Tuesday, April 09, 2013

If You Think Our Weather Is Wacky...

If you feel that our recent jump in weather from March to late May is a bit wacky, it isn't the wackiest on the map. Such spring flings where we go from chill to warmth aren't unprecedented around here...we outlined yesterday that there have been several instances in our recorded weather history of first 80 degree days also being the first 70+ day.  These surges of warmth have happened before and will happen again in April.

For everyone who gets warmth, someone has to pay the price in response.  That payment was made in Denver. Yesterday's high was 72...last night was their transition from April to January...and this morning they are in the icebox with wind-whipped snow and temperatures near 20 degrees.

That transition is made due to a storm system that will impact us on Thursday night and Friday, which organized in the Rockies yesterday and pushed out into the Plains.  Showers and storms fired east of the Front Range (which Denver resides at the base of) yesterday afternoon, prompting the issuance of severe thunderstorm watches late in the afternoon hours.

The severe watches were out east of Denver, with winter storm warnings, watches, and blizzard warnings out for the Denver metro.  By 9 PM our time, thunderstorms moved through much of Northern Colorado and prompted the issuance of tornado warnings in a few locations, including one to the east of Denver where there happened to be a winter storm warning in place.  Odd combination but you can see how those thunderstorms and the cold front associated with them had already started to impact Denver -- temperatures had dropped from around 70 at 3 PM to around 40 at 9 PM last night.

The thunder threat pulled away by around 11 PM our time last night as colder air poured in.  Temperatures around Denver early this morning dropped from the 40's last night to the upper teens this morning.  In Limon, CO, temperatures dropped from 63 at 9 PM to 19 at 5 AM.

This same storm system is also poised to nail the Dakotas and Minnesota with a heaping helping of snow, perhaps as much as two feet in some parts of the Dakotas by the time this is all done.  Around Minneapolis, ten or more inches of snow is possible with this storm although water content will be quite high and some of this may mix with sleet and freezing rain at the onset.  That said, such heavy snow in April isn't completely unusual -- on April 14th, 1983, over a foot of snow fell in Minneapolis and around five inches of snow fell on April 29th and 30th, 1994.

Snow isn't expected here...a snowfall of pollen may occur in spots by week's end though!