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000
FXUS63 KLSX 242011
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
211 PM CST Mon Nov 24 2014

.SHORT TERM:  (Through Tonight)
Issued at 209 PM CST Mon Nov 24 2014

Focus thru the period will be temps with no precip anticipated.

System will continue to move newd thru the period with large area of
cloud cover advecting s into the region. Mdls are in somewhat good
agreement keeping at least the nrn half of the CWA cloudy overnight.
The remainder of the CWA is more uncertain with pockets within cloud
deck that may open after sunset. Cloud cover will have a big impact
on temps tonight. Strong winds are also expected to linger longer
than prev anticipated, but gusts shud diminish by mid evening.

Taking this into consideration, have trended temps tonight slightly
warmer than prev forecast.

Tilly

.LONG TERM:  (Tonight through Sunday)
Issued at 405 AM CST Mon Nov 24 2014

System to exit region with weak surface ridge building in tonight.
Low temps will be in the low to mid 20s. Then on Tuesday ahead of
next weather system, will see southwest to west winds, but
temperatures to stay below normal in the mid 30s to low 40s.

Tuesday night, clipper system to slide southeast towards forecast
area. So will see an increase in cloud cover as well as low level
moisture. Surface low to track just west of Mississippi river on
Wednesday. So highest pops will be over eastern sections of forecast
area. Precipitation to initially start off as light snow, then as
temperatures warm up during the day on Wednesday, the snow will
become mixed with light rain and change over to mostly rain before
coming to an end Wednesday afternoon. Lows Tuesday night will be in
the mid to upper 20s while highs on Wednesday will be in the upper
30s to upper 40s.

Extended models coming into better agreement with surface ridge
building in for Thanksgiving. So will see dry and colder weather on
Thursday before warming back up for the weekend ahead of next
system. Highs on Thursday will be in the low 30s to low 40s. Still
some timing differences on frontal boundary that will slide through
late this weekend. GFS is faster with front moving through during
the day on Saturday while the ECMWF has front sliding through
Saturday night. Moisture is limited with this system, so feel that
front to move through dry despite GFS showing some light qpf. Highs
by Saturday will be near normal in the 50s, before dropping off into
the 40s on Sunday behind this system.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1133 AM CST Mon Nov 24 2014

Cigs will continue to hover near 3 kft thru the afternoon.
Confidence is higher that UIN will remain aob 3 kft thru the
afternoon. Cigs shud actually lower tonight at UIN, but confidence
is low that cigs will fall below 2 kft. Winds will be slow to
diminish this evening, but will eventually do so.

Specifics for KSTL: Cigs will remain near 3 kft thru the
afternoon, but are expected to rise and remain VFR late this
afternoon and overnight. Gusty winds will be slow to diminish this
eve.

Tilly

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     28  39  31  42 /   5   5   5  50
Quincy          22  35  26  38 /  10   5  20  60
Columbia        23  39  29  42 /   5   0  30  40
Jefferson City  24  40  28  43 /   5   0  20  30
Salem           27  37  26  41 /  10   5   0  50
Farmington      26  41  27  44 /   5   0   5  40

&&

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

$$

WFO LSX







000
FXUS63 KLSX 241748
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1148 AM CST Mon Nov 24 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 405 AM CST Mon Nov 24 2014

Precip is in the process of winding down fairly quickly over the CWA
early this morning. As it does, colder air working into the back
edge of the rain has changed the precip over to snow as far east
as a UIN-Louisiana line as of 3 am, but it appears that freezing
level is staying just high enough from COU to STL that the
changeover is struggling to occur along the I70 corridor.

Could see some very minor accumulations in the UIN area by daybreak,
but based on radar trends over the past several hours measurable
precip may be negligible after 12z. Certainly by mid morning any
precip will be quite light, and limited to the northern half of the
CWA where CAA and low level cyclonic circulation may be enough to
generate a few spits of snow.

Cold front is just now reaching our far SE counties, and the intense
CAA in its wake will be causing a bit temp drop early this morning
before readings level off this afternoon.  Elsewhere where the cold
air has already arrived, looking for a minimal rebound in temps due
to the clouds and strong cold air advection.  Best chance for any
significant warming should be limited to our far s counties where
there could be a bit of sunshine.

Truett

.LONG TERM:  (Tonight through Sunday)
Issued at 405 AM CST Mon Nov 24 2014

System to exit region with weak surface ridge building in tonight.
Low temps will be in the low to mid 20s. Then on Tuesday ahead of
next weather system, will see southwest to west winds, but
temperatures to stay below normal in the mid 30s to low 40s.

Tuesday night, clipper system to slide southeast towards forecast
area. So will see an increase in cloud cover as well as low level
moisture. Surface low to track just west of Mississippi river on
Wednesday. So highest pops will be over eastern sections of forecast
area. Precipitation to initially start off as light snow, then as
temperatures warm up during the day on Wednesday, the snow will
become mixed with light rain and change over to mostly rain before
coming to an end Wednesday afternoon. Lows Tuesday night will be in
the mid to upper 20s while highs on Wednesday will be in the upper
30s to upper 40s.

Extended models coming into better agreement with surface ridge
building in for Thanksgiving. So will see dry and colder weather on
Thursday before warming back up for the weekend ahead of next
system. Highs on Thursday will be in the low 30s to low 40s. Still
some timing differences on frontal boundary that will slide through
late this weekend. GFS is faster with front moving through during
the day on Saturday while the ECMWF has front sliding through
Saturday night. Moisture is limited with this system, so feel that
front to move through dry despite GFS showing some light qpf. Highs
by Saturday will be near normal in the 50s, before dropping off into
the 40s on Sunday behind this system.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1133 AM CST Mon Nov 24 2014

Cigs will continue to hover near 3 kft thru the afternoon.
Confidence is higher that UIN will remain aob 3 kft thru the
afternoon. Cigs shud actually lower tonight at UIN, but confidence
is low that cigs will fall below 2 kft. Winds will be slow to
diminish this evening, but will eventually do so.

Specifics for KSTL: Cigs will remain near 3 kft thru the
afternoon, but are expected to rise and remain VFR late this
afternoon and overnight. Gusty winds will be slow to diminish this
eve.

Tilly

&&

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

$$

WFO LSX







000
FXUS63 KLSX 241748
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1148 AM CST Mon Nov 24 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 405 AM CST Mon Nov 24 2014

Precip is in the process of winding down fairly quickly over the CWA
early this morning. As it does, colder air working into the back
edge of the rain has changed the precip over to snow as far east
as a UIN-Louisiana line as of 3 am, but it appears that freezing
level is staying just high enough from COU to STL that the
changeover is struggling to occur along the I70 corridor.

Could see some very minor accumulations in the UIN area by daybreak,
but based on radar trends over the past several hours measurable
precip may be negligible after 12z. Certainly by mid morning any
precip will be quite light, and limited to the northern half of the
CWA where CAA and low level cyclonic circulation may be enough to
generate a few spits of snow.

Cold front is just now reaching our far SE counties, and the intense
CAA in its wake will be causing a bit temp drop early this morning
before readings level off this afternoon.  Elsewhere where the cold
air has already arrived, looking for a minimal rebound in temps due
to the clouds and strong cold air advection.  Best chance for any
significant warming should be limited to our far s counties where
there could be a bit of sunshine.

Truett

.LONG TERM:  (Tonight through Sunday)
Issued at 405 AM CST Mon Nov 24 2014

System to exit region with weak surface ridge building in tonight.
Low temps will be in the low to mid 20s. Then on Tuesday ahead of
next weather system, will see southwest to west winds, but
temperatures to stay below normal in the mid 30s to low 40s.

Tuesday night, clipper system to slide southeast towards forecast
area. So will see an increase in cloud cover as well as low level
moisture. Surface low to track just west of Mississippi river on
Wednesday. So highest pops will be over eastern sections of forecast
area. Precipitation to initially start off as light snow, then as
temperatures warm up during the day on Wednesday, the snow will
become mixed with light rain and change over to mostly rain before
coming to an end Wednesday afternoon. Lows Tuesday night will be in
the mid to upper 20s while highs on Wednesday will be in the upper
30s to upper 40s.

Extended models coming into better agreement with surface ridge
building in for Thanksgiving. So will see dry and colder weather on
Thursday before warming back up for the weekend ahead of next
system. Highs on Thursday will be in the low 30s to low 40s. Still
some timing differences on frontal boundary that will slide through
late this weekend. GFS is faster with front moving through during
the day on Saturday while the ECMWF has front sliding through
Saturday night. Moisture is limited with this system, so feel that
front to move through dry despite GFS showing some light qpf. Highs
by Saturday will be near normal in the 50s, before dropping off into
the 40s on Sunday behind this system.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1133 AM CST Mon Nov 24 2014

Cigs will continue to hover near 3 kft thru the afternoon.
Confidence is higher that UIN will remain aob 3 kft thru the
afternoon. Cigs shud actually lower tonight at UIN, but confidence
is low that cigs will fall below 2 kft. Winds will be slow to
diminish this evening, but will eventually do so.

Specifics for KSTL: Cigs will remain near 3 kft thru the
afternoon, but are expected to rise and remain VFR late this
afternoon and overnight. Gusty winds will be slow to diminish this
eve.

Tilly

&&

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

$$

WFO LSX








000
FXUS63 KLSX 241157
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
557 AM CST Mon Nov 24 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 405 AM CST Mon Nov 24 2014

Precip is in the process of winding down fairly quickly over the CWA
early this morning. As it does, colder air working into the back
edge of the rain has changed the precip over to snow as far east
as a UIN-Louisiana line as of 3 am, but it appears that freezing
level is staying just high enough from COU to STL that the
changeover is struggling to occur along the I70 corridor.

Could see some very minor accumulations in the UIN area by daybreak,
but based on radar trends over the past several hours measurable
precip may be negligible after 12z. Certainly by mid morning any
precip will be quite light, and limited to the northern half of the
CWA where CAA and low level cyclonic circulation may be enough to
generate a few spits of snow.

Cold front is just now reaching our far SE counties, and the intense
CAA in its wake will be causing a bit temp drop early this morning
before readings level off this afternoon.  Elsewhere where the cold
air has already arrived, looking for a minimal rebound in temps due
to the clouds and strong cold air advection.  Best chance for any
significant warming should be limited to our far s counties where
there could be a bit of sunshine.

Truett

.LONG TERM:  (Tonight through Sunday)
Issued at 405 AM CST Mon Nov 24 2014

System to exit region with weak surface ridge building in tonight.
Low temps will be in the low to mid 20s. Then on Tuesday ahead of
next weather system, will see southwest to west winds, but
temperatures to stay below normal in the mid 30s to low 40s.

Tuesday night, clipper system to slide southeast towards forecast
area. So will see an increase in cloud cover as well as low level
moisture. Surface low to track just west of Mississippi river on
Wednesday. So highest pops will be over eastern sections of forecast
area. Precipitation to initially start off as light snow, then as
temperatures warm up during the day on Wednesday, the snow will
become mixed with light rain and change over to mostly rain before
coming to an end Wednesday afternoon. Lows Tuesday night will be in
the mid to upper 20s while highs on Wednesday will be in the upper
30s to upper 40s.

Extended models coming into better agreement with surface ridge
building in for Thanksgiving. So will see dry and colder weather on
Thursday before warming back up for the weekend ahead of next
system. Highs on Thursday will be in the low 30s to low 40s. Still
some timing differences on frontal boundary that will slide through
late this weekend. GFS is faster with front moving through during
the day on Saturday while the ECMWF has front sliding through
Saturday night. Moisture is limited with this system, so feel that
front to move through dry despite GFS showing some light qpf. Highs
by Saturday will be near normal in the 50s, before dropping off into
the 40s on Sunday behind this system.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Tuesday Morning)
Issued at 555 AM CST Mon Nov 24 2014

Precip has now moved east of all TAF sites in our CWA, and any
additional precip today should be limited to some spotty pockets
of light snow that form with the strongest CAA and cyclonic
curvature in the UIN area.   Primary concern for this forecast
cycle is low cloud trends and strong west winds in the wake of
last nights cold front. Upstream cloud trends suggest MVFR cigs
from 2-3kft will advect into the area this morning, and with the
cyclonic curvature and cold air aloft believe these cigs will
likely hold in most areas until late this afternoon and into the
evening, when cigs will lift into the 3-4kft range and then slowly
break up from south to north. Strong pressure gradient and deep
mixing should mean wind gusts around 30kts for most areas through
mid afternoon, and it`s certainly possible that occasionally
higher gusts will occur. However, a rapid decrease in speeds is
expected as we head towards sunset.

Specifics for KSTL: Current cigs around 1500 ft agl should lift
into the 2-3kft range by mid morning, with this cloud deck finally
scattering out by mid-late afternoon. West winds should continue
to gust to around 30kts through mid afternoon thanks to the
strong pressure gradient and deep mixing, but expect a rapid
decrease in wind speeds in the 22-01z time frame.

Truett

&&

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

$$

WFO LSX







000
FXUS63 KLSX 241008
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
408 AM CST Mon Nov 24 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 405 AM CST Mon Nov 24 2014

Precip is in the process of winding down fairly quickly over the CWA
early this morning. As it does, colder air working into the back
edge of the rain has changed the precip over to snow as far east
as a UIN-Louisiana line as of 3 am, but it appears that freezing
level is staying just high enough from COU to STL that the
changeover is struggling to occur along the I70 corridor.

Could see some very minor accumulations in the UIN area by daybreak,
but based on radar trends over the past several hours measurable
precip may be negligible after 12z. Certainly by mid morning any
precip will be quite light, and limited to the northern half of the
CWA where CAA and low level cyclonic circulation may be enough to
generate a few spits of snow.

Cold front is just now reaching our far SE counties, and the intense
CAA in its wake will be causing a bit temp drop early this morning
before readings level off this afternoon.  Elsewhere where the cold
air has already arrived, looking for a minimal rebound in temps due
to the clouds and strong cold air advection.  Best chance for any
significant warming should be limited to our far s counties where
there could be a bit of sunshine.

Truett

.LONG TERM:  (Tonight through Sunday)
Issued at 405 AM CST Mon Nov 24 2014

System to exit region with weak surface ridge building in tonight.
Low temps will be in the low to mid 20s. Then on Tuesday ahead of
next weather system, will see southwest to west winds, but
temperatures to stay below normal in the mid 30s to low 40s.

Tuesday night, clipper system to slide southeast towards forecast
area. So will see an increase in cloud cover as well as low level
moisture. Surface low to track just west of Mississippi river on
Wednesday. So highest pops will be over eastern sections of forecast
area. Precipitation to initially start off as light snow, then as
temperatures warm up during the day on Wednesday, the snow will
become mixed with light rain and change over to mostly rain before
coming to an end Wednesday afternoon. Lows Tuesday night will be in
the mid to upper 20s while highs on Wednesday will be in the upper
30s to upper 40s.

Extended models coming into better agreement with surface ridge
building in for Thanksgiving. So will see dry and colder weather on
Thursday before warming back up for the weekend ahead of next
system. Highs on Thursday will be in the low 30s to low 40s. Still
some timing differences on frontal boundary that will slide through
late this weekend. GFS is faster with front moving through during
the day on Saturday while the ECMWF has front sliding through
Saturday night. Moisture is limited with this system, so feel that
front to move through dry despite GFS showing some light qpf. Highs
by Saturday will be near normal in the 50s, before dropping off into
the 40s on Sunday behind this system.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Monday Night)
Issued at 1111 PM CST Sun Nov 23 2014

A cold front had already moved through KCOU and KUIN but had not
yet reached the St. Louis metro area TAF sites as of 05z. Expect a
marked wind shift at KSUS/KCPS when fropa occurs between 06-08z.
An area of rain was also moving northeastwards towards the TAF
sites and had already reached KCOU at TAF issuance. Rain will
persist for several more hours then taper off. The rain could
briefly mix with snow at KCOU and KUIN just as the precipitation
is ending, but upstream METARs show that the post-frontal air
mass is warmer than previously anticipated, thus accumulating
snowfall looks less likely than it did during the previous TAF
cycle. Instability snow showers are possible during the afternoon.
Winds should start to taper off once the pressure gradient relaxes
by the late afternoon or early evening.

