Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
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401 FXUS61 KGYX 231902 AFDGYX Area Forecast Discussion National Weather Service Gray ME 302 PM EDT Mon Sep 23 2024 .SYNOPSIS... Despite being hundreds of miles away, an ocean storm continues to bring large waves to the nearshore waters and keep water levels high. That will continue into Tuesday but we will start to see both wave heights and water levels diminish. A narrow area of high pressure will wedge into the region during the middle of the week, with dry weather and seasonable temperatures. Then later in the week we will see a more widespread chance of showers. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Cool pool aloft has led to the development of plenty of flattening cu out there this afternoon. A few sprinkles remain possible thru the early evening...but otherwise dry. Overnight high clouds will try and clear to the east...but also more are streaming in from the southwest. First I do not expect temps overnight to be as cold as last night. Second that makes fog a little uncertain overnight. I think the major river valleys will see some fog so I have kept the patchy wording there. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Wind direction looks to become a little more south of east Tue. With largely the same air mass aloft I anticipate cu to break out as the day heats up. There have been some ocean effect type showers and sprinkles today across MA...so I could see some of those sneaking into southern NH during the afternoon Tue. I have added sprinkles for the time being. A few more clouds around Tue night should prevent temps from radiating too much...and may also disrupt fog development...so I have none in the forecast currently. The nearshore waves will continue to slowly diminish Tue as well. Current forecasts are right on the threshold of high surf...and the rip risk is not forecast to hit high levels. So it is possible we could go headline free on the coast Tue. However I could see need for something like a rip statement being necessary given the prolonged nature of this east northeast flow event. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Models still in fairly good agreement that 500 MB trough dice equatorward through ON Wed and Wed night, then closes off over S QC on Thursday and crosses N ME Thursday night, which will bring showers to the region, most pr=prevalent Wed night into Thu. By Friday it should be clearing, with a day of cooler air, but still around normal, before a ridge develops Sunday and hold through early next week. This ridge will also provide some above normal temps to the region. On Wed, will see increasing clouds, although in the W zones it may end being mostly cloudy all day, while the further E you go the better chance you have for more sun in the morning. Cant rule out a few afternoon showers in the mtns as the trough deepens to the E, and some WAA starts to move in, but the bulk of the rain holds until Wed evening. Highs will generally range from the low 60s in the N to the mid to upper 60s in the S. Wed night into Thu will be the best chance for rain in the CWA as a wave moves in to the base of that trough just to our N and closed it off. The dynamics will be combined with WAA aloft on Wed night, and then a cold front will follow on Thursday. So showers move across Wed night with maybe a break short break early Thu, followed by another round of showers with cold front late morning into the afternoon. Total QPF Wed night through Thu ranges from about a third of an inch in srn NH to near a half inch in central ME and the mid coast, to maybe three quarters of inch in parts of the mtns. Lows Wed night should wet bulb into the low to mid 50s, with highs on Thursday generally in the low to mid 60s, but could see a run at 70 in S NH where, some clearing is possible mid to late afternoon. Some showers linger in the E zones Thu evening, but should see clearing outside the mtns after midnight with lows 50-55. There could be some light showers or sprinkles in the mtns Friday morning as wave tracks around the W side of the 500 MB and maybe partly sunny skies, but should see clearing by Friday afternoon with highs in the mid 609s to low 70s. The weekend into Monday should be mainly sunny and dry with highs in the upper 60s to mid 70 and lows from about 45-55. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... Short Term...CIGs have largely lifted above MVFR thresholds this afternoon. Overnight loss of diurnal heating should allow lower clouds to dissipate...but high clouds will linger. This leads to some uncertainty with radiation fog development...but I am leaning towards fog in the favored valleys. I have IFR or lower conditions at the typical hot spots of LEB and HIE...but it is possible that fog may sneak into CON. VFR conditions return Tue...but I do anticipate some clouds to develop around 4000 ft. Long Term...VFR expected Wed, although flight restrictions are likely by late Wed night through much of Thursday, in rain and low cigs. The restrictions will likely linger in the mtns and at KAUG and KRKD Thu night, but should see a return to VFR everywhere Friday morning, with VFR through the weekend. && .MARINE... Short Term...SCA conditions continue thanks to seas above 5 ft. Northeast winds continue thru Tue...so the sea state is expected to remain fairly consistent thru that time. Long Term...5-6 ft seas will continue through Thu, but should them subside Thu night, with no SCA criteria expected through the weekend. && .TIDES/COASTAL FLOODING... With storm surge running just under 1 ft across most of the coastal waters...water levels at high tide this afternoon should remain below flood stage. However some splash-over and beach erosion is likely and a coastal flood statement remains in effect. Similar conditions are possible Tue around high tide...so another statement may need to be issued. Beach surveys and Emergency Managers continue to indicate compromised dune systems along the coastline from our storms this past winter...which will limit natural protection. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...High Surf Advisory until 8 PM EDT this evening for MEZ023-024. NH...High Surf Advisory until 8 PM EDT this evening for NHZ014. MARINE...Small Craft Advisory until 8 PM EDT Tuesday for ANZ150-152>154. && $$ NEAR TERM...Legro SHORT TERM...Legro LONG TERM...Cempa AVIATION...Cempa/Legro MARINE...Cempa/Legro TIDES/COASTAL FLOODING...Legro