Flash Flood Warning 1, NWS Burlington, VT

Area Forecast Discussion
National Weather Service Burlington VT
323 PM EDT Sat May 17 2025

.SYNOPSIS...
Scattered strong, potentially severe, thunderstorms will move
through the North County this afternoon and evening with potential
for damaging winds, large hail, very heavy rainfall, and dangerous
lightning. These storms will pass this evening with low pressure
slowly moving through the region Sunday through Monday with much
cooler temperatures and continued chances of rain.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
As of 316 PM EDT Saturday...

* Severe Thunderstorm Watch in effect through 8PM. Multiple
  severe warned thunderstorms have occurred with reports of
  downed trees and up to golf ball size hail.

The atmospheric setup is ideal for isolated to scattered strong
thunderstorms this afternoon with 1000-2000 J/kg CAPE and ample
shear. Storm modes will be mixed discreet supercell and multi-
cellular lines. While chances are low, can't rule out a rare
tornado. Wetbulb zero heights are near ideal for large hail as well
with several reports of 1.75 inch hail already. These storms will
track east through the afternoon with one more wave of forced
showers/storms possible later this evening. The evening wave may not
produce as many strong cells due to the environment being worked
over from earlier storms, but can't rule out some stronger elements
either. Finally, the last concern will be flash flooding. Multiple
rounds of heavy rainfall will increase susceptibility to flooding in
heavier storms. Locations like Cambridge, VT have seen ample rainfall
and are experiencing minor flooding; any further rain from a strong
thunderstorm will likely lead to localized flash flooding.

Temperatures cool sharply tonight into Sunday with highs in the 50s
and 60s. With the cold core of the low overhead, more showers are
anticipated, but no severe thunderstorms since temperatures cool off
dramatically. Upper low drags northeastward Sunday night pulling
rain with it. Low's in the mid 30s to low 40s are anticipated.

&&

.SHORT TERM /MONDAY/...
As of 316 PM EDT Saturday...Vertically stacked low pressure will
hover over Nova Scotia to start the workweek, drawing in cooler air
from the north and northwest on Monday. Lingering moisture will help
trigger additional showers, mainly across the far northern
Adirondacks, northern Greens, and the Northeast Kingdom.
Northwesterly winds will be breezy with gusts up to 15-25 knots,
higher on the mountaintops with a weak low level jet overhead. NW
winds, showers, and increased cloud cover will result in highs
struggling to reach the upper 40s to upper 50s in the afternoon. As
we head into the overnight hours Monday night, showers should taper
off as drier air noses in from the west, though if showers linger
long enough to coincide with colder temperatures (lows falling into
the mid 30s to mid 40s), we could see some snow mixing in at the
highest elevations. No accumulation is expected. Winds will continue
out of the northwest with perhaps occasional gusts but overall
decrease at night.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
As of 316 PM EDT Saturday...The pattern is forecast to stay active
and wet into next weekend, though models continue to depict a range
of varying scenarios and storm tracks. Precip is possible each day.
Due to the above normal precipitation chances this week, we'll also
see highs in the 50s/60s and lows in the 40s, keeping conditions
chilly.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
Through 18Z SUNDAY...Mix of IFR to VFR given periods of
thunderstorms. Some of these storms will be capable of producing
large hail and damaging winds as well. Most favorable time for
storms will be 18-22Z with chances falling sharply after 00Z.
Erratic gusty winds are expected with periods of continuous
lightning to impact most terminals. After 00Z CIGs likely
become a mix of VFR/MVFR before sagging to MVFR/IFR by 12Z with
chances of showers increasing Sunday.

Outlook...

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

&&

.HYDROLOGY...
Several rounds of heavy rainfall have occurred and will continue
to occur through this evening as several troughs strongly force
convection. Given storm mode of mix supercell/multicell line,
heavy rainfall from individual cells, training cells, and
multiple rounds of thunderstorms will result in isolated flash
flooding. Highest chances of this will be from the Adirondacks
to locations just east of the Green Mountains. Conditions
improve overnight with troughs passing eastward.

&&

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

&&

SYNOPSIS...Boyd
NEAR TERM...Boyd
SHORT TERM...Storm
LONG TERM...Storm
AVIATION...Boyd
HYDROLOGY...

Hazardous Weather Outlook
National Weather Service Burlington VT
238 PM EDT Sat May 17 2025

NYZ026>031-034-035-087-VTZ001>011-016>021-181845-
Northern St. Lawrence-Northern Franklin-Eastern Clinton-
Southeastern St. Lawrence-Southern Franklin-Western Clinton-
Western Essex-Eastern Essex-Southwestern St. Lawrence-Grand Isle-
Western Franklin-Orleans-Essex-Western Chittenden-Lamoille-Caledonia-
Washington-Western Addison-Orange-Western Rutland-Eastern Franklin-
Eastern Chittenden-Eastern Addison-Eastern Rutland-Western Windsor-
Eastern Windsor-
238 PM EDT Sat May 17 2025

...SEVERE THUNDERSTORM WATCH 277 IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for northern New York, central
Vermont, northeast Vermont, northwest Vermont and southern Vermont.

.DAY ONE...This afternoon and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Severe Thunderstorm Watch.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Preliminary Local Storm Report
National Weather Service Burlington VT
302 PM EDT Sat May 17 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0250 PM     Tstm Wnd Dmg     East Charlotte          44.32N  73.19W
05/17/2025                   Chittenden         VT   Trained Spotter

            Tree down near Sheehan Green with Nichel hail

&&

Event Number BTV2500935

TD

Preliminary Local Storm Report
National Weather Service Burlington VT
313 PM EDT Sat May 17 2025

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0255 PM     Tstm Wnd Dmg     2 NE Peasleeville       44.62N  73.65W
05/17/2025                   Clinton            NY   Emergency Mngr

            Tree down on power lines.

&&

Event Number BTV2500936

TD

Special Weather Statement
National Weather Service Burlington VT
313 PM EDT Sat May 17 2025

NYZ028-035-VTZ001-002-005-172000-
Eastern Clinton NY-Eastern Essex NY-Western Franklin VT-
Grand Isle VT-Western Chittenden VT-
313 PM EDT Sat May 17 2025

...STRONG THUNDERSTORMS WILL IMPACT EAST CENTRAL CLINTON...
NORTHEASTERN ESSEX...GRAND ISLE...NORTHWESTERN CHITTENDEN AND
SOUTHWESTERN FRANKLIN COUNTIES THROUGH 400 PM EDT...

At 313 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Chazy to near South Hero to near
Willsboro. Movement was east at 30 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Young Island, Wilcox Point, Scott Point, Hazen Point, Sunset Island,
West Milton, Malletts Bay, Hen Island, Winooski, Conner Bay, Kellogg
Island, Grand Isle State Park, Allens Bay In Clinton County, Cloak
Island, Hoyt Point, Point Of The Tongue, Marble Island, Monty Bay,
Monty Point, and Martin Bay.

This includes the following highways...
 Interstate 87 between mile markers 157 and 163.
 Interstate 89 between mile markers 88 and 112.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

If on or near Lake Champlain, get out of the water and move indoors
or inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
northern New York...and northwestern Vermont.

&&

LAT...LON 4488 7315 4469 7302 4446 7318 4444 7344
      4465 7336 4483 7350
TIME...MOT...LOC 1913Z 264DEG 25KT 4483 7340 4466 7326 4446 7336

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Duell

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