textproduct: Boston / Norton

WHAT HAS CHANGED

No significant changes to the forecast.

KEY MESSAGES

- High astronomical tides with less than a foot of storm surge could cause minor coastal flooding for the late evening high tides.

- Mostly dry Wednesday but there is a chance for scattered pop- up showers and thunderstorms across western/central New England and some showers over the Cape & islands.

- Gusty southerly winds with some showers and perhaps a few t-storms on Thursday. Watching the severe weather potential too...But right now thinking main threat will be to our west and/or south.

- Beautiful stretch of weather Friday into the weekend with highs mainly between 75 and 85 degrees with the warmest of the days being Friday. Comfortable humidity the entire period.

- Perhaps a period of much needed rain to kick off the start of the next work week...But that is uncertain given 6+ days in the future.

DISCUSSION

KEY MESSAGE 1...High astronomical tides with less than a foot of storm surge could cause minor coastal flooding for the late evening high tides.

Astronomical tides continue to very slowly come down through the week, overall lessening the coastal flooding/splashover risk each day. Still expecting at least one to two more tide cycles reaching just into minor flooding. Highest confidence of localized coastal flooding will be the high tide late tonight/early Wednesday morning, and a coastal flood statement remains in effect for this reason. There is potential that this statement will need to be extended through Wednesday but confidence is too low at this point.

KEY MESSAGE 2...Mostly dry Wednesday but there is a chance for scattered pop-up showers and thunderstorms across far western/central New England and some showers over the Cape & islands.

A relatively quiet day expected on Wednesday, if not as quiet as today. Southerly flow will increase as SNE becomes sandwiched between a surface high pressure over the western Atlantic and an approaching low over the Great Lakes. This will advect more moisture into the region with PWATs rising from 0.5" today to around 1" Wednesday while dewpoints also rise from the mid 40s to the low to mid 50s. This will make it feel modestly more humid but not bad while also increasing cloudcover and moisture content for some scattered showers and thunderstorms. Not expecting widespread coverage of showers/t-storms but the best chance for an afternoon storm will be in western and central MA where we'll have several hundred J/kg of CAPE combined with lift from a weak mid level shortwave. Secondarily, Cape Cod and the islands may get some showers from the periphery of a weak low passing well offshore.

KEY MESSAGE 3...Gusty southerly winds with some showers and perhaps a few t-storms on Thursday. Watching the severe weather potential too...But right now thinking main threat will be to our west and/or south.

Approaching mid level shortwave/warm front will be crossing the region Thu morning. Modest lift will likely result in a cluster of elevated showers and perhaps an embedded t-storm or two mainly Thu morning. The bulk of this rain may end up northwest of I-95 and especially west/northwest MA given their closer to the better dynamics. After the first round of showers departs...a 50+ knot southerly LLJ will result in gusty southerly winds depending on how much heating we are able to realize. Perhaps on the order of 25 to 35 mph seems reasonable at this time. Again...that could be less/more depending on the amount of heating we are able to realize. Right now we have highs in the upper 70s to near 80 given elevated showers and a lot of clouds.

While this first round of showers will tend to diminish Thu afternoon...the window for surface destabilization ahead of the approaching cold front may be limited. There may also be subsidence behind this first round of showers. That being said...we still will need to watch the risk for severe weather too given strong wind fields/jet dynamics...But right now thinking that the main risk will be to our west and/or south where better instability likely resides.

KEY MESSAGE 3...Beautiful stretch of weather Friday into the weekend with highs mainly between 75 and 85 degrees with the warmest of the days being Friday. Comfortable humidity the entire period.

Two closed upper level lows just south of Hudsons Bay will result in height fields lower than normal Friday into this weekend across the Northeast. This will suppress deeper moisture to our south and result in a beautiful stretch of weather. High temperatures will generally be between 75 and 85 with comfortable humidity. Overnight low temperatures will mainly be in the 50s to the lower 60s.

Generally dry weather is on tap over this time period too. Some northern stream energy may result in a diurnally driven brief spot shower or two...But for all intensive purposes dry and beautiful June weather is on tap.

KEY MESSAGE 4...Perhaps a period of much needed rain to kick off the start of the next work week...But that is uncertain given 6+ days in the future.

Quite a bit of uncertainty for the start of the next work week. Some of the guidance has a low pressure system tracking near or south of us. If that were too happen...the potential would exist for a period o some much needed rain sometime Mon into early Tue. But given lack of baroclinicity in the summer and convective processes that are usually involved...it is way too early to have any confidence especially given it is 6+ days in the future. Something to watch though in the coming days.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Forecaster Confidence Levels...

Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

This afternoon...High confidence.

VFR. NW winds for the inland terminals. Winds shift SSW for PVD and Cape/Island terminals mid-afternoon. Local seabreezes develop this afternoon along the east coast (BOS). Timing is moderate confidence, but should more likely develop between 20-22Z. Winds shift back toward S/SSW 00-03Z.

Tonight...High Confidence.

VFR. Light SW winds less than 10 kts.

Wednesday...High Confidence.

VFR. Mid-level ceilings developing through the day. Winds SSW 5-10 kts for most terminals. S/SSE winds for BOS around 8-12 kts.

Wednesday Night...High Confidence.

VFR to start, lowering to MVFR/IFR ceilings ahead of rain showers for Thursday morning.

KBOS Terminal...Low confidence (sea breeze timing). Sea breeze may develop late, most likely around 21z if it does. There remains a probability that sea breeze remains just offshore. KBDL Terminal...High confidence in TAF.

Outlook /Wednesday Night through Sunday/...

Thursday: Mainly VFR, with local IFR possible. Windy with local gusts up to 30 kt. SHRA likely, slight chance TSRA, patchy BR.

Thursday Night through Friday Night: VFR. Breezy.

Saturday: VFR. Windy with local gusts up to 30 kt.

Saturday Night: VFR. Breezy.

Sunday: VFR. Breezy. Slight chance SHRA.

MARINE

Forecaster Confidence Levels...

Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

Through Wednesday night: High confidence.

Winds and seas to remain below Small Craft Advisory thresholds through Wednesday night. Some gusts around 20 kt possible this afternoon around the Cape and islands, especially across the southern coastal waters.

Outlook /Thursday through Sunday/...

Thursday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Local rough seas. Chance of rain showers, patchy fog.

Thursday Night: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Rough seas up to 8 ft. Slight chance of rain showers.

Juneteenth: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 7 ft. Slight chance of rain showers.

Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain showers.

Saturday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft.

Saturday Night: Winds less than 25 kt. Seas up to 5 ft.

Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft.

BOX WATCHES/WARNINGS/ADVISORIES

CT...None. MA...None. RI...None. MARINE...None.