045 FXUS61 KBOX 101549 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 1149 AM EDT Sun Mar 10 2024 .SYNOPSIS... Minor tidal flooding likely this morning into early afternoon along MA coastline. Chance for rain/snow showers today with seasonably mild temperatures. A brief cooldown to start the work week before temps warm to above normal Thursday. Mainly dry conditions expected for the first half of the work week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1120 AM Update: Period of downpours and strong S/SE winds associated with a 990 mb low now over the southern Gulf of Maine has since ended. Wind Advisories for eastern MA and RI in association with the period of strong southeast winds have since been allowed to expire. Still are dealing with low clouds and fog over southeast MA and the Cape and Islands, but a deepening mixed layer owing to increasing cold advection should allow for fog and low clouds to gradually scour out over the next couple hours. Rivers/Coastal Flooding: River flood warnings continue on several rivers in CT, MA and RI. See recent river flood warnings for more details. Most recent update from NERFC calls for the reach Wood River at Hope Valley and the reach of the Pawtuxet River at Cranston to barely reach into the Moderate flood stage category early tonight. The prior river flood warning for the reach of the Sudbury River at Saxonville has been cancelled early with the river having crested below bankfull and with slow receding trends expected. On the tidal flooding front, tidal gages along the RI/MA South Coast have begun to recede, having now passed the morning high tide. We may be able to cancel a portion of the existing coastal flood advisory for those areas shortly. The focus for minor coastal flooding then however shifts to the eastern MA coast, however peak of the winds/surge has likely already taken place and shifted into coastal NH/ME. Will keep the coastal flood advisory going for the eastern MA coast. So what about the rest of the day? Other than over the Cape and Islands as mentioned above, cloud cover continues to scatter out to more of a partial to mostly cloudy look, with peeks of sun to varying degrees. Modest W/WNW breezes to around 25 mph are possible in this post-frontal partial clearing period. I'd imagine sky and wind gust conditions probably take on a similar look for most of the day; until we see a bit more of an increase in cloud cover later this aftn and tonight as approaching upper low from the Gt Lakes moves in. That may bring some isolated to scattered showers into CT and southern RI late this aftn but no washouts. Previous discussion: Low pressure continues to lift into northern New England this morning with moderate to heavy rain departing with the low. In fact, rain has come to an end across western CT/MA as of this writing at 3AM, which is slightly ahead of schedule compared to overnight hi- resolution guidance. Given how progressive this system has proven to be, anticipating we are still on track for rain arc north and east by 12Z this morning, with a few lingering showers possible for the Cape and Islands until ~14Z. Flood watches will be canceled accordingly as rain shield moves out of the region this morning. Trough/500mb low sweeps in behind departing precip maker this morning. It will take some time for 925mb temps to cool, however, with temps near 4C this afternoon across eastern MA and around 0C for the high terrain. Thus it will be a seasonably mild day with temperatures ranging from the mid 40s to mid 50s, the exception being the high terrain of the Berkshires which will have a hard time eclipsing the 40F mark. Overall, expecting a mix of sun and clouds to develop by afternoon with the clearest conditions furthest from the upper level low across eastern MA. There will be enough residual moisture in the column from the upper level low/trough to generate some upsloping snow this afternoon given strong westerly winds of ~30kt. Spotty shower activity is also possible outside of the Berkshires. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... Cold air aloft peaks overnight tonight and early Monday morning and with westerly flow, expecting pretty good mixing into the 925mb jet. With cold air mixing to the surface, it will be a chilly night across southern New England, with widespread lows in the upper 20s and low 30s. Some lingering rain and snow showers possible overnight as trough moves seaward by early Monday morning. 925mb winds make a comeback in a big way come Monday with the 925mb LLJ strengthening to between 40-50kt. Given aforementioned good mixing potential, there is high confidence in gusts exceeding 40kt for a prolonged period Monday into Monday evening across the high terrain. In fact, winds will be quite gusty region wide, with gusts in excess of 35kt possible for the entire CWA. Based on forecast confidence, issued a Wind Advisory for Central and Western MA as well as all of our CT Zones for Monday into Monday evening. Anticipating this advisory will be expanded east into RI and eastern MA as forecasters gain more confidence in wind gusts over the next 24 hours. With cold pool peaking aloft, it will be cold start to the work week with highs generally in the low 40s. Monday will yield another day of a