715
FXUS63 KGID 290545
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
1245 AM CDT Sat Jun 29 2024

.KEY MESSAGES...

- There is a Marginal (1/5) to Slight (2/5) Risk for severe
  thunderstorms this evening for the area, with wind being the
  main threat with any storms that are able to develop. A
  Marginal Risk for Excessive Rainfall has also been put out for
  the area.

- The weekend is looking pleasant with cooler temperatures and
  periodic chances (20-50%) for showers and thunderstorms mainly
  Saturday night through Sunday.

- The weekend is looking pleasant with cooler temperatures and
  periodic chances (20-50%) for showers and thunderstorms mainly
  Saturday night through Sunday.

- Areas north of Interstate 80 have been outlooked in a Day 4
  risk area for severe weather by the Storm Prediction Center.
  This will be something to keep an eye on as we get closer to
  the event.

- Independence Day will be hot with highs ranging from the
  mid-80s to low 90s. There is a 20-30% chance of showers and
  thunderstorms.

&&

.UPDATE...
Issued at 734 PM CDT Fri Jun 28 2024

-- Various thoughts on thunderstorm/severe potential through
 the rest of the evening-overnight:

- As largely expected, we have remained storm-free SO FAR this
  evening, with robust severe storms along the very leading
  edges of the synoptic cold front firing up "safely" southeast
  of our coverage area (CWA) over northeast KS. Meanwhile, any
  (so far weak) storms developing off the High Plains of the
  NE/CO/KS border area have remained well to our west.

-- Between now and roughly 2 AM:
- Obviously the MILLION DOLLAR QUESTION is whether (and to what
degree) storms and possible severe weather will impact our CWA?

- Unlike last evening (when by now it was becoming quite clear
  that we were not going to see much mainly due to stronger
  capping), tonight`s capping situation is perhaps a LITTLE
  weaker (but with 700 millibar temps still a good 12-13C).
  Otherwise, the environment is certainly supportive of at least
  isolated severe, with mixed-layer CAPE solidly 1500-2500 J/kg
  and deep-layer/effective shear 40+KT (these parameters would
  support east-southeast tracking supercells.

- Leaning on the last few HRRR runs as much as anything (usually
  a reasonable bet in the very short-term), it has trended a bit
  more aggressive with its depiction of isolated to perhaps
  scattered storms (a few severe?) invading our western counties
  9-11 PM, and then gradually weakening as they slide farther
  east into our CWA between 11 PM-2 AM. Interestingly, the HRRR
  focuses on two separate areas for greatest storm potential: 1)
  one near/south of the KS border (which seems most reasonable
  based on upstream radar trends)...2) another mainly north of
  I-80, which seems a bit more questionable but also plausible,
  as RAP forecast soundings suggest our northern zones will be
  most prone to realizing elevated instability release around
  1000 J/kg with storms based up around 750 millibars (these
  would likely be more of a hail threat with perhaps penny to
  quarter size potential). The former area near/south of the KS
  border would (in theory) pose more of a damaging wind
  threat...particularly if they organize a surging cold pool.

- PLEASE NOTE: because of residual capping/weak forcing aloft,
  it is also quite possible that storm coverage/intensity again
  "underachieves" this evening, which is why chances/PoPs have
  been intentionally held UNDER 50% at this time.

-- After roughly 2 AM:
- In one change from previous forecast, have lingered/added at
  least slight PoPs (20%) to the entire CWA through the late
  night/early-AM hours, as both HRRR/NAMNest are now more
  suggestive that at least isolated storms (possibly marginally-
  severe?) could persist especially within counties along/north
  of I-80 even through around sunrise.

- It is possible that small shower/thunderstorm chances may even
  need lingered into the official Saturday daytime forecast
  period (which starts at 7 AM) mainly in our northern zones,
  but with higher-res models suggesting that even elevated
  instability should be on a downward trend by then, will likely
  defer to overnight forecaster to decide whether this is
  warranted.

&&

.DISCUSSION...
Issued at 401 PM CDT Fri Jun 28 2024

The heat continues this afternoon across portions of south central
Nebraska and north central Kansas.  Current temperatures are
primarily in the 80s to low 90s, with a cold front pushing through
the state.  The front has moved through the Tri-Cities, with winds
mainly out of the north to northwest.  A few showers moved through
the area earlier today, with additional chances mainly after 7PM.
Thunderstorms will start across the western portions of the area,
expanding in coverage to the east as the evening progresses.  SBCAPE
of 2000+ J/kg, and MLCAPE of 1000+ J/kg are expected along with
DCAPE values of 1100+ J/kg, ML lapse rates around 7 C/km, and steep
low-level lapse rates in the west.  The main concern for any severe
weather this evening will be wind.  Some hail, an isolated tornado,
and localized flooding may also be a concern.  The Storm Prediction
Center has outlooked portions of the area for either a Marginal Risk
(1 of 5) or Slight Risk (2 of 5) for tonight.  The main areas of
concern for severe weather will be along and ahead of the front
(which includes  the southern and western portions of the area.
Additionally, the Weather Prediction Center has outlooked us in a
Marginal Risk for Excessive Rainfall for this evening.

Heading into the overnight hours, thunderstorm chances (20-30%)
persist, with strong to severe storms not expected.  The cold front
will bring in some cooler air for the weekend, making conditions
very pleasant.  Expected high temperatures will range from the mid-
70s to low 80s for Nebraska and the upper 70s to low 80s for Kansas.
 Lows will be primarily in the 50s and 60s on Sunday morning, and
the 60s on Monday morning.

As far as precipitation chances are concerned for the weekend, a few
showers and thunderstorms may linger into the morning on Saturday.
The rest of the day is looking dry, with additional showers and
thunderstorms late.  Showers and thunderstorms will be possible
again on Sunday.

Monday, an upper ridge moves to the east, with southwest flow in
place over the High Plains.  Temperatures are expected to climb with
warm air advecting into the region.  The current forecast as most
areas in Nebraska in the 90s and north central Kansas in the 90s to
around 100 degrees.  Heat index values may approach or exceed 105
degrees, which may result in heat headlines needing to be
considered.  The heat is expected to continue into Tuesday,
although, slightly cooler temperatures are expected.

Periodic shower and thunderstorm activity is expected through mid-
week.  Any one area may not see shower and thunderstorm activity
each day.  The Storm Prediction Center has put out a Day 4 Outlook
for severe weather for areas along and north of Interstate 80.  The
Weather Prediction Center has outlook the northeastern portion of
the Hastings CWA with a Marginal Risk for Excessive Rainfall.

For those planning on outdoor activities for Independence Day, there
is a 20-30% chance of showers and thunderstorms through the day.
Daytime highs are currently forecast for the mid-80s (north) to low
90s (south).  Continue to monitor the forecast for the latest
updates.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1239 AM CDT Sat Jun 29 2024

For KGRI/KEAR Airports:

VFR through the period. Could still see some iso-scat
shwrs/storms next few hrs, but then expect dry conditions from
around dawn through the end of the period. Some models have a
brief period of MVFR CIGs early this morning, but kept as a SCT
group as current obs are less aggressive. Winds will vary from
NE to NNW through the period, with highest speeds 12-14kt and
gusts 17-21kt being from mid-morning through early aftn. Light
NE winds and mainly clear skies expected Sat eve/night.
Confidence: Medium.

&&

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

&&

$$

UPDATE...Pfannkuch
DISCUSSION...Wekesser
AVIATION...Thies