Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/17/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1258 PM MST THU NOV 15 2012
.UPDATE...STRATUS DECK GRADUALLY BREAKING UP. CLOUDS WILL BE MOST
PERSISTENT AGAINST THE FOOTHILLS FROM BOULDER TO FORT COLLINS BUT
EVEN THERE SHOULD CLEAR BY LATE AFTERNOON.
&&
.AVIATION...SOME STRATOCUMULUS HAD DEVELOPED WHERE CEILINGS HAD
BROKEN UP AT KDEN...ENOUGH FOR TEMPO BROKEN NEAR 4000 FT AGL TIL
21Z-22Z. MEANWHILE...KAPA SHOULD ONLY SEE SCT CLOUDS...WHILE KBJC
SHOULD FINALLY SEE ORIGINAL STRATUS DECK BREAK UP AROUND 22Z.
OTHERWISE VISUAL LANDING CONDITIONS WILL PREVAIL THROUGH FRIDAY
WITH LIGHT WINDS.
&&
.PREV DISCUSSION... /ISSUED 751 AM MST THU NOV 15 2012/
UPDATE...
SHORT TERM...CLOUD DECK HAS BECOME MORE EXTENSIVE OVER THE PLAINS
THIS MORNING AND EVEN LIGHT SNOW AND FLURRY BAND HAS SAGGED A BIT
FURTHER SOUTH INTO BOULDER AND NORTHERN JEFFERSON COUNTY. DON`T
EXPECT ANY ACCUMULATION THOUGH EXCEPT SOME DUSTING OVER NORTHERN
WELD COUNTY. CHANGES TO FORECAST INCLUDE MORE CLOUDS AND GRADUAL
CLEARING DURING THE EARLY AFTERNOON. ADDED LIGHT SNOW A BIT
FURTHER SOUTH THAN CURRENT FORECAT.
AVIATION...SOLID STRATUS DECK IN PLACE OVER LOCAL TERMINALS AND
MAY EVEN SEE A FEW FLURRIES AT BJC AND DEN OVER THE NEXT FEW
HOURS. NO ACCUMULATION EXPECTED THOUGH. WILL CONTINUE THE TREND OF
LATER CLEARING AND MAY SEE ILS CONDITIONS AT DEN THROUGH EARLY
AFTERNOON.
PREV DISCUSSION... /ISSUED 717 AM MST THU NOV 15 2012/
UPDATE...
AVIATION...STRATUS DECK HAS BECOME RATHER WIDESPREAD AND IS NOW
COVERING ALL THE LOCAL TERMINALS WITH CEILINGS BETWEEN 2000 AND
4000 FEET AGL. WILL DELAY CLEARING INTO THE 17Z-19Z TIME FRAME
GIVEN LATEST SOUNDINGS AND PER RUC FORECAST.
PREV DISCUSSION... /ISSUED 547 AM MST THU NOV 15 2012/
UPDATE...
AVIATION...
AN AREA OF LOW CLOUDS HAS FORMED ON THE SOUTH SIDE OF THE SHOWER
BAND...PROBABLY DUE TO COOLING FROM THE SHOWER OUTFLOW. CEILINGS
BETWEEN 025 AND 040 LIKELY AT KDEN FOR THE NEXT COUPLE OF
HOURS...IT MAY GET INTO KBJC BUT EXPECT THESE CLOUDS TO NOT MAKE
IT TO KAPA. EXPECT THIS LAYER TO BREAK UP IN THE 14Z-16Z TIME
FRAME AS THE SHOWERS FADE AND THE SURFACE WARMS.
PREV DISCUSSION... /ISSUED 326 AM MST THU NOV 15 2012/
SHORT TERM...LITTLE SNOW BAND IN A WEAK FRONTOLYSIS ZONE THAT
WAS PARKED OVER THE LARAMIE AND CHEYENNE AREAS MOST OF THE NIGHT
HAS STARTED TO SAG SOUTH A BIT AS THE TROUGH AXIS GETS EAST OF
US...BUT IS ALSO STARTING TO FALL APART AND SHRINK AT BOTH THE
EASTERN AND WESTERN ENDS. THIS SHOULD CONTINUE TO DIMINISH AS THE
QG LIFT GOES AWAY AND DRIER AIR UNDERCUTS THE MID LEVEL LIFT.
CURRENT FORECAST HAS THESE SHOWERS ENDING BY 15Z WHICH IS PROBABLY
ALRIGHT...I DID KEEP A FEW SHOWERS IN THE NORTHERN MOUNTAINS LATER
THIS MORNING AS THE CLOUDS ON THE TAIL END OF THE BAND WILL LIKELY
STILL BE OUT THERE. I ALSO SLOWED THE CLEARING ON THE PLAINS JUST
A LITTLE...BUT EXPECT MOST OF THE CLOUDS TO BE GONE BY LATE
AFTERNOON. NO CHANGES TO THE REST OF THE FORECAST...WEAK NORTHERLY
WIND SURGE AND COOLER HIGHS TODAY APPEAR WELL HANDLED.
LONG TERM...NOT MUCH TO CONTEND WITH THROUGH MONDAY. THE FLOW
ALOFT WILL REMAIN SOUTHWESTERLY WITH A SERIES OF WEAK EMBEDDED
DISTURBANCES SLIPPING ACROSS COLORADO. THERE WILL BE ENOUGH
MOISTURE TO PRODUCE A SLIGHT CHANCE OF SNOW IN THE HIGH
COUNTRY...BUT LIMITED MOISTURE AND PREVAILING DOWNSLOPE WILL KEEP
THE LOWER ELEVATION MILD AND DRY. OVERALL...AFTERNOON
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE SEASONAL NORMALS.
AVIATION...VFR CONDITIONS EXPECTED OVER THE DENVER AREA THROUGH
TONIGHT...WITH LIGHT SNOW SHOWERS THIS MORNING REMAINING NORTH OF
DENVER. WITH HIGH PRESSURE SHIFTING OVER THE NORTHERN PLAINS...EXPECT
THE CURRENT WIND PATTERN TO BREAK DOWN WITH NORTH TO NORTHEAST
WINDS DEVELOPING IN THE DENVER AREA BY SUNRISE. WINDS MAY STILL BE
LIGHT AND SOMEWHAT VARIABLE THIS MORNING...BUT BY MIDDAY EXPECT
STEADIER NE-E WINDS THAT WILL ROTATE TO SLY DRAINAGE WINDS THIS
EVENING. EXPECT A DENVER CYCLONE TO DEVELOP TONIGHT SO SOME
UNCERTAINTY ABOUT WIND DIRECTION AT KDEN/KAPA FOR FRIDAY
MORNING...BUT FOG THREAT APPEARS LOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....COOPER
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
751 AM MST THU NOV 15 2012
.UPDATE...
&&
.SHORT TERM...CLOUD DECK HAS BECOME MORE EXTENSIVE OVER THE PLAINS
THIS MORNING AND EVEN LIGHT SNOW AND FLURRY BAND HAS SAGGED A BIT
FURTHER SOUTH INTO BOULDER AND NORTHERN JEFFERSON COUNTY. DON`T
EXPECT ANY ACCUMULATION THOUGH EXCEPT SOME DUSTING OVER NORTHERN
WELD COUNTY. CHANGES TO FORECAST INCLUDE MORE CLOUDS AND GRADUAL
CLEARING DURING THE EARLY AFTERNOON. ADDED LIGHT SNOW A BIT
FURTHER SOUTH THAN CURRENT FORECAT.
.AVIATION...SOLID STRATUS DECK IN PLACE OVER LOCAL TERMINALS AND
MAY EVEN SEE A FEW FLURRIES AT BJC AND DEN OVER THE NEXT FEW
HOURS. NO ACCUMULATION EXPECTED THOUGH. WILL CONTINUE THE TREND OF
LATER CLEARING AND MAY SEE ILS CONDITIONS AT DEN THROUGH EARLY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 717 AM MST THU NOV 15 2012/
UPDATE...
AVIATION...STRATUS DECK HAS BECOME RATHER WIDESPREAD AND IS NOW
COVERING ALL THE LOCAL TERMINALS WITH CEILINGS BETWEEN 2000 AND
4000 FEET AGL. WILL DELAY CLEARING INTO THE 17Z-19Z TIME FRAME
GIVEN LATEST SOUNDINGS AND PER RUC FORECAST.
PREV DISCUSSION... /ISSUED 547 AM MST THU NOV 15 2012/
UPDATE...
AVIATION...
AN AREA OF LOW CLOUDS HAS FORMED ON THE SOUTH SIDE OF THE SHOWER
BAND...PROBABLY DUE TO COOLING FROM THE SHOWER OUTFLOW. CEILINGS
BETWEEN 025 AND 040 LIKELY AT KDEN FOR THE NEXT COUPLE OF
HOURS...IT MAY GET INTO KBJC BUT EXPECT THESE CLOUDS TO NOT MAKE
IT TO KAPA. EXPECT THIS LAYER TO BREAK UP IN THE 14Z-16Z TIME
FRAME AS THE SHOWERS FADE AND THE SURFACE WARMS.
PREV DISCUSSION... /ISSUED 326 AM MST THU NOV 15 2012/
SHORT TERM...LITTLE SNOW BAND IN A WEAK FRONTOLYSIS ZONE THAT
WAS PARKED OVER THE LARAMIE AND CHEYENNE AREAS MOST OF THE NIGHT
HAS STARTED TO SAG SOUTH A BIT AS THE TROUGH AXIS GETS EAST OF
US...BUT IS ALSO STARTING TO FALL APART AND SHRINK AT BOTH THE
EASTERN AND WESTERN ENDS. THIS SHOULD CONTINUE TO DIMINISH AS THE
QG LIFT GOES AWAY AND DRIER AIR UNDERCUTS THE MID LEVEL LIFT.
CURRENT FORECAST HAS THESE SHOWERS ENDING BY 15Z WHICH IS PROBABLY
ALRIGHT...I DID KEEP A FEW SHOWERS IN THE NORTHERN MOUNTAINS LATER
THIS MORNING AS THE CLOUDS ON THE TAIL END OF THE BAND WILL LIKELY
STILL BE OUT THERE. I ALSO SLOWED THE CLEARING ON THE PLAINS JUST
A LITTLE...BUT EXPECT MOST OF THE CLOUDS TO BE GONE BY LATE
AFTERNOON. NO CHANGES TO THE REST OF THE FORECAST...WEAK NORTHERLY
WIND SURGE AND COOLER HIGHS TODAY APPEAR WELL HANDLED.
LONG TERM...NOT MUCH TO CONTEND WITH THROUGH MONDAY. THE FLOW
ALOFT WILL REMAIN SOUTHWESTERLY WITH A SERIES OF WEAK EMBEDDED
DISTURBANCES SLIPPING ACROSS COLORADO. THERE WILL BE ENOUGH
MOISTURE TO PRODUCE A SLIGHT CHANCE OF SNOW IN THE HIGH
COUNTRY...BUT LIMITED MOISTURE AND PREVAILING DOWNSLOPE WILL KEEP
THE LOWER ELEVATION MILD AND DRY. OVERALL...AFTERNOON
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE SEASONAL NORMALS.
AVIATION...VFR CONDITIONS EXPECTED OVER THE DENVER AREA THROUGH
TONIGHT...WITH LIGHT SNOW SHOWERS THIS MORNING REMAINING NORTH OF
DENVER. WITH HIGH PRESSURE SHIFTING OVER THE NORTHERN PLAINS...EXPECT
THE CURRENT WIND PATTERN TO BREAK DOWN WITH NORTH TO NORTHEAST
WINDS DEVELOPING IN THE DENVER AREA BY SUNRISE. WINDS MAY STILL BE
LIGHT AND SOMEWHAT VARIABLE THIS MORNING...BUT BY MIDDAY EXPECT
STEADIER NE-E WINDS THAT WILL ROTATE TO SLY DRAINAGE WINDS THIS
EVENING. EXPECT A DENVER CYCLONE TO DEVELOP TONIGHT SO SOME
UNCERTAINTY ABOUT WIND DIRECTION AT KDEN/KAPA FOR FRIDAY
MORNING...BUT FOG THREAT APPEARS LOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....COOPER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
717 AM MST THU NOV 15 2012
.UPDATE...
&&
.AVIATION...STRATUS DECK HAS BECOME RATHER WIDESPREAD AND IS NOW
COVERING ALL THE LOCAL TERMINALS WITH CEILINGS BETWEEN 2000 AND
4000 FEET AGL. WILL DELAY CLEARING INTO THE 17Z-19Z TIME FRAME
GIVEN LATEST SOUNDINGS AND PER RUC FORECAST.
&&
.PREV DISCUSSION... /ISSUED 547 AM MST THU NOV 15 2012/
UPDATE...
AVIATION...
AN AREA OF LOW CLOUDS HAS FORMED ON THE SOUTH SIDE OF THE SHOWER
BAND...PROBABLY DUE TO COOLING FROM THE SHOWER OUTFLOW. CEILINGS
BETWEEN 025 AND 040 LIKELY AT KDEN FOR THE NEXT COUPLE OF
HOURS...IT MAY GET INTO KBJC BUT EXPECT THESE CLOUDS TO NOT MAKE
IT TO KAPA. EXPECT THIS LAYER TO BREAK UP IN THE 14Z-16Z TIME
FRAME AS THE SHOWERS FADE AND THE SURFACE WARMS.
PREV DISCUSSION... /ISSUED 326 AM MST THU NOV 15 2012/
SHORT TERM...LITTLE SNOW BAND IN A WEAK FRONTOLYSIS ZONE THAT
WAS PARKED OVER THE LARAMIE AND CHEYENNE AREAS MOST OF THE NIGHT
HAS STARTED TO SAG SOUTH A BIT AS THE TROUGH AXIS GETS EAST OF
US...BUT IS ALSO STARTING TO FALL APART AND SHRINK AT BOTH THE
EASTERN AND WESTERN ENDS. THIS SHOULD CONTINUE TO DIMINISH AS THE
QG LIFT GOES AWAY AND DRIER AIR UNDERCUTS THE MID LEVEL LIFT.
CURRENT FORECAST HAS THESE SHOWERS ENDING BY 15Z WHICH IS PROBABLY
ALRIGHT...I DID KEEP A FEW SHOWERS IN THE NORTHERN MOUNTAINS LATER
THIS MORNING AS THE CLOUDS ON THE TAIL END OF THE BAND WILL LIKELY
STILL BE OUT THERE. I ALSO SLOWED THE CLEARING ON THE PLAINS JUST
A LITTLE...BUT EXPECT MOST OF THE CLOUDS TO BE GONE BY LATE
AFTERNOON. NO CHANGES TO THE REST OF THE FORECAST...WEAK NORTHERLY
WIND SURGE AND COOLER HIGHS TODAY APPEAR WELL HANDLED.
LONG TERM...NOT MUCH TO CONTEND WITH THROUGH MONDAY. THE FLOW
ALOFT WILL REMAIN SOUTHWESTERLY WITH A SERIES OF WEAK EMBEDDED
DISTURBANCES SLIPPING ACROSS COLORADO. THERE WILL BE ENOUGH
MOISTURE TO PRODUCE A SLIGHT CHANCE OF SNOW IN THE HIGH
COUNTRY...BUT LIMITED MOISTURE AND PREVAILING DOWNSLOPE WILL KEEP
THE LOWER ELEVATION MILD AND DRY. OVERALL...AFTERNOON
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE SEASONAL NORMALS.
AVIATION...VFR CONDITIONS EXPECTED OVER THE DENVER AREA THROUGH
TONIGHT...WITH LIGHT SNOW SHOWERS THIS MORNING REMAINING NORTH OF
DENVER. WITH HIGH PRESSURE SHIFTING OVER THE NORTHERN PLAINS...EXPECT
THE CURRENT WIND PATTERN TO BREAK DOWN WITH NORTH TO NORTHEAST
WINDS DEVELOPING IN THE DENVER AREA BY SUNRISE. WINDS MAY STILL BE
LIGHT AND SOMEWHAT VARIABLE THIS MORNING...BUT BY MIDDAY EXPECT
STEADIER NE-E WINDS THAT WILL ROTATE TO SLY DRAINAGE WINDS THIS
EVENING. EXPECT A DENVER CYCLONE TO DEVELOP TONIGHT SO SOME
UNCERTAINTY ABOUT WIND DIRECTION AT KDEN/KAPA FOR FRIDAY
MORNING...BUT FOG THREAT APPEARS LOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GIMMESTAD
LONG TERM....COOPER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1025 AM EST THU NOV 15 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE CANADIAN MARITIMES BUILDS EAST INTO THE
NORTH ATLANTIC LATER TODAY. ANOTHER STRONG AREA OF HIGH PRESSURE
APPROACHES FROM THE WEST ON FRIDAY. THE HIGH BUILDS TO THE NORTH
OF THE AREA OVER THE WEEKEND. A BROAD AREA OF LOW PRESSURE WILL
THEN DEVELOP OFF THE SOUTHEAST COAST LATE IN THE WEEKEND AND
TRACKS NORTHEAST WELL OFFSHORE INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUD COVER IS THE FORECAST ISSUE OF THE DAY. FIRST...VARIABLE AMOUNTS OF
CIRRUS IN THE SOUTHWEST FLOW THROUGH THE DAY. BASED ON TRENDS
LATEST RAP SOUNDING...A GENERAL THICKENING OF THE CIRRUS IS
FORECAST THROUGH THE DAY. SECOND...IS A LAYER OF STRATOCU OVER
LONG ISLAND AND EASTERN CT. THIS LAYER SHOULD STAY IN PLACE
THROUGH THE DAY...THOUGH IT MAY SLIDE SLIGHTLY TO THE WEST THROUGH
THE DAY. THUS...GOING WITH A CLOUDY DAY EAST AND A PARTLY SUNNY
DAY WEST.
OTHERWISE...TEMPS WERE ADJUSTED SLIGHTLY LOWER AND KEPT IN THE
40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
HIGH PRESSURE REMAINS SITUATED TO THE NORTH AND WEST...WHILE A
SHORT WAVE TROF AND DISSIPATING COLD FRONT PUSH ACROSS THE GREAT
LAKES AND EASTERN CANADA TONIGHT. THE LATTER OF WHICH DISSIPATES
WELL TO THE NORTH AND WEST OF THE AREA. A MUCH STRONGER AREA OF
HIGH PRESSURE APPROACHES FROM THE UPPER MIDWEST ON FRIDAY. A
DRY...NORTHERLY FLOW WILL CONTINUE ON FRI WITH TEMPERATURES
WARMING UP INTO THE LOWER 50S...WHICH IS NEARLY SEASONABLE. UPPER
LEVEL CLOUDS MAY CONTINUE TO IMPACT THE REGION...ESPECIALLY FOR
THE FIRST HALF OF THE DAY.
FOLLOWED THE MOS GUIDANCE CLOSELY FOR BOTH THE MORNING LOWS AND AFT
HIGHS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
FAIRLY PERSISTENT AND QUIET PATTERN IN PLACE THROUGH THE LONG TERM
OUTSIDE OF A LOW POTENTIAL FOR A COASTAL SYSTEM EARLY NEXT WEEK.
BROAD AREA OF HIGH PRESSURE OVER MUCH OF THE EASTERN SEABOARD STAYS
IN PLACE THROUGH THE PERIOD KEEPING TEMPERATURES NEAR NORMAL AND A
PERSISTENT NORTH TO NORTHEAST FLOW ACROSS THE REGION. INTO SUNDAY
AND MONDAY...THE ZONAL FLOW SPLITS WITH THE SOUTHERN STREAM DIGGING
INTO THE SOUTHEAST STATES AS THE NORTHERN STREAM MOVES THROUGH
SOUTHERN CANADA. AS THE SOUTHERN STREAM DIPS INTO THE
SOUTHEAST...MODELS INDICATING IT CUTS OFF NEAR THE SE COAST...ON
SUNDAY WITH THE GFS/NAM AND INTO MONDAY WITH THE ECMWF. THIS IS THE
FORCING FOR THE COASTAL LOW DEVELOPMENT THAT TRACKS NORTHEAST.
THERE IS STILL A LOW POSSIBILITY OF A COASTAL STORM DEVELOPING
EARLY NEXT WEEK. HOWEVER...ALL GLOBAL MODELS HAVE BEEN TRENDING EAST
WITH THE SURFACE LOW PRESSURE THROUGH THE LAST FEW RUNS AND HAVE
CONTINUED TO SHOW STRONG HIGH PRESSURE TO OUR NORTH. 18Z GFS/GEFS
AND THE 00Z ECMWF ALL DEVELOP A VERY WEAK SURFACE LOW OFF THE EAST
COAST AND KEEPS IT WELL OFFSHORE. 00Z GFS ALSO SHOWS THIS WEAK LOW
FOR EARLY IN THE WEEK BUT THEN ALSO DEVELOPS ANOTHER SURFACE LOW
AROUND THURSDAY...ALSO KEEPING THAT WELL OFFSHORE. SINCE THIS IS THE
FIRST SET OF MODEL RUNS SHOWING SOME CONSISTENCY WITH THE WEAKER
LOW...HAVE NOT COMPLETELY REMOVED THE POPS AND GUSTY WINDS FROM THE
FORECAST FOR THE MON THROUGH WED TIME FRAME. OUTSIDE OF THIS SLIGHT
SCALE DOWN IN WINDS/POPS...LITTLE CHANGES WERE MADE TO THE EXTENDED
FORECAST FROM THE PREVIOUS ONE.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE CENTERED OVER EASTERN CANADA WEAKENS LATE TODAY AND
THIS EVENING...THEN IS REPLACED BY STRONGER HIGH PRESSURE BUILDING
TO THE WEST LATE TONIGHT.
MARGINAL VFR CEILINGS WITH STRATO CU HAVE DEVELOPED UNDER A LOW
LEVEL INVERSION. CEILINGS HAVE SLOWLY BEEN DEVELOPING TOWARDS THE
WEST...AND HAVE MADE IT TO KFRG AND KBDR. CONFIDENCE LOW ON JUST
HOW FAR WEST THE MVFR CIGS WILL MAKE IT. WILL TEMPO THE CIGS IN A
KJFK AND KLGA FOR A FEW HOURS LATE THIS MORNING AND EARLY
AFTERNOON FOR THE MVFR CIGS. THE STRATO CU IS EXPECTED TO MIX OUT
EARLY THIS AFTERNOON. THESE MVFR CIGS MAY BECOME DIFFICULT TO
TRACK ON SATELLITE AS HIGHER CLOUDS WILL MOVE OVER THE LOWER
DECK.
WINDS WILL BE FROM THE NORTH TO NORTHEAST AND GENERALLY 10 KT OR
LESS. SOME GUSTS WILL BE POSSIBLE ESPECIALLY ACROSS EASTERN
TERMINALS.
...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: AMENDMENTS POSSIBLE FOR A PERIOD OF MVFR
CIGS LATE THIS MORNING EARLY AFTERNOON. IF CIGS DEVELOP...EXPECT
HEIGHTS BETWEEN 2-3KFT.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR A PERIOD OF MVFR
CIGS LATE THIS MORNING EARLY AFTERNOON. IF CIGS DEVELOP...EXPECT
HEIGHTS BETWEEN 2-3KFT.
KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: OCCASIONAL GUSTS INTO THE UPPER TEENS POSSIBLE
TODAY.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR MARGINAL VFR CEILINGS.
OCCASIONAL GUSTS INTO THE UPPER TEENS POSSIBLE.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY-SUNDAY...VFR.
.MONDAY...MOST LIKELY VFR...SMALL CHANCE OF MVFR.
&&
.MARINE...
MARGINAL SCA CONDITIONS CONTINUE ON THE OCEAN WATERS INTO
FRI...PRIMARILY FOR HAZARDOUS SEAS AROUND 5 FT. A PERSISTENT N/NE
FLOW AND A SE SWELL FROM OFFSHORE LOW PRESSURE ARE THE REASONS FOR
THE HIGH SEAS.
A GRADUALLY STRENGTHENING NE FLOW THROUGH THE WEEKEND INTO EARLY
NEXT WEEK WILL RESULT IN BUILDING SEAS ON THE OCEAN WATERS...WHICH
ARE EXPECTED TO REMAIN ABOVE SCA CRITERIA INTO EARLY NEXT WEEK. AS A
COASTAL LOW PRESSURE FORMS OFF THE SOUTHEAST COAST...THE GRADIENT
STRENGTHENS BETWEEN IT AND HIGH PRESSURE TO THE NORTH. WINDS
INCREASE TO ABOVE SCA CRITERIA BUT NOT QUITE GALE STRENGTH. WAVES
ALSO INCREASE AHEAD OF THE COASTAL SYSTEM AND WILL LIKELY STAY ABOVE
SCA CRITERIA THROUGH THE PERIOD. IF THE STORM TRACKS CLOSER TO THE
COAST THEN CURRENTLY FORECAST...WAVES COULD BE A FEW FEET HIGHER AND
WINDS COULD POTENTIALLY REACH GALE FORCE.
&&
.HYDROLOGY...
DRY WEATHER IS EXPECTED THROUGH EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES WITH SLIGHTLY ANOMALOUS HIGH WATER LEVELS
AND A LIGHT TO MODERATE NORTHEASTERLY FLOW RESULTED IN ANOTHER
ROUND OF MINOR COASTAL FLOODING THIS MORNING WITH LEVELS A FEW
INCHES HIGHER THAN THOSE OBSERVED WEDNESDAY MORNING.
A PROLONGED NE FLOW THROUGH THE WEEKEND INTO EARLY NEXT MAY LEAD
TO ADDITIONAL EPISODES OF MAINLY MINOR COASTAL FLOODING IN
HISTORICALLY VULNERABLE LOCATIONS. THE THREAT OF A STRONG COASTAL
STORM EARLY NEXT WEEK SEEMS MORE UNLIKELY BASED ON LATEST GUIDANCE.
&&
.EQUIPMENT...
THE NATIONAL WEATHER SERVICE DOPPLER WEATHER RADAR AT UPTON NEW YORK
/KOKX/ IS UNAVAILABLE. THE RADAR MAY BE OUT OF SERVICE FOR UP TO 2
WEEKS. ADDITIONAL UPDATES WILL BE MADE AVAILABLE AS MORE INFORMATION
BECOMES AVAILABLE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...LN/DW
NEAR TERM...JST
SHORT TERM...DW
LONG TERM...LN
AVIATION...BC/MET
MARINE...LN/DW
HYDROLOGY...DW
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
140 PM EST THU NOV 15 2012
.SYNOPSIS (REST OF TODAY AND TONIGHT)...
18Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE NORTHERN STREAM FLOW
CARVING OUT A BROAD TROUGH ACROSS THE CENTRAL/EASTERN PORTION OF THE
CONUS. SHORTWAVE TROUGH EMBEDDED WITHIN THE LARGE SCALE FLOW PASSED
TO OUR NORTH THIS MORNING AND IS NOW TAKING ON A NEGATIVE TILT AS
THE FEATURE PIVOTS UP THE EASTERN SEABOARD. 12Z KTBW SOUNDING SHOWED
A MOIST BOUNDARY LAYER UNDER INCREASINGLY DRY MID-LEVELS IN
ASSOCIATION WITH THE DEEP LAYER SUBSIDENCE IN THE WAKE OF THE
PASSING SHORTWAVE. THIS SUBSIDENCE OVER-TOP THE MOIST BOUNDARY LAYER
PROVIDED A GOOD SETUP FOR THE DEVELOPMENT OF THE WIDESPREAD LOW
STRATUS/FOG SEEN ACROSS THE REGION THIS MORNING. THE WEAKER
MID-NOVEMBER SUN ANGLE SLOWED ANY RAPID DISSIPATION OF THIS LAYER.
IT IS ONLY IN THE PAST HOUR OR SO THAT ANY VISIBLE THINNING OF THE
STRATUS CAN BE SEEN IN SATELLITE IMAGERY. EXPECT THESE CLOUDS TO
CONTINUE TO THIN OVER THE NEXT COUPLE OF HOURS WITH PARTLY CLOUDY
SKIES BEING THE GENERAL RULE BY LATE AFTERNOON.
AT THE SURFACE...A WEAK BOUNDARY IS NEARLY STATIONARY OVER THE
SOUTHERN PORTION OF THE PENINSULA. GRADIENT BETWEEN THIS BOUNDARY
AND 1030MB HIGH PRESSURE WELL TO OUR NORTHWEST IS FORCING A STEADY
NORTH TO NORTHEAST LOW LEVEL FLOW ACROSS THE AREA. LOWERED PROJECTED
HIGH TEMPS A COUPLE OF DEGREES OVER CENTRAL/NORTHERN ZONES THIS
AFTERNOON AS THE STUBBORN CLOUDS HAVE LESSENED THE OVERALL
INSOLATION THESE AREAS WILL SEE FOR THE DAY.
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
TONIGHT...A GENERAL ZONAL FLOW WILL BE DOMINANT IN THE MID/UPPER
LEVELS OVER THE FLORIDA PENINSULA AS LARGE SCALE TROUGHING DIGS
SOUTH INTO THE WESTERN/CENTRAL GULF OF MEXICO. ANY SYNOPTIC
LIFT/SUPPORT ASSOCIATED WITH THIS FEATURE SHOULD NOT ARRIVE FOR OUR
AREA UNTIL DURING THE DAY ON FRIDAY...AND EVEN THEN BE WEAK.
THEREFORE STILL ANTICIPATE A GENERALLY DRY OVERNIGHT PERIOD.
