SPC MD 1728

MD 1728 CONCERNING SEVERE THUNDERSTORM WATCH 502… FOR EASTERN KANSAS AND WESTERN MISSOURI

MD 1728 Image


Mesoscale Discussion 1728
NWS Storm Prediction Center Norman OK
0810 PM CDT Sat Oct 21 2017

Areas affected...Eastern Kansas and western Missouri

Concerning...Severe Thunderstorm Watch 502...

Valid 220110Z - 220245Z

The severe weather threat for Severe Thunderstorm Watch 502
continues.

SUMMARY...An isolated severe wind risk persists across remaining
portions of WW 502.  A new WW is being considered downstream of WW
502 - particularly for portions of southeastern Kansas and
southwestern Missouri.

DISCUSSION...A line of storms continues to propagate eastward across
portions of WW 502 - generally along a line from near LWD to MKC to
CNU.  Most of the line has been sub-severe over the past hour or so,
although a 59 mph wind gust was reported in Burbank, OK recently -
and that storm should propagate into southern portions of WW 502
with time.  This isolated severe wind risk - most concentrated in
southeastern Kansas and vicinity - will eventually reach the eastern
extent of the the watch over the next 1-1.5 hours.  A new severe
thunderstorm watch is being considered as ongoing convection - aided
by 1000-1500 J/kg MLCAPE and an increasing low-level jet across the
region - approaches southwestern Missouri.

..Cook.. 10/22/2017

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

ATTN...WFO...LSX...SGF...DMX...EAX...TSA...TOP...ICT...

LAT...LON   40639324 40439391 39279498 37549647 37189654 37009571
            36959499 36909458 36519458 36529347 36509267 37429252
            38919258 40249302 40639324 

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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 1722

MD 1722 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR WESTERN AND CENTRAL OK AND PART OF WESTERN NORTH TX

MD 1722 Image


Mesoscale Discussion 1722
NWS Storm Prediction Center Norman OK
0236 PM CDT Sat Oct 21 2017

Areas affected...Western and central OK and part of western North TX

Concerning...Severe potential...Watch likely 

Valid 211936Z - 212130Z

Probability of Watch Issuance...95 percent

SUMMARY...A new severe-weather watch will be coordinated soon across
portions of the southern Plains.  Thunderstorms are expected to
develop by late afternoon across western Oklahoma and into parts of
western North Texas, with storms becoming severe producing large
hail and perhaps a tornado with the initial activity.  Damaging
winds will become a greater threat as storms form a line, advancing
east across central Oklahoma into the evening.

DISCUSSION...Despite the lack of lightning so far, trends in visible
satellite imagery indicated sustained and deepening convection along
the portion of the cold front advancing southward through western OK
with some cooling of cloud tops.  Farther south into western North
TX, visible imagery indicated likely surface-based cumulus clouds
forming from southeast of CDS into Wilbarger County.  Objective
analyses indicated an increase of low-level convergence across this
latter area and the cold front, as a dryline shifts east through
northwest TX.  The warm sector has become moderately unstable
(MLCAPE 2000-2500 J/kg) with weakening of surface-based inhibition
per objective analyses along and just east of the surface
boundaries.  Additional surface heating and an increase in
large-scale ascent, as an upper trough moves east into the southern
Plains, are expected to aid in further weakening of the cap and
strengthening storm development from late this afternoon through the
evening.

An increase in deep-layer shear will support supercells with the
initial activity across western OK and western North TX, while
upscale growth is expected into the evening, with damaging winds
becoming the primary threat as a squall line evolves into central
OK.

..Peters/Thompson.. 10/21/2017

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

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

LAT...LON   34299996 35599953 36949829 36949689 36919663 36229668
            35069706 34159745 33689809 33519899 33849990 34299996 

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SPC MD 1721

MD 1721 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR EASTERN KANSAS…FAR SOUTHEAST NEBRASKA…FAR SOUTHWEST IOWA AND NORTHWEST MISSOURI

MD 1721 Image


Mesoscale Discussion 1721
NWS Storm Prediction Center Norman OK
0123 PM CDT Sat Oct 21 2017

Areas affected...eastern Kansas...far southeast Nebraska...far
southwest Iowa and northwest Missouri

Concerning...Severe potential...Watch likely 

Valid 211823Z - 212100Z

Probability of Watch Issuance...95 percent

SUMMARY...Thunderstorms are expected to develop along the
east-southeastward progressing cold front across eastern Kansas
later this afternoon. Once initiation occurs, storms will quickly
intensify with damaging wind gusts, hail and a tornado or two
possible into the evening hours. A watch will likely be needed by
20-21z.

DISCUSSION...Breaks in low level clouds have allowed temperatures to
warm into the mid to upper 70s across much of eastern KS early this
afternoon. With dewpoints in the low and mid 60s, MLCAPE values have
increased to 1500-2000 J/kg. The VAD wind profile from the DDC radar
also has shown a slight increase in midlevel winds over the last 30
minutes or so, suggesting the shortwave impulse over northeast NM is
beginning to eject east/northeast into the Plains. Furthermore,
cumulus along the front from far northwest OK into central/eastern
KS and southeast NE is becoming increasingly congested with some
vertical growth evident. In conjunction with hi-res HRRR guidance,
this suggests convective initiation should occur within the next
couple of hours.

Steep midlevel lapse rates and effective shear in excess of 35 kt
will aid in storms quickly becoming severe with at least a brief
window of opportunity for semi-discrete cells. However, the quickly
progressing cold front and front-parallel deep-shear vectors will
result in rather fast upscale growth. Any cells that can stay
semi-discrete will pose a threat for large hail and damaging wind.
Once upscale growth occurs, a transition to mainly a damaging wind
threat is expected. While forecast low-level hodographs are
unimpressive, they are adequate for low-end tornado potential and a
tornado or two can not be ruled out either in an isolated cell or
within embedded mesovorticies along the leading edge of the squall
line. A watch will likely be needed between 20-21z.

..Leitman/Thompson.. 10/21/2017

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

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

LAT...LON   37799510 37369554 37069617 37049691 37009757 37059809
            37249826 37629815 37879805 38379762 39069719 39599690
            40569669 41019645 41289596 41299538 41179467 40929423
            40579408 40009408 38909433 38309470 37799510 

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