Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 010803 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 403 AM EDT Sat Oct 1 2016 .SYNOPSIS... Low pressure southeast of New England will continue to generate periods of rain today along with brisk northeast winds and cool temperatures. Some improvement Sunday as winds slacken and rain becomes more spotty along with periods of dry weather. A new risk of showers are possible Monday followed by a stretch of dry weather Tue thru Thu along with seasonably cool temperatures. Still watching Hurricane Matthew, but lots of uncertainty whether it affects New England or not. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Radar continues to show bands of showers moving north across Southern New England. Lift is rather weak, and mainly the result of a low pressure passing by to our south. As this low pressure moves offshore, we should start to start to get into a dry slot later today. Looking very much like a low QPF/high PoP kind of forecast. Most rainfall rates were less then one tenth inch per hour. Will continue categorical PoPs through this morning, before slowly diminishing them this afternoon. In any case, not expecting a total washout. A large high pressure over the Maritimes will maintain persistent northeast winds. Besides keeping southern New England below normal temperature-wise, this will also keep the low level humidity higher, particularly across RI and southeast MA. Max temperatures today are not expected to be more than 10 degrees higher than the low temperatures this morning. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... Our region will still be in range of a potent mid-level cutoff low late tonight into Sunday. This should be close enough to maintain meager convective instability across our region. Despite a period of lower precipitable water values, there should still be enough moisture around for at least a continued chance of showers. Temperatures still below normal thanks to flow off the Gulf of Maine and continued cloud cover. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... Update 4 am ... Highlights ... * Risk of showers Sun night and Monday * Dry weather returns Tue thru Thu w/seasonably cool temps Overview ... Dry slot over the region Sunday evening with low level moisture trapped beneath may result to spotty light rain/drizzle. Deeper moisture and lift arrive Monday as closed low currently over the Ohio Valley moves across New England. This will result in a risk for scattered showers and isolated thunder given cold pool aloft yielding steep mid level lapse rates. Then all model guidance agrees on mid level trough moving offshore with rising heights over New England Tue thru Thu. However this yields a 1035 mb surface high over the Gulf of ME. So theme will be mainly dry weather Tue thru Thu but accompanied by a cool maritime airmass. Then by late next week still lots of uncertainty on the track of Hurricane Matthew. Details ... Sunday night ... dry slot still over the region especially during the evening hours. Model time sections reveal lots of low level moisture trapped beneath the dry air aloft so spotty light rain/drizzle possible. So damp and cool however with pgrad relaxing not expecting too much wind which will help take the edge off the cool/damp conditions. Monday ... Some breaks of sunshine possible however this will only increase the risk of afternoon showers as closed low currently over the OH Valley moves across southern New England. This combined with cold pool aloft will yield steep mid level lapse rates and result in a risk of thunder. Not as cool as previous days given some breaks of sunshine along with winds off the ocean easing. Highs 65 to 70 likely. Tue thru Thu ... building heights across New England supports dry weather. However this setup also yields 1035 mb high settling over the Gulf of ME resulting cool/brisk weather across Cape Cod and the Islands with ENE winds gusting up to 25-30 mph. Also model time sections reveal lots of strato-cu possible in this moist ENE flow across Cape Cod and Islands. Thus more sunshine inland. Highs slightly cooler than normal with afternoon temps in the low to mid 60s. Friday ... still large spread of solutions regarding hurricane Matthew. Models in better agreement this morning on latitude of Matthew late next week...however models differ significantly on longitude position. For example At 144 hrs/00z Fri 00z GFS has Matthew along the east coast of FL...with 00z UKMET over the Bahamas and 00z EC east of the Bahamas. The 00z GEFS indicates the 00z GFS is on the western edge of all GEFS solutions. The 00z EPS wasn`t available as of this writing but its 12z run was farther southeast with most of its 51 members remaining well southeast and offshore of New England. At this time range all possible outcomes remain in play given large range of solutions and time range. However the bulk of the guidance supports on offshore system as of now. Stay tuned. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Sunday/... Today...Moderate confidence. Low-end MVFR or IFR cigs linger through the day with on-and-off rain showers lowering vsbys. Tonight...Moderate confidence. May see some minimal improvement during the overnight hours. However, low CIGS will remain an issue. At least MVFR for most of southern New England, with IFR CIGS toward the south coast. Sunday...Moderate confidence. MVFR/IFR cigs and vsbys in showers and fog. Diminishing northeast flow. KBOS TAF...High confidence in trends, moderate confidence in timing. KBDL TAF...High confidence in trends, moderate confidence in timing. Outlook /Sunday Night through Wednesday/... Sunday night ... Moderate confidence. MVFR/IFR cigs and vsbys in spotty light rain/drizzle and fog. Diminishing northeast flow. Monday-Tuesday... moderate confidence. VFR with areas of MVFR across Cape Cod and Islands. Wednesday...Moderate confidence. VFR. && .MARINE... Forecaster Confidence Levels. Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Sunday/... High confidence. It will likely take until into Sunday for seas to drop below 5 ft across the eastern, outer coastal waters. With northeast winds gradually diminishing today and tonight, expecting seas to subside as well. Small Craft Advisories will continue for at least a while today. Will likely be able to convert the remaining Gale Warnings to Small Craft Advisories later this morning. Still evaluating the trends. Outlook /Sunday Night through Wednesday/... Diminishing Northeast wind Sunday night and Monday with gusts 20 knots or less. Northeast winds increase again Tuesday and Wednesday on the Southern and Southeast waters with frequent gusts 20-25 knots. Seas 5-6 feet on the eastern waters. Seas build again Tuesday and Wednesday with 5-7 foot seas on the outer waters. Small Craft Advisory will be needed for much of this time period. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 5 PM EDT this afternoon for ANZ232. Small Craft Advisory until noon EDT today for ANZ233-234. Small Craft Advisory until 8 PM EDT this evening for ANZ230- 231-235-237. Small Craft Advisory until 10 PM EDT Sunday for ANZ250-254. Small Craft Advisory until 1 PM EDT Sunday for ANZ251. Small Craft Advisory until 8 AM EDT Sunday for ANZ255. Small Craft Advisory until 1 AM EDT Sunday for ANZ256. && $$ SYNOPSIS...Belk/Nocera NEAR TERM...Belk SHORT TERM...Belk LONG TERM...Nocera AVIATION...Belk/Nocera MARINE...Belk/Nocera

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