RESIDUAL BOUNDARY LAYER MOISTURE SHOULD AGAIN ALLOW FOR THE
DEVELOPMENT OF LOW STRATUS AFTER MIDNIGHT...HOWEVER THE
COVERAGE/EXTENT SHOULD NOT BE AS GREAT AS WHAT WAS OBSERVED THIS
MORNING. WILL FOLLOW CLOSELY WITH THE SREF CEILING PROBABILITIES
WHICH SHOW THE HIGHEST CHANCES/COVERAGE FROM THE PUNTA GORDA AREA
NORTHWARD. LOW TEMPS WILL BE SEASONABLE WITH GENERALLY MID/UPPER 50S
AWAY FROM THE COAST. DEPENDING ON THE EXTENT OF THE CLOUD
COVER...TEMPS NORTH OF BROOKSVILLE MAY BRIEFLY REACH THE UPPER
40S/LOWER 50S. IF STRATUS DEVELOPS EARLY/THICK ENOUGH...THEN LOW
TEMPERATURES WILL BE WARMER.
FRIDAY/FRIDAY NIGHT...AN AMPLIFICATION TO THE PATTERN WILL EVOLVE
OVER THE SOUTHEASTERN CONUS AS LONGWAVE TROUGHING MIGRATES
EASTWARD AND ATTEMPTS TO CLOSE OFF OVER AL/GA. DESPITE SOME WEAK
SYNOPTIC SUPPORT FOR LIFT ASSOCIATED WITH THE APPROACHING HEIGHT
FALLS...OVERALL COLUMN MOISTURE WILL NOT BE THAT IMPRESSIVE.
FORECAST WILL SHOW SLIGHT CHANCES FOR SHOWERS DEVELOPING SOUTH OF
TAMPA BAY DURING THE DAY...AND THEN EXPANDING OVER THE REST OF THE
REGION FRIDAY NIGHT. SHOWERS WILL BE ISOLATED IN NATURE AND NOT
ANTICIPATING MUCH IMPACT IN TERMS OF DURATION OR AMOUNT FOR ANY
PLANNED OUTDOOR ACTIVITIES. SIMILAR TO THIS MORNING...AREAS OF LOWER
STRATUS WILL LIKELY BE RATHER STUBBORN TO BURN OFF AND WILL KEEP
SKIES MOSTLY CLOUDY IN THE GRIDS THROUGH THE MORNING. HIGH
TEMPERATURES LOOK TO RANGE FROM AROUND 70 UP NEAR CHIEFLAND...TO
AROUND 80 DOWN TOWARD FT. MYERS.
SATURDAY/SATURDAY NIGHT...UPPER TROUGH AXIS MOVES OVER THE REGION.
SOME INDICATION THAT THIS ENERGY MAY ATTEMPT TO CLOSE OFF AN AREA OF
WEAK LOW PRESSURE OFF THE GA/NE FL COAST. IF THIS DOES OCCUR...THEN
AN ENHANCEMENT TO THE ONSHORE FLOW MAY LEAD TO A BETTER CHANCE OF
SHOWERS TO THE NORTH OF I-4 ASSOCIATED WITH SPEED CONVERGENCE FOCUS
ORIGINATING ALONG THE NE FL COAST. ELSEWHERE...THE OVERALL WEAK
SYNOPTIC FORCING AND COOLER TEMPERATURES ALOFT SHOULD BE ENOUGH TO
LEAVE SLIGHT CHANCE POPS IN THE GRIDS. ONCE AGAIN THE IMPACTS OF ANY
SHOWERS ARE EXPECTED TO BE MINOR WITH THE MAJORITY OF THE PERIOD
BEING RAIN-FREE.
&&
.LONG TERM (SUNDAY - WEDNESDAY)...
SOUTHERN STREAM SHORTWAVE WILL PUSH ACROSS THE SOUTHEAST U.S.
SUNDAY AND SUNDAY NIGHT...WITH UPPER LEVEL RIDGING BEHIND THE
TROUGH OVER THE GULF OF MEXICO AND FLORIDA MONDAY AND MONDAY
NIGHT. DIGGING TROUGH ALONG THE EASTERN SEABOARD TUESDAY AND
WEDNESDAY WILL GENERATE A SURFACE LOW OFF THE SOUTHEAST COAST
WEDNESDAY.
STRONG SURFACE HIGH PRESSURE OVER THE NORTHEAST U.S. WILL EXTEND
TO THE GULF COAST THROUGH TUESDAY WITH NORTHEAST BOUNDARY LAYER
FLOW ACROSS THE FORECAST AREA. GRADIENT WILL REMAIN RATHER TIGHT
WHICH SHOULD PRECLUDE LATE NIGHT FOG DEVELOPMENT...HOWEVER
CONDITIONS WILL BE FAVORABLE FOR LATE NIGHT/EARLY MORNING LOW
CLOUDS ACROSS MUCH OF THE REGION. SURFACE LOW OFF THE SOUTHEAST
U.S. COAST WEDNESDAY WILL INCREASE THE CHANCE OF SHOWERS OVER THE
REGION. TEMPERATURES WILL RUN NEAR TO SLIGHTLY ABOVE CLIMATIC
NORMALS THROUGH THE PERIOD.
&&
.AVIATION...
LINGERING MVFR/IFR CEILINGS AT KTPA...KPIE...KSRQ...AND KLAL WILL
GIVE WAY TO VFR AFTER 15/20Z AS THE LOW STRATUS CLOUD DECK ERODES.
ADDITIONAL MVFR CEILINGS WILL REDEVELOP AT ALL TAF SITES AFTER 16/06Z
TONIGHT WITH LOCAL IFR/LIFR CIGS POSSIBLE BETWEEN 16/08 16/12Z. VFR
SHOULD RETURN TO ALL TERMINALS AFTER 16/16Z ON FRIDAY. NORTHWEST TO
NORTH WINDS IN THE 6 TO 8 KNOT RANGE THIS AFTERNOON WILL BECOME
NORTHEAST IN THE 4 TO 6 KNOT RANGE AFTER 16/02Z TONIGHT...INCREASING
TO 6 TO 9 KNOTS AFTER 16/15Z ON FRIDAY.
&&
.MARINE...
WINDS WILL REMAIN OUT OF THE NORTHEAST THE NEXT COUPLE OF DAYS
BETWEEN HIGH PRESSURE TO OUR NORTH AND A DEVELOPING SURFACE TROUGH
TO OUR EAST. WINDS ARE EXPECTED TO APPROACH CAUTIONARY LEVELS AT
TIMES THE NEXT COUPLE OF NIGHT...ESPECIALLY FROM TAMPA BAY
NORTHWARD.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE ANTICIPATED THROUGH AT
LEAST THE FIRST HALF OF THE UPCOMING WEEKEND AS RELATIVE HUMIDITY
VALUES WILL GENERALLY REMAIN ABOVE CRITICAL LEVELS. LOWER STRATUS
CLOUDS ARE ONCE AGAIN EXPECTED ACROSS MUCH OF THE AREA FRIDAY
MORNING AND THIS LAYER WILL KEEP DISPERSION INDICES VERY LOW UNTIL
THE CLOUDS BURN OFF DURING THE LATE MORNING/EARLY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 58 75 58 76 / 10 10 20 20
FMY 61 80 61 79 / 10 20 30 20
GIF 57 77 57 78 / 10 10 20 20
SRQ 59 77 60 77 / 10 10 20 20
BKV 50 74 52 74 / 10 10 20 20
SPG 62 74 61 75 / 10 10 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...MCMICHAEL
LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1058 AM EST THU NOV 15 2012
.DISCUSSION...
LATEST RAP ANALYSIS SHOWS A WEAK H100-H85 TROF CENTERED OFF THE
GA/SC COAST TRAILING BACK ACRS THE N GULF COAST...RESULTING IN A
W/NW LOW/MID LVL FLOW ACRS CENTRAL FL. MOISTURE POOLING WITHIN THE
TROF HAS ALLOWED A DENSE LYR OF STRATUS TO PERSIST ACRS THE CENTRAL
PENINSULA.
MORNING RAOBS SHOWED PWAT VALUES ACRS THE STATE BTWN 0.8"-1.1"...BUT
WITH WIDE VARIANCE IN DISTRIBUTION THRU THE COLUMN THAT WELL DEPICT
THE LATEST SAT IMAGERY. KJAX/KTAE MORNING RAOBS SHOW A STOUT
INVERSION IN THE H100-H95 LYR...BOTH SATURATED THRU THE H80 LYR.
INVERSION DISAPPEARS ON THE KTBW-KXMR SOUNDINGS THOUGH HIGH MOISTURE
LVLS ARE APPARENT THRU THE H100-H70 LYR. KMFL SHOWED LITTLE IN THE
WAY OF LOW LVL MOISTURE...SHOULD SEE DRIER AIR MIX DOWN OVER S FL
THAT WILL ERODE THE STRATUS FROM SOUTH TO NORTH THRU THE AFTN. MID
MORNING TEMPS REFLECT THE EXTENT OF THE CLOUD COVER...L/M70S ALONG
THE TREASURE COAST WHERE CLOUDS HAVE BROKEN UP...L/M60S WHERE THE
CLOUDS REMAIN.
WITH DENSE LOW LVL CLOUDS HOLDING FIRM OVER MUCH OF THE CWA...HAD TO
REWORK POPS TO REFLECT HIGHER CHANCES WHERE THE CLOUDS HAVE BROKEN
UP AND LOW LVL HEATING WILL MOST LIKELY OCCUR. W/NW FLOW THRU THE
LOW/MID LVLS WILL LIMIT THE POTENTIAL FOR TSRA...WILL GO WITH SHRAS
INSTEAD. DROPPED MAX TEMPS A FEW DEGS TO REFLECT CLOUD AS WELL.
&&
.AVIATION...
THRU 15/18Z...IFR CIGS/MVFR VSBYS IN LOW STRATUS/MIST/FOG N OF
KVRB/KOBE...PREVAILING VFR S OF KVRB WITH TEMPO IFR CIGS. BTWN
15/18Z-15/20Z...P6SM ALL SITES...AREAS MVFR CIGS BTWN FL020-030 N OF
KTIX-KISM. BTWN 15/20Z-16/04Z...VFR ALL SITES...PREVAILING CIGS BTWN
FL035-050. AFT 16/04Z...IFR CIGS/MVFR VSBYS DVLPG ALL SITES.
&&
.MARINE...
NNW WINDS TO 15 TO 20 KNOTS ACROSS THE NRN WATERS AND SEAS TO 7 FT
OFFSHORE WILL NECESSITATE A SMALL CRAFT ADVISORY FOR THE VOLUSIA AND
BREVARD COUNTY COASTAL WATERS. STRONGEST WINDS/HIGHEST SEAS ARE
NORTH OF CAPE CANAVERAL ACROSS THE NRN BREVARD/VOLUSIA WATERS BUT
HAVE DECIDED TO RAISE ADVISORY FOR CENTRAL AND NRN MARINE AREAS
BASED ON RECENT 41009 WIND/SEA TRENDS THE LAST SEVERAL HOURS. WILL
CONTINUE ADVISORY INTO THIS EVENING BUT WILL LIKELY NEED TO BE
EXTENDED FOR PORTIONS OF THE NORTHERN WATERS INTO TONIGHT AND FRIDAY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
MARINE/IMPACT WX......VOLKMER
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
800 AM EST THU NOV 15 2012
.UPDATE (REST OF TODAY AND TONIGHT)...
13Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A NORTHERN STREAM FLOW
CARVING OUT A BROAD TROUGH ACROSS THE CENTRAL/EASTERN PORTION OF THE
CONUS. SHORTWAVE TROUGH EMBEDDED WITHIN THE LARGE SCALE FLOW HAS
BEEN PASSING TO OUR NORTH EARLY THIS MORNING AND HAS NOW PASSED OUR
LONGITUDE AS IT TAKES ON A NEGATIVE TILT AND BEGINS TO PIVOT UP THE
EASTERN SEABOARD. 12Z KTBW SOUNDING SHOWS A MOIST BOUNDARY LAYER
UNDER INCREASINGLY DRY MID-LEVELS IN ASSOCIATION WITH THE DEEP LAYER
SUBSIDENCE IN THE WAKE OF THE PASSING SHORTWAVE. THIS SUBSIDENCE
OVER-TOP THE MOIST BOUNDARY LAYER HAS PROVIDED A GOOD SETUP FOR THE
DEVELOPMENT OF THE WIDESPREAD LOW STRATUS/FOG SEEN ACROSS THE REGION
THIS MORNING. THE WEAKER MID-NOVEMBER SUN ANGLE WILL NOT AID IN ANY
RAPID DISSIPATION OF THIS LAYER...AND WOULD EXPECT MOSTLY CLOUDY
SKIES TO PERSIST IN SPOTS LIKELY INTO THE LATER MORNING HOURS BEFORE
ANY SIGNIFICANT BURN OFF COMMENCES. LATEST NARRE (NORTH AMERICAN
RAPID REFRESH ENSEMBLE) CEILING PROBABILITIES ARE IN LINE WITH THIS
THINKING AND 12Z TAF PACKAGE HAS BEEN PREPARED ACCORDINGLY.
ONCE THE LOW STRATUS BURNS OFF...WILL BE LOOKING FOR A FAIR AND
GENERALLY DRY DAY UNDER PARTLY CLOUDY SKIES. TEMPERATURES WILL BE A
BIT TRICKY DEPENDING ON JUST WHEN WE SEE THE SUN BREAK THROUGH AND
THE RESULTING POTENTIAL LOSS IN TOTAL INSOLATION THROUGH THE DAY.
WITH A LATE MORNING/MIDDAY BURN OFF EXPECTED...SHOULD STILL BE ABLE
TO MIX OUT TO AFTERNOON HIGHS IN THE LOW 80S SOUTH OF I-4 AND
MID/UPPER 70S FURTHER NORTH. WILL CONTINUE TO MONITOR THE PROGRESS
OF THE STRATUS ON THE GOES-E CLOUD THICKNESS HEIGHT ANALYSIS AND
MAKE ANY ADJUSTMENT TO THE TEMPS/SKY COVER GRIDS AS NECESSARY.
FOR TONIGHT...A GENERAL ZONAL FLOW WILL BE DOMINANT IN THE MID/UPPER
LEVELS OVER THE FLORIDA PENINSULA AS LARGE SCALE TROUGHING DIGS
SOUTH INTO THE WESTERN/CENTRAL GULF OF MEXICO. ANY SYNOPTIC
LIFT/SUPPORT ASSOCIATED WITH THIS FEATURE SHOULD NOT ARRIVE FOR OUR
AREA UNTIL DURING THE DAY ON FRIDAY...AND EVEN THEN BE WEAK.
THEREFORE STILL ANTICIPATE A DRY OVERNIGHT PERIOD. RESIDUAL BOUNDARY
LAYER MOISTURE MAY AGAIN RESULT IN AREAS OF LOW STRATUS AFTER
MIDNIGHT...HOWEVER THE COVERAGE/EXTENT SHOULD NOT BE AS GREAT AS
WHAT IS BEING OBSERVED THIS MORNING. LOW TEMPS WILL BE SEASONABLE
WITH GENERALLY MID/UPPER 50S AWAY FROM THE COAST. NORTH OF
BROOKSVILLE THE TEMPS MAY BRIEFLY REACH THE LOWER 50S...ESPECIALLY
IF THE STRATUS COVERAGE IS MINIMAL.
&&
.AVIATION...
PREVAILING IFR/LIFR CEILINGS AND VISIBILITIES FROM LOW CLOUDS AND
FOG EARLY THIS MORNING WILL LIFT AFTER 15/16Z WITH VFR CONDITIONS
DEVELOPING AT ALL TERMINALS. THERE WILL BE A SLIGHT CHANCE OF A
SHOWER MAINLY IN THE VICINITY OF LAL...PGD...RSW AND FMY DURING THE
AFTERNOON. NORTHEAST WINDS IN THE 5 TO 8 KNOT RANGE THIS MORNING
WILL BECOME NORTH TO NORTHWEST AT 8 TO 10 KNOTS AFTER 15/18Z.
&&
.MARINE...
SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE SOUTH SOUTHWEST FROM
NEW ENGLAND INTO THE GULF OF MEXICO WITH NORTHERLY FLOW TODAY
BECOMING NORTHEASTERLY AND INCREASING OVER THE WEEKEND INTO EARLY
NEXT WEEK. WINDS COULD REACH EXERCISE CAUTION...POSSIBLY ADVISORY
CRITERIA OVER THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 61 78 61 / 10 10 20 20
FMY 82 62 81 62 / 10 10 20 20
GIF 79 58 77 59 / 20 10 20 20
SRQ 79 60 79 61 / 10 10 20 20
BKV 77 54 77 55 / 10 10 20 20
SPG 78 63 78 63 / 10 10 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...MCMICHAEL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1136 PM CST WED NOV 14 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT TERM FORECAST - TONIGHT AND THURSDAY...
21Z RAP SURFACE ANALYSIS INDICATES A WEAK AREA OF BROAD LOW PRESSURE
OVER THE HIGH PLAINS WITH ANOTHER BROAD AREA OF HIGH PRESSURE OVER
THE SE CONUS. BETWEEN THESE TWO FEATURES A WEAK SURFACE PRESSURE
GRADIENT HAS CAUSED SOUTHERLY WINDS AROUND 5 TO 10 MPH TO PERSIST
THROUGHOUT THE DAY. EXPECT THESE SOUTHERLY WINDS TO PERSIST
OVERNIGHT AROUND 5 MPH...WHICH MAY HELP TO KEEP TEMPS SLIGHTLY
WARMER THAN TUESDAY NIGHT AS LOWS ARE EXPECTED TO STAY IN THE LOWER
TO MID 30S. THURSDAY WILL LIKELY BE A REPEAT OF WEDNESDAY WITH SUNNY
SKIES...HOWEVER WINDS MAY BE SLIGHTLY MORE OUT OF THE WEST THAN
WEDNESDAY AND THIS MAY ALLOW FOR TEMPS TO RISE SLIGHTLY HIGHER THAN
WEDNESDAY...WITH HIGHS EXPECTED TO BE IN THE LOWER 60S.
JL
LONG TERM - THURSDAY NIGHT THROUGH WEDNESDAY...
THE LONG TERM PERIOD WILL BE ON THE QUIET SIDE WITH A RATHER DRY
AIRMASS REMAINING ENTRENCHED ACROSS THE PLAINS. THE FLOW PATTERN
ALOFT WILL SEE A FEW DISTURBANCES MOVE THROUGH THE REGION. THE
FIRST MOVES THROUGH ON THURSDAY NIGHT BUT IS A FAST MOVING SYSTEM
THROUGH A MOISTURE STARVED REGION...WHICH WILL RESULT IN A DRY
FRONTAL PASSAGE AND A SLIGHTLY COOLER AIRMASS FOR FRIDAY AND
SATURDAY. THE UPPER FLOW WILL BECOME MORE SOUTHWESTERLY FOR THE
WEEKEND WITH WARM ADVECTION ALOFT AND A WEAK DISTURBANCE SCHEDULED
TO AFFECT THE AREA BY SUNDAY EVENING. TEMPERATURES WILL BE ABOVE
NORMAL INTO SUNDAY NIGHT...AND CURRENT INDICATIONS SUGGEST THAT
SUFFICIENT MOISTENING WILL OCCUR IN ADVANCE OF THIS DISTURBANCE TO
PROVIDE A CHANCE FOR SCATTERED SHOWERS ON SUNDAY NIGHT AND EARLY
MONDAY IN A ZONE OF DEEP ASCENT IMMEDIATELY IN ADVANCE OF THE
SHORT WAVE. A SLIGHTLY DEEPER TROUGH WILL QUICKLY FOLLOW AND MERGE
WITH THE INITIAL SHORT WAVE TROUGH BY MONDAY NIGHT. WHILE THIS
WILL BE A DEEPER SYSTEM...ANY PRECIPITATION WILL LIKELY HOLD OFF
UNTIL THE TWO WAVES MERGE AND STRENGTHEN...EAST OF THE FORECAST
AREA. SO HAVE A DRY FORECAST BEYOND MONDAY WITH CONTINUED ABOVE
NORMAL TEMPERATURES AS UPPER RIDGING AND WARM ADVECTION BUILD INTO
THE REGION THROUGH MID WEEK.
BARJENBRUCH
&&
.AVIATION...
VFR TO CONTINUE THROUGH THE PERIOD. WINDS UNDER 10 KTS EXPECTED
THROUGH THE PERIOD. WINDS WILL BECOME NORTH BETWEEN 19Z-23Z.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1258 PM EST THU NOV 15 2012
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS AND
OFF THE COAST TODAY INTO EARLY FRIDAY MORNING. A LARGE AREA OF
HIGH PRESSURE WILL BUILD ACROSS THE GREAT LAKES AND INTO NEW
ENGLAND FRIDAY AFTERNOON THROUGH SATURDAY. LOW PRESSURE WILL
DEVELOP OFF THE SOUTHEAST COAST SATURDAY NIGHT THROUGH
SUNDAY...THEN SLOWLY TRACK EAST NORTHEAST OUT TO SEA MONDAY INTO
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WDSPRD CLDNS OVR THE RGN RIGHT NOW...AND LIKELY TO CONT THROUGH
THE REST OF THE DAY. WK/DE-AMPLIFYING S/W TRACKING THROUGH THE
CAROLINAS W/ WK SFC LO PRES OFFSHR CONTG TO SPREAD MSTR NWD INTO
THE RGN. LGT RA HAVING DIFFICULTY SPREADING N THROUGH CNTRL/ERN
NC. LATEST RUC FOLLOWS CURRENT FCST IN KEEPING RA MNLY S OF THE
VA/NC BRDR LATER TDA INTO TNGT AS SYS EXITS OFF THE CST. MINOR
ADJSTMNTS MADE TO TEMPS...W/ HI TEMPS FM THE U40S-ARND 50F W OF
I95...TO RANGING THROUGH THE 50S TO THE E.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
BEST LO LVL MOISTURE/LIFT FCST RMN INVOF SE VA AND NE NC WHERE
CURRENT POPS OF 30-40% STILL LUK GOOD FOR TNGT INTO EARLY FRI
MORNG. SLGT CHC POPS OF 20% WILL COME INTO A LINE EXTENDING FM
AVC-JGG-OXB. LOWS TNGT RANGING FM THE LWR 30S TO THE LWR 40S.
A LARGE AREA OF HI PRES WILL BLD ACRS THE GRT LKS AND INTO NEW
ENGLAND FRI AFTN THRU SAT. WHILE MOISTURE RIBBON WILL LINGER
INVOF THE CSTL CAROLINAS FM FRI AFTN THRU SAT...THE HI PRES SHOULD
KEEP OUR WX DRY DURING THE PERIOD...WITH MORE CLOUDINESS POSSIBLE
OVER NE NC. OTHRWISE...EXPECT A PRTLY OR MSTLY SNY SKY ACRS MUCH
OF THE REGION BOTH DAYS...WITH HI TEMPS IN THE LWR TO MID 50S.
LOWS FRI NGT RANGING THRU THE 30S TO ARND 40.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS STILL HAVING DIFFICULTY RESOLVING PROGRESS OF UPPER LEVEL
TROUGH THROUGH THE MEDIUM RANGE PERIOD. GOOD AGREEMENT WITH UPPER
LEVEL FEATURES INITIALLY AS MAJORITY OF ENSEMBLES AND OPERATIONAL
GFS/ECMWF SHOW SPLIT FLOW DEVELOPING, WITH A PIECE OF UPPER
SHORTWAVE ENERGY SPLITTING OFF FROM NORTHERN STREAM AND DROPPING
ACROSS THE SOUTHEAST US SAT-SUN, EVENTUALLY DEVELOPING INTO A
AMPLIFYING/DIGGING CLOSED UPPER LOW OVER THE SOUTHEAST BY LATE IN
THE WEEKEND. DIFFERENCES SPRING FROM THERE, WITH BULK OF UNCERTAINTY
IN THIS FORECAST PERTAINING TO EXTENT OF DIGGING AND THE POTENTIAL
FOR SFC CYCLOGENESIS (DEVELOPING SFC LOW) ALONG THE SE COAST BY LATE
IN THE WEEKEND.
OPERATIONAL ECMWF (12Z) REMAINS A BIT FARTHER WEST WITH THE
DEVELOPING UPPER TROUGH, WHICH WOULD SERVE TO BRING POTENTIAL
DEVELOPING LOW PRESSURE CENTER CLOSER TO THE EAST COAST THAN THE
FARTHER OFFSHORE GFS SOLUTION. STILL, APPEARS AS IF MODELS DO AGREE
THAT BULK OF HEAVIER PCPN WILL REMAIN CONFINED OFFSHORE. FORECAST
CONFIDENCE IS HIGH ENOUGH ATTM TO CONTINUE RAMPING RAIN CHCS SUNDAY,
WITH HIGHEST (~50%) POP ACROSS COASTAL ZONES SUNDAY AND SUNDAY
NIGHT, WITH LOWER (SLIGHT TO LOW CHC AT BEST) RAIN CHCS SUN/SUN
NIGHT WEST OF I-95.
LATER IN THE PERIOD, ECMWF ALSO SHOWING SIGNS OF DEVELOPING A RATHER
SHARP REX BLOCKING TYPE SIGNATURE IN THE NORTHERN ATLANTIC EARLY
NEXT WEEK. WHILE THE UPPER LOW ITSELF WOULD SLIDE OFF THE EAST COAST
MON-TUE, SLIDING BEST RAIN CHCS OFFSHORE WITH IT, THE PROGRESS OF
NEXT MID-UPPER TROUGH ARRIVING FROM THE MIDWEST WOULD LIKELY LEAD TO
A PROLONGED PERIOD OF COOL NE FLOW. ACCORDINGLY, WENT WITH MOSTLY
CLDY CONDITIONS PERSISTING FOR MUCH OF EARLY NEXT WEEK IN DIGITAL
DB, WITH LOW RAIN CHCS ACROSS COASTAL ZONES (DRY INLAND). CLOUDS
WOULD KEEP TEMPS AVERAGING BELOW NORMAL THROUGH THE PERIOD. HIGHS
GENERALLY IN THE 50S, LOWS IN THE 30S INLAND TO L40S AT THE COAST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
BKN/OVC CONDITIONS IN PLACE ACRS THE REGION. WINDS TODAY WILL BE
N/NE AVERAGING 10-15 KT AT KORF/KECG AND 10 KT OR LESS ELSEWHERE.
EXPECT -RA AT KECG AROUND 23 Z BUT SHOULD NOT HAVE MUCH AFFECT ON
VSBYS. WEAK SYSTEM SLIDES OFF THE COASTAL CAROLINAS TONIGHT AND
MAINLY DRY CONDITIONS WILL PREVAIL ALTHOUGH LOW CLOUDS WILL PERSIST
ESPECIALLY IN SE VA/NE NC. VFR CONDITIONS WILL PREVAIL BEGINNING
FRI MORNING.
EXPECT ANOTHER PERIOD OF LOWER CIGS AND A CHANCE FOR RAIN LATE
SAT-SUN. N/NE FLOW PREVAILS THROUGHOUT...AND WILL TEND TO INCREASE
AGAIN SUN/MON CLOSER TO THE COAST.
&&
.MARINE...
LATEST OBS REFLECT N/NE FLOW 15 TO 20 KT ACROSS THE MAJORITY OF THE
WATERS...WITH SOMEWHAT LOWER WIND SPEEDS IN THE UPPER BAY AND RIVERS
OUTSIDE OF THE LOWER JAMES. SEAS OVER ATLANTIC COAST ZONES STILL AVG
5-7 FT...WAVES OVER THE CENTRAL/SOUTHERN BAY 3-4 FT. LATER
TODAY/TONIGHT...MODELS ALL GENLY AGREE THAT THE SURGE AND PRESSURE
GRADIENT SLACKENS OFF A LITTLE MORE SO SCA`S OVER BAY/SND SLATED TO
COME DOWN THIS EVENING...WHILE SCA`S REMAIN IN EFFECT FOR THE COAST
AS SEAS ARE EXPECTED TO REMAIN 4-5 FT OR HIGHER. A BIT OF A LULL IN
THE GRADIENT FRI-SAT...BUT STILL WITH CONDITIONS THAT ARE AT LEAST
CLOSE TO SCA LEVELS IN THE BAY/RIVERS/SOUND SO IT WILL BE LESS THAN
IDEAL BOATING THROUGHOUT THE REGION (SCA`S WILL LIKELY NEED TO BE
EXTENDED FOR THE COASTAL WATERS FOR 4-5 FT SEAS).
LATER SAT INTO SUN SUN/MON...STRONG HIGH PRESSURE BUILDS INTO NEW
ENGLAND...AS ANOTHER AREA OF SFC LOW PRESSURE IS EXPECTED TO DEVELOP
OFF THE COASTAL CAROLINAS BY LATE IN THE WEEKEND. RE-TIGHTENING OF
PRESSURE GRADIENT BETWEEN THESE FEATURES IS LIKELY TO RESULT IN
ANOTHER PERIOD OF STRONG SCA CONDITIONS (POSSIBLY RAMPING UP TO LOW
END GALES BY LATE SUNDAY ON THE COAST). WHILE THE SYSTEM APPEARS
WEAKER THAN PREVIOUS MODEL RUNS...SCA CONDITIONS ARE STILL VERY
LIKELY TO PERSIST THROUGH THE MUCH OF THE FIRST HALF OF NEXT WEEK.
SEAS AVG 6-9 FT ON THE COAST...WITH WAVES IN THE BAY 3-5 FT SUN-MON.
&&
.TIDES/COASTAL FLOODING...
