SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0251 PM CDT Thu May 05 2022
Valid 052000Z - 061200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN
TEXAS ACROSS NORTHERN LOUISIANA AND INTO SOUTHERN ARKANSAS...
...SUMMARY...
The threat of scattered severe storms will persist through early
evening across parts of eastern Texas through the Mid-South.
Damaging winds, isolated tornadoes and large hail remain possible.
Primary changes at 20Z were to reduce severe probabilities behind
the cold front in Texas, and to expand the Slight Risk into Middle
TN, south-central KY and northern AL. Also removed the small Slight
Risk over eastern OK as the air mass continues to overturn with
numerous storms. Isolated hail remains possible over eastern OK.
For more information on the Ar/MS/TN area, see mesoscale discussions
661 and 662. And for the eastern OK area, mesoscale discussion 660.
..Jewell.. 05/05/2022
.PREV DISCUSSION... /ISSUED 1130 AM CDT Thu May 05 2022/
...Central and east TX to the Mid-South...
Water-vapor imagery this morning shows an intense mid-level
shortwave trough over the central/southern High Plains. The leading
edge of strong mid- to upper-level forcing for ascent is
overspreading central/eastern OK late this morning. As the
mid-level trough progresses east today/tonight, additional
thunderstorm activity will result in an extensive area of
thunderstorm clusters/bands from central TX northeast into the Mid
South/MS Valley. Extensive cloud cover will likely delay/partially
inhibit destabilization for parts of the Mid South. However, a
rejuvenation of storms is expected with damaging gusts the primary
threat with the stronger storms this afternoon/early evening.
Farther south ahead of a composite boundary over TX, a very moist
airmass sampled by the 12z Corpus Christi, TX raob showed a 17 g/kg
lowest 100 mb mean mixing ratio---supporting large buoyancy and
thunderstorm activity. Mean flow oriented largely parallel to the
boundary has and likely will continue to favor a linear band of
strong to severe thunderstorms. As this activity evolves, a mix of
linear convective clusters and perhaps an embedded supercell will
likely evolve into a QLCS across east TX moving into the Arklatex
this afternoon. A tornado/damaging gust hazard will probably
accompany any bows/surges in the squall line. A risk for a couple
of supercells or a severe storm cluster on the southern flank of the
evolving squall line will pose a hail/wind and perhaps tornado risk.
However, farther south, capping and weaker large-scale forcing for
ascent will limit storm coverage/intensity. A gradual weakening in
storm intensity is expected during the evening as storms move into
southeast TX/southern LA and parts of southern MS late.
...Ozark Plateau vicinity...
The aforementioned mid-level disturbance rounding the base of a
larger scale trough, will continue east across OK today. Cloud
breaks across eastern OK in combination to some modest diurnal
heating and cooling mid-level temperatures, will lead to moderate
destabilization by early afternoon. Ample mid- to high-level
flow/shear will support updraft organization and the propensity for
large hail growth with the stronger cores. Despite the presence of
rich low-level moisture over a small part of southern OK ahead of
the front (north of the northeast TX thunderstorm activity),
low-level shear is forecast to remain weak/modest, thereby limiting
the tornado risk.
Read more CHECK UPDATE ZOOM GRAPHIC
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