SPC MD 712


MD 0712 Image

Mesoscale Discussion 0712
NWS Storm Prediction Center Norman OK
1233 AM CDT Tue Jun 12 2018

Areas affected...Southeast Kansas...Northern Oklahoma...Western

Concerning...Severe Thunderstorm Watch 173...

Valid 120533Z - 120730Z

The severe weather threat for Severe Thunderstorm Watch 173

SUMMARY...The severe threat ongoing in eastern Kansas will likely
continue for several more hours. Large hail and wind damage can be
expected with the stronger thunderstorms associated with the MCS.
Additional watch issuance may be needed across southeast Kansas as
the expiration of WW 173 takes place at 1 am CDT. The threat is
expected to become marginal across northern Oklahoma where a weather
watch probably will not be needed.

DISCUSSION...A linear MCS is currently moving southeastward into a
strongly unstable airmass across eastern Kansas and western Missouri
where the RAP is showing MLCAPE values in the 3000 to 4000 J/kg
range. This will likely fuel the MCS for several more hours as it
moves southeastward into the stronger instability. Although
deep-layer shear on regional WSR-88D VWPs is only around 30 kt, 850
mb flow will be maintained or gradually strengthen across southeast
Kansas over the next few hours. This along with the instability and
shear will likely maintain a severe threat with the stronger
thunderstorms. Large hail will be most likely with lingering
supercells. Wind damage will also be possible along the leading edge
of the MCS. The severe threat is expected to become marginal as the
storms reach northern Oklahoma and southwest Missouri later tonight.

..Broyles/Thompson.. 06/12/2018

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


LAT...LON   38789366 38889493 38779566 38309664 37959774 37809815
            37579840 36999855 36309846 35809822 35489788 36349569
            36829401 37339299 38449305 38789366 

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SPC MD 711


MD 0711 Image

Mesoscale Discussion 0711
NWS Storm Prediction Center Norman OK
0932 PM CDT Mon Jun 11 2018

Areas affected...northeast Kansas...northwest Missouri...southern

Concerning...Severe Thunderstorm Watch 172...173...

Valid 120232Z - 120430Z

The severe weather threat for Severe Thunderstorm Watch 172, 173

SUMMARY...A threat of damaging wind and hail continues across the
watch area, and may extend into the remainder of southeast Kansas
and western Missouri this evening.

DISCUSSION...An MCS stretches from northeast KS into south central
IA as of 0230Z. Northern portions of the line previously contained
measured severe winds, but, may begin to weaken a bit as the most
unstable air remains to the southwest. The bulk of the MCS was
beginning to propagate in a more southerly direction, with locally
damaging outflow winds along with embedded hail cores. A very
unstable air mass extends from OK across eastern KS, and this air
mass should maintain the MCS as it travels across the severe
thunderstorm watch. Another watch may be needed later this evening
for portions of southeast KS and western MO, should the storms still
be severe at that time. 

Farther north into central IA, the threat appears more marginal for
both wind and hail, with a gradual weakening trend expected as these
storms encounter a stabilizing air mass due to cool east winds.

..Jewell.. 06/12/2018

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


LAT...LON   38799704 39469663 39929558 40169467 40459417 40819399
            40919351 40649296 39799270 38909261 38329300 37889357
            37629427 37549491 37639559 37879638 38129679 38799704 

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SPC MD 707


MD 0707 Image

Mesoscale Discussion 0707
NWS Storm Prediction Center Norman OK
0341 PM CDT Mon Jun 11 2018

Areas affected...Central/North-central KS

Concerning...Severe potential...Watch possible 

Valid 112041Z - 112245Z

Probability of Watch Issuance...40 percent

SUMMARY...Severe thunderstorms may develop across north-central and
central KS this afternoon. Trends are being monitored for possible
watch issuance.

DISCUSSION...Recent visible satellite imagery shows an increasing
agitated cu field along and just ahead of the approaching cold
front. Airmass south of the front is well-mixed with temperatures in
the upper 90s/low 100s and dewpoints in the mid 60s. This mixing has
eroded much the convective inhibition and the expectation is for
continued convergence along the cold front to result in eventual
convective initiation. However, given the amount of dry mid-level
air (sampled well by the 19Z TOP sounding), there is some question
as to how long it will be before this initiation takes place.
Additionally, convergence decreases with southern extent across KS,
casting uncertainty regarding the occurrence of thunderstorms into
central KS in the near-term. As a result, a conditional risk for
severe hail and wind exists across north-central/central KS. Trends
will be monitored for convective development and possible watch

..Mosier/Grams.. 06/11/2018

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


LAT...LON   38389716 38059764 37899809 37849847 38009882 38369890
            39089838 39659799 39939767 39919668 38869682 38389716 

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SPC MD 706


MD 0706 Image

Mesoscale Discussion 0706
NWS Storm Prediction Center Norman OK
0238 PM CDT Mon Jun 11 2018

Areas affected...Eastern NE...Far Western IA

Concerning...Severe potential...Tornado Watch likely 

Valid 111938Z - 112145Z

Probability of Watch Issuance...95 percent

SUMMARY...Severe thunderstorms capable of all severe hazards,
including tornadoes, are expected to begin developing within the
next 2 hours. A Tornado Watch will likely be needed.

