Area Forecast Discussion
Issued by NWS St. Louis, MO

Home | Current Version | Previous Version | Text Only | 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

000
FXUS63 KLSX 191126
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
626 AM CDT Sun Oct 19 2014

.SHORT TERM:  (Through Monday)
Issued at 317 AM CDT Sun Oct 19 2014

The Canadian high pressure center which was located overhead early
this morning will shift southeastward today. Surface winds are
forecast to become southerly to southwesterly around the back side
of the high and ahead of an approaching cold front. The
clipper-like feature which will eventually drive this cold front
through the area was still located along the Alberta/Saskatchewan
border at 19/06z, but it is forecast to deepen and amplify as it
moves into the Great Lakes region tonight and tomorrow. Models
show limited moisture being drawn into the region ahead of the
cold front, and this should be sufficient for sprinkles or light
rain showers. Even though the strongest lift will be farther to
the east, an additional source of weak lift over the southern LSX
CWA may be provided early this evening by a compact vort max
which was located near the OK panhandle this morning. This feature
looks a bit stronger on water vapor imagery than the models would
suggest, and it was already producing light radar returns across
northern OK and southern KS. Precip chances diminish quickly after
18z tomorrow due to subsidence behind the front, decreasing
moisture, and decreasing lift as the low pressure system pulls
away from the area.

Kanofsky

.LONG TERM:  (Tuesday through Saturday)
Issued at 317 AM CDT Sun Oct 19 2014

The rest of the forecast looks dry and seasonably warm through the
middle of the week. A surface ridge axis will extend southwestward
from Ontario into MO/IL while an amplified upper ridge shifts
eastward over the area. There may be a chance of rain late in the
week (Thu/Fri) if the models are correct in developing a closed
low over the southern plains and if its influence extends far
enough eastward to affect sensible wx over MO/IL.

Kanofsky

&&

.AVIATION:  (For the 12z TAFs through 12z Monday Morning)
Issued at 620 AM CDT Sun Oct 19 2014

High pressure over the area this morning producing light winds and
patchy fog primarily at locations in valleys or near rivers, i.e
SUS and CPS. Expect the fog to dissipate by 15z. The wind will
become southerly as the high shifts east and in advance of the
next cold front. Models have been trying to generate rain in
advance of the front for a couple of runs now. However not a lot
of moisture to work with, and pops still low so will leave the
forecast dry.

Specifics for KSTL: Fog has stayed away so expect a light south
southwest wind and VFR conditions to prevail through the day.
Looks like the next front will arrive about 15z Monday with a wind
shoft to the northwest. Lows pops so will keep the forecast dry
for now.

JPK

&&

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

$$

WFO LSX






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