Scientific Forecaster Discussion
fxus63 kddc 251103
Area forecast discussion
National Weather Service Dodge City Kansas
603 am CDT sun Jun 25 2017
issued at 603 am CDT sun Jun 25 2017
Based on radar and satellite trends, and using various cam
solutions as guidance, increased shower coverage closer to 30%
(scattered) for most zones through most of today.
Short term...(today and tonight)
issued at 1230 am CDT sun Jun 25 2017
Persistent mid level altostratus clouds continue this morning
across much of SW KS, beneath continued northwest flow aloft. While
moisture and instability are weak, embedded vorticity maxima in
the northwest flow keeps the occasional shower or thunderstorm possible,
as seen by the recent convective development near Goodland this
hour. Hrrr suggests northwest Kansas activity will spread into our northern
counties through sunrise, with additional storms in far SW Kansas
(near elkhart) by 4 am or so. Latest hrrr runs indicate rain
showers persisting NE of Dodge City into at least the early
afternoon hours. Really don't have a good feel where showers and
thunderstorms are more likely versus less likely, so just
broadbrushed slight chance pops everywhere through today. With
very limited instability, opted to include showers and only
isolated thunder in the grids. Certainly, no severe weather is
expected. Best chance of a stronger storm will be across the far
west near the Colorado/Kansas border this evening, where NAM increases cape
to a modest 1000 j/kg. Tweaked sky grids upward with model
forecast soundings and short term models all showing the mid layer
cloud decks near 7-9k ft persisting. Strong (for late june)
surface high (1028 mb) over central Nebraska at sunrise will
translate southeast to near Kansas City by 7 PM. While modest southerly
return flow will begin today, the general cool/dry/stable boundary
layer associated with this anticyclone will be in control for one
more day. Winds will back more sely by late in the day. With
upslope components, and continued thick mid clouds, and 850 mb
temps going virtually nowhere from yesterday, expect comfortable
high temperatures again today, within a few degrees of 80.
Showers and isolated thunderstorms remain in the forecast through
tonight, with coverage favoring the SW counties. Cloud cover will
hold temperatures in the upper 50s and lower 60s Monday morning.
Long term...(monday through saturday)
issued at 155 am CDT sun Jun 25 2017
Typical early Summer weather will prevail this week, with
temperatures returning to seasonably hot levels and daily chances
for showers and thunderstorms. Convection is possible somewhere in
SW Kansas each and every day, as shown by 00z mex guidance, with pops
at or above climatology every day through July 1st.
Monday...the warming trend begins, as the desert SW upper high
begins to weaken. Under continued northwest flow aloft, temperatures still
below normal, in the mid 80s. Instability begins to return Monday
afternoon, with 0z NAM/GFS both increasing cape into the 1500
j/kg range. Model blended pops of 20-30% are justified, highest
during peak heating.
Tuesday...subtropical upper high over the desert SW weakens
further, retreating westward out into the Pacific. This synoptic
reorientation will force more zonal flow across the Central
Plains, which in turn will sharpen Lee cyclogenesis/troughing and
allow the dryline to establish. Strong south winds expected
Tuesday, gusting easily 30-40 mph. GFS places dryline in the
vicinity of the Colorado/Kansas border at peak heating, with thunderstorms
propogating into SW Kansas Tuesday evening. With cape well in excess
of 2000 j/kg and improved bulk shear, some storms will likely be
severe with hail and/or wind potential. Pop grids favor the northwest
zones Tuesday evening, following warmer highs in the upper 80s to
lower 90s (back to late June normals).
Wednesday...thunderstorm prospects shift toward the eastern zones,
as flow aloft becomes west/SW and dryline makes further progress
eastward. Some storms east of US 283 may be severe again
Wednesday afternoon and evening. Much hotter, with all locations
well into the 90s. Hottest locales in far SW Kansas behind the dryline
will make a run for 100.
Thursday through Saturday...European model (ecmwf) shows flow aloft trending nwly
again, keeping daily thunderstorm chances alive each day, at least
somewhere in SW Kansas. GFS shows instability will remain plentiful,
and storm intensity and coverage will depend on dryline placement
and weak disturbances aloft to help with forcing. After another
hot day Thursday in the 90s, temperatures are expected to moderate
back closer to normal with a cold frontal passage and NE winds on
Aviation...(for the 12z tafs through 12z Monday morning)
issued at 600 am CDT sun Jun 25 2017
Scattered rain showers and a persistent mid layer overcast near
7k ft above ground level expected to prevail Sunday. Scattered rain showers have
already developed as of 6 am from near hys to near Scott City.
Hrrr model solutions suggest scattered showers will continue into
the early afternoon hours, tracking to the southeast. Instability
is very limited, as such expect any thunder to be isolated.
Included vcsh/thunderstorms in the vicinity in the tafs where appropriate. Expecting no
severe weather. After 15z, south winds increase modestly, with a
few gusts to near 20 kts. Winds at hys will remain more easterly.
All models show cigs lowering further after 00z Mon, perhaps down
to high end MVFR from gck to lbl.
Preliminary point temps/pops...
ddc 79 62 84 62 / 30 20 20 30
gck 77 58 84 61 / 30 30 20 30
eha 74 60 84 62 / 40 40 20 30
lbl 76 62 83 65 / 40 40 20 30
hys 76 59 82 61 / 40 30 20 20
p28 83 62 85 64 / 20 20 20 30