textproduct: Burlington

WHAT HAS CHANGED

As of 229 PM EDT Thursday...

No significant changes we made to the forecast.

KEY MESSAGES

As of 229 PM EDT Thursday...

1. A Bermuda high pattern will set up today through the weekend, which will bring warm, humid conditions and daily chances for showers and thunderstorms. A few will be capable of locally heavy rain.

2. Cooler temperatures are expected next week with a couple chances for additional showers.

DISCUSSION

As of 229 PM EDT Thursday...

KEY MESSAGE 1: A Bermuda high will develop off the coast of the SE CONUS leading to anticyclonic flow to our south, aiding in the advection of increasing moisture and warmer air. Broad cyclonic flow, north of the Bermuda high, over our region, in association with increasing warm and moist air, will lead to several shortwaves each day through the weekend. While there is not a real defined boundary, diurnally driven instability in tandem with a modest shortwave is supporting scattered showers and thunderstorms currently over the Adirondacks. Mesoanalysis denotes terrain instability around 1000-1500J/kg with around 20-30 knots of shear early this afternoon, though mid level lapse rates appear to be modest at best around 5-6C/km. With light southwesterly flow, some of these showers will drift east into the Champlain Valley by early to mid this afternoon. Should ingredients align, there is a chance for some stronger storms, mainly over the Adirondacks, with lesser chances in the central Champlain Valley. As opposed to previous forecasts, the probability of any wet microbursts looks to have weakened with the axis of better DCAPE west of the instability axis. Nonetheless, a sub severe stronger gust may be possible as cells decay. The main impacts today will be the chance for locally heavy rain. Good moisture advection with PWs approaching 2" will lead to some heavy downpours under any showers today. Showers are expected to wane by sunset with the loss of diurnal heating. Temperatures will remain elevated with lingering moist conditions. It will still feel muggy with temperatures only lowering to the upper 60s to low 70s, and dewpoints still in the upper 60s to low 70s as well. A few high min temperature records may be approached or broken tonight as a result, particularly at PBG. With ambient low level moisture, regardless of cloud cover, patchy fog may be possible in the usual river valleys, and could even drift into the unfavored locations, should an area receive showers this afternoon.

By Friday, southwesterly flow and shear will increase to 30-40 knots with similar instability levels, expanding into the northern Champlain Valley as well. Afternoon scattered showers and thunderstorms are anticipated, mainly over the terrain. Shower coverage will be less than today with reduced chances for any stronger storms due to the lack of a defined trough. Any storms will also wane with the loss of diurnal heating in the evenings. Saturday looks to be the best chance areawide for any showers and thunderstorms. Widespread instability with a more defined trough are expected. Temperature wise, highs will get a degree or two cooler each day as the Bermuda High slowly sinks south as troughing becomes more dominate towards the end of the weekend.

KEY MESSAGE 2: As Bermuda high weakens and westerly flows prevails across the region, will see a cooling temperature trend next week. Highs at the start of the week will be in the upper 70s to mid 80s, but by the middle of the week they will drop a few degrees to be in the lower 70s and low 80s. A couple fronts will move through the region bringing widespread showers and a few possible thunderstorms, although the timing of the boundaries will have a large influence on any convective elements.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Through 00Z Saturday...Ongoing scattered showers, and a couple of thunderstorms currently in the Champlain Valley, are moving towards the east and should diminish gradually over the next couple of hours. No direct hits are expected based on radar trends, but a vicinity thunder or shower is plausible at PBG and BTV through this evening.

Otherwise, with light winds across the airspace through the period, we will have fog potential given moist low level conditions. Climatologically favored sites SLK, MPV, and EFK, should all see at least a few hours of fog overnight. Meanwhile, PBG and BTV are somewhat favored for at least periods of BR tonight given likelihood of having some rain around sunset in addition to well over 0.5" of new rainfall that occurred in the mid to late afternoon. Have also noted MSS will be capable of seeing intermittent fog but for now have just BR given low statistical probabilities of IFR visibilities (below 20% for any given hour), while RUT currently looks unlikely to see reductions in visibility.

Outlook...

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

BTV WATCHES/WARNINGS/ADVISORIES

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