Specifics for KSTL: Expect a marked wind shift between 06-07z when
a cold front moves through the terminal. Rain will persist for
several more hours then taper off. Instability snow showers are
possible during the afternoon. This TAF is optimistic in that it
depicts a return to VFR cigs by late afternoon/early evening.

Kanofsky
&&

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

$$
WFO LSX







000
FXUS63 KLSX 241008
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
408 AM CST Mon Nov 24 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 405 AM CST Mon Nov 24 2014

Precip is in the process of winding down fairly quickly over the CWA
early this morning. As it does, colder air working into the back
edge of the rain has changed the precip over to snow as far east
as a UIN-Louisiana line as of 3 am, but it appears that freezing
level is staying just high enough from COU to STL that the
changeover is struggling to occur along the I70 corridor.

Could see some very minor accumulations in the UIN area by daybreak,
but based on radar trends over the past several hours measurable
precip may be negligible after 12z. Certainly by mid morning any
precip will be quite light, and limited to the northern half of the
CWA where CAA and low level cyclonic circulation may be enough to
generate a few spits of snow.

Cold front is just now reaching our far SE counties, and the intense
CAA in its wake will be causing a bit temp drop early this morning
before readings level off this afternoon.  Elsewhere where the cold
air has already arrived, looking for a minimal rebound in temps due
to the clouds and strong cold air advection.  Best chance for any
significant warming should be limited to our far s counties where
there could be a bit of sunshine.

Truett

.LONG TERM:  (Tonight through Sunday)
Issued at 405 AM CST Mon Nov 24 2014

System to exit region with weak surface ridge building in tonight.
Low temps will be in the low to mid 20s. Then on Tuesday ahead of
next weather system, will see southwest to west winds, but
temperatures to stay below normal in the mid 30s to low 40s.

Tuesday night, clipper system to slide southeast towards forecast
area. So will see an increase in cloud cover as well as low level
moisture. Surface low to track just west of Mississippi river on
Wednesday. So highest pops will be over eastern sections of forecast
area. Precipitation to initially start off as light snow, then as
temperatures warm up during the day on Wednesday, the snow will
become mixed with light rain and change over to mostly rain before
coming to an end Wednesday afternoon. Lows Tuesday night will be in
the mid to upper 20s while highs on Wednesday will be in the upper
30s to upper 40s.

Extended models coming into better agreement with surface ridge
building in for Thanksgiving. So will see dry and colder weather on
Thursday before warming back up for the weekend ahead of next
system. Highs on Thursday will be in the low 30s to low 40s. Still
some timing differences on frontal boundary that will slide through
late this weekend. GFS is faster with front moving through during
the day on Saturday while the ECMWF has front sliding through
Saturday night. Moisture is limited with this system, so feel that
front to move through dry despite GFS showing some light qpf. Highs
by Saturday will be near normal in the 50s, before dropping off into
the 40s on Sunday behind this system.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Monday Night)
Issued at 1111 PM CST Sun Nov 23 2014

A cold front had already moved through KCOU and KUIN but had not
yet reached the St. Louis metro area TAF sites as of 05z. Expect a
marked wind shift at KSUS/KCPS when fropa occurs between 06-08z.
An area of rain was also moving northeastwards towards the TAF
sites and had already reached KCOU at TAF issuance. Rain will
persist for several more hours then taper off. The rain could
briefly mix with snow at KCOU and KUIN just as the precipitation
is ending, but upstream METARs show that the post-frontal air
mass is warmer than previously anticipated, thus accumulating
snowfall looks less likely than it did during the previous TAF
cycle. Instability snow showers are possible during the afternoon.
Winds should start to taper off once the pressure gradient relaxes
by the late afternoon or early evening.

Specifics for KSTL: Expect a marked wind shift between 06-07z when
a cold front moves through the terminal. Rain will persist for
several more hours then taper off. Instability snow showers are
possible during the afternoon. This TAF is optimistic in that it
depicts a return to VFR cigs by late afternoon/early evening.

Kanofsky
&&

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

$$
WFO LSX








000
FXUS63 KLSX 241008
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
408 AM CST Mon Nov 24 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 405 AM CST Mon Nov 24 2014

Precip is in the process of winding down fairly quickly over the CWA
early this morning. As it does, colder air working into the back
edge of the rain has changed the precip over to snow as far east
as a UIN-Louisiana line as of 3 am, but it appears that freezing
level is staying just high enough from COU to STL that the
changeover is struggling to occur along the I70 corridor.

Could see some very minor accumulations in the UIN area by daybreak,
but based on radar trends over the past several hours measurable
precip may be negligible after 12z. Certainly by mid morning any
precip will be quite light, and limited to the northern half of the
CWA where CAA and low level cyclonic circulation may be enough to
generate a few spits of snow.

Cold front is just now reaching our far SE counties, and the intense
CAA in its wake will be causing a bit temp drop early this morning
before readings level off this afternoon.  Elsewhere where the cold
air has already arrived, looking for a minimal rebound in temps due
to the clouds and strong cold air advection.  Best chance for any
significant warming should be limited to our far s counties where
there could be a bit of sunshine.

Truett

.LONG TERM:  (Tonight through Sunday)
Issued at 405 AM CST Mon Nov 24 2014

System to exit region with weak surface ridge building in tonight.
Low temps will be in the low to mid 20s. Then on Tuesday ahead of
next weather system, will see southwest to west winds, but
temperatures to stay below normal in the mid 30s to low 40s.

Tuesday night, clipper system to slide southeast towards forecast
area. So will see an increase in cloud cover as well as low level
moisture. Surface low to track just west of Mississippi river on
Wednesday. So highest pops will be over eastern sections of forecast
area. Precipitation to initially start off as light snow, then as
temperatures warm up during the day on Wednesday, the snow will
become mixed with light rain and change over to mostly rain before
coming to an end Wednesday afternoon. Lows Tuesday night will be in
the mid to upper 20s while highs on Wednesday will be in the upper
30s to upper 40s.

Extended models coming into better agreement with surface ridge
building in for Thanksgiving. So will see dry and colder weather on
Thursday before warming back up for the weekend ahead of next
system. Highs on Thursday will be in the low 30s to low 40s. Still
some timing differences on frontal boundary that will slide through
late this weekend. GFS is faster with front moving through during
the day on Saturday while the ECMWF has front sliding through
Saturday night. Moisture is limited with this system, so feel that
front to move through dry despite GFS showing some light qpf. Highs
by Saturday will be near normal in the 50s, before dropping off into
the 40s on Sunday behind this system.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Monday Night)
Issued at 1111 PM CST Sun Nov 23 2014

A cold front had already moved through KCOU and KUIN but had not
yet reached the St. Louis metro area TAF sites as of 05z. Expect a
marked wind shift at KSUS/KCPS when fropa occurs between 06-08z.
An area of rain was also moving northeastwards towards the TAF
sites and had already reached KCOU at TAF issuance. Rain will
persist for several more hours then taper off. The rain could
briefly mix with snow at KCOU and KUIN just as the precipitation
is ending, but upstream METARs show that the post-frontal air
mass is warmer than previously anticipated, thus accumulating
snowfall looks less likely than it did during the previous TAF
cycle. Instability snow showers are possible during the afternoon.
Winds should start to taper off once the pressure gradient relaxes
by the late afternoon or early evening.

Specifics for KSTL: Expect a marked wind shift between 06-07z when
a cold front moves through the terminal. Rain will persist for
several more hours then taper off. Instability snow showers are
possible during the afternoon. This TAF is optimistic in that it
depicts a return to VFR cigs by late afternoon/early evening.

Kanofsky
&&

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

$$
WFO LSX







000
FXUS63 KLSX 241008
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
408 AM CST Mon Nov 24 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 405 AM CST Mon Nov 24 2014

Precip is in the process of winding down fairly quickly over the CWA
early this morning. As it does, colder air working into the back
edge of the rain has changed the precip over to snow as far east
as a UIN-Louisiana line as of 3 am, but it appears that freezing
level is staying just high enough from COU to STL that the
changeover is struggling to occur along the I70 corridor.

Could see some very minor accumulations in the UIN area by daybreak,
but based on radar trends over the past several hours measurable
precip may be negligible after 12z. Certainly by mid morning any
precip will be quite light, and limited to the northern half of the
CWA where CAA and low level cyclonic circulation may be enough to
generate a few spits of snow.

Cold front is just now reaching our far SE counties, and the intense
CAA in its wake will be causing a bit temp drop early this morning
before readings level off this afternoon.  Elsewhere where the cold
air has already arrived, looking for a minimal rebound in temps due
to the clouds and strong cold air advection.  Best chance for any
significant warming should be limited to our far s counties where
there could be a bit of sunshine.

Truett

.LONG TERM:  (Tonight through Sunday)
Issued at 405 AM CST Mon Nov 24 2014

System to exit region with weak surface ridge building in tonight.
Low temps will be in the low to mid 20s. Then on Tuesday ahead of
next weather system, will see southwest to west winds, but
temperatures to stay below normal in the mid 30s to low 40s.

Tuesday night, clipper system to slide southeast towards forecast
area. So will see an increase in cloud cover as well as low level
moisture. Surface low to track just west of Mississippi river on
Wednesday. So highest pops will be over eastern sections of forecast
area. Precipitation to initially start off as light snow, then as
temperatures warm up during the day on Wednesday, the snow will
become mixed with light rain and change over to mostly rain before
coming to an end Wednesday afternoon. Lows Tuesday night will be in
the mid to upper 20s while highs on Wednesday will be in the upper
30s to upper 40s.

Extended models coming into better agreement with surface ridge
building in for Thanksgiving. So will see dry and colder weather on
Thursday before warming back up for the weekend ahead of next
system. Highs on Thursday will be in the low 30s to low 40s. Still
some timing differences on frontal boundary that will slide through
late this weekend. GFS is faster with front moving through during
the day on Saturday while the ECMWF has front sliding through
Saturday night. Moisture is limited with this system, so feel that
front to move through dry despite GFS showing some light qpf. Highs
by Saturday will be near normal in the 50s, before dropping off into
the 40s on Sunday behind this system.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Monday Night)
Issued at 1111 PM CST Sun Nov 23 2014

A cold front had already moved through KCOU and KUIN but had not
yet reached the St. Louis metro area TAF sites as of 05z. Expect a
marked wind shift at KSUS/KCPS when fropa occurs between 06-08z.
An area of rain was also moving northeastwards towards the TAF
sites and had already reached KCOU at TAF issuance. Rain will
persist for several more hours then taper off. The rain could
briefly mix with snow at KCOU and KUIN just as the precipitation
is ending, but upstream METARs show that the post-frontal air
mass is warmer than previously anticipated, thus accumulating
snowfall looks less likely than it did during the previous TAF
cycle. Instability snow showers are possible during the afternoon.
Winds should start to taper off once the pressure gradient relaxes
by the late afternoon or early evening.

Specifics for KSTL: Expect a marked wind shift between 06-07z when
a cold front moves through the terminal. Rain will persist for
several more hours then taper off. Instability snow showers are
possible during the afternoon. This TAF is optimistic in that it
depicts a return to VFR cigs by late afternoon/early evening.

Kanofsky
&&

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

$$
WFO LSX








000
FXUS63 KLSX 240531
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1131 PM CST Sun Nov 23 2014

.UPDATE:
Issued at 938 PM CST Sun Nov 23 2014

Updated the PoPs for the overnight. Sped up the timing slightly and
increased coverage to the south over the next several hrs to account
for the precip lifting out of SW MO. Limited thunder potential for a
just a few hrs this evng across the ern Ozarks. Timing on the front
still looks good with winds increasing significantly after FROPA. Not
sold on accumulating snow late tonight into early tomorrow morning due
to lack of cold enough air being advected into the area to cool the
bndry layer enough to switch over to all snow...let alone cold enough
for accums. Think that by the time cold enough air makes it into the
area the precip will be moving out. Plus...2 inch soil temps are in
the 40s across NE MO and W cntrl IL. Have not pulled the accums but
wouldn`t be surprised if there wasn`t any either.

2%

&&

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 06z TAFs through 06z Monday Night)
Issued at 1111 PM CST Sun Nov 23 2014

A cold front had already moved through KCOU and KUIN but had not
yet reached the St. Louis metro area TAF sites as of 05z. Expect a
marked wind shift at KSUS/KCPS when fropa occurs between 06-08z.
An area of rain was also moving northeastwards towards the TAF
sites and had already reached KCOU at TAF issuance. Rain will
persist for several more hours then taper off. The rain could
briefly mix with snow at KCOU and KUIN just as the precipitation
is ending, but upstream METARs show that the post-frontal air
mass is warmer than previously anticipated, thus accumulating
snowfall looks less likely than it did during the previous TAF
cycle. Instability snow showers are possible during the afternoon.
Winds should start to taper off once the pressure gradient relaxes
by the late afternoon or early evening.

Specifics for KSTL: Expect a marked wind shift between 06-07z when
a cold front moves through the terminal. Rain will persist for
several more hours then taper off. Instability snow showers are
possible during the afternoon. This TAF is optimistic in that it
depicts a return to VFR cigs by late afternoon/early evening.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 240531
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1131 PM CST Sun Nov 23 2014

.UPDATE:
Issued at 938 PM CST Sun Nov 23 2014

Updated the PoPs for the overnight. Sped up the timing slightly and
increased coverage to the south over the next several hrs to account
for the precip lifting out of SW MO. Limited thunder potential for a
just a few hrs this evng across the ern Ozarks. Timing on the front
still looks good with winds increasing significantly after FROPA. Not
sold on accumulating snow late tonight into early tomorrow morning due
to lack of cold enough air being advected into the area to cool the
bndry layer enough to switch over to all snow...let alone cold enough
for accums. Think that by the time cold enough air makes it into the
area the precip will be moving out. Plus...2 inch soil temps are in
the 40s across NE MO and W cntrl IL. Have not pulled the accums but
wouldn`t be surprised if there wasn`t any either.

2%

&&

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 06z TAFs through 06z Monday Night)
Issued at 1111 PM CST Sun Nov 23 2014

A cold front had already moved through KCOU and KUIN but had not
yet reached the St. Louis metro area TAF sites as of 05z. Expect a
marked wind shift at KSUS/KCPS when fropa occurs between 06-08z.
An area of rain was also moving northeastwards towards the TAF
sites and had already reached KCOU at TAF issuance. Rain will
persist for several more hours then taper off. The rain could
briefly mix with snow at KCOU and KUIN just as the precipitation
is ending, but upstream METARs show that the post-frontal air
mass is warmer than previously anticipated, thus accumulating
snowfall looks less likely than it did during the previous TAF
cycle. Instability snow showers are possible during the afternoon.
Winds should start to taper off once the pressure gradient relaxes
by the late afternoon or early evening.

Specifics for KSTL: Expect a marked wind shift between 06-07z when
a cold front moves through the terminal. Rain will persist for
several more hours then taper off. Instability snow showers are
possible during the afternoon. This TAF is optimistic in that it
depicts a return to VFR cigs by late afternoon/early evening.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 240347
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
947 PM CST Sun Nov 23 2014

.UPDATE:
Issued at 938 PM CST Sun Nov 23 2014

Updated the PoPs for the overnight. Sped up the timing slightly and
increased coverage to the south over the next several hrs to account
for the precip lifting out of SW MO. Limited thunder potential for a
just a few hrs this evng across the ern Ozarks. Timing on the front
still looks good with winds increasing significantly after FROPA. Not
sold on accumulating snow late tonight into early tomorrow morning due
to lack of cold enough air being advected into the area to cool the
bndry layer enough to switch over to all snow...let alone cold enough
for accums. Think that by the time cold enough air makes it into the
area the precip will be moving out. Plus...2 inch soil temps are in
the 40s across NE MO and W cntrl IL. Have not pulled the accums but
wouldn`t be surprised if there wasn`t any either.

2%

&&

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 00z TAFs through 00z Monday Evening)
Issued at 531 PM CST Sun Nov 23 2014

Specifics for KCOU, KUIN: Several issues to discuss for the 00z
TAF cycle. Continual new development of RA/DZ across central and
northern MO makes it less likely to see a substantial break in the
precip at KCOU and KUIN compared to farther south and east.
Conditions should remain IFR for the near future. The next area of
precipitation to affect KCOU and KUIN was associated with an
approaching cold front. The rain is expected to mix with and
change over to snow with minor accumulations possible (one-quarter
to one-half of an inch or less) between 08-13z. A significant wind
shift will accompany the front. Winds will become west to
northwest and increase to around 20 kts sustained with gusts of
30-35 kts. It is possible that instability snow showers may
develop tomorrow afternoon due to the very cold air aloft, but
confidence is too low to include in the TAFs at this time. This
possibility will be re-examined for the 06z issuance.

Specifics for KSTL, KSUS, KCPS: Several issues to discuss for the 00z
TAF cycle. It looks like the ongoing RA/DZ will diminish over the
next few hours (vsbys should increase at least briefly), but cigs
will probably remain IFR due to the substantial low level moisture
in place. The next area of rain to affect the metro area TAF sites
is associated with an approaching cold front. It is possible that
some of the rain may mix with snow as precipitation is ending, but
confidence is too low to introduce RASN at metro area TAF sites
yet. A significant change in winds will accompany the front
between 10-14z. Winds will become west to northwest and increase
to around 15-25 kts sustained with gusts of 30-35 kts. Finally, it
is possible that instability snow showers may develop tomorrow
afternoon due to the very cold air aloft, but confidence is too
low to include in the TAF attm.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 240347
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
947 PM CST Sun Nov 23 2014

.UPDATE:
Issued at 938 PM CST Sun Nov 23 2014

Updated the PoPs for the overnight. Sped up the timing slightly and
increased coverage to the south over the next several hrs to account
for the precip lifting out of SW MO. Limited thunder potential for a
just a few hrs this evng across the ern Ozarks. Timing on the front
still looks good with winds increasing significantly after FROPA. Not
sold on accumulating snow late tonight into early tomorrow morning due
to lack of cold enough air being advected into the area to cool the
bndry layer enough to switch over to all snow...let alone cold enough
for accums. Think that by the time cold enough air makes it into the
area the precip will be moving out. Plus...2 inch soil temps are in
the 40s across NE MO and W cntrl IL. Have not pulled the accums but
wouldn`t be surprised if there wasn`t any either.

2%

&&

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 00z TAFs through 00z Monday Evening)
Issued at 531 PM CST Sun Nov 23 2014

Specifics for KCOU, KUIN: Several issues to discuss for the 00z
TAF cycle. Continual new development of RA/DZ across central and
northern MO makes it less likely to see a substantial break in the
precip at KCOU and KUIN compared to farther south and east.
Conditions should remain IFR for the near future. The next area of
precipitation to affect KCOU and KUIN was associated with an
approaching cold front. The rain is expected to mix with and
change over to snow with minor accumulations possible (one-quarter
to one-half of an inch or less) between 08-13z. A significant wind
shift will accompany the front. Winds will become west to
northwest and increase to around 20 kts sustained with gusts of
30-35 kts. It is possible that instability snow showers may
develop tomorrow afternoon due to the very cold air aloft, but
confidence is too low to include in the TAFs at this time. This
possibility will be re-examined for the 06z issuance.

Specifics for KSTL, KSUS, KCPS: Several issues to discuss for the 00z
TAF cycle. It looks like the ongoing RA/DZ will diminish over the
next few hours (vsbys should increase at least briefly), but cigs
will probably remain IFR due to the substantial low level moisture
in place. The next area of rain to affect the metro area TAF sites
is associated with an approaching cold front. It is possible that
some of the rain may mix with snow as precipitation is ending, but
confidence is too low to introduce RASN at metro area TAF sites
yet. A significant change in winds will accompany the front
between 10-14z. Winds will become west to northwest and increase
to around 15-25 kts sustained with gusts of 30-35 kts. Finally, it
is possible that instability snow showers may develop tomorrow
afternoon due to the very cold air aloft, but confidence is too
low to include in the TAF attm.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 240347
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
947 PM CST Sun Nov 23 2014

.UPDATE:
Issued at 938 PM CST Sun Nov 23 2014

Updated the PoPs for the overnight. Sped up the timing slightly and
increased coverage to the south over the next several hrs to account
for the precip lifting out of SW MO. Limited thunder potential for a
just a few hrs this evng across the ern Ozarks. Timing on the front
still looks good with winds increasing significantly after FROPA. Not
sold on accumulating snow late tonight into early tomorrow morning due
to lack of cold enough air being advected into the area to cool the
bndry layer enough to switch over to all snow...let alone cold enough
for accums. Think that by the time cold enough air makes it into the
area the precip will be moving out. Plus...2 inch soil temps are in
the 40s across NE MO and W cntrl IL. Have not pulled the accums but
wouldn`t be surprised if there wasn`t any either.

2%

&&

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 00z TAFs through 00z Monday Evening)
Issued at 531 PM CST Sun Nov 23 2014

Specifics for KCOU, KUIN: Several issues to discuss for the 00z
TAF cycle. Continual new development of RA/DZ across central and
northern MO makes it less likely to see a substantial break in the
precip at KCOU and KUIN compared to farther south and east.
Conditions should remain IFR for the near future. The next area of
precipitation to affect KCOU and KUIN was associated with an
approaching cold front. The rain is expected to mix with and
change over to snow with minor accumulations possible (one-quarter
to one-half of an inch or less) between 08-13z. A significant wind
shift will accompany the front. Winds will become west to
northwest and increase to around 20 kts sustained with gusts of
30-35 kts. It is possible that instability snow showers may
develop tomorrow afternoon due to the very cold air aloft, but
confidence is too low to include in the TAFs at this time. This
possibility will be re-examined for the 06z issuance.

Specifics for KSTL, KSUS, KCPS: Several issues to discuss for the 00z
TAF cycle. It looks like the ongoing RA/DZ will diminish over the
next few hours (vsbys should increase at least briefly), but cigs
will probably remain IFR due to the substantial low level moisture
in place. The next area of rain to affect the metro area TAF sites
is associated with an approaching cold front. It is possible that
some of the rain may mix with snow as precipitation is ending, but
confidence is too low to introduce RASN at metro area TAF sites
yet. A significant change in winds will accompany the front
between 10-14z. Winds will become west to northwest and increase
to around 15-25 kts sustained with gusts of 30-35 kts. Finally, it
is possible that instability snow showers may develop tomorrow
afternoon due to the very cold air aloft, but confidence is too
low to include in the TAF attm.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 240347
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
947 PM CST Sun Nov 23 2014

.UPDATE:
Issued at 938 PM CST Sun Nov 23 2014

Updated the PoPs for the overnight. Sped up the timing slightly and
increased coverage to the south over the next several hrs to account
for the precip lifting out of SW MO. Limited thunder potential for a
just a few hrs this evng across the ern Ozarks. Timing on the front
still looks good with winds increasing significantly after FROPA. Not
sold on accumulating snow late tonight into early tomorrow morning due
to lack of cold enough air being advected into the area to cool the
bndry layer enough to switch over to all snow...let alone cold enough
for accums. Think that by the time cold enough air makes it into the
area the precip will be moving out. Plus...2 inch soil temps are in
the 40s across NE MO and W cntrl IL. Have not pulled the accums but
wouldn`t be surprised if there wasn`t any either.

2%

&&

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 00z TAFs through 00z Monday Evening)
Issued at 531 PM CST Sun Nov 23 2014

Specifics for KCOU, KUIN: Several issues to discuss for the 00z
TAF cycle. Continual new development of RA/DZ across central and
northern MO makes it less likely to see a substantial break in the
precip at KCOU and KUIN compared to farther south and east.
Conditions should remain IFR for the near future. The next area of
precipitation to affect KCOU and KUIN was associated with an
approaching cold front. The rain is expected to mix with and
change over to snow with minor accumulations possible (one-quarter
to one-half of an inch or less) between 08-13z. A significant wind
shift will accompany the front. Winds will become west to
northwest and increase to around 20 kts sustained with gusts of
30-35 kts. It is possible that instability snow showers may
develop tomorrow afternoon due to the very cold air aloft, but
confidence is too low to include in the TAFs at this time. This
possibility will be re-examined for the 06z issuance.

Specifics for KSTL, KSUS, KCPS: Several issues to discuss for the 00z
TAF cycle. It looks like the ongoing RA/DZ will diminish over the
next few hours (vsbys should increase at least briefly), but cigs
will probably remain IFR due to the substantial low level moisture
in place. The next area of rain to affect the metro area TAF sites
is associated with an approaching cold front. It is possible that
some of the rain may mix with snow as precipitation is ending, but
confidence is too low to introduce RASN at metro area TAF sites
yet. A significant change in winds will accompany the front
between 10-14z. Winds will become west to northwest and increase
to around 15-25 kts sustained with gusts of 30-35 kts. Finally, it
is possible that instability snow showers may develop tomorrow
afternoon due to the very cold air aloft, but confidence is too
low to include in the TAF attm.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 240003
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
603 PM CST Sun Nov 23 2014

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 00z TAFs through 00z Monday Evening)
Issued at 531 PM CST Sun Nov 23 2014

Specifics for KCOU, KUIN: Several issues to discuss for the 00z
TAF cycle. Continual new development of RA/DZ across central and
northern MO makes it less likely to see a substantial break in the
precip at KCOU and KUIN compared to farther south and east.
Conditions should remain IFR for the near future. The next area of
precipitation to affect KCOU and KUIN was associated with an
approaching cold front. The rain is expected to mix with and
change over to snow with minor accumulations possible (one-quarter
to one-half of an inch or less) between 08-13z. A significant wind
shift will accompany the front. Winds will become west to
northwest and increase to around 20 kts sustained with gusts of
30-35 kts. It is possible that instability snow showers may
develop tomorrow afternoon due to the very cold air aloft, but
confidence is too low to include in the TAFs at this time. This
possibility will be re-examined for the 06z issuance.

Specifics for KSTL, KSUS, KCPS: Several issues to discuss for the 00z
TAF cycle. It looks like the ongoing RA/DZ will diminish over the
next few hours (vsbys should increase at least briefly), but cigs
will probably remain IFR due to the substantial low level moisture
in place. The next area of rain to affect the metro area TAF sites
is associated with an approaching cold front. It is possible that
some of the rain may mix with snow as precipitation is ending, but
confidence is too low to introduce RASN at metro area TAF sites
yet. A significant change in winds will accompany the front
between 10-14z. Winds will become west to northwest and increase
to around 15-25 kts sustained with gusts of 30-35 kts. Finally, it
is possible that instability snow showers may develop tomorrow
afternoon due to the very cold air aloft, but confidence is too
low to include in the TAF attm.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 240003
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
603 PM CST Sun Nov 23 2014

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 00z TAFs through 00z Monday Evening)
Issued at 531 PM CST Sun Nov 23 2014

Specifics for KCOU, KUIN: Several issues to discuss for the 00z
TAF cycle. Continual new development of RA/DZ across central and
northern MO makes it less likely to see a substantial break in the
precip at KCOU and KUIN compared to farther south and east.
Conditions should remain IFR for the near future. The next area of
precipitation to affect KCOU and KUIN was associated with an
approaching cold front. The rain is expected to mix with and
change over to snow with minor accumulations possible (one-quarter
to one-half of an inch or less) between 08-13z. A significant wind
shift will accompany the front. Winds will become west to
northwest and increase to around 20 kts sustained with gusts of
30-35 kts. It is possible that instability snow showers may
develop tomorrow afternoon due to the very cold air aloft, but
confidence is too low to include in the TAFs at this time. This
possibility will be re-examined for the 06z issuance.

Specifics for KSTL, KSUS, KCPS: Several issues to discuss for the 00z
TAF cycle. It looks like the ongoing RA/DZ will diminish over the
next few hours (vsbys should increase at least briefly), but cigs
will probably remain IFR due to the substantial low level moisture
in place. The next area of rain to affect the metro area TAF sites
is associated with an approaching cold front. It is possible that
some of the rain may mix with snow as precipitation is ending, but
confidence is too low to introduce RASN at metro area TAF sites
yet. A significant change in winds will accompany the front
between 10-14z. Winds will become west to northwest and increase
to around 15-25 kts sustained with gusts of 30-35 kts. Finally, it
is possible that instability snow showers may develop tomorrow
afternoon due to the very cold air aloft, but confidence is too
low to include in the TAF attm.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 232155
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
355 PM CST Sun Nov 23 2014

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1133 AM CST Sun Nov 23 2014

Widespread high-end IFR ceilings will be the rule at all TAF sites
through the day and into tonight. Visibilities may also dip into
high-end IFR range at times with heavier rain, particularly before
00Z. Surface low pressure will track just northwest of region
tonight, with winds becoming west to southwest. Arctic high
pressure then rapidly build in behind main cold front from 06Z to
12Z Monday. Remaining precipitation should mix with then change to snow
before ending at KUIN and KCOU TAF sites Monday morning, however
drier air arrives to the south over metro St. Louis area just as
temperatures get cold enough to support snow at the surface. A few
flakes may mix in there as well, but it should not be significant
so have not included in this set of TAFS. West winds will become
strong behind arctic front Monday morning and will likely gust
into the 25-30 knot range. Ceilings should improve into MVFR range
behind the front as well. As temperatures throughout the column
continue to cool during the day, some brief snowshowers are
possible Monday afternoon.

Specifics for KSTL: IFR ceilings will likely last though the
night, with periods of IFR visibilities this afternoon in pockets
of heavier rain. Main cold front moves in around 12Z Monday, but
atmosphere dries out by then in critical cloud layer cold enough
to form snow, so the precipitation should shut off by then. Post
frontal winds will be a factor, and will gust in the 25 to 30 knot
range after 12Z Monday. MVFR ceilings behind cold front will
likely last through this TAF period.

Browning

&&

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

$$

WFO LSX








000
FXUS63 KLSX 232155
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
355 PM CST Sun Nov 23 2014

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1133 AM CST Sun Nov 23 2014

Widespread high-end IFR ceilings will be the rule at all TAF sites
through the day and into tonight. Visibilities may also dip into
high-end IFR range at times with heavier rain, particularly before
00Z. Surface low pressure will track just northwest of region
tonight, with winds becoming west to southwest. Arctic high
pressure then rapidly build in behind main cold front from 06Z to
12Z Monday. Remaining precipitation should mix with then change to snow
before ending at KUIN and KCOU TAF sites Monday morning, however
drier air arrives to the south over metro St. Louis area just as
temperatures get cold enough to support snow at the surface. A few
flakes may mix in there as well, but it should not be significant
so have not included in this set of TAFS. West winds will become
strong behind arctic front Monday morning and will likely gust
into the 25-30 knot range. Ceilings should improve into MVFR range
behind the front as well. As temperatures throughout the column
continue to cool during the day, some brief snowshowers are
possible Monday afternoon.

Specifics for KSTL: IFR ceilings will likely last though the
night, with periods of IFR visibilities this afternoon in pockets
of heavier rain. Main cold front moves in around 12Z Monday, but
atmosphere dries out by then in critical cloud layer cold enough
to form snow, so the precipitation should shut off by then. Post
frontal winds will be a factor, and will gust in the 25 to 30 knot
range after 12Z Monday. MVFR ceilings behind cold front will
likely last through this TAF period.

Browning

&&

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

$$

WFO LSX







000
FXUS63 KLSX 232155
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
355 PM CST Sun Nov 23 2014

.SHORT TERM: (Through Monday)
Issued at 346 PM CST Sun Nov 23 2014

Main concern for tonight will be will there be any snow accumulation
over northwestern parts of the area as rain changes to snow behind a
sharp cold front. Most of the CWA has seen rain today and the
current band which is being forced by strong moisture convergence
and strong ascent ahead of ejecting shortwave trough will move
northeast of the CWA this evening. This will cause a lull in the
precipitation this evening before a second area currently over the
Plains moves into the area later this evening and overnight. This
area is being frontogenetically forced ahead of a second trough
currently over the northern Plains. Attendant cold front that
currently extends across central Iowa into far northwest Missouri
into eastern Kansas will push eastward this evening, reaching St.
Louis by midnight and east of the CWA by 3 am. Forecast soundings
suggest that the rain will mix with and then changeover to snow
after midnight before the frontogenetical band lifts out between
midnight and 6 am. Current indications are that snowfall amounts
will be less than 1 inch along and north of a Shelbina to Quincy
line given the relatively warm soil temperatures (Novelty Missouri
Mesonet 2 inch soil temperature is currently 50 degrees) and the
relative short amount of time that the accumulating snow will
fall. It will be windy late tonight into tomorrow as decent
gradient winds set up behind the cold front. However it does not
appear that we will hit advisory criteria at this time.

Do not expect much clearing tomorrow as forecast soundings show some
minimal CAPE in the lowest levels tomorrow afternoon suggesting some
isolated snow or rain showers will develop in the low level cyclonic
flow. Highs tomorrow are only a few degrees warmer than lows tonight.

Britt

.LONG TERM:  (Monday Night through Next Sunday)
Issued at 346 PM CST Sun Nov 23 2014

(Monday night through Wednesday)

Next notable trough that will move through the area will be on
Wednesday which the ECMWF and GFS both show light QPF across the
CWA. Have increased PoPs a bit across the area, with the highest
amounts over the northern CWA where current track of the surface
low will be. Temperatures will stay below normal during the period.

(Thursday through next Sunday)

Overall confidence in forecast during this period is not high as the
both operational GFS and ECMWF and their ensembles have had continuity
issues the past few days with the timing and strength of the troughs
that will move across the area later this week. Latest runs are showing
quasi-zonal flow during the period with shortwave troughs moving quickly
across the area. While the GFS is developing some QPF over the region
on Saturday, this is different than yesterday`s run, so will discount
for now. Will go dry during this period given the inherent difficulties
in timing precipitation in zonal flow.

Britt

&&

.AVIATION:  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1133 AM CST Sun Nov 23 2014

Widespread high-end IFR ceilings will be the rule at all TAF sites
through the day and into tonight. Visibilities may also dip into
high-end IFR range at times with heavier rain, particularly before
00Z. Surface low pressure will track just northwest of region
tonight, with winds becoming west to southwest. Arctic high
pressure then rapidly build in behind main cold front from 06Z to
12Z Monday. Remaining precipitation should mix with then change to snow
before ending at KUIN and KCOU TAF sites Monday morning, however
drier air arrives to the south over metro St. Louis area just as
temperatures get cold enough to support snow at the surface. A few
flakes may mix in there as well, but it should not be significant
so have not included in this set of TAFS. West winds will become
strong behind arctic front Monday morning and will likely gust
into the 25-30 knot range. Ceilings should improve into MVFR range
behind the front as well. As temperatures throughout the column
continue to cool during the day, some brief snowshowers are
possible Monday afternoon.

Specifics for KSTL: IFR ceilings will likely last though the
night, with periods of IFR visibilities this afternoon in pockets
of heavier rain. Main cold front moves in around 12Z Monday, but
atmosphere dries out by then in critical cloud layer cold enough
to form snow, so the precipitation should shut off by then. Post
frontal winds will be a factor, and will gust in the 25 to 30 knot
range after 12Z Monday. MVFR ceilings behind cold front will
likely last through this TAF period.

Browning

&&

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

$$

WFO LSX







000
FXUS63 KLSX 231755
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1155 AM CST Sun Nov 23 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 331 AM CST Sun Nov 23 2014

Surface low to begin lifting northeastward towards forecast area
today. Will see showers on the increase this morning and spread
north across the region. Some instability today so there is a chance
of thunderstorms mainly along and south of I-70.  As for
temperatures, will depend on cloud cover and rainfall. But feel that
temps will rise into the mid 50s to low 60s by this afternoon.

Byrd

.LONG TERM:  (Tonight through Saturday)
Issued at 331 AM CST Sun Nov 23 2014

(Tonight-Wednesday)

While specific precip trends are certainly tricky tonight and into
Monday, latest synoptic and hi-res guidance suggests the general
scenario will be that this afternoon`s band of rain and embedded
thunderstorms will rotate east out of the area this evening, as
additional precip begins to form to our west as secondary shortwave
drops south in the wake of today`s system.  This secondary area of
precip should then wind down to spotty areas of light rain/light
snow during the day on Monday.

Yesterday`s guidance as well as 00z model output is now suggesting
more precip lingering in the cold air late tonight and early Monday
than was indicated by earlier runs.  I have not made any major
changes to the timing of the changeover from rain to snow over the
northwest half of the CWA in the 06-12z time frame; this may be a
bit too fast, but didn`t want to discount the intensity of the
CAA. In the far NW counties, it appears that this strong CAA will
cause freezing levels to drop enough to support the rain changing
over to all snow for a few hours late tonight and into early
Monday morning, and based on this have added some minor accumulations
of under an inch in our extreme northwest counties.

Min/max temps for tonight/Monday will be based on non-diurnal, 3
hourly temp trends during this time frame.

No major changes in going forecast trends heading into midweek, with
dry and chlly weather on Tuesday followed by a brief warmup and low
PoPs for the fast-moving, moisture-starved system on Wednesday.

(Thursday-Saturday)

Medium range guidance has come into better agreement with a less
amplified solution for Thanksgiving Day, suggesting a ribbon of
light precip over northern sections of the CWA as shortwave
interacts with baroclinicity that is draped across the region.
Pattern suggests that there should be a strong temperature
gradient from north to south across the region, with highs in the
30s over the cold air in the north while approaching 50 in the
warmer air over southern sections of the CWA.

This agreement jumps the tracks heading into the latter half of the
week, with GEM and ECMWF forecasting broad trofing over the central
CONUS while the GFS maintains a more quasi-zonal look.  Of course,
given the intensity of the baroclinic zone this somewhat subtle
difference will make a huge impact on sensible weather trends, and
especially on temperatures.  This discrepency can be seen in the
surface prog forecasts for Friday morning; ECMWF and GEM have broad
and cold Canadian high over the plains and into the upper
Mississippi Valley with north/northeast winds over our FA, while GFS
as surface low over the northern plains and southerly winds over our
area.  MOS guidance based on these solutions offer a more
quanitative and stark measure of this discrepency...a whopping
20-25 degree difference on Friday`s highs between the colder
ECMWF and warmer GFS. For now have maintained earlier (colder)
trends, based on consensus of GEM and ECMEF.

Truett

&&

.AVIATION:  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1133 AM CST Sun Nov 23 2014

Widespread high-end IFR ceilings will be the rule at all TAF sites
through the day and into tonight. Visibilities may also dip into
high-end IFR range at times with heavier rain, particularly before
00Z. Surface low pressure will track just northwest of region
tonight, with winds becoming west to southwest. Arctic high
pressure then rapidly build in behind main cold front from 06Z to
12Z Monday. Remaining precipitation should mix with then change to snow
before ending at KUIN and KCOU TAF sites Monday morning, however
drier air arrives to the south over metro St. Louis area just as
temperatures get cold enough to support snow at the surface. A few
flakes may mix in there as well, but it should not be significant
so have not included in this set of TAFS. West winds will become
strong behind arctic front Monday morning and will likely gust
into the 25-30 knot range. Ceilings should improve into MVFR range
behind the front as well. As temperatures throughout the column
continue to cool during the day, some brief snowshowers are
possible Monday afternoon.

Specifics for KSTL: IFR ceilings will likely last though the
night, with periods of IFR visibilities this afternoon in pockets
of heavier rain. Main cold front moves in around 12Z Monday, but
atmosphere dries out by then in critical cloud layer cold enough
to form snow, so the precipitation should shut off by then. Post
frontal winds will be a factor, and will gust in the 25 to 30 knot
range after 12Z Monday. MVFR ceilings behind cold front will
likely last through this TAF period.

Browning

&&

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

$$

WFO LSX







000
FXUS63 KLSX 231755
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1155 AM CST Sun Nov 23 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 331 AM CST Sun Nov 23 2014

Surface low to begin lifting northeastward towards forecast area
today. Will see showers on the increase this morning and spread
north across the region. Some instability today so there is a chance
of thunderstorms mainly along and south of I-70.  As for
temperatures, will depend on cloud cover and rainfall. But feel that
temps will rise into the mid 50s to low 60s by this afternoon.

Byrd

.LONG TERM:  (Tonight through Saturday)
Issued at 331 AM CST Sun Nov 23 2014

(Tonight-Wednesday)

While specific precip trends are certainly tricky tonight and into
Monday, latest synoptic and hi-res guidance suggests the general
scenario will be that this afternoon`s band of rain and embedded
thunderstorms will rotate east out of the area this evening, as
additional precip begins to form to our west as secondary shortwave
drops south in the wake of today`s system.  This secondary area of
precip should then wind down to spotty areas of light rain/light
snow during the day on Monday.

Yesterday`s guidance as well as 00z model output is now suggesting
more precip lingering in the cold air late tonight and early Monday
than was indicated by earlier runs.  I have not made any major
changes to the timing of the changeover from rain to snow over the
northwest half of the CWA in the 06-12z time frame; this may be a
bit too fast, but didn`t want to discount the intensity of the
CAA. In the far NW counties, it appears that this strong CAA will
cause freezing levels to drop enough to support the rain changing
over to all snow for a few hours late tonight and into early
Monday morning, and based on this have added some minor accumulations
of under an inch in our extreme northwest counties.

Min/max temps for tonight/Monday will be based on non-diurnal, 3
hourly temp trends during this time frame.

No major changes in going forecast trends heading into midweek, with
dry and chlly weather on Tuesday followed by a brief warmup and low
PoPs for the fast-moving, moisture-starved system on Wednesday.

(Thursday-Saturday)

Medium range guidance has come into better agreement with a less
amplified solution for Thanksgiving Day, suggesting a ribbon of
light precip over northern sections of the CWA as shortwave
interacts with baroclinicity that is draped across the region.
Pattern suggests that there should be a strong temperature
gradient from north to south across the region, with highs in the
30s over the cold air in the north while approaching 50 in the
warmer air over southern sections of the CWA.

This agreement jumps the tracks heading into the latter half of the
week, with GEM and ECMWF forecasting broad trofing over the central
CONUS while the GFS maintains a more quasi-zonal look.  Of course,
given the intensity of the baroclinic zone this somewhat subtle
difference will make a huge impact on sensible weather trends, and
especially on temperatures.  This discrepency can be seen in the
surface prog forecasts for Friday morning; ECMWF and GEM have broad
and cold Canadian high over the plains and into the upper
Mississippi Valley with north/northeast winds over our FA, while GFS
as surface low over the northern plains and southerly winds over our
area.  MOS guidance based on these solutions offer a more
quanitative and stark measure of this discrepency...a whopping
20-25 degree difference on Friday`s highs between the colder
ECMWF and warmer GFS. For now have maintained earlier (colder)
trends, based on consensus of GEM and ECMEF.

Truett

&&

.AVIATION:  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1133 AM CST Sun Nov 23 2014

Widespread high-end IFR ceilings will be the rule at all TAF sites
through the day and into tonight. Visibilities may also dip into
high-end IFR range at times with heavier rain, particularly before
00Z. Surface low pressure will track just northwest of region
tonight, with winds becoming west to southwest. Arctic high
pressure then rapidly build in behind main cold front from 06Z to
12Z Monday. Remaining precipitation should mix with then change to snow
before ending at KUIN and KCOU TAF sites Monday morning, however
drier air arrives to the south over metro St. Louis area just as
temperatures get cold enough to support snow at the surface. A few
flakes may mix in there as well, but it should not be significant
so have not included in this set of TAFS. West winds will become
strong behind arctic front Monday morning and will likely gust
into the 25-30 knot range. Ceilings should improve into MVFR range
behind the front as well. As temperatures throughout the column
continue to cool during the day, some brief snowshowers are
possible Monday afternoon.

Specifics for KSTL: IFR ceilings will likely last though the
night, with periods of IFR visibilities this afternoon in pockets
of heavier rain. Main cold front moves in around 12Z Monday, but
atmosphere dries out by then in critical cloud layer cold enough
to form snow, so the precipitation should shut off by then. Post
frontal winds will be a factor, and will gust in the 25 to 30 knot
range after 12Z Monday. MVFR ceilings behind cold front will
likely last through this TAF period.

Browning

&&

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

$$

WFO LSX








000
FXUS63 KLSX 231228
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
628 AM CST Sun Nov 23 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 331 AM CST Sun Nov 23 2014

Surface low to begin lifting northeastward towards forecast area
today. Will see showers on the increase this morning and spread
north across the region. Some instability today so there is a chance
of thunderstorms mainly along and south of I-70.  As for
temperatures, will depend on cloud cover and rainfall. But feel that
temps will rise into the mid 50s to low 60s by this afternoon.

Byrd

.LONG TERM:  (Tonight through Saturday)
Issued at 331 AM CST Sun Nov 23 2014

(Tonight-Wednesday)

While specific precip trends are certainly tricky tonight and into
Monday, latest synoptic and hi-res guidance suggests the general
scenario will be that this afternoon`s band of rain and embedded
thunderstorms will rotate east out of the area this evening, as
additional precip begins to form to our west as secondary shortwave
drops south in the wake of today`s system.  This secondary area of
precip should then wind down to spotty areas of light rain/light
snow during the day on Monday.

Yesterday`s guidance as well as 00z model output is now suggesting
more precip lingering in the cold air late tonight and early Monday
than was indicated by earlier runs.  I have not made any major
changes to the timing of the changeover from rain to snow over the
northwest half of the CWA in the 06-12z time frame; this may be a
bit too fast, but didn`t want to discount the intensity of the
CAA. In the far NW counties, it appears that this strong CAA will
cause freezing levels to drop enough to support the rain changing
over to all snow for a few hours late tonight and into early
Monday morning, and based on this have added some minor accumulations
of under an inch in our extreme northwest counties.

Min/max temps for tonight/Monday will be based on non-diurnal, 3
hourly temp trends during this time frame.

No major changes in going forecast trends heading into midweek, with
dry and chlly weather on Tuesday followed by a brief warmup and low
PoPs for the fast-moving, moisture-starved system on Wednesday.

(Thursday-Saturday)

Medium range guidance has come into better agreement with a less
amplified solution for Thanksgiving Day, suggesting a ribbon of
light precip over northern sections of the CWA as shortwave
interacts with baroclinicity that is draped across the region.
Pattern suggests that there should be a strong temperature
gradient from north to south across the region, with highs in the
30s over the cold air in the north while approaching 50 in the
warmer air over southern sections of the CWA.

This agreement jumps the tracks heading into the latter half of the
week, with GEM and ECMWF forecasting broad trofing over the central
CONUS while the GFS maintains a more quasi-zonal look.  Of course,
given the intensity of the baroclinic zone this somewhat subtle
difference will make a huge impact on sensible weather trends, and
especially on temperatures.  This discrepency can be seen in the
surface prog forecasts for Friday morning; ECMWF and GEM have broad
and cold Canadian high over the plains and into the upper
Mississippi Valley with north/northeast winds over our FA, while GFS
as surface low over the northern plains and southerly winds over our
area.  MOS guidance based on these solutions offer a more
quanitative and stark measure of this discrepency...a whopping
20-25 degree difference on Friday`s highs between the colder
ECMWF and warmer GFS. For now have maintained earlier (colder)
trends, based on consensus of GEM and ECMEF.

