Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/09/12
AREA FORECAST DISCUSSION
NWS DENVER CO
924 AM MDT SUN OCT 7 2012
.UPDATE...PATCHY FOG IN THE LOWER SOUTH PLATTE RIVER VALLEY HAS
DISSIPATED. SUNNY SKIES ARE EXPECTED FOR THE REST OF THE DAY WITH
ONLY A FEW WISPY CIRRUS. TEMPERATURES ON TRACK TO REACH THE LOWER
50S ON THE PLAINS WITH SLIGHTLY COOLER READINGS OVER THE SNOW
COVERED NORTHEAST CORNER.
GIVEN THE WIDESPREAD HARD FREEZE LAST NIGHT...WE WILL NO LONGER
ISSUE FREEZE WARNINGS AS THE EFFECTIVE GROWING SEASON HAS COME TO
AN END.
&&
.AVIATION...NEARLY CLOUD FREE SKIES EXPECTED THROUGH TONIGHT WITH
UNLIMITED VISIBILITY. WEAK AND FAIRLY NORMAL DIURNAL WIND PATTERNS
EXPECTED PER ONGOING TAFS.
&&
.PREV DISCUSSION... /ISSUED 333 AM MDT SUN OCT 7 2012/
SHORT TERM...NNW FLOW ALOFT WILL BE OVER THE AREA THRU TONIGHT
WITH DRY CONDITIONS EXPECTED. MAIN CONCERN FOR THIS MORNING WILL
BE FOG POTENTIAL OVER NERN CO. SO FAR THE ONLY PLACE WITH FOG IS
OVER THE FAR NERN CORNER WHERE SKIES HAVE BEEN CLEAR OVERNIGHT.
CLOSER TO THE FRONT RANGE LOW LVL CLOUDS HAVE REMAINED IN PLACE
BUT HAVE BEEN SLOWLY DIMINISHING THE LAST FEW HOURS. AT THIS TIME
WILL KEEP AREAS OF FOG OVER THE PLAINS WHERE SKIES HAVE BEEN
GENERALLY CLEAR AND ONLY MENTION PATCHY FOG CLOSER TO THE
FOOTHILLS. AS FAS AS AFTN HIGHS WILL KEEP HIGHS IN THE LOWER TO
MID 50S ACROSS NERN CO FOR THIS AFTN. FOR TONIGHT SHOULD SEE
MAINLY CLEAR SKIES. MAY SEE SOME GUSTY WINDS IN THE MTNS AND
HIGHER FOOTHILLS LATE TONIGHT AS A WK MTN WAVE DEVELOPS.
LONG TERM...NORTHERN COLORADO WILL BE UNDER A MODERATE NORTHWEST
FLOW PATTERN THROUGH MIDWEEK WITH A DRY AIRMASS IN PLACE. THERE
WILL BE A WEAK TROF WHICH MOVES THROUGH THE NORTHERN PLAINS STATES
ON TUESDAY. THERE WILL BE AN ASSOCIATED COLD FRONT WHICH WILL COOL
TEMPERATURES ACROSS NORTHEAST COLORADO ON TUESDAY AS LOW LEVEL
INVERSIONS REMAIN IN PLACE. LATEST NAM BRINGS IN SOME LOW LEVEL
MOISTURE AND POTENTIAL STRATUS OVER THE PLAINS WHILE THE GFS AND
EUROPEAN ARE DRY. APPEARS MOST OF THE MOISTURE WITH THIS SYSTEM WILL
BE TOO FAR NORTH AND EAST OF COLORADO FOR ANY BENEFIT. WARMER
AGAIN ON WEDNESDAY AS HEIGHTS BUILD AS TEMPERATURES RETURN CLOSE
TO CLIMATE NORMALS FOR THIS TIME OF YEAR.
THE NEXT WEATHER MAKER WILL BE CLOSED LOW WHICH WILL BE OFF THE
SOUTHERN CALIFORNIA COAST BY THURSDAY WHICH WILL RESULT IN SOME
DOWNSTREAM RIDGING ACROSS COLORADO. THE FLOW ALOFT WILL SHIFT WEST
TO SOUTHWEST THURSDAY AND FRIDAY AS MOISTURE VALUES SLOWLY
ELEVATE. THE LOW IS PROGGED TO EJECT INTO COLORADO SOMETIME IN THE
FRIDAY THROUGH SATURDAY TIME FRAME DEPENDING ON WHICH MODEL.
SOLUTIONS VARY FROM THE SLOWER GFS SOLUTION TO THE FASTEST
EUROPEAN. SEEMS LIKE THERE IS EVEN MORE VARIATION IN THE SOLUTIONS
TODAY COMPARED TO YESTERDAY SO FORECAST CONFIDENCE NOT VERY HIGH.
TYPICALLY THESE SYSTEMS END UP BEING SLOWER THAN FORECAST. NO
MAJOR CHANGES PLANNED IN UPCOMING FORECAST PACKAGE FOR THE LONG
TERM AND WILL KEEP LOW POPS FOR THE ENTIRE AREA ON FRIDAY AND SATURDAY.
AVIATION...SO FAR THE HRRR AND THE RAP ARE NOT REAL EXCITED ABOUT
LIFR CONDITIONS IN THE 10Z-15Z TIME PERIOD AS BOTH KEEP LIFR
CONDITIONS TO THE NE OF THE AIRPORT. RAP STILL SHOWS A WEAK DENVER
CYCLONE NR THE AIRPORT BY 12Z SO AM TEMPTED TO LEAVE IN A BRIEF 3
HR WINDOW FM 12Z-15Z FOR SOME LOWER CEILINGS AND FOG FOR NOW AS
SKIES HAVE STARTED TO CLEAR. FOR THIS AFTN AND TONIGHT EXPECT VFR
CONDITIONS. WINDS WILL BE LIGHT AND VARIABLE THIS MORNING AND THEN
BECOME LIGHT NLY BY AFTN. FOR TONIGHT WINDS SHOULD BECOME
DRAINAGE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....ENTREKIN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS DENVER CO
333 AM MDT SUN OCT 7 2012
.SHORT TERM...NNW FLOW ALOFT WILL BE OVER THE AREA THRU TONIGHT
WITH DRY CONDITIONS EXPECTED. MAIN CONCERN FOR THIS MORNING WILL
BE FOG POTENTIAL OVER NERN CO. SO FAR THE ONLY PALCE WITH FOG IS
OVER THE FAR NERN CORNER WHERE SKIES HAVE BEEN CLEAR OVERNIGHT.
CLOSER TO THE FRONT RANGE LOW LVL CLOUDS HAVE REMAINED IN PLACE
BUT HAVE BEEN SLOWLY DIMINISHING THE LAST FEW HOURS. AT THIS TIME
WILL KEEP AREAS OF FOG OVER THE PLAINS WHERE SKIES HAVE BEEN
GENERALLY CLEAR AND ONLY MENTION PATCHY FOG CLOSER TO THE
FOOTHILLS. AS FAS AS AFTN HIGHS WILL KEEP HIGHS IN THE LOWER TO
MID 50S ACROSS NERN CO FOR THIS AFTN. FOR TONIGHT SHOULD SEE
MAINLY CLEAR SKIES. MAY SEE SOME GUSTY WINDS IN THE MTNS AND
HIGHER FOOTHILLS LATE TONIGHT AS A WK MTN WAVE DEVELOPS.
.LONG TERM...NORTHERN COLORADO WILL BE UNDER A MODERATE NORTHWEST
FLOW PATTERN THROUGH MIDWEEK WITH A DRY AIRMASS IN PLACE. THERE
WILL BE A WEAK TROF WHICH MOVES THROUGH THE NORTHERN PLAINS STATES
ON TUESDAY. THERE WILL BE AN ASSOCIATED COLD FRONT WHICH WILL COOL
TEMPERATURES ACROSS NORTHEAST COLORADO ON TUESDAY AS LOW LEVEL
INVERSIONS REMAIN IN PLACE. LATEST NAM BRINGS IN SOME LOW LEVEL
MOISTURE AND POTENTIAL STRATUS OVER THE PLAINS WHILE THE GFS AND
EUROPEAN ARE DRY. APPEARS MOST OF THE MOISTURE WITH THIS SYSTEM WILL
BE TOO FAR NORTH AND EAST OF COLORADO FOR ANY BENEFIT. WARMER
AGAIN ON WEDNESDAY AS HEIGHTS BUILD AS TEMPERATURES RETURN CLOSE
TO CLIMATE NORMALS FOR THIS TIME OF YEAR.
THE NEXT WEATHER MAKER WILL BE CLOSED LOW WHICH WILL BE OFF THE
SOUTHERN CALIFORNIA COAST BY THURSDAY WHICH WILL RESULT IN SOME
DOWNSTREAM RIDGING ACROSS COLORADO. THE FLOW ALOFT WILL SHIFT WEST
TO SOUTHWEST THURSDAY AND FRIDAY AS MOISTURE VALUES SLOWLY
ELEVATE. THE LOW IS PROGGED TO EJECT INTO COLORADO SOMETIME IN THE
FRIDAY THROUGH SATURDAY TIME FRAME DEPENDING ON WHICH MODEL.
SOLUTIONS VARY FROM THE SLOWER GFS SOLUTION TO THE FASTEST
EUROPEAN. SEEMS LIKE THERE IS EVEN MORE VARIATION IN THE SOLUTIONS
TODAY COMPARED TO YESTERDAY SO FORECAST CONFIDENCE NOT VERY HIGH.
TYPICALLY THESE SYSTEMS END UP BEING SLOWER THAN FORECAST. NO
MAJOR CHANGES PLANNED IN UPCOMING FORECAST PACKAGE FOR THE LONG
TERM AND WILL KEEP LOW POPS FOR THE ENTIRE AREA ON FRIDAY AND SATURDAY.
&&
.AVIATION...SO FAR THE HRRR AND THE RAP ARE NOT REAL EXCITED ABOUT
LIFR CONDITIONS IN THE 10Z-15Z TIME PERIOD AS BOTH KEEP LIFR
CONDITIONS TO THE NE OF THE AIRPORT. RAP STILL SHOWS A WEAK DENVER
CYCONE NR THE AIRPORT BY 12Z SO AM TEMPTED TO LEAVE IN A BRIEF 3
HR WINDOW FM 12Z-15Z FOR SOME LOWER CEILINGS AND FOG FOR NOW AS
SKIES HAVE STARTED TO CLEAR. FOR THIS AFTN AND TONIGHT EXPECT VFR
CONDITIONS. WINDS WILL BE LIGHT AND VARIABLE THIS MORNING AND THEN
BECOME LIGHT NLY BY AFTN. FOR TONIGHT WINBDS SHOULD BECOME
DRAINAGE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ038>051.
&&
$$
SHORT TERM...RPK
LONG TERM....ENTREKIN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1039 PM EDT MON OCT 8 2012
.SYNOPSIS...
LOW PRESSURE FORMING ALONG THE MID ATLANTIC COAST OVERNIGHT
WILL SLOWLY TRACK NORTHEAST...PASSING EAST OF THE TRI-STATE AREA
TUESDAY EVENING. HIGH PRESSURE THEN BRIEFLY BUILDS BACK IN BEHIND
THE LOW TUESDAY NIGHT. A COLD FRONT MOVES THROUGH WEDNESDAY
AFTERNOON AND EVENING...WITH HIGH PRESSURE BUILDING IN ON
THURSDAY. ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY...FOLLOWED BY
HIGH PRESSURE ON SATURDAY. A WARM FRONT WILL THEN PASS BY ON
SUNDAY...FOLLOWED BY A COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
00Z KOKX SHOWS A STRONG DRY LAYER BETWEEN 975-725 HPA AND THE 00Z
KALY SOUND FROM THE SURFACE-575 HPA. THIS GOES ALONG WAY TO
EXPLAINING WHY ANY MEASURABLE RAINFALL HAS BASICALLY REMAINED
OFFSHORE SO FAR THIS EVENING. THE HRRR AND RUC ARE HANDLING THE
CURRENT SITUATION THE BEST...SO HAVE USED TO UPDATE THE FORECAST
FOR OVERNIGHT...SIGNIFICANTLY LOWERING POPS...ESPECIALLY ACROSS
THE NORTHERN INTERIOR AND NW 1/3 OF THE CWA.
LOOKING FURTHER AT THE NAM - GIVEN THE VORTICITY MINIMA IT
FORECASTS AT 700 HPA OVER THE AREA OVERNIGHT - IT IS SURPRISING
THAT IT IS FORECASTING AS MUCH RAIN AS IT DOES. TYPICALLY WITH
THESE FEATURES AT 700 HPA...IT GOES WITH MINIMAL PRECIPITATION AND
ENDS UP BEING CORRECT. SO THE LOWER POPS ARE ALSO CONSISTENT WITH
THE NAM 700 HPA VORTICITY FIELDS.
STILL LOOKS LIKE THE TWIN FORKS COULD GET SOME LIGHT-MODERATE RAIN
LATE - OTHERWISE AT MOST A TENTH OF AN INCH - WITH MOST AREAS
CLOSER TO 0.01 INCHES.
TEMPERATURE FORECAST ON TRACK BASED ON MAV/MET BLEND WITH NEAR
NORMAL LOWS EXPECTED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
RAIN WILL BE LIKELY DURING THE MORNING HOURS...ESPECIALLY ALONG THE
COAST. THERE WILL BE PLENTY OF LOW-LEVEL MOISTURE IN PLACE WITH A
LOW-LEVEL NE FLOW AND A SW FLOW ALOFT. CONDITIONS WILL DRY OUT
FROM WEST TO EAST DURING THE AFTERNOON HOURS AS THE LOW PASSES TO
THE E AND THEN NE BY EVE. HIGHS WILL BE AROUND 60...WHICH IS
SEVERAL DEGREES BELOW NORMAL.
FOR TUE NIGHT....WITH WEAK LOW-LEVEL WARM ADVECTION...STRATUS
WILL REMAIN ACROSS THE ENTIRE AREA. THERE MAY EVEN BE A LITTLE
DRIZZLE AND/OR LIGHT RAIN DEVELOPING OVERNIGHT WITH AN E/SE
FLOW...ESPECIALLY ACROSS THE HILLS NORTH AND WEST OF NYC. LOWS
WILL ONCE AGAIN BE IN THE MID 40S TO AROUND 50.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THE LONGWAVE PATTERN DURING THE LONG TERM PERIOD IS FORECAST TO BE
PROGRESSIVE WITH A LACK OF DEEP AMPLIFICATION. IN
SHORT...RELATIVELY QUICK MOVING SURFACE FEATURES PASS THROUGH THE
FORECAST AREA.
ON WEDNESDAY...A PRE-FRONTAL SURFACE TROUGH MOVES THROUGH. IT LOOKS
LIKE THERE WILL BE DEEP ENOUGH MOISTURE TO WARRANT SLIGHT CHANCE
POPS. BY THE TIME THE TRAILING COLD FRONT ARRIVES LATE IN THE DAY
INTO THE EVENING HOURS....MODELS SHOW DRYING OF THE COLUMN. WILL
THEREFORE CARRY ONLY SLIGHT CHANCE POPS FOR THIS PERIOD. LEANED A
LITTLE MORE TOWARDS THE COOLER NAM MOS DUE TO THE ANTICIPATED CLOUD
COVER...HOWEVER...HIGH TEMPERATURES NEAR NORMAL.
HIGH PRESSURE BUILDS IN ON THURSDAY BEHIND THE COLD FRONT. BUT
BECAUSE OF THE PROGRESSIVE FLOW...RISING HEIGHTS AND SOME AIR MASS
MODIFICATION/MODERATION IS FORECAST BY LATE IN THE DAY. AFTERNOON
HIGHS ARE NOT EXPECTED TO BE SIGNIFICANTLY COOLER...BUT STILL
FALLING BELOW NORMAL LEVELS.
THE NEXT COLD FRONT PASSAGE IS EXPECTED ON FRIDAY. MODELS SHOWING
ONLY LIGHT QPF OUTPUT...SO WON`T BUMP UP POPS JUST YET FROM THE
CURRENT FORECAST OF SLIGHT CHANCE.
HIGH PRESSURE RETURNS ON SATURDAY. THE ORIGIN OF THIS AIRMASS WILL
BE SOMEWHAT MORE DIRECT FROM CANADA WITH LESS TIME TO MODIFY.
THEREFORE EXPECTING TEMPERATURES COOLER THAN THOSE USHERED IN BY
THE HIGH PRESSURE SYSTEM ON THURSDAY.
WITH THE CENTER OF THE HIGH OFFSHORE ON SUNDAY...A RETURN SOUTHERLY
FLOW AND WARM FRONT ENTER THE REGION. MODELS HAVE BEEN TRENDING
FARTHER NORTH REGARDING THE COVERAGE OF QPF ASSOCIATED WITH THE WARM
FRONT. WILL KEEP IN A SLIGHT CHANCE OF SHOWERS NORTH OF THE CITY
LATE SATURDAY INTO SUNDAY MORNING...BUT IT IS LOOKING MORE LIKE A
COMPLETELY DRY UPCOMING WEEKEND ACROSS THE AREA. A TRAILING COLD
FRONT DROPS DOWN FROM THE NORTH ON MONDAY. WITH THE TIMING OF ITS
PASSAGE SOMEWHAT UNCERTAIN...WILL GO WITH SLIGHT CHANCE POPS SUNDAY
NIGHT THROUGH MONDAY NIGHT...BUT MOST OF THE TIME SHOULD BE DRY.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
AS HIGH PRES LIFTS NE INTO THE CANADIAN MARITIMES TONIGHT...LOW
PRES DEVELOPING OFF THE NORTH CAROLINA COAST WILL TRACK NE
THROUGH TUE MORNING...PASSING E OF LONG ISLAND TUE NIGHT.
DRY AIR BELOW 10K HAS BEEN THE CAUSE OF RAIN ERODING AS IT
APPROACHES THE AREA FROM SE PA/MD/VA. THERE ARE A FEW NARROW BANDS
THAT REMAIN...BUT ARE EXPECTED TO MISS MOST TERMINALS. KSWF/KJFK
MAY SEE A BRIEF PERIOD OF LIGHT RAIN THROUGH 05Z...BUT THE MAJORITY
OF THE ACTIVITY IS EXPECTED TO REMAIN TO OUR S AND E. KISP/KGON
HAVE THE HIGHEST CHC OF SEEING ANY PRECIP FROM THE OFFSHORE LOW
LATE TONIGHT. IN ADDITION...AS A MID LEVEL DISTURBANCE MOVES
CLOSER TO THE AREA...RAIN COULD REDEVELOP AT WESTERN TERMINALS AS
WELL...SO HAVE KEPT A PERIOD OF PREVAILING RAIN LATE TONIGHT
ALTHOUGH TIMING MAY BE OFF.
LOW LEVEL MOISTURE WILL INCREASE AND STILL EXPECTING CIGS TO FALL
BELOW 3 KFT OVERNIGHT...BUT THINKING NOT UNTIL AFT 06Z. VSBYS
EXPECTED TO REMAIN AOA 6SM EXCEPT IN ANY LOCALIZED HEAVIER
RAINFALL. THE CHANCE OF THIS IS TOO SMALL...THEREFORE HAVE REMOVED
ANY VSBYS LOWER THAN 6SM. CONDS EXPECTED TO REMAIN ABOVE IFR THROUGH
THE PERIOD WITH MARGINAL IMPROVEMENT TUESDAY AFTN.
WINDS EXPECTED TO BECOME NE AT ALL TERMINALS BY 06Z. AS THE PRES
GRADIENT TIGHTENS OVERNIGHT WINDS WILL INCREASE FURTHER AND EXPECT
8-15 KT ON TUE...HIGHEST SPEEDS AT KGON.
OUTLOOK FOR 00Z TUESDAY THROUGH SATURDAY...
.TUESDAY NIGHT...MVFR AND WDLY SCT SHOWERS POSSIBLE.
.WEDNESDAY...MVFR CONDS POSSIBLE IN -SHRA WITH COLD FRONT
PASSAGE.
.THURSDAY-SATURDAY...VFR.
&&
.MARINE...
MINOR ADJUSTMENTS MADE TO REFLECT LATEST TRENDS IN OBSERVATIONS AND
GUIDANCE. APPEARS WINDS/SEAS WILL REMAIN BENIGN INTO THE OVERNIGHT
HOURS.
A SCA HAS BEEN HOISTED FOR THE OCEAN WATERS TUE-WED MORNING. A
STRENGTHENING NE FLOW AHEAD OF LOW PRESSURE TRACKING NE FROM THE
MID ATLANTIC COAST WILL PRODUCE MARGINAL WIND GUSTS AND SEAS RIGHT
AROUND 5 FT. CONDITIONS WILL BRIEFLY IMPROVE TUE NIGHT AS THE LOW
PASSES TO THE NORTH AND EAST OF THE WATERS. THE REMAINDER OF THE
WATERS SHOULD EXPERIENCE SUB-SCA CONDITIONS TONIGHT-TUESDAY NIGHT.
LOOKS LIKE SUB SCA CONDITIONS SHOULD CONTINUE THROUGH WEDNESDAY
AFTERNOON...BUT WITH A COLD FRONT MOVING THROUGH IN THE
EVENING...WINDS AND SEAS PICK UP...AND MOST IF NOT ALL OF THE AREA
WATERS STAND A GOOD CHANCE OF SCA CONDITIONS. WINDS AND SEAS
SUBSIDE THROUGH THURSDAY WITH HIGH PRESSURE AND A WEAK PRESSURE
GRADIENT IN CONTROL...SO BY LATE IN THE DAY...ALL WATERS ARE
EXPECTED TO HAVE SUB SCA CONDITIONS. ANOTHER COLD FRONT APPROACHES
BEFORE MOVING THROUGH DURING FRIDAY. SCA CONDITIONS PROBABLE ON
SOME OF THE WATERS DURING THIS PERIOD. HIGH PRESSURE WITH A WEAK
PRESSURE RESTORES TRANQUIL CONDITIONS AGAIN ON SATURDAY.
&&
.HYDROLOGY...
RAINFALL FROM LATE THIS AFTERNOON THROUGH TUESDAY MORNING WILL
TOTAL FROM AROUND A FEW HUNDREDTHS OF OF AN INCH ACROSS THE LOWER
HUDSON VALLEY INTO PORTIONS OF NORTHEASTERN NEW JERSEY TO AROUND A
QUARTER TO ONE THIRD OF ACROSS EASTERN LONG ISLAND. THE RAIN WILL
BE MAINLY LIGHT. NO FLOODING IS EXPECTED.
NO SIGNIFICANT RAINFALL EXPECTED MID WEEK THROUGH THE WEEKEND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...MALOIT
SHORT TERM...DW
LONG TERM...JC
AVIATION...24
MARINE...MALOIT/DW/JC
HYDROLOGY...MALOIT/DW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1008 PM EDT MON OCT 8 2012
.SYNOPSIS...
LOW PRESSURE FORMING ALONG THE MID ATLANTIC COAST THIS EVENING
WILL SLOWLY TRACK NORTHEAST...PASSING EAST OF THE TRI-STATE AREA
TUESDAY EVENING. HIGH PRESSURE THEN BRIEFLY BUILDS BACK IN BEHIND
THE LOW TUESDAY NIGHT. A COLD FRONT MOVES THROUGH WEDNESDAY
AFTERNOON AND EVENING...WITH HIGH PRESSURE BUILDING IN ON
THURSDAY. ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY...FOLLOWED BY
HIGH PRESSURE ON SATURDAY. A WARM FRONT WILL THEN PASS BY ON
SUNDAY...FOLLOWED BY A COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
00Z KOKX SHOWS A STRONG DRY LAYER BETWEEN 975-725 HPA AND THE 00Z
KALY SOUND FROM THE SURFACE-575 HPA. THIS GOES ALONG WAY TO
EXPLAINING WHY ANY MEASURABLE RAINFALL HAS BASICALLY REMAINED
OFFSHORE SO FAR THIS EVENING. THE HRRR AND RUC ARE HANDLING THE
CURRENT SITUATION THE BEST...SO HAVE USED TO UPDATE THE FORECAST
FOR OVERNIGHT...SIGNIFICANTLY LOWERING POPS...ESPECIALLY ACROSS
THE NORTHERN INTERIOR AND NW 1/3 OF THE CWA.
LOOKING FURTHER AT THE NAM - GIVEN THE VORTICITY MINIMA IT
FORECASTS AT 700 HPA OVER THE AREA OVERNIGHT - IT IS SURPRISING
THAT IT IS FORECASTING AS MUCH RAIN AS IT DOES. TYPICALLY WITH
THESE FEATURES AT 700 HPA...IT GOES WITH MINIMAL PRECIPITATION AND
ENDS UP BEING CORRECT. SO THE LOWER POPS ARE ALSO CONSISTENT WITH
THE NAM 700 HPA VORTICITY FIELDS.
STILL LOOKS LIKE THE TWIN FORKS COULD GET SOME LIGHT-MODERATE RAIN
LATE - OTHERWISE AT MOST A TENTH OF AN INCH - WITH MOST AREAS
CLOSER TO 0.01 INCHES.
TEMPERATURE FORECAST ON TRACK BASED ON MAV/MET BLEND WITH NEAR
NORMAL LOWS EXPECTED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
RAIN WILL BE LIKELY DURING THE MORNING HOURS...ESPECIALLY ALONG THE
COAST. THERE WILL BE PLENTY OF LOW-LEVEL MOISTURE IN PLACE WITH A
LOW-LEVEL NE FLOW AND A SW FLOW ALOFT. CONDITIONS WILL DRY OUT
FROM WEST TO EAST DURING THE AFTERNOON HOURS AS THE LOW PASSES TO
THE E AND THEN NE BY EVE. HIGHS WILL BE AROUND 60...WHICH IS
SEVERAL DEGREES BELOW NORMAL.
FOR TUE NIGHT....WITH WEAK LOW-LEVEL WARM ADVECTION...STRATUS
WILL REMAIN ACROSS THE ENTIRE AREA. THERE MAY EVEN BE A LITTLE
DRIZZLE AND/OR LIGHT RAIN DEVELOPING OVERNIGHT WITH AN E/SE
FLOW...ESPECIALLY ACROSS THE HILLS NORTH AND WEST OF NYC. LOWS
WILL ONCE AGAIN BE IN THE MID 40S TO AROUND 50.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THE LONGWAVE PATTERN DURING THE LONG TERM PERIOD IS FORECAST TO BE
PROGRESSIVE WITH A LACK OF DEEP AMPLIFICATION. IN
SHORT...RELATIVELY QUICK MOVING SURFACE FEATURES PASS THROUGH THE
FORECAST AREA.
ON WEDNESDAY...A PRE-FRONTAL SURFACE TROUGH MOVES THROUGH. IT LOOKS
LIKE THERE WILL BE DEEP ENOUGH MOISTURE TO WARRANT SLIGHT CHANCE
POPS. BY THE TIME THE TRAILING COLD FRONT ARRIVES LATE IN THE DAY
INTO THE EVENING HOURS....MODELS SHOW DRYING OF THE COLUMN. WILL
THEREFORE CARRY ONLY SLIGHT CHANCE POPS FOR THIS PERIOD. LEANED A
LITTLE MORE TOWARDS THE COOLER NAM MOS DUE TO THE ANTICIPATED CLOUD
COVER...HOWEVER...HIGH TEMPERATURES NEAR NORMAL.
HIGH PRESSURE BUILDS IN ON THURSDAY BEHIND THE COLD FRONT. BUT
BECAUSE OF THE PROGRESSIVE FLOW...RISING HEIGHTS AND SOME AIR MASS
MODIFICATION/MODERATION IS FORECAST BY LATE IN THE DAY. AFTERNOON
HIGHS ARE NOT EXPECTED TO BE SIGNIFICANTLY COOLER...BUT STILL
FALLING BELOW NORMAL LEVELS.
THE NEXT COLD FRONT PASSAGE IS EXPECTED ON FRIDAY. MODELS SHOWING
ONLY LIGHT QPF OUTPUT...SO WON`T BUMP UP POPS JUST YET FROM THE
CURRENT FORECAST OF SLIGHT CHANCE.
HIGH PRESSURE RETURNS ON SATURDAY. THE ORIGIN OF THIS AIRMASS WILL
BE SOMEWHAT MORE DIRECT FROM CANADA WITH LESS TIME TO MODIFY.
THEREFORE EXPECTING TEMPERATURES COOLER THAN THOSE USHERED IN BY
THE HIGH PRESSURE SYSTEM ON THURSDAY.
WITH THE CENTER OF THE HIGH OFFSHORE ON SUNDAY...A RETURN SOUTHERLY
FLOW AND WARM FRONT ENTER THE REGION. MODELS HAVE BEEN TRENDING
FARTHER NORTH REGARDING THE COVERAGE OF QPF ASSOCIATED WITH THE WARM
FRONT. WILL KEEP IN A SLIGHT CHANCE OF SHOWERS NORTH OF THE CITY
LATE SATURDAY INTO SUNDAY MORNING...BUT IT IS LOOKING MORE LIKE A
COMPLETELY DRY UPCOMING WEEKEND ACROSS THE AREA. A TRAILING COLD
FRONT DROPS DOWN FROM THE NORTH ON MONDAY. WITH THE TIMING OF ITS
PASSAGE SOMEWHAT UNCERTAIN...WILL GO WITH SLIGHT CHANCE POPS SUNDAY
NIGHT THROUGH MONDAY NIGHT...BUT MOST OF THE TIME SHOULD BE DRY.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
HIGH PRES OVER THE AREA MOVES OFFSHORE THIS EVENING. LOW PRES
DEVELOPING OFF THE NORTH CAROLINA COAST TRACKS NE THROUGH TUE
MORNING...PASSING E OF LONG ISLAND TUE NIGHT.
MAJORITY OF RAIN REMAINS OFFSHORE WITH A JUST A FEW AREAS OF LIGHT
RAIN TRACKING N OF NYC EARLIER THIS EVE. AREA OF RAIN EXTENDING
FROM SE PA THROUGH VA IN ASSOCIATION WITH AN UPPER LEVEL
DISTURBANCE LOOKS TO IMPACT THE TERMINALS AFTER 02Z...ALTHOUGH SEEING
SOME INDICATION OF DRYING AS IT APPROACHES. STARTING TO THINK THAT
THE PRECIP ASSOCIATED WITH THE OFFSHORE LOW WILL REMAIN OFFSHORE
AND WE MAY JUST SEE SOME INTERMITTENT LIGHT RAIN AS THE UPPER
DISTURBANCE LIFTS THROUGH OVERNIGHT INTO TUE MORNING...ESPECIALLY
AT NYC TERMINALS/KHPN/KSWF. THE DURATION OF RAIN IN THE TAFS MAY
BE OVERDONE...BUT CONFIDENCE IS NOT YET HIGH ENOUGH TO ALTER ATTM.
LOW LEVEL MOISTURE WILL INCREASE AND STILL EXPECTING CIGS TO FALL
BELOW 3 KFT OVERNIGHT...BUT THINKING NOT UNTIL AFT 06Z. VSBYS
EXPECTED TO REMAIN AOA 6SM EXCEPT IN ANY LOCALIZED HEAVIER
RAINFALL. CONDS EXPECTED TO REMAIN ABOVE IFR THROUGH THE PERIOD
WITH MARGINAL IMPROVEMENT TUESDAY AFTN.
WINDS REMAIN VRB AT MOST TERMINALS...BUT ARE EXPECTED TO BECOME NE
OVER THIS EVE. AS THE PRES GRADIENT TIGHTENS OVERNIGHT WINDS WILL
INCREASE FURTHER AND EXPECT 8-15 KT ON TUE...HIGHEST SPEEDS AT KGON.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MODERATE CONFIDENCE IN WIND FORECAST. CIGS
MAY REMAIN BLO 3 KFT LONGER THAN FORECAST TUE AFTN...THEN
UNCERTAIN WHETHER THEY DROP BACK BLO IN THE EVE.
KLGA FCSTER COMMENTS: MODERATE CONFIDENCE IN WIND FORECAST. CIGS
MAY REMAIN BLO 3K FT LONGER THAN FORECAST TUE AFTN...THEN
UNCERTAIN WHETHER THEY DROP BACK BLO IN THE EVE.
KEWR FCSTER COMMENTS: MODERATE CONFIDENCE IN WIND FORECAST. CIGS
MAY REMAIN BLO 3 KFT LONGER THAN FORECAST TUE AFTN...THEN
UNCERTAIN WHETHER THEY DROP BACK BLO IN THE EVE.
KTEB FCSTER COMMENTS: MODERATE CONFIDENCE IN WIND FORECAST. CIGS
MAY REMAIN BLO 3 KFT LONGER THAN FORECAST TUE AFTN...THEN
UNCERTAIN WHETHER THEY DROP BACK BLO IN THE EVE.
KHPN FCSTER COMMENTS: MODERATE CONFIDENCE IN WIND FORECAST. CIGS
MAY REMAIN BLO 3 KFT LONGER THAN FORECAST TUE AFTN...THEN
UNCERTAIN WHETHER THEY DROP BACK BLO IN THE EVE.
KISP FCSTER COMMENTS: MODERATE CONFIDENCE IN WIND FORECAST. CIGS
MAY IMPROVE ABOVE 3 KFT IN THE AFTN.
OUTLOOK FOR 00Z TUESDAY THROUGH SATURDAY...
.TUESDAY NIGHT...MVFR AND WDLY SCT SHOWERS POSSIBLE.
.WEDNESDAY...MVFR CONDS POSSIBLE IN -SHRA WITH COLD FRONT
PASSAGE.
.THURSDAY-SATURDAY...VFR.
&&
.MARINE...
MINOR ADJUSTMENTS MADE TO REFLECT LATEST TRENDS IN OBSERVATIONS AND
GUIDANCE. APPEARS WINDS/SEAS WILL REMAIN BENIGN INTO THE OVERNIGHT
HOURS.
A SCA HAS BEEN HOISTED FOR THE OCEAN WATERS TUE-WED MORNING. A
STRENGTHENING NE FLOW AHEAD OF LOW PRESSURE TRACKING NE FROM THE
MID ATLANTIC COAST WILL PRODUCE MARGINAL WIND GUSTS AND SEAS RIGHT
AROUND 5 FT. CONDITIONS WILL BRIEFLY IMPROVE TUE NIGHT AS THE LOW
PASSES TO THE NORTH AND EAST OF THE WATERS. THE REMAINDER OF THE
WATERS SHOULD EXPERIENCE SUB-SCA CONDITIONS TONIGHT-TUESDAY NIGHT.
LOOKS LIKE SUB SCA CONDITIONS SHOULD CONTINUE THROUGH WEDNESDAY
AFTERNOON...BUT WITH A COLD FRONT MOVING THROUGH IN THE
EVENING...WINDS AND SEAS PICK UP...AND MOST IF NOT ALL OF THE AREA
WATERS STAND A GOOD CHANCE OF SCA CONDITIONS. WINDS AND SEAS
SUBSIDE THROUGH THURSDAY WITH HIGH PRESSURE AND A WEAK PRESSURE
GRADIENT IN CONTROL...SO BY LATE IN THE DAY...ALL WATERS ARE
EXPECTED TO HAVE SUB SCA CONDITIONS. ANOTHER COLD FRONT APPROACHES
BEFORE MOVING THROUGH DURING FRIDAY. SCA CONDITIONS PROBABLE ON
SOME OF THE WATERS DURING THIS PERIOD. HIGH PRESSURE WITH A WEAK
PRESSURE RESTORES TRANQUIL CONDITIONS AGAIN ON SATURDAY.
&&
.HYDROLOGY...
RAINFALL FROM LATE THIS AFTERNOON THROUGH TUESDAY MORNING WILL
TOTAL FROM AROUND A TENTH OF AN INCH ACROSS THE LOWER HUDSON
VALLEY INTO PORTIONS OF NORTHEASTERN NEW JERSEY TO AROUND A THIRD
OF AN INCH FROM NYC TO SOUTHEASTERN CONNECTICUT. THE RAIN WILL BE
MAINLY LIGHT. NO FLOODING IS EXPECTED.
NO SIGNIFICANT RAINFALL EXPECTED MID WEEK THROUGH THE WEEKEND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...MALOIT
SHORT TERM...DW
LONG TERM...JC
AVIATION...24
MARINE...JC/MALOIT/DW
HYDROLOGY...DW
AREA FORECAST DISCUSSION
NWS TAUNTON MA
418 PM EDT SUN OCT 7 2012
.SYNOPSIS...
AN AREA OF RAIN WILL MOVE OFFSHORE IN THE NEXT FEW HOURS FOLLOWED
BY ANOTHER BAND OVERNIGHT. THE RAIN SHOULD COME TO AN END IN MOST
LOCATIONS SHORTLY AFTER MIDNIGHT. OTHERWISE...THE MAIN STORY THIS
WEEK WILL BE COOL FALL LIKE WEATHER WITH BELOW NORMAL TEMPERATURES.
A FEW SHOWERS ARE POSSIBLE TUE/WED...BUT A WASHOUT IS NOT
EXPECTED.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
LATEST REGIONAL RADAR MOSAIC SHOWING LIGHT RAIN MOVING ACROSS RI
AND SOUTHEAST MA LATE THIS AFTERNOON. LOOKING FARTHER WEST AROUND
4 PM...WATCHING AN AREA OF LIGHT RAIN BLOSSOMING UNDER THE
INFLUENCE OF A POTENT MID-LEVEL SHORTWAVE. BOTH THE 07/16Z HRRR AND
THE 07/18Z RAP LOOK TO HAVE THE BEST HANDLE ON THE RAINFALL
PATTERN...WHICH NOW LOOKS LIKE WILL COME IN TWO DISTINCT PERIODS.
CURRENT FORECAST POPS FALL INTO THE HIGH POP/LOW RAINFALL AMOUNT
CATEGORY. UPDATED THE RAINFALL TIMING BASED UPON THE 16Z HRRR AND
18Z RAP. CURRENT THINKING IS THE RAIN ACROSS SOUTHEAST MA AND RI
WILL MOVE OFFSHORE EARLY THIS EVENING...RESULTING IN A MAINLY DRY
PERIOD BEFORE A MID-LEVEL SHORTWAVE ARRIVES OVERNIGHT.
ONCE THIS SHORTWAVE PASSES BY...EXPECTING A DRYING AND CLEARING
TREND FROM WEST TO EAST LATE TONIGHT.
TEMPERATURES WERE A BLEND OF THE MAV/MET MOS GUIDANCE. NOT SURE WE
WILL HAVE ENOUGH TIME OF CLEAR SKIES TO GET MUCH FROST. DECIDED
NOT TO ISSUE A FROST ADVISORY AT THIS TIME AS TEMPERATURES ARE NOT
EXPECTED TO GET LOW ENOUGH.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
HIGH PRESSURE SHOULD MOVE ACROSS SOUTHERN NEW ENGLAND MONDAY...AND
REACH A POSITION NEAR NOVA SCOTIA MONDAY NIGHT. LIGHT NORTHWEST
WINDS BECOME LIGHT ONSHORE LATE MONDAY AFTERNOON INTO MONDAY
NIGHT. WELL BELOW NORMAL TEMPERATURES EXPECTED MONDAY DESPITE
PLENTY OF SUNSHINE TO START. INCREASING CLOUDS LATE IN THE DAY
INTO MONDAY NIGHT. LEFT A CHANCE OF RAIN LATE MONDAY NIGHT AS
ANOTHER LOW PRESSURE APPROACHES FROM THE SOUTH. THE CURRENT TIMING
MAY BE A BIT ON THE FAST SIDE.
TEMPERATURES WERE A BLEND OF THE MAV/MET MOS GUIDANCE ONCE AGAIN.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* COOL FALL-LIKE WEATHER MOST OF THE WEEK
* CONSIDERABLE CLOUDINESS TUE/WED WITH A FEW SHOWERS POSSIBLE
* STRONG COLD FRONTAL PASSAGES WED NIGHT AND AGAIN FRI
OVERVIEW AND MODEL PREFERENCES...
07/12Z MODEL GUIDANCE SUITE IN FAIRLY GOOD AGREEMENT THROUGH THE
LONG TERM WITH THEIR HANDLING OF THE SYNOPTIC PATTERN. THE LARGE
SCALE IS DEFINED BY A STRONG AND PERSISTENT HUDSON/S BAY VORTEX
WITH WAVE ENERGY WRAPPING THROUGH THE BASE OF ITS LONGWAVE TROF.
THE COMBINATION OF THIS TROF THE THE NW AND AN ATLANTIC RIDGE WILL
YIELD A FAIRLY PERSISTENT WSW JET OVER THE AREA...LEADING TO AN
UNSETTLED PERIOD THROUGH LATE WEEK...AFTER WHICH THE VORTEX WILL
BEGIN TO LIFT N WITH TIME. GIVEN THAT THERE IS REASONABLY GOOD
AGREEMENT BETWEEN THE MODELS...NOT PLANNING ON FAVORING ANY
PARTICULAR MODEL FOR THE BASELINE OF THIS FORECAST.
THEREFORE...WILL BEGIN WITH AN ECMWF/GFS BLEND AND MAKE MANUAL
ADJUSTMENTS FOR BETTER HANDLING OF THE SENSIBLE WX DETAILS.
DETAILS...
TUE INTO WED...
A RIDGE OF HIGH PRES WILL BE MOVING OVER THE AREA THROUGH THE
PERIOD THANKS TO CONFLUENT FLOW ALOFT OVER MUCH OF SRN NEW
ENGLAND. HOWEVER...A CONSTANT SHEAR VORTICITY MAXIMUM WILL ASSIST
IN THE MOVEMENT OF A SFC LOW PRES IN PROXIMITY OF THE 40/70
BENCHMARK THROUGH THE PERIOD. THE BEST LLJ ENERGY...MOISTURE...AND
F-GEN ARE WELL TO THE SW AND CLOSELY ASSOCIATED WITH THE LOW WITH
DRY AIR AND SUBSIDENCE OVER MUCH OF SRN NEW ENGLAND FROM THE HIGH
PRES. WITH MITIGATING FACTORS...IT APPEARS MODELS MAY BE A BIT TOO
ROBUST WITH PRECIP OUTPUT THROUGH THE PERIOD...BUT A FEW SHOWERS
CAN/T BE RULED GIVEN THE DIFFERENTIAL VORTICITY ADVECTION. WILL
GENERALLY CAP POPS AT LOW CHANCE OVER SE PORTIONS OF THE
FA...LOWER POPS TOWARD THE N AND W. MUCH OF THIS PERIOD WILL
LIKELY BE DRY. TUE H85 TEMPS REMAIN AROUND +2C WHILE WED THEY
INCREASE TO NEAR +8C...THEREFORE TEMPS WILL BE IN THE 50S TUE AND
THE 60S WED. MINS WILL LIKELY BE IN THE 40S.
WED EVENING INTO THU...
A STRONG KICKER TROF WILL BE ROTATING THROUGH SRN ONTARIO AND THE
GREAT LAKES. THE SFC REFLECTION IS A STRONG COLD FRONT WHICH WILL
CROSS THE REGION DURING THE OVERNIGHT WED NIGHT. SOUNDINGS SHOW
DECENT MOISTURE LOADING AND THERE ARE FAIRLY GOOD DYNAMICS WITH
THIS SYSTEM...SO WIDESPREAD WET WX IS LIKELY WITH THIS COLD FROPA.
THE FRONT IS CLOSELY ASSOCIATED WITH A 30-40KT LLJ AND H85 TEMPS
COOLING TO NEARLY 0C...SO THERE IS SOME LOW LVL INSTABILITY
POSSIBLE. GIVEN THESE FACTORS CANNOT RULE OUT THE POSSIBILITY OF
BRIEFLY HEAVY RAIN AND A/OR A LOW TOPPED SQUALL LINE ASSOCIATED
WITH THE FRONT ITSELF. THERE IS THE POSSIBILITY IT WILL SLOW
SOMEWHAT AS IT REACHES THE E COAST AS IT GETS WRAPPED UP WITH THE
WEAK LOW PRES OFFSHORE. IN ANY CASE...WET UNSETTLED WX WILL BE
LIKELY WED EVENING INTO THU MORNING...WITH COOL NW FLOW LIKELY
DURING THE DAY THU BEHIND THE FRONT.
FRI AND SAT...
WITH THE KICKER TROF FROM THU HAVING SHIFTED THE PERSISTENT
HUDSON BAY VORTEX FURTHER N AND E...A SE CONUS RIDGE WILL BE
ALLOWED TO SHIFT N WITH ITS ASSOCIATED STRONG HIGH PRES FRI INTO
SAT. THEREFORE DRY COOL WX WILL PREVAIL. MODELS SUGGEST A WEAK
CLIPPER SYSTEM MAY PASS TO THE N EARLY FRI...BUT GIVEN ITS CP
ORIGINS AND PASSAGE WELL TO THE N THIS MAY PASS THE REGION DRY
WITH THE RIDGE CONTINUALLY BUILDING AS IT PASSES.
SUN INTO EARLY NEXT WEEK...
AVAILABLE GUIDANCE SHOWS A VERY STRONG LOW PRES MOVING THROUGH
THE AREA BEGINNING SUN AFTERNOON WITH MORE WET WX POSSIBLE. BOTH
OPNL RUNS OF THE GFS AND ECMWF AS WELL AS MANY OF THEIR
COMPLIMENTARY ENSEMBLE MEMBERS ARE SHOWING THIS...SO CONFIDENCE
INA TRANSITION TOWARD WET WX LATE IN THE WEEKEND AND EARLY NEXT WEEK
IS A HIGHER THAN USUAL CONFIDENCE FORECAST FOR 7 DAYS OUT.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...HIGH CONFIDENCE. EXPECTING PRIMARILY VFR CIGS TONIGHT.
AREAS OF MVFR VSBYS IN HEAVIER RAINFALL. SHOULD LEAD TO DAMP
RUNWAYS AT LEAST. MODERATE CONFIDENCE IN MVFR CIGS ACROSS PORTIONS
OF SOUTHEAST MA AND THE COASTAL WATERS BETWEEN 03Z-09Z. LOW
CONFIDENCE IN IFR CONDITIONS OVERNIGHT. CLEARING FROM WEST TO EAST
AFTER 09/06Z WITH VFR TO PREVAIL MONDAY INTO MONDAY NIGHT.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE.
COMPLEX MIX OF VFR TO MVFR AND IFR WITH LOW PRESSURE MOVING SE OF
THE AREA. BEST CHANCE FOR LOWER CATEGORIES WILL BE IN SHOWERS
PARTICULARLY SE MA/RI TERMINALS.
THURSDAY AND FRIDAY...HIGH CONFIDENCE IN VFR CONDITIONS.
&&
.MARINE...
ISSUED A SMALL CRAFT ADVISORY ACROSS THE OUTER COASTAL WATERS
SOUTH AND EAST OF NANTUCKET DUE TO GUSTY WINDS AND BUILDING SEAS.
ELSEWHERE...EXPECTING RELATIVELY TRANQUIL CONDITIONS OTHER THAN
THE RAINFALL AND OCCASIONALLY LOWER VISIBILITY. COULD SEE ANOTHER
EPISODE FOR MARGINAL SMALL CRAFT ADVISORY CONDITIONS LATE MONDAY
NIGHT.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUE...MODERATE CONFIDENCE.
SCA LIKELY NEEDED FOR INCREASING WINDS 25-30 KT AND HIGH SEAS WITH
LOW PRESSURE OFF THE SE COAST. VSBYS LOWER IN SHOWERS.
WED INTO THU...
SMALL CRAFT CONDITIONS LOWER TUE NIGHT INTO WED WITH A PERIOD OF
QUIET BOATING WEATHER EXPECTED. HOWEVER A STRONG COLD FRONT WILL
APPROACH LATE IN THE DAY WED...CROSSING THE WATERS EARLY THU
MORNING. WINDS WILL INCREASE 25-30 KT BOTH BEFORE AND AFTER THE
COLD FRONTAL PASSAGE. SMALL CRAFT ADVISORIES MAY BE NEEDED...AND
THERE IS THE SLIGHT CHANCE FOR SOME GALE FORCE GUSTS PARTICULARLY
RIGHT AROUND THE TIME OF THE FRONTAL PASSAGE. MODERATE CONFIDENCE.
FRI...
MODERATE CONFIDENCE THAT SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE INTO THE DAY FRIDAY. EVEN THOUGH WINDS MAY SUBSIDE
SOMEWHAT THU NIGHT...THEY WILL PICK UP AGAIN TO 25 KT FRI.
SEAS...PARTICULARLY ON THE OUTER WATERS MAY EXCEED 5 FT DURING THE
PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 AM EDT MONDAY
FOR ANZ254-255.
&&
$$
SYNOPSIS...BELK/DOODY
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...DOODY
AVIATION...BELK/DOODY
MARINE...BELK/DOODY
AREA FORECAST DISCUSSION
NWS ALBANY NY
136 AM EDT SUN OCT 7 2012
.SYNOPSIS...
MUCH COOLER AIR WILL CONTINUE TO STREAM INTO OUR REGION
OVERNIGHT AS WEAK HIGH PRESSURE CRESTS ACROSS THE REGION. LOW
PRESSURE WILL MOVE ALONG A FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING US MORE UNSETTLED WEATHER FOR SUNDAY AFTERNOON INTO
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE REGION ON MONDAY AND
BRING FAIR AND SEASONABLE WEATHER FOR THE FIRST HALF OF THE WORK
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM EDT...A BAND OF LAKE EFFECT RAIN SHOWERS HAS
DEVELOPED OFF LAKE ONTARIO. WHILE THE MAJORITY OF THESE RAIN
SHOWERS ARE REMAINING CLOSE TO THE LAKESHORE AND ACROSS THE TUG
HILL...A FEW SHOWERS WILL MAKE IT INTO THE FAR WESTERN
ADIRONDACKS. AS THE FLOW SHIFTS...THIS BAND WILL GRADUALLY SHIFT
SOUTH...POSSIBLY AFFECTING PARTS OF THE WESTERN MOHAWK VALLEY BY
LATE TONIGHT. THIS IS BEING MODELED WELL BY THE LATEST HRRR AND
LOCAL WRF.
MEANWHILE...A SFC FRONTAL BOUNDARY CONTINUES TO MOVE TO THE SOUTH
AND EAST OF OUR AREA ACROSS EASTERN NEW ENGLAND AND DOWN OFF THE
MID ATLANTIC SEABOARD. MID AND HIGH LEVEL CLOUDS ARE ALREADY
BEGINNING TO STREAK INTO THE REGION FROM THE SOUTHWEST...AND WILL
CONTINUE TO INCREASE TOWARD DAYBREAK AS A WAVE OF LOW PRESSURE
DEVELOPS ALONG THE FRONTAL BOUNDARY TO OUR SOUTH.
MIN TEMPS OVERNIGHT WILL BE MUCH COOLER THAN RECENT NIGHTS.
HOWEVER...DUE TO SOME WIND PERSISTING...AND THE PROSPECTS FOR
INCREASING CLOUDS...HAVE RAISED FORECAST MINS A BIT...WITH
LOWS GENERALLY FALLING INTO THE UPPER 30S TO LOWER 40S IN MOST AREAS
BY DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
WHILE SFC CDFNT WILL STALL WELL OFFSHORE...THE COLD AIR REMAINS
SHALLOW AND THE H850 BAROCLINIC ZN/THERMAL RIBBON ONLY MOVES JUST
OFFSHORE. ALL THE MODEL SUITE (NAM/GFS/ECMWF/CMC) HAS COME INTO
AGREEMENT NOW SUN...WITH THE GFS JOINING THE OTHERS. STRONG 500HPA
SHORT WV EJECTS E FM OH VLY...ACROSS THE BAROCLINIC ZONE... AND
CLOUDS (DURING THE MORNING) AND WAA/OVERRUNNING RN (AFTN AND
EVENING) SPREAD QUICKLY NE BACK INTO THE REGION SUNDAY.
FORTUNATELY THIS SYSTEM IS FAST MOVING AND CYCLOGENISUS IS
MINIMAL...RAIN EXITS OVERNIGHT WITH MOST AREAS SUBJECT TO 6-12
HOURS OF RAIN SUN AFTN AND EVENING. WITH CLOUDS AND CAA TEMPS
WILL BE QUITE COOLER THAN THEY HAVE HAVE BEEN AND SVRL DEGREES
BLO NORMALS.
THERE WILL ALSO BE BRIEF PERIODS WHERE CONDS SUPPORT LK EFFECT
-SHRA AND SH-SN AT NIGHT OVER HIR TRRN TNGT AND SUN NIGHT...BUT
CHANGES IN FLOW AND WEAK FLOW WILL KEEP THIS CONFINED TO TUG HILL
AND LT.
AT 500HPA BROAD TROF OVER MID CONTINENT WILL RESULT IN SW FLOW
ACROSS FCA..AS SERIES OF SHORT WVS DIVE INTO TROF MOST ROTATING
WELL SOUTH OR NORTH OF REGION TILL WED. COLUMBUS DAY COOL HIGH
PRESSURE BUILDS FM OH VLY INTO NEW ENG. SOME WK LK RESPONSE MAY
LINGER INTO MONDAY MORNING IN N HERK/HAM COUNTIES...BUT WITH
SFC/LLVL FLOW BCMG LT AND SW...THIS WILL END.
SFC HI PRESSURE WILL REMAIN OVER THE RGN MON INTO WED MRNG. GEN
PC/CLEAR CONDS...SOME PATCHY CLOUDS IN MID LVL WAA N TIER..BUT A
FINE FALL PERIOD OF WX...NR NORMAL TEMPS...LT WINDS.
BY WED 500 TROF AXIS HAS SHIFTED E TO GRTLKS...AND SERIES OF SHORT
WVS DRIVES A CDFNT THRU FCA DURING LATE AFTN AND EVNG. THIS IS
ANOTHER ANNA TYPE EVENT LIKE TDY (SAT) WITH PD OF LT RAIN POST
FRONTAL.
MORNING LOWS MONDAY AND TUES UNDER CLEAR SKIES AND SFC HI W/12.5
PLUS HOURS OF NIGHT WILL HAVE NO PROBLEM FALLING INTO MID 20S TO
MID 30S. WOULD SUSPECT THIS TIME TOMORROW WE WILL BE CONSIDERING
FROST AND FREEZE FLAGS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
OTHER THAN MINOR TIMING DIFFERENCES ECMWF AND GFS IN REASONABLE
AGREEMENT. POPULATED WITH GMOS MAKING MINOR CHANGES. MID CONTINENT
500HPA TROF GRADUALLY SLIDES EASTWARD DURING THIS PERIOD AS A
500HPA RIDGE BUILDS IN ITS WAKE INTO THE GRTLKS TO END THE PERIOD.
THE PARADE OF SHORT WAVES CONTINUE TO MIGRATE AROUND THE BASE OF
THE TROF IN THE FAST FLOW. HIGH PRESSURE PASSES FM OH VLY TO MID
ATLC STATES THUR WITH GENERALLY FAIR CONDS. CLOUDS MAY INCR N AHEAD
OF NEXT SYSTEM THU AFTN AS PER GFS...BUT ECMWF KEEPS THIS MOISTURE
N OF RGN.
THE NEXT SHORT WV TO DRIVE A CDFNT THROUGH RGN IS FRI WITH WHAT
APPEARS TO BE YET ANOTHER ANNA TYPE CDFNT WITH PD OF LT RAIN IN ITS
WAKE. WITH TROF AXIS HAVING MOVED E TO OVER NY/NEW ENG FRI
NIGHT...CAA SURGE WILL BE STRONGER THE PVS FEW...WITH MINS IN 20S
TO LOW 30S MOST AREAS...AND WARMER READINGS CONFINED TO FAR SE.
WHERE THE GROWING SEASON IS STILL BARELY HANGING ON...IT SHOULD BE
OVER IN MOST AREAS BY THE WEEKEND. THE WEEKEND STARTS WITH ANOTHER
HIGH PRESSURE AREA IN THE FAST FLOW PASSING ACROSS RGN SAT. HWVR
THE PERIOD ENDS WITH 500HPA TROF EXITING...RIDGING IN ITS WAKE AND
WAA OVERSPREADING THE RGN FM THE WEST IN SPLIT FLOW.
TEMPS WILL REMAIN BLO NORMS FOR MOST OF THIS PERIOD. WHILE DRY AND
FAIR MUCH OF THE TIME A CDFNT WILL BRING A CHC OF -SHRA FRI AND
RAIN MAY OVERSPREAD THE REGION TO END THE WEEK.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH THE
END OF THE TAF PERIOD ENDING AT 06Z MONDAY. THE EXCEPTION WILL BE
AT KPOU WHERE VSBYS WILL BE MVFR/VFR WITH RAIN THIS AFTERNOON. FOR
THE REMAINDER OF TONIGHT SOME MID AND HIGH LEVEL CLOUDINESS WILL
MOVE INTO THE AREA AND THICKEN SUNDAY MORNING WITH BKN-OVC CONDITIONS.
SOME RAIN WILL MOVE INTO THE REGION FROM SOUTH TO NORTH DURING
THE AFTN/EVE HOURS. THE MODELS ARE NOT IN AGREEMENT YET WITH THE
EXACT TIMING AND PLACEMENT OF THIS RAIN...BUT IT/S POSSIBLE THAT
RAIN HOLDS OFF FOR KALB/KGFL UNTIL 00Z MONDAY. KPSF/KPOU HAVE A
BETTER CHC OF SEEING SOME LIGHT RAIN DURING THE AFTN OR EVENING
HOURS. FLYING CONDITIONS COULD DROP TO MVFR WITHIN ANY RAINFALL.
WESTERLY WINDS WILL CONTINUE TO BE RATHER LIGHT.
OUTLOOK...
SUN NT...VFR/MVFR. CHC/LIKELY -SHRA SUN EVENING.
MON-TUE NT...VFR. NO SIG WX.
WED...VFR. CHC MVFR IN SHOWERS.
THU...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE EXPECTED. A WAVE OF LOW
PRESSURE WILL MOVE ALONG THE FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING MOST AREAS OVER A QUARTER INCH OF RAIN SUNDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION ON MONDAY WITH FAIR AND COOL
WEATHER INTO WEDNESDAY WHEN ANOTHER FRONTAL SYSTEM WILL BRING A
PERIOD OF SHOWERS.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 7 DAYS.
AROUND A QUARTER INCH OF RAINFALL IS EXPECTED SUNDAY AFTERNOON/EVENING
AND WEDNESDAY AFTERNOON/EVENING. IN THE TUG HILL PLATEAU LAKE EFFECT
RAIN SHOWERS...AND OVER THE HIGHER TERRAIN AT NIGHT SNOW SHOWERS...WILL
PRODUCE UP TO AN INCH LIQUID TOTAL THIS WEEK. THESE AMOUNTS WILL
BE INSUFFICIENT TO PRODUCE MUCH RESPONSE IN RIVERS AND CREEKS THIS
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...FRUGIS/SNYDER
NEAR TERM...FRUGIS/KL
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...11/FRUIGIS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
105 AM EDT SUN OCT 7 2012
.SYNOPSIS...
MUCH COOLER AIR WILL CONTINUE TO STREAM INTO OUR REGION
OVERNIGHT AS WEAK HIGH PRESSURE CRESTS ACROSS THE REGION. LOW
PRESSURE WILL MOVE ALONG A FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING US MORE UNSETTLED WEATHER FOR SUNDAY AFTERNOON INTO
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE REGION ON MONDAY AND
BRING FAIR AND SEASONABLE WEATHER FOR THE FIRST HALF OF THE WORK
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM EDT...A BAND OF LAKE EFFECT RAIN SHOWERS HAS
DEVELOPED OFF LAKE ONTARIO. WHILE THE MAJORITY OF THESE RAIN
SHOWERS ARE REMAINING CLOSE TO THE LAKESHORE AND ACROSS THE TUG
HILL...A FEW SHOWERS WILL MAKE IT INTO THE FAR WESTERN
ADIRONDACKS. AS THE FLOW SHIFTS...THIS BAND WILL GRADUALLY SHIFT
SOUTH...POSSIBLY AFFECTING PARTS OF THE WESTERN MOHAWK VALLEY BY
LATE TONIGHT. THIS IS BEING MODELED WELL BY THE LATEST HRRR AND
LOCAL WRF.
MEANWHILE...A SFC FRONTAL BOUNDARY CONTINUES TO MOVE TO THE SOUTH
AND EAST OF OUR AREA ACROSS EASTERN NEW ENGLAND AND DOWN OFF THE
MID ATLANTIC SEABOARD. MID AND HIGH LEVEL CLOUDS ARE ALREADY
BEGINNING TO STREAK INTO THE REGION FROM THE SOUTHWEST...AND WILL
CONTINUE TO INCREASE TOWARD DAYBREAK AS A WAVE OF LOW PRESSURE
DEVELOPS ALONG THE FRONTAL BOUNDARY TO OUR SOUTH.
MIN TEMPS OVERNIGHT WILL BE MUCH COOLER THAN RECENT NIGHTS.
HOWEVER...DUE TO SOME WIND PERSISTING...AND THE PROSPECTS FOR
INCREASING CLOUDS...HAVE RAISED FORECAST MINS A BIT...WITH
LOWS GENERALLY FALLING INTO THE UPPER 30S TO LOWER 40S IN MOST AREAS
BY DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
WHILE SFC CDFNT WILL STALL WELL OFFSHORE...THE COLD AIR REMAINS
SHALLOW AND THE H850 BAROCLINIC ZN/THERMAL RIBBON ONLY MOVES JUST
OFFSHORE. ALL THE MODEL SUITE (NAM/GFS/ECMWF/CMC) HAS COME INTO
AGREEMENT NOW SUN...WITH THE GFS JOINING THE OTHERS. STRONG 500HPA
SHORT WV EJECTS E FM OH VLY...ACROSS THE BAROCLINIC ZONE... AND
CLOUDS (DURING THE MORNING) AND WAA/OVERRUNNING RN (AFTN AND
EVENING) SPREAD QUICKLY NE BACK INTO THE REGION SUNDAY.
FORTUNATELY THIS SYSTEM IS FAST MOVING AND CYCLOGENISUS IS
MINIMAL...RAIN EXITS OVERNIGHT WITH MOST AREAS SUBJECT TO 6-12
HOURS OF RAIN SUN AFTN AND EVENING. WITH CLOUDS AND CAA TEMPS
WILL BE QUITE COOLER THAN THEY HAVE HAVE BEEN AND SVRL DEGREES
BLO NORMALS.
THERE WILL ALSO BE BRIEF PERIODS WHERE CONDS SUPPORT LK EFFECT
-SHRA AND SH-SN AT NIGHT OVER HIR TRRN TNGT AND SUN NIGHT...BUT
CHANGES IN FLOW AND WEAK FLOW WILL KEEP THIS CONFINED TO TUG HILL
AND LT.
AT 500HPA BROAD TROF OVER MID CONTINENT WILL RESULT IN SW FLOW
ACROSS FCA..AS SERIES OF SHORT WVS DIVE INTO TROF MOST ROTATING
WELL SOUTH OR NORTH OF REGION TILL WED. COLUMBUS DAY COOL HIGH
PRESSURE BUILDS FM OH VLY INTO NEW ENG. SOME WK LK RESPONSE MAY
LINGER INTO MONDAY MORNING IN N HERK/HAM COUNTIES...BUT WITH
SFC/LLVL FLOW BCMG LT AND SW...THIS WILL END.
SFC HI PRESSURE WILL REMAIN OVER THE RGN MON INTO WED MRNG. GEN
PC/CLEAR CONDS...SOME PATCHY CLOUDS IN MID LVL WAA N TIER..BUT A
FINE FALL PERIOD OF WX...NR NORMAL TEMPS...LT WINDS.
BY WED 500 TROF AXIS HAS SHIFTED E TO GRTLKS...AND SERIES OF SHORT
WVS DRIVES A CDFNT THRU FCA DURING LATE AFTN AND EVNG. THIS IS
ANOTHER ANNA TYPE EVENT LIKE TDY (SAT) WITH PD OF LT RAIN POST
FRONTAL.
MORNING LOWS MONDAY AND TUES UNDER CLEAR SKIES AND SFC HI W/12.5
PLUS HOURS OF NIGHT WILL HAVE NO PROBLEM FALLING INTO MID 20S TO
MID 30S. WOULD SUSPECT THIS TIME TOMORROW WE WILL BE CONSIDERING
FROST AND FREEZE FLAGS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
OTHER THAN MINOR TIMING DIFFERENCES ECMWF AND GFS IN REASONABLE
AGREEMENT. POPULATED WITH GMOS MAKING MINOR CHANGES. MID CONTINENT
500HPA TROF GRADUALLY SLIDES EASTWARD DURING THIS PERIOD AS A
500HPA RIDGE BUILDS IN ITS WAKE INTO THE GRTLKS TO END THE PERIOD.
THE PARADE OF SHORT WAVES CONTINUE TO MIGRATE AROUND THE BASE OF
THE TROF IN THE FAST FLOW. HIGH PRESSURE PASSES FM OH VLY TO MID
ATLC STATES THUR WITH GENERALLY FAIR CONDS. CLOUDS MAY INCR N AHEAD
OF NEXT SYSTEM THU AFTN AS PER GFS...BUT ECMWF KEEPS THIS MOISTURE
N OF RGN.
THE NEXT SHORT WV TO DRIVE A CDFNT THROUGH RGN IS FRI WITH WHAT
APPEARS TO BE YET ANOTHER ANNA TYPE CDFNT WITH PD OF LT RAIN IN ITS
WAKE. WITH TROF AXIS HAVING MOVED E TO OVER NY/NEW ENG FRI
NIGHT...CAA SURGE WILL BE STRONGER THE PVS FEW...WITH MINS IN 20S
TO LOW 30S MOST AREAS...AND WARMER READINGS CONFINED TO FAR SE.
WHERE THE GROWING SEASON IS STILL BARELY HANGING ON...IT SHOULD BE
OVER IN MOST AREAS BY THE WEEKEND. THE WEEKEND STARTS WITH ANOTHER
HIGH PRESSURE AREA IN THE FAST FLOW PASSING ACROSS RGN SAT. HWVR
THE PERIOD ENDS WITH 500HPA TROF EXITING...RIDGING IN ITS WAKE AND
WAA OVERSPREADING THE RGN FM THE WEST IN SPLIT FLOW.
TEMPS WILL REMAIN BLO NORMS FOR MOST OF THIS PERIOD. WHILE DRY AND
FAIR MUCH OF THE TIME A CDFNT WILL BRING A CHC OF -SHRA FRI AND
RAIN MAY OVERSPREAD THE REGION TO END THE WEEK.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR FLYING CONDITIONS ARE EXPECTED THROUGH MUCH OF THE OVERNIGHT
HOURS WITH JUST FEW-SCT STRATOCU CLOUDS AROUND 4-6 KFT...MAINLY
DURING THE EVENING HOURS. SOME MID AND HIGH LEVEL CLOUDINESS WILL
MOVE INTO THE AREA TOWARDS DAYBREAK. LIGHT WESTERLY WINDS WILL BE IN
PLACE TONIGHT...AND WITH DEWPOINTS DROPPING DOWN INTO THE 30S...NO
RADIATIONAL FOG IS EXPECTED TO DEVELOP TONIGHT.
BKN-OVC MID LEVEL CLOUDINESS WILL BE IN PLACE FOR SUNDAY MORNING. SOME
RAIN WILL MOVE INTO THE REGION FROM SOUTH TO NORTH DURING THE
AFTN/EVE HOURS. THE MODELS ARE NOT IN AGREEMENT YET WITH THE EXACT
TIMING AND PLACEMENT OF THIS RAIN...BUT IT/S POSSIBLE THAT RAIN HOLDS
OFF FOR KALB/KGFL UNTIL 00Z MONDAY. KPSF/KPOU HAVE A BETTER CHC OF
SEEING SOME LIGHT RAIN DURING THE AFTN OR EVENING HOURS. FLYING
CONDITIONS COULD DROP TO MVFR WITHIN ANY RAINFALL. WESTERLY WINDS
WILL CONTINUE TO BE RATHER LIGHT.
OUTLOOK...
SUN NT...VFR/MVFR. CHC/LIKELY -SHRA SUN EVENING.
MON-TUE NT...VFR. NO SIG WX.
WED...VFR. CHC MVFR IN SHOWERS.
THU...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE EXPECTED. A WAVE OF LOW
PRESSURE WILL MOVE ALONG THE FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING MOST AREAS OVER A QUARTER INCH OF RAIN SUNDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION ON MONDAY WITH FAIR AND COOL
WEATHER INTO WEDNESDAY WHEN ANOTHER FRONTAL SYSTEM WILL BRING A
PERIOD OF SHOWERS.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 7 DAYS.
AROUND A QUARTER INCH OF RAINFALL IS EXPECTED SUNDAY AFTERNOON/EVENING
AND WEDNESDAY AFTERNOON/EVENING. IN THE TUG HILL PLATEAU LAKE EFFECT
RAIN SHOWERS...AND OVER THE HIGHER TERRAIN AT NIGHT SNOW SHOWERS...WILL
PRODUCE UP TO AN INCH LIQUID TOTAL THIS WEEK. THESE AMOUNTS WILL
BE INSUFFICIENT TO PRODUCE MUCH RESPONSE IN RIVERS AND CREEKS THIS
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...FRUGIS/SNYDER
NEAR TERM...KL/FRUGIS
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...FRUGIS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS MIAMI FL
127 PM EDT SUN OCT 7 2012
.AVIATION...
DEEP MOISTURE...LIGHT WINDS...AND UNSTABLE CONDITIONS ACROSS THE
REGION WILL LEAD TO SCATTERED THUNDERSTORMS DEVELOPING AREAWIDE.
STORMS WILL BE SLOW MOVING. MVFR CONDITIONS WILL BE POSSIBLE IN
AND AROUND THUNDERSTORMS. A GULF COAST SEA BREEZE IS EXPECTED TO
DEVELOP BY 19Z AT KAPF...WITH A NW FLOW. LIGHT WINDS ARE EXPECTED
OVERNIGHT...AND SHOWERS MAY BE POSSIBLE NEAR THE EAST COAST TAF
SITES AROUND DAYBREAK.
&&
.PREV DISCUSSION... /ISSUED 921 AM EDT SUN OCT 7 2012/
UPDATE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE ATLANTIC
WATERS MAKING THEIR WAY ONSHORE THE SOUTHEAST FLORIDA COAST THIS
MORNING. WATERSPOUTS ARE POSSIBLE WITH SOME OF THESE
SHOWERS...SIMILAR TO YESTERDAY...AND WILL CONTINUE TO MENTION THIS
IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY.
MORNING SOUNDING FROM MIAMI SHOWS LITTLE CHANGE FROM YESTERDAY
WITH LOTS OF MOISTURE. THE SOUNDING FROM KEY WEST, HOWEVER, SHOWS A
SUBTLE DRIER LAYER FROM 850 MB TO 700 MB. SHORT RANGE MODELS
INCLUDING THE HRRR AREN`T SHOWING AS MUCH CONVECTION OVER THE
SOUTHERN PENINSULA THIS AFTERNOON COMPARED TO PAST COUPLE OF DAYS.
GLOBAL MODELS (GFS AND ECMWF) SHOW A WEAK MID-LEVEL SHORTWAVE
PASSING THROUGH SOUTH FLORIDA THIS MORNING (POTENTIALLY
CONTRIBUTING TO INCREASED ATLANTIC AND COASTAL CONVECTION THIS MORNING) AND
OVER THE ATLANTIC THIS AFTERNOON. THE DRIER AIR OBSERVED AT KEY
WEST MAY BE AN INDICATION OF SUBSIDENCE BEHIND THE SHORTWAVE AND
MODELS COULD BE PICKING UP ON THIS.
HAVING SAID ALL THIS, STILL EXPECT AT LEAST SCATTERED
SHOWERS/TSTMS OVER INTERIOR AREAS THIS AFTERNOON WITH SLOW
MOVEMENT OF CELLS LEADING TO LOCALLY HIGH RAINFALL AMOUNTS.
HOWEVER, WOULD NOT BE SURPRISED TO SEE LESS ACTIVITY THIS
AFTERNOON AS PER MODEL TRENDS INDICATED ABOVE.
MOLLEDA
PREV DISCUSSION... /ISSUED 727 AM EDT SUN OCT 7 2012/
AVIATION...
CIRRUS CLOUDS COVER MUCH OF THE REGION THIS MORNING...FROM
CONVECTION LAST NIGHT. LIGHT WINDS THIS MORNING WILL BECOME
EASTERLY WITH DIURNAL HEATING LATER TODAY. A WEST COAST SEA BREEZE
IS ALSO EXPECTED TO BECOME ESTABLISHED BY EARLY AFTERNOON. THIS
WILL SET THE STAGE AGAIN FOR SCT TSRAS ACROSS MUCH OF THE SOUTH
FLORIDA AREA...ESPECIALLY ACROSS INTERIOR AREAS. ACTIVITY SHOULD
DIMINISH SHORTLY AFTER NIGHTFALL.
PREV DISCUSSION... /ISSUED 255 AM EDT SUN OCT 7 2012/
SHORT TERM (TODAY-TUESDAY)...
THE LATEST SURFACE ANALYSIS EARLIER THIS MORNING SHOWED A COLD FRONT
EXTENDING SOUTHWEST FROM THE CAROLINAS TO THE CENTRAL GULF COAST
STATES AND WEAK HIGH PRESSURE CENTERED NORTHEAST OF THE LOCAL AREA
OFF THE NERN FLORIDA COAST ACROSS THE WESTERN ATLANTIC. MOIST
EASTERLY LOW-LEVEL FLOW SOUTH OF THIS HIGH WILL PERSIST OVER THE
AREA INTO MONDAY AS THE COLD FRONT GRADUALLY CONTINUES SOUTHEASTWARD
INTO THE STATE AND HIGH PRESSURE BUILDS ACROSS THE REGION IN ITS
WAKE. RECENTLY ANIMATED WATER VAPOR LOOP SHOWED BROAD CYCLONIC FLOW
ACROSS THE MID-SECTION AND EASTERN HALF OF THE COUNTRY CHARACTERIZED
WITH A FAIRLY STRONG SHORTWAVE TROUGH DIGGING SOUTHEAST AND EAST
ACROSS THE PLAINS. MID TO UPPER SW FLOW ALONG WITH PLENTY OF
MID/UPPER MOISTURE AHEAD OF THIS UPPER TROUGH CONTINUES TO STREAM
OVERHEAD. MODEL SOUNDING PROFILES REMAIN FAIRLY WET ACROSS THE
LOCAL AREA THROUGH THE BULK OF THIS SHORT-TERM PERIOD WITH PW`S
REMAINING AROUND THE 2" INCH MARK. ONE MAIN DIFFERENCE OR TREND
NOTED FROM RUN TO RUN WITHIN THE MODELS HAS BEEN THE DECREASE IN
SOUTHWARD PROGRESSION OF THE FRONTAL BOUNDARY INTO OUR LOCAL AREA
OVER THE NEXT COUPLE OF DAYS. THE LATEST MODEL CYCLE INDICATES
THE BOUNDARY STALLING OVER CENTRAL FLORIDA SOMETIME BETWEEN MONDAY
EVENING AND TUESDAY...WHEREAS BEFORE...ALL INDICATIONS INDICATED
THE BOUNDARY PROGRESSING INTO THE AREA WITH DRIER AIR FILTERING IN
BEHIND IT. THIS WILL RESULT IN THE RAIN CHANCES REMAINING IN THE
FORECAST THROUGH THIS PERIOD WITH THE BEST POTENTIAL FOR THE DRIER
AIR LATER THROUGH THE MID/LATTER HALF OF THE WEEK. THE LATEST WRF
MODEL REFLECTIVITIES SUPPORT THIS AND GENERALLY INDICATE THE BULK
OF THE ACTIVITY SETTING UP OVER THE INTERIOR AND GULF COAST
REGIONS THROUGH THE AFTERNOON AND EVENING PERIODS.
HOWEVER...SIMILAR TO YESTERDAY...SCATTERED SHOWERS AND STORMS
DEVELOPING AND SPREADING WEST ACROSS THE EASTERN HALF OF THE AREA
WILL REMAIN POSSIBLE THROUGH THE FIRST HALF OF THE DAY TODAY. THE
LATEST MODEL GUIDANCE INDICATES AN ADDITIONAL HALF OF AN INCH TO
AN INCH ACROSS THE WESTERN HALF OF THE AREA OVER THE UPCOMING FEW
DAYS...WHICH LINES UP WELL WITH THE LATEST HPC GUIDANCE. LOCALLY
HIGHER AMOUNTS WILL REMAIN POSSIBLE WHERE THE ACTIVITY BECOMES
CONCENTRATED THROUGH THIS TIME. AS A RESULT...THE MAIN CONCERNS
WILL BE THE POTENTIAL FOR LOCALIZED FLOODING AND WET
MICROBURSTS/GUSTY WINDS IN AND AROUND THE HEAVIER ACTIVITY OR
STRONG STORMS THAT DEVELOP.
LONG TERM...(TUESDAY NIGHT-SATURDAY)
THE LATEST GFS/GFS ENSEMBLE AND ECMWF REMAIN IN DECENT AGREEMENT ON
THE LARGE SCALE THROUGH THE MID-WEEK PERIOD AND GENERALLY KEEP THE
BROAD CYCLONE FLOW IN PLACE ACROSS THE EASTERN STATES. HOWEVER...ALL
CONTINUE TO SUGGEST MUCH DRIER DEEP LAYER AIR SPREADING SOUTH AS
THE PREVIOUSLY DISCUSSED FRONTAL BOUNDARY STALLS AND DIMINISHES
AND THE MEAN UPPER TROUGH AXIS SHIFTS EWD. THIS DRY AIR WILL
TRANSLATE TO A SLIGHT DECREASE IN DEWPOINTS...POSSIBLY INTO THE
UPPER 60S INLAND AND NORTH AROUND THE LAKE REGION. WILL REFLECT
THIS WITH DECREASING RAINFALL CHANCES THROUGH THIS TIME ACROSS THE
AREA. NO NOTABLE CHANGES REGARDING THE DAILY HIGH AND LOW
TEMPERATURES THROUGH THIS EXTENDED PERIOD.