CONTINUED N/NE WINDS 15-20 KT TODAY ACRS MUCH OF THE MARINE
AREA...AND HAVE HOISTED A COASTAL FLOOD ADSY FOR PORTIONS OF THE
OCEAN SIDE OF THE ERN SHORE FOR VERY MARGINAL MINOR FLOODING W/ THE
UPCOMING LATE MORNING TIDE CYCLE (SEE CFWAKQ FOR DETAILS). THE
ANOMALIES ARE ONLY ABOUT 1 FOOT BUT THE ASTRONOMICAL TIDES ARE
RATHER HIGH DUE TO THE NEW MOON CYCLE. FARTHER SOUTH ANOMALIES ARE
RUNNING 0.5 TO 1 FOOT ABOVE NORMAL BUT THE WATER LEVELS LOOK TO STAY
ABOUT 0.5 FT BELOW THRESHOLDS (WILL MENTION PORTIONS OF HAMPTON
ROADS IN THE HWO FOR NUISANCE FLOODING POSSIBLE RIGHT AT THE TIME OF
HIGH TIDE THIS MORNING).
THE NEXT HIGH TIDE CYCLE THAT MAY BE CLOSE TO MINOR FLOODING
THRESHOLDS WILL BE LATE THIS EVENING/TONIGHT. WINDS GENLY LOOK TO
SLACKEN OFF THOUGH SO AGAIN IT WILL BE VERY MARGINAL SO WILL LET
NEXT SHIFT EVALUATE NEED FOR THIS LATER TODAY.
FOR THE WEEKEND/EARLY NEXT WEEK...PATTERN OF A VERY STRONG/1040 MB
SFC HIGH BUILDING INTO NEW ENGLAND AND A TROUGH OFF THE SE COAST
WOULD MAKE WINDS TURN MORE TO THE NE (RATHER THAN N)...LEADING TO
THE POTENTIAL FOR MORE TIDAL FLOODING. LATEST MODEL TRENDS ARE A
LITTLE SLOWER...WEAKER...AND MORE OFFSHORE WITH THE TRACK OF THE
EVENTUAL COASTAL SYSTEM...WHICH WOULD SUGGEST LESS OF A FLOODING
IMPACT THAN WHAT WAS PREVIOUSLY ANTICIPATED. THERE IS STILL TOO MUCH
UNCERTAINTY AND THE FACT THAT THE GFS-BASED MDL GUIDANCE IS NOT
SHOWING MUCH OF AN ANOMALY ON SUNDAY COULD JUST BE DUE TO THE
GUIDANCE BEING UNDERDONE THIS FAR OUT IN THE PERIOD. IN ANY
EVENT...WILL NEED TO CONTINUE TO MONITOR AND WOULD EXPECT AT LEAST
SOME MINOR TIDAL FLOODING ACRS PORTIONS OF THE AREA SUN/MON.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ632>634.
SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ654-656-658.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...ALB/TMG
NEAR TERM...ALB/TMG
SHORT TERM...ALB/TMG
LONG TERM...MAM
AVIATION...LKB/DAP
MARINE...LKB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1014 AM EST THU NOV 15 2012
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS AND
OFF THE COAST TODAY INTO EARLY FRIDAY MORNING. A LARGE AREA OF
HIGH PRESSURE WILL BUILD ACROSS THE GREAT LAKES AND INTO NEW
ENGLAND FRIDAY AFTERNOON THROUGH SATURDAY. LOW PRESSURE WILL
DEVELOP OFF THE SOUTHEAST COAST SATURDAY NIGHT THROUGH
SUNDAY...THEN SLOWLY TRACK EAST NORTHEAST OUT TO SEA MONDAY INTO
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WDSPRD CLDNS OVR THE RGN RIGHT NOW...AND LIKELY TO CONT THROUGH
THE REST OF THE DAY. WK/DE-AMPLIFYING S/W TRACKING THROUGH THE
CAROLINAS W/ WK SFC LO PRES OFFSHR CONTG TO SPREAD MSTR NWD INTO
THE RGN. LGT RA HAVING DIFFICULTY SPREADING N THROUGH CNTRL/ERN
NC. LATEST RUC FOLLOWS CURRENT FCST IN KEEPING RA MNLY S OF THE
VA/NC BRDR LATER TDA INTO TNGT AS SYS EXITS OFF THE CST. MINOR
ADJSTMNTS MADE TO TEMPS...W/ HI TEMPS FM THE U40S-ARND 50F W OF
I95...TO RANGING THROUGH THE 50S TO THE E.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
BEST LO LVL MOISTURE/LIFT FCST RMN INVOF SE VA AND NE NC WHERE
CURRENT POPS OF 30-40% STILL LUK GOOD FOR TNGT INTO EARLY FRI
MORNG. SLGT CHC POPS OF 20% WILL COME INTO A LINE EXTENDING FM
AVC-JGG-OXB. LOWS TNGT RANGING FM THE LWR 30S TO THE LWR 40S.
A LARGE AREA OF HI PRES WILL BLD ACRS THE GRT LKS AND INTO NEW
ENGLAND FRI AFTN THRU SAT. WHILE MOISTURE RIBBON WILL LINGER
INVOF THE CSTL CAROLINAS FM FRI AFTN THRU SAT...THE HI PRES SHOULD
KEEP OUR WX DRY DURING THE PERIOD...WITH MORE CLOUDINESS POSSIBLE
OVER NE NC. OTHRWISE...EXPECT A PRTLY OR MSTLY SNY SKY ACRS MUCH
OF THE REGION BOTH DAYS...WITH HI TEMPS IN THE LWR TO MID 50S.
LOWS FRI NGT RANGING THRU THE 30S TO ARND 40.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS STILL HAVING DIFFICULTY RESOLVING PROGRESS OF UPPER LEVEL
TROUGH THROUGH THE MEDIUM RANGE PERIOD. GOOD AGREEMENT WITH UPPER
LEVEL FEATURES INITIALLY AS MAJORITY OF ENSEMBLES AND OPERATIONAL
GFS/ECMWF SHOW SPLIT FLOW DEVELOPING, WITH A PIECE OF UPPER
SHORTWAVE ENERGY SPLITTING OFF FROM NORTHERN STREAM AND DROPPING
ACROSS THE SOUTHEAST US SAT-SUN, EVENTUALLY DEVELOPING INTO A
AMPLIFYING/DIGGING CLOSED UPPER LOW OVER THE SOUTHEAST BY LATE IN
THE WEEKEND. DIFFERENCES SPRING FROM THERE, WITH BULK OF UNCERTAINTY
IN THIS FORECAST PERTAINING TO EXTENT OF DIGGING AND THE POTENTIAL
FOR SFC CYCLOGENESIS (DEVELOPING SFC LOW) ALONG THE SE COAST BY LATE
IN THE WEEKEND.
OPERATIONAL ECMWF (12Z) REMAINS A BIT FARTHER WEST WITH THE
DEVELOPING UPPER TROUGH, WHICH WOULD SERVE TO BRING POTENTIAL
DEVELOPING LOW PRESSURE CENTER CLOSER TO THE EAST COAST THAN THE
FARTHER OFFSHORE GFS SOLUTION. STILL, APPEARS AS IF MODELS DO AGREE
THAT BULK OF HEAVIER PCPN WILL REMAIN CONFINED OFFSHORE. FORECAST
CONFIDENCE IS HIGH ENOUGH ATTM TO CONTINUE RAMPING RAIN CHCS SUNDAY,
WITH HIGHEST (~50%) POP ACROSS COASTAL ZONES SUNDAY AND SUNDAY
NIGHT, WITH LOWER (SLIGHT TO LOW CHC AT BEST) RAIN CHCS SUN/SUN
NIGHT WEST OF I-95.
LATER IN THE PERIOD, ECMWF ALSO SHOWING SIGNS OF DEVELOPING A RATHER
SHARP REX BLOCKING TYPE SIGNATURE IN THE NORTHERN ATLANTIC EARLY
NEXT WEEK. WHILE THE UPPER LOW ITSELF WOULD SLIDE OFF THE EAST COAST
MON-TUE, SLIDING BEST RAIN CHCS OFFSHORE WITH IT, THE PROGRESS OF
NEXT MID-UPPER TROUGH ARRIVING FROM THE MIDWEST WOULD LIKELY LEAD TO
A PROLONGED PERIOD OF COOL NE FLOW. ACCORDINGLY, WENT WITH MOSTLY
CLDY CONDITIONS PERSISTING FOR MUCH OF EARLY NEXT WEEK IN DIGITAL
DB, WITH LOW RAIN CHCS ACROSS COASTAL ZONES (DRY INLAND). CLOUDS
WOULD KEEP TEMPS AVERAGING BELOW NORMAL THROUGH THE PERIOD. HIGHS
GENERALLY IN THE 50S, LOWS IN THE 30S INLAND TO L40S AT THE COAST.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
BKN/OVC CONDITIONS IN PLACE ACRS THE REGION...WITH 2-3 K FT CIGS
EXPECTED TO SLOWLY LOWER TO 1-2 K FT BETWEEN 09-15Z. SOUNDINGS AND
CURRENT OBS DO NOT SHOW MUCH CHANCE FOR CIGS TO DROP BELOW 1 K FT
(IFR) BUT IT COULD BE CLOSE ALONG THE COAST. WINDS TODAY WILL BE
N/NE AVERAGING 10-15 KT AT KORF/KECG AND 10 KT OR LESS ELSEWHERE.
HAVE ADDED -RA TO KECG FOR MUCH OF THE DAY...CHANCE FOR -RA ELSEWHERE
AS WELL BUT GENLY SHOULD NOT HAVE MUCH AFFECT ON VSBYS.
OUTLOOK...WEAK SYSTEM SLIDES OFF THE COASTAL CAROLINAS TONIGHT AND MAINLY
DRY CONDITIONS WILL PREVAIL ALTHOUGH LOW CLOUDS PERSIST ESPECIALLY
SE VA/NE NC. CLEARING/VFR FRI...WITH ANOTHER PERIOD OF LOWER CIGS
AND A CHANCE FOR RAIN LATE SAT-SUN. N/NE FLOW PREVAILS THROUGHOUT...AND
WILL TEND TO INCREASE AGAIN SUN/MON CLOSER TO THE COAST.
&&
.MARINE...
LATEST OBS REFLECT N/NE FLOW 15 TO 20 KT ACROSS THE MAJORITY OF THE
WATERS...WITH SOMEWHAT LOWER WIND SPEEDS IN THE UPPER BAY AND RIVERS
OUTSIDE OF THE LOWER JAMES. SEAS OVER ATLANTIC COAST ZONES STILL AVG
5-7 FT...WAVES OVER THE CENTRAL/SOUTHERN BAY 3-4 FT. LATER
TODAY/TONIGHT...MODELS ALL GENLY AGREE THAT THE SURGE AND PRESSURE
GRADIENT SLACKENS OFF A LITTLE MORE SO SCA`S OVER BAY/SND SLATED TO
COME DOWN THIS EVENING...WHILE SCA`S REMAIN IN EFFECT FOR THE COAST
AS SEAS ARE EXPECTED TO REMAIN 4-5 FT OR HIGHER. A BIT OF A LULL IN
THE GRADIENT FRI-SAT...BUT STILL WITH CONDITIONS THAT ARE AT LEAST
CLOSE TO SCA LEVELS IN THE BAY/RIVERS/SOUND SO IT WILL BE LESS THAN
IDEAL BOATING THROUGHOUT THE REGION (SCA`S WILL LIKELY NEED TO BE
EXTENDED FOR THE COASTAL WATERS FOR 4-5 FT SEAS).
LATER SAT INTO SUN SUN/MON...STRONG HIGH PRESSURE BUILDS INTO NEW
ENGLAND...AS ANOTHER AREA OF SFC LOW PRESSURE IS EXPECTED TO DEVELOP
OFF THE COASTAL CAROLINAS BY LATE IN THE WEEKEND. RE-TIGHTENING OF
PRESSURE GRADIENT BETWEEN THESE FEATURES IS LIKELY TO RESULT IN
ANOTHER PERIOD OF STRONG SCA CONDITIONS (POSSIBLY RAMPING UP TO LOW
END GALES BY LATE SUNDAY ON THE COAST). WHILE THE SYSTEM APPEARS
WEAKER THAN PREVIOUS MODEL RUNS...SCA CONDITIONS ARE STILL VERY
LIKELY TO PERSIST THROUGH THE MUCH OF THE FIRST HALF OF NEXT WEEK.
SEAS AVG 6-9 FT ON THE COAST...WITH WAVES IN THE BAY 3-5 FT SUN-MON.
&&
.TIDES/COASTAL FLOODING...
CONTINUED N/NE WINDS 15-20 KT TODAY ACRS MUCH OF THE MARINE
AREA...AND HAVE HOISTED A COASTAL FLOOD ADSY FOR PORTIONS OF THE
OCEAN SIDE OF THE ERN SHORE FOR VERY MARGINAL MINOR FLOODING W/ THE
UPCOMING LATE MORNING TIDE CYCLE (SEE CFWAKQ FOR DETAILS). THE
ANOMALIES ARE ONLY ABOUT 1 FOOT BUT THE ASTRONOMICAL TIDES ARE
RATHER HIGH DUE TO THE NEW MOON CYCLE. FARTHER SOUTH ANOMALIES ARE
RUNNING 0.5 TO 1 FOOT ABOVE NORMAL BUT THE WATER LEVELS LOOK TO STAY
ABOUT 0.5 FT BELOW THRESHOLDS (WILL MENTION PORTIONS OF HAMPTON
ROADS IN THE HWO FOR NUISANCE FLOODING POSSIBLE RIGHT AT THE TIME OF
HIGH TIDE THIS MORNING).
THE NEXT HIGH TIDE CYCLE THAT MAY BE CLOSE TO MINOR FLOODING
THRESHOLDS WILL BE LATE THIS EVENING/TONIGHT. WINDS GENLY LOOK TO
SLACKEN OFF THOUGH SO AGAIN IT WILL BE VERY MARGINAL SO WILL LET
NEXT SHIFT EVALUATE NEED FOR THIS LATER TODAY.
FOR THE WEEKEND/EARLY NEXT WEEK...PATTERN OF A VERY STRONG/1040 MB
SFC HIGH BUILDING INTO NEW ENGLAND AND A TROUGH OFF THE SE COAST
WOULD MAKE WINDS TURN MORE TO THE NE (RATHER THAN N)...LEADING TO
THE POTENTIAL FOR MORE TIDAL FLOODING. LATEST MODEL TRENDS ARE A
LITTLE SLOWER...WEAKER...AND MORE OFFSHORE WITH THE TRACK OF THE
EVENTUAL COASTAL SYSTEM...WHICH WOULD SUGGEST LESS OF A FLOODING
IMPACT THAN WHAT WAS PREVIOUSLY ANTICIPATED. THERE IS STILL TOO MUCH
UNCERTAINTY AND THE FACT THAT THE GFS-BASED MDL GUIDANCE IS NOT
SHOWING MUCH OF AN ANOMALY ON SUNDAY COULD JUST BE DUE TO THE
GUIDANCE BEING UNDERDONE THIS FAR OUT IN THE PERIOD. IN ANY
EVENT...WILL NEED TO CONTINUE TO MONITOR AND WOULD EXPECT AT LEAST
SOME MINOR TIDAL FLOODING ACRS PORTIONS OF THE AREA SUN/MON.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...COASTAL FLOOD ADVISORY UNTIL NOON EST TODAY FOR MDZ024-025.
NC...NONE.
VA...COASTAL FLOOD ADVISORY UNTIL NOON EST TODAY FOR VAZ099.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
ANZ632>634.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ631-638.
SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ654-656-658.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ650-652.
&&
$$
SYNOPSIS...ALB/TMG
NEAR TERM...ALB/TMG
SHORT TERM...ALB/TMG
LONG TERM...MAM
AVIATION...LKB
MARINE...LKB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
328 AM EST THU NOV 15 2012
.SYNOPSIS...
SURFACE HIGH PRESSURE CENTERED OVER EASTERN CANADA WILL RIDGE
SOUTHWARD TOWARD THE MID-ATLANTIC STATES TODAY. A SECONDARY AREA OF
HIGH PRESSURE WILL THEN BUILD IN FROM THE GREAT LAKES FRIDAY. LOW
PRESSURE DEVELOPING OFF THE SOUTHEAST COAST THIS WEEKEND IS EXPECTED
TO REMAIN WELL SOUTH AND EAST OF THE REGION AS HIGH PRESSURE REMAINS
IN CONTROL THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
08Z SFC ANALYSIS SHOWS A 1037-MB HIGH CENTERED OVER ERN QUEBEC. THIS
HIGH WILL CONTINUE TO RIDGE SWD INTO THE MID-ATLANTIC REGION TDA. AN
UPPER SHORTWAVE TROUGH WILL CROSS THE SRN APPALACHIANS THIS MRNG AND
MOVE ACROSS THE CAROLINAS THIS AFTN/TNGT. HI-LVL CS STREAMING AHEAD
OF THE TROUGH WILL PROVIDE MSTLY CLOUDY TO CLOUDY SKIES FOR MOST OF
TDA. FCST MODEL SOUNDINGS SHOW A STRONG SUBSIDENCE INVERSION
PERSISTING AROUND 4KFT TDA. BENEATH THIS INVERSION...MOISTURE
BETWEEN 3-4 KFT AGL WILL REMAIN TRAPPED WHILE LGT ELY FLOW WILL
CONTINUE TO ADVECT STRATUS DECK INLAND THIS MRNG. THE STRATUS
DECK...WHICH HAS SPREAD WEST OF I-95 AS OF 08Z...WILL ENHANCE CLOUD
COVER TDA FROM THE BLUE RIDGE-EWD. CLEARING SHOULD OCCUR IN THE MTS
LATER THIS MRNG AND AFTN AS THE UPPER TROUGH AND BACK EDGE OF CS
PROGRESS EWD.
DESPITE WAA IN THE LLVLS...CLOUD COVER WILL KEEP TEMPS THIS AFTN NOT
MUCH WARMER THAN YDA...MID 40S TO LOWER 50S. MIN TEMPS TNGT RANGE
FROM THE MID 20S ALONG THE ALLEGHENY FRONT TO UPPER 30S IN THE
CITIES AND ALONG WRN SHORE OF THE BAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
A S/WV AXIS WL CROSS THE CWFA FRI. FUNCTIONALLY...ITS MERELY A
DIVIDER BTWN TWO AREAS OF HIPRES DOMINATING THE GRTLKS AND NEW
ENGLAND. IT APPEARS TO BE RELATIVELY MSTR-STARVED...AND SHUD SUPPORT
VARYING AMTS OF MID-HIGH LVL CLDS. THE LATTER RDG WL BE OVER THE
NERN CONUS BY SAT.
H8 TEMPS CHG LTL THRU THE PD...BUT H10-8 TKNS VALUES SUGGEST
MODERATION OF THE LLVLS. THAT/LL PERMIT MAXT TO COME CLSR TO
CLIMO...AS REFLECTED IN LTST MOS. MIN-T A LTL TRICKIER...AS DEWPTS
LOW. CLDCVR WL DICTATE HOW LOW MIN-T CAN GET.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
GDNC CONTG TO PLACE INCRSG EMPHASIS ON HIPRES RDG IN THE NERN CONUS
INFLUENCING WX IN THE MID ATLC. THEREFORE...ANY CYCLOGENESIS WL BE
WEAKER AND FURTHER TO THE S. LCLLY...THAT MEANS IMPACTS WL BE
LESS...AND WL CONT TREND FM YDA OF SCALING POPS BACK SAT NGT-MON.
WUDNT BE SURPRISED TO SEE ENTIRE WKND DRY...BUT ATTM WL MAINTAIN AT
LEAST A 20-30 PCT CHC RA E OF I-95 SUN NGT-MON. THAT TOO CAN BE
RMVD IF CURRENT TRENDS PERSIST. ONE THING THAT CANT BE DISCOUNTED
JUST YET THO IS THE EXTENT OF LLVL CLDS/DZ WORKING INLAND
DEPENDING ON HOW MUCH OF A NELY FLOW CAN BE MAINTAINED. WL HV
MOCLDY SKIES SHEN VLY EWD SUN NGT-MON AS A CONSEQUENCE. TEMPS
REMAIN AOB NRML GIVEN N/NELY FLOW.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
BKN-OVC STRATUS BETWEEN 3 AND 4 KFT HAS MOVED WWD ERY THIS MRNG INTO
DCA/BWI/MTN/IAD. LATEST HRRR AND LAMP GUIDANCE HAS STRATUS REMAINING
EAST OF MRB/CHO. LOWER CLOUDS SHOULD ERODE FROM NW TO SE DURING THE
MID TO LATE AFTN. LGT NLY WINDS AROUND 5 KT THIS MRNG WILL VEER
SLIGHTLY TO NELY THIS AFTN AND TNGT.
VFR CONDS XPCTD THRU SAT UNDER HIPRES.
HIPRES OVER NEW ENGLND SUN-MON COMBINED W/ WK DVLPG LOPRES OFF THE
SE CONUS WL LEAD TO NELY FLOW. ITS STILL TBD HOW MUCH MSTR CAN WORK
INLAND. AT LEAST OCNL FLGT RESTRICTIONS SEEM PLAUSIBLE...W/ IFR CIGS
PSBL.
&&
.MARINE...
LGT N-NE FLOW GENERALLY AOB 10 KT TDA AND TNGT...ALTHOUGH A FEW
HIGHER GUSTS TO 15 KT LIKELY IN THE MAIN STEM OF THE CHSPK BAY.
NLY FLOW GNLY AOB 10 KT THRU SAT...ALTHO MID BAY MAY BE CLSR TO
10-15 KT. ANY GUSTS SHUD REMAIN BLO SCA CRITERIA.
SUN-MON A BIT MORE QSTNBL...DEPENDING ON STRENGTH OF P-GRAD BTWN
HIPRES OVR NEW ENGLAND AND DVLPG LOPRES OFF THE SERN CONUS. IF SCA
WERE TO BE REQD...MID BAY/TANGIER SOUND/MOUTH OF THE PTMC APPEAR
MORE FVRBL. WL CARRY THAT POTL IN THE HWO.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JRK
NEAR TERM...JRK
SHORT TERM...HTS
LONG TERM...HTS
AVIATION...JRK/HTS
MARINE...JRK/HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1238 PM EST THU NOV 15 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM EST THU NOV 15 2012
00Z RAOBS AND RUC ANALYSIS SHOW PRETTY QUIET WESTERLY SPLIT FLOW
ALOFT WITH MINIMAL H5 HEIGHT FALLS OR RISES NOTED UPSTREAM. STRONGEST
SHORTWAVE WITHIN THE FLOW IS IN THE NORTHERN STREAM PUSHING ACROSS
MANITOBA INTO NORTHERN ONTARIO. COLD FRONT ASSOCIATED WITH THIS WAVE
IS STRONG. TEMPS HAVE FALLEN INTO THE TEENS IN CENTRAL MANITOBA AND
INTO SINGLE NUMBERS BACK OVR SASKATCHEWAN. BATCH OF HEAVIER SNOW IS
ACCOMPANYING THE FRONT IN NORTHERN MANITOBA...BUT NOT MUCH IS
OCCURRING FARTHER SOUTH ALONG THE COLD FRONT. ONLY OTHER SHORTWAVE
RELATIVELY CLOSE BY IS MOVING ACROSS CENTRAL MINNESOTA. DESPITE DRY
LOW-LEVELS SEEN OVER AREA LAST DAY...THIS WAVE IS STRONG ENOUGH TO
PRODUCE SOME LGT SHRA OVER ECNTRL MN WITHIN LAST 2 HOURS. OVER UPR
MICHIGAN IT IS ANOTHER NIGHT WITH A LOT OF MID CLOUDS BUT NO PRECIP.
TEMPS IN MANY AREAS EARLY THIS MORNING ARE CLOSE TO WHAT IS A TYPICAL
NORMAL HIGH TEMP FOR 15 NOVEMBER AKA THE FIRE ARM RIFLE DEER HUNTING
OPENER FOR MICHIGAN.
AS NORTHERN STREAM TROUGH PRESSES EAST TODAY...ASSOCIATED SFC LOW
MOVES ACROSS HUDSON BAY AND SFC COLD FRONT TAKES AIM ON UPR MICHIGAN
LATE TODAY. UNTIL ARRIVAL OF THE FRONT...DEPENDING ON EXTENT OF
CLOUD COVER...APPEARS WE COULD HAVE MAKING OF FAIRLY WARM DAY. MID
CLOUDS ALREADY TRYING TO SCT OUT OVER WESTERN UPR MICHIGAN AND AT
LEAST PARTIAL SUNSHINE IS EXPECTED FOR MUCH OF WESTERN AND CENTRAL
CWA THIS MORNING. WILL HAVE TO WATCH WI BORDER THOUGH AS SHORTWAVE
OVR MN MAY PUSH CLOSE BY ENOUGH TO AT LEAST INCREASE CLOUDS AGAIN
THIS MORNING AND EVEN PRODUCE A FEW SPRINKLES TOWARD KIMT. MIXING TO
925MB SUPPORTS TEMPS WELL INTO THE 40S BY MID AFTN WITH DOWNSLOPE SW
WINDS PUSHING READINGS INTO LOWER 50S NEAR LK SUPERIOR NCNTRL IF
CLOUDS ARE DELAYED. BY MID AFTN...EXPECT MID CLOUDS /H8-H7 RH/ TO
BUILD BACK OVER CWA FROM THE SOUTHWEST WHILE BATCH OF CLOUDS JUST
AHEAD OF COLD FRONT SLIDE INTO CWA FROM ONTARIO. FORECAST SOUNDINGS
INDICATE THERE WILL BE ENOUGH DEEPER MOISTURE AND UVM WITHIN ICE
NUCLEATION ZONE TO GENERATE A FEW SHOWERS AFT 21Z. SREF/HIGHER RES
MODELS FROM NCEP AND NAM/LOCAL WRF-ARW AGREE PRECIP MAINLY AFFECTS
ALGER/SCHOOLCRAFT/LUCE. DAYTIME HEATING INCREASES 1000-H85 LAPSE
RATES OVR MUCH OF EAST HALF AHEAD OF FRONT...SO ALSO ADDED ISOLD
MENTION AS FAR WEST AS MARQUETTE/DELTA COUNTIES. PTYPE ONLY RAIN AS
WBZERO HEIGHTS ARE WELL ABOVE 1KFT AGL. ONLY POSSIBILITY OF SEEING
SOME SNOW MIXING IN WOULD BE OVER HIGHER TERRAIN OF MQT COUNTY IN
EVENING...BUT MOST OF SYNOPTIC PRECIP SHOULD DONE BY THIS TIME.
ONCE FRONT MOVES THROUGH...A PORTION OF COLD AIR SEEN UPSTREAM WILL
MAKE RUN ACROSS LK SUPERIOR AND INTO UPR MICHIGAN. IT IS A SHALLOW
COLDER AIRMASS OVR MANITOBA AS 925MB TEMPS ARE COLDER THAN THOSE AT
850MB. SETUP TONIGHT OVER UPR MICHIGAN NO DIFFERENT. NORTHWEST WINDS
IN WAKE OF FRONT EVENTUALLY TURN MORE NORTHERLY AS SFC HIGH
CURRENTLY OVR NORTHERN ROCKIES AND NORTHERN PLAINS EXTENDS A RIDGE
INTO NORTHERN ONTARIO AND NORTHERN LK SUPERIOR. NORTH LOW-LEVEL
WINDS ALONG WITH INCREASING SUB H85 MOISTURE SEEN ON UPSTREAM
SOUNDINGS AT YQD /CNTRL MANITOBA/ AND YSM /NORTHWEST TERRITORIES/
ALONG WITH LOWERING SUBSIDENCE INVERSION /TEMPS AT INVERSION TOP
AROUND -7C/ CONTINUE TO SUPPORT GOING FCST OF FZDZ OR FLURRIES OVR
HIGHLANDS OF NCNTRL UPR MICHIGAN. DESPITE INCREASING CLOUDS...PREFER
TO GO COLDER WITH MINS TONIGHT WITH SHALLOW INVERSION/STABLE TEMP
PROFILE. MOST AREAS WILL FALL INTO THE 20S WEST/CNTRL WITH NEAR 30
FOR EASTERN CWA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 423 AM EST THU NOV 15 2012
A FAIRLY QUIET PERIOD OF WX IS IN STORE THRU THIS WEEKEND AS A ZONAL
FLOW OF RELATIVELY MILD PACIFIC AIR DOMINATES.
FRI...SFC HI PRES RDG AXIS IS FCST TO MOVE FM MN INTO NW ONTARIO TO
AN A LINE FM UPR MI INTO ONTARIO BY 00Z SAT AS H5 RDG BUILDS OVER
THE UPR LKS. PREFER THE CLOUDIER NAM DEPICTION OF EVENTS GIVEN FCST
SHARP INVNR ARND 3K FT ENHANCED BY SHALLOW COLD INFUSION AND
TRAPPING LLVL AIRMASS MOISTENED IN PASSAGE OVER LK SUP. ONCE THE HI
PRES RDG PASSES TO THE E...EXPECT STUBBORN LO CLDS TO BREAK UP AS
THE FLOW TURNS OFFSHORE. BUT OVER THE NCNTRL...THIS WSHFT IS NOT
FCST TO OCCUR UNTIL LATE IN THE DAY. SO SUSPECT THE DAY WL BE MOCLDY
IN THIS AREA...WITH SOME MRNG -FZDZ OVER THE HIER TERRAIN OF THE
NCENTRAL WHERE LLVL N VEERING E WIND UPSLOPES AND LLVL MSTR REMAINS
TRAPPED BLO SHARP INVRN BTWN H9-925 MAINTAINED BY DEEP LYR QVECTOR
DVGC/SUBSIDENCE. EVEN OVER THE W... FCST LIGHT WINDS SUG THE LO CLD
MAY BE QUITE TENACIOUS GIVEN SHARP LO INVRN BASE THAT TRAPS THE LLVL
MSTR. AREAS FM IWD-ONTONAGON- KEWEENAW PROBABLY HAVE THE BEST SHOT
AT SEEING SOME CLRG WITH A MORE PRONOUCNED DOWNSLOPE WIND COMPONENT.
