Pisgah, Iowa Weather Forecast Discussion

003
FXUS63 KOAX 170628
AFDOAX
Area Forecast Discussion
National Weather Service Omaha/Valley NE
128 AM CDT Wed Sep 17 2025
.KEY MESSAGES...
- Scattered off-and-on storms are expected across the entire
  area today. The best chance for widespread rain is this
  morning, but scattered storms will linger into the afternoon
  as well. There is a small chance for one or two severe storms.
- Another round of thunderstorms is expected on Thursday. Severe
  weather is once again unlikely.
- Cooler temperatures for the mid-to-late week in the 70s, with
  80s returning this weekend into early next week.
&&
.DISCUSSION...
Issued at 130 AM CDT Wed Sep 17 2025
A broad upper trough with multiple embedded vorticity maxima was
drifting every so slowly across the central and northern Plains
early this morning. It is worth noting that one of the embedded
short wave vort maximums was lifting northeast toward central
Nebraska. Two separate waves currently centered over northern
Colorado and the Yellowstone region will rotate around each
other over the next couple of days as they slowly drift east.
Current weather through this afternoon will be driven by this
first short wave trough and a frontal boundary draped across the
region. Early this morning, the front has been modified
significantly by convective outflow but generally stretches from
northwest KS into south central NE, and then up toward the SD/IA
state line. The low level jet this morning in advance of the
wave has been sufficiently strong to support continued
convective development, both along and north of the effective
front as well as in parts of the warm sector. Most Unstable CAPE
of 1000 J/kg is common across the area while deep layer shear is
not particularly impressive. Those MU parcels are weakly or even
uncapped, hence the scattered development. While there were a
few stronger updrafts this evening, instability has waned a bit
and believe it will be difficult for storms to become severe
from this point forward. The exception may be a linear segment
crossing through south central NE which may be capable of
producing some wind if it can force some momentum to the
surface. Forecast soundings and CAPE profiles ahead of this
system seem to favor elevated convection with weakening
instability as it progresses east, but can`t totally rule out
some wind.
As the day progresses and the center of the wave approaches,
there are indications in model guidance of some destabilization
around mid afternoon which may reinvigorate convection (although
the bulk of it may be east of the forecast area), and may also
provide a focused zone for additional development near the
center of the short wave. Hodographs in this area have a fair
amount of low level shear and turning. Would call this a highly
conditional scenario for a few severe storms, based largely on
the existence of surface based instability on the higher end of
the envelope of guidance...but if strong updrafts develop near
the upper circulation, shear profiles may favor some
organization with hail or even a non-zero tornado potential.
Again...highly conditional.
The abundance of model guidance is surprisingly consistent in
the predominant circulation tracking into north central NE or SD
by Thursday morning and lifting north while the Yellowstone vort
rotates around the south side and ejects into eastern Nebraska
Thursday into early Friday. Right now, it looks like slightly
drier air will cover much of the area tonight into the first
part of Thursday, with the exception perhaps being in the
southeast part of the forecast area where showers or storms may
track through. Later Thursday into Thursday evening then looks
like another better chance for scattered thunderstorms.
Intensity of the storms will lie in the details of daytime
heating, but could again see a few strong ones. Scattered
showers or a storm may continue into Friday over the eastern
areas, but will finally see a weather pattern change by the
weekend. Much of the weekend looks to be dry, but with a few
low-end chances for rain. Better rain chances return when a fast
moving short wave crosses the northern Plains on Monday. This
system will be followed by a period of upper ridging.
&&
.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1233 AM CDT Wed Sep 17 2025
This is a very complex TAF period in terms of wind directions
and timing of TSRA. Scattered TS were at or near all TAF sites
at 0530Z, with continued sporadic development expected through
the next 12 hours. OFK looks to have the most persistent TSRA
activity in the next few hours. Otherwise, a line of storms
moving in from the west will likely impact LNK and OMA by 10-14Z
time range. Can expect reduced vis in TS, as well as some gusty
and sporadic winds. Additional stormy periods are possible later
in the TAF, but too difficult to nail the timing until getting
closer to that time.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Barjenbruch
AVIATION...Barjenbruch

NWS OAX Office Area Forecast Discussion