757 
FXUS63 KDMX 270851
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
351 AM CDT Tue Aug 27 2019

.DISCUSSION.../Today through Monday/
Issued at 350 AM CDT Tue Aug 27 2019

A weak boundary is moving across Iowa early this morning. A few 
patches of fog have developed ahead of the boundary but have since 
cleared out of central Iowa with the boundary passage.  For today, a 
closed upper low will move across southern Manitoba and into Ontario 
with a strong short wave rotating around the system and into 
Minnesota. The forecast area will be mainly under the subsidence 
region of the short wave. This along with a lack of moisture is 
expected to keep any precipitation out of the area and focused in 
Minnesota and Wisconsin and may clip far northeast Iowa. A well 
mixed boundary layer along with the subsidence will lead to breezy 
to even gusty wind by late morning and into the afternoon. A few 
gusts over 30 mph will be possible. High temperatures today will 
range from the low to mid 70s north to the upper 70s south.

High pressure will ridge into Iowa on Wednesday leading to a 
pleasant late August day with high temperatures similar to slightly 
warmer than today. The wind will be breezy once again with a few 
gusts over 20 mph possible. Warm advection will return Wednesday 
night as the area of high pressure moves to the east. There will be 
limited moisture arriving with the return flow and be mostly 
concentrated in a shallow layer near 800-750 mb. The lack of 
moisture should limit and convective development. Thursday will be 
warmer with highs in the low to mid 80s. A boundary will reach 
northern Iowa by the afternoon.  Much of the area does appear to 
remain capped with the boundary passage. The CIN does erode more 
over central and southern Iowa. At this time, any thunderstorm 
chances look to be relegated to far southern Iowa and into portions 
of Nebraska and Missouri along the boundary as it stalls. 

Friday and into the Labor Day weekend will feature a subtropical 
high gradually building into the Four Corners region with a short 
wave dropping into the Midwest Friday night into Saturday while the 
boundary just south remains in the vicinity. This will bring shower 
and thunderstorm chances to the region. The ECMWF remains quite 
aggressive with the precipitation with a continuous feed from the gulf 
lifting over the surface boundary and into central Iowa. Currently 
have high temperatures in the upper 60s to low 70s for Saturday.  If 
clouds and precipitation do persist much of the day, the high 
temperatures may be 5 to 8 degrees too warm.  Mostly dry conditions 
return for the remainder of the holiday weekend with highs in the 
70s, maybe low 80s south by Monday.

&&

.AVIATION.../For the 06Z TAFS through 06Z Tuesday night/
Issued at 1209 AM CDT Tue Aug 27 2019

A few patches of fog early ahead of a weak boundary moving east
across Iowa, otherwise VFR conditions are expected through the
forecast period. Breezy to gusty west wind is expected by mid
morning Tuesday before diminishing around sunset. Some cumulus
possible during the day at or above 5 kft.

&&

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

$$

DISCUSSION...Donavon
AVIATION...Donavon