Mesoscale Discussion 1605

Issued

Aug 26, 2021, 7:37 AM CDT (12:37 UTC)

Expired

Aug 26, 2021, 9:00 AM CDT

In force

83 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

The Des Moines radar (KDMX), 90 km from the middle of the area, began a volume at 12:39 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

780 
ACUS11 KWNS 261238
SWOMCD
SPC MCD 261237 
IAZ000-261400-

Mesoscale Discussion 1605
NWS Storm Prediction Center Norman OK
0737 AM CDT Thu Aug 26 2021

Areas affected...Portions of western/central IA

Concerning...Severe potential...Watch unlikely 

Valid 261237Z - 261400Z

Probability of Watch Issuance...20 percent

SUMMARY...An isolated hail/wind threat may persist with a cluster of
storms moving eastward this morning. Watch issuance appears unlikely
in the short term.

DISCUSSION...A small cluster of storms has persisted through the
early morning across eastern NE while fluctuating in intensity. This
cluster should continue into parts of western/central IA over the
next hour or two. The airmass downstream is not overly favorable at
the moment for this activity to maintain itself, as a fair amount of
convective inhibition is in place across IA per recent mesoanalysis
estimates. However, even modest diurnal heating of the already moist
low-level airmass may help erode the convective inhibition to some
degree. This cluster is on the southern extent of the stronger
mid-level westerlies present across the northern/central Plains.
Still, recent VWPs from KOAX show some veering/strengthening of the
flow with height into mid/upper levels, which may support storm
organization in the short term. A supercell embedded within the
cluster on its southern flank has recently shown evidence of a hail
core. Given the mainly linear nature of the ongoing storms, isolated
strong to damaging winds may occur as this cluster moves eastward
over the next hour or so. Occasional hail also appears possible with
the embedded supercell. Current expectations are for these storms to
eventually weaken across central IA later this morning, and watch
issuance in the short term appears unlikely.

..Gleason/Thompson.. 08/26/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DMX...FSD...OAX...

LAT...LON   42749571 42849460 42719315 41889305 41379322 41259400
            41399568 41689603 42279578 42749571

Mesoscale Discussions in Iowa, 2021Every mesoscale discussion in 2021

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.