textproduct: Caribou

WHAT HAS CHANGED

- Updated aviation discussion.

KEY MESSAGES

1) Potential for frost tonight inland from the coast and north.

2) A coastal low will impact at least Downeast Maine late this week.

DISCUSSION

KEY MESSAGE 1...Potential for frost tonight inland from the coast and north.

KEY MESSAGE 1 DESCRIPTION... The Frost Advisory has been expanded to include interior Hancock and central Washington counties. Surface 1040mb high pressure is centered over Quebec this afternoon, with upper level high pressure building into the region from Ontario. This pattern will continue tonight, resulting in clear skies and light winds, similar to last night. Once again this should result in a cold night, frost, and river valley fog. A modifying air mass could limit how low temperatures fall tonight, but lows in the 30s are expected outside the Downeast Coast. Northern areas of Maine will likely reach freezing or below freezing. While not as cold as tonight, Thursday night could see additional patchy frost and fog, mainly in northern areas as clouds increase from the south.

KEY MESSAGE 2...A coastal low will impact at least Downeast Maine late this week.

KEY MESSAGE 2 DESCRIPTION... A coastal low is expected to develop across the Mid-Atlantic region late this week while high pressure remains centered over Quebec. The timing and track of the ocean low is still uncertain with blocking high pressure to the northwest of our forecast area and ridging across the Great Lakes. Latest ECMWF guidance delays the onset of rain into the weekend as the blocking high remains resolute over Eastern Canada. This will result in additional uncertainty in how close the low will pass to the coast which will determine how far north the precipitation will reach. Regardless, northerly to northeasterly winds will become gusty over the weekend, especially along the coast, as a tight pressure gradient forms. General trend currently is that the low pressure system will continue to move southwards due to the high pressure, with majority of the rain staying over the waters and the Downeast region.

AVIATION /00Z THURSDAY THROUGH MONDAY/

Tonight...Variable conditions in patchy fog late. Otherwise, VFR. Light and variable winds.

Thursday...Variable conditions in patchy fog early. Otherwise, VFR. Variable winds 5 to 10 knots.

Thursday night...Variable conditions in any patchy late night fog, otherwise VFR. North/northeast winds 5 to 10 knots.

Friday - Monday...VFR north. VFR/MVFR Downeast with likely rain. Across northern areas, N/NE winds 5 to 10 knots, becoming NE Sunday. Across Downeast areas, N/NE winds 10 to 15 knots with gusts up to around 20-25 knots at KBGR, and 30 knots possible at KBHB Saturday and Sunday afternoon. Winds diminish Sunday night back to 10 to 15 knots.

MARINE

Winds/seas below small craft advisory levels tonight through Thursday.

Northeast winds and seas increase to gales late Thursday night into Friday, winds peaking around 45 knots in the outer waters and around 40 knots in the coastal waters by Friday night. A gale watch is now in effect from 8AM on Friday in outer waters and from 5PM in coastal waters and will persist through at least 8PM Sunday night. Gales remain possible in the intracoastal waters. Peak wave heights in the outer waters will be around 11ft to 16ft, and around 7ft to 12ft in the coastal waters.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Frost Advisory from midnight tonight to 7 AM EDT Thursday for MEZ015>017. MARINE...Gale Watch from Friday afternoon through Sunday evening for ANZ050-051. Gale Watch from Friday morning through Sunday evening for ANZ080-081.