MARINE...
LIGHT EASTERLY FLOW WILL PERSIST INTO THE UPCOMING WEEK AS A
WEAKENING FRONTAL BOUNDARY APPROACHES FROM THE NORTH AND NORTHWEST.
SCATTERED SHOWERS AND STORMS WILL REMAIN IN THE FORECAST THROUGH
THIS TIME. DRIER AIR WITH LIGHT TO MODERATE NORTHEAST WINDS WILL
BECOME A POSSIBILITY THROUGH THE MIDDLE PART OF THE UPCOMING WEEK.
SEAS WILL RESPOND AND INCREASE INTO THE 3 TO 5 FOOT RANGE ACROSS THE
ATLANTIC WATERS.
FIRE WEATHER...
DESPITE THE DRIER AIR PROGGED TO FILTER INTO THE AREA FROM NORTH TO
SOUTH NEXT WEEK...RELATIVE HUMIDITIES ARE FORECAST TO REMAIN WELL
ABOVE CRITICAL LEVELS WITH NO RED FLAG CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 88 78 89 / 30 40 30 30
FORT LAUDERDALE 79 88 77 88 / 30 40 30 30
MIAMI 78 89 77 89 / 30 40 30 30
NAPLES 75 90 75 89 / 30 40 30 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...59/RM
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
921 AM EDT SUN OCT 7 2012
.UPDATE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE ATLANTIC
WATERS MAKING THEIR WAY ONSHORE THE SOUTHEAST FLORIDA COAST THIS
MORNING. WATERSPOUTS ARE POSSIBLE WITH SOME OF THESE
SHOWERS...SIMILAR TO YESTERDAY...AND WILL CONTINUE TO MENTION THIS
IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY.
MORNING SOUNDING FROM MIAMI SHOWS LITTLE CHANGE FROM YESTERDAY
WITH LOTS OF MOISTURE. THE SOUNDING FROM KEY WEST, HOWEVER, SHOWS A
SUBTLE DRIER LAYER FROM 850 MB TO 700 MB. SHORT RANGE MODELS
INCLUDING THE HRRR AREN`T SHOWING AS MUCH CONVECTION OVER THE
SOUTHERN PENINSULA THIS AFTERNOON COMPARED TO PAST COUPLE OF DAYS.
GLOBAL MODELS (GFS AND ECMWF) SHOW A WEAK MID-LEVEL SHORTWAVE
PASSING THROUGH SOUTH FLORIDA THIS MORNING (POTENTIALLY
CONTRIBUTING TO INCREASED ATLANTIC AND COASTAL CONVECTION THIS MORNING) AND
OVER THE ATLANTIC THIS AFTERNOON. THE DRIER AIR OBSERVED AT KEY
WEST MAY BE AN INDICATION OF SUBSIDENCE BEHIND THE SHORTWAVE AND
MODELS COULD BE PICKING UP ON THIS.
HAVING SAID ALL THIS, STILL EXPECT AT LEAST SCATTERED
SHOWERS/TSTMS OVER INTERIOR AREAS THIS AFTERNOON WITH SLOW
MOVEMENT OF CELLS LEADING TO LOCALLY HIGH RAINFALL AMOUNTS.
HOWEVER, WOULD NOT BE SURPRISED TO SEE LESS ACTIVITY THIS
AFTERNOON AS PER MODEL TRENDS INDICATED ABOVE.
MOLLEDA
&&
.PREV DISCUSSION... /ISSUED 727 AM EDT SUN OCT 7 2012/
AVIATION...
CIRRUS CLOUDS COVER MUCH OF THE REGION THIS MORNING...FROM
CONVECTION LAST NIGHT. LIGHT WINDS THIS MORNING WILL BECOME
EASTERLY WITH DIURNAL HEATING LATER TODAY. A WEST COAST SEA BREEZE
IS ALSO EXPECTED TO BECOME ESTABLISHED BY EARLY AFTERNOON. THIS
WILL SET THE STAGE AGAIN FOR SCT TSRAS ACROSS MUCH OF THE SOUTH
FLORIDA AREA...ESPECIALLY ACROSS INTERIOR AREAS. ACTIVITY SHOULD
DIMINISH SHORTLY AFTER NIGHTFALL.
PREV DISCUSSION... /ISSUED 255 AM EDT SUN OCT 7 2012/
SHORT TERM (TODAY-TUESDAY)...
THE LATEST SURFACE ANALYSIS EARLIER THIS MORNING SHOWED A COLD FRONT
EXTENDING SOUTHWEST FROM THE CAROLINAS TO THE CENTRAL GULF COAST
STATES AND WEAK HIGH PRESSURE CENTERED NORTHEAST OF THE LOCAL AREA
OFF THE NERN FLORIDA COAST ACROSS THE WESTERN ATLANTIC. MOIST
EASTERLY LOW-LEVEL FLOW SOUTH OF THIS HIGH WILL PERSIST OVER THE
AREA INTO MONDAY AS THE COLD FRONT GRADUALLY CONTINUES SOUTHEASTWARD
INTO THE STATE AND HIGH PRESSURE BUILDS ACROSS THE REGION IN ITS
WAKE. RECENTLY ANIMATED WATER VAPOR LOOP SHOWED BROAD CYCLONIC FLOW
ACROSS THE MID-SECTION AND EASTERN HALF OF THE COUNTRY CHARACTERIZED
WITH A FAIRLY STRONG SHORTWAVE TROUGH DIGGING SOUTHEAST AND EAST
ACROSS THE PLAINS. MID TO UPPER SW FLOW ALONG WITH PLENTY OF
MID/UPPER MOISTURE AHEAD OF THIS UPPER TROUGH CONTINUES TO STREAM
OVERHEAD. MODEL SOUNDING PROFILES REMAIN FAIRLY WET ACROSS THE
LOCAL AREA THROUGH THE BULK OF THIS SHORT-TERM PERIOD WITH PW`S
REMAINING AROUND THE 2" INCH MARK. ONE MAIN DIFFERENCE OR TREND
NOTED FROM RUN TO RUN WITHIN THE MODELS HAS BEEN THE DECREASE IN
SOUTHWARD PROGRESSION OF THE FRONTAL BOUNDARY INTO OUR LOCAL AREA
OVER THE NEXT COUPLE OF DAYS. THE LATEST MODEL CYCLE INDICATES
THE BOUNDARY STALLING OVER CENTRAL FLORIDA SOMETIME BETWEEN MONDAY
EVENING AND TUESDAY...WHEREAS BEFORE...ALL INDICATIONS INDICATED
THE BOUNDARY PROGRESSING INTO THE AREA WITH DRIER AIR FILTERING IN
BEHIND IT. THIS WILL RESULT IN THE RAIN CHANCES REMAINING IN THE
FORECAST THROUGH THIS PERIOD WITH THE BEST POTENTIAL FOR THE DRIER
AIR LATER THROUGH THE MID/LATTER HALF OF THE WEEK. THE LATEST WRF
MODEL REFLECTIVITIES SUPPORT THIS AND GENERALLY INDICATE THE BULK
OF THE ACTIVITY SETTING UP OVER THE INTERIOR AND GULF COAST
REGIONS THROUGH THE AFTERNOON AND EVENING PERIODS.
HOWEVER...SIMILAR TO YESTERDAY...SCATTERED SHOWERS AND STORMS
DEVELOPING AND SPREADING WEST ACROSS THE EASTERN HALF OF THE AREA
WILL REMAIN POSSIBLE THROUGH THE FIRST HALF OF THE DAY TODAY. THE
LATEST MODEL GUIDANCE INDICATES AN ADDITIONAL HALF OF AN INCH TO
AN INCH ACROSS THE WESTERN HALF OF THE AREA OVER THE UPCOMING FEW
DAYS...WHICH LINES UP WELL WITH THE LATEST HPC GUIDANCE. LOCALLY
HIGHER AMOUNTS WILL REMAIN POSSIBLE WHERE THE ACTIVITY BECOMES
CONCENTRATED THROUGH THIS TIME. AS A RESULT...THE MAIN CONCERNS
WILL BE THE POTENTIAL FOR LOCALIZED FLOODING AND WET
MICROBURSTS/GUSTY WINDS IN AND AROUND THE HEAVIER ACTIVITY OR
STRONG STORMS THAT DEVELOP.
LONG TERM...(TUESDAY NIGHT-SATURDAY)
THE LATEST GFS/GFS ENSEMBLE AND ECMWF REMAIN IN DECENT AGREEMENT ON
THE LARGE SCALE THROUGH THE MID-WEEK PERIOD AND GENERALLY KEEP THE
BROAD CYCLONE FLOW IN PLACE ACROSS THE EASTERN STATES. HOWEVER...ALL
CONTINUE TO SUGGEST MUCH DRIER DEEP LAYER AIR SPREADING SOUTH AS
THE PREVIOUSLY DISCUSSED FRONTAL BOUNDARY STALLS AND DIMINISHES
AND THE MEAN UPPER TROUGH AXIS SHIFTS EWD. THIS DRY AIR WILL
TRANSLATE TO A SLIGHT DECREASE IN DEWPOINTS...POSSIBLY INTO THE
UPPER 60S INLAND AND NORTH AROUND THE LAKE REGION. WILL REFLECT
THIS WITH DECREASING RAINFALL CHANCES THROUGH THIS TIME ACROSS THE
AREA. NO NOTABLE CHANGES REGARDING THE DAILY HIGH AND LOW
TEMPERATURES THROUGH THIS EXTENDED PERIOD.
MARINE...
LIGHT EASTERLY FLOW WILL PERSIST INTO THE UPCOMING WEEK AS A
WEAKENING FRONTAL BOUNDARY APPROACHES FROM THE NORTH AND NORTHWEST.
SCATTERED SHOWERS AND STORMS WILL REMAIN IN THE FORECAST THROUGH
THIS TIME. DRIER AIR WITH LIGHT TO MODERATE NORTHEAST WINDS WILL
BECOME A POSSIBILITY THROUGH THE MIDDLE PART OF THE UPCOMING WEEK.
SEAS WILL RESPOND AND INCREASE INTO THE 3 TO 5 FOOT RANGE ACROSS THE
ATLANTIC WATERS.
FIRE WEATHER...
DESPITE THE DRIER AIR PROGGED TO FILTER INTO THE AREA FROM NORTH TO
SOUTH NEXT WEEK...RELATIVE HUMIDITIES ARE FORECAST TO REMAIN WELL
ABOVE CRITICAL LEVELS WITH NO RED FLAG CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 88 78 / 40 30 40 30
FORT LAUDERDALE 85 79 88 77 / 40 30 40 30
MIAMI 88 78 89 77 / 40 30 40 30
NAPLES 88 75 90 75 / 40 30 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
300 PM CDT SUN OCT 7 2012
.DISCUSSION...
ISSUED 300 PM CDT SUN OCT 7 2012
A CHILLY DAY CONTINUES TO UNFOLD ACROSS CENTRAL AND SOUTHEAST
ILLINOIS THIS AFTERNOON...SOON TO BE FOLLOWED BY ONE MORE CHILLY
NIGHT...AS COOL HIGH PRESSURE SETTLES SOUTHEAST ACROSS THE REGION.
ASIDE FROM HOW COLD IT WILL GET TONIGHT...ALONG WITH ANY
FROST/FREEZE POTENTIAL...PRIMARY FORECAST CONCERN TODAY REVOLVES
AROUND PRECIPITATION CHANCES TUESDAY NIGHT AND THURSDAY NIGHT WITH
TWO COLD FRONTAL PASSAGES...AS WELL AS HEADING INTO THE WEEKEND WITH
A MORE VIGOROUS WEATHER SYSTEM.
12Z MODELS REMAIN IN SURPRISINGLY GOOD AGREEMENT FOR MUCH OF THE
WEEK. THEIR AGREEMENT AND RUN-TO-RUN CONSISTENCY HAS BEEN GOOD FOR
MOST OF THE FORECAST PERIOD. HOWEVER...THERE REMAINS SOME
TIMING/STRENGTH DIFFERENCES AND FLIP-FLOPPING WITH THE ARRIVAL UPPER
LOW REMNANTS FROM THE REX BLOCK OFF THE PACIFIC COAST. A ENSEMBLE
MEAN SOLUTION SHOULD CONTINUE TO BE THE BEST OPTION FOR NOW.
SHORT TERM...TONIGHT THROUGH WEDNESDAY...FOR THE FIRST TIME IN A
COUPLE NIGHTS...UNCERTAINTIES WITH CLOUD COVER WILL NOT COMPLICATE
THE OVERNIGHT LOW TEMPERATURE FORECAST. HOWEVER...THE SURFACE RIDGE
AXIS WILL BE SLIDING SOUTHEAST ACROSS THE AREA TONIGHT...WITH WINDS
TURNING SOUTHERLY IN ITS WAKE. THIS SCENARIO SHOULD PRECLUDE
WIDESPREAD FROST/FREEZING CONDITIONS IN THE WESTERN PORTION OF THE
FORECAST AREA. IT WILL BE A CLOSER CALL IN THE EAST WHERE WINDS
WILL BE SLOWER TO TURN SOUTHERLY. SO...HAVE OPTED TO GO WITH A
FROST ADVISORY IN THIS AREA...ALTHOUGH BRIEF/LOCAL FREEZING
CONDITIONS CAN NOT BE RULED OUT.
DEEP SOUTHERLY FLOW WILL GRADUALLY DEVELOP MONDAY INTO TUESDAY AS
THE SURFACE HIGH DRIFTS FURTHER TO THE EAST AND AN UPPER WAVE
DIGGING INTO THE PLAINS HELPS INITIATE DOWNSTREAM RIDGING. THIS
SCENARIO IS SUPPORTIVE OF SLOWLY MODERATING TEMPERATURES...WITH
TEMPERATURES AT OR ABOVE NORMAL BY TUESDAY. THE PATTERN IS ALSO
CONDUCIVE TO DEEP DIURNAL MIXING AND GUSTY WINDS SHOULD DEVELOP
DAILY MONDAY AND TUESDAY.
THE DIGGING WAVE WILL PUSH A FRONTAL BOUNDARY THROUGH THE AREA
TUESDAY NIGHT...ACCOMPANIED BY PRIMARILY POST FRONTAL SHOWERS. THERE
IS GOOD ISENTROPIC ASCENT AHEAD OF THE FRONT...BUT CONDENSATION
PRESSURE DEFICITS SUGGEST THE PRE-FRONTAL AIRMASS WILL BE FAR TOO
DRY TO SUPPORT PRECIPITATION. THERE IS DECENT COUPLED JET FORCING
AND MID-LEVEL FRONTOGENESIS BEHIND THE FRONT AS THE UPPER WAVE MOVES
THROUGH...BUT EXPECTED MOISTURE AVAILABILITY PRECLUDES ME FROM GOING
ABOVE CHANCE POPS AT THIS TIME.
ANOTHER BRIEF SHOT OF QUIET/COOLER WEATHER IS ANTICIPATED BEHIND THE
FRONT FOR WEDNESDAY.
LONG TERM...THURSDAY THROUGH SUNDAY...SOUTHERLY LOW LEVEL FLOW AND
RISING HEIGHTS SIGNAL A RETURN TO MORE SEASONABLE TEMPERATURES FOR
THURSDAY...BEFORE A MOSTLY DRY FRONTAL PASSAGE COOLS THINGS DOWN A
BIT FOR FRIDAY. THEN...ATTENTION TURNS TO THE REMNANTS OF THE UPPER
LOW OFF THE PACIFIC COAST. CONFIDENCE IS GROWING THAT THIS SYSTEM
WILL USHER IN A PERIOD OF WARMER WEATHER...ALONG WITH
SHOWERS/STORMS...AS IT MOVES THROUGH. AS MENTIONED ABOVE...DUE TO
THE REMAINING UNCERTAINTIES REVOLVING AROUND THIS SYSTEM/S
ULTIMATE ARRIVAL...HAVE KEPT POPS IN THE CHANCE CATEGORY.
BAK
&&
.AVIATION...
ISSUED 1208 PM CDT SUN OCT 7 2012
RAPID DIURNAL CLOUD DEVELOPMENT AT 5000 FEET OCCURRED AROUND
15Z...WITH BROKEN CEILINGS NOW WIDESPREAD OVER THE TAF SITES.
ALREADY STARTING TO SEE SOME THINNING OF THE CLOUDS WEST OF
KPIA/KSPI...AND CU-RULE OFF THE RAP MODEL SHOWS CONTINUED
DIMINISHING OF THE CLOUDS FROM WEST TO EAST. BY 00Z...THE
REMAINING CLOUDS SHOULD LARGELY BE SOUTHEAST OF THE TAF SITES.
OVERNIGHT...WEST WINDS WILL GRADUALLY TREND TOWARD THE SOUTHWEST
AND SOUTH AS HIGH PRESSURE PASSES TO OUR SOUTH. WHILE SKIES REMAIN
CLEAR INTO MONDAY...A TIGHTENING PRESSURE GRADIENT WILL LEAD TO
SOME GUSTY SOUTHWEST WINDS BY LATE MORNING...WITH SOME GUSTS ABOVE
15 KNOTS AT MOST SITES.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 8 AM CDT MONDAY FOR ILZ038-042>046-
051>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1209 PM CDT SUN OCT 7 2012
.DISCUSSION...
ISSUED 1003 AM CDT SUN OCT 7 2012
HIGH PRESSURE WAS CENTERED OVER EASTERN KANSAS LATE THIS
MORNING...RIDGING NORTHEAST INTO WISCONSIN. RAPID CLEARING HAS
BEEN TAKING PLACE OVER MOST OF THE CWA THE LAST COUPLE HOURS...
WITH AREAS FROM ABOUT I-74 NORTHWARD STILL MOSTLY CLOUDY BUT
RAPIDLY CLEARING. SUBSIDENCE FROM THE HIGH SHOULD KEEP SKIES
MOSTLY SUNNY THROUGH THE AFTERNOON...WITH CU-RULE OFF THE NAM AND
RAP MODELS STILL SHOWING SOME DIURNAL DEVELOPMENT ACROSS THE
EASTERN CWA FOR A COUPLE HOURS AROUND MIDDAY.
HAVE SENT SOME UPDATED ZONES/GRIDS TO REFLECT THE SKY TRENDS.
TEMPERATURES LOOKED FAIRLY GOOD AND NO CHANGES MADE TO THE HIGHS.
GEELHART
&&
.AVIATION...
ISSUED 1208 PM CDT SUN OCT 7 2012
RAPID DIURNAL CLOUD DEVELOPMENT AT 5000 FEET OCCURRED AROUND
15Z...WITH BROKEN CEILINGS NOW WIDESPREAD OVER THE TAF SITES.
ALREADY STARTING TO SEE SOME THINNING OF THE CLOUDS WEST OF
KPIA/KSPI...AND CU-RULE OFF THE RAP MODEL SHOWS CONTINUED
DIMINISHING OF THE CLOUDS FROM WEST TO EAST. BY 00Z...THE
REMAINING CLOUDS SHOULD LARGELY BE SOUTHEAST OF THE TAF SITES.
OVERNIGHT...WEST WINDS WILL GRADUALLY TREND TOWARD THE SOUTHWEST
AND SOUTH AS HIGH PRESSURE PASSES TO OUR SOUTH. WHILE SKIES REMAIN
CLEAR INTO MONDAY...A TIGHTENING PRESSURE GRADIENT WILL LEAD TO
SOME GUSTY SOUTHWEST WINDS BY LATE MORNING...WITH SOME GUSTS ABOVE
15 KNOTS AT MOST SITES.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 326 AM CDT SUN OCT 7 2012
THE COLDEST AIR WE WILL SEE WITH THIS AIRMASS WILL MAKE ITS
FARTHEST SOUTHWARD PROGRESSION INTO CENTRAL ILLINOIS THIS MORNING
BETWEEN 12Z AND 18Z...THEN MID LEVEL WARMING WILL DEVELOP AND
CONTINUE UNTIL THE NEXT COLD FRONT ARRIVES TUESDAY NIGHT. WE WILL
HAVE MUCH CLEARER SKIES SUNDAY NIGHT...SO EVEN THOUGH THE COLDEST
AIR WILL HAVE MOVED EAST OF ILLINOIS...FROST/FREEZE POTENTIAL WILL
RETURN FOR AREAS MAINLY EAST OF I-57. THE NEXT RAIN CHANCES WILL
COME WITH COLD FRONTAL PASSAGES ON TUESDAY NIGHT AND THURSDAY
NIGHT...THEN AGAIN WITH A MORE LARGE SCALE LOW PROJECTED TO ARRIVE
EARLY NEXT WEEKEND.
THE OVERALL MODEL GUIDANCE REMAINS IN RELATIVE AGREEMENT ON TIMING
THE MAJOR WEATHER FEATURES...AND A GENERAL BLEND WILL BE
CONTINUED. THERE REMAINS SOME UNCERTAINTY AS TO HOW FAST THE
CUTOFF LOW ON THE WEST COAST WILL EJECT ACROSS THE COUNTRY MID
WEEK AND ARRIVE NEXT WEEKEND. SO WE TEMPERED DOWN THE LIKELY POP
FROM THE ALL-BLEND FOR LATE IN THE EXTENDED.
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT.
LOW CLOUDS HAVE HUNG TOUGH ACROSS THE AREA TONIGHT...KEEPING LOW
TEMPS FROM BOTTOMING OUT AROUND FREEZING IN THE NW. TEMPS IN THAT
AREA ARE STILL DOMINATED BY UPPER 30S AND LOWER 40S AT 08Z...BUT
SOME THINNING TO THE LOW CLOUD DECK MAY OCCUR IN THE FAR WEST BY
SUNRISE. THE LATEST RAP(RUC) GUIDANCE HAS A DECENT HANDLE ON THE
CURRENT CLOUD TRENDS...AND INDICATES A GRADUAL DEPARTURE OF CLOUDS
TODAY. THE NW AREAS SHOULD SEE SOME CLEARING BY NOON...WITH
CLOUDS DISSIPATING IN THE EAST DUE TO MIXING OF DRY AIR FROM
ALOFT AS CLOUDS CONTINUE TO DEPART EASTWARD. THE INCREASING
SUNSHINE WILL STILL HAVE A TOUGH TIME BATTLING THE COLD POOL AND
850MB TEMPS AROUND -3C TO -4C. HIGHS WILL STRUGGLE TO REACH INTO
THE LOWER 50S.
CLEAR SKIES AND LIGHT WINDS WILL BE ESPECIALLY PROMINENT FOR
AREAS EAST OF I-57...CLOSER TO THE DEPARTING COLD POOL.
THEREFORE...THE BETTER CHANCES FOR ANY FROST OR FREEZING
CONDITIONS WILL OCCUR THERE. WE CANT RULE OUT SOME FROST
CONDITIONS FOR OUR FAR NORTHERN COUNTIES /KNOX-STARK-MARSHALL/ BUT
FROST CHANCES WILL BE LOWER IN THE WESTERN AREAS DUE TO A
SOUTHERLY WIND THAT WILL BEGIN TO DEVELOP BY 12Z/7AM MONDAY.
THAT SOUTHERLY RETURN FLOW WILL TRIGGER A WARMING TREND AT THE
SURFACE AND ALOFT UNTIL THE ARRIVAL OF OUR NEXT COLD FRONT TUESDAY
NIGHT. HIGHS ON MONDAY WILL CLIMB INTO THE LOW 60S IN THE
WEST...WITH AROUND 60 IN THE EAST. TUESDAY WILL SEE INCREASING
HIGH CLOUDS LATE IN THE DAY...BUT ENOUGH SUNSHINE SHOULD BE
PRESENT ALONG WITH GUSTY SOUTH WINDS TO BUMP HIGHS INTO THE MID
60S NORTHEAST TO LOW 70S SOUTHWEST.
DESPITE AN ACTIVE FRONTAL CIRCULATION AND ISENTROPIC UPGLIDE WITH
THE FRONTAL PASSAGE TUESDAY NIGHT...MOISTURE LEVELS WILL NOT BE
EXCESSIVELY HIGH. THAT IS NOTED BY THE NAM PRESENTING A DRY FRONTAL
PASSAGE. HOWEVER...THE GFS/GEM/ECMWF ALL HAVE BEEN CONSISTENT WITH
GENERATING SHOWER ACTIVITY IN A MAJORITY OF CENTRAL IL AT SOME
POINT TUES NIGHT. THEREFORE...WE KEPT MID CHANCE POPS GOING.
SHOWERS WILL BE ENDING FROM WEST TO EAST AFTER MIDNIGHT...WITH
EVEN SOME CLEARING WEST OF I-55 BY 12Z/7AM WED.
LONG TERM...WEDNESDAY THROUGH SATURDAY.
A COOLER NORTHWEST FLOW BEHIND THAT COLD FRONT WILL KEEP WEDNESDAYS
HIGHS IN THE UPPER 50S TO AROUND 60. A QUICK REBOUND IN TEMPS IS
EXPECTED FOR THURSDAY AHEAD OF THE NEXT COLD FRONT. BREEZY SOUTH
WINDS AND MID LEVEL WARM AIR ADVECTION WILL HELP BOOST THURSDAYS
HIGHS BACK INTO THE MID 60S.
THURSDAY NIGHT CONTINUES TO BE THE TARGET PERIOD FOR RAIN CHANCES
WITH THE SECOND COLD FRONT THIS WEEK. GULF MOISTURE RETURNING UP
THE MISSISSIPPI RIVER VALLEY WILL FUEL A BAND OF SHOWERS AHEAD OF
THE FRONT. HOWEVER...THE TRACK OF AN UPPER LEVEL SHORTWAVE FROM
WEST TO EAST ACROSS SOUTHERN IL AS THE FRONT ARRIVES MAY KEEP THE
BULK OF THE RAINFALL JUST TO THE SOUTH OF OUR COUNTIES. WE TRENDED
CHANCES POPS FARTHER SOUTH...MAINLY SOUTH OF I-70...WITH SLIGHT
CHANCE POPS UP TO I-72.
FRIDAY SHOULD REMAIN DRY WITH A 1030MB HIGH PASSING ACROSS THE
UPPER MIDWEST. THE ECMWF AND GFS...AS WELL AS THE LAST 24HRS OF
THE 00Z CANADIAN GEM SHOW THE REX BLOCK/CUT-OFF LOW ALONG THE WEST
COAST EJECTING RAPIDLY ACROSS THE COUNTRY STARTING LATE THURSDAY
NIGHT. THE SPEED WITH WHICH THIS FEATURE MOVES ACROSS THE ROCKIES
MAY BE A BIT OVERDONE...SO THE ARRIVAL TIME OF RAIN NEXT WEEKEND
MAY BE DELAYED FROM CURRENT MODEL INDICATIONS. WE KEPT CHANCE POPS
GOING IN THE WEST ON FRIDAY NIGHT AND EVERYWHERE ON SATURDAY...BUT
TEMPERED BACK FROM THE MORE AGGRESSIVE NUMBERS OF THE ALL-BLEND.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
551 PM MDT MON OCT 8 2012
.UPDATE...
ISSUED AT 550 PM MDT MON OCT 8 2012
ADDED A MENTION OF PATCHY FROST TO THE FORECAST FOR THE AREAS THAT
WERE IN THE FROST ADVISORY LAST NIGHT. THIS INCLUDES LOCATIONS
FROM YUMA COUNTY TO RAWLINS AND SOUTH. LATEST FORECAST HAS LOW
TEMPERATURES IN THE MID 30S WITH LIGHT WINDS PRIOR TO WINDS
INCREASING AHEAD OF THE FRONT. DURING THIS WINDOW FROST MAY FORM...ESPECIALLY
IN LOW LYING AREAS. AT THIS TIME DO NOT HAVE ENOUGH CONFIDENCE TO
ISSUE AN ADVISORY DUE TO CLOUDS UPSTREAM AHEAD OF THE FRONT WHICH
SHOULD HELP PREVENT WIDESPREAD FROST FROM DEVELOPING. IN ADDITION
TEMPERATURES THIS AFTERNOON ARE MUCH WARMER THAN YESTERDAY...SO
HAVE SOME UNCERTAINTY THAT LARGE AREAS WILL DROP INTO THE LOWER
30S BEFORE THE WINDS INCREASE. WILL CONTINUE TO MONITOR INCASE
TEMPERATURES DROP INTO THE LOWER 30S SOONER THAN EXPECTED.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 128 PM MDT MON OCT 8 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE SCALE
TROUGH DOMINATING PATTERN ACROSS NORTH AMERICAN...WITH BROAD
LONG WAVE TROUGH IN PLACE OVER CANADA. ON TROUGH AXIS EXTENDS SOUTH
ALONG THE MISSISSIPPI RIVER VALLEY...WITH A CLOSED UPPER LOW OFF THE
CALIFORNIA COAST. W/NW FLOW IS IN PLACE OVER THE TRI STATE REGION
WITH A SHORTWAVE TROUGH UPSTREAM OVER WYOMING. AT THE SURFACE A COLD
FRONT IS CURRENTLY EXTENDING ACROSS SOUTHERN MONTANA INTO THE
NORTHERN PART OF SOUTH DAKOTA.
THIS COLD FRONT IS EXPECTED TO DROP SOUTH ACROSS THE CWA BETWEEN
09-12Z...WITH WINDS INCREASING BEHIND IT. I HAVE CONCERNS THAT WE
MAY REACH WIND ADVISORY CRITERIA ACROSS OUR SOUTHEAST BETWEEN
12-15Z...WITH ADVERTISED PRESSURE RISES BETWEEN 8-11MB AND H85 WINDS
AROUND 14Z. THE BIGGEST QUESTION WILL BE WHETHER THESE WINDS CAN MIX
DOWN BEFORE THE PRESSURE GRADIENT BEGINS TO WEAKEN OVER OUR CWA. FOR
I INCREASED WINDS TO JUST BELOW ADVISORY CRITERIA...WITH CONFIDENCE
TOO LOW AT THIS TIME. LARGE SCALE ASCENT AND BEST MOISTURE SHOULD
REMAIN WELL NORTH OF THE CWA...SO ONLY MID-HIGH CLOUDS ARE EXPECTED
TUESDAY MORNING.
ON ANOTHER NOTE...NAM/SREF CONTINUE TO ADVERTISE POSSIBLE FOG
DEVELOPMENT ACROSS THE NORTHWEST. THIS COINCIDES WITH THE AREAS
THAT RECEIVED SNOW SEVERAL DAYS AGO THAT HAS ALREADY MELTED. BOTH
MODELS HAVE SIGNIFICANTLY HIGHER TD VALUES THAN WHAT IS CURRENTLY
OCCURRING...SO CONSIDERING THIS BIAS I WILL NOT BE INCLUDING FOG IN
THE FORECAST FOR TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 131 PM MDT MON OCT 8 2012
SHORTWAVE RIDGING WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY
WITH TEMPERATURES NEAR NORMAL AND DRY CONDITIONS. A CUT OFF LOW
WILL MOVE ACROSS THE SOUTHERN AND CENTRAL ROCKIES LATE THIS WEEK.
CURRENTLY THE MODELS BRING THE SYSTEM INTO THE LOCAL AREA FRIDAY
AND SATURDAY...HOWEVER TIMING MAY BE TOO FAST GIVEN PREVIOUS
EXPERIENCE WITH CUT OFF SYSTEMS AND IT MAY NOT ARRIVE UNTIL FRIDAY
NIGHT OR SATURDAY AND DEPART SATURDAY NIGHT OR SUNDAY. THERE WILL
BE A CHANCE FOR SEVERE THUNDERSTORMS AS THE MAIN DYNAMICS ARRIVE
FOLLOWED BY A DRY SLOT AND EVENTUALLY SOME LIGHT WRAPAROUND
PRECIPITATION ON THE BACKSIDE. THERE IS NOT MUCH COLD AIR WITH THE
SYSTEM SO NO WINTRY WEATHER EXPECTED. NORTHWEST FLOW WILL BECOME
ESTABLISHED EARLY NEXT WEEK WITH A HINT OF ANOTHER SHORTWAVE
TROUGH...THOUGH MOISTURE MAY BE LIMITED WITH THAT SYSTEM.
TEMPERATURES WILL BE BELOW NORMAL FRIDAY THROUGH SUNDAY WITH THE
PRECIPITATION AND CLOUDS...THEN NEAR NORMAL EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 517 PM MDT MON OCT 8 2012
MAINLY VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE TAF PERIOD
AT BOTH MCK AND GLD. A COLD FRONT WILL MOVE THROUGH BOTH TAF SITES
AROUND 12Z TOMORROW MORNING BRINGING A FEW MID TO LOW LEVEL CLOUDS
AND STRONG NORTHERLY WINDS...GUSTING UP 30KTS AT TIMES. WINDS WILL
DIMINISH BY THE EARLY AFTERNOON TO 12KTS OR LESS AS THE FRONT EXITS
THE REGION AND HIGH PRESSURE BUILDS INTO THE AREA. THERE EXISTS THE
POSSIBILITY FOR A SHORT PERIOD OF MVFR CEILINGS WITH LOW CLOUDS
ASSOCIATED WITH THE FRONTAL PASSAGE...SO ALLUDED TO THIS BY
MENTIONING A SCATTERED DECK AROUND 1800FT AT GLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JJM/JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
601 AM MDT SUN OCT 7 2012
.UPDATE...
ISSUED AT 558 AM MDT SUN OCT 7 2012
UPDATED THE FORECAST TO CANCELL THE SOUTHWEST PORTION OF THE
FREEZE WARNING.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 243 AM MDT SUN OCT 7 2012
FORECAST CONCERNS WILL BE HOW MUCH THE TEMPERATURES MODERATE THROUGH
MONDAY BEFORE THE NEXT COLD FRONT MOVES IN TO COOL OFF TUESDAY.
SATELLITE CONTINUING TO SHOW AN AMPLIFIED PATTERN FROM THE PACIFIC
INTO EASTERN NORTH AMERICA. FLOW DOMINATED BY A BLOCK ALONG THE WEST
COAST AND A TROUGH OVER THE CENTRAL AND EASTERN PORTION OF THE
COUNTRY. COLD AND MOIST AIR MASS REMAINS OVER THE CENTRAL PORTION OF
THE COUNTRY.
MODELS INITIALIZED FINE AT THE JET AND MID LEVELS. NAM WAS CATCHING
THE SURFACE RIDGING AND WIND FIELD IN OUR AREA THE BEST. NAM AND
RUC APPEAR TO BE CATCHING THE STRATUS FIELD THE BEST. THE GFS AND
CANADIAN WERE DOING A LITTLE BETTER THAN THE REST ON THE LOW LEVEL
THERMAL FIELD.
TODAY/TONIGHT...STRATUS KEEPS EDGING EVER SO SLOWLY SOUTHWEST. NOT
SURE HOW MUCH FURTHER IT WILL GO. LOCATIONS ON THE EDGE OF THIS
CLOUD FIELD ARE NOT THAT FAR AWAY FROM REACHING THE NEEDED
TEMPERATURES FOR THE FREEZE WARNING TO VERIFY. AT THIS TIME I WILL
LET THE FREEZE WARNING CONTINUE BUT FEELING IS THAT THE FAR
SOUTHWEST AND WESTERN PORTIONS WILL NOT MAKE IT.
SOME FOG HAS DEVELOPED. THE 00Z NAM DRASTICALLY OVERDID THE FOG. THE
06Z NAM IS NOW MORE REALISTIC AND DEVELOPING FOG IN AREAS THAT HAVE
CLEARED. THE HRRR AND RUC DO NOT AGREE WITH EACH OTHER BUT TEND TO
FAVOR THE WEST AND MORE IN LOCATIONS THAT HAVE THE STRATUS. AT THIS
TIME WILL ADD FOG PER THE LATEST NAM WHICH DOES MAKE SENSE.
WEAK LEFT FRONT QUADRANT OF THE UPPER JET AND A RATHER STRONG
SHORTWAVE MOVES THROUGH DURING THE LATE MORNING AND AFTERNOON. WILL
HAVE TO KEEP WATCHING BUT THESE FEATURES LOOK TO SPREAD SOME HIGHER
LEVEL CLOUD COVER ACROSS THE AREA. TEMPERATURES TODAY WILL BE
AFFECTED BY HOW FAST THE STRATUS LEAVES WHICH LOOKS TO BE BY LATE
MORNING. HAVE AN AREA IN THE NORTHERN PORTION OF THE AREA THAT HAD
SIX PLUS INCHES OF SNOW YESTERDAY. AREAS DOWNSTREAM OF SNOW FIELD
COULD BE AFFECT. WITH WARM GROUND WOULD IMAGINE THAT SNOW WOULD MELT
A LITTLE FASTER THAN NORMAL. WILL DEFINITELY HAVE AN AFFECT TODAY ON
THE TEMPERATURES AND MADE THAT AREA COOLER THAN SURROUNDING
LOCATIONS. IF STRATUS HOLDS ON LONGER ALL THE TEMPERATURES MAY END
UP BEING TOO WARM.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF UPPER JET MOVES ACROSS
AT THE BEGINNING OF THE DAY. IT LOOKS LIKE IT WILL SPREAD SOME CLOUDS
ACROSS THE AREA. MODELS SHOW GOOD DOWNSLOPE WINDS THROUGH MOST OF
THE DAY UNTIL THEY BECOME LIGHTER AND MORE IN THE MIDDLE OF THE
AFTERNOON. SO WILL TREND TOWARD THE WARMER GUIDANCE.
THERE IS SOME MODEL DIFFERENCES IN HOW TO HANDLE THE SYSTEM DIGGING
OUT OF CENTRAL CANADA. THE NAM IS FASTER AND DEEPER. GFS IS NOT AS
DEEP. OTHER MODELS ARE FAIRLY DEEP...SLOWER AND ARE A LITTLE
FURTHER SOUTHWEST. AS A CONSEQUENCE THE NAM IS THE FASTEST TO PUSH
THE FRONT THROUGH AND THROUGH MOST OF THE AREA BY 12Z. IT IS ALWAYS
POSSIBLE IN THIS SCENARIO THAT FRONTS WILL COME IN FASTER BUT AM
LEARY OF THE NAM A LITTLE. SO WENT IN THE MIDDLE OF THE SOLUTIONS.
TUESDAY/TUESDAY NIGHT...ABOVE MENTIONED JET MOVES ACROSS DURING THE
MORNING BUT MODELS INDICATE VERY LITTLE CLOUD COVER WILL BE GENERATED
BY THIS FEATURE. ALL THE MODELS HAVE THE FRONT THROUGH THE FORECAST
AREA BY 18Z. THERE IS A LITTLE BIT OF SPREAD IN HOW MUCH COOLING
TAKES PLACE. THE NAM IS THE WARMEST BUT NOT BY MUCH AND THE ECMWF
THE COOLEST. THE OTHER MODELS CLUSTER IN THE MIDDLE. AT THIS TIME
WILL GO WITH A COMPROMISE OF TEMPERATURES WHICH DOES LOWER THE
MAXES A LITTLE.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 243 AM MDT SUN OCT 7 2012
THE UPPER PATTERN DURING THIS PERIOD WILL TRANSITION FROM FAST
NORTHWEST FLOW ALOFT ON WED TO UPPER RIDGING THU-EARLY FRI TO STRONG
SOUTHWEST FLOW LATER FRI-SAT AS THE UPPER LOW APPROACHING CALIFORNIA
EJECTS NORTHEAST ACROSS THE CENTRAL HIGH PLAINS. NUMERICAL GUIDANCE
HAS VASTLY DIFFERING SOLUTIONS ON WHERE AND HOW FAST THE UPPER LOW
LIFTS OUT OF THE SOUTHWEST U.S. WHICH IS ULTIMATELY TIED TO THE
LOCATION AND INTENSITY OF THE NEXT UPSTREAM TROUGH. THE EC IS NOW
CONSIDERABLY FASTER AND MUCH FURTHER NORTH COMPARED TO GFS. SATURDAY
MORNING THE EC HAS THE UPPER LOW OVER CENTRAL NEBRASKA WHILE GFS
HOLDS IT BACK OVER THE FOUR CORNERS. THE GEM WAS PRETTY MUCH IN STEP
WITH THE GFS THRU 144 HRS /FRI/. NEEDLESS TO SAY...CONFIDENCE IS
LOW IN THE TIMING AND AMOUNT OF ASSOCIATED PRECIP IN THE FRI-SAT
TIME FRAME. EXPERIENCE WOULD FAVOR A SLOWER /GFS/ MOVEMENT BUT A
BLEND IS PROBABLY APPROPRIATE AT THIS POINT. WHICHEVER MODEL
VERIFIES... IF EITHER ONE DOES... WILL ALSO MAKE A BIG DIFFERENCE IN
THE POTENTIAL TO GET DRY SLOTTED. WHATEVER THE OUTCOME...LOOKS LIKE
A RETURN TO MORE TYPICAL OCTOBER TEMPERATURES GIVEN THE UPPER
PATTERN CHANGE DURING PERIOD.
AT THE SURFACE...ONE LAST CANADIAN HIGH PRESSURE AREA WILL DROP
SOUTHEAST INTO THE AREA THURSDAY BEFORE UPPER RIDGING AND SOUTHWEST
FLOW ALOFT TAKE OVER. THE EC IS A LITTLE SLOWER WITH THE COLD
FRONTAL PASSAGE COMPARED TO GFS/GEM WHICH COULD MAKE THURSDAY MAX
TEMPS A LITTLE TRICKY. CURRENT FORECAST HAS MAX TEMPERATURES IN THE
UPPER 60S/LOWER 70S BEFORE FRONTAL PASSAGE.
THE NEXT SHOT AT PRECIP LOOKS TO BE TOWARD THE END OF THIS FORECAST
PERIOD WITH TIMING DEPENDING ON SPEED AT WHICH UPPER LOW EJECTS
NORTHEAST. THE EC BRINGS IN POTENTIAL FOR SHOWERS AND THUNDERSTORMS
EARLY FRIDAY MORNING WHILE GFS TIMING IS FRIDAY NIGHT INTO SATURDAY.
CURRENT FORECAST IS A BLEND OF NUMERICAL GUIDANCE AND BRINGS IN
CHANCE POPS STARTING FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 558 AM MDT SUN OCT 7 2012
KGLD WILL HAVE MVFR CONDITIONS UNTIL 18Z THEN VFR FOR THE
REMAINDER OF THE PERIOD. KMCK WILL HAVE LIFR CONDITIONS BEFORE
GRADUALLY IMPROVING BY 18Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FREEZE WARNING UNTIL 10 AM CDT THIS MORNING FOR KSZ001>004-
014>016-028-029.
CO...FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ090.
NE...FREEZE WARNING UNTIL 9 AM MDT /10 AM CDT/ THIS MORNING FOR
NEZ079>081.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
243 AM MDT SUN OCT 7 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 243 AM MDT SUN OCT 7 2012
FORECAST CONCERNS WILL BE HOW MUCH THE TEMPERATURES MODERATE THROUGH
MONDAY BEFORE THE NEXT COLD FRONT MOVES IN TO COOL OFF TUESDAY.
SATELLITE CONTINUING TO SHOW AN AMPLIFIED PATTERN FROM THE PACIFIC
INTO EASTERN NORTH AMERICA. FLOW DOMINATED BY A BLOCK ALONG THE WEST
COAST AND A TROUGH OVER THE CENTRAL AND EASTERN PORTION OF THE
COUNTRY. COLD AND MOIST AIR MASS REMAINS OVER THE CENTRAL PORTION OF
THE COUNTRY.
MODELS INITIALIZED FINE AT THE JET AND MID LEVELS. NAM WAS CATCHING
THE SURFACE RIDGING AND WIND FIELD IN OUR AREA THE BEST. NAM AND
RUC APPEAR TO BE CATCHING THE STRATUS FIELD THE BEST. THE GFS AND
CANADIAN WERE DOING A LITTLE BETTER THAN THE REST ON THE LOW LEVEL
THERMAL FIELD.
TODAY/TONIGHT...STRATUS KEEPS EDGING EVER SO SLOWLY SOUTHWEST. NOT
SURE HOW MUCH FURTHER IT WILL GO. LOCATIONS ON THE EDGE OF THIS
CLOUD FIELD ARE NOT THAT FAR AWAY FROM REACHING THE NEEDED
TEMPERATURES FOR THE FREEZE WARNING TO VERIFY. AT THIS TIME I WILL
LET THE FREEZE WARNING CONTINUE BUT FEELING IS THAT THE FAR
SOUTHWEST AND WESTERN PORTIONS WILL NOT MAKE IT.
SOME FOG HAS DEVELOPED. THE 00Z NAM DRASTICALLY OVERDID THE FOG. THE
06Z NAM IS NOW MORE REALISTIC AND DEVELOPING FOG IN AREAS THAT HAVE
CLEARED. THE HRRR AND RUC DO NOT AGREE WITH EACH OTHER BUT TEND TO
FAVOR THE WEST AND MORE IN LOCATIONS THAT HAVE THE STRATUS. AT THIS
TIME WILL ADD FOG PER THE LATEST NAM WHICH DOES MAKE SENSE.
WEAK LEFT FRONT QUADRANT OF THE UPPER JET AND A RATHER STRONG
SHORTWAVE MOVES THROUGH DURING THE LATE MORNING AND AFTERNOON. WILL
HAVE TO KEEP WATCHING BUT THESE FEATURES LOOK TO SPREAD SOME HIGHER
LEVEL CLOUD COVER ACROSS THE AREA. TEMPERATURES TODAY WILL BE
AFFECTED BY HOW FAST THE STRATUS LEAVES WHICH LOOKS TO BE BY LATE
MORNING. HAVE AN AREA IN THE NORTHERN PORTION OF THE AREA THAT HAD
SIX PLUS INCHES OF SNOW YESTERDAY. AREAS DOWNSTREAM OF SNOW FIELD
COULD BE AFFECT. WITH WARM GROUND WOULD IMAGINE THAT SNOW WOULD MELT
A LITTLE FASTER THAN NORMAL. WILL DEFINITELY HAVE AN AFFECT TODAY ON
THE TEMPERATURES AND MADE THAT AREA COOLER THAN SURROUNDING
LOCATIONS. IF STRATUS HOLDS ON LONGER ALL THE TEMPERATURES MAY END
UP BEING TOO WARM.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF UPPER JET MOVES ACROSS
AT THE BEGINNING OF THE DAY. IT LOOKS LIKE IT WILL SPREAD SOME CLOUDS
ACROSS THE AREA. MODELS SHOW GOOD DOWNSLOPE WINDS THROUGH MOST OF
THE DAY UNTIL THEY BECOME LIGHTER AND MORE IN THE MIDDLE OF THE
AFTERNOON. SO WILL TREND TOWARD THE WARMER GUIDANCE.
THERE IS SOME MODEL DIFFERENCES IN HOW TO HANDLE THE SYSTEM DIGGING
OUT OF CENTRAL CANADA. THE NAM IS FASTER AND DEEPER. GFS IS NOT AS
DEEP. OTHER MODELS ARE FAIRLY DEEP...SLOWER AND ARE A LITTLE
FURTHER SOUTHWEST. AS A CONSEQUENCE THE NAM IS THE FASTEST TO PUSH
THE FRONT THROUGH AND THROUGH MOST OF THE AREA BY 12Z. IT IS ALWAYS
POSSIBLE IN THIS SCENARIO THAT FRONTS WILL COME IN FASTER BUT AM
LEARY OF THE NAM A LITTLE. SO WENT IN THE MIDDLE OF THE SOLUTIONS.
TUESDAY/TUESDAY NIGHT...ABOVE MENTIONED JET MOVES ACROSS DURING THE
MORNING BUT MODELS INDICATE VERY LITTLE CLOUD COVER WILL BE GENERATED
BY THIS FEATURE. ALL THE MODELS HAVE THE FRONT THROUGH THE FORECAST
AREA BY 18Z. THERE IS A LITTLE BIT OF SPREAD IN HOW MUCH COOLING
TAKES PLACE. THE NAM IS THE WARMEST BUT NOT BY MUCH AND THE ECMWF
THE COOLEST. THE OTHER MODELS CLUSTER IN THE MIDDLE. AT THIS TIME
WILL GO WITH A COMPROMISE OF TEMPERATURES WHICH DOES LOWER THE
MAXES A LITTLE.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 243 AM MDT SUN OCT 7 2012
THE UPPER PATTERN DURING THIS PERIOD WILL TRANSITION FROM FAST
NORTHWEST FLOW ALOFT ON WED TO UPPER RIDGING THU-EARLY FRI TO STRONG
SOUTHWEST FLOW LATER FRI-SAT AS THE UPPER LOW APPROACHING CALIFORNIA
EJECTS NORTHEAST ACROSS THE CENTRAL HIGH PLAINS. NUMERICAL GUIDANCE
HAS VASTLY DIFFERING SOLUTIONS ON WHERE AND HOW FAST THE UPPER LOW
LIFTS OUT OF THE SOUTHWEST U.S. WHICH IS ULTIMATELY TIED TO THE
LOCATION AND INTENSITY OF THE NEXT UPSTREAM TROUGH. THE EC IS NOW
CONSIDERABLY FASTER AND MUCH FURTHER NORTH COMPARED TO GFS. SATURDAY
MORNING THE EC HAS THE UPPER LOW OVER CENTRAL NEBRASKA WHILE GFS
HOLDS IT BACK OVER THE FOUR CORNERS. THE GEM WAS PRETTY MUCH IN STEP
WITH THE GFS THRU 144 HRS /FRI/. NEEDLESS TO SAY...CONFIDENCE IS
LOW IN THE TIMING AND AMOUNT OF ASSOCIATED PRECIP IN THE FRI-SAT
TIME FRAME. EXPERIENCE WOULD FAVOR A SLOWER /GFS/ MOVEMENT BUT A
BLEND IS PROBABLY APPROPRIATE AT THIS POINT. WHICHEVER MODEL
VERIFIES... IF EITHER ONE DOES... WILL ALSO MAKE A BIG DIFFERENCE IN
THE POTENTIAL TO GET DRY SLOTTED. WHATEVER THE OUTCOME...LOOKS LIKE
A RETURN TO MORE TYPICAL OCTOBER TEMPERATURES GIVEN THE UPPER
PATTERN CHANGE DURING PERIOD.
AT THE SURFACE...ONE LAST CANADIAN HIGH PRESSURE AREA WILL DROP
SOUTHEAST INTO THE AREA THURSDAY BEFORE UPPER RIDGING AND SOUTHWEST
FLOW ALOFT TAKE OVER. THE EC IS A LITTLE SLOWER WITH THE COLD
FRONTAL PASSAGE COMPARED TO GFS/GEM WHICH COULD MAKE THURSDAY MAX
TEMPS A LITTLE TRICKY. CURRENT FORECAST HAS MAX TEMPERATURES IN THE
UPPER 60S/LOWER 70S BEFORE FRONTAL PASSAGE.
THE NEXT SHOT AT PRECIP LOOKS TO BE TOWARD THE END OF THIS FORECAST
PERIOD WITH TIMING DEPENDING ON SPEED AT WHICH UPPER LOW EJECTS
NORTHEAST. THE EC BRINGS IN POTENTIAL FOR SHOWERS AND THUNDERSTORMS
EARLY FRIDAY MORNING WHILE GFS TIMING IS FRIDAY NIGHT INTO SATURDAY.
CURRENT FORECAST IS A BLEND OF NUMERICAL GUIDANCE AND BRINGS IN
CHANCE POPS STARTING FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1115 PM MDT SAT OCT 6 2012
FOR KGLD MVFR CIGS EXPECTED THROUGH 18Z OR SO AS AXIS OF LOW LEVEL
MOISTURE REMAINS OVER THE TERMINAL. AFTER 18Z VFR CONDITIONS
EXPECTED. AT KMCK SMALL AREA OF STRATUS AND IFR CIGS CURRENTLY
OVER THE TERMINAL. THIS SHOULD CONTINUE FOR A FEW HOURS BEFORE
MOVING OUT OF THE AREA LEAVING VFR CONDITIONS THROUGH THE
REMAINDER OF THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FREEZE WARNING UNTIL 9 AM MDT /10 AM CDT/ SUNDAY FOR KSZ001>004-
013>016-027>029-041-042.
CO...FREEZE WARNING UNTIL 9 AM MDT SUNDAY FOR COZ090>092.
NE...FREEZE WARNING UNTIL 9 AM MDT /10 AM CDT/ SUNDAY FOR NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...DDT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1219 AM CDT SUN OCT 7 2012
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1256 PM CDT SAT OCT 6 2012
A DEEP LONGWAVE TROUGH ENCOMPASSED MUCH OF THE NORTHERN CONUS WITH
250MB CYCLONICALLY CURVED FLOW FROM THE GREAT BASIN THROUGH THE
GREAT PLAINS TO THE GREAT LAKES REGION. WITHIN THE LONGWAVE
TROUGH...A SHORTWAVE TROUGH WAS MOVING SOUTHEAST THROUGH WESTERN
NEBRASKA EARLY SATURDAY. 12Z UPPER AIR ANALYSIS REVEALED 700MB
FRONTOGENETIC ZONE EXTENDING FROM SOUTHERN WYOMING THROUGH EASTERN
COLORADO TO SOUTHWESTERN KANSAS WITH SATURATED OR NEAR SATURATED AIR
(700MB DEWPOINT DEPRESSIONS 0 OR 1 DEGC AT KRIW, KDNR, KDDC, KAMA,
KOUN). PRECIPITATION IN THE FORM OF RAIN AND SNOW EXTENDED ALL
ALONG THE STRONGEST ZONE OF MID LEVEL FRONTOGENESIS (THE STRONGEST
OF WHICH FROM NORTHEAST COLORADO TO NORTHWEST KANSAS TO FAR
SOUTHWEST NEBRASKA AS OF 17Z). LIGHTER BANDED PRECIPITATION WAS
FOUND ACROSS SOUTHWEST KANSAS WHERE 0.06 INCHES OF PRECIPITATION WAS
MEASURED SO FAR AT DODGE CITY (ALL IN THE FORM OF RAIN). SNOW WAS
REPORTED AS FAR SOUTHEAST AS DIGHTON...AND VERY BRIEFLY MIXED IN
WITH RAIN ACROSS THE NORTHWEST PORTIONS OF FORD COUNTY DURING ONE OF
THE HEAVIER BANDS EARLIER THIS MORNING. IT SEEMS THE SNOW LINE IS
MATCHING UP WELL WITH THE RAP ANALYZED 900 FT AGL FREEZING
LEVEL...WHICH EXTENDED FROM ROUGHLY GARDEN CITY TO DIGHTON (AND
POINTS NORTHWEST) AT 18Z.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 316 PM CDT SAT OCT 6 2012
THIS EVENING:
MID LEVEL FRONTOGENESIS (MAINLY CENTERED AROUND 700MB) WILL CONTINUE
TO DECREASE ACROSS WEST CENTRAL AND CENTRAL KANSAS AS THE MID LEVEL
SHORTWAVE TROUGH ACROSS SOUTHWEST NEBRASKA MOVES TOWARD SOUTHEAST
NEBRASKA. MID LEVEL DRYING FROM 800 TO 500MB (AND ABOVE THROUGH THE
UPPER TROPOSPHERE) WILL INCREASE AS SUBSIDENCE PREVAILS IN THE WAKE
OF THE PRIMARY SHORTWAVE TROUGH. MOISTURE AND ATTENDANT CLOUD IN THE
LOWER TROPOSPHERE (800-900MB) WILL ALSO BE DECREASING...HOWEVER RATE
OF DECREASE ACROSS SOUTHWEST AND WEST CENTRAL KANSAS IS STILL A
FAIRLY CHALLENGING FORECAST AS LOW STRATUS WILL BE DIFFICULT TO
DISLODGE AS REMNANT LOW LEVEL MOISTURE RECIRCULATES AROUND THE
ANTICYCLONE IN THIS LAYER. FEEL THAT CLOUDS IN THE 800-900MB LAYER
WILL SCATTER OUT SLOWLY FROM 00-06Z TONIGHT...AND MOST PROMINENT
FARTHER NORTHEAST AWAY FROM COLORADO.
OVERNIGHT:
A 1030MB SURFACE HIGH WILL BE MOVING SOUTH-SOUTHEAST WITH CENTER OF
SURFACE HIGH TAKING A TRACK FROM ROUGHLY WRAY, COLORADO TO DODGE
CITY TONIGHT. ALONG THE TRACK OF THE SURFACE HIGH SKY SHOULD CLEAR
OUT AFTER MIDNIGHT...AND TEMPERATURES WILL FALL INTO THE LOWER 30S
RATHER QUICKLY ONCE CLOUDS CLEAR. TEMPERATURES WILL MOST LIKELY
FALL TO 28 TO 30 DEGREES NORTH OF THE ARKANSAS RIVER BY 08 OR 09Z
AND REMAIN IN THIS RANGE FOR PROBABLY 4 OR 5 HOURS...WITH MINIMUM
AROUND SUNRISE OF 25 TO 27 DEGREES NORTH OF A DIGHTON TO NESS CITY
TO LACROSSE LINE. THIS IS MORE OR LESS A CONTINUATION OF THE
PREVIOUS FORECAST AND AM NOT MAKING ANY CHANGES TO THE GOING FREEZE
HEADLINES. WILL CONTINUE THE HARD FREEZE WARNING (28 DEGREES OR
BELOW FOR LOWS) NORTH OF A JOHNSON TO BUCKLIN TO STAFFORD LINE.
SOUTH OF THIS LINE TO THE OKLAHOMA BORDER WILL CONTINUE WITH THE
FREEZE WARNING FOR LOWS 29 TO 32 DEGREES. MUCH, IF NOT ALL, OF WEST
CENTRAL, SOUTHWEST, AND SOUTH CENTRAL KANSAS WILL SEE THE END TO THE
GROWING SEASON WITH THESE FORECAST TEMPERATURES TONIGHT.
SUNDAY:
A SECONDARY MINOR SHORTWAVE DISTURBANCE WILL BE ROTATING AROUND THE
MEAN TROUGH AXIS FROM SOUTHERN WYOMING TO NORTHEASTERN NEW
MEXICO...WHICH MAY BRING SOME MID LEVEL CLOUD BACK TO FAR SOUTHWEST
KANSAS BY DAYBREAK...HOWEVER NO OTHER SENSIBLE WEATHER IMPACTS ARE
EXPECTED WITH THIS FINAL SHORTWAVE TROUGH PASSAGE. THE SURFACE HIGH
WILL SHIFT INTO THE RED RIVER VALLEY BY MIDDAY SUNDAY...BUT OVERALL
PRESSURE GRADIENT WILL REMAIN RATHER WEAK WITH SOUTHWEST WINDS 8 TO
10 KNOTS EXPECTED. A WARMING OF THE LOWER TROPOSPHERE FROM DOWNSLOPE
MOMENTUM (850MB TEMPS INCREASING TO +5 TO +9C FROM EAST TO WEST)
WILL ALLOW SURFACE TEMPERATURES TO WARM UP WELL INTO THE MID TO
UPPER 50S...ESPECIALLY ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT OCT 6 2012
MONDAY:
BROAD 500-250 HPA WNW FLOW IS EXPECTED MONDAY. THIS ORTHOGONAL FLOW
WRT THE ROCKIES WILL ALLOW FOR A LEE TROUGH TO FORM MONDAY FROM THE
SURFACE UP TO 850 HPA. AS A RESULT, A WEAK WARM AIR ADVECTION REGIME
IS EXPECTED WITH HIGHS MODERATING TO THE UPPER 60S DEG F TO AROUND
70 DEG F. A DRY FORECAST IS EXPECTED FOR THE BEGINNING OF THE WORK WEEK
AS THE REGION WILL BE FREE OF ANY SYNOPTIC DISTURBANCES AND ASSOCIATED
LIFT.
TUESDAY:
THE SYNOPTIC PATTERN CHANGES TUESDAY AS A BROAD POSITIVELY TILTED UPPER
LEVEL SHORTWAVE TROF EJECTS FROM THE CANADIAN PRAIRIES AND ACROSS THE
NORTHERN PLAINS. THIS UL FEATURE WILL USHER IN A PASSAGE OF A COLD FRONT.
HAVE USED 12Z ECMWF AS GUIDANCE FOR TEMPERATURES AS THE GFS CONTINUES
TO PERFORM POORLY (IN THIS CASE, USUALLY TOO AGGRESSIVE WITH THE FROPA).
HIGHS WILL VARY ACROSS THE REGION WITH LOW TO MID 60S DEG F ACROSS THE
INTERSTATE 70 CORRIDOR TO MID 70S DEG F ACROSS EXTREME SOUTHWEST KANSAS.
THIS FRONT WILL BE DRY WITH A LACK OF BOUNDARY LAYER MOISTURE IN PLACE.
WILL KEEP POPS NEAR ZERO PERCENT. SFC WINDS DON`T LOOK PARTICULARLY
STRONG WITH THIS HIGH AS 850 HPA WINDS ARE ONLY FORECAST TO BE IN THE
20-25 KT RANGE.
WEDNESDAY:
A RIDGE OF HIGH PRESSURE WILL TRANSLATE ACROSS THE SUNFLOWER STATE WEDNESDAY
IN THE WAKE OF THE DENSITY GRADIENT. HIGHS IN THE 60S DEG F ARE EXPECTED
AS FAIRLY COOL 850 HPA TEMPERATURES (9-13 DEG C) ARE FORECAST IN ASSOCIATION
WITH THE AFOREMENTIONED COOL HIGH PRESSURE CENTER MOVING ACROSS THE
STATE. WILL ALSO RUN WITH THE ALLBLEND POPS (AROUND 3 PERCENT) FOR
THE MIDDLE PORTION OF THE WORK WEEK.
THURSDAY AND BEYOND:
THE FORECAST BECOMES MORE INTERESTING TOWARDS THE END OF THE WORK WEEK
ALTHOUGH SYNOPTIC AND MESOSCALE DETAILS ARE VERY UNCERTAIN AT THIS POINT.
FOR EXAMPLE, YESTERDAYS ECMWF RUN HAD THE WARM SECTOR (HIGHER THETA-E
AIR) SPREADING NORTHWARD IN ASSOCIATION WITH THE PASSAGE OF A WARM FRONT
FRIDAY. TODAY`S 12Z ECMWF RUN KEEPS THAT BOUNDARY SOUTH OF THE REGION
FRIDAY. THIS BOUNDARY PLACEMENT WILL HAVE SIGNIFICANT IMPACTS IN TERMS
OF SENSIBLE WEATHER AS A WAA PATTERN/THETA-E ADVECTION ALONG SAID FRONT
COULD LEAD TO THE DEVELOPMENT OF CONVECTION ACROSS THE PLAINS. FOR NOW
WILL GO WITH A BLEND OF THE ALLBLEND POPS ALTHOUGH WILL SMOOTH POPS
TOWARDS A BIAS TO THE ECMWF. THE GFS WAS GENERALLY DISREGARDED AS THE
MODEL CONTINUES TO BE VERY PROGRESSIVE WITH UL FEATURES THAT WILL PROBABLY
SLOW DOWN WITH TIME. IT SHOULD BE NOTED THAT MUCH UNCERTAINTY EXISTS
WITH THE EVOLUTION OF THE DESERT SOUTHWEST UL LOW THAT WILL BE THE IMPETUS
FOR CONVECTION. IT ALSO SHOULD BE NOTED THAT THERE IS THE POSSIBILITY
OF SEVERE CONVECTION, PARTICULARLY FRIDAY AND SATURDAY. WARM SECTOR
PLACEMENT AND ASSOCIATED REDISTRIBUTION OF ENERGY PER UNIT MASS (I.E.
CAPE) IS UNCERTAIN. REGARDLESS OF WHEREVER THE WARM SECTOR WILL BE,
THE ECMWF SHOWS SIGNIFICANT BOUNDARY LAYER MOISTURE WORKING ITS WAY
NORTH FROM THE GULF OF MEXICO. KINEMATIC PROFILES ALSO STRENGTHEN WITH
TIME AS THE UL LOW MOVES CLOSER TO KANSAS WITH 250 HPA FLOW INCREASING
TO 100 KT, 500 HPA FLOW INCREASING TO 60 KT, AND FAIRLY STRONG AND VEERING
FLOW FROM THE SFC THROUGH 700 HPA. SEVERE WEATHER EPISODES IN OCTOBER
ARE NOT UNUSUAL FOR THE PLAINS. IN FACT, THERE WERE TORNADOES LAST OCTOBER
ACROSS THE REGION LAST YEAR. IT IS TOO EARLY TO DETERMINE STORM MODE
AND PLACEMENT AT THIS TIME BUT IT IS SOMETHING TO WATCH FOR IN FUTURE
MODEL RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1219 AM CDT SUN OCT 7 2012
MVFR CIGS AT GARDEN CITY WILL GRADUALLY INCREASE TO VFR AROUND
09Z-10Z AS DRIER AIR MOVES INTO SOUTHWEST KANSAS. VFR CIGS AT
DODGE CITY WILL CONTINUE THROUGH MOST OF THE NIGHTTIME HOURS
BEFORE SCATTERING OUT. LOOK FOR MOSTLY CLEAR SKIES TO CONTINUE AT
HAYS. LIGHT AND VARIABLE WINDS WILL BECOME SOUTHWESTERLY AT 10 TO
12 KNOTS BY MIDDAY SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 69 43 69 / 0 0 0 0
GCK 32 69 42 67 / 0 0 0 0
EHA 35 67 44 77 / 0 0 0 0
LBL 34 67 42 73 / 0 0 0 0
HYS 34 70 44 66 / 0 0 0 0
P28 35 69 46 71 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR
KSZ030-031-043>046-061>066-074>079.
FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR KSZ080-081-
084>090.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...SUGDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1247 AM EDT SUN OCT 07 2012
...Updated Aviation Discussion...
.Forecast Update...
Updated at 1027 PM EDT Sat Oct 6 2012
HRRR and RAP show KY staying dry tonight and this is supported by
regional radars and upstream obs. Decent band of reflectivities
passed over Logan and Simpson Counties within the last hour but
neither Mesonet station reported measurable rainfall. So, will back
off on PoPs a bit. Will still keep some low chances going far south
though in case any activity can blossom ahead of the approaching
upper trof or slip over the border from Tennessee.
&&
.Short Term (Today through Sunday)...
Issued at 300 PM EDT Sat Oct 6 2012
A persistent Rex Block at 500mb just off the Pacific Coast has
allowed
northerly flow to develop downstream across the Upper Midwest. A
chilly Canadian airmass has already penetrated practically as far
south as the Texas Gulf coast, and remains banked up against higher
terrain in New Mexico and Colorado.
Clouds will increase this evening as one of several flat
disturbances embedded within a broader 500mb cyclonic gyre scoots
across Missouri. Both the GFS and NAM models take this feature
across Tennessee and southern Kentucky during the overnight hours. A
light chilly rain may develop across our southern counties later
this evening, ending around dawn across our southern Bluegrass or
Lake Cumberland Region. Precipitation totals will stay light,
totaling around two tenths of an inch or less. Feel that Louisville
and possible Lexington will stay north of this potential strip of
precipitation. Expect a cloudy cool night with lows ranging from
just under 40 to the lower 40s.
Skies will clear pretty readily Sunday morning as this 500mb wave
passes and subsidence overspreads the area. Canadian high pressure
will settle over the southern plains by Sunday afternoon, with an
axis extending east across the Commonwealth. Light north winds
Sunday afternoon will become calm overnight through Monday.
Early Monday will provide our best chance for widespread frost and
even a chance of a light freeze across some of our colder rural
locations. Frost chances will depend on how clear we become by early
Monday. High clouds associated with a disturbance over Tennessee may
spread as far north as Interstate 64 early Monday. This may, if
thick enough, limit frost chances across our south. Agricultural
interests should however, plan on at least some frost across
southern Indiana and north central Kentucky. Some lows early Monday
may reach or approach 32 for a few hours.
.Long Term (Monday - Saturday)...
Issued at 300 PM EDT Sat Oct 6 2012
High pressure will be over the region Monday morning at the same
time a vortmax is crossing the region aloft. Clouds associated with
this shortwave will be over or just east of the eastern forecast
area at the start of this period. During the day Monday and
continuing into Tuesday, the high will become centered over New
England.
Tuesday night, a cold front will move into the Midwest. Moisture
ahead of this front is not that impressive but will be enough to
warrant a chance for rain to come through the forecast area. After
that front, another cold shot of Canadian air will build into the
region, with high pressure becoming centered over the region
Thursday morning. Deterministic and Ensemble models support this
scenario, meaning another chilly morning with more frost possible
Thursday morning.
Progressive flow aloft, with persistent troughiness across eastern
Canada, will bring another moisture-starved front through the region
Friday morning. The high behind this front looks to move more to our
north. This may allow for a quicker return of moisture into the area
for next weekend. 00Z ECMWF and latest GFS/DGEX all indicate some
weak warm frontal-type forcing across the region Saturday, with the
latter two bringing rain into the region. For now will lean toward
the ECMWF solution, which keeps the best rain chances to our
northwest.
&&
.Aviation (06Z TAF Issuance)...
Issued at 1247 PM EDT Sun Oct 7 2012
A few light returns on radar are courtesy of a shortwave over the
Midwest. However, very few observations have recorded rain other
than a sprinkle or two. Have therefore decided to remove mentionable
rain from the BWG TAF. As the shortwave moves east today the mid
level clouds will move out with mainly cirrus expected through the
rest of the TAF period. Winds will be out of the northwest and
become light and variable to calm tomorrow night as surface high
pressure settles directly over the region.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......JSD
Long Term........RJS
Aviation.........EER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
953 AM EDT SUN OCT 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION EARLY TODAY. LOW
PRESSURE WILL TRACK EAST OF THE GULF OF MAINE TONIGHT INTO
MONDAY MORNING. HIGH PRESSURE WILL RIDGE ACROSS THE REGION
ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
950 AM UPDATE...ONLY MINOR ADJUSTMENTS NEEDED FOR THIS UPDATE.
INCREASED POPS JUST A BIT LATE THIS AFTERNOON AS PER HRRR MODEL,
WHICH IS SHOWING ISOLATED SHOWERS COMING INTO FAR SOUTHERN
PORTIONS OF THE AREA TOWARD 4-5 PM. ALSO TWEAKED SKY COVER TO
MATCH CURRENT SATELLITE. NO OTHER CHANGES NEEDED.
PREVIOUS DISCUSSION...
MAIN CHALLENGE WILL BE OF COURSE THE TEMPERATURES AND QPF.
WEAK HIGH PRES RIDGING WILL QUICKLY GIVE WAY TO THE NEXT SYSTEM
APCHG FROM MID ATLC REGION LATER THIS AFTERNOON INTO TONIGHT. CLOUDS
WILL BE BACK ON THE INCREASE AFTER SOME PARTIAL CLEARING IN ADVANCE
OF THE WEAK LOW APCHG FROM THE S TODAY. TEMPERATURES WILL BE
COOLER THAN THEY HAVE BEEN THE LAST FEW DAYS W/READINGS BACK TO
AOB NORMAL LEVELS FOR EARLY OCTOBER. DECIDED ON A BLEND OF THE
NAM12 AND GMOS FOR TODAY/S MAXES WHICH SHOWS LOW TO MID 50S NORTH
AND MID TO TO UPPER 50S CENTRAL AND DOWNEAST.
THE CHALLENGE FOR TONIGHT IS HOW FAR NORTH WILL PRECIP GET AND
HOW COLD WILL TEMPERATURES BE. ALL THE SHORT RANGE GUIDANCE
INCLUDING THE CANADIAN GEM/NAM AND GFS SHOW PRECIP SHIELD EDGING
ITS WAY INTO COASTAL AND SWRN AREAS BY EARLY EVENING. THE PRECIP
IS EXPECTED TO SPREAD NNE OVERNIGHT AS LOW PRES MOVES NE ACROSS
THE GULF OF MAINE. ATTM, THE BEST LIFT APPEARS TO BE SITUATED
ACROSS THE DOWNEAST AND EASTERN SECTIONS AND THIS IS WHERE THE
HIGHER QPF VALUES WERE PLACED(.25-.30"). THE 00Z NAM AND GFS BOTH
POINT TO A VIGOROUS VORTICITY MAX W/DECENT ADVECTION TO MOVE
ACROSS THE STATE OVERNIGHT INTO EARLY MONDAY MORNING. THIS WILL
AID IN PROVIDING ADDITION LIFT FOR PRECIP. THE 00Z ECWMF SHOWS
THIS FEATURE AS WELL AS DOES THE LATEST WV SATL IMAGERY W/THE VORT
MAX OVER MISSOURI. THEREFORE, SQUEEZED POPS DOWN SOME W/40-50%
ACROSS THE FAR N AND NW AND LIKELY TO CATEGORICAL(60-90%) FOR THE
CENTRAL AND DOWNEAST REGION INCLUDING THE COAST. PRECIP WILL BE IN
THE FORM OF RAIN FOR ALL AREAS AS TEMPERATURES WILL REMAIN ABOVE
32-33F. THE EXCEPTION TO THIS WILL BE THE FAR W AND NW AREAS AS
SOME SNOW COULD MIX IN W/THE RAIN BY 09Z MONDAY AS TEMPERATURES
ARE EXPECTED TO FALL BACK INTO THE LOWER 30S(33-34F). THE 00Z
ECMWF HAS 925MB TEMPERATURES FALLING TO NEAR 0C IN THESE AREAS BY
EARLY MONDAY MORNING. 07Z SFC ANALYSIS SHOWED TEMPERATURES IN THE
LOW 30S ACROSS WESTERN QUEBEC AND OTTAWA. IF THE CHANGEOVER
OCCURS, IT WILL BE BRIEF AS THE PRECIP WILL SHUT OFF QUICKLY AS
THE LOW EXITS ACROSS NOVA SCOTIA AND HIGH PRES BEGINS TO RIDGE
FROM THE S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE START OF THE SHORT TERM FINDS THE MODELS IN GOOD AGREEMENT. A
LOW OVER ERN NOVA SCOTIA AND ASSOCIATED FRONTAL SYSTEM EXITING THE
AREA TO THE EAST...A HIGH PRESSURE RIDGE DOMINATING THE WEATHER
ACROSS MUCH OF THE MIDDLE AND ERN PORTIONS OF THE UNITED STATES. A
MAJOR SHORT WAVE TROUGH EXTENDING SOUTH ACROSS LAKE MICHIGAN INTO
NRN LA. A NEW LOW MVG SE OUT OF WRN CANADA INTO THE NRN PLAINS.
MON EVNG THE THE LOW OVR NOVA SCOTIA MOVES EAST INTO THE
MARITIMES. THE HIGH PRESSURE RIDGE EXTENDS ACROSS MAINE. THE NEW
LOW MOVES SE INTO LAKE SUPERIOR...AN ASSOCIATED UPPER LOW STACKED
TO THE NW OF THE SFC LOW. THE SHORT WAVE TROUGH MOVES EAST TO THE
APPALACHIANS. TUES MRNG THE LOW OVR LAKE SUPERIOR MOVES NE TO THE
NRN TIP OF SUPERIOR...THE UPPER LOW CONTINUES TO SUPPORT THE SFC
LOW. BY THE END OF THE PERIOD. THE HIGH PRESSURE RIDGE REMAINS
OVER MAINE. THE LOW OVR NRN LAKE SUPERIOR MOVES NE INTO SRN JAMES
BAY...DEEPENS AT THIS POINT THE UPPER LOW HAS BECOME VERTICALLY
STACKED WITH THE SFC SYSTEM.
LOADED MATCH GUIDANCE FOR MAX/MIN. BLENDED THE GFS/NAM HRLY
TEMP/DP. BLENDED THE GFS/NAM/OFFICIAL FOR WNDS/SKY/POP.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AT THE START OF THE LONG TERM THE MODELS CONTINUE TO BE IN GOOD
AGREEMENT. A HIGH PRESSURE RIDGE EXTENDING FROM ERN QUEBEC TO THE
GULF OF MEXICO WILL DOMINATE THE WEATHER FOR THE LOCAL AREA EARLY
IN THE PERIOD. A DEEPENING LOW OVER SRN JAMES BAY...WITH AN
ASSOCIATED FRONT WRAPPED AROUND THE LOW THEN EXTENDING SOUTH
THROUGH WRN LAKE HURON...LAKE MICHIGAN...TO NWRN IL. BY WED EVNG
THE FRONT MOVES EAST INTO WRN MAINE...THE ASSOCIATED LOW CONTINUES
TO MOVE NE INTO NRN QUEBEC. THE ASSOCIATED SHORT WAVE EXTENDS
THROUGH THE ERN GREAT LAKES TO SRN GA. A NEW LOW MOVES INTO THE
NRN PLAINS FROM NW CANADA. THURS MRNG THE FRONT MOVES THROUGH
MAINE...HIGHER PRESSURE STARTS TO BUILD INTO SW ME. THE NEW LOW
MOVES EAST TO LAKE SUPERIOR. THE UPPER LVLS WILL BECOME MORE
ZONAL. SYSTEMS WILL TRANSIT QUICKLY ACROSS THE NRN US...BY THURS
EVNG THE NEW LOW TRACK ACROSS THE GREAT LAKE TO SRN QUEBEC. BY
EARLY FRI MRNG THE LOW WILL MOVE INTO NW ME. BY FRI MRNG (THE GFS)
THE LOW WILL BE INTO NRN NEW BRUNSWICK AND HIGHER PRESSURE WILL
BEGIN TO BUILD INTO ME. (THE ECMWF) THE LOW WILL MOVE TO CNTRL
QUEBEC...TRAILING A FRONT ACROSS NW ME. FRI EVNG THE GFS MOVES THE
SYSTEM WELL EAST OF MAINE...BEGINS TO BUILD HIGHER PRESSURE. THE
ECMWF MOVES THE LOW AND ASSOCIATED FRONT EAST OF MAINE. HIGHER
PRESSURE WILL DOMINATE THROUGH SAT. BY SAT EVNG THERE WILL BE A
NEW LOW OVR WRN KS THIS LOW WILL DEEPEN RAPIDLY...AND MOVE NE TO
NRN IA...ITS ASSOCIATED WARM FRONT WILL EXTEND EAST INTO SRN NH.
BY THE END OF THE PERIOD THE LOW WILL BE OVER SRN QUEBEC. THE
ASSOCIATED WARM FRONT EXTENDING THROUGH MAINE.
LOADED GMOS... ADJUSTED SKY/POPS WITH GFS FOR WED-SAT. GMOS
GUIDANCE TO HIGH GFS. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL
WATERS. ADDED 20 PERCENT FOR WNDS OVR THE WATERS...15 PERCENT OVR
LAND.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR LOOKS TO BE THE GOING RATE INTO EARLY EVENING AND
THEN MVFR CONDITIONS POSSIBLE ACROSS KBGR AND KBHB. VFR IS
EXPECTED TO HOLD ACROSS THE NORTHERN TERMINALS.
SHORT TERM: MVFR CONDITIONS AT ALL SITES RAPIDLY IMPROVING AS
FRONTAL SYSTEM MOVES EAST OF THE AREA. VFR CONDITIONS AT ALL SITES
BY MID MORNING MONDAY. VFR CONDITIONS WILL CONTINUE INTO
TUESDAY...ISOLATED SHOWER/THUNDERSTORMS FOR BGR...BHB TUESDAY
AFTERNOON...MVFR TO IFR CONDITIONS DURING PCPN. CONDITIONS WILL
FALL TO MVFR ON WEDNESDAY SOUTH TO NORTH...BHB...BGR IN THE
MORNING THE OTHER SITES DURING THE AFTERNOON AS A LOW PRESSURE
CENTER TRANSITS THROUGH THE GULF OF MAINE. IFR CONDITIONS WILL
CONTINUE THROUGH THE END OF THE PERIOD.
&&
.MARINE...
NEAR TERM: DROPPED THE SCA AS WINDS/SEAS ARE BELOW CRITERIA. NO
HEADLINES FOR THIS TERM. USED A BLEND OF THE NAM12 AND GFS FOR THE
WINDS WHICH SUPPORTS 10-15 KTS SUSTAINED BY TONIGHT. STAYED CLOSE
TO THE DAYCREW`S WAVE HEIGHTS OF 2-3 FT.
SHORT TERM: WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH MID DAY
WEDNESDAY. SEAS WILL BEGIN TO BUILD AT WEDNESDAY EVENING AS A
FRONTAL SYSTEM MOVES INTO THE GULF OF MAINE WATERS. AN SCA MAYBE
REQUIRED WED THROUGH THURS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/NORTON
AREA FORECAST DISCUSSION
NWS CARIBOU ME
645 AM EDT SUN OCT 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION EARLY TODAY. LOW
PRESSURE WILL TRACK EAST OF THE GULF OF MAINE TONIGHT INTO
MONDAY MORNING. HIGH PRESSURE WILL RIDGE ACROSS THE REGION
ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: ADJUSTED THE SKY CONDITIONS USING THE LATEST IR SATL
IMAGERY AND THE HRRR WHICH APPEARS TO BE DOING WELL. CLEARING WILL
GIVE WAY TO CLOUDS LATER THIS MORNING INTO THE AFTERNOON. ADJUSTED
THE HRLY TEMPS AS WELL UPWARD AS PREVIOUS THINKING WAS TOO COLD.
PULL THE FOG FOR THE REMAINDER OF THE MORNING.
PREVIOUS DISCUSSION...
MAIN CHALLENGE WILL BE OFF COURSE THE TEMPERATURES AND QPF.
WEAK HIGH PRES RIDGING WILL QUICKLY GIVE WAY TO THE NEXT SYSTEM
APCHG FROM MID ATLC REGION LATER THIS AFTERNOON INTO TONIGHT. CLOUDS
WILL BE BACK ON THE INCREASE AFTER SOME PARTIAL CLEARING IN ADVANCE
OF THE WEAK LOW APCHG FROM THE S TODAY. TEMPERATURES WILL BE
COOLER THAN THEY HAVE BEEN THE LAST FEW DAYS W/READINGS BACK TO
AOB NORMAL LEVELS FOR EARLY OCTOBER. DECIDED ON A BLEND OF THE
NAM12 AND GMOS FOR TODAY/S MAXES WHICH SHOWS LOW TO MID 50S NORTH
AND MID TO TO UPPER 50S CENTRAL AND DOWNEAST.
THE CHALLENGE FOR TONIGHT IS HOW FAR NORTH WILL PRECIP GET AND
HOW COLD WILL TEMPERATURES BE. ALL THE SHORT RANGE GUIDANCE
INCLUDING THE CANADIAN GEM/NAM AND GFS SHOW PRECIP SHIELD EDGING
ITS WAY INTO COASTAL AND SWRN AREAS BY EARLY EVENING. THE PRECIP
IS EXPECTED TO SPREAD NNE OVERNIGHT AS LOW PRES MOVES NE ACROSS
THE GULF OF MAINE. ATTM, THE BEST LIFT APPEARS TO BE SITUATED
ACROSS THE DOWNEAST AND EASTERN SECTIONS AND THIS IS WHERE THE
HIGHER QPF VALUES WERE PLACED(.25-.30"). THE 00Z NAM AND GFS BOTH
POINT TO A VIGOROUS VORTICITY MAX W/DECENT ADVECTION TO MOVE
ACROSS THE STATE OVERNIGHT INTO EARLY MONDAY MORNING. THIS WILL
AID IN PROVIDING ADDITION LIFT FOR PRECIP. THE 00Z ECWMF SHOWS
THIS FEATURE AS WELL AS DOES THE LATEST WV SATL IMAGERY W/THE VORT
MAX OVER MISSOURI. THEREFORE, SQUEEZED POPS DOWN SOME W/40-50%
ACROSS THE FAR N AND NW AND LIKELY TO CATEGORICAL(60-90%) FOR THE
CENTRAL AND DOWNEAST REGION INCLUDING THE COAST. PRECIP WILL BE IN
THE FORM OF RAIN FOR ALL AREAS AS TEMPERATURES WILL REMAIN ABOVE
32-33F. THE EXCEPTION TO THIS WILL BE THE FAR W AND NW AREAS AS
SOME SNOW COULD MIX IN W/THE RAIN BY 09Z MONDAY AS TEMPERATURES
ARE EXPECTED TO FALL BACK INTO THE LOWER 30S(33-34F). THE 00Z
ECMWF HAS 925MB TEMPERATURES FALLING TO NEAR 0C IN THESE AREAS BY
EARLY MONDAY MORNING. 07Z SFC ANALYSIS SHOWED TEMPERATURES IN THE
LOW 30S ACROSS WESTERN QUEBEC AND OTTAWA. IF THE CHANGEOVER
OCCURS, IT WILL BE BRIEF AS THE PRECIP WILL SHUT OFF QUICKLY AS
THE LOW EXITS ACROSS NOVA SCOTIA AND HIGH PRES BEGINS TO RIDGE
FROM THE S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE START OF THE SHORT TERM FINDS THE MODELS IN GOOD AGREEMENT. A
LOW OVER ERN NOVA SCOTIA AND ASSOCIATED FRONTAL SYSTEM EXITING THE
AREA TO THE EAST...A HIGH PRESSURE RIDGE DOMINATING THE WEATHER
ACROSS MUCH OF THE MIDDLE AND ERN PORTIONS OF THE UNITED STATES. A
MAJOR SHORT WAVE TROUGH EXTENDING SOUTH ACROSS LAKE MICHIGAN INTO
NRN LA. A NEW LOW MVG SE OUT OF WRN CANADA INTO THE NRN PLAINS.
MON EVNG THE THE LOW OVR NOVA SCOTIA MOVES EAST INTO THE
MARITIMES. THE HIGH PRESSURE RIDGE EXTENDS ACROSS MAINE. THE NEW
LOW MOVES SE INTO LAKE SUPERIOR...AN ASSOCIATED UPPER LOW STACKED
TO THE NW OF THE SFC LOW. THE SHORT WAVE TROUGH MOVES EAST TO THE
APPALACHIANS. TUES MRNG THE LOW OVR LAKE SUPERIOR MOVES NE TO THE
NRN TIP OF SUPERIOR...THE UPPER LOW CONTINUES TO SUPPORT THE SFC
LOW. BY THE END OF THE PERIOD. THE HIGH PRESSURE RIDGE REMAINS
OVER MAINE. THE LOW OVR NRN LAKE SUPERIOR MOVES NE INTO SRN JAMES
BAY...DEEPENS AT THIS POINT THE UPPER LOW HAS BECOME VERTICALLY
STACKED WITH THE SFC SYSTEM.
LOADED MATCH GUIDANCE FOR MAX/MIN. BLENDED THE GFS/NAM HRLY
TEMP/DP. BLENDED THE GFS/NAM/OFFICIAL FOR WNDS/SKY/POP.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AT THE START OF THE LONG TERM THE MODELS CONTINUE TO BE IN GOOD
AGREEMENT. A HIGH PRESSURE RIDGE EXTENDING FROM ERN QUEBEC TO THE
GULF OF MEXICO WILL DOMINATE THE WEATHER FOR THE LOCAL AREA EARLY
IN THE PERIOD. A DEEPENING LOW OVER SRN JAMES BAY...WITH AN
ASSOCIATED FRONT WRAPPED AROUND THE LOW THEN EXTENDING SOUTH
THROUGH WRN LAKE HURON...LAKE MICHIGAN...TO NWRN IL. BY WED EVNG
THE FRONT MOVES EAST INTO WRN MAINE...THE ASSOCIATED LOW CONTINUES
TO MOVE NE INTO NRN QUEBEC. THE ASSOCIATED SHORT WAVE EXTENDS
THROUGH THE ERN GREAT LAKES TO SRN GA. A NEW LOW MOVES INTO THE
NRN PLAINS FROM NW CANADA. THURS MRNG THE FRONT MOVES THROUGH
MAINE...HIGHER PRESSURE STARTS TO BUILD INTO SW ME. THE NEW LOW
MOVES EAST TO LAKE SUPERIOR. THE UPPER LVLS WILL BECOME MORE
ZONAL. SYSTEMS WILL TRANSIT QUICKLY ACROSS THE NRN US...BY THURS
EVNG THE NEW LOW TRACK ACROSS THE GREAT LAKE TO SRN QUEBEC. BY
EARLY FRI MRNG THE LOW WILL MOVE INTO NW ME. BY FRI MRNG (THE GFS)
THE LOW WILL BE INTO NRN NEW BRUNSWICK AND HIGHER PRESSURE WILL
BEGIN TO BUILD INTO ME. (THE ECMWF) THE LOW WILL MOVE TO CNTRL
QUEBEC...TRAILING A FRONT ACROSS NW ME. FRI EVNG THE GFS MOVES THE
SYSTEM WELL EAST OF MAINE...BEGINS TO BUILD HIGHER PRESSURE. THE
ECMWF MOVES THE LOW AND ASSOCIATED FRONT EAST OF MAINE. HIGHER
PRESSURE WILL DOMINATE THROUGH SAT. BY SAT EVNG THERE WILL BE A
NEW LOW OVR WRN KS THIS LOW WILL DEEPEN RAPIDLY...AND MOVE NE TO
NRN IA...ITS ASSOCIATED WARM FRONT WILL EXTEND EAST INTO SRN NH.
BY THE END OF THE PERIOD THE LOW WILL BE OVER SRN QUEBEC. THE
ASSOCIATED WARM FRONT EXTENDING THROUGH MAINE.
LOADED GMOS... ADJUSTED SKY/POPS WITH GFS FOR WED-SAT. GMOS
GUIDANCE TO HIGH GFS. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL
WATERS. ADDED 20 PERCENT FOR WNDS OVR THE WATERS...15 PERCENT OVR
LAND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR LOOKS TO BE THE GOING RATE INTO EARLY EVENING AND
THEN MVFR CONDITIONS POSSIBLE ACROSS KBGR AND KBHB. VFR IS
EXPECTED TO HOLD ACROSS THE NORTHERN TERMINALS.
SHORT TERM: MVFR CONDITIONS AT ALL SITES RAPIDLY IMPROVING AS
FRONTAL SYSTEM MOVES EAST OF THE AREA. VFR CONDITIONS AT ALL SITES
BY MID MORNING MONDAY. VFR CONDITIONS WILL CONTINUE INTO
TUESDAY...ISOLATED SHOWER/THUNDERSTORMS FOR BGR...BHB TUESDAY
AFTERNOON...MVFR TO IFR CONDITIONS DURING PCPN. CONDITIONS WILL
FALL TO MVFR ON WEDNESDAY SOUTH TO NORTH...BHB...BGR IN THE
MORNING THE OTHER SITES DURING THE AFTERNOON AS A LOW PRESSURE
CENTER TRANSITS THROUGH THE GULF OF MAINE. IFR CONDITIONS WILL
CONTINUE THROUGH THE END OF THE PERIOD.
&&
.MARINE...
NEAR TERM: DROPPED THE SCA AS WINDS/SEAS ARE BELOW CRITERIA. NO
HEADLINES FOR THIS TERM. USED A BLEND OF THE NAM12 AND GFS FOR THE
WINDS WHICH SUPPORTS 10-15 KTS SUSTAINED BY TONIGHT. STAYED CLOSE
TO THE DAYCREW`S WAVE HEIGHTS OF 2-3 FT.
SHORT TERM: WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH MID DAY
WEDNESDAY. SEAS WILL BEGIN TO BUILD AT WEDNESDAY EVENING AS A
FRONTAL SYSTEM MOVES INTO THE GULF OF MAINE WATERS. AN SCA MAYBE
REQUIRED WED THROUGH THURS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...HEWITT
MARINE...HEWITT/NORTON
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
920 PM EDT MON OCT 8 2012
.SYNOPSIS...
CLOUDS WILL BE ON THE DECREASE OVERNIGHT AS HIGH PRESSURE BUILDS
INTO THE AREA. SUNNY AND COOL WEATHER IS PREDICTED FOR TUESDAY
AFTER ANY MORNING FOG BURNS OFF. THE NEXT CHANCE OF RAINFALL ARRIVES
WEDNESDAY WITH THE APPROACH OF A COLD FRONT. WARMER WEATHER IS IN
STORE THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CLEARING HAS REACHED THE OHIO RIVER NE TO FKL...BUT IT WILL BE
SLOWER TO EXIT NRN WV AND SWRN PA THE BALANCE OF THE NIGHT. LATEST
HRRR AND RAP MODEL PORTRAY CLEARING TO TAKE PLACE IN THE MGW TO
AGC CORRIDOR AROUND 6Z. THIS BRINGS THE QUESTION WILL STRATUS /
FOG FORMATION OCCUR RAPIDLY AFTER THE SKY CLEARS OR WILL IT TAKE A
FEW HOURS. IF THE LATTER OCCURS THEN WE SHOULD REACH INTO THE
LOWER 30S. HOWEVER IF FOG DEVELOPS RAPIDLY AND BASED ON CROSSOVER
TEMPS FROM BUFKIT...IT SHOULD WITHIN 1-3HRS...TEMPS SHALL STAY IN
THE MID 30S.
CONFIDENCE NOT HIGH ENOUGH TO DROP ANY COUNTIES FROM THE NPW...BUT
NWRN PA...ECNTRL OH...AND WV PANHANDLE LOOK LIKE THEY WILL FALL INTO
THE L30S. LOCATIONS IN EXTREME SWRN PA AND MGW VCNTY WILL BE THE
LAST TO CLEAR...SO THEY WILL BE THE LAST TO EXPERIENCE SUB
FREEZING TEMPERATURES.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
CROSSING SFC HIGH PRESSURE WILL MAINTAIN DRY AND COOL WEATHER
THROUGH TUESDAY NIGHT...ALTHOUGH WARM ADVCTN IN ADVN OF A SHRTWV
PROGGED ACRS SRN CANADA WL WARM TEMPERATURES ABOVE READINGS
RECORDED OVR THE PAST COUPLE OF DAYS.
BY WEDNESDAY...THAT DISTURBANCE IS FORECAST TO DRAG ANOTHER CDFNT ACRS
THE UPR OH REGION...SPAWNING SOME SHRA WITH ITS PASSAGE. TIME WL BE
INSUFFICIENT FOR SIGNIFICANT BNDRY LYR MSTR RTN...SO CHC/SCT POPS WL
SUFFICE FOR ALL BUT THE NRN ZONES...WHERE LIKELY NMBRS WERE
INCLUDED FOR A CPL HRS.
THE SYSTEM AND ASSOCIATED CDFNT WL CROSS THE REGION QUICKLY IN THE
PROGRESSIVE FLOW. DRY WEATHER...WITH COOLER TEMPERATURES ARE THUS
FORECAST FOR WEDNESDAY NGT AND THURSDAY.
SHORT TERM TEMPERATURES WERE FORECAST USING SREF MEANS AND THE
LATEST GFS MOS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
PER BLEND OF RECENT NAEFS AND ECENS MODEL OUTPUT...EXPECT THE UPPER
OHIO VALLEY TO ENDURE A COLD FRONTAL PASSAGE WITH SHOWERS ON FRIDAY.
MODEL OUTPUT THEN SHOWS A MORE PROLONGED PERIOD OF SHOWERS SUNDAY
AND MONDAY WITH THE SLOWER EASTWARD PASSAGE OF MORE-DEVELOPED LOW
PRESSURE SYSTEM.
JUDGING FROM BLEND OF RECENT GFS MOS...ECMWF MOS...AND NAEFS MEDIAN
VALUES...EXPECT A WARMING TREND THIS PERIOD....AS UPPER LEVEL
JETSTREAM PATTERN TAKES ON A SOUTHWESTERLY ORIENTATION.
FORECASTED SPECIFIC TEMPERATURES TO GO FROM COOLER THAN NORMAL
VALUES FRIDAY TO VALUES AS MUCH AS 5 DEGREES WARMER THAN NORMAL
SUNDAY AND MONDAY
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
MEDIUM CONFIDENCE FORECAST. VFR WEATHER WILL PERSIST UNTIL THE
EARLY MORNING HOURS WHEN IFR VIS/CIGS DEVELOP. GIVEN THE TIME OF
YEAR AND CLIMATOLOGY...BURN OFF TIME AVERAGES BTWN 14-15Z...SO
CARRIED THIS IN TERMINALS. ONCE CIGS LIFT CAVU EXPECTED THE
BALANCE OF TUESDAY.
WHERE THE TAFS COULD GO WRONG:
/IFR CLOUDS MAY DEVELOP SOONER THAN FORECAST
/FOG MAY LIFT LATER THAN PREDICTED
.OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
BRIEF IFR RESTRICTIONS ARE POSSIBLE WITH A COLD FRONT PASSAGE
WEDNESDAY MORNING...OTHERWISE NO WIDESPREAD IFR WEATHER IS
FORESEEN THROUGH SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...FREEZE WARNING FROM 3 AM TO 9 AM EDT TUESDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FREEZE WARNING FROM 3 AM TO 9 AM EDT TUESDAY FOR PAZ007>009-
013>016-020>023-029-031-073-075.
WV...FREEZE WARNING FROM 3 AM TO 9 AM EDT TUESDAY FOR WVZ001>004-
012-021-022.
&&
$$
NEAR TERM...98
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
735 PM EDT MON OCT 8 2012
.SYNOPSIS...
CLOUDS WILL BE ON THE DECREASE OVERNIGHT AS HIGH PRESSURE BUILDS
INTO THE AREA. SUNNY AND COOL WEATHER IS PREDICTED FOR TUESDAY.
THE NEXT CHANCE OF RAINFALL ARRIVES WEDNESDAY WITH THE APPROACH OF
A COLD FRONT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
STRATOCU AND ALTOST IS HAVING A TOUGH TIME WITH AN EASTWARD
ADVANCEMENT. STEERING WINDS AT THESE LEVELS ARE WEAK OR PARALLEL
PRODUCING MINIMAL MOVEMENT WITH TROF AXIS OVERHEAD. LATEST HRRR AND
GRIDDED LAMP SUGGEST BKN-OVC CONDITIONS PERSISTING INTO THE
OVERNIGHT HOURS FOR A GOOD PART OF NRN WV AND WESTERN PA. THIS
COULD AFFECT CURRENT FREEZE WARNING AREA. WILL BE MULLING OVER THE
LATEST GUIDANCE TO SEE IF NPW HEADLINE NEEDS ADJUSTED. FOR THE
RECORD...NOT A BIG FAN OF DROPPING HEADLINES UNLESS ABOVE AVERAGE
CONFIDENCE EXISTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
CROSSING SFC HIGH PRESSURE WILL MAINTAIN DRY AND COOL WEATHER
THROUGH TUESDAY NIGHT...ALTHOUGH WARM ADVCTN IN ADVN OF A SHRTWV
PROGGED ACRS SRN CANADA WL WARM TEMPERATURES ABOVE READINGS
RECORDED OVR THE PAST COUPLE OF DAYS.
BY WEDNESDAY...THAT DISTURBANCE IS FORECAST TO DRAG ANOTHER CDFNT ACRS
THE UPR OH REGION...SPAWNING SOME SHRA WITH ITS PASSAGE. TIME WL BE
INSUFFICIENT FOR SIGNIFICANT BNDRY LYR MSTR RTN...SO CHC/SCT POPS WL
SUFFICE FOR ALL BUT THE NRN ZONES...WHERE LIKELY NMBRS WERE
INCLUDED FOR A CPL HRS.
THE SYSTEM AND ASSOCIATED CDFNT WL CROSS THE REGION QUICKLY IN THE
PROGRESSIVE FLOW. DRY WEATHER...WITH COOLER TEMPERATURES ARE THUS
FORECAST FOR WEDNESDAY NGT AND THURSDAY.
SHORT TERM TEMPERATURES WERE FORECAST USING SREF MEANS AND THE
LATEST GFS MOS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
PER BLEND OF RECENT NAEFS AND ECENS MODEL OUTPUT...EXPECT THE UPPER
OHIO VALLEY TO ENDURE A COLD FRONTAL PASSAGE WITH SHOWERS ON FRIDAY.
MODEL OUTPUT THEN SHOWS A MORE PROLONGED PERIOD OF SHOWERS SUNDAY
AND MONDAY WITH THE SLOWER EASTWARD PASSAGE OF MORE-DEVELOPED LOW
PRESSURE SYSTEM.
JUDGING FROM BLEND OF RECENT GFS MOS...ECMWF MOS...AND NAEFS MEDIAN
VALUES...EXPECT A WARMING TREND THIS PERIOD....AS UPPER LEVEL
JETSTREAM PATTERN TAKES ON A SOUTHWESTERLY ORIENTATION.
FORECASTED SPECIFIC TEMPERATURES TO GO FROM COOLER THAN NORMAL
VALUES FRIDAY TO VALUES AS MUCH AS 5 DEGREES WARMER THAN NORMAL
SUNDAY AND MONDAY
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MEDIUM CONFIDENCE FORECAST. VFR WEATHER WILL PERSIST UNTIL THE
EARLY MORNING HOURS WHEN IFR VIS/CIGS DEVELOP. GIVEN THE TIME OF
YEAR AND CLIMATOLOGY...BURN OFF TIME AVERAGES BTWN 14-15Z...SO
CARRIED THIS IN TERMINALS. ONCE CIGS LIFT CAVU EXPECTED THE
BALANCE OF TUESDAY.
WHERE THE TAFS COULD GO WRONG:
/IFR CLOUDS MAY DEVELOP SOONER THAN FORECAST
/FOG MAY LIFT LATER THAN PREDICTED
.OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
BRIEF IFR RESTRICTIONS ARE POSSIBLE WITH A COLD FRONT PASSAGE
WEDNESDAY MORNING...OTHERWISE NO WIDESPREAD IFR WEATHER IS
FORESEEN THROUGH SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...FREEZE WARNING FROM 3 AM TO 9 AM EDT TUESDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FREEZE WARNING FROM 3 AM TO 9 AM EDT TUESDAY FOR PAZ007>009-
013>016-020>023-029-031-073-075.
WV...FREEZE WARNING FROM 3 AM TO 9 AM EDT TUESDAY FOR WVZ001>004-
012-021-022.
&&
$$
SYNOPSIS/NEAR TERM/AVIATION...98
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1151 AM EDT SUN OCT 7 2012
.SYNOPSIS...
A NORTHEASTBOUND COLD UPPER LEVEL TROUGH WILL PROVIDE SCATTERED
SHOWERS THIS AFTERNOON. THEN HIGH PRESSURE WILL FOLLOW WITH CLEARING SKIES
AND LIGHT WINDS TONIGHT...WHICH MEANS TEMPERATURES MAY DROP BELOW
FREEZING EARLY MONDAY MORNING...WITH AREAS OF FROST AND PATCHY
FOG. THE HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THE REST OF
MONDAY AND TUESDAY BEFORE A CANADIAN COLD FRONT BRINGS SHOWERS
WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
CONCUR WITH RECENT RAP AND WRF-NMM MODEL OUTPUT THAT A COLD UPPER
LEVEL TROUGH WILL MOVE NORTHEASTWARD THROUGH THE UPPER OHIO VALLEY
THIS AFTERNOON WITH SCATTERED SHOWERS.
AS RECENT SREF MODEL OUTPUT AND NAM MODEL PROFILES CONTINUE TO
SHOW...HIGH PRESSURE WILL FOLLOW WITH CLEARING SKIES AND LIGHT
WINDS BY LATE TONIGHT.
THIS SCENARIO WILL BE IDEAL FOR STRONG NOCTURNAL RADIATIONAL
COOLING. HENCE WITH THIS AFTERNOONS HIGH TEMPERATURES RESTRICTED
BY THE COOL CLOUDY CONDITIONS...AS RECENT GFS LAMP SHOWS MOST
PLACES WILL STRUGGLE TO REACH 50...CONTINUE TO EXPECT LOW
TEMPERATURES EARLY MONDAY MORNING TO BE MAINLY IN THE 30 TO 35
RANGE...AS RECENT GFS AND NAM MOS INDICATE.
RECENT NAM MODEL PROFILES SHOW A PARTICULARLY STRONG YET SHALLOW SURFACE
TEMPERATURE INVERSION. SO WITH AFTERNOON SURFACE DEW POINTS IN THE
THE MID 30S...IT STILL APPEARS PLAUSIBLE FOG CAN DEVELOP LATE
TONIGHT...WITH THE RIVER VALLEYS MORE VULNERABLE THAN ELSEWHERE.
SO HAVE CONTINUED THE FREEZE WARNING WITH MENTION OF EARLY MORNING
AREAS OF FROST AND PATCHY RIVER VALLEY FOG.
HIGH PRESSURE SUBSIDENCE WILL ENSURE MOSTLY SUNNY CONDITIONS THE
REST OF DAYTIME MONDAY WITH AFTERNOON HIGH TEMPERATURES 5 TO 8
DEGREES COLDER THAN NORMAL AS SHOWN BY RECENT GFS AND NAM MOS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
RECENT SREF MODEL OUTPUT SHOWS HIGH PRESSURE WILL CONTINUE TO PROVIDE
DRY AND RELATIVELY CLOUD FREE CONDITIONS THROUGH DAYTIME TUESDAY.
THEN A COLD FRONT...WITH ORIGINS IN THE PLAINS OF CENTRAL
CANADA...WILL SWEEP THROUGH THE UPPER OHIO VALLEY WITH SHOWERS
WEDNESDAY.
REGARDING TEMPERATURES...LOWS MONDAY NIGHT CAN BE NEARLY AS COLD
THIS COMING NIGHT...SO ITS POSSIBLE THERE CAN BE PATCHES OF FROST.
HOWEVER...WILL NOT ADDRESS THIS SCENARIO UNTIL THE EXTENT OF
TONIGHTS FREEZE ON THE GROWING SEASON CAN BE ASSESSED.
PER RECENT GFS MOS AND SREF MEAN VALUES...HIGHS TUESDAY AND LOWS
TUESDAY NIGHT CAN BE NEAR NORMAL. WEDNESDAYS HIGHS WILL BE
RESTRICTED BY CLOUDS, SHOWERS, AND RENEWED COLD ADVECTION...AND SO
CAN BE MORE LIKE 5 TO 8 DEGREES COLDER THAN NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE THEN TAKES OVER ACROSS THE SOUTHEASTERN UNITED
STATES WEDNESDAY NIGHT IN ADVANCE OF A WEAK COLD FRONT MOVING
THROUGH ON FRIDAY. DOES NOT APPEAR TO BE MUCH MOISTURE WITH THE
FRONT ITSELF...BUT FEEL THAT SLIGHT CHANCE POPS ARE PRUDENT
CONSIDERING POSSIBLE LAKE INFLUENCE. HIGH PRESSURE THEN MOVES IN
ONCE AGAIN...DROPPING ACROSS THE GREAT LAKES.
LOTS OF UNCERTAINTY WITH LOW PRESSURE DEVELOPING IN THE PLAINS
FOR THE WEEKEND...BUT SHOULD BE ABLE TO SWING SOME CHANCE POPS
LATE SATURDAY.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGHOUT THE EXTENDED
PERIOD.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL PROVIDE VFR CONDITIONS EARLY WITH INCREASING MID
AND HIGH CLOUDS.
WITH AN UPPER LEVEL WAVE PASSING THROUGH DAYTIME SUNDAY...EXPECT A
RETURN OF LOWER VFR CIGS THROUGHOUT THE DAY. EXPECT LIGHT RAIN TO
DEVELOP BY MIDDAY SPREADING NORTHWARD IN THE AFTERNOON BUT EXPECT
VFR TO CONTINUE.
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL CLEAN OUT CIGS SUNDAY EVENING WITH LIGHT WINDS.
VFR CONDITIONS THROUGH MUCH OF THE OUTLOOK PERIOD. THE EXCEPTION
WILL BE WEDNESDAY...WHEN A COLD FRONT WILL BRING RESTRICTIONS IN
SHOWERS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR WVZ001>004-012-
021>023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
826 PM EDT MON OCT 8 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 436 PM EDT MON OCT 8 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF
DOMINATING ERN NAMERICA DOWNSTREAM OF A RIDGE/ANTICYCLONE OVER THE
GULF OF ALASKA. A COUPLE OF SHORTWAVES ARE EVIDENT DROPPING SE INTO
THE ERN TROF. ONE IS HEADING INTO NRN MN WHILE A SECOND STRONGER
WAVE IS DROPPING THRU SRN SASKATCHEWAN. AT THE SFC...LOW PRES
ASSOCIATED WITH THE LEAD WAVE IS OVER NW MN WITH SECONDARY CENTER
VCNTY OF LAKE WINNIPEG. IN REPONSE TO APPROACHING SHORTWAVE...12Z
RAOBS AT 850MB SHOW STRONG WAA INTO THE UPPER LAKES...CORRESPONDING
TO STRONG ISENTROPIC ASCENT PER LATEST RUC ANALYSIS. LINGERING DRY
AIR AT THE LOW LEVELS PER 12Z KGRB/KMPX SOUNDING IS SO FAR LIMITING
SRN EXTENT OF PCPN.
SHORT TERM WILL BE ACTIVE WITH THE 2 AFOREMENTIONED SHORTWAVES
AFFECTING THE AREA. PRIMARY CONCERN TONIGHT WILL BE WINDS WITHIN
TIGHT PRES GRADIENT OVER THE AREA...ESPECIALLY THE ERN FCST AREA
WHERE 925MB WINDS ARE PROGGED AT 40-50KT BY NAM/GFS. LOW-LEVEL WIND
MAX WON`T BE PASSING DURING THE FAVORABLE PART OF THE DIURNAL CYCLE
FOR MIXING. HOWEVER...AREA OF DECENT PRES FALLS PASSING JUST N OF
LAKE SUPERIOR WILL CERTAINLY BE AN ENHANCING FACTOR FOR STRONGER
WINDS. SO...CURRENT WIND ADVY LOOKS ON TRACK FOR THE DELTA/SRN
SCHOOLCRAFT WHICH ARE EXPOSED TO STRONG WINDS UP LAKE MICHIGAN.
SINCE S WINDS ARE A VERY FAVORABLE WIND DIRECTION FOR STRONGER WINDS
AT GRAND MARAIS AND KERY...OPTED TO INCLUDE ALGER/NRN SCHOOLCRAFT
AND LUCE COUNTIES IN ADVY AS WELL. AS FOR PCPN...GIVEN RADAR/SFC OB
TRENDS AND MODEL INDICATED PERIOD OF DEEP LAYER FORCING PER QVECTORS
AND STRONG ISENTROPIC ASCENT...SOME -SHRA APPEAR LIKELY TO MOVE
ACROSS THE AREA TONIGHT...ESPECIALLY NRN UPPER MI...DESPITE CURRENT
LOW-LEVEL DRY AIR. ALTHOUGH STRONGER FORCING WILL BEGIN TO LIFT
NE...FLOW UP LAKE MICHIGAN MAY PROVIDE ENOUGH LOW-LEVEL MOISTENING
TO ENHANCE PCPN CHANCE FOR THE ERN FCST AREA.
ON TUE...ATTENTION TURNS TO THE STRONGER SHORTWAVE CURRENTLY
DROPPING THRU SRN SASKATCHEWAN. IN RESPONSE...A NICE SW-NE ORIENTED
BAND OF FRONTOGENESIS DEVELOPS THRU THE WRN GREAT LAKES. MAJORITY OF
GUIDANCE APPEARS TO HAVE A BIT TOO MUCH PCPN ON THE COLD SIDE OF THE
FGEN CIRCULATION. BASED ON FGEN...THE ERN FCST SHOULD BE FAVORED FOR
PCPN...AND GRIDS REFLECT THIS WITH A GRADIENT FROM SCHC/LOW CHC POPS
OVER THE W TO HIGH LIKELY OVER THE E.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 436 PM EDT MON OCT 8 2012
ACTIVE PATTERN CONTINUES THROUGH THE WEEKEND. THE PATTERN FEATURES A
SYSTEM MOVING THROUGH EVERY COUPLE DAYS...FOLLOWED BY 12-24HRS OF LK
EFFECT PRECIPITATION AND THEN A WEAK HIGH PRESSURE RIDGE FOR ANOTHER
12-24HRS. THIS WILL CONTINUE THROUGH SUNDAY NIGHT. DUE TO THE
FREQUENT SYSTEMS MOVING THROUGH...IT WILL BE BREEZY THROUGH MUCH OF
THE PERIOD...ESPECIALLY OVER/NEAR LAKE SUPERIOR...WITH THE ONLY
TIMES WINDS WILL BE LIGHTER ARE DURING THE HIGH PRESSURE RIDGES ON
WED AFTN/EVENING AND FRIDAY.
FIRST LOW PRESSURE SYSTEM EXITING TO THE NE THROUGH ONTARIO AT THE
START OF THE PERIOD WHILE SFC TROUGH WILL BE OVER THE ERN CWA. NAM
DIFFERS FROM THE REST OF THE LARGE SCALE MODELS IN DEVELOPING
ANOTHER LOW OVER ERN LK SUPERIOR AS A SECONDARY SHORTWAVE AND LEFT
FRONT OF UPPER JET MOVE THROUGH. NOT SEEING THAT ON THE
LOCAL/NATIONAL HI-RES WRF RUNS...SO WILL DISREGARD AT THIS POINT.
PCPN SHOULD BE ONGOING OVER THE ERN THIRD OF THE CWA AHEAD OF THE
SFC TROUGH AND ASSOCIATED WITH SHORTWAVE FORCING.
BEHIND THE TROUGH...WINDS WILL SHIFT TO THE NW AND COLDER H850
TEMPS WILL SURGE SE...FALLING TO -7C BY 12Z WED. LAKE
EFFECT SHOWERS SHOULD DEVELOP THROUGH THE NIGHT...WITH THE
STRONGEST INTENSITY OVERNIGHT INTO WED MORNING. CURRENT FORECAST IS
FOR ABOUT AN INCH OVER THE HIGHER TERRAIN AREAS OF THE WRN U.P.
TUES NIGHT INTO WED MORNING. LLVL MOISTURE WILL QUICKLY PULL OUT
FROM W TO E DURING THE DAY WED AS WINDS BACK TO THE WSW IN RESPONSE
TO THE HIGH PRESSURE RIDGE MOVING THROUGH.
NEXT LOW PRESSURE SYSTEM MOVES RIGHT ACROSS LAKE SUPERIOR AS
SHORTWAVE DROPS THROUGH THE WNW FLOW. WITH THE BEST WAA/FORCING
LIKELY OVER LK SUPERIOR...WILL CONTINUE TO MENTION HIGHEST POPS
THERE AND ONLY SLIGHTS/CHANCES OVER THE SRN CWA. P-TYPE COULD BE AN
ISSUE WITH THIS SYSTEM OVER THE NRN PART OF THE CWA...MAINLY OVER
THE KEWEENAW. WITH THE DEEP MOISTURE THROUGH THE SNOW GROWTH
LAYER...EXPECT THE PCPN TO START AS SNOW. BUT LOOKING AT THE LOWER
LEVELS...DOESN/T APPEAR TO BE TOO MUCH WARM AIR TO WORK WITH. A
NEARLY ISOTHERMAL LAYER AT FREEZING FROM 1-3KFT BEFORE WARMING A
DEGREE OR TWO ABOVE FREEZING AT THE SURFACE. IN THE HEAVIER PCPN
AREAS...WOULD THINK THIS WOULD DEFINITELY STAY AS ALL SNOW...BUT
LIGHTER AREAS WOULD PROBABLY BE A MIX. FARTHER SOUTH...EXPECT A
RAIN/SNOW MIX DUE TO THE LIKELY WEAKER INTENSITY. ONCE
AGAIN...SHOULD SEE SOME LAKE EFFECT SHOWERS BEHIND THE LOW ON THURS
NIGHT INTO FRIDAY...BEFORE HIGH PRESSURE BUILDS BACK IN AND BRINGS
AN END TO THE SHOWERS.
WEEKEND SYSTEM HAS SHIFTED A LITTLE FARTHER NORTH OVER THE LAST
DAY...WITH THE STRENGTHENING SURFACE LOW NOW TRACKING OVER UPPER MI.
THIS SYSTEM IS CAUSED BY THE UPPER LOW CURRENTLY OFF THE CALIFORNIA
COAST MOVING THROUGH THE SW CONUS THIS WEEK AND EXITING INTO THE
PLAINS ON FRI NIGHT. LOCATION AND TIMING ARE IN DECENT AGREEMENT
WITH THE MODELS...ALTHOUGH THE CANADIAN AND IT/S ENS MEMBERS VARY
GREATLY FROM GFS/ECMWF. LOOKING AT 00Z GFS ENS MEMBERS...THE MEAN OF
THE MAJORITY OF MEMBERS WOULD GIVE A SOLN SIMILAR TO THE
00Z DETERMINISTIC ECMWF...WHICH THE 12Z DETERMINISTIC GFS TRENDED
TOWARDS AND WILL FOLLOW THAT SOLN. WITH THE FARTHER NORTH SOLUTION
THAN YESTERDAY...HAVE BUMPED UP POPS FOR THE SAT INTO SUNDAY PERIOD.
WARM AIR SURGING NORTH AHEAD OF THE SYSTEM SHOULD LEAD TO THE PCPN
STAYING RAIN. COULD BE SOME RUMBLES OF THUNDER ON SAT NIGHT...AS
SHOWALTER VALUES FALL TO 0 TO -1C ALONG AND JUST AHEAD OF THE SFC
LOW...ALTHOUGH MID LVL LAPSE RATES ARE MARGINAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 821 PM EDT MON OCT 8 2012
DESPITE A SERIES OF DISTURBANCES PASSING ACROSS THE UPPER GREAT
LAKES...VFR CONDITIONS SHOULD PREVAIL THRU THIS FCST PERIOD AT
KIWD/KCMX/KSAW AS LOW-LEVELS REMAIN RELATIVELY DRY UNDER CONTINUED
ADVECTION OF DRIER AIR FROM THE S. DISTURBANCE TONIGHT MAY STILL
PRODUCE A PERIOD OF -SHRA AT KIWD/KCMX THIS EVENING. PREVAILING -SHRA
ARE LESS CERTAIN AT KSAW AS BETTER FORCING TENDS TO STAY TO NW.
LOW-LEVEL JET TRAVERSING THE AERA WILL LEAD TO GUSTY WINDS THRU THE
EVENING. INCLUDED LLWS AT KCMX THIS EVENING AS WINDS LOOKED LIKE THEY
DECOUPLED THERE. SECOND DISTURBANCE MOVING INTO THE UPPER GREAT LAKES
TUE WILL BRING A ROUND OF -SHRA TO KSAW. IT APPEARS KCMX/KIWD MAY BE
JUST W OF THE MAIN PCPN AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 PM EDT MON OCT 8 2012
TIGHT PRES GRADIENT BTWN LOW PRES APPROACHING FROM NW MN AND HIGH
PRES TO THE E COMBINED WITH AREA OF PRES FALLS PASSING JUST N OF
LAKE SUPERIOR WILL RESULT IN S GALES ACROSS ROUGHLY THE E HALF OF
LAKE SUPERIOR TONIGHT. COULD BE A FEW HRS LATE EVENING INTO THE
EARLY OVERNIGHT WITH GUSTS TO AROUND 45KT AT HIGHER OBS PLATFORMS.
WITH PASSAGE OF COLD FRONT...WINDS WILL DIMINISH SOME OVERNIGHT.
HOWEVER...WIND SWITCH TO THE WSW ALONG WITH PRES RISE HEADING FOR
WRN LAKE SUPERIOR COULD LEAD TO A SHORT PERIOD OF GALE FORCE GUSTS
IN THE AREA BTWN ISLE ROYALE AND THE KEWEENAW. WEAKENING PRES
GRADIENT WILL LEAD TO WINDS DIMINISHING TO MOSTLY 15-25KT TUE.
ACTIVE PERIOD ON LAKE SUPERIOR CONTINUES TUESDAY NIGHT AS NORTHWEST
WINDS INCREASE TO 30KTS BEHIND THE SURFACE TROUGH MOVING ACROSS THE
LAKE ON TUESDAY. THERE COULD BE SOME GALE FORCE GUSTS TO 35KTS OVER
THE EASTERN LAKE TUESDAY NIGHT INTO WEDNESDAY...BEFORE A HIGH
PRESSURE RIDGE DECREASES WINDS BELOW 25KTS. THE NEXT SYSTEM WILL MOVE
ACROSS LAKE SUPERIOR LATE WEDNESDAY NIGHT INTO THURSDAY. THIS WILL
AGAIN PRODUCE WEST GUSTS TO 30-35KTS ON THURSDAY AND THURSDAY
EVENING. WEAKER WINDS WILL PREVAIL ON FRIDAY AS HIGH PRESSURE SLIDES
OVER THE GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 AM EDT TUESDAY FOR MIZ006-007-013-014-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LSZ265>267.
GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LSZ248>251.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT TUESDAY FOR LMZ248-250.
GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LMZ221.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON/SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 PM EDT SUN OCT 7 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SUN OCT 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FULL LATITUDE UPR
TROF OVER ERN NAMERICA...WITH NW FLOW ALF OVER THE UPR GRT LKS. WITH
H85 TEMPS ARND -7C OVER LK SUP /VS WATER TEMPS RANGING FM 6-7C OVER
THE W TO 11-12C OVER THE E/...A WEAK SHRTWV MOVING THRU THE UPR
LKS...AND ADEQUATE LLVL MSTR PER THE 00Z APX RAOB...SOME LK EFFECT
-SHRA MIXED WITH SN CONTINUE OVER MAINLY THE E HALF OF THE LK WHERE
INSTABILITY REMAINS GREATEST. PERSISTENT CNVGC SHOWN BY WIND OBS
OVER THE E HALF OF THE LAKE ARE ALSO HELPING TO MAINTAIN THE
COVERAGE/INTENSITY OF THIS PCPN IN THAT AREA. OVER THE W...MORE ACYC
LLVL FLOW ASSOCIATED WITH SFC RDG EXTENDING FM HI CENTER IN THE
SCNTRL PLAINS TOWARD THE UPR MIDWEST...COOLER WATERS...AS WELL AS
SOMEWHAT DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB ARE CONSPIRING TO
LIMIT THE ACTIVITY OVER THAT PART OF THE LAKE. ALTHOUGH DRIER AIR
OVER THE NRN PLAINS PER THE 00Z BISMARCK RAOB IS SHIFTING TO THE E
IN THE WLY FLOW ON THE NRN FLANK OF THE HI CENTER IN THE SCNTRL
PLAINS...THERE IS A GOOD DEAL OF MID/HI CLD EXTENDING FM ARND LK
WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH ISENTROPIC ASCENT ON
THE 290-295K SFCS /H7-575/.
TODAY...SHORT TERM MODELS ARE IN GOOD AGREEMENT SHOWING LARGER SCALE
FLOW OVER THE ENTIRE CWA SHIFTING TO THE W AS HI PRES OVER THE
SCNTRL PLAINS SHIFTS TOWARD THE OH RIVER VALLEY...WHICH SHOULD
WEAKEN THE LLVL CNVGC NOW PRESENT OVER THE E HALF AND ADVECT WARMER
H85 TEMPS/DRIER LLVL AIR TO THE W OVER THE CWA. THESE TRENDS WL TEND
TO STEADILY WEAKEN THE ONGOING LK EFFECT PCPN NOW IMPACTING MAINLY
THE E HALF OF THE CWA. THE ARRIVAL OF THE DRIER AIR WL ALSO RESULT
IN MORE SUNSHINE...WHICH WL BE DIMMED AT TIMES BY THE BKN HIER CLDS
DRIFTING INTO THE AREA FM THE NW. MIXING TO H8 ON NAM/GFS FCST SDNGS
YIELDS HI TEMPS MAINLY 45-50...EXCEPT IN THE LO 50S WHERE THE INCRSG
W WIND DOWNSLOPES OVER THE CENTRAL.
SUN NGT...AS NEXT SHRTWV/SFC LO DIGS SEWD THRU SCNTRL CANADA TO NEAR
LK WINNIPEG AND SFC HI PRES SHIFTS INTO THE OH RIVER VALLEY BY
12Z...A STRENGTHENING WSW FLOW WL DVLP OVER THE UPR LKS WITH H925
WINDS INCRSG UP TO 25-35 KTS BY 12Z MON. ALTHOUGH SOME MID/HI CLDS
ASSOCIATED WITH THE ISENTROPIC ASCENT ON THE 290K SFC WL BE OVER THE
UPR LKS...THESE CLDS WL BE RATHER THIN. PWATS AS LO AS 0.25-0.30
INCH INDICATE TEMPS WL STILL FALL FAIRLY SHARPLY OVER THOSE INTERIOR
LOCATIONS ESPECIALLY OVER THE SCNTRL THAT CAN DECOUPLE BEFORE THE
H925 FLOW STRENGTHENS TOO MUCH OVERNGT. LOCATIONS NEAR LK SUP SHOULD
BE WARMEST WITH DOWNSLOPE FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 503 AM EDT SUN OCT 7 2012
BY MONDAY MORNING THE UPPER GREAT LAKES WILL BE COMPLETELY WITHIN A
LARGE 500MB TROUGH THAT WILL ENCOMPASS ALL BUT THE FAR SW CORNER OF
THE NATION...EXTENDING FROM THE MAIN LOW OVER N CANADA THROUGH
HUDSON BAY.
FCST MODELS AGREE WITH THE ENHANCEMENT IN THE MAIN THROUGH SET UP
FROM S HUDSON BAY THROUGH CENTRAL SASKATCHEWAN BY MONDAY
AFTERNOON...SHIFTING TO CENTRAL MN BY DAYBREAK TUESDAY...AND SLOWLY
ACROSS LAKE SUPERIOR/UPPER MI TUESDAY. THE APEX OF THE TROUGH SHOULD
BE ACROSS THE CENTER OF THE CWA BY AT 12Z WEDNESDAY...BEFORE PUSHING
TO THE LOWER GREAT LAKES DURING THE DAY.
THE PROGRESSIVELY S SINKING /RUN TO RUN COMPARISON OVER THE PAST
COUPLE OF DAYS/ SFC LOW OVER S MANITOBA AND ND MONDAY MORNING WILL
RESULT IN INCREASED SW WINDS ACROSS THE UPPER GREAT LAKES. THE TRACK
OF THE SFC LOW IS STILL IN QUESTION...WITH THE 06/18Z RUN OF THE GFS
AROUND 6HRS FASTER THAN THE NAM/ECMWF/CANADIAN SOLUTIONS. THE 07/00Z
RUN OF THE GFS IS MUCH FARTHER TO THE N...BUT STILL TRACKING A BIT
FAST. THE TRACK WILL LIKELY BRING THE SFC LOW OVER W-CENTRAL LAKE
SUPERIOR BY 06Z TUESDAY...BEFORE SLIDING NE TO JAMES BAY BY 00Z
WEDNESDAY. GIVEN THIS TRACK...THE STRONGEST WINDS WILL LIKELY BE
AHEAD OF THE SYSTEM /OUT OF THE SW MONDAY THROUGH MONDAY EVENING/.
TEMPERATURE WISE...INCREASED DOWNSLOPE S FLOW WILL BE COUNTERACTED
SLIGHTLY BY ADDITIONAL CLOUD COVER MONDAY AFTERNOON NEAR LAKE
SUPERIOR.
N/NW FLOW WILL RETURN TUESDAY NIGHT BEHIND THE EXITING SFC LOW.
850MB TEMPS OF -5 TO -8C MAY NOT BE ENOUGH TO CREATE MUCH MORE THAN
ENHANCED CLOUD COVER NEAR THE LAKE SUPERIOR SHORELINE TUESDAY NIGHT
INTO WEDNESDAY. HIGH PRESSURE NUDGING IN FROM THE CENTRAL PLAINS
WEDNESDAY SHOULD HELP IN PUSHING MUCH OF THE LOW LEVEL MOISTURE TO
OUR EAST. IT WILL NOT BE QUITE THAT SIMPLE THOUGH...WITH NW FLOW
ALOFT AND A CONTINUATION OF SMALLER SCALE WAVES BRINGING IN
ADDITIONAL MOISTURE.
THURSDAY THROUGH FRIDAY...
YET ANOTHER WAVE LOOKS TO SLIDE IN FROM THE NW THURSDAY OR THURSDAY
NIGHT. THE 06/12Z ECMWF WAS APPROX 12 HRS SLOWER THAN THE 06/18Z RUN
OF THE GFS WITH THIS WEAKER TROUGH. THE 07/00Z RUNS HAVE NEARLY
CORRECTED THIS ISSUE...WITH ONLY MINOR DIFFERENCES. STILL HAVE W TO
NW GALES TO 35KTS POSSIBLE OVER CENTRAL AND E LAKE SUPERIOR THURSDAY
AFTERNOON AND EVENING.
FRIDAY NIGHT THROUGH SATURDAY...
HIGH PRESSURE WILL ATTEMPT TO BUILD IN AT 500MB...WITH LITTLE MORE
THAN ZONAL FLOW BEING THE RESULT...AS THE NEXT LOW NEAR THE
4-CORNERS GETS SWEPT UP IN THE MAIN FLOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 137 PM EDT SUN OCT 7 2012
INTERVALS OF MID/HI CLDS THROUGH MIDDAY MONDAY BUT VFR CONDITIONS WL
PREVAIL AT ALL 3 SITES WITH W WIND ADVECTING DRY LLVL AIR INTO THE
UPR GRT LKS. PLAN ON SOME MARGINAL LLWS CONDITIONS TNGT WITH DVLPG
RADIATION INVRN/DECOUPLING SFC WIND. SOME RAIN SHOWERS ARE EXPECTED
LATER MONDAY AFTERNOON BEYOND THIS TAF PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT SUN OCT 7 2012
AS A HI PRES RIDGE BUILDS TOWARD THE OHIO RIVER VALLEY THRU TONIGHT
AND LO PRES MOVES SE THRU CANADA TOWARD MINNESOTA...EXPECT A
STRENGTHENING W WIND OVER LAKE SUPERIOR. AS IS TYPICAL FOR THIS
FLOW...THE STRONGEST WINDS UP TO 30 KTS ARE MOST LIKELY IN THE AREA
BETWEEN THE KEWEENAW AND ISLE ROYALE...WHERE SOME GALE FORCE GUSTS
TO 35 KTS ARE POSSIBLE LATER TODAY.
LOW PRESSURE NEARING FROM SOUTH CENTRAL CANADA WILL RESULT IN
INCREASING SOUTHWESTERLY WINDS MONDAY /WITH S GALES TO 35KTS OVER
PORTIONS OF E LAKE SUPERIOR MONDAY INTO MONDAY EVENING/. EXPECT THE
LOW TO TRACK FROM ND AND SOUTHERN MANITOBA TO W LS BY LATE MONDAY
AFTERNOON INTO MONDAY EVENING. THE LOW WILL PUSH NE TUESDAY...AS
ANOTHER DRYING HIGH PRESSURE SYSTEM ATTEMPTS TO BUILD IN FROM THE
CENTRAL PLAINS. GUSTS WILL DIMINISH TO 20-25KTS TUESDAY NIGHT. YET
ANOTHER LOW SHOULD SKIRT ACROSS OR JUST NORTH OF LAKE SUPERIOR
WEDNESDAY NIGHT...WITH WINDS BRIEFLY INCREASING WITH GUSTS NEARING
30KTS AGAIN WEDNESDAY OUT OF THE NW. HIGH PRESSURE SHOULD FINALLY
WIN OUT TOWARD THE END OF THE WORK WEEK...WITH ANOTHER ROUND OF WEST
TO NORTHWEST GALES TO 35KTS POSSIBLE THURSDAY AFTERNOON AND
EVENING...IN BETWEEN NEARING HIGH PRESSURE TO OUR W AND EXITING LOW
PRESSURE TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ267.
LAKE MICHIGAN...
GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR
LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...JLA
MARINE...KC/KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
720 AM EDT SUN OCT 7 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SUN OCT 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FULL LATITUDE UPR
TROF OVER ERN NAMERICA...WITH NW FLOW ALF OVER THE UPR GRT LKS. WITH
H85 TEMPS ARND -7C OVER LK SUP /VS WATER TEMPS RANGING FM 6-7C OVER
THE W TO 11-12C OVER THE E/...A WEAK SHRTWV MOVING THRU THE UPR
LKS...AND ADEQUATE LLVL MSTR PER THE 00Z APX RAOB...SOME LK EFFECT
-SHRA MIXED WITH SN CONTINUE OVER MAINLY THE E HALF OF THE LK WHERE
INSTABILITY REMAINS GREATEST. PERSISTENT CNVGC SHOWN BY WIND OBS
OVER THE E HALF OF THE LAKE ARE ALSO HELPING TO MAINTAIN THE
COVERAGE/INTENSITY OF THIS PCPN IN THAT AREA. OVER THE W...MORE ACYC
LLVL FLOW ASSOCIATED WITH SFC RDG EXTENDING FM HI CENTER IN THE
SCNTRL PLAINS TOWARD THE UPR MIDWEST...COOLER WATERS...AS WELL AS
SOMEWHAT DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB ARE CONSPIRING TO
LIMIT THE ACTIVITY OVER THAT PART OF THE LAKE. ALTHOUGH DRIER AIR
OVER THE NRN PLAINS PER THE 00Z BISMARCK RAOB IS SHIFTING TO THE E
IN THE WLY FLOW ON THE NRN FLANK OF THE HI CENTER IN THE SCNTRL
PLAINS...THERE IS A GOOD DEAL OF MID/HI CLD EXTENDING FM ARND LK
WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH ISENTROPIC ASCENT ON
THE 290-295K SFCS /H7-575/.
TODAY...SHORT TERM MODELS ARE IN GOOD AGREEMENT SHOWING LARGER SCALE
FLOW OVER THE ENTIRE CWA SHIFTING TO THE W AS HI PRES OVER THE
SCNTRL PLAINS SHIFTS TOWARD THE OH RIVER VALLEY...WHICH SHOULD
WEAKEN THE LLVL CNVGC NOW PRESENT OVER THE E HALF AND ADVECT WARMER
H85 TEMPS/DRIER LLVL AIR TO THE W OVER THE CWA. THESE TRENDS WL TEND
TO STEADILY WEAKEN THE ONGOING LK EFFECT PCPN NOW IMPACTING MAINLY
THE E HALF OF THE CWA. THE ARRIVAL OF THE DRIER AIR WL ALSO RESULT
IN MORE SUNSHINE...WHICH WL BE DIMMED AT TIMES BY THE BKN HIER CLDS
DRIFTING INTO THE AREA FM THE NW. MIXING TO H8 ON NAM/GFS FCST SDNGS
YIELDS HI TEMPS MAINLY 45-50...EXCEPT IN THE LO 50S WHERE THE INCRSG
W WIND DOWNSLOPES OVER THE CENTRAL.
SUN NGT...AS NEXT SHRTWV/SFC LO DIGS SEWD THRU SCNTRL CANADA TO NEAR
LK WINNIPEG AND SFC HI PRES SHIFTS INTO THE OH RIVER VALLEY BY
12Z...A STRENGTHENING WSW FLOW WL DVLP OVER THE UPR LKS WITH H925
WINDS INCRSG UP TO 25-35 KTS BY 12Z MON. ALTHOUGH SOME MID/HI CLDS
ASSOCIATED WITH THE ISENTROPIC ASCENT ON THE 290K SFC WL BE OVER THE
UPR LKS...THESE CLDS WL BE RATHER THIN. PWATS AS LO AS 0.25-0.30
INCH INDICATE TEMPS WL STILL FALL FAIRLY SHARPLY OVER THOSE INTERIOR
LOCATIONS ESPECIALLY OVER THE SCNTRL THAT CAN DECOUPLE BEFORE THE
H925 FLOW STRENGTHENS TOO MUCH OVERNGT. LOCATIONS NEAR LK SUP SHOULD
BE WARMEST WITH DOWNSLOPE FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 503 AM EDT SUN OCT 7 2012
BY MONDAY MORNING THE UPPER GREAT LAKES WILL BE COMPLETELY WITHIN A
LARGE 500MB TROUGH THAT WILL ENCOMPASS ALL BUT THE FAR SW CORNER OF
THE NATION...EXTENDING FROM THE MAIN LOW OVER N CANADA THROUGH
HUDSON BAY.
FCST MODELS AGREE WITH THE ENHANCEMENT IN THE MAIN THROUGH SET UP
FROM S HUDSON BAY THROUGH CENTRAL SASKATCHEWAN BY MONDAY
AFTERNOON...SHIFTING TO CENTRAL MN BY DAYBREAK TUESDAY...AND SLOWLY
ACROSS LAKE SUPERIOR/UPPER MI TUESDAY. THE APEX OF THE TROUGH SHOULD
BE ACROSS THE CENTER OF THE CWA BY AT 12Z WEDNESDAY...BEFORE PUSHING
TO THE LOWER GREAT LAKES DURING THE DAY.
THE PROGRESSIVELY S SINKING /RUN TO RUN COMPARISON OVER THE PAST
COUPLE OF DAYS/ SFC LOW OVER S MANITOBA AND ND MONDAY MORNING WILL
RESULT IN INCREASED SW WINDS ACROSS THE UPPER GREAT LAKES. THE TRACK
OF THE SFC LOW IS STILL IN QUESTION...WITH THE 06/18Z RUN OF THE GFS
AROUND 6HRS FASTER THAN THE NAM/ECMWF/CANADIAN SOLUTIONS. THE 07/00Z
RUN OF THE GFS IS MUCH FARTHER TO THE N...BUT STILL TRACKING A BIT
FAST. THE TRACK WILL LIKELY BRING THE SFC LOW OVER W-CENTRAL LAKE
SUPERIOR BY 06Z TUESDAY...BEFORE SLIDING NE TO JAMES BAY BY 00Z
WEDNESDAY. GIVEN THIS TRACK...THE STRONGEST WINDS WILL LIKELY BE
AHEAD OF THE SYSTEM
/OUT OF THE SW MONDAY THROUGH MONDAY EVENING/.
TEMPERATURE WISE...INCREASED DOWNSLOPE S FLOW WILL BE COUNTERACTED
SLIGHTLY BY ADDITIONAL CLOUD COVER MONDAY AFTERNOON NEAR LAKE
SUPERIOR.
N/NW FLOW WILL RETURN TUESDAY NIGHT BEHIND THE EXITING SFC LOW.
850MB TEMPS OF -5 TO -8C MAY NOT BE ENOUGH TO CREATE MUCH MORE THAN
ENHANCED CLOUD COVER NEAR THE LAKE SUPERIOR SHORELINE TUESDAY NIGHT
INTO WEDNESDAY. HIGH PRESSURE NUDGING IN FROM THE CENTRAL PLAINS
WEDNESDAY SHOULD HELP IN PUSHING MUCH OF THE LOW LEVEL MOISTURE TO
OUR EAST. IT WILL NOT BE QUITE THAT SIMPLE THOUGH...WITH NW FLOW
ALOFT AND A CONTINUATION OF SMALLER SCALE WAVES BRINGING IN
ADDITIONAL MOISTURE.
THURSDAY THROUGH FRIDAY...
YET ANOTHER WAVE LOOKS TO SLIDE IN FROM THE NW THURSDAY OR THURSDAY
NIGHT. THE 06/12Z ECMWF WAS APPROX 12 HRS SLOWER THAN THE 06/18Z RUN
OF THE GFS WITH THIS WEAKER TROUGH. THE 07/00Z RUNS HAVE NEARLY
CORRECTED THIS ISSUE...WITH ONLY MINOR DIFFERENCES. STILL HAVE W TO
NW GALES TO 35KTS POSSIBLE OVER CENTRAL AND E LAKE SUPERIOR THURSDAY
AFTERNOON AND EVENING.
FRIDAY NIGHT THROUGH SATURDAY...
HIGH PRESSURE WILL ATTEMPT TO BUILD IN AT 500MB...WITH LITTLE MORE
THAN ZONAL FLOW BEING THE RESULT...AS THE NEXT LOW NEAR THE
4-CORNERS GETS SWEPT UP IN THE MAIN FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 719 AM EDT SUN OCT 7 2012
WITH SOME DAYTIME HEATING...EXPECT STRENGTHENING W WIND TO TURN
GUSTY AT ALL 3 TAF SITES...ESPECIALLY AT THE MORE EXPOSED CMX
LOCATION. DESPITE SOME INCRSG MID/HI CLDS...VFR CONDITIONS WL
PREVAIL AT ALL 3 SITES WITH W WIND ADVECTING DRY LLVL AIR INTO THE
UPR GRT LKS. PLAN ON SOME MARGINAL LLWS CONDITIONS TNGT WITH DVLPG
RADIATION INVRN/DECOUPLING SFC WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT SUN OCT 7 2012
AS A HI PRES RIDGE BUILDS TOWARD THE OHIO RIVER VALLEY THRU TONIGHT
AND LO PRES MOVES SE THRU CANADA TOWARD MINNESOTA...EXPECT A
STRENGTHENING W WIND OVER LAKE SUPERIOR. AS IS TYPICAL FOR THIS
FLOW...THE STRONGEST WINDS UP TO 30 KTS ARE MOST LIKELY IN THE AREA
BETWEEN THE KEWEENAW AND ISLE ROYALE...WHERE SOME GALE FORCE GUSTS
TO 35 KTS ARE POSSIBLE LATER TODAY.
LOW PRESSURE NEARING FROM SOUTH CENTRAL CANADA WILL RESULT IN
INCREASING SOUTHWESTERLY WINDS MONDAY /WITH S GALES TO 35KTS OVER
PORTIONS OF E LAKE SUPERIOR MONDAY INTO MONDAY EVENING/. EXPECT THE
LOW TO TRACK FROM ND AND SOUTHERN MANITOBA TO W LS BY LATE MONDAY
AFTERNOON INTO MONDAY EVENING. THE LOW WILL PUSH NE TUESDAY...AS
ANOTHER DRYING HIGH PRESSURE SYSTEM ATTEMPTS TO BUILD IN FROM THE
CENTRAL PLAINS. GUSTS WILL DIMINISH TO 20-25KTS TUESDAY NIGHT. YET
ANOTHER LOW SHOULD SKIRT ACROSS OR JUST NORTH OF LAKE SUPERIOR
WEDNESDAY NIGHT...WITH WINDS BRIEFLY INCREASING WITH GUSTS NEARING
30KTS AGAIN WEDNESDAY OUT OF THE NW. HIGH PRESSURE SHOULD FINALLY
WIN OUT TOWARD THE END OF THE WORK WEEK...WITH ANOTHER ROUND OF WEST
TO NORTHWEST GALES TO 35KTS POSSIBLE THURSDAY AFTERNOON AND
EVENING...IN BETWEEN NEARING HIGH PRESSURE TO OUR W AND EXITING LOW
PRESSURE TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ267.
LAKE MICHIGAN...
GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR
LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC/KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 AM EDT SUN OCT 7 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SUN OCT 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FULL LATITUDE UPR
TROF OVER ERN NAMERICA...WITH NW FLOW ALF OVER THE UPR GRT LKS. WITH
H85 TEMPS ARND -7C OVER LK SUP /VS WATER TEMPS RANGING FM 6-7C OVER
THE W TO 11-12C OVER THE E/...A WEAK SHRTWV MOVING THRU THE UPR
LKS...AND ADEQUATE LLVL MSTR PER THE 00Z APX RAOB...SOME LK EFFECT
-SHRA MIXED WITH SN CONTINUE OVER MAINLY THE E HALF OF THE LK WHERE
INSTABILITY REMAINS GREATEST. PERSISTENT CNVGC SHOWN BY WIND OBS
OVER THE E HALF OF THE LAKE ARE ALSO HELPING TO MAINTAIN THE
COVERAGE/INTENSITY OF THIS PCPN IN THAT AREA. OVER THE W...MORE ACYC
LLVL FLOW ASSOCIATED WITH SFC RDG EXTENDING FM HI CENTER IN THE
SCNTRL PLAINS TOWARD THE UPR MIDWEST...COOLER WATERS...AS WELL AS
SOMEWHAT DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB ARE CONSPIRING TO
LIMIT THE ACTIVITY OVER THAT PART OF THE LAKE. ALTHOUGH DRIER AIR
OVER THE NRN PLAINS PER THE 00Z BISMARCK RAOB IS SHIFTING TO THE E
IN THE WLY FLOW ON THE NRN FLANK OF THE HI CENTER IN THE SCNTRL
PLAINS...THERE IS A GOOD DEAL OF MID/HI CLD EXTENDING FM ARND LK
WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH ISENTROPIC ASCENT ON
THE 290-295K SFCS /H7-575/.
TODAY...SHORT TERM MODELS ARE IN GOOD AGREEMENT SHOWING LARGER SCALE
FLOW OVER THE ENTIRE CWA SHIFTING TO THE W AS HI PRES OVER THE
SCNTRL PLAINS SHIFTS TOWARD THE OH RIVER VALLEY...WHICH SHOULD
WEAKEN THE LLVL CNVGC NOW PRESENT OVER THE E HALF AND ADVECT WARMER
H85 TEMPS/DRIER LLVL AIR TO THE W OVER THE CWA. THESE TRENDS WL TEND
TO STEADILY WEAKEN THE ONGOING LK EFFECT PCPN NOW IMPACTING MAINLY
THE E HALF OF THE CWA. THE ARRIVAL OF THE DRIER AIR WL ALSO RESULT
IN MORE SUNSHINE...WHICH WL BE DIMMED AT TIMES BY THE BKN HIER CLDS
DRIFTING INTO THE AREA FM THE NW. MIXING TO H8 ON NAM/GFS FCST SDNGS
YIELDS HI TEMPS MAINLY 45-50...EXCEPT IN THE LO 50S WHERE THE INCRSG
W WIND DOWNSLOPES OVER THE CENTRAL.
SUN NGT...AS NEXT SHRTWV/SFC LO DIGS SEWD THRU SCNTRL CANADA TO NEAR
LK WINNIPEG AND SFC HI PRES SHIFTS INTO THE OH RIVER VALLEY BY
12Z...A STRENGTHENING WSW FLOW WL DVLP OVER THE UPR LKS WITH H925
WINDS INCRSG UP TO 25-35 KTS BY 12Z MON. ALTHOUGH SOME MID/HI CLDS
ASSOCIATED WITH THE ISENTROPIC ASCENT ON THE 290K SFC WL BE OVER THE
UPR LKS...THESE CLDS WL BE RATHER THIN. PWATS AS LO AS 0.25-0.30
INCH INDICATE TEMPS WL STILL FALL FAIRLY SHARPLY OVER THOSE INTERIOR
LOCATIONS ESPECIALLY OVER THE SCNTRL THAT CAN DECOUPLE BEFORE THE
H925 FLOW STRENGTHENS TOO MUCH OVERNGT. LOCATIONS NEAR LK SUP SHOULD
BE WARMEST WITH DOWNSLOPE FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 503 AM EDT SUN OCT 7 2012
BY MONDAY MORNING THE UPPER GREAT LAKES WILL BE COMPLETELY WITHIN A
LARGE 500MB TROUGH THAT WILL ENCOMPASS ALL BUT THE FAR SW CORNER OF
THE NATION...EXTENDING FROM THE MAIN LOW OVER N CANADA THROUGH
HUDSON BAY.
FCST MODELS AGREE WITH THE ENHANCEMENT IN THE MAIN THROUGH SET UP
FROM S HUDSON BAY THROUGH CENTRAL SASKATCHEWAN BY MONDAY
AFTERNOON...SHIFTING TO CENTRAL MN BY DAYBREAK TUESDAY...AND SLOWLY
ACROSS LAKE SUPERIOR/UPPER MI TUESDAY. THE APEX OF THE TROUGH SHOULD
BE ACROSS THE CENTER OF THE CWA BY AT 12Z WEDNESDAY...BEFORE PUSHING
TO THE LOWER GREAT LAKES DURING THE DAY.
THE PROGRESSIVELY S SINKING /RUN TO RUN COMPARISON OVER THE PAST
COUPLE OF DAYS/ SFC LOW OVER S MANITOBA AND ND MONDAY MORNING WILL
RESULT IN INCREASED SW WINDS ACROSS THE UPPER GREAT LAKES. THE TRACK
OF THE SFC LOW IS STILL IN QUESTION...WITH THE 06/18Z RUN OF THE GFS
AROUND 6HRS FASTER THAN THE NAM/ECMWF/CANADIAN SOLUTIONS. THE 07/00Z
RUN OF THE GFS IS MUCH FARTHER TO THE N...BUT STILL TRACKING A BIT
FAST. THE TRACK WILL LIKELY BRING THE SFC LOW OVER W-CENTRAL LAKE
SUPERIOR BY 06Z TUESDAY...BEFORE SLIDING NE TO JAMES BAY BY 00Z
WEDNESDAY. GIVEN THIS TRACK...THE STRONGEST WINDS WILL LIKELY BE
AHEAD OF THE SYSTEM
/OUT OF THE SW MONDAY THROUGH MONDAY EVENING/.
TEMPERATURE WISE...INCREASED DOWNSLOPE S FLOW WILL BE COUNTERACTED
SLIGHTLY BY ADDITIONAL CLOUD COVER MONDAY AFTERNOON NEAR LAKE
SUPERIOR.
N/NW FLOW WILL RETURN TUESDAY NIGHT BEHIND THE EXITING SFC LOW.
850MB TEMPS OF -5 TO -8C MAY NOT BE ENOUGH TO CREATE MUCH MORE THAN
ENHANCED CLOUD COVER NEAR THE LAKE SUPERIOR SHORELINE TUESDAY NIGHT
INTO WEDNESDAY. HIGH PRESSURE NUDGING IN FROM THE CENTRAL PLAINS
WEDNESDAY SHOULD HELP IN PUSHING MUCH OF THE LOW LEVEL MOISTURE TO
OUR EAST. IT WILL NOT BE QUITE THAT SIMPLE THOUGH...WITH NW FLOW
ALOFT AND A CONTINUATION OF SMALLER SCALE WAVES BRINGING IN
ADDITIONAL MOISTURE.
THURSDAY THROUGH FRIDAY...
YET ANOTHER WAVE LOOKS TO SLIDE IN FROM THE NW THURSDAY OR THURSDAY
NIGHT. THE 06/12Z ECMWF WAS APPROX 12 HRS SLOWER THAN THE 06/18Z RUN
OF THE GFS WITH THIS WEAKER TROUGH. THE 07/00Z RUNS HAVE NEARLY
CORRECTED THIS ISSUE...WITH ONLY MINOR DIFFERENCES. STILL HAVE W TO
NW GALES TO 35KTS POSSIBLE OVER CENTRAL AND E LAKE SUPERIOR THURSDAY
AFTERNOON AND EVENING.
FRIDAY NIGHT THROUGH SATURDAY...
HIGH PRESSURE WILL ATTEMPT TO BUILD IN AT 500MB...WITH LITTLE MORE
THAN ZONAL FLOW BEING THE RESULT...AS THE NEXT LOW NEAR THE
4-CORNERS GETS SWEPT UP IN THE MAIN FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 123 AM EDT SUN OCT 7 2012
COMBINATION OF WINDS BACKING TO THE WEST AND SLIGHT WARMING ALOFT
HAS GENERALLY PUT AN END TO LAKE EFFECT SHOWERS AT SAW/IWD. SOME
-SHSN MAY CONTINUE AT CMX FOR THE NEXT COUPLE OF HOURS WITH UPSLOPE W
WIND...AND MVFR CONDITIONS ARE POSSIBLE EARLY THIS MORNING. DRIER AIR
ADVECTING IN FM THE WEST HAS BROUGHT CIGS ABV VFR AT SAW/IWD AND NOW
EXPECT VFR CONDITIONS TO CONTINUE THROUGH TAF FCST PD AT THESE
LOCATIONS AND AT CMX ONCE THE -SHSN END BY AROUND SUNRISE. ANOTHER
SURFACE TROUGH WILL APPROACH UPPER MICHIGAN SUNDAY...LEADING TO
INCREASING SWRLY WINDS AND MID- HIGH CLOUDS DURING THE MORNING HOURS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT SUN OCT 7 2012
AS A HI PRES RIDGE BUILDS TOWARD THE OHIO RIVER VALLEY THRU TONIGHT
AND LO PRES MOVES SE THRU CANADA TOWARD MINNESOTA...EXPECT A
STRENGTHENING W WIND OVER LAKE SUPERIOR. AS IS TYPICAL FOR THIS
FLOW...THE STRONGEST WINDS UP TO 30 KTS ARE MOST LIKELY IN THE AREA
BETWEEN THE KEWEENAW AND ISLE ROYALE...WHERE SOME GALE FORCE GUSTS
TO 35 KTS ARE POSSIBLE LATER TODAY.
LOW PRESSURE NEARING FROM SOUTH CENTRAL CANADA WILL RESULT IN
INCREASING SOUTHWESTERLY WINDS MONDAY /WITH S GALES TO 35KTS OVER
PORTIONS OF E LAKE SUPERIOR MONDAY INTO MONDAY EVENING/. EXPECT THE
LOW TO TRACK FROM ND AND SOUTHERN MANITOBA TO W LS BY LATE MONDAY
AFTERNOON INTO MONDAY EVENING. THE LOW WILL PUSH NE TUESDAY...AS
ANOTHER DRYING HIGH PRESSURE SYSTEM ATTEMPTS TO BUILD IN FROM THE
CENTRAL PLAINS. GUSTS WILL DIMINISH TO 20-25KTS TUESDAY NIGHT. YET
ANOTHER LOW SHOULD SKIRT ACROSS OR JUST NORTH OF LAKE SUPERIOR
WEDNESDAY NIGHT...WITH WINDS BRIEFLY INCREASING WITH GUSTS NEARING
30KTS AGAIN WEDNESDAY OUT OF THE NW. HIGH PRESSURE SHOULD FINALLY
WIN OUT TOWARD THE END OF THE WORK WEEK...WITH ANOTHER ROUND OF WEST
TO NORTHWEST GALES TO 35KTS POSSIBLE THURSDAY AFTERNOON AND
EVENING...IN BETWEEN NEARING HIGH PRESSURE TO OUR W AND EXITING LOW
PRESSURE TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ267.
LAKE MICHIGAN...
GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR
LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS
MARINE...KC/KF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
255 PM EDT SUN OCT 7 2012
.SYNOPSIS...
COOL AND DRY WEATHER IS EXPECTED THROUGH EARLY AFTERNOON. RAIN
WILL OVERSPREAD THE AREA BY LATE TODAY BEFORE ENDING EARLY
TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT AND THIS MAY ALLOW FOR
SOME AREAS OF FROST TO FORM BY EARLY MONDAY MORNING. MOSTLY DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE OUR NEXT SHOT AT
WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
HV UPDATED GRIDS TO RMV POPS ACRS THE FAVORED LK EFFECT LOCATIONS
AS SHOWERS HV WEAKENED RAPIDLY THIS MRNG. HV ALSO RMVD SLGT CHC
POPS OVR THE SE AFT 18Z AS AIRMASS WL LKLY TAKE AWHILE TO SATURATE
DOWN, WITH MAINLY VIRGA EXPECTED BTWN 18Z-21Z. H5 TROF WL APPRCH
FM THE WEST AFT 21Z, RESULTING IN WIDESPREAD PCPN BREAKING OUT
ACRS THE CWA.
HV TWEAKED HRLY T/TD GRIDS TO COME INTO LINE WITH CURRENT OBS. WL
EVALUATE POTENTIAL FOR FROST/FREEZE TONIGHT WITH LATEST MODEL
DATA.
PREVIOUS DISCUSSIONS BLO...
700 AM UPDATE...
THE BAND OF LAKE EFFECT RAIN EAST OF LAKE ONTARIO IS FINALLY
SHOWING A SOUTHWARD PUSH WHILE WEAKENING RAPIDLY. WILL CONFINE
CHANCE POPS TO NORTH CENTRAL ONEIDA COUNTY AND EXTREME NORTHERN
ONONDAGA COUNTY THROUGH 15Z BEFORE KEEPING A DRY FORECAST. A
DEVELOPING AREA OF RAIN OVER SOUTH CENTRAL PA STILL LOOKS TO
SKIRT JUST SOUTHEAST OF OUR CWA BUT STILL FEEL SLIGHT CHANCE POPS
PRUDENT FOR NEPA AS A BUFFER. STILL LOOKING AT THE MAIN THREAT OF
RAIN TO COME AFTER 21Z TODAY WITH THE DISTURBANCE MOVING THROUGH
IL.
