Monday Update & Denver Weather

April 8, 2013

Our weather doesn’t look too exciting over the next 5 days at least.  Maybe some cold/active showers this weekend (you know, hail, thunder, gusty wind). 

But did you see what happened in Colorado this afternoon/evening?  Just ahead of our cold upper low that passed over the weekend is a very warm air mass over the Great Plains.  Denver’s temperatures jumped into the lower 70s.  Now a very cold late season arctic air mass is surging south across all that flat land.  See what happened?  Summer to winter in just a few hours:

MarkDenverChanges

That sure doesn’t happen here!  Our air masses are modified by the proximity to an ocean that varies only about 10 degrees from summer to winter.  Plus we have no flat land between here and the arctic that would allow that really cold air to flow south.  Our 10pm producer Melanie grew up in Chinook, MT in a similar climate east of the Rockies.  She said even that is rare in April.  By the way, a huge snowstorm develops the next two days from that area northeast all the way to Minneapolis.  Check out those 10-20″ snow forecasts across the Dakotas and Nebraska/Minnesota.  A nice spring snowstorm.

RPM_SNOWACCUM_USA

Models are in pretty good agreement that we see cool troughing back over us this upcoming weekend and at least part of NEXT week.  So if you’re looking for warm sunshine you’re going to have to wait awhile.

For the geeks, here is the 00z GFS 850mb ensemble chart:

tseries_850t_000-384_Portland

The 12z ECMWF ensemble chart:

tseries_850t_000-360_Portland

And the monthly run of the ECMWF from last night; the average of each week’s 500mb heights:

500za_week1_bg_NA

500za_week2_bg_NA

500za_week3_bg_NA

500za_week4_bg_NA

Chief Meteorologist Mark Nelsen


A New NWS Tool

April 8, 2013

Jonathan Wolfe sent me this link a couple weeks ago.  You may remember him from the Portland NWS; he’s in Charlston WV right now

http://preview.weather.gov/edd/

It’s an experimental product that incorporates mapping, model info, NWS forecasts, grids etc…

Here’s an example:  http://tinyurl.com/ck3ctud

I used it on IE 8 or 9, or whatever our IT people allow and it’s a little slow.  It’ll be interesting to see if it works a little better on another or faster browser?

Have fun!

Chief Meteorologist Mark Nelsen