Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 100010 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 710 PM EST TUE FEB 9 2016 .SYNOPSIS... MAINLY DRY CHILLY WEATHER IS IN STORE FOR SOUTHERN NEW ENGLAND TONIGHT. FAST MOVING LOW PRESSURE MAY BRING SCATTERED LOCALLY HEAVY SNOW SHOWERS TO THE REGION WEDNESDAY WITH THE HIGHEST RISK ACROSS NORTHERN CONNECTICUT AND NEAR THE SOUTH COAST. SOME SCATTERED SNOW SHOWERS ARE LIKELY THURSDAY AND FRIDAY. BITTERLY COLD WEATHER IS EXPECTED THIS WEEKEND. THERE IS POTENTIAL FOR MORE PRECIP EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 645 PM UPDATE.. STILL NOTING SOME PARTLY CLOUDY SKIES ACROSS N CENTRAL AND NE MA...BUT LOW AND MID LEVEL CLOUDS ARE MOVING QUICKLY NE OVER THE LAST COUPLE OF HOURS AS SEEN ON IR SATELLITE IMAGERY. ALSO NOTING A FEW SNOW SHOWERS REACHING FROM THE MID HUDSON VALLEY INTO PORTIONS OF THE BERKSHIRES AT 23Z. NOT SEEING TOO MUCH EASTWARD PROGRESS ON NE REGIONAL 88D RADAR...MAINLY DUE TO DRY AIRMASS ACROSS SOUTHERN NEW ENGLAND. DEWPT DEPRESSIONS ON ORDER OF 7 TO 10 DEGREES IN PORTIONS OF THE CT VALLEY. NEAR TERM FORECAST LOOKS PRETTY MUCH ON TRACK. HAVE UPDATED TO BRING CONDITIONS CURRENT. ***SEE TIDES/COASTAL FLOODING SECTION BELOW FOR 7 PM UPDATES*** PREVIOUS DISCUSSION... OVERNIGHT CLOUDS WILL BE ON THE INCREASE AS SHORT WAVE ENERGY OVER THE GREAT LAKES AND OH VLY APPROACHES THE REGION. THERE IS LOW RISK FOR SNOW SHOWERS TO BREAK OUT ACROSS WESTERN CT AND MA TOWARD DAYBREAK. OTHERWISE FAIRLY TRANQUIL WITH LIGHT WINDS AND SEASONABLY COOL TEMPS WITH MINS MAINLY IN THE UPPER TEENS AND LOW 20S. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... *** SCATTERED BUT LOCALLY HEAVY SNOW SHOWERS POSSIBLE WITH THE HIGHEST RISK ACROSS WESTERN MA/CT AND THE SOUTH COAST *** WEDNESDAY ... IMPRESSIVE SHORT WAVE TROUGH MOVES OVER OR JUST OF THE AREA TOMORROW. THIS FEATURE SHOWS UP NICELY AS A PV ANOMALY ON THE TROPOPAUSE. MODEST SYNOPTIC SCALE LIFT WITH THIS FEATURE ALONG WITH DEEP LAYER MOISTURE. THUS THE ENTIRE REGION WILL SEE SCATTERED SNOW SHOWERS. THE DIFFICULT PART OF THE FORECAST IS THE INTENSITY AND AREAL COVERAGE OF THIS ACTIVITY AS MESOSCALE ATTRIBUTES COME INTO PLAY. GOOD MODEL AGREEMENT THAT THE ATMOSPHERE WILL BECOME QUITE UNSTABLE WITH BOTH LOW AND MID LEVEL LAPSE RATES GREATER THAN MOIST ADIABATIC /6.5C-KM/ AND POSSIBLY APPROACHING 8C/KM ALONG WITH TT NEARING 60! FURTHERMORE THERE