Severe Thunderstorm Warning 41, NWS Burlington, VT

Area Forecast Discussion
National Weather Service Burlington VT
1145 AM EDT Thu Jul 21 2022

.SYNOPSIS...
Main weather threat today will be strong to severe thunderstorms
mainly from the Champlain Valley eastward. Temperatures will remain
uncomfortably warm today with heat index values generally from the
upper 80s to low 90s and values in the upper 80s expected to
continue through the weekend before appreciable cooling occurs early
next week. After dry conditions Friday and part of Saturday, the
next frontal system could bring another round of thunderstorms to
the region Sunday into Monday.

&&

.NEAR TERM /THROUGH FRIDAY/...

*Severe Thunderstorm Watch in Effect until 800 pm for Clinton
 and Essex Counties in New York, and all of Vermont.

* Heat index values will be 90-95 degrees today with some concerns
for heat illness for those outdoors.

As of 1145 AM EDT Thursday...Quick update to incorporate severe
storm potential wording per SPC Watch #479, in effect until 800
pm. Highest threat of severe storms should lie in this area,
generally along and east of a pre-frontal trough advancing
slowly east into the Champlain Valley currently.

Prior discussion...
Bottom line up front, everything remains on track for an active
day of strong to severe thunderstorms for the North Country. A
weak disturbance moved through overnight and brought cloud cover
to the region resulting in warm overnight low temperatures.
This system is beginning to exit the region with clearing
developing in it's wake. This should allow for rapid warming
over the next 1-3 hours before we see robust convection begin to
fire up as we reach convective temperatures and see increasing
low level shear. Based on the PWATs, we did mention heavy rain
for the storms today with this update although we do not
anticipate any hydro issues as storms should me moving around 40
to 45 mph this afternoon. Stay tuned for updates and potential
watch/warning issuance this afternoon.

Previous Discussion... A potent wave will be pushing through
the region today bringing strong to severe thunderstorms mainly
across Vermont. Current radar shows a couple of prefrontal lines
of showers across Adirondacks and the Saint Lawrence Valley.
These areas will become the focal point for convection later
this morning as temperatures rise with surface dew points in the
70s. Ample CAPE(1500-2500J/kg) and shear(30-40kts) coincident
with forcing will allow for strong updrafts. Hodographs are
generally straight, so multicells to bow structures still seem
the most likely mode with gusty winds and hail the primary
threats , but some discrete cells aren't out of the question
either; possibly at initiation before cells congeal into bows. A
lower potential of tornadoes seems reasonable given 100-200
0-1km helicity.

The first line will reach the Champlain Valley 11-Noon local time
with little in the way of inhibition. Expecting a rapid initiation
of cells with temps already in the upper 80s. However, cloud cover
and rainfall may limit some of the initial threat for severe cells in
the central Champlain Valley. As forcing pushes eastward towards
central and eastern Vermont, chances should increase for severe. The
second area of forcing will arrive in the early/mid afternoon
bringing another round of thunderstorms. The CAPE environment should
be slightly less favorable for stronger storms with 1000-1500J/kg.
Should some areas be missed by earlier convection and break out into
the sun, localized CAPE would be higher and supportive of a stronger
cell or two.

By tonight, both waves will be east of Vermont with the area under
some subsidence. For Friday, conditions will be drier, but CAMs do
note a couple of disturbances in vorticity fields. Some showers and
an isolated thunderstorm may be possible over terrain.

