Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 161

February 27, 201130 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 27, 2011, 10:54 PM CST for 30 counties in Texas. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Feb 27, 2011, 10:54 PM CST (04:54 UTC)
Expired
Feb 28, 2011, 12:30 AM CST
In force
96 min
Issued by
the Storm Prediction Center
All 30 counties

Anderson County, TX, Bell County, TX, Bosque County, TX, Cherokee County, TX, Collin County, TX, Coryell County, TX, Dallas County, TX, Ellis County, TX, Falls County, TX, Franklin County, TX, Freestone County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Lampasas County, TX, Leon County, TX, Limestone County, TX, McLennan County, TX, Milam County, TX, Navarro County, TX, Rains County, TX, Robertson County, TX, Rockwall County, TX, Smith County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 108 km from the middle of the area, began a volume at 04:55 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 00:00Z, 4.9 hours before the alert went out and 131 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 00:00Z on 2011-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 765 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2011-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 242 square meters per square second.1939587897117136Sfc1 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
765 J/kg
Mixed-layer CIN
-189 J/kg
Mixed-layer LCL
1244 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
242 m²/s²
0-3 km storm-relative helicity
264 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

374 
ACUS11 KWNS 280455
SWOMCD
SPC MCD 280454
TXZ000-280630-

MESOSCALE DISCUSSION 0161
NWS STORM PREDICTION CENTER NORMAN OK
1054 PM CST SUN FEB 27 2011

AREAS AFFECTED...HILL COUNTRY INTO NCNTRL/NERN TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 280454Z - 280630Z

SRN EDGE OF AT LEAST 30 METER H5 HEIGHT FALLS SKIRTING ACROSS CNTRL
TX LATE THIS EVENING HAS BEEN SUFFICIENT TO WEAKEN INHIBITION FOR
DEVELOPMENT OF TSTMS.  HOWEVER...PARCELS APPEAR TO REQUIRE THE
ENHANCED LIFT OF THE DRYLINE/FRONT AND BASES MAY BE SLIGHTLY
ELEVATED.  THIS WOULD CONTRIBUTE TO MAINLY A MRGLY SVR HAIL THREAT
IF THE STORMS REMAIN POST-FRONTAL.  HOWEVER...GIVEN THAT 70 KTS OF
WLY MID-LEVEL FLOW WAS TRANSLATING ACROSS TX...ANY STORM THAT CAN
MAINTAIN AN APPRECIABLE PCPN CORE ALONG/AHEAD OF THE FRONT COULD
QUICKLY ORGANIZE INTO A DMGG WIND THREAT AND WILL HAVE TO BE CLOSELY
MONITORED.  OTHERWISE...PRIMARY LARGE SCALE SUPPORT WILL PASS N OF
THE RED RIVER AND INTO AR OVERNIGHT WHERE THE MAJORITY OF SVR
WEATHER IS EXPECTED.

..RACY.. 02/28/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...SHV...HGX...FWD...EWX...

LAT...LON   31189827 33249677 33269516 32639484 31909506 31259588
            30749705 30899807 31189827

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 27, 8:07 PM CSTMesoscale DiscussionSPCBowie, Camp, Delta, Fannin, Franklin, Grayson and 5 more53 min
Feb 27, 10:04 PM CSTTornado WatchSPCBowie, Fannin, Grayson, Lamar, Red River6 hr

Nearby

Mesoscale Discussions in Texas, 2011Every mesoscale discussion in 2011

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.