FXUS61 KALY 150623
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
123 AM EST TUE DEC 15 2009
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL ADVANCE EASTWARD ACROSS THE GREAT
LAKES TONIGHT INTO TUESDAY...WITH A TRAILING COLD FRONT PASSING
THROUGH EASTERN NEW YORK AND WESTERN NEW ENGLAND BY TUESDAY EVENING.
A MUCH COLDER AIR MASS WILL POUR INTO THE REGION FOR
WEDNESDAY...WITH COLD ARCTIC AIR REMAINING OVER THE REGION THROUGH
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 900 PM...MADE A FEW CHANGES TO THE OVERNIGHT PERIOD...MAINLY
FOR PTYPE ISSUES AND POPS. SOLID BATCH OF ECHOES ON RADAR ACROSS
PORTIONS OF THE ADIRONDACKS...WITH UPSTREAM RADARS INDICATING
ADDITIONAL BATCHES OF PRECIP. SO WILL INCREASE POPS TO LIKELY
ACROSS THIS AREA. STILL SOMEWHAT OF A DRY LAYER ALOFT TO
OVERCOME...SO SOME OF THIS MAY NOT BE REACHING THE GROUND
INITIALLY. OTHERWISE...SOME HIGHER REFLECTIVITIES SIGNIFYING SOME
BRIGHT BANDING WITH MELTING LAYER NOT TOO FAR ABOVE THE GROUND. IN
FACT 00Z ALB SOUNDING REVEALS ABOVE FREEZING LAYER FROM 850-775 MB
WITH THE MAX TEMP OF +4C IN THE LAYER. THIS WOULD SIGNIFY THAT
POTENTIAL FOR SOME SPOTTY FREEZING RAIN IN SOME LOCATIONS WHERE
SURFACE TEMPS WILL BE HOVERING NEAR THE FREEZING MARK. IT IS A BIT
MORE UNCLEAR ACROSS THE ADIRONDACKS...WHERE FORECAST SOUNDINGS
INDICATE MORE OF A SNOW PROFILE...BUT POSSIBLE LACK OF ICE IN
CLOUDS MAY LEAD TO SPOTTY FREEZING RAIN OR DRIZZLE. NOT CONFIDENT
ENOUGH TO MENTION MORE THAN A CHANCE OF ANY FROZEN PRECIP...SO
WILL NOT ISSUE AN ADVISORY AT THIS TIME BUT MENTION POTENTIAL IN
HWO. FORTUNATELY ANY PRECIP THAT FALLS WILL BE VERY LIGHT.
PREVIOUS NEAR TERM DISCUSSION AS OF 455 PM...
WEAK SURFACE LOW TRACKING FROM THE LOWER GREAT LAKES INTO EXTREME
NORTHERN NEW YORK BY 12Z TUESDAY WILL HAVE VERY LIMITED AMOUNTS OF
MOISTURE TO WORK WITH. MOST IF NOT ALL OF THE MEASURE ABLE PCPN WILL
REMAIN ALONG OR NORTH OF THE LOW TRACK (WARM FRONT)...SO HAVE
FORECAST NO HIGHER THAN CHANCE POPS ACROSS THE NORTHWEST THIRD OF
OF THE FORECAST AREA....NO POPS ACROSS THE SOUTHEAST THIRD...AND
MAINLY SLIGHT CHANCE POPS OVER THE CENTRAL THIRD. TEMPS WILL NOT
FALL VERY MUCH DUE TO THE MILD AIR MASS OVER THE REGION AND LOTS OF
CLOUD COVER TONIGHT. LOWS WILL ONLY BE IN THE UPPER 20S TO MID 30S.
PCPN TYPE IS FORECAST AS RAIN/SNOW SHOWERS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
FOR TUESDAY...THE LOW WILL CONTINUE TO TRACK EAST NORTHEAST ACROSS
NORTHERN NEW ENGLAND. THE COLD FRONT WILL MOVE THROUGH THE REGION
DURING THE DAY. ONCE AGAIN...NOT MUCH MOISTURE TO WORK WITH SO POPS
ARE NO HIGHER THAN CHANCE ANYWHERE IN THE FORECAST AREA...BUT SLIGHT
CHANCE OR CHANCE POPS ARE FORECAST THROUGHOUT THE FORECAST AREA FOR
TUESDAY. ONCE AGAIN RAIN/SNOW SHOWERS WILL BE THE PCPN TYPE. TEMPS
SHOULD FALL DURING THE AFTERNOON AFTER LATE MORNING OR NOONTIME
HIGHS GENERALLY IN THE MID 30S TO THE MID 40S.
FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...THE SURFACE LOW WILL
DEEPEN RAPIDLY OVER THE CANADIAN MARITIMES AS THE UPPER LEVEL TROF
ALSO SHARPENS UP AND INTENSIFIES. THIS WILL RESULT IN A COLD ARCTIC
AIRMASS POURING INTO THE REGION DURING THIS PERIOD ON A NORTHWEST
FLOW. LOWS TUESDAY NIGHT WILL BE IN THE UPPER SINGLE NUMBERS OVER
THE ADIRONDACKS...TO THE MID 20S OVER THE EXTREME SOUTHEAST WHERE
THE COLDEST AIR WILL HAVE NOT YET REACHED. ON WEDNESDAY...TEMPS WILL
NOT CLIMB THAT MUCH AS HIGHS ONLY REACH THE MID TEENS TO LOWER 30S.
LOWS WEDNESDAY NIGHT WILL BE WITHIN A FEW DEGREES OF ZERO UP
NORTH...TO THE MID TEENS SOUTH. DURING THE ENTIRE PERIOD NORTHWEST
SURFACE WINDS WILL BLOW AT 15 TO 25 MPH WITH HIGHER GUSTS...SO IT
WILL FEEL MUCH COLDER...AND THERE COULD BE SOME WIND CHILL ISSUES TO
DEAL WITH BY WEDNESDAY NIGHT.
WITH A NORTHWEST FLOW...GENERALLY BETWEEN 310 TO 330 DEGREES
EXPECTED DURING THIS PERIOD...LAKE EFFECT SNOW WILL BE CONFINED TO
THE SOUTHWEST PART OF THE FORECAST AREA WHICH INCLUDES EXTREME
SOUTHERN HERKIMER COUNTY...SOUTHWEST SCHOHARIE COUNTY...AND THE
CATSKILLS FROM GREENE COUNTY TO ULSTER COUNTY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AN ARCTIC HIGH PRESSURE RIDGE IS BEGINNING TO BUILD OVER OUR REGION
AT THE START OF THIS PERIOD. THUS...THE REMAINDER OF THE WORK WEEK
WILL BE DRY...BUT COLD. THE FIRST CHANCE POPS FOR SNOW SHOWERS
COMES ALONG SATURDAY NIGHT THROUGH SUNDAY NIGHT AS AN ELONGATED
SURFACE LOW RETROGRADES DOWN OVER THE LOWER GREAT LAKES. A COASTAL
LOW IS EXPECTED TO REMAIN WELL OUT AT SEA DURING THIS TIME TO AVOID
PHASING WITH THE GREAT LAKES SYSTEM. THE COASTAL LOW DEEPENS ON ITS
WAY UP TO NOVA SCOTIA. WE HAVE A CHANCE OF SNOW WITH THIS SYSTEM
ONLY FOR EXTREME SOUTHERN LITCHFIELD COUNTY AT THIS TIME. SUNDAY
NIGHT APPEARS TO BE THE BEST TIMING FOR THIS. AS WITH MOST COASTAL
SYSTEMS THIS FAR OUT TIME-WISE...WE'LL NEED TO KEEP A CLOSE EYE ON
THIS. THE WIND FLOW PATTERN BECOMES NORTHWESTERLY AND THE GRADIENT
TIGHTENS ON MONDAY...JUSTIFYING SLGT CHC POPS FOR LAKE EFFECT FOR
MANY AREAS...MAINLY THE HIGH TERRAIN FROM THE ADIRONDACKS TO THE
CATSKILLS.
THURSDAY WILL BE THE COLDEST DAY OF THE PERIOD...WITH HIGH
TEMPERATURES MAINLY IN ONLY THE TEENS AND 20S. FOR THE BALANCE OF
THE PERIOD...PRETTY CONSISTENT HIGHS IN THE 20S AND LOWER 30S ARE
EXPECTED. OVERNIGHT LOWS THURSDAY AND FRIDAY NIGHTS WILL RANGE FROM
AROUND ZERO IN THE ADIRONDACKS AND GREENS...TO THE MID TEENS IN THE
MID HUDSON VALLEY. THIS IS ABOUT 5 TO 10 DEGREES BELOW NORMAL.
