829
FXUS63 KGLD 172021
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
221 PM MDT Fri May 17 2024

.KEY MESSAGES...

- Tranquil but warm weather continues today. A 10-15% chance of
  a thunderstorm does exist this afternoon between Goodland and
  McCook.

- Active pattern then begins Saturday night through at least mid
  week with the potential for torrential rainfall and severe
  weather nearly each day.

- Low (10-15%) chance of frost Wednesday morning currently
  favoring eastern Colorado.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 208 AM MDT Fri May 17 2024

Surface trough is moving into the area from the north bringing
some upper level cirrus along with it. WSW winds will be present
for much of the day bringing with it warm temperatures for the
entire area including some low 90s thanks in part to
downsloping. A surface convergence boundary looks to be across
the area roughly from a Goodland to McCook line this afternoon
which may bring the potential for a rogue thunderstorm along it.
Inverted v soundings will be in place across nearly the entire
area which if a storm does form think an isolated damaging wind
threat due to downbursts would be the most likely outcome.
Rainfall may be difficult to come by if something were to
develop as virga may be all that would be in play. Opted to go
silent pops (10-14%) for today due to concerns regarding virga
and if development will even occur in the first place.

Saturday will see a weak cold front clip northern portions of
the area during the morning hours with nothing but a wind shift
the NNW being the most noticeable feature with this front. A
surface high then sets up across Nebraska which will turn our
winds to the east allowing moisture advection to move into the
area. This will be important as this will help fuel evening and
overnight thunderstorms. GFS and NAM are both bullish on
moisture being available with PWATS well in excess of an inch
across the majority of the area. Despite the high PWATS think
any flooding potential will be minimal as Corfidi vectors are in
excess of 25-35 knots both upstream and downstream. With
easterly upslope flow present with ample moisture think any
flooding threat would be back building and training over certain
locales. An isolated severe storm mainly for large hail can`t
be completely ruled out especially if the NAM verifies which is
the most aggressive with MUCAPE in excess of 2000 j/kg and 0-6
shear of 35 knots.

This will all be setting the stage for Sunday. A longwave
trough will be present with an embedded wave ejecting during the
afternoon. Triple point looks to be set up across W Kansas;
guidance is not currently agreeing on the exact placement but
using the NAM which has handled similar setups fairly well thus
far this spring would put the dryline down in SW Kansas and
nearly the entire CWA in the warm sector with the warm front
draped roughly along Highway 34 in SW Nebraska. This will be
setting the stage for the areas next organized severe
thunderstorm threat. All hazards are possible, but currently am
thinking large hail, potentially in excess of 2 inches would be
the primary threat with MUCAPE in excess of 2500 j/kg, steep
lapse rates and favorable EBWD in excess of 40 knots. Hodographs
look to mainly straight line which supports hail and storm
splits. There does appear to be a slight elongation around 00Z
Monday as the LLJ increases which may be the window for any
tornado threat. Do think this would favor mainly the triple
point intersection at this time. PWATS will also be fairly high
in excess of inch which again may pose a limited hydro threat
especially if heavy rain does occur Saturday night into Sunday.
Depending on where the dryline does set up may see some fire
weather potential behind it.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 219 PM MDT Fri May 17 2024

For the long term, we are looking at daily chances for showers and
thunderstorms to move across portions of the Tri-State area. Monday
currently has the best chance, despite low to medium confidence, for
strong to severe thunderstorms across the forecast area. While an
upper trough digs south over the Western CONUS, a surface low is
expected to develop over Southwest Kansas Monday. Instability is
expected to increase during the late afternoon/evening hours, which
is the peak time for us to expect severe weather. Isolated storms
may develop ahead of a potential MCS during the evening hours.
Should the trend of an MCS continue, heavy rain and flooding would
be a concern given the potential for rain over the next two days. As
mentioned in the previous discussion widespread flooding is not
anticipated given the Corfidi Vectors; however, localized flooding
could occur.

For the remainder of the week, the upper trough will move east
across the Central CONUS and up towards the Great Lakes by Thursday
as nearly zonal flow sets up over the southern half of the country.
As stated earlier, rain and storm chances continue each
afternoon/evening as disturbances travel along the main upper level
trough. There is currently low confidence in a severe threat for the
remainder of the week but the exact location, timing, and any
specific hazards are to far out to say with enough certainty at this
time.

Near normal to slightly above normal temperatures are anticipated
next week. Temperatures on Monday are forecast to be in the upper
70s to 80s with overnight lows in the mid 40s to mid 50s. A cold
front passing through now on Tuesday will cool things off slightly
with highs in the 60s to 70s and lows in the upper 30s to 40s.
Wednesday through Friday sees a very gradual warm up across the area
as temperatures return to the mid 70s to lower 80s by Friday.
Overnight lows each of those nights will be in the 40s to lower
50s.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1100 AM MDT Fri May 17 2024

VFR conditions will rule through the TAF period, with ceilings
confined to cirrus ar or above ~12 KFT AGL. 10-15 knot SW to WSW
winds will prevail this afternoon, backing to the SSW to S
after sunset. Southerly LLWS is anticipated tonight -- in
association with the development of a 40-50 knot southerly low-
level jet ~05 UTC. Southerly LLWS will abate by sunrise -- as
surface high pressure builds southward into the region and
surface winds shift to the N at 15-25 knots (via rapid pressure
rises, ~5 mb/~3 hours). After the aforementioned pressure rises,
winds will weaken to 7-12 knots and veer to the NE (late Sat
morning) and E (Sat afternoon).. as surface high pressure
progresses eastward from Nebraska to the Iowa border.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.

&&

$$

SHORT TERM...BV
LONG TERM...KMK
AVIATION...BV