PM CDT SUN SEP 15 2013
AVIATION ISSUES WILL REMAIN STORMS TONIGHT THROUGH MOST OF MON
ALONG WITH LOWERING CIGS.
SCT STORMS ARE EXPECTED TO CONTINUE OVERNIGHT AND INCREASE IN
COVERAGE AS AN UPPER IMPULSE LIFTS ACROSS WEST-CENTRAL KS LATE
TONIGHT. SEVERE STORMS ARE NOT EXPECTED WITH THIS ACTIVITY. MVFR
CIGS CURRENTLY COVER CENTRAL KS AND WILL SLOWLY SPILL SOUTH
TONIGHT. DID GO AHEAD AND RUN WITH A FEW HOURS OF IFR LEVELS AT
KRSL AFTER 09Z BUT FEEL MVFR LEVELS WILL BE MORE COMMON. BY EARLY
MON EVENING THE UPPER WAVE WILL BE LIFTING OUT OF THE AREA
DECREASE STORM CHANCES.
LAWSON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 65 78 65 86 / 60 50 30 30
HUTCHINSON 62 75 63 85 / 50 50 30 30
NEWTON 61 74 62 83 / 50 50 30 30
ELDORADO 63 78 63 84 / 60 50 30 30
WINFIELD-KWLD 67 81 65 86 / 60 60 30 30
RUSSELL 58 72 61 86 / 40 40 40 30
GREAT BEND 59 73 62 85 / 40 40 40 30
SALINA 60 73 62 84 / 40 40 40 40
MCPHERSON 61 74 63 84 / 50 40 30 40
COFFEYVILLE 66 83 65 86 / 50 60 40 40
CHANUTE 64 78 63 85 / 60 60 40 40
IOLA 63 76 62 84 / 50 50 40 40
PARSONS-KPPF 65 81 64 85 / 50 60 40 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
311 AM CDT MON SEP 16 2013
.DISCUSSION...
DESPITE AN ANCHORED UPPER LEVEL RIDGE ACROSS THE LOWER MISS
VALLEY...MID AND HIGH CLOUDS ARE PLENTIFUL THIS MORNING ACROSS
ALL OF THE SOUTHERN PLAINS/LOWER MISS VALLEY AND THIS IS HELPING
TO HOLD EARLY MORNING LOW TEMPERATURES UP A BIT. DRIER AIR IN THE
LOW LEVELS TRYING TO HOLD ON NORTH OF THE I-20 CORRIDOR TODAY BUT
65-70+ DEWPOINTS ACROSS OUR EXTREME SOUTHERN ZONES WILL SLOWLY
BEGIN MAKING A COMEBACK OVER THE NEXT 24 HOURS WITH HIGHER
HUMIDITY ENDING A BRIEF BREAK FROM THE HEAT WE ENJOYED THIS
WEEKEND.
THETAE RIDGING IN THE 850-700MB LAYER MARKS THE LEADING EDGE OF
THE SLOWLY ADVANCING HIGHER MOISTURE CONTENT AND THIS AXIS WILL BE
LOCATED ACROSS OUR WESTERN MOST ZONES TODAY. NAM IS SPITTING OUT A
LITTLE QPF IN THIS REGION TODAY...AS IS THE LATEST RAP OUTPUT AND
FOR THIS REASON...HAVE ADDED ISOLATED TSRA TO OUR WESTERN 2/3RDS
FOR THIS AFTN/EVNG WHICH MATCHES UP WELL WITH SPC`S DAYONE
OUTLOOK. OTHERWISE...THE FORECAST FOR MUCH OF THE WORK WEEK WILL
BE BEST DEFINED BY A SHRINKING UPPER LEVEL RIDGE AXIS AND AN EVER
EXPANDING ATMOSPHERIC MOISTURE PROFILE. TEMPERATURES WILL CONTINUE
TO RUN NEARLY 10 DEGREES ABOVE NORMAL FOR MID SEPTEMBER.
MEDIUM RANGE PROGS REMAIN IN EXCELLENT AGREEMENT WITH THE
BREAKDOWN OF THIS RIDGE AND THE DEVELOPMENT OF AN UPPER LEVEL
TROUGH IN THE LEE OF THE ROCKIES BY FRIDAY. THIS TROUGH WILL BE
ACCOMPANIED BY A COLD FRONT LATE FRIDAY NIGHT INTO SATURDAY AND
APPEARS TO HAVE PLENTY OF LIFT AND MOISTURE TO WORK WITH.
THUS...GOOD RAIN CHANCES APPEAR TO ACCOMPANY THIS TROUGH FOR
FRIDAY THROUGH AT LEAST SATURDAY NIGHT. THE GFS IS HAVING SOME
FEEDBACK PROBLEMS BUT A SLOWING FRONT AND PARALLEL FLOW ALONG THE
BOUNDARY WOULD SUPPORT SOME DESCENT RAINFALL RATES AND TOTALS. FOR
NOW...HAVE RAISED THE DAY 5-6 POP FORECAST SLIGHTLY AND WILL
CONTINUE THIS TREND IF NECESSARY AS THE EVENT GETS CLOSER...
ASSUMING WE KEEP GOOD CONTINUITY IN THE MEDIUM RANGE.
PRELIM TO FOLLOW...13.
&&
.AVIATION...
IR SATELLITE INDICATES A FAIRLY EXTENSIVE CIRRUS SHIELD THIS MORNING
ACROSS THE REGION ALONG WITH SOME HIGH BASED STRATOCU IN E TX/NW LA.
VFR CONDITIONS WILL PREVAIL IN THIS ENVIRONMENT AS ANY POTENTIAL FOG
DEVELOPMENT WILL LIKELY BE MITIGATED BY CLOUD COVER...ALTHOUGH CAN
NOT RULE OUT PERIODS OF MVFR VSBYS AT OUR USUAL FOG PRONE TERMINALS.
LIGHT AND VRBL WINDS THIS MORNING TO RETURN TO EASTERLY FOR MUCH OF
THE DAY...WITH SOME PERIODS OF SE FLOW AROUND 5-10 KTS OVER THE WRN
HALF OF THE REGION...WHERE INCREASING GULF MOISTURE WILL ALLOW FOR
THE RETURN OF SOME ISOLD AFTERNOON CONVECTION. DO NOT ANTICIPATE ANY
MORE THAN VCTS MENTION IN THE E TX TAFS AND POSSIBLY SHV AS WELL.
/19/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 96 72 96 73 96 / 20 20 20 20 20
MLU 96 69 95 69 95 / 10 10 20 20 20
DEQ 94 65 93 68 95 / 20 20 20 20 20
TXK 94 68 93 70 95 / 20 20 20 20 20
ELD 94 66 94 67 95 / 10 10 20 20 20
TYR 96 74 95 74 96 / 20 20 20 20 20
GGG 96 72 95 73 96 / 20 20 20 20 20
LFK 96 72 95 72 96 / 20 20 20 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13/19
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
515 AM EDT MON SEP 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 513 AM EDT MON SEP 16 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE WESTERN GREAT LAKES BETWEEN A RIDGE OVER THE PLAINS AND A
TROUGH OVER ERN CANADA. STRONG 700-300 MB QVECTOR DIV IN THE WAKE OF
A SHORTWAVE TROUGH MOVING INTO NEW ENGLAND HAS BROUGHT CLEARING SKIES
OVER MOST OF THE REGION AS A 1030 MB SFC HIGH OVER NW ONTARIO AND NRN
MN BUILDS INTO UPPER MI. HOWEVER...LINGERING NE 10 TO 15 KNOT WINDS
OVER ERN LAKE SUPERIOR ALONG WITH 850 MB TEMPS NEAR 0C HAS GENERATED
LAKE CLOUDS THAT HAVE SPREAD INTO PORTIONS OF NRN UPPER MI. THIS
ALONG WITH CONTINUED LIGHT NE WINDS HAVE KEPT TEMPS FROM DROPPING OFF
AS MUCH OVER THE NORTH AND EAST COMPARED TO INLAND LOCATIONS OVER THE
WEST WHERE READINGS INTO THE LOWER 30S WERE COMMON.
TODAY...EXPECT DAYTIME HEATING/MIXING AND CONTINUED DRY ADVECTION TO
HELP SCOUR OUT THE EARLY MORNING CLOUDS WITH MOSTLY SUNNY CONDITIONS
THEN PREVAILING. THE ABUNDANT SUNSHINE WILL HELP PUSH TEMPS TO NEAR
60 THIS AFTERNOON.
TONIGHT...THE SFC HIGH CENTERED JUST EAST OF THE FCST AREA WILL
CONTINUE TO DOMINATE THE REGION WITH A DRY AIRMASS IN PLACE. ANOTHER
NIGHT WITH VERY FAVORABLE RADIATIONAL COOLING CONDITIONS WILL AGAIN
RESULT IN AREAS OF FROST. THE LOWEST READINGS ARE EXPECTED INTO THE
CNTRL AND ERN PORTION OF THE CWA WHERE THE WINDS WILL BE LIGHTEST.
SOME INCREASE IN SRLY WINDS OVER THE FAR WEST AND DOWNSLOPE
LOCATIONS NEAR LAKE SUPERIOR FROM DEVELOPING LAND BREEZE
SHOULD KEEP TEMPS CLOSER TO 40. SINCE THERE IS ALREADY AN ONGOING
FROST ADVISORY...A NEW ONE FOR TONIGHT WAS NOT POSTED AT THIS TIME TO
AVOID CONFUSION EVEN THOUGH ANOTHER ADVISORY FOR TONIGHT WILL LIKELY
BE NEEDED.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 327 AM EDT MON SEP 16 2013
VERY CONVOLUTED FORECAST FOR MID TO LATE WEEK AS MODELS STRUGGLE WITH
AGREEMENT BETWEEN MODELS AND RUN TO RUN CONTINUITY WITH A SYSTEM
PROGGED TO MOVE ACROSS THE NRN CONUS. THE SHORTWAVE THAT THE SYSTEM
WILL EVOLVE FROM IS CURRENTLY ANALYZED BY MODELS TO BE ABOUT 15
DEGREES LONGITUDE WEST OF THE ATLANTIC COAST OF WA/OR...SO THERE ARE
NOT ANY GOOD OBSERVATIONS OF THE MORE SUBTLE SHORTWAVE ENERGY...OR
EVEN THE DEEPER UPPER LOW/TROUGH THAT IT IS ROTATING AROUND. THE
POOR DATA FOR INITIALIZATION EXPLAINS...AT LEAST PARTIALLY...THE
MODEL DISAGREEMENT AND DISCONTINUITY...ESPECIALLY AFTER ADDITIONAL
ENERGY IS ADDED OVER THE NRN PLAINS THAT MAY CAUSE A RAPID DEEPENING
OF THE SYSTEM. THE SYSTEM AND ADDITIONAL SHORTWAVE ENERGY DOES NOT
MOVE FULLY INTO THE UPPER AIR OBSERVATION NETWORK UNTIL LATE
TUE/EARLY WED...SO IMPROVEMENTS TO CONFIDENCE MAY NOT HAPPEN UNTIL
THAT TIME. BASICALLY...THE SYSTEM JUST HAS THE POTENTIAL TO BRING
RAIN...COLDER TEMPS AND WINDS...BUT IT IS THE FIRST OF THE MORE
SIGNIFICANT DEEPER SYSTEMS OF THE SEASON.
BACK TO A MORE ORGANIZED DISCUSSION STARTING AT 12Z TUE...AN UPPER
LEVEL RIDGE WILL BE OVER THE CWA WITH A SHORTWAVE OVER THE CENTRAL
PLAINS. A SFC HIGH WILL BE CENTERED OVER THE LOWER GREAT
LAKES...WITH THE CWA BETWEEN THE HIGH AND A SFC LOW OVER CENTRAL
SASKATCHEWAN. NO PRECIP IS SHOWN BY MODELS TUE AND TUE NIGHT AS THEY
NOW KEEP THE SHORTWAVE WELL S OF THE CWA. WILL LOWER POPS FOR THIS
PERIOD. LOW LEVEL SW FLOW WILL INCREASE TUE AND TUE NIGHT BETWEEN
THE HIGH TO THE E AND LOW TO THE W...WITH INCREASING LOW LEVEL TEMPS
AS WELL.
FOR WED...MODELS HAVE THE AFOREMENTIONED DEEPER LOW PRESSURE SYSTEM
DEEPENING OVER THE DAKOTAS. SOME MODELS ALSO SHOW SHORTWAVE ENERGY
MOVE THROUGH THE CWA WED...AND CAN NOT RULE THIS OUT AT THIS TIME SO
WILL KEEP AT LEAST SLIGHT CHANCE POPS IN THE FORECAST. LOW LEVEL
TEMPS SHOULD INCREASE AGAIN ON WED...BUT HIGH TEMPS SHOULD BE
SIMILAR TO TUE /UPPER 60S TO AROUND 70/ DUE TO INCREASED CLOUD COVER.
WED NIGHT THROUGH SAT AND PARTIALLY INTO SUN IS WHEN MODEL SOLUTIONS
DIVERGE AND CONFIDENCE IS SIGNIFICANTLY REDUCED. MODEL SPREAD
INCLUDES THE 12Z/15 GEM AND 00Z/16 GFS IN BRINGING THE CLOSED OFF
LOW ACROSS ONTARIO TO JAMES BAY BY FRI NIGHT...DRAGGING THE COLD
FRONT ACROSS THE CWA LATE THU UNTIL FRI. THE 12Z/15 ECMWF IS FARTHER
S...DEEPENING THE LOW AS IT MOVES ACROSS THE CWA FRI NIGHT INTO SAT.
THIS REALLY THROWS OFF WINDS...TEMPS AND PRECIP AND OTHER ASSOCIATED
FIELDS. WILL GO WITH A CONSENSUS OF MODEL GUIDANCE AS IT IS
DIFFICULT AND FUTILE TO CHOOSE ANY ONE SOLUTION AT THIS TIME.
MODELS DO COME BACK INTO BETTER AGREEMENT SUN /ESPECIALLY LATER ON
SUN/ WITH BRINGING AN UPPER RIDGE AXIS TO NEAR THE CWA AND A SFC
RIDGE OVER THE CWA BY 00Z MON. AGAIN...WILL STICK WITH A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 132 AM EDT MON SEP 16 2013
EXCEPT FOR SOME SHALLOW GROUND FOG AT IWD AT TIMES EARLY THIS
MRNG...VFR CONDITIONS WL BE THE RULE AT CMX/IWD THIS FCST PERIOD
WITH INCOMING SFC HI PRES/DRY AIRMASS. AT SAW...A PERSISTENT NNE
UPSLOPE FLOW WITHIN THE LLVL THERMAL TROF FARTHER E OF THE HI CENTER
WL RESULT IN SOME LK EFFECT SC/MVFR CIGS THRU THIS MRNG BEFORE
DAYTIME HEATING MIXES OUT THIS LO CLD. VFR CONDITIONS WL THEN
PREVAIL AT SAW THRU THE REST OF THE PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 513 AM EDT MON SEP 16 2013
WITH SFC HIGH PRES BUILD INTO THE AREA TODAY AND LINGERING INTO
TONIGHT...WINDS WILL REMAIN AT OR BELOW 15 KNOTS. AS THE HIGH SHIFTS
TO THE EAST...SRLY WINDS UP TO 20 KNOTS ARE EXPECTED FROM TUE INTO
WED. WINDS SHOULD THEN REMAIN BELOW 20 KNOTS UNTIL FRI WHEN A TROUGH
MOVING THROUGH THE REGION BRINGS SW TO W WINDS TO AROUND 25 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 9 AM EDT /8 AM CDT/ THIS MORNING FOR
MIZ002>005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
140 AM EDT MON SEP 16 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTH LATE THIS AFTERNOON...
THEN PUSH SOUTH THROUGH THE AREA THIS EVENING INTO TONIGHT. CANADIAN
HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY AND PERSIST
THROUGH WEDNESDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 930 PM SUNDAY...
REST OF TONIGHT: STILL ANTICIPATE A QUIET NIGHT BUT WITH INCREASING
CLOUDS... AND TEMPS MARKEDLY WARMER THAN LAST NIGHT. MSLP AND
SURFACE THETA-E ANALYSES SHOW THAT THE SURFACE HIGH CENTER HAS SLID
OFFSHORE OVER THE LAST SEVERAL HOURS... AND THE SOUTHEASTERLY LOW
LEVEL RETURN FLOW IS ALREADY DRAWING HIGHER DEW POINTS INTO SOUTHERN
AND WESTERN NC. THIS TREND SHOULD PERSIST OVERNIGHT WITH BETTER LOW
LEVEL MOISTURE STEADILY SPREADING OVER CENTRAL NC FROM THE SSW. WARM
AIR ADVECTION AND INCREASING MOISTURE ARE ALSO EVIDENT AT 925-850 MB
WITH HIGHER TEMPS AND LOWER DEW POINT DEPRESSIONS TO OUR SOUTH.
EXPECT AN OVERSPREADING OF STRATOCUMULUS FROM SW TO NE OVER THE
PIEDMONT AND WRN SANDHILLS THROUGH THE NIGHT... A PATTERN PICKED UP
WELL BY THE LATEST HRRR OUTPUT. WE`LL ALSO SEE THE MID AND HIGH
CLOUDS OVER VA/WRN NC/NRN GA (ASSOCIATED WITH A MID LEVEL JET STREAK
TO OUR NW) SPREADING EASTWARD ACROSS NC THROUGH THE NIGHT. IN ALL...
ACROSS CENTRAL NC... EXPECT FAIR TO PARTLY CLOUDY SKIES EAST WITH
SKIES BECOMING MOSTLY CLOUDY WEST. THE HRRR AND WRF-ARW/WRF-NMM
INDICATE A FEW SPRINKLES OVERNIGHT... CERTAINLY NOT OUT OF THE
QUESTION GIVEN THE ANTICIPATED MOIST UPGLIDE AT 295-300K WITH THE
NORTHWARD-MOVING 925-850 MB WARM FRONTAL ZONE. WITH THE CLOUDS
SUPPRESSING COOLING... HAVE NUDGED UP LOWS A BIT... TO RANGE FROM 59
IN THE RURAL NORTHERN BORDER SECTIONS TO 66 NEAR THE SC BORDER. -GIH
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 245 PM SUNDAY...
SHORTWAVE ENERGY DIVING SOUTHEAST OUT OF SOUTHCENTRAL CANADA WILL
LEAD TO FURTHER AMPLIFICATION OF THE UPPER LEVEL TROUGH OVER THE
MID-ATLANTIC AND NEW ENGLAND ON MONDAY. HEIGHT RISES
/SUBSIDENCE/ IN THE WAKE OF THE SHORTWAVE OVER THE OH VALLEY WILL
ALLOW CANADIAN HIGH PRESSURE TO BUILD RAPIDLY SOUTHEAST INTO THE
MID-ATLANTIC LATE MON/MON NIGHT...DRIVING A BACK DOOR COLD FRONT
SOUTHWARD THROUGH CENTRAL NC MONDAY EVENING.
LIMITED LOW-LEVEL MOISTURE RETURN(BL DEWPOINTS ONLY IN THE LOWER TO
MID 60S)AND CONTINUED WARM AIR ALOFT WILL SURRENDER MLCAPE VALUES OF
ONLY 300-700 J/KG ACROSS THE FAR SE ZONES MONDAY AFTERNOON. AT THE
SAME TIME...THE SOUTHWARD MOVING COLD FRONT WILL BEGIN TO OUTRUN
BOTH JET AND SHORTWAVE TROUGH SUPPORT SHIFTING OFF THE NORTHERN
MID-ATLANTIC COAST...RESULTING IN ONLY ISOLATED TO SLIGHT POPS
ACROSS THE AREA MONDAY AFTERNOON AND MONDAY EVENING AS THE FRONT
PUSHES SOUTH THROUGH THE AREA BY AROUND 06Z TUESDAY WITH DELAYED
CLEARING IN THE WAKE OF THE FRONT THROUGH DAYBREAK GIVEN RELATIVELY
MOIST NELY LOW-LEVEL FLOW.
1000-850 MB THICKNESSES WILL INCREASE ANOTHER 10 TO 15 METERS IN
ADVANCE OF THE FRONT MONDAY AFTERNOON...YIELDING ANOTHER 3-5 DEGREES
OF WARMTH. HIGHS IN THE LOWER 80S NORTH TO MID/UPPER 80S SOUTH.
LOWS MON NIGHT WILL BE DRIVEN BY COLD ADVECTION AND WILL DEPEND ON
CLOUD COVER. LOWS RANGING FROM THE UPPER 50S NEAR THE VA BORDER TO
THE LOWER/MID 60S SOUTH.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 245 PM SUNDAY...
TUESDAY THROUGH THURSDAY...BEHIND THE DEPARTING FRONT...SURFACE HIGH
PRESSURE WILL GRADUALLY BUILD EAST AND RIDGE DOWN INTO THE REGION
TUESDAY AND WEDNESDAY BEFORE SHIFTING SOUTH AND BECOMING SITUATED
OVERHEAD BY THURSDAY. THIS WILL RESULT IN FAIR WEATHER FOR CENTRAL
NC. HIGH TEMPS WILL GRADUALLY MODERATE DURING THIS TIME FRAME...FROM
MOSTLY THE UPPER 70S ON TUESDAY TO THE LOW/MID 80S BY THURSDAY.
OVERNIGHT LOWS WILL ALSO UNDERGO A MODERATING TREND...WITH MID/UPPER
50S ON TUESDAY NIGHT AND LOW 60S BY THURSDAY NIGHT.
FRIDAY THROUGH SUNDAY...THE AFOREMENTIONED HIGH PRESSURE WILL BEGIN
TO SHIFT OFFSHORE ON FRIDAY AHEAD OF OUR NEXT SYSTEM. THE RESULTANT
RETURN FLOW/INCREASING MOISTURE MAY ALLOW A FEW SHOWERS/STORMS TO
OCCUR FRIDAY AFTERNOON...MAINLY ACROSS THE WEST...BUT MOST PLACES
SHOULD REMAIN DRY. TEMPS SHOULD CONTINUE THEIR MODERATION TREND...
WITH GENERALLY MID (MAYBE SOME UPPER) 80S EXPECTED. THEN A FRONT
WILL APPROACH THE AREA OVER THE WEEKEND...ALTHOUGH THERE HAS BEEN A
SLOWING TREND WITH THE CURRENT MODEL RUN. DUE TO THE TIMING
UNCERTAINTY...WILL NOT GO ANY HIGHER THAN LOW END CHANCE POPS FOR
NOW...MAINLY CENTERED AROUND THE LATE SATURDAY/SUNDAY TIME FRAME.
TEMPS MAY BE TEMPERED SOME DUE TO THE INCREASED CLOUD COVER...BUT
STILL IN LOW/MID 80S. OVERNIGHT LOWS WILL GENERALLY BE IN THE
LOW/MID 60S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 140 AM MONDAY...
06Z TAF PERIOD:
MVFR CEILINGS ARE EXPECTED TO DEVELOP OVER THE WESTERN PIEDMONT
(ALONG/WEST OF HWY 1) BETWEEN 08-12Z THIS MORNING...WITH THE
INT/GSO/RDU TERMINALS MOST LIKELY TO BE AFFECTED. FURTHER EAST...
CANNOT RULE OUT MVFR FOG AND/OR CEILINGS IN THE SAME TIME FRAME. ANY
SUB-VFR CEILINGS ARE EXPECTED TO SCATTER OUT AND LIFT TO VFR BY LATE
MORNING (15Z). A BACK DOOR COLD FRONT WILL SURGE SOUTHWARD THROUGH
CENTRAL NC THIS EVENING INTO TONIGHT AS STRONG CANADIAN HIGH
PRESSURE BUILDS INTO THE MID-ATLANTIC. EXPECT A FRONTAL PASSAGE
SIMILAR TO LAST FRI/SAT...I.E. VFR ASIDE FROM A SMALL CHANCE FOR
ISOLD CONVECTION AT THE FAY/RWI TERMINALS AND A SHORT PERIOD OF
BREEZY NORTHEAST WINDS IN THE WAKE OF THE FRONT MON NIGHT AND TUE
MORNING.
LOOKING AHEAD:
EXPECT DRY/VFR CONDITIONS ASSOCIATED WITH HIGH PRESSURE TO
PREVAIL THROUGH MID-WEEK. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...HARTFIELD
SHORT TERM...CBL
LONG TERM...KRR
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
144 AM EDT MON SEP 16 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION OVERNIGHT. AN AREA OF
HIGH PRESSURE WILL BEGIN TO WORK INTO THE AREA ON MONDAY AND WILL
REMAIN NEAR THE AREA THROUGH TUESDAY NIGHT. A WEAK DISTURBANCE
WILL MOVE INTO THE REGION ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHOWER ACTIVITY CONTINUES TO PROGRESS SOUTH AND EAST ACROSS THE FA
ALONG A COLD FRONT THAT CURRENTLY STRETCHES FROM AROUND IND TO CLE.
MAIN CONCERN WILL BE IF THE RAIN HOLDS TOGETHER OVERNIGHT TO MAKE
IT TO THE SOUTHERN HALF OF THE FA. THE 00Z KILN SOUNDING CONFIRMS
A DRY LAYER IN THE LOW LEVELS...AND THERE IS UNCERTAINTY WHETHER
THIS WILL ALLOW FOR MUCH /IF ANY/ MEASURABLE PRECIPITATION ACROSS
THE SOUTH. THE LATEST RAP RUNS HAVE TRENDED DRY ACROSS THE
TRI-STATE...AND ALTHOUGH THE SHOWER ACTIVITY HAS BEEN LEANING THAT
WAY...DID NOT HAVE ENOUGH CONFIDENCE TO GO LESS THAN CHANCE POPS
THERE. REGARDLESS...PRECIPITATION WILL REMAIN LIGHT OVERNIGHT WITH
AROUND A TENTH OF AN INCH OR LESS EXPECTED. ONLY MADE MINOR
ADJUSTMENTS TO THE PREVIOUS LOW TEMP FORECAST FOR TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE COLD FRONT WILL BE JUST SOUTH OF THE FA AT THE BEGINNING OF
THE SHORT TERM TIME PERIOD WITH ONLY THE CHANCE FOR A FEW LIGHT
SHOWERS ACROSS FAR SOUTHERN PORTIONS OF THE FA. A FEW ADDITIONAL
LIGHT SHOWERS WILL BE POSSIBLE DURING THE MORNING HOURS TO AROUND
MID DAY ACROSS CENTRAL OHIO WITH H8 WINDS OFF OF THE LAKE.
PRECIPITATION WILL TAPER OFF ACROSS THE FA BY THE AFTERNOON HOURS.
DRY CONDITIONS WILL BE PRESENT FOR THE REMAINDER OF THE SHORT TERM
TIME PERIOD AS HIGH PRESSURE BUILDS INTO THE REGION.
ALTHOUGH CLOUD COVER MAY DECREASE SLIGHTLY DURING THE DAYTIME
MORNING HOURS ON MONDAY ADDITIONAL CLOUD COVER WILL DEVELOP FOR
THE AFTERNOON HOURS WITH CAA. CLOUD COVER WILL DECREASE DURING THE
EVENING HOURS ON MONDAY AND BE MOSTLY CLEAR FOR A LARGE PORTION OF
THE OVERNIGHT HOURS MONDAY NIGHT.
COOL NORTHERLY FLOW AND CLOUD COVER WILL LIMIT TEMPERATURES FROM
RISING TOO MUCH ON MONDAY. HIGH TEMPERATURES WILL GENERALLY BE IN
THE MIDDLE 60S TO LOW 70S. AS CLOUD COVER AND WINDS BEGIN TO
DECREASE MONDAY NIGHT TEMPERATURES WILL FALL INTO THE MIDDLE 40S
TO LOWER 50S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL BE CENTERED OVER NEW ENGLAND AT THE BEGINNING OF
THE FORECAST PERIOD PROVIDING DRY AND BELOW NORMAL CONDITIONS FOR
TUESDAY. BY WEDNESDAY...THE REGION WILL BE ON THE BACK SIDE OF THE
HIGH AND A RETURN FLOW WILL BRING WARMING TEMPERATURES AND AN
INCREASE IN HUMIDITY. PRECIPITATION CHANCES WILL RETURN BY WEDNESDAY
WITH 20 POPS...AND WILL INCREASE ON THURSDAY AND FRIDAY AS A CDFNT
PUSHES OUT OF THE PLAINS AND INTO THE OHIO VALLEY. AFT THE 00Z ECMWF
WAS A LITTLE QUICKER WITH THE FROPA FRIDAY...THE 12Z MODELS HAVE
COME INTO PRETTY GOOD AGREEMENT ON THE FRONTAL TIMING...PUSHING IT
THROUGH FRIDAY NIGHT. KEPT POPS FOR BOTH THURSDAY AND FRIDAY IN THE
CHANCE CATEGORY FOR NOW...BUT IF THE AGREEMENT CONTINUES INTO
TOMORROW...HIGHER POPS MIGHT BE WARRANTED. AS MENTIONED BEFORE THE
MODELS PUSH THE FRONT THROUGH THE REGION FRIDAY NIGHT. THE SOUTH AND
SOUTHEAST COULD SEE SOME LINGERING PCPN EARLY SATURDAY.
ANOTHER HIGH PRESSURE SYSTEM BUILDS DOWN FROM CANADA INTO THE GREAT
LAKES FOR SATURDAY NIGHT INTO SUNDAY.
TEMPERATURES WILL INCREASE FOR WEDNESDAY WITH HIGHS IN THE UPPER 70S
TO LOWER 80S. THURSDAY LOOKS LIKE THE WARMEST DAY OF THE WEEK WITH
HIGHS IN THE LOWER TO MID 80S...BEFORE CLOUDS AND PCPN DROP
TEMPERATURES BACK TO THE LOWER 80S ON FRIDAY. COOLER AIR WILL BUILD
IN NEXT WEEKEND. LOWS TUE NGT WILL BE IN THE 50S...BUT WILL WARM IN
THE 60S WED AND THU NIGHTS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHOWERS WILL CONTINUE ALONG AND BEHIND A COLD FRONT MAKING ITS WAY
ACROSS OUR AREA TONIGHT. SOME MVFR VSBYS ASSOCIATED WITH LIGHT
PRECIPITATION COULD OCCUR THROUGH 08Z MAINLY AT KCMH/KLCK. LATER
TONIGHT IT APPEARS THAT MVFR VSBYS ASSOCIATED WITH MIST WILL
SPREAD ACROSS THE NORTHERN TERMINALS. ANY MVFR VSBYS SHOULD
IMPROVE SHORTLY AFTER SUNRISE. MVFR CIGS MAY DEVELOP CLOSER TO
SUNRISE AND LAST THROUGH THE LATE MORNING. AT THIS TIME IT APPEARS
THE HIGHEST CHANCE FOR THESE MVFR CIGS WILL BE ACROSS KCMH/KLCK.
AM MORE OPTIMISTIC FOR THE REST OF THE TERMINALS AND AM
FORECASTING CIGS TO REMAIN VFR THROUGHOUT THE TAF PERIOD. SOME
BREAKS ARE EXPECTED TO DEVELOP IN OUR CLOUD COVER BY THE
AFTERNOON. SKIES SHOULD BECOME MOSTLY CLEAR LATER IN THE EVENING.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE THURSDAY INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...KURZ
SHORT TERM...NOVAK/SITES
LONG TERM...SITES
AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
303 AM CDT MON SEP 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT MON SEP 16 2013
LOW LEVEL MOISTURE PATTERN IS A BIT CHAOTIC EARLY THIS MORNING
WITH AREAS OF LOW CLOUDS...BUT NOT LOW STRATUS...DEVELOPING AND
MOVING ACROSS THE AREA. THIS IS HAPPENING EVEN AS THE MORE SOLID
DECK HAS BEEN DECREASING FAR SOUTH OVER THE MISSOURI RIVER AREA.
SHORT TERM MODELS ESPECIALLY THE HRRR SEEM TO HAVE A HANDLE ON
THIS. THAT MODEL SHOWS THIS PATTERN CONTINUING THEN THE CLOUDS
DECREASING FAIRLY QUICKLY AROUND NOON. WILL GO WITH THIS IDEA AS
THE AIR GETS HEATED AND MIXED OUT. THAT SHOULD MAKE SKIES MOSTLY
SUNNY BY THE AFTERNOON. A SPLIT BETWEEN GUIDANCE AND CONTINUITY
LOOKS GOOD ON HIGH TEMPERATURES TODAY. TONIGHT THEN STARTS THE
WARM ADVECTION PATTERN OVER A DEEP RANGE OF LEVELS AND THE
ACCOMPANYING INCREASE IN CLOUDS FROM THE SOUTH...ESPECIALLY OVER
THE EASTERN PART OF THE AREA. LOW TEMPERATURES TONIGHT WILL NOT BE
AS COOL AS CURRENT VALUES. THE START OF AN INCREASE IN INSTABILITY
DOES NOT SEEM ENOUGH TO SUPPORT ANY SHOWERS OR STORMS THROUGH
TONIGHT...OR 12Z TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 303 AM CDT MON SEP 16 2013
THE CLOUD INCREASE IN THE WARM ADVECTION PATTERN WILL CONTINUE TO
EVOLVE TUESDAY AND SKIES SHOULD BECOME CLOUDY OR MOSTLY
CLOUDY...ESPECIALLY IN THE EAST. MEANWHILE...INSTABILITY CONTINUES
TO SLOWLY INCREASE BUT MAY BE LIMITED BY THE COPIOUS MOISTURE
ADVECTING IN...AND SUPPORT FOR SHOWERS AND STORMS IS OTHERWISE
QUITE MARGINAL. NEVERTHELESS...WITH MOISTURE INCREASING AT MOST
LEVELS...IT WOULD NOT TAKE MUCH FOR A FEW SHOWERS TO DEVELOP IN
OUR IOWA...MINNESOTA...AND EXTREME SOUTHEAST SD ZONES EVEN IF
THUNDERSTORMS HOLD OFF. WILL MENTION CHANCE OF SHOWERS AND
ISOLATED THUNDER. THIS SHOULD CONTINUE INTO TUESDAY NIGHT BUT
START TO MOVE SLOWLY EAST AND OUT OF THE AREA BY THE START OF
WEDNESDAY AS STRONG WARMING BEGINS TO OUTPACE THE MOISTURE...AND
RELATIVE HUMIDITIES AND CLOUD COVER DROPS OFF. TEMPERATURES WILL
BE WARMER TUESDAY BUT HELD DOWN SOME BY THE CLOUD COVER ESPECIALLY
EAST...THEN TUESDAY NIGHT SHOULD BE QUITE A BIT WARMER.
WEDNESDAY LOOK STILL SET TO BE A MUCH WARMER DAY WITH PLENTY OF
SUNSHINE. THE THREAT OF SHOWERS AND STORMS SHOULD HOLD OFF UNTIL
WEDNESDAY NIGHT WHEN THE COLD FRONT ENTERS THE AREA. HIGHS SHOULD
BE IN THE 80S WITH TEMPERATURES LIKELY REACHING A BIT ABOVE
GUIDANCE VALUES...AND WEDNESDAY NIGHT SHOULD BE WARM AGAIN AS THE
FRONT GETS INTO THE AREA.
FAIRLY POTENT FRONT TRACKS THROUGH THE EASTERN HALF OF THE
FORECAST AREA THURSDAY MORNING. ANY ONGOING SCATTERED SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF THE FRONT WILL TRACK EASTWARD
AND SHOULD DIMINISH BY LATE AFTERNOON. NORTHWEST WINDS WILL BE
BREEZY BEHIND THE FRONT AND PROVIDE A DECENT SHOT OF COLD AIR
ADVECTION THURSDAY NIGHT AND FRIDAY. LOWS WILL DIP INTO THE LOWER
50S ON THURSDAY AND AS COLD AS THE MID 40S FRIDAY NIGHT. WITH A
GENERAL UPPER LEVEL NORTHWEST FLOW PATTERN IN PLACE THROUGH THE
END OF THE WEEK...THE WEATHER WILL REMAIN DRY WITH HIGHS NEAR OR
JUST BELOW SEASONAL NORMALS. RIDGING OVER THE INTERMOUNTAIN WEST
SHIFTS EASTWARD INTO THE HIGH PLAINS FRIDAY NIGHT WITH THE AXIS
MOVING OVERHEAD SATURDAY NIGHT. WITH SOUTHERLY FLOW INCREASING ON
SUNDAY...TEMPERATURES WILL WARM BACK INTO THE MID 70S TO NEAR
80...BUT MAY ALSO BRING THE NEXT POTENTIAL FOR SHOWERS AND
THUNDERSTORMS. MODELS A BIT UNCERTAIN ON TIMING...BUT WILL LEAVE
LOW END CHANCES SUNDAY AND SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1023 PM CDT SUN SEP 15 2013
DRYING FROM THE NORTH HAS REALLY TAKEN OVER SO WILL CONTINUE THE
TREND OF VFR AT KHON AND KFSD. KSUX STILL ON THE EDGE AND IF THEY
ARE NEAR THE EDGE OF THE STRATUS FIELD WHERE THE COOLER AIR IS
MIXING WITH THE REMAINING LOW LEVEL MOISTURE SOME FOG COULD
DEVELOP SO DID INTRODUCE SOME MVFR VISIBILITIES FOR A COUPLE OF
HOURS AROUND SUNRISE AT KSUX. OTHERWISE WILL SEE A SOUTHEAST WIND
INCREASE THROUGH THE PERIOD AND WILL SEE A SMALL THREAT FOR LLWS
AFTER ABOUT 4Z/17.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...
AVIATION...08
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
428 AM CDT MON SEP 16 2013
.DISCUSSION...
THE RADAR THIS MORNING SHOWS A FEW SHOWERS ALONG THE COAST MAINLY
BETWEEN KLBX AND KBYY. SFC ANALYSIS SHOWS DISSIPATING FRONT OVER E
TX THROUGH C LA. ANOTHER COLD FRONT WAS PUSHING THROUGH THE S
PLAINS BUT LIKELY STALL BEFORE EVEN REACHING TX. THERE IS A WEAK
COASTAL TROUGH DUE TO HURRICANE INGRID JUST OFF THE COAST OF
MEXICO. THIS HAS HELPED FORCE SOME SHOWERS BUT MOST OF THE
ACTIVITY IS OVER S TX. ANALYSIS OF 500MB SHOWS THAT THE UPPER
LEVEL RIDGE OVER TX HAS STRENGTHENED AND BROADENED THROUGH THE
GULF COAST INTO THE CAROLINAS. THIS HAS PROVIDED ENOUGH STEERING
TO PUSH INGRID TOWARDS MEXICO. THE 00Z CRP SOUNDING SHOWS NEARLY
2.1 INCHES OF PRECIP WATER AND GOES SOUNDER IMAGERY SHOWS THAT
THIS MUCH MOISTURE ALSO EXTENDS INTO SE TX. CERTAINLY EXPECT
THERE TO BE MORE CONVECTION ONCE DAY TIME HEATING OCCURS. LATEST
06Z HRRR RUN SHOWS CONVECTION FORMING ALONG THE COAST AND THEN
DEVELOPING INLAND BETWEEN HOUSTON AND VICTORIA ALONG US 59. THIS
MAY BE WHERE THE BEST MOISTURE EXISTS AND WHERE SUBSIDENCE FROM
THE UPPER LEVEL RIDGE MAY BE WEAKEST. THAT WILL BE THE MAIN
CHALLENGE THROUGH MID WEEK...FORECASTING CONVECTIVE COVERAGE DUE
TO DEEP MOISTURE AND WHETHER THE RIDGE WILL BE STRONG ENOUGH TO
INHIBIT CONVECTION. DECIDED TO KEEP 20/30 POPS IN THE FORECAST
THROUGH WED. MAX TEMPS WILL ALSO BE TRICKY DUE TO CLOUD COVER BUT
DECIDED TO HEDGE MAX TEMPS A DEGREE OR TWO ABOVE GUIDANCE AS STILL
ENOUGH DAY LIGHT FOR HEATING.
AFTER WEDNESDAY FORECAST MODELS SHOW THE UPPER LEVEL RIDGE
WEAKENING WITH A POTENT TROUGH PUSHING ACROSS THE N PLAINS. THUR
INTO FRI LOOKS LIKE DEEP BOUNDARY LAYER FLOW OFF THE GULF AND EVEN
FROM THE CARIBBEAN DEVELOPS. PRECIP WATER VALUES INCREASE TO 2-2.2
INCHES ON THUR AND MAX OUT AT 2.5 INCHES ON FRI PER THE GFS. BOTH
THE ECMWF AND GFS ARE RATHER WET FOR FRI INTO SAT. AS SUCH WILL
HAVE 30/40 POPS FOR THUR AND THEN 40 POPS FRI INTO SAT. THERE IS
THE POTENTIAL FOR HIGHER POPS AS THIS IS STILL DAY 5/6 OF THE
FORECAST. STILL PLENTY OF TIME FOR THE FORECAST TO CHANGE BUT
THERE IS A LEAST A COUPLE OF DAYS OF MODEL CONSISTENCY FOR THE 00Z
MODELS SHOWING THE POTENTIAL FOR RAINFALL FOR THE END OF THE WEEK.
MAX TEMPS FOR THE WEEK WILL BE IN LINE WITH GUIDANCE...MAYBE A
DEGREE OR TWO WARMER DUE TO THE RIDGE FOR THE NEXT COUPLE OF DAYS.
