Ending October with an Early Snow Storm
October 29, 2011 8:53 PM
Halloween is approaching and while the New England States are receiving an early snowstorm…here in the northern plains we'll be receiving a treat of our own on Monday…ours however won’t be quite as cold. As a matter of fact highs will be around 60 degrees on Halloween with temperatures in the 40’s around trick or treat time with partly cloudy skies.
This is actually the first time on record New York City has received any snowfall in the month of October…many places in the northeast haven’t even seen their first frost before today’s snow storm. Places in Massachusetts have seen around 20 inches so far and the list is expected to climb over the next several hours. Around 2.5 million people are currently without power, and many flights are postponed if not canceled throughout major airports in the northeast. Snowfall rates were around 1 to 2 inches an hour with gusty winds, lowering visibilities. A lot of moisture is associated with this weekend’s storm, weighing down tree limbs and power lines. It is not out of the ordinary for the northeast to have a Nor Easter, but it is the early snowfall, which is surprising. A Nor Easter typically occurs along the eastern seaboard and combines the cold Canadian air with the warmer waters of the North Atlantic to give states a mix of heavy snow and strong winds. With this weekend’s event, the low pressure began in the Tennessee Valley and quickly strengthened or bombed out as it traveled northeast. Notice the pressure change from Friday (1012) to Saturday (998)..image courtesy the Storm Prediction Center. Also notice how close together the lines are on the second image, indicating strong winds.
It is not unheard of for us to get our first snowfall in the month of October, but most of our major snow events dont' occur until November or December. The graphic below shows snowfall totals over the past four years for the month of October…on this graphic the year 2009 sticks out with around 3.5 inches reported in Sioux Falls and Mitchell.
No snow is in our forecast over the next two days, with warmer air arriving on Halloween. The image below shows temperatures at the lower levels of the atmosphere notice the greens and yellows working there way from the west to the east on Monday, indicating warmer conditions. The second graphic is a timetable of highs over the last several years in Sioux Falls. Thankfully, this year’s high is not going to be anywhere close to the frigid 35 degrees we reached in 2006.