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SLIDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AN UNSETTLED EXTENDED TIMEFRAME CONTINUES TO TAKE SHAPE THIS
AFTERNOON AS REGION WILL RESIDE UNDER THE ACTIVE POLAR JET THROUGH
A GOOD PORTION OF THE PERIOD. THAT SAID...EXPECT ONGOING LAKE
EFFECT SHWR ACTIVITY LATE WED/EARLY THU ACROSS THE SOUTHERN TUG
HILL AS REGION WILL RESIDE ON A POST FRONTAL AIRMASS. NEXT
NORTHERN STREAM TROUGH EXPECTED TO DROP SOUTH ACROSS THE AREA THU
NIGHT/EARLY FRI WHICH WILL LEAD TO BELOW NORMAL TEMPS BY FRI AS
COOL CANADIAN HIGH PRESSURE TEMPORARILY SETTLES ACROSS THE REGION.
MODEL PROGGED H85 TEMPS APPROACH -6C BY FRI AFTERNOON AND THUS
EXPECT THE REGENERATION OF LAKE EFFECT SHWRS SOUTHEAST OF LAKE
ONTARIO. BEYOND THIS...STRONG WARM AIR ADVECTION EXPECTED BY THE
BEGINNING OF THE WEEKEND AS CENTRAL PLAINS DISTURBANCE BEGINS
LIFTING NORTH TOWARDS THE CENTRAL GREAT LAKES. FOR NOW...BEST
CHANCES OF WARM ADVECTION SHWRS EXPECTED ON SATURDAY AS WARM FRONT
LIFTS NORTH TOWARDS THE AREA. THE SLOW MOVEMENT OF THE FEATURE MAY
THEN KEEP THE CHANCE FOR SHWRS IN THE FCST THROUGH THE CONCLUSION
OF THE PERIOD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
UPSTREAM RADARS SHOWING AN AREA OF -SHRA ACTIVITY ASSOCIATED WITH
A SHORTWAVE TROUGH HEADING TOWARDS OUR REGION EARLY THIS AFTERNOON.
EXPECT THIS ACTIVITY TO MOVE IN AFTER 20Z WITH ALL TERMINALS
EXPECTED TO FALL TO MVFR THRESHOLDS AS MAIN PRECIP SHIELD PASSES.
SOME POTENTIAL FOR SHORT DURATION IFR CIGS AT BOTH ITH AND BGM AS
THIS ACTIVITY ROLES THROUGH...HOWEVER CONFIDENCE AT THIS TIME IS
NOT HIGH ENOUGH TO INCLUDE IN THE CURRENT FCST. ACTIVITY WILL
QUICKLY EXIT TOWARDS THE NORTHEAST AFTER 02-03Z TIME FRAME WITH
LAKE EFFECT SHWRS THEN EXPECTED TO DEVELOP SOUTHEAST OF LAKE
ONTARIO AFTER 04Z. 280-290 FLOW WILL LIKELY RESULT IN LAKE CLOUDS
AND POSSIBLE SHWR ACTIVITY AT RME...WITH LAKE CLOUDS ALSO POSSIBLE
AT SYR. FURTHER SOUTH...FCST MODELS SUGGEST CLEARING WILL OCCUR
AFTER 06Z AT ELM/BGM/AVP AND POSSIBLY ITH. WITH MOIST LOW-LEVEL
CONDITIONS ASSOCIATED WITH THIS AFTERNOON/S RAINFALL...THE
POTENTIAL EXISTS FOR DEVELOPING IFR CIGS AND VSBYS AFTER 06Z AT
THE ABOVE SITES. BEYOND 13Z...BUILDING HIGH PRESSURE WILL BREAKUP
ANY LINGERING LOW CIGS WITH VFR CONDITIONS EXPECTED THROUGH THE
DURATION OF THE FCST.
OUTLOOK...
MON AFTERNOON/TUE...VFR.
WED...MAINLY VFR WITH POSSIBLE MVFR LATE IN DEVELOPING SHWRS.
THU...MOSTLY VFR WITH POSSIBLE MVFR AT RME IN DEVELOPING LAKE
EFFECT SHWRS.
FRI...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN/PVN
NEAR TERM...HEDEN/PVN
SHORT TERM...HEDEN
LONG TERM...CMG
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
151 PM EDT SUN OCT 7 2012
.SYNOPSIS...
COOL AND DRY WEATHER IS EXPECTED THROUGH EARLY AFTERNOON. RAIN
WILL OVERSPREAD THE AREA BY LATE TODAY BEFORE ENDING EARLY
TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT AND THIS MAY ALLOW FOR
SOME AREAS OF FROST TO FORM BY EARLY MONDAY MORNING. MOSTLY DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE OUR NEXT SHOT AT
WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
HV UPDATED GRIDS TO RMV POPS ACRS THE FAVORED LK EFFECT LOCATIONS
AS SHOWERS HV WEAKENED RAPIDLY THIS MRNG. HV ALSO RMVD SLGT CHC
POPS OVR THE SE AFT 18Z AS AIRMASS WL LKLY TAKE AWHILE TO SATURATE
DOWN, WITH MAINLY VIRGA EXPECTED BTWN 18Z-21Z. H5 TROF WL APPRCH
FM THE WEST AFT 21Z, RESULTING IN WIDESPREAD PCPN BREAKING OUT
ACRS THE CWA.
HV TWEAKED HRLY T/TD GRIDS TO COME INTO LINE WITH CURRENT OBS. WL
EVALUATE POTENTIAL FOR FROST/FREEZE TONIGHT WITH LATEST MODEL
DATA.
PREVIOUS DISCUSSIONS BLO...
700 AM UPDATE...
THE BAND OF LAKE EFFECT RAIN EAST OF LAKE ONTARIO IS FINALLY
SHOWING A SOUTHWARD PUSH WHILE WEAKENING RAPIDLY. WILL CONFINE
CHANCE POPS TO NORTH CENTRAL ONEIDA COUNTY AND EXTREME NORTHERN
ONONDAGA COUNTY THROUGH 15Z BEFORE KEEPING A DRY FORECAST. A
DEVELOPING AREA OF RAIN OVER SOUTH CENTRAL PA STILL LOOKS TO
SKIRT JUST SOUTHEAST OF OUR CWA BUT STILL FEEL SLIGHT CHANCE POPS
PRUDENT FOR NEPA AS A BUFFER. STILL LOOKING AT THE MAIN THREAT OF
RAIN TO COME AFTER 21Z TODAY WITH THE DISTURBANCE MOVING THROUGH
IL.
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SLIDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS MAINTAIN SOME CONSISTENCY WITH INDICATIONS OF
BEST SHOT OF PRECIPITATION ACROSS THE ENTIRE REGION DURING THIS
PERIOD TO BE IN THE WEDNESDAY TIME FRAME. THIS IS THEN LIKELY TO
BE FOLLOWED BY DEEPENING COLD AIR AND A MAINTAINED PRESENCE OF
SHOWER CHANCES TO THE LEE OF LAKE ONTARIO THROUGH THURSDAY WITH
IMPROVED WX OVER THE SOUTHERN HALF. ANOTHER WEAK UPPER TROF AND
SFC FRONT MAY SPREAD A QUICK SHOT OF SHOWERS INTO THE AREA ON
FRIDAY. A FAIRLY LARGE CENTER OF CONTINENTAL POLAR...FALL-
LIKE...HIGH PRESSURE WORKS IN FOR AT LEAST THE FIRST HALF OF NEXT
WEEKEND.
FOLLOWED THE HPC DAY 3-7 GUIDANCE CLOSELY WITH ONLY MINOR LOCAL
ADJUSTMENTS TO TEMPERATURES.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
UPSTREAM RADARS SHOWING AN AREA OF -SHRA ACTIVITY ASSOCIATED WITH
A SHORTWAVE TROUGH HEADING TOWARDS OUR REGION EARLY THIS AFTERNOON.
EXPECT THIS ACTIVITY TO MOVE IN AFTER 20Z WITH ALL TERMINALS
EXPECTED TO FALL TO MVFR THRESHOLDS AS MAIN PRECIP SHIELD PASSES.
SOME POTENTIAL FOR SHORT DURATION IFR CIGS AT BOTH ITH AND BGM AS
THIS ACTIVITY ROLES THROUGH...HOWEVER CONFIDENCE AT THIS TIME IS
NOT HIGH ENOUGH TO INCLUDE IN THE CURRENT FCST. ACTIVITY WILL
QUICKLY EXIT TOWARDS THE NORTHEAST AFTER 02-03Z TIME FRAME WITH
LAKE EFFECT SHWRS THEN EXPECTED TO DEVELOP SOUTHEAST OF LAKE
ONTARIO AFTER 04Z. 280-290 FLOW WILL LIKELY RESULT IN LAKE CLOUDS
AND POSSIBLE SHWR ACTIVITY AT RME...WITH LAKE CLOUDS ALSO POSSIBLE
AT SYR. FURTHER SOUTH...FCST MODELS SUGGEST CLEARING WILL OCCUR
AFTER 06Z AT ELM/BGM/AVP AND POSSIBLY ITH. WITH MOIST LOW-LEVEL
CONDITIONS ASSOCIATED WITH THIS AFTERNOON/S RAINFALL...THE
POTENTIAL EXISTS FOR DEVELOPING IFR CIGS AND VSBYS AFTER 06Z AT
THE ABOVE SITES. BEYOND 13Z...BUILDING HIGH PRESSURE WILL BREAKUP
ANY LINGERING LOW CIGS WITH VFR CONDITIONS EXPECTED THROUGH THE
DURATION OF THE FCST.
OUTLOOK...
MON AFTERNOON/TUE...VFR.
WED...MAINLY VFR WITH POSSIBLE MVFR LATE IN DEVELOPING SHWRS.
THU...MOSTLY VFR WITH POSSIBLE MVFR AT RME IN DEVELOPING LAKE
EFFECT SHWRS.
FRI...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN/PVN
NEAR TERM...HEDEN/PVN
SHORT TERM...HEDEN
LONG TERM...JAB
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1001 AM EDT SUN OCT 7 2012
.SYNOPSIS...
COOL AND DRY WEATHER IS EXPECTED THROUGH EARLY AFTERNOON. RAIN
WILL OVERSPREAD THE AREA BY LATE TODAY BEFORE ENDING EARLY
TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT AND THIS MAY ALLOW FOR
SOME AREAS OF FROST TO FORM BY EARLY MONDAY MORNING. MOSTLY DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE OUR NEXT SHOT AT
WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
HV UPDATED GRIDS TO RMV POPS ACRS THE FAVORED LK EFFECT LOCATIONS
AS SHOWERS HV WEAKENED RAPIDLY THIS MRNG. HV ALSO RMVD SLGT CHC
POPS OVR THE SE AFT 18Z AS AIRMASS WL LKLY TAKE AWHILE TO SATURATE
DOWN, WITH MAINLY VIRGA EXPECTED BTWN 18Z-21Z. H5 TROF WL APPRCH
FM THE WEST AFT 21Z, RESULTING IN WIDESPREAD PCPN BREAKING OUT
ACRS THE CWA.
HV TWEAKED HRLY T/TD GRIDS TO COME INTO LINE WITH CURRENT OBS. WL
EVALUATE POTENTIAL FOR FROST/FREEZE TONIGHT WITH LATEST MODEL
DATA.
PREVIOUS DISCUSSIONS BLO...
700 AM UPDATE...
THE BAND OF LAKE EFFECT RAIN EAST OF LAKE ONTARIO IS FINALLY
SHOWING A SOUTHWARD PUSH WHILE WEAKENING RAPIDLY. WILL CONFINE
CHANCE POPS TO NORTH CENTRAL ONEIDA COUNTY AND EXTREME NORTHERN
ONONDAGA COUNTY THROUGH 15Z BEFORE KEEPING A DRY FORECAST. A
DEVELOPING AREA OF RAIN OVER SOUTH CENTRAL PA STILL LOOKS TO
SKIRT JUST SOUTHEAST OF OUR CWA BUT STILL FEEL SLIGHT CHANCE POPS
PRUDENT FOR NEPA AS A BUFFER. STILL LOOKING AT THE MAIN THREAT OF
RAIN TO COME AFTER 21Z TODAY WITH THE DISTURBANCE MOVING THROUGH
IL.
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SLIDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS MAINTAIN SOME CONSISTENCY WITH INDICATIONS OF
BEST SHOT OF PRECIPITATION ACROSS THE ENTIRE REGION DURING THIS
PERIOD TO BE IN THE WEDNESDAY TIME FRAME. THIS IS THEN LIKELY TO
BE FOLLOWED BY DEEPENING COLD AIR AND A MAINTAINED PRESENCE OF
SHOWER CHANCES TO THE LEE OF LAKE ONTARIO THROUGH THURSDAY WITH
IMPROVED WX OVER THE SOUTHERN HALF. ANOTHER WEAK UPPER TROF AND
SFC FRONT MAY SPREAD A QUICK SHOT OF SHOWERS INTO THE AREA ON
FRIDAY. A FAIRLY LARGE CENTER OF CONTINENTAL POLAR...FALL-
LIKE...HIGH PRESSURE WORKS IN FOR AT LEAST THE FIRST HALF OF NEXT
WEEKEND.
FOLLOWED THE HPC DAY 3-7 GUIDANCE CLOSELY WITH ONLY MINOR LOCAL
ADJUSTMENTS TO TEMPERATURES.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
7 AM UPDATE...
MVFR CIGS POSSIBLE NEXT HOUR OR SO AT KRME DUE TO LAKE CLOUDS
OTHERWISE VFR THROUGH THIS AFTERNOON. HIGH CLOUDS AROUND 15KFT
LOWER TO 5KFT BY 20Z...WITH RAIN OVERSPREADING THE SOUTHERN
TERMINALS BY 22Z. UP NORTH SHOWERS POSSIBLE TOWARD 0Z...BUT NOT AS
LIKELY AS FARTHER SOUTH AND WILL ONLY COVER WITH A TEMPO GROUP.
ACROSS THE SOUTHERN TERMINALS...MVFR CIGS AND PERHAPS
VSBYS...APPEAR MOST LIKELY ABOUT 1 TO 2 HOURS AFTER THE ONSET OF
THE RAIN AND WILL PLAY AS A TEMPO GROUP THROUGH 04Z.
LATER TONIGHT THE TERMINALS WILL BEGIN TO CLEAR OUT. BASED ON THE
TIMING OF THE CLEARING...MVFR TO IFR CIGS AND VSBYS POSSIBLE
EVERYWHERE EXCEPT AT KSYR/KRME DUE TO VALLEY OR LOW STRATUS. MOST
CONFIDENT AT KELM.
NW WINDS OVERNIGHT 5 KTS OR LESS THROUGH THIS MORNING...THEN SW FLOW
LATER TODAY 5-10 KTS BECMG NWLY ACRS CNTRL NY LATE AFTERNOON.
NORTHWEST WINDS AROUND 5 KTS TONIGHT.
OUTLOOK...
MON TO TUE...VFR.
WED...VFR/MVFR. SOME SHOWERS.
THU...VFR. SOME LAKE EFFECT RAIN SHOWERS NORTH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN/PVN
NEAR TERM...HEDEN/PVN
SHORT TERM...HEDEN
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
709 AM EDT SUN OCT 7 2012
.SYNOPSIS...
LAKE EFFECT RAIN SHOWERS WILL BE POSSIBLE EARLY THIS MORNING
ACROSS CENTRAL NEW YORK...OTHERWISE DRY WEATHER IS EXPECTED
THROUGH EARLY AFTERNOON. RAIN WILL OVERSPREAD THE AREA BY LATE
TODAY BEFORE ENDING EARLY TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT
AND THIS MAY ALLOW FOR SOME AREAS OF FROST TO FORM BY EARLY MONDAY
MORNING. MOSTLY DRY WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE
OUR NEXT SHOT AT WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
700 AM UPDATE...
THE BAND OF LAKE EFFECT RAIN EAST OF LAKE ONTARIO IS FINALLY
SHOWING A SOUTHWARD PUSH WHILE WEAKENING RAPIDLY. WILL CONFINE
CHANCE POPS TO NORTH CENTRAL ONEIDA COUNTY AND EXTREME NORTHERN
ONONDAGA COUNTY THROUGH 15Z BEFORE KEEPING A DRY FORECAST. A
DEVELOPING AREA OF RAIN OVER SOUTH CENTRAL PA STILL LOOKS TO
SKIRT JUST SOUTHEAST OF OUR CWA BUT STILL FEEL SLIGHT CHANCE POPS
PRUDENT FOR NEPA AS A BUFFER. STILL LOOKING AT THE MAIN THREAT OF
RAIN TO COME AFTER 21Z TODAY WITH THE DISTURBANCE MOVING THROUGH
IL. THE PREVIOUS AFD IS BELOW...
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SLIDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS MAINTAIN SOME CONSISTENCY WITH INDICATIONS OF
BEST SHOT OF PRECIPITATION ACROSS THE ENTIRE REGION DURING THIS
PERIOD TO BE IN THE WEDNESDAY TIME FRAME. THIS IS THEN LIKELY TO
BE FOLLOWED BY DEEPENING COLD AIR AND A MAINTAINED PRESENCE OF
SHOWER CHANCES TO THE LEE OF LAKE ONTARIO THROUGH THURSDAY WITH
IMPROVED WX OVER THE SOUTHERN HALF. ANOTHER WEAK UPPER TROF AND
SFC FRONT MAY SPREAD A QUICK SHOT OF SHOWERS INTO THE AREA ON
FRIDAY. A FAIRLY LARGE CENTER OF CONTINENTAL POLAR...FALL-
LIKE...HIGH PRESSURE WORKS IN FOR AT LEAST THE FIRST HALF OF NEXT
WEEKEND.
FOLLOWED THE HPC DAY 3-7 GUIDANCE CLOSELY WITH ONLY MINOR LOCAL
ADJUSTMENTS TO TEMPERATURES.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
7 AM UPDATE...
MVFR CIGS POSSIBLE NEXT HOUR OR SO AT KRME DUE TO LAKE CLOUDS
OTHERWISE VFR THROUGH THIS AFTERNOON. HIGH CLOUDS AROUND 15KFT
LOWER TO 5KFT BY 20Z...WITH RAIN OVERSPREADING THE SOUTHERN
TERMINALS BY 22Z. UP NORTH SHOWERS POSSIBLE TOWARD 0Z...BUT NOT AS
LIKELY AS FARTHER SOUTH AND WILL ONLY COVER WITH A TEMPO GROUP.
ACROSS THE SOUTHERN TERMINALS...MVFR CIGS AND PERHAPS
VSBYS...APPEAR MOST LIKELY ABOUT 1 TO 2 HOURS AFTER THE ONSET OF
THE RAIN AND WILL PLAY AS A TEMPO GROUP THROUGH 04Z.
LATER TONIGHT THE TERMINALS WILL BEGIN TO CLEAR OUT. BASED ON THE
TIMING OF THE CLEARING...MVFR TO IFR CIGS AND VSBYS POSSIBLE
EVERYWHERE EXCEPT AT KSYR/KRME DUE TO VALLEY OR LOW STRATUS. MOST
CONFIDENT AT KELM.
NW WINDS OVERNIGHT 5 KTS OR LESS THROUGH THIS MORNING...THEN SW FLOW
LATER TODAY 5-10 KTS BECMG NWLY ACRS CNTRL NY LATE AFTERNOON.
NORTHWEST WINDS AROUND 5 KTS TONIGHT.
OUTLOOK...
MON TO TUE...VFR.
WED...VFR/MVFR. SOME SHOWERS.
THU...VFR. SOME LAKE EFFECT RAIN SHOWERS NORTH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
527 AM EDT SUN OCT 7 2012
.SYNOPSIS...
LAKE EFFECT RAIN SHOWERS WILL BE POSSIBLE EARLY THIS MORNING
ACROSS CENTRAL NEW YORK...OTHERWISE DRY WEATHER IS EXPECTED
THROUGH EARLY AFTERNOON. RAIN WILL OVERSPREAD THE AREA BY LATE
TODAY BEFORE ENDING EARLY TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT
AND THIS MAY ALLOW FOR SOME AREAS OF FROST TO FORM BY EARLY MONDAY
MORNING. MOSTLY DRY WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE
OUR NEXT SHOT AT WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVIING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SILDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS MAINTAIN SOME CONSISTENCY WITH INDICATIONS OF
BEST SHOT OF PRECIPITATION ACROSS THE ENTIRE REGION DURING THIS
PERIOD TO BE IN THE WEDNESDAY TIME FRAME. THIS IS THEN LIKELY TO
BE FOLLOWED BY DEEPENING COLD AIR AND A MAINTAINED PRESENCE OF
SHOWER CHANCES TO THE LEE OF LAKE ONTARIO THROUGH THURSDAY WITH
IMPROVED WX OVER THE SOUTHERN HALF. ANOTHER WEAK UPPER TROF AND
SFC FRONT MAY SPREAD A QUICK SHOT OF SHOWERS INTO THE AREA ON
FRIDAY. A FAIRLY LARGE CENTER OF CONTINENTAL POLAR...FALL-
LIKE...HIGH PRESSURE WORKS IN FOR AT LEAST THE FIRST HALF OF NEXT
WEEKEND.
FOLLOWED THE HPC DAY 3-7 GUIDANCE CLOSELY WITH ONLY MINOR LOCAL
ADJUSTMENTS TO TEMPERATURES.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
2 AM UPDATE...
GENERALLY VFR THROUGH EARLY THIS AFTERNOON. THE TWO EXCEPTIONS
WILL BE EARLY THIS MORNING WITH MVFR CIGS IN LAKE EFFECT CLOUDS
POSSIBLE UP NORTH..AND IFR FOG AT ELM. NOW TO THE DETAILS. AN
AREA OF LAKE EFFECT RAIN SHOWERS EAST OF LAKE ONTARIO NOW IS IN
THE PROCESS OF SHIFTING SOUTH AT THE MOMENT. ALTHOUGH NOTHING MORE
THAN A LIGHT SPRINKLE IS EXPECTED AT KSYR...MVFR CIGS WILL BE
POSSIBLE BETWEEN 07Z AND 11Z AS THIS BAND MOVES IN.
ELM FCST ALSO DIFFICULT...WITH LCL FOG CHECKLIST AND MOS GUIDANCE
INDICATING IFR ARND DAYBREAK. IT APPEARS THE LAKE CLOUDS WILL
REMAIN WEST OF THE TERMINAL...WHICH HAS ALREADY ALLOWED TEMPS TO
DROP INTO THE UPPER 30S OR CLOSE TO THE CROSSOVER TEMP FROM THIS
AFTERNOON. WITH THAT SAID UPR DECK MOVG IN FROM THE
SOUTHWEST NOW...SO THIS IS NOT A CONFIDENT FCST. WE DECIDED TO
HEDGE A BIT AND GO WITH BRIEF IFR DUE TO BR TWDS DAYBREAK. IF MORE
CLEARING OCCURS...THEN POTNL WILL EXIST FOR LIFR AT ELM.
LATER THIS AFTERNOON...-SHRA WILL SPREAD ACRS THE RGN. WE`VE
INDICATED MVFR WITH THIS PCPN AT ALL SITES XCPT SYR/RME WHERE
PROB30`S WERE USED BY EARLY TONIGHT. BEST CHC FOR RESTRICTIONS ON SUNDAY
AFTN WILL BE AFTER 22Z.
NW WINDS OPVERNIGHT 5 KTS OR LESS...THEN SW FLOW LATER TODAY
5-10 KTS BECMG NWLY ACRS CNTRL NY LATE AFTERNOON.
OUTLOOK...
SUN NIGHT...BECOMING VFR MOST AREAS. AREAS OF FOG AND RESTRICTIONS
POSSIBLE...ESPLY KELM.
MON TO TUE...VFR.
WED...VFR/MVFR. SOME SHOWERS.
THU...VFR. SOME LAKE EFFECT RAIN SHOWERS NORTH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
145 AM EDT SUN OCT 7 2012
.SYNOPSIS...
A WESTERLY FLOW OF CHILLY AIR WILL CONTINUE LAKE EFFECT RAIN SHOWERS
EAST OF LAKE ONTARIO TONIGHT WITH THE REST OF THE AREA PARTLY TO MOSTLY
CLOUDY. ANOTHER WEAK WAVE OF LOW PRESSURE WILL BRING SOME LIGHT RAIN
TO MUCH OF THE REGION SUNDAY ALONG WITH MORE COOL TEMPERATURES.
SKIES WILL BEGIN TO CLEAR SUNDAY NIGHT AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION...ALTHOUGH A FEW LAKE EFFECT SHOWERS MAY
LINGER EAST OF THE LAKES. DRY WEATHER WILL RETURN FOR MONDAY AND
TUESDAY AS HIGH PRESSURE REMAINS IN PLACE.
&&
.NEAR TERM /THROUGH TODAY/...
LAKE EFFECT RAIN ONGOING EAST OF LAKE ONTARIO LATE THIS EVENING.
OFF LAKE ONTARIO...
THIS BAND CONTINUES TO REMAIN FAIRLY WELL ORGANIZED. KTYX RADAR
SHOWING A NEARLY CONTINUOUS LINE OF PRECIP EAST-SOUTHEAST OF LAKE
ONTARIO. LIGHT TO OCCASIONALLY MODERATE RAINFALL IS ONGOING ACROSS
NORTHERN OSWEGO AND SOUTHERN LEWIS COUNTIES. JEFFERSON AND NORTHERN
LEWIS REMAIN DRY NORTH OF THE BAND. WITH THIS BAND LOCATED FURTHER
AWAY FROM THE SURFACE RIDGING ACROSS WNY IT WILL LIKELY CONTINUE TO
STAY ORGANIZED WELL INTO THE OVERNIGHT HOURS. 00Z NAM BUFKIT
INDICATED STILL CLOSE TO 10KFT FOR LAKE EL`S AND 400 J/KG OF LAKE
INDUCED CAPE. STILL EXPECT THE BAND FOR RAIN TO CONTINUE TO MOVE
SOUTHWARD OVER THE NEXT FEW HOURS. THE LATEST HRRR AND LOCAL WRF
MODELS ARE STILL IN AGREEMENT WITH THIS IDEA BUT ARE VERIFYING A
LITTLE TO FAR SOUTH COMPARED TO CURRENT RADAR. THE BAND WILL
EVENTUALLY LIE PARALLEL WITH THE SOUTHEASTERN SHORELINE OF LAKE
ONTARIO LATE TONIGHT WITH MOST OF THE RAINFALL OCCURRING ACROSS OSWEGO
COUNTY WITH PORTIONS OF NORTHERN CAYUGA AND NORTHEASTERN WAYNE
COUNTIES ALSO CATCHING SOME LIGHT RAIN.
LATE TONIGHT INTO SUNDAY MORNING AS FLOW BEGINS TO WEAKEN...LAND
BREEZE CONVERGENCE IS FORECAST TO INCREASE ALONG THE SOUTH SHORE OF
THE LAKE...WHICH MAY PRODUCE ANOTHER PERIOD OF MORE ORGANIZED LAKE
EFFECT AT THE SOUTHEAST CORNER OF THE LAKE. BY THIS TIME THE FLOW
WILL BE MUCH WEAKER...SO THE BAND SHOULD TEND TO HUG THE LAKESHORE
MORE AND NOT EXTEND VERY FAR INLAND. FINALLY BY MIDDAY SUNDAY THE
BOUNDARY LAYER FLOW BECOMES LIGHT ENOUGH TO ALLOW THE BAND TO TEA
KETTLE AND RETRACT BACK OUT OVER THE LAKE. INSTABILITY IS A LITTLE
GREATER OFF LAKE ONTARIO...AND THE BAND MAY LAST LONGER...SO EXPECT
RAINFALL POTENTIAL OF A QUARTER TO HALF INCH HERE...WITH THE
GREATEST AMOUNTS ACROSS CENTRAL AND SOUTHERN OSWEGO COUNTY.
OFF LAKE ERIE...
THE BAND EAST OF THE LAKE HAS BROKEN APART. 850 MB TEMPS ARE PLENTY
COLD ENOUGH (-2C OFF THE 00Z KBUF SOUNDING) BUT SURFACE RIDGING HAS
BUILT ACROSS MUCH OF WESTERN NY WITH A STRONG SURFACE HIGH CENTERED
OVER THE CENTRAL PLAINS. THIS SURFACE RIDGING HAS LOWERED EQUILIBRIUM
LEVELS DOWN TO AROUND 7000 FT WHICH IS MUCH TOO SHALLOW TO SUPPORT
AND RAIN IN ADDITION TO THE SURFACE RIDGING IN PLACE.
SUNDAY MORNING THERE MAY BE A BRIEF RESURGENCE OF LAKE EFFECT
ORGANIZATION AS BOUNDARY LAYER FLOW BECOMES A LITTLE MORE WESTERLY.
THIS WILL BE SHORT LIVED HOWEVER AS LOW LEVEL FLOW BECOMES VERY
LIGHT BY LATE MORNING...WITH ANY REMAINING LAKE EFFECT TENDING TO
TEA KETTLE OUT OVER THE LAKE AND NOT EXTEND INLAND.
OUTSIDE OF THE LAKE EFFECT...MOST LOCATIONS WILL SEE PARTLY TO
MOSTLY CLOUDY SKIES. LATEST IR IMAGERY SHOWS LAKE EFFECT CLOUDS OVER
MUCH OF WNY AND WITHIN THE BAND EAST OF LAKE ONTARIO. ONLY CLEAR
SPOTS AT 03Z WERE ACROSS CNY. MID LEVEL CLOUDS CAN ALSO BE SEEN ON
IR STREAMING NORTHEAST ACROSS WESTERN PA. THESE WILL INCREASE IN
COVERAGE ACROSS WESTERN NY AHEAD OF A DEVELOPING SURFACE WAVE.
SUNDAY...FOLLOWING ANY LINGERING LAKE EFFECT IN THE MORNING...OUR
ATTENTION TURNS BACK TO THE SYNOPTIC SCALE. LATEST SHORT TERM MODEL
GUIDANCE SWINGS A STRONG SHORTWAVE THROUGH THE MEAN LONGWAVE TROUGH
POSITION...CROSSING THE OHIO VALLEY AND PENNSYLVANIA DURING THE
AFTERNOON. THIS WILL INTERACT WITH A FRONTAL ZONE TO OUR SOUTH AND
PRODUCE A BAROCLINIC LEAF...WHICH WILL ACT TO INCREASE DIFFERENTIAL
THERMAL ADVECTION AND ISENTROPIC UPGLIDE ACROSS THE LOWER LAKES.
THIS WILL BRING THICKENING AND LOWERING CLOUD COVER DURING THE DAY
WITH A MORE WIDESPREAD LIGHT RAIN DEVELOPING BY MIDDAY OR EARLY
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN TIER AND FINGER LAKES
WHERE UP TO A QUARTER INCH MAY FALL. FARTHER NORTH...EXPECT THE
NORTHERN EDGE OF THE RAIN SHIELD TO CLIP THE NIAGARA FRONTIER EAST
TO ROCHESTER AND THE TUG HILL REGION WITH A LITTLE LIGHT RAIN IN THE
AFTERNOON.
THE THICKENING CLOUD COVER AND DEVELOPING RAIN WILL BRING ANOTHER
CHILLY DAY...WITH THE LOWER ELEVATIONS ONLY TOPPING OUT IN THE LOWER
50S AT BEST...WITH MID TO UPPER 40S ACROSS HIGHER TERRAIN.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
THE MAIN CONCERN FOR THE SUNDAY NIGHT THROUGH TUESDAY NIGHT PERIOD
IS THE POTENTIAL OF FROST...OR A WIDESPREAD FREEZE. THIS WOULD BE A
GOOD TIME TO ISSUE A FREEZE WATCH FOR SUNDAY NIGHT IF CONFIDENCE WAS
HIGH ENOUGH...BUT THERE IS TOO MUCH UNCERTAINTY ABOUT CLOUD COVER
AND RESULTING LOW TEMPERATURES AT THIS TIME.
A SHORTWAVE CURRENTLY MOVING INTO NE WILL BE IN THE PROCESS OF
MOVING THROUGH THE LOWER GREAT LAKES REGION BY SUNDAY AFTERNOON AND
EVENING. RAIN ACCOMPANYING THIS SYSTEM WILL MOST LIKELY AFFECT /AT
LEAST/ THE SOUTHERN TIER AND PA BEFORE MOVING EAST DURING SUNDAY
NIGHT AS THE SURFACE BASED COASTAL LOW NEAR DELMARVA MOVES FURTHER
OFFSHORE. THE END RESULT TOWARD MONDAY MORNING WILL BE CLOUDS
OVERHEAD MOVING OFF TO THE EAST...WITH A GOOD CHANCE FOR HIGH CLOUD
COVER AT LEAST OVER THE EASTERN LAKE ONTARIO REGION. IN
ADDITION...THERE SHOULD BE SOME ONGOING LAKE EFFECT RAIN SHOWERS
EAST OF THE LAKES OVERNIGHT...WITH CLOUDS SPREADING INTO THE HIGHER
TERRAIN EAST OF LAKE ONTARIO AND INTO THE SOUTHERN TIER...THE EXACT
LOCATION THAT WOULD NORMALLY BE THE COLDEST PLACES IN WESTERN NY. A
FREEZE IS POSSIBLE ON THE FRINGES OF ANY LAKE BANDS AND/OR HIGHER
CLOUD COVER...BUT AT THIS TIME IT IS TOO UNCERTAIN AS TO HOW
WIDESPREAD THE CLOUD COVER WILL BE. WILL THEREFORE ADD IN SOME
FROST INTO THE FORECAST FOR AREAS OUTSIDE OF ANTICIPATED THICKER
CLOUD COVER...BUT KEEP TEMPERATURES ABOVE THE FREEZING MARK FOR NOW.
ON MONDAY ANY LAKE EFFECT SHOULD QUICKLY END DURING THE MORNING WITH
HIGH PRESSURE MOVING INTO THE NORTHEAST. MONDAY NIGHT WILL FEATURE
MOSTLY CLEAR SKIES...SO ALTHOUGH TEMPERATURES ALOFT WILL WARM A BIT
OVER 24 HOURS...THERE WILL ONCE AGAIN BE A LOW CHANCE FOR SOME FROST
OR FREEZING CONDITIONS DUE TO RADIATIONAL COOLING. WILL HAVE A
SLIGHTLY LARGER AREA COVERED BY FROST FOR LATE MONDAY NIGHT IN THE
TRADITIONAL INLAND LOCATIONS...PRIMARILY THE SOUTHERN TIER AND WELL
EAST OF LAKE ONTARIO.
QUIET WEATHER IS EXPECTED FOR TUESDAY WITH A CONTINUED WARMING
TREND...WITH MAX TEMPERATURES APPROACHING NORMAL VALUES FOR THIS
TIME OF YEAR.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE REX BLOCK IN PLACE OVER THE EASTERN PACIFIC WILL REMAIN IN PLACE
OR V-E-R-Y SLOWLY MOVE INTO THE WESTERN US THE COURSE OF NEXT WEEK.
THEREFORE WE NEED TO LOOK ABOVE BC...NEAR THE TOP OF THE RIDGE FOR
THE NEXT FEATURE OF INTEREST. MEDIUM RANGE GUIDANCE HAS BEEN VERY
CONSISTENT BRING THE NEXT FEATURE DOWN THROUGH ALBERTA AND
SASKATCHEWAN EARLY NEXT WEEK...WITH A SURFACE LOW REMAINING IN CA
AND PIVOTING AROUND HUDSON BAY WHILE AN ASSOCIATED COLD FRONT SWEEPS
ACROSS THE GREAT LAKES REGION AND ACROSS NYS ON WEDNESDAY. THERE IS
SOME UNCERTAINTY AS TO TIMING WITH THE FRONT/PRECIPITATION...WITH
RAIN POSSIBLE EITHER WEDNESDAY OR WEDNESDAY NIGHT. WILL KEEP
FORECAST GENERALLY UNCHANGED FOR NOW WITH LIKELY RAIN IN THE WEST IN
THE AFTERNOON.
EXPECT A FAIRLY STRONG RIDGE AFTER THIS FOR THURSDAY WITH DRY
WEATHER. THEN ANOTHER FRONT DROPS ACROSS THE REGION DURING THE END
OF NEXT WEEK FOR ANOTHER CHANCE OF RAIN. TEMPERATURES DROP QUITE A
BIT BEHIND THIS NEXT FRONTAL PASSAGE...WITH 850MB TEMPERATURES DOWN
TO -7C EAST OF LAKE ONTARIO. HOWEVER...A FAIRLY STRONG RIDGE WILL
ALSO BE IN PLACE BY THE WEEKEND. RIGHT NOW LAKE EFFECT
POSSIBILITIES LOOK MINIMAL WITH A LOW LEVEL DRY AIRMASS ACROSS THE
LOWER GREAT LAKES REGION. ALTHOUGH THE CURRENT CONCERN FOR A
FROST/FREEZE IS FOR SUNDAY OR SUNDAY NIGHT...A BIGGER CONCERN MAY BE
NEXT WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
LAKE EFFECT RAIN SHOWERS WILL ORGANIZE EAST OF BOTH LAKE ERIE AND
LAKE ONTARIO OVERNIGHT. THE RAIN BANDS WILL PRIMARILY IMPACT
AREAS BETWEEN KROC AND KART OFF LAKE ONTARIO...FOCUSING ON KFZY
AND KSYR. KJHW COULD SEE SOME OF THIS ACTIVITY TOWARD 12Z SUNDAY
MORNING. OCCASIONAL MVFR CIGS AND VSBYS ALSO POSSIBLE IN THE LAKE
EFFECT. OUTSIDE OF THESE AREAS...VFR CIGS ARE EXPECTED. ON SUNDAY
LAKE EFFECT RAIN SHOWERS WILL LINGER THROUGH THE MORNING EAST OF
THE LAKES WITH AREAS OF MVFR AND LOCAL IFR. BY AFTERNOON A WEAK
WAVE OF LOW PRESSURE WILL PASS BY JUST TO THE SOUTH OF THE REGION.
THIS MAY PRODUCE A LITTLE MORE WIDESPREAD LIGHT RAIN...WITH
ASSOCIATED MVFR AND LOCAL IFR CONDITIONS ESPECIALLY ACROSS HIGHER
TERRAIN.
OUTLOOK...
MONDAY AND TUESDAY...VFR.
WEDNESDAY...AREAS OF MVFR WITH SHOWERS LIKELY.
THURSDAY...MAINLY VFR.
&&
.MARINE...
WINDS DIMINISHING STEADILY OVERNIGHT AS THE PRESSURE GRADIENT
RELAXES ACROSS THE AREA. A SMALL CRAFT ADVISORY REMAINS THROUGH
SUNDAY MORNING FOR THE EAST END OF LAKE ONTARIO AS OBSERVATIONS
THERE STILL SHOWING 20 TO 25 KT WINDS.
A WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE FOR THE REST OF SUNDAY
WITH MUCH LIGHTER WINDS...AND THE LIGHT WINDS WILL LAST INTO MONDAY
AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE LOWER LAKES.
WATERSPOUTS WILL BECOME MORE LIKELY THROUGH SUNDAY MORNING OFF LAKE
ONTARIO IN AND NEAR BANDS OF LAKE EFFECT SHOWERS AND CLOUDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
LOZ043>045.
&&
$$
SYNOPSIS...HITCHCOCK/SMITH
NEAR TERM...SMITH
SHORT TERM...ZAFF
LONG TERM...ZAFF
AVIATION...SMITH/TMA
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
740 AM EDT SUN OCT 7 2012
.SYNOPSIS...
A COLD FRONT OVER THE AREA WILL MOVE SOUTHEAST TO COASTAL SECTIONS
THIS MORNING. THE FRONT WILL BRIEFLY STALL OVER THE COASTAL AREAS
TODAY... BEFORE SHIFTING OFFSHORE THIS EVENING. THICK CLOUD COVER
AND A CHILLY AIR MASS WILL HOLD OVER THE REGION THROUGH MONDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 300 AM SUNDAY...
EARLY MORNING...
THE SURFACE COLD FRONT HAS PUSHED SOUTH THROUGH THE AREA SINCE LAST
EVENING...NOW STRETCHING FROM KGSP TO KMEB TO KPGV. A PATCH OF
SHOWERS MOVING NORTHEAST BETWEEN KGSO AND KRDU IS BEING AIDED BY A
WEAK DISTURBANCE LOFT IN WATER VAPOR AND INCREASING ISENTROPIC
ASCENT. THE 00Z KGSO RAOB SHOWERS ENOUGH INSTABILITY ABOVE THE
STRENGTHENING COLD DOME TO SUPPORT AT LEAST A FEW SPORADIC LIGHTNING
STRIKES THROUGH EARLY MORNING. THE HEAVIER SHOWERS A PRODUCING
BETWEEN ONE TO TWO TENTHS OF AN INCH OF RAINFALL. BASED ON RAP
ISENTROPIC FIELDS AND HRRR SIMULATED REFLECTIVITY...EXPECT THESE
SHOWERS TO CONTINUE MOVING OFF TO THE NORTHEAST AND OUT OF THE
NORTHERN PIEDMONT/COASTAL PLAIN BY 10Z.
TODAY...
A SHORTWAVE CURRENTLY APPROACHING THE MID MS VALLEY REGION WILL
SWING ACROSS THE OH VALLEY REGION THIS AFTERNOON..WITH PRECIP
SPREADING EAST AND EXPANDING ALONG THE 850MB FRONT THAT HAS STALLED
FROM THE LOWER TN VALLEY TO THE MID ATLANTIC STATES. WHILE THE FLOW
AHEAD OF THE SHORTWAVE WILL STRENGTHEN THIS AFTERNOON...WINDS IN THE
295-305K LAYER STAY RELATIVELY PARALLEL TO FRONTAL ZONE AND
CROSS-SECTIONS SHOW MUCH DEEPER MOISTURE ALONG AND WEST OF THE
MOUNTAINS. THUS...WHILE OVERCAST SKIES WILL DEVELOP THIS MORNING
DUE TO MOISTENING AT THE TOP OF THE STABLE LAYER...PRECIP AMOUNTS
SHOULD BE RELATIVELY LIGHT..WITH MODELS NOW ONLY SHOWING A TENTH OF
AN INCH OR LESS IN THE NORTHWEST PIEDMONT.
TO THE SOUTH AND EAST...THE COLD FRONT WILL STALL ACROSS SC AND
SOUTHEAST NC THIS MORNING. A WEAK WAVE OF LOW PRESSURE IS FORECAST
TO MOVE FROM CENTRAL NC TOWARD THE OBX THIS AFTERNOON...WHICH SHOULD
HELP TRIGGER SOME SHOWERS AND STORMS IN THE VICINITY OF THE FRONTAL
ZONE. FORECAST SOUNDINGS AT KFAY LOOK MUCH TOO STABLE FOR ANY NEAR
SURFACE BASED CONVECTION...BUT MUCAPE FORECASTS SHOW AROUND 400-600
J/KG JUST TO THE NORTH OF THE FRONT...SO AN ISOLATED AND ELEVATED
STORM COULD BE POSSIBLE OVER THE SOUTHEAST CWA. HOWEVER...THE COLD
FRONT IS FORECAST TO SURGE FURTHER SOUTH AND EAST AFTER 18Z (IN THE
WAKE OF THE SURFACE WAVE)...WITH THE POTENTIAL FOR AN THUNDER
BECOMING LESS LIKELY WITH TIME. THE POP FORECAST WILL SHOW A STRONG
GRADIENT FROM 80 IN THE NORTHWEST TO 25 IN THE SOUTHEAST.
THE RISE IN TEMPS TODAY WILL SOMEWHAT DEPEND ON HOW MUCH PRECIP
FALLS...WITH LESS RISE EXPECTED IN THE NORTHWEST PIEDMONT WITH
PERIODS OF RAIN EXPECTED THROUGH THIS AFTERNOON. THINNER MOISTURE
PROFILES AND A LITTLE MORE HEATING NEAR THE FRONT MAY ALLOW FOR SOME
LOWER 70S IN THE FAR SOUTHEASTERN AREAS. MID 50S TO LOWER 70S
ARE EXPECTED WITH A SHARP GRADIENT ACROSS THE PIEDMONT.
TONIGHT AND MONDAY...
AS HIGH PRESSURE EXPANDS ACROSS THE OHIO VALLEY TONIGHT...COOL AND
DRIER LOW LEVEL AIR WILL WORK SOUTH INTO THE AREA WITH DEW POINTS
FALLING INTO THE 40S CWA-WIDE. THIS WILL ALLOW FOR A LITTLE MORE
COOLING AND LOWS REACHING THE 42-49 RANGE AND NO RAIN OVERNIGHT.
ANOTHER SHORTWAVE OVER CO/WY THIS MORNING WILL SWING FURTHER SOUTH
TOWARD THE TN VALLEY MONDAY...WITH A LITTLE BETTER RAIN CHANCES OVER
ALL OF CENTRAL NC AS THE 850MB DRIFTS EASTWARD AND THE RIGHT
ENTRANCE REGION OF THE PERSISTENT UPPER JET TO OUR NORTH SHIFTS
OVERHEAD. ISENTROPIC ASCENT...WHILE STRONGER...IS STILL NOT VERY
IMPRESSIVE...SO RAINFALL TOTALS MAY AGAIN BE LIGHT. HOWEVER...
TEMPS WILL LIKELY NOT RISE MUCH AT ALL ACROSS THE CWA AS A BETTER
COLD AIR DAMMING AIRMASS DEVELOPS...WITH MOST GUIDANCE INDICATING
LOW TO MID 50S...POSSIBLY 60 IN THE FAR SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 220 AM SUNDAY...
FOR MONDAY NIGHT: PATTERN REMAINS DOMINATED BY FAST MID LEVEL
CYCLONIC FLOW... ON THE COLD SIDE OF A SURFACE BOUNDARY... RESULTING
IN CHILLY AND HIGHLY UNSETTLED WEATHER. THE PARENT HIGH SUPPORTING
THE DAMMING REGIME WILL BE CENTERED OVER THE COAST OF MAINE AND
CANADIAN MARITIMES WHILE EXTENDING TO THE SW... THROUGH THE NC
FOOTHILLS AND WRN PIEDMONT. MOIST UPGLIDE AT 290K-295K IS NOT
PARTICULARLY INTENSE OVER CENTRAL NC BUT THE PRESENCE OF A DEEP
NEARLY SATURATED LAYER AT 950 MB TO 750 MB SHOULD MAKE THIS LIFT
VERY PRODUCTIVE IN TERMS OF CONDENSATION AND PRECIP... AND THE
FAST-MOVING PASSAGE OF A MID LEVEL WAVE THROUGH THE AREA SHOULD
FURTHER AUGMENT LIFT. UPPER DIVERGENCE OVER CENTRAL NC... IN THE
RIGHT ENTRANCE REGION OF THE 120+ KT UPPER JET CORE OVER AND JUST
OFF THE NORTHEAST COAST ON MONDAY... QUICKLY DIMINISHES AS THE JET
MOVES AWAY TO THE NE... AND FORECAST SOUNDINGS CONFIRM DRYING ALOFT
OVERNIGHT... HOWEVER THE COLUMN WILL REMAIN NEARLY SATURATED BELOW
750 MB WITH LOWERING CEILINGS OVERNIGHT WITHIN THE PERSISTENT
DAMMING-INDUCED STABLE LAYER. THE MOIST UPGLIDE LARGELY ENDS AFTER
MIDNIGHT... AS THE WINDS ALOFT DECELERATE AND THE MID LEVEL WAVE
EXITS ALONG WITH THE UPPER JET-RELATED FORCING FOR ASCENT. EXPECT A
GRADUAL LOWERING OF LIGHT RAIN AND DRIZZLE COVERAGE FROM SOUTH TO
NORTH THROUGH THE NIGHT... ENDING LAST IN THE FAR NORTHWEST CWA
(ROXBORO THROUGH THE TRIAD) WHERE SLOPED ASCENT WILL LINGER ALONG A
WEAK 925 MB FRONTAL ZONE. LOW CLOUDS... AREAS OF FOG... AND POCKETS
OF DRIZZLE ARE LIKELY TO PERSIST AREAWIDE THROUGH DAYBREAK. TEMPS
SHOULD DROP NO MORE THAN 10 DEGREES OR SO FROM THE PRECEDING CHILLY
DAYTIME TEMPS... YIELDING LOWS OF 42-49.
FOR TUESDAY/TUESDAY NIGHT: THE MID LEVEL CANADIAN VORTEX WOBBLES
OVER HUDSON BAY WHILE ITS TRAILING BROAD TROUGHING SHIFTS SLOWLY
FROM THE UPPER MIDWEST TOWARD MI WHILE AMPLIFYING. THE STRONG
(ROUGHLY 1030 MB) PARENT SURFACE HIGH CENTERED OVER NOVA SCOTIA
EARLY TUESDAY CONTINUES MOVING NORTHEAST OVER THE MARITIMES...
CAUSING THE TRAILING RIDGE TO LOSE ITS GRIP ON CENTRAL NC AND LEAVE
BEHIND A DISCONNECTED WEAK RESIDUAL COOL STABLE POOL. THIS
SEPARATION FROM THE SUPPLY OF COOL DRY AIR TO MAINTAIN THE DAMMING
AIR MASS WILL ALLOW IT TO BECOME VULNERABLE TO HORIZONTAL DISPERSION
AND CONVECTIVE MIXING AS THE DRIER AIR ALOFT ALLOWS STRONG HEATING
FROM THE TOP... ALTHOUGH TYPICALLY THIS EROSION PROCESS OFTEN TAKES
QUITE A WHILE PARTICULARLY WITH A STABLE LAYER THIS DEEP. WILL BE
SLOW TO GET RID OF THE WEDGE-SUPPORTED CLOUDS ON TUESDAY... TRENDING
GRADUALLY TO PARTLY CLOUDY LATE IN THE DAY. THE WEAK HIGH WILL DRIFT
BACK TOWARD THE SW TO OVER THE INTERIOR SOUTHEAST STATES TUESDAY
NIGHT... AND WITH THE RESULTING MODIFICATION OF THE AIR MASS...
THICKNESSES WILL START TO REBOUND BUT SHOULD STILL HOLD WELL BELOW
NORMAL FOR ANOTHER DAY GIVEN THE DELAYED HEATING. EXPECT MODEST
WARMING WITH HIGHS OF 60-68. EXPECT FAIR SKIES TUESDAY NIGHT WITH
CONTINUED DRYING ALOFT... ALTHOUGH RECOVERING SURFACE DEW POINTS
COMBINED WITH LIGHT WINDS IS LIKELY TO LEAD TO DEVELOPMENT OF GROUND
FOG OVERNIGHT. LOWS 47-52. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 250 AM SUNDAY...
EXPECT GENERALLY DRY WEATHER BUT WITH ROLLER COASTER TEMPS AS A
SUCCESSION OF FRONTS DROPS THROUGH THE REGION.
FOR WEDNESDAY/WEDNESDAY NIGHT: THE MID LEVEL TROUGH AXIS SWINGS
SWIFTLY ENE THROUGH THE GREAT LAKES AND NORTHEAST STATES... DRAGGING
A SURFACE COLD FRONT THROUGH CENTRAL NC WEDNESDAY AFTERNOON. GIVEN
THAT THE SURFACE HIGH CENTER WILL BE LOCATED TO OUR SOUTH AND SW...
THERE WILL BE LITTLE TO NO MOISTURE FLUX AHEAD OF THE FRONT... THUS
IT SHOULD COME THROUGH DRY. THICKNESSES ARE PROJECTED TO BE AT OR
JUST ABOVE NORMAL WEDNESDAY... TRANSLATING TO HIGHS IN THE MID TO
UPPER 70S. YUKON-SOURCE HIGH PRESSURE BUILDING IN BEHIND THE FRONT
SHOULD SEND THICKNESSES PLUNGING BACK DOWN BELOW NORMAL... WITH LOWS
IN THE MID 40S TO NEAR 50.
FOR THURSDAY THROUGH SATURDAY: THE SURFACE HIGH IS EXPECTED TO BUILD
OVER NC ON THURSDAY... WITH BROAD/FAST/CYCLONIC MID LEVEL FLOW FROM
SW CANADA ACROSS THE NORTHEAST STATES. FAIR AND DRY THURSDAY WITH
INITIALLY COOL BUT MODERATING TEMPS. A MINOR WAVE DROPS INTO THE
LONGWAVE TROUGH OVER THE GREAT LAKES... AND THIS ACCOMPANYING
SURFACE COLD FRONT WILL APPROACH NC FROM THE NNW ON FRIDAY. ONCE
AGAIN... VERY LITTLE MOISTURE IS AVAILABLE AHEAD OF AND ALONG THE
FRONT AND LIFT WILL BE WEAK... SO EXPECT NO MORE THAN ISOLATED
SHOWERS AT BEST. TEMPS SHOULD BOUNCE BACK UP TO NEAR NORMAL AHEAD OF
THE FRONT FRIDAY. YET ANOTHER COOL HIGH BUILDS IN BEHIND THE FRONT
FROM THE NORTH... ITS CENTER MOVING FROM OVER SW MI TO OFF THE
NJ/DELMARVA COAST FROM FRIDAY EVENING THROUGH SATURDAY AS IT RIDGES
SOUTHWARD THROUGH CENTRAL NC. EXPECT A SLIGHT COOLDOWN OF AROUND A
CATEGORY FOR SATURDAY... WITH CONTINUED DRY WEATHER. -GIH
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 740 AM SUNDAY...
A SMALL CLUSTER OF SHOWERS AND STORMS HAS DEVELOPED OVER
SOUTHWESTERN NC AND IS MOVING RELATIVELY QUICKLY TO THE EAST ALONG A
STALLED OUT COLD FRONT NEAR THE NC/SC BORDER. BRIEF HEAVY RAIN AND
A GUST TO AROUND 30KT WITH THE HEAVIEST SHOWERS. NORTH OF THE
FRONT...CEILINGS ARE GENERALLY MVFR WITH SOME IFR CONDITIONS
REPORTED AT KGSO/KINT. THESE LOWER CEILINGS WILL PERSIST AT
KINT/KGSO/KRDU/KRWI THROUGH THIS AFTERNOON...WITH SOME SCATTERING
AND IMPROVEMENT POSSIBLE AT KFAY IS THE FRONT LIFTS BACK TO THE
NORTH OF THE TERMINAL...AS RECENT MODEL RUNS SUGGEST.
DRIER AIR IS EXPECTED TO FILTER INTO THE ARE THIS EVENING AND
OVERNIGHT...LEADING TO A TEMPORARY IMPROVEMENT OF CEILINGS TO MVFR
OR VFR. HOWEVER...ANOTHER DISTURBANCE ALOFT IS EXPECTED TO
IMPACT THE AREA MONDAY...WITH WIDESPREAD MVFR/IFR CEILINGS TO
REDEVELOP.
OUTLOOK...
LOW CEILINGS WILL LIKELY CONTINUE THROUGH AT LEAST TUESDAY...WITH
IMPROVEMENT IN AVIATION CONDITIONS BY THE MIDDLE TO END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BLS
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT SUN OCT 7 2012
.SYNOPSIS...
A COLD FRONT OVER THE AREA WILL MOVE SOUTHEAST TO COASTAL SECTIONS
THIS MORNING. THE FRONT WILL BRIEFLY STALL OVER THE COASTAL AREAS
TODAY... BEFORE SHIFTING OFFSHORE THIS EVENING. THICK CLOUD COVER
AND A CHILLY AIR MASS WILL HOLD OVER THE REGION THROUGH MONDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 300 AM SUNDAY...
EARLY MORNING...
THE SURFACE COLD FRONT HAS PUSH SOUTH THROUGH THE AREA SINCE LAST
EVENING...NOW STRETCHING FROM KGSP TO KMEB TO KPGV. A PATCH OF
SHOWERS MOVING NORTHEAST BETWEEN KGSO AND KRDU IS BEING AIDED BY A
WEAK DISTURBANCE LOFT IN WATER VAPOR AND INCREASING ISENTROPIC
ASCENT. THE 00Z KGSO RAOB SHOWERS ENOUGH INSTABILITY ABOVE THE
STRENGTHENING COLD DOME TO SUPPORT AT LEAST A FEW SPORADIC LIGHTNING
STRIKES THROUGH EARLY MORNING. THE HEAVIER SHOWERS A PRODUCING
BETWEEN ONE TO TWO TENTHS OF AN INCH OF RAINFALL. BASED ON RAP
ISENTROPIC FIELDS AND HRRR SIMULATED REFLECTIVITY...EXPECT THESE
SHOWERS TO CONTINUE MOVING OFF TO THE NORTHEAST AND OUT OF THE
NORTHERN PIEDMONT/COASTAL PLAIN BY 10Z.
TODAY...
A SHORTWAVE CURRENTLY APPROACHING THE MID MS VALLEY REGION WILL
SWING ACROSS THE OH VALLEY REGION THIS AFTERNOON..WITH PRECIP
SPREADING EAST AND EXPANDING ALONG THE 850MB FRONT THAT HAS STALLED
FROM THE LOWER TN VALLEY TO THE MID ATLANTIC STATES. WHILE THE FLOW
AHEAD OF THE SHORTWAVE WILL STRENGTHEN THIS AFTERNOON...WINDS IN THE
295-305K LAYER STAY RELATIVELY PARALLEL TO FRONTAL ZONE AND
CROSS-SECTIONS SHOW MUCH DEEPER MOISTURE ALONG AND WEST OF THE
MOUNTAINS. THUS...WHILE OVERCAST SKIES WILL DEVELOP THIS MORNING
DUE TO MOISTENING AT THE TOP OF THE STABLE LAYER...PRECIP AMOUNTS
SHOULD BE RELATIVELY LIGHT..WITH MODELS NOW ONLY SHOWING A TENTH OF
AN INCH OR LESS IN THE NORTHWEST PIEDMONT.
TO THE SOUTH AND EAST...THE COLD FRONT WILL STALL ACROSS SC AND
SOUTHEAST NC THIS MORNING. A WEAK WAVE OF LOW PRESSURE IS FORECAST
TO MOVE FROM CENTRAL NC TOWARD THE OBX THIS AFTERNOON...WHICH SHOULD
HELP TRIGGER SOME SHOWERS AND STORMS IN THE VICINITY OF THE FRONTAL
ZONE. FORECAST SOUNDINGS AT KFAY LOOK MUCH TOO STABLE FOR ANY NEAR
SURFACE BASED CONVECTION...BUT MUCAPE FORECASTS SHOW AROUND 400-600
J/KG JUST TO THE NORTH OF THE FRONT...SO AN ISOLATED AND ELEVATED
STORM COULD BE POSSIBLE OVER THE SOUTHEAST CWA. HOWEVER...THE COLD
FRONT IS FORECAST TO SURGE FURTHER SOUTH AND EAST AFTER 18Z (IN THE
WAKE OF THE SURFACE WAVE)...WITH THE POTENTIAL FOR AN THUNDER
BECOMING LESS LIKELY WITH TIME. THE POP FORECAST WILL SHOW A STRONG
GRADIENT FROM 80 IN THE NORTHWEST TO 25 IN THE SOUTHEAST.
THE RISE IN TEMPS TODAY WILL SOMEWHAT DEPEND ON HOW MUCH PRECIP
FALLS...WITH LESS RISE EXPECTED IN THE NORTHWEST PIEDMONT WITH
PERIODS OF RAIN EXPECTED THROUGH THIS AFTERNOON. THINNER MOISTURE
PROFILES AND A LITTLE MORE HEATING NEAR THE FRONT MAY ALLOW FOR SOME
LOWER 70S IN THE FAR SOUTHEASTERN AREAS. MID 50S TO LOWER 70S
ARE EXPECTED WITH A SHARP GRADIENT ACROSS THE PIEDMONT.
TONIGHT AND MONDAY...
AS HIGH PRESSURE EXPANDS ACROSS THE OHIO VALLEY TONIGHT...COOL AND
DRIER LOW LEVEL AIR WILL WORK SOUTH INTO THE AREA WITH DEW POINTS
FALLING INTO THE 40S CWA-WIDE. THIS WILL ALLOW FOR A LITTLE MORE
COOLING AND LOWS REACHING THE 42-49 RANGE AND NO RAIN OVERNIGHT.
ANOTHER SHORTWAVE OVER CO/WY THIS MORNING WILL SWING FURTHER SOUTH
TOWARD THE TN VALLEY MONDAY...WITH A LITTLE BETTER RAIN CHANCES OVER
ALL OF CENTRAL NC AS THE 850MB DRIFTS EASTWARD AND THE RIGHT
ENTRANCE REGION OF THE PERSISTENT UPPER JET TO OUR NORTH SHIFTS
OVERHEAD. ISENTROPIC ASCENT...WHILE STRONGER...IS STILL NOT VERY
IMPRESSIVE...SO RAINFALL TOTALS MAY AGAIN BE LIGHT. HOWEVER...
TEMPS WILL LIKELY NOT RISE MUCH AT ALL ACROSS THE CWA AS A BETTER
COLD AIR DAMMING AIRMASS DEVELOPS...WITH MOST GUIDANCE INDICATING
LOW TO MID 50S...POSSIBLY 60 IN THE FAR SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 220 AM SUNDAY...
FOR MONDAY NIGHT: PATTERN REMAINS DOMINATED BY FAST MID LEVEL
CYCLONIC FLOW... ON THE COLD SIDE OF A SURFACE BOUNDARY... RESULTING
IN CHILLY AND HIGHLY UNSETTLED WEATHER. THE PARENT HIGH SUPPORTING
THE DAMMING REGIME WILL BE CENTERED OVER THE COAST OF MAINE AND
CANADIAN MARITIMES WHILE EXTENDING TO THE SW... THROUGH THE NC
FOOTHILLS AND WRN PIEDMONT. MOIST UPGLIDE AT 290K-295K IS NOT
PARTICULARLY INTENSE OVER CENTRAL NC BUT THE PRESENCE OF A DEEP
NEARLY SATURATED LAYER AT 950 MB TO 750 MB SHOULD MAKE THIS LIFT
VERY PRODUCTIVE IN TERMS OF CONDENSATION AND PRECIP... AND THE
FAST-MOVING PASSAGE OF A MID LEVEL WAVE THROUGH THE AREA SHOULD
FURTHER AUGMENT LIFT. UPPER DIVERGENCE OVER CENTRAL NC... IN THE
RIGHT ENTRANCE REGION OF THE 120+ KT UPPER JET CORE OVER AND JUST
OFF THE NORTHEAST COAST ON MONDAY... QUICKLY DIMINISHES AS THE JET
MOVES AWAY TO THE NE... AND FORECAST SOUNDINGS CONFIRM DRYING ALOFT
OVERNIGHT... HOWEVER THE COLUMN WILL REMAIN NEARLY SATURATED BELOW
750 MB WITH LOWERING CEILINGS OVERNIGHT WITHIN THE PERSISTENT
DAMMING-INDUCED STABLE LAYER. THE MOIST UPGLIDE LARGELY ENDS AFTER
MIDNIGHT... AS THE WINDS ALOFT DECELERATE AND THE MID LEVEL WAVE
EXITS ALONG WITH THE UPPER JET-RELATED FORCING FOR ASCENT. EXPECT A
GRADUAL LOWERING OF LIGHT RAIN AND DRIZZLE COVERAGE FROM SOUTH TO
NORTH THROUGH THE NIGHT... ENDING LAST IN THE FAR NORTHWEST CWA
(ROXBORO THROUGH THE TRIAD) WHERE SLOPED ASCENT WILL LINGER ALONG A
WEAK 925 MB FRONTAL ZONE. LOW CLOUDS... AREAS OF FOG... AND POCKETS
OF DRIZZLE ARE LIKELY TO PERSIST AREAWIDE THROUGH DAYBREAK. TEMPS
SHOULD DROP NO MORE THAN 10 DEGREES OR SO FROM THE PRECEDING CHILLY
DAYTIME TEMPS... YIELDING LOWS OF 42-49.
FOR TUESDAY/TUESDAY NIGHT: THE MID LEVEL CANADIAN VORTEX WOBBLES
OVER HUDSON BAY WHILE ITS TRAILING BROAD TROUGHING SHIFTS SLOWLY
FROM THE UPPER MIDWEST TOWARD MI WHILE AMPLIFYING. THE STRONG
(ROUGHLY 1030 MB) PARENT SURFACE HIGH CENTERED OVER NOVA SCOTIA
EARLY TUESDAY CONTINUES MOVING NORTHEAST OVER THE MARITIMES...
CAUSING THE TRAILING RIDGE TO LOSE ITS GRIP ON CENTRAL NC AND LEAVE
BEHIND A DISCONNECTED WEAK RESIDUAL COOL STABLE POOL. THIS
SEPARATION FROM THE SUPPLY OF COOL DRY AIR TO MAINTAIN THE DAMMING
AIR MASS WILL ALLOW IT TO BECOME VULNERABLE TO HORIZONTAL DISPERSION
AND CONVECTIVE MIXING AS THE DRIER AIR ALOFT ALLOWS STRONG HEATING
FROM THE TOP... ALTHOUGH TYPICALLY THIS EROSION PROCESS OFTEN TAKES
QUITE A WHILE PARTICULARLY WITH A STABLE LAYER THIS DEEP. WILL BE
SLOW TO GET RID OF THE WEDGE-SUPPORTED CLOUDS ON TUESDAY... TRENDING
GRADUALLY TO PARTLY CLOUDY LATE IN THE DAY. THE WEAK HIGH WILL DRIFT
BACK TOWARD THE SW TO OVER THE INTERIOR SOUTHEAST STATES TUESDAY
NIGHT... AND WITH THE RESULTING MODIFICATION OF THE AIR MASS...
THICKNESSES WILL START TO REBOUND BUT SHOULD STILL HOLD WELL BELOW
NORMAL FOR ANOTHER DAY GIVEN THE DELAYED HEATING. EXPECT MODEST
WARMING WITH HIGHS OF 60-68. EXPECT FAIR SKIES TUESDAY NIGHT WITH
CONTINUED DRYING ALOFT... ALTHOUGH RECOVERING SURFACE DEW POINTS
COMBINED WITH LIGHT WINDS IS LIKELY TO LEAD TO DEVELOPMENT OF GROUND
FOG OVERNIGHT. LOWS 47-52. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 250 AM SUNDAY...
EXPECT GENERALLY DRY WEATHER BUT WITH ROLLER COASTER TEMPS AS A
SUCCESSION OF FRONTS DROPS THROUGH THE REGION.
FOR WEDNESDAY/WEDNESDAY NIGHT: THE MID LEVEL TROUGH AXIS SWINGS
SWIFTLY ENE THROUGH THE GREAT LAKES AND NORTHEAST STATES... DRAGGING
A SURFACE COLD FRONT THROUGH CENTRAL NC WEDNESDAY AFTERNOON. GIVEN
THAT THE SURFACE HIGH CENTER WILL BE LOCATED TO OUR SOUTH AND SW...
THERE WILL BE LITTLE TO NO MOISTURE FLUX AHEAD OF THE FRONT... THUS
IT SHOULD COME THROUGH DRY. THICKNESSES ARE PROJECTED TO BE AT OR
JUST ABOVE NORMAL WEDNESDAY... TRANSLATING TO HIGHS IN THE MID TO
UPPER 70S. YUKON-SOURCE HIGH PRESSURE BUILDING IN BEHIND THE FRONT
SHOULD SEND THICKNESSES PLUNGING BACK DOWN BELOW NORMAL... WITH LOWS
IN THE MID 40S TO NEAR 50.
FOR THURSDAY THROUGH SATURDAY: THE SURFACE HIGH IS EXPECTED TO BUILD
OVER NC ON THURSDAY... WITH BROAD/FAST/CYCLONIC MID LEVEL FLOW FROM
SW CANADA ACROSS THE NORTHEAST STATES. FAIR AND DRY THURSDAY WITH
INITIALLY COOL BUT MODERATING TEMPS. A MINOR WAVE DROPS INTO THE
LONGWAVE TROUGH OVER THE GREAT LAKES... AND THIS ACCOMPANYING
SURFACE COLD FRONT WILL APPROACH NC FROM THE NNW ON FRIDAY. ONCE
AGAIN... VERY LITTLE MOISTURE IS AVAILABLE AHEAD OF AND ALONG THE
FRONT AND LIFT WILL BE WEAK... SO EXPECT NO MORE THAN ISOLATED
SHOWERS AT BEST. TEMPS SHOULD BOUNCE BACK UP TO NEAR NORMAL AHEAD OF
THE FRONT FRIDAY. YET ANOTHER COOL HIGH BUILDS IN BEHIND THE FRONT
FROM THE NORTH... ITS CENTER MOVING FROM OVER SW MI TO OFF THE
NJ/DELMARVA COAST FROM FRIDAY EVENING THROUGH SATURDAY AS IT RIDGES
SOUTHWARD THROUGH CENTRAL NC. EXPECT A SLIGHT COOLDOWN OF AROUND A
CATEGORY FOR SATURDAY... WITH CONTINUED DRY WEATHER. -GIH
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 135 AM SUNDAY...
SHOWERS CURRENTLY MOVING NORTHEAST THROUGH THE PIEDMONT ARE CAUSING
BRIEF MVFR CEILINGS AND WILL MOVE OVER KRDU BY 08Z. THE COLD FRONT
THAT HAS BEEN MOVING SOUTH THROUGH THE AREA HAS NOW SETTLED SOUTH OF
KFAY...ALTHOUGH THERE IS ENOUGH ELEVATED INSTABILITY NORTH OF THE
FRONT FOR A FEW LIGHTNING STRIKES WITH THE HEAVIEST SHOWERS.
ELSEWHERE...VFR CONDITIONS ARE CURRENTLY OBSERVED BUT WILL
DETERIORATE THIS MORNING AS MOISTURE CONTINUES TO INCREASE ON THE
NORTH/COOL SIDE OF OF THE FRONT. FORECAST SOUNDINGS GENERALLY AGREE
ON MVFR CEILINGS LOWERING TO AROUND 1500 FT BY MIDDAY WITH THE
CHANCE FOR RAIN HIGHEST AT KGSO/KINT. SOME BREAKS OR LIFTING OF
CEILINGS AND SCATTERED SHOWERS MAY DEVELOP IN THE VICINITY OF THE
FRONT...BUT THE FRONT ITSELF IS EXPECTED TO REMAIN SOUTH AND EAST OF
KFAY/KRWI...SUCH THAT THE CONFIDENCE IN SHOWERS OR AN ISOLATED STORM
IS TOO LOW FOR MENTION IN THE KFAY TAF.
SOME DRYING FROM THE NORTH IS EXPECTED THIS EVENING...MOSTLY AFTER
00Z...AND THUS CEILINGS SHOULD EVENTUALLY SCATTER AND LIFT TO VFR AT
MOST SITES PRIOR TO MIDNIGHT. HOWEVER...ANOTHER DISTURBANCE ALOFT
IS EXPECTED TO IMPACT THE AREA MONDAY...WITH WIDESPREAD MVFR/IFR
CEILINGS TO REDEVELOP.
OUTLOOK...
LOW CEILINGS WILL LIKELY CONTINUE THROUGH AT LEAST TUESDAY...WITH
IMPROVEMENT IN AVIATION CONDITIONS BY THE MIDDLE TO END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BLS
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1257 PM CDT SUN OCT 7 2012
.DISCUSSION...NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING
FORECAST. THE 14Z HRRR CONTINUES TO BE THE MOST AGGRESSIVE MODEL
SHOWING PRECIP ACTIVITY DEVELOPING INITIALLY ALONG THE WARM FRONT
AND MOVING INTO WESTERN NORTH DAKOTA LATER THIS AFTERNOON. THE 12Z
GFS IS BECOMING MORE AGGRESSIVE WITH ITS PROG OF PRECIP WEST.
HOWEVER...IT IS SLOWER WITH ITS PROGRESSION. ON THE OTHER
HAND...THE 12Z NAM IS COMPLETELY DRY WITH ITS PROG AREAWIDE THROUGH
06Z MONDAY. WITH THAT BEING SAID...SIDED WITH A GFS (WHICH IS A
PROXY FOR A MODEL BLEND) TO FORECAST 20 POPS NORTHWEST FROM 21Z-
24Z SUNDAY...THEN EXPANDED SLIGHT CHANCE POPS SOUTH AND EAST FROM
00Z-06Z MONDAY. NO MAJOR IMPACTS ARE EXPECTED. THE UPDATED
GRIDDED AND TEXT PRODUCTS WILL BE OUT SHORTLY.
&&
.AVIATION...LOW PRESSURE OUT OF CANADA WILL BEGIN TO MOVE SOUTH
INTO THE REGION LATE TONIGHT EARLY TOMORROW MORNING. EXPECT SOME
SCATTERED SHOWERS FROM THIS SYSTEM WITH THE BEST CHANCES NORTH AT
SITES ISN AND MOT AFTER 00Z. LOW CEILINGS JUST ABOVE THE MVFR
RANGE WILL MOVE IN FROM NORTH TO SOUTH AROUND 10Z. CEILINGS COULD
GO LOWER INTO THE MVFR CATEGORY. HOWEVER...THIS WILL BE REVISITED IN
LATER TAFS. VFR CONDITIONS ARE EXPECTED THROUGH THE 18Z TAF CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TM...UPDATE
JWS/MM...AVIATION
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1008 AM CDT SUN OCT 7 2012
.DISCUSSION...THE 11Z HRRR AND 06Z GFS HAVE SPED UP THE TIMING OF
A SHORTWAVE DIVING ACROSS SASKATCHEWAN TODAY AND INTO THE
NORTHWESTERN CWA LATER THIS AFTERNOON. HOWEVER...THE SHORT RANGE
MODELS PROG THIS ACTIVITY TO CROSS THE MT/ND BORDER AFTER 21Z
TODAY. AS A RESULT...UPDATED THE FORECAST TO INDICATE DRY
CONDITIONS AREAWIDE UNTIL 21Z...THEN INCREASED PRECIP CHANCES FOR
THE EXTREME NORTHWEST AFTER 21Z. THE THERMAL PROFILES INDICATE
THAT ANY PRECIP THAT DOES FALL SHOULD BE IN THE FORM OF ALL
LIQUID. ALSO ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS TO ACCOUNT
FOR THE CURRENT OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS
WILL BE OUT SHORTLY.
&&
.AVIATION...INCREASING VFR CLOUDINESS OVER WESTERN AND CENTRAL
NORTH DAKOTA CAN BE EXPECTED AS WEAK WARM FRONT MOVES THROUGH.
SOME WIND GUSTS WILL BE POSSIBLE THIS AFTERNOON IN HIGHER ELEVATIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TM...UPDATE
HW...AVIATION
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
649 AM EDT SUN OCT 7 2012
.SYNOPSIS...
MID/UPPER LEVEL WAVE STREAKS THROUGH TODAY. ANOTHER WAVE SKIRTS
SOUTHERN AND EASTERN PORTIONS OF THE REGION MONDAY. A THIRD WAVE IS
POSSIBLE MONDAY NIGHT INTO TUESDAY. COLD FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
630AM UPDATE...
FINESSED POPS THIS MORNING TO REFLECT QUICKER EXODUS OF -RA ACROSS
MTNS...PER LATEST RUC AND UPSTREAM TRENDS ACROSS TN VALLEY.
OTHERWISE NO OTHER CHANGES ATTM.
PREVIOUS DISCUSSION BELOW...
QUITE A CHALLENGING FCST IN THE NEAR TERM. FIRST ORDER OF
BUSINESS IS UPR LVL SYS TDY...COUPLED WITH SFC WAVE RIDING ALONG
STALLED OUT BOUNDARY TO S OF CWA. WEAK ECHOES NOTED CURRENTLY ON
RADAR ACROSS SW VA AND WV MTNS...WITH SOMEWHAT HEAVIER PCPN ACROSS
CUMBERLAND PLATEAU. MDL CONSENSUS IS FOR GENERALLY LIGHT QPF THIS
MORNING ACROSS SW VA...EXTENDING UP THE WV MTNS WITH SFC WAVE.
BEST ISENTROPIC LIFT LOOKS TO BE ALONG AND E OF THE EASTERN SLOPES
AND THIS IS WHERE HIGHEST POPS WERE PLACED. STILL SOME QUESTION
ABOUT HOW FAR WEST PCPN IS ABLE TO MAKE IT...GIVEN LACK OF GOOD
ISENTROPIC LIFT AND STOUT LLVL DRY LYR. WILL ALLOW SCHC POPS TO
EXTEND JUST W OF I79/US119 CORRIDOR...KEEPING WESTERN LOWLANDS AND
SE OH DRY THIS MORNING. WILL WATCH FOR APPROACH OF S/W TROF THIS
AFTN WHICH WILL HOOK UP WITH LINGERING MOISTURE OVER AREA FOR SCT
SHRA ACROSS SE OH AND N HALF OF WV. HAVE THIS COVERED WITH SOME
CHC POPS. SHOULD SEE SOME CLRING ACROSS NE KY...SW VA AND S WV
LATE THIS AFTN. ROLLED WITH LATEST LAMP GUIDANCE FOR TEMPS TDY
RESULTING IN UPR 40S TO LWR 50S OUTSIDE OF MTNS...WITH GENERALLY
40S IN HIGHER ELEVATIONS. KEPT A SMALL WINDOW THIS MORNING FOR A
RA/SN MIX AT SNOWSHOE BUT THIS IS LOOKING DOUBTFUL AS MDLS HAVE
COME IN SLIGHTLY WARMER.
