Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 240813
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
313 AM CDT Sat Aug 24 2019

.SYNOPSIS...
Issued at 232 AM CDT Sat Aug 24 2019

High pressure is centered over southern Ontario and the northern
Great Lakes this morning. There are easterly winds around 5 MPH
across the area. Cirrus were moving into eastern Iowa and far
northeast Missouri from thunderstorms across the High Plains. At 3
AM, temperatures ranged from 50 degrees at Freeport to 62 degrees
at Iowa City. Dewpoints were in the lower to mid 60s.

&&

.SHORT TERM...(Today and Tonight)
ISSUED AT 232 AM CDT Sat Aug 24 2019

Models are in good overall agreement on the overall pattern. The
main forecast concern will be temperatures.

The 500 mb ridge axis will shift from over eastern Iowa this
morning into Michigan by 12 UTC Sunday as a 500 MB trough
approaches the area. At the surface, the center of surface high
pressure moves into the Canadian Maritimes but anticyclonic flow
around the surface high will remain in place across the area with
dry easterly flow. There is very little change in 850 MB
temperatures over the next 24 hours and thus the forecast was
adjusted upward from a couple of degrees from the guidance since
it has been running cool the last two days.

Low temperatures on Sunday morning are expected to be a couple of
degrees warmer than today with increasing cloudiness and some
warmer air and moisture being advected into the region.

.LONG TERM...(Sunday through Friday)
ISSUED AT 232 AM CDT Sat Aug 24 2019

The pleasant and dry weekend looks to continue through Sunday, as
models have backed off on low level moisture advection. The moisture
at mid levels, seems to lack much forcing, and thus, I think we`re
mainly talking about mid clouds arriving during the day Sunday,
rather than rain and storms. This is mainly true again for Sunday
night, as the wave to the south offers little forcing, and dry low
levels will only be moistening to dewpoints in the 60s by Monday mid
morning, as low level flow increases from the south ahead of the
approaching cold front. That cold front will move through Monday
afternoon through Monday night, and offers our most significant threat
for rainfall this week. The timing is now favorable for a storms to
produce a bit better coverage, as it`s rolling through during the
early evening hours. If so, the atmosphere is moist enough for at
least a few stripes of rainfall approaching 1 inch. For now, will
cap pops at likely levels, but this could be a solid band of
rain/storms as it moves through. Mid level winds may also support a
wind threat with the storms, but confidence isn`t high right now, as
this front`s timing is just now gaining confidence.

Tuesday through Thursday, a dry period is expected, and we have
removed the model blend pops for those periods.  It looks like
diurnal cumulus is likely in these days, but a lack of any moisture
or trigger should keep rain chances out of the picture. A more
robust wave arrives toward Thursday night and Friday, which is going
to carry a thunderstorm threat, as much cooler air is spreading
south over the Midwest. Behind that front, highs in the lower 70s
with a breeze are expected. Rather Fall-like conditions may be in
place for much of the Labor Day weekend.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
ISSUED AT 1239 AM CDT Sat Aug 24 2019

High pressure will continue to bring VFR conditions to eastern
Iowa TAF sites through the period.


&&

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

$$

SYNOPSIS...Cousins
SHORT TERM...Cousins
LONG TERM...Ervin
AVIATION...Cousins


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