000
FXUS61 KALY 271742
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1242 PM EST MON FEB 27 2012
.SYNOPSIS…
A CLIPPER LOW WILL APPROACH THE REGION FROM THE GREAT
LAKES AND SOUTHEASTERN ONTARIO THIS AFTERNOON. THE LOW WILL MOVE
ALONG THE SAINT LAWRENCE RIVER VALLEY TO NORTHERN NEW ENGLAND BY
TONIGHT…BRINGING SOME RAIN AND SNOW SHOWERS TO EASTERN NEW YORK
AND WESTERN NEW ENGLAND. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM
THE GREAT LAKES REGION…AND SOUTHEASTERN CANADA WITH SEASONABLY
COLD AND DRY WEATHER FOR TUESDAY…WHILE A COMPLEX LOW PRESSURE
SYSTEM WILL APPROACH FROM THE UPPER MISSISSIPPI VALLEY…AND
WESTERN GREAT LAKES REGION FOR THE MID WEEK WITH SOME SNOW AND
POTENTIALLY MIXED PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/…
— Changed Discussion —
AS OF 1241 PM EST…A QUICK MOVING SHORTWAVE CONTINUES TO PUSH ITS
WAY ACROSS THE GREAT LAKES WITH A SFC REFLECTION OF THE CLIPPER
SYSTEM MOVING ACROSS SOUTHERN CANADA. RECENT MOSAIC RADAR RETURNS
SHOW SOME PRECIP ACROSS LAKE ONTARIO AND THE ST LAWRENCE
VALLEY…AND THE LATEST 12 UTC NAM/GFS SHOWS THAT THE MAJORITY OF
THIS PRECIP SHOULD REMAIN TO THE NORTH OF THE REGION FOR THE EARLY
TO MID AFTN HOURS. HOWEVER…BY THE LATE AFTN…A FEW RAIN/SNOW
SHOWERS WILL BE POSSIBLE…MAINLY FOR AREAS TO THE NORTH OF
I-90…AS THE STORM/S COLD FRONT MOVES THROUGH THE AREA…AND
WESTERLY FLOW BEHIND THE BOUNDARY ALLOWS SOME UPSLOPE ALONG
WESTERN FACING SLOPES OF THE ADIRONDACKS AND GREEN MOUNTAINS.
TEMPS LOOK GENERALLY ON TRACK FOR THE EARLY TO MID AFTN…WITH
40S THIS AFTN FOR VALLEY AREAS…AND 30S ACROSS THE HIGHER
TERRAIN. TEMPS WILL SLOWLY FALL OFF LATER THIS AFTN AND INTO THIS
EVENING…BUT SHOULD REMAIN ABOVE FREEZING IN MOST VALLEY AREAS TO
KEEP ANY SPOTTY PRECIP AS LIQUID.
— End Changed Discussion —
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/…
— Changed Discussion —
TONIGHT…THE COLD FRONT TO THE CLIPPER MOVES ACROSS THE REGION
WITH SOME WESTERLY UPSLOPE SNOW SHOWERS FOR THE SOUTHERN
ADIRONDACKS…SOUTHERN GREEN MOUNTAINS…AND NRN BERKSHIRES. TOTAL
SNOW ACCUMULATIONS ACROSS THE SOUTHERN ADIRONDACKS WILL BE IN THE
1 TO 2 INCH RANGE WITH UP TO AN INCH OR SO OVER SOUTHERN
GREENS…AND NRN BERKSHIRES. LITTLE OR NO SNOW ACCUMULATION IS
EXPECTED IN THE VALLEY LOCATIONS AS THE PRECIP SHOULD MAINLY BE
RAIN BEFORE TEMPS COOL TO BELOW FREEZING AND THE PRECIP SHUTS OFF.
STRONG COLD ADVECTION OCCURS IN THE WAKE OF THE BOUNDARY WITH
TEMPS FALLING BACK INTO THE THE MID 20S TO NEAR 30F OVER MOST OF
THE FORECAST AREA…WITH SOME TEENS TO LOWER 20S OVER THE SRN
DACKS…AND SRN GREENS.
