Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 111332 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 932 AM EDT FRI APR 11 2014 .SYNOPSIS... A WEAK COLD FRONT WILL MOVE ACROSS NEW ENGLAND TODAY AND STALL ALONG THE SOUTH COAST TONIGHT. A WAVE OF LOW PRESSURE WILL MOVE ALONG THE FRONT AND PASS SOUTH OF NEW ENGLAND...BRINGING A CHANCE OF SHOWERS TONIGHT. DRY AND PROGRESSIVELY MILDER CONDITIONS ARE EXPECTED OVER THE WEEKEND AND MONDAY. A SLOW MOVING FRONT WILL BRING A SOAKING RAIN SOMETIME TUESDAY AND WEDNESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
930 AM UPDATE... FORECAST TRENDS REMAIN ON TRACK FOR THIS MORNING. A COLD FRONT WAS JUST ENTERING NORTHWEST MA AND SOUTHERN NH. RADAR MOSAICS SHOWING FIRST BATCH OF RAINFALL MOVING OFF THE COAST. THERE IS ANOTHER BATCH OF SHOWERS DEVELOPING ACROSS EASTERN PA...WHICH IS EXPECTED TO MOVE EAST INTO OUR REGION LATER THIS AFTERNOON AND EVENING. SO FAR...RAINFALL AMOUNTS HAVE BEEN VERY LIGHT. ANY ADDITIONAL RAINFALL IS EXPECTED TO BE LIGHT AS WELL. MAIN CHANGES WERE TO TWEAK NEAR TERM CONDITIONS TO BRING THEM IN LINE WITH OBSERVED TRENDS. PREVIOUS DISCUSSION... TODAY... BROAD AREA OF SPRINKLES/LIGHT RAIN IN CENTRAL/WESTERN NY. ONCE THE SHOWERS MOVE IN...EXPECT OCCASIONAL SPRINKLES THROUGH THE MORNING AND MIDDAY. THE COLD FRONT BECOMES MORE ALIGNED WITH THE UPPER FLOW TODAY AND SLOWS AS IT MOVES OVER OUR AREA. CROSS SECTIONS SHOW A DEEP COLUMN OF MOISTURE AND PW VALUES AROUND AN INCH. THIS SUGGESTS ENOUGH MOISTURE FOR SHOWERS. A GOOD 850 MB CONVERGENCE/250 MB DIVERGENCE COUPLET MOVES ACROSS LATE IN THE DAY...WHICH WOULD ALSO SUPPORT SHOWERS. WE WILL BRING INCREASING POPS DURING THE LATTER PART OF THE AFTERNOON. TEMPS AT 850 MB WILL BE 4-6C. WITH FULL MIXING TO 850 MB TEMPERATURES WOULD REACH THE MID AND UPPER 60S. CLOUDS SHOULD BE THICK ENOUGH TO HOLD BACK FULL MIXING...SO WE WILL FORECAST LOW TO MID 60S. WITH MORE SUNSHINE AND DEEPER MIXING 70 MAY BE POSSIBLE...BUT THIS IS A LOWER PROBABILITY.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... TONIGHT... UPPER SHORTWAVE MOVES FROM THE GREAT LAKES THIS EVENING TO NEW ENGLAND BY SUNRISE SATURDAY. UPPER JET SUPPORTING THE SHORTWAVE MOVES ACROSS NEW ENGLAND OVERNIGHT WITH SOUTHERN NEW ENGLAND IN THE RIGHT ENTRANCE REGION OF THE JET. THIS WILL GENERATE UPPER VENTING OVER OUR AREA AND ESPECIALLY OVER THE STALLED COLD FRONT...AND HELP GENERATE A WAVE OF LOW PRESSURE ALONG THE FRONT. SUFFICIENT LIFT AND MOISTURE TO GENERATE RAIN/SHOWERS ACROSS OUR AREA WITH PREFERENCE FOR CT/RI/SE MASS. HIGHEST POPS WILL BE IN THE VICINITY OF THE STALLED FRONT WITH MAX VALUES 60-65 PCT. THE WAVE AND ITS UPPER SUPPORT MOVE EAST OF CAPE COD BY 12Z...SO POPS SHOULD BE DIMINISHING BY THAT TIME. SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION BRINGING CLEARING AND DRY WEATHER. MIXING SHOULD REACH TO 850 MB...WHERE TEMPS WILL BE AROUND 3C. THIS SHOULD SUPPORT MAX TEMPS IN THE LOW TO MID 60S. EVEN A DEEPER MIXING TO 800 MB WOULD SUPPORT MID 60S. WIND FIELDS WILL BE LIGHT...WHICH WOULD ALLOW SEABREEZES TO DEVELOP NEAR THE COASTS. TEMPS IN THESE AREAS SHOULD BE IN THE UPPER 40S AND 50S. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... * ABOVE AVERAGE TEMPERATURES ARE EXPECTED ON SUNDAY/MONDAY * STRONG COLD FRONTAL PASSAGE NEXT TUES/WED * BELOW AVERAGE TEMPERATURES RETURN FOR THE REMAINDER OF THE WORK WEEK MODELS AND CONFIDENCE... HAVE HIGH CONFIDENCE IN THE WARMING TREND IN THE FORECAST OVER THE WEEKEND WITH A MODERATE CONFIDENCE FOR THE TIMING POTENTIAL FOR THE SYSTEM NEXT WEEK. INCREASING CONFIDENCE THAT PRECIP WILL OCCUR OVER THE MID-WEEK SYSTEM BUT THE EXACT TIMING AND LOCATION OF MODERATE RAINFALL ARE STILL UNCERTAIN. FINALLY BELIEVE THAT TEMPS WILL DROP BELOW AVERAGE BY WEDNESDAY/THURSDAY. STILL SOME UNCERTAINTY LEADING UP TO NEXT WEEK AS STRONG TROUGH DIGS TOWARDS THE NORTHEAST. OVERALL 00Z MODEL GUIDANCE IS IN GOOD AGREEMENT. THE RE- AMPLIFICATION OF THE UPPER PATTERN WILL TAKE SHAPE LATE THIS WEEKEND INTO NEXT WEEK. UPPER RIDGING WILL BUILD OVER SE ALASKA/NW CANADA AS WELL AS ACROSS THE NORTHEAST...FAVORING DIGGING TROUGHING OVER THE CENTRAL CONUS. THIS WILL SUPPORT A STRENGTHENING SURFACE FRONTAL BOUNDARY THAT WILL SLOWLY MARCH EASTWARD TOWARDS NEW ENGLAND BY TUES/WED. THE DETERMINISTIC AND ENSEMBLE GUIDANCE CONTINUE TO SHOW BETTER AGREEMENT ON THE EVOLUTION OF THIS SYSTEM...WITH BOTH THE DETERMINISTIC GFS/EC IN GOOD AGREEMENT. IN THE WAKE OF THIS FRONT HIGH PRESSURE SHOULD SETTLE OVER/NEAR NEW ENGLAND WITH ENOUGH GRADIENT SURROUNDING IT TO SUPPORT BREEZY CONDS AWAY FROM THE HIGH CENTER. TEMPS SHOULD MODERATE TO WITHIN 10F OF NORMAL BY LATE NEXT WEEK. HAVE TRENDED THIS FORECAST TOWARDS PREVIOUS FORECAST AND WPC. DETAILS... SATURDAY NIGHT INTO MONDAY... HIGH PRESSURE WILL EXIT OFFSHORE BY SUNDAY MORNING AS A FRONTAL SYSTEM TO THE NORTH OF THE REGION BEGINS TO MOVE TOWARDS SOUTHERN NEW ENGLAND. THIS FRONT WILL STALL BEFORE REACHING SOUTHERN NH AND THEN MOVE NORTHWARD BY MONDAY AS A WARM FRONT. RETURN FLOW TO THE REGION WILL ALLOW FOR GOOD WAA ON BOTH SUNDAY AND MONDAY. DURING THE DAY...A GOOD AMOUNT OF MIXING WILL OCCUR AND WITH 850MB TEMPS AT 8C ON SUNDAY AND 12C ON MONDAY...HIGH TEMPERATURES WILL FLIRT WITH 70F ON SUNDAY TO MID TO UPPER 70S ON MONDAY. IF THE ATMOSPHERE IS SUPER ADIABATIC THEN TEMPERATURES MAY REACH 80F ON MONDAY. ON CAVEAT IS FOR THOSE ALONG THE SOUTH COASTLINE...SOUTHERLY WINDS WILL BRING THE COOL MARITIME AIR ONSHORE KEEP TEMPS IN THE 50S TO LOW 60S ON BOTH DAYS. BECAUSE OF THE MIXING...WINDS WILL BE GUSTY...NEAR 20-30 MPH. ONCE THE WINDS LIGHTEN UP DURING THE OVERNIGHT HOURS...COMBINED WITH THE SOUTHERLY WINDS...ANTICIPATE FOG DEVELOPMENT ESP ALONG THE SOUTH COAST. FINALLY THERE IS A LOW PROBABILITY THAT A FEW SHOWERS MAY DEVELOP ACROSS THE HIGH TERRAIN ON MONDAY DUE TO DIABATIC HEATING. AM NOT ANTICIPATING ANY STRONG OR SEVERE STORMS BUT PERHAPS A RUMBLE OF THUNDER OR TWO. BECAUSE OF THIS UNCERTAINTY LEFT IT