Area Forecast Discussion
Issued by NWS Portland, ME
Issued by NWS Portland, ME
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336 FXUS61 KGYX 011823 AFDGYX Area Forecast Discussion National Weather Service Gray ME 223 PM EDT Mon Jul 1 2024 .SYNOPSIS... High pressure will build over the region on Tuesday...moving southeast of the New England coast on Wednesday with warm and dry conditions as a result. A shower is possible as a weak frontal boundary crosses the region late Wednesday night. Temperatures and humidity begin to build on Independence Day with this trend continuing through the end of the week. The next chance for more widespread showers and thunderstorms is expected this weekend. && .NEAR TERM /TONIGHT/... A cooler air mass will move in from the west tonight as high pressure builds on from the Great Lakes region. Any diurnal boundary layer CU and isolated showers/tstm will dissipate around sunset with the loss of heating. Winds will diminish overnight which will allow for radiational cooling at many locations. Went with a blend of the MET and MAV guidance for mins tonight, yielding coldest values in the L-M 40s in the lower elevations of Coos County NH. Some valley fog is possible && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... High pressure dominates Tuesday highs mainly in the 80s. A seabreeze is expected to develop in the early afternoon. A fair and cool night appears to be in store for Tuesday night with high pressure nearby. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... High Impact Weather Potential: * Heat indices have some potential for nearing advisory thresholds by this weekend. * Greatest chance for thunderstorms also comes this weekend...with confidence currently low on any severe potential. The details...The cool and dry weather felt in the early part of the work week will change to more warm and humid conditions for the later part of the work week into the weekend. By late Wednesday the upper level ridge that has been with us will get pushed out as an upper level trough dives southward entering the area by Thursday. As this happens surface high pressure will slide offshore and a warm front will pull in the warmer and more humid air into the area late Wednesday. Some showers are likely late Wednesday into Thursday but widespread rain is not expected with thunderstorm activity unlikely given the timing of the front. The warm and humid July airmass continues Friday into the weekend with the next best chance for precip being Saturday into Sunday as low pressure to our west pushes a warm/occluded front through the area with the potential for some showers and thunderstorms. Will have to watch heat indices Thursday and beyond as well as temperature aloft would support near advisory level values in some spots if enough sun can be realized during this period. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Short Term...VFR tonight through Tuesday night with patchy valley fog late at night. Seabreeze develops Wednesday afternoon at the coast. Long Term...Generally good aviation conditions through the long term forecast period. A few showers are possible late Wednesday night / early Thursday morning with isolated restrictions. Building humidity may result in morning haze/fog at BML/HIE by Friday/Saturday mornings. && .MARINE... Short Term...Conditions remain below SCA thresholds on all waters through Wednesday. Long Term...High pressure will be located over the waters on Wednesday before a weak cold front stalls over the waters Wednesday night and Thursday. This front will lift back north of the waters on Saturday. The result will be an extended period of relatively light winds/low wave heights. From Thursday onward...increasing moisture may bring some fog over the waters. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Ekster SHORT TERM...Ekster LONG TERM...Doughty/Arnott