Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 220808
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
308 AM CDT Fri Sep 22 2017

.SYNOPSIS...
Issued at 305 AM CDT Fri Sep 22 2017

A warm front was located across central MN to Lake Superior with a
strong cold front in the eastern Dakotas. A strong low level jet
extended from the central Plains to the Upper MS Valley.
Thunderstorms were firing on the nose of the jet/strong forcing
from extreme northeast SD to northeast MN.

Unbelievably warm for this time of year/night with temperatures
well into the 70s to around 80 across the central/southern Plains
and into MN/WI.

In the dvn cwa, southerly winds were keeping temperatures very
warm for this time of year, along with some patchy cirrus. 2 am
readings were in the 70s.  Haase

&&

.SHORT TERM...(Today and Tonight)
ISSUED AT 305 AM CDT Fri Sep 22 2017

Autumnal equinox arrives at 302 pm today but temperatures will
feel more like the summer solstice instead.

Today: High pressure surface and aloft will provide plenty of
sunshine (patchy cirrus) along with humid conditions. Afternoon
temperatures will soar into the lower 90s at many locations, and a
couple of mid 90s can`t be ruled out, depending on amount of
mixing. 850 mb temperatures will be around 21c which should
support readings in the 90s. With dewpoints around 70 this will
push heat index values into the mid to upper 90s.

While officially not in the heat advisory criteria, this will be
close and the day shift can issue a strongly worded special
weather statement later this morning. The bottom line, today will
feel more like July so use caution if spending time outdoors. See
climate section below for near record highs.

Tonight: Mostly clear with rather light winds should allow minimum
temperatures to bottom out in the upper 60s.  Haase

.LONG TERM...(Saturday through Thursday)
ISSUED AT 305 AM CDT Fri Sep 22 2017

Through the weekend, the heat will continue to be the main story, as
incredibly warm air continues to stream northeast out of the plains
over the upper Midwest. The hottest conditions will be Saturday,
when like today lower to mid 20s at 850mb will enable near record to
record hot highs around 90, with mid day heat index readings of 92
to 96.  Sunday, mid levels will cool off slightly, and with some
high clouds potentially in place, highs in the mid to upper 80s are
forecast.  Nearly identical weather is expected Monday.  The only
real good news in this pattern compared to typical summer heat, is
that we should see a steady 10 mph south wind each day, offering a
bit of relief.

Tuesday, and Wednesday, a weakly forced front will slide through,
and models offer up about 48 hours of low pops that will eventually
be refined to about 12 hours. The situation may result in little if
any rainfall, assuming the GFS and ECMWF are correct, but there is
potential for storms as well, therefore the GEM`s heavier QPF is
possible as the front isn`t much different from what happened last
night.  If a cap can break fully in the right mesoscale convergence,
we could see some isolated decent rains again, but this is far from
certain.

What is certain is that cooler temperatures are on the way, and will
linger through the end of the month. Summer`s heat looks to be gone
for another year with respect to highs in the 90s, as we look as a
long duration of highs in the 60s and 70s ahead with lows in the
40s, which is all very much close to normal.
ERVIN

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
ISSUED AT 1141 PM CDT Thu Sep 21 2017

VFR conditions are expected to continue through 06z/23 as an upper
level high builds over the Midwest. The wet ground around KMLI and
KBRL may allow a period of MVFR conditions to develop prior to
sunrise Friday. Temperatures in the lower 90s and dew points around
70 will push density altitudes to around 3 kft Friday afternoon.

&&

.CLIMATE...
ISSUED AT 305 AM CDT Fri Sep 22 2017

Record Highs for September 22...

Moline.........95 in 1937
Cedar Rapids...94 in 1930
Dubuque........92 in 1937
Burlington.....94 in 1937

Record Highs for September 23...

Moline.........91 in 2007
Cedar Rapids...90 in 1930
Dubuque........91 in 1891
Burlington.....93 in 2007

Record Highs for September 24...

Moline.........91 in 2007
Cedar Rapids...92 in 1984
Dubuque........90 in 1935
Burlington.....91 in 2007

&&

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

$$

SYNOPSIS...Haase
SHORT TERM...Haase
LONG TERM...Ervin
AVIATION...08
CLIMATE...Haase



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