Heat: Temperatures will be on the rise again today with highs in the
upper 80s and heat index values 88-95 degrees. Conditions will be
uncomfortable again, but should fall short of advisory criteria.
Still, those with outdoor plans should carry extra water and limit
activity during the hottest part of the day. Also, it's prudent to
have a plan for lightning given the threat of thunderstorms today.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 402 AM EDT Thursday...Large scale pattern indicates fast
westerly flow aloft acrs cwa during this time frame with building
instability aft 18z on Sat. This developing instability axis acrs
northern NY, along with pw values near 1.5" and weak embedded vort
could spark a few showers/storms. Main focus with limited sfc
convergence would be acrs the eastern Dacks or associated with Lake
Ontario lake breeze impacting the southern SLV. The bigger story on
Saturday wl be the very warm temps again, as NAM/GFS suggest progged
925mb temps btwn 23-24C, supporting highs mid 80s to lower 90s. Wl
trend toward the warmer side of guidance for highs on Sat. Soundings
support some slightly drier air mixing toward the sfc on Sat aftn,
with dwpts dropping back into 50s to near 60F, which should prevent
areas reaching heat advisory criteria. Lows generally in the mid 50s
to mid 60s on Friday night and again on Saturday night with some
upper 60s possible in the CPV on Sat night, due to increasing
southerly flow.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 402 AM EDT Thursday...Another active day with strong to severe
storms possible on Sunday, along with very warm and humid
conditions. Mid/upper lvl pattern continues to support a very fast
westerly flow with an embedded s/w impacting the region on Sunday.
Progged 500mb wind fields are btwn 45 and 60 knots, while 700mb
winds are in the 45 to 55 knots, creating 0 to 6 km shear 45 to 55
knot range. Some question on amount of instability with latest
guidance indicating the potential for some mid/upper lvl convective
debris clouds. However, thinking with temps warming well into the
80s with sfc dwpts in the 60s, CAPE values should response into the
1500 to 2000 J/kg, supporting the threat for organized convection
again on Sunday aftn. We will continue to monitor timing of boundary
and energy in the jet stream winds aloft for helping to determine
how robust convection can become. In addition, pws in the 1.7 to 1.9
range and boundary paralleling the mid/upper lvl flow, localized
heavy rainfall and training of convection wl need to be monitored
also. By early next week mid/upper lvl trof develops acrs the NE
CONUS and best instability and moisture sags to our south. Also,
good news much less humidity arrives by early next week, as flow
becomes northwest and drier air in central Canada advects into our
cwa, while pw values fall <1.0". Have lingering pops on Monday
morning, but Tuesday into Weds should be dry with highs mid 70s to
lower 80s and lows back into the upper 40s to lower 60s by Tues and
Wed mornings.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday...Currently VFR, with a line of thunderstorms
tracking towards MSS which could mix up to 40kts of winds to the
surface given LLjet above the surface. Timed this convection in
generally 0730-09Z. LLWS will continue to be an issue for area
terminals as aforementioned LLjet tracks over the North Country.
Have this line washing out as it progresses eastward towards
SLK, but SLK may end up having a TS around 09-10Z. IFR Vis is
currently being presented as haze at SLK - either the sensor is
mischaracterizing mist, or there is smoke present, or the
present weather sensor is experiencing a malfunction. For now,
carrying BR until further diagnosis is possible. Winds are
trending southerly, and will remain steady near 5 knots and then
begin to gradually increase after 06Z. Winds aloft will be
increasing a bit more quickly, especially over northern New
York, and noted some LLWS at KMSS and KSLK through about 09Z.
After 09Z, winds should increase to 9 to 14 knots with gusts 16
to 24 knots, though a bit longer to reach these speeds at KEFK
and KMPV. Showers and an isolated thunderstorm will approach
KMSS and KSLK about 09Z to 11Z, and move east into Vermont about
15Z to 17Z. Additional storms will develop near or east of KSLK
about 19Z to 22Z, moving east of the region about 00Z Friday.
With any of these rounds, there could be a few storms capable of
strong, gusty winds, frequent lightning, and heavy rain that
reduces visibility. At this time, it seems storms will not merge
into clusters or lines, but this possibility is not out of the
question. So most terminals have a mention of VCTS, but have
included in a tempo for KEFK, KMPV, and KRUT where the chances
will be highest, but the activity could be hit or miss. As the
front shifts east, winds become southwesterly, remaining about 6
to 10 knots into 00Z Friday.

Outlook...

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

&&

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

&&

SYNOPSIS...Boyd
NEAR TERM...JMG/Clay/Boyd
SHORT TERM...Taber
LONG TERM...Taber
AVIATION...Boyd

Hazardous Weather Outlook
National Weather Service Burlington VT
424 AM EDT Thu Jul 21 2022

NYZ026>031-034-035-087-VTZ001>011-016>021-220830-
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-
424 AM EDT Thu Jul 21 2022

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

.DAY ONE...Tonight.

Continued heat concerns with heat index values 88-95 degrees, and
potential for strong, possibly severe, thunderstorms from late this
morning through the afternoon mainly in Vermont. Gusty winds and hail
will be main threats, but a rare tornado cannot be ruled out.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Warm temperatures continue through the weekend with another round of
thunderstorms possible on Sunday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service Burlington VT
1255 PM EDT Thu Jul 21 2022

VTZ011-019-211745-
Eastern Rutland VT-Western Rutland VT-
1255 PM EDT Thu Jul 21 2022

...A strong thunderstorm will impact portions of southeastern Rutland
County through 145 PM EDT...

At 1255 PM EDT, Doppler radar was tracking a strong thunderstorm near
Hartford, moving northeast at 35 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

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

Locations impacted include...
Rutland, Pawlet, Mount Holly, Poultney Village, Mount Tabor,
Tinmouth, Shrewsbury, Rutland City, Middletown Springs, Wallingford,
Mt. Holly, Mt. Tabor, Danby, Lake St. Catherine, Rutland - Southern
Vermont Airport, Poultney, Clarendon, West Rutland, Ira and Wells.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
southern Vermont.

&&

LAT...LON 4330 7298 4331 7325 4352 7325 4371 7292
      4343 7280 4331 7293 4330 7294 4330 7297
      4329 7298 4329 7299
TIME...MOT...LOC 1655Z 237DEG 31KT 4337 7332

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Haynes

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>