Hey COBirders, I have been a little out of the ornithological and meteorological loops recently, but someone egged me on to get back in with this upcoming storm. Seriously, thanks for egging me on. You know who you are.
*6am April 13th (Thursday morning; from the past; Green circle is Longmont for reference)* https://earth.nullschool.net/#2023/04/13/1200Z/wind/isobaric/850hPa/orthographic=-105.12,40.19,2811/loc=-105.120,40.191 On that map above, you can see the beginnings of stronger southwest winds from the Southwest US toward CO. Note the big river of stronger winds from Texas is NOT making its way into CO. This pattern only intensifies as the day goes on and the mountains heat up... *2pm April 13th (Thursday afternoon; from the past**; Green circle is Longmont for reference**)* https://earth.nullschool.net/#2023/04/13/2000Z/wind/isobaric/850hPa/orthographic=-105.12,40.19,2811/loc=-105.120,40.191 The pattern intensifies, and we stay connected to the SW U.S., not Texas like can bring us the more "eastern" birds. We are however set up to see more Southwest specialties (Black-throated Sparrow and Black Phoebe, for instance (and I am showing my northern CO bias)). The main river of strongest winds remains well to our east. With the forecast frontal passage and spring storm coming tomorrow (Apr 14th), some people have speculated that we will see some good spring storm birds. I think we aren't as poised as we can be for a big "fallout" or "put down" in this case. Showing the same map again but with a different green circle location: https://earth.nullschool.net/#2023/04/13/2000Z/wind/isobaric/850hPa/orthographic=-105.12,40.19,2811/loc=-107.828,43.709 That green circle is the beginnings of the cold front that will pass through us during the overnight hours (Apr 13th into 14th). *10pm April 13th (Thursday night; maybe in the past depending on when you read this)* https://earth.nullschool.net/#2023/04/14/0400Z/wind/isobaric/850hPa/orthographic=-105.12,40.19,2811/loc=-105.175,42.271 Front is still up in Wyoming, and the leading edge is indicated by the green circle where the winds are changing to a more northerly direction. And most of CO is shutting down it's SW connection and getting ready for the northerly connection. *6am April 14th (Friday morning; green circle is Longmont)* https://earth.nullschool.net/#2023/04/14/1200Z/wind/isobaric/850hPa/orthographic=-105.12,40.19,2811/loc=-105.120,40.191 The front is now through me in Longmont and is almost to Pueblo. Frontal passages can happen really fast through the state as seen here. So now the northern 2/3 of the state is cut off from migrants, but may have had some southwestern migrants into the state that will now be somewhat desperate for food in the morning. I don't see any good concentration points anywhere in the state. *2pm April 14th (Friday afternoon; green circle is leading edge of the front)* https://earth.nullschool.net/#2023/04/14/2000Z/wind/isobaric/850hPa/orthographic=-107.28,39.51,2811/loc=-104.368,37.595 The connection to the Southwest U.S. that was present on Thursday, is now no more anywhere in the state. *10pm April 14th (Friday night; green circle is leading edge of stalling front now in NM)* https://earth.nullschool.net/#2023/04/15/0400Z/wind/isobaric/850hPa/orthographic=-107.28,39.51,2811/loc=-101.708,35.881 And now at 10pm, there are no good chances of spring migrants adding to the mix during Friday overnight. This also means that the birds that showed up on Thursday night will likely still be around for the weekend birding rush. So in summary, we will get migrants, they will likely have a southwestern flavor to them, not an eastern flavor. There aren't any particularly good locations for bird convergence during this storm, but there are likely birds out there that will be desperate for food tomorrow depending on their food needs (think like Dave Leatherman) and will be likely easier to find and might end up at your feeders or a local insect hotspot. As usual, all data is good data, so let us know what happens on COBirds or the CFO facebook group. Hope this email gets you thinking and looking. I wish you good birding wherever that may be tomorrow. May the migrants come to you. Bryan Bryan Guarente Meteorologist/Instructional Designer UCAR/The COMET Program Boulder, CO -- -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to cobirds@googlegroups.com For more options, visit this group at http://groups.google.com/group/cobirds?hl=en?hl=en * All posts should be signed with the poster's full name and city. Include bird species and location in the subject line when appropriate * Join Colorado Field Ornithologists https://cobirds.org/CFO/Membership/ --- 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 cobirds+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/CAENnWHu1pTzRr0Tbg2my7ss6kW6VuMi7_UM4R39rWoy5%2BxeA3w%40mail.gmail.com.