Alert archive / Texas / Flash Flood Warnings in 2009

Flash Flood Warning 94, NWS Fort Worth, TX

October 21, 2009Denton County, Tarrant County, Texas

NWS Fort Worth, TX issued this flash flood warning at Oct 21, 2009, 5:48 PM CDT for Denton County, Tarrant County, Texas. It was in force for 117 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Oct 21, 2009, 5:48 PM CDT (22:48 UTC)
Expired: Oct 21, 2009, 7:45 PM CDT
In force: 117 min
Issued by: NWS Fort Worth, TX
Area: Storm-based polygon
Flood severity: None

Counties Denton County, TX, Tarrant County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 47 km from the middle of the area, began a volume at 22:51 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

Fort Worth, TX (KFWD), launched 12:00Z, 10.8 hours before the alert went out and 19 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 185 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 471 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 286 m²/s²
0-3 km storm-relative helicity: 162 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 Fort Worth, TX wrote its last area forecast discussion before this flash flood warning went out at Oct 21, 3:02 PM CDT, 2 hours 46 minutes earlier.

Area forecast discussion, Oct 21, 3:02 PM CDT, 2 hours 46 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>

Hazardous weather outlook, Oct 21, 2:52 PM CDT, 2 hours 56 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
252 PM CDT WED OCT 21 2009

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-221200-
MONTAGUE-COOKE-GRAYSON-FANNIN-LAMAR-YOUNG-JACK-WISE-DENTON-COLLIN-
HUNT-DELTA-HOPKINS-STEPHENS-PALO PINTO-PARKER-TARRANT-DALLAS-
ROCKWALL-KAUFMAN-VAN ZANDT-RAINS-EASTLAND-ERATH-HOOD-SOMERVELL-
JOHNSON-ELLIS-HENDERSON-COMANCHE-MILLS-HAMILTON-BOSQUE-HILL-NAVARRO-
FREESTONE-ANDERSON-LAMPASAS-CORYELL-BELL-MCLENNAN-FALLS-LIMESTONE-
LEON-MILAM-ROBERTSON-
252 PM CDT WED OCT 21 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

A FLASH FLOOD WATCH IS IN EFFECT THROUGH 6 AM THURSDAY MORNING ALONG
AND EAST OF A LINE FROM BOWIE...TO WEATHERFORD...TO COPPERAS COVE.

AS AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT AFFECT THE
REGION TONIGHT...HEAVY RAINFALL ISL LIKELY...WITH TOTALS OF 1 TO 3
INCHES ARE EXPECTED...WITH ISOLATED TOTALS MAY EXCEED 4 INCHES.
SOILS ARE ALREADY SATURATED FROM PREVIOUS RAINFALL...SO ANY HEAVY
RAINFALL WILL LIKELY RUN OFF AND RESULT IN LOCALIZED FLASH FLOODING.

THE SEVERE THREAT APPEARS LOW...THOUGH A STRONG STORM OR TWO EMBEDDED
IN THE WIDESPREAD RAIN IS POSSIBLE LATE TONIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THUNDERSTORMS WILL TAPER OFF FROM WEST TO EAST ON THURSDAY AS A COLD
FRONT SWEEPS THROUGH NORTH TEXAS. SOME LOCALLY HEAVY RAINFALL MAY
STILL BE POSSIBLE ACROSS FAR EASTERN NORTH TEXAS THROUGH MID-MORNING.

LOW THUNDERSTORM CHANCES WILL RETURN SUNDAY NIGHT AND MONDAY...AS ANOTHER
COLD FRONT AND DISTURBANCE ALOFT AFFECT THE AREA.

.SPOTTER INFORMATION STATEMENT...

LIMITED SPOTTER ACTIVATION MAY BE REQUESTED OVERNIGHT FOR HEAVY
RAINFALL AND FLOOD REPORTS.

05/

The office that day

Everything else NWS Fort Worth, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 21, 8:50 AM CDT	Areal Flood Advisory	FWD	Denton, Hood, Johnson, Montague, Parker, Tarrant and 1 more	3 hr
Oct 21, 9:39 AM CDT	River Flood Warning	FWD	Delta, Hopkins	72 hr
Oct 21, 1:21 PM CDT	Areal Flood Advisory	FWD	Collin, Dallas, Denton, Ellis, Hill, Johnson and 1 more	3 hr
Oct 21, 4:26 PM CDT	Areal Flood Advisory	FWD	Collin, Dallas, Denton, Ellis, Johnson, Kaufman and 3 more	4 hr
Oct 21, 6:42 PM CDT	Flash Flood Warning	FWD	Denton	2 hr

Nearby

Flash Flood Warnings in Texas, 2009 Every flash flood warning in 2009

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.