textproduct: Burlington

WHAT HAS CHANGED

As of 219 PM EDT Sunday...

No significant changes were made to the forecast. We will continue to monitor conditions Monday afternoon and evening for the potential for stronger storms and locally heavy rain.

KEY MESSAGES

As of 219 PM EDT Sunday...

1. Drier conditions continue this afternoon through early Monday, then showers and thunderstorms return Monday afternoon through early Tuesday as a weak front moves across the region. Another dry period is likely Tuesday afternoon into Wednesday.

2. Wet end to the week but drier weather expected next weekend.

DISCUSSION

As of 219 PM EDT Sunday...

KEY MESSAGE 1: A weak cold front has moved to our south and east, ushering in drier conditions to northern New York and Vermont that will last into Monday. Aloft, wildfire smoke is flowing into the region as well, though it looks like it should stay at high elevations and not descend to the surface. Highs today and Monday will be warmer than seasonal normals for early to mid August, with afternoon temperatures hitting the mid 70s to 80s each day. High pressure will be in control tonight, producing favorable conditions for radiational fog in the typical valley locations, mainly across Vermont, as lows fall into the 50s to mid 60s. A warm front is expected to lift through the region Monday afternoon, increasing chances of precipitation again into the 60-90% range for most areas outside the Connecticut River Valley. Strong storms are not out of the question Monday afternoon as high resolution models indicate around 1000 J/kg surface CAPE and 40 knots bulk shear available. The potential for severe storms may come down to the timing of frontal boundaries in our region aligning or not aligning with best instability and shear. Highest instability is expected in southern portions of our forecast area, including the central Adirondacks, southern Champlain Valley, and southern/south- central Vermont. Meanwhile, highest shear is anticipated across the Champlain Valley and portions of Vermont in the afternoon, resulting in an area of overlap between these two. A surge of moisture with precipitable water values 1.50-1.75" could also result in heavy downpours in any showers or thunderstorms across the region. Widespread showers and storms will linger into Monday night as another weak cold front moves through and temperatures fall into the 50s to mid 60s again. Another dry period is likely Tuesday afternoon through Wednesday as drier air filters in behind this second cold front. Highs in the 70s and lower 80s both Tuesday and Wednesday will be much closer to seasonal averages than we've seen of late, and relative humidity values will also decrease to more comfortable levels toward the midweek.

KEY MESSAGE 2: Deterministic guidance continues to be in good agreement that a strong mid-level shortwave and associated jet streak will help to amplify a longwave trough across the Northeast on Thursday and Friday. The GFS, ECMWF, and CMC are all in good agreement in the general evolution on the longwave pattern but still differ slightly on the exact timing when precipitation will return to the North Country. The general consensus, supported by the NBM, shows rain chances ramping up quickly during the pre-dawn hours on Thursday with widespread rainfall expected across the upper level trough swings through Thursday afternoon. A seasonably strong cold front will push through, likely behind the mid-level trough passage which is expected to bring below normal temperatures and drier weather to the region for Friday and much of the upcoming weekend. Deep layer ridging is expected to develop by Saturday which should bring plenty of sunshine with highs in the 70s, light winds, and dewpoints in the 40s to lower 50s.

There is also the potential for a few strong to possibly severe storms Thursday if we can get out of the "junky" clouds and rain in the morning. Models do suggest some strong convergence associated with the frontal boundary but the big question will be whether or not we can destabilize. Right now, it doesn't look promising for stronger storms but the AI and machine learning algorithms are giving us around a 10-15 percent chance for at least one report of severe weather. It'll be something to watch in the coming days but nothing to be concerned about at this time.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Through 18Z Monday...VFR conditions will continue through the TAF periods for most sites with the exception of KMPV and KEFK where periods of MVFR, IFR, and VLIFR fog are expected overnight tonight. Given the trends from this morning, it likely won't be until 13Z that fog is finally able to mix out with VFR conditions returning at these sites thereafter. Winds will be gusty at times out of the west with gusts likely no higher than 20 knots with winds going calm/light and variable overnight. Winds will shift to the south after daybreak tomorrow with some 10-15 knots winds possible through the day on Monday.

Outlook...

Monday Night: VFR. Chance SHRA, Chance TSRA. Tuesday: VFR. Slight chance SHRA. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. Chance SHRA, Slight chance TSRA. Wednesday Night: Mainly VFR, with local IFR possible. Chance SHRA, Slight chance TSRA. Thursday: VFR/MVFR conditions possible. Likely SHRA, Chance TSRA. Thursday Night: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Friday: VFR. Slight chance SHRA.

BTV WATCHES/WARNINGS/ADVISORIES

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