Area Forecast Discussion
Issued by NWS Caribou, ME

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000 FXUS61 KCAR 180726 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 326 AM EDT Fri Aug 18 2017 .SYNOPSIS... A warm front will approach the region from the west today and will move across the area tonight. An occluded front will slowly cross the area Saturday and Saturday night. High pressure builds to the south of Maine Sunday into Monday. && .NEAR TERM /THROUGH TONIGHT/... Showers to spread across the region today and tonight, especially Downeast, where locally heavy rainfall is possible. Low pressure currently spinning over the Michigan UP will slowly move eastward today and tonight. Moisture is already lifting northward out ahead of the system, as evidenced by showers on seen on radar. This activity will slowly push eastward through the day; expect eastern areas will remain dry much of the day as the showers will need to overcome the dry airmass that is in place. Highs will be in the mid 60s to around 70 in most locations. Showers will become more numerous this evening - particularly Downeast - as the warm front lifts onshore, ushering in deep moisture. The warm front will quickly be followed by an occluded front which will march from west to east late tonight into Saturday. Out ahead of this second front, PWATs of 1.75-2.0 inches will spread across Downeast, especially along the coast. This combined with warm cloud depths of 12-14 kft will allow for locally heavy rainfall, particularly along the coast. Note that much of Downeast Maine is currently included in WPC`s Excessive Rainfall Outlook. Elevated instability will exist out ahead of the occluded front as well, so expect we`ll have some rumbles of thunder in southern portions of the forecast area. It`ll be a muggy night with lows in the upper 50s to lower 60s. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... The weekend will not be a wash-out, but will have some shower activity, more so Saturday. Saturday will start with a warm front across central Maine with an occluded front to the west of the area. The best chance of steadier rain will likely be saturday morning across the Downeast Region. As the occluded front moves closer to the area more showers will likely develop across western portions of the forecast area in the afternoon. The day will feature a lot of low clouds and some fog in the morning, and it is doubtful that much of the area sees any sunshine, but clouds may thin for a few breaks in the afternoon across central and western portions of the area. The occlusion comes through Sat night with a few more showers and is followed by an upper trough Sunday. Sunday will feature more clouds than sun in the north and mountains along with a few showers, although most of the day will be dry. Further south, the Downeast Region and along the coast will start with clouds than will give way to a partly sunny sky. Temperatures Saturday will be near average for the second half of August, and and Sunday will be a few degrees above average. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... A surface ridge crests to the south of the area Sun night and moves east Monday. It looks dry with above average temperatures. The GFS does have a weak disturbance and attempts to generate a late day shower in a few spots across the north woods, but chances look slim and will keep it dry for now. The air mass is quite warm Monday with 925H temps around +22C Downeast, and with a decent amount of sunshine and a downslope wind m/u 80s are expected. Highs will likely top 80F all the way north to the Saint John Valley. Attention turns to a sharp upper trough digging into the Great Lakes Region Tue night and Wednesday with a lot of energy and a deep surface low for this time of year that is expected to be to the west of the area by 12Z Wed. The models differ on the depth and position of the low that will have important implications on the sensible weather across northern and eastern Maine. Some initial overrunning rain is possible Tuesday, mainly across northern areas. Most of the area stands to pick up some rainfall Tue night and Wednesday, but the details on where the heaviest rain will fall still remain uncertain. Somewhat drier by Thu, but with an upper trough in the vicinity a couple of showers still can`t be ruled out. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... NEAR TERM: VFR conditions will prevail at all sites through at least 22z Friday, though showers will be spreading from west to east through the day. Expect ceilings will lower to MVFR to IFR at the southern terminals shortly thereafter; the northern sites will see ceilings lower to around 1500 ft around 00z Sat and then remain there much of the night. Visibilities will be reduced to 3-5SM at times in rain and patchy fog after 00z Sat. SHORT TERM: IFR conditions likely to start the day Sat with LIFR possible, especially at KBHB. Conditions will likely improve to MVFR, at least at the northern terminals from KHUL to KFVE by Sat afternoon. Predominately MVFR Sat night into early Sun, with conditions to improve to VFR by afternoon, except for some patches of MVFR ceilings across northern areas. VFR expected Sun night through Tue, with the possible exception of any patches of late night fog or in any showers later in the day Tue. && .MARINE... NEAR TERM: A Small Craft Advisory is in effect for tonight into Saturday. Winds and seas will increase today and especially tonight as low pressure lifts to the north and west of the waters today, bringing an occluded front across the waters late tonight. Gusts of 25 kt and seas of 4-6 feet are expected after 8 pm tonight, continuing through daybreak Saturday. SHORT TERM: Small craft advisory level seas are expected through Saturday evening. Areas of fog will produce poor visibility at times through Sun morning. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory from 8 PM this evening to 8 PM EDT Saturday for ANZ050>052. && $$ Near Term...Hastings Short Term...CB Long Term...CB Aviation...Hastings/CB Marine...Hastings/CB

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