041 
FXUS63 KDMX 291144
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
544 AM CST Fri Dec 29 2023

...Updated for the 12z Aviation Discussion...

.DISCUSSION.../Today through Thursday/
Issued at 319 AM CST Fri Dec 29 2023

Key messaging:

- Slight chance (<=20%) of light snow northeast Sat night

- Mainly dry with seasonal temperatures much of next week

Our weather regime will be less active into next week with the 
only brief and minor precip window north and northeast Saturday 
night as we transition to varied degrees of northwest flow aloft. 
At onset early this morning, lingering effects of the finally 
departing OH Valley upper low were just exiting southeast 
sections. Intermittent light snow or flurries remain possible
southeast, although this precip should end soon with considerable
2-3km dry air between mid level clouds and stratus. Low clouds 
will linger through at least the morning however, with some 
clearing possibly through the afternoon.

Our attention will then turn to the weekend as an upper trough 
moves through the Canadian provinces today and reaches the Upper 
MS Valley late Saturday. Much of the lift associated with this 
system appears to be mid level and kinematically forced with 
insufficient moisture initially, however this vertical motion and 
following cooler air eventually leads to deeper moisture 
approaching saturation. Recent NBM runs remain dry, likely its 
typical low PoP/QPF bias, however the guidance consensus suggest 
at least some mention is warranted this far south and west. The 
GEFS is less aggressive, but the inclusive of somewhat more 
bullish EPS/GEPS measurable probabilities suggest at least a 
slight chance (15-20%) for a period of light snow or flurries 
Saturday night. Although the lift is near neutral or in QG 
subsidence, soundings suggest the column could have sufficient 
moisture depth.

This should be followed by short wave upper ridging late Monday, 
and then the passage of another system similar to this weekend 
late Tuesday into Wednesday, both in terms of track, forcing, and 
moisture parameters. There doesn't appear to be adequate phasing 
of moisture and lift to introduce precip at this lead time, but a 
brief window of token, light precip can't be ruled out north and 
east by the middle of next week. This pattern with northern stream
influences, but with the lack of any arctic airmass tap, will 
keep our temps within seasonal values for late December and early 
January.

&&

.AVIATION.../For the 12Z TAFS through 12Z Saturday morning/
Issued at 543 AM CST Fri Dec 29 2023

MVFR-LIFR ceilings continued to cover much of central IA at 12Z.
The general trend is expected for this stratus to diminish north
to south by this afternoon in most locations. However confidence 
is low, and it could potentially linger longer into at least the 
evening.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

DISCUSSION...Small
AVIATION...Small