textproduct: Gray - Portland

WHAT HAS CHANGED

No significant changes since the previous forecast.

KEY MESSAGES

1. Cool conditions prevail through Sunday with chances for snow showers, mainly in the mountains. Dry conditions are expected next week with warm days and cool nights.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

Periods of light rain will persist for portions of the region through this afternoon with snow mixing in across northern NH and northwestern ME. Minor snow accumulations remain possible, especially for elevations of around 1400 ft and above. The upper level low that is responsible for this precipitation will exit tonight, leaving behind gradually clearing skies and light northerly flow. Low temperatures will be into the 20s to lower 30s. Surface high pressure will build across the Great Lakes region on Sunday as we remain under broad cyclonic flow from low pressure located well to our northeast. This upslope flow will allow for additional rain and snow shower activity across the mtns and towards the Canadian border with mainly dry conditions further to the south. NW wind gusts may approach 25-30 mph during the afternoon with high temperatures ranging from around 40 degrees across the north to near 50 south. Any lingering precipitation across the north will end Sunday evening with low temperatures mainly into the 20s areawide.

There remains strong agreement in latest global and ensemble based guidance that broad high pressure will build across the eastern half of the CONUS through much of next week. This will result in mainly dry conditions with warm days and cool nights. Daytime highs will likely reach the upper 50s to perhaps lower 60s some afternoons south of the mtns before radiational cooling allows for 20-30+ degree diurnal ranges some days.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

Through Sunday: Mainly VFR conditions will persist for most TAF sites. The exceptions are at HIE where MVFR-IFR restrictions and SHSN will persist through at least Sunday AM along with LEB where MVFR restrictions are possible through this evening. N flow will prevail through tonight at 5-15 kts. Winds will become NW on Sunday with afternoon gusts up to around 25 kts possible. Forecast confidence is moderate through the period.

Outlook:

Sunday Night: MVFR restrictions possible at HIE but otherwise VFR conditions with light and variable winds. Forecast confidence is moderate.

Monday-Thursday: An extended period of VFR conditions are likely. Forecast confidence is moderate.

MARINE

A few NW wind gusts may approach 25 kts Sunday evening outside of the bays with seas of 2-4 ft. Otherwise, winds and seas will largely remain below SCA criteria through next week as high pressure builds across the eastern CONUS.

GYX WATCHES/WARNINGS/ADVISORIES

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