South Burlington, VT Weather

What Has Changed

As of 219 PM EDT Sunday...

No significant changes to the current forecast.

Key Messages

As of 219 PM EDT Sunday...

1. A weak, moisture starved, cold front will pass through the area tomorrow, with sharply colder temperatures heading towards mid week.

2. Moderating temperatures are expected late this week and next weekend with some brief rain possible Thursday night.

Discussion

As of 219 PM EDT Sunday...

KEY MESSAGE 1: High pressure today will begin to depart tonight into tomorrow evening with the approach of a weak, moisture starved cold front for tomorrow. GOES-19 visible satellite shows this front nicely with a narrow band of cloud cover stretched across the Michigan Upper Peninsula to west central Quebec. As the front moves into northern New York tomorrow morning, antecedent dry conditions at the surface will limit much if not all of the precipitation that will be associated with the boundary. Virga looks likely with dewpoint depressions of 5-10 degrees ahead of the front. A few places along the northwest facing slopes of the Adirondacks and northern Greens, including Jay Peak, may see a few sprinkles, but accumulations will be little to non-measureable. In the deeper valleys, we will likely not have enough time to saturate before dry air advects in behind the boundary cutting off any precipitation chances by tomorrow early afternoon. Winds will turn to the north- northwest as the front moves through advecting sharply colder air from Canada. Monday night lows will cool to the upper 20s for many locations with a few locations hovering around the freezing mark in the wider valleys. Tuesday will feature sunny skies with continued cool high temperatures struggling to reach the upper 40s. The coldest night of the season arrives Tuesday night under strong radiational cooling. Overnight lows may approach some records for Montpelier and St. Johnsbury, with records elsewhere residing in the 10th percentile or lower. Temperatures will drop to the teens across the Adirondacks and low 20s elsewhere. Temperatures slowly rebound Wednesday as high pressure and south winds help to moderate our flow pattern.

KEY MESSAGE 2: High pressure overhead will allow the air mass to slowly moderate Wednesday night into next weekend with highs climbing back into the upper 50s and 60s on Thursday and Friday. There is the potential for a few showers on Thursday night with another weak cold front, about 30-60% chance of rain outside of central and south- central Vermont, which have lower chances, closer to 10-40%. The forecast for Halloween trick-or-treating looks dry and seasonably mild under high pressure with afternoon temperatures in the upper 50s to mid 60s, falling into the lower and mid 50s in the evening.

Aviation

Through 18Z Monday...VFR conditions and light winds are expected to prevail through at least 15Z-17Z Monday as cloud coverage gradually increases and ceilings lower over the next 24 hours ahead of and during a frontal passage. Winds this afternoon are mainly out of the southwest 5-10 knots, except PBG, which has a southeasterly lake breeze, as well as MPV and RUT, which are reporting calm winds. Winds will shift out of the south in the Champlain Valley this evening, becoming southeast at RUT in their typical drainage wind 3-6 knots. Winds won't be especially breezy tonight, but they should remain steady enough at most sites to keep dense fog a low threat. A Monday morning rain shower is possible at MSS ahead of and along the front from 13Z-16Z, but otherwise dry conditions are anticipated at the TAF sites over the next 24 hours. Ceilings could wobble around the VFR-MVFR threshold towards 15Z-18Z Monday with the frontal passage, but this will likely be more of a brief TEMPO situation as we get closer. Winds will make a shift towards north-northwesterly as the front crosses the region.

Outlook...

Monday Night: VFR. NO SIG WX. Tuesday: VFR. NO SIG WX. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. Slight chance SHRA. Thursday Night: Mainly VFR, with local MVFR possible. Slight chance SHRA. Friday: Mainly VFR, with local MVFR possible. NO SIG WX.