TUESDAY-TUESDAY NIGHT…A LARGE DOME OF CANADIAN HIGH PRESSURE
BUILDS IN FROM SOUTHEASTERN ONTARIO AND THE GREAT LAKES REGION
WITH MAINLY CLEAR AND COLD CONDITIONS DURING THE DAY. H850 TEMPS
FALL BACK TO -8C TO -11C FROM KALB NORTH…AND -3C TO -8C SOUTH
AND EAST. DEEP MIXING AND BRISK CONDITIONS SHOULD ALLOW HIGHS TO
BE IN THE U20S TO M30S OVER THE MTNS…AND U30S TO L40S IN THE
VALLEYS. A STRONG UPPER LEVEL TROUGH EJECTS OUT OF THE SRN-CNTRL
ROCKIES TUE NIGHT INTO THE CNTRL PLAINS. THE WARM FRONT TO THIS
DEVELOPING STORM SYSTEM APPROACHES FROM THE MIDWEST AND OHIO
VALLEY. MID AND HIGH CLOUDS QUICKLY INCREASE FROM THE SOUTH AND
WEST OVERNIGHT. LOW-LEVEL SHALLOW…COLD…DRY AIR WILL BE FUNNELING
INTO THE REGION…AS THE CANADIAN SFC ANTICYCLONE REMAINS OVER SE
QUEBEC AND NRN NEW ENGLAND BY DAYBREAK ON WED.
WED-WED NIGHT…THE GUIDANCE IS IN AGREEMENT THAT THE LOW LEVEL
BAROCLINIC ZONE WILL STRENGTHEN OVER PA INTO NY WEDNESDAY MORNING
FOR SOME OVER RUNNING PCPN TO BEGIN. THE DEPTH OF THE COLD AIR IN
THE LOW LEVELS COUPLED WITH THE WET BULB EFFECT WILL ALLOW SNOW TO
OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST IN THE LATE
MORNING THROUGH THE AFTERNOON. THE ISENTROPIC LIFT STRENGTHENS WITH
THE PRIMARY LOW MOVING INTO THE CNTRL GREAT LAKES REGION BY EARLY
WED EVENING. BAGGINESS IN THE SFC ISOBARS INDICATES SECONDARY
COASTAL LOW DEVELOPMENT MAY OCCUR WEDNESDAY EVENING NEAR THE MID
ATLANTIC REGION. THE ECMWF PROFILES ARE BELOW 0C WED AND WED NIGHT
AT H925…AND H850 OVER THE ENTIRE FCST AREA ! THE NAM IS COLD FOR
PREDOMINANTLY A SNOW PTYPE. CRITICAL THICKNESSES SUPPORT SOME
SLEET. THE 18Z GEFS PLUME FOR ALBANY WAS MOSTLY SNOW /MAJORITY OF
PLUME MEMBERS/ WITH A FEW FRZA/IP. THE NEWEST PLUME HAS A BIT MORE
FZRAS MEMBERS BUT STILL MORE RAIN AND SNOW. THE LATEST SREF
GRAPHICS INDICATE LITTLE OR NO PROBS OF FREEZING RAIN…EXCEPT
OVER THE EXTREME SOUTH. THE HPC WINTER GUIDANCE INDICATES A LITTLE
BIT OF FREEZING RAIN FOR THE SRN 3 COUNTIES WED NIGHT. WE STUCK
WITH THE SNOW AND SLEET SCENARIO FOR THE FCST AREA NOW WITH A
LITTLE BIT OF LIQUID RAIN. THE BUFKIT MODEL SOUNDINGS INDICATE
MOSTLY SNOW AND SLEET FOR THE REGION. WE COULD BE LOOKING AT A
MODERATE TO LOCALLY HVY SNOW EVENT. THE SLEET COULD CUT DOWN
ACCUMULATIONS. AGAIN…THE GUIDANCE HAS BEEN VARIABLE WITH THE
THERMAL PROFILES. THIS CYCLE OF THE ECMWF…NAM…SREFS AND CAN
GGEM FAVOR A WINTRY PTYPE OF SNOW AND SLEET. THE GFS HAS BEEN THE
WARMER ONE THIS CYCLE. WE WILL CONTINUE TO HIGHLIGHT THIS EVENT IN
THE HWO. THERE CONTINUES TO BE A LOT OF UNCERTAINTY IN THE THERMAL
PROFILES AMONG THE ASSORTED GUIDANCE THE PAST FEW RUNS WHICH WILL IMPACT
SIGNIFICANTLY THE PTYPE AND AMOUNTS.