DVLPG E FLOW OFF LK MI WL ALSO BRING ABOUT MORE SC OVER THE
SCENTRAL...BUT THERE MAY SOME PARTIAL CLRG OVER THE E WITH
DOWNSLOPING OFF ONTARIO AND LOSS OF LK MOISTENING COMPONENT. WITH
PLENTY OF CLD COVER LINGERING ALL DAY OVER THE NCENTRAL...MAX TEMPS
MAY STRUGGLE TO RISE ABV 32 ACRS THE HIER TERRAIN IN THAT AREA.
FRI NGT...AS HI SHIFTS TO THE E...THE LLVL WINDS WL VEER MORE TO THE
S. IN CONCERT WITH INVRN SINKING CLOSER TO THE SFC AS SHOWN BY NAM
FCST SDNGS...THIS FLOW SHOULD ALLOW THE SKY TO BECOME CLR TO PCLDY.
DESPITE THE CLRG...INCRSG S WINDS WL TEND TO LIMIT THE DIURNAL TEMP
FALL AT LEAST OVER THE W. THE LOWEST MIN TEMPS SHOULD BE OVER THE
INTERIOR CENTRAL AND E WHERE THE H925 WINDS WL BE AOB 10 KTS MOST IF
NOT ALL OF THE NGT. WITH PWAT AOB 0.25 INCH...TENDED AOB THE LO END
OF GUIDANCE FOR MIN TEMPS IN THIS AREA EVEN THOUGH SOME HI CLDS
MIGHT ARRIVE OVERNGT IN MORE WSW FLOW ALF.
SAT THRU SUN...THE UPR GRT LKS WL BE DOMINATED BY STEADY SW FLOW
BTWN HI PRES DRIFTING INTO NEW ENGLAND AND LO PRES TROF IN THE
PLAINS DOWNWIND OF DEEPENING WRN TROF. DESPITE THE STRENGTHENING SSW
LLVL FLOW...MODELS ADVERTISE LTL MOISTENING IN THE LO-MID LVLS. BUT
WSW FLOW ALF WL BRING SCT-BKN HI CLDS. TEMPS WL AVG ABOVE NORMAL
THRU THE WEEKEND WITH H85 TEMPS FCST FM 1 TO 4C. THE HIEST TEMPS
SHOULD BE OVER THE DOWNSLOPE AREAS NEAR LK SUP ON SUN DESPITE SOME
THICKER HI CLD.
EXTENDED...GUIDANCE INDICATES THE PERSISTENT SW FLOW FM THE SRN
PLAINS INTO THE UPR GRT LKS ON WRN FLANK OF HI PRES OVER THE NE
CONUS MAY TAP MORE MOIST AIRMASS BY MON. AS DIFFICULT TO TIME
SHRTWVS EJECT FM THE WRN TROF EWD TOWARD THE UPR GRT LKS EARLY NEXT
WEEK...MODEL CONSENSUS INDICATES SCHC POPS ARE WARRANTED FOR MON
THRU WED. GUIDANCE SEEMS TO HAVE TRENDED TOWARD KEEPING THE TROF OUT
W LONGER...SO LATER UPDATES MAY TREND TOWARD DRIER WX. TEMPS WL
REMAIN WELL ABV THE SEASONAL NORM WITH PACIFIC AIR DOMINATING UNDER
WSW FLOW ALF.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM EST THU NOV 15 2012
A COLD FRONT WILL MOVE THROUGH NEAR OR SHORTLY AFTER 18Z TAF
ISSUANCE AT IWD AND CMX...AND LATER IN THE DAY AT SAW. COLDER AIR
BEHIND THE FRONT MAY BRING LOWER LAKE EFFECT CIGS AT ALL SITES
TONIGHT...BUT MOISTURE SEEMS TO LIMITED FOR ANY PRECIP.
HOWEVER...SAW WILL SEE THE BEST CHANCES FOR PRECIP LATE TONIGHT INTO
EARLY FRI AS WIND DIRECTIONS WILL BE MORE FAVORABLE FOR PRECIP
THERE...BUT VIS IS NOT EXPECTED TO DROP ALL THAT MUCH IN ANY LIGHT
SNOW OR FREEZING DRIZZLE THAT DEVELOPS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 AM EST THU NOV 15 2012
EXPECT S-SW WINDS UP TO 25-30 KTS TODAY IN ADVANCE OF APPROACHING
COLD FNT TO SHIFT TO THE N-NW THIS AFTERNOON/EVENING ONCE THE FRONT
PASSES W-E ACROSS THE LAKE. NOT OUT OF THE QUESTION THERE COULD BE A
FEW GALE FORCE GUSTS JUST AHEAD OF THE FRONT MAINLY OVER THE
NCENTRAL LAKE WITH TERRAIN BETWEEN ISLE ROYALE AND THE KEWEENAW
ENHANCING EXPECTED WSW WIND. APPROACH OF TRAILING HI PRES WILL THEN
CAUSE QUICKLY DIMINISHING WINDS BY FRI WHICH WILL CONTINUE THRU FRI
NIGHT. OVER THE WEEKEND INTO EARLY NEXT WEEK...LAKE SUP WILL BE
DOMINATED BY S WINDS BETWEEN HI PRES MOVING INTO NEW ENGLAND AND A
LO PRES TROF IN THE PLAINS. THE STRONGEST S WINDS UP TO 25 KTS
DURING THIS PERIOD ARE MOST LIKELY OVER THE E HALF OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...TITUS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
651 AM EST THU NOV 15 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM EST THU NOV 15 2012
00Z RAOBS AND RUC ANALYSIS SHOW PRETTY QUIET WESTERLY SPLIT FLOW
ALOFT WITH MINIMAL H5 HEIGHT FALLS OR RISES NOTED UPSTREAM. STRONGEST
SHORTWAVE WITHIN THE FLOW IS IN THE NORTHERN STREAM PUSHING ACROSS
MANITOBA INTO NORTHERN ONTARIO. COLD FRONT ASSOCIATED WITH THIS WAVE
IS STRONG. TEMPS HAVE FALLEN INTO THE TEENS IN CENTRAL MANITOBA AND
INTO SINGLE NUMBERS BACK OVR SASKATCHEWAN. BATCH OF HEAVIER SNOW IS
ACCOMPANYING THE FRONT IN NORTHERN MANITOBA...BUT NOT MUCH IS
OCCURRING FARTHER SOUTH ALONG THE COLD FRONT. ONLY OTHER SHORTWAVE
RELATIVELY CLOSE BY IS MOVING ACROSS CENTRAL MINNESOTA. DESPITE DRY
LOW-LEVELS SEEN OVER AREA LAST DAY...THIS WAVE IS STRONG ENOUGH TO
PRODUCE SOME LGT SHRA OVER ECNTRL MN WITHIN LAST 2 HOURS. OVER UPR
MICHIGAN IT IS ANOTHER NIGHT WITH A LOT OF MID CLOUDS BUT NO PRECIP.
TEMPS IN MANY AREAS EARLY THIS MORNING ARE CLOSE TO WHAT IS A TYPICAL
NORMAL HIGH TEMP FOR 15 NOVEMBER AKA THE FIRE ARM RIFLE DEER HUNTING
OPENER FOR MICHIGAN.
AS NORTHERN STREAM TROUGH PRESSES EAST TODAY...ASSOCIATED SFC LOW
MOVES ACROSS HUDSON BAY AND SFC COLD FRONT TAKES AIM ON UPR MICHIGAN
LATE TODAY. UNTIL ARRIVAL OF THE FRONT...DEPENDING ON EXTENT OF
CLOUD COVER...APPEARS WE COULD HAVE MAKING OF FAIRLY WARM DAY. MID
CLOUDS ALREADY TRYING TO SCT OUT OVER WESTERN UPR MICHIGAN AND AT
LEAST PARTIAL SUNSHINE IS EXPECTED FOR MUCH OF WESTERN AND CENTRAL
CWA THIS MORNING. WILL HAVE TO WATCH WI BORDER THOUGH AS SHORTWAVE
OVR MN MAY PUSH CLOSE BY ENOUGH TO AT LEAST INCREASE CLOUDS AGAIN
THIS MORNING AND EVEN PRODUCE A FEW SPRINKLES TOWARD KIMT. MIXING TO
925MB SUPPORTS TEMPS WELL INTO THE 40S BY MID AFTN WITH DOWNSLOPE SW
WINDS PUSHING READINGS INTO LOWER 50S NEAR LK SUPERIOR NCNTRL IF
CLOUDS ARE DELAYED. BY MID AFTN...EXPECT MID CLOUDS /H8-H7 RH/ TO
BUILD BACK OVER CWA FROM THE SOUTHWEST WHILE BATCH OF CLOUDS JUST
AHEAD OF COLD FRONT SLIDE INTO CWA FROM ONTARIO. FORECAST SOUNDINGS
INDICATE THERE WILL BE ENOUGH DEEPER MOISTURE AND UVM WITHIN ICE
NUCLEATION ZONE TO GENERATE A FEW SHOWERS AFT 21Z. SREF/HIGHER RES
MODELS FROM NCEP AND NAM/LOCAL WRF-ARW AGREE PRECIP MAINLY AFFECTS
ALGER/SCHOOLCRAFT/LUCE. DAYTIME HEATING INCREASES 1000-H85 LAPSE
RATES OVR MUCH OF EAST HALF AHEAD OF FRONT...SO ALSO ADDED ISOLD
MENTION AS FAR WEST AS MARQUETTE/DELTA COUNTIES. PTYPE ONLY RAIN AS
WBZERO HEIGHTS ARE WELL ABOVE 1KFT AGL. ONLY POSSIBILITY OF SEEING
SOME SNOW MIXING IN WOULD BE OVER HIGHER TERRAIN OF MQT COUNTY IN
EVENING...BUT MOST OF SYNOPTIC PRECIP SHOULD DONE BY THIS TIME.
ONCE FRONT MOVES THROUGH...A PORTION OF COLD AIR SEEN UPSTREAM WILL
MAKE RUN ACROSS LK SUPERIOR AND INTO UPR MICHIGAN. IT IS A SHALLOW
COLDER AIRMASS OVR MANITOBA AS 925MB TEMPS ARE COLDER THAN THOSE AT
850MB. SETUP TONIGHT OVER UPR MICHIGAN NO DIFFERENT. NORTHWEST WINDS
IN WAKE OF FRONT EVENTUALLY TURN MORE NORTHERLY AS SFC HIGH
CURRENTLY OVR NORTHERN ROCKIES AND NORTHERN PLAINS EXTENDS A RIDGE
INTO NORTHERN ONTARIO AND NORTHERN LK SUPERIOR. NORTH LOW-LEVEL
WINDS ALONG WITH INCREASING SUB H85 MOISTURE SEEN ON UPSTREAM
SOUNDINGS AT YQD /CNTRL MANITOBA/ AND YSM /NORTHWEST TERRITORIES/
ALONG WITH LOWERING SUBSIDENCE INVERSION /TEMPS AT INVERSION TOP
AROUND -7C/ CONTINUE TO SUPPORT GOING FCST OF FZDZ OR FLURRIES OVR
HIGHLANDS OF NCNTRL UPR MICHIGAN. DESPITE INCREASING CLOUDS...PREFER
TO GO COLDER WITH MINS TONIGHT WITH SHALLOW INVERSION/STABLE TEMP
PROFILE. MOST AREAS WILL FALL INTO THE 20S WEST/CNTRL WITH NEAR 30
FOR EASTERN CWA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 423 AM EST THU NOV 15 2012
A FAIRLY QUIET PERIOD OF WX IS IN STORE THRU THIS WEEKEND AS A ZONAL
FLOW OF RELATIVELY MILD PACIFIC AIR DOMINATES.
FRI...SFC HI PRES RDG AXIS IS FCST TO MOVE FM MN INTO NW ONTARIO TO
AN A LINE FM UPR MI INTO ONTARIO BY 00Z SAT AS H5 RDG BUILDS OVER
THE UPR LKS. PREFER THE CLOUDIER NAM DEPICTION OF EVENTS GIVEN FCST
SHARP INVNR ARND 3K FT ENHANCED BY SHALLOW COLD INFUSION AND
TRAPPING LLVL AIRMASS MOISTENED IN PASSAGE OVER LK SUP. ONCE THE HI
PRES RDG PASSES TO THE E...EXPECT STUBBORN LO CLDS TO BREAK UP AS
THE FLOW TURNS OFFSHORE. BUT OVER THE NCNTRL...THIS WSHFT IS NOT
FCST TO OCCUR UNTIL LATE IN THE DAY. SO SUSPECT THE DAY WL BE MOCLDY
IN THIS AREA...WITH SOME MRNG -FZDZ OVER THE HIER TERRAIN OF THE
NCENTRAL WHERE LLVL N VEERING E WIND UPSLOPES AND LLVL MSTR REMAINS
TRAPPED BLO SHARP INVRN BTWN H9-925 MAINTAINED BY DEEP LYR QVECTOR
DVGC/SUBSIDENCE. EVEN OVER THE W... FCST LIGHT WINDS SUG THE LO CLD
MAY BE QUITE TENACIOUS GIVEN SHARP LO INVRN BASE THAT TRAPS THE LLVL
MSTR. AREAS FM IWD-ONTONAGON- KEWEENAW PROBABLY HAVE THE BEST SHOT
AT SEEING SOME CLRG WITH A MORE PRONOUCNED DOWNSLOPE WIND COMPONENT.
DVLPG E FLOW OFF LK MI WL ALSO BRING ABOUT MORE SC OVER THE
SCENTRAL...BUT THERE MAY SOME PARTIAL CLRG OVER THE E WITH
DOWNSLOPING OFF ONTARIO AND LOSS OF LK MOISTENING COMPONENT. WITH
PLENTY OF CLD COVER LINGERING ALL DAY OVER THE NCENTRAL...MAX TEMPS
MAY STRUGGLE TO RISE ABV 32 ACRS THE HIER TERRAIN IN THAT AREA.
FRI NGT...AS HI SHIFTS TO THE E...THE LLVL WINDS WL VEER MORE TO THE
S. IN CONCERT WITH INVRN SINKING CLOSER TO THE SFC AS SHOWN BY NAM
FCST SDNGS...THIS FLOW SHOULD ALLOW THE SKY TO BECOME CLR TO PCLDY.
DESPITE THE CLRG...INCRSG S WINDS WL TEND TO LIMIT THE DIURNAL TEMP
FALL AT LEAST OVER THE W. THE LOWEST MIN TEMPS SHOULD BE OVER THE
INTERIOR CENTRAL AND E WHERE THE H925 WINDS WL BE AOB 10 KTS MOST IF
NOT ALL OF THE NGT. WITH PWAT AOB 0.25 INCH...TENDED AOB THE LO END
OF GUIDANCE FOR MIN TEMPS IN THIS AREA EVEN THOUGH SOME HI CLDS
MIGHT ARRIVE OVERNGT IN MORE WSW FLOW ALF.
SAT THRU SUN...THE UPR GRT LKS WL BE DOMINATED BY STEADY SW FLOW
BTWN HI PRES DRIFTING INTO NEW ENGLAND AND LO PRES TROF IN THE
PLAINS DOWNWIND OF DEEPENING WRN TROF. DESPITE THE STRENGTHENING SSW
LLVL FLOW...MODELS ADVERTISE LTL MOISTENING IN THE LO-MID LVLS. BUT
WSW FLOW ALF WL BRING SCT-BKN HI CLDS. TEMPS WL AVG ABOVE NORMAL
THRU THE WEEKEND WITH H85 TEMPS FCST FM 1 TO 4C. THE HIEST TEMPS
SHOULD BE OVER THE DOWNSLOPE AREAS NEAR LK SUP ON SUN DESPITE SOME
THICKER HI CLD.
EXTENDED...GUIDANCE INDICATES THE PERSISTENT SW FLOW FM THE SRN
PLAINS INTO THE UPR GRT LKS ON WRN FLANK OF HI PRES OVER THE NE
CONUS MAY TAP MORE MOIST AIRMASS BY MON. AS DIFFICULT TO TIME
SHRTWVS EJECT FM THE WRN TROF EWD TOWARD THE UPR GRT LKS EARLY NEXT
WEEK...MODEL CONSENSUS INDICATES SCHC POPS ARE WARRANTED FOR MON
THRU WED. GUIDANCE SEEMS TO HAVE TRENDED TOWARD KEEPING THE TROF OUT
W LONGER...SO LATER UPDATES MAY TREND TOWARD DRIER WX. TEMPS WL
REMAIN WELL ABV THE SEASONAL NORM WITH PACIFIC AIR DOMINATING UNDER
WSW FLOW ALF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 649 AM EST THU NOV 15 2012
SCT-BKN MID CLOUDS /VFR CONDITIONS/ EXPECTED THROUGH EARLY AFTN AT
ALL TAF SITES. SW WINDS MAY GUST TO 20 KTS MID MORNING THROUGH EARLY
AFTN. COLD FRONT CURRENTLY OVER SOUTHERN MANITOBA ARRIVES MID-LATE
AFTERNOON AT IWD AND CMX THEN BY EVENING AT SAW. MVFR CIGS LIKELY
THROUGH TONIGHT IN WAKE OF THE FRONT. AT SAW...WINDS BECOMING NORTHERLY
AND ADDITIONAL MOISTURE FROM LK SUPERIOR COULD SUPPORT IFR CIGS AND
FLURRIES/FZDZ LATE TONIGHT. JUST HINTED AT THIS POSSIBILITY IN THE
TAF DUE TO UNCERTAINTY OF EXTENT OF LOW-LEVEL MOISTURE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 AM EST THU NOV 15 2012
EXPECT S-SW WINDS UP TO 25-30 KTS TODAY IN ADVANCE OF APPROACHING
COLD FNT TO SHIFT TO THE N-NW THIS AFTERNOON/EVENING ONCE THE FRONT
PASSES W-E ACROSS THE LAKE. NOT OUT OF THE QUESTION THERE COULD BE A
FEW GALE FORCE GUSTS JUST AHEAD OF THE FRONT MAINLY OVER THE
NCENTRAL LAKE WITH TERRAIN BETWEEN ISLE ROYALE AND THE KEWEENAW
ENHANCING EXPECTED WSW WIND. APPROACH OF TRAILING HI PRES WILL THEN
CAUSE QUICKLY DIMINISHING WINDS BY FRI WHICH WILL CONTINUE THRU FRI
NIGHT. OVER THE WEEKEND INTO EARLY NEXT WEEK...LAKE SUP WILL BE
DOMINATED BY S WINDS BETWEEN HI PRES MOVING INTO NEW ENGLAND AND A
LO PRES TROF IN THE PLAINS. THE STRONGEST S WINDS UP TO 25 KTS
DURING THIS PERIOD ARE MOST LIKELY OVER THE E HALF OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...JLA
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 AM EST THU NOV 15 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 423 AM EST THU NOV 15 2012
00Z RAOBS AND RUC ANALYSIS SHOW PRETTY QUIET WESTERLY SPLIT FLOW
ALOFT WITH MINIMAL H5 HEIGHT FALLS OR RISES NOTED UPSTREAM. STRONGEST
SHORTWAVE WITHIN THE FLOW IS IN THE NORTHERN STREAM PUSHING ACROSS
MANITOBA INTO NORTHERN ONTARIO. COLD FRONT ASSOCIATED WITH THIS WAVE
IS STRONG. TEMPS HAVE FALLEN INTO THE TEENS IN CENTRAL MANITOBA AND
INTO SINGLE NUMBERS BACK OVR SASKATCHEWAN. BATCH OF HEAVIER SNOW IS
ACCOMPANYING THE FRONT IN NORTHERN MANITOBA...BUT NOT MUCH IS
OCCURRING FARTHER SOUTH ALONG THE COLD FRONT. ONLY OTHER SHORTWAVE
RELATIVELY CLOSE BY IS MOVING ACROSS CENTRAL MINNESOTA. DESPITE DRY
LOW-LEVELS SEEN OVER AREA LAST DAY...THIS WAVE IS STRONG ENOUGH TO
PRODUCE SOME LGT SHRA OVER ECNTRL MN WITHIN LAST 2 HOURS. OVER UPR
MICHIGAN IT IS ANOTHER NIGHT WITH A LOT OF MID CLOUDS BUT NO PRECIP.
TEMPS IN MANY AREAS EARLY THIS MORNING ARE CLOSE TO WHAT IS A TYPICAL
NORMAL HIGH TEMP FOR 15 NOVEMBER AKA THE FIRE ARM RIFLE DEER HUNTING
OPENER FOR MICHIGAN.
AS NORTHERN STREAM TROUGH PRESSES EAST TODAY...ASSOCIATED SFC LOW
MOVES ACROSS HUDSON BAY AND SFC COLD FRONT TAKES AIM ON UPR MICHIGAN
LATE TODAY. UNTIL ARRIVAL OF THE FRONT...DEPENDING ON EXTENT OF
CLOUD COVER...APPEARS WE COULD HAVE MAKING OF FAIRLY WARM DAY. MID
CLOUDS ALREADY TRYING TO SCT OUT OVER WESTERN UPR MICHIGAN AND AT
LEAST PARTIAL SUNSHINE IS EXPECTED FOR MUCH OF WESTERN AND CENTRAL
CWA THIS MORNING. WILL HAVE TO WATCH WI BORDER THOUGH AS SHORTWAVE
OVR MN MAY PUSH CLOSE BY ENOUGH TO AT LEAST INCREASE CLOUDS AGAIN
THIS MORNING AND EVEN PRODUCE A FEW SPRINKLES TOWARD KIMT. MIXING TO
925MB SUPPORTS TEMPS WELL INTO THE 40S BY MID AFTN WITH DOWNSLOPE SW
WINDS PUSHING READINGS INTO LOWER 50S NEAR LK SUPERIOR NCNTRL IF
CLOUDS ARE DELAYED. BY MID AFTN...EXPECT MID CLOUDS /H8-H7 RH/ TO
BUILD BACK OVER CWA FROM THE SOUTHWEST WHILE BATCH OF CLOUDS JUST
AHEAD OF COLD FRONT SLIDE INTO CWA FROM ONTARIO. FORECAST SOUNDINGS
INDICATE THERE WILL BE ENOUGH DEEPER MOISTURE AND UVM WITHIN ICE
NUCLEATION ZONE TO GENERATE A FEW SHOWERS AFT 21Z. SREF/HIGHER RES
MODELS FROM NCEP AND NAM/LOCAL WRF-ARW AGREE PRECIP MAINLY AFFECTS
ALGER/SCHOOLCRAFT/LUCE. DAYTIME HEATING INCREASES 1000-H85 LAPSE
RATES OVR MUCH OF EAST HALF AHEAD OF FRONT...SO ALSO ADDED ISOLD
MENTION AS FAR WEST AS MARQUETTE/DELTA COUNTIES. PTYPE ONLY RAIN AS
WBZERO HEIGHTS ARE WELL ABOVE 1KFT AGL. ONLY POSSIBILITY OF SEEING
SOME SNOW MIXING IN WOULD BE OVER HIGHER TERRAIN OF MQT COUNTY IN
EVENING...BUT MOST OF SYNOPTIC PRECIP SHOULD DONE BY THIS TIME.
ONCE FRONT MOVES THROUGH...A PORTION OF COLD AIR SEEN UPSTREAM WILL
MAKE RUN ACROSS LK SUPERIOR AND INTO UPR MICHIGAN. IT IS A SHALLOW
COLDER AIRMASS OVR MANITOBA AS 925MB TEMPS ARE COLDER THAN THOSE AT
850MB. SETUP TONIGHT OVER UPR MICHIGAN NO DIFFERENT. NORTHWEST WINDS
IN WAKE OF FRONT EVENTUALLY TURN MORE NORTHERLY AS SFC HIGH
CURRENTLY OVR NORTHERN ROCKIES AND NORTHERN PLAINS EXTENDS A RIDGE
INTO NORTHERN ONTARIO AND NORTHERN LK SUPERIOR. NORTH LOW-LEVEL
WINDS ALONG WITH INCREASING SUB H85 MOISTURE SEEN ON UPSTREAM
SOUNDINGS AT YQD /CNTRL MANITOBA/ AND YSM /NORTHWEST TERRITORIES/
ALONG WITH LOWERING SUBSIDENCE INVERSION /TEMPS AT INVERSION TOP
AROUND -7C/ CONTINUE TO SUPPORT GOING FCST OF FZDZ OR FLURRIES OVR
HIGHLANDS OF NCNTRL UPR MICHIGAN. DESPITE INCREASING CLOUDS...PREFER
TO GO COLDER WITH MINS TONIGHT WITH SHALLOW INVERSION/STABLE TEMP
PROFILE. MOST AREAS WILL FALL INTO THE 20S WEST/CNTRL WITH NEAR 30
FOR EASTERN CWA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 423 AM EST THU NOV 15 2012
A FAIRLY QUIET PERIOD OF WX IS IN STORE THRU THIS WEEKEND AS A ZONAL
FLOW OF RELATIVELY MILD PACIFIC AIR DOMINATES.
FRI...SFC HI PRES RDG AXIS IS FCST TO MOVE FM MN INTO NW ONTARIO TO
AN A LINE FM UPR MI INTO ONTARIO BY 00Z SAT AS H5 RDG BUILDS OVER
THE UPR LKS. PREFER THE CLOUDIER NAM DEPICTION OF EVENTS GIVEN FCST
SHARP INVNR ARND 3K FT ENHANCED BY SHALLOW COLD INFUSION AND
TRAPPING LLVL AIRMASS MOISTENED IN PASSAGE OVER LK SUP. ONCE THE HI
PRES RDG PASSES TO THE E...EXPECT STUBBORN LO CLDS TO BREAK UP AS
THE FLOW TURNS OFFSHORE. BUT OVER THE NCNTRL...THIS WSHFT IS NOT
FCST TO OCCUR UNTIL LATE IN THE DAY. SO SUSPECT THE DAY WL BE MOCLDY
IN THIS AREA...WITH SOME MRNG -FZDZ OVER THE HIER TERRAIN OF THE
NCENTRAL WHERE LLVL N VEERING E WIND UPSLOPES AND LLVL MSTR REMAINS
TRAPPED BLO SHARP INVRN BTWN H9-925 MAINTAINED BY DEEP LYR QVECTOR
DVGC/SUBSIDENCE. EVEN OVER THE W... FCST LIGHT WINDS SUG THE LO CLD
MAY BE QUITE TENACIOUS GIVEN SHARP LO INVRN BASE THAT TRAPS THE LLVL
MSTR. AREAS FM IWD-ONTONAGON- KEWEENAW PROBABLY HAVE THE BEST SHOT
AT SEEING SOME CLRG WITH A MORE PRONOUCNED DOWNSLOPE WIND COMPONENT.
DVLPG E FLOW OFF LK MI WL ALSO BRING ABOUT MORE SC OVER THE
SCENTRAL...BUT THERE MAY SOME PARTIAL CLRG OVER THE E WITH
DOWNSLOPING OFF ONTARIO AND LOSS OF LK MOISTENING COMPONENT. WITH
PLENTY OF CLD COVER LINGERING ALL DAY OVER THE NCENTRAL...MAX TEMPS
MAY STRUGGLE TO RISE ABV 32 ACRS THE HIER TERRAIN IN THAT AREA.
FRI NGT...AS HI SHIFTS TO THE E...THE LLVL WINDS WL VEER MORE TO THE
S. IN CONCERT WITH INVRN SINKING CLOSER TO THE SFC AS SHOWN BY NAM
FCST SDNGS...THIS FLOW SHOULD ALLOW THE SKY TO BECOME CLR TO PCLDY.
DESPITE THE CLRG...INCRSG S WINDS WL TEND TO LIMIT THE DIURNAL TEMP
FALL AT LEAST OVER THE W. THE LOWEST MIN TEMPS SHOULD BE OVER THE
INTERIOR CENTRAL AND E WHERE THE H925 WINDS WL BE AOB 10 KTS MOST IF
NOT ALL OF THE NGT. WITH PWAT AOB 0.25 INCH...TENDED AOB THE LO END
OF GUIDANCE FOR MIN TEMPS IN THIS AREA EVEN THOUGH SOME HI CLDS
MIGHT ARRIVE OVERNGT IN MORE WSW FLOW ALF.
SAT THRU SUN...THE UPR GRT LKS WL BE DOMINATED BY STEADY SW FLOW
BTWN HI PRES DRIFTING INTO NEW ENGLAND AND LO PRES TROF IN THE
PLAINS DOWNWIND OF DEEPENING WRN TROF. DESPITE THE STRENGTHENING SSW
LLVL FLOW...MODELS ADVERTISE LTL MOISTENING IN THE LO-MID LVLS. BUT
WSW FLOW ALF WL BRING SCT-BKN HI CLDS. TEMPS WL AVG ABOVE NORMAL
THRU THE WEEKEND WITH H85 TEMPS FCST FM 1 TO 4C. THE HIEST TEMPS
SHOULD BE OVER THE DOWNSLOPE AREAS NEAR LK SUP ON SUN DESPITE SOME
THICKER HI CLD.
