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000
FXUS63 KLSX 300400
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1100 PM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 354 PM CDT Fri Aug 29 2014

Main focus through tonight will be on precipitation chances. Compact
vort max/MCV will be main driver of precipitation through the period.
Tied highest PoPs with track of this feature which current radar
imagery supports as largest coverage of showers with embedded
thunderstorms is just ahead of this feature through early this evening.
Not sure how activity will evolve overnight...but do think that
activity may become more scattered with loss of bulk of daytime
instability and track of vort max to the north of CWA. Therefore...
did lower PoPs back for late tonight. Associated frontal boundary will
slowly ooze south and eastward overnight and begin to washout/stall out
somewhere over the central portion of the CWA bisecting from southwest to
northeast. Temperatures will be seasonably warm...i.e. upper 60s to low
70s and did not deviate from guidance too much.

Gosselin

.LONG TERM:  (Saturday through Next Friday)
Issued at 354 PM CDT Fri Aug 29 2014

Continuing with the short term theme of more scattered convection
associated with this system...have lowered PoPs for Saturday morning
across the entire area.  12Z model guidance from this morning backed
off precipitation chances and QPF for Saturday morning.  The upper
level trof will be flattening out and much of the vorticity will be
moving off to the northeast of the area.  Low level convergence will
be fairly weak and with only weak low level warm advection ahead of
the trof it looks like coverage will be limited.  Expect though as
the day heats up and the atmosphere becomes more unstable we`ll see
coverage increase.  Have therefore kept likely PoPs for Saturday
afternoon...generally along and east of the I-44/I-55 corridor.
Should see storms diminish during the evening with the loss of
daytime heating.

Keeping with the slightly drier trend to the forecast, have lowered
PoPs a bit on Sunday as weak shortwave ridging moves over the CWFA
in the wake of Saturday`s trof.  With no obvious focus for surface
convection showing up in the guidance, think the only real shot for
convective initiation will be orographic effects from the Ozarks.
Therefore have kept chance/slight chance PoPs along and south of the
I-70 corridor Sunday assuming there will be scattered storms down
there which will migrate northeastward.

Little change to the forecast for next week...other than to bump up
temperatures a little for Thursday and Friday.  The next shortwave
is still on track to dig into the Great Plains on Sunday
evening...moving into the Midwest by Monday morning.  While medium
range guidance is in general agreement with the timing of the wave,
the GFS shows a sharper/deeper wave while the ECMWF is less
amplified.  The surface front is still forecast to dip into central
Missouri before stalling Monday night.  The front remains over
Missouri and southern Illinois on Tuesday providing a focus for
convective development.  Have kept likely PoP Sunday night into
Monday night as the front moves in and lingering chance PoPs
continuing into midweek.  As the front moves back to the north
Thursday and Friday have lowered to slight chance and increased
temps as the upper level ridge builds back across the central U.S.

Carney

&&

.AVIATION:  (For the 06z TAFs through 06z Saturday Night)
Issued at 1042 PM CDT Fri Aug 29 2014

There were two areas of showers and storms this evening. The first
was across southeast MO and will likely remain southeast of the
taf sites late tonight, although they could get close to CPS.
There were scattered showers/storms across northwest MO ahead of
an approaching upper level disturbance which may impact the UIN
area late tonight. May include VCTS in the UIN taf. It appears
that there will be enough cloud cover and strong enough surface
winds to deter fog formation, although could not rule out light
fog late tonight/early Saturday morning in SUS and CPS where the
surface wind will be a little lighter and in areas which had
significant rainfall this evening. Should be at least scattered
showers/storms in the St Louis metro area Saturday afternoon along
and ahead of weakening cold front/surface trough dropping
southeastward through the area. Sly surface winds will become
more swly late tonight and Saturday morning.

Specifics for KSTL: Current shower/storm activity on radar will
likely miss STL late tonight, although could not rule out a
passing sprinkle. Will likely leave STL taf dry late tonight and
Saturday morning due to uncertainty in coverage and timing of
additional convection. Will include VCTS in the taf Saturday
afternoon with at least scattered showers/storms expected at this
time due to diurnal destabilization along and ahead of a weak
surface trough/cold front. Prevailing s-swly surface winds through
the period.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     73  87  73  87 /  50  60  30  20
Quincy          69  85  67  86 /  40  40  10  10
Columbia        68  88  68  89 /  40  40  20  10
Jefferson City  68  87  69  89 /  40  40  20  10
Salem           71  85  71  84 /  60  60  50  30
Farmington      71  85  69  85 /  50  60  50  30

&&

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

$$

WFO LSX








000
FXUS63 KLSX 292300
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
600 PM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 354 PM CDT Fri Aug 29 2014

Main focus through tonight will be on precipitation chances. Compact
vort max/MCV will be main driver of precipitation through the period.
Tied highest PoPs with track of this feature which current radar
imagery supports as largest coverage of showers with embedded
thunderstorms is just ahead of this feature through early this evening.
Not sure how activity will evolve overnight...but do think that
activity may become more scattered with loss of bulk of daytime
instability and track of vort max to the north of CWA. Therefore...
did lower PoPs back for late tonight. Associated frontal boundary will
slowly ooze south and eastward overnight and begin to washout/stall out
somewhere over the central portion of the CWA bisecting from southwest to
northeast. Temperatures will be seasonably warm...i.e. upper 60s to low
70s and did not deviate from guidance too much.

Gosselin

.LONG TERM:  (Saturday through Next Friday)
Issued at 354 PM CDT Fri Aug 29 2014

Continuing with the short term theme of more scattered convection
associated with this system...have lowered PoPs for Saturday morning
across the entire area.  12Z model guidance from this morning backed
off precipitation chances and QPF for Saturday morning.  The upper
level trof will be flattening out and much of the vorticity will be
moving off to the northeast of the area.  Low level convergence will
be fairly weak and with only weak low level warm advection ahead of
the trof it looks like coverage will be limited.  Expect though as
the day heats up and the atmosphere becomes more unstable we`ll see
coverage increase.  Have therefore kept likely PoPs for Saturday
afternoon...generally along and east of the I-44/I-55 corridor.
Should see storms diminish during the evening with the loss of
daytime heating.

Keeping with the slightly drier trend to the forecast, have lowered
PoPs a bit on Sunday as weak shortwave ridging moves over the CWFA
in the wake of Saturday`s trof.  With no obvious focus for surface
convection showing up in the guidance, think the only real shot for
convective initiation will be orographic effects from the Ozarks.
Therefore have kept chance/slight chance PoPs along and south of the
I-70 corridor Sunday assuming there will be scattered storms down
there which will migrate northeastward.

Little change to the forecast for next week...other than to bump up
temperatures a little for Thursday and Friday.  The next shortwave
is still on track to dig into the Great Plains on Sunday
evening...moving into the Midwest by Monday morning.  While medium
range guidance is in general agreement with the timing of the wave,
the GFS shows a sharper/deeper wave while the ECMWF is less
amplified.  The surface front is still forecast to dip into central
Missouri before stalling Monday night.  The front remains over
Missouri and southern Illinois on Tuesday providing a focus for
convective development.  Have kept likely PoP Sunday night into
Monday night as the front moves in and lingering chance PoPs
continuing into midweek.  As the front moves back to the north
Thursday and Friday have lowered to slight chance and increased
temps as the upper level ridge builds back across the central U.S.

Carney

&&

.AVIATION:  (For the 00z TAFs through 00z Saturday Evening)
Issued at 526 PM CDT Fri Aug 29 2014

North to south band of showers/storms moving through UIN will
also move through STL and SUS early this evening, although much of
this activity may shift east of the taf sites shortly after 00z
this evening. There will likely be widely scattered showers/storms
for at least the remainder of the evening and overnight due to
approaching upper level disturbance, but may leave the tafs dry.
It appears that there will be enough cloud cover and strong
enough surface winds to deter fog formation, although could not
rule out light fog late tonight/early Saturday morning in SUS and
CPS where the surface wind will be a little lighter and in areas
which get significant rainfall this evening. Should be at least
scattered showers/storms in the St Louis metro area Saturday
afternoon along and ahead of weakening cold front/surface trough.

Specifics for KSTL: Band of showers and storms will move through
STL around 00z this evening, with widely scattered showers/storms
still possible for the late evening and overnight. Will include
showers/storms in the STL taf until at least 01z this evening, but
may leave taf dry for the rest of the night into Saturday morning
due to uncertainty in coverage and timing of additional
convection. Will include VCTS in the taf Saturday afternoon with
at least scattered showers/storms expected at this time due to
diurnal destabilization along and ahead of a weak surface
trough/cold front. Prevailing s-swly surface winds through the
period.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     73  87  73  87 /  60  60  30  20
Quincy          69  85  67  86 /  60  40  10  10
Columbia        68  88  68  89 /  40  40  20  10
Jefferson City  68  87  69  89 /  40  40  20  10
Salem           71  85  71  84 /  50  60  50  30
Farmington      71  85  69  85 /  50  60  50  30

&&

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

$$

WFO LSX







000
FXUS63 KLSX 292300
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
600 PM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 354 PM CDT Fri Aug 29 2014

Main focus through tonight will be on precipitation chances. Compact
vort max/MCV will be main driver of precipitation through the period.
Tied highest PoPs with track of this feature which current radar
imagery supports as largest coverage of showers with embedded
thunderstorms is just ahead of this feature through early this evening.
Not sure how activity will evolve overnight...but do think that
activity may become more scattered with loss of bulk of daytime
instability and track of vort max to the north of CWA. Therefore...
did lower PoPs back for late tonight. Associated frontal boundary will
slowly ooze south and eastward overnight and begin to washout/stall out
somewhere over the central portion of the CWA bisecting from southwest to
northeast. Temperatures will be seasonably warm...i.e. upper 60s to low
70s and did not deviate from guidance too much.

Gosselin

.LONG TERM:  (Saturday through Next Friday)
Issued at 354 PM CDT Fri Aug 29 2014

Continuing with the short term theme of more scattered convection
associated with this system...have lowered PoPs for Saturday morning
across the entire area.  12Z model guidance from this morning backed
off precipitation chances and QPF for Saturday morning.  The upper
level trof will be flattening out and much of the vorticity will be
moving off to the northeast of the area.  Low level convergence will
be fairly weak and with only weak low level warm advection ahead of
the trof it looks like coverage will be limited.  Expect though as
the day heats up and the atmosphere becomes more unstable we`ll see
coverage increase.  Have therefore kept likely PoPs for Saturday
afternoon...generally along and east of the I-44/I-55 corridor.
Should see storms diminish during the evening with the loss of
daytime heating.

Keeping with the slightly drier trend to the forecast, have lowered
PoPs a bit on Sunday as weak shortwave ridging moves over the CWFA
in the wake of Saturday`s trof.  With no obvious focus for surface
convection showing up in the guidance, think the only real shot for
convective initiation will be orographic effects from the Ozarks.
Therefore have kept chance/slight chance PoPs along and south of the
I-70 corridor Sunday assuming there will be scattered storms down
there which will migrate northeastward.

Little change to the forecast for next week...other than to bump up
temperatures a little for Thursday and Friday.  The next shortwave
is still on track to dig into the Great Plains on Sunday
evening...moving into the Midwest by Monday morning.  While medium
range guidance is in general agreement with the timing of the wave,
the GFS shows a sharper/deeper wave while the ECMWF is less
amplified.  The surface front is still forecast to dip into central
Missouri before stalling Monday night.  The front remains over
Missouri and southern Illinois on Tuesday providing a focus for
convective development.  Have kept likely PoP Sunday night into
Monday night as the front moves in and lingering chance PoPs
continuing into midweek.  As the front moves back to the north
Thursday and Friday have lowered to slight chance and increased
temps as the upper level ridge builds back across the central U.S.

