000
FXUS61 KALY 201121
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
621 AM EST THU NOV 20 2008
.SYNOPSIS...
THE COLD WEATHER PATTERN THE REGION HAS HAD LATELY IS EXPECTED TO
CONTINUE WELL INTO NEXT WEEK. A WEAK CLIPPER TYPE SYSTEM WILL MOVE
THROUGH THE REGION TODAY. THIS SYSTEM HAS VERY LITTLE MOISTURE
ASSOCIATED WITH IT...BUT IT WILL STILL PRODUCE SOME LIGHT SNOW
SHOWERS OR FLURRIES...MAINLY TO THE SOUTH AND WEST OF THE CAPITAL
DISTRICT. OTHERWISE...OCCASIONAL LAKE EFFECT SNOW SHOWERS ARE
EXPECTED DOWNWIND OF LAKE ONTARIO FROM LATE TONIGHT INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
RADAR/STLT DATA/LOOPS INDICATE THAT MOST OF THE LIGHT SNOW/FLURRIES
ASSOCIATED WITH THE CLIPPER LIKE SYSTEM MOVING THROUGH THE REGION
WILL STAY OVER THE SOUTHWEST AND SOUTHERN PART OF THE FORECAST AREA
TODAY...AND HAVE FORECAST THE HIGHEST POPS FOR THIS REGION (30-40
PERCENT). FOR MOST OF THE REST OF THE FORECAST AREA HAVE FORECAST
ONLY SLIGHT CHANCE POPS.
WITH 850 MB TEMPS NOT EXPECTED TO GET ABOVE -10 DEG CELSIUS AND LOTS
OF CLOUD COVER ACROSS THE REGION...TEMPS WILL REMAIN QUITE COLD WITH
HIGHS ONLY IN THE MID 20S TO MID 30S.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
THE CLIPPER LIKE SYSTEM WILL USHER IN EVEN COLDER AIR...WITH 850 MB
TEMPS ACROSS THE REGION FRIDAY AND SATURDAY IN THE -12 TO -16 DEG
CELSIUS RANGE. THAT SHOULD RESULT IN HIGHS GENERALLY IN THE LOW 20S
TO LOW 30S ACROSS THE REGION BOTH DAYS. NIGHTIME LOWS WILL BE MAINLY
IN THE TEENS. GUSTY WINDS...ESPECIALLY ON SATURDAY WHEN WIND GUSTS
COULD REACH AROUND 35 MPH...WILL MAKE IT FEEL VERY WINTERLIKE ACROSS
THE REGION DURING THIS PERIOD.
WITH THE CLIPPER LIKE SYSTEM MOVING THROUGH THE REGION TODAY...
AND THE DEEPENING UPPER LEVEL TROF AFFECTING THE REGION THROUGH
SATURDAY...HAVE KEPT SLIGHT OR LOW CHANCE POPS IN MOST AREAS THROUGH
SATURDAY. HOWEVER...THE HIGHEST POPS HAVE BEEN FORECAST FOR THE
SOUTHWEST PART OF THE REGION FROM SOUTHERN HERKIMER COUNTY...INTO
SCHOHARIE COUNTY AND THEN INTO THE SOUTHEAST CATSKILLS DUE TO
EXPECTED LAKE EFFECT ACTIVITY WHICH SHOULD LINE UP IN A 310-320
DEGREE ORIENTATION. THE LAKE EFFECT ACTIVITY WILL PEAK ON
FRIDAY...SO HAVE FORECAST THE HIGHEST POPS (UP TO AROUND 50 PERCENT)
FOR THESE AREAS AT THAT TIME.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A RIDGE OF HIGH PRESSURE WILL BUILD IN SAT NIGHT INTO SUN...BRINGING
DRY CONDITIONS. HOWEVER...TEMPS WILL STILL BE QUITE CHILLY AS THE
COLDEST CORE OF AIR ALOFT WILL NOT RETREAT UNTIL LATER SUN. SO MAX
TEMPS WILL STILL BE IN THE 30S IN THE VALLEYS AND 20S IN THE
MOUNTAINS. SUN NIGHT THE RIDGE MOVES EAST OF THE AREA...AS A WARM
FRONT APPROACHES FROM THE GREAT LAKES. SOME LIGHT SNOW POSSIBLE WELL
NORTH AND WEST OF ALBANY ASSOC WITH AN INITIAL SHOT OF WARM
ADVECTION.
ON MON...WIDESPREAD BUT MAINLY LIGHT QPF IS POSSIBLE. A CUT-OFF LOW
WILL ADVANCE EASTWARD ACROSS THE GREAT LAKES AND MORE SUBSTANTIAL
ISENTROPIC LIFT COMMENCES OUT AHEAD OF THE LOW ACROSS OUR REGION.
GFS/ECMWF STILL DIFFER WITH POSITION OF THE UPPER LOW AND SURFACE
CYCLONE...WITH THE ECMWF DEPICTING A MORE SOUTHERLY TRACK. THIS HAS
GREATER IMPLICATIONS FOR THE TUE/WED TIME FRAME...BUT FOR MON BOTH
MODEL SOLUTIONS STILL RESULT IN A PERIOD OF WIDESPREAD LIGHT SNOW
WITH MAINLY MINOR ACCUMULATIONS. SOME RAIN MAY MIX IN THE VALLEYS
DURING THE AFTERNOON AS THE BOUNDARY LAYER WARMS SOMEWHAT.
