FXUS61 KALY 291734
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1233 PM EST SUN NOV 29 2009
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BRIEFLY NOSE INTO OUR REGION
TODAY GIVING US DRY AND RELATIVELY MILD WEATHER. THEN ANOTHER LOW
PRESSURE SYSTEM WILL APPROACH FROM THE GREAT LAKES REGION THIS
EVENING BRINGING MORE UNSETTLED WEATHER TO THE AREA TONIGHT AND
MONDAY. THIS WILL BE FOLLOWED BY COLDER...MORE SEASONABLE WEATHER ON
MONDAY NIGHT AND TUESDAY WITH SOME LAKE EFFECT SNOW EXPECTED ACROSS
THE WESTERN ADIRONDACKS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM EST...SFC HIGH PRESSURE CONTINUES TO BUILD NORTHEAST
FROM THE VIRGINIAS WITH FAIR AND DRY WEATHER TODAY. MAX TEMPS WILL
RUN AROUND 10 DEGREES ABOVE NORMAL WITH THE SATELLITE PICTURE
SHOWING MOSTLY SUNNY SKIES...EXCEPT FOR SOME LOW CLOUDS ERODING OVER
THE WRN ADIRONDACK...AND W-CNTRL MOHAWK VALLEY. THEY SHOULD CONTINUE
TO DIMINISH. SOME CIRRUS WILL INCREASE LATER IN DAY. HOWEVER...WE
PHRASED AS MOSTLY SUNNY FROM THE CAPITAL REGION SOUTH AND
EAST...PARTLY TO MOSTLY SUNNY NORTH AND WEST. A VERY NICE DAY TO
CLOSE OUT THE HOLIDAY WEEKEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
CLIPPER TYPE SYSTEM WILL QUICKLY MOVE EAST NORTHEAST INTO THE
EASTERN GREAT LAKES THIS EVENING...UP THE SAINT LAWRENCE RIVER
VALLEY TONIGHT AND INTO THE CANADIAN MARITIMES LATE MONDAY. THIS
SYSTEM WILL DRAG A COLD FRONT THROUGH THE REGION MONDAY MORNING
WITH COLDER MORE SEASONABLE AIR BEHIND IT WHICH WILL LIKELY SET
THE STAGE FOR THE A LAKE EFFECT SNOW EVENT ACROSS THE WESTERN
ADIRONDACKS LATE MONDAY NIGHT INTO TUESDAY EVENING.
FOR TONIGHT HAVE TEMPS BOTTOMING OUT IN THE 30S...BUT REMAINING
ABOVE FREEZING EVERYWHERE. MODEL SOUNDINGS AS WELL AS PARTIAL
THICKNESS VALUES FAVOR RAIN AS THE PCPN TYPE WITH THE PCPN NOT
ARRIVING IN BULK OF FA UNTIL WELL AFTER MIDNIGHT AND NOT ACROSS
SOUTHEAST PORTION OF FA UNTIL AROUND DAYBREAK. DIFFICULT CALL ON
WHETHER OR NOT TEMPS WILL DROP QUICKLY THIS EVENING AND THEN LEVEL
OFF OR GRADUALLY DROP THROUGH THE NIGHT. FOR NOW HAVE CONTINUED
DIURNAL TEMP TREND AS EXPECT ANOTHER SLIGHT DROP IN TEMPS LATE
TONIGHT WITH ARRIVAL OF PCPN.
