Tuesday’s Severe Storm Wrap, Colder Temps, Wintry Precipitation and Autumnal Equinox
Wednesday, September 19th, 2012
Thanks to Neil Weaver Photography for the beautiful picture below! It’s a beautiful sunset from Grand Haven, MI on the eastern shore of Lake Michigan.
This is what Neil had to say about the sunset: “Tonight was awesome. I got soaked by three separate waves while standing here but I really didn’t care too much with this view in front of me – Grand Haven, MI”
Tuesday’s Severe Weather Wrap
Thanks to Tarin Bready from Green Island, NY. Strong thunderstorm rolled through with strong enough winds to knock over this tree.
Tuesday’s Storm Reports
The Storm Prediction Center is reporting over 100 damaging wind reports from Tuesday, most of which occurred in the Northeast.
Thanks to @C_Bishi for the picture below out of Winchester, VA. Radar estimates out of this area suggest nearly 2″ of rain over the last couple of days.
Radar estimates of rainfall from Monday & Tuesday show a large swath of heavy rain from the Gulf Coast States to the New England States. Some of these areas saw nearly 3″ to 6″ or more since Monday!
Much Cooler Behind the Front
The 24 hour temp change map from earlier Wednesday showed reading nearly 15° to 25° cooler than they were AM Tuesday! The other big change is the 24 hour dew point deficit… those numbers are about the same, which indicates that there is about half as much water in the atmosphere as there was yesterday.
(Every 20° dew point drop = Cuts the amount of water in the air in half)
(Every 20° dew point increase = Doubles the amount of water in the air)
Thanks to the passage of a strong cold front, high temperatures near and around the Great Lakes region will be much cooler than average.
High Amplitude Weather Pattern
The high amplitude weather patter can be attributed for the now persistent cool pattern across the east and the continued warm weather out west. The jet stream or strong upper level winds have become “stuck” across North America and I don’t see this changing until maybe the end of the month.
6 to 10 Day Temperature Outlook
The Climate Prediction Center continues to show the puddle of cold air across the eastern half of the nation, while temperatures out west have a good chance at staying above average.
Interesting Happenings In The Cold Air
I though this was neat… We received a picture from Wellston, MI yesterday of ice pellets. Temps behind the same strong cold front that brought severe weather to the East Coast yesterday, brought wintry precipitation to the Great Lakes as well.
(Photo Courtesy: Phil Webber)
Open Cellular Convection
Temperatures aloft across the Great Lakes region on Tuesday afternoon were cold enough to create an unstable atmosphere. The sun (still a few days from the Autumnal Equinox) is still fairly strong, so creating this instability isn’t all that difficult. As the sun heats the ground through the day, pockets puffy cumulus clouds develop. Some of these grew into scattered rain/thunder showers with convective-like precipitation. In some cases, the updraft within the cloud was strong enough to shove the water droplet high enough into air to produce small ice. Some of these ice particles fell to the ground as seen by the picture above. The process explained here and seen via visible satellite below is described as open cellular convection.
Decaying Evening Shower
Here’s another shot from Phil Webber from Cadillac, MI. This area was within the open cellular convection area mentioned above. As the sun’s energy and instability faded through the late afternoon/early evening hours, so did the spotty shower activity. The picture below shows a decaying cumulus cloud, likely responsible for scattered showers and possibly ice pellets earlier in the day.
More Ice Pellets/Snow?
With a persistent northwesterly flow across the Great Lakes Region, several more chances of scattered rain/ice pellets/snow showers will be possible into the weekend. NOAA’s HPC 5 day rainfall forecast keeps most of the precipitation chances in these areas through early next week.
One of the extended model runs from earlier today (GFS) suggests that there could be some light snow/flurries possible early Saturday morning across parts of Minnesota… Not sure we’ll see anything stick, if any snow does fall, but I thought this was worth a mention!
Thanks for checking in on this Wednesday, have a great rest of your week!
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