Alert archive / Texas / Special Weather Statements in 2012

Special Weather Statement, NWS Fort Worth, TX

July 20, 2012Collin County, Rockwall County, Texas

NWS Fort Worth, TX issued this special weather statement at Jul 20, 2012, 3:46 PM CDT for Collin County, Rockwall County, Texas. It was in force for 29 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 20, 2012, 3:46 PM CDT (20:46 UTC)
Expired: Jul 20, 2012, 4:15 PM CDT
In force: 29 min
Issued by: NWS Fort Worth, TX

Counties Collin County, TX, Rockwall County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 96 km from the middle of the area, began a volume at 20:46 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, 8.8 hours before the alert went out and 81 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: 1010 J/kg
Mixed-layer CIN: -172 J/kg
Mixed-layer LCL: 1582 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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What forecasters said that day

The local office's own words before this special weather statement 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 special weather statement went out at Jul 20, 12:39 PM CDT, 3 hours 7 minutes earlier.

Area forecast discussion, Jul 20, 12:39 PM CDT, 3 hours 7 minutes before

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  <meta name="viewport" content="width=device-width, initial-scale=1">
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  <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.
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        Please try again in a few minutes.
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Hazardous weather outlook, Jul 20, 3:32 PM CDT, 14 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
332 PM CDT FRI JUL 20 2012

TXZ091>095-100>107-115>123-129>135-141>148-156>162-174-175-211145-
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-
332 PM CDT FRI JUL 20 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH TEXAS.

.DAY ONE...TONIGHT.

ISOLATED THUNDERSTORMS ARE POSSIBLE NORTH OF A GRAHAM TO ENNIS
TO CANTON LINE THIS AFTERNOON. IF A STRONG STORM WERE TO
DEVELOP...IT COULD PRODUCE DAMAGING DOWNBURST WINDS.

A HEAT ADVISORY IS IN EFFECT FOR TARRANT...COLLIN...DALLAS AND
DENTON COUNTY.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

THE HEAT ADVISORY FOR TARRANT...COLLIN...DALLAS AND DENTON COUNTY
WILL CONTINUE THROUGH 8 PM SATURDAY.

.SPOTTER INFORMATION STATEMENT...
LIMITED SPOTTER ACTIVATION MAY BE REQUESTED NORTH OF A GRAHAM TO
ENNIS TO CANTON LINE THIS AFTERNOON.

In the hours before

Special weather statement, Jul 20, 3:46 PM CDT, 0 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
346 PM CDT FRI JUL 20 2012

TXZ104-105-119-120-202115-
DALLAS TX-HUNT TX-ROCKWALL TX-COLLIN TX-
346 PM CDT FRI JUL 20 2012

...SIGNIFICANT WEATHER ADVISORY FOR...
  COLLIN COUNTY
  NORTHEASTERN DALLAS COUNTY
  SOUTHWESTERN HUNT COUNTY
  ROCKWALL COUNTY

AT 346 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
STRONG THUNDERSTORM 7 MILES SOUTHEAST OF MCKINNEY...MOVING SOUTH AT 5
MPH.

CITIES IN THE PATH OF THIS STORM INCLUDE ALLEN...ANNA...CADDO
MILLS...FAIRVIEW...FARMERSVILLE...FATE...FRISCO...GARLAND...
GREENVILLE...HEATH...LOWRY CROSSING...LUCAS...MCKINNEY...MURPHY...
PARKER...PLANO...PRINCETON...PROSPER...RICHARDSON...ROCKWALL...
ROWLETT...ROYSE CITY...SACHSE AND WYLIE.

VERY HEAVY RAIN AND WIND GUSTS TO 50 MPH ARE LIKELY WITH THIS STORM.

LAT...LON 3333 9635 3311 9608 3284 9620 3284 9630
      3281 9630 3284 9669 3301 9685 3319 9684
      3339 9671
TIME...MOT...LOC 2046Z 349DEG 6KT 3314 9654

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 2:57 PM CDT	Heat Advisory	FWD	Collin, Cooke, Dallas, Delta, Denton, Fannin and 16 more	53 hr
Jul 20, 4:02 PM CDT	Special Weather Statement	FWD	Denton, Jack, Wise	28 min
Jul 20, 4:20 PM CDT	Special Weather Statement	FWD	Collin	25 min
Jul 20, 4:36 PM CDT	Special Weather Statement	FWD	Denton, Jack, Wise	24 min
Jul 20, 4:46 PM CDT	Special Weather Statement	FWD	Collin, Dallas, Rockwall	29 min
Jul 20, 4:56 PM CDT	Special Weather Statement	FWD	Jack, Young	34 min
Jul 20, 5:08 PM CDT	Special Weather Statement	FWD	Kaufman	37 min
Jul 20, 5:34 PM CDT	Special Weather Statement	FWD	Palo Pinto, Young	26 min
Jul 20, 5:37 PM CDT	Special Weather Statement	FWD	Dallas, Tarrant	23 min
Jul 20, 5:42 PM CDT	Special Weather Statement	FWD	Parker	33 min
Jul 20, 5:50 PM CDT	Severe Thunderstorm Warning	FWD	Dallas, Tarrant	25 min
Jul 20, 6:05 PM CDT	Special Weather Statement	FWD	Dallas, Tarrant	25 min
Jul 20, 6:14 PM CDT	Special Weather Statement	FWD	Johnson	31 min
Jul 20, 6:17 PM CDT	Special Weather Statement	FWD	Parker	28 min
Jul 20, 6:25 PM CDT	Severe Thunderstorm Warning	FWD	Dallas	24 min
Jul 20, 6:38 PM CDT	Special Weather Statement	FWD	Dallas, Johnson, Tarrant	37 min

Nearby

Special Weather Statements in Texas, 2012 Every special weather statement in 2012

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.