Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 251208
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
608 AM CST Sat Feb 25 2017

.UPDATE...
Issued at 607 AM CST Sat Feb 25 2017

Model guidance too slow in the clearing line, which has already
progressed to the MS River. In the meantime, the western edge of
the scattered very light snow or flurries was in our far eastern
counties and continued to push off to the east. Have updated the
grids to bring in the clear skies much sooner than earlier thought.

&&

.SYNOPSIS...
Issued at 325 AM CST Sat Feb 25 2017

Upper level trough was swinging across the area with the stronger
forcing beginning to shift off to our east. The snow was diminishing
in intensity and coverage to only very light snow or flurries.
Subsidence in the wake of the trough has already ended the snow in
our western counties, and was also clearing out the skies.

Northwest winds were gusting up to 30 mph across the dvn cwa and
temperatures were in the 20s.

&&

.SHORT TERM...(Today and Tonight)
ISSUED AT 325 AM CST Sat Feb 25 2017

Forecast focus on a brisk and chilly day.

Today: Upper level trough/forcing will continue to shift eastward
allowing for any lingering light snow or flurries to end early
this morning. Skies should become sunny from west to east as the
day progresses. In addition, brisk northwest winds will also
gradually diminish this afternoon, as high pressure pushes into
MO. This will be a chilly day with maximum temperatures ranging
from the upper 20s north to the mid 30s south. Wind chills this
morning will be in the single digits.

Tonight: High pressure ridge moves east returning warm air
advection mid/high level clouds, so skies will become mostly
cloudy again. Winds will turn southerly and temperatures may
actually start rising later tonight. Lows will be in the lower to
mid 20s, and in many locations this will occur this evening.

.LONG TERM...(Sunday through Friday)
ISSUED AT 325 AM CST Sat Feb 25 2017

A return to a zonal upper level flow will result in moderating
temperatures Sunday into the early part of the week. The next
significant chance for precipitation arrives Monday night into
Tuesday with a system that marks the transition to a northwest flow
aloft and a change back to normal to slightly above normal
temperatures for the end of the week.

Sunday into Monday will feature a low level warm advection regime
with a weak upper level system passing to the south no longer
supporting any precipitation in the forecast area. Temperatures
return to the 40s and possibly lower 50s south by Monday.

Tuesday looks like the warmest day of the week with highs in the 50s
to near 60 as a deepening low level warm advection process
strengthens ahead of surface low pressure and an upper level trough
that push through Tuesday night. With widespread clouds and at least
light precipitation, advertised highs may be on the warm side for
Tuesday, unless a more northwesterly track occurs, pushing a more
deeply mixed warm sector into the area. Precipitation breaks out
Monday night in the developing warm air advection ahead of this
system and then increases and becomes focused mainly across the
north late Monday night. Low level thermal profiles point toward
mainly rain, even in the overnight period as wet bulbs rise rise
above 32 and the layer above zero Celsius deepens to above the 850
mb level and spreads north of the highway 20 corridor by midnight.

Cooler temperatures follow for Wednesday through Friday with a
chance for precipitation in the form rain or snow as system passes
along the frontal boundary to the south Wednesday. The GFS is the a
more bullish outlier with a system in the Great Lakes sweeping a
front through with resulting very low pops with possible
for rain or snow late Thursday.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
ISSUED AT 607 AM CST Sat Feb 25 2017

VFR conds through this taf cycle. SKC today will give way to
increasing mid/high level clouds tonight. Northwest winds 15 to 25
knots today then diminishing late this afternoon and backing west
to southwest less than 10 knots tonight.

&&

.HYDROLOGY...
Issued at 325 AM CST Sat Feb 25 2017

With the winter storm system exiting the area this morning,
precipitation has now largely been accounted for in the river
forecasts. Rises continue along the Iowa tributaries, with forecasts
calling for minor flooding at Conesville, where a flood warning
remains in effect for minor flooding beginning Sunday afternoon.
Several other sites are expected to rise to action stage over the
next several days.

On the Mississippi River, recent rainfall and routed flow is
forecast to result in steady rises over the next week and beyond at
all sites. The latest forecasts have minor flooding occurring
roughly 7 to 8 days out at Dubuque, Keithsburg, Gladstone and
Burlington. With low confidence that far out in time and the
anticipation of further adjustments to these forecasts, no watches
or warnings are in place.

&&

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

$$

UPDATE...Haase
SYNOPSIS...Haase
SHORT TERM...Haase
LONG TERM...Sheets
AVIATION...Haase
HYDROLOGY...Sheets


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