129 FXUS61 KCAR 211347 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 947 AM EDT Tue May 21 2019 .SYNOPSIS... Low pressure will move eastward across the Canadian Maritimes today. High pressure builds eastward over the area Tuesday night into Thursday. Another area of low pressure will track across the region Thursday night into early Friday. && .NEAR TERM /THROUGH TONIGHT/... 945 am update... Cold air conts to filter into nrn zones as sfc winds hv bcm nwrly and gusty. Hv updated grids to ingest latest obs and hv bumped wind gusts up accordingly this morning into this aftn. Rain looks to continue thru the day as lopres wl slowly become stacked this evng and upr lvl cold pool rotates thru nrn and ern zones tda. No other chgs needed at this time. Previous Discussion... Below normal temps and wet wx will continue Today. Sfc analysis showed low pres moving across the region w/showers setting up across the north and west. Another round of showers was moving across the coastal areas this morning ahead of the cold front. The low will become stacked as the upper low moves across the region w/rain and showers filling back in later this morning and continuing through the afternoon. The highest concentration of rainfall will be across the northern 1/2 of the CWA where percentages were raised to 80-100%. Elsewhere, chances will drop off w/less forcing and a NW wind leading to some downsloping. This will be most evident down across the Maine Central Highlands and Downeast w/the potential for partial clearing. The latest HRRR and RAP were handling things well currently and blended their trends into the forecast through the afternoon. Temperatures will be the warmest this morning and then drop back during the day w/the colder filtering into the region. Fog had developed along the Downeast region this morning, but will lift w/the passage of the cold front. WNW winds will pick up this afternoon as the colder air moves in. Stayed close the daycrew's thinking of bringing sustained winds up to 10 to 20 mph and gusts getting close to 30 mph in some spots, especially across open and higher terrain. The rain will gradually wind down this evening as the low exits to the east. Winds will continue to stay up overnight w/a good deal of cloudiness around. The NAM handles this setup well and decided to keep skies mostly cloudy throughout the region. The clouds and wind will keep temps from dropping too low. At any rate, it will be chilly night w/overnight lows expected to be in the mid/upper 30s n and w and around 40 or so across the central and downeast areas. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Wednesday will feature a cool north wind with some gusts over 20 mph. With abundant H925/H850 moisture, clouds will cover most of the forecast area through the day...thinning later in the day as drier air advects from the southwest. Cannot rule out scattered light showers in the northern zones due to a very modest unstable layer around H850, but will not include pops at this time. Ridging both at the surface and aloft builds through the day...and with some late afternoon clearing, highs may reach the upper 50s north and lower 60s towards Bangor and Lincoln. On Wednesday night, the ridging continues to build with a 1024mb surface high settling over the state. With a relatively cool air mass in place, lows will dip into the mid to upper 30s across most of the forecast area and have included patchy frost in some of the normally colder spots...mostly in Aroostook County. Temperatures will quickly warm Thursday morning under sunny skies. Highs will reach the mid to upper 60s for the entire area except the coast where the onshore winds will limit highs to the upper 50s and lower 60s. Will keep pops out of the forecast until Thursday night. On Thursday night, a compact upper low will ride over a powerful upper ridge centered over the southeastern US. This northern stream system will propagate into the area Thursday night. With the 00Z guidance, chances have increased that the entire forecast area will have showers Thursday night. While this system could have been problematic in terms of convective activity had it arrived during the daytime, it’s nighttime arrival precludes mention of any thunder at this time. Elevated convection may reach the western zones before midnight, but it’s too uncertain to mention in the forecast at this point. Clouds will keep lows from dropping below the mid to upper 40s. && .LONG TERM /FRIDAY THROUGH MONDAY/... In the extended forecast for the long weekend, Friday will gradually dry out as clouds and precip slowly depart from the Thursday night disturbance. The upper high over the southeastern US strengthens later in the day. The subsidence will help push Friday’s highs into the mid to upper 60s in northern Aroostook, but lingering clouds and cool onshore winds will keep highs in the mid 50s for Eastport, Machias and Bar Harbor. The ridging will provide decent weather Saturday morning, but high clouds will increase during the afternoon. Most areas inland will reach the mid 60s, but the coast will continue experience onshore winds. Pops ratchet up later Saturday afternoon into Sunday night. A warm occlusion crosses Saturday night. Warmer air in place on Sunday could propel temperatures into the mid to upper 60s except the coast. There’s still the question of lingering showers...mostly in northern zones. Another frontal system arrives Monday in the fast upper flow, but highs will remain in the 60s away from the coast. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... NEAR TERM: Expecting IFR/LIFR w/rain and patchy fog, to continue for the northern terminals through late morning and then a general improvement to MVFR into the afternoon. Conditions are expected to drop back to IFR tonight as the cigs lower across the north. VFR for KBGR and KBHB today w/periods of MVFR this morning w/VFR tonight. NW winds will be increasing this afternoon into the evening w/gust potential to 25 kt especially across the northern terminals. SHORT TERM: MVFR cigs are possible Wednesday morning north of GNR and HUL. Otherwise, VFR is expected until Thursday night when IFR cigs will probably develop later in the night and continue into Friday morning at all sites. VFR returns for all terminals by Friday afternoon and continues until late Saturday afternoon when the trend will be towards IFR cigs by later Saturday night. && .MARINE... NEAR TERM: Winds and seas have come down this morning to 10 kts and 3 ft respectively. There is a change coming later this afternoon into tonight and NW winds increasing w/the cold air moving down from the n. This will lead to winds gusting to 25+ kts by this evening into the overnight period. Given this potential, decided to put up a SCA, which includes the intra coastal zone. Even though winds are expected to remain below 5 ft, there will be a chop. SHORT TERM: A potential SCA will end early Wednesday and the next issue could be fog later Thursday night into Friday morning. Another SCA is possible later Saturday night. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory from 4 PM this afternoon to 6 AM EDT Wednesday for ANZ050>052. && $$ Near Term...Farrar/Hewitt Short Term...MCW Long Term...MCW Aviation...Farrar/Hewitt/MCW Marine...Farrar/Hewitt/MCW