MAY STILL SEE SOME STRATOCU ACROSS SE OH AND N WV THIS EVE BEFORE
TRYING TO DISSIPATE BY MIDNIGHT. HOWEVER...ANOTHER UPR LVL
DISTURBANCE WILL BE QUICKLY APPROACHING IN BASE OF MEAN TROF. THIS
SPELLS HEADACHES IN MINT FCST TONIGHT. MOS NUMBERS CONT TO COME IN
ON THE COLD SIDE WITH GENERALLY LOW TO MID 30S OUTSIDE OF THE
MTNS...WITH UPR 20S TO LWR 30S IN HIGH TERRAIN. HOWEVER...MDLS SHOW
MID/HI CLDS QUICKLY STREAMING NE INTO THE AREA LATE TONIGHT...WITH
GFS MOST BULLISH ON THIS. CRITICAL ARRIVAL TIME SLATED FOR 09-12Z.
CIRRUS CURRENTLY ON GRAVEYARD SHIFT ALLOWED TEMPS TO SPIKE UPWARDS
OF 5F AS IT MOVED IN...NOT HANDLED BY MDLS. ANOTHER FACTOR IS DRIER
AIR IN FORM OF LWR DWPTS TRYING TO SNEAK INTO E OH WHICH WOULD
RESULT IN TOO HIGH OF DWPT DEPRESSION FOR FROST SHOULD 32F OR LWR
NOT BE ACHIEVED. REGARDLESS...TOO MUCH UNCERTAINTY TO MAKE ANY CHGS
TO HEADLINES WITH THIS PACKAGE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MODELS ARE SHOWING A WAVE SKIRTING SOUTHEASTERN PORTIONS OF THE
FORECAST AREA MONDAY. DIFFERENCES STILL EXIST ON HOW FAR NORTH THE
PRECIPITATION WILL MAKE IT. WILL ADD SOME POPS IN THIS REGION BUT
KEEP IN THE CHANCE CATEGORY DUE TO THE UNCERTAINTY.
NAM IS SHOWING YET ANOTHER WAVE MONDAY NIGHT INTO TUESDAY. OTHER
MODELS DO NOT HAVE THIS FEATURE CAUSING PRECIPITATION IN THE
FORECAST AREA. LAST NIGHT NAM WAS FURTHER NORTH THAN OTHER MODELS
WITH WAVE ON MONDAY...AND OTHER MODELS HAVE NOW TRENDED TOWARD THE
NAM. THEREFORE...WILL GIVE THE NAM MORE WEIGHT THAN NORMAL IN THIS
SITUATION AND ADD SOME SLIGHT CHANCE POPS. THIS ALSO EFFECTS
TEMPERATURES AND FROST POTENTIAL.
MODELS IN FAIRLY GOOD AGREEMENT WITH A COLD FRONT MOVING THROUGH ON
WEDNESDAY. WILL ADJUST TIMING OF POPS SOME DUE TO SUCH GOOD
AGREEMENT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE GFS IS SHOWING A STRONG DEEP H5 TROUGH WITH STRONG ELONGATED
VORT MAX AROUND ITS PERIPHERY ACROSS THE GREAT LAKES AND PA. THIS
SYSTEM WILL BRING A COLD FRONT ACROSS SOUTHEAST OH AND WV
WEDNESDAY. THE GFS/ECMWF CONTINUE TO SHOW PRESSURE GRADIENT
TIGHTENING UP ON TUESDAY NIGHT/WEDNESDAY AHEAD OF A COLD FRONT.
THIS SOUTHWEST FLOW WILL INCREASE H85 TEMPERATURES ABOUT 7 DEGREES
CELSIUS BY 12Z WED. NOTICED NO MAJOR CHANGES FROM HPC GUIDANCE FROM
PREVIOUS FCST. KEPT CHANCE POPS FOR WED AS WITH RAIN SHOWERS AND NO
THUNDER. THESE CHANCE POPS WILL DIMINISH WED NIGHT...AND EXIT EAST
TO THE NORTHEAST MOUNTAINS BY THURSDAY MORNING. MOISTURE LOOKS
LIMITED ATTM...AND H85 TEMPERATURES REMAIN ABOVE FREEZING SUGGESTING
ALL PCPN WILL FALL AS LIQUID.
EXPECT BROAD AND DRY HIGH PRESSURE OVERHEAD THURSDAY FOR MOSTLY
CLEAR SKIES...H85 TEMPS AROUND 9C PER GFS/ECMWF.
ANOTHER BUT WEAKER AND LESS AMPLIFY H5 TROUGH WILL CROSS THE GREAT
LAKES REGION FURTHER NORTH OUR AREA ON FRIDAY. MODELS SUGGEST A
ANOTHER BUT WEAKER COLD FRONT WITH LIMITED MOISTURE COULD PRODUCE
LOW CHANCES FRIDAY...WHILE A SOUTHERN STREAM SYSTEM LIFTS NORTHEAST
WITH A POSSIBLE WARM FRONT UNDER SOUTHWEST FLOW NEXT SATURDAY.
INTRODUCED CHANCE POPS SAT AND SAT NIGHT ACCORDINGLY.
USED HPC GUIDANCE FOR TEMPS AS A BASED...TWEAKING UP TEMPS UNDER
SOUTHWEST FLOW...AND DOWN DURING CLEAR NIGHTS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
12Z SUNDAY THROUGH 12Z MONDAY... AN UPR LVL DISTURBANCE WILL MOVE
THROUGH TDY. BULK OF PRECIPITATION WITH THIS WILL BE MAINLY
CONFINED TO SW VA AND THE WV MTNS...WITH CIGS GRADUALLY
DETERIORATING TO MVFR...THEN IFR...ESPECIALLY ACROSS THE HIGHER
TERRAIN AFTER 12 TO 15Z. ELSEWHERE...MID/HI CLDS WILL PREVAIL
THRU MORNING. BY EARLY THIS AFTN THOUGH...CIGS MAY LWR INTO MVFR
RANGE ACROSS SE OH AND N WV...TO INCLUDE KCRW...KPKB...AND KCKB AS
UPR WAVE MOVES ACROSS. SHRA CHCS TOO LOW TO INCLUDE IN THOSE TAF
SITES ATTM.
BULK OF PRECIPITATION WILL BEGIN TO MOVE EAST OF THE AREA BY
18Z. FLIGHT CONDITIONS WILL IMPROVE TO MVFR BY 00Z AT MTN
SITES AND KCKB...WITH A RETURN TO VFR CONDITIONS ACROSS REMAINDER
OF AREA BY 21Z.
SOME LINGERING LLVL MOISTURE IN FORM OF 4 TO 5 THSD FT STRATOCU
MAY LINGER THIS EVE ACROSS THE MTNS. OTHERWISE SOME EVE CLEARING
WILL GIVE WAY TO AN INCREASE ONCE AGAIN OF MID/HI CLDS BY 12Z
MON...MAINLY ACROSS THE S. SOME MVFR FG POSSIBLE ACROSS RVR
VALLEYS LATE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF PRECIPITATION AND ONSET
OF LOWER CIGS TODAY MAY VARY FROM FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY M H H H M H H H H M H H
HTS CONSISTENCY H H H H H H H M H H H H
BKW CONSISTENCY H M L M L L H H H M H M
EKN CONSISTENCY H H H H M M M M H H H M
PKB CONSISTENCY H H H H H H H M M M M H
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 12Z MONDAY...
IFR CIGS POSSIBLE MONDAY ACROSS HIGHER TERRAIN.
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
WVZ035>039-046-047.
OH...FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
OHZ066-067.
KY...NONE.
VA...NONE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
WVZ035>039-046-047.
OH...FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
OHZ066-067.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
949 PM EDT MON OCT 8 2012
.SYNOPSIS...
A LARGE UPPER LEVEL TROUGH WILL REMAIN POSITIONED OVER THE GREAT
LAKES THROUGH THE END OF THIS WEEK. SHORTWAVES ROTATING AROUND THE
BASE OF THIS TROUGH WILL PUSH REINFORCING COLD FRONTS THROUGH
PENNSYLVANIA ON WEDNESDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATEST RUC AND NAM HIGH-RES RUNS PAINT A MUCH-CLOUDIER PICTURE FOR
THE OVERNIGHT THAN PREV RUNS DID. SRLY FLOW COULD CONTINUE TO
BRING AMPLE MOISTURE INTO THE CENTRAL MTS AND AS FAR W AS
JST/FIG/BFD. HOWEVER...THIS IS NOT SET QUITE YET. MUCH DRY AIR
OVERHEAD AND SUBSIDENCE BEHIND THE WEAK WAVE OFF THE COAST WILL
TRY TO BALANCE THIS POTENTIAL FLY IN THE FORECAST OINTMENT. WILL
BEND THE FCST MORE-CLOUDY IN THE CENTRAL AND WEST BUT HOLD ONTO
THE REST OF THE FCST DETAILS FOR THE TIME-BEING. CERTAINLY...IF
THE LOW CLOUDS DO REINVIGORATE...THE TEMPS WOULD NEED TO BE
BROUGHT UP AND THE FROST/FREEZE WORRIES WOULD JUST MELT AWAY
/BAD PUN/. WILL REVISIT THIS TREND IN THE NEXT FEW HOURS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
LOW CLOUDS EARLY IN THE MORNING SHOULD BURN AWAY THROUGH THE
MORNING...AS HIGH CLOUDS WILL BE OFF TO THE EAST AND THE WEAK SUN
AND SUBSIDENCE SHOULD WORK OVER THE CLOUDS. ANY CHANCE OF RAIN WILL
BE SMALL...EARLY AND OVER THE FAR SE...OTHERWISE WE WILL BE DRYING
OUT COURTESY OF THE WEAK RIDGE OF HIGH PRESSURE. SUNSHINE WILL BE
ON THE INCREASE FROM CENTRAL AREAS EASTWARD BUT IT WILL STAY COOL
WITH HIGHS ONLY AVERAGING IN THE 50S. THIS IS ABOUT 5-10 DEG BELOW
NORMAL FOR THIS TIME OF YEAR.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
EXCELLENT MDL AGREEMENT WITH REGARDS TO TIMING OF NEXT SHORTWAVE
ROUNDING BASE OF GRT LKS TROF ON WEDNESDAY. THIS MOISTURE-STARVED
SYSTEM AND ASSOC COLD FRONT SHOULD SWEEP THROUGH CENTRAL PA DURING
THE DAYLIGHT HRS...ACCOMPANIED BY A FEW SHOWERS...PRIMARILY OVR
THE N MTNS.
WED NIGHT WILL BE ON THE COOL SIDE AGAIN...MAY BE JUST ENOUGH
WIND TO KEEP MOST AREAS ABOVE FREEZING.
HIGH CONFIDENCE OF SUNNY/DRY WX THURSDAY...WHEN ALL MDL DATA
TRACKS SFC RIDGE ACROSS OUR AREA.
THU NIGHT MAY FEATURE FROST...FREEZE ISSUES...ESPECIALLY
AWAY FROM NW PA...IF THE GRADIENT AND CLD COVER IS SLOW
TO INCREASE.
ANOTHER MOISTURE- STARVED COLD FRONT FOR FRIDAY...WITH
FAIRLY LOW POPS.
FRI NITE COULD BE ANOTHER COLD ONE AS HIGH PRES WITH LOW PW AT
AIR DRIFTS OVR THE STATE.
MODELS HINT AT A PATTERN CHANGE BY LATE IN THE WEEKEND.
WARMER WX APPEARS LIKELY BY SUNDAY AS HIGH PRESSURE MOVES
OFF THE COAST AND RETURN SW FLOW DEVELOPS. SOME SHOWERS POSSIBLE
WITH WARM FRONT SATURDAY NIGHT...AND SUNDAY WITH THE COLD FRONT.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
SCATTERED SHOWERS CONTINUE TO FADE AND DISSIPATE AS THE EVENING
CONTINUES. EXPECT THE SFC LOW TO BE WEAK AND REMAIN WELL SOUTH OF
PA...WITH GRADUALLY LOWERING CEILINGS LIKELY FROM SEGA SOUTH AND
EAST. HAVE BROUGHT ALL TERMINALS DOWN TO MVFR/IFR BY LATE EVENING.
BFD...WITH MOIST SOUTHERLY FLOW THAT CONTINUES TO ADVECT
NORTHWARD...SHOULD HAVE BFD SEE REDUCING CIGS AND VSBYS BY 06Z
THROUGH 15Z.
CONDITIONS WILL BEGIN TO IMPROVE FROM WEST TO EAST TUESDAY MORNING
THROUGH ABOUT MID DAY AS THE WEAK STORM SYSTEM MOVES OFF TOWARD
NEW ENGLAND AND WEAK HIGH PRESSURE MOVES INTO THE REGION.
OUTLOOK...
WED...VFR...BUT MVFR POSS IN SCATTERED SHOWERS WITH A COLD FRONTAL
PASSAGE...ESPECIALLY WESTERN HIGH TERRAIN.
THU...VFR.
FRI...VFR...BUT MVFR POSS IN SCATTERED SHOWERS WITH A COLD FRONTAL
PASSAGE...ESPECIALLY WESTERN HIGH TERRAIN.
SAT...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING FROM 3 AM TO 8 AM EDT TUESDAY FOR PAZ004>006-
010-011-017-024-037.
FROST ADVISORY FROM 3 AM TO 8 AM EDT TUESDAY FOR PAZ012-018-
019-025-026-033>035-041-042-045-046.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
724 AM EDT SUN OCT 7 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL TRACK ACROSS THE REGION FROM THE
WEST AND OVER A LAYER OF COOLER AIR. THIS WILL RESULT IN A WET AND
COOL DAY SUNDAY. MORE RAIN AND COOL TEMPERATURES ARE EXPECTED MONDAY
AS ANOTHER UPPER LEVEL DISTURBANCE ENTERS FROM THE SOUTHWEST.
BY TUESDAY...DRIER CONDITIONS WILL ARRIVE AND CONTINUE INTO THE
LATER PART OF THE WEEK UNDER HIGH PRESSURE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM EDT SUNDAY...
WATER VAPOR SATELLITE IMAGERY INDICATES A WEAK SHORTWAVE ACROSS
EASTERN KY INTO CENTRAL TN. THIS FEATURE IS IN ADVANCE OF A STRONGER
UPPER LEVEL DISTURBANCE LOCATED ACROSS IOWA INTO MO. HRRR AND LOCAL
WRF MODELS DEPICT THIS AREA OF RAIN WELL...UNDER THE RR QUAD OF A
LIFTING UPPER LEVEL JET. WITH GOOD ISENTROPIC LIFT CONTINUING INTO
EARLY AFTERNOON AND THE APPROACH OF MIDWESTERN UPPER LEVEL
SHORTWAVE...PRECIP SHOULD EXPAND IN COVERAGE. AS A RESULT...WILL
CONTINUE TO CARRY LIKELY POPS INTO THE EARLY AFTERNOON.
BEHIND THIS SYSTEM...LOW LEVEL WINDS VEER TO THE NORTHWEST AND
ISENTROPIC DOWNGLIDE BEINGS LATE THIS AFTERNOON/EARLY THIS
EVENING...WHICH WILL GRADUALLY BRING AN END TO THE PRECIP.
CLOUDS...WEAK CAA...AND PRECIP WILL KEEP TEMPERATURES FROM RISING
MUCH AT ALL TODAY. IN FACT...TEMPS MAY DROP TODAY.
THEREFORE...LEANED TOWARD THE COOLER MAV AND LOCALLY DERIVED MOS
GUIDANCE FOR HIGHS TODAY.
THE NEXT UPPER LEVEL SYSTEM ZIPPING INTO THE LOWER OHIO VALLEY BY
LATE SUNDAY NIGHT/EARLY MONDAY MORNING WILL BACK LOW LEVEL WINDS AND
SET UP A BAROCLINIC ZONE ACROSS THE SOUTHERN PORTION OF OUR FORECAST
AREA LATE TONIGHT. THIS MAY GENERATE SOME LIGHT PRECIP IN THIS
REGION...AND KEPT SMALL POPS HERE LATE TONIGHT. IN THE NORTH...THE
THREAT FOR FROST APPEARS LOW WITH A WET GROUND/WARM SOIL TEMPS AND
CLOUD COVER. IF ANY CLEARING CAN BE MAINTAINED...SOME PATCHY FROST
IN THE DEEP MOUNTAIN VALLEYS FROM BURKES GARDEN INTO SOUTHEAST WV
MAY DEVELOP.
WITH THE INCREASE IN CLOUDS...USED A MAV/MET MIX FOR LOWS WHICH ARE
CLOSE TO OUR LOCALLY DERIVED MOS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
A JET COUPLET PROVIDING DIFFLUENCE ALOFT WILL COMBINE WITH
FRONTOGENESIS JUST ABOVE THE GROUND ACROSS SE WEST VA TO GENERATE
LIGHT RAIN ON MONDAY MOSTLY BLUE RIDGE AND WEST. ALTHOUGH QPF WILL
BE SMALL...POSSIBLY ONLY A FEW HUNDREDTHS...SPOTTY DRIZZLE WILL HELP
TO MAKE THIS A DAMP AND COOL DAY. WITH PRECIP AND E TO NE FLOW
CONTINUING...CAN`T SEE TEMPS GOING MUCH OF ANYWHERE...AND ALL OF THE
GUIDANCE WITH THE EXCEPTION OF THE LOCALLY BIAS CORRECTED ECMWF
LOOKS TOO WARM. QUITE POSSIBLE SOME OF THE COOLEST SPOTS DON`T EVEN
REACH 45F WITH THE POSSIBILITY THAT MANY PLACES DON`T REACH 50F.
CLOUDS BREAKING LATE MONDAY NIGHT SHOULD KEEP TUESDAY MORNING LOW
TEMP A FEW WARMER THAN GUIDANCE...AND A RATHER WET AND WARM GROUND
WITH TEMPS NOT FALLING INTO THE 30S UNTIL LATE SHOULD PRECLUDE ANY
FROST. WITH ABUNDANT LLVL MOISTURE AND EASTERLY COMPONENT CONTINUING
BLUE RIDGE AND EAST...HELD ONTO CLOUDS AND WENT WITH MAX T CLOSER TO
THE 2M NAM VALUES TUESDAY. WEDGE FIGURES TO BE SLOWER TO LIFT OUT
THAN OTHER MODELS DEPICT. THIS COULD BE ONE OF THOSE DAYS WHERE BCB
IS WARMER THAN ROA AND LWB IS WARMER THAN DAN/LYH. CLOUDS SHOULD
BREAK WEST OF THE BLUE RIDGE WITH MORE WESTERLY COMPONENT TUESDAY.
SHOWERS SHOULD CRUMBLE ACROSS WEST VA WITH FRONT THAT APPROACHES ON
WEDNESDAY WITH DEEP DOWNSLOPING FLOW AHEAD OF IT. BIG TEMP REBOUND
THOUGH BLUE RIDGE AND EAST...EASILY THE BEST DAY OF THE NEXT SEVERAL
WITH MAX T ONCE AGAIN IN THE 70S ON WEDNESDAY. A BETTER DRY PUNCH
SETS THE STAGE FOR SOME NEAR FREEZING TEMPS PERHAPS THURSDAY MORNING
ACROSS SE WEST VA...EXTREME SW VA AND NW NC.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 400 PM EDT SATURDAY...
ANOTHER FRONTAL BOUNDARY APPROACHES DURING THE WEEKEND AND
ARRIVES EARLY NEXT WEEK...ALLOWING TEMPERATURES TO MODERATE.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
AS OF 715 AM EDT SUNDAY...
WIDESPREAD SHOWERS EARLY THIS MORNING WITH AREAS OF MVFR CEILINGS WILL
CONTINUE INTO THE EARLY AFTERNOON DUE AN APPROACHING UPPER LEVEL DISTURBANCE.
ONCE THE UPPER LEVEL SYSTEM MOVES EAST AND WEAK LOW LEVEL
NORTHWEST FLOW FORMS...CEILINGS TO RISE LATE THIS AFTERNOON AND THIS
EVENING TO VFR CONDITIONS.
THESE IMPROVING CONDITIONS WILL ONLY BE TEMPORARY AS ANOTHER UPPER
LEVEL SYSTEM MOVING OVER THE REGION MONDAY WILL BRING WIDESPREAD
MVFR/IFR CIGS AND LIGHT PRECIPITATION. HIGH PRESSURE BUILDING
OVER THE AREA FOR TUESDAY WILL FINALLY BRING VFR CONDITIONS
THAT ARE EXPECTED TO LAST THROUGH THURSDAY...ALTHOUGH A PERIOD OF
MVFR CIGS POSSIBLE IN THE MTNS WITH A COLD FRONTAL PASSAGE
WEDNESDAY.
&&
.EQUIPMENT...
THE KFCX DOPPLER RADAR...WHICH SERVES ROANOKE AND THE SURROUNDING
AREAS...WILL REMAIN DOWN FOR THE NEXT FEW DAYS AS THE INSTALLATION
OF THE NEW DUAL-POL TECHNOLOGY CONTINUES. THE RADAR MAY RETURN TO
SERVICE AS EARLY AS THE MIDDLE OF NEXT WEEK.
NEIGHBORING DOPPLER RADARS AT STERLING VA (KLWX)...WAKEFIELD VA
(KAKQ)...RALEIGH NC (KRAX)...GREENVILLE-SPARTANBURG SC
(KGSP)...MORRISTOWN TN (KMRX)...AND CHARLESTON WV (KRLX) WILL
CONTINUE TO PROVIDE COVERAGE OVER PARTS OF THE KFCX AREA DURING
THIS TIME FRAME.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...PH
SHORT TERM...KM
LONG TERM...KK
AVIATION...PH
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
357 AM EDT SUN OCT 7 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL TRACK ACROSS THE REGION FROM THE
WEST AND OVER A LAYER OF COOLER AIR. THIS WILL RESULT IN A WET AND
COOL DAY SUNDAY. MORE RAIN AND COOL TEMPERATURES ARE EXPECTED MONDAY
AS ANOTHER UPPER LEVEL DISTURBANCE ENTERS FROM THE SOUTHWEST.
BY TUESDAY...DRIER CONDITIONS WILL ARRIVE AND CONTINUE INTO THE
LATER PART OF THE WEEK UNDER HIGH PRESSURE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM EDT SUNDAY...
WATER VAPOR SATELLITE IMAGERY INDICATES A WEAK SHORTWAVE ACROSS
EASTERN KY INTO CENTRAL TN. THIS FEATURE IS IN ADVANCE OF A STRONGER
UPPER LEVEL DISTURBANCE LOCATED ACROSS IOWA INTO MO. HRRR AND LOCAL
WRF MODELS DEPICT THIS AREA OF RAIN WELL...UNDER THE RR QUAD OF A
LIFTING UPPER LEVEL JET. WITH GOOD ISENTROPIC LIFT CONTINUING INTO
EARLY AFTERNOON AND THE APPROACH OF MIDWESTERN UPPER LEVEL
SHORTWAVE...PRECIP SHOULD EXPAND IN COVERAGE. AS A RESULT...WILL
CONTINUE TO CARRY LIKELY POPS INTO THE EARLY AFTERNOON.
BEHIND THIS SYSTEM...LOW LEVEL WINDS VEER TO THE NORTHWEST AND
ISENTROPIC DOWNGLIDE BEINGS LATE THIS AFTERNOON/EARLY THIS
EVENING...WHICH WILL GRADUALLY BRING AN END TO THE PRECIP.
CLOUDS...WEAK CAA...AND PRECIP WILL KEEP TEMPERATURES FROM RISING
MUCH AT ALL TODAY. IN FACT...TEMPS MAY DROP TODAY.
THEREFORE...LEANED TOWARD THE COOLER MAV AND LOCALLY DERIVED MOS
GUIDANCE FOR HIGHS TODAY.
THE NEXT UPPER LEVEL SYSTEM ZIPPING INTO THE LOWER OHIO VALLEY BY
LATE SUNDAY NIGHT/EARLY MONDAY MORNING WILL BACK LOW LEVEL WINDS AND
SET UP A BAROCLINIC ZONE ACROSS THE SOUTHERN PORTION OF OUR FORECAST
AREA LATE TONIGHT. THIS MAY GENERATE SOME LIGHT PRECIP IN THIS
REGION...AND KEPT SMALL POPS HERE LATE TONIGHT. IN THE NORTH...THE
THREAT FOR FROST APPEARS LOW WITH A WET GROUND/WARM SOIL TEMPS AND
CLOUD COVER. IF ANY CLEARING CAN BE MAINTAINED...SOME PATCHY FROST
IN THE DEEP MOUNTAIN VALLEYS FROM BURKES GARDEN INTO SOUTHEAST WV
MAY DEVELOP.
WITH THE INCREASE IN CLOUDS...USED A MAV/MET MIX FOR LOWS WHICH ARE
CLOSE TO OUR LOCALLY DERIVED MOS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
A JET COUPLET PROVIDING DIFFLUENCE ALOFT WILL COMBINE WITH
FRONTOGENESIS JUST ABOVE THE GROUND ACROSS SE WEST VA TO GENERATE
LIGHT RAIN ON MONDAY MOSTLY BLUE RIDGE AND WEST. ALTHOUGH QPF WILL
BE SMALL...POSSIBLY ONLY A FEW HUNDREDTHS...SPOTTY DRIZZLE WILL HELP
TO MAKE THIS A DAMP AND COOL DAY. WITH PRECIP AND E TO NE FLOW
CONTINUING...CAN`T SEE TEMPS GOING MUCH OF ANYWHERE...AND ALL OF THE
GUIDANCE WITH THE EXCEPTION OF THE LOCALLY BIAS CORRECTED ECMWF
LOOKS TOO WARM. QUITE POSSIBLE SOME OF THE COOLEST SPOTS DON`T EVEN
REACH 45F WITH THE POSSIBILITY THAT MANY PLACES DON`T REACH 50F.
CLOUDS BREAKING LATE MONDAY NIGHT SHOULD KEEP TUESDAY MORNING LOW
TEMP A FEW WARMER THAN GUIDANCE...AND A RATHER WET AND WARM GROUND
WITH TEMPS NOT FALLING INTO THE 30S UNTIL LATE SHOULD PRECLUDE ANY
FROST. WITH ABUNDANT LLVL MOISTURE AND EASTERLY COMPONENT CONTINUING
BLUE RIDGE AND EAST...HELD ONTO CLOUDS AND WENT WITH MAX T CLOSER TO
THE 2M NAM VALUES TUESDAY. WEDGE FIGURES TO BE SLOWER TO LIFT OUT
THAN OTHER MODELS DEPICT. THIS COULD BE ONE OF THOSE DAYS WHERE BCB
IS WARMER THAN ROA AND LWB IS WARMER THAN DAN/LYH. CLOUDS SHOULD
BREAK WEST OF THE BLUE RIDGE WITH MORE WESTERLY COMPONENT TUESDAY.
SHOWERS SHOULD CRUMBLE ACROSS WEST VA WITH FRONT THAT APPROACHES ON
WEDNESDAY WITH DEEP DOWNSLOPING FLOW AHEAD OF IT. BIG TEMP REBOUND
THOUGH BLUE RIDGE AND EAST...EASILY THE BEST DAY OF THE NEXT SEVERAL
WITH MAX T ONCE AGAIN IN THE 70S ON WEDNESDAY. A BETTER DRY PUNCH
SETS THE STAGE FOR SOME NEAR FREEZING TEMPS PERHAPS THURSDAY MORNING
ACROSS SE WEST VA...EXTREME SW VA AND NW NC.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 400 PM EDT SATURDAY...
ANOTHER FRONTAL BOUNDARY APPROACHES DURING THE WEEKEND AND
ARRIVES EARLY NEXT WEEK...ALLOWING TEMPERATURES TO MODERATE.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AS OF 130 AM EDT SUNDAY...
AN APPROACHING UPPER LEVEL DISTURBANCE WILL ENHANCE THE CHANCES OF
RAIN TODAY. IN ADVANCE OF THIS SYSTEM...CEILINGS HAVE BEEN
DROPPING INTO THE MVFR CATEGORY...AND EVEN IFR CATEGORY IN SOME
MOUNTAIN LOCATIONS IN NORTHWEST NORTH CAROLINA. EXPECT THIS
LOWERING TREND TO CONTINUE...ESPECIALLY IN THE MOUNTAINS EARLY
THIS MORNING...WITH RAIN DEVELOPING BETWEEN 10-13Z.
MVFR TO POCKETS OF IFR CEILINGS WILL BE FOUND THROUGH THE DAY.
ONCE THE UPPER LEVEL SYSTEM MOVES EAST AND WEAK LOW LEVEL
NORTHWEST FLOW FORMS...EXCEPT A CEILINGS TO RISE THIS EVENING.
THESE IMPROVING CONDITIONS WILL ONLY BE TEMPORARY AS ANOTHER UPPER
LEVEL SYSTEM MOVING OVER THE REGION MONDAY WILL BRING WIDESPREAD
MVFR/IFR CIGS AND LIGHT PRECIPITATION. HIGH PRESSURE BUILDING
OVER THE AREA FOR TUESDAY WILL FINALLY BRING VFR CONDITIONS
THAT ARE EXPECTED TO LAST THROUGH THURSDAY...ALTHOUGH A PERIOD OF
MVFR CIGS POSSIBLE IN THE MTNS WITH A COLD FRONTAL PASSAGE
WEDNESDAY.
&&
.EQUIPMENT...
THE KFCX DOPPLER RADAR...WHICH SERVES ROANOKE AND THE SURROUNDING
AREAS...WILL REMAIN DOWN FOR THE NEXT FEW DAYS AS THE INSTALLATION
OF THE NEW DUAL-POL TECHNOLOGY CONTINUES. THE RADAR MAY RETURN TO
SERVICE AS EARLY AS THE MIDDLE OF NEXT WEEK.
NEIGHBORING DOPPLER RADARS AT STERLING VA (KLWX)...WAKEFIELD VA
(KAKQ)...RALEIGH NC (KRAX)...GREENVILLE-SPARTANBURG SC
(KGSP)...MORRISTOWN TN (KMRX)...AND CHARLESTON WV (KRLX) WILL
CONTINUE TO PROVIDE COVERAGE OVER PARTS OF THE KFCX AREA DURING
THIS TIME FRAME.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KM/PM
NEAR TERM...PH
SHORT TERM...KM
LONG TERM...KK
AVIATION...PH
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
703 PM CDT MON OCT 8 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
235 PM CDT MON OCT 8 2012
MAIN FORECAST CONCERN IS ON RAIN CHANCES FOR TONIGHT AND TUESDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE NORTHEAST PACIFIC AND TROUGHING ACROSS
CENTRAL AND EASTERN CANADA. WITHIN THIS TROUGH...THERE ARE TWO
SHORTWAVE TROUGHS OF NOTE. THE FIRST IS OVER NORTHERN MINNESOTA...
WITH AN ASSOCIATED 998MB SURFACE LOW OVER NORTHWEST MINNESOTA. DPVA
AHEAD OF THE SHORTWAVE IN CONJUNCTION WITH WARM ADVECTION/ISENTROPIC
LIFT HAS SUPPORTED A LARGE AREA OF ALTOSTRATUS ACROSS MINNESOTA INTO
THE NORTHWEST HALF OF WISCONSIN. DRY LOW LEVEL AIR SEEN ON THE 12Z
MPX SOUNDING AS WELL AS SURFACE RELATIVE HUMIDITIES IN THE 25-40
PERCENT RANGE HAS KEPT THE SOUTHERN MINNESOTA DRY DESPITE LIGHT
RETURNS ON RADAR. BREEZY SOUTHWEST WINDS ARE ALSO OCCURRING ACROSS
THE FORECAST AREA AS A RESULT OF A TIGHT PRESSURE GRADIENT. THESE
SOUTHWEST WINDS ARE ADVECTING WARMER AIR INTO THE AREA...NOTED BY
850MB TEMPS PER THE RAP THAT HAVE CLIMBED TO 4-6C AFTER STARTING OFF
AT 1-3C ACCORDING TO 12Z RAOBS. COLD FRONT ASSOCIATED WITH THE LOW
PRESSURE AREA APPROACHING SIOUX FALLS SOUTH DAKOTA. THE NEXT
SHORTWAVE TROUGH OF NOTE...WHICH LOOKS QUITE POTENT IN WATER
VAPOR...IS IN SOUTHERN SASKATCHEWAN. A 100-120 KT JET NEAR 250MB WAS
LOCATED ON THE WEST/SOUTHWEST SIDE OF THIS SHORTWAVE.
TONIGHT AND TUESDAY...THE POTENT SHORTWAVE IN SASKATCHEWAN MODELS
SHOW DROPPING DOWN INTO THE DAKOTAS TONIGHT...THEN INTENSIFYING AND
TURNING NEUTRAL TILT AS IT CROSSES MINNESOTA INTO FAR WESTERN
WISCONSIN DURING THE DAY TUESDAY. AS THIS SHORTWAVE APPROACHES
TONIGHT...IT HELPS TO SLOW DOWN THE CURRENT EASTWARD PROGRESS OF THE
COLD FRONT NEAR SIOUX FALLS. IN FACT...BY 12Z...THE FRONT MAY JUST
BE GETTING INTO SOUTHEAST MN. AS SUCH...A MILD NIGHT COMPARED TO
WHAT HAS BEEN SEEN RECENTLY IS ON TAP TONIGHT...AIDED BY A
CONTINUING SOUTHWEST BREEZE AND PLENTY OF CLOUDS. THEREFORE...STAYED
ON THE WARM SIDE OF GUIDANCE. PRECIPITATION CHANCES TONIGHT ARE VERY
QUESTIONABLE BECAUSE OF THE SLOW FRONTAL PROGRESS. WHEN HEADING INTO
THE COLD SEASON...MOST PRECIPITATION FALLS POST-COLD FRONTAL BECAUSE
OF COLD AIR UNDERCUTTING THE WARM AIR. IN THIS CASE...THE
FRONTOGENESIS FORCING WHICH DOES STRENGTHEN THROUGH THE NIGHT ENDS
UP STAYING MOSTLY WEST OF THE AREA. AS SUCH...HAVE CONFINED THE
PRECIPITATION CHANCES TO MOSTLY LATE TONIGHT AND OVER THE NORTHWEST
1/3 OF THE AREA. IN ADDITION...HAVE KEPT THE CHANCES IN THE 20-40
RANGE AS CONFIDENCE IS LOW IN GETTING THE AIR SATURATED AND THE
FRONT INTO THE AREA. NOW THINGS ARE A LOT DIFFERENT ON TUESDAY. THE
FRONTOGENESIS ZONE ON TUESDAY IS PROGGED TO STRENGTHEN
DRAMATICALLY...CAUSED BY THE APPROACHING SHORTWAVE. CROSS-SECTIONS
SHOW A NICE FRONTOLYSIS/FRONTOGENESIS COUPLET WHICH YIELDS STRONG
UPWARD VERTICAL MOTION. SO ANTICIPATING THAT AS THE SHORTWAVE MOVES
IN AND PUSHES THE FRONT EAST...SHOULD SEE A BAND OF RAIN BEHIND IT.
IN FACT...MOST OF THE AREA LOOKS TO GET RAIN NOW FOR TUESDAY...
THOUGH NORTHWEST SECTIONS SHOULD DRY OUT IN THE AFTERNOON AS THE
FRONTOGENESIS FORCING HEADS EAST. WITH THE FRONT AND RAIN MOVING
THROUGH...A NON-DIURNAL TREND IS REQUIRED. PLUS...850MB TEMPS FALL
FROM 2-6C AT 12Z TO 0 TO -2C AT 00Z. HIGHS WILL TOP OUT IN THE UPPER
40S TO MIDDLE 50S AT BEST...AND FOR SOME LOCATIONS THIS MAY BE A
MORNING HIGH.
TUESDAY NIGHT AND WEDNESDAY...THE FORECAST AREA IS PROGGED TO SIT
UNDER UPPER LEVEL TROUGHING FOR MUCH OF TUESDAY NIGHT...IN THE WAKE
OF THE POTENT SHORTWAVE PUSHING EAST OF THE AREA DURING THE EVENING.
NORTHERLY LOW LEVEL FLOW UNDER THE UPPER TROUGH WILL HELP DRIVE
850MB TEMPS FURTHER DOWN...REACHING -4 TO -7C BY 12Z WEDNESDAY.
ACCOMPANYING THE COLDER AIR SHOULD BE A LOW STRATUS DECK...
PARTICULARLY ACROSS WISCONSIN. SO AFTER PERHAPS A BRIEF PERIOD OF
CLEARING IN THE EVENING IN THE WAKE OF THE PRECIPITATION...EXPECT
CLOUDS TO INCREASE. THE COMBINATION OF THESE CLOUDS AND A DECENT
NORTHERLY BREEZE WILL HELP TO KEEP TEMPERATURES FROM BOTTOMING OUT
TO MUCH. HAVE LEANED TOWARDS THE WARMER SIDE OF GUIDANCE AS A RESULT
WITH LOWS IN THE UPPER 20S TO LOWER 30S. THIS STRATUS DECK WILL
DISSIPATE ON WEDNESDAY AS A SURFACE HIGH PRESSURE RIDGE AXIS SLIDES
EAST ACROSS THE AREA. IN FACT...BY 00Z THURSDAY...STRENGTHENING
SOUTHWEST BREEZES ARE EXPECTED AHEAD OF YET ANOTHER POTENT SHORTWAVE
DROPPING DOWN INTO SOUTH CENTRAL CANADA. THESE BREEZES WILL HELP
ADVECT WARMER AIR INTO THE AREA...WITH 850MB TEMPS CLIMBING TO 0 TO
-3C BY 00Z. PLENTY OF SUN AND DRY AIR SHOULD ALLOW FOR PLENTY OF
MIXING...BUT GIVEN THE COOL 850MB TEMPS...AT BEST HIGHS MAY REACH
THE MID 50S AND THAT IS IN FAR SOUTHWESTERN PORTIONS OF THE FORECAST
AREA WHERE THE WARMEST AIR COMES IN LATE.
WEDNESDAY NIGHT AND THURSDAY...THE NEXT POTENT SHORTWAVE THAT
DROPPED DOWN INTO SOUTH CENTRAL CANADA ON WEDNESDAY IS FORECAST TO
HEAD TO THE EAST...VERSUS DIG DOWN TOWARDS THE FORECAST AREA LIKE
THE PAST COUPLE HAVE DONE. AS SUCH...ALL FORCING AND EXPECTED
PRECIPITATION WITH IT WILL STAY WELL NORTH OF THE FORECAST AREA.
HOWEVER...A COLD FRONT IS STILL SLATED TO COME THROUGH. SOME TIMING
DIFFERENCES ON THE SPEED...WITH THE 08.12Z NAM THE SLOWEST NOT
SHOWING FULL PASSAGE UNTIL THURSDAY EVENING WHILE THE 08.12Z
GFS/ECMWF/CANADIAN/UKMET SUGGESTING MAINLY DURING THURSDAY MORNING.
WILL FOLLOW THE MAJORITY GROUP AT THIS TIME AND CONSIDER THE NAM AN
OUTLIER. NO MATTER WHAT MODEL FOLLOWED...IN THE COLD FRONT
WAKE...YET ANOTHER COLD CANADIAN HIGH PRESSURE AREA IS PROGGED TO
DROP DOWN INTO NORTH DAKOTA. AS SUCH...AFTER 850MB TEMPS WARM UP TO
A CONSENSUS 4-8C AT 12Z THURSDAY AHEAD OF THE FRONT...THEY FALL BACK
DOWN TO 0 TO -4C. THIS COLD ADVECTION MAY BE ENOUGH TO PROVIDE A
LITTLE FALL TO TEMPERATURES IN THE AFTERNOON. REGARDING
TEMPERATURES...LEANED CLOSER TO A BLEND OF GUIDANCE FROM THE
MAJORITY GROUP...YIELDING LOWS IN THE MID 30S TO LOW 40S AND HIGHS
IN THE 50S TO LOWER 60S. WARMEST READINGS ON THURSDAY EXPECTED IN
THE FAR SOUTHEAST WITH THE LONGEST PERIOD AHEAD OF THE FRONT AND
POTENTIAL FOR MOST SUN.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
235 PM CDT MON OCT 8 2012
MAIN FORECAST CONCERN IS ON THE EXPECTED WIDESPREAD RAINFALL
CENTERED AROUND SATURDAY
08.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT
AMONGST EACH OTHER AND PAST RUNS SHOWING A PATTERN CHANGE HERE LATE
THIS WEEK. CURRENT UPPER LOW OFF THE COAST OF CALIFORNIA...WHICH
WILL BE DROPPING INTO THE DESERT SOUTHWEST BY FRIDAY MORNING...
MODELS PROG TO LIFT INTO NEBRASKA AND KANSAS ON SATURDAY. A LOW
PRESSURE SYSTEM DEEPENS AHEAD OF THIS UPPER LOW...RESULTING IN
STRONG LOW LEVEL MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO
NORTHWARD INTO THE FORECAST AREA. SO AFTER WHAT WILL BE A DRY AND
COOL THURSDAY NIGHT AND FRIDAY ASSOCIATED WITH CANADIAN HIGH
PRESSURE MOVING ACROSS...EXPECT WARMING WITH PRECIPITATION
EVENTUALLY SPREADING IN FRIDAY NIGHT AND SATURDAY. SATURDAY STILL
LOOKS TO BE THE BEST DAY FOR PRECIPITATION WITH EXPECTED COMBINATION
OF ISENTROPIC LIFT...UPPER JET FORCING AND DPVA. SOME DIFFERENCES DO
EXIST ON SATURDAY AND PARTICULARLY SATURDAY NIGHT AND SUNDAY
REGARDING THE TRACK OF THE UPPER AND SURFACE LOWS. THE 08.12Z
CANADIAN AND A FEW OF THE GFS ENSEMBLE MEMBERS HOLD THE MAJORITY OF
THE SYSTEM BACK OVER THE CENTRAL PLAINS...WHEREAS MOST OTHER MODELS
CONTINUE THE IDEA OF THE PAST FEW DAYS OF EJECTING IT UP TOWARDS THE
GREAT LAKES. HOWEVER...THERE HAS BEEN A TREND IN THE LATTER GROUP TO
ALSO LIFT THE SYSTEM MORE TO THE NORTHWEST. AS A RESULT...FOR LATE
SATURDAY AND SATURDAY EVENING...OUR WHOLE FORECAST AREA ENDS UP IN
THE WARM SECTOR. ALTHOUGH 0-6KM SHEAR IS PLENTIFUL AHEAD OF THE COLD
FRONT...NO FEAR OF SEVERE CONVECTION AS THE 0-3KM MUCAPE FOR
SATURDAY AND SATURDAY NIGHT IS GENERALLY LESS THAN 500 J/KG. FOR THE
FORECAST...HAVE LEANED TOWARDS THE LATTER GROUP...BUT EITHER
SCENARIO YIELDS WIDESPREAD RAINFALL FOR THE FORECAST AREA SATURDAY
INTO MUCH OF SATURDAY NIGHT. THUNDER CHANCES REMAIN NECESSARY DUE TO
THE EXPECTED MUCAPE. EXACT QPF AMOUNTS UNCERTAIN...ESPECIALLY WITH
THE TREND OF THE SYSTEM NOW MORE THE NORTHWEST WHICH WOULD LIKELY
BE LESS THAN IF THE SYSTEM WAS GOING SLIGHTLY TO OUR SOUTH.
IN THE WAKE OF THE UPPER LOW...FORECAST BECOMES A LITTLE MORE
UNCERTAIN FOR SUNDAY INTO MONDAY. PATTERN FROM THE EAST PACIFIC
ACROSS NORTH AMERICA APPEARS TO HAVE FAST FLOW ASSOCIATED WITH IT.
THERE ARE SUGGESTIONS BY THE 08.12Z GFS AND 08.00Z ECMWF OF A
SHORTWAVE TROUGH COMING OUT OF THE PACIFIC NORTHWEST ON SATURDAY
WHICH DIGS INTO THE CENTRAL PLAINS ON MONDAY. GFS ENSEMBLES SHOW A
LOT OF SPREAD...THOUGH...WITH SOME NOT HAVING THIS TROUGH AT ALL AND
ACTUALLY SHOWING A RIDGE. NEW 08.12Z ECMWF KEEPS THE SHORTWAVE
MOVING EAST WITH HINTS OF RIDGING COMING AT THE FORECAST AREA LATE
MONDAY. AS SUCH...HAVE FOLLOWED A CONSENSUS APPROACH FOR THE SUNDAY
THROUGH MONDAY FORECAST. NET RESULT IS TO HAVE SOME LOW
PRECIPITATION CHANCES ON SUNDAY WITH ANY LINGERING PRECIPITATION
FROM THE UPPER LOW...THEN SOME LOW PRECIPITATION CHANCES ON
MONDAY WITH THE POTENTIAL OF THE SHORTWAVE TROUGH DROPPING IN.
TEMPERATURES AT LEAST LOOK CLOSER TO NORMAL THANKS TO THE PACIFIC
FLOW OF AIR.
&&
.AVIATION...TONIGHT AND TUESDAY
630 PM CDT MON OCT 8 2012
SURFACE TROUGH MOVING THROUGH SOUTH CENTRAL MINNESOTA LATE THIS
EVENING. RATHER TIGHT PRESSURE GRADIENT AHEAD OF IT HAS RESULTED
IN GUSTY WINDS AT THE TAF SITES. THE TROUGH IS EXPECTED TO PUSH
THROUGH THE SITES LATE TONIGHT...WITH THE PRESSURE GRADIENT
WEAKENING EARLY THIS EVENING. THUS EXPECT WINDS TO DIMINISH
THROUGH THE EVENING HOURS. CEILINGS EXPECTED TO REMAIN IN THE VFR
CATEGORY THROUGH TONIGHT...BUT MODELS SUGGEST LOW LEVEL SATURATION
OCCURRING BETWEEN 12Z-15Z AT THE TAF SITES. 08.15Z SREF SHOWING
HIGHER PROBABILITIES OF LESS THAN 3000 FOOT CEILINGS AFTER 12Z
TUESDAY. THUS PER PREVIOUS FORECAST DID MAINTAIN MVFR CEILINGS AT
BOTH SITES AFTER 12Z TUESDAY. FRONTOGENETIC FORCING RESULTING IN
STRONG LIFT WILL ALSO AID IN LOW LEVEL SATURATION WITH LIGHT RAIN
DEVELOPING AFTER 12Z. DEPENDING UPON SPEED OF TROUGH MAY SEE SOME
RISING CEILINGS LATE IN THE TAF PERIOD...POSSIBLE RISING INTO THE
VFR CATEGORY AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
702 PM CDT MON OCT 8 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JLR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
630 PM CDT MON OCT 8 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
235 PM CDT MON OCT 8 2012
MAIN FORECAST CONCERN IS ON RAIN CHANCES FOR TONIGHT AND TUESDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE NORTHEAST PACIFIC AND TROUGHING ACROSS
CENTRAL AND EASTERN CANADA. WITHIN THIS TROUGH...THERE ARE TWO
SHORTWAVE TROUGHS OF NOTE. THE FIRST IS OVER NORTHERN MINNESOTA...
WITH AN ASSOCIATED 998MB SURFACE LOW OVER NORTHWEST MINNESOTA. DPVA
AHEAD OF THE SHORTWAVE IN CONJUNCTION WITH WARM ADVECTION/ISENTROPIC
LIFT HAS SUPPORTED A LARGE AREA OF ALTOSTRATUS ACROSS MINNESOTA INTO
THE NORTHWEST HALF OF WISCONSIN. DRY LOW LEVEL AIR SEEN ON THE 12Z
MPX SOUNDING AS WELL AS SURFACE RELATIVE HUMIDITIES IN THE 25-40
PERCENT RANGE HAS KEPT THE SOUTHERN MINNESOTA DRY DESPITE LIGHT
RETURNS ON RADAR. BREEZY SOUTHWEST WINDS ARE ALSO OCCURRING ACROSS
THE FORECAST AREA AS A RESULT OF A TIGHT PRESSURE GRADIENT. THESE
SOUTHWEST WINDS ARE ADVECTING WARMER AIR INTO THE AREA...NOTED BY
850MB TEMPS PER THE RAP THAT HAVE CLIMBED TO 4-6C AFTER STARTING OFF
AT 1-3C ACCORDING TO 12Z RAOBS. COLD FRONT ASSOCIATED WITH THE LOW
PRESSURE AREA APPROACHING SIOUX FALLS SOUTH DAKOTA. THE NEXT
SHORTWAVE TROUGH OF NOTE...WHICH LOOKS QUITE POTENT IN WATER
VAPOR...IS IN SOUTHERN SASKATCHEWAN. A 100-120 KT JET NEAR 250MB WAS
LOCATED ON THE WEST/SOUTHWEST SIDE OF THIS SHORTWAVE.
TONIGHT AND TUESDAY...THE POTENT SHORTWAVE IN SASKATCHEWAN MODELS
SHOW DROPPING DOWN INTO THE DAKOTAS TONIGHT...THEN INTENSIFYING AND
TURNING NEUTRAL TILT AS IT CROSSES MINNESOTA INTO FAR WESTERN
WISCONSIN DURING THE DAY TUESDAY. AS THIS SHORTWAVE APPROACHES
TONIGHT...IT HELPS TO SLOW DOWN THE CURRENT EASTWARD PROGRESS OF THE
COLD FRONT NEAR SIOUX FALLS. IN FACT...BY 12Z...THE FRONT MAY JUST
BE GETTING INTO SOUTHEAST MN. AS SUCH...A MILD NIGHT COMPARED TO
WHAT HAS BEEN SEEN RECENTLY IS ON TAP TONIGHT...AIDED BY A
CONTINUING SOUTHWEST BREEZE AND PLENTY OF CLOUDS. THEREFORE...STAYED
ON THE WARM SIDE OF GUIDANCE. PRECIPITATION CHANCES TONIGHT ARE VERY
QUESTIONABLE BECAUSE OF THE SLOW FRONTAL PROGRESS. WHEN HEADING INTO
THE COLD SEASON...MOST PRECIPITATION FALLS POST-COLD FRONTAL BECAUSE
OF COLD AIR UNDERCUTTING THE WARM AIR. IN THIS CASE...THE
FRONTOGENESIS FORCING WHICH DOES STRENGTHEN THROUGH THE NIGHT ENDS
UP STAYING MOSTLY WEST OF THE AREA. AS SUCH...HAVE CONFINED THE
PRECIPITATION CHANCES TO MOSTLY LATE TONIGHT AND OVER THE NORTHWEST
1/3 OF THE AREA. IN ADDITION...HAVE KEPT THE CHANCES IN THE 20-40
RANGE AS CONFIDENCE IS LOW IN GETTING THE AIR SATURATED AND THE
FRONT INTO THE AREA. NOW THINGS ARE A LOT DIFFERENT ON TUESDAY. THE
FRONTOGENESIS ZONE ON TUESDAY IS PROGGED TO STRENGTHEN
DRAMATICALLY...CAUSED BY THE APPROACHING SHORTWAVE. CROSS-SECTIONS
SHOW A NICE FRONTOLYSIS/FRONTOGENESIS COUPLET WHICH YIELDS STRONG
UPWARD VERTICAL MOTION. SO ANTICIPATING THAT AS THE SHORTWAVE MOVES
IN AND PUSHES THE FRONT EAST...SHOULD SEE A BAND OF RAIN BEHIND IT.
IN FACT...MOST OF THE AREA LOOKS TO GET RAIN NOW FOR TUESDAY...
THOUGH NORTHWEST SECTIONS SHOULD DRY OUT IN THE AFTERNOON AS THE
FRONTOGENESIS FORCING HEADS EAST. WITH THE FRONT AND RAIN MOVING
THROUGH...A NON-DIURNAL TREND IS REQUIRED. PLUS...850MB TEMPS FALL
FROM 2-6C AT 12Z TO 0 TO -2C AT 00Z. HIGHS WILL TOP OUT IN THE UPPER
40S TO MIDDLE 50S AT BEST...AND FOR SOME LOCATIONS THIS MAY BE A
MORNING HIGH.
TUESDAY NIGHT AND WEDNESDAY...THE FORECAST AREA IS PROGGED TO SIT
UNDER UPPER LEVEL TROUGHING FOR MUCH OF TUESDAY NIGHT...IN THE WAKE
OF THE POTENT SHORTWAVE PUSHING EAST OF THE AREA DURING THE EVENING.
NORTHERLY LOW LEVEL FLOW UNDER THE UPPER TROUGH WILL HELP DRIVE
850MB TEMPS FURTHER DOWN...REACHING -4 TO -7C BY 12Z WEDNESDAY.
ACCOMPANYING THE COLDER AIR SHOULD BE A LOW STRATUS DECK...
PARTICULARLY ACROSS WISCONSIN. SO AFTER PERHAPS A BRIEF PERIOD OF
CLEARING IN THE EVENING IN THE WAKE OF THE PRECIPITATION...EXPECT
CLOUDS TO INCREASE. THE COMBINATION OF THESE CLOUDS AND A DECENT
NORTHERLY BREEZE WILL HELP TO KEEP TEMPERATURES FROM BOTTOMING OUT
TO MUCH. HAVE LEANED TOWARDS THE WARMER SIDE OF GUIDANCE AS A RESULT
WITH LOWS IN THE UPPER 20S TO LOWER 30S. THIS STRATUS DECK WILL
DISSIPATE ON WEDNESDAY AS A SURFACE HIGH PRESSURE RIDGE AXIS SLIDES
EAST ACROSS THE AREA. IN FACT...BY 00Z THURSDAY...STRENGTHENING
SOUTHWEST BREEZES ARE EXPECTED AHEAD OF YET ANOTHER POTENT SHORTWAVE
DROPPING DOWN INTO SOUTH CENTRAL CANADA. THESE BREEZES WILL HELP
ADVECT WARMER AIR INTO THE AREA...WITH 850MB TEMPS CLIMBING TO 0 TO
-3C BY 00Z. PLENTY OF SUN AND DRY AIR SHOULD ALLOW FOR PLENTY OF
MIXING...BUT GIVEN THE COOL 850MB TEMPS...AT BEST HIGHS MAY REACH
THE MID 50S AND THAT IS IN FAR SOUTHWESTERN PORTIONS OF THE FORECAST
AREA WHERE THE WARMEST AIR COMES IN LATE.
WEDNESDAY NIGHT AND THURSDAY...THE NEXT POTENT SHORTWAVE THAT
DROPPED DOWN INTO SOUTH CENTRAL CANADA ON WEDNESDAY IS FORECAST TO
HEAD TO THE EAST...VERSUS DIG DOWN TOWARDS THE FORECAST AREA LIKE
THE PAST COUPLE HAVE DONE. AS SUCH...ALL FORCING AND EXPECTED
PRECIPITATION WITH IT WILL STAY WELL NORTH OF THE FORECAST AREA.
HOWEVER...A COLD FRONT IS STILL SLATED TO COME THROUGH. SOME TIMING
DIFFERENCES ON THE SPEED...WITH THE 08.12Z NAM THE SLOWEST NOT
SHOWING FULL PASSAGE UNTIL THURSDAY EVENING WHILE THE 08.12Z
GFS/ECMWF/CANADIAN/UKMET SUGGESTING MAINLY DURING THURSDAY MORNING.
WILL FOLLOW THE MAJORITY GROUP AT THIS TIME AND CONSIDER THE NAM AN
OUTLIER. NO MATTER WHAT MODEL FOLLOWED...IN THE COLD FRONT
WAKE...YET ANOTHER COLD CANADIAN HIGH PRESSURE AREA IS PROGGED TO
DROP DOWN INTO NORTH DAKOTA. AS SUCH...AFTER 850MB TEMPS WARM UP TO
A CONSENSUS 4-8C AT 12Z THURSDAY AHEAD OF THE FRONT...THEY FALL BACK
DOWN TO 0 TO -4C. THIS COLD ADVECTION MAY BE ENOUGH TO PROVIDE A
LITTLE FALL TO TEMPERATURES IN THE AFTERNOON. REGARDING
TEMPERATURES...LEANED CLOSER TO A BLEND OF GUIDANCE FROM THE
MAJORITY GROUP...YIELDING LOWS IN THE MID 30S TO LOW 40S AND HIGHS
IN THE 50S TO LOWER 60S. WARMEST READINGS ON THURSDAY EXPECTED IN
THE FAR SOUTHEAST WITH THE LONGEST PERIOD AHEAD OF THE FRONT AND
POTENTIAL FOR MOST SUN.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
235 PM CDT MON OCT 8 2012
MAIN FORECAST CONCERN IS ON THE EXPECTED WIDESPREAD RAINFALL
CENTERED AROUND SATURDAY
08.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT
AMONGST EACH OTHER AND PAST RUNS SHOWING A PATTERN CHANGE HERE LATE
THIS WEEK. CURRENT UPPER LOW OFF THE COAST OF CALIFORNIA...WHICH
WILL BE DROPPING INTO THE DESERT SOUTHWEST BY FRIDAY MORNING...
MODELS PROG TO LIFT INTO NEBRASKA AND KANSAS ON SATURDAY. A LOW
PRESSURE SYSTEM DEEPENS AHEAD OF THIS UPPER LOW...RESULTING IN
STRONG LOW LEVEL MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO
NORTHWARD INTO THE FORECAST AREA. SO AFTER WHAT WILL BE A DRY AND
COOL THURSDAY NIGHT AND FRIDAY ASSOCIATED WITH CANADIAN HIGH
PRESSURE MOVING ACROSS...EXPECT WARMING WITH PRECIPITATION
EVENTUALLY SPREADING IN FRIDAY NIGHT AND SATURDAY. SATURDAY STILL
LOOKS TO BE THE BEST DAY FOR PRECIPITATION WITH EXPECTED COMBINATION
OF ISENTROPIC LIFT...UPPER JET FORCING AND DPVA. SOME DIFFERENCES DO
EXIST ON SATURDAY AND PARTICULARLY SATURDAY NIGHT AND SUNDAY
REGARDING THE TRACK OF THE UPPER AND SURFACE LOWS. THE 08.12Z
CANADIAN AND A FEW OF THE GFS ENSEMBLE MEMBERS HOLD THE MAJORITY OF
THE SYSTEM BACK OVER THE CENTRAL PLAINS...WHEREAS MOST OTHER MODELS
CONTINUE THE IDEA OF THE PAST FEW DAYS OF EJECTING IT UP TOWARDS THE
GREAT LAKES. HOWEVER...THERE HAS BEEN A TREND IN THE LATTER GROUP TO
ALSO LIFT THE SYSTEM MORE TO THE NORTHWEST. AS A RESULT...FOR LATE
SATURDAY AND SATURDAY EVENING...OUR WHOLE FORECAST AREA ENDS UP IN
THE WARM SECTOR. ALTHOUGH 0-6KM SHEAR IS PLENTIFUL AHEAD OF THE COLD
FRONT...NO FEAR OF SEVERE CONVECTION AS THE 0-3KM MUCAPE FOR
SATURDAY AND SATURDAY NIGHT IS GENERALLY LESS THAN 500 J/KG. FOR THE
FORECAST...HAVE LEANED TOWARDS THE LATTER GROUP...BUT EITHER
SCENARIO YIELDS WIDESPREAD RAINFALL FOR THE FORECAST AREA SATURDAY
INTO MUCH OF SATURDAY NIGHT. THUNDER CHANCES REMAIN NECESSARY DUE TO
THE EXPECTED MUCAPE. EXACT QPF AMOUNTS UNCERTAIN...ESPECIALLY WITH
THE TREND OF THE SYSTEM NOW MORE THE NORTHWEST WHICH WOULD LIKELY
BE LESS THAN IF THE SYSTEM WAS GOING SLIGHTLY TO OUR SOUTH.
IN THE WAKE OF THE UPPER LOW...FORECAST BECOMES A LITTLE MORE
UNCERTAIN FOR SUNDAY INTO MONDAY. PATTERN FROM THE EAST PACIFIC
ACROSS NORTH AMERICA APPEARS TO HAVE FAST FLOW ASSOCIATED WITH IT.
THERE ARE SUGGESTIONS BY THE 08.12Z GFS AND 08.00Z ECMWF OF A
SHORTWAVE TROUGH COMING OUT OF THE PACIFIC NORTHWEST ON SATURDAY
WHICH DIGS INTO THE CENTRAL PLAINS ON MONDAY. GFS ENSEMBLES SHOW A
LOT OF SPREAD...THOUGH...WITH SOME NOT HAVING THIS TROUGH AT ALL AND
ACTUALLY SHOWING A RIDGE. NEW 08.12Z ECMWF KEEPS THE SHORTWAVE
MOVING EAST WITH HINTS OF RIDGING COMING AT THE FORECAST AREA LATE
MONDAY. AS SUCH...HAVE FOLLOWED A CONSENSUS APPROACH FOR THE SUNDAY
THROUGH MONDAY FORECAST. NET RESULT IS TO HAVE SOME LOW
PRECIPITATION CHANCES ON SUNDAY WITH ANY LINGERING PRECIPITATION
FROM THE UPPER LOW...THEN SOME LOW PRECIPITATION CHANCES ON
MONDAY WITH THE POTENTIAL OF THE SHORTWAVE TROUGH DROPPING IN.
TEMPERATURES AT LEAST LOOK CLOSER TO NORMAL THANKS TO THE PACIFIC
FLOW OF AIR.
&&
.AVIATION...TONIGHT AND TUESDAY
630 PM CDT MON OCT 8 2012
SURFACE TROUGH MOVING THROUGH SOUTH CENTRAL MINNESOTA LATE THIS
EVENING. RATHER TIGHT PRESSURE GRADIENT AHEAD OF IT HAS RESULTED
IN GUSTY WINDS AT THE TAF SITES. THE TROUGH IS EXPECTED TO PUSH
THROUGH THE SITES LATE TONIGHT...WITH THE PRESSURE GRADIENT
WEAKENING EARLY THIS EVENING. THUS EXPECT WINDS TO DIMINISH
THROUGH THE EVENING HOURS. CEILINGS EXPECTED TO REMAIN IN THE VFR
CATEGORY THROUGH TONIGHT...BUT MODELS SUGGEST LOW LEVEL SATURATION
OCCURRING BETWEEN 12Z-15Z AT THE TAF SITES. 08.15Z SREF SHOWING
HIGHER PROBABILITIES OF LESS THAN 3000 FOOT CEILINGS AFTER 12Z
TUESDAY. THUS PER PREVIOUS FORECAST DID MAINTAIN MVFR CEILINGS AT
BOTH SITES AFTER 12Z TUESDAY. FRONTOGENETIC FORCING RESULTING IN
STRONG LIFT WILL ALSO AID IN LOW LEVEL SATURATION WITH LIGHT RAIN
DEVELOPING AFTER 12Z. DEPENDING UPON SPEED OF TROUGH MAY SEE SOME
RISING CEILINGS LATE IN THE TAF PERIOD...POSSIBLE RISING INTO THE
VFR CATEGORY AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
235 PM CDT MON OCT 8 2012
WI...NONE.
MN...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ079-086>088-
094>096.
IA...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JLR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
303 PM CDT SUN OCT 7 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
303 PM CDT SUN OCT 7 2012
MAIN FORECAST CONCERNS ARE ON FIRE WEATHER FOR MONDAY AND
PRECIPITATION CHANCES MONDAY NIGHT INTO TUESDAY.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS LOOKS SIMILAR TO YESTERDAY WITH RIDGING OVER THE
NORTHEAST PACIFIC...AND DEEP TROUGHING OVER CENTRAL AND EASTERN
CANADA EXTENDING SOUTH INTO THE CENTRAL PLAINS AND OHIO VALLEY.
THE MAIN FEATURES OF NOTE ARE ON THE WEST SIDE OF THE
TROUGHING...WHICH INCLUDE A WEAK SHORTWAVE TROUGH ENTERING THE
FORECAST AREA NOW...WITH A STRONGER SHORTWAVE IN CENTRAL
SASKATCHEWAN. ONLY A FEW HIGH CLOUDS WERE ACCOMPANYING THE
SHORTWAVE TROUGH CROSSING THE FORECAST AREA. REGARDING THE
SASKATCHEWAN SHORTWAVE... A LARGE EXPANSE OF MID AND HIGH CLOUDS
ENCOMPASSED MUCH OF SASKATCHEWAN. AT THE SURFACE...PRESSURE
GRADIENT HAS TIGHTENED ACROSS THE NORTHERN PLAINS AND THE FORECAST
AREA...AHEAD OF A 1002MB LOW IN CENTRAL SASKATCHEWAN. THE BREEZY
SOUTHWEST WINDS ARE GRADUALLY WARMING THINGS...WITH RAP 850MB
TEMPS AT MPX NOW AROUND 0C COMPARED TO -5C PER 12Z SOUNDING.
AIRMASS QUITE DRY TOO WITH MPX SOUNDING SHOWING 0.18 INCHES OF
PRECIPITABLE WATER OR 30 PERCENT OF NORMAL.
TONIGHT AND MONDAY...MODELS ARE IN MUCH BETTER AGREEMENT HANDLING
THE SHORTWAVE DROPPING DOWN OUT OF SASKATCHEWAN...TRACKING IT TO
NEAR INTERNATIONAL FALLS MN BY 00Z TUESDAY. CO-LOCATED NEARLY RIGHT
UNDERNEATH IT WILL BE THE SURFACE LOW...PROGGED TO DEEPEN
SLIGHTLY...WITH ITS COLD FRONT APPROACHING MINNEAPOLIS AND SIOUX
CITY IOWA AT 00Z TUESDAY. TIGHT PRESSURE GRADIENT FORECAST TO STAY
PUT OVER THE FORECAST AREA THROUGH MONDAY...EXPECTED TO GET EVEN
STRONGER...AS THE FRONT APPROACHES. NOCTURNAL COOLING MAY ALLOW
WINDS TO DIMINISH SOME TONIGHT...ESPECIALLY AT THE TYPICAL COLD
SPOTS...BUT ANTICIPATING BREEZY CONDITIONS TO QUICKLY DEVELOP MONDAY
MORNING WITH THE ONSET OF DIURNAL HEATING. FORECAST SOUNDINGS SHOW
MIXING ANYWHERE FROM 850MB TO 800MB WHERE A WIND CORE OF 35-40 KT IS
PRESENT. THUS GUSTS UPWARDS OF 30 KT ARE POSSIBLE. REGARDING THE
MIXING...IT IS INTERESTING TO SEE THE DEPTH GIVEN WHAT WILL LIKELY
BE A LOT OF CLOUD COVER. 700MB RH FIELDS FROM THE 07.12Z
GFS/NAM/ECMWF/CANADIAN ALL DEPICT THE CURRENT ALTOSTRATUS ACROSS
SASKATCHEWAN SPREADING ACROSS AT LEAST THE NORTHERN 2/3 OF THE
FORECAST AREA DURING THE DAY MONDAY. IN FACT...THE GFS CONTINUES TO
HINT AT EVEN PRECIPITATION FROM TAYLOR COUNTY NORTHWARD COMING OUT
OF THIS MID CLOUD DECK. GIVEN ALL OTHER MODELS DRY AND THE DEEP
MIXING...WILL KEEP A DRY FORECAST GOING. REGARDING HIGH TEMPERATURES
ON MONDAY...THE SOUTHWEST WINDS WILL HELP PROPEL 850MB TEMPS UP TO
4-6C BY 18Z...ALLOWING MOST LOCATIONS TO TOP OUT IN THE 60S. TAYLOR
COUNTY MAY GET STUCK IN THE 50S...THOUGH...DUE TO THICKER CLOUD
COVER PRESENT MUCH OF THE DAY. COMBINATION OF THE WINDS...
TEMPERATURES...ONGOING DROUGHT AND DRY CONDITIONS LEADING TO FIRE
WEATHER CONCERNS. SEE FIRE WEATHER DISCUSSION BELOW. LOWS TONIGHT
SHOULD MAINLY BE IN THE 30S...KEPT UP BY THE WINDS. SOME CONCERN
ABOUT A FROST/FREEZE IN FAR SOUTHWEST WISCONSIN...BUT TEMPERATURES
MAY END UP RIGHT AROUND 32F AND RELATIVE HUMIDITIES DO NOT GET
HIGH ENOUGH TO SUPPORT FROST FORMATION.
MONDAY NIGHT AND TUESDAY...IMMEDIATELY IN THE WAKE OF THE
SASKATCHEWAN SHORTWAVE...MODELS PROG ANOTHER SHORTWAVE WHICH LOOKS
MORE POTENT DROPPING DOWN INTO THE DAKOTAS MONDAY NIGHT...THEN
ENTERING THE WESTERN PORTION OF THE FORECAST AREA ON TUESDAY. THIS
SHORTWAVE IS CURRENTLY IN THE NORTHWEST TERRITORIES. THE SHORTWAVE
LOOKS TO SLOW DOWN THE COLD FRONTAL PASSAGE INITIALLY...SINCE IT
CAUSES THE UPPER FLOW TO TURN PARALLEL. NOT UNTIL TUESDAY DOES THE
FRONT GET A BETTER PUSH EAST ACROSS THE FORECAST AREA...IN RESPONSE
TO THE SHORTWAVE APPROACHING. THUS...MONDAY NIGHT SHOULD STAY
RELATIVELY MILD COMPARED TO WHAT WE HAVE SEEN WITH LOWS IN THE 40S.
BIGGER ISSUE THOUGH IS IF ANY PRECIPITATION CAN OCCUR. THERE IS SOME
LOW TO MID LEVEL FRONTOGENESIS THAT DEVELOPS IN THE WAKE OF THE COLD
FRONT MONDAY NIGHT. HOWEVER...MODELS ARE PRETTY DRY WITH ONLY HINTS
OF A LITTLE LIGHT QPF BETWEEN 06-12Z TUESDAY IN A NARROW BAND. THIS
IS LIKELY DUE TO A COMBINATION OF THE FORCING NOT THAT STRONG AND
PRECIPITABLE WATER VALUES WHICH ARE JUST CLIMBING TO 0.75 OF AN INCH
AT 12Z. TUESDAY IS A DIFFERENT STORY...WITH THE MORE POTENT
SHORTWAVE APPROACHING. THIS SHORTWAVE ENHANCES THE FRONTOGENESIS
CIRCULATION AND NOW THE HIGHER PRECIPITABLE WATER IS IN PLACE. ALL
MODELS DEVELOP A BAND OF LIGHT TO POSSIBLY EVEN MODERATE RAIN BY THE
AFTERNOON ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA. GIVEN
THE POTENCY OF THE SHORTWAVE...THIS CERTAINLY SEEMS POSSIBLE.
THEREFORE...HAVE RAISED PRECIPITATION CHANCES WITH A MAX OF 60 IN
THE SOUTHEASTERN HALF. WITH PLENTY OF CLOUDS...COLD FRONTAL PASSAGE
AND POTENTIAL FOR PRECIPITATION...STAYED ON THE COOLER OF GUIDANCE
FOR HIGHS.
TUESDAY NIGHT AND WEDNESDAY...THE POTENT SHORTWAVE APPROACHING THE
FORECAST AREA AT 00Z WEDNESDAY LOOKS TO MOVE THROUGH FAIRLY
QUICKLY...PERHAPS REACHING LAKE MICHIGAN BY 06Z. THE ENHANCED
FRONTOGENESIS BAND COULD STILL BE OVER THE SOUTHEASTERN 1/3 OF THE
FORECAST AREA IN THE EVENING...AS SUGGESTED BY THE 07.00Z ECMWF...
SO HAVE MAINTAINED A 20-30 PERCENT CHANCE OF PRECIPITATION. AFTER
THAT...STRONG SUBSIDENCE AND DRYING COMES IN ALOFT...WHICH MAY TRAP
SOME LOW CLOUDS ALONG/EAST OF THE MISSISSIPPI RIVER. SURFACE RIDGE
AXIS STILL WELL TO THE WEST TUESDAY NIGHT...ONLY REACHING WESTERN
MINNESOTA BY 12Z WEDNESDAY...FAVORING TOO THE CLOUDS TO STAY IN
PLACE. COMBINATION OF DAYTIME MIXING AND THE SURFACE RIDGE AXIS
CROSSING THE AREA ON WEDNESDAY WILL HELP TO DISSIPATE THE CLOUDS.
HAVE INCREASED CLOUD COVER BUT MAY NEED FURTHER INCREASES...
PARTICULARLY IN WISCONSIN WHICH IS MORE IN CYCLONIC LOW LEVEL FLOW.
850MB TEMPS DROP QUITE A BIT ON TUESDAY NIGHT...FALLING FROM 0-4C AT
00Z TO -2 TO -4C AT 12Z. HOWEVER...A NORTHERLY BREEZE ON THE EAST
SIDE OF THE RIDGE AXIS PLUS CLOUDS MAY END UP HOLDING TEMPERATURES
UP HIGHER THAN GUIDANCE. AS SUCH...LEANED A LITTLE WARMER THAN WHAT
GUIDANCE SHOWED WITH LOWS MAINLY IN THE LOW 30S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
303 PM CDT SUN OCT 7 2012
07.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT
ON THE PATTERN CHANGE FORECAST THE PAST FEW DAYS. ONE MORE SHORTWAVE
TROUGH IS FORECAST TO DROP DOWN THROUGH THE DEEP TROUGHING...
CROSSING LAKE SUPERIOR ON THURSDAY. THIS SHORTWAVE TROUGH AND
ASSOCIATED COLD FRONT LOOK TO COME THROUGH DRY...WITH YET ANOTHER
CANADIAN HIGH PRESSURE AREA BUILDING IN FOR FRIDAY. AFTER THAT...THE
RIDGING OVER THE NORTHEAST PACIFIC...AS WELL AS AN UPPER LOW
CURRENTLY OFF THE CALIFORNIA COAST...GET PUSHED TO THE EAST. MODEL
HANDLING YESTERDAY WAS PROBLEMATIC WITH THE UPPER LOW...BUT NOW ALL
MODELS ARE IN SYNC IN LIFTING IT OUT OF THE SOUTHWESTERN U.S. INTO
NEBRASKA BY 12Z SATURDAY. STRONG 850MB MOISTURE TRANSPORT IS
INDICATED AHEAD OF THE UPPER LOW...WHICH SHOULD RESULT IN WIDESPREAD
RAIN/SHOWER DEVELOPMENT UPSTREAM TOWARDS THE FORECAST AREA. IN
FACT...THERE ARE EVEN SIGNALS OF A COUPLED UPPER JET STRUCTURE TO
SET UP OVER THE FORECAST AREA. BEST CHANCES OF PRECIPITATION ARE ON
SATURDAY AS THE UPPER LOW AND THE ASSOCIATED LOW PRESSURE SYSTEM
LIFT INTO IOWA. HAVE ALSO INCLUDED A MENTION OF THUNDER ON
SATURDAY...MAINLY SOUTH OF I-90...WHERE 850MB TEMPS ARE CLIMBING
TOWARDS 10-12C AND MUCAPE VALUES TOP OUT BETWEEN 200-500 J/KG.
CHANCES OF PRECIPITATION CONTINUE THROUGH SUNDAY...WITH THOSE ON
SATURDAY NIGHT RELATED TO DEFORMATION ON THE BACK SIDE OF THE
SURFACE LOW PASSING TO OUR SOUTH...THEN WITH A POSSIBLE SHORTWAVE
DROPPING DOWN OUT OF CANADA IN THE WAKE OF THE UPPER LOW.
TEMPERATURES OVERALL THROUGH MUCH OF THE LONG TERM PERIOD EXPECTED
TO STAY BELOW NORMAL...EVEN WITH THAT WARMER AIR COMING UP ON
SATURDAY. THE PROBLEM WITH SATURDAY IS THERE WILL LIKELY BE A LOT OF
CLOUDS AND THE RAIN AROUND. FOLLOWED THE CONSENSUS WHICH RESULTS IN
HIGHS IN THE 50S. COLDEST NIGHT LOOKS TO BE THURSDAY NIGHT AS THAT
CANADIAN HIGH BUILDS ALMOST OVERHEAD BY 12Z FRIDAY. LOWS AT OR BELOW
FREEZING ARE LIKELY.
&&
.AVIATION...THROUGH 18Z MONDAY
1222 PM CDT SUN OCT 7 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. WINDS
WILL BE ON THE INCREASE LATE TONIGHT INTO MONDAY A SURFACE TROUGH
APPROACHES FROM THE DAKOTAS. LOW LEVEL WIND SHEAR IS POSSIBLE LATE
TONIGHT INTO EARLY MONDAY MORNING IF SURFACE WINDS DECOUPLE. AT
THIS TIME IT APPEARS THAT SOUTHWEST WINDS AT THE SURFACE WILL STAY
IN THE 8 TO 13 KT RANGE THROUGH THE NIGHT AT KLSE AND IN THE 10 TO
15 KT RANGE AT KRST. FORECAST SOUNDINGS SHOW SOUTHWEST WINDS
INCREASING TO AROUND 42 KTS AT 1500 FT. WITH SURFACE WINDS STAYING
UP IT APPEARS THAT WE WILL FALL JUST SHORT OF LOW LEVEL WIND
SHEAR CRITERIA SO HAVE NOT INCLUDED IT IN THE TAFS AT THIS TIME. WILL
HAVE TO KEEP A CLOSE EYE ON SURFACE WINDS OVERNIGHT. CLOUDS WILL
INCREASE LATE TONIGHT INTO MONDAY MORNING...AND BY MONDAY MORNING
A BROKEN MID CLOUD DECK WILL BE IN PLACE WITH CLOUD BASES AROUND
9KFT. LOOK FOR THE BREEZY SOUTHWEST WINDS TO CONTINUE MONDAY WITH
SPEED OF 15 TO 20 KTS...GUSTING INTO THE 25 TO 30 KT RANGE AT
TIMES.
&&
.FIRE WEATHER...MONDAY
327 PM CDT SUN OCT 7 2012
A BREEZY SOUTH WIND TONIGHT...ESPECIALLY WEST OF THE MISSISSIPPI
RIVER...WILL HELP PREVENT FULL RELATIVE HUMIDITY RECOVERY TONIGHT
GIVEN DEWPOINTS RIGHT NOW IN THE TEENS. MAXIMUM RELATIVE HUMDITY
VALUES ARE ONLY EXPECTED TO TOP OUT BETWEEN 60-70 PERCENT AT MOST.
THE BREEZY SOUTH TO SOUTHWEST WINDS ARE EXPECTED TO PERSIST INTO
THE DAY MONDAY AS LOW PRESSURE DROPS INTO NORTHERN MINNESOTA.
