Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 260048 AAB AFDGYX Area Forecast Discussion...UPDATED National Weather Service Gray ME 848 PM EDT MON JUL 25 2016 .SYNOPSIS... A cold front will cross the region tonight, providing another round of showers and possible thunderstorms. High pressure will build in from the west Tuesday through Wednesday. A weak frontal boundary will settle south from Canada Thursday and will stall just south of the region on Thursday and perhaps Friday. Areas of low pressure may travel along this front to our south over the weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 8:50 pm Update... Some increase in PoPs across the northern sections at this time as the next short wave approaches. This may keep isolated storms and scattered to widespread showers across the northern zones overnight...with only isolated to scattered showers expected after 2 am. Temperatures...dew points and weather grids were adjusted with fog and low stratus already forming. 750 pm Update... I have adjusted PoPs to come closer in line with current shower activity. Only a couple areas of consequence this evening with more widespread shower expected activity later tonight across the mountains. Have added drizzle to Rockland and points east for later tonight. No lightning has been observed so far in our region. Temperatures were adjusted a few degrees lower also based on mesomodels. Sky and mountain sky grids were also nudged to clear out somewhat quicker towards morning. We will see widespread fog tonight...especially in areas where it rained this evening. Previous discussion... A weakening area of showers continue to move east through NY and VT this afternoon and will start to affect western NH in the next hour or two. HRRR model seems to have a good handle on this weak disturbance...although slightly underdone. As this passes through the region isolated thunder is possible...although most areas will just see a brief shower as the main area of showers and thunderstorms passes south of the region. A second disturbance currently south of Lake Ontario is also forecast to pass mainly south of the region although it may clip southern areas. The short wave associated with this disturbance will pass through the area later this evening...prolonging the threat of mainly showers with possible thunderstorms. The showers should move east of the eastern section of area after midnight. Skies should begin to clear by morning with patchy fog developing as dew points remain high. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... The area should see partly sunny skies Tuesday as a ridge of high pressure builds into the area. A weak boundary north of the region will allow for only a slight chance of showers in the mountains Tuesday. Winds Tuesday will be offshore allowing temperatures to warm to the upper 80s to lower 90s from southern New Hampshire to much of the midcoast area of Maine. Dewpoints will remain in the 60s across the region so air will still feel a bit muggy. Overnight lows Tuesday night will drop to mid to upper 50s in mountains to the low to mid 60s southern and coastal areas with mostly clear skies. Patchy fog is again expected. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... A weak ridge of high pressure settles over the area Wednesday with dry conditions except maybe widely scattered convection restricted to the mountains. On Thursday a cold front moves through the region setting off showers and thunderstorms. The big concern will be whether a much needed rainfall develops over the weekend. Models differ significantly on handling of a developing low pressure system moving east from the plains and into the Ohio valley and Eastern Great Lakes toward the weekend. The EURO clearly brings system much further north with significant rain that would move into the region Saturday and through the weekend. The other models are much further south with the system and keep the rains to our south. For now will stick with the superblend guidance which is a hedge of presenting a chance of the rain across the entire area. It should be noted the confidence is low for the weekend forecast. Temperatures will remain mild through the period but may be cooler over the weekend. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... Short Term...MVFR to IFR conditions tonight in showers and fog after midnight. Drizzle is possible for RKD. VFR conditions Tuesday after any morning fog. Patchy fog possible again Tuesday night. Long Term...VFR conditions are expected Wednesday. A cold front crosses the area Thursday with MVFR conditions in scattered showers and thunderstorms. Mainly VFR conditions return Friday. An area of low pressure passing south of the area Saturday may lower conditions depending on the northern extent of the system. && .MARINE... Short Term...Winds and seas expected to be below SCA criteria through Tuesday night. Showers and thunderstorms and fog may limit visibility overnight tonight. Long Term...Conditions to remain below SCA criteria through the outlook period. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Hanes SHORT TERM...Jensenius LONG TERM...Marine is the U.S. government's official web portal to all federal, state and local government web resources and services.