Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/22/13
AREA FORECAST DISCUSSION...CORRECTED
NWS PUEBLO CO
338 PM MDT FRI SEP 20 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 331 PM MDT FRI SEP 20 2013
QUIET WEATHER OVER THE AREA TODAY BENEATH TRANSIENT UPPER RIDGE.
STRATUS HAS CLEARED OUT OF MOST OF THE SE PLAINS...THOUGH COOLER AIR
MASS OVER THE REGION HAS KEPT SE PLAINS CAPPED. STILL WAITING TO
SEE IF SUFFICIENT HEATING WILL OCCUR TO POP A THUNDERSTORM OR TWO
ALONG THE CREST OF THE SOUTHERN SANGRES...AND PERHAPS ACROSS THE
EASTERN SAN JUAN MOUNTAINS...BUT SO FAR CONVECTION HAS HAD A HARD
TIME GETTING GOING...WITH AIRMASS LOOKING TOO DRY ACROSS THE SW MTS
WHERE DEW POINTS HAVE DROPPED INTO THE 20S...AND TOO CAPPED AND COOL
FOR THE SOUTHERN SANGRES. EACH SUCCESSIVE HRRR RUN HAS BACKED OFF
WITH QPF FOR THOSE AREAS...SO HAVE TRIMMED BACK POPS INTO THE SILENT
CATEGORY.
SOUTHWEST FLOW INCREASES OVER THE AREA FOR SUNDAY. NAM12 PICKS UP
SOME LOW LEVEL MOISTURE AND GENERATES SOME OROGRAPHIC SHOWERS ACROSS
THE SOUTHWEST MTS EARLY SATURDAY MORNING. THIS COULD BE A BIT
OVERDONE...BUT GFS HINTS AT THIS TOO SO WILL MAINTAIN SOME ISOLATED
SHOWERS FOR THAT AREA. BY AFTERNOON...MODELS SHOW SOME ISOLATED
THUNDERSTORMS SPREADING NORTH AND EASTWARD INTO THE SAWATCH AND
MOSQUITO RANGES AND THE SANGRES. OTHERWISE...TEMPERATURES SHOULD
REBOUND NICELY BACK INTO THE 80S FOR THE SE PLAINS WITH A MIX OF 60S
AND 70S FOR THE MOUNTAIN AREAS. SOUTHERLY WINDS WILL INCREASE
ACROSS THE AREA AS THE LEE TROF DEEPENS AHEAD OF THE NEXT
APPROACHING TROF. STRONGEST WINDS WILL BE ACROSS THE HIGHER PEAKS
IN THE AFTERNOON AND ALONG THE FAR EASTERN BORDER ON THE EAST SIDE
OF THE SFC TROF AXIS. BOTH AREAS COULD SEE GUSTS IN THE 25-30 KT
RANGE. -KT
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 331 PM MDT FRI SEP 20 2013
.SATURDAY NIGHT THROUGH SUNDAY NIGHT...TROUGH MOVES ACROSS THE
REGION SUNDAY AFTERNOON AND EVENING. MODELS HAVE SOME DIFFERENCES
ON THE STRENGTH OF THE TROUGH. THE NAM IS THE WEAKEST WHILE THE EC
IS THE STRONGEST. MAIN CONCERNS WITH TROUGH PASSAGE WOULD BE SNOW
LEVELS ALONG THE CONTINENTAL DIVIDE AND WINDS OVER THE EASTERN
MOUNTAINS AND PLAINS. MOST OF THE PRECIPITATION OVER THE
CONTINENTAL DIVIDE REGION OCCURS AHEAD OF THE COLDEST AIR
ALOFT...AND SNOW IS MOSTLY LIMITED TO THE HIGHEST PEAKS. SNOW
LEVELS COULD FALL BELOW TREE LINE BEFORE PRECIPITATION ENDS FOR
SOME ACCUMULATIONS. IF THE TROUGH IS DEEPER...MORE SNOW COULD FALL
BELOW TREE LINE. THE BEST CHANCES FOR SNOW BELOW TREELINE WILL BE
SUNDAY EVENING. SECOND CONCERN WILL BE WINDS. GUSTY SOUTH TO
SOUTHWEST WINDS WILL DEVELOP AHEAD OF THE TROUGH SUNDAY ON THE
PLAINS. GFS AND EC HAVE THE 500MB TROUGH CUT OFF BRIEFLY AS IT
LIFTS NORTHEAST INTO NEBRASKA. HAVE SOME CONCERNS FOR A BRIEF
PERIOD OF STRONG WINDS SUNDAY EVENING OVER THE EASTERN MOUNTAINS
AND INTERSTATE 25 CORRIDOR. MODELS DO NOT HAVE STRONG WINDS AT
THIS TIME...BUT HAVE SEEN WINDY CONDITIONS WITH SIMILAR PATTERNS.
.MONDAY THROUGH WEDNESDAY...DRY AND WARM PATTERN DEVELOPS BEHIND
DEPARTING TROUGH AND AHEAD OF THE NEXT TROUGH. BREEZY TO WINDY
CONDITIONS ARE POSSIBLE ON WEDNESDAY AS SOUTHWEST FLOW ALOFT
STRENGTHENS AHEAD OF THE NEXT TROUGH MOVING INTO THE PACIFIC
NORTHWEST.
.THRUSDAY AND FRIDAY...EC AND GFS HAVE THE TROUGH OVER THE
NORTHWEST US MOVING NORTHEASTWARD ACROSS THE NORTHERN ROCKIES.
REGION WILL BE ON THE SOUTHERN END OF THE TROUGH. BOTH MODELS
SUGGEST A COLD FRONT IN THE REGION...WITH THE POTENTIAL FOR SOME
UPSLOPE ON THE EASTERN PLAINS. TOO EARLY TO GET VERY SPECIFIC ON
DETAILS SUCH AS THE LOCATION OF THE FRONT...STRENGTH OF EASTERLY
UPSLOPE FLOW AND STRENGTH OF THE TROUGH. GRIDS HAVE A MODEST
COOLING TREND WITH SOME ISOLATED POPS. --PGW--
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 331 PM MDT FRI SEP 20 2013
VFR CONDITIONS EXPECTED AT TAF SITES THROUGH THE NIGHT
WITH PATCHY REMNANT CLOUD COVER AROUND KCOS DISSIPATING BY 00Z.
EXPECT CLEAR SKIES OVERNIGHT THOUGH KALS COULD SEE A RETURN OF SOME
PATCHY GROUND FOG TOWARDS 12Z. FOR NOW HAVE KEPT VIS IN THE MVFR
CATEGORY FOR A COUPLE HOURS AROUND SUNRISE...BUT VIS COULD VERY WELL
DROP INTO THE IFR RANGE IF SKIES REMAIN SUFFICIENT CLEAR.
OTHERWISE...VFR CONDITIONS WILL CONTINUE INTO SATURDAY WITH WINDS
INCREASING FROM THE SOUTH DURING THE AFTERNOON WITH SPEEDS 10-15
KTS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...PGW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
332 PM MDT FRI SEP 20 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 331 PM MDT FRI SEP 20 2013
UIET WEATHER OVER THE AREA TODAY BENEATH TRANSIENT UPPER RIDGE.
STRATUS HAS CLEARED OUT OF MOST OF THE SE PLAINS...THOUGH COOLER AIR
MASS OVER THE REGION HAS KEPT SE PLAINS CAPPED. STILL WAITING TO
SEE IF SUFFICIENT HEATING WILL OCCUR TO POP A THUNDERSTORM OR TWO
ALONG THE CREST OF THE SOUTHERN SANGRES...AND PERHAPS ACROSS THE
EASTERN SAN JUAN MOUNTAINS...BUT SO FAR CONVECTION HAS HAD A HARD
TIME GETTING GOING...WITH AIRMASS LOOKING TOO DRY ACROSS THE SW MTS
WHERE DEW POINTS HAVE DROPPED INTO THE 20S...AND TOO CAPPED AND COOL
FOR THE SOUTHERN SANGRES. EACH SUCCESSIVE HRRR RUN HAS BACKED OFF
WITH QPF FOR THOSE AREAS...SO HAVE TRIMMED BACK POPS INTO THE SILENT
CATEGORY.
SOUTHWEST FLOW INCREASES OVER THE AREA FOR SUNDAY. NAM12 PICKS UP
SOME LOW LEVEL MOISTURE AND GENERATES SOME OROGRAPHIC SHOWERS ACROSS
THE SOUTHWEST MTS EARLY SATURDAY MORNING. THIS COULD BE A BIT
OVERDONE...BUT GFS HINTS AT THIS TOO SO WILL MAINTAIN SOME ISOLATED
SHOWERS FOR THAT AREA. BY AFTERNOON...MODELS SHOW SOME ISOLATED
THUNDERSTORMS SPREADING NORTH AND EASTWARD INTO THE SAWATCH AND
MOSQUITO RANGES AND THE SANGRES. OTHERWISE...TEMPERATURES SHOULD
REBOUND NICELY BACK INTO THE 80S FOR THE SE PLAINS WITH A MIX OF 60S
AND 70S FOR THE MOUNTAIN AREAS. SOUTHERLY WINDS WILL INCREASE
ACROSS THE AREA AS THE LEE TROF DEEPENS AHEAD OF THE NEXT
APPROACHING TROF. STRONGEST WINDS WILL BE ACROSS THE HIGHER PEAKS
IN THE AFTERNOON AND ALONG THE FAR EASTERN BORDER ON THE EAST SIDE
OF THE SFC TROF AXIS. BOTH AREAS COULD SEE GUSTS IN THE 25-30 KT
RANGE. -KT
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 331 PM MDT FRI SEP 20 2013
.SATURDAY NIGHT THROUGH SUNDAY NIGHT...TROUGH MOVES ACROSS THE
REGION SUNDAY AFTERNOON AND EVENING. MODELS HAVE SOME DIFFERENCES
ON THE STRENGTH OF THE TROUGH. THE NAM IS THE WEAKEST WHILE THE EC
IS THE STRONGEST. MAIN CONCERNS WITH TROUGH PASSAGE WOULD BE SNOW
LEVELS ALONG THE CONTINENTAL DIVIDE AND WINDS OVER THE EASTERN
MOUNTAINS AND PLAINS. MOST OF THE PRECIPITATION OVER THE
CONTINENTAL DIVIDE REGION OCCURS AHEAD OF THE COLDEST AIR
ALOFT...AND SNOW IS MOSTLY LIMITED TO THE HIGHEST PEAKS. SNOW
LEVELS COULD FALL BELOW TREE LINE BEFORE PRECIPITATION ENDS FOR
SOME ACCUMULATIONS. IF THE TROUGH IS DEEPER...MORE SNOW COULD FALL
BELOW TREE LINE. THE BEST CHANCES FOR SNOW BELOW TREELINE WILL BE
SUNDAY EVENING. SECOND CONCERN WILL BE WINDS. GUSTY SOUTH TO
SOUTHWEST WINDS WILL DEVELOP AHEAD OF THE TROUGH SUNDAY ON THE
PLAINS. GFS AND EC HAVE THE 500MB TROUGH CUT OFF BRIEFLY AS IT
LIFTS NORTHEAST INTO NEBRASKA. HAVE SOME CONCERNS FOR A BRIEF
PERIOD OF STRONG WINDS SUNDAY EVENING OVER THE EASTERN MOUNTAINS
AND INTERSTATE 25 CORRIDOR. MODELS DO NOT HAVE STRONG WINDS AT
THIS TIME...BUT HAVE SEEN WINDY CONDITIONS WITH SIMILAR PATTERNS.
.MONDAY THROUGH WEDNESDAY...DRY AND WARM PATTERN DEVELOPS BEHIND
DEPARTING TROUGH AND AHEAD OF THE NEXT TROUGH. BREEZY TO WINDY
CONDITIONS ARE POSSIBLE ON WEDNESDAY AS SOUTHWEST FLOW ALOFT
STRENGTHENS AHEAD OF THE NEXT TROUGH MOVING INTO THE PACIFIC
NORTHWEST.
.THRUSDAY AND FRIDAY...EC AND GFS HAVE THE TROUGH OVER THE
NORTHWEST US MOVING NORTHEASTWARD ACROSS THE NORTHERN ROCKIES.
REGION WILL BE ON THE SOUTHERN END OF THE TROUGH. BOTH MODELS
SUGGEST A COLD FRONT IN THE REGION...WITH THE POTENTIAL FOR SOME
UPSLOPE ON THE EASTERN PLAINS. TOO EARLY TO GET VERY SPECIFIC ON
DETAILS SUCH AS THE LOCATION OF THE FRONT...STRENGTH OF EASTERLY
UPSLOPE FLOW AND STRENGTH OF THE TROUGH. GRIDS HAVE A MODEST
COOLING TREND WITH SOME ISOLATED POPS. --PGW--
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 331 PM MDT FRI SEP 20 2013
VFR CONDITIONS EXPECTED AT TAF SITES THROUGH THE NIGHT
WITH PATCHY REMNANT CLOUD COVER AROUND KCOS DISSIPATING BY 00Z.
EXPECT CLEAR SKIES OVERNIGHT THOUGH KALS COULD SEE A RETURN OF SOME
PATCHY GROUND FOG TOWARDS 12Z. FOR NOW HAVE KEPT VIS IN THE MVFR
CATEGORY FOR A COUPLE HOURS AROUND SUNRISE...BUT VIS COULD VERY WELL
DROP INTO THE IFR RANGE IF SKIES REMAIN SUFFICIENT CLEAR.
OTHERWISE...VFR CONDITIONS WILL CONTINUE INTO SATURDAY WITH WINDS
INCREASING FROM THE SOUTH DURING THE AFTERNOON WITH SPEEDS 10-15
KTS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...PGW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1135 PM MDT THU SEP 19 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 317 PM MDT THU SEP 19 2013
FAIRLY MEAGER CONVECTION OUT THERE SO FAR WITH DEW POINTS
STRUGGLING TO REBOUND ALONG THE NORTHERN PORTIONS OF THE AREA
BEHIND THIS MORNING`S COLD FRONT. THEY ARE SLOWLY CREEPING UP INTO
THE LOWER 40S TO MID 40S ACROSS EL PASO AND PUEBLO COUNTIES AS
WINDS SWING AROUND FROM THE EAST THIS AFTERNOON. FARTHER
EAST...DEW POINTS AT KLHX AND KLAA ARE STILL HOVERING IN THE 50S.
THUS HIGHEST MIXED LAYER CAPES OFF OF SPC MESO ANALYSIS IS RUNNING
AROUND 1000 J/KG ACROSS THE SOUTHEAST PLAINS SOUTH OF HIGHWAY
50...BUT THERE APPEARS TO BE A LITTLE CIN TO OVERCOME YET OUT THAT
WAY. AS THE UPPER TROF TRAILS ACROSS THE AREA THIS EVENING...SHORT
RANGE HIGH RES MODELS (LOCAL 4KM WRF...HRRR AND NAM12) ALL SHOW A
WINDOW FOR SOME ISOLATED SHOWERS AND THUNDERSTORMS ACROSS THE
SOUTHEAST MTS/SPREADING INTO THE ADJACENT PLAINS THROUGH THE
EVENING. WITH FORCING STILL COMING THROUGH ITS HARD TO ARGUE.
HOWEVER...HAVE NOTICED TREND IN HRRR TO DECREASE COVERAGE OF QPF
ACROSS THE SOUTHERN I-25 CORRIDOR WITH EACH RUN. AFTER MIDNIGHT
THINK MOST OF THE ACTIVITY WILL BE DONE...HOWEVER...LOW LEVEL
WINDS SWING AROUND FROM THE SOUTHEAST AND MODEL SOUNDINGS BECOME
DEEPLY SATURATED SUGGESTING POTENTIAL FOR LOTS OF LOW
CLOUDS...FOG...AND EVEN PATCHY DRIZZLE ALONG THE SOUTHERN SLOPES
OF THE PALMER DIVIDE WHERE UPSLOPE WILL BE MAXIMIZED. HAVE THROWN
IN SOME ISOLATED -SHRA AND DRIZZLE FOR THE LATE NIGHT/EARLY
MORNING HOURS ALONG WITH AREAS OF FOG ALONG THE I-25 CORRIDOR.
STRATUS WILL SLOWLY CLEAR ON FRIDAY...THOUGH THINK THAT SOUTHERN
SLOPES OF THE PALMER DIVIDE/COLORADO SPRINGS AREA MAY HANG ON TO
CLOUD COVER THROUGH THE MORNING BEFORE BREAKS START TO APPEAR IN THE
AFTERNOON...AS IS THE TYPICAL PATTERN FOR SOUTHERLY UPSLOPE CASES.
OTHERWISE...MODELS KEEP FORECAST AREA DRY FRIDAY AFTERNOON...WITH SE
PLAINS REMAINING CAPPED. TEMPERATURES SHOULD BE ABOUT A CATEGORY COOLER THAN
THOSE OF TODAY. -KT
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 317 PM MDT THU SEP 19 2013
GENERALLY WARM AND DRY WEATHER STILL ON TRACK FOR THE EXTENDED...WITH
JUST A COUPLE OF STORM SYSTEMS TO CONTEND WITH. THE WEEKEND STARTS
OUT WARM AND DRY. SHOULD SEE 80S OVER THE PLAINS BOTH SAT AND SUNDAY.
GFS MOS CONTINUES TO LOOK TOO WARM FOR THE PLAINS...SO HAVE STAYED ON
THE COOL SIDE OF GUIDANCE...PARTICULARLY SUNDAY AS HIGH CLOUDS START
MOVING IN FROM THE WEST.
SOME MODEL DISCREPANCIES FOR OUR FIRST SHORT WAVE LATE SUNDAY. THE TREND
HAS BEEN TOWARDS A SLIGHTLY DEEPER OR SHARPER TROUGH...WHICH THE
ECMWF HAS BEEN ADVERTISING FOR A WHILE NOW. THE GFS NOW LOOKS
COOLER AND WETTER...AND WOULD BRING SEVERAL INCHES OF SNOW TO THE AREA
ABOVE 9K FEET SUNDAY NIGHT. THE NAM IS CONSIDERABLY WARMER AND
PROBABLY WOULD JUST LEAD TO TRACE SNOW AMOUNTS. THE TRUTH LIKELY IS
SOMEWHERE IN BETWEEN...BUT PROBABLY CLOSER TO THE GFS. SHOULD KNOW
BETTER BY TOMORROW OR FRIDAY IF THE NAM MOVES TOWARD A COOLER
SOLUTION. HAVE BUMPED UP POPS ABOUT 10-20 PERCENT AREA WIDE AS THE
TROUGH MOVES THROUGH SUN NIGHT.
MONDAY AND TUESDAY...THINGS REALLY DRY OUT IN ZONAL FLOW...AND WE
SHOULD SEE SOME REAL PLEASANT FALL WEATHER WITH LOTS OF SUNSHINE
AND TEMPS IN THE 70S-NR 80 FOR THE LOWLANDS AND 60S FOR THE HIGHER
VALLEYS. POPS ESSENTIALLY NIL EVEN FOR THE MTS.
NEXT SYSTEM BEGINS TO TAKE SHAPE ON WED THROUGH THU AS A DEEPER TROUGH
MOVES THROUGH THE PACNW AND INTO THE INTER-MOUNTAIN REGION. STILL PLENTY
OF UNCERTAINTY WITH THE TIMING AND DEPTH OF THIS LOW...BUT THE
TREND FOR A WHILE NOW HAS BEEN FOR IT TO LIFT INTO THE NRN ROCKIES
BY LATE THU OR FRI...WHICH WOULD BRING MOST OF THE PRECIP N OF OUR
CWA AND LEAVE US IN A DRY AND BREEZY CORNER. CERTAINLY DOES NOT
LOOK LIKE A BIG STORM FOR OUR AREA...BUT THE MTS SHOULD SEE AT
LEAST SOME LIGHT SNOWFALL ABOVE 9 OR 10K FEET AS H7 TEMPS DROP
CLOSE TO ZERO BY THE END OF THE WEEK. ROSE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1130 PM MDT THU SEP 19 2013
A LOW STRATUS LAYER IS EXPECTED TO AFFECT KCOS AND KPUB
OVERNIGHT...WITH IFR CONDITIONS AND POSSIBLY SOME DRIZZLE. THE LOW
CLOUDS ARE EXPECTED TO CONTINUE THRU MUCH OF THE MORNING ON
FRIDAY...ESPECIALLY AT KCOS AS A SOUTH WIND DEVELOPS WITH THE
UPSLOPE FLOW POSSIBLY KEEPING A LOW CIG IN THE AREA THRU NOON OR A
LITTLE LATER. EXPECTING VFR CONDITIONS AT KALS THRU 24 HOURS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...ROSE
AVIATION...28
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1016 PM EDT SAT SEP 21 2013
.SYNOPSIS...
SHOWERS AND POSSIBLE THUNDERSTORMS WILL BE ON THE INCREASE AHEAD
OF A COLD FRONT WHICH WILL SWEEP THROUGH NEW ENGLAND TONIGHT
AND SUNDAY. HIGH PRESSURE WILL RETURN FOR MUCH OF NEXT WEEK WITH
DRY WEATHER.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
1030 PM UPDATE...
FIGURING IT LIKELY THAT MANY ARE AWARE OF THE ONGOING SITUATION
AND ATTENDANT SYNOPTICS...WILL COVER BRIEFLY THE MODIFICATIONS TO
THE FORECAST AND TOUCH UPON PREFERRED NEAR-TERM GUIDANCE.
22.18Z NAM AND 22.15Z SREF IS HANDLING THE PRESENT SITUATION WELL.
THE LATEST HRRR HAS BEEN A FEW HOURS SLOWER IN PROGRESSION OF THE
COLD FRONT WITH ATTENDANT RAINS. HAVE MODIFIED POP AND RAINFALL
AMOUNT GRIDS ACCORDINGLY WHILE COLLABORATING WITH SURROUNDING
WFO/S AND RIVER FORECAST CENTERS.
CONCERNING THUNDER...FEW STRIKES APPARENT THE LAST HOUR. SPC
MESONANALYSIS HIGHLIGHTS SOME MLCAPE CREEPING NORTH WITH THE
SOUTHERLY FLOW ACROSS THE MID-ATLANTIC INTO SOUTHERN NEW ENGLAND.
HRRR SUGGESTS SOME ICE WITHIN THE CLOUD MAY YIELD A STRIKE OR TWO.
THUS HAVE KEPT A MENTION OF ISOLATED THUNDER.
BLENDED PRECIPITABLE WATER DERIVED FROM SATELLITES SHOWS AN AREA
OF 1.5 INCH PWATS COINCIDIENT WITH THE COLD FRONT ACROSS NY/PA.
SOME 2 INCH AMOUNTS ARE DEVELOPING OVER THE DELMARVA PENINSULA AND
POINTS SOUTH INTO THE CAROLINAS. HOURLY RAINFALL AMOUNTS WEST HAVE
BEEN LIGHT...BUT A HYDROLOGICAL THREAT REMAINS POSSIBLE. POCKETS
OF HEAVY RAIN PLAUSIBLE AND THUS THE THREAT OF ISOLATED URBAN POOR
DRAINAGE FLOODING PERSISTS. NOT ENOUGH CONFIDENCE FOR A WATCH.
HEAVIEST RAINFALL AMOUNTS MAINLY OVER THE CONNECTICUT VALLEY INTO
SOUTHERN NEW HAMPSHIRE. LINGERING DRY AIR AND SUBSIDENCE NOTING
THE 0Z CHATHAM SOUNDING IS LIKELY GOING TO BE AN ISSUE AS THE
FRONT PUSHES EAST DURING THE NOCTURNAL PERIOD.
SOUTHERLY WINDS REMAINING BREEZY AHEAD OF THE FRONT. DECOUPLING
PER 0Z SOUNDINGS OUT OF ALBANY/CHATHAM IS ALLOWING FOR FASTER FLOW
AT H925-85 PER WSR-88D VAD WIND PROFILES. PUSHING FOR CONTINUED
GUSTY WINDS OVERNIGHT...BUT NOT EXPECTING TOO MUCH MIX-DOWN OF
FASTER MOMENTUM ALOFT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
A COLD FRONT WILL MOVE OFFSHORE DURING THE DAY...BRINGING AN END
TO THE RAINFALL. DRIER AIR ARRIVES DURING THE AFTERNOON AND
OVERNIGHT...RESULTING IN CLEARING WITH DRY WEATHER.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* DRY AND SEASONABLE TEMPERATURES FOR THE FIRST HALF OF THE WEEK
* DRY WEATHER CONTINUES WITH A WARMING TREND FOR THE END OF THE WEEK
CONFIDENCE LEVEL/MODEL GUIDANCE...
HIGH CONFIDENCE IN OVERALL FORECAST TRENDS. 12Z MODELS AND THE
ENSEMBLES ARE IN GOOD AGREEMENT AMONGST THEMSELVES. UPPER LEVEL
LOW WILL CONTINUE TO MEANDER ACROSS THE CANADIAN MARITIMES WHILE A
BLOCKING HIGH SETS UP ACROSS QUEBEC. EXPECT THIS FLOW TO OCCUR
THROUGH MIDWEEK UNTIL THE HIGH PRESSURE STRENGTHENS AS A RESULT OF
THE DIGGING TROUGH OUT WEST. THEREFORE EXPECT GENERALLY A COOL
AND DRY MEDIUM RANGE FORECAST WHILE IN THE EXTENDED APPEARS THAT A
WARM-UP IS POSSIBLE.
DETAILS...
MONDAY THOUGH WEDNESDAY...
COLD POOL ALOFT WILL MOVE ACROSS THE NORTHEAST ON MONDAY AS UPPER
LEVEL LOW MOVES TOWARDS THE MARITIMES. TEMPERATURES WILL STRUGGLE
TO GET INTO THE UPPER 60S AS 850 MB TEMPS WILL REACH BETWEEN
4-6C. BECAUSE OF THIS STRONG COLD POOL EXPECT GUSTY NORTHWEST
WINDS THROUGHOUT THE DAY. AFTER MONDAY...IMPROVING CONDITIONS WILL
OCCUR AS HIGH PRESSURE BUILDS INTO THE REGION. EXPECT DRY WEATHER
AND MODERATING TEMPS THANKS TO WARM AIR ADVECTION. HIGHS WILL
RANGE FROM THE MID 60S TO LOW 70S WITH LOWS IN THE UPPER 30S TO
LOW 40S. THERE IS A SLIGHT CHANCE FOR SOME PATCHY FROST ON MONDAY
NIGHT INTO TUESDAY AS RADIATIONAL COOLING WILL ALLOW FOR TEMPS TO
PLUMMET OVERNIGHT. THIS WILL NEED TO BE WATCH CLOSELY ESPECIALLY
IF HEADLINES ARE NEEDED.
THURSDAY THROUGH SATURDAY...
QUICK MOVING WAVE WILL RIPPLE THROUGH THE FLOW ON THURSDAY
PUSHING THE WIND ALOFT IN A NORTHERLY DIRECTION. THIS WILL ALSO
PUT SOUTHERN NEW ENGLAND ON THE EDGE OF THE RIDGE...SO WE WILL SEE
INCREASING TEMPS BUT NOT AS WARM AS THE GREAT LAKES REGION. THE
CHANCE FOR POSSIBLE BACK DOOR COLD FRONTS ALSO INCREASE IF A UPPER
LEVEL DISTURBANCES MOVES THROUGH THE FLOW. REGARDLESS...INCREASING
TEMPS INTO THE LOW TO MID 70S FOR HIGHS SEEMS LIKELY AT THE END OF
THE WEEK WITH COOLER TEMPS ALONG THE SHORE FROM SEA BREEZE
DEVELOPMENT. DRY WEATHER WILL PREVAIL INTO THE EXTENDED.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
2Z UPDATE...
VFR PRESENTLY WILL GRADUALLY GO DOWNHILL TO IFR-LIFR AROUND
MIDNIGHT. A FEW SPOTS OF VLIFR POSSIBLE WITH DENSE FOG. LOW
CONFIDENCE TSRA. MAINLY RAIN. BLUSTERY SOUTH WINDS THROUGH THE
NIGHT. BEWARE LLWS ISSUES AS WINDS JUST 2 KFT AGL ARE AT 35-40 KTS
PER TAUNTON WFO WSR-88D WIND PROFILER.
WILL SEE GRADUAL IMPROVEMENT AFTER THE MORNING HOURS AND AS THE
ATTENDANT COLD FRONT TO WET WEATHER SLIDES EAST. VFR EXPECTED BY
EVENING AND OVERNIGHT. LIGHTER WESTERLY WINDS COULD PRESENT THE
OPPORTUNITY FOR PATCHY DENSE FOG IN SHELTERED VALLEY REGIMES
/CONNECTICUT RIVER VALLEY...MONADNOCKS...WORCESTER HILLS/.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING.
OUTLOOK...MONDAY THROUGH WEDNESDAY...
MON INTO WED...HIGH CONFIDENCE.
VFR. GUSTY N WINDS TO 20-25 KT ON MONDAY. LIGHT WINDS ON TUESDAY
AND WEDNESDAY WITH POSSIBLE SEA BREEZE DEVELOPMENTS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.
1030 PM UPDATE...
SOUTHERLY FLOW EXPECTED TO BE BLUSTERY THROUGH THE EVENING. WITH
THE NEAR GUSTS TO 25 KTS...WILL EXTEND THE SMALL CRAFT ADVISORY
FOR NARRANGANSETT BAY INTO SUNDAY MORNING...BUT DROP THE ADVISORY
OVER BOSTON HARBOR BY MIDNIGHT. SEAS REMAINING ROUGH BUILDING UP
TO AROUND 6 FEET ON THE OUTER WATERS.
OUTLOOK...MONDAY THROUGH WEDNESDAY...
MON INTO WED...HIGH CONFIDENCE. MAINLY N WINDS...STRONGEST ON MONDAY
WHEN WINDS MAY GUST TO 25 KT WITH LINGERING 5 FT SEAS. SMALL
CRAFT ADVISORIES MAY NEED TO BE EXTENDED INTO MONDAY. WINDS AND
SEAS WILL DROP BELOW SCA TUE/WED.
&&
.HYDROLOGY...
WIDESPREAD SHOWERS WITH POCKETS OF HEAVIER RAIN AND ISOLATED
THUNDERSTORMS WILL SEEP ACROSS THE REGION OVERNIGHT INTO SUNDAY.
WIDESPREAD RAIN TOTALS BETWEEN HALF AND ONE INCHES ARE
LIKELY...WITH A FEW SPOTS /PARTICULARLY IN THE CONNECTICUT RIVER
VALLEY INTO SOUTHERN NEW HAMPSHIRE/ EXCEEDING ONE INCH.
SOME OF THIS RAIN MAY FALL OVER A RELATIVELY SHORT PERIOD OF
TIME...WHICH MAY LEAD TO AN ENHANCED THREAT FOR URBAN AND POOR
DRAINAGE FLOODING. AGAIN THE GREATEST RISK WILL BE OVER THE
CONNECTICUT RIVER VALLEY REGION INTO SOUTHERN NEW HAMPSHIRE...
HOWEVER MORE URBANIZED AREAS IN THE EAST MAY ALSO NEED TO BE
MONITORED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SUNDAY FOR ANZ231>234-251.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ230-
236.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ250-254>256.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...SIPPRELL
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...SIPPRELL/BELK/DUNTEN
MARINE...SIPPRELL/BELK/DUNTEN
HYDROLOGY...SIPPRELL/BELK
AREA FORECAST DISCUSSION
NWS ALBANY NY
1007 PM EDT SAT SEP 21 2013
.SYNOPSIS...
WIDESPREAD SHOWERS ARE EXPECTED TONIGHT AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. THE RAIN MAY BE HEAVY AT TIMES
TONIGHT. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION BY SUNDAY
NIGHT AND IS THEN EXPECTED TO DOMINATE THE WEATHER MUCH OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1007 PM EDT...A COLD FRONT IS MOVING TOWARDS OUR FORECAST
AREA FOR THE OVERNIGHT HOURS. AHEAD OF THIS BOUNDARY IS A BAND OF
LIGHT TO MODERATE RAIN SHOWERS. EARLIER IN THE EVENING...THERE
WERE MORE HEAVIER BURSTS OF RAIN WITHIN THIS BAND AS IT MOVED FROM
WESTERN TO CENTRAL NY...HOWEVER...THE STRONG LOW TO MID LEVEL SW
FLOW AHEAD OF THE DIGGING UPPER LEVEL SHORTWAVE TROUGH HAS
PROBABLY ALLOWED FOR SOME DOWNSLOPING OFF THE HIGH TERRAIN. THIS
HAS WEAKENED A LOT OF THE APPROACHING ACTIVITY MOVING INTO EASTERN
NY. SOME ADDITIONAL SHOWERS ARE DEVELOPING ACROSS THE HUDSON
VALLEY AND INTO WESTERN NEW ENGLAND. THE LATEST 3KM HRRR SHOWS
THIS ACTIVITY DEVELOPING FURTHER AND BECOMING STRONGER AS IT MOVES
EASTWARD INTO NEW ENGLAND...AND THIS AREA MAY BE THE MOST LIKELY
TO SEE ANY HEAVIER BURSTS THROUGH THE OVERNIGHT HOURS. WE WILL
MENTION WIDESPREAD MODERATE RAIN SHOWERS FOR THE ENTIRE
REGION...ESP CONSIDERING HOW OUR PWATS HAVE RISEN TO 1.37 INCHES
ON THE 00Z KALY SOUNDING. MOST AREAS LOOK TO SEE A HALF INCH TO
ONE INCH OF RAIN...WITH LOCALLY HIGHER AMOUNTS OVER THE HIGH
TERRAIN OF WESTERN NEW ENGLAND AND WEST FACING SLOPES OF THE
EASTERN CATSKILLS. WITH LIMITED INSTABILITY AND NO LTG STRIKES
OVER THE LAST 6 HOURS...WE WILL REMOVE MENTION OF THUNDER FROM THE
FORECAST AS WELL. RAIN SHOWERS LOOK TO END FROM WEST TO EAST JUST
PRIOR TO SUNRISE AS THE FRONT CROSSES THE REGION AND THE WINDS
TURN WEST.
FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT THIS TIME...HOWEVER
WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE ON MAJOR RIVERS.
WHAT IS MORE LIKELY IS PONDING OF WATER AND FLOODING OF POOR
DRAINAGE AND LOW LYING AREAS...MAINLY ACROSS WESTERN NEW ENGLAND. CAN
NOT RULE TOTALLY OUT ISOLATED FLASH FLOODING...BUT NOT EXPECTING
IT BASED ON UPSTREAM OBSERVATIONS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
TROUGH AXIS WILL SWING THROUGH SUNDAY AS SHORT WAVE ROTATES THROUGH
BASED OF UPPER LEVEL LOW MOVING ACROSS EASTERN CANADA. PRECIPITATION
WILL TAPER OFF FROM SOUTHWEST TO NORTHEAST DURING THE MORNING HOURS.
THE PRESSURE GRADIENT WILL TIGHTEN UP ACROSS THE REGION SUNDAY AND
WESTERLY WINDS WILL BECOME BRISK USHERING IN A COLDER AIRMASS
AIRMASS. CONDITIONS WILL REALLY BEGIN TO IMPROVE LATER IN THE
AFTERNOON INTO EVENING WITH DECREASING CLOUDS AND WEAKENS WINDS AS
THE PRESSURE GRADIENT LOOSENS ACROSS THE REGION AND HEIGHTS BEGIN TO
RISE.
IT WILL GET COLD AT NIGHT WITH LOWS BOTTOMING OUT MAINLY IN THE 30S.
DESPITE THE COLD TEMPERATURES CONDITIONS WILL BE FAVORABLE FOR
WIDESPREAD FROST DEVELOPMENT AS WE MAINTAIN A NORTHWEST WIND THROUGH
THE OVERNIGHT...WEAKEN TO 5 TO 10 MPH. COLDER TEMPERATURES WILL BE
ACROSS THE HIGHER TERRAIN WHERE SOME CLOUDS COVER WILL LINGER.
RIDGING BUILDS IN AT SURFACE AND HEIGHTS WILL BE RISING ALOFT
MONDAY. HOWEVER...A STACKED LOW DEVELOPS OVER NORTHERN NEW ENGLAND
AND IT WILL MOVE LITTLE THROUGH TUESDAY. THIS WILL MAINTAIN A
NORTHWESTERLY FLOW OVER THE REGION.
DESPITE LOTS OF SUNSHINE MONDAY...THE FIRST FULL OF DAY OF FALL WILL
BE CHILLY. HIGHS ARE ONLY EXPECTED TO BE IN THE LOWER 50S TO LOWER
60S...AROUND 10 DEGREES BELOW NORMAL. IN ADDITION...WE WILL HAVE A
BRISK NORTHWESTERLY WINDS WHICH WILL MAKE IT FEEL EVEN COLDER.
CONDITIONS WILL BE MORE FAVORABLE FOR WIDESPREAD FROST MONDAY NIGHT
WITH MOSTLY CLEAR SKIES AND WINDS DIMINISHING LATE AT NIGHT. LOOKING
FOR LOWS IN THE 30S WITH THE COLDER TEMPERATURES ACROSS THE HIGHER
TERRAIN.
TEMPERATURES WILL MODERATE CLOSER TO SEASONABLE LEVELS TUESDAY...BUT
REMAIN BELOW NORMAL BY 5 TO 10 DEGREES. OUR REGION WILL BE
SANDWICHED BETWEEN THE RIDGE AXIS TO OUR WEST ACROSS THE OHIO VALLEY
AND GREAT LAKES REGION AND THE LARGE STACKED LOW WOBBLING OVER
NORTHERN NEW ENGLAND.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MUCH OF THE EXTENDED PERIOD WILL FEATURE QUIET WEATHER WITH
TEMPERATURES MODERATING ABOVE NORMAL.
AT THE START OF THE EXTENDED PERIOD...A CUTOFF UPPER LEVEL LOW OVER
ATLANTIC CANADA WILL BE DEPARTING OUT TO SEA...WHILE AN UPPER LEVEL
RIDGE WILL BE SITUATED OVER THE MIDWEST AND GREAT LAKES REGION. WITH
CLEAR SKIES AND LIGHT WINDS...TEMPS WILL BE COOL ON TUES NIGHT/WED
MORNING...WITH 30S TO LOW 40S OVER MUCH OF THE AREA. THERE MAY BE
SOME FROST ISSUES FOR THOSE AREAS WHERE THE GROWING SEASON IS STILL
ONGOING...SUCH AS THE CATSKILLS OR SOUTHERN VT.
A WEAK UPPER LEVEL DISTURBANCE WILL ATTEMPT TO MOVE AROUND THE UPPER
RIDGING OVER THE GREAT LAKES FOR WED AND THURS...AND THE MODELS SHOW
DIFFERENCES IN EXACTLY WHERE IT MOVES. THE 12Z ECMWF SHOWS THIS
FEATURE SLIDING UNDER THE RIDGE TOWARDS THE SOUTHEAST...WHILE THE
12Z GFS WEAKENS AND FLATTENS THE RIDGE ENOUGH TO MOVE THE
DISTURBANCE ACROSS THE NORTHEAST. WITH THIS FEATURE BEING RATHER
WEAK AND MOISTURE STARVED...EITHER SCENARIO WOULD KEEP OUR REGION
DRY. MAX TEMPS WILL BE IN THE UPPER 60S TO LOW 70S FOR VALLEY
AREAS...WHICH IS NEAR TO SLIGHTLY ABOVE NORMAL.
BEHIND THAT WEAK UPPER LEVEL DISTURBANCE...BOTH MODELS SHOWS STRONG
RIDGING REESTABLISHING ITSELF ALONG THE EASTERN SEABOARD FOR FRIDAY
INTO SATURDAY. UNDER PLENTY OF SUNSHINE AND CONTINUED DRY
CONDITIONS...THIS SHOULD ALLOW MAX TEMPS TO REACH INTO THE 70S
ACROSS MOST OF THE REGION...WITH MID 70S FOR THE CAPITAL REGION AND
MID HUDSON VALLEY.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
FLYING CONDITIONS ARE CURRENTLY VFR OR HIGH END MVFR WITH
INCREASING CLOUDS ACROSS THE REGION. A COLD FRONT WILL CURRENTLY
MOVING ACROSS WESTERN NEW YORK.
A BAND OF STEADY RAINFALL AHEAD OF THE BOUNDARY IS PROGRESSING
ACROSS CENTRAL NY AND WILL REACH THE HUDSON VALLEY AND WESTERN NEW
ENGLAND TAF SITES LATER THIS EVENING...PROBABLY BY AROUND 01Z-02Z.
FLYING CONDITIONS WILL QUICKLY DROP TO MVFR WITHIN THE RAIN
SHOWERS...AND SOME IFR CONDITIONS ARE EXPECTED WITHIN HEAVIER
BURSTS THROUGH ABOUT 05Z-06Z OR SO. AFTERWARD...SOME LINGERING SHOWERS ARE
EXPECTED THROUGH ABOUT SUNRISE...BUT IFR CONDITIONS LOOK TO
CONTINUE DUE TO LOW CIGS.
FLYING CONDITIONS SHOULD IMPROVE BACK TO VFR ON SUNDAY MORNING AS
THE SHOWERS END...AND CIGS BEGIN TO CLEAR OUT. VFR CONDITIONS ARE
EXPECTED THROUGH THE DAY SUNDAY.
SOUTHERLY WINDS OF AROUND 10 KTS AHEAD OF THE RAINFALL WILL BECOME
WESTERLY LATER TONIGHT AS THE COLD FRONT CROSSES THE REGION. THERE
MAY BE A FEW HIGHER GUSTS...ESP WITHIN THE HEAVIER BURSTS OF
RAINFALL. ON SUNDAY...WESTERLY WINDS WILL CONTINUE TO BE AROUND 10
KTS WITHIN DAYTIME MIXING...AND A FEW HIGHER GUSTS ARE POSSIBLE AT
KALB/KPSF.
OUTLOOK...
SUN NIGHT-MON NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. PATCHY FG
LATE NIGHT/EARLY MORNING.
TUE-THU: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
WIDESPREAD PRECIPITATION TONIGHT INTO SUNDAY AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
&&
.HYDROLOGY...
WIDESPREAD PRECIPITATION TONIGHT AS A COLD FRONT APPROACHES AND
CROSSES THE REGION. PRECIPITABLE WATERS VALUES ARE EXPECTED TO
INCREASE TO AROUND 1 1/2 INCHES AHEAD OF THE FRONTAL BOUNDARY WHICH
IS ABOUT 1 1/2 STANDARD DEVIATIONS ABOVE NORMAL. RAINFALL AMOUNTS OF
1 TO 1 1/2 INCHES ARE EXPECTED WITH LOCALLY HIGHER AMOUNTS OF 2 TO
POSSIBLY 3 INCHES. FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT
THIS TIME...HOWEVER WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE
ON MAJOR RIVERS. WHAT IS LIKELY IS PONDING OF WATER AND FLOODING OF
POOR DRAINAGE AND LOW LYING AREAS. CAN NOT RULE OUT ISOLATED FLASH
FLOODING.
THE UPPER LOW AND TROUGH AXIS WILL MOVE ACROSS THE REGION SUNDAY.
THE STEADY PRECIPITATION WILL TAPER OFF FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/FRUGIS
NEAR TERM...IAA/FRUGIS
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MIAMI FL
128 AM EDT FRI SEP 20 2013
.AVIATION...AN AREA OF SHOWERS WITH BRIEF MVFR CONDITIONS WILL AFFECT
AREAS NEAR KTMB OVER THE NEXT HOUR OR SO. OTHERWISE, VFR WILL
PREVAIL THROUGH THE TAF FCST PERIOD AS DRIER AIR ON A NE WIND
MOVES INTO SOUTH FL. THERE COULD BE A FEW SHOWERS OR TSTORMS,
MAINLY TOWARDS THE GULF COAST THIS AFTERNOON, BUT COVERAGE AND
CONFIDENCE IS LOW SO KEPT ANY MENTION OUR OF THE TAFS. NE WINDS
WILL PICK UP WITH GUSTS OF AROUND 15 KT THIS AFTERNOON. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 811 PM EDT THU SEP 19 2013/
UPDATE...
SCATTERED MODERATE RAIN SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS CONTINUE TO PUSH ONSHORE THE EAST COAST ALONG MAINLY
BROWARD AND PALM-BEACH COUNTIES THIS EVENING UNDER NORTHEAST FLOW.
SHORT TERM GUIDANCE GRADUALLY DISSIPATES THESE SHOWERS AS THEY
CONTINUE TO PUSH TO THE SOUTHWEST APPROACHING THE INTERIOR. MORE
ORGANIZED CONVECTION JUST NOW EXITING THE SOUTHERN MOST GULF
MARINE ZONE WILL CONTINUE TO PUSH SOUTH TOWARD THE FLORIDA KEYS.
KEPT POPS ON A GRADUAL DOWNWARD TREND ACROSS THE AREA THROUGH THE
NIGHT.
PREV DISCUSSION... /ISSUED 709 PM EDT THU SEP 19 2013/
AVIATION...
ISOLATED SHOWERS ARE EXPECTED TO MOSTLY DISSIPATE BY 0Z...SO RAIN-
FREE TAFS AT ALL SITES THROUGH 0Z SAT. ISOLATED SHOWERS POSSIBLE
ANYTIME...ESPECIALLY MIDDAY FRIDAY...BUT EXPECTED COVERAGE AND
CONFIDENCE IS FAR TO LOW TO WARRANT INCLUSION OF VCSH ATTM. VFR
CONDITIONS PREVAIL. NE WINDS 5-10 KTS OVERNIGHT WILL INCREASE TO
10-15 KTS ON FRIDAY.
PREV DISCUSSION... /ISSUED 227 PM EDT THU SEP 19 2013/
SHORT TERM (TONIGHT-SATURDAY NIGHT)...
THIS EVENING...THE LATEST RADAR SCAN SHOWED SCATTERED ACTIVITY
DEVELOPING OVER THE INTERIOR AREAS SPREADING WESTWARD TOWARD THE
GULF COAST. THE LATEST HRRR MODEL RUNS LINE UP WELL WITH THIS AND
INDICATE THIS ACTIVITY BECOMING FOCUSED OVER AND AROUND THE GULF
COAST AREAS THROUGH THE LATE AFTERNOON AND EVENING HOURS ONCE AGAIN.
CONSIDERING THE EXTENSIVE RAINFALL COVERAGE OVER THE GULF COAST
YESTERDAY...THE MAIN CONCERN THROUGH THIS EVENING WILL BE THE
POTENTIAL FOR ADDITIONAL HEAVY RAINFALL AND FLOODING DUE TO THE
SATURATED GROUNDS.
FRIDAY THROUGH SATURDAY NIGHT...THE LATEST NUMERICAL GUIDANCE
REMAINS IN DECENT AGREEMENT THROUGH THIS PERIOD AND SHOWS WHAT IS
LEFT OF THE WEAKENING BOUNDARY OR TROUGH CURRENTLY MOVING INTO
THE AREA CONTINUING SOUTH WITH SOME DRIER AIR FILLING IN BEHIND IT
FROM THE NORTH. THIS COMBINED WITH THE MEAN LOW-LEVEL FLOW UP TO
10 KFT SHIFTING TO THE NORTH WILL TRANSLATE TO LOWER RAINFALL
CHANCES EACH DAY. DEWPOINTS COULD REACH THE LOWER 60S ACROSS
PORTIONS OF THE INTERIOR AREAS SATURDAY AFTERNOON. MODEL SOUNDINGS
INDICATE PRECIPITABLE WATER VALUES DIPPING DOWN TO AROUND 1.3"
ACROSS PORTIONS OF THE AREA BY SATURDAY. TEMPERATURES ARE FORECAST
TO REMAIN AROUND NORMAL THROUGH THIS PERIOD...WITH THE EXCEPTION
BEING THE POSSIBILITY OF REACHING THE UPPER 60S ACROSS THE
NORTHERN INTERIOR AREAS BY DAYBREAK SATURDAY MORNING.
LONG TERM (SUNDAY-WEDNESDAY)...
AN UPPER TROUGH IS FORECAST TO DIG ACROSS THE SOUTHEAST AND
EASTERN SEABOARD THROUGH THE SECOND HALF OF THE WEEKEND. OUT AHEAD
OF THIS...SURFACE AND LOW LEVEL FLOW WILL SHIFT TO THE
SOUTH...BRINGING A SURGE OF MOISTURE BACK INTO SOUTH FLORIDA ON
SUNDAY. MODELS HAVE BEEN TRENDING TOWARDS A WEAKER LOW LEVEL/SURFACE
REFLECTION ACROSS THE SOUTHEAST...AND THUS A WEAKER COLD FRONT
MOVING INTO THE SOUTHEAST STATES. THE ECMWF IS NOW STRONGER THAN THE
GFS WITH THE BAROCLINIC SURFACE LOW ACROSS THE NORTHERN GULF
COAST/SOUTHEAST STATES...AND DRAWS THE MOISTURE FROM THE BAY OF
CAMPECHE SYSTEM TO THE NORTHEAST. REGARDLESS...SINCE THE MODELS HAVE
TRENDED SLOWER WITH THE COLD FRONT AND KEEP IT ACROSS NORTH FLORIDA
THROUGH EARLY NEXT WEEK...THE FOCUS FOR STORMS MAY BE ACROSS THE
GULF WATERS AND NORTH OR CENTRAL FLORIDA. WITH NO FOCUS FOR RAINFALL
ACROSS SOUTH FLORIDA AND EXTENSIVE CLOUD COVER POSSIBLY LIMITING
RAINFALL AMOUNTS DURING THE DAY MONDAY AND TUESDAY...THE HEAVIEST
RAINS MAY ACTUALLY FALL OVER THE NIGHT TIME HOURS AS SPEED/COASTAL
CONVERGENCE SETS UP. THE GFS AND ECMWF ARE HINTING AT THIS AS
WELL. SO RAINFALL CHANCES WILL LIKELY REMAIN HIGH SUNDAY THROUGH
TUESDAY. THE FORECAST IS UNCLEAR BEYOND THAT POINT...BUT RAINFALL
CHANCES WILL REMAIN ELEVATED THROUGH AT LEAST WEDNESDAY.
MARINE...
LIGHT TO MODERATE NORTHEAST WINDS WILL CONTINUE THROUGH SATURDAY AS
A WEAKENING FRONTAL BOUNDARY SHIFTS SOUTH INTO THE AREA. WINDS WILL
SHIFT TO THE SOUTH THROUGH THE SECOND HALF OF THE WEEKEND AND INTO
EARLY NEXT WEEK AS ANOTHER FRONTAL BOUNDARY APPROACHES FROM THE
NORTH. SEAS OVER THE ATLANTIC WATERS SHOULD BEGIN TO SUBSIDE OVER
THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 74 88 75 89 / 10 10 10 50
FORT LAUDERDALE 77 89 77 90 / 10 10 10 50
MIAMI 75 89 77 90 / 10 10 20 50
NAPLES 73 90 75 88 / 10 20 30 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1258 PM CDT FRI SEP 20 2013
.DISCUSSION...
1105 AM CDT
A SHORT WAVE TRACKED NORTHEASTWARD FROM WEST CENTRAL IL TO FAR
SOUTHWESTERN LOWER MI DURING THE LATE OVERNIGHT AND THE EARLY TO
MID MORNING HOURS. WHILE THE AXIS OF THE MAIN UPPER TROUGH IS
STILL UPSTREAM OVER THE UPPER MIDWEST...UPPER MS AND MID MO
VALLEYS...SUBSIDENCE AND DRYING IN THE MID LEVELS HAS RESULTED IN
AND END OF ANY SHOWERS...EXCEPT FOR A LINGERING SPRINKLE OR TWO
IN THE FAR SOUTHEASTERN PORTION OF THE FORECAST AREA.
A PRE-FRONTAL TROUGH ASSOCIATED WITH THE SHORT WAVE HAD ALREADY
VEERED WINDS TO WEST-SOUTH AND WESTERLY DURING THE FIRST PART OF
THE MORNING...WITH THE COLD FRONT AT LATE MORNING MOVING INTO
SOUTH CENTRAL WI AND NORTH CENTRAL IL AS WELL AS WEST CENTRAL IL.
BENEATH THE RAIN-ENDING MID LEVEL SUBSIDENCE THE LOW LEVEL
MOISTURE REMAINED HIGH WITH WIDESPREAD LOW...THICK STRATOCUMULUS
ACROSS THE AREA THOUGH THERE ARE SIGNS OF HOPE. AS THE COLD FRONT
CONTINUES TO PUSH FURTHER EASTWARD ACROSS FORECAST LATE THIS
MORNING AND THIS AFTERNOON IT WILL USHER IN DRIER LOW LEVEL AIR.
EXPECT TO SEE THE TREND IN SCATTERING OUT THE LOWER CLOUDS WEST TO
EAST TON CONTINUE AS THE AFTERNOON PROGRESSES ALTHOUGH THERE WILL
STILL BE A CIRRUS-STRATUS DECK OVER THE AREA AS THE UPPER TROUGH
IS PROGGED TO REMAIN WEST OF THE AREA...NOT MOVING OVER
SOUTHWESTERN WI AND NORTHWESTERN IL UNTIL MID TO LATE THIS
EVENING.
DO NOT FORESEE THE AREA OF STRATOCUMULUS SPREADING SOUTHEASTWARD
ACROSS NORTHERN IA AND WEST CENTRAL WI LATE THIS MORNING REACHING
THE LOCAL AREA UNTIL THIS EVENING GIVEN THE SLOW PROGRESSION OF
THE UPPER TROUGH AND HIGHER RESOLUTION MODEL RH FORECASTS IN THE
1-2.5K FT AGL LAYER KEEPING THIS AREA OF HIGHER LOW LEVEL
MOISTURE TO OUR NORTHWEST THROUGH THE REST OF THE DAY.
STRONG LOW LEVEL COLD AIR ADVECTION UNDERWAY AND WILL CONTINUE
TODAY AND TONIGHT. BASED ON UPSTREAM CONDITIONS HAVE DROPPED MAX
TEMPS FOR TODAY ACROSS THE FORECAST AREA A FEW DEGREES THOUGH A
BIT TRICKY AS IF CIRRUS THINS ENOUGH AFTER THE STRATOCUMULUS
CLEARS OUT THERE MAY BE A SLIGHT REBOUND IN THE WESTERN COUNTIES
UNTIL THE HEATING IS NEGATED BY THE COLD AIR ADVECTION.
TRS
//PREV DISCUSSION...
358 AM CDT
FORECAST CONCERNS ARE MAINLY FOCUSED ON THE NEAR TERM TODAY...AS A
COLD FRONT PUSHES STEADILY EAST ACROSS THE FORECAST AREA. SPOTTY
PRECIP WILL END WITH THE PASSAGE OF THE FRONT...WITH BREEZY...DRY AN
COOLER WEATHER ARRIVING AS WE HEAD INTO THE WEEKEND.
SURFACE LOW PRESSURE WAS CONSOLIDATING NORTH OF LAKE SUPERIOR EARLY
THIS MORNING...WITH A COLD FRONT TRAILING SOUTHWARD ACROSS WISCONSIN
AND INTO FAR EASTERN IOWA AT 08Z. RELATIVELY COMPLEX UPPER PATTERN
WAS EVIDENT FROM RADAR/WATER VAPOR IMAGERY...WITH SEVERAL SMALLER
SCALE CIRCULATIONS ROTATING THROUGH BASE OF UPPER TROUGH PROPAGATING
EAST ACROSS THE UPPER MIDWEST. AREA OF THUNDERSTORMS WHICH HAD MOVED
INTO THE FORECAST AREA LATE LAST HAD DECREASED IN COVERAGE IN THE
WAKE OF AN MCV NOTED LIFTING ACROSS SOUTHEAST WISCONSIN AND WITH
STABILIZATION OF THE NOCTURNAL BOUNDARY LAYER. A FEW SCATTERED
STORMS CONTINUED FROM NEAR KALAMAZOO MICHIGAN TO NEAR DANVILLE AND
ST LOUIS...WHERE SPC/RAP ANALYSIS INDICATES WESTERN PERIPHERY OF
1000-2000 J/KG MUCAPE AXIS. FARTHER WEST...AN AREA OF WEAKER
SHOWERS/LIGHT RAIN WAS NOTED ALONG THE LOW LEVEL FRONTAL BOUNDARY.
HIGH-RES GUIDANCE INDICATES THE CLUSTER OF SHOWERS AND THUNDERSTORMS
IN THE ST LOUIS/DOWNSTATE IL AREA WILL LIFT NORTHEAST THROUGH THIS
MORNING...AFFECTING MAINLY OUR SOUTHEAST COUNTIES. SCATTERED SHOWERS
ARE EXPECTED ELSEWHERE...ENDING WITH COLD FROPA LATER THIS MORNING
ACROSS NORTH CENTRAL ILLINOIS AND BY EARLY AFTERNOON ACROSS
NORTHEAST IL. FORECAST SOUNDINGS DEPICT SUBSTANTIAL DRYING
DEVELOPING IN THE 850-500 MB LAYER BEHIND THE COLD FRONT...WHICH IS
EVENTUALLY PROGGED TO CLEAR THE SOUTHEAST PART OF THE CWA VERY LATE
THIS AFTERNOON/EARLY THIS EVENING. NOT EXPECTING A LARGE TEMP SPREAD
DESPITE COLD FROPA ACROSS THE CWA TODAY...AS CLOUDS WILL HELP LIMIT
READINGS AHEAD OF THE FRONT.
UPPER TROUGH CONTINUES TO DEEPEN OVERHEAD AS IT MOVES SLOWLY EAST OF
THE AREA LATER TONIGHT AND SATURDAY. STRONG COOL ADVECTION DEVELOPS
AS WINDS SHIFT NORTH-NORTHWEST DURING THE PERIOD...WITH MODEL 850 MB
TEMPS FALLING TO AROUND +4C ON SATURDAY. THIS SHOULD LIMIT TEMPS
GENERALLY TO THE MID-UPPER 60S THROUGH THE WEEKEND DESPITE A GOOD
DEAL OF SUNSHINE...WITH SLIGHTLY COOLER TEMPS NEAR LAKE MICHIGAN
SUNDAY AS WINDS TURN ONSHORE FROM THE NORTHEAST. OVERNIGHT TEMPS
WILL COOL OFF CONSIDERABLY AS WELL...ESPECIALLY SUNDAY NIGHT AS THE
SURFACE HIGH PRESSURE RIDGE AXIS SPREADS INTO WISCONSIN AND ILLINOIS
AND ALLOWS FOR STRONG RADIATIONAL COOLING. HAVE UNDERCUT GUIDANCE IN
OUR TYPICALLY COOLER LOCATIONS SUNDAY MORNING...WITH SOME UPPER 30S
LIKELY WEST OF THE FOX RIVER VALLEY IN NORTH CENTRAL IL. COULD SEE
SOME LAKE EFFECT CLOUDS ACROSS NORTHEAST ILLINOIS/NORTHWEST INDIANA
SUNDAY MORNING AS LOW LEVEL WINDS BECOME NORTH-NORTHEAST.
LOOKS LIKE A DRY PERIOD WITH A MODERATION IN TEMPERATURES INTO NEXT
WEEK...AS HIGHLY AMPLIFIED UPPER PATTERN SLOWLY SHIFTS EAST. THIS
BRINGS UPPER RIDGE ACROSS THE AREA INTO MONDAY WITH THE SURFACE HIGH
DRIFTING OFF TO THE EAST. LONGER RANGE GUIDANCE INDICATES A SHORT
WAVE PUSHING INTO THE RIDGE ACROSS THE AREA TUESDAY...BUT WITH
LITTLE MOISTURE RETURN THANKS TO SOUTHEAST LOW LEVEL WINDS WEST OF
THE AFOREMENTIONED SURFACE HIGH. ECMWF/GFS BOTH SIMILAR IN
RE-BUILDING UPPER RIDGE ACROSS THE AREA IN THE WAKE OF THE SHORT
WAVE BY MID-WEEK. THIS WOULD SUPPORT TEMPS RISING BACK THROUGH THE
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS ARND 1000-1400FT AGL...SLOWLY LIFTING AFT 20Z.
* WEST WINDS ARND 10-14KT WITH GUSTS INCREASING TO 20KT AFT 20Z.
* WINDS SLOWLY TURNING NW/N AFT 23Z.
BEACHLER
//DISCUSSION...UPDATED 18Z...
FRONTAL BOUNDARY STRETCHES FROM GYY SOUTH THROUGH IKK AT 18Z.
WIND SHIFT TO THE WEST BEHIND THIS BNDRY. VISIBLE IMAGERY
CONTINUES TO INDICATE CONSIDERABLE CLOUDS WITH CIGS SLOW TO
IMPROVE...HOWEVER THEY HAVE COME UP TO ARND 1800-2000FT AGL. SKIES
ARE THINNING FURTHER BEHIND THE BOUNDARY...AND EXPECT THAT WITH
ADDTL HEATING THIS WILL ALLOW INCREASED WIND SPEEDS/GUSTS TO
20-24KT AND WILL HELP TO LIFT CIGS FURTHER. EXPECT CLOUDS TO
LINGER ARND 3-4KFT AGL THRU SUNSET THEN SLOWLY ERODE AFT 03Z. BY
08-10Z SKIES SHOULD ALMOST BECOME CLEAR WITH JUST A CIRRUS SHIELD
OVERHEAD. WINDS WILL CONTINUE TO TURN NORTH/NORTHWEST. AFT 16Z SAT
WINDS WILL BEGIN TO INCREASE YET AGAIN FROM THE NORTH/NORTHWEST
WITH GUSTS IN THE MID TO UPPER TEENS THRU MUCH OF MIDDAY AND
AFTERNOON HOURS. A SCT DECK OF CLOUDS SHOULD DEVELOP BY 18Z AND
MAY FOR A PERIOD OF TIME BECOME BKN EARLY IN THE AFTN. OTHERWISE
EXPECT IT TO REMAIN SCT WITH BASES ARND 3KFT AGL.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN MVFR CIGS THRU 20Z...MEDIUM CONFIDENCE IN
PRECISE TIMING OF IMPROVING CIGS.
* HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS.
* MEDIUM/HIGH CONFIDENCE IN TIMING OF WINDS TURNING NW/N.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
* SATURDAY NIGHT...MVFR CIGS POSSIBLE.
* SUNDAY THROUGH THURSDAY...DRY/VFR.
&&
.MARINE...
310 AM...LOW PRESSURE OVER ONTARIO WILL MOVE NORTHEAST TODAY AND
TONIGHT AS IT DEEPENS WITH A TRAILING COLD FRONT MOVING ACROSS
LAKE MICHIGAN LATER THIS MORNING...TURNING WINDS WESTERLY. AS
COLDER AIR SPREADS ACROSS THE REGION THIS EVENING...WINDS WILL
TURN NORTHWESTERLY AND INCREASE IN SPEED WITH A SHORT DURATION OF
30 KTS POSSIBLE. SPEEDS WILL RELAX BACK INTO THE 15-25KT RANGE
OVERNIGHT INTO SATURDAY MORNING AND THEN DIMINISH FURTHER SATURDAY
NIGHT INTO SUNDAY MORNING AS A LARGE RIDGE OF HIGH PRESSURE SLOWLY
PASSES ACROSS THE LAKES REGION SUNDAY AND SUNDAY NIGHT. THIS HIGH
IS EXPECTED TO REMAIN OVER NEW ENGLAND...MID ATLANTIC AND EASTERN
LAKES INTO THE MIDDLE OF NEXT WEEK...ALLOWING FOR SOUTHEAST TO
SOUTHERLY FLOW OVER THE LAKE FROM SUNDAY NIGHT THROUGH THURSDAY.
CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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
1251 PM CDT Fri Sep 20 2013
.DISCUSSION...
ISSUED 859 AM CDT Fri Sep 20 2013
14z/9am surface analysis shows cold front along the Illinois
River...with scattered light showers ahead of it across much of
the KILX CWA. Based on speed of front and current stability
parameters...think threat for thunder is over for the western half
of the area. Further east, HRRR suggests some re-development
across east-central and southeast Illinois during the afternoon.
Have made a quick update to the forecast to lower POPs and drop
thunder mention along and west of I-55. Will maintain likely POPs
for showers and thunderstorms further east, mainly along and east
of I-57. Zone update has already been sent.
&&
.AVIATION...
ISSUED 1251 PM CDT Fri Sep 20 2013
Line of showers is beginning to develop ahead of an advancing cold
front from near KTIP to KSPI. Based on radar timing tools, have
included a tempo group for showers between 18z and 20z at both
KDEC and KCMI. Once these showers pass east of the terminals, MVFR
ceilings will persist for a couple of hours before clouds
gradually begin to dissipate. Skies will become mostly clear by
early this evening, while low clouds associated with upper low
over northern/central Iowa track eastward and remain just north of
central Illinois. Winds will initially be from the W/SW ahead of
the front early this afternoon, then will become W/NW behind the
boundary later this afternoon through Saturday morning.
Barnes
&&
.PREV DISCUSSION...
ISSUED 322 AM CDT Fri Sep 20 2013
Deep upper trof moving across the Northern Plains and into the
Great Lake region...with the associated sfc low centered just
north of Lake Superior. Cold front draped through WI IA MO and
into the Southern Plains...lingering to the west along the Miss
River Valley this morning. Prefrontal showers and thunderstorms
from last night lingering in the east...weakened considerably in
the absence of an abundance of instability. First and main issue
for the forecast is the recharging of the atmosphere ahead of the
boundary in the warm sector this morning and the chances for
refire in the afternoon in the southeastern CWA. Beyond that,
Midwest gets into another dry period with heat building back into
the western CONUS and spreading into Central Illinois.
SHORT TERM...Today and tomorrow...
Scattered showers and thunderstorms throughout the day with the
best chances in the east this morning with remnant activity from
the overnight hours. Cold front still to the west will have the
chance to refire this afternoon. Exact location of the showers and
thunderstorms, as well as the strength, will be entirely dependent
on the speed of the advancing front, and any pockets of sunshine
that may enhance sfc based instability. At this point, however,
the front is moving through quickly and the precip may end up
wrapping up even sooner than midnight in the southeast. Cooler
temps tonight...somewhat inhibited by cloud cover anticipated.
Concern remains that more rapid clearing may result in a needed
adjustment. Tomorrow begins an extended dry period with sunny
skies and max temps in the lower 70s...light northerly winds as
high pressure begins to build back into the region.
LONG TERM...Sunday through Thursday...
Milder weather and dry through the extended. High pressure
dominates the eastern half of the country and temperatures remain
milder and closer to normal at first...with heat slowly building
again under a thermal ridge in the southwestern US. With
southwesterly flow kicking in next week Tues, the extended could
see some warmer temps as time draws nearer should the pattern
persist. Guidance is starting to respond and climb into the upper
70s/near 80 by mid week.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
907 AM CDT FRI SEP 20 2013
.DISCUSSION...
358 AM CDT
FORECAST CONCERNS ARE MAINLY FOCUSED ON THE NEAR TERM TODAY...AS A
COLD FRONT PUSHES STEADILY EAST ACROSS THE FORECAST AREA. SPOTTY
PRECIP WILL END WITH THE PASSAGE OF THE FRONT...WITH BREEZY...DRY AN
COOLER WEATHER ARRIVING AS WE HEAD INTO THE WEEKEND.
SURFACE LOW PRESSURE WAS CONSOLIDATING NORTH OF LAKE SUPERIOR EARLY
THIS MORNING...WITH A COLD FRONT TRAILING SOUTHWARD ACROSS WISCONSIN
AND INTO FAR EASTERN IOWA AT 08Z. RELATIVELY COMPLEX UPPER PATTERN
WAS EVIDENT FROM RADAR/WATER VAPOR IMAGERY...WITH SEVERAL SMALLER
SCALE CIRCULATIONS ROTATING THROUGH BASE OF UPPER TROUGH PROPAGATING
EAST ACROSS THE UPPER MIDWEST. AREA OF THUNDERSTORMS WHICH HAD MOVED
INTO THE FORECAST AREA LATE LAST HAD DECREASED IN COVERAGE IN THE
WAKE OF AN MCV NOTED LIFTING ACROSS SOUTHEAST WISCONSIN AND WITH
STABILIZATION OF THE NOCTURNAL BOUNDARY LAYER. A FEW SCATTERED
STORMS CONTINUED FROM NEAR KALAMAZOO MICHIGAN TO NEAR DANVILLE AND
ST LOUIS...WHERE SPC/RAP ANALYSIS INDICATES WESTERN PERIPHERY OF
1000-2000 J/KG MUCAPE AXIS. FARTHER WEST...AN AREA OF WEAKER
SHOWERS/LIGHT RAIN WAS NOTED ALONG THE LOW LEVEL FRONTAL BOUNDARY.
HIGH-RES GUIDANCE INDICATES THE CLUSTER OF SHOWERS AND THUNDERSTORMS
IN THE ST LOUIS/DOWNSTATE IL AREA WILL LIFT NORTHEAST THROUGH THIS
MORNING...AFFECTING MAINLY OUR SOUTHEAST COUNTIES. SCATTERED SHOWERS
ARE EXPECTED ELSEWHERE...ENDING WITH COLD FROPA LATER THIS MORNING
ACROSS NORTH CENTRAL ILLINOIS AND BY EARLY AFTERNOON ACROSS
NORTHEAST IL. FORECAST SOUNDINGS DEPICT SUBSTANTIAL DRYING
DEVELOPING IN THE 850-500 MB LAYER BEHIND THE COLD FRONT...WHICH IS
EVENTUALLY PROGGED TO CLEAR THE SOUTHEAST PART OF THE CWA VERY LATE
THIS AFTERNOON/EARLY THIS EVENING. NOT EXPECTING A LARGE TEMP SPREAD
DESPITE COLD FROPA ACROSS THE CWA TODAY...AS CLOUDS WILL HELP LIMIT
READINGS AHEAD OF THE FRONT.
UPPER TROUGH CONTINUES TO DEEPEN OVERHEAD AS IT MOVES SLOWLY EAST OF
THE AREA LATER TONIGHT AND SATURDAY. STRONG COOL ADVECTION DEVELOPS
AS WINDS SHIFT NORTH-NORTHWEST DURING THE PERIOD...WITH MODEL 850 MB
TEMPS FALLING TO AROUND +4C ON SATURDAY. THIS SHOULD LIMIT TEMPS
GENERALLY TO THE MID-UPPER 60S THROUGH THE WEEKEND DESPITE A GOOD
DEAL OF SUNSHINE...WITH SLIGHTLY COOLER TEMPS NEAR LAKE MICHIGAN
SUNDAY AS WINDS TURN ONSHORE FROM THE NORTHEAST. OVERNIGHT TEMPS
WILL COOL OFF CONSIDERABLY AS WELL...ESPECIALLY SUNDAY NIGHT AS THE
SURFACE HIGH PRESSURE RIDGE AXIS SPREADS INTO WISCONSIN AND ILLINOIS
AND ALLOWS FOR STRONG RADIATIONAL COOLING. HAVE UNDERCUT GUIDANCE IN
OUR TYPICALLY COOLER LOCATIONS SUNDAY MORNING...WITH SOME UPPER 30S
LIKELY WEST OF THE FOX RIVER VALLEY IN NORTH CENTRAL IL. COULD SEE
SOME LAKE EFFECT CLOUDS ACROSS NORTHEAST ILLINOIS/NORTHWEST INDIANA
SUNDAY MORNING AS LOW LEVEL WINDS BECOME NORTH-NORTHEAST.
LOOKS LIKE A DRY PERIOD WITH A MODERATION IN TEMPERATURES INTO NEXT
WEEK...AS HIGHLY AMPLIFIED UPPER PATTERN SLOWLY SHIFTS EAST. THIS
BRINGS UPPER RIDGE ACROSS THE AREA INTO MONDAY WITH THE SURFACE HIGH
DRIFTING OFF TO THE EAST. LONGER RANGE GUIDANCE INDICATES A SHORT
WAVE PUSHING INTO THE RIDGE ACROSS THE AREA TUESDAY...BUT WITH
LITTLE MOISTURE RETURN THANKS TO SOUTHEAST LOW LEVEL WINDS WEST OF
THE AFOREMENTIONED SURFACE HIGH. ECMWF/GFS BOTH SIMILAR IN
RE-BUILDING UPPER RIDGE ACROSS THE AREA IN THE WAKE OF THE SHORT
WAVE BY MID-WEEK. THIS WOULD SUPPORT TEMPS RISING BACK THROUGH THE
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* MVFR CIGS ARND 1000-1400FT AGL...SLOWLY LIFTING AFT 16Z.
* WEST WINDS ARND 10-14KT WITH GUSTS INCREASING TO 20KT AFT 16Z.
* WINDS SLOWLY TURNING NW/N AFT 23Z.
