textproduct: Gray - Portland

WHAT HAS CHANGED

No significant changes to the forecast with this update.

KEY MESSAGES

1. High pressure will dominate the weather for the next week. Expect dry conditions and no significant weather impacts.

DISCUSSION

KEY MESSAGE 1 DESCRIPTION...

High pressure remains the dominating force behind our local weather for the foreseeable future. That will bring largely fair weather, dry conditions, and on average warmer than normal temps.

It is fall however, and those temps will experience some dips here and there. One of those dips will be following the passage of a mostly dry cold front tonight. Temps will struggle to creep out of the 40s for even southern parts of the forecast area, and remain in the mid 40s north of the mtns. There should be enough dry advection and gradient wind to prevent significant radiation fog tonight.

Then we just recycle the forecast pattern. High pressure will build into the region. This provides us with perhaps the coldest night of the season so far Tue night. I did continue to blend in some MOS guidance in order to bring the cold spots down into the teens and lower 20s, but otherwise the NBM bias corrected guidance is pretty locked onto the radiational cooling pattern.

That high pressure will move off the coast and allow return flow to develop late in the week. This will bring warmer than normal temps back into the forecast area and give us a couple more chances as some readings near 70 across southern NH and coastal western Maine.

Another largely dry frontal passage is expected heading into Sat, but that just returns temps to near normal. So trick or treating conditions will be classically crisp.

AVIATION /18Z MONDAY THROUGH SATURDAY/

Through Tuesday: VFR conditions anticipated. There should be enough breeze behind the cold front and dry advection to prevent valley fog from forming.

Outlook...

Wednesday-Thursday...VFR conditions expected. There may be brief period of IFR or lower in valley fog at LEB, CON, and MHT prior to sunrise.

Friday: Another front approaches the region and some MVFR CIGs may be possible north of the mtns, including HIE.

Saturday: VFR conditions expected.

MARINE

A cold front is forecast to cross the waters tonight, bringing gusty northwest winds. A brief period of SCA wind gusts is expected into Tue before winds diminish under another approaching high pressure. As that high departs the region late in the week, southwest winds will increase. They will at least approach SCA gusts and allow seas to build in the vicinity of the coastal waters north of Port Clyde, but overall I expect conditions to remain below SCA thresholds.

GYX WATCHES/WARNINGS/ADVISORIES

ME...None. NH...None. MARINE...Small Craft Advisory from midnight tonight to 10 AM EDT Tuesday for ANZ150-152-154.