Alert archive / Florida / Flash Flood Warnings in 2020

Flash Flood Warning 11, NWS Jacksonville, FL

August 4, 2020Duval County, Florida

NWS Jacksonville, FL issued this flash flood warning at Aug 4, 2020, 8:40 PM EDT for Duval County, Florida. 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 4, 2020, 8:40 PM EDT (00:40 UTC)
Expired: Aug 4, 2020, 11:19 PM EDT
In force: 3 hr
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Flood severity: None

County Duval County, FL

The radar

The Jacksonville radar (KJAX), 17 km from the middle of the area, began a volume at 00:41 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.

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 Jacksonville, FL wrote its last area forecast discussion before this flash flood warning went out at Aug 4, 3:39 PM EDT, 5 hours 1 minute earlier.

Area forecast discussion, Aug 4, 3:39 PM EDT, 5 hours 1 minute before

Area Forecast Discussion
National Weather Service Jacksonville FL
339 PM EDT Tue Aug 4 2020

.NEAR TERM [Tonight and Wednesday]...Trailing trough from T.S.
Isaias extending into Ga will be a focus for scattered thunderstorms
to continue across se Ga through the the evening hours. Another
area for possible development will be near the ne Fl coast where
the east coast seabreeze is slowly moving inland. Warm and dry air
aloft will limit the severe potential with any isolated strong
storms resulting from boundary and cell mergers. Similar pattern
on Wednesday with a light sw flow favoring eastern zones for
afternoon/evening convection. Hot and humid conditions will
continue with low temperatures tonight mostly in the 75-80 degree
range. Heat indices will again reach near 105F Wednesday
afternoon.

.SHORT TERM [Wednesday night through Friday Night]...Troughing
will persist to the northwest with ridge to the southeast. A
southwest steering flow will decrease on Friday as the ridge
builds closer the area. Moisture will be at or above normal which
will mean scattered to numerous diurnal seabreeze storms.
Temperatures will be at or above average.

.LONG TERM [Saturday Through Tuesday]...Subtropical ridge will
remain just to the south through the period. Daily seabreezes
with ample moisture remaining over the area will result in
scattered to numerous thunderstorms each afternoon and evening.
Highest coverage of storms will be over inland areas as the
seabreezes move inland and merge over the interior. Steering winds
will be light and variable resulting in slow moving storms and
areas of locally heavy rainfall. The stronger storms will also
produce strong gusty winds and frequent ligthning strikes.

&&

.MARINE...Troughing will linger over the southeastern states
through Thursday along with prevailing south southwesterly winds
in place over our waters. The sea breeze will develop near the
coast each afternoon resulting in onshore winds over the near
shore waters. The Atlantic surface high pressure system will
build westward across the Florida peninsula late this week and
weekend with prevailing southerly winds. Scattered to numerous
thunderstorms will push into the coastal waters during the late
afternoon and evening hours through Thursday.

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  73  94  73  94  72 /  50  60  50  70  20
SSI  78  90  78  90  77 /  30  30  30  70  30
JAX  75  93  74  93  74 /  40  50  40  70  20
SGJ  75  90  74  90  74 /  30  30  30  70  20
GNV  74  93  73  91  73 /  10  30  30  70  20
OCF  74  91  73  91  73 /   0  40  30  70  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.

&&

In the hours before

Local storm report, Aug 4, 8:05 PM EDT, 35 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>

Local storm report, Aug 4, 8:07 PM EDT, 33 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>

Local storm report, Aug 4, 8:09 PM EDT, 31 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>

Special weather statement, Aug 4, 8:18 PM EDT, 22 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>

Local storm report, Aug 4, 8:33 PM EDT, 7 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>

Special weather statement, Aug 4, 8:33 PM EDT, 7 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 Jacksonville, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 4, 8:05 PM EDT	Areal Flood Warning	JAX	Duval	3 hr
Aug 4, 8:18 PM EDT	Special Weather Statement	JAX	Duval	42 min
Aug 4, 8:23 PM EDT	Severe Thunderstorm Warning	JAX	Duval, Nassau	38 min
Aug 4, 8:25 PM EDT	Special Marine Warning	JAX		65 min
Aug 5, 2:27 PM EDT	Special Weather Statement	JAX	Duval	33 min
Aug 5, 2:59 PM EDT	Special Weather Statement	JAX	Duval	31 min
Aug 5, 3:50 PM EDT	Special Weather Statement	JAX	Bradford	25 min
Aug 5, 4:06 PM EDT	Special Weather Statement	JAX	Flagler	24 min
Aug 5, 4:47 PM EDT	Special Weather Statement	JAX	Duval	43 min
Aug 5, 5:03 PM EDT	Special Weather Statement	JAX	Marion	27 min
Aug 5, 5:21 PM EDT	Special Weather Statement	JAX	Baker	24 min
Aug 5, 5:30 PM EDT	Special Weather Statement	JAX	Marion	30 min
Aug 5, 6:08 PM EDT	Special Weather Statement	JAX	Clay	37 min
Aug 5, 6:37 PM EDT	Special Weather Statement	JAX	Duval	38 min
Aug 5, 6:41 PM EDT	Severe Thunderstorm Warning	JAX	Clay, Duval, Saint Johns	34 min
Aug 5, 6:44 PM EDT	Special Weather Statement	JAX	Alachua	46 min
Aug 5, 7:33 PM EDT	Special Weather Statement	JAX	Alachua	42 min
Aug 4, 8:33 PM EDT	Special Weather Statement	JAX	Echols	27 min
Aug 5, 6:22 PM EDT	Special Weather Statement	JAX	Brantley	23 min

Nearby

Flash Flood Warnings in Florida, 2020 Every flash flood warning in 2020

Sources

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