OUT OF THE FORECAST FOR NOW BUT IT IS SOMETHING THE BEARS WATCHING. TUESDAY INTO WEDNESDAY.... GUIDANCE IS BEGINNING TO CLUSTER MORE TOGETHER ON THE TIMING AND INTENSITY OF THE APPROACHING COLD FRONTAL SYSTEM. THE LATEST 00Z MODELS INDICATE THAT A LOW PRESSURE SYSTEM WILL DEVELOP ALONG THE SLOW MOVING COLD FRONT BY TUESDAY NIGHT FOLLOWED BY STRONG HIGH PRESSURE BY WED NIGHT. ANTICIPATE A FEW SHOWERS TO DEVELOP AHEAD OF THE FRONT MONDAY NIGHT INTO TUESDAY. BUT AS SOON AS THE FRONT APPROACHES...EXPECT MODERATE TO POSSIBLY HEAVY PRECIP TO FALL. THIS PRECIP MAY CAUSE URBAN AND POOR DRAINAGE FLOODING...BUT MAY ALSO HELP ELEVATED THE RIVERS IF EVERYTHING LINES UP. HOWEVER WE WILL NEED TO MONITOR THIS POTENTIAL CLOSELY. BOTH AHEAD AND BEHIND THE FRONT...A VERY STRONG LLJ WILL DEVELOP WHICH WILL NOT ONLY AID IN THE MOISTURE TRANSPORT ALONG THE FRONT BUT WILL ALSO CREATE GUSTY WINDS THROUGH THE PERIOD. WIND GUSTS OF 20 TO 30 MPH ARE EXPECTED AHEAD OF THE FRONT BUT PERHAPS EVEN STRONGER GUSTS COULD OCCUR AS 925MB WINDS SPEEDS STRENGTHEN TO 60-80KTS. THIS WILL RESULT IN A POSSIBLE WIND ADV IF WE MIX ALL THE WAY TO 925MB. VERY STRONG CAA WILL OCCUR AS THE FRONT PASSES THROUGH BY WED. APPEARS THAT THE COLD AIR WILL RUSH INTO THE AREA WITH PRECIP LINGERING BEHIND THE SYSTEM. THIS WILL RESULT IN SOME P-TYPE ISSUES ESP ACROSS THE BERKSHIRES AND IN SOUTHERN NEW HAMPSHIRE. LASTLY WITH THE STRONG ONSHORE FLOW FROM THE SOUTH...WE WILL NEED TO WATCH FOR THE POTENTIAL FOR SOME MINOR SPLASHOVER ALONG THE SOUTH SHORE AND INTO NARRAGANSETT BAY. TIDES ARE SLOWLY INCREASING WITH HIGH ASTRONOMICAL TIDE PEAKING NEXT FRIDAY/SATURDAY. AS ONE CAN SEE THERE ARE A LOT OF HAZARDS THAT THIS STORM CAN POTENTIALLY DEVELOP. ALTHOUGH CONFIDENCE IS STILL A LITTLE UNCERTAIN...ESP SINCE THIS STORM IS STILL 5 DAYS AWAY...IT IS LOOKING LIKE A POTENT SPRING STORM WILL AFFECT THE EASTERN STATES NEXT WEEK. THURSDAY... STRONG HIGH PRESSURE WILL QUICKLY USHER INTO THE REGION BEHIND THE COLD FRONT. TEMPERATURES WILL DROP WELL BELOW AVERAGE WITH HIGH JUST REACHING 50F. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY NIGHT/... TODAY...VFR IN CLOUDS AND LIGHT SHOWERS. A BRIEF PERIOD OF MVFR CIGS/VSBYS POSSIBLE IN SHOWERS LATE IN THE DAY ESPECIALLY OVER CT AND RI. LLWS WILL SLOWLY DISSIPATE BY LATE MORNING. THERE IS A MODERATE PROBABLY FOR SEA BREEZE DEVELOPMENT ALONG BOTH FRONTS. TONIGHT...A PERIOD OF 2000 FOOT CIGS AND 4-5 MILE VSBYS IS POSSIBLE IN RAIN SHOWERS...MOSTLY ACROSS CT/RI/SE MASS. THERE IS A LOW CHANCE OF DENSE FOG FORMING ALONG THE SOUTH COAST. SATURDAY...SHOWERS AND ANY MVFR CONDITIONS SHOULD MOVE OFFSHORE EARLY IN THE DAY. CAPE COD AND ISLANDS WOULD BE THE LAST TO EXPERIENCE THESE CONDITIONS. EXPECT VFR IN CLEARING SKIES. NORTH TO NORTHWEST WINDS IN THE MORNING SHOULD BECOME LIGHT/VARIABLE BY AFTERNOON. POTENTIAL SEA BREEZES DEVELOPING IN THE AFTERNOON. KBOS TERMINAL...HIGH CONFIDENCE IN TAF TONIGHT AND FRIDAY. SEA BREEZE DEVELOPMENT IS POSSIBLE. KBDL TERMINAL...HIGH CONFIDENCE IN TAF TONIGHT AND FRIDAY. