A Mesodiscussion is issued by the National Weather Service's Storm Prediction Center when there is a chance of a significant weather event impacting an area. These are routinely issued before weather watches or as updated to weather watches.

SPC MD 570

MD 0570 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR PORTIONS OF CENTRAL/NORTH TX
MD 0570 Image

Mesoscale Discussion 0570
NWS Storm Prediction Center Norman OK
0141 PM CDT Sun May 09 2021

Areas affected...Portions of central/north TX

Concerning...Severe potential...Severe Thunderstorm Watch likely 

Valid 091841Z - 092015Z

Probability of Watch Issuance...80 percent

SUMMARY...The severe thunderstorm threat will increase with time
this afternoon, with a few supercells possible. Very large hail will
be the primary threat, with locally severe wind gusts also possible.
Watch issuance is likely by 20Z.

DISCUSSION...At 1830Z, a cold front is moving southeastward across
parts of central/north TX. A plume of elevated convection is noted
just east of the front, with gradually deepening cumulus noted along
the front itself. As the cap continues to erode this afternoon,
scattered surface-based storms are expected to develop along the
front, and may also possibly evolve from the plume of elevated
convection to the east. Steep midlevel lapse rates are supporting
moderate-to-strong buoyancy across the region, with MLCAPE of
2000-3000 J/kg along/east of the front per recent objective
mesoanalyses. While low-level flow is expected to gradually weaken
across the area with time, midlevel flow will remain relatively
strong, supporting effective shear of 40-50 kt. 

As surface-based storms mature this afternoon, a few supercells are
likely to develop, with a threat of very large hail. Locally severe
wind gusts will also be possible, especially with any upscale
growing clusters that may evolve with time. Severe thunderstorm
watch issuance is likely by 20Z.

..Dean/Thompson.. 05/09/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...HGX...FWD...EWX...SJT...

LAT...LON   30939933 31599815 32449667 32869598 32759576 32129561
            31609547 30629519 30069751 29979861 30339929 30559936
            30939933 

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SPC MD 569

MD 0569 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST NEW MEXICO...FAR SOUTHEAST COLORADO...AND THE FAR WESTERN TEXAS PANHANDLE
MD 0569 Image

Mesoscale Discussion 0569
NWS Storm Prediction Center Norman OK
0131 PM CDT Sun May 09 2021

Areas affected...Northeast New Mexico...far southeast Colorado...and
the far western Texas Panhandle

Concerning...Severe potential...Watch unlikely 

Valid 091831Z - 092100Z

Probability of Watch Issuance...20 percent

SUMMARY...Thunderstorms developing across northeast New Mexico and
far southeast Colorado over the next few hours will pose a threat
for damaging winds and perhaps isolated hail. This threat will
remain isolated, and a watch is not expected.

DISCUSSION...A deepening cluster of cumulus within a post
cold-frontal upslope flow regime across north/northeastern NM is
noted in recent GOES imagery. A few lightning strikes have been
noted in the past hour with transient convective cells, hinting that
more robust convection is possible in the next 1-2 hours. Across the
high Plains to the east, temperatures are gradually warming into the
low 60s amid partly cloudy skies. Cool temperatures aloft atop the
warming boundary-layer are steepening low-level lapse rates to 7-9
C/km, and this trend should continue with eastward extent through
the late afternoon. Although instability will remain somewhat
limited due to minimal low-level moisture (only around 500 J/kg
MLCAPE is expected), 30-45 knot effective bulk shear magnitudes may
support some storm organization and an isolated hail threat adjacent
to the higher terrain. Given the well-mixed boundary layer, strong
downburst winds appear to be the more likely hazard. In general, the
localized forcing for ascent and limited instability will likely
result in only a few strong to severe storms that may propagate as
far east as the NM/TX border by early evening. The overall severe
threat is expected to remain isolated, precluding the need for a
watch.

..Moore/Thompson.. 05/09/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LUB...AMA...PUB...ABQ...

LAT...LON   34710551 35170586 35680611 36390582 36940551 37290510
            37470460 37450410 37130357 36620325 35960290 34930287
            34320307 34300453 34710551 

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