-- Discussion containing changed information from previous version are highlighted. --
684
FXUS63 KOAX 192338
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
638 PM CDT Wed Jun 19 2024

.KEY MESSAGES...

- Rain chances continue through Saturday and then return to the
  forecast Tuesday and Tuesday night. Isolated occurrences of
  severe weather and/or flooding are possible, especially
  across portions of northeast NE and west-central IA.

- Gradually warming temperatures through the weekend into early
  next week. Heat indices approaching 100 to 105 on Monday and
  Tuesday.

&&

.DISCUSSION...
Issued at 323 PM CDT Wed Jun 19 2024

.Tonight into Thursday night:

A prominent mid-level high centered along the mid-Atlantic coast
today is forecast to build west into the OH and TN Valleys,
resulting in building heights across the central Plains. At the
surface, a front extending from northeast MO into southern KS
as of early afternoon is forecast to lift north as a warm front
with that feature moving back into our area on Thursday.

Warm advection associated with the development of a nocturnal
low-level jet is expected to support widely scattered showers
and thunderstorms this evening into tonight across portions of
western and central NE, to the north of the above-mentioned surface
boundary. That activity is expected to spread east/northeast
into our area late tonight into Thursday morning with the
highest measurable precipitation chances across northeast NE.

The duration and coverage of morning precipitation will dictate
the degree of air mass destabilization that occurs Thursday
afternoon along and to the south of the warm front lifting north
into the area. However, it does appear that at least widely
scattered thunderstorm development is possible along the
boundary during the afternoon and evening hours. Model soundings
at peak heating indicate a moist(e.g., PW values of 1.5-1.9")
and moderately unstable environment amidst a vertically veering
wind profile with generally weak vertical wind shear. So, while
organized storm modes aren`t anticipated, locally strong wind
gusts (from wet microbursts) and/or locally heavy rainfall are
possible. Highs on Thursday will range from the upper 70s near
the SD border to mid to upper 80s across southeast NE and
southwest IA.

Showers and thunderstorm chances continue into Thursday night
across northeast NE and west-central IA with the best potential
for heavy rain existing near the SD border.

.Friday and Saturday:

The surface front will remain in the vicinity of the NE-SD
border on Friday where another round of thunderstorms is
possible, especially from mid afternoon into Friday night.
Indications are that the environment will become moderate to
strongly unstable to the south of the boundary and isolated
severe storms are possible near the state line.

On Saturday, the 12z global models are in good agreement in
suggesting that a shortwave trough will progress through the
northern Plains with the above-mentioned front moving back
through our area as a cool front. Best thunderstorm chances will
be across northeast NE and western IA at that time, and some
potential will exist for a severe storm or two.

Forecast highs are in the upper 80s to low 90s on Friday, and
mid 80s to mid 90s on Saturday.

.Sunday and Monday:

A mid-level ridge will temporarily build across the north-
central U.S., contributing to generally dry conditions during
this time frame. Highs in the mid 80s to lower 90s Sunday are
forecast to warm into the lower to mid 90s by Monday with heat
indices approaching 100-105 along and south of I-80.

.Tuesday and Tuesday night:

The models indicate a vigorous shortwave trough moving through
the upper MS Valley with an associated cool front moving into
our area. The front will be the focus for another round of
showers and thunderstorms with some risk for flooding and/or
severe weather. However, specific details remain uncertain at
this time. It will be another hot, humid day ahead of the front
with heat indices of 100-105.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
-- Changed Discussion --
Issued at 633 PM CDT Wed Jun 19 2024

The main concern of the TAF period initially is lowering
ceilings moving in from the south, arriving near KLNK around
04z, fist becoming MVFR and then IFR early tomorrow morning,
with the longest period of IFR ceilings being at KOFK. Also of
concern for the period are increasing shower chances, largely in
the KOFK vicinity, largely from 10-17z where a weakening cluster
of showers moves in from the west and lingers. Lower confidence
chances at weak showers with a few strikes of lightning exist
21-00z tomorrow at KLNK and KOMA, but are currently only 20-30%
likely. Aside from the ceilings and showers, winds will shift
from the east-northeast direction currently to more of a
southeasterly direction, staying rather light at 10 kts or less.
-- End Changed Discussion --

&&

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

&&

$$

DISCUSSION...Mead
AVIATION...Petersen