9/18/26 Friday 3:30 am
Poor initialization from the evening models. The GFS was closest; the midnight run is just coming online and is much drier than the European. The updated European won’t be out for about 90 minutes.
Yesterday, the central portions of the forecast area were the big winners. Somewhere east of Mancos was the dividing line between heavy and light precipitation.
Yesterday, the model’s error was having the main moisture transport too far west. Looking at yesterday’s accumulations around Cortez and Mancos, it’s clear they were on the less productive side of the flow.
However, the overwhelming amount of precipitation yesterday has kept the atmosphere completely saturated. Dew points across the forecast area are 53-55 degrees, which is similar to the air temperature (basically 99% humidity).
Here is the recent satellite shot.
The yellow tones you see indicate drier air. The green is a very moist flow.
Here is the satellite in motion between 12:30 am and 4:20 am
You can see that moisture in New Mexico rotating back into our forecast area. You can also see the yellow (dry air) tracking east, approaching our area. Dry and saturated air masses can be convective where they clash. So I will be keeping an eye on that today.
5:45 am
The Euro is finally out; while it initialized better than the prior run, it differs from the GFS, likely due to bias. GFS shows the heaviest rain today over far eastern La Plata County. The Euro shows it directly over La Plata County.
Both models show much lower totals than we have seen lately. As I said the last couple of days, it is hard to believe the residual moisture (54-degree dew points and 175% PWAT) won’t play a role in shower development. Especially if we see the sun out for a little while late morning. For those wanting a dry weekend, it is looking more and more likely. I will follow up on that this afternoon.
Lastly, from the Wishcast chronicles:
I noticed this on the GFS at the end of the month. I have written about a high probability of a recurving Pacific Tropical Storm due to above-average development so far in the region. As an added bonus, this shows a recurve with a powerful cold front on track to clash.
The heaviest rain (historic flooding) our area has ever had is from recurving Tropical Storms. I don’t hope for flooding, but any confirmation that October through December will be colder and wetter than average, as the longer-term models have continually indicated, is encouraging.