APPEARS TO BE SUFFICIENT MOISTURE IN THE COLUMN FOR THIS INSTABILITY TO BE REALIZED...POTENTIALLY OFFERING A STRONG RESPONSE IN THE FORM OF SCATTERED HEAVY SNOW SHOWERS. UNFORTUNATELY MODEL GUID IS NOT IN GOOD AGREEMENT ON SIMULATING THESE HEAVIER SNOW SHOWERS. THE 12Z GFS IS MOST ROBUST BUT MAY BE SUFFERING FROM SOME CONVECTIVE FEEDBACK. HOWEVER THE MODEL CONSENSUS IS THAT THE MOST INTENSE SNOW SHOWERS MAY DEVELOP ACROSS LONG ISLAND NY AND THEN MOVE ENE OVER BID-MVY AND POSSIBLY ONTO THE SOUTH COAST OF MA AND RI. THUS GREATEST RISK IS ACROSS THIS REGION ALONG WITH A POSSIBLE BURST IN THE MORNING OVER WESTERN CT-MA. WHILE POTENTIAL SNOW TOTALS ARE NOT THAT IMPRESSIVE THE IMPACT WOULD RESULT FROM A QUICK 1-2" IN A SHORT PERIOD OF TIME. IF THE GFS SIMULATION IS CORRECT LOCALIZED AMOUNTS OF UP TO 3-4" ARE POSSIBLE. TIMELINE...SNOW SHOWERS APPROACH WESTERN CT-MA INCLUDING HARTFORD/SPRINGFIELD AROUND 12Z...THUS POTENTIALLY IMPACTING THE MORNING COMMUTE. SNOW SHOWERS OVERSPREAD THE REMAINDER OF THE REGION 15Z-18Z AND POSSIBLY LINGERING ACROSS RI/EASTERN MA INCLUDING BOSTON- PROVIDENCE CORRIDOR TIL 21Z. HENCE POSSIBLY IMPACTING THE LATE DAY COMMUTE HERE. WILL ISSUE A SPECIAL WEATHER STATEMENT TO HEIGHTEN PUBLIC AWARENESS ON POTENTIAL IMPACTS AND ALSO ADDRESS THE UNCERTAINTY. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... HIGHLIGHTS... * SNOW SHOWERS POSSIBLE THROUGH SAT * MUCH COLDER AIR MOVES INTO SOUTHERN NEW ENGLAND FOR THE WEEKEND * MORE PRECIPITATION POSSIBLE EARLY NEXT WEEK A COMPLEX FORECAST FOR THE LONG TERM. THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE SYNOPTIC SCALE PATTERN WITH CONTINUED TROUGHING OVER THE EAST COAST AND RIDGING OVER THE WESTERN CONUS. DIFFERENCES AND CHALLENGES COME IN THE EXACT PATH OF THE SYNOPTIC FEATURES... INCLUDING SHORTWAVES...AS WELL AS THE MORE MESOSCALE FEATURES. WEDNESDAY NIGHT...HIGH CONFIDENCE. A WEAK SHORTWAVE WILL EXIT SOUTHERN NEW ENGLAND...PUSHING LOW PRESSURE OUT OF NORTHERN NEW ENGLAND AND INTO THE GULF OF MAINE. THIS WILL PULL A WEAK COLD FRONT THROUGH THE REGION. EXPECT THE OVERNIGHT PERIOD TO BE MOSTLY DRY WITH THE MAIN IMPACT FROM THE FRONT BEING SOME CLOUDS AND COLDER TEMPERATURES MOVING IN FOR THURSDAY. THURSDAY...MODERATE CONFIDENCE. A STRONGER SHORTWAVE TROUGH MOVES THROUGH SOUTHERN NEW ENGLAND THURSDAY. BELOW NORMAL TEMPERATURES ARE EXPECTED BEHIND THE COLD FRONT THAT MOVED THROUGH WEDNESDAY