199
FXUS63 KGID 221154
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
654 AM CDT Sat Jun 22 2024

.KEY MESSAGES...

- Primary forecast concern will center around ongoing flooding
  today as water from overnight rainfall makes its way
  downstream.

- There will be chances for mainly evening and overnight
  thunderstorms from Sunday evening through the work week with
  increasing chances during the late week period.

- Heat returns early next week. High temperatures around 100
  degrees are expected on Monday, and heat index values may
  exceed 105 degrees in some spots.

&&

.DISCUSSION...
Issued at 342 AM CDT Sat Jun 22 2024

Today (Ongoing Flooding Concerns)...

It was a busy overnight period thanks to mainly non-severe
training thunderstorms that produced heavy rainfall of 2-5
inches from Dawson County east northeastward through especially
Sherman, Howard, Merrick, Nance, and Polk Counties. The runoff
from this rainfall will gradually work its way through the
smaller creeks and streams today into our larger rivers (Mainly
the Loup) that will better be able to handle the significant
volume of water. Am planning to mainly transition the Flash
Flood Warnings within the Loup Basin to Flood Warnings this
morning and run these warnings through much of today. With only
a few river gauges it will be difficult to get a good handle on
how many creeks and rivers are still flooding until we start
getting some daylight.

We also have one isolated thunderstorm working east across
Custer County this morning, which the HRRR indicates will die
off before or shortly after entering our forecast area in
Sherman County.

After this last isolated storm dies off, likely before dawn,
then most models are dry for our forecast area over the
remainder of the day. It will be just a little cooler than
yesterday behind the cold front with northwesterly winds helping
to keep at least our Nebraska zones down in the 80s for highs
this afternoon.


Sunday (Warming Back Up Then Slight Chance For Evening
Thunderstorms)...

The winds become southerly again and warmer 90 degree heat will
return. The 06Z NAM, NAM NEST, and HRRR all develop
thunderstorms across our western zones by late Sunday
afternoon/evening, but these thunderstorms will be more driven
by diurnal heating and will have a difficult time making it very
far east into our CWA, but still could possibly reach the Tri-
Cities.


Monday (Hottest Day of the Week)...

Breezy southerly winds will lead to a hot afternoon with highs
from 97 to 103 across the forecast area and heat index values
of 100 to 105 degrees. The intense diurnal heating might be
enough to also kick off a few isolated evening thunderstorms
that should quickly die off by late evening after we lose the
diurnal heating.


Tuesday through Friday (Slightly Cooler with Increasing T-Storm
Chances)...

It will still be hot as we head through the rest of the work
week although not as bad as Monday. Weak vort maxes will rotate
through bringing mainly chances for evening/overnight
thunderstorms with a bigger upper trough coming through late
week (Thursday Night/Friday) bringing what could be our best
chance for thunderstorms although confidence is pretty low this
far out. The upper ridge should remain compressed well to our
south allowing for the continued off and on chances for
thunderstorms.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 636 AM CDT Sat Jun 22 2024

For KGRI/KEAR Airports:

We are mostly clear at the 12Z TAF issuance time, but expect low
clouds to move back in with the cold front later this morning.
We might see a brief period 1-2 hours of MVFR ceilings, but VFR
is probably more likely and thus will keep VFR ceilings in the
TAF for now. Skies will eventually clear out again by early
afternoon. The wind will switch from the southerly at TAF
issuance time, to northwesterly by later this morning behind the
frontal boundary.

&&

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

&&

$$

DISCUSSION...Wesely
AVIATION...Wesely