textproduct: Caribou

WHAT HAS CHANGED

- Updated aviation section to reflect upcoming 12z TAFs

- Decreasing chance for rain Thursday night through Friday, with any rain chances being confined to the Central Highlands down through the coast

KEY MESSAGES

1) A warming trend accompanies dry weather this weekend into early next week.

2) A bit of light rain is expected for some areas tonight into Thursday night but a widespread soaking rain is not expected.

DISCUSSION

KEY MESSAGE 1...A warming trend accompanies dry weather this weekend into early next week.

KEY MESSAGE 1 DESCRIPTION... The upper level trough will finally, gradually exit to the east heading into this weekend. A broad ridge of high pressure will settle in its place. This will lead to a southwest dominant flow across our forecast area, advecting warm air into the region. The particular airmass that is entering the region will contain abnormally warm temperatures across the eastern half of the CONUS. For our area, at the northern end of the ridge, temperatures will rise above average by around 5 degrees or so. This may lead to temperatures into the low 70s across the north and low to potentially mid 70s across Bangor and the Interior Downeast region. If the departing upper level trough takes longer to shift east or the center of the incoming high pressure sets up further south, these temperatures may not warm as much. If the ridge that develops is stronger than currently projected, it may have a more dominant influence over our forecast area and temperatures could trend warmer than currently projected.

Skies will be mostly clear during the subsidence pattern into this weekend, with limited available atmospheric moisture as PWATs are forecast to be less than 1 inch, falling to less than a half inch by Sunday afternoon. Some fair weather cumulus may develop during Saturday afternoon, with a slight chance for some of these cumulus to develop further into light diurnally driven showers. By Sunday, a drier day is in store, not only in terms of less precipitation but also the potential for rapidly dropping dewpoints resulting in relative humidity that could plummet below 30 percent.

Should the ridge remain overhead into early next week as currently projected, temperatures may continue to climb through the first half of next week, with Bangor and the Interior Downeast region potentially seeing temperatures make a run towards 80 by Tuesday. Daily cloud cover and precip chances will have a large influence on daily high temperatures as well. For Monday into Tuesday, the positioning of a warm front north of the CWA will determine how warm the northern half of the forecast area gets Monday and Tuesday. If the warm front stalls across Aroostook County, rain showers and cloudy skies could keep temperatures dampened, though temperatures may still lift into the upper 60s and remain above average. Without this cloud cover and rain, say the warm front stays well north of the CWA, the environment in the north will more closely match Downeast Maine and daily high temperatures could make a run for the upper 70s through Tuesday.

KEY MESSAGE 2...A bit of light rain is expected for some areas tonight into Thursday night but a widespread soaking rain is not expected.

KEY MESSAGE 2 DESCRIPTION... Upper level low pressure across the great lakes region will move southeast, remaining southwest of the region through Thursday night. Some light rain is expected to develop tonight. But upper ridging from the Canadian Maritimes is expected to build westward toward the region. This will result in any rainfall that does develop to be on the light side tonight. Rainfall amounts are expected to generally be less than one tenth of an inch through tonight. Upper ridging remains during Thursday. Once again, rain will have a hard time moving into the area, with the best rainfall chances remaining to the south and west of the area. Rainfall amounts on Thursday are generally expected to range up to about a tenth of an inch for the Bangor region, with less than a tenth of an inch to the north.

The 500mb low pressure cuts off over northern New England Thursday night into Friday, while the upper level trough becomes neutrally tilted. With this synoptic shift, the surface low that develops will likely be kept south of the area. Recent model runs have trended south with this low, keeping precip chances confined to closer to the coast. The northern half of the forecast area will likely remain mostly dry, and even Bangor and the Interior Downeast region could see a decreasing trend in forecast rain amounts should this low continue to track south of the Gulf of Maine.

AVIATION /09Z WEDNESDAY THROUGH SUNDAY/

Today...VFR. Low chance MVFR ceilings will move into KBGR/KBHB by late afternoon. S wind 5 to 10 kt. Gusts to 20 kt possible.

Tonight...MVFR/IFR expected. S to SE wind 5 to 10 kt. Low level Wind Shear.

Thursday...MVFR/VFR. E to SE wind 10 to 15 kt.

Thursday night - Friday night...VFR at northern terminals, MVFR at KBGR/KBHB in rain. NE winds 5 to 10 kts becoming light and variable Friday night.

Saturday...Generally VFR across all terminals. Brief -SHRA possible at northern terminals in the afternoon. SW winds 5 to 10 kts with gusts to 20 kts.

Sunday...VFR across all terminals. W to NW winds 10 to 15 kts gusting 20 to 25 kts.

MARINE

Winds/seas are expected to remain below SCA levels through tonight. Winds/seas could approach SCA levels on Thursday.

Seas increase into the day on Friday as a low pressure system crosses the waters, with seas lifting to 5 to 9 ft with a SE long period swell before subsiding Friday night. Gusts may briefly touch 25 kts on the coastal and outer waters early on Friday. Winds increase once more this weekend, with gusts 25 to 30 kts by Saturday night and seas increasing to 5 to 7 ft, then will decrease Sunday night into Monday.

CAR WATCHES/WARNINGS/ADVISORIES

ME...Frost Advisory until 9 AM EDT this morning for MEZ015>017-029- 030. MARINE...None.