ON MONDAY COLD FRONT LOOKS TO MOVE THROUGH FAIRLY EARLY IN THE DAY
AND WITH STRONG COLD AIR ADVECTION THROUGH THE AFTERNOON HAVE
PLACED HIGH TEMPS ACROSS THE FA BTWN 14Z AND 16Z AND HAVE TEMPS
DROPPING BY 5 TO 10 DEGREES DURING THE AFTERNOON. H8 TEMPS DROP
FROM 0 TO +5 C AT 12Z MONDAY TO -10 TO -4 C BY 00Z TUESDAY ACROSS
FA. ALSO LINGERING PCPN ACROSS NORTHERN AREAS AND HIGHER TERRAIN
EXPECTED TO CHANGE TO SNOW SHOWERS DURING MONDAY AFTERNOON...BUT
WITH LACK OF FROZEN GROUND AND TEMPS NOT DROPPING INTO LOWER 30S
UNTIL LATE IN THE DAY AS PCPN IS TAPERING OFF DO NOT EXPECT ANY
ACCUMULATIONS HIGHER THAN A DUSTING TO AROUND A QUARTER OF AN
INCH...MAINLY ACROSS THE SOUTHERN ADIRONDACKS. HAVE HIGHS ON MONDAY
MORNING IN THE UPPER 30S TO AROUND 50 FOLLOWED BY FALLING TEMPS
DURING THE AFTERNOON. ALSO THERE DOES NOT APPEAR TO BE ALLOT OF
QPF WITH THIS SYSTEM WHICH IS TYPICAL OF CLIPPER TYPE SYSTEMS.
BULK OF FA A TENTH TO A QUARTER OF AN INCH FOR TONIGHT AND MONDAY
WITH A THIRD OF AN INCH OR A LITTLE HIGHER ACROSS THE WESTERN
ADIRONDACKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...WHILE BULK OF FA IS EXPECTED
TO HAVE LITTLE IF ANY PRECIPITATION DURING THIS PERIOD...THE
WESTERN ADIRONDACKS AND NORTHERN PORTIONS OF THE MOHAWK VALLEY
ARE EXPECTED TO RECEIVE SOME ACCUMULATING SNOW. LAKE ONTARIO
SURFACE TEMPS STILL MAINLY IN THE LOW TO MID 40S AND WITH H8 TEMPS
AROUND -8 C DIFFERENTIAL IS ENOUGH TO RESULT IN CONDITIONAL
INSTABILITY WHICH MAY ALSO BE ENHANCED BY LOW LEVEL ELEVATED CAPES
OF 25-50 J/KG ON MODEL SOUNDINGS IN THIS AREA. HAVE PUT LIKELY
POPS IN PARTS OF WESTERN ADIRONDACKS FOR TUESDAY INTO TUESDAY
EVENING WITH MAIN AXIS BETWEEN ROUTE 8 AND ROUTE 28 WITH THE BAND
EXPECTED TO GRADUALLY DRIFT SOUTH WITH TIME BEFORE DISSIPATING
LATER TUESDAY NIGHT AS LOW LEVEL FLOW BECOMES ANTICYCLONIC. THE
BAND MAY EVEN DRIFT FAR ENOUGH EAST THAT SOME UPSLOPE OCCURS
ACROSS THE WEST FACING SLOPES OF THE SOUTHERN GREEN MOUNTAINS LATE
TUESDAY AFTERNOON INTO TUESDAY EVENING. FOR SNOW AMOUNTS ACROSS
THE WESTERN ADIRONDACKS HAVE 2 TO 5 INCHES ACROSS NORTHERN
HERKIMER COUNTY AND 1 TO 5 INCHES ACROSS HAMILTON COUNTY FOR THE
PERIOD FROM LATE MONDAY NIGHT INTO TUESDAY EVENING. AS THIS LOOKS
TO BE BELOW ADVISORY CRITERIA BEING LONGER THAN 12 HOURS IN
DURATION AND PRIMARILY A 5TH TO 6TH PERIOD EVENT HAVE NOT
HIGHLIGHTED IN HWO AT THIS TIME. AREAS OUTSIDE THE LAKE BAND WILL
MAINLY HAVE VARIABLE CLOUDS AND SEASONABLE TEMPS FOR THE PERIOD
FROM MONDAY NIGHT THROUGH TUESDAY NIGHT. LOWS MONDAY NIGHT AND
TUESDAY NIGHT ARE EXPECTED TO BE IN THE UPPER TEENS TO UPPER 20S
WITH HIGHS ON TUESDAY IN THE MID 30S TO MID 40S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WARM ADVECTION BEGINS TO INCREASE AHEAD OF THE NEXT SYSTEM.
SO...WITH WARMING BOUNDARY LAYER TEMPERATURES...AND
INCREASING/THICKENING CLOUDS...TEMPERATURES SHOULD REACH WELL INTO
THE 40S IN MOST AREAS...WITH AROUND 40 MOUNTAINS.
SYSTEM CURRENTLY IN THE SOUTHWESTERN U.S. WILL TRACK ACROSS THE
NORTHERN GULF COAST STATES AS A NORTHERN STREAM UPPER IMPULSE DIVES
OUT OF CANADA. THE NORTHERN GULF COAST SYSTEM WILL BE DRAWN
NORTHEAST AND UP THE EAST COAST WEDNESDAY NIGHT AND THURSDAY. THERE
IS NO COLD ARCTIC HIGH ANCHORED TO OUR NORTH...BUT SOME RELATIVELY
COLD AIR WILL BE OVER THE REGION. LOWS WEDNESDAY NIGHT WILL LIKELY
OCCUR IN THE EARLY EVENING WEDNESDAY...THEN RISE SLOWLY THROUGH THE
NIGHT WITH THE CLOUDS AND PRECIPITATION MOVING INTO THE REGION...AS
WELL AS THE STRENGTHENING BOUNDARY LAYER WARM ADVECTION AND
FRONTOGENESIS.
THE TRACK OF THE STORM IS STILL IN QUESTION...AS A SMALL SHIFT EAST
OF WEST WILL DETERMINE NOT ONLY WHERE THE NORTHWESTERN PERIPHERY OF
THE PRECIPITATION SHIELD SETS UP...BUT PRECIPITATION TYPE AS WELL.
THE PRECIPITATION LOOKS LIKE IT WILL BEGIN LATE WEDNESDAY
NIGHT...WITH ANY LIGHT SNOW LIKELY CONFINED TO HIGHER
ELEVATIONS...BUT THERE COULD BE MIXING EVEN IN THE VALLEYS. THROUGH
THE DAY THURSDAY...TEMPERATURES WILL WARM ENOUGH JUST FOR A COLD
RAIN IN MOST AREAS...BUT SOME SNOW COULD CONTINUE IN HIGHER
ELEVATIONS. MOST OF THE PRECIPITATION WILL BE THE RESULT OF WARM
ADVECTION...FRONTOGENESIS AND ISENTROPIC LIFT...AND THERE COULD BE A
RELATIVELY SHARP NORTHWESTERN EDGE TO THE HEAVIER PRECIPITATION...
WITH AN EXPANSIVE AREA FURTHER NORTH AND WEST OF LIGHT SPRINKLY TYPE
PRECIPITATION. DETERMINISTIC GUIDANCE A LITTLE BIT COOLER THAN
ENSEMBLE MEANS...SO GOING JUST A SLIGHT BIT WARMER THAN LONG RANGE
MOS GUIDANCE. HIGHS THURSDAY IN THE LOWER 40S...MID TO UPPER 30S
MOUNTAINS...SOME MID 40S SOUTHERN AREAS. SOME ACCUMULATING SNOW IS
POSSIBLE IN HIGHER ELEVATIONS OF THE CATSKILLS...SOUTHERN GREENS AND
BERKSHIRES...DEPENDING ON HOW FAR NORTHWEST THE BAND OF HEAVIER
PRECIPITATION SETS UP...AND THE THERMAL PROFILES.
PRECIPITATION ENDS AS THE SYSTEM DEPARTS THURSDAY NIGHT...AND RAPID
COOLING OCCURS AT THE BOUNDARY LAYER. SOME LAKE EFFECT MOISTURE
WILL SPREAD ACROSS THE REGION ON WEST AND NORTHWEST WINDS. HIGH
PRESSURE ONCE AGAIN BUILDS IN FROM THE MIDWEST AND TN VALLEY. THERE
COULD BE A PROLONGED LAKE EFFECT SNOW SHOWER PERIOD FOR THE
ADIRONDACKS THURSDAY NIGHT THROUGH SATURDAY. SOME
ISOLATED/SCATTERED SNOW SHOWER ACTIVITY COULD SPREAD TO THE HUDSON
VALLEY...SOUTHERN GREENS AND BERKSHIRES FROM TIME TO TIME.
