317 
FXUS63 KLSX 192204
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
504 PM CDT Sat Apr 19 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 330 PM CDT Sat Apr 19 2014

The expansive low level ridge extending from eastern Ontario into 
the lower MS Valley will keep Gulf moisture return confined to the 
Plains tonight, and allow for continued dry and tranquil weather for 
our region. Bouts of high clouds will be the main story with 
slightly above average temperatures.

Glass

.LONG TERM:  (Sunday through Next Saturday)
Issued at 330 PM CDT Sat Apr 19 2014

Sunday will be similar to today, except a couple of degrees warmer 
due to southerly winds, and more high level cloudiness as weak 
southwest flow shortwaves move through the area.  It appears that 
the chance of showers will hold off until late Sunday night for 
central MO, and Monday for the rest of our forecast area.  The mid 
level trough now over the southwest US will move eastward through 
our area on Monday, while a strong shortwave moving through the 
northern portion of the Great Lakes region sends a cold front 
southeastward through our forecast area Monday afternoon and 
evening.  Low-mid level moisture and instability will also be 
increasing ahead of the mid level trough and surface cold front.  
This will lead to showers and a few thunderstorms Monday and Monday 
evening across our area.  Most of the showers should shift southeast 
of our forecast area by late Monday night as the mid level trough 
shifts east of the region, and the cold front shifts southeast of 
our area with colder and drier air filtering southeastward into the 
region behind the cold front late Monday night into Tuesday.  This 
cooler weather will be short lived as an upper level ridge moves 
eastward over MO on Wednesday and southerly low level winds return 
and strengthen.  The GFS model now keeps the convection on Wednesday 
and Wednesday evening, associated with strong low-mid level warm air 
advection ahead of shortwaves moving through the upper level ridge, 
north of our forecast area.  The ECMWF model has the southern edge 
of this convection skimming the extreme northern portion of our 
forecast area during this time period.  Both the GFS and ECMWF are 
fairly consistent now in bringing convection through our forecast 
area late Wednesday night through Thursday evening as the upper 
level ridge moves east of the region, while an upper level 
trough/low moves slowly eastward through the northern Plains and an 
associated surface low drags a trailing cold front southeastward 
through our area Thursday and Thursday evening.  The ECMWF model is 
a little quicker with the passage of this front through our forecast 
area compared to the GFS.  The GFS model brings colder air 
southward into our area Friday and Friday night with the upper level 
low and associated surface low moving slowly southeastward through 
the Great Lakes region.  The ECMWF model has a weaker and more 
progressive solution and keeps the colder air north of our forecast 
area.  For now will forecast cooler temperatures for Friday night 
and Saturday.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Sunday Evening)
Issued at 503 PM CDT Sat Apr 19 2014

VFR conditions expected with light southeast wind becoming south
on Easter Sunday.

Specifics for KSTL:

VFR conditions expected with light southeast wind becoming south
on Easter Sunday.

CVKING

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

$$

WFO LSX