textproduct: Burlington

WHAT HAS CHANGED

As of 538 AM EDT Saturday...

The Flood Warning has been canceled this morning as rain moved out of the region. Moderate to heavy rainfall in showers and isolated thunderstorms today may still lead to isolated flooding, primarily across the northern Adirondacks and north- central Vermont.

KEY MESSAGES

As of 252 AM EDT Saturday...

1. Moderate to heavy rainfall today may lead to isolated flooding, primarily across the northern Adirondacks and north- central Vermont. Showers and thunderstorms today and Sunday are expected to produce an additional 0.25-1.25" across northern New York and Vermont.

2. Another system anticipated to bring more rain early next week has the potential to produce localized moderate to heavy rainfall in southern Vermont.

3. Unsettled pattern prevails for mid to late week with temps at or slightly below normal.

DISCUSSION

As of 252 AM EDT Saturday...

KEY MESSAGE 1: Vertically stacked low pressure stretched across the Canadian maritimes will continue swinging shortwaves through the Northeast today with showers ongoing across much of northern New York and Vermont early this morning. In the last 6 hours, reports of rain have been 0.50-1.00", bringing us to 48 hour totals approaching 4.00 inches in parts of north-central Vermont. This is especially hazardous given we still have hours before sunrise, and the dangers of flooding are harder to recognize in the dark. A Flood Warning has been issued for portions of Addison, Washington, Chittenden, Franklin, and Lamoille counties of Vermont through 715 AM. We continue to monitor the potential for any isolated flooding issues that may arise today, and several river rises are anticipated. Multiple rounds of showers and thunderstorms are forecast today and Sunday, with additional precipitation amounts as high as 0.25-1.25" total, though some spots will likely see higher amounts depending on where thunderstorms occur. The widespread precip and clouds this weekend will likely keep highs below seasonal normals around the 60s and 70s and lows in the upper 40s and 50s. These temperatures might feel a touch cooler today with wind gusts 15-25 knots out of the west and northwest.

KEY MESSAGE 2: Upper level closed low pressure will cross from Ontario to Quebec sometime on Monday as a surface low pressure moves through the Ohio Valley and mid-Atlantic. The majority of guidance is now showing likely measurable precipitation for the central Adirondacks, south-central Vermont, and the Northeast Kingdom sometime Monday and Monday night, though the exact track of the surface low will determine just how far north we can get precipitation and how much precipitation will occur. Latest trends bring the system slightly more south, slightly lowering amounts. Most likely precip amounts run around 0.05-0.20" in far northern and northwestern New York while areas south and east can be anywhere from 0.20-1.20", the highest of those amounts in southern and south-central Vermont. At this time, there is also a brief possibility of a thunderstorm or two in southern Vermont on Monday afternoon. Temperatures Monday are expected to reach the 70s for most areas, though much will depend on how far north the precipitation reaches. If the storm tracks farther north, we could see temperatures struggle to reach these values. If it tracks farther south, temperatures would be more likely to exceed these values.

KEY MESSAGE 3: Mid/upper lvl trof wl cont acrs the NE CONUS into the central Great Lakes for days 4 thru 7. This wl keep the heat and humidity mainly south of our cwa, along with the best instability parameters most of next week. Timing of individual s/w's and associated sfc low pres tracks are challenging in fast/progressive flow aloft, especially late next week. After departing rain showers on Tues, weak high pres should result in a mostly dry Weds acrs our cwa. Next system arrives Thurs/Friday as northern stream energy moves from the Great Lakes into the NE CONUS. Still plenty of spread in magnitude and evolution of this system, but general idea of increasing chances for showers and thunderstorms looks good. Highest potential based on latest WPC fcst is late Thurs into Friday. Given recent rainfall and saturated soils acrs most of northern NY into central/northern VT, the potential for flooding wl need to be monitored as we move forward. Additional s/w energy and sfc low pres arrive for next weekend, with the potential for more showers and thunderstorms. The overall pattern supports chances for precip every couple of days, as mean trof remains acrs our cwa. Temps mostly in the mid 70s to lower 80s for mid week, before cooling back into the upper 60s to mid 70s by late next week, with lows mid 50s to mid 60s.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/

Through 12Z Sunday...Flight conditions have been bouncing between MVFR and VFR at many of our taf sites this morning, while IFR ceilings continue at SLK. Based on sounding data and westerly upslope flow, thinking ceiling remain IFR thru 15z, before lifting by 16 or 17z to MVFR. Outside of SLK, thinking mostly a mix between MVFR and VFR expected with highest potential for consistent MVFR cigs at MPV and EFK. Also, scattered showers with embedded rumbles of thunder will increase in areal coverage late this morning into the afternoon hours. The heavier showers will be capable of brief IFR vis/cigs, but mostly MVFR conditions will prevail in any shower or thunderstorm activity. Conditions trend back toward MVFR most sites tonight with IFR likely at SLK by 04z. Winds are 5 to 15 knots with some localized gusts 15 to 20 knots expected today, especially MSS/MPV and EFK.

Outlook...

Sunday: Mainly VFR, with local MVFR possible. Likely SHRA, Chance TSRA. Sunday Night: VFR. NO SIG WX. Monday: VFR. Chance SHRA. Monday Night: Mainly VFR, with local MVFR possible. Chance SHRA. Tuesday: Mainly VFR, with areas MVFR possible. Chance SHRA, Slight chance TSRA. Tuesday Night: VFR. NO SIG WX. Wednesday: VFR. Slight chance SHRA, Slight chance TSRA.

BTV WATCHES/WARNINGS/ADVISORIES

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