textproduct: Burlington

WHAT HAS CHANGED

As of 222 PM EDT Wednesday...

No significant changes were made to the forecast.

KEY MESSAGES

As of 248 PM EDT Wednesday...

1. Seasonably warm weather will continue through Friday areawide. Due to low humidity and temperatures mainly in the 80s, only a minor to moderate heat risk is expected on Thursday and Friday.

2. Showers are expected on Saturday, with potential for a few thunderstorms during the afternoon.

3. Seasonable and rainy conditions expected to end the weekend, resulting a few river rises but no major impacts anticipated. Then, drier and warmer weather returns next week.

DISCUSSION

As of 248 PM EDT Wednesday...

KEY MESSAGE 1: A large ridge of high pressure centered over the Great Lakes region is providing us with ideal conditions for low humidity and clear skies. Winds will remain on the light side as the sprawling ridge gradually shifts eastward while surface high pressure weakens and moves into the southern US. The position of this high will prevent development of significant heat to build. During the day Thursday, as our winds shift to more of a light west to southwest direction, we therefore won't be advecting in particularly hot air. That being said, it is still June and the air mass will be very warm with temperatures expected to reach bump up into the mid to upper 80s with a few spot 90s in our lower elevations up to about 1000 feet, and low 80s near 1000 to 2000 feet. This type of warmth will affect people sensitive to heat, but will not warrant a Heat Advisory. Temperatures on Friday have trended warmer with greater likelihood of plentiful sunshine and similar or even slightly warmer temperatures aloft. So high temperatures Friday are now near or a degree or two above Thursday, although clouds will be on the increase with a bit of an uptick in humidity.

KEY MESSAGE 2: While a general thunderstorm risk from the Storm Prediction Center begins Friday night for northern New York and northwestern Vermont, associated with a lead shortwave well ahead of an incoming cold front, much greater chances for showers and thunderstorms remains for Saturday. It should be noted while chances of rain are very high, precipitation may be on the scattered side such that many hours will be dry for a given location; as we get closer we'll be able to improve the details both in location and timing.

Generally, with increasing low level moisture including truly humid air (dew points getting into the 60s) and moderate heat in place in our region, we are track to see ingredients for showers and thunderstorms as a fairly vigorous mid-upper level shortwave approaches from the west concurrent with a weak surface cold front situated to our north and west. The output from the latest RRFS model run, which is a CAM that extends to 84 hours, is largely consistent with this idea. Its output shows greatest CAPE generally out ahead of where most shower activity develops across Vermont and especially central and eastern areas during the midday hours, with additional instability building back across northern New York and south output favors thunderstorms to our south with less coverage across northern New York and Vermont. Generally, thunderstorm potential will be related to showers/coverage of rain during the midday hours would reduce the probabilities of thunderstorms as cloud cover would sap us of potential instability. That being said, some of the latest guidance compared to 24 hours ago shows more substantial vertical wind shear (mainly speed rather than directional shear) overhead concurrent with peak heating. As such, the threat of a stronger thunderstorm or two is in the realm of possibility for this event.

In addition to lightning and wind risk with any deeper/stronger updrafts, forecast soundings suggest some showers will be capable of heavy rainfall rates. Parameters such as the PWAT (values around 2 standard deviations above normal), warm cloud depths (near 10,000 feet), and low corfidi upshear wind speeds (ability for showers to train), are supportive of heavy rain but only marginally so. No guidance at this time is pointing to excessive rainfall amounts, as there is low probability of even 1"/ 6 hour rainfall, but it bears watching with somewhat slow moving boundaries in place during the event.

KEY MESSAGE 3: Upper level troughing is expected to slide through Quebec into the Canadian maritimes Saturday and Saturday night, though deterministic models disagree on the strength and precise track of this low. At the surface, low pressure will sink southeastward across New England into Sunday, dragging with it a frontal boundary that may end up stalling over the region. This means steady light rain is anticipated Saturday night and Sunday morning, with some precipitation likely lingering in southern vermont Sunday afternoon. The setup suggests at least a quarter to a third of an inch of precipitation Saturday night and Sunday is likely for most of Vermont, with lower probabilities in northern New York. Increased cloud coverage will keep conditions relatively mild overnight with lows in the mid 50s to lower 60s. On the flip side, clouds and rain should limit temperatures for much of the day Sunday. That being said, highs should reach seasonable levels in the lower and mid 70s as the day sees gradual drying and clearing. Given the extent of the dryness leading up to the rain this weekend, we do not anticipate flooding issues, though some river rises are possible, especially if a basin receives any thunderstorms Saturday ahead of the steadier rain Saturday night and Sunday. Early next week, large scale ridging will build in from the northwest with ensembles favoring a return to dry and warm conditions. Highs are expected to rise to widespread 80s midweek, several degrees above normal, and lows will also be warm in the 50s and 60s.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Through 18Z Thursday...Dry weather is expected from today through Friday as surface and upper level ridges build over the region. High confidence in all terminal VFR conditions through the next 24 hours. Variable winds this afternoon with an overall northwesterly direction will turn more south-southwesterly tonight, growing lighter and at times becoming variable, in some places even going calm for a period. RUT will likely have its typical southeasterly drainage flow. Thursday morning, we'll see the wind shift a touch more west-southwesterly, increasing to 5-10 knots, potentially higher at MSS where channeling flow through the St. Lawrence Valley will increase winds. Around 14Z-17Z Thursday, we could start to see some gusts of 15-20 knots begin, though MSS could have gusts approaching 25 knots.

Outlook...

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

CLIMATE

Temperatures will be approaching daily record warm values on Thursday, June 4th, and Friday, June 5th. At this time, Plattsburgh (PBG) and Montpelier (MPV) have the greatest chances of setting a new record.

Record High Temperatures:

June 4: KMPV: 87/2025 KPBG: 88/1967

June 5: KMPV: 86/2025 KPBG: 90/2020

Record High Minimum Temperatures:

June 5: KPBG: 65/1963

June 6: KPBG: 67/1973

BTV WATCHES/WARNINGS/ADVISORIES

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