SUSTAINED SPEEDS OF 15 TO 25 MPH ARE LIKELY WITH GUSTS OF 30 TO 35
MPH. PLENTY OF CLOUDS ASSOCIATED WITH THE LOW PRESSURE AREA SHOULD
OVERSPREAD THE AREA...ESPECIALLY ALONG AND NORTH OF I-90. THIS
RESULTS IN SOME ISSUES...PRIMARILY WITH FINE FUELS. HOWEVER...WITH
TEMPERATURES WARMING UP INTO THE 60S AND RELATIVE HUMIDITIES
DROPPING INTO THE 20-25 PERCENT RANGE WEST OF THE MISSISSIPPI
RIVER...VERY CONCERNED ABOUT FIRES. THE ONGOING MODERATE TO
EXTREME DROUGHT PLUS MOST OF THE REGION EXPERIENCING A FREEZE ALSO
CREATES EXTRA CONCERN FOR FIRES. AFTER COORDINATION WITH MINNESOTA
AND IOWA FIRE WEATHER OFFICIALS...HAVE ISSUED A FIRE WEATHER WATCH
FOR LOCATIONS WEST OF THE MISSISSIPPI RIVER. EAST OF THE
MISSISSIPPI RIVER...MINIMUM RELATIVE HUMIDITIES ONLY DROP TO 25-30
PERCENT. WINDS ARE SLIGHTLY LIGHTER AND TEMPERATURES ARE COOLER.
AFTER COORDINATION WITH WISCONSIN FIRE WEATHER OFFICIALS...HAVE
DECLINED TO ISSUE ANY FIRE WEATHER WATCH EAST OF THE MISSISSIPPI
RIVER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
303 PM CDT SUN OCT 7 2012
WI...NONE.
MN...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR MNZ079-086>088-094>096.
IA...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1152 PM CDT SAT OCT 6 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
252 PM CDT SAT OCT 6 2012
MAIN FORECAST CONCERNS ARE ON FREEZE POTENTIAL TONIGHT...NEAR
CRITICAL FIRE WEATHER CONDITIONS SUNDAY AND MONDAY...AND FINALLY
PRECIPITATION CHANCES FOR MONDAY NIGHT AND TUESDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED RIDGING OVER THE NORTHEAST PACIFIC AND ALONG THE
WEST COAST OF THE U.S....WHILE DEEP TROUGHING WAS PRESENT OVER
CENTRAL AND EASTERN CANADA SOUTHWARD INTO THE CENTRAL PLAINS AND
OHIO RIVER VALLEY. WITHIN THE TROUGHING...A SHORTWAVE TROUGH
EXTENDED EAST-WEST ACROSS THE FORECAST AREA AND WEST TOWARDS
NEBRASKA. UNDERNEATH THIS SHORTWAVE TROUGH WAS AN AREA OF BROKEN
STRATUS ACROSS THE FORECAST AREA TO NEAR DULUTH. MUCH OF THIS
STRATUS WAS SITUATED AT 750MB OR BELOW PER 12Z SOUNDINGS FROM
INL...MPX AND GRB. THE REASON THE DECK IS NOT A SOLID OVERCAST IS
THAT THE SOUNDINGS DO NOT SHOW COMPLETE SATURATION. IN FACT...SOME
OF THE STRATUS FORMATION HAS BEEN DUE TO DAYTIME HEATING...NOTED
BY HOLES THAT FILLED IN DURING THE MORNING. FARTHER TO THE
NORTHWEST ON WATER VAPOR...A SHORTWAVE TROUGH WAS EVIDENT IN
SOUTHERN SASKATCHEWAN DROPPING DOWN THE EAST SIDE OF THE NORTHEAST
PACIFIC RIDGE. LACK OF LOW LEVEL MOISTURE SEEN ON THE 12Z THE PAS
MANITOBA SOUNDING HAS RESULTED IN THE SHORTWAVE JUST PRODUCING A
BAND OF MID AND HIGH CLOUDS. AT THE SURFACE...HIGH PRESSURE WAS
SITUATED OVER THE CENTRAL PLAINS WITH A RIDGE AXIS EXTENDING
NORTHEAST INTO NORTHERN MINNESOTA. 850MB TEMPS CHILLY OVER THE
FORECAST AREA...BETWEEN -5 AND -7C PER 12Z RAOBS...OR 2 STANDARD
DEVIATIONS BELOW NORMAL.
TONIGHT AND SUNDAY...SHORTWAVE TROUGH OVER SOUTHERN SASKATCHEWAN IS
PROGGED TO KEEP DROPPING SOUTHEAST THROUGH THE DEEP UPPER TROUGH...
CROSSING THE FORECAST AREA SUNDAY AFTERNOON. THIS TROUGH WILL DO A
COUPLE OF THINGS. FIRST...THE SURFACE RIDGE AXIS OVER MINNESOTA
WILL GET PUSHED DOWN OVER THE FORECAST AREA TONIGHT. AS THE RIDGE
AXIS AND THE DRY AIR ASSOCIATED WITH IT MOVE IN...SKIES WILL
CLEAR. WINDS SHOULD DECOUPLE AS WELL...EXCLUDING THE HIGHER
TERRAIN OF SOUTHEAST MINNESOTA. GIVEN THE COOL DAY TODAY...THE
SETUP CERTAINLY FAVORS LOWS DROPPING INTO THE 20S AS HAS BEEN
FORECAST THE PAST FEW DAYS. SOME OF THE TYPICAL COLD SPOTS IN
WISCONSIN COULD EVEN HIT THE UPPER TEENS. FREEZE WARNINGS
THEREFORE STILL LOOK GOOD WITH THIS LIKELY BEING THE END OF THE
GROWING SEASON. THE SECOND THING THE SHORTWAVE TROUGH WILL DO IS
TO SPREAD THE CIRRUS AND SOME MID CLOUDS SEEN UP IN SOUTH CENTRAL
CANADA ACROSS THE FORECAST AREA. REGARDING TEMPERATURES...
DOWNSLOPING OF AIR OFF THE ROCKIES AHEAD OF THE SHORTWAVE TROUGH
WILL ALLOW A PLUME OF WARMER 925-850MB AIR TO ADVECT INTO THE
FORECAST AREA. BY 18Z... 925MB AND 850MB TEMPS RISE TO 2-4C AND -3
TO -5C RESPECTIVELY. COMBINE THESE WITH AN INCREASING SOUTHWEST
WIND AS THE SURFACE RIDGE DROPS SOUTH AND HIGHS SHOULD BE ABLE TO
REACH INTO THE LOW TO MID 50S. DRY DEWPOINTS IN THE TEENS WILL
HELP RELATIVE HUMIDITIES PLUMMET INTO THE 20-30 PERCENT
RANGE...RAISING SOME FIRE WEATHER CONCERNS. THESE ARE NOTED IN THE
FIRE WEATHER DISCUSSION BELOW.
SUNDAY NIGHT AND MONDAY...ATTENTION TURNS TO A SHORTWAVE CURRENTLY
WELL UP TO THE NORTHWEST...NEAR THE NORTHWEST CORNER OF THE
NORTHWEST TERRITORIES. MODELS HAVE BEEN VERY CONSISTENT OF DROPPING
THIS SHORTWAVE INTO THE DEEP TROUGH...REACHING SOUTHERN PORTIONS OF
SASKATCHEWAN AND MANITOBA BY 12Z MONDAY. AS THE SHORTWAVE DROPS
SOUTH...A DEEPENING SURFACE LOW ACCOMPANIES IT...WHICH SHOULD REACH
FAR SOUTHERN MANITOBA BY 12Z MONDAY. THIS DEEPENING LOW WILL HELP TO
INCREASE THE SOUTHWEST WINDS EVEN MORE OVER THE FORECAST AREA...AND
ALSO ENHANCE THE DOWNSLOPE EFFECT OFF THE ROCKIES. AS SUCH...925 AND
850MB TEMPS CLIMB TO 6C AND 4C RESPECTIVELY AT 12Z MONDAY. THIS WARM
ADVECTION IS LIKELY TO RESULT AN INCREASE OF MID AND HIGH CLOUDS...
ESPECIALLY AFTER MIDNIGHT SUNDAY NIGHT AND HEADING INTO THE DAY
MONDAY. THESE CLOUDS COMBINED WITH THE WINDS WILL HELP PRODUCE A
MUCH WARMER NIGHT...ALBEIT STILL BELOW NORMAL...MAINLY IN THE 30S.
AFTER 12Z MONDAY...MODELS DIFFER A BIT ON THE TRACK...DEPTH AND
SPEED OF THE SHORTWAVE TROUGH AND SURFACE LOW. OVERALL...THOUGH...
THE GENERAL THEME IS FOR THE SHORTWAVE AND SURFACE LOW TO HEAD
EAST...LIKELY ALONG THE ONTARIO/MN BORDER. COLD FRONT ASSOCIATED
WITH THE LOW STAYS TO OUR WEST...ONLY REACHING ALBERTA LEA BY 00Z.
925MB AND 850MB TEMPS CONTINUE TO WARM AHEAD OF THIS FRONT...TOPPING
OUT AT 12-14C AND 6-8C RESPECTIVELY. WITH A TIGHT PRESSURE GRADIENT
AND MIXING RESULTING IN BREEZY SOUTHWEST WINDS...ALONG WITH DRY LOW
LEVEL AIR...WE SHOULD BE ABLE TO MIX TO NEAR 850MB. ONLY CAVEAT IS
THE MID/HIGH CLOUDS...WHICH LOOK TO INCREASE AND THICKEN THROUGH THE
DAY. ANY PRECIPITATION WITH THESE CLOUDS SHOULD STAY NORTH OF THE
FORECAST AREA PER MODEL CONSENSUS. HIGHS IN THE 60S STILL ARE
REASONABLE...PERHAPS GETTING CLOSE TO 70 WEST OF THE MISSISSIPPI
RIVER. FIRE WEATHER CONCERNS EXIST AGAIN WITH THE BREEZY SOUTHWEST
WINDS...TEMPERATURES AND LOW RELATIVE HUMIDITIES. SEE FIRE WEATHER
DISCUSSION BELOW.
MONDAY NIGHT AND TUESDAY...MODELS SHOW YET ANOTHER FAIRLY STRONG
SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE NORTHEAST PACIFIC
RIDGE...DIGGING INTO NORTH DAKOTA BY 12Z TUESDAY AND THEN INTO
SOUTHERN MINNESOTA BY 00Z WEDNESDAY. THIS SHORTWAVE SHOULD HELP TO
ENHANCE LIFT IN THE WAKE OF THE COLD FRONT...ON TOP OF THE
POST-FRONTAL MID LEVEL FRONTOGENESIS THAT WILL ALREADY EXIST. SO
ONCE THE COLD FRONT MOVES EAST THROUGH THE FORECAST AREA...WHICH
GRADUALLY OCCURS DURING THIS PERIOD UNTIL THIS SHORTWAVE CAN CATCH
UP...ANTICIPATE A BAND OF RAIN TO DEVELOP. THIS SIGNAL OF THE BAND
OF RAIN CONTINUES TO GET STRONGER...WITH THE 06.12Z GFS...NAM...
UKMET...CANADIAN AND ECMWF ALL DEPICTING IT. AS SUCH...HAVE RAISED
PRECIPITATION CHANCES UP TO AROUND 40. FURTHER INCREASES WILL LIKELY
BE NEEDED IF THIS SIGNAL PERSISTS. PRECIPITABLE WATER VALUES ARE
ONLY AROUND 0.75 OF AN INCH...SO MOISTURE IS NOT THAT GREAT...BUT
THE FORCING SHOULD BE ABLE TO SQUEEZE OUT SOME LIGHT PRECIPITATION.
WITH PLENTY OF CLOUDS MONDAY NIGHT AND THE SLOW COLD FRONTAL
PASSAGE...LOWS IN THE 40S SUGGESTED BY MAV/MET GUIDANCE SEEM
REASONABLE. 850MB TEMPS DO GRADUALLY FALL DURING THE DAY
TUESDAY...BOTTOMING OUT AROUND 0C BY 00Z. NEVERTHELESS...HIGHS
SHOULD BE ABLE TO TOP OUT IN THE 50S...COOLEST IN THE NORTHWEST
WHICH ENDS UP MOSTLY BEHIND THE FRONT FOR THE ENTIRE DAY.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
252 PM CDT SAT OCT 6 2012
GOOD MODEL AGREEMENT EXISTS BETWEEN THE 06.12Z ECMWF/GFS/CANADIAN
AND GFS ENSEMBLES ABOUT A PATTERN SHIFT OCCURRING DURING THE LONG
TERM FORECAST...WITH THE CURRENT DEEP TROUGH LIFTING OUT ON FRIDAY.
WE STILL HAVE ONE MORE POTENT SHORTWAVE TO DEAL WITH DROPPING THE
TROUGH PRIOR TO LIFT-OUT...PROGGED TO CROSS LAKE SUPERIOR LATE
THURSDAY. AFTER FRIDAY...MODELS SHOW AN UPPER LOW...CURRENTLY JUST
OFF THE COAST OF CALIFORNIA...LIFTING OUT OF THE SOUTHWESTERN U.S..
EXACTLY HOW FAST THIS EJECTION OCCURS THE MODELS ARE ALL OVER THE
PLACE...WITH THE LATEST 06.12Z GFS THE FASTEST AMONGST ALL MODELS
AND PAST 1-2 DAYS OF RUNS OF THE MODEL. THE GFS HAS THIS DEEP LOW
LIFTING UP INTO SOUTHERN MINNESOTA BY 00Z SUNDAY. EJECTING UPPER
LOWS OUT OF THE SOUTHWESTERN U.S. ARE ALWAYS PROBLEMATIC FOR
MODELS...SINCE THEY HINGE ON UPPER TROUGHS CROSSING THE PACIFIC.
THEREFORE...HAVE LOW CONFIDENCE ON ANY SOLUTION AT THIS POINT...
THOUGH IT WOULD NOT BE SURPRISING IF A SLOWER IDEA ENDS UP PANNING
OUT PER MODEL BIASES.
IN THE WAKE OF TUESDAYS SHORTWAVE...A RIDGE OF HIGH PRESSURE IS
FORECAST TO BUILD IN FOR WEDNESDAY. ANOTHER SHOT OF COOL AIR COMES
WITH THIS RIDGE WITH 850MB TEMPS FALLING TO AROUND -4C. THUS...
TUESDAY NIGHT AND WEDNESDAY WILL BE COOL...BUT NOT NEARLY AS COLD AS
TODAY OR TONIGHT. COULD BE SOME LINGERING PRECIP TUESDAY EVENING IN
THE SOUTHEASTERN THIRD OF THE AREA...ASSOCIATED WITH TUESDAYS
SHORTWAVE...OTHERWISE EXPECT DRY CONDITIONS. WITH THE THURSDAY
SHORTWAVE DROPPING DOWN INTO LAKE SUPERIOR...WE GET ANOTHER COLD
FRONT TO MOVE THROUGH THE FORECAST AREA. DUE TO LIMITED SPACING
BETWEEN THE CANADIAN RIDGE OF HIGH PRESSURE AND THIS FRONT...NOT
ANTICIPATING ANY POST-FRONTAL PRECIPITATION. AHEAD OF THE FRONT...A
SURGE OF 4-6C 850MB AIR IS PROGGED TO COME INTO THE AREA ON STRONG
SOUTHWEST WINDS. SO WE COULD HAVE ANOTHER NEAR CRITICAL FIRE WEATHER
DAY...PARTICULARLY SOUTH OF I-90. ANOTHER COOLER HIGH PRESSURE AREA
IS SLATED TO DROP DOWN INTO OUR REGION FOR FRIDAY...WITH 850MB TEMPS
DROPPING BACK TO AROUND -4C AT 12Z. FOR FRIDAY NIGHT AND SATURDAY...
HAVE FOLLOWED THE CONSENSUS APPROACH AND SPREADING CHANCES OF
PRECIPITATION INTO THE AREA FROM THE SOUTHWEST. THESE ARE ALL DUE TO
WARM...MOIST AIR ADVECTION OUT OF THE GULF OF MEXICO COMING INTO THE
COLDER AIRMASS SITUATED OVER THE FORECAST AREA. MORE REFINEMENT OF
THESE CHANCES WILL COME DURING THE NEXT SEVERAL DAYS AS TIMING OF
THE UPPER LOW EJECTION BECOMES MORE CERTAIN. SHOULD SEE A GRADUAL
WARM UP IN TEMPERATURES TOO WITH THE WARMER AIR ADVECTING INTO THE
AREA. HIGHS BY SATURDAY STILL LOOK BELOW NORMAL BUT ONLY 5 OR SO
DEGREES...NOT LIKE THE 15-20 AS OF LATE.
&&
.AVIATION...THROUGH 06Z MONDAY
1151 PM CDT SAT OCT 6 2012
INFRARED SATELLITE IMAGERY SHOWS BACK EDGE OF STRATUS DECK FROM
NORTHWEST WISCONSIN TO NEAR KAEL. THE BACK EDGE HAS BEEN SLOWLY
WORKING ITS WAY SOUTHEAST AND MODELS CONSISTENT IN SHOWING THIS
BACK EDGE WILL MAKE IT TO KRST AROUND 07Z AND KLSE BETWEEN 08Z-
09Z. UNTIL THEN CEILINGS WILL RANGE FROM 050-060K FEET. AFTER THAT
JUST SOME HIGH CLOUDS ARE EXPECTED WITH VFR CONDITIONS THROUGH THE
REMAINDER OF THE TAF PERIOD.
&&
.FIRE WEATHER...SUNDAY INTO MONDAY
252 PM CDT SAT OCT 6 2012
NEAR CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE BOTH SUNDAY AND
MONDAY. SETTING THE STAGE FOR THESE CONDITIONS IS THE MODERATE TO
EXTREME DROUGHT CONDITIONS IN PLACE ACROSS THE AREA...ALONG WITH A
KILLING FREEZE EXPECTED TONIGHT.
FOR SUNDAY...SOUTHWEST WINDS ARE EXPECTED TO INCREASE IN THE WAKE OF
A RIDGE OF HIGH PRESSURE DROPPING SOUTH ACROSS THE AREA TONIGHT.
THESE WINDS SHOULD BE SUSTAINED IN THE 10-15 MPH RANGE WITH GUSTS OF
12-22 MPH...STRONGEST ACROSS SOUTHEAST MINNESOTA. DEWPOINTS ARE
LIKELY TO STILL BE LOW...THANKS TO MIXING OF DRY AIR ALOFT AND THE
RECENT COLD NIGHT. HOWEVER...LINGERING COLD AIR THAT ONLY SLOWLY
MODIFIES WILL ONLY ALLOW HIGH TEMPERATURES TO TOP OUT IN THE LOW TO
MID 50S. THESE TEMPERATURES COMBINED WITH THE DEWPOINTS SHOULD
PRODUCE MINIMUM RELATIVE HUMIDITIES IN THE 20-30 PERCENT RANGE...
LOWEST SOUTH AND WEST OF I-94. THEREFORE...THE MAIN LIMITING FACTORS
FOR RED FLAG CONDITIONS WOULD BE THE TEMPERATURES AND WINDS.
FOR MONDAY...A STRENGTHENING LOW PRESSURE SYSTEM DROPPING SOUTH OUT
OF CENTRAL CANADA INTO NORTHERN MINNESOTA WILL RESULT IN A TIGHTER
PRESSURE GRADIENT ACROSS THE AREA. AS SUCH...STRONGER WINDS ARE
ANTICIPATED...IN THE 15-25 MPH RANGE WITH GUSTS OF 20-35 MPH.
HIGHEST WINDS ARE LIKELY WEST OF THE MISSISSIPPI RIVER. THESE WINDS
SHOULD BRING UP A LITTLE MORE MOISTURE...BUT HIGH TEMPERATURES WILL
MOSTLY COUNTERACT IT BY JUMPING INTO THE 60S. THEREFORE...MINIMUM
RELATIVE HUMIDITIES ARE ONLY SLIGHTLY HIGHER...BETWEEN 25-35
PERCENT...LOWEST ALONG/WEST OF THE MISSISSIPPI RIVER. GIVEN THE
SLIGHTLY HIGHER MINIMUM RELATIVE HUMIDITIES...TEMPERATURES STILL
SLIGHTLY COOL AND ESPECIALLY POTENTIAL FOR A LOT OF CLOUDS...
CONDITIONS AGAIN JUST LOOK NEAR CRITICAL. THE CLOUDS COULD BE
QUITE PROBLEMATIC BY KEEPING RELATIVE HUMIDITIES HIGHER THAN
EXPECTED.
PER COORDINATION WITH AREA FIRE WEATHER AGENCIES...HAVE HELD OFF
ON ANY FIRE WEATHER WATCHES AT THIS TIME.
LOOKING AHEAD...ANOTHER NEAR CRITICAL FIRE WEATHER DAY COULD OCCUR
SOUTH OF I-90 ON THURSDAY...AHEAD OF A CANADIAN COLD FRONT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
252 PM CDT SAT OCT 6 2012
WI...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR WIZ032-033-041-
053>055-061.
MN...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR MNZ079-088-096.
IA...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS NEW YORK NY
150 AM EDT TUE OCT 9 2012
.SYNOPSIS...
LOW PRESSURE FORMING ALONG THE MID ATLANTIC COAST OVERNIGHT
WILL SLOWLY TRACK NORTHEAST...PASSING EAST OF THE TRI-STATE AREA
TUESDAY EVENING. HIGH PRESSURE THEN BRIEFLY BUILDS BACK IN BEHIND
THE LOW TUESDAY NIGHT. A COLD FRONT MOVES THROUGH WEDNESDAY
AFTERNOON AND EVENING...WITH HIGH PRESSURE BUILDING IN ON
THURSDAY. ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY...FOLLOWED BY
HIGH PRESSURE ON SATURDAY. A WARM FRONT WILL THEN PASS BY ON
SUNDAY...FOLLOWED BY A COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WITH THE DRY AIR REMAINING IN THE AREA HAVE LOWERED POPS UNTIL
LATE TONIGHT WHEN SHORTWAVE PASSES ACROSS THE EASTERN ZONES.
00Z KOKX SHOWS A STRONG DRY LAYER BETWEEN 975-725 HPA AND THE 00Z
KALY SOUND FROM THE SURFACE-575 HPA. THIS GOES ALONG WAY TO
EXPLAINING WHY ANY MEASURABLE RAINFALL HAS BASICALLY REMAINED
OFFSHORE SO FAR THIS EVENING. THE HRRR AND RUC ARE HANDLING THE
CURRENT SITUATION THE BEST...SO HAVE USED TO UPDATE THE FORECAST
FOR OVERNIGHT...SIGNIFICANTLY LOWERING POPS...ESPECIALLY ACROSS
THE NORTHERN INTERIOR AND NW 1/3 OF THE CWA.
LOOKING FURTHER AT THE NAM - GIVEN THE VORTICITY MINIMA IT
FORECASTS AT 700 HPA OVER THE AREA OVERNIGHT - IT IS SURPRISING
THAT IT IS FORECASTING AS MUCH RAIN AS IT DOES. TYPICALLY WITH
THESE FEATURES AT 700 HPA...IT GOES WITH MINIMAL PRECIPITATION AND
ENDS UP BEING CORRECT. SO THE LOWER POPS ARE ALSO CONSISTENT WITH
THE NAM 700 HPA VORTICITY FIELDS.
STILL LOOKS LIKE THE TWIN FORKS COULD GET SOME LIGHT-MODERATE RAIN
LATE - OTHERWISE AT MOST A TENTH OF AN INCH - WITH MOST AREAS
CLOSER TO 0.01 INCHES.
TEMPERATURE FORECAST ON TRACK BASED ON MAV/MET BLEND WITH NEAR
NORMAL LOWS EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
RAIN WILL BE LIKELY DURING THE MORNING HOURS...ESPECIALLY ALONG THE
COAST. THERE WILL BE PLENTY OF LOW-LEVEL MOISTURE IN PLACE WITH A
LOW-LEVEL NE FLOW AND A SW FLOW ALOFT. CONDITIONS WILL DRY OUT
FROM WEST TO EAST DURING THE AFTERNOON HOURS AS THE LOW PASSES TO
THE E AND THEN NE BY EVE. HIGHS WILL BE AROUND 60...WHICH IS
SEVERAL DEGREES BELOW NORMAL.
FOR TUE NIGHT....WITH WEAK LOW-LEVEL WARM ADVECTION...STRATUS
WILL REMAIN ACROSS THE ENTIRE AREA. THERE MAY EVEN BE A LITTLE
DRIZZLE AND/OR LIGHT RAIN DEVELOPING OVERNIGHT WITH AN E/SE
FLOW...ESPECIALLY ACROSS THE HILLS NORTH AND WEST OF NYC. LOWS
WILL ONCE AGAIN BE IN THE MID 40S TO AROUND 50.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE LONGWAVE PATTERN DURING THE LONG TERM PERIOD IS FORECAST TO BE
PROGRESSIVE WITH A LACK OF DEEP AMPLIFICATION. IN
SHORT...RELATIVELY QUICK MOVING SURFACE FEATURES PASS THROUGH THE
FORECAST AREA.
ON WEDNESDAY...A PRE-FRONTAL SURFACE TROUGH MOVES THROUGH. IT LOOKS
LIKE THERE WILL BE DEEP ENOUGH MOISTURE TO WARRANT SLIGHT CHANCE
POPS. BY THE TIME THE TRAILING COLD FRONT ARRIVES LATE IN THE DAY
INTO THE EVENING HOURS....MODELS SHOW DRYING OF THE COLUMN. WILL
THEREFORE CARRY ONLY SLIGHT CHANCE POPS FOR THIS PERIOD. LEANED A
LITTLE MORE TOWARDS THE COOLER NAM MOS DUE TO THE ANTICIPATED CLOUD
COVER...HOWEVER...HIGH TEMPERATURES NEAR NORMAL.
HIGH PRESSURE BUILDS IN ON THURSDAY BEHIND THE COLD FRONT. BUT
BECAUSE OF THE PROGRESSIVE FLOW...RISING HEIGHTS AND SOME AIR MASS
MODIFICATION/MODERATION IS FORECAST BY LATE IN THE DAY. AFTERNOON
HIGHS ARE NOT EXPECTED TO BE SIGNIFICANTLY COOLER...BUT STILL
FALLING BELOW NORMAL LEVELS.
THE NEXT COLD FRONT PASSAGE IS EXPECTED ON FRIDAY. MODELS SHOWING
ONLY LIGHT QPF OUTPUT...SO WON`T BUMP UP POPS JUST YET FROM THE
CURRENT FORECAST OF SLIGHT CHANCE.
HIGH PRESSURE RETURNS ON SATURDAY. THE ORIGIN OF THIS AIRMASS WILL
BE SOMEWHAT MORE DIRECT FROM CANADA WITH LESS TIME TO MODIFY.
THEREFORE EXPECTING TEMPERATURES COOLER THAN THOSE USHERED IN BY
THE HIGH PRESSURE SYSTEM ON THURSDAY.
WITH THE CENTER OF THE HIGH OFFSHORE ON SUNDAY...A RETURN SOUTHERLY
FLOW AND WARM FRONT ENTER THE REGION. MODELS HAVE BEEN TRENDING
FARTHER NORTH REGARDING THE COVERAGE OF QPF ASSOCIATED WITH THE WARM
FRONT. WILL KEEP IN A SLIGHT CHANCE OF SHOWERS NORTH OF THE CITY
LATE SATURDAY INTO SUNDAY MORNING...BUT IT IS LOOKING MORE LIKE A
COMPLETELY DRY UPCOMING WEEKEND ACROSS THE AREA. A TRAILING COLD
FRONT DROPS DOWN FROM THE NORTH ON MONDAY. WITH THE TIMING OF ITS
PASSAGE SOMEWHAT UNCERTAIN...WILL GO WITH SLIGHT CHANCE POPS SUNDAY
NIGHT THROUGH MONDAY NIGHT...BUT MOST OF THE TIME SHOULD BE DRY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE PASSES TO THE EAST TODAY. MAINLY VFR CONDITIONS THE
REST OF TONIGHT...WITH POSSIBLE MVFR CONDITIONS DURING THE DAY
INTO THE COMING NIGHT.
FIRST ROUND OF PCPN NOW PUSHING OFF TO THE EAST. ANOTHER ROUND OF
LIGHT RAIN POSSIBLE BETWEEN 08Z AND 12Z...WITH SOME LINGERING
SHOWERS THROUGH MID MORNING. A PERIOD OF DRY CONDITIONS THEN FOR
THE AFTERNOON WITH HIGH PRESSURE BUILDING BACK IN OVER THE AREA.
VFR CIGS TO START...BUT SHOULD SEE LOWERING OF CIGS TO SUB VFR WITH
THE NEXT ROUND OF PCPN. OVC CONDITIONS THROUGH THE DAY...WITH MOD
CONFIDENCE OF A PERIOD THIS AFTN OF CIGS IMPROVING TO
VFR...RETURNING TO THE LOWER LEVELS AFTER 03Z TONIGHT.
WINDS GENERALLY NE 5-10 KTS...INCREASING TO AROUND 10 KTS DURING
THE DAY AS THE LOW NEARS JUST TO THE EAST.
OUTLOOK FOR 06Z TUESDAY THROUGH SATURDAY...
.TUESDAY NIGHT...MVFR WITH SCT SHOWERS POSSIBLE AFTER 06Z.
.WEDNESDAY...MVFR CONDS POSSIBLE IN -SHRA WITH COLD FRONT
PASSAGE.
.THURSDAY-SATURDAY...VFR.
&&
.MARINE...
MINOR ADJUSTMENTS MADE TO REFLECT LATEST TRENDS IN OBSERVATIONS AND
GUIDANCE. APPEARS WINDS/SEAS WILL REMAIN BENIGN INTO THE OVERNIGHT
HOURS.
A SCA HAS BEEN HOISTED FOR THE OCEAN WATERS TUE-WED MORNING. A
STRENGTHENING NE FLOW AHEAD OF LOW PRESSURE TRACKING NE FROM THE
MID ATLANTIC COAST WILL PRODUCE MARGINAL WIND GUSTS AND SEAS RIGHT
AROUND 5 FT. CONDITIONS WILL BRIEFLY IMPROVE TUE NIGHT AS THE LOW
PASSES TO THE NORTH AND EAST OF THE WATERS. THE REMAINDER OF THE
WATERS SHOULD EXPERIENCE SUB-SCA CONDITIONS TONIGHT-TUESDAY NIGHT.
LOOKS LIKE SUB SCA CONDITIONS SHOULD CONTINUE THROUGH WEDNESDAY
AFTERNOON...BUT WITH A COLD FRONT MOVING THROUGH IN THE
EVENING...WINDS AND SEAS PICK UP...AND MOST IF NOT ALL OF THE AREA
WATERS STAND A GOOD CHANCE OF SCA CONDITIONS. WINDS AND SEAS
SUBSIDE THROUGH THURSDAY WITH HIGH PRESSURE AND A WEAK PRESSURE
GRADIENT IN CONTROL...SO BY LATE IN THE DAY...ALL WATERS ARE
EXPECTED TO HAVE SUB SCA CONDITIONS. ANOTHER COLD FRONT APPROACHES
BEFORE MOVING THROUGH DURING FRIDAY. SCA CONDITIONS PROBABLE ON
SOME OF THE WATERS DURING THIS PERIOD. HIGH PRESSURE WITH A WEAK
PRESSURE RESTORES TRANQUIL CONDITIONS AGAIN ON SATURDAY.
&&
.HYDROLOGY...
RAINFALL FROM LATE THIS AFTERNOON THROUGH TUESDAY MORNING WILL
TOTAL FROM AROUND A FEW HUNDREDTHS OF OF AN INCH ACROSS THE LOWER
HUDSON VALLEY INTO PORTIONS OF NORTHEASTERN NEW JERSEY TO AROUND A
QUARTER TO ONE THIRD OF ACROSS EASTERN LONG ISLAND. THE RAIN WILL
BE MAINLY LIGHT. NO FLOODING IS EXPECTED.
NO SIGNIFICANT RAINFALL EXPECTED MID WEEK THROUGH THE WEEKEND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 AM EDT
WEDNESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...MALOIT/MET
SHORT TERM...DW
LONG TERM...JC
AVIATION...SEARS
MARINE...JC/MALOIT/DW
HYDROLOGY...DW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1201 AM EDT TUE OCT 9 2012
.SYNOPSIS...
LOW PRESSURE FORMING ALONG THE MID ATLANTIC COAST OVERNIGHT
WILL SLOWLY TRACK NORTHEAST...PASSING EAST OF THE TRI-STATE AREA
TUESDAY EVENING. HIGH PRESSURE THEN BRIEFLY BUILDS BACK IN BEHIND
THE LOW TUESDAY NIGHT. A COLD FRONT MOVES THROUGH WEDNESDAY
AFTERNOON AND EVENING...WITH HIGH PRESSURE BUILDING IN ON
THURSDAY. ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY...FOLLOWED BY
HIGH PRESSURE ON SATURDAY. A WARM FRONT WILL THEN PASS BY ON
SUNDAY...FOLLOWED BY A COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WITH THE DRY AIR REMAINING IN THE AREA HAVE LOWERED POPS UNTIL
LATE TONIGHT WHEN SHORTWAVE PASSES ACROSS THE EASTERN ZONES.
00Z KOKX SHOWS A STRONG DRY LAYER BETWEEN 975-725 HPA AND THE 00Z
KALY SOUND FROM THE SURFACE-575 HPA. THIS GOES ALONG WAY TO
EXPLAINING WHY ANY MEASURABLE RAINFALL HAS BASICALLY REMAINED
OFFSHORE SO FAR THIS EVENING. THE HRRR AND RUC ARE HANDLING THE
CURRENT SITUATION THE BEST...SO HAVE USED TO UPDATE THE FORECAST
FOR OVERNIGHT...SIGNIFICANTLY LOWERING POPS...ESPECIALLY ACROSS
THE NORTHERN INTERIOR AND NW 1/3 OF THE CWA.
LOOKING FURTHER AT THE NAM - GIVEN THE VORTICITY MINIMA IT
FORECASTS AT 700 HPA OVER THE AREA OVERNIGHT - IT IS SURPRISING
THAT IT IS FORECASTING AS MUCH RAIN AS IT DOES. TYPICALLY WITH
THESE FEATURES AT 700 HPA...IT GOES WITH MINIMAL PRECIPITATION AND
ENDS UP BEING CORRECT. SO THE LOWER POPS ARE ALSO CONSISTENT WITH
THE NAM 700 HPA VORTICITY FIELDS.
STILL LOOKS LIKE THE TWIN FORKS COULD GET SOME LIGHT-MODERATE RAIN
LATE - OTHERWISE AT MOST A TENTH OF AN INCH - WITH MOST AREAS
CLOSER TO 0.01 INCHES.
TEMPERATURE FORECAST ON TRACK BASED ON MAV/MET BLEND WITH NEAR
NORMAL LOWS EXPECTED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
RAIN WILL BE LIKELY DURING THE MORNING HOURS...ESPECIALLY ALONG THE
COAST. THERE WILL BE PLENTY OF LOW-LEVEL MOISTURE IN PLACE WITH A
LOW-LEVEL NE FLOW AND A SW FLOW ALOFT. CONDITIONS WILL DRY OUT
FROM WEST TO EAST DURING THE AFTERNOON HOURS AS THE LOW PASSES TO
THE E AND THEN NE BY EVE. HIGHS WILL BE AROUND 60...WHICH IS
SEVERAL DEGREES BELOW NORMAL.
FOR TUE NIGHT....WITH WEAK LOW-LEVEL WARM ADVECTION...STRATUS
WILL REMAIN ACROSS THE ENTIRE AREA. THERE MAY EVEN BE A LITTLE
DRIZZLE AND/OR LIGHT RAIN DEVELOPING OVERNIGHT WITH AN E/SE
FLOW...ESPECIALLY ACROSS THE HILLS NORTH AND WEST OF NYC. LOWS
WILL ONCE AGAIN BE IN THE MID 40S TO AROUND 50.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THE LONGWAVE PATTERN DURING THE LONG TERM PERIOD IS FORECAST TO BE
PROGRESSIVE WITH A LACK OF DEEP AMPLIFICATION. IN
SHORT...RELATIVELY QUICK MOVING SURFACE FEATURES PASS THROUGH THE
FORECAST AREA.
ON WEDNESDAY...A PRE-FRONTAL SURFACE TROUGH MOVES THROUGH. IT LOOKS
LIKE THERE WILL BE DEEP ENOUGH MOISTURE TO WARRANT SLIGHT CHANCE
POPS. BY THE TIME THE TRAILING COLD FRONT ARRIVES LATE IN THE DAY
INTO THE EVENING HOURS....MODELS SHOW DRYING OF THE COLUMN. WILL
THEREFORE CARRY ONLY SLIGHT CHANCE POPS FOR THIS PERIOD. LEANED A
LITTLE MORE TOWARDS THE COOLER NAM MOS DUE TO THE ANTICIPATED CLOUD
COVER...HOWEVER...HIGH TEMPERATURES NEAR NORMAL.
HIGH PRESSURE BUILDS IN ON THURSDAY BEHIND THE COLD FRONT. BUT
BECAUSE OF THE PROGRESSIVE FLOW...RISING HEIGHTS AND SOME AIR MASS
MODIFICATION/MODERATION IS FORECAST BY LATE IN THE DAY. AFTERNOON
HIGHS ARE NOT EXPECTED TO BE SIGNIFICANTLY COOLER...BUT STILL
FALLING BELOW NORMAL LEVELS.
THE NEXT COLD FRONT PASSAGE IS EXPECTED ON FRIDAY. MODELS SHOWING
ONLY LIGHT QPF OUTPUT...SO WON`T BUMP UP POPS JUST YET FROM THE
CURRENT FORECAST OF SLIGHT CHANCE.
HIGH PRESSURE RETURNS ON SATURDAY. THE ORIGIN OF THIS AIRMASS WILL
BE SOMEWHAT MORE DIRECT FROM CANADA WITH LESS TIME TO MODIFY.
THEREFORE EXPECTING TEMPERATURES COOLER THAN THOSE USHERED IN BY
THE HIGH PRESSURE SYSTEM ON THURSDAY.
WITH THE CENTER OF THE HIGH OFFSHORE ON SUNDAY...A RETURN SOUTHERLY
FLOW AND WARM FRONT ENTER THE REGION. MODELS HAVE BEEN TRENDING
FARTHER NORTH REGARDING THE COVERAGE OF QPF ASSOCIATED WITH THE WARM
FRONT. WILL KEEP IN A SLIGHT CHANCE OF SHOWERS NORTH OF THE CITY
LATE SATURDAY INTO SUNDAY MORNING...BUT IT IS LOOKING MORE LIKE A
COMPLETELY DRY UPCOMING WEEKEND ACROSS THE AREA. A TRAILING COLD
FRONT DROPS DOWN FROM THE NORTH ON MONDAY. WITH THE TIMING OF ITS
PASSAGE SOMEWHAT UNCERTAIN...WILL GO WITH SLIGHT CHANCE POPS SUNDAY
NIGHT THROUGH MONDAY NIGHT...BUT MOST OF THE TIME SHOULD BE DRY.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
AS HIGH PRES LIFTS NE INTO THE CANADIAN MARITIMES TONIGHT...LOW
PRES DEVELOPING OFF THE NORTH CAROLINA COAST WILL TRACK NE
THROUGH TUE MORNING...PASSING E OF LONG ISLAND TUE NIGHT.
DRY AIR BELOW 10K HAS BEEN THE CAUSE OF RAIN ERODING AS IT
APPROACHES THE AREA FROM SE PA/MD/VA. THERE ARE A FEW NARROW BANDS
THAT REMAIN...BUT ARE EXPECTED TO MISS MOST TERMINALS. KSWF/KJFK
MAY SEE A BRIEF PERIOD OF LIGHT RAIN THROUGH 05Z...BUT THE MAJORITY
OF THE ACTIVITY IS EXPECTED TO REMAIN TO OUR S AND E. KISP/KGON
HAVE THE HIGHEST CHC OF SEEING ANY PRECIP FROM THE OFFSHORE LOW
LATE TONIGHT. IN ADDITION...AS A MID LEVEL DISTURBANCE MOVES
CLOSER TO THE AREA...RAIN COULD REDEVELOP AT WESTERN TERMINALS AS
WELL...SO HAVE KEPT A PERIOD OF PREVAILING RAIN LATE TONIGHT
ALTHOUGH TIMING MAY BE OFF.
LOW LEVEL MOISTURE WILL INCREASE AND STILL EXPECTING CIGS TO FALL
BELOW 3 KFT OVERNIGHT...BUT THINKING NOT UNTIL AFT 06Z. VSBYS
EXPECTED TO REMAIN AOA 6SM EXCEPT IN ANY LOCALIZED HEAVIER
RAINFALL. THE CHANCE OF THIS IS TOO SMALL...THEREFORE HAVE REMOVED
ANY VSBYS LOWER THAN 6SM. CONDS EXPECTED TO REMAIN ABOVE IFR THROUGH
THE PERIOD WITH MARGINAL IMPROVEMENT TUESDAY AFTN.
WINDS EXPECTED TO BECOME NE AT ALL TERMINALS BY 06Z. AS THE PRES
GRADIENT TIGHTENS OVERNIGHT WINDS WILL INCREASE FURTHER AND EXPECT
8-15 KT ON TUE...HIGHEST SPEEDS AT KGON.
OUTLOOK FOR 00Z TUESDAY THROUGH SATURDAY...
.TUESDAY NIGHT...MVFR AND WDLY SCT SHOWERS POSSIBLE.
.WEDNESDAY...MVFR CONDS POSSIBLE IN -SHRA WITH COLD FRONT
PASSAGE.
.THURSDAY-SATURDAY...VFR.
&&
.MARINE...
MINOR ADJUSTMENTS MADE TO REFLECT LATEST TRENDS IN OBSERVATIONS AND
GUIDANCE. APPEARS WINDS/SEAS WILL REMAIN BENIGN INTO THE OVERNIGHT
HOURS.
A SCA HAS BEEN HOISTED FOR THE OCEAN WATERS TUE-WED MORNING. A
STRENGTHENING NE FLOW AHEAD OF LOW PRESSURE TRACKING NE FROM THE
MID ATLANTIC COAST WILL PRODUCE MARGINAL WIND GUSTS AND SEAS RIGHT
AROUND 5 FT. CONDITIONS WILL BRIEFLY IMPROVE TUE NIGHT AS THE LOW
PASSES TO THE NORTH AND EAST OF THE WATERS. THE REMAINDER OF THE
WATERS SHOULD EXPERIENCE SUB-SCA CONDITIONS TONIGHT-TUESDAY NIGHT.
LOOKS LIKE SUB SCA CONDITIONS SHOULD CONTINUE THROUGH WEDNESDAY
AFTERNOON...BUT WITH A COLD FRONT MOVING THROUGH IN THE
EVENING...WINDS AND SEAS PICK UP...AND MOST IF NOT ALL OF THE AREA
WATERS STAND A GOOD CHANCE OF SCA CONDITIONS. WINDS AND SEAS
SUBSIDE THROUGH THURSDAY WITH HIGH PRESSURE AND A WEAK PRESSURE
GRADIENT IN CONTROL...SO BY LATE IN THE DAY...ALL WATERS ARE
EXPECTED TO HAVE SUB SCA CONDITIONS. ANOTHER COLD FRONT APPROACHES
BEFORE MOVING THROUGH DURING FRIDAY. SCA CONDITIONS PROBABLE ON
SOME OF THE WATERS DURING THIS PERIOD. HIGH PRESSURE WITH A WEAK
PRESSURE RESTORES TRANQUIL CONDITIONS AGAIN ON SATURDAY.
&&
.HYDROLOGY...
RAINFALL FROM LATE THIS AFTERNOON THROUGH TUESDAY MORNING WILL
TOTAL FROM AROUND A FEW HUNDREDTHS OF OF AN INCH ACROSS THE LOWER
HUDSON VALLEY INTO PORTIONS OF NORTHEASTERN NEW JERSEY TO AROUND A
QUARTER TO ONE THIRD OF ACROSS EASTERN LONG ISLAND. THE RAIN WILL
BE MAINLY LIGHT. NO FLOODING IS EXPECTED.
NO SIGNIFICANT RAINFALL EXPECTED MID WEEK THROUGH THE WEEKEND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...MALOIT/MET
SHORT TERM...DW
LONG TERM...JC
AVIATION...24
MARINE...JC/MALOIT/DW/MET
HYDROLOGY...DW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1153 PM MDT MON OCT 8 2012
.UPDATE...
ISSUED AT 1039 PM MDT MON OCT 8 2012
LATEST REGIONAL RADAR IMAGERY SHOWS THE COLD FRONT ALREADY OVER
SOUTHERN NEBRASKA...WELL AHEAD OF WHERE THE MODELS HAVE THE FRONT.
BEHIND THE FRONT TEMPERATURES ARE STILL IN THE MID 40S TO MID
50S UP INTO SOUTH DAKOTA...AIDED BY THE OVERCAST SKIES BEHIND THE
FRONT WHILE COOLER AIR IS BEGINNING TO ENTER THE NORTHWEST PART
OF THE STATE.
IF THE FRONT CONTINUES AT ITS PRESENT SPEED IT WILL BE THROUGH THE
AREA BEFORE SUNRISE. WITH A QUICKER FRONTAL PASSAGE...AM THINKING
THE WINDS BEHIND THE FRONT WILL NOT HAVE TIME TO MIX
TO THE GROUND WITH THE INVERSION IN PLACE. INSTEAD OF MIXING THE
MAIN CONTRIBUTOR TO THE WIND WILL BE THE RAPID PRESSURE RISES
BEHIND THE FRONT DURING THE MORNING...WHICH MAY LEAD TO GUSTS OF
40 MPH. THE WINDS WILL DECLINE DURING THE AFTERNOON AS THE FRONT
MOVES FURTHER SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 128 PM MDT MON OCT 8 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE SCALE
TROUGH DOMINATING PATTERN ACROSS NORTH AMERICAN...WITH BROAD
LONG WAVE TROUGH IN PLACE OVER CANADA. ON TROUGH AXIS EXTENDS SOUTH
ALONG THE MISSISSIPPI RIVER VALLEY...WITH A CLOSED UPPER LOW OFF THE
CALIFORNIA COAST. W/NW FLOW IS IN PLACE OVER THE TRI STATE REGION
WITH A SHORTWAVE TROUGH UPSTREAM OVER WYOMING. AT THE SURFACE A COLD
FRONT IS CURRENTLY EXTENDING ACROSS SOUTHERN MONTANA INTO THE
NORTHERN PART OF SOUTH DAKOTA.
THIS COLD FRONT IS EXPECTED TO DROP SOUTH ACROSS THE CWA BETWEEN
09-12Z...WITH WINDS INCREASING BEHIND IT. I HAVE CONCERNS THAT WE
MAY REACH WIND ADVISORY CRITERIA ACROSS OUR SOUTHEAST BETWEEN
12-15Z...WITH ADVERTISED PRESSURE RISES BETWEEN 8-11MB AND H85 WINDS
AROUND 14Z. THE BIGGEST QUESTION WILL BE WHETHER THESE WINDS CAN MIX
DOWN BEFORE THE PRESSURE GRADIENT BEGINS TO WEAKEN OVER OUR CWA. FOR
I INCREASED WINDS TO JUST BELOW ADVISORY CRITERIA...WITH CONFIDENCE
TOO LOW AT THIS TIME. LARGE SCALE ASCENT AND BEST MOISTURE SHOULD
REMAIN WELL NORTH OF THE CWA...SO ONLY MID-HIGH CLOUDS ARE EXPECTED
TUESDAY MORNING.
ON ANOTHER NOTE...NAM/SREF CONTINUE TO ADVERTISE POSSIBLE FOG
DEVELOPMENT ACROSS THE NORTHWEST. THIS COINCIDES WITH THE AREAS
THAT RECEIVED SNOW SEVERAL DAYS AGO THAT HAS ALREADY MELTED. BOTH
MODELS HAVE SIGNIFICANTLY HIGHER TD VALUES THAN WHAT IS CURRENTLY
OCCURRING...SO CONSIDERING THIS BIAS I WILL NOT BE INCLUDING FOG IN
THE FORECAST FOR TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 131 PM MDT MON OCT 8 2012
SHORTWAVE RIDGING WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY
WITH TEMPERATURES NEAR NORMAL AND DRY CONDITIONS. A CUT OFF LOW
WILL MOVE ACROSS THE SOUTHERN AND CENTRAL ROCKIES LATE THIS WEEK.
CURRENTLY THE MODELS BRING THE SYSTEM INTO THE LOCAL AREA FRIDAY
AND SATURDAY...HOWEVER TIMING MAY BE TOO FAST GIVEN PREVIOUS
EXPERIENCE WITH CUT OFF SYSTEMS AND IT MAY NOT ARRIVE UNTIL FRIDAY
NIGHT OR SATURDAY AND DEPART SATURDAY NIGHT OR SUNDAY. THERE WILL
BE A CHANCE FOR SEVERE THUNDERSTORMS AS THE MAIN DYNAMICS ARRIVE
FOLLOWED BY A DRY SLOT AND EVENTUALLY SOME LIGHT WRAPAROUND
PRECIPITATION ON THE BACKSIDE. THERE IS NOT MUCH COLD AIR WITH THE
SYSTEM SO NO WINTRY WEATHER EXPECTED. NORTHWEST FLOW WILL BECOME
ESTABLISHED EARLY NEXT WEEK WITH A HINT OF ANOTHER SHORTWAVE
TROUGH...THOUGH MOISTURE MAY BE LIMITED WITH THAT SYSTEM.
TEMPERATURES WILL BE BELOW NORMAL FRIDAY THROUGH SUNDAY WITH THE
PRECIPITATION AND CLOUDS...THEN NEAR NORMAL EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1146 PM MDT MON OCT 8 2012
MVFR TO VFR CONDITIONS ARE FORECAST FOR BOTH TAF SITES. LATEST
RADAR IMAGERY SHOWS THE COLD FRONT JUST NORTH OF KMCK...ARRIVING
AROUND 7Z WITH A 9Z ARRIVAL AT KGLD. MODELS SHOW AN INCREASE IN
LOW LEVEL MOISTURE DURING THE MORNING BEHIND THE COLD FRONT. MAY
HAVE SOME LOW CLOUDS DEVELOP OVER BOTH SITES AS A RESULT. THE
SKIES SHOULD CLEAR DURING THE AFTERNOON AS DRIER AIR MOVES IN.
OTHERWISE WINDS WILL BE STRONGEST DURING THE MORNING THEN DECLINE
DURING THE AFTERNOON AS THE FRONT MOVES FURTHER SOUTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1056 PM MDT MON OCT 8 2012
.UPDATE...
ISSUED AT 1039 PM MDT MON OCT 8 2012
LATEST REGIONAL RADAR IMAGERY SHOWS THE COLD FRONT ALREADY OVER
SOUTHERN NEBRASKA...WELL AHEAD OF WHERE THE MODELS HAVE THE FRONT.
BEHIND THE FRONT TEMPERATURES ARE STILL IN THE MID 40S TO MID
50S UP INTO SOUTH DAKOTA...AIDED BY THE OVERCAST SKIES BEHIND THE
FRONT WHILE COOLER AIR IS BEGINNING TO ENTER THE NORTHWEST PART
OF THE STATE.
IF THE FRONT CONTINUES AT ITS PRESENT SPEED IT WILL BE THROUGH THE
AREA BEFORE SUNRISE. WITH A QUICKER FRONTAL PASSAGE...AM THINKING
THE WINDS BEHIND THE FRONT WILL NOT HAVE TIME TO MIX
TO THE GROUND WITH THE INVERSION IN PLACE. INSTEAD OF MIXING THE
MAIN CONTRIBUTOR TO THE WIND WILL BE THE RAPID PRESSURE RISES
BEHIND THE FRONT DURING THE MORNING...WHICH MAY LEAD TO GUSTS OF
40 MPH. THE WINDS WILL DECLINE DURING THE AFTERNOON AS THE FRONT
MOVES FURTHER SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 128 PM MDT MON OCT 8 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE SCALE
TROUGH DOMINATING PATTERN ACROSS NORTH AMERICAN...WITH BROAD
LONG WAVE TROUGH IN PLACE OVER CANADA. ON TROUGH AXIS EXTENDS SOUTH
ALONG THE MISSISSIPPI RIVER VALLEY...WITH A CLOSED UPPER LOW OFF THE
CALIFORNIA COAST. W/NW FLOW IS IN PLACE OVER THE TRI STATE REGION
WITH A SHORTWAVE TROUGH UPSTREAM OVER WYOMING. AT THE SURFACE A COLD
FRONT IS CURRENTLY EXTENDING ACROSS SOUTHERN MONTANA INTO THE
NORTHERN PART OF SOUTH DAKOTA.
THIS COLD FRONT IS EXPECTED TO DROP SOUTH ACROSS THE CWA BETWEEN
09-12Z...WITH WINDS INCREASING BEHIND IT. I HAVE CONCERNS THAT WE
MAY REACH WIND ADVISORY CRITERIA ACROSS OUR SOUTHEAST BETWEEN
12-15Z...WITH ADVERTISED PRESSURE RISES BETWEEN 8-11MB AND H85 WINDS
AROUND 14Z. THE BIGGEST QUESTION WILL BE WHETHER THESE WINDS CAN MIX
DOWN BEFORE THE PRESSURE GRADIENT BEGINS TO WEAKEN OVER OUR CWA. FOR
I INCREASED WINDS TO JUST BELOW ADVISORY CRITERIA...WITH CONFIDENCE
TOO LOW AT THIS TIME. LARGE SCALE ASCENT AND BEST MOISTURE SHOULD
REMAIN WELL NORTH OF THE CWA...SO ONLY MID-HIGH CLOUDS ARE EXPECTED
TUESDAY MORNING.
ON ANOTHER NOTE...NAM/SREF CONTINUE TO ADVERTISE POSSIBLE FOG
DEVELOPMENT ACROSS THE NORTHWEST. THIS COINCIDES WITH THE AREAS
THAT RECEIVED SNOW SEVERAL DAYS AGO THAT HAS ALREADY MELTED. BOTH
MODELS HAVE SIGNIFICANTLY HIGHER TD VALUES THAN WHAT IS CURRENTLY
OCCURRING...SO CONSIDERING THIS BIAS I WILL NOT BE INCLUDING FOG IN
THE FORECAST FOR TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 131 PM MDT MON OCT 8 2012
SHORTWAVE RIDGING WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY
WITH TEMPERATURES NEAR NORMAL AND DRY CONDITIONS. A CUT OFF LOW
WILL MOVE ACROSS THE SOUTHERN AND CENTRAL ROCKIES LATE THIS WEEK.
CURRENTLY THE MODELS BRING THE SYSTEM INTO THE LOCAL AREA FRIDAY
AND SATURDAY...HOWEVER TIMING MAY BE TOO FAST GIVEN PREVIOUS
EXPERIENCE WITH CUT OFF SYSTEMS AND IT MAY NOT ARRIVE UNTIL FRIDAY
NIGHT OR SATURDAY AND DEPART SATURDAY NIGHT OR SUNDAY. THERE WILL
BE A CHANCE FOR SEVERE THUNDERSTORMS AS THE MAIN DYNAMICS ARRIVE
FOLLOWED BY A DRY SLOT AND EVENTUALLY SOME LIGHT WRAPAROUND
PRECIPITATION ON THE BACKSIDE. THERE IS NOT MUCH COLD AIR WITH THE
SYSTEM SO NO WINTRY WEATHER EXPECTED. NORTHWEST FLOW WILL BECOME
ESTABLISHED EARLY NEXT WEEK WITH A HINT OF ANOTHER SHORTWAVE
TROUGH...THOUGH MOISTURE MAY BE LIMITED WITH THAT SYSTEM.
TEMPERATURES WILL BE BELOW NORMAL FRIDAY THROUGH SUNDAY WITH THE
PRECIPITATION AND CLOUDS...THEN NEAR NORMAL EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 517 PM MDT MON OCT 8 2012
MAINLY VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE TAF PERIOD
AT BOTH MCK AND GLD. A COLD FRONT WILL MOVE THROUGH BOTH TAF SITES
AROUND 12Z TOMORROW MORNING BRINGING A FEW MID TO LOW LEVEL CLOUDS
AND STRONG NORTHERLY WINDS...GUSTING UP 30KTS AT TIMES. WINDS WILL
DIMINISH BY THE EARLY AFTERNOON TO 12KTS OR LESS AS THE FRONT EXITS
THE REGION AND HIGH PRESSURE BUILDS INTO THE AREA. THERE EXISTS THE
POSSIBILITY FOR A SHORT PERIOD OF MVFR CEILINGS WITH LOW CLOUDS
ASSOCIATED WITH THE FRONTAL PASSAGE...SO ALLUDED TO THIS BY
MENTIONING A SCATTERED DECK AROUND 1800FT AT GLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JJM/JTL
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
553 AM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA
WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT USHERING IN
COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM FRONT
WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SOME TWEAKS TO THE GOING FCST TO ACCOUNT FOR LATEST
OBSERVATIONAL TRENDS. ELY WINDS HAVE PICKED UP ON THE COAST...AND
THAT IS HELPING TO PUSH SOME OF THAT HIGH MID LVL RH ONSHORE.
BLENDED THE PREVIOUS FCST WITH THE LOCAL WRF MODEL...AS IT HAD A
GOOD HANDLE ON LOCATION AND TIMING OF CLOUD DECK. ALSO SHARPENED
THE GRADIENT OF POP FOR THIS AFTN...TO KEEP ANY SHRA CONFINED TO
THE COAST ONLY.
PREVIOUS DISCUSSION...CIRRUS SHIELD ALONG THE COAST AND INTERIOR
HAS ALLOWED TEMPS TO REMAIN IN THE MID 40S UNDERNEATH THE CANOPY.
HOWEVER...ON THE FRINGES AND ACROSS THE NRN MTNS AND VALLEYS
RADIATIONAL COOLING HAS ALLOWED READINGS TO TUMBLE INTO THE 30S
WITH A FEW UPR 20S. HERE AREAS OF GROUND/VALLEY FOG WILL BE
COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /WEDNESDAY/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORNING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 AM EDT
WEDNESDAY FOR ANZ150>154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS GRAY ME
251 AM EDT TUE OCT 9 2012
.SYNOPSIS...A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA
WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT USHERING IN
COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM FRONT
WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
CIRRUS SHIELD ALONG THE COAST AND INTERIOR HAS ALLOWED TEMPS TO
REMAIN IN THE MID 40S UNDERNEATH THE CANOPY. HOWEVER...ON THE
FRINGES AND ACROSS THE NRN MTNS AND VALLEYS RADIATIONAL COOLING
HAS ALLOWED READINGS TO TUMBLE INTO THE 30S WITH A FEW UPR 20S.
HERE AREAS OF GROUND/VALLEY FOG WILL BE COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 AM EDT
WEDNESDAY FOR ANZ150>154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
439 AM EDT TUE OCT 9 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EDT TUE OCT 9 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW MEAN UPR TROF
STILL DOMINATING ERN NAMERICA DOWNSTREAM OF UPR RDG OFF THE W COAST
OF CANADA. TWO DISTURBANCES OF NOTE ARE EMBEDDED IN THIS TROF. THE
FIRST IS CURRENTLY MOVING THRU THE UPR GRT LKS...WITH 999MB SFC LO
OVER ONTARIO. AT 06Z...ATTENDANT COLD FNT IS PUSHING INTO THE WRN
CWA...PRECEDED BY A BAND OF SCT -SHRA STRETCHING FM JUST E OF THE
KEWEENAW SWWD INTO NCENTRAL WI. STRONG S WINDS ARE EVIDENT UNDER THE
SHARPER PRES GRADIENT TO THE E AS 00Z GRB RAOB INDICATED WINDS UP TO
39KTS AS LO AS 2K FT AGL AND UNSTABLE LLVL LAPSE RATES. THE WINDS
ARE STRONGEST AT EXPOSED LOCATIONS NEAR LK MI...WHERE WINDS GUSTED
AS HI AS 45-55 MPH AT SEVERAL SITES YDAY EVNG. WHILE THE DRYNESS OF
THE SUB H8 LYR SHOWN ON THE 00Z GRB RAOB RESTRICTED PCPN COVERAGE/
AMOUNTS OVER MUCH OF THE CWA AHEAD OF THE COLD FNT...MORE SHRA ARE
NOTED OVER THE ERN CWA WHERE THE S WIND UP THE LENGTH OF LK MI
ALLOWED SUFFICIENT MOISTENING TO OVERCOME THIS LLVL DRY AIR. BUT
THIS PCPN IS TENDING TO DRIFT INTO FAR ERN UPR MI AND OUT OF THE MQT
CWA. TO THE W...THERE IS PARTIAL CLRG OVER MUCH OF CENTRAL AND SRN
MN BEHIND THE COLD FROPA AS DRIER AIR SHOWN ON THE 00Z MPX RAOB
ADVECTS TO THE ENE. BUT MORE HI AND MID CLDS ASSOCIATED WITH A
STRONGER SECOND SHRTWV DROPPING SEWD INTO THE NRN PLAINS ARE
SPREADING TO THE E THRU MN AT THE SAME TIME. THE APRCH OF THIS
SHRTWV IS ALSO CAUSING A GREATER COVERAGE OF -SHRA ON THE SRN EDGE
OF THE COLD FNT OVER SE MN/NRN IOWA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE WHETHER TO ALLOW CURRENT
WIND ADVY FOR THE ERN CWA TO EXPIRE AS SCHEDULED AT 09Z AND EVENTUAL
-RA COVERAGE ASSOCIATED WITH STRONGER SECOND SHRTWV NOW DIGGING INTO
THE NRN PLAINS.
EARLY THIS MRNG...AS SHRTWV/SFC LO TO THE N MOVE TO THE NE...COLD
FNT EXTENDING S THRU UPR MI WL SHIFT TO THE E BUT TEND TO SLOW DOWN
AS SECOND SHRTWV DIGGING THRU THE NRN PLAINS DEEPENS THE UPR TROF
AXIS TO THE W AND THE FLOW ALF BACKS TO MORE SW OVER THE GREAT
LAKES. THE BAND OF -SHRA PRECEDING THE FNT WL LIKELY DRY OUT A BIT
WITH BEST FORCING EXITING TO THE NE AND LLVL DRY AIR LINGERING W OF
LIMITING STREAMLINE OFF LK MI. BUT MOISTENING OFF LK MI MIGHT ALLOW
FOR SOME EHNANCEMENT TO THE COVERAGE AGAIN ONCE THE BAND REACHES
THAT AREA. WITH THE CLOSER APRCH OF THE COLD FNT...THE PRES GRADIENT
OVER THE E WL WEAKEN SUFFICIENTLY TO ALLOW THE STRONGER S WINDS TO
DIMINISH BEFORE 12Z. SO PLANNED EXPIRATION OF WIND ADVY AT 09Z SEEMS
TO BE ON TRACK. OVER THE W...DRYING ALF WL BRING DRY WX FOR THE MOST
PART.
TODAY...AS THE UPR TROF AXIS DEEPENS TO THE W IN RESPONSE TO DIGGING
SECOND SHRTWV...EXPECT AREA OF SHRA NOW ON COLD FNT TO THE S TO
EXPAND AND MOVE NE. LATEST MODEL RUNS SHOW CONSIDERABLE SPREAD ON
WHERE AREA OF SHRA WL IMPACT. THE 00Z LOCAL WRF-ARW/CNDN MODELS ARE
FARTHEST W WITH THE TRACK OF THE HEAVIER PCPN...WHILE THE 00Z NAM IS
FARTHEST TO THE E AND IN LINE WITH CURRENT FCST. CONSIDERING THE
TRENDS ON THE INCOMING DRYING TO THE W BEHIND THE COLD FNT AS WELL
AS FCST SHARPEST H85-5 QVECTOR CNVGC OVER THE E THIS AFTN...TEND TO
THINK THE NAM IS ON THE RIGHT TRACK. THE SHARPEST H85-7 FGEN IS ALSO
OVER THE E. ON THE OTHER HAND...SINCE THE FRONTAL SLOPE WL BE RATHER
FLAT...SOME SHARP H7-5 FGEN/H7-3 QVECTOR CVNGC/H4-2 DVGC IS EVIDENT
FARTHER W AND OVER THE WRN CWA. SO EVEN IF THE HEAVIER PCPN DOES
FALL TO THE E...SUSPECT THERE WL BE AT LEAST SOME SCT -SHRA OVER THE
W...WHERE THE HIER DYNAMICS WL HAVE TO OVERCOME MORE LLVL DRYING. AS
THE SHRTWV/DYNAMIC SUPPORT SHIFTS TO THE NE LATER IN THE DAY...
EXPECT THE POPS TO DIMINISH...LATEST OVER THE E. WITH PLENTY OF CLD
COVER AND A GRADUAL INFLUX OF COOLER AIR...EXPECT LTL DIURNAL RISE
IN TEMPS.
TONIGHT...IN THE WAKE OF THE DEPARTING SHRTWV...A CYC NW LLVL FLOW
WL ADVECT A CHILLY CNDN AIRMASS INTO THE UPR LKS. WITH H85 TEMPS
FALLING AS LO AS -7C/-5C OVER WRN/ERN LK SUP BY 12Z /COMPARED WITH
WATER TEMPS OF 7C AT THE WRN BUOY AND 11C AT THE ERN BUOY/...
OVERWATER INSTABILITY WL BECOME SUFFICIENT FOR LK EFFECT -SHRASN TO
IMPACT AREAS FAVORED BY THE LLVL NW FLOW...ESPECIALLY SINCE DEEPER
MSTR WL EXTEND TO THE DGZ. BUMPED POPS UP IN THESE AREAS ABV MODEL
GUIDANCE. WOULD NOT BE SURPRISED TO SEE 1 TO 2 INCHES OF SNOW ACCUM
OVER THE HIER TERRAIN IN AREAS FAVORED BY NW FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR THEME OF INCREASED WIND WITH SYSTEMS ROLLING THROUGH EVERY
COUPLE OF DAYS WILL CONTINUE FOR THE FORESEEABLE FUTURE.
WEDNESDAY...
THE LARGE SCALE TROUGH OVER MUCH OF THE NATION WILL BE CENTERED
ACROSS THE UPPER GREAT LAKES AT 12Z WEDNESDAY...EDGING E THROUGH THE
DAY...WITH NW FLOW RULING THE AREA. WITH NW FLOW AT THE SFC AND
ALOFT...EXPECT COOL AIR TO REMAIN IN PLACE /850MB TEMPS OF -6 TO
-8C/...WITH UPSLOPE LAKE EFFECT SHOWER ACTIVITY. SNOW WILL LIKELY
MIX IN ACROSS W PORTIONS OF THE CWA BEFORE TEMPS WARM TO NEAR 40F
AND WINDS TURN A BIT MORE WESTERLY. ANY ADDITIONAL SNOW WEDNESDAY
SHOULD TOTAL AROUND A HALF AN INCH OR LESS...AS THE INCOMING SFC
RIDGE HELPS TO SCOUR OUT SOME OF THE LOW LEVEL MOISTURE.
WEDNESDAY NIGHT THROUGH FRIDAY...
THE NEXT CLIPPER-LIKE LOW WILL SLIDE IN FROM THE NORTHWEST LATE
WEDNESDAY NIGHT INTO THURSDAY...MOVING DIRECTLY OVER LAKE SUPERIOR
AT 12Z THURSDAY. AFTER 850MB TEMPS JUMPING UP TO AROUND 0C ON
INCREASED SW WINDS...THEY SHOULD AGAIN FALL TO -6 TO -7C THURSDAY
AFTERNOON. LIKE BEFORE...ANOTHER RIDGE OF HIGH PRESSURE WILL PUSH
IN...DRYING US OUT THURSDAY NIGHT AND FRIDAY. THIS TIME THE SFC HIGH
WILL MOVE OVER OR JUST S OF THE AREA /ACROSS WI AND LAKE MI FRIDAY
AFTERNOON/...WITH MUCH LIGHTER WINDS AT LEAST TEMPORARILY.
FRIDAY NIGHT THROUGH MONDAY...
THE HIGH WILL QUICKLY SLIDE TO THE LOWER GREAT LAKES FRIDAY
NIGHT...AS LOW PRESSURE ORGANIZES OFF THE ROCKIES. THE STRENGTHENING
LOW WILL SLIDE IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING
MUCH WARMER AIR ON STRONG SOUTHERLY WINDS...AND THE POTENTIAL FOR
MODERATE TO HEAVY RAIN...BEFORE EXITING NORTHEAST ON SUNDAY. FCST
MODELS HAVE BEEN FAIRLY CONSISTANT ON THE TRACK OF THE LOW OVER
UPPER MI...SO HAVE INCREASED POPS TO 80 PERCENT OR BETTER SATURDAY
AND SATURDAY NIGHT OVER CENTRAL AND E AREAS...AS WELL AS ADDED A
NON-DIURNAL TEMP TREND SATURDAY NIGHT /PARTICULARLY E WITH THE
CONTINUED S WINDS OFF LAKE MI/.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 132 AM EDT TUE OCT 9 2012
DESPITE A SERIES OF DISTURBANCES PASSING ACROSS THE UPPER GREAT
LAKES...VFR CONDITIONS SHOULD PREVAIL THRU MOST OF THE TAF PERIOD
AT KIWD/KCMX/KSAW AS LOW-LEVELS REMAIN RELATIVELY DRY UNDER
CONTINUED ADVECTION OF DRIER AIR FROM THE S. DISTURBANCE TONIGHT MAY
STILL PRODUCE A PERIOD OF -SHRA AT KSAW INTO THE EARLY OVERNIGHT.
PASSAGE OF A COLD FRONT WILL LEAD TO GUSTY WINDS INTO THE EARLY
OVERNIGHT. A SECOND DISTURBANCE MOVING INTO THE UPPER GREAT LAKES
TUE WILL BRING A ROUND OF -SHRA TO KSAW. IT APPEARS KCMX/KIWD MAY BE
JUST W OF THE MAIN PCPN AREA. AS A SECONDARY COLD FRONT MOVES
THROUGH THE AREA LATE TUE EVENING...WINDS WILL SHIFT WRLY AND COULD
BRING IN SOME MVFR LAKE CLOUDS INTO KIWD AND KCMX LATE IN THE TAF
PD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND...WITH
ANOTHER SYSTEM SLIDING IN FOR THE WEEKEND. EXITING LOW PRESSURE JUST
NORTH OF LS WILL SWEEP A TROUGH ACROSS CENTRAL AND EASTERN LS
TODAY...WITH A COOLER SECONDARY TROUGH ROTATING THROUGH TONIGHT. THIS
WILL BRING NORTHWESTERLY WINDS BACK TO THE REGION THROUGH EARLY
WEDNESDAY /WITH SOME NW GALE FORCE GUSTS TO 35 KTS WEDNESDAY ACROSS E
LS/. AFTER A QUICK RIDGE PUSHES IN...THE NEXT LOW WILL SLIDE IN FROM
THE NW LATE WEDNESDAY NIGHT INTO THURSDAY /WITH W GUSTS AGAIN OF
30-35KTS THURSDAY INTO THURSDAY EVENING/...BEFORE HIGH PRESSURE MOVES
OVERHEAD WITH TEMPORARILY LIGHTER WINDS FRIDAY. A STRENGTHENING LOW
WILL PUSH IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING STRONGER
SOUTHERLY WINDS BEFORE EXITING NE OF LS ON SUNDAY. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR MIZ006-007-
013-014-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LSZ248>251.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LMZ248-250.
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 AM EDT TUE OCT 9 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 436 PM EDT MON OCT 8 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF
DOMINATING ERN NAMERICA DOWNSTREAM OF A RIDGE/ANTICYCLONE OVER THE
GULF OF ALASKA. A COUPLE OF SHORTWAVES ARE EVIDENT DROPPING SE INTO
THE ERN TROF. ONE IS HEADING INTO NRN MN WHILE A SECOND STRONGER
WAVE IS DROPPING THRU SRN SASKATCHEWAN. AT THE SFC...LOW PRES
ASSOCIATED WITH THE LEAD WAVE IS OVER NW MN WITH SECONDARY CENTER
VCNTY OF LAKE WINNIPEG. IN REPONSE TO APPROACHING SHORTWAVE...12Z
RAOBS AT 850MB SHOW STRONG WAA INTO THE UPPER LAKES...CORRESPONDING
TO STRONG ISENTROPIC ASCENT PER LATEST RUC ANALYSIS. LINGERING DRY
AIR AT THE LOW LEVELS PER 12Z KGRB/KMPX SOUNDING IS SO FAR LIMITING
SRN EXTENT OF PCPN.
SHORT TERM WILL BE ACTIVE WITH THE 2 AFOREMENTIONED SHORTWAVES
AFFECTING THE AREA. PRIMARY CONCERN TONIGHT WILL BE WINDS WITHIN
TIGHT PRES GRADIENT OVER THE AREA...ESPECIALLY THE ERN FCST AREA
WHERE 925MB WINDS ARE PROGGED AT 40-50KT BY NAM/GFS. LOW-LEVEL WIND
MAX WON`T BE PASSING DURING THE FAVORABLE PART OF THE DIURNAL CYCLE
FOR MIXING. HOWEVER...AREA OF DECENT PRES FALLS PASSING JUST N OF
LAKE SUPERIOR WILL CERTAINLY BE AN ENHANCING FACTOR FOR STRONGER
WINDS. SO...CURRENT WIND ADVY LOOKS ON TRACK FOR THE DELTA/SRN
SCHOOLCRAFT WHICH ARE EXPOSED TO STRONG WINDS UP LAKE MICHIGAN.
SINCE S WINDS ARE A VERY FAVORABLE WIND DIRECTION FOR STRONGER WINDS
AT GRAND MARAIS AND KERY...OPTED TO INCLUDE ALGER/NRN SCHOOLCRAFT
AND LUCE COUNTIES IN ADVY AS WELL. AS FOR PCPN...GIVEN RADAR/SFC OB
TRENDS AND MODEL INDICATED PERIOD OF DEEP LAYER FORCING PER QVECTORS
AND STRONG ISENTROPIC ASCENT...SOME -SHRA APPEAR LIKELY TO MOVE
ACROSS THE AREA TONIGHT...ESPECIALLY NRN UPPER MI...DESPITE CURRENT
LOW-LEVEL DRY AIR. ALTHOUGH STRONGER FORCING WILL BEGIN TO LIFT
NE...FLOW UP LAKE MICHIGAN MAY PROVIDE ENOUGH LOW-LEVEL MOISTENING
TO ENHANCE PCPN CHANCE FOR THE ERN FCST AREA.
ON TUE...ATTENTION TURNS TO THE STRONGER SHORTWAVE CURRENTLY
DROPPING THRU SRN SASKATCHEWAN. IN RESPONSE...A NICE SW-NE ORIENTED
BAND OF FRONTOGENESIS DEVELOPS THRU THE WRN GREAT LAKES. MAJORITY OF
GUIDANCE APPEARS TO HAVE A BIT TOO MUCH PCPN ON THE COLD SIDE OF THE
FGEN CIRCULATION. BASED ON FGEN...THE ERN FCST SHOULD BE FAVORED FOR
PCPN...AND GRIDS REFLECT THIS WITH A GRADIENT FROM SCHC/LOW CHC POPS
OVER THE W TO HIGH LIKELY OVER THE E.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 436 PM EDT MON OCT 8 2012
ACTIVE PATTERN CONTINUES THROUGH THE WEEKEND. THE PATTERN FEATURES A
SYSTEM MOVING THROUGH EVERY COUPLE DAYS...FOLLOWED BY 12-24HRS OF LK
EFFECT PRECIPITATION AND THEN A WEAK HIGH PRESSURE RIDGE FOR ANOTHER
12-24HRS. THIS WILL CONTINUE THROUGH SUNDAY NIGHT. DUE TO THE
FREQUENT SYSTEMS MOVING THROUGH...IT WILL BE BREEZY THROUGH MUCH OF
THE PERIOD...ESPECIALLY OVER/NEAR LAKE SUPERIOR...WITH THE ONLY
TIMES WINDS WILL BE LIGHTER ARE DURING THE HIGH PRESSURE RIDGES ON
WED AFTN/EVENING AND FRIDAY.
FIRST LOW PRESSURE SYSTEM EXITING TO THE NE THROUGH ONTARIO AT THE
START OF THE PERIOD WHILE SFC TROUGH WILL BE OVER THE ERN CWA. NAM
DIFFERS FROM THE REST OF THE LARGE SCALE MODELS IN DEVELOPING
ANOTHER LOW OVER ERN LK SUPERIOR AS A SECONDARY SHORTWAVE AND LEFT
FRONT OF UPPER JET MOVE THROUGH. NOT SEEING THAT ON THE
LOCAL/NATIONAL HI-RES WRF RUNS...SO WILL DISREGARD AT THIS POINT.
PCPN SHOULD BE ONGOING OVER THE ERN THIRD OF THE CWA AHEAD OF THE
SFC TROUGH AND ASSOCIATED WITH SHORTWAVE FORCING.
BEHIND THE TROUGH...WINDS WILL SHIFT TO THE NW AND COLDER H850
TEMPS WILL SURGE SE...FALLING TO -7C BY 12Z WED. LAKE
EFFECT SHOWERS SHOULD DEVELOP THROUGH THE NIGHT...WITH THE
STRONGEST INTENSITY OVERNIGHT INTO WED MORNING. CURRENT FORECAST IS
FOR ABOUT AN INCH OVER THE HIGHER TERRAIN AREAS OF THE WRN U.P.
TUES NIGHT INTO WED MORNING. LLVL MOISTURE WILL QUICKLY PULL OUT
FROM W TO E DURING THE DAY WED AS WINDS BACK TO THE WSW IN RESPONSE
TO THE HIGH PRESSURE RIDGE MOVING THROUGH.
