Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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935
FXUS63 KDVN 212051
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
251 PM CST Tue Feb 21 2017

.SYNOPSIS...
Issued at 248 PM CST Tue Feb 21 2017

18Z surface data has a cold front running from eastern lower
Michigan into northwest Arkansas. High pressure ran from the western
Great Lakes into the southern Plains. Dew points were in the 50s
from lower Michigan into Arkansas with 30s and 40s from the Plains
into the western Great Lakes.

&&

.SHORT TERM...(This Evening through Wednesday)
ISSUED AT 248 PM CST Tue Feb 21 2017

Near record to record warmth will continue for one more day across
the entire area. ALL-TIME record highs for February may be
challenged Wednesday. Refer to the climate section for specific
information.

Mainly quiet and dry conditions will be seen from late this
afternoon through Wednesday. Temperatures will continue to average
well above normal.

Patchy fog is possible tonight and Wednesday morning. Areas east of
the Mississippi are most favored for fog development. However, parts
of the Wapsi and Cedar river valleys may also see some patchy fog.

.LONG TERM...(Wednesday Night through Tuesday)
ISSUED AT 248 PM CST Tue Feb 21 2017

Forecast focus in the extended is on precipitation chances Thursday
afternoon-Friday with a return to near seasonable or even slightly
below normal temperatures Saturday and Sunday. After a record
breaking week, it will feel much colder this weekend. Active weather
pattern continues through early week.

Wednesday night-Friday...strong cyclogenesis takes place on lee side
of Colorado rockies and begins to move out into the Plains. There
still remains a lot of uncertainty in the track and timing of
this low. The latest 12z NAM is the outlier and is much more
progressive with the low than other solutions, whereas the 12z
GFS/ECMWF are slower and further to the west. The GFS Ensembles
are in general agreement around its mean and thus I believe the
low will follow a slower solution such as the GFS/ECMWF which will
bring it from Kansas, to northwest Missouri, to somewhere between
ALO and CID by 15z Friday. In any case, the track of low and how
far north the subsequent warm front lifts, will be critical in how
warm it will be on Friday, especially west of the MS RVR. I do
believe the latest solutions gives me confidence that the thermal
fields will be warm enough to support all rain in the entire CWA
Thursday and Thursday night.

Overrunning rain will lift north ahead of the warm front Thursday
afternoon and evening. PWATs approaching 1 inch or 250% of normal
will support rain amounts between a quarter to three quarters of an
inch by 00z Saturday. Forcing and low level convergence fields
suggest that the heavier amounts will be north of I-80. A few
thunderstorms will be seen as well as 700-500 mb theta-e lapse rates
go negative Thursday evening. Strong 50 kt LLJ and minimal CAPE
values near 500 J/Kg may support some strong storms capable of
producing small hail.

Friday afternoon-Saturday...surface low and warm front begins to
lift northeast into Wisconsin with scattered showers tracking north
and east out of the CWA. A noticeable dry slot/strong subsidence
will push over the region Friday allowing some clearing to take
place. Mild air ahead of the cold front, will push temperatures up
into the 50s and lower 60s for most Friday. The cold front
associated with the low will be east of the CWA by 00z Sat, with
strong CAA and strong west northwest winds. Any wrap around
precipitation will quickly switch over to snow Friday night and
Saturday, especially north of highway 30. Snow accumulation is
expected to be minimal and mainly on elevated surfaces. Highs
Saturday will be in the lower to middle 30s, which will be a few
degrees below normal. Definitely a change to what we have been
experiencing lately.

Looking further ahead...pattern change to more of a northwest flow
expected through early next week. The latest model runs continue to
show a light precipitation event Sunday, although they have come in
slightly drier than in previous runs. Thermal fields would support
some light snow somewhere in the CWA with the 12z GFS favoring the
south half and the ECMWF the north. Another system will impact the
area Monday night-Tuesday morning and with varying solutions will
keep chance PoPs going for now.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
ISSUED AT 1118 AM CST Tue Feb 21 2017

VFR conditions should be seen through 00z/23 as high pressure
moves into the Great Lakes. The models are suggesting some MVFR
conditions with fog developing tonight due to the light winds and
relatively damp ground. The models appear to be overdone on the
low level moisture. If fog develops tonight, it would be very
patchy in nature and may or may not affect a TAF site.


&&

.CLIMATE...
ISSUED AT 248 PM CST Tue Feb 21 2017

Record highs for February 21st...

Burlington........68 in 1983
Cedar Rapids......68 in 1930
Dubuque...........63 in 1930
Moline............66 in 1930

Record highs for February 22nd...

Burlington........66 in 2000 and previous years
Cedar Rapids......64 in 1984
Dubuque...........61 in 1984
Moline............66 in 1922

ALL-TIME record highs for February...

Burlington........76 on 02/24/1930
Cedar Rapids......73 on 02/15/1921
Dubuque...........68 on 02/15/1921
Moline............73# on 02/15/1921

#The ALL-TIME record high for February at Moline was reset to 74 on
02/19/2017 and may get reset again on Wednesday.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SYNOPSIS...08
SHORT TERM...08
LONG TERM...Gross
AVIATION...08
CLIMATE...08



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