Mesoscale Discussion 427

Issued

Apr 3, 2012, 3:32 AM CDT (08:32 UTC)

Expired

Apr 3, 2012, 5:00 AM CDT

In force

88 min

Issued by

the Storm Prediction Center

The Dyess AFB radar (KDYX), 83 km from the middle of the area, began a volume at 08:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

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547 
ACUS11 KWNS 030833
SWOMCD
SPC MCD 030832
OKZ000-TXZ000-031000-

MESOSCALE DISCUSSION 0427
NWS STORM PREDICTION CENTER NORMAN OK
0332 AM CDT TUE APR 03 2012

AREAS AFFECTED...PORTIONS W-CENTRAL/NW TX...SWRN/CENTRAL OK.

CONCERNING...SEVERE THUNDERSTORM WATCH 131...

VALID 030832Z - 031000Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 131
CONTINUES.

REMAINDER WW MAY BE ALLOWED TO EXPIRE AS SCHEDULED AT 9Z.  PORTIONS
NW...W-CENTRAL AND SW TX WILL CONTINUE TO BE MONITORED FOR
ADDITIONAL SVR DEVELOPMENT OF SUFFICIENT ORGANIZATION TO WARRANT
ANOTHER WW.

SFC MESOANALYSIS SHOWS PAC COLD FRONT FROM ERN TX PANHANDLE SEWD
THROUGH WAKE LOW INCREASINGLY DIFFUSE OUTFLOW BOUNDARY FROM EARLIER
MCS...ARCHING FROM E-CENTRAL KS W OF EMP...TO BETWEEN TUL-MKO...JUST
S OF ADM...AND S OF SPS OVER ARCHER COUNTY TX.  SRN PORTION OF THIS
BOUNDARY HAS BECOME QUASISTATIONARY.  ANY RELATIVELY DISCRETE
CONVECTION NW OF THIS BOUNDARY MAY POSE RISK FOR OCNL HAIL NEAR SVR
LEVELS...WITHIN N-S PLUME OF 500-1000 J/KG ELEVATED MUCAPE AND 30-40
KT EFFECTIVE SHEAR MAGNITUDES.  OVERALL SVR THREAT WITH THAT
ACTIVITY APPEARS MRGL HOWEVER.

STG-SVR GUSTS ALSO ARE POSSIBLE ON SRN FRINGES OF CONVECTION OVER NW
TX...ALONG FRONT AND S OF OUTFLOW BOUNDARY.  MODIFIED RAOBS AND FCST
SOUNDINGS SUGGEST PARCELS STILL MAY BE SFC-BASED AND BUOYANCY IS
MUCH LARGER.  MLCAPE 2000-3000 J/KG IS EVIDENT S OF OUTFLOW BOUNDARY
INTO EDWARDS PLATEAU REGION...WHERE DEW POINTS MID 60S TO NEAR 70 F
ARE OBSERVED...ALONG WITH 35-45 KT EFFECTIVE SHEAR.  ATTM IS REMAINS
UNCERTAIN HOW FAR CONVECTION WILL BACKBUILD SWD ALONG
FRONT...ESPECIALLY GIVEN EVIDENCE THAT APPRECIABLE UPPER SUPPORT
WILL REMAIN W OF THIS BOUNDARY.

FARTHER W...REFLECTIVITY ECHOES ARE GROWING IN COVERAGE WELL BEHIND
FRONT...BETWEEN BPG-LBB...AND NOW CONTAIN A FEW TSTMS. THIS
CORRESPONDS TO AREA OF PRONOUNCED IR CLOUD-TOP COOLING...BUT IS
LOCATED OVER VERY DRY NEAR-SFC AIR CHARACTERIZED BY DEW POINTS 7-20
DEG F.  THIS CONVECTION WILL REMAIN WELL BEHIND SFC-850 MB FRONT FOR
SEVERAL MORE HOURS AT LEAST.  MODIFIED FCST SOUNDINGS SUGGEST
CONVECTION IS ROOTED NEAR 600 MB...IN LAYER OF MIDLEVEL
COOLING/ASCENT/HUMIDIFICATION NOT WELL-HANDLED BY MOST PROGS.
RELATED BELT OF LARGE-SCALE ASCENT -- EVIDENT IN MOISTURE CHANNEL
IMAGERY IN GENTLE ARC FROM AMA TO BIG BEND REGION -- IS NOT LIKELY
TO MOVE MUCH FARTHER E GIVEN QUASISTATIONARY NATURE OF MID-UPPER
VORTEX OVER NRN NM.  ERN PERIPHERY OF THIS LIFT APPEARS TO BE W OF
SFC BOUNDARY...AND MAY REMAIN SO THROUGH PRE-DAWN HOURS.  DRY
MICROBURSTS FROM THIS ACTIVITY MAY PENETRATE THROUGH
SHALLOW/NEAR-SFC STABLE LAYER...GIVEN DEEP INVERTED-V PROFILES
APPARENT ON FCST SOUNDINGS BELOW CLOUD BASE.

..EDWARDS.. 04/03/2012

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

ATTN...WFO...FWD...OUN...SJT...LUB...MAF...

LAT...LON   31580141 32170171 32870175 33480160 33680113 33850023
            34179907 34959854 35699802 35459762 34189768 33199785
            32639810 30899934 32029927 32589961 32250052 31580141

Mesoscale Discussions in Texas, 2012Mesoscale Discussions in Oklahoma, 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.