000 FXUS61 KALY 100555 AFDALY AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 1255 AM EST FRI FEB 10 2012 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE GREAT LAKES AND SOUTHEAST CANADA FRIDAY...PASSING ACROSS THE REGION LATE FRIDAY NIGHT AND SATURDAY MORNING. AS THE FRONT PASSES...EXPECT SOME SNOW SHOWERS...ALTHOUGH A PERIOD OF STEADIER LIGHT SNOW WILL BE POSSIBLE ACROSS SOUTHEAST AREAS AS A DEVELOPING LOW PRESSURE SYSTEM PASSES OFF THE EAST COAST. MUCH COLDER AIR WILL FILTER INTO THE REGION BEHIND THIS FRONT...WITH TEMPERATURES REMAINING WELL BELOW NORMAL INTO SUNDAY BEFORE GRADUALLY MODERATING EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1215 AM...FORECAST LOOKS GOOD WITH ONLY SOME MINOR ADJUSTMENTS BASED ON OBSERVATIONAL DATA. AS OF 940 PM EST...HAVE MADE SOME MINOR ADJUSTMENTS BASED ON RECENT OBS. TRICKY CALL OVERNIGHT REGARDING MIN TEMPS...AS SOME AREAS HAVE DECOUPLED...WITH TEMPS ALREADY DROPPING A FEW DEGREES ABOVE FORECAST MINS...WHILE OTHER AREAS HAVE MAINTAINED A BIT OF WIND...WITH TEMPS ONLY FALLING INTO THE LOWER 30S. BASED ON 00Z/10 KALY SOUNDING...AN ABUNDANCE OF DRY AIR IS IN PLACE WITH A PWAT OF 0.12...SO IT WOULD APPEAR THAT THE POTENTIAL CONTINUES FOR A RAPID DROP IN TEMPS IN ANY AREAS WHERE WINDS BECOME CALM. THEREFORE...HAVE NOT MADE SIGNIFICANT CHANGES TO OVERNIGHT MINS...JUST A COUPLE OF DEGREES CHANGE OR LESS FROM PREVIOUS DATABASE. REGARDING FRIDAY/S MAX TEMPS...WILL NEED TO WATCH EVOLUTION OF LOW CLOUDS ACROSS OHIO VALLEY...AS WELL AS COOLER 925 MB TEMPS NOTED TO OUR S AND W BASED ON 00Z SOUNDINGS. GIVEN A SW FLOW AT THIS LEVEL...THIS WOULD ACTUALLY INDICATE SOME COOLING WITHIN THE 925-850 MB LAYER OVERNIGHT INTO FRIDAY...POSSIBLY RESULTING IN COOLER MAX TEMPS THAN CURRENTLY FORECAST. PREVIOUS DISCUSSION FOLLOWS... AS OF 630 PM EST...ONLY SOME MINOR TWEAKS TO GRIDDED DATABASE TO ACCOUNT FOR RECENT OBS...INCLUDING THE RAPIDLY FALLING TEMPS IN SOME AREAS. PREVIOUS DISCUSSION FOLLOWS... AS OF 420 PM EST...SKIES REMAIN ESSENTIALLY CLOUDLESS ACROSS THE ENTIRE AREA...AS EVEN THE PREVIOUS LOW CLOUDS ACROSS THE WESTERN ADIRONDACKS HAVE DISSIPATED. THE COMBINATION OF ABUNDANT SUNSHINE...LITTLE OR NO SNOW COVER...AND DEEP MIXING HAS ALLOWED TEMPS TO REACH THE LOWER/MID 40S IN MANY VALLEY AREAS...AND 30S ACROSS MOST HIGHER ELEVATIONS. FOR TONIGHT...WE EXPECT GENERALLY CLEAR SKIES TO CONTINUE. SOME PATCHY CLOUDS COULD REFORM ACROSS EXTREME NORTHERN HERKIMER/HAMILTON COS AT SOME POINT...SO HAVE INCLUDED PATCHY CLOUDS IN THAT REGION. THE COMBINATION OF CLEAR SKIES...DIMINISHING WIND AND A DRY ATMOSPHERE SHOULD ALLOW TEMPS TO PLUMMET FROM AFTERNOON MAXES...WITH 20-25 EXPECTED ACROSS MOST VALLEYS...AND TEENS ACROSS THE SOUTHERN ADIRONDACKS...AND LAKE GEORGE/SARATOGA REGION. SLIGHTLY COLDER MINS COULD OCCUR THAN CURRENTLY FORECAST GIVEN SUCH POTENTIALLY IDEAL RADITIONAL COOLING CONDITIONS. THESE FORECAST MIN TEMPS WERE ESSENTIALLY A BLEND OF MAV/MET MOS. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... FRIDAY...THE DAY SHOULD START SUNNY...BEFORE AT LEAST MID LEVEL CLOUDS INCREASE FROM THE SOUTHWEST DURING THE MID TO LATE AFTERNOON. THERE IS SOME QUESTION AS TO WHETHER THE EXTENSIVE LOW CLOUDS CURRENTLY LOCATED ACROSS THE OHIO VALLEY MIGRATES/EXPANDS NE INTO THE REGION DURING THE MORNING...BUT FOR NOW...CURRENT THINKING IS THAT MUCH OF THESE CLOUDS SHOULD REMAIN W OF THE APPALACHIANS AND/OR MIX OUT UPON ADVECTING E. GIVEN A CONTINUED W/SW FLOW...AND AT LEAST SUNSHINE THROUGH THE MORNING...WE EXPECT MAX TEMPS TO REACH SIMILAR LEVELS TO TODAY...WITH 40-45 WITHIN MOST VALLEYS...AND 35-40 ACROSS HIGHER ELEVATIONS...EXCEPT FOR UPPER 20S/MID 30S ACROSS THE HIGHEST ELEVATIONS ACROSS THE S/W ADIRONDACKS. THESE TEMPS ARE A BIT ABOVE A MAV/MET MOS BLEND. OF COURSE...SHOULD CLOUDS DEVELOP SOONER THAN EXPECTED...MUCH COOLER MAX TEMPS WOULD RESULT. WE HAVE INCLUDED SOME SLIGHT CHC TO LOW CHC POPS FOR THE EXTREME WESTERN PORTIONS OF THE REGION TOWARD 00Z/SAT...IN CASE PRECIP DEVELOPS WITHIN STRENGTHENING MID LEVEL FRONTOGENETICAL FORCING. FRI NT-SAT...THE ARCTIC COLD FRONT WILL APPROACH FROM THE NW...HOWEVER MODEL CONSENSUS INDICATES A SLOWER PASSAGE ACROSS THE REGION DURING SAT...AS A SFC LOW PRESSURE WAVE PASSES OFF THE EAST COAST. IN FACT...SOME MODELS...SUCH AS THE NAM...AS WELL AS SEVERAL 12Z/GEFS MEMBERS...HAVE THE SFC LOW TRACKING CLOSER TO THE COAST SAT MORNING...CLOSE ENOUGH TO SPREAD MEASURABLE PRECIP ACROSS MANY AREAS S/E OF ALBANY. WE HAVE ACKNOWLEDGED THIS POSSIBILITY...OR...AT THE VERY LEAST...ENOUGH MID LEVEL F-GEN FORCING TO PRODUCE A STEADIER PERIOD OF MAINLY SNOW ACROSS THE SE CATSKILLS...MID HUDSON VALLEY...NW CT...THE BERKSHIRES AND SOUTHERN VT. IN THIS REGION...EXPECT A GENERAL 1-3 INCHES OF SNOWFALL...HIGHEST FURTHER S/E...WITH ISOLATED 4 INCH AMTS POSSIBLE ACROSS PORTIONS OF EASTERN LITCHFIELD CO. FURTHER N/W...SNOW SHOWERS ASSOCIATED WITH OR AHEAD OF THE COLD FRONT SHOULD LEAD TO GENERAL AMOUNTS OF UP TO ONE INCH. ONCE THE FRONT PASSES THROUGH...NNW WINDS WILL INCREASE...AND MAY PRODUCE AREAS OF BLOWING/DRIFTING SNOW WHERE SNOW SHOWERS PREVIOUSLY OCCURRED. FOR TEMPS...GENERALLY ACCEPTED A MAV/MET MOS BLEND FOR FRI NT...WITH MAINLY 20S TO NEAR 30 ACROSS VALLEY AREAS...AND TEENS ACROSS THE SOUTHERN ADIRONDACKS. FOR SAT MAXES...GIVEN A SLOWER FRONTAL PASSAGE...WE HAVE SIDED CLOSER TO THE MAV MOS IN MOST AREAS...WITH MAXES REACHING THE LOWER/MID 30S...EXCEPT POSSIBLY 35-40 ACROSS THE MID HUDSON VALLEY REGION. SAT NT...FIRST SURGE OF COLD ADVECTION MOVES ACROSS...BEFORE A SECONDARY/REINFORCING COLD FRONT APPROACHES FROM THE NW TOWARD DAYBREAK SUNDAY. AS THE NEXT FRONT APPROACHES...EXPECT SNOW SHOWERS AND POSSIBLE EMBEDDED LAKE EFFECT/ENHANCED SNOWBANDS TO DEVELOP LATE SAT NT...ESP ACROSS THE WESTERN MOHAWK VALLEY AND ADIRONDACKS. EXPECT MINS TEMPS TO FALL INTO THE SINGLE DIGITS AND TEENS IN VALLEYS...WITH SINGLE DIGITS BELOW ZERO ACROSS THE WESTERN ADIRONDACKS. WINDS SHOULD REMAIN BRISK...WHICH MAY LEAD TO WIND CHILLS APPROACHING ADVISORY LEVELS IN PORTIONS OF THE EASTERN CATSKILLS TOWARD DAYBREAK SUNDAY. && .LONG TERM /SUNDAY THROUGH THURSDAY/... BEHIND THE DEPARTING LOW PRESSURE SYSTEM...NW FLOW WILL DEVELOP AS HIGH PRESSURE SETTLES IN OVER THE MISSISSIPPI VALLEY. NW FLOW OVER THE EASTERN GREAT LAKES WILL PRODUCE LAKE EFFECT SNOW SHOWERS ON SUNDAY. 850 HPA TEMPS WILL BE IN THE NEGATIVE TEENS SUNDAY INTO MONDAY...WITH SFC WINDS IN THE 20-30 KT RANGE...ESP IN THE HIGHER TERRAIN...WILL HAVE WIND CHILL VALUES OF -15F TO -20F IN THE ADK SUNDAY AND MONDAY MORNINGS. MOST OTHER AREAS OF HIGH TERRAIN WILL SEE WIND CHILLS OF -10F TO -15F...WITH THE VALLEYS IN THE NEGATIVE SINGLE DIGITS TO SINGLE DIGITS ABOVE 0F. MONDAY NIGHT INTO TUESDAY NIGHT COULD SEE A WEAK TROUGH ASSOCIATED WITH AN UPPER LEVEL CUT OFF LOW EAST OF JAMES BAY. VORT MAX LOOKS TO REMAIN FAR TO OUR NORTH...AS THE SFC TROUGH WEAKENS OVER THE NE US. COULD SEE FEW SHOWERS...MAINLY IN THE FORM OF SNOW...HAVE LOW CHC MAINLY OVER THE HIGHER TERRAIN. AT THIS TIME A SFC LOW WILL DEVELOP OVER THE SE US COAST...WITH THE ECMWF HAVING A MORE PROGRESSIVE TRACK AND SPREADING PRECIP OVER THE SOUTHERN HALF OF THE CWA. GFS ON THE OTHER HAND KEEPS PRECIP MAINLY OUT TO SEA. EITHER WAY...THE SFC LOW DOES NOT STAY NEAR THE COAST FOR LONG AND IS IN THE ATLANTIC BY LATE WEDNESDAY. THIS WILL BE FOLLOWED BY A RIDGE OF HIGH PRESSURE BUILDING OVER THE EASTERN US...BUT EXACTLY WHERE AND HOW STRONG WILL AFFECT THE FCST FOR THE END OF THE WEEK INTO THE WEEKEND. OVERALL TEMPS WILL GO FROM BELOW NORMAL ON SUNDAY TO ABOUT 10 DEGREES ABOVE NORMAL FOR THE REST OF THE PERIOD. THE COLDEST NIGHT WILL BE SUNDAY NIGHT...AND WARMEST DAYS DURING THE MID WEEK. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... HIGH PRESSURE WILL MOVE OFF THE MID ATLANTIC COAST THIS MORNING. A COLD FRONT WILL SLOWLY APPROACH FROM SOUTHERN ONTARIO...AND SOUTHERN QUEBEC DURING THE AFTERNOON INTO THE EVENING. MEANWHILE...LOW PRESSURE MOVING NORTHEAST FROM THE MID ATLANTIC REGION MAY BRING SOME LIGHT SNOW INTO PORTIONS OF EASTERN NY AND NEW ENGLAND SATURDAY MORNING. VFR CONDITIONS WILL DOMINATE FOR MOST OF THE NEXT 24 HOURS. MID AND HIGH CLOUDS WILL BEGIN OVERSPREADING ERN NY IN THE LATE MORNING AND AFTERNOON. THE CLOUDS WILL CONTINUE TO THICKEN AND LOWER AFTER 00Z/SAT WITH CIGS AROUND 5-6 KFT AGL. THE WINDS WILL BE LIGHT TO CALM THIS MORNING...AND THEN BE FROM THE S/SW AT 5-10 KTS DURING THE LATE MORNING AND AFTERNOON...AND LIGHTEN OVERNIGHT FROM THE W/SW AT 7 KTS OR LESS. OUTLOOK... SAT AM-SAT PM...VFR-MVFR. CHC -SN ESPECIALLY LATE AT NT AND SAT AM AT KPOU. SAT NT...MAINLY VFR. SLIGHT CHC -SHSN. SUN...VFR-MVFR. CHC -SHSN AT KALB AND KGFL AND SLIGHT CHC KPOU. SUN NT-MON NT...VFR. NO SIG WX. TUE...VFR/MVFR. CHC -SHSN/-SHRA. && .HYDROLOGY... NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS. LIGHT SNOW/SNOW SHOWERS ARE EXPECTED FRIDAY NIGHT INTO SATURDAY ASSOCIATED WITH AN ARCTIC COLD FRONT. OTHERWISE DRY CONDITIONS WILL PERSIST. SOME GAGES ARE STILL BEING IMPACTED BY ICE ACROSS NORTHERN PORTIONS OF THE HSA. FRIGID TEMPERATURES THIS WEEKEND MAY ALLOW ADDITIONAL ICE FORMATION TO OCCUR LATE SATURDAY INTO EARLY MONDAY...ESPECIALLY ACROSS THE SOUTHERN ADIRONDACKS...AND AREAS NORTH OF THE MOHAWK RIVER VALLEY. 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/KL NEAR TERM...IAA/KL SHORT TERM...KL LONG TERM...KGM AVIATION...WASULA HYDROLOGY...KL/JPV