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

Very strong storms over Butler county over the last 45 minutes. Have had several reports of hail, most recently under the most intense storm of the day east of Brainard. Suprisingly, the spotter report was only nickel size hail at 2145 UTC. 2142 UTC MESH has showed as high as 2.4 inches in this area. The 2145 UTC 3DVAR composite updraft maximum and max divergence aloft at this location were also high, 23 m/s and  18 s-1, respectively. Not seeing much supercell development or behavior (mesocyclone, right turning or splitting). Updraft helicity has been low. Better vertical wind shear remains to the north over MN. Will continue to watch.

SNELSON/TMT

Mass continuity is still something we can believe in with 3DVAR data. The top right panel shows max divergence above 8km and bottom right panel shows composite updraft maximum. Saw both of these fields increase from 2050 to 2055 UTC. Was waiting to see if MESH or reflectivity would also increase in the subsequent 30 minutes, but as of 2125 UTC, have not seen any sign of this. MESH and storm reports have only yielded hail up to 1.5 inches.

SNELSON/TMT

Went with a SVR for the western storm in Goodhue Co. 3dvar data shows strong updraft close to 17 ms^-1 and updraft helicity close to 150 ms^-2. 3dvar 1km wind also shows 31m/s inflow into the storm. Suspect this developed right on the boundary and may be elevated but will need to watch for a low level circ developing given the proximity to the boundary. MRD/TY