Carney

&&

.AVIATION:  (For the 00z TAFs through 00z Saturday Evening)
Issued at 526 PM CDT Fri Aug 29 2014

North to south band of showers/storms moving through UIN will
also move through STL and SUS early this evening, although much of
this activity may shift east of the taf sites shortly after 00z
this evening. There will likely be widely scattered showers/storms
for at least the remainder of the evening and overnight due to
approaching upper level disturbance, but may leave the tafs dry.
It appears that there will be enough cloud cover and strong
enough surface winds to deter fog formation, although could not
rule out light fog late tonight/early Saturday morning in SUS and
CPS where the surface wind will be a little lighter and in areas
which get significant rainfall this evening. Should be at least
scattered showers/storms in the St Louis metro area Saturday
afternoon along and ahead of weakening cold front/surface trough.

Specifics for KSTL: Band of showers and storms will move through
STL around 00z this evening, with widely scattered showers/storms
still possible for the late evening and overnight. Will include
showers/storms in the STL taf until at least 01z this evening, but
may leave taf dry for the rest of the night into Saturday morning
due to uncertainty in coverage and timing of additional
convection. Will include VCTS in the taf Saturday afternoon with
at least scattered showers/storms expected at this time due to
diurnal destabilization along and ahead of a weak surface
trough/cold front. Prevailing s-swly surface winds through the
period.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     73  87  73  87 /  60  60  30  20
Quincy          69  85  67  86 /  60  40  10  10
Columbia        68  88  68  89 /  40  40  20  10
Jefferson City  68  87  69  89 /  40  40  20  10
Salem           71  85  71  84 /  50  60  50  30
Farmington      71  85  69  85 /  50  60  50  30

&&

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

$$

WFO LSX








000
FXUS63 KLSX 292055
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
355 PM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 354 PM CDT Fri Aug 29 2014

Main focus through tonight will be on precipitation chances. Compact
vort max/MCV will be main driver of precipitation through the period.
Tied highest PoPs with track of this feature which current radar
imagery supports as largest coverage of showers with embedded
thunderstorms is just ahead of this feature through early this evening.
Not sure how activity will evolve overnight...but do think that
activity may become more scattered with loss of bulk of daytime
instability and track of vort max to the north of CWA. Therefore...
did lower PoPs back for late tonight. Associated frontal boundary will
slowly ooze south and eastward overnigh and begin to washout/stall out
somewhere over the central portion of the CWA bisecting from southwest to
northeast. Temperatures will be seasonably warm...i.e. upper 60s to low
70s and did not deviate from guidance too much.

Gosselin

.LONG TERM:  (Saturday through Next Friday)
Issued at 354 PM CDT Fri Aug 29 2014

Continuing with the short term theme of more scattered convection
associated with this system...have lowered PoPs for Saturday morning
across the entire area.  12Z model guidance from this morning backed
off precipitation chances and QPF for Saturday morning.  The upper
level trof will be flattening out and much of the vorticity will be
moving off to the northeast of the area.  Low level convergence will
be fairly weak and with only weak low level warm advection ahead of
the trof it looks like coverage will be limited.  Expect though as
the day heats up and the atmosphere becomes more unstable we`ll see
coverage increase.  Have therefore kept likely PoPs for Saturday
afternoon...generally along and east of the I-44/I-55 corridor.
Should see storms diminish during the evening with the loss of
daytime heating.

Keeping with the slightly drier trend to the forecast, have lowered
PoPs a bit on Sunday as weak shortwave ridging moves over the CWFA
in the wake of Saturday`s trof.  With no obvious focus for surface
convection showing up in the guidance, think the only real shot for
convective initiation will be orographic effects from the Ozarks.
Therefore have kept chance/slight chance PoPs along and south of the
I-70 corridor Sunday assuming there will be scattered storms down
there which will migrate northeastward.

Little change to the forecast for next week...other than to bump up
temperatures a little for Thursday and Friday.  The next shortwave
is still on track to dig into the Great Plains on Sunday
evening...moving into the Midwest by Monday morning.  While medium
range guidance is in general agreement with the timing of the wave,
the GFS shows a sharper/deeper wave while the ECMWF is less
amplified.  The surface front is still forecast to dip into central
Missouri before stalling Monday night.  The front remains over
Missouri and southern Illinois on Tuesday providing a focus for
convective development.  Have kept likely PoP Sunday night into
Monday night as the front moves in and lingering chance PoPs
continuing into midweek.  As the front moves back to the north
Thursday and Friday have lowered to slight chance and increased
temps as the upper level ridge builds back across the central U.S.

Carney

&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1205 PM CDT Fri Aug 29 2014

Focus over the next 24-30 hours will be on the chances of showers
and thunderstorms affecting the terminals. Band of showers and
thunderstorms ahead of a midlevel impulse is expected to translate
slowly eastward across the area through the day/night. Did my best
to time this area with convection first affecting KCOU this
afternoon...and rest of terminals by early evening. Broken line of
activity may weaken a bit and break up later on tonight as
stronger forcing for ascent translates north and east.
Precipitation should move off to the east of terminals by late
tonight though cannot rule out lingering showers or perhaps a
storm really anytime as associated cold front stalls out and never
really makes it through the area. Winds will veer to the southwest
and eventually to the west/southwest at KCOU and KUIN behind
boundary.


Specifics for KSTL:

Focus over the next 24-30 hours will be on the chances of showers
and thunderstorms affecting Lambert Field. Band of showers and
thunderstorms ahead of a midlevel impulse is expected to translate
slowly eastward across the area through the day/night. Showers
with embedded thunder possible is likely late this evening into
the early overnight period with visibilities possibly dipping into
MVFR or even IFR in heavier activity. Precipitation should move
off to the east of terminal by late tonight though cannot rule
out lingering showers or perhaps a storm really anytime as
associated cold front stalls out and never really makes it through
the area. Slightly better chance of showers and storms may
redevelop during the day tomorrow...especially along/in vicinity
of old cold front. Winds will remain out of the south and veer
to the southwest tomorrow afternoon.

Gosselin

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     73  87  73  87 /  60  60  30  20
Quincy          69  85  67  86 /  60  40  10  10
Columbia        68  88  68  89 /  40  40  20  10
Jefferson City  68  87  69  89 /  40  40  20  10
Salem           71  85  71  84 /  50  60  50  30
Farmington      71  85  69  85 /  50  60  50  30

&&

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

$$

WFO LSX







000
FXUS63 KLSX 292055
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
355 PM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 354 PM CDT Fri Aug 29 2014

Main focus through tonight will be on precipitation chances. Compact
vort max/MCV will be main driver of precipitation through the period.
Tied highest PoPs with track of this feature which current radar
imagery supports as largest coverage of showers with embedded
thunderstorms is just ahead of this feature through early this evening.
Not sure how activity will evolve overnight...but do think that
activity may become more scattered with loss of bulk of daytime
instability and track of vort max to the north of CWA. Therefore...
did lower PoPs back for late tonight. Associated frontal boundary will
slowly ooze south and eastward overnigh and begin to washout/stall out
somewhere over the central portion of the CWA bisecting from southwest to
northeast. Temperatures will be seasonably warm...i.e. upper 60s to low
70s and did not deviate from guidance too much.

Gosselin

.LONG TERM:  (Saturday through Next Friday)
Issued at 354 PM CDT Fri Aug 29 2014

Continuing with the short term theme of more scattered convection
associated with this system...have lowered PoPs for Saturday morning
across the entire area.  12Z model guidance from this morning backed
off precipitation chances and QPF for Saturday morning.  The upper
level trof will be flattening out and much of the vorticity will be
moving off to the northeast of the area.  Low level convergence will
be fairly weak and with only weak low level warm advection ahead of
the trof it looks like coverage will be limited.  Expect though as
the day heats up and the atmosphere becomes more unstable we`ll see
coverage increase.  Have therefore kept likely PoPs for Saturday
afternoon...generally along and east of the I-44/I-55 corridor.
Should see storms diminish during the evening with the loss of
daytime heating.

Keeping with the slightly drier trend to the forecast, have lowered
PoPs a bit on Sunday as weak shortwave ridging moves over the CWFA
in the wake of Saturday`s trof.  With no obvious focus for surface
convection showing up in the guidance, think the only real shot for
convective initiation will be orographic effects from the Ozarks.
Therefore have kept chance/slight chance PoPs along and south of the
I-70 corridor Sunday assuming there will be scattered storms down
there which will migrate northeastward.

Little change to the forecast for next week...other than to bump up
temperatures a little for Thursday and Friday.  The next shortwave
is still on track to dig into the Great Plains on Sunday
evening...moving into the Midwest by Monday morning.  While medium
range guidance is in general agreement with the timing of the wave,
the GFS shows a sharper/deeper wave while the ECMWF is less
amplified.  The surface front is still forecast to dip into central
Missouri before stalling Monday night.  The front remains over
Missouri and southern Illinois on Tuesday providing a focus for
convective development.  Have kept likely PoP Sunday night into
Monday night as the front moves in and lingering chance PoPs
continuing into midweek.  As the front moves back to the north
Thursday and Friday have lowered to slight chance and increased
temps as the upper level ridge builds back across the central U.S.

Carney

&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1205 PM CDT Fri Aug 29 2014

Focus over the next 24-30 hours will be on the chances of showers
and thunderstorms affecting the terminals. Band of showers and
thunderstorms ahead of a midlevel impulse is expected to translate
slowly eastward across the area through the day/night. Did my best
to time this area with convection first affecting KCOU this
afternoon...and rest of terminals by early evening. Broken line of
activity may weaken a bit and break up later on tonight as
stronger forcing for ascent translates north and east.
Precipitation should move off to the east of terminals by late
tonight though cannot rule out lingering showers or perhaps a
storm really anytime as associated cold front stalls out and never
really makes it through the area. Winds will veer to the southwest
and eventually to the west/southwest at KCOU and KUIN behind
boundary.


Specifics for KSTL:

Focus over the next 24-30 hours will be on the chances of showers
and thunderstorms affecting Lambert Field. Band of showers and
thunderstorms ahead of a midlevel impulse is expected to translate
slowly eastward across the area through the day/night. Showers
with embedded thunder possible is likely late this evening into
the early overnight period with visibilities possibly dipping into
MVFR or even IFR in heavier activity. Precipitation should move
off to the east of terminal by late tonight though cannot rule
out lingering showers or perhaps a storm really anytime as
associated cold front stalls out and never really makes it through
the area. Slightly better chance of showers and storms may
redevelop during the day tomorrow...especially along/in vicinity
of old cold front. Winds will remain out of the south and veer
to the southwest tomorrow afternoon.

Gosselin

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     73  87  73  87 /  60  60  30  20
Quincy          69  85  67  86 /  60  40  10  10
Columbia        68  88  68  89 /  40  40  20  10
Jefferson City  68  87  69  89 /  40  40  20  10
Salem           71  85  71  84 /  50  60  50  30
Farmington      71  85  69  85 /  50  60  50  30

&&

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

$$

WFO LSX








000
FXUS63 KLSX 291721
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1221 PM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Sunday night)
Issued at 326 AM CDT Fri Aug 29 2014

The primary forecast concern over the next 7 days is precipitation
chances.

An upper trough axis is forecast to move across the area
today/tomorrow accompanied by SH/TS. A surface low moving into
the Great Lakes will drag a cold front into MO/IL on Sat, but the
temperature gradient is forecast to be fairly weak and this looks
like more of a gentle wind shift line rather than a true exchange
of air masses. Even so, models show a secondary vort max clipping
the northern CWA on Sat and the wind shift line might act as a
focus for SH/TS development. It doesn`t look like solid rain for
the whole weekend, but it`s tough to rule out scattered SH/TS in
almost any forecast period because isentropic ascent starts to
increase ahead of the next trough almost as soon as the Fri/Sat
trough moves away from the area. The most likely time period for
mostly dry weather across most of the LSX CWA appears to be from
late Sat night through late Sun morning.

