textproduct: Burlington

WHAT HAS CHANGED

As of 722 PM EDT Tuesday...

The Wind Advisory and Lake Wind Advisory have been taken down.

KEY MESSAGES

As of 247 PM EDT Tuesday...

1. Gusty winds continue through this afternoon.

2. Showers arrive this afternoon and evening, followed by a rainy Wednesday.

3. Unsettled weather with cooler temperatures this weekend into early next week.

DISCUSSION

As of 247 PM EDT Tuesday...

KEY MESSAGE 1: A low level jet will continue to move overhead this afternoon, bringing wind gusts in the 25 to 40 mph range for most areas. However, localized gusts up to 50 mph are possible, with the strongest winds expected in the St. Lawrence Valley and far northern Adirondacks. The limiting factor for the strong winds will be a broken line of showers moving in from the northwest. Overall, the Wind Advisory remains in effect with no changes. Once the rain arrives, the limited mixing will cause synoptic winds to decrease. Despite the strong winds, relative humidity values around and above 40 percent will prevent significant fire weather concerns.

KEY MESSAGE 2: A cold front pushes into the region this afternoon and evening, bringing a line of showers. The showers have entered the St. Lawrence Valley and will push southeastward as the afternoon progresses. Enough heating has occurred ahead of it that modest instability has developed. The SPC Mesoanalysis indicated that about 500 J of CAPE has developed, with increases up to around 750 J possible by evening. The main limiting factor for storm development will be moisture, with surface dew points continuing to stay in the upper 40s to low 50s ahead of the rain. While they should come up a few degrees this afternoon, the dry air will remain at the time of the precipitation arrival. Other limiting factors will be increasing cloud cover, the lack of a well defined boundary during the day and slight height rises. While there is abundant deep layer shear, due to the limited instability, probabilities of strong to severe storms developing remain modest and are decreasing. However, a few rumbles of thunder are expected. The strong shear may act more to blow off the top of the storms and weaken them than help organize them due to the modest instability. Overall, there is not much change in thinking from yesterday and it looks to be a lower end marginal case. Widespread showers should occur tonight as the front slows down across the region, but by that point, the precipitation should be mostly stratiform and synoptically forced. Widespread stratiform rainfall will occur for most of the day Wednesday as a low develops along the front, making it a complete washout for most areas. 1-2 inches are expected in total. Due to the light stratiform rates, flooding is not expected, though river rises will occur. Temperatures will be in the 40s for most areas, though southeastern Vermont should see 60s as they will be south of the precip and front. An isothermal profile will prevent much snow in the mountains despite cool temperatures. Showery and cool conditions will occur through the end of the week.

KEY MESSAGE 3: Several chances for showers are expected from Friday night through Tuesday. General troughiness will remain over the northeastern CONUS, leading to clouds and chances for precipitation. As multiple shortwaves round the base of the upper level trough and cross our forecast area, we can expect off and on periods of rain over the weekend and into early next week. Temperatures will continue to be cooler than normal, but will be warm enough to support rain as the dominant precipitation type in all but the highest elevations. Overnight low temperatures may support some frost development this weekend (depending on evolution of cloud cover and overnight winds), especially Saturday morning in the northern Adirondacks and eastern Vermont. However, the Champlain Valley is the only area within our forecast area of responsibility that has started the "growing season" as per our frost-freeze program, and conditions there will remain warm enough to preclude a frost threat. Therefore headlines are not anticipated, but keep an extra eye on the late week/weekend forecast if you have sensitive vegetation.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Through 06Z Thursday...Light rain with embedded heavier down pours continue to angle across our taf sites this morning along a developing stationary boundary. Crnt observations range from IFR cigs at SLK to MVFR vis/cigs at MPV/RUT and VFR elsewhere. The general trend will be toward MVFR cigs btwn 09-12z with IFR developing at many taf sites between 12-15z, especially as north/northwest blocked flow develops at BTV/RUT and MPV. SLK is a little tricky with east-northeast boundary layer winds this morning, which could delay redevelopment of IFR or lower cigs, while intervals of IFR cigs are likely after 15z at PBG due to the northeast winds. Periods of rain with VFR vis will trend toward MVFR vis in the 3-5SM range by Weds morning, which should continue into the afternoon hours. Eventually rain will lift east of our taf sites by 21z with lingering light rain/drizzle possible and IFR/lIFR cigs likely, especially mountain taf sites thru 00z. Winds are southwest acrs our southern taf sites and north near the International Border, become all northwest/north by 15z this morning at 4 to 8 knots.

Outlook...

Thursday: VFR. NO SIG WX. Thursday Night: VFR. NO SIG WX. Friday: VFR. Slight chance SHRA. Friday Night: VFR. Chance SHRA. Saturday: VFR. Chance SHRA. Saturday Night: VFR. Chance SHRA. Sunday: Mainly VFR, with local MVFR possible. Chance SHRA.

BTV WATCHES/WARNINGS/ADVISORIES

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