textproduct: Gray - Portland

WHAT HAS CHANGED

Strong to severe storms continue into the late afternoon hours. A coastal flood statement has been issued for high astronomical tides tonight.

KEY MESSAGES

1. Strong to severe storms cross through the early evening hours with a passing cold front.

2. High astronomical tides bring water levels to near flood stage again tonight.

3. A seasonable day follows behind the front for Friday.

4. Seasonable summertime conditions expected through the weekend and into next week, with at least a couple of chances for showers and storms.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

Scattered strong to severe storms remain possible into the early evening hours as a cold front crosses through northern New England. Strong winds remain the primary concern with these storms. As we've seen today, even widespread sub-severe winds are capable knocking down trees and causing power outages. So this threat continues into the late afternoon before pushing offshore by early evening.

A seasonably cool night follows behind the front tonight, with lows in the upper 40s across the north, to mid 50s in most other locations.

KEY MESSAGE 2 DESCRIPTION...

One more night of high astronomical tides bring water levels to near minor flood stage again tonight. With the astro tides starting to lower, water levels tonight should be lower than the last couple of nights.

KEY MESSAGE 3 DESCRIPTION...

A seasonable and dry day is expected on Friday as broad high pressure builds in from the southwest. A deepening trough across northeast Canada keeps a dry and relatively cool airmass streaming in on a west-northwesterly flow. Widespread highs in the 70s to low 80s are expected, and wildfire smoke looks to be directed south of northern New England for the day tomorrow.

Friday night looks similar to tonight with lows in the upper 40s to mid 50s from north to south. Clouds begin to increase during the overnight hours tomorrow night as moisture arrives from the west. Any shower activity looks to hold off until after daybreak Saturday morning

KEY MESSAGE 4 DESCRIPTION... The weekend should both start and end dry, but in between, we'll see a round of showers along with a chance of thunderstorms. There's still some timing differences among model solutions, but the trend is for increasing rain chances from west to east in the afternoon and evening hours on Saturday as a 500mb shortwave and associated surface low and cold front approach from the west. Showers should then taper off late Saturday night into Sunday morning behind the cold front. However, there may be a few showers linger into Sunday afternoon, but these should be mainly in the mountains. As far as amounts, ensembles support mostly 0.25" to 0.50" south of the mountains and 0.50" to 1.00" in the mountains. High temperatures will be generally in the mid 70s to low 80s, although southern NH may see some mid 80s on Saturday.

High pressure follows for Monday bringing a dry day, but shortly after that, there's pretty good consensus among the global models in a 500mb trough crossing the Great Lakes and sending a cold front toward New England around the middle of next week. This will bring the next chance for widespread shower activity and maybe a few storms. This is supported by a strong signal within the ensembles centered around Wednesday for the higher precip chances (but could be more Tuesday-Wedesday or Wednesday-Thursday at this point). Otherwise, temperatures remain fairly seasonable with model consensus being in the 70s and 80s.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Brief restrictions in heavy showers and a few thunderstorms continue into the late afternoon across southern terminals. VFR then returns tonight, and prevails through tomorrow night. Nighttime valley fog will be possible Friday night.

Outlook...

Saturday-Saturday night: Saturday begins VFR, but then chances for MVFR to IFR restrictions increases later in the day along with SHRA and possible TSRA. The higher chances for IFR (and possibly lower) arrive Saturday evening into Saturday night.

Sunday: Conditions expected to return to VFR in the morning, except lingering MVFR ceilings and SHRA possible at HIE.

Monday: VFR expected.

Tuesday: MVFR to IFR possible as chances for SHRA and a few TSRA increase through the day.

MARINE

Squalls and thunderstorms continue across the waters into the early evening hours. Fair conditions then return late tonight and continue through Friday night with broad high pressure building in.

Saturday-Thursday...SCA conditions are likely on Saturday and Saturday night as south to southwest winds increase ahead of a cold front. The front crosses early Sunday morning, shifting winds to W and NW. These will likely subside under SCA levels, but seas could stay above 5 ft much of the day. High pressure builds in for Monday, keeping conditions under SCA levels, and then the next front brings another chance at SCA conditions toward the middle of next week (be Tues-Weds or Weds-Thurs).

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...Air Quality Alert until 11 PM EDT this evening for NHZ001>015. MARINE...None.