Kanofsky

.LONG TERM: (Monday through Thursday)
Issued at 326 AM CDT Fri Aug 29 2014

Precipitation chances increase again on Mon/Mon night ahead of an
approaching longwave trough. With several embedded vorticity
maxima moving through the base of the broad trough, scattered
SH/TS will be possible across MO/IL through Tue as a cold front
sinks towards the MO/IA border. The best opportunity for
precipitation appears to be on Mon morning as the nocturnal LLJ
veers and becomes focused across the CWA. The temperature gradient
is forecast to be stronger with this front compared to the
previous one, but models still show that the synoptic front never
makes it very far into MO before it is lifted back northward as a
warm front. Broad upper troughing then gives way to quasizonal
flow by Tue night followed by weak upper ridging towards the end
of the week.

Temperatures look seasonally warm, although there is more
uncertainty with temps on days when precipitation is expected.
If recent model runs are correct with the expansion of the upper
high over the southeastern CONUS, then expect a warming trend for
late next week.

Kanofsky

&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1205 PM CDT Fri Aug 29 2014

Focus over the next 24-30 hours will be on the chances of showers
and thunderstorms affecting the terminals. Band of showers and
thunderstorms ahead of a midlevel impulse is expected to translate
slowly eastward across the area through the day/night. Did my best
to time this area with convection first affecting KCOU this
afternoon...and rest of terminals by early evening. Broken line of
activity may weaken a bit and break up later on tonight as
stronger forcing for ascent translates north and east.
Precipitation should move off to the east of terminals by late
tonight though cannot rule out lingering showers or perhaps a
storm really anytime as associated cold front stalls out and never
really makes it through the area. Winds will veer to the southwest
and eventually to the west/southwest at KCOU and KUIN behind
boundary.


Specifics for KSTL:

Focus over the next 24-30 hours will be on the chances of showers
and thunderstorms affecting Lambert Field. Band of showers and
thunderstorms ahead of a midlevel impulse is expected to translate
slowly eastward across the area through the day/night. Showers
with embedded thunder possible is likely late this evening into
the early overnight period with visibilities possibly dipping into
MVFR or even IFR in heavier activity. Precipitation should move
off to the east of terminal by late tonight though cannot rule
out lingering showers or perhaps a storm really anytime as
associated cold front stalls out and never really makes it through
the area. Slightly better chance of showers and storms may
redevelop during the day tomorrow...especially along/in vicinity
of old cold front. Winds will remain out of the south and veer
to the southwest tomorrow afternoon.

Gosselin

&&

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

$$

WFO LSX








000
FXUS63 KLSX 291721
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1221 PM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Sunday night)
Issued at 326 AM CDT Fri Aug 29 2014

The primary forecast concern over the next 7 days is precipitation
chances.

An upper trough axis is forecast to move across the area
today/tomorrow accompanied by SH/TS. A surface low moving into
the Great Lakes will drag a cold front into MO/IL on Sat, but the
temperature gradient is forecast to be fairly weak and this looks
like more of a gentle wind shift line rather than a true exchange
of air masses. Even so, models show a secondary vort max clipping
the northern CWA on Sat and the wind shift line might act as a
focus for SH/TS development. It doesn`t look like solid rain for
the whole weekend, but it`s tough to rule out scattered SH/TS in
almost any forecast period because isentropic ascent starts to
increase ahead of the next trough almost as soon as the Fri/Sat
trough moves away from the area. The most likely time period for
mostly dry weather across most of the LSX CWA appears to be from
late Sat night through late Sun morning.

Kanofsky

.LONG TERM: (Monday through Thursday)
Issued at 326 AM CDT Fri Aug 29 2014

Precipitation chances increase again on Mon/Mon night ahead of an
approaching longwave trough. With several embedded vorticity
maxima moving through the base of the broad trough, scattered
SH/TS will be possible across MO/IL through Tue as a cold front
sinks towards the MO/IA border. The best opportunity for
precipitation appears to be on Mon morning as the nocturnal LLJ
veers and becomes focused across the CWA. The temperature gradient
is forecast to be stronger with this front compared to the
previous one, but models still show that the synoptic front never
makes it very far into MO before it is lifted back northward as a
warm front. Broad upper troughing then gives way to quasizonal
flow by Tue night followed by weak upper ridging towards the end
of the week.

Temperatures look seasonally warm, although there is more
uncertainty with temps on days when precipitation is expected.
If recent model runs are correct with the expansion of the upper
high over the southeastern CONUS, then expect a warming trend for
late next week.

Kanofsky

&&

.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1205 PM CDT Fri Aug 29 2014

Focus over the next 24-30 hours will be on the chances of showers
and thunderstorms affecting the terminals. Band of showers and
thunderstorms ahead of a midlevel impulse is expected to translate
slowly eastward across the area through the day/night. Did my best
to time this area with convection first affecting KCOU this
afternoon...and rest of terminals by early evening. Broken line of
activity may weaken a bit and break up later on tonight as
stronger forcing for ascent translates north and east.
Precipitation should move off to the east of terminals by late
tonight though cannot rule out lingering showers or perhaps a
storm really anytime as associated cold front stalls out and never
really makes it through the area. Winds will veer to the southwest
and eventually to the west/southwest at KCOU and KUIN behind
boundary.


Specifics for KSTL:

Focus over the next 24-30 hours will be on the chances of showers
and thunderstorms affecting Lambert Field. Band of showers and
thunderstorms ahead of a midlevel impulse is expected to translate
slowly eastward across the area through the day/night. Showers
with embedded thunder possible is likely late this evening into
the early overnight period with visibilities possibly dipping into
MVFR or even IFR in heavier activity. Precipitation should move
off to the east of terminal by late tonight though cannot rule
out lingering showers or perhaps a storm really anytime as
associated cold front stalls out and never really makes it through
the area. Slightly better chance of showers and storms may
redevelop during the day tomorrow...especially along/in vicinity
of old cold front. Winds will remain out of the south and veer
to the southwest tomorrow afternoon.

Gosselin

&&

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

$$

WFO LSX







000
FXUS63 KLSX 291148
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
648 AM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Sunday night)
Issued at 326 AM CDT Fri Aug 29 2014

The primary forecast concern over the next 7 days is precipitation
chances.

An upper trough axis is forecast to move across the area
today/tomorrow accompanied by SH/TS. A surface low moving into
the Great Lakes will drag a cold front into MO/IL on Sat, but the
temperature gradient is forecast to be fairly weak and this looks
like more of a gentle wind shift line rather than a true exchange
of air masses. Even so, models show a secondary vort max clipping
the northern CWA on Sat and the wind shift line might act as a
focus for SH/TS development. It doesn`t look like solid rain for
the whole weekend, but it`s tough to rule out scattered SH/TS in
almost any forecast period because isentropic ascent starts to
increase ahead of the next trough almost as soon as the Fri/Sat
trough moves away from the area. The most likely time period for
mostly dry weather across most of the LSX CWA appears to be from
late Sat night through late Sun morning.

Kanofsky

.LONG TERM: (Monday through Thursday)
Issued at 326 AM CDT Fri Aug 29 2014

Precipitation chances increase again on Mon/Mon night ahead of an
approaching longwave trough. With several embedded vorticity
maxima moving through the base of the broad trough, scattered
SH/TS will be possible across MO/IL through Tue as a cold front
sinks towards the MO/IA border. The best opportunity for
precipitation appears to be on Mon morning as the nocturnal LLJ
veers and becomes focused across the CWA. The temperature gradient
is forecast to be stronger with this front compared to the
previous one, but models still show that the synoptic front never
makes it very far into MO before it is lifted back northward as a
warm front. Broad upper troughing then gives way to quasizonal
flow by Tue night followed by weak upper ridging towards the end
of the week.

Temperatures look seasonally warm, although there is more
uncertainty with temps on days when precipitation is expected.
If recent model runs are correct with the expansion of the upper
high over the southeastern CONUS, then expect a warming trend for
late next week.

Kanofsky

&&

.AVIATION:  (For the 12z TAFs through 12z Saturday Morning)
Issued at 638 AM CDT Fri Aug 29 2014

Precipitation chances will be on the increase tonight as a
weakening short wave trof move across the area. Models all seem
to agree that the accompanying surface cold front will not make
it across the area. With upper level support weakening and no
strong forcing at the surface, other than outflows, that puts
some question into the timing and coverage of the precipitaton.
Have thus settled for prob30s for this evening and overnight.

Specifics for KSTL: Will maintain vcts for this afternoon,
although with the warm front further north, suspect the coverage
may be less. Question is with the approaching but weakening system
tonight. Models all want to bring in precipitation, but seem to
what to highlight areas to the north and south. A prob30 looks
good for this evening and overnight.

JPK

&&

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

$$

WFO LSX







000
FXUS63 KLSX 291148
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
648 AM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Sunday night)
Issued at 326 AM CDT Fri Aug 29 2014

The primary forecast concern over the next 7 days is precipitation
chances.

An upper trough axis is forecast to move across the area
today/tomorrow accompanied by SH/TS. A surface low moving into
the Great Lakes will drag a cold front into MO/IL on Sat, but the
temperature gradient is forecast to be fairly weak and this looks
like more of a gentle wind shift line rather than a true exchange
of air masses. Even so, models show a secondary vort max clipping
the northern CWA on Sat and the wind shift line might act as a
focus for SH/TS development. It doesn`t look like solid rain for
the whole weekend, but it`s tough to rule out scattered SH/TS in
almost any forecast period because isentropic ascent starts to
increase ahead of the next trough almost as soon as the Fri/Sat
trough moves away from the area. The most likely time period for
mostly dry weather across most of the LSX CWA appears to be from
late Sat night through late Sun morning.

Kanofsky

.LONG TERM: (Monday through Thursday)
Issued at 326 AM CDT Fri Aug 29 2014

Precipitation chances increase again on Mon/Mon night ahead of an
approaching longwave trough. With several embedded vorticity
maxima moving through the base of the broad trough, scattered
SH/TS will be possible across MO/IL through Tue as a cold front
sinks towards the MO/IA border. The best opportunity for
precipitation appears to be on Mon morning as the nocturnal LLJ
veers and becomes focused across the CWA. The temperature gradient
is forecast to be stronger with this front compared to the
previous one, but models still show that the synoptic front never
makes it very far into MO before it is lifted back northward as a
warm front. Broad upper troughing then gives way to quasizonal
flow by Tue night followed by weak upper ridging towards the end
of the week.

Temperatures look seasonally warm, although there is more
uncertainty with temps on days when precipitation is expected.
If recent model runs are correct with the expansion of the upper
high over the southeastern CONUS, then expect a warming trend for
late next week.

Kanofsky

&&

.AVIATION:  (For the 12z TAFs through 12z Saturday Morning)
Issued at 638 AM CDT Fri Aug 29 2014

Precipitation chances will be on the increase tonight as a
weakening short wave trof move across the area. Models all seem
to agree that the accompanying surface cold front will not make
it across the area. With upper level support weakening and no
strong forcing at the surface, other than outflows, that puts
some question into the timing and coverage of the precipitaton.
Have thus settled for prob30s for this evening and overnight.

Specifics for KSTL: Will maintain vcts for this afternoon,
although with the warm front further north, suspect the coverage
may be less. Question is with the approaching but weakening system
tonight. Models all want to bring in precipitation, but seem to
what to highlight areas to the north and south. A prob30 looks
good for this evening and overnight.

JPK

&&

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

$$

WFO LSX








000
FXUS63 KLSX 290836
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
336 AM CDT Fri Aug 29 2014

.SHORT TERM:  (Through Sunday night)
Issued at 326 AM CDT Fri Aug 29 2014

The primary forecast concern over the next 7 days is precipitation
chances.

An upper trough axis is forecast to move across the area
today/tomorrow accompanied by SH/TS. A surface low moving into
the Great Lakes will drag a cold front into MO/IL on Sat, but the
temperature gradient is forecast to be fairly weak and this looks
like more of a gentle wind shift line rather than a true exchange
of air masses. Even so, models show a secondary vort max clipping
the northern CWA on Sat and the wind shift line might act as a
focus for SH/TS development. It doesn`t look like solid rain for
the whole weekend, but it`s tough to rule out scattered SH/TS in
almost any forecast period because isentropic ascent starts to
increase ahead of the next trough almost as soon as the Fri/Sat
trough moves away from the area. The most likely time period for
mostly dry weather across most of the LSX CWA appears to be from
late Sat night through late Sun morning.

