NWS Forecast Discussion
For Fremont, NH
647 FXUS61 KGYX 191327 AFDGYX Area Forecast Discussion National Weather Service Gray ME 927 AM EDT Mon Aug 19 2019 .SYNOPSIS... A cold front will cross the region today and will be followed by high pressure building in from the west overnight. High pressure will crest over the region on Tuesday before shifting offshore to the southeast. A weak disturbance will push east through southern New England late Tuesday night and early Wednesday. Weak low pressure will slowly move northeast through southern Quebec Wednesday night and will drive a trailing cold front through the region after midnight. A secondary trough of low pressure will drop southeast through the region Thursday night and Friday. High pressure will gradually build in from the west over the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 925 AM Update...Some relatively minor adjustments to the forecast this morning based on latest trends in radar and satellite data as well as info from latest CAMs. Skies have cleared out across NH and this will allow the atmosphere to destabilize. An area of weakening showers will cross northern NH over the next couple of hours, but measurable is unlikely at most locations. Otherwise, low clouds and fog will continue to lift across central and Midcoast zones except for perhaps the immediate Midcoast where they should hang on longer. For this afternoon, latest mesoscale models continue to show a broken line of storms moving across the forecast area between 2 and 7 PM. Not all areas will get one, but strong gusty winds will be possible in the strongest cells. Previously... 700 AM Update... Warm front currently pushing through eastern zones with the remainder of last nights showers. Farther south...ocean stratus beginning to thin out across southeast New Hampshire and this trend will continue to the north and east into southern interior Maine through mid morning as boundary layer winds turn more southwesterly and mixing picks up. Have adjusted pops and wx based on latest radar trends and tweaked area temps/tds. No other changes planned attm. Prev Disc...Warm front currently lifting northeast through central Maine early this morning and expect associated showers to be exiting eastern zones by daybreak or shortly after. Another line of convection ahead of an approaching cold front currently moving through far western New York and the HRRR pretty much kills this activity off as it moves into western New England later this morning. Expect convection to redevelop early this afternoon as the front pushes into northwest New England. SPC has all of the forecast area in a marginal risk for today. Best shear will be found in northern zones this afternoon as daytime heating generates some moderate to strong CAPE. Would expect potential wind damage with stronger cells in northern zones as shear combines with PWAT`s of 1.5 inches or better, resulting in good precip loading in more organized lines or line segments. Farther south expect more scattered storms with the potential for heavy rain and damaging winds. Have highlighted the potential damaging winds and heavy rain in the zones. Mostly sunny skies this morning will quickly boost temperatures through the 80s to near 90 in far southern New Hampshire. Getting some marginal apparent temps of 95 to 97 in the Manchester/Nashua section of southern New Hampshire but impact should be minimal and brief so holding off on heat advisories at this time. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Cold front will quickly push east of the region this evening with any convection shifting east of the area through midnight. Expect clearing skies and light winds overnight with patchy valley fog in the usual spots. Lows overnight will range from the mid 50s north to the mid 60s south. Cooler and much drier air will move into the region on Tuesday as high pressure builds in from the west. Looking for mostly sunny skies and highs from the mid 70s north to the mid 80s south. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... A bit unsettled early in the long term but cooler and drier air will eventually arrive for the weekend. For Tuesday night a frontal system to the south of the forecast area will move back north with increasing chance of showers and thunderstorms through Wednesday night. Dewpoint temperatures will climb back to near 70 Wednesday afternoon. A cold front will move through the forecast area before Thursday. The timing on this front is a bit in question. The later in the day with frontal passage the greater the chance for afternoon thunderstorms. The ECMWF has the front moving through a bit later than the GFS. For now I have the higher POPS in the morning with a low chance POP in the afternoon. Still a warm day Thursday but dewpoint temperatures will be a bit more comfortable. The cooler and drier air sets in for Friday with dewpoints in the upper 40s to mid 50s. Showers possible in the mountains Friday afternoon. Saturday through Monday should be quite pleasant with high temperatures in the 70s and low humidity. && .AVIATION /14Z MONDAY THROUGH FRIDAY/... Short Term...IFR/LIFr ceilings and vsby in coastal and southern interior sections of Maine and New Hampshire this morning...improving to VFR this afternoon. VFR tonight and Tuesday. Long Term...Expect occasional MVFR/IFR in showers and thunderstorms Wednesday and Thursday. Friday possible MVFR in afternoon showers at HIE but VFR expected elsewhere. && .MARINE... Short Term...No flags. Long Term...SCA possible Wednesday and Thursday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM UPDATE...Ekster