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT...MODERATE CONFIDENCE. LOW CLOUDS AND PATCHY FOG MAY MOVE ONSHORE ALONG S COAST WITH LOCAL IFR CIGS/VSBYS. SUNDAY...MODERATE CONFIDENCE. MAINLY VFR. LOCAL MVFR-IFR CIGS/VSBYS ALONG S COAST IN LOW OCEAN CLOUDS AND PATCHY FOG WHICH SHOULD IMPROVE BY MIDDAY. EXPECT S WINDS TO INCREASE DURING THE AFTERNOON...GUSTING TO AROUND 25 KTS. MAY SEE LOW CLOUDS/PATCHY FOG RETURN AFTER MIDNIGHT ALONG S COAST WITH MVFR-IFR CONDITIONS. MONDAY...MODERATE CONFIDENCE. LOCAL MVFR-IFR CIGS/VSBYS ALONG S COAST EARLY MON SHOULD IMPROVE...OTHERWISE VFR ON MONDAY. GUSTY S-SW WINDS IN PLACE...UP AROUND 30 KTS. TUESDAY...LOW CONFIDENCE. MAINLY VFR WITH SOME MVFR IN ISOLATED SHOWER DEVELOPMENT AHEAD OF APPROACHING COLD FRONT. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY NIGHT/...HIGH CONFIDENCE. TODAY...A WEAK COLD FRONT SWINGS ACROSS THE WATERS AND STALLS. STRONG SOUTHWEST WIND EARLY THIS MORNING WITH GUSTS 20-25 KNOTS. THE WIND WILL DIMINISH THROUGH THE DAY AND WILL SPEND MOST OF THE DAY BELOW 25 KNOTS. MEANWHILE SEAS WILL LINGER AT 5-7 FEET ON THE OUTER WATERS AND PARTS OF THE RI WATERS. TONIGHT... STALLED FRONT NEAR THE SOUTH COAST OF MASS AND RI. THE WIND FIELD NEAR THIS FRONT WILL BE LIGHT. SWELL WILL CONTINUE AROUND 5 FEET ON THE SOUTHERN OUTER WATERS AND PARTS OF THE RI WATERS. ALSO SOME POTENTIAL FOR LOW VSBYS IN FOG OVERNIGHT. SATURDAY...HIGH PRESSURE BUILDS IN WITH A LIGHT WIND FIELD. SWELL OF 5 FEET WILL STILL LINGER ON THE OUTER WATERS AND SOME OF THE RI WATERS. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SATURDAY NIGHT...HIGH CONFIDENCE. VSBY RESTRICTION LATE SAT NIGHT ON THE OUTER WATERS IN PATCHY FOG. SUNDAY...MODERATE CONFIDENCE. LIGHT/VRBL WINDS SHIFT TO SE-S DURING SUNDAY. WILL INCREASE... GUSTING TO AROUND 25 KT. EXPECT SEAS TO BUILD AS WELL. VSBY RESTRICTIONS IN PATCHY FOG. MONDAY-TUESDAY...MODERATE CONFIDENCE. EXPECT S-SW WINDS TO GUST UP TO 30 KT WITH SEAS INCREASING IN RESPONSE ESP ON THE SOUTHERN OUTER WATERS. VSBY RESTRICTIONS DURING THE OVERNIGHT AND EARLY MORNING HOURS IN PATCHY FOG...THEN SHOWERS MOVE IN ON TUE. && .HYDROLOGY... SNOWMELT AND RUNOFF FROM NORTHERN NEW ENGLAND HAS THE CONNECTICUT RIVER RUNNING HIGH. LATEST PROJECTIONS KEEP THE RIVER JUST BELOW MINOR FLOOD STAGE AT HARTFORD AND AT MIDDLE HADDAM THROUGH THE MORNING. HOWEVER...IT IS STILL POSSIBLE THAT TIDE FLUCTUATIONS COULD PUSH THE LOCATIONS INTO VERY BRIEF MINOR FLOODING. NO HEADLINES WILL BE ISSUED THIS TIME...BUT WILL HAVE TO CONTINUE TO CLOSELY MONITOR. WORST CASE SCENARIO WOULD BE VERY MINOR FLOODING. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ235-237- 254>256. SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ250. && $$ SYNOPSIS...WTB/DUNTEN NEAR TERM...WTB/BELK/DUNTEN SHORT TERM...WTB LONG TERM...DUNTEN AVIATION...WTB/DUNTEN MARINE...WTB/DUNTEN HYDROLOGY...STAFF

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