000 FXUS61 KBTV 112342 AFDBTV AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 642 PM EST MON FEB 11 2008 .SYNOPSIS... A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT...AND REMAIN OVER THE AREA THROUGH TUESDAY MORNING. AN AREA OF LOW LOW PRESSURE WILL MOVE ACROSS THE OHIO VALLEY TUESDAY...AND THEN PASS OFF THE COAST OF SOUTHERN NEW ENGLAND ON WEDNESDAY. THIS LOW PRESSURE SYSTEM HAS THE POTENTIAL TO BRING SOME HEAVY SNOW TO THE NORTH COUNTRY TUESDAY NIGHT THROUGH WEDNESDAY MORNING. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 633 PM EST MONDAY...BASED ON SATELLITE TRENDS...SKIES HAVE CLEARED CONSIDERABLY ACROSS THE AREA. THUS THREAT FOR MOSTLY CLOUDY CONDITIONS AND/OR FLURRIES HAS COME TO AN END AND WILL REMOVE FROM THE FORECAST TONIGHT. WILL GO WITH MAINLY A MOSTLY CLEAR SKY. WITH DECREASING WINDS...TEMPERATURES SHOULD FALL SHARPLY AND GOING FORECAST OF TEMPERATURES FALLING BELOW ZERO OVERNIGHT LOOKS REAL GOOD. SHOULD SEE PLENTY OF ZERO TO 10 BELOW WITH 10 TO 20 BELOW IN THE MOUNTAINS. NO OTHER CHANGES NEEDED AT THIS TIME. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 420 PM EST MONDAY...LOW PRESSURE AREA WILL MOVE FROM THE MISSISSIPPI VALLEY INTO THE OHIO VALLEY ON TUESDAY. THE WEAK SFC LOW WILL MOVE INTO CNTRL PA/NY LATE TUE NITE...REDEVELOP ALONG SRN NEW ENG COAST WED...AND THEN MOVE SLOWLY OFFSHORE. MODELS IN GOOD AGREEMENT WITH THE LOW TRACK...AND WITH TIMING OF ONSET OF PCPN. EXPECT SNOW TO MOVE INTO THE SOUTHERN PORTION OF THE FORECAST AREA LATE TUESDAY AFTERNOON AND RAPIDLY OVERSPREAD THE REST OF FORECAST AREA FROM SOUTHWEST TO NORTHEAST TUESDAY EVENING. EXPECTING A SIGNIFICANT OVERRUNNING EVENT TO OCCUR ACRS THE FA TUE NITE. WITH ARCTIC AIRMASS IN PLACE TUESDAY...AND UPPER FLOW BACKING IN RESPONSE TO VIGOROUS/DIGGING SHRTWV OVER THE GRTLKS...LOOK FOR EXCELLENT MSTR ADVECTION FROM OH VLY AND MID ATLC RGN INTO THE NORTHEAST. HEAVIEST PCPN WILL OCCUR IN ABOUT A 6 HR PERIOD TUES NITE WHEN ISENTROPIC LIFT IS GREATEST. MID LEVEL WARMING IS SIGNIFICANT...AND MAY RESULT IN A MIX WITH SLEET/FZRA OVER SRN ZONES...THE SAME AREA WHERE QPF WILL BE GREATEST. AT PRESENT TIME...EXPECTING QPF TO RANGE FROM A HALF INCH TO AN INCH ACRS THE AREA...WITH THE LOWER AMOUNTS FAR NORTH AND THE HIGHEST AMTS OVER SC VT. HOWEVER...STILL SOME UNCERTAINTY REGARDING QPF AND HOW MUCH MIXING WILL OCCUR...SO HAVE CONTD WITH WINTER STORM WATCH AT THIS TIME. ANY LINGERING SNOW SHWRS WILL END WED EVENING AS THE LOW MOVES FURTHER OFFSHORE AND HIGH PRESSURE BUILDS EAST FROM THE GRTLKS ALLOWING FOR SOME PARTIAL CLRNG. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 420 PM EST MONDAY...THE EXTENDED PERIOD WITH CONT TO BE VERY ACTIVE WITH A SHOT OF ARCTIC AIR ON SATURDAY...FOLLOWED BY ANOTHER STORM LATE SUNDAY INTO MONDAY. THIS PATTERN WL BE VERY SIMILAR TO OUR CRNT SITUATION WITH ARCTIC AIR IN PLACE TODAY...FOLLOWED BY A MODERATE PRECIP EVENT FOR TUES INTO WEDS...WE WL HAVE A REPEAT PERFORMANCE OF THIS PATTERN THIS UPCOMING WEEKEND. THE OVERALL PATTERN WL FEATURE A QUASI-STATIONARY MID/UPPER LVL TROF ACRS THE HUDSON BAY REGION WITH EMBEDDED NORTHERN AND SOUTHERN STREAM ENERGY PIECES MOVING ACRS THE EASTERN CONUS EVERY COUPLE OF DAYS...IN THE PROGRESSIVE FLW ALOFT. IN ADDITION...THIS PATTERN WL FEATURE ONE QUICK SHOT OF ARCTIC AIR LATE FRIDAY INTO SATURDAY...WHICH COULD BE