A Dry Five Days, With Welcome Warming, Thanks To Omega

Get out your sun shades and put away your umbrella–the subsequent 5 days must be vivid and dry right here in western Washington.

Who are you able to thank for this meteorological bounty?  The greek letter omega.

The whole precipitation for the 5 days ending Friday at 11 PM from the European Center mannequin is, nicely, zero over most of western Washington. Bizarrely,  all of the precipitation can be going into usually a lot drier California!  Here is the California precipitation whole for a similar interval.  Wow.  Much of California, notably within the mountains, will get a number of inches.  While we’re dry.

This excessive distinction in precipitation and the persistence of the sample this week is because of a extremely persistent “locking” of the environment referred to as an “omega block.”  To illustrate, listed here are the forecast higher stage (500 hPa) heights (like stress)  for Tuesday night.  The strong traces are the heights and the colours symbolize anomalies from regular (blue is lower–a trough, orange is larger than normal–a ridge).

There is a ridge, with two adjoining troughs/lows to the SE and SW.    Doesn’t it appear like the Greek letter “omega”? (see beneath)
This omega configuration could be very, very steady and might stick round for days (and even longer).  The Northwest is straight away downstream (east) of the ridge of excessive stress/heights, thus we could have dry skies and warming temperatures.

Those poor people in California are downstream of the low/trough, bringing them unseasonably cool temperatures and plenty of rain.

Because of the ridge, temperatures will progressively heat through the week.  Here are the temperature forecasts from the European Center mannequin for this week in Seattle.  Temperatures first rise into the fifties after which to 65F on Friday.  Can you think about how good that can really feel?

After getting by means of a March that was cooler than a  regular January, we deserve this.  For California, the cool/moist climate is nice news–filling the reservoirs, upping the snowpack, and delaying the inevitable fires.