THEREAFTER...LOWS WILL BE IN MAINLY THE SINGLE DIGITS AND TEENS.
THIS WILL MOST LIKELY AFFECT PORTIONS OF THE ADIRONDACKS AND CENTRAL
MOHAWK VALLEY. ELSEWHERE...WE HAVE JUST SLGT CHC.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/... FLIGHT CONDITIONS
WERE QUITE VARIABLE ACROSS THE REGION MONDAY NIGHT WITH MVFR CIGS
AND/OR VISIBILITY BEING THE MOST COMMON FEATURE. KALB WAS STILL
VFR AT 06Z...IF ONLY BARELY SO...AND IT IS EXPECTED TO REMAIN VFR
THRU 10Z WITH MVFR IN LOW STRATUS AND MIST FROM THEN TIL AROUND
18Z. KGFL WAS MVFR WITH 5 MILES IN RAIN AND MIST WITH SCT-BKN023.
IT IS FORECAST TO DETERIORATE TO MVFR WITH PERIODS OF IFR DUE TO
LOW STRATUS...FOG...AND DRIZZLE BETWEEN 08Z AND 12Z. KPOU WAS MVFR
DUE TO LOW STRATUS... AND WILL REMAIN SO THRU AROUND 15Z. A WEAK
AREA OF LOW PRESSURE WAS MOVING EASTWARD ACROSS THE GREAT LAKES
TONIGHT. CONDITIONS SHOULD IMPROVE THIS AFTERNOON AS A COLD FRONT
PASSES THROUGH THE AREA AND WINDS SHIFT AROUND TO THE NORTHWEST.
WINDS WILL BE LIGHT FROM THE SOUTH THRU AROUND 18Z...THEN VEER
AROUND TO WNW AND INCREASE TO AROUND 10 KNOTS...RAISING CIGS TO
OVC050 AND LATER ON TO BKN100...WITH SOME CLRG TAKING
PLACE...ESPECIALLY SOUTH OF ALBANY...LATER TONIGHT. TOWARD
DAYBREAK MVFR/IFR CONDITIONS IN LAKE EFFECT SNOW SHOWERS WILL
BEGIN TO DEVELOP AND MOVE DOWN THE MOHAWK VALLEY TOWARD KALB.
OUTLOOK...
TONIGHT...MAINLY VFR...CHC -SHSN NORTH/WEST OF KALB.
WED-THU...VFR. SOME SHSN DOWNWIND FROM LAKE ONTARIO. WINDY.
FRI...VFR. NO SIG WX.
SAT...MAINLY VFR...SLGT CHC -SHSN.
&&
.HYDROLOGY...
LIQUID EQUIVALENT AMOUNTS OF 0.25 TO 0.75 WERE COMMON ACROSS THE HSA
SUNDAY...WITH LOCALLY HIGHER AMOUNTS...UP TO...OR EVEN IN EXCESS OF
ONE INCH ACROSS PORTIONS OF THE EASTERN CATSKILLS AND WITHIN THE
HOUSATONIC BASIN. IN SOUTHERN AREAS...WHERE PRECIP FELL MAINLY AS
RAIN...RISES OF 1-2 FEET WERE OBSERVED ON SOME RIVERS.
ELSEWHERE...PRECIP WAS LARGELY FROZEN/FREEZING...WITH RISES GENERALLY
1 FOOT OR LESS.
ONLY LIGHT PRECIP IS EXPECTED OVER THE NEXT 24 HOURS...MAINLY ACROSS
NORTHERN BASINS...WHERE LIQUID EQUIVALENT AMOUNTS SHOULD GENERALLY
REMAIN UNDER ONE QUARTER OF AN INCH. IN ADDITION...MUCH OF THIS
PRECIP SHOULD BE FROZEN...PRODUCING MINIMAL IMPACT ON
RIVERS/STREAMS. ELSEWHERE...ONLY LIGHT QPF IS EXPECTED THROUGH AT
LEAST FRIDAY...IN THE FORM OF SNOW.
AS DAILY MEAN TEMPERATURES FALL WELL BELOW FREEZING WED-FRI...ICE
FORMATION IS EXPECTED ON ALL AREA RIVERS/STREAMS WITH PERHAPS THE
EXCEPTION OF THE LARGER STEM HUDSON.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...GJM
NEAR TERM...GJM/JPV
SHORT TERM...GJM
LONG TERM...ELH
AVIATION...RCK
HYDROLOGY...KL
