Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 182006
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
306 PM CDT Sat Mar 18 2017

.SYNOPSIS...
Issued at 304 PM CDT Sat Mar 18 2017

Northwest flow continues at the surface with a high pressure ridge
now pushing into western Iowa. The result for today, has been breezy
conditions, and a slow erosion of the stratus over Iowa and
Illinois.

&&

.SHORT TERM...(This Evening through Sunday)
ISSUED AT 304 PM CDT Sat Mar 18 2017

Today has shown a challenging squeeze play of slow clearing from
west to east, combined with thinning from north to south. The result
is a narrow NW-SE band of broken stratocumulus from around Charles
City, to the Quad Cities, to Champagne Illinois. the mixing has been
increasing through the day, resulting in highs still topping out in
the mid to upper 40s in most spots through 2 pm, and some lower 50s
in the full sun in the south. Tonight, the clearing trends will
complete, and clear skies should be found area wide this evening,
before some mid clouds approach late. This will se the stage for a
good radiational cooling night with the surface ridge providing
light winds. Lows in the mid to upper 20s in the northeast 1/2,
while increasing southeast winds in southern sections help keep lows
closer to freezing. In any case, a heavy frost seems likely, and
some valley fog may need to be considered if the clear skies linger
through sunrise.

Sunday, warm advection through the day should bring highs easily
back to the 50s, and could yield some lower 60s south if we see
afternoon sun. Forcing for rain looks to hold off until evening, so
for all locations, Sunday should be seen as a very pleasant, though
somewhat breezy day.

ERVIN

.LONG TERM...(Sunday Night through Saturday)
ISSUED AT 304 PM CDT Sat Mar 18 2017

Active pattern continues through the next week.  As is typical
during the transition seasons, noticeable model differences
exist.

Initial concern is chance for storms Sunday night ahead of the
advancing cold front. Low level jet is progged to increase to 30+
kts overnight.  This, combined with elevated instability, would
support potential for storms.  Given the elevated nature of these
storms, hail would be the main threat.  SPC does keep roughly the
southern half of the area in a marginal risk for severe storms in
the day 2 outlook.

The remainder of the week, a chance for rain exists for much of the
area Tuesday as a weak short wave passes by.

Then Thursday into Friday, widespread rain and thunderstorms are
likely as a stronger system organizes and tracks across Iowa. GFS
solution is a bit of an outlier in this period, coming in faster,
stronger, and farther north than the slower Canadian and ECMWF. Have
discarded the GFS for these periods as this seems unlikely.

Could see light snow or a rain/snow mix as precipitation begins
Thursday morning.  However, this would be short-lived as warm
advection takes over quickly during the morning.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
ISSUED AT 1235 PM CDT Sat Mar 18 2017

MVFR stratus has been over the upper Midwest since last night, and
it now in a thinning process. This process will continue through
sunset today, and should eventually result in all sites becoming
VFR by mid afternoon. Winds will decrease through the afternoon
from the northwest and switch to light east by tonight.

ERVIN


&&

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

$$

SYNOPSIS...Ervin
SHORT TERM...Ervin
LONG TERM...DMD
AVIATION...Ervin



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