BEACHLER
//DISCUSSION...UPDATED 12Z...
LOW MVFR CIGS NOW WIDESPREAD ACROSS THE AREA WITH SOME PATCHY IFR
CIGS. CONTINUE TO EXPECT MAINLY LOW MVFR FOR PREVAILING CIGS BUT
SOME IFR CIGS OVER THE NEXT FEW HOURS WILL BE POSSIBLE. AS A COLD
FRONT MOVES ACROSS THE AREA LATER THIS MORNING...CIGS WILL LIFT
THROUGH MVFR AND SCATTER OUT BY LATE MORNING. ADDITIONAL SHOWER
DEVELOPMENT WILL BE POSSIBLE ALONG/AHEAD OF THIS FRONT THROUGH MID
MORNING BUT BULK OF THE PRECIP MAY END UP SOUTHEAST OF MDW
AFFECTING MAINLY GYY THROUGH LATE MORNING.
WEST SOUTHWEST WINDS AROUND 10KT WILL TURN MORE WESTERLY WITH THE
COLD FRONT AND BEGIN TO GUST BY LATE MORNING WITH GUSTS IN THE
18-20KT RANGE POSSIBLE THROUGH SUNSET. WINDS WILL TURN MORE
NORTHWEST THIS EVENING AS SPEEDS DIMINISH UNDER 10KTS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN MVFR CIGS THRU 16Z...MEDIUM CONFIDENCE IN
PRECISE TIMING OF IMPROVING CIGS.
* HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS.
* MEDIUM/HIGH CONFIDENCE IN TIMING OF WINDS TURNING NW/N.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
* SATURDAY NIGHT...MVFR CIGS POSSIBLE.
* SUNDAY THROUGH THURSDAY...DRY/VFR.
&&
.MARINE...
310 AM...LOW PRESSURE OVER ONTARIO WILL MOVE NORTHEAST TODAY AND
TONIGHT AS IT DEEPENS WITH A TRAILING COLD FRONT MOVING ACROSS
LAKE MICHIGAN LATER THIS MORNING...TURNING WINDS WESTERLY. AS
COLDER AIR SPREADS ACROSS THE REGION THIS EVENING...WINDS WILL
TURN NORTHWESTERLY AND INCREASE IN SPEED WITH A SHORT DURATION OF
30 KTS POSSIBLE. SPEEDS WILL RELAX BACK INTO THE 15-25KT RANGE
OVERNIGHT INTO SATURDAY MORNING AND THEN DIMINISH FURTHER SATURDAY
NIGHT INTO SUNDAY MORNING AS A LARGE RIDGE OF HIGH PRESSURE SLOWLY
PASSES ACROSS THE LAKES REGION SUNDAY AND SUNDAY NIGHT. THIS HIGH
IS EXPECTED TO REMAIN OVER NEW ENGLAND...MID ATLANTIC AND EASTERN
LAKES INTO THE MIDDLE OF NEXT WEEK...ALLOWING FOR SOUTHEAST TO
SOUTHERLY FLOW OVER THE LAKE FROM SUNDAY NIGHT THROUGH THURSDAY.
CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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
859 AM CDT Fri Sep 20 2013
.DISCUSSION...
ISSUED 859 AM CDT Fri Sep 20 2013
14z/9am surface analysis shows cold front along the Illinois
River...with scattered light showers ahead of it across much of
the KILX CWA. Based on speed of front and current stability
parameters...think threat for thunder is over for the western half
of the area. Further east, HRRR suggests some re-development
across east-central and southeast Illinois during the afternoon.
Have made a quick update to the forecast to lower POPs and drop
thunder mention along and west of I-55. Will maintain likely POPs
for showers and thunderstorms further east, mainly along and east
of I-57. Zone update has already been sent.
Barnes
&&
.AVIATION...
ISSUED 615 AM CDT Fri Sep 20 2013
Cold front just to our west will move across the TAF sites this
morning into early this afternoon with MVFR and local IFR cigs
in rain and fog. As the front progresses off to our east this
afternoon, conditions are expected to improve to VFR across
PIA and SPI first, and then over the remainder of the area by
20z. Surface winds this morning just ahead of the front will
be from a S-SW direction at 5 to 10 kts. Based on the current
movement of the front, it appears winds will switch into the
W-NW at PIA and SPI around 15z...and between 18z-20z over in CMI.
Rain chances will decrease from west to east starting later
this morning with DEC and CMI possibly seeing the rain linger
into late this morning into early this afternoon.
Smith
&&
.PREV DISCUSSION...
ISSUED 322 AM CDT Fri Sep 20 2013
Deep upper trof moving across the Northern Plains and into the
Great Lake region...with the associated sfc low centered just
north of Lake Superior. Cold front draped through WI IA MO and
into the Southern Plains...lingering to the west along the Miss
River Valley this morning. Prefrontal showers and thunderstorms
from last night lingering in the east...weakened considerably in
the absence of an abundance of instability. First and main issue
for the forecast is the recharging of the atmosphere ahead of the
boundary in the warm sector this morning and the chances for
refire in the afternoon in the southeastern CWA. Beyond that,
Midwest gets into another dry period with heat building back into
the western CONUS and spreading into Central Illinois.
SHORT TERM...Today and tomorrow...
Scattered showers and thunderstorms throughout the day with the
best chances in the east this morning with remnant activity from
the overnight hours. Cold front still to the west will have the
chance to refire this afternoon. Exact location of the showers and
thunderstorms, as well as the strength, will be entirely dependent
on the speed of the advancing front, and any pockets of sunshine
that may enhance sfc based instability. At this point, however,
the front is moving through quickly and the precip may end up
wrapping up even sooner than midnight in the southeast. Cooler
temps tonight...somewhat inhibited by cloud cover anticipated.
Concern remains that more rapid clearing may result in a needed
adjustment. Tomorrow begins an extended dry period with sunny
skies and max temps in the lower 70s...light northerly winds as
high pressure begins to build back into the region.
LONG TERM...Sunday through Thursday...
Milder weather and dry through the extended. High pressure
dominates the eastern half of the country and temperatures remain
milder and closer to normal at first...with heat slowly building
again under a thermal ridge in the southwestern US. With
southwesterly flow kicking in next week Tues, the extended could
see some warmer temps as time draws nearer should the pattern
persist. Guidance is starting to respond and climb into the upper
70s/near 80 by mid week.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
141 AM EDT FRI SEP 20 2013
.SYNOPSIS...
ISSUED AT 819 PM EDT THU SEP 19 2013
A WARM FRONTAL BOUNDARY MOVING THROUGH THE AREA TONIGHT COMBINED
WITH ADDITIONAL WEAK UPPER LEVEL DISTURBANCES WILL RESULT IN A
CONTINUED CHANCE OF THUNDERSTORMS THROUGH EARLY FRIDAY
MORNING...PARTICULARLY ACROSS NORTHWEST AND NORTH CENTRAL INDIANA
ALONG WITH SOUTHERN LOWER MICHIGAN. A STRONG UPPER LEVEL SYSTEM
WILL APPROACH THE GREAT LAKES REGION FRIDAY ALLOWING A COLD FRONT
TO MOVE INTO THE AREA. THIS WILL RESULT IN A LIKELIHOOD OF SHOWERS
AND THUNDERSTORMS FRIDAY AND FRIDAY NIGHT. DRY CONDITIONS WILL
RETURN FOR SATURDAY...WITH MUCH COOLER CONDITIONS BEHIND THE COLD
FRONT.
&&
.UPDATE...
ISSUED AT 819 PM EDT THU SEP 19 2013
EARLIER SCATTERED THUNDERSTORMS WHICH DEVELOPED IN VICINITY OF
SURFACE TROUGH/WARM FRONT FEATURE HAVE DIMINISHED OVER PAST FEW
HOURS AS LOW LEVEL CIN HAS INCREASED. RUC 00Z ANALYSIS STILL
DEPICTS AXIS OF 2000-2500 J/KG OF 100 HPA MLCAPES FROM EXTREME
WEST CENTRAL INDIANA INTO NORTHEAST ILLINOIS ALONG BROAD LOW LEVEL
CONFLUENCE ZONE. MORE ORGANIZED CONVECTIVE ACTIVITY REMAINS ACROSS
THE MID MS RIVER VALLEY AND APPROACHING THE WESTERN GREAT LAKES
WITH SEVERAL OUTFLOWS ASSOCIATED WITH THIS ACTIVITY. HAVE
MAINTAINED TREND OF INCREASING POPS TO MID TO HIGH CHANCE AGAIN
OVERNIGHT ACROSS THE NORTHWEST AS SMALLER SCALE PERTURBATIONS KICK
OUT OF CENTRAL CONUS TROUGH...WITH RESIDUAL OUTFLOW BOUNDARIES
PERHAPS PROVIDING SOME FOCUS. ONLY CHANGE TO PREVIOUS FORECAST WAS
TO MAKE SMALL ADJUSTMENTS IN LOWERING EVENING POPS FOLLOWING
OBSERVATIONAL TRENDS AND DECAY OF LATE AFTERNOON CONVECTION.
&&
.SHORT TERM...(LATE THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 347 PM EDT THU SEP 19 2013
MAIN FOCUS FOR THE REMAINDER OF THE AFTERNOON WILL BE ON BATCH OF
RAIN/THUNDER THAT WILL CONTINUE TO SINK SOUTHEAST THROUGH THE IWX
CWA. THIS ACTIVITY IS TIED TO A WEAK MCV NOW INTO WESTERN
MICHIGAN...WHICH HAS HELPED ENHANCE DEEP MOIST CONVERGENCE ALONG A
SFC WARM FRONT THAT HAS MIXED INTO OUR FAR SOUTHWESTERN CWA AS OF
19Z. THERE IS SOME CONCERN FOR AN ISOLATED STRONG/SEVERE CELL
ALONG THIS SFC FRONT SOUTH OF HWY 30 AND WEST OF HWY 15 IN INDIANA
GIVEN MORE PRONOUNCED LOW LEVEL CONVERGENCE AND MODERATE MLCAPE
VALUES HERE. MARGINAL DEEP LAYERED FLOW/SHEAR WILL KEEP THIS AN
ISOLATED WIND/HAIL THREAT. SMALL MBE VECTORS/TRAINING WITH PWAT
VALUES NEAR 1.80 INCHES MAY SUPPORT SOME ADDITIONAL LOCALIZED
FLOODING/HEAVY RAIN ACROSS MAINLY OUR INDIANA ZONES INTO THE LATE
AFTERNOON.
MCS SHOULD SETTLE SOUTH AND EAST OF THE LOCAL AREA THIS EVENING INTO
THE OVERNIGHT...LEAVING A WEAK LOW LEVEL BOUNDARY DRAPED OVER THE
AREA IN ITS WAKE. CHANCES FOR ISOLATED TO SCATTERED CONVECTION INVOF
THIS BOUNDARY APPEAR RATHER LOW THIS EVENING BUT INCREASE A BIT
LATER TONIGHT AS A SMALLER SCALE LEAD SHORTWAVE EJECTS OUT OF THE
CENTRAL HIGH PLAINS AND PROPAGATES INTO THE MISSOURI VALLEY AND
WESTERN GREAT LAKES. AFTERNOON WATER VAPOR ALSO SHOWS TROPICAL
MOISTURE FROM HURRICANE MANUAL BEING PICKED UP INTO THE SOUTHERN
PLAINS IN ADVANCE OF THIS FEATURE AND UPPER TROUGH. THIS SECONDARY
SHOT OF MOISTURE ADVECTION AND NARROW RIBBON OF CYCLONIC VORTICITY
MAY BE ENOUGH TO GENERATE ADDITIONAL SCATTERED CONVECTION BY
LATER TONIGHT...BEST CHANCES ACROSS NORTHWEST INDIANA AND SW LOWER
MICHIGAN.
AN UPPER LEVEL TROUGH ACROSS THE CANADIAN PRAIRIES AND NORTHERN HIGH
PLAINS WILL AMPLIFY EAST INTO THE UPPER MIDWEST AND MID MS VALLEY BY
TOMORROW. DEEPENING SFC REFLECTION IN AREA OF STRONGER CYCLONIC
VORTICITY ADVECTION DOWNSTREAM OF TROUGH AXIS WILL TRACK
NORTHEAST THROUGH THE NORTHERN GREAT LAKES AND ONTARIO. THIS WILL
FORCE A TRAILING COLD FRONT INTO OUR NORTHWESTERN ZONES FRIDAY
MORNING AND CENTRAL/EASTERN ZONES BY FRIDAY AFTERNOON. CHANCES FOR
SHOWERS/STORMS STILL LOOKING GOOD INVOF THE FRONT GIVEN 60-80
METER 500 MB HEIGHT FALLS OVER DEEP PRE-FRONTAL MOISTURE PLUME
(PWATS AT LEAST 1.75 INCHES AND 1000-850 MB MIXING RATIOS NEAR 14
G/KG). THERE COULD BE A LULL IN COVERAGE/INTENSITY OF SHOWERS IN
THE MORNING BEHIND THE AFOREMENTIONED LEAD WAVE...BUT EXPECT THIS
TO FILL BACK IN WITH SOME HEATING AS DEEPER TROPOSPHERIC ASCENT
PIVOTS IN. LOCALIZED HEAVY RAIN WILL CONTINUE TO BE A
CONCERN...ESPECIALLY IN AREAS THAT HAVE ALREADY SEEN HEAVY RAIN
TODAY. SPC HAS AREAS ALONG/EAST OF A KOKOMO-WARSAW-COLDWATER LINE
HIGHLIGHTED IN A SLIGHT RISK FOR SEVERE STORMS TOMORROW AFTERNOON.
STRONG FRONTAL SCALE FORCING COMBINED WITH THE POTENTIAL FOR WEAK
TO MODERATE BOUNDARY LAYER DESTABILIZATION MAY SUPPORT SOME
OVERACHIEVING UPDRAFTS...ALTHOUGH STRONGER FLOW/SHEAR NEEDED FOR
UPDRAFT/DOWNDRAFT SEPARATION AND ORGANIZATION WILL LIKELY LAG JUST
BEHIND THE FRONT. THUS...EXPECT LINGERING CLOUD COVER AND MARGINAL
SHEAR TO LIMIT THIS TO AN ISOLATED WIND/HAIL THREAT AT BEST.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 PM EDT THU SEP 19 2013
STRONG UPR LEVEL TROF OVER THE NRN PLAINS THIS AFTN WILL MOVE INTO
THE GRTLKS FRI NGT WHILE ACCOMPANYING CDFNT OUT AHEAD OF THE UPPER
FEATURE MOVES TO THE EAST OF THE CWA OVERNIGHT. MODELS IN GOOD
AGREEMENT THAT SHOWERS/TSTMS WILL BE ONGOING NEAR THE FRONT FRI EVE
SO BUMPED UP POPS IN THE EAST TO CATEGORICAL FOR THAT TIMEFRAME.
NAM/SREF A LITTLE QUICKER TO MOVE FRONT EAST OF THE CWA OVERNIGHT.
PREFER SLOWER GFS/ECMWF WHICH HAVE HAD BETTER RECENT RUN-RUN
CONTINUITY IN THIS REGARD... THUS MAINTAINED DIMINISHING RAIN
CHANCES OVERNIGHT WITH A SMALL CHC INTO EARLY SAT MORNING FAR EAST.
GFS/ECMWF SUGGESTING SOME POST-FRONTAL/LAKE ENHANCED SHOWERS PSBL
NWRN PORTION OF THE CWA SATURDAY AS UPR TROF SWINGS EAST THROUGH
LOWER MICHIGAN AND DELTA T`S INCREASE TO NEAR 13C. PREFER DRY
NAM/SREF SOLUTION IN OUR AREA AS AIRMASS IS FCST BY ALL MODELS TO BE
FAIRLY DRY... ESPECIALLY ALOFT... AND SUBSIDENCE INVERSION LEVEL
ONLY AROUND 5KFT. SFC HIGH FOLLOWING THE FRONT IS EXPECTED TO MOVE
ESE ACROSS THE UPR GRTLKS OVER THE REMAINDER OF THE WEEKEND
PROVIDING COOL/DRY WX. MODELS HAVE TRENDED A LITTLE MORE AMPLIFIED
WITH THE UPR FLOW AND ASSOCIATED LOW LEVEL CAA THIS WEEKEND... THUS
MADE MINOR DOWNWARD ADJUSTMENTS TO TEMPS WITH HIGHS FCST IN THE
L-M60S AND LOWS IN THE L-M40S.
UPR LEVEL RIDGE EXPECTED TO BUILD INTO THE GRTLKS REGION BY MONDAY
AND PERSIST THROUGH THURSDAY AS A SERIES OF SHRTWVS DIG SEWD FROM
THE NE PACIFIC INTO THE WRN U.S.. THIS SHOULD RESULT IN DRY WX
ACROSS OUR CWA THROUGH THIS PERIOD WITH TEMPS WARMING TO ABOVE
NORMAL READINGS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 140 AM EDT FRI SEP 20 2013
STRONG COLD FRONT WILL MOVE THROUGH THE AREA LATER TODAY.
ABUNDANT MOISTURE AND UPPER LEVEL DYNAMICS COUPLED WITH
CONVERGENCE ALONG FRONT SHOULD LEAD TO SHOWERS AND POSSIBLE
THUNDERSTORMS AT TAF SITES TODAY. MOIST AIR AND WEAK LIFT LEADING
TO SOME WIDELY SCATTERED LIGHT SHOWERS ON RADAR AT ISSUANCE. A FEW
OF THESE LIKELY TO MOVE THROUGH TAF SITES BUT CURRENT TRENDS
SUGGEST NO RESTRICTIONS. BETTER FORCING ARRIVES LATER THIS MORNING
AND LINGERS THROUGH AFTERNOON WHEN FRONT FINALLY PASSES. DRIER AIR
FILTERS IN TONIGHT. WRAP AROUND STRATOCUMULUS POSSIBLE AND KEPT
CIGS OPTIMISTIC AND VFR FOR TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...STEINWEDEL
LONG TERM...JT
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1255 PM CDT FRI SEP 20 2013
.UPDATE...
ISSUED AT 1250 PM CDT FRI SEP 20 2013
THE LOW CLOUDS HAVE ARRIVED IN THE CWFA AND SATELLITE TRENDS
INDICATE THEY SHOULD OVERSPREAD THE NORTHERN HALF OF THE CWFA
DURING THE AFTERNOON. CLOUD COVER WILL THUS HOLD TEMPERATURES DOWN
AND HIGHS HAVE BEEN LOWERED.
ISOLATED SPRINKLES ARE ALSO BEING REPORTED UNDER THE WRAP AROUND
CLOUDS SO THOSE WERE ADDED FOR THE AFTERNOON/EARLY EVENING HOURS.
CLEARING IS EXPECTED TO DEVELOP LATE THIS EVENING AND CONTINUE
OVERNIGHT WITH MAINLY CLEAR SKIES EXPECTED AROUND SUNRISE
SATURDAY. ..08..
UPDATE ISSUED AT 952 AM CDT FRI SEP 20 2013
CLOUD COVER IS PERSISTING LONGER THAN PREVIOUSLY THOUGHT. BASED ON
SATELLITE TRENDS...THICK HIGH CLOUDS SHOULD PERSIST FOR A MAJORITY
OF THE DAY. THE HIGH CLOUDS SHOULD SLOWLY THIN THIS AFTERNOON
ALLOWING MORE SUN TO BE SEEN. ..08..
&&
.SYNOPSIS...
ISSUED AT 327 AM CDT FRI SEP 20 2013
THE MAIN AREA OF SHOWERS AND THUNDERSTORMS HAS PUSHED TO EAST OF THE
DVN CWA THIS MORNING AHEAD OF THE PREFRONTAL TROUGH OVER EASTERN
IOWA AND THE COLD FRONT STRETCHES FROM CENTRAL LAKE SUPERIOR
SOUTHWARD THROUGH SOUTHEASTERN MINNESOTA AND CENTRAL IOWA AT THIS
TIME. SCATTERED SHOWERS AND LOW CEILINGS HAVE DEVELOPED ALONG THE
PREFRONTAL TROUGH THIS MORNING ASSOCIATED WITH THE CONVERGENCE ALONG
IT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT FRI SEP 20 2013
THE MAIN FORECASTS CONCERNS THIS MORNING WILL BE THE SCATTERED
SHOWERS ALONG THE PREFRONTAL TROUGH AND THE LOW CEILINGS.
THE MAIN AREA OF PRECIPITATION HAS MOVED INTO EASTERN ILLINOIS EARLY
THIS MORNING WITH A WEAK AREA OF SHOWERS AND LOW CEILINGS ALONG THE
PREFRONTAL TROUGH. THE 13 KM RAP HAD STRONG CONVERGENCE ALONG THIS
FEATURE EARLY THIS MORNING AND SHOWS THE CONVERGENCE WEAKENING
THROUGH 12 UTC AS BOUNDARY SHIFTS EASTWARD. THE THREAT OF SHOWERS
FROM THIS FEATURE SHOULD QUICKLY DIMINISH BY 12 UTC. THE COLD FRONT
WILL EXIT INTO CENTRAL ILLINOIS BY 15 UTC WITH STRONG COLD ADVECTION
USHERING IN MUCH COOLER AIR THAN WE HAVE EXPERIENCED OVER THE PAST
48 HOURS AND CLOSER TO NORMAL HIGH TEMPERATURES FOR MID SEPTEMBER.
CLOUDS WILL CLEAR QUICKLY THROUGH THE DAY ON FRIDAY AS DRIER AIR
MOVES INTO THE REGION. HOWEVER THERE IS SOME CONCERN THAT THE
STRATUS LAYER CURRENTLY OVER THE EASTERN DAKOTAS WILL MOVE
SOUTHEASTWARD AND INTO THE REGION FRIDAY NIGHT INTO SATURDAY
MORNING. MODELS CONTINUE TO SUGGEST THAT THE CLOUDS WILL DISSIPATE
SO WILL LEAVE THE FORECAST CLEAR OVERNIGHT. THIS PLAYS DIRECTLY INTO
THE TEMPERATURE FORECAST FOR SATURDAY MORNING AND HAVE NOT MADE ANY
CHANGES TO THE PREVIOUS FORECAST FOR LOW TEMPERATURES IN THE MID TO
UPPER 40S. IF STRATUS DOES MOVE INTO THE REGION LOW TEMPERATURES ON
SATURDAY MORNING MAY BE WARMER THAN CURRENTLY FORECAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 327 AM CDT FRI SEP 20 2013
NEARLY IDEAL OUTDOOR FALL WEATHER WILL GRACE THE EXTENDED FORECAST
EACH DAY. SURFACE HIGH PRESSURE OVER THE GREAT LAKES WILL DOMINATE
THE WEATHER THROUGH THE NEXT 4 DAYS...WITH A DRY FROPA
TUESDAY...FOLLOWED BY ANOTHER PLEASANT HIGH PRESSURE SYSTEM. THOSE
WITH HOPE FOR MORE RAIN WILL HAVE TO WAIT ON A SINGLE COLD FROPA
EVENT WHICH IS FORECAST BY THE GFS AND ECMWF TO OCCUR AROUND FRIDAY
NIGHT BEYOND OUR CURRENT DAY 7. THE TUESDAY TROF PASSAGE...SHOULD
BE MOISTURE STARVED...AND MAY ONLY BRIEFLY INCREASE HIGH LEVEL CLOUD
COVER.
LARGE DIURNAL SPREADS ARE FORECAST UNDER THE HIGH PRESSURE FOR
SATURDAY THROUGH MONDAY...WITH HIGHS IN THE MID 60S TO LOWER 70S AND
LOWS QUITE COOL...IN THE LOWER TO UPPER 40S IN GENERAL. THIS
TEMPERATURE RANGE REPRESENTS READINGS A FEW DEGREES BELOW CLIMATE
NORMALS...AND IS ONLY SIGNIFICANT IN COMPARISON TO OUR RECENT RECORD
WARMTH AND HUMIDITY. BEYOND MONDAY...MODEL BLENDS CONTINUE TO
INDICATE MODERATION...HOWEVER...I AM UNCERTAIN THAT THIS IS ACTUALLY
GOING TO OCCUR GIVEN OUR POTENTIAL FOR HAVING SOUTHEAST SURFACE FLOW
UNDER THE BUILDING UPPER RIDGE OF HIGH PRESSURE. THIS TRAJECTORY
COULD KEEP THE WIDE DIURNAL TEMPERATURE RANGES GOING...ALONG WITH
TEMPERATURES CLOSE TO NORMAL. WILL PASS THIS CONCERN ON THE THE NEXT
SHIFT WHICH SHOULD BE ABLE TO MORE FORMALLY PLACE THIS INTO THE
FORECAST BLEND.
ERVIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1250 PM CDT FRI SEP 20 2013
MVFR CIGS OF 2-3KFT AGL WILL OVERSPREAD AREAS ALONG AND NORTH OF
I-80 THROUGH 00Z/21. HIGH PRESSURE BUILDING INTO THE MIDWEST WILL
RESULT IN CLEARING SKIES FROM WEST TO EAST ACROSS EASTERN IOWA AND
NORTHERN ILLINOIS AFT 03Z/21. VFR CONDITIONS ARE EXPECTED DURING
THE DAY SATURDAY. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...DC
SHORT TERM...DC
LONG TERM...ERVIN
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
957 AM CDT FRI SEP 20 2013
.UPDATE...
ISSUED AT 952 AM CDT FRI SEP 20 2013
CLOUD COVER IS PERSISTING LONGER THAN PREVIOUSLY THOUGHT. BASED ON
SATELLITE TRENDS...THICK HIGH CLOUDS SHOULD PERSIST FOR A MAJORITY
OF THE DAY. THE HIGH CLOUDS SHOULD SLOWLY THIN THIS AFTERNOON
ALLOWING MORE SUN TO BE SEEN. ..08..
&&
.SYNOPSIS...
ISSUED AT 327 AM CDT FRI SEP 20 2013
THE MAIN AREA OF SHOWERS AND THUNDERSTORMS HAS PUSHED TO EAST OF THE
DVN CWA THIS MORNING AHEAD OF THE PREFRONTAL TROUGH OVER EASTERN
IOWA AND THE COLD FRONT STRETCHES FROM CENTRAL LAKE SUPERIOR
SOUTHWARD THROUGH SOUTHEASTERN MINNESOTA AND CENTRAL IOWA AT THIS
TIME. SCATTERED SHOWERS AND LOW CEILINGS HAVE DEVELOPED ALONG THE
PREFRONTAL TROUGH THIS MORNING ASSOCIATED WITH THE CONVERGENCE ALONG
IT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT FRI SEP 20 2013
THE MAIN FORECASTS CONCERNS THIS MORNING WILL BE THE SCATTERED
SHOWERS ALONG THE PREFRONTAL TROUGH AND THE LOW CEILINGS.
THE MAIN AREA OF PRECIPITATION HAS MOVED INTO EASTERN ILLINOIS EARLY
THIS MORNING WITH A WEAK AREA OF SHOWERS AND LOW CEILINGS ALONG THE
PREFRONTAL TROUGH. THE 13 KM RAP HAD STRONG CONVERGENCE ALONG THIS
FEATURE EARLY THIS MORNING AND SHOWS THE CONVERGENCE WEAKENING
THROUGH 12 UTC AS BOUNDARY SHIFTS EASTWARD. THE THREAT OF SHOWERS
FROM THIS FEATURE SHOULD QUICKLY DIMINISH BY 12 UTC. THE COLD FRONT
WILL EXIT INTO CENTRAL ILLINOIS BY 15 UTC WITH STRONG COLD ADVECTION
USHERING IN MUCH COOLER AIR THAN WE HAVE EXPERIENCED OVER THE PAST
48 HOURS AND CLOSER TO NORMAL HIGH TEMPERATURES FOR MID SEPTEMBER.
CLOUDS WILL CLEAR QUICKLY THROUGH THE DAY ON FRIDAY AS DRIER AIR
MOVES INTO THE REGION. HOWEVER THERE IS SOME CONCERN THAT THE
STRATUS LAYER CURRENTLY OVER THE EASTERN DAKOTAS WILL MOVE
SOUTHEASTWARD AND INTO THE REGION FRIDAY NIGHT INTO SATURDAY
MORNING. MODELS CONTINUE TO SUGGEST THAT THE CLOUDS WILL DISSIPATE
SO WILL LEAVE THE FORECAST CLEAR OVERNIGHT. THIS PLAYS DIRECTLY INTO
THE TEMPERATURE FORECAST FOR SATURDAY MORNING AND HAVE NOT MADE ANY
CHANGES TO THE PREVIOUS FORECAST FOR LOW TEMPERATURES IN THE MID TO
UPPER 40S. IF STRATUS DOES MOVE INTO THE REGION LOW TEMPERATURES ON
SATURDAY MORNING MAY BE WARMER THAN CURRENTLY FORECAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 327 AM CDT FRI SEP 20 2013
NEARLY IDEAL OUTDOOR FALL WEATHER WILL GRACE THE EXTENDED FORECAST
EACH DAY. SURFACE HIGH PRESSURE OVER THE GREAT LAKES WILL DOMINATE
THE WEATHER THROUGH THE NEXT 4 DAYS...WITH A DRY FROPA
TUESDAY...FOLLOWED BY ANOTHER PLEASANT HIGH PRESSURE SYSTEM. THOSE
WITH HOPE FOR MORE RAIN WILL HAVE TO WAIT ON A SINGLE COLD FROPA
EVENT WHICH IS FORECAST BY THE GFS AND ECMWF TO OCCUR AROUND FRIDAY
NIGHT BEYOND OUR CURRENT DAY 7. THE TUESDAY TROF PASSAGE...SHOULD
BE MOISTURE STARVED...AND MAY ONLY BRIEFLY INCREASE HIGH LEVEL CLOUD
COVER.
LARGE DIURNAL SPREADS ARE FORECAST UNDER THE HIGH PRESSURE FOR
SATURDAY THROUGH MONDAY...WITH HIGHS IN THE MID 60S TO LOWER 70S AND
LOWS QUITE COOL...IN THE LOWER TO UPPER 40S IN GENERAL. THIS
TEMPERATURE RANGE REPRESENTS READINGS A FEW DEGREES BELOW CLIMATE
NORMALS...AND IS ONLY SIGNIFICANT IN COMPARISON TO OUR RECENT RECORD
WARMTH AND HUMIDITY. BEYOND MONDAY...MODEL BLENDS CONTINUE TO
INDICATE MODERATION...HOWEVER...I AM UNCERTAIN THAT THIS IS ACTUALLY
GOING TO OCCUR GIVEN OUR POTENTIAL FOR HAVING SOUTHEAST SURFACE FLOW
UNDER THE BUILDING UPPER RIDGE OF HIGH PRESSURE. THIS TRAJECTORY
COULD KEEP THE WIDE DIURNAL TEMPERATURE RANGES GOING...ALONG WITH
TEMPERATURES CLOSE TO NORMAL. WILL PASS THIS CONCERN ON THE THE NEXT
SHIFT WHICH SHOULD BE ABLE TO MORE FORMALLY PLACE THIS INTO THE
FORECAST BLEND.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI SEP 20 2013
A STRONG COLD FRONT IS CROSSING THE MISSISSIPPI RIVER ATTM...AND
MOVING INTO WESTERN ILLINOIS. IFR TO MVFR CEILINGS ARE CURRENTLY
IN PLACE AT KBRL AND KMLI WITH VFR CEILINGS AT KCID AND KDBQ.
CEILINGS WILL SLOWLY LIFT AT KBRL AND KMLI AND BECOME VFR AROUND
15 UTC. CONDITIONS WILL REMAIN VFR THROUGH THE PERIOD AS DRY AIR
OVERSPREADS THE REGION. CONFIDENCE IS LOW THAT STRATUS CURRENTLY
ACROSS THE NORTHERN PLAINS WILL MOVE INTO THE REGION TOWARD THE END
OF THE TAF PERIOD. WEST TO NORTHWESTERLY WINDS WILL INCREASE
DURING THE MID MORNING HOURS WITH WINDS OF 10 TO 15 KNOTS GUSTING
TO 20 TO 22 KNOTS AT ALL TAF SITES. THE WINDS WILL SUBSIDE BY 00
UTC.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...DC
SHORT TERM...DC
LONG TERM...ERVIN
AVIATION...DC
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
646 AM CDT FRI SEP 20 2013
.SYNOPSIS...
ISSUED AT 327 AM CDT FRI SEP 20 2013
THE MAIN AREA OF SHOWERS AND THUNDERSTORMS HAS PUSHED TO EAST OF THE
DVN CWA THIS MORNING AHEAD OF THE PREFRONTAL TROUGH OVER EASTERN
IOWA AND THE COLD FRONT STRETCHES FROM CENTRAL LAKE SUPERIOR
SOUTHWARD THROUGH SOUTHEASTERN MINNESOTA AND CENTRAL IOWA AT THIS
TIME. SCATTERED SHOWERS AND LOW CEILINGS HAVE DEVELOPED ALONG THE
PREFRONTAL TROUGH THIS MORNING ASSOCIATED WITH THE CONVERGENCE ALONG
IT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT FRI SEP 20 2013
THE MAIN FORECASTS CONCERNS THIS MORNING WILL BE THE SCATTERED
SHOWERS ALONG THE PREFRONTAL TROUGH AND THE LOW CEILINGS.
THE MAIN AREA OF PRECIPITATION HAS MOVED INTO EASTERN ILLINOIS EARLY
THIS MORNING WITH A WEAK AREA OF SHOWERS AND LOW CEILINGS ALONG THE
PREFRONTAL TROUGH. THE 13 KM RAP HAD STRONG CONVERGENCE ALONG THIS
FEATURE EARLY THIS MORNING AND SHOWS THE CONVERGENCE WEAKENING
THROUGH 12 UTC AS BOUNDARY SHIFTS EASTWARD. THE THREAT OF SHOWERS
FROM THIS FEATURE SHOULD QUICKLY DIMINISH BY 12 UTC. THE COLD FRONT
WILL EXIT INTO CENTRAL ILLINOIS BY 15 UTC WITH STRONG COLD ADVECTION
USHERING IN MUCH COOLER AIR THAN WE HAVE EXPERIENCED OVER THE PAST
48 HOURS AND CLOSER TO NORMAL HIGH TEMPERATURES FOR MID SEPTEMBER.
CLOUDS WILL CLEAR QUICKLY THROUGH THE DAY ON FRIDAY AS DRIER AIR
MOVES INTO THE REGION. HOWEVER THERE IS SOME CONCERN THAT THE
STRATUS LAYER CURRENTLY OVER THE EASTERN DAKOTAS WILL MOVE
SOUTHEASTWARD AND INTO THE REGION FRIDAY NIGHT INTO SATURDAY
MORNING. MODELS CONTINUE TO SUGGEST THAT THE CLOUDS WILL DISSIPATE
SO WILL LEAVE THE FORECAST CLEAR OVERNIGHT. THIS PLAYS DIRECTLY INTO
THE TEMPERATURE FORECAST FOR SATURDAY MORNING AND HAVE NOT MADE ANY
CHANGES TO THE PREVIOUS FORECAST FOR LOW TEMPERATURES IN THE MID TO
UPPER 40S. IF STRATUS DOES MOVE INTO THE REGION LOW TEMPERATURES ON
SATURDAY MORNING MAY BE WARMER THAN CURRENTLY FORECAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 327 AM CDT FRI SEP 20 2013
NEARLY IDEAL OUTDOOR FALL WEATHER WILL GRACE THE EXTENDED FORECAST
EACH DAY. SURFACE HIGH PRESSURE OVER THE GREAT LAKES WILL DOMINATE
THE WEATHER THROUGH THE NEXT 4 DAYS...WITH A DRY FROPA
TUESDAY...FOLLOWED BY ANOTHER PLEASANT HIGH PRESSURE SYSTEM. THOSE
WITH HOPE FOR MORE RAIN WILL HAVE TO WAIT ON A SINGLE COLD FROPA
EVENT WHICH IS FORECAST BY THE GFS AND ECMWF TO OCCUR AROUND FRIDAY
NIGHT BEYOND OUR CURRENT DAY 7. THE TUESDAY TROF PASSAGE...SHOULD
BE MOISTURE STARVED...AND MAY ONLY BRIEFLY INCREASE HIGH LEVEL CLOUD
COVER.
LARGE DIURNAL SPREADS ARE FORECAST UNDER THE HIGH PRESSURE FOR
SATURDAY THROUGH MONDAY...WITH HIGHS IN THE MID 60S TO LOWER 70S AND
LOWS QUITE COOL...IN THE LOWER TO UPPER 40S IN GENERAL. THIS
TEMPERATURE RANGE REPRESENTS READINGS A FEW DEGREES BELOW CLIMATE
NORMALS...AND IS ONLY SIGNIFICANT IN COMPARISON TO OUR RECENT RECORD
WARMTH AND HUMIDITY. BEYOND MONDAY...MODEL BLENDS CONTINUE TO
INDICATE MODERATION...HOWEVER...I AM UNCERTAIN THAT THIS IS ACTUALLY
GOING TO OCCUR GIVEN OUR POTENTIAL FOR HAVING SOUTHEAST SURFACE FLOW
UNDER THE BUILDING UPPER RIDGE OF HIGH PRESSURE. THIS TRAJECTORY
COULD KEEP THE WIDE DIURNAL TEMPERATURE RANGES GOING...ALONG WITH
TEMPERATURES CLOSE TO NORMAL. WILL PASS THIS CONCERN ON THE THE NEXT
SHIFT WHICH SHOULD BE ABLE TO MORE FORMALLY PLACE THIS INTO THE
FORECAST BLEND.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 632 AM CDT FRI SEP 20 2013
A STRONG COLD FRONT IS CROSSING THE MISSISSIPPI RIVER ATTM...AND
MOVING INTO WESTERN ILLINOIS. IFR TO MVFR CEILINGS ARE CURRENTLY
IN PLACE AT KBRL AND KMLI WITH VFR CEILINGS AT KCID AND KDBQ.
CEILINGS WILL SLOWLY LIFT AT KBRL AND KMLI AND BECOME VFR AROUND
15 UTC. CONDITIONS WILL REMAIN VFR THROUGH THE PERIOD AS DRY AIR
OVERSPREADS THE REGION. CONFIDENCE IS LOW THAT STRATUS CURRENTLY
ACROSS THE NORTHERN PLAINS WILL MOVE INTO THE REGION TOWARD THE END
OF THE TAF PERIOD. WEST TO NORTHWESTERLY WINDS WILL INCREASE
DURING THE MID MORNING HOURS WITH WINDS OF 10 TO 15 KNOTS GUSTING
TO 20 TO 22 KNOTS AT ALL TAF SITES. THE WINDS WILL SUBSIDE BY 00
UTC.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...DC
SHORT TERM...DC
LONG TERM...ERVIN
AVIATION...DC
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
333 AM CDT FRI SEP 20 2013
.SYNOPSIS...
ISSUED AT 327 AM CDT FRI SEP 20 2013
THE MAIN AREA OF SHOWERS AND THUNDERSTORMS HAS PUSHED TO EAST OF THE
DVN CWA THIS MORNING AHEAD OF THE PREFRONTAL TROUGH OVER EASTERN
IOWA AND THE COLD FRONT STRETCHES FROM CENTRAL LAKE SUPERIOR
SOUTHWARD THROUGH SOUTHEASTERN MINNESOTA AND CENTRAL IOWA AT THIS
TIME. SCATTERED SHOWERS AND LOW CEILINGS HAVE DEVELOPED ALONG THE
PREFRONTAL TROUGH THIS MORNING ASSOCIATED WITH THE CONVERGENCE ALONG
IT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT FRI SEP 20 2013
THE MAIN FORECASTS CONCERNS THIS MORNING WILL BE THE SCATTERED
SHOWERS ALONG THE PREFRONTAL TROUGH AND THE LOW CEILINGS.
THE MAIN AREA OF PRECIPITATION HAS MOVED INTO EASTERN ILLINOIS EARLY
THIS MORNING WITH A WEAK AREA OF SHOWERS AND LOW CEILINGS ALONG THE
PREFRONTAL TROUGH. THE 13 KM RAP HAD STRONG CONVERGENCE ALONG THIS
FEATURE EARLY THIS MORNING AND SHOWS THE CONVERGENCE WEAKENING
THROUGH 12 UTC AS BOUNDARY SHIFTS EASTWARD. THE THREAT OF SHOWERS
FROM THIS FEATURE SHOULD QUICKLY DIMINISH BY 12 UTC. THE COLD FRONT
WILL EXIT INTO CENTRAL ILLINOIS BY 15 UTC WITH STRONG COLD ADVECTION
USHERING IN MUCH COOLER AIR THAN WE HAVE EXPERIENCED OVER THE PAST
48 HOURS AND CLOSER TO NORMAL HIGH TEMPERATURES FOR MID SEPTEMBER.
CLOUDS WILL CLEAR QUICKLY THROUGH THE DAY ON FRIDAY AS DRIER AIR
MOVES INTO THE REGION. HOWEVER THERE IS SOME CONCERN THAT THE
STRATUS LAYER CURRENTLY OVER THE EASTERN DAKOTAS WILL MOVE
SOUTHEASTWARD AND INTO THE REGION FRIDAY NIGHT INTO SATURDAY
MORNING. MODELS CONTINUE TO SUGGEST THAT THE CLOUDS WILL DISSIPATE
SO WILL LEAVE THE FORECAST CLEAR OVERNIGHT. THIS PLAYS DIRECTLY INTO
THE TEMPERATURE FORECAST FOR SATURDAY MORNING AND HAVE NOT MADE ANY
CHANGES TO THE PREVIOUS FORECAST FOR LOW TEMPERATURES IN THE MID TO
UPPER 40S. IF STRATUS DOES MOVE INTO THE REGION LOW TEMPERATURES ON
SATURDAY MORNING MAY BE WARMER THAN CURRENTLY FORECAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 327 AM CDT FRI SEP 20 2013
NEARLY IDEAL OUTDOOR FALL WEATHER WILL GRACE THE EXTENDED FORECAST
EACH DAY. SURFACE HIGH PRESSURE OVER THE GREAT LAKES WILL DOMINATE
THE WEATHER THROUGH THE NEXT 4 DAYS...WITH A DRY FROPA
TUESDAY...FOLLOWED BY ANOTHER PLEASANT HIGH PRESSURE SYSTEM. THOSE
WITH HOPE FOR MORE RAIN WILL HAVE TO WAIT ON A SINGLE COLD FROPA
EVENT WHICH IS FORECAST BY THE GFS AND ECMWF TO OCCUR AROUND FRIDAY
NIGHT BEYOND OUR CURRENT DAY 7. THE TUESDAY TROF PASSAGE...SHOULD
BE MOISTURE STARVED...AND MAY ONLY BRIEFLY INCREASE HIGH LEVEL CLOUD
COVER.
LARGE DIURNAL SPREADS ARE FORECAST UNDER THE HIGH PRESSURE FOR
SATURDAY THROUGH MONDAY...WITH HIGHS IN THE MID 60S TO LOWER 70S AND
LOWS QUITE COOL...IN THE LOWER TO UPPER 40S IN GENERAL. THIS
TEMPERATURE RANGE REPRESENTS READINGS A FEW DEGREES BELOW CLIMATE
NORMALS...AND IS ONLY SIGNIFICANT IN COMPARISON TO OUR RECENT RECORD
WARMTH AND HUMIDITY. BEYOND MONDAY...MODEL BLENDS CONTINUE TO
INDICATE MODERATION...HOWEVER...I AM UNCERTAIN THAT THIS IS ACTUALLY
GOING TO OCCUR GIVEN OUR POTENTIAL FOR HAVING SOUTHEAST SURFACE FLOW
UNDER THE BUILDING UPPER RIDGE OF HIGH PRESSURE. THIS TRAJECTORY
COULD KEEP THE WIDE DIURNAL TEMPERATURE RANGES GOING...ALONG WITH
TEMPERATURES CLOSE TO NORMAL. WILL PASS THIS CONCERN ON THE THE NEXT
SHIFT WHICH SHOULD BE ABLE TO MORE FORMALLY PLACE THIS INTO THE
FORECAST BLEND.
ERVIN
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1144 PM CDT THU SEP 19 2013
AN AREA OF LIGHT TO MODERATE RAIN WITH ISOLATED THUNDER ALONG AND
EAST OF THE MISSISSIPPI RIVER WILL GRADUALLY EXIT THE REGION EARLY
THIS MORNING. A COLD FRONT WILL MOVE THROUGH BEFORE SUNRISE. PATCHY MVFR
AND IFR CIGS WILL PRECEDE THE FRONT. BY 12Z THE FRONT WILL BE
EAST OF THE AREA WITH VFR CONDITIONS EXPECTED BEHIND THE FRONT.
POST FRONTAL NORTHWEST WINDS WILL GUST TO AROUND 20KTS DURING THE
LATE MORNING AND AFTERNOON.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...DC
SHORT TERM...DC
LONG TERM...ERVIN
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1127 AM MDT FRI SEP 20 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 323 AM MDT FRI SEP 20 2013
INITIAL FORECAST CONCERN WILL BE TEMPERATURES THROUGH THE WEEKEND
...WINDS THROUGH THE WEEKEND...ESPECIALLY ON SUNDAY...WITH THE LAST
PROBLEM THE NEXT CHANCE FOR PRECIPITATION AT THE BEGINNING OF NEXT
WEEK. SATELLITE SHOWING AN ACTIVE FLOW FROM THE PACIFIC INTO NORTH
AMERICA. OVER THE LAST 24 HOURS THE FLOW FROM THE CENTRAL PACIFIC
INTO NORTH AMERICA HAS AMPLIFIED. AT LOW LEVELS TWO DIFFERENT COLD
FRONTS HAVE BROUGHT IN A DRIER AND COOLER AIR MASS INTO THE AREA.
AT JET LEVEL...THE SREF FOLLOWED BY THE GFS WAS DOING THE BEST. AT
MID LEVELS...THE NAM WAS DOING A LITTLE BETTER THAN THE GFS...UKMET
AND CANADIAN. THE RUC FOLLOWED BY THE SREF AND THE NAM/ECMWF WAS
DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. THE GFS
FOLLOWED BY THE UKMET THEN SREF/NAM DID THE BEST ON THE LOW LEVEL
THERMAL FIELD.
TODAY/TONIGHT...WEAK SHOWERS AND THUNDERSTORMS HAVE POPPED NEAR THE
SOUTHERN AND WESTERN END OF THE FORECAST AREA. MODELS DO SHOW A RIGHT
REAR QUADRANT OF THE JET HANGING AROUND THROUGH THE MORNING AND IT
WILL BE ON TOP OF A WEAK MID LEVEL BAROCLINIC ZONE NEAR 700 MB.
WEAK FRONTOGENESIS IS IN THIS LAYER AS WELL WITH FAVORABLE THETA-E
LAPSE RATES. BASED ON LATEST TRENDS/MODEL DATA...WILL INCLUDE A
MENTION OF SPRINKLES...MOSTLY IN THE SOUTHERN HALF THROUGH MID
MORNING.
IN THE NORTHERN TIER OF COUNTIES...LACK OF CLOUD COVER HAS
ALLOWED TEMPERATURE/DEW POINT SPREADS TO BE VERY SMALL. HAVE ALREADY
SEEN PATCHY FOG IN SOME LOCATIONS. WHERE PRECIPITATION AND CLOUD
COVER ARE NOT EXPECTED...WILL PUT IN A MENTION OF PATCHY FOG ALSO
THROUGH MID MORNING. AT THIS TIME IT LOOKS LIKE CLOUD COVER WILL
DECREASE BY LATE MORNING. BASED ON TEMPERATURE BIASES AND CHANGE
OVER THE LAST 24 HOURS COMBINED WITH WHAT HAS BEEN DOING BEST ON
MAXES...MADE SOME ADJUSTMENTS UP FROM THE PREVIOUS FORECAST FOR THE
HIGH TEMPERATURES. MINS WILL BE WARMER TONIGHT DUE TO STRONGER
WINDS.
SATURDAY/SATURDAY NIGHT...MID/UPPER LEVEL RIDGE STARTS PUSHING TO
THE EAST WITH STRONG CROSS MOUNTAIN FLOW DEVELOPING. DURING THE LAST
HALF OF THE NIGHT THE MODELS SHOW THAT A LEFT FRONT QUADRANT
APPROACHES FROM THE SOUTH. THIS COULD SPREAD SOME HIGHER LEVEL CLOUDS
INTO THE AREA...ESPECIALLY IN THE SOUTHERN HALF. DUE TO A DRY AND
WELL MIXED AIR MASS...WILL KEEP THIS PERIOD DRY.
AS THE RESULT OF THE STRONG CROSS MOUNTAIN AND INCOMING UPPER
TROUGH MOVING INTO THE GREAT BASIN...LEE TROUGH WILL BEGIN TO
STRENGTHEN. INCREASING GRADIENT AND EXPECTED 3 HOUR PRESSURE FALLS
WOULD SUPPORT BREEZY SOUTHERLY WINDS DEVELOPING ACROSS THE AREA
DURING THE DAY. THERE WILL BE PLENTY OF SUN TO ALLOW HEATING AS 850
MB TEMPERATURES INCREASE 3 TO 5 DEGREES C FROM THE PREVIOUS DAY. SO
BASED ON THAT...RECENT BIASES...AND BETTER PERFORMING GUIDANCE...
RAISED THE MAXES ACCORDINGLY. LOW TEMPERATURES COULD STAY RATHER
MILD AS ATMOSPHERE STAYS WELL MIXED DUE TO STRENGTHENING LEE TROUGH.
SUNDAY/SUNDAY NIGHT...MODELS THEN START DIVERGING IN HOW THEY HANDLE
INCOMING UPPER TROUGH IN REGARDS TO SPEED AND AMPLITUDE. THIS
AFFECTS NUMEROUS PARAMETERS/FIELDS OF THE FORECAST. CURRENTLY THE
PATTERN OUT IN THE PACIFIC IS RATHER AMPLIFIED WITH A STRONG JET
STILL COMING DOWN THE WEST SIDE OF THE INCOMING UPPER TROUGH. THAT
WOULD SUPPORT HAVING A SLOWER AND MORE AMPLIFIED INCOMING UPPER
TROUGH. THIS PRETTY MUCH DISCOUNTS THE NAM AND THE SREF ARE VERY
FAST. MOST OF THE REMAINING OUTPUT IS CLOSE TO EACH OTHER ON THE
POSITION OF THE UPPER TROUGH AND RESULTING SURFACE PATTERN. GEFS
OUTPUT IS ALSO VERY SUPPORTIVE OF THE SLOWER SOLUTIONS WHICH ARE
THE GFS...ECMWF...UKMET AND CANADIAN.
SO WILL BASE FORECAST ON THOSE BUT CONFIDENCE IS A LITTLE BELOW
AVERAGE. MAIN SURFACE CONVERGENCE LIES NEAR THE WESTERN PORTION OF
THE FORECAST AREA ALONG WITH ACCOMPANYING MID/UPPER LIFT. CAP IS
ALSO THE WEAKEST THERE AS WELL. ALL THIS PLUS THE DETERMINISTIC QPF
AND GEFS PROBABILITY OF .05 SUPPORTS PULLING THE CHANCE OF
THUNDERSTORMS FURTHER WEST IN THE AFTERNOON. SO ADJUSTED THAT
ACCORDINGLY. AS STATED IN THE PREVIOUS FORECAST...MOISTURE COULD BE
THE LIMITING FACTOR ON COVERAGE AND SEVERITY. HOWEVER...LAPSE RATES
ARE VERY GOOD WITH VERY STRONG MID/UPPER LEVEL INDICATED...MAINLY
DURING THE EVENING. VERY STRONG PV ANOMALY ASSOCIATED WITH THIS
SYSTEM. PREVIOUS FORECAST HAS HIGH CHANCE IN THERE AND CONSIDERING
THE UNCERTAINTY BUT THE STRENGTH OF THE SYSTEM...FELT IT WAS
REASONABLE TO KEEP THOSE POPS.
VERY STRONG SYSTEM APPROACHING WILL CAUSE THE LEE TROUGH TO
STRENGTHEN EVEN MORE. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS
DEFINITELY SUPPORT WINDY/NEAR WIND ADVISORY CONDITIONS. SO INCREASED
WIND SPEEDS TO NEAR WIND ADVISORY. 850 MB TEMPERATURES SUPPORT
HAVING HIGH TEMPERATURES NEAR WHAT THE EXPECTED SATURDAY MAXES ARE.
SO ADJUSTED ACCORDINGLY.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 301 AM MDT FRI SEP 20 2013
EARLY MONDAY...ECMWF AND GFS PLACE THE UPPER LEVEL SHORTWAVE TROUGH
AXIS OVER NORTHEAST COLORADO WITH THE COLD FRONT BISECTING THE
FORECAST AREA. THE NAM IS THE MUCH FASTER OUTLIER AND PER WPC
MODEL DIAGNOSTICS DISCUSSION A BLEND OF THE GFS AND ECMWF IS
FAVORED FOR POSITION/TIMING. SHOWERS AND THUNDERSTORMS SHOULD BE
LIMITED TO THE EASTERN HALF OF THE FORECAST AREA MONDAY
MORNING...POSSIBLY THROUGH EARLY AFTERNOON DEPENDING ON TIMING.
AS THE SHORTWAVE TROUGH MOVES QUICKLY NORTHEAST...STRONG WESTERLY
MID/UPPER FLOW DEVELOPS OVER THE NORTHERN ROCKIES AND NORTHERN
PLAINS BY TUESDAY AND LEE SIDE TROUGH STRENGTHENS IN RESPONSE. VERY
SUBTLE UPPER LEVEL RIDGING MAY BE PRESENT ON TUESDAY BUT NOT ENOUGH
FOR TEMPERATURES TO SIGNIFICANTLY EXCEED NORMAL VALUES. A
SIGNIFICANT UPPER TROUGH WILL DEVELOP OVER THE WESTERN CONUS BY
WEDNESDAY. MODELS DISAGREE ON THE TIMING AND POSITION OF THIS
TROUGH...ALBEIT TO A LESSER EXTENT THAN PREVIOUS RUNS. GFS IS THE
QUICKEST AT EJECTING IT NORTHEASTWARD. EVEN SO...GFS ENSEMBLE MEAN
QPF REMAINS NORTH AND NORTHWEST OF THE FORECAST AREA THROUGH THE END
OF THE EXTENDED PERIOD...SO THE FORECAST REMAINS DRY BEYOND MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1121 AM MDT FRI SEP 20 2013
VFR CONDITIONS FORECAST FOR THE 18Z TAFS. LIGHT SOUTHERLY WINDS
WILL CONTINUE THROUGH THE PERIOD. POINT SOUNDING FOR KGLD SHOWS
A POSSIBILITY OF LOW CLOUDS/FOG...BUT AM NOT CONFIDENT ENOUGH AT
THIS TIME TO PLACE A MENTION OF IT IN THE TAF GIVEN HOW BRIEF THE
LOW LEVELS SATURATE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...BRB
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
522 AM MDT FRI SEP 20 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 323 AM MDT FRI SEP 20 2013
INITIAL FORECAST CONCERN WILL BE TEMPERATURES THROUGH THE WEEKEND
...WINDS THROUGH THE WEEKEND...ESPECIALLY ON SUNDAY...WITH THE LAST
PROBLEM THE NEXT CHANCE FOR PRECIPITATION AT THE BEGINNING OF NEXT
WEEK. SATELLITE SHOWING AN ACTIVE FLOW FROM THE PACIFIC INTO NORTH
AMERICA. OVER THE LAST 24 HOURS THE FLOW FROM THE CENTRAL PACIFIC
INTO NORTH AMERICA HAS AMPLIFIED. AT LOW LEVELS TWO DIFFERENT COLD
FRONTS HAVE BROUGHT IN A DRIER AND COOLER AIR MASS INTO THE AREA.
AT JET LEVEL...THE SREF FOLLOWED BY THE GFS WAS DOING THE BEST. AT
MID LEVELS...THE NAM WAS DOING A LITTLE BETTER THAN THE GFS...UKMET
AND CANADIAN. THE RUC FOLLOWED BY THE SREF AND THE NAM/ECMWF WAS
DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. THE GFS
FOLLOWED BY THE UKMET THEN SREF/NAM DID THE BEST ON THE LOW LEVEL
THERMAL FIELD.
TODAY/TONIGHT...WEAK SHOWERS AND THUNDERSTORMS HAVE POPPED NEAR THE
SOUTHERN AND WESTERN END OF THE FORECAST AREA. MODELS DO SHOW A RIGHT
REAR QUADRANT OF THE JET HANGING AROUND THROUGH THE MORNING AND IT
WILL BE ON TOP OF A WEAK MID LEVEL BAROCLINIC ZONE NEAR 700 MB.
WEAK FRONTOGENESIS IS IN THIS LAYER AS WELL WITH FAVORABLE THETA-E
LAPSE RATES. BASED ON LATEST TRENDS/MODEL DATA...WILL INCLUDE A
MENTION OF SPRINKLES...MOSTLY IN THE SOUTHERN HALF THROUGH MID
MORNING.
IN THE NORTHERN TIER OF COUNTIES...LACK OF CLOUD COVER HAS
ALLOWED TEMPERATURE/DEWPOINT SPREADS TO BE VERY SMALL. HAVE ALREADY
SEEN PATCHY FOG IN SOME LOCATIONS. WHERE PRECIPITATION AND CLOUD
COVER ARE NOT EXPECTED...WILL PUT IN A MENTION OF PATCHY FOG ALSO
THROUGH MID MORNING. AT THIS TIME IT LOOKS LIKE CLOUD COVER WILL
DECREASE BY LATE MORNING. BASED ON TEMPERATURE BIASES AND CHANGE
OVER THE LAST 24 HOURS COMBINED WITH WHAT HAS BEEN DOING BEST ON
MAXES...MADE SOME ADJUSTMENTS UP FROM THE PREVIOUS FORECAST FOR THE
HIGH TEMPERATURES. MINS WILL BE WARMER TONIGHT DUE TO STRONGER
WINDS.
SATURDAY/SATURDAY NIGHT...MID/UPPER LEVEL RIDGE STARTS PUSHING TO
THE EAST WITH STRONG CROSS MOUNTAIN FLOW DEVELOPING. DURING THE LAST
HALF OF THE NIGHT THE MODELS SHOW THAT A LEFT FRONT QUADRANT
APPROACHES FROM THE SOUTH. THIS COULD SPREAD SOME HIGHER LEVEL CLOUDS
INTO THE AREA...ESPECIALLY IN THE SOUTHERN HALF. DUE TO A DRY AND
WELL MIXED AIR MASS...WILL KEEP THIS PERIOD DRY.
AS THE RESULT OF THE STRONG CROSS MOUNTAIN AND INCOMING UPPER
TROUGH MOVING INTO THE GREAT BASIN...LEE TROUGH WILL BEGIN TO
STRENGTHEN. INCREASING GRADIENT AND EXPECTED 3 HOUR PRESSURE FALLS
WOULD SUPPORT BREEZY SOUTHERLY WINDS DEVELOPING ACROSS THE AREA
DURING THE DAY. THERE WILL BE PLENTY OF SUN TO ALLOW HEATING AS 850
MB TEMPERATURES INCREASE 3 TO 5 DEGREES C FROM THE PREVIOUS DAY. SO
BASED ON THAT...RECENT BIASES...AND BETTER PERFORMING GUIDANCE...
RAISED THE MAXES ACCORDINGLY. LOW TEMPERATURES COULD STAY RATHER
MILD AS ATMOSPHERE STAYS WELL MIXED DUE TO STRENGTHENING LEE TROUGH.
SUNDAY/SUNDAY NIGHT...MODELS THEN START DIVERGING IN HOW THEY HANDLE
INCOMING UPPER TROUGH IN REGARDS TO SPEED AND AMPLITUDE. THIS
AFFECTS NUMEROUS PARAMETERS/FIELDS OF THE FORECAST. CURRENTLY THE
PATTERN OUT IN THE PACIFIC IS RATHER AMPLIFIED WITH A STRONG JET
STILL COMING DOWN THE WEST SIDE OF THE INCOMING UPPER TROUGH. THAT
WOULD SUPPORT HAVING A SLOWER AND MORE AMPLIFIED INCOMING UPPER
TROUGH. THIS PRETTY MUCH DISCOUNTS THE NAM AND THE SREF ARE VERY
FAST. MOST OF THE REMAINING OUTPUT IS CLOSE TO EACH OTHER ON THE
POSITION OF THE UPPER TROUGH AND RESULTING SURFACE PATTERN. GEFS
OUTPUT IS ALSO VERY SUPPORTIVE OF THE SLOWER SOLUTIONS WHICH ARE
THE GFS...ECMWF...UKMET AND CANADIAN.
SO WILL BASE FORECAST ON THOSE BUT CONFIDENCE IS A LITTLE BELOW
AVERAGE. MAIN SURFACE CONVERGENCE LIES NEAR THE WESTERN PORTION OF
THE FORECAST AREA ALONG WITH ACCOMPANYING MID/UPPER LIFT. CAP IS
ALSO THE WEAKEST THERE AS WELL. ALL THIS PLUS THE DETERMINISTIC QPF
AND GEFS PROBABILITY OF .05 SUPPORTS PULLING THE CHANCE OF
THUNDERSTORMS FURTHER WEST IN THE AFTERNOON. SO ADJUSTED THAT
ACCORDINGLY. AS STATED IN THE PREVIOUS FORECAST...MOISTURE COULD BE
THE LIMITING FACTOR ON COVERAGE AND SEVERITY. HOWEVER...LAPSE RATES
ARE VERY GOOD WITH VERY STRONG MID/UPPER LEVEL INDICATED...MAINLY
DURING THE EVENING. VERY STRONG PV ANOMALY ASSOCIATED WITH THIS
SYSTEM. PREVIOUS FORECAST HAS HIGH CHANCE IN THERE AND CONSIDERING
THE UNCERTAINTY BUT THE STRENGTH OF THE SYSTEM...FELT IT WAS
REASONABLE TO KEEP THOSE POPS.
VERY STRONG SYSTEM APPROACHING WILL CAUSE THE LEE TROUGH TO
STRENGTHEN EVEN MORE. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS
DEFINITELY SUPPORT WINDY/NEAR WIND ADVISORY CONDITIONS. SO INCREASED
WIND SPEEDS TO NEAR WIND ADVISORY. 850 MB TEMPERATURES SUPPORT
HAVING HIGH TEMPERATURES NEAR WHAT THE EXPECTED SATURDAY MAXES ARE.
SO ADJUSTED ACCORDINGLY.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 301 AM MDT FRI SEP 20 2013
EARLY MONDAY...ECMWF AND GFS PLACE THE UPPER LEVEL SHORTWAVE TROUGH
AXIS OVER NORTHEAST COLORADO WITH THE COLD FRONT BISECTING THE
FORECAST AREA. THE NAM IS THE MUCH FASTER OUTLIER AND PER WPC
MODEL DIAGNOSTICS DISCUSSION A BLEND OF THE GFS AND ECMWF IS
FAVORED FOR POSITION/TIMING. SHOWERS AND THUNDERSTORMS SHOULD BE
LIMITED TO THE EASTERN HALF OF THE FORECAST AREA MONDAY
MORNING...POSSIBLY THROUGH EARLY AFTERNOON DEPENDING ON TIMING.
AS THE SHORTWAVE TROUGH MOVES QUICKLY NORTHEAST...STRONG WESTERLY
MID/UPPER FLOW DEVELOPS OVER THE NORTHERN ROCKIES AND NORTHERN
PLAINS BY TUESDAY AND LEE SIDE TROUGH STRENGTHENS IN RESPONSE. VERY
SUBTLE UPPER LEVEL RIDGING MAY BE PRESENT ON TUESDAY BUT NOT ENOUGH
FOR TEMPERATURES TO SIGNIFICANTLY EXCEED NORMAL VALUES. A
SIGNIFICANT UPPER TROUGH WILL DEVELOP OVER THE WESTERN CONUS BY
WEDNESDAY. MODELS DISAGREE ON THE TIMING AND POSITION OF THIS
TROUGH...ALBEIT TO A LESSER EXTENT THAN PREVIOUS RUNS. GFS IS THE
QUICKEST AT EJECTING IT NORTHEASTWARD. EVEN SO...GFS ENSEMBLE MEAN
QPF REMAINS NORTH AND NORTHWEST OF THE FORECAST AREA THROUGH THE END
OF THE EXTENDED PERIOD...SO THE FORECAST REMAINS DRY BEYOND MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 522 AM MDT FRI SEP 20 2013
VERY LIGHT WINDS AND SMALL TEMPERATURE DEW POINT DEPRESSION AT
MCK COULD RESULT IN FOG REDUCTING VISIBILITY BRIEFLY BETWEEN 12Z
AND 14Z. IF THIS OCCURS IT WILL BE BRIEF AND LIKELY REMAIN WITHIN
VFR CATEGORY. VFR CONDITIONS ARE EXPECTED TO CONTINUE AT BOTH GLD
AND MCK FOR THE NEXT 24 HOURS. WINDS WILL BE LIGHT AND VARIABLE
EARLY AND STRENGTHEN TO AROUND 5 TO 10 KNOTS LATER THIS AFTERNOON
AS A SURFACE HIGH MOVES EAST OF THE AREA. THE NAM MODEL IS MORE
MOIST THAN OTHERS AT THE TOP OF THE MIXED LAYER THIS
AFTERNOON...AND THIS COULD RESULT IN FEW/SCATTERED CUMULUS
DEVELOPING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...BRB
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
323 AM MDT FRI SEP 20 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 323 AM MDT FRI SEP 20 2013
INITIAL FORECAST CONCERN WILL BE TEMPERATURES THROUGH THE WEEKEND
...WINDS THROUGH THE WEEKEND...ESPECIALLY ON SUNDAY...WITH THE LAST
PROBLEM THE NEXT CHANCE FOR PRECIPITATION AT THE BEGINNING OF NEXT
WEEK. SATELLITE SHOWING AN ACTIVE FLOW FROM THE PACIFIC INTO NORTH
AMERICA. OVER THE LAST 24 HOURS THE FLOW FROM THE CENTRAL PACIFIC
INTO NORTH AMERICA HAS AMPLIFIED. AT LOW LEVELS TWO DIFFERENT COLD
FRONTS HAVE BROUGHT IN A DRIER AND COOLER AIR MASS INTO THE AREA.
AT JET LEVEL...THE SREF FOLLOWED BY THE GFS WAS DOING THE BEST. AT
MID LEVELS...THE NAM WAS DOING A LITTLE BETTER THAN THE GFS...UKMET
AND CANADIAN. THE RUC FOLLOWED BY THE SREF AND THE NAM/ECMWF WAS
DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. THE GFS
FOLLOWED BY THE UKMET THEN SREF/NAM DID THE BEST ON THE LOW LEVEL
THERMAL FIELD.
TODAY/TONIGHT...WEAK SHOWERS AND THUNDERSTORMS HAVE POPPED NEAR THE
SOUTHERN AND WESTERN END OF THE FORECAST AREA. MODELS DO SHOW A RIGHT
REAR QUADRANT OF THE JET HANGING AROUND THROUGH THE MORNING AND IT
WILL BE ON TOP OF A WEAK MID LEVEL BAROCLINIC ZONE NEAR 700 MB.
WEAK FRONTOGENESIS IS IN THIS LAYER AS WELL WITH FAVORABLE THETA-E
LAPSE RATES. BASED ON LATEST TRENDS/MODEL DATA...WILL INCLUDE A
MENTION OF SPRINKLES...MOSTLY IN THE SOUTHERN HALF THROUGH MID
MORNING.
IN THE NORTHERN TIER OF COUNTIES...LACK OF CLOUD COVER HAS
ALLOWED TEMPERATURE/DEWPOINT SPREADS TO BE VERY SMALL. HAVE ALREADY
SEEN PATCHY FOG IN SOME LOCATIONS. WHERE PRECIPITATION AND CLOUD
COVER ARE NOT EXPECTED...WILL PUT IN A MENTION OF PATCHY FOG ALSO
THROUGH MID MORNING. AT THIS TIME IT LOOKS LIKE CLOUD COVER WILL
DECREASE BY LATE MORNING. BASED ON TEMPERATURE BIASES AND CHANGE
OVER THE LAST 24 HOURS COMBINED WITH WHAT HAS BEEN DOING BEST ON
MAXES...MADE SOME ADJUSTMENTS UP FROM THE PREVIOUS FORECAST FOR THE
HIGH TEMPERATURES. MINS WILL BE WARMER TONIGHT DUE TO STRONGER
WINDS.
SATURDAY/SATURDAY NIGHT...MID/UPPER LEVEL RIDGE STARTS PUSHING TO
THE EAST WITH STRONG CROSS MOUNTAIN FLOW DEVELOPING. DURING THE LAST
HALF OF THE NIGHT THE MODELS SHOW THAT A LEFT FRONT QUADRANT
APPROACHES FROM THE SOUTH. THIS COULD SPREAD SOME HIGHER LEVEL CLOUDS
INTO THE AREA...ESPECIALLY IN THE SOUTHERN HALF. DUE TO A DRY AND
WELL MIXED AIR MASS...WILL KEEP THIS PERIOD DRY.
AS THE RESULT OF THE STRONG CROSS MOUNTAIN AND INCOMING UPPER
TROUGH MOVING INTO THE GREAT BASIN...LEE TROUGH WILL BEGIN TO
STRENGTHEN. INCREASING GRADIENT AND EXPECTED 3 HOUR PRESSURE FALLS
WOULD SUPPORT BREEZY SOUTHERLY WINDS DEVELOPING ACROSS THE AREA
DURING THE DAY. THERE WILL BE PLENTY OF SUN TO ALLOW HEATING AS 850
MB TEMPERATURES INCREASE 3 TO 5 DEGREES C FROM THE PREVIOUS DAY. SO
BASED ON THAT...RECENT BIASES...AND BETTER PERFORMING GUIDANCE...
RAISED THE MAXES ACCORDINGLY. LOW TEMPERATURES COULD STAY RATHER
MILD AS ATMOSPHERE STAYS WELL MIXED DUE TO STRENGTHENING LEE TROUGH.
SUNDAY/SUNDAY NIGHT...MODELS THEN START DIVERGING IN HOW THEY HANDLE
INCOMING UPPER TROUGH IN REGARDS TO SPEED AND AMPLITUDE. THIS
AFFECTS NUMEROUS PARAMETERS/FIELDS OF THE FORECAST. CURRENTLY THE
PATTERN OUT IN THE PACIFIC IS RATHER AMPLIFIED WITH A STRONG JET
STILL COMING DOWN THE WEST SIDE OF THE INCOMING UPPER TROUGH. THAT
WOULD SUPPORT HAVING A SLOWER AND MORE AMPLIFIED INCOMING UPPER
TROUGH. THIS PRETTY MUCH DISCOUNTS THE NAM AND THE SREF ARE VERY
FAST. MOST OF THE REMAINING OUTPUT IS CLOSE TO EACH OTHER ON THE
POSITION OF THE UPPER TROUGH AND RESULTING SURFACE PATTERN. GEFS
OUTPUT IS ALSO VERY SUPPORTIVE OF THE SLOWER SOLUTIONS WHICH ARE
THE GFS...ECMWF...UKMET AND CANADIAN.
SO WILL BASE FORECAST ON THOSE BUT CONFIDENCE IS A LITTLE BELOW
AVERAGE. MAIN SURFACE CONVERGENCE LIES NEAR THE WESTERN PORTION OF
THE FORECAST AREA ALONG WITH ACCOMPANYING MID/UPPER LIFT. CAP IS
ALSO THE WEAKEST THERE AS WELL. ALL THIS PLUS THE DETERMINISTIC QPF
AND GEFS PROBABILITY OF .05 SUPPORTS PULLING THE CHANCE OF
THUNDERSTORMS FURTHER WEST IN THE AFTERNOON. SO ADJUSTED THAT
ACCORDINGLY. AS STATED IN THE PREVIOUS FORECAST...MOISTURE COULD BE
THE LIMITING FACTOR ON COVERAGE AND SEVERITY. HOWEVER...LAPSE RATES
ARE VERY GOOD WITH VERY STRONG MID/UPPER LEVEL INDICATED...MAINLY
DURING THE EVENING. VERY STRONG PV ANOMALY ASSOCIATED WITH THIS
SYSTEM. PREVIOUS FORECAST HAS HIGH CHANCE IN THERE AND CONSIDERING
THE UNCERTAINTY BUT THE STRENGTH OF THE SYSTEM...FELT IT WAS
REASONABLE TO KEEP THOSE POPS.