AS FOR HURRICANE INGRID...AGAIN SHOULD HAVE VERY LITTLE IMPACT
FOR SE TX AS IT SHOULD BE MAKING LANDFALL NORTH OF TAMPICO. THE
HURRICANE IS UNDER THE INFLUENCE OF SOME UPPER LEVEL SHEAR SO IT
IS ONLY A MINIMAL HURRICANE. MAIN IMPACTS FOR SE TX WILL JUST BE
CAUSING AN INFLUX OF MOISTURE AND MARINE INFLUENCES. RIP CURRENTS
WILL BE AN ISSUE AS WILL HIGHER SURF. ELEVATED TIDES OF A FOOT
ABOVE NORMAL LOOKS TO BE THE PEAK SO COASTAL FLOODING WILL NOT BE
A PROBLEM.
39
&&
.MARINE...
MODERATE TO STRONG EASTERLY FLOW WILL CONTINUE TODAY AS WE LIE IN
A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRESSURE ACROSS THE
SOUTHEASTERN UNITED STATES AND HURRICANE INGRID ALONG THE MEXICAN
COAST. WITH SEAS AND WINDS EXPECTED TO REMAIN ELEVATED HAVE
EXTENDED THE SCA FOR ALL OFFSHORE WATERS AND CAUTION FOR BAYS
THROUGH TUESDAY MORNING. TIDE LEVELS WILL REMAIN BETWEEN ONE HALF
AND ONE FOOT ABOVE NORMAL. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 95 75 95 74 96 / 10 10 20 10 20
HOUSTON (IAH) 93 75 94 74 94 / 20 10 20 10 20
GALVESTON (GLS) 90 81 89 80 89 / 20 20 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH TUESDAY MORNING FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 8 AM CDT TUESDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
408 AM CDT MON SEP 16 2013
.DISCUSSION...
EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN EXTENSIVE
PLUME OF TROPICAL MOISTURE OVER CENTRAL MEXICO DUE TO TROPICAL
DEPRESSION MANUEL MOVING ONSHORE THE WEST CENTRAL MEXICAN COAST. A
SECONDARY TROPICAL PLUME OF MOISTURE ASSOCIATED WITH HURRICANE
INGRID REMAINED JUST OFF SHORE OF THE NORTHEAST MEXICAN COAST.
ACROSS THE CONUS...A STRONG UPPER LEVEL TROUGH CONTINUED TO MOVE
SOUTHEAST OVER THE GREAT LAKES REGION TOWARDS THE EAST COAST. THE
SUBTROPICAL RIDGING THAT HAD BEEN DOMINATING THE PLAINS HAD BEEN
FLATTENED AND TILTED OVER THE SOUTHEASTERN UNITED STATES IN
RESPONSE TO THE PASSAGE OF THE STRONG NORTHERN STREAM TROUGH. THIS
LEFT GENERALLY WEAK WESTERLY FLOW OVER THE CENTRAL AND SOUTH
PLAINS THIS MORNING. A WEAK SHORTWAVE TROUGH WAS OBSERVED OVER THE
TX AND OK PANHANDLES...MOVING SLOWLY EAST ALONG A NEARLY STALLED
OUT COLD FRONT.
REGIONAL RADARS SHOWED A LARGE CLUSTER OF SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THE FRONT AND SHORTWAVE TROUGH AT 0830Z OR 330 AM
EXTENDING FROM AMARILLO TO NORTH CENTRAL OK. KFDR RADAR WAS
TRACKING A CONSOLIDATED OUTFLOW BOUNDARY THAT WAS MOVING SOUTHEAST
AWAY FROM THESE SHOWERS AND STORMS TOWARDS NORTH TEXAS.
TODAY...THE RAP AND THE NAM BOTH BOTH INDICATE THAT THE
CONSOLIDATED OUTFLOW BOUNDARY MOVING TOWARDS NORTH TEXAS EARLY
THIS MORNING WILL CONTINUE SOUTHEAST INTO THE CWA JUST AFTER
SUNRISE. THIS BOUNDARY WILL LIKELY STALL OUT SOMEWHERE NORTHWEST
OF THE DFW METROPLEX...WITH THE LATEST GUIDANCE SUGGESTING THE
BOUNDARY WILL COME TO REST NEAR A GAINESVILLE TO WEATHERFORD TO
CISCO LINE BY LATE THIS MORNING. LOCATIONS NEAR AND NORTHWEST OF
THE BOUNDARY WILL LIKELY SEE SOME ISOLATED TO SCATTERED RAIN
SHOWERS AND THUNDERSTORMS DEVELOP BY THE EARLY AFTERNOON HOURS OF
THE DAY. THIS IS PRIMARILY DUE TO THE FACT THAT THERE IS AMPLE
LOW-LEVEL MOISTURE IN PLACE TO SUPPORT PRECIPITATION...WITH THE
FRONT ACTING AS A LIFTING MECHANISM IN AN ENVIRONMENT
CHARACTERIZED WITH LITTLE TO NO CAPPING INVERSION ALOFT. WENT
AHEAD WITH A 30 PERCENT CHANCE OF RAIN FOR THESE LOCATIONS AS A
RESULT...INCLUDING MUCH OF THE DFW AREA.
ELSEWHERE ACROSS NORTH AND CENTRAL TEXAS...THE THERMODYNAMIC
ENVIRONMENT WILL BE NEARLY EQUIVALENT TO LOCATIONS NEAR THE
OUTFLOW BOUNDARY...BUT THERE IS NO OBVIOUS LIFTING MECHANISM TO
SUPPORT THE INITIATION OF SHOWERS AND STORMS THIS AFTERNOON.
DURING THE PEAK HEATING HOURS OF THE DAY...THE BUOYANCY FORCE WILL
BE MAXIMIZED...AND ISOLATED SHOWERS AND STORMS MAY DEVELOP
ANYWHERE ACROSS THE CWA AS A RESULT. MOST PRECIPITATION SHOULD
REMAIN TIED TO DAYTIME HEATING TODAY...THEREFORE WENT AHEAD AND
KEPT A MENTION OF SHOWERS AND STORMS IN THE FORECAST ONLY THROUGH
03Z THIS EVENING.
HEATING IS A BIT OF A CONCERN TODAY BECAUSE WE HAVE EXTENSIVE
CLOUD COVER IN THE FORM OF CIRRUS CLOUDS OVER THE REGION. THESE
CLOUDS MAY BREAK UP A BIT THROUGHOUT THE DAY...BUT WE WILL NEVER
BE FULLY RID OF THEM. REGARDLESS...AT 3 AM REGIONAL TEMPERATURES
WERE HOLDING IN THE MID TO UPPER 70S FOR MOST LOCATIONS. SO
DESPITE PERSISTENT CIRRUS CLOUDS TO CONTEND WITH...A 15 TO 20
DEGREE TEMPERATURE INCREASE SHOULD BE EASY TO ATTAIN BRINGING MOST
LOCATIONS UP INTO THE MID 90S FOR HIGHS WHICH IS WARM ENOUGH TO
SUPPORT ISOLATED STORMS IN THE FORECAST.
CONCERNING THE REMNANTS OF INGRID AND MANUEL...WITH THE
SUBTROPICAL RIDGE FLATTENED OUT...ITS CENTER OF CIRCULATION IS
EXPECTED TO SET UP ANYWHERE FROM SOUTHEAST TX TO THE MISSISSIPPI
COAST THROUGH THIS PERIOD. THE EXACT POSITION OF THIS RIDGE WILL
PLAY A LARGE ROLE IN TROPOSPHERIC STEERING FLOW/TRAJECTORIES FOR
TROPICAL MOISTURE INTO NORTH TX THROUGHOUT THE WEEK HEADED INTO
THIS WEEKEND. IF THE SUBTROPICAL RIDGE SETS UP FURTHER EAST...DEEP
TROPOSPHERIC FLOW WOULD FAVOR TRANSPORTING THE COMBINED MOISTURE
PLUMES FROM MANUEL AND INGRID FROM NORTHERN MEXICO INTO NORTH TX
BY LATE THIS WEEK. IF THE RIDGE SETS UP FURTHER WEST...THE MID AND
UPPER LEVEL TROPICAL MOISTURE WILL BE SHUNTED WEST AWAY FROM
TEXAS. UNFORTUNATELY MODELS REMAIN INCONSISTENT WITH REGARDS TO
THIS SOLUTION...SO DID NOT MAKE ANY HUGE ADJUSTMENTS TO THE
PREVIOUS FORECAST AT THIS TIME.
IN GENERAL...CONTINUE TO CARRY LOW POPS/RAIN CHANCES FROM TUESDAY
THROUGH THURSDAY...BECOMING MORE CONFIDENT AND WIDESPREAD WITH
RAIN CHANCES FOR FRIDAY AND SATURDAY BEFORE RETURNING TO A DRY
FORECAST ON SUNDAY. FOR MORE DETAILS READ ON...
TUESDAY THROUGH THURSDAY...REGARDLESS OF WHAT HAPPENS WITH THE
TROPICAL MOISTURE PLUME FROM THE MEXICAN TROPICAL CYCLONES...THE
MOST IMPORTANT THING TO WATCH DURING THIS TIME FRAME IS THE
DIRECTION OF LOW LEVEL WINDS. LOOKING AT THE 850 MB LEVEL...WINDS
THAT REMAIN EASTERLY NEAR THE GULF COAST WILL PREVENT RICH LOW-
LEVEL MOISTURE FROM MAKING ITS WAY NORTH INTO NORTH TX WHILE
SOUTHEASTERLY WINDS WILL SEND THIS MOISTURE RIGHT UP THE I-35
CORRIDOR. THE ECMWF HAS BEEN THE MOST CONSISTENT IN FORECAST 850
MB WINDS THE PAST FEW DAYS...SO THIS FORECAST CLOSELY FOLLOWS THE
GUIDANCE OF THIS MODEL.
THE ECMWF MAINTAINS EASTERLY WINDS AT 850 MB THROUGH WEDNESDAY
MORNING. AS A RESULT...DROPPED POPS ON TUESDAY TO 10 PERCENT FOR
THE ENTIRE CWA WITH LESS CONFIDENCE IN MOISTURE AVAILABLE AND
INSTABILITY TUESDAY AFTERNOON. THE 850 MB FLOW VEERS THROUGHOUT
THE DAY ON WEDNESDAY SLOWLY SENDING RICH GULF MOISTURE NORTH INTO
THE CWA FROM THE SOUTHEAST WEDNESDAY AFTERNOON. WENT AHEAD WITH 20
PERCENT CHANCE OF STORMS FOR THE SOUTHEASTERN HALF OF THE FORECAST
AREA AS A RESULT. BY THURSDAY AFTERNOON...H850 FLOW IS SOUTH-
SOUTHEASTERLY WHICH WOULD START SENDING SOME DEEPER TROPICAL
MOISTURE INTO THE CWA. WENT AHEAD WITH WIDESPREAD 20 POPS FOR THE
ENTIRE AREA THURSDAY AND THURSDAY NIGHT ASSUMING THE ECMWF PANS
OUT AS EXPECTED. WHILE THE GFS HAS TIMING DIFFERENCES...ONCE THE
850 MB FLOW VEERS AROUND TO THE SOUTHEAST...THE GFS INDICATES
PWATS INCREASE TO 2 INCHES. THIS WOULD BE GETTING CLOSE TO 2
STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR WHICH
CERTAINLY SUPPORTS THE BROAD BRUSHED POPS.
FRIDAY AND SATURDAY...THE BIG QUESTION FOR THIS PERIOD IS...WILL
WE HAVE MID AND UPPER LEVEL TROPICAL MOISTURE IN PLACE COURTESY OF
MANUEL AND INGRID? IF WE DO...POPS WILL HAVE TO BE INCREASED MORE
THAN WHAT WE ARE CARRYING AT THIS TIME. EACH DAY A DIFFERENT MODEL
SHOWS THIS SOLUTION WHILE ANOTHER ONE BACKS OFF. THE CONSENSUS IS
ALWAYS AN ANSWER OF /NO/...BUT THE CONSENSUS NEVER CONSISTS OF THE
SAME MODELS. AS A RESULT CONFIDENCE IS LOW AS TO WHERE THE MEXICAN
TROPICAL MOISTURE PLUME WILL END UP AT THIS TIME.
EITHER WAY...THE CONSENSUS OF MODEL GUIDANCE CONTINUES TO SHOW A
SEASONABLY STRONG TROUGH MOVING EAST OVER THE PLAINS DURING THIS
TIME FRAME. THIS WOULD SEND A STRONGER COLD FRONT SOUTH INTO NORTH
TX WHICH SUPPORTS AT LEAST SCATTERED THUNDERSTORMS AS IT MOVES
SOUTH THROUGH THE REGION. WE ALREADY HAD 30 TO 40 POPS IN THE
FORECAST ALONG THIS FRONT...SO JUST MAINTAINED THIS FORECAST AT
THIS TIME. WILL CONTINUE TO CLOSELY MONITOR THE MEXICAN TROPICAL
MOISTURE PLUME IN THE COMING DAYS. IF THIS MOISTURE IS IN PLACE IT
DOES NOT REALLY CHANGE WHEN WE EXPECT SHOWERS AND STORMS...IT JUST
AFFECTS THE COVERAGE AND AMOUNTS OF RAINFALL. EITHER WAY...WE WILL
LIKELY BE DRY ON SUNDAY AS SUBSIDENCE SWEEPS THROUGH THE REGION.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 95 76 95 77 96 / 30 20 10 10 10
WACO, TX 96 74 96 75 96 / 10 10 10 10 20
PARIS, TX 96 70 95 72 95 / 20 20 10 10 10
DENTON, TX 94 73 94 74 95 / 30 20 10 10 10
MCKINNEY, TX 95 73 95 75 96 / 30 20 10 10 10
DALLAS, TX 97 78 96 79 97 / 30 20 10 10 10
TERRELL, TX 96 75 96 75 97 / 20 20 10 10 10
CORSICANA, TX 97 75 97 76 97 / 10 10 10 10 20
TEMPLE, TX 96 73 95 72 95 / 10 10 10 10 20
MINERAL WELLS, TX 92 71 93 72 94 / 30 20 10 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1148 PM CDT SUN SEP 15 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 301 PM CDT SUN SEP 15 2013
THE MAIN FOCUS INTO TOMORROW IS WITH HOW LONG THE LOW LEVEL CLOUD
COVER WILL LINGER WHICH WILL AFFECT HOW MUCH TEMPERATURES CAN DROP
TONIGHT.
CURRENTLY...AN EXPANSIVE STRATOCUMULUS DECK TRAPPED UNDER AN
INVERSION AROUND 850MB IS IN PLACE ACROSS MUCH OF THE UPPER
MISSISSIPPI RIVER VALLEY ON UP TO CENTRAL MINNESOTA. THE MAIN
CLEARING COMES AS YOU APPROACH THE CORE OF A SURFACE HIGH THAT IS
CENTERED OVER SOUTHERN MANITOBA. SOME HOLES HAVE WORKED IN AS WELL
AND EXPECT THAT AS THIS HIGH DROPPING SOUTH TONIGHT...SKIES WILL
CLEAR OUT AS THIS DRIER AIR COMES IN. CONFIDENCE IS NOT THE
HIGHEST IN WHEN THE WIDESPREAD CLEARING WILL GET IN AS THE 15.12Z
NAM/GFS AND 15.18Z RAP ALL SUGGEST DIFFERENT TIMING WITH WHEN THE
LOW LEVEL RH DROPS. BOTH THE NAM AND GFS SHOW THE QUICK DROP IN LOW
LEVEL RH THIS EVENING WHERE AS THE PAST FEW RUNS OF THE RAP
SHOWING SOME HIGHER RH HOLDING ON OVERNIGHT...PARTICULARLY IN
NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THIS CLOUD COVER WILL
HELP TO KEEP TEMPERATURES DOWN GOING INTO THE EVENING AND AS IT
CLEARS IT WILL ALLOW FOR SOME IDEAL RADIATIONAL COOLING WITH WINDS
DROPPING DOWN AS WELL. CONSIDERED BRINGING THE FROST ADVISORY
FURTHER SOUTH INTO THE BOG/LOW LYING AREAS OF
JACKSON/MONROE/JUNEAU/ADAMS COUNTIES THAT TYPICALLY ARE ABOUT 10F
COOLER THAN ITS SURROUNDINGS...BUT CONFIDENCE IS NOT HIGH ON HOW
LONG TEMPERATURES WOULD BE DOWN THAT LOW TO DEVELOP A WIDESPREAD
FROST.
OTHERWISE...IT WILL BE A PLEASANT DAY WEATHER-WISE ON MONDAY AS
THE SURFACE HIGH CONTINUES TO DROP SOUTH AND PROVIDE CLEAR
SKIES...LIGHT WINDS AND HIGHS IN THE MID TO UPPER 60S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 PM CDT SUN SEP 15 2013
THE MAIN FOCUS THROUGH THE REST OF THE WEEK IS WITH THE
RAIN/THUNDER CHANCES TUESDAY THROUGH FRIDAY MORNING.
AFTER THE RIDGE OF HIGH PRESSURE SHIFTS TO THE EAST ON TUESDAY...A
MID LEVEL TROUGH CURRENTLY STALLED OUT OVER THE CENTRAL ROCKIES
WILL TRACK TO THE EAST AND PROVIDE SOME WEAK MID TO UPPER LEVEL
LIFT TUESDAY INTO EARLY WEDNESDAY. INSTABILITY LOOKS LIKE IT
REMAINS RATHER WEAK ON TUESDAY BUT THEN INCREASES TUESDAY NIGHT
AND WEDNESDAY AS THE LOW LEVEL MOISTURE TRANSPORT INCREASES.
OVERALL LIFT LOOKS RATHER WEAK FOR THIS SYSTEM...BUT IT MAY BE
ENOUGH THAT WITH SOME DECENT MOISTURE THAT THERE WILL BE SOME
SCATTERED SHOWERS AND A FEW NON-SEVERE STORMS THAT DEVELOP.
THE MORE IMPRESSIVE LOOKING SYSTEM IS WITH WHAT COMES IN ON
THURSDAY NIGHT. A CLOSED MID LEVEL LOW FORMS ACROSS THE DAKOTAS
ON THURSDAY THAT APPEARS TO BECOME NEGATIVELY TILTED THURSDAY
NIGHT PER THE 15.12Z GFS/GEM. THE 15.12Z ECMWF IS A LITTLE SLOWER
WITH THIS TROUGH BUT DOES SHOW SOME NEGATIVE TILT WITH THE INITIAL
SHORT WAVE THAT COMES THROUGH EARLY ON FRIDAY. AT THE SURFACE...A
DEEPENING LOW PRESSURE SYSTEM WILL TRACK THROUGH SOUTHERN CANADA
AS A COLD FRONT COMES THROUGH ON THURSDAY NIGHT. WILL HAVE TO
WATCH THIS FEATURE FOR THE POTENTIAL OF SOME SEVERE WEATHER BUT AT
THE MOMENT THE NOCTURNAL TIMING DOES NOT LOOK TO BE THE GREATEST.
COOLER TEMPERATURES WILL ENSUE AS WINDS COME AROUND TO THE
NORTHWEST BEHIND THE FRONT WITH THE LOW TRACKING TOWARD HUDSON
BAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1148 PM CDT SUN SEP 15 2013
NORTHEAST FLOW COMING AROUND HIGH PRESSURE IN NORTHWEST WISCONSIN
IS BRINGING DRIER AIR IN AT THE SURFACE INTO THE TAF SITES. THIS
DRIER SURFACE AIR SHOULD PRECLUDE ANY FOG DEVELOPMENT THIS MORNING.
THE OTHER ISSUE AT LEAST FOR THE EARLY MORNING HOURS IS SOME
LINGERING MVFR TO VFR STRATUS OVER SOUTHERN WISCONSIN. CONTINUED
DEEPER DRY AIR SEEN OVER NORTHERN WISCONSIN SHOULD HELP BREAK UP
THE STRATUS AT LSE AROUND 09Z WITH COMPLETE CLEARING BY 14Z. THE
VALLEY LOCATION OF LSE SHOULD HELP TO KEEP CEILINGS VFR. AT
RST...SOME SCATTERED MVFR CLOUDS ARE POSSIBLE...BEING NEAR THE
WESTERN EDGE OF THE STRATUS SHIFTING SOUTHWESTWARD. THESE TOO
SHOULD CLEAR OUT BY 13-14Z. AFTER 14Z...PLENTIFUL DRY AIR WILL BE
IN PLACE THROUGH TONIGHT TO MAINTAIN VFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FROST ADVISORY UNTIL 8 AM CDT MONDAY FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1107 PM MDT SUN SEP 15 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 344 PM MDT SUN SEP 15 2013
SHOWERS CONTINUE EARLY THIS AFTERNOON OVER THE SOUTHWEST QUARTER
OF THE CWA. ISOLATED STORMS HAVE ALSO DEVELOPED OVER SOUTH CENTRAL
WYOMING. THE HEAVIER RAINFALL WAS ALONG THE NORTHERN FRONT RANGE
OF COLORADO AS OF 20Z. ALL OF THE ACTIVITY WAS CURRENTLY MOVING
SLOWLY NORTH. ALTHOUGH RAINFALL RATES HAVE NOT BEEN LARGE SINCE MID
MORNING OVER AND NEAR THE SOUTHERN LARAMIE RANGE...THEY SHOULD
INCREASE LATE THIS AFTERNOON AND EARLY THIS EVENING. WILL EXTEND
THE FLASH FLOOD WATCH PREVIOUSLY ISSUED UNTIL 03Z. THE RAINFALL
IS BEING PRODUCED BY AN UPSTREAM SHORTWAVE TROUGH LIFTING SLOWLY
NORTHEAST AS WELL AS SURFACE UPSLOPE WIND FLOW. MOISTURE WILL ALSO
STILL BE ABUNDANT OVER THE AREA. THE RAINFALL SHOULD DECREASE AND
END LATER TONIGHT AS THE SURFACE FORCING WEAKENS. THE ABUNDANT LOW
LEVEL MOISTURE WILL HELP TO KEEP LOW CLOUDS OVER MUCH OF THE CWA
ALONG WITH FOG IN SOME AREAS. THE INCREASING SOUTHERLY SURFACE
PRESSURE GRADIENT SHOULD ALLOW FOR MORE STRATUS AND ONLY LIGHT FOG.
WILL ALSO CANCEL THE DENSE FOG ADVISORY WITH FORECAST ISSUANCE AS
FOG HAS DISSIPATED OVER ALL BUT THE HIGHER ELEVATIONS OF THE
SOUTHERN LARAMIE RANGE AS OF 20Z.
THE SHORTWAVE TROUGH AS WELL AS A DEVELOPING SURFACE TROUGH OVER
EASTERN WYOMING WILL HELP FORM SOME SHOWERS AND THUNDERSTORMS
OVER MUCH OF THE CWA MONDAY AFTERNOON AND EARLY EVENING. THE
PRECIPITABLE WATER VALUES WILL STILL BE AROUND AN INCH AHEAD OF THE
SHORTWAVE TROUGH...SO SOME OF THE STORMS OVER THE EAST PART OF THE
CWA COULD PRODUCE A PERIOD OF HEAVY RAINFALL.
OTHERWISE...HEIGHTS ALOFT RISE OVER THE CWA THROUGH 00Z WEDNESDAY.
THE RESULT WILL BE WARMER AND DRIER WEATHER. GUSTY DAYTIME
SOUTHWEST SURFACE WINDS CAN ALSO BE EXPECTED IN AREAS ALONG AND
WEST OF THE LARAMIE RANGE BOTH MONDAY AND TUESDAY.
CLOUDS WILL INCREASE ON TUESDAY AHEAD OF THE NEXT SHORTWAVE TROUGH
CURRENTLY JUST OFF THE PACIFIC NORTHWEST COAST. SOME AFTERNOON
SHOWERS AND THUNDERSTORMS WILL ALSO FORM MAINLY OVER AND WEST OF
THE LARAMIE RANGE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 344 PM MDT SUN SEP 15 2013
PROGRESSIVE UPPER LEVEL TROUGH WILL MOVE ACROSS THE ROCKIES ON
WEDNESDAY WITH A COLD FRONT MOVING THROUGH THE FORECAST AREA
WEDNESDAY EVENING. AHEAD OF THE FRONT...LOOKING AT WARM AND WINDY
CONDITIONS...ESPECIALLY FOR THE WIND PRONE REGIONS OUT WEST.
MOISTURE CONTINUES TO LOOK MEAGER WITH THIS SYSTEM...BUT MAINTAINED
CHANCE POPS IN THE MOUNTAINS AND SLIGHT CHANCE POPS FOR THE PLAINS
WITH THE FRONT. SHOULD SEE A FEW THUNDERSTORMS DEVELOP AHEAD OF THE
FRONT AS WELL WITH CAPE VALUES PROGGED TO INCREASE TO AROUND 500
J/KG IN THE LATE AFTERNOON. TROUGH AXIS WILL MOVE OVERHEAD ON
THURSDAY...BRINGING COOLER TEMPS AND CONTINUED WINDY CONDITIONS
ALONG AND WEST OF THE LARAMIE RANGE AS HIGH PRESSURE BEGINS TO
BUILD IN FROM THE WEST. MAY SEE A FEW SHOWERS IN THE MOUNTAINS
WITH WESTERLY UPSLOPE FLOW AND COOLER TEMPS ALOFT...OTHERWISE WILL
REMAIN DRY. DRY ZONAL FLOW WILL BE OVERHEAD ON FRIDAY WITH TEMPS
WARMING 5 TO 10 DEGREES. EVEN WARMER TEMPS ARE EXPECTED FOR
SATURDAY AS THE NEXT UPPER LEVEL SYSTEM DIGS INTO THE WESTERN
CONUS AND AMPLIFIES THE DOWNSTREAM RIDGE. A FEW MOUNTAIN TSTORMS
ARE POSSIBLE IN THE LATE AFTERNOON IN THIS PATTERN...OTHERWISE
LOOKS TO REMAIN BREEZY AND DRY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING)
ISSUED AT 1103 PM MDT SUN SEP 15 2013
LATEST 11-3.9U SATELLITE IMAGERY SHOWING LOW CLOUDS ADVECTING
NORTH OUT OF NORTHEASTERN COLORADO INTO THE PANHANDLE. THIS
MATCHES UP WELL WITH THE LATEST HRRR FORECAST FOR LOWERING
CEILINGS IN THE PANHANDLE. MOST OF THE PANHANDLE SHOULD FALL INTO
THE IFR CATEGORY AFTER 08Z. THE EXCEPTION BEING KCDR...WHO MIGHT
BE MORE LIKE 10-11Z OR SO. STRATUS LOOKS TO LAST THROUGH THE
16-17Z TIME FRAME BEFORE LIFTING.
&&
.FIRE WEATHER...
ISSUED AT 344 PM MDT SUN SEP 15 2013
FIRE WEATHER CONCERNS WILL BE MINIMAL OVER THE CWA THROUGH NEXT
WEEKEND. THE WIDESPREAD AND SIGNIFICANT RAIN WILL BE COMING TO AN
END OVER THE CWA THIS EVENING...WITH SOME LATE DAY SHOWERS AND
THUNDERSTORMS OVER THE CWA MONDAY THROUGH WEDNESDAY. WARMER AND
DRIER CONDITIONS WILL EXIST OVER THE CWA THROUGH NEXT WEEKEND.
TEMPERATURES WILL RETURN TO NEAR OR ABOVE NORMAL AND MINIMUM
RELATIVE HUMIDITY VALUES WILL BE BETWEEN 25 AND 35 PERCENT OVER THE
LOWER ELEVATIONS. DAYTIME WINDS DO INCREASE OVER THE WEST PART OF
THE CWA MONDAY AND TUESDAY AS A SURFACE TROUGH FORMS ALONG THE
EASTERN WYOMING BORDER. THEN A COLD FRONT WILL MOVE ACROSS THE
CWA WEDNESDAY AFTERNOON AND EARLY EVENING. WINDS AHEAD OF AND
BEHIND THE FRONT WILL GUST AS HIGH AS 40 MPH THROUGH WEDNESDAY
NIGHT...ESPECIALLY IN AREAS ALONG AND WEST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...WEILAND
LONG TERM...RJM
AVIATION...CLAYCOMB
FIRE WEATHER...WEILAND
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
945 AM MDT MON SEP 16 2013
.UPDATE...
&&
.SHORT TERM...WATER VAPOR IMAGERY SHOWING UPPER LOW MOVING VERY
SLOWLY EAST ACROSS CENTRAL COLORADO WITH INDICATIONS OF SOME
DRYING OVER WESTERN COLORADO. PW VALUES FROM GPS ALSO SHOWING A
DECREASE WITH ABOUT A ONE TO TWO TENTHS DROP OF PW FROM FRONT
RANGE WESTWARD. STILL EXPECT MUCH LESS STORM COVERAGE TODAY WITH
THE DRYING FROM THE WEST...HOWEVER STORMS THAT DO DEVELOP COULD
STILL DROP SOME HEAVY RAIN. ACROSS LOWER ELEVATIONS...STILL QUITE
A BIT OF STRATUS WITH SOME BREAKS OCCURRING SOUTH AND WEST OF
DENVER. FOR MOST LOCATIONS TOO STABLE FOR SHOWERS ON THE NORTHEAST
PLAINS BUT MAYBE AN ISOLATED STORM OVER THE PALMDER DIVIDE AND
LOCATIONS CLOSER TO THE FOOTHILLS.
.AVIATION...LOW STRATUS WILL SHOW ONLY SLOW IMPROVEMENT DURING THE
LATE AM AND EARLY AFTERNOON WITH NOT A COMPLETE BREAKOUT OF
STRATUS UNTIL 21-22Z. MORE RAPID IMPROVEMENT LIKELY AT APA WITH
BETTER CLEARING ALREADY NOTED OVER DOUGLAS COUNTY. THERE IS A
WEAK CYLCONE OVER THE AREA WHICH SEEMS CENTERED OVER WESTERN ADAMS
AND MOVING EAST.
&&
.HYDROLOGY...WILL HOLD ONTO FLASH FLOOD WATCH BUT CERTAINLY STORM
COVERAGE WILL BE MUCH LESS TODAY. STILL WITH THE AMOUNT OF
MOISTURE IN THE AIR...HEAVY RAIN IS STILL POSSIBLE WITH STORMS
WITH AMOUNTS OVER AN INCH IN LESS THAN ONE HOUR. MAIN CONCERN
AREAS WILL BE THE FOOTHILLS OVER JEFFERSON...BOULDER AND LARIMER
COUNTIES AND AREAS WITH SATURATED SOILS.
&&
.PREV DISCUSSION... /ISSUED 337 AM MDT MON SEP 16 2013/
SHORT TERM...AREAS OF DRIZZLE AND FOG WERE OCCURRING EARLY THIS MORNING IN AND NR
THE FOOTHILLS. THIS ACTIVITY MAY LINGER THRU ABOUT 15Z BEFORE
STARTING TO LIFT.
FOR THIS AFTN THE WK UPPER LEVEL TROUGH WILL FINALLY BEGIN TO EXIT
NERN CO. ALTHOUGH THERE WILL BE DRYING ALOFT SMALL MID LVL COLD
POOL COMBINED WITH LINGERING PRECIPITABLE WATER VALUES AROUND AN
INCH COULD STILL LEAD TO ANOTHER ROUND OF SCT SHOWERS AND TSTMS OVER
THE HIGHER TERRAIN THIS AFTN. A FEW OF THE STORMS COULD PRODUCE
RAINFALL AMOUNTS UP TO AN INCH IN 30 MINUTES. WITH VERY SATURATED
CONDITIONS AND AFTER COORDINATION WITH EOC WILL ISSUE AN FFA FM
18Z- 01Z FOR THE FRONT RANGE FOOTHILLS AND ADJACENT PLAINS WEST OF
I-25 FM THE WY BORDER SOUTH TO THE WRN SUBURBS OF DENVER. AS FOR
AFTN HIGHS READINGS WILL BE WARMER OVER NERN CO WITH HIGHS MAINLY
IN THE LOWER TO MID 70S.
BY TONIGHT TSTM ACTIVITY SHOULD END RATHER QUICKLY BY SUNSET WITH NO
ADDITONAL PCPN OVERNIGHT.
LONG TERM...WEAK UPPER RIDGING AND ZONAL FLOW ALOFT ON TUESDAY
BECOMES SOUTHWESTERLY TUESDAY NIGHT INTO WEDNESDAY AS AN UPPER
TROUGH MOVES EASTWARD. THE UPPER TROUGH AXIS IS PROGGED OVER
WESTERN COLORADO BY 12Z THURSDAY. THE QG VERTICAL VELOCITY FIELDS
HAVE WEAK DOWNWARD MOTION PROGGED FOR THE CWA TUESDAY...THEN WEAK
UPWARD MOTION IS PROGGED LATE TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. LOW LEVEL TROUGHING IS PROGGED OVER THE PLAINS TUESDAY INTO
WEDNESDAY...WITH THE NORMAL DIURNAL WIND PATTERNS PARTLY USURPED
BY DOWNSLOPING. BY 12Z THURSDAY MORNING...A COLD FRONT IS EXPECTED
TO BE MOVING ACROSS THE FORECAST AREA. FOR MOISTURE...TUESDAY IS
PRETTY DRY...WITH A SLIGHT INCREASE OF MOISTURE ON WEDNESDAY.
PRECIPITABLE WATER VALUES OVER THE WESTERN PLAINS ARE 0.40 TO 0.70
INCH ON TUESDAY. THEY INCREASE THERE INTO THE 0.70 TO 0.90 INCH
RANGE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. VALUES FURTHER EAST
ON THE PLAINS ARE A TAD HIGHER. THERE IS LIMITED CAPE PROGGED LATE
DAY TUESDAY...BUT IT INCREASES SOMEWHAT LATE DAY WEDNESDAY. THE
BOUNDARY LAYER DEW POINTS RANGE FROM THE MID 30S F OVER THE
WESTERN FORECAST AREA TO THE LOWER 50S EAST ALL FOUR PERIODS. THE
QPF FIELDS HAD A TAD OF MEASURABLE RAINFALL OVER THE MOUNTAINS
LATE DAY TUESDAY. THERE IS A SLIGHT BIT MORE LATE DAY WEDNESDAY
AND IT ALSO COVERS THE FOOTHILLS. WILL GO MINIMAL POPS LATE DAY
TUESDAY AND WEDNESDAY IN THE MOUNTAINS. FOR TEMPERATURES...
TUESDAY`S HIGHS ARE 3-6 C WARMER THEN TODAY`S. WEDNESDAY`S HIGHS
ARE SIMILAR TO TUESDAY`S. FOR THE LATER DAYS...THURSDAY THROUGH
SUNDAY...MODELS HAVE THE UPPER TROUGH MOVE ACROSS THE CWA ON
THURSDAY. THURSDAY NIGHT INTO SATURDAY MORNING...UPPER RIDGING
MOVES EASTWARD ACROSS THE FORECAST AREA. SOUTHWESTERLY FLOW ALOFT
THEN MOVES IN WITH THE NEXT UPPER TROUGH TO GET INTO COLORADO BY
SUNDAY NIGHT. MOISTURE IS SPARSE UNTIL SUNDAY. TEMPERATURES ARE
AROUND SEASONAL NORMALS THURSDAY AND FRIDAY...THEN ABOVE SATURDAY
AND SUNDAY.
AVIATION...WK DENVER CYCLONE WAS OVER DENVER EARLY THIS MORNING WITH
SOME AREAS OF FOG AND DRIZZLE. WILL KEEP LIFR CONDITIONS THRU 15Z
WITH IMPROVING CONDITIONS THERAFTER. FOR THIS AFTN THERE WILL BE A
SLIGHT CHC OF TSTMS HOWEVER FOR NOW WILL KEEP ACTIVITY TO THE WEST
AND SW OF DIA AND NOT MENTION IN THE TAF. WINDS THIS AFTN WILL BE
SSE ALTHOUGH THE RAP HAS THEM A BIT MORE ELY. FOR TONIGHT SHOULD
SEE WINDS BECOMING DRAINAGE WITH NO LOW CLOUDS OR FOG EXPECTED
OVERNIGHT.
HYDROLOGY...AFTER COORDINATION WITH EOC HAVE DECIDED TO ISSUE A FLASH
FLOOD WATCH FOR THE FOOTHILLS AND AREAS WEST OF I-25 FM 18Z-01Z.
THERE IS STILL A POTENTIAL FOR A FEW STORMS TO GENERATE RAINFALL
AMOUNTS UP TO AN INCH IN 30 MINUTES. WITH THE GROUND STILL VERY
SATURATED THIS COULD LEAD TO SOME LOCALIZED FLASH FLOODING IN A
FEW AREAS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 7 PM MDT THIS EVENING FOR COZ035-036-038-
039.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....RJK
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS ALBANY NY
1007 AM EDT MON SEP 16 2013
.SYNOPSIS...
.AN UPPER LEVEL DISTURBANCE WILL PRODUCE ISOLATED TO
SCATTERED SHOWERS ACROSS THE REGION THIS AFTERNOON. ANOTHER LARGE
HIGH PRESSURE SYSTEM WILL BUILD IN FROM THE UPPER GREAT LAKES
TONIGHT AND TUESDAY...THEN SETTLE JUST OFF THE EAST COAST DURING THE
MIDDLE AND END OF THE WORK WEEK. THIS HIGH WILL BRING COOL DAYTIME
HIGHS TODAY AND TUESDAY...WITH CHILLY NIGHTS TONIGHT AND TUESDAY
NIGHT. TEMPERATURES WILL BEGIN TO MODERATE ON WEDNESDAY AND REACH
ABOVE NORMAL LEVELS BY THE END OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1006 AM EDT...THE SFC COLD FRONT HAS MOVED SOUTH OF THE FCST
AREA WITH THE PREFRONTAL SCT SHOWERS. SOME SUBSIDENCE IN THE WAKE
OF THE FRONT HAS ALLOWED THE SKIES TO BECOME PARTLY SUNNY OVER THE
ERN CATSKILLS...CAPITAL REGION...UPPER HUDSON VALLEY...AND SRN VT.
THE VISIBLE SATELLITE PICTURE SHOWS THE CLOUDS FILLING BACK IN
NORTH AND WEST OF ALBANY...AS THE UPPER LEVEL TROUGH AXIS CLOSES
IN FROM THE ERN GREAT LAKES REGION/SE ONTARIO. ISOLD-SCT SHOWERS
WILL BE POSSIBLE THIS AFTERNOON...ESPECIALLY OVER THE HIGHER
TERRAIN. MAX TEMPS WERE RAISED A FEW DEGREES INTO THE MID 60S OVER
THE CNTRL PORTION OF THE FCST AREA DUE TO THE SUNSHINE IN THE LATE
MORNING. THE WINDS WILL CONTINUE TO VEER TO THE WEST TO NORTHWEST
DURING THE AFTERNOON. THE LATEST 3-KM HRRR SHOWS THE SHOWERS/SPRINKLES
DECREASING IN COVERAGE BY THE MID PM. FROST/FREEZE HEADLINES
REMAIN UP OUTSIDE THE CAPITAL DISTRICT...MID HUDSON
VALLEY...S-CNTRL TACONICS AND NW CT FOR TONIGHT...AS THE LARGE SFC
RIDGE BUILDS IN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT IS FORECAST TO BE DRY WILL CLOUDS DEPARTING EARLY TONIGHT.
WITH A CHILLY AIRMASS BUILDING INTO THE REGION...ALONG WITH WINDS
BECOMING LIGHT AND CLEARING SKIES...EXPECT TEMPS IN MOST AREAS TO
DROP TO BETWEEN THE UPPER 20S AND MID 30S...WITH UPPER 30S TO AROUND
40 FROM THE CAPITAL DISTRICT TO THE MID HUDSON VALLEY AND EASTWARD
INTO LITCHFIELD COUNTY. FOR THE COLDER AREAS HAVE ISSUED FREEZE
WARNING FOR THE WESTERN AND SOUTHERN ADIRONDACKS INCLUDING SOUTHEAST
WARREN COUNTIES...WITH FROST ADVISORIES FOR THE THE MOHAWK AND
SCHOHARIE VALLEYS...THE EASTERN CATSKILLS...WASHINGTON COUNTY...
NORTHERN SARATOGA COUNTY...EASTERN RENSSELAER COUNTY...SOUTHERN
VERMONT AND BERKSHIRE COUNTY.
THE LARGE HIGH PRESSURE SYSTEM WILL SETTLE OVER THE REGION FOR THE
REMAINDER OF THE SHORT TERM PERIOD AS THE CENTER OF THE HIGH ONLY
SLOWLY DRIFTS TO A POSITION JUST OFF THE EAST COAST BY WEDNESDAY.
CLEAR SKIES AND COOL WEATHER WILL PREVAIL THROUGH TUESDAY NIGHT...
WITH A WARM UP STARTING ON WEDNESDAY AS THE WINDS BECOMING SOUTHERLY
AROUND THE HIGH.
HIGHS TUESDAY WILL BE IN THE UPPER 50S TO MID 60S...LOWS TUESDAY
NIGHT IN THE MID 30S TO AROUND 40. HIGHS WEDNESDAY IN THE UPPER 60S
TO LOWER 70S. SOME FROST IS POSSIBLE AGAIN TUESDAY NIGHT...BUT IT
SHOULD BE LIMITED TO THE ADIRONDACKS AND THE GREEN MOUNTAINS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
IT STILL LOOKS AS IF THE VAST MAJORITY OF THE EXTENDED SHOULD BE DRY
WITH SEASONABLE TEMPERATURES. THE ONLY EXCEPTION WOULD BE SATURDAY
WHEN A COLD FRONT IS FORECAST TO MOVE ON THROUGH.
