SPC MD 471

MD 0471 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR EASTERN KANSAS/WESTERN AND CENTRAL MISSOURI

MD 0471 Image


Mesoscale Discussion 0471
NWS Storm Prediction Center Norman OK
1242 AM CDT Sun May 20 2018

Areas affected...eastern Kansas/western and central Missouri

Concerning...Severe potential...Watch unlikely 

Valid 200542Z - 200815Z

Probability of Watch Issuance...20 percent

SUMMARY...Persistent thunderstorms are expected overnight, possible
in several different episodes.  Local/large hail is expected with
the strongest cells over the next several hours.

DISCUSSION...Latest radar loop shows a small cluster of convection
over extreme southeast Kansas -- moving eastward toward central
Missouri, with more widespread/weaker convection developing across a
larger portion of eastern Kansas and into western and central
Missouri.  The convection is slightly elevated, likely increasing in
response to a moderate south-southwesterly low-level jet and
associated warm advection/isentropic ascent.  

While mid-level westerly flow remains rather modest (around 30 kt),
very steep lapse rates (as observed by the evening SGF RAOB) are
contributing to moderate elevated instability (on the order of 2500
J/kg).  Thus, while shear would suggest only weakly rotating storms,
the amount of available instability suggests continued/persistent
storms with the strongest cells capable of producing hail generally
in the 1" to 1.75" range over the next several hours.

..Goss/Guyer.. 05/20/2018

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

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

LAT...LON   37019505 37409537 38219517 38829463 39239348 38959215
            38509164 37739181 36969288 36779438 37019505 

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SPC MD 468

MD 0468 CONCERNING SEVERE THUNDERSTORM WATCH 109… FOR PART OF EASTERN KS AND WESTERN MO

MD 0468 Image


Mesoscale Discussion 0468
NWS Storm Prediction Center Norman OK
0741 PM CDT Sat May 19 2018

Areas affected...Part of eastern KS and western MO

Concerning...Severe Thunderstorm Watch 109...

Valid 200041Z - 200215Z

The severe weather threat for Severe Thunderstorm Watch 109
continues.

SUMMARY...A stabilizing environment across the remaining portion of
WW 109 (south of I-70) should result in additional counties being
canceled from the watch or an overall early cancellation of the rest
of WW 109 are possible.

DISCUSSION...An extensive cirrus shield that expanded poleward from
the complex of storms that spread from southeast KS into southwest
and central MO late afternoon and early evening has stabilized much
of the environment across WW 109.  Although pockets of instability
remain near the cold front, which extended from eastern IA through
northwest MO and northeast KS to northwest OK, increasing
surface-based inhibition should continue to limit the development of
strong updrafts.  Meanwhile, a cluster of storms located over
central MO at 0030Z will advance further away from the southeast
portion of WW 109, precluding a severe-weather threat in this part
of the watch.

..Peters.. 05/20/2018

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

ATTN...WFO...SGF...EAX...TOP...ICT...

LAT...LON   38239309 37949541 38299635 38709614 38819545 38919301
            38239309 

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SPC MD 465

MD 0465 CONCERNING SEVERE THUNDERSTORM WATCH 108… FOR WEST AND NORTHWEST TX…WESTERN AND NORTHERN OK…SOUTHEAST KS…AND SOUTHWEST MO

MD 0465 Image


Mesoscale Discussion 0465
NWS Storm Prediction Center Norman OK
0611 PM CDT Sat May 19 2018

Areas affected...West and northwest TX...western and northern
OK...southeast KS...and southwest MO

Concerning...Severe Thunderstorm Watch 108...

Valid 192311Z - 200115Z

The severe weather threat for Severe Thunderstorm Watch 108
continues.

SUMMARY...Local WFO extensions in area are possible across parts of
south-central MO and in west TX.  Two areas of strong to severe
storms persist across the southern part of WW 108 (in northwest TX
to southwest OK) and northeast OK through southeast KS and southwest
MO.  Large hail and damaging winds should be the primary threats in
the short term, though a tornado cannot be ruled out in either of
these portions of the watch.

