FXUS63 KDMX 300959

Area Forecast Discussion
National Weather Service Des Moines IA
359 AM CST Wed Nov 30 2022

.DISCUSSION.../Today through Tuesday/
Issued at 358 AM CST Wed Nov 30 2022

Key Messages:

- Breezy and colder today.
- Windy Thursday and again late Friday and Friday night. Wind
  headlines may be needed.

The low pressure system that impacted Iowa on Tuesday, is now well
to the northeast into Ontario. Central Iowa will remain in the
cyclonic flow associated with that low for much of today which will
feature brisk west/northwest winds. A moderate pressure gradient
along with mixed layer winds in the low 30 kt range and continued
cold advection will keep the wind in the breezy/windy category. A
broad area of stratus is along and north of the IA/MN border this
morning. The steering level winds for this stratus maintain a
trajectory around 290 degrees which would drop this stratus into the
far northeast near Mason City and possibly to Waterloo before
eroding. There have been a few flurries reported with the stratus in
Minnesota but have not added any flurries to the forecast yet as the
moisture depth is shallow. Today will be on the cold side with highs
in the low 20s north to low 30s south with wind chill values in the
single digits to teens.

Ridge of high pressure will move into southwest Iowa late this
afternoon and move across the area tonight. This will help drop
temperatures in the single digits north to teens elsewhere, though
weak warm advection will develop once the ridge passes to the east
so that will limit the potential for lows to bottom out along with
increasing clouds due to massive warm advection aloft. A strong
pressure gradient will develop over Iowa again on Thursday as the
ridge passes to the east while low pressure deepens to the west.
Mixed layer winds in the upper 30s to low 40s kt range will be
present during the afternoon. Warm advection will dampen the mixing
efficiency but still it will be a windy day that could warrant
headline consideration. Mixing will be limited to near 900-875 mb by
an inversion aloft so the full extent of the warm advection will not
be realized at the surface temperature wise.

The warm advection will persist into Friday but increasing stratus
may contain high temperatures. Another strong boundary will reach
western Iowa during the afternoon and sweep across the state Friday
night. A strong pressure gradient will again setup along with mixed
layer winds in the 45-50 kt range. This time though, subsidence
aloft in the wake of the passing short wave and cold advection will
maximize the mixing of the stronger winds to the surface.The
pressure height rise is impressive as well. This period looks like
the potential for wind headlines is high. Some light wintry
precipitation could clip the far north with the boundary passage.
Saturday will be colder but the wind will be much lighter as high
pressure arrives. Sunday and Monday look quiet at this point. There
still remains a lot of noise in the forecast for mid next week with
several upper low fragments rotating though Canada which makes that
period a low confidence forecast.


.AVIATION.../For the 06Z TAFS through 06Z Wednesday night/
Issued at 1126 PM CST Tue Nov 29 2022

Precipitation has tapered off this evening with skies quickly
clearing out. VFR conditions are expected to persist through the
period with continued gusts over 25 kts out of the west northwest.





NWS DMX Office Area Forecast Discussion