####018006775#### FXUS61 KCAR 162135 AFDCAR Area Forecast Discussion National Weather Service Caribou ME 535 PM EDT Fri May 16 2025 .SYNOPSIS... A front will remain stalled across Maine through Saturday. Low pressure will slowly cross the area Saturday night through Sunday night, then slowly exit to the east Monday through Tuesday night. Weak high pressure builds in on Wednesday. && .NEAR TERM /THROUGH SATURDAY/... A nearly stationary frontal boundary will remain across northern Maine tonight, while an upper level disturbance approaches from the west. Showers/thunderstorms, most numerous across northern/central portions of the forecast area, will persist this evening. Showers/thunderstorms will then diminish early tonight with the loss of diurnal heating. Isolated/scattered showers will then persist across mostly northern/central areas overnight. Satellite imagery indicates areas of fog and low clouds along the Downeast coast which will move inland across Downeast areas tonight. Patchy fog is expected across northern areas later tonight. A vertically stacking surface/upper system will approach from the west Saturday. Shower/thunderstorm coverage will increase Saturday in advance of the approaching system. With persistent moisture, some of the thunderstorms could produce locally heavy rain Saturday afternoon. The better chances for heavy rain Saturday will be across west-central portions of the region. Low temperatures tonight will range from the upper 40s to mid 50s across the forecast area. High temperatures Saturday will range from around 60 to the mid 60s across much of the forecast area, with mid to upper 50s along the Downeast coast. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... Diffluent flow aloft ahead of an approaching cutoff low will support locally heavy showers continuing Saturday night, especially over western portions of the forecast area, where upslope flow will help to enhance any precipitation. Showalter indices are down to around 1 or 2, so have a slight chance of thunder in to reflect the potential for elevated convection. Lows Saturday night should be around 5-10 degrees above normal. The cutoff low should track along/near the boarder between NY/VT/NH and Canada Sunday morning, then across southern Maine Sunday afternoon and evening, then into Nova Scotia by Monday morning. This will allow for continued showers across the region, diminishing in coverage as the low moves to the S/E of a given area. Locally heavy rainfall with any stronger convection remains possible. Showalter indices rise to above 4, so do not have thunder in the forecast during this time frame. Highs Sunday should be around 5 degrees below normal and lows Sunday night a few to around 5 degrees above normal. The cutoff low tracks slowly along/just south of the coast of Nova Scotia on Monday, with continued showers across the region, with the best chance over mainly the North, with the best forcing. With the region on the cool side of the cutoff - no longer have an expectation for locally heavy rainfall. Highs on Monday should be around 10-15 degrees below normal. Refer to the hydrology section of the AFD for details on expected QPF and any impacts from the rainfall Saturday night into Monday. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... The cutoff low gradually weakens as it slowly tracks into the southeastern Maritimes Monday night-Tuesday. Should see mainly isolated to scattered showers, with coverage decreasing from NW to SE as the storm pulls away. Weak ridging builds into the area Tuesday night and Wednesday. This should allow for things to begin to dry out, with slight chance pops mainly Tuesday evening. The models then differ on the timing/strength/track for possibly another cutoff low for late next week. Based on the uncertainty have limited pops to chance Wednesday night-Friday. There is a small number of ensemble members that suggest that this system could be far enough south, that we could receive little or no impacts, but right now most ensemble models would suggest a period of at least unsettled weather Wednesday night- Friday. The large degree of uncertainty precludes specifying what, if any, impacts this system might have. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... NEAR TERM: VFR/MVFR local IFR early tonight, then IFR/LIFR occasional VLIFR overnight with fog. Showers along with isolated/scattered thunderstorms early tonight, with isolated/scattered showers overnight. IFR/LIFR, occasional VLIFR, early Saturday with fog. MVFR/IFR, occasional LIFR, Saturday afternoon. Showers and thunderstorms Saturday. Some of the thunderstorms could produce heavy rain. South/southeast winds 5 to 10 knots tonight. Southeast winds 10 to 15 knots with gusts up to 20 knots Saturday. SHORT TERM: Saturday night-Sunday night: IFR or lower likely, with conditions possibly improving to MVFR in locations by late Sunday night. Locally heavy rainfall possible, with best chance at northern