National Weather Service (2024)

Area Forecast Discussion
Issued by NWS Portland, ME

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-- Discussion containing changed information from previous version are highlighted. --236FXUS61 KGYX 031903AFDGYXArea Forecast DiscussionNational Weather Service Gray ME303 PM EDT Wed Jul 3 2024.SYNOPSIS...
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A weak warm front will approach tonight allowing a few lightshowers, mainly well after midnight. A brief shower or two willremain possible on Independence Day, but the vast majority ofthe day will be dry. Higher temperatures and humidity begin tobuild on Independence Day with this trend continuing through theend of the week. The next chance for more widespread showersand thunderstorms is expected this weekend.
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A relatively warm night is expected tonight as the WAA patterncontinues in advance of a weak warm front. Forcing for ascentshould increase and become sufficient for a few showers to moveinto western zones and mountains late. Went with moderate chancePoPs for measurable.
-- End Changed Discussion --&&.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
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Warm front works through the region in the morning with thoselight showers dissipating. A warm and more humid air mass willbe felt in the wake of this front, but mostly cloudy skies willpersist, allowing for a slightly cooler day than today. A weakcold front sags southward across the forecast area during thelate morning and afternoon hours. Forcing for ascent will beweak at best, but with humid airmass in place amidst fallingheights, we cannot rule out an isolated shower or thunderstormduring the afternoon.
-- End Changed Discussion --&&.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
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Overview: An active weather pattern taking shape late this weekinto the weekend. Low pressure is forecast to track from theGreat Lakes into eastern Quebec Friday and Saturday. This willbring the chance for showers Friday, and again Saturday with theadded potential for thunderstorms and heavy rain. Someuncertainty how quickly this system pulls east for dryingSunday, but high pressure following the system should beoverhead by Monday. Another period of unsettled weather may bein the region by the middle of next week, perhaps with morepotential to linger than this weekends system.Details: Continued warmth Friday as weather pattern becomesbusy. The day may be punctuated by some afternoon showers andthunderstorms developing across the interior. With weak shearand marginal CAPE, currently see these as just providing anisolated afternoon downpour with not much threat of hail/wind.High pressure to the north will continue moving NE as lowpressure moves across the Great Lakes Friday and into QuebecSaturday. Warm sector moisture keeps Saturday humid and damp.Saturday likely sees the best chance for rain during the day,with some thunder potential. Some guidance is robust with warmlayer aloft and CAPE suffers especially surface basedinstability. The window for instability may be open a bit moretowards western NH, where a stronger storm cant be ruled outgiven the strong shear and moist environment. At this pointhowever, the risk for heavy rain may be a larger but still mutedaspect. CWA PWATs push 2 inches Saturday with much of thecolumn saturated between early morning and early afternoon.Additionally, the aforementioned warm air aloft keeps warm cloudlayers deep, around 13-14kft. So precip efficiency is there,but the setup lacks favorable storm motion and features dryantecedent conditions. Wed really need training storms Sat(possible were CAPE to improve) and impactful shower activity onFriday to increase odds of flooding Sat. One possibility is ifthe following cold front slows, focusing rainfall along its axisovernight into early Sunday morning, but best push ofefficiency parameters may be pulling east by then.Sunday features less in the way of rainfall, but cant rule outa few showers for the first half of the day. High pressurenears the Northeast into early next week, providing a break ofthe dreary weather Monday. This high will play a key role as itexits the East Coast into Tuesday and Wednesday. Restrengtheninghigh pressure in the open Atlantic could allow for a focus ofunsettled weather to remain in the region mid week through lateweek. A channel of moisture appears to get blocked and may alignwith a good portion of New England and the East Coast as awhole.
-- End Changed Discussion --&&.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
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Short Term...VFR conditions today and tonight. A few patches ofvalley fog possible tonight but coverage would be sparse. A fewwidely scattered showers late tonight into Thursday could bringa period of lowered conditions but overall, VFR conditions areexpected through Thu. A more moist airmass in place Thursdaynight may yield greater chances for fog, especially at KHIE,KLEB, KRKD.Long Term...Mainly VFR Friday, but ceilings will begin to lowerin the evening and overnight hours. Many terminals will likelysee IFR to LIFR ceilings along with some reduced vis due to fog.IFR lingers for mostly western ME terminals Saturday as SHRA andsome TS develop. A return to VFR may not be likely until Sundaywhen high pressure moves towards the region.
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Short Term...A few southerly gusts may approach 25 kt thisevening but sub-sca conditions are expected tonight throughThursday night.Long Term...The waters will spend much of the weekend within awarm sector of passing low pressure to the west. This willresult in periods of fog or low stratus over the coastal waters.Conditions may improve Sunday into Monday as a cold front slowlymoves over the waters. Onshore winds are expected throughSaturday, becoming SW Sunday and then W Monday.
-- End Changed Discussion --&&.GYX WATCHES/WARNINGS/ADVISORIES...ME...None.NH...None.MARINE...None.&&$$NEAR TERM...EksterSHORT TERM...EksterLONG TERM...Cornwell