Current Mesoscale Discussions
SPC MD 859
MD 0859 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR NORTHEAST COLORADO...WESTERN NEBRASKA...NORTHWEST KANSAS
Mesoscale Discussion 0859
NWS Storm Prediction Center Norman OK
0212 PM CDT Sun May 18 2025
Areas affected...northeast Colorado...western Nebraska...northwest
Kansas
Concerning...Severe potential...Watch likely
Valid 181912Z - 182145Z
Probability of Watch Issuance...95 percent
SUMMARY...Supercells capable of very large hail, tornadoes, and
damaging wind are likely to develop after 21Z over northeast
Colorado, spreading into western Nebraska and northwest Kansas
through evening.
DISCUSSION...A surface low continues to deepen over eastern CO as
the shortwave trough moves across the area. Surface analysis shows a
prominent plume of low-level moisture extending out of western KS
and across northeast CO, where dewpoints are holding in the lower
50s F.
Full heating near and south of this moisture plume will erode the
minimal capping inversion by around 21Z, and rapid thunderstorm
development is expected. The combination of strong instability,
steep lapse rates, and veering winds with height will strongly favor
supercells capable of very large hail, and a few tornadoes. Activity
should easily remain severe into NE and KS this evening as the
southeasterly low-level jet persists, maintaining moisture advection
as well as shear and inflow.
..Jewell/Hart.. 05/18/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GID...LBF...DDC...GLD...PUB...BOU...CYS...
LAT...LON 39239981 38670057 38350123 38330167 38340215 39110277
39420328 39670364 39890412 40260434 40540451 40870437
41320401 41530379 41700344 41680291 41470190 41060094
40019974 39689971 39239981
MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
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SPC MD 858
MD 0858 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR NORTHWEST TO WEST-CENTRAL TEXAS
Mesoscale Discussion 0858
NWS Storm Prediction Center Norman OK
0158 PM CDT Sun May 18 2025
Areas affected...Northwest to west-central Texas
Concerning...Severe potential...Watch likely
Valid 181858Z - 182130Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorm development along the dryline is expected
roughly between 20-22 UTC across northwest to west-central Texas.
The convective environment will support supercells capable of large
hail, severe gusts, and a few tornadoes. Watch issuance is likely as
storms begin to develop.
DISCUSSION...Recent GOES visible imagery shows shallow, but slowly
deepening, cumulus along and just ahead of a sharpening dryline as
it continues to mix east and boundary-layer depth increases amid
filtered diurnal heating. Latest RAP/HRRR forecast soundings suggest
any lingering MLCIN will be minimized as surface temperatures warm
into the 92-95 F range over the next few hours within the warm
sector. Regional VWPs show flow within the lowest 2-3 km AGL
oriented roughly along the dryline, which should promote adequate
residence times for parcels to reach their LFCs and initiate deep
convection. Latest high-res solutions suggest this should occur
generally between 20-22 UTC. Thunderstorms will mature within a very
unstable air mass with MLCAPE values exceeding 4000 J/kg and
effective shear on the order of 40-50 knots. Limited directional
shear will initially promote splitting supercells with an attendant
very large hail threat (most probable max hail size may be 2-3
inches in diameter). Southeasterly low-level winds across northwest
TX may support adequate low-level veering for some tornado threat.
Further south (roughly south of I-20), 1.5 to 2.5 km LCL heights and
more backed low-level flow will modulate the initial tornado
potential. After 00 UTC a strengthening low-level jet will increase
low-level hodograph curvature and support an increasing tornado
threat with any remaining discrete right-moving supercells across
much of central/northern TX. Watch issuance will likely be needed as
thunderstorm initiation becomes more imminent.
..Moore/Hart.. 05/18/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FWD...OUN...SJT...LUB...
LAT...LON 30980132 31340102 32480013 32860000 33250004 33760012
34079996 34279965 34239910 34149872 33989849 33609835
33029840 32379865 31779894 31059956 30879979 30480066
30370100 30450133 30660147 30980132
MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN
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SPC Center Public Severe Weather Outlook (PWO)
Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0826 AM CDT SUN MAY 18 2025
...Severe thunderstorms expected over parts of the central High
Plains this afternoon...
* LOCATIONS...
South Central Kansas
Northwest Oklahoma
* HAZARDS...
Several tornadoes, a few intense
Scattered large hail, some baseball size
Isolated damaging winds
* SUMMARY...
Severe thunderstorms capable of all severe hazards are expected
later today across portions of the central and southern Plains.
Several strong to intense tornadoes are possible.
Preparedness actions...
Review your severe weather safety procedures for the possibility
of dangerous weather today. Stay tuned to NOAA Weather Radio,
weather.gov, or other media for watches and warnings. A tornado
watch means that conditions are favorable for tornadoes to form
during the next several hours. If a tornado warning is issued for
your area, move to a place of safety, ideally in a basement or
interior room on the lowest floor of a sturdy building.
&&
..Hart.. 05/18/2025
$$
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