000
acus01 kwns 250059
swody1
Storm Prediction Center ac 250057
Day 1 convective outlook
National Weather Service Storm Prediction Center Norman OK
0757 PM CDT Friday may 24 2013
Valid 250100z - 251200z
..there is a slight risk of severe thunderstorms over a portion of the Central
High plains...
..extreme northestern Colorado...Northwestern Kansas into a portion of western and central Nebraska...
Isolated storms that developed over the High Plains early this
evening persist mainly across northwestern Kansas into southwestern Nebraska. These storms
will remain capable of producing isolated large hail and locally
strong to damaging wind gusts next few hours as they develop through
the moderately unstable environment. The lbf 00z radiosonde observation indicates 1800
j/kg MLCAPE and around 30 knots effective shear. The low level jet is
strengthening and updraft rotation will remain possible with a few
storms. A small window may exist for a tornado or two as 0-2 km
hodographs increase in size and before the boundary layer decouples.
Storms may eventually evolve into a cluster and propagate eastward
through southern/central Nebraska.
Later tonight additional storms may develop farther NE across northestern
Nebraska into southeastern South Dakota and northwestern Iowa within zone of isentropic lift and
Theta-E advection on nose of strengthening low level jet. This activity will
likely be elevated...but may pose at least a modest risk for hail.
For additional information reference sels mesoscale discussion 793.
..srn plains...
Isolated storms persist southward through the southern High Plains of southeastern Colorado
into eastern nm within a weak shear environment. Steep lapse rates...
moderate instability and inverted-v environments will support a
threat of isolated large hail and downburst winds next couple hours.
Activity is primarily diurnally driven and should begin a gradual
decrease with onset of nocturnal cooling.
Other multicell storms developing across western through central OK are
within a weak shear environment...but strong instability with MLCAPE
from 2500-3000 j/kg. Isolated damaging wind gusts and hail may occur
with the stronger storms...but activity should gradually diminish
later this evening with onset of nocturnal cooling.
.Dial.. 05/25/2013
Mesoscale Discussion
000
acus11 kwns 250054
sels mesoscale discussion
Storm Prediction Center mesoscale discussion 250054 cor
nez000-ksz000-coz000-250215-
Mesoscale discussion 0793
National Weather Service Storm Prediction Center Norman OK
0754 PM CDT Friday may 24 2013
Areas affected...SW Nebraska...eastern Colorado...western Kansas
Concerning...Severe Thunderstorm Watch 215...
Valid 250054z - 250215z
Corrected for web graphic
The severe weather threat for Severe Thunderstorm Watch 215
continues.
Summary...primary severe storm risk of large hail will persist from
northwest Kansas into SW Nebraska for the next few hours. An isolated tornado is
not out of the question in the somewhat moister environment across
SW Nebraska.
Discussion...supercells are ongoing this evening from extreme northwest Kansas
into SW Nebraska along the I-80 corridor...immediately east-NE of a dryline
and surface low in eastern Colorado. The convection is being supported by the
interaction of subtle speed maxima aloft with moderate warm sector
buoyancy /MLCAPE near 2000 j per kg/...in an environment with
effective bulk shear of 35-45 knots. Given the steep lapse rate
profiles and supercell structures...large hail will be the primary
severe storm threat. Additionally...there will be some risk for a
brief tornado across SW Nebraska in the next hour or two...primarily with
the cluster of storms near I-80 that resides in the zone of stronger
low-level shear and somewhat lower local heights. Otherwise...storm
interactions should lead to some upscale growth of a convective
cluster in Nebraska...and potentially some eastward expansion of the severe
threat per the recent addition of counties to the watch in the lbf
area.
Farther S...surface observations and visible satellite imagery
suggest that storm coverage will be substantially more limited S of
I-70 in Kansas. Low-level ascent is less focused in SW Kansas/southeast Colorado where
the primary dryline is only weakly convergent near the Kansas/Colorado
border...and along a separate confluence line farther east near ddc
that denotes the transition to a cooler/moister environment. The
00z ddc sounding revealed a relatively high level of free convection height and
substantial convective inhibition for 00z...thus new storm
development in the southern part of the watch looks questionable.
.Thompson/guyer.. 05/25/2013
..please see www.Spc.NOAA.Gov for graphic product...
Attention...WFO...Gid...lbf...ddc...gld...pub...bou...cys...
Latitude...Lon 38880002 37750009 37320031 37070097 37040202 37590213
38820208 39730244 40090340 40890365 41590330 41960259
41930114 41700058 41400030 39980007 38880002
