David, and others,
Below is an excerpt from the NFC-L List Information and Rules page (http://www.northeastbirding.com/NFC_RULES). RADAR discussions, as they pertain to bird migration, are perfectly acceptable (as are limited-sized attachments - I think under 900 kb is safest; Lyris limits at about 950 kb, including message headers). Please do feel free to continue! NFC-L is an email list (the List) focused on the discussion of the night flight calls of migratory birds. The primary purpose of the List is to provide an effective electronic forum for experienced birders to discuss the identification of night flight calls of migratory birds, exchange ideas about recording equipment design and setup, disseminate information about active or predicted night flights in your area, and to better understand weather and RADAR data as they relate to patterns of nocturnal bird migration. Initially, attachments containing limited-sized sound files, photographs, frame-grabs, or other documents to help further the discussion and shared knowledge of nocturnal bird migration will be acceptable and are encouraged. Be advised that attachments can also serve as a mode for spreading infectious computer viruses. Use caution when opening any attachment. Thanks! Sincerely, Chris T-H -- Chris Tessaglia-Hymes Listowner, NFC-L Ithaca, New York [email protected] <http://www.mail-archive.com/[email protected]/maillist.html> NFC-L - Archives <http://www.northeastbirding.com/NFC_WELCOME> NFC-L - Welcome and Basics <http://www.northeastbirding.com/NFC_RULES> NFC-L - Rules and Information <http://www.northeastbirding.com/NFC-L_SubscribeConfigurationLeave.htm> NFC-L - Subscribe, Configuration and Leave From: [email protected] [mailto:[email protected]] On Behalf Of David La Puma Sent: Tuesday, May 03, 2011 1:10 PM To: NFC-L Subject: Re: [nfc-l] odd NEXRAD pattern Bryan et al- Thanks for the links! Has anyone seen this yet? http://soar.ou.edu <http://soar.ou.edu/> Jeff Buler at U Del is doing some great radar ornithology work and passed this link onto me. It's great to see the atmospheric folks getting into the biological side of things; what started out as just "noise" has turned into something much more interesting, I think. Anyway, the SOAR website is great for screening nights for migration and looking at things at the national scale (although you can zoom in locally too!). Give it a whirl- and with that, I will refrain from further hijacking of the NFC list with radar posts ;) Cheers David On Tue, May 3, 2011 at 12:30 PM, Bryan Guarente <[email protected]> wrote: David and others, You were asking about where to get archived soundings/wind data. There is a lovely archive at the University of Wyoming's website here: http://weather.uwyo.edu/upperair/sounding.html and equivalent archived upper-air maps here: http://weather.uwyo.edu/upperair/uamap.html and real-time profiler data here (only found over the Great Plains): http://weather.uwyo.edu/upperair/profiler/ >From there you can select an image type (stuve or skew-t is likely preferred, but hodographs are available as well if that is what you know how to read). Then select the date and time (remember it is all in UTC) and then a location. There are soundings here for all over the globe, so this isn't a bad site to have on hand for investigating other sites outside the US. You don't need to know the number of the sounding station, you can just click on it on the map. If you select stuve or skew-t the winds will be up the right side and those correspond to the heights and pressures listed on the left side of the chart. Here are the soundings from Omaha, NE and North Platte, NE for the closest times to Bill's original observations. Note the significant difference in winds in the low levels. Omaha shows a strong north-northwest wind, while North Platte shows a highly variable wind direction and light winds at low levels. This suggests exactly what David and others have theorized about. Omaha: http://tinyurl.com/3nbtoyv North Platte: http://tinyurl.com/3gwtu48 Another way to look at this, although not observations is to look at the streamlines from recent model output. I plot streamlines on my website here: http://homes.comet.ucar.edu/~guarente/birdweather/stream.htm <http://homes.comet.ucar.edu/%7Eguarente/birdweather/stream.htm> I unfortunately have not set up an archive yet for my site due to space limitations, but I might be able to rerun that date to show the effects seen in the soundings and on radar if anyone wants to see it. This kind of pattern often happens with the passage of weak fronts. The winds start to either turn around quickly due to local effects or the winds are so weak behind the front that migration can easily occur even in the face of a northwest wind albeit light. (opinion) I personally think that most bird migration discussions focus a lot on long distance migration nights more than they focus on those localized events that can sweep out all the recent migrants from a small area or those that bring in a small push of birds very close behind a front despite the winds being out of the wrong direction. For this reason, I am contemplating adding winds speeds to my streamlines maps, but it is currently unclear to me the best way to visualize this from model data because the winds are so variable that the map gets way too complicated for most individuals to read. I might do some averaging to get a broader look at the winds, but there are some hits taken by doing that. We'll see what I can pull off sometime with my extra time. Bryan Guarente Instructional Designer The COMET Program University Corporation for Atmospheric Research Boulder, CO -- NFC-L List Info: <http://www.northeastbirding.com/NFC_WELCOME> Welcome and Basics <http://www.northeastbirding.com/NFC_RULES> Rules and Information <http://www.northeastbirding.com/NFC-L_SubscribeConfigurationLeave.htm> Subscribe, Configuration and Leave Archives: <http://www.mail-archive.com/[email protected]/maillist.html> The Mail Archive <http://www.surfbirds.com/birdingmail/Group/NFC-L> Surfbirds <http://birdingonthe.net/mailinglists/NFCL.html> BirdingOnThe.Net Please submit your observations to eBird <http://ebird.org/content/ebird/> ! -- -- NFC-L List Info: <http://www.northeastbirding.com/NFC_WELCOME> Welcome and Basics <http://www.northeastbirding.com/NFC_RULES> Rules and Information <http://www.northeastbirding.com/NFC-L_SubscribeConfigurationLeave.htm> Subscribe, Configuration and Leave Archives: <http://www.mail-archive.com/[email protected]/maillist.html> The Mail Archive <http://www.surfbirds.com/birdingmail/Group/NFC-L> Surfbirds <http://birdingonthe.net/mailinglists/NFCL.html> BirdingOnThe.Net Please submit your observations to eBird <http://ebird.org/content/ebird/> ! -- -- NFC-L List Info: http://www.NortheastBirding.com/NFC_WELCOME http://www.NortheastBirding.com/NFC_RULES http://www.NortheastBirding.com/NFC-L_SubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/NFC-L 3) http://birdingonthe.net/mailinglists/NFCL.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
