Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
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172 FXUS61 KGYX 121402 AFDGYX Area Forecast Discussion National Weather Service Gray ME 1002 AM EDT Sun May 12 2024 .SYNOPSIS... Low pressure passes south of the region today, with another chance of afternoon showers. A more widespread period of showers and rain is likely beginning Monday night into Wednesday. Conditions dry out late in the week as New England sees a period between systems, and then may turn unsettled again by next weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 10 AM...There`s not too much going on for showers yet, but this increase for the rest of the morning. There`s a fair amount of sun in some areas of west and central ME, so convective showers more likely here, but possible anywhere this afternoon. 7am Update...Minor update to take the Frost Adv down and update some temp/sky trends. High cirrus has overtaken the area, and will likely linger for the day. Meanwhile, surface heating will promote the development of a lower deck of cu today. Previous Discussion... Plenty of high clouds today as low pressure skirts south of the area. Additional convergence should allow for more scattered showers today, with the greatest concentration over the mountains and foothills. These should then track into the interior and coast by late afternoon and the early evening hours. Instability today will still be capped by a temp inversion around 650mb, while it is deeper today than Sat, don`t expect much more impact from precip other than a downpour directly under the shower and maybe gusts around 25 mph. Graupel potential seems limited, and would be reliant on lifting assistance (perhaps along terrain or seabreeze boundary). HREF probabilities do pools the greatest amount of CAPE towards the ME capitol region. Despite another increase in diurnal cloud cover, temps push towards 60 today. With weak low level winds, expect seabreeze to make its way inland early this afternoon. This will keep cooler temps in the 50s for much of the immediate coast an inland a few miles. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... Showers dissipate through the evening. There should be less in the way of high and mid clouds tonight into Monday, with low cloud slowly dissipating from daytime convection. With light winds once again, this will bring the chance for more frost tonight amid some pockets of good radiational cooling. Fog may also form where daytime showers wet the surface. Monday will see mostly dry conditions, but showers will be moving towards the area come the afternoon. These may be starved of forcing and moisture, thus have kept slight chance PoPs through the afternoon. Monday will mark a step change in warmer temperatures, with highs pushing into the mid to upper 60s for much of the area despite increasing clouds. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Overview... Low pressure moves closer Monday night and Tuesday, spreading showers and rain into much of the area at times into at least Wednesday. The system moves away on Thursday, with a dry day looking most likely on Friday before another system moves toward the area on Saturday. Details... By Monday night and Tuesday, moisture drawn northward by southern low pressure begins to interact with a cold front associated with the Canadian low pressure system. Showers expand across northern and western areas Monday night and Tuesday, but likely won`t expand into southern and coastal areas until Tuesday night and into Wednesday as the front sags southward. The low passes well to the south on Wednesday, with the northern edge of the rainfall near or into southern forecast areas. Wednesday and Wednesday night are trickier forecasts, with the chance that the rain remains to our south most of the day. Rain looks more likely than not at this point, but it would only take a little more of a southward jog of this system to leave Wednesday mostly dry. However, if it does trend more northward, periods of showers or rain would likely linger into Thursday. With this slow moving pattern and multiple cut off low pressure systems, it looks likely to raining somewhere in our CWA for several days from Monday through Wednesday, but not everywhere at once. There are likely to be breaks in the rain and clouds, similar to what we`ve seen the last couple of days, but are difficult to time out at this point. Friday looks like the next chance for a mostly dry day as New England has its next best chance to be between systems. But then by next weekend, it looks like another cut off low will gradually spin northwestward, spreading moisture toward New England. High pressure across the Canadian Maritimes will attempt to thwart this system toward the southwest, but there are too many other low pressure systems to get through first before the details of this one become more clear. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... Short Term...VFR today, with SHRA across most interior ME terminals. Showers should stay north of southern NH TAF sites. Patchy fog will be possible tonight where these showers pass. VFR continues Monday, although ceilings will be lowering west to east as additional showers approach the area. Long Term...Showers likely accompany MVFR ceilings Monday night and Tuesday across northern and western terminals. These restrictions spread to the remaining terminals late Tuesday and Tuesday night. Showers and MVFR ceilings likely linger across coastal and southern terminals on Wednesday, with some improvement across northern and western terminals more likely. Conditions gradually improve toward VFR everywhere by Thursday, and linger through at least Friday night. && .MARINE... Short Term...Below SCA conditions as high pressure continues to drift overhead. Low pressure passes south of the waters today, with some showers nearing the coast this evening. More breezy SE winds arrive for Monday. Long Term...A slow moving low pressure system and cold front approach the waters Tuesday and Wednesday, with SCA conditions possible on Tuesday with southwesterly flow. This low passes south of the waters Wednesday and Thursday, with the front likely crossing slowly Wednesday and Wednesday night. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ SYNOPSIS... NEAR TERM...Cempa/Cornwell SHORT TERM...Cornwell LONG TERM...Clair AVIATION... MARINE...