FXUS61 KCAR 112039 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 339 PM EST Wed Dec 11 2024 .SYNOPSIS... Intensifying low pressure will track west of the region tonight, then lift north across Eastern Canada Thursday. High pressure will build in for Friday through the weekend. Low pressure will approach from the west on Monday. && .NEAR TERM /THROUGH THURSDAY/... The large low pressure system will continue to track the center across the west this evening and bring the cold front through the region tonight. Winds: The low level jet will push in from the south, over the waters, and into the Downeast coast which will increase S flow this evening. Before midnight, winds will increase drastically with the cold front approaching the region. The main areas of concern will the the coastal and interior Downeast and the Bangor Region. This is due to the S flow and the history of S progressing through the Penobscot bay and river causing impacts in Bangor. Around midnight, the low is expected to intensify, causing the front to pick up speed and increase winds across the upsloping of the Central Highlands and along the eastern border. As the front starts to exit after midnight, high res models indicate that the pressure gradients on the backside of the front will tighten again, causing a brief increase of winds in the North Woods. Though short lived and weaker than previous runs, decided to include this wind increase for impact purposes. In addition, the HRRR has pointed to the possibility of a more stable boundary layer due to possible snow pack surviving the rain and warm temps. If the snow pack is a constant layer, there is a possibility that winds will have a hard time mixing to the surface with the latent heating. However, if the snow pack is patchy or gone, then winds will remain at forecasted values. Rain: As the cold front moves across the region tonight, bands of high rain rates will move across the region. The main area of concern will be the upsloping areas of the Central Highlands and the downsloping in the North Woods. Though these higher rain bands will move across certain areas, instability along the front will cause some convection to develop, thus localized heavier rain is possible. In addition to the rainfall, the snowpack will be melting, causing extra runoff on frozen ground. Though rivers are not as big of a concern, small streams, creeks, and urban street flooding is a concern. By Thursday, the low will exit over the Maritimes with wrap around moisture bringing snow showers across the region throughout the day. Cold air behind the front will gradually drop temps throughout the day with the majority of the region remaining in the upper 30s. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... High pressure will begin to build into the area through the end of the week and into the weekend. This will lead to drier weather and clearing skies. Temperatures will be mild, with highs in the 20s over most of the forecast area, and near 30 closer to the coast. Lows Thursday night may only fall into the upper teens to lower 20s, but by Friday night could fall into the lower teens across the forecast area. Light winds may linger through the short term, limiting surface decoupling chances and preventing temperatures from rapidly plummeting much further. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... High pressure will linger through this weekend. With mostly clear skies and light winds, full surface decoupling may be possible such that temperatures could fall into the lower single digits above zero Saturday night, particularly across the north. Otherwise, temperatures may remain slightly below average through the rest of the weekend. A low pressure system will approach from the west through early next week. There remains great uncertainty for when this system will enter the area, with the GFS and CMC bringing a small shortwave over the area Monday night into Tuesday and bringing the first round of light precipitation into the region. Meanwhile, the Euro hangs on to high pressure over the area. The main low may not move into the area until Tuesday night into Wednesday. Ensemble plots agree on a slower progression of this trough, though there remains the slight chance of showers ahead of the main low. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... NEAR TERM: IFR/LIFR for this evening and into tonight due to low cigs and rain. Rain will become heavy at times for all terminals. LLWS all tonight for all terminals. S winds 20-25 kts with gusts up to 50 kts. By Thursday, MVFR through the morning, then improving to VFR by the afternoon. SW winds 10-15 kts with gusts up to 20 kts. SHORT TERM: Thurs night - Fri night: VFR across all terminals. SW winds 5 to 10 kts, gusting 20 to 25 kts Thurs night, gradually diminishing through Fri and Fri night. Sat - Mon: VFR across all terminals. W winds around 5 kts becoming light and variable Sat night, then turning S on Sun at 5 to 10 kts. && .MARINE... NEAR TERM: The Storm Warning is in effect through tonight with seas 13-20 ft. Winds should decrease by Thursday morning to gale force throughout the day with seas 11-16 ft decreasing to 7-12 ft by the afternoon. SHORT TERM: Winds will quickly decrease back towards small craft advisory levels through Thursday night, and may continue to decrease below 25 kts by late Friday night. Seas with a long period southerly swell will gradually decrease through the end of the week, reaching 3 to 5 ft by Friday night. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...Flood Watch through Thursday morning for MEZ001>006-010-011- 015>017-029>032. Wind Advisory from 7 PM this evening to 6 AM EST Thursday for MEZ001-003-004. High Wind Warning from 7 PM this evening to 6 AM EST Thursday for MEZ002-005-006-010-011-015>017-029>032. MARINE...Storm Warning from 7 PM this evening to 7 AM EST Thursday for ANZ050>052. && $$ Near Term...LaFlash Short Term...AStrauser Long Term...AStrauser Aviation...LaFlash/AStrauser Marine...LaFlash/AStrauser