ACCOMPANIED BY SNOW SHOWERS AND SQUALLS...VERY MUCH LIKE YESTERDAY. WAA AHEAD OF THIS SYSTEM WL PUSH 85H TEMPS BTWN -6 AND -8C BY 18Z FRIDAY...COMBINED WITH 925MB TEMPS NEAR -4C...SUPPORTS HIGHS IN THE U20S TO M30S MOST LOCATIONS. MEANWHILE...STRONG SFC BOUNDARY WITH GOOD LLVL CONVERGENCE...SOME LAKE MOISTURE INTERACTION...AND GOOD RIBBON OF 850-500MB MOISTURE...WL HELP TO ENHANCE SNOW SHOWERS ACTIVITY LATE FRIDAY INTO EARLY SATURDAY. OVERALL ACCUMULATIONS WL BE LIGHT WITH HIGHEST AMOUNTS ACRS THE MTN LOCATIONS. SATURDAY...925MB TEMPS FALL BTWN -20 AND -24C WITH 85H TEMPS AROUND -22C...WITH A BRISK NW WIND...VERY SIMILAR TO TODAY...WHICH WOULD SUPPORT SINGLE DIGITS MTNS TO L/M TEENS ELSEWHERE. THIS WL BE FOLLOWED BY BRIEF SFC HIGH PRES AND DRY WEATHER FOR SATURDAY INTO EARLY SUNDAY...BEFORE SOUTHERN STREAM ENERGY/MOISTURE IS PULLED NORTH TWD THE MID ATLANTIC STATES LATE SUNDAY INTO MONDAY. THIS SYSTEM WL ONCE AGAIN HAVE PLENTY OF MOISTURE TO WORK WITH...ESPECIALLY ASSOCIATED WITH SUB-TROPICAL JET. HOWEVER...STILL PLENTY OF QUESTIONS ABOUT AMOUNT OF NORTHERN/SOUTHERN STREAM PHASING AND EXACT TRACK OF SFC LOW PRES. FEEL LIKE THIS SYSTEM WL TAKE THE TRACK OF MANY SYSTEMS THIS PAST WINTER...WITH PRIMARY SFC LOW TRACKING CLOSER TO THE MID/UPPER LVL SUPPORT ACRS THE CENTRAL PLAINS INTO THE EASTERN GREAT LAKES...THEN SECONDARY DEVELOPMENT WL OCCUR AS SOUTHERN STREAM ENERGY INTERACTIONS WITH DIGGING FULL LATITUDE TROF OVER THE EASTERN CONUS...AND SFC LOW DEVELOPS OVER THE EASTERN MID ATLANTIC STATES. THIS SCENARIO WOULD PRODUCE A 4 TO 8 HR WINDOW OF MODERATE SNOW ASSOCIATED WITH STRONG LOW TO MID LVL WAA...THEN A BRIEF LULL FOLLOWED BY SOME WRAP AROUND MOISTURE ON MONDAY. STILL PLENTY OF DAYS TO FINE TUNE THE FCST...BUT A MODERATE PRECIP EVENT IS LIKELY LATE SUNDAY INTO MONDAY WITH SLIGHTLY ABOVE NORMAL TEMPS EXPECTED. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... THROUGH 00Z WEDNESDAY...VFR CONDITIONS WILL PREVAIL ACROSS ALL TAF SITES THROUGH THE NEXT 24 HOURS. SATELLITE TRENDS INDICATE SKIES HAVE BECOME CLEAR ACROSS THE FORECAST AREA AS HIGH PRESSURE HAS SETTLED INTO THE REGION. SKIES SHOULD REMAIN CLEAR THROUGH 18Z TUESDAY...THEN UPPER LEVEL MOISTURE INCREASES FROM SOUTHWEST TO NORTHEAST ACROSS OUR TAF SITES WITH SCATTERED CIRRUS MOVING IN AHEAD OF NEXT SYSTEM. 00Z WEDNESDAY THROUGH SATURDAY...THE EXTENDED AVIATION CONCERN WL BE IMPACTS OF SYSTEM LATE TUES INTO WEDS AND ASSOCIATED MODERATE TO HEAVY BAND OF SNOW. GIVEN...STRONG 2D FGEN FORCING BTWN 850-700MB....GOOD DEEP 850-500MB MOISTURE...AND STRONG Q-VECTOR CONVERGENCE LIFTING FROM SOUTH TO NORTH ACRS OUR TAF SITES...EXPECT A 4 TO 6 HR WINDOW OF MODERATE TO HEAVY SNOW BTWN 06Z AND 18Z ON TUES NIGHT INTO WEDS MORNING. THIS WL CAUSE SIGNIFICANT IMPACTS TO AVIATION WITH VLIFR TO LIFR DURING THE HEAVY PRECIP PERIOD. OTHERWISE...PRECIP SHIELD WL QUICKLY SHIFT EAST AND NORTH OF TAF SITES BY 00Z THURS...WITH SOME WRAP AROUND MOISTURE POSSIBLE...CREATING IFR CONDITIONS ACRS THE MTN LOCATIONS. VFR CONDITIONS WL DEVELOP WEDS NIGHT AND CONT INTO FRIDAY WITH SFC HIGH PRES OVERHEAD. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR VTZ001>012-016>019. NY...WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR NYZ026>031-034-035-087. && $$ SYNOPSIS...RJS NEAR TERM...EVENSON SHORT TERM...RJS LONG TERM...TABER AVIATION...TABER/LAHIFF