NEXT LOW PRESSURE SYSTEM MOVES RIGHT ACROSS LAKE SUPERIOR AS
SHORTWAVE DROPS THROUGH THE WNW FLOW. WITH THE BEST WAA/FORCING
LIKELY OVER LK SUPERIOR...WILL CONTINUE TO MENTION HIGHEST POPS
THERE AND ONLY SLIGHTS/CHANCES OVER THE SRN CWA. P-TYPE COULD BE AN
ISSUE WITH THIS SYSTEM OVER THE NRN PART OF THE CWA...MAINLY OVER
THE KEWEENAW. WITH THE DEEP MOISTURE THROUGH THE SNOW GROWTH
LAYER...EXPECT THE PCPN TO START AS SNOW. BUT LOOKING AT THE LOWER
LEVELS...DOESN/T APPEAR TO BE TOO MUCH WARM AIR TO WORK WITH. A
NEARLY ISOTHERMAL LAYER AT FREEZING FROM 1-3KFT BEFORE WARMING A
DEGREE OR TWO ABOVE FREEZING AT THE SURFACE. IN THE HEAVIER PCPN
AREAS...WOULD THINK THIS WOULD DEFINITELY STAY AS ALL SNOW...BUT
LIGHTER AREAS WOULD PROBABLY BE A MIX. FARTHER SOUTH...EXPECT A
RAIN/SNOW MIX DUE TO THE LIKELY WEAKER INTENSITY. ONCE
AGAIN...SHOULD SEE SOME LAKE EFFECT SHOWERS BEHIND THE LOW ON THURS
NIGHT INTO FRIDAY...BEFORE HIGH PRESSURE BUILDS BACK IN AND BRINGS
AN END TO THE SHOWERS.
WEEKEND SYSTEM HAS SHIFTED A LITTLE FARTHER NORTH OVER THE LAST
DAY...WITH THE STRENGTHENING SURFACE LOW NOW TRACKING OVER UPPER MI.
THIS SYSTEM IS CAUSED BY THE UPPER LOW CURRENTLY OFF THE CALIFORNIA
COAST MOVING THROUGH THE SW CONUS THIS WEEK AND EXITING INTO THE
PLAINS ON FRI NIGHT. LOCATION AND TIMING ARE IN DECENT AGREEMENT
WITH THE MODELS...ALTHOUGH THE CANADIAN AND IT/S ENS MEMBERS VARY
GREATLY FROM GFS/ECMWF. LOOKING AT 00Z GFS ENS MEMBERS...THE MEAN OF
THE MAJORITY OF MEMBERS WOULD GIVE A SOLN SIMILAR TO THE
00Z DETERMINISTIC ECMWF...WHICH THE 12Z DETERMINISTIC GFS TRENDED
TOWARDS AND WILL FOLLOW THAT SOLN. WITH THE FARTHER NORTH SOLUTION
THAN YESTERDAY...HAVE BUMPED UP POPS FOR THE SAT INTO SUNDAY PERIOD.
WARM AIR SURGING NORTH AHEAD OF THE SYSTEM SHOULD LEAD TO THE PCPN
STAYING RAIN. COULD BE SOME RUMBLES OF THUNDER ON SAT NIGHT...AS
SHOWALTER VALUES FALL TO 0 TO -1C ALONG AND JUST AHEAD OF THE SFC
LOW...ALTHOUGH MID LVL LAPSE RATES ARE MARGINAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 132 AM EDT TUE OCT 9 2012
DESPITE A SERIES OF DISTURBANCES PASSING ACROSS THE UPPER GREAT
LAKES...VFR CONDITIONS SHOULD PREVAIL THRU MOST OF THE TAF PERIOD
AT KIWD/KCMX/KSAW AS LOW-LEVELS REMAIN RELATIVELY DRY UNDER
CONTINUED ADVECTION OF DRIER AIR FROM THE S. DISTURBANCE TONIGHT MAY
STILL PRODUCE A PERIOD OF -SHRA AT KSAW INTO THE EARLY OVERNIGHT.
PASSAGE OF A COLD FRONT WILL LEAD TO GUSTY WINDS INTO THE EARLY
OVERNIGHT. A SECOND DISTURBANCE MOVING INTO THE UPPER GREAT LAKES
TUE WILL BRING A ROUND OF -SHRA TO KSAW. IT APPEARS KCMX/KIWD MAY BE
JUST W OF THE MAIN PCPN AREA. AS A SECONDARY COLD FRONT MOVES
THROUGH THE AREA LATE TUE EVENING...WINDS WILL SHIFT WRLY AND COULD
BRING IN SOME MVFR LAKE CLOUDS INTO KIWD AND KCMX LATE IN THE TAF
PD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 PM EDT MON OCT 8 2012
TIGHT PRES GRADIENT BTWN LOW PRES APPROACHING FROM NW MN AND HIGH
PRES TO THE E COMBINED WITH AREA OF PRES FALLS PASSING JUST N OF
LAKE SUPERIOR WILL RESULT IN S GALES ACROSS ROUGHLY THE E HALF OF
LAKE SUPERIOR TONIGHT. COULD BE A FEW HRS LATE EVENING INTO THE
EARLY OVERNIGHT WITH GUSTS TO AROUND 45KT AT HIGHER OBS PLATFORMS.
WITH PASSAGE OF COLD FRONT...WINDS WILL DIMINISH SOME OVERNIGHT.
HOWEVER...WIND SWITCH TO THE WSW ALONG WITH PRES RISE HEADING FOR
WRN LAKE SUPERIOR COULD LEAD TO A SHORT PERIOD OF GALE FORCE GUSTS
IN THE AREA BTWN ISLE ROYALE AND THE KEWEENAW. WEAKENING PRES
GRADIENT WILL LEAD TO WINDS DIMINISHING TO MOSTLY 15-25KT TUE.
ACTIVE PERIOD ON LAKE SUPERIOR CONTINUES TUESDAY NIGHT AS NORTHWEST
WINDS INCREASE TO 30KTS BEHIND THE SURFACE TROUGH MOVING ACROSS THE
LAKE ON TUESDAY. THERE COULD BE SOME GALE FORCE GUSTS TO 35KTS OVER
THE EASTERN LAKE TUESDAY NIGHT INTO WEDNESDAY...BEFORE A HIGH
PRESSURE RIDGE DECREASES WINDS BELOW 25KTS. THE NEXT SYSTEM WILL MOVE
ACROSS LAKE SUPERIOR LATE WEDNESDAY NIGHT INTO THURSDAY. THIS WILL
AGAIN PRODUCE WEST GUSTS TO 30-35KTS ON THURSDAY AND THURSDAY
EVENING. WEAKER WINDS WILL PREVAIL ON FRIDAY AS HIGH PRESSURE SLIDES
OVER THE GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR MIZ006-007-
013-014-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ265>267.
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LSZ248>251.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LMZ248-250.
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON/SRF
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 PM CDT MON OCT 8 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
235 PM CDT MON OCT 8 2012
MAIN FORECAST CONCERN IS ON RAIN CHANCES FOR TONIGHT AND TUESDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE NORTHEAST PACIFIC AND TROUGHING ACROSS
CENTRAL AND EASTERN CANADA. WITHIN THIS TROUGH...THERE ARE TWO
SHORTWAVE TROUGHS OF NOTE. THE FIRST IS OVER NORTHERN MINNESOTA...
WITH AN ASSOCIATED 998MB SURFACE LOW OVER NORTHWEST MINNESOTA. DPVA
AHEAD OF THE SHORTWAVE IN CONJUNCTION WITH WARM ADVECTION/ISENTROPIC
LIFT HAS SUPPORTED A LARGE AREA OF ALTOSTRATUS ACROSS MINNESOTA INTO
THE NORTHWEST HALF OF WISCONSIN. DRY LOW LEVEL AIR SEEN ON THE 12Z
MPX SOUNDING AS WELL AS SURFACE RELATIVE HUMIDITIES IN THE 25-40
PERCENT RANGE HAS KEPT THE SOUTHERN MINNESOTA DRY DESPITE LIGHT
RETURNS ON RADAR. BREEZY SOUTHWEST WINDS ARE ALSO OCCURRING ACROSS
THE FORECAST AREA AS A RESULT OF A TIGHT PRESSURE GRADIENT. THESE
SOUTHWEST WINDS ARE ADVECTING WARMER AIR INTO THE AREA...NOTED BY
850MB TEMPS PER THE RAP THAT HAVE CLIMBED TO 4-6C AFTER STARTING OFF
AT 1-3C ACCORDING TO 12Z RAOBS. COLD FRONT ASSOCIATED WITH THE LOW
PRESSURE AREA APPROACHING SIOUX FALLS SOUTH DAKOTA. THE NEXT
SHORTWAVE TROUGH OF NOTE...WHICH LOOKS QUITE POTENT IN WATER
VAPOR...IS IN SOUTHERN SASKATCHEWAN. A 100-120 KT JET NEAR 250MB WAS
LOCATED ON THE WEST/SOUTHWEST SIDE OF THIS SHORTWAVE.
TONIGHT AND TUESDAY...THE POTENT SHORTWAVE IN SASKATCHEWAN MODELS
SHOW DROPPING DOWN INTO THE DAKOTAS TONIGHT...THEN INTENSIFYING AND
TURNING NEUTRAL TILT AS IT CROSSES MINNESOTA INTO FAR WESTERN
WISCONSIN DURING THE DAY TUESDAY. AS THIS SHORTWAVE APPROACHES
TONIGHT...IT HELPS TO SLOW DOWN THE CURRENT EASTWARD PROGRESS OF THE
COLD FRONT NEAR SIOUX FALLS. IN FACT...BY 12Z...THE FRONT MAY JUST
BE GETTING INTO SOUTHEAST MN. AS SUCH...A MILD NIGHT COMPARED TO
WHAT HAS BEEN SEEN RECENTLY IS ON TAP TONIGHT...AIDED BY A
CONTINUING SOUTHWEST BREEZE AND PLENTY OF CLOUDS. THEREFORE...STAYED
ON THE WARM SIDE OF GUIDANCE. PRECIPITATION CHANCES TONIGHT ARE VERY
QUESTIONABLE BECAUSE OF THE SLOW FRONTAL PROGRESS. WHEN HEADING INTO
THE COLD SEASON...MOST PRECIPITATION FALLS POST-COLD FRONTAL BECAUSE
OF COLD AIR UNDERCUTTING THE WARM AIR. IN THIS CASE...THE
FRONTOGENESIS FORCING WHICH DOES STRENGTHEN THROUGH THE NIGHT ENDS
UP STAYING MOSTLY WEST OF THE AREA. AS SUCH...HAVE CONFINED THE
PRECIPITATION CHANCES TO MOSTLY LATE TONIGHT AND OVER THE NORTHWEST
1/3 OF THE AREA. IN ADDITION...HAVE KEPT THE CHANCES IN THE 20-40
RANGE AS CONFIDENCE IS LOW IN GETTING THE AIR SATURATED AND THE
FRONT INTO THE AREA. NOW THINGS ARE A LOT DIFFERENT ON TUESDAY. THE
FRONTOGENESIS ZONE ON TUESDAY IS PROGGED TO STRENGTHEN
DRAMATICALLY...CAUSED BY THE APPROACHING SHORTWAVE. CROSS-SECTIONS
SHOW A NICE FRONTOLYSIS/FRONTOGENESIS COUPLET WHICH YIELDS STRONG
UPWARD VERTICAL MOTION. SO ANTICIPATING THAT AS THE SHORTWAVE MOVES
IN AND PUSHES THE FRONT EAST...SHOULD SEE A BAND OF RAIN BEHIND IT.
IN FACT...MOST OF THE AREA LOOKS TO GET RAIN NOW FOR TUESDAY...
THOUGH NORTHWEST SECTIONS SHOULD DRY OUT IN THE AFTERNOON AS THE
FRONTOGENESIS FORCING HEADS EAST. WITH THE FRONT AND RAIN MOVING
THROUGH...A NON-DIURNAL TREND IS REQUIRED. PLUS...850MB TEMPS FALL
FROM 2-6C AT 12Z TO 0 TO -2C AT 00Z. HIGHS WILL TOP OUT IN THE UPPER
40S TO MIDDLE 50S AT BEST...AND FOR SOME LOCATIONS THIS MAY BE A
MORNING HIGH.
TUESDAY NIGHT AND WEDNESDAY...THE FORECAST AREA IS PROGGED TO SIT
UNDER UPPER LEVEL TROUGHING FOR MUCH OF TUESDAY NIGHT...IN THE WAKE
OF THE POTENT SHORTWAVE PUSHING EAST OF THE AREA DURING THE EVENING.
NORTHERLY LOW LEVEL FLOW UNDER THE UPPER TROUGH WILL HELP DRIVE
850MB TEMPS FURTHER DOWN...REACHING -4 TO -7C BY 12Z WEDNESDAY.
ACCOMPANYING THE COLDER AIR SHOULD BE A LOW STRATUS DECK...
PARTICULARLY ACROSS WISCONSIN. SO AFTER PERHAPS A BRIEF PERIOD OF
CLEARING IN THE EVENING IN THE WAKE OF THE PRECIPITATION...EXPECT
CLOUDS TO INCREASE. THE COMBINATION OF THESE CLOUDS AND A DECENT
NORTHERLY BREEZE WILL HELP TO KEEP TEMPERATURES FROM BOTTOMING OUT
TO MUCH. HAVE LEANED TOWARDS THE WARMER SIDE OF GUIDANCE AS A RESULT
WITH LOWS IN THE UPPER 20S TO LOWER 30S. THIS STRATUS DECK WILL
DISSIPATE ON WEDNESDAY AS A SURFACE HIGH PRESSURE RIDGE AXIS SLIDES
EAST ACROSS THE AREA. IN FACT...BY 00Z THURSDAY...STRENGTHENING
SOUTHWEST BREEZES ARE EXPECTED AHEAD OF YET ANOTHER POTENT SHORTWAVE
DROPPING DOWN INTO SOUTH CENTRAL CANADA. THESE BREEZES WILL HELP
ADVECT WARMER AIR INTO THE AREA...WITH 850MB TEMPS CLIMBING TO 0 TO
-3C BY 00Z. PLENTY OF SUN AND DRY AIR SHOULD ALLOW FOR PLENTY OF
MIXING...BUT GIVEN THE COOL 850MB TEMPS...AT BEST HIGHS MAY REACH
THE MID 50S AND THAT IS IN FAR SOUTHWESTERN PORTIONS OF THE FORECAST
AREA WHERE THE WARMEST AIR COMES IN LATE.
WEDNESDAY NIGHT AND THURSDAY...THE NEXT POTENT SHORTWAVE THAT
DROPPED DOWN INTO SOUTH CENTRAL CANADA ON WEDNESDAY IS FORECAST TO
HEAD TO THE EAST...VERSUS DIG DOWN TOWARDS THE FORECAST AREA LIKE
THE PAST COUPLE HAVE DONE. AS SUCH...ALL FORCING AND EXPECTED
PRECIPITATION WITH IT WILL STAY WELL NORTH OF THE FORECAST AREA.
HOWEVER...A COLD FRONT IS STILL SLATED TO COME THROUGH. SOME TIMING
DIFFERENCES ON THE SPEED...WITH THE 08.12Z NAM THE SLOWEST NOT
SHOWING FULL PASSAGE UNTIL THURSDAY EVENING WHILE THE 08.12Z
GFS/ECMWF/CANADIAN/UKMET SUGGESTING MAINLY DURING THURSDAY MORNING.
WILL FOLLOW THE MAJORITY GROUP AT THIS TIME AND CONSIDER THE NAM AN
OUTLIER. NO MATTER WHAT MODEL FOLLOWED...IN THE COLD FRONT
WAKE...YET ANOTHER COLD CANADIAN HIGH PRESSURE AREA IS PROGGED TO
DROP DOWN INTO NORTH DAKOTA. AS SUCH...AFTER 850MB TEMPS WARM UP TO
A CONSENSUS 4-8C AT 12Z THURSDAY AHEAD OF THE FRONT...THEY FALL BACK
DOWN TO 0 TO -4C. THIS COLD ADVECTION MAY BE ENOUGH TO PROVIDE A
LITTLE FALL TO TEMPERATURES IN THE AFTERNOON. REGARDING
TEMPERATURES...LEANED CLOSER TO A BLEND OF GUIDANCE FROM THE
MAJORITY GROUP...YIELDING LOWS IN THE MID 30S TO LOW 40S AND HIGHS
IN THE 50S TO LOWER 60S. WARMEST READINGS ON THURSDAY EXPECTED IN
THE FAR SOUTHEAST WITH THE LONGEST PERIOD AHEAD OF THE FRONT AND
POTENTIAL FOR MOST SUN.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
235 PM CDT MON OCT 8 2012
MAIN FORECAST CONCERN IS ON THE EXPECTED WIDESPREAD RAINFALL
CENTERED AROUND SATURDAY
08.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT
AMONGST EACH OTHER AND PAST RUNS SHOWING A PATTERN CHANGE HERE LATE
THIS WEEK. CURRENT UPPER LOW OFF THE COAST OF CALIFORNIA...WHICH
WILL BE DROPPING INTO THE DESERT SOUTHWEST BY FRIDAY MORNING...
MODELS PROG TO LIFT INTO NEBRASKA AND KANSAS ON SATURDAY. A LOW
PRESSURE SYSTEM DEEPENS AHEAD OF THIS UPPER LOW...RESULTING IN
STRONG LOW LEVEL MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO
NORTHWARD INTO THE FORECAST AREA. SO AFTER WHAT WILL BE A DRY AND
COOL THURSDAY NIGHT AND FRIDAY ASSOCIATED WITH CANADIAN HIGH
PRESSURE MOVING ACROSS...EXPECT WARMING WITH PRECIPITATION
EVENTUALLY SPREADING IN FRIDAY NIGHT AND SATURDAY. SATURDAY STILL
LOOKS TO BE THE BEST DAY FOR PRECIPITATION WITH EXPECTED COMBINATION
OF ISENTROPIC LIFT...UPPER JET FORCING AND DPVA. SOME DIFFERENCES DO
EXIST ON SATURDAY AND PARTICULARLY SATURDAY NIGHT AND SUNDAY
REGARDING THE TRACK OF THE UPPER AND SURFACE LOWS. THE 08.12Z
CANADIAN AND A FEW OF THE GFS ENSEMBLE MEMBERS HOLD THE MAJORITY OF
THE SYSTEM BACK OVER THE CENTRAL PLAINS...WHEREAS MOST OTHER MODELS
CONTINUE THE IDEA OF THE PAST FEW DAYS OF EJECTING IT UP TOWARDS THE
GREAT LAKES. HOWEVER...THERE HAS BEEN A TREND IN THE LATTER GROUP TO
ALSO LIFT THE SYSTEM MORE TO THE NORTHWEST. AS A RESULT...FOR LATE
SATURDAY AND SATURDAY EVENING...OUR WHOLE FORECAST AREA ENDS UP IN
THE WARM SECTOR. ALTHOUGH 0-6KM SHEAR IS PLENTIFUL AHEAD OF THE COLD
FRONT...NO FEAR OF SEVERE CONVECTION AS THE 0-3KM MUCAPE FOR
SATURDAY AND SATURDAY NIGHT IS GENERALLY LESS THAN 500 J/KG. FOR THE
FORECAST...HAVE LEANED TOWARDS THE LATTER GROUP...BUT EITHER
SCENARIO YIELDS WIDESPREAD RAINFALL FOR THE FORECAST AREA SATURDAY
INTO MUCH OF SATURDAY NIGHT. THUNDER CHANCES REMAIN NECESSARY DUE TO
THE EXPECTED MUCAPE. EXACT QPF AMOUNTS UNCERTAIN...ESPECIALLY WITH
THE TREND OF THE SYSTEM NOW MORE THE NORTHWEST WHICH WOULD LIKELY
BE LESS THAN IF THE SYSTEM WAS GOING SLIGHTLY TO OUR SOUTH.
IN THE WAKE OF THE UPPER LOW...FORECAST BECOMES A LITTLE MORE
UNCERTAIN FOR SUNDAY INTO MONDAY. PATTERN FROM THE EAST PACIFIC
ACROSS NORTH AMERICA APPEARS TO HAVE FAST FLOW ASSOCIATED WITH IT.
THERE ARE SUGGESTIONS BY THE 08.12Z GFS AND 08.00Z ECMWF OF A
SHORTWAVE TROUGH COMING OUT OF THE PACIFIC NORTHWEST ON SATURDAY
WHICH DIGS INTO THE CENTRAL PLAINS ON MONDAY. GFS ENSEMBLES SHOW A
LOT OF SPREAD...THOUGH...WITH SOME NOT HAVING THIS TROUGH AT ALL AND
ACTUALLY SHOWING A RIDGE. NEW 08.12Z ECMWF KEEPS THE SHORTWAVE
MOVING EAST WITH HINTS OF RIDGING COMING AT THE FORECAST AREA LATE
MONDAY. AS SUCH...HAVE FOLLOWED A CONSENSUS APPROACH FOR THE SUNDAY
THROUGH MONDAY FORECAST. NET RESULT IS TO HAVE SOME LOW
PRECIPITATION CHANCES ON SUNDAY WITH ANY LINGERING PRECIPITATION
FROM THE UPPER LOW...THEN SOME LOW PRECIPITATION CHANCES ON
MONDAY WITH THE POTENTIAL OF THE SHORTWAVE TROUGH DROPPING IN.
TEMPERATURES AT LEAST LOOK CLOSER TO NORMAL THANKS TO THE PACIFIC
FLOW OF AIR.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1150 PM CDT MON OCT 8 2012
A BAND OF SPRINKLES AND LIGHT RAIN WERE FOUND ACROSS SOUTHEAST
MINNESOTA AND INTO PORTIONS OF WESTERN WISCONSIN LATE THIS
EVENING. CEILINGS REMAINED IN THE VFR CATEGORY WITH BASES BETWEEN
050-070K FEET. THIS ALL AHEAD OF THE SURFACE TROUGH NOW MAKING ITS
WAY INTO SOUTHEAST MINNESOTA. BUFKIT SOUNDINGS INDICATE LOW LAYERS
TO SATURATE THROUGH THE OVERNIGHT HOURS AND DO EXPECT MVFR
CEILINGS TO DEVELOP AT BOTH TAF SITES BETWEEN 12Z-14Z. MAIN
SHORTWAVE DROPS THROUGH THE FLOW TUESDAY PUSHING THE SURFACE
TROUGH THROUGH THE AREA. TIME HEIGHT CROSS SECTIONS SHOW RATHER
DEEP FRONTOGENETIC FORCING AND WOULD EXPECT THE PERIODS OF RAIN TO
CONTINUE INTO THE AFTERNOON HOURS. TROUGH LOOKS TO CLEAR THE AREA
LATER IN THE AFTERNOON WITH SOME DRIER AIR WORKING IN. HOWEVER...A
BAND OF STRATUS MAY AFFECT THE KLSE TAF SITES IN ITS WAKE...BUT
THE NAM RELATIVE HUMIDITY PROGS SHOWS IT JUST BRUSHING KRST. THUS
WILL SCATTERED OUT THE CLOUDS AT KRST...BUT KEEP A BROKEN VFR
CEILING AT KLSE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
702 PM CDT MON OCT 8 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JLR
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
936 AM EDT Tue Oct 9 2012
.NEAR TERM...
[Rest of Today] The main issue for today is how long it will take
for the low clouds to break up. So far, they have been expanding
westward through the mid-morning hours with low level northeasterly
flow and now cover the entire forecast area. Looking at the 12z KTAE
sounding, the moisture appears rather shallow overall, but there
is a clear inversion up to around 2500 ft. The 11z RAP viewed in
BUFKIT does not break the inversion until the mid-afternoon hours
around Tallahassee, and it holds low clouds in around Valdosta for
most of the day. Currently, we expect clouds to break from west to
east during the day, but they may hold until the afternoon hours
in areas around Tallahassee and for most of the day in areas
around Valdosta. The previous forecast was already showing a
similar scenario, so only minor adjustments were made to the sky
grids. In terms of temperatures, the current high temperature
forecast is on the low side of guidance given all of the cloud
cover.
&&
.AVIATION...
[Through 12z Wednesday] IFR cigs dominate the area this morning with
a surface inversion in place. These cigs are expected to be slow to
dissipate and will likely linger into the afternoon hours over most
areas.
&&
.PREV DISCUSSION 634 AM EDT Tue Oct 9 2012
.SHORT TERM...
[Tonight through Thursday] The broad trough aloft will keep
afternoon temperatures near or slightly below average through
Thursday. Overnight temperatures will remain about 5 degrees below
average through the period. At the surface, dry northerly flow
provided by high pressure will keep rain out of the forecast. It
appears as though benign weather will continue for several days.
.LONG TERM...
[Thursday night through next Tuesday] The latest GFS & ECMWF
forecast ridging at 500 mb over the Southeast U.S. through
Saturday, followed by a slight fall in the heights into early next
week as trough (currently off the CA coast) translates quickly
northeastward over the Ohio Valley. An area of high pressure
centered to our northeast will provide our forecast area with east
to northeast winds. Both global models forecast the airmass to be
quite dry, though some increase in boundary layer moisture is
likely over the weekend and next week as the boundary layer
becomes modified by its increasing trajectory over the western
Atlantic. Rain chances will be near climo, which this time of year
(typically our driest period) is less than 15%. Temperatures will
be a little above climo, especially during the daytime, with highs
in the generally in the mid 80s (climo is lower 80s). Lows will
start off (Friday & Saturday) in the 50s, then warm into the 60s
Sunday through next Tuesday. Of course, highs will be slightly
cooler and lows slightly warmer than this at the beaches.
&&
.MARINE...
Winds will continue subsiding through the day today as the calm
center of high pressure moves nearer to the Gulf. By Thursday, a
reinforcing area of high pressure will move into the Gulf,
increasing winds and seas through the weekend. Cautionary winds
are expected for at least a brief period of time over the weekend.
&&
.FIRE WEATHER...
With a drier airmass moving into the region, a brief period of
locally "critical" low RH levels is possible Wednesday afternoon,
but it`s probably too marginal for any sort of Fire Weather Watch at
this time. A slightly longer period of low RH is possible Thursday
afternoon, but it`s too early to tell if other factors (such as ERC
and dispersion) will warrant any watches or warnings. GA & AL will
probably not be quite dry enough for Red Flag conditions on these
days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 78 56 85 57 83 / 0 0 0 0 0
Panama City 79 61 82 62 81 / 0 0 0 0 0
Dothan 77 53 83 53 80 / 0 0 0 0 0
Albany 75 54 83 53 80 / 0 0 0 0 0
Valdosta 71 55 84 55 81 / 0 0 0 0 0
Cross City 78 58 86 57 84 / 0 0 0 0 0
Apalachicola 80 61 82 63 81 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Near Term/Aviation...DVD
Short Term/Marine...Harrigan
Long Term/Fire Wx...Fournier
AREA FORECAST DISCUSSION
NWS GOODLAND KS
529 AM MDT TUE OCT 9 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 401 AM MDT TUE OCT 9 2012
FORECAST CONCERNS WILL BE WINDS TODAY AND WEDNESDAY...HOW COOL TO
MAKE TODAY...HOW MUCH TO WARM UP THE NEXT TWO DAYS...AND CHANCE OF
PRECIPITATION LATE IN THE SHORT TERM. SATELLITE CONTINUING TO SHOW AN
AMPLIFIED AND BLOCKY FLOW FROM THE PACIFIC INTO EASTERN NORTH
AMERICA. UPPER LOW NEAR HAS MOVED CLOSER TO THE COAST BUT HAS BEGUN
TO TAKE A MORE SOUTHWARD COURSE. STRONG SYSTEM DIGGING INTO THE NORTH
CENTRAL PORTION OF THE COUNTRY IS PUSHING A COLD FRONT THROUGH THE
AREA AT THIS TIME.
AT JET LEVEL...MODELS WERE CLOSE WITH THE NAM DOING A LITTLE BETTER
THAN THE REMAINING OUTPUT. AT MID LEVELS...MODELS TENDED TO HAVE THE
FEATURES/HEIGHT FIELD TOO FAR SOUTH AND WEST. OVERALL THE CANADIAN...
GFS...AND UKMET WERE DOING THE BEST. HOWEVER...THE NAM DID BETTER ON
THE NORTH CENTRAL SYSTEM. THE MODELS WERE NOT QUITE FAST ENOUGH
WITH THE FRONT. THE HRRR AND RUC WERE DOING THE BEST FOLLOWED BY THE
NAM ON THAT AND OVERALL. ON THE LOW LEVEL THERMAL FIELD THE MODELS
OVERALL WERE CLOSE. HOWEVER...THEY TENDED TO NOT HAVE THE COLD AIR
TO OUR NORTH FAR ENOUGH SOUTH AND WEST. IN THIS AREA THE CANADIAN
AND THE UKMET WERE DOING THE BEST.
TODAY/TONIGHT...AFTER SPEEDING UP THE FRONT THE MODELS HAVE NOW
SLOWED THE FRONT DOWN. LOOKS LIKE IT WILL BE THROUGH THE NORTHWEST
HALF OF THE AREA BY 12Z AND THROUGH ALL THE AREA BY 15Z OR SO.
WINDS LOOK TO STAY UNDER WIND ADVISORY CRITERIA. THE TIGHTEST
GRADIENT AND 3 HOUR PRESSURE RISES ARE DONE BY 15Z AND THEN THEY
START STEADILY DECREASING. BY THE TIME THE SUN COMES UP AND STARTS
THE HEATING...WHICH MAY BE LIMITED BY CLOUD COVER...THOSE
PARAMETERS WILL HAVE BEGUN THIS DECREASE.
THE MODELS ALSO LOOK LIKE THEY HAVE BACK OFF A LITTLE ON THE STRATUS
BEHIND IT. SOME OTHER MID AND HIGH LEVEL CLOUDS WILL MOVE THROUGH AS
WELL DUE TO THE SHORTWAVE TROUGH AND A RIGHT REAR QUADRANT OF THE
JET MOVES FROM NORTH TO SOUTH ACROSS THE AREA THIS MORNING. AT THE
VERY LEAST THIS IS GOING TO PRODUCE THICK CLOUD COVER DURING THIS
TIME. SUBSIDENCE AND CLEARING SHOULD OCCUR BEGINNING AT 18Z. MODELS
HAVE BEEN TRENDING COOLER WITH THE TEMPERATURES AND FOLLOWED THAT
TREND IN THE GRIDS.
VERY LIGHT WINDS AND LOW DEWPOINTS WITH LITTLE IF ANY CLOUD COVER
TONIGHT. THE BEST RADIATIONAL CONDITIONS OCCUR OVER THE NORTHEAST
AND EASTERN COUNTIES AND LOWERED OVERNIGHT LOWS AS A RESULT.
WEDNESDAY/WEDNESDAY NIGHT...SURFACE RIDGE MOVES OFF AS LEE TROUGH
DEVELOPS. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS INCREASE BY
18Z WHICH SHOULD LEAD TO AT LEAST BREEZY AND POSSIBLY WINDY
CONDITIONS DEVELOPING. HIGHER CLOUDS INCREASE DURING THE AFTERNOON IN
THE WEST. MODELS BEGIN DIFFERING HERE ON THE AMOUNT OF WARMUP. WILL
HAVE A COLD START...ESPECIALLY EAST. MODELS HAVE BEEN REALLY ALL
OVER THE PLACE RECENTLY. USING THE 2 METER TEMPERATURES THAT HAVE
BEEN DOING THE BEST AND RECENT 850 MB TEMPERATURE BIASES LED TO ONLY
A SLIGHT ADJUSTMENT TO THE CURRENT FORECAST.
RIGHT REAR QUADRANT OF THE JET MOVES SLOWLY NORTH TO SOUTH ACROSS
THE AREA DURING THE NIGHT. THIS WILL INCREASE CLOUDS PLUS LOW LEVEL
WARM AIR ADVECTION INCREASES THROUGH THE NIGHT. SO WILL BE MUCH
WARMER THAN IT HAS RECENTLY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OVER OR NEAR
THE NORTHERN PORTION OF THE AREA THROUGH THE DAY. UPPER RIDGE
BUILDS TO OUR WEST IN ADVANCE OF UPPER LOW IN THE DESERT SOUTHWEST.
MODELS HAVE SLOWED IN THEIR PROGRESSION OF THIS FEATURE. THIS HAS
ALLOWED A WEST TO WEST NORTHWEST FLOW TO REMAIN A LITTLE LONGER
OVER THE AREA. SO WILL PROBABLY HAVE A LITTLE MORE CLOUD COVER...
ESPECIALLY IN THE NORTH.
BUT WHAT IS MORE IMPORTANT...THIS IS ALLOWING A WEAK SHORTWAVE
TROUGH IN THE NORTH CENTRAL PORTION OF THE COUNTRY TO PUSH A
BACKDOOR COLD FRONT THROUGH THE AREA. MODELS DO SHOW THIS IN A
SIMILAR FASHION BUT DIFFER DRAMATICALLY ON HOW MUCH TO COOL OFF THE
TEMPERATURES. THERE IS A 10 TO 15 DEGREE DIFFERENCE. HEIGHTS RISE
OVER THE PREVIOUS DAY WITH SIMILAR MID LEVEL TEMPERATURES. THE NAM
NWP AND 2 METER IS BY FAR THE WARMEST WITH THE SREF AND UKMET NEXT IN
LINE. THE GFS AND ECMWF FOLLOWED BY THE CANADIAN ARE THE COOLEST.
WHAT ENDED UP DOING WAS SPLITTING THE DIFFERENCE BETWEEN THE
EXTREMES. HOWEVER...COULD SEE EITHER EXTREME OCCURRING.
AGAIN THE MODELS DIFFER ON HOW FAR SOUTH TO TAKE THE FRONT WHICH
WILL AFFECT PRECIPITATION CHANCES DURING THE NIGHT. AGAIN MODELS ARE
SPLIT NEARLY EVENLY ON THE DIFFERENT SOLUTIONS. USUALLY IN THESE
SITUATIONS THE MODEL WITH BETTER TERRAIN ENDS UP HAVING A BETTER
DEPICTION OF THE FRONT. CONSIDERING THE SYNOPTIC PATTERN BELIEVE THE
FARTHER NORTH SOLUTIONS OF WHERE THE FRONT STALLS OUT ARE THE BEST.
THIS ENDS UP BEING THE NAM...UKMET AND CANADIAN. THE FRONT STALLS
OVER SOUTHEAST COLORADO AND SOUTHWEST KANSAS EARLY AND THEN MOVES
NORTH OVERNIGHT.
EVEN THOUGH THE MODELS ARE SLOWER THEY SHOOT OUT A SHORTWAVE INTO
THE AREA AFTER 06Z. ALSO A STRONGER RIGHT REAR QUADRANT
DEVELOPS/MOVES OVER THE AREA...ESPECIALLY AFTER 06Z. ELEVATED CAPE
DEVELOPS OVER THE AREA...ALTHOUGH THEY DIFFER HOW MUCH AND HOW FAR
NORTH. THERE IS ALSO LIMITED ELEVATED CINH. STRONG ISENTROPIC LIFT
DEVELOPS ON THE 300 SURFACE. SATURATED PRESSURE DEFICITS ALSO
DRAMATICALLY DECREASE AS WELL. THE 06Z NAM CAME IN EVEN MORE
FAVORABLE THAN THE 00Z. ALL THIS PLUS SREF AND GEFS PROBABILITIES
SUPPORT HAVING SLIGHT CHANCE TO LOW CHANCE POPS IN OUR SOUTHERN
PORTION AFTER 06Z.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 401 AM MDT TUE OCT 9 2012
RELATIVELY LARGE EARLY SEASON CUTOFF LOW WILL MOVE ACROSS SOUTHEAST
UTAH AND THEN OVER THE CENTRAL ROCKIES INTO THE NEBRASKA PANHANDLE
BY SATURDAY. CYCLOGENESIS WILL INCREASE AS THIS SYSTEM MOVES OUT
ONTO THE PLAINS. INSTABILITY AXIS WILL BE POSITIONED ACROSS THE
COLORADO/KANSAS BORDER AND EXTENDING SOUTH ACROSS TEXAS AND EASTWARD
ACROSS MUCH OF THE REST OF THE STATE. MODELS DIFFER FROM YESTERDAY
IN THAT BOTH THE EC AND THE GFS TAKE THE LOW THROUGH EASTERN
NEBRASKA PANHANDLE AND INTO SOUTHERN MINNESOTA. COMBINED WITH
THIS...A 250 MB JET STREAK WILL BE IN PLACE ACROSS NEW MEXICO AND
THEN UP THROUGH WESTERN KANSAS. AT THE SURFACE...LEE TROUGH ACROSS
EASTERN COLORADO WILL QUICKLY DEEPEN AS COLD FRONT BEGINS TO MOVE
THROUGH THE REGION. CHANCES FOR PRECIPITATION STILL LOOK TO BE ON
TRACK WITH THIS SYSTEM...WITH A CHANCE THAT SOME OF THESE STORMS MAY
BE SEVERE. MUCH OF THE SEVERE ACTIVITY APPEARS TO INITIATE WELL EAST
OF THE CWA AS BETTER OVERALL PROFILE SETS UP ACROSS IOWA AND
MISSOURI. SYSTEM DOES NOT APPEAR TO USHER IN TOO MUCH COLD AIR BUT
DOES TRY TO DRY SLOT THE AREA BY SATURDAY MORNING. IF THIS REIGNS
TRUE...SECTIONS OF THE AREA MAY SEE LITTLE TO NO PRECIPITATION.
SUBSIDENCE WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM AHEAD OF
ANOTHER COLD FRONT THAT WILL MOVE ACROSS THE AREA BY EARLY NEXT
WEEK. A SHORTWAVE TROUGH WILL ALSO MOVE ACROSS THE NORTHERN PLAINS
DURING THIS TIME...WITH PRECIPITATION CHANGES REMAINING WELL NORTH
OF THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 525 AM MDT TUE OCT 9 2012
COLD FRONT IS MOVING THROUGH THE AREA AT THIS TIME. WINDS WILL
RAPIDLY INCREASE THIS MORNING WITH SPEEDS OF NEAR 23 KNOTS GUSTING
TO AROUND 33 KNOTS. LATE THIS MORNING INTO EARLY THIS AFTERNOON
THESE WINDS WILL GRADUALLY DECREASE BEFORE BECOMING LIGHT. JUST
BEHIND THE FRONT MVFR CEILINGS ARE EXPECTED TO DEVELOP AND CONTINUE
INTO EARLY AFTERNOON BEFORE RISING JUST ABOVE MVFR. SKIES WILL
CLEAR LATE THIS AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...PMM
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
401 AM MDT TUE OCT 9 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 401 AM MDT TUE OCT 9 2012
FORECAST CONCERNS WILL BE WINDS TODAY AND WEDNESDAY...HOW COOL TO
MAKE TODAY...HOW MUCH TO WARM UP THE NEXT TWO DAYS...AND CHANCE OF
PRECIPITATION LATE IN THE SHORT TERM. SATELLITE CONTINUING TO SHOW AN
AMPLIFIED AND BLOCKY FLOW FROM THE PACIFIC INTO EASTERN NORTH
AMERICA. UPPER LOW NEAR HAS MOVED CLOSER TO THE COAST BUT HAS BEGUN
TO TAKE A MORE SOUTHWARD COURSE. STRONG SYSTEM DIGGING INTO THE NORTH
CENTRAL PORTION OF THE COUNTRY IS PUSHING A COLD FRONT THROUGH THE
AREA AT THIS TIME.
AT JET LEVEL...MODELS WERE CLOSE WITH THE NAM DOING A LITTLE BETTER
THAN THE REMAINING OUTPUT. AT MID LEVELS...MODELS TENDED TO HAVE THE
FEATURES/HEIGHT FIELD TOO FAR SOUTH AND WEST. OVERALL THE CANADIAN...
GFS...AND UKMET WERE DOING THE BEST. HOWEVER...THE NAM DID BETTER ON
THE NORTH CENTRAL SYSTEM. THE MODELS WERE NOT QUITE FAST ENOUGH
WITH THE FRONT. THE HRRR AND RUC WERE DOING THE BEST FOLLOWED BY THE
NAM ON THAT AND OVERALL. ON THE LOW LEVEL THERMAL FIELD THE MODELS
OVERALL WERE CLOSE. HOWEVER...THEY TENDED TO NOT HAVE THE COLD AIR
TO OUR NORTH FAR ENOUGH SOUTH AND WEST. IN THIS AREA THE CANADIAN
AND THE UKMET WERE DOING THE BEST.
TODAY/TONIGHT...AFTER SPEEDING UP THE FRONT THE MODELS HAVE NOW
SLOWED THE FRONT DOWN. LOOKS LIKE IT WILL BE THROUGH THE NORTHWEST
HALF OF THE AREA BY 12Z AND THROUGH ALL THE AREA BY 15Z OR SO.
WINDS LOOK TO STAY UNDER WIND ADVISORY CRITERIA. THE TIGHTEST
GRADIENT AND 3 HOUR PRESSURE RISES ARE DONE BY 15Z AND THEN THEY
START STEADILY DECREASING. BY THE TIME THE SUN COMES UP AND STARTS
THE HEATING...WHICH MAY BE LIMITED BY CLOUD COVER...THOSE
PARAMETERS WILL HAVE BEGUN THIS DECREASE.
THE MODELS ALSO LOOK LIKE THEY HAVE BACK OFF A LITTLE ON THE STRATUS
BEHIND IT. SOME OTHER MID AND HIGH LEVEL CLOUDS WILL MOVE THROUGH AS
WELL DUE TO THE SHORTWAVE TROUGH AND A RIGHT REAR QUADRANT OF THE
JET MOVES FROM NORTH TO SOUTH ACROSS THE AREA THIS MORNING. AT THE
VERY LEAST THIS IS GOING TO PRODUCE THICK CLOUD COVER DURING THIS
TIME. SUBSIDENCE AND CLEARING SHOULD OCCUR BEGINNING AT 18Z. MODELS
HAVE BEEN TRENDING COOLER WITH THE TEMPERATURES AND FOLLOWED THAT
TREND IN THE GRIDS.
VERY LIGHT WINDS AND LOW DEWPOINTS WITH LITTLE IF ANY CLOUD COVER
TONIGHT. THE BEST RADIATIONAL CONDITIONS OCCUR OVER THE NORTHEAST
AND EASTERN COUNTIES AND LOWERED OVERNIGHT LOWS AS A RESULT.
WEDNESDAY/WEDNESDAY NIGHT...SURFACE RIDGE MOVES OFF AS LEE TROUGH
DEVELOPS. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS INCREASE BY
18Z WHICH SHOULD LEAD TO AT LEAST BREEZY AND POSSIBLY WINDY
CONDITIONS DEVELOPING. HIGHER CLOUDS INCREASE DURING THE AFTERNOON IN
THE WEST. MODELS BEGIN DIFFERING HERE ON THE AMOUNT OF WARMUP. WILL
HAVE A COLD START...ESPECIALLY EAST. MODELS HAVE BEEN REALLY ALL
OVER THE PLACE RECENTLY. USING THE 2 METER TEMPERATURES THAT HAVE
BEEN DOING THE BEST AND RECENT 850 MB TEMPERATURE BIASES LED TO ONLY
A SLIGHT ADJUSTMENT TO THE CURRENT FORECAST.
RIGHT REAR QUADRANT OF THE JET MOVES SLOWLY NORTH TO SOUTH ACROSS
THE AREA DURING THE NIGHT. THIS WILL INCREASE CLOUDS PLUS LOW LEVEL
WARM AIR ADVECTION INCREASES THROUGH THE NIGHT. SO WILL BE MUCH
WARMER THAN IT HAS RECENTLY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OVER OR NEAR
THE NORTHERN PORTION OF THE AREA THROUGH THE DAY. UPPER RIDGE
BUILDS TO OUR WEST IN ADVANCE OF UPPER LOW IN THE DESERT SOUTHWEST.
MODELS HAVE SLOWED IN THEIR PROGRESSION OF THIS FEATURE. THIS HAS
ALLOWED A WEST TO WEST NORTHWEST FLOW TO REMAIN A LITTLE LONGER
OVER THE AREA. SO WILL PROBABLY HAVE A LITTLE MORE CLOUD COVER...
ESPECIALLY IN THE NORTH.
BUT WHAT IS MORE IMPORTANT...THIS IS ALLOWING A WEAK SHORTWAVE
TROUGH IN THE NORTH CENTRAL PORTION OF THE COUNTRY TO PUSH A
BACKDOOR COLD FRONT THROUGH THE AREA. MODELS DO SHOW THIS IN A
SIMILAR FASHION BUT DIFFER DRAMATICALLY ON HOW MUCH TO COOL OFF THE
TEMPERATURES. THERE IS A 10 TO 15 DEGREE DIFFERENCE. HEIGHTS RISE
OVER THE PREVIOUS DAY WITH SIMILAR MID LEVEL TEMPERATURES. THE NAM
NWP AND 2 METER IS BY FAR THE WARMEST WITH THE SREF AND UKMET NEXT IN
LINE. THE GFS AND ECMWF FOLLOWED BY THE CANADIAN ARE THE COOLEST.
WHAT ENDED UP DOING WAS SPLITTING THE DIFFERENCE BETWEEN THE
EXTREMES. HOWEVER...COULD SEE EITHER EXTREME OCCURRING.
AGAIN THE MODELS DIFFER ON HOW FAR SOUTH TO TAKE THE FRONT WHICH
WILL AFFECT PRECIPITATION CHANCES DURING THE NIGHT. AGAIN MODELS ARE
SPLIT NEARLY EVENLY ON THE DIFFERENT SOLUTIONS. USUALLY IN THESE
SITUATIONS THE MODEL WITH BETTER TERRAIN ENDS UP HAVING A BETTER
DEPICTION OF THE FRONT. CONSIDERING THE SYNOPTIC PATTERN BELIEVE THE
FARTHER NORTH SOLUTIONS OF WHERE THE FRONT STALLS OUT ARE THE BEST.
THIS ENDS UP BEING THE NAM...UKMET AND CANADIAN. THE FRONT STALLS
OVER SOUTHEAST COLORADO AND SOUTHWEST KANSAS EARLY AND THEN MOVES
NORTH OVERNIGHT.
EVEN THOUGH THE MODELS ARE SLOWER THEY SHOOT OUT A SHORTWAVE INTO
THE AREA AFTER 06Z. ALSO A STRONGER RIGHT REAR QUADRANT
DEVELOPS/MOVES OVER THE AREA...ESPECIALLY AFTER 06Z. ELEVATED CAPE
DEVELOPS OVER THE AREA...ALTHOUGH THEY DIFFER HOW MUCH AND HOW FAR
NORTH. THERE IS ALSO LIMITED ELEVATED CINH. STRONG ISENTROPIC LIFT
DEVELOPS ON THE 300 SURFACE. SATURATED PRESSURE DEFICITS ALSO
DRAMATICALLY DECREASE AS WELL. THE 06Z NAM CAME IN EVEN MORE
FAVORABLE THAN THE 00Z. ALL THIS PLUS SREF AND GEFS PROBABILITIES
SUPPORT HAVING SLIGHT CHANCE TO LOW CHANCE POPS IN OUR SOUTHERN
PORTION AFTER 06Z.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 401 AM MDT TUE OCT 9 2012
RELATIVELY LARGE EARLY SEASON CUTOFF LOW WILL MOVE ACROSS SOUTHEAST
UTAH AND THEN OVER THE CENTRAL ROCKIES INTO THE NEBRASKA PANHANDLE
BY SATURDAY. CYCLOGENESIS WILL INCREASE AS THIS SYSTEM MOVES OUT
ONTO THE PLAINS. INSTABILITY AXIS WILL BE POSITIONED ACROSS THE
COLORADO/KANSAS BORDER AND EXTENDING SOUTH ACROSS TEXAS AND EASTWARD
ACROSS MUCH OF THE REST OF THE STATE. MODELS DIFFER FROM YESTERDAY
IN THAT BOTH THE EC AND THE GFS TAKE THE LOW THROUGH EASTERN
NEBRASKA PANHANDLE AND INTO SOUTHERN MINNESOTA. COMBINED WITH
THIS...A 250 MB JET STREAK WILL BE IN PLACE ACROSS NEW MEXICO AND
THEN UP THROUGH WESTERN KANSAS. AT THE SURFACE...LEE TROUGH ACROSS
EASTERN COLORADO WILL QUICKLY DEEPEN AS COLD FRONT BEGINS TO MOVE
THROUGH THE REGION. CHANCES FOR PRECIPITATION STILL LOOK TO BE ON
TRACK WITH THIS SYSTEM...WITH A CHANCE THAT SOME OF THESE STORMS MAY
BE SEVERE. MUCH OF THE SEVERE ACTIVITY APPEARS TO INITIATE WELL EAST
OF THE CWA AS BETTER OVERALL PROFILE SETS UP ACROSS IOWA AND
MISSOURI. SYSTEM DOES NOT APPEAR TO USHER IN TOO MUCH COLD AIR BUT
DOES TRY TO DRY SLOT THE AREA BY SATURDAY MORNING. IF THIS REIGNS
TRUE...SECTIONS OF THE AREA MAY SEE LITTLE TO NO PRECIPITATION.
SUBSIDENCE WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM AHEAD OF
ANOTHER COLD FRONT THAT WILL MOVE ACROSS THE AREA BY EARLY NEXT
WEEK. A SHORTWAVE TROUGH WILL ALSO MOVE ACROSS THE NORTHERN PLAINS
DURING THIS TIME...WITH PRECIPITATION CHANGES REMAINING WELL NORTH
OF THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1146 PM MDT MON OCT 8 2012
MVFR TO VFR CONDITIONS ARE FORECAST FOR BOTH TAF SITES. LATEST
RADAR IMAGERY SHOWS THE COLD FRONT JUST NORTH OF KMCK...ARRIVING
AROUND 7Z WITH A 9Z ARRIVAL AT KGLD. MODELS SHOW AN INCREASE IN
LOW LEVEL MOISTURE DURING THE MORNING BEHIND THE COLD FRONT. MAY
HAVE SOME LOW CLOUDS DEVELOP OVER BOTH SITES AS A RESULT. THE
SKIES SHOULD CLEAR DURING THE AFTERNOON AS DRIER AIR MOVES IN.
OTHERWISE WINDS WILL BE STRONGEST DURING THE MORNING THEN DECLINE
DURING THE AFTERNOON AS THE FRONT MOVES FURTHER SOUTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...PMM
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GRAY ME
946 AM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE
AREA WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT
USHERING IN COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD
OVER NEW ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM
FRONT WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /TODAY/...
10AM UPDATE... HAVE MADE ONLY MINOR ADJUSTMENTS TO TEMPERATURES
TODAY. SOME LOWER STRATUS ARE MOVING INTO THE AREA FROM THE
SOUTHWEST IN ASSOCIATION WITH A SHORTWAVE TROUGH ALOFT AND
OFFSHORE LOW PRESSURE. ONLY A SLIGHT CHANCE OF SHOWERS WITH
THIS... AS SOME ACTIVITY IS SHOWING UP ON REGIONAL RADARS ALREADY.
MUCH OF THIS MAY NOT BE REACHING THE GROUND. BEST CHANCE TO
RECEIVE PRECIPITATION WILL BE ALONG THE COAST.
UPDATE...SOME TWEAKS TO THE GOING FCST TO ACCOUNT FOR LATEST
OBSERVATIONAL TRENDS IN TEMPS AND DEW POINTS. ELY WINDS HAVE
PICKED UP ON THE COAST...AND THAT IS HELPING TO PUSH SOME OF THAT
HIGH MID LVL RH ONSHORE. BLENDED THE PREVIOUS FCST WITH THE LOCAL
WRF MODEL...AS IT HAD A GOOD HANDLE ON LOCATION AND TIMING OF
CLOUD DECK. ALSO SHARPENED THE GRADIENT OF POP FOR THIS AFTN...TO
KEEP ANY SHRA CONFINED TO THE COAST ONLY.
PREVIOUS DISCUSSION...CIRRUS SHIELD ALONG THE COAST AND INTERIOR
HAS ALLOWED TEMPS TO REMAIN IN THE MID 40S UNDERNEATH THE CANOPY.
HOWEVER...ON THE FRINGES AND ACROSS THE NRN MTNS AND VALLEYS
RADIATIONAL COOLING HAS ALLOWED READINGS TO TUMBLE INTO THE 30S
WITH A FEW UPR 20S. HERE AREAS OF GROUND/VALLEY FOG WILL BE
COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORNING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ150>154.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
713 AM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA
WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT USHERING IN
COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM FRONT
WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SOME TWEAKS TO THE GOING FCST TO ACCOUNT FOR LATEST
OBSERVATIONAL TRENDS IN TEMPS AND DEW POINTS. ELY WINDS HAVE
PICKED UP ON THE COAST...AND THAT IS HELPING TO PUSH SOME OF THAT
HIGH MID LVL RH ONSHORE. BLENDED THE PREVIOUS FCST WITH THE LOCAL
WRF MODEL...AS IT HAD A GOOD HANDLE ON LOCATION AND TIMING OF
CLOUD DECK. ALSO SHARPENED THE GRADIENT OF POP FOR THIS AFTN...TO
KEEP ANY SHRA CONFINED TO THE COAST ONLY.
PREVIOUS DISCUSSION...CIRRUS SHIELD ALONG THE COAST AND INTERIOR
HAS ALLOWED TEMPS TO REMAIN IN THE MID 40S UNDERNEATH THE CANOPY.
HOWEVER...ON THE FRINGES AND ACROSS THE NRN MTNS AND VALLEYS
RADIATIONAL COOLING HAS ALLOWED READINGS TO TUMBLE INTO THE 30S
WITH A FEW UPR 20S. HERE AREAS OF GROUND/VALLEY FOG WILL BE
COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORNING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ150>154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
712 AM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA
WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT USHERING IN
COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM FRONT
WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SOME TWEAKS TO THE GOING FCST TO ACCOUNT FOR LATEST
OBSERVATIONAL TRENDS. ELY WINDS HAVE PICKED UP ON THE COAST...AND
THAT IS HELPING TO PUSH SOME OF THAT HIGH MID LVL RH ONSHORE.
BLENDED THE PREVIOUS FCST WITH THE LOCAL WRF MODEL...AS IT HAD A
GOOD HANDLE ON LOCATION AND TIMING OF CLOUD DECK. ALSO SHARPENED
THE GRADIENT OF POP FOR THIS AFTN...TO KEEP ANY SHRA CONFINED TO
THE COAST ONLY.
PREVIOUS DISCUSSION...CIRRUS SHIELD ALONG THE COAST AND INTERIOR
HAS ALLOWED TEMPS TO REMAIN IN THE MID 40S UNDERNEATH THE CANOPY.
HOWEVER...ON THE FRINGES AND ACROSS THE NRN MTNS AND VALLEYS
RADIATIONAL COOLING HAS ALLOWED READINGS TO TUMBLE INTO THE 30S
WITH A FEW UPR 20S. HERE AREAS OF GROUND/VALLEY FOG WILL BE
COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORNING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ150>154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
724 AM EDT TUE OCT 9 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EDT TUE OCT 9 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW MEAN UPR TROF
STILL DOMINATING ERN NAMERICA DOWNSTREAM OF UPR RDG OFF THE W COAST
OF CANADA. TWO DISTURBANCES OF NOTE ARE EMBEDDED IN THIS TROF. THE
FIRST IS CURRENTLY MOVING THRU THE UPR GRT LKS...WITH 999MB SFC LO
OVER ONTARIO. AT 06Z...ATTENDANT COLD FNT IS PUSHING INTO THE WRN
CWA...PRECEDED BY A BAND OF SCT -SHRA STRETCHING FM JUST E OF THE
KEWEENAW SWWD INTO NCENTRAL WI. STRONG S WINDS ARE EVIDENT UNDER THE
SHARPER PRES GRADIENT TO THE E AS 00Z GRB RAOB INDICATED WINDS UP TO
39KTS AS LO AS 2K FT AGL AND UNSTABLE LLVL LAPSE RATES. THE WINDS
ARE STRONGEST AT EXPOSED LOCATIONS NEAR LK MI...WHERE WINDS GUSTED
AS HI AS 45-55 MPH AT SEVERAL SITES YDAY EVNG. WHILE THE DRYNESS OF
THE SUB H8 LYR SHOWN ON THE 00Z GRB RAOB RESTRICTED PCPN COVERAGE/
AMOUNTS OVER MUCH OF THE CWA AHEAD OF THE COLD FNT...MORE SHRA ARE
NOTED OVER THE ERN CWA WHERE THE S WIND UP THE LENGTH OF LK MI
ALLOWED SUFFICIENT MOISTENING TO OVERCOME THIS LLVL DRY AIR. BUT
THIS PCPN IS TENDING TO DRIFT INTO FAR ERN UPR MI AND OUT OF THE MQT
CWA. TO THE W...THERE IS PARTIAL CLRG OVER MUCH OF CENTRAL AND SRN
MN BEHIND THE COLD FROPA AS DRIER AIR SHOWN ON THE 00Z MPX RAOB
ADVECTS TO THE ENE. BUT MORE HI AND MID CLDS ASSOCIATED WITH A
STRONGER SECOND SHRTWV DROPPING SEWD INTO THE NRN PLAINS ARE
SPREADING TO THE E THRU MN AT THE SAME TIME. THE APRCH OF THIS
SHRTWV IS ALSO CAUSING A GREATER COVERAGE OF -SHRA ON THE SRN EDGE
OF THE COLD FNT OVER SE MN/NRN IOWA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE WHETHER TO ALLOW CURRENT
WIND ADVY FOR THE ERN CWA TO EXPIRE AS SCHEDULED AT 09Z AND EVENTUAL
-RA COVERAGE ASSOCIATED WITH STRONGER SECOND SHRTWV NOW DIGGING INTO
THE NRN PLAINS.
EARLY THIS MRNG...AS SHRTWV/SFC LO TO THE N MOVE TO THE NE...COLD
FNT EXTENDING S THRU UPR MI WL SHIFT TO THE E BUT TEND TO SLOW DOWN
AS SECOND SHRTWV DIGGING THRU THE NRN PLAINS DEEPENS THE UPR TROF
AXIS TO THE W AND THE FLOW ALF BACKS TO MORE SW OVER THE GREAT
LAKES. THE BAND OF -SHRA PRECEDING THE FNT WL LIKELY DRY OUT A BIT
WITH BEST FORCING EXITING TO THE NE AND LLVL DRY AIR LINGERING W OF
LIMITING STREAMLINE OFF LK MI. BUT MOISTENING OFF LK MI MIGHT ALLOW
FOR SOME EHNANCEMENT TO THE COVERAGE AGAIN ONCE THE BAND REACHES
THAT AREA. WITH THE CLOSER APRCH OF THE COLD FNT...THE PRES GRADIENT
OVER THE E WL WEAKEN SUFFICIENTLY TO ALLOW THE STRONGER S WINDS TO
DIMINISH BEFORE 12Z. SO PLANNED EXPIRATION OF WIND ADVY AT 09Z SEEMS
TO BE ON TRACK. OVER THE W...DRYING ALF WL BRING DRY WX FOR THE MOST
PART.
TODAY...AS THE UPR TROF AXIS DEEPENS TO THE W IN RESPONSE TO DIGGING
SECOND SHRTWV...EXPECT AREA OF SHRA NOW ON COLD FNT TO THE S TO
EXPAND AND MOVE NE. LATEST MODEL RUNS SHOW CONSIDERABLE SPREAD ON
WHERE AREA OF SHRA WL IMPACT. THE 00Z LOCAL WRF-ARW/CNDN MODELS ARE
FARTHEST W WITH THE TRACK OF THE HEAVIER PCPN...WHILE THE 00Z NAM IS
FARTHEST TO THE E AND IN LINE WITH CURRENT FCST. CONSIDERING THE
TRENDS ON THE INCOMING DRYING TO THE W BEHIND THE COLD FNT AS WELL
AS FCST SHARPEST H85-5 QVECTOR CNVGC OVER THE E THIS AFTN...TEND TO
THINK THE NAM IS ON THE RIGHT TRACK. THE SHARPEST H85-7 FGEN IS ALSO
OVER THE E. ON THE OTHER HAND...SINCE THE FRONTAL SLOPE WL BE RATHER
FLAT...SOME SHARP H7-5 FGEN/H7-3 QVECTOR CVNGC/H4-2 DVGC IS EVIDENT
FARTHER W AND OVER THE WRN CWA. SO EVEN IF THE HEAVIER PCPN DOES
FALL TO THE E...SUSPECT THERE WL BE AT LEAST SOME SCT -SHRA OVER THE
W...WHERE THE HIER DYNAMICS WL HAVE TO OVERCOME MORE LLVL DRYING. AS
THE SHRTWV/DYNAMIC SUPPORT SHIFTS TO THE NE LATER IN THE DAY...
EXPECT THE POPS TO DIMINISH...LATEST OVER THE E. WITH PLENTY OF CLD
COVER AND A GRADUAL INFLUX OF COOLER AIR...EXPECT LTL DIURNAL RISE
IN TEMPS.
TONIGHT...IN THE WAKE OF THE DEPARTING SHRTWV...A CYC NW LLVL FLOW
WL ADVECT A CHILLY CNDN AIRMASS INTO THE UPR LKS. WITH H85 TEMPS
FALLING AS LO AS -7C/-5C OVER WRN/ERN LK SUP BY 12Z /COMPARED WITH
WATER TEMPS OF 7C AT THE WRN BUOY AND 11C AT THE ERN BUOY/...
OVERWATER INSTABILITY WL BECOME SUFFICIENT FOR LK EFFECT -SHRASN TO
IMPACT AREAS FAVORED BY THE LLVL NW FLOW...ESPECIALLY SINCE DEEPER
MSTR WL EXTEND TO THE DGZ. BUMPED POPS UP IN THESE AREAS ABV MODEL
GUIDANCE. WOULD NOT BE SURPRISED TO SEE 1 TO 2 INCHES OF SNOW ACCUM
OVER THE HIER TERRAIN IN AREAS FAVORED BY NW FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR THEME OF INCREASED WIND WITH SYSTEMS ROLLING THROUGH EVERY
COUPLE OF DAYS WILL CONTINUE FOR THE FORESEEABLE FUTURE.
WEDNESDAY...
THE LARGE SCALE TROUGH OVER MUCH OF THE NATION WILL BE CENTERED
ACROSS THE UPPER GREAT LAKES AT 12Z WEDNESDAY...EDGING E THROUGH THE
DAY...WITH NW FLOW RULING THE AREA. WITH NW FLOW AT THE SFC AND
ALOFT...EXPECT COOL AIR TO REMAIN IN PLACE /850MB TEMPS OF -6 TO
-8C/...WITH UPSLOPE LAKE EFFECT SHOWER ACTIVITY. SNOW WILL LIKELY
MIX IN ACROSS W PORTIONS OF THE CWA BEFORE TEMPS WARM TO NEAR 40F
AND WINDS TURN A BIT MORE WESTERLY. ANY ADDITIONAL SNOW WEDNESDAY
SHOULD TOTAL AROUND A HALF AN INCH OR LESS...AS THE INCOMING SFC
RIDGE HELPS TO SCOUR OUT SOME OF THE LOW LEVEL MOISTURE.
WEDNESDAY NIGHT THROUGH FRIDAY...
THE NEXT CLIPPER-LIKE LOW WILL SLIDE IN FROM THE NORTHWEST LATE
WEDNESDAY NIGHT INTO THURSDAY...MOVING DIRECTLY OVER LAKE SUPERIOR
AT 12Z THURSDAY. AFTER 850MB TEMPS JUMPING UP TO AROUND 0C ON
INCREASED SW WINDS...THEY SHOULD AGAIN FALL TO -6 TO -7C THURSDAY
AFTERNOON. LIKE BEFORE...ANOTHER RIDGE OF HIGH PRESSURE WILL PUSH
IN...DRYING US OUT THURSDAY NIGHT AND FRIDAY. THIS TIME THE SFC HIGH
WILL MOVE OVER OR JUST S OF THE AREA /ACROSS WI AND LAKE MI FRIDAY
AFTERNOON/...WITH MUCH LIGHTER WINDS AT LEAST TEMPORARILY.
FRIDAY NIGHT THROUGH MONDAY...
THE HIGH WILL QUICKLY SLIDE TO THE LOWER GREAT LAKES FRIDAY
NIGHT...AS LOW PRESSURE ORGANIZES OFF THE ROCKIES. THE STRENGTHENING
LOW WILL SLIDE IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING
MUCH WARMER AIR ON STRONG SOUTHERLY WINDS...AND THE POTENTIAL FOR
MODERATE TO HEAVY RAIN...BEFORE EXITING NORTHEAST ON SUNDAY. FCST
MODELS HAVE BEEN FAIRLY CONSISTANT ON THE TRACK OF THE LOW OVER
UPPER MI...SO HAVE INCREASED POPS TO 80 PERCENT OR BETTER SATURDAY
AND SATURDAY NIGHT OVER CENTRAL AND E AREAS...AS WELL AS ADDED A
NON-DIURNAL TEMP TREND SATURDAY NIGHT /PARTICULARLY E WITH THE
CONTINUED S WINDS OFF LAKE MI/.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 722 AM EDT TUE OCT 9 2012
DESPITE THE APRCH OF AN UPR DISTURBANCE THAT WL BRING SOME -SHRA
THAT IMPACT SAW THIS AFTN...EXPECT VFR CONDITIONS TO PREDOMINATE
TODAY AT ALL 3 TAF SITES WITH LLVL W-SW FLOW ADVECTING DRY AIR SHOWN
ON THE 00Z MPX RAOB OVER UPR MI. THE PASSAGE OF A COLD FNT
ASSOCIATED WITH THIS UPR DISTURBANCE WL CAUSE A WSHFT TO THE NW
TNGT. AS COLDER AIR PUSHES INTO THE AREA...INCRSG LLVL INSTABILITY
WL RESULT IN GUSTY NW WINDS...ESPECIALLY AT THE MORE EXPOSED CMX
SITE. THE ARRIVAL OF THE COLDER AIR WL ALSO BRING MVFR CIGS/LK
EFFECT -SHRA THAT MIX WITH/CHG TO SN OVERNGT...ESPECIALLY AT IWD/CMX
WITH UPSLOPE WIND COMPONENT. DOWNSLOPE NATURE OF THE FLOW AT SAW WL
LIKELY PREVENT ANY SGNFT PCPN AND MAKE VFR CIGS A GREATER
POSSIBILITY THAN AT IWD/CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND...WITH
ANOTHER SYSTEM SLIDING IN FOR THE WEEKEND. EXITING LOW PRESSURE JUST
NORTH OF LS WILL SWEEP A TROUGH ACROSS CENTRAL AND EASTERN LS
TODAY...WITH A COOLER SECONDARY TROUGH ROTATING THROUGH TONIGHT. THIS
WILL BRING NORTHWESTERLY WINDS BACK TO THE REGION THROUGH EARLY
WEDNESDAY /WITH SOME NW GALE FORCE GUSTS TO 35 KTS WEDNESDAY ACROSS E
LS/. AFTER A QUICK RIDGE PUSHES IN...THE NEXT LOW WILL SLIDE IN FROM
THE NW LATE WEDNESDAY NIGHT INTO THURSDAY /WITH W GUSTS AGAIN OF
30-35KTS THURSDAY INTO THURSDAY EVENING/...BEFORE HIGH PRESSURE MOVES
OVERHEAD WITH TEMPORARILY LIGHTER WINDS FRIDAY. A STRENGTHENING LOW
WILL PUSH IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING STRONGER
SOUTHERLY WINDS BEFORE EXITING NE OF LS ON SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ266-267.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1008 AM EDT TUE OCT 9 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST INTO THE MARITIMES TODAY ALONG WITH
LIGHT SOUTH TO SOUTHEASTERLY WINDS DEVELOPING AND VARIABLE CLOUD
COVER EXPECTED. DRY WEATHER IS EXPECTED. A COLD FRONT WILL SWING
THROUGH THE REGION LATER WEDNESDAY INTO WEDNESDAY EVENING WITH A
RENEWED THREAT OF SHOWERS...WITH ADDITIONAL SHOWERS POSSIBLE
THURSDAY NIGHT WITH YET ANOTHER COLD FRONT. DRY AND CHILLY
WEATHER SETTLES INTO THE REGION FOR FRIDAY INTO EARLY SATURDAY
BEFORE MODERATING TEMPERATURES AND A CHANCE OF SHOWERS RETURN BY
SUNDAY INTO MONDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1010 AM EDT TUESDAY...SFC ANALYSIS SHOWS WEAK RIDGE OF HIGH
PRES ACRS NORTHERN NY INTO CENTRAL/NORTHERN VT THIS MORNING.
MEANWHILE...ANTICYCLONIC FLOW AROUND THIS SYSTEM IS ADVECTING LLVL
MOISTURE/CLOUDS INTO SOUTHERN VT THIS MORNING. LATEST SATL TRENDS
SHOW THESE CLOUDS MOVING INTO CENTRAL VT ATTM...WITH MAINLY CLR
SKIES ACRS NORTHERN VT/NORTHERN NY. WL ADJUST CLOUD COVER GRIDS
BASED ON TRENDS AND TWEAK TEMPS SLIGHTLY COOLER ACRS
RUTLAND/WINDSOR COUNTIES BASED ON MORE CLOUDS. RUC13 925MB TO
700MB RH PROGS SHOWS THIS MOISTURE SLOWLY MOVING NORTHWARD THIS
AFTN...BUT ALSO THINNING THRU TIME. EXPECT PARTLY SUNNY SKIES MOST
OF THE CWA BY THIS AFTN WITH TEMPS IN THE U40S SOUTHERN MTNS TO
NEAR 60 CPV/SLV.
PRIOR DISCO...
1030 HPA SFC HIGH CONTINUES TO PUSH EAST OF THE REGION
INTO THE CANADIAN MARITIMES THIS MORNING WITH MAINLY CLEAR SKIES
AND PATCHY FOG HERE AND THERE. CHALLENGE FOR TODAY WILL BE AREAL
EXTENT/COVERAGE OF LOW TO MID LEVEL STRATUS CLOUDS CURRENTLY
PUSHING SLOWLY NORTH ACROSS THE NRN MID ATLANTIC INTO SRN NEW
ENGLAND. WITH HYSPLIT LOW LEVEL BACK TRAJECTORIES FROM THE
EAST/SOUTHEAST TODAY...FEEL THESE CLOUDS WILL CONTINUE THEIR NORTH
TO NORTHEASTWARD TREK...WITH MANY AREAS FROM THE EASTERN SLOPES OF
THE DACKS EAST ACROSS VT TRENDING PARTLY TO MOSTLY CLOUDY AS THE
MORNING/AFTERNOON WEARS ON. GIVEN FAIRLY SHALLOW MOIST
LAYER...SOME POSSIBILITY THAT AFTERNOON SUN CAN BURN SOME OF THIS
OFF OVER TIME...ESP IN THE CHAMPLAIN VALLEY...BUT WITH MARGINALLY
LOW SUN ANGLE I`M NOT HANGING MY HAT ON IT...ESP ERN VT. FURTHER
WEST MORE SUN EXPECTED AND THIS IS WHERE THE MILDEST TEMPERATURES
WILL OCCUR (L60S). ELSEWHERE VALUES IN THE M-U 50S LOOKS
REASONABLE. NO PCPN IS EXPECTED OUTSIDE SOME PATCHY DRIZZLE
POSSIBLE ABOVE 2 KFT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 356 AM EDT TUESDAY...VARIABLE CLOUD COVER THEN PERSISTS
ACROSS THE REGION TONIGHT AS LOW TO MID LEVEL SOUTHERLY FLOW
SLOWLY INCREASES ACROSS THE REGION IN ADVANCE OF A DIGGING
SHORTWAVE TROUGH SWINGING INTO THE GREAT LAKES. LOW TEMPERATURES
A TAD MILDER GIVEN AT LEAST SOME TURBULENT MIXING PROCESSES JUST
OFF THE DECK...MAINLY 35-40 MTNS AND L-M 40S CHAMPLAIN/ST
LAWRENCE VALLEYS.
CHANGEABLE CONDITIONS TO THEN OCCUR DURING WEDNESDAY INTO
WEDNESDAY NIGHT AS A STRONG UPPER SHORTWAVE TROUGH AND ATTENDANT
SFC FRONT PUSH INTO THE AREA. MODELS HAVE TRENDED JUST A TAD
SLOWER WITH THIS FEATURE OVER THE PAST 24 HOURS SUCH THAT THE
FIRST HALF OF THE DAY ON WEDNESDAY SHOULD BE HALFWAY DECENT
DESPITE SOME CONTINUED PESKY LOW LEVEL CLOUD COVER. TEMPERATURES
WILL CLIMB INTO THE 55 TO 65 RANGE UNDER LIGHT TO MODEST
SOUTHERLY WINDS. BY LATER IN THE AFTERNOON AND INTO THE
EVENING...SHORTWAVE SWINGS INTO THE REGION WITH FAIRLY ROBUST
UPPER DYNAMICAL SUPPORT AND GOOD PVA/MOISTURE ADVECTION. THUS
WILL CONTINUE WITH PRIOR FCSTS IDEA OF HIGH CHC TO LIKELY POPS
(50/60%) DURING A SIX HOUR WINDOW FROM EARLY EVENING TO MIDNIGHT
OR SO. PCPN TENDS TO TAPER OFF AND TREND MORE OROGRAPHIC LATER AT
NIGHT AS POST-FRONTAL FLOW TURNS WESTERLY UNDER MODEST COLD AIR
ADVECTION. COULD ONCE AGAIN SEE SOME TAIL-END FLURRY/SHSN
ACTIVITY AT THE SUMMIT LEVEL OVERNIGHT AS PCPN ENDS...BUT THIS
SHOULD BE LIGHT. LOWS MAINLY IN THE 35 TO 40 RANGE.
SHORTWAVE RIDGING THEN SKIRTS ACROSS THE AREA BY THURSDAY WITH A
GOOD SHOT AT A FEW HOURS OF SUNSHINE THROUGH THE FIRST HALF OF
THE DAY. NEXT SHORTWAVE WILL QUICKLY APPROACH HOWEVER BY LATER IN
THE AFTERNOON WITH A RENEWED THREAT OF SHOWER ACTIVITY TOWARD
DAY`S END AS HIGHS TREND A TAD COOLER INTO THE 45 TO 55 RANGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 403 AM EDT TUESDAY...LARGE HIGH PRESSURE RIDGE WILL SINK
SOUTH TOWARDS THE CAROLINAS...ALLOWING A SHORTWAVE TO TRAVERSE
JUST NORTH OF THE NORTH COUNTRY...PRODUCING RAIN SHOWERS THURSDAY
NIGHT...LINGERING INTO FRIDAY. HIGH PRESSURE WILL BUILD IN BEHIND
THIS SHORTWAVE LATE FRIDAY INTO THE FIRST HALF OF THE WEEKEND.
FOR THE SECOND HALF OF THE WEEKEND...A CLOSED LOW PRESSURE SYSTEM
WILL APPROACH FROM THE WESTERN GREAT LAKES REGION...WITH A WARM
FRONT EXTENDING EASTWARD AHEAD OF THE LOW. THIS WARM FRONT WILL
BRING ANOTHER CHANCE FOR RAIN SHOWERS LATE SATURDAY INTO
SUNDAY...ALONG WITH WARMING TEMPERATURES INTO THE 60S.
THE CUTOFF LOW WILL MOVE NORTHEASTWARD TOWARD THE ST LAWRENCE
VALLEY DELTA...SO THE ASSOCIATED PRECIP WILL HAVE THE GREATEST
IMPACT ON OUR NORTHERN ZONES THROUGH LATE SUNDAY/EARLY MONDAY.
SUNDAY INTO SUNDAY NIGHT WILL EXPERIENCE SOME GUSTY CONDITIONS AS
THE PRESSURE GRADIENT INCREASES AT THE SFC...AND A JET AT 925MB
MOVES OVER THE WESTERN ST LAWRENCE VALLEY.
DRYER CONDITIONS EXPECTED ON MONDAY AS WEAK HIGH PRESSURE BRIEFLY
BUILDS IN AT THE SFC...AHEAD OF THE NEXT SHORTWAVE FEATURE
APPROACHING FROM CENTRAL SOUTHERN CANADA.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...ISOLATED AREAS OF IFR BR/FG WILL BE SLOW
TO BURN OFF THIS MORNING AS LOW LEVEL MOISTURE CONTINUES TO
SLOWLY EDGE NORTHWARD INTO THE NORTH COUNTRY. WITH THIS AREA OF
MOISTURE...MID AND LOW LEVEL CLOUDS WILL AFFECT ALL TAF SITES BY
LATE MORNING TO EARLY AFTERNOON. EXPECT VFR CIGS AND VSBYS TO
PERSIST THROUGHOUT THE DAY. AS EVENING APPROACHES...KMPV AND KRUT
CIGS WILL LOWER TO MVFR WITH BR/FG DEVELOPING AFTER MIDNIGHT.
WINDS WILL GENERALLY BE LIGHT...INCREASING OUT OF THE S-SE AT
5-10KTS THIS AFTERNOON. WIND SPEEDS WILL DECREASE TO LIGHT TO
CALM CONDITIONS TUESDAY NIGHT.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THROUGH 18Z WEDNESDAY...WEAK HIGH PRESSURE RIDGING
WILL BE OVERSHADOWED BY LOW LEVEL MOISTURE...KEEPING VFR TO MVFR
CIGS OVER THE REGION IN SE FLOW.
18Z WEDNESDAY THROUGH 12Z THURSDAY...A COLD FRONT WILL MOVE INTO
THE REGION ON WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT WITH
SCATTERED SHOWERS ALONG WITH SOME AREAS OF MVFR.
12Z THURSDAY THROUGH 00Z FRIDAY...MAINLY VFR AS A RIDGE OF HIGH
PRESSURE WILL BE OVER THE REGION.
