SPC MD 1083

MD 1083 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR PORTIONS OF NORTHERN/EASTERN KANSAS

MD 1083 Image


Mesoscale Discussion 1083
NWS Storm Prediction Center Norman OK
1137 AM CDT Thu Jul 19 2018

Areas affected...Portions of northern/eastern Kansas

Concerning...Severe potential...Watch possible 

Valid 191637Z - 191830Z

Probability of Watch Issuance...60 percent

SUMMARY...Developing thunderstorms over northern Kansas may
gradually spread east/southeastward through this afternoon. Some of
these storms will be capable of damaging winds and large hail. A
watch could be needed within the next 1-2 hours.

DISCUSSION...A cluster of thunderstorms has formed within a field of
ACCAS over north-central Kansas late this morning. This convective
development suggests that subtle forcing for ascent within
northwesterly flow is beginning to advance across northern Kansas.
As it does so, isolated to scattered convective initiation is
possible farther east along a surface theta-e ridge/confluence axis
extending towards the Missouri Valley. Adjusting the 12Z TOP
sounding for current conditions suggests strong buoyancy (e.g.,
MLCAPE upwards of 3000 J/kg) is already present. In turn, robust
updraft accelerations and strong thunderstorm cores will remain
possible.

Relatively straight hodographs (somewhat parallel to the corridor of
initiation as well) suggest clusters of splitting cells will be the
preferred mode. The steep lapse rate environment and hot boundary
layer will be favorable for strong cold pool generation, and this
may encourage a few bowing segments that advance east/southeast
within the northwesterly flow environment. As such, damaging winds
will be the primary threat, although embedded supercell structures
will yield the potential for large hail as well.

Due to the subtle nature of large-scale ascent, there is some
uncertainty in the timing/coverage of downstream convection.
However, the severe threat appears to be increasing sufficiently
such that a watch may be needed within the next 1-2 hours.

..Picca/Guyer.. 07/19/2018

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

ATTN...WFO...SGF...EAX...TOP...ICT...GID...DDC...GLD...

LAT...LON   39359975 39739983 39939959 39939716 39869656 39689541
            39429493 38889461 38219471 37919480 37449564 37509629
            38079729 38539880 39359975 

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SPC MD 1080

MD 1080 CONCERNING SEVERE POTENTIAL…WATCH LIKELY FOR EAST/SOUTHEAST NE…FAR NORTHEAST KS…FAR SOUTHWEST IA…FAR NORTHWEST MO

MD 1080 Image


Mesoscale Discussion 1080
NWS Storm Prediction Center Norman OK
1247 AM CDT Thu Jul 19 2018

Areas affected...East/Southeast NE...Far Northeast KS...Far
Southwest IA...Far Northwest MO

Concerning...Severe potential...Watch likely 

Valid 190547Z - 190745Z

Probability of Watch Issuance...95 percent

SUMMARY...Strong to severe wind gusts and hail are expected to
remain a threat during the next several hours as the cluster of
storms continues southeastward. WW likely.

DISCUSSION...Recent radar imagery continues to show a small but
well-defined convective system moving southeastward across eastern
NE at about 35 to 40 kt. Nocturnal stabilization has made the
downstream airmass less favorable for surface-based convection (i.e.
SBCIN is less than -50 J/kg based on recent mesoanalysis). Even so,
the very moist nature of the airmass, evidenced by dewpoints in the
mid 70s and 100mb mean mixing ratios around 16 g per kg, and at
least moderately steep mid-level lapse rates result in enough
instability to maintain elevated convection. Moisture gradient
between the drier conditions of the middle MS Valley and more moist
conditions across the central Plains will provide a favored track
for the system. As such, the general expectation is for the system
to continue southeastward for the next several hours, eventually
reaching far northeast KS and far northwest MO. Strong to severe
wind gusts and isolated hail appear probable as this system
continues southeastward and a watch will be needed to cover this
persisting threat.

..Mosier/Edwards.. 07/19/2018

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

ATTN...WFO...EAX...OAX...TOP...GID...

LAT...LON   40039804 41069843 41729809 42099709 41289555 40019502
            39489671 40039804 

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SPC MD 1079

MD 1079 CONCERNING SEVERE THUNDERSTORM WATCH 281… FOR MUCH OF EASTERN NEBRASKA

MD 1079 Image


Mesoscale Discussion 1079
NWS Storm Prediction Center Norman OK
0921 PM CDT Wed Jul 18 2018

Areas affected...Much of eastern Nebraska

Concerning...Severe Thunderstorm Watch 281...

Valid 190221Z - 190415Z

The severe weather threat for Severe Thunderstorm Watch 281
continues.

SUMMARY...A few storms capable of hail and locally strong wind gusts
remain possible across eastern Nebraska. Isolated storms may
eventually affect northern Kansas, but a watch may not be needed.

DISCUSSION...Storms across NE has remained largely cellular this
evening owing to lengthening hodographs and sufficient low-level
SRH. 00Z soundings from the area indicate a marginally unstable
environment with relatively poor lapse rates aloft, yet ample
low-level moisture. Some increase in the southerly low-level jet
this evening may support a continued severe threat over far southern
NE and into northern KS, as capping remains minimal. However, it is
unclear whether a new watch will need to be issued at this time,
especially if storms remain isolated.

..Jewell.. 07/19/2018

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

ATTN...WFO...EAX...FSD...OAX...TOP...ICT...GID...LBF...

LAT...LON   39189903 41179936 41749933 42419898 42719855 42839805
            42819750 42739704 42449659 41919616 41139585 40629573
            39919595 39489620 39189672 39109739 38999810 39019849
            39189903 

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Heat Advisory issued July 13 at 3:43PM CDT until July 13 at 8:00PM CDT by NWS

…HEAT ADVISORY NOW IN EFFECT UNTIL 8 PM CDT THIS EVENING… * TEMPERATURE…Afternoon temperatures will be in the middle 90s to around 100 degrees. Combined with the humidity, it will feel more like 100 to 105 degrees. Additionally there may not be much relief overnight as lows only fall into the middle 70s. * IMPACTS…Exposure to the heat without a way to cool down will