SO...INTERVALS OF CLOUDY AND PARTLY CLOUDY THROUGH THE PERIOD...WITH
ISOLATED/SCATTERED SNOW SHOWERS...RAIN/SNOW SHOWERS DURING THE DAY
IN WARMER SPOTS. LOWS IN THE 20S THURSDAY NIGHT AND FRIDAY
NIGHT...WITH SOME TEENS IN THE MOUNTAINS FRIDAY NIGHT. HIGHS FRIDAY
AND SATURDAY AROUND 40 TO THE LOWER/MID 40S...LOWER TO MID 30S IN
MOUNTAINS.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
A WEAK WARM FRONT IS LIFTING NORTH ACROSS THE ADIRONDACKS...AND A
BAND OF 3 KFT STRATOCU CLOUDINESS IS ASSOCIATED WITH THIS SFC
BOUNDARY. THIS MAY ALLOW FOR A BRIEF PERIOD OF HIGH END MVFR CIGS AT
KGFL FOR AN HOUR OR SO THIS AFTN. OTHERWISE...VFR CONDITIONS WITH
JUST SOME PASSING HIGH CLOUDS WILL BE ACROSS THE HUDSON VALLEY TAF
SITES THIS AFTN ALONG WITH LIGHT S-SW SFC WINDS OF 5 KTS OR LESS.
MID AND HIGH LEVEL CLOUDS WILL BEGIN TO INCREASE ACROSS THE REGION
THIS EVENING AS A COLD FRONT APPROACHES THE AREA FOR MONDAY. VFR
CONDITIONS SHOULD CONTINUE THROUGH MOST OF THE NIGHT. AROUND
DAYBREAK...A FEW SHOWERS WILL BEGIN ENCROACHING ON KGFL...WHICH MAY
REDUCE CIGS/VSBYS TO AT LEAST MVFR LEVELS. SOME SHOWERS WILL IMPACT
KALB/KPOU LATER IN THE MORNING AS THE FRONT MOVES
EAST-SOUTHEASTWARD. THESE SHOWERS WILL HAVE THE ABILITY TO REDUCE
CONDITIONS TO IFR...ALTHOUGH WILL NOT PLACE IN THE TAF JUST YET DUE
TO UNCERTAINTY REGARDING THE TIMING...DURATION...AND EXTENT OF ANY
IFR CONDITIONS.
OUTLOOK...
MON...VFR/MVFR/IFR. -SHRA ENDING.
TUE-WED...VFR. NO SIG WX.
THU...MVFR-IFR. RA LIKELY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH MID WEEK. HIGH PRESSURE
WILL RESULT IN DRY WEATHER TODAY WHICH WILL BE FOLLOWED BY A
A COLD FRONT AND A WEAK WAVE OF LOW PRESSURE THAT WILL BRING A
CHANCE OF RAIN AND SHOW SHOWERS SUNDAY NIGHT THRU MONDAY. TOTAL
QPF WILL RANGE FROM A TENTH TO A QUARTER OF AN INCH...WITH A THIRD
OF AN INCH OR A LITTLE HIGHER ACROSS THE ADIRONDACK REGION.
HIGH PRESSURE WILL YIELD MAINLY DRY WEATHER TUESDAY THROUGH
WEDNESDAY...EXCEPT FOR SOME LAKE EFFECT SNOW WHICH WILL BE MAINLY
CONFINED TO THE WESTERN ADIRONDACKS LATE MONDAY NIGHT INTO TUESDAY
EVENING.
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...11
NEAR TERM...WASULA
SHORT TERM...11
LONG TERM...NAS
AVIATION...FRUGIS
HYDROLOGY...11