00Z FRIDAY THROUGH 18Z FRIDAY...TRENDING BKN/OVC VFR WITH SOME
MVFR IN SCATTERED SHOWERS WITH COLD FRONTAL PASSAGE.
18Z FRIDAY THROUGH 00Z SUNDAY...TRENDING VFR AS A RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1138 AM PDT TUE OCT 9 2012
.DISCUSSION...AS OF 9:00 AM PDT TUESDAY MORNING...SURFACE LOW
PRESSURE SYSTEM CONTINUES TO MOVE VERY SLOWLY SOUTH
SOUTHEAST...CURRENTLY NEAR 35N/125W. OCCASIONAL LIGHTNING STRIKES
WERE ASSOCIATED WITH THE LOW CENTER...BUT CONTINUE WELL OFF THE
CALIFORNIA COAST. PARTLY TO MOSTLY CLOUDS SKIES STREAMED NORTHEAST
OVER SONOMA AND NAPA COUNTIES...WHILE THE REST OF THE REGION
REMAINED MOSTLY CLEAR. TEMPERATURES OVERNIGHT FELL INTO THE MID 40S TO
MID 50S...SIMILAR TO THOSE OBSERVED LAST NIGHT AND NEAR NORMAL FOR
THE MIDDLE OF OCTOBER. IN ADDITION...THE NORTH BAY VALLEY DID SEE
PATCHY DENSE FOG...WITH VISIBILITIES DOWN TO A QUARTER MILE
OVERNIGHT.
ANOTHER DIFFICULT FORECAST IN STORE TODAY THROUGH THE END OF THE
WORK WEEK...AS THE LOW CONTINUES TO MIGRATE SLOWLY SOUTH. UPDATED
THE FORECAST THIS MORNING TO REMOVE SLIGHT CHANCE OF THUNDERSTORMS
ONSHORE...BUT KEPT THEM OVER THE WATERS. ALSO INCREASED COVERAGE
OF SLIGHT CHANCE OF RAIN SHOWERS...AS THE HRRR INDICATED SPOTTY
LIGHT RAIN SHOWERS THIS AFTERNOON WELL INLAND.
HOWEVER...CONFIDENCE REMAINS EXTREMELY LOW WITH LOCATION AND
TIMING OF ANY PRECIPITATION.
OTHERWISE...WE WILL CONTINUE TO MONITOR THE FORECAST CLOSELY AND
UPDATE WITH ANY NEW INFORMATION.
.PREVIOUS DISCUSSION...AS OF 3:45 AM PDT TUESDAY MORNING...A
MIXED BAG OF WEATHER ACROSS THE DISTRICT AND COASTAL WATERS. FOG
PRODUCT IMAGERY AND SFC OBS SHOW PATCHY LOW CLOUDS ALONG THE COAST
AND IN THE NORTH BAY VALLEYS...EVEN THOUGH THE SAN CARLOS SODAR
AND THE FT ORD PROFILER ARE NOT INDC A MARINE LAYER.
WATER VAPOR IMAGERY IS SHOWING THE UPPER LOW CENTERED ABOUT 260
MILES WEST OF THE GOLDEN GATE. A STRONG VORT MAX WEST OF PT REYES
IS ROTATING AROUND THE UPPER LOW. THE VORT MAX HAS THE CLASSIC
COMMA HEAD LOOK ON WATER VAPOR IMAGERY. THIS VORT MAX HAS
GENERATED SHOWERS AND THUNDERSTORMS ...WITH LIGHTNING STRIKES LESS
THAN 50 MILES WEST OF THE NORTH BAY COASTLINE. KMUX RADAR IS INDC
THAT THE SHOWER ACTIVITY IS ABOUT 25 MILES WEST OF PT REYES AS OF
3:30 AM. OTHER VORT MAXES CONTINUE TO ROTATE AROUND THE UPPER LOW AS
IT MOVES SLOWLY SOUTHEAST.
TODAY THROUGH THURSDAY...MODELS ARE IN AGREEMENT IN TAKING THE
UPPER LOW SLOWLY SOUTHEAST TO WEST OF BIG SUR BY EARLY WEDNESDAY
MORNING. HOWEVER...THE MODELS ARE HAVING A DIFFICULT TIME WITH THE
DETAILS. HAVE ADDED A SLIGHT CHC OF SHOWERS/THUNDERSTORMS TO THE
OUTER COASTAL WATERS...INNER COASTAL WATERS NORTH OF THE GOLDEN
GATE...AND IN THE NORTH BAY AS THE VORT MAX ROTATES TOWARDS THE
COAST NORTH OF THE GOLDEN GATE. CONVECTIVE ACTIVITY WILL END IN
THE NORTH BAY BY LATE AFTN...WITH THE SLIGHT CHANCE OF SHOWERS
SHIFTING SOUTH TONIGHT AND WEDNESDAY WITH THE UPPER LOW. DID NOT
MENTION THUNDER FOR TONIGHT...BUT THIS WILL NEED TO BE WATCHED IN
LIGHT OF THE CONVECTIVE ACTIVITY THIS EARLY MORNING. HAVE KEPT THE
MENTION OF THUNDERSTORMS WEDNESDAY AFTN AND EVENING FOR MOST OF
MONTEREY AND SAN BENITO COUNTIES AS IT LOOKS LIKE IT WILL BE QUITE
UNSTABLE WITH LI`S AS LOW AS -3C AND CAPES GREATER THAN 350 J/KG.
SHOWERS COULD LINGER IN THE SOUTH ON THURSDAY WITH WRAP AROUND
MOISTURE FROM THE UPPER LOW AS IT MOVES INTO SOUTHERN CALIFORNIA.
FRIDAY INTO EARLY NEXT WEEK...A WEAK FRONT WILL MOVE INTO NORTHERN
CALIFORNIA FRIDAY AFTN INTO SATURDAY. MEDIUM RANGE MODELS CONTINUE
TO SHOW THIS FRONT SPLITTING AS IT MOVES TO THE COAST. AS OF
NOW...IT LOOKS LIKE ANY RAIN WILL REMAIN NORTH OF THE GOLDEN GATE.
AN ACTIVE STORM TRACK WILL SET UP ACROSS THE PACIFIC NORTHWEST AND
NORTHERN CALIFORNIA SUNDAY INTO NEXT WEEK WITH THE DISTRICT ON THE
SOUTHERN FRINGE. SUNDAY SHOULD BE DRY ACROSS THE DISTRICT. THE JET
COULD DIP A LITTLE FURTHER SOUTH FOR A SLIGHT CHANCE OF WARM
ADVECTION RAIN IN NORTHERN SONOMA COUNTY ON MONDAY.
&&
.AVIATION...AS OF 11:35 AM TUESDAY...LOW CONTINUES TO SPIN OFF THE
COAST. RADAR AND SATELLITE ARE NOT IMPRESSIVE FOR RAIN CHANCES
MOVING INTO OUR AREA SO NEW TAF PACKAGE KEEPS VCSH OUT OF ANY
TERMINALS. TONIGHT IS A VERY TOUGH CALL AS THE ONSHORE FLOW PICKS
UP ALONG WITH HIGHER BL RH VALUES. HOWEVER...THESE TYPE OF SETUPS
BEHIND A LOW HEADING TO THE SOUTH ARE VERY DIFFICULT. FOR NOW DECIDED
TO BRING IN MOSTLY IFR CONDITIONS OVERNIGHT BUT NOT AS PESSIMISTIC
AS SOME OF THE GUIDANCE. WINDS SHOULD NOT BE A FACTOR AND WILL BE
THE TYPICAL AFTERNOON/EVENING SEA BREEZES. HIGH CONFIDENCE THROUGH TODAY.
LOW CONFIDENCE AFTER 05Z.
.VICINITY OF KSFO...VFR THROUGH AT LEAST 03Z. FROM 04Z ON GUIDANCE
BRINGS LOW CLOUDS BACK TO MVFR LEVELS. DECIDED TO GO WITH CIGS
AROUND 015 FROM 05Z ON. AFTERNOON AND EARLY EVENING WINDS OF 11 TO
16 KT EXPECTED. HIGH CONFIDENCE THROUGH 03Z. LOW CONFIDENCE
BEYOND THAT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR THROUGH THE DAY WITH IFR/MVFR
CIGS FORECAST TO RETURN AFTER 07Z. AGAIN...DIFFICULT TO FORECAST
WITH THIS TYPE OF SETUP. SO...HIGH CONFIDENCE THROUGH 06Z WITH LOW
CONFIDENCE AFTER THAT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: STROBIN
AVIATION/MARINE: CANEPA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
904 AM PDT TUE OCT 9 2012
.DISCUSSION...AS OF 9:00 AM PDT TUESDAY MORNING...SURFACE LOW
PRESSURE SYSTEM CONTINUES TO MOVE VERY SLOWLY SOUTH
SOUTHEAST...CURRENTLY NEAR 35N/125W. OCCASIONAL LIGHTNING STRIKES
WERE ASSOCIATED WITH THE LOW CENTER...BUT CONTINUE WELL OFF THE
CALIFORNIA COAST. PARTLY TO MOSTLY CLOUDS SKIES STREAMED NORTHEAST
OVER SONOMA AND NAPA COUNTIES...WHILE THE REST OF THE REGION
REMAINED MOSTLY CLEAR. TEMPERATURES OVERNIGHT FELL INTO THE MID 40S TO
MID 50S...SIMILAR TO THOSE OBSERVED LAST NIGHT AND NEAR NORMAL FOR
THE MIDDLE OF OCTOBER. IN ADDITION...THE NORTH BAY VALLEY DID SEE
PATCHY DENSE FOG...WITH VISIBILITIES DOWN TO A QUARTER MILE
OVERNIGHT.
ANOTHER DIFFICULT FORECAST IN STORE TODAY THROUGH THE END OF THE
WORK WEEK...AS THE LOW CONTINUES TO MIGRATE SLOWLY SOUTH. UPDATED
THE FORECAST THIS MORNING TO REMOVE SLIGHT CHANCE OF THUNDERSTORMS
ONSHORE...BUT KEPT THEM OVER THE WATERS. ALSO INCREASED COVERAGE
OF SLIGHT CHANCE OF RAIN SHOWERS...AS THE HRRR INDICATED SPOTTY
LIGHT RAIN SHOWERS THIS AFTERNOON WELL INLAND.
HOWEVER...CONFIDENCE REMAINS EXTREMELY LOW WITH LOCATION AND
TIMING OF ANY PRECIPITATION.
OTHERWISE...WE WILL CONTINUE TO MONITOR THE FORECAST CLOSELY AND
UPDATE WITH ANY NEW INFORMATION.
.PREVIOUS DISCUSSION...AS OF 3:45 AM PDT TUESDAY MORNING...A
MIXED BAG OF WEATHER ACROSS THE DISTRICT AND COASTAL WATERS. FOG
PRODUCT IMAGERY AND SFC OBS SHOW PATCHY LOW CLOUDS ALONG THE COAST
AND IN THE NORTH BAY VALLEYS...EVEN THOUGH THE SAN CARLOS SODAR
AND THE FT ORD PROFILER ARE NOT INDC A MARINE LAYER.
WATER VAPOR IMAGERY IS SHOWING THE UPPER LOW CENTERED ABOUT 260
MILES WEST OF THE GOLDEN GATE. A STRONG VORT MAX WEST OF PT REYES
IS ROTATING AROUND THE UPPER LOW. THE VORT MAX HAS THE CLASSIC
COMMA HEAD LOOK ON WATER VAPOR IMAGERY. THIS VORT MAX HAS
GENERATED SHOWERS AND THUNDERSTORMS ...WITH LIGHTNING STRIKES LESS
THAN 50 MILES WEST OF THE NORTH BAY COASTLINE. KMUX RADAR IS INDC
THAT THE SHOWER ACTIVITY IS ABOUT 25 MILES WEST OF PT REYES AS OF
3:30 AM. OTHER VORT MAXES CONTINUE TO ROTATE AROUND THE UPPER LOW AS
IT MOVES SLOWLY SOUTHEAST.
TODAY THROUGH THURSDAY...MODELS ARE IN AGREEMENT IN TAKING THE
UPPER LOW SLOWLY SOUTHEAST TO WEST OF BIG SUR BY EARLY WEDNESDAY
MORNING. HOWEVER...THE MODELS ARE HAVING A DIFFICULT TIME WITH THE
DETAILS. HAVE ADDED A SLIGHT CHC OF SHOWERS/THUNDERSTORMS TO THE
OUTER COASTAL WATERS...INNER COASTAL WATERS NORTH OF THE GOLDEN
GATE...AND IN THE NORTH BAY AS THE VORT MAX ROTATES TOWARDS THE
COAST NORTH OF THE GOLDEN GATE. CONVECTIVE ACTIVITY WILL END IN
THE NORTH BAY BY LATE AFTN...WITH THE SLIGHT CHANCE OF SHOWERS
SHIFTING SOUTH TONIGHT AND WEDNESDAY WITH THE UPPER LOW. DID NOT
MENTION THUNDER FOR TONIGHT...BUT THIS WILL NEED TO BE WATCHED IN
LIGHT OF THE CONVECTIVE ACTIVITY THIS EARLY MORNING. HAVE KEPT THE
MENTION OF THUNDERSTORMS WEDNESDAY AFTN AND EVENING FOR MOST OF
MONTEREY AND SAN BENITO COUNTIES AS IT LOOKS LIKE IT WILL BE QUITE
UNSTABLE WITH LI`S AS LOW AS -3C AND CAPES GREATER THAN 350 J/KG.
SHOWERS COULD LINGER IN THE SOUTH ON THURSDAY WITH WRAP AROUND
MOISTURE FROM THE UPPER LOW AS IT MOVES INTO SOUTHERN CALIFORNIA.
FRIDAY INTO EARLY NEXT WEEK...A WEAK FRONT WILL MOVE INTO NORTHERN
CALIFORNIA FRIDAY AFTN INTO SATURDAY. MEDIUM RANGE MODELS CONTINUE
TO SHOW THIS FRONT SPLITTING AS IT MOVES TO THE COAST. AS OF
NOW...IT LOOKS LIKE ANY RAIN WILL REMAIN NORTH OF THE GOLDEN GATE.
AN ACTIVE STORM TRACK WILL SET UP ACROSS THE PACIFIC NORTHWEST AND
NORTHERN CALIFORNIA SUNDAY INTO NEXT WEEK WITH THE DISTRICT ON THE
SOUTHERN FRINGE. SUNDAY SHOULD BE DRY ACROSS THE DISTRICT. THE JET
COULD DIP A LITTLE FURTHER SOUTH FOR A SLIGHT CHANCE OF WARM
ADVECTION RAIN IN NORTHERN SONOMA COUNTY ON MONDAY.
&&
.AVIATION...AS OF 7:30 AM TUESDAY...VARIOUS CLOUD LAYERS ARE
DEVELOPING OVER THE BAY AREA AND CENTRAL COAST AS THE LARGE UPPER
LOW PRESSURE AREA TO THE WEST GETS A BIT CLOSER TO THE AREA THIS
MORNING. THE MODELS HAVE BEEN PREDICTING AN INCREASE IN LOW LEVEL
CLOUDINESS OVERNIGHT. SOME TERMINALS ARE STILL REPORTING VFR
HOWEVER. LOWER CONFIDENCE IN THE FORECAST THIS MORNING.
VICINITY OF KSFO...VFR THROUGH THE DAY TODAY AS CLOUDS QUICKLY
LIFTED THIS MORNING AND VARIOUS CAMS SHOW NEARLY CLEAR SKIES
ACROSS THE BOARD. ONLY CAUTION WOULD BE IF ANY CIGS COME IN OFF
THE COAST THIS MORNING HOWEVER RADAR/SATELLITE SHOWS THE CLOSEST
BAND STALLING AND DISSIPATING SO FEEL THEY WILL NOT HAVE ANY
IMPACT THROUGH 20Z. UPPER LOW TO THE WEST WILL DRIFT CLOSER THE
AREA TODAY AND TONIGHT CAUSING A FEW SHOWERS IN INCREASINGLY
UNSTABLE AIRMASS.
KSFO BRIDGE APPROACH...CLOUDS CONFINED TO THE EAST BAY MOSTLY
FROM KOAK TO THE NORTH AND SHOULD NOT IMPACT THE APPROACH.
THEREFORE...OVERALL SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...A PATCH OF LOW CLOUDS IS OBSERVED
OVER THE MONTEREY BAY NEAR KWVI. KSNS AND KMRY ARE STILL REPORTING
VFR AT THIS HOUR AND BELIEVE THIS WILL HOLD THOUGH CONFIDENCE IS
LOW. VFR IS LIKELY FROM LATE MORNING THROUGH THE AFTERNOON WITH A
SIMILAR CHANCE FOR SHOWER ACTIVITY DUE TO INBOUND LOW PRESSURE
AREA.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: STROBIN
AVIATION/MARINE: CANEPA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
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WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
241 PM EDT Tue Oct 9 2012
.SYNOPSIS...
Looking at the long wave pattern, we see a trough dominating much of
North America with a northern stream short wave trough moving across
the Upper Midwest. A cut-off low is noted off the California coast.
Surface analysis shows a stationary front across the northern FL
Peninsula with high pressure centered over the TN Valley. Water
vapor imagery indicates dry air over the northeast Gulf Coast
region. Visible satellite shows that the the low stratus deck
continues to gradually erode. However, many locations in Southwest
and South Central GA remained overcast as of 18Z.
&&
.NEAR TERM [through Tonight]...
The main issue for tonight into Wednesday morning is whether or not
there will be a repeat of the low ceilings and patchy fog that we
saw this morning. Examination of our hi-res local WRF time-height
cross section and forecast soundings in BUFKIT does reveal a very
shallow moist layer and inversion near the surface, similar to this
morning. The "long range" RAP forecast valid at 09z tonight is
showing a similar profile. Therefore, we went with persistence and
are forecasting another round of patchy fog to develop late tonight
with an increase in low clouds towards dawn. The low temperature
forecast utilized an even blend of the MAV and MET guidance, which
were fairly similar.
.SHORT TERM [Wednesday through Thursday night]...
The negatively-tilted long wave trough over the eastern CONUS will
deamplify as the primary short wave lifts northeast across the
eastern Great Lakes and New England and the upper low moves into CA.
Surface high pressure will remain in control of our weather locally
which will maintain comfortable temps and humidity levels, even with
the passage of a dry cold front Wednesday night into Thursday. Min
temps will be several degrees below normal through the period. Max
temps will be at or slightly above normal on Wednesday and at or
slightly below normal on Thursday. We do not anticipate another
round of nocturnal low clouds after tonight.
.LONG TERM [Friday through next Tuesday]...
The latest GFS & ECMWF forecast ridging at 500 mb over the Southeast
U.S. through Saturday, followed by a slight fall in the heights into
early next week as trough (currently off the CA coast) translates
quickly northeastward over the Ohio Valley. An area of high pressure
centered to our northeast will provide our forecast area with east
to northeast winds. Both global models forecast the airmass to be
quite dry, though some increase in boundary layer moisture is likely
over the weekend and next week as the boundary layer becomes
modified by its increasing trajectory over the western Atlantic.
Rain chances will be near climo, which this time of year (typically
our driest period) is less than 15%. Temperatures will be a little
above climo, especially during the daytime, with highs in the
generally in the mid 80s (climo is lower 80s). Lows will start off
(Friday & Saturday) in the 50s, then warm into the 60s Sunday
through next Tuesday. Of course, highs will be slightly cooler and
lows slightly warmer than this at the beaches.
&&
.MARINE...
Offshore flow will continue over the waters for the next several
days. Northwest to north winds on Wednesday will veer to the
northeast and increase behind a cold front late Wednesday night into
Thursday. At this time, it appears that winds speeds will remain
just below headline criteria at around 15 kt. As high pressure moves
off the Mid Atlantic coast this weekend, easterly winds could
increase to cautionary levels from late Saturday into Sunday morning.
&&
.AVIATION...
[through 18z Wednesday] The low cloud deck from this morning that
has persisted into the early afternoon hours is finally starting to
break up. It appears as though KABY and KVLD will be the last to
break out into VFR conditions, but this should occur later this
afternoon. However, we are forecasting another round of low cigs and
patchy fog to develop late tonight with IFR conditions expected to
return.
&&
.FIRE WEATHER...
A brief period of low RH values and high dispersions are possible
Wednesday afternoon across northwest Florida, but conditions seem
too marginal for any headlines at this time. Low RH values are
likely again on Thursday afternoon, but dispersions are forecast to
be lower.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 57 85 54 83 55 / 0 0 0 0 0
Panama City 61 84 61 84 61 / 0 0 0 0 0
Dothan 54 82 53 81 54 / 0 0 0 0 0
Albany 55 83 54 81 52 / 0 0 0 0 0
Valdosta 57 84 54 80 54 / 0 0 0 0 0
Cross City 57 86 54 85 57 / 0 0 0 0 0
Apalachicola 62 83 59 82 59 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Short Term/Marine...Wool
Long Term...Fournier
Rest of Discussion...DVD
AREA FORECAST DISCUSSION
NWS GOODLAND KS
236 PM MDT TUE OCT 9 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 233 PM MDT TUE OCT 9 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH IN
STILL IN PLACE ACROSS THE US. A POSITIVELY TILTED LONGWAVE TROUGH
AXIS CURRENTLY EXTENDS SOUTHWEST ALONG THE UPPER MISSISSIPPI VALLEY
ACROSS CENTRAL KANSAS. REX BLOCK IS STILL IN PLACE OFF THE
WESTERN...WITH ASSOCIATED CLOSED LOW CENTERED JUST OFF THE
CALIFORNIA COAST. AT THE SURFACE HIGH PRESSURE IS CURRENTLY IN PLACE
ACROSS THE NORTHERN AND HIGH PLAINS REGIONS BEHIND A COLD FRONT THAT
MOVED THROUGH WESTERN KANSAS THIS MORNING.
SKIES SHOULD CLEAR ACROSS THE CWA AS STRATUS ACROSS THE WESTERN
CWA SHIFTS WEST AND DISSIPATES. THE REMAINDER OF THE NIGHT SHOULD
BE MOSTLY CLEAR WITH ONLY PASSING HIGH CLOUDS. THERE IS SOME
INDICATION OF STRATUS/FOG DEVELOPMENT OVER EASTERN
COLORADO...HOWEVER THIS LOOKS TO REMAIN JUST WEST OF OUR CWA...SO
NO MENTION IS INCLUDED IN THE FORECAST AT THIS TIME.
WINDS WILL DECREASE LATE THIS AFTERNOON AND EARLY THIS EVENING AS
HIGH PRESSURE CONTINUES TO BUILD SOUTH. WITH A COOL AIRMASS IN PLACE
MOST OF THE CWA SHOULD SEE TEMPS DROP TO THE 30-35F RANGE...WITH THE
COLDEST TEMPS IN THE EAST. WINDS WILL INCREASE FROM THE SOUTHWEST IN
THE WEST TOWARDS SUNRISE...WHICH WILL ALSO HELP BRING TEMPS BACK UP
ABOVE FREEZING. DESPITE THIS...THERE IS STILL A WINDOW IN THE WEST
BETWEEN 06-09Z WHEN MANY LOCATIONS WILL BE WITHIN FROST ADVISORY
CRITERIA. LOCATIONS NORTH AND EAST HAVE ALREADY SEEN A HARD
FREEZE...SO I ONLY ISSUED A FROST ADVISORY FOR THE SOUTHWEST
QUADRANT OF MY CWA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 233 PM MDT TUE OCT 9 2012
UPPER FLOW WILL BE NORTHWEST WEDNESDAY NIGHT TRANSITIONING TO A MORE
WESTERLY FLOW AS A RIDGE BUILDS INTO THE CENTRAL ROCKIES ON
THURSDAY. FLOW BECOMES SOUTHWESTERLY THURSDAY NIGHT AHEAD OF AN
UPPER THAT MOVES TO A POSITION WEST OF THE FOUR CORNERS REGION
FRIDAY. SURFACE HIGH PRESSURE WILL CONTINUE OVER THE CENTRAL PLAINS
WEDNESDAY NIGHT. LOW PRESSURE WILL MOVE INTO EASTERN COLORADO
THURSDAY. A COLD FRONT WILL MOVE INTO NORTHWEST KANSAS THURSDAY
AFTERNOON/NIGHT FOLLOWED BY HIGH PRESSURE FRIDAY.
DRY CONDITIONS WILL CONTINIUE THROUGH THURSDAY WITH LACK OF FORCING
AND MOISTURE. LATE THURSDAY NIGHT/EARLY FRIDAY MORNING DYNAMICS
APPROACH THE FA FROM THE SOUTHWEST. PLAN TO KEEP A SMALL AREA OF
SLIGHT CHANCE/CHANCE POPS ACROSS THE EXTREME SOUTHERN FA.
PRECIPITATION APPEARS MORE LIKELY FRIDAY SO HAVE INCREASED POPS TO
HIGHER CHANCE POPS.
MIN TEMPERATURES WILL RANGE FROM THE LOWER 40S WEDNESDAY NIGHT
COOLING TO THE UPPER 30S THURSDAY NIGHT. MAX TEMPERATURES THURSDAY
WILL BE AROUND 70. CLOUDS AND PRECIPITATION WILL KEEP HIGH
TEMPERATURES FRIDAY IN THE UPPER 50S
FOR FRIDAY NIGHT THROUGH MONDAY...THE UPPER TROUGH WILL BE OVER THE
CENTRAL ROCKIES FRIDAY NIGHT AND LIFT NORTHEAST INTO NORTHCENTRAL
NEBRASKA SATURDAY. NORTHWEST FLOW WILL RESUME SUNDAY AND CONTINUE
THROUGH TUESDAY. A SURFACE TROUGH WILL BE OVER EASTERN COLORADO
FRIDAY NIGHT. THIS AREA OF LOW PRESSURE WILL MOVE INTO NORTHEAST
NEBRASKA SATURDAY FOLLOWED BY HIGH PRESSURE SATURDAY NIGHT AND
SUNDAY. ANOTHER TROUGH WILL DEVELOP IN EASTERN COLORADO MONDAY
REPLACED BY HIGH PRESSURE TUESDAY.
GOOD DYNAMICS AND MOISTURE WILL SUPPORT HIGH CHANCE AND LIKELY POPS
FRIDAY NIGHT. PRECIPITATION CHANCES LOWER TO SLIGHT CHANCE OVER THE
FAR NORTHWEST FA SATURDAY AS THE SYSTEM MOVES INTO NEBRASKA.
SUBSIDENCE MOVES IN BEHIND THIS SYSTEM. POPS WILL BE NIL FROM
SATURDAY THROUGH TUESDAY. MIN TEMPERATURES WILL BE IN THE MID 40S
FOR THIS PART OF THE FORECAST. MAX TEMPERATURES WILL RISE TO AROUND
70 EACH DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1122 AM MDT TUE OCT 9 2012
MVFR STRATUS DECK CONTINUES TO MOVE SOUTH TO SOUTHWEST OVER THE
AREA...WITH THE BACK EDGE ALONG THE KS/NE STATE LINE. BASED ON
TIMING FROM SATELLITE...I EXPECT VFR CONDITIONS AT KMCK BY 19Z.
ITS A TOUGHER CALL AT KGLD...WHERE STRATUS IS MORE EXTENSIVE. IT
DOES APPEAR THAT STRATUS IS BEGINNING TO DISSIPATE ALONG THE
NORTHERN EDGE OF THE STRATUS FIELD IN SW NEBRASKA. THIS MATCHES
TRENDS BY SHORT RANGE GUIDANCE. FOR NOW I AM ANTICIPATING MVFR
CIGS AT KGLD UNTIL 20-21Z. AFTER STRATUS CLEARS AT BOTH TERMINALS
THIS AFTERNOON...VFR CONDITIONS SHOULD PREVAIL THROUGH THE
REMAINING TAF PERIOD. GUSTY WINDS SHOULD DIMINISH THIS AFTERNOON
AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH. LIGHT AND
VARIABLE WINDS ARE THEN EXPECTED THROUGH MOST OF THE NIGHT...WITH
GUSTY SOUTH-SOUTHWEST WINDS REDEVELOPING OVER KGLD WEDNESDAY
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FROST ADVISORY FROM MIDNIGHT MDT /1 AM CDT/ TONIGHT TO 9 AM MDT
/10 AM CDT/ WEDNESDAY FOR KSZ013-014-027-028-041-042.
CO...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM MDT WEDNESDAY FOR
COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1135 AM MDT TUE OCT 9 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 401 AM MDT TUE OCT 9 2012
FORECAST CONCERNS WILL BE WINDS TODAY AND WEDNESDAY...HOW COOL TO
MAKE TODAY...HOW MUCH TO WARM UP THE NEXT TWO DAYS...AND CHANCE OF
PRECIPITATION LATE IN THE SHORT TERM. SATELLITE CONTINUING TO SHOW AN
AMPLIFIED AND BLOCKY FLOW FROM THE PACIFIC INTO EASTERN NORTH
AMERICA. UPPER LOW NEAR HAS MOVED CLOSER TO THE COAST BUT HAS BEGUN
TO TAKE A MORE SOUTHWARD COURSE. STRONG SYSTEM DIGGING INTO THE NORTH
CENTRAL PORTION OF THE COUNTRY IS PUSHING A COLD FRONT THROUGH THE
AREA AT THIS TIME.
AT JET LEVEL...MODELS WERE CLOSE WITH THE NAM DOING A LITTLE BETTER
THAN THE REMAINING OUTPUT. AT MID LEVELS...MODELS TENDED TO HAVE THE
FEATURES/HEIGHT FIELD TOO FAR SOUTH AND WEST. OVERALL THE CANADIAN...
GFS...AND UKMET WERE DOING THE BEST. HOWEVER...THE NAM DID BETTER ON
THE NORTH CENTRAL SYSTEM. THE MODELS WERE NOT QUITE FAST ENOUGH
WITH THE FRONT. THE HRRR AND RUC WERE DOING THE BEST FOLLOWED BY THE
NAM ON THAT AND OVERALL. ON THE LOW LEVEL THERMAL FIELD THE MODELS
OVERALL WERE CLOSE. HOWEVER...THEY TENDED TO NOT HAVE THE COLD AIR
TO OUR NORTH FAR ENOUGH SOUTH AND WEST. IN THIS AREA THE CANADIAN
AND THE UKMET WERE DOING THE BEST.
TODAY/TONIGHT...AFTER SPEEDING UP THE FRONT THE MODELS HAVE NOW
SLOWED THE FRONT DOWN. LOOKS LIKE IT WILL BE THROUGH THE NORTHWEST
HALF OF THE AREA BY 12Z AND THROUGH ALL THE AREA BY 15Z OR SO.
WINDS LOOK TO STAY UNDER WIND ADVISORY CRITERIA. THE TIGHTEST
GRADIENT AND 3 HOUR PRESSURE RISES ARE DONE BY 15Z AND THEN THEY
START STEADILY DECREASING. BY THE TIME THE SUN COMES UP AND STARTS
THE HEATING...WHICH MAY BE LIMITED BY CLOUD COVER...THOSE
PARAMETERS WILL HAVE BEGUN THIS DECREASE.
THE MODELS ALSO LOOK LIKE THEY HAVE BACK OFF A LITTLE ON THE STRATUS
BEHIND IT. SOME OTHER MID AND HIGH LEVEL CLOUDS WILL MOVE THROUGH AS
WELL DUE TO THE SHORTWAVE TROUGH AND A RIGHT REAR QUADRANT OF THE
JET MOVES FROM NORTH TO SOUTH ACROSS THE AREA THIS MORNING. AT THE
VERY LEAST THIS IS GOING TO PRODUCE THICK CLOUD COVER DURING THIS
TIME. SUBSIDENCE AND CLEARING SHOULD OCCUR BEGINNING AT 18Z. MODELS
HAVE BEEN TRENDING COOLER WITH THE TEMPERATURES AND FOLLOWED THAT
TREND IN THE GRIDS.
VERY LIGHT WINDS AND LOW DEWPOINTS WITH LITTLE IF ANY CLOUD COVER
TONIGHT. THE BEST RADIATIONAL CONDITIONS OCCUR OVER THE NORTHEAST
AND EASTERN COUNTIES AND LOWERED OVERNIGHT LOWS AS A RESULT.
WEDNESDAY/WEDNESDAY NIGHT...SURFACE RIDGE MOVES OFF AS LEE TROUGH
DEVELOPS. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS INCREASE BY
18Z WHICH SHOULD LEAD TO AT LEAST BREEZY AND POSSIBLY WINDY
CONDITIONS DEVELOPING. HIGHER CLOUDS INCREASE DURING THE AFTERNOON IN
THE WEST. MODELS BEGIN DIFFERING HERE ON THE AMOUNT OF WARMUP. WILL
HAVE A COLD START...ESPECIALLY EAST. MODELS HAVE BEEN REALLY ALL
OVER THE PLACE RECENTLY. USING THE 2 METER TEMPERATURES THAT HAVE
BEEN DOING THE BEST AND RECENT 850 MB TEMPERATURE BIASES LED TO ONLY
A SLIGHT ADJUSTMENT TO THE CURRENT FORECAST.
RIGHT REAR QUADRANT OF THE JET MOVES SLOWLY NORTH TO SOUTH ACROSS
THE AREA DURING THE NIGHT. THIS WILL INCREASE CLOUDS PLUS LOW LEVEL
WARM AIR ADVECTION INCREASES THROUGH THE NIGHT. SO WILL BE MUCH
WARMER THAN IT HAS RECENTLY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OVER OR NEAR
THE NORTHERN PORTION OF THE AREA THROUGH THE DAY. UPPER RIDGE
BUILDS TO OUR WEST IN ADVANCE OF UPPER LOW IN THE DESERT SOUTHWEST.
MODELS HAVE SLOWED IN THEIR PROGRESSION OF THIS FEATURE. THIS HAS
ALLOWED A WEST TO WEST NORTHWEST FLOW TO REMAIN A LITTLE LONGER
OVER THE AREA. SO WILL PROBABLY HAVE A LITTLE MORE CLOUD COVER...
ESPECIALLY IN THE NORTH.
BUT WHAT IS MORE IMPORTANT...THIS IS ALLOWING A WEAK SHORTWAVE
TROUGH IN THE NORTH CENTRAL PORTION OF THE COUNTRY TO PUSH A
BACKDOOR COLD FRONT THROUGH THE AREA. MODELS DO SHOW THIS IN A
SIMILAR FASHION BUT DIFFER DRAMATICALLY ON HOW MUCH TO COOL OFF THE
TEMPERATURES. THERE IS A 10 TO 15 DEGREE DIFFERENCE. HEIGHTS RISE
OVER THE PREVIOUS DAY WITH SIMILAR MID LEVEL TEMPERATURES. THE NAM
NWP AND 2 METER IS BY FAR THE WARMEST WITH THE SREF AND UKMET NEXT IN
LINE. THE GFS AND ECMWF FOLLOWED BY THE CANADIAN ARE THE COOLEST.
WHAT ENDED UP DOING WAS SPLITTING THE DIFFERENCE BETWEEN THE
EXTREMES. HOWEVER...COULD SEE EITHER EXTREME OCCURRING.
AGAIN THE MODELS DIFFER ON HOW FAR SOUTH TO TAKE THE FRONT WHICH
WILL AFFECT PRECIPITATION CHANCES DURING THE NIGHT. AGAIN MODELS ARE
SPLIT NEARLY EVENLY ON THE DIFFERENT SOLUTIONS. USUALLY IN THESE
SITUATIONS THE MODEL WITH BETTER TERRAIN ENDS UP HAVING A BETTER
DEPICTION OF THE FRONT. CONSIDERING THE SYNOPTIC PATTERN BELIEVE THE
FARTHER NORTH SOLUTIONS OF WHERE THE FRONT STALLS OUT ARE THE BEST.
THIS ENDS UP BEING THE NAM...UKMET AND CANADIAN. THE FRONT STALLS
OVER SOUTHEAST COLORADO AND SOUTHWEST KANSAS EARLY AND THEN MOVES
NORTH OVERNIGHT.
EVEN THOUGH THE MODELS ARE SLOWER THEY SHOOT OUT A SHORTWAVE INTO
THE AREA AFTER 06Z. ALSO A STRONGER RIGHT REAR QUADRANT
DEVELOPS/MOVES OVER THE AREA...ESPECIALLY AFTER 06Z. ELEVATED CAPE
DEVELOPS OVER THE AREA...ALTHOUGH THEY DIFFER HOW MUCH AND HOW FAR
NORTH. THERE IS ALSO LIMITED ELEVATED CINH. STRONG ISENTROPIC LIFT
DEVELOPS ON THE 300 SURFACE. SATURATED PRESSURE DEFICITS ALSO
DRAMATICALLY DECREASE AS WELL. THE 06Z NAM CAME IN EVEN MORE
FAVORABLE THAN THE 00Z. ALL THIS PLUS SREF AND GEFS PROBABILITIES
SUPPORT HAVING SLIGHT CHANCE TO LOW CHANCE POPS IN OUR SOUTHERN
PORTION AFTER 06Z.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 401 AM MDT TUE OCT 9 2012
RELATIVELY LARGE EARLY SEASON CUTOFF LOW WILL MOVE ACROSS SOUTHEAST
UTAH AND THEN OVER THE CENTRAL ROCKIES INTO THE NEBRASKA PANHANDLE
BY SATURDAY. CYCLOGENESIS WILL INCREASE AS THIS SYSTEM MOVES OUT
ONTO THE PLAINS. INSTABILITY AXIS WILL BE POSITIONED ACROSS THE
COLORADO/KANSAS BORDER AND EXTENDING SOUTH ACROSS TEXAS AND EASTWARD
ACROSS MUCH OF THE REST OF THE STATE. MODELS DIFFER FROM YESTERDAY
IN THAT BOTH THE EC AND THE GFS TAKE THE LOW THROUGH EASTERN
NEBRASKA PANHANDLE AND INTO SOUTHERN MINNESOTA. COMBINED WITH
THIS...A 250 MB JET STREAK WILL BE IN PLACE ACROSS NEW MEXICO AND
THEN UP THROUGH WESTERN KANSAS. AT THE SURFACE...LEE TROUGH ACROSS
EASTERN COLORADO WILL QUICKLY DEEPEN AS COLD FRONT BEGINS TO MOVE
THROUGH THE REGION. CHANCES FOR PRECIPITATION STILL LOOK TO BE ON
TRACK WITH THIS SYSTEM...WITH A CHANCE THAT SOME OF THESE STORMS MAY
BE SEVERE. MUCH OF THE SEVERE ACTIVITY APPEARS TO INITIATE WELL EAST
OF THE CWA AS BETTER OVERALL PROFILE SETS UP ACROSS IOWA AND
MISSOURI. SYSTEM DOES NOT APPEAR TO USHER IN TOO MUCH COLD AIR BUT
DOES TRY TO DRY SLOT THE AREA BY SATURDAY MORNING. IF THIS REIGNS
TRUE...SECTIONS OF THE AREA MAY SEE LITTLE TO NO PRECIPITATION.
SUBSIDENCE WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM AHEAD OF
ANOTHER COLD FRONT THAT WILL MOVE ACROSS THE AREA BY EARLY NEXT
WEEK. A SHORTWAVE TROUGH WILL ALSO MOVE ACROSS THE NORTHERN PLAINS
DURING THIS TIME...WITH PRECIPITATION CHANGES REMAINING WELL NORTH
OF THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1122 AM MDT TUE OCT 9 2012
MVFR STRATUS DECK CONTINUES TO MOVE SOUTH TO SOUTHWEST OVER THE
AREA...WITH THE BACK EDGE ALONG THE KS/NE STATE LINE. BASED ON
TIMING FROM SATELLITE...I EXPECT VFR CONDITIONS AT KMCK BY 19Z.
ITS A TOUGHER CALL AT KGLD...WHERE STRATUS IS MORE EXTENSIVE. IT
DOES APPEAR THAT STRATUS IS BEGINNING TO DISSIPATE ALONG THE
NORTHERN EDGE OF THE STRATUS FIELD IN SW NEBRASKA. THIS MATCHES
TRENDS BY SHORT RANGE GUIDANCE. FOR NOW I AM ANTICIPATING MVFR
CIGS AT KGLD UNTIL 20-21Z. AFTER STRATUS CLEARS AT BOTH TERMINALS
THIS AFTERNOON...VFR CONDITIONS SHOULD PREVAIL THROUGH THE
REMAINING TAF PERIOD. GUSTY WINDS SHOULD DIMINISH THIS AFTERNOON
AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH. LIGHT AND
VARIABLE WINDS ARE THEN EXPECTED THROUGH MOST OF THE NIGHT...WITH
GUSTY SOUTH-SOUTHWEST WINDS REDEVELOPING OVER KGLD WEDNESDAY
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...PMM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 PM EDT TUE OCT 9 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 424 PM EDT TUE OCT 9 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER CNTRL
NAMERICA. EMBEDDED IN THE TROF IS A SHORTWAVE EXTENDING FROM NRN
ONTARIO THRU NW WI TO SRN MN. AREA OF DEEP LAYER FORCING PER
QVECTORS AND STRENGTHENING LOW-MID LEVEL FRONTOGENESIS IN REPONSE TO
SHORTWAVE HAS HELPED TO DEVELOP AREA OF -RA ACROSS SE MN ACROSS WI
AND INTO MUCH OF UPPER MI TODAY.
FCST FOCUS IN THE SHORT TERM WILL SHIFT TO A DEVELOPING LAKE EFFECT
REGIME AS 850MB TEMPS FALL TOWARD -8C UNDER DEEP CYCLONIC FLOW. AS
DEEP LAYER FORCING SHIFTS E TONIGHT...AREA OF PCPN CURRENTLY
AFFECTING ALL BUT THE FAR WRN FCST AREA SHOULD END BY MID EVENING.
LAKE EFFECT PCPN WILL THEN DEVELOP/INCREASE FROM W TO E TONIGHT THRU
WED MORNING AS 850MB TEMPS FALL TO ABOUT -5C E TO -8C W BY 12Z.
UPSTREAM KINL SOUNDING AT 12Z TODAY SHOWED 850MB TEMP OF -3C WITH
DEEP MOISTURE THRU 600MB. WRN LAKE SUPERIOR BUOY SHOWS A WATER TEMP
OF 7C. FOR LAKE EFFECT PURPOSES...8C IS PROBABLY A GOOD OVERALL
ESTIMATE FOR WRN LAKE SUPERIOR SINCE THERE IS LIKELY SOME WARMER
WATER TOWARD SHORE. GIVEN THE UPSTREAM DEEP MOISTURE...THERE SHOULD
BE A PERIOD WHERE DEEP MOISTURE COINCIDES WITH SUFFICIENT OVERWATER
INSTABILITY FOR DEVELOPMENT OF DECENT COVERAGE OF LAKE EFFECT PCPN
TONIGHT. WITH WINDS VEERING NW...BEST LOW-LEVEL CONVERGENCE OVER THE
W SHOULD SET UP INTO GOGEBIC/ONTONAGON COUNTIES DUE TO LAND BREEZE
WIND COMPONENT OFF NW WI. TIME SECTIONS SHOW DENDRITIC SNOW GROWTH
TEMPS DIPPING INTO THE TOP OF CONVECTIVE/MOIST LAYER...SO WOULDN`T
BE SURPRISED TO SEE AN INCH OR TWO OF SNOW ACCUMULATION IN THE HIGH
TERRAIN...PERHAPS ISOLATED 3 INCH AMOUNTS. PCPN WILL BE MORE OF A
RAIN/GRAUPEL MIX DOWN TOWARD THE LAKE. OVER THE E...MARINE
MODIFICATION OF LOW LEVEL TEMPS WILL BE MORE PRONOUNCED DUE TO
LONGER FETCH OVER WARMER WATERS (ERN LAKE SUPERIOR BUOY SHOWS WATER
TEMP OF 10C AND IT IS LIKELY WARMER TOWARD SHORE). SO PCPN WILL BE
MORE RAIN OR RAIN/GRAUPEL RATHER THAN SNOW. MAY SEE SOME MINOR
ACCUMULATIONS.
FCST AREA IS SITUATED UNDER 850MB THERMAL TROF THRU THE DAY WED...
SO LAKE EFFECT PCPN WILL CONTINUE. HOWEVER...DEEPER MOISTURE PULLS
OUT FROM W TO E...AND FCST SOUNDINGS SHOW MORE OF A WELL-MIXED
BOUNDARY LAYER DEVELOPING AS DRIER AIR MAKES INROADS AT LOW LEVELS
AS WELL. DAYTIME HEATING WILL ALSO INCREASINGLY WORK TO DISRUPT LAKE
EFFECT PROCESSES. IN THE END...THIS WILL SPELL AN END TO LAKE EFFECT
PCPN OVER THE W IN THE AFTN AND A DIMINISHING TREND OVER THE E
DURING THE DAY. MAY SEE MINOR ADDITIONAL SNOW ACCUMULATIONS UP TO AN
INCH DURING THE MORNING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 424 PM EDT TUE OCT 9 2012
HIGH PRESSURE RIDGE WILL BE MOVING ACROSS UPPER MICHIGAN ON
WEDNESDAY EVENING. THERE WILL BE LINGERING LAKE EFFECT PCPN OVER THE
EAST IN THE EVENING BEFORE WINDS BACK TO THE WEST AND SHIFT IT
TOWARDS ONTARIO. MEANWHILE TO THE WEST...A SHORTWAVE THAT IS
CURRENTLY JUST EAST OF ALASKA WILL BE DROPPING THROUGH THE NORTHWEST
FLOW AND INTO LAKE SUPERIOR EARLY THURSDAY MORNING. QUESTION FOR THE
FORECAST IS HOW FAR S THE SHORTWAVE WILL DIG. GEM/GFS ON THE
SOUTHERN TRACK...WITH THE NAM/ECMWF ON THE NORTH. COULD END UP
MAKING A HUGE DIFFERENCE IN THE FORECAST PCPN AMNTS AND THUS SNOW
POTENTIAL. BEST FORCING...VERY STRONG H850-700 WAA ASSOCIATED WITH
THIS WAVE AND IS CO-LOCATED WITH THE BEST MOISTURE OVER THE NORTH
HALF OF THE CWA...MAINLY FROM TWIN LAKES AND HOUGHTON SOUTHEAST TO
MANISTIQUE/NEWBERRY. WITH THE DIFFERENCES IN THE EXACT LOCATION OF
THE WAA...DID SHIFT THE PCPN CHANCES A LITTLE FARTHER SOUTH BASED
OFF LATEST VARIABILITY IN THE MODELS AND POTENTIAL FARTHER S
SOLUTION. THE BEST FORCING IS WITHIN THE SNOW GROWTH ZONE AND WITH
THE LLVL TEMPS OVER THE KEWEENAW PENINSULA NOW REMAINING AT OR A
DEGREE ABOVE FREEZING AND DURING THE COOLEST TIME OF THE DAY...THINK
THE INTENSITY OF THE PCPN SHOULD ALLOW IT TO FALL AS SNOW. THIS
MODERATE...TO POTENTIALLY HEAVY...SNOW FALLING JUST BEFORE DAYBREAK
COULD CAUSE SOME TRAVEL ISSUES IN THE KEWEENAW ON THURSDAY MORNING.
RIGHT NOW...HAVE AROUND 2 INCHES OVER THE HIGHER TERRAIN WITH LESSER
AMNTS AT LOWER ELEVATIONS AND NEAR THE SHORELINE WHERE IT WILL MIX
WITH RAIN. THIS IS A VERY DIFFICULT FORECAST FOR THE KEWEENAW WITH
SUBTLE CHANGES MAKING A DIFFERENCE BETWEEN RAIN/SNOW.
ELSEWHERE...PCPN AMNTS ARE A LITTLE MORE UNCERTAIN...BUT STILL
THINK MUCH OF THE AREA WOULD SEE SNOW OR A RAIN/SNOW MIX AS INITIAL
DRY LLVL AIR AIDS EVAPORATIVE COOLING. ACCUMULATIONS WILL TAPER
OFF FROM AN INCH OVER THE NCNTRL TO A DUSTING TO THE SOUTH...IF THE
GROUND ISN/T TOO WARM THERE.
BEHIND THE SHORTWAVE...THERE WILL LIKELY BE A 6-12HR GAP IN THE PCPN
BEFORE THE LAKE EFFECT PCPN PICKS UP THURS AFTN WHEN THE -5C H850
TEMPS ARRIVE AND FALL TO -7C ON THURS NIGHT. THE COOL WATER TEMPS
OVER WRN LAKE SUPERIOR PUTS THE WRN CWA UNDER MARGINAL DELTA-T
VALUES...BUT THE EAST SHOULD STILL SEE FAVORABLE VALUES. DRY MID LVL
AIR WILL SURGE IN BEHIND THE SHORTWAVE AND HELP INHIBIT CLOUD DEPTH
UNTIL IT SLIDES SOUTH ON THURS NIGHT. WITH THE LIMITED CONDITIONS
OVER THE WEST...WILL ONLY GO SLIGHT/CHANCES OVER THE WEST AND HIGH
CHANCES AND LIKELY/S OVER THE EAST FOR LOCATIONS FAVORED BY NW
WINDS.
HIGH PRESSURE WILL BUILD OVER THE GREAT LAKES REGION ON
FRIDAY...BRINGING AN END TO THE LAKE EFFECT PCPN QUICKLY IN THE
MORNING. FRIDAY WILL LIKELY BE THE NICEST DAY OF THE WEEK...WITH
PARTLY/MOSTLY SUNNY SKIES AND TEMPERATURES IN THE UPPER 40S.
ATTENTION THEN TURNS TO THE WEEKEND SYSTEM. THINGS STILL SEEM TO BE
ON TRACK WITH THE SURFACE LOW TRACKING ACROSS UPPER MICHIGAN ON
SATURDAY NIGHT...ALTHOUGH THE LATE ARRIVING 12Z ECMWF HAS PUSHED
THE LOW A LITTLE FARTHER SE. WITH THE TRACK OF THE SYSTEM AND THE
MOISTURE BROUGHT UP FROM THE SW...LATEST INDICATIONS ARE FOR A
WIDESPREAD 0.75 PLUS OF RAIN ACROSS UPPER MICHIGAN. THE ONLY THING
THAT COULD CAUSE ISSUES WITH PCPN AMNTS AT THIS TIME WOULD BE THE
DRY SLOT THAT TRIES TO SURGE NE INTO THE SCNTRL CWA ON SAT NIGHT AS
THE LOW MOVES DIRECTLY OVERHEAD.
HIGH PRESSURE WILL MOVE IN BEHIND THE LOW ON SUNDAY NIGHT INTO
MONDAY...BEFORE THE NEXT SHORTWAVE ARRIVES ON MONDAY NIGHT AND
TUES. TEMPS SHOULD CLIMB BACK TO MORE NORMAL VALUES THIS WEEKEND
INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 136 PM EDT TUE OCT 9 2012
PER REGIONAL RADARS...BAND OF -RA IS STREAKING NE INTO UPPER MI
ATTM. KSAW WILL BE MOST AFFECTED...AND EXPECT A PERIOD OF MVFR
CONDITIONS THERE THIS AFTN AS STEADIER/HEAVIER PCPN PASSES.
KIWD/KCMX ARE ON THE WRN FRINGE OF PCPN AND SHOULD REMAIN VFR THOUGH
CIGS MAY BRIEFLY DROP TO MVFR AT TIMES. AS COLDER AIR PUSHES INTO
THE AREA TONIGHT...INCREASING INSTABILITY OVER THE LAKE WILL RESULT
IN MVFR CIGS/LAKE EFFECT -SHRA THAT MIX WITH/CHANGE TO -SN
OVERNIGHT...MAINLY AT KIWD/KCMX WITH UPSLOPE WIND COMPONENT.
DOWNSLOPE NATURE OF THE WNW FLOW AT KSAW WILL LIKELY PREVENT ANY
SIGNIFICANT PCPN AND MAKE VFR CIGS A GREATER POSSIBILITY THAN AT
KIWD/KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EDT TUE OCT 9 2012
COLD FRONT/TROF WILL PUSH ACROSS LAKE SUPERIOR TONIGHT. WINDS IN
GENERAL WILL REMAIN IN THE 20-30KT RANGE...BUT AFTER THE COLD FRONT
PASSES...COLDER AIR WILL RESULT IN INCREASING OVERWATER INSTABILITY
AND DEEPER MIXING. ALONG WITH INCREASED MIXING...PRES RISES
APPROACHING FROM THE NW MAY HELP PUSH WIND GUSTS TO GALE FORCE AT
TIMES OVERNIGHT THRU WED MORNING FROM NCNTRL INTO SCNTRL/SE LAKE
SUPERIOR.
AN UPPER LEVEL DISTURBANCE AND LOW PRESSURE SYSTEM WILL SLIDE EAST
ACROSS LAKE SUPERIOR LATE WEDNESDAY NIGHT AND THURSDAY. BEHIND THIS
LOW...EXPECT NORTHWEST WINDS TO INCREASE ON THURSDAY TO
30KTS...WITH A FEW GALE FORCE GUSTS TO 35KTS OVER THE EAST HALF IN
THE AFTERNOON. HIGH PRESSURE WILL THEN MOVE ACROSS LAKE SUPERIOR ON
FRIDAY AND DECREASE WINDS BELOW 20KTS. THE NEXT LOW PRESSURE SYSTEM
WILL MOVE OUT OF THE CENTRAL PLAINS ON FRIDAY NIGHT AND ACROSS
UPPER MICHIGAN ON SATURDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON/SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
137 PM EDT TUE OCT 9 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EDT TUE OCT 9 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW MEAN UPR TROF
STILL DOMINATING ERN NAMERICA DOWNSTREAM OF UPR RDG OFF THE W COAST
OF CANADA. TWO DISTURBANCES OF NOTE ARE EMBEDDED IN THIS TROF. THE
FIRST IS CURRENTLY MOVING THRU THE UPR GRT LKS...WITH 999MB SFC LO
OVER ONTARIO. AT 06Z...ATTENDANT COLD FNT IS PUSHING INTO THE WRN
CWA...PRECEDED BY A BAND OF SCT -SHRA STRETCHING FM JUST E OF THE
KEWEENAW SWWD INTO NCENTRAL WI. STRONG S WINDS ARE EVIDENT UNDER THE
SHARPER PRES GRADIENT TO THE E AS 00Z GRB RAOB INDICATED WINDS UP TO
39KTS AS LO AS 2K FT AGL AND UNSTABLE LLVL LAPSE RATES. THE WINDS
ARE STRONGEST AT EXPOSED LOCATIONS NEAR LK MI...WHERE WINDS GUSTED
AS HI AS 45-55 MPH AT SEVERAL SITES YDAY EVNG. WHILE THE DRYNESS OF
THE SUB H8 LYR SHOWN ON THE 00Z GRB RAOB RESTRICTED PCPN COVERAGE/
AMOUNTS OVER MUCH OF THE CWA AHEAD OF THE COLD FNT...MORE SHRA ARE
NOTED OVER THE ERN CWA WHERE THE S WIND UP THE LENGTH OF LK MI
ALLOWED SUFFICIENT MOISTENING TO OVERCOME THIS LLVL DRY AIR. BUT
THIS PCPN IS TENDING TO DRIFT INTO FAR ERN UPR MI AND OUT OF THE MQT
CWA. TO THE W...THERE IS PARTIAL CLRG OVER MUCH OF CENTRAL AND SRN
MN BEHIND THE COLD FROPA AS DRIER AIR SHOWN ON THE 00Z MPX RAOB
ADVECTS TO THE ENE. BUT MORE HI AND MID CLDS ASSOCIATED WITH A
STRONGER SECOND SHRTWV DROPPING SEWD INTO THE NRN PLAINS ARE
SPREADING TO THE E THRU MN AT THE SAME TIME. THE APRCH OF THIS
SHRTWV IS ALSO CAUSING A GREATER COVERAGE OF -SHRA ON THE SRN EDGE
OF THE COLD FNT OVER SE MN/NRN IOWA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE WHETHER TO ALLOW CURRENT
WIND ADVY FOR THE ERN CWA TO EXPIRE AS SCHEDULED AT 09Z AND EVENTUAL
-RA COVERAGE ASSOCIATED WITH STRONGER SECOND SHRTWV NOW DIGGING INTO
THE NRN PLAINS.
EARLY THIS MRNG...AS SHRTWV/SFC LO TO THE N MOVE TO THE NE...COLD
FNT EXTENDING S THRU UPR MI WL SHIFT TO THE E BUT TEND TO SLOW DOWN
AS SECOND SHRTWV DIGGING THRU THE NRN PLAINS DEEPENS THE UPR TROF
AXIS TO THE W AND THE FLOW ALF BACKS TO MORE SW OVER THE GREAT
LAKES. THE BAND OF -SHRA PRECEDING THE FNT WL LIKELY DRY OUT A BIT
WITH BEST FORCING EXITING TO THE NE AND LLVL DRY AIR LINGERING W OF
LIMITING STREAMLINE OFF LK MI. BUT MOISTENING OFF LK MI MIGHT ALLOW
FOR SOME EHNANCEMENT TO THE COVERAGE AGAIN ONCE THE BAND REACHES
THAT AREA. WITH THE CLOSER APRCH OF THE COLD FNT...THE PRES GRADIENT
OVER THE E WL WEAKEN SUFFICIENTLY TO ALLOW THE STRONGER S WINDS TO
DIMINISH BEFORE 12Z. SO PLANNED EXPIRATION OF WIND ADVY AT 09Z SEEMS
TO BE ON TRACK. OVER THE W...DRYING ALF WL BRING DRY WX FOR THE MOST
PART.
TODAY...AS THE UPR TROF AXIS DEEPENS TO THE W IN RESPONSE TO DIGGING
SECOND SHRTWV...EXPECT AREA OF SHRA NOW ON COLD FNT TO THE S TO
EXPAND AND MOVE NE. LATEST MODEL RUNS SHOW CONSIDERABLE SPREAD ON
WHERE AREA OF SHRA WL IMPACT. THE 00Z LOCAL WRF-ARW/CNDN MODELS ARE
FARTHEST W WITH THE TRACK OF THE HEAVIER PCPN...WHILE THE 00Z NAM IS
FARTHEST TO THE E AND IN LINE WITH CURRENT FCST. CONSIDERING THE
TRENDS ON THE INCOMING DRYING TO THE W BEHIND THE COLD FNT AS WELL
AS FCST SHARPEST H85-5 QVECTOR CNVGC OVER THE E THIS AFTN...TEND TO
THINK THE NAM IS ON THE RIGHT TRACK. THE SHARPEST H85-7 FGEN IS ALSO
OVER THE E. ON THE OTHER HAND...SINCE THE FRONTAL SLOPE WL BE RATHER
FLAT...SOME SHARP H7-5 FGEN/H7-3 QVECTOR CVNGC/H4-2 DVGC IS EVIDENT
FARTHER W AND OVER THE WRN CWA. SO EVEN IF THE HEAVIER PCPN DOES
FALL TO THE E...SUSPECT THERE WL BE AT LEAST SOME SCT -SHRA OVER THE
W...WHERE THE HIER DYNAMICS WL HAVE TO OVERCOME MORE LLVL DRYING. AS
THE SHRTWV/DYNAMIC SUPPORT SHIFTS TO THE NE LATER IN THE DAY...
EXPECT THE POPS TO DIMINISH...LATEST OVER THE E. WITH PLENTY OF CLD
COVER AND A GRADUAL INFLUX OF COOLER AIR...EXPECT LTL DIURNAL RISE
IN TEMPS.
TONIGHT...IN THE WAKE OF THE DEPARTING SHRTWV...A CYC NW LLVL FLOW
WL ADVECT A CHILLY CNDN AIRMASS INTO THE UPR LKS. WITH H85 TEMPS
FALLING AS LO AS -7C/-5C OVER WRN/ERN LK SUP BY 12Z /COMPARED WITH
WATER TEMPS OF 7C AT THE WRN BUOY AND 11C AT THE ERN BUOY/...
OVERWATER INSTABILITY WL BECOME SUFFICIENT FOR LK EFFECT -SHRASN TO
IMPACT AREAS FAVORED BY THE LLVL NW FLOW...ESPECIALLY SINCE DEEPER
MSTR WL EXTEND TO THE DGZ. BUMPED POPS UP IN THESE AREAS ABV MODEL
GUIDANCE. WOULD NOT BE SURPRISED TO SEE 1 TO 2 INCHES OF SNOW ACCUM
OVER THE HIER TERRAIN IN AREAS FAVORED BY NW FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR THEME OF INCREASED WIND WITH SYSTEMS ROLLING THROUGH EVERY
COUPLE OF DAYS WILL CONTINUE FOR THE FORESEEABLE FUTURE.
WEDNESDAY...
THE LARGE SCALE TROUGH OVER MUCH OF THE NATION WILL BE CENTERED
ACROSS THE UPPER GREAT LAKES AT 12Z WEDNESDAY...EDGING E THROUGH THE
DAY...WITH NW FLOW RULING THE AREA. WITH NW FLOW AT THE SFC AND
ALOFT...EXPECT COOL AIR TO REMAIN IN PLACE /850MB TEMPS OF -6 TO
-8C/...WITH UPSLOPE LAKE EFFECT SHOWER ACTIVITY. SNOW WILL LIKELY
MIX IN ACROSS W PORTIONS OF THE CWA BEFORE TEMPS WARM TO NEAR 40F
AND WINDS TURN A BIT MORE WESTERLY. ANY ADDITIONAL SNOW WEDNESDAY
SHOULD TOTAL AROUND A HALF AN INCH OR LESS...AS THE INCOMING SFC
RIDGE HELPS TO SCOUR OUT SOME OF THE LOW LEVEL MOISTURE.
WEDNESDAY NIGHT THROUGH FRIDAY...
THE NEXT CLIPPER-LIKE LOW WILL SLIDE IN FROM THE NORTHWEST LATE
WEDNESDAY NIGHT INTO THURSDAY...MOVING DIRECTLY OVER LAKE SUPERIOR
AT 12Z THURSDAY. AFTER 850MB TEMPS JUMPING UP TO AROUND 0C ON
INCREASED SW WINDS...THEY SHOULD AGAIN FALL TO -6 TO -7C THURSDAY
AFTERNOON. LIKE BEFORE...ANOTHER RIDGE OF HIGH PRESSURE WILL PUSH
IN...DRYING US OUT THURSDAY NIGHT AND FRIDAY. THIS TIME THE SFC HIGH
WILL MOVE OVER OR JUST S OF THE AREA /ACROSS WI AND LAKE MI FRIDAY
AFTERNOON/...WITH MUCH LIGHTER WINDS AT LEAST TEMPORARILY.
FRIDAY NIGHT THROUGH MONDAY...
THE HIGH WILL QUICKLY SLIDE TO THE LOWER GREAT LAKES FRIDAY
NIGHT...AS LOW PRESSURE ORGANIZES OFF THE ROCKIES. THE STRENGTHENING
LOW WILL SLIDE IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING
MUCH WARMER AIR ON STRONG SOUTHERLY WINDS...AND THE POTENTIAL FOR
MODERATE TO HEAVY RAIN...BEFORE EXITING NORTHEAST ON SUNDAY. FCST
MODELS HAVE BEEN FAIRLY CONSISTANT ON THE TRACK OF THE LOW OVER
UPPER MI...SO HAVE INCREASED POPS TO 80 PERCENT OR BETTER SATURDAY
AND SATURDAY NIGHT OVER CENTRAL AND E AREAS...AS WELL AS ADDED A
NON-DIURNAL TEMP TREND SATURDAY NIGHT /PARTICULARLY E WITH THE
CONTINUED S WINDS OFF LAKE MI/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 136 PM EDT TUE OCT 9 2012
PER REGIONAL RADARS...BAND OF -RA IS STREAKING NE INTO UPPER MI
ATTM. KSAW WILL BE MOST AFFECTED...AND EXPECT A PERIOD OF MVFR
CONDITIONS THERE THIS AFTN AS STEADIER/HEAVIER PCPN PASSES.
KIWD/KCMX ARE ON THE WRN FRINGE OF PCPN AND SHOULD REMAIN VFR THOUGH
CIGS MAY BRIEFLY DROP TO MVFR AT TIMES. AS COLDER AIR PUSHES INTO
THE AREA TONIGHT...INCREASING INSTABILITY OVER THE LAKE WILL RESULT
IN MVFR CIGS/LAKE EFFECT -SHRA THAT MIX WITH/CHANGE TO -SN
OVERNIGHT...MAINLY AT KIWD/KCMX WITH UPSLOPE WIND COMPONENT.
DOWNSLOPE NATURE OF THE WNW FLOW AT KSAW WILL LIKELY PREVENT ANY
SIGNIFICANT PCPN AND MAKE VFR CIGS A GREATER POSSIBILITY THAN AT
KIWD/KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND...WITH
ANOTHER SYSTEM SLIDING IN FOR THE WEEKEND. EXITING LOW PRESSURE JUST
NORTH OF LS WILL SWEEP A TROUGH ACROSS CENTRAL AND EASTERN LS
TODAY...WITH A COOLER SECONDARY TROUGH ROTATING THROUGH TONIGHT. THIS
WILL BRING NORTHWESTERLY WINDS BACK TO THE REGION THROUGH EARLY
WEDNESDAY /WITH SOME NW GALE FORCE GUSTS TO 35 KTS WEDNESDAY ACROSS E
LS/. AFTER A QUICK RIDGE PUSHES IN...THE NEXT LOW WILL SLIDE IN FROM
THE NW LATE WEDNESDAY NIGHT INTO THURSDAY /WITH W GUSTS AGAIN OF
30-35KTS THURSDAY INTO THURSDAY EVENING/...BEFORE HIGH PRESSURE MOVES
OVERHEAD WITH TEMPORARILY LIGHTER WINDS FRIDAY. A STRENGTHENING LOW
WILL PUSH IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING STRONGER
SOUTHERLY WINDS BEFORE EXITING NE OF LS ON SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
348 PM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL SHIFT INTO EASTERN CANADA
TONIGHT...AS A SURFACE COLD FRONT APPROACHES THE SAINT LAWRENCE
VALLEY BY WEDNESDAY. THIS COLD FRONT WILL PRODUCE A BRIEF PERIOD OF
SHOWERS FROM WEST TO EAST ACROSS THE AREA ON WEDNESDAY INTO
WEDNESDAY EVENING...ALONG WITH BREEZY SOUTHERLY WINDS. THESE WINDS
WILL SHIFT TO THE WEST AND COOLER TEMPERATURES WILL ARRIVE BY
THURSDAY. A SECONDARY COLD FRONT WILL PRODUCE MORE LIGHT SHOWERS ON
FRIDAY...WITH SOME HIGH ELEVATION SNOW SHOWERS POSSIBLE...WITH EVEN
COOLER TEMPERATURES AND WIDESPREAD FROST EXPECTED ON SATURDAY
MORNING.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 350 PM EDT TUESDAY...FCST CHALLENGE WL BE TIMING OF FROPA
AND ASSOCIATED POPS/QPF ON WEDS AFTN/EVENING. WATER VAPOR SHOWS
SMALL ENVELOPE OF DRY AIR ACRS OUR CWA THIS AFTN...ASSOCIATED WITH
SUBSIDENCE FROM SYSTEM WELL OFF THE COAST..WITH NEXT RIBBON OF
ENHANCED MOISTURE/VORT DIVING TWD THE CENTRAL GREAT LAKES ATTM.
WEAK PRE-FRNTAL VORT AND RIBBON OF MOISTURE WL LIFT ACRS OUR
WESTERN/CENTRAL CWA THIS EVENING...WITH LLVL ATLANTIC MOISTURE
ADVECTING AROUND HIGH PRES IMPACTING OUR CENTRAL/EASTERN CWA.
PATCHY DRIZZLE/VERY LIGHT RAIN WL BE POSSIBLE ACRS OUR EASTERN ZNS
MTNS TONIGHT. CLOUD GRIDS AND ASSOCIATED TEMPS WL BE TRICKY
TONIGHT. RUC13 925MB TO 700MB RH PROGS SHOW PLENTY OF MOISTURE
ALONG AND EAST OF THE GREEN MTNS THRU THIS EVENING...THEREFORE WL
MENTION MOSTLY CLOUDY SKIES AND KEEP TEMPS IN THE 40S...MAYBE A
FEW 30S NORTHERN ZNS. ELSEWHERE...SKIES SHOULD BE PC WITH TEMPS IN
U30S DACKS TO 40S CPV/SLV.
FOR WEDNESDAY...POTENT S/W ENERGY AND ASSOCIATED ENHANCED RIBBON OF
MID LVL RH WL ENTER THE SLV AROUND 16Z...BE ACRS THE DACKS BTWN
18Z-20Z...CPV AROUND 21Z...AND THRU VT BY 02Z THURS. NAM12 SHOWS
GOOD 925MB FGEN FORCING...GOOD 850 TO 700MB RH/OMEGA FIELDS...AND
PWS VALUES NEAR 0.75"...WHICH WL RESULT IN A 1 TO 3 HR WINDOW OF
SHOWERS. FAST MOVEMENT OF SYSTEM AND LIMITED DEEP LAYER MOISTURE
ADVECTION WL KEEP QPF AMOUNT GENERALLY <0.25"...WITH HIGHEST VALUES
ACRS THE MTNS. HIGH RESOLUTION MODELS SHOW SOME CHANNELING EFFECTS
ACRS THE SLV/CPV WITH LOCALIZED WIND GUSTS BTWN 30 AND 35 MPH
POSSIBLE. PROGGED 85H SOUTHWEST FLW OF 35 TO 40 KNTS AHEAD OF SYSTEM
WL LIMIT QPF/POP CHCS ACRS THE CPV ON WEDS. WL TREND TEMPS SEVERAL
DEGREES ABOVE GUIDANCE GIVEN SOUTHERLY FLW AND PROGGED 925MB TEMPS
NEAR 11C. THINKING M50S MTNS TO M60S VALLEYS...WITH WARMEST READINGS
AT VSF.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 350 PM EDT TUESDAY...MID/UPPER LVL TROF DEEPENS BEHIND SFC
COLD FRNT...BUT STRONG SFC PRES GRADIENT BTWN HIGH PRES ACRS THE
OHIO VALLEY AND DEPARTING LOW PRES WL KEEP TEMPS FROM DROPPING TOO
FAR. GIVEN...A WEST TO NORTHWEST FLW BTWN 925MB AND
850MB...THINKING BEST LAKE EFFECT MOISTURE WL STAY SOUTH OF OUR
CWA ON WEDS NIGHT. THE COMBINATION OF UPSLOPE NW FLW AND LEFTOVER
850 TO 700MB RH...MAY PRODUCE A FEW MTN FLURRIES/SNOW SHOWERS ON
WEDS NIGHT...AS 85H TEMPS COOL BLW 0C. GFS SOUNDINGS AT JAY PEAK
SHOW THIS POTENTIAL...WITH A DUSTING OF SNOW POSSIBLE BY THURS
MORNING FROM SUGARBUSH TO MOUNT MANSFIELD TO JAY PEAK. SOUNDINGS
SHOW WELL MIXED BL WITH CAA ACRS OUR CWA...WL MENTION LOWS FROM
THE U20S MTNS TO U30S VALLEYS AND L40S NEAR LAKE CHAMPLAIN.
ON THURSDAY...SFC RIDGE AXIS MOVES ACRS OUR CWA BY 18Z...WITH RETURN
SOUTHWEST FLW DEVELOPING BY 00Z FRIDAY. BOTH GFS/NAM SHOW ENHANCED
850 TO 500MB RH IMPACTING THE SLV BY 18Z THURS AND SPREADING TWD THE
CPV BY 00Z FRIDAY...ASSOCIATED WITH LOW TO MID WAA AHEAD OF NEXT
SYSTEM. THIS FAST MOVING CLIPPER LIKE SYSTEM WL PUSH ACRS OUR CWA
THUR NIGHT INTO FRIDAY MORNING. THIS NORTHERN STREAM SYSTEM WL HAVE
LIMITED MOISTURE...BUT GIVEN STRONG DYNAMICS AND GOOD SFC
CONVERGENCE...EXPECT ANOTHER BRIEF PERIOD OF SHOWERS OVERNIGHT INTO
FRIDAY MORNING..WITH HIGHEST POPS/QPF CONCENTRATED ACRS THE MTNS.
MUCH COOLER TEMPS ARRIVE ON FRIDAY INTO SATURDAY BEHIND THIS SYSTEM.
FOR THURSDAY...PROGGED 85H TEMPS WARM TO NEAR 0C...BUT INCREASE
CLOUDS MAY LIMIT SFC HEATING/MIXING...THINKING U40S NEK TO NEAR 60F
CPV/SLV. THE COMBINATION OF SOUTHERLY SFC WINDS FROM APPROACHING
BOUNDARY...INCREASING CLOUDS/PRECIP...AND WARMING LLVL THERMAL
PROFILES ON THURS NIGHT...WL MENTION LOWS ABOVE GUIDANCE AND MAINLY
IN THE 40S. HOWEVER...TWD FRIDAY MORNING LLVL CAA DEVELOPS AND
THERMAL PROFILES ABOVE 2000 FT WL BECM COLD ENOUGH TO SUPPORT SOME
SNOW. HAVE MENTION A MIX OF RAIN/SNOW WITH SOME LIGHT ACCUMULATION
POSSIBLE ABOVE 3000 FT AROUND 12Z FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 326 PM EDT TUESDAY...UPPER TROUGH SWINGS THRU THE CWA DURING
THE DAY ON FRIDAY. MDLS CONTINUE TO SHOW SFC RIDGE BUILDING OVER
THE NORTH COUNTRY FRI NGT INTO SATURDAY. SATURDAY NIGHT HAS WARM
FRNTL BOUNDARY SWING THRU THE WESTERN PORTIONS OF THE
CWA...OVERSPREADING THE ENTIRE CWA SLOWLY ON SUNDAY. SFC LOW
ASSOCIATED WITH FRNT LIFTS NORTH OF CWA TRAVELING EAST THRU QUEBEC
INTO MONDAY. TIMING ISSUES WITH EXITING SYSTEM ON MONDAY INTO
TUESDAY AS LATEST ECMWF DIGS UPPER TROUGH FURTHER SOUTH. THIS WILL
POTENTIALLY KEEP PRECIP LONGER OVER THE AREA...WHILE THE LATEST
GFS BRINGS DRIER AIR WITH RIDGE FROM GREAT LKS REGION.
IMPACTS FOR THE NORTH COUNTRY...
FRIDAY...MOST OF THE REGION WILL SEE LGT -RW...EMPHASIS WILL BE OVER
HIR TRRN AS PRECIP TAPERS OFF WITH WNW FLOW OVER THE AREA. SOME --SW
POSSIBLE AT 1500-2000` OR HIR FOR A FEW HRS IN THE MORNING...BECM
ALL -RW BFR ENDING.
FRIDAY NIGHT THRU SATURDAY...CWA WILL RADIATE OUT UNDER CLR SKIES
FRI NGT ALLOWING FOR TEMPS TO DROP INTO THE TEENS AND 20S CWA-WIDE.
COLDER TEMPS IN THE HILLS OF DACKS NE VT. RIDGE SHIFTS EAST DURING
THE DAY SATURDAY ALLOWING FOR WARM UP WITH HGHS INTO THE MID50S AS
SSW FLOW INCR AHEAD OF APPROACHING WARM FRNT.
SATURDAY NIGHT THRU TUESDAY...LGT PRECIP/CLDS INCR OVER N NY SAT NGT
OVERSPREADING CWA BY SUNDAY MORNING. POSITIONING OF WARM FRNT ON
GFS/ECMWF EXTENT OF ANY -SW THAT DEMELOP OVE RHIR TRRN BFR GOING TO
ALL -RW. SYSTEM SLIDES SLOWLY EAST THRU SUN/SUN NGT AS PARENT LOW
SHIFTS INTO SOUTHERN QUEBEC. WILL KEEP CHANCE FOR -RW OVER AREA
THRU PERIOD. LATE SUNDAY NIGHT INTO MONDAY W/ FRNT LIFTING N OF
CWA...PRECIP WILL SCT OUT SOME AS DRIER AIR WORKS INTO AREA. WILL BE
KEEPING CHANCE POPS FOR -RW TRANSITIONING TO LGT -SW OVER HIR AS CD
AIR FILTERS INTO AREA UNDER NW. FOR NOW WITH MDL UNCERTAINTY HAVE
KEPT SL CHANCE FOR TUESDAY FOR SHOWERS.
TEMPS FOR THE EXTENDED BLW NORMAL BY A FEW DEGREES WITH RIDGE
OVERHD...AND INCR TO AT OR ABV NORMAL CONDITIONS DUE TO WARMER
AIRMASS WORKING INTO AREA W/ FRNT.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
THROUGH 18Z WEDNESDAY...MAINLY VFR COND AS REGION REMAINS UNDER
HIGH PRESSURE. CEILINGS WILL RANGE FROM BKN035-060. SLK/MPV/RUT
WILL SEE MVFR MIX IN BY 04Z-05Z W/ TEMPO CEILINGS DROPPING DOWN TO
BKN020-030 AT TIMES. WINDS SSW AROUND 10KTS BECM LGT/VAR BY 00Z
WED...THEN SSW 10-20KTS FROM 07Z-15Z FROM WEST TO EAST.
OUTLOOK 18Z WEDNESDAY THROUGH SATURDAY...
18Z WEDNESDAY THROUGH 12Z THURSDAY...A COLD FRONT WILL MOVE INTO
THE REGION ON WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT WITH
SCATTERED SHOWERS ALONG WITH SOME AREAS OF MVFR.
12Z THURSDAY THROUGH 00Z FRIDAY...MAINLY VFR AS A RIDGE OF HIGH
PRESSURE WILL BE OVER THE REGION.
00Z FRIDAY THROUGH 18Z FRIDAY...TRENDING BKN/OVC VFR WITH SOME
MVFR IN SCATTERED SHOWERS WITH COLD FRONTAL PASSAGE.
18Z FRIDAY THROUGH 18Z SUNDAY...TRENDING VFR AS A RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...JN
AVIATION...KGM/JN