textproduct: Burlington

WHAT HAS CHANGED

As of 226 PM EDT Monday...

No significant changes.

KEY MESSAGES

As of 226 PM EDT Monday...

1. Widespread rain this evening and tonight.

2. Mostly dry with a few isolated showers mid-week.

3. Showery conditions return Thursday through early next week.

DISCUSSION

As of 226 PM EDT Monday...

KEY MESSAGE 1: An area of low pressure moves through the region this evening and tonight, bringing an area of stratiform rain. The center will track from the Southern Tier of New York northeast across far southern Vermont and into the Gulf of Maine. This keeps the region on the cooler northern side and will prevent any thunderstorms or severe weather. Rainfall rates will be light to moderate and this is expected to prevent any flood risk. Rainfall rates should be under 0.25 inches per hour. A deformation axis looks to form over parts of southern Vermont this evening and could briefly lead to locally higher rainfall rates. A few areas of elevated convection may develop tonight behind the stratiform rain but they will be isolated and quick moving. Overall, around 1-1.5 inches of rain is expected across southern Vermont, with totals dropping off very quickly heading north. Less than a tenth of an inch is expected in northern areas and along the international border. The precipitation exits before dawn tomorrow.

KEY MESSAGE 2: While large scale troughing will remain in place through mid-week, most shortwave activity will stay to the north over Quebec, bringing a drier stretch. However, cool temperatures aloft and diurnal heating will cause chances for isolated showers. A couple showers are possible over northern New York Tuesday afternoon where the most clearing will occur. Isolated to scattered showers are most likely on Wednesday near the international border where the synoptic forcing will be the strongest. However, those days will still be almost completely dry.

KEY MESSAGE 3: The weak ridge providing a short reprieve from the showery weather will give way on Thursday afternoon. At the crest of the ridge axis, the shift in air masses with sufficient moisture will generate a few showers, mainly across the Northeast Kingdom early in the afternoon. The bulk of activity will be later in the evening, as some mid-level vorticity ahead of the base of an incoming trough and marginal daytime instability of about 300-500 J/kg will support some activity along the incoming boundary. Given how light the flow is until you get above 400mb, any thunderstorms will be garden variety. A broad, disorganized surface low will translated eastwards overnight, which will allow rain chances to continue into Friday.

The low will be just east of the region by Friday afternoon. Although better synoptic forcing for ascent will be east, the upper trough will still exert some influence. We may be able to generate somewhat greater instability, and there will be some shear, but we'll have to monitor how much mid-level dry air is present going forward.

Although a ridge will try to build in for Saturday, yet another upper trough will move in from the west. It could produce some more shower activity Saturday into Sunday, but it appears quite a bit weaker than the last few series of troughs. Temperatures will fairly seasonable during this stretch, and then begin to hem towards the warmer than average for the new week as an expansive upper high builds east across the central CONUS.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

Through 06Z Wednesday...Primary aviation hazard during this period will be potential for low ceilings, particularly over the next 6 to 8 hours or so as weak low pressure pulls away. Light wind fields and moist conditions, in southern portions of Vermont in particular, lead to high likelihood of prevailing IFR conditions at MPV and RUT for much of the period now through 12-14Z. Expect more of an MVFR versus VFR situation at other terminals as ceilings should trend lower before scattering gradually after sunrise. However, cannot rule out BR and some IFR conditions, especially at MSS where partial clearing could promote occasional fog/very low ceilings at the airport. Calm/terrain driven winds will remain light but increase slightly after 12Z out of the northwest.

Outlook...

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

BTV WATCHES/WARNINGS/ADVISORIES

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