FXUS61 KALY 300138
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
840 PM EST SUN NOV 29 2009

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE REGION TONIGHT AND MONDAY 
BRINGING RAIN AND SNOW SHOWERS TO THE AREA. A MORE SEASONABLE 
AIRMASS WILL BE USHERED IN BEHIND THIS SYSTEM WITH SOME LAKE EFFECT 
SNOW EXPECTED ACROSS PORTIONS THE WESTERN ADIRONDACKS MONDAY NIGHT 
AND TUESDAY. HIGH PRESSURE WILL BUILD IN TUESDAY NIGHT AND SHOULD 
DOMINATE OUR WEATHER WEDNESDAY. WIDESPREAD PRECIPITATION...MAINLY 
RAIN...IS EXPECTED WEDNESDAY NIGHT AND THURSDAY AS STORM SYSTEM 
APPROACHES FROM THE SOUTH. 

&&

.NEAR TERM /THROUGH MONDAY/...
TWO MESONET TYPE SITES...STILLWATER RESERVOIR AND OLD FORGE...
IN THE WESTERN ADIRONDACKS EXPERIENCED TEMPERATURE RISES OF 
AROUND 5 DEGREES IN THE PAST HOUR OR TWO...WITH CLOUDS AND 
WARMER AIR STREAMING IN FROM THE WEST. MEANWHILE...TEMPERATURES
IN THE HUDSON VALLEY...KGFL...KALB...AND KPOU...WERE SEVERAL 
DEGREES COOLER THAN FORECAST AT THIS TIME. FEELING IS THAT 
TEMPERATURES IN THE HUDSON VALLEY AND EAST MAY DROP A DEGREE
OR TWO IN THE NEXT TWO HOURS...THEN RISE SOME DURING THE EARLY
MORNING HOURS WHILE FARTHER NORTHWEST THEY WILL NOT SHOW MUCH  
CHANGE. THE 00Z ALY SOUNDING WAS WELL ABOVE ZERO THROUGH 800 HPA
AND THE BUF SOUNDING WELL ABOVE ZERO THRU 850. WITH LOW LEVEL 
WINDS SW/WSW...FEEL PRECIP OVERNIGHT WILL BE ALL LIQUID SO HAVE
REMOVED MENTION OF SNOW FOR OVERNIGHT PERIODS. HAVE ALSO UPDATED
SKY COVER PER LATEST OBS AND SAT IMAGES...AND BASED ON RADAR 
HAVE MOVED THE POPS A BIT FARTHER SOUTH FOR THE EARLIER PERIODS. 
OVERNIGHT LOWS WILL RANGE FROM THE MID 30S ACROSS THE HUDSON 
VALLEY NORTH OF ALBANY AND OVER SOUTHERN VERMONT TO THE LOW
40S ACROSS THE WESTERN MOHAWK VALLEY AND THE HUDSON VALLEY 
SOUTH OF ALBANY...AND NEAR 40 ACROSS THE WESTERN ADIRONDACKS
WHERE WARM AIR ADVECTION WAS ALREADY TAKING PLACE AND LOW 
CLOUDS WILL INHIBIT ANY RADIATIONAL COOLING.

THE RIDGE OVER THE AREA WILL SHIFT EAST OFFSHORE THIS EVENING AND A 
LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL MOVE EAST ACROSS THE 
LOCAL AREA LATE TONIGHT AND MONDAY MORNING. CLOUDS WILL BE ON THE 
INCREASE THIS EVENING. MOST OF THE PRECIPITATION ASSOCIATED WITH THE 
SYSTEM WILL OCCUR ALONG AND BEHIND THE COLD FRONT WITH THE UPPER 
LEVEL SUPPORT WHICH LAGS. LONGWAVE TROUGH DIGS IN OVER REGION DURING 
THE DAY MONDAY. TEMPERATURES WILL DROP DURING THE AFTERNOON IN THE 
COLD AIR ADVECTION. THE 850 MB 0C ISOTHERM REACHES THE MID/LOWER 
HUDSON VALLEY BY EARLY AFTERNOON AND MOVES OFFSHORE...SOUTH OF LONG 
ISLAND...BY EARLY EVENING. HIGHS WILL RANGE FROM THE UPPER 30S 
ACROSS THE HIGHER TERRAIN OF SOUTHERN VT AND NEAR 40 ACROSS THE
ADIRONDACKS...WHERE THE HIGH WILL PROBABLY OCCUR BEFORE NOON...
TO THE LOWER 50S IN THE HUDSON VALLEY SOUTH OF ALBANY.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
ADDITIONAL SHORT WAVE ENERGY DIVES INTO THE TROUGH MONDAY NIGHT AS 
SURFACE HIGH TRIES TO BUILD IN. THE UPPER TROUGH AXIS MOVES TO OUR 
EAST TUESDAY MORNING WITH CYCLONIC FLOW ACROSS THE REGION. LAKE 
ONTARIO SURFACE WATER TEMPERATURE IS IN THE UPPER 40S AND WITH THE 
COLDER MORE SEASONABLE AIRMASS BEING USHERING IN SOME LAKE EFFECT 
SHOWERS ARE EXPECTED ACROSS PORTIONS OF THE WESTERN ADIRONDACKS WITH 
WESTERLY LOW LEVEL FLOW TUESDAY. LIGHT SNOW ACCUMULATIONS OF 1 TO 2 
INCHES ARE EXPECTED AT THIS TIME. THE LAKE EFFECT WILL GET CUT OFF
AS RIDGING BUILDS AT THE SURFACE AND ALOFT TUESDAY NIGHT. THE RIDGE
IS EXPECTED TO DOMINATE OUR WEATHER WEDNESDAY WITH A STORM
APPROACHING FROM THE SOUTH.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE DETERMINISTIC LONG RANGE GUIDANCE /ECMWF...GFS...CANADIAN GGEM/ 
AND THE ENSEMBLES CONTINUE TO INDICATE A STORM SYSTEM INTERACTING 
WITH THE SUBTROPICAL JET STREAM WILL APPROACH FROM THE TN AND OH 
VALLEYS WED NIGHT.  THIS SYSTEM WILL BE UTILIZING GULF OF MEXICO 
MOISTURE.  THE EXACT TRACK OF THE INTENSIFYING LOW PRESSURE SYSTEM 
IN THE SOUTHWEST FLOW ALOFT IS STILL VARIABLE FROM THE 
GUIDANCE...THOUGH THE 12 GEFS MEAN BRINGS THE LOW ACROSS E-CNTRL PA 
AND OVER THE CAPITAL REGION BTWN 12Z-18Z THU.  THERE IS QUITE A BIT 
OF SPREAD WITH A FEW MEMBERS AS FAR WEST AS ERN MI...AND AS FAR 
SOUTH AND EAST TO THE DELMARVA REGION.  THE ENSEMBLE MEAN MSLP OF 
THE SFC CYCLONE IS 988 HPA...SO A DEEPENING AND INTENSIFYING WAVE IS 
IMPLIED.  HOWEVER...THERE IS NOT A COLD CANADIAN ANTICYCLONE TO THE 
NORTH ENTRENCHING COLD AIR AHEAD OF THE WAVE.  THE THERMAL PROFILES 
ARE WARM FOR PREDOMINANTLY AN ALL RAIN EVENT FOR THE HEART OF THE 
EVENT.  A MOISTURE RICH LOW LEVEL BAROCLINIC ZONE SHOULD YIELD SOME 
PERIODS OF RAIN /POSSIBLY MODERATE TO HVY AT TIMES/ WEDNESDAY NIGHT 
INTO THURSDAY...AND WE HAVE ADDRESSED THE BETTER CHANCES OF RAIN 
WITH LIKELY POPS FCST AREA WIDE ON THU.

THU NIGHT INTO FRI...THE STRONG SFC WAVE ACCELERATES NORTHEAST AS IT 
REMAINS AN OPEN WAVE ALOFT.  STRONG COLD AIR ADVECTION OCCURS IN THE 
WAKE OF THE SYSTEM WITH SOME LAKE ENHANCED PCPN POSSIBLE FOR THE WRN 
PORTION OF THE FCST AREA. H850 TEMPS TUMBLE TO AROUND -10C FOR THE 
BULK OF THE FCST AREA.