Kanofsky

.LONG TERM: (Monday through Thursday)
Issued at 326 AM CDT Fri Aug 29 2014

Precipitation chances increase again on Mon/Mon night ahead of an
approaching longwave trough. With several embedded vorticity
maxima moving through the base of the broad trough, scattered
SH/TS will be possible across MO/IL through Tue as a cold front
sinks towards the MO/IA border. The best opportunity for
precipitation appears to be on Mon morning as the nocturnal LLJ
veers and becomes focused across the CWA. The temperature gradient
is forecast to be stronger with this front compared to the
previous one, but models still show that the synoptic front never
makes it very far into MO before it is lifted back northward as a
warm front. Broad upper troughing then gives way to quasizonal
flow by Tue night followed by weak upper ridging towards the end
of the week.

Temperatures look seasonally warm, although there is more
uncertainty with temps on days when precipitation is expected.
If recent model runs are correct with the expansion of the upper
high over the southeastern CONUS, then expect a warming trend for
late next week.

Kanofsky

&&

.AVIATION:  (For the 06z TAFs through 06z Friday Night)
Issued at 1105 PM CDT Thu Aug 28 2014

The GFS model appears overdone with its precipitation forecast
late tonight and will keep tafs dry. There may be a little fog
late tonight/early Friday morning, mainly in the St Louis metro
area, and especially where there was recent rainfall early this
evening. The MOS guidance does not have as low of vsbys as it has
forecast the past few nights. It appears that the surface wind in
UIN and COU will be a little stronger than the previous couple of
nights. Sely surface wind late tonight will become sly on Friday
with scattered storms expected again during the late afternoon and
evening hours due to unstable conditions ahead of an approaching
upper level disturbance.

Specifics for KSTL: A light sely surface wind late tonight will
become sly on Friday and increase to 9-11 kts in the afternoon.
Scattered diurnal cumulus clouds should develop late Friday
morning and afternoon with scattered storms in the late afternoon
and evening.

GKS

&&

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

$$

WFO LSX








000
FXUS63 KLSX 290423
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1123 PM CDT Thu Aug 28 2014

.SHORT TERM: (Tonight - Saturday)
Issued at 400 PM CDT Thu Aug 28 2014

Expect that convection from this afternoon will bleed over into
this evening before dissipating much like Wednesday night. Models
are redeveloping some nocturnal convection ahead of the trof in
the Plains to varying degrees, with the most bullish being the GFS
after midnight. The GFS cranks out .75 inch along and east of the
Mississippi river from St. Louis north. While I cannot totally
rule out overnight convection, the low level jet is pretty weak
and most of the isentropic lift will be well north of the area.
Have largely discounted the GFS for these reasons and only kept
slight chance/isolated PoPs overnight primarily for
northeast/northern zones.

Timing issues remain the primary problem for the approaching trof
Friday through Saturday.  Still thinking some scattered
thunderstorms will be possible Friday afternoon ahead of the trof;
but overall the models came in a bit faster with the eastward
progression.  Have sped up the introduction of likely PoPs Friday
night, and ended the likely PoPs sooner on Saturday.  Still holding
onto a chance/slight chance PoPs Saturday night as warm advection
aloft is forecast to begin again ahead of the next trof.  Seasonably
warm temperatures remain in the forecast through Saturday, though
highs will be very dependent on convection, especially on Saturday
afternoon.

Carney

.LONG TERM: (Sunday - Thursday)
Issued at 400 PM CDT Thu Aug 28 2014

Sunday should be drier than Saturday as the area will be stuck
between trofs with weak ridging overhead.  Can`t rule out scattered
afternoon storms over the southeast Missouri and southern Illinois.
The next trof in line is still forecast to move into the Midwest on
Monday.  There seems to be a little less agreement in the medium
range models on how far the south the associated cold front will
get.  Between the ECMWF and the GFS, the EC is further south with
the cold front, stalling it out near or just south of the I-70
corridor while the GFS keeps it further north near a line from St.
Joseph to Kirksville to Quincy.  Regardless, it looks like another
good chance for rain for parts of the area...primarily along and
north of the I-70 corridor Sunday night through Monday night or even
Tuesday.  The front will move back to the north Tuesday night and
Wednesday, but the GFS develops another round of convection Tuesday
night which pushes the effective front south into Arkansas
Wednesday.  This looks much less likely to me than the ECMWF
solution which simply pushes the front back to the north and allows
the heat to build back across the area.  Stuck pretty close to the
initial model blend for weather and temperatures Wednesday and
Thursday which keep highs in the mid to upper 80s, but this may be
too cool.  Will monitor trends and adjust over the next couple of
days as the models hopefully get a better handle on next week.

Carney

&&

.AVIATION:  (For the 06z TAFs through 06z Friday Night)
Issued at 1105 PM CDT Thu Aug 28 2014

The GFS model appears overdone with its precipitation forecast
late tonight and will keep tafs dry. There may be a little fog
late tonight/early Friday morning, mainly in the St Louis metro
area, and especially where there was recent rainfall early this
evening. The MOS guidance does not have as low of vsbys as it has
forecast the past few nights. It appears that the surface wind in
UIN and COU will be a little stronger than the previous couple of
nights. Sely surface wind late tonight will become sly on Friday
with scattered storms expected again during the late afternoon and
evening hours due to unstable conditions ahead of an approaching
upper level disturbance.

Specifics for KSTL: A light sely surface wind late tonight will
become sly on Friday and increase to 9-11 kts in the afternoon.
Scattered diurnal cumulus clouds should develop late Friday
morning and afternoon with scattered storms in the late afternoon
and evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     75  90  73  86 /  20  20  60  60
Quincy          72  86  69  84 /  30  40  60  40
Columbia        70  87  69  87 /  20  40  60  40
Jefferson City  71  88  70  87 /  20  40  60  40
Salem           73  88  72  84 /  20  20  50  60
Farmington      70  88  70  85 /  20  20  60  60

&&

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

$$

WFO LSX







000
FXUS63 KLSX 290423
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1123 PM CDT Thu Aug 28 2014

.SHORT TERM: (Tonight - Saturday)
Issued at 400 PM CDT Thu Aug 28 2014

Expect that convection from this afternoon will bleed over into
this evening before dissipating much like Wednesday night. Models
are redeveloping some nocturnal convection ahead of the trof in
the Plains to varying degrees, with the most bullish being the GFS
after midnight. The GFS cranks out .75 inch along and east of the
Mississippi river from St. Louis north. While I cannot totally
rule out overnight convection, the low level jet is pretty weak
and most of the isentropic lift will be well north of the area.
Have largely discounted the GFS for these reasons and only kept
slight chance/isolated PoPs overnight primarily for
northeast/northern zones.

Timing issues remain the primary problem for the approaching trof
Friday through Saturday.  Still thinking some scattered
thunderstorms will be possible Friday afternoon ahead of the trof;
but overall the models came in a bit faster with the eastward
progression.  Have sped up the introduction of likely PoPs Friday
night, and ended the likely PoPs sooner on Saturday.  Still holding
onto a chance/slight chance PoPs Saturday night as warm advection
aloft is forecast to begin again ahead of the next trof.  Seasonably
warm temperatures remain in the forecast through Saturday, though
highs will be very dependent on convection, especially on Saturday
afternoon.

Carney

.LONG TERM: (Sunday - Thursday)
Issued at 400 PM CDT Thu Aug 28 2014

Sunday should be drier than Saturday as the area will be stuck
between trofs with weak ridging overhead.  Can`t rule out scattered
afternoon storms over the southeast Missouri and southern Illinois.
The next trof in line is still forecast to move into the Midwest on
Monday.  There seems to be a little less agreement in the medium
range models on how far the south the associated cold front will
get.  Between the ECMWF and the GFS, the EC is further south with
the cold front, stalling it out near or just south of the I-70
corridor while the GFS keeps it further north near a line from St.
Joseph to Kirksville to Quincy.  Regardless, it looks like another
good chance for rain for parts of the area...primarily along and
north of the I-70 corridor Sunday night through Monday night or even
Tuesday.  The front will move back to the north Tuesday night and
Wednesday, but the GFS develops another round of convection Tuesday
night which pushes the effective front south into Arkansas
Wednesday.  This looks much less likely to me than the ECMWF
solution which simply pushes the front back to the north and allows
the heat to build back across the area.  Stuck pretty close to the
initial model blend for weather and temperatures Wednesday and
Thursday which keep highs in the mid to upper 80s, but this may be
too cool.  Will monitor trends and adjust over the next couple of
days as the models hopefully get a better handle on next week.

Carney

&&

.AVIATION:  (For the 06z TAFs through 06z Friday Night)
Issued at 1105 PM CDT Thu Aug 28 2014

The GFS model appears overdone with its precipitation forecast
late tonight and will keep tafs dry. There may be a little fog
late tonight/early Friday morning, mainly in the St Louis metro
area, and especially where there was recent rainfall early this
evening. The MOS guidance does not have as low of vsbys as it has
forecast the past few nights. It appears that the surface wind in
UIN and COU will be a little stronger than the previous couple of
nights. Sely surface wind late tonight will become sly on Friday
with scattered storms expected again during the late afternoon and
evening hours due to unstable conditions ahead of an approaching
upper level disturbance.

Specifics for KSTL: A light sely surface wind late tonight will
become sly on Friday and increase to 9-11 kts in the afternoon.
Scattered diurnal cumulus clouds should develop late Friday
morning and afternoon with scattered storms in the late afternoon
and evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     75  90  73  86 /  20  20  60  60
Quincy          72  86  69  84 /  30  40  60  40
Columbia        70  87  69  87 /  20  40  60  40
Jefferson City  71  88  70  87 /  20  40  60  40
Salem           73  88  72  84 /  20  20  50  60
Farmington      70  88  70  85 /  20  20  60  60

&&

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

$$

WFO LSX








000
FXUS63 KLSX 282307
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
607 PM CDT Thu Aug 28 2014

.SHORT TERM: (Tonight - Saturday)
Issued at 400 PM CDT Thu Aug 28 2014

Expect that convection from this afternoon will bleed over into
this evening before dissipating much like Wednesday night. Models
are redeveloping some nocturnal convection ahead of the trof in
the Plains to varying degrees, with the most bullish being the GFS
after midnight. The GFS cranks out .75 inch along and east of the
Mississippi river from St. Louis north. While I cannot totally
rule out overnight convection, the low level jet is pretty weak
and most of the isentropic lift will be well north of the area.
Have largely discounted the GFS for these reasons and only kept
slight chance/isolated PoPs overnight primarily for
northeast/northern zones.

Timing issues remain the primary problem for the approaching trof
Friday through Saturday.  Still thinking some scattered
thunderstorms will be possible Friday afternoon ahead of the trof;
but overall the models came in a bit faster with the eastward
progression.  Have sped up the introduction of likely PoPs Friday
night, and ended the likely PoPs sooner on Saturday.  Still holding
onto a chance/slight chance PoPs Saturday night as warm advection
aloft is forecast to begin again ahead of the next trof.  Seasonably
warm temperatures remain in the forecast through Saturday, though
highs will be very dependent on convection, especially on Saturday
afternoon.

