Sicily, Nebraska Weather Forecast Discussion

357
FXUS63 KOAX 162343
AFDOAX
Area Forecast Discussion
National Weather Service Omaha/Valley NE
643 PM CDT Tue Sep 16 2025
.KEY MESSAGES...
- Weak storms continue to be possible into the evening hours
  before an MCS approaches from the west, with a gust up to 60
  mph and quarter-sized hail possible overnight as it arrives.
- 60 to 80% chance of storms for Wednesday, and continued rain chances
  through at least Saturday. Repeated rounds of rainfall may
  result in localized flooding concerns.
- Cooler temperatures for the mid-to-late week in the 70s, with
  80s returning this weekend into early next week.
&&
.DISCUSSION...
Issued at 358 PM CDT Tue Sep 16 2025
Water vapor imagery this afternoon features a swirling mid/upper low
situated over the northern Intermountain West, beginning to pivot
eastward and spread increasing convection across the central High
Plains and points eastward. Taking a look at visible satellite
locally, a widespread field of cumulus has developed with pockets
increased depth to the southeast of a leftover outflow boundary
across northern Nebraska into southeast South Dakota from earlier
convection.
Shower and storm development continues to the main concern in the
short term, with CAMs continuing to be all over the place in their
handling of the afternoon and early evening ahead of the better-
resolved MCS currently coming together over western Nebraska. The
18z KOAX sounding showed an uncapped environment representative of
within the aforementioned cloud field, with a good amount of drier
air near the surface that is going to keep overall coverage low
but not zero. Storms that do form will enjoy 2500-3500 J/kg of
CAPE while effective shear values hang around a paltry 10 kts.
These pulse- like storms will have their best chance to develop
over the next few hours until we start losing daytime heating,
only mustering a brief downpour, a gust of wind, and small hail.
The secondary and more intense convection will be the incoming
MCS that will be pushing into decreasing instability across
eastern Nebraska and western Iowa, with most models depicting it
as a broken line of storms producing 40-50 mph gusts at times.
If a locally strong portion of the bow is able hold on, we could
see gusts to 60 mph and a few quarter-sized hailstones from 11
PM to 4 AM depending on how quickly the MCS gets to the area. As
far as the rest of the showers and storms, they`ll continue to
push through the area through the early morning , with
occasional rumbles of thunder continuing to sweep eastward
through the early afternoon. By 7 PM, another lobe of the
primary mid/upper low will begin swinging into the area and will
try to develop another round of storms across central into
eastern Nebraska. Similarly low shear will accompany these
storms and be joined by even less shear, leading to limited
severe potential.
Thursday onward, the forecast will continue our active pattern with
additional shortwaves joining into the slow-to-eject one across the
Central/Northern Plains. We`ll enjoy cooler temperatures that top
out in the 70s with troughing situated squarely over our area and
remaining band of precipitation chances sweeping eastward by
Saturday. For the weekend, the mid/upper pattern begins to diverge
from model to model, but the general trend is for ridging to
build to the west as zonal to slightly northwesterly flow
develops aloft. The exiting upper low will allow for highs to
return to a few degrees of 80 for the weekend into early next
week as a particularly deep low misses us to the east.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 639 PM CDT Tue Sep 16 2025
Isolated and very short-lived thunderstorms have occasionally
developed along the Missouri River and western Iowa, in the
vicinity of KOMA. These storms will decrease in number as the
sun sets.
Most of the shower and thunder activity will wait until after
10Z Wednesday when the next wave works its way through the area
from west to east. Timing is still a bit uncertain, but will be
refined in future TAF issuances. Otherwise, mostly southeasterly
winds are forecast over the period with VFR ceilings.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Petersen
AVIATION...Nicolaisen

NWS OAX Office Area Forecast Discussion