Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
FXUS63 KEAX 142320

National Weather Service Kansas City/Pleasant Hill MO
620 PM CDT Thu Sep 14 2017

Issued at 243 PM CDT THU SEP 14 2017

Upper level ridging will build into the region ahead of the
deepening shortwave over the west coast.  This summer like pattern
will promote southerly flow in the low levels with nocturnal LLJ
formation through the plains nightly over the next few days.
Elevated convection is expected to develop nightly along the LLJ
over central KS and NE but with a quick developing leeside low
forming over the northern plains it will keep everything mostly to
the west of our region as the LLJ extends up into MN.  The southerly
winds will drive high temperatures into the mid to upper 80s with
some areas over NW Missouri reaching 90.  The influx of lower level
moisture will be delayed until Friday so heat index values will not
be too bad today but will jump into the 90s Friday and Saturday. The
full extent of cooler air aloft will finally push into the plains
Saturday helping to develop a cold frontal boundary extending from
MN down to central KS which will be the main weather producer during
the forecast period.

The shortwave associated with the low over MN and cold front will
track in a SW to NE orientation limiting the extend of CAA down into
our region as the frontal boundary enters MO Saturday night into
Sunday morning.  This lack of mid and upper level cold air will keep
forcing fairly weak along the cold front as it enters the region.
Soundings indicate some elevated convection may form up ahead of the
boundary along the warm sector but will lose the LLJ and forcing by
Sunday morning.  The surface cold front will push into the region
Sunday and stall around the Missouri River by mid day.  The surface
high pressure behind this boundary will quickly move W to E over the
northern plains stalling this boundary over our area Sunday into
Monday morning.  There appears to be little to no instability or
forcing to drive much precipitation Sunday along this boundary, but
some lower stratus clouds and light rain or drizzle may be possible
along this boundary making for a dreary Sunday morning and early
afternoon. The weak northerly flow and cloud coverage will keep
temperatures more near normal in the upper 70s to lower 80s for
Sunday.  A shortwave moving across the Rockies Monday will help lift
this stalled boundary back north as a warm front.  This may increase
precipitation late Sunday night into Monday morning for most of the
region north of the Missouri River.  Between .5 and 1" of
precipitation can be expected during this event with no major flood
concerns expected.

There is some uncertainty going forward with the middle of next week
as the GFS has a tropical system become post tropical and move into
our area Tuesday while the ECMWF has some tropical connection but
does not have the post tropical system moving into the region.
Because of this uncertainty the PoPs have remained relatively low
even with this signal in place.  A large cut off low is expected to
develop over western Canada during this timeframe adding some upper
support and higher mid level flow over the area with SW flow from
surface to the troposphere.  This may help to keep an active pattern
over our area from the middle to end of next week.


.Aviation...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 620 PM CDT THU SEP 14 2017

VFR conditions expected through the fcst cycle, with the only
potential concerns stemming from marginal LLWS conditions after
08z. For now, have made mention at all terminals due to veering
winds with height thanks to a strengthening low-level jet during
the predawn hours. Otherwise, no major hazards expected after
daybreak with winds expected to increase from the southwest
between 12-16 kts.




Aviation...32 is the U.S. government's official web portal to all federal, state and local government web resources and services.