Area Forecast Discussion
Issued by NWS Quad Cities, IA IL
FXUS63 KDVN 232215 AAA
Area Forecast Discussion...UPDATED
National Weather Service Quad Cities IA IL
515 PM CDT THU JUN 23 2016
Issued at 307 PM CDT Thu Jun 23 2016
18z surface data has a subtle boundary roughly along the Mississippi
river with a more pronounced boundary/front from northern Indiana
back into western Wisconsin. Dew points were in the 40s and 50s
across the Great Lakes into the northern Plains. Dew points were in
the 60s and 70s from the mid Mississippi and Ohio Valleys to the
.SHORT TERM...(THIS EVENING THROUGH Friday)
ISSUED AT 307 PM CDT Thu Jun 23 2016
Quiet and slightly less humid conditions will be seen across the
area through late afternoon and the evening hours.
Later tonight and into early Thursday, light winds should allow
patchy fog to develop across the area. It is possible that the fog
could become more widespread or even dense prior to sunrise Thursday.
Potential negatives for for development would be low clouds rotating
into the area from Wisconsin. If the low clouds rotate into the area
that would limit the potential for fog development. Another
potential negative is that dew points will slowly be dropping during
the night as well which may also limit fog development.
On Friday, quiet and dry conditions will be seen across the area.
Cloud cover will dictate how warm it gets but it appears that
temperatures should be close to normal.
.LONG TERM...(Friday NIGHT THROUGH Thursday)
ISSUED AT 307 PM CDT Thu Jun 23 2016
Forecast focus on chance of thunderstorms and very warm this weekend
then temperatures trending a bit below normal next week.
Friday night through Sunday: We will have chance pops for most of
this period with likely pops Saturday night as a weak cold front
arrives. The GFS seems to be too aggressive with qpf and coverage of
storms considering the better forcing and deep layer shear is well
to our north, as the low pressure system will be north of MN. The
severe weather threat appears low at this time. This will be a warm
weekend with highs well into the 80s to lower 90s and dewpoints
pushing into the lower 70s.
Next week: a major pattern change to cooler temperatures expected as
a deep trough takes shape in the east with ridging in the Rockies.
This will send a stronger cold front into the cwa early next week
with a northwest flow aloft being established over the area for at
least the next 7-10 days. Low confidence in rain chances as to
timing of location of any mcs`s that can ride southeast in the flow.
The ECMWF suggests this activity to remain to our south while the
GFS grazes our southern cwa. Time will tell. For now the consensus
models will indicate a chance of thunderstorms about mid-week but
this is heavily weighted towards the GFS which may be bringing too
much moisture northward.
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1234 PM CDT Thu Jun 23 2016
VFR conditions across eastern Iowa and most of northern Illinois
will continue through 00z/24. MVFR clouds across northern Iowa and
Minnesota/Wisconsin are not being handled very well by the models.
Based on the overall flow, these clouds will probably move into
eastern Iowa and the remainder of northern Illinois after 00z/24.
Thus after 00z/24 conditions will slowly deteriorate to MVFR. If
fog develops, which is suggested by the models, then IFR/LIFR
conditions may be possible before sunrise Friday.
Issued at 509 PM CDT Thu Jun 23 2016
Flood watch continues for the lower portions of the Iowa River due
to uncertainty in additional flows. Gage readings are indicating
the river is nearing the crest at both Wapello and Oakville
currently, rather than continuing to rise as was forecast. To
reach these levels would need near another 1000 cfs and that
happening remains uncertain, especially due to the current trends.
There is still a lot of water coming out of the Cedar River as
Conesville (CNEI4) remains above flood stage, but when this water
reaches WAPI4 and OKVI4 areas is important. Will be coordinating
with the NCRFC in the next few hours, but pending timing of
additional flows from upstream reaching this part of the river
in the next 6 hours, the flood watch will likely be cancelled with
no need for a flood warning.