DISCUSSION......Northwest TX to south-central OK...
Water vapor imagery showed a progressive shortwave trough moving
through much of western TX late this afternoon.  Forcing for ascent
with this trough is aiding in continued thunderstorm development
near and north of a boundary extending from King County TX to
Cochran County TX.  Storm mergers across Cottle and Childress
counties TX appear to have formed into a cluster or attempts at
being linear.  All of these storms in northwest TX are located
within the strongest corridor of instability (MLCAPE 2000-2500 J/kg)
and the southern extent of effective bulk shear favorable for
supercells.  22Z mesoanalysis showed a boundary extending from
Cottle and Foard counties TX into south-central OK (north of
KSPS-KADM).  Given the current eastward movement of the
Cottle/Childress counties cluster and new rapid storm development in
Foard County TX, these storms should track to the east-northeast
into far southwest to south-central OK this evening. 

...West TX...
Additional sustained updrafts per radar imagery were forming to the
south-southwest between KLBB and KMAF in vicinity of the dryline. 
Trends in vertical wind profiles indicated backing of low-midlevel
winds (surface to 700-mb winds) resulting in an increase of surface
convergence along the dryline and providing some strengthening of
effective bulk shear to support storm organization.  Therefore, the
CAPE/shear parameter space is becoming more conducive to support
sustained updrafts and subsequent sever storm threat.  Counties in
WFO LUB area may need to be added to WW 108.

...Southwest to south-central MO...
A forward propagating MCS moving east at 40 kt is posing a
severe-weather threat for damaging winds across more of southern MO,
resulting in an areal extension of WW 108.  This bow may begin to
track to the east-southeast, near and north of a west-northwest to
east-southeast oriented outflow boundary located across southern MO,
where the strongest instability is located.

..Peters.. 05/19/2018

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

ATTN...WFO...SGF...EAX...TSA...TOP...ICT...OUN...SJT...LUB...
AMA...MAF...

LAT...LON   32660267 34130137 34460018 36069946 36509895 37089812
            37059659 38049538 38209389 38329264 38129190 37319174
            36639230 36489475 36429554 35959661 35319752 34749783
            34209816 33859851 33469929 32910088 32660267 

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SPC MD 463

MD 0463 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR NORTHEAST KANSAS…NORTHWEST MISSOURI…FAR SOUTHEAST NEBRASKA

MD 0463 Image


Mesoscale Discussion 0463
NWS Storm Prediction Center Norman OK
0142 PM CDT Sat May 19 2018

Areas affected...Northeast Kansas...northwest Missouri...far
southeast Nebraska

Concerning...Severe potential...Watch likely 

Valid 191842Z - 192115Z

Probability of Watch Issuance...80 percent

SUMMARY...Scattered storms are likely to form by 20-21Z, and a watch
may be needed for hail, wind, and a tornado or two.

DISCUSSION...A cold front is currently progressing across central
KS, while a leading wind shift dissipates along a MHK to HUT line.
Visible imagery shows widespread heating now, in the wake of the
earlier convection with cirrus finally existing northeast KS. As a
result, temperatures are steadily rising through the mid to upper
70s F, with expanding CU fields.

Boundary layer moisture quality is questionable given the previous
overturning of the air mass, however, lapse rates aloft are quite
steep, and will support severe storms. Weak low-level flow beneath
50 kt southwesterly midlevel flow is resulting in primarily
straightline hodographs. However, any backing or strengthening of
the low-level flow due to pressure falls could easily support
supercells.

Storms may initiate near the cold front around SLN/CNK, and perhaps
along the stationary front to the north, initially cellular and
possibly evolving into an MCS as they approach northwest MO into
southern IA.

..Jewell/Weiss.. 05/19/2018

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

ATTN...WFO...EAX...OAX...TOP...ICT...

LAT...LON   38619778 39209780 39689756 40029696 40209640 40469537
            40439479 40029432 39209429 38949490 38339713 38619778 

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SPC MD 459

MD 0459 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PARTS OF NORTHEAST OKLAHOMA…SOUTHEAST KANSAS…AND EASTWARD INTO CENTRAL MISSOURI

MD 0459 Image


Mesoscale Discussion 0459
NWS Storm Prediction Center Norman OK
0750 AM CDT Sat May 19 2018

Areas affected...parts of northeast Oklahoma...southeast
Kansas...and eastward into central Missouri

Concerning...Severe potential...Watch unlikely 

Valid 191250Z - 191445Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated hail exceeding severe levels may occur over the
next few hours with isolated stronger/elevated storms.

DISCUSSION...Latest radar loop shows regeneration of elevated
convection over the past hour, atop a remnant outflow from prior
convection.  The storms are occurring near the nose of a veering of
the low-level jet, within an environment featuring steep mid-level
lapse rates -- and thus moderate elevated CAPE.

