Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/29/22

Area Forecast Discussion

National Weather Service Lincoln IL

 841 PM CDT Thu Apr 28 2022

.SYNOPSIS...
Issued at 300 PM CDT Thu Apr 28 2022

Periods of showers and thunderstorms are expected through the
first half of the weekend, with the most widespread chances from
late Friday night through Saturday evening. Some of the storms may
be severe Saturday afternoon and evening. Expect overnight
temperatures to remain mild, mainly in the 50s. While Friday`s
highs will only be in the lower 60s, expect widespread 70s to
start the weekend.

&&

.UPDATE...
Issued at 840 PM CDT Thu Apr 28 2022

Weak frontal zone remains stalled over the area. Subtle WAA
continues to produce a few areas of light showers this evening,
though coverage has diminished considerably over the last few
hours. Cloud bases remain around 6-8 kft, so any precip that does
reach the surface should stay light. Made some adjustments to PoPs
through midday Friday, as latest CAMs seem are a bit slower
bringing shower/storm activity into the CWA.

&&

.SHORT TERM...(This evening through Friday)
ISSUED AT 300 PM CDT Thu Apr 28 2022

Showers have been increasing across the forecast area this
afternoon, despite the drier low levels shown on 18Z AMDAR
sounding out of St. Louis and by ceilings generally 8,000 feet or
higher across central Illinois. MRMS show an area of rainfall of a
couple tenths from near Galesburg east to Marshall County. Back
edge of the rain is seen on radar mosaics from near the Quad
Cities to Kansas City. High-res guidance have not had the greatest
handle on this activity, with perhaps the NAM Nest coming closest,
and that one would suggest a general diminishment in the evening.
However, the CAM`s are in better agreement of a cluster of
showers/storms developing after midnight in the central Plains and
moving toward the mid-Mississippi Valley. Highest rain chances
appear to be during the mid morning into early afternoon on
Friday.

.LONG TERM...(Friday night through Thursday)
ISSUED AT 300 PM CDT Thu Apr 28 2022

Initial focus in this section remains with the severe weather
potential for Saturday. Main concern is with the amount of cloud
debris that may be left over from the morning activity, which the
CAM`s have located roughly near I-55 around sunrise. Assuming we
can get enough thinning of the clouds, NAM/GFS both advertise
CAPE`s around 1500 J/kg in the afternoon and 40-50 knots of bulk
shear advancing east across the state, which should be enough to
get some scattered strong/severe storms.

Models are coming into better agreement with the track of the
strong upper low over the central Plains, lifting northeast into
northern Wisconsin by midday Sunday. The bulk of the rain should
be out of our area by late Saturday evening, but a few wraparound
showers can`t be ruled out on Sunday across the northern CWA.

The next storm system also has some good agreement among the
models, with widespread rain chances Monday night and Tuesday.
After that, model divergence takes over with placement of the next
upper low over the central U.S. The GFS is much faster than the
international models and have a storm system over the mid-
Mississippi Valley by Wednesday evening, while the international
models still have it well back in the Plains with a farther south
track. Besides the precipitation discrepancies, the GFS would
suggest another cool shot of air late next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 614 PM CDT Thu Apr 28 2022

SE winds prevail through the period, with gusts of 20-25 kts
during the day Friday. A band of showers is expected to track
from southwest to northeast across the area tomorrow, reaching
KSPI late morning. A few embedded t-storms are possible, though
how far north t-storms occur is uncertain, so refrained from
including VCTS at KPIA/KBMI/KCMI for now. Ceilings should drop to
near or just below 3000 feet in the precip.


&&

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

$$

UPDATE...Erwin
SYNOPSIS...Geelhart
SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...Erwin