530
FXUS63 KDMX 131900
AFDDMX

Area Forecast Discussion
National Weather Service Des Moines IA
200 PM CDT Mon May 13 2024

.KEY MESSAGES...

- Showers and thunderstorms across central and southern Iowa
  this afternoon and evening, lingering Tuesday morning in
  southeast Iowa. Severe chances are very low.

- Smoke from wildfires in Canada has filtered south into the
  area with impacts into Tuesday.

- Additional showers and thunderstorms later Wednesday into
  Thursday. Severe risk is low at this time.

&&

.DISCUSSION...
Issued at 150 PM CDT Mon May 13 2024

Scattered showers and a few thunderstorms have persisted off and on
today, becoming more persistent in southwest Iowa this afternoon as
the primary forcing near the surface low lifts nearer to Iowa. This
shield of precipitation will continue across central and southern
Iowa through the overnight, tapering off towards southeast Iowa
by Tuesday morning as the low departs to the east. With little
in the way of shear and fairly modest instability the severe
threat remains quite low. Additional QPF of 1-1.5 inches is
possible with this slow moving system. Even so, with low rain
rates and recovering river levels, hydrologic problems are not
anticipated.

Tuesday with feature a lull in activity ahead of the next
system. Primary impacts on Tuesday will be smoke filtering south
into Iowa from wildfires burning in central Iowa. Additional
information on air quality in Iowa can be found through the Iowa
DNR. By Wednesday a long wave trough will shift into the
central US. Embedded within the wave is a southern and northern
stream. Recent model runs have hinted that the streams will not
quite phase, resulting in less forcing across Iowa with a low
moving both north and south of the area. The Euro and GFS split
some in how to handle Iowa in between. For now the GFS favors a
slower phasing that occurs east of Iowa, resulting in less rain
while the Euro is a little faster with more rain. In both cases
severe impacts are low into the area with primary forcing
mechanisms outside the area.

Models continue to indicate another shortwave passing across the
area this weekend, however there are still rather substantial
differences in timing between the GFS/Euro suites. These would have
notable impacts to both precipitation and on temperatures. Recent
NBM runs have favored warm solutions into the weekend which are most
prevalent within in the Euro suite, however some GFS member have
trended this way as well. Additional detail will be available in the
coming days.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1243 PM CDT Mon May 13 2024

Showers with a few embedded thunderstorms are moving across the
area with primary impacts at KDSM/KOTM with ceilings near or at
MVFR. These showers will linger through the evening before
tapering off into Tuesday morning. On Tuesday morning further
ceiling reductions to IFR are possible. At the same time,
northern sites have seen haze impacting visibility as smoke from
Canadian wildfires filters south. Have timed this out to
diminish through the overnight, however models suggest a second
wave may move through on Tuesday which may prolong impacts.
Adjustments will be made in future issuances.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Hagenhoff
AVIATION...Hagenhoff