Mesoscale Discussion 939

Issued

May 27, 2004, 10:29 AM CDT (15:29 UTC)

Expired

May 27, 2004, 12:30 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

The Lubbock radar (KLBB), 104 km from the middle of the area, began a volume at 15:29 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.

190 
ACUS11 KWNS 271529
SWOMCD
SPC MCD 271529 
TXZ000-OKZ000-NMZ000-271730-

MESOSCALE DISCUSSION 0939
NWS STORM PREDICTION CENTER NORMAN OK
1029 AM CDT THU MAY 27 2004

AREAS AFFECTED...WRN/CNTRL TX INTO SW OK

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 271529Z - 271730Z

CONVECTIVE TRENDS ARE BEING MONITORED FOR POSSIBILITY OF INCREASING
SEVERE THREAT. IMMINENT WW IS NOT ANTICIPATED...BUT COULD BECOME
NECESSARY THIS AFTERNOON.

PLUME OF MID/HIGH-LEVEL MOISTURE FROM THE SUBTROPICAL PACIFIC HAS
ADVECTED ACROSS THE MEXICAN PLATEAU INTO WEST TEXAS AND OKLAHOMA...
AHEAD OF SOUTHERN BRANCH TROUGH ACCELERATING EASTWARD OUT OF THE
SOUTHERN PLATEAU.  MOISTENING IS OCCURRING AND CONTRIBUTING TO
DESTABILIZATION ABOVE CAPPING INVERSION AND ELEVATED MIXED LAYER
...WHICH HAS SPREAD EASTWARD OFF THE HIGHER TERRAIN INTO THE PLAINS.


THIS DESTABILIZATION IS SUPPORTING ONGOING INCREASE IN CONVECTIVE
DEVELOPMENT IN ZONE OF ENHANCED MID-LEVEL ISENTROPIC ASCENT...EAST
OF DRYLINE ACROSS WEST CENTRAL TEXAS.  NEWER CONVECTIVE DEVELOPMENT
IS ALSO OCCURRING WEST OF DRY LINE...IN BAND OF STRONGER MID/UPPER
FORCING ASSOCIATED DIFFERENTIAL POSITIVE VORTICITY ADVECTION...
ALREADY SPREADING INTO THE NEW MEXICO/TEXAS BORDER AREA.

MODELS FORECAST SOUNDINGS SUGGEST CAPE FOR PARCELS IN ELEVATED MOIST
LAYER IS ONLY ON THE ORDER OF 500 TO 1000 J/KG... WHICH APPEARS
LIKELY TO MINIMIZE HAIL THREAT IN THE SHORT TERM.  HOWEVER...AS
BOUNDARY LAYER CONTINUES TO HEAT UP WEST OF EASTWARD SURGING DRY
LINE...THUNDERSTORM ACTIVITY IS EXPECTED TO BECOME ROOTED IN DEEP
MIXED BOUNDARY LAYER BY EARLY TO MID AFTERNOON.  AS THIS
OCCURS...EVAPORATIVE COOLING BELOW CLOUD BASES WILL ENHANCE
POTENTIAL FOR DAMAGING WIND GUSTS AS ACTIVITY INCREASES NEAR/NORTH
OF MIDLAND THROUGH THE CHILDRESS/ALTUS AREAS.

..KERR.. 05/27/2004

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

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

32770327 34340253 35160065 34899902 33559826 32669846
31269986 31730142 31060323

Mesoscale Discussions in Texas, 2004Mesoscale Discussions in Oklahoma, 2004Every mesoscale discussion in 2004

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.