Truett
&&

.AVIATION:  (For the 12z TAFs through 12z Monday Morning)
Issued at 628 AM CST Sun Nov 23 2014

Next round of showers continuing to develop and slide northward
through forecast area and persist through most of forecast period.
Cigs to lower to mvfr by mid morning, then down to ifr. In the
meantime, winds to persist from the southeast to south today. As
surface low lifts through region, cold front associated with it to
slide through area tonight. Front to move through KCOU by 03z
Monday, KUIN by 04z Monday and metro area tafs by 07z Monday.
Winds to veer to the west behind from and become gusty at times.
Colder air will filter on back side of system with rain becoming
mixed with snow after midnight tonight.

Specifics for KSTL:
Next round of showers continuing to develop and slide northward
moving into the metro area by 14z and persist through most of
forecast period. Cigs to lower to mvfr by 14z, then down to ifr by 20z.
In the meantime, winds to persist from the south today. As
surface low lifts through region, cold front associated with it to
slide metro area by 07z Monday. Winds to veer to the west behind
from and become gusty at times. Colder air will filter on back
side of system with rain becoming mixed with snow after 13z
Monday.

Byrd
&&

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

$$
WFO LSX







000
FXUS63 KLSX 231228
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
628 AM CST Sun Nov 23 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 331 AM CST Sun Nov 23 2014

Surface low to begin lifting northeastward towards forecast area
today. Will see showers on the increase this morning and spread
north across the region. Some instability today so there is a chance
of thunderstorms mainly along and south of I-70.  As for
temperatures, will depend on cloud cover and rainfall. But feel that
temps will rise into the mid 50s to low 60s by this afternoon.

Byrd

.LONG TERM:  (Tonight through Saturday)
Issued at 331 AM CST Sun Nov 23 2014

(Tonight-Wednesday)

While specific precip trends are certainly tricky tonight and into
Monday, latest synoptic and hi-res guidance suggests the general
scenario will be that this afternoon`s band of rain and embedded
thunderstorms will rotate east out of the area this evening, as
additional precip begins to form to our west as secondary shortwave
drops south in the wake of today`s system.  This secondary area of
precip should then wind down to spotty areas of light rain/light
snow during the day on Monday.

Yesterday`s guidance as well as 00z model output is now suggesting
more precip lingering in the cold air late tonight and early Monday
than was indicated by earlier runs.  I have not made any major
changes to the timing of the changeover from rain to snow over the
northwest half of the CWA in the 06-12z time frame; this may be a
bit too fast, but didn`t want to discount the intensity of the
CAA. In the far NW counties, it appears that this strong CAA will
cause freezing levels to drop enough to support the rain changing
over to all snow for a few hours late tonight and into early
Monday morning, and based on this have added some minor accumulations
of under an inch in our extreme northwest counties.

Min/max temps for tonight/Monday will be based on non-diurnal, 3
hourly temp trends during this time frame.

No major changes in going forecast trends heading into midweek, with
dry and chlly weather on Tuesday followed by a brief warmup and low
PoPs for the fast-moving, moisture-starved system on Wednesday.

(Thursday-Saturday)

Medium range guidance has come into better agreement with a less
amplified solution for Thanksgiving Day, suggesting a ribbon of
light precip over northern sections of the CWA as shortwave
interacts with baroclinicity that is draped across the region.
Pattern suggests that there should be a strong temperature
gradient from north to south across the region, with highs in the
30s over the cold air in the north while approaching 50 in the
warmer air over southern sections of the CWA.

This agreement jumps the tracks heading into the latter half of the
week, with GEM and ECMWF forecasting broad trofing over the central
CONUS while the GFS maintains a more quasi-zonal look.  Of course,
given the intensity of the baroclinic zone this somewhat subtle
difference will make a huge impact on sensible weather trends, and
especially on temperatures.  This discrepency can be seen in the
surface prog forecasts for Friday morning; ECMWF and GEM have broad
and cold Canadian high over the plains and into the upper
Mississippi Valley with north/northeast winds over our FA, while GFS
as surface low over the northern plains and southerly winds over our
area.  MOS guidance based on these solutions offer a more
quanitative and stark measure of this discrepency...a whopping
20-25 degree difference on Friday`s highs between the colder
ECMWF and warmer GFS. For now have maintained earlier (colder)
trends, based on consensus of GEM and ECMEF.

Truett
&&

.AVIATION:  (For the 12z TAFs through 12z Monday Morning)
Issued at 628 AM CST Sun Nov 23 2014

Next round of showers continuing to develop and slide northward
through forecast area and persist through most of forecast period.
Cigs to lower to mvfr by mid morning, then down to ifr. In the
meantime, winds to persist from the southeast to south today. As
surface low lifts through region, cold front associated with it to
slide through area tonight. Front to move through KCOU by 03z
Monday, KUIN by 04z Monday and metro area tafs by 07z Monday.
Winds to veer to the west behind from and become gusty at times.
Colder air will filter on back side of system with rain becoming
mixed with snow after midnight tonight.

Specifics for KSTL:
Next round of showers continuing to develop and slide northward
moving into the metro area by 14z and persist through most of
forecast period. Cigs to lower to mvfr by 14z, then down to ifr by 20z.
In the meantime, winds to persist from the south today. As
surface low lifts through region, cold front associated with it to
slide metro area by 07z Monday. Winds to veer to the west behind
from and become gusty at times. Colder air will filter on back
side of system with rain becoming mixed with snow after 13z
Monday.

Byrd
&&

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

$$
WFO LSX






000
FXUS63 KLSX 230937
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
337 AM CST Sun Nov 23 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 331 AM CST Sun Nov 23 2014

Surface low to begin lifting northeastward towards forecast area
today. Will see showers on the increase this morning and spread
north across the region. Some instability today so there is a chance
of thunderstorms mainly along and south of I-70.  As for
temperatures, will depend on cloud cover and rainfall. But feel that
temps will rise into the mid 50s to low 60s by this afternoon.

Byrd

.LONG TERM:  (Tonight through Saturday)
Issued at 331 AM CST Sun Nov 23 2014

(Tonight-Wednesday)

While specific precip trends are certainly tricky tonight and into
Monday, latest synoptic and hi-res guidance suggests the general
scenario will be that this afternoon`s band of rain and embedded
thunderstorms will rotate east out of the area this evening, as
additional precip begins to form to our west as secondary shortwave
drops south in the wake of today`s system.  This secondary area of
precip should then wind down to spotty areas of light rain/light
snow during the day on Monday.

Yesterday`s guidance as well as 00z model output is now suggesting
more precip lingering in the cold air late tonight and early Monday
than was indicated by earlier runs.  I have not made any major
changes to the timing of the changeover from rain to snow over the
northwest half of the CWA in the 06-12z time frame; this may be a
bit too fast, but didn`t want to discount the intensity of the
CAA. In the far NW counties, it appears that this strong CAA will
cause freezing levels to drop enough to support the rain changing
over to all snow for a few hours late tonight and into early
Monday morning, and based on this have added some minor accumulations
of under an inch in our extreme northwest counties.

Min/max temps for tonight/Monday will be based on non-diurnal, 3
hourly temp trends during this time frame.

No major changes in going forecast trends heading into midweek, with
dry and chlly weather on Tuesday followed by a brief warmup and low
PoPs for the fast-moving, moisture-starved system on Wednesday.

(Thursday-Saturday)

Medium range guidance has come into better agreement with a less
amplified solution for Thanksgiving Day, suggesting a ribbon of
light precip over northern sections of the CWA as shortwave
interacts with baroclinicity that is draped across the region.
Pattern suggests that there should be a strong temperature
gradient from north to south across the region, with highs in the
30s over the cold air in the north while approaching 50 in the
warmer air over southern sections of the CWA.

This agreement jumps the tracks heading into the latter half of the
week, with GEM and ECMWF forecasting broad trofing over the central
CONUS while the GFS maintains a more quasi-zonal look.  Of course,
given the intensity of the baroclinic zone this somewhat subtle
difference will make a huge impact on sensible weather trends, and
especially on temperatures.  This discrepency can be seen in the
surface prog forecasts for Friday morning; ECMWF and GEM have broad
and cold Canadian high over the plains and into the upper
Mississippi Valley with north/northeast winds over our FA, while GFS
as surface low over the northern plains and southerly winds over our
area.  MOS guidance based on these solutions offer a more
quanitative and stark measure of this discrepency...a whopping
20-25 degree difference on Friday`s highs between the colder
ECMWF and warmer GFS. For now have maintained earlier (colder)
trends, based on consensus of GEM and ECMEF.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Sunday Night)
Issued at 1136 PM CST Sat Nov 22 2014

Specifics for KCOU, KUIN: An approaching low pressure system will
bring widespread rainfall and IFR conditions to the area on
Sunday. Winds will become northwesterly behind a cold front
towards the end of the 24-hr TAF period at KUIN. Just beyond the
end of the TAF period, a brief period of light snow is possible
while precipitation is ending.

Specifics for KSTL, KSUS, KCPS: Despite several hours of
persistent light rainfall at night along with steadily increasing
surface dew points, ceilings have remained predominantly VFR at
the St. Louis metro area TAF sites over the last 6 hours. Most
perplexing. In any event, confidence in cig/vis trends is lower
during the first 0-6 hours of the TAF period compared to later,
when a strong low pressure system will bring widespread rainfall
and IFR conditions to the area. Conditions will deteriorate with
time, especially after 10-12z. Winds will become westerly to
northwesterly and increase behind a cold front towards the end of
the 30-hr TAF period.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 230937
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
337 AM CST Sun Nov 23 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 331 AM CST Sun Nov 23 2014

Surface low to begin lifting northeastward towards forecast area
today. Will see showers on the increase this morning and spread
north across the region. Some instability today so there is a chance
of thunderstorms mainly along and south of I-70.  As for
temperatures, will depend on cloud cover and rainfall. But feel that
temps will rise into the mid 50s to low 60s by this afternoon.

Byrd

.LONG TERM:  (Tonight through Saturday)
Issued at 331 AM CST Sun Nov 23 2014

(Tonight-Wednesday)

While specific precip trends are certainly tricky tonight and into
Monday, latest synoptic and hi-res guidance suggests the general
scenario will be that this afternoon`s band of rain and embedded
thunderstorms will rotate east out of the area this evening, as
additional precip begins to form to our west as secondary shortwave
drops south in the wake of today`s system.  This secondary area of
precip should then wind down to spotty areas of light rain/light
snow during the day on Monday.

Yesterday`s guidance as well as 00z model output is now suggesting
more precip lingering in the cold air late tonight and early Monday
than was indicated by earlier runs.  I have not made any major
changes to the timing of the changeover from rain to snow over the
northwest half of the CWA in the 06-12z time frame; this may be a
bit too fast, but didn`t want to discount the intensity of the
CAA. In the far NW counties, it appears that this strong CAA will
cause freezing levels to drop enough to support the rain changing
over to all snow for a few hours late tonight and into early
Monday morning, and based on this have added some minor accumulations
of under an inch in our extreme northwest counties.

Min/max temps for tonight/Monday will be based on non-diurnal, 3
hourly temp trends during this time frame.

No major changes in going forecast trends heading into midweek, with
dry and chlly weather on Tuesday followed by a brief warmup and low
PoPs for the fast-moving, moisture-starved system on Wednesday.

(Thursday-Saturday)

Medium range guidance has come into better agreement with a less
amplified solution for Thanksgiving Day, suggesting a ribbon of
light precip over northern sections of the CWA as shortwave
interacts with baroclinicity that is draped across the region.
Pattern suggests that there should be a strong temperature
gradient from north to south across the region, with highs in the
30s over the cold air in the north while approaching 50 in the
warmer air over southern sections of the CWA.

This agreement jumps the tracks heading into the latter half of the
week, with GEM and ECMWF forecasting broad trofing over the central
CONUS while the GFS maintains a more quasi-zonal look.  Of course,
given the intensity of the baroclinic zone this somewhat subtle
difference will make a huge impact on sensible weather trends, and
especially on temperatures.  This discrepency can be seen in the
surface prog forecasts for Friday morning; ECMWF and GEM have broad
and cold Canadian high over the plains and into the upper
Mississippi Valley with north/northeast winds over our FA, while GFS
as surface low over the northern plains and southerly winds over our
area.  MOS guidance based on these solutions offer a more
quanitative and stark measure of this discrepency...a whopping
20-25 degree difference on Friday`s highs between the colder
ECMWF and warmer GFS. For now have maintained earlier (colder)
trends, based on consensus of GEM and ECMEF.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Sunday Night)
Issued at 1136 PM CST Sat Nov 22 2014

Specifics for KCOU, KUIN: An approaching low pressure system will
bring widespread rainfall and IFR conditions to the area on
Sunday. Winds will become northwesterly behind a cold front
towards the end of the 24-hr TAF period at KUIN. Just beyond the
end of the TAF period, a brief period of light snow is possible
while precipitation is ending.

Specifics for KSTL, KSUS, KCPS: Despite several hours of
persistent light rainfall at night along with steadily increasing
surface dew points, ceilings have remained predominantly VFR at
the St. Louis metro area TAF sites over the last 6 hours. Most
perplexing. In any event, confidence in cig/vis trends is lower
during the first 0-6 hours of the TAF period compared to later,
when a strong low pressure system will bring widespread rainfall
and IFR conditions to the area. Conditions will deteriorate with
time, especially after 10-12z. Winds will become westerly to
northwesterly and increase behind a cold front towards the end of
the 30-hr TAF period.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 230607
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1207 AM CST Sun Nov 23 2014

.UPDATE:
Issued at 639 PM CST Sat Nov 22 2014

Have made some refinements to the POPS tonight into early Sunday
morning. The main axis of rain/showers this evening will reside
across southeast MO across southwest and south central IL within
the warm moist conveyor belt and ahead of a subtle impulse in the
southwest flow aloft. Further north and northwest across northeast
and central MO the chance of precipitation appears rather low
given the lack of any forcing, and if any occurs it will likely be
isolated or in the form of sprinkles or drizzle. The precipitation
threat will ramp up overnight however in central and northeast MO,
especially after 08-09z with large scale ascent associated with a
shortwave currently over TX moves northeastward into the area and
low level flow backs refocusing the lift westward. Lift and
showers/rain associated with this wave will overspread the entire
area early-mid Sunday morning.

Glass

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014

Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains.  Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area.  This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z.   While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight.  By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough.  With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.

Britt

.LONG TERM:  (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014

Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains.  The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region.  The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday.  There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL.  Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front.  The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains.  As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL.  Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL.  Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area.  An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday.  The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.

GKS

&&

.AVIATION:  (For the 06z TAFs through 06z Sunday Night)
Issued at 1136 PM CST Sat Nov 22 2014

Specifics for KCOU, KUIN: An approaching low pressure system will
bring widespread rainfall and IFR conditions to the area on
Sunday. Winds will become northwesterly behind a cold front
towards the end of the 24-hr TAF period at KUIN. Just beyond the
end of the TAF period, a brief period of light snow is possible
while precipitation is ending.

Specifics for KSTL, KSUS, KCPS: Despite several hours of
persistent light rainfall at night along with steadily increasing
surface dew points, ceilings have remained predominantly VFR at
the St. Louis metro area TAF sites over the last 6 hours. Most
perplexing. In any event, confidence in cig/vis trends is lower
during the first 0-6 hours of the TAF period compared to later,
when a strong low pressure system will bring widespread rainfall
and IFR conditions to the area. Conditions will deteriorate with
time, especially after 10-12z. Winds will become westerly to
northwesterly and increase behind a cold front towards the end of
the 30-hr TAF period.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 230607
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1207 AM CST Sun Nov 23 2014

.UPDATE:
Issued at 639 PM CST Sat Nov 22 2014

Have made some refinements to the POPS tonight into early Sunday
morning. The main axis of rain/showers this evening will reside
across southeast MO across southwest and south central IL within
the warm moist conveyor belt and ahead of a subtle impulse in the
southwest flow aloft. Further north and northwest across northeast
and central MO the chance of precipitation appears rather low
given the lack of any forcing, and if any occurs it will likely be
isolated or in the form of sprinkles or drizzle. The precipitation
threat will ramp up overnight however in central and northeast MO,
especially after 08-09z with large scale ascent associated with a
shortwave currently over TX moves northeastward into the area and
low level flow backs refocusing the lift westward. Lift and
showers/rain associated with this wave will overspread the entire
area early-mid Sunday morning.

Glass

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014

Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains.  Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area.  This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z.   While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight.  By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough.  With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.

Britt

.LONG TERM:  (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014

Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains.  The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region.  The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday.  There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL.  Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front.  The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains.  As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL.  Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL.  Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area.  An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday.  The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.

GKS

&&

.AVIATION:  (For the 06z TAFs through 06z Sunday Night)
Issued at 1136 PM CST Sat Nov 22 2014

Specifics for KCOU, KUIN: An approaching low pressure system will
bring widespread rainfall and IFR conditions to the area on
Sunday. Winds will become northwesterly behind a cold front
towards the end of the 24-hr TAF period at KUIN. Just beyond the
end of the TAF period, a brief period of light snow is possible
while precipitation is ending.

Specifics for KSTL, KSUS, KCPS: Despite several hours of
persistent light rainfall at night along with steadily increasing
surface dew points, ceilings have remained predominantly VFR at
the St. Louis metro area TAF sites over the last 6 hours. Most
perplexing. In any event, confidence in cig/vis trends is lower
during the first 0-6 hours of the TAF period compared to later,
when a strong low pressure system will bring widespread rainfall
and IFR conditions to the area. Conditions will deteriorate with
time, especially after 10-12z. Winds will become westerly to
northwesterly and increase behind a cold front towards the end of
the 30-hr TAF period.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 230046
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
646 PM CST Sat Nov 22 2014

.UPDATE:
Issued at 639 PM CST Sat Nov 22 2014

Have made some refinements to the POPS tonight into early Sunday
morning. The main axis of rain/showers this evening will reside
across southeast MO across southwest and south central IL within
the warm moist conveyor belt and ahead of a subtle impulse in the
southwest flow aloft. Further north and northwest across northeast
and central MO the chance of precipitation appears rather low
given the lack of any forcing, and if any occurs it will likely be
isolated or in the form of sprinkles or drizzle. The precipitation
threat will ramp up overnight however in central and northeast MO,
especially after 08-09z with large scale ascent associated with a
shortwave currently over TX moves northeastward into the area and
low level flow backs refocusing the lift westward. Lift and
showers/rain associated with this wave will overspread the entire
area early-mid Sunday morning.

Glass

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014

Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains.  Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area.  This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z.   While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight.  By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough.  With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.

Britt

.LONG TERM:  (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014

Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains.  The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region.  The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday.  There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL.  Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front.  The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains.  As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL.  Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL.  Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area.  An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday.  The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Sunday Evening)
Issued at 522 PM CST Sat Nov 22 2014

Specifics for KCOU, KUIN: Conditions may initially bounce between
MVFR and VFR early in the TAF period, but any improvement to VFR should
be temporary based on a broader cig/vis analysis and moisture
forecasts. An approaching low pressure system will bring
widespread rain to KCOU and KUIN on Sunday, and conditions are
expected to fall to IFR. Precipitation should end with the passage
of a cold front beyond the end of the 24-hr TAF period.

Specifics for KSTL, KSUS, KCPS: An area of rain showers was moving
northeastwards across the St. Louis metro area terminals at TAF
issuance. Ceilings will probably bounce between VFR and MVFR
before falling solidly into MVFR with the arrival of the rain.
Much more widespread rain is expected on Sunday ahead of a low
pressure system, and conditions will likely fall to IFR during
this time. Rain should end on Sunday night with the arrival of a
cold front.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 230046
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
646 PM CST Sat Nov 22 2014

.UPDATE:
Issued at 639 PM CST Sat Nov 22 2014

Have made some refinements to the POPS tonight into early Sunday
morning. The main axis of rain/showers this evening will reside
across southeast MO across southwest and south central IL within
the warm moist conveyor belt and ahead of a subtle impulse in the
southwest flow aloft. Further north and northwest across northeast
and central MO the chance of precipitation appears rather low
given the lack of any forcing, and if any occurs it will likely be
isolated or in the form of sprinkles or drizzle. The precipitation
threat will ramp up overnight however in central and northeast MO,
especially after 08-09z with large scale ascent associated with a
shortwave currently over TX moves northeastward into the area and
low level flow backs refocusing the lift westward. Lift and
showers/rain associated with this wave will overspread the entire
area early-mid Sunday morning.

Glass

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014

Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains.  Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area.  This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z.   While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight.  By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough.  With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.

Britt

.LONG TERM:  (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014

Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains.  The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region.  The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday.  There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL.  Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front.  The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains.  As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL.  Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL.  Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area.  An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday.  The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Sunday Evening)
Issued at 522 PM CST Sat Nov 22 2014

Specifics for KCOU, KUIN: Conditions may initially bounce between
MVFR and VFR early in the TAF period, but any improvement to VFR should
be temporary based on a broader cig/vis analysis and moisture
forecasts. An approaching low pressure system will bring
widespread rain to KCOU and KUIN on Sunday, and conditions are
expected to fall to IFR. Precipitation should end with the passage
of a cold front beyond the end of the 24-hr TAF period.

Specifics for KSTL, KSUS, KCPS: An area of rain showers was moving
northeastwards across the St. Louis metro area terminals at TAF
issuance. Ceilings will probably bounce between VFR and MVFR
before falling solidly into MVFR with the arrival of the rain.
Much more widespread rain is expected on Sunday ahead of a low
pressure system, and conditions will likely fall to IFR during
this time. Rain should end on Sunday night with the arrival of a
cold front.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 222338
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
538 PM CST Sat Nov 22 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014

Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains.  Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area.  This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z.   While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight.  By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough.  With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.

Britt

.LONG TERM:  (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014

Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains.  The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region.  The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday.  There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL.  Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front.  The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains.  As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL.  Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL.  Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area.  An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday.  The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Sunday Evening)
Issued at 522 PM CST Sat Nov 22 2014

Specifics for KCOU, KUIN: Conditions may initially bounce between
MVFR and VFR early in the TAF period, but any improvement to VFR should
be temporary based on a broader cig/vis analysis and moisture
forecasts. An approaching low pressure system will bring
widespread rain to KCOU and KUIN on Sunday, and conditions are
expected to fall to IFR. Precipitation should end with the passage
of a cold front beyond the end of the 24-hr TAF period.

Specifics for KSTL, KSUS, KCPS: An area of rain showers was moving
northeastwards across the St. Louis metro area terminals at TAF
issuance. Ceilings will probably bounce between VFR and MVFR
before falling solidly into MVFR with the arrival of the rain.
Much more widespread rain is expected on Sunday ahead of a low
pressure system, and conditions will likely fall to IFR during
this time. Rain should end on Sunday night with the arrival of a
cold front.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 222147
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
347 PM CST Sat Nov 22 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014

Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains.  Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area.  This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z.   While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight.  By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough.  With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.

Britt

.LONG TERM:  (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014

Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains.  The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region.  The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday.  There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL.  Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front.  The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains.  As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL.  Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL.  Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area.  An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday.  The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.

GKS

&&

.AVIATION:  (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1235 PM CST Sat Nov 22 2014

Have added tempo groups for showers later this afternoon and early
this evening at the STL metro TAF sites as an area of showers over
southwest Missouri moves northeast. MVFR ceilings are expected
through 10-15Z when a steadier rain is expected to develop. Once
this steady rain moves into the area, IFR conditions are expected
on Sunday at all TAF sites.

Specifics for KSTL: Expect ceilings between 2000-3000ft through
22Z. Then an area of showers will move into the terminal from the
southwest which may cause ceilings to fall below 2000ft into the
early evening hours. Then expect most of the night to be dry with
just scattered showers in the area before lower ceilings and more
widespread showers move into the area after 09Z, with steady rain
and IFR conditions moving into the area by mid morning Sunday.

Britt

&&

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

$$

WFO LSX







000
FXUS63 KLSX 222147
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
347 PM CST Sat Nov 22 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 347 PM CST Sat Nov 22 2014

Scattered showers are already moving across the southern half the
CWA this afternoon in an area of modest 925-850mb moisture
convergence ahead of the trough currently over the southern High
Plains.  Expect rain to become more widespread late this afternoon
into the early evening hours over the southern two thirds of the CWA
as the showers currently over southwest Missouri continue to move
northeast into the area.  This is being forced by an area of
stronger low level moisture convergence that the HRRR shows moving
across the area between 22-03Z.   While there will still continue to
be scattered showers elsewhere behind this area through late
evening, it still appears that better chances for more widespread
rain will move in from the west after midnight.  By that time, large
scale ascent and moisture convergence will be increasing ahead of the
aforementioned southern Plains trough that will be ejecting
northeastward ahead of longwave trough.  With clouds and warm air
advection tonight, stayed with lows that were close to going
temperatures and MOS guidance.

Britt

.LONG TERM:  (Sunday through Next Saturday)
Issued at 347 PM CST Sat Nov 22 2014

Rain and a few thunderstorms are expected on Sunday as a southern
stream, negatively tilted shortwave moves from eastern TX
northeastward into the TN and OH Valley regions, while a northern
stream upper level trough/low moves slowly east southeastward
through the northern Plains.  The models were depicting upper level
divergence over our area between a strong upper level jet streak
across the southern Plains and a weaker upper level jet streak over
the Great Lakes region.  The models have some discrepencies as to
the exact track of the deepening surface low, but at this time it
appears that it will move northeastward through or just north of the
STL area around 00z Monday.  There will be ample instability for at
least isolated thunderstorms on Sunday into Sunday evening,
especially across southeast MO and southwest IL.  Strong low level
cold air advection can be expected Sunday night after the passage of
the low and trailing cold front.  The threat for precipitation will
continue Sunday night as shortwaves rotate through our area south of
the main upper level low/trough over the northern Plains.  As the
colder air filters southeastward into the region the rain may change
over to light snow before ending late Sunday night/early Monday
morning across portions of northeast and central MO as well as west
central IL.  Most of the precipitation will shift east of our
forecast area by Monday, although there may be some lingering light
snow or flurries mainly across west central IL.  Much colder
temperatures can be expected for Monday, with nearly steady
temperatures, mainly in the middle 30s to lower 40s as the NAM and
ECMWF models drop the -8 degree C 850 mb isotherm southward to STL.
The GFS model is even colder and quicker bringing the colder air
southeastward into our forecast area.  An unseasonably cold period
is expected through Tuesday night as a large amplitude positively
tilted upper level trough moves eastward through the central US.
The GFS and ECMWF models are still hinting at the possibility of a
northwest flow shortwave and associated weak surface low to bring a
quick shot of rain/snow to our area late Tuesday night and
Wednesday.  The models, particularly the GFS are not as cold for
Thanksgiving Day with the coldest air remaining just north of our
forecast area, although a strong surface ridge is still forecast to
build southeastward into the region from the northern Plains on
Thanksgiving.

GKS

&&

.AVIATION:  (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1235 PM CST Sat Nov 22 2014

Have added tempo groups for showers later this afternoon and early
this evening at the STL metro TAF sites as an area of showers over
southwest Missouri moves northeast. MVFR ceilings are expected
through 10-15Z when a steadier rain is expected to develop. Once
this steady rain moves into the area, IFR conditions are expected
on Sunday at all TAF sites.

Specifics for KSTL: Expect ceilings between 2000-3000ft through
22Z. Then an area of showers will move into the terminal from the
southwest which may cause ceilings to fall below 2000ft into the
early evening hours. Then expect most of the night to be dry with
just scattered showers in the area before lower ceilings and more
widespread showers move into the area after 09Z, with steady rain
and IFR conditions moving into the area by mid morning Sunday.

Britt

&&

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

$$

WFO LSX








000
FXUS63 KLSX 221835
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
1235 PM CST Sat Nov 22 2014

.UPDATE:
Issued at 1234 PM CST Sat Nov 22 2014

Have updated forecast to include area of showers and isolated
thunderstorms that have moved into southeast Missouri as well as
far southwest Illinois. HRRR is also showing that area of showers
over far southwest Missouri will move into east central Missouri
and adjacent parts of Illinois late this afternoon and early this
evening. Increased chances to likely in both these locations.
Temperatures have already climbed into upper 50s and lower 60s in
most areas, so have increased high temperatures accordingly.

Britt

&&

.SHORT TERM:  (Through Late This Afternoon)
Issued at 322 AM CST Sat Nov 22 2014

Main area of precipitation has moved out of region, though there is
some widely scattered activity as well as drizzle over northern
portions of forecast area early this morning. Next shortwave to
slide northeast through forecast area today, but precipitation will
continue to be scattered in nature. Some elevated instability over
southern portions of region this afternoon, so still could see
isolated thunder in this area. Otherwise, just scattered showers
under cloudy skies. Temperatures to be near normal or just above
normal in the mid 50s to low 60s.

Byrd

.LONG TERM:  (Tonight through Friday)
Issued at 322 AM CST Sat Nov 22 2014

(Tonight-Monday)

Overall forecast trends still looking pretty good, and main
changes will be an attempt to fine-tune these trends.

This afternoon`s expected scattered coverage will likely linger into
this evening, but precipitation threat should ramp up considerably
late tonight and into Sunday as dynamics from strong upper system
working northeast from the southern plains and increasing moisture
begin to come into phase over the region.  Like the trends suggested
by 00z model QPFs that by Sunday morning main focus of rain will
stretch from southwest into northeast Missouri, with this band of
rain then expanding and working east during the day.  With the above
trends in mind, I`ve also attempted to minimize PoPs in our far e
counties until Sunday afternoon, as moisture and lift will be
somewhat limited in this part of the FA until then.  Although
instability is progged by all models to remain quite limited due to
saturated AMS I`ve continued a mention of thunder over the Ozarks
tonight and into the southeast half of the CWA on Sunday.

All of the 00z output is continuing to suggest that as dynamics with
the first system pushes into the Ohio Valley on Sunday evening, a
secondary area of precip should develop in its wake as another
shortwave drops into the base of the longwave trof.  Ptypes could
become an issue by late Sunday night on the back edge of this round
of precip as southward surge of cold air will be causing the
freezing levels to drop; however at this time not expecting any
major issues as forecast soundings suggest ams will get cold enough
to support snow just as the precip begins to wind down. Threat of
measurable precip with this secondary shortwave should come to an
end on Monday morning, although we do anticipate that some flurries
will linger into the afternoon over northern sections of the CWA
where cold advection and cyclonic low level flow will be the
strongest.

Today`s moderation in temps will persist into Sunday, but return
of cold air will mean more below average temperatures for the
start of the new week.

(Tuesday-Friday)

Surface ridge is expected to work across the region on Tuesday,
giving the FA chilly but dry late November weather. It still
appears that another fast moving shortwave digging into
progressive longwave trof will produce a quick shot of lift across
the region by Wednesday, but strongest dynamics will be north of
our area and moisture will be quite limited, so going slight
chance/low chance PoPs still look good at midweek.

Medium range solutions still leaving questions regarding sensible
weather trends heading into the Thanksgiving holiday.  GFS is now
supported by the GEM in suggesting much less deepening of the
longwave trof over the eastern CONUS.  This keeps baroclinicity
further north and allows the next fast moving shortwave to interact
with this thermal gradient, which would suggest a threat of some
light precip on Thanksgiving over northern sections of the CWA.
ECMWF is still deeper with the trof to our east, but its interesting
that its not as deep as was suggested in yesterday`s guidance, and
in fact has trended a bit more towards a flatter mid level flow.
For now will maintain dry forecast, but this trend will be
interesting to watch over the next few forecast cycles.

With the reintensification of the trof over the eastern CONUS temps
will remain well below normal during the latter half of the
upcoming work week, although exact extent of the cold will
obviously depend on the intensity of the trof. Highs primarily in
the 30s heading into Thursday and Friday look like a good starting
point for now.

Truett

&&

.AVIATION:  (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1235 PM CST Sat Nov 22 2014

Have added tempo groups for showers later this afternoon and early
this evening at the STL metro TAF sites as an area of showers over
southwest Missouri moves northeast. MVFR ceilings are expected
through 10-15Z when a steadier rain is expected to develop. Once
this steady rain moves into the area, IFR conditions are expected
on Sunday at all TAF sites.

Specifics for KSTL: Expect ceilings between 2000-3000ft through
22Z. Then an area of showers will move into the terminal from the
southwest which may cause ceilings to fall below 2000ft into the
early evening hours. Then expect most of the night to be dry with
just scattered showers in the area before lower ceilings and more
widespread showers move into the area after 09Z, with steady rain
and IFR conditions moving into the area by mid morning Sunday.

Britt

&&

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

$$

WFO LSX







000
FXUS63 KLSX 221208
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
608 AM CST Sat Nov 22 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 322 AM CST Sat Nov 22 2014

Main area of precipitation has moved out of region, though there is
some widely scattered activity as well as drizzle over northern
portions of forecast area early this morning. Next shortwave to
slide northeast through forecast area today, but precipitation will
continue to be scattered in nature. Some elevated instability over
southern portions of region this afternoon, so still could see
isolated thunder in this area. Otherwise, just scattered showers
under cloudy skies. Temperatures to be near normal or just above
normal in the mid 50s to low 60s.

Byrd

.LONG TERM:  (Tonight through Friday)
Issued at 322 AM CST Sat Nov 22 2014

(Tonight-Monday)

Overall foreast trends still looking pretty good, and main changes
will be an attempt to fine-tune these trends.

This afternoon`s expected scattered coverage will likely linger into
this evening, but precipitation threat should ramp up considerably
late tonight and into Sunday as dynamics from strong upper system
working northeast from the southern plains and increasing moisture
begin to come into phase over the region.  Like the trends suggested
by 00z model QPFs that by Sunday morning main focus of rain will
stretch from southwest into northeast Missouri, with this band of
rain then expanding and working east during the day.  With the above
trends in mind, I`ve also attempted to minimize PoPs in our far e
counties until Sunday afternoon, as moisture and lift will be
somewhat limited in this part of the FA until then.  Although
instability is progged by all models to remain quite limited due to
saturated AMS I`ve continued a mention of thunder over the Ozarks
tonight and into the southeast half of the CWA on Sunday.

All of the 00z output is continuing to suggest that as dynamics with
the first system pushes into the Ohio Valley on Sunday evening, a
secondary area of precip should develop in its wake as another
shortwave drops into the base of the longwave trof.  Ptypes could
become an issue by late Sunday night on the back edge of this round
of precip as southward surge of cold air will be causing the
freezing levels to drop; however at this time not expecting any
major issues as forecast soundings suggest ams will get cold enough
to support snow just as the precip begins to wind down. Threat of
measurable precip with this secondary shortwave should come to an
end on Monday morning, although we do anticipate that some flurries
will linger into the afternoon over northern sections of the CWA
where cold advection and cyclonic low level flow will be the
strongest.

Today`s moderation in temps will persist into Sunday, but return
of cold air will mean more below average temperatures for the
start of the new week.

(Tuesday-Friday)

Surface ridge is expected to work across the region on Tuesday,
giving the FA chilly but dry late November weather. It still
appears that another fast moving shortwave digging into
progressive longwave trof will produce a quick shot of lift across
the region by Wednesday, but strongest dynamics will be north of
our area and moisture will be quite limited, so going slight
chance/low chance PoPs still look good at midweek.

Medium range solutions still leaving questions regarding sensible
weather trends heading into the Thanksgiving holiday.  GFS is now
supported by the GEM in suggesting much less deepening of the
longwave trof over the eastern CONUS.  This keeps baroclinicity
further north and allows the next fast moving shortwave to interact
with this thermal gradient, which would suggest a threat of some
light precip on Thanksgiving over northern sections of the CWA.
ECMWF is still deeper with the trof to our east, but its interesting
that its not as deep as was suggested in yesterday`s guidance, and
in fact has trended a bit more towards a flatter mid level flow.
For now will maintain dry forecast, but this trend will be
interesting to watch over the next few forecast cycles.

With the reintensification of the trof over the eastern CONUS temps
will remain well below normal during the latter half of the
upcoming work week, although exact extent of the cold will
obviously depend on the intensity of the trof. Highs primarily in
the 30s heading into Thursday and Friday look like a good starting
point for now.

Truett
&&

.AVIATION:  (For the 12z TAFs through 12z Sunday Morning)
Issued at 608 AM CST Sat Nov 22 2014

Initial wave of rain has moved out of region but still have widely
scattered showers. However, coverage is spotty so kept tafs dry
through today and early this evening. Otherwise, clouds to remain
over region. Cigs have lifted to VFR for sites along I-70 corridor
while KUIN remains MVFR. Better chances of rain to move in after
06z Sunday with cigs lowering back down to mvfr. As for winds, LLWS to
persist through 14z Saturday before mixing out. Winds then will
persist from the south through the forecast period.

Specifics for KSTL:
Initial wave of rain has moved out of region but still have widely
scattered showers. However, coverage is spotty so kept taf dry
through today and early this evening. Otherwise, clouds to remain
over region. Cigs have lifted to VFR for metro area. Better chances
of rain to move in after 09z Sunday with cigs lowering back down
to mvfr. As for winds, LLWS to persist through 14z Saturday before
mixing out. Winds then will persist from the south through the
forecast period.

Byrd
&&

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

$$
WFO LSX







000
FXUS63 KLSX 221208
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
608 AM CST Sat Nov 22 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 322 AM CST Sat Nov 22 2014

Main area of precipitation has moved out of region, though there is
some widely scattered activity as well as drizzle over northern
portions of forecast area early this morning. Next shortwave to
slide northeast through forecast area today, but precipitation will
continue to be scattered in nature. Some elevated instability over
southern portions of region this afternoon, so still could see
isolated thunder in this area. Otherwise, just scattered showers
under cloudy skies. Temperatures to be near normal or just above
normal in the mid 50s to low 60s.

Byrd

.LONG TERM:  (Tonight through Friday)
Issued at 322 AM CST Sat Nov 22 2014

(Tonight-Monday)

Overall foreast trends still looking pretty good, and main changes
will be an attempt to fine-tune these trends.

This afternoon`s expected scattered coverage will likely linger into
this evening, but precipitation threat should ramp up considerably
late tonight and into Sunday as dynamics from strong upper system
working northeast from the southern plains and increasing moisture
begin to come into phase over the region.  Like the trends suggested
by 00z model QPFs that by Sunday morning main focus of rain will
stretch from southwest into northeast Missouri, with this band of
rain then expanding and working east during the day.  With the above
trends in mind, I`ve also attempted to minimize PoPs in our far e
counties until Sunday afternoon, as moisture and lift will be
somewhat limited in this part of the FA until then.  Although
instability is progged by all models to remain quite limited due to
saturated AMS I`ve continued a mention of thunder over the Ozarks
tonight and into the southeast half of the CWA on Sunday.

All of the 00z output is continuing to suggest that as dynamics with
the first system pushes into the Ohio Valley on Sunday evening, a
secondary area of precip should develop in its wake as another
shortwave drops into the base of the longwave trof.  Ptypes could
become an issue by late Sunday night on the back edge of this round
of precip as southward surge of cold air will be causing the
freezing levels to drop; however at this time not expecting any
major issues as forecast soundings suggest ams will get cold enough
to support snow just as the precip begins to wind down. Threat of
measurable precip with this secondary shortwave should come to an
end on Monday morning, although we do anticipate that some flurries
will linger into the afternoon over northern sections of the CWA
where cold advection and cyclonic low level flow will be the
strongest.

Today`s moderation in temps will persist into Sunday, but return
of cold air will mean more below average temperatures for the
start of the new week.

(Tuesday-Friday)

Surface ridge is expected to work across the region on Tuesday,
giving the FA chilly but dry late November weather. It still
appears that another fast moving shortwave digging into
progressive longwave trof will produce a quick shot of lift across
the region by Wednesday, but strongest dynamics will be north of
our area and moisture will be quite limited, so going slight
chance/low chance PoPs still look good at midweek.

Medium range solutions still leaving questions regarding sensible
weather trends heading into the Thanksgiving holiday.  GFS is now
supported by the GEM in suggesting much less deepening of the
longwave trof over the eastern CONUS.  This keeps baroclinicity
further north and allows the next fast moving shortwave to interact
with this thermal gradient, which would suggest a threat of some
light precip on Thanksgiving over northern sections of the CWA.
ECMWF is still deeper with the trof to our east, but its interesting
that its not as deep as was suggested in yesterday`s guidance, and
in fact has trended a bit more towards a flatter mid level flow.
For now will maintain dry forecast, but this trend will be
interesting to watch over the next few forecast cycles.

With the reintensification of the trof over the eastern CONUS temps
will remain well below normal during the latter half of the
upcoming work week, although exact extent of the cold will
obviously depend on the intensity of the trof. Highs primarily in
the 30s heading into Thursday and Friday look like a good starting
point for now.

Truett
&&

.AVIATION:  (For the 12z TAFs through 12z Sunday Morning)
Issued at 608 AM CST Sat Nov 22 2014

Initial wave of rain has moved out of region but still have widely
scattered showers. However, coverage is spotty so kept tafs dry
through today and early this evening. Otherwise, clouds to remain
over region. Cigs have lifted to VFR for sites along I-70 corridor
while KUIN remains MVFR. Better chances of rain to move in after
06z Sunday with cigs lowering back down to mvfr. As for winds, LLWS to
persist through 14z Saturday before mixing out. Winds then will
persist from the south through the forecast period.

Specifics for KSTL:
Initial wave of rain has moved out of region but still have widely
scattered showers. However, coverage is spotty so kept taf dry
through today and early this evening. Otherwise, clouds to remain
over region. Cigs have lifted to VFR for metro area. Better chances
of rain to move in after 09z Sunday with cigs lowering back down
to mvfr. As for winds, LLWS to persist through 14z Saturday before
mixing out. Winds then will persist from the south through the
forecast period.

Byrd
&&

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

$$
WFO LSX






000
FXUS63 KLSX 220925
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
325 AM CST Sat Nov 22 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 322 AM CST Sat Nov 22 2014

Main area of precipitation has moved out of region, though there is
some widely scattered activity as well as drizzle over northern
portions of forecast area early this morning. Next shortwave to
slide northeast through forecast area today, but precipitation will
continue to be scattered in nature. Some elevated instability over
southern portions of region this afternoon, so still could see
isolated thunder in this area. Otherwise, just scattered showers
under cloudy skies. Temperatures to be near normal or just above
normal in the mid 50s to low 60s.

Byrd

.LONG TERM:  (Tonight through Friday)
Issued at 322 AM CST Sat Nov 22 2014

(Tonight-Monday)

Overall foreast trends still looking pretty good, and main changes
will be an attempt to fine-tune these trends.

This afternoon`s expected scattered coverage will likely linger into
this evening, but precipitation threat should ramp up considerably
late tonight and into Sunday as dynamics from strong upper system
working northeast from the southern plains and increasing moisture
begin to come into phase over the region.  Like the trends suggested
by 00z model QPFs that by Sunday morning main focus of rain will
stretch from southwest into northeast Missouri, with this band of
rain then expanding and working east during the day.  With the above
trends in mind, I`ve also attempted to minimize PoPs in our far e
counties until Sunday afternoon, as moisture and lift will be
somewhat limited in this part of the FA until then.  Although
instability is progged by all models to remain quite limited due to
saturated AMS I`ve continued a mention of thunder over the Ozarks
tonight and into the southeast half of the CWA on Sunday.

All of the 00z output is continuing to suggest that as dynamics with
the first system pushes into the Ohio Valley on Sunday evening, a
secondary area of precip should develop in its wake as another
shortwave drops into the base of the longwave trof.  Ptypes could
become an issue by late Sunday night on the back edge of this round
of precip as southward surge of cold air will be causing the
freezing levels to drop; however at this time not expecting any
major issues as forecast soundings suggest ams will get cold enough
to support snow just as the precip begins to wind down. Threat of
measurable precip with this secondary shortwave should come to an
end on Monday morning, although we do anticipate that some flurries
will linger into the afternoon over northern sections of the CWA
where cold advection and cyclonic low level flow will be the
strongest.

Today`s moderation in temps will persist into Sunday, but return
of cold air will mean more below average temperatures for the
start of the new week.

(Tuesday-Friday)

Surface ridge is expected to work across the region on Tuesday,
giving the FA chilly but dry late November weather. It still
appears that another fast moving shortwave digging into
progressive longwave trof will produce a quick shot of lift across
the region by Wednesday, but strongest dynamics will be north of
our area and moisture will be quite limited, so going slight
chance/low chance PoPs still look good at midweek.

Medium range solutions still leaving questions regarding sensible
weather trends heading into the Thanksgiving holiday.  GFS is now
supported by the GEM in suggesting much less deepening of the
longwave trof over the eastern CONUS.  This keeps baroclinicity
further north and allows the next fast moving shortwave to interact
with this thermal gradient, which would suggest a threat of some
light precip on Thanksgiving over northern sections of the CWA.
ECMWF is still deeper with the trof to our east, but its interesting
that its not as deep as was suggested in yesterday`s guidance, and
in fact has trended a bit more towards a flatter mid level flow.
For now will maintain dry forecast, but this trend will be
interesting to watch over the next few forecast cycles.

With the reintensification of the trof over the eastern CONUS temps
will remain well below normal during the latter half of the
upcoming work week, although exact extent of the cold will
obviously depend on the intensity of the trof. Highs primarily in
the 30s heading into Thursday and Friday look like a good starting
point for now.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Saturday Night)
Issued at 1134 PM CST Fri Nov 21 2014

MVFR conditions are expected to prevail overnight and for most of
tomorrow. Some improvement is possible at KCOU between 22/21z and
23/06z before conditions deteriorate again. Light drizzle is
possible overnight. Widespread rain is likely just beyond the end
of the 24-hr TAF period.

Specifics for KSTL: Although conditions may occasionally lift to
VFR for brief periods overnight, MVFR cigs are expected to prevail
until mid to late morning. Light drizzle is also possible.
Widespread rain is likely towards the end of the 30-hr TAF period
and beyond.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 220925
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
325 AM CST Sat Nov 22 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 322 AM CST Sat Nov 22 2014

Main area of precipitation has moved out of region, though there is
some widely scattered activity as well as drizzle over northern
portions of forecast area early this morning. Next shortwave to
slide northeast through forecast area today, but precipitation will
continue to be scattered in nature. Some elevated instability over
southern portions of region this afternoon, so still could see
isolated thunder in this area. Otherwise, just scattered showers
under cloudy skies. Temperatures to be near normal or just above
normal in the mid 50s to low 60s.

Byrd

.LONG TERM:  (Tonight through Friday)
Issued at 322 AM CST Sat Nov 22 2014

(Tonight-Monday)

Overall foreast trends still looking pretty good, and main changes
will be an attempt to fine-tune these trends.

This afternoon`s expected scattered coverage will likely linger into
this evening, but precipitation threat should ramp up considerably
late tonight and into Sunday as dynamics from strong upper system
working northeast from the southern plains and increasing moisture
begin to come into phase over the region.  Like the trends suggested
by 00z model QPFs that by Sunday morning main focus of rain will
stretch from southwest into northeast Missouri, with this band of
rain then expanding and working east during the day.  With the above
trends in mind, I`ve also attempted to minimize PoPs in our far e
counties until Sunday afternoon, as moisture and lift will be
somewhat limited in this part of the FA until then.  Although
instability is progged by all models to remain quite limited due to
saturated AMS I`ve continued a mention of thunder over the Ozarks
tonight and into the southeast half of the CWA on Sunday.

