Area Forecast Discussion
Issued by NWS Portland, ME

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000 FXUS61 KGYX 201352 AFDGYX Area Forecast Discussion National Weather Service Gray ME 952 AM EDT Wed Sep 20 2017 .SYNOPSIS... Jose will pass south and east of Cape Cod today and tonight, and could produce some scattered showers today and gusty winds along the coast into Thursday. Otherwise high pressure will be the main feature and stay in place across the region into early next week, with temperatures running above normal through the period, and mainly clear skies Thursday through Monday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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945 am Update: Low clouds/stratus continue across most of the area except over northern NH and the western mountains of ME where drier air mass has worked into the area producing partly sunny conditions. Light north winds will continue to drag drier air from the north into southern areas by later in the afternoon and tonight so some clearing will slowly take place from north to south. Keeping low pops along the immediate coast but expecting the light showers offshore to stay there. Only minor adjustments to temps based on latest mesonet data. 8 am Update: With north winds and enough mixing occurring, have taken out mention of fog for the morning although low stratus will persist. 640 AM...For the most part forecast is unchanged, as we look for winds to increase from the NNE this morning, and becoming breezy by this afternoon with some gusts nearing 30 mph on the coast. Showers in the outer bands of Jose continue to struggle to survive much past the coast as they run into the ridge and lose forcing as well as encountering drying air. Previously...As the center of Jose passes S and E of Cape Cod today, it will also begin to exhibit some effects of a brief extratropical transition as it gets tugged on by a trough passing well to the N. this should help expand its wind field a bit starting today, and will see winds increase during the day, with some gusts of 25-30 mph possible on the coast late today. Showers associated with Jose outer bands are working N-NW onshore but continue to struggle as the run into the strong ridging. Some clearing is possible this afternoon, mainly in the north and in the CT valley N of KLEB, but otherwise it will be mainly cloudy. Highs will range from the upper 60s to the mid 70s, warmest in the CT valley.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... Jose will begin to slow its eastward progression tonight and eventually become nearly stationary south of the Gulf of ME late Thursday. The combination of Jose lingering and sfc ridging building to our north will help maintain a strong pres gradient and allow breezy conditions to continue overnight into Thursday. In fact, may see the strongest winds on Thu as flow shifts more NNW and mixing improves in CAA, albeit weak CAA, and from the mechanical effects of downsloping. As for any additional SHRA from Jose, it looks like any chc of precip will be done by this evening, so mainly dry after that. Clouds should begin to erode from N-S overnight, with mainly sunny conditions on Thu. Lows tonight will stay mild, with the wind keeping up and keeping the atmosphere mixed, with lows in the mid 50s N to low 60s in the S. Highs on Thu will be aided by the strong downslope and should work to counteract whatever weak CAA exists, with highs mostly in the 70s, and approaching 80 in the CT valley. Also have extended the Heavy surf advisory along the coast through tonight at least, when coastal directed swell looks to be at its greatest. May need to push this into thu, but will let the day shift look at it. && .LONG TERM /FRIDAY THROUGH TUESDAY/... The models are in decent agreement on the long wave pattern through the upcoming weekend. We begin the period with an upper ridge across northern New England and the remnants of Jose meandering well offshore to our south and east. The ridge will continue to strengthen as we head into the weekend at which time the remnants of Jose will be kicked well offshore. The eastern ridge and western trough will hold across the CONUS through the start of the new work week with predominantly dry weather and abnormally warm temperatures to continue. By mid week...hurricane Maria may be lurking off the eastern seaboard similar to the current tropical system Jose. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... Short Term...Coastal terminals should see only very limited improvement to IFR for a few hours today, but may slip down to LIFR this evening, despite N winds gusting to 20-25 kts at times. Inland terminals will see better improvement this afternoon. All terminals should begin to improve late tonight as drier air working in on those gusty winds, with VFR expected everywhere by sunrise Thu. The gusty winds will continue through Thu. Long Term... Fri...NE sfc wind gusting to 25 kt psb at coastal TAF sites. && .MARINE... Short Term...8 am Update: Have dropped the Gale warning to a SCA over the southern waters for today as current conditions and guidance all point to winds not exceeding SCA conditions. Holding onto SCA for now across the rest of the waters. Seas will peak tonight and generally in the 7-11 ft range outside of the bays. Long Term... Fri...Small Craft seas and wind gusts are probable outside the bays. Sat - Sun...lingering Small Craft seas are likely outside the bays. && .TIDES/COASTAL FLOODING... Long period swells will continue through tonight. High tide at Portland is 10.6 ft around midnight, and conditions may be a little worse tonight given slightly greater swell, and possibly leading to minor splash over and some beach erosion. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...High Surf Advisory until 8 AM EDT Thursday for MEZ023>028. NH...High Surf Advisory until 8 AM EDT Thursday for NHZ014. MARINE...Small Craft Advisory until 5 PM EDT Thursday for ANZ150>154. && $$ NEAR TERM...Marine SHORT TERM...Marine LONG TERM...Ekster

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