textproduct: Burlington

WHAT HAS CHANGED

As of 242 PM EDT Monday...

No significant changes were made to the forecast with this package.

KEY MESSAGES

As of 242 PM EDT Monday...

1. Scattered showers persist this afternoon, with another round expected on Tuesday as we remain under an upper level trough.

2. Showery and mild end to the week before trending drier and cooler over the weekend.

DISCUSSION

As of 242 PM EDT Monday...

KEY MESSAGE 1: Showers are becoming more widespread early this afternoon, particularly across the northern Adirondacks, across Lake Champlain and into northern Vermont. This activity is associated with an upper level trough that is swinging across eastern Ontario and into southern Quebec. Some of the more robust showers this afternoon could produce a few rumbles of thunder along with some locally gusty winds to maybe 30 mph or so, but nothing strong/severe is anticipated. Showers will wane in coverage with sunset, except downwind of Lake Ontario, where W/SW flow over the relatively warm water will allow for lake enhanced showers to linger overnight. The bulk of the moisture, cloud cover, and precipitation will remain across NY. Vermont should see at least some clearing overnight, which should allow river valley fog to form again tonight/early Tuesday. Lows tonight will be comfortable, mainly in the 50s, though some of the more sheltered locations could drop into the 40s.

The upper trough will slowly slide along the international border on Tuesday, providing lift for another round of scattered showers. Coverage and intensity should be less than today, and any thunderstorms fairly isolated. Winds will turn to the northwest during the afternoon once the trough axis moves to our east, ushering in some drier air. Highs will generally be in the 70s, though some spots in the Adirondacks and Northeast Kingdom may remain in the 60s. After another comfortable night Tuesday night, Wednesday should be a pleasant day. Clouds will develop during the afternoon, but no rain is expected. Highs will be in the 70s to around 80F.

KEY MESSAGE 2: Late this week, upper level troughing will rotate across eastern Canada, anchored over Hudson Bay, sending a surface low through Quebec and its associated frontal boundaries swinging across northern New York and Vermont Thursday afternoon through Friday. Chances of measurable precipitation run around 60-90% during this time frame, highest Thursday afternoon and evening (first round) as well as Friday morning and afternoon (second round and stronger cold front). Thursday is looking like the warmest day of the week for most of us as highs reach the upper 70s and lower 80s in southerly flow. Thursday night should also be mild as southerly flow continues with lows in the mid 50s to mid 60s. Friday will be a touch cooler but still relatively warm with highs in the 70s and lower 80s. Then, following the passage of the cold front, we see lows drop into the 40s to mid 50s over the weekend as showers come to an end Friday night. Deterministic guidance consensus also diverges over the weekend, so changes to this forecast are possible over the next few days. At the moment, upper cyclonic flow continues over Canada while surface high pressure builds in over the northeastern US, so weekend highs are likely to be seasonable in the 70s, though a few low 80s in the southern and wider valleys are possible. High pressure looks to start breaking down Sunday or Sunday night, resulting in the return of shower chances heading into the start of the next work week as the trough shifts into the Canadian maritimes, dragging a cold front towards the Northeast. There remains a wide range of possible high temperatures on Monday, anywhere from the 60s to lower 80s. Current forecast leans on the warmer side, in line with ensemble and blended guidance, but there is the potential for conditions to be quite a bit cooler if we're to believe the deterministic global models.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Through 00Z Wednesday...At this stage, showers are mainly positioned across the St. Lawrence Valley with little activity from the Adirondacks eastwards. Winds are south to southwest around 5 knots, but is still 10 knots with a few gusts 17-20 knots at KMSS. Winds are expected to trend towards 5 knots or less overnight. Intermittent showers at KSLK, and possibly KMSS, will likely trap moisture near or below an inversion and bring ceilings down towards 800 ft agl. Across Vermont, more patchy cloud cover could allow some fog development, mainly along the Connecticut River Valley, but thinking KMPV will likely observe some IFR visibilities or ceilings at times through 12-13z. After 13z, winds will become variable and ceilings will lift with sunrise. A boundary will shift southeast across northern New York about 14z-17z, and then into Vermont about 18z-21z, which will shift winds to the northwest, mainly around 5-8 knots, but briefly higher sustained winds or gusts could occur. Behind this boundary, ceilings will trend VFR.

Outlook...

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

BTV WATCHES/WARNINGS/ADVISORIES

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