Monday, June 11, 2018

Forecasting Bud Is a "Three Body" Problem

Tropical Cyclone Bud is currently a category 3 hurricane lurking off the Pacific coast of Mexico west of Acapulco.

Source: National Hurricane Center
Interest in this storm is quite high in the southwest U.S., which was extremely dry this past winter, with the four-corners region in the grips of exceptional drought. 

Source: The National Drought Mitigation Center
The situation is so bad that the US Forest Service has plans to close the entire San Juan National Forest to most public entry this week due to wildfire concerns (for more, see this article).  

There's no quick fix for exceptional drought, but some models are suggesting that moisture from Bud will stream into the four-corners region late Friday and over the weekend.  Below, for example, is the GFS forecast valid 1200 UTC (0600 MDT) Saturday, showing high numidity and precipitation across southeast Utah, western Colorado, eastern Arizona, and western New Mexico.  

How this all shakes out, and whether or not the southwest will be drinking Bud or Bud Light, will depend on the interaction between three major atmospheric features, identified below in the GFS 102 hour forecast valid 1800 UTC (Noon MDT) Friday.  Think of this as an atmospheric equivalent of the three body problem. 

The first is Bud, the remnants of which are expected to be over southern Baja California noon Friday, with moisture streaming northward.  The second is a short-wave trough over southern California.  The third is a stronger upper-level trough expected to be over the Pacific Northwest.  The interplay between these three features will largely determine the track of Bud and the pathway of moisture into the southwest.

Of course, Colorado has plenty of Bud as it is, so it would be nice if this tropical moisture could find its way to Utah.  

No comments:

Post a Comment