Carney

.LONG TERM: (Sunday - Thursday)
Issued at 400 PM CDT Thu Aug 28 2014

Sunday should be drier than Saturday as the area will be stuck
between trofs with weak ridging overhead.  Can`t rule out scattered
afternoon storms over the southeast Missouri and southern Illinois.
The next trof in line is still forecast to move into the Midwest on
Monday.  There seems to be a little less agreement in the medium
range models on how far the south the associated cold front will
get.  Between the ECMWF and the GFS, the EC is further south with
the cold front, stalling it out near or just south of the I-70
corridor while the GFS keeps it further north near a line from St.
Joseph to Kirksville to Quincy.  Regardless, it looks like another
good chance for rain for parts of the area...primarily along and
north of the I-70 corridor Sunday night through Monday night or even
Tuesday.  The front will move back to the north Tuesday night and
Wednesday, but the GFS develops another round of convection Tuesday
night which pushes the effective front south into Arkansas
Wednesday.  This looks much less likely to me than the ECMWF
solution which simply pushes the front back to the north and allows
the heat to build back across the area.  Stuck pretty close to the
initial model blend for weather and temperatures Wednesday and
Thursday which keep highs in the mid to upper 80s, but this may be
too cool.  Will monitor trends and adjust over the next couple of
days as the models hopefully get a better handle on next week.

Carney

&&

.AVIATION:  (For the 00z TAFs through 00z Friday Evening)
Issued at 542 PM CDT Thu Aug 28 2014

Scattered storms may continue to impact UIN and the St Louis
metro area until 01-02Z this evening. The GFS model appears
overdone with its precipitation forecast late tonight and will
keep tafs dry later this evening and overnight. There may be a
little fog late tonight/early Friday morning especially where
there is rainfall early this evening, although the MOS guidance
does not have as low of vsbys as it has forecast the past few
nights. It appears that the surface wind in UIN and COU will be a
little stronger than the previous couple of nights. Sely surface
wind tonight will become sly on Friday with scattered storms expected
again during the late afternoon and evening hours with unstable
conditions ahead of an approaching upper level disturbance.

Specifics for KSTL: The storms have just pushed north of STL, but
cannot rule out a few more storms until about 02Z this evening. A
light sely surface wind tonight will become sly on Friday and
increase to 8-10 kts in the afternoon. Scattered diurnal cumulus
clouds should develop late Friday morning and afternoon with
scattered storms in the late afternoon and evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     75  90  73  86 /  40  20  60  60
Quincy          72  86  69  84 /  40  40  60  40
Columbia        70  87  69  87 /  20  40  60  40
Jefferson City  71  88  70  87 /  20  40  60  40
Salem           73  88  72  84 /  40  20  50  60
Farmington      70  88  70  85 /  20  20  60  60

&&

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

$$

WFO LSX








000
FXUS63 KLSX 282307
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
607 PM CDT Thu Aug 28 2014

.SHORT TERM: (Tonight - Saturday)
Issued at 400 PM CDT Thu Aug 28 2014

Expect that convection from this afternoon will bleed over into
this evening before dissipating much like Wednesday night. Models
are redeveloping some nocturnal convection ahead of the trof in
the Plains to varying degrees, with the most bullish being the GFS
after midnight. The GFS cranks out .75 inch along and east of the
Mississippi river from St. Louis north. While I cannot totally
rule out overnight convection, the low level jet is pretty weak
and most of the isentropic lift will be well north of the area.
Have largely discounted the GFS for these reasons and only kept
slight chance/isolated PoPs overnight primarily for
northeast/northern zones.

Timing issues remain the primary problem for the approaching trof
Friday through Saturday.  Still thinking some scattered
thunderstorms will be possible Friday afternoon ahead of the trof;
but overall the models came in a bit faster with the eastward
progression.  Have sped up the introduction of likely PoPs Friday
night, and ended the likely PoPs sooner on Saturday.  Still holding
onto a chance/slight chance PoPs Saturday night as warm advection
aloft is forecast to begin again ahead of the next trof.  Seasonably
warm temperatures remain in the forecast through Saturday, though
highs will be very dependent on convection, especially on Saturday
afternoon.

Carney

.LONG TERM: (Sunday - Thursday)
Issued at 400 PM CDT Thu Aug 28 2014

Sunday should be drier than Saturday as the area will be stuck
between trofs with weak ridging overhead.  Can`t rule out scattered
afternoon storms over the southeast Missouri and southern Illinois.
The next trof in line is still forecast to move into the Midwest on
Monday.  There seems to be a little less agreement in the medium
range models on how far the south the associated cold front will
get.  Between the ECMWF and the GFS, the EC is further south with
the cold front, stalling it out near or just south of the I-70
corridor while the GFS keeps it further north near a line from St.
Joseph to Kirksville to Quincy.  Regardless, it looks like another
good chance for rain for parts of the area...primarily along and
north of the I-70 corridor Sunday night through Monday night or even
Tuesday.  The front will move back to the north Tuesday night and
Wednesday, but the GFS develops another round of convection Tuesday
night which pushes the effective front south into Arkansas
Wednesday.  This looks much less likely to me than the ECMWF
solution which simply pushes the front back to the north and allows
the heat to build back across the area.  Stuck pretty close to the
initial model blend for weather and temperatures Wednesday and
Thursday which keep highs in the mid to upper 80s, but this may be
too cool.  Will monitor trends and adjust over the next couple of
days as the models hopefully get a better handle on next week.

Carney

&&

.AVIATION:  (For the 00z TAFs through 00z Friday Evening)
Issued at 542 PM CDT Thu Aug 28 2014

Scattered storms may continue to impact UIN and the St Louis
metro area until 01-02Z this evening. The GFS model appears
overdone with its precipitation forecast late tonight and will
keep tafs dry later this evening and overnight. There may be a
little fog late tonight/early Friday morning especially where
there is rainfall early this evening, although the MOS guidance
does not have as low of vsbys as it has forecast the past few
nights. It appears that the surface wind in UIN and COU will be a
little stronger than the previous couple of nights. Sely surface
wind tonight will become sly on Friday with scattered storms expected
again during the late afternoon and evening hours with unstable
conditions ahead of an approaching upper level disturbance.

Specifics for KSTL: The storms have just pushed north of STL, but
cannot rule out a few more storms until about 02Z this evening. A
light sely surface wind tonight will become sly on Friday and
increase to 8-10 kts in the afternoon. Scattered diurnal cumulus
clouds should develop late Friday morning and afternoon with
scattered storms in the late afternoon and evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     75  90  73  86 /  40  20  60  60
Quincy          72  86  69  84 /  40  40  60  40
Columbia        70  87  69  87 /  20  40  60  40
Jefferson City  71  88  70  87 /  20  40  60  40
Salem           73  88  72  84 /  40  20  50  60
Farmington      70  88  70  85 /  20  20  60  60

&&

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

$$

WFO LSX







000
FXUS63 KLSX 282102
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
402 PM CDT Thu Aug 28 2014

.SHORT TERM: (Tonight - Saturday)
Issued at 400 PM CDT Thu Aug 28 2014

Expect that convection from this afternoon will bleed over into
this evening before dissipating much like Wednesday night. Models
are redeveloping some nocturnal convection ahead of the trof in
the Plains to varying degrees, with the most bullish being the GFS
after midnight. The GFS cranks out .75 inch along and east of the
Mississippi river from St. Louis north. While I cannot totally
rule out overnight convection, the low level jet is pretty weak
and most of the isentropic lift will be well north of the area.
Have largely discounted the GFS for these reasons and only kept
slight chance/isolated PoPs overnight primarily for
northeast/northern zones.

Timing issues remain the primary problem for the approaching trof
Friday through Saturday.  Still thinking some scattered
thunderstorms will be possible Friday afternoon ahead of the trof;
but overall the models came in a bit faster with the eastward
progression.  Have sped up the introduction of likely PoPs Friday
night, and ended the likely PoPs sooner on Saturday.  Still holding
onto a chance/slight chance PoPs Saturday night as warm advection
aloft is forecast to begin again ahead of the next trof.  Seasonably
warm temperatures remain in the forecast through Saturday, though
highs will be very dependent on convection, especially on Saturday
afternoon.

Carney

.LONG TERM: (Sunday - Thursday)
Issued at 400 PM CDT Thu Aug 28 2014

Sunday should be drier than Saturday as the area will be stuck
between trofs with weak ridging overhead.  Can`t rule out scattered
afternoon storms over the southeast Missouri and southern Illinois.
The next trof in line is still forecast to move into the Midwest on
Monday.  There seems to be a little less agreement in the medium
range models on how far the south the associated cold front will
get.  Between the ECMWF and the GFS, the EC is further south with
the cold front, stalling it out near or just south of the I-70
corridor while the GFS keeps it further north near a line from St.
Joseph to Kirksville to Quincy.  Regardless, it looks like another
good chance for rain for parts of the area...primarily along and
north of the I-70 corridor Sunday night through Monday night or even
Tuesday.  The front will move back to the north Tuesday night and
Wednesday, but the GFS develops another round of convection Tuesday
night which pushes the effective front south into Arkansas
Wednesday.  This looks much less likely to me than the ECMWF
solution which simply pushes the front back to the north and allows
the heat to build back across the area.  Stuck pretty close to the
initial model blend for weather and temperatures Wednesday and
Thursday which keep highs in the mid to upper 80s, but this may be
too cool.  Will monitor trends and adjust over the next couple of
days as the models hopefully get a better handle on next week.

Carney

&&

.AVIATION:  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1230 PM CDT Thu Aug 28 2014

Main focus for the valid TAF period will be on convection. Diurnal
thunderstorms are likely to develop by mid afternoon with the best
chance of affecting the St. Louis metro terminals. Kept a VCTS for
now at KUIN...though beginning to have doubts about coverage of
storms that far north as instability is mainly confined to areas
to the south. Tonight should be mainly dry...as diurnal convection
weakens and dissipates by 0100-0300 UTC. Some models are
developing more showers and storms along and east of the
Mississippi River tonight but left mention out of TAFs for now due
to low confidence. During the day tomorrow looks like a better
chance for showers and storms to redevelop as a midlevel system
approaches form the west.

Specifics for KSTL:

Main focus for the valid TAF period will be on convection. Diurnal
thunderstorms are likely to develop by mid afternoon. Tonight
should be mainly dry...as diurnal convection weakens and
dissipates by 0100-0300 UTC. However...some models are initiating more
showers and storms along and east of the Mississippi River tonight
but left mention out of TAF for now due to low confidence. During
the day tomorrow looks like a better chance for showers and storms
to redevelop as a midlevel system approaches form the west so
added a VCTS mention for that possible activity.

Gosselin

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     75  90  73  86 /  40  20  60  60
Quincy          72  86  69  84 /  40  40  60  40
Columbia        70  87  69  87 /  20  40  60  40
Jefferson City  71  88  70  87 /  20  40  60  40
Salem           73  88  72  84 /  40  20  50  60
Farmington      70  88  70  85 /  20  20  60  60

&&

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

$$

WFO LSX







000
FXUS63 KLSX 282102
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
402 PM CDT Thu Aug 28 2014

.SHORT TERM: (Tonight - Saturday)
Issued at 400 PM CDT Thu Aug 28 2014

Expect that convection from this afternoon will bleed over into
this evening before dissipating much like Wednesday night. Models
are redeveloping some nocturnal convection ahead of the trof in
the Plains to varying degrees, with the most bullish being the GFS
after midnight. The GFS cranks out .75 inch along and east of the
Mississippi river from St. Louis north. While I cannot totally
rule out overnight convection, the low level jet is pretty weak
and most of the isentropic lift will be well north of the area.
Have largely discounted the GFS for these reasons and only kept
slight chance/isolated PoPs overnight primarily for
northeast/northern zones.

Timing issues remain the primary problem for the approaching trof
Friday through Saturday.  Still thinking some scattered
thunderstorms will be possible Friday afternoon ahead of the trof;
but overall the models came in a bit faster with the eastward
progression.  Have sped up the introduction of likely PoPs Friday
night, and ended the likely PoPs sooner on Saturday.  Still holding
onto a chance/slight chance PoPs Saturday night as warm advection
aloft is forecast to begin again ahead of the next trof.  Seasonably
warm temperatures remain in the forecast through Saturday, though
highs will be very dependent on convection, especially on Saturday
afternoon.

