Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Graphics & Text | 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 050848 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 348 AM EST THU MAR 5 2015 .SYNOPSIS...
-- Changed Discussion --
A COLD FRONT WILL EXIT THE COASTAL WATERS AROUND DAYBREAK THEN STALL SOUTH OF NEW ENGLAND WHILE WEAK LOW PRESSURE TRAVELS ALONG THE FRONT TODAY. THIS WILL BRING SNOW TO SOUTHERN PORTIONS OF THE FORECAST AREA THROUGH THE DAY. HIGH PRESSURE WILL BUILD IN FOR FRIDAY THROUGH THIS WEEKEND...BRINGING DRY CONDITIONS WITH COLDER THAN NORMAL TEMPERATURES. A COUPLE OF WEAK COLD FRONTS MAY SLIP THROUGH WITH WIDELY SCATTERED SNOW SHOWERS SATURDAY NIGHT AND MONDAY.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
315 AM UPDATE... A COLD FRONT STRETCHED FROM CAPE COD BAY TO JUST EAST OF BLOCK ISLAND RI AT 3 AM. RAIN JUST CHANGED TO SNOW IN THE PAST FEW MINUTES HERE AT TAUNTON. TEMPERATURES WERE SLOWLY FALLING INTO THE LOWER 30S BEHIND THE FRONT AND IT IS NOW BELOW FREEZING IN THE BERKSHIRES. HOWEVER...DEWPOINTS WERE DRAMATICALLY FALLING...WITH READINGS IN THE MID TEENS TO LOWER 20S INDICATING MUCH DRIER AIR FLOWING INTO NORTHERN AND WESTERN MA. TOUGH FORECAST BECAUSE SATELLITE IMAGERY SHOWS A VERY MOIST CONTINUOUS FEED FROM THE WESTERN GULF OF MEXICO TO NEW ENGLAND. THUS...THE PRECIPITATION...WHICH WILL BE CHANGING OVER TO SNOW BY DAYBREAK...SHOULD CONTINUE FOR MUCH OF THE DAY TODAY ALONG THE SOUTH COAST OF RI AND MA. HOWEVER...FARTHER TO THE NORTH WHERE THE DRIER AIR IS MOVING IN...IT NOW LOOKS LIKE BOSTON...WORCESTER..AND SPRINGFIELD MAY NOT RECEIVE ANY SNOW. A FEW FLURRIES AT BEST. NEW WPC SNOWFALL GRAPHIC CONFIRMS THIS THINKING. AFTER THE MILD DAY YESTERDAY...TODAY WILL FEEL MUCH COLDER. 850 MB TEMPERATURES WILL BE PLUNGING TO TEMPERATURES WILL BE FALLING FROM NEAR 0C THIS MORNING TO -15C BY EVENING. SURFACE TEMPERATURES WILL DROP INTO THE 20S AND MAY HOLD STEADY FOR A WHILE DURING THE DAY BEFORE PLUNGING TONIGHT. NORTHWEST WINDS MAY BE INITIALLY GUSTY THIS MORNING BEHIND THE FRONT BUT AM NOT EXPECTING IT TO BE A WINDY DAY. MODEL QPF IS QUITE CONSISTENT FOR SOUTHERN RI AND S COASTAL MA...WITH TOTALS BETWEEN 0.50 AND 0.75 INCHES...SOME OF WHICH HAS BEEN IN THE FORM OF RAIN AND SLEET. STILL DO GET COMPUTATIONS OF 2 TO 5 INCHES ALONG THE SOUTH COASTS OF RI AND MA AND 4 TO 6 INCHES OVER THE ISLANDS...FROM BLOCK ISLAND EASTWARD TO NANTUCKET. WILL KEEP THE WINTER WEATHER ADVISORY IN PLACE FROM SOUTHERN RI EASTWARD TO CAPE COD. BIG QUESTION HAS BEEN WHETHER TO LOWER THE WINTER STORM WARNING TO AN ADVISORY FOR THE ISLANDS. TECHNICALLY ONE NEEDS AN AVERAGE OF 6 INCHES. HOWEVER...SINCE WE DO HAVE VERY CLOSE TO THOSE AMOUNTS...HAVE DECIDED TO LEAVE THE WARNING IN PLACE AS WELL. ONE COULD ARGUE THAT THERE WILL BE SOME ADDITIONAL IMPACT OF A LAYER OF ICE AS THE RAIN FREEZES WITH FALLING TEMPERATURES.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
