Lexington, Massachusetts, USA
000 FXUS61 KBOX 291105 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 705 AM EDT Tue Oct 29 2024 .SYNOPSIS... Looking at a period of below normal temperatures this morning. A warm front today will bring increasing clouds and light rainfall to the region. Warming up for Wednesday then near record warmth Thursday before a cold front will bring temperatures back into the 50s for the weekend. Light rain showers are possible Friday with dry and sunny conditions returning for the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... The core of surface high pressure shifts east of the region today and winds will turn southerly as a warm front begins to make its way north across southern New England. The biggest impact of this front today will be an increase in cloudcover starting early, then rain chances overspreading the region from west to east in the afternoon (western MA/CT) and late evening (eastern MA). Along with forcing for ascent from the warm advection, a 30-35 kt LLJ develops overhead; these together will act on a 1.25+ inch PWAT plume leading to widespread light rain showers as we go into the overnight hours. The warm advection will also lead to slightly warmer temperatures today compared with yesterday, in the upper 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Tonight rain showers continue, exiting western areas before sunrise but may linger into the early morning hours for extreme eastern MA. Rainfall amounts are not expected to be significant in the face of our abnormally dry stretch, especially for areas further south. The highest rainfall amounts (some guidance suggesting as much as a quarter inch or more) is more likely in northern MA in closer proximity to better forcing. Ensemble guidance indicates a 90%+ chance of at least a tenth of an inch of rain in northern MA while southern MA and RI is at a 40-50% chance. Winds will be breezy overnight, especially over the waters as that LLJ passes overhead. Wednesday a few showers linger in the morning but as mid level ridging builds back in so does drier air. W/SW winds will advect in a much warmer airmass with 850 mb temps climbing from +1C on Tuesday to +14C on Wednesday! This translates to a much above average day, with highs in the mid 70s. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Key Points * Well above normal to record high warmth Thursday * Elevated fire weather concerns continue with abnormally dry conditions * Cold front could bring light showers Friday with much colder temperatures by Saturday Thursday Despite the flattening upper level ridge on Thursday, 850mb temps rise to +12C to +13C on with strong WSW winds. With mostly sunny skies in place, High temperatures across the region will sore to near record high values in the upper 70s to low 80s. Not out of the question that typical warm spots like Bradley and Norwood reach the mid 80s. With SSW winds, Thursday could even feature closer to summer like dewpoints in the upper 50s to low 60s. However, I think guidance may be a bit bullish on dewpoints as mixing will help bring more dry air down then current global guidance is indicating. BUFKIT soundings show dewpoints dropping from 50F at 925mb to 32F around 900mb. If temps are able to top 80F, mixing above 900mb becomes more likely, pulling down very dry air from aloft. Winds above 900mb look to be near 40mph, but its unlikely to see gusts that high mix down the surface. Winds in the middle of the boundary layer are closer to 20mph which is more likely to be observed at the surface. With the continued abnormally dry conditions, expect elevated fire weather conditions to continue on Thursday. Friday A cold front and trailing shortwave crosses the region Friday which could bring some scattered showers to the region. Moisutre looks limited again with the cold frontal passage and a soaking rain is looking is unlikely. Some of the global deterministic guidance even pitch a shut out for all of SNE. Any rain that does fall will likely be light under a tenth of an inch. Temps do moderate into the low to mid 70s with the passage of the first cold front. Winds turn west behind the front and remain gusty at 20-30mph. Depending on how the precip forecast evolves through the week, elevated fire weather conditions would persist with a drier forecast. Saturday and Sunday. A secondary cold front and reinforcing shot of cold air bring temps back down into the 50s. Upper level ridge and surface high pressure build back in, bringing dry conditions and mostly sunny skies. Winds quickly die down and become light northerly on Saturday, flipping to light SSW again on Sunday. Early next week: Forecast confidence breaks down significantly by Monday with large phase differences in the global deterministic guidance. The general trend however looks to be near normal temperatures and possibly more chances at some beneficial rainfall. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... Forecast Confidence Levels: Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 12Z update... Today...High Confidence. VFR/MVFR to start, lowering to MVFR during the late afternoon and evening ahead of an approaching warm front. South/southeast winds 7 to 10 knots. Tonight...Moderate Confidence. MVFR to IFR. -SHRA moves in from west to east after 00z in western areas, while the eastern coast 03z. South winds around 10 knots, may have gusts near 20 knots along the coast. Wednesday...High Confidence. VFR. Breezy SW winds. SHRA chances early morning on east coast terminals before exiting east. KBOS TAF...High Confidence in TAF. KBDL TAF...High Confidence in TAF. Outlook / Wednesday Night through Friday/ Wednesday Night through Thursday: VFR. Breezy. Thursday Night through Friday: VFR. Breezy. Chance SHRA. Friday Night through Saturday: VFR. Breezy. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Through Tuesday...High confidence. Today: High pressure then remains over the waters with winds less than 25 kts and waves 2-4 ft. Tonight: Small Craft conditions develop tonight in the outer waters. Winds increase with gusts 20-30 kts and waves 4-6 ft. Wednesday: Small craft conditions come to an end through the day. SW winds 15-20 kt. Outlook /Wednesday Night through Saturday/... Wednesday Night through Thursday: Winds less than 25 kt. Areas of seas approaching 5 ft. Thursday Night: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Slight chance of rain showers. Friday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain showers. Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Slight chance of rain showers. Saturday: Winds less than 25 kt. Local rough seas. && .FIRE WEATHER... * SPS for Elevated Fire Weather Concerns Continues Today State Fire Weather Partners requested the continuation of a Special Weather Statement for elevated fire weather concerns today. There are numerous active brush fires are burning across southern New England. Cooler temperatures continue for today with highs in the 50s to near 60F in the lower Connecticut River Valley. Dewpoints increased slightly, raising the minimum values of relative humidity between 45 percent and 65 percent for this afternoon. Wind direction are south/southeast 10 to 15 mph with gusts 20 to 25 mph. && .CLIMATE... Maximum Record High Temperatures: October, 30th BOS: 78F (1918) ORH: 78F (1946) PVD: 79F (1946) BDL: 83F (1946) Maximum Record High Temperatures: October, 31st BOS: 81F (1946) ORH: 79F (1946) PVD: 83F (1946) BDL: 82F (1946) && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 8 PM this evening to 8 AM EDT Wednesday for ANZ235-237. Small Craft Advisory from midnight tonight to 5 PM EDT Wednesday for ANZ250-254. Small Craft Advisory from 8 PM this evening to 2 PM EDT Wednesday for ANZ255-256. && $$ SYNOPSIS...BW/KP NEAR TERM...BW SHORT TERM...BW LONG TERM...KP AVIATION...BW/KP MARINE...BW/KP FIRE WEATHER...BW/KP CLIMATE...Dooley
Meta data:
ID: dd899ac3-3c05-40b1-aa4a-9ed59c08703e
Link:
https://api.weather.gov/products/dd899ac3-3c05-40b1-aa4a-9ed59c08703e
Index:
https://api.weather.gov/products/types/AFD/locations/BOX