— End Changed Discussion —
&&
.LONG TERM /THURSDAY THROUGH MONDAY/…
ACTIVE WEATHER PATTERN EXPECTED TO CONTINUE FOR MUCH OF THE LONG
TERM PERIOD AS A DOUBLE BARREL LOW EXPECTED TO IMPACT WEATHER THROUGH
THURSDAY…FOLLOWED BY A RIDGE OF HIGH PRESSURE ON FRIDAY. OVER THE
WEEKEND…A MID LEVEL TROUGH IS EXPECTED TO MOVE EAST FROM THE UPPER
GREAT LAKES INTO SOUTHEAST CANADA AND THE NORTHEAST US…AS THE
SURFACE LOW TRACKS THROUGH THE UPPER GREAT LAKES AND SOUTHERN QUEBEC
FIRST LIFTING A WARM FRONT INTO OUR REGION ON SATURDAY AND A COLD
FRONT THROUGH OUR REGION SATURDAY NIGHT.
FOR THURSDAY…A GREAT DEAL OF UNCERTAINTY EXISTS WITH YET ANOTHER
DOUBLE BARREL SYSTEM IMPACTING FA. GGEM…GFS AND ECMWF ALL HAVE A
PRIMARY LOW IN THE EASTERN OR CENTRAL GREAT LAKES THURSDAY MORNING
WITH A SECONDARY LOW NEAR OR SOUTHEAST OF LONG ISLAND. THE GFS HAS
THE SECONDARY LOW DEEPEST AND TRACKS IT CLOSEST TO LONG
ISLAND…WHILE THE ECMWF IS FARTHEST SOUTH AND WEAKEST. THE GFS IS
ALSO FARTHEST EAST AND DEEPEST WITH THE PRIMARY LOW OVER LAKE
ONTARIO. THE GEFS PLUME DIAGRAM AT KALB INDICATES PTYPE COULD BE
ALMOST ANYTHING…SIMILAR TO WHAT OCCURRED LAST FRIDAY. FOR NOW AND
SINCE THIS IS DAY 4 WILL KEEP PTYPES CONFINED TO RAIN OR SNOW.
EXPECT HIGHS ON THURSDAY TO GENERALLY BE IN THE 30S.
THURSDAY NIGHT AND FRIDAY EXPECT A LULL IN THE PCPN WITH SFC HIGH
PRESSURE BRIEFLY BUILDING INTO FA. A WEAK SECONDARY TROUGH MAY KEEP
SOME SNOW SHOWERS GOING THURSDAY NIGHT…SO WILL KEEP CHANCE POPS IN
THE FORECAST…OTHERWISE FRIDAY LOOKS MAINLY DRY. EXPECT LOWS
THURSDAY NIGHT TO BE IN THE MID TEENS TO MID 20S WITH HIGHS ON
FRIDAY IN THE MID 30S TO LOWER 40S.
FRIDAY NIGHT INTO SATURDAY NIGHT…BOTH GFS AND ECMWF SHOW A DEEP
UPPER LOW AND SURFACE LOW LIFTING NORTHEAST FROM THE UPPER GREAT
LAKES PASSING SOUTH OF JAMES BAY. THE SYSTEM WILL BRING MORE PCPN TO
THE FA WITH THE GEFS PLUMES INDICATING A MAINLY RAIN TO SNOW
SCENARIO…ALTHOUGH IT MAY BE INITIALLY COLD ENOUGH FOR SOME LIGHT
SNOW AT THE ONSET WHEN PCPN ARRIVES LATER FRIDAY NIGHT. HOWEVER…AS
STRONG WARM AIR ADVECTION IS EXPECTED WITH A WARM FRONT LIFTING
NORTH INTO THE REGION ON SATURDAY…A QUICK CHANGEOVER TO RAIN IS
LIKELY…BEFORE CHANGING BACK TO SNOW SATURDAY NIGHT IN THE
WAKE OF THE COLD FRONT WHICH IS EXPECTED TO BE WELL EAST OF THE FA
BY LATE SATURDAY NIGHT. EXPECT LOWS FRIDAY NIGHT IN THE MID 20S TO
LOWER 30S WITH HIGHS ON SATURDAY IN THE UPPER 30S TO UPPER 40S AND
LOWS SATURDAY NIGHT IN THE 20S TO LOW TO MID 30S.
SUNDAY AT THIS POINT LOOKS MAINLY DRY WITH SOME SCATTERED LAKE
EFFECT SNOW SHOWERS IMPACTING MAINLY THE WESTERN HALF OF THE FA WITH
HIGHS IN THE 30S EXCEPT LOW TO MID 40S IN THE HUDSON VALLEY AND FAR
SOUTHEAST PORTION OF FA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/…
MIDLEVEL CLOUDS HAVE SPREAD ACROSS THE REGION…AND VFR CEILINGS
SHOULD CONTINUE THROUGH TONIGHT. CEILINGS COULD FLIRT WITH MVFR
LATE THIS AFTERNOON AND EVENING IF A BRIEF SHOWER OR SNOW SHOWER
WERE TO OCCUR AT KGFL AND KALB. NOT ENOUGH COVERAGE OF RAIN AND
SNOW SHOWERS TO ACKNOWLEDGE IN TEMPO GROUP SO JUST VCSH AROUND
22Z-02Z.
COLD FRONT TRACKS THROUGH LATER THIS EVENING AND OVERNIGHT AND
CEILINGS SHOULD BREAK UP WITH VFR CONDITIONS CONTINUING THROUGH
TOMRROW MORNING.
SOUTH TO SOUTHWEST WINDS THIS AFTERNOON AT AROUND 10KT WITH SOME
GUSTS TO 20 KT AT KALB AND KPOU. WINDS SHIFT TO NORTH AND NORTHWEST
TONIGHT AT 50 TO 10 KT…THEN INCREASE TO 10 TO 15 KT TOMORROW
MORNING.
OUTLOOK…
TUE…VFR…NO SIG WX.
TUE NGT-THU…VFR/MVFR…CIG…CHC IFR IN -SN/-RA.
THU NGT-FRI…VFR…NO SIG WX.
SAT…CHC MVFR/IFR IN -SHRA/-SHSN.
&&
.HYDROLOGY…
NO HYDRO WIDESPREAD HYDRO RELATED PROBLEMS ARE EXPECTED FOR THE
NEXT 5 DAYS ON THE MAIN STEM RIVERS. SOME HYDRO GAGES ARE STILL
BEING IMPACTED BY ICE FROM THE MOHAWK RIVER VALLEY IN THE ALBANY
HYDRO SERVICE AREA NORTHWARD.
A CLIPPER WILL BRING SOME LIGHT SNOW AND RAIN SHOWERS TO THE HSA
FROM THE CAPITAL REGION NORTH TODAY INTO TONIGHT. TOTAL QPF WILL
GENERALLY BE UNDER TWO TENTHS OF AN INCH.
A MODERATE TO HEAVY PRECIPITATION EVENT IS POSSIBLE WEDNESDAY INTO
THURSDAY WITH TOTAL QPF IN THE ONE THIRD TO ONE INCH RANGE. A
LARGE PORTION OF THE PRECIPITATION MAY FALL AS SNOW AND
SLEET…MIXING WITH SOME RAIN IN THE SOUTHERN REACHES OF THE HSA.
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…NAS/WASULA
NEAR TERM…FRUGIS
SHORT TERM…WASULA/FRUGIS
LONG TERM…11
AVIATION…NAS
HYDROLOGY…WASULA