WEDNESDAY NIGHT INTO THURSDAY...HIGH PRESSURE WILL SLOWLY BE
WEAKENING AS IT MOVES OFFSHORE AT THE SURFACE BUT RIDGING ALOFT WILL
IT ALLOW FOR MODERATING TEMPERATURES AND DRY WEATHER DESPITE AN
INCREASE IN MID LEVEL CLOUDS.
LOWS WEDNESDAY NIGHT WILL BE IN THE 40S WITH HIGHS THURSDAY RANGING
FROM THE UPPER 60S NORTHWEST TO MID 70S ALBANY SOUTHWARD.
THIS RIDGE LOOKS TO HOLD THROUGH FRIDAY NIGHT WITH A WEAK SOUTHERLY
FLOW WHICH WILL BOOST H850 TEMPERATURES TO ABOUT +14C LOCALLY.
LOWS THURSDAY AND FRIDAY NIGHT WILL BE RELATIVELY MILD FOR THE TIME
OF YEAR....50S TO AROUND 60...WITH HIGHS WELL INTO THE 70S...UPPER
70S FROM ALBANY SOUTHWARD.
BY SATURDAY...THE AFOREMENTIONED COLD FRONT IS FORECAST TO MOVE
THROUGH. BOTH THE 00Z GFS AND 00Z ECMWF FORECAST THIS FEATURE TO
MOVE THROUGH DURING THE AFTERNOON. HOWEVER...BOTH MODELS DO NOT
INDICATE A WHOLE LOT OF INSTABILITY WITH ITS PASSAGE. FOR
NOW...BASED ON THE TIME OF YEAR AND LACK OF INSTABILITY...HAVE
DECIDED NOT TO MENTION ANY CHANCE OF THUNDER. LATER RUNS MIGHT
INDICATE MORE INSTABILITY. INCLUDE 40 POPS FOR SATURDAY AND 30 POPS
SATURDAY NIGHT.
HIGHS SATURDAY WILL BE A POINT OR TWO LOWER THAN FRIDAY DUE TO
THICKER CLOUD COVER GENERALLY STILL IN THE 70S.
BY SUNDAY...BOTH THE 00Z GFS AND 00Z ECMWF FORECAST THE FRONT TO
MOVE WELL TO OUR EAST. SOMEWHAT COOLER AIR AND DRIER AIR WILL FOLLOW
ALTHOUGH THIS AIR MASS DOES NOT QUITE AS CHILLY AS THE ONE EARLIER
IN THE PERIOD. H850 TEMPERATURES ARE FORECAST TO DROP TO BETWEEN +6C
NORTH AND +9C SOUTH.
LOWS SATURDAY NIGHT AGAIN WILL BE IN THE 50S BUT HIGHS SUNDAY WILL
RANGE FROM AROUND 60 ACROSS THE ADIRONDACK PARK TO AROUND 70 IN THE
HUDSON VALLEY FROM ALBANY SOUTHWARD.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
A COUPLE OF COLD FRONTS WILL CONTINUE TO CROSS THE TAF SITES...ONE
THIS MORNING AND ANOTHER LATER THIS AFTERNOON. THE FIRST HAS ALREADY
PRODUCED A LINE OF LIGHT SHOWERS AT KGFL...NOW WORKING THROUGH
KALB/KPSF AND SOON TO BE KPOU. THUS FAR...MAINLY VFR CONDITIONS HAVE
ENSUED AND IN THE SHORT TERM WE SEE NO REASON FOR THAT TO CHANGE.
HOWEVER...A SECONDARY COLD FRONT...STILL NORTH OF THE NY/CANADIAN
BORDER WILL SWOOP DOWN ACROSS THE AREA MIDDAY INTO THE AFTERNOON. A
FEW LIGHT SHOWERS COULD ACCOMPANY THIS FRONT. UPSTREAM OBSERVATIONS
SUGGEST WE WILL DEAL WITH MVFR CLOUDS AT THE FRONT NEAR FOR A SHORT
TIME THIS AFTERNOON.
LATER THIS EVENING...LOOK FOR THE SKY TO CLEAR.
OVERNIGHT...CROSSOVER TEMPERATURES LOOK TO BE AROUND 30 WITH LOWS
NOT MUCH HIGHER THAN THAT! FOR NOW...INTRODUCE ONLY MVFR FOG AT
KGFL/KPSF AT 06Z...PATCHY FOG BCFG AT KALB AND SINCE THERE MIGHT
ACTUALLY BE A BREEZE ALL NIGHT...NOTHING AT KPOU.
OUTLOOK...
TUESDAY NIGHT THROUGH THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG
WX.
FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
NO FIRE WEATHER PROBLEMS ARE EXPECTED AT THIS TIME.
A COLD FRONT WILL MOVE THROUGH AND EXIT THE REGION THIS MORNING. IT
WILL PRODUCE SOME SHOWERS THAT MAY LINGER INTO THE AFTERNOON.
ANOTHER LARGE HIGH PRESSURE SYSTEM WILL BUILD IN FROM THE UPPER
GREAT LAKES TONIGHT AND TUESDAY...THEN SETTLE JUST OFF THE EAST
COAST DURING THE MIDDLE AND END OF THE WORK WEEK. THIS HIGH WILL
BRING COOL DAYTIME HIGHS TODAY AND TUESDAY...WITH CHILLY NIGHTS
TONIGHT AND TUESDAY NIGHT. TEMPERATURES WILL BEGIN TO MODERATE ON
WEDNESDAY AND REACH ABOVE NORMAL LEVELS BY THE END OF THE WORK WEEK.
RH VALUES WILL ONLY DROP TO BETWEEN 50 AND 60 PERCENT TODAY...THEN
RISE TO BETWEEN 90 AND 100 PERCENT TONIGHT.
SURFACE WINDS WILL BECOME NORTHERLY TODAY AT AROUND 10 MPH...WITH
SOME GUSTS TO 20 MPH POSSIBLE. THE NORTHERLY WINDS WILL DECREASE TO
5 MPH OR LESS TONIGHT.
&&
.HYDROLOGY...
NO HYDROLOGIC PROBLEMS ARE EXPECTED FOR THE NEXT WEEK. THE COLD
FRONT MOVING THROUGH THIS MORNING WILL PRODUCE ONLY LIGHT AMOUNTS OF
RAINFALL...GENERALLY LESS THAN A QUARTER OF AN INCH...WITH NO IMPACT
ON AREA STREAMS AND RIVERS. THE REST OF THE WORKWEEK IS FORECAST TO
BE DRY.
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...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT TUESDAY FOR
NYZ038>041-043-047-048-051-054-058-063-084.
FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT TUESDAY FOR
NYZ032-033-042-082-083.
MA...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT TUESDAY FOR
MAZ001-025.
VT...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT TUESDAY FOR
VTZ013>015.
&&
$$
SYNOPSIS...GJM/WASULA
NEAR TERM...GJM/WASULA
SHORT TERM...GJM
LONG TERM...HWJIV
AVIATION...HWJIV
FIRE WEATHER...GJM
HYDROLOGY...GJM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
959 AM EDT MON SEP 16 2013
.UPDATE...
SLOWLY WEAKENING SFC HIGH PRESSURE RIDGE WITH AXIS EXTENDING FROM
THE CAROLINAS INTO THE WRN ATLC CONTINUES TO CIRCULATE A LIGHT TO
MODERATE ONSHORE WIND FLOW ACROSS ECFL. WATERVAPOR IMAGERY SHOWS
THE UPPER LEVEL TROUGH EXTENDING FROM THE SERN GOMEX NEWD ACROSS
CTRL FL...BUT GETTING DEFORMED PRETTY BADLY PER 13KM RUC ANLYS
FIELDS. THE RUC ALSO SHOWS STRONGER H25 DIVG HAS SETTLED BACK SWD
AGAIN ACROSS THE SRN THIRD OF FL THE ADJCT STRAITS AND GOMEX. LOCAL
88D MOSAIC SHOWS WIDESPREAD CONVECTION IN THIS VERY MOIST AND DIVGT
AREA. 12Z RAOBS SHOW PWAT VALUES OVER THE CTRL PENINSULA SIMILAR TO
SUN (1.7" - 1.9") WITH A TAD MORE MOISTURE ACROSS SOUTH FL (~2.2").
H50 TEMPS NOT QUITE AS COOL (-7C) OWING TO SOME BUILDING OF THE
MID LEVEL RIDGE OVHD DURG THE LAST H24.
FOR THE REMAINDER OF TODAY...UPPER TROUGH OVHD WILL CONTINUE TO
DEFORM/WEAKEN AS SFC RIDGE TO THE NORTH BREAKS DOWN AHEAD OF AN
APPROACHING COLD FRONT. EXPECT LOCAL PGRAD TO WEAKEN FURTHER WITH
A MAINLY LIGHT ONSHORE FLOW AND SLOWER INLAND PUSH TO ECSB.
EXPECT ANOTHER CONVECTIVELY ACTIVE AFTERNOON...WITH ACTIVE SEA
AND LAKE BREEZE BOUNDARIES ON BOTH SIDES OF THE STATE. CURRENT
GRIDDED/TEXT FCSTS ARE ALREADY ADVERTISING THIS...SO NOSIG CHGS
ARE NEEDED.
&&
&&
.AVIATION (PREV)...EXPECT HIGHER COVERAGE OF LATE MORNING AND
AFTERNOON SCATTERED SHOWERS AND TSRA...ESPECIALLY SOUTH OF A
KMLB-KMCO-KLEE. FOR NOW...HAVE INDICATED VCSH/VCTS IN ALL TAFS.
ISOLD SHRA PSBL ALONG THE COAST FROM KMLB-KSUA TONIGHT WITH VCSH
EXPECTED.
&&
.MARINE...ONSHORE WINDS AROUND 10KT OVER MUCH OF THE MAOR...
HOWEVER STRONGER WINDS (13-17KT) NOTED AT LKWF1/SPGF1 C-MANS...
JUSTIFIES KEEPING WINDS 10-15KT SOUTH OF SEBASTIAN INLET FOR
BOTH THE NEAR SHORE AND OFFSHORE LEGS. SEAS 2-3FT.
&&
FORECASTS/AVIATION...CRISTALDI
IMPACT WX UPDATES/RADAR...SPRATT
&&
.PREV DISCUSSION... /ISSUED 323 AM EDT MON SEP 16 2013/
TONIGHT...LOW LVL ONSHORE FLOW AND DEEP MOISTURE WILL CONTINUE THE
CHANCE FOR ONSHORE MOVING SHOWERS ALONG THE COAST THROUGH THE NIGHT.
EXPECT 20 PCT CHANCE NRN COASTAL AREAS TO 30 PCT S CSTL WHERE
DEEPEST MOISTURE WILL LINGER. LOWS IN THE 70S.
TUE-THU...STRONG ONSHORE FLOW PATTERN FOR THE MIDDLE OF THE WEEK AS
A STRONGER SURFACE HIGH BUILDS OUT OF THE GREAT LAKES ACROSS THE MID
ATLANTIC AND EVENTUALLY OFF THE COAST BY THURSDAY.
DEEPER MOISTURE ASSOCIATED WITH THE TROPICAL WAVE MOVING THROUGH THE
NW CARIBBEAN WILL KEEP THE HIGHEST RAIN CHANCES ACROSS THE TREASURE
COAST...WITH THE BEST RAIN CHANCES ACROSS THE REGION ON TUESDAY AT
40-60 PERCENT BEFORE A SLIGHTLY DRIER AIRMASS FILTERS IN FROM THE
NORTH. HOW MUCH DRIER DIFFERS BETWEEN THE GFS AND ECMWF.
THE RESULTING PRESSURE GRADIENT WILL RESULT IN SEVERAL DAYS OF
BREEZY CONDITIONS...AND A FAST MOVING AND DIFFUSE EAST COAST SEA
BREEZE PUSHING WELL INLAND BY EARLY-MID AFTERNOON. WHILE THIS WILL
SHIFT THE BEST CHANCE FOR CONVECTION TO THE WEST COAST BY EARLY
EVENING...THE SEABREEZE CIRCULATION WILL NOT BE STRONG ENOUGH TO
SHUT OFF THE POSSIBILITY OF ONSHORE MOVING SHOWERS AND STORMS
THROUGH THE DAY.
FRI-MON...ONSHORE FLOW WILL WEAKEN AS THE GRADIENT SLACKENS IN
RESPONSE TO THE HIGH TO THE NORTH WEAKENING AND MOVING FURTHER INTO
THE ATLANTIC. GFS AND ECMWF DIFFER SLIGHTLY AS TO THE DEGREE OF
DRYING IN THE MID LEVELS AND STEERING FLOW...BUT BOTH DO SHOW ENOUGH
TO KEEP POPS AT 20-30 PERCENT FRI AND SAT WITH MUCH WEAKER STEERING.
BY SUNDAY...BOTH MODELS CONTINUE TO SHOW THE DEVELOPMENT OF A WEAK
LOW AROUND THE YUCATAN PENINSULA/SOUTHERN GULF OF MEXICO. THIS
FEATURE WILL GET PICKED UP BY THE NEXT UPPER LEVEL TROUGH PUSHING
OFF THE EAST COAST AND LIFTED OUT TO THE NE ACROSS CUBA/SOUTH
FL/BAHAMAS IN THE MONDAY-TUESDAY TIMEFRAME. REGARDLESS OF HOW THIS
FEATURE DEVELOPS...IT APPEARS MODELS ARE GOING TOWARDS A WETTER
PERIOD SUN-TUES AND HAVE BUMPED UP POPS TO REFLECT THIS.
&&
.MARINE...
EAST WINDS TO 10-15 KNOTS THIS AFTERNOON INTO TONIGHT WITH SEAS 2-3
FT TODAY INCREASING TO 3-4 FT OFFSHORE BY LATE TONIGHT. SCATTERED
SHOWERS AND LIGHTNING STORMS EXPECTED ACROSS THE WATERS INTO TONIGHT.
TUES-FRI...TIGHTENING GRADIENT OVER THE WATERS AS SURFACE HIGH
PUSHES OUT OF GREAT LAKES TOWARDS THE EASTERN SEABOARD THROUGH MID
WEEK. MODERATE EAST-NORTHEAST FLOW AROUND 15KTS EXPECTED
TUES-THURS...WITH OCCASIONAL 15-20KTS POSSIBLE ON TUES. WINDS WILL
WEAKEN SLIGHTLY TO 10-15KTS ON FRI AS THE HIGH MOVES OFF THE COAST
AND WEAKENS.
THE LENGTHENING FETCH AND INCREASING WINDS WILL ELEVATE SEAS TO 4-5
FT BY TUES AFTN...AND UP TO 6 FT OFFSHORE WED THROUGH FRI. BASED ON
THE CURRENT FORECAST...WILL LIKELY NEED A CAUTIONARY STATEMENT (THE
FIRST ONE IN A FEW WEEKS) FOR THIS TIME PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 89 75 89 76 / 40 20 40 20
MCO 92 74 91 73 / 50 20 40 20
MLB 89 77 89 77 / 50 30 50 30
VRB 88 75 90 76 / 60 30 50 30
LEE 91 74 91 74 / 40 20 40 20
SFB 91 75 91 74 / 40 20 40 20
ORL 91 75 91 75 / 50 20 40 20
FPR 88 76 89 75 / 60 30 60 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1005 AM EDT MON SEP 16 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS MORNING AS A COLD FRONT
APPROACHES FROM THE NORTH. THE FRONT WILL CROSS THE AREA TONIGHT
AND STALL JUST SOUTH OF THE REGION ON TUESDAY. THE FRONT WILL
REMAIN JUST SOUTH OF THE AREA THROUGH FRIDAY WITH ANOTHER COLD
FRONT CROSSING THE REGION LATE IN THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL SLIDE OFFSHORE AND AWAY FROM THE AREA THIS
AFTERNOON AS A COLD FRONT CURRENTLY ACROSS THE CENTRAL APPALACHIANS
MOVES TOWARD THE CAROLINAS.
ISENTROPIC LIFT GRADUALLY DIMINISHING ACROSS THE MIDLANDS LATE THIS
MORNING AS LOW LEVEL FLOW BECOMES MORE WESTERLY. BATCH OF SHOWERS
OVER THE SOUTHEAST MIDLANDS EXPECTED TO MOVE EAST OF THE MIDLANDS
AROUND MIDDAY. 12Z RUC MODEL INDICATING A WEAK SHORT WAVE OVER THE
UPSTATE TO CROSS THE MIDLANDS THROUGH EARLY AFTERNOON. AIRMASS IS
PROGGED TO BECOME MODERATELY UNSTABLE THIS AFTERNOON WITH A SEA-BREEZE
BOUNDARY APPROACHING THE MIDLANDS AFTER 20Z. THIS COULD ALLOW MORE
CONVECTION TO DEVELOP LATER THIS AFTERNOON. WILL KEEP BEST CHANCE OF
CONVECTION OVER THE SOUTHEAST MIDLANDS.
THE COLD FRONT WILL MOVE INTO THE AREA TONIGHT BRINGING ANOTHER
CHANCE OF SHOWERS AND THUNDERSTORMS WITH IT. TEMPERATURES THIS
AFTERNOON WILL BE IN THE UPPER 80S WITH OVERNIGHT LOWS IN THE MIDDLE
TO UPPER 60S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
FRONT WILL BE JUST SOUTH OF THE AREA TUESDAY MORNING THEN SLIDE
INTO SOUTHERN GA AND STALL DURING THE AFTERNOON HOURS. THIS WILL
BRING SLIGHTLY DRIER AIR INTO THE MID LEVELS OVER THE
REGION...HOWEVER EASTERLY FLOW IN THE LOW LEVELS WILL KEEP
MOISTURE OVER THE AREA. THIS SCENARIO WILL REMAIN IN PLACE THROUGH
WEDNESDAY NIGHT AS HIGH PRESSURE CENTERED OVER THE NEW ENGLAND
STATES MOVES EASTWARD. EXPECT A CHANCE OF SHOWERS TUESDAY MAINLY
OVER THE CENTRAL MIDLANDS AND CSRA WITH A DRY FORECAST FOR TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. TEMPERATURES THROUGH THE SHORT TERM
WILL BE IN THE LOWER 80S FOR DAYTIME HIGHS WITH UPPER 50S TO LOWER
60S FOR OVERNIGHT LOWS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MODELS HAVE COME INTO BETTER AGREEMENT OVER THE PAST COUPLE OF
RUNS WITH THE MAIN DIFFERENCES SURROUNDING A COLD FRONT EXPECTED
TO ARRIVE LATE IN THE WEEKEND. WEAK FRONTAL BOUNDARY WILL REMAIN
JUST SOUTH OF THE FORECAST AREA THURSDAY THEN BEGIN TRACKING
NORTHWARD AS DEEPENING LOW PRESSURE TRACKS ACROSS THE NORTHERN
PLAINS AND PUSHES A COLD FRONT SOUTHWARD INTO THE SOUTHERN PLAINS.
BY FRIDAY THE REMAINS OF THE FRONT WILL BE ACROSS THE FORECAST
AREA WITH A WELL DEFINED COLD FRONT PUSHING THROUGH THE MID MS
VALLEY. ALTHOUGH MODELS DIFFER ON TIMING OF COLD FRONT INTO THE
MIDLANDS EXPECT ARRIVAL LATE SUNDAY...WITH MODELS INDICATING
POTENTIAL FOR THE FRONT TO STALL JUST SOUTH OF THE AREA.
TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
PATCH OF IFR CLOUDS AFFECTING AGS/DNL EXPECTED TO LIFT TO VFR BY
16Z. VFR TO CONTINUE AT CAE/CUB/OGB FOR THE AFTERNOON WITH SCT/BKN
CLOUDS ABOVE 3000 FEET. LOW CONFIDENCE OF CONVECTION ASSOCIATED
WITH THE LATE AFTERNOON SEA-BREEZE BOUNDARY WILL AFFECT THE TAF
SITES...SO WILL NOT INCLUDE CONVECTION IN TAFS.
A COLD FRONT WILL MOVE ACROSS THE REGION TONIGHT WITH A FEW
SHOWERS AND THUNDERSTORMS...CONFIDENCE LOW ON TIMING BUT A PERIOD
OF MVFR OR LOWER CONDITIONS IS POSSIBLE AFTER 00Z.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1052 AM CDT MON SEP 16 2013
.DISCUSSION...
1050 AM CDT
FOR MORNING UPDATE...
MINOR CHANGES TO GOING FORECAST TO REMOVE MENTION OF LAKE EFFECT
PRECIP THIS MORNING...AND TO TWEAK HOURLY TEMPS AND CLOUD COVER.
SURFACE HIGH PRESSURE OVER THE NORTHERN GREAT LAKES REGION WILL
DRIFT SOUTHEAST THROUGH TONIGHT...IN THE WAKE OF MID-LEVEL SHORT
WAVE PROPAGATING THROUGH THE EASTERN GREAT LAKES AND UPPER OHIO
VALLEY. 12Z RAOB ANALYSIS INDICATES SUBSTANTIAL DRY AIR IN THE
MID/UPPER LEVELS ACROSS THE REGION...WHILE LOW LEVEL MOISTURE WAS
MORE ABUNDANT BENEATH 850MB...WITH CONSIDERABLE CLOUD COVER NOTED
IN SATELLITE IMAGERY OVER LOWER MICHIGAN/INDIANA AND CENTRAL IL.
SUBSIDENCE/RISING HEIGHTS IN THE WAKE OF THE EASTERN GREAT LAKES
SHORT WAVE IS DEPICTED IN FORECAST SOUNDINGS THROUGH GRADUALLY
LOWERING INVERSION...WHICH SHOULD CONTINUE TO THIN/DECREASE CLOUD
COVER ACROSS THE REGION. GOES VISIBLE IMAGERY ALREADY INDICATES
STRATOCUMULUS IS FAIRLY SHALLOW...WITH MODIFIED SOUNDINGS OVER THE
WATER NOT PARTICULARLY FAVORABLE FOR PRECIPITATION WITH STRONG
INVERSION AROUND 3500 FT AGL. EXPECTATION IS THAT STRATOCU WILL
CONTINUE TO THIN OVER THE LAKE AND DOWNSTREAM ACROSS CHICAGO METRO
AREA...THOUGH SOME FLAT CU/STRATOCU DEVELOPMENT WILL OCCUR OVER
LAND AREAS AS TEMPS RISE. THICKEST CLOUD COVER OVER LOWER MICHIGAN
AND NORTHWEST INDIANA WILL BE A LITTLE SLOWER TO THIN/ERODE...BUT
SHOULD ALSO SEE A GRADUAL DOWNWARD TREND IN THICKNESS/COVERAGE.
TEMPS WILL REMAIN A LITTLE COOL EVEN IN SUNNIER AREAS...WITH LOW
LEVEL THERMAL ANALYSIS SUPPORTING TEMPS FROM UPPER 60S/AROUND 70
WELL WEST/SOUTH...AND LOW-MID 60S CLOSER TO THE LAKE WHERE ONSHORE
WINDS WILL KEEP THINGS A BIT COOLER.
RATZER
&&
.PREV DISCUSSION...
307 AM CDT
THE PRIMARY FOCUS OF THE FORECAST WAS ON TIMING CLOUD DISSIPATION
TODAY AND THEN THUNDER CHANCES AND DEGREE OF WARM-UP DURING THE
TUE NIGHT-FRI TIME FRAME.
SYNOPSIS...A GENERAL LONG WAVE TROUGH CONTINUES OVER EASTERN
NORTH AMERICA WITH A RE-ESTABLISHING MID-LEVEL WAVE HAVING
PASSED THROUGH THE GREAT LAKES LAST NIGHT. DESPITE THE SURFACE
WIND SHIFT TO NORTHERLY HAVING HAPPENED LAST EVE...THE TRUE LOW-
LEVEL COLD AIR ADVECTION IS ACTUALLY UNFOLDING EARLY THIS MORNING
ACROSS THE REGION...WITH SEVERAL SITES ESPECIALLY NEAR THE LAKE
GUSTING TO 25 MPH FROM THE NORTHEAST. SATELLITE IR AND 11-3.9
MICRON CHANNELS INDICATE LAKE EFFECT STRUCTURE TO THE CLOUDS FROM
MID-LAKE SSW INTO ADJACENT LAKE COUNTIES OF THE FORECAST AREA.
SCATTERED LIGHT SHOWERS/SPRINKLES HAVE BEEN SEEN ON TDWRS WITHIN
THIS. ELSEWHERE...AREAS OF COLD AIR ADVECTION STRATUS/STRATOCU ARE
NOTED OVER THE REGION. THE SURFACE HIGH IS CENTERED OVER NORTHERN
WI AND THE ARROWHEAD OF MN...WHERE SCATTERED SUB-FREEZING
TEMPERATURES ARE SEEN THIS MORNING.
TODAY...THE SURFACE HIGH WILL BASICALLY MOVE DUE EAST TODAY WITH
A PRESSURE GRADIENT HOLDING ITS OWN OVER THE FORECAST AREA
YIELDING NOT MUCH CHANGE IN WIND ORIENTATION OR SPEED. THIS SHOULD
CONTINUE HIGH WAVES ALONG IL SHORES AND KEEP LAKESIDE TEMPS IN THE
MID 60S OR SO BASED ON OBSERVED AND ESTIMATED WATER TEMPERATURES.
A SCATTERING OF THE SYNOPTIC CLOUDS IS EXPECTED BY LATE MORNING
INTO AFTERNOON...WHILE THE PLUME OF LAKE EFFECT CLOUDS IS LIKELY
TO KEEP SOME PARTS OF THE CHICAGO METRO CLOUDY INTO EARLY
AFTERNOON. THE VARIOUS WRF COLUMN CONDENSATE FORECASTS INDICATE
THIS CHANNEL OF CLOUDS SHIFTING WEST SOME BUT MAINLY HOLDING
TOGETHER THROUGH THE MORNING WHICH SEEM REASONABLE PER FORECAST
SOUNDINGS. AN AMDAR SOUNDING BACK FROM 05Z HAD AN EQUILIBRIUM LEVEL
AROUND 6000 FT AND NOT SEEING MUCH CHANGE AT ALL IN THAT THROUGH
THIS MORNING. SOME LIGHT LAKE EFFECT SHOWERS OR SPRINKLES WILL
PROBABLY HANG IN THERE THROUGH THE MORNING...MAINLY IN LAKE
IL...COOK...AND DUPAGE COUNTIES. CONSIDERING LOCAL CLIMATOLOGY FOR
THE 850MB AND 925MB TEMPERATURES AND THE ANTICIPATED INCREASE IN
SUN BY AFTERNOON...MID TO UPPER 60S IN CHICAGO AND AROUND 70
ELSEWHERE ARE EXPECTED FOR HIGHS.
TUESDAY NIGHT-THURSDAY...AFTER QUIET WEATHER INTO TUESDAY...UPPER
HEIGHTS THEN FURTHER BUILD IN THIS PERIOD AS A RIDGE OVER THE
PLAINS SHIFTS EAST. A LOOSELY DEFINED UPPER LOW OVER EASTERN CO
THIS MORNING /PARTIAL REMNANTS OF THE SIGNIFICANT ONE THAT PRODUCED
RECORD CO FLOODING LAST WEEK/...IS FORECAST TO MOVE ENE AS A SHORT
WAVE UNDER THIS RIDGE. THIS WILL LINE UP WITH SOME BETTER ELEVATED
WARM AIR ADVECTION AND MOIST RETURN LATER TUESDAY NIGHT INTO
WEDNESDAY. GUIDANCE STILL HAS SOME NOTABLE DISCREPANCIES IN
EVOLUTION OF ANY CONVECTION TUE NIGHT INTO WED MORNING...BUT
THICKNESSES AND MOISTURE TRANSPORT FIELDS WOULD POTENTIALLY
SUPPORT FADING CONVECTION MOVING EAST TO SOUTHEAST INTO THE
FORECAST AREA IF SOME CAN INITIALIZE ON THE LLJ TO THE WEST. AFTER
THAT...ANY UPPER FOCUS CONTINUES TO LOOK ILL-DEFINED AS THE
FORECAST AREA LOOKS TO BE IN A WARM SECTOR BY THURSDAY. WHILE
MODELS ADVERTISE QPF WEDNESDAY AFTERNOON-THURSDAY AND CANNOT RULE
OUT SOME SCATTERED CONVECTION...IT WOULD SEEM THEY REMAIN OVERDONE
AND HAVE GONE BELOW A GUIDANCE BLENDED POP. FOR TEMPS...WEDNESDAY
IS A CHALLENGE BASED ON POTENTIAL PRECIP...AND HAVE NOT SWAYED
MUCH FROM THE GOING FORECAST. THE WARMEST READINGS LOOK TO BE ON
THURSDAY WITH MODEST CONFIDENCE OF 80 PLUS OVER MUCH OF THE CWA
GIVEN SUPPORT OF LOCAL CLIMATOLOGY AND BIAS-CORRECTED
GUIDANCE...WHICH HAS WORKED WELL IN THE WARM STRETCHES DURING THE
PAST MONTH.
THURSDAY NIGHT-FRIDAY...LONG RANGE GUIDANCE IS IN GOOD AGREEMENT
OF AN UPPER WAVE MOVING ALONG THE CANADIAN BORDER IN THIS PERIOD
WITH AN ASSOCIATED SURFACE COLD FRONT MOVING THROUGH THE FORECAST
AREA. FORCING FOR CONVECTIVE PRECIP IS THERE ON ALL GUIDANCE BUT
CAN LIKELY EXPECT TO SEE SOME TIMING SHIFTS. HAVE LIKELY POPS
AREAWIDE THU NIGHT FOR NOW. GFS PWAT AND MOISTURE TRANSPORT
PROJECTIONS DO INDICATE THAT SOME OF THE DEEP MOISTURE FROM TROPICAL
STORM INGRID GETS WRAPPED INTO PART OF THE SYNOPTIC WARM
SECTOR...THOUGH IT DOES NOT APPEAR TO TRAVERSE THIS FAR NORTH.
SOMETHING CERTAINLY TO KEEP AN EYE ON THOUGH FOR MORE EFFICIENT
RAINFALL PRODUCTION.
BEYOND...WITH THE JET STREAM TO THE NORTH AND THE PATTERN
REMAINING PROGRESSIVE...TEMPERATURES LOOK TO BE AROUND NORMAL OR
JUST A TAD BELOW NEXT WEEKEND. ALSO GIVEN THE CURRENT TIMING OF
SYSTEMS IT WOULD LOOK TO BE DRY AS WELL.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* HIGH END MVFR CIGS POSSIBLE THROUGH LATE MORNING.
* WIND DIRECTION VARYING FROM NNW TO NNE OVER THE NEXT 1-2 HOURS
BEFORE A MORE PREVAILING NE DIRECTION SETS IN FOR THE REMAINDER
OF THE DAY...WITH GUSTS TO THE UPPER TEENS.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
A SECONDARY SURGE OF COOLER AIR CONTINUES TO PUSH DOWN THE
LAKE. A WEAK CONVERGENCE BAND HAS SET UP OVER NERN IL...WITH WINDS
NNWLY AT ORD AND NNELY AT MDW AND THE OTHER TAF SITES. EXPECT THAT
THIS BAND SHOULD WEAKEN THROUGH THE MORNING AND WINDS WILL BECOME
PREVAILING NNELY...VEERING NELY BY EARLY AFTERNOON. THIS
CONVERGENCE BAND AND RELATIVELY COOLER AIR OVER WARMER LAKE WATER
HAS SET UP A WEAK LAKE EFFECT REGIME...THOUGH LOW INVERSION
HEIGHTS AND WEAK INSTABILITY SHOULD LIMIT THE LAKE EFFECT TO MVFR
CIGS. AN ISOLD LIGHT SHOWER IS NOT OUT OF THE QUESTION...BUT IF
ANY DEVELOP THEY WOULD BE WEAK AND FLEETING. BY LATE MORNING OR
EARLY AFTERNOON...DRIER AIR FILTERING OVER THE AREA AS THE HIGH
PRESSURE CONTINUES TO SPREAD OVER THE REGION WILL ALLOW FOR SKIES
TO CLEAR OUT AS WINDS GRADUALLY VEER MORE ELY BY THIS EVENING AND
THEN SELY OVERNIGHT TONIGHT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE WITH CIG TRENDS.
* HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. CHANCE SHRA LATE.
WEDNESDAY AND THURSDAY...CHANCE SHRA/TSRA...OTHERWISE VFR.
FRIDAY...CHANCE SHRA EARLY. COLD FRONTAL PASSAGE EARLY WITH SHARP
WIND DIRECTION SHIFT FROM SLY TO NWLY.
FRIDAY NIGHT THROUGH SUNDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
307 AM CDT
STRONG HIGH PRESSURE CONTINUES TO SPREAD INTO THE UPPER GREAT
LAKES AS THE COLD FRONT PUSHES INTO THE OHIO VALLEY. A SECONDARY
SURGE OF COOLER AIR SPREADING DOWN THE LAKE HAS HELPED INCREASE
WINDS TO AROUND 30KT THROUGH THE EARLY MORNING HOURS. AS THE THE
CENTER OF THE HIGH SLIDES TO THE SOUTHEAST INTO THE EASTERN GREAT
LAKES MONDAY NIGHT...THE GRADIENT WILL RELAX...ALLOWING WIND
SPEEDS TO DECREASE AND DIRECTION TO VEER FROM GENERALLY NORTHERLY
TODAY TO SOUTHERLY BY TUESDAY MORNING. THE SOUTH WINDS WILL
PERSIST THROUGH THURSDAY AND THEN VEER MORE SOUTHWESTERLY BY
FRIDAY AS DEEP LOW PRESSURE MOVES INTO SOUTH CENTRAL CANADA AND A
STRONG COLD FRONT APPROACHES THE UPPER MISSISSIPPI VALLEY.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 PM TUESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001 UNTIL 4 PM TUESDAY.
BEACH HAZARDS STATEMENT...INZ002 UNTIL 10 PM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 4 PM
TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 11 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
1000 AM CDT Mon Sep 16 2013
.DISCUSSION...
ISSUED 1000 AM CDT Mon Sep 16 2013
Stratocumulus deck continues to thin out over a good part of
central Illinois this morning, with the northern edge basically
along I-74 from Galesburg to near Bloomington. However, some
higher clouds evident in satellite imagery spreading eastward over
the state. Cu-rule off the RAP model continues to show some
erosion of the lower cloud deck as drier air advects in from the
northeast.
Have sent some updated grids to bump up the winds and adjust the
dew points a bit. Temperatures still look good. The changes do not
require a change to the zone forecasts at this point.
Geelhart
&&
.AVIATION...
ISSUED 655 AM CDT Mon Sep 16 2013
Broken to overcast stratus/stratocumulus clouds with bases 500-1.5k ft
over central IL terminals early this morning (BMI at 300 ft) to
gradually lift to MVFR ceiling later this morning. Low clouds
should then scattered out during midday, occurring first along
northern airports along I-74 with broken cirrus clouds today. Some
MVFR vsbys of 3-5 miles over eastern IL at times especially at BMI
will lift to VFR vsbys by mid morning 14-15Z. Fair skies expected
after sunset tonight with scattered cirrus clouds and patchy light
fog with MVFR vsbys possible over eastern IL after 08-09Z. Northeast
winds around 10 kts with few gusts around 15 kts this morning to
diminish between 5-10 kts during the mid/late afternoon and veer ENE
around 5 kts tonight. Cold front near the Ohio River and MO/AR
border to keep convection south of central IL next 24 hours. 1030
MB Canadian high pressure around Lake Superior to drift southeast
across the Great Lakes region the next 24 hours and bring fair
weather to central IL.
07
&&
.PREV DISCUSSION...
ISSUED 257 AM CDT Mon Sep 16 2013
Cold front has moved through the FA this morning...stretching
along the Ohio River Valley while cooler air moves into place for
much of the Midwest. Northeasterly winds have settled in as a
surface high pressure, centered in northern MN, builds back into
the Midwest. Persistent upper level ridging over the Rockies and
the high plains providing a source of warming later in the
forecast...but for the next couple of days the temperatures are
rather cool. Into the remainder of the week, the forecast becomes
problematic almost immediately with a return of pops and a lack of
consistency in operational models. Low chance pops dominate
between a shortwave moving through Tuesday night/Wednesday and an
actual front on Thu night/Friday. On the other side of Friday
night...next weekend dries back out. Though breaks in the rain is
expected between Wednesday afternoon and Thursday night, models are
filling the gap with low pops.
SHORT TERM...Today and tomorrow...
Slow drying out behind the boundary with cooler temps expected
today. Clearing of clouds slowly as high pressure builds into the
region. Some clearing to the NW will work into the region...though
plenty of remnant clouds will move in from the SW and convection
behind the front in MO. Variable clouds through the day will
dissolve into the evening hours, clearing out and assisting
efficient radiational cooling and a temp drop into the 50s.
Tomorrow the winds get a small southerly component and the general
moderation of the air mass begins and temperatures start to climb a
couple degrees. That being said, clouds should be on the increase
so cooling tomorrow night should be impeded by the increasing
cloud cover. Pops return to forecast tomorrow afternoon in the
east and into the overnight, although concern for speed of onset of
QPF in general with the wave moving much faster in 00Z runs.
LONG TERM...Wednesday through Sunday...
Temperatures moderating somewhat by Wednesday due to a eastward
trending of the western mid level thermal ridge. Expect some
variability in the guidance as the portrayal of the next system
becomes clearer, right now being torn between the warmth under the
ridge and the threat of advancing rain. Pops move in Tues night
and continue through Friday with a lack of consistency for GFS and
ECMWF, as a result muddying the AllBlend. In addition, models
attempting a slow progression of initial wave and create an
interaction between remnant energy aloft and developing boundary
as another upper trof pushes into the region. Both ECMWF and GFS
fill the gap with pops across the board, so the AllBlend follows
suit. GFS and ECMWF are alternating being the most aggressive with
the strength and depth of the wave...and the QPF as well. For now,
the forecast remains rather diffuse and generous with the pops.
Best chances for precipitation beyond Wednesday looks to be in the
Thursday night/Friday time frame, associated with a cold front as
an aggressive trof digs in over the upper Midwest.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
851 AM EDT MON SEP 16 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA THIS EVENING...UNTIL
SO LOOK FOR CLOUDS TO HANG AROUND. DRY AND SEASONAL WEATHER TAKES
HOLD THROUGH MID WEEK. A COLD FRONT WILL CROSS LATER THIS WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RAIN IS ALMOST OUT OF THE AREA AT WHILE COLD FRONT IS CROSSING THE
SPINE OF THE APPALACHIANS. THERE WILL BE A BREAK IN PCPN FOR THE
ENTIRE AREA THIS MRNG...THEN ISOLD SHOWERS ARE POSSIBLE IN THE
I-80 AREA THIS AFTN. FARTHER S...DO NOT EXPECT ANY MEASURABLE
QPF. RUC SOUNDINGS ILLUSTRATE MARGINAL INSTABILITY GIVEN LAKE
DELTA TS. INVERSION HEIGHT LOWERS TO 4-5KFT DURING THE DAY
OFFSETTING ANY LAKE INDUCED INSTABILITY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE SHRTWV IS PROGGED TO EXIT THE RGN THIS EVE. STILL SOME QN ON
HOW LONG THE STRATOCU WILL REMAIN ACRS THE AREA. KEPT MCLDY SKIES
INTO THE EVE WITH A GRDL CLRG TREND OVRNGT AS THE FLOW BECOMES
NERLY AND SBSDNC INCRS WITH BLDG HIGH PRES. THE HIGH WL SHIFT EWD
WED WRM AIR ADVCTN BRINGING A GRDL INCRS IN CLDS LT IN THE DAY.
SHWR/TSTM CHCS WL INCR WED NGT AND THU AS A SHRTWV MOVES ACRS THE
GT LKS/OH VLY RGN. EXP LOWS TNGT AND TUE NGT FM UPR 30S/NR 40 N TO
MD 40S S...WHICH SHOULD PRECLUDE ANY FROST MENTION IN THE FCST.
EXP TEMPS TO MODERATE TO NR OR ABV SEASONAL AVGS BY MD WK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
RAIN CHCS WL INCRS DURING THE LATTER HALF OF THE WEEK AS MDLS ARE
IN AGRMNT IN SCENARIO OF A DEEPENING TROF WITH ITS ADVN ACRS THE
GREAT LAKES. CURRENT GFS AND ECMWF TIMING SUGGESTS CDFNT/UPR TROF
AXIS PASSAGE FOR SATURDAY...HENCE THE DRYING TREND DEPICTED FOR
THE START OF THE NEW WEEK.
WARM ADVCTN IN ADVN OF THAT TROF WL LIKELY SPPRT TEMPS AOA THE
SEASONAL AVERAGES UNTIL FRONTAL PASSAGE. WPC GUIDANCE GENL DEPICTS
THIS AND WAS UTILIZED WITH MINIMAL VARIATION.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
A CDFNT WL COMPLETE PASSAGE ACRS THE UPR OH REGION THIS MRNG
ACCOMPANIED BY A BROAD SWATH OF LOW AND MID LVL CLDINESS WITH RESIDUAL
LGT SHWRS. MOIST BNDRY LYR FM LAST NGTS RAIN WL SPPRT ISOLD AREAS
OF IFR VSBY AND ST...WHICH WL MIX OUT RAPIDLY AFTR DAYBREAK.
