FXUS61 KALY 251119
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
620 AM EST WED NOV 25 2009
.SYNOPSIS...
WEAK HIGH PRESSURE WILL DRIFT TO THE GULF OF MAINE TODAY WHILE A
VERY WEAK DISTURBANCE BRINGS A FEW VERY LIGHT SHOWERS TO SOME SPOTS
BY AFTERNOON. OUR REGION WILL BE BETWEEN TWO STORM SYSTEMS ON
THANKSGIVING DAY WHICH WILL YIELD A DRY MILD DAY. AN STRONG UPPER
LEVEL STORM SYSTEM WILL ACROSS THE REGION ON FRIDAY BRINGING
UNSETTLED WEATHER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADARS INDICATING SOME SPRITZ MOVING UP ACROSS THE
ADIRONDACKS...WITH PERHAPS AN HUNDREDTH OF AN INCH OR TWO. WHILE A
STORM SYSTEM IN THE OHIO VALLEY WILL MISS US BY GOING NORTH...A
PIECE OF VORTICITY HAS BROKEN AWAY FROM THE MAIN FEATURE (ALONG WITH
A VERY WEAK SURFACE TROUGH). THIS VERY WEAK DISTURBANCE IS
RESPONSIBLE FOR THE VERY LIGHT SHOWERS WHICH WITH TIME...WILL
ATTEMPT TO PROPAGATE EASTWARD ACROSS THE REMAINDER OF THE REGION BY
AFTERNOON. AT MOST...SCATTERED LIGHT SHOWERS MIGHT BRING A COUPLE OF
HUNDREDTHS OF AN INCH IN A FEW SPOTS BUT THIS SYSTEM SHOULD HAVE NO
IMPACT ON TRAVEL. KEEP IN MIND...THAT MANY SPOTS WILL NOT RECEIVE
ANY SHOWER ACTIVITY.
HOWEVER...PATCHY DENSE FOG COULD BE A PROBLEM FOR SOME EARLY IN THE
MORNING BEFORE BURNING OFF.
WITH THE DISTURBANCE THERE WILL BE LOTS OF CLOUDS TODAY...BUT A FEW
BREAKS OF SUNSHINE ARE POSSIBLE. WITH MORE CLOUDS AND THE WIDELY
SCATTERED SHOWERS...LOWERED TEMPS A COUPLE OF POINTS COMPARED TO
WHAT WE HAD YESTERDAY. ACTUALLY WENT A DEGREE HIGHER THAN THE
MET/MAV BLENDS WHICH FOR A CHANGE...WERE CLOSE TO EACH OTHER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THE REASON THE OHIO STORM WILL MAINLY MISS US (EXCEPT FOR THE
VORTICITY PIECE) IS BECAUSE ANOTHER SYSTEM WAS DIVING SOUTH FROM
MANITOBA CANADA. THIS SYSTEM IS FORCING THE FIRST ONE TO EJECT
NORTHWARD INTO ONTARIO. THIS SECOND SYSTEM IS THE ONE THAT WILL
LIKELY IMPACT OUR REGION ON FRIDAY. HOWEVER...BEFORE THEN...OUR AREA
WILL BE SANDWICHED BETWEEN A DEVELOPING OCEAN STORM WELL TO OUR
EAST...AND THE IMPENDING UPPER AIR LOW SYSTEM TO OUR WEST ON
THANKSGIVING DAY.
THE AFOREMENTIONED WEAK DISTURBANCE MIGHT STILL BRING A SHOWER OR
TWO THIS EVENING BEFORE LIFTING TO OUR NORTHEAST OVERNIGHT. BEHIND
IT...WITH NO REAL HIGH PRESSURE IN PLACE...CLOUDS COULD BE SLOW TO
BREAK UP (IF AT ALL). WITH DRYING IN THE MID LEVELS BUT MOISTURE
POSSIBLY INCREASING IN THE LOWER LEVELS...A LITTLE PATCHY DRIZZLE
MIGHT ENSUE OVERNIGHT TONIGHT.
