textproduct: Gray - Portland

WHAT HAS CHANGED

Some valley fog has developed this morning and should continue for another hour or two before lifting. No major changes were needed for this update.

KEY MESSAGES

1. Pleasant weather continues through the weekend under high pressure.

2. Precipitation chances Tuesday-Wednesday, but conditions improve towards the second half of the week. Seasonable temperatures continue.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

Broad high pressure will become centered overhead today through Saturday. This will continue fair weather with highs in the 80s and lows in the 50s. Conditions will be favorable for sea breezes that will push inland during the afternoons. High pressure will continue fair weather Sunday as the center slowly drifts east of the area.

KEY MESSAGE 2 DESCRIPTION...

An upper-level low moving through Hudson Bay will amplify a trough over the Northeast U.S. by early in the week. The low-level response will be a surface low that likely tracks across New England or southern Quebec. With it still being ~5 days out, plenty of model spread exists. Next rain chance centered only general the GFS and GEFS ensemble are further south, less amplified, and more progressive, while the ECMWF/EPS ensemble are both further north/more amplified with a surface low closing off up through 500 mb. Dry weather should make a return towards the end of the week, but the exact timing of that remains fuzzy.

In terms of local impacts, generally a similar but less anomalous setup to the downpours/t-storms that affected us these last few days. Pretty confident we will see PWATs reach at least 1.5" with dew points well into the 60s, which should support heavy downpours. Once again see a signal for a bit of a cold pool aloft with lowering heights and temperatures aloft, which would support modest instability developing especially with any sunny breaks. As such will likely have a few waves of downpours/t-storms both Tuesday and Wednesday, with the greatest concentration during the afternoon hours each day when instability is maximized. Despite the increasing humidity, should have seasonable if not slightly cool temperatures, given the increased cloud cover and lowering 500 mb heights/1000-500 mb thickness by midweek.

AVIATION /12Z FRIDAY THROUGH WEDNESDAY/

Through 12Z Saturday: VFR conditions expected. The exception is at KLEB and KHIE where some valley FG may continue for another hour or two. Winds will remain light through today with and afternoon sea breeze likely at coastal TAF sites.

Outlook...

Saturday - Monday: VFR prevails.

Monday Night - Wednesday: Showers and storms likely bring brief periods of MVFR to IFR conditions. But outside of any rain, mainly MVFR to VFR ceilings are expected.

MARINE

High pressure settles over New England through the weekend allowing for winds and seas to remain below SCA conditions. Afternoon sea breezes likely freshen onshore winds during the afternoons. A slow moving frontal system approaches Monday and crosses Tuesday into Wednesday. Southerly winds will increase ahead of the front Tuesday.

GYX WATCHES/WARNINGS/ADVISORIES

ME...Beach Hazards Statement through this evening for MEZ023>028. NH...Beach Hazards Statement through this evening for NHZ014. MARINE...None.