MVFR STRATOCU IS EXPECTED TO PERSIST THROUGH THE MRNG...BUT DRY
ADVCTN...SBSDNC...AND DVLPG NNE COMPONENT TO THE SFC WIND SHOULD
SPPRT VFR BY AFTN. BLDG HIGH PRES WL THEN MAINTAIN THAT CONDITION
THROUGH TNGT.
.OUTLOOK.../TUESDAY THROUGH FRIDAY/...
SHWRS WITH A THURSDAY WARM FRONT WL BRING THE NXT CHC FOR GENL RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...98
NEAR TERM...98
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
737 AM EDT MON SEP 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 513 AM EDT MON SEP 16 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE WESTERN GREAT LAKES BETWEEN A RIDGE OVER THE PLAINS AND A
TROUGH OVER ERN CANADA. STRONG 700-300 MB QVECTOR DIV IN THE WAKE OF
A SHORTWAVE TROUGH MOVING INTO NEW ENGLAND HAS BROUGHT CLEARING SKIES
OVER MOST OF THE REGION AS A 1030 MB SFC HIGH OVER NW ONTARIO AND NRN
MN BUILDS INTO UPPER MI. HOWEVER...LINGERING NE 10 TO 15 KNOT WINDS
OVER ERN LAKE SUPERIOR ALONG WITH 850 MB TEMPS NEAR 0C HAS GENERATED
LAKE CLOUDS THAT HAVE SPREAD INTO PORTIONS OF NRN UPPER MI. THIS
ALONG WITH CONTINUED LIGHT NE WINDS HAVE KEPT TEMPS FROM DROPPING OFF
AS MUCH OVER THE NORTH AND EAST COMPARED TO INLAND LOCATIONS OVER THE
WEST WHERE READINGS INTO THE LOWER 30S WERE COMMON.
TODAY...EXPECT DAYTIME HEATING/MIXING AND CONTINUED DRY ADVECTION TO
HELP SCOUR OUT THE EARLY MORNING CLOUDS WITH MOSTLY SUNNY CONDITIONS
THEN PREVAILING. THE ABUNDANT SUNSHINE WILL HELP PUSH TEMPS TO NEAR
60 THIS AFTERNOON.
TONIGHT...THE SFC HIGH CENTERED JUST EAST OF THE FCST AREA WILL
CONTINUE TO DOMINATE THE REGION WITH A DRY AIRMASS IN PLACE. ANOTHER
NIGHT WITH VERY FAVORABLE RADIATIONAL COOLING CONDITIONS WILL AGAIN
RESULT IN AREAS OF FROST. THE LOWEST READINGS ARE EXPECTED INTO THE
CNTRL AND ERN PORTION OF THE CWA WHERE THE WINDS WILL BE LIGHTEST.
SOME INCREASE IN SRLY WINDS OVER THE FAR WEST AND DOWNSLOPE
LOCATIONS NEAR LAKE SUPERIOR FROM DEVELOPING LAND BREEZE
SHOULD KEEP TEMPS CLOSER TO 40. SINCE THERE IS ALREADY AN ONGOING
FROST ADVISORY...A NEW ONE FOR TONIGHT WAS NOT POSTED AT THIS TIME TO
AVOID CONFUSION EVEN THOUGH ANOTHER ADVISORY FOR TONIGHT WILL LIKELY
BE NEEDED.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 327 AM EDT MON SEP 16 2013
VERY CONVOLUTED FORECAST FOR MID TO LATE WEEK AS MODELS STRUGGLE WITH
AGREEMENT BETWEEN MODELS AND RUN TO RUN CONTINUITY WITH A SYSTEM
PROGGED TO MOVE ACROSS THE NRN CONUS. THE SHORTWAVE THAT THE SYSTEM
WILL EVOLVE FROM IS CURRENTLY ANALYZED BY MODELS TO BE ABOUT 15
DEGREES LONGITUDE WEST OF THE ATLANTIC COAST OF WA/OR...SO THERE ARE
NOT ANY GOOD OBSERVATIONS OF THE MORE SUBTLE SHORTWAVE ENERGY...OR
EVEN THE DEEPER UPPER LOW/TROUGH THAT IT IS ROTATING AROUND. THE
POOR DATA FOR INITIALIZATION EXPLAINS...AT LEAST PARTIALLY...THE
MODEL DISAGREEMENT AND DISCONTINUITY...ESPECIALLY AFTER ADDITIONAL
ENERGY IS ADDED OVER THE NRN PLAINS THAT MAY CAUSE A RAPID DEEPENING
OF THE SYSTEM. THE SYSTEM AND ADDITIONAL SHORTWAVE ENERGY DOES NOT
MOVE FULLY INTO THE UPPER AIR OBSERVATION NETWORK UNTIL LATE
TUE/EARLY WED...SO IMPROVEMENTS TO CONFIDENCE MAY NOT HAPPEN UNTIL
THAT TIME. BASICALLY...THE SYSTEM JUST HAS THE POTENTIAL TO BRING
RAIN...COLDER TEMPS AND WINDS...BUT IT IS THE FIRST OF THE MORE
SIGNIFICANT DEEPER SYSTEMS OF THE SEASON.
BACK TO A MORE ORGANIZED DISCUSSION STARTING AT 12Z TUE...AN UPPER
LEVEL RIDGE WILL BE OVER THE CWA WITH A SHORTWAVE OVER THE CENTRAL
PLAINS. A SFC HIGH WILL BE CENTERED OVER THE LOWER GREAT
LAKES...WITH THE CWA BETWEEN THE HIGH AND A SFC LOW OVER CENTRAL
SASKATCHEWAN. NO PRECIP IS SHOWN BY MODELS TUE AND TUE NIGHT AS THEY
NOW KEEP THE SHORTWAVE WELL S OF THE CWA. WILL LOWER POPS FOR THIS
PERIOD. LOW LEVEL SW FLOW WILL INCREASE TUE AND TUE NIGHT BETWEEN
THE HIGH TO THE E AND LOW TO THE W...WITH INCREASING LOW LEVEL TEMPS
AS WELL.
FOR WED...MODELS HAVE THE AFOREMENTIONED DEEPER LOW PRESSURE SYSTEM
DEEPENING OVER THE DAKOTAS. SOME MODELS ALSO SHOW SHORTWAVE ENERGY
MOVE THROUGH THE CWA WED...AND CAN NOT RULE THIS OUT AT THIS TIME SO
WILL KEEP AT LEAST SLIGHT CHANCE POPS IN THE FORECAST. LOW LEVEL
TEMPS SHOULD INCREASE AGAIN ON WED...BUT HIGH TEMPS SHOULD BE
SIMILAR TO TUE /UPPER 60S TO AROUND 70/ DUE TO INCREASED CLOUD COVER.
WED NIGHT THROUGH SAT AND PARTIALLY INTO SUN IS WHEN MODEL SOLUTIONS
DIVERGE AND CONFIDENCE IS SIGNIFICANTLY REDUCED. MODEL SPREAD
INCLUDES THE 12Z/15 GEM AND 00Z/16 GFS IN BRINGING THE CLOSED OFF
LOW ACROSS ONTARIO TO JAMES BAY BY FRI NIGHT...DRAGGING THE COLD
FRONT ACROSS THE CWA LATE THU UNTIL FRI. THE 12Z/15 ECMWF IS FARTHER
S...DEEPENING THE LOW AS IT MOVES ACROSS THE CWA FRI NIGHT INTO SAT.
THIS REALLY THROWS OFF WINDS...TEMPS AND PRECIP AND OTHER ASSOCIATED
FIELDS. WILL GO WITH A CONSENSUS OF MODEL GUIDANCE AS IT IS
DIFFICULT AND FUTILE TO CHOOSE ANY ONE SOLUTION AT THIS TIME.
MODELS DO COME BACK INTO BETTER AGREEMENT SUN /ESPECIALLY LATER ON
SUN/ WITH BRINGING AN UPPER RIDGE AXIS TO NEAR THE CWA AND A SFC
RIDGE OVER THE CWA BY 00Z MON. AGAIN...WILL STICK WITH A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 736 AM EDT MON SEP 16 2013
SCT-BKN NE FLOW LAKE CLOUDS JUST ABOVE 3K FT WILL BE POSSIBLE
EARLY AT SAW TIL DAYTIME MIXING INCREASES. OTHERWISE...WITH HIGH
PRES BUILDING INTO THE REGION...VFR CONDITIONS ARE EXPECTED THROUGH
THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 513 AM EDT MON SEP 16 2013
WITH SFC HIGH PRES BUILD INTO THE AREA TODAY AND LINGERING INTO
TONIGHT...WINDS WILL REMAIN AT OR BELOW 15 KNOTS. AS THE HIGH SHIFTS
TO THE EAST...SRLY WINDS UP TO 20 KNOTS ARE EXPECTED FROM TUE INTO
WED. WINDS SHOULD THEN REMAIN BELOW 20 KNOTS UNTIL FRI WHEN A TROUGH
MOVING THROUGH THE REGION BRINGS SW TO W WINDS TO AROUND 25 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 9 AM EDT /8 AM CDT/ THIS MORNING FOR
MIZ002>005-009>011-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
920 AM EDT MON SEP 16 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTH LATE THIS AFTERNOON...
THEN PUSH SOUTH THROUGH THE AREA TONIGHT. CANADIAN HIGH PRESSURE
WILL BUILD INTO THE REGION ON TUESDAY AND PERSIST THROUGH WEDNESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 920 AM MONDAY...
UPDATE THROUGH REST OF TODAY: THE ISOLATED BAND OF SHALLOW BUT VERY
HEAVY RAIN SHOWERS WHICH PASSED THROUGH THE TRIANGLE EARLY THIS
MORNING IS MOVING QUICKLY EASTWARD THROUGH THE CENTRAL COASTAL
PLAIN. THESE SHOWERS APPEAR TO HAVE BEEN DRIVEN BY INTENSE LOW LEVEL
MOIST UPGLIDE (NOTED ON RAP OUTPUT AT 300K) ALONG A PROMINENT TONGUE
OF HIGH SURFACE THETA-E NOSING UP THROUGH THE ERN SANDHILLS TOWARD
RALEIGH/WILSON/GOLDSBORO... POSSIBLY AUGMENTED BY A FEW DOZEN J/KG
OF CAPE OBSERVED ON RAP PROXIMITY SOUNDINGS. THIS WAS AN INTERESTING
OCCURRENCE AS IT WAS DRIVEN BY SUBTLE AND SMALL YET STRONG FORCING
FEATURES... CONFINED TO THE LOWEST 2.5 KM WITH VERY DRY/STABLE AIR
ABOVE... THAT WERE POORLY HANDLED BY LAST NIGHT`S COMPUTER MODEL
GUIDANCE. A FEW LIGHTER AND MORE PATCHY SHOWERS TRAILING THE HEAVIER
RAINBAND ARE EXPECTED TO ALSO SHIFT EAST IN THE NEXT FEW HOURS
ACCORDING TO THE LATEST HRRR. WILL CARRY A MENTION OF ISOLATED
SHOWERS FOR THE REST OF THE MORNING EAST OF RDU... THEN EXPECT A
BRIEF LULL IN ANY PRECIP CHANCES THROUGH EARLY AFTERNOON AS DAYTIME
HEATING HELPS TO MIX OUT THE VERY MOIST LOW LEVELS OVER MUCH OF
CENTRAL NC... WHILE DRIER DEW POINTS AND LOWER 925-850 MB THETA-E
FILTER IN FROM THE WEST AHEAD OF THE COLD FRONT APPROACHING FROM THE
NORTH. WE SHOULD SEE ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS
PUSHING IN FROM THE NORTH VERY LATE THIS AFTERNOON INTO EARLY
EVENING JUST AHEAD OF THE FRONT... FORCED BY INCREASING MASS
CONVERGENCE IN THE LOWER LEVELS AND INCREASING UPPER DIVERGENCE IN
THE RIGHT ENTRANCE REGION OF THE STRENGTHENING JET FOCUSED IN THE
UPPER ST LAWRENCE VALLEY. MID LEVEL MOISTURE IS EXPECTED TO RISE
QUITE A BIT LATER THIS AFTERNOON WITH PW REBOUNDING ABOVE 1.4
INCHES... SO THESE LATE-DAY SHOWERS SHOULD BE DEEPER... ALTHOUGH WE
SHOULD STILL ONLY SEE 100 J/KG OR LESS OF MLCAPE... PERHAPS NEAR 200
J/KG IN THE EXTREME SE WHERE A MENTION OF THUNDER WILL BE RETAINED.
TEMPS ARE TRICKY AND WILL DEPEND ON THE BEHAVIOR OF THE STRATOCU
EAST OF THE TRIAD. THESE CLOUDS LOOK TO BE MOVING STEADILY EASTWARD
HOWEVER WITH SOME GOOD BREAKS IN THE CLOUDS... SO WITH AN
ABOVE-NORMAL 12Z GSO THICKNESS OF 1394 M... STILL EXPECT HIGHS OF
83-87 WITH MOSTLY CLOUDY SKIES BECOMING PARTLY CLOUDY. -GIH
TONIGHT:
WILL KEEP A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ALONG AND
EAST OF HWY 1 THIS EVE WHERE THE RELATIVE BEST LOW-LEVEL MOISTURE
AND DESTABILIZATION IS EXPECTED...WITH ANY POTENTIAL FOR THUNDER
CONFINED TO THE SANDHILLS/SE COASTAL PLAIN. EXPECT CHANCES ENDING
FROM NW-SE OR NNW-SSE BY MIDNIGHT AS A DRIER /MORE STABLE/ AIRMASS
ADVECTS INTO THE REGION IN THE WAKE OF THE FRONT. LOWS TONIGHT WILL
BE DRIVEN BY COLD ADVECTION AND WILL DEPEND ON THE PRECISE TIMING OF
THE COLD FRONTAL PASSAGE...MEANING FCST LOW TEMPS COULD EASILY BUST
BY SEVERAL DEGREES. BASED ON THE LATEST FROPA TIMING (21-03Z N-S)...
EXPECT LOWS RANGING FROM THE UPPER 50S NEAR THE VA BORDER TO THE
LOWER/MID 60S NEAR THE SC BORDER. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
HIGH PRESSURE WILL BUILD INTO THE MID-ATLANTIC ON TUE...WITH A
PRONOUNCED SFC RIDGE AIS EXTENDING S/SW INTO CENTRAL NC. GIVEN A
DRY/STABLE AIRMASS IN PLACE IN THE WAKE OF THE COLD FRONT...EXPECT
CLEARING SKIES WITH HIGHS IN THE MID/UPPER 70S TO NEAR 80F...WARMEST
SOUTH AND COOLEST NORTH. LOWS TUE NIGHT RANGING FROM ~50F AT THE VA
BORDER TO THE MID/UPPER 50S SOUTH. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...
CHILLY CONTINENTAL POLAR HIGH PRESSURE CENTERED OVER SOUTHERN
ONTARIO THIS MORNING WILL MODIFY AS IT BUILDS TO THE NORTHERN MIDDLE
ATLANTIC STATES BY MID WEEK. FORECAST GUIDANCE SUGGESTS THE RIDGE
AXIS WILL THEN CONTINUE TO EXTEND SOUTHWESTWARD ALONG AND EVENTUALLY
JUST OFFSHORE THE EAST COAST...SUPPORTED BY LONGWAVE RIDGING ALOFT
DOWNSTREAM OF A SERIES OF STRONG UPPER LOWS FORECAST TO MIGRATE
EASTWARD ALONG THE US/CANADIAN BORDER IN PROGRESSIVE LATE SUMMER
FLOW. THE FIRST OF THESE UPPER LOWS WILL PROPEL A COLD FRONT INTO
THE EASTERN US THIS WEEKEND...WITH FAVORED TIMING IN CENTRAL NC
DURING THE SECOND HALF OF THE WEEKEND - WITH AVERAGE TO
SLIGHTLY ABOVE FORECAST CONFIDENCE DUE TO TYPICAL TROUGH ALOFT
TIMING...AMPLITUDE...AND TILT DIFFERENCES DEPICTED BY THE MEDIUM
RANGE NWP GUIDANCE AT THAT TIME RANGE.
RETURN FLOW AROUND THE SURFACE RIDGE WILL PROMOTE A VEERING OF THE
LOW LEVEL FLOW FROM NE-ENE DURING THE MIDDLE OF THE WEEK - WITH SCT
TO BKN STRATOCUMULUS FROM MOISTURE TRAPPED BENEATH A SUBSIDENCE
INVERSION WED-WED NIGHT - TO A WARMING S-SW COMPONENT BY FRI-SAT.
THE ASSOCIATED WARMING WILL SEND TEMPERATURES BACK INTO THE LOWER TO
MIDDLE 80S AHEAD OF THE AFOREMENTIONED APPROACHING COLD FRONT...
WARMEST FRI-SAT. LOWS WILL MODIFY AS WELL...FROM COOLEST READINGS IN
THE 50S THU MORNING...TO MIDDLE 60S SAT NIGHT.
PRECIPITATION CHANCES WILL BE TIED TO THE PASSAGE OF THE FRONT
THROUGH WEAK WARM SECTOR INSTABILITY. HAVE ACCORDINGLY REMOVED
PRECIPITATION CHANCES FROM FRI AND INSTEAD CONFINED A LOW CHANCE OF
SHOWERS AND STORMS TO THE FAVORED FRONTAL PASSAGE TIMING LATE
SAT-SUN.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 640 AM MONDAY...
06Z TAF PERIOD:
IFR CEILINGS AND ISOLD SHOWER ACTIVITY CAN BE EXPECTED ACROSS THE
PIEDMONT (PRIMARILY RDU TERMINAL) THROUGH 16Z...WITH SUB-VFR FOG
AND/OR CEILINGS AND ISOLD SHOWER ACTIVITY POSSIBLE AT THE EASTERN
TERMINALS IN THE SAME TIME FRAME. ANY SUB-VFR CEILINGS ARE EXPECTED
TO SCATTER OUT AND LIFT TO VFR BY LATE MORNING TO EARLY AFTERNOON
(15-18Z). A BACK DOOR COLD FRONT WILL SURGE SOUTHWARD THROUGH
CENTRAL NC THIS EVENING INTO TONIGHT AS STRONG CANADIAN HIGH
PRESSURE BUILDS INTO THE MID-ATLANTIC. EXPECT A FRONTAL PASSAGE
SIMILAR TO LAST FRI/SAT...I.E. VFR ASIDE FROM A SMALL CHANCE FOR
ISOLD CONVECTION AT THE FAY/RWI TERMINALS AND A SHORT PERIOD OF
BREEZY NORTHEAST WINDS IN THE WAKE OF THE FRONT MON NIGHT AND TUE
MORNING.
LOOKING AHEAD:
EXPECT DRY/VFR CONDITIONS ASSOCIATED WITH HIGH PRESSURE TO
PREVAIL THROUGH MID-WEEK. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...HARTFIELD/VINCENT
SHORT TERM...VINCENT
LONG TERM...MWS
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
633 AM CDT MON SEP 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT MON SEP 16 2013
LOW LEVEL MOISTURE PATTERN IS A BIT CHAOTIC EARLY THIS MORNING
WITH AREAS OF LOW CLOUDS...BUT NOT LOW STRATUS...DEVELOPING AND
MOVING ACROSS THE AREA. THIS IS HAPPENING EVEN AS THE MORE SOLID
DECK HAS BEEN DECREASING FAR SOUTH OVER THE MISSOURI RIVER AREA.
SHORT TERM MODELS ESPECIALLY THE HRRR SEEM TO HAVE A HANDLE ON
THIS. THAT MODEL SHOWS THIS PATTERN CONTINUING THEN THE CLOUDS
DECREASING FAIRLY QUICKLY AROUND NOON. WILL GO WITH THIS IDEA AS
THE AIR GETS HEATED AND MIXED OUT. THAT SHOULD MAKE SKIES MOSTLY
SUNNY BY THE AFTERNOON. A SPLIT BETWEEN GUIDANCE AND CONTINUITY
LOOKS GOOD ON HIGH TEMPERATURES TODAY. TONIGHT THEN STARTS THE
WARM ADVECTION PATTERN OVER A DEEP RANGE OF LEVELS AND THE
ACCOMPANYING INCREASE IN CLOUDS FROM THE SOUTH...ESPECIALLY OVER
THE EASTERN PART OF THE AREA. LOW TEMPERATURES TONIGHT WILL NOT BE
AS COOL AS CURRENT VALUES. THE START OF AN INCREASE IN INSTABILITY
DOES NOT SEEM ENOUGH TO SUPPORT ANY SHOWERS OR STORMS THROUGH
TONIGHT...OR 12Z TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 303 AM CDT MON SEP 16 2013
THE CLOUD INCREASE IN THE WARM ADVECTION PATTERN WILL CONTINUE TO
EVOLVE TUESDAY AND SKIES SHOULD BECOME CLOUDY OR MOSTLY
CLOUDY...ESPECIALLY IN THE EAST. MEANWHILE...INSTABILITY CONTINUES
TO SLOWLY INCREASE BUT MAY BE LIMITED BY THE COPIOUS MOISTURE
ADVECTING IN...AND SUPPORT FOR SHOWERS AND STORMS IS OTHERWISE
QUITE MARGINAL. NEVERTHELESS...WITH MOISTURE INCREASING AT MOST
LEVELS...IT WOULD NOT TAKE MUCH FOR A FEW SHOWERS TO DEVELOP IN
OUR IOWA...MINNESOTA...AND EXTREME SOUTHEAST SD ZONES EVEN IF
THUNDERSTORMS HOLD OFF. WILL MENTION CHANCE OF SHOWERS AND
ISOLATED THUNDER. THIS SHOULD CONTINUE INTO TUESDAY NIGHT BUT
START TO MOVE SLOWLY EAST AND OUT OF THE AREA BY THE START OF
WEDNESDAY AS STRONG WARMING BEGINS TO OUTPACE THE MOISTURE...AND
RELATIVE HUMIDITIES AND CLOUD COVER DROPS OFF. TEMPERATURES WILL
BE WARMER TUESDAY BUT HELD DOWN SOME BY THE CLOUD COVER ESPECIALLY
EAST...THEN TUESDAY NIGHT SHOULD BE QUITE A BIT WARMER.
WEDNESDAY LOOK STILL SET TO BE A MUCH WARMER DAY WITH PLENTY OF
SUNSHINE. THE THREAT OF SHOWERS AND STORMS SHOULD HOLD OFF UNTIL
WEDNESDAY NIGHT WHEN THE COLD FRONT ENTERS THE AREA. HIGHS SHOULD
BE IN THE 80S WITH TEMPERATURES LIKELY REACHING A BIT ABOVE
GUIDANCE VALUES...AND WEDNESDAY NIGHT SHOULD BE WARM AGAIN AS THE
FRONT GETS INTO THE AREA.
FAIRLY POTENT FRONT TRACKS THROUGH THE EASTERN HALF OF THE
FORECAST AREA THURSDAY MORNING. ANY ONGOING SCATTERED SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF THE FRONT WILL TRACK EASTWARD
AND SHOULD DIMINISH BY LATE AFTERNOON. NORTHWEST WINDS WILL BE
BREEZY BEHIND THE FRONT AND PROVIDE A DECENT SHOT OF COLD AIR
ADVECTION THURSDAY NIGHT AND FRIDAY. LOWS WILL DIP INTO THE LOWER
50S ON THURSDAY AND AS COLD AS THE MID 40S FRIDAY NIGHT. WITH A
GENERAL UPPER LEVEL NORTHWEST FLOW PATTERN IN PLACE THROUGH THE
END OF THE WEEK...THE WEATHER WILL REMAIN DRY WITH HIGHS NEAR OR
JUST BELOW SEASONAL NORMALS. RIDGING OVER THE INTERMOUNTAIN WEST
SHIFTS EASTWARD INTO THE HIGH PLAINS FRIDAY NIGHT WITH THE AXIS
MOVING OVERHEAD SATURDAY NIGHT. WITH SOUTHERLY FLOW INCREASING ON
SUNDAY...TEMPERATURES WILL WARM BACK INTO THE MID 70S TO NEAR
80...BUT MAY ALSO BRING THE NEXT POTENTIAL FOR SHOWERS AND
THUNDERSTORMS. MODELS A BIT UNCERTAIN ON TIMING...BUT WILL LEAVE
LOW END CHANCES SUNDAY AND SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 623 AM CDT MON SEP 16 2013
STRATUS DECK AND PATCHY FOG REMAINS THE MAIN CONCERN THIS MORNING.
EXPECT THE PATCHY FOG...WHICH HAS DEVELOPED IN AREAS NOT BLANKETED IN
STATUS...TO QUICKLY DISSIPATE BY 14Z. STRATUS HAS BEEN HOVERING
AROUND 3000 TO 4500 FEET AND IS ADVECTING NORTHWARD AND EXPANDING IN
AREA. THIS STRATUS WILL LIKELY CONTINUE LIFTING NORTH NORTHWWARD
THROUGH MUCH OF THE MORNING...BUT SHOULD BEGIN TO ERRODE FROM AROUND
17Z THROUGH 00Z. COULD SEE SOME BRIEF CEILING DIPS TO MVFR
LEVELS...BUT OVERALL SHOULD REMAINS LOW END VFR. THIS LAYER MAY BUILD
NORTHEASTWARD...REDEVELOPING NEAR THE MISSOURI VALLEY AND AFTER 06Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1047 AM CDT MON SEP 16 2013
.UPDATE...
LOCAL 15Z SURFACE ANALYSIS SHOWS A COLD FRONT IN NORTHERN OKLAHOMA
WITH CONVECTION ONGOING IN CLOSE PROXIMITY TO THE FRONT. AN OUTFLOW
BOUNDARY HAS SURGED SOUTH OVERNIGHT AND THE BOUNDARY IS JUST
ENTERING OUR NORTHWESTERN ZONES. THE MOVEMENT HAS SLOWED DOWN AS
HEATING HAS COMMENCED...BUT DO EXPECT A CONTINUED MOVEMENT THIS
MORNING. THIS BOUNDARY WILL LIKELY SERVE AS A MECHANISM FOR
SHOWERS AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON ACROSS THE
NORTHERN HALF OF THE FORECAST AREA. CURRENT POP CONFIGURATION
LOOKS GOOD AND WILL MAKE NO CHANGES AT THIS TIME. NOT EXPECTING
SEVERE WEATHER AS CAPE VALUES REMAIN LESS THAN 1500 J/KG AND
SURFACE DEWPOINTS IN THE UPPER 60S SHOULD PREVENT DOWNBURST WINDS.
HOWEVER...A STRONG STORM IS POSSIBLE WITH GUSTY WINDS UP TO 50
MPH.
HAMPSHIRE
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THIS FORECAST AT ALL
TERMINALS.
ALTHOUGH A BOUNDARY MOVING SOUTHEAST OUT OF SOUTHWESTERN OKLAHOMA
WILL REMAIN NORTHWEST OF THE METROPLEX TERMINALS THIS AFTERNOON
AND EVENING...ISOLATED TO WIDELY SCATTERED SHRA/TSRA WILL BE
POSSIBLE AROUND THE METROPLEX AND WILL CARRY VCTS FOR THE
METROPLEX TERMINALS 22-01Z. FEEL CONVECTION WILL REMAIN FAR
OUTSIDE OF KACT AERODROME TODAY AND THIS EVENING. LIGHT SOUTHEAST
WINDS THIS MORNING WILL BECOME MORE EASTERLY BY MIDDAY AND SHOULD
REMAIN SO AND LIGHT IN SPEED THROUGH TUESDAY MID- MORNING. 75
&&
.PREV DISCUSSION... /ISSUED 408 AM CDT MON SEP 16 2013/
EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN EXTENSIVE
PLUME OF TROPICAL MOISTURE OVER CENTRAL MEXICO DUE TO TROPICAL
DEPRESSION MANUEL MOVING ONSHORE THE WEST CENTRAL MEXICAN COAST. A
SECONDARY TROPICAL PLUME OF MOISTURE ASSOCIATED WITH HURRICANE
INGRID REMAINED JUST OFF SHORE OF THE NORTHEAST MEXICAN COAST.
ACROSS THE CONUS...A STRONG UPPER LEVEL TROUGH CONTINUED TO MOVE
SOUTHEAST OVER THE GREAT LAKES REGION TOWARDS THE EAST COAST. THE
SUBTROPICAL RIDGING THAT HAD BEEN DOMINATING THE PLAINS HAD BEEN
FLATTENED AND TILTED OVER THE SOUTHEASTERN UNITED STATES IN
RESPONSE TO THE PASSAGE OF THE STRONG NORTHERN STREAM TROUGH. THIS
LEFT GENERALLY WEAK WESTERLY FLOW OVER THE CENTRAL AND SOUTH
PLAINS THIS MORNING. A WEAK SHORTWAVE TROUGH WAS OBSERVED OVER THE
TX AND OK PANHANDLES...MOVING SLOWLY EAST ALONG A NEARLY STALLED
OUT COLD FRONT.
REGIONAL RADARS SHOWED A LARGE CLUSTER OF SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THE FRONT AND SHORTWAVE TROUGH AT 0830Z OR 330 AM
EXTENDING FROM AMARILLO TO NORTH CENTRAL OK. KFDR RADAR WAS
TRACKING A CONSOLIDATED OUTFLOW BOUNDARY THAT WAS MOVING SOUTHEAST
AWAY FROM THESE SHOWERS AND STORMS TOWARDS NORTH TEXAS.
TODAY...THE RAP AND THE NAM BOTH BOTH INDICATE THAT THE
CONSOLIDATED OUTFLOW BOUNDARY MOVING TOWARDS NORTH TEXAS EARLY
THIS MORNING WILL CONTINUE SOUTHEAST INTO THE CWA JUST AFTER
SUNRISE. THIS BOUNDARY WILL LIKELY STALL OUT SOMEWHERE NORTHWEST
OF THE DFW METROPLEX...WITH THE LATEST GUIDANCE SUGGESTING THE
BOUNDARY WILL COME TO REST NEAR A GAINESVILLE TO WEATHERFORD TO
CISCO LINE BY LATE THIS MORNING. LOCATIONS NEAR AND NORTHWEST OF
THE BOUNDARY WILL LIKELY SEE SOME ISOLATED TO SCATTERED RAIN
SHOWERS AND THUNDERSTORMS DEVELOP BY THE EARLY AFTERNOON HOURS OF
THE DAY. THIS IS PRIMARILY DUE TO THE FACT THAT THERE IS AMPLE
LOW-LEVEL MOISTURE IN PLACE TO SUPPORT PRECIPITATION...WITH THE
FRONT ACTING AS A LIFTING MECHANISM IN AN ENVIRONMENT
CHARACTERIZED WITH LITTLE TO NO CAPPING INVERSION ALOFT. WENT
AHEAD WITH A 30 PERCENT CHANCE OF RAIN FOR THESE LOCATIONS AS A
RESULT...INCLUDING MUCH OF THE DFW AREA.
ELSEWHERE ACROSS NORTH AND CENTRAL TEXAS...THE THERMODYNAMIC
ENVIRONMENT WILL BE NEARLY EQUIVALENT TO LOCATIONS NEAR THE
OUTFLOW BOUNDARY...BUT THERE IS NO OBVIOUS LIFTING MECHANISM TO
SUPPORT THE INITIATION OF SHOWERS AND STORMS THIS AFTERNOON.
DURING THE PEAK HEATING HOURS OF THE DAY...THE BUOYANCY FORCE WILL
BE MAXIMIZED...AND ISOLATED SHOWERS AND STORMS MAY DEVELOP
ANYWHERE ACROSS THE CWA AS A RESULT. MOST PRECIPITATION SHOULD
REMAIN TIED TO DAYTIME HEATING TODAY...THEREFORE WENT AHEAD AND
KEPT A MENTION OF SHOWERS AND STORMS IN THE FORECAST ONLY THROUGH
03Z THIS EVENING.
HEATING IS A BIT OF A CONCERN TODAY BECAUSE WE HAVE EXTENSIVE
CLOUD COVER IN THE FORM OF CIRRUS CLOUDS OVER THE REGION. THESE
CLOUDS MAY BREAK UP A BIT THROUGHOUT THE DAY...BUT WE WILL NEVER
BE FULLY RID OF THEM. REGARDLESS...AT 3 AM REGIONAL TEMPERATURES
WERE HOLDING IN THE MID TO UPPER 70S FOR MOST LOCATIONS. SO
DESPITE PERSISTENT CIRRUS CLOUDS TO CONTEND WITH...A 15 TO 20
DEGREE TEMPERATURE INCREASE SHOULD BE EASY TO ATTAIN BRINGING MOST
LOCATIONS UP INTO THE MID 90S FOR HIGHS WHICH IS WARM ENOUGH TO
SUPPORT ISOLATED STORMS IN THE FORECAST.
CONCERNING THE REMNANTS OF INGRID AND MANUEL...WITH THE
SUBTROPICAL RIDGE FLATTENED OUT...ITS CENTER OF CIRCULATION IS
EXPECTED TO SET UP ANYWHERE FROM SOUTHEAST TX TO THE MISSISSIPPI
COAST THROUGH THIS PERIOD. THE EXACT POSITION OF THIS RIDGE WILL
PLAY A LARGE ROLE IN TROPOSPHERIC STEERING FLOW/TRAJECTORIES FOR
TROPICAL MOISTURE INTO NORTH TX THROUGHOUT THE WEEK HEADED INTO
THIS WEEKEND. IF THE SUBTROPICAL RIDGE SETS UP FURTHER EAST...DEEP
TROPOSPHERIC FLOW WOULD FAVOR TRANSPORTING THE COMBINED MOISTURE
PLUMES FROM MANUEL AND INGRID FROM NORTHERN MEXICO INTO NORTH TX
BY LATE THIS WEEK. IF THE RIDGE SETS UP FURTHER WEST...THE MID AND
UPPER LEVEL TROPICAL MOISTURE WILL BE SHUNTED WEST AWAY FROM
TEXAS. UNFORTUNATELY MODELS REMAIN INCONSISTENT WITH REGARDS TO
THIS SOLUTION...SO DID NOT MAKE ANY HUGE ADJUSTMENTS TO THE
PREVIOUS FORECAST AT THIS TIME.
IN GENERAL...CONTINUE TO CARRY LOW POPS/RAIN CHANCES FROM TUESDAY
THROUGH THURSDAY...BECOMING MORE CONFIDENT AND WIDESPREAD WITH
RAIN CHANCES FOR FRIDAY AND SATURDAY BEFORE RETURNING TO A DRY
FORECAST ON SUNDAY. FOR MORE DETAILS READ ON...
TUESDAY THROUGH THURSDAY...REGARDLESS OF WHAT HAPPENS WITH THE
TROPICAL MOISTURE PLUME FROM THE MEXICAN TROPICAL CYCLONES...THE
MOST IMPORTANT THING TO WATCH DURING THIS TIME FRAME IS THE
DIRECTION OF LOW LEVEL WINDS. LOOKING AT THE 850 MB LEVEL...WINDS
THAT REMAIN EASTERLY NEAR THE GULF COAST WILL PREVENT RICH LOW-
LEVEL MOISTURE FROM MAKING ITS WAY NORTH INTO NORTH TX WHILE
SOUTHEASTERLY WINDS WILL SEND THIS MOISTURE RIGHT UP THE I-35
CORRIDOR. THE ECMWF HAS BEEN THE MOST CONSISTENT IN FORECAST 850
MB WINDS THE PAST FEW DAYS...SO THIS FORECAST CLOSELY FOLLOWS THE
GUIDANCE OF THIS MODEL.
THE ECMWF MAINTAINS EASTERLY WINDS AT 850 MB THROUGH WEDNESDAY
MORNING. AS A RESULT...DROPPED POPS ON TUESDAY TO 10 PERCENT FOR
THE ENTIRE CWA WITH LESS CONFIDENCE IN MOISTURE AVAILABLE AND
INSTABILITY TUESDAY AFTERNOON. THE 850 MB FLOW VEERS THROUGHOUT
THE DAY ON WEDNESDAY SLOWLY SENDING RICH GULF MOISTURE NORTH INTO
THE CWA FROM THE SOUTHEAST WEDNESDAY AFTERNOON. WENT AHEAD WITH 20
PERCENT CHANCE OF STORMS FOR THE SOUTHEASTERN HALF OF THE FORECAST
AREA AS A RESULT. BY THURSDAY AFTERNOON...H850 FLOW IS SOUTH-
SOUTHEASTERLY WHICH WOULD START SENDING SOME DEEPER TROPICAL
MOISTURE INTO THE CWA. WENT AHEAD WITH WIDESPREAD 20 POPS FOR THE
ENTIRE AREA THURSDAY AND THURSDAY NIGHT ASSUMING THE ECMWF PANS
OUT AS EXPECTED. WHILE THE GFS HAS TIMING DIFFERENCES...ONCE THE
850 MB FLOW VEERS AROUND TO THE SOUTHEAST...THE GFS INDICATES
PWATS INCREASE TO 2 INCHES. THIS WOULD BE GETTING CLOSE TO 2
STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR WHICH
CERTAINLY SUPPORTS THE BROAD BRUSHED POPS.
FRIDAY AND SATURDAY...THE BIG QUESTION FOR THIS PERIOD IS...WILL
WE HAVE MID AND UPPER LEVEL TROPICAL MOISTURE IN PLACE COURTESY OF
MANUEL AND INGRID? IF WE DO...POPS WILL HAVE TO BE INCREASED MORE
THAN WHAT WE ARE CARRYING AT THIS TIME. EACH DAY A DIFFERENT MODEL
SHOWS THIS SOLUTION WHILE ANOTHER ONE BACKS OFF. THE CONSENSUS IS
ALWAYS AN ANSWER OF /NO/...BUT THE CONSENSUS NEVER CONSISTS OF THE
SAME MODELS. AS A RESULT CONFIDENCE IS LOW AS TO WHERE THE MEXICAN
TROPICAL MOISTURE PLUME WILL END UP AT THIS TIME.
EITHER WAY...THE CONSENSUS OF MODEL GUIDANCE CONTINUES TO SHOW A
SEASONABLY STRONG TROUGH MOVING EAST OVER THE PLAINS DURING THIS
TIME FRAME. THIS WOULD SEND A STRONGER COLD FRONT SOUTH INTO NORTH
TX WHICH SUPPORTS AT LEAST SCATTERED THUNDERSTORMS AS IT MOVES
SOUTH THROUGH THE REGION. WE ALREADY HAD 30 TO 40 POPS IN THE
FORECAST ALONG THIS FRONT...SO JUST MAINTAINED THIS FORECAST AT
THIS TIME. WILL CONTINUE TO CLOSELY MONITOR THE MEXICAN TROPICAL
MOISTURE PLUME IN THE COMING DAYS. IF THIS MOISTURE IS IN PLACE IT
DOES NOT REALLY CHANGE WHEN WE EXPECT SHOWERS AND STORMS...IT JUST
AFFECTS THE COVERAGE AND AMOUNTS OF RAINFALL. EITHER WAY...WE WILL
LIKELY BE DRY ON SUNDAY AS SUBSIDENCE SWEEPS THROUGH THE REGION.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 95 76 95 77 96 / 30 20 10 10 10
WACO, TX 96 74 96 75 96 / 10 10 10 10 20
PARIS, TX 96 70 95 72 95 / 20 20 10 10 10
DENTON, TX 94 73 94 74 95 / 30 20 10 10 10
MCKINNEY, TX 95 73 95 75 96 / 30 20 10 10 10
DALLAS, TX 97 78 96 79 97 / 30 20 10 10 10
TERRELL, TX 96 75 96 75 97 / 20 20 10 10 10
CORSICANA, TX 97 75 97 76 97 / 10 10 10 10 20
TEMPLE, TX 96 73 95 72 95 / 10 10 10 10 20
MINERAL WELLS, TX 93 71 93 72 94 / 30 20 10 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
623 AM CDT MON SEP 16 2013
.DISCUSSION...
SEE AVIATION FOR 12Z TAF ISSUANCE
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. DEEPER MOISTURE
ALONG THE COAST WILL AID IN SCATTERED SHOWER DEVELOPMENT LATER
THIS MORNING INTO EARLY AFTERNOON. GREATEST COVERAGE WILL REMAIN
TO THE SOUTH AND WEST OF THE TERMINALS BUT CONFIDENCE IS HIGH
ENOUGH TO INCLUDE A VCSH FOR SGR...LBX...AND GLS. SOME MODEL
GUIDANCE EXPANDS THE SHRA ACTIVITY UP TO HOU BUT FEEL THAT THEY
WILL REMAIN RIGHT ON THE EDGE OF THE BETTER MOISTURE AND HAVE
LEFT OUT VCSH MENTION FOR NOW. 38
&&
.PREV DISCUSSION... /ISSUED 428 AM CDT MON SEP 16 2013/
DISCUSSION...
