textproduct: Burlington

WHAT HAS CHANGED

As of 242 PM EDT Thursday...

No significant changes to the current forecast.

KEY MESSAGES

As of 240 PM EDT Thursday...

1. Breezy conditions today will usher in dry weather for most of the weekend.

2. A weak cold front will pass east through the region on Sunday and bring breezy conditions, warm temperatures, and scattered showers and thunderstorms.

3. A progressive pattern will support periods of rain showers with a trough favored to move through Tuesday night into Wednesday.

DISCUSSION

As of 240 PM EDT Thursday...

KEY MESSAGE 1: Fast westerly flow is bringing in dry air across Vermont and northern New York. Temperatures currently range in the upper 60s to mid 70s. A well mixed boundary layer has resulted in 20-30 mph gusts across the forecast area, and even a few peak gusts around 35- 40 mph. The expected cold front is still off to our north. Radar shows very little activity, and strong 700mb layer inversion with low to mid-level drying will permit only a rogue shower, if any, as the front crosses southeast. Overnight, winds will slacken, but not completely die off. Additionally, there will be some high clouds initially. This will result in slow cooling brought on by the cold advection early this evening, and then a sharper drop before sunrise when radiational cooling will become more dominant. Overnight low temperatures should settle into the lower 40s to lower 50s, with perhaps a spot upper 30 for the perennially cold Adirondack Airport.

Friday will be nice and cool with beautiful weather with mid 60s to lower 70s. Good radiational cooling will ensue overnight, but surface high pressure will amble offshore, and a little bit of southerly return flow will follow. Another night of lower 40s to lower 50s, and probably a few additional upper 30s in colder hollows appears most likely. Saturday will be similar, but warming solidly into the 70s with the southerly flow. Then Saturday night will be more humid with warmer overnight lows in the mid 50s to mid 60s.

KEY MESSAGE 2: Sunday will start warm and humid as a narrow tongue of Gulf moisture reaches the forecast area. There's a fairly strong upper low moving along Hudson Bay, but its attendant surface reflection will be in far northern Quebec Province. So the cold front extending south of the surface low will be quite elongated over our region. A lee side trough enhanced by diurnally driven convection will track along the Mid-Atlantic. It will keep the bulk of better instability and moisture away from our region, while we only have marginal synoptic forcing out of the stretched out frontal boundary. Still, good surface heating will push temperatures into the mid 70s to lower 80s, and this will result in about 750-1250 J/kg of CAPE. A few showers and thunderstorms seem reasonable, but the GFS simulated IR satellite doesn't hint at the potential for strong updrafts with a lack of cold cloud tops. Shear does appear to be on the high side at 45-50 knots. Given weak forcing, only modest instability, and dry air entrainment, that shear might just be too much. We'll keep an eye, but the most likely case is garden variety scattered showers and thunderstorms with breezy conditions ahead of the front.

KEY MESSAGE 3: 500 mb flow in the mid-high latitudes are favored to be mainly zonal with Arctic air trapped well north of the region. Fast- moving troughs will be moving through this flow with model trends shifting to a later approach of Tuesday's wave. As such, chances were lowered Tuesday afternoon and shifted later into Tuesday night/Wednesday as the trough moves through. Some models keep a stalled surface boundary over the region which will have implications to temperatures and precipitation chances going forward. Should this come to fruition, a wetter period would be possible along/south of this boundary. Either way, another wave is projected to move through Thursday into the end of the work week with more chances of afternoon showers and maybe a rumble of thunder.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

Through 18Z Friday...Southwest to west winds 10 to 15 knots with gusts 15 to 30 knots are ongoing as a secondary cold front drops across our taf sites. By this evening additional mid level clouds and a few sprinkles are possible as boundary layer mixing continues. Surface winds slowly abate after 22-00Z, but flow will remain above a very shallow inversion. These factors should limit the areal coverage of fog and IFR or lower conditions, but SLK/MPV and EFK will need to be watched, given recent rainfall. Winds remain out of the west to northwest, but lighter than today, after 12Z Friday with VFR conditions prevailing.

Outlook...

Friday Night: VFR. NO SIG WX. Saturday: VFR. NO SIG WX. Saturday Night: Mainly VFR, with areas MVFR possible. Chance SHRA. Sunday: Mainly VFR, with local IFR possible. Chance SHRA, Slight chance TSRA. Sunday Night: Mainly VFR, with local MVFR possible. Slight chance SHRA. Monday: Mainly VFR, with local MVFR possible. NO SIG WX. Monday Night: VFR. NO SIG WX. Tuesday: VFR. Windy with gusts to 30 kt. Chance SHRA, Slight chance TSRA.

MARINE

West-northwest to northwest winds across Lake Champlain have mainly been between 10 to 20 knots. A few gusts at or above 25 knots have occurred. Waves will likely remain around 1 to 3 feet today. Winds will become weaker this evening around 5 to 15 knots out of the northwest.

BTV WATCHES/WARNINGS/ADVISORIES

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