Forecast Discussion November 18, 2015

766
FXUS61 KALY 182346
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
646 PM EST WED NOV 18 2015

.SYNOPSIS…
A WARM FRONT WILL WORK ACROSS OUR REGION TONIGHT…KEEPING
TEMPERATURES MILD UNDER A CANOPY OF INCREASING CLOUDS. SPOTTY
DRIZZLE WILL BREAK OUT EARLY THURSDAY…FOLLOWED BY HEAVIER
SHOWERS LATER IN THE DAY WHICH WILL BE AHEAD OF A COLD FRONT THAT
WILL CROSS OUR REGION THURSDAY NIGHT. COOLER DRIER AIR WILL FOLLOW
FOR FRIDAY… FOLLOWED BY EVEN COLDER AIR AND SOME SHOWERS OF RAIN
OR SNOW FOR LATER IN THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/…
AS OF 630 PM EST…CLOUDS CONTINUED TO OVERSPREAD THE REGION.
TEMEPRATURES REMAINED MILD…BETWEEN THE MID 40S AND LOWER 50S MOST
PLACES…AND UPPER 30S TO LOWER 40S OVER EXTREME EASTERN BERKSHIRE
COUNTY AND WINDHAM COUNTY.

A SOUTH TO SOUTHEAST BREEZE AVERAGED 10-15 MPH…WITH SOME GUSTS TO
20 MPH OR A LITTLE HIGHER.

EVEN FURTHER SOUTH ACROSS THE MID ATLANTIC…TEMPERATURES WERE IN
THE 60S WITH DEWPOINTS SURGING THROUGH THE 40S. THE LEADING EDGE OF
THIS MILDER AND MORE MOIST AIR MASS WAS PRODUCING THE STRATUS
WHICH CONTINUED TO SPREAD NORTH AND WAS NOW COVERING ALL BUT THE
NORTHERNMOST AREAS. THESE CLOUDS…ADDITIONAL WARM AIR ADVECTION
AND A PERSISTENT BREEZE SHOULD KEEP TEMPERATURES FROM FALLING MUCH
AT ALL. THEREFORE…WE WENT A BIT HIGHER THAN ALL MACHINE GUIDANCE
REGARDING OVERNIGHT LOWS.

LOWS WILL BE IN THE 40S…UPPER 40S LOCALLY IN THE CAPITAL REGION.

AS THE MOISTURE DEEPENS OVERNIGHT THERE MIGHT BE A LITTLE SPOTTY DRIZZLE…
MAINLY ACROSS OUR CATSKILLS DUE TO UPSLOPE BUT EVEN THE MID HUDSON VALLEY
LITCHFIELD AND THE SOUTHERN BERKSHIRES COULD SEE SOME SPOTTY DRIZZLE BY
MIDNIGHT. BY DAYBREAK…EVERYONE COULD SEE A LITTLE SPOTTY DRIZZLE OR A LIGHT
SHOWER ON AN ISOLATED BASIS.

THE SOUTH TO SOUTHEAST BREEZE WILL AVERAGE 5-15 MPH TONIGHT…WITH SOME
HIGHER GUSTS…ESPECIALLY ACROSS THE HIGHER TERRAIN.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/…
BY THURSDAY…OUR WHOLE AREA WILL BE IN A MOIST MILD AIR MASS
WITH A COLD FRONT RAPIDLY APPROACHING FROM THE WEST.

THIS IS THE SAME SYSTEM THAT PRODUCED QUITE AN ARRAY OF FOUL WEATHER
OUT WEST…INCLUDING SEVERE WEATHER AND EVEN BLIZZARD CONDITIONS.
NEITHER IS EXPECTED FOR US (INSTABILITY NOT THERE FOR ANY REAL
CONVECTION). A RUMBLE OF THUNDER IS CERTAINLY POSSIBLE BUT WITH
SHOWALTER VALUES >0 AND CAPE VALUES NEAR 0 J/KG WILL KEEP
ANY MENTION OF THUNDERSTORMS OUT OF THE GRIDS FOR NOW.

