ProbWarn Software: Would like function for probabilities such that you can set an initial and a final probability to ramp up to at a certain time and maintain throughout the warning time.

Also, with a high number of warnings in close proximity need to be able to hide threat area contours that are not currently being worked on. Quite frequently will accidentally move or highlight wrong contour while updating a different one.

Kristin Kuhlman (PAR Cognizant Scientist)

Issuing first tornado warning for threat in Pott. Co. panhandle, with evidence of rising motion from helicopter and rotation (vel: 30 out, 15 in) and notch in reflectivity in both PAR and KTLX. Going with low probs now, but expect increase in chance based on environment and beginning evidence of storm motion to the right. Discussion of whether or not deterministic tornado warning would be issued at this point–for this day and in this environment would go with “No” at this time.

Also updating storm motion for hail grids. And updating larger threat area to account for single core that has developed in SE Cleveland Co, smaller area higher probs.

*Software: would like to be able to toggle reflectivity while viewing warning contours as top source

Kristin Kuhlman (PAR Cognizant Scientist)

Testing very low (0%) prob for storms initiating in so Cleveland Co. and moving into Pottawatomie. Using probwarn to communicate expectation of increase in prob (to 40%) in central Pott. Co. in ~45 min. Uncertainty in storm motion and speeds puts warning grid covering almost all of Pott. Co.

Storms continue to back-build along front making it difficult to maintain coverage of threat areas.

Within probwarn software, would like clicking on slider bar able to move # one at a time instead of jumping to a random #.

Kristin Kuhlman (PAR Cognizant Scientist)

Dan. M. would like a “preview” button to see his warning before issuing it. Also has decided to junk previous two warnings and issuing one larger warning with higher uncertainties in storm motion to account for back-building updrafts along the line.

TOA and TOD should have actual times (UTC) in legend instead of 15/30/45 min.

Fast scanning rates from PAR giving rapid updates of individual updrafts, can cause ‘threat’ area to be too small and end up having to move it around too much. New larger warning accounts for this.

Kristin Kuhlman (PAR Cognizant Scientist)

Dan M. and Ron. P. have decided to combine examining PAR data with ProbWarn operations. The PAR cut-out along I44 is causing some difficulty. Estimating storm motion in WG is also problematic as storms are moving NE and pulsing in strength and the front is slowly moving SE.

Currently they have 2 warnings going. The storm closest to PAR is decreasing in strength and instead of cancelling the warning they have decided to go with lower probs and shorter duration. The storm in SE Licoln Co continues to look strong and they have gone with higher probabilities for that warning

Kristin Kuhlman (PAR Cognizant Scientist)

Bill and Brian have been encouraged by Greg to check out the small azimuthal velocity couplet south of KDDC. There are several waves rolling up along the gust front. They’re considering a low probability tornado swath all along the line and including the bow. Wait, they’re actually dong it! This could be the biggest swath created in this experiment to date. They’ll consider a 20% probability. Brian entered 270deg at 35 kts and a high uncertainty since the line is just forming up.

Jim LaDue (EWP Weekly Coordinator, 5-9 May)

Cynthia and Craig are still following the lead supercell and the trailing storm which is bowing. Craig’s thinking they’ll have to extend the trailing threat area down the growing line. They’ll keep the hail probabilities at 100% for both storms. Their storm motions between the two teams vary by as much as 20deg.

Jim LaDue (EWP Weekly Coordinator, 5-9 May)

Bill and Brian are watching intense inflow into the storm and in fact, one chaser reported damaging inflow with power poles down and roof damage ahead of the lead supercell. But there is no substantial circulation at low-levels. The storm has an appearance of a big HP blob with occluding low-level mesos quickly surrounded by heavy rain, hail and probably cold air. However, they feel that it still deserves a 40% probability.

Jim LaDue (EWP Weekly Coordinator, 5-9 May)

Hail:

0035UTC: MESH is only showing 1.75″ in the lead storm. The trailing storm is coming up. The lead storm recently came in with softball report according to SHAVE. Cynthia and Craig went with 90% for the lead and 80% for the trailing storm.

Jim LaDue (EWP Weekly Coordinator, 5-9 May)

New updraft is going up after the last occlusion.

Bill and Brian are considering going higher TOR probs with a new update. They centered the ellispse in the notch and are going with storm motion 290 23, Cynthia’s going 295 20. TOR probabilities are going higher – 80% dropping to 70% in 20 min.

Jim LaDue (EWP Weekly Coordinator, 5-9 May)