


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
424 FXUS61 KGYX 091016 AFDGYX Area Forecast Discussion National Weather Service Gray ME 616 AM EDT Wed Apr 9 2025 .SYNOPSIS... High pressure brings a return to drier and warmer conditions for the middle of the week. A cutoff low then stalls south of New England on Friday through the weekend, bringing an extended period of cool and unsettled weather conditions. The system then moves away early next week with a return to drier and warmer conditions. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 615 AM Update... Minor changes to reflect latest observational trends. Previously... Latest RAP13 surface pressure analysis early this Wednesday morning shows low pressure located over Nova Scotia with broad cyclonic flow prevailing over New England. Northeast radar mosaic does show some weak returns extending from the mountains down through the Capital Region of ME and towards the Mid-Coast. ASOS observations along with webcam imagery indicates this is resulting in some visibility restrictions (especially over the Mid-Coast) but little in the way of additional snow accumulation is expected. Therefore, cancelled the winter weather advisory a little early. Locally slippery travel is still likely though this morning as any residual moisture/slush has since frozen. Will likely need to issue a special weather statement to highlight this threat within the next hour or so for the commute. It will otherwise remain a brisk morning with windchills into the single digits and teens. Low pressure will continue to retreat well to the northeast of the region today as high pressure begins to nudge in from the southwest. Gusty northwesterly winds will persist through this afternoon due to the combination of the lingering pressure gradient force along with deep mixing. Gusts between 25-35 mph can be expected. Speaking of mixing, moisture profiles indicate that we will be tapping into a very dry airmass aloft this afternoon, which will help to lower RH down into the teens for some areas south of the mountains. It will otherwise be a partly sunny day as high Froude Numbers will likely result in some added cloud cover this afternoon. It will be unseasonably cool with high temperatures only into the 30s to middle 40s from north to south. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... High pressure will move across the region tonight, resulting in mainly clear skies as well as light and variable winds. This combined with the low dew points that will be in place will set the stage for likely strong radiational cooling. Used MOS guidance for overnight lows, which brings some valleys down into the lower teens with 20s elsewhere. High pressure will begin to move offshore on Thursday ahead of the the next storm system. This will allow for gradually increasing clouds from west to east but southerly flow will help to boost high temperatures into the upper 40s/low 50s away from the coast. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... 1040 PM Update...Little change to the extended forecast. Main focus continues to be on potential rainy system for the weekend, possible starting as wintry precipitation for some locations Friday night. Overview... High pressure exits New England on Thursday night, and settles northeast of the region across Atlantic Canada through the weekend. Low pressure moving up the East Coast from the Southern US becomes cut off and stalls south of New England, bringing an extended period of unsettled and cool conditions. The low likely doesn`t begin to move away until early next week as a more progressive trough pushes in from the west. Details... As the low drifts northward, the high pressure will thwart its progress and cause it to stall to the south. This sets up a steady east-northeasterly flow that keeps much of northern New England in a cool airmass from Friday through Sunday. Additionally, waves of precip will be weakening as they approach from the south starting Thursday night. The first push of moisture approaches Thursday night, and will be steadily weakening as it moves northward. Models, led by the Euro, have been trending toward a drier solution during this time period. POPs have been trended accordingly for the Thursday night into Friday time period, with room to go lower so long as the model trends continue. The day on Friday then looks mostly dry, with the best chance for a shower across southern New Hampshire, and the most sunshine likely across northern areas. By later Friday night and Saturday, a more substantial push of precipitation likely moves in as the low makes its closest pass. Conditions will be cool enough for some snow, especially across the interior and higher terrain, but precip type will likely be more dependent on precip intensity, with snow confined more to heavier rates. This precip shield will also be weakening as it moves in, so there still remains much uncertainty on precip type, as well as amounts. The low continues to degrade to our south through Sunday and into Monday, keeping the chance for showers around into Monday. The best chance for these will be along the coast, with more clearing expected through the day on Monday. With the clouds and rounds of precip, temps start out cool early in the weekend with highs in the 40s on Saturday. As more sun breaks through on Sunday, highs likely recover back to the 50s, and then 60s again by Monday. However, with any cut off low situation the progression is far from certain from this far out, and these systems have a history of moving more slowly than earlier thinking. So we`ll continue to monitor the forecast over the next few days, and won`t be surprised if the progression slows down more over the next several model runs. A more progressive trough likely swings into the Great Lakes by the Tuesday to Wednesday timeframe next week, helping to clear the last of the cut off low and bring in a drier westerly flow. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/... Short Term...Any lingering flight restrictions due to -SN/low ceilings will improve back to VFR within an hour or so of 12Z this morning. Otherwise, VFR conditions can be expected today with northwesterly wind gusts between 25-30 kts. Winds will become light tonight with VFR prevailing. VFR will persist on Thursday with developing southerly flow. No LLWS is anticipated at this time. Long Term...Some MVFR ceilings possible across southern terminals Thursday night and Friday. MVFR to IFR conditions likely arrive from south to north Friday night, with rain likely south, and rain and snow likely across northern terminals. IFR conditions likely linger through Saturday, with gradually more breaks of MVFR ceilings from Saturday night through Sunday. Conditions likely gradually return to VFR from west to east Sunday night through Monday. && .MARINE... Short Term...Low pressure will exit well to the northeast of the waters today with high pressure building in tonight through Thursday. This will result in weakening winds and seas to below SCA criteria later today. Long Term...High pressure settles across the Canadian Maritimes for Friday through the weekend, as low pressure stalls south of New England. An extended period of SCA conditions are likely in northeasterly winds from Friday night through Sunday. The low then moves east by early next week. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until noon EDT today for ANZ150-152-154. Small Craft Advisory until 10 AM EDT this morning for ANZ151- 153. && $$ NEAR TERM...Tubbs SHORT TERM...Tubbs LONG TERM...Clair/Ekster