584 FXUS61 KALY 100953 AFDALY AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 450 AM EST MON JAN 10 2011 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO ONTARIO AND THE GREAT LAKES REGION THROUGH TUESDAY...BEFORE ANOTHER COASTAL STORM IMPACTS THE REGION WITH SNOW TUESDAY NIGHT AND WEDNESDAY. && .NEAR TERM /UNTIL 7 AM THIS MORNING/... AS OF 400 AM....STILL DEALING WITH LAKE EFFECT SNOW SHOWERS AND FLURRIES TO THE NORTH AND WEST OF THE CAPITAL DISTRICT AS WELL AS THE TERRAIN TO THE EAST. HOWEVER... THE ACTIVITY CONTINUES TO SLOWLY DWINDLE AS THE SUBSIDENCE INVERSIONS PREVENT OPTIMAL SNOW GROWTH. ALSO THE FLOW IS SLOWLY BECOMING ANTICYCLONIC AS A SHORT WAVE PULLS AWAY. BOTH FORCES SHOULD CONTINUE THIS TREND INTO TODAY. STILL DEALING WITH A GUSTY NW WIND...MAINLY ACROSS THE HIGHER ELEVATIONS AND MOHAWK VALLEY INTO THE GREATER CAPITAL DISTRICT. OTHER AREAS HAVE SEEN THEIR WIND DIMINISH. STILL DEALING WITH PLENTY OF CLOUDS THOUGH. TEMPERATURES WILL GENERALLY FROM THE UPPER TEENS TO MID 20S THROUGH THE REGION. THROUGH 700 AM...LOOK FOR ANY LAKE EFFECT TO CONTINUE TO VERY SLOWLY DWINDLE BUT STILL COULD ADD DUSTING TO NEARLY AN INCH IN A FEW REMOTE SPOTS. CLOUDS WILL LIKELY DIMINISH A LITTLE AS WELL. TEMPERATURES WILL ONLY A DROP A COUPLE OF POINTS GENERALLY BOTTOMING OUT IN THE TEENS TO AROUND 20. THE WIND WILL CONTINUE ACROSS THE HIGHER TERRAIN/MOHAWK VALLEY INTO THE CD FROM THE NORTHWEST 10 TO 25 MPH...LESSER ELSEWHERE. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/... ASIDE FROM LINGERING LAKE EFFECT MULTIBAND SNOW SHOWER ACTIVITY AND UPSLOPE SNOW SHOWERS...IT WILL BE DRY TODAY. HOWEVER...THAT WIND WILL CRANK UP ACROSS MOST PLACES...GENERALLY TO THE TUNE OF 15 TO 25 MPH. CLOUDS AND SUNSHINE WILL BE MIXED WITH MORE SUNSHINE TO THE LEE OF THE CATSKILLS. BY THE END OF THE DAY...SUNSHINE LOOKS TO PREVAIL IN MOST PLACES. ANY AND ALL SNOW ACTIVITY WILL DIMINISH. THE HIGH TODAY WILL BE MAINLY IN THE 20S...TOUCHING AROUND 30 TO THE SOUTH AND EAST OF ALBANY. WEAK HIGH PRESSURE WILL BUILD TONIGHT THROUGH TUESDAY. THE WIND WILL BECOME LIGHT AND VARIABLE AND ANY REMAINING CLOUD COVER WILL DIMINISH. LOWS TONIGHT...WITH LIGHTER WINDS...MORE CLEARING...AND SNOW PACK...WILL BE AROUND 10 TO LOWER TEENS...AROUND 0 SOUTHERN ADIRONDACKS...LAKE GEORGE AND SARATOGA REGION. HIGHS TUESDAY...WITH INCREASING HIGH CLOUDS AHEAD OF THE NEXT