703
FXUS63 KGLD 191839
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1239 PM MDT Sun May 19 2024

.KEY MESSAGES...

- Severe storms remain forecasted for today with hail around
  two inches in diameter and wind gusts around 70 mph possible.

- Storms; some severe north of Interstate 70 are forecast
  Monday. Main hazards are large hail, damaging winds and
  torrential rainfall.

- Cooler with frost concerns mid week.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 244 AM MDT Sun May 19 2024

Showers and storms continue to push off to the east; some continued
isentropic lift will continue to support the potential for some
redevelopment behind the main batch of rain through at least mid
morning. Will be monitoring for some fog and stratus potential this
morning as well due to the newly saturated boundary layer and
anticipated waning winds.

The focus then turns to the severe weather potential today. A warm
front will move northward throughout the day along with a dryline
developing near the Palmer Divide during the early afternoon which
will push eastward. Currently it appears there will be 2 favored
areas for severe thunderstorm development.

1) Along the dryline in eastern Colorado and into NW Kansas/SW
Nebraska: Fairly confident in convective initation along the
dryline as CAMS have been fairly consistent with initation in
this area for the past 24 hours and HREF paintball support this
as well. The concern will be the magnitude and the coverage of
storms. Recent runs of the HRRR have backed off on the intensity
and keeps coverage to a storm or two; whereas the NAMNEST and
some MPAS guidance has more intense storms and/or develops more
of a cluster of storms. I`m continuing to favor the NAMNEST as
it has consistently done the best this spring thus far. The MPAS
guidance also does make sense as well given the clustering of
storms as overall 0-6 shear doesn`t look as impressive as last
night now showing 25-30 knots vs the 35-40 knots that was seen
last night. The 25-30 knots of bulk shear would favor more of a
cluster solution. As for hazards for this area I do think that
large to isolated very large hail and damaging winds (especially
if more of a clustering forms). Not as concerned for very large
hail as I was the past few nights given the lesser amounts of
bulk shear and the potential for more competing updrafts. That
being said if a discrete/dominant storm does form do think that
potential would be there for 2+ inch hail due to MUCAPE being
over 3000 j/kg and very steep lapse rates.

2) SE portions of the CWA (southern/eastern Wichita, southern Logan,
southern Gove counties):  signal for initation has been very
consistent with rapidly intensifying cells occurring across SW
Kansas and growing upscale as it moves ENE across Kansas. Confidence
is a bit low with how much of the CWA this will affect. Do think the
main concern with this would be damaging winds in excess of 70
mph along with some hail potential. Very good overall signal for
a bow echo to develop across East Central Kansas and into
Central Kansas; again the question will be how big of a
footprint (if any) will it have on our CWA.

Temperature wise for the day is a little tricky especially if
stratus/fog does develop and/or if cloud cover lingers. I continue
to trend in the low 80s for northeast portions of the area as this
will be the relative better chance of the above variables affecting
the temperature. A warm front will also be lifting north
through out the day, so if that does surge north a bit quicker
than anticipated each locale may be about 5 degrees to cool as
some low 90s would be in the realm of possibility. Behind the
dryline some near critical fire weather conditions still remains
possible but should be confined to western portions of Cheyenne
county Colorado. GFS forecast soundings which typically does
best with mixing potential keeps winds around 20 knots for the
duration of the afternoon; although some rogue gusts in excess
of 25 mph may be possible especially later in the afternoon,
will forego any fire highlights due to sporadic nature of the
gusts.

Sunday night into Monday morning will see another surge of moisture
from the south. Guidance is also picking up on some fog potential
within the vicinity of a developing surface low across SW Kansas,
where winds will be more light and variable. There is enough signal
for fog that have introduced patchy fog across the eastern counties
with some dense fog possible at times.

Monday will see another potential for severe weather across the
Tri- State area. A longwave trough from the SW CONUS will eject
another wave out onto the Plains during the late
afternoon/early evening hours. The main wave does look to eject
a bit further north which should keep any severe threat north of
Interstate 70 and may not even happen until after sunset. Some
large hail threat up to ping pong ball, and perhaps some tornado
threat may develop as the LLJ interacts with the developing
MCS. Very heavy rainfall does appear possible with this activity
as well with 1-1.25 PWAT value. The continued additional lift
from the LLJ may support some backbuilding potential which may
increase the excessive rainfall threat but the continued signal
for very quick Corfidi vectors should keep any flood threat to a
minimum.

Temperatures for the day appear to be a  bit challenging as status
or fog may linger through the day. Started a trend to lower
temperatures with a conshort/NAM blend to get temperatures into the
low 70s to low 80s across the area. But if the stratus indeed does
hold strong then temperatures may be about 10 degrees to warm.
Before I get that aggressive with temperatures want to see more
consistency than two models showing this.

Tuesday, a cold front looks to move across the area with another
potential for rainfall. The severe threat currently doesn`t look as
favorable mainly due to a lack of instability. Showers/storms look
to develop along and behind the front. GFS is showing a 10-15 mb
pressure rise over 3 hours which may support some strong to damaging
wind threat especially if precipitation is ongoing due to
downward momentum transfer. Continue to watch the potential for
frost across Colorado counties and perhaps as far east as the
Highway 27 corridor Wednesday morning but continues to be
dependent on quickly cloud cover does move out of the area.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 1238 PM MDT Sun May 19 2024

The latest runs of the GFS and ECMWF continue to show chances(20-
40%) for rw/trw activity. Several shortwaves set to traverse the CWA
during this time, based on current track of each system, areas north
of the area will see the best chance for convection. Both models do
show differences as to the timing and placement of convection due to
the movement of a surface low/front components, but overall the
convection will mostly occur during the evening hours. Best
instability/moisture will reside in the eastern portions of the CWA
as dewpts will range in the 40s/50s through Friday before expanding
area-wide for next weekend.

For temps, looking for near to below normal daytime highs for
Wednesday in the lower to mid 70s. Going into the remainder of the
week into next weekend, daytime highs will peak in the lower to mid
80s Thursday, with a mix of mainly 70s thereafter. Warmest locales
from Thursday onward will be south of the Interstate. Some areas
south of Highway 40 though could approach the 80F mark. These areas
will see the lowest chances for clouds/rain. Overnight lows will
range from the mid and upper 40s west into the lower to mid 50s
east. Warmest overnight areas will occur along/east of Highway
83.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1030 AM MDT Sun May 19 2024

At this time, both terminals will see a MVFR/VFR mix for
ceilings and visibility. VCTS is expected around 21z-04z for
both terminals, but with timing/placement of these storms, will
update as these develop. The passage of a front through the
area will also allow for several wind shifts through the
forecast period. Overall, basically south/southwest through
about 12z Monday, when both terminals go northerly. Overall
winds 10-15kts, but gusts to 30s kts possible, mainly this
afternoon.

&&

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

&&

$$

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