Have a new CI ping, 70-80% in Fall River county.

Looking at the Nearcast model, have a little peak that bends down to that point in the county.  Will have to watch to see if we get new development there.  It is a little drier down there, so wonder if a storm that forms here may have better mix down of winds.

UPDATE:  That cell did not develop, however we have another high CI signal later, here:

After warning the cell multiple times, we finally started to get reports to verify our thinking.

We had 1″ hail reports at 3:25p and 4:15p and a 1.25″ report at 3:28p, all in Pennington Co.

Our first warning was issued at 3:02p based on ProbSevere, a few lightning jumps and DVIL with little help from Convective Outlook (only general risk).

-BT and Charley

Reports starting to come in now, but cell is starting to trend down.  New cells had been creeping westward, with me having to go farther west slightly for each new warning.  This is the first time the cell was maintaining in the middle of my last warning.  Thus think the cell is beginning to cut itself off.  Highest dbZ is only in the 25-30 kft range.  Have not seen any further lightning jumps.

A few of us did interviews with NASA TV concerning what we were doing at the HWT, the use of GOES-R products, how it will change things, and how forecasters will train and ultimately use them in forecast and warning operations.  They may show up on social media and NASA TV at some point in the future.  I compared GOES-R to going to HD or UltraHD (4K) in TVs.  MrSnow

CI percentages are increasing across western MN late this afternoon. MLCAPE values in this area ahead of a cold front have increased into the 1000 to 1500 J/kg range… with deep layer shear in the 40 to 50 kt range. This may be the first signs of a possible line of strong to severe storms developing over the course of the next couple of hours.

-Wacha

Living vicariously through Minneapolis and Aberdeen…

The 2130Z Visible with the overshooting top and CI overlaid shows a few interesting things. There is currently an overshooting top with the strong/severe convection over Grant County, SD. Current IR Imagery shows a core of -58C surrounded by a broad downwind anvil of approximately -53C. There is a tighter gradient of cloud temps on the upwind side of the anvil, with temperatures on the edge dropping quickly into the upper -40s C.

Also, the CI values began to highlight an area east of the ongoing strong convection with two scans showing greater than 90% chance of convective initiation. On the corresponding 2130Z radar image out of MPX, only a weak shower is shown.

Fast forward to the

Flash Forward to 2207Z, there has been no further development with the cell that showed promise in the CI in Pope County, MN

-Shasta

Storms have been forming along the same area for awhile, likely leading to flash flooding.  Linked the radar to the topo maps to see why.  It’s forming right along the Black Hills with a 3 kft height change over the area.

Cell continues to look like it is dropping some kind of hail.  Actually may be stronger at this point.  Did have a stronger sigma lightning jump, 5 sigma.  Dual pol data HC showing Hail-rain down to the 0.5 degree tilt, and that is fairly close to the radar.  Have 50 dbZ up to 32 kft.  DVIL higher than before as well.

J

Lighting products even thunderstorm alert not picking up on cell that had a report of wind damage.

One minute lightning showing strikes but not sufficient enough for products on the first frame

CIMSS product showing low prob of severe.

Noting that with the short line segments, somewhat marginal conditions for severe weather, with wind being the highest threat, that the lightning products and the CIMSS prob severe product has not helped us pick out the storms with highest probability of producing at least close to severe wind. We were watching closely the cell that we eventually warned on over Worcester Co. and decided to issue when we received a report of trees/limbs down by law enforcement.

Signal for higher DVIL with the northern cell.  ProbSevere still indicating severe and we have evidence that it can still be a good product when watching a discrete cell.

Lightning data still seem suspect, with low sigma for jumps, but very low CG data as well.  Wonder if not as good of a network in this area?