mix of clouds and sun as PWATs gradually drop from ~0.4" to ~0.2". && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Key Points... * Dry and quiet weather much of next week. * Increasingly mild temperatures well into the 50s. * Next chance of rain comes at the end of the week. A stretch of quiet and dry weather continues through Thursday as the closed maritime low exits east, replaced by mid level ridging and a surface high pressure. This will allow Monday's strong winds to diminish (while remaining breezy) on Tuesday and becoming light by Wednesday. An increasingly mild airmass moves in beneath the ridge, with temperatures bumping up into the 50s Tue/Wed and the 60s by Thu. The quiet pattern then breaks down around Thursday night/Friday as a weak northern stream disturbance and surface low track across New England. Moisture and dynamics don't look too impressive so wouldn't expect any issues with excessive rain or flooding, but wet weather may return to the end week. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 15Z TAF Update: Today: High confidence in trends, moderate in timing. Improving conditions to a MVFR/VFR cloud bases look for most TAFs this afternoon. LIFR fog/stratus over the Cape and Islands will take longer to scatter out where SW winds continue, but anticipating around 18-20z that we should see conditions trend to more of an MVFR look. SW winds continue over the Cape and Islands around 15-20 kt with gusts to 30 kt, though a gradual windshift to WSW/W expected thru 20z. Elsewhere, mainly W to WNW winds around 10-15 kt with gusts 23-27 kt. Tonight and Tomorrow... High Confidence Continued strong westerly winds, gusting between 20-30kt tonight and as high as 45kt Monday, highest in the hills of central and western MA. Generally VFR with high terrain MVFR tonight and VFR on Monday with scattering cloud deck. KBOS TAF...Moderate Confidence. BKN MVFR bases trend to BKN VFR by this aftn and continuing into Mon. WSW winds becoming W, gusting to around 25 kt this aftn and tonight. A more marked increase in W/WNW gusts pre-dawn Mon into Mon aftn, with gusts 35-40kt. KBDL TAF...High confidence. BKN MVFR-VFR bases today, continuing into tonight. W/WNW winds around 10-12 kt with gusts 20-22 kt today and tonight. A more marked increase in W/WNW gusts pre-dawn Mon into Mon aftn, with gusts 30-40 kt. Outlook /Monday Night through Thursday/... Monday Night: VFR. Strong winds with gusts up to 45 kt. Tuesday: VFR. Strong winds with local gusts up to 40 kt. Tuesday Night: VFR. Breezy. Wednesday through Thursday: VFR. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Today... Gales will fall off this morning leading to solid SCA criteria with WSW winds 15-25 kt. With that said, a gale watch for Tonight/Monday trumped the SCA today. Sea state will be a bit unsettled but wave action will subside slightly from overnight waves. Tonight... West winds trending to WNW and increasing to near gale force by Monday morning. Dry weather and good vsby. Gale watch in place that will need to be converted to a warning once current gales subside. Monday... Gale force conditions persist into Monday with strong NNW winds, up to 40kt. Rough seas thanks to persistent flow. Outlook /Monday Night through Thursday/... Monday Night: gale force winds with gusts up to 40 kt. Rough seas up to 11 ft. Tuesday: Low risk for gale force winds with gusts up to 40 kt. Areas of rough seas. Tuesday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of seas approaching 5 ft. Wednesday through Thursday: Winds less than 25 kt. && .TIDES/COASTAL FLOODING... * The entire coastline of MA & RI is covered by a Coastal Flood Advisory for the Sunday morning and early afternoon high tide. The strongest winds, peak storm surge and max pressure falls will not coincide with high tide Sunday morning/early afternoon, so moderate coastal flooding is not expected. As for coastal erosion, not expecting significant erosion given the reasons listed above along with large wave development not expected due to the short duration of strong winds and the storm only impacting one tide cycle. Storm surge values of 1.5 to 2.5 ft are expected. Given high astronomical tides, this will be sufficient to produce minor inundation and erosion along the MA/RI coastline. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Wind Advisory from noon Monday to 1 AM EDT Tuesday for CTZ002>004. MA...Wind Advisory from noon Monday to 1 AM EDT Tuesday for MAZ003- 004-010>012-026. Wind Advisory from 8 AM Monday to 8 AM EDT Tuesday for MAZ002- 008-009. Coastal Flood Advisory until 4 PM EDT this afternoon for MAZ007-015-016. Coastal Flood Advisory until 2 PM EDT this afternoon for MAZ019>024. RI...Coastal Flood Advisory until 2 PM EDT this afternoon for RIZ002-004>008. MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ230>237-250-251-254>256. Gale Watch from late tonight through late Monday night for ANZ230-233>237. Gale Watch from late tonight through Tuesday morning for ANZ231-232-251. Gale Watch from Monday morning through Tuesday morning for ANZ250. Gale Watch from late tonight through Tuesday morning for ANZ254>256. && $$ SYNOPSIS...KS NEAR TERM...Loconto/BW/KS SHORT TERM...KS LONG TERM...BW AVIATION...Loconto/KS MARINE...Loconto/BW/KS TIDES/COASTAL FLOODING...BW