000
FXUS61 KALY 151149
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
649 AM EST FRI FEB 15 2013
.SYNOPSIS…
A CLIPPER LOW WILL PASS NORTH OF THE REGION TODAY…AND
ITS WEAK COLD FRONT WILL MOVE THROUGH IN THE AFTERNOON. TONIGHT
INTO SATURDAY…LOW PRESSURE WILL MOVE FROM THE MID ATLANTIC COAST
TO WELL SOUTH AND EAST OF LONG ISLAND BRINGING A LIGHT SNOWFALL FROM
THE CAPITAL REGION SOUTH AND EAST. A POWERFUL STORM WILL FORM EAST
OF THE GULF OF MAINE BRINGING BLUSTERY AND COLD CONDITIONS FOR
SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/…
AS OF 645 AM EST…CLIPPER LOW CONTINUES TO MOVE ACROSS SW QUEBEC
THIS MORNING. SOME SCT SNOW SHOWERS CONTINUE AHEAD OF THE COLD FRONT
OVER THE SRN DACKS REGION. LIGHT SNOW ACCUMULATIONS WILL BE EXPECTED
OVER THE SRN DACKS…SRN GREENS…AND THE LAKE GEORGE SARATOGA
REGION WITH A COATING TO A HALF AN INCH.
A BROAD UPPER LEVEL TROUGH WILL CONTINUE TO BE OVER THE NRN
PLAINS…UPPER MIDWEST…GREAT LAKES REGION…AND THE NORTHEAST
TODAY. NY AND NEW ENGLAND WILL BE UNDER THE INFLUENCE OF LOW TO
MID LEVEL SOUTHWESTERLY FLOW. MILD TEMPS ARE EXPECTED WITH HIGHS A
SOLID 10 DEGREES ABOVE NORMAL…AS H850 TEMPS WILL BE IN THE -1C
TO -6C RANGE FROM THE CAPITAL REGION SOUTH. EXPECT HIGHS TO BE IN
THE MID AND UPPER 40S FROM THE TRI CITIES SOUTH AND EAST…EXCEPT
SOME U30S TO L40S OVER THE HIGHER TERRAIN. NORTH AND WEST OF THE
CAPITAL REGION 30S TO L40S WILL BE COMMON.
A WEAK COLD FRONT WILL PASS THROUGH DURING THE EARLY TO MID
AFTERNOON WITH VERY WEAK CONVERGENCE ASSOCIATED WITH IT. A SLIGHT
TO LOW CHC OF SNOW SHOWERS WAS KEPT IN FOR THE WRN DACKS DUE TO
THE OROGRAPHIC WESTERLY UPSLOPE POTENTIAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/…
TONIGHT…THE WEAK COLD FRONT GETS HUNG UP A BIT SOUTH OF THE FCST
AREA…AS A SHORT-WAVE APPROACHES FROM THE VIRGINIAS. THIS
DISTURBANCE WILL RIDE ALONG OR NEAR THE FRONTAL BOUNDARY…AND
WE EXPECT SOME LIGHT SNOW TO BREAK OUT FROM THE CAPITAL REGION
SOUTH AND EAST. THE NAM WAS BIG ON THIS FEATURE FOR DAYS…AND NOW
IT HAS LITTLE OR NOTHING. THE GFS AND ECMWF WERE USED HERE…AND
LIGHT SNOW ACCUMS OF 1 TO 2 INCHES ARE POSSIBLE OVER THE ERN
CATSKILLS…MID HUDSON VALLEY…NW CT. THERE WILL LIKELY BE A WEAK
LAKE EFFECT CONNECTION OFF ONTARIO TOO. SOME CHC POPS WERE USED
FOR THE WRN DACKS AND WRN MOHAWK VALLEY WITH LIGHT SNOW
ACCUMULATIONS. LOWS WILL BE IN THE TEENS AND SINGLE DIGITS NORTH
OF THE CAPITAL REGION…AND GENERALLY LOWER TO MID 20S TO THE
SOUTH AND EAST.
SATURDAY…A DIGGING HIGH AMPLITUDE LONG WAVE TROUGH SETS UP OVER
THE ERN THIRD OF THE LOWER 48S. SEVERAL IMPULSES ARE MOVING
THROUGH THE TROUGH WITH A LOW FORMING NEAR THE CAROLINAS. THE BEST
LOW-LEVEL BAROCLINIC ZONE REMAINS OFF THE MID ATLANTIC AND NEW
ENGLAND COAST. THE LIGHT SNOW WILL DIMINISH SATURDAY MORNING BASED
ON THE MAJORITY OF THE GUIDANCE. THE LOW AND MID LEVEL FLOWS VEERS
TO NORTHWEST WHICH SHOULD MAKE ANY LAKE
CONNECTION…MULTIBANDS…AND SLIGHT OR LOW CHANCE POPS WERE
INCLUDED FOR ISOLD-SCT SNOW SHOWERS CLIPPING THE WRN MOHAWK
VALLEY…AND THE ERN CATSKILLS. LOW AND MID LEVEL COLD ADVECTION
WILL CONTINUE WITH MAX TEMPS CLOSER TO NORMALS FOR MID-FEB. SOME
LIGHT OVERRUNNING SNOWFALL MAY SNEAK INTO THE SOUTHERN ZONES
SHORTLY NIGHT FALL.