SYSTEM...IN THE 20S. WENT A LITTLE LOWER THAN ALL GUIDANCE DUE TO THE EXISTING STILL RELATIVELY FRESH SNOW PACK. IT NOW APPEARS THAT ANY REAL SNOW WILL HOLD OFF UNTIL TUESDAY NIGHT. THE NEXT SYSTEM...LOOKS TO BE A PHASING OF THE CURRENT GULF COAST SYSTEM...AND NORTHERN STREAM ENERGY CURRENTLY AROUND THE NORTHERN ROCKIES. SOURCES OF GUIDANCE AND ENSEMBLES IN UNUSUALLY GOOD AGREEMENT ON THE PREDICTED LARGE SCALE EVOLUTION OF THE SYSTEM. HOWEVER...THE EXACT TRACK AND MESO-SCALE FEATURES ARE NOT QUITE AS CLEAR CUT ESPECIALLY WHEN ONCE EXAMINES THE LATEST NAM GUIDANCE VERSUS THE OTHER MAJOR WEATHER FORECASTING MODELS. THE GULF COAST SYSTEM HAS ALREADY PRODUCED A LEGACY WINTER STORM ACROSS THE SOUTHEAST ONCE AGAIN...DESPITE BEING A LA NINA WINTER (WHICH CLIMATOLOGICALLY FAVORS RIDGING IN THE SOUTHEAST...CERTAINLY NOT THE CASE THUS FAR THIS WINTER). THE H20 WATER LP DOES INDICATE THAT THE UPPER LEVEL FEATURE WITH THIS STORM IS WEAKENING AS IT PUSHES INTO A CONFLUENT ZONE DOWNSTREAM. HOWEVER...THERE IS LOTS OF CONVECTION NOTED OFF THE GULF BEACHES OF WESTERN FLORIDA. MSAS INDICATED PRESSURE RISES TO THE LEE OF THE UPPER SYSTEM INDICATING SURFACE WEAKENING. HOWEVER...PRESSURE FALLS NOTED OFFSHORE THE CAROLINAS INDICATIVE THE SURFACE LOW SHOULD "JUMP" OFFSHORE LATER ON TODAY. IT WILL THEN AWAIT A MUCH STRONGER PIECE OF VORTICITY...RAPIDLY SPIRALING OFF A GIANT UPPER AIR LOW PARKED OVER MONTANA THIS MORNING. THIS NEW VORTICITY LOBE WILL JOIN FORCES WITH DEEP GULF MOISTURE AND POTENTIAL VORTICITY OFF THE SOUTHERN STREAM SYSTEM. THIS ADDED VORTICITY WILL BE LIKE A FUSE NEEDING TO BE RE-LIT. EVENTUALLY...LOW PRESSURE WILL EMERGE OFF THE CAROLINAS...WITH THE GULF STREAM AND THERMAL GRADIENT BAROCLINICITY LIGHTING THE FUSE. THE NORTHERN STREAM UPPER ENERGY AND DYNAMICS COULD SUPPORT SOME ENSUING CONVECTIVE...GENERATING CYCLOGENESIS. THUS FAR...THE NAM HAS LATCHED ONTO A PRETTY POTENT STORM TRACKING UP ALONG THE EASTERN SEABOARD...PERHAPS INDUCED BY CONVECTION BUILDING A RIDGE UPSTREAM TO THE EAST. THE FGEN IS QUITE AMAZING AS IT LINES UP INTO OUR SOUTHEASTERN ZONE FROM THE COAST...WITH GOOD DEFORMATION. THROUGH DUCTING...STRONG UPWARD MOTION UP TO 20 MICROBARS/S IS EVIDENT RIGHT INTO THE CAPITAL DISTRICT. ALSO...THE BEST ASCENT CONTINUES TO BISECT THE -12 TO -18C ISOTHERM...THE FAVORABLE REGION FOR SNOW GROWTH. INDEED...IF THIS SCENARIO WORKS...LOOK