120 FXUS61 KBOX 260752 AFDBOX Area Forecast Discussion National Weather Service Boston/Norton MA 352 AM EDT Thu Mar 26 2020 .SYNOPSIS... Dry and quiet weather across southern New England today as high pressure builds in. Another low will approach the region from late tonight into Friday. This will bring the low risk for a few brief showers to areas south of the Massachusetts Turnpike on Friday, but dry weather will dominate. A ridge of high pressure will bring dry and pleasant weather to the region Friday night into Saturday. Low pressure approaching from the Great Lakes will bring some rain late Saturday night and especially Sunday along with chilly temperatures. Scattered showers linger on Monday before dry and seasonable weather returns Tuesday. A potential coastal storm may bring some rain or perhaps even some wet snow later Wednesday and/or Thursday, but that remains uncertain. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... A ridge axis will be located over New England today, the ridge axis will gradually build just offshore by this evening. The surface high will build into the Carolinas and slide offshore. The high will nudge into southern New England from the south. A shortwave trough will lift from the Upper Mississippi River Valley early today into Quebec by this evening. A surface low will deepen as it moves into Quebec. Good agreement amongst deterministic guidance at this point in time. Expect dry and quiet weather throughout southern New England. Warmer air will begin advecting in as flow aloft becomes southwesterly once the ridge axis moves just east of the region. Cloud cover will increase from west to east as the low moves into Quebec. Do expect it to be breezy across Cape Cod and the Islands due to the tightened pressure gradient from the departing low. Gusts will lessen as high pressure relaxes the pressure gradient. High temperatures will be in the upper 40s and low 50s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Highlights * Chances of rain along the south coast late tonight into early Friday afternoon. Some uncertainty on the track of this system, and it could remain far enough to the south to keep the region precipitation free. The ridge axis will continue building offshore Thursday night into Friday, while the shortwave trough over Quebec lifts into northern New England. The low associated with the shortwave will lift into Quebec/New Brunswick. The cold front associated with the low will stall out across the Mid Atlantic/Ohio River Valley. Another shortwave will lift in from the Mid Mississippi River Valley. This may interact with the boundary to develop a low that slides just south of the region on Friday. Still some discrepancy with the intensity of the developing system with the GFS still being the most robust. The majority of guidance keeps the system well to the south, but have nudged things to blend in a bit of the GFS just in case the system jogs a bit further north. Regardless, expecting the precipitation to be light. The best opportunity for any rain is across the south coast. Low temperatures tonight will fall into the 30s across the region. Temperatures on Friday will rebound into the low to mid 50s regionwide. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Highlights... * Dry and pleasant Fri night into most of Sat * Periods of rain and chilly late Sat night & especially Sun * Scattered showers persist Mon * Dry and seasonable Tue * Rain or perhaps even some wet snow possible later Wed into Thu "if" a coastal storm impacts the region Details... Friday night and Saturday... A ridge of high pressure will result in dry/pleasant weather Fri night into Sat. Mainly clear skies/light winds Fri night should allow overnight lows to range from the upper 20s to the middle 30s in most locations. A pleasant day Sat despite the increase in mid/high level cloudiness from the west during the afternoon. The ridge of high pressure should keep us dry with highs well up into the 50s in most locations. Saturday night and Sunday... Low pressure will be lifting into the Great Lakes Sat night. This will increase the forcing for ascent and allow some rain to overspread the region late Saturday night, especially across the interior. The steadiest/heaviest rain will be across northern New England, where better forcing/low level jet intersect a surface warm front. A secondary low will develop near the southeast New England coast by Sunday. This will allow moist low level easterly flow with as southeast low level jet above it. This will result a rainy Sunday with raw conditions as temperatures will generally remain in the 40s. Monday... Despite the surface low moving east of the region, upper level trough/cold pool aloft will cross the region. This will result in scattered showers and we can not even rule out some graupel with the marginal instability/cold air aloft. Highs mainly in the upper 40s to the lower 50s. Tuesday through Thursday... Dry and seasonable weather is expected Tuesday. We will then need to watch the potential for coastal storm sometime later Wed into Thu. Remains to be seen if it will develop, as the GFS keeps us dry with a much weaker wave of low pressure passing well to our south. However, the ECMWF/GGEM develop a rather potent closed upper level low to our southwest and a surface low intensifying near the coast. Pattern recognition tells us if this happens the potential for a cold windswept rain or even some early April wet snow would be possible later Wed into Thu. Plenty of uncertainty, but will have to watch this especially if an upper level closed low passes near or south of our region. && .AVIATION /08Z THURSDAY THROUGH MONDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. 06Z Discussion... Tonight...High confidence A coastal storm will continue lifting offshore tonight and high pressure will build in behind it. Expect VFR conditions at all terminals except for Cape Cod and the Islands where MVFR ceilings will persist. ACK will see rain taper off as the low lifts offshore. Due to the tight pressure gradient expect gusty northeast winds across Cape Cod and the Islands. May see conditions improve to VFR across Cape Cod by daybreak. Thursday...High confidence Will see VFR conditions throughout the day. Most locations will see light northerly winds gradually becoming southerly/southwesterly during the afternoon. Gusty winds persist across Cape Cod and the Islands. Thursday night...Moderate confidence. Mainly VFR conditions, but clouds will increase from west to east as low pressure moves into the Mid Atlantic. Think the best opportunity for any precipitation is south of the Mass Pike. This is also where reduction to MVFR is possible as ceilings lower. Moderate confidence as many pieces of deterministic guidance keep the system too far south to impact southern New England. Not out of the question that conditions remain VFR without any precipitation. KBOS Terminal...High confidence in TAF. KBDL Terminal...High confidence in TAF. Outlook /Friday Night through Monday/... Friday Night through Saturday: VFR. Saturday Night: Mainly MVFR, with local IFR possible. Breezy. Chance RA. Sunday: Mainly MVFR, with areas IFR possible. Breezy. RA. Sunday Night through Monday: Mainly MVFR, with local IFR possible. Chance SHRA. && .MARINE... A coastal storm will continue lifting to the east and northeast of region today. Northeasterly winds will gradually become northerly as the low moves well offshore. Will remain gusty through this morning, but expect wind speeds and gusts to lessen during the afternoon as high pressure builds in. Expect speeds of 15 to 25 kts with gusts of 20 to 30 kts this morning. Speeds lessen to 10 to 15 kts this afternoon with gusts decreasing to 15 to 25 kts. Despite the decreased winds expect seas to remain heightened through much of Friday. Extended the Small Craft Advisory into Friday for the majority of the waters. Chances of precipitation across the southern waters late tonight into early Friday as low pressure slides through. Winds will shift to the southwest and west tonight. Outlook /Friday Night through Monday/... Friday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Saturday: Winds less than 25 kt. Seas locally approaching 5 ft. Saturday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain. Sunday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Rain. Sunday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 7 ft. Rain showers. Monday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory until 4 PM EDT this afternoon for ANZ231- 232. Small Craft Advisory until 1 PM EDT this afternoon for ANZ233- 234. Small Craft Advisory until noon EDT Friday for ANZ235-237. Small Craft Advisory until 11 PM EDT Friday for ANZ250-251-254. Small Craft Advisory until 2 PM EDT Friday for ANZ255-256. && $$ SYNOPSIS...BL/Frank NEAR TERM...BL SHORT TERM...BL LONG TERM...Frank AVIATION...BL/Frank MARINE...BL/Frank