EXTENDED...GUIDANCE INDICATES THE PERSISTENT SW FLOW FM THE SRN
PLAINS INTO THE UPR GRT LKS ON WRN FLANK OF HI PRES OVER THE NE
CONUS MAY TAP MORE MOIST AIRMASS BY MON. AS DIFFICULT TO TIME
SHRTWVS EJECT FM THE WRN TROF EWD TOWARD THE UPR GRT LKS EARLY NEXT
WEEK...MODEL CONSENSUS INDICATES SCHC POPS ARE WARRANTED FOR MON
THRU WED. GUIDANCE SEEMS TO HAVE TRENDED TOWARD KEEPING THE TROF OUT
W LONGER...SO LATER UPDATES MAY TREND TOWARD DRIER WX. TEMPS WL
REMAIN WELL ABV THE SEASONAL NORM WITH PACIFIC AIR DOMINATING UNDER
WSW FLOW ALF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1233 AM EST THU NOV 15 2012
VFR CONDITIONS WILL PERSIST AT ALL TAF SITES TONIGHT THROUGH THE DAY AS
ONLY MID LEVEL CLOUDS ARE EXPECTED. HOWEVER...AS A COLD FRONT MOVES
THROUGH THE REGION LATE THIS AFTERNOON AND WINDS VEER FROM SSW TO
NNW BY EVENING EXPECT CIGS TO DROP INTO THE MVFR RANGE. THE LOWER
CIGS WILL BE SUPPORTED BY AN INFLUX OF COLDER AIR...LOW LEVEL
MOISTENING ACROSS LAKE SUPERIOR AND UPSLOPE FLOW INTO THE HIGHER
TERRAIN. SOME DZ OR -FZDZ/FLURRIES MAY ALSO BE POSSIBLE MAINLY AT
KSAW BUT PROBABILITY IS LOW AND ANY PCPN IS NOT EXPECTED TO AFFECT
VSBY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 AM EST THU NOV 15 2012
EXPECT S-SW WINDS UP TO 25-30 KTS TODAY IN ADVANCE OF APPROACHING
COLD FNT TO SHIFT TO THE N-NW THIS AFTERNOON/EVENING ONCE THE FRONT
PASSES W-E ACROSS THE LAKE. NOT OUT OF THE QUESTION THERE COULD BE A
FEW GALE FORCE GUSTS JUST AHEAD OF THE FRONT MAINLY OVER THE
NCENTRAL LAKE WITH TERRAIN BETWEEN ISLE ROYALE AND THE KEWEENAW
ENHANCING EXPECTED WSW WIND. APPROACH OF TRAILING HI PRES WILL THEN
CAUSE QUICKLY DIMINISHING WINDS BY FRI WHICH WILL CONTINUE THRU FRI
NIGHT. OVER THE WEEKEND INTO EARLY NEXT WEEK...LAKE SUP WILL BE
DOMINATED BY S WINDS BETWEEN HI PRES MOVING INTO NEW ENGLAND AND A
LO PRES TROF IN THE PLAINS. THE STRONGEST S WINDS UP TO 25 KTS
DURING THIS PERIOD ARE MOST LIKELY OVER THE E HALF OF THE LAKE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KC
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1148 PM CST WED NOV 14 2012
.DISCUSSION...
SEE AVIATION FOR 06Z TAFS.
&&
.AVIATION...
AS S/W ENERGY MOVES FROM THE NORTHERN ROCKIES TO JUST WEST OF THE
GREAT LAKES AND THE CENTRAL U.S. ON THURSDAY...THE WEAK SFC RIDGE
OVER SOUTH CENTRAL TEXAS WILL MOVE FURTHER EAST...PROVIDING A MORE
CONSISTENT E TO SE SFC WIND PATTERN DURING THE DAY ON THURSDAY.
CIGS AROUND 3000 TO 6000 FT FROM VCNTY OF KDRT TO KUVA TONIGHT
WILL SPREAD SLIGHTLY FURTHER EAST AFTER 09Z THROUGH 18Z TO NEAR
AND WEST OF A LINE FROM KPEZ TO KSAT TO KERV. SCT TO BKN CLOUDS
ABOVE 25 THSD FT ARE EXPECTED VCNTY OF KAUS THROUGH 18Z THURSDAY.
AFTER 18Z ON THURSDAY SCT CLOUDS FROM 5 THSD TO 10 THSD FT ARE
EXPECTED...WITH HIGHER CIRRUS SCT TO BKN AT OR ABOVE 25 THSD FT.
BY THURSDAY EVENING SFC WINDS WILL BECOME E TO NE...AS THE S/W
FROM WEST OF THE GREAT LAKES TO THE CENTRAL U.S. MOVES TO THE
MISSISSIPPI VALLEY AND CAUSES A WEAK RIDGE TO FORM ACROSS THE
NORTHEAST TO EASTERN PART OF SOUTH CENTRAL TEXAS. THESE TYPE OF
WEATHER PATTERNS WILL FAVOR VFR CONDITIONS ON THURSDAY NIGHT...
WITH SCT CLOUDS AROUND 10 THSD FT AND SCT TO BKN HIGHER CIRRUS
AT OR ABOVE 25 THSD FT.
&&
.PREV DISCUSSION... /ISSUED 1000 PM CST WED NOV 14 2012/
UPDATE...
MADE MINOR CHANGES TO THE ONGOING FORECAST PACKAGE TO ACCOUNT FOR
CURRENT AND REST OF TONIGHT WEATHER TRENDS. LATEST 00Z NAM12 AND
03Z RUC13 AREA FORECAST SOUNDINGS SUGGEST/MAINTAIN A 850MB
BKN/OVC CLOUD LAYER TONIGHT INTO THURSDAY ACROSS THE SOUTHERN
HALF OF SOUTH CENTRAL TEXAS. HILL COUNTRY WILL REMAIN MOSTLY CLEAR
THIS EVENING WITH SOME CLOUDS RETURNING OVERNIGHT. ACROSS THE RIO
GRANDE PLAINS/EDWARDS PLATEAU AREA...EXPECT CLOUDS TO INCREASE
OVERNIGHT AS SURFACE DEWPOINTS AUGMENT AND MID TO UPPER LEVEL
MOISTURE MOVES FROM WEST TEXAS AND NORTHEAST MEXICO.
PREV DISCUSSION... /ISSUED 553 PM CST WED NOV 14 2012/
DISCUSSION...
SEE AVIATION FOR 00Z TAFS.
AVIATION...
A MID LEVEL CLOUD DECK EXTENDS FROM SOUTHEAST OF DEL RIO TO
SAN ANTONIO TO LA GRANGE AND SOUTH TO THE COAST. CIGS ACROSS
THIS AREA ARE VFR. TO THE NORTH SKIES ARE MAINLY CLEAR. THESE
CLOUDS ARE EXPECTED TO SLOWLY ERODE THROUGH THE EVENING. KAUS,
KSAT, KSSF AND KDRT WILL BE VFR THROUGH THE EVENING. AS S/W ENERGY
MOVES FROM THE NORTHERN ROCKIES TO JUST WEST OF THE GREAT LAKES
AND THE CENTRAL U.S. ON THURSDAY...THE WEAK SFC RIDGE OVER
SOUTH CENTRAL TEXAS WILL MOVE FURTHER EAST...PROVIDING A MORE
CONSISTENT E TO SE SFC WIND PATTERN FOR THE DAY ON THURSDAY.
THIS COULD CAUSE CIGS AROUND 2500 TO 6000 FT TO FORM NEAR THE
RIO GRANDE TONIGHT THROUGH THURSDAY MORNING IN VCNTY OF KDRT.
VFR CONDITIONS ARE EXPECTED TO CONTINUE AT KAUS, KSAT AND KSSF
THURSDAY MORNING. SCT TO BKN CLOUDS AOB 10 THSD FT WILL SLOWLY
INCREASE FROM THE WEST THROUGH THURSDAY AND THURSDAY NIGHT. BY
THURSDAY EVENING SFC WINDS WILL BECOME E TO NE...AS THE S/W FROM
WEST OF THE GREAT LAKES TO THE CENTRAL U.S. MOVES TO THE MS VALLEY
AND CAUSES A WEAK RIDGE TO FORM ACROSS THE NORTHEAST TO EASTERN
PART OF SOUTH CENTRAL TEXAS. THESE TYPE OF WEATHER PATTERNS WILL
FAVOR VFR CONDITIONS ON THURSDAY AFTERNOON AND EVENING.
PREV DISCUSSION... /ISSUED 312 PM CST WED NOV 14 2012/
DISCUSSION...
CLOUDS HAVE BEEN SLOW TO CLEAR/ERODE OVER THE SRN HALF OF THE CWA
TODAY. OVERRUNNING WAS OCCURRING IN THE SWLY FLOW 5-8K FEET ABOVE
THE COOL DRY SURFACE RIDGE. SOME PARTIAL CLEARING WILL CONTINUE
THIS EVENING...HOWEVER ADDITIONAL MID-UPPER LEVEL CLOUDS WERE
MOVING IN FROM THE WEST AS WELL AS INCREASING LOW LEVEL RETURN
MOISTURE UP THE RIO GRANDE. THE COOL SURFACE RIDGE OVER S TX WILL
SLOWLY RETREAT EASTWARD THURSDAY WITH RETURN FLOW ALL AREAS. A BRIEF
WEAK BACKDOOR COLD FRONT WILL AFFECT MAINLY NERN CWA THURSDAY
NIGHT/EARLY FRIDAY AND BRIEFLY SHIFT WINDS TO THE NE-E. THIS WEAK
FRONT COULD TRIGGER A FEW SHOWERS OVER THE FAR SWRN CWA AS WELL.
WINDS WILL QUICKLY RETURN TO SELY BY SATURDAY INTO SUNDAY AS THE
NWLY FLOW BECOMES MORE ZONAL FLOW. MINOR DISTURBANCES IN THE WESTERLY
FLOW COULD GENERATE ISOLATED SHOWERS/SPRINKLES SUNDAY INTO SUNDAY
NIGHT WITH PARTLY TO MOSTLY CLOUDY SKIES PREVAILING. A MORE POTENT
TROUGH/COLD FRONT WILL MOVE INTO SOUTHWEST TX MONDAY AND ACROSS
SOUTH TX MONDAY NIGHT AND TUESDAY...RESULTING IN BETTER CHANCES OF
CONVECTION. HAVE TONED DOWN GFS MOS POPS TO 20-30 PERCENT MORE IN
LINE WITH THE DRIER ECWMF AND PREVIOUS THINKING. CLEARING TUESDAY
NIGHT INTO WEDNESDAY BEHIND THE COLD FRONT. MILD HIGH TEMPERATURES
AND COOL NIGHTS AS AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 40 68 44 68 40 / 0 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 34 68 40 67 34 / 0 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 40 67 45 67 38 / 0 0 - 0 0
BURNET MUNI AIRPORT 35 66 41 66 37 / 0 0 0 0 0
DEL RIO INTL AIRPORT 48 68 51 65 48 / - 0 - - -
GEORGETOWN MUNI AIRPORT 35 67 37 66 36 / 0 0 0 0 0
HONDO MUNI AIRPORT 45 66 49 67 42 / 0 0 - - 0
SAN MARCOS MUNI AIRPORT 40 66 44 67 39 / 0 0 - 0 0
LA GRANGE - FAYETTE REGIONAL 37 68 42 67 39 / 0 0 - - -
SAN ANTONIO INTL AIRPORT 44 65 49 66 43 / 0 0 - - 0
STINSON MUNI AIRPORT 46 66 51 66 44 / 0 0 - - 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...08
SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
850 PM EST FRI NOV 16 2012
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH THE
WEEKEND. LOW PRESSURE WILL SLOWLY MAKE ITS WAY NORTH ALONG AND
EAST COAST OF THE UNITED STATES THROUGH THE MIDDLE OF NEXT WEEK.
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE OHIO VALLEY INTO
OUR REGION ON TUESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 845 PM EST FRIDAY...
A DRY UPPER LEVEL SHORTWAVE TROF SEEN ON WATER VAPOR SATELLITE
IMAGERY JUST TO WEST THIS EVENING WILL WEAKEN TONIGHT AS A RIDGE
OF HIGH PRESSURE AT THE SURFACE BUILDS INTO OUR AREA.
THIS SHOULD ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS IN THE
VALLEYS TONIGHT. A FEW HIGH CLOUDS ACROSS NW NC INTO FAR SOUTHWEST
VA SHOULD ERODE PER FORECAST SOUNDINGS AND RAP UPPER LEVEL RH
FORECAST. TRIED TO ILLUSTRATE A LARGER DIFFERENCE IN LOWS FROM
RIDGES TO VALLEYS WITH FCX VWP SHOWING NORTHEAST WINDS HAVE
INCREASED TO 25KTS. AS A RESULT...PUSHED UP LOW AT ROA AND
BLF...BUT CONTINUE TO GO BELOW GUIDANCE FOR LOWS IN VALLEY
LOCATIONS.
ON SATURDAY...HIGH PRESSURE AND PLENTY OF SUNSHINE WILL PREVAIL.
HIGH TEMPERATURES ARE EXPECTED TO BE COMPARABLE OR SLIGHTLY MILDER
THAN THOSE REALIZED TODAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 305 PM FRIDAY...
RATHER DRY AIRMASS WILL REMAIN IN PLACE EARLY SAT EVENING BUT THE
LOW LVL FLOW WILL INCREASE OFF THE ATLANTIC AS UPPER LOW SHIFTS EAST
OVER THE SOUTHEAST U.S. THIS IS THE MAIN ISSUE FOR THE FORECAST TO
FINISH OUT THE WEEKEND AND GOING INTO EARLY NEXT WEEK. MODELS ARE
SIMILAR IN THE WEDGE REMAINING IN PLACE BUT DIFFER IN TERMS OF HOW
FAR WEST THE LOWER CLOUDS MOVE IN. THINK THE NAM IS ON THE RIGHT
TRACK WITH INCREASING ATLANTIC MOISTURE MOVING INTO THE PIEDMONT
AREA BY DAWN SUNDAY...WITH THE CMC/GFS FOLLOWING SUIT ON SUNDAY. THE
WWD EXTEND THRU SUNDAY WILL BE UP TO THE BLUE RIDGE AND HOW MUCH DRY
AIR IS DISPLACED WILL BE THE DIFFERENCE BETWEEN LESS CLOUDS AND
COLDER LOWS TO THE WEST AND BKN SKIES AND SOMEWHAT WARMER TEMPS IN
THE EAST. THIS HAS THE POTENTIAL TO BUST ONE WAY OR THE OTHER IF THE
CLOUDS DO NOT ADVECT IN/DEVELOP AS FORECAST...MEANING COLDER LOWS.
CONFIDENCE IS LOW ON THE OTHER SCENARIO OF SEEING OVC SKIES ALL THE
WAY TO THE WV BORDER PER NAM.
SUNDAY SHOULD BE MAINLY DRY WITH CLOUDS TRYING TO ERODE FROM THE
SOUTHWEST OUTSIDE THE HIGH PRESSURE WEDGE...BUT THINK THE EASTERN
FORECAST AREA SHOULD STAY MOSTLY CLOUD ALL DAY. COULD EVEN SQUEEZE
OUT SOME LIGHT RAIN EAST OF DANVILLE. HIGHS WILL BE AFFECTED AGAIN
WITH THE WEDGE. WENT BELOW MOS GUIDANCE OUT EAST WHERE HIGHS MAY
STRUGGLE TO REACH 50...WHILE THE SW MTNS OVER BLF-RICHLANDS SEE
TEMPS RISE TOWARD 60. SHARP GRADIENT IN CLOUDS VS SUN IS EXPECTED.
HEADING INTO SUNDAY NIGHT INTO MONDAY WILL CONTINUE TO SEE THE UPPER
LOW SHIFT OFF THE SOUTHEAST COAST WITH SFC LOW FORMING WELL EAST OF
THE COASTLINE. STILL MOISTURE WILL STREAM WEST ON THE NORTH SIDE OF
THE SYSTEM AND WILL SEE POTENTIAL FOR LIGHT RAIN AND/OR DRIZZLE
SOUTHEAST OF THE BLUE RIDGE. KEPT POPS ONLY IN THE SLIGHT CHANCE
RANGE MONDAY EAST OF A LYH/DAN LINE AND ACROSS THE SRN BLUE RIDGE
PER SOME UPSLOPE. ADDED DRIZZLE AS WELL FURTHER NORTH OVER THE NEW
RIVER VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 314 EST FRIDAY...
PERSISTENT LLVL NORTHERLY FLOW AND MOISTURE WILL LEAD TO CLOUDS AND
LIGHT SHOWERS AT TIMES EARLY NEXT WEEK. AFTER AN UPPER LEVEL TROUGH
PASSES THROUGH MIDWEEK...WINDS WILL SHIFT TO A DOWNSLOPING
DIRECTION...SUCH THAT CLEARING AND WARMING WILL ENSUE. WITH H85
TEMPS AROUND +8C BY THE END OF THE WEEK WITH A VERY DRY
PROFILE...THANKSGIVING DAY LOOKS WARM AND CLEAR...WITH SOME OF THE
CITIES MAKING A RUN TOWARDS 70F THURSDAY AND FRIDAY. THERE SHOULD BE
ZERO TRAVEL CONCERNS FOR THIS PART OF THE COUNTRY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1210 PM EST FRIDAY...
VFR CONDITIONS AND LIGHT SURFACE WINDS ARE EXPECTED THROUGH
SATURDAY AS HIGH PRESSURE BUILDS ACROSS THE AREA. POSSIBLY ENOUGH
GRADIENT SATURDAY AFTERNOON FOR SOME 18KT GUSTS FROM THE NE AT
LYH/DAN.
AREAS OF MVFR AND IFR CIGS AND VSBYS POSSIBLE SUNDAY INTO EARLY
NEXT WEEK WITH THE POTENTIAL FOR STRONG INVERSION SURFACE WEDGE
ACROSS THE REGION...ESPECIALLY ALONG AND EAST OF THE CREST OF THE
BLUE RIDGE.
UPPER DISTURBANCE ON TUESDAY MAY HELP TO WEAKEN THE WEDGE BUT ALSO
INTRODUCE THE POTENTIAL FOR ISOLATED SHOWERS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...PH
SHORT TERM...WP
LONG TERM...KM
AVIATION...DS/KM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
155 AM MST SAT NOV 17 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
05Z WATER VAPOR IMAGERY RUC ANALYSIS INDICATED RIDGE AXIS IN PLACE
ACROSS THE MISSOURI VALLEY WITH STRONG SHORT WAVE TROUGH NEARING THE
PAC NORTHWEST. 00Z SOUNDINGS INDICATED A FAIRLY LARGE DIFFERENCE IN
THE LARGE SCALE AIR MASS BETWEEN DNR AND LBF/DDC. AT
LBF/DDC...STRONG INVERSION WAS NOTED BETWEEN H8 AND H7 MAKING
OVERALL AIR MASS VERY STABLE. IN ADDITION TO THE STABLE
LAYER...MIXING RATIOS INDICATED A FAIRLY DEEP MOIST LAYER ENDING
AROUND H8. AT DNR...NEARLY DRY ADIABATIC LAPSE RATES NOTED BETWEEN
H75 AND H55 WITH MIXING RATIOS DROPPING RAPIDLY ABOVE THE SFC LAYER.
AT THE SFC...TROUGH AXIS WAS LOCATED ACROSS EASTERN COLORADO.
TODAY-TOMORROW...SEVERAL WEAK/LOW AMPLITUDE SHORT WAVE TROUGHS WILL
MOVE ACROSS THE REGION THROUGH THE PERIOD EACH BRINGING A BRIEF
PERIOD OF FORCED ASCENT ACROSS THE CWA. FOR THE MOST PART...SEEMS
UNLIKELY THAT LIFT WELL BE ABLE TO SATURATE AND NEAR SFC OR MID
LEVEL LAYERS THROUGH TONIGHT AND WHILE ELEVATED THETA E LAPSE RATES
SUPPORT THE POSSIBILITY OF POTENTIAL INSTABILITY...THINK VERTICAL
MOISTURE PROFILES MAKE THIS VERY UNLIKELY. MODELS DIVERGE A BIT MORE
ON SUNDAY WITH HANDLING OF NEXT TROUGH WHICH WILL PROVIDE NOTICEABLY
STRONGER FORCING AS IT MORE DIRECTLY MOVES OVER CWA. MAJORITY OF
MODELS AND GEFS ENSEMBLES SUPPORT PRECIPITATION THREAT ACROSS
EASTERN KANSAS...WHILE NAM AND SREF SUGGESTING POCKET OF ELEVATED
CAPE WILL DEVELOP ACROSS SOUTHEASTERN CWA AS TROUGH PASSES. BASED ON
MODEL CONSENSUS WILL WEIGHT FORECAST MORE TOWARDS THE EASTERN KS
SOLUTIONS...BUT DID UP POPS TO AROUND 10 PERCENT IN THE EAST SINCE
LAPSE RATES WOULD SUPPORT INSTABILITY DEVELOPMENT SHOULD ANY
MEANINGFUL MOISTURE ADVECTION OCCUR. THE OTHER POTENTIAL FOR SENSIBLE
WEATHER WILL BE THE THREAT OF FOG/STRATUS EARLY THIS MORNING AND
AGAIN SUNDAY MORNING. WITH WINDS STAYING IN THE 5 TO 10 KT RANGE
AHEAD OF SFC TROUGH...NOT REALLY CONFIDENT IN FOG FORMATION. HOWEVER
BASED ON OBSERVED SOUNDINGS SHOWING A FAIRLY DEEP NEAR SFC MOIST
LAYER...WILL LEAVE A PATCHY MENTION IN AREAS MOST LIKELY TO DECOUPLE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
SUNDAY NIGHT-MONDAY NIGHT...ZONAL FLOW ALOFT WILL GRADUALLY SHIFT
TO SHORT WAVE RIDGING TOWARDS THE END OF THE PERIOD...WITH DRY AND
OVERALL QUIET CONDITIONS EXPECTED TO CONTINUE. TEMPERATURES WILL
GRADUALLY WARM THROUGH THE PERIOD...WITH A FEW LOCATIONS NEARING
70 BY MONDAY.
TUESDAY-FRIDAY...
PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK WELL NORTH OF CWA
ALONG CANADIAN BORDER AND WEAKER SOUTHERN TRACK ACROSS SOUTHERN
PLAINS IS EXPECTED THROUGH THE EXTENDED PERIOD. RESULT OF THIS
PATTERN WILL BE ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
PERSISTING OVER THE CWA. A SHORTWAVE RIDGE BEGINS TO BUILD INTO THE
INTER-MOUNTAIN WEST TUESDAY AND THEN ACROSS THE PLAINS ON
WEDNESDAY...WHEN HIGH TEMPS IN THE UPPER 60S/NEAR 70 ARE EXPECTED.
RH VALUES ON WEDNESDAY COULD APPROACH CRITICAL LEVELS...HOWEVER
WINDS SHOULD REMAIN WELL BELOW RED FLAG CRITERIA. WHILE THERE WILL
BE A SLIGHTLY COOLER AIR MASS BEHIND A WEAK COLD FRONT WE SHOULD
STILL SEE ABOVE NORMAL TEMPS THURSDAY AND FRIDAY WITH HIGHS IN THE
UPPER 50S/LOW 60S AND LOWS IN THE 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1000 PM MST FRI NOV 16 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT KGLD WITH
MVFR/POSSIBLY IFR AT KMCK. A NARROW NEARLY NORTH TO SOUTH RIBBON
OF PATCHY FOG/STRATUS IS EXPECTED TO DEVELOP IN SOUTHWESTERN
NEBRASKA SOUTHWARD EARLY SATURDAY MORNING...WHICH MAY CAUSE MVFR/IFR
VISIBILITIES AT KMCK. OTHERWISE...A FEW MID TO HIGH LEVEL CLOUDS
THROUGH THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...99
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1227 AM EST SAT NOV 17 2012
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH THE
WEEKEND. LOW PRESSURE WILL SLOWLY MAKE ITS WAY NORTH ALONG AND
EAST COAST OF THE UNITED STATES THROUGH THE MIDDLE OF NEXT WEEK.
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE OHIO VALLEY INTO
OUR REGION ON TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 845 PM EST FRIDAY...
A DRY UPPER LEVEL SHORTWAVE TROF SEEN ON WATER VAPOR SATELLITE
IMAGERY JUST TO WEST THIS EVENING WILL WEAKEN TONIGHT AS A RIDGE
OF HIGH PRESSURE AT THE SURFACE BUILDS INTO OUR AREA.
THIS SHOULD ALLOW FOR GOOD RADIATIONAL COOLING CONDITIONS IN THE
VALLEYS TONIGHT. A FEW HIGH CLOUDS ACROSS NW NC INTO FAR SOUTHWEST
VA SHOULD ERODE PER FORECAST SOUNDINGS AND RAP UPPER LEVEL RH
FORECAST. TRIED TO ILLUSTRATE A LARGER DIFFERENCE IN LOWS FROM
RIDGES TO VALLEYS WITH FCX VWP SHOWING NORTHEAST WINDS HAVE
INCREASED TO 25KTS. AS A RESULT...PUSHED UP LOW AT ROA AND
BLF...BUT CONTINUE TO GO BELOW GUIDANCE FOR LOWS IN VALLEY
LOCATIONS.
ON SATURDAY...HIGH PRESSURE AND PLENTY OF SUNSHINE WILL PREVAIL.
HIGH TEMPERATURES ARE EXPECTED TO BE COMPARABLE OR SLIGHTLY MILDER
THAN THOSE REALIZED TODAY.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 305 PM FRIDAY...
RATHER DRY AIRMASS WILL REMAIN IN PLACE EARLY SAT EVENING BUT THE
LOW LVL FLOW WILL INCREASE OFF THE ATLANTIC AS UPPER LOW SHIFTS EAST
OVER THE SOUTHEAST U.S. THIS IS THE MAIN ISSUE FOR THE FORECAST TO
FINISH OUT THE WEEKEND AND GOING INTO EARLY NEXT WEEK. MODELS ARE
SIMILAR IN THE WEDGE REMAINING IN PLACE BUT DIFFER IN TERMS OF HOW
FAR WEST THE LOWER CLOUDS MOVE IN. THINK THE NAM IS ON THE RIGHT
TRACK WITH INCREASING ATLANTIC MOISTURE MOVING INTO THE PIEDMONT
AREA BY DAWN SUNDAY...WITH THE CMC/GFS FOLLOWING SUIT ON SUNDAY. THE
WWD EXTEND THRU SUNDAY WILL BE UP TO THE BLUE RIDGE AND HOW MUCH DRY
AIR IS DISPLACED WILL BE THE DIFFERENCE BETWEEN LESS CLOUDS AND
COLDER LOWS TO THE WEST AND BKN SKIES AND SOMEWHAT WARMER TEMPS IN
THE EAST. THIS HAS THE POTENTIAL TO BUST ONE WAY OR THE OTHER IF THE
CLOUDS DO NOT ADVECT IN/DEVELOP AS FORECAST...MEANING COLDER LOWS.
CONFIDENCE IS LOW ON THE OTHER SCENARIO OF SEEING OVC SKIES ALL THE
WAY TO THE WV BORDER PER NAM.
SUNDAY SHOULD BE MAINLY DRY WITH CLOUDS TRYING TO ERODE FROM THE
SOUTHWEST OUTSIDE THE HIGH PRESSURE WEDGE...BUT THINK THE EASTERN
FORECAST AREA SHOULD STAY MOSTLY CLOUD ALL DAY. COULD EVEN SQUEEZE
OUT SOME LIGHT RAIN EAST OF DANVILLE. HIGHS WILL BE AFFECTED AGAIN
WITH THE WEDGE. WENT BELOW MOS GUIDANCE OUT EAST WHERE HIGHS MAY
STRUGGLE TO REACH 50...WHILE THE SW MTNS OVER BLF-RICHLANDS SEE
TEMPS RISE TOWARD 60. SHARP GRADIENT IN CLOUDS VS SUN IS EXPECTED.
HEADING INTO SUNDAY NIGHT INTO MONDAY WILL CONTINUE TO SEE THE UPPER
LOW SHIFT OFF THE SOUTHEAST COAST WITH SFC LOW FORMING WELL EAST OF
THE COASTLINE. STILL MOISTURE WILL STREAM WEST ON THE NORTH SIDE OF
THE SYSTEM AND WILL SEE POTENTIAL FOR LIGHT RAIN AND/OR DRIZZLE
SOUTHEAST OF THE BLUE RIDGE. KEPT POPS ONLY IN THE SLIGHT CHANCE
RANGE MONDAY EAST OF A LYH/DAN LINE AND ACROSS THE SRN BLUE RIDGE
PER SOME UPSLOPE. ADDED DRIZZLE AS WELL FURTHER NORTH OVER THE NEW
RIVER VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 314 EST FRIDAY...
PERSISTENT LLVL NORTHERLY FLOW AND MOISTURE WILL LEAD TO CLOUDS AND
LIGHT SHOWERS AT TIMES EARLY NEXT WEEK. AFTER AN UPPER LEVEL TROUGH
PASSES THROUGH MIDWEEK...WINDS WILL SHIFT TO A DOWNSLOPING
DIRECTION...SUCH THAT CLEARING AND WARMING WILL ENSUE. WITH H85
TEMPS AROUND +8C BY THE END OF THE WEEK WITH A VERY DRY
PROFILE...THANKSGIVING DAY LOOKS WARM AND CLEAR...WITH SOME OF THE
CITIES MAKING A RUN TOWARDS 70F THURSDAY AND FRIDAY. THERE SHOULD BE
ZERO TRAVEL CONCERNS FOR THIS PART OF THE COUNTRY.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1220 AM EST SATURDAY...
VFR CONDITIONS AND LIGHT SURFACE WINDS ARE EXPECTED THIS EVENING AS
HIGH PRESSURE REMAINS ACROSS THE REGION.
AREAS OF MVFR AND IFR CIGS AND VSBYS POSSIBLE LATE TONIGHT INTO
MONDAY WITH A STRONG INVERSION SURFACE WEDGE ACROSS THE
REGION...ESPECIALLY ALONG AND EAST OF THE CREST OF THE BLUE RIDGE.
EXPECT ANY LOWER CEILINGS WILL NOT DEVELOP UNTIL AFTER THE 06Z END
OF THE TAF FORECAST PERIOD.
AN UPPER DISTURBANCE ON TUESDAY WILL WEAKEN THE WEDGE...BUT WILL ALSO
INTRODUCE THE POTENTIAL FOR ISOLATED SHOWERS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...PH
SHORT TERM...WP
LONG TERM...KM
AVIATION...AMS/DS/KM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
332 AM CST SAT NOV 17 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
TODAY...EXPANDED DENSE FOG ADVISORY TO COVER THE REMAINDER OF
SOUTHEAST WISCONSIN AND NORTHERN SOUTH CENTRAL WISCONSIN AS
STRATUS IS SPREADING NORTHEAST. ALSO EXTENDED END TIME TO 9 AM CST
AS FORECAST SOUNDINGS SHOW LITTLE MIXING UNTIL THEN.
TIMING OF FOG AND LOW CLOUD DISSIPATION THIS MORNING WILL HAVE AN
IMPACT ON HIGH TEMPERATURES TODAY. MODELS IN GOOD AGREEMENT THAT
925 MB TEMPERATURES WILL BE IN THE +5C TO +6C RANGE...WITH +7C IN
THE FAR WEST...BY MID TO LATE AFTERNOON. NAM/GFS MODEL SOUNDINGS
MIXING DRY ADIABATICALLY TO THESE TEMPS ARE YIELDING LOW TO MID
50S HIGHS.
HOWEVER...WITH WARM AIR ADVECTION ON SOUTHWEST WINDS INCREASING TO
20-25 KNOT WINDS AT/ABOVE 1K FT OVER WEAKER SOUTHEAST WINDS THAT
WILL BE KEEPING THE NEAR SURFACE AIR COOLER...THE RAP SOUNDINGS
NEVER FULLY MIX OUT THE BOUNDARY LAYER INVERSION TO REACH 925 MB.
WENT WITH A BLENDED SOLUTION THAT LEANS TOWARD THE WARM SIDE IN
THE CURRENT FOG-FREE AREAS IN THE WEST...AND IS COOLER EAST WHERE
THE COMBINATION OF EARLY FOG...AND SOUTHEAST WINDS OFF THE MID-
UPPER 40 DEGREE LAKE WATER WILL LIMIT HIGHS.
TONIGHT...GRADIENT SHOULD BE SUFFICIENT FOR SOUTHERLY WINDS TO
KEEP THE BOUNDARY LAYER MIXED AND PREVENT FOG TONIGHT. EXPECT ONLY
SOME MID-HIGH LEVEL CLOUDS WITH A WEAK SHORT WAVE CROSSING REGION
OVERNIGHT.
.SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
SOUTHWEST 500MB FLOW IS DEPICTED BY THE SHORT TERM MODELS ACROSS
THE REGION SUNDAY INTO MONDAY. SHORTWAVE TROUGH MOVES THROUGH THE
AREA FROM THE SOUTHWEST LATE SUNDAY NIGHT AND MONDAY...WITH A
TRAILING SHORTWAVE THEN SHIFTING EAST SOUTHEAST INTO THE AREA
MONDAY NIGHT. AT THE SURFACE...MILD SOUTHERLY FLOW CONTINUES
ACROSS THE REGION SUNDAY INTO MONDAY...WITH A SURFACE TROUGH
MOVING EASTWARD INTO THE AREA MONDAY NIGHT.
AREA FORECAST SOUNDINGS FROM NAM/GFS SHOW SOME MID TO HIGH CLOUDS
SUNDAY INTO SUNDAY NIGHT...WITH MORE CLOUDS MONDAY/MONDAY NIGHT
WITH PASSAGE OF SHORTWAVES AND SURFACE TROUGH. SOUNDINGS DO
INDICATE AIR COLUMN BECOMING MOIST IN THE LOW LEVELS MONDAY
NIGHT...BUT THE MID TO UPPER LEVELS DRY OUT. LIGHT QPF IS SEEN
ACROSS PORTIONS OF THE AREA MONDAY AND MONDAY NIGHT.
CONTINUED TO MENTION LOW END POPS FOR MONDAY AND MONDAY NIGHT.
TEMPERATURES WILL REMAIN ABOVE NORMAL...WITH HIGHS WELL INTO THE
50S SUNDAY AND MONDAY PER NAM 925MB TEMPERATURES. LOWS WILL
MODERATE FROM THE 30S SUNDAY NIGHT TO THE LOWER TO MID 40S MONDAY
NIGHT.
.TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
GFS AND ECMWF SHOW GOOD AGREEMENT WITH FEATURES TUESDAY THROUGH
WEDNESDAY NIGHT. THEY SHOW THE SHORTWAVE TROUGH PUSHING THROUGH
AND EAST OF THE AREA TUESDAY. AREA GFS FORECAST SOUNDINGS SHOW
SOME LOW LEVEL MOISTURE LINGERING...BUT A DRY AIR COLUMN ABOVE IT.
KEPT LOW POPS TUESDAY MORNING IN THE FAR EAST/SOUTHEAST COUNTIES
IN THE MORNING...THEN DRY IN THE AFTERNOON.
BOTH MODELS THEN SHOW A 500MB RIDGE AXIS PASSING THROUGH THE AREA
TUESDAY NIGHT AND WEDNESDAY...WITH SOUTHWEST FLOW IN PLACE
WEDNESDAY NIGHT. SOUTH TO SOUTHWEST FLOW IN THE LOW LEVELS WITH
WARM AIR ADVECTION WILL OCCUR ACROSS THE REGION. AREA GFS FORECAST
SOUNDINGS REMAIN DRY DURING THIS TIME.
THUS...QUIET WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH ABOVE NORMAL TEMPERATURES CONTINUING. GIVEN THE
EXPECTED NAM 925MB TEMPERATURES...MAY REACH AS HIGH AS AROUND 60
ON WEDNESDAY.
.THANKSGIVING DAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
GFS AND ECMWF THEN DIFFER SOMEWHAT WITH FEATURES THURSDAY THROUGH
FRIDAY. THE GFS AND ECMWF BRING DEVELOPING LOW PRESSURE EAST FROM
NORTHERN MINNESOTA TO LAKE SUPERIOR THURSDAY...THEN NORTHEAST AS
IT BECOMES STRONGER THURSDAY NIGHT AND FRIDAY.
THE GFS HAS A COLD FRONT WITH LIGHT QPF MOVING EAST THROUGH THE
AREA THANKSGIVING DAY...FOLLOWED BY A STRONG VORTICITY MAXIMUM
PASSING THROUGH THURSDAY NIGHT INTO FRIDAY. THEY BOTH DO SHOW
BRISK WEST/NORTHWEST WINDS BRINGING COLDER AIR INTO THE REGION
THURSDAY NIGHT INTO FRIDAY. THE ECMWF BRINGS A DRY COLD FRONTAL
PASSAGE THURSDAY NIGHT. IT ALSO BRINGS A SECONDARY VORTICITY
MAXIMUM THROUGH THE AREA FRIDAY.
FOR NOW...WILL USE BLENDED POPS AND TEMPERATURES FOR THANKSGIVING
DAY THROUGH FRIDAY. THIS WILL MEAN DRY CONDITIONS AND CONTINUED
MILD TEMPERATURES. HIGHS THANKSGIVING DAY SHOULD REACH WELL INTO
THE 50S BEFORE THE FRONT MOVES THROUGH.
&&
.AVIATION/12Z TAFS/...WILL KEEP IFR/LIFR CONDITIONS AT AREA TAF
SITES UNTIL AT LEAST 13Z...AND POSSIBLY 14-15Z IN THE EAST...UNTIL
DAYTIME MIXING INCREASES WINDS AND RAISES CIGS AND VISIBILITIES.
SHOULD SEE VFR CONDITIONS ACROSS THE FORECAST AREA BY MID TO LATE
MORNING...WITH QUIET WEATHER THEN EXPECTED THROUGH THE REST OF THE
FORECAST PERIOD WITH VFR CONDITIONS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ046-047-
051-052-057>060-063>066-068>072.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
200 AM CST SAT NOV 17 2012
.SHORT TERM...THROUGH MONDAY NIGHT
200 AM CST SAT NOV 17 2012
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES SUNDAY NIGHT INTO MONDAY
NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OFF BRITISH COLUMBIA...SUBTROPICAL RIDGING FROM
NORTHERN MEXICO TO LAKE ERIE...AND SHORTWAVES RIDING IN THE
SOUTHWEST SUBTROPICAL FLOW JUST OFF THE CALIFORNIA COAST AND NEAR
THE WY/SOUTH DAKOTA BORDER. THIS LATTER SHORTWAVE WAS PRODUCING A
MASS OF CIRRUS ACROSS THE DAKOTAS INTO NORTHWEST MINNESOTA. DRY LOW
TO MID LEVELS SEEN ON THE 00Z MPX...ABR AND UNR SOUNDINGS HAS
PREVENTED ANY LOWER CLOUD DEVELOPMENT. REGARDING THE DRYNESS...BOTH
MPX AND ABR SOUNDINGS ONLY HAD PRECIPITABLE WATER VALUES OF 0.20
INCHES. FARTHER TO THE EAST...AN AREA OF LOW STRATUS WAS PRESENT
ACROSS MUCH OF GRBS FORECAST AREA INTO LOCATIONS ALONG/NORTHEAST OF
I-94 IN OUR AREA. THIS STRATUS FORMED FROM SOUTHEAST ADVECTION OF
MOISTURE OFF LAKE MICHIGAN UNDERNEATH A SUBSIDENCE INVERSION...
COMBINED WITH LIGHT WINDS AND CLEAR SKIES EARLIER IN THE EVENING. A
STRONGER SOUTH FLOW ON THE BACK SIDE OF HIGH PRESSURE OVER LOWER
MICHIGAN HAS HELPED KEEP THE REST OF THE AREA LOW CLOUD FREE. THIS
FLOW...WHICH STRENGTHENS HEADING WEST TOWARDS THE DAKOTAS...HAS BEEN
BRINGING WARMER AIR INTO THE REGION. RAP ANALYSIS SHOWED 925MB TEMPS
OF 7C AT MPX COMPARED TO 2C ON THE 00Z SOUNDING. SURFACE
TEMPERATURES HAVE REFLECTED THE WARM ADVECTION WITH READINGS FROM
THE MID 20S TO MID 30S...WARMEST WEST OF THE MISSISSIPPI RIVER.
TODAY AND TONIGHT...THE SHORTWAVE ALONG THE WYOMING/SOUTH DAKOTA
BORDER IS PROGGED TO LIFT INTO NORTHERN MINNESOTA TONIGHT. THE TRACK
IS SLIGHTLY FARTHER NORTH THAN 24 HOURS AGO. WITH THE FARTHER NORTH
TRACK...THERE SHOULD BE A LITTLE LESS CLOUDS. SOME OF THE CIRRUS
STILL LOOKS SLATED TO CROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...WITH SOME ALTOSTRATUS PRODUCED BY ISENTROPIC
LIFT AFTER MIDNIGHT. PLENTY OF LOW LEVEL DRY AIR WILL RESULT IN A
CONTINUATION OF THE DRY FORECAST. ONLY OTHER CLOUD COVER OF NOTE IS
THE EARLY MORNING STRATUS OVER THE NORTHEAST PORTION OF THE FORECAST
AREA...WHICH SHOULD SHIFT NORTHEAST DURING THE MORNING WITH THE
INCREASING SOUTH TO SOUTHWEST 950-925MB FLOW. THIS FLOW IS PROGGED
TO REACH 25-30KT TODAY AS THE GRADIENT TIGHTENS. WITH PLENTY OF
SUN...EXPECT BREEZY CONDITIONS...PARTICULARLY ON THE HIGHER TERRAIN
WEST OF THE MISSISSIPPI RIVER WHICH IS MORE EXPOSED AND IN THE
TIGHTEST GRADIENT. THE BREEZE SHOULD PERSIST INTO TONIGHT WITH THE
STRENGTHENING OF THE LOW LEVEL JET...NOTED TOO BY 950-925MB WINDS
INCREASING TO 30-45KT. THESE WINDS WILL CONTINUE TO BRING WARMER AIR
INTO THE REGION WITH 925MB TEMPS INDICATED BETWEEN 4-6C AT 18Z.
THESE SUPPORT HIGHS IN THE LOW TO MID 50S. FOLLOWED A BLEND OF
GUIDANCE FOR LOWS TONIGHT WITH THE BREEZE AND PASSING CLOUDS HELPING
TO PRODUCE A WARMER NIGHT.
SUNDAY INTO SUNDAY NIGHT...ATTENTION FOCUSES TO THE SHORTWAVE OFF
THE CALIFORNIA COAST. GOOD MODEL AGREEMENT EXISTS THAT THIS
SHORTWAVE WILL LIFT INTO THE CENTRAL PLAINS BY LATE SUNDAY...THEN
INTO WESTERN PORTIONS OF MINNESOTA AND IOWA BY 12Z MONDAY. RIDGING
LOOKS TO DEVELOP OVER THE FORECAST AREA FOR A TIME AHEAD OF THIS
SHORTWAVE AND IN THE WAKE OF THE SHORTWAVE LIFTING OUT OF NORTHERN
MINNESOTA. SUBSIDENCE UNDER THE RIDGE SHOULD THIN CLOUDS OUT SOME
FOR MUCH OF THE DAY UNTIL LATE. THIS IS WHEN THE AREA BEGINS TO FEEL
THE MOISTURE ADVECTION EFFECTS AHEAD OF THE SHORTWAVE...WHICH WILL
START PRODUCING AN ALTOSTRATUS DECK IN THE EVENING ACROSS THE AREA.
FURTHER LOWERING OF CEILINGS WILL OCCUR THROUGH THE NIGHT AS
PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.5 INCH AT 00Z TO NEAR
0.75 INCHES AT 12Z MONDAY. ALTHOUGH MOISTURE INCREASES...THE
ISENTROPIC LIFT IS QUITE WEAK...FOCUSED MAINLY WEST OF A LINE FROM
MEDFORD TO LA CROSSE AND OELWEIN BETWEEN 06-12Z. HAVE MAINTAINED A
20-30 PERCENT CHANCE FOR THIS AREA AND TIME PERIOD...BUT GIVEN THE
WEAK LIFT SIGNATURE IT IS POSSIBLE ANY PRECIPITATION HOLDS OFF UNTIL
AFTER 12Z MONDAY AS SUGGESTED BY THE 17.00Z GFS/NAM. 17.00Z ECMWF IS
MORE ROBUST...THOUGH. WARMER 925MB TEMPS IN THE 5-7C RANGE AT 18Z
SUNDAY PLUS THE SOUTHERLY BREEZE AND SUN SHOULD YIELD HIGHS IN THE
MID TO UPPER 50S. A FEW LOCATIONS MAY REACH OR EXCEED 60...
ESPECIALLY IF MORE SUN OCCURS. EVEN A WARMER NIGHT SHOULD OCCUR
SUNDAY NIGHT WITH MORE MOISTURE...CLOUDS AND THE BREEZE. LOWS WEST
OF THE MISSISSIPPI RIVER MAY NOT DIP BELOW 40.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE TROUGH OVER THE PLAINS
MODELS AGREE ON BRINGING IT ACROSS THE FORECAST AREA MONDAY EVENING.
AS THE TROUGH APPROACHES MONDAY...THE ISENTROPIC LIFT LOOKS TO
INCREASE A LITTLE...ENOUGH TO WARRANT PRECIPITATION CHANCES AS HIGH
AS 40 PERCENT. KEPT THESE CHANCES LOW BECAUSE BOTH THE 17.00Z GFS
AND NAM SHOW A DRY LOOK TO THEIR QPF FIELDS. THE ECMWF REMAINS THE
MOST ROBUST...THOUGH ITS LATEST 17.00Z RUN HAS A SLIGHTLY DRIER LOOK
THAN ITS PREVIOUS 16.12Z RUN. MUCH OF THE RAIN...IF IT OCCURS...
SHOULD BE EAST OF THE AREA BY 00Z. HOWEVER...HAVE MAINTAINED A 20
PERCENT CHANCE OVER FAR EASTERN AREAS FROM 00-06Z SINCE THERE IS
STILL WEAK ISENTROPIC LIFT INDICATED ON THE 290-295K SURFACES.
PLENTY OF CLOUDS ON MONDAY WILL PREVENT TEMPERATURES FROM RISING AS
MUCH COMPARED TO THE WEEKEND. HAVE FOLLOWED A BLEND OF GUIDANCE FOR
HIGHS. CLOUDS GRADUALLY CLEARING OUT WEST TO EAST MONDAY NIGHT PLUS
LIGHTER WINDS RESULTING FROM A WEAKER PRESSURE GRADIENT SHOULD ALLOW
TEMPERATURES TO DIP INTO THE 30S TO AROUND 40 AT MOST LOCATIONS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
200 AM CST SAT NOV 17 2012
THE MAIN ISSUE IN THE LONG TERM FORECAST IS A VERY POTENT SHORTWAVE
COMING OUT OF THE NORTHEAST PACIFIC TROUGH AND ENTERING THE PACIFIC
NORTHWEST TUESDAY EVENING. ALL MODELS AGREE ON UPPER RIDGING
BUILDING AHEAD OF THE POTENT SHORTWAVE INTO THE FORECAST AREA
TUESDAY NIGHT...RESULTING IN A SURGE OF WARM AIR ADVECTING INTO THE
AREA. 925MB TEMPS CLIMB FROM AROUND 6C AT 18Z TUESDAY TO 10-12C AT
18Z WEDNESDAY. 850MB TEMP ANOMALIES ON WEDNESDAY ARE 1.5 STANDARD
DEVIATIONS ABOVE NORMAL. PLENTY OF SUN LOOKS TO OCCUR AT LEAST ON
WEDNESDAY...AND PERHAPS TUESDAY TOO DEPENDING ON WHEN LOW CLOUDS
CLEAR ASSOCIATED WITH THE MONDAY/MONDAY NIGHT SHORTWAVE.
THEREFORE...THERE SHOULD BE DECENT MIXING DESPITE THE SHORTER DAY
LENGTH. HAVE LEANED ON THE WARM SIDE OF GUIDANCE AS A RESULT...
ESPECIALLY WEDNESDAY WHEN HIGHER CONFIDENCE EXISTS OF FULL SUN AND A
SOUTHERLY BREEZE IS PRESENT. HIGHS WEDNESDAY COULD REACH OR EXCEED
60...ABOUT 20 DEGREES ABOVE NORMAL. DRY AIR IN PLACE WILL PREVENT
ANY PRECIPITATION WITH THE WARM ADVECTION...AND PERHAPS CLOUDS TOO.
AS WE HEAD INTO THANKSGIVING AND THROUGH FRIDAY NIGHT...THE 17.00Z
CANADIAN/ECMWF/GFS AND GFS ENSEMBLES ALL POINT TO THE POTENT
SHORTWAVE DIGGING SOUTHEAST THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DIFFERENT FROM THE 16.12Z ECMWF AND 16.00Z
GFS WHICH HAD MORE OF A FLATTER...ZONAL FLOW. THUS...WE WILL SEE IF
THIS IDEA OF THE SHORTWAVE DIGGING INTO THE AREA CONTINUES WITH
LATER RUNS. NOTE THAT THE 17.00Z GFS ENSEMBLES ARE ALL OVER THE
PLACE WITH THIS FEATURE. IN ANY EVENT...RIGHT NOW THERE IS GOOD
AGREEMENT ON IT OCCURRING FROM THE DETERMINISTIC MODELS...BUT TIMING
VARIES FROM THANKSGIVING DAY TO FRIDAY. FOR NOW HAVE STUCK WITH A
CONSENSUS APPROACH WHICH BRINGS THE POTENT TROUGH IN THANKSGIVING
DAY NIGHT. THUS...THANKSGIVING STILL LOOKS WARM AHEAD OF A COLD
FRONT MOVING IN. HIGHS MOST LOCATIONS SHOULD END UP IN THE 50S.
COOLER CONDITIONS ARE LIKELY ON FRIDAY IN THE WAKE OF THE COLD FRONT
AS 850MB TEMPS PLUMMET DOWN TO AT OR BELOW 0C BY 00Z SATURDAY.
REGARDING THE COLD FRONTAL PASSAGE FOR PRECIPITATION...RIGHT NOW IT
APPEARS STILL THAT THE AIRMASS IS TOO DRY BOTH BEHIND AND AHEAD OF
THE FRONT TO ALLOW FOR ANYTHING TO OCCUR. ANY PRECIPITATION SHOULD
STAY TO THE NORTH...CLOSER TO THE BETTER DYNAMICS...AND TO THE
SOUTHEAST WHERE A LONGER PERIOD OF MOISTURE RETURN CAN OCCUR.
&&
.AVIATION...
1030 PM CST FRI NOV 16 2012
LOW LEVEL MOISTURE REMAINS TRAPPED UNDER AN INVERSION OVER PARTS OF
CENTRAL/EASTERN WI LATE THIS EVENING...WITH HIGH PRESSURE CENTERED
OVERHEAD. RAP13/NAM12 SUGGEST EXPANSION OF A FOG/STRATUS LAYER
TONIGHT AS A RESULT....AND LATEST SATELLITE IMAGERY DEPICTS
THIS...BUT KEEPS IT ACROSS NORTHEAST WI. DON/T EXPECT AN IMPACT AT
KLSE.
THE HIGH WILL MOVE OFF TO THE EAST ON SATURDAY...LEADING TO A
TIGHTENING PRESSURE GRADIENT ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY. WINDS WILL INCREASE AS A RESULT...WITH AFTERNOON MIXING
RESULTING IN SOME GUSTINESS. WINDS LOOK SIMILAR FOR SUNDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST SAT NOV 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS FLAGSTAFF AZ
410 AM MST SAT NOV 17 2012
.SYNOPSIS...INCREASING CLOUDS WILL LEAD TO SCATTERED SHOWERS LATER
TODAY...LASTING INTO THIS EVENING. THE BEST CHANCE FOR SHOWERS WILL
BE THROUGH EASTERN YAVAPAI COUNTY AND NORTHWARD INTO COCONINO COUNTY
THIS AFTERNOON...MOVING TOWARD THE FOUR CORNERS BY THIS EVENING.
COOLER...BUT DRIER CONDITIONS WILL DEVELOP SUNDAY...WITH A WARMING
TREND AND CONTINUED DRY CONDITIONS INTO NEXT WEEK.
&&
.DISCUSSION...A PRONOUNCED SUB-TROPICAL JET STREAK WILL MOVE INTO
CENTRAL ARIZONA TODAY...AHEAD OF A WEAK S/WV NOW ENTERING SOUTHERN
CALIFORNIA. LOW AND MIDDLE CLOUDS OVER WESTERN ARIZONA INDICATE THAT
LIFT AND MOISTURE LEVELS MAY BE A LITTLE BETTER THAN MODELS ARE
FORECASTING THIS MORNING. THIS MOISTURE WILL BE AIDED BY IMPROVING
DYNAMICS THIS AFTERNOON AS HGHTS FALL AND THE JET STREAK PLACES
CENTRAL AND NORTHERN ARIZONA UNDER MORE FAVORABLE DYNAMICS. THE
RAP13 AND HRRR MODELS SEEM TO BE HANDLING THIS SCENARIO BEST AS BOTH
MODELS GENERATE SHOWERS IN CENTRAL ARIZONA BY THE EARLY AFTERNOON.
THEN...THE BEST FORCING SHIFTS NORTH AND EAST...TOWARD THE FOUR
CORNERS INTO THE EARLY EVENING. DRIER AIR AND SUBSIDENCE WILL TRAIL
THIS WAVE LATER TONIGHT INTO SUNDAY...DESPITE A COLDER AIRMASS
ALOFT. EXPECT POPS TO END BY LATER SUNDAY...WITH WARMING AND DRY
CONDITIONS EXPECTED FOR MUCH OF NEXT WEEK AS RIDGING REDEVELOPS.
&&
.AVIATION....AVIATION...FOR THE 12Z PACKAGE...VFR AND ISOLATED MVFR
CONDITIONS ARE EXPECTED. SCT-BKN CLOUDS ARE FORECAST WITH A FEW
LIGHT SHOWERS TODAY AND TONIGHT...MAINLY OVER THE HIGHER ELEVATIONS.
AVIATION SECTION NOT UPDATED FOR AMENDMENTS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........PETERSON
AVIATION.......BOHLIN
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1040 AM EST SAT NOV 17 2012
.DISCUSSION...
MID LEVEL REX BLOCKING PATTERN EXTENDING FROM THE GREAT LAKES TO THE
ERN GOMEX THIS MORNING. CUT-OFF H85-H50 LOW OVER THE DEEP SOUTH/ERN
GOMEX WILL REMAIN NEARLY STATIONARY THIS AFTN...KEEPING THE FL
PENINSULA ON ITS ASCENDING ERN FLANK. IN THE H100-H70 LYR...A LARGE
ANTICYCLONE EXTENDING FROM THE ST. LAWRENCE SEAWAY TO THE RIO GRANDE
VALLEY WILL COMBINE WITH AN INVERTED TROF E OF THE FL PENINSULA TO
GENERATE A STEADY NE BREEZE ACRS CENTRAL FL.
MORNING SOUNDINGS SHOW MODEST PWATS OF 1.1"-1.3" ACRS CENTRAL/S
FL...DECREASING TO 0.9" AT KJAX...NEARLY SATURATED THRU THE H100-H75
LYR. KXMR HAD A LOW LVL DRY SLUG...CONFIRMED BY LATEST RAP RH
ANALYSIS THRU THE H100-H70 LYR. KTBW/KXMR TEMP TREND OVER THE PAST
24HRS REVEALS MODERATE CAA ABV H80...WEAK WAA BLO H80...CONVECTIVE
TRIGGER TEMP ARND 80F AT KXMR.
THE LATTER MAY BE DIFFICULT TO REACH GIVEN THE DEEP E/NE FLOW.
HOWEVER...GIVEN THE POSITION OF THE MID LVL TROF OVER THE GOMEX...
MID/UPR LVL DYNAMIC SUPPORT MAY BE JUST STRONG ENOUGH TO COMPENSATE
FOR THE LACK OF SFC HEATING. INDEED...ISENTROPIC ANALYSIS SHOWS
STRONG LIFT OCCURRING ACRS THE NRN/WRN PENINSULA...WEAK TO MODERATE
OVER THE SRN PENINSULA. THIS MATCHES UP WELL WITH THE CURRENT POP
CONFIGURATION. MORNING UPDATES MAINLY TO REFRESH THE TEXT...NO
SUBSTANTIVE CHANGES NECESSARY.
&&
.AVIATION...
VFR ALL SITES UNLESS OTHERWISE NOTED. BTWN 17/18Z-17/24Z...SCT MVFR
SHRAS/ISOLD IFR TSRAS...MAINLY N OF KVRB/KISM. BTWN 18/00Z-18/03Z...
SHRA/TSRAS ENDING INTERIOR SITES...CONTG THRU 18/12Z COASTAL SITES N
OF KMLB.
&&
.MARINE...
LATEST OBS FROM BUOY SHOWING FULL BLOWN SCA WINDS/SEAS...
DIMINISHING TO SCA SEAS AT BUOY...NEARSHORE SCRIPPS BUOYS
MEASURING SEAS IN THE 4-6FT RANGE. INVERTED TROF JUST E OF THE LCL
ATLC WILL GENERATE A MODERATE TO FRESH NE BREEZE N OF SEBASTIAN
INLET...GENTLE TO MODERATE S OF THE INLET. CURRENT SCA CONFIGURATION
LOOKS GOOD...NO SIG CHANGES NECESSARY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 10 PM EST SUNDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM-WATERS FROM FLAGLER BEACH TO
VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS
FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO
60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...GLITTO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
420 AM MST SAT NOV 17 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
05Z WATER VAPOR IMAGERY RUC ANALYSIS INDICATED RIDGE AXIS IN PLACE
ACROSS THE MISSOURI VALLEY WITH STRONG SHORT WAVE TROUGH NEARING THE
PAC NORTHWEST. 00Z SOUNDINGS INDICATED A FAIRLY LARGE DIFFERENCE IN
THE LARGE SCALE AIR MASS BETWEEN DNR AND LBF/DDC. AT
LBF/DDC...STRONG INVERSION WAS NOTED BETWEEN H8 AND H7 MAKING
OVERALL AIR MASS VERY STABLE. IN ADDITION TO THE STABLE
LAYER...MIXING RATIOS INDICATED A FAIRLY DEEP MOIST LAYER ENDING
AROUND H8. AT DNR...NEARLY DRY ADIABATIC LAPSE RATES NOTED BETWEEN
H75 AND H55 WITH MIXING RATIOS DROPPING RAPIDLY ABOVE THE SFC LAYER.
AT THE SFC...TROUGH AXIS WAS LOCATED ACROSS EASTERN COLORADO.