terminals. LLWS possible at southern terminals Saturday night. Monday-Tuesday: MVFR or lower possible. NW-N winds G15-25KT possible. Tuesday night-Wednesday: MVFR with gradual improvement towards VFR possible. NE-E winds G15-20KT possible. && .MARINE... NEAR TERM: Winds/seas below small craft advisory levels tonight through Saturday. Areas of fog tonight through Saturday. SHORT TERM: SCA conditions are possible on the coastal ocean waters Saturday night and Sunday, and should remain below SCA levels on the intra-coastal waters during this time. All waters should see sub-SCA conditions Sunday night, then SCA conditions are possible on all waters Monday and Monday night. Sub-SCA conditions should then return to the waters Tuesday and continue into Wednesday. && .HYDROLOGY... A widespread rainfall of 2/3 to 1.5 inches is expected across the region from tonight through Sunday night, with highest amounts over the Central Highlands and North Woods. Locally heavy rainfall is possible with any stronger convection, during this time frame, with locally higher amounts up to 3 inches possible, especially over areas that experience multiple rounds of rainfall. This could cause localized minor flooding of mainly known poor drainage areas. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ Near Term...Norcross Short Term...Maloit Long Term...Maloit Aviation...Norcross/Maloit Marine...Norcross/Maloit Hydrology...Maloit ####018004278#### FXUS66 KSEW 162138 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 238 PM PDT Fri May 16 2025 .SYNOPSIS...Cloudy and showery conditions will continue across the region through the weekend with temperatures remaining below normal. The chance of thunderstorms will increase to around 20 percent across much of the region Saturday afternoon. Showers continue through the start of next week as the pattern remains somewhat active. A shift to warmer conditions is possible late next week. && .SHORT TERM /TONIGHT THROUGH MONDAY/...Onshore flow prevails and western WA remains under cloudy skies with isolated to scattered showers. Temperatures are only in the 50s or around 5-10 degrees cooler than average. More showers are headed our way tonight and Saturday as an upper level trough moves in. Showers will be enhanced during the afternoon with the passing trough axis and a convergence zone developing in the interior. The air mass will be slightly unstable with a chance of thunderstorms too. Up in the mountains, snow levels will lower from around 4500' down to 3500' Saturday night and the Cascades may see light snowfall accumulations. A cool upper low remains overhead on Sunday for more clouds, light showers, and overall cool conditions. Most of she shower activity remains over the Cascades where snow levels stay low (3500-4500'). We'll see a brief break in the weather with a ridge late Sunday, then more rain on Monday with the next frontal system. Temperatures remain cooler than average with highs around 60 degrees. 33 .LONG TERM /TUESDAY THROUGH FRIDAY/...There is broad troughing over the Pac NW next week with ongoing onshore flow. A series of weak upper level systems will clip the area for a chance of showers through the period. Late in the week (and next weekend) there are signs of warmer and drier weather with stronger ridging over the region. The majority of the ensemble members show highs reaching the 70s over the weekend. 33 && .AVIATION...Westerly flow aloft will become southwesterly tonight as the next in a series of upper troughs and associated weak fronts approaches Western Washington. The air mass remains moist with widespread MVFR ceilings. Shower coverage will increase overnight into early Saturday with ceilings dropping to low MVFR or IFR. KSEA...Mainly MVFR ceilings expected through the evening with any low end VFR improvement expected to be brief. Showers will increase late tonight into Saturday with low MVFR or occasional IFR ceilings. Surface winds S/SW 7 knots or less turning light and variable during the overnight period then returning to S/SW and increasing to 8 to 12 knots by later Saturday afternoon. 27 && .MARINE...Another front will dissipate as it moves into the coastal waters overnight. Surface high pressure will then rebuild over the coastal waters later Saturday into Sunday. This will produce increasing onshore flow and headlines for the coastal waters, strait, and northern portions of the inland waters. The next frontal system will arrive on Monday. 27 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory from 3 PM Saturday to 11 AM PDT Sunday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm-West Entrance U.S. Waters Strait Of Juan De Fuca. Gale Warning from 3 PM Saturday to 5 AM PDT Sunday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. Small Craft Advisory from 5 PM Saturday to 11 AM PDT Sunday for Northern Inland Waters Including The San Juan Islands. Small Craft Advisory from 3 PM Saturday to 5 AM PDT Sunday for Admiralty Inlet. && $$