OUT! WE COULD BE TALKING ABOUT A SNOWSTORM FOR THE RECORD BOOKS WITH A MESO-SCALE BOUND CAPABLE OF PRODUCING BLINDING SNOWFALL RATES > 2 INCHES PER HOUR AT TIMES AND POSSIBLY EVEN SOME THUNDER SNOW. HOWEVER...BEFORE GETTING TOO EXCITED...THIS INWARD TUCK IS NOT SUPPORTED BY ANY OTHER OPERATIONAL MODELS AS WELL AS THE GEFS. IN FACT...THE GEFS ARE "CLUSTERED" UNDER A HALF INCH OF QPF FOR ALBANY WHICH WOULD IMPLY ADVISORY LEVEL SNOW OR VERY LOW END WARNING FOR THE IMMEDIATE CAPITAL DISTRICT. THE GFS/ENSEMBLES/ECMWF AND GEM ALL TRACK THE STORM CONSIDERABLY FURTHER EAST WELL EAST OF THE FIRE ISLAND/CAPE COD BENCHMARK. THIS HAS BEEN THE PREFERRED TRACK THUS FAR THIS WINTER. HAS THE NAM LATCHED ONTO THE IDEA OF CONVECTION BUILDING THE RIDGE UPSTREAM? QUITE POSSIBLY...BUT THE NAM IS OFTEN NOT AS RELIABLE MORE THAN 48 HOURS OUT DUE TO EXTREMELY SMALL SCALE RESOLUTION. THE OVERALL SYNOPTIC SET UP INCLUDES AN UPPER AIR LOW QUICKLY TRANSLATING EASTWARD ACROSS OUR REGION AS THE SURFACE STORM COMES UP ALONG OR OFF THE COAST. GIVEN THIS ANTICIPATED AND THE FACT THAT THE TRACK THIS WINTER FOR COASTALS HAS BEEN MORE EASTWARD (IE WHY COASTAL NEW JERSEY HAS HAD THE LION SHARE OF THE SNOW THIS WINTER THUS FAR...AS OPPOSED TO FURTHER INLAND)...WE ARE FAVORING THE MORE EASTWARD TRACK. ONE LAST THING TO CONSIDER EVEN THE SREFS ARE NOT NEARLY AS CLUSTERED AS THE GEFS...ALL OVER THE PLACE WITH QPFS RANGING FROM A QUARTER OF AN INCH TO WELL OVER THE INCH...SO NOT A TREMENDOUS AMOUNT OF CONFIDENCE IN THE NAM TRACK. BOTTOM LINE...NOT ENOUGH CONFIDENCE TO GO WITH SUCH AN INSIDE TRACK. SINCE THIS EVENT MIGHT NOT UNFOLD UNTIL WEDNESDAY...WE DECIDED TO HOLD OFF ANY WATCHES AND WAIT TO SEE IF THERE IS BETTER AGREEMENT WITH THE NAM (COMPARED TO THE OTHER MAJOR MODELS) LATER TODAY. AS WE HEAD CLOSER TO THE EVENT...IF THE NAM CONTINUES TO SHOW THIS INWARD JAUNT IT SHOULD BE WEIGHED MORE INTO THE OVERALL THINKING. FOR NOW AGAIN...LEANED MORE WITH THE OTHER MODELS OFFERING A MORE PROGRESSIVE AND EASTWARD TRACKING STORM. HAVING SAID THAT...IT STILL APPEARS THAT WE COULD BE IN FOR SIGNIFICANT SNOWSTORM TO THE SOUTHEAST OF ALBANY...HIGH END ADVISORY (OR LOW WARNING SNOWFALL) ACROSS THE GREATER CAPITAL DISTRICT...AND LESSER AMOUNTS THE FURTHER NORTH AND WEST ONE GETS FROM THE STORM. THIS STORM WILL BE A BIT QUICKER THAN THE LAST ONE (ABOUT 18 HOURS). LIQUID SNOW TO