Mesoscale Discussion 415

Issued

Apr 2, 2012, 3:00 PM CDT (20:00 UTC)

Expired

Apr 2, 2012, 5:00 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

The Altus AFB radar (KFDR), 156 km from the middle of the area, began a volume at 19:59 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.

• Severe Thunderstorm Watch 129Apr 2, 3:40 PM CDT

451 
ACUS11 KWNS 022000
SWOMCD
SPC MCD 022000 
OKZ000-KSZ000-TXZ000-022200-

MESOSCALE DISCUSSION 0415
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT MON APR 02 2012

AREAS AFFECTED...NWRN TX...ERN OK/TX PANHANDLES...SWRN KS...WRN OK

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 022000Z - 022200Z

A TORNADO WATCH WILL LIKELY BE NEEDED FOR PORTIONS OF NWRN TX...THE
ERN OK/TX PANHANDLES...SWRN KS AND WRN OK THIS AFTERNOON AND
EVENING.

MID-AFTERNOON MESOANALYSIS SHOWS A COLD FRONT WAS LOCATED FROM SWRN
KS INTO ERN NM...WHICH IS BEGINNING TO STALL IN RESPONSE TO PRESSURE
FALLS AHEAD OF A POTENT NEGATIVELY TILT MIDLEVEL SHORTWAVE TROUGH. A
DRYLINE ACCOMPANIED BY DEEPENING CUMULUS EXTENDED SWD FROM THE KS
PORTION OF THE COLD FRONT...WHILE A PACIFIC FRONT WAS BEGINNING TO
ENTER W TX. SURFACE TEMPERATURES ALONG THE DRYLINE HAVE WARMED INTO
THE MID 80S...AND DEWPOINTS E OF THE BOUNDARY RESIDE IN THE UPR 50S
TO MID 60S. THE WARM/MOIST AIRMASS LOCATED ACROSS THE WARM SECTOR
COMBINED WITH STEEP MIDLEVEL LAPSE RATES /IN EXCESS OF 8 C PER KM IN
THE 700-500 MB LAYER/ ARE CONTRIBUTING TO A VERY UNSTABLE
ENVIRONMENT...WITH MLCAPE VALUES NEAR 3000 J/KG. 

AS THE UPPER DISTURBANCE LIFTS NWD ACROSS THE SRN HIGH PLAINS THIS
AFTERNOON AND EVENING...SHORT-TERM MODEL GUIDANCE INDICATES SURFACE
CYCLOGENESIS WILL RAPIDLY TAKE PLACE OVER NERN NM AND THE TX
PANHANDLE. STRONG LOW-LEVEL SWLY WINDS OVER W TX...POSSIBLY
ACCOMPANYING AN EWD SURGE OF THE PACIFIC FRONT...WILL QUICKLY SPREAD
EWD TOWARD THE DRYLINE...RESULTING IN STRENGTHENING LOW-LEVEL
CONVERGENCE. AS THIS TAKES PLACE...SCATTERED THUNDERSTORM ARE
FORECAST TO DEVELOP FROM THE KS TRIPLE POINT SWD ALONG THE DRYLINE
BY 22-00Z. 

DURING THE EARLY STAGES OF THIS CONVECTIVE EPISODE
TEMPERATURE-DEWPOINT SPREADS WILL BE NEAR 20F OVER THE WARM
SECTOR...AND MIDLEVEL FLOW/DEEP LAYER SHEAR WILL BE MARGINAL FOR
SUPERCELLS...WHICH MAY NEGATIVELY INFLUENCE THE POTENTIAL FOR
TORNADOES DUE TO EXCESSIVE OUTFLOW. HOWEVER...IF STORMS CAN REMAIN
QUASI-DISCRETE INTO THE EVENING...THEN A COOLER/MORE HUMID BOUNDARY
LAYER COUPLED WITH BACKING/STRENGTHENING 0-1 KM FLOW MAY LEAD TO A
MORE SUBSTANTIAL THREAT OF TORNADOES. OTHERWISE...STORMS WILL POSE A
THREAT FOR VERY LARGE HAIL GIVEN THE PRESENCE OF LARGE BUOYANCY AND
VERY STEEP LAPSE RATES...IN ADDITION TO LOCALLY DAMAGING WIND GUSTS.

..GARNER.. 04/02/2012

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

ATTN...WFO...ICT...OUN...DDC...LUB...AMA...

LAT...LON   34970042 36130111 37120141 38140066 38659896 37999792
            35149798 33869844 33529891 33469963 33830014 34970042

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