The Northern Lights should put on a show, particularly in the North Country! So, have your cameras at the ready and I'd love to see your images on Facebook, Twitter or at the Sky Scenes Flickr photo sharing group. Read on for all the details you need to know!
The recent solar flare eruption on Thursday has thrust as coronal mass ejection - a wave of solar energy - toward Earth, and that energy is expected to hit the upper atmosphere on Saturday. This energy often can excite molecules in the upper atmosphere, and the product is the aurora borealis, or what is more commonly termed, the Northern Lights. The amount of energy expected to arrive Saturday is enough to warrant an "Extreme" forecast of Northern Lights by the Geophysical Institute at the University of Alaska Fairbanks, as portrayed in this Saturday night forecast map. This is exciting news for residents of the Northern Tier of the United States (and especially those farther north, of course!) because the displays may be visible in lower latitudes that aren't always treated to aurora. In the forecast image, the solid green ring represents expected frequent displays of the Northern Lights Saturday night, while the non-shaded area within the ring represents the area that some aurora may be witnessed.
The next question, of course, revolves around the weather: will it be clear? I expect the wildfire smoke that obscured the sky from the Great Lakes to New England Friday to be gone. This leaves clouds as the first variable to contend with. I've included a forecast map of expected rainfall and clouds (click the image to enlarge, and the legend for cloud altitude is at the bottom of the image) - a representation of one computer guidance product (image courtesy Penn State University). Note that most of Northern New England looks clear, but the farther south - or west into Upstate NY - one is, the more clouds may litter the sky. Regardless, this is great news for Northern New Englanders Saturday night. Across the remainder of the nation, the other area that looks to be mostly clear is Minnesota and Wisconsin. The second big variable, though, is light pollution, and this just as big of a factor to viewing the aurora as clouds. So many people I hear from in Central and especially Southern New England are disappointed during events like this, or meteor showers and the like. The sky is clear, you can see the stars, but no display. In these instances, the culprit almost always is light pollution - too much ambient light from nearby shopping plazas, street lights, etc. Most communities have not required installation of shields atop these lights (which are not expensive and substantially limit light pollution, by the way), so that light bleeds into the night sky, and even if you can't see the "glow" of a nearby plaza, it still reduces fainter images in the night sky. So, head north and head rural...and don't forget your camera! I'll be looking for your awesome shots this weekend on Facebook, on Twitter or on the Sky Scenes photo sharing group.
Update: Many have asked about timing of the display. There is no set time that is best - essentially, your best display will come when the energy hitting our side of the Northern Hemisphere is substantial. So how do you know exactly when? This image, below, is directly linked to the NOAA POES Auroral Activity site, and I'll leave it right here on this post. So, essentially, just refresh this page and you should see it updated hourly to see if the yellows and reds (indicating increased activity are on our side of the globe) are dipping close to the Northern Tier of the US.