Carney

.LONG TERM: (Sunday - Thursday)
Issued at 400 PM CDT Thu Aug 28 2014

Sunday should be drier than Saturday as the area will be stuck
between trofs with weak ridging overhead.  Can`t rule out scattered
afternoon storms over the southeast Missouri and southern Illinois.
The next trof in line is still forecast to move into the Midwest on
Monday.  There seems to be a little less agreement in the medium
range models on how far the south the associated cold front will
get.  Between the ECMWF and the GFS, the EC is further south with
the cold front, stalling it out near or just south of the I-70
corridor while the GFS keeps it further north near a line from St.
Joseph to Kirksville to Quincy.  Regardless, it looks like another
good chance for rain for parts of the area...primarily along and
north of the I-70 corridor Sunday night through Monday night or even
Tuesday.  The front will move back to the north Tuesday night and
Wednesday, but the GFS develops another round of convection Tuesday
night which pushes the effective front south into Arkansas
Wednesday.  This looks much less likely to me than the ECMWF
solution which simply pushes the front back to the north and allows
the heat to build back across the area.  Stuck pretty close to the
initial model blend for weather and temperatures Wednesday and
Thursday which keep highs in the mid to upper 80s, but this may be
too cool.  Will monitor trends and adjust over the next couple of
days as the models hopefully get a better handle on next week.

Carney

&&

.AVIATION:  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1230 PM CDT Thu Aug 28 2014

Main focus for the valid TAF period will be on convection. Diurnal
thunderstorms are likely to develop by mid afternoon with the best
chance of affecting the St. Louis metro terminals. Kept a VCTS for
now at KUIN...though beginning to have doubts about coverage of
storms that far north as instability is mainly confined to areas
to the south. Tonight should be mainly dry...as diurnal convection
weakens and dissipates by 0100-0300 UTC. Some models are
developing more showers and storms along and east of the
Mississippi River tonight but left mention out of TAFs for now due
to low confidence. During the day tomorrow looks like a better
chance for showers and storms to redevelop as a midlevel system
approaches form the west.

Specifics for KSTL:

Main focus for the valid TAF period will be on convection. Diurnal
thunderstorms are likely to develop by mid afternoon. Tonight
should be mainly dry...as diurnal convection weakens and
dissipates by 0100-0300 UTC. However...some models are initiating more
showers and storms along and east of the Mississippi River tonight
but left mention out of TAF for now due to low confidence. During
the day tomorrow looks like a better chance for showers and storms
to redevelop as a midlevel system approaches form the west so
added a VCTS mention for that possible activity.

Gosselin

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     75  90  73  86 /  40  20  60  60
Quincy          72  86  69  84 /  40  40  60  40
Columbia        70  87  69  87 /  20  40  60  40
Jefferson City  71  88  70  87 /  20  40  60  40
Salem           73  88  72  84 /  40  20  50  60
Farmington      70  88  70  85 /  20  20  60  60

&&

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

$$

WFO LSX








000
FXUS63 KLSX 281741
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
1241 PM CDT Thu Aug 28 2014

.UPDATE:
Issued at 1230 PM CDT Thu Aug 28 2014

Have made some minor adjustments to going forecast into this
afternoon...mainly delaying the onset of PoPs across northeastern
Missouri and west-central Illinois. Beginning to have some doubts
as to what coverage of storms up that way may actually be...as
instability per latest SPC mesoanalysis is mainly to the south.
Will hold off and maintain mid chance PoPs up across the far north
for now but may need to lower later today. Further to the
south...scattered diurnal thunderstorms beginning mid-afternoon
looks on track as diurnal cu is already forming across
southeastern Missouri.

Gosselin

&&

.SHORT TERM:  (Through Late This Afternoon)
Issued at 334 AM CDT Thu Aug 28 2014

Nocturnal convection has remained well northwest of forecast area
with just a few very small showers popping up over northeast
Missouri and west central Illinois early this morning. For today,
will see a lot of sunshine initially but diurnal cu to pop by mid
to late morning most locations. So depending on how much cloud
cover forms and timing of when storms will develop will affect how
warm temperatures get. For now have highs in the mid 80s far north
to the upper 80s to low 90s elsewhere. Will still see dewpts in
the low to mid 70s so another very humid day. Heat indices could
get close to 100 in the metro area this afternoon but not warrant
any headlines. Just like yesterday, expect widely scattered
thunderstorms to develop along weak boundary that remains draped
across region.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 334 AM CDT Thu Aug 28 2014

Tonight activity to slowly dissipate then refocus back to the
northwest along main frontal boundary. Lows tonight will be in the
low 70s. On Friday, upper level shortwave/trof to begin to lift
northeast out of central plains and into forecast area.
Precipitation chances to be on the increase with the best chances
Friday night and Saturday. Kept likely pops going through this
period. Highs on Friday will be a bit lower, in the upper 80s and
lows Friday night will be in the upper 60s to low 70s. As system
slides through on Saturday, the combination of clouds and storms
will keep highs in the low 80s far north to the upper 80s south.

Frontal boundary to stall out just southeast of forecast area
Saturday night through Sunday, could see a bit of a break in
activity with just isolated/scattered storms through this period.
Then an even stronger trof will slide east through region Sunday
night and Monday with increasing chances of storms once again. This
boundary to stall out just south of us as well, so kept mention of
storms possible through the rest of the forecast period. Highs will
be in the 80s through the middle of next week.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1230 PM CDT Thu Aug 28 2014

Main focus for the valid TAF period will be on convection. Diurnal
thunderstorms are likely to develop by mid afternoon with the best
chance of affecting the St. Louis metro terminals. Kept a VCTS for
now at KUIN...though beginning to have doubts about coverage of
storms that far north as instability is mainly confined to areas
to the south. Tonight should be mainly dry...as diurnal convection
weakens and dissipates by 0100-0300 UTC. Some models are
developing more showers and storms along and east of the
Mississippi River tonight but left mention out of TAFs for now due
to low confidence. During the day tomorrow looks like a better
chance for showers and storms to redevelop as a midlevel system
approaches form the west.

Specifics for KSTL:

Main focus for the valid TAF period will be on convection. Diurnal
thunderstorms are likely to develop by mid afternoon. Tonight
should be mainly dry...as diurnal convection weakens and
dissipates by 0100-0300 UTC. However...some models are initiating more
showers and storms along and east of the Mississippi River tonight
but left mention out of TAF for now due to low confidence. During
the day tomorrow looks like a better chance for showers and storms
to redevelop as a midlevel system approaches form the west so
added a VCTS mention for that possible activity.

Gosselin

&&

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

$$

WFO LSX








000
FXUS63 KLSX 281136
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
636 AM CDT Thu Aug 28 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 334 AM CDT Thu Aug 28 2014

Nocturnal convection has remained well northwest of forecast area
with just a few very small showers popping up over northeast
Missouri and west central Illinois early this morning. For today,
will see a lot of sunshine initially but diurnal cu to pop by mid
to late morning most locations. So depending on how much cloud
cover forms and timing of when storms will develop will affect how
warm temperatures get. For now have highs in the mid 80s far north
to the upper 80s to low 90s elsewhere. Will still see dewpts in
the low to mid 70s so another very humid day. Heat indices could
get close to 100 in the metro area this afternoon but not warrant
any headlines. Just like yesterday, expect widely scattered
thunderstorms to develop along weak boundary that remains draped
across region.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 334 AM CDT Thu Aug 28 2014

Tonight activity to slowly dissipate then refocus back to the
northwest along main frontal boundary. Lows tonight will be in the
low 70s. On Friday, upper level shortwave/trof to begin to lift
northeast out of central plains and into forecast area.
Precipitation chances to be on the increase with the best chances
Friday night and Saturday. Kept likely pops going through this
period. Highs on Friday will be a bit lower, in the upper 80s and
lows Friday night will be in the upper 60s to low 70s. As system
slides through on Saturday, the combination of clouds and storms
will keep highs in the low 80s far north to the upper 80s south.

Frontal boundary to stall out just southeast of forecast area
Saturday night through Sunday, could see a bit of a break in
activity with just isolated/scattered storms through this period.
Then an even stronger trof will slide east through region Sunday
night and Monday with increasing chances of storms once again. This
boundary to stall out just south of us as well, so kept mention of
storms possible through the rest of the forecast period. Highs will
be in the 80s through the middle of next week.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Friday Morning)
Issued at 613 AM CDT Thu Aug 28 2014

MVFR fog will burn off this morning with scattered thunderstorms
expected to develop during the afternoon. Light east/southeast
wind.

Specifics for KSTL:
MVFR fog will burn off this morning with scattered thunderstorms
expected to impact the terminal this afternoon and early this
evening. Light east/southeast wind will continue.

CVKING

&&

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

$$

WFO LSX







000
FXUS63 KLSX 281136
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
636 AM CDT Thu Aug 28 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 334 AM CDT Thu Aug 28 2014

Nocturnal convection has remained well northwest of forecast area
with just a few very small showers popping up over northeast
Missouri and west central Illinois early this morning. For today,
will see a lot of sunshine initially but diurnal cu to pop by mid
to late morning most locations. So depending on how much cloud
cover forms and timing of when storms will develop will affect how
warm temperatures get. For now have highs in the mid 80s far north
to the upper 80s to low 90s elsewhere. Will still see dewpts in
the low to mid 70s so another very humid day. Heat indices could
get close to 100 in the metro area this afternoon but not warrant
any headlines. Just like yesterday, expect widely scattered
thunderstorms to develop along weak boundary that remains draped
across region.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 334 AM CDT Thu Aug 28 2014

Tonight activity to slowly dissipate then refocus back to the
northwest along main frontal boundary. Lows tonight will be in the
low 70s. On Friday, upper level shortwave/trof to begin to lift
northeast out of central plains and into forecast area.
Precipitation chances to be on the increase with the best chances
Friday night and Saturday. Kept likely pops going through this
period. Highs on Friday will be a bit lower, in the upper 80s and
lows Friday night will be in the upper 60s to low 70s. As system
slides through on Saturday, the combination of clouds and storms
will keep highs in the low 80s far north to the upper 80s south.

Frontal boundary to stall out just southeast of forecast area
Saturday night through Sunday, could see a bit of a break in
activity with just isolated/scattered storms through this period.
Then an even stronger trof will slide east through region Sunday
night and Monday with increasing chances of storms once again. This
boundary to stall out just south of us as well, so kept mention of
storms possible through the rest of the forecast period. Highs will
be in the 80s through the middle of next week.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Friday Morning)
Issued at 613 AM CDT Thu Aug 28 2014

MVFR fog will burn off this morning with scattered thunderstorms
expected to develop during the afternoon. Light east/southeast
wind.

Specifics for KSTL:
MVFR fog will burn off this morning with scattered thunderstorms
expected to impact the terminal this afternoon and early this
evening. Light east/southeast wind will continue.

CVKING

&&

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

$$

WFO LSX








000
FXUS63 KLSX 280838
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
338 AM CDT Thu Aug 28 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 334 AM CDT Thu Aug 28 2014

Nocturnal convection has remained well northwest of forecast area
with just a few very small showers popping up over northeast
Missouri and west central Illinois early this morning. For today,
will see a lot of sunshine initially but diurnal cu to pop by mid
to late morning most locations. So depending on how much cloud
cover forms and timing of when storms will develop will affect how
warm temperatures get. For now have highs in the mid 80s far north
to the upper 80s to low 90s elsewhere. Will still see dewpts in
the low to mid 70s so another very humid day. Heat indices could
get close to 100 in the metro area this afternoon but not warrant
any headlines. Just like yesterday, expect widely scattered
thunderstorms to develop along weak boundary that remains draped
across region.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 334 AM CDT Thu Aug 28 2014

Tonight activity to slowly dissipate then refocus back to the
northwest along main frontal boundary. Lows tonight will be in the
low 70s. On Friday, upper level shortwave/trof to begin to lift
northeast out of central plains and into forecast area.
Precipitation chances to be on the increase with the best chances
Friday night and Saturday. Kept likely pops going through this
period. Highs on Friday will be a bit lower, in the upper 80s and
lows Friday night will be in the upper 60s to low 70s. As system
slides through on Saturday, the combination of clouds and storms
will keep highs in the low 80s far north to the upper 80s south.

