SPC MD 1304

MD 1304 CONCERNING SEVERE THUNDERSTORM WATCH 338… FOR PARTS OF CENTRAL KANSAS

MD 1304 Image


Mesoscale Discussion 1304
NWS Storm Prediction Center Norman OK
0954 PM CDT Thu Aug 16 2018

Areas affected...Parts of central Kansas

Concerning...Severe Thunderstorm Watch 338...

Valid 170254Z - 170430Z

The severe weather threat for Severe Thunderstorm Watch 338
continues.

SUMMARY...Lingering thunderstorm activity and associated risk for
mainly severe hail is expected to gradually diminish late this
evening.  An additional severe weather watch is not anticipated.

DISCUSSION...A low-level baroclinic zone remains a focus for strong
to severe thunderstorm development near and east/southeast of
Salina.  This appears to be supported by a corridor of residual
moderate boundary layer instability (CAPE in excess of 2000 J/kg),
in the presence of  moderate to strong deep layer shear beneath
30-40 kt northwesterly 500 mb flow.  With the continuing progression
of the mid-level closed low into the middle Mississippi Valley and,
perhaps more importantly, continuing boundary layer cooling and
gradual stabilization, the lingering risk for severe hail and
locally strong surface gusts is expected to diminish through the
04-05Z time frame.

..Kerr.. 08/17/2018

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

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

LAT...LON   39019803 38969609 38649496 37639558 37629672 38259796
            39019803 

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SPC MD 1303

MD 1303 CONCERNING SEVERE THUNDERSTORM WATCH 338… FOR PARTS OF EASTERN KANSAS/WESTERN MISSOURI/NORTHEASTERN OKLAHOMA/NORTHWEST ARKANSAS

MD 1303 Image


Mesoscale Discussion 1303
NWS Storm Prediction Center Norman OK
0552 PM CDT Thu Aug 16 2018

Areas affected...Parts of eastern Kansas/western
Missouri/northeastern Oklahoma/northwest Arkansas

Concerning...Severe Thunderstorm Watch 338...

Valid 162252Z - 170015Z

The severe weather threat for Severe Thunderstorm Watch 338
continues.

SUMMARY...Thunderstorm activity will continue to develop across the
watch area and pose some risk for severe hail and wind into the 7-8
PM time frame.  Thereafter, continuing severe weather potential
remains unclear, but it is possible that another watch could become
necessary to the east, across parts of southern Missouri and
adjacent northern Arkansas.

DISCUSSION...Thunderstorm activity continues to increase to the
southeast of the Interstate 35 corridor of eastern Kansas.  This
activity appears focused along a weak baroclinic zone near the
southern periphery of a mid-level closed low now digging across the
middle Missouri Valley, where 30-40+ kt westerly 500 mb flow is
contributing to moderately strong deep layer shear.

Into the the early evening hours, it does appear that a gradual
merger/consolidation of this activity with vigorous thunderstorms
now developing along northeastward advancing convective outflow
(emanating from north central Oklahoma) will continue east of
Wichita, across the Chanute area into the southern Kansas/Missouri
border vicinity.  Subsequent evolution and the potential for an
appreciable continuing risk for severe hail and wind remain unclear
thereafter, due to generally weak low-level forcing for maintaining
convective development.  However, it appears at least possible that
one prominent surface cold pool could eventually emerge and maintain
vigorous convective development on its leading/eastern edge, tending
to propagate southeastward across the Interstate 44 corridor of
southwest Missouri, in the presence of 20-30 kt westerly deep layer
mean flow.

..Kerr.. 08/16/2018

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

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

LAT...LON   38739272 38299187 37199141 36349172 36139302 36339431
            36439490 36839606 37799724 38579564 38879336 38739272 

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SPC MD 1302

MD 1302 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR NORTHEAST KANSAS…NORTHWEST MISSOURI

MD 1302 Image


Mesoscale Discussion 1302
NWS Storm Prediction Center Norman OK
0312 PM CDT Thu Aug 16 2018

Areas affected...Northeast Kansas...northwest Missouri

Concerning...Severe potential...Watch likely 

Valid 162012Z - 162115Z

Probability of Watch Issuance...95 percent

SUMMARY...Scattered strong storms, some producing severe hail and
gusty winds, are expected within the next few hours. Issuance of a
Severe Thunderstorm Watch is likely soon.

DISCUSSION...Convective initiation has recently occurred just to the
west of TOP, south of a cold front, with additional storms expected
(as indicated by recent CAM guidance) over the next few hours.
Though directional low-level shear is present, 925-850 mb flow is
rather weak, with unidirectional shear present mainly above 850 mb.
Still, steep mid-level lapse rates on the order of 7.0+ C/km,
resulting in 1500+ J/kg MLCAPE, and 40 knots of effective bulk shear
suggest that organized updrafts are possible, with large hail a
concern. A few damaging wind gusts also cannot be ruled out,
especially given deep moisture throughout the troposphere (PWAT
values over 1.8 inches in many locales), which may promote wet
downbursts.

Given the relatively strong forcing for ascent associated with the
cold front and the propensity for multiple storms to develop in a
relatively favorable sheared/unstable environment, a Severe
Thunderstorm Watch will likely be issued for both the highlighted
area, and the region discussed in MCD 1301.

..Squitieri/Hart.. 08/16/2018

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

ATTN...WFO...EAX...TOP...

LAT...LON   38779537 38929598 39309627 39829620 39929608 39909557
            39969514 40219428 39929361 39449331 38859366 38779537 

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SPC MD 1301

MD 1301 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR CENTRAL/EASTERN OKLAHOMA…SOUTHEAST KANSAS

MD 1301 Image


Mesoscale Discussion 1301
NWS Storm Prediction Center Norman OK
0218 PM CDT Thu Aug 16 2018

Areas affected...Central/eastern Oklahoma...Southeast Kansas

Concerning...Severe potential...Watch possible 

Valid 161918Z - 162145Z

Probability of Watch Issuance...40 percent

SUMMARY...Isolated severe thunderstorms are possible during the
mid-late afternoon hours. Large hail and damaging gusty winds are
the primary threats. Convective trends are being monitored for the
potential issuance of a Severe Thunderstorm Watch.

DISCUSSION...A well-defined MCV, currently centered over northwest
Oklahoma, is propagating eastward, with scattered thunderstorms
ongoing across Alfalfa to Kingfisher Counties. Additional cells are
initiating along a surface boundary, where a pooling of higher
dewpoints (mid 70s F) were observed, roughly located from north of
END to GCM. 

The MCV is progressing eastward into an increasingly unstable
airmass, characterized by 1500-2000+ J/kg MLCAPE, mainly driven by
deep low-level moisture (72-75 F dewpoints) and noticeably steep low
and mid-level lapse rates of 6.5-7.5 C/km. Effective bulk shear
values are stronger in the northern regions of the discussion area
(i.e 30 knots), with weaker values (20 knots) farther south. 

Current thinking is that the greatest concentration of storms will
occur ahead of the MCV, along the aforementioned surface boundary,
where congealment into a multicellular complex is likely. Damaging
wind gusts associated with downbursts from water-loaded downdrafts
are more likely with the most intense storms. In addition, the
relatively steep 700-500 mb level lapse rates (evident via the 18Z
TOP special sounding) may also promote the generation of severe
hail, especially with some of storms associated with the stronger
deep-layer shear to the north. 

Confidence regarding the coverage of severe wind and hail are a bit
uncertain at this time, and convective trends are being monitored
for the potential issuance of a Severe Thunderstorm Watch as details
of severe coverage become more clear.

..Squitieri/Hart.. 08/16/2018

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

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

LAT...LON   35959797 36219805 36529807 37239787 38749752 38979662
            38609548 38109518 37429508 36849481 36389475 35759482
            35659592 35669672 35729736 35779788 35959797 

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SPC MD 1273

MD 1273 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF THE SOUTHERN PLAINS AND MID MISSOURI/MISSISSIPPI VALLEYS

MD 1273 Image


Mesoscale Discussion 1273
NWS Storm Prediction Center Norman OK
0456 PM CDT Fri Aug 10 2018

Areas affected...Portions of the Southern Plains and Mid
Missouri/Mississippi Valleys

Concerning...Severe potential...Watch unlikely 

Valid 102156Z - 110030Z

Probability of Watch Issuance...5 percent

SUMMARY...Thunderstorms continue to develop along/near a surface
boundary and an upper-level trough axis. Strong wind gusts are
possible.

DISCUSSION...Scattered pulse thunderstorms continue to develop
across this region in the vicinity of a surface boundary and
upper-level trough axis. Storms are forming in a moderately buoyant
environment (1500-2500 J/kg), but without strong shear and flow
aloft, a pulse storm mode should continue as outflow from
dissipating storms will help generate new storms. Strong daytime
heating has destabilized lower-levels and DCAPE of 1000+ J/kg
indicate the potential for strong wind gusts. Some severe wind
reports have already occurred in Oklahoma and the wind threat should
continue until around sunset when activity is likely to decrease.
The convection should remain unorganized and the overall severe wind
threat is limited/isolated, therefore, a watch is unlikely.

..Nauslar/Grams.. 08/10/2018

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

ATTN...WFO...LSX...LZK...SGF...EAX...TSA...TOP...ICT...OUN...
DDC...AMA...

LAT...LON   36450011 35540060 34960030 34479958 34569880 34909741
            34949541 35459465 35989411 36589312 36989247 37299193
            37699116 38199035 38669002 39039027 39159154 38859334
            37989600 37369830 37279852 36999968 36450011 

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