Content-Length: 11364 | pFad | http://tgftp.nws.noaa.gov/data/raw/fx/fxus61.kbox.afd.box.txt
FXUS61 KBOX 200509 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 109 AM EDT Fri Sep 20 2024 .SYNOPSIS... Rain continues for the Cape and Islands through tonight into tomorrow, with chances to the northwest decreasing going into the weekend. Gusty northeast winds will keep temperatures near or below normal for much of the region tomorrow into the weekend. Next chance of rain comes around mid week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 730pm update... made a few minor adjustments to the PoP, weather and wind aspect of the forecast for tonight based on current trends and most recent hi-res model data. Models are struggling with the overall coverage of the precip, and although they were indicating there would be some local maximum of rainfall somewhere near the Cape, they didn't get the location. Radar estimates of 2 to 3+" of rain has fallen since noon, but the axis was over the water just south of the Cape and north of the Islands. Still about 1.5" has fallen at MVY and ACK. No flood concerns however given that it's fallen over a relatively long period of time. Mesonet obs have indicated some gusts of 40-45mph across the Cape and Islands. Did increase the wind forecast a little based on those obs. Model soundings show the gusty winds will continue overnight, and although a rogue gust to 50 mph can't be ruled out, it's not enough to rate the need for any sort of wind advisory. Of course over the water, the winds are more impactful, thus the Gale Warnings we have. Meanwhile once you get west of about I-95, not much is going on. Should be enough clear skies out west that some patchy fog is possible in the CT River Valley, especially in sheltered areas, late tonight. Previous Discussion... A stalled low looks to remain off the coast of southern New England due to a blocking high to the north. Unsettled weather will continue for the Cape and Islands through Friday morning. Cloudy conditions expected to continue through tonight for the rest of eastern MA and RI into parts of central MA, but clearer conditions out to the west. Temperatures tonight expected to be primarily in the lower 60s and upper 50s. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/... Tomorrow and Tomorrow Night The stalled low looks to stick around through the weekend, continuing the trend of cloudy skies and chances for rain for eastern MA. Pressure gradient between the blocking high and the low in question will encourage NE gusts up to 35 mph (30 knots) down to the Cape and Islands, reaching up to 25 mph near Boston. Highs tomorrow look to remain in the 60s for much of eastern MA into RI with persistent cloud cover and showers throughout the day, but confidence in consistent showers northwest of the Cape remains a bit low. Highs in the CT River Valley are currently expected to be in the mid 70s. However, considering today's highs ended up a bit higher than forecast, it could reach the upper 70s to lower 80s. This will depend on cloud cover, which is a bit uncertain at this time. Chances for showers continue Friday night going into Saturday morning and strong NE flow is expected to continue. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Key Points: * Some rain and breezy conditions Saturday * Dry to start next week, becoming unsettled mid-week No huge changes with the 12z suite of model guidance with respect the long term forecast period, though we have more consistency with the evolution of the slow moving coastal low Saturday and Sunday which gives increasing confidence for this part of the forecast. The low center Saturday morning will be just southeast of the 40n/70w benchmark and be slowly drifting south. Models all show deep moisture across the eastern half of southern New England, so that is the area with the highest chance of rainfall. The PoP gradient might need to be tightened up in later forecasts as it could end up being totally dry across northern CT and the Worcester area westward. Certainly a damp and breezy day close to the east coast with NE winds gusting over 30 mph at times. Kept with the model blend for QPF, so perhaps another 1/4 to 1/2" of rain during the day. Low pressure moves further away Saturday night and Sunday morning, we will see improving conditions from northwest to southeast. Still have some lingering PoPs (30% or so) for far SE MA, Cape and Islands for Sunday morning. That could end up being pessimistic. Some question as to how long low level moisture hangs around across southeastern sections, so that area might end up staying cloudy most of the day. Further inland looks to feature a good amount of sun. High confidence that a ridge of high pressure will re-establish dominance in our weather for the second half of Sunday into Tuesday. Beyond that, confidence starts to decrease again as an upper trough tries to move in from the west. How quickly that trough can break down the ridge is still up for grabs in the models, given some significant differences between models and model runs with regard to the amplitude and timing of that trough. For now stuck with NBM guidance and have 30-40% PoPs from late Wednesday through Thursday. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06Z TAF update Through 12Z. MVFR borderline IFR ceilings with steady northeast winds around 10 knots through 12Z. -SHRA at Cape Islands terminals with some shower activity spreading to BOS, PVD, and BED by 12Z. Today...High Confidence MVFR borderline IFR conditions persist at the same terminals through tonight as area of low-pressure supporting northeast winds and lower ceilings remains somewhat stationary. Wind gusts will inrease this afternoon with 40+ knot gusts possible at Nantucket and 30 to 35 knot gusts possible over The Cape. Wind gusts should be more modest at the remaining terminals in the 20 to 25 knot range. Gusts at Nantucket peak around 18Z before gradually falling to the 30 to 35 knot range by 00Z tonight. Expect continued shower activity over The Cape/Islands with some stray showers possible at the eastern terminals. BDL,BAF,ORH should stay dry today. Tonight...High confidence in flight categories, lower confidence in precipitation potential Little change to flight categories overnight with more IFR/MVFR ceilings and -SHRA over The Cape/Islands. Northeast winds remain somewhat elevated from 10 to 20 knots with gusts from 20 to 30 knots. Strongest winds over The Cape/Islands. Tomorrow Interior terminals trend to VFR ceilings by 18Z. Lower ceilings linger at BOS,PVD, and Cape/Island Terminals (MVFR/IFR ~ 1000 feet) with slow improvements by 00Z tomorrow evening. BOS TAF...High Confidence Teetering between MVFR/IFR for much of the next 36 hours. Steady northeast winds with gusts from 20 to 25 knots. Should see improvements to VFR by Saturday afternoon/evening. BDL TAF... High Confidence Outlook /Saturday Night through Tuesday/... Saturday: Mainly VFR, with local IFR possible. Windy with gusts up to 30 kt. Chance SHRA. Saturday Night: Mainly VFR, with local MVFR possible. Breezy. Chance SHRA. Sunday: Mainly VFR, with local MVFR possible. Windy with local gusts up to 30 kt. Slight chance SHRA. Sunday Night through Monday: VFR. Breezy. Monday Night: Mainly VFR, with local MVFR possible. Breezy. Tuesday: Mainly VFR, with areas MVFR possible. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight through Friday Night Dangerous Marine conditions over the next 24 to 48 hours as an area of low pressure stalls south of the coastal waters. Confidence has increased enough to issue Gale Warnings for the southern offshore zones and Nantucket Sound. Wind gusts in excess of 35-40knots are likely overnight, lasting into Saturday evening. Gales may need to be expanded further north into Cape Cod Bay and the Northern off shore zone, but confidence was not high enough to include in this update. As for the rest of the near shore waters, winds will still be gusting 25-35 knots through Saturday night including Narragansett Bay and Boston Harbor. Seas will continue to build overnight to 8-12 feet in the open waters. High surf will cause dangerous conditions near the coasts as well with large breaking waves and strong rip currents. Mariners and swimmers should take extreme caution if venturing out to beaches or jetties tomorrow. Outlook /Saturday Night through Tuesday/... Saturday: Strong winds with gusts up to 30 kt. Rough seas up to 14 ft. Rain showers likely. Saturday Night: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 11 ft. Chance of rain showers. Sunday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 11 ft. Chance of rain showers. Sunday Night: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 11 ft. Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 11 ft. Monday Night: Winds less than 25 kt. Rough seas up to 9 ft. Tuesday: Winds less than 25 kt. Areas of rough seas. && .TIDES/COASTAL FLOODING... The persistent northeast winds will produce a surge of roughly 1.5 to 2 feet from late tonight into Saturday based upon guidance from the Stevens Institute and P-ETSS. Given the monthly high astronomical high tides, the combination means we will be reaching minor flood level along the east coast of Massachusetts over several high tide cycles. Right now it looks like the highest water levels will be experienced with the Friday afternoon high tide, and our current forecast has water levels topping out just a few inches below moderate flood stage. With the extended period of northeast winds, this will also build up rough seas and rather significant wave heights over 10 feet offshore. The combination of that wave energy could be enough to result in impacts that would normally be associated with higher water levels. That would especially be the case for those coastal locations (like Plum Island) that are very susceptible to high water levels. We have issued a Coastal Flood Watch for the Friday high tide. We will be fine tuning the forecast overnight and convert that watch to either a Coastal Flood Advisory or Coastal Flood Warning (if we expect more significant impacts). && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...High Surf Advisory from 7 AM this morning to 7 PM EDT this evening for MAZ007-019-022-024. Coastal Flood Watch from 11 AM EDT this morning through this afternoon for MAZ007-015-016-019-022>024. High Risk for Rip Currents through this evening for MAZ023. RI...High Risk for Rip Currents through this evening for RIZ006>008. MARINE...Small Craft Advisory until 8 AM EDT Saturday for ANZ230-236. Small Craft Advisory until 8 AM EDT Saturday for ANZ231- 233>235-237-250-251. Gale Warning until 8 PM EDT this evening for ANZ232-254>256. && $$ SYNOPSIS...Hrencecin NEAR TERM...Hrencecin/Nash SHORT TERM...Hrencecin LONG TERM...Nash AVIATION...RM MARINE...Hrencecin/KP TIDES/COASTAL FLOODING...Nash/NoceraFetched URL: http://tgftp.nws.noaa.gov/data/raw/fx/fxus61.kbox.afd.box.txt
Alternative Proxies: