Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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000
FXUS63 KDVN 261758
AFDDVN

Area Forecast Discussion
National Weather Service Quad Cities IA IL
1258 PM CDT THU MAY 26 2016

...18z AVIATION UPDATE...

.UPDATE...
Issued at 650 AM CDT Thu May 26 2016

Area of thunderstorms that moved across the cwa was shifting east
of the MS River early this morning. The storms produced 70-80 mph
winds in Buchanan county earlier this morning. The storms will
exit our cwa by 9 am or so as upper level disturbance pushes to
our east.

The remainder of the day looks dry and very warm with subsidence
in the wake of the departing wave. Convective temperatures are
well in the 80s so it will be late this afternoon or evening
before any new thunderstorms develop.

&&

.SYNOPSIS...
Issued at 100 AM CDT Thu May 26 2016

Thunderstorms continue to increase in coverage from southern
Minnesota into northern Missouri during the early morning hours.
Leading storms had moved into southeast Iowa. The most intense
storms were producing some hail and strong wind gusts. Warm and
moist air remained in place across the area, with early morning
temperatures in the mid 60s to low 70s.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 100 AM CDT Thu May 26 2016

The main forecast issues are convective trends and intensity this
morning, and again from late afternoon through tonight.

In the near term, strong storms are moving into the southwest
portion of the forecast area. There may be some small hail, but
the biggest concern would be isolated downburst winds in an
environment with DCAPE above 1000 J/kg. Storms in western and
north central Iowa have produced gusts over 80 mph. Deep layer
shear is pretty meager to support very large hail, so again, am
focused on isolated strong wind gusts through the early morning.
High resolution models generally support a weakening trend for the
western Iowa convection as it moves into the Quad Cities forecast
area through the morning. Expect storms to exit to the east by
late morning, with mainly dry conditions expected until at least
late afternoon as temperatures peak again in the mid to upper 80s.

From early evening through the overnight hours, there is still
considerable uncertainty as to the location of remnant outflow
boundaries from the morning storms. Much of the western portion of
the forecast area has been included in the day 1 slight risk
area, and this does appear to be favored for stronger deep layer
shear and forcing from shortwave energy riding up the southwest
flow aloft. A few storms could pose a wind/hail threat, but areas
from northern Missouri into central Iowa should have more
organized storms.

.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 100 AM CDT Thu May 26 2016

Forecast focus on chances of storms through the extended along with
above normal temperatures.

Friday through Saturday night, looks quite active with the upper
level trough coming out of the Plains and into the Midwest. Large
scale ascent and a decent low-level jet should act on sufficient
deep layer shear and instability to support several rounds of
thunderstorms. Can`t rule out a few severe thunderstorms during the
period but shear is still not that impressive. Also, this is a
positive-tilt trough and a weak surface low which would support a
low end event. Due to more cloud cover and better coverage of
showers and storms temperatures will not be as warm. Highs should be
in the upper 70s to lower 80s.

Sunday through Memorial Day, a quieter period with only slights or
very small pops as troughing re-loads back in the Rockies. With more
sunshine temperatures will be warming back into the lower to mid 80s.

Tuesday through Wednesday, active pattern returns as upper level
trough swings out into the Plains. Thunderstorm chances will be on
the increase once again. Highs will remain above normal in the lower
80s at most locations.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1247 PM CDT Thu May 26 2016

A VFR afternoon with thickening high clouds from storms off to the
southwest...south to southwest winds of 6-10 KTS. Then eyes turn
to the storm clusters ongoing in northwestern MO and if some of
them can get into the VCNTY of the BRL TAF toward sunset this
evening. Mys just be decaying remnants initially, but chances are
more thunderstorms developing out west and southwest will come
acrs many of the TAF sites tonight, with heavy rain and possibly
gusty winds. Timing and how far north or south they occur at lower
confidence levels at this point and will place VCNTY and PROB30`s
of thunderstorms and associated MVFR to IFR conditions at
MLI/CID/DBQ for periods of tonight. Will go predominant at BRL
from mid evening and into the overnight as the south may be more
favorable for widespread storm system coverage. ..12..

&&

.DVN Watches/Warnings/Advisories...
IA...None.
IL...None.
MO...None.
&&

$$

UPDATE...Haase
SYNOPSIS...RP Kinney
SHORT TERM...RP Kinney
LONG TERM...Haase
AVIATION...12



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