Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 231145
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
545 AM CST Fri Jan 23 2015
Issued at 318 AM CST FRI JAN 23 2015
11-3.9U satellite imagery showing low clouds over eastern portions
of the CWA this morning as moisture remains trapped below a
subsidence inversion. Further to the west where clouds have
cleared...localized river valley fog has developed near STJ with the
the airport fluctuating between 1 and 3 miles during the past hour
or so. As the early morning hours progress...lingering cloud cover
should continue to dissipate/slide east as southwesterly flow
reestablishes itself over the Lwr Missouri Vly. This will occur as a
trough of low pressure approaches from the northwest today which in
essence is further attached to an area of low pressure tracking east
through south-central Canada. Developing southwest downslope flow
combined with an approaching thermal ridge in advance of the
trough should allow temps to warm well above normal this afternoon
with low 50s likely along and west of I-35. Further east...downslope
effects will be a little less noticeable which combined with any
cloud cover...should hold temps in the middle 40s.
Warm conditions to continue right into Saturday ahead of the next
northern stream wave that will track southeast across the region on
early Sunday. Quick look at 925 temp departures indicate values Sat
afternoon will be anywhere between 2-3 standard deviations above
normal as values climb to near 9C across the western zones Sat
afternoon. This should support high temps in the mid/upper 50s across
the west with low/mid 50s east of Route 65.
Well advertised wave to pass across the region Saturday night/early
Sunday...with weak cold front forcing a wind shift to the northwest
and slightly cooler conditions on Sunday. Models continue to show
best forcing well north of our area with guidance further
backtracking on expected QPF with its passage. As a result...have
"fine tuned" pops slightly based on latest model
suggestions...however wouldn/t be surprised if current fcst remains a
little overkill. Regardless...any precip should remain in the form
of rain /850 temps well above C/ and well away from the KC Metro.
Breezy conditions expected on Sunday as cold air advection continues.
Heart of coldest air to remain north and east of the area as
secondary cold front on brushes our northeast Sunday afternoon.
That said...upper 40s to lower 50s still look reasonable for now
with flow quickly backing to the southwest early Monday as initial
front lifts through the area as a warm front as low pressure skirts
across the northern Plains/upper Midwest. Again...very little if any
moisture to work with thanks to ridging across the Rio Grand Vly and
western Gulf of Mexico.
Beyond this...next major item of interest will be the warm up as
well-defined West Coast Rex block breaks down and upper ridging
slides east with time. Models eventually take large Baja California
upper low up along the northern periphery of the deamplifying ridge
axis...before ejecting it east of the Rockies on late Tuesday/early
Wednesday. If this occurs as advertised...strong thermal advection in
advance of leeside troughing will allow 850 temps of over 10C to
work north into the area as early as Wednesday afternoon. This could
easily support high temps in the lower 60s by midweek...which will be
anywhere between 20-25 degrees above normal.
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 545 AM CST FRI JAN 23 2015
MVFR restrictions at IXD and STJ will quickly improve as winds
continue to slowly increase this morning. Otherwise...VFR conditions
to dominate through the fcst period with increasing mid-level clouds
expected by late morning/early afternoon. Prevailing southwest winds
between 8-12 kts will veer to the northwest after 6z following the
passage of a weak surface boundary overnight.