SATURDAY NIGHT INTO SUNDAY…THE LATEST GFS HAS ONE INTENSE AND
DEEP OCEANIC CYCLONE THIS CYCLE. SIGNIFICANT CYCLOGENESIS OCCURS
AS A 1001 HPA LOW AT 00Z/SUN WELL EAST OF HATTERAS…DEEPENS TO
981 HPA A FEW HUNDRED MILES SE OF CAPE COD AT 12Z/SUN…TO 960 HPA
SOUTH OF NOVA SCOTIA AT 00Z/MON. THIS WOULD BE QUITE THE INTENSE
CYCLONE BOMB ! THIS SOLUTION IS ONE OF THE MOST INTENSE IN TERMS
OF GEFS MEMBERS. THE ECWMF DOES NOT INTENSIFY THE STORM AS
MUCH…BUT STILL A FORMIDABLE OCEANIC CYCLONE TRACKS SIMILAR TO
THE GFS. OUTER DEFORMATION SNOWFALL IS EXPECTED FROM THE CAPITAL
REGION EASTWARD. THE GREATEST IMPACT LOOKS LIKE THE TACONICS EAST
TO WRN NEW ENGLAND. GENERALLY 1-3" OF SNOW IS FORECAST /PERHAPS
ISOLD 4" AMOUNTS OVER THE BERKS/. THE CAPITAL REGION/HUDSON VALLEY
WESTWARD WILL LIKELY HAVE A DUSTING TO AN INCH OR SO. THE SNOW
SHOULD DIMINISH SUNDAY MORNING. THE SFC/925 HPA/850 HPA WINDS WILL
CRANK UP…AND A BLUSTERY AND COLD DAY IS IN STORE FOR THE FCST
AREA. MAX TEMPS WILL BE IN THE LOWER TO M20S IN THE HUDSON RIVER
VALLEY…SRN TACONICS…NW CT…AND CT RIVER VALLEY…EXPECT TEENS
ELSEWHERE. THE WINDS WILL BE FROM THE N/NW AT 15 TO 25 MPH WITH
GUSTS 35 TO 40 MPH /A FEW ISOLD 45 MPH GUSTS WILL BE POSSIBLE OVER
THE NRN CATSKILLS…AND BERKS/. SOME SHALLOW MULTIBANDS MAY SCRAPE
THE WRN MOHAWK VALLEY AND NRN CATSKILLS WITH LIGHT SNOW ACCUMS.
WIND CHILL VALUES MAY FLIRT WITH ADVISORY CRITERIA OVER THE SRN
DACKS.
SUNDAY NIGHT…THE CORE OF THE COLDEST AIR SHIFTS EAST BY DAYBREAK.
HOWEVER…LOWS OF ZERO TO 10 BELOW OVER THE SRN DACKS…AND SRN
GREENS WITH WINDS OF 5 TO 15 MPH ARE EXPECTED TO PRODUCE WIND
CHILLS OF 20 TO 25 DEG BELOW ZERO AT THIS TIME. THESE WIND CHILLS
WILL BE MENTIONED IN THE HWO…THAT AN ADVISORY MAY BE NEEDED
LATER IN TIME. ELSEWHERE LOWS WILL BE IN THE SINGLE DIGITS TO
LOWER 10S. THE WINDS WILL GRADUALLY DIMINISH WITH HIGH PRESSURE
BUILDING IN OVER THE EAST COAST. A VERY COLD MORNING IS
ANTICIPATED FOR THE HOLIDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/…
OVERALL THE MODEL GUIDANCE IS IN GOOD AGREEMENT WITH LONGWAVE
PATTERN THROUGH THE PERIOD MAINTAINING GOOD RUN-TO-RUN CONTINUITY.
THE STACKED LOW PRESSURE SYSTEM WILL AWAY FROM THE REGION AND
RIDGING WILL BUILD IN ON MONDAY WHICH SHOULD DOMINATE OUR WEATHER
THROUGH MONDAY NIGHT. THE CYCLONIC FLOW ON THE BACK SIDE OF
DEPARTING LOW WILL RESULT IN A TIGHT PRESSURE GRADIENT ACROSS THE
REGION ESPECIALLY EARLY IN THE DAY MONDAY. IT WILL BE ANOTHER COLD
AND BLUSTERY DAY DESPITE SUNSHINE…BUT NOT AS PRONOUNCED AS SUNDAY.
WE ARE ANTICIPATING WIND CHILL VALUES BELOW ZERO ACROSS THE ENTIRE
FORECAST AREA TO START THE DAY.
