Mesoscale Discussion 0253
NWS Storm Prediction Center Norman OK
0309 PM CDT Wed Apr 03 2019
Areas affected...Texas Panhandle/northwest Texas into western
Oklahoma
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 032009Z - 032215Z
Probability of Watch Issuance...80 percent
SUMMARY...Marginally severe hail and strong wind gusts appear
possible with intensifying thunderstorm development across the
northern Texas Panhandle late this afternoon. Stronger storm
development, including the risk for an isolated supercell or two,
still appears possible near the Childress vicinity, but perhaps not
until closer to 7 PM CDT.
DISCUSSION...Although the mid-level cold core of a short wave
impulse crossing the southern Rockies still lags to the west of the
High Plains, lower/mid tropospheric lapse rates have become very
steep to the north of a 50+ kt 500 mb jet streak which is forecast
to gradually propagate across the Texas South Plains, toward the Red
River Valley through early this evening. Beneath this regime, deep
boundary layer mixing continues, with enough instability to support
increasing high-based thunderstorm development across northeastern
New Mexico into the Texas Panhandle. This is to the west of an
increasingly better defined dryline now evolving across the Texas
Panhandle, southward into the Texas Big Bend region. To the
north/east of the dryline, large-scale ascent, generally associated
with warm advection has supported persistent weak mid-level
convective development, with increasing cloud cover inhibiting
boundary layer heating and destabilization across the eastern Texas
Panhandle into western Oklahoma.
Near and just ahead of the dryline, boundary layer moisture
(characterized by surface dew points increasing into the lower 50s)
appears to be contributing to mixed-layer CAPE in excess of 500
J/kg, with some further increase possible through late afternoon
with additional insolation. It appears possible that high-based
storms encountering this environment, near/north of the Interstate
40 corridor of the Texas Panhandle, could intensify during the next
few hours, accompanied by at least some risk for severe hail and
wind.
Southeast of Amarillo/east of Lubbock into the Childress area, it
appears that capping associated with warmer elevated mixed-layer air
may tend to inhibit the initiation of storms. However, most model
output remains suggestive that isolated storm development may occur
closer to the 23-00Z time frame, when forcing for ascent will become
enhanced by a strengthening southerly 850 mb jet. If/when this
occurs, the environment across this region appears most conducive to
severe storm development, with a sustained supercell or two
possible.
..Kerr/Grams.. 04/03/2019
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OUN...LUB...AMA...
LAT...LON 35780170 36130084 35309969 34299914 33609943 33510015
34000043 34680075 35780170
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