Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 291842 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 242 PM EDT WED OCT 29 2014 .SYNOPSIS...
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SHOWERS CONCLUDE BEHIND A COLD FRONT PUSHING OFFSHORE TONIGHT. SEASONABLE AND DRIER WEATHER FOLLOWS INTO THE END OF THE WEEK UNDER HIGH PRESSURE. A DEVELOPING COASTAL STORM OFF THE CAROLINAS WILL PASS OFFSHORE SATURDAY NIGHT. HIGH PRESSURE BUILDS OVER THE EASTERN USA EARLY NEXT WEEK.
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&& .NEAR TERM /THROUGH TONIGHT/...
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230 PM UPDATE... COLD FRONT PUSHING ACROSS S NEW ENGLAND WITH SHOWERY WEATHER AND THICKER CLOUDS IN TOW. CONDITIONS CONTINUE TO WARM BENEATH THE THIN VEIL OF MID- TO HIGH-LEVEL CLOUDS. SW-FLOW CONTINUES TO GUST IN EXCESS OF 25 MPH ALONG THE S/SE SHORELINE. MAIN CONCERN FOR THE REMAINDER OF THE FORECAST PERIOD INTO THIS EVENING IS THE TIMING OF SHOWERS AHEAD OF THE MAIN DRIVING FORCE THAT BEING THE STRETCHED MID-LEVEL TROUGH AXIS. WITH CONDITIONS WARMING ACROSS SE NEW ENGLAND BENEATH A CONDITIONALLY UNSTABLE ENVIRONMENT...ECHO OVERNIGHT FORECASTERS THOUGHTS CONCERNING THE POSSIBILITY OF AN ISOLATED THUNDERSTORM OR TWO ACROSS SE NEW ENGLAND. NOTHING SEVERE. ASIDE...EXPECT A BAND OF SHOWERS WITH EMBEDDED HEAVIER DOWNPOURS TO MARCH ACROSS THE REGION INTO THIS EVENING BENEATH FAVORABLE DEEP-LAYER ASCENT. FEEL THE HIGH-RES WRF GUIDANCE AND HRRR HAVE A GOOD HANDLE ON THE PRESENT SITUATION...ALBEIT SLIGHT DIFFERENCES. COULD SEE THE LINE OF SHOWERS BECOME DIFFUSE WITH ITS TRACK TO THE S AND E. SPECULATE THIS TO BE CONSEQUENTIAL OF STRETCHED MID-LEVEL ENERGY AND PERHAPS THE COLD FRONT BECOMING TOO SEPARATED FROM ITS PARENT MID-LEVEL TROUGH. ALSO PERHAPS AS THE COLD FRONT PUSHES OFFSHORE TOWARDS A BETTER MOIST-INSTABILITY AXIS ACTIVITY ERUPTS THAT USURPS ACTIVITY TO THE W. ALL SORTS OF FACTORS...BUT ASIDE NOT A BIG DEAL BUT JUST A SWEEPING WET-WEATHER MAKER. ALREADY 72-DEGREES HERE AT THE TAUNTON WFO. EXPECT CONDITIONS TO CONTINUE WARMING INTO THE MID-70S FOR S/SE NEW ENGLAND. A BLEND OF THE RAP APPEARS GOOD ENOUGH WITH REGARDS TO 2M TEMPERATURES THOUGH NOT HANDLING THE WARM-FRONT ALL THAT WELL. TONIGHT... MAIN TROUGH AXIS PUSHING THROUGH THE REGION OVERNIGHT. COLD FRONT PUSHES OFFSHORE AS CLOUDS AND SHOWERS LINGER REARWARD ACROSS S- AND E-PORTIONS OF NEW ENGLAND TOWARDS THURSDAY MORNING. SURFACE HIGH PRESSURE BUILDS INTO THE AREA FROM THE OHIO RIVER VALLEY. LIKELY BLANKET OF MID- TO HIGH-LEVEL CLOUDS AND WET WEATHER WILL KEEP CONDITIONS MILD TOWARDS SHORES WITH LOWS AROUND THE MID-40S. ELSEWHERE...GRADUAL CLEARING EXPECTED W TO E AS W-WINDS DRIVE COOLER AND DRIER AIR ACROSS THE REGION. COOLEST CONDITIONS N AND W YET WINDS /MENTIONED BY THE PREVIOUS FORECASTER/ WILL LIKELY LIMIT EFFECTIVE RADIATIONAL COOLING. EXPECTING LOWS AROUND THE UPPER-30S.
