Area Forecast Discussion
Issued by NWS Des Moines, IA

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FXUS63 KDMX 230448

Area Forecast Discussion
National Weather Service Des Moines IA
1148 PM CDT Wed Mar 22 2017

.SHORT TERM.../Tonight through Thursday/
Issued at 354 PM CDT Wed Mar 22 2017

Surface high pressure continues to press eastward tonight and the
pressure gradient increases b/t 00-12z Thursday. Thus, south to
southeast winds look to increase overnight tonight into tomorrow
with the strongest gusts likely during the day tomorrow as a good
push of WAA develops. Regarding the WAA, increased MAX Temps
tomorrow as a dry slot punches northward out of Missouri by the
afternoon hours. Thus, some breaks in the precip and cloud cover
and confident enough to nudge temperatures up 2-5 degrees over the
central to southwest and potenitial still too cool if sky clears
out sooner. A decent slug of mid-level Theta-E advection rides the
southwest flow aloft ahead of the deep trough digging into the
Rockies from 12-18z Thursday. Precip looks to move from southwest
to northeast during this time frame. There is a very brief period
for FZRA across the northeast tomorrow morning, but with the
strong WAA, surface temperatures should quickly warm above
freezing resulting in little impact. Have a break in the pops
across the south by the afternoon to coincide with the
aforementioned dry slot.

.LONG TERM.../Thursday night through Wednesday/
Issued at 354 PM CDT Wed Mar 22 2017

The deep trough continues to slowly move eastward across the
Rockies into the High Plains Thursday night into Saturday and
transitions into more of a cutoff upper low by Friday
afternoon/evening. This cutoff low slowly churns over the region
and brings persistent Gulf moisture into the state Friday into
Saturday. High confidence in a long duration rain event beginning
late Friday morning and finally tapering off late Saturday
afternoon. Precipitable water values range in the 1 to 1.25 inches
which is at or above the maximum for this time of year wrt to
climatology. These precipitable water values persist across the
state from Friday morning into Saturday morning before decreasing
from west to east across the state past 09z Saturday. Warm layer
cloud depths range in the 9000-10000 foot range Friday into Friday
night, so certainly some locally heavy rain possible at times.

Sunday into Tuesday...a quick moving upper level shortwave skirts
across Kansas into Missouri Sunday night into Monday. Precip chances
remain across the far south attm.  Otherwise, the ECMWF suggests
another cutoff low to enter the Plains by mid-week and provide rain
chances to the state Tuesday night into Thursday.  However, trended
drier Monday night into Tuesday with the strong surface high in
place holding of the eastward movement of the aforementioned low.
Likely to need to adjust pops drier Tuesday into Wednesday to go
along with the dry GFS solution.


.AVIATION.../For the 06Z TAFS through 06Z Thursday night/
Issued at 1145 PM CDT Wed Mar 22 2017

VFR ceilings are expected overnight but lower ceilings will arrive
on Thursday morning as moisture surges back into Iowa. Some
scattered light rainfall is expected with MVFR conditions becoming
more widespread in northern Iowa during the day. However, warm
sector will overspread the area by later in the day with ceilings
climbing once again, especially in the southern half of the
forecast area. Strong southeast surface winds will be common for
the duration of the forecast.





SHORT TERM...Podrazik
LONG TERM...Podrazik
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