VERY STRONG SYSTEM APPROACHING WILL CAUSE THE LEE TROUGH TO
STRENGTHEN EVEN MORE. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS
DEFINITELY SUPPORT WINDY/NEAR WIND ADVISORY CONDITIONS. SO INCREASED
WIND SPEEDS TO NEAR WIND ADVISORY. 850 MB TEMPERATURES SUPPORT
HAVING HIGH TEMPERATURES NEAR WHAT THE EXPECTED SATURDAY MAXES ARE.
SO ADJUSTED ACCORDINGLY.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 301 AM MDT FRI SEP 20 2013
EARLY MONDAY...ECMWF AND GFS PLACE THE UPPER LEVEL SHORTWAVE TROUGH
AXIS OVER NORTHEAST COLORADO WITH THE COLD FRONT BISECTING THE
FORECAST AREA. THE NAM IS THE MUCH FASTER OUTLIER AND PER WPC
MODEL DIAGNOSTICS DISCUSSION A BLEND OF THE GFS AND ECMWF IS
FAVORED FOR POSITION/TIMING. SHOWERS AND THUNDERSTORMS SHOULD BE
LIMITED TO THE EASTERN HALF OF THE FORECAST AREA MONDAY
MORNING...POSSIBLY THROUGH EARLY AFTERNOON DEPENDING ON TIMING.
AS THE SHORTWAVE TROUGH MOVES QUICKLY NORTHEAST...STRONG WESTERLY
MID/UPPER FLOW DEVELOPS OVER THE NORTHERN ROCKIES AND NORTHERN
PLAINS BY TUESDAY AND LEE SIDE TROUGH STRENGTHENS IN RESPONSE. VERY
SUBTLE UPPER LEVEL RIDGING MAY BE PRESENT ON TUESDAY BUT NOT ENOUGH
FOR TEMPERATURES TO SIGNIFICANTLY EXCEED NORMAL VALUES. A
SIGNIFICANT UPPER TROUGH WILL DEVELOP OVER THE WESTERN CONUS BY
WEDNESDAY. MODELS DISAGREE ON THE TIMING AND POSITION OF THIS
TROUGH...ALBEIT TO A LESSER EXTENT THAN PREVIOUS RUNS. GFS IS THE
QUICKEST AT EJECTING IT NORTHEASTWARD. EVEN SO...GFS ENSEMBLE MEAN
QPF REMAINS NORTH AND NORTHWEST OF THE FORECAST AREA THROUGH THE END
OF THE EXTENDED PERIOD...SO THE FORECAST REMAINS DRY BEYOND MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1147 PM MDT THU SEP 19 2013
VFR CONDITIONS WITH MOSTLY CLEAR SKIES WILL PREVAIL THROUGH THE
TAF PERIOD AT BOTH MCK AND GLD. LIGHT AND VARIABLE WINDS WILL BE
OBSERVED DURING THE REMAINDER OF TONIGHT AND INTO FRIDAY MORNING
WITH SURFACE HIGH PRESSURE OVER THE CENTRAL HIGH PLAINS REGION.
WINDS WILL BECOME LIGHT SOUTH TO SOUTHWEST AFTER 18Z AS THE HIGH
CENTER MOVES EAST OVER THE PLAINS STATES AND A LEE SURFACE TROUGH
BEGINS TO DEEPEN ALONG THE FRONT RANGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM..BRB
LONG TERM...BULLER
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1208 AM CDT Fri Sep 20 2013
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 950 PM CDT THU SEP 19 2013
Water vapor imagery and 00Z upper air analysis indicate an upper
level trough of low pressure drifting eastward across the Dakotas.
Meanwhile, upper level ridging is moving eastward across the
Intermountain West. Near the surface, a cold front extends from
the Texas Panhandle northeast into eastern Kansas. Cooler and
drier air has filtered south into western Kansas lowering surface
dewpoints primarily down into the 50s(F) with a few mid to upper
40s(F) closer to the Colorado border.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 145 PM CDT THU SEP 19 2013
Based on 18z surface analysis the surface cold front was
progressing across western Kansas slightly quicker than what the
12z GFS and 12z NAM suggested. The latest HRRR and RAP seems to be
tracking the front a little better earlier this afternoon so will
follow these models for the frontal location between 21z and 00z.
Convection is expected to begin to initiate near this boundary
late day given the afternoon instability progged and improving
upper level dynamic from the left entrance region of an weak upper
level jet crossing western Oklahoma. The current distribution of
precipitation chances across south central Kansas still looks on
track so other than adjusting the location of the front, no major
adjustments to the previous forecast is anticipated late today and
early tonight. SPC mesoanalysis indicating better 0-6km shear late
today so at this time can not rule the chance of a few
thunderstorms near the Oklahoma border. Quarter size hail, gusty
winds and periods of heavy rainfall currently appear to be the
main hazard late today.
Convection across south central Kansas and near the Oklahoma
border after sunset will taper off towards midnight and skies are
expected to begin to clear from north to south. Lows tonight will
be cooler than the past few nights and based on expected 09z to
12z dewpoints will keep lows mainly in the 50s.
High pressure at the surface will build into western Kansas on
Friday as an upper level ridge builds into the western high plains
from the west. The highs on Friday are expected to climb only into
the mid to upper 70s given that both the NAM and GFS suggest a 3c-
6c decrease in 925mb-850mb temperature from 00z Thursday to 00z
Friday.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 222 PM CDT THU SEP 19 2013
Mostly clear skies and dry conditions are anticipated Friday night
through Sunday morning as an upper level ridge moves over the
Central Plains, mid levels of the atmosphere remain dry, and a dome
of high pressure slides southeast of the area. The only exception to
this will be the possibility of a few cumulus clouds around peak
heating. Winds will generally be from the northeast Friday night
shifting to more of a southerly direction Saturday into Sunday
morning. Meanwhile, an upper level shortwave will be moving through
the Western United States Saturday then into the Central Rockies
Sunday. Mid to upper level moisture will be on the increase during
the day Sunday allowing for a few clouds to form. This shortwave
will also help push a cold front through the area Sunday night. A
few thunderstorms will be possible along and ahead of this front
with winds shifting to more of a southerly direction behind it. Cold
air advection will be short lived with this front as winds shift
back to a southerly direction Monday night through Wednesday. Flow
aloft becomes more zonal (west to east) Monday night through Tuesday
then more of a southwest direction Wednesday as the next shortwave
digs into the Intermountain West. Mostly clear skies and dry
conditions are expected over Western Kansas during this timeframe
with lee troughing strengthening across eastern Colorado.
Seasonable temperatures are expected Saturday with highs around 80
degrees and lows Saturday and Sunday morning in the 50s. Highs are
then expected to reach into the lower 80s Sunday and Monday with mid
80s Tuesday and Wednesday. Lows are forecasted to range from the
upper 50s to mid 60s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1207 AM CDT FRI SEP 20 2013
VFR conditions will prevail at all TAF sites through late this
afternoon. As for winds, surface high pressure will sink slowly
southward into western Kansas today resulting in light and variable
winds through Friday evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 80 57 83 / 0 0 0 0
GCK 52 81 58 84 / 0 0 0 10
EHA 53 81 59 84 / 0 0 0 10
LBL 52 82 59 85 / 0 0 0 10
HYS 50 81 57 82 / 0 0 0 0
P28 53 80 56 82 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Burgert
LONG TERM...Hovorka_42
AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS PADUCAH KY
240 PM CDT Fri Sep 20 2013
.SHORT TERM /Tonight through Sunday night/...
ISSUED AT 240 PM CDT FRI SEP 20 2013
Forecast seems to be panning out fairly well. Widespread rain has
overspread most of the forecast area this afternoon. Aside from a
convective cluster over western Kentucky...deep convection has been
largely absent. Instability has been limited by lack of solar
heating due to thickening mid/high clouds.
The qpf forecast seems to be on track...with the lowest amounts in
southern IL and southeast MO. Heavy rainfall is still occurring and
expected in western KY and possibly southwest IN. Due to dry
ground...any issues should be limited to urban and poor drainage
areas. Rainfall rates will continue to be locally over one inch per
hour in convection.
The latest HRRR is fairly close to the model consensus. The back
edge of the rain will move across the kpah/kevv areas in the 03z to
06z time frame. The precip will end in the khop area by 12z.
Clearing will occur on Saturday morning...with nothing more than
some scattered cu in the afternoon. 850 mb temps are forecast to
fall to around 10...which supports mos guidance highs in the mid
70s.
Little change in 850 mb temps or moisture profiles is forecast
through Sunday night. This will keep clear and cool conditions in
place...with daytime highs in the 70s and overnight lows in the mid
40s to near 50. North to northeast low level winds will slowly
decrease as high pressure builds overhead.
.LONG TERM /Monday through Friday/...
ISSUED AT 240 PM CDT FRI SEP 20 2013
As we head into next week, it now appears as though the upper level
high over the eastern U.S. will shift farther east as short wave
energy moves east into the MS River Valley. It still appears as
though our region may stay in between the two main branches of
energy, one passing to our north and the other just to our
south/east. If current trends continue, later forecasts may need to
mention a chc of rain in srn portions of west KY on Tuesday/Tue
night.
Thereafter...the upper high over the southeast U.S. will begin to
flex its muscle, and build north into the Ohio Valley. Thus... we
should see less cloud cover and warming temps as we head into the
Wed/Thu/Fri time frame. Most locations will likely be back into the
middle 80s by Wednesday afternoon. Humidity levels should stay
fairly comfortable until late in the week, when southerly flow will
develop ahead of an approaching cold front.
&&
.AVIATION...
ISSUED AT 1237 PM CDT FRI SEP 20 2013
Cold front pushing into the region 22z-02z, turning winds from
west to north around 10 kts after the passage. Expect numerous
showers and MVFR vsbys/cigs ahead of the front. Cannot rule out
isolated thunder along and south of the OH River until the front
passes. May also be a period of IFR/Low IFR behind the front in
light rain or DZ. Skies should finally clear 08-12z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...MY
LONG TERM...GM
AVIATION...GM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1032 AM EDT FRI SEP 20 2013
.SYNOPSIS...
A COLD FRONT WILL BRING RAIN TONIGHT AND SATURDAY. HIGH PRESSURE
WILL THEN BRING A STRETCH OF DRY WEATHER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH 845AM UPDATE...PRIMARY CHANGE WAS TO POPS FOR THE MORNING AND
EARLY AFTERNOON HOURS. A LINE OF RAIN HAS DEVELOPED OVER THE LAST
1-2 HOURS ACROSS THE NORTHERN WEST VIRGINIA PANHANDLE...WHICH
APPEARS TO BE ALIGNED ALONG A 850MB TEMPERATURE GRADIENT. THE RAP
AND HRRR BOTH SHOW THE LINE PERSISTING FOR THE NEXT SEVERAL
HOURS...AND HAVE RAISED POPS ALONG THIS LINE. AS THE GRADIENT
MOVES EAST...HAVE BLENDED POPS BACK INTO PREVIOUS FORECAST BY LATE
AFTERNOON. ALSO INCREASED CLOUD COVER INTO THE MID MORNING. AM
STILL BEING SOMEWHAT OPTIMISTIC THAT CLOUD COVER WILL BEGIN TO
DISSIPATE LATER THIS MORNING...BUT A MORE REALISTIC SCENARIO MAY
BE SIMILAR TO YESTERDAY...WHERE CLEARING DID NOT OCCUR UNTIL
EARLY-MID AFTERNOON.
PREVIOUS...
SHOWER ACTIVITY HAS DEVELOPED OVER PORTIONS OF NW OHIO...WESTERN
LAKE ERIE AND FURTHER NORTHWARD OVER LAKE HURON. THE BULK OF THIS
ACTIVITY IS MOVING NORTHEASTWARD ON THE LEADING EDGE OF A COUPLE
OF WEAK SHORTWAVES. IT APPEARS THAT THE CONVECTION IS BLOSSOMING
DUE TO THE ENERGY MOVING THROUGH AN AREA OF INCREASED ELEVATED
INSTABILITY. THIS SPECIFIC INSTABILITY WILL SPREAD EASTWARD THIS
MORNING. ANOTHER WAVE WILL DEVELOP AND MOVE ACROSS EASTERN OHIO
LATE THIS MORNING AND THEN DRIFT SOUTHEASTWARD INTO NORTHERN WEST
VIRGINIA. WILL CONTINUE WITH SLIGHT CHC/LOW CHC POPS OVER THE
WESTERN HALF TODAY.
LOOKING AT LATEST SOUNDINGS...MIXING LAYER REMAINS AROUND 1000FT
UNTIL MID TO LATE MORNING AND THEN RISES QUICKLY. AT THE SAME
TIME...THE ATMOSPHERE DRIES OUT...LIKELY DUE TO THE SUBSIDENCE
FROM THE RIDGE AND THE PUSH OF WAA ALOFT. WILL HOLD ONTO CLOUD
COVER THROUGH MOST OF THE MORNING THEN INCREASE SUNSHINE IN THE
AFTERNOON...MAINLY IN THE EAST. WITH AN INCREASE IN SUNSHINE AND
A MODEST DESTABILIZATION OF THE ATMOSPHERE...A SHOWER OR STORM
COULD POP UP...THIS AFTERNOON.
TEMPS WILL BE TRICKY TODAY. WITH LOW CLOUDS MIXING OUT...MIXING
LAYER INCREASING AND THUS TAPING INTO THE WARMER AIR ALOFT...WILL
GO JUST ABOVE GUIDANCE TODAY FOR HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
STILL TIMING ISSUES BETWEEN THE MODEL SOLUTIONS WITH FRONTAL
PASSAGE. NAM AND NOW THE SREF ARE THE FASTEST...GFS THE SLOWEST
AND THE ECMWF SOMEWHERE IN BETWEEN. TIMING DIFFERENCE BETWEEN THE
NAM/SREF SOLUTION AND THE GFS IS ABOUT 4 TO 6 HOURS. NATURALLY,
THIS WILL HAVE AN EFFECT ON BEGINNING/END TIMES...BUT OVERALL THIS
DISCREPANCY IS MANAGEABLE. EVER SO SUBTLY THE MODELS ARE GETTING
CLOSER. WILL CONTINUE WITH A MIDDLE OF THE ROAD APPROACH...
BRINGING CAT POPS TO PIT BY 06-08Z AND THEN COVERING THE ENTIRE AREA
BY 12-14Z SAT. GFS CONTINUES TO DEVELOP A SURFACE LOW ALONG THE
FRONT...BUT IT IS LESS DEFINED AND NOT AS LONG LIVED AS YESTERDAYS
RUN.
AS THE MODELS CONTINUE TO RESOLVE ASPECTS OF THE SYSTEM...CONVECTION
IS BECOMING LESS AND LESS LIKELY. ONCE AGAIN THE ATMOSPHERE
STABILIZES TONIGHT...AND WHAT LOW AND MID LEVEL FORCING...APPARENT
YESTERDAY...IS NO LONGER AS PRONOUNCED. THE MOISTURE CONVERGENCE
IS ALSO LESS ORGANIZED AND WHAT DOES EXIST SEEMS SOMEWHAT SUSPECT.
SHEAR IS NOT BAD WITH 0-6 KM BULK SHEAR AROUND 30 TO 35KTS RIGHT
ALONG THE FRONT. THE QUESTION IS WILL ANYTHING BE ABLE TO GET
STARTED...PARTICULARLY AS SHOWERS SPREAD OUT AHEAD OF THE
BOUNDARY AND COOL THE PRE-FRONTAL ATMOSPHERE. I SUPPOSE IF ISO
CONVECTION DOES GET ROLLING...WHICH WOULD BE RIGHT ALONG THE
FRONT... HEAVY DOWNPOURS ARE A GOOD BET AS PWATS REMAIN IN THE 1.7
RANGE. NOT NEARLY AS CONCERNED WITH THE WIND THREAT AS THE
MDPI/WINDEX IS VERY LOW.
CONTINUING WITH A MODEL COMPROMISE...THE BACK EDGE OF THE RAIN
SHOULD BEGIN TO REACH THE FAR WEST BY LATE SATURDAY MORNING...
REACHING THE FAR EAST BY LATE AFTERNOON. POST FRONTAL RAIN WILL BE
JUST THAT...RAIN. THE LARGE UPPER LEVEL LOW DIGGING INTO THE
NORTHERN GREAT LAKES SATURDAY WILL HELP TO PUSH THE FRONT
EASTWARD. IF THIS LOW COMES IN FASTER...RAIN WILL END SOONER.
NORTHWEST FLOW AND STRONG CAA ALOFT WILL PROVIDE MUCH COOLER TEMPS
BY SUNDAY. THIS WILL ALSO MEAN A GOOD DEAL OF CLOUD COVER ON
SUNDAY. WILL LEAVE THE AREA DRY...BUT AN ISO SHOWER IS POSSIBLE IN
THIS REGIME.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STRONG SURFACE HIGH WILL BUILD OVERHEAD AND DOMINATE FOR MUCH OF
THE LONG TERM PERIOD. TEMPERATURES WILL START OUT BELOW SEASONAL
AVERAGES MONDAY AND GRADUALLY WARM TO NEAR NORMAL BY THURSDAY.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
MVFR AND PTCHY IFR CONDS WL CONT ACRS MUCH OF THE AREA THRU ERLY
AFTN. A BAND OF SHWRS HAS DVLPD ALG A WK DISTURBANCE AND WL BE
AFFECTING PORTS GENLY S OF BVI. SOME DOWNSLOPING E OF PIT HAS
ALLOWED FOR VFR AT LBE AND MGW AND THIS SHOULD CONT.
IMPROVEMENT IS ANTICIPATED THIS AFTN AS MIXING AND SBSDNC IMPROVE
VIA HTG AND RISING HTS IN ADVN OF DEEPENING MIDWRN TROF. SHWRS ARE
POSSIBLE OVR EC OHIO LTR THIS AFTN AS THE TROF/CDFNT DRAWS
CLOSER...HENCE WL COVER THE SCENARIO WITH A VC MENTION AT
ZZV...AND WL EXPAND THE MENTION INTO OTHER TERMINALS AS EVENING
FALLS.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
WIDESPREAD RESTRICTIONS CAN BE EXPECTED THROUGH SAT NGT AS RAIN
DVLPS WITH A CROSSING CDFNT. HIGH PRES WL BUILD IN THE WAKE OF THE
FRONT AND RTN GENL VFR FOR THE FIRST HALF OF NXT WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
844 AM EDT FRI SEP 20 2013
.SYNOPSIS...
A COLD FRONT WILL BRING RAIN TONIGHT AND SATURDAY. HIGH PRESSURE
WILL THEN BRING A STRETCH OF DRY WEATHER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WITH 845AM UPDATE...PRIMARY CHANGE WAS TO POPS FOR THE MORNING AND
EARLY AFTERNOON HOURS. A LINE OF RAIN HAS DEVELOPED OVER THE LAST
1-2 HOURS ACROSS THE NORTHERN WEST VIRGINIA PANHANDLE...WHICH
APPEARS TO BE ALIGNED ALONG A 850MB TEMPERATURE GRADIENT. THE RAP
AND HRRR BOTH SHOW THE LINE PERSISTING FOR THE NEXT SEVERAL
HOURS...AND HAVE RAISED POPS ALONG THIS LINE. AS THE GRADIENT
MOVES EAST...HAVE BLENDED POPS BACK INTO PREVIOUS FORECAST BY LATE
AFTERNOON. ALSO INCREASED CLOUD COVER INTO THE MID MORNING. AM
STILL BEING SOMEWHAT OPTIMISTIC THAT CLOUD COVER WILL BEGIN TO
DISSIPATE LATER THIS MORNING...BUT A MORE REALISTIC SCENARIO MAY
BE SIMILAR TO YESTERDAY...WHERE CLEARING DID NOT OCCUR UNTIL
EARLY-MID AFTERNOON.
PREVIOUS...
SHOWER ACTIVITY HAS DEVELOPED OVER PORTIONS OF NW OHIO...WESTERN
LAKE ERIE AND FURTHER NORTHWARD OVER LAKE HURON. THE BULK OF THIS
ACTIVITY IS MOVING NORTHEASTWARD ON THE LEADING EDGE OF A COUPLE
OF WEAK SHORTWAVES. IT APPEARS THAT THE CONVECTION IS BLOSSOMING
DUE TO THE ENERGY MOVING THROUGH AN AREA OF INCREASED ELEVATED
INSTABILITY. THIS SPECIFIC INSTABILITY WILL SPREAD EASTWARD THIS
MORNING. ANOTHER WAVE WILL DEVELOP AND MOVE ACROSS EASTERN OHIO
LATE THIS MORNING AND THEN DRIFT SOUTHEASTWARD INTO NORTHERN WEST
VIRGINIA. WILL CONTINUE WITH SLIGHT CHC/LOW CHC POPS OVER THE
WESTERN HALF TODAY.
LOOKING AT LATEST SOUNDINGS...MIXING LAYER REMAINS AROUND 1000FT
UNTIL MID TO LATE MORNING AND THEN RISES QUICKLY. AT THE SAME
TIME...THE ATMOSPHERE DRIES OUT...LIKELY DUE TO THE SUBSIDENCE
FROM THE RIDGE AND THE PUSH OF WAA ALOFT. WILL HOLD ONTO CLOUD
COVER THROUGH MOST OF THE MORNING THEN INCREASE SUNSHINE IN THE
AFTERNOON...MAINLY IN THE EAST. WITH AN INCREASE IN SUNSHINE AND
A MODEST DESTABILIZATION OF THE ATMOSPHERE...A SHOWER OR STORM
COULD POP UP...THIS AFTERNOON.
TEMPS WILL BE TRICKY TODAY. WITH LOW CLOUDS MIXING OUT...MIXING
LAYER INCREASING AND THUS TAPING INTO THE WARMER AIR ALOFT...WILL
GO JUST ABOVE GUIDANCE TODAY FOR HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
STILL TIMING ISSUES BETWEEN THE MODEL SOLUTIONS WITH FRONTAL
PASSAGE. NAM AND NOW THE SREF ARE THE FASTEST...GFS THE SLOWEST
AND THE ECMWF SOMEWHERE IN BETWEEN. TIMING DIFFERENCE BETWEEN THE
NAM/SREF SOLUTION AND THE GFS IS ABOUT 4 TO 6 HOURS. NATURALLY,
THIS WILL HAVE AN EFFECT ON BEGINNING/END TIMES...BUT OVERALL THIS
DISCREPANCY IS MANAGEABLE. EVER SO SUBTLY THE MODELS ARE GETTING
CLOSER. WILL CONTINUE WITH A MIDDLE OF THE ROAD APPROACH...
BRINGING CAT POPS TO PIT BY 06-08Z AND THEN COVERING THE ENTIRE AREA
BY 12-14Z SAT. GFS CONTINUES TO DEVELOP A SURFACE LOW ALONG THE
FRONT...BUT IT IS LESS DEFINED AND NOT AS LONG LIVED AS YESTERDAYS
RUN.
AS THE MODELS CONTINUE TO RESOLVE ASPECTS OF THE SYSTEM...CONVECTION
IS BECOMING LESS AND LESS LIKELY. ONCE AGAIN THE ATMOSPHERE
STABILIZES TONIGHT...AND WHAT LOW AND MID LEVEL FORCING...APPARENT
YESTERDAY...IS NO LONGER AS PRONOUNCED. THE MOISTURE CONVERGENCE
IS ALSO LESS ORGANIZED AND WHAT DOES EXIST SEEMS SOMEWHAT SUSPECT.
SHEAR IS NOT BAD WITH 0-6 KM BULK SHEAR AROUND 30 TO 35KTS RIGHT
ALONG THE FRONT. THE QUESTION IS WILL ANYTHING BE ABLE TO GET
STARTED...PARTICULARLY AS SHOWERS SPREAD OUT AHEAD OF THE
BOUNDARY AND COOL THE PRE-FRONTAL ATMOSPHERE. I SUPPOSE IF ISO
CONVECTION DOES GET ROLLING...WHICH WOULD BE RIGHT ALONG THE
FRONT... HEAVY DOWNPOURS ARE A GOOD BET AS PWATS REMAIN IN THE 1.7
RANGE. NOT NEARLY AS CONCERNED WITH THE WIND THREAT AS THE
MDPI/WINDEX IS VERY LOW.
CONTINUING WITH A MODEL COMPROMISE...THE BACK EDGE OF THE RAIN
SHOULD BEGIN TO REACH THE FAR WEST BY LATE SATURDAY MORNING...
REACHING THE FAR EAST BY LATE AFTERNOON. POST FRONTAL RAIN WILL BE
JUST THAT...RAIN. THE LARGE UPPER LEVEL LOW DIGGING INTO THE
NORTHERN GREAT LAKES SATURDAY WILL HELP TO PUSH THE FRONT
EASTWARD. IF THIS LOW COMES IN FASTER...RAIN WILL END SOONER.
NORTHWEST FLOW AND STRONG CAA ALOFT WILL PROVIDE MUCH COOLER TEMPS
BY SUNDAY. THIS WILL ALSO MEAN A GOOD DEAL OF CLOUD COVER ON
SUNDAY. WILL LEAVE THE AREA DRY...BUT AN ISO SHOWER IS POSSIBLE IN
THIS REGIME.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STRONG SURFACE HIGH WILL BUILD OVERHEAD AND DOMINATE FOR MUCH OF
THE LONG TERM PERIOD. TEMPERATURES WILL START OUT BELOW SEASONAL
AVERAGES MONDAY AND GRADUALLY WARM TO NEAR NORMAL BY THURSDAY.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
IFR AND LOW END MVFR ST AND FOG WL CONT TO PLAGUE UPR OH VALLEY
TERMINALS THIS MRNG AS A WEAK DISTURBANCE PRVDS BROAD ASCENT OVR
A SATURATED...BUT CAPPED BNDRY LYR. SOME -SHWRS MAY ALSO AFFECT THE
ZZV AND HLG AREAS THROUGH THE POSTDAWN HRS AS WEAK ELEVATED
CONVECTION OVR OH SHOULD PERSIST GIVEN MDL SOUNDING- PROGNOSIS.
THE OTHER EXCEPTIONS MAY BE AT LBE AND MGW WHERE DOWNSLOPE MAY BE
SUFFICIENT TO OFFSET THE MSTR POOLING UNDR THE INVERSION.
RAPID IMPROVEMENT IS ANTICIPATED LTR THIS MRNG AS MIXING AND
SBSDNC IMPROVE VIA HTG AND RISING HTS IN ADVN OF DEEPENING MIDWRN
TROF. SHWRS ARE POSSIBLE OVR EC OHIO LTR THIS AFTN AS THE
TROF/CDFNT DRAWS CLOSER...HENCE WL COVER THE SCENARIO WITH A VC
MENTION AT ZZV...AND WL EXPAND THE MENTION INTO OTHER TERMINALS AS
EVENING FALLS.
.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
WIDESPREAD RESTRICTIONS CAN BE EXPECTED THROUGH SAT NGT AS RAIN
DVLPS WITH A CROSSING CDFNT. HIGH PRES WL BUILD IN THE WAKE OF THE
FRONT AND RTN GENL VFR FOR THE FIRST HALF OF NXT WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
359 AM CDT FRI SEP 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 359 AM CDT FRI SEP 20 2013
IT IS NO WONDER WHY MN/WI/IA SAW STRONG TO SEVERE THUNDERSTORMS ALL
DAY YESTERDAY AND LAST NIGHT. THAT IS ONE POTENT WAVE MAKING ITS WAY
ACROSS THE UPPER MISSISSIPPI RIVER VALLEY THIS MORNING. THERE ARE
100-120 METER 12-HR 500 MB HEIGHT FALLS ACROSS MN...NICE DRYING ON
THE WATER VAPOR DRIVING INTO MN...AND A 100 KT 250 MB JET OVERHEAD
AS EVIDENT BY THE 07Z WOOD LAKE PROFILER. THERE HAS BEEN STRONG
925-850 MB COLD ADVECTION SINCE 00Z LAST EVENING AND EVEN WITH CLOUD
COVER LAST EVENING...MOST OF THE FORECAST AREA IS 10-15 COOLER RIGHT
NOW THAN WE WERE 24 HOURS AGO. THE PWAT WENT FROM A TWO STANDARD
DEVIATION ABOVE NORMAL 1.54" AT 12Z YESTERDAY TO A MORE MODEST 1.22"
AT 00Z LAUNCH LAST EVENING OFF THE MPX SOUNDING. WE SHOULD BE MUCH
DRIER WITH THE LAUNCH THIS MORNING. THERE ARE A COUPLE AREAS OF
LIGHT SHOWERS THIS MORNING. THE FIRST IS NOW IN WEST CENTRAL WI OUT
AHEAD OF THE TROUGH AND THE SECOND IS NEAR THE SD/ND/MN BORDER NEAR
THE TROUGH AXIS. TODAY WILL FEATURE...LOW STRATO CU CLOUDS WITH
ISOLATED TO SCATTERED LIGHT RAIN SHOWERS AND A BREEZY NORTHWEST WIND
- TYPICAL POST FRONTAL FALL-LIKE WEATHER. CENTRAL MN SHOULD STRUGGLE
TO HIT 60 FOR A HIGH AND THE WIND WILL MAKE IT FEEL EVEN COOLER
TODAY ACROSS MN/WI. THERE IS LITTLE CHANCE OF SEEING MUCH SUN
TODAY...CEILINGS SHOULD LIFT IN THE AFTERNOON AND THE LIGHT RAIN
SHOWERS BECOME MUCH MORE SPARSE LATE IN THE DAY...BUT THE RH
TIME/HEIGHT PLOTS OFF ALMOST EVERY PIECE OF GUIDANCE KEEP LOW CLOUDS
AROUND THROUGH SUNSET. THAT BEING SAID...IF THERE IS HOPE FOR
SIGNIFICANT SUNSHINE TODAY...IT IS IN WESTERN MN. ELSEWHERE...IT
WILL LIKELY REMAIN BROKEN TO OVERCAST THROUGH THE DAY. CLEARING
TONIGHT SETS THE STAGE FOR CHILLY OVERNIGHT LOWS IN THE UPPER 30S
AND LOWER 40S. NO MENTION OF FROST IN THE FORECAST AS WE WILL LIKELY
REMAIN A FEW DEGREES TOO WARM...BUT WITH A WEAK SURFACE HIGH BUILDING
IN ACROSS WESTERN MN...SOME PATCHY FROST CAN NOT COMPLETELY BE RULED
OUT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 359 AM CDT FRI SEP 20 2013
THE LONG TERM LOOKS QUIET BUT RATHER PLEASANT AS TROUGHING TAKES
HOLD ACROSS THE WESTERN CONUS AND A PERSISTENT RIDGE REMAINS OVER
THE SOUTHEAST. THE HESITATION TO KICK OUT THE SOUTHEASTERN RIDGE
WILL TEND TO WEAKEN SHORT WAVES AS THEY EJECT EAST/NORTHEASTWARD
DURING THE PERIOD. TIMING OF THESE SYSTEMS IS ALSO UNCERTAIN WITH
EACH MODEL RUN SLOWING DOWN THEIR PROGRESSION SLIGHTLY. THIS
SPELLS A PROLONGED PERIOD OF WARM TEMPERATURES AND MAINLY DRY
WEATHER.
SURFACE HIGH PRESSURE WILL BE LOCATED OVER MINNESOTA SATURDAY AND
WISCONSIN SATURDAY NIGHT. THESE PERIODS WILL BE THE COOLEST FOR
THE NEXT 7 DAYS WITH AREAS OF FROST EXPECTED OVER WISCONSIN EARLY
SUNDAY MORNING. WESTERN MINNESOTA WILL BE IN THE RETURN FLOW
REGIME AND THUS CONSIDERABLY WARMER NEAR 50. THIS RETURN FLOW WILL
ENVELOP THE REST OF THE AREA SUNDAY AS THE HIGH PUSHES A BIT
FURTHER EAST AND THE PRESSURE GRADIENT TIGHTENS AS LOW PRESSURE
DEEPENS OVER THE PLAINS. WIND GUSTS OF 35 TO 40 MPH ARE PROBABLE IN
THE MN RIVER VALLEY. HIGHS ARE A BIT MORE UNCERTAIN GIVEN A RATHER
IMPRESSIVE GRADIENT EXPECTED ACROSS THE AREA. THERMAL RIDGING
SHOULD BE EXPANDING EASTWARD INTO AT LEAST WRN MN BY
AFTERNOON...WHICH WOULD SUPPORT HIGHS IN THE 80S. FURTHER
EAST...THESE TEMPERATURES WILL TAPER TO THE MID 60S ACROSS WI.
THE LOW WILL BE ABSORBED INTO A LARGE CANADIAN CYCLONE MONDAY.
MID LEVEL ENERGY EJECTING FROM THE SOUTHWEST WILL WEAKEN
CONSIDERABLY AND MOST MODELS FINALLY SHOW A DRY FORECAST ACROSS
THE AREA MONDAY/MONDAY NIGHT. COULD SEE A FEW LEFTOVER SHOWERS OR
SPRINKLES PASS OVERHEAD...BUT DRY BOUNDARY LAYER AIR WILL MAKE
EVEN THIS DIFFICULT. CONTINUED TO REDUCE POPS AND THE NEXT SHIFT
OR TWO MAY COMPLETELY REMOVE THEM.
A DEEP TROUGH WILL BEGIN TO DEVELOP OVER THE WESTERN CONUS DURING
THE MIDDLE OF NEXT WEEK. MERIDIONAL FLOW OVER THE CENTRAL CONUS
WILL SLOW THE EASTWARD PROGRESSION OF THIS TROUGH FROM WHAT THE
MODELS INDICATE...ALTHOUGH THEY ARE SLOWER THIS MORNING THAN
PREVIOUS RUNS. REMOVED POPS FROM TUESDAY-WEDNESDAY AND REDUCED
THEM WEDNESDAY NIGHT/THURSDAY WITH KINEMATICS AND FRONTAL
BOUNDARIES WELL OFF TO THE NORTH AND WEST OF THE AREA. AS WINDS
VEER SLIGHTLY MORE SOUTH OR SOUTHWESTERLY...DEEPER MOISTURE AND
WARMER TEMPERATURES WILL ARRIVE AND WE COULD SEE LOWS IN THE 60S
AND HIGHS IN THE 80S WEDNESDAY AND THURSDAY. HARD TO IMAGINE THESE
TEMPERATURES WILL LAST MUCH LONGER AS WE HEAD TOWARD OCTOBER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1047 PM CDT THU SEP 19 2013
STILL EXPECTING THE STRATUS DECK OVER ERN ND TO EXPAND SOUTHEAST
OVERNIGHT ACROSS THE TAF SITES...AND CAUSE CIGS TO GRADUALLY LOWER
TO MVFR /POSSIBLY EVEN IFR AT TIMES/ BETWEEN 06Z AND 12Z FRIDAY.
CONTINUE TO FAVOR THE RAP AND HRRR MODELS...WHICH BRING LOW CIGS
INTO NORTHERN-MOST SITES /KAXN AND KSTC/ BETWEEN 06Z AND
08Z...THEN EAST AND SOUTH TO THE REACH THE REMAINDER OF THE SITES
BY DAYBREAK. THEN EXPECT CIGS TO STAY BKN-OVC IN THE MVFR LEVEL
THROUGH MUCH OF THE MORNING...SHOWING IMPROVEMENT DURING THE
AFTERNOON. THE DIRECTIONAL COMPONENT OF THE WIND WILL GENERALLY
VARY FROM 280-310 DEGREES THROUGH THE PERIOD. SPEEDS AOB 10KTS
THROUGH THE NIGHT...BECOMING GUSTY /UPPER TEENS TO LOWER 20S IN
KNOTS/ AGAIN AFTER 14Z FRIDAY. WIDELY SCATTERED LIGHT RAIN SHOWERS
/VFR VSBYS/ WILL ALSO BE POSSIBLE ON FRIDAY AS THE TROUGH ROTATES
OVER...ALTHOUGH COVERAGE/PROBABILITY IS TOO LOW TO WARRANT
INCLUSION IN THE TAFS AT THIS TIME.
KMSP...
STRATUS CLOUDS WITH MVFR CIGS ARE EXPECTED AROUND 10Z...AND
POSSIBLY BELOW 1700 FT FOR A WINDOW OF TIME BETWEEN 12Z AND 18Z.
SCATTERING OUT IS THEN EXPECTED GRADUALLY THROUGHOUT THE AFTERNOON.
WINDS 280-310 DIRECTIONALLY AOA 9KTS THROUGH THE PERIOD...GUSTING
TO BETWEEN 20 AND 24 KTS AFTER 15Z FRIDAY.
/OUTLOOK FOR KMSP/
SAT...VFR. NORTHWEST WIND 5 KTS.
SUN...VFR. SOUTHEAST WIND 12-15 KTS.
MON...VFR. SOUTHEAST WIND 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...BORGHOFF
AVIATION...LS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1257 PM CDT Fri Sep 20 2013
.UPDATE:
Issued at 1040 AM CDT Fri Sep 20 2013
15z surface obs show cold front knocking on the door of STL metro,
just to the NW, and is expected to move thru during the midday
hours. Low clouds expected to linger for a couple hours after
FROPA, with a thick CS cloud deck hanging around for thru the rest
of the afternoon over many areas. This thick cloud cover will
result in limited sunshine and combined with somewhat decent lo
level CAA, will result in very limited temp recoveries behind the
front today with most locales seeing near steady temps.
Substantial clearing will take place early this evening with
expected departure of thick high clouds and associated temp and
wind dropoff will occur as well.
Rain will experience one final surge slightly back to the NW as it
rides up I-44 in MO during the midday and early afternoon hours
before it then accelerates off and out of the area later in the
afternoon. Some patchy drizzle has also been reported near and
just behind the cold front and have added that in as well,
sharpening up the gradient between areas that should receive
measurable rainfall from those that do not but may still see some
precipitation. Removed thunder from forecast with instability very
limited from here on out.
TES
&&
.SHORT TERM: (Through Tonight)
Issued at 326 AM CDT Fri Sep 20 2013
Main concern will be how quickly the rain will exit the area today.
Cold front currently extends from Kirksville to Sedalia to Nevada.
Ahead of it, there is a large band of rain with the leading edge
of the thunderstorms extending from just northeast of metro St.
Louis southwestward West Plains. This line should continue to
move east in the near term...though there will continue to be some
weakening in this line as the RAP shows the 925-850mb moisture
convergence diminishing. The cold front will continue to move
southeast today, clearing the CWA by 21Z. The main band of rain
with embedded thunderstorms will be found ahead of it, aided by
ascent from the front and the deep upper through moving across the
central CONUS. This is generally follows the latest runs of the
HRRR which shows rain slowly spreading southeast with time.
With clouds and rain today, temperatures will be much cooler than
yesterday. Some locations in south and east may not see much
diurnal recovery.
Britt
.LONG TERM: (Saturday through Wednesday)
Issued at 326 AM CDT Fri Sep 20 2013
Forecast remains dry in the long term. Strong subsidence sets in
the wake of the upper trough as upper ridge builds in over the
region by late Sunday. Deep trough that enters the West Coast over
the weekend still shears out before it can give us any rain. Then
GFS/ECMWF both begin to amplify pattern over the CONUS by the
middle of next week with a trough over the Rockies and ridge over
the Mississippi Valley on Wednesday.
A dry airmass and light winds/mainly clear skies should allow for
some excellent radiational cooling at night. Went a few degrees
below guidance for lows over the weekend into early next week.
Britt
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1257 PM CDT Fri Sep 20 2013
Cold front at 17z was moving thru the NW half of STL metro and is
expected to make its way thru the TAF sets there between now and
20z. IFR CIGs and MVFR VSBYs in drizzle are expected in the
frontal zone from time to time. Improving conditions to VFR will
then occur late this afternoon in this area with VFR for the
remainder of the valid period. KUIN and KCOU will remain VFR thru
the valid period. Otherwise, NW-N surface winds can be anticipated
for the valid period for those areas behind the front.
Specifics for KSTL: Cold front at 17z had moved thru KSET and was
almost to the terminal where a wind shift out of the NW will
occur. IFR CIGs and MVFR VSBYs in drizzle can also be expected in
the frontal zone from time to time until around 20z, although
delays and slowdowns seem to be the theme of the fronts movement
as of late. Rapidly improving conditions to VFR will then occur
late this afternoon with VFR for the remainder of the valid
period. Fog is not forecast due to rapid drying also expected to
occur tonight. Otherwise, NW-N surface winds can be anticipated
for the valid period.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1040 AM CDT Fri Sep 20 2013
.UPDATE:
Issued at 1040 AM CDT Fri Sep 20 2013
15z surface obs show cold front knocking on the door of STL metro,
just to the NW, and is expected to move thru during the midday
hours. Low clouds expected to linger for a couple hours after
FROPA, with a thick CS cloud deck hanging around for thru the rest
of the afternoon over many areas. This thick cloud cover will
result in limited sunshine and combined with somewhat decent lo
level CAA, will result in very limited temp recoveries behind the
front today with most locales seeing near steady temps.
Substantial clearing will take place early this evening with
expected departure of thick high clouds and associated temp and
wind dropoff will occur as well.
Rain will experience one final surge slightly back to the NW as it
rides up I-44 in MO during the midday and early afternoon hours
before it then accelerates off and out of the area later in the
afternoon. Some patchy drizzle has also been reported near and
just behind the cold front and have added that in as well,
sharpening up the gradient between areas that should receive
measurable rainfall from those that do not but may still see some
precipitation. Removed thunder from forecast with instability very
limited from here on out.
TES
&&
.SHORT TERM: (Through Tonight)
Issued at 326 AM CDT Fri Sep 20 2013
Main concern will be how quickly the rain will exit the area today.
Cold front currently extends from Kirksville to Sedalia to Nevada.
Ahead of it, there is a large band of rain with the leading edge
of the thunderstorms extending from just northeast of metro St.
Louis southwestward West Plains. This line should continue to
move east in the near term...though there will continue to be some
weakening in this line as the RAP shows the 925-850mb moisture
convergence diminishing. The cold front will continue to move
southeast today, clearing the CWA by 21Z. The main band of rain
with embedded thunderstorms will be found ahead of it, aided by
ascent from the front and the deep upper through moving across the
central CONUS. This is generally follows the latest runs of the
HRRR which shows rain slowly spreading southeast with time.
With clouds and rain today, temperatures will be much cooler than
yesterday. Some locations in south and east may not see much
diurnal recovery.
Britt
.LONG TERM: (Saturday through Wednesday)
Issued at 326 AM CDT Fri Sep 20 2013
Forecast remains dry in the long term. Strong subsidence sets in
the wake of the upper trough as upper ridge builds in over the
region by late Sunday. Deep trough that enters the West Coast over
the weekend still shears out before it can give us any rain. Then
GFS/ECMWF both begin to amplify pattern over the CONUS by the
middle of next week with a trough over the Rockies and ridge over
the Mississippi Valley on Wednesday.
A dry airmass and light winds/mainly clear skies should allow for
some excellent radiational cooling at night. Went a few degrees
below guidance for lows over the weekend into early next week.
Britt
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 553 AM CDT Fri Sep 20 2013
COLD FRONT MOVING THROUGH THE AREA WILL BE THE FOCUS OF THE
FORECAST. FRONT SHOULD BE THROUGH UIN AND COU IN A 12 - 13Z
TIMEFRAME. PRECIPITATION HAS MOVED WELL SOUTH OF THESE AREA SO
THEY LOOK TO STAY DRY. MDLS ARE TRYING TO HOLD PRECIP ALONG I-44
SOUTH UNTIL ABOUT MIDDAY. WITH THE UPPER TROF HANGING BACK THIS IS
CERTAINLY POSSIBLE. HOWEVER RADAR LOOPS SHOW A SHRINKING TREND AND
A DECENT PUSH TO THE SOUTHEAST ALONG THE BACK EDGE. THUS I WILL
KEEP MOST OF THE LINGERING LIGHT RAIN SOUTH AND EAST OF ANY
TERMINALS. OTHER ISSUE WILL BE IFR/MFVR CEILINGS BEHIND THE FRONT.
CURRENT OBSERVATION SHOW A MIXED BAD OF CLOUDS SO DON`T FEEL ANY
ONE DIRECTION WILL BE THE ANSWER. UIN LOOKS TO BE IFR FOR A COUPLE
OF HOURS AND COU MAY COME DOWN...BUT WILL NOT HOLD IT IN LONG.
Specifics for KSTL: FRONT SHOULD BE THROUGH ABOUT 15 - 16Z. WILL
KEEP SOME LIGHT RAIN IN...6SM UNTIL THEN...ALTHOUGH THAT MAY BE
TOO LONG. RADAR ECHOES CONTINUE TO SHRINK. SOME IFR CLOUDS IN THE
AREA BUT DO NOT EXPECT THEM TO HOLD LONG.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
611 AM CDT Fri Sep 20 2013
.SHORT TERM: (Through Tonight)
Issued at 326 AM CDT Fri Sep 20 2013
Main concern will be how quickly the rain will exit the area today.
Cold front currently extends from Kirksville to Sedalia to Nevada.
Ahead of it, there is a large band of rain with the leading edge
of the thunderstorms extending from just northeast of metro St.
Louis southwestward West Plains. This line should continue to
move east in the near term...though there will continue to be some
weakening in this line as the RAP shows the 925-850mb moisture
convergence diminishing. The cold front will continue to move
southeast today, clearing the CWA by 21Z. The main band of rain
with embedded thunderstorms will be found ahead of it, aided by
ascent from the front and the deep upper through moving across the
central CONUS. This is generally follows the latest runs of the
HRRR which shows rain slowly spreading southeast with time.
With clouds and rain today, temperatures will be much cooler than
yesterday. Some locations in south and east may not see much
diurnal recovery.
Britt
.LONG TERM: (Saturday through Wednesday)
Issued at 326 AM CDT Fri Sep 20 2013
Forecast remains dry in the long term. Strong subsidence sets in
the wake of the upper trough as upper ridge builds in over the
region by late Sunday. Deep trough that enters the West Coast over
the weekend still shears out before it can give us any rain. Then
GFS/ECMWF both begin to amplify pattern over the CONUS by the
middle of next week with a trough over the Rockies and ridge over
the Mississippi Valley on Wednesday.
A dry airmass and light winds/mainly clear skies should allow for
some excellent radiational cooling at night. Went a few degrees
below guidance for lows over the weekend into early next week.
Britt
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 553 AM CDT Fri Sep 20 2013
COLD FRONT MOVING THROUGH THE AREA WILL BE THE FOCUS OF THE
FORECAST. FRONT SHOULD BE THROUGH UIN AND COU IN A 12 - 13Z
TIMEFRAME. PRECIPITATION HAS MOVED WELL SOUTH OF THESE AREA SO
THEY LOOK TO STAY DRY. MDLS ARE TRYING TO HOLD PRECIP ALONG I-44
SOUTH UNTIL ABOUT MIDDAY. WITH THE UPPER TROF HANGING BACK THIS IS
CERTAINLY POSSIBLE. HOWEVER RADAR LOOPS SHOW A SHRINKING TREND AND
A DECENT PUSH TO THE SOUTHEAST ALONG THE BACK EDGE. THUS I WILL
KEEP MOST OF THE LINGERING LIGHT RAIN SOUTH AND EAST OF ANY
TERMINALS. OTHER ISSUE WILL BE IFR/MFVR CEILINGS BEHIND THE FRONT.
CURRENT OBSERVATION SHOW A MIXED BAD OF CLOUDS SO DON`T FEEL ANY
ONE DIRECTION WILL BE THE ANSWER. UIN LOOKS TO BE IFR FOR A COUPLE
OF HOURS AND COU MAY COME DOWN...BUT WILL NOT HOLD IT IN LONG.
Specifics for KSTL: FRONT SHOULD BE THROUGH ABOUT 15 - 16Z. WILL
KEEP SOME LIGHT RAIN IN...6SM UNTIL THEN...ALTHOUGH THAT MAY BE
TOO LONG. RADAR ECHOES CONTINUE TO SHRINK. SOME IFR CLOUDS IN THE
AREA BUT DO NOT EXPECT THEM TO HOLD LONG.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
326 AM CDT Fri Sep 20 2013
.SHORT TERM: (Through Tonight)
Issued at 326 AM CDT Fri Sep 20 2013
Main concern will be how quickly the rain will exit the area today.
Cold front currently extends from Kirksville to Sedalia to Nevada.
Ahead of it, there is a large band of rain with the leading edge
of the thunderstorms extending from just northeast of metro St.
Louis southwestward West Plains. This line should continue to
move east in the near term...though there will continue to be some
weakening in this line as the RAP shows the 925-850mb moisture
convergence diminishing. The cold front will continue to move
southeast today, clearing the CWA by 21Z. The main band of rain
with embedded thunderstorms will be found ahead of it, aided by
ascent from the front and the deep upper through moving across the
central CONUS. This is generally follows the latest runs of the
HRRR which shows rain slowly spreading southeast with time.
With clouds and rain today, temperatures will be much cooler than
yesterday. Some locations in south and east may not see much
diurnal recovery.
Britt
.LONG TERM: (Saturday through Wednesday)
Issued at 326 AM CDT Fri Sep 20 2013
Forecast remains dry in the long term. Strong subsidence sets in
the wake of the upper trough as upper ridge builds in over the
region by late Sunday. Deep trough that enters the West Coast over
the weekend still shears out before it can give us any rain. Then
GFS/ECMWF both begin to amplify pattern over the CONUS by the
middle of next week with a trough over the Rockies and ridge over
the Mississippi Valley on Wednesday.
A dry airmass and light winds/mainly clear skies should allow for
some excellent radiational cooling at night. Went a few degrees
below guidance for lows over the weekend into early next week.
Britt
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1136 PM CDT Thu Sep 19 2013
A line of thunderstorms stretching from near Chicago, Illinois
through Columbia, Missouri to northeast Oklahoma will continue to
steadily march east-southeast tonight. Expect MVFR or IFR ceilings
to develop in the wake of this convection and ahead of the cold
front that stretches from central Iowa through northwest Missouri.
Initial storms and outflow will switch wind to the northwest, but
real wind shift will come with the cold front Friday morning. Some
indication by model guidance that light rain may continue Friday
morning for locations along and south of Interstate 70. This is
reasonable given the position of the upper level trof to our west.
Finally VFR conditions and clearing skies are expected by Friday
evening as dry cool air filters into the region.
Specifics for KSTL:
Wind shift to the northwest will occur shortly with outflow
boundary. Trailing line of thunderstorms should reach the terminal
between 07Z and 09Z, with light rain continuing into the daylight
hours Friday morning. Have lowered ceiling to MVFR, but can`t rule
out IFR flight conditions similar to what KIRK is observing at
this time. Cold front should move through by afternoon with
improving conditions.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BUFFALO NY
801 AM EDT FRI SEP 20 2013
.SYNOPSIS...
HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL PROVIDE ANOTHER DAY
OF DRY WEATHER FOR MOST OF THE REGION TODAY WITH TEMPERATURES RISING
TO ABOVE NORMAL. RAIN IS EXPECTED TONIGHT INTO SATURDAY AS A COLD
FRONT MOVES EAST ACROSS THE GREAT LAKES. TEMPERATURES WILL FALL BACK
BELOW NORMAL WITH DRY CONDITIONS EXPECTED BEHIND THE COLD FRONT FOR
SUNDAY INTO MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL REMAIN ANCHORED OFF THE MID ATLANTIC COAST TODAY.
A STEADY INFLUX OF LOW LEVEL MOISTURE WILL PUSH NORTHWARD INTO
WESTERN NEW YORK ON THE WESTERN SIDE OF THE HIGH AS A WARM
FRONTAL BOUNDARY CURRENTLY STRETCHING ACROSS THE SOUTHERN GREAT
LAKES/OHIO VALLEY ADVANCES TOWARD THE REGION. UPSTREAM RADARS
SHOWING GOOD COVERAGE OF CONVECTION ASSOCIATED WITH THE WARM FRONT
BUT ALL SHORT TERM MODELS INCLUDING HRRR AND 00Z SPC SSEO RUN
DISSIPATE THIS ACTIVITY AS IT WORKS EASTWARD INTO THE RIDGE THIS
MORNING. THERE WILL BE SOME OPPORTUNITY FOR CONVECTIVE DEVELOPMENT
ACROSS FAR WESTERN NEW YORK THIS AFTERNOON AS ATMOSPHERE
DESTABILIZES...BUT FOR THE MOST PART THE DAY LOOKS DRY FOR A GOOD
PORTION OF THE AREA. A WARM DAY IN STORE WITH TEMPERATURES WITH
HIGHS IN THE UPPER 70S TO LOWER 80S...A SOLID 10 DEGREES ABOVE
NORMAL.
TONIGHT...UPPER TROUGH CURRENTLY OVER THE MANITOBA BORDER STRETCHING
DOWN THROUGH THE NORTHERN PLAINS WILL TRACK EAST AND INTO THE GREAT
LAKES. THIS WILL DRIVE A COLD FRONT TOWARD WESTERN NEW YORK LATE
TONIGHT. DEEP LAYER FORCING WILL ACCOMPANY THE FRONT...WITH PVA AND
RIGHT ENTRANCE REGION FORCING/UPPER DIFFLUENCE STACKED ABOVE THE
FRONT...GENERATING A WIDESPREAD COVERAGE OF SHOWERS AND
THUNDERSTORMS INTO WESTERN NEW YORK...ESPECIALLY AFTER 06Z. SEVERE
POTENTIAL LOOKS LIMITED WITH DIMINISHING INSTABILITY. HOWEVER WITH
THE APPROACH OF THE UPPER TROUGH...UNIDIRECTIONAL WIND PROFILES
DEVELOP WITH 0-6 KM BULK SHEAR VALUES INCREASING TO 30 TO 35
KNOTS...NOT COMPLETELY RULING OUT A FEW GUSTY THUNDERSTORMS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THE UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS STATES TODAY WILL
MOVE TO THE GREAT LAKES AND NORTHEASTERN STATES DURING THE WEEKEND.
THE TROUGH WILL PUSH A COLD FRONT EASTWARD ACROSS THE REGION LATE
FRIDAY NIGHT AND INTO CENTRAL NY BY LATE SATURDAY. ABUNDANT MOISTURE
WILL POOL ALONG AND AHEAD OF COLD FRONT...PROVIDED BY THE REMNANTS
OF EASTERN PACIFIC TROPICAL SYSTEMS...WITH A LINE OF THUNDERSTORMS
AND TRAILING STRATIFORM RAIN INTO SATURDAY MORNING AS THE FRONT
MOVES EAST. RAIN AMOUNTS WITH THIS SYSTEM MIGHT EXCEED AN INCH IN
SOME LOCATIONS.
REMAINING LOW LEVEL MOISTURE BEHIND THE FRONT WILL PRODUCE AREAS OF
DRIZZLE IN UPSLOPE REGIONS SATURDAY NIGHT AS AN INVERSION TRAPS
MOISTURE BELOW 800MB. HIGH PRESSURE BUILDING ACROSS REGION ON
SUNDAY WILL BRING A SLOW CLEARING TREND THROUGH THE DAY.
TEMPERATURES WILL BE THE MID 40S TO LOW 50S SATURDAY NIGHT AND THE
HIGHS ON SUNDAY WILL ONLY BE IN THE MID 50S TO AROUND 60 UNDER
COLDER NORTHWESTERLY FLOW. NEARLY CLEAR SKIES SUNDAY NIGHT WILL
YIELD A CHILLY NIGHT WITH VALLEY FOG FORMING.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE MOVES INTO THE LOWER GREAT LAKES REGION NEXT
WEEK...PROVIDING DRY WEATHER ACROSS THE REGION FOR MOST IF NOT ALL
OF NEXT WEEK. EXPECT TYPICAL EARLY FALL SEASON HIGHS AND LOWS WITH
ABUNDANT DAYTIME SUNSHINE...CLEAR SKIES OVERNIGHT AND PATCHY FOG IN
INLAND VALLEYS DURING THE EARLY MORNING HOURS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL MAINTAIN THROUGH
THE DAY TODAY. A COLD FRONT WILL PUSH EAST ACROSS THE REGION
DURING THE FIRST HALF OF SATURDAY. A MVFR LEVEL STRATOCU DECK
ACROSS SOUTHWESTERN NEW YORK WILL IMPROVE TO VFR BETWEEN 13Z AND
15Z. WIDESPREAD VFR CONDITIONS ARE THEN EXPECTED THE REMAINDER OF
THE DAY.
TONIGHT INTO SATURDAY...AN APPROACHING COLD FRONT WILL BRING
SHOWERS AND A FEW THUNDERSTORMS TO THE REGION...PRIMARILY AFTER 09Z
AS SOUTHWEST FLOW TRANSPORTS MOISTURE NORTHWARD. MVFR BECOMING
IFR WILL DEVELOP ACROSS THE WEST TOWARD MORNING WORKING EAST
THROUGH THE DAY.
OUTLOOK...
SATURDAY NIGHT...BECOMING VFR.
SUNDAY THROUGH TUESDAY...VFR.
&&
.MARINE...
HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL PROVIDE TRANQUIL
WEATHER THROUGH TODAY. EXPECT LIGHT WINDS AND MINIMAL WAVES. A COLD
FRONT WILL APPROACH THE LOWER GREAT LAKES TONIGHT INTO SATURDAY
WITH WAVES INCREASING ON THE EASTERN ENDS OF THE LAKES. SMALL CRAFT
CONDITIONS MAY BE REACHED ON THE EASTERN HALF OF LAKE ONTARIO
TONIGHT AS THE FRONT APPROACHES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TMA
NEAR TERM...TMA
SHORT TERM...WCH
LONG TERM...ZAFF
AVIATION...TMA
MARINE...TMA
AREA FORECAST DISCUSSION
NWS BUFFALO NY
411 AM EDT FRI SEP 20 2013
.SYNOPSIS...
HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL PROVIDE ANOTHER DAY
OF DRY WEATHER FOR MOST OF THE REGION TODAY WITH TEMPERATURES RISING
TO ABOVE NORMAL. RAIN IS EXPECTED TONIGHT INTO SATURDAY AS A COLD
FRONT MOVES EAST ACROSS THE GREAT LAKES. TEMPERATURES WILL FALL BACK
BELOW NORMAL WITH DRY CONDITIONS EXPECTED BEHIND THE COLD FRONT FOR
SUNDAY INTO MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL REMAIN ANCHORED OFF THE MID ATLANTIC COAST TODAY.
A STEADY INFLUX OF LOW LEVEL MOISTURE WILL PUSH NORTHWARD INTO
WESTERN NEW YORK ON THE WESTERN SIDE OF THE HIGH AS A WARM
FRONTAL BOUNDARY CURRENTLY STRETCHING ACROSS THE SOUTHERN GREAT
LAKES/OHIO VALLEY ADVANCES TOWARD THE REGION. UPSTREAM RADARS
SHOWING GOOD COVERAGE OF CONVECTION ASSOCIATED WITH THE WARM FRONT
BUT ALL SHORT TERM MODELS INCLUDING HRRR AND 00Z SPC SSEO RUN
DISSIPATE THIS ACTIVITY AS IT WORKS EASTWARD INTO THE RIDGE THIS
MORNING. THERE WILL BE SOME OPPORTUNITY FOR CONVECTIVE DEVELOPMENT
ACROSS FAR WESTERN NEW YORK THIS AFTERNOON AS ATMOSPHERE
DESTABILIZES...BUT FOR THE MOST PART THE DAY LOOKS DRY FOR A GOOD
PORTION OF THE AREA. A WARM DAY IN STORE WITH TEMPERATURES WITH
HIGHS IN THE UPPER 70S TO LOWER 80S...A SOLID 10 DEGREES ABOVE
NORMAL.
TONIGHT...UPPER TROUGH CURRENTLY OVER THE MANITOBA BORDER STRETCHING
DOWN THROUGH THE NORTHERN PLAINS WILL TRACK EAST AND INTO THE GREAT
LAKES. THIS WILL DRIVE A COLD FRONT TOWARD WESTERN NEW YORK LATE
TONIGHT. DEEP LAYER FORCING WILL ACCOMPANY THE FRONT...WITH PVA AND
RIGHT ENTRANCE REGION FORCING/UPPER DIFFLUENCE STACKED ABOVE THE
FRONT...GENERATING A WIDESPREAD COVERAGE OF SHOWERS AND
THUNDERSTORMS INTO WESTERN NEW YORK...ESPECIALLY AFTER 06Z. SEVERE
POTENTIAL LOOKS LIMITED WITH DIMINISHING INSTABILITY. HOWEVER WITH
THE APPROACH OF THE UPPER TROUGH...UNIDIRECTIONAL WIND PROFILES
DEVELOP WITH 0-6 KM BULK SHEAR VALUES INCREASING TO 30 TO 35
KNOTS...NOT COMPLETELY RULING OUT A FEW GUSTY THUNDERSTORMS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THE UPPER LEVEL TROUGH OVER THE NORTHERN PLAINS STATES TODAY WILL
MOVE TO THE GREAT LAKES AND NORTHEASTERN STATES DURING THE WEEKEND.
THE TROUGH WILL PUSH A COLD FRONT EASTWARD ACROSS THE REGION LATE
FRIDAY NIGHT AND INTO CENTRAL NY BY LATE SATURDAY. ABUNDANT MOISTURE
WILL POOL ALONG AND AHEAD OF COLD FRONT...PROVIDED BY THE REMNANTS
OF EASTERN PACIFIC TROPICAL SYSTEMS...WITH A LINE OF THUNDERSTORMS
AND TRAILING STRATIFORM RAIN INTO SATURDAY MORNING AS THE FRONT
MOVES EAST. RAIN AMOUNTS WITH THIS SYSTEM MIGHT EXCEED AN INCH IN
SOME LOCATIONS.
REMAINING LOW LEVEL MOISTURE BEHIND THE FRONT WILL PRODUCE AREAS OF
DRIZZLE IN UPSLOPE REGIONS SATURDAY NIGHT AS AN INVERSION TRAPS
MOISTURE BELOW 800MB. HIGH PRESSURE BUILDING ACROSS REGION ON
SUNDAY WILL BRING A SLOW CLEARING TREND THROUGH THE DAY.
TEMPERATURES WILL BE THE MID 40S TO LOW 50S SATURDAY NIGHT AND THE
HIGHS ON SUNDAY WILL ONLY BE IN THE MID 50S TO AROUND 60 UNDER
COLDER NORTHWESTERLY FLOW. NEARLY CLEAR SKIES SUNDAY NIGHT WILL
YIELD A CHILLY NIGHT WITH VALLEY FOG FORMING.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE MOVES INTO THE LOWER GREAT LAKES REGION NEXT
WEEK...PROVIDING DRY WEATHER ACROSS THE REGION FOR MOST IF NOT ALL
OF NEXT WEEK. EXPECT TYPICAL EARLY FALL SEASON HIGHS AND LOWS WITH
ABUNDANT DAYTIME SUNSHINE...CLEAR SKIES OVERNIGHT AND PATCHY FOG IN
INLAND VALLEYS DURING THE EARLY MORNING HOURS.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE OFF THE MID ATLANTIC COAST WILL KEEP FINE VFR
CONDITIONS IN PLACE THROUGH THE OVERNIGHT...WITH JUST THE POTENTIAL
FOR SOME VALLEY FOG/STRATUS FOR SITES SUCH AS KJHW AND KELZ.
FOR FRIDAY...WHILE VFR WEATHER WILL PREVAIL ACROSS THE REGION...
THERE WILL BE THE RISK FOR SOME MIDDAY AND AFTERNOON CONVECTION OVER
THE FAR WESTERN COUNTIES (WEST OF GEN VALLEY).
OUTLOOK...
FRIDAY NIGHT...MVFR WITH SHOWERS AND THUNDERSTORMS BECOMING LIKELY.
SATURDAY...MVFR WITH RAIN AND THUNDERSTORMS.
SUNDAY AND MONDAY...MAINLY VFR.
&&
.MARINE...
HIGH PRESSURE ALONG THE MID ATLANTIC COAST WILL PROVIDE TRANQUIL
WEATHER THROUGH TODAY. EXPECT LIGHT WINDS AND MINIMAL WAVES. A COLD
FRONT WILL APPROACH THE LOWER GREAT LAKES TONIGHT INTO SATURDAY
WITH WAVES INCREASING ON THE EASTERN ENDS OF THE LAKES. SMALL CRAFT
CONDITIONS MAY BE REACHED ON THE EASTERN HALF OF LAKE ONTARIO
TONIGHT AS THE FRONT APPROACHES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TMA
NEAR TERM...TMA
SHORT TERM...WCH
LONG TERM...ZAFF
AVIATION...RSH/TMA
MARINE...TMA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1001 PM EDT SAT SEP 21 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND CROSS THE
REGION SUNDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH EARLY NEXT
WEEK. LOW PRESSURE WILL PASS SOUTH OF THE REGION WEDNESDAY WITH HIGH
PRESSURE RETURNING LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 955 PM SATURDAY...LIGHT PRECIPITATION HAS REACHED THE
HIGHWAY 17 CORRIDOR AND FORECAST IS ON TRACK WITH POPS BECOMING
CATEGORICAL OVER THE ENTIRE CWA BY 06Z OR SO. A FEW EMBEDDED
HEAVIER SHOWERS DID PRODUCE SOME DAMAGING WIND GUSTS NEAR THE
VIRGINIA/NORTH CAROLINA BORDER EARLIER BUT THIS ACTIVITY IS
LIFTING WELL NORTH OF OUR CWA AND SHOULD POSE NO THREAT. IN
GENERAL...EXPECT MOSTLY LIGHT RAIN WITH AN OCCASIONAL EMBEDDED
HEAVIER SHOWERS THROUGH THE OVERNIGHT HOURS. NO CHANGES MADE TO
CURRENT FORECAST TEMPERATURES.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 300 PM SAT...MODELS INDICATE SLIGHTLY SLOWER FRONTAL
PROGRESSION WITH NAM AND ECMWF INDICATING STRONGER SFC WAVE ON SRN
END. HAVE ADJUSTED FCST SLIGHTLY TOWARD THIS SOLUTION WITH HIGHER
POPS LINGERING ALONG COAST THROUGH MORNING...DIMINISHING W TO E
DURING AFTN. MOS BLEND FOR TEMPS WITH PCPN AND CLOUD COVER EXPECTED
TO HOLD MAX TEMPS IN MID TO UPR 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
ANY LINGERING PRECIP WILL GRADUALLY BE MOVING OFF THE COAST SUNDAY
NIGHT, WITH COOLER/DRIER AIR FILTERING INTO THE REGION VIA SFC
HIGH PRES RIDGING SOUTH FROM THE GREAT LAKES AND DEVELOPING NW
FLOW ALOFT. LOWS WILL DIP INTO THE MID 50S INLAND BY EARLY MON
MORNING AND LOW TO MID 60S COAST UNDER GRADUALLY CLEARING SKIES.
PLEASANT WEATHER CONDITIONS WILL HIGHLIGHT THE EARLY WEEK PERIOD WITH
SFC HIGH AND UPPER RIDGE BUILDING OVER THE AREA. TEMPS WILL BE A
BIT BLO NORMAL WITH GOOD RADIATIONAL COOLING AT NIGHT, BUT WITH
LOTS OF SUNSHINE BOTH MONDAY AND TUESDAY
MODEL SOLUTIONS CONTINUE TO VARY WITH A SYSTEM (OR LACK THEREOF)
MOVING OFF THE SE COAST DURING MIDWEEK. WILL CONTINUE TO FOLLOW
WPC RECOMMENDATIONS FOR A BLEND OF ENSEMBLE MEANS WHICH MORE
CLOSELY FOLLOW THE DETERMINISTIC ECMWF SOLUTION, JUST NOT AS
AMPLIFIED. SO WITH THAT IN MIND WILL KEEP POPS AT SLIGHT TO LOW
THRU MIDWEEK AND FAVOR SOUTHERN AREAS FOR THE HIGHER PRECIP
CHANCES. CLOUD COVER SPREADING NORTH ON THE FRINGES OF THE
SOUTHERN SYSTEM WILL HELP HOLD HIGH TEMPS IN THE 70S ON
WEDNESDAY.
PRECIP CHANCES LINGER THRU WED NIGHT AND INTO EARLY THU ESPECIALLY
ALONG SE COASTAL AREAS. SHUD BEGIN TO SEE DECREASING CLOUDS THU
AFTN AS SFC LOW PRES MOVES WELL OFF THE SE COAST AND MID LEVEL
DRYING SWEEPS THRU THE FCST AREA. RIDGING AT THE SURFACE AND ALOFT
ENSURES DRY WEATHER RETURNING TO THE REGION LATE IN THE WEEK.
TEMPS WILL TREND BACK TO NEAR AND ABOVE NORMAL LEVELS INTO EARLY
NEXT WEEKEND.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 18Z SUNDAY/...
AS OF 645 PM SAT...WILL DELAY THE ONSET OF LOWER CEILINGS FOR A
FEW HOURS AS THE LEADING EDGE OF THE PRECIPITATION SHIELD JUST
REACHING OUR FAR WESTERN CWA. CEILINGS AND VSBYS WILL DROP TO MVFR
WITH OCCASIONAL IFR AFTER MIDNIGHT INTO THE EARLY MORNING HOURS ON
SUNDAY. CEILING HEIGHTS WILL REBOUND VERY SLOWLY TOMORROW AS THE
COLD FRONT PUSHES OFF THE COAST.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
POOR FLYING CONDITIONS SUNDAY EVENING WILL GRADUALLY IMPROVE THRU
EARLY MONDAY MORNING AS DRIER AIR WORKS INTO THE AREA. OTHER THAN
THE TYPICAL THREAT FOR SHALLOW EARLY MORNING FOG...GOOD FLYING
WEATHER EXPECTED MONDAY/TUESDAY WITH HIGH PRESSURE BUILDING INTO
THE AREA. WILL BEGIN TO SEE INCREASING CLOUDS, RAIN CHANCES AND
THREAT FOR SUB-VFR CONDITIONS WEDNESDAY INTO WED NIGHT AS LOW
PRESSURE MOVES SOUTH OF THE AREA. EXPECTED IMPROVING FLYING
CONDITIONS ON TUESDAY AS HIGH PRESSURE RETURNS.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 955 PM SAT...PER LATEST 3KM HRRR AND RUC MODELS...EXPECT THE
CURRENT SOUTHERLY WINDS AT 10 TO 15 KNOTS TO BECOME SW LATE
TONIGHT. SPEEDS MAY INCREASE TO 15 TO 20 KNOTS OVER THE SOUTHERN
WATERS AND SURFACE LOW TRACKS INLAND LATE TONIGHT. SEAS SHOULD
REMAIN RIGHT AROUND 3 FEET WITH 10 SECOND SWELL PERIODS. ADJUSTED
WINDS FOR SLIGHTLY SLOWER FRONTAL PASSAGE ON SUNDAY...AND MAINLY
LEANED TO GFS AS NAM AND ECMWF APPEAR OVERDONE WITH SFC WV
DEVELOPMENT ON SRN END OF FRONT. PRE- FRONTAL S-SW WINDS 15 KT OR
LESS WILL DEVELOP THIS EVENING...SHIFTING TO W AND NW SUNDAY.
PREVIOUS FCST IN GENERAL AGREEMENT WITH LATEST SWAN AND WW3...MAINLY
2-3 FT THROUGH TONIGHT...WITH SOME INCREASE TO 4 FT NRN PORTIONS SUN
AFTN.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
CAA SURGE WILL PUSH NORTH WINDS AND SEAS TO NEAR SMALL CRAFT
ADVISORY LEVELS SUNDAY NIGHT INTO EARLY MONDAY. WINDS WILL THEN
GRADUALLY DIMINISH AND VEER TO THE NE/E AND SEAS SLOWLY SUBSIDE AS
HIGH PRESSURE BUILDS INTO THE MARINE AREA FROM THE NORTH THRU
TUESDAY. WINDS WILL BACK AGAIN TO THE NE/N AND INCREASE AS LOW
PRESSURE PASSES TO THE SOUTH WED NIGHT AND THURSDAY BUT NOT
EXPECTING ANY FLAGS WILL BE NEEDED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...BTC
AVIATION...CTC/BM
MARINE...CTC/BTC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
649 PM EDT FRI SEP 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA WILL GIVER WAY TO LOW PRESSURE TONIGHT
AND SATURDAY WITH SURFACE FRONT EXPECTED TO CROSS THE AREA SATURDAY
NIGHT. HIGH PRESSURE WILL BUILD OVER THE AREA FOR THE FIRST PART OF
THE WEEK. A SYSTEM WILL APPROACH FROM THE SOUTH WEDNESDAY AND MOVE
EAST OF THE THE AREA THURSDAY WITH HIGH PRESSURE BUILDING BACK IN
BY THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 645 PM FRIDAY...PATCHY SHOWERS HAVE IMPACTED THE FAR INLAND
COUNTIES TODAY BUT HAVE GREATLY DECREASED IN COVERAGE OVER THE
PAST COUPLE OF HOURS. MOST OF THE HIGH RESOLUTION WRF MODELS ALONG
WITH THE NAM12 AND RAP INDICATE A LEAST SOME PATCHY SHOWERS
CONTINUING INTO THE OVERNIGHT HOURS...WITH COVERAGE INCREASING
AFTER MIDNIGHT AS FRONT APPROACHES FROM THE WEST. WILL KEEP SLIGHT
CHC POPS OVER THE FAR INLAND TIER OF COUNTIES THROUGH ABOUT
06Z...THE SPREAD TO THE HIGHWAY 17 CORRIDOR AFTER 06Z. NO REAL
CHANGES IN FORECAST TEMPERATURES OVERNIGHT AS TEMPS WILL MUCH
MILDER THAN RECENT NIGHTS AS THE LOW-LEVELS MOISTEN AND THE FLOW
BECOMES SE/S.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
AS OF 124 PM FRI...HIGH PRESSURE ALOFT WILL WEAKEN THROUGH THE DAY
ON SATURDAY AS FULL LATITUDE TROUGH APPROACHES FROM THE WEST. UPPER
LOW OFF THE COAST WILL BE ABSORBED BY THE APPROACHING SYSTEM.
