22Z OUNWRF forecasting storms to fire along outflow from current storms and consolidate severe threat across the southern zones by 7 PM.  It really starts to hit the hail threat across the southern zones by that time.

In the very near term, OUNWRF did a decent job getting the intensification of the Furnace and Harlan storms, taking the furnace storm southeast out of the CWA briefly, and weakening the Harlan storm completely.

Here is the current warning/radar situation…

Garmon/Skov

Just got -27c/15min in the CTC product in Brown County — just west of MPX CWFA. This corresponds well to a developing echo in central Brown County. Perhaps a sign of more severe weather shortly?

The 3DVAR products are showing an intensification with the line of storms north of Omaha.  Updraft strength has increased to around 20 m/s Washington and Burt Counties. MESH increased to 2.2 inches in southern Burt County.

Latest updraft strength up to 21 m/s over southeast Burt County.

UPDATE…3DVAR shows an increase in updraft strength with a strong increase in max divergence above 8 km in northern Harrison County. Maybe see an increase in hail size in the next 15 minutes.

Continuing to increase…to 27 m/s at 2250z.

TMT/SN

Looks like 3-4 inches of rain has fallen over the past several hours SE of the Twin Cities. With another inch or two possible from training storms…opted to go with a FFW.

Line of severe thunderstorms has developed over the southeast MPX CWA. Small circulations have developed along the southern half of the line, which may locally enhance wind gusts (>65 mph). MESH with this line has averaged around 1″, and we did get one severe report of quarter size hail. Updraft strength and upper divergence have been somewhat marginal, which verifies our thinking that this is probably more of a wind bag than a large hail producer.

Velocity image at 2222z:

Issued another SVR for the La Sueur County Storm. Did see some weakening in the 3dvar fields, but the last volume scan suggested a renewed updraft and increased storm top divergence. However, MESH has decreased so it is unclear if the storm is just reorganizing or if there is a diminishing trend going on. MRD/TY

Ping-pong ball size hail jusr reported from Wilsonville area in SW Furnace county.  MESH up to around 2 inches and we have increased the hail size in the warning to around 2 inches.

The 3DVAR shows updrafts increasing downstream of the main large dominant updraft at this time.

Garmon/Skov

Just got a report of half dollar sized hail. This corresponds well with the MESH which indicated max of 1.89. Issued another warning upstream now that the storm has taken on a little more supercell type characteristics. Did have a decent low level circ in Wabasha County, but experience today suggests that the storms are elevated in this area.MRD/TY

Again, missing the OUNWRF  :,(  The recent HRRR runs have kept updraft helicity values pretty low (<100 m2/s2) across the plains and upper midwest. The forecast vertical wind shear and CAPE across MN should be sufficient for supercells, yet the HRRR says “nyet”.

SNELSON/TMT

Updraft strength has increased with storms moving into Northwest Iowa. 3DVAR showed steady increase especially with the storm over Monona County IA. The 1 km Total Wind showed an increase to 50 knots with this storm.

Maximum divergence above 8 km has increased to near 17 /s at 2150z.

Tim/Steve