SATURDAY...BROAD CYCLONIC FLOW PERSISTS TO OPEN THE WEEKEND WITH 
COLD AIR FUNNELING SOUTHEAST TOWARDS THE REGION FROM THE S-CNTRL 
ONTARIO.  SOME LAKE EFFECT -SHSN/S WILL PERSIST WEST OF THE HUDSON 
RIVER VALLEY.

SATURDAY NIGHT INTO SUNDAY...THE LOW LEVEL FLOW BEGINS TO SHIFT AND 
BECOME ANTICYCLONIC WITH SFC HIGH PRESSURE NOSING IN FROM THE OH 
VALLEY/MID ATLANTIC REGION.  TEMPS WILL MODERATE TO NEAR NORMAL 
VALUES FOR EARLY DEC.  MOST OF THE FCST AREA LOOKS LIKE IT WILL HAVE 
A FAIRLY DRY WEEKEND AT THIS POINT IN TIME.

OVERALL...PCPN LOOKS ABOVE NORMAL BASED ON THE STORM SYSTEM FOR 
THU...AND TEMPS WILL BE NEAR NORMAL OR SLIGHTLY BELOW NORMAL FOR THE 
STRETCH.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MID AND HIGH LEVEL CLOUDS WERE OVERSPREADING THE REGINO THIS 
EVENING AS A COLD FRONT APPROACHES THE AREA. VFR FLIGHT CONDITIONS
WILL CONTINUE UNTIL SEVERAL HOURS PAST MIDNIGHT WHEN STARTING AROUND
08Z-010Z CIGS AND VISBY WILL DETERIORATE TO MVFR FROM NORTHWEST TO 
SOUTHEAST...WITH RAIN SHOWERS MOVING IN FROM THE NORTHWEST STARTING
BETWEEN 08Z AND 10Z. AT THIS POINT IT APPEARS THAT THE HUDSON VALLEY 
TAF SITES WILL STAY MVFR THROUGH MUCH OF THE DAY MONDAY...IN RAIN 
SHOWERS AND MIST. CONDITIONS WILL IMPROVE LATE IN THE AFTERNOON 
AS THE SHOWERS END AND CLOUD BASES GO ABOVE VFR MINIMUMS. IFR 
CIGS ARE LIKELY TO BE ENCOUNTERED ACROSS THE HIGHER TERRAIN EAST 
AND WEST OF THE HUDSON VALLEY DURING MUCH OF THE DAY.  

WINDS WILL BE NEAR CALM UNTIL SHORTLY BEFORE DAYBREAK...START 
LIGHT FROM THE SOUTHWEST...THEN GRADUALLY INCREASE TO BETWEEN
6 AND 8 KNOTS AND VEER AROUND TO THE NORTHWEST BY MID AFTEROON. 
 
OUTLOOK... 
MON NIGHT-TUE...VFR WITH MVFR IN LAKE EFFECT -SHSN WRN ADIRONDACKS.
TUE NIGHT-WED...VFR...NO SIG WX.
WED NIGHT- THU...MVFR-IFR. RA LIKELY. 
FRI...VFR...CHC -SHRA/-SHSN.

&&

.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED THE NEXT FIVE DAYS. A 
COLD FRONT AND A WEAK WAVE OF LOW PRESSURE WILL BRING LIGHT PCPN TO 
THE HYDRO SERVICE AREA /HSA/ SUNDAY NIGHT THRU MONDAY IN THE FORM OF 
RAIN AND SNOW SHOWERS.  TOTAL QPF WILL RANGE FROM A TENTH TO A THIRD 
OF AN INCH.
  
HIGH PRESSURE WILL YIELD MAINLY DRY WEATHER TUESDAY THROUGH 
WEDNESDAY...EXCEPT FOR SOME LIGHT LAKE EFFECT SNOW WHICH WILL BE 
MAINLY CONFINED TO THE WESTERN ADIRONDACKS LATE MONDAY NIGHT INTO 
TUESDAY EVENING.

A STORM SYSTEM APPROACHING FROM THE OH VALLEY WEDNESDAY NIGHT MAY 
BRING A SOAKING RAINFALL TO THE HSA THU WITH RAINFALL AMOUNTS 
RANGING FROM A HALF AN INCH TO AN INCH AND A HALF. 

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...IAA
NEAR TERM...RCK/IAA
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...RCK
HYDROLOGY...WASULA