Mesoscale Discussion 2240

Issued

Oct 8, 2011, 11:32 PM CDT (04:32 UTC)

Expired

Oct 9, 2011, 2:00 AM CDT

In force

2 hr

Issued by

the Storm Prediction Center

The Austin/San Antonio radar (KEWX), 124 km from the middle of the area, began a volume at 04:32 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.

706 
ACUS11 KWNS 090433
SWOMCD
SPC MCD 090432
TXZ000-090700-

MESOSCALE DISCUSSION 2240
NWS STORM PREDICTION CENTER NORMAN OK
1132 PM CDT SAT OCT 08 2011

AREAS AFFECTED...MUCH OF CENTRAL TX/HILL COUNTRY

CONCERNING...HEAVY RAINFALL

VALID 090432Z - 090700Z

HEAVY RAINFALL...WITH PEAK HOURLY RAINFALL RATES OF 1-2 IN/HR...WILL
CONTINUE TO OCCUR/SLOWLY DEVELOP GENERALLY EASTWARD OVERNIGHT ACROSS
A LARGE PART OF CENTRAL TX/HILL COUNTRY. ADDITIONALLY...A LOCALIZED
WIND DAMAGE THREAT CANNOT BE RULED OUT...BUT HEAVY RAINFALL WILL BE
THE PRIMARY CONCERN.

A CONVECTIVELY REINFORCED BOUNDARY/COLD POOL CONTINUES TO BE A FOCUS
FOR A NORTHEAST-SOUTHWEST ORIENTED CORRIDOR OF HEAVY RAINFALL ACROSS
A BROAD EXTENT OF CENTRAL TX...WITH THE BRUNT OF THE CONVECTIVE LINE
GENERALLY CENTERED AROUND 25-75 MILES WEST OF I-35 IN AREAS FROM THE
DFW METRO VICINITY TO SAN ANTONIO. COLD POOL/DIFFERENTIAL BOUNDARY
LIFT ASIDE...SUSTAINED FORCING FOR ASCENT...ATTRIBUTABLE TO
GRADUALLY STRENGTHENING WARM ADVECTION/UPPER JET ENTRANCE
REGION...WILL CONTINUE TO YIELD HEAVY RAINFALL WITHIN A VERY
MOIST/WEAKLY CAPPED AIRMASS. PW VALUES ARE ON THE ORDER OF 1.6-1.9
INCHES AS PER 00Z OBSERVED SOUNDINGS FROM CORPUS CHRISTI AND FORT
WORTH ALONG WITH MORE CONTEMPORARY GPS DERIVED DATA. WHILE
INDIVIDUAL CONVECTIVE ELEMENTS WILL CONTINUE TO STEADILY SPREAD
NORTH-NORTHEASTWARD...REGIONAL WIND PROFILERS/WSR-88D DERIVED WINDS
SUGGEST SOME BACKING OF MID-LEVEL WINDS OVER THE PAST FEW HOURS
WITHIN THIS MERIDIONAL LONGWAVE REGIME...SUCH THAT NET RESULT SHOULD
BE A CONTINUED ONLY SLOW EASTWARD NET MOTION OF THE
BROADER/COMPOSITE CONVECTIVE LINE. AS SUCH...EXPECTED HEAVY RAINFALL
TO PERSIST OVERNIGHT...WITH RAINFALL RATES OF 1-2 IN/HR POSSIBLE
WITH THE MORE INTENSE CONVECTIVE ELEMENTS. LASTLY...A LOCALIZED WIND
DAMAGE THREAT CANNOT BE RULED OUT OVERNIGHT GIVEN WATER
LOADING/SUFFICIENT LOW-MID LEVEL SHEAR AND STORM SCALE
PROCESSES/PERHAPS EVENTUAL MCV DEVELOPMENT. HOWEVER...ANY SUCH
THREAT IS EXPECTED TO BE LOCALIZED/MARGINAL IN NATURE.

..GUYER.. 10/09/2011

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

ATTN...WFO...FWD...CRP...EWX...SJT...

LAT...LON   28810050 30190044 33089782 32149711 30889796 28309937
            28810050

Mesoscale Discussions in Texas, 2011Every mesoscale discussion in 2011

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.