SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0257 PM CDT Sun May 29 2022
Valid 292000Z - 301200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT FROM NORTHEAST NE INTO CENTRAL MN...
...SUMMARY...
Severe thunderstorm gusts of 60 to 85 mph, hail to near baseball
size, and a few tornadoes are possible this afternoon and tonight
from parts of Nebraska northeastward into southwestern and central
Minnesota.
Storms have developed across the central Rockies (see MCD 961), but
much of the warm sector across the Plains remains capped.
Observations and the latest runs from the HRRR suggest it may be
another hour or two before convection develops in this region.
However, an enhanced risk remains appropriate and in the correct
location with no adjustments necessary.
Expanded the thunder line to include northern Michigan ahead of the
elevated storms across eastern Wisconsin which continue east.
..Bentley.. 05/29/2022
.PREV DISCUSSION... /ISSUED 1124 AM CDT Sun May 29 2022/
...NE to MN this afternoon through tonight...
In the wake of a lead shortwave trough, a surface cold front has
progressed southward into southeast CO/northwest KS/central NE.
This boundary is expected to stall today, in response to renewed lee
cyclogenesis in the vicinity of southeast CO/western KS, downstream
from the deep midlevel trough moving eastward from the Great Basin.
The lee cyclogenesis will maintain strong southerly low-level flow
across KS/OK and northward transport of mid 60s boundary-layer
dewpoints into the stalling frontal zone across NE. Farther
northeast, the warm sector will be maintained today into MN, in the
wake of morning convection. Additional storm development will be
possible this afternoon along the stalled front and near the remnant
initial surface cyclone, from northwest MN southward into eastern
SD. Where storm development is more probable, moderate-strong
buoyancy is expected in pockets of stronger surface heating across
western MN. Deep-layer vertical shear will be sufficient for
supercells, though there are some weaknesses in forecast hodograph
structures across this area this afternoon/evening. Large hail,
damaging gusts, and a couple of tornadoes will be possible.
The more substantial severe threat should evolve this evening
starting across NE, and continue overnight across southeast SD,
northwest IA, and southwest MN. Two potential convective modes are
evident: 1) isolated supercell development this evening/early
tonight along the stalled front in the vicinity of northeast NE, and
2) cluster/supercell evolution of initially post-frontal convection
across CO/WY this afternoon into NE this evening. Any isolated
supercell development this evening will be focused along the stalled
front in NE, with the potential for very large hail (baseball size
or larger) and a few tornadoes. The ongoing convection over
northwest CO will likely spread eastward in the zone of ascent
preceding the primary shortwave trough over the Great Basin. Storms
in this zone will pose a marginal wind/hail threat this afternoon
across northern CO/southern WY, with storm intensification more
probable by late afternoon/evening as the convection/forcing for
ascent encounter richer moisture/larger buoyancy across
western/central NE (along and to the immediate cool side of the
front). There will be the potential for both upscale growth of
clusters and embedded supercells, with the potential to produce a
few tornadoes, very large hail, and swaths of 60-85 mph outflow
winds tonight.
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/SRH23C
