Severe Thunderstorm Warning 210, NWS Denver/Boulder, CO

Area Forecast Discussion
National Weather Service Denver/Boulder CO
544 PM MDT Tue Jun 30 2026

.KEY MESSAGES...

- Critical fire weather conditions will be present in the high
  country today due to warm, dry and windy conditions.

- A couple strong storms possible across far northeastern Colorado
  late this afternoon/evening.

- Mainly dry Wednesday through Friday with elevated to critical
  fire conditions across much of the area.

&&

.DISCUSSION /Through Tuesday/...
Issued at 248 PM MDT Tue Jun 30 2026

It is sunny, dry, and breezy across much of Colorado this afternoon.
A shortwave currently sitting over Utah will continue to track
northeast into northern Colorado and Wyoming, and flow aloft is now
SSW. At the surface, strong southeasterly flow is advecting
dewpoints in the low 40s into north central Colorado as far west as
the I-25 corridor. Current satellite imagery shows cumulus cloud
coverage already increasing over the foothills. With DCAPE values in
the 1000-1500 J/kg range, virga showers are still on track to
develop this afternoon. Wind gusts up to 50-55 mph will be
possible with the outflows of the strongest dry microbursts. High-
res model guidance initially favors the northern I-25 corridor for
the development of high-based showers between 4pm and 6pm. The
far northeast plains of Colorado will have a better chance to see
a strong thunderstorm as high-based showers move into an
environment with higher precipitable water (PW ~1.00") and MLCAPE
in the early evening. Another shortwave will graze northern
Colorado tomorrow afternoon bringing a chance (20%-30%) for a few
high based showers over our northeast CWA, although the moisture
content of the airmass in place will be much lower than today's
(PWs <0.50").

A longwave ridge over the eastern half of the U.S. will continue
to block the synoptic pattern through at least the end of this
week when flow is expected to become more zonal. Winds aloft
remain SSW/SW tomorrow and Thursday, becoming weaker as the week
progresses. While there is no strong signal for a pattern change
over the next couple days, a weak disturbance appears to arrive
late Friday into Saturday. Model guidance suggests a lee cyclone
developing over eastern Colorado Saturday afternoon, aiding the
transport of enough Gulf moisture for at least a few isolated
showers over the northeast Colorado plains. Uncertainty remains
regarding thunderstorm chances for the weekend at this time. Dry
conditions return by early next week with slightly above average
temperatures.

&&

.AVIATION /00Z TAFS through 00Z Thursday/...
Issued at 540 PM MDT Tue Jun 30 2026

A couple narrow bands of southwest-northeast oriented convection
are still sitting across the Denver metro between the terminals.
While not overly impressive on satellite, some of the stronger
convective cells have produced some lightning, and it appears
probable that this will continue at times over the next hour or
two. Smoke is also slowly starting to drift towards the terminals,
with satellite suggesting some increased concentrations closer to
APA. We don't expect this to impact surface visby but can't rule
out some slant-range visibility impacts through sunset tonight.

Winds behind the convection this evening should weaken and slowly
turn from the north to a weak westerly direction, before settling
on drainage later tonight. It looks likely that we'll see another
Denver Cyclone develop during the day Wednesday, with most
guidance lifting that cyclone towards DEN between roughly 21-03z.
Therefore, confidence in any particular direction during the
afternoon/evening hours at DEN/APA is rather low... with
east/northeast or gusty northwesterly winds possible depending on
the strength and proximity of the cyclone.

&&

.FIRE WEATHER...
Issued at 248 PM MDT Tue Jun 30 2026

Critical fire weather conditions are possible over the high terrain
this afternoon with winds gusting up to 30 mph and humidities in the
teens. Elevated fire weather conditions are also occurring over
the Palmer Divide this afternoon with winds gusting as high as 40
mph, although humidities have remained in the 20%-30% range due to
the strong southeasterly flow in place.

Winds will become weaker tomorrow, just below the threshold for Red
Flag issuance. However, brief periods of gusty winds up to 30 mph as
well as humidities in the low teens will create elevated fire
weather conditions and spotty critical conditions in some areas. The
Palmer Divide will likely be closest to meeting critical fire
weather criteria due to the development of a Denver cyclone in the
vicinity, which could strengthen wind gusts (up to 35 mph) for at
least a brief period of time.

For Thursday and Friday, winds will be generally light (< 20 mph)
although humidities will drop into the single digits each afternoon,
particularly over the high terrain. Therefore, widespread elevated
fire weather conditions are expected through the foreseeable future,
with localized areas of critical fire conditions over the mountains
Friday afternoon.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM MDT this evening for COZ211>214-
216>218.

Fire Weather Watch from Wednesday afternoon through Wednesday
evening for COZ212-214-216-241.

&&

DISCUSSION...AA
AVIATION...Hiris
FIRE WEATHER...AA

Special Weather Statement
National Weather Service Denver CO
258 PM MDT Tue Jun 30 2026

COZ038-043-302145-
Larimer County Below 6000 Feet/Northwest Weld County CO-Central
and South Weld County CO-
258 PM MDT Tue Jun 30 2026

...A SHOWER WILL IMPACT WEST CENTRAL WELD AND SOUTHEASTERN LARIMER
COUNTIES UNTIL 345 PM MDT...

At 258 PM MDT, Doppler radar was tracking a shower near Johnstown, or
9 miles west of Greeley, moving northeast at 40 mph.

HAZARD...Wind gusts up to 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
  Greeley, Windsor, Evans, Johnstown, Milliken, Berthoud, Eaton,
  Severance, Ault, Pierce, Timnath, Lucerne, New Windsor Reservoir,
  Kelim, Black Hollow Reservoir and Fort St Vrain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

If on a lake, get out of the water and secure loose items. Boaters
can expect strong gusty winds and locally higher waves. Boaters
should seek safe harbor immediately.

&&

LAT...LON 4034 10506 4066 10495 4063 10456 4058 10459
      4058 10463 4054 10463 4027 10481 4027 10508
TIME...MOT...LOC 2057Z 204DEG 36KT 4037 10490

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

BRQ

Special Weather Statement
National Weather Service Denver CO
428 PM MDT Tue Jun 30 2026

COZ040-043-302315-
North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County CO-Central and South
Weld County CO-
428 PM MDT Tue Jun 30 2026

...BRIEF LANDSPOUTS WILL BE POSSIBLE ALONG A SURFACE BOUNDARY
ACROSS...NORTHEASTERN ARAPAHOE...SOUTHWESTERN WELD AND WESTERN ADAMS
COUNTIES UNTIL 515 PM MDT...

At 428 PM MDT, Doppler radar was tracking developing showers near
Denver International Airport, along a well defined north to south
surface boundary. Brief landspouts may develop along this boundary in
association with high-based showers or thunderstorms.

HAZARD...Landspouts and wind gusts up to 40 mph.

SOURCE...Radar indicated.

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

Locations impacted include...
  Aurora, northeastern Commerce City, Brighton, Denver International
  Airport, D.I.A Terminal and Concourses, Fort Lupton, Lochbuie,
  Platteville, Gilcrest, Barr Lake, Todd Creek, Watkins, Buckley SFB
  and Wattenburg.

LAT...LON 4000 10485 4020 10491 4029 10483 4030 10467
      4003 10467 3969 10454 3967 10476
TIME...MOT...LOC 2226Z 213DEG 25KT 3986 10472

LANDSPOUT...POSSIBLE
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

BRQ

<!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>