039
FXUS63 KGLD 171047
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
447 AM 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 THURSDAY/...
Issued at 208 AM MDT Fri May 17 2024

The active pattern then looks to continue into the extended
period as well. Moisture looks to remain in place throughout the
day Monday. Another surface low looks to develop across SW
Kansas throughout the day Monday with the longwave trough from
the previous day ejecting out another wave. Severe weather may
again be on the table with two rounds in the realm of
possibility with the first energy ejection, then a potential MCS
or squall line moving NW to SE across the area during the
evening hours. With potentially three consecutive days of heavy
rain potential flooding may continue to pose an issue. However
again, Corfidi Vectors do not support classic widespread
flooding concerns.

Continued daily chances for showers and storms continue through the
remainder of the period. Shear thus far does continue to appear to
remain in place which suggests that some severe threat may present
itself each day; although exact location, timing, specific hazards
are to far out to say with enough certainty at this time.

Temperatures for the extended period do appear to start off near to
below normal  with highs in the 60s to 70s on Tuesday and then
slowly warming back into the 70s to 80s towards the latter portion
of the weak. A cold front, fairly strong for mid to late May looks
to move through the area Tuesday night and into Wednesday morning
dropping lows into the upper 30s to low 40s for most of the area. Do
have some concerns about clouds clearing out along with light winds
which may make it cooler. If the precipitation forecast through
Wednesday morning does pan out then some concern for frost,
especially in low lying areas mainly across eastern Colorado as
lighter winds, clear skies and ample moisture would support the
development. Confidence in frost at this time is less than 15%
as some guidance does suggest clouds and even rain continuing
Wednesday morning which would eliminate any frost threat. It is
worth mentioning however the potential as the entire area is
past its average last freeze date and most to all vegetation is
now susceptible to frost damage.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 443 AM MDT Fri May 17 2024

VFR conditions remain forecasted at each terminal. Opted to take
the LLWS out of the TAF for KGLD as the VAD wind profile is not
showing as much of a signal for it. For KMCK did leave it as the
KUEX VAD wind does continue to show the LLWS along with guidance
supporting this through at least 14Z. Winds throughout the day
will generally be WSW around 12 knots with occasional gusts up
to 20 knots as deep mixing should occur. A low chance does exist
for a pop up shower or storm along a surface convergence
boundary in between the two terminal does exist from 20-23Z;
confidence is very low in if a terminal would be affected or if
a storm is even able to develop so have opted to leave out of
the TAF but will have to be monitored through the day. Towards
the end of the period a weak, quick moving front will move
through each terminal bringing a sudden wind shift to the NW
along with another round of LLWS.

&&

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

&&

$$

SHORT TERM...Trigg
LONG TERM...Trigg
AVIATION...Trigg