Frontal boundary to stall out just southeast of forecast area
Saturday night through Sunday, could see a bit of a break in
activity with just isolated/scattered storms through this period.
Then an even stronger trof will slide east through region Sunday
night and Monday with increasing chances of storms once again. This
boundary to stall out just south of us as well, so kept mention of
storms possible through the rest of the forecast period. Highs will
be in the 80s through the middle of next week.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1045 PM CDT Wed Aug 27 2014

Just mid-high level clouds for the remainder of the night with
most of the nocturnal convection remaining north of the taf sites,
although there may be a few storms impacting the UIN area towards
morning. There will likely be some fog late tonight/early Thursday
morning in COU and the St Louis metro area with light surface
winds and high surface dew points, particularly in areas which had
recent rainfall. Surface winds will pick up from a sely direction
on Thursday as the surface ridge centered over the Great Lakes
region shifts slowly eastward. Scattered diurnal cumulus clouds
will develop again late Thursday morning and afternoon along with
at least isolated afternoon and early evening thunderstorms.

Specifics for KSTL: The light lingering rain should dissipate by
06z Thursday. Mainly just mid-high level clouds for the remainder
of the night with fog possible late tonight/early Thursday
morning. The surface wind will diminish and become light late
tonight, then pick up to around 8 kts Thursday afternoon from a
sely direction. There will likely be isolated to scattered
thunderstorms Thursday afternoon into the early evening.

GKS
&&

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

$$
WFO LSX








000
FXUS63 KLSX 280838
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
338 AM CDT Thu Aug 28 2014

.SHORT TERM:  (Through Late This Afternoon)
Issued at 334 AM CDT Thu Aug 28 2014

Nocturnal convection has remained well northwest of forecast area
with just a few very small showers popping up over northeast
Missouri and west central Illinois early this morning. For today,
will see a lot of sunshine initially but diurnal cu to pop by mid
to late morning most locations. So depending on how much cloud
cover forms and timing of when storms will develop will affect how
warm temperatures get. For now have highs in the mid 80s far north
to the upper 80s to low 90s elsewhere. Will still see dewpts in
the low to mid 70s so another very humid day. Heat indices could
get close to 100 in the metro area this afternoon but not warrant
any headlines. Just like yesterday, expect widely scattered
thunderstorms to develop along weak boundary that remains draped
across region.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 334 AM CDT Thu Aug 28 2014

Tonight activity to slowly dissipate then refocus back to the
northwest along main frontal boundary. Lows tonight will be in the
low 70s. On Friday, upper level shortwave/trof to begin to lift
northeast out of central plains and into forecast area.
Precipitation chances to be on the increase with the best chances
Friday night and Saturday. Kept likely pops going through this
period. Highs on Friday will be a bit lower, in the upper 80s and
lows Friday night will be in the upper 60s to low 70s. As system
slides through on Saturday, the combination of clouds and storms
will keep highs in the low 80s far north to the upper 80s south.

Frontal boundary to stall out just southeast of forecast area
Saturday night through Sunday, could see a bit of a break in
activity with just isolated/scattered storms through this period.
Then an even stronger trof will slide east through region Sunday
night and Monday with increasing chances of storms once again. This
boundary to stall out just south of us as well, so kept mention of
storms possible through the rest of the forecast period. Highs will
be in the 80s through the middle of next week.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1045 PM CDT Wed Aug 27 2014

Just mid-high level clouds for the remainder of the night with
most of the nocturnal convection remaining north of the taf sites,
although there may be a few storms impacting the UIN area towards
morning. There will likely be some fog late tonight/early Thursday
morning in COU and the St Louis metro area with light surface
winds and high surface dew points, particularly in areas which had
recent rainfall. Surface winds will pick up from a sely direction
on Thursday as the surface ridge centered over the Great Lakes
region shifts slowly eastward. Scattered diurnal cumulus clouds
will develop again late Thursday morning and afternoon along with
at least isolated afternoon and early evening thunderstorms.

Specifics for KSTL: The light lingering rain should dissipate by
06z Thursday. Mainly just mid-high level clouds for the remainder
of the night with fog possible late tonight/early Thursday
morning. The surface wind will diminish and become light late
tonight, then pick up to around 8 kts Thursday afternoon from a
sely direction. There will likely be isolated to scattered
thunderstorms Thursday afternoon into the early evening.

GKS
&&

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

$$
WFO LSX







000
FXUS63 KLSX 280348
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1048 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 344 PM CDT Wed Aug 27 2014

Area of showers and thunderstorms over northern Missouri has almost
totally dissipated as of 20z, and convection has refocused to to the
south and east along the outflow boundary produced this morning by
convection over northern Missouri, as well as the very ill-defined
remains of the surface frontal boundary.  Storm coverage should
remain scattered due to upper level ridging over the area, but
continue to monitor the stronger storms for an isolated/pulse-type
severe weather threat over the next hour or two.

With no upper support, expect this largely diurnally-driven
convection to dissipate this evening with loss of heating, with
thunderstorm threat once again shifting back to our northwest
overnight.  Shortwave topping ridge and the associated low level
forcing/warm advection should lead to a a fairly large convective
complex forming over the mid Missouri River valley (northwest of our
FA) during the predawn hours.  While the bulk of this activity
should remain northwest of our forecast area, there should be some
threat of convection in northern sections of our CWA, either from
the leading edge of this activity, or perhaps from additional
convection that will attempt to form in the very weak zone of low
level warm advection in advance of the complex.

Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 344 PM CDT Wed Aug 27 2014

Nocturnal convection should be winding down during the morning, but
not before producing some thunderstorms over parts of central and
northeast Missouri.  It looks like the main area of precip will be
further west over northwest Missouri again nearest to the low level
baroclinic zone.  With lingering cloud cover and the upper level
ridge slowly breaking down, expect that temperatures will be cooler
Thursday than in recent days.  With highs ranging from the mid 80s
to around 90 instead of mid 90s, it looks like heat index values
will miss the magic 100 degree mark by 2-3 degrees in most
locations.  While still hot and humid, it should feel...less bad.
Expect widely scattered afternoon thunderstorms to help keep a lid
on temperatures as well.  Will therefore let the heat products
expire on schedule this evening.

Thursday night and Friday will be a repeat of tonight and Thursday
as a weak low level jet provides just enough lift to potentially
force some isolated to widely scattered convection. With overnight
lows in the upper 60s to mid 70s and highs Friday in the mid 80s to
around 90, we should be able to stay heat-headline free.
Additionally, the trof of low pressure currently spinning over
southwest Wyoming will be moving into the eastern Plains
Friday/Friday night which will further weaken the upper level ridge
and allow more widespread convection late Friday afternoon and
Friday night primarily over central and northeast Missouri.  The
trof will be directly over the CWFA Saturday which should continue
to produce thunderstorms and keep temperatures suppressed in the 80s.

Another stronger trof will dig into the Great Plains on Sunday.
This will keep the upper ridge at bay and continue to keep
temperatures in the 80s.  Can`t rule out a few afternoon
thunderstorms Sunday as well since the upper ridge will be well to
our east.  The trof continues eastward Sunday night and Monday which
will bring us increasing chances for rain.  medium range models are
in decent agreement regarding the cold front associated with the
trof.  It should push into the CWFA late Monday afternoon/Monday
evening and bringing the threat of more thunderstorms to the area.
Models stall the front out over southern Missouri Tuesday and then
allow it to creep back to the north Wednesday.  This won`t be a big
blast of cold air behind the front...rather just enough cool air to
bring temperatures down to near or slightly below seasonal normals.

Carney

&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1045 PM CDT Wed Aug 27 2014

Just mid-high level clouds for the remainder of the night with
most of the nocturnal convection remaining north of the taf sites,
although there may be a few storms impacting the UIN area towards
morning. There will likely be some fog late tonight/early Thursday
morning in COU and the St Louis metro area with light surface
winds and high surface dew points, particularly in areas which had
recent rainfall. Surface winds will pick up from a sely direction
on Thursday as the surface ridge centered over the Great Lakes
region shifts slowly eastward. Scattered diurnal cumulus clouds
will develop again late Thursday morning and afternoon along with
at least isolated afternoon and early evening thunderstorms.

Specifics for KSTL: The light lingering rain should dissipate by
06z Thursday. Mainly just mid-high level clouds for the remainder
of the night with fog possible late tonight/early Thursday
morning. The surface wind will diminish and become light late
tonight, then pick up to around 8 kts Thursday afternoon from a
sely direction. There will likely be isolated to scattered
thunderstorms Thursday afternoon into the early evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     72  91  76  90 /  10  40  20  20
Quincy          69  87  71  88 /  20  40  30  30
Columbia        71  92  71  88 /  10  30  20  40
Jefferson City  71  92  72  89 /  10  20  20  40
Salem           70  89  71  89 /  20  40  30  20
Farmington      70  90  70  88 /  10  20  10  20

&&

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

$$

WFO LSX








000
FXUS63 KLSX 280348
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1048 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 344 PM CDT Wed Aug 27 2014

Area of showers and thunderstorms over northern Missouri has almost
totally dissipated as of 20z, and convection has refocused to to the
south and east along the outflow boundary produced this morning by
convection over northern Missouri, as well as the very ill-defined
remains of the surface frontal boundary.  Storm coverage should
remain scattered due to upper level ridging over the area, but
continue to monitor the stronger storms for an isolated/pulse-type
severe weather threat over the next hour or two.

With no upper support, expect this largely diurnally-driven
convection to dissipate this evening with loss of heating, with
thunderstorm threat once again shifting back to our northwest
overnight.  Shortwave topping ridge and the associated low level
forcing/warm advection should lead to a a fairly large convective
complex forming over the mid Missouri River valley (northwest of our
FA) during the predawn hours.  While the bulk of this activity
should remain northwest of our forecast area, there should be some
threat of convection in northern sections of our CWA, either from
the leading edge of this activity, or perhaps from additional
convection that will attempt to form in the very weak zone of low
level warm advection in advance of the complex.

Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 344 PM CDT Wed Aug 27 2014

Nocturnal convection should be winding down during the morning, but
not before producing some thunderstorms over parts of central and
northeast Missouri.  It looks like the main area of precip will be
further west over northwest Missouri again nearest to the low level
baroclinic zone.  With lingering cloud cover and the upper level
ridge slowly breaking down, expect that temperatures will be cooler
Thursday than in recent days.  With highs ranging from the mid 80s
to around 90 instead of mid 90s, it looks like heat index values
will miss the magic 100 degree mark by 2-3 degrees in most
locations.  While still hot and humid, it should feel...less bad.
Expect widely scattered afternoon thunderstorms to help keep a lid
on temperatures as well.  Will therefore let the heat products
expire on schedule this evening.

Thursday night and Friday will be a repeat of tonight and Thursday
as a weak low level jet provides just enough lift to potentially
force some isolated to widely scattered convection. With overnight
lows in the upper 60s to mid 70s and highs Friday in the mid 80s to
around 90, we should be able to stay heat-headline free.
Additionally, the trof of low pressure currently spinning over
southwest Wyoming will be moving into the eastern Plains
Friday/Friday night which will further weaken the upper level ridge
and allow more widespread convection late Friday afternoon and
Friday night primarily over central and northeast Missouri.  The
trof will be directly over the CWFA Saturday which should continue
to produce thunderstorms and keep temperatures suppressed in the 80s.

Another stronger trof will dig into the Great Plains on Sunday.
This will keep the upper ridge at bay and continue to keep
temperatures in the 80s.  Can`t rule out a few afternoon
thunderstorms Sunday as well since the upper ridge will be well to
our east.  The trof continues eastward Sunday night and Monday which
will bring us increasing chances for rain.  medium range models are
in decent agreement regarding the cold front associated with the
trof.  It should push into the CWFA late Monday afternoon/Monday
evening and bringing the threat of more thunderstorms to the area.
Models stall the front out over southern Missouri Tuesday and then
allow it to creep back to the north Wednesday.  This won`t be a big
blast of cold air behind the front...rather just enough cool air to
bring temperatures down to near or slightly below seasonal normals.

