Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
274 FXUS61 KGYX 192359 AFDGYX Area Forecast Discussion National Weather Service Gray ME 759 PM EDT Fri Jul 19 2024 .SYNOPSIS... A mainly dry and seasonable pattern continues through the upcoming weekend and into early next week. High pressure slides south of the region through tomorrow. A weakening cold front sags southward on Sunday and stalls, lingering into early next week. Moisture increases by midweek as a ridge builds into the Northeast, with showers and storms returning for Wednesday and Thursday. Drier weather likely returns by Friday and into next weekend as high pressure builds in from the west. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... 750 PM Update...Very little change to the forecast needed this evening. Just a few minor adjustments to temperatures and cloud cover based on latest trends in observational data. A fair weather evening will continue to be had. Previously... Seasonably warm but comfortable conditions will be the story the remainder of this afternoon with most seeing temperatures range from the upper 70s to lower 80s and dewpoints in the 50s. As we get closer to sunset, the diurnal cu will begin to fade as heating is lost, and temperatures will cool off pretty quickly this evening as winds will be a touch lighter than yesterday. This continues through tonight as skies remain mostly clear and am expected lows to be a couple of degrees cooler than last night/this morning. With the good radiational cooling, have leaned more on MOS, putting most in the 50s, except for a few closer to the coast remaining around 60. Normally cooler spots could dip into the low 50s along with upper 40s in some of the northern valleys. Patchy valley is again possible. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... High pressure sinks to the south and east on Saturday as a weak frontal boundary approaches from the north. Low-level flow becomes more southwesterly and temps aloft also warm, which will bring high temperatures back up a couple of degrees as good mixing will occur again. There will still be a significant amount of dry air aloft, which will keep skies mostly sunny (although there will be some cirrus moving in the afternoon), and the good mixing will also bring this drier air down, keeping humidity levels comfortable. Highs will be the low-mid 80s for much of the interior with some upper 80s across southeast NH and portions of SW Maine. The previously mentioned weak cold front will drop southward out of Canada Saturday evening and Saturday night. There`s not much going for this front, but it will bring an increase in cloud cover and a chance of showers across northern areas with mainly just increasing clouds for areas to the south. Temps are not expected to get quite as cool with most seeing upper 50s to lower 60s with dewpoints creeping upward ahead of the front. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Overview... A cold front stalls across New England as it sags southward on Sunday. The stalled front lingers into the middle of week as a ridge builds in from the southeast, bringing increasing moisture and chances for showers and storms. It takes until late in the week for the next front to push through to bring any meaningful clearing as high pressure gradually builds in from the west. Details... The front slowly presses southward during the day on Sunday, bringing with it a chance for some scattered showers or a stray thunderstorm. The timing of the front doesn`t serve well for more widespread convection, with leftover convection from the day before likely limping through northern areas during the morning. The front then stalls across New England, with a few more afternoon showers and storms developing near the front. The front then wobbles back and forth for a few days, with scattered showers and storms developing in the afternoon. Monday looks like the best chance for a dry day, with the front most likely south of our forecast area. By Tuesday, the front begins to drift northward with increasing moisture as the ridge builds along the Northeast coast. This threat increases into Wednesday as the front remains nearby while moisture continues to increase. Wednesday looks to feature the most widespread threat for showers and storms. There is the threat for some areas of heavier rainfall, but we`ll have to wait until we`re closer in time to try to pin down these locations and see where the stalled front has drifted to by that timeframe. By Thursday, a weak wave of low pressure may try to develop and drift along the front as a stronger cold front approaches from the west. Showers and storms are likely again on Thursday with these features, but then chances drop by Friday as high pressure begins to build in from the west behind the front. In terms of temperatures, temps look to remain warm for Sunday and into the first part of the week as the humidity increases. Wednesday and Thursday look like the only chances for highs to get close to or just a hair below normal with the rain and clouds. Then by Friday and into next weekend temps warm again as the sunshine returns. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... Short Term...Mostly VFR through Saturday night. Valley fog may brief a brief period of restrictions to HIE and LEB late tonight and early Saturday, and a weak cold front dropping southward out of Canada could bring a few showers and possibly MVFR ceilings to HIE Saturday night. Long Term...Mainly VFR prevails during the daytime Sunday through Tuesday, with nighttime valley fog likely each night. A stray afternoon shower or storm may bring brief restrictions at any terminal each day. On Wednesday and Thursday, showers and storms look more frequent with restrictions at times. VFR likely prevails from Friday into next weekend. && .MARINE... Short Term...Conditions across the waters are expected remain below SCA levels. Light south to southwest flow across the waters will continue through most of Saturday night before becoming more westerly as a weak cold front approaches toward daybreak Sunday morning. Long Term...A front stalls and lingers across the waters on Sunday through early next week. Areas of locally dense fog are possible starting on Tuesday. These conditions continue through the middle of the week as a weak wave of low pressure moves along the front Wednesday and Thursday. Pressure gradients remain weak through next week, so conditions mostly look to stay below SCA levels. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Combs/Ekster SHORT TERM...Combs LONG TERM...Clair