ACUS01 KWNS 250546
SPC AC 250545
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1245 AM CDT Sun Aug 25 2019
Valid 251200Z - 261200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE CENTRAL
AND EASTERN DAKOTAS...
Severe thunderstorms are possible this afternoon and evening across
portions of the northern Great Plains. Hail and severe gusts are
the primary hazards with this activity.
A broad mid-level trough near the Canadian Rockies will amplify as
it moves east to the ND/Manitoba border by early Monday morning.
Concurrently, height falls accompanying the mid-level trough will
overspread the Dakotas during the period. A surface trough will
sharpen during the day as southerly low-level flow maintains a fetch
of 60s F surface dewpoints into the Dakotas. Diurnal heating and
convergence near the boundary will preferentially favor storm
development along the boundary by mid-late afternoon. Adequately
strong mid- to high-level westerly flow coupled with moderate
instability (1500-2500 J/kg MLCAPE) will support strong to severe
storms. A few supercells are possible with an associated hail/wind
risk in addition to episodically severe multicells. Storms will
likely weaken during the evening as the activity approaches the Red
River as a combination of increasing convective inhibition and
weakening instability lead to a lessening risk for severe in MN.
...Eastern OK and the western Ozark Plateau...
A couple of thunderstorm clusters are likely to be ongoing this
morning over northeast OK near the terminus of a weakening/veering
southern Plains' LLJ. A couple of strong to severe gusts are
possible with this activity during the morning as it moves
southeastward into western portions of the Ozark Plateau.
Considerable uncertainty remains whether storms will develop later
in the day along residual outflow draped across central-eastern OK.
Confidence is low at this time regarding a late-day scenario for
severe, but later outlooks will reassess whether this possibility
warrants associated severe probabilities.