Special Weather Statement, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
324 PM MST Fri Jul 30 2021

.SYNOPSIS...Abundant monsoonal moisture will persist over northern
Arizona through the weekend. The greatest thunderstorm coverage is
expected today, with storms capable of producing high rain rates
and flash flooding. Thunderstorm coverage decreases Saturday and
Sunday with even less activity to begin next week.

&&

.DISCUSSION...High pressure is centered over the central plains
today leaving Arizona in a deep southerly flow. A moist monsoon
air mass remains in place which will continue to fuel daytime
thunderstorms through the upcoming weekend.

Convective showers and storms today have been more widespread and
a bit more vigorous across Yavapai and Coconino counties where
better instability lies. This area is likely also being influenced
by a bit of upper level support from a shortwave across southern
Arizona. Shower and storm activity this evening will continue to
favor this area. Isolated rainfall rates of 1 inch per hour are
likely through this evening and may lead to areas of flash
flooding where storms train over the same areas. A Flash Flood
Watch remains in effect for Coconino County through midnight
tonight. In addition, a few stronger storms may produce brief
gusty winds and small hail. Thunderstorm updrafts today have been
very short lived and unable to sustain much hail production.
Storms are expected to decrease later this evening but the
aforementioned shortwave will move northward tonight and this will
keep a chance for showers overnight across much of northern
Arizona.

The overall synoptic scale pattern changes very little over the
weekend meaning we will continue to see scattered showers/storms
each afternoon. Coverage will decrease slightly each day, but
isolated areas of heavy rain and a few stronger storms will be
possible. Saturated soils across the area will lead to a flash
flood threat in any areas that do receive heavy rainfall.

Next week, troughing develops east of the Rockies while a ridge of
high pressure strengthens across the western U.S. This will leave
Arizona in a drying northerly flow pattern. Expect thunderstorm
chances to retreat eastward across the state through the week.
Consequently, the building high and more sunshine will also lead
to warmer daytime temperatures and our more susceptible low
elevations may be nearing Excessive Heat criteria again.

Projections for next weekend favor monsoon moisture increasing
and spreading north leading to increasing thunderstorm chances.

&&

.AVIATION...For the 00Z package...Scattered thunderstorms will
persist through 03Z this evening before decreasing. Most numerous
coverage will be west of KFLG. Periods of MVFR/IFR conditions and
gusty, erratic winds will occur in and around thunderstorms.
Storm coverage will decrease after 03Z, but the chance for a few
storms will continue overnight. Expect showers and storms to
increase again after 18Z Sat. Aviation discussion not updated for
TAF amendments.

&&

.FIRE WEATHER...Scattered thunderstorms will continue this evening,
most widespread in northwestern Arizona. Flash flooding and
lightning are the primary hazards. Lesser coverage is anticipated
for Saturday and Sunday. Light winds are forecast outside of
thunderstorm activity.

Monday through Wednesday...Expect a drying and warming trend next
week with less thunderstorm coverage each afternoon.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Flash Flood Watch until 11 PM MST
this evening FOR AZZ004>007-012-015.

&&

PUBLIC...MCT
AVIATION...MCT
FIRE WEATHER...MCT

For Northern Arizona weather information visit
weather.gov/flagstaff

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1236 PM MST FRI JUL 30 2021

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

0300 PM     FLOOD            1 ESE MOENKOPI          36.10N 111.20W
07/29/2021                   COCONINO           AZ   OTHER FEDERAL

            9.7 FOOT RISE ON THE MOENKOPI GAGE -
            STARTING AT 3 PM MST ON 7/29/21 AND PEAKING
            AT 445 AM MST ON 7/30/21.

&&

BEP

Special Weather Statement
National Weather Service Flagstaff AZ
301 PM MDT Fri Jul 30 2021

AZZ010-302130-
Chinle Valley-
301 PM MDT Fri Jul 30 2021

...SIGNIFICANT WEATHER ADVISORY FOR APACHE COUNTY UNTIL 330 PM MDT...

At 300 PM MDT, Doppler radar was tracking a strong thunderstorm 7
miles southwest of Round Rock, or 19 miles north of Chinle, moving
northwest at 15 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Round Rock, Many Farms Lake and Many Farms.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

LAT...LON 3640 10941 3632 10960 3645 10977 3658 10946
TIME...MOT...LOC 2100Z 153DEG 13KT 3643 10955

ET

<!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>