BOF 000 FXUS61 KBOX 101835 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 135 PM EST FRI FEB 10 2012 .SYNOPSIS... HIGH PRESSURE WILL BRING ONE MORE DRY AND MILD DAY TODAY. LOW PRESSURE WILL TRACK SOUTHEAST OF NANTUCKET...LIKELY BRINGING ACCUMULATING SNOWS TO MOST OF THE REGION ON SATURDAY. AN ARCTIC FRONT WILL USHER IN A BRIEF SHOT OF VERY COLD AIR SUNDAY AND SUNDAY NIGHT. HIGH PRESSURE BUILDING SOUTH OF THE REGION WILL BRING A RETURN TO MODERATING TEMPERATURES EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 130 PM UPDATE...MADE MINOR CHANGES TO TEMPERATURES AND ESPECIALLY DEWPOINTS TO BRING IN LINE WITH CURRENT TRENDS. OTHERWISE...THE FORECAST IS ON TRACK. PREVIOUS DISCUSSION... A RIDGE OF HIGH PRESSURE OVER THE REGION WILL PROVIDE ONE MORE DAY OF UNSEASONABLY MILD TEMPERATURES. PLENTY OF SUNSHINE AND A WELL MIXED/DRY ATMOSPHERE SHOULD ALLOW FOR A QUICK RECOVERY FROM THIS MORNING/S COLD START IN THE OUTLYING LOCATIONS. THE INCREASING FEBRUARY SUN ANGLE WILL ALSO HELP AND PUSH HIGHS INTO THE LOWER TO MIDDLE 40S ACROSS THE INTERIOR HIGH TERRAIN...AND FROM THE UPPER 40S TO AROUND 50 ON THE COASTAL PLAIN. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... ***ACCUMULATING SNOW EXPECTED ACROSS MOST OF THE REGION ON SATURDAY*** TONIGHT... AN APPROACHING SHORTWAVE WILL RESULT IN CYCLOGENESIS OFF THE NORTH CAROLINA COAST. WHILE MUCH OF THE EVENING SHOULD GENERALLY BE DRY...WE WILL LIKELY SEE SOME LIGHT PRECIPITATION DEVELOP FROM SOUTH TO NORTH FROM LATE EVENING AND PARTICULARLY TOWARD DAYBREAK SUNDAY. MODEL SOUNDINGS INDICATE THAT MOST OF THE REGION SHOULD BE COLD ENOUGH FOR LIGHT SNOW. THE EXCEPTION MIGHT BE THE VERY IMMEDIATE SOUTH COAST...AND ESPECIALLY CAPE/ISLANDS WHERE BOUNDARY LAYER WILL BE WARM ENOUGH TO SUPPORT LIGHT RAIN. MOST OF THIS PRECIPITATION OVERNIGHT WILL BE GENERATED FROM BROAD MID LEVEL LIFT AND NOT FROM THE DEVELOPING COASTAL STORM. THEREFORE...EXPECT THE SNOW TO BE LIGHT WITH ANY ACCUMULATIONS AN INCH OR LESS THROUGH 12Z SUNDAY. SATURDAY... DEVELOPING LOW PRESSURE OFF THE CAROLINA COAST WILL LIFT NORTHEAST AS IT INTENSIFIES. MODEL CONSENSUS TAKES THE LOW PRESSURE SYSTEM SOUTHEAST OF THE BENCHMARK...WHICH IS FURTHER SOUTHEAST THAN WE NORMALLY LIKE TO SEE FOR A MAJOR SNOWSTORM ACROSS MOST OF SOUTHERN NEW ENGLAND. WHILE WIDESPREAD 6+ INCH AMOUNTS CAN/T BE RULED OUT IF THE LOW ENDS UP TRACKING FURTHER NORTHWEST THAN EXPECTED...THIS SEEMS TO BE A LOW PROBABILITY AT THIS POINT. THEREFORE...NO WATCHES WILL BE ISSUED AT THIS TIME. NONETHELESS...WE DO EXPECT THE LOW PRESSURE SYSTEM TO TRACK CLOSE ENOUGH TO GIVE MOST OF THE AREA SOME ACCUMULATING SNOW ESPECIALLY IN RHODE