Mesoscale Discussion 770

Issued

May 28, 2016, 2:58 PM CDT (19:58 UTC)

Expired

May 28, 2016, 5:00 PM CDT

In force

2 hr

Issued by

the Storm Prediction Center

Chance of a watch

40%

The San Angelo radar (KSJT), 94 km from the middle of the area, began a volume at 20:02 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 226May 28, 4:00 PM CDT

714 
ACUS11 KWNS 281958
SWOMCD
SPC MCD 281958 
TXZ000-282200-

MESOSCALE DISCUSSION 0770
NWS STORM PREDICTION CENTER NORMAN OK
0258 PM CDT SAT MAY 28 2016

AREAS AFFECTED...PARTS OF CENTRAL/WEST-CENTRAL TEXAS AND THE BIG
BEND AREA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 281958Z - 282200Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED CONVECTIVE DEVELOPMENT IS POSSIBLE IN THE
DISCUSSION AREA OVER THE NEXT FEW HOURS...WITH SEVERE WIND AND HAIL
POSSIBLE BENEATH ANY SUSTAINED STORM.  A WW ISSUANCE IS POSSIBLE
WITH THIS ACTIVITY.

DISCUSSION...INCREASING AREAS OF TOWERING CUMULUS ARE OBSERVED VIA
VISIBLE SATELLITE IMAGERY ACROSS THE DISCUSSION AREA OVER THE PAST
30 MINUTES OR SO.  LARGER-SCALE FORCING FOR ASCENT AND SURFACE
CONVERGENCE ARE NEGLIGIBLE ACROSS THIS AREA...ALTHOUGH THE OBSERVED
TCU ARE LIKELY ASSOCIATED WITH BOUNDARY LAYER PROCESSES ASSOCIATED
WITH INSOLATION AND STRONG INSTABILITY /GREATER THAN 2000 J/KG
MUCAPE/ ACROSS THE REGION.  OBJECTIVE ANALYSES AND FORECAST
SOUNDINGS SUGGEST THAT ANY CONVECTIVE INHIBITION ACROSS THIS REGION
HAS WEAKENED CONSIDERABLY SINCE THIS MORNING DUE TO SURFACE HEATING.
 DESPITE THE WEAK FORCING FOR ASCENT...MODEL GUIDANCE AND
OBSERVATIONS SUGGEST THAT ISOLATED THUNDERSTORM DEVELOPMENT WILL
OCCUR ACROSS THIS REGION AFTER ABOUT 21Z.

DEEP SHEAR IN THE REGION FAVORS SOME VENTING OF UPDRAFTS ALOFT AS
STORMS MATURE...ESPECIALLY GIVEN 50-60 KNOT FLOW AT 9KM AGL. 
HOWEVER...LOW- AND MID-LEVEL WIND FIELDS ARE RELATIVELY WEAK.  A
SLOW/ERRATIC EASTWARD MOTION IS EXPECTED WITH THIS ACTIVITY...WITH
PRIMARILY OUTFLOW-DOMINATED /PULSE-TYPE/ STORMS FAVORED GIVEN THE
WEAK LOW-AND MID-LEVEL FIELDS.  TOWARD 00Z...LOW-LEVEL WINDS SHOULD
INCREASE ATTENDANT TO NOCTURNAL BOUNDARY LAYER PROCESSES...WHICH MAY
RESULT IN A HIGHER SUPERCELL THREAT WITH ANY ONGOING CONVECTION. 
HAIL /SOME SIGNIFICANT/ AND SEVERE WIND GUSTS ARE THE PRIMARY
THREATS WITH ANY ACTIVITY THIS EVENING...AND A WW ISSUANCE MAY BE
NEEDED IF CONVECTIVE COVERAGE IS SUFFICIENT.

..COOK/CORFIDI.. 05/28/2016

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

ATTN...WFO...FWD...EWX...SJT...MAF...

LAT...LON   29180000 29650079 30030144 30430172 31090173 31700176
            32110154 32130064 32049976 31719892 31129864 30339868
            29799880 29409911 29289937 29180000

Mesoscale Discussions in Texas, 2016Every mesoscale discussion in 2016

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.