FXUS61 KALY 260625
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
125 AM EST SAT DEC 26 2009

.SYNOPSIS...
AN OCCLUDED FRONT WILL LIFT NORTHEAST THROUGH THE MID ATLANTIC
STATES AND NEW YORK TODAY AND TONIGHT. WEAK LOW PRESSURE WILL MOVE
FROM THE VIRGINIA CAPES TO LONG ISLAND. THIS SYSTEM WILL BRING A
WINTRY MIX TO THE REGION...BEFORE CHANGING TO RAIN DURING TODAY. 
SUNDAY THE REGION WILL BE BETWEEN SYSTEMS AS SOME DRIER AIR WORKS
IN FROM THE SOUTHWEST. SUNDAY NIGHT AND MONDAY A MID LEVEL
DISTURBANCE AND A COLD FRONT WILL MOVE ACROSS THE REGION BRINGING
SNOW SHOWERS AND IN ITS WAKE USHER IN MUCH COLDER AIR. HIGH
PRESSURE WILL BUILD FROM THE MIDWEST TO THE NORTHEAST
MIDWEEK...BEFORE THE NEXT STORM SYSTEM ORGANIZES ALONG THE
CAROLINA COAST TO BRING A THREAT OF MORE WINTER WEATHER TO END THE
YEAR.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LATEST RUC/RADAR/SFC MSAS/LAPSS ANALYSES SHOWS THERMAL
ADVECTION PCPN MOVING IN AHEAD OF AN OCCLUDED FRONT TIED TO THE
POTENT STORM SYSTEM OVER THE UPPER MIDWEST...AND IN ADVANCE OF A
SECONDARY SFC WAVE DEVELOPING OVER THE MID ATLANTIC REGION. THE
OVER RUNNING SCENARIO HAS SET UP DUE TO THE COLD AIR DAMMING
INVOKED BY THE SFC ANTICYCLONE SLIDING EASTWARD OVER S-CNTRL
QUEBEC.

THE PCPN WAS SLOWING MOVING INTO LOCATIONS SOUTH AND WEST OF THE
CAPITAL REGION AS OF 845 PM EST. WE HAVE SEEN SOME -FZRA/-SN
REPORTED FROM KMGJ/KSWF. KPOU HAS RISEN TO 36F...BUT WE BELIEVE
THEY WILL WET BULB DOWN TO OR BELOW FREEZING. A BRIEF PERIOD OF MIXED
PCPN IS LIKELY THERE INTO THE EARLY MORNING HOURS. HOWEVER...AS
ONE GOES NORTHWARD MORE COLD AIR IS IN PLACE FOR A PERIOD OF SNOW
AND SLEET. THE 00Z KALB SOUNDING SHOWS A 2-3C WARM NOSE AT H825.
IT IS DRY IN THE LAYER...AND WITH SATURATION SHOULD COOL DOWN. WE
WILL CONTINUE MENTION OF AN INCH OR SO OF SNOW AND SLEET IN THE
CAPITAL REGION. WE MENTIONED -IP/-FZRA TO START AT KPOU BEFORE GOING
TO -FZRA/-RA BTWN 09Z-12Z. FURTHER NORTH...WE INCREASED THE SNOW
AMOUNTS TO A COUPLE OF INCHES FOR THE SOUTHERN ADIRONDACK REGION
AFTER MIDNIGHT WITH THE RELATIVELY DEEP COLD AIR THAT WILL SLOWLY
ERODE ALOFT. ALL AND ALL...PREVIOUS FORECAST PRETTY MUCH ON TRACK.

AS WE APPROACH DAYBREAK...A TRANSITION TO SLEET/FREEZING RAIN IS 
EXPECTED TO OCCUR ACROSS THE MID HUDSON VALLEY...NW CT...AND THE 
SCHOHARIE VALLEY...EXTENDING NNW INTO THE WESTERN MOHAWK VALLEY AND 
SW DACKS...WHILE SLEET MIXES WITH SNOW FURTHER N AND E INTO THE 
CAPITAL REGION.

