FXUS63 KOAX 190447
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1147 PM CDT Mon May 18 2026

.KEY MESSAGES...

- Cooler weather moves in on Tuesday with potential for morning
  frost for northeast Nebraska on Wednesday.

- Shower/thunderstorm chances return Wednesday night into
  Thursday continuing on/off through Friday.

- Trend back toward warmer temperatures over the weekend.

&&

.DISCUSSION...
Issued at 1050 PM CDT Mon May 18 2026

Severe weather has cleared to the southeast this evening leaving
cool, cloudy conditions in place for the overnight hours. We
have a large temperature gradient across the area with 
temperatures in the upper 40s across northeast Nebraska, to 
low-to-mid 60s in southwest Iowa and far southeast Nebraska. The
HRRR continues to show some potential for a couple additional
storms developing over far southeast Nebraska and southwest Iowa
around midnight tonight. If anything were to develop, it likely
wouldn't be severe. 

Skies will be clearing Tuesday morning as high pressure builds
over the area. Cooler air mass remains in place under northerly
flow. Overnight Tuesday night into early Wednesday we light
winds and clear skies contribute to temperatures dropping into
the low-to-mid 30s across northeast Nebraska, possibly
necessitating a frost advisory for this area. Places more across
southeast Nebraska and southwest Iowa will see temperatures drop
into the upper 30s to low 40s, though a few outlying areas 
around Omaha and Lincoln could still see some patchy frost.

High pressure remains centered over the region on Wednesday
keeping temperatures cooler than normal with highs in the upper
50s to low 60s. The trough over the northern Rockies starts to 
deepen on Wednesday, re-amplifying southwesterly flow across 
our region. This will bring moisture back to our area with 
increasing clouds into the afternoon. 

Rain chances return late Wednesday into Thursday as the trough 
over the northern Rockies starts to deepen, re-amplifying 
southwesterly flow across our region which will lead back to 
moisture advecting back into our area from the Gulf. As a warm 
front lifts into northern Kansas on Wednesday, we see isentropic
upglide over our area lead to shower and storm development 
starting Wednesday night continuing into Thursday. We don't 
actually see the warm front lift into our area until Friday, 
keeping temperatures cool on Thursday as well. 

Friday the warm front lifts north, getting wrapped up into a
developing surface low over the Northern Plains. This will
reinvigorating shower and storm chances through the morning 
hours. We may see a small window of clearing before the cold 
front arrives Friday afternoon/evening. We should watch this
period with some potential for severe storms, but at this time
there is still a lot of uncertainty surrounding the details of
this system.

Confidence significantly decreases in the forecast going into
next weekend as significant differences in the forecast of the
upper-level pattern develop. Ensembles suggest a trend back
toward warmer-than-normal temperatures toward the latter-half of
the weekend with low chances for storms possible Saturday and
Sunday.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1143 PM CDT Mon May 18 2026

IFR to MVFR ceilings are in place at the terminals this 
evening, with breezy northwesterly winds gusting to 20-25 kts 
expected to last through the overnight hours. Radar data carried
forward by the short-term model is indicating that areas of 
drizzle will continue to develop/move to the east of the area, 
affecting KOMA to dip into MVFR visibilities at times through 
08z. Otherwise, expect slight improvement to ceilings overnight,
with sustained winds loosening after sunrise, with winds 
turning increasingly northerlywhile dropping gusts completely 
around or shortly before 00z tomorrow. 

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.

&&

$$

DISCUSSION...McCoy
AVIATION...Petersen