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&& .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
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THURSDAY... HIGH PRESSURE CONTINUES TO BUILD E. SUBSIDENCE AND SINKING AIR IN CONTROL OF THE REGIONS WEATHER. WITH A COOLER AIRMASS CONTINUING TO BUILD WITHIN THE LOW-LEVELS /H85 JUST BELOW THE FREEZING MARK/ EXPECT A WELL-MIXED BOUNDARY-LAYER ALLOWING FOR DRIER AIR TO MIX- DOWN /DEWPOINTS INTO THE MID-30S/ AND DEVELOPMENT OF A SCATTERED CUMULUS DECK AROUND 5-6 KFT. HIGHS AROUND THE 50S EXPECTED WHICH IS JUST ABOUT NORMAL FOR THIS TIME OF YEAR ACROSS SOUTHERN NEW ENGLAND. LIGHT WESTERLY WINDS. THURSDAY NIGHT... HIGH PRESSURE ACROSS NEW ENGLAND. LIGHT AND VARIABLE WINDS. COLD AIRMASS BELOW FREEZING REMAINS ALOFT. A GOOD CASE FOR EFFECTIVE RADIATIONAL COOLING...THAT IS IF CLOUDS DO NOT BECOME AN ISSUE. CONSIDERING DEWPOINTS AROUND THE MID-30S ON THURSDAY...IT IS POSSIBLE LOCATIONS COULD COOL BELOW THE CROSSOVER THRESHOLD IF THE CONDITIONS ARE RIGHT AND WE ARE ALLOWED TO RADIATE OUT EFFECTIVELY. BUT BENEATH CYCLONIC FLOW THROUGH WHICH WEAK IMPULSES WILL GLIDE... THERE IS ALWAYS THAT POTENTIAL FOR ENHANCEMENT OF MID-LEVEL LIFT AND CONVERGENCE YIELDING A BLANKETING CLOUD BASE. IF CONDITIONS REMAIN CLEAR...THERE IS ENOUGH CONFIDENCE TO SPECULATE THAT SHALLOW GROUND FOG WILL DEVELOP WHEREVER SOILS ARE SATURATED /I.E. SWAMPY BOGS/. LOWS WOULD BOTTOM DOWN AROUND THE MID-30S...LOW- 30S FOR THOSE AREAS THAT RADIATE. WARMEST CONDITIONS ALONG THE SHORES. BUT WILL GO CONSERVATIVE WITH THIS FORECAST CONSIDERING THE POTENTIAL FOR MID-LEVEL CLOUD DECKS AND HOLD WITH LOWS AROUND THE UPPER-30S. WILL NEED TO MONITOR FOR FROST / FREEZE HEADLINES MAY BE NECESSARY FOR S/E COASTAL MA AND RI.
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&& .LONG TERM /FRIDAY THROUGH WEDNESDAY/...
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*** LONG-TERM DISCUSSION FROM OVERNIGHT SHIFT *** *** FORECAST DISCUSSION STILL UNDER DEVELOPMENT *** 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.
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&& .AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/...HIGH CONFIDENCE. MAINLY VFR. LOW-END VFR/MVFR WITH LINE OF -RA EXPECTED TO SWEEP THE TERMINALS INTO THIS EVENING AHEAD OF WHICH SW-WINDS PREVAIL GUSTING AROUND 20-25 KTS ALONG THE S/SE SHORELINE. AN ISOLATED TSRA IS POSSIBLE OVER SE-TERMINALS...BUT NOT ENOUGH CONFIDENCE TO PREVAIL IN TAF. TONIGHT...WINDS BACK W BEHIND THE LINE...DIMINISHING. MAINLY VFR. LOW-END VFR/MVFR CIGS WITH -RA LINGER OVER S AND E TERMINALS INTO MIDNIGHT...IMPROVING AFTER AS ACTIVITY PUSHES OFFSHORE. THURSDAY...VFR. LIGHT W-WINDS. SCT CIGS 4-5 KFT ACROSS INTERIOR TERMINALS. THURSDAY NIGHT...VFR. LIGHT/VRB WINDS. SKC. SHALLOW PATCHY GROUND FOG POSSIBLE AT PRONE TERMINALS. KBOS...HIGH CONFIDENCE IN TAF. KBDL...HIGH CONFIDENCE IN TAF. OUTLOOK...FRIDAY THROUGH SUNDAY... 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.
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&& .MARINE...
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FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH THURSDAY NIGHT/...HIGH CONFIDENCE. WINDS STILL AN ISSUE ALONG THE S/SE COASTLINE WITH GUSTS UP TO 25 KTS AND WILL REMAIN SO AHEAD OF THE COLD FRONT WHICH WILL SWEEP ACROSS THE WATERS THIS EVENING. WINDS BACK W AND DIMINISH ALONG WITH THE CHANCE OF SHOWERS TOWARDS THURSDAY MORNING. SHOULD SEE SEAS GRADUALLY DIMINISH BELOW SMALL-CRAFT THRESHOLDS UNDER LIGHT W-WINDS AS HIGH PRESSURE BUILDS INTO THE REGION OVERNIGHT INTO THURSDAY. MUCH OF THE DAY THURSDAY...AND ONTO THURSDAY NIGHT... LOOKS LIKE GOOD BOATING WEATHER. OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE. 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.
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&& .BOX WATCHES/WARNINGS/ADVISORIES... 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. && $$ SYNOPSIS...BELK/SIPPRELL NEAR TERM...SIPPRELL SHORT TERM...SIPPRELL LONG TERM...BELK AVIATION...BELK/SIPPRELL MARINE...BELK/SIPPRELL

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