Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 201745

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1245 PM CDT Thu Oct 20 2016

Issued at 1245 PM CDT Thu Oct 20 2016

Upper level trough and low level cold air advection was producing
extensive low clouds across much of the cwa this morning. This has
prevented much of a rise in temperatures, and have updated the
grids this morning to lower maximum temperatures and increase sky
coverage. With the passage of the trough, skies have cleared in
northern IA and this clearing trend will continue to advance
southeast over the dvn cwa during the afternoon/early evening.
Highs will be in the 50s.

With subsidence in the wake of the trough and surface high
pressure building into the cwa, this should set-up much of the cwa
for areas of frost tonight. Will seriously consider a frost
advisory that may be issued this afternoon, especially for much of the
cwa north of Highway 34. Lows should dip into the lower to mid
30s, except upper 30s in our far south.


Issued at 216 AM CDT Thu Oct 20 2016

Upper air analysis shows increasingly amplified flow as energy drops
into the base of the trough over the central US.  Surface analysis
shows high pressure over the northern plains with the surface front
from Chicago to Kansas City.


.SHORT TERM...(Today and Tonight)
ISSUED AT 216 AM CDT Thu Oct 20 2016

Generally quiet weather in the short term.  With the upper trough
over the area today, expect clouds to linger through much of the
day. This, combined with low level cold advection, will result in
much cooler temperatures with highs mainly in the 50s.  Area of
precip over southwest IOwa is progged by short term models to
continue to weaken through the morning and thus will keep forecast
dry for today.

Next potential concern is frost risk tonight.  With clearing
expected this evening and the surface ridge centered to our south,
should easily see 30s tonight.  Only fly in that ointment would be
if the upper trough slows causing clouds to linger well into the
overnight hours.  Temperatures would still hit the 30s but frost
formation could be reduced.  But that potential is low and thus
have included frost in forecast for tonight.

.LONG TERM...(Friday through Wednesday)
ISSUED AT 216 AM CDT Thu Oct 20 2016

Expect dry and cool conditions Friday, with highs in the 50s. Some
patchy frost is possible north late Friday night with lows likely
dipping into the mid 30s. A warming trend will then follow for the
weekend, with highs back above normal by Sunday, in the mid 60s to
low 70s.

Looking ahead to next week, a period of showers and isolated
thunderstorms still looks favored for late Tuesday into Wednesday.
The operational GFS and ECMWF continue to have differences in the
timing and strength of the shortwave trough through this period.
There is potential for precipitable water values well over 1
inch, which is quite moist for late October, and localized heavy
rainfall. The current timing suggests a low threat for severe


.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
ISSUED AT 1245 PM CDT Thu Oct 20 2016

MVFR cigs this afternoon becoming VFR by late afternoon/early
evening. Then VFR with SKC tonight into Friday morning as high
pressure builds into the area from the west. Winds will be
northwest to north 10 to 20 knots this afternoon, then less than
10 knots tonight and Friday.




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