ISLAND/SOUTHEAST MA. THERE CERTAINLY IS ENOUGH MID LEVEL LIFT/BAROCLINICITY TO WARRANT CATEGORICAL POPS FOR PRECIPITATION FOR MOST AREAS. MOST OF OUR REGION WILL BE COLD ENOUGH FOR SNOW...EXPECT PERHAPS THE VERY IMMEDIATE SOUTH COAST FOR A TIME AND ESPECIALLY THE OUTER-CAPE/NANTUCKET WHERE BOUNDARY LAYER WILL BE WARM ENOUGH FOR RAIN AT LEAST PART OF THE DAY. AS FOR SNOW ACCUMULATIONS THEY ARE TRICKY AS USUAL. WHILE MOST OF THE REGION WILL BE COLD ENOUGH FOR SNOW...PORTIONS OF THE LOWER ELEVATIONS AND ESPECIALLY THE COASTAL PLAIN MAY BE NEAR OR EVEN A DEGREE OR SO ABOVE FREEZING. IF THE SNOW IS NOT FALLING MODERATE TO HEAVY IT MAY HAVE A TOUGH TIME ACCUMULATING ESPECIALLY ON THE ROADWAYS WITH THE FEBRUARY SUN ANGLE. NOW THE GFS/NAM DO SHOW A PERIOD OF PRETTY GOOD SNOW GROWTH/LIFT IN THE VICINITY OF THE I-95 CORRIDOR AND POINTS SOUTH AND EAST FROM THE LATE MORNING INTO THE AFTERNOON. THIS IS WHEN WE THINK MOST OF THE SNOW ACCUMULATIONS WILL OCCUR WITH THE POTENTIAL FOR LOCALIZED BANDING. OUR BEST SHOT AT SNOW ACCUMULATIONS RIGHT NOW IS FOR 1 TO 2 INCHES OF SNOW ACROSS SOUTHERN NH/WESTERN MA...2 TO 4 INCHES OVER PARTS OF EASTERN CT/MUCH OF CENTRAL AND EASTERN MA...AND LESS ON THE CAPE/ISLANDS WHERE MUCH OF THE PRECIPITATION MAY FALL AS RAIN. HOWEVER...PORTIONS OF RHODE ISLAND/SOUTHEAST MA MAY SEE A SWATH OF 3 TO 6 INCHES. THIS WILL BE DEPENDENT ON ANY LOCALIZED BANDING THAT SETS UP. THE MODELS INDICATE A PERIOD OF DECENT SNOW GROWTH IN THIS REGION...SO WILL HAVE TO KEEP AN EYE ON THIS REGION. SINCE THIS EVENT IS MAINLY IN THE THIRD PERIOD...HELD OFF ON HEADLINES... BUT WINTER WEATHER ADVISORIES WILL LIKELY BE NEEDED FOR AT LEAST A PORTION OF THE REGION. WHILE THE ABOVE SNOWFALL TOTALS ARE OUR MOST LIKELY SCENARIO...A SHIFT IN TRACK WOULD ALTER THOSE NUMBERS. AS MENTIONED EARLIER...A SWATH OF 6+ INCH AMOUNTS APPEARS TO BE A LOW PROBABILITY BUT STILL CAN/T BE RULED OUT ACROSS EASTERN CT/RHODE ISLAND/SOUTHEAST MA IF THE TRACK SHIFTS TO THE NORTHWEST. THERE ALSO IS A LOW PROBABILITY THAT THE TRACK SHIFTS FURTHER SOUTH AND EAST...LIMITING AMOUNTS TO 1 TO 2 INCHES ACROSS MOST OF THE REGION. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... OVERVIEW... MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT INTO EARLY NEXT WEEK...THEN TIMING AND TRACK ISSUES OF WEATHER SYSTEMS COME BACK INTO PLAY THANKS TO A SPLIT UPPER LEVEL FLOW CAUSING WIDE VARIANCE OF SOLUTIONS BY THE MIDDLE OF NEXT WEEK. HOWEVER...IT APPEARS THAT THERE IS DECENT AGREEMENT THAT MILDER CONDITIONS WILL RETURN EARLY NEXT WEEK AS HIGH PRESSURE BUILDS ACROSS THE MID ATLC AND SE U.S. WITH MAINLY DRY WEATHER. MAY SEE A BRIEF WEAK SYSTEM