Area Forecast Discussion
Issued by NWS Burlington, VT
Issued by NWS Burlington, VT
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000 FXUS61 KBTV 062133 AFDBTV Area Forecast Discussion National Weather Service Burlington VT 533 PM EDT Sat Jul 6 2024 .SYNOPSIS... Mostly dry weather will start off the week, though an isolated shower is possible tomorrow. The heat and humidity will remain in place as well. A cold front will approach on Wednesday and bring some showers and storms. Some of these could produce locally heavy rainfall. && .NEAR TERM /THROUGH SUNDAY NIGHT/... As of 532 PM EDT Saturday...A few areas of convection have developed this afternoon, and scattered showers will continue for the rest of the day. The most numerous showers are along a very weak nearly- stationary boundary located across central Vermont. However, it has been moving just quick enough to prevent repeated training storms. With 1-1.5 inches of rain falling across parts of the region this morning, there are a few areas vulnerable to localized flash flooding. However, there would likely need to be multiple training storms, and that has not been occurring. Storm motion should continue to be faster, so that is unlikely to occur during the rest of the day. Model soundings show a subtle mid-level inversion at around 20-25K feet, corresponding to around the -10 to -20 degrees celsius level. That has been able to top the convection and prevent much lightning from occurring. Continued daytime heating looks to allow the convection to reach a little higher and that could lead to a few more storms with lightning, but overall most of the convection should not contain lightning. The convection will die down this evening and skies should at least partially clear. With light winds, high dewpoints/crossover temperatures and recent rainfall, fog will develop, especially across Vermont where wind will be the lightest. Drier weather returns for Monday but there will be a weak shortwave passing to the north of the region and that could set off a shower or two across northern areas. The heat will continue for Sunday with highs in the 80s again, but dew points will drop off slightly into the 60s. Patchy fog looks to develop Sunday night as well. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... As of 532 PM EDT Saturday...Surface high pressure moves overhead on Monday, and recent cold front passage (Sat) brings in drier air at the surface and aloft, thus it should be sunny and very warm again. Decent surface heating should mix drier air to the surface thus it should be very warm but dry. Highs in the M80s-L90s. Surface high shifting east Monday night allowing return flow to bring an increase in moisture at all levels that have been plaguing the Tristate and Mid-Atlantic for some time, thus increasing dewpoints with lows in the 60s to around 70. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 532 PM EDT Saturday...Bermuda High offshore and northern stream disturbance moving across the Great Lakes on Tuesday will continue the SSW warm and increasingly humid airmass into our region. Ensemble PWATs show 1.5- 1.75 inches across our area with 1.75-2 inches across SNE and Hudson Vly southward with over 2 inches from NYC southward. Deterministic models have higher values and advect some of these higher PWATS just ahead of approving northern stream system. There is some higher level moisture from Beryl getting entrained along the approaching frontal boundary, but the main moisture source is locally grown with PWATS greater than 90th percentile across our area with rising warm cloud depth layers for likely efficient rain producing showers and thunderstorms. The big question is how much activity, timing and is there more than one round? Unfortunately, the picture isn`t very clear but the general consensus is daytime heating, instability and likely position of a pre-frontal trof across NY will be a focus of shower/t-storms with mid-level energy moving across the area as well. The mid-low level flow appears nearly parallel to the boundary thus likely looking at potential training showers/t-storms while the mid-level trof continues to lift ENE for the boundary to slowly push across NY-VT late Tuesday-Tuesday night and perhaps be east of area by Wed AM. At this time...a general 1/2-1 inch with localized training of 2+ inches not out of the question. WPC has the area in Marginal risk attm and feel that is justified. Still under somewhat cyclonic flow on Wednesday with PWATS still 1.25 and higher and another weak shortwave and secondary cold front pushing through for another round of showers and possible thunder...esp southern areas. While all of this is happening, the upper level Bermuda High is strengthening thus the second frontal boundary that passes Wed is never too far away and lies across eastern and southern New England so can`t rule out shower threat, mainly south on Thursday while high pressure tries to make progress across the northern tier. As we get into Thu Ngt-Friday...the mid-level energy of what was Beryl gets lifted and captured into the general trofiness across the Great Lakes and Ms Rvr Vly. The weak surface reflection moves into the Ms Rvr Vly and Ohio Rvr Vly and then eventually across the northeast as a possible weak surface wave. Meanwhile, the strengthening Bermuda High begins to push the previous cold front as a warm front with the main story being rich moisture (PWATS 1.75-2+ inches) across SNE and mid-Atlantic advecting back towards our area. Will these two identities move across the area separate or will they interact for more organized rounds of rain and heavy rain showers. Still too early but worth to monitor closely. At the very least it looks showery and wet for Friday and Saturday. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... Through 18Z Sunday...Any remaining MVFR ceilings will lift early this afternoon and VFR conditions should prevail into the evening at all terminals. Some scattered showers and storms will develop across the region this afternoon, and if any of them happen to hit a specific terminal, the visibility could briefly lower to MVFR. An embedded thunderstorm cannot be ruled out, but that would be widely scattered and the odds of one hitting a specific terminal are low. Any rain showers will dissipate in the evening and it will be a dry night. However, with clearing skies and light winds, patchy fog will develop across the region. It looks like it will be most prevalent in Vermont though it cannot be ruled out at any terminal. The likeliest terminals to see fog are MPV, EFK, and probably SLK. The fog will dissipate after daybreak and VFR conditions should prevail throughout the day. Winds will generally be light during this period and LLWS is not a concern. Outlook... Sunday Night: VFR. Patchy BR. Monday: VFR. NO SIG WX. Monday Night: VFR. NO SIG WX. Tuesday: VFR. Chance SHRA, Slight chance TSRA. Tuesday Night: Mainly VFR, with local IFR possible. Likely SHRA, Slight chance TSRA. Wednesday: Mainly VFR, with areas MVFR possible. Chance SHRA, Slight chance TSRA. Wednesday Night: Mainly VFR, with local IFR possible. Chance SHRA. Thursday: Mainly VFR, with local MVFR possible. Chance SHRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Myskowski NEAR TERM...Myskowski SHORT TERM...SLW LONG TERM...SLW AVIATION...Myskowski