At the 1 PM briefing on June 3, group got together to discuss yesterdays activities.

MFR IOP: MESH was useful and seemed to be accurate in size relative to the reports given. -20C Z was helpful because many storms across the domain had high reflectivities but not much into the hail growth zone, but the deepest storms that led to the warnings showed up nicely on the -20C Z products.  MESH showed 1 inch at one point, leading to the issuance of the warning, which verified. Enough shear present for MESH to do a good job at size estimation….where normally weak sheared environments MESH used to overforecast (when it was cell based).  Would be interesting to find out if gridded MESH continues to overestimate hail size.  All tilts reflectivity was used to draw the warning polygon, MESH used to zero in on threat area.  One team also used VIL to find the deepest/most threatening storms, and for this event they found 35 VIL sufficient for 0.50 inch hail, greater values for potentially severe hail.

Interesting rotational signature with greater than 50 kts velocity difference at 12 kft MSL on the western end of the storm complex.  Signature was nearly stationary for 25 minutes, and corresponded to a peak in the MESH of just over an inch before dissipating.  Reflectivity deformed with the circulation as well.

LMA Thoughts from the IOP:

• Good event for training…to show what LMA can and can’t do given isolated, not widespread coverage of storms.
• Was able to track updraft cores in the LMA data.
• DC network had some problems yesterday, missing some storms.
• Impressed with how the LMA cores followed the reflectivity cores.
• Next step for LMA data is to get trends into SCAN
• LMA would be very valuable in radar-sparse areas or in blockage areas
• GLM for warning input was sufficient to find the significant storms. Also agreed that the most benefits would likely be in the WR
• ICahead of CC, CC before IC, or same time in growing storms: Good research topic to see which occurrence might lead to useful intensification information.
• Algorithms based on LMA data could be useful, like a TVS type thing, but big questions about how this might differ from SCAN type alerts and the algorithms it uses

Discussion moved towards data overload if/when 1 min volume scans become operational, in addition to new radar products and algorithms and other sources of data.  Will be a VERY big challenge trying to figure out which data are most important and how to effectively manage all the data.  We don’t really know what the impact of all that data will have on operations.

Liz Quoetone and Paul Schlatter (EWP Weekly Coordinators, 1-5 June 2009)