063
FXUS63 KGID 071130
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
630 AM CDT Fri Jun 7 2024

.KEY MESSAGES...

- Rain and thunderstorms are expected to move into the area late
  this afternoon and persist into the overnight hours. Some of
  these storms may be strong to severe with isolated tornadoes,
  large hail, and damaging wind gusts all possible. Heavy
  rainfall is also possible. The entire forecast area is in a
  Slight Risk (2 out of 5) for severe thunderstorms today per
  the latest SPC outlook.

- Very warm temperatures expected today before cooler weather
  returns this weekend and early next week. Warmer weather is
  expected to return again around the middle of next week.

- There is at least a slight chance (20%) of showers and
  thunderstorms much of the forecast period (Saturday through
  next Thursday).

&&

.DISCUSSION...
Issued at 333 AM CDT Fri Jun 7 2024

Today/Tonight...

Aloft at 500 hPa, there is a trough over much of the eastern
CONUS and a weak ridge over much of the western CONUS north of a
broad area of high pressure centered over Texas and the desert
southwest this morning. At the surface, high pressure over the
MO/AR border will continue southeast and a weak low over srn UT
will push east today. There will be a chance of isolated
showers/storms this morning, but that will not be the main
concern. A pronounced shortwave trough will move across the
area this afternoon/evening, and there will be enough
instability and shear to support thunderstorms. CAPE values of
2000+ J/kg, 0-6 km shear of 50-60 kts, and strong SRH
(particularly 0-3 km values) support strong to severe storms
over at least northern and eastern portions of the forecast area.
Current expectations is for thunderstorms to initially develop
as supercells this afternoon and then evolve into a line or
lines of thunderstorms as they move southeast this evening. The
greatest large hail threat would be realized with the supercell
activity (as would the tornado risk, although that chance is
lower), and the greatest damaging wind risk would exist as the
storms become more linear. While the majority of the severe
activity is expected to be to our north and east, but there is a
lot of uncertainty regarding how far southwest into our
forecast area this reaches. The most likely timeframe for severe
storms will be around 5PM to midnight, but if storms are able
to develop further west and earlier, this activity could start
as early as 2 or 3 PM. With southerly winds bringing in a
significant increase in moisture, some areas may see heavy rain
with this system, potentially over an inch, again mainly across
northern and eastern portions of the area. Temperatures will be
very warm today with highs mainly in the upper 80s to low 90s.

Saturday - next Monday:
Temperatures will be cooler behind the front, with highs
Saturday mainly in the 70s across south central Nebraska and
into the low 80s across north central Kansas. Highs Sunday and
Monday will be in the 70s. The central Plains will be under WNW
flow aloft with embedded shortwaves through the weekend, so
there will be at least low chances (~20%) of showers and
thunderstorms, mainly Saturday. Sunday night/Monday, there is
already a fair amount of model uncertainty regarding the next
system. The ECMWF indicates an upper ridge over the area where
the GFS and NAM indicate an upper trough but guidance diverges
regarding how close the upper low is to the forecast area. Kept
PoPs low (~20%) but if models trend toward the solution that
brings the upper low into eastern Nebraska/western Iowa (GFS)
they would need to be increased.

Next Tuesday - next Thursday:

Temperatures will begin to increase going into the middle of
next week. There is still a decent spread due to the uncertainty
of the overall pattern Tuesday, but went with gradually warming
temperatures and highs mainly in the 70s. With better model
consensus indicating high pressure moving over the area mid-
week, there is more confidence regarding a return to warmer
temperatures next Wednesday and Thursday, with highs mainly in
the 80s Wednesday and into the 90s in many areas Thursday. The
area should be mostly dry, but a few thunderstorms may be
possible each evening.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 617 AM CDT Fri Jun 7 2024

VFR conditions are expected through the day Friday, with a low
chance (20%) for MVFR CIGS across the TAF sites early Saturday
morning. Showers and thunderstorms will move through the area
Friday evening into early Saturday morning.

Winds will be southerly and light through the majority of Friday
morning. Wind speeds will increase to around 15 kts sustained
with gusts to around 25 kts Friday afternoon and early evening.
Winds will be southeasterly at around 10 kts Friday evening, but
may become gusty and erratic near any thunderstorms (more likely
at KGRI than at KEAR). Winds will become easterly late this
evening, then northerly toward the end of the TAF period.

Regarding showers and thunderstorms Friday evening...strong to
severe storms are possible, but the majority of the
thunderstorm activity is expected to remain north and east of
the TAF sites. There is a little more model consensus, so
introduced -TSRA this evening for KGRI and VCTS for KEAR. There
is a 20% chance of CIGS dropping to MVFR near the end of the TAF
period, but confidence is too low to include in the TAFs.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.

&&

$$

DISCUSSION...
AVIATION...Hickford