SURFACE REFLECTION FRONT WILL APPROACH THE AREA DURING THE
DAY...WITH SURFACE FLOW BECOMING SOUTHWESTERLY AND PICKING UP IN
SPEED TO 10 TO 15 MPH. AS FRONT APPROACHES WITH WEAK UPPER LEVEL
FORCING...WILL HAVE SMALL BUT INCREASED POPS. HIGHEST CHANCES WILL
BE IN WESTERN SECTIONS DURING THE LATER AFTERNOON...BUT WILL KEEP
POPS AROUND 30 IN THOSE AREAS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
SHORT WAVE EMBEDDED IN THE DIGGING FULL LATITUDE TROF DEVELOPING
OVER THE EASTERN STATES WILL PASS THRU THE FORECAST AREA SAT
NIGHT. GIVEN THE GOOD MID LEVEL MOISTURE INFLOW FROM THE GULF
REGION AND SFC MOIST FLOW OFF THE ATLANTIC HAVE UPPED POPS TO
LIKELY SAT NIGHT. INSTABILITY WILL BE LIMITED DUE TO THE
UNFAVORABLE DIURNAL CYCLE BUT WILL HANG ONTO ISOLD TSTM MENTION
GIVEN THE MODEST SHEAR, MAINLY FOR SAT EVE AREAWIDE THEN SHIFTING
TO THE COAST AFTER MIDNIGHT. SHORTER RANGE MODELS ARE IN DECENT
AGREEMENT PUSHING THE SFC COLD FRONT THRU THE AREA OVERNIGHT AND
OFFSHORE BY DAYBREAK SUNDAY. RAINFALL TOTALS DO NOT LOOK TO BE
IMPRESSIVE GIVEN THE RELATIVELY FAST MOVING SYSTEM WITH GENERAL
ONE HALF INCH AMOUNTS EXPECTED AND LOCALLY HIGHER AMOUNTS.
SFC BNDRY SAGS SOUTH OF THE REGION ON SUNDAY. CUD BE SOME
LEFTOVER PRECIP ESP OVER SOUTHERN AREAS BUT MOST OF SUNDAY INTO
SUNDAY NIGHT SHUD BE DRY WITH GRADUALLY CLEARING AS HIGH PRESSURE
RIDGES IN FROM THE NW. BROAD EAST COAST TROF WILL PUSH OFFSHORE
EARLY NEXT WEEK AS SHORT WAVE RIDGE SLIDES EAST TO THE NORTHERN
MID ATLC STATES. SOUTHERN STREAM SYSTEM UNDERCUTS THE RIDGE OVER
THE GULF COAST AND SE STATES WHICH WILL THROW CLOUDS AND LOW
PRECIP CHANCES AS FAR NORTH AS EASTERN NC DURING MIDWEEK.
UPPER RIDGE BUILDS OVER SE STATES IN THE WAKE OF THE SOUTHERN
STREAM SYSTEM MOVING OFF THE COAST LATE IN THE WEEK...WITH A
RETURN TO MAINLY CLEAR SKIES...COOL NIGHTS AND MILD DAYS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /TONIGHT AND SATURDAY/...
AS OF 645 PM FRI...GIVEN SKIES THAT HAVE REMAINED RELATIVELY
CLEAR AT THE TAF SITES...AND WITH LOW-LEVEL FLOW BECOMING MORE
SE/S TOWARD MORNING...AM A BIT MORE CONCERNED ABOUT THE
DEVELOPMENT OF FOG AND STRATUS TOWARD MORNING AS ALL OF THE
NUMERICAL MOS GUIDANCE INDICATES LOW CEILINGS AND VSBYS AFTER 08Z
OR SO. WILL BE A BIT MORE CONSERVATIVE...BUT WILL INDICATE A
PERIOD OF MVFR VSBYS/CEILINGS TOWARD MORNING. GENERALLY VFR FOR
MOST OF SATURDAY AS PRECIPITATION SHOULD NOT BECOME MORE
WIDESPREAD UNTIL LATER IN THE DAY.
LONG TERM /SAT NIGHT THROUGH WEDNESDAY/...
SHOWERS/ISOLD TSTMS AHEAD OF A COLD FRONT SAT NIGHT WILL LIKELY
BRING PERIODS OF SUB-VFR CONDITIONS. GRADUAL IMPROVEMENT IN FLYING
CONDITIONS ON SUNDAY AS HIGH PRESSURE BUILDS IN FROM THE NORTH
THROUGH EARLY NEXT WEEK. FRINGE EFFECTS OF A SOUTHERN STREAM
SYSTEM MOVING OFF THE SE COAST WILL BRING CLOUDINESS AND PRECIP
CHANCES BACK INTO THE AREA TUE NIGHT AND WEDNESDAY WITH SUB-VFR
CONDITIONS POSSIBLE.
&&
.MARINE...
SHORT TERM /TONIGHT AND SATURDAY/... AS OF 650 PM FRI...NE/ENE WINDS
SHOULD GRADUALLY VEER TO A MORE SE/S DIRECTION TOWARD MORNING AS
AXIS OF HIGH PRESSURE RIDGE MOVES OFFSHORE AS A COLD FRONT
APPROACHES. WIND SPEEDS SHOULD BE 15 KNOT OR LESS WITH SEAS
GENERALLY 2 TO 4 FEET WITH LONG PERIOD 10 TO 11 SECOND SWELLS. AS
THE FRONT APPROACHES THE AREA SATURDAY...BRINGING WIND TO A
SOUTHERLY DIRECTION...AND INCREASING SPEEDS TO 10 TO 15 KNOTS AS
GRADIENT INCREASING AHEAD OF THE APPROACHING FRONT. SEAS WILL
REMAIN 2 TO 4 FEET THROUGH THE PERIOD.
LONG TERM /SAT NIGHT THROUGH WEDS/...
MODERATE SW FLOW AHEAD OF A COLD FRONT PASSAGE SAT NIGHT WILL
SHIFT WEST THEN NW AND DECREASING SLIGHTLY ON SUNDAY. THE MAIN
PUSH OF COLD AIR ADVECTION WILL MOVE DOWN THE NC COAST LATE SUNDAY
NIGHT/EARLY MONDAY WITH N/NE WINDS (AND SEAS) APPROACHING SMALL
CRAFT ADVISORY LEVELS. LIGHT TO MODERATE NE WINDS WILL CONTINUE
THRU THE EARLY PART OF THE WEEK THEN INCREASE SOMEWHAT AS LOW
PRESSURE PASSES OFF THE SE COAST DURING MIDWEEK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CGG
NEAR TERM...CTC
SHORT TERM...CGG
LONG TERM...BTC
AVIATION...CTC/BTC/BM
MARINE...CTC/BTC/CGG
AREA FORECAST DISCUSSION
NWS PORTLAND OR
902 AM PDT FRI SEP 20 2013
.SYNOPSIS... A PACIFIC FRONT WILL BRING DETERIORATING CONDITIONS TO
THE AREA TODAY. RAIN WILL SPREAD INTO THE COAST BY MIDDAY AND ACROSS
THE WILLAMETTE VALLEY BY THE MID TO LATE AFTERNOON HOURS. ADDITIONAL
RAIN SHOWERS WILL CONTINUE FRIDAY NIGHT INTO SATURDAY WITH PERHAPS A
FEW LIGHTNING STRIKES. A STRONGER FRONT WILL BRING WINDY CONDITIONS
TO THE COAST...BREEZY CONDITIONS INLAND...AND ANOTHER ROUND OF
WIDESPREAD RAIN TO THE AREA SUNDAY. COOL AND UNSETTLED WEATHER SHOULD
CONTINUE FOR THE FIRST HALF OF NEXT WEEK WITH PERIODS OF SHOWERS
BEFORE SOME DRYING FOR THE LATTER HALF OF NEXT WEEK.
&&
.UPDATE...SEVERAL WAVES ALONG THE FRONT OFFSHORE WHICH WILL SLOW THE
PROGRESS OF THE FRONT IN THE NORTH...WHILE ANOTHER WAVE IS NOTED
FURTHER SOUTH. HAVE SEEN LIGHTNING OFFSHORE FROM BROOKINGS IN
SOUTHERN OREGON WITH THIS SECONDARY WAVE...WHICH IS WHERE THE LATEST
HRRR SUGGESTS CONVECTIVE ACTIVITY WILL CONTINUE INLAND. MODELS ARE
SHOWING WEAK INSTABILITY ALONG THE ENTIRE FRONT EVEN UP NEAR
PORTLAND WITH HINTS OF CONVECTIVE ELEMENTS IN THE HRRR...SO CANNOT
RULE OUT AN ISOLATED STRIKE ANYWHERE FOR A BRIEF TIME RIGHT WITH THE
FRONTAL PASSAGE IN THE LATE AFTERNOON AND EARLY EVENING. /KMD
.SHORT TERM...INFRARED SATELLITE IMAGERY SHOWS WAVES OF SHOWERS
ROLLING NORTHWARD ALONG A FRONTAL BOUNDARY APPROXIMATELY 100-150
MILES OFF THE PACIFIC NORTHWEST COAST THIS MORNING. SUFFICIENTLY DEEP
INSTABILITY IN THE VICINITY OF THE FRONT HAS RESULTED IN A FEW
LIGHTNING STRIKES TOWARDS VANCOUVER ISLAND OVERNIGHT. KLGX DOPPLER
RADAR INDICATES A FEW LIGHT SHOWERS AHEAD OF THE MAIN FRONTAL BAND
MAY BRING LIGHT SPOTTY SHOWERS TO THE COAST THIS MORNING. HRRR AND A
LINEAR EXTRAPOLATION OF THE RADAR INDICATES THE STEADIER AND HEAVIER
RAIN WILL LIKELY HIT THE COAST DURING THE LATE MORNING HOURS AND
SPREAD INTO THE WILLAMETTE VALLEY DURING THE MID TO LATE AFTERNOON
HOURS. THERE IS SOME CONCERN THAT WE COULD SEE CONVECTION WITH THE
FRONT AS IT PUSHES INLAND LATE THIS AFTERNOON AND EARLY
EVENING...BUT FOR NOW KEPT THE THUNDER MENTION PRIMARILY LIMITED TO
THE COAST AND CENTRAL OREGON CASCADES.
A COLD UNSTABLE AIRMASS WILL SLOWLY WORK ITS WAY OVER THE AREA
TONIGHT INTO SATURDAY. THIS SHOULD RESULT IN PERIODS OF SUN BREAKS
BETWEEN SHOWERS SATURDAY WITH A FEW RUMBLES OF THUNDER POSSIBLE JUST
ABOUT ANYWHERE. SNOW LEVELS WILL LOWER TO NEAR 6-6.5KFT SATURDAY.
BRIEF SHORTWAVE RIDGING SATURDAY NIGHT SHOULD RESULT IN SHOWERS
DECREASING ACROSS THE AREA. HOWEVER...THE RESPITE WILL BE SHORT
LIVED AS THE NEXT STORM SYSTEM SPREADS WIDESPREAD RAIN FROM
NORTHWEST TO SOUTHEAST ACROSS THE AREA SUNDAY. IN ADDITION...A
STRONG FRONT WILL BRING WINDY CONDITIONS TO THE COAST AND BREEZY
CONDITIONS INLAND ON SUNDAY. THE NAM IS THE STRONGEST SOLUTION AT
THIS POINT...WITH THE GFS BACKING OFF JUST A BIT ON 925MB AND 850MB
WINDS FROM PREVIOUS MODEL RUNS SO CONFIDENCE IS NOT PARTICULARLY
HIGH A HIGH WIND PRODUCT WILL BE NEEDED FOR THE COAST.
NONETHELESS...WIND GUSTS OF AT LEAST 45 TO 55 MPH APPEAR TO BE A
SAFE BET FOR MANY LOCATIONS ALONG THE COAST.
ONSHORE FLOW WITH COOLING TEMPERATURES ALOFT SHOULD RESULT IN
ADDITIONAL ROUNDS OF SHOWERS MONDAY AND TUESDAY AS AN UPPER LEVEL
TROUGH DROPS INTO THE PACIFIC NORTHWEST. /NEUMAN
.LONG TERM...SUNDAY EVENING THROUGH THURSDAY...
EXPECT THE MAIN FRONTAL BAND TO SHIFT INLAND SUNDAY EVENING. THE
UPPER LOW ASSOCIATED WITH THIS FRONT WILL BEGIN THE EXTENDED PERIOD
OFF THE COAST OF CENTRAL B.C. THEN DIG SOUTH AND EAST AND WILL BE ON
TOP OF THE AREA TUESDAY NIGHT. WITH THE LOW TO THE NORTH WE WILL
MAINTAIN A GOOD BATCH OF ONSHORE FLOW THROUGH AT LEAST TUESDAY.
SEVERAL WAVES OF ENERGY WILL MIGRATE THROUGH THE AREA FOR PERIODS OF
SHOWERS...THOUGH EXPECT LITTLE IN THE WAY OF BREAKS IN ELEVATED
TERRAIN...AND NO OBVIOUS DRY PERIODS FOR THE LOWLANDS AS WELL.
TEMPERATURES WILL REMAIN BELOW NORMAL AND GENERALLY IN THE 60S FOR
THE LOWLANDS.
THE UPPER LOW WILL SHIFT SOUTH AND EAST OF THE AREA THROUGH THE DAY
ON WEDNESDAY. AN UPPER LEVEL RIDGE WILL BE OFFSHORE ON WEDNESDAY
EVENING AND ATTEMPT TO SLOWLY PUSH ONSHORE. THE FLOW TURNS NORTH TO
NORTHEASTERLY WHICH WILL ALLOW THE AREA TO DRY OUT THROUGH AT LEAST
FRIDAY WHILE ANOTHER FRONT ATTEMPTS TO SQUASH THE RIDGE OFFSHORE. A
RETROGRADING INLAND RIDGE MAY KEEP THIS AT BAY FOR NEXT WEEKEND.
EXPECT TEMPERATURES TO REBOUND TO AT LEAST THE LOWER 70S AND CLOSER
TO NORMAL WITH MORE IN THE WAY OF SUNSHINE AFTER MORNING FOG.
KMD/ROCKEY
&&
.AVIATION...MAINLY VFR CONDITIONS OVER THE REGION THIS MORNING.
CLOUDS WILL THICKEN AND LOWER THROUGHOUT THE DAY AS A FRONT
APPROACHES FROM THE WEST. AREAS OF MVFR CIGS ALONG THE COAST THIS
MORNING WILL EXPAND LATER TODAY. BUT INLAND VFR CONDITIONS ARE
LIKELY TO PERSIST INTO THE EVENING BEFORE AREAS OF MVFR CONDITIONS
DEVELOP AFTER 05Z.
KPDX AND APPROACHES...VFR EXPECTED THROUGH 05Z. CLOUDS WILL LOWER
THIS EVENING AS A FRONT MOVES IN...WITH A GOOD CHANCE FOR MVFR
CIGS AFTER 05Z.
&&
.MARINE...WIND FIELDS WITH THE FRONT MOVING IN THIS MORNING WERE
WEAKENING...AND AT THIS POINT IT APPEARS UNLIKELY TO SEE MORE THAN A
FEW GUSTS OVER THE SMALL CRAFT WIND CRITERIA. SEAS HOWEVER HAVE BEEN
PICKING UP QUICKLY EARLY THIS MORNING AS A WESTERLY SWELL ON THE
ORDER OF 10 TO 12 FT HAS MOVED IN. THE FRONT ITSELF...WITH SE
WINDS AHEAD OF IT AND SW WINDS BEHIND...IS EXPECTED TO REACH THE
COAST BETWEEN 11 AM AND 2 PM.
A STRONGER SYSTEM WILL REACH THE WATERS SUN...WITH WINDS LIKELY
TOPPING OUT IN THE GALE CATEGORY. WITH THE BIGGER WINDS COME THE
PROSPECTS FOR BIGGER SEAS...LIKELY TO BE ON THE ORDER OF 15 FT BY
MON.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 5 AM PDT
SATURDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
314 AM PDT FRI SEP 20 2013
.SYNOPSIS... A PACIFIC FRONT WILL BRING DETERIORATING CONDITIONS TO
THE AREA TODAY. RAIN WILL SPREAD INTO THE COAST BY MIDDAY AND ACROSS
THE WILLAMETTE VALLEY BY THE MID TO LATE AFTERNOON HOURS. ADDITIONAL
RAIN SHOWERS WILL CONTINUE FRIDAY NIGHT INTO SATURDAY WITH PERHAPS A
FEW LIGHTNING STRIKES. A STRONGER FRONT WILL BRING WINDY CONDITIONS
TO THE COAST...BREEZY CONDITIONS INLAND...AND ANOTHER ROUND OF
WIDESPREAD RAIN TO THE AREA SUNDAY. COOL AND UNSETTLED WEATHER SHOULD
CONTINUE FOR THE FIRST HALF OF NEXT WEEK WITH PERIODS OF SHOWERS
BEFORE SOME DRYING FOR THE LATTER HALF OF NEXT WEEK.
&&
.SHORT TERM...INFRARED SATELLITE IMAGERY SHOWS WAVES OF SHOWERS
ROLLING NORTHWARD ALONG A FRONTAL BOUNDARY APPROXIMATELY 100-150
MILES OFF THE PACIFIC NORTHWEST COAST THIS MORNING. SUFFICIENTLY DEEP
INSTABILITY IN THE VICINITY OF THE FRONT HAS RESULTED IN A FEW
LIGHTNING STRIKES TOWARDS VANCOUVER ISLAND OVERNIGHT. KLGX DOPPLER
RADAR INDICATES A FEW LIGHT SHOWERS AHEAD OF THE MAIN FRONTAL BAND
MAY BRING LIGHT SPOTTY SHOWERS TO THE COAST THIS MORNING. HRRR AND A
LINEAR EXTRAPOLATION OF THE RADAR INDICATES THE STEADIER AND HEAVIER
RAIN WILL LIKELY HIT THE COAST DURING THE LATE MORNING HOURS AND
SPREAD INTO THE WILLAMETTE VALLEY DURING THE MID TO LATE AFTERNOON
HOURS. THERE IS SOME CONCERN THAT WE COULD SEE CONVECTION WITH THE
FRONT AS IT PUSHES INLAND LATE THIS AFTERNOON AND EARLY
EVENING...BUT FOR NOW KEPT THE THUNDER MENTION PRIMARILY LIMITED TO
THE COAST AND CENTRAL OREGON CASCADES.
A COLD UNSTABLE AIRMASS WILL SLOWLY WORK ITS WAY OVER THE AREA
TONIGHT INTO SATURDAY. THIS SHOULD RESULT IN PERIODS OF SUN BREAKS
BETWEEN SHOWERS SATURDAY WITH A FEW RUMBLES OF THUNDER POSSIBLE JUST
ABOUT ANYWHERE. SNOW LEVELS WILL LOWER TO NEAR 6-6.5KFT SATURDAY.
BRIEF SHORTWAVE RIDGING SATURDAY NIGHT SHOULD RESULT IN SHOWERS
DECREASING ACROSS THE AREA. HOWEVER...THE RESPITE WILL BE SHORT
LIVED AS THE NEXT STORM SYSTEM SPREADS WIDESPREAD RAIN FROM
NORTHWEST TO SOUTHEAST ACROSS THE AREA SUNDAY. IN ADDITION...A
STRONG FRONT WILL BRING WINDY CONDITIONS TO THE COAST AND BREEZY
CONDITIONS INLAND ON SUNDAY. THE NAM IS THE STRONGEST SOLUTION AT THIS
POINT...WITH THE GFS BACKING OFF JUST A BIT ON 925MB AND 850MB WINDS
FROM PREVIOUS MODEL RUNS SO CONFIDENCE IS NOT PARTICULARLY HIGH A HIGH
WIND PRODUCT WILL BE NEEDED FOR THE COAST. NONETHELESS...WIND GUSTS
OF AT LEAST 45 TO 55 MPH APPEAR TO BE A SAFE BET FOR MANY LOCATIONS
ALONG THE COAST.
ONSHORE FLOW WITH COOLING TEMPERATURES ALOFT SHOULD RESULT IN
ADDITIONAL ROUNDS OF SHOWERS MONDAY AND TUESDAY AS AN UPPER LEVEL
TROUGH DROPS INTO THE PACIFIC NORTHWEST. /NEUMAN
.LONG TERM...SUNDAY EVENING THROUGH THURSDAY...
EXPECT THE MAIN FRONTAL BAND TO SHIFT INLAND SUNDAY EVENING. THE
UPPER LOW ASSOCIATED WITH THIS FRONT WILL BEGIN THE EXTENDED PERIOD
OFF THE COAST OF CENTRAL B.C. THEN DIG SOUTH AND EAST AND WILL BE ON
TOP OF THE AREA TUESDAY NIGHT. WITH THE LOW TO THE NORTH WE WILL
MAINTAIN A GOOD BATCH OF ONSHORE FLOW THROUGH AT LEAST TUESDAY.
SEVERAL WAVES OF ENERGY WILL MIGRATE THROUGH THE AREA FOR PERIODS OF
SHOWERS...THOUGH EXPECT LITTLE IN THE WAY OF BREAKS IN ELEVATED
TERRAIN...AND NO OBVIOUS DRY PERIODS FOR THE LOWLANDS AS WELL.
TEMPERATURES WILL REMAIN BELOW NORMAL AND GENERALLY IN THE 60S FOR
THE LOWLANDS.
THE UPPER LOW WILL SHIFT SOUTH AND EAST OF THE AREA THROUGH THE DAY
ON WEDNESDAY. AN UPPER LEVEL RIDGE WILL BE OFFSHORE ON WEDNESDAY
EVENING AND ATTEMPT TO SLOWLY PUSH ONSHORE. THE FLOW TURNS NORTH TO
NORTHEASTERLY WHICH WILL ALLOW THE AREA TO DRY OUT THROUGH AT LEAST
FRIDAY WHILE ANOTHER FRONT ATTEMPTS TO SQUASH THE RIDGE OFFSHORE. A
RETROGRADING INLAND RIDGE MAY KEEP THIS AT BAY FOR NEXT WEEKEND.
EXPECT TEMPERATURES TO REBOUND TO AT LEAST THE LOWER 70S AND CLOSER
TO NORMAL WITH MORE IN THE WAY OF SUNSHINE AFTER MORNING FOG.
KMD/ROCKEY
&&
.AVIATION...MAINLY VFR CONDITIONS OVER THE REGION EARLY THIS
MORNING. THERE IS A CHANCE FOR PATCHY IFR CONDITIONS IN FOG THROUGH
15Z THIS MORNING ALONG THE COAST...THEN CLOUDS ARE EXPECTED TO
SPREAD OVER THE REGION. MVFR CIGS ARE LIKELY TO FORM ALONG THE COAST
THIS MORNING BETWEEN 12Z AND 18Z AHEAD OF A SLOW APPROACHING
FRONT...BUT INLAND VFR CONDITIONS ARE LIKELY TO PERSIST PAST 00Z.
KPDX AND APPROACHES...VFR EXPECTED THROUGH 00Z. CLOUDS WILL LOWER
THIS EVENING AS A FRONT MOVES IN...WITH A GOOD CHANCE FOR MVFR CIGS
AFTER RAINS MOVE IN AFTER 00Z.
&&
.MARINE...WIND FIELDS WITH THE FRONT MOVING IN THIS MORNING WERE
WEAKENING...AND AT THIS POINT IT APPEARS UNLIKELY TO SEE MORE THAN A
FEW GUSTS OVER THE SMALL CRAFT WIND CRITERIA. SEAS HOWEVER HAVE BEEN
PICKING UP QUICKLY EARLY THIS MORNING AS A WESTERLY SWELL ON THE
ORDER OF 10 TO 12 FT HAS MOVED IN. SEAS IN EXCESS OF 10 FT CAN BE
EXPECTED TO REACH THE S WA AND N OREGON COAST AROUND 3 AM...PROBABLY
A COUPLE HOURS LATER ON THE CENTRAL OREGON COAST. THE FRONT
ITSELF...WITH SE WINDS AHEAD OF IT A SW WINDS BEHIND...IS EXPECTED
TO REACH THE COAST BETWEEN 11 AM AND 2 PM.
A STRONGER SYSTEM WILL REACH THE WATERS SUN...WITH WINDS LIKELY
TOPPING OUT IN THE GALE CATEGORY. WITH THE BIGGER WINDS COME THE
PROSPECTS FOR BIGGER SEAS...LIKELY TO BE ON THE ORDER OF 15 FT BY
MON.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 AM PDT EARLY THIS
MORNING FOR WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SAT
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
5 AM PDT SAT.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
701 AM EDT FRI SEP 20 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED ALONG THE MID ATLANTIC COAST WILL MAINTAIN
ITS GRIP ON THE REGION TODAY. A COLD FRONT WILL PUSH EAST ACROSS
THE STATE SATURDAY. AN OMEGA BLOCK AND ASSOCIATED HIGH PRES WILL
LIKELY BE PARKED OVR THE AREA THROUGH ALL OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLEAR SKIES...A CALM WIND AND INCREASING LOW LVL MOISTURE HAS
RESULTED WIDESPREAD VALLEY FOG EARLY THIS AM. MODIS 11-3.7UM SATL
IMAGERY SHOWS THE MOST EXTENSIVE LOW STRATUS/FOG HAS FORMED ACROSS THE
NORTH CENTRAL MTNS. LEANING TOWARD AN SPS RATHER THAN AN ADVISORY
TO COVER LOCALLY DENSE FOG THIS AM.
VALLEY FOG SHOULD BURN OFF BY 13Z-14Z ACROSS MOST OF THE AREA
BASED ON 3KM HRRR SFC RH AND WHAT OCCURRED YESTERDAY. HOWEVER...STRATUS
DECK...WHICH HAS WORKED INTO SOMERSET AND WARREN COUNTIES...MAY
TAKE UNTIL ALMOST NOON TO LIFT/BREAK UP INTO SCT-BKN CU FIELD.
HIGHER PWAT AIR ON WESTERN PERIPHERY OF SFC HIGH WILL BE ACROSS
WESTERN PA AND LEAD TO A MIX OF SUN AND CU THIS AFTN...WHILE DRIER
AND MAINLY SUNNY SKIES PREVAIL ACROSS THE EASTERN COUNTIES. CAN/T
RULE OUT A VERY ISOLD LATE DAY SHRA/TSRA IN THE MORE HUMID AND
MARGINALLY UNSTABLE AIR MASS ACROSS THE W MTNS. HOWEVER...UPPER
LVL RIDGING AND ASSOC WARM MID LVL TEMPS SHOULD ENSURE A DRY DAY
FOR THE VAST MAJORITY OF THE AREA.
GEFS 925TEMPS BTWN 16C-21C FROM SE TO NW SHOULD SUPPORT HIGH TEMPS
THIS AFTN IN THE M/U70S...WITH THE WARMEST TEMPS RELATIVE TO
NORMAL ACROSS THE W MTNS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SHORT RANGE MDLS IN AGREEMENT WITH RESPECT TO TIMING OF COLD
FRONT....WHICH SHOULD ENTER THE NW MTNS LATE SAT AM AND EXIT
EASTERN PA DURING THE EVENING HRS. DEEP SOUTHERLY FLOW AND ASSOC
ATMOSPHERIC RIVER OF ANOMALOUS PWATS WILL PRECEDE APPROACHING COLD
FRONT...BRINGING A DECENT RAINFALL TO MOST OF CENTRAL PA. LATEST
SREF AND GEFS OUTPUT INDICATE A LIKELIHOOD OF RAIN TOTALS NR 1
INCH OVR MUCH OF THE AREA WITH LOCAL TOTALS ARND 2 INCHES MOST
LIKELY ACROSS THE EASTERN HALF OF THE STATE...DUE TO POSSIBLE WEAK
WAVE AND SLOWING OF FRONT SAT EVENING. MDL CAPES ARE UNIMPRESSIVE...THE
RESULT OF ABUNDANT PRE-FRONTAL CLOUD COVER. HOWEVER...WILL MAINTAIN
SLGHT CHC OF EMBEDDED TSRA.
GEFS AND SREF OUTPUT BOTH SUPPORT POPS NR 100 PCT ACROSS THE
ENTIRE AREA SATURDAY. CURRENT MDL TIMING SUGGESTS THE EASTERN
COUNTIES MAY REMAIN DRY UNTIL THE AFTN HRS...WHILE RAIN IS LIKELY
TO BEGIN BEFORE DAWN ACROSS THE NW MTNS. BACK EDGE OF THE RAIN
SHOULD ARRIVE OVR THE W MTNS ARND 21Z AND THE EASTERN COUNTIES BY
ARND MIDNIGHT.
CLOUD COVER AND RAINFALL WILL LIKELY HOLD TEMPS IN THE M/U60S SAT
ACROSS THE ALLEGHENY PLATEAU...WHILE THE SUSQ VALLEY IS LIKELY TO
GET INTO THE L/70S BEFORE THE RAIN STARTS IN THE AFTN.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER LVL TROF AND ASSOC COLD TEMPS ALOFT WILL PASS THRU PA ON
SUNDAY...RESULTING IN A GOOD DEAL OF DIURNAL CU. CAN/T RULE OUT A
FEW SPRINKLES ACROSS THE N MTNS. HOWEVER...LOW PWAT AIR MASS IS
UNLIKELY TO PRODUCE MEASURABLE RAIN IN MANY SPOTS. ENS MEAN
925TEMPS ARE SUPPORTIVE OF HIGHS FROM JUST THE U50S ACROSS THE W
MTNS...TO THE U60S IN THE SUSQ VALLEY. A RATHER TIGHT PRES
GRADIENT BTWN DEPARTING CDFRONT AND HIGH PRES OVR THE WESTERN
LAKES SHOULD RESULT IN A FAIRLY ACTIVE NW WIND ON SUNDAY...ADDING
TO THE FALL-LIKE FEEL.
FAIRLY GOOD AGREEMENT AMONG MED RANGE GUIDANCE FOR NEXT
WEEK...MOST OF WHICH INDICATE PA WILL BE UNDER RIDGE PORTION OF
OMEGA BLOCK...RESULTING IN AN EXTENDED PERIOD OF FAIR WEATHER.
GEFS 925/850 TEMPS INDICATE DAYTIME TEMPS WILL BE NEAR TO A BIT
ABOVE NORMAL. HOWEVER...DRY AIR AND PROXIMITY OF SFC HIGH WILL
LIKELY PRODUCE SOME COOL MORNINGS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE CENTERED ALONG THE MID ATLANTIC COAST WILL MAINTAIN
ITS GRIP ON THE REGION TODAY. A COLD FRONT WILL PUSH EAST ACROSS
THE STATE SATURDAY.
WIDESPREAD IFR FOG ACROSS THE NORTH/WEST WITH MORE VARIABLE
CONDITIONS ELSEWHERE AT SUNRISE. RAPID IMPROVEMENT EXPECTED IN THE
EAST...BUT AN MVFR LEVEL STRATOCU DECK EDGING IN FROM THE WEST WILL
BRING MORE GRADUAL IMPROVEMENT TO WESTERN TAFS. BUT ULTIMATELY...
BY MID MORNING /14-15Z/ VFR CONDITIONS EXPECTED TO BECOME
WIDESPREAD AND CONTINUE THROUGH THE REMAINDER OF THE DAY AND INTO
THIS EVENING. SURFACE WINDS WILL BE LIGHT FROM THE SE/S. ANY
AFTERNOON CONVECTIVE ACTIVITY WILL REMAIN WEST OF CWA.
TONIGHT INTO SATURDAY...THE FOCUS TURNS TO AN APPROACHING COLD
FRONT. AS SW FLOW INCREASES /WITH INCREASED LOW LEVEL MOISTURE
TRANSPORT/...LOWER CIGS /MVFR BECOMING IFR/ WILL DEVELOP ACROSS
THE WEST LATE THIS EVENING AND SPREAD INTO EASTERN SECTIONS
THROUGH SUNRISE SAT. THOUGH SOME SHOWERS WORK INTO NW MTNS
LATE...MAINLY LIGHT SHOWERS OR AREAS OF DRIZZLE POSS AFTER 08Z
ELSEWHERE. SATURDAY LOOKS TO BRING POOR FLYING CONDITIONS AS AREA
OF RAIN WITH ISOLATED TSTMS IMPACTS THE REGION...KEEPING CIGS IFR
MUCH OF THE DAY INTO THE EVENING.
OUTLOOK...
SAT-SAT NIGHT...COLD FRONT CROSSES REGION. RAIN AND ISO TSTMS WILL
BRING RESTRICTIONS AREA-WIDE.
SUN...MVFR CONTINUES IN SCT SHRA/AREAS DZ...ESP IN THE MORNING
ACROSS THE NRN MTNS...AND SE PA AIRFIELDS. IMPROVING CONDITIONS LATE.
SUN NIGHT...SCT RESTRICTIONS DUE TO FOG.
MON AND TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ005-006-
010>012-017>019-025>028-037-041-042-045-046-049>053.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
540 AM EDT FRI SEP 20 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED ALONG THE MID ATLANTIC COAST WILL MAINTAIN
ITS GRIP ON THE REGION TODAY. A COLD FRONT WILL PUSH EAST ACROSS
THE STATE SATURDAY. AN OMEGA BLOCK AND ASSOCIATED HIGH PRES WILL
LIKELY BE PARKED OVR THE AREA THROUGH ALL OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLEAR SKIES...A CALM WIND AND INCREASING LOW LVL MOISTURE HAS
RESULTED WIDESPREAD VALLEY FOG EARLY THIS AM. MODIS 11-3.7UM SATL
IMAGERY SHOWS THE MOST EXTENSIVE LOW STRATUS/FOG HAS FORMED ACROSS THE
NORTH CENTRAL MTNS. LEANING TOWARD AN SPS RATHER THAN AN ADVISORY
TO COVER LOCALLY DENSE FOG THIS AM.
VALLEY FOG SHOULD BURN OFF BY 13Z-14Z ACROSS MOST OF THE AREA
BASED ON 3KM HRRR SFC RH AND WHAT OCCURRED YESTERDAY. HOWEVER...STRATUS
DECK...WHICH HAS WORKED INTO SOMERSET AND WARREN COUNTIES...MAY
TAKE UNTIL ALMOST NOON TO LIFT/BREAK UP INTO SCT-BKN CU FIELD.
HIGHER PWAT AIR ON WESTERN PERIPHERY OF SFC HIGH WILL BE ACROSS
WESTERN PA AND LEAD TO A MIX OF SUN AND CU THIS AFTN...WHILE DRIER
AND MAINLY SUNNY SKIES PREVAIL ACROSS THE EASTERN COUNTIES. CAN/T
RULE OUT A VERY ISOLD LATE DAY SHRA/TSRA IN THE MORE HUMID AND
MARGINALLY UNSTABLE AIR MASS ACROSS THE W MTNS. HOWEVER...UPPER
LVL RIDGING AND ASSOC WARM MID LVL TEMPS SHOULD ENSURE A DRY DAY
FOR THE VAST MAJORITY OF THE AREA.
GEFS 925TEMPS BTWN 16C-21C FROM SE TO NW SHOULD SUPPORT HIGH TEMPS
THIS AFTN IN THE M/U70S...WITH THE WARMEST TEMPS RELATIVE TO
NORMAL ACROSS THE W MTNS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SHORT RANGE MDLS IN AGREEMENT WITH RESPECT TO TIMING OF COLD
FRONT....WHICH SHOULD ENTER THE NW MTNS LATE SAT AM AND EXIT
EASTERN PA DURING THE EVENING HRS. DEEP SOUTHERLY FLOW AND ASSOC
ATMOSPHERIC RIVER OF ANOMALOUS PWATS WILL PRECEDE APPROACHING COLD
FRONT...BRINGING A DECENT RAINFALL TO MOST OF CENTRAL PA. LATEST
SREF AND GEFS OUTPUT INDICATE A LIKELIHOOD OF RAIN TOTALS NR 1
INCH OVR MUCH OF THE AREA WITH LOCAL TOTALS ARND 2 INCHES MOST
LIKELY ACROSS THE EASTERN HALF OF THE STATE...DUE TO POSSIBLE WEAK
WAVE AND SLOWING OF FRONT SAT EVENING. MDL CAPES ARE UNIMPRESSIVE...THE
RESULT OF ABUNDANT PRE-FRONTAL CLOUD COVER. HOWEVER...WILL MAINTAIN
SLGHT CHC OF EMBEDDED TSRA.
GEFS AND SREF OUTPUT BOTH SUPPORT POPS NR 100 PCT ACROSS THE
ENTIRE AREA SATURDAY. CURRENT MDL TIMING SUGGESTS THE EASTERN
COUNTIES MAY REMAIN DRY UNTIL THE AFTN HRS...WHILE RAIN IS LIKELY
TO BEGIN BEFORE DAWN ACROSS THE NW MTNS. BACK EDGE OF THE RAIN
SHOULD ARRIVE OVR THE W MTNS ARND 21Z AND THE EASTERN COUNTIES BY
ARND MIDNIGHT.
CLOUD COVER AND RAINFALL WILL LIKELY HOLD TEMPS IN THE M/U60S SAT
ACROSS THE ALLEGHENY PLATEAU...WHILE THE SUSQ VALLEY IS LIKELY TO
GET INTO THE L/70S BEFORE THE RAIN STARTS IN THE AFTN.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER LVL TROF AND ASSOC COLD TEMPS ALOFT WILL PASS THRU PA ON
SUNDAY...RESULTING IN A GOOD DEAL OF DIURNAL CU. CAN/T RULE OUT A
FEW SPRINKLES ACROSS THE N MTNS. HOWEVER...LOW PWAT AIR MASS IS
UNLIKELY TO PRODUCE MEASURABLE RAIN IN MANY SPOTS. ENS MEAN
925TEMPS ARE SUPPORTIVE OF HIGHS FROM JUST THE U50S ACROSS THE W
MTNS...TO THE U60S IN THE SUSQ VALLEY. A RATHER TIGHT PRES
GRADIENT BTWN DEPARTING CDFRONT AND HIGH PRES OVR THE WESTERN
LAKES SHOULD RESULT IN A FAIRLY ACTIVE NW WIND ON SUNDAY...ADDING
TO THE FALL-LIKE FEEL.
FAIRLY GOOD AGREEMENT AMONG MED RANGE GUIDANCE FOR NEXT
WEEK...MOST OF WHICH INDICATE PA WILL BE UNDER RIDGE PORTION OF
OMEGA BLOCK...RESULTING IN AN EXTENDED PERIOD OF FAIR WEATHER.
GEFS 925/850 TEMPS INDICATE DAYTIME TEMPS WILL BE NEAR TO A BIT
ABOVE NORMAL. HOWEVER...DRY AIR AND PROXIMITY OF SFC HIGH WILL
LIKELY PRODUCE SOME COOL MORNINGS.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE DEPARTING TO THE EAST HAS BROUGHT LIGHT SOUTHERLY
FLOW TO CENTRAL PA...GRADUALLY INCREASING LOW LEVEL MOISTURE WITH
DEWPOINTS NOW MAINLY IN THE 50S. WITH TEMPS COOLING TO NEAR THESE
DEWPOINTS...AREAS OF FOG HAVE FORMED WITH SOME AREAS /ESP IN THE
NORTHWEST MTNS/ DROPPING TO VLIFR WITH CONDITIONS ELSEWHERE QUITE
VARIABLE. ALL TAF SITES...IF IT HASN/T BEGUN ALREADY...SHOULD
EVENTUALLY SEE RESTRICTIONS DEVELOP THAT WILL LINGER THROUGH
AROUND 14Z. RESTRICTIONS WILL LINGER THE LONGEST IN THE WEST WHERE
A LOW CLOUD DECK IS SPREADING OVER TOP OF THE FOG.
CONDITIONS WILL SLOWLY IMPROVE THROUGH MID MORNING...WITH CIGS
AND VSBYS RETURNING TO THE VFR RANGE FOR ALL BY LATE MORNING.
VFR CONDITIONS WILL THEN CONTINUE THROUGH EARLY FRIDAY NIGHT.
AN APPROACHING COLD FRONT WILL USHER IN LOWER CIGS FROM WEST TO
EAST LATE FRI NIGHT INTO SATURDAY MORNING...WITH FREQUENT SHOWERS
AND POSSIBLE THUNDERSTORMS MOVING INTO THE FAR WEST AFTER 09Z.
OUTLOOK...
SAT-SAT NIGHT...COLD FRONT CROSSES REGION. RAIN AND SCT TSTMS WILL
BRING RESTRICTIONS AREA-WIDE.
SUN...MVFR CONTINUES IN SCT SHRA/TSRA...ESP IN THE MORNING ACROSS
THE NRN MTNS...AND SE PA AIRFIELDS.
MON AND TUE...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1224 PM CDT FRI SEP 20 2013
.UPDATE...
SEE THE UPDATED AVIATION DISCUSSION BELOW.
ADJUSTED CLOUD COVER THIS MORNING. LATEST SATELLITE IMAGERY SHOWS
A SWATH OF STRATUS OVER THE EASTERN CWA. STILL EXPECT THIS TO
CLEAR OUT BY EARLY AFTERNOON. LOWERED TEMPERATURES TONIGHT A FEW
DEGREES ACROSS THE JAMES RIVER VALLEY AND BORDERING COUNTIES SINCE
RETURN FLOW LOOKS LIKE IT WILL BE DELAYED. WILL LIKELY NEED A FROST
ADVISORY OVER PARTS OF THE AREA TONIGHT BUT WILL WAIT FOR 12Z
MODELS BEFORE DETERMINING EXACT AREA OF CONCERN.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SUNDAY
UPPER TROUGH AXIS IS CENTERED OVER THE DAKOTAS EARLY THIS MORNING
WITH A SMALLER INDIVIDUAL SHORTWAVE/VORT MAX SPINNING ACROSS
NORTHEAST SD. ISOLATED SPRINKLES/LIGHT SHOWERS HAVE BEEN OCCURRING
OVER THE PAST SEVERAL HOURS IN ASSOCIATION WITH THIS SMALLER VORT
MAX. HRRR PICKING UP ON THIS SOMEWHAT AND SHOWS THIS ACTIVITY
MOVING OUT OF THE AREA LATER THIS MORNING AS THE SHORTWAVE EXITS.
PLENTY OF STRATUS CLOUDS WITH THIS WAVE AS WELL. SOUNDINGS ACROSS
THE CWA SUGGEST MORE SUN THAN CLOUDS ACROSS THE WESTERN CWA
THROUGH THE DAY...BUT ACROSS THE EAST...STRATUS WILL TAKE SOME
TIME TO EXIT. AND WHATEVER STRATUS DOES EXIT OR DISSIPATE WILL
LIKELY BE FILLED BY CUMULUS DEVELOPMENT BY LATE MORNING OR EARLY
AFTERNOON. TEMPS WILL BE RATHER COOL ACROSS THE EASTERN CWA TODAY
WHERE TEMPS ALOFT ARE COLDEST. HIGHS IN THE 60S CAN BE EXPECTED
HERE.
SURFACE HIGH PRESSURE CENTERS ITSELF OVER THE REGION TONIGHT INTO
SATURDAY MORNING. THIS IS A COOL AIR MASS MOVING INTO THE AREA SO
WITH CLEARING SKIES AND LIGHT WINDS OVERNIGHT...LOOKING AT A
CHILLY START TO THE MORNING ON SATURDAY. MORNING LOWS IN THE 30S
ARE FORECAST FOR MOST OF THE EASTERN CWA...WITH THE JAMES VALLEY
LIKELY FALLING INTO THE MID 30S.
WARM AIR ADVECTION RAMPS BACK UP AGAIN SATURDAY INTO SUNDAY...WITH
WARMING TEMPERATURES AND INCREASING SOUTHEAST WINDS. BREEZY/WINDY
CONDITIONS LOOK LIKELY ON SUNDAY AS THE PRESSURE GRADIENT ACROSS
THE CWA BECOMES RATHER TIGHT.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
THE LONG TERM SHOULD BE FAIRLY ACTIVE ACCORDING TO THE LATEST
MODELS. A SOMEWHAT PROGRESSIVE MID LEVEL FLOW IS ANTICIPATED WITH
ONE DECENT S/W TROF MOVING THROUGH SUNDAY NIGHT AND MONDAY. THIS
SHOULD BRING RAIN/THUNDER TO MUCH OF THE CWA...ALTHOUGH MOST
MODELS ARE MORE BULLISH WITH AMOUNTS OVER THE WESTERN CWA VS THE
EAST. THEN A FAIRLY DEEP TROF DIGS INTO THE WESTERN CONUS SETTING
UP SOUTHWEST FLOW ALOFT FOR THE LATTER PART OF NEXT WEEK. A
FRONTAL BOUNDARY WILL BE PARKED ACROSS THE AREA. RAIN CHANCES ARE
EXPECTED MAINLY BEHIND THE FRONT THROUGH THE PERIOD. THE MODELS DO
HAVE SOME DIFFERENCES ON THE STRENGTH OF S/W ENERGY AND SFC WAVES
RIDING THE FRONT...BUT AT THAT TIME RANGE THIS IS EXPECTED. OVERALL
TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
STRATUS CONTINUES TO SLOWLY DRIFT EAST AND ERODE THIS AFTERNOON.
KATY IS THE ONLY REMAINING SITE WITH MVFR CIGS...BUT IS EXPECTED
TO CLEAR IN THE NEXT HOUR OR TWO. OTHERWISE...VFR CONDITIONS WILL
PREVAIL. A HIGH PRESSURE RIDGE WILL MOVE ACROSS THE REGION
TONIGHT...SO WEST TO NORTHWEST WINDS WILL GRADUALLY DISSIPATE
UNDERNEATH THE RIDGE...AND THEN WILL SWITCH TO THE SOUTHEAST
BEHIND THE RIDGE SATURDAY MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...TMT
LONG TERM...TDK
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1033 AM CDT FRI SEP 20 2013
.UPDATE...
ADJUSTED CLOUD COVER THIS MORNING. LATEST SATELLITE IMAGERY SHOWS
A SWATH OF STRATUS OVER THE EASTERN CWA. STILL EXPECT THIS TO
CLEAR OUT BY EARLY AFTERNOON. LOWERED TEMPERATURES TONIGHT A FEW
DEGREES ACROSS THE JAMES RIVER VALLEY AND BORDERING COUNTIES SINCE
RETURN FLOW LOOKS LIKE IT WILL BE DELAYED. WILL LIKELY NEED A FROST
ADVISORY OVER PARTS OF THE AREA TONIGHT BUT WILL WAIT FOR 12Z
MODELS BEFORE DETERMINING EXACT AREA OF CONCERN.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SUNDAY
UPPER TROUGH AXIS IS CENTERED OVER THE DAKOTAS EARLY THIS MORNING
WITH A SMALLER INDIVIDUAL SHORTWAVE/VORT MAX SPINNING ACROSS
NORTHEAST SD. ISOLATED SPRINKLES/LIGHT SHOWERS HAVE BEEN OCCURRING
OVER THE PAST SEVERAL HOURS IN ASSOCIATION WITH THIS SMALLER VORT
MAX. HRRR PICKING UP ON THIS SOMEWHAT AND SHOWS THIS ACTIVITY
MOVING OUT OF THE AREA LATER THIS MORNING AS THE SHORTWAVE EXITS.
PLENTY OF STRATUS CLOUDS WITH THIS WAVE AS WELL. SOUNDINGS ACROSS
THE CWA SUGGEST MORE SUN THAN CLOUDS ACROSS THE WESTERN CWA
THROUGH THE DAY...BUT ACROSS THE EAST...STRATUS WILL TAKE SOME
TIME TO EXIT. AND WHATEVER STRATUS DOES EXIT OR DISSIPATE WILL
LIKELY BE FILLED BY CUMULUS DEVELOPMENT BY LATE MORNING OR EARLY
AFTERNOON. TEMPS WILL BE RATHER COOL ACROSS THE EASTERN CWA TODAY
WHERE TEMPS ALOFT ARE COLDEST. HIGHS IN THE 60S CAN BE EXPECTED
HERE.
SURFACE HIGH PRESSURE CENTERS ITSELF OVER THE REGION TONIGHT INTO
SATURDAY MORNING. THIS IS A COOL AIR MASS MOVING INTO THE AREA SO
WITH CLEARING SKIES AND LIGHT WINDS OVERNIGHT...LOOKING AT A
CHILLY START TO THE MORNING ON SATURDAY. MORNING LOWS IN THE 30S
ARE FORECAST FOR MOST OF THE EASTERN CWA...WITH THE JAMES VALLEY
LIKELY FALLING INTO THE MID 30S.
WARM AIR ADVECTION RAMPS BACK UP AGAIN SATURDAY INTO SUNDAY...WITH
WARMING TEMPERATURES AND INCREASING SOUTHEAST WINDS. BREEZY/WINDY
CONDITIONS LOOK LIKELY ON SUNDAY AS THE PRESSURE GRADIENT ACROSS
THE CWA BECOMES RATHER TIGHT.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
THE LONG TERM SHOULD BE FAIRLY ACTIVE ACCORDING TO THE LATEST
MODELS. A SOMEWHAT PROGRESSIVE MID LEVEL FLOW IS ANTICIPATED WITH
ONE DECENT S/W TROF MOVING THROUGH SUNDAY NIGHT AND MONDAY. THIS
SHOULD BRING RAIN/THUNDER TO MUCH OF THE CWA...ALTHOUGH MOST
MODELS ARE MORE BULLISH WITH AMOUNTS OVER THE WESTERN CWA VS THE
EAST. THEN A FAIRLY DEEP TROF DIGS INTO THE WESTERN CONUS SETTING
UP SOUTHWEST FLOW ALOFT FOR THE LATTER PART OF NEXT WEEK. A
FRONTAL BOUNDARY WILL BE PARKED ACROSS THE AREA. RAIN CHANCES ARE
EXPECTED MAINLY BEHIND THE FRONT THROUGH THE PERIOD. THE MODELS DO
HAVE SOME DIFFERENCES ON THE STRENGTH OF S/W ENERGY AND SFC WAVES
RIDING THE FRONT...BUT AT THAT TIME RANGE THIS IS EXPECTED. OVERALL
TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MVFR CIGS AND PATCHY DRIZZLE OVER THE EASTERN DAKOTAS WILL
DISSIPATE OR MOVE OFF TO THE EAST BEFORE NOON...LEAVING VFR
CONDITIONS REGION WIDE.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...TMT
LONG TERM...TDK
AVIATION...WISE
WEATHER.GOV/ABERDEEN
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SUNDAY
UPPER TROUGH AXIS IS CENTERED OVER THE DAKOTAS EARLY THIS MORNING
WITH A SMALLER INDIVIDUAL SHORTWAVE/VORT MAX SPINNING ACROSS
NORTHEAST SD. ISOLATED SPRINKLES/LIGHT SHOWERS HAVE BEEN OCCURRING
OVER THE PAST SEVERAL HOURS IN ASSOCIATION WITH THIS SMALLER VORT
MAX. HRRR PICKING UP ON THIS SOMEWHAT AND SHOWS THIS ACTIVITY
MOVING OUT OF THE AREA LATER THIS MORNING AS THE SHORTWAVE EXITS.
PLENTY OF STRATUS CLOUDS WITH THIS WAVE AS WELL. SOUNDINGS ACROSS
THE CWA SUGGEST MORE SUN THAN CLOUDS ACROSS THE WESTERN CWA
THROUGH THE DAY...BUT ACROSS THE EAST...STRATUS WILL TAKE SOME
TIME TO EXIT. AND WHATEVER STRATUS DOES EXIT OR DISSIPATE WILL
LIKELY BE FILLED BY CUMULUS DEVELOPMENT BY LATE MORNING OR EARLY
AFTERNOON. TEMPS WILL BE RATHER COOL ACROSS THE EASTERN CWA TODAY
WHERE TEMPS ALOFT ARE COLDEST. HIGHS IN THE 60S CAN BE EXPECTED
HERE.
SURFACE HIGH PRESSURE CENTERS ITSELF OVER THE REGION TONIGHT INTO
SATURDAY MORNING. THIS IS A COOL AIR MASS MOVING INTO THE AREA SO
WITH CLEARING SKIES AND LIGHT WINDS OVERNIGHT...LOOKING AT A
CHILLY START TO THE MORNING ON SATURDAY. MORNING LOWS IN THE 30S
ARE FORECAST FOR MOST OF THE EASTERN CWA...WITH THE JAMES VALLEY
LIKELY FALLING INTO THE MID 30S.
WARM AIR ADVECTION RAMPS BACK UP AGAIN SATURDAY INTO SUNDAY...WITH
WARMING TEMPERATURES AND INCREASING SOUTHEAST WINDS. BREEZY/WINDY
CONDITIONS LOOK LIKELY ON SUNDAY AS THE PRESSURE GRADIENT ACROSS
THE CWA BECOMES RATHER TIGHT.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
THE LONG TERM SHOULD BE FAIRLY ACTIVE ACCORDING TO THE LATEST
MODELS. A SOMEWHAT PROGRESSIVE MID LEVEL FLOW IS ANTICIPATED WITH
ONE DECENT S/W TROF MOVING THROUGH SUNDAY NIGHT AND MONDAY. THIS
SHOULD BRING RAIN/THUNDER TO MUCH OF THE CWA...ALTHOUGH MOST
MODELS ARE MORE BULLISH WITH AMOUNTS OVER THE WESTERN CWA VS THE
EAST. THEN A FAIRLY DEEP TROF DIGS INTO THE WESTERN CONUS SETTING
UP SOUTHWEST FLOW ALOFT FOR THE LATTER PART OF NEXT WEEK. A
FRONTAL BOUNDARY WILL BE PARKED ACROSS THE AREA. RAIN CHANCES ARE
EXPECTED MAINLY BEHIND THE FRONT THROUGH THE PERIOD. THE MODELS DO
HAVE SOME DIFFERENCES ON THE STRENGTH OF S/W ENERGY AND SFC WAVES
RIDING THE FRONT...BUT AT THAT TIME RANGE THIS IS EXPECTED. OVERALL
TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MVFR CIGS AND PATCHY DRIZZLE OVER THE EASTERN DAKOTAS WILL
DISSIPATE OR MOVE OFF TO THE EAST BEFORE NOON...LEAVING VFR
CONDITIONS REGION WIDE.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...TDK
SHORT TERM...TMT
LONG TERM...TDK
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
353 AM CDT FRI SEP 20 2013
.SHORT TERM...TODAY THROUGH SUNDAY
UPPER TROUGH AXIS IS CENTERED OVER THE DAKOTAS EARLY THIS MORNING
WITH A SMALLER INDIVIDUAL SHORTWAVE/VORT MAX SPINNING ACROSS
NORTHEAST SD. ISOLATED SPRINKLES/LIGHT SHOWERS HAVE BEEN OCCURRING
OVER THE PAST SEVERAL HOURS IN ASSOCIATION WITH THIS SMALLER VORT
MAX. HRRR PICKING UP ON THIS SOMEWHAT AND SHOWS THIS ACTIVITY
MOVING OUT OF THE AREA LATER THIS MORNING AS THE SHORTWAVE EXITS.
PLENTY OF STRATUS CLOUDS WITH THIS WAVE AS WELL. SOUNDINGS ACROSS
THE CWA SUGGEST MORE SUN THAN CLOUDS ACROSS THE WESTERN CWA
THROUGH THE DAY...BUT ACROSS THE EAST...STRATUS WILL TAKE SOME
TIME TO EXIT. AND WHATEVER STRATUS DOES EXIT OR DISSIPATE WILL
LIKELY BE FILLED BY CUMULUS DEVELOPMENT BY LATE MORNING OR EARLY
AFTERNOON. TEMPS WILL BE RATHER COOL ACROSS THE EASTERN CWA TODAY
WHERE TEMPS ALOFT ARE COLDEST. HIGHS IN THE 60S CAN BE EXPECTED
HERE.
SURFACE HIGH PRESSURE CENTERS ITSELF OVER THE REGION TONIGHT INTO
SATURDAY MORNING. THIS IS A COOL AIR MASS MOVING INTO THE AREA SO
WITH CLEARING SKIES AND LIGHT WINDS OVERNIGHT...LOOKING AT A
CHILLY START TO THE MORNING ON SATURDAY. MORNING LOWS IN THE 30S
ARE FORECAST FOR MOST OF THE EASTERN CWA...WITH THE JAMES VALLEY
LIKELY FALLING INTO THE MID 30S.
WARM AIR ADVECTION RAMPS BACK UP AGAIN SATURDAY INTO SUNDAY...WITH
WARMING TEMPERATURES AND INCREASING SOUTHEAST WINDS. BREEZY/WINDY
CONDITIONS LOOK LIKELY ON SUNDAY AS THE PRESSURE GRADIENT ACROSS
THE CWA BECOMES RATHER TIGHT.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
THE LONG TERM SHOULD BE FAIRLY ACTIVE ACCORDING TO THE LATEST
MODELS. A SOMEWHAT PROGRESSIVE MID LEVEL FLOW IS ANTICIPATED WITH
ONE DECENT S/W TROF MOVING THROUGH SUNDAY NIGHT AND MONDAY. THIS
SHOULD BRING RAIN/THUNDER TO MUCH OF THE CWA...ALTHOUGH MOST
MODELS ARE MORE BULLISH WITH AMOUNTS OVER THE WESTERN CWA VS THE
EAST. THEN A FAIRLY DEEP TROF DIGS INTO THE WESTERN CONUS SETTING
UP SOUTHWEST FLOW ALOFT FOR THE LATTER PART OF NEXT WEEK. A
FRONTAL BOUNDARY WILL BE PARKED ACROSS THE AREA. RAIN CHANCES ARE
EXPECTED MAINLY BEHIND THE FRONT THROUGH THE PERIOD. THE MODELS DO
HAVE SOME DIFFERENCES ON THE STRENGTH OF S/W ENERGY AND SFC WAVES
RIDING THE FRONT...BUT AT THAT TIME RANGE THIS IS EXPECTED.
OVERALL TEMPERATURES WILL BE ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
LOW VFR TO MVFR CLOUDS WILL RESIDE ACROSS THE REGION FOR A FEW
MORE HOURS EARLY THIS MORNING...BEFORE SKIES CLEAR OFF. A FEW RAIN
SHOWERS ARE NOTED DEVELOPING MAINLY OVER SOUTHERN/SERN NORTH
DAKOTA SLIDING DOWN INTO THE AREA...SO HAVE ADDED A VICINITY
SHOWER MENTION TO THE KABR AND KATY TERMINALS FOR A FEW HOURS
EARLY THIS MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...TDK
AVIATION...TDK
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1244 PM CDT FRI SEP 20 2013
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1002 AM CDT FRI SEP 20 2013/
DISCUSSION...14Z SURFACE ANALYSIS PLACES A COLD FRONT FROM HUDSON
BAY BACK THROUGH EAST CENTRAL MISSOURI...ARKANSAS...WITH AN
EMBEDDED SURFACE LOW LOCATED OVER NORTHEAST TEXAS. TEMPERATURES AS
OF 9 AM CDT ARE IN THE 70S AT MOST LOCATIONS.
REGIONAL WSR-88D RADAR TRENDS INDICATE THE LEADING EDGE OF SHOWERS
AND THUNDERSTORMS ARE ALREADY ALONG AND WEST OF THE MISSISSIPPI
RIVER. SHORT TERM MODELS INCLUDING THE 3KM HRRR INDICATE A
POTENTIAL FOR RAIN ENDING EARLIER TONIGHT ALONG AND WEST OF THE
MISSISSIPPI RIVER. WILL MAKE ADJUSTMENTS TO AFTERNOON RAIN
CHANCES BASED ON CURRENT TRENDS AND CONSIDER TRIMMING CHANCES BACK
TONIGHT ACROSS THE ABOVE MENTIONED AREA AFTER THE 12Z GFS ARRIVES.
NOT ANTICIPATING ANY STRONG TO SEVERE THUNDERSTORM POTENTIAL AT
THIS TIME. HOWEVER...SUFFICIENT FORCING...PRECIPITABLE WATER VALUES
ABOVE 2 INCHES AND A SLOW MOVING FRONT STILL INDICATE A POTENTIAL
FOR HEAVY RAINFALL ACROSS THE MID SOUTH THROUGH TONIGHT. NOT
PLANNING ON ISSUING A FLASH FLOOD WATCH AT THIS TIME AS FLASH
FLOOD GUIDANCE VALUES STILL REMAIN HIGH DUE TO THE RECENT DRY
WEATHER AND ANTICIPATING AN AVERAGE OF RAINFALL UP TO 1-2 INCHES.
WILL MAKE ADJUSTMENTS TO ALL OTHER ELEMENTS AS NEEDED TO ACCOUNT
FOR SHORT TERM TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 624 AM CDT FRI SEP 20 2013/
UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 434 AM CDT FRI SEP 20 2013/
DISCUSSION...
CURRENTLY...A SIGNIFICANT MID LEVEL TROF IS PUSHING INTO THE UPPER
MS VALLEY WITH AN ASSOCD COLD FRONT STRETCHING FROM NEAR CHICAGO
SOUTHWEST INTO OKLAHOMA. ANOTHER PIECE OF UPPER LEVEL ENERGY IS
PUSHING FROM MEXICO INTO TEXAS WHICH IS HELPING TO FUNNEL DEEP
MOISTURE NORTHEASTWARD ALONG THE FRONT. RAIN WILL START PUSHING
INTO THE MIDSOUTH AT SUNRISE. TEMPS ARE VERY MILD ACROSS THE AREA
UNDER HIGH CLOUDS AND SOUTHERLY FLOW...IN THE UPPER 60S TO MID
70S.
TODAY THROUGH TONIGHT...THE MID LEVEL TROF ASSOCD WITH THE
NORTHERN BRANCH OF THE JET WILL PHASE WITH THE SOUTHERN STREAM
ENERGY COMING OUT OF TEXAS TO PRODUCE A HEAVY RAIN EVENT ACROSS
THE MIDSOUTH. DEEP MOISTURE WILL FLOW NORTHEASTWARD ALONG THE
SURFACE FRONT THAT WILL PUSH ACROSS THE AREA TODAY AND TONIGHT.
MODELS HAVE PRECIP WATER VALUES CLIMBING ABOVE 2 INCHES ALONG AND
AHEAD OF THE FRONT. MEANWHILE A WEAK SURFACE LOW WILL DEVELOP ALONG
THE FRONT AS IT PUSHES THROUGH THE MIDSOUTH. MODELS ARE INDICATING VERY
STRONG LIFT INVOF THE FRONT AS WELL. AS A RESULT EXPECT A WIDESPREAD
HEAVY RAINFALL OF 2 INCHES TO PERHAPS AS MUCH AS 4 INCHES LOCALLY
ACROSS THE AREA. DUE TO THE RECENT DRY SPELL RIVER LEVELS ARE LOW
AND FLASH FLOOD GUIDANCE VALUES ARE MAXED OUT SO WILL HOLD OFF ON
A FLASH FLOOD WATCH. WILL MENTION LOW LYING/LOCALIZED FLOODING IN
THE HWO. MARGINAL INSTABILITY COMBINED WITH WEAK SHEAR WILL KEEP
THE SEVERE WEATHER THREAT LOW. TEMPS WILL BE COOLER EVERYWHERE
EXCEPT NE MS WHERE RAIN WILL HOLD OFF FOR MUCH OF THE DAY AND
TEMPS WILL APPROACH 90. RAIN WILL BEGIN TO TAPER OFF FROM THE NW
LATER TONIGHT AS THE FRONT...MOISTURE AND LIFT PUSH EAST.
SATURDAY THROUGH MONDAY...NAM AND GFS PUSH THE FRONT THROUGH A FEW
HOURS QUICKER THAN THE ECMWF. AS A RESULT THE ECMWF HAS QUITE A
BIT MORE PRECIP OVER NE MS SATURDAY AM. TOOK A COMPROMISE
SOLUTION. OTHERWISE EXPECT CLEARING SKIES AND COOLER TEMPS UNDER
NORTHERLY WINDS. EXPECT BELOW NORMAL TEMPS FROM SATURDAY THROUGH
SUNDAY NIGHT WITH HIGHS IN THE UPPER 70S EACH DAY AND LOWS DEEP
INTO THE 50S EACH NIGHT. TEMPS WILL BEGIN TO WARM TOWARD
SEASONABLE LEVELS ON MONDAY AS HIGH PRESSURE RETREATS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...PERFORMED MAJOR SURGERY ON
THIS PART OF THE FORECAST. THE OPERATIONAL GFS AND ECMWF BOTH PUSH
A MID LEVEL TROF THROUGH THE REGION THAT PICKS UP A GOOD DEAL OF
MOISTURE FROM THE GULF AND SPREADS RAIN INTO THE MIDSOUTH MONDAY
NIGHT THROUGH TUESDAY NIGHT. GIVEN THE AGREEMENT BETWEEN THE TWO
MODELS AND THE CONFIRMATION FROM THE GFS ENSEMBLES IT IS HARD TO
IGNORE THIS FEATURE. ADDED SLIGHT CHC/CHC POPS DURING THIS PERIOD
FOR A START THOUGH THESE MAY NEED TO BE INCREASED. THIS FEATURE
WILL ALSO KEEP HIGH TEMPS DOWN A FEW DEGREES FROM THE PREVIOUS
FORECAST.
WEDNESDAY AND THURSDAY...UPPER LEVEL RIDGING WILL PUSH INTO THE
MIDSOUTH FROM THE WEST AND TEMPS WILL CLIMB BACK ABOVE NORMAL WITH
LITTLE RAIN.
SJM
&&
.AVIATION...RAIN WILL PREVAIL AT ALL SITES FOR THE MAJORITY OF
THIS TAF CYCLE AS A COLD FRONT SLOWLY MOVES ACROSS THE MIDSOUTH.
VIS WILL LIKELY VARY BETWEEN 2SM AND 5SM AS HEAVIER SHOWERS MOVE
ACROSS THE AREA. WILL KEEP 3-4 SM IN FOR MOST OF THE PERIOD.
REMOVED THE TSRA AT ALL SITES. WE STILL MAY SEE A FEW
STRIKES...BUT DO NOT THINK COVERAGE WILL BE SIGNIFICANT ENOUGH FOR
EVEN TEMPO THUNDER. CIGS WILL BE VARIABLE AS WELL ESPECIALLY AS
THE FRONT PASSES. HOWEVER MOST SITES WILL SEE GRADUAL REDUCTION IN
CIGS TO IFR LEVELS THIS AFTERNOON AND TONIGHT...THEN POSSIBLE SOME
IMPROVEMENT BEHIND THE FRONT. WINDS WILL BE SOUTHERLY...SHIFTING
FROM THE NORTH BETWEEN 6 AND 10 KTS BEHIND THE FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 81 63 79 58 / 100 100 10 0
MKL 82 62 77 50 / 80 100 10 10
JBR 79 59 77 52 / 100 50 10 0
TUP 86 67 79 56 / 60 100 40 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1002 AM CDT FRI SEP 20 2013
.DISCUSSION...14Z SURFACE ANALYSIS PLACES A COLD FRONT FROM HUDSON
BAY BACK THROUGH EAST CENTRAL MISSOURI...ARKANSAS...WITH AN
EMBEDDED SURFACE LOW LOCATED OVER NORTHEAST TEXAS. TEMPERATURES AS
OF 9 AM CDT ARE IN THE 70S AT MOST LOCATIONS.
REGIONAL WSR-88D RADAR TRENDS INDICATE THE LEADING EDGE OF SHOWERS
AND THUNDERSTORMS ARE ALREADY ALONG AND WEST OF THE MISSISSIPPI
RIVER. SHORT TERM MODELS INCLUDING THE 3KM HRRR INDICATE A
POTENTIAL FOR RAIN ENDING EARLIER TONIGHT ALONG AND WEST OF THE
MISSISSIPPI RIVER. WILL MAKE ADJUSTMENTS TO AFTERNOON RAIN
CHANCES BASED ON CURRENT TRENDS AND CONSIDER TRIMMING CHANCES BACK
TONIGHT ACROSS THE ABOVE MENTIONED AREA AFTER THE 12Z GFS ARRIVES.
NOT ANTICIPATING ANY STRONG TO SEVERE THUNDERSTORM POTENTIAL AT
THIS TIME. HOWEVER...SUFFICIENT FORCING...PRECIPITABLE WATER VALUES
ABOVE 2 INCHES AND A SLOW MOVING FRONT STILL INDICATE A POTENTIAL
FOR HEAVY RAINFALL ACROSS THE MID SOUTH THROUGH TONIGHT. NOT
PLANNING ON ISSUING A FLASH FLOOD WATCH AT THIS TIME AS FLASH
FLOOD GUIDANCE VALUES STILL REMAIN HIGH DUE TO THE RECENT DRY
WEATHER AND ANTICIPATING AN AVERAGE OF RAINFALL UP TO 1-2 INCHES.
WILL MAKE ADJUSTMENTS TO ALL OTHER ELEMENTS AS NEEDED TO ACCOUNT
FOR SHORT TERM TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 624 AM CDT FRI SEP 20 2013/
UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 434 AM CDT FRI SEP 20 2013/
DISCUSSION...
CURRENTLY...A SIGNIFICANT MID LEVEL TROF IS PUSHING INTO THE UPPER
MS VALLEY WITH AN ASSOCD COLD FRONT STRETCHING FROM NEAR CHICAGO
SOUTHWEST INTO OKLAHOMA. ANOTHER PIECE OF UPPER LEVEL ENERGY IS
PUSHING FROM MEXICO INTO TEXAS WHICH IS HELPING TO FUNNEL DEEP
MOISTURE NORTHEASTWARD ALONG THE FRONT. RAIN WILL START PUSHING
INTO THE MIDSOUTH AT SUNRISE. TEMPS ARE VERY MILD ACROSS THE AREA
UNDER HIGH CLOUDS AND SOUTHERLY FLOW...IN THE UPPER 60S TO MID
70S.
TODAY THROUGH TONIGHT...THE MID LEVEL TROF ASSOCD WITH THE
NORTHERN BRANCH OF THE JET WILL PHASE WITH THE SOUTHERN STREAM
ENERGY COMING OUT OF TEXAS TO PRODUCE A HEAVY RAIN EVENT ACROSS
THE MIDSOUTH. DEEP MOISTURE WILL FLOW NORTHEASTWARD ALONG THE
SURFACE FRONT THAT WILL PUSH ACROSS THE AREA TODAY AND TONIGHT.
MODELS HAVE PRECIP WATER VALUES CLIMBING ABOVE 2 INCHES ALONG AND
AHEAD OF THE FRONT. MEANWHILE A WEAK SURFACE LOW WILL DEVELOP ALONG
THE FRONT AS IT PUSHES THROUGH THE MIDSOUTH. MODELS ARE INDICATING VERY
STRONG LIFT INVOF THE FRONT AS WELL. AS A RESULT EXPECT A WIDESPREAD
HEAVY RAINFALL OF 2 INCHES TO PERHAPS AS MUCH AS 4 INCHES LOCALLY
ACROSS THE AREA. DUE TO THE RECENT DRY SPELL RIVER LEVELS ARE LOW
AND FLASH FLOOD GUIDANCE VALUES ARE MAXED OUT SO WILL HOLD OFF ON
A FLASH FLOOD WATCH. WILL MENTION LOW LYING/LOCALIZED FLOODING IN
THE HWO. MARGINAL INSTABILITY COMBINED WITH WEAK SHEAR WILL KEEP
THE SEVERE WEATHER THREAT LOW. TEMPS WILL BE COOLER EVERYWHERE
EXCEPT NE MS WHERE RAIN WILL HOLD OFF FOR MUCH OF THE DAY AND
TEMPS WILL APPROACH 90. RAIN WILL BEGIN TO TAPER OFF FROM THE NW
LATER TONIGHT AS THE FRONT...MOISTURE AND LIFT PUSH EAST.
