Bryan, Thanks for pointing out the flaws in the system. Limitations of radar technology is not something I would have considered given my extremely limited knowledge of how the whole thing works. Your perspective is greatly appreciated!
It’s kind of a bummer that one of the largest areas in Colorado for migration is sort of in a black hole down there... The whole thing makes me think about sensitivities and specificities. Seems like the Birdcast info is decently specific, but the network definitely lacks sensitivity, particularly in our case. Much like medical testing, nothing beats the gold standard of getting your eyes directly on whatever it is you’re looking for. As you pointed out, the real value is going to be correlating weather data and birdcast info with observational reports. To that end, a quick romp around my “patch” here in SE Denver turned up a couple of odd-balls. Wayward loggerhead shrike, lesser yellowlegs, Wilson’s snipe, and Lincoln’s sparrows were the highlights and first records for the species at this park for me. Along with those, a group of black crowned night herons flying overhead and a continuing Western Grebe were also interesting. “Bad weather, good birds,”wins again. I’m sure there will be many other reports to the same effect over the next couple of days. Happy (social isolation appropriate) Birding! Steve Rash Denver Co. > On Apr 16, 2020, at 7:55 AM, Bryan Guarente <[email protected]> wrote: > > > Steven, > The interesting things that you are noting are dataset problems in SE CO. > The closest radar (what birdcast is based on) is probably Pueblo (but the > radar is along the El Paso/Pueblo county borders). The further away from a > radar you get, the higher up in the atmosphere you are and the less likely > you are to encounter birds since they like to fly about 1-1.5km above the > ground (if possible). By the time you reach that far out on a radar beam, > you are usually 4-6km off the ground, so you are missing the bulk of the > birds if there are any. The green dots on the birdcast map are where the > radars are, and you will see quite clearly that there aren't radars very > close to SE CO. > > I love the folks at Cornell and appreciate what they are trying to do on a > localized scale with the radar data. It is a great dataset for correlating > with local upticks in birds. It isn't, however, a large-scale indicator of > bird movement. They can only be reactive, not proactive to the weather > patterns. Getting a deeper look into forecasting is what I am trying to do. > I hope my forecasts can help in a different way than the birdcasts can. > > Thanks for the info. > Bryan > > Bryan Guarente > Meteorologist/Instructional Designer > UCAR/The COMET Program > Boulder, CO > > >> On Thu, Apr 16, 2020 at 7:31 AM Steven Rash <[email protected]> wrote: >> Bryan, >> >> The overnight Birdcast seems to agree with your prediction, though it looks >> like the bulk of the movement was full on northward. I bet there were some >> wayward flocks on the fringe that made it into the southeast corner as well. >> Cool to see the correlation between datasets! Thanks for your post. >> >> https://birdcast.info/live-migration-maps/ >> >> Steve Rash >> Denver Co. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Colorado Birds" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/cobirds/dba62e7e-edd8-4aa6-a41f-688c0835a493%40googlegroups.com. -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/4DA0CD82-6718-4FBC-8113-214B938A65AD%40gmail.com.