THAT SAID…WITH PWATS SOARING PAST AN INCH….TWO STANDARDS ABOVE
NORMAL. THE COMBINATION OF THIS MOISTURE…THE FRONT…SHORTWAVE
ENERGY AND OUR AREA COMING UNDER THE DIVERGENT AREA OF THE RR 100KT
NIGHT BY EVENING…ALL POINT TO ROUND OF SHOWERS…SOME CONTAINING
MODERATE TO POSSIBLY LOCALLY HEAVY RAINFALL.

WHAT IS A LITTLE DIFFERENT FROM PREVIOUS RUNS…THERE IS LESS OF TENDENCY FOR
A SECONDARY WAVE TO DEVELOP ALONG THE TRIPLE POINT…AS THERE WAS
IN SOME EARLIER RUNS. IT LOOKS LIKE A PROGRESSIVE SYSTEM…PRETTY MUCH
WHAT WE HAVE SEEN THIS AUTUMN.

A GUSTY SOUTH WIND WILL ENSUE ON THURSDAY…10-15 MPH…WITH GUSTS
25-35 MPH ACROSS PORTIONS OF THE HIGHER TERRAIN…AND EVEN
SOME SECTIONS OF THE CAPITAL REGION AND MOHAWK VALLEY. DURING
HEAVY SHOWERS…IT IS REMOTELY POSSIBLE THAT SOME GUSTS COULD EVEN
REACH A LITTLE HIGHER THAN THAN THAT…BUT JUST BRIEFLY.
THEREFORE…NO WIND HEADLINES WERE ASSIGNED WITH THIS PACKAGE.

THE ACTUAL COLD FRONT LOOKS TO MOVE ON THROUGH THURSDAY EVENING…
FOLLOWED BY HIGH PRESSURE BEGINNING TO BUILD IN BY EARLY FRIDAY.
IN FACT…THE SKY MIGHT ACTUALLY CLEAR BY DAYBREAK FRIDAY OR AT
LEAST PARTIALLY CLEAR.

BASED ON UPSTREAM TEMPERATURES WELL INTO THE 60S…WE WILL GO SLIGHTLY
HIGHER THAN ALL MACHINE GUIDANCE ON THURSDAY. LOOK FOR HIGHS LOWER TO MID
60S IN THE VALLEYS…MID OR UPPER 50S EVEN ACROSS THE HIGHER TERRAIN.

TURNING COOLER…BUT STILL ABOVE NORMAL THURSDAY NIGHT WITH LOWS
RANGING FROM THE UPPER 30S TO MID 40S.

FRIDAY SHOULD FEATURE AT LEAST PARTIAL SUNSHINE AS THE FLOW LOOKS TOO ANTI-
CYCLONIC FOR MUCH LAKE INDUCED CLOUDS (OUTSIDE OF THE ADIRONDACKS WHERE
UPSLOPE CLOUDS AND A FEW SHOWERS OF RAIN OR RAIN AND WET SNOW MIXED ARE
POSSIBLE).

HIGH TEMPERATURES WILL BE NOTICEABLY COOLER THAN THURSDAY…HIGHS NEAR 50
IN THE VALLEYS…LOWER TO MID 40S HIGHER TERRAIN…CLOSER TO 40
ACROSS THE ADIRONDACKS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/…
THE EXTENDED OPENS WITH A POTENT UPPER LEVEL TROUGH APPROACHING FROM
THE GREAT LAKES REGION AND THE MIDWEST. THE UPPER LEVEL TROUGH
TURNS NEGATIVELY TILTED ACCORDING TO LATEST GFS/ECMWF…AS THE SFC
CYCLONE LIFTS NORTHEAST ACROSS THE ERN GREAT LAKES REGION INTO SE
ONTARIO BY 12Z SUN. THERE IS ENOUGH MOISTURE WITH THE OCCLUDED
FRONT TO THE SYSTEM FOR A PERIOD OF RAIN SHOWERS TRANSITIONING TO
SNOW SHOWERS. THERE IS DECENT LIFT AND CONVERGENCE WITH THE
BOUNDARY. SOME LIGHT SNOW ACCUMULATIONS ARE POSSIBLE WITH A COATING
TO LESS THAN A HALF AN INCH IN THE VALLEY AREAS…AND AN INCH OR TWO
OVER THE HIGHER TERRAIN. THE LIGHT SNOW IS SUPPORTED FROM SOME OF
THE ENSEMBLES. THE LATEST GEFS PLUME DIAGRAM YIELDS ABOUT A TENTH OF
AN INCH OF SNOWFALL FOR ALBANY WITH PERHAPS A HALF DOZEN MEMBERS OR
SO. LOWS SAT NIGHT WILL RANGE FROM THE MID AND U20S OVER THE MTNS TO
U20S TO L30S OVER THE VALLEYS.

