textproduct: Burlington

WHAT HAS CHANGED

As of 249 AM EDT Friday...

Chances of rain continue to increase for Sunday and decrease for Monday. Accordingly, temperatures on Sunday have trended cooler and on Monday trended warmer.

KEY MESSAGES

As of 249 AM EDT Friday...

1. Frost and freeze conditions will end this morning, with another round of frost tonight less likely due to milder temperatures and cloud cover.

2. Light rain and cool weather is expected late Saturday night into Sunday along with locally breezy southeasterly winds. Additional showers are possible on Memorial Day.

3. Remaining unsettled through mid week, with a drying trend looking more likely toward the latter half of the week. Seasonable temperatures expected with no extreme heat or cold anticipated.

DISCUSSION

As of 249 AM EDT Friday...

KEY MESSAGE 1: Aside from this morning's cold conditions, very quiet and uneventful weather is expected today through Saturday as temperatures trend seasonable. Following a mainly sunny day, a large plume of high altitude moisture associated with widespread showers over the Ohio Valley and southerly flow aloft will transport clouds into our region late in the day into tonight. Per the latest HREF, there is strong ensemble agreement that this overcast will reach at least southern portions of our region, with more uncertainty towards the International Border. If these clouds are not as opaque as expected, the MOS guidance, which indicates clear skies, will do well again with low temperatures; this would lead to SLK/Adirondack Regional Airport potentially seeing another freeze and locally other perennial cold spots reaching near freezing. At this time given the above discussion, best chance for needing an additional Frost Advisory for tonight would be in Essex County, Vermont, but overall threat of frost is low tonight.

KEY MESSAGE 2: Overall confidence in a widespread, light rainfall for Sunday continues to increase, although timing of onset and cessation remains challenging to pin down. Precipitation will follow the arc of strongest isentropic lift, with generally a progression from southwest to northeast and steady rain diminishing gradually during the afternoon/evening. Still looks like a decent southeasterly low level jet will develop with inversion height lowering to about 2500 to 3000 feet, promoting some modest downsloping along the western slopes. The EFI highlights the Rutland area with the most significant winds, although nothing unusually strong with potential for a localized gust near 40 MPH. These winds should support slightly higher rainfall amounts in south central Vermont along and east of the mountains, but overall rainfall amounts will be limited with high end amounts currently looking near 0.7". Most guidance shows very weak low pressure and associated lift to enhance precipitation rates, such that rainfall more likely will be only a few hundreths to a quarter inch in most areas, but the rain cooled air will likely lead to a chilly day, especially in our southern/western areas due to an earlier onset of precipitation. Temperatures will largely be in the upper 40s to low 50s.

Following the steady rain, additional showers ahead of a shortwave trough and another weak surface boundary will move into our region either late Sunday night or Monday. Given the more showery rather than stratiform rain along with a shift to westerly winds, temperatures should be much more seasonable on Memorial Day and overall, precipitation chances are relatively low as showers may be scattered in nature.

KEY MESSAGE 3: After a showery holiday weekend, guidance shows a brief break in the precipitation Monday night and Tuesday as high pressure crosses the region. However, another round of showers is expected for mid week as an upper shortwave trough and associated surface cold front swing down out of Canada. Timing of this feature is still somewhat uncertain, though consensus seems to be a Wednesday morning frontal passage. There could be a few embedded thunderstorms, especially if the front ends up coming through closer to the afternoon or evening; even with the earlier timing, the latest GFS indicates a little elevated instability. Regardless, high pressure looks to follow for Thursday into Friday, giving us a drier end to the week. Tuesday will likely be the warmest day ahead of the aforementioned cold front for Wednesday, but even behind the front, temperatures will remain seasonable with highs in the upper 60s to mid 70s and overnight lows mainly in the 40s and 50s.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

Through 06Z Saturday...VFR conditions and light winds will prevail through the entire TAF period. Skies generally SKC-FEW AOA 15 kft, starting to increase and gradually lower after 21z Fri. Winds remaining 5 kt or less.

Outlook...

Saturday: VFR. NO SIG WX. Saturday Night: VFR. Chance SHRA. Sunday: Mainly VFR, with local MVFR possible. Likely SHRA. Sunday Night: Mainly MVFR, with areas VFR possible. Chance SHRA. Memorial Day: Mainly MVFR, with areas IFR possible. Chance SHRA. Monday Night: Mainly VFR, with local IFR possible. NO SIG WX. Tuesday: VFR. Slight chance SHRA, Slight chance TSRA.

CLIMATE

Montpelier, VT (KMPV) and Saranac Lake, NY (KSLK) will see low temperatures near daily records today (May 22). Below are the current records for these sites:

Record | Year | Observed Temperature (as of 2 AM) KMPV: 29 | 2002 | 35 KSLK: 22 | 1935 | 27

BTV WATCHES/WARNINGS/ADVISORIES

VT...Frost Advisory until 8 AM EDT this morning for VTZ009-011- 016>021. Freeze Warning until 8 AM EDT this morning for VTZ003-004- 006>008-010. NY...Frost Advisory until 8 AM EDT this morning for NYZ026-027-087. Freeze Warning until 8 AM EDT this morning for NYZ029>031-034.