For today, my area of focus is in the DVN CWA. I began by looking at some of the satellite imagery and associated products, such as CI and OT detection. It’s still a bit too early for the OT product to be useful and the CI product is just now beginning to hone in on the developing CU field across the region. In the first image below, I’ve scalloped the region where the CU field has been evidently increasing in coverage and vertical growth. The CI product doesn’t show anything above the 40% range just yet but it still is a good way to bring attention to this area for possible initiation as conditions become increasingly favorable for development. There is a location just south of the area I’ve outlined that shows a 70% chance for CI so that’ll be something to watch as well.

In the next image (below), I loaded the CONUS LAPS theta-e analysis (image) along with wind and METARs/station plots (the 800×800 domain is not available for this region today). Again, the area of interest is across the northern border of the DVN CWA. Except for the bulls eyes that appear where there are seemingly bad obs being ingested (when toggling over to the dewpoint analysis, these locations are evident), this has been a good situational awareness tool as well as a good product to put together a mesoscale analysis.

Comparing the analysis above with the theta-e difference product below, much of the DVN CWA is under an area of convective instability. Unfortunately, the aforementioned scalloped area of interest in the northern half of the CWA is blacked out so I’ve had to infer and fill in where a lack of data exists. It would appear that a gradient exists right through this area, which lines up with all previously analyzed parameters and products hinting that this is the area to watch over the next 0-2 hours.

~Linda

Currently convection across the northern sections of the CWA is anticipated to slowly trend down as it chews through surface instability showing up in CAPE fields of the LAPS.  In addition Near Cast  models is showing best mid to low level instability  is moving north out of the CYS CWA and into the RIW CWA over the next few hours. This should further lend to a downward trend.  for convection across the area. Remaining storms of significance are anticipated to chew towards the east into Nebraska along a narrow and subtle boundary on visible satellite  and showing up in 19Z LAPs run on CAPE fields as an enhanced area.

Grant H.

I was checking out the NSSL-WRF Simulated Satellite Imagery compared to the actual IR Satellite and it verified pretty well.  You can see low clouds over parts of Iowa and Nebraska and the idea of the vertically taller clouds is there..just not exactly in the same location.  At this point I like the idea of the model.

So if I go with this model you can see below convection would initiate between 22-23Z over Central Iowa and S. Wisconsin bordering N. Illinois and then move East-Southeast.

This actually would be supported since the environment looks unstable that it is moving into.  You can see on the Nearcast GOES Vertical Theta E Diff Mid Low that the high instability is from Central Iowa to N. Illinois and it looks like a boundary is there as well.

So now we shall wait and see if this actually occurs. My watered down mesoscale discussion – Vollmar

For the storm observed in the earlier blog the MESH algorithm is kicking out between a half inch and an inch. The reports that came back almost immediately following this storm were very similar at around 7/8 inch.  In the past for a high plains environment hail algorithms would kick out hail of about double what occurred in reality. This newer algorithm seems to negate the old “factor of”  methodology or at least will force the forecaster to re-acclimate  to a new “factor of” or a new rule of thumb.

Grant H.

It appears that on some runs of the LAPs that it can certainly nail the dominate storms to a very specific area. This is different from yesterday where cells were very displaced from reality. What is standing out here about these storms in particular is that a cold pool is spreading out in CAPE field on the background. This storm is reported as having half inch hail which is  very close to warning criteria. Knowing that the cold pool is spreading out helps to form a feeling that the support for this cell is disappearing and it will probably weaken very soon, which can help to decide not to warn and keep FAR down. I’d also like to not that the CIMSS Prob of Severe model was close but not quite exceeding 50% percent which is one extra indicator for this storm  before this moment. little battles one by one.

We have overlaid the MRMS combined reflectivity here and the theta-e difference for the storms developing in eastern WY. The storms appear to be developing in a region of the highest instability for the region indicating they could intensify as they continue to develop. It also indicates that the instability axis is fairly narrow.

-JB

Initial impressions today indicate that the NearCast model is providing additional confidence to what the visible satellite imagery is indicating. In the above visible imagery there appears to be a nice surfaced-based CU field from eastern NEb into northwest KS and then extending into southeast WY. On the NearCast model there is a ribbon of highest instability along this axis of CU as well.

-JB