Brendan Heberton

Brian Bledsoe

The “leftovers” of the summer monsoon have still been kicking for parts of the
Desert Southwest over the last 30 days, but areas farther east have been largely
shut-out. You can see how much drier it was for Southeast Colorado, Southwest
Kansas, and the Panhandles, versus areas farther west and north. 

Zoomed in to Colorado one can see that for many locations the last month has
actually been a positive in the precipitation department, even as some parts of
the state (particularly the southeast corner) remained dry. 

A decent monsoon this year did make a dent in the overall drought picture,
particularly for those across the Four Corners region. 

For portions of central Colorado this equates to areas entering the fall
drought-free, even as that quickly changes for the worse as you head east in to
the southern and central plains. 

The main player in our longer range forecasts continues to be La Niña. It
remains quite strong, and does not show signs of wanting to immediately go away.
Current sea surface temperature anomalies look like this:

All of that blue shading in the equatorial Pacific Ocean is the La Niña. The
probabilities of La Niña lasting this winter are pretty good. Beyond winter,
most models and conventional wisdom suggest that La Niña will fade. You can see
the probabilities for such, below:

Our thinking is La Niña is maxing out now through early winter, and then will
gradually start to go away. In the meantime, that doesn’t help us much. Most
modeling suggests that the next two weeks will be drier than average for most of
the region, the exception being across the far south and southwest: 

Now, for those hoping for a pattern shift... there may be one one the way for
the final days of the month, but its impact on Colorado (particularly east of
the hills) remains unclear. 

Currently we have a large ridge parked over the Pacific Northwest, with the
cooler than average anomalies over the Great Lakes and Eastern U.S.: 

The same model has a much different idea for the last days of the month, which
would bring some cooler and unsettled weather to the West. 

Some models swing a system all the way through as we transition to this pattern
and with it some rain and snow for Colorado, while other models keep the eastern
half of the state on the dry and mild side. We'll see. 

The above makes sense when looking at the seasonal models as we kick off
November. The latest EURO Seasonal Model and NMME Model both suggest average to
drier than average for the region, though perhaps we finally start building some
snowpack across the intermountain west and even into Western Colorado: 

Fingers crossed that when we chat again next month, that there will be further
evidence of La Niña coming to an end on schedule, if not sooner.

Regional weather Insiders update: October, 2022