-- Changed Discussion --
CLEARING SETS IN ACROSS ALL OF REGION TONIGHT AS SYSTEM HEADS FARTHER OUT TO SEA AND VERY STRONG HIGH PRESSURE BUILDS INTO THE OHIO VALLEY AND APPALACHIAN REGION. CLEAR SKIES AND NORTHERLY WINDS WILL SPELL ANOTHER BITTERLY COLD NIGHT. WINTER IS NOT OVER YET. OVERNIGHT LOW TEMPERATURES WILL RANGE FROM FROM ABOUT 2 BELOW TO 5 ABOVE ACROSS THE INTERIOR...TO THE TEENS CLOSER TO COAST. NAM SEEMS TO BE CAPTURING THE MAGNITUDE OF THE COLD AIR OVER THE OCEAN WATERS THE BEST WITH 925 MB WINDS UP TO 25-30 KT AND SWANNAM SHOWING SEAS BUILDING TO 4 TO 6 FT OVER THE EASTERN MA WATERS. SURFACE WINDS COULD HAVE GUSTS TO 20-28 KT OVER THE WATERS. HAVE ISSUED A FREEZING SPRAY ADVISORY FOR THE NORTHEAST MA COASTAL WATERS FOR TONIGHT. A SUNNY BUT COLD DAY IS FORECAST FOR FRIDAY AS HIGH PRESSURE CENTERED OVER DELMARVA RIDGES NORTHEASTWARD ACROSS SOUTHERN NEW ENGLAND. HIGHS ONLY IN THE 20S WITH LIGHT WINDS.
-- End Changed Discussion --
&& .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... BIG PICTURE... BROAD TROUGH OVER THE EASTERN USA DURING THE WEEKEND WITH BELOW NORMAL CONTOUR HEIGHTS OVER NEW ENGLAND. THIS FEATURE FLATTENS DURING NEXT WEEK WITH CONTOUR HEIGHTS RETURNING TO NEAR NORMAL OR A LITTLE ABOVE. THIS SUGGESTS COOLER THAN NORMAL WEATHER OVER THE WEEKEND TRENDING CLOSER TO NORMAL DURING THE WEEK. THE WEATHER-SUPPORTING FEATURES WILL BE GUIDED BY WEAK SHORTWAVES IN THE FLOW. AS SUCH...CONFIDENCE IS LOW IN THE TIMING OF THESE SHORTWAVES. TO MINIMIZE THIS...WE USED A BLEND OF MODEL DATA. THE DAILIES... FRIDAY NIGHT-SATURDAY... HIGH PRESSURE MOVES OFFSHORE FRIDAY NIGHT SETTING UP A WEST- SOUTHWEST FLOW ACROSS NEW ENGLAND. ANOTHER NORTHERN STREAM SHORTWAVE DIVES SOUTH FROM NORTHERN CANADA TO THE GREAT LAKES SATURDAY AND NEW ENGLAND SATURDAY NIGHT. LIMITED JET SUPPORT WITHIN THE NORTHERN STREAM WHILE HIGH PRESSURE ACROSS THE SOUTH BLOCKS ANY INFLOW OF MOISTURE INTO THE NORTHERN SYSTEM. EXPECT AN INCREASE IN SKY COVER SATURDAY AND MAYBE SOME ISOLATED SNOW SHOWERS. SUNDAY THROUGH WEDNESDAY... SAME STORY EVERY COUPLE OF DAYS. ANOTHER NORTHERN SHORTWAVE AND SURFACE COLD FRONT MAY BRING SCATTERED OR ISOLATED SNOW SHOWERS. HIGH PRESSURE IN PLACE TO OUR SOUTH WILL AGAIN BLOCK INFLOW OF ANY SIGNIFICANT PCPN. AN INVERTED TROUGH SOUTH OF THE HIGH AND ALONG THE GULF OF MEXICO SUGGESTS THAT THE MOISTURE IS THERE TO BE TAPPED...JUST THAT IT IS BEING PUSHED EAST OUT TO SEA TO OUR SOUTH. SO THIS IS A GENERALLY DRY PERIOD WITH A MODERATING TREND ON TEMPERATURES. && .AVIATION /08Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY/...MODERATE CONFIDENCE TODAY. HIGH CONFIDENCE TONIGHT AND FRIDAY. IFR AND MVFR CONDITIONS IN LIGHT TO OCCASIONALLY MODERATE SNOW ACROSS SOUTHERN PORTIONS OF THE REGION...MAINLY SOUTH OF A LINE FROM IJD-SFZ-TAN-GHG. THESE CONDITIONS PERSIST MOST OF THE DAY. ELSWEHERE VFR TO OCCASIONAL MVFR CIG NORTH OF THAT LINE. SKIES BEGIN TO CLEAR FROM NW TO SE LATE THIS AFTERNOON...REACHING CAPE COD AND NANTUCKET THIS EVENING. CLEAR SKIES EXPECTED LATER TONIGHT THROUGH FRI. EXPECTED GENERAL SNOW ACCUMULATIONS TODAY... BOS/BAF/BDL/BED/ORH...NO ACCUMULATION. PVD...2 INCHES FMH/HYA...3-4 INCHES ACK...4-6 INCHES KBOS TAF...HIGH CONFIDENCE. KBDL TAF...HIGH CONFIDENCE. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...MODERATE CONFIDENCE. VFR. BRIEF MVFR CIGS/VSBYS POSSIBLE SATURDAY IN WIDELY SCATTERED SNOW SHOWERS.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY/...MODERATE CONFIDENCE. SMALL CRAFT ADVISORIES HAVE BEEN EXTENDED INTO MID-MORNING ON FRIDAY FOR THE OUTER WATERS. A SMALL CRAFT ADVISORY IS IN EFFECT FOR MASS BAY AND IPSWICH BAY AND FOR BLOCK ISLAND/RI SOUNDS THROUGH TONIGHT. SEAS WILL BUILD TO 5 TO 6 FEET OVER THE OUTER WATERS AND EVEN INTO A PORTION OF CAPE COD BAY AS WELL AS BLOCK ISLAND/RHODE ISLAND SOUNDS. A FREEZING SPRAY ADVISORY HAS BEEN POSTED FOR THE WATERS EAST OF CAPE ANN AND EAST OF BOSTON FOR TONIGHT. TEMPERATURES IN THE TEENS MAY COMBINE WITH NORTHERLY WIND GUSTS TO 20 TO 28 KT TO CREATE MODERATE FREEZING SPRAY WHICH COULD BE A DANGER TO MARINERS. A COLD FRONT WAS MOVING OFF OF CAPE COD AS OF 3 AM AND IT WILL BE EXITING THE COASTAL WATERS EARLY THIS MORNING...THEN STALL AS LOW PRESSURE TRAVELS ALONG THE FRONT. RAIN WILL CHANGE TO SLEET AND SNOW TOWARD DAYBREAK. SNOW WILL CONTINUE ACROSS THE SOUTHERN COASTAL WATERS THROUGH MUCH OF THE DAY BEFORE HEADING OFFSHORE TONIGHT. STRONG HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST AND THIS MAY CAUSE A PERIOD OF 25 KT NW TO N WIND GUSTS TONIGHT...MAINLY ON THE EASTERN OUTER WATERS. FRIDAY...NORTH WINDS BEGIN TO SHIFT TO THE SOUTHWEST. WINDS BELOW 25 KNOTS. SEAS LESS THAN 5 FEET. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...MODERATE CONFIDENCE. FRIDAY NIGHT AND SATURDAY...INCREASING SOUTHWEST WIND WITH FREQUENT GUSTS TO 25 KNOTS POSSIBLE BY SAT AFTERNOON AND EVENING. SEAS BUILD TO 3-5 FEET ON THE OUTER WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED. SUNDAY-MONDAY...WINDS BELOW 25 KNOTS. SEAS GENERALLY BELOW 5 FEET...ALTHOUGH OCCASIONAL 5 FOOT SEAS POSSIBLE ON THE OUTER WATERS.
-- End Changed Discussion --
&& .BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE. MA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MAZ023- 024. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MAZ020>022. RI...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR RIZ008. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR RIZ003>007. MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 7 AM EST FRIDAY FOR ANZ231-251. SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 10 AM EST FRIDAY FOR ANZ250-254>256. FREEZING SPRAY ADVISORY FROM 8 PM THIS EVENING TO 5 AM EST FRIDAY FOR ANZ250-251.
-- End Changed Discussion --
&& $$ SYNOPSIS...WTB/GAF NEAR TERM...GAF SHORT TERM...GAF LONG TERM...WTB AVIATION...WTB/GAF MARINE...WTB/GAF

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