Ridge, TroughOctober 22nd, 2013 at 1:03 am by Bill Steffen under Bill's Blog, Weather
Click on the images to enlarge. The map on the left is the 500 mb map. This is a constant pressure surface about 18,000 feet above the ground. The wind tends to flow parallel to the solid lines. Note the ridge in the Western U.S. and the trough sitting smack dab over the western Great Lakes. Under the ridge, the weather is often sunnier, dry and warmer. Under the trough, the weather is often cloudier, wetter and colder. The second map is high temperatures from Monday. Note how the temperatures tend to follow the ridge trough, with warmer highs generally under the ridge. (Maps courtesy of SUNY).
First 2 weeks of October, G.R. had 67% sunshine. The last week we had 16% of possible sunshine. We have had at least a tenth of an inch of rain on 6 of the last 7 days (and the 7th day we had sprinkles). Rainfall this month in G.R. thru 10/21 is 3.79″, that’s 1.59″ above average for Oct. 1-21. For the year, G.R. has had 37.36″ of precipitation and that’s 6.16″ above average. Here’s snowfall totals in the U.P., Minnesota and N. Dakota. Here’s harvesting this (Tue.) morning in the snow in Iowa. From the U.P., Atlantic Mine reports 4″ of snowfall, 3″ near Houghton (less at MI Tech.).
Latest first 32 deg. temperature in G.R.: 1) Nov. 14, 1918 2) Nov. 11, 1897 3) Nov. 9, 1938 4) Nov. 6, 1940, Nov. 6, 1931 6) Nov. 5, 1927 7) Nov. 2, 1932 Nov. 2, 1921 Nov. 2, 1919 10) Nov. 1, 1971 (data courtesy of the GRR NWS). Note note of the years were recent.
Here’s a Guide to Extraordinary Clouds, a pic. of the fires in SE Australia, a happy snowman in the U.P., Acapulco had 6″ of rain from Hurricane Raymond. Arctic ice extent now (Oct. 22) at greatest extent for any Oct. 22 since 2005.