THE RADAR THIS MORNING SHOWS A FEW SHOWERS ALONG THE COAST MAINLY
BETWEEN KLBX AND KBYY. SFC ANALYSIS SHOWS DISSIPATING FRONT OVER E
TX THROUGH C LA. ANOTHER COLD FRONT WAS PUSHING THROUGH THE S
PLAINS BUT LIKELY STALL BEFORE EVEN REACHING TX. THERE IS A WEAK
COASTAL TROUGH DUE TO HURRICANE INGRID JUST OFF THE COAST OF
MEXICO. THIS HAS HELPED FORCE SOME SHOWERS BUT MOST OF THE
ACTIVITY IS OVER S TX. ANALYSIS OF 500MB SHOWS THAT THE UPPER
LEVEL RIDGE OVER TX HAS STRENGTHENED AND BROADENED THROUGH THE
GULF COAST INTO THE CAROLINAS. THIS HAS PROVIDED ENOUGH STEERING
TO PUSH INGRID TOWARDS MEXICO. THE 00Z CRP SOUNDING SHOWS NEARLY
2.1 INCHES OF PRECIP WATER AND GOES SOUNDER IMAGERY SHOWS THAT
THIS MUCH MOISTURE ALSO EXTENDS INTO SE TX. CERTAINLY EXPECT
THERE TO BE MORE CONVECTION ONCE DAY TIME HEATING OCCURS. LATEST
06Z HRRR RUN SHOWS CONVECTION FORMING ALONG THE COAST AND THEN
DEVELOPING INLAND BETWEEN HOUSTON AND VICTORIA ALONG US 59. THIS
MAY BE WHERE THE BEST MOISTURE EXISTS AND WHERE SUBSIDENCE FROM
THE UPPER LEVEL RIDGE MAY BE WEAKEST. THAT WILL BE THE MAIN
CHALLENGE THROUGH MID WEEK...FORECASTING CONVECTIVE COVERAGE DUE
TO DEEP MOISTURE AND WHETHER THE RIDGE WILL BE STRONG ENOUGH TO
INHIBIT CONVECTION. DECIDED TO KEEP 20/30 POPS IN THE FORECAST
THROUGH WED. MAX TEMPS WILL ALSO BE TRICKY DUE TO CLOUD COVER BUT
DECIDED TO HEDGE MAX TEMPS A DEGREE OR TWO ABOVE GUIDANCE AS STILL
ENOUGH DAY LIGHT FOR HEATING.
AFTER WEDNESDAY FORECAST MODELS SHOW THE UPPER LEVEL RIDGE
WEAKENING WITH A POTENT TROUGH PUSHING ACROSS THE N PLAINS. THUR
INTO FRI LOOKS LIKE DEEP BOUNDARY LAYER FLOW OFF THE GULF AND EVEN
FROM THE CARIBBEAN DEVELOPS. PRECIP WATER VALUES INCREASE TO 2-2.2
INCHES ON THUR AND MAX OUT AT 2.5 INCHES ON FRI PER THE GFS. BOTH
THE ECMWF AND GFS ARE RATHER WET FOR FRI INTO SAT. AS SUCH WILL
HAVE 30/40 POPS FOR THUR AND THEN 40 POPS FRI INTO SAT. THERE IS
THE POTENTIAL FOR HIGHER POPS AS THIS IS STILL DAY 5/6 OF THE
FORECAST. STILL PLENTY OF TIME FOR THE FORECAST TO CHANGE BUT
THERE IS A LEAST A COUPLE OF DAYS OF MODEL CONSISTENCY FOR THE 00Z
MODELS SHOWING THE POTENTIAL FOR RAINFALL FOR THE END OF THE WEEK.
MAX TEMPS FOR THE WEEK WILL BE IN LINE WITH GUIDANCE...MAYBE A
DEGREE OR TWO WARMER DUE TO THE RIDGE FOR THE NEXT COUPLE OF DAYS.
AS FOR HURRICANE INGRID...AGAIN SHOULD HAVE VERY LITTLE IMPACT
FOR SE TX AS IT SHOULD BE MAKING LANDFALL NORTH OF TAMPICO. THE
HURRICANE IS UNDER THE INFLUENCE OF SOME UPPER LEVEL SHEAR SO IT
IS ONLY A MINIMAL HURRICANE. MAIN IMPACTS FOR SE TX WILL JUST BE
CAUSING AN INFLUX OF MOISTURE AND MARINE INFLUENCES. RIP CURRENTS
WILL BE AN ISSUE AS WILL HIGHER SURF. ELEVATED TIDES OF A FOOT
ABOVE NORMAL LOOKS TO BE THE PEAK SO COASTAL FLOODING WILL NOT BE
A PROBLEM.
39
MARINE...
MODERATE TO STRONG EASTERLY FLOW WILL CONTINUE TODAY AS WE LIE IN
A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRESSURE ACROSS THE
SOUTHEASTERN UNITED STATES AND HURRICANE INGRID ALONG THE MEXICAN
COAST. WITH SEAS AND WINDS EXPECTED TO REMAIN ELEVATED HAVE
EXTENDED THE SCA FOR ALL OFFSHORE WATERS AND CAUTION FOR BAYS
THROUGH TUESDAY MORNING. TIDE LEVELS WILL REMAIN BETWEEN ONE HALF
AND ONE FOOT ABOVE NORMAL. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 95 75 95 74 96 / 10 10 20 10 20
HOUSTON (IAH) 93 75 94 74 94 / 20 10 20 10 20
GALVESTON (GLS) 90 81 89 80 89 / 20 20 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH TUESDAY MORNING FOR
THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 8 AM CDT TUESDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
613 AM CDT MON SEP 16 2013
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THIS FORECAST AT ALL
TERMINALS.
ALTHOUGH A BOUNDARY MOVING SOUTHEAST OUT OF SOUTHWESTERN OKLAHOMA
WILL REMAIN NORTHWEST OF THE METROPLEX TERMINALS THIS AFTERNOON
AND EVENING...ISOLATED TO WIDELY SCATTERED SHRA/TSRA WILL BE
POSSIBLE AROUND THE METROPLEX AND WILL CARRY VCTS FOR THE
METROPLEX TERMINALS 22-01Z. FEEL CONVECTION WILL REMAIN FAR
OUTSIDE OF KACT AERODROME TODAY AND THIS EVENING. LIGHT SOUTHEAST
WINDS THIS MORNING WILL BECOME MORE EASTERLY BY MIDDAY AND SHOULD
REMAIN SO AND LIGHT IN SPEED THROUGH TUESDAY MID- MORNING. 75
&&
.PREV DISCUSSION... /ISSUED 408 AM CDT MON SEP 16 2013/
EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN EXTENSIVE
PLUME OF TROPICAL MOISTURE OVER CENTRAL MEXICO DUE TO TROPICAL
DEPRESSION MANUEL MOVING ONSHORE THE WEST CENTRAL MEXICAN COAST. A
SECONDARY TROPICAL PLUME OF MOISTURE ASSOCIATED WITH HURRICANE
INGRID REMAINED JUST OFF SHORE OF THE NORTHEAST MEXICAN COAST.
ACROSS THE CONUS...A STRONG UPPER LEVEL TROUGH CONTINUED TO MOVE
SOUTHEAST OVER THE GREAT LAKES REGION TOWARDS THE EAST COAST. THE
SUBTROPICAL RIDGING THAT HAD BEEN DOMINATING THE PLAINS HAD BEEN
FLATTENED AND TILTED OVER THE SOUTHEASTERN UNITED STATES IN
RESPONSE TO THE PASSAGE OF THE STRONG NORTHERN STREAM TROUGH. THIS
LEFT GENERALLY WEAK WESTERLY FLOW OVER THE CENTRAL AND SOUTH
PLAINS THIS MORNING. A WEAK SHORTWAVE TROUGH WAS OBSERVED OVER THE
TX AND OK PANHANDLES...MOVING SLOWLY EAST ALONG A NEARLY STALLED
OUT COLD FRONT.
REGIONAL RADARS SHOWED A LARGE CLUSTER OF SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THE FRONT AND SHORTWAVE TROUGH AT 0830Z OR 330 AM
EXTENDING FROM AMARILLO TO NORTH CENTRAL OK. KFDR RADAR WAS
TRACKING A CONSOLIDATED OUTFLOW BOUNDARY THAT WAS MOVING SOUTHEAST
AWAY FROM THESE SHOWERS AND STORMS TOWARDS NORTH TEXAS.
TODAY...THE RAP AND THE NAM BOTH BOTH INDICATE THAT THE
CONSOLIDATED OUTFLOW BOUNDARY MOVING TOWARDS NORTH TEXAS EARLY
THIS MORNING WILL CONTINUE SOUTHEAST INTO THE CWA JUST AFTER
SUNRISE. THIS BOUNDARY WILL LIKELY STALL OUT SOMEWHERE NORTHWEST
OF THE DFW METROPLEX...WITH THE LATEST GUIDANCE SUGGESTING THE
BOUNDARY WILL COME TO REST NEAR A GAINESVILLE TO WEATHERFORD TO
CISCO LINE BY LATE THIS MORNING. LOCATIONS NEAR AND NORTHWEST OF
THE BOUNDARY WILL LIKELY SEE SOME ISOLATED TO SCATTERED RAIN
SHOWERS AND THUNDERSTORMS DEVELOP BY THE EARLY AFTERNOON HOURS OF
THE DAY. THIS IS PRIMARILY DUE TO THE FACT THAT THERE IS AMPLE
LOW-LEVEL MOISTURE IN PLACE TO SUPPORT PRECIPITATION...WITH THE
FRONT ACTING AS A LIFTING MECHANISM IN AN ENVIRONMENT
CHARACTERIZED WITH LITTLE TO NO CAPPING INVERSION ALOFT. WENT
AHEAD WITH A 30 PERCENT CHANCE OF RAIN FOR THESE LOCATIONS AS A
RESULT...INCLUDING MUCH OF THE DFW AREA.
ELSEWHERE ACROSS NORTH AND CENTRAL TEXAS...THE THERMODYNAMIC
ENVIRONMENT WILL BE NEARLY EQUIVALENT TO LOCATIONS NEAR THE
OUTFLOW BOUNDARY...BUT THERE IS NO OBVIOUS LIFTING MECHANISM TO
SUPPORT THE INITIATION OF SHOWERS AND STORMS THIS AFTERNOON.
DURING THE PEAK HEATING HOURS OF THE DAY...THE BUOYANCY FORCE WILL
BE MAXIMIZED...AND ISOLATED SHOWERS AND STORMS MAY DEVELOP
ANYWHERE ACROSS THE CWA AS A RESULT. MOST PRECIPITATION SHOULD
REMAIN TIED TO DAYTIME HEATING TODAY...THEREFORE WENT AHEAD AND
KEPT A MENTION OF SHOWERS AND STORMS IN THE FORECAST ONLY THROUGH
03Z THIS EVENING.
HEATING IS A BIT OF A CONCERN TODAY BECAUSE WE HAVE EXTENSIVE
CLOUD COVER IN THE FORM OF CIRRUS CLOUDS OVER THE REGION. THESE
CLOUDS MAY BREAK UP A BIT THROUGHOUT THE DAY...BUT WE WILL NEVER
BE FULLY RID OF THEM. REGARDLESS...AT 3 AM REGIONAL TEMPERATURES
WERE HOLDING IN THE MID TO UPPER 70S FOR MOST LOCATIONS. SO
DESPITE PERSISTENT CIRRUS CLOUDS TO CONTEND WITH...A 15 TO 20
DEGREE TEMPERATURE INCREASE SHOULD BE EASY TO ATTAIN BRINGING MOST
LOCATIONS UP INTO THE MID 90S FOR HIGHS WHICH IS WARM ENOUGH TO
SUPPORT ISOLATED STORMS IN THE FORECAST.
CONCERNING THE REMNANTS OF INGRID AND MANUEL...WITH THE
SUBTROPICAL RIDGE FLATTENED OUT...ITS CENTER OF CIRCULATION IS
EXPECTED TO SET UP ANYWHERE FROM SOUTHEAST TX TO THE MISSISSIPPI
COAST THROUGH THIS PERIOD. THE EXACT POSITION OF THIS RIDGE WILL
PLAY A LARGE ROLE IN TROPOSPHERIC STEERING FLOW/TRAJECTORIES FOR
TROPICAL MOISTURE INTO NORTH TX THROUGHOUT THE WEEK HEADED INTO
THIS WEEKEND. IF THE SUBTROPICAL RIDGE SETS UP FURTHER EAST...DEEP
TROPOSPHERIC FLOW WOULD FAVOR TRANSPORTING THE COMBINED MOISTURE
PLUMES FROM MANUEL AND INGRID FROM NORTHERN MEXICO INTO NORTH TX
BY LATE THIS WEEK. IF THE RIDGE SETS UP FURTHER WEST...THE MID AND
UPPER LEVEL TROPICAL MOISTURE WILL BE SHUNTED WEST AWAY FROM
TEXAS. UNFORTUNATELY MODELS REMAIN INCONSISTENT WITH REGARDS TO
THIS SOLUTION...SO DID NOT MAKE ANY HUGE ADJUSTMENTS TO THE
PREVIOUS FORECAST AT THIS TIME.
IN GENERAL...CONTINUE TO CARRY LOW POPS/RAIN CHANCES FROM TUESDAY
THROUGH THURSDAY...BECOMING MORE CONFIDENT AND WIDESPREAD WITH
RAIN CHANCES FOR FRIDAY AND SATURDAY BEFORE RETURNING TO A DRY
FORECAST ON SUNDAY. FOR MORE DETAILS READ ON...
TUESDAY THROUGH THURSDAY...REGARDLESS OF WHAT HAPPENS WITH THE
TROPICAL MOISTURE PLUME FROM THE MEXICAN TROPICAL CYCLONES...THE
MOST IMPORTANT THING TO WATCH DURING THIS TIME FRAME IS THE
DIRECTION OF LOW LEVEL WINDS. LOOKING AT THE 850 MB LEVEL...WINDS
THAT REMAIN EASTERLY NEAR THE GULF COAST WILL PREVENT RICH LOW-
LEVEL MOISTURE FROM MAKING ITS WAY NORTH INTO NORTH TX WHILE
SOUTHEASTERLY WINDS WILL SEND THIS MOISTURE RIGHT UP THE I-35
CORRIDOR. THE ECMWF HAS BEEN THE MOST CONSISTENT IN FORECAST 850
MB WINDS THE PAST FEW DAYS...SO THIS FORECAST CLOSELY FOLLOWS THE
GUIDANCE OF THIS MODEL.
THE ECMWF MAINTAINS EASTERLY WINDS AT 850 MB THROUGH WEDNESDAY
MORNING. AS A RESULT...DROPPED POPS ON TUESDAY TO 10 PERCENT FOR
THE ENTIRE CWA WITH LESS CONFIDENCE IN MOISTURE AVAILABLE AND
INSTABILITY TUESDAY AFTERNOON. THE 850 MB FLOW VEERS THROUGHOUT
THE DAY ON WEDNESDAY SLOWLY SENDING RICH GULF MOISTURE NORTH INTO
THE CWA FROM THE SOUTHEAST WEDNESDAY AFTERNOON. WENT AHEAD WITH 20
PERCENT CHANCE OF STORMS FOR THE SOUTHEASTERN HALF OF THE FORECAST
AREA AS A RESULT. BY THURSDAY AFTERNOON...H850 FLOW IS SOUTH-
SOUTHEASTERLY WHICH WOULD START SENDING SOME DEEPER TROPICAL
MOISTURE INTO THE CWA. WENT AHEAD WITH WIDESPREAD 20 POPS FOR THE
ENTIRE AREA THURSDAY AND THURSDAY NIGHT ASSUMING THE ECMWF PANS
OUT AS EXPECTED. WHILE THE GFS HAS TIMING DIFFERENCES...ONCE THE
850 MB FLOW VEERS AROUND TO THE SOUTHEAST...THE GFS INDICATES
PWATS INCREASE TO 2 INCHES. THIS WOULD BE GETTING CLOSE TO 2
STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR WHICH
CERTAINLY SUPPORTS THE BROAD BRUSHED POPS.
FRIDAY AND SATURDAY...THE BIG QUESTION FOR THIS PERIOD IS...WILL
WE HAVE MID AND UPPER LEVEL TROPICAL MOISTURE IN PLACE COURTESY OF
MANUEL AND INGRID? IF WE DO...POPS WILL HAVE TO BE INCREASED MORE
THAN WHAT WE ARE CARRYING AT THIS TIME. EACH DAY A DIFFERENT MODEL
SHOWS THIS SOLUTION WHILE ANOTHER ONE BACKS OFF. THE CONSENSUS IS
ALWAYS AN ANSWER OF /NO/...BUT THE CONSENSUS NEVER CONSISTS OF THE
SAME MODELS. AS A RESULT CONFIDENCE IS LOW AS TO WHERE THE MEXICAN
TROPICAL MOISTURE PLUME WILL END UP AT THIS TIME.
EITHER WAY...THE CONSENSUS OF MODEL GUIDANCE CONTINUES TO SHOW A
SEASONABLY STRONG TROUGH MOVING EAST OVER THE PLAINS DURING THIS
TIME FRAME. THIS WOULD SEND A STRONGER COLD FRONT SOUTH INTO NORTH
TX WHICH SUPPORTS AT LEAST SCATTERED THUNDERSTORMS AS IT MOVES
SOUTH THROUGH THE REGION. WE ALREADY HAD 30 TO 40 POPS IN THE
FORECAST ALONG THIS FRONT...SO JUST MAINTAINED THIS FORECAST AT
THIS TIME. WILL CONTINUE TO CLOSELY MONITOR THE MEXICAN TROPICAL
MOISTURE PLUME IN THE COMING DAYS. IF THIS MOISTURE IS IN PLACE IT
DOES NOT REALLY CHANGE WHEN WE EXPECT SHOWERS AND STORMS...IT JUST
AFFECTS THE COVERAGE AND AMOUNTS OF RAINFALL. EITHER WAY...WE WILL
LIKELY BE DRY ON SUNDAY AS SUBSIDENCE SWEEPS THROUGH THE REGION.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 95 76 95 77 96 / 30 20 10 10 10
WACO, TX 96 74 96 75 96 / 10 10 10 10 20
PARIS, TX 96 70 95 72 95 / 20 20 10 10 10
DENTON, TX 94 73 94 74 95 / 30 20 10 10 10
MCKINNEY, TX 95 73 95 75 96 / 30 20 10 10 10
DALLAS, TX 97 78 96 79 97 / 30 20 10 10 10
TERRELL, TX 96 75 96 75 97 / 20 20 10 10 10
CORSICANA, TX 97 75 97 76 97 / 10 10 10 10 20
TEMPLE, TX 96 73 95 72 95 / 10 10 10 10 20
MINERAL WELLS, TX 92 71 93 72 94 / 30 20 10 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
444 AM MDT MON SEP 16 2013
.SHORT TERM...(TODAY AND TUESDAY NIGHT)
ISSUED AT 332 AM MDT MON SEP 16 2013
THE LONG WAITED BREAK IN THE WET WEATHER IS ON ITS WAY. SHORTWAVE
OVER SOUTHEAST WYOMING THIS MORNING WILL LIFT NORTHEAST TODAY
WHILE BEING SHEARED. MOIST SOUTHERLY FLOW AND WEAK FORCING
ASSOCIATED WITH THE SHORTWAVE WILL PRODUCE SOME LIGHT DRIZZLE THIS
MORNING IN THE PLAINS. THE DRIZZLE WILL END BY LATE THIS MORNING
AS THE BOUNDARY LAYER MIXES AND DRIER AIR PUNCHES IN FROM THE
WEST. THERE IS A CHANCE OF A FEW SHOWERS AND THUNDERSTORMS THIS
AFTERNOON...MAINLY OVER AND NEAR THE MOUNTAINS. SUBSIDENCE BEHIND
THE SHORTWAVE WILL LIMIT OVERALL PRECIPITATION CHANCES THIS
AFTENOON BUT THERE MAY BE ENOUGH INSTABILITY AND RISIDUAL BOUNDARY
LAYER MOISTURE TO POP ISOLATED CONVECTION INTO THE PLAINS LATE
THIS AFTERNOON. EITHER WAY...CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL QUICKLY SUBSIDE THIS EVENING AS SUBSIDENCE AND DRY WESTERLY
FLOW ALOFT SHUT DOWN ANY PRECIPITATION.
TUESDAY WILL START OFF WITH CLEAR SKIES AND TEMPERATURES MOSTLY IN
THE 50S. DRY WEST FLOW WILL ALLOW TEMPERATURES TO WARM NICELY WITH
HIGHS IN THE 70S WEST TO 80S INTO THE PLAINS. MAY EVEN SEE ONE OR
TWO 90 DEGREE READINGS IN THE NEBRASKA PANHANDLE. MODELS ARE
SHOWING A QUICK MOVING SHORTWAVE AFFECTING THE WESTERN CWA BY
LATE TUESDAY AFTERNOON AND EVENING. THIS WAVE COULD TRIGGER SOME
SHOWERS OR WEAK THUNDERSTORMS OVER THE HIGHER ELEVATIONS OF
SOUTHEAST WYOMING LATE IN THE DAY WITH SOME ACTIVITY SHIFTING INTO
THE PLAINS DURING THE EVENING. NOT EXPECTING MUCH IN THE WAY OF
PRECIPIATION AS MOISTURE WILL BE LIMITED AT BEST.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 332 AM MDT MON SEP 16 2013
RATHER PROGRESSIVE PATTERN IN THE LONG TERM WITH THE MODELS
CONTINUING TO ADVERTISE PERIODS OF WARM AND BREEZY SOUTHWEST WINDS
FOLLOWED BY COOLER AND CALMER DAYS. UPPER LEVEL TROUGH WILL SCOOT
ACROSS MONTANA ON WEDNESDAY WITH A SFC LOW DEVELOPING DURING THE
AFTN ACROSS WESTERN NORTH DAKOTA. THIS STRENGTHENS THE PRESSURE
GRADIENT WITH SOUTHWEST WINDS BECOMING QUITE BREEZY ALONG AND WEST
OF THE LARAMIE RANGE. CURRENTLY APPEARS THAT GUSTS TO 40 MPH WILL
BE POSSIBLE. DRY FRONTAL PASSAGE OCCURS BY LATE WEDNESDAY NIGHT
WITH 700MB TEMPS DROPPING ABOUT 8C ON THURSDAY. TEMPS WILL BE MORE
SEASONAL BEHIND THE FRONT AND WINDS WILL DROP OFF BY THURSDAY AFTN
AS THE SFC HIGH MOVES OVERHEAD. THURSDAY NIGHT WILL LIKELY BE THE
COOLEST NIGHT OF THE FALL SO FAR WITH WEAK WINDS AND CLEAR SKIES
RESULTING IN GREAT RADIATIONAL COOLING.
BRIEF UPPER LEVEL RIDGING IS OVER THE REGION ON FRIDAY AHEAD OF
THE NEXT SYSTEM THAT IS PROGGED TO AMPLIFY ACROSS THE WESTERN
STATES ON SATURDAY. THIS WAVE WEAKENS AND LIFTS NORTHEASTWARD OVER
NORTHERN WY BY LATER SATURDAY AND SUNDAY. PRESSURE FALLS AHEAD OF
THE SYSTEM WILL CAUSE SOUTHWEST WINDS TO INCREASE ONCE
AGAIN...WITH OCCASIONAL GUSTS TO 40 MPH TO THE WEST OF THE LARAMIE
RANGE. SIMILAR TO THE MIDWEEK TROUGH...THE BEST DYNAMICS AND MOISTURE
WILL BE TO THE NORTH OF AREA...SO PRECIP CHANCES AND CLOUD COVER
WILL BE MINIMAL WITH THE TROUGH PASSAGE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING)
ISSUED AT 1103 PM MDT SUN SEP 15 2013
LATEST 11-3.9U SATELLITE IMAGERY SHOWING LOW CLOUDS ADVECTING
NORTH OUT OF NORTHEASTERN COLORADO INTO THE PANHANDLE. THIS
MATCHES UP WELL WITH THE LATEST HRRR FORECAST FOR LOWERING
CEILINGS IN THE PANHANDLE. MOST OF THE PANHANDLE SHOULD FALL INTO
THE IFR CATEGORY AFTER 08Z. THE EXCEPTION BEING KCDR...WHO MIGHT
BE MORE LIKE 10-11Z OR SO. STRATUS LOOKS TO LAST THROUGH THE
16-17Z TIME FRAME BEFORE LIFTING.
&&
.FIRE WEATHER...
ISSUED AT 332 AM MDT MON SEP 16 2013
WET WEATHER WILL FINALLY GIVE WAY TO DRIER CONDITIONS AS THE WEATHER
PATTERN SEES A SIGNIFICANT CHANGE. WILL START OF THIS MORNING WITH
SOME FOG AND DRIZZLE ALONG AND EAST OF THE SOUTHERN LARAMIE RANGE
AND INTO THE SOUTHERN NEBRASKA PANHANDLE BUT THE FOG WILL LIFT AS
DRIER AIR PUSHES IN FROM THE WEST. COULD SEE A FEW SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WITH THE MAIN CHANCES ALONG AND NEAR
THE MOUNTAINS OF SOUTHEAST WYOMING. CLEAR SKIES TO SET IN ACROSS THE
FORECAST AREA TONIGHT. A QUICK MOVING SYSTEM WILL APPROACH LATE
TUESDAY WITH WITH AFTERNOON SHOWERS AND THUNDERSTORMS POSSIBLE IN
THE WESTERN FORECAST AREA WITH DRY CONDITIONS EAST.
GUSTY WINDS TUESDAY NIGHT WEST OF THE LARAMIE RANGE WITH GUSTY WINDS
SPREADING ACROSS THE AREA WEDNESDAY. ABOVE NORMAL TEMPERATURES FOR
WEDNESDAY BUT THEN A COLD FRONT TO MOVE THROUGH WEDNESDAY NIGHT. A FEW
SHOWERS POSSIBLE WITH THE FRONTAL PASSAGE BUT CHANCES FOR WETTING RAINS
LOOKS MINIMAL AT THIS TIME.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...LIEBL
LONG TERM...FINCH
AVIATION...CLAYCOMB
FIRE WEATHER...LIEBL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
212 PM EDT MON SEP 16 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE AS A COLD FRONT APPROACHES FROM
THE NORTH. THE FRONT WILL CROSS THE AREA TONIGHT AND STALL JUST
SOUTH OF THE REGION ON TUESDAY. THE FRONT WILL REMAIN JUST SOUTH
OF THE AREA THROUGH FRIDAY WITH ANOTHER COLD FRONT CROSSING THE
REGION LATE IN THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL TROUGH CROSSING THE EASTERN STATES WILL PUSH A COLD
FRONT SOUTHWARD TOWARD THE AREA THIS AFTERNOON. A COLD FRONT
EXTENDED FROM VIRGINA WESTWARD THROUGH TENNESSEE AND MISSOURI EARLY
THIS AFTERNOON.
THE RUC MODEL INDICATING A WEAK SHORT WAVE CROSSING THE MIDLANDS
THIS AFTERNOON. THIS FEATURE WAS HELPING TO IGNITE CONVECTION OVER
THE EASTERN AND SOUTHERN MIDLANDS EARLY THIS AFTERNOON IN A
MODERATELY UNSTABLE AIRMASS. HAVE INCREASED POPS TO LIKELY ACROSS
THE SOUTHEAST...WITH SLIGHT CHANCE POPS FOR THE REMAINDER OF THE
AREA. ALSO NUDGED AFTERNOON HIGHS TO THE UPPER 80S AND LOWER 90S.
THE COLD FRONT WILL MOVE INTO THE AREA TONIGHT BRINGING ANOTHER
CHANCE OF SHOWERS AND THUNDERSTORMS WITH IT. THE BEST CHANCE FOR
PRECIPITATION WILL BE MAINLY THIS EVENING UNTIL AROUND MIDNIGHT.
OVERNIGHT LOWS WILL BE IN THE MIDDLE TO UPPER 60S.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
FRONT WILL BE JUST SOUTH OF THE AREA TUESDAY MORNING THEN SLIDE
INTO SOUTHERN GA AND STALL DURING THE AFTERNOON HOURS. THIS WILL
BRING SLIGHTLY DRIER AIR INTO THE MID LEVELS OVER THE
REGION...HOWEVER EASTERLY FLOW IN THE LOW LEVELS WILL KEEP
MOISTURE OVER THE AREA. THIS SCENARIO WILL REMAIN IN PLACE THROUGH
WEDNESDAY NIGHT AS HIGH PRESSURE CENTERED OVER THE NEW ENGLAND
STATES MOVES EASTWARD. EXPECT A CHANCE OF PRECIPITATION TUESDAY
MAINLY OVER THE SOUTHERN MIDLANDS AND CSRA WITH A MOSTLY DRY
FORECAST FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A WEAK UPPER-
LEVEL TROUGH MAY TRIGGER A FEW SHOWERS OVER THE CSRA TUESDAY
AFTERNOON. TEMPERATURES THROUGH THE SHORT TERM WILL BE IN THE
LOWER 80S FOR DAYTIME HIGHS WITH UPPER 50S TO LOWER 60S FOR
OVERNIGHT LOWS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
MODELS HAVE RECENTLY COME INTO BETTER AGREEMENT WITH THE MAIN
DIFFERENCES SURROUNDING A COLD FRONT EXPECTED TO ARRIVE LATE IN
THE WEEKEND. WEAK FRONTAL BOUNDARY WILL REMAIN JUST SOUTH OF THE
FORECAST AREA THURSDAY THEN BEGIN TRACKING NORTHWARD AS DEEPENING
LOW PRESSURE TRACKS ACROSS THE NORTHERN PLAINS AND PUSHES A COLD
FRONT SOUTHWARD INTO THE SOUTHERN PLAINS. BY FRIDAY A WELL
DEFINED COLD FRONT WILL PUSH THROUGH THE MID MS VALLEY. ALTHOUGH
MODELS DIFFER ON TIMING OF COLD FRONT INTO THE MIDLANDS EXPECT
ARRIVAL LATE SUNDAY...WITH MODELS INDICATING POTENTIAL FOR THE
FRONT TO STALL JUST SOUTH OF THE AREA. WITH SOME QUESTION AS TO HOW
FAR SOUTH THE FRONT MAY STALL...WILL KEEP A SMALL CHANCE POP INTO
MONDAY. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
LINE OF CONVECTION WILL AFFECT OGB THROUGH 20Z...OTHERWISE VFR
CONDITIONS THROUGH THE EARLY EVENING. DOWNSLOPE FLOW WILL INHIBIT
AFTERNOON CONVECTION AT CAE/CUB/AGS/DNL.
A COLD FRONT WILL MOVE ACROSS THE REGION TONIGHT WITH A FEW SHOWERS
AND THUNDERSTORMS 17/00Z-17/06Z. ALSO...LIGHT WINDS AND MOIST AIR
MASS AHEAD OF THE FRONT COULD ALLOW MVFR OR LOWER VSBYS IN FOG TO
DEVELOP AT AGS/OGB OVERNIGHT. INCREASING NORTHEAST WINDS AND DRIER
AIR BEHIND WILL BRING VFR CONDITIONS THROUGH THE END OF THE TAF
PERIOD.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1250 PM CDT MON SEP 16 2013
.DISCUSSION...
1050 AM CDT
FOR MORNING UPDATE...
MINOR CHANGES TO GOING FORECAST TO REMOVE MENTION OF LAKE EFFECT
PRECIP THIS MORNING...AND TO TWEAK HOURLY TEMPS AND CLOUD COVER.
SURFACE HIGH PRESSURE OVER THE NORTHERN GREAT LAKES REGION WILL
DRIFT SOUTHEAST THROUGH TONIGHT...IN THE WAKE OF MID-LEVEL SHORT
WAVE PROPAGATING THROUGH THE EASTERN GREAT LAKES AND UPPER OHIO
VALLEY. 12Z RAOB ANALYSIS INDICATES SUBSTANTIAL DRY AIR IN THE
MID/UPPER LEVELS ACROSS THE REGION...WHILE LOW LEVEL MOISTURE WAS
MORE ABUNDANT BENEATH 850MB...WITH CONSIDERABLE CLOUD COVER NOTED
IN SATELLITE IMAGERY OVER LOWER MICHIGAN/INDIANA AND CENTRAL IL.
SUBSIDENCE/RISING HEIGHTS IN THE WAKE OF THE EASTERN GREAT LAKES
SHORT WAVE IS DEPICTED IN FORECAST SOUNDINGS THROUGH GRADUALLY
LOWERING INVERSION...WHICH SHOULD CONTINUE TO THIN/DECREASE CLOUD
COVER ACROSS THE REGION. GOES VISIBLE IMAGERY ALREADY INDICATES
STRATOCUMULUS IS FAIRLY SHALLOW...WITH MODIFIED SOUNDINGS OVER THE
WATER NOT PARTICULARLY FAVORABLE FOR PRECIPITATION WITH STRONG
INVERSION AROUND 3500 FT AGL. EXPECTATION IS THAT STRATOCU WILL
CONTINUE TO THIN OVER THE LAKE AND DOWNSTREAM ACROSS CHICAGO METRO
AREA...THOUGH SOME FLAT CU/STRATOCU DEVELOPMENT WILL OCCUR OVER
LAND AREAS AS TEMPS RISE. THICKEST CLOUD COVER OVER LOWER MICHIGAN
AND NORTHWEST INDIANA WILL BE A LITTLE SLOWER TO THIN/ERODE...BUT
SHOULD ALSO SEE A GRADUAL DOWNWARD TREND IN THICKNESS/COVERAGE.
TEMPS WILL REMAIN A LITTLE COOL EVEN IN SUNNIER AREAS...WITH LOW
LEVEL THERMAL ANALYSIS SUPPORTING TEMPS FROM UPPER 60S/AROUND 70
WELL WEST/SOUTH...AND LOW-MID 60S CLOSER TO THE LAKE WHERE ONSHORE
WINDS WILL KEEP THINGS A BIT COOLER.
RATZER
//PREV DISCUSSION...
307 AM CDT
THE PRIMARY FOCUS OF THE FORECAST WAS ON TIMING CLOUD DISSIPATION
TODAY AND THEN THUNDER CHANCES AND DEGREE OF WARM-UP DURING THE
TUE NIGHT-FRI TIME FRAME.
SYNOPSIS...A GENERAL LONG WAVE TROUGH CONTINUES OVER EASTERN
NORTH AMERICA WITH A RE-ESTABLISHING MID-LEVEL WAVE HAVING
PASSED THROUGH THE GREAT LAKES LAST NIGHT. DESPITE THE SURFACE
WIND SHIFT TO NORTHERLY HAVING HAPPENED LAST EVE...THE TRUE LOW-
LEVEL COLD AIR ADVECTION IS ACTUALLY UNFOLDING EARLY THIS MORNING
ACROSS THE REGION...WITH SEVERAL SITES ESPECIALLY NEAR THE LAKE
GUSTING TO 25 MPH FROM THE NORTHEAST. SATELLITE IR AND 11-3.9
MICRON CHANNELS INDICATE LAKE EFFECT STRUCTURE TO THE CLOUDS FROM
MID-LAKE SSW INTO ADJACENT LAKE COUNTIES OF THE FORECAST AREA.
SCATTERED LIGHT SHOWERS/SPRINKLES HAVE BEEN SEEN ON TDWRS WITHIN
THIS. ELSEWHERE...AREAS OF COLD AIR ADVECTION STRATUS/STRATOCU ARE
NOTED OVER THE REGION. THE SURFACE HIGH IS CENTERED OVER NORTHERN
WI AND THE ARROWHEAD OF MN...WHERE SCATTERED SUB-FREEZING
TEMPERATURES ARE SEEN THIS MORNING.
TODAY...THE SURFACE HIGH WILL BASICALLY MOVE DUE EAST TODAY WITH
A PRESSURE GRADIENT HOLDING ITS OWN OVER THE FORECAST AREA
YIELDING NOT MUCH CHANGE IN WIND ORIENTATION OR SPEED. THIS SHOULD
CONTINUE HIGH WAVES ALONG IL SHORES AND KEEP LAKESIDE TEMPS IN THE
MID 60S OR SO BASED ON OBSERVED AND ESTIMATED WATER TEMPERATURES.
A SCATTERING OF THE SYNOPTIC CLOUDS IS EXPECTED BY LATE MORNING
INTO AFTERNOON...WHILE THE PLUME OF LAKE EFFECT CLOUDS IS LIKELY
TO KEEP SOME PARTS OF THE CHICAGO METRO CLOUDY INTO EARLY
AFTERNOON. THE VARIOUS WRF COLUMN CONDENSATE FORECASTS INDICATE
THIS CHANNEL OF CLOUDS SHIFTING WEST SOME BUT MAINLY HOLDING
TOGETHER THROUGH THE MORNING WHICH SEEM REASONABLE PER FORECAST
SOUNDINGS. AN AMDAR SOUNDING BACK FROM 05Z HAD AN EQUILIBRIUM LEVEL
AROUND 6000 FT AND NOT SEEING MUCH CHANGE AT ALL IN THAT THROUGH
THIS MORNING. SOME LIGHT LAKE EFFECT SHOWERS OR SPRINKLES WILL
PROBABLY HANG IN THERE THROUGH THE MORNING...MAINLY IN LAKE
IL...COOK...AND DUPAGE COUNTIES. CONSIDERING LOCAL CLIMATOLOGY FOR
THE 850MB AND 925MB TEMPERATURES AND THE ANTICIPATED INCREASE IN
SUN BY AFTERNOON...MID TO UPPER 60S IN CHICAGO AND AROUND 70
ELSEWHERE ARE EXPECTED FOR HIGHS.
TUESDAY NIGHT-THURSDAY...AFTER QUIET WEATHER INTO TUESDAY...UPPER
HEIGHTS THEN FURTHER BUILD IN THIS PERIOD AS A RIDGE OVER THE
PLAINS SHIFTS EAST. A LOOSELY DEFINED UPPER LOW OVER EASTERN CO
THIS MORNING /PARTIAL REMNANTS OF THE SIGNIFICANT ONE THAT PRODUCED
RECORD CO FLOODING LAST WEEK/...IS FORECAST TO MOVE ENE AS A SHORT
WAVE UNDER THIS RIDGE. THIS WILL LINE UP WITH SOME BETTER ELEVATED
WARM AIR ADVECTION AND MOIST RETURN LATER TUESDAY NIGHT INTO
WEDNESDAY. GUIDANCE STILL HAS SOME NOTABLE DISCREPANCIES IN
EVOLUTION OF ANY CONVECTION TUE NIGHT INTO WED MORNING...BUT
THICKNESSES AND MOISTURE TRANSPORT FIELDS WOULD POTENTIALLY
SUPPORT FADING CONVECTION MOVING EAST TO SOUTHEAST INTO THE
FORECAST AREA IF SOME CAN INITIALIZE ON THE LLJ TO THE WEST. AFTER
THAT...ANY UPPER FOCUS CONTINUES TO LOOK ILL-DEFINED AS THE
FORECAST AREA LOOKS TO BE IN A WARM SECTOR BY THURSDAY. WHILE
MODELS ADVERTISE QPF WEDNESDAY AFTERNOON-THURSDAY AND CANNOT RULE
OUT SOME SCATTERED CONVECTION...IT WOULD SEEM THEY REMAIN OVERDONE
AND HAVE GONE BELOW A GUIDANCE BLENDED POP. FOR TEMPS...WEDNESDAY
IS A CHALLENGE BASED ON POTENTIAL PRECIP...AND HAVE NOT SWAYED
MUCH FROM THE GOING FORECAST. THE WARMEST READINGS LOOK TO BE ON
THURSDAY WITH MODEST CONFIDENCE OF 80 PLUS OVER MUCH OF THE CWA
GIVEN SUPPORT OF LOCAL CLIMATOLOGY AND BIAS-CORRECTED
GUIDANCE...WHICH HAS WORKED WELL IN THE WARM STRETCHES DURING THE
PAST MONTH.
THURSDAY NIGHT-FRIDAY...LONG RANGE GUIDANCE IS IN GOOD AGREEMENT
OF AN UPPER WAVE MOVING ALONG THE CANADIAN BORDER IN THIS PERIOD
WITH AN ASSOCIATED SURFACE COLD FRONT MOVING THROUGH THE FORECAST
AREA. FORCING FOR CONVECTIVE PRECIP IS THERE ON ALL GUIDANCE BUT
CAN LIKELY EXPECT TO SEE SOME TIMING SHIFTS. HAVE LIKELY POPS
AREAWIDE THU NIGHT FOR NOW. GFS PWAT AND MOISTURE TRANSPORT
PROJECTIONS DO INDICATE THAT SOME OF THE DEEP MOISTURE FROM TROPICAL
STORM INGRID GETS WRAPPED INTO PART OF THE SYNOPTIC WARM
SECTOR...THOUGH IT DOES NOT APPEAR TO TRAVERSE THIS FAR NORTH.
SOMETHING CERTAINLY TO KEEP AN EYE ON THOUGH FOR MORE EFFICIENT
RAINFALL PRODUCTION.
BEYOND...WITH THE JET STREAM TO THE NORTH AND THE PATTERN
REMAINING PROGRESSIVE...TEMPERATURES LOOK TO BE AROUND NORMAL OR
JUST A TAD BELOW NEXT WEEKEND. ALSO GIVEN THE CURRENT TIMING OF
SYSTEMS IT WOULD LOOK TO BE DRY AS WELL.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* POSSIBLE SPORADIC VFR CEILINGS OVER THE NEXT 1-2 HOURS.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
WITH HIGH PRESSURE BUILDING ACROSS THE REGION...QUIET CONDITIONS
ONGOING AT THE TERMINALS. LATEST SATELLITE IMAGERY DEPICTING CLOUD
COVER DECREASING IN COVERAGE EARLY THIS AFTERNOON...AND EXPECT
THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON.