FOR MIN TEMPS...HAVE GENERALLY FOLLOWED CLOSE TO...OR EVEN A TAD 
ABOVE THE WARMER MET MOS...GIVEN THE LOW CLOUDS IN PLACE ACROSS 
VALLEY REGIONS...AND HIGHER LEVEL CLOUDS RAPIDLY INCREASING 
ELSEWHERE. DID INDICATE COLDER MINS ACROSS PORTIONS OF SOUTHERN VT 
AND THE NORTHERN BERKS...WHERE ENOUGH TRANSPARENCY IN THE HIGH 
CLOUDS MAY ALLOW TEMPS TO DROP SEVERAL DEGREES THIS EVENING...BEFORE 
BECOME STEADY OR EVEN RISE AFTER MIDNIGHT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
SATURDAY/SAT NT...A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN SHOULD BE 
ONGOING AT OR JUST AFTER DAYBREAK FROM THE CAPITAL REGION S AND 
W...WITH MAINLY FREEZING RAIN/SLEET ACROSS THE MID HUDSON VALLEY AND 
NW CT/SOUTHERN BERKS...AND MAINLY SNOW ACROSS SOUTHERN VT INTO THE 
LAKE GEORGE/SARATOGA REGION AND AREAS JUST N OF THE MOHAWK RIVER. 
THE PRECIP SHOULD TRANSITION TO MAINLY FREEZING RAIN/FREEZING 
DRIZZLE BY MID MORNING...WITH PLAIN RAIN/DRIZZLE ACROSS THE MID 
HUDSON VALLEY. GIVEN A STRONG LOW LEVEL N/NNE AGEOSTROPHIC WIND 
COMPONENT OF 40-50 KT WITHIN THE 1000-900 MB LAYER...HAVE INDICATED 
MAX TEMPS COLDER THAN MOST MOS GUIDANCE. THIS WILL KEEP POCKETS OF 
FREEZING RAIN INTO AT LEAST THE EVENING ACROSS THE HIGHER ELEVATIONS 
WITHIN THE EASTERN CATSKILLS...AND NORTHERN PORTIONS OF THE HUDSON 
RIVER VALLEY/LAKE GEORGE REGION...AS WELL AS HIGHER ELEVATIONS 
WITHIN EASTERN BENNINGTON CO/WESTERN WINDHAM CO. IN THESE 
REGIONS...ICE ACCRETION OF UP TO...OR SLIGHTLY IN EXCESS OF ONE 
THIRD OF AN INCH COULD OCCUR BY EVENING. FORTUNATELY...PRECIP 
INTENSITY SHOULD REMAIN GENERALLY LIGHT...WITH SOME BREAKS IN THE 
STEADY PRECIP POSSIBLE FROM LATE MORNING INTO MID AFTERNOON AS THE 
STRONGER UPPER LEVEL DYNAMICS/MOISTURE ADVECTION HOLD OFF UNTIL LATE 
AFTERNOON AFTER THE INITIAL BURST IN THE MORNING. E/SE WINDS WILL 
ALSO INCREASE ACROSS HIGHER ELEVATIONS OF THE TACONICS/SOUTHERN 
GREENS/BERKS...ESP TOWARD AND AFTER SUNSET...WELL INTO THE OVERNIGHT 
HOURS. GIVEN WIND SPEEDS POTENTIALLY REACHING 45-55 KT AT 925 
MB...HAVE HOISTED WIND ADVISORIES FOR THE AFOREMENTIONED 
REGIONS...WHERE WINDS OF THIS DIRECTION TEND TO 
FUNNEL/ENHANCE...WITH POSSIBLE GUSTS REACHING 45-55 MPH. 
OTHERWISE...MOST TEMPS SHOULD RISE ABOVE FREEZING ACROSS THE REGION 
ONCE MOD PRECIP DEVELOPS SAT NT...WITH PERIODS OF RAIN EXPECTED. IN 
FACT...SOME ELEVATED INSTABILITY HAS BEEN NOTED IN THE NAM12...WITH 
850 LI/S REACHING 0 TO -1 ACROSS EASTERN AREAS SAT EVE. THUS...A FEW 
RUMBLES OF THUNDER CAN NOT BE RULED OUT IN THESE AREAS...BUT DUE TO 
OVERALL LOW CHC...HAVE KEPT OUT MENTION AT THIS TIME. RAIN SHOULD 
TAPER OFF IN INTENSITY FROM SW TO NE PRIOR TO DAYBREAK SUNDAY.

SUN...ANY LINGERING PRECIP SHOULD END QUICKLY SUN MORNING...WITH A 
BREAK IN PRECIP EXPECTED DURING MUCH OF THE DAY. THERE IS AT LEAST A 
POSSIBILITY OF SOME BREAKS IN THE CLOUDS TO DEVELOP WITHIN VALLEY 
REGION...ESP SUN MORNING...BEFORE COOLING MID LEVELS ALLOW CLOUDS TO 
REDEVELOP FROM THE CAPITAL REGION N AND W DURING THE MID/LATE 
AFTERNOON. HOWEVER...SHOULD LOW LEVEL MOISTURE REMAIN MORE 
ABUNDANT...AS THE NAM12 IMPLIES...LOW CLOUDS MAY PERSIST. SO...GIVEN 
THE UNCERTAINTY...HAVE GENERALLY LEANED TOWARD MORE CLOUDS ACROSS 
EASTERN AREAS...WHERE UPSLOPE W WINDS SHOULD ALLOW CLOUDS TO BE MORE 
PREVALENT...WITH P SUNNY CONDITIONS WITHIN THE VALLEYS. MAX TEMPS 
SHOULD REACH THE LOWER 40S WITHIN THE VALLEYS...AND 30S FOR HIGHER 
ELEVATIONS...ALTHOUGH MAXES MAY OCCUR DURING THE LATE MORNING BEFORE 
SLOWLY FALLING IN THE AFTERNOON WITH INTENSIFYING COLD ADVECTION.

