Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 162036 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 436 PM EDT Fri Mar 16 2018 .SYNOPSIS... Mainly dry but unseasonably cold weather will continue this weekend into at least Monday. The potential continues for a Noreaster sometime between next Tuesday into Thursday, but confidence on if/how we are impacted remains highly uncertain. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Still noting bands of snow/rain showers across the E slopes of the Berkshires which thin out across the interior, then reappear across Cape Cod and the islands at 1945Z as seen on NE regional 88D radar. A couple of spotty bands are seen better on KBOX radar, one across interior Essex and NE Middlesex counties, with a second weaker one across central Mass, mainly across western Worcester county into eastern portions of the CT valley. With such a wide temp/dewpoint spread, would be tough for some precip to reach the ground but can`t rule this out so kept slight chance POPs going through 00Z then should move offshore and weaken with sunset. For tonight, decent low level lapse rates remain from between H9 and H95 as a 40-45 kt low level jet at H9 up to around 50 kt at H85 moves across the region through most of the night as it extends back into western Quebec and eastern Ontario. However, mixing is not that good at H85, but still pretty good below that level. Model suite guidance all signal gusty winds continuing through tonight as the elongated LLJ extends back into western Quebec into eastern Ontario, but the lapse rates drop off after around 09Z so may diminish somewhat toward daybreak. Core of cold air (down to about -25C to -27C) remains across central Quebec into Hudson Bay, but will still see a chunk of -13C to -15C air moves across. Expect skies to become mostly clear by around midnight, so even with the winds, temps will fall back to the mid teens to around 20 inland, ranging to the mid and upper 20s along the immediate coast. && .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... Saturday... As the H5 vortex continues to spin across Labrador, most of the model suite shows another cutoff mid level low that dived S out of Hudson Bay and moved into May Sat morning. This is a rather potent short wave, but most of the energy looks to push into the Gulf of Maine. Will see a piece of the energy move S across the region Sat in the form of a cold front. Will see some isolated to scattered snow showers push from N-S through mid afternoon, then should weaken as the mid level energy shifts offshore. A few spots might receive a dusting of snow during the day, not much more than 0.5 inches if that. The low level jet remains across the region, so will continue to see gusty W-NW winds, with gusts up to 25-30 kt along the coast, and 20-25 kt inland. May see a few gusts close to 35 kt along the coast through early afternoon. Conditions should improve after 18Z or so. Temps will be rather cold for St. Patrick`s Day, ranging from the mid and upper 20s across the higher terrain to between 35 and 40 across N CT/RI/SE Mass. Saturday night... Winds should finally diminish Sat evening, but temps more typically of mid winter will be in place as skies clear out. Will see lows in the single digits to lower teens well inland ranging to around 20 along the S coast. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Highlights... * Dry but unseasonably cold Sun/Mon * Potential Noreaster sometime next Tue into Thu but low confidence on if/how we are impacted Details... Sunday and Monday... Northwest flow aloft and at the surface will result in dry but unseasonably cold weather for this time of year. Low temperatures will mainly be in the teens to lower 20s. Highs mainly in the 30s...but some lower elevations may reach 40 on Monday. Tuesday through Thursday... We continue to watch the potential for a Noreaster to impact the region sometime in the Tuesday through Thursday time frame. Confidence though remains low as this is a very complex situation. Numerous pieces of shortwave energy are involved and their specific timing/strength and location will determine if/how our region is impacted. The models are also struggling with timing of the event as they appear unsure which piece of energy they want to amplify. Overall...there is not much more we can do at this point than indicate the potential for a Noreaster and run with chance pops over this time frame. We also need to keep all options on the table from a miss, to a wintry mix, or a significant snowstorm. Given this will likely be a few more days until we get a better handle on this situation. Needless to say though it does bear watching. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Saturday Night/...High confidence. Through 00Z... VFR. Areas of BKN clouds at around 5-6kft. Brief isold -SHRA/-SHSN will diminish toward sunset. NW winds gust up to 25-35 kt, highest along the coast and higher terrain. Tonight... VFR. W wind gusts up to 25-35 kt will linger across higher terrain and along the coast through most of the night, but will diminish this evening elsewhere. Saturday... VFR. W-NW winds gusting up to 25-30 kt, highest along coast and higher terrain. Band of BKN clouds around 4-5kft move across with another weak trough. Isold to SCT -SHSN possible from mid morning through the afternoon. Saturday night... VFR. Becoming CLR by midnight. W-NW wind gusts up to 25 kt diminishes in the evening. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Sunday through Wednesday/... Sunday through Monday Night: High confidence in VFR conditions. Tuesday: Low confidence. VFR conditions may deteriorate to MVFR-IFR thresholds late depending on the timing/track of a coastal storm which is highly uncertain. Chance SN, chance RA. Tuesday Night and Wednesday: Low confidence. MVFR/IFR conditions possible depending on the timing/track of a coastal storm. Windy with gusts to 30 to 40 kt possible along the coastal plain. Chance SN, chance RA. These conditions are highly uncertain and dependent on strength/timing of coastal low pressure. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Saturday Night/...High confidence. Through Saturday... W-NW winds will increase this evening, with gusts up to 30-35 kt over the open waters. The gusts may diminish briefly around sunrise, but will pick up again as a cold front approaches. Seas will run from 5 to 9 ft. Gale warnings remain on the open waters, with Small Crafts on the near shores. May see scattered snow showers into this evening before ending, then as the cold front approaches Sat morning, may see another round of scattered snow showers. May see brief visibility restrictions. Saturday night... Expect NW winds begin to diminish as the cold front moves offshore and high pressure ridge starts to build in from the NW. Gales will continue on the open waters through most of the night, but may lower to Small Crafts after midnight. Have continued that headline through most of the night. Small Crafts forecast to end around or after midnight on the near shore waters. Good visibility. Outlook /Sunday through Wednesday/... Sunday: Moderate to high confidence. Small Craft Advisory winds possible with gusts up to 30 kt. Areas of seas approaching 5 ft. Sunday Night: Moderate to high confidence. Small Craft Advisory winds possible with gusts up to 30 kt. Local rough seas. Monday through Monday Night: Moderate to high confidence.Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday: Low to moderate confidence depending on track/timing of a coastal storm. Winds less than 25 kt. Chance of snow, chance of rain. Visibility 1 to 3 nm. Tuesday Night and Wednesday: Low confidence. Potential for gale force winds with gusts between 35 and 45 kt. Rough seas up to 15 ft. Chance of rain, chance of snow. Visibility 1 to 3 nm. These potential conditions are highly uncertain and hinge on the track and strength of a potential coastal storm. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None.NW Gales continue mainly across the E waters with Small Craft Conditions lingering across the S waters. The Gales drop off by afternoon, with Small Craft Advisories following all waters thanks to both gusts/seas.MARINE...Small Craft Advisory until midnight EDT Saturday night for ANZ232>235-237. Small Craft Advisory until 7 AM EDT Sunday for ANZ230. Gale Warning until 5 AM EDT Sunday for ANZ231. Small Craft Advisory until 6 PM EDT Saturday for ANZ236. Gale Warning until 7 AM EDT Sunday for ANZ250-254. Gale Warning until 6 AM EDT Sunday for ANZ251. Gale Warning until 7 AM EDT Sunday for ANZ255-256. && $$ SYNOPSIS...Frank/EVT NEAR TERM...EVT SHORT TERM...EVT LONG TERM...Frank AVIATION...Frank/EVT MARINE...Frank/EVT is the U.S. government's official web portal to all federal, state and local government web resources and services.