Week 3 Summary: 12-16 May 2008


  • Dave Hotz, NWS MRX
  • Dan Miller, NWS DLH
  • Dan Porter, NWS ABQ
  • Ron Przybylinski, NWS LSX

Week three of the 2008 EWP looked to be off to a dull start, weather wise. Fortunately, this wasn’t the case and we gained some good feedback from our participants. You are referred to the Daily Summaries for details of each day’s events, but a quick synopsis follows:

Monday (12 May): Training day. Not really any weather through the whole CONUS, and with anticipated SVR in the CASA/PAr domains, a good day to hit training for all the projects

Tuesday (13 May): Storms developed along a cold front draped along and to the E of the I-44 corridor. Had good PAR exercise (and even attempted PROBWARN with PAR data given Dan M. and Ron P.’s familiarity with WDSSII). Alas, only received a few pixels worth of radar data in the CASA domain as the cap held that far south.

Wednesday (14 May): Did some CASA/PAR playback cases earlier in the day and then ran a PROBWARN IOP for W and C TX with two teams. One team took the storms near and south of I-20, while the other team focused on storms developing in Mexico and moving into the Eagle Pass, TX area.

Thursday (15 May): Similar to Wed. – ran CASA playback and then an abbreviated PROBWARN IOP near Eagle Pass, TX again.

Weekly Debrief…


DH: High temporal res is a big plus, however, have to rearrange concept to adapt to continuity differences (“temporally noisy”).

RP: Much nicer to see storm structure evolution (updraft downdraft) much better on live case.

There was a tendency to jump the gun, since signature could be there and gone in minutes, versus 5 min volume scans.

RP/DP: Evolution is so fast, how do we shift to deal with this in a warning sense.

RP: PAR would really help with rapidly evolving QLCS tornadoes.

How do we deal with tornadoes that are there and gone before there would have been an 88D signature?

Might there be more false alarms now that we see more of these transient features?

DP: In ABQ, got a lot of 2-minutes F0, between volume scans. Would PAR cause a spike in warning frequency? And will warnings always be too late?

DM: Far ranges, still don’t solve the radar horizon and beam spreading problem.

DM: Next year, WFOs will be used to super-res data, and PAR may not match up and be less desirable?


Had no real-time events, so some discussion on case playback, adaptive scanning, QC.

RP: Need a 360° surveillance of three low-altitude elevation scans, but just 2.0°.

RP: Some of the sectors were missing portions of the storms. And the sectors changed a lot – not a lot of consistency.

DP: Did a good job when storms were moving into the network, but once inside network, it got inconsistent.

Jerry B: What if there wasn’t 88D data to supplement? RP still thinks we need the lower three 360°scans.

DP: Would be nice to have a 20-25 VCPs, let software choose, but user can override.

DH: Will we use it for a full network, or just to fill in gaps? If the former, need to look at all scans. What happens when you have 120 CASA radars? Need to look at a composite, not individual radars.

DP: Significant attenuation, and dealiasing problems on leading edge of storms.

DM: DQ has improved significantly from last year.

DP: Gives you greater confidence than seeing data on 88D.

DM: Doesn’t see this as a replacement to the 88D, but a supplement/value-added, gap filler below 88D. Radar horizon in one corner of his CWA is 12-14kft. E.g., had a lake-effect situation, 28”, all echo was below lowest elevation, and satellite blocked area with cirrus. Only got reports and webcams.

JB: Were RHIs helpful? Yes.

JB: Were 3DVAR winds useful? Yes.

DP: Some concern about DQ – were the wind fields correct? Didn’t know.

KM showed 5/7 data from last week, including 3DVAR. Forecasters reviewed this case this week.

RP: See great potential.

DP: Can’t use it for hail threat (doesn’t go high), but for wind features (TVS, boundaries, microbursts, etc).

JB: Were you overwhelmed with amount of data? No.

DP: Not amount of data, but annoyed by how sectors scans keep flipping around. But like the one-minute update.

DP: Would like to have a VAD profile.

DH: Precip estimates.

JB: These are dual-pol radars, but we didn’t show any of it.


Thursday 5/15 debriefing:

Eagle Pass real-time IOP summary. We started by looking at the ondemand hail tracks and SHAVE calls (turns out we didn’t know they were making the calls in real-time).

NWS polygons are a lot bigger than our threat areas.

DM: Default polygons are usually too narrow. The upstream (back) end of the default warngen polygon is a set length – not tagged to threat area size, and the back end is one time step in the future, and must be dragged back.

Contours of our warning grids would be nice, but keep the grids so that they can be sampled. Option to do both.

Need better display management of our warnings.

DM: Doesn’t like how hotkeys are moving away from keypad.

DP: Interesting to see what was going to happen with the outflow boundary.

Lot of earlier talk about having low prob large areas when individual threats were still less certain.

DM: How do we define that we are “doing better”. Is it warning size? Better service?

Travis: Note that back edge moves forward, but front edge does not due to current software limitations. We will reprocess the data and move the front edge.

DH: How much lead time is too much? Greg says that each user requires different lead time. KM: Allows us to cover a lot of bases (different users) that we’re not covering. DH: Prefer that the forecaster determines when the warning gets to the public via the tv station, rather than the tv station taking the data and when to “light up the county” based on probs and time of arrival.

TS: We will meet with non-met experts to get their opinions on this.

Good discussion about probwarn and how various users could benefit (or get confused) with the added information.

Probwarn Archive Case playback:

Noted differences in threat area location and size, motion vector, direction uncertainty, probability trends.

DM: What about editing the current threat grid instead of the contours? Greg asks, how do you set motion vectors for the grid points? TS: Could automate some of this with algs. To help maintain threat areas.

DH: Would be nice to update all three threats on one storm with same motion. Perhaps add the storm motion vector to the contour editor, instead of sliders.

DM: When you pick up and drag threat, record the movement and automatically calculate the motion vector based on that! Togglable, so that forecaster can override this.

Brad: Asks forecasters about how much time they are spending on storm interrogation doing it this way. DH: Less time.

DM: This week – less time, but if integrated into AWIPS2, and with more experience, would get better.

DM and RP were doing the D2D on one, and WDSSII on the other – two person team.

RP: two-person teams

DP: No, but should in ABQ. But in GFK, they did have one person keeping track of warnings, and one person on the meteorology (radar analysis and NSE). But sometimes also had a dedicated meso person.

Tornado probs had big difference between forecasters.

DM: His tornado threat area took into account RFD and new cycle locations.

Experiment logistics:

RP: Consider a sliding shift schedule. Greg tough to do with schedules.

DH: Would be nice to intermesh with EFP’s briefings. Could utilize their discussions as an update for rest of the day.

What about three experiments? Like the cross-pollination.

Was one week enough? Two weeks might be better (would have to deal with EO and WFO management).

Number of participants. Seems to be a good number. Any less, and there might not be enough diversity and change to interact.

DH: Thinks an even number is best – teams of two.

DM: Get stuff into AWIPS/2 as much as possible. Will save a lot of spin up time on training.

AWIPS2 may hinder what we can do.

DH: Appreciate the willingness to listen to different viewpoints.

Appreciate the opportunity.

RP: Mind has changed, see some potential. May not in current form, but something else down the line.

Kevin Manross (EWP Weekly Coordinator, 12-16 May)

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