RSS Mesoscale Discussions from Storm Prediction Center

SPC MD 1726

MD 1726 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHWEST TX
        
MD 1726 Image

Mesoscale Discussion 1726
NWS Storm Prediction Center Norman OK
0541 PM CDT Sat Oct 21 2017

Areas affected...Northwest TX

Concerning...Severe potential...Watch unlikely 

Valid 212241Z - 220015Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated severe wind gusts and marginally severe hail will
be possible with high-based storms west of the dryline. A severe
thunderstorms watch issuance is unlikely in this corridor, but a
watch issuance is much more probable farther east later this
evening.

DISCUSSION...High-based convection has developed between the
west/east-oriented cold front and southwest/northeast-oriented
dryline across the South Plains and Low Rolling Plains of northwest
TX. A 54 kt gust was recorded by the Sundown TX mesonet site at
2210Z. Very large surface temperature/dew point spreads will support
a continued risk for isolated severe wind gusts. While MLCAPE is
likely meager, strong speed shear within the cloud-bearing layer
should foster small hail, possibly approaching quarter size. As the
cold front further overtakes the dryline, increasing linear
convective coverage is anticipated and this should necessitate watch
issuance east of the dryline later this evening.

..Grams/Guyer.. 10/21/2017

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

ATTN...WFO...OUN...SJT...LUB...MAF...

LAT...LON   33960202 34160059 34440002 34359952 33309971 32590042
            32510079 32440170 32620237 33100266 33770239 33960202 

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SPC MD 1725

MD 1725 CONCERNING SEVERE THUNDERSTORM WATCH 502... FOR EASTERN KANSAS...WESTERN MISSOURI...AND FAR SOUTHERN IOWA
MD 1725 Image


Mesoscale Discussion 1725
NWS Storm Prediction Center Norman OK
0538 PM CDT Sat Oct 21 2017

Areas affected...Eastern Kansas...western Missouri...and far
southern Iowa

Concerning...Severe Thunderstorm Watch 502...

Valid 212238Z - 212345Z

The severe weather threat for Severe Thunderstorm Watch 502
continues.

SUMMARY...The risk of damaging wind gusts and isolated hail
continues along and ahead of a squall line in western portions of WW
502.

DISCUSSION...Storms have mostly congealed into linear segments along
an outflow that extends from near STJ to TOP to just southeast of
ICT.  Several of these storms are mostly behind this outflow and
slightly elevated atop a stable boundary layer - especially across
south-central Kansas.  Hail will be the primary threat with this
activity, while damaging wind gusts will be the primary threat with
convection along and ahead of the boundary - particularly with
storms near and east of the Topeka area that have exhibited bowing
segments.  An additional risk for surface based activity will occur
with pre-frontal convection migrating northeastward from
north-central Oklahoma.

West of this line, the severe threat is diminishing as thermodynamic
profiles stabilize behind the cold front.  The severe thunderstorm
watch may be cancelled early for areas behind the front.  See
attendant Watch Status messages for further guidance.

..Cook.. 10/21/2017

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

ATTN...WFO...SGF...DMX...EAX...TSA...OAX...TOP...ICT...OUN...

LAT...LON   40729504 40969470 41019363 40739272 40309272 39089353
            37719455 36889537 36909646 36949752 37009813 37559787
            38499716 38979670 40729504 

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SPC MD 1724

MD 1724 CONCERNING TORNADO WATCH 503... FOR WESTERN/CENTRAL OK AND NORTH TX
        
MD 1724 Image

Mesoscale Discussion 1724
NWS Storm Prediction Center Norman OK
0505 PM CDT Sat Oct 21 2017

Areas affected...Western/central OK and North TX

Concerning...Tornado Watch 503...

Valid 212205Z - 212330Z

The severe weather threat for Tornado Watch 503 continues.

SUMMARY...Large hail, some of which will be significant, and a
couple tornadoes will be the primary risks across western and
central OK into a part of North TX through 02Z. These hazards will
increase towards the I-35 corridor and the Oklahoma City metro area
near 00Z.

DISCUSSION...Splitting supercells have been evident centered from
Tillman to Washita counties as of 22Z ahead of a convective band
along the cold front across north-central OK into the Low Rolling
Plains of northwest TX. With middle 60s surface dew points and
MLCAPE of 1500-2500 J/kg within the inflow region, these
ahead-of-the-line supercells will have the greatest opportunity to
produce very large hail. The tornado threat should also increase
between 00-02Z as a southwesterly low-level jet strengthens.

..Grams.. 10/21/2017

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

ATTN...WFO...TSA...FWD...OUN...SJT...

LAT...LON   36879764 36869590 36419588 34369731 33369819 33259937
            33729980 34779999 35399971 36879764 

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