Mesoscale Discussion 608

Issued

Apr 26, 2011, 8:53 PM CDT (01:53 UTC)

Expired

Apr 26, 2011, 10:30 PM CDT

In force

97 min

Issued by

the Storm Prediction Center

The Shreveport radar (KSHV), 149 km from the middle of the area, began a volume at 01:57 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 222Apr 26, 9:35 PM CDT
• Tornado Watch 223Apr 26, 9:45 PM CDT

227 
ACUS11 KWNS 270153
SWOMCD
SPC MCD 270153 
LAZ000-ARZ000-TXZ000-OKZ000-270330-

MESOSCALE DISCUSSION 0608
NWS STORM PREDICTION CENTER NORMAN OK
0853 PM CDT TUE APR 26 2011

AREAS AFFECTED...PORTIONS E TX...NRN LA...CENTRAL/SRN AR...EXTREME
SERN OK.

CONCERNING...TORNADO WATCH 215...220...

VALID 270153Z - 270330Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 215...220...CONTINUES.

WWS WILL NEED TO BE REPLACED BEFORE THEIR SCHEDULED 03Z EXPIRATION
TIME...BECAUSE THREAT FOR TORNADIC SUPERCELLS WILL CONTINUE ACROSS
MUCH OF THIS REGION WELL INTO OVERNIGHT HOURS E OF COLD
FRONT/DRYLINE.  FAVORABLE BUOYANCY AND STRENGTHENING OF BOTH
BOUNDARY-LAYER AND DEEP-TROPOSPHERIC SHEAR ARE EXPECTED.

PRIMARY CONVECTIVE DEVELOPMENT REGION REMAINS NEAR COLD
FRONT/DRYLINE TRIPLE POINT THAT IS PROPAGATING SWD FROM N-CENTRAL TX
INTO CENTRAL TX.  CONVECTION WILL CONTINUE TO MOVE EWD ACROSS
CORRIDOR FROM THERE OVER NE TX AND NRN LA...AND OTHER DEVELOPMENT
ALSO REMAINS POSSIBLE ALONG FRONTAL ZONE NEWD OVER NE TX AND SWRN
AR.  ENVIRONMENT IN CONVECTIVELY UNPERTURBED INFLOW AIR WILL BE
QUITE FAVORABLE...WITH SFC DEW POINTS 70S F HELPING TO MAINTAIN
SFC-BASED EFFECTIVE INFLOW PARCELS AND MLCAPE 1500-2500 J/KG THROUGH
AT LEAST 06Z.  LLJ IS EXPECTED TO INTENSIFY TO 60-70 KT ACROSS MUCH
OF THIS REGION AND VEER ONLY SLIGHTLY AS UPPER TROUGH OVER OK MOVES
EWD.  THIS WILL ENLARGE LOW-LEVEL HODOGRAPHS CONSIDERABLY WITH 0-1
KM SRH EXCEEDING 500 J/KG FROM E TX NWD AND EWD.  CAPPING INCREASES
WITH SWD EXTENT OVER WW 220...MAKING ADDITIONAL DEVELOPMENT MORE
CONDITIONAL...BUT SVR POTENTIAL WITH ANY SUSTAINED CONVECTION
REMAINS STG OVER THAT AREA.  CONVECTION THAT HAS BEEN STRUGGLING TO
INTENSIFY BETWEEN AUS-SAT IS MOVING ESEWD INTO ENVIRONMENT
CHARACTERIZED BY FAVORABLE MOISTURE AND INCREASING LOW-LEVEL
SHEAR...BUT ALSO STG CINH.  WHETHER OR NOT THIS ACTIVITY TAKES
ROOT...SLOW SWD BUILDING OF CENTRAL/E TX COMPLEX ALSO MAY AFFECT
SOME AREAS NOW COVERED BY WW 220.

..EDWARDS.. 04/27/2011

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

ATTN...WFO...JAN...LZK...LCH...SHV...TSA...HGX...FWD...EWX...

LAT...LON   29709576 29689712 30049765 31129775 31859716 33099635
            34189497 34569348 34529240 32679202 30949258 29709576

Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Louisiana, 2011Mesoscale Discussions in Arkansas, 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.