textproduct: Burlington

WHAT HAS CHANGED

As of 248 PM EDT Tuesday...

No significant changes for the afternoon forecast.

KEY MESSAGES

As of 248 PM EDT Tuesday...

1. A brief warm spell is expected through the end of the work week, with the warmest temperatures expected Thursday and Friday.

2. Showers are expected this weekend, including possible scattered thunderstorms on Saturday and steadier rain on Sunday, as temperatures cool slightly. Dry and seasonable weather will likely follow for early next week.

DISCUSSION

As of 248 PM EDT Tuesday...

KEY MESSAGE 1: The second half of the week will be markedly different from the first; a building ridge will bring warming temperatures and a return of more seasonal early summer conditions. Temperatures will peak at their warmest on Thursday and again on Friday, when highs are forecast in the 80s throughout the area. Dewpoints will gradually tick up through the end of the week, but will remain in the 40s to mid 50s...or generally in a dry to comfortable range. Forecast soundings continue to show a dry layer in the mid-levels through Thursday, which will allow afternoon dewpoints to fall as the drier air is mixed to the surface during the mid-day hours. The lower humidities will keep overall heat risk low, but given the recent cooler conditions, individuals sensitive to heat should prepare accordingly for the brief warm spell that will last through Friday.

KEY MESSAGE 2: Following a dry workweek, unfortunately we are looking at rain over the weekend associated with the next trough of low pressure moving eastward through our region. While there are important location and timing differences amongst model guidance, signals for rain are strong with about a 90-95% chance of seeing some rainfall over the weekend. Generally chances of rain ramps up Friday night into Saturday with greater chances reaching into the 50 to 70% range for much of the region between 2 and 8 PM Saturday. This rain is accompanied by a 20-30% chance of thunder, associated with modestly high chances of Surface Based CAPE exceeding 500 J/kg. Currently the most favorable area for thunderstorms is over northern Vermont, but this is a sharp shift northward from previous model cycles, pointing to large spatial uncertainty.

At this time, any strong thunderstorm potential looks very low per dynamical and statistical guidance, limited by deep layer shear most likely only in the 25 to 30 knot range. We'll keep an eye on trends as we approach the weekend, as the large scale pattern with low pressure passing to our north and at least modest instability and moisture ahead of a cold front does suggest potential for scattered thunderstorms. Rainfall amounts, especially given several dry days ahead of this event, do not look concerning at this time with regards to flood risk, but localized heavy rain will be possible with any thunderstorms followed by additional steadier/lighter rain on Sunday.

Temperatures, relative to normal, will be mildest to start the longer range period Friday night/Saturday morning given moist southern flow and lack of rain cooled air. Signals for unusual warmth are fairly weak, but consistent with most likely low temperatures in the low to mid 60s in the Champlain Valley and Adirondacks. Where winds in these scenarios tend to be lighter across central/eastern Vermont, this signal is muted. Otherwise, a cooling trend is expected moving from Saturday into Sunday. Highs Saturday in the warm sector of the low pressure system are favored to reach the 80s one more time across the Champlain Valley and Upper Valley. Areawide, highs Sunday look about 10 degrees lower due to a combination of northerly flow and potential for steadier rain as low pressure tracks through the region. Note temperatures will be heavily influenced by where any persistent rain falls during the day. With a seasonably weak thermal gradient tied to the frontal boundary, once the precipitation and clouds depart behind the system, we're looking at a rebound in temperatures for Monday with seasonable temperatures trending above normal for Tuesday.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

Through 18Z Wednesday...VFR flight conditions expected through the period. While skies will be mainly clear and winds light overnight, moisture appears to be lacking to promote fog based on yesterday's observations and continued advection of drier air, evidenced by falling dew points this afternoon into the low and mid 30s accordance with mixing of very dry air aloft. As such, statistical chances of fog even at our more fog prone sites, including SLK and MPV are very low (currently about 5% and peaking between 9 and 10Z).

Otherwise, we are currently seeing gusty winds due to said mixing, with most sites remaining northerly/northwesterly with peak gusts in the 15 to 22 knot range. These winds will gradually subside through 21Z and then sharply fall off between about 23 and 01Z. Winds then will remain light/terrain driven overnight, with only a 4 to 8 knot wind favored after sunrise as the center of high pressure builds in from the west.

Outlook...

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

CLIMATE

Temperatures will be approaching daily record maximums on Thursday. At this time, Plattsburgh (PBG) has the greatest likihood of reaching its current record of 88 degrees set on June 4th, 1967.

BTV WATCHES/WARNINGS/ADVISORIES

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