Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 190928 AFDBOX Area Forecast Discussion National Weather Service Taunton MA 428 AM EST Sun Feb 19 2017 .SYNOPSIS... Unseasonably mild temperatures today will be followed by a brief cool down tonight into Tuesday, as a dry cold front crosses the region. Milder weather returns the middle of next week. However, another pair of fronts may be accompanied by some precipitation sometime Tuesday night into Wednesday. At this point, Thursday has potential to be the warmest day of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... ***Unseasonably mild temperatures today with highs well up into the 50s to around 60*** A cold front will cross the region today, but with a very dry atmosphere no precipitation will occur. This is also a classic setup for high temperatures to exceed guidance numbers by several degrees. This a result of a very mild start in many locations coupled with west northwest flow and cold air lagging well behind the front. With that said, we think much of the region will see highs in the middle to upper 50s to around 60 across portions of RI/SE MA. Should see a fair amount of sunshine through early afternoon, but model cross sections indicate some lower clouds will drop down from the north by mid to late afternoon as low level moisture increases. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... Tonight... Strong shortwave across eastern Canada dives southeast with developing closed mid level low sliding south of the Canadian Maritimes. This allows a dry but much colder northwest flow of air into southern New England. Low temps will bottom out in the upper 20s to the lower 30s by daybreak Monday. Monday... Partly sunny with a brief return to seasonably cool temps. 850T between -8c and -10c should hold high temps mainly in the upper 30s to lower 40s. Bufkit soundings also indicate it will be a bit breezy with northwest wind gusts of 20 to 25 mph expected. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Highlights... * Seasonably cool Tuesday * Light rain/pockets of freezing rain possible Tuesday night into Wednesday * Thursday looks to be our warmest day * More widespread rain possible Friday night into Saturday Overview and model preferences... General consensus is for amplified flow over the eastern half of the USA to become more zonal toward mid week. Once this happens, not expecting to see major temperature swings. In fact, expecting trend of above normal temperatures to continue. Still plenty of detail differences with timing of certain features, which is not uncommon in nearly zonal flow scenarios. While minor at first, these differences significantly grow with time. Have low confidence in the details, after Friday. Preferred a consensus approach to smooth over the less predictable details, especially late this week. Details... Monday Night into Tuesday...Still quiet, with high pressure overhead. Low risk for rain to arrive across western portions of southern New England late in the day. Near normal temperatures. Tuesday night into Wednesday... Guidance converging on the idea of a brief period of rain, but differ in their timing. GFS is fastest by about 6 hours. Most likely window for precipitation looks to be Tuesday evening into Wednesday morning. With this timing, cannot completely rule out the possibility of some sleet or freezing rain. These details will need to be resolved over the next day or so. A weak front should move back north, allowing temperatures to rise above freezing, ending the threat of mixed precipitation. Thursday into Friday morning... A clipper-like low pressure should move through the Great Lakes. Persistent southwest winds should lead to above normal temperatures once more. Not a lot of moisture to the southeast of this system, so thinking dry weather should prevail across much of our region. It`s possible, if southwest winds become strong enough, for Thursday to be the warmest day of this week. Will need to see how much snow melts between now and then. The more snow which melts, the more likely we could see a few locations approach 60 degrees. Friday afternoon into Saturday... Huge solution spread in the ensembles and deterministic guidance. Have little confidence in the details, although there is general agreement for a low pressure to move northeast near the Great Lakes. Thus, expecting any precipitation would be rain. Some signs this system could be energetic enough where some thunderstorms would be a possibility. && .AVIATION /08Z SUNDAY THROUGH THURSDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Today...Moderate to high confidence. Mainly VFR conditions but some MVFR CIGS may develop by late afternoon north of the MA turnpike. Tonight and Monday...Moderate to high confidence. VFR conditions probably dominate, but some MVFR CIGS possible tonight into Monday morning with the highest risk across the interior and outer Cape. Northwest wind gusts of 20 to 25 knots expected during the daylight hours Monday. KBOS TAF...High confidence in TAF. KBDL TAF...High confidence in TAF. Outlook /Monday Night through Thursday/...Moderate confidence. Monday through Tuesday... Monday Night through Tuesday morning... Generally VFR. Winds diminish as a high pressure moves overhead. Tuesday afternoon through Wednesday... A weak cold front approaches our region, with southwest winds out ahead of it. This front is likely not to make it completely through southern New England. CIGs and Vsbys lower to MVFR in showers, then improve to VFR after the front passes a location. Thursday... Weak front returns north as a warm front, but not a lot of moisture to work with. VFR conditions expected. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Monday/...High confidence. Today...High confidence. Cold front crosses the region today, but cold advection lags well behind front. Therefore, expect winds and seas to generally remain below small craft advisory thresholds. Tonight and Monday...High confidence. Cold advection develops tonight into Monday behind the front and expect northwest wind gusts of 25 knots over most waters. Have hoisted small craft headlines for all open waters. Outlook /Monday Night through Thursday/... Monday Night and Tue...High confidence. Rough seas and winds diminish. Tuesday night into Wednesday...Moderate confidence. Relatively tranquil boating conditions. Scattered rain may lead to reduced visibility at times. Thursday...Moderate confidence. Relatively tranquil boating conditions continue. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 10 PM this evening to 7 PM EST Monday for ANZ231-232-254>256. Small Craft Advisory from midnight tonight to 7 PM EST Monday for ANZ233>235-237. Small Craft Advisory from 5 PM this afternoon to 7 PM EST Monday for ANZ250-251. && $$ SYNOPSIS...Belk/Frank NEAR TERM...Frank SHORT TERM...Frank LONG TERM...Belk AVIATION...Belk/Frank MARINE...Belk/Frank is the U.S. government's official web portal to all federal, state and local government web resources and services.