MON NIGHT INTO TUE IS WHEN MUCH MORE UNCERTAINTY DEVELOPS AS TO THE
EVOLUTION OF THE CUT-OFF LOW AS IT MOVES EAST...WHICH HAS MAJOR
IMPLICATIONS FOR THE SENSIBLE WEATHER ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND. THE GFS AND MOST OF THE GEFS ENSEMBLE MEMBERS
TRACK THE CUT-OFF LOW RIGHT OVER EASTERN NY AS IS DEEPENS...WITH
COASTAL DEVELOPMENT ACROSS FAR EASTERN MASS AND MAINE. THIS SCENARIO
WOULD KEEP SIGNIFICANT PRECIP AWAY FROM US WITH JUST SCATTERED SNOW
SHOWERS AND SOME LAKE EFFECT BY MID WEEK. THE ECMWF CUTS OFF THE
UPPER LOW TO OUR SOUTH OVER THE MID ATLANTIC REGION WHICH RESULTS IN
COASTAL DEVELOPMENT NEAR NEW JERSEY...WITH THE LOW GRADUALLY LIFTING
NORTHWARD INTO SOUTHERN NEW ENGLAND ON WED AND ACTUALLY RETROGRADING
INTO NEW YORK BY THUR. THIS SCENARIO COULD POTENTIALLY RESULT IN
SIGNIFICANT WINTRY PRECIP. WILL KEEP THINGS SOMEWHAT SIMPLE FOR
NOW AND MENTION MAINLY CHANCE POPS THROUGH TUE NIGHT AND KEEP PTYPE
SNOW/RAIN BASED ON ELEVATION AND DIURNAL CYCLE. OVERALL..LESS
CONFIDENCE THAN NORMAL FOR THIS FORECAST PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A CLIPPER TYPE SYSTEM DIVING SOUTHEAST ACROSS THE EASTERN GREAT
LAKES EARLY THIS MORNING WILL WEAKEN AS IT MOVES INTO CENTRAL NY/PA
LATER THIS MORNING INTO THE AFTERNOON. THIS WILL RESULT IN CIGS
LOWERING AT THE TAF SITES...WITH SOME FLURRIES POSSIBLE AT
KALB/KPOU. GENERALLY VFR CONDITIONS SHOULD PREVAIL...ALTHOUGH SOME
BRIEF MVFR VSBY/CIGS POSSIBLE ESPECIALLY AT KPOU. OMITTED FROM TAFS
DUE TO LOW PROBABILITY OF OCCURRENCE. FLURRIES NOT EXPECTED TO
REACH AREAS FARTHER TO THE NORTH NEAR KGFL. FLURRIES SHOULD END BY
EARLY AFTERNOON. THERE SHOULD BE A BRIEF PERIOD OF CLEARING FROM
LATE AFTERNOON INTO THE EVENING ASSOC WITH SUBSIDENCE BEHIND THE
CLIPPER. HOWEVER...CLOUDS SHOULD INCREASE AGAIN BY FRI MORNING AS
ANOTHER TROF APPROACHES FROM THE GREAT LAKES. WINDS WILL BE VARIABLE
LESS THAN 5 KTS THROUGH MUCH OF THE MORNING...THEN BECOMING
NORTHWEST AROUND 7-10 KT THIS AFTERNOON.
OUTLOOK...
FRI-SAT...VFR...ISOLD -SHSN.
SUN...VFR. NO SIG WX.
MON...MVFR/IFR...CHC -SN/-RA.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS EXPECTED FOR AT LEAST THE NEXT FIVE DAYS. RIVER
LEVELS ARE SLOWLY FALLING ACROSS EASTERN NEW YORK AND WESTERN NEW
ENGLAND. CURRENT RIVER AND RESERVOIR LEVELS ARE NEAR TO SLIGHTLY
ABOVE NORMAL FOR HIS TIME OF YEAR. WATER TEMPERATURES ON SMALLER
STREAMS HAVE FALLEN INTO THE 30S. THEREFORE...WITH COLD TEMPERATURES
FORECAST...SOME RIVER ICE SHOULD BEGIN TO FORM LATE THIS WEEK INTO
THE WEEKEND...ESPECIALLY OVER RIVERS IN THE ADIRONDACKS AND COLDER
VALLEYS OF THE CATSKILLS AND SOUTHERN VERMONT. WATER TEMPERATURES ON
THE LARGER RIVERS SUCH AS THE TIDAL HUDSON ARE STILL IN THE 40S. IT
WILL PROBABLY BE ANOTHER WEEK BEFORE WATER TEMPERATURES ON THE
LARGER RIVERS FALL ENOUGH SO RIVER ICE BEGINS TO FORM.
RIVER FLOWS WILL CONTINUE TO DIMINISH THE NEXT SEVERAL DAYS...
EXCEPT WHERE AFFECTED BY RESERVOIR RELEASES OR DIVERSIONS. ONLY
LIGHT PRECIPITATION IS FORECAST AND IT WILL MOSTLY COME AS SNOW.
THE SOUTHWESTERN ADIRONDACK BASINS HAVE SNOW COVER ESTIMATED TO
CONTAIN AROUND AN INCH OF WATER OVER THE HEADWATERS OF THE BLACK
RIVER AND WEST CANADA CREEK. THERE IS AROUND THREE QUARTERS OF AN
INCH OF WATER IN THE SACANDAGA RIVER BASIN ABOVE HOPE AND A QUARTER
TO HALF INCH OF WATER IN THE INDIAN RIVER BASIN ABOVE INDIAN LAKE.
ELSEWHERE...SNOW WATER EQUIVALENT IS NEGLIGIBLE. DUE TO COLD
TEMPERATURES...LITTLE OR NO MELTING MAY BE EXPECTED FOR SEVERAL DAYS.
FOR DETAILS ON THE RIVERS...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...GJM
NEAR TERM...GJM
SHORT TERM...GJM
LONG TERM...JPV
AVIATION...JPV
HYDROLOGY...JPV
