Thursday, June 4, 2020

Big Changes Are Coming

Major changes are on tap weatherwise over the next several days.

Today looks to be hot and tomorrow (Friday) even hotter as a closed low off the coast of Baja California begins to fill and lift into the southwest United States.  This leads to strong southerly flow across the Great Basin with temperature climbing and fire weather conditions deteriorating. 

NWS forecast highs for the Salt Lake City Airport are 91˚F today and 96˚F tomorrow.  Disgusting.

Saturday's forecast is crapshootish as the former closed low continues to fill and moves across Utah and a much deeper trough approaches from the west.  Right now, the GFS has the former moving across Utah in the morning and producing showers and thunderstorms producing the heaviest precipitation over central and eastern Utah.

The situation for northern Utah is pretty complicated due to the weak atmospheric stability, a front approaching from the west, and a moisture dryslot.  My guess is that there will be some decent weather on Saturday, but the threat of some showers and thunderstorms is real, so keep an eye on the radar, another on the sky, and adjust as needed. 

Right now, the GFS has the frontal band approaching Salt Lake City late Saturday and over Salt Lake City by 0300 UTC 7 June (9 PM MDT Saturday). 

That will be followed by cooler weather with periods of showers and possible some thunder as the pattern will be markedly springlike.  The NWS forecast high for Monday is 59˚F, nearly 40˚F lower than their forecast for Friday. 

If you are recreating this weekend, be aware that changes are coming and consult NWS forecasts.  Expect some evolution in forecast details (e.g., the timing of the front or periods of thunderstorms or showers), but the threats for critical fire weather conditions Friday and thunderstorms and heavy rain that could produce flash floods in southern and eastern Utah are real, as well as the overall cooling trend.  NWS flashflood information available at


  1. SPC has a marginal risk up for both today and tomorrow for portions of Utah. Haven't seen that in a while.

    1. Yeah, I've been hoping to write a post on this, but don't know yet if I can squeeze in.