National Weather Service Raw Text Product

863 
FXUS63 KDMX 260449
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
1149 PM CDT Mon Sep 25 2023

...Updated for the 06z Aviation Discussion...

.DISCUSSION.../Tonight through Monday/
Issued at 222 PM CDT Mon Sep 25 2023

Key Messages:

- Scattered showers and thunderstorms mainly northeast linger 
through Wednesday
- Warm and dry to finish out the week

Discussion:

The large low pressure system that brought thunderstorms to the area 
on Saturday is taking its time exiting the area and will continue to 
dominate Iowa conditions through midweek. This is easily viewed on 
satellite as the large comma shaped system stands out across the 
midwest. Today impacts have largely come in the form of increased 
cloudiness across northeast to central Iowa into the afternoon. A 
few spotty showers have developed in northeast Iowa, but given 
transient nature of the cells and relatively scattered nature, 
associated QPF is fairly light. As showers diminish overnight patchy 
fog may develop in these areas with light winds and better 
available moisture.

The low continues to churn into Tuesday with the center shifting 
near to Iowa. This will result in continued scattered showers and 
thunderstorms across mainly northeast Iowa. At the same time 
vorticity is enhanced within the vicinity of the surface low and 0-
3km CAPE of 100-200+ J/kg is prevalent within CAM data. As such, 
should be a decent funnel cloud environment in far northeast 
portions of the forecast area, and especially in southern Wisconsin 
to northern Illinois, tomorrow afternoon. The RAP highlights this 
nicely in the non-supercell tornado product. As is usually the case 
with these situations, most funnels will remain just that,  but any 
landspout tornado that does develop (while weak) could pose a risk 
to anyone/thing nearby.

This low finally shifts east starting on Wednesday with 
southernly flow cranking up warm air advection into the area. 
This will send temperatures into the mid 80s by the end of the 
week and weekend, around 10+ degrees above average for this time 
of year. Right now the average high for both Des Moines and 
Waterloo is 74 degrees. The ridge is stubborn and keeps the area 
and warm and dry at least through the weekend, with hints that is 
may last well into early October.

&&

.AVIATION.../For the 06Z TAFS through 06Z Tuesday night/
Issued at 1146 PM CDT Mon Sep 25 2023

Stratus and areas of fog are expected to expand across northern
Iowa overnight and linger into Tuesday morning. Conditions are
expected to drop to IFR to LIFR at times at KFOD/KMCW and possibly
at KALO. At this time, KDSM and KOTM are expected to remain mostly
VFR but will continue to monitor. Light wind overnight and into
Tuesday.

&&

.CLIMATE...
Issued at 302 AM CDT Mon Sep 25 2023

Climate Prediction Center Temp & Precip Outlooks

6-10 Day / Valid Sep 30-Oct 4
   Issued Sep 24
   Temp...Very likely above normal 
   Precip...Leaning above normal

8-14 Day / Valid Oct 2-8
   Issued Sep 24
   Temp...Likely above normal
   Precip...Leaning slightly above normal

3-4 Week / Valid Oct 7-20
    Issued Sep 22
    Temp & Precip...Equal chances. No discernible trend.

&&

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

$$

DISCUSSION...Hagenhoff
AVIATION...Donavon
CLIMATE...Small