660
FXUS63 KOAX 172308
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
608 PM CDT Thu Jul 17 2025

.KEY MESSAGES...

- Quiet conditions this afternoon with highs in the low to mid
  70s and light winds.

- Slight chance (15-20%) for a shower or storm south of I-80
  Friday morning. Better chance (50-60%) at some showers and
  storms across most of the forecast area Friday evening into
  Saturday morning. Some storms could be strong to severe.

- Shower and storm chances continue Saturday (20-40%) with daily
  chances through Wednesday (15-30%), increasing the flood
  threat after each round. Dangerous heat returns next week.

&&

.DISCUSSION...
Issued at 327 PM CDT Thu Jul 17 2025

.SHORT TERM.../Today through Friday Night/

Quiet weather is observed across much of the Northern Plains this
afternoon as a 1021 mb sfc high sits over the eastern Dakotas, much
of Minnesota, eastern Nebraska, and Iowa. Aloft at H5, generally see
zonal to slightly northwesterly flow across the region with a few
bits of vorticity embedded, and given some lingering midlevel
moisture, will see enough weak forcing for clouds throughout the
day. However, expect dry conditions this afternoon. High
temperatures will be cool for July standards as they reach the low
to mid 70s, and with lower dew points (compared to previous days),
it should make for a fairly comfortable day to be outside. Lows
tonight will be in the low to mid 60s.

Sfc high will push off toward the Great Lakes area by early Friday
morning. H5 zonal flow will allow for several shortwaves to sneak
through, the first of which will eject from the eastern Rockies in
the early morning hours. This shortwave will induce a sfc low across
southwest South Dakota and the Nebraska Panhandle. At H8, will see
southwesterly flow resulting in warm air advection creating some
weak lift early Friday morning. As a result, some CAMs try to
generate a few widely scattered showers and storms after 9z,
primarily south of I-80 were moisture transport is also observed.
Have included some low end PoPs across this area (15-20% chance)
through about 15z.

Meanwhile, the sfc low will track across the South Dakota/Nebraska
border throughout the day Friday with the warm front swinging to the
northeast and the cold front pushing through much of western and
central Nebraska by the early evening. Forcing with the mid level
shortwave looks rather weak with H5 height rises suggested by some
models, but low level convergence along the cold front may be
sufficient to generate some showers and storms. Moisture and
instability will pool behind the warm front with dew points rising
to an uncomfortable low to mid 70s and MUCAPE around 2,500 J/kg. A
few models show us capped for a large portion of the afternoon and
evening hours, while models like the 12z HRRR show capping eroding
by 23z. 0-6 km bulk shear appears favorable for strong to severe
storms, with values of 35 to 40 kts mainly north of I-80.

While there are still some subtle CAM differences, they seem to
suggest storms first forming across portions of central into
northeast Nebraska along the boundary, eventually congealing into a
cluster and moving to the southeast across the Missouri River
Valley. Soundings show a pocket of dry air aloft, with DCAPE around
1,000 J/kg so certainly could see some damaging wind gusts if
clusters can grow upscale. Can`t also rule out seeing some hail. The
SPC currently has a marginal risk of severe weather for areas along
and north of I-80. PWATs around 1.75 inches coupled with favorable
warm cloud depths may also lead to efficient rainfall with these
storms. PoPs currently peak at 50 to 60% Friday evening and move
from south to north.

High temperatures Friday will be in the low to mid 80s, with lows
Friday night reaching the upper 60s to low 70s.

.LONG TERM.../Saturday through Wednesday/

PoPs linger early Saturday morning across the south before yet
another H5 wave moves east. Coupled with the lingering boundary from
Friday`s system, lingering instability and moisture, and favorable
bulk shear, could see another round of showers and storms develop in
the afternoon and evening hours. NBM PoPs peak at 20 to 40% Saturday
evening. Questions remain, however, regarding how much
destabilization will occur given lingering cloud cover and storms
from Friday`s system. Highs Saturday will be in the mid 80s north of
I-80 to low 90s along the Nebraska/Kansas border.

By Sunday, will see a ridge build across much of the southwest US,
changing the flow at H5 from zonal to more of a southwesterly type
flow. Shortwaves will ride this flow, creating almost daily 15-30%
PoP chances. It is worth mentioning that flooding potential will be
on the increase with each round of storms that we see from Saturday
through the extended period.

Heat will also be of concern as the ridge builds, with
NBM extended showing temperatures warming a few degrees each day,
reaching the mid 90s to near 100F south of I-80 by Wednesday. Heat
indices will feel uncomfortable, with values in the upper 90s to low
100s at times in the afternoon hours. Those with outdoor plans next
week will want to pay attention to the forecast as heat headlines
may return.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 603 PM CDT Thu Jul 17 2025

VFR conditions are favored this evening with a scattered to
overcast cloud deck remaining in place at FL035-050, with brief,
localized drops to MVFR conditions possible. Winds will continue
at calm speeds out of the east- southeast. MVFR ceilings will
redevelop during the early morning hours, likely impacting all
terminals before gradually improving later in the morning. Brief
periods down to IFR conditions will be possible, primarily at
KLNK. Winds will increase above 12 kts at KOFK during the mid
morning, with afternoon gusts up to 20 kts possible.

&&

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

&&

$$

DISCUSSION...Castillo
AVIATION...Wood