Area Forecast Discussion
Issued by NWS St. Louis, MO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 44 45 46 47 48 49 50

FXUS63 KLSX 070501

1201 AM CDT WED OCT 7 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CDT Tue Oct 6 2015

Rather stagnant weather pattern continues due to an an upper level
omega block over the CONUS.  Weak high pressure over the Midwest at
the surface will remain in place through tonight.  Guidance is
inconclusive with regards to the cloud forecast for tonight, so
between that and the stagnant pattern I stuck with persistence.
Dewpoints are currently in the mid 50s to around 60, and forecast
lows tonight are expected to drop to near those values.  Expect
light wind to allow for fog to develop, although I think the
lingering cloud cover will keep the fog from getting to thick.


.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 349 PM CDT Tue Oct 6 2015

Shortwave just now moving onshore over Washington/B.C. will round
the top of the ridge over southwest Canada and dive into the Great
Plains Wednesday night.  The surface reflection of this wave will
move across the Upper Midwest into the Great Lakes region on
Thursday.  The resulting cold front will move southeast into
Missouri Thursday night.  This is slower than previous forecast, but
guidance seems to be in good agreement on this timing.  Expect
showers and thunderstorms along and ahead of the front, though am
not confident on coverage. The front will be coming through at night
which is climatologically not favorable for widespread thunderstorms
in this pattern.  Model QPF seems to agree with me as amounts are
light and somewhat spotty.  Front should clear our southeast
Missouri/south central Illinois counties by late morning/early
afternoon Friday.

Temperatures ahead of the front Wednesday and Thursday will remain
well above normal with lows in the in the mid 50s and highs 70s to
around 80. After the front passes Friday we should see temperatures
drop back to near or just below normal in the mid 60s to low 70s
with lows 45 to 50.  The surface high behind Thursday night/Friday`s
cold front will move south of the area on Sunday and the wind will
turn back around to the southwest.  Temperatures warm back up to
around 80 for next week.



.AVIATION:  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1150 PM CDT Tue Oct 6 2015

Stratus has become quite fragmented across Missouri and western
Illinois this evening yet there are still pockets of cigs from
2500-3000 ft floating across northeast and central MO. Some of
these MVFR cigs should impact KCOU and KUIN overnight and there
should be MVFR visibilities with fog as well. Otherwise some
patchy stratus and mid clouds will impact far eastern MO and
southwest Illinois overngiht with MVFR fog expected at KSUS and
KCPS. VFR conditions are expected across the entire area between
15-16z Wednesday with higher based stratocu.

Specifics for KSTL:

Patchy stratus and mid clouds will impact KSTL overnight but think VFR
conditions will prevail. Will need to monitor the potential for
some light fog - visibility dropping to 5sm or so - in the predawn
hours, but confidence is not very high. VFR conditions are
expected on Wednesday with higher based stratocu.



Saint Louis     57  79  62  86 /   0   5   5  10
Quincy          55  78  59  84 /   0   5  10  40
Columbia        56  78  58  84 /   0   5  10  10
Jefferson City  57  77  58  82 /   0   5  10  10
Salem           56  78  59  84 /   0   5   5  10
Farmington      54  76  57  82 /   0   5   5  10




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