Alert archive / Arizona / Flash Flood Warnings in 2022

Flash Flood Warning 182, NWS Flagstaff, AZ

August 12, 2022Yavapai County, Arizona

NWS Flagstaff, AZ issued this flash flood warning at Aug 12, 2022, 12:42 PM MST for Yavapai County, Arizona. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 12, 2022, 12:42 PM MST (19:42 UTC)
Expired
Aug 12, 2022, 3:45 PM MST
In force
3 hr
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 124 km from the middle of the area, began a volume at 19:45 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 7.7 hours before the alert went out and 98 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Flgstf/Belemont, AZ at 12:00Z on 2022-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 9 joules per kilogram.LCLLFCEL10008507005003002001001 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2022-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
9 J/kg
Mixed-layer CIN
-392 J/kg
Mixed-layer LCL
2754 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
-19 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Flagstaff, AZ wrote its last area forecast discussion before this flash flood warning went out at Aug 12, 9:25 AM MST, 3 hours 17 minutes earlier.

Area forecast discussion, Aug 12, 9:25 AM MST, 3 hours 17 minutes before
Area Forecast Discussion
National Weather Service Flagstaff AZ
925 AM MST Fri Aug 12 2022

.SYNOPSIS...Daily showers and thunderstorms will continue across
much of northern Arizona through the weekend. Scattered to
widespread thunderstorms are likely each afternoon, with flash
flooding being the main threat.

&&

.UPDATE...Storms are already firing up over the San Francisco
Peaks this morning, leading to heightened flash flooding fears
over the area. Expect storms to significantly increase in coverage
today, first over the high country, before spilling over into the
low country. Avoid vulnerable areas, like normally-dry washes,
slot canyons, drainages, streams, etc. Heavy rainfall may turn
spots like these into raging torrents.

&&

.PREV DISCUSSION /217 AM MST/...The active monsoon pattern is
expected to continue for the days to come. As a result, another
Flash Flood Watch is in place for 11 AM MST to 11 PM MST Friday.
This watch includes most of our CWA with the exception of the
northeastern portion of our state. This was largely decided based
on model guidance and the Weather Prediction Center Excessive
Rainfall Outlook for Day 1, where there was a slight risk for
northern Arizona. There could be a need for additional Flash Flood
Watches in our CWA past today, but there are none in place at
this time.

Over the weekend...Thunderstorm activity will continue to
dominate during the afternoon hours, primarily thanks to daytime
heating. The late evening/overnight hours will likely remain the
less active portion of each day for the near future. Expect
another few days of above average PW values and high surface
dewpoints as moisture continues to funnel in from the south. At
this time, there are no major indications by models of our monsoon
activity declining for this forecast period.

Beginning of next week...The high pressure system currently
centered over the Oklahoma Panhandle is looking to shift westward
toward the Pacific Northwest. This transition will be caused by a
deepening trough on the east coast. Even with the change in our
synoptic pattern, there will still be a southerly flow aloft,
continuing to move moisture into Arizona.

&&

AVIATION...For the 18Z TAF package..Expect widespread showers and
thunderstorms into the early evening hours becoming isolated by
midnight. VFR conditions and light surface winds away from storms.
Aviation discussion not updated for TAF amendments.

&&

FIRE WEATHER...The active monsoon pattern continues today and
Saturday with widespread shower and thunderstorm coverage. The main
threats include flash flooding and gusty, erratic outflow winds.
Light winds expected outside of storms with little change in
temperatures.

Sunday through Tuesday...Daily shower and thunderstorm activity will
continue. Look for light winds with little change in temperatures.

&&

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
Flood Watch through this evening for AZZ004>008-012>018-037-038-
104>108-112>118-137-138.

&&

PUBLIC...BJ
AVIATION...McCollum
FIRE WEATHER...McCollum

For Northern Arizona weather information visit
weather.gov/flagstaff

In the hours before

Local storm report, Aug 12, 10:28 AM MST, 2 hours 14 minutes before
<!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>

The office that day

Everything else NWS Flagstaff, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 11, 5:20 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Aug 11, 5:38 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 11, 6:22 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo3 hr
Aug 11, 6:39 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Navajo6 hr
Aug 11, 6:50 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Navajo3 hr
Aug 12, 1:30 AM MSTFlood WatchFGZApache, Coconino, Gila, Navajo, Yavapai22 hr
Aug 12, 10:53 AM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 12, 10:59 AM MSTAreal Flood AdvisoryFGZCoconino3 hr
Aug 12, 11:24 AM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 12, 11:46 AM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 12, 11:54 AM MSTSevere Thunderstorm WarningFGZYavapai36 min
Aug 12, 12:02 PM MSTSevere Thunderstorm WarningFGZCoconino24 min
Aug 12, 12:36 PM MSTSevere Thunderstorm WarningFGZCoconino39 min
Aug 12, 1:00 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 12, 1:10 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 12, 1:29 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 12, 1:47 PM MSTFlood WatchFGZApache, Coconino, Gila, Navajo, Yavapai33 hr
Aug 12, 1:58 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 12, 2:11 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Aug 12, 4:13 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Aug 12, 4:36 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino, Navajo3 hr

Nearby

Flash Flood Warnings in Arizona, 2022Every flash flood warning in 2022

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.