Graf, Nebraska Weather Forecast Discussion

465
FXUS63 KOAX 210929
AFDOAX
Area Forecast Discussion
National Weather Service Omaha/Valley NE
429 AM CDT Sun Sep 21 2025
.KEY MESSAGES...
- Fog will once again be expected this morning across portions
  of the area. A Dense Fog Advisory has been issued for several
  counties through 9AM.
- Periodic showers and thunderstorms will be possible through
  the upcoming week as several disturbances move through the
  Central Plains.
- Dry conditions are expected for the latter half of the week.
&&
.DISCUSSION...
Issued at 428 AM CDT Sun Sep 21 2025
The forecast period starts out with the remnants of a boundary
extending from Axtell to Fairbury. A few showers and maybe an
isolated storm may develop along the boundary this morning into the
afternoon. The rain chances (15-30%) will be limited to south of I-
80, with the highest chances along and south of the boundary.
Elsewhere, radiational cooling, light southerly winds, and warm air
advection over a cool and moist surface has been conducive for fog
development this morning, particularly for southeastern Nebraska and
southwestern Iowa. A Dense Fog Advisory has been issued for several
counties across eastern Nebraska and western Iowa through 9AM.
Expect visibility reductions to one quarter mile or less within the
advisory area.
Split flow remains over the western CONUS with a ridge over Montana
and an upper trough coming ashore over southern California. A closed
upper low over eastern North Dakota and northwestern Minnesota will
slide east today with the Central Plains under northwest flow. Late
this afternoon into early evening, chances for showers and storms
decrease in southeastern Nebraska/southwestern Iowa and increase (15-
20%) in northeastern Nebraska/northwestern Iowa. A few strong to
marginally severe storms will be possible with hail and gusty winds
being the main concerns.
Monday, the upper trough moves off to the east over Lake Superior.
An upper trough over the Rockies will deepen, with a closed upper
low developing to the west of the Bighorns. Isolated chances (15-
20%) will be possible in the northwestern Iowa and northeastern
Nebraska during the morning with exit of an upper wave. Increased
coverage and chances (30-50%) for showers and storms are expected
Monday evening as the closed low slides southeast. A few strong to
severe thunderstorms will be possible Monday afternoon and night.
Storm chances (40-70%) will continue during the day Tuesday,
decreasing to 20-40% in the evening. Precipitation chances will
end by Wednesday afternoon.
Monday highs will be in the upper 70s to mid-80s. Lows will be in
the upper 50s to mid-60s. Cooler air filters into the region Tuesday
and Wednesday, with highs returning to the low to mid-70s. Lows will
be in the 50s and 60s.
Northerly flow sets up over the region on Thursday, ahead of a ridge
progressing east into the region by Friday. The majority of the
region should be dry, with the one exception being extreme
southeastern Nebraska Thursday morning as lingering showers exit the
region. Friday into the weekend, highs will be back in the mid-70s
to low 80s with lows in the 50s.
&&
.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1203 AM CDT Sun Sep 21 2025
VFR conditions this evening with scattered clouds around FL250.
Winds are light, generally out of the south or southeast. Models
have backed off on fog as far west as KLNK and KOMA, keeping
more confined to southwest Iowa and far southeast Nebraska. For
this reason, have removed fog from the TAFs, but KOMA still has
around a 20% chance fog impacts the terminal between 11-15Z. For
this reason, have kept MVFR vis moving in around that time
period with potential for some haze developing. After 15Z,
expect VFR conditions the prevail through the remainder of the
TAF period with winds increasing out of the south to 10g20kt for
the afternoon hours, then backing back down to around 5-7 kt
around 00-01Z Sunday evening.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...Dense Fog Advisory until 9 AM CDT this morning for NEZ045-052-
     053-067-068-091-093.
IA...Dense Fog Advisory until 9 AM CDT this morning for IAZ055-056-
     069-079-080-090-091.
&&
$$
DISCUSSION...ANW
AVIATION...McCoy

NWS OAX Office Area Forecast Discussion