Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBOX 291420 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1020 AM EDT WED OCT 29 2014 .SYNOPSIS... A COLD FRONT WILL PUSH ACROSS THE REGION TODAY...BRINGING SCATTERED SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO. THE FRONT WILL PUSH OFFSHORE THIS EVENING. WEAK HIGH PRESSURE WILL MOVE ACROSS THURSDAY AND FRIDAY WHICH WILL BRING DRY...SEASONABLE CONDITIONS. A DEVELOPING COASTAL STORM OFF THE CAROLINAS WILL PASS OFFSHORE SATURDAY NIGHT. HIGH PRESSURE BUILDS OVER THE EASTERN USA EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
COLD FRONT PRESENTLY STRETCHED ALONG THE SPINE OF THE APPALACHIA. WARM-FRONT STALLED OVER THE HIGHER TERRAIN OF THE WHITE MOUNTAINS TO THE N. FOG HAS SLOWLY LIFTED OVER N MA AND S NH AND EXPECT A GRADUAL IMPROVEMENT OVER THE NEXT HOUR OR TWO...THUS HAVE DROPPED THE DENSE FOG ADVISORY. OTHERWISE...SW-FLOW OF GULF-MOISTURE ALONG AND AHEAD ADVECTING PWATS UP TO 1.25-INCHES. UNDERGOING AT LEAST SOME LEVEL OF DEEP- LAYER ASCENT AND LIFT BENEATH THE RRQ OF THE UPPER-LEVEL JET... ASIDE FROM BETTER DYNAMICS WELL N...A LINE OF SHOWERS CONTINUES ALONG AND TO THE REAR OF THE COLD FRONT WITH EMBEDDED HEAVIER DOWNPOURS. FEEL THE BETTER INSTABILITY WILL REMAIN SE AND OFFSHORE. THOUGH LAPSE RATES WILL BE PRETTY STEEP WHEREVER IT WARMS ABOVE THE CONVECTIVE TEMPERATURE /ABOVE 70-DEGREES/. THUS WILL HOLD WITH THE CHANCE OF THUNDERSTORMS OVER SE MA AND RI... ALBEIT BRIEF AS THE WINDOW OF OPPORTUNITY WITH STEEP ENVIRONMENTAL PROFILE PUSHES NE INTO THE GULF OF MAINE. EXPECT THAT AS THIS LINE PUSHES S AND E...SHOWERS ARE ANTICIPATED TO BECOME SLIGHTLY MORE DIFFUSE AS A RESULT OF STRETCHED MID-LEVEL ENERGY AND LESSENING INSTABILITY. MILD THIS MORNING WITH THE POTENTIAL OF SOME CLOUD BREAKS. MAIN FOCUS OF WARMER CONDITIONS IS ACROSS SE NEW ENGLAND WHERE HIGHS INTO THE LOW-70S ARE POSSIBLE. COULD GET WARMER. NOT OUT OF THE REALM OF POSSIBILITIES. BLUSTERY SW-FLOW AHEAD OF THE FRONT...ESPECIALLY OVER S/SE-COASTAL NEW ENGLAND WITH GUSTS UP TO 25 MPH.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... TONIGHT... THE H5 LONG WAVE TROUGH PUSHES E...AND APPROACHING WESTERN AREAS BY EARLY THURSDAY. SCT SHOWERS MAY LINGER THROUGH MIDNIGHT OR SO ACROSS E MA/RI/NE CT...BUT SHOULD IMPROVE AFTER THAT. H85 TEMPS WILL STEADILY DROP OVERNIGHT...BUT SOME CLOUDS WILL LINGER. BY SUNRISE...H85 TEMPS FALL TO -2C ACROSS WESTERN AREAS TO +2C ACROSS THE CAPE. WHILE NW WINDS WILL BE LIGHT...EXPECT THEM TO STIR ENOUGH NOT TOO ALLOW RADIATIONAL COOLING WHERE SKIES BECOME PARTLY CLOUDY WELL INLAND. LOWS WILL RANGE FROM THE UPPER 30S ACROSS THE E SLOPES OF THE BERKSHIRES TO BETWEEN 45 AND 50 ALONG THE IMMEDIATE COAST. THURSDAY... SURFACE HIGH RIDGE BUILDS NE INTO WESTERN NEW ENGLAND DURING THE DAY WHILE THE H5 TROUGH MOVES OFFSHORE DURING THURSDAY. MUCH COOLER CONDITIONS WILL BE IN PLACE AS COLD AIR ADVECTION CONTINUES TO SHIFT ACROSS THE REGION. TEMPS WILL ONLY TOP OFF IN THE 50S...CLOSE TO SEASONAL NORMALS BUT A GOOD 15 DEGREES OR SO LOWER THAN TODAY. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... BIG PICTURE... 