COBirders, What a great way to kick these forecasts off for the season! It may be too early to wish you a happy Labor Day, but there is a good possibility of a migratory gift on Monday September 7th. You may think I have my days wrong and that the gift should be coming on Tuesday with the snow (!), but the winds are forecast to be better on Monday than they are on Tuesday for bird migration into the Front Range. Tuesday may still be a good day to get out (Go Birding in Bad Weather), but Monday looks better for the winds to concentrate birds into our Front Range/Eastern Slope area (Go Birding in the Right Weather). Sorry West Slope folks.
COVID disclaimer: don't put yourself or others at risk. Because of the way this pattern is, there is no one place that looks best aside from "along the Front Range", so your chances could be just as good in your Front Range backyard as it will be multiple hours from your house. Let's get down to it... Monday Morning (6am): https://earth.nullschool.net/#2020/09/07/1200Z/wind/isobaric/850hPa/orthographic=-107.79,50.66,1205/loc=-105,40 The winds at 850mb (near-surface in the Front Range) are originating from WAY north and will have been doing the same for a day and a half; they just weren't terminating in CO. The nice turning from the north to an east wind into the Front Range is starting to look pretty nice for anywhere along the Front Range. But wait... it gets better. Monday Midday (12pm): https://earth.nullschool.net/#2020/09/07/1800Z/wind/isobaric/850hPa/orthographic=-107.79,50.66,1205/loc=-105,40 The winds now at 850mb are still from WAY up north and turn more into the Front Range region (including WY) condensing a broader swath of the winds into a smaller area of convergence. This can only mean more concentrations of birds over the daylight hours. The best bets are from Cheyenne through CO Springs. Monday Evening (6pm): https://earth.nullschool.net/#2020/09/08/0000Z/wind/isobaric/850hPa/orthographic=-107.79,50.66,1205/loc=-105,40 And the winds continue with convergence that just keeps on giving. An even broader area of winds condensing into a smaller area. Now it is Cheyenne through Denver that looks better. This is now 12 hours or more (depending on how you count it) of convergence into the Front Range with a very long swath from the north. This is what you should be on the lookout for when trying to make your own migration forecasts. The convergence could be better into one location, but at least this way everyone gets the chance at good birds. If you live in Denver or the close vicinity, wait for it though... (Tuesday Midnight) https://earth.nullschool.net/#2020/09/08/0600Z/wind/isobaric/850hPa/orthographic=-107.79,50.66,1205/loc=-105.080,40.187 It gets better, but it is questionable how many birds will want to be moving at this time since the rain/snow should be starting around this time. And then after this time, it starts to broaden in terms of convergence into the Front Range area and we lose the nice wind direction for migrants to even enter into CO from great distances away. Not to be too predictive, but it seems like a really nice time for extralimital shorebirds (Curlew Sandpiper? More Buff-Breasted Sandpipers, but up against the mountains?) and could be good for the earlier jaegers (Long-tailed). Warbler and vireo turnover should be good. Ducks could be turning over too. The summer residents will start making more of their way south out of CO. But let's not be too prescriptive, just go out birding as the gift will keep on giving. Even your backyard could be a great place to go birding. Tuesday will still likely have some of the same birds that have found a good place to rest/eat. And it could produce some more surprises that may not have been found in the vast birding areas on Monday. But it will likely be rainy/snow making birding less appealing. Let me clarify about the Tuesday winds... 6am: https://earth.nullschool.net/#2020/09/08/1200Z/wind/isobaric/850hPa/orthographic=-107.79,50.66,1205/loc=-105.080,40.187 Winds are cut off from the very far north pathway. And there seems to be more of a passage over CO rather than a stop in CO. 12pm: https://earth.nullschool.net/#2020/09/08/1800Z/wind/isobaric/850hPa/orthographic=-107.79,50.66,1205/loc=-105.080,40.187 Pattern is done for most of CO. It looks like NM will be seeing the best pattern at this time, but they aren't seeing the benefits of the very far north pathway being open. So, I wish you a happy Labor Day early and hope you get the gift you have been wanting... a holiday/day off from work AND good birding. Let me know how this lands on Monday or Tuesday by reporting anything and everything you see. All data is good data. Thanks, 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 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/CAENnWHsJA10JJ2_WNyRDb0tkaQ0FZpgx0DL58jGyw4E_aUKm1w%40mail.gmail.com.
