Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 8, NWS Fort Worth, TX

February 28, 2021Grayson County, Texas

NWS Fort Worth, TX issued this severe thunderstorm warning at Feb 28, 2021, 9:51 AM CST for Grayson County, Texas. It was in force for 30 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Feb 28, 2021, 9:51 AM CST (15:51 UTC)
Expired
Feb 28, 2021, 10:21 AM CST
In force
30 min
Issued by
NWS Fort Worth, TX
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Grayson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 151 km from the middle of the area, began a volume at 15:52 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 was reported inside it

TimeReportWhereRemark
Feb 28, 10:00 AM CSTHAIL 1.52 Ne Pottsboro, TXSPOTTER MEASURED PING PONG BALL SIZE HAIL AT FM406 AND KATY LANE NORTHEAST OF POTTSBORO.
Feb 28, 10:03 AM CSTHAIL 12 Ese Pottsboro, TXTRAINED SPOTTER REPORTING COPIOUS AMOUNTS OF QUARTER SIZE HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 3.9 hours before the alert went out and 125 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, Fort Worth, TX at 12:00Z on 2021-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1316 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 12:00Z on 2021-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 165 square meters per square second.1939587897117Sfc1 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
1316 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
666 m above ground
0-6 km bulk shear
71 kt
0-1 km storm-relative helicity
165 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
1.2
Supercell composite
3.6

Open this sounding in Storm Lab

The text

As transmitted.

685 
WUUS54 KFWD 281551
SVRFWD
TXC181-281630-
/O.NEW.KFWD.SV.W.0008.210228T1551Z-210228T1630Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Fort Worth TX
951 AM CST Sun Feb 28 2021

The National Weather Service in Fort Worth has issued a

* Severe Thunderstorm Warning for...
  Northern Grayson County in north central Texas...

* Until 1030 AM CST.

* At 951 AM CST, a severe thunderstorm was located near Pottsboro, or
  10 miles west of Denison, moving northeast at 55 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is possible.

* Locations impacted include...
  Denison, Whitesboro, Pottsboro, Eisenhower State Park, southern
  Lake Texoma and Sadler.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection get inside a sturdy structure and stay away from
windows.

&&

LAT...LON 3389 9663 3389 9658 3385 9663 3384 9662
      3382 9658 3382 9653 3377 9650 3378 9644
      3356 9694 3382 9694 3385 9687 3385 9684
      3388 9682 3386 9678 3382 9676 3383 9672
      3384 9669 3391 9668 3392 9666
TIME...MOT...LOC 1551Z 240DEG 49KT 3377 9673 

HAIL...1.00IN
WIND...<50MPH
$$

Dunn
2 follow-up statements
855 
WWUS54 KFWD 281607
SVSFWD

Severe Weather Statement
National Weather Service Fort Worth TX
1007 AM CST Sun Feb 28 2021

TXC181-281630-
/O.CON.KFWD.SV.W.0008.000000T0000Z-210228T1630Z/
Grayson TX-
1007 AM CST Sun Feb 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 AM CST
FOR NORTHERN GRAYSON COUNTY...

At 1007 AM CST, a severe thunderstorm was located over Pottsboro, or
near Denison, moving northeast at 50 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is possible.

Locations impacted include...
Denison, Pottsboro, Eisenhower State Park and southern Lake Texoma. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection stay inside a sturdy structure and keep away from
windows.

&&

LAT...LON 3389 9663 3389 9658 3385 9663 3384 9662
      3382 9658 3382 9653 3377 9650 3378 9644
      3371 9670 3385 9687 3385 9684 3388 9682
      3386 9678 3382 9676 3383 9672 3384 9669
      3391 9668 3392 9666
TIME...MOT...LOC 1607Z 239DEG 44KT 3380 9665 

HAIL...1.00IN
WIND...<50MPH
 
$$

Dunn
967 
WWUS54 KFWD 281621
SVSFWD

Severe Weather Statement
National Weather Service Fort Worth TX
1021 AM CST Sun Feb 28 2021

TXC181-281629-
/O.CAN.KFWD.SV.W.0008.000000T0000Z-210228T1630Z/
Grayson TX-
1021 AM CST Sun Feb 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN GRAYSON COUNTY IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore the warning has been cancelled.

LAT...LON 3389 9663 3389 9658 3385 9663 3384 9662
      3382 9658 3382 9653 3377 9650 3378 9644
      3371 9670 3385 9687 3385 9684 3388 9682
      3386 9678 3382 9676 3383 9672 3384 9669
      3391 9668 3392 9666
TIME...MOT...LOC 1616Z 240DEG 49KT 3388 9648 

$$

Dunn

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 28, 9:11 AM CSTSpecial Weather StatementFWDCooke34 min
Feb 28, 9:28 AM CSTSpecial Weather StatementFWDGrayson47 min
Feb 28, 11:06 AM CSTSpecial Weather StatementFWDDenton24 min
Feb 28, 11:18 AM CSTSevere Thunderstorm WarningFWDCollin, Cooke, Denton, Grayson57 min
Feb 28, 4:34 PM CSTSpecial Weather StatementFWDHopkins26 min

Nearby

Severe Thunderstorm Warnings in Texas, 2021Every severe thunderstorm warning in 2021

Sources

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