SATURDAY THROUGH MONDAY...NAM AND GFS PUSH THE FRONT THROUGH A FEW
HOURS QUICKER THAN THE ECMWF. AS A RESULT THE ECMWF HAS QUITE A
BIT MORE PRECIP OVER NE MS SATURDAY AM. TOOK A COMPROMISE
SOLUTION. OTHERWISE EXPECT CLEARING SKIES AND COOLER TEMPS UNDER
NORTHERLY WINDS. EXPECT BELOW NORMAL TEMPS FROM SATURDAY THROUGH
SUNDAY NIGHT WITH HIGHS IN THE UPPER 70S EACH DAY AND LOWS DEEP
INTO THE 50S EACH NIGHT. TEMPS WILL BEGIN TO WARM TOWARD
SEASONABLE LEVELS ON MONDAY AS HIGH PRESSURE RETREATS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...PERFORMED MAJOR SURGERY ON
THIS PART OF THE FORECAST. THE OPERATIONAL GFS AND ECMWF BOTH PUSH
A MID LEVEL TROF THROUGH THE REGION THAT PICKS UP A GOOD DEAL OF
MOISTURE FROM THE GULF AND SPREADS RAIN INTO THE MIDSOUTH MONDAY
NIGHT THROUGH TUESDAY NIGHT. GIVEN THE AGREEMENT BETWEEN THE TWO
MODELS AND THE CONFIRMATION FROM THE GFS ENSEMBLES IT IS HARD TO
IGNORE THIS FEATURE. ADDED SLIGHT CHC/CHC POPS DURING THIS PERIOD
FOR A START THOUGH THESE MAY NEED TO BE INCREASED. THIS FEATURE
WILL ALSO KEEP HIGH TEMPS DOWN A FEW DEGREES FROM THE PREVIOUS
FORECAST.
WEDNESDAY AND THURSDAY...UPPER LEVEL RIDGING WILL PUSH INTO THE
MIDSOUTH FROM THE WEST AND TEMPS WILL CLIMB BACK ABOVE NORMAL WITH
LITTLE RAIN.
SJM
&&
.AVIATION...
VFR CONDS TO START OFF THIS TAF PERIOD...BUT CONDITIONS WILL
DETERIORATE THIS MORNING AT JBR AND MEM...AND THEN THIS AFTERNOON
FOR MKL AND TUP...AS BOTH CIGS/VIS DROP TO MVFR/IFR. BELIEVE ANY
LIFR/VLIFR CONDITIONS WILL BE VERY BRIEF AND NOT PREDOMINATE. A LARGE
SWATH OF SHOWERS WITH EMBEDDED THUNDERSTORMS ARE EXPECTED ALONG A
COLD FRONT...WITH RAIN HEAVY AT TIMES.
SOUTH TO SOUTHWEST WINDS AT 5-8KTS WILL VEER WEST AND EVENTUALLY NORTH
WITH THE FRONTAL PASSAGE.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 83 63 79 58 / 100 100 10 0
MKL 84 62 77 50 / 80 100 10 10
JBR 80 59 77 52 / 100 60 10 0
TUP 89 67 79 56 / 60 100 40 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1029 AM EDT FRI SEP 20 2013
.DISCUSSION...
THE MAIN FORECAST ISSUE OF THE DAY IS WHETHER CONVECTION WILL
DEVELOP THIS AFTERNOON OVER NE PORTIONS OF THE AREA. THE 12Z OHX
SOUNDING SHOWS A LITTLE MIDLEVEL CAPE...AND RUC AND NAM FORECAST
SOUNDINGS SHOW A -3 TO -4 LI THIS AFTERNOON AT TRI. AS IS TYPICALLY
THE CASE...THE GFS FORECAST SOUNDING IS MORE STABLE. FORCING WILL
BE LACKING BUT THERE WILL BE SOME LOW LEVEL MOISTURE TO WORK WITH.
THE CURRENT FORECAST OF SCATTERED TO ISOLATED POPS APPEARS
REASONABLE WITH NO COMPELLING EVIDENCE TO WARRANT A CHANGE. TEMPS
APPEAR ON TRACK AS WELL AND IN LINE WITH THE LATEST GUIDANCE...SO
NO UPDATE WILL BE NEEDED.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1222 AM CDT FRI SEP 20 2013
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 647 PM CDT THU SEP 19 2013/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION.
DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILER/WSR-88D VAD
WIND PROFILE TRENDS STILL PLACE AN UPPER LEVEL RIDGE AXIS OVER THE
SOUTHEAST UNITED STATES THIS AFTERNOON. THIS IS RESULTING IN
ACROSS THE MID SOUTH WITH ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM ACTIVITY THUS FAR LIMITED TO PORTIONS OF
CENTRAL/NORTH CENTRAL ARKANSAS AND SOUTH CENTRAL/SOUTHEAST
MISSOURI. TEMPERATURES AS OF 3 PM CDT ARE IN THE MIDDLE TO UPPER
80S AT MOST LOCATIONS. SHOWER AND THUNDERSTORM CHANCES ASSOCIATED
WITH AN APPROACHING COLD FRONT IS THE MAIN FORECAST CHALLENGE IN
THIS AFTERNOON/S FORECAST.
SHORT TERM MODELS INCLUDING THE 3KM HRRR INDICATE SHOWERS AND
THUNDERSTORMS LOCATED OVER PORTIONS OF ARKANSAS AND SOUTHERN
MISSOURI WILL WEAKEN AND DIMINISH WITH THE LOSS OF DAYTIME HEATING
THIS EVENING. THERE IS A POSSIBILITY THAT SOME OF THIS ACTIVITY
MAY REACH AREAS WEST OF THE MISSISSIPPI RIVER THIS EVENING AND
LEFT ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST. HOWEVER...THINK
BETTER SHOWER/THUNDERSTORM CHANCES WILL HOLD OFF UNTIL LATER
TONIGHT AS THE RIDGE MOVES FURTHER EAST AND MID LEVEL HEIGHT FALLS
WEAKEN SLIGHTLY.
A COLD FRONT CURRENTLY LOCATED OVER THE UPPER MIDWEST AND CENTRAL
PLAINS THIS AFTERNOON WILL DROP INTO THE LOWER MISSISSIPPI VALLEY
ON FRIDAY. MODEST MID LEVEL HEIGHT FALLS AND INSTABILITY WILL
ALLOW FOR SHOWERS AND THUNDERSTORMS TO OVERSPREAD THE MID SOUTH
MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER FRIDAY MORNING AND
SPREAD EAST TO THE REMAINDER OF THE FORECAST AREA FRIDAY AFTERNOON
INTO FRIDAY NIGHT.
NOT OVERLY IMPRESSED WITH STRONG/SEVERE THUNDERSTORM POTENTIAL AS
OVERALL SHEAR...INSTABILITY...AND FORCING WILL REMAIN ON THE WEAK
SIDE. LATER SHIFTS WILL MONITOR SHORT TERM TRENDS AND ADD STRONG
THUNDERSTORM MENTION IN THE HAZARDOUS WEATHER OUTLOOK IF
CONDITIONS BECOME MORE FAVORABLE AS THE FRONT APPROACHES. OVERALL
RAINFALL AMOUNTS THROUGH FRIDAY NIGHT MAY AVERAGE AROUND ONE HALF
INCH WITH LOCALIZED AMOUNTS UP TO PERHAPS 1.5-2 INCHES ALONG AND
WEST OF THE MISSISSIPPI RIVER...AND LESSER AMOUNTS TOWARDS THE
TENNESSEE RIVER. THE 12Z GFS HAS REMAINED ON THE QUICKER SIDE OF
MODEL SOLUTIONS TODAY AND LEANED FORECAST TOWARDS THE WRF/ECMWF
WHICH SUGGEST FRONTAL PASSAGE FRIDAY AFTERNOON/FRIDAY NIGHT.
LINGERING SHOWERS AND THUNDERSTORMS MAY PERSIST ON SATURDAY...ESPECIALLY
ACROSS NORTHEAST MISSISSIPPI AS THE FRONT SLOWS BEFORE DEPARTING
THE FORECAST AREA BY SATURDAY NIGHT. COOLER AND DRIER AIR WILL
FILTER IN BEHIND THE FRONT RESULTING IN A PERIOD OF MAINLY RAIN
FREE WEATHER ACROSS THE MID SOUTH THROUGH AT LEAST EARLY NEXT
WEEK AND TEMPERATURES AVERAGING NEAR NORMAL FOR SEPTEMBER. 12Z
GFS/ECMWF INDICATE SOME MODEL RUN TO RUN CONTINUITY ISSUES WITH
THE APPROACH OF AN UPPER LEVEL TROUGH OVER THE
PLAINS/MIDWEST...A BUILDING RIDGE OVER THE LOWER MISSISSIPPI
VALLEY AND THE POTENTIAL FOR WEAK SOUTHERLY LOW LEVEL RETURN FLOW
FROM THE GULF OF MEXICO PRODUCING SHOWERS AND THUNDERSTORMS. WILL
KEEP REMAINDER OF FORECAST NEXT WEEK DRY FOR NOW UNTIL MODELS
COME INTO BETTER AGREEMENT.
CJC
&&
.AVIATION...06Z TAF CYCLE
VFR CONDS WILL PREVAIL THROUGH TOMORROW MORNING AND WINDS WILL
REMAIN 5-9 KTS PREDOMINANTLY FROM THE SOUTH OVERNIGHT. TIMING OF
SHOWERS AHEAD OF AN APPROACHING COLD FRONT TOMORROW IS THE BIGGEST
CHALLENGE RIGHT NOW. HAVE DECIDED TO INTRODUCE VCSH AT 14Z AT
MEM...MKL...AND JBR WITH TUP FOLLOWING AROUND 16Z. WIDESPREAD RAIN
AND THUNDERSTORMS SHOULD BECOME PREVAILING BY 18Z AT ALL TAF SITES
AND CONTINUE THROUGH THE END OF THE TAF CYCLE AS THE COLD FRONT
MOVES THROUGH THE REGION. MVFR/IFR CONDITIONS WILL DEVELOP
THROUGHOUT THE AFTERNOON AT TIMES DUE TO VSBYS/CIGS FROM MODERATE
RAIN. EXPECT WINDS TO SHIFT NORTHERLY BY THE END OF THE TAF CYCLE.
AC3/JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 81 60 80 / 70 40 0 0
MKL 65 78 54 79 / 70 30 10 0
JBR 61 78 53 78 / 60 10 0 0
TUP 68 81 60 80 / 90 70 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
FOR AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION...VISIT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS TUCSON AZ
213 AM MST SUN SEP 22 2013
.SYNOPSIS...AN UPPER LEVEL TROUGH ALONG THE WEST COAST COUPLED WITH
A BIT OF MOISTURE OVER THE AREA WILL BE ENOUGH TO GENERATE A FEW
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST ARIZONA TODAY. GUSTY
WINDS ALSO DEVELOPING AHEAD OF THIS SYSTEM TODAY. THE WESTERLY FLOW
BEHIND THIS TROUGH WILL START TO PUSH DRIER AIR ACROSS THE AREA LATE
TODAY AND KNOCK TEMPERATURES BACK TO NEAR OR BELOW AVERAGE FOR THE
NEW WEEK.
&&
.DISCUSSION...WATER VAPOR IMAGERY SHOWS A TROUGH MAKING ITS WAY
THROUGH SOUTHERN CALIFORNIA...WITH A RIDGE CENTERED WELL TO THE
SOUTH OVER THE SOUTHERN GULF OF CALIFORNIA WITH THE RIDGE AXIS
EXTENDING NORTHEAST ACROSS WEST TEXAS AND WESTERN OKLAHOMA. IR
SATELLITE IMAGERY SHOWS MID LEVEL CLOUDS OVER MAINLY THE CENTRAL AND
EASTERN PORTIONS OF THE FORECAST AREA. THE MODELS...INCLUDING THE U
OF A WRF NAM...WRF GFS AND HRRR INDICATE THAT ISOLATED TO SCATTERED
SHOWERS AND/OR THUNDERSTORMS WILL DEVELOP OVER CENTRAL LOCATIONS
INITIALLY...THEN DEVELOP OVER AREAS MAINLY TO THE NORTHEAST AND EAST
OF THE TUCSON AREA...WITH THE BEST POTENTIAL OVER THE WHITE
MOUNTAINS OF NORTHERN GREENLEE COUNTY. THIS SYSTEM IS EXPECTED TO
SWEEP THROUGH THE REGION QUICKLY WITH THE TROUGH MOVING INTO
NORTHWEST ARIZONA THIS MORNING AND THEN OVER THE FOUR CORNERS AREA
BY LATE THIS AFTERNOON AND OVER SOUTHERN COLORADO AND NORTHERN NEW
MEXICO LATE THIS EVENING.
ON MONDAY DRY NORTHWEST FLOW ALOFT WILL BRING COOLER HIGH TEMPS TO
THE REGION WITH HIGH PRESSURE BUILDING IN BEHIND THE TROUGH DURING
THE DAY ON TUESDAY...AND WILL MOVE INTO THE SOUTHERN PLAINS BY LATE
TUESDAY/EARLY WEDNESDAY AS THE TAIL END OF ANOTHER MUCH STRONGER
PACIFIC TROUGH SWEEPS THROUGH THE NORTHERN PART OF THE STATE DURING
THE LATTER PART OF THE WEEK AND INTO THE EARLY PART OF THE
WEEKEND.
BREEZY CONDITIONS WILL DEVELOP TODAY AHEAD OF THE TROUGH. WINDS WILL
INCREASE AGAIN INTO THE BREEZY CATEGORY WEDNESDAY AND THURSDAY AHEAD
OF THE NEXT TROUGH.
THE BOTTOM LINE IS A DRY FORECAST THROUGH THE REMAINDER OF THE
FORECAST PERIOD...AFTER THE THREAT FOR SHOWERS ENDS LATE TODAY.
HIGH AND LOW TEMPERATURES GENERALLY HOVERING WITHIN A FEW DEGREES
EITHER SIDE OF NORMAL THROUGH THE ENTIRE FORECAST PERIOD. MOLLERE
&&
.AVIATION...VALID THROUGH 23/12Z. FEW070 SCT-BKN100 WITH ISOLD
SHRA/TSRA...22/19Z SCT-BKN070 BKN100 SCT TSRA...AFT 23/03Z CONDS
BECMG SKC. S-SE WIND 5 TO 12 KT BECMG SW 10 TO 18 KTS WITH GUSTS TO
30 KT AFT 22/17Z. WIND EASING TO W-SW 6 TO 10 KT AFT 23/03Z.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. CERNIGLIA
&&
.FIRE WEATHER...A SIGNIFICANT UPPER LEVEL TROUGH WILL CROSS THE
STATE TODAY GENERATING SCATTERED THUNDERSTORMS...MAINLY THE TUCSON
REGION AND EAST. SOME OF THE STORMS COULD BE STRONG. THIS SYSTEM
WILL ALSO KICK UP A DECENT SW WIND LATE THIS MORNING...CONTINUING
THROUGH THE AFTERNOON. THEN MUCH DRIER AIR WILL INVADE THE REGION
TONIGHT RESULTING IN DRY WEATHER AND MUCH LOWER HUMIDITY LEVELS
MONDAY THROUGH THE COMING WEEK WITH TEMPERATURES DROPPING TO AROUND
SEASONAL NORMS. ANOTHER PASSING UPPER LEVEL SYSTEM WILL KICK UP
SOUTHWEST BREEZES WEDNESDAY AND THURSDAY AFTERNOONS BUT IT IS
EXPECTED TO PASS BY DRY. CERNIGLIA
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
340 AM MDT SUN SEP 22 2013
.SHORT TERM...A RATHER POTENT SHORTWAVE TROUGH CURRENTLY OVER THE
WESTERN GREAT BASIN ALONG WITH A MID-LEVEL CIRCULATION CENTER
EVIDENT ON H20 VAPOR SAT IMAGERY SOUTHEAST OF RENO NV ARE PROGGED
TO MOVE EAST-SOUTHEAST FAIRLY QUICKLY THIS MORNING. DETERMINISTIC
MODELS AND ENSEMBLE MEMBERS ARE IN REASONABLY GOOD AGREEMENT AS
THEY SHOW THIS SYSTEM INTENSIFYING/DEEPENING SOME AS IT
APPROACHES WESTERN COLORADO. MODEL CONSENSUS HAS THE 500MB LOW
NEARING THE 4-CORNERS AREA BY 00Z/TODAY. FROM THERE MODELS SHOW
THE LOW TRACKING NORTHEASTWARD ACROSS CENTRAL AND NORTHEAST
COLORADO OVERNIGHT. A VIGOROUS PACIFIC COLD FRONT TRAILING
SOUTHWESTWARD ACROSS NEVADA FROM A SFC LOW IN SOUTHEAST IDAHO IS
ALSO FCST TO TRACK EAST WITH THE UPPER TROUGH. MODELS SHOW THIS
SHARP BAROCLINIC ZONE MOVING INTO WESTERN COLORADO NOT TOO LONG
AFTER 18Z/TODAY...AND THEN MOVING OUT ONTO THE NERN PLAINS OF
COLORADO EARLY THIS EVENING. MODELS/ENSEMBLE MEMBERS SHOW A SFC
LOW FORMING ON THE FRONT SOMEWHERE BETWEEN DENVER AND GREELEY.
STEEP MID-LEVEL LAPSE RATES AND RATHER ROBUST DEEP LAYER QG
ASCENT WITH THE UPPER LOW PASS OVER THE NORTH CENTRAL CO MTNS
THIS AFTERNOON RESULTING IN SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED TO SCATTERED T-STORMS. WETBULB ZERO EXPECTED TO REMAIN
ABOVE MTN TOP LEVEL DURING THE DAYLIGHT HOURS...BUT STG
EVAPORATIVE COOLING WITH CONVECTION COULD GENERATE A BRIEF BUT
INTENSE SNOW SHOWER ABOVE TIMBERLINE. IT NOW APPEARS AS THOUGH THE
PLAINS WILL SEE ITS BEST SHOT AT PRECIP THIS EVENING...OR PERHAPS
AS EARLY AS LATE THIS AFTERNOON. THE HRRR SHOWS WEAK TO MODERATE
REFLECTIVITIES OVER THE I-25 URBAN CORRIDOR AS EARLY AS 21Z/TODAY...
WHILE AT THE SAME TIME THE WRF AND NAM ONLY INDICATE WIDELY
SCATTERED WEAK ECHOS OVER THE FOOTHILLS AND PALMER DIVIDE.
HOWEVER ALL 3 MODELS INDICATE SEVERAL AREAS OF LIGHT TO MODERATE
REFLECTIVITY/QPF OVER THE FRONT RANGE AND OUT ACROSS THE NERN
PLAINS THIS EVENING. COULD SEE A FEW STRONG T-STORMS POP ON THE
PLAINS AROUND 00Z/MON JUST AHEAD OF THE COLD FRONT. NAM AND RAP
INDICATE AN ELONGATED AREA OF 750-1000 J/KG CAPE EXTENDING FROM
ELBERT COUNTY TO LOGAN COUNTY AROUND 00Z.
NAM AND GFS INDICATE THE GREATEST REFLECTIVITIES/QPF IN THE
N-CENTRAL MTNS AROUND SUMMIT COUNTY FROM 00Z-06Z THIS EVENING
WITH CAA FOLLOWING THE PASSAGE OF THE 700-500 TROUGH AXIS. QPF
TOTALS UP ALONG THE CONTINENTAL DIVIDE ON THE ORDER OF 0.35 TO
0.60 INCH BY MORNING. MODEL SNOW TOTALS RANGE FROM 1-4 INCHES IN
AREAS ROUGHLY ABOVE 9500 FEET. ELSEWHERE...SHOULD SEE AN END TO
THE SHOWERY PRECIP OVER AND NEAR THE EAST FACE OF THE FRONT RANGE
BY AROUND MIDNIGHT WITH THE DRYING EFFECTS OF DOWNSLOPE FLOW.
HOWEVER...FARTHER OUT ON THE PLAINS A TIGHT BAROCLINIC ZONE AND
LINGERING QG ASCENT ON THE BACKSIDE OF THE UPPER LOW WILL PROBABLY
KEEP LIGHT TO MODERATE PRECIP GOING THROUGHOUT THE NIGHT. RAIN
AMOUNTS IN THIS AREA BY MORNING GENERALLY UNDER A HALF INCH...WITH
LESSER AMOUNTS CLOSER IN TO THE FOOTHILLS. FLOODING IS NOT A
CONCERN AT THIS TIME.
TEMPERATURES TODAY ARE EXPECTED TO BE SLIGHTLY COOLER THAN YESTERDAY
BUT STILL SLIGHTLY ABOVE AVERAGE FOR THE DATE. HIGHS ON THE PLAINS
WILL RANGE FROM THE MID-70S NEAR THE FOOTHILLS TO THE MID-80S NEAR
THE NORTHEAST CORNER OF THE STATE. HIGH COUNTRY MAX TEMPS WILL RANGE
FROM THE MID-60S IN THE VALLEYS AND FOOTHILLS...TO AROUND 50 DEGS
ABOVE TIMBERLINE. TONIGHTS LOWS WILL RANGE FROM THE MID 40S/LOWER
50S ON THE PLAINS TO THE 20S/30S IN THE HIGH COUNTRY. GUSTY NWLY
WINDS OVER THE NRN FRONT RANGE OVERNIGHT MAY MAKE IT FEEL EVEN
COLDER THAN THAT.
.LONG TERM...RATHER POTENT UPPER LEVEL TROUGH WILL MOVE QUICKLY ACROSS
THE AREA MON MORNING. LOOKS LIKE THIS SYSTEM MAY CLOSE OFF OVER
ERN CO AND THEN MOVE INTO SWRN NE BY MIDDAY. WILL HAVE SOME
FAVORABLE MID LVL QG ASCENT MON MORNING OVER NERN CO WHICH SHOULD
LEAD TO A GOOD CHC OF SHOWERS OVER THE PLAINS. ALONG THE FRONT
RANGE THE LOW LVL FLOW WILL BE STG NWLY WHICH WILL LIMIT PCPN
CHANCES. IN THE MTNS WILL SEE SOME LINGERING SNOW SHOWERS IN THE
MORNING BUT ACTIVITY SHOULD END BY MIDDAY AS DRIER AIR SPREADS
ACROSS. AS THE UPPER LEVEL LOW INTENSIFIES OVER SWRN NE AND DECENT
SFC GRADIENT OCCURS WILL SEE GUSTY NWLY WINDS IN THE NRN FOOTHILLS
AND ACROSS THE PLAINS. FOR NOW WILL KEEP SPEEDS BLO HIGH WIND
CRITERIA. AS FOR HIGHS WILL KEEP READINGS IN THE UPPER 60S TO
LOWER 70S OVER NERN CO.
BY MON EVENING THE UPPER LEVEL SYSTEM WILL MOVE QUICKLY EASTWARD
WITH DIMINISHING WINDS AND PCPN ENDING OVER THE FAR NERN PLAINS.
FOR TUE AND WED THE FLOW ALOFT WILL BECOME MORE SWLY AS ANOTHER
UPPER LEVEL TROUGH DEVELOPS OVER THE WRN US. THIS WILL LEAD TO A
DRY WX PTRN WITH WARMER TEMPS. HIGHS BY WED WILL BE IN THE LOWER TO
MID 80S OVER NERN CO.
BY THU ONE PIECE OF THE UPPER LEVEL TROUGH OVER THE WRN US WILL
MOVE ACROSS THE NRN ROCKIES WHILE A SECOND PIECE OF ENERGY MOVES
INTO THE GREAT BASIN. THIS WILL LEAVE NRN CO IN SWLY FLOW ALOFT.
SOME MOISTURE WILL INCREASE IN THE MTNS HOWEVER IT APPEARS BEST
CHC OF PCPN THU AFTN WILL STAY MAINLY OVER WRN CO THRU THU NIGHT.
HIGHS ON THU WILL REMAIN ABV NORMAL OVER NERN CO.
FOR FRI THE UPPER LEVEL TROUGH OVER THE GREAT BASIN WILL BEGIN TO
MOVE EAST AS A COLD FRONT MOVES INTO NERN CO. SHOULD SEE A GOOD
CHANCE OF RAIN AND SNOW IN THE MTNS WITH A CHC OF RAIN OVER NERN CO.
HIGHS ON FRI WILL TURN COOLER WITH READINGS IN THE 60S OVER THE
PLAINS. THE UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA BY SAT
WITH DRIER WEATHER AND SEASONAL TEMPERATURES.
&&
.AVIATION...SCATTERED HIGH CLOUDS EARLY THIS MORNING OVER THE
DENVER METRO AREA WILL GRADUALLY LOWER AS CLOUDS INCREASE IN
ADVANCE OF A PACIFIC COLD FRONT AND UPPER LEVEL LOW PRESSSURE
TROUGH TO OUR WEST. SOUTH-SOUTHWEST SFC WINDS OF 6-13KTS THIS
MORNING WILL GRADUALLY TURN EAST-SOUTHEASTERLY LATE MORNING/EARLY
AFTERNOON AS THE SURFACE TROUGH ALONG THE FOOTHILLS DEEPENS AHEAD
OF THE COLD FRONT. WESTERN PORTIONS OF THE DENVER METRO AREA
INCLUDING APA COULD SEE ISOLATED TO SCATTERED RAIN SHOWERS/
T-STORMS FORMING AFTER 21Z TODAY WITH THE ATMOSPHERE BECOMING
INCREASINGLY UNSTABLE. HOWEVER IT APPEARS THAT DENVER AREA
TERMINALS WILL SEE THEIR BEST CHANCE FOR SHOWERS/T-SHOWERS THIS
EVENING FROM 00Z-06Z JUST PRIOR TO AND SHORTLY AFTER PASSAGE OF
THE PACIFIC COLD FRONT. THE STRONGEST STORMS WILL LIKELY FORM
EAST OF THE METRO AREA WHERE THE LOWER ATMOSPHERE WILL BE MORE
MOIST AND UNSTABLE. CLOUD CEILINGS COULD BRIEFLY LOWER TO AROUND
5000 FT AGL WITH MODERATE RAINFALL THIS EVENING. EXPECT WINDS
AROUND SHOWERS/T-SHOWERS TO ALSO BE QUITE GUSTY AND VARIABLE IN
DIRECTION. CEILINGS SHOULD BEGIN RISING WITH SHOWERS ENDING AFTER
MIDNIGHT AS DRIER AIR MOVES IN BEHIND THE COLD FRONT.
HOWEVER...DIA COULD POSSIBLY SEE CIGS LOWERING AGAIN TO AROUND
3000 FT AGL WITH STRATUS TOWARDS MORNING. THE STRATUS WILL BE A
PRODUCT OF MOIST OUTFLOW FROM SHOWERS FARTHER OUT ON THE PLAINS.
&&
.HYDROLOGY...SCATTERED TO LIKELY SHOWERS AND ISOLATED TO SCATTERED
THUNDERSTORMS IN THE HIGH COUNTRY THIS AFTERNOON COULD PRODUCE
RAINFALL AMOUNTS RANGING FROM A QUARTER TO ONE-HALF INCH. SIMILAR
RAIN AMOUNTS ARE POSSIBLE ON THE PLAINS AND OVER THE FOOTHILLS
LATE THIS AFTERNOON AND EVENING. SHOWERS AND STORMS WILL MOVE
FAIRLY QUICKLY TODAY AND SO THE RISK OF HEAVY RAINFALL LEADING TO
FLASH FLOODING IS LOW. IN THE HIGH COUNTRY...ELEVATIONS ABOVE
AROUND 9500 FEET COULD SEE 2-4 INCHES OF SNOW ACCUMULATE BY
MORNING. AREAS ABOVE TIMBERLINE AS WELL AS WEST AND NORTHWEST
FACING SLOPES ARE IN THE BEST POSITION TO SEE THIS ACCUMULATION.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....RPK
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
450 AM EDT SUN SEP 22 2013
.SYNOPSIS...
WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS AND AN ISOLATED
THUNDERSTORM WILL SWEEP ACROSS SOUTHERN NEW ENGLAND TODAY INTO
THIS EVENING ALONG AND AHEAD OF A COLD FRONT. OTHERWISE...HIGH
PRESSURE WILL RESULT IN AN EXTENDED PERIOD OF DRY WEATHER FOR THE
REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 AM UPDATE...
SURFACE COLD FRONT...AS DISCERNED FROM DISTINCT FINE-LINE WITHIN
RADAR REFLECTIVITY...IS QUICKLY PRESSING EAST. CONTINUE TO MONITOR
WIDESPREAD RAIN WITH EMBEDDED HEAVIER SHOWERS ALONG AND AHEAD OF
THE FRONT WHICH ARE ALLOWING THE EFFECTIVE MIX-DOWN OF MOMENTUM TO
THE SURFACE THROUGH THE MORE STABLE BOUNDARY LAYER. WITNESSING
GUSTS AROUND 25 MPH PRIOR TO AND DURING PASSAGE OF THE COLD FRONT
WITH BREEZY SOUTHERLY FLOW BACKING OUT OF THE WEST AND IMMEDIATELY
BECOMING BLUSTERY.
ALSO CLOSELY WATCHING RADAR DERIVED ONE-HOUR RAINFALL AMOUNTS.
CONSIDERING NOTHING EXCEEDING ONE-INCH IN AN HOUR...COMBINED WITH
THE FACT THAT IT HASN/T RAINED FOR SEVERAL DAYS AND THE SYSTEM
ITSELF IS QUICKLY PROGRESSING THROUGH THE REGION...FEEL THE THREAT
OF ANY FLOODING IS SUBSTANTIALLY REDUCED AND SO WILL REMOVE ANY
FURTHER MENTION FROM THIS DISCUSSION. STILL CAN NOT RULE OUT TOTAL
RAINFALL AMOUNTS WITH CONCLUSION OF THE SYSTEM TO EXCEED ONE INCH.
FAVORING THE 23.0Z NAM WITH THE 22.21Z SREF...AND INCORPORATING
THE LATEST HRRR THOUGH ADJUSTING IT 2 HOURS FASTER...HAVE UPDATED
POP AND RAINFALL ACCUMULATION GRIDS ACCORDINGLY. CONTINUE AN
ISOLATED MENTION OF THUNDER.
TODAY...
CONTINUED STRONG DYNAMICS AND SUBSTANTIAL DEEP-LAYER MOISTURE ALONG
AND AHEAD OF A SURFACE COLD FRONT EXPECTED TO PUSH OFF CAPE COD BY
THE LATE AFTERNOON HOURS. SHOWERS LINGERING LONGEST ACROSS SOUTHEAST
NEW ENGLAND WITH THE POSSIBILITY OF A SECONDARY WEAK AREA OF LOW
PRESSURE IN VICINITY OF THE REGION ALONG THE COLD FRONT. WILL NEED
TO CLOSELY WATCH FOR AN INFLECTION POINT WITHIN THE WATER VAPOR
SATELLITE LOOP.
CONSIDERING PWATS UP TO 1.75 INCHES AND WEAK INSTABILITY SNEAKING
NORTHWARD INTO SOUTHERN NEW ENGLAND...EXPECT POCKETS OF HEAVY RAIN
WITH ISOLATED THUNDERSTORMS. THIS PRESENTS THE THREAT OF LOCALIZED
URBAN AND POOR DRAINAGE FLOODING MAINLY FOR AREAS EAST OF THE
CONNECTICUT RIVER VALLEY.
DRY SLOT WORKING INTO THE REAR OF THE MID-LEVEL LOW AS WINDS BACK
OUT OF THE WEST-NORTHWEST IMMEDIATELY BEHIND THE FRONT BECOMING
BLUSTERY. WILL SEE CONDITIONS CLEAR RATHER QUICKLY WITH COLD AIR
ADVECTION PROCEEDING WITHIN THE LOW- TO MID-LEVELS. THIS WILL KEEP
HIGHS AROUND THE UPPER-60S TO LOW-70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY MORNING/...
NORTHWESTERLY FLOW DIMINISHING...BUT CAN/T RULE OUT CONTINUED
BLUSTERY CONDITIONS ALONG THE NEAR-SHORE AND ADJACENT WATERS. MOSTLY
CLEAR CONDITIONS PREVAIL WITH THE POSSIBILITY OF SOME LOW- TO MID-
LEVEL CLOUDS ACROSS N/W NEW ENGLAND IN PROXIMITY TO THE CYCLONIC
DEEP LOW /OROGRAPHIC UPSLOPE OF REMNANT MOISTURE/.
COLDER AIMASS BUILDING SOUTH AND EAST OVER THE REGION /H85 AROUND
+4C/. WESTERLY FLOW AIDING COLD AIR ADVECTION PROCESSES. FAIRLY
CHILLY NIGHT...BUT NOT RECORD BREAKING. LOWS AROUND THE LOW- TO MID-
40S...WITH HIGHER ELEVATIONS INTO THE UPPER 30S.
MINIMUM TEMPERATURE RECORDS FOR SEPTEMBER 23RD:
BOSTON 35 /1904/
HARTFORD 34 /1974/
PROVIDENCE 38 /1974/
WORCESTER 32 /1904/
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* DRY WEATHER THROUGH NEXT SATURDAY
* BELOW NORMAL TEMPS MON/TUE MODERATE TO NEAR NORMAL BY MID WEEK
DETAILS...
MONDAY...
CLOSED LOW OVER THE CANADIAN MARITIMES WILL RESULT IN A NORTHWEST
FLOW OF DRY BUT COOL WEATHER. 850 MB TEMPS DROPPING TO BELOW +4C
SHOULD KEEP HIGHS IN THE UPPER 50S ACROSS THE INTERIOR HIGH
TERRAIN...TO THE LOWER TO MIDDLE 60S ELSEWHERE UNDER A MIXTURE OF
CLOUDS AND SUNSHINE. THESE HIGHS ARE AROUND 10 DEGREES BELOW NORMAL
FOR LATE SEPTEMBER.
MONDAY NIGHT...
WINDS DIMINISH AND WITH MOSTLY CLEAR SKIES IN
PLACE...EXPECT A GOOD NIGHT OF RADIATIONAL COOLING. LOW TEMPS
SHOULD BOTTOM OUT IN THE MIDDLE 30S ACROSS THE NORMALLY COOLEST
OUTLYING LOCATIONS...TO THE LOWER TO MIDDLE 40S IN MANY OF THE URBAN
CENTERS. THE MILD SPOT WILL LIKELY BE THE URBAN HEAT ISLAND OF
BOSTON WITH EXPECTED LOWS IN THE UPPER 40S. THERE IS A MODERATE
PROBABILITY WILL NEED FROST ADVISORIES FOR PORTIONS OF SOUTHWEST
NH/WESTERN MA LATE MON NIGHT/EARLY TUE AM...BUT ITS A 4TH PERIOD
EVENT SO NO HEADLINES AT THIS TIME.
TUESDAY....
DESPITE A CHILLY EARLY START...SUNSHINE AND SOME MID LEVEL WARMING
WILL ALLOW FOR A NICE RECOVERY IN TEMPS BY AFTERNOON. HIGHS SHOULD
TOP OUT WELL INTO THE 60S ACROSS MOST LOCATIONS.
WEDNESDAY THROUGH SATURDAY...
CLOSED UPPER LEVEL LOW ACROSS THE
CANADIAN MARITIMES WILL LIFT A BIT FURTHER TO THE NORTH. THIS WILL
ALLOW TEMPS TO MODERATE BACK TO NEAR NORMAL LEVELS...WITH HIGHS
MAINLY IN THE UPPER 60S AND LOWER 70S. HOWEVER...THE TRUE
SUMMERLIKE TEMPS SHOULD REMAIN TO OUR WEST WHERE HEIGHT FIELDS WILL
BE HIGHER. AS FOR PRECIP CHANCES...UPPER LEVEL TROUGH AXIS WILL
REMAIN EAST OF OUR REGION SO EXPECT AN EXTENDED PERIOD OF DRY
WEATHER OVER THIS TIME.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...
8Z UPDATE...
MVFR/IFR PREVAILING WITH RAIN. COULD SEE ISOLATED POCKETS OF
LIFR/VLIFR WITH DENSE FOG AND/OR +RA ALONG AND AHEAD OF A COLD
FRONT SWEEPING ACROSS THE TERMINALS...EXPECCTED TO BE OFFSHORE OF
CAPE COD BY LATE AFTERNOON. BREEZY SOUTHERLY WINDS WILL BACK OUT
OF THE WEST WITH FRONTAL PASSAGE AND IMMEDIATELY BECOME BLUSTERY.
GUSTS AROUND 25 KTS. LLWS ISSUES CONTINUE AS WINDS JUST 2 KFT AGL
REMAIN AROUND 40 KTS PER TAUNTON RADAR WIND PROFILER.
WILL SEE IMMEDIATE IMPROVEMENT THROUGH THE DAY AS THE COLD FRONT
AND ATTENDANT WET WEATHER SLIDE EAST. VFR EXPECTED BY EVENING AND
OVERNIGHT. LIGHTER WESTERLY WINDS COULD PRESENT THE OPPORTUNITY
FOR PATCHY DENSE FOG IN SHELTERED VALLEY REGIMES /CONNECTICUT
RIVER VALLEY...MONADNOCKS...WORCESTER HILLS/.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING.
OUTLOOK...MONDAY THROUGH THURSDAY...
HIGH CONFIDENCE IN MAINLY VFR CONDITIONS. THE EXCEPTION WILL BE
PATCHY LATE NIGHT/EARLY MORNING GROUND FOG IN THE TYPICALLY PRONE
LOCATIONS AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY MORNING/...HIGH CONFIDENCE.
4 AM UPDATE...
SURFACE COLD FRONT SLIDING THROUGH THE WATERS DURING THE COURSE OF
TODAY INTO THIS EVENING. BREEZY SOUTHERLY FLOW AHEAD OF THE FRONT
WITH HEAVY /VISIBILITY REDUCING/ RAIN AND GUSTS UP TO AROUND 25
KTS...WHICH WILL BE IMMEDIATELY FOLLOWED BY BLUSTERY WESTERLY
WINDS WITH GUSTS UP TO 25 KTS DURING FRONTAL PASSAGE. WESTERLY
WINDS DIMINISH AS THE FRONT PROGRESSES FURTHER EAST.
HAVE EXTENDED THE SMALL CRAFT ADVISORIES ACCORDINGLY THROUGH
MONDAY MORNING FOR THE OUTER WATERS. WILL SEE THE INNER WATERS
DROP OFF IN STAGES AS THE COLD FRONT MOVES FURTHER TO THE EAST.
EXPECT THE THREATS OF WIND GUSTS UP TO AROUND 25 KTS AND SEAS AS
HIGH AS 7 FEET ON THE OUTER WATERS.
OUTLOOK...MONDAY THROUGH THURSDAY...
HIGH CONFIDENCE. MARGINAL 5 FOOT SEAS AND LOW 20 KNOT NORTHWEST
WIND GUSTS MAY FLIRT WITH OUT EASTERN ATLANTIC WATERS AT TIMES MON
INTO EARLY TUE. THIS A RESULT OF COOL ADVECTION PROMOTING GOOD
MIXING OVER THE RELATIVELY MILD OCEAN. OTHERWISE...WINDS/SEAS
SHOULD REMAIN BELOW SCA THE REST OF THIS PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR
ANZ231>234-236-251.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ235-
237.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ250-254>256.
&&
$$
SYNOPSIS...FRANK/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...FRANK
AVIATION...FRANK/SIPPRELL
MARINE...FRANK/SIPPRELL
AREA FORECAST DISCUSSION
NWS ALBANY NY
142 AM EDT SUN SEP 22 2013
.SYNOPSIS...
WIDESPREAD SHOWERS ARE EXPECTED TONIGHT AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. THE RAIN MAY BE HEAVY AT TIMES
TONIGHT. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION BY SUNDAY
NIGHT AND IS THEN EXPECTED TO DOMINATE THE WEATHER MUCH OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1225 AM EDT...A COLD FRONT IS MOVING TOWARDS OUR FORECAST
AREA FOR THE OVERNIGHT HOURS. AHEAD OF THIS BOUNDARY IS A BAND OF
LIGHT TO MODERATE RAIN SHOWERS ALONG WITH A NARROW PRE FRONTAL
RAIN BAND CONTAINING HEAVY RAIN. THE LATEST 3KM HRRR SHOWS THIS
RAIN BAND NICELY AS IT MOVES EASTWARD FROM THE HUDSON VALLEY INTO
WESTERN NEW ENGLAND...AND THIS IS THE AREA MOST LIKELY TO SEE THE
HEAVIEST RAIN DURING THE REMAINDER OF THE OVERNIGHT HOURS. WE WILL
MENTION WIDESPREAD MODERATE RAIN SHOWERS FOR THE ENTIRE
REGION...ESP CONSIDERING HOW OUR PWATS HAVE RISEN TO 1.37 INCHES
ON THE 00Z KALY SOUNDING. MOST AREAS LOOK TO SEE A HALF INCH TO
ONE INCH OF RAIN...WITH LOCALLY HIGHER AMOUNTS OVER THE HIGH
TERRAIN OF WESTERN NEW ENGLAND. WITH LIMITED INSTABILITY AND NO
LTG STRIKES OVER THE LAST 6 HOURS...HAVE REMOVED MENTION OF
THUNDER FROM THE FORECAST AS WELL. RAIN SHOWERS LOOK TO END FROM
WEST TO EAST LATER TONIGHT AS THE FRONT CROSSES THE REGION AND THE
WINDS TURN WEST.
FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT THIS TIME...HOWEVER
WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE ON MAJOR RIVERS.
WHAT IS MORE LIKELY IS PONDING OF WATER AND FLOODING OF POOR
DRAINAGE AND LOW LYING AREAS...MAINLY ACROSS WESTERN NEW ENGLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
TROUGH AXIS WILL SWING THROUGH SUNDAY AS SHORT WAVE ROTATES THROUGH
BASED OF UPPER LEVEL LOW MOVING ACROSS EASTERN CANADA. PRECIPITATION
WILL TAPER OFF FROM SOUTHWEST TO NORTHEAST DURING THE MORNING HOURS.
THE PRESSURE GRADIENT WILL TIGHTEN UP ACROSS THE REGION SUNDAY AND
WESTERLY WINDS WILL BECOME BRISK USHERING IN A COLDER AIRMASS
AIRMASS. CONDITIONS WILL REALLY BEGIN TO IMPROVE LATER IN THE
AFTERNOON INTO EVENING WITH DECREASING CLOUDS AND WEAKENS WINDS AS
THE PRESSURE GRADIENT LOOSENS ACROSS THE REGION AND HEIGHTS BEGIN TO
RISE.
IT WILL GET COLD AT NIGHT WITH LOWS BOTTOMING OUT MAINLY IN THE 30S.
DESPITE THE COLD TEMPERATURES CONDITIONS WILL BE FAVORABLE FOR
WIDESPREAD FROST DEVELOPMENT AS WE MAINTAIN A NORTHWEST WIND THROUGH
THE OVERNIGHT...WEAKEN TO 5 TO 10 MPH. COLDER TEMPERATURES WILL BE
ACROSS THE HIGHER TERRAIN WHERE SOME CLOUDS COVER WILL LINGER.
RIDGING BUILDS IN AT SURFACE AND HEIGHTS WILL BE RISING ALOFT
MONDAY. HOWEVER...A STACKED LOW DEVELOPS OVER NORTHERN NEW ENGLAND
AND IT WILL MOVE LITTLE THROUGH TUESDAY. THIS WILL MAINTAIN A
NORTHWESTERLY FLOW OVER THE REGION.
DESPITE LOTS OF SUNSHINE MONDAY...THE FIRST FULL OF DAY OF FALL WILL
BE CHILLY. HIGHS ARE ONLY EXPECTED TO BE IN THE LOWER 50S TO LOWER
60S...AROUND 10 DEGREES BELOW NORMAL. IN ADDITION...WE WILL HAVE A
BRISK NORTHWESTERLY WINDS WHICH WILL MAKE IT FEEL EVEN COLDER.
CONDITIONS WILL BE MORE FAVORABLE FOR WIDESPREAD FROST MONDAY NIGHT
WITH MOSTLY CLEAR SKIES AND WINDS DIMINISHING LATE AT NIGHT. LOOKING
FOR LOWS IN THE 30S WITH THE COLDER TEMPERATURES ACROSS THE HIGHER
TERRAIN.
TEMPERATURES WILL MODERATE CLOSER TO SEASONABLE LEVELS TUESDAY...BUT
REMAIN BELOW NORMAL BY 5 TO 10 DEGREES. OUR REGION WILL BE
SANDWICHED BETWEEN THE RIDGE AXIS TO OUR WEST ACROSS THE OHIO VALLEY
AND GREAT LAKES REGION AND THE LARGE STACKED LOW WOBBLING OVER
NORTHERN NEW ENGLAND.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MUCH OF THE EXTENDED PERIOD WILL FEATURE QUIET WEATHER WITH
TEMPERATURES MODERATING ABOVE NORMAL.
AT THE START OF THE EXTENDED PERIOD...A CUTOFF UPPER LEVEL LOW OVER
ATLANTIC CANADA WILL BE DEPARTING OUT TO SEA...WHILE AN UPPER LEVEL
RIDGE WILL BE SITUATED OVER THE MIDWEST AND GREAT LAKES REGION. WITH
CLEAR SKIES AND LIGHT WINDS...TEMPS WILL BE COOL ON TUES NIGHT/WED
MORNING...WITH 30S TO LOW 40S OVER MUCH OF THE AREA. THERE MAY BE
SOME FROST ISSUES FOR THOSE AREAS WHERE THE GROWING SEASON IS STILL
ONGOING...SUCH AS THE CATSKILLS OR SOUTHERN VT.
A WEAK UPPER LEVEL DISTURBANCE WILL ATTEMPT TO MOVE AROUND THE UPPER
RIDGING OVER THE GREAT LAKES FOR WED AND THURS...AND THE MODELS SHOW
DIFFERENCES IN EXACTLY WHERE IT MOVES. THE 12Z ECMWF SHOWS THIS
FEATURE SLIDING UNDER THE RIDGE TOWARDS THE SOUTHEAST...WHILE THE
12Z GFS WEAKENS AND FLATTENS THE RIDGE ENOUGH TO MOVE THE
DISTURBANCE ACROSS THE NORTHEAST. WITH THIS FEATURE BEING RATHER
WEAK AND MOISTURE STARVED...EITHER SCENARIO WOULD KEEP OUR REGION
DRY. MAX TEMPS WILL BE IN THE UPPER 60S TO LOW 70S FOR VALLEY
AREAS...WHICH IS NEAR TO SLIGHTLY ABOVE NORMAL.
BEHIND THAT WEAK UPPER LEVEL DISTURBANCE...BOTH MODELS SHOWS STRONG
RIDGING REESTABLISHING ITSELF ALONG THE EASTERN SEABOARD FOR FRIDAY
INTO SATURDAY. UNDER PLENTY OF SUNSHINE AND CONTINUED DRY
CONDITIONS...THIS SHOULD ALLOW MAX TEMPS TO REACH INTO THE 70S
ACROSS MOST OF THE REGION...WITH MID 70S FOR THE CAPITAL REGION AND
MID HUDSON VALLEY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 145 AM EDT...A BAND OF LIGHT TO MODERATE RAINFALL...WITH AN
EMBEDDED NARROW LINE OF HEAVY SHOWERS...CONTINUES TO AFFECT THE
REGION...WITH THE HEAVIER LINE OF SHOWERS NOW ENTERING WESTERN NEW
ENGLAND. CONDITIONS IN THE WAKE OF THE HEAVIER LINE OF SHOWERS WAS
MAINLY VFR TO MVFR. THE COLD FRONT WAS CURRENTLY CROSSING CENTRAL NYS.
THIS BAND OF SHOWERS WILL END FROM W TO E OVER THE NEXT 1-2 HOURS.
BETWEEN THIS BAND...AND THE COLD FRONT...A LIGHT SOUTHWEST WIND
WILL OCCUR WITH MAINLY MVFR CIGS. THERE IS A SLIGHT CHC THAT SOME
IFR CIGS COULD DEVELOP...ESP AT KPSF BEFORE THE COLD FRONT MOVES
ACROSS BETWEEN 08Z-10Z...AND FOR NOW...HAVE ONLY INDICATED IFR
CONDITIONS AT KPSF...WHICH COULD LINGER EVEN AFTER THE FRONTAL
PASSAGE DUE TO A DEVELOPING UPSLOPE WESTERLY FLOW OF MOIST AIR.
SOME SPOTTY LIGHT SHOWERS MAY PERSIST AT KGFL AND KALB THROUGH
SUNRISE IN THE WAKE OF THE FRONT.
AFTER SUNRISE...ANY MVFR/IFR CIGS SHOULD BECOME MAINLY VFR THROUGH
THE DAY. CONDITIONS SHOULD BECOME MOSTLY CLEAR LATER SUNDAY INTO
SUNDAY NIGHT AT KPOU...ALTHOUGH SOME PATCHY CLOUDS MAY LINGER
ELSEWHERE.
WINDS BRIEFLY SHIFTING INTO THE WEST AND GUSTED UP TO 25-30 KT
WITH THE INITIAL LINE OF HEAVIER SHOWERS. IN ITS WAKE...WINDS
SHIFT BACK INTO THE SOUTH TO SOUTHWEST AHEAD OF THE INCOMING COLD
FRONT...WITH SPEEDS GENERALLY LESS THAN 8 KT. EXPECT WINDS TO
SHIFT BACK INTO THE WEST TO NORTHWEST ONCE THE FRONT PASSES
BETWEEN 08Z-10Z AT 8-12 KT. WEST TO NORTHWEST WINDS WILL PERSIST
THROUGH SUNDAY AT 8-12 KT...WITH OCCASIONAL GUSTS OF 20-25
KT...ESP AT KALB AND KPSF. WIND SPEEDS SHOULD GRADUALLY DIMINISH
AFTER SUNSET TO 10 KT OR LESS.
OUTLOOK...
SUNDAY NIGHT-THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
WIDESPREAD PRECIPITATION TONIGHT INTO SUNDAY AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
&&
.HYDROLOGY...
WIDESPREAD PRECIPITATION TONIGHT AS A COLD FRONT APPROACHES AND
CROSSES THE REGION. PRECIPITABLE WATERS VALUES ARE EXPECTED TO
INCREASE TO AROUND 1 1/2 INCHES AHEAD OF THE FRONTAL BOUNDARY WHICH
IS ABOUT 1 1/2 STANDARD DEVIATIONS ABOVE NORMAL. RAINFALL AMOUNTS OF
1 TO 1 1/2 INCHES ARE EXPECTED WITH LOCALLY HIGHER AMOUNTS OF 2 TO
POSSIBLY 3 INCHES. FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT
THIS TIME...HOWEVER WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE
ON MAJOR RIVERS. WHAT IS LIKELY IS PONDING OF WATER AND FLOODING OF
POOR DRAINAGE AND LOW LYING AREAS. CAN NOT RULE OUT ISOLATED FLASH
FLOODING.
THE UPPER LOW AND TROUGH AXIS WILL MOVE ACROSS THE REGION SUNDAY.
THE STEADY PRECIPITATION WILL TAPER OFF FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/FRUGIS
NEAR TERM...IAA/FRUGIS/11
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...KL/FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1228 AM EDT SUN SEP 22 2013
.SYNOPSIS...
WIDESPREAD SHOWERS ARE EXPECTED TONIGHT AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. THE RAIN MAY BE HEAVY AT TIMES
TONIGHT. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION BY SUNDAY
NIGHT AND IS THEN EXPECTED TO DOMINATE THE WEATHER MUCH OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1225 AM EDT...A COLD FRONT IS MOVING TOWARDS OUR FORECAST
AREA FOR THE OVERNIGHT HOURS. AHEAD OF THIS BOUNDARY IS A BAND OF
LIGHT TO MODERATE RAIN SHOWERS ALONG WITH A NARROW PRE FRONTAL
RAIN BAND CONTAINING HEAVY RAIN. THE LATEST 3KM HRRR SHOWS THIS
RAIN BAND NICELY AS IT MOVES EASTWARD FROM THE HUDSON VALLEY INTO
WESTERN NEW ENGLAND...AND THIS IS THE AREA MOST LIKELY TO SEE THE
HEAVIEST RAIN DURING THE REMAINDER OF THE OVERNIGHT HOURS. WE WILL
MENTION WIDESPREAD MODERATE RAIN SHOWERS FOR THE ENTIRE
REGION...ESP CONSIDERING HOW OUR PWATS HAVE RISEN TO 1.37 INCHES
ON THE 00Z KALY SOUNDING. MOST AREAS LOOK TO SEE A HALF INCH TO
ONE INCH OF RAIN...WITH LOCALLY HIGHER AMOUNTS OVER THE HIGH
TERRAIN OF WESTERN NEW ENGLAND. WITH LIMITED INSTABILITY AND NO
LTG STRIKES OVER THE LAST 6 HOURS...HAVE REMOVED MENTION OF
THUNDER FROM THE FORECAST AS WELL. RAIN SHOWERS LOOK TO END FROM
WEST TO EAST LATER TONIGHT AS THE FRONT CROSSES THE REGION AND THE
WINDS TURN WEST.
FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT THIS TIME...HOWEVER
WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE ON MAJOR RIVERS.
WHAT IS MORE LIKELY IS PONDING OF WATER AND FLOODING OF POOR
DRAINAGE AND LOW LYING AREAS...MAINLY ACROSS WESTERN NEW ENGLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
TROUGH AXIS WILL SWING THROUGH SUNDAY AS SHORT WAVE ROTATES THROUGH
BASED OF UPPER LEVEL LOW MOVING ACROSS EASTERN CANADA. PRECIPITATION
WILL TAPER OFF FROM SOUTHWEST TO NORTHEAST DURING THE MORNING HOURS.
THE PRESSURE GRADIENT WILL TIGHTEN UP ACROSS THE REGION SUNDAY AND
WESTERLY WINDS WILL BECOME BRISK USHERING IN A COLDER AIRMASS
AIRMASS. CONDITIONS WILL REALLY BEGIN TO IMPROVE LATER IN THE
AFTERNOON INTO EVENING WITH DECREASING CLOUDS AND WEAKENS WINDS AS
THE PRESSURE GRADIENT LOOSENS ACROSS THE REGION AND HEIGHTS BEGIN TO
RISE.
IT WILL GET COLD AT NIGHT WITH LOWS BOTTOMING OUT MAINLY IN THE 30S.
DESPITE THE COLD TEMPERATURES CONDITIONS WILL BE FAVORABLE FOR
WIDESPREAD FROST DEVELOPMENT AS WE MAINTAIN A NORTHWEST WIND THROUGH
THE OVERNIGHT...WEAKEN TO 5 TO 10 MPH. COLDER TEMPERATURES WILL BE
ACROSS THE HIGHER TERRAIN WHERE SOME CLOUDS COVER WILL LINGER.
RIDGING BUILDS IN AT SURFACE AND HEIGHTS WILL BE RISING ALOFT
MONDAY. HOWEVER...A STACKED LOW DEVELOPS OVER NORTHERN NEW ENGLAND
AND IT WILL MOVE LITTLE THROUGH TUESDAY. THIS WILL MAINTAIN A
NORTHWESTERLY FLOW OVER THE REGION.
DESPITE LOTS OF SUNSHINE MONDAY...THE FIRST FULL OF DAY OF FALL WILL
BE CHILLY. HIGHS ARE ONLY EXPECTED TO BE IN THE LOWER 50S TO LOWER
60S...AROUND 10 DEGREES BELOW NORMAL. IN ADDITION...WE WILL HAVE A
BRISK NORTHWESTERLY WINDS WHICH WILL MAKE IT FEEL EVEN COLDER.
CONDITIONS WILL BE MORE FAVORABLE FOR WIDESPREAD FROST MONDAY NIGHT
WITH MOSTLY CLEAR SKIES AND WINDS DIMINISHING LATE AT NIGHT. LOOKING
FOR LOWS IN THE 30S WITH THE COLDER TEMPERATURES ACROSS THE HIGHER
TERRAIN.
TEMPERATURES WILL MODERATE CLOSER TO SEASONABLE LEVELS TUESDAY...BUT
REMAIN BELOW NORMAL BY 5 TO 10 DEGREES. OUR REGION WILL BE
SANDWICHED BETWEEN THE RIDGE AXIS TO OUR WEST ACROSS THE OHIO VALLEY
AND GREAT LAKES REGION AND THE LARGE STACKED LOW WOBBLING OVER
NORTHERN NEW ENGLAND.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MUCH OF THE EXTENDED PERIOD WILL FEATURE QUIET WEATHER WITH
TEMPERATURES MODERATING ABOVE NORMAL.
AT THE START OF THE EXTENDED PERIOD...A CUTOFF UPPER LEVEL LOW OVER
ATLANTIC CANADA WILL BE DEPARTING OUT TO SEA...WHILE AN UPPER LEVEL
RIDGE WILL BE SITUATED OVER THE MIDWEST AND GREAT LAKES REGION. WITH
CLEAR SKIES AND LIGHT WINDS...TEMPS WILL BE COOL ON TUES NIGHT/WED
MORNING...WITH 30S TO LOW 40S OVER MUCH OF THE AREA. THERE MAY BE
SOME FROST ISSUES FOR THOSE AREAS WHERE THE GROWING SEASON IS STILL
ONGOING...SUCH AS THE CATSKILLS OR SOUTHERN VT.
A WEAK UPPER LEVEL DISTURBANCE WILL ATTEMPT TO MOVE AROUND THE UPPER
RIDGING OVER THE GREAT LAKES FOR WED AND THURS...AND THE MODELS SHOW
DIFFERENCES IN EXACTLY WHERE IT MOVES. THE 12Z ECMWF SHOWS THIS
FEATURE SLIDING UNDER THE RIDGE TOWARDS THE SOUTHEAST...WHILE THE
12Z GFS WEAKENS AND FLATTENS THE RIDGE ENOUGH TO MOVE THE
DISTURBANCE ACROSS THE NORTHEAST. WITH THIS FEATURE BEING RATHER
WEAK AND MOISTURE STARVED...EITHER SCENARIO WOULD KEEP OUR REGION
DRY. MAX TEMPS WILL BE IN THE UPPER 60S TO LOW 70S FOR VALLEY
AREAS...WHICH IS NEAR TO SLIGHTLY ABOVE NORMAL.
BEHIND THAT WEAK UPPER LEVEL DISTURBANCE...BOTH MODELS SHOWS STRONG
RIDGING REESTABLISHING ITSELF ALONG THE EASTERN SEABOARD FOR FRIDAY
INTO SATURDAY. UNDER PLENTY OF SUNSHINE AND CONTINUED DRY
CONDITIONS...THIS SHOULD ALLOW MAX TEMPS TO REACH INTO THE 70S
ACROSS MOST OF THE REGION...WITH MID 70S FOR THE CAPITAL REGION AND
MID HUDSON VALLEY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FLYING CONDITIONS ARE CURRENTLY VFR OR HIGH END MVFR WITH
INCREASING CLOUDS ACROSS THE REGION. A COLD FRONT WILL CURRENTLY
MOVING ACROSS WESTERN NEW YORK.
A BAND OF STEADY RAINFALL AHEAD OF THE BOUNDARY IS PROGRESSING
ACROSS CENTRAL NY AND WILL REACH THE HUDSON VALLEY AND WESTERN NEW
ENGLAND TAF SITES LATER THIS EVENING...PROBABLY BY AROUND 01Z-02Z.
FLYING CONDITIONS WILL QUICKLY DROP TO MVFR WITHIN THE RAIN
SHOWERS...AND SOME IFR CONDITIONS ARE EXPECTED WITHIN HEAVIER
BURSTS THROUGH ABOUT 05Z-06Z OR SO. AFTERWARD...SOME LINGERING SHOWERS ARE
EXPECTED THROUGH ABOUT SUNRISE...BUT IFR CONDITIONS LOOK TO
CONTINUE DUE TO LOW CIGS.
FLYING CONDITIONS SHOULD IMPROVE BACK TO VFR ON SUNDAY MORNING AS
THE SHOWERS END...AND CIGS BEGIN TO CLEAR OUT. VFR CONDITIONS ARE
EXPECTED THROUGH THE DAY SUNDAY.
SOUTHERLY WINDS OF AROUND 10 KTS AHEAD OF THE RAINFALL WILL BECOME
WESTERLY LATER TONIGHT AS THE COLD FRONT CROSSES THE REGION. THERE
MAY BE A FEW HIGHER GUSTS...ESP WITHIN THE HEAVIER BURSTS OF
RAINFALL. ON SUNDAY...WESTERLY WINDS WILL CONTINUE TO BE AROUND 10
KTS WITHIN DAYTIME MIXING...AND A FEW HIGHER GUSTS ARE POSSIBLE AT
KALB/KPSF.
OUTLOOK...
SUN NIGHT-MON NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. PATCHY FG
LATE NIGHT/EARLY MORNING.
TUE-THU: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
WIDESPREAD PRECIPITATION TONIGHT INTO SUNDAY AS A COLD FRONT
APPROACHES AND CROSSES THE REGION. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
&&
.HYDROLOGY...
WIDESPREAD PRECIPITATION TONIGHT AS A COLD FRONT APPROACHES AND
CROSSES THE REGION. PRECIPITABLE WATERS VALUES ARE EXPECTED TO
INCREASE TO AROUND 1 1/2 INCHES AHEAD OF THE FRONTAL BOUNDARY WHICH
IS ABOUT 1 1/2 STANDARD DEVIATIONS ABOVE NORMAL. RAINFALL AMOUNTS OF
1 TO 1 1/2 INCHES ARE EXPECTED WITH LOCALLY HIGHER AMOUNTS OF 2 TO
POSSIBLY 3 INCHES. FLOODING OF RIVERS AND STREAMS IS NOT EXPECTED AT
THIS TIME...HOWEVER WITHIN BANK RISES OF SEVERAL FEET ARE POSSIBLE
ON MAJOR RIVERS. WHAT IS LIKELY IS PONDING OF WATER AND FLOODING OF
POOR DRAINAGE AND LOW LYING AREAS. CAN NOT RULE OUT ISOLATED FLASH
FLOODING.
THE UPPER LOW AND TROUGH AXIS WILL MOVE ACROSS THE REGION SUNDAY.
THE STEADY PRECIPITATION WILL TAPER OFF FROM SOUTHWEST TO
NORTHEAST DURING THE MORNING HOURS. HIGH PRESSURE WILL BEGIN TO
BUILD INTO THE REGION SUNDAY NIGHT AND IS THEN EXPECTED TO
DOMINATE THE WEATHER MUCH OF NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/FRUGIS
NEAR TERM...IAA/FRUGIS/11
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...IAA
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
404 AM EDT SUN SEP 22 2013
.SYNOPSIS...
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE BEGIN TO TAKE CONTROL OF THE WEATHER ACROSS THE
GREAT LAKES TODAY AND WILL PERSIST INTO THE UPCOMING WEEK. LAKE
EFFECT CLOUDS WILL SLOWLY BREAK UP TODAY WITH ALL AREAS BECOMING
MOSTLY CLEAR BY TONIGHT. HIGH TEMPERATURES WILL BE COOL AGAIN TODAY
AND REMAIN IN THE 60S. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
AND LOWER 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
LAKE EFFECT CLOUDS HAVE MOVED WELL INLAND THANKS TO A STRONG
TRAPPING SUBSIDENCE INVERSION AND A NNW LOW LEVEL WIND. SATELLITE
SHOWS A RATHER LARGE AREA OF STRATOCUMULUS AS FAR SOUTH AS MUNCIE
AT 07Z AND STILL EXPANDING SOUTHWARD. ONLY MODEL TO HAVE A DECENT
HANDLE ON THESE CLOUDS IS THE HRRR WITH RUC13 PLAYING CATCHUP.
DELTA T VALUES INTO THE MID TEENS OVER SOUTHERN LAKE MICHIGAN WITH
850MB TEMPS DOWN TO ABOUT +3C AND MID LAKE TEMP RUNNING AROUND
20C. LACK OF DEEP MOISTURE AND THE STRONG INVERSION SEEMS TO BE
KEEPING ANY SHOWERS FROM DEVELOPING PER REGIONAL RADAR MOSAIC.
WILL RELY ON SATELLITE AND HRRR TRENDS FOR CLOUD COVER THIS
MORNING WHILE KEEPING PCPN OUT OF FORECAST.
SHOULD SEE SUBSIDENCE AND VEERING LOW LEVEL WINDS HELP ERODE EASTERN
FLANK OF CLOUD SHIELD THIS MORNING. ALREADY SEEING A LITTLE BIT OF
THIS WITH THINNING AND A FEW BREAKS DEVELOPING ON SATELLITE OVER
SOUTH CENTRAL MI AND NE INDIANA AT 08Z. TRAJECTORIES SUGGEST CLOUDS
WILL PERSIST OVER WESTERN THIRD OF CWA THROUGH THE MORNING WITH A
LIKELY TREND TOWARD BECOMING CELLULAR WITH MORE BREAKS BY AFTERNOON.
THIS SEEMS REASONABLE GIVEN SHALLOW NATURE OF MOISTURE AND CLOUDS.
SKIES EXPECTED TO BECOME MOSTLY CLEAR TONIGHT WITH HIGH PRESSURE
MOVING OVERHEAD ALONG WITH UPPER LEVEL RIDGE.
TEMPS WILL BE COOL AGAIN TODAY WITH HIGHS ONLY REACHING THE LOW TO
MID 60S ACROSS THE AREA. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
TO LOWER 40S WITH CLEAR SKIES AND LIGHT WINDS. SIDED TOWARD COOLER
GUIDANCE NUMBERS GIVEN EXPECTED RADIATIONAL COOLING.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
SLOW WARMING TREND REMAINS IN STORE FOR MUCH OF THE UPCOMING WEEK AS
UPPER LEVEL RIDGING MOVES INTO THE REGION. TROUGH OVER THE PLAINS
WILL MOVE EAST WITH MAIN UPPER SUPPORT REMAINING WELL NORTH OF THE
AREA. MODELS DO SHOW AN ORPHANED TROUGH THAT MIGRATES ACROSS THE
LOWER GREAT LAKES TUES NGT/WEDS...BUT LIMITED FORCING AND MSTR WITH
THE FEATURE SHOULD KEEP AWAY ANY PRECIP.
UPPER FLOW WILL RESPOND TO DEEPENING TROUGH IN THE WESTERN STATES AS
RIDGING BUILDS ACROSS THE EASTERN PLAINS INTO THE GREAT LAKES INTO
AT LEAST FRIDAY WITH TEMPS CLIMBING TO ABOVE NORMAL LEVELS IN THE
MID 70S. FORECAST DETAILS FOR SATURDAY AND BEYOND REMAIN MUDDLED AS
DEEP TROUGH EJECTS TOWARDS THE REGION WITH MODELS CONTINUING TO VARY
ON TIMING/STRENGTH/IMPACT TO THE AREA. ALL MED RANGE MODELS LIFT
BULK OF THE ENERGY NE INTO THE UPPER PLAINS/NORTHERN GREAT LAKES
WITH SOUTHERN EXTENT OF THE ENERGY RATHER VARIABLE. GFS/GEFS REMAIN
MOST AGGRESSIVE WITH TROUGH SWEEPING ACROSS SAT NGT INTO SUNDAY WITH
SHOWERS/STORMS...ALTHOUGH PROBS FOR PRECIP WITH GEFS STILL 60% OR
LESS. 12Z RUN OF ECMWF HAD A RATHER DRAMATIC SHIFT WITH ENERGY
SHIFTING NORTH AND THEN WAVE DROPPING BACK INTO THE WESTERN GREAT
LAKES AS A CUT OFF UPPER LOW. 00Z SOLUTION HAS BACKED OFF FROM THIS
AND SIMPLY FLATTENS THE RIDGE ACROSS THE REGION WITH NO PRECIP.
CONFIDENCE LOW DURING THIS PERIOD...WARRANTING CONTINUED BUCKING OF
TRENDS TO ADD POPS BY CR ALLBLEND WHICH IS HEAVILY BIASED TOWARDS
THE GFS SOLUTIONS...THE WETTEST SOLUTION AS NOTED ABOVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 148 AM EDT SUN SEP 22 2013
SATELLITE SHOWS LAKE CLOUDS BEING PUSHED SOUTHEAST AND HAVE
REACHED KFWA THIS HOUR. SHALLOW MOISTURE OFF LAKES BEING TRAPPED
BELOW STRONG SUBSIDENCE INVERSION AND ADVECTING SOUTH.
TRAJECTORIES AND MODEL SOUNDINGS SUGGEST THESE CLOUDS WILL LIKELY
CONTINUE THROUGH THE NIGHT AND EXPAND FURTHER SOUTHWARD AS
WELL...ESSENTIALLY LOCKING IN ACROSS MUCH OF THE AREA. OBS
INDICATE MOST CIGS IN THE VFR RANGE WITH KSBN COMING IN AT 35HFT.
ONLY HIRES GUIDANCE TO REALLY CAPTURE THESE CLOUDS SEEMS TO BE THE
HRRR WHICH HOLDS THEM IN AT KFWA THROUGH DAYBREAK BEFORE ALLOWING
SUBSIDENCE AND LOW LEVEL VEERING WINDS TO BREAK UP EASTERN FLANK
OF CLOUDS. KSBN TO LIKELY SEE AT LEAST BROKEN VFR CLOUDS THROUGH
MID TO LATE MORNING UNTIL NORTHEAST FLOW AND SUBSIDENCE FINALLY
WIN OUT. REGARDLESS...VFR CONDITIONS EXPECTED WITH LIGHT WINDS
BECOMING NORTH TO NORTHEAST AT 4 TO 9 KNOTS SUNDAY AND BECOMING
LIGHT AND VARIABLE AGAIN SUNDAY NIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
152 AM EDT SUN SEP 22 2013
.SYNOPSIS...
ISSUED AT 150 AM EDT SUN SEP 22 2013
HIGH PRESSURE WAS TAKING CONTROL ACROSS THE GREAT LAKES AND WILL
PERSIST THROUGH MUCH OF THE UPCOMING WEEK. LAKE EFFECT CLOUDS WILL
SLOWLY BREAK UP ON SUNDAY WITH ALL AREAS BECOMING MOSTLY CLEAR BY
SUNDAY NIGHT. HIGH TEMPERATURES WILL BE COOL AGAIN TODAY AND
REMAIN IN THE 60S. LOWS TONIGHT WILL DROP INTO THE LOWER AND MID
40S.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 354 PM EDT SAT SEP 21 2013
BROKEN STRATOCU DECK IS CONTINUING TO EXPAND ACROSS THE AREA AS COLD
AIR ADVECTION CONTINUES. THE COLDEST PORTION OF THIS AIRMASS WILL
ADVECT OVERHEAD TONIGHT WHICH WILL ALLOW TEMPERATURES TO DROP INTO
THE MID 40S. THE EXCEPTION WILL BE IN WESTERN AREAS WHERE LAKE
EFFECT CLOUD COVER WILL KEEP TEMPERATURES IN THE UPPER 40S. WENT
WITH A BLEND OF THE BCSREF AND BCEURO FOR OVERNIGHT LOWS AS THEY
WERE BOTH ON THE WARMER SIDE OF GUIDANCE. HAVE ELECTED FOR OVERNIGHT
LOWS A FEW DEGREES HIGHER DUE TO CONCERN OF SCATTERED CLOUDCOVER
PERSISTING ACROSS THE AREA TONIGHT AS WELL AS SLIGHTLY HIGHER
FORECAST DEWPOINTS. STRATOCU DECK ACROSS WISCONSIN HAS BEEN VERY
PERSISTENT TODAY AND BOTH THE RAP AND HRRR SHOW LITTLE DISSIPATION
AS IT ADVECTS OUR WAY OVERNIGHT. ON THE OTHER HAND...THE LAST FEW
FRAMES OF VISIBLE SATELLITE MAY BE HINTING AT SOME DRY AIR
ENTRAINMENT ON THE WESTERN EDGE OF THIS DECK. RAP/HRRR/NAM ARE ALL
INDICATING POTENTIAL FOR LAKE EFFECT RAIN SHOWERS AFTER MIDNIGHT AS
A SHORTWAVE DROPS THROUGH MICHIGAN...BUT HAVE KEPT FORECAST DRY
GIVEN LOWERING/STRENGTHENING INVERSION...DRY AIR ABOVE 850 MB...AND
SHALLOW FORECAST CLOUD DEPTH.