PASS ACROSS THE REGION AROUND MID WEEK THAT MAY BRING LIGHT PRECIPITATION. SATURDAY NIGHT...BACK EDGE OF PRECIP FROM DEPARTING STORM WILL LINGER ACROSS EASTERN AREAS...SO CONTINUED WITH CHANCE TO LIKELY POPS ACROSS CENTRAL-E MA/RI WHICH SHOULD EXIT MOST AREAS BY AROUND MIDNIGHT. MAY CONTINUE TO LINGER ACROSS THE CAPE AND ISLANDS THROUGH A GOOD PORTION OF THE NIGHT...BUT SHOULD BE ONLY LIGHT ACCUMULATIONS. TEMPS WILL ALSO DROP BACK TO THE SINGLE DIGITS AND TEENS AS THE ARCTIC FRONT STARTS TO APPROACH S NH EARLY SUN MORNING. SUNDAY...ARCTIC AIR WILL WORK IN DURING SUNDAY...USHERED IN BY INCREASING N-NW WINDS. WILL SEE SOME CLOUDS DEVELOP WITH THE COLDER AIR AS WELL...BUT THIS IS A DRY FRONT WITH JUST THE WIND SHIFT AND COLD AIR. H85 TEMPS NOT QUITE AS COLD AS PREVIOUS FORECASTS AS CORE OF THE COLDEST AIR REMAINS ACROSS NORTHERN NEW ENGLAND. STILL IMPRESSIVE WITH -14C TO -17C ARRIVING SUNDAY NIGHT. WINDS WILL CONTINUE TO STIR SUNDAY NIGHT AS WELL...SO WILL SEE BITTER WIND CHILL VALUES ESPECIALLY ACROSS THE HIGHER TERRAIN OF S NH/N CENTRAL AND WESTERN MA. MAY NEED WIND ADVISORIES DURING THE DAY ESPECIALLY ALONG THE COAST...CAPE COD AND THE ISLANDS...AS WELL AS WIND CHILL ADVISORIES SUN NIGHT. MONDAY-TUESDAY...ARCTIC AIR WILL QUICKLY RETREAT AS NEARLY ZONAL UPPER FLOW RETURNS. EXPECT HIGH PRES TO PASS S OF NEW ENGLAND WITH MILDER AIR RETURNING BY TUESDAY. WARM FRONT AND WEAK WAVE OF LOW PRES MAY BRING SCT SHOWERS TUESDAY NIGHT...THOUGH NOT A LOT OF CONFIDENCE ON TIMING AND TRACK DUE TO WIDENING MODEL SOLUTIONS AT THIS TIMEFRAME. WEDNESDAY-THURSDAY...MODELS HAVE WIDE VARIANCE IN THEIR SOLUTIONS...SO NOT A WHOLE LOT OF CONFIDENCE WITH THIS PORTION OF THE FORECAST. FOR NOW...HAVE CONTINUED DRY AND MILD CONDITIONS. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT MODERATE...30 PERCENT TO 60 PERCENT HIGH...GREATER THAN 60 PERCENT THROUGH 06Z...HIGH CONFIDENCE. VFR. 06-12Z TONIGHT...MODERATE TO HIGH CONFIDENCE. MVFR CONDITIONS WILL START TO DEVELOP FROM SOUTH TO NORTH AS LIGHT SNOW OVERSPREADS THE REGION. LOWER CONFIDENCE ON TIMING. SATURDAY...HIGH CONFIDENCE. WIDESPREAD IFR/MVFR CONDITIONS IN SNOW. EXCEPTION MAY BE THE OUTER CAPE/ISLANDS WHERE RAIN IS POSSIBLE FOR A TIME. NORTHERLY WINDS WILL GUST BETWEEN 25 AND 30 KTS ON THE CAPE AND ISLANDS SATURDAY EVENING. KBOS TERMINAL...HIGH CONFIDENCE IN TAF CONDITIONS...LOW TO MODERATE CONFIDENCE FOR TIMING. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT...MODERATE CONFIDENCE. WILL SEE LEFTOVER MVFR-IFR CIGS/VSBYS MAINLY ACROSS CENTRAL AND EASTERN AREAS EARLY AS LOW PRES EXITS. SHOULD SEE CONDITIONS IMPROVING TO VFR BY AROUND MIDNIGHT... THOUGH MVFR MAY LINGER ON THE CAPE AND ISLANDS THROUGH MOST OF THE NIGHT. NW WINDS PICK UP...GUSTING TO 20-25 KT...POSSIBLY UP TO 30-35 KT ON THE OUTER CAPE AND NANTUCKET AFTER MIDNIGHT. SUNDAY...MODERATE CONFIDENCE FOR MAINLY VFR CIGS. NW GUSTS UP TO 30 KT...MAY BE A BIT HIGHER ON THE OUTER CAPE AND NANTUCKET SUN NIGHT WITH ARCTIC AIR WORKING IN. MONDAY AND TUESDAY...MODERATE TO HIGH CONFIDENCE FOR VFR. LOWERING CONDITIONS POSSIBLE BY TUE NIGHT IN DEVELOPING LIGHT SNOW OR MIXED RAIN/SNOW. && .MARINE... TODAY...SOUTHWEST WINDS OF 10 TO 15 KNOTS ARE EXPECTED TO DEVELOP LATER THIS MORNING. EXPECT TO SEE SOME LOWER 20 KNOT WIND GUSTS ON THE SOUTH COAST THIS AFTERNOON...BUT THINK SPEEDS WILL GENERALLY BE JUST BELOW SCA THRESHOLDS SO HELD OFF ON ANY HEADLINES. SEAS WILL BE CHOPPY THOUGH IN SOME OF THE SOUNDS AND BAYS. TONIGHT...THE PRESSURE GRADIENT SHOULD REMAIN WEAK ENOUGH TO KEEP WINDS AND SEAS BELOW SCA THRESHOLDS. SATURDAY...INTENSIFYING LOW PRESSURE WILL LIKELY TRACK JUST SOUTHEAST OF THE BENCHMARK LATE IN THE AFTERNOON AND EARLY IN THE EVENING. WINDS AND SEAS SHOULD REMAIN BELOW SCA THRESHOLDS DURING THE MORNING. HOWEVER...EXPECT SCA NORTHEAST WIND GUSTS AND SEAS TO DEVELOP DURING THE AFTERNOON AS THE PRESSURE GRADIENT INCREASES. IN FACT...WINDS SHOULD TURN MORE NORTHERLY AND INCREASE FURTHER TO NEAR GALE FORCE WIND GUSTS TOWARD 00Z. A GALE WATCH HAS BEEN ISSUED FOR THE OPEN WATERS FROM 22Z SATURDAY INTO SATURDAY NIGHT. IN ADDITION...SNOW IN THE NORTHERN WATERS WITH MAINLY RAIN IN THE SOUTHERN WATERS WILL REDUCE VISIBILITIES FOR MARINERS. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT...HAVE ISSUED GALE WATCHES FOR THIS PERIOD AS WINDS SHIFT TO NW AND PICK UP. GUSTS TO 35-40 KT LIKELY. LEFTOVER LOWERED VSBYS IN SNOW/SNOW SHOWERS...SHOULD IMPROVE FROM W-E WITH LINGERING PRECIP ACROSS THE EASTERN WATERS. LIGHT FREEZING SPRAY WILL DEVELOP AS WELL. SUNDAY-SUNDAY NIGHT...WINDS BRIEFLY DIMINISH SUNDAY...THEN PICK UP TO GALE FORCE AGAIN BY SUNDAY NIGHT AS THE ARCTIC AIR WORKS IN. FREEZING SPRAY CONTINUES...BECOMING MODERATE SUNDAY NIGHT. FREEZING SPRAY ADVISORY WILL LIKELY BE NEEDED BY SUN NIGHT. MONDAY...W-NW GALE FORCE GUSTS WILL CONTINUE INTO MONDAY MAINLY OVER THE OUTER WATERS S AND E OF NANTUCKET...BUT SHOULD DIMINISH TO SMALL CRAFT BY MIDDAY. WINDS AND SEAS SHOULD DIMINISH BELOW SMALL CRAFT MON NIGHT. TUESDAY...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...GALE WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY MORNING FOR ANZ231>235-237-250-251-254>256. && $$ SYNOPSIS...FRANK/EVT NEAR TERM...FRANK/RLG/EVT SHORT TERM...FRANK LONG TERM...EVT AVIATION...RLG/EVT MARINE...FRANK/EVT EOF