ALTHOUGH VFR CEILINGS WILL BE POSSIBLE EARLY...EXPECT THE
PREVAILING CONDITION TO BE MORE SCT AND HAVE THE TAFS REPRESENTING
THESE CONDITIONS. HIGH LEVEL CLOUD COVER WILL THEN BE THE ONLY
CLOUDS EXPECTED THROUGH THE REST OF THE FORECAST PERIOD. NORTHEAST
WINDS GUSTING TO THE UPPER TEENS WILL PREVAIL THIS
AFTERNOON...THEN DIMINISH WHILE SHIFTING MORE EAST SOUTHEAST
TONIGHT INTO EARLY TUESDAY MORNING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE WITH VFR CONDITIONS.
* HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. CHANCE SHRA LATE.
WEDNESDAY AND THURSDAY...CHANCE SHRA/TSRA...OTHERWISE VFR.
FRIDAY...CHANCE SHRA EARLY. COLD FRONTAL PASSAGE EARLY WITH SHARP
WIND DIRECTION SHIFT FROM SLY TO NWLY.
FRIDAY NIGHT THROUGH SUNDAY...VFR. WX NIL.
KREIN
&&
.MARINE...
307 AM CDT
STRONG HIGH PRESSURE CONTINUES TO SPREAD INTO THE UPPER GREAT
LAKES AS THE COLD FRONT PUSHES INTO THE OHIO VALLEY. A SECONDARY
SURGE OF COOLER AIR SPREADING DOWN THE LAKE HAS HELPED INCREASE
WINDS TO AROUND 30KT THROUGH THE EARLY MORNING HOURS. AS THE THE
CENTER OF THE HIGH SLIDES TO THE SOUTHEAST INTO THE EASTERN GREAT
LAKES MONDAY NIGHT...THE GRADIENT WILL RELAX...ALLOWING WIND
SPEEDS TO DECREASE AND DIRECTION TO VEER FROM GENERALLY NORTHERLY
TODAY TO SOUTHERLY BY TUESDAY MORNING. THE SOUTH WINDS WILL
PERSIST THROUGH THURSDAY AND THEN VEER MORE SOUTHWESTERLY BY
FRIDAY AS DEEP LOW PRESSURE MOVES INTO SOUTH CENTRAL CANADA AND A
STRONG COLD FRONT APPROACHES THE UPPER MISSISSIPPI VALLEY.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 PM TUESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001 UNTIL 4 PM TUESDAY.
BEACH HAZARDS STATEMENT...INZ002 UNTIL 10 PM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 4 PM
TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 11 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1226 PM CDT Mon Sep 16 2013
.DISCUSSION...
ISSUED 1000 AM CDT Mon Sep 16 2013
Stratocumulus deck continues to thin out over a good part of
central Illinois this morning, with the northern edge basically
along I-74 from Galesburg to near Bloomington. However, some
higher clouds evident in satellite imagery spreading eastward over
the state. Cu-rule off the RAP model continues to show some
erosion of the lower cloud deck as drier air advects in from the
northeast.
Have sent some updated grids to bump up the winds and adjust the
dew points a bit. Temperatures still look good. The changes do not
require a change to the zone forecasts at this point.
Geelhart
&&
.AVIATION...
ISSUED 1225 PM CDT Mon Sep 16 2013
MVFR ceilings around 2500 feet still trying to fully break apart
from KSPI eastward to KCMI, but this may take a couple more hours
as areas near KPIA/KBMI are currently on the verge of losing all
of the lower clouds. Still will see high clouds streaming through
once the lower clouds scatter out. Gusty northeast winds will
begin to settle down in a few hours, then gradually swing to the
southeast late tonight and early Tuesday as high pressure pushes
further east across the Great Lakes. On Tuesday, concern shifts
toward an incoming upper disturbance from the west which will
bring some showers. However, latest model guidance pretty much
keeps any rain threat to the west of the TAF sites most of the
day. VFR ceilings will gradually lower ahead of this system, but
still remain well above 10KFT through 18Z.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 257 AM CDT Mon Sep 16 2013
Cold front has moved through the FA this morning...stretching
along the Ohio River Valley while cooler air moves into place for
much of the Midwest. Northeasterly winds have settled in as a
surface high pressure, centered in northern MN, builds back into
the Midwest. Persistent upper level ridging over the Rockies and
the high plains providing a source of warming later in the
forecast...but for the next couple of days the temperatures are
rather cool. Into the remainder of the week, the forecast becomes
problematic almost immediately with a return of pops and a lack of
consistency in operational models. Low chance pops dominate
between a shortwave moving through Tuesday night/Wednesday and an
actual front on Thu night/Friday. On the other side of Friday
night...next weekend dries back out. Though breaks in the rain is
expected between Wednesday afternoon and Thursday night, models are
filling the gap with low pops.
SHORT TERM...Today and tomorrow...
Slow drying out behind the boundary with cooler temps expected
today. Clearing of clouds slowly as high pressure builds into the
region. Some clearing to the NW will work into the region...though
plenty of remnant clouds will move in from the SW and convection
behind the front in MO. Variable clouds through the day will
dissolve into the evening hours, clearing out and assisting
efficient radiational cooling and a temp drop into the 50s.
Tomorrow the winds get a small southerly component and the general
moderation of the air mass begins and temperatures start to climb a
couple degrees. That being said, clouds should be on the increase
so cooling tomorrow night should be impeded by the increasing
cloud cover. Pops return to forecast tomorrow afternoon in the
east and into the overnight, although concern for speed of onset of
QPF in general with the wave moving much faster in 00Z runs.
LONG TERM...Wednesday through Sunday...
Temperatures moderating somewhat by Wednesday due to a eastward
trending of the western mid level thermal ridge. Expect some
variability in the guidance as the portrayal of the next system
becomes clearer, right now being torn between the warmth under the
ridge and the threat of advancing rain. Pops move in Tues night
and continue through Friday with a lack of consistency for GFS and
ECMWF, as a result muddying the AllBlend. In addition, models
attempting a slow progression of initial wave and create an
interaction between remnant energy aloft and developing boundary
as another upper trof pushes into the region. Both ECMWF and GFS
fill the gap with pops across the board, so the AllBlend follows
suit. GFS and ECMWF are alternating being the most aggressive with
the strength and depth of the wave...and the QPF as well. For now,
the forecast remains rather diffuse and generous with the pops.
Best chances for precipitation beyond Wednesday looks to be in the
Thursday night/Friday time frame, associated with a cold front as
an aggressive trof digs in over the upper Midwest.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
318 PM CDT MON SEP 16 2013
.SYNOPSIS...
ISSUED AT 317 PM CDT MON SEP 16 2013
LATEST SFC ANALYSIS WAS INDICATING HIGH PRESSURE DOMINATING THE
WESTERN GRT LKS AND UPPER MS RVR VALLEY. SUBSIDENCE FROM THE HEART
OF THIS FEATURE AND UPPER LEVEL RIDGING HELPING ERODE STRATOCU
FIELDS IN THE CWA...BUT SOME CLOUD FIELDS HOLDING FIRM ACRS SOUTH
CENTRAL INTO SOUTHEASTERN IA. ALOFT...WATER VAPOR IMAGERY WAS
INDICATING LINGERING MONSOONAL MOISTURE FIELDS ACRS THE CENTRAL
PLAINS OVER TO THE OH RVR/TN VALLEY REGIONS...WHILE MOISTURE OFF
INGRID SURGES INLAND ACRS MEX/SOUTHERN TX. UPSTREAM WAVE NOTED
ACRS THE NORTHWEST PLAINS ON WESTERN FLANK OF UPPER RIDGE AXIS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 317 PM CDT MON SEP 16 2013
TONIGHT...WILL FOLLOW LATEST RAP LLVL MOISTURE/RH GUIDANCE WHICH
SUGGESTS A CONTINUED CLEARING OF THE STRATOCU EXCEPT MAYBE THE FAR
SOUTHWESTERN CWA THROUGH THIS EVENING. IT ALSO SUGGESTS LLVL FLOW
TO VEER TO THE EAST-SOUTHEAST OVERNIGHT AND POSSIBLY START ADVECTING
MORE HIGHER RH LEVELS/STRATOCU FROM SOUTHEAST IL/IND LATE TONIGHT
AFTER MIDNIGHT. FOR NOW WILL MAINTAIN MOSTLY CLR SKIES OVERNIGHT
FOR BULK OF THE EASTERN HALF OF THE CWA AND BANK ON COOL LOWS IN THE
40S WITH LOW/DRY AMBIENT SFC DPTS. BUT SOME BUST POTENTIAL ON THE LOW
SIDE IF THE CLOUDS DO ADVECT IN FROM THE EAST LATER TONIGHT ALONG
WITH HIGHER DPTS FROM THOSE SAME AREAS. WILL KEEP LOWS IN THE LOW TO
MID 50S IN THE SOUTHWEST THIRD WITH EXPECTED MID DECK/HIGHER CLOUD
INCREASE LATER TONIGHT FROM THE SOUTHWEST IN THOSE AREAS. ELEVATED
WARM AIR ADVECTION PROCESSES ASSOCIATED WITH RIDGE-RIDING WAVE
MENTIONED ABOVE PUSHING ACRS EASTERN NEB AND WESTERN IA TO TAP IN THE
LINGERING MONSOONAL MOISTURE AND PRODUCE SHOWERS OVERNIGHT...BUT
RIDGING AND DRY AIR IN PLACE TO MAKE FOR MOST OF THE CWA REMAINING
DRY THROUGH 12Z TUE. MUCH OF INITIAL LIFT FROM APPROACHING UPPER WAVE
TO GO INTO TOP-DOWN SATURATION PROCESSES WITH VIRGA TO LIGHT
SHOWERS/SPRINKLES ACRS THE SOUTHWEST THIRD TOWARD DAYBREAK.
TUESDAY...DESPITE SOME DECENT MODEL INDICATED ELEVATED THTA-E
ADVECTION AND CONVERGENT REGIONS PUSHING ACRS THE SOUTHWESTERN
THIRD TO HALF OF THE DVN CWA AS THE DAY PROGRESSES...THE BATTLE
WILL BE ON WITH LARGE DRY AIRMASS TO THE EAST. LIKE THE PREVIOUS
SHIFT MENTIONED...SHARP MOISTURE AND PRECIP GRADIENTS MAY DEVELOP
LOCALLY WITH SOME AREAS/IN THE FAR SOUTHWEST/ GETTING UP TO A
QUARTER INCH OF RAIN BY MID AFTERNOON...AND AREAS EAST OF THE MS RVR
ESPECIALLY EAST CENTRAL AND NORTHEAST REMAINING DRY THROUGH 00Z WED.
WILL SPREAD IN POPS GENERALLY FROM WEST-SOUTHWEST TO EAST IN
DECREASING FASHION TUE. BUT SOME AREAS PROBABLY WARRANT CATEGORICAL
POPS WEST OF THE MS RVR. EXPECT MAINLY SHOWERS IN DECLINING FASHION
AS THEY SPREAD EASTWARD AND ENCOUNTER THE DRY AIR...BUT PROGGED
MID LEVEL MUCAPES OF 200-500 J/KG IF CORRECT...SUPPORTS ISOLATED
EMBEDDED THUNDER IN THE SOUTHWESTERN HALF ON TUE. TEMPS WILL BE A
CHALLENGE TUE DEPENDING ON CLOUD COVER AND EVAPO-COOLING FROM
PRECIP. WILL GO WITH COOLER VALUES HELD DOWN IN THE 60S IN THE
WEST WITH EARLIER ARRIVAL OF CLOUDS AND PRECIP...WARMER IN THE LOW
70S EAST OF THE MS RVR. ..12..
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 317 PM CDT MON SEP 16 2013
ACTIVE WX WILL BE SEEN ACROSS THE MIDWEST FOR THE REMAINDER OF THE
WORK WEEK WITH SEVERAL CHANCES FOR RAIN.
RAIN THAT MOVES INTO THE AREA TUESDAY AFTERNOON WILL OVERSPREAD THE
AREA TUESDAY NIGHT/WED. AS THE OVERALL FORCING WEAKENS ON WEDNESDAY
THE AREAL COVERAGE OF PRECIPITATION WILL DECREASE WEDNESDAY
AFTERNOON.
WED NIGHT/THURSDAY THE NEXT ROUND OF FORCING MOVES THROUGH THE AREA
HELPING TO RE-DEVELOP NEW CONVECTION. A RESPECTABLE LLJ DEVELOPS WED
NIGHT WHICH SHOULD RESULT IN CONSIDERABLE NOCTURNAL CONVECTION AFTER
MIDNIGHT AND INTO THURSDAY MORNING.
THE APPROACHING COLD FRONT ON THURSDAY IS EXPECTED TO HELP MAINTAIN
CONVECTION DURING THE AFTERNOON. THE AMOUNT OF CLOUD COVER MAY HOLD
DOWN TEMPERATURES SOMEWHAT BUT THEY SHOULD STILL BE CLOSE TO NORMAL.
THURSDAY NIGHT ON...
THE MODEL CONSENSUS HAS HIGH CHC/LIKELY POPS FOR THURS NIGHT AS THE
NEXT FRONT MOVES THROUGH THE AREA. THE FRONT WILL CLEAR THE AREA ON
FRIDAY SO ONLY SCHC/LOW CHC POPS ARE GIVEN BY THE MODEL CONSENSUS
FOR THE EASTERN HALF OF THE CWFA.
COOL CANADIAN HIGH BUILDS INTO THE GREAT LAKES FOR FRIDAY NIGHT
THROUGH SUNDAY NIGHT. THE MODEL CONSENSUS GIVES DRY CONDITIONS WITH
TEMPERATURES AVERAGING BELOW NORMAL.
SOUTHERLY FLOW DEVELOPING ON MONDAY WILL ALLOW TEMPERATURES TO AGAIN
WARM. THE MODEL CONSENSUS HAS DRY CONDITIONS FOR MONDAY WITH CHC
POPS FOR MONDAY NIGHT. ..08..
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1226 PM CDT MON SEP 16 2013
DRYING SUBSIDING AIR SLOWLY PUSHING IN FROM THE WEST CLEARING MVFR
STRATOCU AT MLI/DBQ...BUT MAY TAKE 1-2 MORE HRS AT CID/BRL BEFORE
CIGS SCATTER OUT OR CLEAR. SOME CONCERN MVFR BKN-OVC CIGS AT CID
MAY HOLD ON UNTIL AFTER 3 PM CDT THIS AFTERNOON. OTHERWISE EXPECT
MAINLY CLEAR SKIES OVERNIGHT WITH LIGHT EASTERLY SFC WINDS.
HOPEFULLY ENOUGH LOWERING OF SFC DPTS AND SFC WIND MAINTENANCE TO
LIMIT FOG POTENTIAL AND WILL LEAVE OUT OF TAFS FOR NOW...BUT SOME
MVFR FOG POSSIBLE AT DBQ/MLI/CID AFTER 06Z TONIGHT. NEXT SYSTEM
WILL THEN APPROACH OUT OF THE PLAINS AND BRING THICKENING CLOUDS
MAINLY VFR LATE TONIGHT INTO TUE MORNING. SHORT RANGE MODELS
VARY ON IF SOME ELEVATED/HIGH BASED SHOWERS GET IN THE VCNTY OF
BRL AND CID FROM THE WEST BY MID TO LATE TUE MORNING. FOR NOW WILL
LEAVE OUT MENTION IN THE TAFS BUT LATER AVIATION FCSTS WILL HAVE
TO BETTER DEFINE INCOMING PRECIP WINDOWS FOR TUE. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...12
SHORT TERM...12
LONG TERM...08
AVIATION...12
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1211 PM EDT MON SEP 16 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD INTO THE AREA THIS EVENING...UNTIL
SO LOOK FOR CLOUDS TO HANG AROUND. DRY AND SEASONAL WEATHER TAKES
HOLD THROUGH MID WEEK. A COLD FRONT WILL CROSS LATER THIS WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS HAVE QUICKLY FILLED IN DUE TO AN AUTO CONVECTIVE
ATMOSPHERE. LATEST HRRR COINCIDES WELL WITH THE REGIONAL RADAR
MOSAIC WITH ISOLD - SCT RW DROPPING S FROM LAKE ERIE. ISOLD
SHOWERS ARE POSSIBLE IN THE I-80 AREA THROUGH LATE AFTN. FARTHER
S...DO NOT EXPECT ANY MEASURABLE QPF SO WILL CARRY SPRINKLES. RUC
SOUNDINGS ILLUSTRATE MARGINAL INSTABILITY GIVEN LAKE DELTA TS.
INVERSION HEIGHT LOWERS TO 4-5KFT DURING THE DAY OFFSETTING ANY
LAKE INDUCED INSTABILITY. TEMPS ON TRACK WITH NO CHANGES PLANNED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE SHRTWV IS PROGGED TO EXIT THE RGN THIS EVE. STILL SOME QN ON
HOW LONG THE STRATOCU WILL REMAIN ACRS THE AREA. KEPT MCLDY SKIES
INTO THE EVE WITH A GRDL CLRG TREND OVRNGT AS THE FLOW BECOMES
NERLY AND SBSDNC INCRS WITH BLDG HIGH PRES. THE HIGH WL SHIFT EWD
WED WRM AIR ADVCTN BRINGING A GRDL INCRS IN CLDS LT IN THE DAY.
SHWR/TSTM CHCS WL INCR WED NGT AND THU AS A SHRTWV MOVES ACRS THE
GT LKS/OH VLY RGN. EXP LOWS TNGT AND TUE NGT FM UPR 30S/NR 40 N TO
MD 40S S...WHICH SHOULD PRECLUDE ANY FROST MENTION IN THE FCST.
EXP TEMPS TO MODERATE TO NR OR ABV SEASONAL AVGS BY MD WK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
RAIN CHCS WL INCRS DURING THE LATTER HALF OF THE WEEK AS MDLS ARE
IN AGRMNT IN SCENARIO OF A DEEPENING TROF WITH ITS ADVN ACRS THE
GREAT LAKES. CURRENT GFS AND ECMWF TIMING SUGGESTS CDFNT/UPR TROF
AXIS PASSAGE FOR SATURDAY...HENCE THE DRYING TREND DEPICTED FOR
THE START OF THE NEW WEEK.
WARM ADVCTN IN ADVN OF THAT TROF WL LIKELY SPPRT TEMPS AOA THE
SEASONAL AVERAGES UNTIL FRONTAL PASSAGE. WPC GUIDANCE GENL DEPICTS
THIS AND WAS UTILIZED WITH MINIMAL VARIATION.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
A CDFNT WL COMPLETE PASSAGE ACRS THE UPR OH REGION THIS MRNG
ACCOMPANIED BY A BROAD SWATH OF LOW AND MID LVL CLDINESS WITH RESIDUAL
LGT SHWRS. MOIST BNDRY LYR FM LAST NGTS RAIN WL SPPRT ISOLD AREAS
OF IFR VSBY AND ST...WHICH WL MIX OUT RAPIDLY AFTR DAYBREAK.
MVFR STRATOCU IS EXPECTED TO PERSIST THROUGH THE MRNG...BUT DRY
ADVCTN...SBSDNC...AND DVLPG NNE COMPONENT TO THE SFC WIND SHOULD
SPPRT VFR BY AFTN. BLDG HIGH PRES WL THEN MAINTAIN THAT CONDITION
THROUGH TNGT.
.OUTLOOK.../TUESDAY THROUGH FRIDAY/...
SHWRS WITH A THURSDAY WARM FRONT WL BRING THE NXT CHC FOR GENL RESTRICTIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...98
NEAR TERM...98
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
107 PM EDT MON SEP 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 513 AM EDT MON SEP 16 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE WESTERN GREAT LAKES BETWEEN A RIDGE OVER THE PLAINS AND A
TROUGH OVER ERN CANADA. STRONG 700-300 MB QVECTOR DIV IN THE WAKE OF
A SHORTWAVE TROUGH MOVING INTO NEW ENGLAND HAS BROUGHT CLEARING SKIES
OVER MOST OF THE REGION AS A 1030 MB SFC HIGH OVER NW ONTARIO AND NRN
MN BUILDS INTO UPPER MI. HOWEVER...LINGERING NE 10 TO 15 KNOT WINDS
OVER ERN LAKE SUPERIOR ALONG WITH 850 MB TEMPS NEAR 0C HAS GENERATED
LAKE CLOUDS THAT HAVE SPREAD INTO PORTIONS OF NRN UPPER MI. THIS
ALONG WITH CONTINUED LIGHT NE WINDS HAVE KEPT TEMPS FROM DROPPING OFF
AS MUCH OVER THE NORTH AND EAST COMPARED TO INLAND LOCATIONS OVER THE
WEST WHERE READINGS INTO THE LOWER 30S WERE COMMON.
TODAY...EXPECT DAYTIME HEATING/MIXING AND CONTINUED DRY ADVECTION TO
HELP SCOUR OUT THE EARLY MORNING CLOUDS WITH MOSTLY SUNNY CONDITIONS
THEN PREVAILING. THE ABUNDANT SUNSHINE WILL HELP PUSH TEMPS TO NEAR
60 THIS AFTERNOON.
TONIGHT...THE SFC HIGH CENTERED JUST EAST OF THE FCST AREA WILL
CONTINUE TO DOMINATE THE REGION WITH A DRY AIRMASS IN PLACE. ANOTHER
NIGHT WITH VERY FAVORABLE RADIATIONAL COOLING CONDITIONS WILL AGAIN
RESULT IN AREAS OF FROST. THE LOWEST READINGS ARE EXPECTED INTO THE
CNTRL AND ERN PORTION OF THE CWA WHERE THE WINDS WILL BE LIGHTEST.
SOME INCREASE IN SRLY WINDS OVER THE FAR WEST AND DOWNSLOPE
LOCATIONS NEAR LAKE SUPERIOR FROM DEVELOPING LAND BREEZE
SHOULD KEEP TEMPS CLOSER TO 40. SINCE THERE IS ALREADY AN ONGOING
FROST ADVISORY...A NEW ONE FOR TONIGHT WAS NOT POSTED AT THIS TIME TO
AVOID CONFUSION EVEN THOUGH ANOTHER ADVISORY FOR TONIGHT WILL LIKELY
BE NEEDED.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 327 AM EDT MON SEP 16 2013
VERY CONVOLUTED FORECAST FOR MID TO LATE WEEK AS MODELS STRUGGLE WITH
AGREEMENT BETWEEN MODELS AND RUN TO RUN CONTINUITY WITH A SYSTEM
PROGGED TO MOVE ACROSS THE NRN CONUS. THE SHORTWAVE THAT THE SYSTEM
WILL EVOLVE FROM IS CURRENTLY ANALYZED BY MODELS TO BE ABOUT 15
DEGREES LONGITUDE WEST OF THE ATLANTIC COAST OF WA/OR...SO THERE ARE
NOT ANY GOOD OBSERVATIONS OF THE MORE SUBTLE SHORTWAVE ENERGY...OR
EVEN THE DEEPER UPPER LOW/TROUGH THAT IT IS ROTATING AROUND. THE
POOR DATA FOR INITIALIZATION EXPLAINS...AT LEAST PARTIALLY...THE
MODEL DISAGREEMENT AND DISCONTINUITY...ESPECIALLY AFTER ADDITIONAL
ENERGY IS ADDED OVER THE NRN PLAINS THAT MAY CAUSE A RAPID DEEPENING
OF THE SYSTEM. THE SYSTEM AND ADDITIONAL SHORTWAVE ENERGY DOES NOT
MOVE FULLY INTO THE UPPER AIR OBSERVATION NETWORK UNTIL LATE
TUE/EARLY WED...SO IMPROVEMENTS TO CONFIDENCE MAY NOT HAPPEN UNTIL
THAT TIME. BASICALLY...THE SYSTEM JUST HAS THE POTENTIAL TO BRING
RAIN...COLDER TEMPS AND WINDS...BUT IT IS THE FIRST OF THE MORE
SIGNIFICANT DEEPER SYSTEMS OF THE SEASON.
BACK TO A MORE ORGANIZED DISCUSSION STARTING AT 12Z TUE...AN UPPER
LEVEL RIDGE WILL BE OVER THE CWA WITH A SHORTWAVE OVER THE CENTRAL
PLAINS. A SFC HIGH WILL BE CENTERED OVER THE LOWER GREAT
LAKES...WITH THE CWA BETWEEN THE HIGH AND A SFC LOW OVER CENTRAL
SASKATCHEWAN. NO PRECIP IS SHOWN BY MODELS TUE AND TUE NIGHT AS THEY
NOW KEEP THE SHORTWAVE WELL S OF THE CWA. WILL LOWER POPS FOR THIS
PERIOD. LOW LEVEL SW FLOW WILL INCREASE TUE AND TUE NIGHT BETWEEN
THE HIGH TO THE E AND LOW TO THE W...WITH INCREASING LOW LEVEL TEMPS
AS WELL.
FOR WED...MODELS HAVE THE AFOREMENTIONED DEEPER LOW PRESSURE SYSTEM
DEEPENING OVER THE DAKOTAS. SOME MODELS ALSO SHOW SHORTWAVE ENERGY
MOVE THROUGH THE CWA WED...AND CAN NOT RULE THIS OUT AT THIS TIME SO
WILL KEEP AT LEAST SLIGHT CHANCE POPS IN THE FORECAST. LOW LEVEL
TEMPS SHOULD INCREASE AGAIN ON WED...BUT HIGH TEMPS SHOULD BE
SIMILAR TO TUE /UPPER 60S TO AROUND 70/ DUE TO INCREASED CLOUD COVER.
WED NIGHT THROUGH SAT AND PARTIALLY INTO SUN IS WHEN MODEL SOLUTIONS
DIVERGE AND CONFIDENCE IS SIGNIFICANTLY REDUCED. MODEL SPREAD
INCLUDES THE 12Z/15 GEM AND 00Z/16 GFS IN BRINGING THE CLOSED OFF
LOW ACROSS ONTARIO TO JAMES BAY BY FRI NIGHT...DRAGGING THE COLD
FRONT ACROSS THE CWA LATE THU UNTIL FRI. THE 12Z/15 ECMWF IS FARTHER
S...DEEPENING THE LOW AS IT MOVES ACROSS THE CWA FRI NIGHT INTO SAT.
THIS REALLY THROWS OFF WINDS...TEMPS AND PRECIP AND OTHER ASSOCIATED
FIELDS. WILL GO WITH A CONSENSUS OF MODEL GUIDANCE AS IT IS
DIFFICULT AND FUTILE TO CHOOSE ANY ONE SOLUTION AT THIS TIME.
MODELS DO COME BACK INTO BETTER AGREEMENT SUN /ESPECIALLY LATER ON
SUN/ WITH BRINGING AN UPPER RIDGE AXIS TO NEAR THE CWA AND A SFC
RIDGE OVER THE CWA BY 00Z MON. AGAIN...WILL STICK WITH A CONSENSUS
OF GUIDANCE FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 107 PM EDT MON SEP 16 2013
LAKE EFFECT CLOUDS WILL CONTINUE TO DISSIPATE THIS AFTERNOON AS
DRIER AIR CONTINUES TO MOVE IN AND TEMPERATURES WARM. VFR CONDITIONS
ARE EXPECTED THROUGH THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 513 AM EDT MON SEP 16 2013
WITH SFC HIGH PRES BUILD INTO THE AREA TODAY AND LINGERING INTO
TONIGHT...WINDS WILL REMAIN AT OR BELOW 15 KNOTS. AS THE HIGH SHIFTS
TO THE EAST...SRLY WINDS UP TO 20 KNOTS ARE EXPECTED FROM TUE INTO
WED. WINDS SHOULD THEN REMAIN BELOW 20 KNOTS UNTIL FRI WHEN A TROUGH
MOVING THROUGH THE REGION BRINGS SW TO W WINDS TO AROUND 25 KNOTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GLASGOW MT
305 PM MDT MON SEP 16 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH WEDNESDAY...
QUIET EVENING EXPECTED WITH NORTHEAST MONTANA UNDER SOUTHWEST FLOW
ALOFT. HRRR HAS BEEN HINTING AT SOME SHOWER/THUNDERSTORM ACTIVITY
ENTERING WESTERN ZONES AND THIS HAS SUPPORT FROM THE LATEST NAM
AND GFS SOLUTIONS...ALTHOUGH ECMWF MAINTAINS DRY CONDITIONS. WILL
INCLUDE ISOLATED SHOWERS AND THUNDERSTORMS MAINLY FOR PETROLEUM
AND PHILLIPS COUNTIES. CANNOT RULE OUT POSSIBILITY INTO CENTRAL
PORTIONS OF THE CWA SO EXTENDED POPS A BIT FURTHER
EAST...HOWEVER...CONFIDENCE IS LOW. WILL EXPECT LITTLE MORE THAN
LEFTOVER CLOUD DEBRIS ACROSS MOST OF THE CWA OVERNIGHT IN THE FORM
OF HIGH CIRRUS. EXPECTING 850MB TEMPERATURES TO CONTINUE TO WARM
OVERNIGHT AND SO EXPECT MILDER LOWS TUESDAY MORNING AS COMPARED
WITH THIS MORNING. LASTLY...WILL KEEP AN EYE ON SURFACE WINDS WITH
THE LAKE WIND ADVISORY CONTINUING UNTIL 6PM. MOST MODEL GUIDANCE
INDICATES THAT WINDS WILL BEGIN TO RELAX WITHIN A FEW HOURS BUT
SPEEDS HAVE BEEN SUSTAINED AT OR ABOVE 20 MPH NOW FOR MUCH OF THE
DAY. AN UPDATE WILL BE SENT OUT IN A COUPLE OF HOURS WITH REGARD
TO THE GOING LAKE WIND ADVISORY.
TUESDAY THROUGH THURSDAY...UPPER TROUGH BEGINS TO TRANSLATE
EASTWARD ACROSS THE NORTHWEST AS ATTENTION TURNS TOWARD THE LOW
PRESSURE SYSTEM AS IT BEGINS TO AFFECT THE CWA. LATEST GFS AND
ECMWF ADVERTISE A DEEPENING SURFACE LOW WITH 997MB INTENSITY BY
WEDNESDAY AFTERNOON. NICE UPPER LEVEL DYNAMICS WILL COME INTO PLAY
WITH THE LOW PRESSURE SQUARELY WITHIN THE LEFT EXIT REGION OF THE
JET. THIS DEEPENING LOW WILL ALSO SERVE TO SHARPEN THE PRESSURE
GRADIENT ACROSS THE CWA AND SO INCREASED WINDS FOR THE PERIOD.
REGARDING PRECIPITATION CHANCES...CONCERNS SURROUND THE RAINFALL AMOUNT
WITH THIS SYSTEM AS THE TRACK OF THE SURFACE LOW IS STILL SOMEWHAT
UNCERTAIN. THE ECMWF AND GFS SHOW THE CENTER OF THE LOW TRACKING
ACROSS SOUTHEAST MONTANA AND THEN INTO NORTH DAKOTA AND EVENTUALLY
PUSHING INTO SOUTHERN MANITOBA. WOULD LIKE TO SEE THE TRACK A BIT
FURTHER SOUTH TO FEEL CONFIDENT IN WIDESPREAD WETTING RAINS AS
SUCH A TRACK LIKE WHAT IS PRESENTLY EXPECTED WOULD INTRODUCE
CONCERNS FOR A DRY SLOT SHUTTING OFF PRECIPITATION FOR A
TIME...ESPECIALLY ACROSS THE SOUTHERN AND SOUTHEASTERN ZONES NEAR
AND SOUTH OF THE TRACK. FURTHER NORTH NEAR THE INTERNATIONAL
BORDER...CONFIDENCE IS HIGHER ON STEADIER RAIN AND IN FACT
INTRODUCED THAT WORDING INTO THE GRIDS WITH SHOWERS FURTHER SOUTH
WHERE IT WILL BE MORE ISOLATED/SCATTERED IN NATURE.IN THE
STRATIFORM RAIN REGION DO EXPECT POTENTIAL EMBEDDED THUNDER AS
WELL DEPENDING ON MESOSCALE FORCING IN ADDITION TO LOCATION OF
BEST PVA AND UPPER LEVEL DYNAMICS. POSSIBILITY EXISTS IF THE CURRENT
FORECAST TRACK VERIFIES FOR SOME LOCATIONS TO PICK UP A RAINFALL
TOTAL EXCEEDING AN INCH BY THE END OF THE EVENT NEAR THE
INTERNATIONAL BORDER. WHILE STEADIEST RAINFALL WILL LIKELY BE
LOCATED NORTH OF THE MISSOURI RIVER...CANNOT RULE OUT THE
POSSIBILITY THAT FUTURE MODEL RUNS WILL SHIFT THE STORM TRACK
FURTHER SOUTH WHICH WOULD RESULT IN MORE WIDESPREAD WETTING RAINS.
LIKEWISE...SHOULD THE STORM TRACK FURTHER TO THE NORTH PER LATEST
NAM SOLUTION...MOST OF THE RAINFALL WOULD BE CONFINED TO SOUTHERN
SASKATCHEWAN AND MANITOBA...LEAVING THE CWA MAINLY DRY. NAM LOOKS
TO BE AN OUTLIER SOLUTION HOWEVER SO FOR NOW WILL DISREGARD THAT
SCENARIO. THE GOING FORECAST WILL LEAN TOWARD THE ECMWF/GFS/SREF
SOLUTIONS WITH GOOD CONSENSUS BEING SHOWN IN THE MODELS AND
CURRENT GRIDS NOW REFLECT LATEST THINKING. MALIAWCO
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
GOING FORECAST LOOKED GOOD BUT TO HELP WITH CONSISTENCY...ENDED
PRECIPITATION A BIT QUICKER THURSDAY. MODELS WERE HINTING AT
SLIGHTLY WARMER TEMPS ON THURSDAY AS WELL..SO RAISED THEM A COUPLE
DEGREES MOST PLACES.
LATE IN THE PERIOD...MODELS CONTINUE TO DISAGREE ABOUT SHOWERS
THAT FALL OUT FROM AN UPPER TROUGH. HAVE LEFT THIS PERIOD ALONE.
TFJ
PREVIOUS DISCUSSION...
THE EXTENDED BEGINS WITH AN ONGOING SYSTEM OVER THE NORTHERN
PLAINS AND CANADIAN PRAIRIES. THE MODELS ARE SIMILAR ON THE MAIN
FEATURES ON HOW THE SYSTEM DEVELOPS AND MOVES...HOWEVER
POSITIONING IS THE MAIN DIFFERENCE THROUGH THE PERIOD. WILL
CONTINUE TO SIDE WITH THE ECMWF FOR THE FORECAST TO FIT THE
FORECAST TREND.
THE EC/GEM ARE THE FASTEST ON GETTING THE PRECIP OUT OF THE AREA
ON THURSDAY WHERE THE GFS LINGERS...WILL RESPECT THE GFS ENOUGH
FOR LOW POPS THURSDAY.
FRIDAY THROUGH SATURDAY NIGHT HAS ANOTHER RIDGE AND FAIR WEATHER
FOR THE REGION.
SATURDAY NIGHT THROUGH MONDAY ANOTHER UPPER LEVEL SYSTEM MOVES
THROUGH THE REGION. THE MODELS HAVE THE SIMILAR IDEA THAT A SYSTEM
WILL MOVE THROUGH THE PLAINS OR PRAIRIES...HOWEVER LOCATION OF THE
SYSTEM IS DIFFERENT IN EACH MODEL TO PROVIDE INCREASE CONFIDENCE
AT THIS TIME TO INCREASE PRECIPITATION CHANCES. PROTON
&&
.AVIATION...
FLIGHT CATEGORY: VFR.
A CLUSTER OF THUNDERSTORMS NEAR BOZEMAN DURING THE MID AFTERNOON
WILL CONTINUE MOVING NORTHEAST...POSSIBLY REACHING THE GLASGOW
AREA LATER THIS EVENING BEFORE THEY FALL APART. SHOWERS/THUNDERSTORMS
ARE NOT EXPECTED EAST OF A GLASGOW TO JORDAN LINE. CLEARING SKIES
WILL OCCUR IN THE WAKE OF TONIGHT/S WEATHER BUT ANOTHER ROUND OF
SHOWERS/ISOLATED STORMS WILL MOVE IN LATE TUESDAY.
SOUTHEAST WINDS WILL DIMINISH BY EARLY EVENING WITH LIGHT AND
VARIABLE WINDS LATE TONIGHT AND TUESDAY. TFJ
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR FORT PECK
LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...CENTRAL AND SOUTHERN
VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 PM EDT MON SEP 16 2013
.SYNOPSIS...
A COLD FRONT TO OUR NORTH WILL PUSH SOUTHWARD THROUGH NORTH CAROLINA
THIS EVENING INTO TONIGHT. CANADIAN HIGH PRESSURE WILL BUILD INTO
THE REGION FROM THE NORTH TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /TONIGHT AND TUESDAY/...
AS OF 300 PM MONDAY...
THROUGH TONIGHT: THE COLD FRONT CURRENTLY SITS ACROSS WV AND CENTRAL
VA... POISED TO CONTINUE DROPPING SOUTHWARD INTO NC BY EARLY THIS
EVENING THEN TO THE SC STATE LINE SOON AFTER MIDNIGHT... PROPELLED
BY THE DIGGING TROUGH OVER THE FAR NORTHEAST STATES. THE DEEPEST
CONVECTION SO FAR THIS AFTERNOON HAS BEEN CONFINED TO AREAS SOUTH
AND EAST OF THE FORECAST AREA WITHIN THE BETTER LOW LEVEL THETA-E
ADVECTION ZONE AND WHERE INSTABILITY HAS BEEN GREATEST (1000 J/KG OF
MLCAPE... MORE THAN THE EARLY MORNING MODELS SUGGESTED). THIS
MORNING`S HIGH DEW POINTS HAVE MIXED OUT WITH HEATING... WELL DOWN
INTO THE 50S TO LOWER 60S OVER ALL BUT THE FAR SE CWA... SO LATEST
HRRR/RAP MODEL TRENDS OF HOLDING THE MORE SIGNIFICANT INSTABILITY
OVER THE FAR SE CWA FOR THE NEXT SEVERAL HOURS APPEARS REASONABLE.
WITH MOISTENING THROUGH THE COLUMN AND INCREASED PW VALUES JUST
AHEAD OF THE FRONT HOWEVER... STILL EXPECT ISOLATED (AND POSSIBLY
SCATTERED) SHOWERS TO PUSH SOUTHWARD INTO NORTH CENTRAL NC THROUGH
THE REST OF THE AFTERNOON... BEFORE PUSHING INTO CENTRAL AND
SOUTHERN SECTIONS OF THE FORECAST AREA BY LATE THIS EVENING. THE
GOOD INVERTED-V SIGNATURE SEEN ON RAP SOUNDINGS SUGGESTS THAT ANY OF
THESE SHOWERS AND STORMS MAY PRODUCE BRIEF STRONG WIND GUSTS.
WIDESPREAD CLOUDS AND A FEW SHOWERS ARE LIKELY TO LINGER INTO THE
OVERNIGHT HOURS OVER THE SW CWA WITH LOW LEVEL FLOW TAKING ON AN
UPSLOPE COMPONENT AND CONTINUED DECENT LOW LEVEL MOISTURE TRANSPORT.
FOLLOWING TRENDS OF THE HRRR AND LOCAL WRF... AND LOOKING AT
UPSTREAM TEMP TRENDS... EXPECT LOWS TO RANGE FROM 57 NORTH TO 64
SOUTH. WINDS BEHIND THE FRONT ARE LIKELY TO STRENGTHEN TO AROUND 10
KTS WITH GUSTS AS MUCH AS 15-20 KTS... ALTHOUGH CONFIDENCE IS LOW
REGARDING HOW MUCH WE`LL STAY MIXED TONIGHT.
FOR TUESDAY: EXPECT IMPROVING CONDITIONS FROM NNE TO SSW AS COOL
HIGH PRESSURE BUILDS IN. THE FRONT IS EXPECTED TO HANG UP ACROSS SC
AND BACK UP INTO FAR SW NC... AND CLOUDS ACROSS OUR FAR SOUTHERN AND
SW AREAS SHOULD BE SLOWER TO CLEAR OUT WITH FORECAST SOUNDINGS
INDICATING LINGERING MOISTURE AT AROUND 850-800 MB... BENEATH THE
WARM SUBSIDING MID LEVELS. OTHERWISE... BESIDES THE CLOUDS... EXPECT
QUIET AND DRY WEATHER WITH NOTABLY COOLER TEMPS... AS THICKNESSES
DROP OVERNIGHT TO AROUND 1370 M... SUPPORTING HIGHS 73-79. -GIH
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 245 PM MONDAY...