THEN ON THANKSGIVING DAY...THE BIGGEST CHALLENGE WILL BE PREDICTING
THE SKY COVER. OTHERWISE...IT SHOULD BE A DRY DAY. OUR THINKING IS
THE DAY WILL START OFF CLOUDY (OR MOSTLY CLOUDY) WITH SOME MIDDAY
BREAKS BEFORE CLOUDS REDEVELOP AGAIN LATE IN THE DAY. THROUGH IT
ALL...WE WILL ENJOY ONE MORE MILD DAY AS H850 TEMPERATURES REMAIN IN
THE 1C-3C WITH AN OPPORTUNITY FOR LITTLE MORE MIXING COMPARED TO
PREVIOUS DAYS. EVEN WITH MORE CLOUDS THAN SUNSHINE...TEMPERATURES
WILL GENERALLY TOP OUT IN THE 50-55 RANGE...EXCEPT 45-50 IN MOUNTAIN
AREAS. THESE VALUES ARE A GOOD 5-7 DEGS ABOVE SEASONAL AVERAGES. IT
LOOKS AS IF NO THANKSGIVING WEATHER RECORDS WILL BE THREATEN IN THE
ALBANY (RAINFALL/SNOWFALL/TEMPERATURES ETC.). IT WILL BE
CONSIDERABLY MILDER THAN LAST YEAR WHEN THE HIGH WAS ONLY 43 DEGREES
IN ALBANY.
BY THANKSGIVING NIGHT...THE NEW UPPER AIR LOW WILL BE APPROACHING
WESTERN NEW YORK STATE. AT THE SAME TIME...THE DEVELOPING COASTAL
STORM...A SPIN OFF FROM THE SOUTHERN SUBTROPICAL JET WILL BE TO OUR
EAST. THE HUGE WEATHER PROBLEM IS WHETHER OR NOT ENERGY FROM THE
OCEAN STORM WILL PHASE WITH THE ENERGY FROM THE NORTHERN BRANCH
(UPPER AIR LOW). IF IT WERE...A SIGNIFICANT PRE WINTER STORM WOULD
ENSUE. HOWEVER...THE SIGNALS ARE NOT CLEAR THAT A FULL PHASING WILL
HAPPEN.
THE GFS/EUROPEAN/CANADIAN MODELS SUGGEST THAT A FULL PHASING WILL
NOT OCCUR...UNTIL BOTH SYSTEM ARE NORTH AND EAST OF OUR REGION. THAT
IS NOT TO SAY WE WILL ESCAPE PRECIPITATION. THERE IS A LOT OF
MOISTURE WITH THE SOUTHERN STORM NOTED ON THE WATER VAPOR LOOP. IT
DOES APPEARS THAT SOME OF THIS MOISTURE WILL BE EJECTED INTO THE
UPPER LEVEL SYSTEM...WITH OR WITHOUT THE SURFACE STORM.
THE NAM CONTINUES TO MORE OF AN OUTLIER...SUGGESTING MOISTURE WILL
BE VERY LIMIT WITH THE UPPER AIR LOW...AS THE SURFACE LOW IS EVEN A
LITTLE FURTHER AWAY FROM THE UPPER AIR STORM.
THEE IS STILL A BIT SPREAD OF THE SURFACE TRACK ON THE GFS
ENSEMBLES.
BOTTOM LINE...A LOT UNCERTAINTY STILL CONTINUES WITH THE EVOLUTION
OF THIS UPCOMING STORM. THE FIRST OHIO VALLEY STORM...THE ONE THAT
WILL GET EJECTED NORTHWARD...MIGHT HAVE ENOUGH PUSH TO DISPLACE THE
BAROCLINIC ZONE FURTHER SOUTH AND EAST WHICH WOULD FORCE THE COASTAL
STORM TO STAY FURTHER TO OUR EAST. THUS FAR...THIS BAROCLINIC ZONE
IS NOT IMPRESSIVE...BUT WILL BECOME MORE SO BY THURSDAY NIGHT.
FOR THE ABOVE REASONS...WILL CONTINUE WITH LIKELY POPS LATE
THANKSGIVING NIGHT AND FRIDAY (AS OPPOSED TO CATEGORICAL). MOST
MODELS ARE PICKING UP ON SOME ELEVATION DIFFERENCE IN QPF...WHICH
SEEMS VERY REASONABLE GIVEN PAST CSTAR RESEARCH ON THE MATTER OF
COLD CUTOFF LOWS. THE STUDIES HAVE INDICATE HIGHER TERRAIN COULD
RECEIVE UP TO SEVERAL TIMES MORE PRECIPITATION THAN THE VALLEY
AREAS.
