Marine Weather and Tide Forecast for Willsboro, NY

KEY MESSAGES
As of 238 AM EDT Tuesday...

1. Chances for scattered showers start early Wednesday and persist through Friday.

2. Building heat and humidity through Friday.

3. Chances for showers and a few thunderstorms return over the weekend with temperatures cooling towards normal by early next week.

DISCUSSION
As of 238 AM EDT Tuesday...

KEY MESSAGE 1: After a dry and sunny day today, the weather pattern turns more unsettled starting tonight. A northern stream shortwave approaching from the west this afternoon/evening will bring some scattered showers to our forecast area beginning early Wednesday.
With multiple shortwaves moving through, the chances for scattered showers continue through Friday. This timeframe will not be a washout by any means, but do expect some periods of showers with some embedded rumbles of thunder possible, especially during the afternoon hours. Chances for severe weather during this timeframe is relatively low...limited by lack of shear, marginal instability, and lack of strong or organized forcing. The overall pattern is rather disorganized until a front finally sweeps through late Friday into Friday night, providing a focus for more organized and steady precipitation overnight. Of all the days this week, Friday has the better potential for severe, especially if we were to destabilize ahead of the frontal passage, but timing doesn't look to be lining up favorably for severe storms at this point.
We will continue to monitor.

KEY MESSAGE 2: Temperatures today and tomorrow will be relatively seasonal, but will trend warmer with increasing humidity Thursday and Friday. Given the overall unsettled weather pattern with scattered showers and clouds moving through, have continued to hedge forecast temps towards MOS guidance...slightly lower than the NBM. Friday continues to look like the warmest day, when temperatures will reach into the upper 80s to lower 90s. At the same time, dewpoints will tick upwards into the mid to upper 60s as Gulf moisture wraps up and around high pressure over the western Atlantic. As a result, expect the airmass to feel noticeably more muggy late week. Heat indices will reach into the low to mid 90s on Friday in the Champlain Valley, Saint Lawrence Valley, and Connecticut River Valley. In addition to the increasing humidity and warmer daytime temperatures, overnight lows will also be on the warmer side...falling only to the low to upper 60s. This will limit overnight recoveries, and increase heat risk to any vulnerable populations.

KEY MESSAGE 3: Mean longwave troughing is favored to shift towards the Northeast and eastern Canada over the weekend into early next week.
This pattern will promote periods of showers and frontal passages.
One such front is currently projected to move through Friday night into early Saturday. Differing guidance are a little split on the timing, but most models have the expectation of a period of height falls supporting increased instability and potential for a few thunderstorms. This doesn't look to be a complete washout for the weekend however. The front will also bring cooler surface temperatures with highs likely trending back towards the mid/upper 70s by early next week. The region is expected to remain under the base of a broad longwave trough into early next week with continued shower chances. With flow aloft somewhat zonal, faster flow aloft will push a series of weaker variety troughs through. Periodic breezes in excess of 20 mph are possible in this flow pattern especially in northern New York where westerly flow stacks along the northern slopes of the Adirondacks down to the Highway 11 corridor.

AVIATION /00Z TUESDAY THROUGH SATURDAY/
Through 00Z Wednesday...VFR conditions will degrade to IFR at MPV/SLK where crossover temperatures will likely be crossed this morning despite drier afternoon RH yesterday. Otherwise, only looking at some mist at MSS where conditions will be close and could have just enough mixing at sunrise to squeeze out some MVFR vis. Elsewhere, conditions will remain VFR with winds remaining generally light. Lake breezes will set up today given the sharp temperature rise expected with a westerly component in the afternoon for BTV and southerly at PBG as southeasterly lake breeze balances with wester flow aloft.

Outlook...

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

CLIMATE
Temperatures will approach record highs on Friday, June 12th.

Max Temp Records Date KBTV KMPV K1V4 KMSS KPBG KSLK 06-12 94|2017 88|2017 91|2017 89|2005 94|2017 90|1933

High Min Temp Records Date KBTV KPBG KSLK 06-12 71|2017 67|2017 62|1996



BTV WATCHES/WARNINGS/ADVISORIES
VT...None.
NY...None.