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SPC MD 661

MD 0661 CONCERNING SEVERE THUNDERSTORM WATCH 184... FOR SOUTH TEXAS
        
MD 0661 Image

Mesoscale Discussion 0661
NWS Storm Prediction Center Norman OK
0834 PM CDT Mon May 17 2021

Areas affected...South Texas

Concerning...Severe Thunderstorm Watch 184...

Valid 180134Z - 180330Z

The severe weather threat for Severe Thunderstorm Watch 184
continues.

SUMMARY...The severe threat associated with a strong supercell
continues across south Texas, and additional development is possible
in the next 1-2 hours.

DISCUSSION...Regional radar and GOES IR trends over the past hour
continue to show a pair of robust supercells on either side of the
Rio Grande exhibiting strong rightward deviant motion as they move
to the south along the river. The environment in the vicinity of the
U.S. supercell remains supportive for organized convection with
nearly 4000 J/kg MLCAPE and nearly 50 knots of effective bulk shear.
An increase in MLCIN may hinder storm intensity to some degree over
the next hour, but the general expectation is for this storm to
persist into the late evening hours as it moves into southern
portions of WW 184 towards Laredo, TX. To the north, new convection
is developing along a confluence axis and may intensify over the
next one to two hours. There is some uncertainty regarding the
intensity and coverage of this new convection given increasing
inhibition and somewhat weak forcing for ascent, but the general
environment will remain supportive for a conditional severe threat
through 11 PM CDT.

..Moore.. 05/18/2021

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

ATTN...WFO...CRP...EWX...BRO...

LAT...LON   29010083 29200013 29129897 28809828 28339814 27809860
            27299909 27259957 27609998 28130046 28680086 29010083 

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SPC MD 659

MD 0659 CONCERNING SEVERE THUNDERSTORM WATCH 181... FOR FAR NORTHEAST NEW MEXICO...SOUTHEAST COLORADO...THE NORTHERN PANHANDLES...AND SOUTHWEST KANSAS
MD 0659 Image


Mesoscale Discussion 0659
NWS Storm Prediction Center Norman OK
0723 PM CDT Mon May 17 2021

Areas affected...Far northeast New Mexico...southeast Colorado...the
northern Panhandles...and southwest Kansas

Concerning...Severe Thunderstorm Watch 181...

Valid 180023Z - 180230Z

The severe weather threat for Severe Thunderstorm Watch 181
continues.

SUMMARY...The threat for severe wind and hail will continue for WW
181 for the next few hours. Storms will likely reach southwest
Kansas by 03 UTC, and trends will be monitored for the need for a
downstream watch.

DISCUSSION...Prior discrete to semi-discrete convection across
northeast NM and the northwestern TX Panhandle continues to grow
upscale with a cohesive outflow discernible in velocity data from
regional radars. This activity is expected to continue to propagate
to the north/northwest into southeast CO, the northern Panhandles,
and potentially into southwest KS by around 03 UTC. Additionally,
new convective development is noted ahead of this line, but it is
unclear if this convection will pose a robust severe threat before
merging with the approaching line. The environment ahead of this
evolving line remains supportive for organized convection in the
near term, though the onset of diurnal cooling may limit instability
and overall storm intensity to some degree. The greatest severe risk
will likely remain across the Panhandles region into the overnight
hours where more persistent discrete storm modes are expected as
well as a strengthening low-level jet that will help maintain a
robust hail/wind (and perhaps a brief tornado) threat. A downstream
watch into southwest Kansas is possible if the line can maintain
intensity despite a gradual decrease in instability and
boundary-layer decoupling.

To the northwest, convection along the CO front range continues
exhibit gradual consolidation with an outflow boundary slowly
propagating eastward. This activity will continue to pose an
isolated severe wind risk for the next 1-2 hours before
boundary-layer decoupling occurs.

..Moore.. 05/18/2021

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

ATTN...WFO...DDC...GLD...AMA...PUB...ABQ...

LAT...LON   36770491 37510460 38380364 38560264 38190154 37820086
            37060044 36180001 35500011 35260108 35180264 35360309
            35890335 36360415 36770491 

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