THE 00Z EUROPEAN DEVELOPS A DEFORMATION ZONE TO THE EAST OF
THE HUDSON VALLEY WHILE THE 00Z GFS DEVELOPED IT TO THE WEST. EITHER
WAY...IT WILL TAKE MORE TO DETERMINE WHERE ANY PRECIPITATION MAXIMA
WOULD TAKE PLACE.
PRECIPITATION IS LIKELY TO OVERSPREAD THE REGION LATE THURSDAY NIGHT
INTO FRIDAY. INITIALLY THE AIR LOOKS WARM ENOUGH FOR ALL RAIN...EVEN
IN THE MOUNTAINS. HOWEVER...WITH TIME...THE COLUMN WILL COOL ENOUGH
FOR A CHANGEOVER TO SNOW ACROSS THE HIGHER TERRAIN. IT MIGHT TAKE
MOST OF THE DAY FRIDAY FOR THIS TO HAPPEN. HOWEVER...IF
PRECIPITATION AMOUNTS ARE HEAVIER THAN WHAT WE ARE CURRENTLY
FORECASTING...COOLING FROM MELTING SNOWFLAKES COULD COOL THE COLUMN
DOWN MUCH FASTER. RIGHT THOUGH...THE PROBABILITY OF A 24-HR ONE INCH
PRECIPITATION AMOUNTS LOOKED SMALL ON THE 00Z MREFS AND EVEN SMALLER
ON THE SREFS.
OVERNIGHT LOW TEMPERATURES THANKSGIVING NIGHT LOOKS TO BE IN 30S
BUT ABOVE FREEZING. THEN...THEY PROBABLY WILL NOT RISE MUCH ON
FRIDAY...AND IN SOME CASES MIGHT ACTUALLY FALL...AS THE WIND TURNS
NORTH TO NORTHWESTERLY AND THE H850 TEMPERATURE COOL BELOW
0C...WHILE H925 TEMPERATURES APPROACH ZERO IN THE MOUNTAINS.
LEFT-OVER "WRAP AROUND" MAINLY UPSLOPE PRECIPITATION LOOKS TO LINGER
INTO FRIDAY NIGHT. BY THIS TIME...TEMPERATURES WILL DROP AROUND THE
FREEZING MARK IN VALLEY LOCATIONS....20S OVER THE MOUNTAINS. THERE
IS A POTENTIAL FOR DUSTING OF SNOW EVEN IN VALLEY LOCATIONS...AND
PERHAPS SEVERAL INCHES OVER THE HIGHER TERRAIN. THE OCEAN STORM
SHOULD BE A FULL BLOWN NOR'EASTER BY FRIDAY NIGHT...SITTING OVER THE
GULF OF MAINE. AS IT BEGINS TO PULL AWAY...A GUSTY NORTHWEST WIND
WILL KICK IN. MORE ABOUT THAT WILL FOLLOW IN THE LONG TERM
DISCUSSION.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
IN THE WAKE OF THE NOR-EASTER...COLD ADVECTION WILL PURSUE ON THE
HEELS OF STRONG WESTERLY WINDS. MOMENTUM TRANSFER POTENTIAL
SUGGESTS WE EFFECTIVELY TAP INTO THE MID-UPPER 40KT RANGE AS THIS
WOULD QUALIFY FOR WIND HEADLINES ON SATURDAY. WE WILL CONTINUE TO
HIGHLIGHT IN THE HWO THIS MORNING. FURTHERMORE...WITH THE COLDER
AND MOIST CYCLONIC FLOW AND CONTRIBUTIONS FROM LAKE
ONTARIO...RAIN/SNOW SHOWERS ARE EXPECTED. WITH FAVORABLE UPSLOPE
AREAS SUCH AS THE DACKS...SOUTHERN GREENS AND PORTIONS OF THE
CATSKILLS...POTENTIAL FOR ACCUMULATING SNOW AS THE BOUNDARY LAYER
CONTINUES TO COOL OFF THROUGH THE DAY.
