Johnson, VT Weather

What Has Changed

As of 316 AM EDT Tuesday...

No significant changes to the current forecast.

Key Messages

As of 316 AM EDT Tuesday...

1. High pressure will keep conditions dry with seasonable temperatures through late week.

2. The extended forecast continues to be very quiet with seasonable temperatures and dry conditions prevail through next weekend.

Discussion

As of 316 AM EDT Tuesday...

KEY MESSAGE 1: The broad surface high pressure centered over southern Ontario today will gradually shift eastward through the end of the week. An anomalously dry air mass and subsidence under the ridging will keep skies mainly clear despite a weak front sinking southward this morning. By this afternoon, northerly flow will increase slightly, and temperatures will top out in the upper 50s to low 60s. Tonight will be an ideal radiational cooling night, with the dry air mass remaining overhead and winds becoming near calm toward sunrise. Lows will range from the low to mid 20s in sheltered mountain valleys to the low 30s elsewhere.

The quiet stretch of weather will continue Wednesday through Thursday, with highs again forecast in the 50s to low 60s and lows in the 20s to 30s. A weak boundary will move through Thursday, but given the dry air in place, the impacts of the frontal passage will be minimal. A few sprinkles may materialize, followed by increasing northerly flow behind the front that will bring in a cooler air mass to close out the work week. Breezy north winds can be expected Thursday through Friday morning, especially channeled down the Champlain Valley and over mountain tops. High temperatures Friday will be a few degrees cooler than the previous days, ranging from the mid 40s to low 50s.

KEY MESSAGE 2: A 1034mb high pres wl be building into our region from central Canada late Friday into the upcoming weekend. This wl produce a dry and cool northerly flow behind our weak cold frnt for Friday night into Saturday. Progged 850mb temps drop btwn -1C and - 3C but start to modify quickly by Saturday. The building mid/upper lvl ridge and associated subsidence wl result in plenty of sunshine this weekend with near seasonable temps. Expect a large diurnal swing from cool night lows in the mid 20s to mid 30s to daily highs in the mid 50s to lower 60s. Progged PW values are btwn 0.15 and 0.25", indicating how dry the atmospheric column wl be this upcoming weekend. The mid/upper lvl ridge slowly breaks down by next Tuesday with approaching weak sfc boundary and a slight increase in moisture profiles. Did note the latest WPC grids has 10-20% pops for this time frame. In addition, some increase southerly flow ahead of approaching boundary is possible, which could increase fire weather concerns early next week, given recent dry spell.

Aviation

Through 12Z Wednesday...VFR conditions prevail today as surface high pres builds into our region from central Canada. Early morning Fog Product is showing a pocket of fog near MPV, which may impact this taf site with brief IFR thru 13z this morning. The highest probability of additional fog/mist with IFR conditions tonight will be at EFK/MPV after 08z. Still some uncertainty on areal coverage due to very dry air near the surface, but winds aloft will be much lighter.

Outlook...

Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. NO SIG WX. Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX.