Thursday, December 29, 2005

 We got a situation here 

Another turbulent, windy day here in the Front Range today. Here's a glance at the NWS Boulder forecast discussion:

FXUS65 KBOU 292146
AFDBOU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER CO
245 PM MST THU DEC 29 2005

.SHORT TERM...UPPER TROF CONTINUES TO MOVE ACROSS SOUTHERN WYOMING
WITH ASSOCIATED SURFACE FRONT THROUGH LOGAN AND WASHINGTON COUNTIES.
TIGHT GRADIENT ACROSS THE AREA...WITH BORA SITUATION ACROSS THE
PLAINS. CURRENT GUSTS ARE BELOW HIGH WIND CRITERA. LATEST MODELS
SHOWING 850 MB WINDS AT 30 KTS THROUGH 00Z...THEN DROPS OFF AFTER
THAT. SO...HIGH WIND EVENT MARGINAL AT BEST AND NO HILITES AT THIS
TIME. AS GRADIENT RELAXES THIS EVENING...WINDS SHOULD DECREASE AS
WELL.

I quickly realized that I didn't really know what a "Bora situation" was. I mean, I know it's one of those named winds of the world, but I wasn't even sure where it occurs and what specific meteorological phenomenon it refers to. With a little research (and remembering that an old acquaintance of mine, Jan Null, wrote an article for Weatherwise about it some years ago), I learned that it's basically a wintertine katabatic (downslope) wind of the Balkans and the northeast coast of the Adriatic in the Mediterranean. The name Bora is derived from the Greek God of the North Wind, Bureas, since the wind as it is experienced always seems to be from the north. It can be quite strong at times, as it originates at elevation in the Balkan Alps and the plateaus of western Russia, and descends rapidly to the sea through mountain valleys. The cold air, although warming adiabatically in its descent, is still too cold to be warmed as much as the air it displaces, and so often is felt as a cold wind nonetheless.

This certainly jibes with my experience today. The temp at 7 am was actually 50, but cooled about 5-7 degrees afterwards as the Bora situation began in earnest. You learn something new every day.

tags:

Comments:
I read over your blog, and i found it inquisitive, you may find My Blog interesting. My blog is just about my day to day life, as a park ranger. So please Click Here To Read My Blog
 
Post a Comment


This page is powered by Blogger. Isn't yours?