textproduct: Burlington

WHAT HAS CHANGED

As of 233 PM EDT Thursday...

The timing of a trough on Saturday evening is somewhat earlier with this latest update.

KEY MESSAGES

As of 221 AM EDT Friday...

1. The upper low responsible for rainy weather will pull away later today with rain chances decreasing after tonight.

2. Building heat is anticipated through early next week.

3. Above normal temperatures are expected for the start of next week.

DISCUSSION

As of 221 AM EDT Friday...

KEY MESSAGE 1: The center of a strong upper low is skirting the Pennsylvania-New York border on its way eastwards. Some dry air has wrapped into it this evening, present much of Vermont now. Wrap around activity now mostly resides over northern New York a few showers in Vermont. As the upper low starts making eastward progress, wrap around will arc southeastwards with a gradual decay as it becomes increasingly disconnected from the Atlantic moisture source. By late morning and early afternoon rain will exit east.

Steady clearing is expected on the western edge of the upper low. Temperatures will climb into the 60s to near 70 as we finally get some sunshine. Cool temperatures aloft and lingering moisture will result in marginal surface instability, up to 250 J/kg. So isolated to scattered showers will develop during the afternoon and evening hours. Loss of daytime heating and some incoming mid-level dry air will put a stop to shower activity tonight. A ridge will begin to nose in, and this will add some light, but steady winds. These winds will be lighter across Vermont, and so some level of decoupling is possible. Guidance is mixed on the potential, but given 1-2" of recent rain, it probably won't take much to fog across Vermont.

KEY MESSAGE 2: A narrow upper ridge will crest Saturday with southwesterly flow bringing widespread 70s to the area. Modestly compacted pressure gradients will result in breezy flow, with winds 10-15 mph developing later Saturday morning, and with gusts of 20-30 mph. After having slowed the timing of the trough on Saturday, today's guidance has decided to reverse course. Assessing the model soundings, low-level conditions will be quite dry (min RH around 30- 40%). Most precipitation will likely evaporate and not truly measure, but did raise PoPs with human factors in mind for all the weekend activities. Any rain that falls may also trigger some gusts to mix from aloft due to the evaporative cooling. Fortunately, the bulk of the stronger flow aloft arrives after this mid-level moisture tracks east, but highly localized stronger gusts cannot be discounted.

Saturday night into Sunday, the trough will shift southeast, but not cleanly make it out before the heat of the day. So areas along the international border will be closer to 70 while southern Vermont should see a few readings in the lower 80s. A spot shower will be possible in the Northeast Kingdom on Sunday, but much of the region will be largely dry.

A more substantial upper ridge will build on Monday. A strong warm front will pass northeast Monday morning. Without a pocket of increased vorticity and meager moisture, this front will likely slide through without triggering rain. Although it may not take much to spark a shower if anything is running around "upstairs", as there is some mid-level instability, and so I won't say that it's impossible. The increase of south to southwest winds will announce the arrival of the front and associated warmth. Temperatures will ascend into the 80s outside the Northeast Kingdom on Monday.

KEY MESSAGE 3: A warming trend will continue into the first half of next week as ridging builds into the region. Tuesday looks to be the warmest day, with high temperatures climbing into the 80s for most locations, with 925mb temperatures around 22C to 25C. These temperatures will be the warmest of the year so far, so it is important to remember to stay safe in warmer temperatures by staying hydrated and take frequent breaks if working outside. Overnight lows look to be above normal as well, generally in the upper 40s and 50s, warming to almost 60 for Tuesday night. A few chances for precipitation may be possible early next week as a shortwave moves through the region, which could have an impact on how high temperatures climb on Tuesday. A more robust frontal boundary look to move through the region for mid-week, bring increased chances of showers and thunderstorms, with more seasonable conditions expected later in the week behind the front.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

Through 12Z Saturday...Variable flight conditions currently prevail across the region this morning, anywhere from VFR to LIFR, as rain continues to exit the region. Conditions will continue to improve over the next few hours, with ceilings improve towards VFR for most terminals by 21Z. Isolated to scattered showers are possible in the afternoon, mainly over the higher terrain. Winds looks to be light and variable throughout the forecast period.

Outlook...

Saturday: VFR. NO SIG WX. Saturday Night: VFR. Slight chance SHRA. Sunday: VFR. NO SIG WX. Sunday Night: VFR. NO SIG WX. Monday: VFR. NO SIG WX. Monday Night: VFR. Chance SHRA. Tuesday: VFR. Chance SHRA, Slight chance TSRA.

BTV WATCHES/WARNINGS/ADVISORIES

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