SUN NT...POTENTIALLY INTERESTING SCENARIO DEVELOPING FOR LATE SUN 
NT...AS REMNANT UPPER LEVEL LOW ASSOCIATED WITH CURRENT MIDWESTERN 
SYSTEM PASSES NEAR OR SOUTH OF THE REGION. DEPENDING ON ITS 
TRACK...A PORTION OF OUR REGION MAY LIE WITHIN A FAVORABLY 
DEFORMATION REGION LATE AT NIGHT OR MON MORNING...ACCOMPANIED BY A 
BURST OF SNOW. THIS COULD LEAD TO SOME QUICK...ALBEIT RELATIVELY 
MINOR ACCUMS. THIS WILL NEED TO BE WATCHED...ESP SINCE TIMING COULD 
OCCUR TOWARD OR DURING THE MON MORNING RUSH HOUR.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
WENT WITH MOS GUIDANCE...WHICH HELPS US FIT OUR GEOGRAPHICAL PUZZLE 
PIECE WELL FOR TEMPS.  A COLD FRONT WILL SLIDE TOWARD THE REGION 
FROM SOUTH CENTRAL CANADA AT THE BEGINNING OF THE PERIOD.  THIS WILL 
BRING US A GOOD CHANCE OF SNOW SHOWERS...ALONG WITH STRONG WINDS AND 
MUCH COLDER TEMPERATURES...AS ASSOCIATED LOW PRESSURE DEEPENS AROUND 
NEWFOUNDLAND.

HIGH PRESSURE JUST BEGINS TO SETTLE IN ON TUESDAY...AS NORTHWESTERLY 
WINDS WON'T SUBSIDE UNTIL TUESDAY NIGHT.  WITH VERY DRY AIR 
INFILTRATING THE REGION...HAVE ONLY A SLGT CHC FOR LAKE EFFECT IN 
THE FAR WESTERN ADIRONDACKS TUE THRU WED.

A COMPLEX...THOUGH RELATIVELY TIMID SCENARIO EVOLVES FOR MID- TO 
LATE-WEEK.  A WEAK COASTAL LOW OFF CAPE HATTERAS WILL TRACK 
NORTHEAST OUT TO THE SEA ACCORDING TO THE GFS.  MEANWHILE...A WEAK 
CLIPPER-LIKE SYSTEM WILL TRACK GENERALLY EAST ACROSS THE GREAT 
LAKES...POSSIBLY TAPPING SOME MOISTURE FROM THE COASTAL LOW LATE IN 
THE GAME.  HOWEVER...QPFS ARE VERY LIGHT.  GFS THEN LIFTS THIS LOW 
NORTH INTO QUEBEC.

A COUPLE OF PRETTY COLD DAYS ARE ON TAP BEHIND THE CANADIAN FRONT... 
WITH HIGHS ON TUESDAY IN ONLY THE TEENS AND 20S.  DECENT SUNSHINE 
WILL HELP TEMPERATURES BOUNCE BACK RATHER SWIFTLY...WITH HIGHS BY 
THU AND FRI IN THE MID 20S AND 30S.  TUE NIGHT WILL BE COLDEST... 
WITH ALMOST ALL LOCATIONS DOWN INTO THE SINGLE DIGITS...MAINLY BELOW 
ZERO IN THE ADIRONDACKS.  BY THURSDAY NIGHT...MOST LOWS WILL BE DOWN 
ONLY INTO THE TEENS.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AN AREA OF ISENTROPIC LIFT AHEAD OF AN OCCLUDED FRONT IS
PRODUCING A BAND OF PRECIPITATION WHICH IS MOVING ACROSS THE
AREA AT THIS TIME. THIS AREA IS PRODUCING A VARIETY OF
PRECIPITATION TYPES OVER THE REGION WITH SNOW MIXED WITH SLEET
THE MOST COMMON...BUT RAIN IN MID HUDSON VALLY...AND FREEZING RAIN
IN WESTERN MOHAWK VALLY AND WESTERN ADIRONDACKS. THE RESULT WILL
BE WIDESPREAD IFR TILL MORNING.

