Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 152242
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
542 PM CDT Tue Apr 15 2014
Issued at 406 PM CDT TUE APR 15 2014
No major systems to contend with over the next 7 days but there will
be a couple of weak features which will bring a threat of relatively
light precipitation...one on Thursday and the other Saturday
High pressure from the Great Lakes into east TX will shift quickly
east with increasingly strong southerly flow spreading west to east
tonight. A very strong low level jet with h8 winds from 50-60kt is
expected to develop from the TX Panhandle through west IA later
tonight. This swath of winds will overspread the CWA on Wednesday
with strong mixing generating sustained surface winds from 20-25kt
with gusts approaching 40kts or just below wind advisory criteria.
These winds will also draw in an elevated warm and dry mixed layer.
See Fire Weather section for details on fire weather danger.
A clipper type upper system will zip through NE/IA/MN Wednesday
night and force a cold front into the CWA. While the clipper passes
to the north the cold front will likely stall somewhere over the
CWA. Models are similar in handling a second more southern shortwave
tracking east out of CO on Thursday. Layered frontogenesis will
likely provide sufficient moist ascent to wring out some light rain.
While the GFS, which just 3 days ago had forecast a snowstorm here,
is tracking the bulk of the rain further south, even the ECMWF and
NAM have been trending further south as well. So, have trimmed back
PoPs and shifted area further south.
Friday and Saturday:
Benign weather pattern as a shortwave ridge shifts northeast with
increasing warm air advection. After a cool start on Friday we
should see seasonal or slightly warmer temperatures on Saturday.
A southern stream system with increasing isentropic ascent will
likely generate scattered convection starting as early as Saturday
night. System looks weak enough with minimal instability to preclude
a severe threat.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 542 PM CDT TUE APR 15 2014
Aviation forecast centers on the forecasted wind and subsequent
concerns for potential LLWS this evening. Current thinking is that
MCI should not decouple long enough to allow notable LLWS to develop
as strong LLJ develops later this evening. Do have a 3-h period for
LLWS at MKC/STJ based on lower elevation and climo. Gusty southerly
winds will prevail through the remainder of the forecast with cirrus
Issued at 406 PM CDT TUE APR 15 2014
As has been the case since late Winter the models appear to be over-
forecasting the surface dewpoints. The source region of this dry
airmass, the Southern High Plains into western KS, saw dewpoints from
the single digits into the middle 20s. Have gone much lower than
guidance forecast on dewpoints and potential to go even lower.
However, not enough confidence to go to extremes as a strong
southerly surface wind will be trying to draw up modified gulf
moisture. Late morning/afternoon relative humidity values at or below
25 percent, winds in the 20-30kt range plus native grasses still well
cured for the most part despite the recent heavy rains the CWA could
reach or exceed Red Flag Warning criteria. For now will issue a Fire
Weather Watch and allow the midshift to reassess the need to upgrade.
In addition, many agencies have been doing prescribed burns today
over the Flint Hills as well as parts of our western CWA, thus
justifying at least the issuance of a Watch for Wednesday.
KS...FIRE WEATHER WATCH from Wednesday morning through Wednesday
evening FOR KSZ025-057-060-102>105.
MO...FIRE WEATHER WATCH from Wednesday morning through Wednesday
evening FOR MOZ001>008-011>017-020>025-028>033-037>040-