Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 060832
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
332 AM CDT Thu Aug 6 2020

.SYNOPSIS...
Issued at 326 AM CDT Thu Aug 6 2020

KDVN WSR-88D is detecting a few showers early this morning over
portions of eastern Iowa. This is attendant to a vort max within
passing shortwave trough juxtaposed with leading edge of elevated
warm advection and mid level moist axis, both of which increase
farther west where additional showers were noted from southwest
Minnesota through western Iowa. Otherwise, it remains comfortably
cool with temperatures ranging from the mid 50s where skies are
mainly clear /northwest into west central Illinois in close
proximity to surface high pressure/ to around 60ish where skies
are mostly cloudy.

&&

.SHORT TERM...(Today and Tonight)
ISSUED AT 326 AM CDT Thu Aug 6 2020

A few showers will persist this morning west of the Mississippi
River. However, I can`t rule out isolated/widely scattered
development really at any time beyond this morning given proximity
to weak mid level warm, moist advection which is progged to
generally persist. Areas west of the Mississippi River would be
favored for any additional shower chances beyond this morning
residing in/near 850-700 mb moist axis. Of particular note is a
secondary lobe of vorticity diving down through eastern South
Dakota and southwest Minnesota currently, which earlier assisted
a few storms but now just scattered showers into portions of
western Iowa. This times into of our area during the afternoon
and will need watching for some additional mention/increase of
PoPs western sections. Otherwise, a sun/cloud mix on tap today
with a little increase in southerly winds west of the Mississippi
at 10-15+ mph with some increase in pressure gradient. This
will likely draw dew points in these areas to around 60 or lower
60s slightly noticeable while elsewhere still comfortable.
Clouds make the high temperature forecast a bit challenging, but
have noticed it seems many areas past few days have been near
or a little above warm side of guidance and this likely attributed
feedback from dry conditions with a dry ground having the ability
to conduct heat far more efficiently. Therefore, I`ve gone at or
above guidance for highs today despite the clouds and forecasting
generally upper 70s to lower 80s.

Tonight, as already mentioned can`t really rule out some showers
at any time west of the Mississippi River. However, more
uncertainty is present as models show some amplification of
700-500 mb ridging into the area overnight, and main signal for
precipitation to our south/west within the strongest theta-e
advection. Lows once again should dip into the 50s where skies
stay mainly clear, while mostly cloudy areas will see lower 60s.

.LONG TERM...(Friday through Wednesday)
ISSUED AT 326 AM CDT Thu Aug 6 2020

Essentially not much change in the extended period, with typical
summertime heat and humidity returning to the region along with
nearly daily slight or low chances of showers or storms.

Friday into Saturday remains the time frame with the highest
probability (40-50 percent) for seeing showers and storms across the
SW third of the CWA. The rest of the CWA has 20-30 pops. This is
when a shortwave may trigger an MCS across portions of the area.
Another nocturnal episode of higher pops (40 percent) is slated for
Sunday night into Monday, when a warm front lifts across the area
followed by a cold frontal passage on Monday. Beyond those periods,
each other period has 20 to 30 pops as the upper zonal flow pattern
remains active and the cold frontal boundary stalls out just south
of the region. Confidence remains low in regards to timing and
placement of the pops.

Hot and very humid conditions are still expected for the weekend and
into Monday. Sunday appears to be the hottest day of the three, with
highs in the upper 80s to low 90s, dew points in the low to mid 70s,
resulting in heat indices in the mid 90s to low 100s. A heat
headline may be needed for Sunday afternoon into early evening.
Tuesday and Wednesday, temperatures will settle back into the 80s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
ISSUED AT 1250 AM CDT Thu Aug 6 2020

VFR conditions expected to persist through the TAF period, with
southerly winds increasing to 5-15 kts. A few showers will
dot the area early this morning, mainly over portions of
northeast into east central Iowa. Can`t rule one out at CID and
DBQ, but left out due to isolated coverage. Impacts look to be
minimal even should one occur at either of these terminals.
After early this morning additional low chances for showers and
storms will exist later tonight with warmer air moving in aloft.
Being fairly late in the TAF period and with uncertainty on extent
of any coverage given main signal for development is to our west
and south, will not have any mention at this time.

&&

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

$$

SYNOPSIS...McClure
SHORT TERM...McClure
LONG TERM...14
AVIATION...McClure


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