THIS FRONT IS DECELERATING...BUT THIS FIRST AREA OF PRECIPITATION
WILL LIFT NORTHEAST OF REGION 12-15UTC...AND LEAVE THE OCCLUDED
FRONT FM ERI-ORF. WITH DEVELOPING COASTAL LOW OVER THE VIRGINIA
CAPES SOUTHEAST INFLOW OF MOISTURE WILL CONTINUE MOST OF THE DAY.
FOR MOST OF THE REGION MVFR.

THE INITIAL LOWER CIGS AND VSBY WILL BE MAINLY THE RESULT OF
PRECIPITATION OVERNIGHT...BUT BY AFTN MOST OF THE ICE IN THE CLOUDS
DISAPPEARS DUE TO MID LEVEL DRYING AND WARMING...AND EVEN THOUGH
TEMPS WILL BE BLOW FREEZING IN MANY NORTHERN AREAS...PCPN WILL
BECOME AREA OF DRIZZLE...OR FREEZING DRIZZLE....BEFORE CHANGING TO
ALL RAIN/DRIZZLE LATER IN THE DAY. MOST OF THE DAY WILL HAVE MVFR
CIGS AND VSBY IN THIS SITUATION...BUT AS THE LOW MOVES UP THE
COAST AREAS OF IFR WILL BECOME MORE COMMON IN THE AFTERNOON. IN
ADDITION WHILE THE SFC LOW IS NOT PARTICULARLY STRONG ITS
EXISTENCE AND THE GRADIENT WITH A 1036 HPA HIGH OVER THE
MARITIMES WILL RESULT IN A RATHER STRONG WIND GRADIENT SETTING UP
OVER THE REGION.

WHILE SFC WINDS SHOULD REMAIN LIGHT EASTERLY AROUND 10KTS...WINDS
2-3K FEET WILL BE 15-30KTS AND INCREASE DURING THE DAY TO 25 TO
40KTS WITH LLWS DEVELOPING ACR0SS THE REGION..PARTICULARLY THE N-S
VALLEYS. LATER TAFS WILL PROBABLY INCLUDE LLWS.

OUTLOOK...
SAT NGT...MVFR-IFR WITH -RA. 
SUN...VFR...MVFR POSSIBLE WITH CHC -SHRA/-SHSN.
MON...VFR...MVFR POSSIBLE WITH CHC -SHSN. 
TUE- WED...VFR...NO SIG WX.

&&

.HYDROLOGY...
A WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN IS EXPECTED TO START 
LATE THIS EVENING AND TRANSITION TO FREEZING RAIN LATE TONIGHT INTO 
SATURDAY MORNING AND THEN EVENTUALLY RAIN SATURDAY AFTERNOON INTO 
SATURDAY EVENING. THE TRANSITION TO RAIN WILL BE QUICKER FARTHER 
SOUTH...MAINLY ACROSS THE MIDDLE AND LOWER HOUSATONIC BASIN...THE 
RONDOUT CREEK...WAPPINGERS CREEK...AND ESOPUS CREEK AND IN THESE 
AREAS QPF AMOUNTS MAY LOCALLY EXCEED 1 INCH WHICH MAY RESULT IN 
RISES OF SEVERAL FEET. AT THIS TIME IT DOES NOT APPEAR THAT THERE 
WILL BE ENOUGH RUNOFF FOR FLOODING.

ACROSS THE REMAINDER OF THE HSA...THE RUNOFF WILL BE LESS AS SOME 
SNOW COVER WILL ABSORB SOME OF THE RUNOFF...AND ANY RUNOFF THAT DOES 
OCCUR WILL BE LESS DUE TO COLDER TEMPERATURES ON SATURDAY.

AFTER THE SYSTEM WINDS DOWN ON SUNDAY...IT WILL BE MAINLY DRY INTO 
EARLY NEXT WEEK. IT WILL TURN COLDER SO THAT PRECIPITATION SHOULD 
COME AS SNOW. TEMPERATURES ARE FORECAST TO DROP BELOW FREEZING 
SUNDAY NIGHT AND REMAIN BELOW FREEZING IN MOST AREAS THROUGH AT 
LEAST THE MIDDLE OF NEXT WEEK.

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...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR 
     NYZ038>041-043-047>054-058-063-083-084.
     FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ059>061-
     064>066.
     WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST SUNDAY FOR 
     NYZ054-061-084.
     WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR NYZ032-033-
     042-082.
MA...FREEZING RAIN ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR 
     MAZ001-025.
     WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST SUNDAY FOR 
     MAZ001-025.
VT...WIND ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST SUNDAY FOR 
     VTZ013-014.
     WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR VTZ013>015.

&&

$$
SYNOPSIS...SNYDER
NEAR TERM...KL/WASULA
SHORT TERM...KL
LONG TERM...ELH
AVIATION...SNYDER 
HYDROLOGY...11