textproduct: Burlington

SYNOPSIS

High pressure will make for a beautiful Sunday and Labor Day with dry weather and warming afternoon temperatures. A few showers will be possible Tuesday, mainly over the higher terrain, but our next best chance of widespread rain doesn't arrive until late in the week.

NEAR TERM /THROUGH TONIGHT/

As of 208 AM EDT Sunday...High pressure will settle across our region today and tonight, bringing ideal late summer weather. This morning's patchy fog and lingering low clouds will dissipate by early afternoon, leaving behind ample sunshine and just a few passing clouds. Highs will be warmer than yesterday but still a little cooler than normal, with most locations topping out in the low to mid 70s. This will give way to another chilly night tonight as lows once again dip down into the mid 40s to low 50s. Wouldn't be surprised to see a few of the usual sheltered spots in the Adirondacks and Northeast Kingdom flirting with the 30s by early Monday morning. Patchy valley fog is expected to develop overnight and linger into the early morning hours.

SHORT TERM /MONDAY THROUGH TUESDAY/

As of 208 AM EDT Sunday...Labor Day will start off sunny with some patchy valley fog, which should gradually dissipate after sunrise. Cloud cover will increase through the day, though expect it should remain fairly thin and allow at least some sun to break through. Even with clouds, expect another day of heating will allow highs to warm close to normal, generally topping out in the mid 70s to around 80F. Radiational cooling won't be quite as optimal Monday night as what we'll see tonight; east flow will bring in a bit of marine air, which may result in some overnight stratus. Still, expect another pleasant night with lows in the upper 40s to mid 50s.

High pressure will continue to dominate at the surface on Tuesday, but a weak upper low and associated cold pool will drift northward across western New England and New York during the daylight hours. Forcing will be weak and CAPE minimal at 500 J/kg or less. Still, moisture should increase just enough to allow scattered showers to develop, particularly over the higher terrain owing to orographic effects. A few rumbles of thunder are even possible, but any thunderstorms should remain isolated in nature. Highs will be similar to Monday, in the mid 70s to around 80F.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/

As of 208 AM EDT Sunday...A weak upper low will break down Tuesday night with some lingering light showers along the international border. Surface high pressure will build back in for mid week as a shortwave ridge builds in with dry air ahead of a warm front. Wednesday will be seasonable and mainly sunny with highs in the upper 70s to low 80s. In general, temperatures mid to late week will generally be seasonable with our average high this time of year in the upper 70s. Clouds will build in Wednesday night as a high amplitude upper low swings out of the Great Lakes.

Probabilistic guidance across all ensembles progs a strong upper low developing across the northern Great Lakes with normalized height anomalies of 3 sigmas below average at 500mb. Portions of the midwest may be under the 540 height line, which typically serves a general basis for snow potential in the winter. This height anomaly will lead to strong meridional flow across the east coast which will efficiently advect moisture along a cold front by the end of the week. While confidence in the presence of the upper low is high, ensembles spread on the exact timing of the moisture corridor in our region is wide. Models tend to move these features through too fast so initial thoughts would be a precipitation onset closer to Thursday night into Friday morning. However, some earlier ensemble solutions show the onset as early as Wednesday night. There does not appear to be any large scale blocking ahead of the system, which could lean into a potentially faster system, however, models do hint at a weak coastal low developing Thursday in the Mid-Atlantic, which could slow the propagation of the trough. All in all, we need the rain, and by the end of the week, this system has a good chance at providing some wetting rainfall for a large majority of the region. Ensemble estimates of precipitation show about a 40-60% probability of greater than 0.5" between the raw MOS and NBM. Precipitation should linger into next weekend as the center of the upper low draws closer and a few shortwaves eject downstream. Temperatures will become seasonably cool as well as the system approaches from the west.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

Through 12Z Monday...Overnight valley fog will dissipate within an hour or so between 12Z and 13Z at SLK/MPV/EFK. All terminals will trend towards VFR for the remainder of the day beyond 13Z. High confidence in calm and quiet conditions prevailing through at least the next 12 hours at all terminals. Winds will shift from variable and southerly to more north to northeasterly at 5 to 10 knots as surface high pressure builds in today. Clearing skies, and weak to calm winds tonight will set up for good radiative fog development. Using last night as persistence, given little change to the flow pattern, less cloud cover, and similar cooling levels, fog is anticipated to develop at least at SLK/EFK/MPV overnight tonight.

Outlook...

Labor Day: VFR. NO SIG WX. Monday Night: VFR. NO SIG WX. Tuesday: VFR. Slight chance SHRA, Slight chance TSRA. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. NO SIG WX. Wednesday Night: VFR. NO SIG WX. Thursday: VFR. Chance SHRA.

BTV WATCHES/WARNINGS/ADVISORIES

VT...None. NY...None.