TODAY-TOMORROW...SEVERAL WEAK/LOW AMPLITUDE SHORT WAVE TROUGHS WILL
MOVE ACROSS THE REGION THROUGH THE PERIOD EACH BRINGING A BRIEF
PERIOD OF FORCED ASCENT ACROSS THE CWA. FOR THE MOST PART...SEEMS
UNLIKELY THAT LIFT WELL BE ABLE TO SATURATE AND NEAR SFC OR MID
LEVEL LAYERS THROUGH TONIGHT AND WHILE ELEVATED THETA E LAPSE RATES
SUPPORT THE POSSIBILITY OF POTENTIAL INSTABILITY...THINK VERTICAL
MOISTURE PROFILES MAKE THIS VERY UNLIKELY. MODELS DIVERGE A BIT MORE
ON SUNDAY WITH HANDLING OF NEXT TROUGH WHICH WILL PROVIDE NOTICEABLY
STRONGER FORCING AS IT MORE DIRECTLY MOVES OVER CWA. MAJORITY OF
MODELS AND GEFS ENSEMBLES SUPPORT PRECIPITATION THREAT ACROSS
EASTERN KANSAS...WHILE NAM AND SREF SUGGESTING POCKET OF ELEVATED
CAPE WILL DEVELOP ACROSS SOUTHEASTERN CWA AS TROUGH PASSES. BASED ON
MODEL CONSENSUS WILL WEIGHT FORECAST MORE TOWARDS THE EASTERN KS
SOLUTIONS...BUT DID UP POPS TO AROUND 10 PERCENT IN THE EAST SINCE
LAPSE RATES WOULD SUPPORT INSTABILITY DEVELOPMENT SHOULD ANY
MEANINGFUL MOISTURE ADVECTION OCCUR. THE OTHER POTENTIAL FOR SENSIBLE
WEATHER WILL BE THE THREAT OF FOG/STRATUS EARLY THIS MORNING AND
AGAIN SUNDAY MORNING. WITH WINDS STAYING IN THE 5 TO 10 KT RANGE
AHEAD OF SFC TROUGH...NOT REALLY CONFIDENT IN FOG FORMATION. HOWEVER
BASED ON OBSERVED SOUNDINGS SHOWING A FAIRLY DEEP NEAR SFC MOIST
LAYER...WILL LEAVE A PATCHY MENTION IN AREAS MOST LIKELY TO DECOUPLE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
SUNDAY NIGHT-MONDAY NIGHT...ZONAL FLOW ALOFT WILL GRADUALLY SHIFT
TO SHORT WAVE RIDGING TOWARDS THE END OF THE PERIOD...WITH DRY AND
OVERALL QUIET CONDITIONS EXPECTED TO CONTINUE. TEMPERATURES WILL
GRADUALLY WARM THROUGH THE PERIOD...WITH A FEW LOCATIONS NEARING
70 BY MONDAY.
TUESDAY-FRIDAY...
PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK WELL NORTH OF CWA
ALONG CANADIAN BORDER AND WEAKER SOUTHERN TRACK ACROSS SOUTHERN
PLAINS IS EXPECTED THROUGH THE EXTENDED PERIOD. RESULT OF THIS
PATTERN WILL BE ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
PERSISTING OVER THE CWA. A SHORTWAVE RIDGE BEGINS TO BUILD INTO THE
INTER-MOUNTAIN WEST TUESDAY AND THEN ACROSS THE PLAINS ON
WEDNESDAY...WHEN HIGH TEMPS IN THE UPPER 60S/NEAR 70 ARE EXPECTED.
RH VALUES ON WEDNESDAY COULD APPROACH CRITICAL LEVELS...HOWEVER
WINDS SHOULD REMAIN WELL BELOW RED FLAG CRITERIA. WHILE THERE WILL
BE A SLIGHTLY COOLER AIR MASS BEHIND A WEAK COLD FRONT WE SHOULD
STILL SEE ABOVE NORMAL TEMPS THURSDAY AND FRIDAY WITH HIGHS IN THE
UPPER 50S/LOW 60S AND LOWS IN THE 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 411 AM MST SAT NOV 17 2012
MAIN FORECAST CONCERN FOR THE PERIOD WILL BE FOG POTENTIAL THIS
MORNING AND TOMORROW MORNING...ESPECIALLY AT MCK. 00Z SOUNDINGS
INDICATED A DEEP NEAR SFC MOIST LAYER IN PLACE ACROSS THE AREA AND
WITH WINDS DECOUPLING...SKIES CLEARING AND COOLER AIR WORKING ITS
WAY DOWN THE REPUBLICAN RIVER VALLEY...A PERIOD OF REDUCED FLIGHT
CATEGORIES POSSIBLE. NOT INCREDIBLY CONFIDENT IN VISIBILITY
REDUCTIONS...BUT THINK INCLUDING AN OPERATIONALLY SIGNIFICANT
CATEGORY APPROPRIATE. SIMILAR SET UP TOMORROW NIGHT WITH PERIOD OF
LIGHT WINDS AND MOSTLY CLEAR SKIES ALONG THE KANSAS AND NEBRASKA
BORDER. WITH NO AIR MASS CHANGE EXPECTED...THINK FOG POTENTIAL
WILL INCREASE IN SIMILAR AREA AFTER 09Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...JRM
AREA FORECAST DISCUSSION...UPDATED
NWS SPOKANE WA
741 AM PST Sat Nov 17 2012
.SYNOPSIS...
Today through next week expect a progressive and wet weather
pattern to return with periods of mountain snow and valley rain
this weekend and through next week. Higher snow levels Sunday
Night through Tuesday morning will combine with the heaviest
expected precipitation in this forecast cycle to produce rises on
the areas small stream or creeks...especially for North Idaho.
&&
.DISCUSSION...Based on radar and latest HRRR (Rapid Refresh)model
runs showing substantial precipitation activity drifting northeast
through the forecast area have increased pops with update. HRRR
does hint at a lull in KGEG vicinity as that area is between area
of rain exiting to the northeast and has a few hours before a
second larger and more intense area of rain approaching in similar
fashion from the southwest is overhead near 00Z but I`m not sure I
can get grid forecast timing to depict this well so will just
leave the rather high pops in place for the remainder of today. /Pelatti
&&
.AVIATION...
06Z TAFs: The air mass over the region will become increasingly
moist at all levels this morning...with light rain beginning by
18z at KEAT and KMWH...spreading eastward to encompass the KGEG
area TAF sites buy 21Z. This will be mainly light isentropic rain
with ceilings predominantly VFR or occasional MVFR. Exception will
be KEAT where stubborn low level IFR stratus will be slow to erode
as precipitation begins. A strong cold front along the Cascade
Crest at 00Z will move to the Idaho Panhandle by 12Z Sunday.
Along this front dense shower coverage with MVFR ceilings and vis
are expected at all TAF sites immediately ahead of and along the
front. /MJF
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 37 45 38 42 40 / 70 100 50 100 100 100
Coeur d`Alene 48 37 45 36 42 40 / 70 100 50 90 100 100
Pullman 52 37 47 38 44 42 / 50 100 40 80 100 100
Lewiston 53 40 53 42 50 45 / 30 100 40 60 80 90
Colville 45 37 43 38 41 38 / 80 100 50 100 100 100
Sandpoint 47 37 44 35 41 38 / 70 100 80 90 100 100
Kellogg 48 37 41 34 39 39 / 60 100 80 60 100 100
Moses Lake 46 36 47 39 47 40 / 60 80 10 60 80 70
Wenatchee 42 37 45 38 44 39 / 60 60 20 90 80 70
Omak 42 35 42 37 42 39 / 90 100 30 100 100 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
551 AM CST SAT NOV 17 2012
.SHORT TERM...THROUGH MONDAY NIGHT
200 AM CST SAT NOV 17 2012
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES SUNDAY NIGHT INTO MONDAY
NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OFF BRITISH COLUMBIA...SUBTROPICAL RIDGING FROM
NORTHERN MEXICO TO LAKE ERIE...AND SHORTWAVES RIDING IN THE
SOUTHWEST SUBTROPICAL FLOW JUST OFF THE CALIFORNIA COAST AND NEAR
THE WY/SOUTH DAKOTA BORDER. THIS LATTER SHORTWAVE WAS PRODUCING A
MASS OF CIRRUS ACROSS THE DAKOTAS INTO NORTHWEST MINNESOTA. DRY LOW
TO MID LEVELS SEEN ON THE 00Z MPX...ABR AND UNR SOUNDINGS HAS
PREVENTED ANY LOWER CLOUD DEVELOPMENT. REGARDING THE DRYNESS...BOTH
MPX AND ABR SOUNDINGS ONLY HAD PRECIPITABLE WATER VALUES OF 0.20
INCHES. FARTHER TO THE EAST...AN AREA OF LOW STRATUS WAS PRESENT
ACROSS MUCH OF GRBS FORECAST AREA INTO LOCATIONS ALONG/NORTHEAST OF
I-94 IN OUR AREA. THIS STRATUS FORMED FROM SOUTHEAST ADVECTION OF
MOISTURE OFF LAKE MICHIGAN UNDERNEATH A SUBSIDENCE INVERSION...
COMBINED WITH LIGHT WINDS AND CLEAR SKIES EARLIER IN THE EVENING. A
STRONGER SOUTH FLOW ON THE BACK SIDE OF HIGH PRESSURE OVER LOWER
MICHIGAN HAS HELPED KEEP THE REST OF THE AREA LOW CLOUD FREE. THIS
FLOW...WHICH STRENGTHENS HEADING WEST TOWARDS THE DAKOTAS...HAS BEEN
BRINGING WARMER AIR INTO THE REGION. RAP ANALYSIS SHOWED 925MB TEMPS
OF 7C AT MPX COMPARED TO 2C ON THE 00Z SOUNDING. SURFACE
TEMPERATURES HAVE REFLECTED THE WARM ADVECTION WITH READINGS FROM
THE MID 20S TO MID 30S...WARMEST WEST OF THE MISSISSIPPI RIVER.
TODAY AND TONIGHT...THE SHORTWAVE ALONG THE WYOMING/SOUTH DAKOTA
BORDER IS PROGGED TO LIFT INTO NORTHERN MINNESOTA TONIGHT. THE TRACK
IS SLIGHTLY FARTHER NORTH THAN 24 HOURS AGO. WITH THE FARTHER NORTH
TRACK...THERE SHOULD BE A LITTLE LESS CLOUDS. SOME OF THE CIRRUS
STILL LOOKS SLATED TO CROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...WITH SOME ALTOSTRATUS PRODUCED BY ISENTROPIC
LIFT AFTER MIDNIGHT. PLENTY OF LOW LEVEL DRY AIR WILL RESULT IN A
CONTINUATION OF THE DRY FORECAST. ONLY OTHER CLOUD COVER OF NOTE IS
THE EARLY MORNING STRATUS OVER THE NORTHEAST PORTION OF THE FORECAST
AREA...WHICH SHOULD SHIFT NORTHEAST DURING THE MORNING WITH THE
INCREASING SOUTH TO SOUTHWEST 950-925MB FLOW. THIS FLOW IS PROGGED
TO REACH 25-30KT TODAY AS THE GRADIENT TIGHTENS. WITH PLENTY OF
SUN...EXPECT BREEZY CONDITIONS...PARTICULARLY ON THE HIGHER TERRAIN
WEST OF THE MISSISSIPPI RIVER WHICH IS MORE EXPOSED AND IN THE
TIGHTEST GRADIENT. THE BREEZE SHOULD PERSIST INTO TONIGHT WITH THE
STRENGTHENING OF THE LOW LEVEL JET...NOTED TOO BY 950-925MB WINDS
INCREASING TO 30-45KT. THESE WINDS WILL CONTINUE TO BRING WARMER AIR
INTO THE REGION WITH 925MB TEMPS INDICATED BETWEEN 4-6C AT 18Z.
THESE SUPPORT HIGHS IN THE LOW TO MID 50S. FOLLOWED A BLEND OF
GUIDANCE FOR LOWS TONIGHT WITH THE BREEZE AND PASSING CLOUDS HELPING
TO PRODUCE A WARMER NIGHT.
SUNDAY INTO SUNDAY NIGHT...ATTENTION FOCUSES TO THE SHORTWAVE OFF
THE CALIFORNIA COAST. GOOD MODEL AGREEMENT EXISTS THAT THIS
SHORTWAVE WILL LIFT INTO THE CENTRAL PLAINS BY LATE SUNDAY...THEN
INTO WESTERN PORTIONS OF MINNESOTA AND IOWA BY 12Z MONDAY. RIDGING
LOOKS TO DEVELOP OVER THE FORECAST AREA FOR A TIME AHEAD OF THIS
SHORTWAVE AND IN THE WAKE OF THE SHORTWAVE LIFTING OUT OF NORTHERN
MINNESOTA. SUBSIDENCE UNDER THE RIDGE SHOULD THIN CLOUDS OUT SOME
FOR MUCH OF THE DAY UNTIL LATE. THIS IS WHEN THE AREA BEGINS TO FEEL
THE MOISTURE ADVECTION EFFECTS AHEAD OF THE SHORTWAVE...WHICH WILL
START PRODUCING AN ALTOSTRATUS DECK IN THE EVENING ACROSS THE AREA.
FURTHER LOWERING OF CEILINGS WILL OCCUR THROUGH THE NIGHT AS
PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.5 INCH AT 00Z TO NEAR
0.75 INCHES AT 12Z MONDAY. ALTHOUGH MOISTURE INCREASES...THE
ISENTROPIC LIFT IS QUITE WEAK...FOCUSED MAINLY WEST OF A LINE FROM
MEDFORD TO LA CROSSE AND OELWEIN BETWEEN 06-12Z. HAVE MAINTAINED A
20-30 PERCENT CHANCE FOR THIS AREA AND TIME PERIOD...BUT GIVEN THE
WEAK LIFT SIGNATURE IT IS POSSIBLE ANY PRECIPITATION HOLDS OFF UNTIL
AFTER 12Z MONDAY AS SUGGESTED BY THE 17.00Z GFS/NAM. 17.00Z ECMWF IS
MORE ROBUST...THOUGH. WARMER 925MB TEMPS IN THE 5-7C RANGE AT 18Z
SUNDAY PLUS THE SOUTHERLY BREEZE AND SUN SHOULD YIELD HIGHS IN THE
MID TO UPPER 50S. A FEW LOCATIONS MAY REACH OR EXCEED 60...
ESPECIALLY IF MORE SUN OCCURS. EVEN A WARMER NIGHT SHOULD OCCUR
SUNDAY NIGHT WITH MORE MOISTURE...CLOUDS AND THE BREEZE. LOWS WEST
OF THE MISSISSIPPI RIVER MAY NOT DIP BELOW 40.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE TROUGH OVER THE PLAINS
MODELS AGREE ON BRINGING IT ACROSS THE FORECAST AREA MONDAY EVENING.
AS THE TROUGH APPROACHES MONDAY...THE ISENTROPIC LIFT LOOKS TO
INCREASE A LITTLE...ENOUGH TO WARRANT PRECIPITATION CHANCES AS HIGH
AS 40 PERCENT. KEPT THESE CHANCES LOW BECAUSE BOTH THE 17.00Z GFS
AND NAM SHOW A DRY LOOK TO THEIR QPF FIELDS. THE ECMWF REMAINS THE
MOST ROBUST...THOUGH ITS LATEST 17.00Z RUN HAS A SLIGHTLY DRIER LOOK
THAN ITS PREVIOUS 16.12Z RUN. MUCH OF THE RAIN...IF IT OCCURS...
SHOULD BE EAST OF THE AREA BY 00Z. HOWEVER...HAVE MAINTAINED A 20
PERCENT CHANCE OVER FAR EASTERN AREAS FROM 00-06Z SINCE THERE IS
STILL WEAK ISENTROPIC LIFT INDICATED ON THE 290-295K SURFACES.
PLENTY OF CLOUDS ON MONDAY WILL PREVENT TEMPERATURES FROM RISING AS
MUCH COMPARED TO THE WEEKEND. HAVE FOLLOWED A BLEND OF GUIDANCE FOR
HIGHS. CLOUDS GRADUALLY CLEARING OUT WEST TO EAST MONDAY NIGHT PLUS
LIGHTER WINDS RESULTING FROM A WEAKER PRESSURE GRADIENT SHOULD ALLOW
TEMPERATURES TO DIP INTO THE 30S TO AROUND 40 AT MOST LOCATIONS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
200 AM CST SAT NOV 17 2012
THE MAIN ISSUE IN THE LONG TERM FORECAST IS A VERY POTENT SHORTWAVE
COMING OUT OF THE NORTHEAST PACIFIC TROUGH AND ENTERING THE PACIFIC
NORTHWEST TUESDAY EVENING. ALL MODELS AGREE ON UPPER RIDGING
BUILDING AHEAD OF THE POTENT SHORTWAVE INTO THE FORECAST AREA
TUESDAY NIGHT...RESULTING IN A SURGE OF WARM AIR ADVECTING INTO THE
AREA. 925MB TEMPS CLIMB FROM AROUND 6C AT 18Z TUESDAY TO 10-12C AT
18Z WEDNESDAY. 850MB TEMP ANOMALIES ON WEDNESDAY ARE 1.5 STANDARD
DEVIATIONS ABOVE NORMAL. PLENTY OF SUN LOOKS TO OCCUR AT LEAST ON
WEDNESDAY...AND PERHAPS TUESDAY TOO DEPENDING ON WHEN LOW CLOUDS
CLEAR ASSOCIATED WITH THE MONDAY/MONDAY NIGHT SHORTWAVE.
THEREFORE...THERE SHOULD BE DECENT MIXING DESPITE THE SHORTER DAY
LENGTH. HAVE LEANED ON THE WARM SIDE OF GUIDANCE AS A RESULT...
ESPECIALLY WEDNESDAY WHEN HIGHER CONFIDENCE EXISTS OF FULL SUN AND A
SOUTHERLY BREEZE IS PRESENT. HIGHS WEDNESDAY COULD REACH OR EXCEED
60...ABOUT 20 DEGREES ABOVE NORMAL. DRY AIR IN PLACE WILL PREVENT
ANY PRECIPITATION WITH THE WARM ADVECTION...AND PERHAPS CLOUDS TOO.
AS WE HEAD INTO THANKSGIVING AND THROUGH FRIDAY NIGHT...THE 17.00Z
CANADIAN/ECMWF/GFS AND GFS ENSEMBLES ALL POINT TO THE POTENT
SHORTWAVE DIGGING SOUTHEAST THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DIFFERENT FROM THE 16.12Z ECMWF AND 16.00Z
GFS WHICH HAD MORE OF A FLATTER...ZONAL FLOW. THUS...WE WILL SEE IF
THIS IDEA OF THE SHORTWAVE DIGGING INTO THE AREA CONTINUES WITH
LATER RUNS. NOTE THAT THE 17.00Z GFS ENSEMBLES ARE ALL OVER THE
PLACE WITH THIS FEATURE. IN ANY EVENT...RIGHT NOW THERE IS GOOD
AGREEMENT ON IT OCCURRING FROM THE DETERMINISTIC MODELS...BUT TIMING
VARIES FROM THANKSGIVING DAY TO FRIDAY. FOR NOW HAVE STUCK WITH A
CONSENSUS APPROACH WHICH BRINGS THE POTENT TROUGH IN THANKSGIVING
DAY NIGHT. THUS...THANKSGIVING STILL LOOKS WARM AHEAD OF A COLD
FRONT MOVING IN. HIGHS MOST LOCATIONS SHOULD END UP IN THE 50S.
COOLER CONDITIONS ARE LIKELY ON FRIDAY IN THE WAKE OF THE COLD FRONT
AS 850MB TEMPS PLUMMET DOWN TO AT OR BELOW 0C BY 00Z SATURDAY.
REGARDING THE COLD FRONTAL PASSAGE FOR PRECIPITATION...RIGHT NOW IT
APPEARS STILL THAT THE AIRMASS IS TOO DRY BOTH BEHIND AND AHEAD OF
THE FRONT TO ALLOW FOR ANYTHING TO OCCUR. ANY PRECIPITATION SHOULD
STAY TO THE NORTH...CLOSER TO THE BETTER DYNAMICS...AND TO THE
SOUTHEAST WHERE A LONGER PERIOD OF MOISTURE RETURN CAN OCCUR.
&&
.AVIATION...TODAY AND TONIGHT
540 AM CST SAT NOV 17 2012
THE COMBINATION OF LIGHT WINDS AND MOSTLY CLEAR SKIES ALLOWED
AREAS OF MVFR FOG TO DEVELOP ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY OVERNIGHT. THE FOG WAS LOCALLY DENSE IN THE WISCONSIN AND
KICKAPOO RIVER VALLEYS AND IN CENTRAL WISCONSIN. THE SURFACE
PRESSURE GRADIENT IS EXPECTED TO TIGHTEN UP BETWEEN 17.12Z AND
17.14Z. AS THIS OCCURS...THE FOG WILL QUICKLY DISSIPATE.
FOR THE REMAINDER OF THE TODAY...SKIES WILL BE MAINLY CLEAR...AND
THEN THE MID AND HIGH CLOUDS WILL INCREASE TONIGHT AS A LOW
PRESSURE SYSTEM MOVES THROUGH NORTHERN MINNESOTA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST SAT NOV 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS FLAGSTAFF AZ
915 AM MST SAT NOV 17 2012
.SYNOPSIS...INCREASING CLOUDS WILL LEAD TO SCATTERED SHOWERS THIS
AFTERNOON AND EVENING. THE BEST CHANCE FOR SHOWERS WILL BE
THROUGH EASTERN YAVAPAI COUNTY NORTHWARD INTO COCONINO COUNTY THIS
AFTERNOON...MOVING TOWARDS THE FOUR CORNERS THIS EVENING. COOLER AND
DRIER CONDITIONS WILL RETURN SUNDAY...THEN A WARMING TREND THROUGH
NEXT WEEK.
&&
.DISCUSSION...
SATELLITE IMAGERY INDICATES DENSE MID AND HIGH LEVEL CLOUD COVER
SOUTH OF A LINE FROM CHAMBERS THROUGH PAYSON TO YUMA THIS MORNING.
TODAYS SKY COVER GRIDS WERE INCREASED TO MATCH THIS FEATURE.
WE MAY BE INCREASING SHOWER CHANCES TONIGHT NORTH OF INTERSTATE 40
AS THIS IS WHEN THE CALIFORNIA SHORTWAVE MENTION BELOW CROSSES OUR
AREA. STILL EXPECTING ONLY LIGHT PRECIP AMOUNTS.
&&
.PREV DISCUSSION 410 AM...A PRONOUNCED SUB-TROPICAL JET STREAK WILL
MOVE INTO CENTRAL ARIZONA TODAY...AHEAD OF A WEAK S/WV NOW ENTERING
SOUTHERN CALIFORNIA. LOW AND MIDDLE CLOUDS OVER WESTERN ARIZONA
INDICATE THAT LIFT AND MOISTURE LEVELS MAY BE A LITTLE BETTER THAN
MODELS ARE FORECASTING THIS MORNING. THIS MOISTURE WILL BE AIDED BY
IMPROVING DYNAMICS THIS AFTERNOON AS HGHTS FALL AND THE JET STREAK
PLACES CENTRAL AND NORTHERN ARIZONA UNDER MORE FAVORABLE DYNAMICS.
THE RAP13 AND HRRR MODELS SEEM TO BE HANDLING THIS SCENARIO BEST AS
BOTH MODELS GENERATE SHOWERS IN CENTRAL ARIZONA BY THE EARLY
AFTERNOON. THEN...THE BEST FORCING SHIFTS NORTH AND EAST...TOWARD
THE FOUR CORNERS INTO THE EARLY EVENING. DRIER AIR AND SUBSIDENCE
WILL TRAIL THIS WAVE LATER TONIGHT INTO SUNDAY...DESPITE A COLDER
AIRMASS ALOFT. EXPECT POPS TO END BY LATER SUNDAY...WITH WARMING AND
DRY CONDITIONS EXPECTED FOR MUCH OF NEXT WEEK AS RIDGING REDEVELOPS.
&&
..AVIATION...FOR THE 18Z PACKAGE...A WEAK WEATHER DISTURBANCE WILL
BRUSH NORTHERN ARIZONA TODAY AND TONIGHT. THE MAIN IMPACT WILL BE
ISOLATED CEILINGS OF 2-4 KFT AGL OVER THE MOUNTAINS. OTHERWISE...
VFR CONDITIONS WILL PREVAIL UNDER SCATTERED TO BROKEN SKY CONDITIONS
AND A FEW LIGHT SHOWERS. AVIATION SECTION NOT UPDATED FOR AMENDMENTS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........DL / PETERSON
AVIATION.......MCCOLLUM
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1006 AM MST SAT NOV 17 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
05Z WATER VAPOR IMAGERY RUC ANALYSIS INDICATED RIDGE AXIS IN PLACE
ACROSS THE MISSOURI VALLEY WITH STRONG SHORT WAVE TROUGH NEARING THE
PAC NORTHWEST. 00Z SOUNDINGS INDICATED A FAIRLY LARGE DIFFERENCE IN
THE LARGE SCALE AIR MASS BETWEEN DNR AND LBF/DDC. AT
LBF/DDC...STRONG INVERSION WAS NOTED BETWEEN H8 AND H7 MAKING
OVERALL AIR MASS VERY STABLE. IN ADDITION TO THE STABLE
LAYER...MIXING RATIOS INDICATED A FAIRLY DEEP MOIST LAYER ENDING
AROUND H8. AT DNR...NEARLY DRY ADIABATIC LAPSE RATES NOTED BETWEEN
H75 AND H55 WITH MIXING RATIOS DROPPING RAPIDLY ABOVE THE SFC LAYER.
AT THE SFC...TROUGH AXIS WAS LOCATED ACROSS EASTERN COLORADO.
TODAY-TOMORROW...SEVERAL WEAK/LOW AMPLITUDE SHORT WAVE TROUGHS WILL
MOVE ACROSS THE REGION THROUGH THE PERIOD EACH BRINGING A BRIEF
PERIOD OF FORCED ASCENT ACROSS THE CWA. FOR THE MOST PART...SEEMS
UNLIKELY THAT LIFT WELL BE ABLE TO SATURATE AND NEAR SFC OR MID
LEVEL LAYERS THROUGH TONIGHT AND WHILE ELEVATED THETA E LAPSE RATES
SUPPORT THE POSSIBILITY OF POTENTIAL INSTABILITY...THINK VERTICAL
MOISTURE PROFILES MAKE THIS VERY UNLIKELY. MODELS DIVERGE A BIT MORE
ON SUNDAY WITH HANDLING OF NEXT TROUGH WHICH WILL PROVIDE NOTICEABLY
STRONGER FORCING AS IT MORE DIRECTLY MOVES OVER CWA. MAJORITY OF
MODELS AND GEFS ENSEMBLES SUPPORT PRECIPITATION THREAT ACROSS
EASTERN KANSAS...WHILE NAM AND SREF SUGGESTING POCKET OF ELEVATED
CAPE WILL DEVELOP ACROSS SOUTHEASTERN CWA AS TROUGH PASSES. BASED ON
MODEL CONSENSUS WILL WEIGHT FORECAST MORE TOWARDS THE EASTERN KS
SOLUTIONS...BUT DID UP POPS TO AROUND 10 PERCENT IN THE EAST SINCE
LAPSE RATES WOULD SUPPORT INSTABILITY DEVELOPMENT SHOULD ANY
MEANINGFUL MOISTURE ADVECTION OCCUR. THE OTHER POTENTIAL FOR SENSIBLE
WEATHER WILL BE THE THREAT OF FOG/STRATUS EARLY THIS MORNING AND
AGAIN SUNDAY MORNING. WITH WINDS STAYING IN THE 5 TO 10 KT RANGE
AHEAD OF SFC TROUGH...NOT REALLY CONFIDENT IN FOG FORMATION. HOWEVER
BASED ON OBSERVED SOUNDINGS SHOWING A FAIRLY DEEP NEAR SFC MOIST
LAYER...WILL LEAVE A PATCHY MENTION IN AREAS MOST LIKELY TO DECOUPLE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 151 AM MST SAT NOV 17 2012
SUNDAY NIGHT-MONDAY NIGHT...ZONAL FLOW ALOFT WILL GRADUALLY SHIFT
TO SHORT WAVE RIDGING TOWARDS THE END OF THE PERIOD...WITH DRY AND
OVERALL QUIET CONDITIONS EXPECTED TO CONTINUE. TEMPERATURES WILL
GRADUALLY WARM THROUGH THE PERIOD...WITH A FEW LOCATIONS NEARING
70 BY MONDAY.
TUESDAY-FRIDAY...
PROGRESSIVE ZONAL PATTERN WITH MAIN STORM TRACK WELL NORTH OF CWA
ALONG CANADIAN BORDER AND WEAKER SOUTHERN TRACK ACROSS SOUTHERN
PLAINS IS EXPECTED THROUGH THE EXTENDED PERIOD. RESULT OF THIS
PATTERN WILL BE ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS
PERSISTING OVER THE CWA. A SHORTWAVE RIDGE BEGINS TO BUILD INTO THE
INTER-MOUNTAIN WEST TUESDAY AND THEN ACROSS THE PLAINS ON
WEDNESDAY...WHEN HIGH TEMPS IN THE UPPER 60S/NEAR 70 ARE EXPECTED.
RH VALUES ON WEDNESDAY COULD APPROACH CRITICAL LEVELS...HOWEVER
WINDS SHOULD REMAIN WELL BELOW RED FLAG CRITERIA. WHILE THERE WILL
BE A SLIGHTLY COOLER AIR MASS BEHIND A WEAK COLD FRONT WE SHOULD
STILL SEE ABOVE NORMAL TEMPS THURSDAY AND FRIDAY WITH HIGHS IN THE
UPPER 50S/LOW 60S AND LOWS IN THE 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1004 AM MST SAT NOV 17 2012
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH 06Z TONIGHT. AFTER THAT
TIME...PATCHY FOG EXPECTED TO DEVELOP ONCE AGAIN TOWARDS SUNRISE
SUNDAY MORNING WITH LIGHT WINDS AND CLEAR SKIES. TEMPORARY
VISIBILITY REDUCTIONS MAY OCCUR AT EITHER SITE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...024
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1001 AM PST Sat Nov 17 2012
.SYNOPSIS...
