912 FXUS61 KCAR 150545 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 145 AM EDT Fri Apr 15 2022 .SYNOPSIS... An occluded front will cross the area overnight and continue east across the Maritimes tomorrow. Low pressure will approach later Saturday, then cross the region Saturday night. Upper level low pressure will cross the region Sunday. High pressure will cross the region Monday. Another low will cross the region Tuesday. && .NEAR TERM /THROUGH TODAY/... 145 am update... Update to ingest temps and dwpts into fcst but no changes needed to pop and wx grids. Prev Disc: A warm front is trying to lift north but at the surface there is cooler air that isn't being scoured out of the area. This is thanks to southerly flow right off the colder Gulf of Maine and the air mass is a cold air damming for this time of year. This is noted in the inverted MSLP plot in the model guidance today. Light steady rain will push northeast into New Brunswick with a gap in between with showers. The occluded front is going to push into Vermont and Quebec this evening with a weak wave of low pressure developing over the Gulf of Maine. This will bring quickly back the likely to categorical pops across the northern 2/3rd with chance to likely pops Downeast. By daybreak tomorrow morning the front will be pushing through the western zones bringing an end to precip from west to east. With the clouds, rain and flow off the Gulf of Maine expect lows in the low 40s across southern zones and mid to upper 30s across the north. Rain totals generally less than 0.5 inch with perhaps the highest totals 0.5-0.6 inch in the North Woods on the "ripe" snowpack. In addition to the rain tonight with light southeast winds expect areas of fog to develop across the area. Cannot rule out some locally dense fog especially in areas that still have snowpack across the north. Winds shift W-SW behind the front and decent pocket of surface ridging tries to push up over the area with modeled 850-250mb RH values in the 25-35% range. This would suggest rapid clearing with sunshine in the morning behind the cold front. Tomorrow will feature an air mass that is much warmer with 925mb temps +6C to +8C with light SW flow. This means highs in the upper 50s to low 60s across southern areas including the Greater Bangor area around 63F. In the north it will be a nice warm spring day with highs in the mid to upper 50s. This will likely add to more snowmelt and continued ice jam threat (see hydrology section below). Another weak boundary will push into northern areas with 500mb vorticity max coming across that will kick off some scattered showers and some increased cloud cover. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... A cold front will approach northern Maine later Friday night. Expect mostly cloudy skies along with increasing rain shower chances across mostly northern areas Friday night. Across Downeast areas, expect increasing clouds along with a slight chance of showers late. The front slowly moves south across the region Saturday, approaching Downeast areas late. At the same time, low pressure will develop along the front across southern New England and begin to track toward Maine. A steadier rain will develop across the region Saturday with the approach of the low. The surface low will track across Downeast areas early Saturday night, then exit across the Maritimes late. Upper level low pressure will also approach, from the west, late. Rain will taper to showers later Saturday night. Across Downeast areas, precipitation will remain in the form of rain. Temperatures aloft will cool across northern areas later Saturday night with the approach of the upper low. Cooling temperatures aloft...along with diurnal cooling...should allow precipitation across the north to mix with or change to snow later Saturday night. Dependent on the extent of remaining precipitation, light snow accumulations could occur. The upper low crosses the region Sunday, keeping unsettled conditions with a chance of showers. Snow showers or mixed rain/snow showers will occur across the north and mountains early Sunday. Otherwise, expect a chance of rain showers across the region. Expect near normal level temperatures Saturday/Sunday. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... The upper level low exits across the Maritimes Sunday night, while high pressure approaches from the west. Expect decreasing clouds Sunday night. High pressure crosses the region Monday, with low pressure approaching from the west late. Expect mostly sunny skies Monday, then increasing clouds Monday night with a chance of rain late. A snow/rain mix is possible across northern areas. Low pressure will cross the region Tuesday, then exit across the Maritimes Tuesday night. Rain Tuesday, will taper to showers Tuesday night. Across the north and mountains, the precipitation should taper to snow showers. Upper level troffing will cross the region Wednesday. Expect mostly/partly cloudy skies Wednesday with a chance of rain showers, possibly mixed with snow showers across the north and mountains early. Low pressure should approach Thursday, though the timing is uncertain. Expect near normal level temperatures Monday/Wednesday/Thursday, with below normal level temperatures Tuesday. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... NEAR TERM: LIFR/ocnl VLIFR early this morning will give way rapidly to to VFR by early morning over Downeast terminals with northern terminals by early afternoon. VFR thru tonight with LLWS picking up twd end of TAF time at BGR and BHB, but closer to 06z over the north. SHORT TERM: Friday night...VFR/MVFR north with a chance of rain showers. VFR Downeast with a slight chance of rain showers late. South/southwest winds around 10 knots. Saturday...MVFR/IFR north. VFR/MVFR, then MVFR/IFR Downeast. Developing rain. Southwest winds around 10 knots, becoming variable. Saturday night...MVFR/IFR, occasional LIFR. Rain tapering to snow/rain showers north, tapering to rain showers Downeast. Variable winds around 10 knots, becoming northwest. Sunday...VFR/MVFR. A chance of rain showers. Possibly mixed with snow showers across the north and mountains early. Northwest winds 10 to 20 knots with gusts up to 25 knots. Sunday night...Occasional MVFR possible across northern areas early. Otherwise, VFR. Northwest winds 10 to 15 knots with gusts up to 20 knots. Monday...VFR. Northwest winds 10 to 15 knots, becoming variable 5 to 10 knots. Monday night...VFR early. MVFR/IFR late. A chance of rain late, possibly mixed with snow across northern areas. Variable winds 5 to 10 knots, becoming southeast/east 10 to 15 knots. Tuesday...MVFR/IFR, occasional LIFR. Rain. A rain/snow mix possible early north. East/southeast winds 10 to 20 knots with gusts up to 25 knots, becoming variable around 10 knots. && .MARINE... NEAR TERM: Winds are gusting to 25-30kts across the outer waters this evening but will begin to fall below SCA conditions. Waves will remain 4-5ft across the outer waters so extended the Small Craft Advisory from this package update till 8am tomorrow. Wave period is generally 6-7sec. Winds/waves fall below SCA after 8am tomorrow. Intra-coastal waters remain below SCA tonight through tomorrow. SHORT TERM: Small craft advisory conditions Friday night into Saturday night. Conditions below small craft advisory levels Sunday. Rain Saturday through Saturday night. A slight chance of showers Sunday. && .HYDROLOGY... The threat of ice jams continues on the Saint John and Allagash Rivers due to jamming over locations where ice is thicker or it encounters islands and/or substantial bends in the river. There remains an approx 9 mile jam between Dickey and St. Francis. There is an additional jam on the Allagash in town where ice cannot discharge into the St. John. There is another small jam that is causing minor flooding between Lille and Grand Isle mainly impacting farm fields at this time. The latest snow survey data from Monday and Tuesday indicates snow water equivalent of 5 to 9 inches and snow depth of 18 to 29 inches from Winterville north through Allagash, indicating that there is still a significant amount of snow left to melt across the Saint John and Allagash River basins. Further south along Route 11, snow water equivalents were less than 5 inches with snow depths less than 15 inches. High temperatures will reach upper 40s to mid 50s for the next few days. Continued river level rises are likely and ice jams remain possible across the Allagash and Saint John Rivers into this weekend. Precipitation will mainly fall in the form of rain through the weekend and be generally less than 0.5 inch total over the St. John Valley. Any additional rainfall will be falling into "ripe" snowpack so the potential for accelerated snowmelt is possible. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory until 8 AM EDT this morning for ANZ050- 051. && $$ Near Term...Buster/Sinko Short Term...Norcross Long Term...Norcross Aviation...Buster/Sinko/Norcross Marine...Buster/Sinko/Norcross Hydrology...