textproduct: Burlington

WHAT HAS CHANGED

As of 736 PM EDT Monday...

A Lake Wind Advisory has been issued for Lake Champlain

KEY MESSAGES

As of 246 PM EDT Monday...

1. Gusty winds tomorrow.

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

3. No major impacts or significant weather expected late week into next weekend, as the pattern continues to support unsettled conditions with below normal temperatures.

DISCUSSION

As of 246 PM EDT Monday...

KEY MESSAGE 1: A low level jet moves overhead tomorrow, bringing wind gusts in the 25 to 35 mph range for most areas. However, localized gusts up to 40 or even 45 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. Once the rain arrives, the limited mixing will cause synoptic winds to decrease. Despite the strong winds, relative humidity values being around and over 40 percent will prevent significant fire weather concerns.

KEY MESSAGE 2: A cold front pushes into the region Tuesday afternoon and evening, bringing a line of showers. While a few scattered showers are possible earlier, the organized precipitation looks to enter northern New York in the afternoon and Vermont in the evening. Enough heating looks to occur ahead of it that modest instability will develop. HREF mean values range between 250 and 750 J. The main limiting factor for storm development will be moisture, with surface dew points looking to be in the 40s to mid 50s at the time of the precipitation's 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, strong to severe storms currently look unlikely, though a few rumbles of thunder are possible. 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. The scenario to watch would be if something develops along a pre-frontal trough in the afternoon, something akin to what the NAM3 has, though its dew points currently look too high. Overall, there is not much change in thinking from yesterday and it looks to be a lower end marginal case. Widespread showers should occur Tuesday night 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. 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. Cool weather and a few showers will occur Thursday.

KEY MESSAGE 3: Aside from Friday night when consensus is strong on dry weather, some daily chances for showers will persist through the weekend with another longwave trough parked over the area. Best chances for showers is currently Saturday. Any showers look to favor a more scattered nature than prevailing rain with an upper low continuing to gyrate about the Hudson Bay in Canada, and low level lapse rate steepening under cooling air aloft. Shallow instability will also aid any shower development, with similar conditions to this last weekend. However, while the pattern will be similar to last weekend, ensembles do not appear as cold. GEFS/EPS thermal profiles support temperatures this weekend in the upper 50s to low 60s for daytime highs, and mid 30s to near 40 for overnight lows. Drying mid level air columns towards the surface Friday night, in addition to some calming winds may support some temperatures conducive for frost Friday and Saturday mornings, however, looking upstream, cloud cover over central Canada (where our weekend airmass will originate), is fairly widespread which attm reduces confidence in any frost. Though we will continue to monitor trends.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Through 00Z Wednesday...Gusty winds tomorrow. Showers arrive Tuesday afternoon and evening, followed by a rainy Wednesday. VFR conditions are expected to prevail through at least 12Z Tuesday under subtle ridging. Winds out of the southwest 5-15 knots this evening with scattered gusts 15-25 knots are expected to continue overnight tonight, increasing to sustained 15-25 knots with gusts 25-35 knots by around 09Z-15Z Tuesday, the highest in the St. Lawrence Valley where SW channeling could allow for gusts 35-40 knots at MSS after 18Z Tuesday. Winds aloft will also be on the increase, more quickly than surface winds, allowing for some LLWS for a period between 04Z and 14Z Tuesday before surface winds align better with the low level jet. Ceilings will be on the decrease as our next round of precipitation approaches, but these should stay above 3000 feet above ground level at all sites except SLK and MSS, which may have a period of up and down cigs around 2500-3500 feet 12Z through 20Z Tuesday, a mix of SCT and BKN at times. Rain is forecast to arrive around 15Z-21Z Tuesday, moving west to east. Showers are expected to be overall light, though they could become heavier at times and with any rumbles of thunder. Confidence in timing of this heavy rain and/or thunderstorms is not high enough to specify in TAFs. Low level jet looks to strengthen again around 18Z-21Z and onwards, resulting in the return of some LLWS to several sites.

Outlook...

Tuesday Night: Mainly VFR, with local MVFR possible. Definite RA, Definite SHRA, Slight chance TSRA. Wednesday: Mainly MVFR, with local IFR possible. Definite RA. Wednesday Night: Mainly VFR, with local IFR possible. Likely RA, Chance SHRA. Thursday: VFR. Slight chance SHRA. Thursday Night: VFR. Slight chance SHRA. Friday: VFR. Chance SHRA. Friday Night: VFR. Slight chance SHRA. Saturday: Mainly VFR, with local MVFR possible. Chance SHRA.

MARINE

Southerly winds 10 to 15 knots are expected tonight, increasing to 15 to 25 knots around 2 AM - 4 AM Tuesday morning with gusts 25 to 35 knots and waves 1 to 3 feet. Winds then increase to around 20 to 35 knots 2 PM - 4 PM Tuesday, gusting 25 to 35 knots and waves building to 2 to 4 feet. Winds should subside back to 5 to 15 knots by around 4 PM - 6 PM Tuesday as steadier rain arrives. Waves also subside to around 1 to 3 feet Tuesday afternoon and evening.

BTV WATCHES/WARNINGS/ADVISORIES

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