WATER RATIOS LOOK TO START OFF A BIT HIGHER THAN THE LAST STORM (12:1) AS INITIALLY WE ARE IN THE WARM AIR PROCESS OF ISENTROPIC LIFT. HOWEVER...AS THE STORM PROGRESSES AND THE UPPER AIR LOW DYNAMICALLY COOLS THE COLUMN WE INCREASED THE RATIOS TO 15:1 BY WEDNESDAY MORNING AND UP TO 20:1 AS THE STORM DEPARTS LEAVING A TRAILING DEFORMATION BEHIND BY WEDNESDAY AFTERNOON. LOOK FOR THE SNOW TO DEVELOP FROM SOUTH TO NORTH LATER TUESDAY NIGHT AND CONTINUE INTO THE FIRST HALF OF WEDNESDAY BEFORE TAPERING TO FLURRIES OR SNOW SHOWERS BY LATE IN THE DAY. IN ADDITION...THE WIND WILL PICK UP ON WEDNESDAY...FIRST OVER THE HILLS...THEN INTO THE HUDSON VALLEY AND MOHAWK VALLEYS BY AFTERNOON. AT THIS POINT...THE WINDS DO NOT APPEAR STRONG ENOUGH DURING THE SNOWSTORM FOR ANY MAJOR PROBLEMS. HOWEVER...IF THE NAM IS RIGHT WITH ITS CLOSER TUCKING AND MORE RAPIDLY DEEPENING STORM...WIND COULD BECOME MORE OF AN ISSUE. THE OTHER COMPLICATING FACTOR WITH THIS STORM IS THE FACT THAT INITIALLY THERE WILL BE "BATTLE" OVER THE INLAND OHIO SURFACE STORM (STRONGER DYNAMICS ALOFT BUT WEAKER AT THE SURFACE) VERSUS THE WEAKER DISTURBANCE ALOFT AND SLIGHTLY STRONGER COASTAL STORM THAT WILL BECOME THE MAIN PLAYER. IF THIS PROCESS TAKES LONGER THAN WE BELIEVE...THAT COULD IMPACT SNOW ACCUMULATIONS SOME. AT LEAST WE KNOW ALL SNOW WILL FALL ACROSS OUR ENTIRE REGION. TEMPERATURES WILL REMAIN AT OR BELOW FREEZING THROUGHOUT THE COLUMN DURING THE WHOLE EVENT...MAINLY IN THE 20S. BY WEDNESDAY NIGHT ANY LEFTOVER SNOW SHOWERS WILL BE CONFINED THE HIGHER TERRAIN THROUGH UPSLOPE PROCESSES WORKING ON ANY LOW LEVEL LEFTOVER MOISTURE. TEMPERATURES LOOK TO FALL BACK INTO THE TEENS. ...STAY TUNED... && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... THE PERIOD STARTS OUT WITH THE NOR'EASTER CONTINUING TO HEAD OUT TO SEA. OTHERWISE...A FAIRLY FLAT WNW FLOW ALOFT WILL SET UP FROM THE GREAT LAKES INTO THE NORTHEAST...BUT WITH EMBEDDED WEAK SHORTWAVE TROFS MOVING THROUGH IT. THIS WILL RESULT IN SCATTERED SNOW SHOWERS ACROSS THE REGION...PRIMARILY WEST OF THE HUDSON VALLEY...THURSDAY THROUGH FRIDAY. A SURFACE HIGH AND SOME RIDGING ALOFT WILL PRODUCE A BRIEF DRY PERIOD FRIDAY NIGHT INTO EARLY SATURDAY. A SURFACE LOW AND ASSOCIATED UPPER LOW MOVING EASTWARD ACROSS SOUTHERN CANADA WILL BRING A SWATH OF MOISTURE INTO THE REGION SATURDAY AFTERNOON AND NIGHT...AHEAD OF A COLD FRONT. THE COLD FRONT AND SWATH OF MOISTURE WILL DEPART THE REGION ON SUNDAY. DESPITE THE TRACK OF THIS LOW AND THE SOUTHERLY FLOW AHEAD OF THE COLD FRONT...EXPECT ATMOSPHERE TO REMAIN COLD ENOUGH TO FORECAST ONLY SNOW WITH THIS EVENT. HIGHS THURSDAY WILL BE 20 TO 30...FRIDAY IN THE UPPER TEENS AND 20S...SATURDAY IN THE 20S...AND UPPER TEENS TO LOWER 30S ON SUNDAY. LOWS THURSDAY NIGHT WILL BE IN THE SINGLE NUMBERS TO MID TEENS... FRIDAY NIGHT GENERALLY BETWEEN ZERO AND 10 ABOVE...AND SATURDAY NIGHT IN THE UPPER SINGLE NUMBERS AND TEENS. && .AVIATION /09Z MONDAY THROUGH FRIDAY/... STRONG LOW PRESSURE MOVING INTO THE CANADIAN MARITIMES WILL MAINTAIN A BRISK NORTHWEST FLOW ACROSS THE KGFL/KALB/KPOU TAF SITES THROUGH MOST OF MONDAY AFTERNOON...THEN WEAK HIGH PRESSURE WILL BUILD INTO THE REGION AND WINDS WILL BECOME LIGHT. MAINLY A VFR BKN/OVC CU/SC CLOUD DECK WILL BE OVER THE KGFL/KALB TAF SITES INTO MONDAY AFTERNOON...WITH FEW/SCT CLOUDS AT KPOU. AT KALB THE CLOUD DECK WILL BE HOVERING RIGHT AT THE VFR/MVFR THRESHOLD OF 3000 FEET THROUGH ABOUT 14Z THIS MORNING...THEN VFR AFTER THAT. BY SUNSET AND BEYOND...EXPECT CONDITIONS TO BE MAINLY P6SM SKC. WINDS WILL BE WEST TO NORTHWEST AT KALB/KPOU FOR THE REST OF THE NIGHT...GENERALLY 10 KTS OR LESS AT KPOU...BUT 10 TO 12 KTS AT KALB WITH GUST TO OVER 20 KTS. AT KGFL THE WINDS WILL BE LIGHT AND VARIABLE FOR THE REST OF THE NIGHT. BY 14Z THE WEST TO NORTHWEST WINDS WILL PICK UP TO 10 TO 15 KTS AT ALL THREE TAF SITES...WITH GUSTS OF 15 TO 20 KTS AT KGFL/KPOU...AND AROUND 25 KTS AT KALB. AFTER 22Z-23Z...SURFACE WINDS WILL DECREASE TO UNDER 10 KTS AND EVENTUALLY BECOME LIGHT AND VARIABLE MONDAY NIGHT. OUTLOOK... LATE MON NT-TUE...VFR. NO SIG WX. TUE NGT-WED...MVFR/IFR...-SN/SN LIKELY WITH CHC +SN. THU-FRI...VFR. NO SIG WX. && .HYDROLOGY... TEMPERATURES ARE EXPECTED TO REMAIN BELOW FREEZING THROUGH MOST OF NEXT WEEK. ICE WILL CONTINUE TO THICKEN ON MAIN STEM RIVERS OVER THE NEXT SEVERAL DAYS ALTHOUGH SNOW COVER ON TOP OF THE ICE MAY SLOW THE RATE OF INCREASE IN ICE THICKNESS. OUTSIDE OF SOME UPSLOPE SNOW SHOWERS...THE NEXT ROUND OF PRECIPITATION WILL BE TUESDAY NIGHT INTO WEDNESDAY BUT ONCE AGAIN THIS PRECIPITATION WILL BE IN THE FORM OF SNOW. 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...HWJIV NEAR TERM...HWJIV SHORT TERM...HWJIV/NAS LONG TERM...GJM AVIATION...GJM HYDROLOGY...HWJIV/NAS/JPV