Riffel, Illinois Weather Forecast Discussion

106
FXUS63 KILX 100658
AFDILX
Area Forecast Discussion
National Weather Service Lincoln IL
158 AM CDT Wed Sep 10 2025
.KEY MESSAGES...
- An extended period of above normal temperatures begins today,
  continuing through at least early next week, if not longer.
- Little to no precipitation is expected the next 7 days,
  introducing the risk for flash drought conditions through mid
  September.
&&
.DISCUSSION...
Issued at 158 AM CDT Wed Sep 10 2025
Water vapor imagery early this morning shows a trough of low
pressure stretched from the Upper to Middle Mississippi Valleys with
high pressure ridging over the Plains. At the surface we remain on
the western edge of ridging, keeping winds light. Mid to high clouds
associated with the upper disturbance should keep temperatures a
little warmer than previous mornings, though any pockets of clearing
would allow for them to easily drop into the middle to upper 40s
through about sunrise.
The upper trough will slide east today/tonight, allowing upper
ridging to build into the Midwest states by late this week. Little
movement in the pattern aloft will be seen through the weekend and
into early next week as the ridge becomes blocked between two upper
cut-off lows over the northern Plains and Northeast US. Temperatures
will be above normal today, peaking in the low to middle 80s, with
well above normal warmth coming late this week and sticking around
through at least early next week. The deterministic GFS continues to
overmix things this weekend into early next week, resulting in
temperatures that are overdone. Box and whisker plots for MaxT`s
Friday through early next week show the GFS at the max whisker (near
100 degrees), with the mean and 50th percentiles solidly in the
upper 80s to low 90s. Similar to previous forecasts, blended in the
NBM 50th percentile with the raw NBM output to bring some of these
higher-end values down through early next week.
Precipitation chances are very slim the next 7 days, with our next
chance (albeit low) being Saturday night as a backdoor cold front
drops southward. Even if we see anything with this front, QPF will
be inconsequential and likely confined over northern parts of the
state. Much of the area has only seen 10-50% of our typical rainfall
over the last 30 days which has resulted in the development of a
drought conditions. The lack of precipitation paired with the early
Fall heat brings the risk for a flash drought in central parts of
state as highlighted on the Climate Prediction Center`s 8-14 day
hazards outlook.
NMA
&&
.AVIATION...  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1220 AM CDT Wed Sep 10 2025
An upper-level disturbance will continue to bring scattered high
clouds over the regional terminals throughout today before
departing. Skies then become mostly clear and winds go light and
variable once again later tonight as surface high pressure builds
across central Illinois.
MJA
&&
.HYDROLOGY...
Issued at 215 PM CDT Tue Sep 9 2025
Rainfall over the last 30 days in most of the forecast area is
running less than 50% of normal. Analysis from the Midwestern
Regional Climate Center is showing a widespread area from about
Macomb to Mattoon southward at 10% or less, with less than a
tenth inch of rain in south central Illinois. Streamflow
conditions along the Sangamon, Mackinaw and Vermilion Rivers are
much below normal. Significant concern exists that the extended
heat, along with soil moisture rankings below the 20th percentile
and the meager rain prospects over the next week or two, will
trigger flash drought conditions. CPC 8-14 day hazards outlook is
highlighting a large area south of I-72 as being at risk of rapid
onset drought, with much of this region already at D0/D1 level
drought conditions. Longer range ensembles suggest the above
normal temperatures will continue through the remainder of
astronomical summer, and CPC 8-14 day temperature outlooks show a
greater than 50% chance of above normal temperatures from
September 16-22nd.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$

NWS ILX Office Area Forecast Discussion