Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 040905
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
405 AM CDT FRI SEP 4 2015
Issued at 405 AM CDT FRI SEP 4 2015
Today - Sunday...
This will be a relatively benign period defined by a deep upper
trough over the western U.S. and a sharp upper ridge extending from
South Texas through far eastern MN. The upper ridge will move little
through Saturday before starting to break down and flatten Saturday
night through Sunday as the upstream trough lifts northeast and then
tracks through the Northern Plains. As a result expect the above
average temperature & humidity levels that we`ve had the last few
days to last through the weekend.
In the very short term a mid level shortwave trough from central NE
through north central KS will lift northeast this morning. Scattered
elevated convection aided by isentropic ascent on the 315K surface
will lift northeast before dissipating late this morning. The
southern edge of this convection could nick the northwest corner of
MO this morning.
Sunday Night - Wednesday...
Operational models are generating similar signals that this will be
a rather wet period with the potential for some heavy rainfall
before it`s all said and done. As the upper trough passes north of
the CWA and the upper ridge axis sags slowly south an associated
cold front will likely stall somewhere over the CWA or vacillate
north and south over northern MO before finally exiting south of the
region on Wednesday. Precipitable water values approaching 2 inches
(150-200% of normal) over the region combined with a stalled front
oriented nearly parallel to the mid/upper level flow coupled with
the development of nocturnal low level jets hints at the potential
for convection repeating over the same areas. Lots can happen over
the next 3 days to change this but regional climatology shows we
experience a secondary max of rain in September and stalled fronts
are usually one of the main ingredients.
Temperatures will be governed by the daily rain chances and cloud
cover but for now will use a more normal range of values.
Thursday - Friday...
The end of the forecast period will see a marked change from the
above average temperatures of the first week of September and the
potentially heavy rains from Sunday night through Tuesday night.
Significantly cooler and drier air is expected to force its way
southward with h8 temperatures projected to fall into the 12C-14C
range. Will have to see if the model trend of this much cooling
holds together as the surface high forecast into the Central Plains
is not particularly strong.
A slight taste of early Fall
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1202 AM CDT FRI SEP 4 2015
VFR conditions expected through the period; may see some occasional
wind gusts during the afternoon before speeds relax in the evening.
Chances for precipitation impacting terminals much lower tonight than
previous nights. Periods of high-level clouds will move across the