Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 132339

Area Forecast Discussion
National Weather Service Des Moines IA
630 PM CDT Tue Mar 13 2018

.SHORT TERM.../Tonight through Wednesday/
Issued at 340 PM CDT Tue Mar 13 2018

Large surface high pressure to continue to build into the state
tonight but only to quickly shift east during the day Wednesday.
Return flow looks to develop prior to 12z Wednesday, albeit weak,
but should be enough to keep temperatures from dropping past 08z
and have mentioned a non-diurnal temperature trend. Certainly
with the high looking to center itself over the state this
evening, temperatures will quickly drop after sunset.

Mixing quickly increases throughout the morning tomorrow across
much of the forecast area as the surface high pressure shifts
east. Nudged up winds past 15z Wednesday into the afternoon as
mixing to at least 900mb and likely even higher further south.
Winds atop the mixed layer increase to 30-35 knots over the
southern half of the CWA by the afternoon. Mixing completely dry
adiabatically, high confidence much of these winds will reach the
surface. Plus with the west to southwest nature of the winds,
downslope effect will help put maximum temperatures well into the
lower 60s over the southern two-thirds of the CWA. Mixing is not
as significant further north as it will have to contend with a
decent inversion and some light snow pack. However, confident
enough raise temperatures roughly 3-4 degrees with some mixing and
plenty of March sunshine.

Also with the warmer temperatures and slightly stronger winds,
dew points remain dry through the day Wednesday and there is a
fire weather concern for Wednesday afternoon. Fuels are certainly
100 percent cured, even though some areas might still remain soggy
in places, brush or prescribed burns may quickly spread under the
weather conditions.

.LONG TERM.../Wednesday night through Tuesday/
Issued at 340 PM CDT Tue Mar 13 2018

Weak cool front moves through the state Wednesday night and provides
slightly cooler but still near normal day across the forecast area
Thursday. A slow moving low pressure out of Colorado will push
across Kansas and into Missouri late Thursday night into Saturday
morning. The main time period of concern with this system looks to
be Friday morning (12-18z) with the precipitation onset as a wintry
mix.  However, there is plenty of dry air to contend with and the
best forcing arrives later Friday afternoon and evening as the
surface low pushes into eastern Kansas. Low confidence with much QPF
and thus any ice/snow amounts across the southwest. Potentially a
brief period where the precipitation may cause some travel concerns,
but temperatures are forecast to warm above freezing with the bulk
of the forcing moving across by the afternoon. When the system pulls
east by Friday night into Saturday morning, the rain is expected to
switch over to snow during this period. Temperatures quickly
rebound Saturday back into the 40s and any snow accumulation will
rapidly melt later in the day.


.AVIATION.../For the 00Z TAFS through 00Z Wednesday evening/
Issued at 630 PM CDT Tue Mar 13 2018

VFR conditions will prevail throughout the forecast period.  Winds
will again increase in the morning and soundings indicated that
winds near a cold front across northern TAF locations will increase
off the surface to near 40kts.  Thus LLWS was added to KFOD and





SHORT TERM...Podrazik
LONG TERM...Podrazik
AVIATION...FAB is the U.S. government's official web portal to all federal, state and local government web resources and services.