SATURDAY NIGHT...WEATHER IMPROVES QUICKLY AS SURFACE PRESSURE
GRADIENT RELAXES AND DECOUPLING OCCURS AS SURFACE TEMPS ARE EXPECTED
TO COOL OFF RATHER QUICKLY DURING THE EVENING. SUBSIDENCE WILL ALSO
INCREASE WHICH WILL AID IN THE REDUCTION OF CLOUD COVER FOR A CHILLY
NIGHT. DEPENDING ON WHERE SNOW COVER SETS UP WILL DICTATE THE
OVERNIGHT LOWS. FOR NOW...WE WILL GENERALLY FAVORS THE 20S FOR THE
MAJORITY OF THE CWA.
FOR THE SECOND HALF OF THE WEEKEND...UPSTREAM THE NEXT TROUGH
EVOLVES AS STRONG PACIFIC SYSTEM COMES ASHORE. THE UPPER PATTERN
FAVORS A MORE ELONGATED LONG WAVE TROUGH THIS TIME AROUND WHICH WILL
ALLOW FOR MORE POSITIVE RESPONSE FROM THE GULF OF MEXICO. SUNDAY
SHOULD REMAIN DRY AND SEASONABLE AS THIS UPSTREAM FEATURE/S/ UNFOLD.
FOR EARLY NEXT WEEK...MODELS WILL NATURALLY HAVE DIFFICULTY WITH
RESOLVING WAVES AND STRENGTH OF THESE SYSTEMS. CONSENSUS FAVORS AN
INCREASE IN CLOUD COVER AND PRECIPITATION AS GULF MOISTURE TRANSPORT
INCREASES OVER THE EASTERN US.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VARIETY OF FLIGHT CATEGORIES THIS MORNING ACROSS THE TAF SITES WITH
A SOLID STRATUS DECK SOUTH OF THE CAPITAL REGION /MVFR CIG/ AND
POCKETS OF IFR FROM THE CAPITAL REGION AND POINTS NORTH DUE TO FOG.
WITH AN INFLUX OF MOISTURE CONTINUING THROUGH THE DAY...TAF SITES
ARE EXPECTED TO BECOME MORE UNIFORM WITH MVFR CIGS WITH A LIGHT
SOUTH-SOUTHEAST WIND. THERE COULD BE SOME LIGHT RAIN SHOWERS...AS
SEEN ON THE RADAR THIS MORNING OVER CENTRAL NY AND THE
DACKS...APPROACHING THIS AFTERNOON FOR THE HUDSON RIVER VALLEY AND
WILL PLACE VCSH AT THIS TIME.
LOW LEVEL MOISTURE IS EXPECTED TO QUICKLY INCREASE TOWARD THIS
EVENING WITH THE CHANCE FOR EITHER LIGHT RAIN/DRIZZLE. THIS TOO
WILL LOWER THE CIGS DOWN TO AT LEAST IFR...PERHAPS LOWER...AND WE
WILL CONTINUE TO MONITOR TRENDS.
OUTLOOK...
THANKSGIVING DAY...VFR TO MVFR...CIG...NO SIG WX AT THIS TIME.
THU NGT-FRI...MVFR/IFR...-SHRA/PDS -RA. CHC LLWS.
FRI NGT-SAT...MVFR/IFR...-SHRA CHG TO -SHSNRA. POSS LLWS. WINDY.
SUN...VFR. NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS THROUGH THANKSGIVING DAY.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION WILL BE FROM LATE
THURSDAY NIGHT INTO THE EARLY PART OF THE WEEKEND...AS A POTENTIALLY
STRONG STORM MAY IMPACT THE REGION. HOWEVER...AT THIS POINT...
ENOUGH RAINFALL TO SIGNIFICANTLY IMPACT AREA STREAMS AND RIVERS DOES
NOT APPEAR LIKELY AS RIVER BASIN AVERAGE ARE FORECASTED TO REMAIN
BELOW AN INCH REGION WIDE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...BGM
AVIATION...BGM
HYDROLOGY...HWJIV/GJM
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