textproduct: Gray - Portland

WHAT HAS CHANGED

No significant changes since the previous forecast cycle.

KEY MESSAGES

1. Mostly dry weather with seasonal temperatures is expected through Saturday as high pressure builds toward New England.

2. An unsettled pattern returns with rain Sunday night into Monday morning, with shower and thunderstorm chances returning for the latter half of the week. Seasonable temperatures are expected through the period.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

Surface high pressure will build to our southwest today as we remain on the western periphery of an H5 s/wv trof axis. Mainly sunny skies during the morning will become partly cloudy during this afternoon as some weak daytime instability develops. Other than perhaps an isolated shower/rumble of thunder across SW NH it will be a dry day with high temperatures near 70 across the north with upper 70s to lower 80s south. NW wind gusts up to 25-30 mph will be possible at times.

The combination of weakening winds, clear skies, and relatively low dew points will allow for radiational cooling tonight. Forecast lows range from the middle 40s across some interior valleys with 50s in most other locations. Valley fog is possible late through early Saturday morning.

High pressure will allow for continued tranquil weather on Saturday with partly to mostly sunny skies and high temperatures ranging from around 70 across the north to near 80 south. Radiational cooling is then likely again Saturday night with low temperatures into the 40s and 50s.

KEY MESSAGE 2 DESCRIPTION...

High pressure will begin to exit to our east on Sunday as closed low pressure moves across the Great Lakes while spreading a warm front northward across the Delmarva. This area of low pressure is then progged to move northeastward Sunday night into Monday with a weak coastal low possibly developing near or over the Gulf of ME. After a dry and seasonable day on Sunday, rain chances will increase Sunday night into at least Monday morning with scattered showers possibly continuing into the afternoon hours. Latest ensemble mean QPF shows generally between 0.50-1.00" of rainfall during this period but there are some individual members with higher totals. Given the ongoing dry conditions across much of the region, this will largely be beneficial rainfall but cannot rule out some minor issues if heavy rainfall falls in a short period of time.

Mainly dry conditions look to return for Tuesday into Wednesday as low pressure departs to our north and east. Temperatures will remain near seasonable averages. Showery weather may return late week as another disturbance approaches from the west.

AVIATION /02Z FRIDAY THROUGH TUESDAY/

Valley FG at LEB and HIE will likely bring IFR restrictions or worse between 06Z-12Z Friday. Otherwise, VFR conditions are expected on Friday with NW gusts up to 25 kts. VFR conditions are expected Friday night with light and variable winds. Valley FG is once again possible at LEB and HIE late at night through early Saturday morning. Mainly VFR conditions are then expected Saturday through 00Z Monday before RA arrives along with lower CIGS. VFR conditions return for Tuesday.

MARINE

Winds stay out of the northwest through tonight but could be more westerly at times for a period this afternoon. Winds and seas will remain below SCA criteria though. Low pressure will move up the St Lawrence Valley Sunday night and Monday morning with a warm front passing over the waters Monday. An uptick in southerly winds is expected, but may fall just short of SCA criteria for the coastal waters. High pressure then returns over the waters for the middle of the week.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...None.