Luke Victor

Some across the state had their first real taste of fall and winter-like weather
this past weekend. Unfortunately, as has been the case for 2024, there were
plenty of HAVES... and MANY have nots! Below is precipitation analysis over the
last 7 days, including moisture from this past weekend's storm. 

This storm ended up going a bit too far south for Denver and points north, but
most places along and south of the Palmer Divide did well, and in some cases too
well in terms of rainfall. Plenty of areas in northeast New Mexico saw over half
a year's worth of rain in a couple days, with Roswell, NM experiencing flash
flood emergencies.

Following this storm, we've been put in another bit of a rock (or ridge, if you
will) in a hard place. The 500mb anomaly loop keeps us under a powerful ridge of
high pressure for MOST of the next 5 days. A very weak system passes overhead
Thursday and Friday and will bring slightly cooler temps and gusty winds. 

You'll notice by the end of that loop some changes down the pipe – a strong
system pushing onshore of the PACNW.

This could be a potential "parade" of storm systems as mid-to-long range
modeling has a pretty clear signal to an active MJO cycle moving across the
Pacific Ocean towards the US in the last week of October.

Any time you see the MJO charts above "rounding the bed", you know the
atmosphere is on the move – essentially we're not getting stuck in a singular
weather pattern (much like we have so far this fall). With the transition of the
MJO from phase 6, into 7 and 8 through the end of the month, there is a much
higher likelihood we see our most significant pattern change so far this season. 

Another piece of data that supports this is what's called a Hovmoller diagram.
It plots out time on the left side of the chart. At the top, what's happening
now, and extending outward in time as you follow the graph downward. 

Areas of orange indicate rising motion in the atmosphere, condusive to
storminess, while the greens/blues indicating sinking motion, leading to calm
weather.

Notice around 25 Oct 2024, how most of the oranges are on the far left of the
chart, indicating stormier weather over the Indian Ocean and Asia – and as we
progress through time, that unsettled pattern shifts from west to east as we
approach early November... another key indicator that we are seeing the
atmosphere keeping things moving. 

This would-be pattern change includes the potential for more moisture, and
subfreezing temperatures at lower elevations in Colorado. The mountains will
likely also start to gear up on snowpack in this late-October and early-November
timeframe for the high country folks.

If we were to try to pin down a couple dates for what we're watching: it looks
like Halloween (classic Colorado...) and a few days after that could be an
active spell of weather for us. As always... changes are expected... but the
writing on the walls is certainly there for us to finally deal a striking blow
to this summer ridge along with our first widespread freeze and snow potential
of the season.

We're ready to walk you through those changes as they happen...

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