Today through next week expect a progressive and wet weather
pattern to return with periods of mountain snow and valley rain
this weekend and through next week. Higher snow levels Sunday
Night through Tuesday morning will combine with the heaviest
expected precipitation in this forecast cycle to produce rises on
the areas small stream or creeks...especially for North Idaho.
&&
.DISCUSSION...Based on radar and latest HRRR (Rapid Refresh)model
runs showing substantial precipitation activity drifting northeast
through the forecast area have increased pops with update. HRRR
does hint at a lull in KGEG vicinity as that area is between area
of rain exiting to the northeast and has a few hours before a
second larger and more intense area of rain approaching in similar
fashion from the southwest is overhead near 00Z but I`m not sure I
can get grid forecast timing to depict this well so will just
leave the rather high pops in place for the remainder of today.
/Pelatti
&&
.AVIATION...
18Z TAFs: Moist airmass remains overhead as flow from the south
along and ahead of approaching low pressure system continues to
influence Eastern Washington and Northern Idaho aviation area. As
such will continue to keep mostly MVFR ceilings and visibilities
with a snow level generally above 4000 FT MSL which means it is
above all TAF sites so rain is what is expected with the most
significant quantity falling near and after 00Z /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 37 45 38 42 40 / 70 100 50 100 100 100
Coeur d`Alene 48 37 45 36 42 40 / 70 100 50 90 100 100
Pullman 52 37 47 38 44 42 / 50 100 30 80 100 100
Lewiston 53 40 53 42 50 45 / 30 100 30 60 80 90
Colville 45 37 43 38 41 38 / 80 100 50 100 100 100
Sandpoint 47 37 44 35 41 38 / 70 100 100 90 100 100
Kellogg 48 37 41 34 39 39 / 60 100 100 60 100 100
Moses Lake 46 36 47 39 47 40 / 60 80 10 60 80 70
Wenatchee 42 37 45 38 44 39 / 60 60 20 90 80 70
Omak 42 35 42 37 42 39 / 90 100 30 100 100 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SPOKANE WA
9581 AM PST Sat Nov 17 2012
.SYNOPSIS...
Today through next week expect a progressive and wet weather
pattern to return with periods of mountain snow and valley rain
this weekend and through next week. Higher snow levels Sunday
Night through Tuesday morning will combine with the heaviest
expected precipitation in this forecast cycle to produce rises on
the areas small stream or creeks...especially for North Idaho.
&&
.DISCUSSION...Based on radar and latest HRRR (Rapid Refresh)model
runs showing substantial precipitation activity drifting northeast
through the forecast area have increased pops with update. HRRR
does hint at a lull in KGEG vicinity as that area is between area
of rain exiting to the northeast and has a few hours before a
second larger and more intense area of rain approaching in similar
fashion from the southwest is overhead near 00Z but I`m not sure I
can get grid forecast timing to depict this well so will just
leave the rather high pops in place for the remainder of today. /Pelatti
&&
.AVIATION...
18Z TAFs: Moist airmass remains overhead as flow from the south
along and ahead of approaching low pressure system continues to
influence Eastern Washington and Northern Idaho aviation area. As
such will continue to keep mostly MVFR ceilings and visibilities
with a snow level generally above 4000 FT MSL which means it is
above all TAF sites so rain is what is expected with the most
significant quantity falling near and after 00Z /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 37 45 38 42 40 / 70 100 50 100 100 100
Coeur d`Alene 48 37 45 36 42 40 / 70 100 50 90 100 100
Pullman 52 37 47 38 44 42 / 50 100 40 80 100 100
Lewiston 53 40 53 42 50 45 / 30 100 40 60 80 90
Colville 45 37 43 38 41 38 / 80 100 50 100 100 100
Sandpoint 47 37 44 35 41 38 / 70 100 80 90 100 100
Kellogg 48 37 41 34 39 39 / 60 100 80 60 100 100
Moses Lake 46 36 47 39 47 40 / 60 80 10 60 80 70
Wenatchee 42 37 45 38 44 39 / 60 60 20 90 80 70
Omak 42 35 42 37 42 39 / 90 100 30 100 100 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1122 AM CST SAT NOV 17 2012
.SHORT TERM...THROUGH MONDAY NIGHT
200 AM CST SAT NOV 17 2012
MAIN FORECAST CONCERNS ARE ON RAIN CHANCES SUNDAY NIGHT INTO MONDAY
NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED TROUGHING OFF BRITISH COLUMBIA...SUBTROPICAL RIDGING FROM
NORTHERN MEXICO TO LAKE ERIE...AND SHORTWAVES RIDING IN THE
SOUTHWEST SUBTROPICAL FLOW JUST OFF THE CALIFORNIA COAST AND NEAR
THE WY/SOUTH DAKOTA BORDER. THIS LATTER SHORTWAVE WAS PRODUCING A
MASS OF CIRRUS ACROSS THE DAKOTAS INTO NORTHWEST MINNESOTA. DRY LOW
TO MID LEVELS SEEN ON THE 00Z MPX...ABR AND UNR SOUNDINGS HAS
PREVENTED ANY LOWER CLOUD DEVELOPMENT. REGARDING THE DRYNESS...BOTH
MPX AND ABR SOUNDINGS ONLY HAD PRECIPITABLE WATER VALUES OF 0.20
INCHES. FARTHER TO THE EAST...AN AREA OF LOW STRATUS WAS PRESENT
ACROSS MUCH OF GRBS FORECAST AREA INTO LOCATIONS ALONG/NORTHEAST OF
I-94 IN OUR AREA. THIS STRATUS FORMED FROM SOUTHEAST ADVECTION OF
MOISTURE OFF LAKE MICHIGAN UNDERNEATH A SUBSIDENCE INVERSION...
COMBINED WITH LIGHT WINDS AND CLEAR SKIES EARLIER IN THE EVENING. A
STRONGER SOUTH FLOW ON THE BACK SIDE OF HIGH PRESSURE OVER LOWER
MICHIGAN HAS HELPED KEEP THE REST OF THE AREA LOW CLOUD FREE. THIS
FLOW...WHICH STRENGTHENS HEADING WEST TOWARDS THE DAKOTAS...HAS BEEN
BRINGING WARMER AIR INTO THE REGION. RAP ANALYSIS SHOWED 925MB TEMPS
OF 7C AT MPX COMPARED TO 2C ON THE 00Z SOUNDING. SURFACE
TEMPERATURES HAVE REFLECTED THE WARM ADVECTION WITH READINGS FROM
THE MID 20S TO MID 30S...WARMEST WEST OF THE MISSISSIPPI RIVER.
TODAY AND TONIGHT...THE SHORTWAVE ALONG THE WYOMING/SOUTH DAKOTA
BORDER IS PROGGED TO LIFT INTO NORTHERN MINNESOTA TONIGHT. THE TRACK
IS SLIGHTLY FARTHER NORTH THAN 24 HOURS AGO. WITH THE FARTHER NORTH
TRACK...THERE SHOULD BE A LITTLE LESS CLOUDS. SOME OF THE CIRRUS
STILL LOOKS SLATED TO CROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THIS EVENING...WITH SOME ALTOSTRATUS PRODUCED BY ISENTROPIC
LIFT AFTER MIDNIGHT. PLENTY OF LOW LEVEL DRY AIR WILL RESULT IN A
CONTINUATION OF THE DRY FORECAST. ONLY OTHER CLOUD COVER OF NOTE IS
THE EARLY MORNING STRATUS OVER THE NORTHEAST PORTION OF THE FORECAST
AREA...WHICH SHOULD SHIFT NORTHEAST DURING THE MORNING WITH THE
INCREASING SOUTH TO SOUTHWEST 950-925MB FLOW. THIS FLOW IS PROGGED
TO REACH 25-30KT TODAY AS THE GRADIENT TIGHTENS. WITH PLENTY OF
SUN...EXPECT BREEZY CONDITIONS...PARTICULARLY ON THE HIGHER TERRAIN
WEST OF THE MISSISSIPPI RIVER WHICH IS MORE EXPOSED AND IN THE
TIGHTEST GRADIENT. THE BREEZE SHOULD PERSIST INTO TONIGHT WITH THE
STRENGTHENING OF THE LOW LEVEL JET...NOTED TOO BY 950-925MB WINDS
INCREASING TO 30-45KT. THESE WINDS WILL CONTINUE TO BRING WARMER AIR
INTO THE REGION WITH 925MB TEMPS INDICATED BETWEEN 4-6C AT 18Z.
THESE SUPPORT HIGHS IN THE LOW TO MID 50S. FOLLOWED A BLEND OF
GUIDANCE FOR LOWS TONIGHT WITH THE BREEZE AND PASSING CLOUDS HELPING
TO PRODUCE A WARMER NIGHT.
SUNDAY INTO SUNDAY NIGHT...ATTENTION FOCUSES TO THE SHORTWAVE OFF
THE CALIFORNIA COAST. GOOD MODEL AGREEMENT EXISTS THAT THIS
SHORTWAVE WILL LIFT INTO THE CENTRAL PLAINS BY LATE SUNDAY...THEN
INTO WESTERN PORTIONS OF MINNESOTA AND IOWA BY 12Z MONDAY. RIDGING
LOOKS TO DEVELOP OVER THE FORECAST AREA FOR A TIME AHEAD OF THIS
SHORTWAVE AND IN THE WAKE OF THE SHORTWAVE LIFTING OUT OF NORTHERN
MINNESOTA. SUBSIDENCE UNDER THE RIDGE SHOULD THIN CLOUDS OUT SOME
FOR MUCH OF THE DAY UNTIL LATE. THIS IS WHEN THE AREA BEGINS TO FEEL
THE MOISTURE ADVECTION EFFECTS AHEAD OF THE SHORTWAVE...WHICH WILL
START PRODUCING AN ALTOSTRATUS DECK IN THE EVENING ACROSS THE AREA.
FURTHER LOWERING OF CEILINGS WILL OCCUR THROUGH THE NIGHT AS
PRECIPITABLE WATER VALUES CLIMB FROM AROUND 0.5 INCH AT 00Z TO NEAR
0.75 INCHES AT 12Z MONDAY. ALTHOUGH MOISTURE INCREASES...THE
ISENTROPIC LIFT IS QUITE WEAK...FOCUSED MAINLY WEST OF A LINE FROM
MEDFORD TO LA CROSSE AND OELWEIN BETWEEN 06-12Z. HAVE MAINTAINED A
20-30 PERCENT CHANCE FOR THIS AREA AND TIME PERIOD...BUT GIVEN THE
WEAK LIFT SIGNATURE IT IS POSSIBLE ANY PRECIPITATION HOLDS OFF UNTIL
AFTER 12Z MONDAY AS SUGGESTED BY THE 17.00Z GFS/NAM. 17.00Z ECMWF IS
MORE ROBUST...THOUGH. WARMER 925MB TEMPS IN THE 5-7C RANGE AT 18Z
SUNDAY PLUS THE SOUTHERLY BREEZE AND SUN SHOULD YIELD HIGHS IN THE
MID TO UPPER 50S. A FEW LOCATIONS MAY REACH OR EXCEED 60...
ESPECIALLY IF MORE SUN OCCURS. EVEN A WARMER NIGHT SHOULD OCCUR
SUNDAY NIGHT WITH MORE MOISTURE...CLOUDS AND THE BREEZE. LOWS WEST
OF THE MISSISSIPPI RIVER MAY NOT DIP BELOW 40.
MONDAY AND MONDAY NIGHT...THE SHORTWAVE TROUGH OVER THE PLAINS
MODELS AGREE ON BRINGING IT ACROSS THE FORECAST AREA MONDAY EVENING.
AS THE TROUGH APPROACHES MONDAY...THE ISENTROPIC LIFT LOOKS TO
INCREASE A LITTLE...ENOUGH TO WARRANT PRECIPITATION CHANCES AS HIGH
AS 40 PERCENT. KEPT THESE CHANCES LOW BECAUSE BOTH THE 17.00Z GFS
AND NAM SHOW A DRY LOOK TO THEIR QPF FIELDS. THE ECMWF REMAINS THE
MOST ROBUST...THOUGH ITS LATEST 17.00Z RUN HAS A SLIGHTLY DRIER LOOK
THAN ITS PREVIOUS 16.12Z RUN. MUCH OF THE RAIN...IF IT OCCURS...
SHOULD BE EAST OF THE AREA BY 00Z. HOWEVER...HAVE MAINTAINED A 20
PERCENT CHANCE OVER FAR EASTERN AREAS FROM 00-06Z SINCE THERE IS
STILL WEAK ISENTROPIC LIFT INDICATED ON THE 290-295K SURFACES.
PLENTY OF CLOUDS ON MONDAY WILL PREVENT TEMPERATURES FROM RISING AS
MUCH COMPARED TO THE WEEKEND. HAVE FOLLOWED A BLEND OF GUIDANCE FOR
HIGHS. CLOUDS GRADUALLY CLEARING OUT WEST TO EAST MONDAY NIGHT PLUS
LIGHTER WINDS RESULTING FROM A WEAKER PRESSURE GRADIENT SHOULD ALLOW
TEMPERATURES TO DIP INTO THE 30S TO AROUND 40 AT MOST LOCATIONS.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
200 AM CST SAT NOV 17 2012
THE MAIN ISSUE IN THE LONG TERM FORECAST IS A VERY POTENT SHORTWAVE
COMING OUT OF THE NORTHEAST PACIFIC TROUGH AND ENTERING THE PACIFIC
NORTHWEST TUESDAY EVENING. ALL MODELS AGREE ON UPPER RIDGING
BUILDING AHEAD OF THE POTENT SHORTWAVE INTO THE FORECAST AREA
TUESDAY NIGHT...RESULTING IN A SURGE OF WARM AIR ADVECTING INTO THE
AREA. 925MB TEMPS CLIMB FROM AROUND 6C AT 18Z TUESDAY TO 10-12C AT
18Z WEDNESDAY. 850MB TEMP ANOMALIES ON WEDNESDAY ARE 1.5 STANDARD
DEVIATIONS ABOVE NORMAL. PLENTY OF SUN LOOKS TO OCCUR AT LEAST ON
WEDNESDAY...AND PERHAPS TUESDAY TOO DEPENDING ON WHEN LOW CLOUDS
CLEAR ASSOCIATED WITH THE MONDAY/MONDAY NIGHT SHORTWAVE.
THEREFORE...THERE SHOULD BE DECENT MIXING DESPITE THE SHORTER DAY
LENGTH. HAVE LEANED ON THE WARM SIDE OF GUIDANCE AS A RESULT...
ESPECIALLY WEDNESDAY WHEN HIGHER CONFIDENCE EXISTS OF FULL SUN AND A
SOUTHERLY BREEZE IS PRESENT. HIGHS WEDNESDAY COULD REACH OR EXCEED
60...ABOUT 20 DEGREES ABOVE NORMAL. DRY AIR IN PLACE WILL PREVENT
ANY PRECIPITATION WITH THE WARM ADVECTION...AND PERHAPS CLOUDS TOO.
AS WE HEAD INTO THANKSGIVING AND THROUGH FRIDAY NIGHT...THE 17.00Z
CANADIAN/ECMWF/GFS AND GFS ENSEMBLES ALL POINT TO THE POTENT
SHORTWAVE DIGGING SOUTHEAST THROUGH THE UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DIFFERENT FROM THE 16.12Z ECMWF AND 16.00Z
GFS WHICH HAD MORE OF A FLATTER...ZONAL FLOW. THUS...WE WILL SEE IF
THIS IDEA OF THE SHORTWAVE DIGGING INTO THE AREA CONTINUES WITH
LATER RUNS. NOTE THAT THE 17.00Z GFS ENSEMBLES ARE ALL OVER THE
PLACE WITH THIS FEATURE. IN ANY EVENT...RIGHT NOW THERE IS GOOD
AGREEMENT ON IT OCCURRING FROM THE DETERMINISTIC MODELS...BUT TIMING
VARIES FROM THANKSGIVING DAY TO FRIDAY. FOR NOW HAVE STUCK WITH A
CONSENSUS APPROACH WHICH BRINGS THE POTENT TROUGH IN THANKSGIVING
DAY NIGHT. THUS...THANKSGIVING STILL LOOKS WARM AHEAD OF A COLD
FRONT MOVING IN. HIGHS MOST LOCATIONS SHOULD END UP IN THE 50S.
COOLER CONDITIONS ARE LIKELY ON FRIDAY IN THE WAKE OF THE COLD FRONT
AS 850MB TEMPS PLUMMET DOWN TO AT OR BELOW 0C BY 00Z SATURDAY.
REGARDING THE COLD FRONTAL PASSAGE FOR PRECIPITATION...RIGHT NOW IT
APPEARS STILL THAT THE AIRMASS IS TOO DRY BOTH BEHIND AND AHEAD OF
THE FRONT TO ALLOW FOR ANYTHING TO OCCUR. ANY PRECIPITATION SHOULD
STAY TO THE NORTH...CLOSER TO THE BETTER DYNAMICS...AND TO THE
SOUTHEAST WHERE A LONGER PERIOD OF MOISTURE RETURN CAN OCCUR.
&&
.AVIATION...THROUGH 18Z SUNDAY
1122 AM CST SAT NOV 17 2012
MAIN CONCERN THROUGH THE NEXT 24 HOURS WILL BE THE WINDS. THIS IS
A RESULT OF INCREASING PRESSURE GRADIENT BEHIND DEPARTING HIGH
PRESSURE OVER THE GREAT LAKES AND A TROUGH OF LOW PRESSURE MOVING
INTO THE NORTHERN PLAINS. SOUTH WINDS WILL BE IN THE 15 TO 25KT
RANGE THIS AFTERNOON ACROSS THE HIGHER-OPEN TERRAIN OF SOUTHEAST
MINNESOTA AND IN THE 10-20KT RANGE ELSEWHERE. LOOK FOR THE
GUSTINESS TO SUBSIDE TONIGHT AS THE ATMOSPHERE DECOUPLES WITH
SUNSET. HOWEVER...WINDS AROUND 1KFT AGL ARE EXPECTED TO REMAIN
AROUND 30-35KT WHICH COULD MAKE FINAL APPROACH/TAKE OFFS A BIT
BUMPY. WAS CONTEMPLATING INCLUDING SOME LLWS OVERNIGHT...BUT WILL
BE JUST A BIT SHY OF CRITERIA. AN INCREASE IN ALTOCUMULUS WILL
ALSO BE NOTED THIS EVENING/OVERNIGHT...THEN SCATTERING OUT BY LATE
SUNDAY MORNING. OTHERWISE...LOOK FOR SURFACE WINDS TO BECOME GUSTY
AGAIN AFTER SUNRISE. PLAN ON SOUTH WINDS AT 15-25KT ONCE AGAIN
ACROSS THE HIGHER TERRAIN OF SOUTHEAST MN...AND IN THE 10-20KT
RANGE ELSEWHERE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
200 AM CST SAT NOV 17 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1013 AM CST SAT NOV 17 2012
.UPDATE...QUIET WEATHER AND MILD TEMPS IN STORE FOR THE CWA...AS
HIGH PRESSURE IN THE EASTERN GREAT LAKES AND NE U.S. CONTINUES TO
INFLUENCE SOUTHERN WI. MINOR CHANGES MADE IN THIS UPDATE WITH THE
MAIN CONCERNS BEING HIGH TEMPS AND SKY COVER. THE LATTER IS MORE SO
IN REGARD TO LOW VIS AND LOW CLOUD DISSIPATION/IMPROVEMENT IN THE
NORTHWEST QUAD OF THE CWA THIS MORNING...WHERE VIS AND SKIES
CONTINUES TO IMPROVE FROM WHERE THE DENSE FOG ADVISORY WAS ALLOWED
TO EXPIRE AT 9 AM.
VIS SAT SHOWS CIRRUS OVER MUCH OF THE CWA...WITH FOG AND LOW CLOUDS
STILL EVIDENT IN PORTIONS NW. AT 9 AM...VIS WAS 3/4 SM AT
WAUTOMA...1 1/2 SM AT CAMP DOUGLAS...AND 5 SM AT THE WISCONSIN DELLS
AND FOND DU LAC. VIS SAT TRENDS CONTINUE TO SHOW FOG/LOW CLOUDS
MOVING NORTH/DISSIPATING AS EXPECTED...SHOULD BE OUT OF THE CWA
BETWEEN 10 AND 11 AM. ELSE...MOSTLY SUNNY SKIES CAN BE EXPECTED
TODAY AS BUFKIT SOUNDINGS SHOW DRY COLUMNS WITH ANY RESIDUAL
LOW-LEVEL MOISTURE FROM THIS MORNING DRYING OUT. 925 HPA TEMPS ARE
GENERALLY IN GOOD AGREEMENT WITH A RANGE FROM 7-5 C FROM SOUTHWEST TO
NORTHEAST. IF 925 TEMPS WERE MIXED DOWN DRY ADIABATICALLY...THIS
WOULD YIELD HIGHS AROUND 56-52 F. CURRENT FCST HIGHS ARE 53 FAR SW
TO 50 NE. HOWEVER...CONCERNS EXIST RELATED TO A COOL ON-SHORE FLOW
IN THE EAST AT THE SURFACE AND WHETHER MIXING WILL BE ADEQUATE.
BUFKIT RAP AND NAM SOUNDINGS SHOW THAT LOCATIONS IN THE CWA DO NOT
QUITE MIX OUT THAT HIGH...WITH JUST THE NAMS MSN AND MKX SOUNDINGS
SHOWING MIXING UP TO/NEAR 925 HPA. AS SUCH...DID NOT CHANGE TODAYS
HIGHS...BUT WILL MONITOR TO SEE HOW THE TEMPERATURE TREND FARES THE
REST OF THE MORNING BEFORE RULING OUT ANY CHANGES.
&&
.AVIATION/18Z TAFS/...CONDITIONS HAVE RETURNED TO VFR ACROSS MOST
OF SOUTHERN WISCONSIN THIS MORNING...WITH VFR CONDITIONS EXPECTED
TO PREVAIL THROUGH SUNDAY. WILL BE DRIER TONIGHT...WITH MORE MID
AND HIGH LEVEL CLOUDS AND HIGHER LOW LEVEL WINDS...SO NOT
EXPECTING A REPEAT OF THE FOG FROM LAST NIGHT.
&&
.PREV DISCUSSION... /ISSUED 332 AM CST SAT NOV 17 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
TODAY...EXPANDED DENSE FOG ADVISORY TO COVER THE REMAINDER OF
SOUTHEAST WISCONSIN AND NORTHERN SOUTH CENTRAL WISCONSIN AS
STRATUS IS SPREADING NORTHEAST. ALSO EXTENDED END TIME TO 9 AM CST
AS FORECAST SOUNDINGS SHOW LITTLE MIXING UNTIL THEN.
TIMING OF FOG AND LOW CLOUD DISSIPATION THIS MORNING WILL HAVE AN
IMPACT ON HIGH TEMPERATURES TODAY. MODELS IN GOOD AGREEMENT THAT
925 MB TEMPERATURES WILL BE IN THE +5C TO +6C RANGE...WITH +7C IN
THE FAR WEST...BY MID TO LATE AFTERNOON. NAM/GFS MODEL SOUNDINGS
MIXING DRY ADIABATICALLY TO THESE TEMPS ARE YIELDING LOW TO MID
50S HIGHS.
HOWEVER...WITH WARM AIR ADVECTION ON SOUTHWEST WINDS INCREASING TO
20-25 KNOT WINDS AT/ABOVE 1K FT OVER WEAKER SOUTHEAST WINDS THAT
WILL BE KEEPING THE NEAR SURFACE AIR COOLER...THE RAP SOUNDINGS
NEVER FULLY MIX OUT THE BOUNDARY LAYER INVERSION TO REACH 925 MB.
WENT WITH A BLENDED SOLUTION THAT LEANS TOWARD THE WARM SIDE IN
THE CURRENT FOG-FREE AREAS IN THE WEST...AND IS COOLER EAST WHERE
THE COMBINATION OF EARLY FOG...AND SOUTHEAST WINDS OFF THE MID-
UPPER 40 DEGREE LAKE WATER WILL LIMIT HIGHS.
TONIGHT...GRADIENT SHOULD BE SUFFICIENT FOR SOUTHERLY WINDS TO
KEEP THE BOUNDARY LAYER MIXED AND PREVENT FOG TONIGHT. EXPECT ONLY
SOME MID-HIGH LEVEL CLOUDS WITH A WEAK SHORT WAVE CROSSING REGION
OVERNIGHT.
SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
SOUTHWEST 500MB FLOW IS DEPICTED BY THE SHORT TERM MODELS ACROSS
THE REGION SUNDAY INTO MONDAY. SHORTWAVE TROUGH MOVES THROUGH THE
AREA FROM THE SOUTHWEST LATE SUNDAY NIGHT AND MONDAY...WITH A
TRAILING SHORTWAVE THEN SHIFTING EAST SOUTHEAST INTO THE AREA
MONDAY NIGHT. AT THE SURFACE...MILD SOUTHERLY FLOW CONTINUES
ACROSS THE REGION SUNDAY INTO MONDAY...WITH A SURFACE TROUGH
MOVING EASTWARD INTO THE AREA MONDAY NIGHT.
AREA FORECAST SOUNDINGS FROM NAM/GFS SHOW SOME MID TO HIGH CLOUDS
SUNDAY INTO SUNDAY NIGHT...WITH MORE CLOUDS MONDAY/MONDAY NIGHT
WITH PASSAGE OF SHORTWAVES AND SURFACE TROUGH. SOUNDINGS DO
INDICATE AIR COLUMN BECOMING MOIST IN THE LOW LEVELS MONDAY
NIGHT...BUT THE MID TO UPPER LEVELS DRY OUT. LIGHT QPF IS SEEN
ACROSS PORTIONS OF THE AREA MONDAY AND MONDAY NIGHT.
CONTINUED TO MENTION LOW END POPS FOR MONDAY AND MONDAY NIGHT.
TEMPERATURES WILL REMAIN ABOVE NORMAL...WITH HIGHS WELL INTO THE
50S SUNDAY AND MONDAY PER NAM 925MB TEMPERATURES. LOWS WILL
MODERATE FROM THE 30S SUNDAY NIGHT TO THE LOWER TO MID 40S MONDAY
NIGHT.
TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
GFS AND ECMWF SHOW GOOD AGREEMENT WITH FEATURES TUESDAY THROUGH
WEDNESDAY NIGHT. THEY SHOW THE SHORTWAVE TROUGH PUSHING THROUGH
AND EAST OF THE AREA TUESDAY. AREA GFS FORECAST SOUNDINGS SHOW
SOME LOW LEVEL MOISTURE LINGERING...BUT A DRY AIR COLUMN ABOVE IT.
KEPT LOW POPS TUESDAY MORNING IN THE FAR EAST/SOUTHEAST COUNTIES
IN THE MORNING...THEN DRY IN THE AFTERNOON.
BOTH MODELS THEN SHOW A 500MB RIDGE AXIS PASSING THROUGH THE AREA
TUESDAY NIGHT AND WEDNESDAY...WITH SOUTHWEST FLOW IN PLACE
WEDNESDAY NIGHT. SOUTH TO SOUTHWEST FLOW IN THE LOW LEVELS WITH
WARM AIR ADVECTION WILL OCCUR ACROSS THE REGION. AREA GFS FORECAST
SOUNDINGS REMAIN DRY DURING THIS TIME.
THUS...QUIET WEATHER IS EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT...WITH ABOVE NORMAL TEMPERATURES CONTINUING. GIVEN THE
EXPECTED NAM 925MB TEMPERATURES...MAY REACH AS HIGH AS AROUND 60
ON WEDNESDAY.
THANKSGIVING DAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
GFS AND ECMWF THEN DIFFER SOMEWHAT WITH FEATURES THURSDAY THROUGH
FRIDAY. THE GFS AND ECMWF BRING DEVELOPING LOW PRESSURE EAST FROM
NORTHERN MINNESOTA TO LAKE SUPERIOR THURSDAY...THEN NORTHEAST AS
IT BECOMES STRONGER THURSDAY NIGHT AND FRIDAY.
THE GFS HAS A COLD FRONT WITH LIGHT QPF MOVING EAST THROUGH THE
AREA THANKSGIVING DAY...FOLLOWED BY A STRONG VORTICITY MAXIMUM
PASSING THROUGH THURSDAY NIGHT INTO FRIDAY. THEY BOTH DO SHOW
BRISK WEST/NORTHWEST WINDS BRINGING COLDER AIR INTO THE REGION
THURSDAY NIGHT INTO FRIDAY. THE ECMWF BRINGS A DRY COLD FRONTAL
PASSAGE THURSDAY NIGHT. IT ALSO BRINGS A SECONDARY VORTICITY
MAXIMUM THROUGH THE AREA FRIDAY.
FOR NOW...WILL USE BLENDED POPS AND TEMPERATURES FOR THANKSGIVING
DAY THROUGH FRIDAY. THIS WILL MEAN DRY CONDITIONS AND CONTINUED
MILD TEMPERATURES. HIGHS THANKSGIVING DAY SHOULD REACH WELL INTO
THE 50S BEFORE THE FRONT MOVES THROUGH.
AVIATION/12Z TAFS/...WILL KEEP IFR/LIFR CONDITIONS AT AREA TAF
SITES UNTIL AT LEAST 13Z...AND POSSIBLY 14-15Z IN THE EAST...UNTIL
DAYTIME MIXING INCREASES WINDS AND RAISES CIGS AND VISIBILITIES.
SHOULD SEE VFR CONDITIONS ACROSS THE FORECAST AREA BY MID TO LATE
MORNING...WITH QUIET WEATHER THEN EXPECTED THROUGH THE REST OF THE
FORECAST PERIOD WITH VFR CONDITIONS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...WOOD