A HIGH PRESSURE RIDGE AXIS AT THE SURFACE AND ALOFT WILL EXTEND
ACROSS CENTRAL NC TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. THE DRY
STABLE AIR ASSOCIATED WITH THIS WEATHER FEATURE WILL RESULT IN CLEAR
TO FAIR SKIES AND TEMPS 3-5 DEGREES BELOW NORMAL ON WEDNESDAY. EARLY
WEDNESDAY MORNING LOW TEMPS WILL TEND TO BE A LITTLE CHILLY. MODEL
LOW LEVEL THICKNESSES WEDNESDAY MORNING HOVERING IN THE UPPER 1350S
TO THE MID 1360S. SUNDAY MORNING THICKNESSES VERIFIED IN THE UPPER
1360S. IF MODEL THICKNESSES VERIFY WEDNESDAY MORNING...MIN TEMPS IN
THE 45-50 DEGREE RANGE ONCE AGAIN HIGHLY PROBABLE IN THE OUTLYING
AREAS WITH LOW-MID 50S COMMON IN THE URBAN LOCATIONS. CAVEAT TO MIN
TEMPS WEDNESDAY MORNING: IF DECK OF STRATOCU DEVELOPS BELOW
SUBSIDENCE INVERSION (GFS EMPHASIZES THIS MORE THAN NAM)...THIS
WOULD SUGGEST MIN TEMPS 3-4 DEGREES WARMER THAN
FORECAST...ESPECIALLY ACROSS THE EAST). A MODIFYING AIR MASS BY
WEDNESDAY NIGHT SUGGEST MIN TEMPS 3-5 DEGREES WARMER COMPARED TO
TUESDAY NIGHT. MIN TEMPS GENERALLY IN THE MID-UPPER 50S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 250 PM MONDAY...
THURSDAY THROUGH FRIDAY NIGHT...
AIR MASS WILL UNDERGO MODIFICATION THIS PERIOD AS SURFACE HIGH
PRESSURE RIDGE SLOWLY WEAKENS AND DRIFTS EWD. THIS WILL ESTABLISH A
RETURN FLOW REGIME BY FRIDAY AND CONTINUING INTO FRIDAY NIGHT. WHILE
DRY WEATHER SHOULD RULE THROUGH FRIDAY...A STRAY SHOWER POSSIBLE
OVER THE NW PIEDMONT LATE FRIDAY. THICKNESSES RECOVER THURSDAY INTO
FRIDAY...SUPPORTIVE OF TEMPS RETURNING TO NEAR NORMAL VALUES
(UPPER 70S NW TO LOWER 80S SE).
SATURDAY THROUGH MONDAY...
MEDIUM RANGE MODEL GUIDANCE CONTINUES TO SUGGEST THE NEXT S/W IN THE
NORTHERN STREAM WILL AFFECT CENTRAL NC SATURDAY INTO SUNDAY. 12Z GFS
IS A LITTLE MORE VIGOROUS WITH THE S/W COMPARED TO ITS PREVIOUS RUNS
AS WELL AS THE 00Z ECMWF. GFS DEPICTS DEEPER MOISTURE AND MORE
ORGANIZED LIFT THROUGH THE ATMOSPHERE COMPARED TO THE 00Z ECMWF.
UNLIKE THE PREVIOUS TWO SYSTEMS IN WHICH WLY FLOW AHEAD OF THE FRONT
DETERRED MOISTURE TRANSPORT AND RESULTED IN JUST A FEW
SHOWERS...LATEST GUIDANCE SUGGEST A 12 HOUR WINDOW OF OPPORTUNITY TO
ADVECT MOISTURE OFF THE GULF INTO OUR REGION PRIOR TO FRONTAL
PASSAGE. THUS HAVE INCHED POPS UP A BIT FROM THE PREVIOUS FORECAST
FOR THE PERIOD LATE SATURDAY INTO SATURDAY NIGHT. IF MODEL TRENDS
CONTINUED...HIGH CHANCE OR LIKELY POPS MAY BECOME WARRANTED.
FRONTAL PASSAGE OCCURS SUNDAY INTO SUNDAY NIGHT WITH BETTER RAIN
CHANCES CONFINED TO THE EAST AND SOUTH SUNDAY AFTERNOON COMPARED
TO THE NW. HIGH PRESSURE BUILDS INTO THE REGION MONDAY WITH
ASSOCIATED DRIER AND MORE STABLE AIR MASS.
TEMPS THROUGH THE PERIOD WILL AVERAGE CLOSE TO NORMAL...MAYBE A
LITTLE ABOVE NORMAL SATURDAY ACROSS THE SE HALF AHEAD OF THE
FRONT...AND A COUPLE OF DEGREES BELOW NORMAL AREAWIDE MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1235 PM MONDAY...
THIS MORNING`S IFR/LIFR CLOUDS HAVE LIFTED TO VFR OR UNLIMITED WITH
HEATING. WINDS ARE LIGHT/VARIABLE MAINLY FROM THE WEST OR NORTH WITH
VFR CIGS AHEAD OF A COLD FRONT APPROACHING NC FROM THE NORTH. VFR
CONDITIONS WILL DOMINATE THIS EVENING... WITH CLOUDS FILLING BACK IN
BUT CIGS EXPECTED TO HOLD ABOVE 4 KFT AGL... HOWEVER WE DO EXPECT
ISOLATED TO SCATTERED SHOWERS AND A STORM OR TWO AHEAD OF THE FRONT
THIS AFTERNOON INTO EARLY EVENING... LIKELY TO AFFECT INT/GSO MAINLY
18Z-23Z... RDU/RWI MAINLY 20Z-01Z... AND FAY MAINLY 21Z-03Z...
ALTHOUGH GREATER ATMOSPHERIC INSTABILITY NEAR FAY MAY RESULT IN A
MORE PROLONGED RISK OF STORMS HERE. DUE TO A DRY LOW LEVEL
PROFILE... BRIEF CONVECTIVE WIND GUSTS OVER 30 MPH ARE POSSIBLE IN
AND NEAR SHOWERS OR STORMS... AND IT MUST BE STRESSED THAT THESE
STRONG GUSTS COULD OCCUR IN THE ABSENCE OF ANY LIGHTNING/THUNDER...
AS EVEN ORDINARY SHOWERS COULD PUT DOWN SOME SHORT-DURATION GUSTY
WINDS. DUE TO THE SHORT DURATION OF GUST THREAT NEAR
SHOWERS/STORMS... WILL NOT INCLUDE AS A DOMINANT CONDITION INT HE
TAFS. CIGS ARE LIKELY TO REMAIN PREDOMINANTLY VFR IN AND NEAR
SHOWERS/STORMS WITH BRIEF MVFR VSBYS POSSIBLE. BY MID TO LATE
EVENING... THE FRONT WILL BE MOVING SOUTHWARD THROUGH NC... AND A
SHIFT OF WINDS TO BE FROM THE NORTHEAST AND INCREASE IN SPEED
(SUSTAINED UP TO 8-12 KTS AND GUSTS OF 13-20 KTS) IS LIKELY NEAR AND
IN THE HOURS BEHIND THE FRONT AS COOLER AIR RUSHES IN FROM THE
NORTH. VFR CIGS ARE LIKELY TO HOLD THROUGH EARLY TUE AFTERNOON WITH
CLOUDS SCATTERING OUT ACROSS NRN NC. ALSO... AFTER 13Z... WINDS WILL
BECOME MORE UNIFORMLY FROM THE ENE THROUGH THE MIXED LAYER AT SPEEDS
OF 8-10 KTS.
LOOKING BEYOND 18Z TUESDAY... VFR WITH THE FOLLOWING EXCEPTIONS:
SHALLOW IFR FOG IS POSSIBLE WITHIN STABLE SURFACE RIDGE EARLY
WEDNESDAY MORNING. A WARM FRONT EXPECTED TO SHIFT TOWARD THE NE OVER
NC MAY BRING A QUICK MVFR SHOWER THURSDAY AFTERNOON. ANOTHER COLD
FRONT COULD BRING BETTER COVERAGE OF MVFR/IFR SHOWERS/STORMS ON
SATURDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TH
NEAR TERM...HARTFIELD
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1235 PM EDT MON SEP 16 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTH LATE THIS AFTERNOON...
THEN PUSH SOUTH THROUGH THE AREA THIS EVENING INTO TONIGHT. CANADIAN
HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY AND PERSIST
THROUGH WEDNESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 920 AM MONDAY...
UPDATE THROUGH REST OF TODAY: THE ISOLATED BAND OF SHALLOW BUT VERY
HEAVY RAIN SHOWERS WHICH PASSED THROUGH THE TRIANGLE EARLY THIS
MORNING IS MOVING QUICKLY EASTWARD THROUGH THE CENTRAL COASTAL
PLAIN. THESE SHOWERS APPEAR TO HAVE BEEN DRIVEN BY INTENSE LOW LEVEL
MOIST UPGLIDE (NOTED ON RAP OUTPUT AT 300K) ALONG A PROMINENT TONGUE
OF HIGH SURFACE THETA-E NOSING UP THROUGH THE ERN SANDHILLS TOWARD
RALEIGH/WILSON/GOLDSBORO... POSSIBLY AUGMENTED BY A FEW DOZEN J/KG
OF CAPE OBSERVED ON RAP PROXIMITY SOUNDINGS. THIS WAS AN INTERESTING
OCCURRENCE AS IT WAS DRIVEN BY SUBTLE AND SMALL YET STRONG FORCING
FEATURES... CONFINED TO THE LOWEST 2.5 KM WITH VERY DRY/STABLE AIR
ABOVE... THAT WERE POORLY HANDLED BY LAST NIGHT`S COMPUTER MODEL
GUIDANCE. A FEW LIGHTER AND MORE PATCHY SHOWERS TRAILING THE HEAVIER
RAINBAND ARE EXPECTED TO ALSO SHIFT EAST IN THE NEXT FEW HOURS
ACCORDING TO THE LATEST HRRR. WILL CARRY A MENTION OF ISOLATED
SHOWERS FOR THE REST OF THE MORNING EAST OF RDU... THEN EXPECT A
BRIEF LULL IN ANY PRECIP CHANCES THROUGH EARLY AFTERNOON AS DAYTIME
HEATING HELPS TO MIX OUT THE VERY MOIST LOW LEVELS OVER MUCH OF
CENTRAL NC... WHILE DRIER DEW POINTS AND LOWER 925-850 MB THETA-E
FILTER IN FROM THE WEST AHEAD OF THE COLD FRONT APPROACHING FROM THE
NORTH. WE SHOULD SEE ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS
PUSHING IN FROM THE NORTH VERY LATE THIS AFTERNOON INTO EARLY
EVENING JUST AHEAD OF THE FRONT... FORCED BY INCREASING MASS
CONVERGENCE IN THE LOWER LEVELS AND INCREASING UPPER DIVERGENCE IN
THE RIGHT ENTRANCE REGION OF THE STRENGTHENING JET FOCUSED IN THE
UPPER ST LAWRENCE VALLEY. MID LEVEL MOISTURE IS EXPECTED TO RISE
QUITE A BIT LATER THIS AFTERNOON WITH PW REBOUNDING ABOVE 1.4
INCHES... SO THESE LATE-DAY SHOWERS SHOULD BE DEEPER... ALTHOUGH WE
SHOULD STILL ONLY SEE 100 J/KG OR LESS OF MLCAPE... PERHAPS NEAR 200
J/KG IN THE EXTREME SE WHERE A MENTION OF THUNDER WILL BE RETAINED.
TEMPS ARE TRICKY AND WILL DEPEND ON THE BEHAVIOR OF THE STRATOCU
EAST OF THE TRIAD. THESE CLOUDS LOOK TO BE MOVING STEADILY EASTWARD
HOWEVER WITH SOME GOOD BREAKS IN THE CLOUDS... SO WITH AN
ABOVE-NORMAL 12Z GSO THICKNESS OF 1394 M... STILL EXPECT HIGHS OF
83-87 WITH MOSTLY CLOUDY SKIES BECOMING PARTLY CLOUDY. -GIH
TONIGHT:
WILL KEEP A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ALONG AND
EAST OF HWY 1 THIS EVE WHERE THE RELATIVE BEST LOW-LEVEL MOISTURE
AND DESTABILIZATION IS EXPECTED...WITH ANY POTENTIAL FOR THUNDER
CONFINED TO THE SANDHILLS/SE COASTAL PLAIN. EXPECT CHANCES ENDING
FROM NW-SE OR NNW-SSE BY MIDNIGHT AS A DRIER /MORE STABLE/ AIRMASS
ADVECTS INTO THE REGION IN THE WAKE OF THE FRONT. LOWS TONIGHT WILL
BE DRIVEN BY COLD ADVECTION AND WILL DEPEND ON THE PRECISE TIMING OF
THE COLD FRONTAL PASSAGE...MEANING FCST LOW TEMPS COULD EASILY BUST
BY SEVERAL DEGREES. BASED ON THE LATEST FROPA TIMING (21-03Z N-S)...
EXPECT LOWS RANGING FROM THE UPPER 50S NEAR THE VA BORDER TO THE
LOWER/MID 60S NEAR THE SC BORDER. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 300 AM MONDAY...
HIGH PRESSURE WILL BUILD INTO THE MID-ATLANTIC ON TUE...WITH A
PRONOUNCED SFC RIDGE AIS EXTENDING S/SW INTO CENTRAL NC. GIVEN A
DRY/STABLE AIRMASS IN PLACE IN THE WAKE OF THE COLD FRONT...EXPECT
CLEARING SKIES WITH HIGHS IN THE MID/UPPER 70S TO NEAR 80F...WARMEST
SOUTH AND COOLEST NORTH. LOWS TUE NIGHT RANGING FROM ~50F AT THE VA
BORDER TO THE MID/UPPER 50S SOUTH. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...
CHILLY CONTINENTAL POLAR HIGH PRESSURE CENTERED OVER SOUTHERN
ONTARIO THIS MORNING WILL MODIFY AS IT BUILDS TO THE NORTHERN MIDDLE
ATLANTIC STATES BY MID WEEK. FORECAST GUIDANCE SUGGESTS THE RIDGE
AXIS WILL THEN CONTINUE TO EXTEND SOUTHWESTWARD ALONG AND EVENTUALLY
JUST OFFSHORE THE EAST COAST...SUPPORTED BY LONGWAVE RIDGING ALOFT
DOWNSTREAM OF A SERIES OF STRONG UPPER LOWS FORECAST TO MIGRATE
EASTWARD ALONG THE US/CANADIAN BORDER IN PROGRESSIVE LATE SUMMER
FLOW. THE FIRST OF THESE UPPER LOWS WILL PROPEL A COLD FRONT INTO
THE EASTERN US THIS WEEKEND...WITH FAVORED TIMING IN CENTRAL NC
DURING THE SECOND HALF OF THE WEEKEND - WITH AVERAGE TO
SLIGHTLY ABOVE FORECAST CONFIDENCE DUE TO TYPICAL TROUGH ALOFT
TIMING...AMPLITUDE...AND TILT DIFFERENCES DEPICTED BY THE MEDIUM
RANGE NWP GUIDANCE AT THAT TIME RANGE.
RETURN FLOW AROUND THE SURFACE RIDGE WILL PROMOTE A VEERING OF THE
LOW LEVEL FLOW FROM NE-ENE DURING THE MIDDLE OF THE WEEK - WITH SCT
TO BKN STRATOCUMULUS FROM MOISTURE TRAPPED BENEATH A SUBSIDENCE
INVERSION WED-WED NIGHT - TO A WARMING S-SW COMPONENT BY FRI-SAT.
THE ASSOCIATED WARMING WILL SEND TEMPERATURES BACK INTO THE LOWER TO
MIDDLE 80S AHEAD OF THE AFOREMENTIONED APPROACHING COLD FRONT...
WARMEST FRI-SAT. LOWS WILL MODIFY AS WELL...FROM COOLEST READINGS IN
THE 50S THU MORNING...TO MIDDLE 60S SAT NIGHT.
PRECIPITATION CHANCES WILL BE TIED TO THE PASSAGE OF THE FRONT
THROUGH WEAK WARM SECTOR INSTABILITY. HAVE ACCORDINGLY REMOVED
PRECIPITATION CHANCES FROM FRI AND INSTEAD CONFINED A LOW CHANCE OF
SHOWERS AND STORMS TO THE FAVORED FRONTAL PASSAGE TIMING LATE
SAT-SUN.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1235 PM MONDAY...
THIS MORNING`S IFR/LIFR CLOUDS HAVE LIFTED TO VFR OR UNLIMITED WITH
HEATING. WINDS ARE LIGHT/VARIABLE MAINLY FROM THE WEST OR NORTH WITH
VFR CIGS AHEAD OF A COLD FRONT APPROACHING NC FROM THE NORTH. VFR
CONDITIONS WILL DOMINATE THIS EVENING... WITH CLOUDS FILLING BACK IN
BUT CIGS EXPECTED TO HOLD ABOVE 4 KFT AGL... HOWEVER WE DO EXPECT
ISOLATED TO SCATTERED SHOWERS AND A STORM OR TWO AHEAD OF THE FRONT
THIS AFTERNOON INTO EARLY EVENING... LIKELY TO AFFECT INT/GSO MAINLY
18Z-23Z... RDU/RWI MAINLY 20Z-01Z... AND FAY MAINLY 21Z-03Z...
ALTHOUGH GREATER ATMOSPHERIC INSTABILITY NEAR FAY MAY RESULT IN A
MORE PROLONGED RISK OF STORMS HERE. DUE TO A DRY LOW LEVEL
PROFILE... BRIEF CONVECTIVE WIND GUSTS OVER 30 MPH ARE POSSIBLE IN
AND NEAR SHOWERS OR STORMS... AND IT MUST BE STRESSED THAT THESE
STRONG GUSTS COULD OCCUR IN THE ABSENCE OF ANY LIGHTNING/THUNDER...
AS EVEN ORDINARY SHOWERS COULD PUT DOWN SOME SHORT-DURATION GUSTY
WINDS. DUE TO THE SHORT DURATION OF GUST THREAT NEAR
SHOWERS/STORMS... WILL NOT INCLUDE AS A DOMINANT CONDITION INT HE
TAFS. CIGS ARE LIKELY TO REMAIN PREDOMINANTLY VFR IN AND NEAR
SHOWERS/STORMS WITH BRIEF MVFR VSBYS POSSIBLE. BY MID TO LATE
EVENING... THE FRONT WILL BE MOVING SOUTHWARD THROUGH NC... AND A
SHIFT OF WINDS TO BE FROM THE NORTHEAST AND INCREASE IN SPEED
(SUSTAINED UP TO 8-12 KTS AND GUSTS OF 13-20 KTS) IS LIKELY NEAR AND
IN THE HOURS BEHIND THE FRONT AS COOLER AIR RUSHES IN FROM THE
NORTH. VFR CIGS ARE LIKELY TO HOLD THROUGH EARLY TUE AFTERNOON WITH
CLOUDS SCATTERING OUT ACROSS NRN NC. ALSO... AFTER 13Z... WINDS WILL
BECOME MORE UNIFORMLY FROM THE ENE THROUGH THE MIXED LAYER AT SPEEDS
OF 8-10 KTS.
LOOKING BEYOND 18Z TUESDAY... VFR WITH THE FOLLOWING EXCEPTIONS:
SHALLOW IFR FOG IS POSSIBLE WITHIN STABLE SURFACE RIDGE EARLY
WEDNESDAY MORNING. A WARM FRONT EXPECTED TO SHIFT TOWARD THE NE OVER
NC MAY BRING A QUICK MVFR SHOWER THURSDAY AFTERNOON. ANOTHER COLD
FRONT COULD BRING BETTER COVERAGE OF MVFR/IFR SHOWERS/STORMS ON
SATURDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TH
NEAR TERM...HARTFIELD/VINCENT
SHORT TERM...VINCENT
LONG TERM...MWS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
548 PM EDT MON SEP 16 2013
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN THROUGH THE MIDDLE
OF THE WEEK. AFTER A CHILLY START ON TUESDAY...A MILDER SOUTHWEST
FLOW WILL DEVELOP THROUGH THE SECOND HALF OF THE WEEK...WITH
TEMPERATURES CLIMBING SLIGHTLY ABOVE NORMAL. A COLD FRONT WILL
BRING SHOWERY CONDITIONS AS IT CROSSES THE REGION OVER THE
WEEKEND...FOLLOWED BY ANOTHER COOL CANADIAN AIR MASS FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
COLD FRONT WELL SOUTH OF THE STATE THIS AFTERNOON...BUT COLD AIR
STRATO CU REMAINS ACRS CENTRAL PA...WITH INCREASING BINOVC
DEVELOPING OVER ALL OF CENTRAL PA NOW. STILL A CHANCE FOR AN
INSTABILITY SHOWER MAINLY ALONG THE NORTHERN BORDER...BUT CHANCES
WILL DIMINISH QUICKLY AS WE APPROACH SUNSET. HIGHS WILL FINISH ON
THE COOL SIDE RANGING FROM AROUND 60 OVER THE NW TO AROUND 70F IN
THE LOWER SUSQ VALLEY.
SKIES WILL MORE RAPIDLY CLEAR THIS EVENING AS SPRAWLING HIGH PRES
BUILDS SEWD ACRS THE LWR LKS. THIS WILL BRING A CHILLY NIGHT TO
THE REGION...WITH TEMPS SLIPPING BACK INTO THE 30S AND 40S. A
FROST ADVISORY HAS BEEN POSTED FOR THE NORTHERN TIER.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE WILL MAINTAIN ITS GRIP ON THE REGION THRU WEDNESDAY
BEFORE SLOWLY RETREATING OFF THE SRN NEW ENGLAND COAST THURSDAY
NIGHT. A MILDER RETURN S-SW FLOW WILL BRING ABOUT A SLOW
MODERATION IN DAILY MAX/MIN TEMPS WITH A GRADUAL INCREASE IN
HUMIDITY. TOMORROW NIGHT WILL AGAIN BE CHILLY ACROSS THE NRN TIER
WITH PATCHY FROST POSSIBLE...WITH IS HIGHLIGHTED IN THE HWO.
SCT CONVECTION IS POSSIBLE OVER THE WRN AND CNTRL ZONES THU
AFTN INTO THU NGT...AS WARM FRONT BEGINS TO LIFT NEWD FROM THE
UPPER OH VLY INTO WRN PA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
TEMPERATURES SHOULD PEAK ON FRIDAY AS THE AREA BREAKS INTO THE WARM
SECTOR AHEAD OF A WELL-DEFINED COLD FRONT PUSHING EWD THRU THE GRT
LKS/OH VLY. THERE ARE SOME MINOR TIMING DIFFS CONCERNING THE COLD
FROPA ON SATURDAY...WITH THE GFS/GEFS A LITTLE MORE PROGRESSIVE
THAN THE ECMWF. DECENT SURGE OF MSTR WITH ABV NORMAL PWATS AHEAD
OF THE FRONT SHOULD PROMOTE SCT CONVECTIVE RAINS ON DAY 5 AND 6.
SOME SHOWER ACTIVITY MAY LINGER INTO SUNDAY WITH THE UPPER TROUGH
PASSAGE...BEFORE HIGH PRESSURE BRINGS A COOLING TREND WITH DRY WX
FROM LATE IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
EARLY EVENING VISIBLE LOOP SHOWS SCT CU ACROSS MOST OF CENTRAL PA
WITH WIDESPREAD VFR CONDS. LOW LVL MOISTURE TRAPPED BENEATH
INVERSION IS RESULTING IN LOW CIGS JUST NORTH OF THE PA BORDER AND
CONCERN IS THAT SOME OF THESE LOW CIGS WILL CREEP INTO BFD EARLY THIS
EVENING BEFORE MUCH DRIER AIR ARRIVES LATE THIS EVENING. THE
LEADING EDGE OF THIS DRIER AIR MASS IS EVIDENT BY RAPID CLEARING
TAKING PLACE ALONG THE SOUTH SHORE OF LK ONTARIO AT 21Z. WOULD NOT
RULE OUT A PERIOD OF IFR CIGS AT BFD BTWN 23Z-03Z. RAP SOUNDINGS
SHOWS THE MUCH DRIER AIR ARRIVING ARND 03Z...AFTER WHICH MAINLY
CLEAR SKIES EXPECTED ACROSS ALL OF CENTRAL PA.
DIMINISHING WINDS...COOL TEMPS AND RELATIVELY WARM RIVER/STREAM
WATER...COULD RESULT IN PATCHY FOG IN THE DEEP VALLEYS OF THE
ALLEGHENIES EARLY TUE AM. CLIMATOLOGY WOULD INDICATE BFD AND IPT
COULD SEE A BRIEF VIS/CIG REDUCTION ARND DAWN.
LARGE HIGH PRESSURE SYSTEM AND ASSOCIATED DRY AIR MASS WILL BE OVR
THE REGION LATER TUESDAY...ENSURING A NEAR CERTAINTY OF MSUNNY
SKIES AND LIGHT WINDS.
OUTLOOK...
WED-THU...NO SIG WX. WIDESPREAD VFR.
FRI...ISOLD PM TSRA IMPACTS POSSIBLE W MTNS.
SAT...RAIN LIKELY WITH COLD FRONTAL PASSAGE. MVFR POSS MAINLY NW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 2 AM TO 8 AM EDT TUESDAY FOR PAZ004>006-
037-041-042.
&&
$$
SYNOPSIS...RXR
NEAR TERM...RXR
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/RXR
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
345 PM CDT MON SEP 16 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 344 PM CDT MON SEP 16 2013
STRATOCUMULUS FIELD REMAINS FAIRLY WIDESPREAD ACROSS THE WESTERN AND
SOUTHERN PORTIONS OF THE CWA AT MID AFTERNOON...WITH INVERSION EVIDENT
IN MORNING KOAX RAOB DUCTING THE CLOUD FIELD ON INCREASING SOUTHERLY
COMPONENT TO LOW LEVEL WINDS. DRIER AIR TO THE NORTH HAS ALLOWED
EARLIER CLOUDS TO REFORM HIGHER THEN MIX OUT...MAINLY CLEAR ALONG
THE NORTHERN TIER AND THROUGH THE MID TO LOWER JAMES VALLEY. WITH
CONTINUED EAST/SOUTHEAST TRAJECTORY AND CELLULAR NATURE...SHOULD SEE
A DECREASE IN CLOUD COVERAGE INTO EARLY EVENING.
AREA OF SHOWERS CURRENTLY ONGOING ACROSS NORTHERN KANSAS AND FAR
SOUTHERN NEBRASKA...AND FORCING ASSOCIATED WITH THIS LOOKS TO MAKE A
BEELINE TOWARD OUR SOUTHEAST CWA STARTING AFTER 06Z. WITH TIMING OF
INCREASE IN THETA E ADVECTION AHEAD OF WAVE LIFTING EAST/NORTHEAST
FROM SOUTHWEST NEBRASKA/NORTHWEST KANSAS...WILL MENTION SCATTERED
SHOWERS...WITH MAIN PV FORCING SLIPPING JUST TO THE SOUTH. AGAIN
NOT A GREAT DEAL OF INSTABILITY...EVEN ELEVATED...AS LOW LEVEL JET
INCREASES TONIGHT. LIKELY THAT A BULK OF THE PRECIPITATION SHOULD
END IN THE EAST BY 18Z TO 20Z AS THE MID LEVEL WAVE PASSES...BUT
THERE IS A PERSISTENT LOWER TO MID LEVEL THETA-E ADVECTION. PRETTY
CAPPED TO SURFACE BASED ACTIVITY...BUT COULD SEE AN ISOLATED SHOWER
OR EVEN RUMBLE OF THUNDER BY MID TO LATE AFTERNOON ACROSS THE
SOUTHEAST THIRD OF THE AREA. DID NOT EXPLICITLY MENTION...BUT
MAY HAVE SOME ISSUES WITH DRIZZLE WELL BACK WESTWARD OF I29 DURING
THE MORNING TO MIDDAY HOURS. IN FACT...LOWER LEVELS CONTINUE TO
INDICATE INVERSION WHICH MAY YIELD TOUGHER THAN EXPECTED EROSION OF
LOWER CLOUDS...WHICH ARE NOTORIOUSLY HANDLED POORLY BY MODELS. DID
LOWER MAX TEMPS IN RESPONSE TO THE EXPECTED WIDESPREAD STRATUS...
LEAVING EXTREME WEST WITH A CHANCE TO REACH MID TO UPPER 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 344 PM CDT MON SEP 16 2013
TOUGH CALL ON POPS TUESDAY NIGHT WITH INSTABILITY AND HEIGHTS TRYING
TO BUILD ACROSS THE EASTERN HALF OF THE FORECAST AREA. MOST UNSTABLE
CAPE PEAKS OUT AROUND 1800 J/KG IN THE NAM...AND WITH MODERATE
WAA/THETAE ADVECTION CONTINUING ALOFT COULD SEE SOME THUNDERSTORMS
IN THE EAST. QUESTIONS REMAIN AS TO WHETHER CONVECTION WILL GET
GOING WITH LACK OF STRONG UPPER LEVEL SUPPORT ACROSS THE AREA...SO
HAVE LEFT POPS IN THE CHANCE RANGE THROUGH THE OVERNIGHT. WITH A
BREEZY SOUTH WINDS...TEMPERATURES SHOULD BE SLOW TO FALL THROUGH THE
OVERNIGHT.
BREEZY SOUTH WINDS CONTINUE ON WEDNESDAY AS STRONG SURFACE WARM
FRONT LIFTS THROUGH THE AREA. AS THE FRONT MOVES THROUGH THE
AREA...SOUNDINGS SUGGEST SKIES WILL CLEAR AND BOUNDARY LAYER WILL
BECOME QUITE DEEP THROUGH THE DAY. NAM MIXES TO NEAR 700 MB WHICH
RESULTS IN RECORD HIGHS IN THE 90S. HAVE NOT SIDED WITH AS MUCH
MIXING AND INSTEAD WENT WITH FORECAST HIGHS CLOSE TO 850 HPA MIX OUT
WHICH IS STILL 15-20 DEGREES ABOVE NORMAL.
SURFACE COLD FRONT IS EXPECTED TO MOVE THROUGH THE REGION WEDNESDAY
NIGHT INTO THURSDAY. UPPER WAVE LINGERS WELL BEHIND THE SURFACE
FRONT...AND WELL TO THE NORTH AND QUESTION BECOMES WHETHER
ATMOSPHERE WILL BE ABLE TO GET AROUND THE CAP TO PRODUCE
THUNDERSTORMS. HAVE PLACED FOCUS OF CHANCE POPS CLOSER TO THE MID
LEVEL WAVE ALONG AND NORTH OF I-90...BUT EVEN THEN...CONVECTION MAY
STILL BE FOCUSED FURTHER TO THE NORTH CLOSER TO THE MID-LEVEL WAVE.
SURFACE HIGH PRESSURE DOMINATES ACROSS THE REGION FRIDAY INTO
SATURDAY LEADING TO EARLY FALL CONDITIONS WITH NEAR NORMAL
TEMPERATURES. APPEARS AS THOUGH WARM FRONT WILL LIFT THROUGH THE
AREA SUNDAY MORNING ASSOCIATED WITH DEEPENING UPPER LEVEL TROUGH.
POPS HAVE REALLY BEEN THROTTLED BACK WITH PASSAGE OF THE WARM FRONT
ON SUNDAY...WITH RELATIVELY STRONG SOUTHERLY FLOW CONTINUING INTO
MONDAY AHEAD OF THE NEXT COLD FRONT TO MOVE THROUGH THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1254 PM CDT MON SEP 16 2013
WIDESPREAD CEILINGS ACROSS ALL BUT PARTS OF SW MN AT MIDDAY. MOST
OF THE NORTHEAST FLANK FEATURES SOMEWHAT MORE SHALLOW MOISTURE
PROFILE WITH MIXING DISSIPATING NORTHEAST FLANK OF CLOUDS...WHILE
FARTHER SOUTHWEST HAVE SEEN DEVELOPMENT OF BROKEN TO OVERCAST
CEILINGS WITH DIURNAL HEATING...SUPPORTED WELL ON MORNING 12Z KOAX
RAOB. LIKELY THAT EASTERLY TRAJECTORY WILL AID IN AT LEAST BKN-SCT
CEILINGS...AND MAINLY VFR HEIGHTS FOR THE AFTERNOON AND EARLY
EVENING. RAP IS ABOUT THE ONLY MODELS WHICH IS PROFICIENT IN
PREDICTING THE CLOUD COVERAGE POTENTIAL...AND SUGGESTS THAT
INCREASING SOUTHEASTERLY TRAJECTORY WILL PULL STRATUS ANEW INTO
THE AREA BY LATER EVENING...WITH DEVELOPMENT OF WIDESPREAD MVFR
CEILINGS. WILL ALSO BE POSSIBILITY FOR A FEW SHOWERS BETWEEN 08Z
AND 14Z IN KSUX AREA. WITH STRATUS HOLDING IN DUE TO SOUTHERLY LOW
LEVEL FLOW AND INVERSION...SOME CONCERN THAT MIGHT BE THREAT FOR
DRIZZLE/FOG REDUCING VISIBILITIES FARTHER TO THE NORTHWEST...
INCLUDING KFSD AREA DURING THE MORNING HOURS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1254 PM CDT MON SEP 16 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM CDT MON SEP 16 2013
LOW LEVEL MOISTURE PATTERN IS A BIT CHAOTIC EARLY THIS MORNING
WITH AREAS OF LOW CLOUDS...BUT NOT LOW STRATUS...DEVELOPING AND
MOVING ACROSS THE AREA. THIS IS HAPPENING EVEN AS THE MORE SOLID
DECK HAS BEEN DECREASING FAR SOUTH OVER THE MISSOURI RIVER AREA.
SHORT TERM MODELS ESPECIALLY THE HRRR SEEM TO HAVE A HANDLE ON
THIS. THAT MODEL SHOWS THIS PATTERN CONTINUING THEN THE CLOUDS
DECREASING FAIRLY QUICKLY AROUND NOON. WILL GO WITH THIS IDEA AS
THE AIR GETS HEATED AND MIXED OUT. THAT SHOULD MAKE SKIES MOSTLY
SUNNY BY THE AFTERNOON. A SPLIT BETWEEN GUIDANCE AND CONTINUITY
LOOKS GOOD ON HIGH TEMPERATURES TODAY. TONIGHT THEN STARTS THE
WARM ADVECTION PATTERN OVER A DEEP RANGE OF LEVELS AND THE
ACCOMPANYING INCREASE IN CLOUDS FROM THE SOUTH...ESPECIALLY OVER
THE EASTERN PART OF THE AREA. LOW TEMPERATURES TONIGHT WILL NOT BE
AS COOL AS CURRENT VALUES. THE START OF AN INCREASE IN INSTABILITY
DOES NOT SEEM ENOUGH TO SUPPORT ANY SHOWERS OR STORMS THROUGH
TONIGHT...OR 12Z TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 303 AM CDT MON SEP 16 2013
THE CLOUD INCREASE IN THE WARM ADVECTION PATTERN WILL CONTINUE TO
EVOLVE TUESDAY AND SKIES SHOULD BECOME CLOUDY OR MOSTLY
CLOUDY...ESPECIALLY IN THE EAST. MEANWHILE...INSTABILITY CONTINUES
TO SLOWLY INCREASE BUT MAY BE LIMITED BY THE COPIOUS MOISTURE
ADVECTING IN...AND SUPPORT FOR SHOWERS AND STORMS IS OTHERWISE
QUITE MARGINAL. NEVERTHELESS...WITH MOISTURE INCREASING AT MOST
LEVELS...IT WOULD NOT TAKE MUCH FOR A FEW SHOWERS TO DEVELOP IN
OUR IOWA...MINNESOTA...AND EXTREME SOUTHEAST SD ZONES EVEN IF
THUNDERSTORMS HOLD OFF. WILL MENTION CHANCE OF SHOWERS AND
ISOLATED THUNDER. THIS SHOULD CONTINUE INTO TUESDAY NIGHT BUT
START TO MOVE SLOWLY EAST AND OUT OF THE AREA BY THE START OF
WEDNESDAY AS STRONG WARMING BEGINS TO OUTPACE THE MOISTURE...AND
RELATIVE HUMIDITIES AND CLOUD COVER DROPS OFF. TEMPERATURES WILL
BE WARMER TUESDAY BUT HELD DOWN SOME BY THE CLOUD COVER ESPECIALLY
EAST...THEN TUESDAY NIGHT SHOULD BE QUITE A BIT WARMER.
WEDNESDAY LOOK STILL SET TO BE A MUCH WARMER DAY WITH PLENTY OF
SUNSHINE. THE THREAT OF SHOWERS AND STORMS SHOULD HOLD OFF UNTIL
WEDNESDAY NIGHT WHEN THE COLD FRONT ENTERS THE AREA. HIGHS SHOULD
BE IN THE 80S WITH TEMPERATURES LIKELY REACHING A BIT ABOVE
GUIDANCE VALUES...AND WEDNESDAY NIGHT SHOULD BE WARM AGAIN AS THE
FRONT GETS INTO THE AREA.
FAIRLY POTENT FRONT TRACKS THROUGH THE EASTERN HALF OF THE
FORECAST AREA THURSDAY MORNING. ANY ONGOING SCATTERED SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF THE FRONT WILL TRACK EASTWARD
AND SHOULD DIMINISH BY LATE AFTERNOON. NORTHWEST WINDS WILL BE
BREEZY BEHIND THE FRONT AND PROVIDE A DECENT SHOT OF COLD AIR
ADVECTION THURSDAY NIGHT AND FRIDAY. LOWS WILL DIP INTO THE LOWER
50S ON THURSDAY AND AS COLD AS THE MID 40S FRIDAY NIGHT. WITH A
GENERAL UPPER LEVEL NORTHWEST FLOW PATTERN IN PLACE THROUGH THE
END OF THE WEEK...THE WEATHER WILL REMAIN DRY WITH HIGHS NEAR OR
JUST BELOW SEASONAL NORMALS. RIDGING OVER THE INTERMOUNTAIN WEST
SHIFTS EASTWARD INTO THE HIGH PLAINS FRIDAY NIGHT WITH THE AXIS
MOVING OVERHEAD SATURDAY NIGHT. WITH SOUTHERLY FLOW INCREASING ON
SUNDAY...TEMPERATURES WILL WARM BACK INTO THE MID 70S TO NEAR
80...BUT MAY ALSO BRING THE NEXT POTENTIAL FOR SHOWERS AND
THUNDERSTORMS. MODELS A BIT UNCERTAIN ON TIMING...BUT WILL LEAVE
LOW END CHANCES SUNDAY AND SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1254 PM CDT MON SEP 16 2013
WIDESPREAD CEILINGS ACROSS ALL BUT PARTS OF SW MN AT MIDDAY. MOST
OF THE NORTHEAST FLANK FEATURES SOMEWHAT MORE SHALLOW MOISTURE
PROFILE WITH MIXING DISSIPATING NORTHEAST FLANK OF CLOUDS...WHILE
FARTHER SOUTHWEST HAVE SEEN DEVELOPMENT OF BROKEN TO OVERCAST
CEILINGS WITH DIURNAL HEATING...SUPPORTED WELL ON MORNING 12Z KOAX
RAOB. LIKELY THAT EASTERLY TRAJECTORY WILL AID IN AT LEAST BKN-SCT
CEILINGS...AND MAINLY VFR HEIGHTS FOR THE AFTERNOON AND EARLY
EVENING. RAP IS ABOUT THE ONLY MODELS WHICH IS PROFICIENT IN
PREDICTING THE CLOUD COVERAGE POTENTIAL...AND SUGGESTS THAT
INCREASING SOUTHEASTERLY TRAJECTORY WILL PULL STRATUS ANEW INTO
THE AREA BY LATER EVENING...WITH DEVELOPMENT OF WIDESPREAD MVFR
CEILINGS. WILL ALSO BE POSSIBILITY FOR A FEW SHOWERS BETWEEN 08Z
AND 14Z IN KSUX AREA. WITH STRATUS HOLDING IN DUE TO SOUTHERLY LOW
LEVEL FLOW AND INVERSION...SOME CONCERN THAT MIGHT BE THREAT FOR
DRIZZLE/FOG REDUCING VISIBILITIES FARTHER TO THE NORTHWEST...
INCLUDING KFSD AREA DURING THE MORNING HOURS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1154 AM CDT MON SEP 16 2013
.AVIATION...
AN OUTFLOW BOUNDARY THAT EXTENDED FROM JUST NORTH OF KGLE
/GAINESVILLE/ AND KRPH /GRAHAM/ TO 30 MILES WEST OF KABI
/ABILENE/ AT 1650Z WILL CONTINUE TO MOVE SOUTHEAST AT NEAR 10
KNOTS THROUGH LATE AFTERNOON. ISOLATED SHOWERS HAVE DEVELOPED
ALONG THIS BOUNDARY AND SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED NEAR THIS BOUNDARY THIS AFTERNOON. ISOLATED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE ACROSS THE REST OF NORTH AND CENTRAL
TEXAS. FOR THE METROPLEX TAFS...HAVE PLACED VCTS IN THE TAFS FOR
THE 20Z-01Z PERIOD WITH A WIND SHIFT TO THE NORTH AT 20Z WITH THE
OUTFLOW BOUNDARY. WINDS SHOULD COME BACK AROUND TO THE EAST BY
01Z.
IN WACO...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE
FORECAST PERIOD. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE
LATE AFTERNOON THROUGH SUNSET...BUT THE CHANCES AT THE AIRPORT IS
TOO LOW TO INCLUDE IN THE TAF AT THIS TIME.
58
&&
.UPDATE...
