![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
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
798 FXUS61 KGYX 131024 AAA AFDGYX Area Forecast Discussion...UPDATED National Weather Service Gray ME 624 AM EDT Tue Aug 13 2024 .SYNOPSIS... High pressure will continue building in today, with mostly sunny skies and warm temperatures. It will be a dirty high pressure however, and by midweek showers and thunderstorms are likely to form during the heat of the afternoons. A more organized chance of rain is unlikely until next weekend with the approach of a cold front. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Update...Minor changes to reflect latest observational trends. Previous discussion...Return flow will allow temps to be warmer this afternoon...with most locations climbing into the 80s south of the mtns. S/WV ridging should tend to suppress any chances for convection this afternoon. If showers do manage to form...they will be most likely in the higher terrain...where orographic forcing may provide enough lift. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/... Quiet conditions again tonight...with very similar temps and coverage of valley fog is expected. By Wed afternoon cooler temps aloft will allow for afternoon instability despite surface high pressure. The lack of shear will preclude an organized severe thunderstorm threat...but ample CAPE is forecast. Ultimately that should lend itself to pulse type storms that may briefly reach near severe thresholds. CSU machine learning guidance supports a marginal threat of both large hail and damaging winds. The loss of daytime heating should bring a relatively quick end to convection. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... Overview: Daily chances for afternoon showers this week, some thunder mixed in. Thunder chances will be greater Thurs afternoon as a boundary drops out of Quebec. Surface high pressure moves in late week. Low pressure then advances into the Great Lakes this weekend, with rain chances increasing late. Details: Wednesday night, this trough organizes into an upper low, remaining overhead Thursday. Elevated instability remains, and a few persistent overnight showers are be possible. The placement of the low could bring similar conditions for Wednesday in terms of shower/thunder potential. High pressure moves into the Northeast Friday and early this weekend. This will bring lower chances of daytime showers, but the next weather maker will be moving into the Great Lakes for additional rain chances late this weekend. Overall, daytime and overnight temps ride within a few degrees of normal, perhaps cooler if cloud cover prevails during the day. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... Short Term...Local LIFR conditions in the CT River Valley will lift this morning as daytime heating mixes out the low levels. Otherwise widespread VFR conditions expected today. Another round of local LIFR in valley fog is possible tonight...most likely at HIE and LEB. Then Wed scattered SHRA/TSRA will develop during the afternoon. Local MVFR or lower conditions are possible in convection...though confidence in location is low. Long Term...SHRA Thursday. This could prompt occasional MVFR ceilings at times. Fog may develop Wed night, bringing some visibility restrictions across the interior. Little notable winds. && .MARINE... Short Term...Winds and seas expected to remain below SCA thresholds. Afternoon sea breezes are likely to prevail under a weak pressure gradient. Long Term...Below SCA conditions with waves 1 to 2 ft. Broad upper level low pressure forms Thurs over New England. This will bring some showers to the waters, but little notable wind speeds. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ SHORT TERM...Legro