SUNDAY WILL BE COOL AND MOSTLY SUNNY AS HIGH PRESSURE SLIDES ACROSS
THE GREAT LAKES AND CYCLONIC FLOW ALOFT COMES TO AN END. CU RULE
VALUES IN THE WEST INDICATE THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER FOR THE FIRST PORTION OF THE DAY...BUT EVEN THIS WILL COME TO
AN END BY MID DAY ONCE WARM AIR ADVECTION ARRIVES.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 354 PM EDT SAT SEP 21 2013
UPR LEVEL RIDGE OVER THE PLAINS THIS AFTN WILL MOVE EAST TO THE WRN
GRTLKS SUNDAY NIGHT. THIS RIDGE SHOULD BECOME NRLY STNRY OVER THE
GRTLKS MON-TUE AS A DEEP CUT-OFF LOW FORMS OVER SERN CANADA. STRONG
SHRTWV MOVG ONTO THE WEST COAST THIS AFTN IS EXPECTED TO MOVE EAST
TO THE MS VALLEY TUE. COMBINATION OF ENCOUNTER WITH STALLED RIDGE
AND SHEARING ASSOCIATED WITH ANOTHER STRONG SHRTWV MOVG INTO THE
MEAN WRN TROF WILL WEAKEN THE LEAD SHRTWV AS IT APPROACHES OUR AREA.
SHOULD BE SOME INCREASE IN MOISTURE/CLOUDINESS AS THIS SYSTEM MOVES
THROUGH THE AREA TUE NGT/WED BUT AIRMASS EXPECTED TO REMAIN STABLE
WITH RATHER WARM MID/UPR LEVELS SO KEPT FCST DRY THROUGH THIS
TIMEFRAME.
RIDGE SHOULD REBUILD OVER THE AREA THU-FRI AS THE NEXT STRONG SHRTWV
CURRENTLY LOCATED OVER THE GULF OF ALASKA MOVES ACROSS THE ROCKIES.
12Z MEDIUM RANGE MODELS CONT TO HAVE CONSIDERABLE DIFFERENCE ON
TIMING/EVOLUTION OF THE TROF BY SATURDAY WITH ECMWF SHEARING SYSTEM
NE ACROSS THE NRN PLAINS/UPR GRTLKS INTO MANITOBA/ONTARIO WHILE
GFS/GEFS MAINTAIN A STRONGER UPR TROF/SFC CDFNT MOVG EAST INTO THE
MID/UPR MS VALLEY. BOTH MODELS HAVE TRENDED TOWARD A MORE PERSISTENT
RIDGE NEXT WEEKEND ACROSS THE GRTLKS OVER THE PAST 24HRS SO PREFER
ECMWF FARTHER WEST SOLUTION IN THIS REGARD AND THUS KEPT FCST FOR
SAT DRY FOR NOW.
TEMPS SHOULD BE A BIT BLO NORMAL AT THE START OF THE PERIOD WITH
LOWS IN THE L-M40S AND HIGHS IN THE M-U60S MONDAY. A SLOW WARMING
TREND EXPECTED THROUGH THE WEEK AS UPR RIDGE BUILDS INTO THE AREA
WITH ABOVE NORMAL TEMPS MID-LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 148 AM EDT SUN SEP 22 2013
SATELLITE SHOWS LAKE CLOUDS BEING PUSHED SOUTHEAST AND HAVE
REACHED KFWA THIS HOUR. SHALLOW MOISTURE OFF LAKES BEING TRAPPED
BELOW STRONG SUBSIDENCE INVERSION AND ADVECTING SOUTH.
TRAJECTORIES AND MODEL SOUNDINGS SUGGEST THESE CLOUDS WILL LIKELY
CONTINUE THROUGH THE NIGHT AND EXPAND FURTHER SOUTHWARD AS
WELL...ESSENTIALLY LOCKING IN ACROSS MUCH OF THE AREA. OBS
INDICATE MOST CIGS IN THE VFR RANGE WITH KSBN COMING IN AT 35HFT.
ONLY HIRES GUIDANCE TO REALLY CAPTURE THESE CLOUDS SEEMS TO BE THE
HRRR WHICH HOLDS THEM IN AT KFWA THROUGH DAYBREAK BEFORE ALLOWING
SUBSIDENCE AND LOW LEVEL VEERING WINDS TO BREAK UP EASTERN FLANK
OF CLOUDS. KSBN TO LIKELY SEE AT LEAST BROKEN VFR CLOUDS THROUGH
MID TO LATE MORNING UNTIL NORTHEAST FLOW AND SUBSIDENCE FINALLY
WIN OUT. REGARDLESS...VFR CONDITIONS EXPECTED WITH LIGHT WINDS
BECOMING NORTH TO NORTHEAST AT 4 TO 9 KNOTS SUNDAY AND BECOMING
LIGHT AND VARIABLE AGAIN SUNDAY NIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT UNTIL 3 AM CDT EARLY THIS MORNING FOR
INZ003.
MI...BEACH HAZARDS STATEMENT UNTIL 4 AM EDT EARLY THIS MORNING FOR
MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
LMZ043-046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...BENTLEY
LONG TERM...JT
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
159 AM EDT SUN SEP 22 2013
.SYNOPSIS...
A STRONG COLD FRONT AND UPPER LEVEL LOW WILL APPROACH THE STATE
OVERNIGHT AND MOVE THROUGH THE FORECAST AREA ON SUNDAY. THE UPPER
LOW WILL THEN LINGER EAST OF THE REGION THROUGH MIDWEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
2 AM UPDATE...ADJUSTED THE SKY COVER TO ACCOUNT FOR SOME PARTIAL
CLEARING DOWNEAST ESPECIALLY ALONG THE COAST PER THE LATEST IR
SATL IMAGERY AND THE OBS. A LARGE AREA OF RAIN W/POCKETS OF
HEAVIER RAINFALL MOVING ACROSS EASTERN NYS INTO VT AND NH AS OF
05Z SFC ANALYSIS. BACKED UP THE TIMING OF THE RAINFALL BY A FEW
HRS GIVEN THIS ANALYSIS. THE LATEST RUN OF THE HRRR AND THE NAM
DOING QUITE WELL W/THE PLACEMENT. INCREASED THE WINDS/GUSTS
OVERNIGHT INTO EARLY SUNDAY W/LLVL JET OF 50 KTS PER THE LATEST
LAPS AND NAM SOUNDINGS. TEMPERATURES ALSO NEEDED ADJUSTMENT UPWARD
PER THE LATEST OBS SHOWING READINGS IN THE LOW TO MID 60S.
PREVIOUS DISCUSSION... FORECAST CHALLENGE FOR NEAR TERM WILL BE
FRONTAL SYSTEM DUE TO ARRIVE WITH RAIN LATE TONIGHT AND SUNDAY. IN
THE MEANTIME, A SOUTHERLY FLOW HAS ADVECTED IN MARINE STRATUS
ALONG MUCH OF THE COAST WITH MAINLY SUNNY SKIES ELSEWHERE. EXPECT
CLOUDS TO INCREASE ACROSS THE REMAINDER OF THE REGION LATER THIS
EVENING INTO THE OVERNIGHT. SOME LIGHT RAIN AND PATCHY DRIZZLE
WILL BE POSSIBLE BY THE LATE EVENING INTO THE EARLY PART OF THE
OVERNIGHT WITH HEAVIER AND STEADIER RAIN ARRIVING FROM WEST TO
EAST LATE TONIGHT INTO SUNDAY MORNING.
SUNDAY WILL FEATURE WET AND BREEZY CONDITIONS. EXPECT
RAIN, MODERATE TO EVEN HEAVY AT TIMES. THE HEAVIEST RAIN WILL FALL
IN THE MORNING OVER WESTERN PORTIONS OF THE CWA AND IN THE
AFTERNOON OVER EASTERN AREAS. OVERALL, FORECAST MODELS HAVE COME
INTO BETTER AGREEMENT SO UTILIZED A BLENDED SOLUTION OF THE 12Z
GFS, GEM REG, NAM, AND RFC GRIDS FOR QPF. RAINFALL TOTALS LOOK
TO GENERALLY BE AROUND AN INCH BY LATE DAY. HOWEVER MODELS
CONTINUE TO DEPICT SOME ELEVATED INSTABILITY SO KEPT THE MENTION
OF ISOLATED THUNDER IN THE GRIDS WHICH COULD RESULT IN LOCALLY
HIGHER RAINFALL AMOUNTS OF UP TO AN INCH AND A HALF OR MORE.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
THE SURFACE LOW AND COLD FRONT WILL MOVE EAST OF THE REGION EARLY
SUNDAY NIGHT...WITH THE UPPER LOW STARTING TO CROSS THE REGION
OVERNIGHT. THE MOST EXTENSIVE SHOWERS WILL OCCUR ACROSS EASTERN
AND NORTHERN PORTIONS OF THE FORECAST AREA DURING THE EVENING IN
ADVANCE OF THE COLD FRONT. SHOWERS WILL DIMINISH IN THE WAKE OF
THE COLD FRONT ACROSS CENTRAL AND DOWNEAST AREAS. HOWEVER...SHOWERS
WITH THE UPPER LOW WILL PERSIST ACROSS NORTHERN AREAS SUNDAY
NIGHT. THE UPPER LOW WILL BEGIN TO MOVE EAST OF THE REGION MONDAY.
THE BEST CHANCES FOR SHOWERS AND MOST EXTENSIVE CLOUD COVER MONDAY
WILL OCCUR ACROSS NORTHERN AREAS...WITH GENERALLY PARTLY SUNNY
SKIES DOWNEAST. WITH A BLOCKING PATTERN ALOFT...UNCERTAINTY THEN
EXISTS REGARDING HOW QUICKLY THE UPPER LOW MOVES EAST MONDAY
NIGHT THROUGH TUESDAY NIGHT AND THE TIMING OF ANY DISTURBANCES
WHICH MIGHT ROTATE AROUND THE UPPER LOW. GENERALLY EXPECT THE
MOST EXTENSIVE CLOUD COVER AND SLIGHT CHANCE OF SHOWERS ACROSS
NORTHERN AREAS MONDAY NIGHT INTO TUESDAY. THE COLD POOL
ALOFT...WILL SUPPORT DIURNAL CLOUD DEVELOPMENT ACROSS THE
REMAINDER OF THE FORECAST AREA. SURFACE HIGH PRESSURE WILL BEGIN
TO SLOWLY BUILD EAST TUESDAY NIGHT. TEMPERATURES WILL BE AT BELOW
NORMAL LEVELS MONDAY/TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE EXTENDED PERIOD WILL BE QUIET AS A RIDGE OF HIGH PRESSURE WILL
SETTLE ACROSS THE NORTHEAST MID-LATE NEXT WEEK. AN UPPER LOW OVER
THE CANADIAN MARITIMES WILL KEEP SOME CLOUDS AROUND, MAINLY OVER
NORTHEASTERN AREAS, ON WEDNESDAY, BUT MOSTLY CLEAR SKIES WILL BE THE
RULE MOST OF THE TIME. OVERNIGHT TEMPERATURES COULD BE A LITTLE CHILLY
GIVEN LIGHT WINDS AND CLEAR SKIES; HAVE TRENDED JUST A TAD COOLER
THAN GUIDANCE, BUT LATER SHIFTS WILL NEED TO MONITOR TO DETERMINE
IF LOWS MAY NEED TO BE LOWERED MORE. DAYTIME HIGHS WILL BE
PLEASANT AND SEASONABLE, WITH MOST LOCATIONS TOPPING OUT IN THE
60S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: FOR THE NORTHERN TERMINALS, VFR WILL DROP TO MVFR AND
EVENTUALLY IFR OVERNIGHT AS LOW CLOUDS AND RAIN MOVE IN. SUNDAY
WILL BE WET AND BREEZY WITH CONTINUING IFR CONDITIONS. FOR KBHB
AND KBGR, MVFR LOWERS TO IFR TONIGHT WITH LIFR EVEN POSSIBLE BY
SUNDAY. SOUTHERLY WINDS INCREASE TONIGHT INTO SUNDAY MORNING AHEAD
OF A COLD FRONT WITH WIND SHEAR LIKELY BEING A CONCERN TONIGHT
INTO SUNDAY. THE 00Z KCAR SOUNDING HAD A SOUTH WIND OF 43 KT AT
2500 FT AGL AND WIND SPEEDS OF 50 KTS ARE EXPECTED OVERNIGHT AT 2K
FT AGL.
SHORT TERM: MVFR/IFR CONDITIONS ARE EXPECTED ACROSS THE ENTIRE
REGION EARLY SUNDAY NIGHT. CONDITIONS WILL IMPROVE TO VFR LEVELS
DOWNEAST LATER SUNDAY NIGHT WITH OCCASIONAL MVFR CONDITIONS
PERSISTING ACROSS NORTHERN AREAS. OCCASIONAL MVFR CONDITIONS ARE
POSSIBLE ACROSS NORTHERN AREAS MONDAY INTO TUESDAY...WITH
GENERALLY VFR CONDITIONS DOWNEAST. VFR CONDITIONS ARE EXPECTED
ACROSS THE ENTIRE REGION TUESDAY NIGHT. VFR CONDITIONS ARE
EXPECTED TO CONTINUE THROUGH MID WEEK AS HIGH PRESSURE SETTLES
OVER THE REGION.
&&
.MARINE...
NEAR TERM: SEAS HAVE BEEN SLOWLY BUILDING THIS EVENING AND ARE NOW
AROUND 4 FT AT THE EASTERN MAINE SHELF. THE SEAS WILL CONTINUE
TO BUILD AND SHOULD REACH SCA LEVELS BY LATE TONIGHT AND
CONTINUE INTO SUNDAY. WINDS MAY ABATE FOR A TIME BY LATE SUNDAY
WITH SEAS STAYING UP HOWEVER.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED SUNDAY
NIGHT THROUGH MONDAY NIGHT...WITH CONDITIONS BELOW SMALL CRAFT
ADVISORY LEVELS TUESDAY/TUESDAY NIGHT. VISIBILITIES WILL BE REDUCED
IN SHOWERS EARLY SUNDAY NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
359 AM EDT SUN SEP 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A CONFLUENT NW
FLOW ALF OVER THE UPR GREAT LKS BTWN UPR RDG IN THE PLAINS AND DEEP
UPR TROF EXTENDING FM HUDSON BAY/WRN QUEBEC S THRU THE APPALACHIANS.
SINCE THE PATTERN IS SLOWLY PROGRESSIVE...00Z RAOBS SHOWED 12Z-24Z
H3/H5 HGT RISES UP TO 100M FM NW ONTARIO INTO THE WRN GREAT LKS. THE
LARGER SCALE SUBSIDENCE ASSOCIATED WITH THESE DYANMICS ARE
SUPPORTING A SFC HI PRES FM NW ONTARIO THRU WRN LK SUP AND INTO WI.
BUT SINCE THE 00Z YPL RAOB SHOWS MSTR TRAPPED WITHIN LLVL THERMAL
TROF DIPPING INTO THE GREAT LKS AND UNDER SUBSIDENCE INVRN NEAR
H85...THERE ARE AREAS OF LK EFFECT SC OVER PORTIONS OF UPR MI IN
SLOWLY VEERING LLVL NLY FLOW E OF THE RDG AXIS. H85 TEMPS AS LO AS
-3C OVER THE E HALF OF LK SUP ARE SUPPORTING ISOLD LK EFFECT -SHRA
AS WELL IN THAT AREA. THE WRN EDGE OF THE SC IS RIGHT UP TO RDG AXIS
NEAR IWD AT 06Z. TO THE W OF THIS LINE...MUCH DRIER AIR SHOWN ON THE
00Z INL RAOB IS BRING CLR SKIES. H85 TEMPS WARM FAIRLY STEADILY TO
THE W...WITH THE 00Z TEMP UP TO 13C AT ABERDEEM SDAKOTA AND BISMARCK
IN THE LARGE SCALE SLY FLOW W OF THE RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT CLD/-SHRA TRENDS.
FOCUS FOR TNGT SHIFTS TO THE PROSPECT OF MORE FROST WITH THE HI PRES
MOVING GRADUALLY TO THE E IN THE SLOWLY PROGRESSIVE UPR PATTERN.
TODAY...SFC HI PRES RDG AXIS IS PROGGED TO DRIFT SLOWLY E THRU THE
DAY...REACHING THE ERN CWA BY 00Z MON. WITH LARGER SCALE SUBSIDENCE
WARMING THE H85 TEMPS/STRENGTHENING INVRN...EXPECT ANY LINGERING LK
EFFECT -SHRA TO DIMINISH EARLY TODAY. AS OBSVD EARLY THIS MRNG...
PASSAGE OF RDG AXIS/MORE ACYC LLVL FLOW AS WELL AS DAYTIME HEATING/
MIXING SHOULD RESULT IN AN EROSION OF LINGERING LK CLDS AS WELL. THE
SC WL BE MOST RESILIENT OVER THE NCENTRAL THIS MRNG WITH UPSLOPE NNE
WIND COMPONENT...WITH LINGERING LLVL MSTR/THERMAL TROFFING TO THE E
OF THE ENCROACHING RDG AXIS ALLOWING FOR AT LEAST MORE DAYTIME CU/SC
OVER THE ERN CWA INTO THE AFTN. SUBSIDENCE WARMING/RETURN SLY FLOW
TO THE W OF THE HI PRES IS PROGGED TO LIFT H85 TEMPS NEAR 10C AT IWD
BY 00Z MON. WITH A GOOD DEAL OF SUNSHINE IN THIS AREA...EXPECT HI
TEMPS TO REACH 60 TO 65 OVER THE W AWAY FM LK MODERATION.
TNGT...THE SFC RDG AXIS IS FCST TO DRIFT ONLY SLOWLY E OF THE SAULT
TNGT. WITH CLEAR SKIES AND PWAT 0.33 TO 0.50 INCH /AS LO AS 60 PCT
OF NORMAL/...EXPECT A FAVORABLE SETUP FOR A SHARP DIURNAL TEMP FALL
OVER THE E HALF OF THE CWA...WHERE THE PRES GRADIENT IS FCST TO BE
RATHER FLAT AND H925 WINDS NO MORE THAN ABOUT 10 KTS THRU 12Z MON.
WL TEND TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS OVER THE
INTERIOR E HALF...WHERE FROST IS LIKELY. OVER THE W...A STRONGER
RETURN FLOW WITH S H925 WINDS UP TO 20-25 KTS WL MITIGATE THE
DIURNAL DROP. PLAN TO ISSUE A FROST ADVY FOR THE E AND CENTRAL
PORTION OF THE CWA. BUT WL WAIT UNTIL THE CURRENT ADVY EXPIRES AT
12Z TO ISSUE THE HEADLINE/STATEMENT TO AVOID CONFUSION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
A DRY AND WARMER THAN NORMAL START TO FALL IS EXPECTED THIS WEEK.
THIS IS DUE TO THE UPPER TROUGH THAT MOVED THROUGH THE AREA THIS
MORNING SLOWLY MOVING THROUGH THE CANADIAN MARITIMES THIS WEEK.
THIS WILL SETUP A BLOCK AND KEEP THE UPSTREAM CONDITIONS LOCKED IN
PLACE FOR MUCH OF THE UPCOMING WORK WEEK. FOR THE UPPER GREAT LAKES
REGION...THIS MEANS AN UPPER RIDGE WILL BE OVER THE AREA WITH A
SURFACE HIGH JUST TO THE EAST OF THE AREA. THUS...EXPECT SOUTHERLY
FLOW TO PULL WARMER AIR NORTH AND LEAD TO A WEEK OF ABOVE NORMAL
TEMPERATURES AND REALLY NICE LATE SEPTEMBER WEATHER.
EXPECT MOSTLY CLEAR THROUGH MUCH OF THE WEEK...ALTHOUGH THERE
ARE SOME HINTS OF DIURNAL CU DEVELOPING OVER THE EAST WITH SOME
MOISTENING OFF LAKE MICHIGAN WHEN THE SOUTHERLY FLOW DEVELOPS. DID
TRY TO SHOW THAT POTENTIAL ON MONDAY/TUESDAY FOR A PERIOD DURING
PEAK AFTERNOON HEATING. HIGHS MOST DAYS THIS WEEK WILL BE IN THE
UPPER 60S AND LOWER 70S THIS WEEK WITH LOWS IN THE 40S/50S.
MAIN CONCERNS FOR WEATHER WILL BE A SHORTWAVE EXITING THE CENTRAL
PLAINS ON TUESDAY...BUT IS SHOULD FALL APART BEFORE REACHING THE
AREA AND KEEP THINGS DRY. 00Z GFS DOES TRY TO PUT SOME PRECIP
INTO IRONWOOD TUESDAY AFTERNOON/EVENING...BUT WITH 00Z NAM/GEM/ECMWF
AND OUR WRF-ARW KEEPING IT DRY...WILL FOLLOW THAT IDEA. ONLY AFFECT
IT SHOULD HAVE ON THE U.P. IS SOME MID-HIGH CLOUDS...MAINLY OVER THE
WESTERN THIRD OF THE CWA.
ANOTHER UPPER TROUGH WILL EXIT THE ROCKIES ON FRIDAY AND THIS ONE
ALSO LOOKS TO STRUGGLE WITH THE BLOCKING UPPER RIDGE IN THE GREAT
LAKES REGION. MODELS HAVE DIFFERING SOLUTIONS ON HOW THIS SYSTEM
WILL EVOLVE HEADING INTO THE WEEKEND...SO WILL FOLLOW A GENERAL
CONSENSUS OF PRECIPITATION CHANCE INCREASING FRIDAY NIGHT INTO
SATURDAY AS THE UPPER TROUGH SWEEPS EAST-NORTHEAST THROUGH THE
AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EDT SUN SEP 22 2013
VFR CONDITIONS WILL PREVAIL THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW
AS SFC HIGH PRES RIDGE BUILDS OVER THE AREA. INITIALLY...THERE WILL
BE LAKE EFFECT STRATOCU OFF LAKE SUPERIOR OVERNIGHT. CLOUD BASES
SHOULD BE ABOVE 3KFT...THOUGH THERE MAY BE BRIEF MVFR CIGS AT KSAW
AS NORTHERLY FLOW IS MORE SHARPLY UPSLOPING THERE. IN ADDITION...
THERE MAY BE A FEW LAKE EFFECT -SHRA AROUND KSAW FOR A PORTION OF
THE NIGHT. ANY LINGERING STRATOCU WILL DISSIPATE LATE MORNING/EARLY
AFTN...LEAVING CLEAR SKIES FOR THE REMAINDER OF THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE CURRENTLY OVER LAKE SUPERIOR WILL SLIDE EAST OVER
THE LOWER GREAT LAKES AND EASTERN ONTARIO TONIGHT AND THEN REMAINING
STATIONARY THROUGH MUCH OF THE UPCOMING WORK WEEK. WHILE THIS
OCCURS...SOUTHERLY FLOW WILL INCREASE SLIGHTLY STARTING
TONIGHT...BUT EXPECT THE WINDS TO BE BELOW 20KTS FOR MOST OF
THE PERIOD. THE PERIODS OF THE STRONGEST WINDS LOOK TO BE MONDAY
NIGHT (AS AN AREA OF LOW PRESSURE MOVES OUT OF THE PLAINS AND
DISSIPATES) AND ON THURSDAY NIGHT INTO FRIDAY NIGHT (AS ANOTHER LOW
MOVES OUT OF THE CENTRAL PLAINS AND INTO WESTERN ONTARIO). DURING
THOSE TIME PERIODS...THERE COULD BE SLIGHTLY HIGHER GUSTS TO
25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR MIZ004-
011.
FREEZE WARNING UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR MIZ002-
009-010-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...SRF
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1212 AM EDT SUN SEP 22 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND CROSS THE
REGION SUNDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH EARLY NEXT
WEEK. LOW PRESSURE WILL PASS SOUTH OF THE REGION WEDNESDAY WITH HIGH
PRESSURE RETURNING LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1205 AM SUNDAY...SO FAR ONLY VERY LIGHT RAIN HAS SPREAD OVER
ERN NC. RGNL RDRS SHOW MORE WIDESPREAD AND HEAVIER PRECIP TO THE W
MAINLY JUST NE OF SFC LOW ON COLD FRONT. MDLS SHOW THIS LOW TRACKING
E TWRD CST OVERNIGHT SO WIDESPREAD RAIN WILL OVERSPREAD REGION.
ALTHOUGH INSTAB IS VERY WEAK MAY BE JUST ENOUGH FOR ONE OR TWO
LIGHTNING STRIKES SO INCLUDED SLIGHT CHC TSRA. BASED ON RDR TRENDS
THINK HEAVIEST RAINFALL WILL BE OVER NRN TIER BUT ALL AREAS SHLD SEE
DECENT RAINFALL AND WILL CONT CAT POPS. MILD TEMPS WITH AREA
REMAINING ON WARM SIDE OF COLD FRONT...LOWS MAINLY UPR 60S TO LOWER
70S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AS OF 300 PM SAT...MODELS INDICATE SLIGHTLY SLOWER FRONTAL
PROGRESSION WITH NAM AND ECMWF INDICATING STRONGER SFC WAVE ON SRN
END. HAVE ADJUSTED FCST SLIGHTLY TOWARD THIS SOLUTION WITH HIGHER
POPS LINGERING ALONG COAST THROUGH MORNING...DIMINISHING W TO E
DURING AFTN. MOS BLEND FOR TEMPS WITH PCPN AND CLOUD COVER EXPECTED
TO HOLD MAX TEMPS IN MID TO UPR 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
ANY LINGERING PRECIP WILL GRADUALLY BE MOVING OFF THE COAST SUNDAY
NIGHT, WITH COOLER/DRIER AIR FILTERING INTO THE REGION VIA SFC
HIGH PRES RIDGING SOUTH FROM THE GREAT LAKES AND DEVELOPING NW
FLOW ALOFT. LOWS WILL DIP INTO THE MID 50S INLAND BY EARLY MON
MORNING AND LOW TO MID 60S COAST UNDER GRADUALLY CLEARING SKIES.
PLEASANT WEATHER CONDITIONS WILL HIGHLIGHT THE EARLY WEEK PERIOD WITH
SFC HIGH AND UPPER RIDGE BUILDING OVER THE AREA. TEMPS WILL BE A
BIT BLO NORMAL WITH GOOD RADIATIONAL COOLING AT NIGHT, BUT WITH
LOTS OF SUNSHINE BOTH MONDAY AND TUESDAY
MODEL SOLUTIONS CONTINUE TO VARY WITH A SYSTEM (OR LACK THEREOF)
MOVING OFF THE SE COAST DURING MIDWEEK. WILL CONTINUE TO FOLLOW
WPC RECOMMENDATIONS FOR A BLEND OF ENSEMBLE MEANS WHICH MORE
CLOSELY FOLLOW THE DETERMINISTIC ECMWF SOLUTION, JUST NOT AS
AMPLIFIED. SO WITH THAT IN MIND WILL KEEP POPS AT SLIGHT TO LOW
THRU MIDWEEK AND FAVOR SOUTHERN AREAS FOR THE HIGHER PRECIP
CHANCES. CLOUD COVER SPREADING NORTH ON THE FRINGES OF THE
SOUTHERN SYSTEM WILL HELP HOLD HIGH TEMPS IN THE 70S ON
WEDNESDAY.
PRECIP CHANCES LINGER THRU WED NIGHT AND INTO EARLY THU ESPECIALLY
ALONG SE COASTAL AREAS. SHUD BEGIN TO SEE DECREASING CLOUDS THU
AFTN AS SFC LOW PRES MOVES WELL OFF THE SE COAST AND MID LEVEL
DRYING SWEEPS THRU THE FCST AREA. RIDGING AT THE SURFACE AND ALOFT
ENSURES DRY WEATHER RETURNING TO THE REGION LATE IN THE WEEK.
TEMPS WILL TREND BACK TO NEAR AND ABOVE NORMAL LEVELS INTO EARLY
NEXT WEEKEND.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1205 AM SUNDAY...WIDESPREAD RAIN WILL OVERSPREAD REGION NEXT
SEVERAL HRS. AS THIS RAIN REACHES AREA EXPECT MAINLY MVFR VSBYS WITH
CIGS GRAD LOWERING TO IFR...MAY DELAY IFR CIGS A BIT BASED ON
UPSTREAM OBS. RAIN AND LOW CIGS WILL CONT INTO SUN MORN THEN SHLD
SEE PRECIP END WITH CIGS GRAD IMPROVING TO MVFR BY MIDDAY AND POSS
VFR LATE.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
POOR FLYING CONDITIONS SUNDAY EVENING WILL GRADUALLY IMPROVE THRU
EARLY MONDAY MORNING AS DRIER AIR WORKS INTO THE AREA. OTHER THAN
THE TYPICAL THREAT FOR SHALLOW EARLY MORNING FOG...GOOD FLYING
WEATHER EXPECTED MONDAY/TUESDAY WITH HIGH PRESSURE BUILDING INTO
THE AREA. WILL BEGIN TO SEE INCREASING CLOUDS, RAIN CHANCES AND
THREAT FOR SUB-VFR CONDITIONS WEDNESDAY INTO WED NIGHT AS LOW
PRESSURE MOVES SOUTH OF THE AREA. EXPECTED IMPROVING FLYING
CONDITIONS ON TUESDAY AS HIGH PRESSURE RETURNS.
&&
.MARINE...
SHORT TERM /THROUGH SUNDAY/...
AS OF 1205 AM SUN...PER LATEST 3KM HRRR AND RUC MODELS...EXPECT THE
CURRENT SOUTHERLY WINDS AT 10 TO 15 KNOTS TO BECOME SW LATE TONIGHT.
SPEEDS MAY INCREASE TO 15 TO 20 KNOTS OVER THE SOUTHERN WATERS AND
SURFACE LOW TRACKS INLAND LATE TONIGHT. SEAS SHOULD REMAIN RIGHT
AROUND 3 FEET WITH 10 SECOND SWELL PERIODS. ADJUSTED WINDS FOR
SLIGHTLY SLOWER FRONTAL/SFC LOW PASSAGE ON SUNDAY. EXPECT MAINLY
S/SE WINDS THRU SUN MORN WITH DIR BECOMING NE LATE AND INCREASING TO
15 TO 20 KTS MOST WTRS BY EVENING.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
CAA SURGE WILL PUSH NORTH WINDS AND SEAS TO NEAR SMALL CRAFT
ADVISORY LEVELS SUNDAY NIGHT INTO EARLY MONDAY. WINDS WILL THEN
GRADUALLY DIMINISH AND VEER TO THE NE/E AND SEAS SLOWLY SUBSIDE AS
HIGH PRESSURE BUILDS INTO THE MARINE AREA FROM THE NORTH THRU
TUESDAY. WINDS WILL BACK AGAIN TO THE NE/N AND INCREASE AS LOW
PRESSURE PASSES TO THE SOUTH WED NIGHT AND THURSDAY BUT NOT
EXPECTING ANY FLAGS WILL BE NEEDED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...RF
SHORT TERM...JBM
LONG TERM...BTC
AVIATION...RF/BM
MARINE...RF/CTC/BTC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
338 AM CDT SUN SEP 22 2013
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MAIN CHALLENGES WILL BE TEMPERATURES TODAY AND PRECIP CHANCES
TONIGHT INTO MONDAY. 00Z MODELS ARE IN DECENT AGREEMENT THROUGH
THIS PERIOD AND WILL USE A BLEND FOR DETAILS. 500MB LOW WILL
PROPAGATE FROM THE SOUTHWEST CONUS INTO THE CENTRAL PLAINS. THIS
WILL DEVELOP SOUTHWEST FLOW ALOFT BY TONIGHT...CONTINUING INTO
MONDAY. ALTHOUGH LOW LEVEL FLOW WILL SIGNIFICANTLY INCREASE...IT
WILL BE FROM MORE OF A SOUTHEAST DIRECTION...PROMOTING THE VERY
DRY LOW LEVEL AIRMASS. THIS WILL BE A HINDRANCE ON PRECIP
POTENTIAL. FOR TONIGHT...MODELS INDICATE A STRONG 850MB JET 40-50
KNOTS...WITH WEAK INSTABILITY QUICKLY ADVECTING NORTHWARD ALONG
THE WESTERN EDGE OF THIS FEATURE. COULD BE AN ISOLATED STORM
(ACROSS THE FAR WESTERN FA)...BUT INSTABILITY SEEMS TO BE IN AN
UNFAVORABLE AREA. FOR MONDAY...HIGHER MOISTURE AND LOW LEVEL
CONVERGENCE REMAINS WEST OF THE REGION...WITH AREAS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA (POSSIBLY PORTIONS OF THE DEVILS
LAKE BASIN) MOST LIKELY TO EXPERIENCE SHOWERS.
MAX TEMPS TODAY SHOULD RANGE FROM THE UPPER 60S INTO THE UPPER
70S. THE 06Z RAP IS SHOWING A STRONG WARM FRONT MOVING INTO THE
SW FA...WITH TEMPS INTO THE UPPER 80S. MOST MODELS SHOW THIS
FEATURE...BUT NOT QUITE AS FAR NORTH BY 00Z MONDAY. WILL HAVE TO
MONITOR...FOR NOW STUCK WITH LOW TO MID 80S FOR THIS AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MONDAY NIGHT-TUESDAY NIGHT...THE LOW LEVEL CONVERGENCE SHIFTS
EASTWARD AND THROUGH THE FA. THE LOW LEVEL AIRMASS SHOULD REMAIN
DRY AS THE MAJORITY OF MODELS SHOW THE MAIN UPPER LOW WILL BE WELL
SOUTH OF THE REGION. ANTICIPATE A BAND OF SHOWERS THAT WILL WEAKEN
AS IT MOVES EAST AND FINALLY DIES BY TUESDAY AFTERNOON.
TEMPERATURES WILL DEPEND ON CLOUD COVER...BUT GENERALLY SLIGHTLY
ABOVE NORMAL VALUES.
WEDNESDAY-SATURDAY...500MB SOUTHWEST FLOW ALOFT WILL CONTINUE TO
ALLOW ABOVE NORMAL TEMPERATURES INTO THE NORTHERN PLAINS THRU THE
END OF THE WEEK. TIMING AND PLACEMENT OF SHORT WAVE ENERGY TO
TRACK FROM THE ROCKIES ACROSS THE DAKOTAS STILL UNCERTAIN...
THOUGH BEST CHANCES FOR MEASURABLE RAINFALL WILL BE WITH FROPA ON
FRIDAY. POPS IN THE FORECAST FOR WED AND THURS ARE LESS CERTAIN
ESPECIALLY FROM RED RIVER VALLEY AND EASTWARD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM CDT SAT SEP 21 2013
EXPECT GUSTY SOUTH-SOUTHEAST WIND TO DEVELOP MID MORNING
SUNDAY...WITH SUSTAINED IN THE RED RIVER VALLEY AND ERN ND IN THE
15 TO 25 KT RANGE WITH GUSTS 25-30 KTS PSBL. LIGHTER WINDS IN
BEMIDJI. CLEAR SKY WITH SOME CIRRUS MOVING IN THE AFTN AND AT
NIGHT. SOUTHEAST WINDS TO STAY UP PAST SUNSET SUNDAY EVENING DUE
TO TIGHT PRESSURE GRADIENT AHD OF NEXT LOW MOVING NORTH.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
345 AM CDT SUN SEP 22 2013
.SHORT TERM /NOW THROUGH MONDAY/...UPPER LEVEL TROUGH MOVING
ACROSS NORTHERN CA INTO NEVADA WILL DEEPEN AND MIGRATE
EAST/SOUTHEAST INTO THE FOUR CORNERS REGION WHILE RIDGE BUILDS
OVER NORTH CENTRAL TEXAS. AN ELONGATED POSITIVE TILTED TROUGH OVER
THE TEXAS REGION WILL GRADUALLY SHIFT EASTWARD ADVECTING DRIER AIR
ACROSS SOUTH TEXAS FROM THE NORTH. SURFACE LOW OVER THE GULF
WATERS WILL STRENGTHEN THE GRADIENT ALONG THE RIO GRANDE VALLEY
AND KEEP A NORTH TO NORTHEAST FLOW ACROSS MUCH OF THE CWA TODAY.
WINDS WILL INCREASE BETWEEN 20 TO 25 MPH ESPECIALLY ALONG THE
COAST. AS DRIER AIR MOVES INTO S TEXAS...CLEAR SKIES WILL PREVAIL
ACROSS THE CWA WHILE AT THE COAST MOISTURE RAP AROUND THIS LOW
WILL INCREASE THE CLOUD COVER BETWEEN A FEW TO SCATTERED CLOUD
LAYER ALONG THE COAST. THE MOISTURE CONTENT WILL NOT BE VERY
SHALLOW WHICH WILL LIMIT CONVECTION TO DEVELOP. HIGH TEMPERATURES
TODAY WILL TREND 2 TO 3 DEG WARMER COMPARED TO YESTERDAYS
TEMPERATURES.
AS THIS LOW CONTINUES TO MOVE FURTHER FROM THE COAST OF TEXAS THIS
AFTERNOON..SFC GRADIENT WILL GRADUALLY RELAX AND REDUCE THE NORTH TO
NORTHEAST WINDS ACROSS THE AREA AND THE CHANCES OF RAIN LOWERS. A FEW
SHOWERS CAN NOT BE RULED OUT BUT WILL REMAIN OVER THE OFFSHORE WATERS
TODAY. TONIGHT...NORTHERLY FLOW WILL DIMINISH ACROSS THE CWA AN REMAIN
LIGHT AND VARIABLE DUE TO THE WEAKENING SURFACE GRADIENT. LOW TEMPS
WILL REMAIN WELL BELOW NORMAL...WITH THE WESTERN PORTION REACHING
THE MID TO UPPER 60S WHILE ALONG THE COAST REMAINING IN THE LOW 70S.
MONDAY...SURFACE LOW BEGINS TO MOVE PARALLEL TO THE TEXAS COAST INTO
THE NORTHWEST GULF WHILE DRIER AIR INDICATED BY THE NAM AND THE GFS
AT 1000 TO 500 MB RH LAYER MOVES INTO THE CWA FROM THE NORTHWEST. AS
THE DRY AIR INFILTRATES INTO THE CWA...THE CHANCE OR RAIN LOWERS
EVEN MORE TO LESS THAN 10 PERCENT ACROSS THE CWA. HIGH TEMPERATURES
WILL CONTINUE TO WARM INTO NEAR NORMAL TEMPERATURES FOR SEPTEMBER
WITH HIGHS NEAR THE MID 90S ALONG THE INTERNATIONAL BORDER. NORTH
WINDS WILL DECOUPLE QUICKLY AFTER SUNSET.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...500MB TROUGH ACROSS
THE NORTH CENTRAL UNITED STATES MONDAY WILL SHIFT EASTWARD TUESDAY
AS A 500MB RIDGE BUILDS ACROSS THE SOUTHERN PLAINS. NORTHWEST FLOW
ALOFT WILL CONTINUE TO PROVIDE SUBSIDENCE ACROSS SOUTH TEXAS
TUESDAY INTO WEDNESDAY. LOW TO MID LEVEL MOISTURE IS EXPECTED TO
RETURN ACROSS THE RIO GRANDE VALLEY THURSDAY INTO FRIDAY AS A
500MB TROUGH DEVELOPS ACROSS THE WESTERN UNITED STATES AND THE
UPPER LEVEL RIDGE ACROSS TX SHIFTS EASTWARD. SURFACE LOW PRESSURE
IS PROGGED TO DEVELOP ACROSS THE CENTRAL PLAINS FRIDAY AHEAD OF
THE UPPER LEVEL TROUGH ACROSS THE WESTERN U.S. BRINGING A WEAK
COLD FRONT TOWARDS CENTRAL TX SATURDAY. THIS WILL PROVIDE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE WEEKEND AS MOISTURE
POOLS ALONG AND AHEAD OF THE FRONT AS THE FRONT MOVES INTO SOUTH
TX SATURDAY INTO SUNDAY.
&&
.MARINE...
NOW THROUGH MONDAY...MARINE CONDITIONS REMAIN DETERIORATED FOR
MUCH OF THE SHORT TERM FORECAST. LATEST OBSERVATION SHOWS SEAS
BUILDING NEAR 9 FEET OVER THE GULF WATERS DUE TO THE SURFACE LOW
PRESSURE OVER THE GULF OF MX. THIS LOW WILL STRENGTHEN THE
GRADIENT ALONG THE GULF WATERS AND INCREASE WINDS BETWEEN 20 TO 25
KNOTS AND GUSTS UP TO 30 KNOTS AT TIMES. SEAS WILL BUILD TODAY
INCREASING CLOSE TO 10 FEET THROUGH THE DAY. THE SEAS BEGIN TO
LOWER OVER THE NEAR SHORE WATERS AS THE CENTER OF THE LOW BEGINS
TO MOVE FURTHER EAST EARLY TONIGHT. HOWEVER...A NORTHEAST FETCH
WILL KEEP SEAS HIGHER THROUGH THE EVENING OVER THE GULF SO THE SCA
HAS BEEN EXTENDED FOR THE WHOLE MARINE AREA WITH THE EXCEPTION OF
THE LAGUNA MADRE. ON THE BAY...CONDITIONS WILL BE MARGINAL TO
SMALL CRAFT ADVISORY BUT IT WILL LIKELY BE FOR AN HOUR AND QUICKLY
LOWER THE WINDS. THE NORTHEAST WINDS OVER THE OFFSHORE WATERS WILL
CONTINUE TO KEEP SEAS HIGH AS THE LOW PRESSURE MOVES NORTHWARD SO
EXTENDED THE SCA FOR THE OFFSHORE THROUGH MIDNIGHT. THE SEAS WILL
GRADUALLY LOWER TO SCEC BY EARLY MORNING MONDAY AND IMPROVE UNTIL
THE END OF THE DAY MONDAY WITH SEAS BETWEEN 2 TO 4 FEET. AN
ISOLATED SHOWER WILL BE POSSIBLE BUT WILL NOT LAST LONG AND
PRODUCE BRIEF DOWNPOURS.
MONDAY NIGHT THROUGH THURSDAY...LIGHT TO MODERATE NORTH TO
NORTHEAST WINDS ACROSS THE COASTAL WATERS MON NIGHT WILL BACK TO
THE WEST ON TUESDAY AS THE LOW PRESSURE ACROSS THE WESTERN GULF OF
MEXICO MOVES NORTHWARD. LIGHT WEST TO NORTHWEST WINDS SHOULD
PREVAIL ACROSS THE WESTERN GULF WEDNESDAY BEFORE FINALLY SHIFTING
TO THE SOUTHEAST ON THURSDAY AS LOW PRESSURE MOVES INTO THE
NORTHERN PLAINS AND THE LOW PRESSURE ACROSS THE NORTHERN GULF OF
MEXICO WEAKENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 84 72 87 72 / 10 10 10 0
BROWNSVILLE 86 70 90 70 / 10 10 10 0
HARLINGEN 87 69 90 70 / 10 10 10 0
MCALLEN 89 68 92 71 / 10 10 10 0
RIO GRANDE CITY 89 68 92 68 / 10 10 10 0
SOUTH PADRE ISLAND 83 74 85 75 / 10 10 10 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT MONDAY FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/61/VEGA
AREA FORECAST DISCUSSION
NWS MIAMI FL
957 AM EDT SUN SEP 22 2013
.UPDATE...
LOW LEVEL MOISTURE CONTINUES TO INCREASE THIS MORNING AS THE
SURFACE HIGH PRESSURE HAS SHIFTED TO THE EAST WITH COLD FRONT
MOVING INTO THE FLORIDA PANHANDLE. THIS PROCESS WILL EVOLVE
THROUGH THE AFTERNOON WITH FORECAST SOUNDINGS SHOWING PWAT
INCREASING FROM NEAR 1.5 INCHES TO A RANGE OF 1.7-1.85 BY LATE IN
THE DAY. LOW LEVEL CU HAS ALREADY BEGUN TO DEVELOP IN THIS
MOISTENING ENVIRONMENT AND A FEW SHRA SHOWING UP ON RADAR ACROSS
THE FAR SOUTH PENINSULA. THE LATEST HRRR RUN INDICATES SCATTERED
CONVECTION TAKING SHAPE BY 17Z AND THEN CONTINUING TO DEVELOP AS
THE CELLS MOVE TO THE NORTH-NORTHEAST THROUGH THE AFTERNOON. SO
THE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE AT THIS TIME AND NO
MAJOR CHANGES ARE PLANNED. HOWEVER, WILL NEED TO TAKE A CLOSER
LOOK AT OVERNIGHT POPS FOR THE AFTERNOON PACKAGE AS THE 12Z MODEL
GUIDANCE BECOMES AVAILABLE BUT THE CURRENT HRRR BEGINS TO HINT AT
GULF DEVELOPMENT IN THE 01-02Z TIME FRAME AND THIS ALSO WOULD BE ON
TARGET WITH THE CURRENT FORECAST.
KOB
&&
.PREV DISCUSSION... /ISSUED 940 AM EDT SUN SEP 22 2013/
AVIATION...
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MUCH OF THE 24 HR
PERIOD OVER THE TAF SITES. THE LOW-LEVEL FLOW WILL STEADILY VEER
TOWARD THE SOUTHWEST THROUGH THE PERIOD. THE BEST CHANCE FOR SHOWERS
WILL BE LATER THIS AFTERNOON/EVENING ACROSS THE NORTHERN AREAS FROM
LAKE OKEECHOBEE TO SITE PBI...WHICH COULD RESULT IN PERIODS WITH SUB
VFR CONDITIONS IN AND AROUND ANY SHRA/TSTM THAT DEVELOPS.
OVERNIGHT...THE BEST CHANCE FOR SHOWERS WILL REMAIN ALONG THE GULF
COAST AS A FRONTAL BOUNDARY STALLS NORTH OF THE AREA AND PLENTY OF
MOISTURE OVERSPREADS THE REGION FROM THE SOUTH. /85
PREV DISCUSSION... /ISSUED 347 AM EDT SUN SEP 22 2013/
.WET WEATHER ON THE WAY FOR SOUTH FLORIDA THROUGH MIDDLE OF THIS WEEK...
SHORT TERM...
HIGH PRESSURE OVER THE WESTERN ATLANTIC WATERS WILL DISSIPATE
TODAY ALLOWING FOR A COLD FRONT OVER THE SOUTHEAST UNITED STATES
TO MOVE SOUTH INTO NORTH FLORIDA. THIS WILL ALLOW FOR THE STEERING
FLOW OVER SOUTH FLORIDA TO BE SOUTHERLY TODAY BRINGING IN SOME LOW
LEVEL MOISTURE TO THE AREA. SO ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON OVER SOUTH FLORIDA
WITH THE BEST COVERAGE OVER THE NORTHERN AREAS.
THE COLD FRONT WILL CONTINUE TO SLOWLY MOVE SOUTH TONIGHT AND
SHOULD BE OVER CENTRAL FLORIDA ON MONDAY. THIS WILL SWING THE
STEERING FLOW TO A SOUTHWEST DIRECTION OVER SOUTH FLORIDA ON
MONDAY...AND ALLOW FOR DEEP TROPICAL MOISTURE TO WORK INTO THE
AREA FROM THE CARIBBEAN SEA. SO WILL KEEP THE LIKELY POPS IN PLACE
OVER SOUTH FLORIDA ON MONDAY.
THE FRONT WILL THEN STALL OUT OVER CENTRAL FLORIDA MONDAY NIGHT
INTO WEDNESDAY KEEPING THE SOUTHWEST STEERING FLOW IN PLACE OVER
THE AREA ALONG WITH THE DEEP TROPICAL MOISTURE. SO WILL CONTINUE
THE LIKELY POPS OVER SOUTH FLORIDA FOR TUESDAY AND WEDNESDAY.
THE DEEP TROPICAL MOISTURE WILL ALSO ALLOW FOR THE POSSIBILITY OF
HEAVY RAINFALL OVER SOUTH FLORIDA EARLY TO MIDDLE PART OF THIS
WEEK. MORE ON THIS IN THE HYDRO SECTION BELOW.
LONG TERM...
A STRONG HIGH PRESSURE SYSTEM IS FORECAST BY THE LONG RANGE MODELS
TO DEVELOP OVER THE MID ATLANTIC STATES AND EXTEND SOUTHWEST INTO
THE SOUTHEAST UNITED STATES. THIS HIGH WILL PUSH THE STATIONARY
FRONT OVER CENTRAL FLORIDA SOUTHWARD THROUGH SOUTH FLORIDA LATE
THIS WEEK AND INTO THE FLORIDA STRAITS NEXT WEEKEND. SO THE DEEP
TROPICAL MOISTURE OVER SOUTH FLORIDA WILL GET PUSH SOUTH INTO THE
FLORIDA STRAITS THIS WEEKEND WITH DRY AIR OVER THE SOUTHEAST
UNITED STATES WORKING INTO THE AREA. SO THE POPS LATE THIS WEEK
WILL BE IN THE SCATTERED RANGE BEFORE DROPPING DOWN TO ISOLATED
RANGE NEXT WEEKEND...EXCEPT LOW END SCATTERED FOR THE WEST COAST
METRO AREAS OF SOUTH FLORIDA.
MARINE...
THE WINDS WILL BE 10 TO 15 KNOTS THROUGH EARLY THIS WEEK AS THE
WINDS SWING FROM A SOUTHERLY DIRECTION TODAY TO A SOUTHWEST
DIRECTION BY MONDAY. THIS WILL KEEP THE SEAS IN THE ATLANTIC
WATERS AT 1 TO 3 FEET WHILE THE GULF WATERS WILL BE AT 2 FEET OR
LESS. SO BOATING CONDITIONS SHOULD BE GOOD OUTSIDE OF THE SHOWERS
AND THUNDERSTORMS OVER SOUTH FLORIDA WATERS.
HYDROLOGY...
THE LATEST MODELS ARE STILL SHOWING THE PWAT VALUES TO BE 2.2 TO
2.4 INCHES OVER SOUTH FLORIDA FOR EARLY TO MIDDLE PART OF THIS
WEEK. THIS MEANS THAT THERE IS THE POTENTIAL OF HEAVY RAINFALL
ACROSS SOUTH FLORIDA DURING THIS TIME. SO HAVE KEPT THE HEAVY
RAINFALL WORDING IN THE ZONES FOR MONDAY THROUGH WEDNESDAY. AT
THIS TIME...RAINFALL TOTALS ARE EXPECTED TO BE BETWEEN 2 TO 4
INCHES ACROSS THE AREA. HOWEVER...IF ANY TRAINING OF SHOWERS AND
THUNDERSTORMS SETS UP OVER THE AREA THEN THESE RAINFALL AMOUNTS
WILL BE MUCH HIGHER.
METRO COLLIER COUNTY HAS SEEN CLOSE TO 10 INCHES OF RAINFALL FOR
THE MONTH OF SEPTEMBER. THIS AMOUNT OF RAINFALL HAS MADE THE
GROUNDS OVER METRO COLLIER COUNTY VERY SATURATED. SO WILL
CONTINUE TO MONITOR THE LATEST MODEL RUNS ON RAINFALL AMOUNTS OVER
METRO COLLIER COUNTY THROUGH MIDDLE PART OF THIS WEEK TO SEE IF A
FLOOD WATCH WILL BE NEEDED FOR METRO COLLIER COUNTY IN LATER
FORECAST PACKAGES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 90 76 89 76 / 40 40 60 50
FORT LAUDERDALE 90 78 89 78 / 30 30 60 50
MIAMI 90 78 89 78 / 20 20 60 50
NAPLES 89 76 87 77 / 20 40 70 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
650 AM EDT SUN SEP 22 2013
.SYNOPSIS...
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE BEGIN TO TAKE CONTROL OF THE WEATHER ACROSS THE
GREAT LAKES TODAY AND WILL PERSIST INTO THE UPCOMING WEEK. LAKE
EFFECT CLOUDS WILL SLOWLY BREAK UP TODAY WITH ALL AREAS BECOMING
MOSTLY CLEAR BY TONIGHT. HIGH TEMPERATURES WILL BE COOL AGAIN TODAY
AND REMAIN IN THE 60S. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
AND LOWER 40S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
LAKE EFFECT CLOUDS HAVE MOVED WELL INLAND THANKS TO A STRONG
TRAPPING SUBSIDENCE INVERSION AND A NNW LOW LEVEL WIND. SATELLITE
SHOWS A RATHER LARGE AREA OF STRATOCUMULUS AS FAR SOUTH AS MUNCIE
AT 07Z AND STILL EXPANDING SOUTHWARD. ONLY MODEL TO HAVE A DECENT
HANDLE ON THESE CLOUDS IS THE HRRR WITH RUC13 PLAYING CATCHUP.
DELTA T VALUES INTO THE MID TEENS OVER SOUTHERN LAKE MICHIGAN WITH
850MB TEMPS DOWN TO ABOUT +3C AND MID LAKE TEMP RUNNING AROUND
20C. LACK OF DEEP MOISTURE AND THE STRONG INVERSION SEEMS TO BE
KEEPING ANY SHOWERS FROM DEVELOPING PER REGIONAL RADAR MOSAIC.
WILL RELY ON SATELLITE AND HRRR TRENDS FOR CLOUD COVER THIS
MORNING WHILE KEEPING PCPN OUT OF FORECAST.
SHOULD SEE SUBSIDENCE AND VEERING LOW LEVEL WINDS HELP ERODE EASTERN
FLANK OF CLOUD SHIELD THIS MORNING. ALREADY SEEING A LITTLE BIT OF
THIS WITH THINNING AND A FEW BREAKS DEVELOPING ON SATELLITE OVER
SOUTH CENTRAL MI AND NE INDIANA AT 08Z. TRAJECTORIES SUGGEST CLOUDS
WILL PERSIST OVER WESTERN THIRD OF CWA THROUGH THE MORNING WITH A
LIKELY TREND TOWARD BECOMING CELLULAR WITH MORE BREAKS BY AFTERNOON.
THIS SEEMS REASONABLE GIVEN SHALLOW NATURE OF MOISTURE AND CLOUDS.
SKIES EXPECTED TO BECOME MOSTLY CLEAR TONIGHT WITH HIGH PRESSURE
MOVING OVERHEAD ALONG WITH UPPER LEVEL RIDGE.
TEMPS WILL BE COOL AGAIN TODAY WITH HIGHS ONLY REACHING THE LOW TO
MID 60S ACROSS THE AREA. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
TO LOWER 40S WITH CLEAR SKIES AND LIGHT WINDS. SIDED TOWARD COOLER
GUIDANCE NUMBERS GIVEN EXPECTED RADIATIONAL COOLING.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
SLOW WARMING TREND REMAINS IN STORE FOR MUCH OF THE UPCOMING WEEK AS
UPPER LEVEL RIDGING MOVES INTO THE REGION. TROUGH OVER THE PLAINS
WILL MOVE EAST WITH MAIN UPPER SUPPORT REMAINING WELL NORTH OF THE
AREA. MODELS DO SHOW AN ORPHANED TROUGH THAT MIGRATES ACROSS THE
LOWER GREAT LAKES TUES NGT/WEDS...BUT LIMITED FORCING AND MSTR WITH
THE FEATURE SHOULD KEEP AWAY ANY PRECIP.
UPPER FLOW WILL RESPOND TO DEEPENING TROUGH IN THE WESTERN STATES AS
RIDGING BUILDS ACROSS THE EASTERN PLAINS INTO THE GREAT LAKES INTO
AT LEAST FRIDAY WITH TEMPS CLIMBING TO ABOVE NORMAL LEVELS IN THE
MID 70S. FORECAST DETAILS FOR SATURDAY AND BEYOND REMAIN MUDDLED AS
DEEP TROUGH EJECTS TOWARDS THE REGION WITH MODELS CONTINUING TO VARY
ON TIMING/STRENGTH/IMPACT TO THE AREA. ALL MED RANGE MODELS LIFT
BULK OF THE ENERGY NE INTO THE UPPER PLAINS/NORTHERN GREAT LAKES
WITH SOUTHERN EXTENT OF THE ENERGY RATHER VARIABLE. GFS/GEFS REMAIN
MOST AGGRESSIVE WITH TROUGH SWEEPING ACROSS SAT NGT INTO SUNDAY WITH
SHOWERS/STORMS...ALTHOUGH PROBS FOR PRECIP WITH GEFS STILL 60% OR
LESS. 12Z RUN OF ECMWF HAD A RATHER DRAMATIC SHIFT WITH ENERGY
SHIFTING NORTH AND THEN WAVE DROPPING BACK INTO THE WESTERN GREAT
LAKES AS A CUT OFF UPPER LOW. 00Z SOLUTION HAS BACKED OFF FROM THIS
AND SIMPLY FLATTENS THE RIDGE ACROSS THE REGION WITH NO PRECIP.
CONFIDENCE LOW DURING THIS PERIOD...WARRANTING CONTINUED BUCKING OF
TRENDS TO ADD POPS BY CR ALLBLEND WHICH IS HEAVILY BIASED TOWARDS
THE GFS SOLUTIONS...THE WETTEST SOLUTION AS NOTED ABOVE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM EDT SUN SEP 22 2013
CLOUDS HAVE BEGUN TO DISSIPATE IN LAST FEW HOURS AND EXPECT THIS
TREND TO CONTINUE AS SUBSIDENCE IS FINALLY TAKING CONTROL WITH
HIGH PRESSURE MOVING INTO AREA. KSBN MAY SEE AN OCCASIONAL BKN CIG
BUT WILL BE VFR IF IT DOES OCCUR. WINDS GENERALLY UNDER 10 KNOTS
THROUGH THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1148 AM EDT SUN SEP 22 2013
.UPDATE...
ISSUED AT 1147 AM EDT SUN SEP 22 2013
CONTINUE TO TRACK THE LATEST SATELLITE AND RADAR TRENDS...WHICH SHOW
ONLY SOME IMPROVEMENT TO THE LINGERING MID CLOUDS ACROSS MUCH OF THE
CWA. FAVORABLE NNE WINDS CONTINUE TO STREAM A FEW BROKEN LINES OF
SHOWERS/DRIZZLE OVER MAINLY ALGER AND DELTA COUNTY LATE THIS
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A CONFLUENT NW
FLOW ALF OVER THE UPR GREAT LKS BTWN UPR RDG IN THE PLAINS AND DEEP
UPR TROF EXTENDING FM HUDSON BAY/WRN QUEBEC S THRU THE APPALACHIANS.
SINCE THE PATTERN IS SLOWLY PROGRESSIVE...00Z RAOBS SHOWED 12Z-24Z
H3/H5 HGT RISES UP TO 100M FM NW ONTARIO INTO THE WRN GREAT LKS. THE
LARGER SCALE SUBSIDENCE ASSOCIATED WITH THESE DYANMICS ARE
SUPPORTING A SFC HI PRES FM NW ONTARIO THRU WRN LK SUP AND INTO WI.
BUT SINCE THE 00Z YPL RAOB SHOWS MSTR TRAPPED WITHIN LLVL THERMAL
TROF DIPPING INTO THE GREAT LKS AND UNDER SUBSIDENCE INVRN NEAR
H85...THERE ARE AREAS OF LK EFFECT SC OVER PORTIONS OF UPR MI IN
SLOWLY VEERING LLVL NLY FLOW E OF THE RDG AXIS. H85 TEMPS AS LO AS
-3C OVER THE E HALF OF LK SUP ARE SUPPORTING ISOLD LK EFFECT -SHRA
AS WELL IN THAT AREA. THE WRN EDGE OF THE SC IS RIGHT UP TO RDG AXIS
NEAR IWD AT 06Z. TO THE W OF THIS LINE...MUCH DRIER AIR SHOWN ON THE
00Z INL RAOB IS BRING CLR SKIES. H85 TEMPS WARM FAIRLY STEADILY TO
THE W...WITH THE 00Z TEMP UP TO 13C AT ABERDEEM SDAKOTA AND BISMARCK
IN THE LARGE SCALE SLY FLOW W OF THE RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT CLD/-SHRA TRENDS.
FOCUS FOR TNGT SHIFTS TO THE PROSPECT OF MORE FROST WITH THE HI PRES
MOVING GRADUALLY TO THE E IN THE SLOWLY PROGRESSIVE UPR PATTERN.
TODAY...SFC HI PRES RDG AXIS IS PROGGED TO DRIFT SLOWLY E THRU THE
DAY...REACHING THE ERN CWA BY 00Z MON. WITH LARGER SCALE SUBSIDENCE
WARMING THE H85 TEMPS/STRENGTHENING INVRN...EXPECT ANY LINGERING LK
EFFECT -SHRA TO DIMINISH EARLY TODAY. AS OBSVD EARLY THIS MRNG...
PASSAGE OF RDG AXIS/MORE ACYC LLVL FLOW AS WELL AS DAYTIME HEATING/
MIXING SHOULD RESULT IN AN EROSION OF LINGERING LK CLDS AS WELL. THE
SC WL BE MOST RESILIENT OVER THE NCENTRAL THIS MRNG WITH UPSLOPE NNE
WIND COMPONENT...WITH LINGERING LLVL MSTR/THERMAL TROFFING TO THE E
OF THE ENCROACHING RDG AXIS ALLOWING FOR AT LEAST MORE DAYTIME CU/SC
OVER THE ERN CWA INTO THE AFTN. SUBSIDENCE WARMING/RETURN SLY FLOW
TO THE W OF THE HI PRES IS PROGGED TO LIFT H85 TEMPS NEAR 10C AT IWD
BY 00Z MON. WITH A GOOD DEAL OF SUNSHINE IN THIS AREA...EXPECT HI
TEMPS TO REACH 60 TO 65 OVER THE W AWAY FM LK MODERATION.
TNGT...THE SFC RDG AXIS IS FCST TO DRIFT ONLY SLOWLY E OF THE SAULT
TNGT. WITH CLEAR SKIES AND PWAT 0.33 TO 0.50 INCH /AS LO AS 60 PCT
OF NORMAL/...EXPECT A FAVORABLE SETUP FOR A SHARP DIURNAL TEMP FALL
OVER THE E HALF OF THE CWA...WHERE THE PRES GRADIENT IS FCST TO BE
RATHER FLAT AND H925 WINDS NO MORE THAN ABOUT 10 KTS THRU 12Z MON.
WL TEND TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS OVER THE
INTERIOR E HALF...WHERE FROST IS LIKELY. OVER THE W...A STRONGER
RETURN FLOW WITH S H925 WINDS UP TO 20-25 KTS WL MITIGATE THE
DIURNAL DROP. PLAN TO ISSUE A FROST ADVY FOR THE E AND CENTRAL
PORTION OF THE CWA. BUT WL WAIT UNTIL THE CURRENT ADVY EXPIRES AT
12Z TO ISSUE THE HEADLINE/STATEMENT TO AVOID CONFUSION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
A DRY AND WARMER THAN NORMAL START TO FALL IS EXPECTED THIS WEEK.
THIS IS DUE TO THE UPPER TROUGH THAT MOVED THROUGH THE AREA THIS
MORNING SLOWLY MOVING THROUGH THE CANADIAN MARITIMES THIS WEEK.
THIS WILL SETUP A BLOCK AND KEEP THE UPSTREAM CONDITIONS LOCKED IN
PLACE FOR MUCH OF THE UPCOMING WORK WEEK. FOR THE UPPER GREAT LAKES
REGION...THIS MEANS AN UPPER RIDGE WILL BE OVER THE AREA WITH A
SURFACE HIGH JUST TO THE EAST OF THE AREA. THUS...EXPECT SOUTHERLY
FLOW TO PULL WARMER AIR NORTH AND LEAD TO A WEEK OF ABOVE NORMAL
TEMPERATURES AND REALLY NICE LATE SEPTEMBER WEATHER.
EXPECT MOSTLY CLEAR THROUGH MUCH OF THE WEEK...ALTHOUGH THERE
ARE SOME HINTS OF DIURNAL CU DEVELOPING OVER THE EAST WITH SOME
MOISTENING OFF LAKE MICHIGAN WHEN THE SOUTHERLY FLOW DEVELOPS. DID
TRY TO SHOW THAT POTENTIAL ON MONDAY/TUESDAY FOR A PERIOD DURING
PEAK AFTERNOON HEATING. HIGHS MOST DAYS THIS WEEK WILL BE IN THE
UPPER 60S AND LOWER 70S THIS WEEK WITH LOWS IN THE 40S/50S.
MAIN CONCERNS FOR WEATHER WILL BE A SHORTWAVE EXITING THE CENTRAL
PLAINS ON TUESDAY...BUT IS SHOULD FALL APART BEFORE REACHING THE
AREA AND KEEP THINGS DRY. 00Z GFS DOES TRY TO PUT SOME PRECIP
INTO IRONWOOD TUESDAY AFTERNOON/EVENING...BUT WITH 00Z NAM/GEM/ECMWF
AND OUR WRF-ARW KEEPING IT DRY...WILL FOLLOW THAT IDEA. ONLY AFFECT
IT SHOULD HAVE ON THE U.P. IS SOME MID-HIGH CLOUDS...MAINLY OVER THE
WESTERN THIRD OF THE CWA.
ANOTHER UPPER TROUGH WILL EXIT THE ROCKIES ON FRIDAY AND THIS ONE
ALSO LOOKS TO STRUGGLE WITH THE BLOCKING UPPER RIDGE IN THE GREAT
LAKES REGION. MODELS HAVE DIFFERING SOLUTIONS ON HOW THIS SYSTEM
WILL EVOLVE HEADING INTO THE WEEKEND...SO WILL FOLLOW A GENERAL
CONSENSUS OF PRECIPITATION CHANCE INCREASING FRIDAY NIGHT INTO
SATURDAY AS THE UPPER TROUGH SWEEPS EAST-NORTHEAST THROUGH THE
AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1147 AM EDT SUN SEP 22 2013
PESKY LOW VFR TO HIGH END MVFR CEILINGS ARE HAVING A DIFFICULT TIME
EXITING TODAY. EVEN IWD WHICH HAD BEEN CLEAR FROM 11Z-15Z QUICKLY
FILLED BACK WITH MVFR CEILINGS AS LINGERING LOW LEVEL MOISTURE AND
WSW WINDS WRAPPED CLOUDS BACK INTO THE AREA. WILL CONTINUE TO SEE
SLOW IMPROVEMENT IN THE CLOUD COVER THROUGH THE AFTERNOON
HOURS...WITH LITTLE TO NO CLOUDS REMAINING BY SUNSET. THE MAIN
CONCERN OVERNIGHT WILL BE INCREASING WINDS BETWEEN THE SLOWLY
EXITING HIGH PRESSURE SYSTEM...AND AN ELONGATED AREA OF LOW PRESSURE
ACROSS THE PLAINS. LLWS WILL REMAIN A POSSIBILITY AT IWD WITH
25-35KT WINDS POSSIBLE JUST ABOVE THE SFC FROM 03-15Z MONDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE CURRENTLY OVER LAKE SUPERIOR WILL SLIDE EAST OVER
THE LOWER GREAT LAKES AND EASTERN ONTARIO TONIGHT AND THEN REMAINING
STATIONARY THROUGH MUCH OF THE UPCOMING WORK WEEK. WHILE THIS
OCCURS...SOUTHERLY FLOW WILL INCREASE SLIGHTLY STARTING
TONIGHT...BUT EXPECT THE WINDS TO BE BELOW 20KTS FOR MOST OF
THE PERIOD. THE PERIODS OF THE STRONGEST WINDS LOOK TO BE MONDAY
NIGHT (AS AN AREA OF LOW PRESSURE MOVES OUT OF THE PLAINS AND
DISSIPATES) AND ON THURSDAY NIGHT INTO FRIDAY NIGHT (AS ANOTHER LOW
MOVES OUT OF THE CENTRAL PLAINS AND INTO WESTERN ONTARIO). DURING
THOSE TIME PERIODS...THERE COULD BE SLIGHTLY HIGHER GUSTS TO
25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 8 AM EDT /7 AM CDT/
MONDAY FOR MIZ004>007-010>014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1124 AM EDT SUN SEP 22 2013
LATEST UPDATE...
MARINE
.SYNOPSIS...
ISSUED AT 323 AM EDT SUN SEP 22 2013
HIGH PRESSURE WILL MOVE OVER THE REGION THROUGH THE FIRST PART OF
THIS WEEK. THIS SYSTEM WILL BRING SUNNY AND MILD DAYS AND CHILLY
NIGHTS. FROST WILL BE POSSIBLE TONIGHT NORTH OF I-96.
TEMPERATURES WILL SLOWLY WARM INTO THE LATTER PART OF THE WEEK. THE
NEXT CHANCE OF RAIN SHOULD HOLD OFF UNTIL SATURDAY.
&&
.UPDATE...
ISSUED AT 1040 AM EDT SUN SEP 22 2013
IT IS CLEAR TO ME (PUN INTENDED) THE SKIES WILL IN FACT NOT BE
CLEAR ANY TIME SOON. THE AREA OF STRATOCUMULUS CLOUDS CONTINUES TO
EXPAND SOUTHWARD OVER THE SOUTHERN AND SOUTHWEST CWA. GIVEN THE
LACK OF ANY TREND FOR THE CLOUDS TO BREAK UP SOON I HAVE UPDATED
THE ZONES TO KEEP THE CLOUDS AROUND INTO EARLY THIS AFTERNOON. THE
LATEST MODEL RUNS... LIKE THE RAP AND THE OUTGOING LONGWAVE
RADIATION FEATURE ON THE HRRR 12Z RUN SUGGEST THE CLEARING WILL BE
MORE IN THE 2 TO TO 5 PM TIME FRAME. SO THAT IS WHERE I NOW HAVE
IT IN THE GRIDS. IF THE CLOUDS DO HANG AROUND INTO MID AFTERNOON
THE HIGHS WILL ONLY BE THE 50S... I LOWERED THE AFTERNOON TEMPS
ABOUT 2 DEGREES BUT THAT MAY NOT BE ENOUGH. WE SHALL SEE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
FIRST CHALLENGE IN THE SHORT TERM WAS DETERMINING WHEN THE CLOUDS
OVER THE REGION WILL FINALLY CLEAR. THEN FROST/FREEZE POTENTIAL
BECOMES A CONCERN TONIGHT.
THE UPPER LOW OVER WESTERN QUEBEC CONTINUES TO BRING CHILLY NW FLOW
OVER THE REGION. THE COMBINATION OF MOISTURE WRAPPING AROUND THIS
LOW AND LAKE DELTA T/S AROUND 18...HAS HELD IN A SC DECK INTO EARLY
THIS MORNING. HOWEVER AS THE LOW SHIFTS TO EASTERN QUEBEC LATER
TODAY...SURFACE AND UPPER RIDGING MOVES INTO THE WESTERN GREAT LAKES
ALONG WITH WARM ADVECTION ALOFT BY AFTERNOON. SO BELIEVE THE CLOUDS
WILL ERODE FAIRLY QUICKLY ONCE THE SUN IS UP...AND MOSTLY SUNNY
SKIES CAN BE EXPECTED CWA-WIDE BY LATE MORNING.
THE SURFACE RIDGE WILL SIT OVER THE CWA TONIGHT BRINGING CLEAR SKIES
AND LIGHT WINDS. THIS WILL BE IDEAL RADIATION CONDITIONS AND
FROST/FREEZE HEADLINES WILL BE POSTED ACROSS THE NORTHERN CWA.
PATCHY FROST WILL BE POSSIBLE OVER THE SOUTHERN HALF TOO...BUT IT
SHOULD BE ISOLATED ENOUGH TO NOT WARRANT HEADLINES.
LITTLE WEATHER TO SPEAK OF FOR MONDAY AND TUESDAY. THE UPPER FLOW
REMAINS FAIRLY AMPLIFIED WHICH WILL KEEP THE PATTEN BLOCKED AND KEEP
THE SURFACE AND UPPER RIDGE NEARBY. TEMPS SHOULD MODERATE EACH
DAY...TO 70 TO 75 BY TUESDAY. FROST SHOULD LESS OF A THREAT MONDAY
NIGHT WITH SE LOW LEVEL FLOW DEVELOPING.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
WARM AND DRY IS THE MAIN MESSAGE IN THE LONG TERM PERIOD AS A HIGH
AMPLITUDE UPPER LEVEL RIDGE DOMINATES OUR WEATHER. THIS FEATURE WILL
LEAD TO TEMPERATURES ABOUT 10 DEGREES ABOVE NORMAL WITH HIGHS IN THE
MID TO UPPER 70S AND LOWS IN THE 50S.
HAVE REMOVED THE LOW CHANCE OF SHOWERS FOR FRIDAY NIGHT BUT LEFT
THEM IN FOR SATURDAY DUE TO THE WET LOOK OF THE GFS. THE EURO ON THE
OTHER HAND IS A DAY SLOWER WITH THE FRONT AND SUGGESTS THE BETTER
RAIN CHANCES WOULD HOLD OFF UNTIL SATURDAY NIGHT OR SUNDAY. THIS MAY
BE MORE REASONABLE GIVEN THE HIGHLY AMPLIFIED UPPER RIDGE SO PERHAPS
IN FUTURE FORECASTS WE CAN GO DRY ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 732 AM EDT SUN SEP 22 2013
HIGH CONFIDENCE WIDESPREAD VFR CONDITIONS TODAY AND TONIGHT. NORTH
WINDS UNDER 10 KNOTS TODAY BECOMING LIGHT EAST TONIGHT.