OUR NEXT WEATHER SYSTEM WILL ORIGINATE IN THE NORTHERN STREAM. A LOW
PRESSURE SYSTEM OVER THE PLAINS IS MODELED TO TRACK TO OVER THE
GREAT LAKES REGION. ADDITIONAL SHORT WAVE ENERGY WILL ENTER THE
PICTURE RESULTING IN THE DEVELOPMENT OF A CLOSED OFF BY TUESDAY
WHICH SHOULD THEN MOVE EASTWARD ALONG THE UNITED STATES/CANADIAN
BORDER THROUGH MID WEEK. THE MODELS INDICATE ENERGY SHIFTS TO THE
EAST TO OVER NORTHERN NEW ENGLAND WEDNESDAY WITH SURFACE LOW
DEVELOPMENT WHICH EVENTUALLY BECOMES THE PRIMARY LOW.
WITH THE MAIN LOW EXPECTED TO PASS TO OUR NORTH…TEMPERATURES WILL
MODERATE TO ABOVE NORMAL TUESDAY WITH A SOUTHERLY FLOW ACROSS THE
REGION. PRECIPITATION INITIALLY IS EXPECTED TO START OUT AS SNOW
THEN TRANSITION TO RAIN FOR A PERIOD ACROSS MUCH OF THE FORECAST
AREA ESPECIALLY IN THE VALLEYS.
MORE SEASONABLE TEMPERATURES ARE EXPECTED ON WEDNESDAY AS THE FLOW
SHIFTS TO THE WEST AND INCREASES AS THE PRESSURE GRADIENT TIGHTS
ACROSS THE REGION AS THE SECONDARY LOW DEEPENS AND BECOMES THE
PRIMARY LOW. WOULD EXPECT SOME LAKE ENHANCED AND UPSLOPE SNOW
SHOWERS.
HIGH PRESSURE AT THE SURFACE AND ALOFT IS EXPECTED TO BUILD IN FOR
THURSDAY BETWEEN WEATHER SYSTEMS.
A SOUTHERN STREAM SYSTEM IS EXPECTED TO DEVELOP MID WEEK OVER THE
SOUTHWESTERN UNITED STATES THEN HEAD EASTWARD INTO THE CENTRAL AND
SOUTHERN PLAINS. AT THIS TIME…IT APPEARS THIS SYSTEM WOULD IMPACT
OUR NECK OF THE WOODS AS WE HEAD INTO THE NEXT WEEKEND.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/…
WEAK HIGH PRESSURE WILL BRIEFLY BUILD IN TODAY. A CLIPPER LOW
WILL APPROACH FROM THE GREAT LAKES REGION TONIGHT WITH SOME LIGHT
SNOW OR SNOW SHOWERS NORTH AND WEST OF THE CAPITAL REGION.
SOME RADIATIONAL FOG DEVELOPED AT KPOU WITH VLIFR/LIFR CONDITIONS
LINGERING. A TEMPO WAS USED THE NEXT FEW HOURS BEFORE CONDITIONS
IMPROVE TO VFR. EXPECT VFR CONDITIONS PRIOR TO 06Z/FRI AT
KALB/KPSF/KGFL BEFORE CLOUDS THICKEN AND LOWER AHEAD OF A CLIPPER
LOW IN THE LATE AFTERNOON AND EARLY EVENING. SOME LIGHT SNOW OR
SNOW SHOWERS MAY GRAZE KGFL WITH AT LEAST MVFR CONDITIONS. A VCSH
GROUP WAS USED AT KALB.
THE WINDS WILL BE LIGHT TO CALM THIS MORNING. EXPECT LIGHT SOUTH TO
WEST WINDS AT AROUND 5 KTS DURING THE AFTERNOON INTO THE NIGHTTIME
PERIOD.
OUTLOOK…
FRI…MAINLY VFR. SLIGHT CHC-CHC -SHSN/-SHRA FROM KALB NORTH.
FRI NIGHT…VFR…SLIGHT CHC OF -SHSNS.
SAT…VFR/MVFR. CHC -SHSN.
SUN-MON…VFR. NO SIG WX
&&
.HYDROLOGY…
NO HYDROLOGY PROBLEMS ARE EXPECTED OVER THE NEXT FEW DAYS. SNOW
MELT WILL CONTINUE TO BE GRADUAL THROUGH SATURDAY WITH ABOVE
FREEZING TEMPERATURES DURING THE DAY…AND BELOW FREEZING AT
NIGHT. TEMPERATURES WILL BECOME COLDER FOR THE 2ND HALF OF THE
WEEKEND SLOWING…AND EVEN ENDING THE SNOWMELT.
THE PREDOMINANT PTYPE TODAY INTO THE MID WEEK WILL BE SNOW. THE
SYSTEMS DURING THAT TIME FRAME ARE EXPECTED TO ONLY PRODUCE LIGHT
SNOW AMOUNTS. THEREFORE…NO IMPACTS ARE EXPECTED ON THE ALY HSA
WATERWAYS.
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…WASULA
NEAR TERM…WASULA
SHORT TERM…WASULA
LONG TERM…IAA
AVIATION…IAA
HYDROLOGY…NAS/WASULA
