Windstorm is Cancelled!

The latest hourly HRRR forecasts are suggesting that the wind event may be MUCH less than predicted, particularly over Puget Sound.

As shown in my last blog, the 4 AM model runs indicated a strong wind event over our region.

However, the latest HRRR forecast pulls WAY back.  Let me show you.  Here is the pressure and wind forecast for 4 PM for the run starting at 7 AM.  Large pressure gradients with low of 986 hPa.

In contrast, the HRRR forecast starting at noon is much more benign, with weaker pressure gradients.

The latest observations along the coast show that the earlier forecast was profoundly in error.  The low center is not developing as predicted.

We can view the wind gusts forecast by the latest HRRR run.  At 4 PM, only the Puget Sound waters will have gusts of 30-40 mph

An hour later, same thing, with strong winds in the eastern Strait.   Much less on the coast.

A sobering example of the difficulty of getting small scale low developments along the coast.  Northwest Washington will get a good blow, but the Seattle area will only get a breezy interlude, if the latest forecasts are correct.

This kind of failure is unusual, but happens.  Sobering.   I am a bit upset with myself...I didn't spend enough time looking at the ensembles (multiple forecasts) this morning....in retrospect they showed considerable uncertainty with the NWS GFS model (which drives the main local high-res predictions) being an outlier from other solutions.  I won't make that mistake again before writing a blog.

This event is a good case study of why we need to transition to probabilistic weather prediction, with full uncertainly information being transmitted to the public.
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And while you are thinking about the winds, don't forget to express your feelings about the proposed termination of KPLU, in the ill-advised sale to UW.  More information here and here.  This sale is marked by secrecy and disinformation by PLU and UW administrators.  KPLU can be saved if listeners tell the UW Board of Regents and the PLU administration to back off.

If any of you are interested in attending a strategy meeting for saving KPLU on Sunday, Dec. 6th at 2 PM, please let me know (you can email me for more information--search on "cliff mass email" to my email address)