These details are provided by the NWS offices in Gray Maine, and the surrounding NWS offices in New York, and Massachusetts.  I have modified some of the technical stuff to help make it more understandable for the average reader.

Last update: 8/18 - 6:55 AM

NEAR TERM /UNTIL 6 PM THIS EVENING:
Low pressure will undergo a general broadening and weakening trend through today as it pivots over ME and tracks NE towards the Canadian Maritimes through tonight.

Rainfall this morning has been overachieving in some locations early. Since midnight, rainfall axis has shifted northwest a bit, with greater rain coverage for the mountains and foothills of NH. A small mesolow feature also developed in south central NH over Concord with some enhanced precip amts. This isn`t unwelcome considering how dry it has been in the area, but perhaps a bit west of earlier forecast thoughts.

For today, much of the remaining low cloud and rain will fall in the mountains and western forecast area. West winds increase, gusty at times this afternoon. Some gusts to 30 mph will be possible in southern NH as rain pivots out of the area. Some showers will be possible outside of the mountains, tapering in the evening.

Temps will be warmer for locations outside of the mountains. It will feel pretty raw in the higher terrain w/ clouds inhibiting much sun warming and a brisk NW wind. Wind chills may fall below freezing in the highest elevations of the Whites today.


SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY:
Friday flips the switch back to summer as temps rebound into the lower to mid 80s in the south, and upper 70s to low 80s elsewhere.

Sunny, dry conditions are expected, with lowering relative humidity values. Will keep an eye on final rain totals for far southern NH after the midweek system, as breezy conditions and the low RH could present fav fire weather conditions.

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY:
Large scale 500mb pattern over eastern CONUS for much of the long term. With surface high pressure along the western Atlantic, expecting a warmup for the weekend with limited opportunities for precipitation. Looking at nearly consistent H850 temps between 11 and 14C through the extended, supporting highs in the lower to mid 80s outside of the mountains. Southwesterly flow predominant at the surface, but generally light and favorable for marine intrusion most days.

A slow moving mid level low over the Great Lakes region will weaken as it drifts eastward early next week. As it inches closer, the local area can expect an increase in moist southwesterly flow. Models differ on the positioning of this feature, but the trend favors it filling in Tuesday timeframe without ever seeing a notable airmass change. However, the increasing moisture and embedded weak disturbances could bring changes for scattered showers and thunderstorms mainly Monday and Tuesday afternoons, though low confidence in coverage as they`ll be conditional on the timing of any shortwave energy.

The trough will continue to fill in mid to late week, but can`t rule out some spokes of shortwave energy keeping at least isolated/scattered probability of precipitation chances in forecast, however the overall trend is most areas will miss out on rain. Heat and humidity will be above seasonable normals until the trough axis pushes east and we finally get cooler/drier air to filter in. Some models are indicating a transition as early as Thursday, but the GFS and ECMWF are more conservative and don`t show any transition in the 7 day period. Starting to see some slight seasonal shifting in the ridge equatorward, and while this will allow for some cooler air to work down behind any waves that cross the top of the ridge, there is little in the way of unseasonable cold air to our north to tap into so the trend will favor normal to above normal temperatures. Have bumped up temps in the extended a degree or two from guidance based on these factors.