29/00Z GUIDANCE SUITE CONTINUES TO COME INTO BETTER AGREEMENT. THERE IS STILL PLENTY OF ROOM FOR IMPROVEMENT REGARDING THE DETAILS. THE WEATHER THIS WEEK WILL BE DRIVEN BY A HIGHLY AMPLIFIED...ANOMALOUS PATTERN. THE CORE OF AN OFFSHORE LOW PRESSURE WAS ABOUT 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL. THE CORE OF THE 500 MB LOW WAS NEARLY 5 STANDARD DEVIATIONS BELOW NORMAL. THIS MEANS WE NEED TO KEEP THE GUIDANCE DETAILS IN PERSPECTIVE... AS MODELS TYPICALLY DO NOT HANDLE EXTREME EVENTS PERFECTLY. IT IS ENCOURAGING TO SEE THE GUIDANCE CONVERGING ON A SOLUTION THOUGH. WILL CONTINUE TO FAVOR A CONSENSUS MEAN SOLUTION TO SMOOTH OVER SOME OF THE MINOR DIFFERENCES. WE EXPECT BETTER AGREEMENT OVER THE NEXT FEW DAYS NOW THAT THE ENERGY WHICH WILL PRODUCE THIS COASTAL STORM WILL BE OVER LAND AND BETTER SAMPLED. THE 29/00 ECMWF STILL REMAINS SLIGHTLY FARTHER WEST AND QUICKER WITH IT SURFACE LOW PRESSURE. THAT SAID...ITS TRACK IS STILL EAST OF 70W LONGITUDE AS IT PASSES BY OUR REGION. THIS SHOULD MEAN THE GREATEST EFFECTS SHOULD BE FELT TOWARD THE COASTS. THE DAILIES... THURSDAY NIGHT INTO FRIDAY...COOLING ALOFT WITH WEAK RIDGING NEAR THE SURFACE. THIS SHOULD KEEP THE WEATHER DRY INTO AT LEAST THE FIRST PART OF FRIDAY. AS A SHORTWAVE DIVES INTO THE GREAT LAKES TROUGH AND TURNS THE UPPER FLOW OVER US MORE SOUTH-SOUTHWEST. MEANWHILE WEAK RIDGING BUILDS TO OUR NORTH AND TURNS OUR WIND EAST OR NORTHEAST. SATURDAY INTO SUNDAY...THIS WILL BE THE MAIN PERIOD OF RISK FOR PRECIPITATION DURING THIS PORTION OF THE FORECAST. STRONG MID LEVEL TROUGH MOVES EAST FROM THE GREAT LAKES TO THE ATLANTIC COAST. UPPER JET FROM CENTRAL CANADA FEEDS AROUND THIS UPPER TROUGH WITH THE LEFT EXIT REGION MOVING OVER THE CAROLINAS FRIDAY NIGHT/EARLY SATURDAY. THIS SUPPORTS THE IDEA OF A COASTAL LOW DEVELOPING. STILL SOME QUESTIONS WITH THE TRACK...WHICH WILL BE A KEY INGREDIENT TO DETERMINING PRECIPITATION TYPE. CONFIDENT THAT THERE WILL BE UNSETTLED WEATHER THIS WEEKEND...WITH GREATEST RISK ALONG THE COASTAL PLAIN AND DIMINISHING POPS FARTHER NORTHWEST. WILL REFLECT THIS WITH LIKELY POPS SOUTHEAST GRADING TO CHANCE POPS NORTHWEST. LOWER CONFIDENCE ON PRECIPITATION TYPE. MUCH OF THIS TIME SHOULD BE RAIN. WITH TEMPERATURES FORECAST TO FALL TO FREEZING OR BELOW SATURDAY NIGHT...THE RESULT WILL BE SOME SNOW...ESPECIALLY ACROSS THE HIGHER TERRAIN OF SOUTHERN NEW ENGLAND. MONDAY INTO TUESDAY...HIGH PRESSURE BUILDS OVER THE REGION. LINGERING CLOUDS BENEATH THE COLD POOL ALOFT...ESPECIALLY ON MONDAY. OTHERWISE FAIR AND DRY WITH TEMPERATURES CLOSER TO NORMAL BY TUESDAY. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...THROUGH THURSDAY...MODERATE CONFIDENCE. THROUGH 12Z...MAINLY VFR. PATCHY MVFR-IFR CIGS/VSBYS WITH LOCAL PERIODS OF LIFR IN DENSE FOG...GENERALLY ACROSS NE MA/S CENTRAL NH. S-SW WINDS GUSTING TO AROUND 20 KT ALONG S COAST...CAPE COD AND THE ISLANDS. MAY SEE SCT SHOWERS APPROACH SW NH/NW MA AFTER 09Z. TODAY...MAINLY VFR. PATCHY MVFR CIGS/VSBYS IN SHOWERS. LOW PROB FOR ISOLD TSTM OR TWO FROM LATE MORNING THROUGH THE DAY NEAR OR AHEAD OF FRONT. S-SW WINDS GUSTING TO 20-25 KT MAINLY ALONG S COAST...CAPE COD AND THE ISLANDS. CONDITIONS IMPROVE ACROSS SW NH/W MA AFTER 18Z AS COLD FRONT SHIFTS E. TONIGHT...MAINLY VFR. MVFR CIGS/VSBYS ACROSS CENTRAL AND EASTERN AREAS THROUGH 03Z-05Z...THEN IMPROVING AS COLD FRONT PUSHES OFF COAST. SW WINDS GUSTING TO 20-25 KT EARLY TONIGHT ACROSS CAPE COD AND THE ISLANDS...THEN SHIFT TO W AND DIMINISH AFTER MIDNIGHT. LEFTOVER SCT SHOWERS MAY LINGER ACROSS CAPE AND ISLANDS THROUGH THE NIGHT. THURSDAY...VFR. PATCHY DIURNAL CLOUDS AT 4-5KFT ACROSS INTERIOR FROM LATE MORNING THROUGH THE AFTERNOON. KBOS...HIGH CONFIDENCE IN TAF. KBDL...HIGH CONFIDENCE IN TAF. LOW CONFIDENCE ON MVFR-IFR CONDITIONS IN LOW CLOUDS. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... THURSDAY NIGHT INTO FRIDAY...HIGH CONFIDENCE. VFR. FRIDAY NIGHT THROUGH SUNDAY...LOW CONFIDENCE IN TIMING AND PRECIPITATION TYPE. MODERATE CONFIDENCE IN PRECIPITATION OCCURRENCE. CIGS/VSBYS LOWERING TO IFR COASTAL PLAIN AND MVFR NORTHWEST. COASTAL STORM PASSES BY LATER SATURDAY/SATURDAY NIGHT WITH A MIX OF RAIN AND SNOW ESPECIALLY KMHT-KORH-KBAF-KBDL. PRECIPITATION TAPERS OFF SUNDAY. NORTH-NORTHEAST WINDS WITH GUSTS ALONG THE COAST 25-35 KNOTS SATURDAY. NORTHWEST WINDS SUNDAY WITH GUSTS 25 TO 30 KNOTS INLAND AND 30 TO 40 KNOTS ALONG THE COAST. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE. TODAY AND TONIGHT...SMALL CRAFT ADVISORIES CONTINUE ON THE EASTERN OUTER WATERS AS WELL AS THE SOUTHERN OPEN WATERS AS LOW LEVEL SW JET MOVES ACROSS TODAY. EXPECT GUSTS UP TO AROUND 25 KT. SEAS WILL BUILD TO AROUND 6 FT ON THE SOUTHERN OUTER WATERS THROUGH THIS EVENING. AS THE FRONT PASSES A FEW SHOWERS ARE POSSIBLE WHICH MAY REDUCE VSBYS. AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT. WINDS SHIFT TO W AND TEND TO DIMINISH TONIGHT...BUT WILL STILL SEE SOME GUSTS UP TO 25 KT EARLY ON THE SOUTHERN WATERS. SEAS WILL LINGER AOA 5 FT ON THE OUTER WATERS...BUT SHOULD SLOWLY SUBSIDE. THURSDAY...LIGHT NW WINDS IN PLACE. LEFTOVER 5 FT SEAS ON THE OUTER WATERS EARLY SHOULD SUBSIDE. OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...MODERATE CONFIDENCE. THURSDAY NIGHT AND FRIDAY...WEAK HIGH PRESSURE BUILDS NORTH OF THE WATERS. NORTHWEST WINDS THURSDAY BECOME NORTHEAST FRIDAY BUT REMAIN BELOW 20 KNOTS. SEAS GENERALLY LESS THAN 5 FEET. FRIDAY NIGHT THROUGH SUNDAY...COASTAL LOW PRESSURE DEVELOPS OFF THE CAROLINAS AND MOVES UP THE COAST. MODERATE UNCERTAINTY IN THE EXACT TRACK AND TIMING...WITH THE GENERAL CONSENSUS SOLUTION STAYING SOUTH AND EAST OF THE 40N/70W BENCHMARK. AT LEAST MODERATE CONFIDENCE IN STRONG NORTH TO NORTHEAST WINDS WITH FREQUENT GUSTS SATURDAY 25 TO 35 KNOTS SHIFTING TO NORTHWEST 30 TO 40 KNOTS SUNDAY. A GALE WATCH/GALE WARNING MAY EVENTUALLY BE NEEDED FOR PORTIONS OF THIS WEEKEND. && .BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ231>234-250. SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ235- 237. SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ254>256.
-- End Changed Discussion --
&& $$ SYNOPSIS...BELK/EVT NEAR TERM...BELK/SIPPRELL/EVT SHORT TERM...EVT LONG TERM...BELK AVIATION...BELK/EVT MARINE...BELK/EVT

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.