&&
.MARINE...
ISSUED AT 1124 AM EDT SUN SEP 22 2013
THE SMALL CRAFT ADVISORY HAS EXPIRED. WINDS ARE NOW GENERALLY
UNDER 10 KNOTS AND WAVE FOR THE MOST PART UNDER 2 FEET.
&&
.HYDROLOGY...
ISSUED AT 323 AM EDT SUN SEP 22 2013
NO RAIN IS EXPECTED UNTIL NEXT WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ039-040.
FROST ADVISORY FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ037-038-
044>046-051.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JK
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1040 AM EDT SUN SEP 22 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 323 AM EDT SUN SEP 22 2013
HIGH PRESSURE WILL MOVE OVER THE REGION THROUGH THE FIRST PART OF
THIS WEEK. THIS SYSTEM WILL BRING SUNNY AND MILD DAYS AND CHILLY
NIGHTS. FROST WILL BE POSSIBLE TONIGHT NORTH OF I-96.
TEMPERATURES WILL SLOWLY WARM INTO THE LATTER PART OF THE WEEK. THE
NEXT CHANCE OF RAIN SHOULD HOLD OFF UNTIL SATURDAY.
&&
.UPDATE...
ISSUED AT 1040 AM EDT SUN SEP 22 2013
IT IS CLEAR TO ME (PUN INTENDED) THE SKIES WILL IN FACT NOT BE
CLEAR ANY TIME SOON. THE AREA OF STRATOCUMULUS CLOUDS CONTINUES TO
EXPAND SOUTHWARD OVER THE SOUTHERN AND SOUTHWEST CWA. GIVEN THE
LACK OF ANY TREND FOR THE CLOUDS TO BREAK UP SOON I HAVE UPDATED
THE ZONES TO KEEP THE CLOUDS AROUND INTO EARLY THIS AFTERNOON. THE
LATEST MODEL RUNS... LIKE THE RAP AND THE OUTGOING LONGWAVE
RADIATION FEATURE ON THE HRRR 12Z RUN SUGGEST THE CLEARING WILL BE
MORE IN THE 2 TO TO 5 PM TIME FRAME. SO THAT IS WHERE I NOW HAVE
IT IN THE GRIDS. IF THE CLOUDS DO HANG AROUND INTO MID AFTERNOON
THE HIGHS WILL ONLY BE THE 50S... I LOWERED THE AFTERNOON TEMPS
ABOUT 2 DEGREES BUT THAT MAY NOT BE ENOUGH. WE SHALL SEE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
FIRST CHALLENGE IN THE SHORT TERM WAS DETERMINING WHEN THE CLOUDS
OVER THE REGION WILL FINALLY CLEAR. THEN FROST/FREEZE POTENTIAL
BECOMES A CONCERN TONIGHT.
THE UPPER LOW OVER WESTERN QUEBEC CONTINUES TO BRING CHILLY NW FLOW
OVER THE REGION. THE COMBINATION OF MOISTURE WRAPPING AROUND THIS
LOW AND LAKE DELTA T/S AROUND 18...HAS HELD IN A SC DECK INTO EARLY
THIS MORNING. HOWEVER AS THE LOW SHIFTS TO EASTERN QUEBEC LATER
TODAY...SURFACE AND UPPER RIDGING MOVES INTO THE WESTERN GREAT LAKES
ALONG WITH WARM ADVECTION ALOFT BY AFTERNOON. SO BELIEVE THE CLOUDS
WILL ERODE FAIRLY QUICKLY ONCE THE SUN IS UP...AND MOSTLY SUNNY
SKIES CAN BE EXPECTED CWA-WIDE BY LATE MORNING.
THE SURFACE RIDGE WILL SIT OVER THE CWA TONIGHT BRINGING CLEAR SKIES
AND LIGHT WINDS. THIS WILL BE IDEAL RADIATION CONDITIONS AND
FROST/FREEZE HEADLINES WILL BE POSTED ACROSS THE NORTHERN CWA.
PATCHY FROST WILL BE POSSIBLE OVER THE SOUTHERN HALF TOO...BUT IT
SHOULD BE ISOLATED ENOUGH TO NOT WARRANT HEADLINES.
LITTLE WEATHER TO SPEAK OF FOR MONDAY AND TUESDAY. THE UPPER FLOW
REMAINS FAIRLY AMPLIFIED WHICH WILL KEEP THE PATTEN BLOCKED AND KEEP
THE SURFACE AND UPPER RIDGE NEARBY. TEMPS SHOULD MODERATE EACH
DAY...TO 70 TO 75 BY TUESDAY. FROST SHOULD LESS OF A THREAT MONDAY
NIGHT WITH SE LOW LEVEL FLOW DEVELOPING.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
WARM AND DRY IS THE MAIN MESSAGE IN THE LONG TERM PERIOD AS A HIGH
AMPLITUDE UPPER LEVEL RIDGE DOMINATES OUR WEATHER. THIS FEATURE WILL
LEAD TO TEMPERATURES ABOUT 10 DEGREES ABOVE NORMAL WITH HIGHS IN THE
MID TO UPPER 70S AND LOWS IN THE 50S.
HAVE REMOVED THE LOW CHANCE OF SHOWERS FOR FRIDAY NIGHT BUT LEFT
THEM IN FOR SATURDAY DUE TO THE WET LOOK OF THE GFS. THE EURO ON THE
OTHER HAND IS A DAY SLOWER WITH THE FRONT AND SUGGESTS THE BETTER
RAIN CHANCES WOULD HOLD OFF UNTIL SATURDAY NIGHT OR SUNDAY. THIS MAY
BE MORE REASONABLE GIVEN THE HIGHLY AMPLIFIED UPPER RIDGE SO PERHAPS
IN FUTURE FORECASTS WE CAN GO DRY ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 732 AM EDT SUN SEP 22 2013
HIGH CONFIDENCE WIDESPREAD VFR CONDITIONS TODAY AND TONIGHT. NORTH
WINDS UNDER 10 KNOTS TODAY BECOMING LIGHT EAST TONIGHT.
&&
.MARINE...
ISSUED AT 323 AM EDT SUN SEP 22 2013
EXTENDED THE SCA OVER THE LDM REGION THROUGH THE MORNING AS A NNE
FLOW WILL KEEP THE WAVES HIGHER IN THIS REGION. SOUTHERN AREAS WILL
BE MORE SHELTER FROM THE NNE WIND AND WILL SEE LOWER WAVES. WITH
HIGH PRESSURE MOVING IN...THE REST OF THE SHORT TERM LOOKS QUIET ON
THE LAKE.
&&
.HYDROLOGY...
ISSUED AT 323 AM EDT SUN SEP 22 2013
NO RAIN IS EXPECTED UNTIL NEXT WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ039-040.
FROST ADVISORY FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ037-038-
044>046-051.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR LMZ849.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
725 AM EDT SUN SEP 22 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A CONFLUENT NW
FLOW ALF OVER THE UPR GREAT LKS BTWN UPR RDG IN THE PLAINS AND DEEP
UPR TROF EXTENDING FM HUDSON BAY/WRN QUEBEC S THRU THE APPALACHIANS.
SINCE THE PATTERN IS SLOWLY PROGRESSIVE...00Z RAOBS SHOWED 12Z-24Z
H3/H5 HGT RISES UP TO 100M FM NW ONTARIO INTO THE WRN GREAT LKS. THE
LARGER SCALE SUBSIDENCE ASSOCIATED WITH THESE DYANMICS ARE
SUPPORTING A SFC HI PRES FM NW ONTARIO THRU WRN LK SUP AND INTO WI.
BUT SINCE THE 00Z YPL RAOB SHOWS MSTR TRAPPED WITHIN LLVL THERMAL
TROF DIPPING INTO THE GREAT LKS AND UNDER SUBSIDENCE INVRN NEAR
H85...THERE ARE AREAS OF LK EFFECT SC OVER PORTIONS OF UPR MI IN
SLOWLY VEERING LLVL NLY FLOW E OF THE RDG AXIS. H85 TEMPS AS LO AS
-3C OVER THE E HALF OF LK SUP ARE SUPPORTING ISOLD LK EFFECT -SHRA
AS WELL IN THAT AREA. THE WRN EDGE OF THE SC IS RIGHT UP TO RDG AXIS
NEAR IWD AT 06Z. TO THE W OF THIS LINE...MUCH DRIER AIR SHOWN ON THE
00Z INL RAOB IS BRING CLR SKIES. H85 TEMPS WARM FAIRLY STEADILY TO
THE W...WITH THE 00Z TEMP UP TO 13C AT ABERDEEM SDAKOTA AND BISMARCK
IN THE LARGE SCALE SLY FLOW W OF THE RDG AXIS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LK EFFECT CLD/-SHRA TRENDS.
FOCUS FOR TNGT SHIFTS TO THE PROSPECT OF MORE FROST WITH THE HI PRES
MOVING GRADUALLY TO THE E IN THE SLOWLY PROGRESSIVE UPR PATTERN.
TODAY...SFC HI PRES RDG AXIS IS PROGGED TO DRIFT SLOWLY E THRU THE
DAY...REACHING THE ERN CWA BY 00Z MON. WITH LARGER SCALE SUBSIDENCE
WARMING THE H85 TEMPS/STRENGTHENING INVRN...EXPECT ANY LINGERING LK
EFFECT -SHRA TO DIMINISH EARLY TODAY. AS OBSVD EARLY THIS MRNG...
PASSAGE OF RDG AXIS/MORE ACYC LLVL FLOW AS WELL AS DAYTIME HEATING/
MIXING SHOULD RESULT IN AN EROSION OF LINGERING LK CLDS AS WELL. THE
SC WL BE MOST RESILIENT OVER THE NCENTRAL THIS MRNG WITH UPSLOPE NNE
WIND COMPONENT...WITH LINGERING LLVL MSTR/THERMAL TROFFING TO THE E
OF THE ENCROACHING RDG AXIS ALLOWING FOR AT LEAST MORE DAYTIME CU/SC
OVER THE ERN CWA INTO THE AFTN. SUBSIDENCE WARMING/RETURN SLY FLOW
TO THE W OF THE HI PRES IS PROGGED TO LIFT H85 TEMPS NEAR 10C AT IWD
BY 00Z MON. WITH A GOOD DEAL OF SUNSHINE IN THIS AREA...EXPECT HI
TEMPS TO REACH 60 TO 65 OVER THE W AWAY FM LK MODERATION.
TNGT...THE SFC RDG AXIS IS FCST TO DRIFT ONLY SLOWLY E OF THE SAULT
TNGT. WITH CLEAR SKIES AND PWAT 0.33 TO 0.50 INCH /AS LO AS 60 PCT
OF NORMAL/...EXPECT A FAVORABLE SETUP FOR A SHARP DIURNAL TEMP FALL
OVER THE E HALF OF THE CWA...WHERE THE PRES GRADIENT IS FCST TO BE
RATHER FLAT AND H925 WINDS NO MORE THAN ABOUT 10 KTS THRU 12Z MON.
WL TEND TOWARD THE LO END OF GUIDANCE FOR MIN TEMPS OVER THE
INTERIOR E HALF...WHERE FROST IS LIKELY. OVER THE W...A STRONGER
RETURN FLOW WITH S H925 WINDS UP TO 20-25 KTS WL MITIGATE THE
DIURNAL DROP. PLAN TO ISSUE A FROST ADVY FOR THE E AND CENTRAL
PORTION OF THE CWA. BUT WL WAIT UNTIL THE CURRENT ADVY EXPIRES AT
12Z TO ISSUE THE HEADLINE/STATEMENT TO AVOID CONFUSION.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
A DRY AND WARMER THAN NORMAL START TO FALL IS EXPECTED THIS WEEK.
THIS IS DUE TO THE UPPER TROUGH THAT MOVED THROUGH THE AREA THIS
MORNING SLOWLY MOVING THROUGH THE CANADIAN MARITIMES THIS WEEK.
THIS WILL SETUP A BLOCK AND KEEP THE UPSTREAM CONDITIONS LOCKED IN
PLACE FOR MUCH OF THE UPCOMING WORK WEEK. FOR THE UPPER GREAT LAKES
REGION...THIS MEANS AN UPPER RIDGE WILL BE OVER THE AREA WITH A
SURFACE HIGH JUST TO THE EAST OF THE AREA. THUS...EXPECT SOUTHERLY
FLOW TO PULL WARMER AIR NORTH AND LEAD TO A WEEK OF ABOVE NORMAL
TEMPERATURES AND REALLY NICE LATE SEPTEMBER WEATHER.
EXPECT MOSTLY CLEAR THROUGH MUCH OF THE WEEK...ALTHOUGH THERE
ARE SOME HINTS OF DIURNAL CU DEVELOPING OVER THE EAST WITH SOME
MOISTENING OFF LAKE MICHIGAN WHEN THE SOUTHERLY FLOW DEVELOPS. DID
TRY TO SHOW THAT POTENTIAL ON MONDAY/TUESDAY FOR A PERIOD DURING
PEAK AFTERNOON HEATING. HIGHS MOST DAYS THIS WEEK WILL BE IN THE
UPPER 60S AND LOWER 70S THIS WEEK WITH LOWS IN THE 40S/50S.
MAIN CONCERNS FOR WEATHER WILL BE A SHORTWAVE EXITING THE CENTRAL
PLAINS ON TUESDAY...BUT IS SHOULD FALL APART BEFORE REACHING THE
AREA AND KEEP THINGS DRY. 00Z GFS DOES TRY TO PUT SOME PRECIP
INTO IRONWOOD TUESDAY AFTERNOON/EVENING...BUT WITH 00Z NAM/GEM/ECMWF
AND OUR WRF-ARW KEEPING IT DRY...WILL FOLLOW THAT IDEA. ONLY AFFECT
IT SHOULD HAVE ON THE U.P. IS SOME MID-HIGH CLOUDS...MAINLY OVER THE
WESTERN THIRD OF THE CWA.
ANOTHER UPPER TROUGH WILL EXIT THE ROCKIES ON FRIDAY AND THIS ONE
ALSO LOOKS TO STRUGGLE WITH THE BLOCKING UPPER RIDGE IN THE GREAT
LAKES REGION. MODELS HAVE DIFFERING SOLUTIONS ON HOW THIS SYSTEM
WILL EVOLVE HEADING INTO THE WEEKEND...SO WILL FOLLOW A GENERAL
CONSENSUS OF PRECIPITATION CHANCE INCREASING FRIDAY NIGHT INTO
SATURDAY AS THE UPPER TROUGH SWEEPS EAST-NORTHEAST THROUGH THE
AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 723 AM EDT SUN SEP 22 2013
EXPECT LO CLDS...WITH MVFR CIGS AT SAW AND POSSIBLY CMX THIS
MRNG...TO CLR BY EARLY AFTN WITH SLOW PASSAGE OF SFC HI PRES RDG
MOVING INTO THE UPR GREAT LKS. THEN VFR WX WL PREVAIL AS DRY AIRMASS
NOTED ON THE 00Z INL RAOB SHIFTS E OVER UPR MI WITH THE HI PRES RDG.
A SHARPENING PRES GRADIENT ON THE WRN FLANK OF THIS SFC HI WL DVLP
OVER WRN UPR MI LATER TNGT. AS THE S WIND STRENGTHENS ABV RADIATION
INVRN/DECOUPLED NEAR SFC LYR...LLWS WL IMPACT IWD AFT 23/06Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE CURRENTLY OVER LAKE SUPERIOR WILL SLIDE EAST OVER
THE LOWER GREAT LAKES AND EASTERN ONTARIO TONIGHT AND THEN REMAINING
STATIONARY THROUGH MUCH OF THE UPCOMING WORK WEEK. WHILE THIS
OCCURS...SOUTHERLY FLOW WILL INCREASE SLIGHTLY STARTING
TONIGHT...BUT EXPECT THE WINDS TO BE BELOW 20KTS FOR MOST OF
THE PERIOD. THE PERIODS OF THE STRONGEST WINDS LOOK TO BE MONDAY
NIGHT (AS AN AREA OF LOW PRESSURE MOVES OUT OF THE PLAINS AND
DISSIPATES) AND ON THURSDAY NIGHT INTO FRIDAY NIGHT (AS ANOTHER LOW
MOVES OUT OF THE CENTRAL PLAINS AND INTO WESTERN ONTARIO). DURING
THOSE TIME PERIODS...THERE COULD BE SLIGHTLY HIGHER GUSTS TO
25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY FROM 2 AM EDT /1 AM CDT/ TO 8 AM EDT /7 AM CDT/
MONDAY FOR MIZ004>007-010>014-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 AM CDT SUN SEP 22 2013
.UPDATE...
ISSUED AT 951 AM CDT SUN SEP 22 2013
CURRENTLY HAVE A LITTLE BIT OF THIN CIRRUS OR CONTRAILS ACROSS THE
FAR NORTHERN FA OTHERWISE SKIES ARE STILL CLEAR. MAIN WEATHER
STORY TODAY WILL BE THE GUSTY SOUTHEAST WINDS. CURRENT FORECAST
HAS THINGS WELL IN HAND AND SEE NO REASON FOR ANY UPDATE AT THIS
POINT.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MAIN CHALLENGES WILL BE TEMPERATURES TODAY AND PRECIP CHANCES
TONIGHT INTO MONDAY. 00Z MODELS ARE IN DECENT AGREEMENT THROUGH
THIS PERIOD AND WILL USE A BLEND FOR DETAILS. 500MB LOW WILL
PROPAGATE FROM THE SOUTHWEST CONUS INTO THE CENTRAL PLAINS. THIS
WILL DEVELOP SOUTHWEST FLOW ALOFT BY TONIGHT...CONTINUING INTO
MONDAY. ALTHOUGH LOW LEVEL FLOW WILL SIGNIFICANTLY INCREASE...IT
WILL BE FROM MORE OF A SOUTHEAST DIRECTION...PROMOTING THE VERY
DRY LOW LEVEL AIRMASS. THIS WILL BE A HINDRANCE ON PRECIP
POTENTIAL. FOR TONIGHT...MODELS INDICATE A STRONG 850MB JET 40-50
KNOTS...WITH WEAK INSTABILITY QUICKLY ADVECTING NORTHWARD ALONG
THE WESTERN EDGE OF THIS FEATURE. COULD BE AN ISOLATED STORM
(ACROSS THE FAR WESTERN FA)...BUT INSTABILITY SEEMS TO BE IN AN
UNFAVORABLE AREA. FOR MONDAY...HIGHER MOISTURE AND LOW LEVEL
CONVERGENCE REMAINS WEST OF THE REGION...WITH AREAS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA (POSSIBLY PORTIONS OF THE DEVILS
LAKE BASIN) MOST LIKELY TO EXPERIENCE SHOWERS.
MAX TEMPS TODAY SHOULD RANGE FROM THE UPPER 60S INTO THE UPPER
70S. THE 06Z RAP IS SHOWING A STRONG WARM FRONT MOVING INTO THE
SW FA...WITH TEMPS INTO THE UPPER 80S. MOST MODELS SHOW THIS
FEATURE...BUT NOT QUITE AS FAR NORTH BY 00Z MONDAY. WILL HAVE TO
MONITOR...FOR NOW STUCK WITH LOW TO MID 80S FOR THIS AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MONDAY NIGHT-TUESDAY NIGHT...THE LOW LEVEL CONVERGENCE SHIFTS
EASTWARD AND THROUGH THE FA. THE LOW LEVEL AIRMASS SHOULD REMAIN
DRY AS THE MAJORITY OF MODELS SHOW THE MAIN UPPER LOW WILL BE WELL
SOUTH OF THE REGION. ANTICIPATE A BAND OF SHOWERS THAT WILL WEAKEN
AS IT MOVES EAST AND FINALLY DIES BY TUESDAY AFTERNOON.
TEMPERATURES WILL DEPEND ON CLOUD COVER...BUT GENERALLY SLIGHTLY
ABOVE NORMAL VALUES.
WEDNESDAY-SATURDAY...500MB SOUTHWEST FLOW ALOFT WILL CONTINUE TO
ALLOW ABOVE NORMAL TEMPERATURES INTO THE NORTHERN PLAINS THRU THE
END OF THE WEEK. TIMING AND PLACEMENT OF SHORT WAVE ENERGY TO
TRACK FROM THE ROCKIES ACROSS THE DAKOTAS STILL UNCERTAIN...
THOUGH BEST CHANCES FOR MEASURABLE RAINFALL WILL BE WITH FROPA ON
FRIDAY. POPS IN THE FORECAST FOR WED AND THURS ARE LESS CERTAIN
ESPECIALLY FROM RED RIVER VALLEY AND EASTWARD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 645 AM CDT SUN SEP 22 2013
GUSTY SOUTH-SOUTHEAST WINDS TODAY AND TONIGHT. CLEAR SKY WITH
CIRRUS MOVING INTO THE REGION THIS AFTERNOON AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GODON
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...TG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
645 AM CDT SUN SEP 22 2013
.UPDATE...
ISSUED AT 645 AM CDT SUN SEP 22 2013
THE FORECAST IS ON TRACK AND NO UPDATE IS NEEDED. HOWEVER...FORGOT
TO MENTION THE WIND SPEED CHALLENGE IN THE 338 AM SHORT TERM
SECTION. AS OF 645AM...WIND SPEEDS ARE INCREASING AND SHOULD
CONTINUE TO INCREASE THROUGH THE MORNING HOURS. FROM MODEL
SOUNDINGS...EXPECT UNIDIRECTIONAL MIXING LAYER TO AROUND
850MB...WITH ABOUT 30 KNOTS AVAILABLE TO MIX THROUGH THIS LAYER.
THIS SHOULD LEAD TO SPEEDS AOA 20 MPH MOST AREAS...WITH GUSTS TO
30 MPH ALONG AND WEST OF THE VALLEY. DO NOT ANTICIPATE ADVISORY
CONDITIONS...BUT WILL MONITOR.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MAIN CHALLENGES WILL BE TEMPERATURES TODAY AND PRECIP CHANCES
TONIGHT INTO MONDAY. 00Z MODELS ARE IN DECENT AGREEMENT THROUGH
THIS PERIOD AND WILL USE A BLEND FOR DETAILS. 500MB LOW WILL
PROPAGATE FROM THE SOUTHWEST CONUS INTO THE CENTRAL PLAINS. THIS
WILL DEVELOP SOUTHWEST FLOW ALOFT BY TONIGHT...CONTINUING INTO
MONDAY. ALTHOUGH LOW LEVEL FLOW WILL SIGNIFICANTLY INCREASE...IT
WILL BE FROM MORE OF A SOUTHEAST DIRECTION...PROMOTING THE VERY
DRY LOW LEVEL AIRMASS. THIS WILL BE A HINDRANCE ON PRECIP
POTENTIAL. FOR TONIGHT...MODELS INDICATE A STRONG 850MB JET 40-50
KNOTS...WITH WEAK INSTABILITY QUICKLY ADVECTING NORTHWARD ALONG
THE WESTERN EDGE OF THIS FEATURE. COULD BE AN ISOLATED STORM
(ACROSS THE FAR WESTERN FA)...BUT INSTABILITY SEEMS TO BE IN AN
UNFAVORABLE AREA. FOR MONDAY...HIGHER MOISTURE AND LOW LEVEL
CONVERGENCE REMAINS WEST OF THE REGION...WITH AREAS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA (POSSIBLY PORTIONS OF THE DEVILS
LAKE BASIN) MOST LIKELY TO EXPERIENCE SHOWERS.
MAX TEMPS TODAY SHOULD RANGE FROM THE UPPER 60S INTO THE UPPER
70S. THE 06Z RAP IS SHOWING A STRONG WARM FRONT MOVING INTO THE
SW FA...WITH TEMPS INTO THE UPPER 80S. MOST MODELS SHOW THIS
FEATURE...BUT NOT QUITE AS FAR NORTH BY 00Z MONDAY. WILL HAVE TO
MONITOR...FOR NOW STUCK WITH LOW TO MID 80S FOR THIS AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MONDAY NIGHT-TUESDAY NIGHT...THE LOW LEVEL CONVERGENCE SHIFTS
EASTWARD AND THROUGH THE FA. THE LOW LEVEL AIRMASS SHOULD REMAIN
DRY AS THE MAJORITY OF MODELS SHOW THE MAIN UPPER LOW WILL BE WELL
SOUTH OF THE REGION. ANTICIPATE A BAND OF SHOWERS THAT WILL WEAKEN
AS IT MOVES EAST AND FINALLY DIES BY TUESDAY AFTERNOON.
TEMPERATURES WILL DEPEND ON CLOUD COVER...BUT GENERALLY SLIGHTLY
ABOVE NORMAL VALUES.
WEDNESDAY-SATURDAY...500MB SOUTHWEST FLOW ALOFT WILL CONTINUE TO
ALLOW ABOVE NORMAL TEMPERATURES INTO THE NORTHERN PLAINS THRU THE
END OF THE WEEK. TIMING AND PLACEMENT OF SHORT WAVE ENERGY TO
TRACK FROM THE ROCKIES ACROSS THE DAKOTAS STILL UNCERTAIN...
THOUGH BEST CHANCES FOR MEASURABLE RAINFALL WILL BE WITH FROPA ON
FRIDAY. POPS IN THE FORECAST FOR WED AND THURS ARE LESS CERTAIN
ESPECIALLY FROM RED RIVER VALLEY AND EASTWARD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 645 AM CDT SUN SEP 22 2013
GUSTY SOUTH-SOUTHEAST WINDS TODAY AND TONIGHT. CLEAR SKY WITH
CIRRUS MOVING INTO THE REGION THIS AFTERNOON AND OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
635 AM CDT SUN SEP 22 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...CEILINGS HAVE LIFTED TO AROUND 10KFT ACROSS THE
LOWER VALLEY. EXPECT THIS LAYER TO BREAK AND CLEAR OUT BY
THE EARLY MORNING HOURS WITH NORTHERLY WINDS INCREASING WITH
GUSTS UP 25 KNOTS POSSIBLE. THE LOW PRESSURE OVER THE GULF OF
MEXICO WILL CONTINUE TO SHIFT NORTHEAST WHICH WILL ALLOW FOR
WINDS TO DECOUPLE INTO THE EVENING. VFR CONDITIONS WILL PREVAIL
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 345 AM CDT SUN SEP 22 2013/
SHORT TERM /NOW THROUGH MONDAY/...UPPER LEVEL TROUGH MOVING
ACROSS NORTHERN CA INTO NEVADA WILL DEEPEN AND MIGRATE
EAST/SOUTHEAST INTO THE FOUR CORNERS REGION WHILE RIDGE BUILDS
OVER NORTH CENTRAL TEXAS. AN ELONGATED POSITIVE TILTED TROUGH OVER
THE TEXAS REGION WILL GRADUALLY SHIFT EASTWARD ADVECTING DRIER AIR
ACROSS SOUTH TEXAS FROM THE NORTH. SURFACE LOW OVER THE GULF
WATERS WILL STRENGTHEN THE GRADIENT ALONG THE RIO GRANDE VALLEY
AND KEEP A NORTH TO NORTHEAST FLOW ACROSS MUCH OF THE CWA TODAY.
WINDS WILL INCREASE BETWEEN 20 TO 25 MPH ESPECIALLY ALONG THE
COAST. AS DRIER AIR MOVES INTO S TEXAS...CLEAR SKIES WILL PREVAIL
ACROSS THE CWA WHILE AT THE COAST MOISTURE RAP AROUND THIS LOW
WILL INCREASE THE CLOUD COVER BETWEEN A FEW TO SCATTERED CLOUD
LAYER ALONG THE COAST. THE MOISTURE CONTENT WILL NOT BE VERY
SHALLOW WHICH WILL LIMIT CONVECTION TO DEVELOP. HIGH TEMPERATURES
TODAY WILL TREND 2 TO 3 DEG WARMER COMPARED TO YESTERDAYS
TEMPERATURES.
AS THIS LOW CONTINUES TO MOVE FURTHER FROM THE COAST OF TEXAS THIS
AFTERNOON..SFC GRADIENT WILL GRADUALLY RELAX AND REDUCE THE NORTH TO
NORTHEAST WINDS ACROSS THE AREA AND THE CHANCES OF RAIN LOWERS. A FEW
SHOWERS CAN NOT BE RULED OUT BUT WILL REMAIN OVER THE OFFSHORE WATERS
TODAY. TONIGHT...NORTHERLY FLOW WILL DIMINISH ACROSS THE CWA AN REMAIN
LIGHT AND VARIABLE DUE TO THE WEAKENING SURFACE GRADIENT. LOW TEMPS
WILL REMAIN WELL BELOW NORMAL...WITH THE WESTERN PORTION REACHING
THE MID TO UPPER 60S WHILE ALONG THE COAST REMAINING IN THE LOW 70S.
MONDAY...SURFACE LOW BEGINS TO MOVE PARALLEL TO THE TEXAS COAST INTO
THE NORTHWEST GULF WHILE DRIER AIR INDICATED BY THE NAM AND THE GFS
AT 1000 TO 500 MB RH LAYER MOVES INTO THE CWA FROM THE NORTHWEST. AS
THE DRY AIR INFILTRATES INTO THE CWA...THE CHANCE OR RAIN LOWERS
EVEN MORE TO LESS THAN 10 PERCENT ACROSS THE CWA. HIGH TEMPERATURES
WILL CONTINUE TO WARM INTO NEAR NORMAL TEMPERATURES FOR SEPTEMBER
WITH HIGHS NEAR THE MID 90S ALONG THE INTERNATIONAL BORDER. NORTH
WINDS WILL DECOUPLE QUICKLY AFTER SUNSET.
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...500MB TROUGH ACROSS
THE NORTH CENTRAL UNITED STATES MONDAY WILL SHIFT EASTWARD TUESDAY
AS A 500MB RIDGE BUILDS ACROSS THE SOUTHERN PLAINS. NORTHWEST FLOW
ALOFT WILL CONTINUE TO PROVIDE SUBSIDENCE ACROSS SOUTH TEXAS
TUESDAY INTO WEDNESDAY. LOW TO MID LEVEL MOISTURE IS EXPECTED TO
RETURN ACROSS THE RIO GRANDE VALLEY THURSDAY INTO FRIDAY AS A
500MB TROUGH DEVELOPS ACROSS THE WESTERN UNITED STATES AND THE
UPPER LEVEL RIDGE ACROSS TX SHIFTS EASTWARD. SURFACE LOW PRESSURE
IS PROGGED TO DEVELOP ACROSS THE CENTRAL PLAINS FRIDAY AHEAD OF
THE UPPER LEVEL TROUGH ACROSS THE WESTERN U.S. BRINGING A WEAK
COLD FRONT TOWARDS CENTRAL TX SATURDAY. THIS WILL PROVIDE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE WEEKEND AS MOISTURE
POOLS ALONG AND AHEAD OF THE FRONT AS THE FRONT MOVES INTO SOUTH
TX SATURDAY INTO SUNDAY.
MARINE...
NOW THROUGH MONDAY...MARINE CONDITIONS REMAIN DETERIORATED FOR
MUCH OF THE SHORT TERM FORECAST. LATEST OBSERVATION SHOWS SEAS
BUILDING NEAR 9 FEET OVER THE GULF WATERS DUE TO THE SURFACE LOW
PRESSURE OVER THE GULF OF MX. THIS LOW WILL STRENGTHEN THE
GRADIENT ALONG THE GULF WATERS AND INCREASE WINDS BETWEEN 20 TO 25
KNOTS AND GUSTS UP TO 30 KNOTS AT TIMES. SEAS WILL BUILD TODAY
INCREASING CLOSE TO 10 FEET THROUGH THE DAY. THE SEAS BEGIN TO
LOWER OVER THE NEAR SHORE WATERS AS THE CENTER OF THE LOW BEGINS
TO MOVE FURTHER EAST EARLY TONIGHT. HOWEVER...A NORTHEAST FETCH
WILL KEEP SEAS HIGHER THROUGH THE EVENING OVER THE GULF SO THE SCA
HAS BEEN EXTENDED FOR THE WHOLE MARINE AREA WITH THE EXCEPTION OF
THE LAGUNA MADRE. ON THE BAY...CONDITIONS WILL BE MARGINAL TO
SMALL CRAFT ADVISORY BUT IT WILL LIKELY BE FOR AN HOUR AND QUICKLY
LOWER THE WINDS. THE NORTHEAST WINDS OVER THE OFFSHORE WATERS WILL
CONTINUE TO KEEP SEAS HIGH AS THE LOW PRESSURE MOVES NORTHWARD SO
EXTENDED THE SCA FOR THE OFFSHORE THROUGH MIDNIGHT. THE SEAS WILL
GRADUALLY LOWER TO SCEC BY EARLY MORNING MONDAY AND IMPROVE UNTIL
THE END OF THE DAY MONDAY WITH SEAS BETWEEN 2 TO 4 FEET. AN
ISOLATED SHOWER WILL BE POSSIBLE BUT WILL NOT LAST LONG AND
PRODUCE BRIEF DOWNPOURS.
MONDAY NIGHT THROUGH THURSDAY...LIGHT TO MODERATE NORTH TO
NORTHEAST WINDS ACROSS THE COASTAL WATERS MON NIGHT WILL BACK TO
THE WEST ON TUESDAY AS THE LOW PRESSURE ACROSS THE WESTERN GULF OF
MEXICO MOVES NORTHWARD. LIGHT WEST TO NORTHWEST WINDS SHOULD
PREVAIL ACROSS THE WESTERN GULF WEDNESDAY BEFORE FINALLY SHIFTING
TO THE SOUTHEAST ON THURSDAY AS LOW PRESSURE MOVES INTO THE
NORTHERN PLAINS AND THE LOW PRESSURE ACROSS THE NORTHERN GULF OF
MEXICO WEAKENS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT MONDAY FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/61
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1226 PM MDT SUN SEP 22 2013
.UPDATE...
&&
.SHORT TERM...WEAK SHOWER BAND DEVELOPING OVER THE FRONT RANGE AT
THIS TIME. LITTLE CAPE TO WORK WITH BUT MOISTENING AND COOLING
ALOFT ARE SETTING IN. LOW LEVEL WIND SHIFT AND ASSOCIATED DRYING
HAS PUSHED EAST OF AKRON...STILL COULD HAVE SOME STRONGER STORMS
DEVELOP OVER SEDGWICK AND PHILLIPS COUNTIES THIS AFTERNOON...THERE
MAY BE A LITTLE CONVERGENCE CENTER NEAR HOLYOKE AHEAD OF THE
BETTER MOISTURE COMING UP FROM THE SOUTH. A SMALL RISK OF SEVERE
HAIL OR WIND WITH ANYTHING THAT WOULD FORM OUT THERE...IT WOULD
MOVE PRETTY QUICKLY EASTWARD. MORE SIGNIFICANT WEATHER IS THE
DEVELOPING THUNDERSTORM BAND CURRENTLY NEAR RIFLE...THIS SHOULD
DEVELOP AN ORGANIZED WIND FIELD AND IT IS ALREADY PRODUCING 40-50
MPH WIND GUSTS. THIS WILL MOVE OVER THE MOUNTAINS THIS AFTERNOON
REACHING DENVER IN THE 5 TO 7 PM TIME FRAME. SOME POTENTIAL FOR
SEVERE WIND GUSTS WITH THIS...WILL BE WATCHING THAT. NOT A LOT OF
CAPE BUT ORGANIZED LIFT COULD PRODUCE STRONG UPDRAFTS ON THIS
BOUNDARY...SMALLER THREAT OF HAIL. AS FAR AS THE RAIN
THREAT...GOOD UPDRAFTS COULD PROVIDE A BAND OF HEAVY RAIN...BUT
PROBABLY LASTING LESS THAN AN HOUR...MORE LIKELY A HALF INCH IN 30
MINUTES...SO THE FLASH FLOOD THREAT LOOKS LOW. MORE BANDS OF
THUNDERSTORMS BEHIND THAT THIS EVENING...TRANSITIONING INTO MORE
OF A STEADY LIGHTER RAIN ON THE PLAINS OVERNIGHT AS THE SYSTEM
DEVELOPS. AT THIS TIME NOT EXPECTING ENOUGH RAIN TO HAVE MUCH
IMPACT ON RIVERS...THOUGH SOME RISES ON SMALL CREEKS CAN BE
EXPECTED AS THE RUNOFF WILL BE PRETTY EFFICIENT.
&&
.AVIATION...EXPECT SOUTH WINDS TO DOMINATE THIS AFTERNOON. THERE
MAY BE A BIT OF AN EASTERLY COMPONENT IN THE EARLY AFTERNOON...BUT
MIXING AND OUTFLOW FROM MOUNTAIN CONVECTION SHOULD PRODUCE SW
WINDS LATER.
AN ORGANIZED N-S BAND OF THUNDERSTORMS WILL MOVE ACROSS THE
MOUNTAINS THIS AFTERNOON AND PASS THROUGH DENVER AROUND 00Z WITH
A PERIOD OF WEST WINDS. STRONG WEST WIND GUSTS IN THE 30-50 KNOT
RANGE MAY ACCOMPANY THIS AND COULD IMPACT LANDINGS AT KDEN...BUT
FOR AN HOUR OR LESS. THIS LINE WILL CONTINUE TO MOVE EAST AND BE
FOLLOWED BY WEAKER SHOWER BANDS OVERNIGHT. WINDS WILL
PREDOMINANTLY BE FROM THE WEST AT LESS THAN 20 KNOTS OVERNIGHT
THOUGH THERE COULD BE A FEW GUSTY PERIODS WITH SHOWERS. INSTRUMENT
APPROACHES TO KDEN MAY BE NEEDED DUE TO CEILINGS. THE SHOWERS WILL
MOVE EAST BY MONDAY MORNING...WINDS WILL BECOME NORTHWEST AND
INCREASE DURING THE DAY WITH GUSTS IN THE 20-30 KNOT RANGE
EXPECTED AT KDEN DURING THE AFTERNOON...A BIT LESS AT KAPA/KBJC.
&&
.PREV DISCUSSION... /ISSUED 340 AM MDT SUN SEP 22 2013/
SHORT TERM...A RATHER POTENT SHORTWAVE TROUGH CURRENTLY OVER THE
WESTERN GREAT BASIN ALONG WITH A MID-LEVEL CIRCULATION CENTER
EVIDENT ON H20 VAPOR SAT IMAGERY SOUTHEAST OF RENO NV ARE PROGGED
TO MOVE EAST-SOUTHEAST FAIRLY QUICKLY THIS MORNING. DETERMINISTIC
MODELS AND ENSEMBLE MEMBERS ARE IN REASONABLY GOOD AGREEMENT AS
THEY SHOW THIS SYSTEM INTENSIFYING/DEEPENING SOME AS IT
APPROACHES WESTERN COLORADO. MODEL CONSENSUS HAS THE 500MB LOW
NEARING THE 4-CORNERS AREA BY 00Z/TODAY. FROM THERE MODELS SHOW
THE LOW TRACKING NORTHEASTWARD ACROSS CENTRAL AND NORTHEAST
COLORADO OVERNIGHT. A VIGOROUS PACIFIC COLD FRONT TRAILING
SOUTHWESTWARD ACROSS NEVADA FROM A SFC LOW IN SOUTHEAST IDAHO IS
ALSO FCST TO TRACK EAST WITH THE UPPER TROUGH. MODELS SHOW THIS
SHARP BAROCLINIC ZONE MOVING INTO WESTERN COLORADO NOT TOO LONG
AFTER 18Z/TODAY...AND THEN MOVING OUT ONTO THE NERN PLAINS OF
COLORADO EARLY THIS EVENING. MODELS/ENSEMBLE MEMBERS SHOW A SFC
LOW FORMING ON THE FRONT SOMEWHERE BETWEEN DENVER AND GREELEY.
STEEP MID-LEVEL LAPSE RATES AND RATHER ROBUST DEEP LAYER QG
ASCENT WITH THE UPPER LOW PASS OVER THE NORTH CENTRAL CO MTNS
THIS AFTERNOON RESULTING IN SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED TO SCATTERED T-STORMS. WETBULB ZERO EXPECTED TO REMAIN
ABOVE MTN TOP LEVEL DURING THE DAYLIGHT HOURS...BUT STG
EVAPORATIVE COOLING WITH CONVECTION COULD GENERATE A BRIEF BUT
INTENSE SNOW SHOWER ABOVE TIMBERLINE. IT NOW APPEARS AS THOUGH THE
PLAINS WILL SEE ITS BEST SHOT AT PRECIP THIS EVENING...OR PERHAPS
AS EARLY AS LATE THIS AFTERNOON. THE HRRR SHOWS WEAK TO MODERATE
REFLECTIVITIES OVER THE I-25 URBAN CORRIDOR AS EARLY AS 21Z/TODAY...
WHILE AT THE SAME TIME THE WRF AND NAM ONLY INDICATE WIDELY
SCATTERED WEAK ECHOS OVER THE FOOTHILLS AND PALMER DIVIDE.
HOWEVER ALL 3 MODELS INDICATE SEVERAL AREAS OF LIGHT TO MODERATE
REFLECTIVITY/QPF OVER THE FRONT RANGE AND OUT ACROSS THE NERN
PLAINS THIS EVENING. COULD SEE A FEW STRONG T-STORMS POP ON THE
PLAINS AROUND 00Z/MON JUST AHEAD OF THE COLD FRONT. NAM AND RAP
INDICATE AN ELONGATED AREA OF 750-1000 J/KG CAPE EXTENDING FROM
ELBERT COUNTY TO LOGAN COUNTY AROUND 00Z.
NAM AND GFS INDICATE THE GREATEST REFLECTIVITIES/QPF IN THE
N-CENTRAL MTNS AROUND SUMMIT COUNTY FROM 00Z-06Z THIS EVENING
WITH CAA FOLLOWING THE PASSAGE OF THE 700-500 TROUGH AXIS. QPF
TOTALS UP ALONG THE CONTINENTAL DIVIDE ON THE ORDER OF 0.35 TO
0.60 INCH BY MORNING. MODEL SNOW TOTALS RANGE FROM 1-4 INCHES IN
AREAS ROUGHLY ABOVE 9500 FEET. ELSEWHERE...SHOULD SEE AN END TO
THE SHOWERY PRECIP OVER AND NEAR THE EAST FACE OF THE FRONT RANGE
BY AROUND MIDNIGHT WITH THE DRYING EFFECTS OF DOWNSLOPE FLOW.
HOWEVER...FARTHER OUT ON THE PLAINS A TIGHT BAROCLINIC ZONE AND
LINGERING QG ASCENT ON THE BACKSIDE OF THE UPPER LOW WILL PROBABLY
KEEP LIGHT TO MODERATE PRECIP GOING THROUGHOUT THE NIGHT. RAIN
AMOUNTS IN THIS AREA BY MORNING GENERALLY UNDER A HALF INCH...WITH
LESSER AMOUNTS CLOSER IN TO THE FOOTHILLS. FLOODING IS NOT A
CONCERN AT THIS TIME.
TEMPERATURES TODAY ARE EXPECTED TO BE SLIGHTLY COOLER THAN YESTERDAY
BUT STILL SLIGHTLY ABOVE AVERAGE FOR THE DATE. HIGHS ON THE PLAINS
WILL RANGE FROM THE MID-70S NEAR THE FOOTHILLS TO THE MID-80S NEAR
THE NORTHEAST CORNER OF THE STATE. HIGH COUNTRY MAX TEMPS WILL RANGE
FROM THE MID-60S IN THE VALLEYS AND FOOTHILLS...TO AROUND 50 DEGS
ABOVE TIMBERLINE. TONIGHTS LOWS WILL RANGE FROM THE MID 40S/LOWER
50S ON THE PLAINS TO THE 20S/30S IN THE HIGH COUNTRY. GUSTY NWLY
WINDS OVER THE NRN FRONT RANGE OVERNIGHT MAY MAKE IT FEEL EVEN
COLDER THAN THAT.
LONG TERM...RATHER POTENT UPPER LEVEL TROUGH WILL MOVE QUICKLY ACROSS
THE AREA MON MORNING. LOOKS LIKE THIS SYSTEM MAY CLOSE OFF OVER
ERN CO AND THEN MOVE INTO SWRN NE BY MIDDAY. WILL HAVE SOME
FAVORABLE MID LVL QG ASCENT MON MORNING OVER NERN CO WHICH SHOULD
LEAD TO A GOOD CHC OF SHOWERS OVER THE PLAINS. ALONG THE FRONT
RANGE THE LOW LVL FLOW WILL BE STG NWLY WHICH WILL LIMIT PCPN
CHANCES. IN THE MTNS WILL SEE SOME LINGERING SNOW SHOWERS IN THE
MORNING BUT ACTIVITY SHOULD END BY MIDDAY AS DRIER AIR SPREADS
ACROSS. AS THE UPPER LEVEL LOW INTENSIFIES OVER SWRN NE AND DECENT
SFC GRADIENT OCCURS WILL SEE GUSTY NWLY WINDS IN THE NRN FOOTHILLS
AND ACROSS THE PLAINS. FOR NOW WILL KEEP SPEEDS BLO HIGH WIND
CRITERIA. AS FOR HIGHS WILL KEEP READINGS IN THE UPPER 60S TO
LOWER 70S OVER NERN CO.
BY MON EVENING THE UPPER LEVEL SYSTEM WILL MOVE QUICKLY EASTWARD
WITH DIMINISHING WINDS AND PCPN ENDING OVER THE FAR NERN PLAINS.
FOR TUE AND WED THE FLOW ALOFT WILL BECOME MORE SWLY AS ANOTHER
UPPER LEVEL TROUGH DEVELOPS OVER THE WRN US. THIS WILL LEAD TO A
DRY WX PTRN WITH WARMER TEMPS. HIGHS BY WED WILL BE IN THE LOWER TO
MID 80S OVER NERN CO.
BY THU ONE PIECE OF THE UPPER LEVEL TROUGH OVER THE WRN US WILL
MOVE ACROSS THE NRN ROCKIES WHILE A SECOND PIECE OF ENERGY MOVES
INTO THE GREAT BASIN. THIS WILL LEAVE NRN CO IN SWLY FLOW ALOFT.
SOME MOISTURE WILL INCREASE IN THE MTNS HOWEVER IT APPEARS BEST
CHC OF PCPN THU AFTN WILL STAY MAINLY OVER WRN CO THRU THU NIGHT.
HIGHS ON THU WILL REMAIN ABV NORMAL OVER NERN CO.
FOR FRI THE UPPER LEVEL TROUGH OVER THE GREAT BASIN WILL BEGIN TO
MOVE EAST AS A COLD FRONT MOVES INTO NERN CO. SHOULD SEE A GOOD
CHANCE OF RAIN AND SNOW IN THE MTNS WITH A CHC OF RAIN OVER NERN CO.
HIGHS ON FRI WILL TURN COOLER WITH READINGS IN THE 60S OVER THE
PLAINS. THE UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA BY SAT
WITH DRIER WEATHER AND SEASONAL TEMPERATURES.
AVIATION...SCATTERED HIGH CLOUDS EARLY THIS MORNING OVER THE
DENVER METRO AREA WILL GRADUALLY LOWER AS CLOUDS INCREASE IN
ADVANCE OF A PACIFIC COLD FRONT AND UPPER LEVEL LOW PRESSSURE
TROUGH TO OUR WEST. SOUTH-SOUTHWEST SFC WINDS OF 6-13KTS THIS
MORNING WILL GRADUALLY TURN EAST-SOUTHEASTERLY LATE MORNING/EARLY
AFTERNOON AS THE SURFACE TROUGH ALONG THE FOOTHILLS DEEPENS AHEAD
OF THE COLD FRONT. WESTERN PORTIONS OF THE DENVER METRO AREA
INCLUDING APA COULD SEE ISOLATED TO SCATTERED RAIN SHOWERS/
T-STORMS FORMING AFTER 21Z TODAY WITH THE ATMOSPHERE BECOMING
INCREASINGLY UNSTABLE. HOWEVER IT APPEARS THAT DENVER AREA
TERMINALS WILL SEE THEIR BEST CHANCE FOR SHOWERS/T-SHOWERS THIS
EVENING FROM 00Z-06Z JUST PRIOR TO AND SHORTLY AFTER PASSAGE OF
THE PACIFIC COLD FRONT. THE STRONGEST STORMS WILL LIKELY FORM
EAST OF THE METRO AREA WHERE THE LOWER ATMOSPHERE WILL BE MORE
MOIST AND UNSTABLE. CLOUD CEILINGS COULD BRIEFLY LOWER TO AROUND
5000 FT AGL WITH MODERATE RAINFALL THIS EVENING. EXPECT WINDS
AROUND SHOWERS/T-SHOWERS TO ALSO BE QUITE GUSTY AND VARIABLE IN
DIRECTION. CEILINGS SHOULD BEGIN RISING WITH SHOWERS ENDING AFTER
MIDNIGHT AS DRIER AIR MOVES IN BEHIND THE COLD FRONT.
HOWEVER...DIA COULD POSSIBLY SEE CIGS LOWERING AGAIN TO AROUND
3000 FT AGL WITH STRATUS TOWARDS MORNING. THE STRATUS WILL BE A
PRODUCT OF MOIST OUTFLOW FROM SHOWERS FARTHER OUT ON THE PLAINS.
HYDROLOGY...SCATTERED TO LIKELY SHOWERS AND ISOLATED TO SCATTERED
THUNDERSTORMS IN THE HIGH COUNTRY THIS AFTERNOON COULD PRODUCE
RAINFALL AMOUNTS RANGING FROM A QUARTER TO ONE-HALF INCH. SIMILAR
RAIN AMOUNTS ARE POSSIBLE ON THE PLAINS AND OVER THE FOOTHILLS
LATE THIS AFTERNOON AND EVENING. SHOWERS AND STORMS WILL MOVE
FAIRLY QUICKLY TODAY AND SO THE RISK OF HEAVY RAINFALL LEADING TO
FLASH FLOODING IS LOW. IN THE HIGH COUNTRY...ELEVATIONS ABOVE
AROUND 9500 FEET COULD SEE 2-4 INCHES OF SNOW ACCUMULATE BY
MORNING. AREAS ABOVE TIMBERLINE AS WELL AS WEST AND NORTHWEST
FACING SLOPES ARE IN THE BEST POSITION TO SEE THIS ACCUMULATION.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....RPK
AVIATION/UPDATE...GIMMESTAD
AREA FORECAST DISCUSSION
NWS NEW YORK NY
137 PM EDT SUN SEP 22 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE CONTROLS OF OUR WEATHER THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASIC FORECAST ON TRACK. MINOR CHANGES TO SKY COVER AND DEW POINT
TEMPERATURES WITH THIS UPDATE. CLOUDS FROM LOW LEVEL INSTABILITY
ARE SOMEWHAT MORE THAN EXPECTED. INCREASED SKY COVER GRIDS ABOUT
20 PERCENT ON AVERAGE USING LATEST 15Z RAP AS THE BASELINE.
TEMPS ON TRACK FOR HOLDING NEARLY STEADY THIS AFTERNOON IN THE
UPPER 60S TO LOWER 70S. DEW POINTS IN THE MID 40S SPREADING EAST
ACROSS LI AND CT.
RIP CURRENT RISK WAS LOWERED TO MODERATE BASED ON LATEST
OBSERVATIONS AND FORECAST DATA. LIFEGUARDS ARE NOT ON DUTY AT MOST,
IF NOT ALL OCEAN BEACHES. SWIMMING IS NOT RECOMMENDED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
UPPER TROUGH CLOSES OFF AND GETS BLOCKED OVER THE CANADIAN
MARITIMES. UPPER RIDGE BUILDS TO THE WEST OF THE AREA...AS SFC HIGH
BUILDS ACROSS THE GREAT LAKES.
INSTABILITY CLOUDS DISSIPATE WITH THE LOSS OF HEATING THIS
EVENING. WINDS STAY UP OVERNIGHT AS CAA CONTINUES WITH A SLIGHTLY
STRONGER PRESSURE GRADIENT FORCE. THIS KEEPS TEMPS IN THE 40S TO
AROUND 50 IN NYC.
THE FIRST FULL DAY OF FALL FEATURES TEMPS 5-7 DEGREES BELOW NORMAL
UNDER COBALT BLUE SKIES AND A FEW WEATHER STRATO-CU.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
UPPER LEVEL BLOCKED ACROSS THE CANADIAN MARITIMES THROUGH MID WEEK.
THERE WILL BE A SPLIT IN THE FLOW WITH A WEAKENING RIDGE MOVING
ACROSS THE REGION FROM EARLY TO MID WEEK WITH CANADIAN HIGH PRESSURE
BUILDING IN AT THE SURFACE. THEN A DAMPENED UPPER LEVEL SHORTWAVE
PUSHES TO THE SOUTH OF THE REGION WEDNESDAY AND THURSDAY WITH A
WEAKENING OF THE SURFACE PRESSURE FIELD. THIS WILL RESULT IN SOME
MORE CLOUDS FOR THAT TIME FRAME. ANOTHER RIDGE BUILDS IN FROM THE
WEST THURSDAY NIGHT THROUGH EARLY NEXT WEEKEND...REINFORCING
SUBSIDENCE WITH ANOTHER CANADIAN HIGH PRESSURE AREA AT THE SURFACE
BUILDING IN.
THIS WILL BE A QUIET WEATHER PERIOD WITH DRY CONDITIONS AND NEAR TO
SLIGHTLY BELOW NORMAL TEMPERATURES MUCH OF THE TIME. HOWEVER...THE
END OF THE WEEK WILL SEE A SLIGHT WARMING TREND TO SLIGHTLY ABOVE
NORMAL TEMPS. EXPECTING THE NIGHT TIME PERIODS TO EXPERIENCE GOOD
RADIATIONAL COOLING CONDITIONS MONDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH MONDAY NIGHT BEING THE COLDEST NIGHT. INTERIOR
AREAS...WHERE WINDS WILL BE LIGHTER...COULD SEE SOME PATCHY FROST
LATE MONDAY NIGHT INTO EARLY TUESDAY MORNING.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH PRES BUILDS INTO THE REGION.
NW WINDS AT AROUND 15 KT WITH GUSTS UP TO 20 KT. FOR
KJFK/KLGA/KEWR...WINDS WILL BE TO THE RIGHT OF 310 MAGNETIC
THROUGH THIS EVENING.
GUSTS END AFT 23Z. NW WINDS AROUND 15 KT WITH GUSTS UP TO 20 KT
AFT 14Z MONDAY.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
.MONDAY AFTERNOON...VFR. NW WINDS GUSTING TO 20 KT.
.TUESDAY THROUGH FRIDAY...VFR.
&&
.MARINE...
NW WINDS SHOULD BELOW SCA CONDITIONS THIS AFTERNOON WITH NW GUSTS
TO AROUND 20 KT. THIS SUBSIDE SLIGHTLY TOWARD LATE AFTN.
A TIGHTENING OF THE PRESSURE GRADIENT THIS EVENING RESULTS IN 25
KT GUSTS ALL WATERS (SCA ADVISORY UP FOR THIS)...THEN WINDS
DIMINISH BELOW SCA LEVELS BY SUNRISE.
TRANQUIL WEATHER CONDITIONS ARE FCST FOR MONDAY THROUGH THURSDAY WITH
WINDS AND SEAS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS.
&&
.HYDROLOGY...
DRY THROUGH THE WEEK.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST
CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION
KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING
WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL
PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY
FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS
WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND
TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED.
THE KOKX WSR-88D DUAL POLE RAINFALL ESTIMATES WERE INFLATED BY A
FACTOR OF 3 OR MORE DURING LAST NIGHT`S PCPN EVENT. TECHNICIANS
WILL INVESTIGATE THIS ON MONDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT MONDAY
FOR ANZ330-335-338-340-345-355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE/PW
LONG TERM...JM/PW
AVIATION...MPS
MARINE...TONGUE
HYDROLOGY...TONGUE
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1252 PM EDT SUN SEP 22 2013
.SYNOPSIS...
CANADIAN HIGH PRESSURE CONTROLS OF OUR WEATHER THROUGH THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASIC FORECAST ON TRACK. MINOR CHANGES TO SKY COVER AND DEW POINT
TEMPERATURES WITH THIS UPDATE. CLOUDS FROM LOW LEVEL INSTABILITY
ARE SOMEWHAT MORE THAN EXPECTED. INCREASED SKY COVER GRIDS ABOUT
20 PERCENT ON AVERAGE USING LATEST 15Z RAP AS THE BASELINE.
TEMPS ON TRACK FOR HOLDING NEARLY STEADY THIS AFTERNOON IN THE
UPPER 60S TO LOWER 70S. DEW POINTS IN THE MID 40S SPREADING EAST
ACROSS LI AND CT.
RIP CURRENT RISK WAS LOWERED TO MODERATE BASED ON LATEST
OBSERVATIONS AND FORECAST DATA. LIFEGUARDS ARE NOT ON DUTY AT MOST,
IF NOT ALL OCEAN BEACHES. SWIMMING IS NOT RECOMMENDED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
UPPER TROUGH CLOSES OFF AND GETS BLOCKED OVER THE CANADIAN
MARITIMES. UPPER RIDGE BUILDS TO THE WEST OF THE AREA...AS SFC HIGH
BUILDS ACROSS THE GREAT LAKES.
INSTABILITY CLOUDS DISSIPATE WITH THE LOSS OF HEATING THIS
EVENING. WINDS STAY UP OVERNIGHT AS CAA CONTINUES WITH A SLIGHTLY
STRONGER PRESSURE GRADIENT FORCE. THIS KEEPS TEMPS IN THE 40S TO
AROUND 50 IN NYC.
THE FIRST FULL DAY OF FALL FEATURES TEMPS 5-7 DEGREES BELOW NORMAL
UNDER COBALT BLUE SKIES AND A FEW WEATHER STRATO-CU.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
UPPER LEVEL BLOCKED ACROSS THE CANADIAN MARITIMES THROUGH MID WEEK.
THERE WILL BE A SPLIT IN THE FLOW WITH A WEAKENING RIDGE MOVING
ACROSS THE REGION FROM EARLY TO MID WEEK WITH CANADIAN HIGH PRESSURE
BUILDING IN AT THE SURFACE. THEN A DAMPENED UPPER LEVEL SHORTWAVE
PUSHES TO THE SOUTH OF THE REGION WEDNESDAY AND THURSDAY WITH A
WEAKENING OF THE SURFACE PRESSURE FIELD. THIS WILL RESULT IN SOME
MORE CLOUDS FOR THAT TIME FRAME. ANOTHER RIDGE BUILDS IN FROM THE
WEST THURSDAY NIGHT THROUGH EARLY NEXT WEEKEND...REINFORCING
SUBSIDENCE WITH ANOTHER CANADIAN HIGH PRESSURE AREA AT THE SURFACE
BUILDING IN.
THIS WILL BE A QUIET WEATHER PERIOD WITH DRY CONDITIONS AND NEAR TO
SLIGHTLY BELOW NORMAL TEMPERATURES MUCH OF THE TIME. HOWEVER...THE
END OF THE WEEK WILL SEE A SLIGHT WARMING TREND TO SLIGHTLY ABOVE
NORMAL TEMPS. EXPECTING THE NIGHT TIME PERIODS TO EXPERIENCE GOOD
RADIATIONAL COOLING CONDITIONS MONDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH MONDAY NIGHT BEING THE COLDEST NIGHT. INTERIOR
AREAS...WHERE WINDS WILL BE LIGHTER...COULD SEE SOME PATCHY FROST
LATE MONDAY NIGHT INTO EARLY TUESDAY MORNING.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR AS HIGH PRESSURE BUILDS IN WITH NW FLOW.
FOR JFK...LGA AND EWR: WINDS STAY RIGHT OF 310 MAGNETIC THROUGH
THIS EVENING WITH GUSTS TO AROUND 20 KT.
OUTLOOK FOR 18Z MONDAY THROUGH THURSDAY...
.MON AFTN...VFR WITH NNW WND AROUND 15 KT.
.TUE THROUGH THU...VFR.
&&
.MARINE...
NW WINDS SHOULD BELOW SCA CONDITIONS THIS AFTERNOON WITH NW GUSTS
TO AROUND 20 KT. THIS SUBSIDE SLIGHTLY TOWARD LATE AFTN.
A TIGHTENING OF THE PRESSURE GRADIENT THIS EVENING RESULTS IN 25
KT GUSTS ALL WATERS (SCA ADVISORY UP FOR THIS)...THEN WINDS
DIMINISH BELOW SCA LEVELS BY SUNRISE.
TRANQUIL WEATHER CONDITIONS ARE FCST FOR MONDAY THROUGH THURSDAY WITH
WINDS AND SEAS REMAINING BELOW SMALL CRAFT ADVISORY LEVELS.
&&
.HYDROLOGY...
DRY THROUGH THE WEEK.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY BROADCAST
CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION
KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER SERVICE IS WORKING
WITH SEVERAL U.S. GOVERNMENT AGENCIES TO ISOLATE AND RESOLVE THIS TECHNICAL
PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE INTERMITTENTLY
FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO DURING POTENTIALLY DANGEROUS
WEATHER SITUATIONS...FOR ROUTINE WEEKLY TESTS OF THE WARNING SYSTEM...AND
TO DETERMINE IF THE INTERFERENCE ISSUE HAS BEEN RESOLVED.
THE KOKX WSR-88D DUAL POLE RAINFALL ESTIMATES WERE INFLATED BY A
FACTOR OF 3 OR MORE DURING LAST NIGHT`S PCPN EVENT. TECHNICIANS
WILL INVESTIGATE THIS ON MONDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT MONDAY
FOR ANZ330-335-338-340-345-355.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE/PW
LONG TERM...JM/PW
AVIATION...MPS
MARINE...TONGUE
HYDROLOGY...TONGUE
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
148 PM EDT SUN SEP 22 2013
.SYNOPSIS...
ISSUED AT 358 AM EDT SUN SEP 22 2013
HIGH PRESSURE BEGIN TO TAKE CONTROL OF THE WEATHER ACROSS THE
GREAT LAKES TODAY AND WILL PERSIST INTO THE UPCOMING WEEK. LAKE
EFFECT CLOUDS WILL SLOWLY BREAK UP TODAY WITH ALL AREAS BECOMING
MOSTLY CLEAR BY TONIGHT. HIGH TEMPERATURES WILL BE COOL AGAIN TODAY
AND REMAIN IN THE 60S. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
AND LOWER 40S.
&&
.UPDATE...
ISSUED AT 120 PM EDT SUN SEP 22 2013
HAVE MADE SOME RELATIVELY MINOR UPDATES AT MIDDAY. UPSTREAM CLOUD
COVER WAS ALREADY SPREADING INTO FAR SOUTHERN LOWER MICHIGAN AND
SPILLING OVER INTO NW INDIANA. RAPID REFRESH ABOUT THE ONLY MODEL
THAT APPEARS TO BE HANDLING THIS SCENARIO WHERE UPSTREAM MOISTURE
FLUX FROM LAKE SUPERIOR AND NRN LAKE MICHIGAN WAS REALLY HAVING A
IMPACT ON CLOUD COVER. CLOUD COVER OVER 80 PERCENT OVER WESTERN
LOWER MICHIGAN WITH CLOUDS NEAR THE BASE OF THE SUBSIDENCE INVERSION.
A 1540Z ACFT SOUNDING FROM GRR SHOWS CLOUD DEPTH QUITE LIMITED.
THE LATEST SATELLITE SHOWS SUBSIDENCE APPARENTLY ENOUGH FOR SOME
CLEARING NORTH OF BEH. FOR NOW...INCREASED CLOUD MAINLY NORTH AND
NORTHEAST AREAS...BUT HAVE CLEARING EARLY TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM EDT SUN SEP 22 2013
LAKE EFFECT CLOUDS HAVE MOVED WELL INLAND THANKS TO A STRONG
TRAPPING SUBSIDENCE INVERSION AND A NNW LOW LEVEL WIND. SATELLITE
SHOWS A RATHER LARGE AREA OF STRATOCUMULUS AS FAR SOUTH AS MUNCIE
AT 07Z AND STILL EXPANDING SOUTHWARD. ONLY MODEL TO HAVE A DECENT
HANDLE ON THESE CLOUDS IS THE HRRR WITH RUC13 PLAYING CATCHUP.
DELTA T VALUES INTO THE MID TEENS OVER SOUTHERN LAKE MICHIGAN WITH
850MB TEMPS DOWN TO ABOUT +3C AND MID LAKE TEMP RUNNING AROUND
20C. LACK OF DEEP MOISTURE AND THE STRONG INVERSION SEEMS TO BE
KEEPING ANY SHOWERS FROM DEVELOPING PER REGIONAL RADAR MOSAIC.
WILL RELY ON SATELLITE AND HRRR TRENDS FOR CLOUD COVER THIS
MORNING WHILE KEEPING PCPN OUT OF FORECAST.
SHOULD SEE SUBSIDENCE AND VEERING LOW LEVEL WINDS HELP ERODE EASTERN
FLANK OF CLOUD SHIELD THIS MORNING. ALREADY SEEING A LITTLE BIT OF
THIS WITH THINNING AND A FEW BREAKS DEVELOPING ON SATELLITE OVER
SOUTH CENTRAL MI AND NE INDIANA AT 08Z. TRAJECTORIES SUGGEST CLOUDS
WILL PERSIST OVER WESTERN THIRD OF CWA THROUGH THE MORNING WITH A
LIKELY TREND TOWARD BECOMING CELLULAR WITH MORE BREAKS BY AFTERNOON.
THIS SEEMS REASONABLE GIVEN SHALLOW NATURE OF MOISTURE AND CLOUDS.
SKIES EXPECTED TO BECOME MOSTLY CLEAR TONIGHT WITH HIGH PRESSURE
MOVING OVERHEAD ALONG WITH UPPER LEVEL RIDGE.
TEMPS WILL BE COOL AGAIN TODAY WITH HIGHS ONLY REACHING THE LOW TO
MID 60S ACROSS THE AREA. LOWS TONIGHT WILL DROP INTO THE UPPER 30S
TO LOWER 40S WITH CLEAR SKIES AND LIGHT WINDS. SIDED TOWARD COOLER
GUIDANCE NUMBERS GIVEN EXPECTED RADIATIONAL COOLING.
&&
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 AM EDT SUN SEP 22 2013
SLOW WARMING TREND REMAINS IN STORE FOR MUCH OF THE UPCOMING WEEK AS
UPPER LEVEL RIDGING MOVES INTO THE REGION. TROUGH OVER THE PLAINS
WILL MOVE EAST WITH MAIN UPPER SUPPORT REMAINING WELL NORTH OF THE
AREA. MODELS DO SHOW AN ORPHANED TROUGH THAT MIGRATES ACROSS THE
LOWER GREAT LAKES TUES NGT/WEDS...BUT LIMITED FORCING AND MSTR WITH
THE FEATURE SHOULD KEEP AWAY ANY PRECIP.
UPPER FLOW WILL RESPOND TO DEEPENING TROUGH IN THE WESTERN STATES AS
RIDGING BUILDS ACROSS THE EASTERN PLAINS INTO THE GREAT LAKES INTO
AT LEAST FRIDAY WITH TEMPS CLIMBING TO ABOVE NORMAL LEVELS IN THE
MID 70S. FORECAST DETAILS FOR SATURDAY AND BEYOND REMAIN MUDDLED AS
DEEP TROUGH EJECTS TOWARDS THE REGION WITH MODELS CONTINUING TO VARY
ON TIMING/STRENGTH/IMPACT TO THE AREA. ALL MED RANGE MODELS LIFT
BULK OF THE ENERGY NE INTO THE UPPER PLAINS/NORTHERN GREAT LAKES
WITH SOUTHERN EXTENT OF THE ENERGY RATHER VARIABLE. GFS/GEFS REMAIN
MOST AGGRESSIVE WITH TROUGH SWEEPING ACROSS SAT NGT INTO SUNDAY WITH
SHOWERS/STORMS...ALTHOUGH PROBS FOR PRECIP WITH GEFS STILL 60% OR
LESS. 12Z RUN OF ECMWF HAD A RATHER DRAMATIC SHIFT WITH ENERGY
SHIFTING NORTH AND THEN WAVE DROPPING BACK INTO THE WESTERN GREAT
LAKES AS A CUT OFF UPPER LOW. 00Z SOLUTION HAS BACKED OFF FROM THIS
AND SIMPLY FLATTENS THE RIDGE ACROSS THE REGION WITH NO PRECIP.
CONFIDENCE LOW DURING THIS PERIOD...WARRANTING CONTINUED BUCKING OF
TRENDS TO ADD POPS BY CR ALLBLEND WHICH IS HEAVILY BIASED TOWARDS
THE GFS SOLUTIONS...THE WETTEST SOLUTION AS NOTED ABOVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 120 PM EDT SUN SEP 22 2013
UPSTREAM CLOUD COVER WAS ALREADY SPREADING INTO FAR SOUTHERN
LOWER MICHIGAN AND SPILLING OVER INTO NRN INDIANA WHERE SBN WAS
BKN 037. RAPID REFRESH ABOUT THE ONLY MODEL THAT APPEARS TO BE
HANDLING THIS SCENARIO WHERE UPSTREAM MOISTURE FLUX FROM LAKE
SUPERIOR AND NRN LAKE MICHIGAN WAS REALLY HAVING A IMPACT ON CLOUD
COVER. CLOUD COVER OVER 80 PERCENT OVER WESTERN LOWER MICHIGAN
WITH CLOUDS NEAR THE BASE OF THE SUBSIDENCE INVERSION. A 1540Z
ACFT SOUNDING FROM GRR SHOWS CLOUD DEPTH QUITE LIMITED. THE LATEST
SATELLITE SHOWS SUBSIDENCE APPARENTLY ENOUGH FOR SOME CLEARING
NORTH OF BEH. FOR NOW...INCREASED CLOUD COVER AT SBN...BUT KEPT
CONDITIONS VFR.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...SKIPPER
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...SKIPPER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
619 PM EDT SUN SEP 22 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THIS WEEK.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
615 PM UPDATE...
INCREASED CLOUDS ACROSS NORTHERN COUNTIES OVERNIGHT. CONTINUED NW
FLOW OFF THE LAKE. HRRR ALSO ADVERTISING CLOUDS TO ERODE EXCEPT
NW. AS A RESULT...DROPPED MENTION OF FROST FOR EXTREME NE AREA
TONIGHT WITH INCREASE IN CLOUDS. ALSO DROPPED VALLEY FOG ACROSS
NORTH AND KEPT IT ACROSS SOUTHERN ONE HALF TO TWO THIRDS OF CWA.
ADJUSTED TEMP AND TD TREND.
PREVIOUS DISCUSSION FOLLOWS...NW FLOW ACRS THE GT LKS AND COOL
AIR ALOFT WL CONT TO BRING BKN- OVC STRATOCU INTO THE EVE. THIS
SHOULD GRDLY SCT OUT AS FLOW EVENTUALLY TURNS MORE NE OVRNGT.
RIDGING WL STRENGTHEN THRU MON NGT AS WELL. TEMPS MAY BE COLD
ENOUGHT TNGT AND MON NGT FOR SOME PTCHY FROST INVOF N OF FKL-
DUJ...BUT COVG SHOULD BE PTCHY ENOUGH FOR NO ADVISORIES ATTM.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
H5 RDG AXIS OVER OHVLY WILL FLATTEN TUE AS SHRTWV TROF ADVCS EWD
FROM WRN GRTLKS RGN. MSTR RETURN XPCD TO RMN LMTD...WHICH WILL IN
TURN LMT PCPN POTL WITH THE PASSAGE OF THIS WAVE.
WITH HIPRES DOMINANT ON TUE...NIL POPS WERE CONTD. POPS INCR WED
IN SRN ZONES OWING TO THEIR PROXIMAL LOCATION TO LOW-LVL MSTR AMID
WAVE PASSAGE. GUIDANCE INDICATES AT LEAST LOW PSBLTY OF LGT PCPN
DURG THIS TIME...BUT NWD EXTENT OF ANY PCPN WILL BE RESTRICTED BY
WAVE TRAJECTORY AND MSTR.
