FXUS63 KDMX 152033

Area Forecast Discussion
National Weather Service Des Moines IA
333 PM CDT Mon Oct 15 2018

.DISCUSSION.../Tonight through Monday/
Issued at 331 PM CDT Mon Oct 15 2018

After a patch of stratus and some cumulus development this morning,
skies have become mostly sunny across the state. While temperatures
remain cool in the low to mid 40s over central Iowa, webcams and
satellite imagery have shown that any snow cover from Sunday has
rapidly melted except for a few sheltered areas. A large area of
high pressure over Kansas will settle south tonight allowing warm
advection to develop overnight with west to southwest winds at 5 to
10 mph prevailing. The timing and strength of the warm advection
does make the temperature forecast overnight a bit challenging
especially considering the freeze potential over southeast Iowa. Dew
point temperatures are in the mid to upper 20s and with temperatures
in the 40s, clear skies and diminishing wind this evening,
temperatures should drop quickly this evening before stabilizing
due to the warm advection after midnight. Temperatures should
approach freezing or just below most locations. Due to this and
existing headlines to the east and south, will include a Freeze
Warning for portions of the southeast forecast area for late
tonight into early Tuesday morning. Freeze headlines will no
longer be issued this fall for the remainder of the area due to
temperatures having already reached freezing or below. Expect this
to be the last Freeze Warning for the NWS Des Moines forecast
area this fall.

Temperatures will be warmer on Tuesday with breezy southwest winds
prevailing much of the day with highs in the 50s. A cold front will
reach far northern Iowa late in the day but the impacts of cold
advection are expected to arrive after peak afternoon heating. That
said, gusty west to northwest winds likely will arrive during the
afternoon with the wind shift with gusts of 30 to 35 mph possible
over the northeast including the Mason City area. It is possible
that a few clouds arrive over the northeast during the afternoon as
well as the boundary approaches. Cooler temperatures on Wednesday
with highs in the mid 40s to low 50s along with high pressure
arriving during the day. Warm advection will return once again with
the departure of the high to the east Wednesday night and Thursday.
High temperatures Thursday could reach the low 60s in some locations
and while this seems warm, these temperatures are still near to
below normal for this time of year.

A few showers are possible Thursday night into Friday as an upper
level trough and associated boundary pass across the state. The
weekend will be cooler and dry and certainly an improvement over
this past weekend. Another system will pass across the region Sunday
night and Monday. At this time any precipitation looks to remain
focused east of the area with more dry air remaining across Iowa.


.AVIATION.../For the 18Z TAFS through 18Z Tuesday afternoon/
Issued at 1242 PM CDT Mon Oct 15 2018

VFR conditions are expected throughout the TAF period. The main
concern this afternoon will be gusty west-northwest winds,
particularly impacting DSM/ALO/OTM. A few clouds will linger at
OTM through the afternoon, otherwise expecting clear skies.
Clouds will begin to increase across the area by tomorrow.


Freeze Warning from 1 AM to 9 AM CDT Tuesday for IAZ062-074-075-




NWS DMX Office Area Forecast Discussion