Shear through the cloud-bearing layer is not particularly strong,
with generally unidirectional southwest flow.  As such, storms
should remain only weakly organized -- with perhaps occasional/weak
mid-level rotation.  Further, as the low-level jet diminishes
through the morning, storms should eventually decrease in intensity
as well.  In the mean time however, hail generally in the 1 to 1.5"
range may occur with the most vigorous storms.

..Goss/Guyer.. 05/19/2018

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

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

LAT...LON   38319185 37439211 36879371 36709425 36299605 36389647
            36939670 37779663 38319570 38759439 39049274 38319185 

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SPC MD 458

MD 0458 CONCERNING SEVERE THUNDERSTORM WATCH 105…106… FOR MUCH OF KANSAS…FAR EASTERN COLORADO…AND FAR SOUTHERN NEBRASKA

MD 0458 Image


Mesoscale Discussion 0458
NWS Storm Prediction Center Norman OK
1055 PM CDT Fri May 18 2018

Areas affected...Much of Kansas...far eastern Colorado...and far
southern Nebraska

Concerning...Severe Thunderstorm Watch 105...106...

Valid 190355Z - 190500Z

The severe weather threat for Severe Thunderstorm Watch 105, 106
continues.

SUMMARY...The severe threat continues across WWs 105 and 106,
although this threat appears to be on the wane.  Isolated instances
of severe wind and hail remain possible through at least 04Z across
western Kansas, and 05Z across central Kansas.

DISCUSSION...The overall severe threat has diminished some across
WWs 105 and 106 over the past hour or so due to a couple of
influences: 1) nocturnal boundary layer stabilization, and 2)
widespread convective overturning.  Nevertheless, one persistent
linear segment continues across northwestern Kansas currently and
will have a threat for damaging wind gusts for the next hour or so. 
Given ongoing destabilization, portions of WW 105 in effect for
these areas may be allowed to expire at its originally scheduled
time (04Z).

Farther south, isolated thunderstorms have redeveloped from
southwest Kansas southward into the Texas Panhandle.  Although
low-level stabilization has occurred across these areas, steep
mid-level lapse rates will continue to sustain elevated storms and a
few instances of large hail may still occur.

Farther east, an extensive line of storms extending from near
Russell to just west of Wichita continued to propagate eastward into
a weakly to moderately unstable airmass (MUCAPE values between
1000-2000 J/kg).  An isolated damaging wind threat should continue
through the originally scheduled expiration time of WW 106 (07Z),
and some hail threat will exist with more cellular convection
developing on the southern flank of this linear MCS across far
southern Kansas and extreme northern Oklahoma.

..Cook.. 05/19/2018

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

ATTN...WFO...TOP...ICT...OUN...GID...DDC...GLD...AMA...

LAT...LON   36930025 37030055 37480105 37960184 38500190 39000209
            39270222 39780228 40090192 40260133 40320037 40359944
            40309894 39979841 39379783 38819729 38299691 37839679
            37449672 37099696 36939745 36849827 36859913 36930025 

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SPC MD 435

MD 0435 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF EASTERN OKLAHOMA…WESTERN ARKANSAS…AND FAR NORTHEASTERN TEXAS

MD 0435 Image


Mesoscale Discussion 0435
NWS Storm Prediction Center Norman OK
1121 AM CDT Wed May 16 2018

Areas affected...Portions of eastern Oklahoma...western
Arkansas...and far northeastern Texas

Concerning...Severe potential...Watch unlikely 

Valid 161621Z - 161845Z

Probability of Watch Issuance...20 percent

SUMMARY...Two MCVs over central and eastern Oklahoma are expected to
contribute to scattered thunderstorm development over the next few
hours. Severe wind gusts and marginally severe hail are the primary
threats.  A Severe Thunderstorm Watch is not anticipated at this
time, but conditions will be monitored closely.

DISCUSSION...Overnight convection has once again produced MCVs over
the area, partially as an enhancement of a subtle mid-level
perturbation moving over the top of the building ridge.  The 12z OUN
raob sampled the enhancement in mid-level flow associated with these
MCVs with wind speeds > 40 kt in the 650-500 mb layer and a peak
wind of 55 kt at 565 mb.  Moderate sub-tropical flow in upper
levels, perhaps enhanced by a separate area of convection over the
Texas panhandle, also is impinging on the area and is producing
moderate diffluence aloft.  Southeast and east of the MCVs, strong
heating is occurring on either side of a dying stationary front
amidst surface dewpoints in the upper 60s to low 70s.  

The above factors suggest thunderstorms will increase no later than
early afternoon over the area, which is supported by recent HRRR
guidance.  While the background wind/vertical shear would suggest
weakly organized thunderstorm clusters, the enhancement in vertical
shear and mesoscale lift provided by the MCVs is expected to produce
some convective organization in the form of a small MCS with perhaps
some transient bowing clusters.  Despite some convective overturning
in previous days, moderate mid-level lapse rates remain over the
area, and boundary-layer moisture is sufficient to support moderate
instability --1500-2000 J/kg of MLCAPE by early afternoon.  The
primary threat will be severe wind gusts with any of the storms,
particularly those that develop more persistent rotation.  A
marginally severe hail threat will also accompany the cells that
show some rotation.  While the extent of the severe coverage is not
expected to warrant a Severe Thunderstorm Watch at this time, trends
in both storm coverage and intensity will be monitored closely.

..Coniglio/Weiss.. 05/16/2018

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

ATTN...WFO...LZK...SHV...TSA...FWD...OUN...

LAT...LON   36239526 36439439 36399322 36149238 36029225 35599205
            34579198 34049219 33589254 33159319 33049402 33169465
            33509525 34119568 34529586 34819591 35239589 35399584
            35949564 36239526 

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SPC Center Public Severe Weather Outlook (PWO)

Public Severe Weather Outlook

PWO Image

PUBLIC SEVERE WEATHER OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1129 AM CDT TUE MAY 15 2018

...Severe thunderstorms expected over parts of the northeast US this
afternoon...

* LOCATIONS...
  Southern New York
  Northeast Pennsylvania
  Connecticut
  Massachusetts
  Northern New Jersey
  Northern Rhode Island

* HAZARDS...
  Widespread damaging winds
  A few tornadoes
  Scattered large hail

* SUMMARY...
  Widespread damaging winds, a few tornadoes, and scattered large
  hail are expected across parts of the Northeast States this
  afternoon into early evening.

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 watch
means that conditions are favorable for severe thunderstorms
over the next several hours. If a severe thunderstorm warning is
issued for your area, move to a place of safety, ideally in an 
interior room on the lowest floor of a sturdy building.

&&

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SPC MD 419

MD 0419 CONCERNING SEVERE THUNDERSTORM WATCH 89…91… FOR EASTERN KS…WESTERN/CENTRAL MO…NORTHEAST OK

MD 0419 Image


Mesoscale Discussion 0419
NWS Storm Prediction Center Norman OK
0715 PM CDT Mon May 14 2018

Areas affected...Eastern KS...Western/Central MO...Northeast OK

Concerning...Severe Thunderstorm Watch 89...91...

Valid 150015Z - 150145Z

The severe weather threat for Severe Thunderstorm Watch 89, 91
continues.

SUMMARY...The risk for scattered severe thunderstorms continues
across WW 89. Some threat may extend outside of the watch into
northeast OK and southwest MO.

DISCUSSION...Scattered severe thunderstorms continue across portions
of eastern KS and western MO at 00Z. The strongest storm is
affecting Cowley County KS, with very large hail and at least one
tornado reported within the last hour. This storm is beginning to
move southeastward into northern OK, and the severe threat will
likely spread into the far northeast part of WW 91, and also into
Osage County OK, where no watch is in effect. Given the isolated
nature of the storm and its relatively slow movement, downstream
watch issuance is not anticipated in the short term across northeast
OK. 

Further east, a couple of small bowing segments have developed over
western/central MO, one northwest of Springfield and the other west
of Columbia. Some damaging wind threat will exist in the short term
with these bowing segments, though a weakening trend is expected
this evening, given relatively weak midlevel flow/effective shear
(as noted on 00Z SGF sounding) and increasing SB CINH. 

Elsewhere across WW 89, storms will likely continue into at least
mid-evening, with redevelopment possible on various outflows across
the region, though a gradual decreasing trend is expected as diurnal
cooling commences.

..Dean/Hart.. 05/15/2018

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

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

LAT...LON   36659643 37099750 37479754 38699661 38939508 39109242
            38629141 38289099 37929099 37289144 36889279 36799389
            36699504 36659601 36659643 

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