Mesoscale Discussion 252

Issued

Mar 8, 2013, 3:43 PM CST (21:43 UTC)

Expired

Mar 8, 2013, 6:15 PM CST

In force

3 hr

Issued by

the Storm Prediction Center

Chance of a watch

60%

The Amarillo radar (KAMA), 90 km from the middle of the area, began a volume at 21:40 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.

057 
ACUS11 KWNS 082143
SWOMCD
SPC MCD 082143 
OKZ000-TXZ000-KSZ000-090015-

MESOSCALE DISCUSSION 0252
NWS STORM PREDICTION CENTER NORMAN OK
0343 PM CST FRI MAR 08 2013

AREAS AFFECTED...WRN TX THROUGH THE CNTRL AND ERN TX AND OK
PANHANDLES AND EXTREME SWRN KS

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 082143Z - 090015Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...THUNDERSTORMS ARE EXPECTED TO DEVELOP EARLY THIS EVENING
ACROSS A PORTION OF WRN TX NWD INTO THE CNTRL TX PANHANDLE AND LATER
INTO PARTS OF THE OK PANHANDLE AND EXTREME SWRN KS. TIMING IS
SOMEWHAT UNCERTAIN...BUT INITIATION POTENTIAL IS EXPECTED TO
INCREASE SUBSTANTIALLY BETWEEN 23-01Z.

DISCUSSION...DRYLINE WAS LOCATED FROM THE CNTRL TX PANHANDLE NEAR
AMARILLO SWD THROUGH WRN TX. DOWNWARD MIXING OF STRONGER SWLY WINDS
ALOFT HAS RESULTED IN THE DRYLINE SURGING EWD THROUGH NRN PARTS OF
WRN TX AND THE TX PANHANDLE. HOWEVER...THIS BOUNDARY HAS RECENTLY
BECOME NEARLY STATIONARY...AND WILL LIKELY BEGIN TO RETREAT WWD AS
MIXING DIMINISHES WITH THE ONSET OF NOCTURNAL COOLING. CHARACTER OF
CLOUDS IN VISIBLE IMAGERY AND NAM PFCS SUGGEST THE BOUNDARY LAYER IS
STILL CAPPED EAST OF DRYLINE...WHERE MOIST AXIS WITH LOW-MID 50S
DEWPOINTS CONTINUE ADVECTING NWWD BENEATH AN EML. THE ATMOSPHERE
CONTINUES TO DESTABILIZE NWD WHERE AN AXIS OF 500-1000 J/KG MLCAPE
CURRENTLY EXISTS EAST OF THE CAP ROCK. 

HIGH BASED STORMS DEVELOPING WITHIN ZONE OF DEEPER ASCENT AHEAD OF A
PROGRESSIVE SHORTWAVE TROUGH WILL CONTINUE SPREADING EWD THROUGH NM
INTO THE EARLY EVENING. THIS ZONE OF ASCENT ALONG WITH A PACIFIC
FRONT WILL EVENTUALLY INTERCEPT THE RETREATING DRYLINE  AND MOIST
AXIS OVER WRN TX DURING THE EARLY EVENING. THESE PROCESSES WILL
CONTRIBUTE TO A WEAKENING CAP...AND THUNDERSTORMS WILL LIKELY
DEVELOP ALONG THE DRYLINE AND SUBSEQUENTLY SPREAD NEWD. SHEAR
PROFILES WILL INCREASE TO AOA 45 KT SUPPORTING THE POTENTIAL FOR
SUPERCELLS. MAIN THREATS WILL BE LARGE HAIL AND DAMAGING WIND GUSTS.
0-1 KM HODOGRAPHS WILL INCREASE IN SIZE THIS EVENING.
HOWEVER...TENDENCY FOR THE BOUNDARY LAYER TO STABILIZE AS THE LLJ
STRENGTHENS SHOULD KEEP TORNADO WINDOW RELATIVELY SMALL.

..DIAL/EDWARDS.. 03/08/2013

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

ATTN...WFO...OUN...DDC...LUB...AMA...MAF...

LAT...LON   32120171 32630245 34620209 36590206 37280164 36900021
            34839996 33150071 32120171

Mesoscale Discussions in Texas, 2013Mesoscale Discussions in Oklahoma, 2013Every mesoscale discussion in 2013

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.