Johnson, VT Weather

This Hazardous Weather Outlook is for northern New York, central Vermont, northeast Vermont, northwest Vermont and southern Vermont.

Day one

Today and tonight.

No hazardous weather is expected at this time.

Days two through seven

Wednesday through Monday.

No hazardous weather is expected at this time.

Spotter information statement

Spotter activation is not expected at this time.

What has changed

As of 224 PM EDT Tuesday:

Have increased the winds in the wider valleys of the region late Thursday and Friday ahead and associated with a cold frontal passage.

Key messages

As of 224 PM EDT Tuesday:

1. Cold winter like temperatures tonight will be followed by gradual warming towards the late week.

2. A cold front late Thursday into Friday will bring chances for light rain showers in addition to breezy to gusty winds.

3. Dry weather this weekend, shower chances return next week.

Discussion

As of 224 PM EDT Tuesday:

KEY MESSAGE 1: High pressure centered over the Southeast will continue to drive clear skies and cold northwest air into the region through tonight. With clear skies remaining into tonight, strong radiational cooling will take place with many locations seeing the coldest air of the season, with near record cold across portions of Vermont. Temperatures will fall to the low 20s for most of the region, outside of the higher terrain where a steep inversion will keep lows in the upper 20s to near 30. Near record cold at our climate sites including Montpelier, St. Johnsbury, and Plattsburgh will be possible tonight. A few high clouds late tonight look to limit the prime radiational cooling time tonight across much of northern New York, otherwise a few records there might also be in jeopardy.

Temperatures will gradually warm and trend to normal as high pressure shifts east offshore Wednesday turning winds to the south, advecting in warmer air. A glancing mid level trough will bring some cloudy skies through the area tomorrow, but surface-mid levels will be too dry to see any precipitation. Temperatures will be 5-10 degrees warmer tomorrow with highs in the low to mid 50s, with our cool spots near the International Border and the Northeast Kingdom.

KEY MESSAGE 2: By Thursday, southwest strong waa ushered in by a 45-55 knot 850 LLJ will warm temperatures steeply well into the 60s. Highs in the mid to upper 60s will be possible with areas in the St. Lawrence Valley nearing even 70. The warm temperatures will come at a price though, as southwest winds will increase to 20-30 MPH, particularly in the St. Lawrence and Champlain Valleys. Model soundings continue to trend up with top of the mixed layer in the recent model suite averaging around 35 MPH. Mixing of these stronger winds will be complex as the timing of the precipitation associated with the cold front will be entering the region around the time of peak mixing, which could temper gusts slightly lower. Regardless, Thursday afternoon in the St. Lawrence Valley and near Lake Champlain will be gusty. Precipitation will generally be scattered with the front due to lingering dry air at the surface, though moisture advection with this system will be better than our system Monday. A few hundreths up to a tenth of an inch or rainfall is expected, focused in the St. Lawrence Valley, Adirondacks, and northern Greens. A few showers will linger into Friday along the northern mountains, but we will begin to trend drier by Friday afternoon. Winds will turn to the west northwest behind the front which will bring drier and cooler air by Friday afternoon. Lapse rates will steepen Friday afternoon as we dry out with good vertical mixing across our northern wider valleys. Winds will increase with better chances for seeing some stronger winds up to 30 MPH. Have trended winds up as confidence grows for these stronger channeled winds Friday afternoon.

KEY MESSAGE 3: Surface high pressure builds over our region for the weekend bringing dry weather and temperatures slightly warmer than seasonal normals for daytime highs, and cooler than normal overnight minimum temperatures. Sunday night into early next week high pressure moves east of our region and will have some shower chances next week, though lots of uncertainty at this stage.

Aviation

Through 00Z Thursday: There will be minimal weather concerns to aviators for this forecast period with the region under high pressure. Light winds expected overnight becoming light out of the south after 12Z with CIGS over 8000ft moving in. There could be some light virga from this deck at times, but the sub-cloud layer is dry and any liquid is unlikely to reach the ground.

Outlook:

Wednesday Night: VFR. NO SIG WX. Thursday: VFR. Chance SHRA. Thursday Night: Mainly VFR, with local MVFR possible. Chance SHRA. Friday: Mainly VFR, with local MVFR possible. Slight chance SHRA. Friday Night: VFR. NO SIG WX. Saturday: Mainly VFR, with local MVFR possible. NO SIG WX. Saturday Night: VFR. NO SIG WX. Sunday: VFR. NO SIG WX.

Climate

A couple daily record lows are possible for October 28th. Below is the current record and the current forecast as of 230 PM October 27th.

October 28: KMPV: 20/1974 - Forecast 21F KPBG: 21/1999 - Forecast 25F K1V4: 22/1999 - Forecast 19F

Equipment

Routine observations from KSLK ASOS are unavailable until further notice. While the site is operating, it is not able to disseminate observations normally at this time. Technicians are aware of the issue, but time of return to service is unknown.

Watches, warnings and advisories

VT: None. NY: None.