All of the 00z output is continuing to suggest that as dynamics with
the first system pushes into the Ohio Valley on Sunday evening, a
secondary area of precip should develop in its wake as another
shortwave drops into the base of the longwave trof.  Ptypes could
become an issue by late Sunday night on the back edge of this round
of precip as southward surge of cold air will be causing the
freezing levels to drop; however at this time not expecting any
major issues as forecast soundings suggest ams will get cold enough
to support snow just as the precip begins to wind down. Threat of
measurable precip with this secondary shortwave should come to an
end on Monday morning, although we do anticipate that some flurries
will linger into the afternoon over northern sections of the CWA
where cold advection and cyclonic low level flow will be the
strongest.

Today`s moderation in temps will persist into Sunday, but return
of cold air will mean more below average temperatures for the
start of the new week.

(Tuesday-Friday)

Surface ridge is expected to work across the region on Tuesday,
giving the FA chilly but dry late November weather. It still
appears that another fast moving shortwave digging into
progressive longwave trof will produce a quick shot of lift across
the region by Wednesday, but strongest dynamics will be north of
our area and moisture will be quite limited, so going slight
chance/low chance PoPs still look good at midweek.

Medium range solutions still leaving questions regarding sensible
weather trends heading into the Thanksgiving holiday.  GFS is now
supported by the GEM in suggesting much less deepening of the
longwave trof over the eastern CONUS.  This keeps baroclinicity
further north and allows the next fast moving shortwave to interact
with this thermal gradient, which would suggest a threat of some
light precip on Thanksgiving over northern sections of the CWA.
ECMWF is still deeper with the trof to our east, but its interesting
that its not as deep as was suggested in yesterday`s guidance, and
in fact has trended a bit more towards a flatter mid level flow.
For now will maintain dry forecast, but this trend will be
interesting to watch over the next few forecast cycles.

With the reintensification of the trof over the eastern CONUS temps
will remain well below normal during the latter half of the
upcoming work week, although exact extent of the cold will
obviously depend on the intensity of the trof. Highs primarily in
the 30s heading into Thursday and Friday look like a good starting
point for now.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Saturday Night)
Issued at 1134 PM CST Fri Nov 21 2014

MVFR conditions are expected to prevail overnight and for most of
tomorrow. Some improvement is possible at KCOU between 22/21z and
23/06z before conditions deteriorate again. Light drizzle is
possible overnight. Widespread rain is likely just beyond the end
of the 24-hr TAF period.

Specifics for KSTL: Although conditions may occasionally lift to
VFR for brief periods overnight, MVFR cigs are expected to prevail
until mid to late morning. Light drizzle is also possible.
Widespread rain is likely towards the end of the 30-hr TAF period
and beyond.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 220610
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1210 AM CST Sat Nov 22 2014

.UPDATE:
Issued at 1008 PM CST Fri Nov 21 2014

Weak lift and mid level moisture associated with a low-amplitude shortwave
currently located in western MO combined with lift via a southwesterly
LLJ has generated some showers this evening. These showers were
currenly located to the west of the MS river across southwest and
south central IL, moving to the northeast at 30-35 kts. The showers
should exit the CWA by midnight as the shortwave continues to
migrate eastward in the west-southwest flow aloft, also taking the
mid level moisture with it. In its wake during the overnight
hours, the atmosphere will be bottom heavy with moisture confined
to the low levels. This moisture stratification along with continued
weak ascent via low level WAA would support patchy light rain or
drizzle. Accordingly I have lowered pops a bit and refined the
precipitation mode.

Glass

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 06z TAFs through 06z Saturday Night)
Issued at 1134 PM CST Fri Nov 21 2014

MVFR conditions are expected to prevail overnight and for most of
tomorrow. Some improvement is possible at KCOU between 22/21z and
23/06z before conditions deteriorate again. Light drizzle is
possible overnight. Widespread rain is likely just beyond the end
of the 24-hr TAF period.

Specifics for KSTL: Although conditions may occasionally lift to
VFR for brief periods overnight, MVFR cigs are expected to prevail
until mid to late morning. Light drizzle is also possible.
Widespread rain is likely towards the end of the 30-hr TAF period
and beyond.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 220610
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1210 AM CST Sat Nov 22 2014

.UPDATE:
Issued at 1008 PM CST Fri Nov 21 2014

Weak lift and mid level moisture associated with a low-amplitude shortwave
currently located in western MO combined with lift via a southwesterly
LLJ has generated some showers this evening. These showers were
currenly located to the west of the MS river across southwest and
south central IL, moving to the northeast at 30-35 kts. The showers
should exit the CWA by midnight as the shortwave continues to
migrate eastward in the west-southwest flow aloft, also taking the
mid level moisture with it. In its wake during the overnight
hours, the atmosphere will be bottom heavy with moisture confined
to the low levels. This moisture stratification along with continued
weak ascent via low level WAA would support patchy light rain or
drizzle. Accordingly I have lowered pops a bit and refined the
precipitation mode.

Glass

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 06z TAFs through 06z Saturday Night)
Issued at 1134 PM CST Fri Nov 21 2014

MVFR conditions are expected to prevail overnight and for most of
tomorrow. Some improvement is possible at KCOU between 22/21z and
23/06z before conditions deteriorate again. Light drizzle is
possible overnight. Widespread rain is likely just beyond the end
of the 24-hr TAF period.

Specifics for KSTL: Although conditions may occasionally lift to
VFR for brief periods overnight, MVFR cigs are expected to prevail
until mid to late morning. Light drizzle is also possible.
Widespread rain is likely towards the end of the 30-hr TAF period
and beyond.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 220413
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
1013 PM CST Fri Nov 21 2014

.UPDATE:
Issued at 1008 PM CST Fri Nov 21 2014

Weak lift and mid level moisture associated with a low-amplitude shortwave
currently located in western MO combined with lift via a southwesterly
LLJ has generated some showers this evening. These showers were
currenly located to the west of the MS river across southwest and
south central IL, moving to the northeast at 30-35 kts. The showers
should exit the CWA by midnight as the shortwave continues to
migrate eastward in the west-southwest flow aloft, also taking the
mid level moisture with it. In its wake during the overnight
hours, the atmosphere will be bottom heavy with moisture confined
to the low levels. This moisture stratification along with continued
weak ascent via low level WAA would support patchy light rain or
drizzle. Accordingly I have lowered pops a bit and refined the
precipitation mode.

Glass

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Saturday Evening)
Issued at 522 PM CST Fri Nov 21 2014

MVFR cigs are expected to prevail overnight, however there may be
occasional brief periods of low-end VFR ceilings. Widely scattered
rain showers are possible through the period, especially at KCOU and
KUIN. A 50kt southwesterly LLJ will likely produce LLWS conditions
at all terminals between 05-14z.

Specifics for KSTL: MVFR cigs are expected to prevail overnight,
however there may be occasional brief periods of low-end VFR
ceilings. Widely scattered rain showers are possible through the
period. The highest rain chances at KSTL are expected beyond the
end of the 30-hr TAF period. A 50kt southwesterly low level jet
will likely produce LLWS conditions between 05-14z.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 220413
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
1013 PM CST Fri Nov 21 2014

.UPDATE:
Issued at 1008 PM CST Fri Nov 21 2014

Weak lift and mid level moisture associated with a low-amplitude shortwave
currently located in western MO combined with lift via a southwesterly
LLJ has generated some showers this evening. These showers were
currenly located to the west of the MS river across southwest and
south central IL, moving to the northeast at 30-35 kts. The showers
should exit the CWA by midnight as the shortwave continues to
migrate eastward in the west-southwest flow aloft, also taking the
mid level moisture with it. In its wake during the overnight
hours, the atmosphere will be bottom heavy with moisture confined
to the low levels. This moisture stratification along with continued
weak ascent via low level WAA would support patchy light rain or
drizzle. Accordingly I have lowered pops a bit and refined the
precipitation mode.

Glass

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Saturday Evening)
Issued at 522 PM CST Fri Nov 21 2014

MVFR cigs are expected to prevail overnight, however there may be
occasional brief periods of low-end VFR ceilings. Widely scattered
rain showers are possible through the period, especially at KCOU and
KUIN. A 50kt southwesterly LLJ will likely produce LLWS conditions
at all terminals between 05-14z.

Specifics for KSTL: MVFR cigs are expected to prevail overnight,
however there may be occasional brief periods of low-end VFR
ceilings. Widely scattered rain showers are possible through the
period. The highest rain chances at KSTL are expected beyond the
end of the 30-hr TAF period. A 50kt southwesterly low level jet
will likely produce LLWS conditions between 05-14z.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 212350
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
550 PM CST Fri Nov 21 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Saturday Evening)
Issued at 522 PM CST Fri Nov 21 2014

MVFR cigs are expected to prevail overnight, however there may be
occasional brief periods of low-end VFR ceilings. Widely scattered
rain showers are possible through the period, especially at KCOU and
KUIN. A 50kt southwesterly LLJ will likely produce LLWS conditions
at all terminals between 05-14z.

Specifics for KSTL: MVFR cigs are expected to prevail overnight,
however there may be occasional brief periods of low-end VFR
ceilings. Widely scattered rain showers are possible through the
period. The highest rain chances at KSTL are expected beyond the
end of the 30-hr TAF period. A 50kt southwesterly low level jet
will likely produce LLWS conditions between 05-14z.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 212350
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
550 PM CST Fri Nov 21 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 00z TAFs through 00z Saturday Evening)
Issued at 522 PM CST Fri Nov 21 2014

MVFR cigs are expected to prevail overnight, however there may be
occasional brief periods of low-end VFR ceilings. Widely scattered
rain showers are possible through the period, especially at KCOU and
KUIN. A 50kt southwesterly LLJ will likely produce LLWS conditions
at all terminals between 05-14z.

Specifics for KSTL: MVFR cigs are expected to prevail overnight,
however there may be occasional brief periods of low-end VFR
ceilings. Widely scattered rain showers are possible through the
period. The highest rain chances at KSTL are expected beyond the
end of the 30-hr TAF period. A 50kt southwesterly low level jet
will likely produce LLWS conditions between 05-14z.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 212150
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
350 PM CST Fri Nov 21 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1230 PM CST Fri Nov 21 2014

Low based VFR or high MVFR will continue to move northeast across
the area this afternoon. Rain will begin to move into the area
later this afternoon into the evening hours, though the coverage
is not expected to great enough to warrant more than VCSH at this
point. Later this evening and overnight, a low level jet is
expected to develop over the region which will bring LLWS
conditions at all of the airports. These conditions will last
until around 14Z Saturday morning. Then low based VFR or high MVFR
are expected during Saturday with a low chance of rain.

Specifics for KSTL: Expect mainly low VFR conditions through the
day today until this evening when MVFR ceilings move into the area
with a chance of rain. Expect LLWS conditions overnight with
persistent MVFR ceilings before ceilings rise to VFR during the
day with a continued low chance of rain.

Britt

&&

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

$$

WFO LSX







000
FXUS63 KLSX 212150
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
350 PM CST Fri Nov 21 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1230 PM CST Fri Nov 21 2014

Low based VFR or high MVFR will continue to move northeast across
the area this afternoon. Rain will begin to move into the area
later this afternoon into the evening hours, though the coverage
is not expected to great enough to warrant more than VCSH at this
point. Later this evening and overnight, a low level jet is
expected to develop over the region which will bring LLWS
conditions at all of the airports. These conditions will last
until around 14Z Saturday morning. Then low based VFR or high MVFR
are expected during Saturday with a low chance of rain.

Specifics for KSTL: Expect mainly low VFR conditions through the
day today until this evening when MVFR ceilings move into the area
with a chance of rain. Expect LLWS conditions overnight with
persistent MVFR ceilings before ceilings rise to VFR during the
day with a continued low chance of rain.

Britt

&&

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

$$

WFO LSX








000
FXUS63 KLSX 212150
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
350 PM CST Fri Nov 21 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1230 PM CST Fri Nov 21 2014

Low based VFR or high MVFR will continue to move northeast across
the area this afternoon. Rain will begin to move into the area
later this afternoon into the evening hours, though the coverage
is not expected to great enough to warrant more than VCSH at this
point. Later this evening and overnight, a low level jet is
expected to develop over the region which will bring LLWS
conditions at all of the airports. These conditions will last
until around 14Z Saturday morning. Then low based VFR or high MVFR
are expected during Saturday with a low chance of rain.

Specifics for KSTL: Expect mainly low VFR conditions through the
day today until this evening when MVFR ceilings move into the area
with a chance of rain. Expect LLWS conditions overnight with
persistent MVFR ceilings before ceilings rise to VFR during the
day with a continued low chance of rain.

Britt

&&

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

$$

WFO LSX







000
FXUS63 KLSX 212150
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
350 PM CST Fri Nov 21 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 349 PM CST Fri Nov 21 2014

Will continue the chance of light rain as low level moisture
convergence and large scale ascent increases ahead of shortwave
trough currently moving towards us across the central Plains.  There
are two small areas of rain that have developed ahead of this
system...one over west central Missouri which will move into central
and northeast Missouri later this afternoon and a second over
northern Arkansas which will move into southeast Missouri.  Rain
chances will increase areawide this evening as aforementioned trough
moves across Missouri and Illinois.  Chances will continue through
the night as a 50kt low level jet sets up over the region which will
provide more low level moisture convergence.  At this time it still
appears that precipitation from this event will be mostly liquid as
dewpoints are steadily rising as rain moves into the area.  Both the
HRRR and RUC are showing that the surface wet-bulb temperatures will
be at or above freezing during the onset of precipitation through
early this evening with temperatures continuing to rise through the
late evening hours.

Britt

.LONG TERM:  (Saturday through Next Friday)
Issued at 349 PM CST Fri Nov 21 2014

At least scattered light showers can be expected Saturday and
Saturday night due to low-mid level warm air advection and as a
southwesterly low level jet continues to bring low level moisture
into the area.  The best chance of rain along with the highest
rainfall amounts should occur on Sunday as a southern stream
negatively tilted shortwave moves through the southern Plains and
into the TN Valley region, while an upper level low moves
southeastward into the northern Plains.  There will be upper level
divergence over our area between an upper level jet streak across
the southern Plains and another upper level jet streak across the
Great Lakes region.  A surface low will develop and deepen as it
moves northeastward through the St Louis area around 00z Monday.
There should be at least isolated thunderstorms across portion sof
central and southeast MO and southwest IL.  Temperatures will be
much warmer this weekend and above normal for a change.  Much of the
precipitation should shift east of our forecast area Sunday night as
colder and drier air filters southeastward into the region behind
the surface low and trailing cold front.  There may be some
lingering precipitation Sunday night into Monday morning as
shortwaves move through the area south of the upper level low which
will progress slowly eastward into the Great Lakes region.  The rain
may change over to some light snow across northeast MO and west
central IL late Sunday night and Monday as colder air continues to
advect into the region.  Temperatures will return to below normal
values beginning Monday with both the GFS and ECMWF models dropping
the -8 degree C 850 mb isotherm down to STL by 18z Monday.  Below
normal temperatures are expected from Monday through Thanksgiving
with little if any precipitation as a deep upper level trough moves
slowly eastward through the central US.  The ECMWF model does drop a
northwest flow, clipper type shortwave and associated weak surface
low southeastward through our area which could bring the potential
for a brief period of snow on Wednesday, but the GFS is much weaker
with this feature and only has very light QPF.  A strong surface
ridge will build southeastward into MO for Wednesday night and
Thanksgiving Day with unseasonably cold temperatures expected.

GKS

&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1230 PM CST Fri Nov 21 2014

Low based VFR or high MVFR will continue to move northeast across
the area this afternoon. Rain will begin to move into the area
later this afternoon into the evening hours, though the coverage
is not expected to great enough to warrant more than VCSH at this
point. Later this evening and overnight, a low level jet is
expected to develop over the region which will bring LLWS
conditions at all of the airports. These conditions will last
until around 14Z Saturday morning. Then low based VFR or high MVFR
are expected during Saturday with a low chance of rain.

Specifics for KSTL: Expect mainly low VFR conditions through the
day today until this evening when MVFR ceilings move into the area
with a chance of rain. Expect LLWS conditions overnight with
persistent MVFR ceilings before ceilings rise to VFR during the
day with a continued low chance of rain.

Britt

&&

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

$$

WFO LSX








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