Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 2439

October 9, 2003Chambers County, Galveston County, Jefferson County, Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 9, 2003, 5:38 PM CDT for Chambers County, Galveston County, Jefferson County, Texas. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Oct 9, 2003, 5:38 PM CDT (22:38 UTC)
Expired
Oct 9, 2003, 7:15 PM CDT
In force
97 min
Issued by
the Storm Prediction Center

Counties Chambers County, TX, Galveston County, TX, Jefferson County, TX

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 10.6 hours before the alert went out and 140 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, Lake Charles Mun, LA at 12:00Z on 2003-10-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 49 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, Lake Charles Mun, LA at 12:00Z on 2003-10-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.193958Sfc1 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
49 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
805 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
122 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

081 
ACUS11 KWNS 092238
SWOMCD
SPC MCD 092238 
TXZ000-100015-

MESOSCALE DISCUSSION 2439
NWS STORM PREDICTION CENTER NORMAN OK
0538 PM CDT THU OCT 09 2003

AREAS AFFECTED...SE TX

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 092238Z - 100015Z

A FEW MINI-SUPERCELLS HAVE DEVELOPED AROUND THE HOUSTON AREA AND
ADDITIONAL ROTATING STORMS CAN BE EXPECTED TO DEVELOP OVER THE NEXT
FEW HOURS. THESE STORMS WILL CONTAIN AN ISOLATED TORNADO THREAT OVER
THE NEXT FEW HOURS...HOWEVER THE THREAT SHOULD REMAIN TOO MARGINAL
FOR A WW ATTM.

WV IMAGERY SHOWS A SHORTWAVE TROUGH MOVING EWD THROUGH SE TX. THE
ASCENT ASSOCIATED WITH THIS FEATURE HAS CAUSED A LARGE AREA OF HEAVY
RAIN WITH EMBEDDED THUNDERSTORMS. OBJECTIVE ANALYSIS SHOWS MODERATE
INSTABILITY FROM HOUSTON SWWD WITH 35 KT OF DEEP LAYER SHEAR. THIS
COMBINED WITH A TROPICAL MOISTURE PROFILE WILL FAVOR ISOLATED MINI
SUPERCELLS. FORECAST SOUNDINGS FOR THE HOUSTON AREA SHOW 0-1 KM
SHEAR AROUND 20 KT COMBINED WITH FAVORABLE DIRECTIONAL SHEAR
PROFILES FOR ISOLATED TORNADOES AT LEAST THROUGH 01Z. HOWEVER...THE
THREAT SHOULD BE MARGINAL AND SHOULD DIMINISH THIS EVENING AS THE
LOW-LEVEL JET WEAKENS AND SHIFTS NEWD ACROSS THE LOWER MS VALLEY.

..BROYLES.. 10/09/2003

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

ATTN...WFO...LCH...HGX...

29009500 30009500 30009400 29009300 29009400 29009500

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 9, 12:19 PM CDTMesoscale DiscussionSPCChambers, Galveston, Jefferson116 min

Nearby

Mesoscale Discussions in Texas, 2003Every mesoscale discussion in 2003

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.