Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 282122

Area Forecast Discussion
National Weather Service Saint Louis MO
322 PM CST Mon Nov 28 2016

.SHORT TERM...  (Through Late Tuesday Afternoon)
Issued at 322 PM CST Mon Nov 28 2016

Rainfall over the eastern 1/3 of the CWFA will be ending from west to
east this evening as the "cold" front passes and drier air filters
into the area.  Clouds are likewise clearing from west to east, but
are not moving out quite as fast as expected.  Latest satellite pics
show the clearing line probably getting from central Missouri to the
St. Louis Metro area by 03-04Z...and then east to our CWFA border by
07-08Z.  The RAP seems to have a decent handle on the
have used it as the basis for my cloud forecast tonight.  South to
southwest flow tonight into Tuesday isn`t exactly a cold
only expecting lows in the 40s tonight.  Additionally there
should be a decent amount of insolation on Tuesday to go along with
the southerly flow.  MOS looks reasonable with highs well above
normal again in the upper 50s to mid 60s.


.LONG TERM...  (Tuesday Night through Next Monday)
Issued at 322 PM CST Mon Nov 28 2016

(Wednesday through Friday)

Still expect Wednesday through Saturday to be mainly dry.  Both the
GFS and ECMWF are in good agreement that the upper low that will be
over the Upper Midwest on Wednesday morning will lift northeastward
through the Great Lakes and not bring any precipitation to the area.
In the meantime, zonal upper flow will setup at least through Friday
before the ECWMF and GFS begin showing diverging solutions to the
forecast over the weekend.

With polar cold front staying well south of the area during the
period and 850mb temperature staying around -5C, GEFS mean temps
support temperatures staying around normal values.

(Saturday through next Monday)

There continues to be great uncertainty with the forecast over the
weekend into early next week as the the ECMWF and the GFS are
showing different solutions.  The GFS/GFS ensemble has shown more
continuity with bringing a northern stream trough across the area
Saturday night and Sunday which would bring some light rain/snow to
the area. The ECMWF on the other hand has not shown as much run to
run consistency, with it bringing out a larger, colder system over
the weekend that would have the potential to produce more snow.
Given the consistency of the GFS, will lean more toward it`s
solution at this point.  Temperatures will continue to be close to
normal during the period.



.AVIATION...  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1145 AM CST Mon Nov 28 2016

A broad area of rain with MVFR and IFR conditions is affecting
much of southeast and east central Missouri as well as southwest
and south central Illinois. A few showers are also moving over
parts of north central and northeast Missouri. The lowest ceilings
and visibilities will likely continue to be associated with the
main area of rain this afternoon. Should see this rain move slowly
east...clearing eastern sections of the area out by KSLO by
00-01Z. Expect the MVFR deck to clear as well from west to east
through the afternoon and evening hours. VFR conditions with
south-southwest flow will prevail after the low clouds clear out.


Area of rain with primarily MVFR ceilings will continue to move
over the terminal this afternoon. There will likely be a few
breaks in the rain...but just to add a little extra complexity to
the forecast there are some IFR ceilings in the vicinity and
Lambert reported SCT009 this hour. Am covering the possibility for
an IFR ceiling with a TEMPO for now. Latest guidance shows the
rain ending at Lambert between 23-01Z this evening. Ceilings will clear
from the east by mid evening and VFR flight conditions are
expected to prevail thereafter.





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