TEMPS WILL RECOVER MODESTLY TUE AND WED. MAXIMA GENLY IN THE MID
60S-LWR 70S LKLY BOTH DAYS...PSBLY WARMING INTO THE MID 70S ON WED
IF CLD CVR RMNS SPARSE. KRAMAR
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH PRES WL REMAIN ACRS THE RGN THRU SAT WITH DRY WEA EXPD. AN
APRCHG CDFNT WL INCRS SHWR CHCS BY SUN. ABV SEASONAL AVG TEMPS ARE
EXPD THRU THE PD.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
NW FLOW ACRS THE GT LKS AND COOL AIR ALOFT WL BRING BKN VFR
CU/STRATOCU TDA. CIGS SHOULD GRDLY SCT OUT TNGT WITH LOSS OF
DAYTIME HEATING AND AS FLOW TURNS NE. MAINTAINED MVFR/IFR RIVER
VLY FG LT TNGT/MON MRNG AT SELECTED PORTS...OTRW ONLY SCT DIURNAL
CU EXPD MON.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
VFR CONDS ARE EXPD THRU THE PD UNDER HIGH PRES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
136 PM EDT SUN SEP 22 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 323 AM EDT SUN SEP 22 2013
HIGH PRESSURE WILL MOVE OVER THE REGION THROUGH THE FIRST PART OF
THIS WEEK. THIS SYSTEM WILL BRING SUNNY AND MILD DAYS AND CHILLY
NIGHTS. FROST WILL BE POSSIBLE TONIGHT NORTH OF I-96.
TEMPERATURES WILL SLOWLY WARM INTO THE LATTER PART OF THE WEEK. THE
NEXT CHANCE OF RAIN SHOULD HOLD OFF UNTIL SATURDAY.
&&
.UPDATE...
ISSUED AT 1040 AM EDT SUN SEP 22 2013
IT IS CLEAR TO ME (PUN INTENDED) THE SKIES WILL IN FACT NOT BE
CLEAR ANY TIME SOON. THE AREA OF STRATOCUMULUS CLOUDS CONTINUES TO
EXPAND SOUTHWARD OVER THE SOUTHERN AND SOUTHWEST CWA. GIVEN THE
LACK OF ANY TREND FOR THE CLOUDS TO BREAK UP SOON I HAVE UPDATED
THE ZONES TO KEEP THE CLOUDS AROUND INTO EARLY THIS AFTERNOON. THE
LATEST MODEL RUNS... LIKE THE RAP AND THE OUTGOING LONGWAVE
RADIATION FEATURE ON THE HRRR 12Z RUN SUGGEST THE CLEARING WILL BE
MORE IN THE 2 TO TO 5 PM TIME FRAME. SO THAT IS WHERE I NOW HAVE
IT IN THE GRIDS. IF THE CLOUDS DO HANG AROUND INTO MID AFTERNOON
THE HIGHS WILL ONLY BE THE 50S... I LOWERED THE AFTERNOON TEMPS
ABOUT 2 DEGREES BUT THAT MAY NOT BE ENOUGH. WE SHALL SEE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
FIRST CHALLENGE IN THE SHORT TERM WAS DETERMINING WHEN THE CLOUDS
OVER THE REGION WILL FINALLY CLEAR. THEN FROST/FREEZE POTENTIAL
BECOMES A CONCERN TONIGHT.
THE UPPER LOW OVER WESTERN QUEBEC CONTINUES TO BRING CHILLY NW FLOW
OVER THE REGION. THE COMBINATION OF MOISTURE WRAPPING AROUND THIS
LOW AND LAKE DELTA T/S AROUND 18...HAS HELD IN A SC DECK INTO EARLY
THIS MORNING. HOWEVER AS THE LOW SHIFTS TO EASTERN QUEBEC LATER
TODAY...SURFACE AND UPPER RIDGING MOVES INTO THE WESTERN GREAT LAKES
ALONG WITH WARM ADVECTION ALOFT BY AFTERNOON. SO BELIEVE THE CLOUDS
WILL ERODE FAIRLY QUICKLY ONCE THE SUN IS UP...AND MOSTLY SUNNY
SKIES CAN BE EXPECTED CWA-WIDE BY LATE MORNING.
THE SURFACE RIDGE WILL SIT OVER THE CWA TONIGHT BRINGING CLEAR SKIES
AND LIGHT WINDS. THIS WILL BE IDEAL RADIATION CONDITIONS AND
FROST/FREEZE HEADLINES WILL BE POSTED ACROSS THE NORTHERN CWA.
PATCHY FROST WILL BE POSSIBLE OVER THE SOUTHERN HALF TOO...BUT IT
SHOULD BE ISOLATED ENOUGH TO NOT WARRANT HEADLINES.
LITTLE WEATHER TO SPEAK OF FOR MONDAY AND TUESDAY. THE UPPER FLOW
REMAINS FAIRLY AMPLIFIED WHICH WILL KEEP THE PATTEN BLOCKED AND KEEP
THE SURFACE AND UPPER RIDGE NEARBY. TEMPS SHOULD MODERATE EACH
DAY...TO 70 TO 75 BY TUESDAY. FROST SHOULD LESS OF A THREAT MONDAY
NIGHT WITH SE LOW LEVEL FLOW DEVELOPING.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 AM EDT SUN SEP 22 2013
WARM AND DRY IS THE MAIN MESSAGE IN THE LONG TERM PERIOD AS A HIGH
AMPLITUDE UPPER LEVEL RIDGE DOMINATES OUR WEATHER. THIS FEATURE WILL
LEAD TO TEMPERATURES ABOUT 10 DEGREES ABOVE NORMAL WITH HIGHS IN THE
MID TO UPPER 70S AND LOWS IN THE 50S.
HAVE REMOVED THE LOW CHANCE OF SHOWERS FOR FRIDAY NIGHT BUT LEFT
THEM IN FOR SATURDAY DUE TO THE WET LOOK OF THE GFS. THE EURO ON THE
OTHER HAND IS A DAY SLOWER WITH THE FRONT AND SUGGESTS THE BETTER
RAIN CHANCES WOULD HOLD OFF UNTIL SATURDAY NIGHT OR SUNDAY. THIS MAY
BE MORE REASONABLE GIVEN THE HIGHLY AMPLIFIED UPPER RIDGE SO PERHAPS
IN FUTURE FORECASTS WE CAN GO DRY ON SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 134 PM EDT SUN SEP 22 2013
MVFR CIGS WILL IMPROVE TO VFR LATER THIS AFTERNOON BEFORE SKIES
SCATTER OUT THIS EVENING.
&&
.MARINE...
ISSUED AT 1124 AM EDT SUN SEP 22 2013
THE SMALL CRAFT ADVISORY HAS EXPIRED. WINDS ARE NOW GENERALLY
UNDER 10 KNOTS AND WAVE FOR THE MOST PART UNDER 2 FEET.
&&
.HYDROLOGY...
ISSUED AT 323 AM EDT SUN SEP 22 2013
NO RAIN IS EXPECTED UNTIL NEXT WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ039-040.
FROST ADVISORY FROM 2 AM TO 9 AM EDT MONDAY FOR MIZ037-038-
044>046-051.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...93
HYDROLOGY...JK
MARINE...WDM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
658 PM EDT SUN SEP 22 2013
.SYNOPSIS...
LAKE EFFECT SHOWERS WILL DISSIPATE THIS EVENING. OVERNIGHT LOWS
WILL DROP INTO THE 30S AND MAY ALLOW PATCHY FROST TO DEVELOP IN
THE CENTRAL SOUTHERN TIER AND WESTERN CATSKILLS OF NEW YORK. HIGH
PRESSURE WILL BUILD IN TOMORROW AND ALLOW AREAS OF FROST TO
DEVELOP ON TUESDAY MORNING. DRY WEATHER WILL BE IN PLACE INTO NEXT
WEEKEND WITH MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH MONDAY/...
7 PM UPDATE...LATEST SATELLITE PICS SHOW STRATO CU HOLDING TUFF
ACROSS THE CWA. LATEST RAP SOUNDINGS SUGGEST MOSTLY CLOUDY SKIES
FOR MUCH OF THE FA OVERNIGHT WHILE THE NAM WOULD INDICATE SKIES
BECOMING PARTLY CLOUDY TO MAINLY CLEAR. LOW LEVEL FLOW IS EXPECTED
TO VEER OVERNIGHT TO A N/NNW DIRECTION. LAKE/T85 DIFFERENTIAL
ENOUGH TO SUPPORT LAKE CLOUDS, CURRENT THINKING IS MUCH OF THE AREA
WILL GRADUALLY BECOME PARTLY CLOUDY DURING THE EVENING WITH THE
MOST PERSISTENT CLOUDS ACROSS THE FINGER LAKES REGION INTO THE
CENTRAL SOUTHERN TIER DUE TO LOW LEVEL FLOW. ONLY ADJUSTMENT WAS
TO INCREASE CLOUD COVER INTO THE EARLY EVENING HOURS.
2 PM UPDATE...
LK EFFECT SHOWERS WL GRADUALLY WIND DOWN TONIGHT AS VORT MAX EXITS
THE CWA AND DRY AIR WORKS IN AFT MIDNIGHT. FAVORED LK REGIONS WL SEE
JUST ISOLD SHOWERS THRU ABOUT 03Z BFR DIMINISHING ALTOGETHER. CLOUDS
WL BEGIN TO VRY SLOWLY DECREASE AFT THIS TIME, ALLOWING TEMPS TO
FALL INTO THE 30S. CLDR VLY LOCATIONS IN THE CNTRL SRN TIER,
SUSQUEHANNA REGION AND THE WRN CATS MAY SEE PATCHY FROST TONIGHT AS
TEMPS PROGGED TO DROP TO 37F OR LWR. THAT IS, ASSUMING NO FOG DVLPS
TONIGHT. HV NOT ADDED IN PATCHY RVR VLY FOG TO THE GRIDS AT THIS
TIME AS WINDS SHUD STAY UP IN BL ARND 15KTS BUT CANNOT RULE OUT SOME
PATCHY DENSE FOG IN LOWEST VLY AREAS ARND ELMIRA AND SIDNEY. IF THAT
HAPPENS, PATCHY FROST WL BE INHIBITED IN THESE AREAS.
N-NW FLOW WL CONTINUE THRU THE DAY TOMORROW AS 1020MB HIPRES BEGINS
TO BUILD EAST. BL PROGGED TO DRY OUT AFT 18Z WITH MOSTLY-PARTLY SUNNY
SKIES EXPECTED THRU MRNG AS STRATOCU STARTS TO ERODE FM THE EDGES.
GFS H8 RH FIELDS EMULATING CLR SKIES UP NORTH OF LK SUPERIOR AT
PRESENT AND SLOWLY WORKS SOUTH AND EAST THRU 18Z MONDAY. HWVR, WL
NOT BE SO QUICK TO GO CLR DUE TO INFLUENCE OF LAKES AND WL KEEP
PCLDY CONDS THRU MID-MORNING THEN BEGIN CLRNG AFT 16Z AS UL RIDGE
BEGINS TO BUILD IN.
AFTN MAXES WILL TOP OUT ARND 60 ON MONDAY AND WITH MORE SUN EXPECTED
THAN TDA, WINDS SHUD GUST TO BTWN 15-20KTS DRG THE DAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
2 PM UPDATE...
TEMPS ON MON NGT WL QUICKLY FALL OFF UNDER CLR SKIES AND LGT WINDS
DUE TO SFC HIPRES GETTING EVER CLOSER. OVRNGT LOWS EXPECTED TO DROP
TO ARND FRZG IN NOTORIOUSLY CLD LOCATIONS OF SRN TIER AND WRN CATS.
HV ALLOWED FOR PATCHY FROST IN AREAS THAT DROP TO 37F AND AREAS OF
FROST BLO 34F. WL PASS ON TO MIDNIGHT SHIFT ABOUT POSSIBLE FREEZE
WATCH FOR TUE MRNG AND WL CONTINUE TO HIGHLIGHT THREAT IN HWO.
HIPRES RMNS OVR THE AREA THRU THE END OF THE SHORT TERM WITH HIGHS
ON TUE EXPECTED TO CLIMB INTO THE 60S AND LOWS IN THE U30S/ARND 40.
AVG TEMPS DRG THIS TIME WL RUN SLIGHTLY BLO NORMAL DUE TO OVRNGT
LOWS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
130 PM EDT UPDATE...
MINOR ADJUSTMENTS WERE MADE TO THE PREVIOUS FCST AS THE CURRENT
FORECAST APPEARS TO REMAIN DRY. FORECAST ON TRACK WITH STRONG SFC
HIGH BUILDING OVER THE REGION. AND THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS BEING ON SUNDAY WITH ANOTHER APPROACHING STORM
SYSTEM.
230 AM UPDATE...
CURRENT FCST IN GOOD SHAPE...NO CHANGES NEEDED THIS MORNING.
MODEL GUIDANCE CONTINUING TO SUGGEST A FAIRLY DRY PERIOD FOR THE
UPCOMING WEEK AS HIGH PRESSURE REMAINS IN CONTROL. BY LATE
WEEK...EXPECT MODERATING TEMPS AS WARM AIR ADVECTION INCREASES IN
ADVANCE OF THE NEXT STORM SYSTEM PROGGED TO ARRIVE TOWARDS THE END
OF THE WEEKEND. IF CURRENT MODEL TRENDS HOLD TRUE...TEMPS BY NEXT
WEEKEND MAY WARM BACK UP INTO THE LOWER TO MIDDLE 70S FOR DAYTIME
HIGHS. STAY TUNED!
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
130 PM EDT UPDATE...
MVFR AND IFR CIGS CONTINUE TO PREVAIL ACROSS CENTRAL NEW YORK AND
NORTHEAST PENNSYLVANIA THIS AFTERNOON. VERY LIGHT RAIN SHOWERS ARE
ALSO MOVING SE AND EXPECT THESE TO CONTINUE THROUGH 00Z. EMBEDDED
IFR CIGS WITH IFR VSBYS ARE POSSIBLE WITH THESE SHOWERS. CLOUD
COVERAGE THIS AFTERNOON HAS BEEN VERY POTENT WHICH HAS KEPT WIND
GUSTS DOWN... HOWEVER SITES WHERE SUNSHINE MAKING ITS WAY THROUGH
THE DECK WILL SEE GUSTS NEAR 25 KNOTS. THE CLOUDS WILL SLOWLY
DIMINISH AND BECOME VFR BY THIS EVENING.
TONIGHT IS STILL A QUESTIONABLE FORECAST. CLOUD COVERAGE IS
EXPECTED TO DISSIPATE BUT THE QUESTION IS BY HOW MUCH. IF SKIES
CLEAR OUT DENSE FOG IS LIKELY AT KELM WITH IFR VSBYS BUT... IF THE
STRATUS STAYS STUBBORN THEN VSBYS WITH THE FOG MAY REMAIN MVFR.
ALSO... IFR CIGS MAY DEVELOP LATE TOMORROW MORNING FOR MUCH OF THE
AREA BUT CONFIDENCE IS LOW THUS KEPT IFR CIGS AS A TEMPO FOR NOW.
OUTLOOK...
MON-FRI...MAINLY VFR. LATE NIGHT/EARLY MORNING VALLEY FOG POSSIBLE
ESPECIALLY KELM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...CMG/KAH
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
245 PM EDT SUN SEP 22 2013
.SYNOPSIS...
THE COLD FRONT THAT MOVED THROUGH THE REGION EARLY THIS MORNING HAS
MOVED. HIGH PRESSURE WILL BUILD INTO THE REGION AND PERSIST THROUGH
LATE TUESDAY. THE NEXT STORM SYSTEM WILL APPROACH THE AREA ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 PM SUNDAY...
LATEST SURFACE ANALYSIS SHOWS A COLD FRONT AND A WEAK AREA OF LOW
PRESSURE MOVING AWAY FROM THE NC COAST WITH AN AREA OF HIGH PRESSURE
CENTERED OVER THE WESTERN GREAT LAKES. DEEP LAYER MOISTURE LOCATED
OVER THE COASTAL REGION GRADUALLY THINS ACROSS THE COASTAL PLAIN AND
ESPECIALLY THE EASTERN PIEDMONT. A 1708Z AMADAR AIRCRAFT SOUNDING AT
KRDU SHOWS A VERY SHALLOW LAYER OF MOISTURE TRAPPED BELOW THE
INVERSION. VISIBLE SATELLITE IMAGERY SUGGESTS THAT THE
STRATO-CUMULUS ACROSS THE WESTERN PERIPHERY OF THE MAIN CLOUD SHIELD
AND ACROSS THE NORTHERN PIEDMONT IS BEGINNING TO WANE AS THE
MOISTURE BEGINS TO MIX OUT. NWP GUIDANCE SUGGEST THAT THIS WILL BE
THE CASE INTO THE EVENING HOURS. NWP GUIDANCE...ESPECIALLY THE NAM
AND RAP SUGGEST THAT A SHALLOW LAYER OF MOISTURE WILL SPREAD INTO
THE WESTERN PIEDMONT OVERNIGHT AND WILL LIKELY RESULT IN SOME
STRATUS OVERNIGHT. IN FACT...A FEW OF THE SREF MEMBERS ACTUALLY SPIT
OUT A LITTLE PRECIP AT KGSO AND KROA. WILL KEEP THE FORECAST DRY AND
INCLUDE PARTLY CLOUDY SKIES IN THE TRIAD REGION OVERNIGHT. BOUNDARY
LAYER PROFILERS AT BOTH CLAYTON AND RESEARCH TRIANGLE PARK THIS
AFTERNOON NOTE THE STRONGER NORTHEAST FLOW BETWEEN 2-4KFT EARLIER
TODAY HAS WEAKENED SOMEWHAT DURING THE PAST FEW HOURS AND THIS
SHOULD ALLOW THE WIND GUSTS TO RELAX DURING THE NEXT FEW HOURS.
WHILE GUSTS WILL LINGER LONGER TO THE EAST IN THE COASTAL PLAIN MOST
LOCATIONS WILL SEE A LIGHT NORTHEAST WIND OVERNIGHT WHICH WILL
MITIGATE FOG DEVELOPMENT. MINIMUM TEMPERATURE GUIDANCE FOR TONIGHT
HAS GENERALLY TRENDED DOWNWARD DURING THE PAST DAY OR TWO. WILL
FORECAST LOWS IN THE UPPER 40S IN THE NE PIEDMONT AND N COASTAL
PLAIN WITH LOWS IN THE LOWER 50S ELSEWHERE INCLUDING THE TRIAD WHERE
CLOUDS AND A STIRRING WIND KEEPS TEMPERATURES ELEVATED. -BLAES
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 245 PM SUNDAY...
FAIR WEATHER WITH SLIGHTLY BELOW SEASONABLE TEMPERATURES IS EXPECTED
FOR MONDAY AND MONDAY NIGHT. HIGH PRESSURE CENTERED OVER THE EASTERN
GREAT LAKES WILL GRADUALLY SHIFT SOUTHEAST AND RIDGE INTO THE
CAROLINAS AND VIRGINIA AS A SHORT WAVE RIDGE OF HIGH PRESSURE BUILDS
EAST. SOME RESIDUAL LOW LEVEL MOISTURE WILL RESULT IN A FEW CUMULUS
CLOUDS DURING THE AFTERNOON ACROSS THE REGION AND SOME PATCHY
STRATUS ACROSS THE WESTERN PIEDMONT ON MONDAY NIGHT. HIGHS MONDAY
WILL RANGE IN THE 71-78 RANGE...COOLEST IN THE NORTHEAST. CHILLY
LOWS IN THE 47-54 RANGE ARE EXPECTED TUESDAY MORNING. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SUNDAY...
AS OF 235 PM SUNDAY...
A FAIRLY DRY PERIOD IS EXPECTED FOR MOST OF THE LONG TERM WITH THE
EXCEPTION BEING SOME LIGHT STRATIFORM RAIN ASSOCIATED WITH A
SHORTWAVE LOW COMING OUT OF THE GULF OF MEXICO AND TRACKING ACROSS
THE DEEP SOUTH. SEASONAL MAXIMUM TEMPERATURES FROM THE MID 70S TO
NEAR 80S ARE EXPECTED FOR THE DURATION OF THE LONG TERM. LOWS WILL
GENERALLY RANGE FROM THE LOW TO UPPER 50S...NEAR OR SLIGHTLY BELOW
NORMAL FOR THIS TIME OF YEAR.
FOR TUESDAY...SURFACE HIGH WILL EXTEND INTO THE CAROLINAS FROM
SOUTHERN CANADA WITH A VERY SHARP UPPER LEVEL RIDGE ACROSS THE AREA.
EXPECT CLOUD COVER TO INCREASE LATE IN THE DAY FROM SOUTHWEST TO
NORTHEAST AS MOISTURE BEGINS TO BE ADVECTED NORTHWARD AHEAD OF THE
LOW.
ON WEDNESDAY AND THURSDAY THE LOW TO THE SOUTHWEST WILL BEGIN TO
DEEPEN WITH THE GFS COMING INTO BETTER AGREEMENT WITH THE ECMWF AND
BOTH MODELS NOW OPENING UP THE GULF OF MEXICO TO NORTHWARD MOISTURE
TRANSPORT. THE TIMING IS STILL A BIT OFF WITH THE ECMWF MORE
AGGRESSIVELY DEEPENING THE LOW AND MORE PROGRESSIVE WITH THE TIMING.
WILL STILL MORE CLOSELY FOLLOW THE ECMWF AND FORECASTED POPS AND
CLOUD COVER WILL ILLUSTRATE THIS...BRINGING CHANCE POPS INTO THE
SOUTH AND WEST ON WEDNESDAY AFTERNOON THROUGH TUESDAY MORNING. WILL
LEAVE SOME ROOM FOR THE POSSIBILITY OF THE GFS SOLUTION AND KEEP
SLIGHT CHANCE POPS THROUGH THURSDAY AFTERNOON. EXPECT RAIN TO BE
LIGHT AND STRATIFORM IN NATURE ALTHOUGH GFS FORECAST SOUNDINGS DO
HINT AT AN ELEVATED MIXED LAYER ABOVE A VERY STRONG CAP AT 950 MB.
ONE DIFFERENCE MAKER COULD BE A MUCH SMALLER SHORTWAVE IMPULSE IN
THE NORTHERN STREAM TRACKING THROUGH THE OHIO VALLEY. SLOWER GFS
TIMING ALLOWS THIS FEATURE TO INTERACT MORE WITH MOISTURE FROM THE
SOUTHERN STREAM AND TRACK ACROSS SOUTHERN VA. FOR NOW...WILL LEAVE
THE DETAILS OF THIS TO THE DAYS AHEAD.
AFTER THE LOW EXITS OFF OF THE COAST ON THURSDAY NIGHT...THINGS WILL
DRY OUT CONSIDERABLY FOR THE REST OF THE LONG TERM. A STRONG UPPER
LEVEL RIDGE WILL DOMINATE THE EASTERN CONUS ALONG WITH SURFACE HIGH
PRESSURE EXTENDING DOWN THE EAST COAST.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 200 PM SUNDAY...
LATEST OBSERVATIONS SHOW FAIRLY WIDESPREAD STRATUS WITH MVFR/VFR
CEILINGS ACROSS THE COASTAL PLAIN SITES (KFAY AND KRWI) WITH SCT-BKN
VFR STRATOCUMULUS ELSEWHERE. MODEL GUIDANCE SUGGESTS THE LOW STRATUS
IN THE EAST WILL GRADUALLY THIN THIS EVENING RESULTING IN VFR
CONDITIONS IN SCT STRATUS OVERNIGHT. FURTHER WEST...RESIDUAL CLOUDS
ENHANCED BY DAYTIME HEATING WILL THIN INITIALLY THIS EVENING WITH
SOME OF THE GUIDANCE IS DEPICTING ANOTHER AREA OF STRATUS DEVELOPING
AND MOVING INTO THE TRIAD TAF SITES (KINT AND KGSO) OVERNIGHT WITH
VFR CEILINGS. VFR CONDITIONS ARE EXPECTED TO DOMINATE ON MONDAY WITH
PERIODS OF SCT CUMULUS AT AROUND 4-5KFT. NORTHEAST WINDS AT 10-15
KTS WITH GUSTS AT TIMES EXCEEDING 22KTS THIS AFTERNOON WILL BECOME
LESS GUSTY TONIGHT BUT REMAIN BLOWING AT 5-10KTS OVERNIGHT. AS A
HIGH PRESSURE RIDGE BUILDS INTO THE REGION...WINDS WILL RELAX ON
MONDAY AFTERNOON AND BECOME NORTHEAST TO EASTERLY.
LOOKING BEYOND 18Z MONDAY... VFR CONDITIONS WILL PERSIST ON MONDAY
THROUGH EARLY WEDNESDAY ALTHOUGH SOME STRATUS WITH VFR CEILINGS MAY
DEVELOP MONDAY NIGHT AND TUESDAY NIGHT IN THE WESTERN PIEDMONT. THE
NEXT STORM SYSTEM WILL APPROACH THE REGION FROM THE SOUTHWEST ON
WEDNESDAY INTO THURSDAY WITH A CHANCE OF ADVERSE AVIATION
CONDITIONS...ESPECIALLY ACROSS THE SOUTH. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...ELLIS
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
247 PM EDT SUN SEP 22 2013
.SYNOPSIS...
THE COLD FRONT THAT MOVED THROUGH THE REGION EARLY THIS MORNING HAS
MOVED. HIGH PRESSURE WILL BUILD INTO THE REGION AND PERSIST THROUGH
LATE TUESDAY. THE NEXT STORM SYSTEM WILL APPROACH THE AREA ON
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 245 PM SUNDAY...
LATEST SURFACE ANALYSIS SHOWS A COLD FRONT AND A WEAK AREA OF LOW
PRESSURE MOVING AWAY FROM THE NC COAST WITH AN AREA OF HIGH PRESSURE
CENTERED OVER THE WESTERN GREAT LAKES. DEEP LAYER MOISTURE LOCATED
OVER THE COASTAL REGION GRADUALLY THINS ACROSS THE COASTAL PLAIN AND
ESPECIALLY THE EASTERN PIEDMONT. A 1708Z AMADAR AIRCRAFT SOUNDING AT
KRDU SHOWS A VERY SHALLOW LAYER OF MOISTURE TRAPPED BELOW THE
INVERSION. VISIBLE SATELLITE IMAGERY SUGGESTS THAT THE
STRATO-CUMULUS ACROSS THE WESTERN PERIPHERY OF THE MAIN CLOUD SHIELD
AND ACROSS THE NORTHERN PIEDMONT IS BEGINNING TO WANE AS THE
MOISTURE BEGINS TO MIX OUT. NWP GUIDANCE SUGGEST THAT THIS WILL BE
THE CASE INTO THE EVENING HOURS. NWP GUIDANCE...ESPECIALLY THE NAM
AND RAP SUGGEST THAT A SHALLOW LAYER OF MOISTURE WILL SPREAD INTO
THE WESTERN PIEDMONT OVERNIGHT AND WILL LIKELY RESULT IN SOME
STRATUS OVERNIGHT. IN FACT...A FEW OF THE SREF MEMBERS ACTUALLY SPIT
OUT A LITTLE PRECIP AT KGSO AND KROA. WILL KEEP THE FORECAST DRY AND
INCLUDE PARTLY CLOUDY SKIES IN THE TRIAD REGION OVERNIGHT. BOUNDARY
LAYER PROFILERS AT BOTH CLAYTON AND RESEARCH TRIANGLE PARK THIS
AFTERNOON NOTE THE STRONGER NORTHEAST FLOW BETWEEN 2-4KFT EARLIER
TODAY HAS WEAKENED SOMEWHAT DURING THE PAST FEW HOURS AND THIS
SHOULD ALLOW THE WIND GUSTS TO RELAX DURING THE NEXT FEW HOURS.
WHILE GUSTS WILL LINGER LONGER TO THE EAST IN THE COASTAL PLAIN MOST
LOCATIONS WILL SEE A LIGHT NORTHEAST WIND OVERNIGHT WHICH WILL
MITIGATE FOG DEVELOPMENT. MINIMUM TEMPERATURE GUIDANCE FOR TONIGHT
HAS GENERALLY TRENDED DOWNWARD DURING THE PAST DAY OR TWO. WILL
FORECAST LOWS IN THE UPPER 40S IN THE NE PIEDMONT AND N COASTAL
PLAIN WITH LOWS IN THE LOWER 50S ELSEWHERE INCLUDING THE TRIAD WHERE
CLOUDS AND A STIRRING WIND KEEPS TEMPERATURES ELEVATED. -BLAES
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 245 PM SUNDAY...
FAIR WEATHER WITH SLIGHTLY BELOW SEASONABLE TEMPERATURES IS EXPECTED
FOR MONDAY AND MONDAY NIGHT. HIGH PRESSURE CENTERED OVER THE EASTERN
GREAT LAKES WILL GRADUALLY SHIFT SOUTHEAST AND RIDGE INTO THE
CAROLINAS AND VIRGINIA AS A SHORT WAVE RIDGE OF HIGH PRESSURE BUILDS
EAST. SOME RESIDUAL LOW LEVEL MOISTURE WILL RESULT IN A FEW CUMULUS
CLOUDS DURING THE AFTERNOON ACROSS THE REGION AND SOME PATCHY
STRATUS ACROSS THE WESTERN PIEDMONT ON MONDAY NIGHT. HIGHS MONDAY
WILL RANGE IN THE 71-78 RANGE...COOLEST IN THE NORTHEAST. CHILLY
LOWS IN THE 47-54 RANGE ARE EXPECTED TUESDAY MORNING. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 235 PM SUNDAY...
A FAIRLY DRY PERIOD IS EXPECTED FOR MOST OF THE LONG TERM WITH THE
EXCEPTION BEING SOME LIGHT STRATIFORM RAIN ASSOCIATED WITH A
SHORTWAVE LOW COMING OUT OF THE GULF OF MEXICO AND TRACKING ACROSS
THE DEEP SOUTH. SEASONAL MAXIMUM TEMPERATURES FROM THE MID 70S TO
NEAR 80S ARE EXPECTED FOR THE DURATION OF THE LONG TERM. LOWS WILL
GENERALLY RANGE FROM THE LOW TO UPPER 50S...NEAR OR SLIGHTLY BELOW
NORMAL FOR THIS TIME OF YEAR.
FOR TUESDAY...SURFACE HIGH WILL EXTEND INTO THE CAROLINAS FROM
SOUTHERN CANADA WITH A VERY SHARP UPPER LEVEL RIDGE ACROSS THE AREA.
EXPECT CLOUD COVER TO INCREASE LATE IN THE DAY FROM SOUTHWEST TO
NORTHEAST AS MOISTURE BEGINS TO BE ADVECTED NORTHWARD AHEAD OF THE
LOW.
ON WEDNESDAY AND THURSDAY THE LOW TO THE SOUTHWEST WILL BEGIN TO
DEEPEN WITH THE GFS COMING INTO BETTER AGREEMENT WITH THE ECMWF AND
BOTH MODELS NOW OPENING UP THE GULF OF MEXICO TO NORTHWARD MOISTURE
TRANSPORT. THE TIMING IS STILL A BIT OFF WITH THE ECMWF MORE
AGGRESSIVELY DEEPENING THE LOW AND MORE PROGRESSIVE WITH THE TIMING.
WILL STILL MORE CLOSELY FOLLOW THE ECMWF AND FORECASTED POPS AND
CLOUD COVER WILL ILLUSTRATE THIS...BRINGING CHANCE POPS INTO THE
SOUTH AND WEST ON WEDNESDAY AFTERNOON THROUGH TUESDAY MORNING. WILL
LEAVE SOME ROOM FOR THE POSSIBILITY OF THE GFS SOLUTION AND KEEP
SLIGHT CHANCE POPS THROUGH THURSDAY AFTERNOON. EXPECT RAIN TO BE
LIGHT AND STRATIFORM IN NATURE ALTHOUGH GFS FORECAST SOUNDINGS DO
HINT AT AN ELEVATED MIXED LAYER ABOVE A VERY STRONG CAP AT 950 MB.
ONE DIFFERENCE MAKER COULD BE A MUCH SMALLER SHORTWAVE IMPULSE IN
THE NORTHERN STREAM TRACKING THROUGH THE OHIO VALLEY. SLOWER GFS
TIMING ALLOWS THIS FEATURE TO INTERACT MORE WITH MOISTURE FROM THE
SOUTHERN STREAM AND TRACK ACROSS SOUTHERN VA. FOR NOW...WILL LEAVE
THE DETAILS OF THIS TO THE DAYS AHEAD.
AFTER THE LOW EXITS OFF OF THE COAST ON THURSDAY NIGHT...THINGS WILL
DRY OUT CONSIDERABLY FOR THE REST OF THE LONG TERM. A STRONG UPPER
LEVEL RIDGE WILL DOMINATE THE EASTERN CONUS ALONG WITH SURFACE HIGH
PRESSURE EXTENDING DOWN THE EAST COAST.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AS OF 200 PM SUNDAY...
LATEST OBSERVATIONS SHOW FAIRLY WIDESPREAD STRATUS WITH MVFR/VFR
CEILINGS ACROSS THE COASTAL PLAIN SITES (KFAY AND KRWI) WITH SCT-BKN
VFR STRATOCUMULUS ELSEWHERE. MODEL GUIDANCE SUGGESTS THE LOW STRATUS
IN THE EAST WILL GRADUALLY THIN THIS EVENING RESULTING IN VFR
CONDITIONS IN SCT STRATUS OVERNIGHT. FURTHER WEST...RESIDUAL CLOUDS
ENHANCED BY DAYTIME HEATING WILL THIN INITIALLY THIS EVENING WITH
SOME OF THE GUIDANCE IS DEPICTING ANOTHER AREA OF STRATUS DEVELOPING
AND MOVING INTO THE TRIAD TAF SITES (KINT AND KGSO) OVERNIGHT WITH
VFR CEILINGS. VFR CONDITIONS ARE EXPECTED TO DOMINATE ON MONDAY WITH
PERIODS OF SCT CUMULUS AT AROUND 4-5KFT. NORTHEAST WINDS AT 10-15
KTS WITH GUSTS AT TIMES EXCEEDING 22KTS THIS AFTERNOON WILL BECOME
LESS GUSTY TONIGHT BUT REMAIN BLOWING AT 5-10KTS OVERNIGHT. AS A
HIGH PRESSURE RIDGE BUILDS INTO THE REGION...WINDS WILL RELAX ON
MONDAY AFTERNOON AND BECOME NORTHEAST TO EASTERLY.
LOOKING BEYOND 18Z MONDAY... VFR CONDITIONS WILL PERSIST ON MONDAY
THROUGH EARLY WEDNESDAY ALTHOUGH SOME STRATUS WITH VFR CEILINGS MAY
DEVELOP MONDAY NIGHT AND TUESDAY NIGHT IN THE WESTERN PIEDMONT. THE
NEXT STORM SYSTEM WILL APPROACH THE REGION FROM THE SOUTHWEST ON
WEDNESDAY INTO THURSDAY WITH A CHANCE OF ADVERSE AVIATION
CONDITIONS...ESPECIALLY ACROSS THE SOUTH. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...RE
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1236 PM CDT SUN SEP 22 2013
.UPDATE...
ISSUED AT 1236 PM CDT SUN SEP 22 2013
UPDATED TO ADD AVIATION SECTION BELOW.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MAIN CHALLENGES WILL BE TEMPERATURES TODAY AND PRECIP CHANCES
TONIGHT INTO MONDAY. 00Z MODELS ARE IN DECENT AGREEMENT THROUGH
THIS PERIOD AND WILL USE A BLEND FOR DETAILS. 500MB LOW WILL
PROPAGATE FROM THE SOUTHWEST CONUS INTO THE CENTRAL PLAINS. THIS
WILL DEVELOP SOUTHWEST FLOW ALOFT BY TONIGHT...CONTINUING INTO
MONDAY. ALTHOUGH LOW LEVEL FLOW WILL SIGNIFICANTLY INCREASE...IT
WILL BE FROM MORE OF A SOUTHEAST DIRECTION...PROMOTING THE VERY
DRY LOW LEVEL AIRMASS. THIS WILL BE A HINDRANCE ON PRECIP
POTENTIAL. FOR TONIGHT...MODELS INDICATE A STRONG 850MB JET 40-50
KNOTS...WITH WEAK INSTABILITY QUICKLY ADVECTING NORTHWARD ALONG
THE WESTERN EDGE OF THIS FEATURE. COULD BE AN ISOLATED STORM
(ACROSS THE FAR WESTERN FA)...BUT INSTABILITY SEEMS TO BE IN AN
UNFAVORABLE AREA. FOR MONDAY...HIGHER MOISTURE AND LOW LEVEL
CONVERGENCE REMAINS WEST OF THE REGION...WITH AREAS ACROSS
WESTERN AND CENTRAL NORTH DAKOTA (POSSIBLY PORTIONS OF THE DEVILS
LAKE BASIN) MOST LIKELY TO EXPERIENCE SHOWERS.
MAX TEMPS TODAY SHOULD RANGE FROM THE UPPER 60S INTO THE UPPER
70S. THE 06Z RAP IS SHOWING A STRONG WARM FRONT MOVING INTO THE
SW FA...WITH TEMPS INTO THE UPPER 80S. MOST MODELS SHOW THIS
FEATURE...BUT NOT QUITE AS FAR NORTH BY 00Z MONDAY. WILL HAVE TO
MONITOR...FOR NOW STUCK WITH LOW TO MID 80S FOR THIS AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 AM CDT SUN SEP 22 2013
MONDAY NIGHT-TUESDAY NIGHT...THE LOW LEVEL CONVERGENCE SHIFTS
EASTWARD AND THROUGH THE FA. THE LOW LEVEL AIRMASS SHOULD REMAIN
DRY AS THE MAJORITY OF MODELS SHOW THE MAIN UPPER LOW WILL BE WELL
SOUTH OF THE REGION. ANTICIPATE A BAND OF SHOWERS THAT WILL WEAKEN
AS IT MOVES EAST AND FINALLY DIES BY TUESDAY AFTERNOON.
TEMPERATURES WILL DEPEND ON CLOUD COVER...BUT GENERALLY SLIGHTLY
ABOVE NORMAL VALUES.
WEDNESDAY-SATURDAY...500MB SOUTHWEST FLOW ALOFT WILL CONTINUE TO
ALLOW ABOVE NORMAL TEMPERATURES INTO THE NORTHERN PLAINS THRU THE
END OF THE WEEK. TIMING AND PLACEMENT OF SHORT WAVE ENERGY TO
TRACK FROM THE ROCKIES ACROSS THE DAKOTAS STILL UNCERTAIN...
THOUGH BEST CHANCES FOR MEASURABLE RAINFALL WILL BE WITH FROPA ON
FRIDAY. POPS IN THE FORECAST FOR WED AND THURS ARE LESS CERTAIN
ESPECIALLY FROM RED RIVER VALLEY AND EASTWARD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1236 PM CDT SUN SEP 22 2013
TIGHT PRESSURE GRADIENT IN ADIABATIC LAYER NEAR THE SFC WILL RESULT
IN GUSTY SOUTH-SOUTHEAST WINDS TODAY AND TONIGHT. EXPECT SOME LIGHT
TURBULENCE IN THE BOUNDARY LAYER WITH A BIT OF DIRECTIONAL AND SPEED
SHEAR. WINDS WILL WEAKEN A BIT AFTER SUNSET BUT WILL INCREASE AGAIN
WITH INVERSION BREAK NEAR END OF PERIOD. SKIES INITIALLY CLEAR BUT
EXPECT CIRRUS SHIELD TO MOVE INTO THE REGION THIS AFTERNOON AND
OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...GODON
SHORT TERM...TG
LONG TERM...TG/JK
AVIATION...HOPKINS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
617 PM EDT SUN SEP 22 2013
.SYNOPSIS...
COOL CANADIAN HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES
THROUGH MONDAY. THIS HIGH WILL REMAIN IN THE GREAT LAKES VICINITY
THROUGH MOST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE GREAT LAKES REGION REMAINS BETWEEN AN UPPER LEVEL TROUGH OVER
QUEBEC AND A RIDGE BUILDING OVER THE UPPER MIDWEST. ENOUGH
TROUGHINESS REMAINS ALONG WITH THE 850MB COLD POOL(TEMPS DOWN TO -2C
OVER ONTARIO) TO MAINTAIN CONSIDERABLE CLOUD COVER ACROSS THE
SOUTHERN ONTARIO AND QUEBEC THIS AFTERNOON. CLOUDS ALSO EXTEND
DOWNWIND OFF ALL OF THE GREAT LAKES...EVEN NEARLY OVERCAST SKIES
OVER LAKE MICHIGAN DIRECTLY BENEATH THE SURFACE HIGH. AS NOTED
EARLY...NAM SOUNDINGS ARE ALREADY RUNNING A LITTLE TOO OPTIMISTIC
WITH CLEARING WHILE RUC SOUNDINGS KEEP EASTERN AREAS CLOUDY ALL
NIGHT BENEATH THE LOWERING INVERSION. HRRR IS SIMILAR. WILL CARRY
A MOSTLY CLEAR FORECAST TOWARDS FINDLAY WITH MOSTLY CLOUDY SKIES
FOR MOST OF THE NIGHT ACROSS THE EASTERN HALF OF THE AREA. CAN
ALREADY SEE CLOUDS RETURNING WEST OF CLEVELAND WITH LITTLE MESO
LOW COMING ASHORE NEAR LAKE COUNTY. MOS GUIDANCE ALSO TOO QUICK
WITH THE CLEARING TREND SO WILL GO 2-5 DEGREES WARMER TONIGHT FOR
AREAS EAST OF A CLE-CAK LINE. TEMPERATURES WILL FALL QUICKLY WITH
ANY SIZABLE BREAKS IN THE CLOUDS. HAVE ADDED A FEW SHOWERS TO
LAKE/ASHTABULA/GEAUGA COUNTIES WITH THE MESO LOW. A FEW RADAR
RETURNS MIGHT ACTUALLY ACCUMULATE 0.01 INCHES EARLY THIS EVENING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
A DRY STRETCH OF WEATHER WITH COOL NIGHTS TO FOLLOW DURING THE SHORT
TERM. HIGH PRESSURE WILL REMAIN OVER THE EASTERN GREAT LAKES THROUGH
TUESDAY...SHIFTING SLIGHTLY TO THE NORTH ON WEDNESDAY. DIURNAL CU
EXPECTED ONCE AGAIN ON MONDAY BEFORE WE FINALLY MIX OUT OUR MOISTURE
AND CLEAR FOR MONDAY NIGHT. THIS WILL SET UP FOR A CHILLY NIGHT ON
MONDAY WITH MOST INLAND AREAS DIPPING TO NEAR 40 DEGREES. SOME OF
THE COOLER SPOTS IN NE OHIO WILL DIP INTO THE UPPER 30S WITH MID 30S
FOR INTERIOR NW PA. HAVE INCLUDED AREAS OF FROST FOR THOSE COOLEST
SPOTS AND THERE IS POTENTIAL THAT WE MAY NEED A FROST ADVISORY FOR
ERIE AND CRAWFORD PA. A HEALTHY DIURNAL SPREAD WILL ALLOW HIGHS TO
RECOVER INTO THE LOW AND MID 60S FOR TUESDAY...THEN COOL BACK INTO
THE 40S FOR TUESDAY NIGHT. LEANED THE FORECAST TOWARDS THE RAW MODEL
TEMPERATURES WHICH ARE SLIGHTLY COOLER THAN MOS GUIDANCE THROUGH THE
SHORT TERM.
UPPER LEVEL LOW OVER THE GREAT BASIN WILL MOVE NORTHEAST ACROSS THE
PLAINS ON MONDAY AND ENCOUNTER SOME RESISTANCE BY THE HIGH AMPLITUDE
UPPER LEVEL RIDGE OVER THE GREAT LAKES REGION. THE UPPER LOW WILL
WEAKEN AS IT SLIDES EAST ACROSS THE OHIO VALLEY ON TUESDAY NIGHT AND
WEDNESDAY. MODELS KEEP THE QPF SOUTH OF THE FORECAST AREA AND GIVEN
THE RESIDENT DRY AIRMASS IN PLACE...WILL KEEP THE FORECAST DRY WITH
JUST SOME INCREASE IN CLOUDS ON WEDNESDAY. TEMPS WILL RETURN TO NEAR
70 MOST AREAS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A RIDGE OF HIGH PRESSURE WILL BE OVER THE AREA TO START THE FORECAST
PERIOD AND THEN IT WILL SHIFT SLOWLY EAST AS A WEAKENING COLD FRONT
ADVANCES TOWARDS THE REGION. SOME QUESTION AS TO THE TIMING OF THE
FRONT FOR LATE IN THE WEEKEND. THE 12Z GFS IS MUCH QUICKER THAN THE
ECMWF AND THE CANADIAN MODEL. AT THIS TIME LEANING MORE TOWARD THE
SLOWER MODELS. SO THE MAIN CHANCE OF PRECIPITATION WILL BE ON SUNDAY
INTO SUNDAY NIGHT. IT SEEMS STABLE SO ONLY FORECASTING SHOWERS. USED
A BLEND OF GUIDANCE FOR THE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BUILDING IN AT THE SURFACE. THE LAKE AND 850 MB
TEMPERATURE DIFFERENCE IS NEAR 19C AND WILL SLOWLY WARM OVERNIGHT.
THE CLOUDS ARE THICKENING WITH SOME AFTERNOON SUN. THE BIG DILEMMA
IS HOW MUCH WILL THE CLOUDS DECREASE OVERNIGHT. WILL DECREASE THE
CLOUDS TO SCATTERED OVER NW OH AND AT INLAND LOCATIONS. TOO DRY
FOR FOG AT THE TAF SITES. ANY CLOUDS AT SUNRISE MONDAY WILL SLOWLY
DECREASE AS THE SUBSIDENCE AND DRIER AIR CONTINUE TO WORK IN.
OUTLOOK...MAINLY VFR.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE WILL BE BUILDING IN TONIGHT. WILL LET THE
SMALL CRAFT ADVISORY AND RIP CURRENT RISK EXPIRE/CANCEL AS THE WINDS
AND WAVES ARE DECREASING. HOWEVER AS THE RIDGE IS BUILDING IN
TONIGHT THE NORTHEAST FLOW GRADIENT WILL INCREASE AND THAT COULD
CAUSE THE WAVES TO GET CLOSE TO SMALL CRAFT ADVISORY CRITERIA AND
AGAIN ON MONDAY. HOWEVER...AT THIS TIME IT SEEMS THAT 2 TO 4 FOOT
WAVES SHOULD HANDLE IT. AS THE RIDGE BECOMES STRONGER MONDAY NIGHT
AND TUESDAY THE WINDS WILL BE LIGHTER...THUS DECREASING THE WAVES.
THE RIDGE WILL BE AROUND THE LAKE THROUGH FRIDAY AND THAT WILL MEAN
AN EAST OR NORTHEAST FLOW. AT THIS TIME A SMALL CRAFT ADVISORY IS
NOT EXPECTED AS THE NORTHEAST FLOW SHOULD NOT BE STRONG ENOUGH TO
CAUSE 3 TO 5 FOOT WAVES BUT THIS WILL HAVE TO BE WATCHED AS
NORTHEAST FLOWS ARE NOTORIOUS FOR CAUSING HIGH WAVES ESPECIALLY ON
THE WEST END OF THE LAKE BECAUSE OF THE LONG FETCH.
A COLD FRONT WILL BE APPROACHING THE LAKE FOR LATE IN THE UPCOMING
WEEKEND SHIFTING THE WINDS TO SOUTHERLY.
&&
.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
404 PM EDT SUN SEP 22 2013
.SYNOPSIS...
COOL CANADIAN HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES
THROUGH MONDAY. THIS HIGH WILL REMAIN IN THE GREAT LAKES VICINITY
THROUGH MOST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE GREAT LAKES REGION REMAINS BETWEEN AN UPPER LEVEL TROUGH OVER
QUEBEC AND A RIDGE BUILDING OVER THE UPPER MIDWEST. ENOUGH
TROUGHINESS REMAINS ALONG WITH THE 850MB COLD POOL(TEMPS DOWN TO -2C
OVER ONTARIO) TO MAINTAIN CONSIDERABLE CLOUD COVER ACROSS THE
SOUTHERN ONTARIO AND QUEBEC THIS AFTERNOON. CLOUDS ALSO EXTEND
DOWNWIND OFF ALL OF THE GREAT LAKES...EVEN NEARLY OVERCAST SKIES
OVER LAKE MICHIGAN DIRECTLY BENEATH THE SURFACE HIGH. AS NOTED
EARLY...NAM SOUNDINGS ARE ALREADY RUNNING A LITTLE TOO OPTIMISTIC
WITH CLEARING WHILE RUC SOUNDINGS KEEP EASTERN AREAS CLOUDY ALL
NIGHT BENEATH THE LOWERING INVERSION. WILL CARRY A MOSTLY CLEAR
FORECAST TOWARDS FINDLAY WITH MOSTLY CLOUDY SKIES FOR MOST OF THE
NIGHT ACROSS THE EASTERN HALF OF THE AREA. MOS GUIDANCE ALSO TOO
QUICK WITH THE CLEARING TREND SO WILL GO 2-5 DEGREES WARMER TONIGHT
FOR AREAS EAST OF A CLE-CAK LINE. TEMPERATURES WILL FALL QUICKLY
WITH ANY SIZABLE BREAKS IN THE CLOUDS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
A DRY STRETCH OF WEATHER WITH COOL NIGHTS TO FOLLOW DURING THE SHORT
TERM. HIGH PRESSURE WILL REMAIN OVER THE EASTERN GREAT LAKES THROUGH
TUESDAY...SHIFTING SLIGHTLY TO THE NORTH ON WEDNESDAY. DIURNAL CU
EXPECTED ONCE AGAIN ON MONDAY BEFORE WE FINALLY MIX OUT OUR MOISTURE
AND CLEAR FOR MONDAY NIGHT. THIS WILL SET UP FOR A CHILLY NIGHT ON
MONDAY WITH MOST INLAND AREAS DIPPING TO NEAR 40 DEGREES. SOME OF
THE COOLER SPOTS IN NE OHIO WILL DIP INTO THE UPPER 30S WITH MID 30S
FOR INTERIOR NW PA. HAVE INCLUDED AREAS OF FROST FOR THOSE COOLEST
SPOTS AND THERE IS POTENTIAL THAT WE MAY NEED A FROST ADVISORY FOR
ERIE AND CRAWFORD PA. A HEALTHY DIURNAL SPREAD WILL ALLOW HIGHS TO
RECOVER INTO THE LOW AND MID 60S FOR TUESDAY...THEN COOL BACK INTO
THE 40S FOR TUESDAY NIGHT. LEANED THE FORECAST TOWARDS THE RAW MODEL
TEMPERATURES WHICH ARE SLIGHTLY COOLER THAN MOS GUIDANCE THROUGH THE
SHORT TERM.
UPPER LEVEL LOW OVER THE GREAT BASIN WILL MOVE NORTHEAST ACROSS THE
PLAINS ON MONDAY AND ENCOUNTER SOME RESISTANCE BY THE HIGH AMPLITUDE
UPPER LEVEL RIDGE OVER THE GREAT LAKES REGION. THE UPPER LOW WILL
WEAKEN AS IT SLIDES EAST ACROSS THE OHIO VALLEY ON TUESDAY NIGHT AND
WEDNESDAY. MODELS KEEP THE QPF SOUTH OF THE FORECAST AREA AND GIVEN
THE RESIDENT DRY AIRMASS IN PLACE...WILL KEEP THE FORECAST DRY WITH
JUST SOME INCREASE IN CLOUDS ON WEDNESDAY. TEMPS WILL RETURN TO NEAR
70 MOST AREAS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A RIDGE OF HIGH PRESSURE WILL BE OVER THE AREA TO START THE FORECAST
PERIOD AND THEN IT WILL SHIFT SLOWLY EAST AS A WEAKENING COLD FRONT
ADVANCES TOWARDS THE REGION. SOME QUESTION AS TO THE TIMING OF THE
FRONT FOR LATE IN THE WEEKEND. THE 12Z GFS IS MUCH QUICKER THAN THE
ECMWF AND THE CANADIAN MODEL. AT THIS TIME LEANING MORE TOWARD THE
SLOWER MODELS. SO THE MAIN CHANCE OF PRECIPITATION WILL BE ON SUNDAY
INTO SUNDAY NIGHT. IT SEEMS STABLE SO ONLY FORECASTING SHOWERS. USED
A BLEND OF GUIDANCE FOR THE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE IS BUILDING IN AT THE SURFACE. THE LAKE AND 850 MB
TEMPERATURE DIFFERENCE IS NEAR 19C AND WILL SLOWLY WARM OVERNIGHT.
THE CLOUDS ARE THICKENING WITH SOME AFTERNOON SUN. THE BIG DILEMMA
IS HOW MUCH WILL THE CLOUDS DECREASE OVERNIGHT. WILL DECREASE THE
CLOUDS TO SCATTERED OVER NW OH AND AT INLAND LOCATIONS. TOO DRY
FOR FOG AT THE TAF SITES. ANY CLOUDS AT SUNRISE MONDAY WILL SLOWLY
DECREASE AS THE SUBSIDENCE AND DRIER AIR CONTINUE TO WORK IN.
OUTLOOK...MAINLY VFR.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE WILL BE BUILDING IN TONIGHT. WILL LET THE
SMALL CRAFT ADVISORY AND RIP CURRENT RISK EXPIRE/CANCEL AS THE WINDS
AND WAVES ARE DECREASING. HOWEVER AS THE RIDGE IS BUILDING IN
TONIGHT THE NORTHEAST FLOW GRADIENT WILL INCREASE AND THAT COULD
CAUSE THE WAVES TO GET CLOSE TO SMALL CRAFT ADVISORY CRITERIA AND
AGAIN ON MONDAY. HOWEVER...AT THIS TIME IT SEEMS THAT 2 TO 4 FOOT
WAVES SHOULD HANDLE IT. AS THE RIDGE BECOMES STRONGER MONDAY NIGHT
AND TUESDAY THE WINDS WILL BE LIGHTER...THUS DECREASING THE WAVES.
THE RIDGE WILL BE AROUND THE LAKE THROUGH FRIDAY AND THAT WILL MEAN
AN EAST OR NORTHEAST FLOW. AT THIS TIME A SMALL CRAFT ADVISORY IS
NOT EXPECTED AS THE NORTHEAST FLOW SHOULD NOT BE STRONG ENOUGH TO
CAUSE 3 TO 5 FOOT WAVES BUT THIS WILL HAVE TO BE WATCHED AS
NORTHEAST FLOWS ARE NOTORIOUS FOR CAUSING HIGH WAVES ESPECIALLY ON
THE WEST END OF THE LAKE BECAUSE OF THE LONG FETCH.
A COLD FRONT WILL BE APPROACHING THE LAKE FOR LATE IN THE UPCOMING
WEEKEND SHIFTING THE WINDS TO SOUTHERLY.
&&
.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...UPDATED
NWS BROWNSVILLE TX
119 PM CDT SUN SEP 22 2013
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...THE NEARLY STATIONARY SURFACE LOW SPINNING OVER NW
GULF OF MEX WILL MAINTAIN A FAIRLY DRY AND STABLE NORTHERLY LOW
LEVEL FLOW ACROSS THE LOWER RGV AIRPORTS THROUGHOUT THE NEXT 24
HOURS. SOME LINGERING RESIDUAL MOISTURE WILL PRODUCE SOME FAIR
WX CU THIS AFTERNOON AND TOMORROW AFTERNOON. HOWEVER EXPECT VFR
CEILINGS AND VSBYS TO PREVAIL THROUGH THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT SUN SEP 22 2013/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...CEILINGS HAVE LIFTED TO AROUND 10KFT ACROSS THE
LOWER VALLEY. EXPECT THIS LAYER TO BREAK AND CLEAR OUT BY
THE EARLY MORNING HOURS WITH NORTHERLY WINDS INCREASING WITH
GUSTS UP 25 KNOTS POSSIBLE. THE LOW PRESSURE OVER THE GULF OF
MEXICO WILL CONTINUE TO SHIFT NORTHEAST WHICH WILL ALLOW FOR
WINDS TO DECOUPLE INTO THE EVENING. VFR CONDITIONS WILL PREVAIL
TONIGHT.
PREV DISCUSSION... /ISSUED 345 AM CDT SUN SEP 22 2013/
SHORT TERM /NOW THROUGH MONDAY/...UPPER LEVEL TROUGH MOVING
ACROSS NORTHERN CA INTO NEVADA WILL DEEPEN AND MIGRATE
EAST/SOUTHEAST INTO THE FOUR CORNERS REGION WHILE RIDGE BUILDS
OVER NORTH CENTRAL TEXAS. AN ELONGATED POSITIVE TILTED TROUGH OVER
THE TEXAS REGION WILL GRADUALLY SHIFT EASTWARD ADVECTING DRIER AIR
ACROSS SOUTH TEXAS FROM THE NORTH. SURFACE LOW OVER THE GULF
WATERS WILL STRENGTHEN THE GRADIENT ALONG THE RIO GRANDE VALLEY
AND KEEP A NORTH TO NORTHEAST FLOW ACROSS MUCH OF THE CWA TODAY.
WINDS WILL INCREASE BETWEEN 20 TO 25 MPH ESPECIALLY ALONG THE
COAST. AS DRIER AIR MOVES INTO S TEXAS...CLEAR SKIES WILL PREVAIL
ACROSS THE CWA WHILE AT THE COAST MOISTURE RAP AROUND THIS LOW
WILL INCREASE THE CLOUD COVER BETWEEN A FEW TO SCATTERED CLOUD
LAYER ALONG THE COAST. THE MOISTURE CONTENT WILL NOT BE VERY
SHALLOW WHICH WILL LIMIT CONVECTION TO DEVELOP. HIGH TEMPERATURES
TODAY WILL TREND 2 TO 3 DEG WARMER COMPARED TO YESTERDAYS
TEMPERATURES.
AS THIS LOW CONTINUES TO MOVE FURTHER FROM THE COAST OF TEXAS THIS
AFTERNOON..SFC GRADIENT WILL GRADUALLY RELAX AND REDUCE THE NORTH TO
NORTHEAST WINDS ACROSS THE AREA AND THE CHANCES OF RAIN LOWERS. A FEW
SHOWERS CAN NOT BE RULED OUT BUT WILL REMAIN OVER THE OFFSHORE WATERS
TODAY. TONIGHT...NORTHERLY FLOW WILL DIMINISH ACROSS THE CWA AN REMAIN
LIGHT AND VARIABLE DUE TO THE WEAKENING SURFACE GRADIENT. LOW TEMPS
WILL REMAIN WELL BELOW NORMAL...WITH THE WESTERN PORTION REACHING
THE MID TO UPPER 60S WHILE ALONG THE COAST REMAINING IN THE LOW 70S.
MONDAY...SURFACE LOW BEGINS TO MOVE PARALLEL TO THE TEXAS COAST INTO
THE NORTHWEST GULF WHILE DRIER AIR INDICATED BY THE NAM AND THE GFS
AT 1000 TO 500 MB RH LAYER MOVES INTO THE CWA FROM THE NORTHWEST. AS
THE DRY AIR INFILTRATES INTO THE CWA...THE CHANCE OR RAIN LOWERS
EVEN MORE TO LESS THAN 10 PERCENT ACROSS THE CWA. HIGH TEMPERATURES
WILL CONTINUE TO WARM INTO NEAR NORMAL TEMPERATURES FOR SEPTEMBER
WITH HIGHS NEAR THE MID 90S ALONG THE INTERNATIONAL BORDER. NORTH
WINDS WILL DECOUPLE QUICKLY AFTER SUNSET.
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...500MB TROUGH ACROSS
THE NORTH CENTRAL UNITED STATES MONDAY WILL SHIFT EASTWARD TUESDAY
AS A 500MB RIDGE BUILDS ACROSS THE SOUTHERN PLAINS. NORTHWEST FLOW
ALOFT WILL CONTINUE TO PROVIDE SUBSIDENCE ACROSS SOUTH TEXAS
TUESDAY INTO WEDNESDAY. LOW TO MID LEVEL MOISTURE IS EXPECTED TO
RETURN ACROSS THE RIO GRANDE VALLEY THURSDAY INTO FRIDAY AS A
500MB TROUGH DEVELOPS ACROSS THE WESTERN UNITED STATES AND THE
UPPER LEVEL RIDGE ACROSS TX SHIFTS EASTWARD. SURFACE LOW PRESSURE
IS PROGGED TO DEVELOP ACROSS THE CENTRAL PLAINS FRIDAY AHEAD OF
THE UPPER LEVEL TROUGH ACROSS THE WESTERN U.S. BRINGING A WEAK
COLD FRONT TOWARDS CENTRAL TX SATURDAY. THIS WILL PROVIDE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE WEEKEND AS MOISTURE
POOLS ALONG AND AHEAD OF THE FRONT AS THE FRONT MOVES INTO SOUTH
TX SATURDAY INTO SUNDAY.
MARINE...
NOW THROUGH MONDAY...MARINE CONDITIONS REMAIN DETERIORATED FOR
MUCH OF THE SHORT TERM FORECAST. LATEST OBSERVATION SHOWS SEAS
BUILDING NEAR 9 FEET OVER THE GULF WATERS DUE TO THE SURFACE LOW
PRESSURE OVER THE GULF OF MX. THIS LOW WILL STRENGTHEN THE
GRADIENT ALONG THE GULF WATERS AND INCREASE WINDS BETWEEN 20 TO 25
KNOTS AND GUSTS UP TO 30 KNOTS AT TIMES. SEAS WILL BUILD TODAY
INCREASING CLOSE TO 10 FEET THROUGH THE DAY. THE SEAS BEGIN TO
LOWER OVER THE NEAR SHORE WATERS AS THE CENTER OF THE LOW BEGINS
TO MOVE FURTHER EAST EARLY TONIGHT. HOWEVER...A NORTHEAST FETCH
WILL KEEP SEAS HIGHER THROUGH THE EVENING OVER THE GULF SO THE SCA
HAS BEEN EXTENDED FOR THE WHOLE MARINE AREA WITH THE EXCEPTION OF
THE LAGUNA MADRE. ON THE BAY...CONDITIONS WILL BE MARGINAL TO
SMALL CRAFT ADVISORY BUT IT WILL LIKELY BE FOR AN HOUR AND QUICKLY
LOWER THE WINDS. THE NORTHEAST WINDS OVER THE OFFSHORE WATERS WILL
CONTINUE TO KEEP SEAS HIGH AS THE LOW PRESSURE MOVES NORTHWARD SO
EXTENDED THE SCA FOR THE OFFSHORE THROUGH MIDNIGHT. THE SEAS WILL
GRADUALLY LOWER TO SCEC BY EARLY MORNING MONDAY AND IMPROVE UNTIL
THE END OF THE DAY MONDAY WITH SEAS BETWEEN 2 TO 4 FEET. AN
ISOLATED SHOWER WILL BE POSSIBLE BUT WILL NOT LAST LONG AND
PRODUCE BRIEF DOWNPOURS.
MONDAY NIGHT THROUGH THURSDAY...LIGHT TO MODERATE NORTH TO
NORTHEAST WINDS ACROSS THE COASTAL WATERS MON NIGHT WILL BACK TO
THE WEST ON TUESDAY AS THE LOW PRESSURE ACROSS THE WESTERN GULF OF
MEXICO MOVES NORTHWARD. LIGHT WEST TO NORTHWEST WINDS SHOULD
PREVAIL ACROSS THE WESTERN GULF WEDNESDAY BEFORE FINALLY SHIFTING
TO THE SOUTHEAST ON THURSDAY AS LOW PRESSURE MOVES INTO THE
NORTHERN PLAINS AND THE LOW PRESSURE ACROSS THE NORTHERN GULF OF
MEXICO WEAKENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 72 87 72 91 / 10 10 0 0
BROWNSVILLE 70 90 70 92 / 10 10 0 0
HARLINGEN 69 90 70 94 / 10 10 0 0
MCALLEN 68 92 71 96 / 10 10 0 0
RIO GRANDE CITY 68 92 68 96 / 10 10 0 0
SOUTH PADRE ISLAND 74 85 75 87 / 10 10 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 AM CDT MONDAY FOR GMZ170-175.
SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR GMZ150-155.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM...60
LONG TERM...55
GRAPHICAST/UPPER AIR...MARTINEZ
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 LA CROSSE WI
209 PM CDT SUN SEP 22 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 209 PM CDT SUN SEP 22 2013
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT SHORTWAVE TROUGH OVER UTAH AND ARIZONA...WHILE
RIDGING WAS STRENGTHENING DOWNSTREAM FROM TEXAS INTO MINNESOTA. THE
FORECAST AREA LIES ON THE EAST SIDE OF THE RIDGE...FAVORING
SUBSIDENCE...DRY CONDITIONS AND HIGH PRESSURE. 12Z GRB...DVN AND MPX
SOUNDINGS HAD PRECIPITABLE WATER VALUES OF 0.4-0.65 INCHES...
ANYWHERE FROM 50-100 PERCENT OF NORMAL. THE DRY AIR HAS ALLOWED FOR
SUNNY SKIES ACROSS THE AREA. TEMPERATURES VARY GREATLY ACROSS THE
FORECAST AREA...RESULTING FROM 12Z 925MB TEMPS RANGING FROM 4C AT
GRB TO 11C AT MPX AND DVN. READINGS RANGE FROM THE UPPER 50S AT
MEDFORD TO LOW 70S IN FAR WESTERN PORTIONS OF THE FORECAST AREA.
WINDS ARE INCREASING JUST OFF TO THE WEST OVER THE PLAINS AND
MINNESOTA...AHEAD OF LEE TROUGHING. WARMER AIR IS ACCOMPANYING THE
STRONGER WINDS WITH 925MB TEMPS AT 12Z OF 16C AT ABR AND 20C AT OAX.
SYNOPTIC OVERVIEW...
THE POTENT SHORTWAVE TROUGH IN THE SOUTHWESTERN U.S. IS PROGGED TO
LIFT UP INTO SOUTH DAKOTA AND NEBRASKA BY 00Z TUESDAY. THE APPROACH
OF THE TROUGH WILL HELP STRENGTHEN AND AMPLIFY THE RIDGE AS IT
PUSHES EAST INTO MICHIGAN BY 00Z.
DETAILS...
DRY CONDITIONS ARE GOING TO CONTINUE DESPITE AN INCREASE OF
SOUTHERLY WINDS OVER THE NEXT 24 HOURS. IN FACT...THERE ARE
INDICATIONS THAT PRECIPITABLE WATER VALUES WILL EVEN FALL AS DRY AIR
CENTERED OVER THE OZARKS AREA GETS ADVECTED NORTH ON THE SOUTH
WINDS. THE INCREASING PRESSURE GRADIENT AND SOUTH WINDS OVER THE
AREA TONIGHT WILL LIMIT BOTH TEMPERATURE FALL AND VALLEY FOG
POTENTIAL TONIGHT. COLDEST READINGS ARE EXPECTED TOWARDS CENTRAL
WISCONSIN WHERE GRADIENT IS LIGHTEST...WITH LOWS IN THE UPPER 30S.
MAYBE SOME VALLEY FOG CAN FORM IN THE WISCONSIN RIVER VALLEY BECAUSE
OF THE WIND BEING ORTHAGONAL TO THE VALLEY. COMBINATION OF DRIER
AIR...925MB TEMPS RANGING FROM 12C EAST TO 15C WEST AT 18Z
MONDAY...AND SOUTHERLY BREEZE SHOULD ALLOW TEMPERATURES TO CLIMB
INTO THE UPPER 60S TO LOW 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 209 PM CDT SUN SEP 22 2013
FIRST ITEM OF INTEREST IS THE SHORTWAVE TROUGH OVER SOUTH DAKOTA AND
NEBRASKA ON MONDAY. MODELS ARE IN GOOD AGREEMENT OF THE TROUGH
WEAKENING AS IT GETS LIFTED TOWARDS THE FORECAST AREA ON
TUESDAY...IN RESPONSE TO RUNNING INTO THE RIDGING AHEAD OF IT. WITH
THE TROUGH WEAKENING...THE 850MB MOISTURE TRANSPORT ACCOMPANYING IT
ALSO BEGINS TO FALL APART. HOW QUICK THE WEAKENING OF THE TROUGH AND
ASSOCIATED 850MB MOISTURE TRANSPORT OCCURS WILL DETERMINE WHETHER
ANY PRECIPITATION GETS INTO THE FORECAST AREA. THE 22.12Z GFS
CONTINUES TO SUGGEST THE TROUGH WILL STILL BE STRONG ENOUGH TO BRING
SOME SHOWERS TUESDAY AFTERNOON AND EVENING TO LOCATIONS WEST OF THE
MS RIVER. MEANWHILE THE 22.12Z NAM/CANADIAN/UKMET AND 22.00Z/12Z ECMWF
ARE ALL DRY DUE TO THEM WEAKENING THE TROUGH AND MOISTURE
TRANSPORT QUICKER. MODEL CONSENSUS WOULD POINT TO A DRY
FORECAST...BUT HONORED THE GFS AND PREVIOUS FORECAST WITH 20
PERCENT CHANCES WEST OF THE MS RIVER FOR TUESDAY AFTERNOON.
ANOTHER UPPER RIDGE IS FORECAST TO COME IN BEHIND THE TUESDAY TROUGH
BECAUSE OF A VERY DEEP TROUGH PROGGED TO FORM OVER THE WESTERN U.S.
ON WEDNESDAY. 500MB STANDARDIZED ANOMALIES OVER NEVADA AND
CALIFORNIA AT 00Z THU ARE 3 BELOW NORMAL. HEADING THROUGH THURSDAY
AND FRIDAY...THE TROUGH BEGINS TO LIFT OUT INTO THE NORTHERN
PLAINS...MOST LIKELY IN A POSITIVE TILT...CAUSING A HIGHLY AMPLIFIED
RIDGE TO DEVELOP OVER THE WESTERN GREAT LAKES REGION. SUBSIDENCE
WITH THIS RIDGE WILL KEEP THE FORECAST AREA DRY WEDNESDAY THROUGH
FRIDAY. EXPECT INCREASING SOUTHERLY WINDS AHEAD OF THE TROUGH TO
BRING WARMER AIR TO THE AREA AS WELL...WITH 925MB TEMPS PROGGED TO
CLIMB TO 14-17C ON WEDNESDAY AND THURSDAY...THEN TO 16-19C ON
FRIDAY. DPVA FORCING WITH THE TROUGH SHOULD APPROACH THE AREA FRIDAY
NIGHT...ALONG WITH A SURFACE COLD FRONT. ALL INDICATIONS ARE THAT
THE SOUTHERN PORTION OF THE TROUGH AND COLD FRONT WILL PASS THROUGH
THE FORECAST AREA EITHER SATURDAY OR SATURDAY NIGHT. ONCE THE TROUGH
AXIS PASSES...THE PRECIPITATION WILL END. PLAN ON A COOLER SATURDAY
DUE TO THE COMBINATION OF THE FRONTAL PASSAGE AND PRECIPITATION.
FOR SUNDAY AND EVEN HEADING INTO NEXT WEEK...GOOD MODEL CONTINUITY
EXISTS OF RIDGING STRENGTHENING ACROSS THE WESTERN U.S. AND INTO
SOUTHWEST CANADA. THIS WILL EVENTUALLY SET UP SOME TROUGHING
DOWNSTREAM OVER THE GREAT LAKES REGION. THE 22.12Z ECMWF IS VERY
QUICK AT DEVELOPING THIS TROUGHING...PHASING THE SOUTHERN PORTION OF
THE TROUGH ON SATURDAY WITH TROUGHING TRYING TO SET UP OVER THE
GREAT LAKES REGION. THE RESULT IS A WOUND UP LOW NEAR CHICAGO AT 12Z
SUNDAY. DO NOT HAVE MUCH CONFIDENCE OF THIS OCCURRING...BEING A
PHASING SCENARIO...THUS HAVE WENT WITH THE IDEA OF DRYING COMING IN
BEHIND THE SOUTHERN PORTION OF THE TROUGH. TEMPERATURES LOOK TO BE
JUST SLIGHTLY COOLER ON SUNDAY AS 925MB TEMPS FALL TO 10-13C.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1229 PM CDT SUN SEP 22 2013
HIGH PRESSURE WILL BE THE DOMINANT WEATHER FEATURE THROUGH MONDAY.
PRESSURE GRADIENT BETWEEN THE SURFACE HIGH CENTERED OVER THE GREAT
LAKES REGION AND AN AREA OF LOW PRESSURE MOVING INTO THE HIGH PLAINS
WILL PRODUCE SOUTHEAST WINDS IN THE 7-11KT RANGE THROUGH TONIGHT AND
IN THE 12-16KT RANGE BY LATER MONDAY MORNING WITH SOME HIGHER GUSTS.
WINDS OVERNIGHT SHOULD PREVENT FOG FORMATION IN THE MISSISSIPPI
RIVER VALLEY/KLSE TAF SITE...BUT MAY HAVE TO KEEP AN EYE ON THIS. IF
WINDS DO DECOUPLE MORE IN THE MISSISSIPPI RIVER VALLEY...SOME RIVER
FOG/STRATUS WILL BE POSSIBLE...BUT RIGHT NOW THIS HIGHLY DOUBTFUL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS