Visiting forecasters this week were George Phillips (SOO, WFO Topeka), Jon Hitchcock (Forecaster, WFO Buffalo), and Chris Sohl (Lead Forecaster, WFO Norman). In addition, Milovan Radmanovac from the Weather Service in Serbia also participated. John Ferree (OCWWS) was an observer. Other participants who supported testing included Angelyn Kolodziej, Kevin Scharfenberg, Travis Smith, Greg Stumpf, Jerry Brotzge, Dave Priegnitz, Kevin Manross, Pam Heinselman, Rick Hluchan, David Pepyne. Liz Quoetone and Kiel Ortega were Weekly Coordinators.

Weather during the week was predominately outside the Oklahoma Testbed. Forecasters spent the first half of each shift on training or simulations for Phased Array and CASA. Monday through Wednesday evening IOPs were Probabilistic Warning events generally associated with weather in the central and southern Plains. Thursday both teams did the Prob Warn exercise from Grand Forks. This was followed by the only live event to make it into the testbed. Storms reached the PAR network and were viewable (albeit at longer ranges) for a couple hours. Storms ultimately reached the CASA network with less than an hour remaining in the shift.

General observations:

Prob Warn

Participants got very comfortable with the technological end of this process such that by the end of the week, they were putting out multiple threat areas for the same storm and keeping track of things. Both groups used AWIPS to interrogate storms and WDSS II for assigning the actual threat area. This seemed like a good way to keep the technology from getting overwhelming, as well as involving both members of the team. Some discussion involved how the users would interpret these probabilities. The idea was that most would have a trigger point for various actions based on the probabilities. However, once the forecaster becomes aware of those trigger points, does this factor into the assigned probabilities (even though we are technically not suppose to consider any societal aspects of this).

Forecasters experimented with probabilities with one team issuing a 100% hail threat for 60minutes with no degradation. This was associated on a long-lived HP supercell and obviously confidence was high. The group did some wind threats but speculated that this could be much more complicated in squall line situations (which nature did not afford us during the live events).

CASA and PAR

Scientists captured more thorough findings from the group but in general, everyone found the temporal improvements to be beneficial. While the improved resolution was also a plus, it was felt that this was somewhat offset by the release of the Super Res products in the 88D. Some mentioned the sector scanning for CASA as not very useful. Participants talked about the small scale (time and space) features that you could see with each radar and the benefits of perhaps getting a warning out earlier, but also weighing this against the inclination to overwarn on features which are transient and not associated with severe weather. A definite learning curve.

The Friday wrap-up session was followed by two talks:

“December 19, 2004 Southern Lake Michigan Single Band” Jon Hitchcock, Buffalo NY

“Radar Network and Hail Suppression System in Serbia” Milovan Radmanovac, Serbia

Liz Quoetone (EWP Weekly Coordinator, 2-6 June)