DISCUSSION...Cumulus field continues to increases within the narrow
warm sector across eastern NE, just ahead of an approaching cold
front. Recent surface analysis places a low about 30 mi north of YKN
in far southeast SD, with a cold front extending southwestward
across eastern NE and into central KS. A warm front also extends
southeastward from the low across far southwest IA and
north-central/northwest MO. High-resolution visible satellite
imagery also appears to reveal a southwestward progressing outflow
boundary beneath the thicker clouds over far southeast SD.

Warm-sector between these features is characterized by temperatures
in the upper 80s, dewpoints in upper 60s/low 70s, and strong
instability. Latest mesoanalysis estimates MLCAPE over 3000 J/kg
with little, if any, convective inhibition remaining immediately
ahead of the front. Consequently, continued convergence in this
environment will likely lead to convective initiation within the
next hour or so. Once this occurs, rapid thunderstorm development is
anticipated with storms quickly becoming severe. Primary severe
threat appears to be large hail, some of which could be greater than
2 inches in diameter. Additionally, the favorable low-level shear
may contribute to some increased tornado potential as well. Tall,
water-loaded updrafts will also result in a threat for strong wind
gusts. A watch will likely be needed across portions of the area to
address this anticipated severe threat.

..Mosier/Grams.. 06/11/2018

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


LAT...LON   41289559 40419574 39979614 40079761 40569777 42139733
            42979720 43059661 42869590 42209555 41289559 

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SPC MD 679


MD 0679 Image

Mesoscale Discussion 0679
NWS Storm Prediction Center Norman OK
0251 AM CDT Sat Jun 09 2018

Areas affected...Eastern Nebraska...Western Iowa

Concerning...Severe potential...Watch possible 

Valid 090751Z - 090945Z

Probability of Watch Issuance...40 percent

SUMMARY...A wind damage threat will likely continue for a couple
more hours across parts of eastern Nebraska. The severe threat may
affect Iowa but the wind damage threat with the line is expected to
become more isolated with time. Due to the continued severe threat,
weather watch issuance still can not be ruled out.

DISCUSSION...The latest radar imagery shows an MCS over east-central
Nebraska with a well-defined outflow boundary surging southeastward
away from the line in southern Nebraska. Over the last hour, several
measured severe wind gusts have been observed, notably at Aurora,
Kearney and York. Moderate instability is analyzed ahead of the line
by the RAP with MLCAPE estimated in the 2500 J/kg near Omaha. This
should enable the line to continue to have a wind damage threat for
a couple more hours. However, a gradual decrease in the threat is
expected to take place as the MCS approaches western Iowa.

..Broyles/Thompson.. 06/09/2018

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


LAT...LON   42439505 42109439 41689429 41219469 40799522 40139581
            39869650 40259739 40859806 41579803 42739659 42439505 

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SPC MD 659


MD 0659 Image

Mesoscale Discussion 0659
NWS Storm Prediction Center Norman OK
0158 AM CDT Thu Jun 07 2018

Areas affected...Central KS...North-central OK

Concerning...Severe potential...Watch possible 

Valid 070658Z - 070830Z

Probability of Watch Issuance...60 percent

SUMMARY...The threat for large hail and strong winds gusts will
likely persist across central KS for the next several hours and a
watch may be needed.

DISCUSSION...Thunderstorms have developed rapidly along the eastern
edge of the low-level jet over the past hour or so. In this area,
steep mid-level lapse rates are contributing to moderate to strong
instability and warm-air advection is lifting parcels to their LFC.

Additionally, southeastward progressing MCS moving through northwest
KS has begun to interact with the newly developed warm-air advection
storms. Expectation is for this storm interact to result in
increased forward propagation into central KS and a higher
probability for damaging wind gusts.

Initially disorganized cluster across southwest KS has become
increasingly more organized over the past hour. As a result, the
reflectivity gradient along the leading edge has become
significantly sharper as storms have increased in strength.
Furthermore, recent velocity data from KDDC reveals strong westerly
winds in the wake of the system, indicative of a strong rear-inflow
jet. MCS strengthening and maintenance is anticipated as this system
continues eastward across south-central KS. Some development
southward into north-central OK is possible.

..Mosier/Thompson.. 06/07/2018

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


LAT...LON   37890014 39780030 39959786 39179729 36359748 36980024

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