textproduct: Burlington

WHAT HAS CHANGED

As of 214 AM EDT Wednesday...

Rainfall amounts have increased, mainly across Vermont for Thursday into Friday. This will still be largely beneficial for the region.

KEY MESSAGES

As of 214 AM EDT Wednesday...

1. Wet weather ahead with beneficial rains over the region.

2. Temperatures warm above seasonal normals heading into early next week, with a few chances for showers possible.

DISCUSSION

As of 214 AM EDT Wednesday...

KEY MESSAGE 1: Satellite shows a now closed off upper low tracking southeast along the Upper Peninsula of Michigan and RAP analyzed surface low over the Mitt is slowly deepening. Satellite shows a well-defined baroclinic leaf for the warm conveyor belt with the attendant warm front. The initial part collapsed beneath dry air, but KTYX base reflectivity shows this next push of moisture will more likely reach the surface. Even this is not the warm front, and as rain translates northeast, it will fade. The main push arrives later this morning and afternoon with a well-defined warm front that will quickly races northeastwards. Some drying within the warm sector will take place this afternoon and evening. Then, as the upper low approaches, excellent upper diffluence and sufficient moisture will produce scattered to numerous showers as weak instability of 150-350 J/kg develops. A low probability for a thunderstorm exists in St. Lawrence and Franklin Counties of New York.

It continues to look like that the loss of daytime heating and a decrease in frontal forcing will cause precipitation to decrease overnight. However, as the upper low ambles eastwards, the upper level southeasterly flow and secondary development near Long Island will result in moisture overrunning the remnant boundary, mostly towards Vermont early Thursday morning and afternoon. Compared to yesterday, the main trend has been for the parent low and secondary low to linger longer, as opposed to getting more broadly absorbed into another surface low east of the 40 N, 70 W benchmark. In the grand scheme of things, this doesn't change much, but it does result in a somewhat higher chance for rain continuing into Friday across Vermont, while dry air still remains more prevalent over northern New York.

Rainfall amounts have increased somewhat, but this will be beneficial. Most locations are running 1-2" below normal for liquid amounts year-to-date, and this will reduce that gap. The long duration will preclude flooding. Although convective elements may appear at times, parameters are marginal and PWATs are not particularly off the charts never getting above 1". Moderate rain could develop at times given the favorable forcing. Some high resolution guidance appears to be suffering from convective feedback with heavy rainfall rates, but little instability, and so the higher end of modeled rainfall forecasts should be taken with caution. The general picture of 0.50-1.00" continues, with favored eastern slopes of the Dacks and Greens closer to 1.50". Some areas could receive localized amounts to 1.75". HREF and REFS probabilities of 1.50" range between 10-40% across the region, with some higher chances over mountains, and generally 10% or less for 2".

By Saturday, we should be clearing out. Ridging builds and warm air starts filtering in across northern New York and Vermont. After the stretch of cool weather, reaching the 70s will feel quite welcome on Saturday. Another trough will start swinging southeast Saturday evening. There remains some uncertainty on the timing and whether precipitation can develop, especially with little in the way of forcing or instability beneath this ridge axis, but a low end chance for some rain is possible.

KEY MESSAGE 2: Heading into the weekend, low pressure looks to shift out of the region towards the Canadian Maritimes, with high pressure trying to nose into the region, bringing mostly dry conditions. Warming temperatures aloft will make for a warming trend as we head into the beginning of next week, with temperatures near or above climatological normals for this time of year. Daytime highs look to climb in the 70s and even 80s, with overnight lows in the 40s to mid 50s. While there is high confidence in the warming trend, there is lower confidence in the exact magnitude of the warmth, especially at this time frame. A few chances for precipitation look to be possible early next week as a shortwave moves through the region, with more robust precipitation expected mid-week as a frontal boundary pushes across the region.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Through 06Z Thursday...VFR conditions will continue for the next few hours as cloud cover continues to increase across the region associated with an approaching warm front, which will bring widespread rainfall for much of the day. With dry air in place across the region, it may take a little for precipitation to reach the ground, but precipitation is expected to arrive between 12Z and 15Z, with ceilings lowering to MVFR in this time period as well. MVFR conditions are expected to continue through the TAF period, due to a combination of ceilings and visibilities within rain showers. There is some potential of IFR ceilings developing during the afternoon, however confidence and model consensus is low so left them out of the forecast for now. Winds are currently light and variable, but will trend southerly towards 12Z, with some gusts of 20 to 25 knots possible in the afternoon. Some LLWS will be possible at most terminals this afternoon as a low level jet moves overhead.

Outlook...

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

BTV WATCHES/WARNINGS/ADVISORIES

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