SUNDAY WILL BE A BLUSTERY AND COLD DAY WITH THE LONG-WAVE TROUGH
AXIS APPROACHING THE REGION. A SECONDARY COLD FRONT OR SFC TROUGH
WILL MOVE THROUGH WITH H850 TEMPS FALL TO -7C TO -10C. SOME SCT
SNOW AND RAIN SHOWERS ARE POSSIBLE. THE RAIN SHOWERS WILL BE MAINLY
WHERE THE BOUNDARY LAYER WARMS ENOUGH WITH TEMPS IN THEN 40-45F
RANGE. THE HIGHER POPS WILL BE NORTH AND WEST OF THE CAPITAL
DISTRICT AND THE MOHAWK RIVER VALLEY. SOME ADDITIONAL LIGHT SNOW
ACCUMS ARE POSSIBLE OVER THE WRN DACKS…ERN CATSKILLS…AND SRN
GREENS. HIGHS WILL BE MAINLY IN THE U30S TO L40S IN THE
VALLEYS…AND LOWER TO U30S OVER THE HIGHER TERRAIN…EXCEPT SOME
U20S IN THE SRN DACKS.

SUNDAY NIGHT INTO MONDAY…A COLD AIR MASS BUILDS IN FROM THE OHIO
VALLEY WITH SOME LAKE EFFECT SNOWFALL POSSIBLE BASED ON THE MEDIUM
RANGE GUIDANCE. LOCATIONS IN THE WRN DACKS…AND W-CNTRL MOHAWK
VALLEY MAY GET AT LEAST SOME LIGHT SNOW ACCUMS. THE REST OF THE FCST
AREA WILL REMAIN DRY…BUT COLD. THE LATEST GFS H850 TEMPS FALL TO
-10C TO -13C OVER THE FCST AREA. LOWS WILL BE IN THE MID AND U20S IN
THE VALLEYS…AND TEENS TO L20S OVER THE MTNS. HIGHS ON MONDAY
RANGE FROM THE U30S TO L40S IN THE VALLEY AREAS…AND U20S TO M30S
OVER THE MTNS.

MONDAY NIGHT INTO TUESDAY…THE LAKE EFFECT SNOWFALL SHOULD
TAPER…AS THE FLOW BECOMES MORE ZONAL. A WEAK DISTURBANCE IN THE
ZONAL FLOW COULD BRING A SLIGHT CHC OF SHOWERS TUE AFTERNOON WEST OF
THE MOHAWK VALLEY. THE ECMWF REMAINS DRY. TEMPS MODERATE TO
SEASONAL VALUES ON TUESDAY WITH SOME MID AND U40S IN THE CAPITAL
DISTRICT…TACONICS…MID HUDSON VALLEY…AND NW CT. U30S TO L40S
ARE COMMON NORTH AND WEST.

TUESDAY NIGHT INTO WEDNESDAY…HIGH PRESSURE WILL RIDGE BACK IN OVER
THE NORTHEAST WITH FAIR AND DRY WEATHER FOR THE MID WEEK…AND
SEASONABLE TEMPS.

OVERALL…TEMPS WILL AVERAGE NEAR NORMAL WITH PCPN BELOW NORMAL IN
THE LONG TERM.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/…
MVFR CIGS ALREADY OCCURRING AT KPOU/KPSF…AND EXPECT MVFR CIGS TO
MOVE INTO KALB ND KGFL BEFORE MIDNIGHT. THEN MVFR CIGS AND
POSSIBLE MVFR VSBYS WILL OCCUR FOR THE REST OF THE NIGHT AS SOME
FOG OR DRIZZLE DEVELOPS ACROSS THE REGION. IFR CIGS ARE ALSO
POSSIBLE AT KPOU/KPSF LATE TONIGHT…ESPECIALLY AT KPSF WHERE THE
IFR CIGS COULD START AROUND 06Z.

