Montauk NY to Marthas Vineyard out 20 NM South of Block Island Marine Forecast
| This Afternoon...S Winds 10 To 15 Kt, Increasing To 15 To 20 Kt. Occasional Gusts Up To 25 Kt. Seas Around 3 Ft. A Chance Of Showers With A Slight Chance Of Tstms. Vsby 1 Nm Or Less. |
| Tonight...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt, Becoming W 5 To 10 Kt After Midnight. Seas Around 3 Ft. Patchy Fog After Midnight With Vsby 1 Nm Or Less. |
| Thu...Nw Winds 5 To 10 Kt, Becoming Ne 10 To 15 Kt In The Afternoon. Seas 2 To 3 Ft. Patchy Fog In The Morning. A Chance Of Showers In The Afternoon. Vsby 1 Nm Or Less, Increasing To 1 To 3 Nm In The Afternoon. |
| Thu Night...Ne Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 3 To 4 Ft. A Chance Of Showers. Vsby 1 Nm Or Less In The Evening. |
| Fri...Ne Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 4 To 5 Ft. A Chance Of Showers In The Morning. |
| Fri Night...Ne Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 4 To 5 Ft. |
| Sat Through Sun Night...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 3 To 5 Ft. Winds And Seas Higher In And Near Tstms. Seas Are Reported As Significant Wave Height, Which Is The Average Of The Highest Third Of The Waves. Individual Wave Heights May Be More Than Twice The Significant Wave Height. |
| Area Forecast Discussion National Weather Service Boston/Norton MA Issued by National Weather Service New York NY 1109am EDT Wednesday May 8 2024 Synopsis Showers and isolated thunderstorms move through the region this morning ahead of a warm front. Then a second round of scattered showers and thunderstorms develop this afternoon with a few strong storms capable of producing hail. Periods of unsettled weather continue late this week into this weekend with showers at times. Temperatures will average below normal late this week into the weekend. Milder/Seasonable temperatures should return early next week. Near Term - Through Tonight 11AM Most of the morning shower activity has pushed off to the east. Still some left over showers across the eastern portion of the area, however these should move out over the Atlantic over the next 1-2 hours. Key Points... * A second round of scattered showers and t-storms develop this afternoon. A few strong to marginally severe storms possible, with large hail the primary threat Then we will have to watch for a second round of scattered showers and t-storm development this afternoon as a fairly robust mid level shortwave moves into New Eng. Good cooling aloft as 500 mb temps drop to -16 to -18C will result in rather steep mid level lapse rates 7-7.5 C/km overspreading the region. This will contribute to MUCAPES 500-1000+ J/kg developing across much of the region this afternoon. Expect scattered convection developing as forcing for ascent increases ahead of the cold front. HREF max updraft progs suggest convective initiation in eastern NY and the Berkshires then scattered storms moving ESE across the region. While storms may be mostly elevated, potential exists for marginally severe hail given impressive effective bulk shear values of 50+ kt along with steep mid level lapse rates. Storm Prediction Center has all of SNE within a marginal risk but it appears focus for strongest storms will be from northern CT through interior MA. There is some uncertainty regarding the extent of surface based instability this afternoon due to presence of cooler low level airmass. Damaging wind threat will be dependent on surface based storms developing. Best chance of SBCAPES up to 1000 J/kg will be across western MA and northern CT as these areas may sneak into the warm sector ahead of a cold front, and decent low level lapse rates develop here. This is where strong to damaging wind threat will be highest with any strong storms. Highs may reach into the 70s across the Hartford to Springfield corridor with mostly 60s elsewhere. But temps may remain in the 50s across portions of NE MA. Short Term - Thursday and Thursday Night Tonight... Any convection lingering into the early evening will weaken and move offshore as subsidence develops behind departing shortwave along with somewhat drier air moving in with decreasing PWATs. Expect partial clearing developing in the interior, but stratus and patchy fog may linger in the coastal plain. Lows upper 40s and lower 50s. Thursday... The day should start out dry as a wedge of dry air will be over SNE. But moisture increases from the SW during the afternoon ahead of next shortwave dropping through the Gt Lakes and OH valley, with low pressure moving to mid Atlantic region. Risk of showers will increase during the afternoon. Highs should be mostly in the 60s, mildest CT valley and coolest along the coast in eastern MA where developing NE flow will likely hold temps in the upper 50s here. Long Term - Friday Through Tuesday Key Points... * More widespread rain possible Friday into Saturday night * Below average temperatures continue through the weekend * More seasonable temps return next week Friday A shortwave trough exits out of the Ohio River Valley becoming negatively tilted as it moves over SNE. The surface low is initially vertically stacked with the shortwave aloft and begins to occlude as new low forms and intensifies offshore to the east. Although the best forcing will be to the south of SNE, the chances for a widespread rain are increasing. As a mid level low passes over and intensifies to the south of the region, this will drag down rather cold 850mb air around 0C to -2C. With ENE winds at the surface, along with cold 850mb temps, low clouds, and rain, high temps may struggle to even reach 50F across the region. Rain looks to continue into Friday night before tapering off Saturday morning. Overnight lows look to drop into the low 40s, with upper 30s possible in the high terrain. Not out of the question that snow mixes in with rain across the high terrain in the Berkshires. Saturday Surface and midlevel low move well out to sea bringing widespread rain to end in the morning. However, an upper level closed low drops south over the region leaving SNE under cyclonic flow aloft. With weak forcing aloft and the mid level cold pool(a region of relatively cold air) still in place, this will likely lead to a hit or miss light showers/drizzle. High temps on Saturday don't look to recover much with thick low level cloud layer still around. High temps should only reach the low to mid 50s with continued onshore flow. Sunday Another weak surface low exits the Ohio River Valley and passes just south of SNE. This could bring another round of widespread light rain to the region. Uncertainty with this system remains high given the weak upper level forcing and not much run to run consistency on the track of the low. Highs remain below normal Sunday and could once again struggle to reach 50F. Next week The pesky upper level low and mid level cold pool(a region of relatively cold air) finally move east as a midlevel shortwave brings WAA (Warm Air Advection - the movement of warm air) and 850mb temps above 0C to even +10C by mid week. This will allow high temps to moderate back into the low to mid 70s. As for rain chances, high pressure to the south should keep things dry early in the week. Rain chances look to increase again mid to late week, but uncertainty is high at this time. Marine Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Through Thursday...High confidence. Low level jet will bring a period of SW gusts to 20+ kt to south coastal waters this afternoon. Winds diminish tonight, becoming north by Thu morning then NE 10-20 kt during Thu afternoon. Seas remain below SCA (Small Craft Advisory) thresholds. Areas of fog will reduce visibilities at times over south coastal waters through tonight. Scattered showers and embedded t-storms move through this morning into early afternoon. Outlook /Friday through Sunday/... Thursday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers. Friday through Friday Night: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain. Saturday: Winds less than 25 kt. Seas up to 5 ft. Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain. NOAA Boston MA Office: Watches - Warnings - Advisories CT...None. MA...None. RI...None. Marine None. |
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