Mount Holly, VT Weather

What Has Changed

As of 305 PM EDT Thursday...

No significant changes have been made.

Key Messages

As of 305 PM EDT Thursday...

1. Localized gusty north winds this evening will taper off, then dry and seasonable weather with a warming trend will follow through the weekend.

2. Quiet and dry weather is expected to continue into early next week.

Discussion

As of 305 PM EDT Thursday...

KEY MESSAGE 1: Sensible weather will continue to be quite agreeable for outdoor activities. Aside from a ribbon of clouds moving through from north to south this evening, a return to sunny days is expected as high pressure slowly builds in through the weekend. Main impacts for this period will be related to winds this evening on Lake Champlain, and then possible fire weather concerns over the weekend with critically low relative humidity values likely in parts of the region.

A moisture-starved cold front passed through the region today, detached from a ribbon of higher moisture behind it. Satellite imagery shows this cloud cover is tied to a corridor of higher relative humidity in the 925-850 millibar layer, with the air mass above that layer very dry. Hence, north of this region there are just some diurnally driven clouds and we can expect skies in our region to trend clear overnight.

A period of relatively fast pressure rises this evening is expected with accelerated northerly flow through the Champlain Valley as skies clear out again. Roughly between 7 PM and 10 PM we expect the strongest northerly winds in the 20 to 30 knot range on Lake Champlain with similar gusts in the eastern Champlain Valley. Northerly, rather than a more common northwesterly, flow will continue into Friday with a general decay of wind speeds as high pressure builds in.

The lightening wind will lead to a chilly night and have leaned towards colder guidance. At perennial cool spot SLK/Adirondack Regional Airport, a daily minimum temperature is possible (14 degrees). Any passing high clouds should have little affect on surface temperatures during the period. Also, as temperatures moderate aloft, both Saturday and Sunday will feature the return of the typical cold season surface inversion with mountain summits relative mild. Generally Sunday morning looks a bit less cold than Saturday morning as light south winds will interfere with the nocturnal boundary layer.

Forecast soundings through the next three days show very dry air aloft and correspondingly anomalously low precipitable water. While localized low humidity is expected tomorrow, cool northerly advection doesn't favor particularly low surface humidity at the surface. Dew points in the 20s are expected over the next couple of days, and with milder temperatures on Saturday reaching the upper 50s in most locations, this is the day when most locations will likely see their lowest relative humidities. Slight improvement on Sunday is expected with regards to fire weather concerns as some modest moisture advection occurs. Light winds through the weekend should minimize fire spread, however.

Aviation

Through 00Z Saturday...Cloud cover is slowly thinning now that a cold front has shifted south of the region. The layer exists between 4000-7000 ft agl, and will dissipate over the coming 6-9 hours. North winds will remain 5-10 knots for locations unsheltered from winds out of the north, but a few areas like KRUT and KSLK should transition towards light and variable conditions. Flow aloft is somewhat fast, and there could be localized regions that meet LLWS criteria during the next 6 hours, but are not shown explicitly for any terminals. This could also prevent fog from developing, though a brief reduction in visibility towards sunrise is not impossible.

Outlook...

Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX. Saturday Night: VFR. NO SIG WX. Sunday: VFR. NO SIG WX. Sunday Night: VFR. NO SIG WX. Monday: Mainly VFR, with local MVFR possible. NO SIG WX. Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX.