Hi everyone, For the spring migration season I am going to try to post weekly "migration forecasts", with predictions for the following 6 days. These are mainly focused on southern Ontario, as that is the region I am most familiar with, but I will include comments on other areas of Ontario occasionally. *Please note that these are just my personal predictions & are by no means a sure thing. So if you consult only this to plan your trips, don't blame me if there aren't many birds that day : ) Ontario Migration Forecast - April 4 to April 10 Overview After lasts weeks surge of warm air, a large number of new migrants arrived across Ontario. The good conditions only lasted a few days though, as things cooled off during the weekend. Tonight (April 18th) and tomorrow there is a chance that southern Ontario will receive up to 10cm of snow, which means very poor migration conditions until likely Wednesday. The snow could be interesting depending on how much we get though, as it might drive some rarities to bird feeders and more sheltered habitat. Migrant numbers should pick up as the week goes on, increasing on Thursday and then again over the weekend. We aren’t quite in the “crazy season” yet, but this week could still be quite good. - Likely New Arrivals This Week; * (Note. By “new arrivals” I mean low numbers of these birds, or the first one or two, showing up in the province. Usually Southwest Ontario gets birds about a week or more before other areas in the province too) - Broad-winged Hawk - Green Heron - Common Tern - Long-billed Dowitcher - Upland Sandpiper - Spotted Sandpiper - Sora - Common Gallinule - Cliff Swallow - Bank Swallow - Blue-gray Gnatcatcher - Blue-headed Vireo - Chimney Swift - Red-headed Woodpecker - American Pipit - House Wren - Sedge Wren - Black-and-white Warbler - Black-throated Green Warbler - Northern Waterthrush - White-throated Sparrow - Migrants arriving in large numbers: - Blue-winged Teal - Lesser Yellowlegs - Greater Yellowlegs - Piping Plover - Wilson’s Snipe - Caspian Tern - Forester’s Tern - Sharp-shinned Hawk - Osprey - Common Loon - Great Egret - Black-crowned Night-Heron - American Bittern - Bonaparte’s Gull - Northern Rough-winged Swallow - Purple Martin - Barn Swallow - Ruby-crowned Kinglet - Brown Thrasher - Yellow-rumped Warbler - Pine Warbler - Field Sparrow - Fox Sparrow - Vesper Sparrow - Chipping Sparrow - Swamp Sparrow - Eastern Towhee - Purple Finch - Rarities to look for this week: - Eurasian Wigeon - Black-necked Stilt and American Avocet (especially in southwestern Ontario) - Neotropic Cormorant (Lake Erie & Lake Ontario in particular) - Snowy Egret and Little Blue Heron - Smith’s Longspur (fields in southwestern Ontario) - Rare geese mixed in with Canada and Snow Goose flocks in Eastern Ontario Daily Forecasts - Tuesday, April 19th North winds, temperatures in the low single digits and a chance snow/rain for the majority of southern Ontario… very poor migration conditions! I expect Tuesday to be the worst day of the week for birding. - Wednesday, April 20th The winds will be pretty nonexistent all day (very light south/southwest) and it will be a bit warmer than Tuesday. It should be sunny for a lot of the day and no precipitation should get in the way either. Overall I expect it will be a decent migration/birding day, with a small, but noticeable number of new birds arriving in the province. - Thursday, April 21 Thursday will likely see rain for the majority of the day, with strong southwest wind and warm temperatures (rising into the double digits). If the rain is heavy all night and throughout the day, it will likely shut down movement considerably. I still like it will be a good day for arrivals overall though, just maybe not massive numbers. If you don’t mind birding in the rain it could be interesting… - Friday, April 22 As of right now Friday is predicted to have north winds for the majority of the day. Temperatures shouldn’t be too bad (though still in the single digits) and there isn’t much precipitation around. Some birds will still be moving I’m sure, although it likely won’t be that exciting of a day as far as new arrivals go. - Saturday April 23rd/Sunday April 24th Again, once you start looking at weather five days/a week away, the accuracy of the forecasts goes down. If it turns out to be anything like the models are suggesting right now though, it could be quite interesting. Long distance southwest winds (coming all the way from the gulf coast) are meant to arrive in Ontario on Saturday and persist until early next week. If this happens the birding should be great and we’ll see another large push of new arrivals as well as rarities. Summary The birding should pick up as the week goes on, with a smaller number of birds arriving Wednesday-Friday, then a big surge on the weekend. Thursday could go either way for being a good day, it really depends how the rain plays out. If it doesn’t rain all night and only starts in the morning, it could be worth it looking for grounded shorebirds in southern Ontario. As far as enjoyable birding days go (for not getting wet and having a decent day outside), Wednesday and Friday are probably the best bets. April 21st is traditionally the time of year when “rarity season” starts to kick off in southern Ontario. Given that, and the possibility of really good winds through the weekend, I think it’s fair to say that Ontario could see a nice scattering of rarities within the next week or so. Rare birds often take a few days to get found after they arrive, so Sunday onwards would be my guess for reports starting to pop up. I don’t really feel like making wild predictions, but if I had to guess I would say a rare heron or two (Little Blue Heron, Snowy & Cattle Egret), American Avocet and Neotropic Cormorant. Websites that I use frequently Windy (wind, temperature, precipitation and more) - windy.com Birdcast (good for large scale trends) - https://birdcast.info Accueweather (an easier to read weather site that is normally accurate) - https://www.accuweather.com