Mesoscale Discussion 66

Issued

Jan 25, 2012, 2:12 AM CST (08:12 UTC)

Expired

Jan 25, 2012, 4:15 AM CST

In force

2 hr

Issued by

the Storm Prediction Center

The Austin/San Antonio radar (KEWX), 74 km from the middle of the area, began a volume at 08:16 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.

• Tornado Watch 14Jan 25, 3:20 AM CST

507 
ACUS11 KWNS 250813
SWOMCD
SPC MCD 250812
TXZ000-251015-

MESOSCALE DISCUSSION 0066
NWS STORM PREDICTION CENTER NORMAN OK
0212 AM CST WED JAN 25 2012

AREAS AFFECTED...PORTIONS CENTRAL/S TX.

CONCERNING...TORNADO WATCH 13...

VALID 250812Z - 251015Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 13 CONTINUES.

WW REPLACEMENT/RECONFIGURATION MAY BE REQUIRED BEFORE SCHEDULED 11Z
EXPIRATION...IN ORDER TO ADJUST WW COVERAGE FLUIDLY TO EVOLUTION OF
SVR THREAT AND CONVECTIVE TRENDS OVER S TX.  UNTIL THEN...WW MAY BE
CLEARED IN RELATIVELY STABLE AIR MASS W OF PRIMARY CONVECTIVE
BAND...EVIDENT AT 745Z IN SLOWLY EWD-MOVING MCS FROM NWRN WEBB
COUNTY TO MCCULLOCH COUNTY.

SFC MESOANALYSIS SHOWS LOW OVER NRN PORTION OF QLCS..NEAR MASON
COUNTY AS OF 730Z.  WARM FRONT ARCHING NE OF LOW HAS REACHED BELL
COUNTY...THEN ESEWD ACROSS CLL-BPT AND JUST OFFSHORE LA COAST.
CENTRAL TX SEGMENT OF THIS FRONT SHOULD CONTINUE MOVING N 5-15 KT IN
ERRATIC FASHION PRIOR TO ARRIVAL OF SFC LOW...CAUSING WARM SECTOR TO
SPREAD OVER MORE TERRITORY PRESENTLY N AND NE OF WW.  INVERTED
TROUGH WAS DRAWN FROM NRN EXTENT OF WARM FRONT NNEWD ACROSS
KAUFMAN/LAMAR COUNTIES...AND SHOULD REMAIN QUASISTATIONARY UNTIL LOW
PASSES ITS LONGITUDE LATER THIS MORNING.  GREATEST POTENTIAL FOR
WARM-SECTOR INTRUSION SHOULD BE E OF THAT TROUGH...WHICH ALSO
CORRESPONDED WELL TO ERN PORTION OF ELEVATED CONVECTIVE BAND THAT IS
REINFORCING BOUNDARY-LAYER STATIC STABILITY TO ITS W.

MEANWHILE...BACK IN CURRENT WARM SECTOR...STRONGLY DIFLUENT FLOW
ALOFT IS EVIDENT WITH LITTLE OR NO MLCINH FOR PARCELS CONTAINING SFC
DEW POINTS MID-UPPER 60S F...SUPPORTING MLCAPE 1000-1500
J/KG...AMIDST 35-45 KT EFFECTIVE SHEAR MAGNITUDES.  LOW-LEVEL SRH
WILL CONTINUE TO BE MAXIMIZED IN T-BONE SHAPED SWATH CORRESPONDING
TO WARM FRONTAL ZONE...AND SWD BENEATH STRONGEST PART OF LLJ AS
MAPPED...WHERE HODOGRAPHS ARE MOST ENLARGED. QLCS BOUNDING WRN
PORTION OF EFFECTIVE WARM SECTOR MAY MERGE WITH MESSY/CLUSTERED
CONVECTIVE AREA TO ITS E OVER SAT-AUS CORRIDOR...THOUGH SOME
SHORT-FUSED CONVECTIVE-ALLOWING PROGS INDICATE LATTER ACTIVITY
BECOMING PRIMARY MCS WITH TIME.  IN EITHER EVENT...SFC-BASED SVR
THREAT SHOULD SPREAD N WITH WARM FRONT AND SLOWLY EWD FROM WW 13
DURING NEXT SEVERAL HOURS.

..EDWARDS.. 01/25/2012

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

ATTN...WFO...HGX...FWD...CRP...EWX...BRO...SJT...

LAT...LON   27960003 30399941 31479822 32039675 31889604 31499538
            30079522 28969620 27409806 27289948 27599947 27639970
            27789982 27789987 27949989 27960003

Mesoscale Discussions in Texas, 2012Every mesoscale discussion in 2012

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.