Area Forecast Discussion
Issued by NWS St. Louis, MO
FXUS63 KLSX 151158
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
558 AM CST Sun Jan 15 2017
.SHORT TERM... (Through Late Tonight)
Issued at 349 AM CST Sun Jan 15 2017
Another wave of freezing rain developed on schedule last night
and has been spreading steadily northward into the LSX CWA early
this morning. Several locations have already reported light
glazing on elevated surfaces, including on surfaces where the ice
had melted yesterday.
With temperatures hovering near 32 F across the southern CWA and
little WAA expected through 18z, the Ice Storm Warning has been
extended until 18z for the counties which were previously set to
expire at 6am. Further updates to the Ice Storm Warning will
depend on the northward progress of the freezing line.
Most locations should rise AOA freezing this afternoon, and
temperatures will not fall much tonight due to cloudiness and WAA
at low levels after the stalled frontal boundary begins to lift
northward as a warm front. Lingering areas of light precip during
the evening hours may occasionally switch back and forth between
rain and freezing rain depending on local temperatures, but little
additional ice accretion is expected.
.LONG TERM... (Monday through Saturday)
Issued at 349 AM CST Sun Jan 15 2017
A disturbance over northwestern Mexico will lift northeastward
into the southern plains by 12z Monday. The surface reflection of
this feature will lift a stalled boundary north as a warm front,
bringing unseasonably warm temperatures to the entire CWA on
Monday. Highs on Monday are forecast to reach the mid 40s to upper
50s, which will help melt any remaining ice accretion from the
recent freezing rain event. Isolated to scattered thunderstorms
are possible on Monday aftn/eve ahead of the low pressure system`s
cold front, which is expected to move through the area on Monday
night. The post-frontal air mass does not look particularly cold,
and mild temperatures are expected for the rest of the week. Another
disturbance could bring a chance of rain to the area during the
middle or end of the week.
.AVIATION... (For the 12z TAFs through 12z Monday Morning)
Issued at 528 AM CST Sun Jan 15 2017
IFR conditions expected at all TAF sites through this period.
Freezing rain will continue through at least mid morning at both
KCOU and KSTL metro TAF sites, with freezing rain possibly mixed
with sleet at the onset moving into KUIN by around 18Z. After 15Z
to 18Z, surface temps should warm at KCOU and KSTL TAF sites to
above freezing. Ceilings will likely lower at KUIN to IFR by
around 20Z. Winds will gradually veer to east southeast during the
SPECIFICS FOR KSTL: IFR ceilings will persist through this TAF
period. Temperatures are hovering very near freezing and
observations from KSTL indicate light icing on elevated surfaces.
Freezing rain will continue through around 15Z when temperatures
finally rise above freezing. Precipitation should end by 00Z
Monday. Light northeast winds will veer to southeast by late
MO...Ice Storm Warning until noon CST today for Boone MO-Callaway MO-
Cole MO-Crawford MO-Franklin MO-Gasconade MO-Iron MO-
Jefferson MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
Reynolds MO-Saint Charles MO-Saint Francois MO-Saint Louis
City MO-Saint Louis MO-Sainte Genevieve MO-Warren MO-
Ice Storm Warning until 3 PM CST this afternoon for Audrain MO-
Lincoln MO-Monroe MO-Pike MO-Ralls MO.
Ice Storm Warning until 6 PM CST this evening for Knox MO-Lewis
MO-Marion MO-Shelby MO.
IL...Ice Storm Warning until noon CST today for Bond IL-Clinton IL-
Fayette IL-Madison IL-Marion IL-Monroe IL-Randolph IL-Saint
Clair IL-Washington IL.
Ice Storm Warning until 3 PM CST this afternoon for Calhoun IL-
Greene IL-Jersey IL-Macoupin IL-Montgomery IL-Pike IL.
Ice Storm Warning until 6 PM CST this evening for Adams IL-Brown