593
FXUS65 KBOU 131135
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
535 AM MDT Mon Oct 13 2025

.KEY MESSAGES...

- Showers redeveloping over the mountains by afternoon, with
  scattered showers drifting onto the plains.

- Mainly dry with above normal temperatures Tuesday and Wednesday.

- Precipitation chances return late Wednesday into Thursday across
  the mountains and plains. Cold enough for snow in the higher
  mountains.

&&

.DISCUSSION /Through Sunday/...
Issued at 232 PM MDT Sun Oct 12 2025

An upper level low will dive southward along the West Coast
through Monday night. This will allow for SW flow aloft across the
area.  Cross-sections show an increase in mid level moisture across
the area Mon thru Mon night. Weak disturbances embedded in the
flow will bring a chc of rain and snow showers to the higher
terrain with a chc of rain showers over the far nern plains mainly
late Mon aftn and night.

On Tue, an upper level low will move from central California into
wrn portions of the Great Basin by Tue night. As this occurs the
flow aloft will become more SSW. Cross-sections show limited
moisture across most of the area thru Tues night so dry conditions
are expected with seasonal temperatures.

From Wed thru Wed night, an elongated upper level trough will
gradually develop from the nrn Rockies into the Great Basin, as a
significant piece of energy moves northeast from the main upper
level low.  This will allow for mainly dry SSW flow aloft across the
area thru Wed aftn.  Temperatures will be above normal with gusty
south winds across the plains.

By late Wed night into Thu, the srn portion of the elongated upper
level trough will move across nrn CO.  This will allow for a better
chc of rain and snow showers across the higher terrain.  Over the
plains a cold front will move in by Thu morning bringing in cooler
temperatures.  QG fields show some ascent thru the aftn which may
allow for a chc of rain showers over the plains.

For Fri thru Sat, there are some differences between the ECMWF and
GFS. Sat The GFS has the upper level trough move east of the area
with dry conditions and seasonal temperatures.  Meanwhile, the ECMWF
has another piece of energy moving into the Great Basin Fri night
and then across the area on Sat.  As a result, this would bring a
chc of precipitation to the area along with cooler temperatures.  At
this time will go with the blended solution which is mainly dry with
seasonal temperatures.

&&

.AVIATION /12Z TAFS through 12Z Tuesday/...
Issued at 532 AM MDT Mon Oct 13 2025

VFR through tonight. A mid level cloud deck with ceilings between
7 and 10 thousand feet will likely lower a bit with increasing
moisture and scattered showers after 18z Monday. Areas of ceilings
5 to 6 thousand feet AGL may require instrument approaches to
KDEN after 21z through 06z Tuesday.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 8 AM MDT this morning for COZ038-042-043.

&&

$$

DISCUSSION...63
AVIATION...Gimmestad