The Inclusion Area/Percent in the warning templates must still be set to 0, because while issuing warnings for GID, even the smallest portion of a county in the polygon was included in the warning, many times not seen until the warning was created and the list of counties showed up. Just a suggestion, maybe set the inclusion area and percent to something a little higher so unnecessary counties are not included in warnings.

-KP

at 2130 the OT Top detection did pop up on the cell to the SE of our area today. Bottom right in the two right windows. Have seen what looked like an OT on this for at least 30 mins. but it was rather ill-defined… can see why the OT had trouble with it. Has 99% POS and has for at least 30 mins. The POS has been more valuable with this storm, while the OT has not been as helpful as I expected today. It is however very helpful in keeping track of the most severe storms, which is of course one reason it was designed for.

DSatterfield

Taking a look at the boundary highlighted…it is moving south with showers developing further to the southwest. Will the interaction cause the convection to blow up? The CI product is not helpful as there is a thick cirrus shield overhead. This boundary is south of the main warm front where all the supercells are currently ongoing. Update to follow…

2209z…it looks like the outflow boundary is too far west to interact with echoes developing in Custer county. We will be looking for outflow boundaries from the supercells further north and see if we can get further development.

jca

OT top detection is good but at 2115Z there is a cell that seems base don VIS 1km to have an OT. The OT Algorithm has not detected it. Might be something to go back and look at why. Prob SVR is 99% on this cell and it is warned.

cell in question is bottom right on two left panels.

DSatterfield

The center of the vLAPS analysis domain (200 x 200 km) was placed over Ord, Nebraska.  By some luck, a tornadic supercell developed in the center of the domain (shown here).  Composite reflectivity, surface wind, surface vorticity, and 850 mb vorticity are included in the 4-panel shown here.

-G. Garfield

TOR issued based on radar @ 2130Z. WFO Hastings issued a TOR on the same storm @ 2110Z.

Update…a tornado was confirmed on the ground within our CWA right along the county border @ 2125Z.

jca

This loop shows over 3 volume scans the prob severe going from 66 to 94% at 21z, but as of 2115z there is still no warning issued, even though several storms around this one with similar characteristics are warned. And as of 2115z…the prob severe is 97%!

The WFO issued a severe thunderstorm warning at 2119z with a prob severe of 96%.

jca

NSSL WRF has some 2-3 hour temporal errors over WEST NB this afternoon. The reason seems to be slow heating due to a model forecast showing a thick cirrus shield over the area. There was a minor shield of cirrus but it moved east and vis satellite showed strong heating by late morning in the area. Convection developed well ahead of  the NSSL WRF forecast due this cirrus impacting the heating and thus the forecast going forward. A great example of using a close analysis of synthetic satellite imagery to adjust  and evaluate model output.

images below from 14 Z and 23Z 23Z on top. D. Satterfield from WBOC Salisbury,MD

The first image shows a CI of 58% prior to high cloud intrusion. The second image highlights the higher clouds moving over the developing CU in question with no CI.

jca

Looks like vigorous CI is just starting to take place in the southern portion of LBF.  Recent VIS imagery shows a deepening CU field with GOES-R CI rate of 72% as of 2030Z (see image).

This is the same area that the OUNWRF and and VLAPS show very vigorous storms – especially UH.