Space vision

Some cool voyages to space occurred in the last week or so. The Cygnus spacecraft launched and after a bit of trouble docked with the ISS. A major milestone on the second flight for this company. SpaceX launched a new and improved Falcon9. They redesigned the engine structure on the 1st stage, built the second stage to refire to put satellites into higher orbits, modified the first stage to refire to control re-entry, and to fire again to slow the vehicle down for splashdown - what will eventually become a soft landing on launchpad!  The Russian proton rocket came roaring back to life after a failed flight previously.

Get in, Get Down, Cover Up!

Summary - Remember to shelter in place. Put as many walls between you and the tornado as possible. Get in, Get Down, Cover Up!

Verification continued

Yesterday I showed the full period (roughly a day 1 convective outlook) of the SSEO. Since we will test the ensemble at finer time scales, down to 3 hour periods, here are the three 3hr periods under consideration.
18-21 UTC

The figures presented here should be used with caution. The models do not always produce reliable or skillful forecasts of the initiation or evolution of convection or convective mode. Thus using them as I did before depends crucially on being good enough in the time period under consideration to provide useful but not specific guidance.

This first thing you may notice is how circular all the probabilities look due to the use of a gaussian smoother. Thus there are both very few reports and model simulated reports in these areas. There is very little overlap between reports and model reports.
21-00 UTC

In this second period, model reports increase dramatically for some members. The amount of overlap increases for NSSL-WRF, NMMB, and 3/4 of the HRW members. Not bad. I would hope that the members can capture some of the severe weather scenario that played out, including getting close to the proper location. NSSL-WRF does well in this period in SW OK as do the HRW-NMMs. If you look to NE MO then those members plus an HRW-ARW member cover that maximum pretty closely.
00-03 UTC

In the 3rd period, the ARW's, NSSL-WRF, and NMMB and HRW-NMM all contribute (glancing blow for some of them) in some way to the maxima in SW OK. The same holds for MO.

For this case at least, the models appear to be able to simulate at least 3 hour probabilities of total severe weather. As I have indicated elsewhere, the use of UH to match against all severe reports appears, again for this case, justified. Such will be one of my foci for the upcoming Hazardous Weather Testbed Spring Forecasting Experiment as part of the Experimental Forecast Program. Testing this out for a bunch of cases this year, and extending it back in time will be a goal of mine moving forward.

Verification issues: severe wx and fronts

I have been computing total severe probabilities from the SSEO and the event on the 17th offered a nice opportunity to do "verification". The idea is to use object based Hourly Maximum Updraft Helicity and treat local maxima as storm reports. This method allows us to extract information from the 4km pseudo convection allowing ensemble in a way that is comparable to storm reports (at least at the level of the grid used for verification, wind reports are scrutinized for speed).

Here is the verification, and of course this is all experimental: