Matt Makens

Although temperatures Monday and Tuesday are warmer than average, the first of
two storm systems arrives Wednesday to drop temperatures and bring some rain and
snow to Colorado.

This pattern is what the GFS started advertising quite a while ago with a
southwestern US cutoff low and subsequent wetter weather across the state.

A cold front Wednesday will kick things off with cooler temperatures and rain to
snow chances from the afternoon through the evening.

As that system scoots east, the cutoff low will pass energy through the state
Thursday into early Friday, and this is likely to be the bigger of the two
impacts, although the scale of the impact for the metro areas is moderate to low
- in our interpretation.

Out of the combined impact, here are the snowfall totals through Friday morning
in the GFS/GENS and EC/ECENS:









Out of those four, you see rather good agreement on placement and totals of the
snowfall.

Our Gamblers Charts show the confidence in those numbers, the higher confidence
for accumulation is for Castle Rock.



This event was what was drawing some attention to the GFS about ten days ago,
which at that time had a much stronger event for us. The atmosphere-ocean
teleconnections never really supported that 'big storm' forecast at the time.

The teleconnections do, however, support a cooler and more unsettled change to
come for the second half of November.



The dropping PNA Index and the slightly negative NAO Index support a colder than
average period of weather with opportunities for some energy to come at Colorado
from a more southwesterly fetch.

The MJO Index also supports some changes as it floats from phase 8 to 1 for the
rest of the month. For our area, that usually equates to colder than average
conditions and wetter than average conditions.



Analogs to the current pattern also show cooler and wetter than average
conditions.



In all, we are confident the next two weeks will be more active than the first
half of the month, which, through the 17th, is drier and warmer than average.





Will there be enough cold air and moisture to overcome the month's climate so
far? Not likely to overcome, but the next two weeks will be more weather-active.
Here are the Euro's ideas for precipitation and temperature anomalies through
the rest of November.

Weather impacts return this week, more active days rest of November