Area Forecast Discussion
Issued by NWS Central Illinois

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159
FXUS63 KILX 311056
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
556 AM CDT TUE MAY 31 2016

.SHORT TERM...(Today)
ISSUED AT 328 AM CDT Tue May 31 2016

Remnant MCV over south central Missouri will migrate slowly
northeast today and bring our area more cloud cover than what we saw
yesterday along with scattered showers and thunderstorms. Already
seeing some isolated convection developing just to our north with
radar mosaics to our south indicating an area of mostly showers
moving northeast out of Missouri. Forecast soundings today very
similar to what we saw yesterday with 0-6km shear not much more than
20 kts with mixed layer capes up to 1500 j/kg and poor 700-500 mb
lapse rates. The wind profile today once again looking more like the
middle of July, as the steering flow will be around 10 kts,
suggesting any storm that does develop will be slow moving and
capable of producing heavy rainfall in a short period of time, but
very localized in nature. Temperatures may be a degree or two cooler
than what we saw yesterday with the increase in cloud cover, but
forecast soundings indicate that if we experience any significant
breaks in the clouds today, the temperature will have little problem
getting into at least the mid 80s.

.LONG TERM...(Tonight through Monday)
ISSUED AT 328 AM CDT Tue May 31 2016

Still a bit of a summery pattern and warm for the first part
of the week.  Showers/thunderstorm chances increasing with proximity
to approaching boundary from the west as another low digs in over
the Northern Plains and drags a front through the Midwest.
Models have been increasingly consistent with handling the
boundary...but the precip timing with the smaller showers out ahead
of the system tonight remains a bit loose.  Considering current
situation is not necessarily handled well, this evening will be
influenced by mesoscale features, but have left pops highest in the
west with the approach of the sfc trof. Temperatures remain warm
through the forecast.  A few degrees cooler behind the boundary, but
not by much and not for long...as southerly flow at the sfc
reestablishes and sets up WAA briefly going into next weekend. That
being said, Wed high temperatures are going to be partially
dependent on breaks in the clouds and how quickly they can climb
before rain dominates the region. Plenty of warm air lending itself
to moderately unstable air to work with the thunderstorms on Wed/Wed
night...but weak flow pattern aloft will limit the shear available
for severe weather development.

On the other side of the boundary...warm air remains...and a loose
height gradient and weak flow aloft until the next low digs in over
the Northern Rockies. The surface low developing over the Upper
Midwest and into the Great Lakes moving across the country in
concert with another surface low developing over the Gulf Coast.
The upper trof and surface feature dragging through the region
alerting a pattern shift and models will likely remain split between
filling in with precip across ILX... or putting Central Illinois
between the two more favored regions for precip.  Most of Thursday
and Friday remain dry in the forecast until that system encroaches
on the region and pops begin to increase through the weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 550 AM CDT Tue May 31 2016

Forecast concern this period will be coverage of TSRA as a weak
weather disturbance moves into our area from Missouri later today.
Mainly VFR cigs over the forecast area early this morning with
isolated showers and thunderstorms along and north of I74 with
another band of showers pushing into southwest Illinois. Coverage
today will be similar to what we saw yesterday although with the
upper level disturbance pushing through during peak heating, we
may see better coverage this afternoon but it still appears VCTS
will cover this synoptic setup for today. It appears that we will
see a temporary decrease in coverage this evening before a cold
front starts to approach the area from the west late tonight
bringing a better chance for TSRA to at least PIA and SPI after
06z. Surface winds will not be much of a factor today, unless a
thunderstorm affects a TAF site, otherwise look for a southeast
to south wind to prevail today with speeds of 10 kts or less.
Winds should back more into a southeast direction tonight with
speeds of around 5 kts or less.

&&

.ILX Watches/Warnings/Advisories...
NONE.
&&

$$

SHORT TERM...Smith
LONG TERM...HJS
AVIATION...Smith



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