SUMMARY:

Week #9 of EWP2010 concluded the 2010 spring experiment, and wrapped up with continued MRMS and GOES-R experimentation.  The 2010 experiment ended with probably our most prolific severe weather outbreak in our four-year history with the MN-ND record tornado outbreak.  During this week, NSSL and the GOES-R program hosted the following National Weather Service participants:  Angela Lese (WFO Louisville, KY), Melissa Kreller (Southern Region HQ, Fort Worth, TX), Marcus Austin (WFO Tallahassee, FL), and Dave Sharp (Melbourne, FL).

REAL-TIME EVENT OVERVIEW:

14 June: “Practice” IOP for some severe storms over Oklahoma and Texas.

15 June: All-day IOP focusing on an Ohio Valley MCS wind event, with some isolated non-tornadic supercells ahead of the MCS.  Many experimental warnings were issued.

16 June: Early afternoon IOP over the DC domain netted only marginally severe storms.  Evening IOP focused on western SD, including a prolific nearly stationary multiple-tornado supercell near Dupree.

17 June: Record tornado outbreak for Minnesota and North Dakota.  We issued 230 experimental severe weather warnings and statements through a 6 hour IOP, a daily record for the EWP.

MRMS:

As was the case from the previous 3 weeks of EWP2010, the forecasters became increasingly more comfortable with the MRMS products as the week moved along.  As if carefully choreographed, the weather events for each successive day became increasingly more severe and widespread, to prepare our forecasters the the following day’s activities!  In general, the forecasters used the MRMS products to their extent by the final day of activities, finding them to be very useful.  However, we did find one forecaster who gravitated back to a comfort level of using more traditional techniques nearing the final few hours of the 17 June outbreak, when a cluster of tornadic supercells was affecting southern MN.

In addition, as seems to be the case each spring, the experimental infrastructure seems to finally come to a nearly bug-free condition in the final few days of the experiment.  The HWT AWIPS system had very few issues on the last few days of the week, although some of the experimental MRMS grids still took a little long to load up for the first time.  If we plan to use AWIPS1 for one more year, this is a top priority to find a solution – speed up the loading of these products.  One of the developer/researchers did happen to note that he was amazed at the complexity of the procedures that were used by some of the forecasters, with multiple 4-panel panes with image combinations, etc., and at how our visiting forecasters could keep up with that.

Some of the comments received during the end-of-week debriefing were echoed from previous week’s forecasters.  For example, it was again noted that the tracks products (hail and rotation) were very helpful in double-checking the orientation of the storm-based polygons, and also helped to fine tune the width of the polygons to cover narrower severe weather threats.  However, it was noted that in the final few hours of the MN-SD outbreak, because there was so much severe weather, some the polygons started getting “wide” again since there was not enough time to keep up with the widespread coverage of the severe storms.  Knowing this, we could consider this event a good archive practice case, one which could be performed by the forecasters at the end of the week once familiarity of the MRMS products is at its peak.

It was again noted that some of the MRMS products, such as the Height of the 50 dBZ over the -20 degree C altitude were very useful to provide a simple quick-look heads up as to which storms were worthy of closer inspection or warning.  These products are somewhat sparse grids, and only show the most severe storms (so not many at once).  Since they are from the MRMS grid, there is no need to explore each storm from each radar using all-tilts or 4-panels with height sampling, or have to choose the appropriate radar – the “answer” is right there on one simple rapidly-refreshing grid.

And again, comments were made regarding developing MRMS products to help with wind-based warnings, such as those which could exploit the LLSD Radial Shear computations for a Mid-Altitude Radial Convergence (MARC) signature detection.

Other comments included:  The “thickness” products, such as H50_Above_H253 should include negative values so that we can know when storms are approaching severe limits. since the grids are so sparse they are sometimes hard to see; MESH appears to do better than MESHb at low elevations, and the reverse at high elevations (NOTE:  The gridded-MESH does not do an elevation correction like the cell-based ORPG version – this needs to be fixed); 30-min tracks worked better for training storms.

GOES-R:

As with other weeks, the GOES-R products were not used nearly as much as the MRMS products, but then again that is somewhat by design.  A convective initiation product is more useful at the onset of storms, and many of our shifts had begun after CI.  The forecasters did not that although the Overshooting Tops and Thermal Couplet products were sparse, they usually happened on storms that were already obviously severe from the radar data.  They did give a little more confidence however, but they had a tendency to stop looking at the products during the heat of the warning events.

Other useful comments included:  The products are on very sparse grids, so larger icons and alerts would be useful; they wouldn’t mind that the CI product was more liberal in its detection with higher FAR, but adding probabilistic info might help parse the more important signatures; would like a good Western U.S. example where there is a lack of multi-radar coverage (but unfortunately, also a lack of severe storms); have earlier starting shifts to concentrate on the CI products.

The PGLM data exposure was mainly through the 24 May 2008 Oklahoma archive case.  A couple of forecasters noted that they would have to acquire more understanding of what the relative values mean to severe weather before becoming more comfortable with it.  They also hoped that in future EWPs, there could be more emphasis placed on events outside traditional Oklahoma tornadic storms.  Unfortunately, time did not permit us to make additional archive events, and there were only and handful of real-time events that coincided with our domains (and the networks being active).  In fact, we didn’t have a single Central Florida severe event to test.

There are more details on the GOES-R HWT Blog Weekly Summary.

OVERALL COMMENTS:

Several commented that a simple 20-min Articulate primer on each of the experiments would have been very useful to have prior to arriving in Norman.  In addition, a 20-min Articulate on existing ways to get the MRMS data (Google Earth KML, and On-Demand) should be developed as soon as possible, to continue to expand the word out on these very useful applications.  Also suggested that regional teleconference meetings and workshops would be a good way to get the spread the word.

The forecasters prefer that we “hand-hold” on the first day a little better.  Perhaps an archive case on the first day and then throw them into warnings.  Also, default procedures need to be developed to avoid having to set them up the first day, which takes a long time [NOTE:  This was also suggested last year, but as I’ve learned, forecasters are very unique on their procedures, combining the experimental data with their own, that I felt it was better served to allow the forecasters to build their own.  I will have to re-visit this decision for next year.]

There were comments about the fact that the products still took some time to initially load, and that there was a lot of maintenance required of the AWIPS system.  [NOTE:  A full-time HWT IT person could really help here!]

A LOOK AHEAD:

We are finished for the spring.  The next operation could occur as early as this fall.  Details will be announced as they arrive.

Greg Stumpf, EWP2010 Operations Coordinator