LOCAL 15Z SURFACE ANALYSIS SHOWS A COLD FRONT IN NORTHERN OKLAHOMA
WITH CONVECTION ONGOING IN CLOSE PROXIMITY TO THE FRONT. AN OUTFLOW
BOUNDARY HAS SURGED SOUTH OVERNIGHT AND THE BOUNDARY IS JUST
ENTERING OUR NORTHWESTERN ZONES. THE MOVEMENT HAS SLOWED DOWN AS
HEATING HAS COMMENCED...BUT DO EXPECT A CONTINUED MOVEMENT THIS
MORNING. THIS BOUNDARY WILL LIKELY SERVE AS A MECHANISM FOR
SHOWERS AND THUNDERSTORM DEVELOPMENT THIS AFTERNOON ACROSS THE
NORTHERN HALF OF THE FORECAST AREA. CURRENT POP CONFIGURATION
LOOKS GOOD AND WILL MAKE NO CHANGES AT THIS TIME. NOT EXPECTING
SEVERE WEATHER AS CAPE VALUES REMAIN LESS THAN 1500 J/KG AND
SURFACE DEWPOINTS IN THE UPPER 60S SHOULD PREVENT DOWNBURST WINDS.
HOWEVER...A STRONG STORM IS POSSIBLE WITH GUSTY WINDS UP TO 50
MPH.
HAMPSHIRE
&&
.PREV DISCUSSION... /ISSUED 408 AM CDT MON SEP 16 2013/
EARLY MORNING WATER VAPOR SATELLITE IMAGERY SHOWED AN EXTENSIVE
PLUME OF TROPICAL MOISTURE OVER CENTRAL MEXICO DUE TO TROPICAL
DEPRESSION MANUEL MOVING ONSHORE THE WEST CENTRAL MEXICAN COAST. A
SECONDARY TROPICAL PLUME OF MOISTURE ASSOCIATED WITH HURRICANE
INGRID REMAINED JUST OFF SHORE OF THE NORTHEAST MEXICAN COAST.
ACROSS THE CONUS...A STRONG UPPER LEVEL TROUGH CONTINUED TO MOVE
SOUTHEAST OVER THE GREAT LAKES REGION TOWARDS THE EAST COAST. THE
SUBTROPICAL RIDGING THAT HAD BEEN DOMINATING THE PLAINS HAD BEEN
FLATTENED AND TILTED OVER THE SOUTHEASTERN UNITED STATES IN
RESPONSE TO THE PASSAGE OF THE STRONG NORTHERN STREAM TROUGH. THIS
LEFT GENERALLY WEAK WESTERLY FLOW OVER THE CENTRAL AND SOUTH
PLAINS THIS MORNING. A WEAK SHORTWAVE TROUGH WAS OBSERVED OVER THE
TX AND OK PANHANDLES...MOVING SLOWLY EAST ALONG A NEARLY STALLED
OUT COLD FRONT.
REGIONAL RADARS SHOWED A LARGE CLUSTER OF SHOWERS AND THUNDERSTORMS
ASSOCIATED WITH THE FRONT AND SHORTWAVE TROUGH AT 0830Z OR 330 AM
EXTENDING FROM AMARILLO TO NORTH CENTRAL OK. KFDR RADAR WAS
TRACKING A CONSOLIDATED OUTFLOW BOUNDARY THAT WAS MOVING SOUTHEAST
AWAY FROM THESE SHOWERS AND STORMS TOWARDS NORTH TEXAS.
TODAY...THE RAP AND THE NAM BOTH BOTH INDICATE THAT THE
CONSOLIDATED OUTFLOW BOUNDARY MOVING TOWARDS NORTH TEXAS EARLY
THIS MORNING WILL CONTINUE SOUTHEAST INTO THE CWA JUST AFTER
SUNRISE. THIS BOUNDARY WILL LIKELY STALL OUT SOMEWHERE NORTHWEST
OF THE DFW METROPLEX...WITH THE LATEST GUIDANCE SUGGESTING THE
BOUNDARY WILL COME TO REST NEAR A GAINESVILLE TO WEATHERFORD TO
CISCO LINE BY LATE THIS MORNING. LOCATIONS NEAR AND NORTHWEST OF
THE BOUNDARY WILL LIKELY SEE SOME ISOLATED TO SCATTERED RAIN
SHOWERS AND THUNDERSTORMS DEVELOP BY THE EARLY AFTERNOON HOURS OF
THE DAY. THIS IS PRIMARILY DUE TO THE FACT THAT THERE IS AMPLE
LOW-LEVEL MOISTURE IN PLACE TO SUPPORT PRECIPITATION...WITH THE
FRONT ACTING AS A LIFTING MECHANISM IN AN ENVIRONMENT
CHARACTERIZED WITH LITTLE TO NO CAPPING INVERSION ALOFT. WENT
AHEAD WITH A 30 PERCENT CHANCE OF RAIN FOR THESE LOCATIONS AS A
RESULT...INCLUDING MUCH OF THE DFW AREA.
ELSEWHERE ACROSS NORTH AND CENTRAL TEXAS...THE THERMODYNAMIC
ENVIRONMENT WILL BE NEARLY EQUIVALENT TO LOCATIONS NEAR THE
OUTFLOW BOUNDARY...BUT THERE IS NO OBVIOUS LIFTING MECHANISM TO
SUPPORT THE INITIATION OF SHOWERS AND STORMS THIS AFTERNOON.
DURING THE PEAK HEATING HOURS OF THE DAY...THE BUOYANCY FORCE WILL
BE MAXIMIZED...AND ISOLATED SHOWERS AND STORMS MAY DEVELOP
ANYWHERE ACROSS THE CWA AS A RESULT. MOST PRECIPITATION SHOULD
REMAIN TIED TO DAYTIME HEATING TODAY...THEREFORE WENT AHEAD AND
KEPT A MENTION OF SHOWERS AND STORMS IN THE FORECAST ONLY THROUGH
03Z THIS EVENING.
HEATING IS A BIT OF A CONCERN TODAY BECAUSE WE HAVE EXTENSIVE
CLOUD COVER IN THE FORM OF CIRRUS CLOUDS OVER THE REGION. THESE
CLOUDS MAY BREAK UP A BIT THROUGHOUT THE DAY...BUT WE WILL NEVER
BE FULLY RID OF THEM. REGARDLESS...AT 3 AM REGIONAL TEMPERATURES
WERE HOLDING IN THE MID TO UPPER 70S FOR MOST LOCATIONS. SO
DESPITE PERSISTENT CIRRUS CLOUDS TO CONTEND WITH...A 15 TO 20
DEGREE TEMPERATURE INCREASE SHOULD BE EASY TO ATTAIN BRINGING MOST
LOCATIONS UP INTO THE MID 90S FOR HIGHS WHICH IS WARM ENOUGH TO
SUPPORT ISOLATED STORMS IN THE FORECAST.
CONCERNING THE REMNANTS OF INGRID AND MANUEL...WITH THE
SUBTROPICAL RIDGE FLATTENED OUT...ITS CENTER OF CIRCULATION IS
EXPECTED TO SET UP ANYWHERE FROM SOUTHEAST TX TO THE MISSISSIPPI
COAST THROUGH THIS PERIOD. THE EXACT POSITION OF THIS RIDGE WILL
PLAY A LARGE ROLE IN TROPOSPHERIC STEERING FLOW/TRAJECTORIES FOR
TROPICAL MOISTURE INTO NORTH TX THROUGHOUT THE WEEK HEADED INTO
THIS WEEKEND. IF THE SUBTROPICAL RIDGE SETS UP FURTHER EAST...DEEP
TROPOSPHERIC FLOW WOULD FAVOR TRANSPORTING THE COMBINED MOISTURE
PLUMES FROM MANUEL AND INGRID FROM NORTHERN MEXICO INTO NORTH TX
BY LATE THIS WEEK. IF THE RIDGE SETS UP FURTHER WEST...THE MID AND
UPPER LEVEL TROPICAL MOISTURE WILL BE SHUNTED WEST AWAY FROM
TEXAS. UNFORTUNATELY MODELS REMAIN INCONSISTENT WITH REGARDS TO
THIS SOLUTION...SO DID NOT MAKE ANY HUGE ADJUSTMENTS TO THE
PREVIOUS FORECAST AT THIS TIME.
IN GENERAL...CONTINUE TO CARRY LOW POPS/RAIN CHANCES FROM TUESDAY
THROUGH THURSDAY...BECOMING MORE CONFIDENT AND WIDESPREAD WITH
RAIN CHANCES FOR FRIDAY AND SATURDAY BEFORE RETURNING TO A DRY
FORECAST ON SUNDAY. FOR MORE DETAILS READ ON...
TUESDAY THROUGH THURSDAY...REGARDLESS OF WHAT HAPPENS WITH THE
TROPICAL MOISTURE PLUME FROM THE MEXICAN TROPICAL CYCLONES...THE
MOST IMPORTANT THING TO WATCH DURING THIS TIME FRAME IS THE
DIRECTION OF LOW LEVEL WINDS. LOOKING AT THE 850 MB LEVEL...WINDS
THAT REMAIN EASTERLY NEAR THE GULF COAST WILL PREVENT RICH LOW-
LEVEL MOISTURE FROM MAKING ITS WAY NORTH INTO NORTH TX WHILE
SOUTHEASTERLY WINDS WILL SEND THIS MOISTURE RIGHT UP THE I-35
CORRIDOR. THE ECMWF HAS BEEN THE MOST CONSISTENT IN FORECAST 850
MB WINDS THE PAST FEW DAYS...SO THIS FORECAST CLOSELY FOLLOWS THE
GUIDANCE OF THIS MODEL.
THE ECMWF MAINTAINS EASTERLY WINDS AT 850 MB THROUGH WEDNESDAY
MORNING. AS A RESULT...DROPPED POPS ON TUESDAY TO 10 PERCENT FOR
THE ENTIRE CWA WITH LESS CONFIDENCE IN MOISTURE AVAILABLE AND
INSTABILITY TUESDAY AFTERNOON. THE 850 MB FLOW VEERS THROUGHOUT
THE DAY ON WEDNESDAY SLOWLY SENDING RICH GULF MOISTURE NORTH INTO
THE CWA FROM THE SOUTHEAST WEDNESDAY AFTERNOON. WENT AHEAD WITH 20
PERCENT CHANCE OF STORMS FOR THE SOUTHEASTERN HALF OF THE FORECAST
AREA AS A RESULT. BY THURSDAY AFTERNOON...H850 FLOW IS SOUTH-
SOUTHEASTERLY WHICH WOULD START SENDING SOME DEEPER TROPICAL
MOISTURE INTO THE CWA. WENT AHEAD WITH WIDESPREAD 20 POPS FOR THE
ENTIRE AREA THURSDAY AND THURSDAY NIGHT ASSUMING THE ECMWF PANS
OUT AS EXPECTED. WHILE THE GFS HAS TIMING DIFFERENCES...ONCE THE
850 MB FLOW VEERS AROUND TO THE SOUTHEAST...THE GFS INDICATES
PWATS INCREASE TO 2 INCHES. THIS WOULD BE GETTING CLOSE TO 2
STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR WHICH
CERTAINLY SUPPORTS THE BROAD BRUSHED POPS.
FRIDAY AND SATURDAY...THE BIG QUESTION FOR THIS PERIOD IS...WILL
WE HAVE MID AND UPPER LEVEL TROPICAL MOISTURE IN PLACE COURTESY OF
MANUEL AND INGRID? IF WE DO...POPS WILL HAVE TO BE INCREASED MORE
THAN WHAT WE ARE CARRYING AT THIS TIME. EACH DAY A DIFFERENT MODEL
SHOWS THIS SOLUTION WHILE ANOTHER ONE BACKS OFF. THE CONSENSUS IS
ALWAYS AN ANSWER OF /NO/...BUT THE CONSENSUS NEVER CONSISTS OF THE
SAME MODELS. AS A RESULT CONFIDENCE IS LOW AS TO WHERE THE MEXICAN
TROPICAL MOISTURE PLUME WILL END UP AT THIS TIME.
EITHER WAY...THE CONSENSUS OF MODEL GUIDANCE CONTINUES TO SHOW A
SEASONABLY STRONG TROUGH MOVING EAST OVER THE PLAINS DURING THIS
TIME FRAME. THIS WOULD SEND A STRONGER COLD FRONT SOUTH INTO NORTH
TX WHICH SUPPORTS AT LEAST SCATTERED THUNDERSTORMS AS IT MOVES
SOUTH THROUGH THE REGION. WE ALREADY HAD 30 TO 40 POPS IN THE
FORECAST ALONG THIS FRONT...SO JUST MAINTAINED THIS FORECAST AT
THIS TIME. WILL CONTINUE TO CLOSELY MONITOR THE MEXICAN TROPICAL
MOISTURE PLUME IN THE COMING DAYS. IF THIS MOISTURE IS IN PLACE IT
DOES NOT REALLY CHANGE WHEN WE EXPECT SHOWERS AND STORMS...IT JUST
AFFECTS THE COVERAGE AND AMOUNTS OF RAINFALL. EITHER WAY...WE WILL
LIKELY BE DRY ON SUNDAY AS SUBSIDENCE SWEEPS THROUGH THE REGION.
CAVANAUGH
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 95 76 95 77 96 / 30 20 10 10 10
WACO, TX 96 74 96 75 96 / 10 10 10 10 20
PARIS, TX 96 70 95 72 95 / 20 20 10 10 10
DENTON, TX 94 73 94 74 95 / 30 20 10 10 10
MCKINNEY, TX 95 73 95 75 96 / 30 20 10 10 10
DALLAS, TX 97 78 96 79 97 / 30 20 10 10 10
TERRELL, TX 96 75 96 75 97 / 20 20 10 10 10
CORSICANA, TX 97 75 97 76 97 / 10 10 10 10 20
TEMPLE, TX 96 73 95 72 95 / 10 10 10 10 20
MINERAL WELLS, TX 93 71 93 72 94 / 30 20 10 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/85
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 PM CDT MON SEP 16 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 309 PM CDT MON SEP 16 2013
THE MAIN FOCUS INTO TOMORROW IS WITH THE POTENTIAL FOR FROST
TONIGHT IN NORTH CENTRAL WISCONSIN FOLLOWED BY THE CHANCES FOR
RAIN SHOWERS TOMORROW AFTERNOON.
CURRENTLY...MID TO UPPER LEVEL RIDGING IS DRIFTING EAST INTO THE
UPPER MISSISSIPPI RIVER VALLEY WHILE AN ELONGATED SHORT WAVE
TROUGH EXTENDS FROM SOUTHWEST CANADA DOWN THE FRONT RANGE OF THE
ROCKIES THROUGH THE CENTRAL PLAINS AND MID MISSISSIPPI RIVER
VALLEY. AT THE SURFACE...A BROAD RIDGE OF HIGH PRESSURE IS
CENTERED OVER THE UPPER GREAT LAKES WITH A TROUGH/COLD FRONT OUT
ALONG THE FRONT RANGE OF THE ROCKIES. DRY AIR ASSOCIATED WITH THIS
RIDGE HAS LED TO SKIES CLEARING OUT ACROSS THE REGION WITH SOME
STRATOCUMULUS HANGING ON ACROSS CENTRAL IOWA.
EXPECT THAT SKIES WILL BE CLEAR THROUGH THE NIGHT WITH HIGH LEVEL
CLOUD COVER COMING IN TOMORROW MORNING AS THE MID LEVEL SHORT WAVE
TROUGH LIFTS TO THE NORTHEAST. LOW LEVEL WARM AIR ADVECTION WILL
BE KICKING IN TONIGHT WITH 850MB TEMPERATURES RISING FROM AROUND
6C TO 10C BY DAYBREAK. WHILE THE CLEAR SKIES AND LIGHT WINDS WILL
LEAD TO IDEAL RADIATIONAL COOLING CONDITIONS IN NORTH CENTRAL
WISCONSIN...THINKING IS THAT THE WARMING LOW LEVEL TEMPERATURES
WILL KEEP ANY FROST DEVELOPMENT RATHER PATCHY AND MAINLY IN THE
LOW LYING AREAS. SINCE IT IS NOT LOOKING TO BE VERY
WIDESPREAD...WILL NOT BE ISSUING A FROST ADVISORY FOR TONIGHT.
AS THE MID LEVEL TROUGH LIFTS NORTH TOMORROW...THE QUESTION IS IF
ANY RAIN SHOWERS WILL BE ABLE TO REACH THE GROUND DUE TO A
SUBSTANTIAL DRY LAYER AT 800MB. AS THIS LAYER CONTINUES TO BE
PRECIPITATED INTO...IT WILL EVENTUALLY SATURATE OUT THOUGH
INSTABILITY LOOKS VERY LOW THROUGH THE AFTERNOON. HAVE GONE WITH
AN INCREASING CHANCE OF RAIN SHOWERS FROM SOUTHWEST TO NORTHEAST
THROUGH THE AFTERNOON TO FOLLOW ALONG WITH THE PATH OF THE TROUGH.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 309 PM CDT MON SEP 16 2013
THE BETTER SHOT FOR SEEING ANY RAIN WILL COME IN TUESDAY NIGHT AS
LOW LEVEL MOISTURE TRANSPORT INCREASES WITH THE NOSE OF THE
925-850MB JET POKING INTO THE REGION. 0-3KM MUCAPE INCREASES TO
AROUND 500-1000J/KG AS WELL WHICH SHOULD LEAD TO SOME ISOLATED TO
SCATTERED THUNDERSTORMS OVERNIGHT. CURRENT THINKING IS THAT THE
HIGHEST RAINFALL WILL LIKELY BE ACROSS NORTHEAST IOWA WHERE UP TO
A HALF INCH OF ACCUMULATION IS POSSIBLE.
AS THE LOW LEVEL JET WEAKENS AND THE MID LEVEL SHORTWAVE TRACKS TO
THE NORTHEAST DURING THE LATE MORNING/AFTERNOON ON
WEDNESDAY...THINK THAT THERE WILL BE A BREAK IN THE RAIN ON
WEDNESDAY. HAVE BACKED DOWN ON PRECIPITATION CHANCES IN THE
AFTERNOON BUT THEN BRING THEM BACK UP AGAIN WEDNESDAY NIGHT AS THE
LOW LEVEL JET DEVELOPS AGAIN WITH ITS NOSE FOCUSED ON THE REGION.
THE THREAT FOR SEVERE WEATHER LOOKS LOW FOR TUESDAY NIGHT INTO
THURSDAY MORNING AS THE SHEAR AND INSTABILITY PROFILES LOOK
UNIMPRESSIVE. GOING INTO THURSDAY AFTERNOON...THE TIMING OF A COLD
FRONT PASSAGE IS TRENDING FASTER AND LOOKS LIKE IT WILL COME
THROUGH THE REGION DURING MID TO LATE AFTERNOON AS A CLOSED MID
LEVEL LOW APPROACHES FROM THE WEST. WITH SURFACE DEW POINTS
INCREASING TO THE UPPER 60S AHEAD OF THE FRONT...MODIFIED 16.12Z
NAM/GFS SOUNDINGS SHOW ABOUT 2000-3000J/KG OF MUCAPE DEVELOPING
AHEAD OF THE FRONT. THIS WARM SECTOR LOOKS LIKE IT IS CAPPED OFF
BY A 850MB WARM LAYER...WHICH DOES WEAKEN THE CLOSER YOU GET TO
THE FRONT. WHILE THE HIGHEST 0-6KM SHEAR STAYS BEHIND THE SURFACE
FRONT...FORECAST SOUNDINGS FROM THE 16.12Z NAM/GFS BOTH SHOW SOME
DECENT 0-3KM UNIDIRECTIONAL SHEAR AT ABOUT 30KTS WHICH COULD BE
FAVORABLE FOR SOME BOWING SEGMENTS. WILL HAVE TO MONITOR THE
TIMING OF THE FROPA TIMING AS IT HAS BOUNCED AROUND THE PAST FEW
DAYS BUT DOES SEEM TO BE SETTLING DOWN ON MID AFTERNOON AS SOME OF
THE SHORTER RANGE MODELS PICK UP ON IT. EXPECT THAT ANY CONVECTION
WOULD DEVELOP RIGHT OUT AHEAD OF THE FRONT WHERE THE CAP WEAKENS
YET INSTABILITY STAYS HIGH ALONG WITH THE DEEP LIFT.
AFTER THE FRONT MOVES THROUGH BY THURSDAY NIGHT...IT WILL JUST BE
ANOTHER STRETCH OF BELOW NORMAL TEMPERATURES GOING THROUGH NEXT
WEEKEND WITH DRY CONDITIONS AS A RIDGE OF HIGH PRESSURE BUILDS
ACROSS THE REGION WITH THE NEXT SYSTEM NOT COMING IN UNTIL PERHAPS
LATE ON MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1236 PM CDT MON SEP 16 2013
HIGH PRESSURE OVER NORTHERN WISCONSIN HAS KEPT SKIES MAINLY CLEAR
ACROSS MUCH OF WESTERN WISCONSIN AND SOUTHEAST MINNESOTA. THERE
IS AN EXPANSIVE AREA OF MVFR CLOUDS ACROSS MUCH OF IOWA. THESE
CLOUDS ARE ASSOCIATED WITH SOME LOW LEVEL MOISTURE WRAPPING AROUND
THE PERIPHERY OF THIS HIGH. THE RAP IS HANDLING THESE CLOUDS
FAIRLY WELL AND IT SHOWS THAT THE NORTHERN EXTENT OF THESE CLOUDS
WILL GRADUALLY DISSIPATE THIS AFTERNOON AND THEY WILL NOT AFFECT
EITHER TAF SITE. A 20-30K DECK OF CLOUDS WILL MOVE INTO THE AREA
AFTER 17.09Z...AND THEN GRADUALLY LOWER TO AROUND 12K FEET WEST OF
THE MISSISSIPPI RIVER LATE TUESDAY MORNING.
THE EAST WINDS WILL REMAIN GENERALLY LESS THAN 5 KNOTS THROUGH
THIS EVENING...AND THEN SHIFT TO THE SOUTHEAST AND INCREASE INTO
THE 5 TO 10 KNOTS FOR LATE TONIGHT AND TUESDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1237 PM CDT MON SEP 16 2013
.UPDATE...
ISSUED AT 747 AM CDT MON SEP 16 2013
WILL ALLOW THE FROST ADVISORY TO EXPIRE AS SCHEDULED AT 8 AM.
TEMPERATURES WILL QUICKLY WARM INTO THE 40S ALLOWING THE FROST TO
DISSIPATE BY MID MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 236 AM CDT MON SEP 16 2013
MAIN FORECAST CONCERNS ARE ON LOW TEMPERATURES TONIGHT WITH THE
POTENTIAL FOR AREAS OF FROST OVER CENTRAL INTO NORTHERN WISCONSIN.
FOCUS THEN TURNS TO SHOWER AND THUNDERSTORM CHANCES LATE TUESDAY
THROUGH THURSDAY NIGHT.
LATEST SURFACE OBSERVATIONS SHOWED HIGH PRESSURE BUILDING INTO THE
WESTERN GREAT LAKES AND UPPER MISSISSIPPI RIVER VALLEY. A STRATUS
DECK LINGERED OVER PORTIONS OF SOUTHERN WISCONSIN THROUGH NORTHEAST
IOWA. THE STRATUS SHOULD GRADUALLY DISSIPATE THIS MORNING AS THE
HIGH BUILDS IN.
THE HIGH WILL BE IN CONTROL ACROSS THE REGION TODAY PROVIDING MOSTLY
SUNNY SKIES AND COOL HIGH TEMPERATURES. PLAN ON HIGHS RANGING FROM
THE THE LOWER 60S OVER NORTH CENTRAL WISCONSIN TO THE MID TO UPPER
60S ACROSS NORTHEAST IOWA. WILL HAVE TO KEEP A VERY CLOSE EYE ON
DEW POINTS TODAY UNDER PEAK MIXING. DRIER AIR ALOFT COULD LEAD TO
AFTERNOON DEW POINTS FALLING INTO THE LOWER 30S TO POSSIBLY THE
UPPER 20S OVER PORTIONS OF CENTRAL INTO WEST CENTRAL WISCONSIN.
THIS WOULD PRODUCE RELATIVE HUMIDITY VALUES IN THE IN THE 25 TO 30
PERCENT RANGE. THE HIGH WILL START TO SLIDE EAST LATE TONIGHT.
MOSTLY CLEAR SKIES WILL LEAD TO ANOTHER NIGHT OF CHILLY OVERNIGHT
LOWS AND THE POTENTIAL FOR AREAS OF FROST ACROSS CENTRAL
WISCONSIN. PLAN ON OVERNIGHT LOWS RANGING FROM THE LOWER 30S OVER
NORTH CENTRAL WISCONSIN TO THE LOWER TO MID 40S ACROSS NORTHEAST
IOWA. A FROST ADVISORY MAY BE NEEDED FOR LOCATIONS ALONG AND
NORTHEAST OF THE INTERSTATE 94 CORRIDOR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 236 AM CDT MON SEP 16 2013
THE HIGH WILL SLIDE EAST OF THE REGION TUESDAY INTO WEDNESDAY AS A
SURFACE TROUGH EDGES EAST OUT OF THE PLAINS. THIS WILL PRODUCE
SOUTHERLY FLOW OVER THE UPPER MISSISSIPPI RIVER VALLEY USHERING IN A
MOIST AIRMASS...WITH PRECIPITABLE WATER VALUES INCREASING TO 1.4 TO
1.6 INCHES. ALSO...FLOW ALOFT WILL START TO TURN SOUTHWEST BRINGING
A SERIES OF SHORTWAVE TROUGHS OVER THE REGION. 850 MB MOISTURE
TRANSPORT INCREASES ALONG AND WEST OF THE MISSISSIPPI RIVER LATE
TUESDAY AFTERNOON THEN CONTINUES TO INCREASE AND FOCUSES ACROSS MUCH
OF THE FORECAST AREA TUESDAY NIGHT. SHOWERS AND THUNDERSTORMS ARE
LIKELY ACROSS MUCH OF THE AREA FROM TUESDAY NIGHT INTO EARLY
WEDNESDAY MORNING. THE MOIST AIRMASS AND SOUTHWEST FLOW WILL PERSIST
OVER THE REGION WEDNESDAY INTO WEDNESDAY NIGHT WITH CONTINUED
CHANCES FOR SHOWERS AND THUNDERSTORMS. A VIGOROUS TROUGH MOVES ACROSS
THE NORTHERN PLAINS ON WEDNESDAY AND IS EXPECTED TO PUSH INTO THE
UPPER MISSISSIPPI RIVER VALLEY THURSDAY INTO THURSDAY NIGHT.
MEANWHILE SURFACE LOW PRESSURE WILL DEEPEN OVER SOUTHWEST
ONTARIO...LIFTING NORTHEAST TOWARD HUDSON BAY THURSDAY NIGHT INTO
EARLY FRIDAY MORNING. THIS WILL DRIVE A COLD FRONT ACROSS THE AREA
BRINGING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WITH IT. MUCH OF
THE STRONGER SHEAR LAGS BEHIND THE FRONT INITIALLY LATE THURSDAY
AFTERNOON BUT THEN APPEARS TO CATCH UP THURSDAY EVENING AS THE FRONT
MOVES INTO THE REGION. WILL HAVE TO KEEP A CLOSE WATCH ON THE
POTENTIAL FOR STRONG TO PERHAPS SEVERE THUNDERSTORMS. THE TIMING OF
THE COLD FRONT ACROSS THE AREA WOULD BE UNFAVORABLE FOR SEVERE
WEATHER BUT GIVEN THE DYNAMICS OF THE SYSTEM CANNOT RULE SEVERE
WEATHER OUT AT THIS TIME. THE UPPER LOW LOOKS TO TRACK ACROSS
SOUTHERN CANADA OR NORTHERN WISCONSIN FRIDAY INTO FRIDAY NIGHT
EFFECTIVELY DRY SLOTTING THE FORECAST AREA. THIS WILL LEAD TO
BREEZY WESTERLY WINDS ACROSS THE FORECAST AREA AND PARTLY TO MOSTLY
SUNNY SKIES. AFTER A BRIEF WARM UP WEDNESDAY INTO THURSDAY...WITH
HIGHS CLIMBING INTO THE UPPER 70S TO LOWER 80S...LOOK FOR HIGH
TEMPERATURES TO FALL BACK INTO THE 70S ON FRIDAY. HIGH PRESSURE
SHOULD GRADUALLY BUILD IN LATE FRIDAY INTO THE WEEKEND PROVING DRY
AND QUIET WEATHER. WILL HAVE TO KEEP A CLOSE EYE ON THE POTENTIAL
FOR SOME RAIN SHOWERS OVER FAR NORTHERN WISCONSIN FRIDAY NIGHT INTO
EARLY SATURDAY MORNING WITH THE PASSAGE OF THE UPPER TROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1236 PM CDT MON SEP 16 2013
HIGH PRESSURE OVER NORTHERN WISCONSIN HAS KEPT SKIES MAINLY CLEAR
ACROSS MUCH OF WESTERN WISCONSIN AND SOUTHEAST MINNESOTA. THERE
IS AN EXPANSIVE AREA OF MVFR CLOUDS ACROSS MUCH OF IOWA. THESE
CLOUDS ARE ASSOCIATED WITH SOME LOW LEVEL MOISTURE WRAPPING AROUND
THE PERIPHERY OF THIS HIGH. THE RAP IS HANDLING THESE CLOUDS
FAIRLY WELL AND IT SHOWS THAT THE NORTHERN EXTENT OF THESE CLOUDS
WILL GRADUALLY DISSIPATE THIS AFTERNOON AND THEY WILL NOT AFFECT
EITHER TAF SITE. A 20-30K DECK OF CLOUDS WILL MOVE INTO THE AREA
AFTER 17.09Z...AND THEN GRADUALLY LOWER TO AROUND 12K FEET WEST OF
THE MISSISSIPPI RIVER LATE TUESDAY MORNING.
THE EAST WINDS WILL REMAIN GENERALLY LESS THAN 5 KNOTS THROUGH
THIS EVENING...AND THEN SHIFT TO THE SOUTHEAST AND INCREASE INTO
THE 5 TO 10 KNOTS FOR LATE TONIGHT AND TUESDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...04
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1205 PM CDT MON SEP 16 2013
.UPDATE...QUIET DAY WITH SFC HIGH PRESSURE JUST ABOUT CENTERED
OVER EASTERN LAKE SUPERIOR. VIS SAT SHOWS LAKE EFFECT DRIVEN
CLOUDS STREAMING INTO THE LAKE SHORE COUNTIES FROM LAKE MICHIGAN
AND GREEN BAY...AND DIURNALLY DRIVEN CU DEVELOPING IN EASTERN
WISCONSIN.
THE GOES-R PG ABI SYNTHETIC SAT IMAGERY BASED OFF THE NSSL WRF IS
CAPTURING MUCH OF THE LAKE EFFECT DRIVEN CLOUDS. THOUGH NOT SO
WELL WITH THE LOW LEVEL CLOUDS IN IA AND IL OR THE DIURNAL CU THAT
IS DEVELOPING. RAP BUFKIT THERMODYNAMIC DIAGRAMS FURTHER SUPPORT
THE DEVELOPMENT OF DIURNAL CU GIVEN LINGERING LOW-LEVEL MOISTURE
AND THE TEMPERATURE PROFILES.
CONSIDERING THE QUICK DEVELOPMENT ALREADY...EXPECT ADDITIONAL CU
TO DEVELOP ACROSS THE FORECAST AREA FROM EAST TO WEST. THIS WILL
COINCIDE WITH THE LAKE EFFECT DRIVEN CLOUDS PUSHING WEST WITH
TIME. AS SUCH...INCREASED SKY COVER IN THE FORECAST FOR TODAY AND
UPDATE THE SKY COVER FORECAST TRENDS.
ET
&&
.AVIATION/18Z TAFS/...MVFR/VFR CEILINGS ARE EXPECTED THIS
AFTERNOON...WITH VFR CONDITIONS TONIGHT AND TUESDAY. LOW CONFIDENCE
WITH MVFR CLOUDS MOVING INTO THE AREA LATER TONIGHT INTO TUESDAY.
HIGH PRESSURE WILL SHIFT SOUTHEAST ACROSS THE WESTERN GREAT LAKES
REGION THIS AFTERNOON INTO TUESDAY. GUSTY NORTHEAST WINDS WILL
LINGER AT THE EASTERN TAF SITES THIS AFTERNOON...WITH WEAKER WINDS
AT MADISON. MVFR/VFR CEILINGS WITH DIURNAL CUMULUS AND LAKE EFFECT
CLOUDS WILL LINGER THIS AFTERNOON...BEFORE DISSIPATING BY EARLY
EVENING.
WINDS WILL VEER TO THE EAST AND REMAIN LIGHT TONIGHT...AND
SOUTHEAST AND INCREASE A BIT ON THURSDAY. LOW CONFIDENCE WITH MVFR
CEILINGS MOVING INTO THE AREA LATER TONIGHT INTO TUESDAY MORNING
FROM THE SOUTHEAST. WILL NOT MENTION THE MVFR CEILINGS IN TAFS AT
THIS TIME.
WOOD
&&
.MARINE...SMALL CRAFT ADVISORY CONTINUES FOR THE NEARSHORE WATERS
OF LAKE MICHIGAN THIS AFTERNOON INTO THIS EVENING. NORTHEAST WINDS
WILL CONTINUE TO GUST TO AROUND 22 KNOTS INTO THE EARLY AFTERNOON
HOURS. WINDS WILL THEN GRADUALLY WEAKEN INTO THE EVENING...AS THE
PRESSURE GRADIENT WEAKENS AND LOW LEVEL MIXING SUBSIDES.
HIGH WAVES OF 4 TO 8 FEET WILL REMAIN HIGH THROUGH THE
AFTERNOON...BEFORE GRADUALLY SUBSIDING THIS EVENING. MAY HAVE TO
EXTEND SMALL CRAFT ADVISORY IN THE NORTHERN TWO MARINE ZONES INTO
THE EVENING TO ACCOUNT FOR POSSIBLE LINGERING HIGH WAVES.
A SMALL CRAFT ADVISORY MAY BE NEEDED FOR TUESDAY INTO WEDNESDAY
NIGHT...WITH ONSHORE WINDS GENERATING HIGH WAVES. TIGHTENING
PRESSURE GRADIENT WITH WARMER AIRMASS MOVING INTO THE REGION MAY
BRING STRONG ENOUGH ONSHORE WINDS TO GENERATE THE HIGH WAVES.
WOOD
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT MON SEP 16 2013/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
COLD ADVECTION LOW CLOUDS GRADUALLY ERODING FROM NORTH TO SOUTH AS
DRY AIR WORKS INTO THE REGION AHEAD OF STRONG HIGH PRESSURE BUILDING
ACROSS WISCONSIN THIS MORNING. MODELS ARE IN GENERAL AGREEMENT THAT
MOST PLACES AWAY FROM THE LAKE MI COUNTIES WILL BE SEE SUNSHINE BY
OR SHORTLY AFTER SUNRISE. TRAJECTORIES AND ELEVATED DELTA-T/S WILL
KEEP PLENTY OF CLOUDS AND AN ISOLATED THREAT OF LAKE EFFECT SHOWERS
IN THE FAR SOUTHEAST THROUGH THE MORNING. THE CLOUDS SHOULD
GRADUALLY ERODE ACROSS THIS AREA BY EARLY AFTERNOON. DESPITE THE
SUNSHINE...TEMPS WILL BE ON THE CHILLY SIDE...ONLY THE LOWER TO MID
60S.
ALL QUIET TONIGHT...BUT COLD WITH LOWS IN THE UPPER 30S TO LOWER 40S
AWAY FROM THE LAKE. AN ONSHORE FLOW WILL KEEP TEMPS WARMER BY THE
LAKE MICHIGAN SHORE.
TUESDAY...FORECAST CONFIDENCE HIGH.
HIGH PRESSURE OVER THE GREAT LAKES WILL DRIFT EAST. LOOK FOR GRADUAL
WARMING WITH SOUTHEAST WINDS WITH RETURN FLOW AROUND THE HIGH. THE
SOUTHEAST WINDS WILL KEEP TEMPS LOWER IN THE MID 60S NEAR THE
LAKESHORE. 925MB TEMPS WILL ONLY BE AROUND 14C INLAND...SO MAX TEMPS
WILL BE LIMITED TO AROUND 70.
QUITE A STRONG MID LEVEL SHORTWAVE TROUGH WILL CROSS WI TUE
AFTERNOON...BUT THE ATMOSPHERE WILL BE TOO DRY FOR ANY PRECIP.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
THAT INITIAL SHORTWAVE MOVES OFF TO THE EAST BUT A WEAKER SHORTWAVE
WILL APPROACH WI TUE NIGHT INTO WED MORNING AND COINCIDE WITH THE
NOSE OF A LOW LEVEL JET AND 850MB WARM AIR ADVECTION TO PRODUCE
ELEVATED SHOWER AND ISOLATED THUNDERSTORM CHANCES. PRECIPITABLE
WATER VALUES SURGE UP TO AROUND 1.5 WHICH IS 2 STANDARD DEVIATIONS
ABOVE NORMAL. OVERALL FORCING IS PRETTY WEAK SO TRENDED POPS
DOWNWARD...ESPECIALLY WED AFTERNOON.
DESPITE A GOOD DEAL OF CLOUD COVER...TEMPS SHOULD CREEP UP INTO THE
MID/UPPER 70S.
LONG TERM...
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM.
A DEEP MID LEVEL TROUGH WILL DIG ACROSS THE NORTHERN PLAINS MID WEEK
AND THE ASSOCIATED SURFACE LOW WILL CROSS NORTHERN NORTH DAKOTA WED
NIGHT. THE HIGH PRECIPITABLE WATER IN THE WARM SECTOR...NOSE OF THE
LLJ AND WEAK RIPPLES IN THE 500MB FLOW COULD LEAD TO ELEVATED
THUNDERSTORMS. THERE IS UNCERTAINTY IN THE TIMING OF THE
SHORTWAVE...SO NAM AND GFS TAPER OFF THUNDERSTORMS DURING THE DAY
THU WHILE THE ECMWF KEEPS THEM GOING. THE CANADIAN MODEL IS RIGHT IN
BETWEEN. WHILE WED NIGHT LOOKS LIKE A DECENT CHANCE FOR SOME
PRECIP...COVERAGE IS STILL QUESTIONABLE. LOWERED FORECAST POPS A
LITTLE.
THURSDAY NIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH.
THE ASSOCIATED LEADING SURFACE TROUGH OF THE OCCLUDING SYSTEM WILL
REACH SOUTH CENTRAL WI AROUND 00Z FRI. THIS FEATURE IS OUT AHEAD OF
THE MAIN UPPER TROUGH/VORT MAX. WEAKER SHORTWAVE ENERGY AND THE
ENTRANCE REGION OF THE UPPER JET WILL SUPPORT THUNDERSTORMS.
ASSUMING DEWPOINTS GET INTO THE UPPER 60S ON THU...THERE COULD BE
1500 J/KG OF CAPE THU EVENING. CAPE DWINDLES QUICKLY THU NIGHT...AND
SHEAR REMAINS FAIRLY LOW...SO ANY STRONGER STORMS COULD PRODUCE
HIGHER WIND GUSTS...BUT NOT EXPECTING SEVERE. NONETHELESS...THIS
APPEARS TO BE OUR NEXT BEST CHANCE FOR MORE WIDESPREAD THUNDERSTORM
ACTIVITY.
FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
AN UPPER LEVEL RIDGE WILL BUILD INTO THE NORTHERN PLAINS AS THE
STRONG UPPER LOW MOVES TOWARD THE NORTHEAST. THIS WILL BRING QUIET
WEATHER TO SOUTHERN WI FOR THE WEEKEND.
CLOUDS AND POSSIBLY A FEW LIGHT SHOWERS COULD LINGER FRIDAY MORNING
AND PAST MODEL RUNS HAVE HINTED AT CYCLONIC FLOW HANGING AROUND THE
UPPER GREAT LAKES THROUGH AS LATE AS SATURDAY...SO WILL NEED TO KEEP
AN EYE ON THIS. THE ECMWF WOULD SUGGEST WARMER TEMPS FOR SATURDAY
AND SUNDAY THAN THE GFS.
THE WEATHER WILL REMAIN QUIET UNTIL THE NEXT LOW PRESSURE SYSTEM
MOVES THROUGH THE NORTHERN PLAINS AND REACHES WI MONDAY
AFTERNOON/EVENING.
AVIATION/12Z TAFS/...
MORNING LOW CLOUDS WILL CLEAR OUT QUICKLY EARLY THIS MORNING AWAY
FROM LAKE MICHIGAN. AN ONSHORE NORTHEAST WIND FLOW AND ELEVATED
DELTA-T/S OVER THE LAKE WILL KEEP THE MVFR CIGS IN KMKE/KENW/KUES
THROUGH MUCH OF THE MORNING...THEN CLEARING DURING THE AFTERNOON.
VFR CONDITIONS WILL THEN CONTINUE THROUGH TONIGHT.
MARINE...
SMALL CRAFT ADVISORY CONTINUES FOR THE NEARSHORE WATERS INTO THIS
EVENING. BRISK NORTHEAST WINDS AND WAVES TO 4 TO 7 FEET WILL
CONTINUE INTO THE AFTERNOON. THE WINDS AND WAVES WILL GRADUALLY
DIMINISH DURING THE AFTERNOON...FALLING BELOW ADVISORY LEVELS THIS
EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL 6 PM CDT THIS EVENING FOR LMZ643-644.
&&
$$
UPDATE...ET/WOOD
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
TUESDAY THROUGH SUNDAY...MRC