Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 211717

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1217 PM CDT Sat Apr 21 2018


Issued at 309 AM CDT Sat Apr 21 2018

High overcast is found over Iowa and Illinois, as the upper level
low continues to spin near Colorado. This upper low is moving very
slow, if at all early today. The high cloud cover has helped keep
our area in the upper 30s to mid 40s.


.SHORT TERM...(Today and Tonight)
ISSUED AT 309 AM CDT Sat Apr 21 2018

Today`s weather will be dominated by mid and high cloud cover, but
otherwise will be very tranquil and mild. Filtered sunshine through
high clouds today will have our forecast staying very close to the
guidance blend today, rather than going above guidance.  We will get
a milder start today, so there`s no strong reason to undercut
guidance highs, which are mid 50s north to lower 60s south. The high
pressure to the east will bring light east winds over the north
half, and in a slightly stronger gradient in the south, 10 to 15 mph
winds there.  In any case, this is by far the most pleasant Saturday
we`ve had in many weeks. Tonight, with the slow moving weather
pattern, expect a night nearly identical to the one outside now.
Lows in the mid 30s northeast to lower 40s south will be seen under
high clouds.

.LONG TERM...(Sunday through Friday)
ISSUED AT 309 AM CDT Sat Apr 21 2018

Cut off H5 low will lumber across the southern CONUS through the
beginning of the period.  This will lead to a pseudo High over Low
blocking pattern.  This will result in a warming trend across the
area with quiet weather through the beginning of next week.  The
main forecast concern through this period will be how warm
temperatures will be.  Guidance temperatures will likely be low,
especially with high temperatures.  Expect temps to be a couple of
degrees warmer than what is currently forecast.

Into next week, a clipper is forecast to dive south in the central
CONUS.  Guidance is consistent with the H5 flow and overall momentum
fields.  However there are differences in placement of the forcing.
As a result there are differences in sensible weather.  The GFS
brings a surface low and precip to the area.  Whereas as ECMWF and
GEM do not have any precip.  As a result, the blend has schc to
chance pops.  With this wave moving through the central CONUS,
decided to leave the pops in.  That said,  this will be an area that
later forecasts can look at improving.  Overall, spring will remain
through the extended period.


.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
ISSUED AT 1215 PM CDT Sat Apr 21 2018

Mostly cloudy of mid and high clouds to prevail for the next 24 hours
as disturbance passes to our south. Otherwise, VFR conditions to dominate
with winds generally easterly at 5 to 15 mph.





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