Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 061737
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1137 AM CST Wed Dec 6 2017

...AVIATION UPDATE...

.SYNOPSIS...
Issued at 307 AM CST Wed Dec 6 2017

Weak upper level disturbance that brought some flurries to
portions of the cwa earlier in the night has already quickly
pushed east of the dvn cwa. Skies were clearing in the wake of
this system.

Early morning temperatures ranged from the mid 20s to mid 30s.

&&

.SHORT TERM...(Today and Tonight)
ISSUED AT 307 AM CST Wed Dec 6 2017

Forecast focus on mainly flurries with a series of weak upper
level disturbances in the northwest to north flow.

Today: A weak wave currently in the Dakotas will push southeast
into our far southern cwa this afternoon. I will follow the HRRR
and NAMNEST which indicates some flurries or possibly some
sprinkles there. The remainder of the cwa should remain dry today.
Northwest winds will gust up to 30 mph but certainly nothing like
we have experienced the past couple of days. Maximum temperatures
will range from the upper 20s along Highway 20 to near 40 in
extreme northeast Missouri.

Tonight: Another weak wave may produce some flurries over portions
of the cwa (mainly the north and east) mainly after midnight. Lows
will be in the teens over much of the cwa. However, with northwest
winds of 10 to 15 mph wind chills will dip into the single digits.

.LONG TERM...(Thursday through Tuesday)
ISSUED AT 307 AM CST Wed Dec 6 2017

The long term will once again be dominated by northwest to northerly
flow, and winter-like temperatures. This flow will undoubtedly
contain passing waves that will bring light snow or flurries to the
region, but models offer virtually no run to run consistency on the
track and timing of these systems. So, that leaves us in a situation
where we could say "chance of snow" every day, thus implying a
stormy, and possibly inadvertently hazardous week ahead. That just
doesn`t seem to grasp what in reality should be a dry week, possibly
with some flurries, and a very low chance for an extremely small snow
total (less than 1/2inch) somewhere in the nearby region. I would
rather keep the forecast as dry as possible, to indicate the vastly
more likely situation for good dry travel conditions, and deal with a
flurry here and there as we see those passing upper waves in the
shorter term of the forecast. Our model blended pops are reasonable
in my opinion, and focus low pops for snow in the northeastern
counties Friday night, and again toward next Tue/Wed.  Both of those
pop forecasts are in the warm advection band ahead of a system, and
are currently expected to pass well to the northeast of Iowa.
That`s typically too far away for any real snow accumulation with a
clipper.

So, our forecast will really focus on temperatures, which are cold,
but with systems passing near to north of Iowa at times this week,
we should see significant warm advection at lower levels too.
Thursday, cold high pressure will be in place, and highs should stay
in the mid to upper 20s, and fall to the mid teens at night, before
Friday`s warm advection draws up the lower to mid 30s over the CWA.
The flow then will with high confidence,  draw the next high down
for Saturday, a cold day in the mid 20s north to lower 30s south.
Flatter flow aloft for Sunday and Monday, ahead of a more
significant upper trof/clipper Monday night will bring more milder
weather again, as highs reach the upper 30s to lower 40s. That
forecast definitely reflects the warm front and any snow well  north
of our CWA.  By Tuesday, brisk cold northwest winds will return with
highs back in the upper 20s to mid 30s.

ERVIN

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
ISSUED AT 1127 AM CST Wed Dec 6 2017

MVFR conditions will be seen at KCID and KBRL through the next
few hours, with improvement to VFF through this evening.
Overnight, conditions will deteriorate to MVFR as a weak wave
moves across the region, with some flurries also possible at KDBQ.
By Thursday morning, expect VFR at all sites.

&&

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

$$

SYNOPSIS...Haase
SHORT TERM...Haase
LONG TERM...Ervin
AVIATION...Speck/Uttech



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