NIGHT. HOWEVER...THERE IS ENOUGH LIFT AND MOISTURE ASSOCIATED WITH THE SHORTWAVE THAT WE COULD SEE SOME SCATTERED SNOW SHOWERS ACROSS THE REGION. NOT MUCH EXPECTED AT THIS TIME...PERHAPS AS MUCH AS AN INCH OR TWO IN A FEW SPOTS. FRIDAY...HIGH CONFIDENCE. AS AN UPPER LEVEL TROUGH MOVES INTO THE NORTHEASTERN U.S...LOW PRESSURE IN THE GREAT LAKES MOVES THROUGH NORTHERN NEW ENGLAND BRINGING AN ARCTIC FRONT THROUGH SOUTHERN NEW ENGLAND. AGAIN...THIS WILL BRING A CHANCE OF SNOW SHOWERS AHEAD OF THE FRONT. JUST LIGHT AMOUNTS EXPECTED AT THIS TIME...A DUSTING TO MAYBE AN INCH OR TWO. THE BIG STORY WITH THIS FRONT WILL BE THE STRONG PUSH OF ARCTIC AIR MOVING INTO THE REGION. TEMPERATURES FRIDAY WILL ALREADY BE MORE THAN 10 DEGREES BELOW NORMAL FOR MID FEBRUARY AND THE COLDER AIR IS YET TO COME. THIS WEEKEND...HIGH CONFIDENCE. NOT MUCH...IF ANY...PRECIPITATION IS EXPECTED. INSTEAD THE COLD WILL TAKE CENTER STAGE...ALONG WITH SOME BITTERLY COLD WIND CHILLS. ARCTIC AIR CONTINUES TO SEEP INTO SOUTHERN NEW ENGLAND WITH HIGHS EXPECTED TO BE 20 TO EVEN 25 DEGREES BELOW NORMAL. WHILE THIS IS STILL SEVERAL DAYS OUT AND THERE IS SOME UNCERTAINTY TO BE HAD...09/12Z EPS PROBABILITIES HAVE AN OVER 90 PERCENT CHANCE OF LOW TEMPERATURES DROPPING BELOW ZERO AND OVER 80 PERCENT CHANCE OF LOW TEMPERATURES BELOW NEGATIVE 10 DEGREES! THUS...HAVE HIGH CONFIDENCE IN BITTER COLD TEMPERATURES THROUGH THE WEEKEND. IN ADDITION...ON SATURDAY...STRONG LOW PRESSURE IN THE MARITIMES COUPLED WITH AN EQUALLY STRONG HIGH PRESSURE IN THE GREAT LAKES/OHIO VALLEY REGION WILL RESULT IN A VERY TIGHT PRESSURE GRADIENT ACROSS SOUTHERN NEW ENGLAND. THIS WILL RESULT IN NORTHWESTERLY WINDS AROUND 20 MPH...GUSTING TO AROUND 30 MPH...EVEN THROUGHOUT MUCH OF SATURDAY NIGHT. WITH TEMPERATURES AS COLD AS THEY ARE CURRENTLY FORECAST TO BE...EVEN JUST SLIGHTLY BREEZY CONDITIONS WILL RESULT IN VERY COLD WIND CHILLS. AT THIS TIME...WE ARE LOOKING AT WIND CHILLS BETWEEN 20 AND 30 DEGREES BELOW ZERO SATURDAY NIGHT. DURING THE DAY SATURDAY...WIND CHILLS IN THE SINGLE DIGITS BELOW ZERO AND 5 TO 15 DEGREES BELOW ZERO FOR SUNDAY. IT WILL DEFINITELY BE A WEEKEND TO BUNDLE UP AND STAY INDOORS. MONDAY AND TUESDAY...LOW CONFIDENCE. THERE ARE SOME INDICATIONS THAT THERE MAY BE A STORM BRINGING SOME PRECIPITATION TO SOUTHERN NEW ENGLAND EARLY NEXT WEEK. HOWEVER...WHETHER IT IS RAIN OR SNOW IS UNCERTAIN...AS WELL AS THE TRACK OF THE POTENTIAL STORM. STAY TUNED TO FUTURE FORECASTS FOR MORE INFORMATION. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. TONIGHT ... HIGH CONFIDENCE. MAINLY VFR ACROSS N CENTRAL AND NW MA...OTHERWISE LOW END VFR TO MVFR CIGS AND VFR VSBYS. REMAINING DRY THROUGH 06Z...THEN CHANCE FOR SNOW SHOWERS TOWARD DAYBREAK MOVING IN FROM WEST TO EAST. LIGHT/VRBL OR CALM WINDS. WEDNESDAY ... LOW TO MODERATE FORECAST CONFIDENCE. MVFR-VFR LOWERING TO MVFR-IFR FROM WEST TO EAST IN SCATTERED SNOW SHOWERS. SNOW SHOWERS WILL BE MOST NUMEROUS ALONG THE SOUTH COAST OF MA AND RI WITH A FEW HEAVY SNOW SHOWERS LIKELY. UNCERTAINTY IS HOW FAR NORTH DOES HEAVIER ACTIVITY TRACK. CURRENT INDICATES IS BID-MVY-ACK AND ALONG THE SOUTH COAST OF RI INTO MA. SNOWFALL OF 1-3" IS POSSIBLE IN THIS AREA WITH AN 1" OR LESS ELSEWHERE. THIS CAN CHANGE SO MONITOR LATER FORECASTS. KBOS TERMINAL...MAIN CONCERN IS SCATTERED SNOW SHOWERS WED WITH A FEW LOCALLY HEAVIER SNOW SHOWERS...LIKELY SOUTH OF THE AIRPORT TOWARD THE SOUTH COAST OF MA. KBDL TERMINAL...MAIN CONCERN IS SCATTERED SNOW SHOWERS WED AM WITH A FEW LOCALLY HEAVIER SNOW SHOWERS. EXACT LOCATION DIFFICULT TO PINPOINT. HOWEVER TIME WINDOW IS 10Z-16Z. OUTLOOK /WEDNESDAY NIGHT THROUGH SUNDAY/... WEDNESDAY NIGHT...HIGH CONFIDENCE. MAINLY VFR CONDITIONS. THURSDAY THROUGH FRIDAY...MODERATE CONFIDENCE. MAINLY VFR CONDITIONS. ARCTIC FRONT MOVES THROUGH THE REGION FRIDAY WITH GUSTY NW WINDS. CHANCE OF -SHSN. EXPECTED ACCUMULATION LESS THAN TWO INCHES. SATURDAY AND SUNDAY...MODERATE CONFIDENCE. MAINLY VFR CONDITIONS. NW WINDS GUSTING TO 25-30 KTS LIKELY. BITTERLY COLD TEMPERATURES EXPECTED. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY/...HIGH CONFIDENCE. TONIGHT ... LIGHT WINDS BUT LARGE EASTERLY SWELLS CONTINUE ON THE OCEAN WATERS OF MA AND RI. OTHER THAN AN ISOLATED SNOW SHOWER MAINLY DRY AND GOOD VSBY. WED ... LOW PRES FORMS OVER SOUTHERN NEW ENGLAND TOMORROW. SCATTERED SNOW SHOWERS WILL ACCOMPANY THIS BROAD AREA OF LOW PRES. VSBY MAY LOWER BELOW 1 MILE IN A FEW OF THE HEAVIER SNOW SHOWERS. OUTLOOK /WEDNESDAY NIGHT THROUGH SUNDAY/... WEDNESDAY NIGHT...HIGH CONFIDENCE. SOUTHWESTERLY WINDS SHIFT AROUND TO THE WEST AS A WEAK COLD FRONT MOVES OVER THE WATERS. WINDS AND SEAS DIMINISH SLOWLY BUT WILL REMAIN OVER FIVE FEET. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED. THURSDAY...HIGH CONFIDENCE. WINDS SHIFT TO THE NORTHWEST AND INCREASE AS THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE IN THE MID- ATLANTIC AND LOW PRESSURE IN THE MARITIMES INCREASES. SEAS ALSO INCREASE. SMALL CRAFT ADVISORIES DEFINITE...LOW PROBABILITY OF GALE WARNINGS BEING NECESSARY. FRIDAY...MODERATE CONFIDENCE. WINDS AND SEAS SUBSIDE AS HIGH PRESSURE TRIES TO BUILD IN AHEAD OF AN ARCTIC FRONT THAT MOVES THROUGH FRIDAY NIGHT. SMALL CRAFT ADVISORIES LIKELY. SATURDAY...MODERATE CONFIDENCE. NORTHWESTERLY WINDS CONTINUE BETWEEN LOW PRESSURE IN THE MARITIMES AND HIGH PRESSURE IN THE GREAT LAKES. SMALL CRAFT ADVISORIES DEFINITE...WITH A LOW PROBABILITY OF GALE FORCE WINDS. SUNDAY...MODERATE CONFIDENCE. WINDS AND SEAS DIMINISH AS HIGH PRESSURE BUILDS OVER THE WATERS. SMALL CRAFT ADVISORIES MAY STILL BE POSSIBLE. && .TIDES/COASTAL FLOODING... 7 PM UPDATE...STILL SEEING SURGE VALUES BETWEEN 1.5 AND 2 FEET ON THE RI SOUTH COAST...1 TO 1.5 FEET ON THE MA EAST COAST...AND 3 FEET AT CHATHAM. ALONG MUCH OF THE MA EAST COAST THIS SHOULD NOT CAUSE ANY PROBLEMS TONIGHT AS THIS HIGH TIDE IS THE LOWER OF THE TWO HIGH TIDES FOR THE DAY. ON THE SOUTH COAST OF RI THIS SUSTAINED SURGE WILL LIKELY RESULT IN SOME SPLASHOVER AND POSSIBLY EVEN SOME MINOR COASTAL FLOODING...PARTICULARLY WITHIN NARRAGANSETT BAY. THIS WOULD INCLUDE PROVIDENCE...NEWPORT...AND FALL RIVER. THIS HIGH TIDE OCCURS AROUND 830 PM THIS EVENING. FINALLY...TONIGHTS HIGH TIDE AT CHATHAM IS THE HIGHER OF THE TWO HIGH TIDES FOR TODAY. THIS PLUS THE 3 FOOT SURGE WILL LIKELY RESULT IN SOME SPLASHOVER AND MINOR COASTAL FLOODING IN CHATHAM... AND POSSIBLY ALONG OTHER PARTS OF THE EAST COAST OF CAPE COD. HIGH TIDE HERE WILL OCCUR AROUND 1 AM. THEREFORE...HAVE ISSUED A COASTAL FLOOD STATEMENT FOR THE RI SOUTH COAST AND FOR CAPE COD FOR TONIGHT. AGAIN...THE MAIN CONCERNS ARE WITHIN NARRAGANSETT BAY AROUND 830PM TONIGHT AND AROUND CHATHAM AT 1AM. ASTRO TIDES REMAIN HIGH TOMORROW WITH MIDDAY HIGH TIDE AT BOSTON ALMOST 12 FT. HOWEVER WITH LACK OF SURGE AND SEAS CONTINUING TO ERODE DON/T THINK ANY COASTAL FLOODING WILL MATERIALIZE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR ANZ235-237- 250-254>256. SMALL CRAFT ADVISORY UNTIL 7 AM EST WEDNESDAY FOR ANZ251. && $$ SYNOPSIS...NOCERA/RLG NEAR TERM...NOCERA/RLG/EVT SHORT TERM...NOCERA LONG TERM...RLG AVIATION...NOCERA/RLG/EVT MARINE...NOCERA/RLG TIDES/COASTAL FLOODING...NOCERA/RLG

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