Area Forecast Discussion
Issued by NWS Central Illinois

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824
FXUS63 KILX 261957
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
257 PM CDT Wed Jul 26 2017

.SHORT TERM...(Today and tonight)
ISSUED AT 251 AM CDT Wed Jul 26 2017

Stationary front near Mississippi River will push east this
evening bringing periods of thunderstorms to the region mainly
overnight. As evidenced by the 12z area soundings and the limited
convection so far this afternoon, the 12z NAM seems to be
overdoing moisture content of the atmosphere above the boundary
layer. Based on 12z GFS and ECMWF, areas of 1 to 2 inch rains
with locally higher amounts still will be possible as an
approaching shortwave interacts with the boundary. In addition
moisture levels should increase as a LLJ develops this evening,
but NAM is substantially higher than other models with amount of
moisture transport. With 3-hr flash flood guidance mostly above
2.5 inches, flood threat should not be widespread and we will be
cancelling the Flash Flood Watch that had been in effect for
tonight and early Thursday.

.LONG TERM...(Thursday through Tuesday)
ISSUED AT 251 AM CDT Wed Jul 26 2017

The precip should linger through much of the day Thursday,
particularly south of I-74, as the boundary gets hung up between
tonight`s shortwave and a stronger shortwave approaching the area
tomorrow. The bulk of the moisture should be pushed south of the
area though and although this next wave will have stronger
dynamics, clouds will keep instability limited. The main impact
will be clearing us out after its passage and setting us up for a
prolonged period of northwest flow and below seasonal temperatures
through much of next week.

As the pattern of trough east and ridge to our west remains
through the period, high pressure will dominate at the surface.
Although several waves will top the ridge they should have minimal
impact on the region as low-level moisture is bottled up in the
deep south by the surface ridge.

Next chance of precip will be toward the later half of next week
as a stronger wave breaks down the ridge to our west.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1210 PM CDT Wed Jul 26 2017

Stationary front near the Mississippi River will begin to push
east ahead of a shortwave moving southeast into the Lower Missouri
Valley this afternoon. Scattered convection will likely develop
along this boundary but coverage limits due to relatively dry
atmosphere warrant leaving out of terminals at this time. Best
chances of anything impacting our area would be at KSPI.

Better chances of convection will move southeast with the area
overnight associated with the aforementioned shortwave. Periods of
Precipitation and possibly some MVFR ceilings will persist through
the morning Thursday as a cold front stalls over the area in wake
of the shortwave.


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Barker
LONG TERM...Barker
AVIATION...Barker



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