MVFR/IFR CIGS WILL PERSIST INTO THE MORNING…BUT THE DRIZZLE AND
FOG WILL GIVE WAY TO MORE SHOWERY PCPN AS THE COLD FRONT
APPROACHES FROM THE WEST. EXPECT THE WIDESPREAD SHOWERS TO BEGINN
AROUND 15Z/16Z…WITH IFR CIGS AND MVFR VSBYS OCCURING AT ALL THE
TAF SITES THROUGH THE REST OF THE TAF PERIOD ENDING AT 00Z FRIDAY.

A SOUTH BREEZE WILL CONTINUE AT ALL THE TAF SITES THROUGH THE PERIOD.
THE WIND WILL AVERAGE 10KTS AT ALL THE TAF SITES…WITH SOME
HIGHER GUSTS POSSIBLE…ESPECIALLY LATER ON THURSDAY.

A COLD FRONT WILL CROSS THE TAF SITES BUT NOT UNTIL THURSDAY NIGHT.
LOOK FOR MVFR AND POSSIBLY EVEN IFR CONDITIONS HEADING INTO
THURSDAY NIGHT.

OUTLOOK…

FRIDAY - SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA…SHSN.
SUNDAY: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHRA…SHSN.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.

&&

.FIRE WEATHER…
A SOAKING RAINFALL IS EXPECTED MAINLY THURSDAY AFTERNOON THROUGH
THURSDAY NIGHT. WE DID NOT ASSIGN A "WET FLAG" TO OUR NFDRS
SINCE THE BULK OF THE RAIN WILL NOT FALL UNTIL AFTER 100 PM
THURSDAY.

RAINFALL AMOUNTS SHOULD BE A QUARTER INCH OR MORE EVERYWHERE.

IT DRIES OUT FRIDAY WITH A NORTHWEST WIND 5- 15 MPH.

ANOTHER CLIPPER TYPE SYSTEM COULD BRING RAIN OR SNOW SHOWERS
SATURDAY NIGHT…ESPECIALLY NORTH AND WEST OF ALBANY. THERE
MIGHT BE SOME MINOR ACCUMULATIONS OF SNOW.

MUCH COLDER AIR WORKS IN ON GUSTY WINDS FOR THE LATER PORTION OF THE
WEEKEND.

&&

.HYDROLOGY…
A COLD FRONT WILL BRING A ROUND OF RAIN SHOWERS TO THE REGION
LATER THURSDAY INTO THURSDAY NIGHT.

THIS IS A PROGRESSIVE SYSTEM…SO IT WILL NOT LINGER TOO LONG.

IT DRIES OUT BY FRIDAY.

RAINFALL AMOUNTS LOOK TO BE HALF AN INCH TO AROUND AN INCH IN
THE VALLEYS…POSSIBLY UP TO TWO INCHES ACROSS THE HIGHER TERRAIN…
OF THE SOUTHERN GREENS AND BERKSHIRES.

THIS RAIN WILL PRODUCE WITHIN BANK RISES…MAYBE A FEW SPOTS
APPROACHING ACTION STAGE. NO FLOODING EXPECTED.

COOLER AND DRIER WEATHER WILL RETURN FRIDAY INTO THE FIRST HALF
OF THE WEEKEND. ANOTHER SYSTEM MAY BRING LIGHT PCPN IN THE FORM OF
RAIN/SNOW SHOWERS SATURDAY NIGHT INTO SUNDAY WITH LITTLE OR NO HYDROLOGICAL
IMPACTS.

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/GJM
NEAR TERM…HWJIV/GJM
SHORT TERM…HWJIV/KL
LONG TERM…WASULA
AVIATION…GJM
FIRE WEATHER…HWJIV
HYDROLOGY…HWJIV/KL/WASULA

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