Area Forecast Discussion
Issued by NWS St. Louis, MO
FXUS63 KLSX 082032
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
332 PM CDT THU OCT 8 2015
.SHORT TERM: (Through Late Tonight)
Issued at 332 PM CDT Thu Oct 8 2015
Looks like this will be a dry FROPA for most of the area tonight.
Short range guidance is in good agreement in developing isolated to
widely scattered showers during the early evening along and ahead of
the front. Some disagreement though as the evening wears on with
how much the showers will diminish. The NSSL and NCEP 4km WRF
models are the strongest, keeping a broken line of showers and
thunderstorms together as it moves through the CWFA from northwest
to southeast. Pretty much every other model weakens the showers and
storms through midnight tonight. Indeed, MOS PoPs are between 5-15
percent for most of the area. Have continued the trend of backing
down PoPs, and I now have 30% or less for the entire area. Cooler
air behind the front will lag behind the wind shift a bit, so I
don`t expect it to play much of a factor in lows tomorrow morning.
MOS lows in the low to mid 50s look pretty reasonable.
.LONG TERM: (Friday through Wednesday)
Issued at 305 AM CDT Thu Oct 8 2015
Same precip questions mentioned above continue into Friday
morning, perhaps into the afternoon. Trended cooler for Fri and
Sat as the sfc ridge builds into the region. Sly to swly sfc flow
returns quickly by Sun with the thermal ridge building into at
least wrn portions of the CWA into next week. Mdl solns continue
to differ slightly on timing of a dry fropa on Mon.
Overall, trended above seasonal average thru the forecast period
with the exception of Tues as the sfc ridge builds into the area.
This cooler period is expected to be brief as swly flow returns by
Wed ahead of another weak and dry fnt.
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1152 AM CDT Thu Oct 8 2015
A cold front extending from a surface low in northwestern
Wisconsin southwest through southeastern Nebraska will move
southeastward through the taf sites this evening. The cold front
should move through STL around 05Z tonight. The swly surface wind
will veer around to a nwly direction after fropa. There will
likely be a broken line of showers along and just behind this
front. For now will just include VCSH in the UIN and COU tafs for
early evening, and for the St Louis metro area late this evening
into the overnight hours as it appears that most of the showers
should be on the light side with only scattered coverage. Post
frontal low level cloudiness can be expected Friday morning,
possibly briefly dropping into the MVFR catagory.
Specifics for KSTL: Will continue with VCSH in the STL taf for
late evening into the overnight hours as scattered, mainly light
showers are expected as a cold front moves through the area. The
swly surface wind will veer around to a nwly direction late
tonight after fropa. Post frontal, low level cloudiness can be
expected on Friday, possibly dropping into the MVFR catagory for a
brief period of time.
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 60 66 50 70 / 30 20 0 0
Quincy 55 64 45 69 / 30 10 0 0
Columbia 55 66 46 72 / 30 10 0 0
Jefferson City 56 66 46 71 / 30 20 0 0
Salem 59 67 48 68 / 30 20 0 0
Farmington 57 64 47 67 / 30 30 0 0