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acus01 kwns 220443
swody1
Storm Prediction Center ac 220441
Day 1 convective outlook
National Weather Service Storm Prediction Center Norman OK
1141 PM CDT sun Apr 21 2019
Valid 221200z - 231200z
..there is a slight risk of severe thunderstorms from southeast nm
across northwest Texas and into far southwest OK...
...
Scattered severe thunderstorms capable of mainly hail and damaging
winds are possible from southeast New Mexico across the South Plains
and into parts of northwest Texas and southwest Oklahoma from late
afternoon Monday through evening. Isolated strong to severe storms
are also possible across parts of southern Wisconsin, eastern Iowa,
and northern Illinois. A weak, brief tornado cannot be ruled out in
either area.
...
An upper low will drop south from Arizona into northwest Mexico with a
leading shortwave disturbance moving out of northern Mexico across
West Texas. At the surface, a stalling front will stretch roughly from
southeast nm into central OK by 00z, with winds veering to easterly
across the High Plains. Mid to upper level southwesterly winds will
increase to an average of 40-70 kt respectively, enhancing the
potential for scattered severe storms.
To the north, a shortwave trough will move into the upper MS valley
during the afternoon, with a surface low moving from Iowa into Michigan.
Southerly winds will increase ahead of this low, enhancing low-level
shear, with the low track becoming a favorable corridor for isolated
severe storms.
..southeast nm...South Plains...southwest OK...
scattered storms are expected to form around 21z from central and
southeast nm into parts of west TX, where heating is strongest south
of the front. Hail is possible with the nm cells, as well as into
the South Plains. A brief tornado cannot be ruled out near peak
heating, near the boundary, and before cells grow upscale into a
possible mesoscale convective system. The greatest potential for damaging winds will likely
be along the boundary, extending into northwest TX, as storms move
along it, aided by strong east/northeast surface winds just north of
the boundary. A few storms may remain strong to severe into far
southwest OK, before the air mass overturns with more widespread
precipitation.
..eastern Iowa...Northern Illinois...southern WI...
upstream heating of a 50s dewpoint air mass and increasing southerly
winds ahead of the surface low will result in an axis of around 1000
j/kg MLCAPE by afternoon across IA/IL/WI. Forecast soundings show
some capping around 700 mb, but lift near the low track is expected
to support thunderstorm development, which will be centered over the
tri-state area. While winds in the mid and upper levels will not be
particularly strong (short hodographs), low-level veering of the
winds with height may support rotating storms with marginal hail,
wind, or a brief tornado (especially over WI where LCLs will be
lower).
.Jewell/karstens.. 04/22/2019
$$
Mesoscale Discussion
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acus11 kwns 220015
sels mesoscale discussion
Storm Prediction Center mesoscale discussion 220015
ksz000-nez000-220145-
Mesoscale discussion 0418
National Weather Service Storm Prediction Center Norman OK
0715 PM CDT sun Apr 21 2019
Areas affected...parts of north central Kansas
Concerning...severe potential...watch unlikely
Valid 220015z - 220145z
Probability of watch issuance...5 percent
Summary...thunderstorm activity capable of producing small hail and
a few strong wind gusts may persist, and possibly increase some, for
a period this evening. However, overall, the threat still appears
marginal enough that a severe weather watch will not be needed.
Discussion...ongoing small, but sustained cluster of thunderstorms
has accelerated some while advancing east-northeastward during the
past couple of hours, from near 20 to around 30 kt. Activity has
been mostly Post-cold frontal, aided by mid-level cooling and
sufficient boundary layer moisture to contribute to cape locally up
to around 1000-1500 j/kg. Deep layer wind fields and shear are
mostly modest to weak, but initially steep lower/mid tropospheric
lapse rates have been sufficient to support mainly small hail and a
few strong wind gusts.
It remains unclear how much longer this activity will maintain
strength as it spreads near/to the south and east of Hill City. It
seems possible that it may weaken as the cold front overtakes the
dryline and supports the initiation of new thunderstorm activity
downstream, around the Hays, Russell, Smith Center and Beloit
vicinities. It is possible that shear associated with strengthening
southerly 850 mb flow across this region could aid organization of
consolidating new development. But any associated severe wind
threat probably will be limited by the onset of boundary layer
cooling, which likely will result in an increasingly marginal
thermodynamic environment for vigorous convection.
.Kerr/Hart.. 04/22/2019
..please see www.Spc.NOAA.Gov for graphic product...
Attention...WFO...top...ict...Gid...ddc...gld...
Latitude...Lon 39949884 40019749 39509668 38279797 38069948 38480001
39429953 39949884
