NWS Forecast Discussion
For Fremont, NH
000 FXUS61 KGYX 060006 AFDGYX Area Forecast Discussion National Weather Service Gray ME 706 PM EST Tue Dec 5 2023 .SYNOPSIS... Light snow showers possible tonight for the southern half of New Hampshire, then a drying and cooling trend progresses into Thursday as high pressure builds across New England. Temperatures moderate late week and into the weekend as the high moves offshore. A strong low pressure system moves through the Great Lakes Sunday night and Monday, with wind and some rain impacts increasingly likely during this timeframe. High pressure returns toward the middle of next week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 7 PM...Based on latest meso models and obs /especially radar/ it seems unlikely we`ll see any SHSN in S NH this evening, and even after midnight, what fall looks to be pretty isolated and light, so have backed off POPs some overnight. Also made a few adjustments to T/Td/Sky/Wind based on current obs, but nothing that affects the forecast in any appreciable way. Previously...Stubborn clouds continue to hold on this afternoon, but drier northerly flow is helping to break things up in our northern and western zones. Southern zones will see clouds thicken again this evening as a similar set up to last night occurs, with a 500 millibar trough digging in and interacting with an inverted surface trough nosing in from low pressure moving offshore from the Carolinas. Tonight it looks like the forcing for ascent will be more focused on southern New Hampshire, but similarly any snow looks very light with little to no accumulation. Temperatures up north, where clouds look to thin, fall into the teens and single digits and down south where clouds stick around, only cool to the 20s. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Clouds clear out from north to south as the trough exits and high pressure over Quebec noses in. They don`t clear out quick enough to get high temperatures much above the mid 30s south of the mountains and mid 20s to the north however. Clouds do clear out for the evening and overnight allowing temperatures to fall into the single digits up north again, and teens down to the coast. Clouds will begin to thicken again towards daybreak Thursday as a warm front approaches. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Overview... Broad high pressure gradually moves through during the later portions of the work week and into the early weekend. The high moves offshore through the weekend as low pressure develops across the south central US. This low deepens as it moves northeastward through the Great Lakes Sunday night through Monday. Broad high pressure then builds eastward into the Northeast going into the middle of next week. Details... A broad axis of high pressure crosses New England on Thursday through Friday. A seasonably cool day is expected for Thursday, with a moderating trend starting by Friday. Despite WAA beginning, lingering high pressure allows for decoupling and another night of radiational cooling Thursday night. This brings lows into the single digits and teens across the area. Typical radiational cooling spots with snow cover also have a shot at dipping below zero for one more night, but this forecast is already much lower than NBM guidance, without ignoring the chance that clouds could spoil the cooling potential. The center of the high moves offshore going into the weekend, continuing the warming trend. However, the main focus remains the developing low pressure center across the southern tier of the country. Low pressure develops across the south on Saturday, deepening as it moves northeastward into the Great Lakes through Sunday. The low continues to strengthen as it passes well to our west Sunday night through early Monday. There remains fairly high confidence in a mainly rain and wind potential for the area with system, but the degree of intensity remains in question. There has been a trend in the Euro the last few runs for the storm to take longer to develop as it moves northward, and a slight trend to track back farther east. The slower to develop trend has little impact on our outcome at this point as the low remains sufficiently strong by the time it reaches the Great Lakes, but it serves as a reminder that the details of the system and how organized it is by the time it reaches is not set yet. At this point the rainfall doesn`t look overly impressive, with most models putting out QPF between 0.5in to 1.5in. This would increase if we get into more of the stratiform shield, but there is little guidance supporting this at this time. The most potentially impactful factor looks to be wind gusts. How deep the low gets and how close it passes to our west remain the deciding factors of how strong the wind gusts will be. At a minimum gusty wind are expected along the coast, with the upper end range currently coming in below last December 23rd`s storm. So we will continue to monitor the trends over the next few days, but it is reasonable to expect that there will at least be some wind impacts Sunday night into Monday. High pressure and cooler air then spreads eastward toward the middle of next week. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... Short Term...VFR/MVFR ceilings prevail this evening, but New Hampshire terminals could see some light snow showers overnight that could bring about IFR visibilities. Conditions improve and remain mostly VFR across the area through Wednesday. Long Term...VFR conditions prevail through Saturday night, then ceilings gradually lower on Sunday as a storm approaches. IFR conditions with rain, and southerly wind gusts in excess of 30kts are likely Sunday night into Monday. Conditions improve Monday night, with mainly VFR expected by Tuesday. && .MARINE... Short Term...Snow showers are possible over the waters overnight tonight. Otherwise, winds and seas remain below SCA thresholds through Wednesday. Long Term...High pressure remains across the waters from Thursday into Saturday. A developing storm moves across the interior Northeast, with gale to storm force southerly winds possible Sunday night and Monday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ SYNOPSIS... NEAR TERM...Baron/Cempa SHORT TERM...Baron LONG TERM...Clair AVIATION... MARINE...