253
FXUS63 KGID 011742
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
1242 PM CDT Wed May 1 2024

.KEY MESSAGES...

- Severe weather remains possible today, and the peak timeframe
  for severe storms is between 6pm and 3am. Although some
  strong to marginally severe storms are possible prior to that.

- Large hail will be the primary threat with any storms that
  develop today into tonight. Isolated damaging wind gusts are
  also possible, but the threat for tornadoes has decreased for
  our local area.

- Localized flooding is also possible, mainly during the
  overnight hours tonight.

- More chances for thunderstorms through the next week,
  especially Friday night, and again Sunday night through Monday
  night.

&&

.DISCUSSION...
Issued at 427 AM CDT Wed May 1 2024

A band of rain showers stretches form NW Colorado through
central and north-central Nebraska. This activity should
continue to lift northward out of the area by sunrise or shortly
thereafter. As it does, returning moisture should allow
additional showers and thunderstorms to develop from south to
north this morning into early afternoon. These storms will have
ample shear to work with (effective shear of 40-60kts).
Instability will start off rather limited, but elevated MUCAPE
values could approach 1000 J/kg by this afternoon. As
instability increases, a few of theses storms could produce
marginally severe hail.

Looking later into the afternoon, confidence has increased that
the surface warm front (and any meaningful SBCAPE) will remain
well to our south. As such, the threat for tornadoes in the
local area has diminished.

That said, there is still considerable variance amongst the
CAMs on how exactly this evening and overnight will play out.
Some solutions develop some elevated storms in/near our KS
counties as early as 6-7pm, but others keep our area relatively
quiet until more convection develops on the LLJ and approaching
cold front overnight (9-10pm onwards).

Regardless of exact timing/evolution, the main severe threat
continues to be hail. As mentioned above, there is plenty of
shear, and MUCAPE will continue to increase through the evening,
aided by 40-50kt winds at 850mb. If storms can organize into
some west to east propagating line segments, some localized
damaging winds are possible, as well.

Additionally, the multiple rounds of thunderstorms could result
in localized excessive rain and flooding. That said, this
threat is not overly high, and the lack of consensus amongst
CAMs, reduces confidence in highlighting any specific locations.
The 00Z HREF shows only ~30% neighborhood probabilities for
2.00" or more of rain through Thursday morning, and 6-hour
flash-flood guidance is generally above 2.50" (even areas that
received heavy rain last week).

Storm intensity and coverage should start to decrease by around
3am. A few showers/storms could linger on Thursday, but most
locations will stay dry. Increasingly dry air may allow
northwestern portions of the area (especially Dawson and Valley
counties) to dip into the 30s and see some patchy frost
Thursday night.

The overall pattern remains pretty active through the weekend
and into early next week. The first time period to watch will be
Friday night into Saturday morning as a shortwave brings a
60-70% chance for rain and thunderstorms to the area.
Instability is somewhat limited, but some marginally severe
hail/wind cannot be ruled out. A stronger upper low then is
expected to push into the region late Sunday into Monday. After
today, this is the timeframe that is most favorable for severe
weather per the CSU-MLP severe probabilities.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1236 PM CDT Wed May 1 2024

Winds will generally be out of the east this afternoon with some
gusts. There is a slight chance of showers and thunderstorms
this afternoon. Low ceilings are expected at EAR beginning
around 21z and at GRI beginning around 00z. Winds will switch to
the north this evening with thunderstorm chances increasing.
Thunderstorms should end by 12z and low end VFR conditions are
expected around 16z.

&&

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

&&

$$

DISCUSSION...Mangels
AVIATION...Schuldt