Carney

&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1045 PM CDT Wed Aug 27 2014

Just mid-high level clouds for the remainder of the night with
most of the nocturnal convection remaining north of the taf sites,
although there may be a few storms impacting the UIN area towards
morning. There will likely be some fog late tonight/early Thursday
morning in COU and the St Louis metro area with light surface
winds and high surface dew points, particularly in areas which had
recent rainfall. Surface winds will pick up from a sely direction
on Thursday as the surface ridge centered over the Great Lakes
region shifts slowly eastward. Scattered diurnal cumulus clouds
will develop again late Thursday morning and afternoon along with
at least isolated afternoon and early evening thunderstorms.

Specifics for KSTL: The light lingering rain should dissipate by
06z Thursday. Mainly just mid-high level clouds for the remainder
of the night with fog possible late tonight/early Thursday
morning. The surface wind will diminish and become light late
tonight, then pick up to around 8 kts Thursday afternoon from a
sely direction. There will likely be isolated to scattered
thunderstorms Thursday afternoon into the early evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     72  91  76  90 /  10  40  20  20
Quincy          69  87  71  88 /  20  40  30  30
Columbia        71  92  71  88 /  10  30  20  40
Jefferson City  71  92  72  89 /  10  20  20  40
Salem           70  89  71  89 /  20  40  30  20
Farmington      70  90  70  88 /  10  20  10  20

&&

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

$$

WFO LSX







000
FXUS63 KLSX 272252
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
552 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 344 PM CDT Wed Aug 27 2014

Area of showers and thunderstorms over northern Missouri has almost
totally dissipated as of 20z, and convection has refocused to to the
south and east along the outflow boundary produced this morning by
convection over northern Missouri, as well as the very ill-defined
remains of the surface frontal boundary.  Storm coverage should
remain scattered due to upper level ridging over the area, but
continue to monitor the stronger storms for an isolated/pulse-type
severe weather threat over the next hour or two.

With no upper support, expect this largely diurnally-driven
convection to dissipate this evening with loss of heating, with
thunderstorm threat once again shifting back to our northwest
overnight.  Shortwave topping ridge and the associated low level
forcing/warm advection should lead to a a fairly large convective
complex forming over the mid Missouri River valley (northwest of our
FA) during the predawn hours.  While the bulk of this activity
should remain northwest of our forecast area, there should be some
threat of convection in northern sections of our CWA, either from
the leading edge of this activity, or perhaps from additional
convection that will attempt to form in the very weak zone of low
level warm advection in advance of the complex.

Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 344 PM CDT Wed Aug 27 2014

Nocturnal convection should be winding down during the morning, but
not before producing some thunderstorms over parts of central and
northeast Missouri.  It looks like the main area of precip will be
further west over northwest Missouri again nearest to the low level
baroclinic zone.  With lingering cloud cover and the upper level
ridge slowly breaking down, expect that temperatures will be cooler
Thursday than in recent days.  With highs ranging from the mid 80s
to around 90 instead of mid 90s, it looks like heat index values
will miss the magic 100 degree mark by 2-3 degrees in most
locations.  While still hot and humid, it should feel...less bad.
Expect widely scattered afternoon thunderstorms to help keep a lid
on temperatures as well.  Will therefore let the heat products
expire on schedule this evening.

Thursday night and Friday will be a repeat of tonight and Thursday
as a weak low level jet provides just enough lift to potentially
force some isolated to widely scattered convection. With overnight
lows in the upper 60s to mid 70s and highs Friday in the mid 80s to
around 90, we should be able to stay heat-headline free.
Additionally, the trof of low pressure currently spinning over
southwest Wyoming will be moving into the eastern Plains
Friday/Friday night which will further weaken the upper level ridge
and allow more widespread convection late Friday afternoon and
Friday night primarily over central and northeast Missouri.  The
trof will be directly over the CWFA Saturday which should continue
to produce thunderstorms and keep temperatures suppressed in the 80s.

Another stronger trof will dig into the Great Plains on Sunday.
This will keep the upper ridge at bay and continue to keep
temperatures in the 80s.  Can`t rule out a few afternoon
thunderstorms Sunday as well since the upper ridge will be well to
our east.  The trof continues eastward Sunday night and Monday which
will bring us increasing chances for rain.  medium range models are
in decent agreement regarding the cold front associated with the
trof.  It should push into the CWFA late Monday afternoon/Monday
evening and bringing the threat of more thunderstorms to the area.
Models stall the front out over southern Missouri Tuesday and then
allow it to creep back to the north Wednesday.  This won`t be a big
blast of cold air behind the front...rather just enough cool air to
bring temperatures down to near or slightly below seasonal normals.

Carney

&&

.AVIATION:  (For the 00z TAFs through 00z Thursday Evening)
Issued at 525 PM CDT Wed Aug 27 2014

Most of the convection impacting the St Louis metro area should
dissipate early this evening with the loss of daytime heating.
Mainly just mid-high level clouds for the remainder of the night
with most of the nocturnal convection remaining north of the taf
sites, although there may be a few storms impacting the UIN area
towards morning. There will likely be some fog late tonight/early
Thursday morning in COU and the St Louis metro area with light
surface winds and high surface dew points, particularly in areas
which had recent rainfall. Surface winds will pick up from a sely
direction on Thursday as the surface ridge centered over the Great
Lakes region shifts slowly eastward. Scattered diurnal cumulus
clouds will develop again late Thursday morning and afternoon
along with at least isolated afternoon and early evening
thunderstorms.

Specifics for KSTL: Thunderstorms should dissipate early this
evening, by 01z or 02z. Mainly just mid-high level clouds for the
remainder of the night with fog possible late tonight/early
Thursday morning. The surface wind will diminish and become light
later this evening, then pick up to around 8 kts Thursday
afternoon from a sely direction. There will likely be isolated to
scattered thunderstorms Thursday afternoon into the early evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     76  91  76  90 /  30  40  20  20
Quincy          69  87  71  88 /  20  50  30  30
Columbia        72  92  71  88 /  20  30  20  40
Jefferson City  72  92  72  89 /  20  20  20  40
Salem           71  89  71  89 /  30  40  30  20
Farmington      71  90  70  88 /  30  20  10  20

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX







000
FXUS63 KLSX 272252
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
552 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 344 PM CDT Wed Aug 27 2014

Area of showers and thunderstorms over northern Missouri has almost
totally dissipated as of 20z, and convection has refocused to to the
south and east along the outflow boundary produced this morning by
convection over northern Missouri, as well as the very ill-defined
remains of the surface frontal boundary.  Storm coverage should
remain scattered due to upper level ridging over the area, but
continue to monitor the stronger storms for an isolated/pulse-type
severe weather threat over the next hour or two.

With no upper support, expect this largely diurnally-driven
convection to dissipate this evening with loss of heating, with
thunderstorm threat once again shifting back to our northwest
overnight.  Shortwave topping ridge and the associated low level
forcing/warm advection should lead to a a fairly large convective
complex forming over the mid Missouri River valley (northwest of our
FA) during the predawn hours.  While the bulk of this activity
should remain northwest of our forecast area, there should be some
threat of convection in northern sections of our CWA, either from
the leading edge of this activity, or perhaps from additional
convection that will attempt to form in the very weak zone of low
level warm advection in advance of the complex.

Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 344 PM CDT Wed Aug 27 2014

Nocturnal convection should be winding down during the morning, but
not before producing some thunderstorms over parts of central and
northeast Missouri.  It looks like the main area of precip will be
further west over northwest Missouri again nearest to the low level
baroclinic zone.  With lingering cloud cover and the upper level
ridge slowly breaking down, expect that temperatures will be cooler
Thursday than in recent days.  With highs ranging from the mid 80s
to around 90 instead of mid 90s, it looks like heat index values
will miss the magic 100 degree mark by 2-3 degrees in most
locations.  While still hot and humid, it should feel...less bad.
Expect widely scattered afternoon thunderstorms to help keep a lid
on temperatures as well.  Will therefore let the heat products
expire on schedule this evening.

Thursday night and Friday will be a repeat of tonight and Thursday
as a weak low level jet provides just enough lift to potentially
force some isolated to widely scattered convection. With overnight
lows in the upper 60s to mid 70s and highs Friday in the mid 80s to
around 90, we should be able to stay heat-headline free.
Additionally, the trof of low pressure currently spinning over
southwest Wyoming will be moving into the eastern Plains
Friday/Friday night which will further weaken the upper level ridge
and allow more widespread convection late Friday afternoon and
Friday night primarily over central and northeast Missouri.  The
trof will be directly over the CWFA Saturday which should continue
to produce thunderstorms and keep temperatures suppressed in the 80s.

Another stronger trof will dig into the Great Plains on Sunday.
This will keep the upper ridge at bay and continue to keep
temperatures in the 80s.  Can`t rule out a few afternoon
thunderstorms Sunday as well since the upper ridge will be well to
our east.  The trof continues eastward Sunday night and Monday which
will bring us increasing chances for rain.  medium range models are
in decent agreement regarding the cold front associated with the
trof.  It should push into the CWFA late Monday afternoon/Monday
evening and bringing the threat of more thunderstorms to the area.
Models stall the front out over southern Missouri Tuesday and then
allow it to creep back to the north Wednesday.  This won`t be a big
blast of cold air behind the front...rather just enough cool air to
bring temperatures down to near or slightly below seasonal normals.

Carney

&&

.AVIATION:  (For the 00z TAFs through 00z Thursday Evening)
Issued at 525 PM CDT Wed Aug 27 2014

Most of the convection impacting the St Louis metro area should
dissipate early this evening with the loss of daytime heating.
Mainly just mid-high level clouds for the remainder of the night
with most of the nocturnal convection remaining north of the taf
sites, although there may be a few storms impacting the UIN area
towards morning. There will likely be some fog late tonight/early
Thursday morning in COU and the St Louis metro area with light
surface winds and high surface dew points, particularly in areas
which had recent rainfall. Surface winds will pick up from a sely
direction on Thursday as the surface ridge centered over the Great
Lakes region shifts slowly eastward. Scattered diurnal cumulus
clouds will develop again late Thursday morning and afternoon
along with at least isolated afternoon and early evening
thunderstorms.

Specifics for KSTL: Thunderstorms should dissipate early this
evening, by 01z or 02z. Mainly just mid-high level clouds for the
remainder of the night with fog possible late tonight/early
Thursday morning. The surface wind will diminish and become light
later this evening, then pick up to around 8 kts Thursday
afternoon from a sely direction. There will likely be isolated to
scattered thunderstorms Thursday afternoon into the early evening.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     76  91  76  90 /  30  40  20  20
Quincy          69  87  71  88 /  20  50  30  30
Columbia        72  92  71  88 /  20  30  20  40
Jefferson City  72  92  72  89 /  20  20  20  40
Salem           71  89  71  89 /  30  40  30  20
Farmington      71  90  70  88 /  30  20  10  20

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX








000
FXUS63 KLSX 272045
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
345 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 344 PM CDT Wed Aug 27 2014

Area of showers and thunderstorms over northern Missouri has almost
totally dissipated as of 20z, and convection has refocused to to the
south and east along the outflow boundary produced this morning by
convection over northern Missouri, as well as the very ill-defined
remains of the surface frontal boundary.  Storm coverage should
remain scattered due to upper level ridging over the area, but
continue to monitor the stronger storms for an isolated/pulse-type
severe weather threat over the next hour or two.

With no upper support, expect this largely diurnally-driven
convection to dissipate this evening with loss of heating, with
thunderstorm threat once again shifting back to our northwest
overnight.  Shortwave topping ridge and the associated low level
forcing/warm advection should lead to a a fairly large convective
complex forming over the mid Missouri River valley (northwest of our
FA) during the predawn hours.  While the bulk of this activity
should remain northwest of our forecast area, there should be some
threat of convection in northern sections of our CWA, either from
the leading edge of this activity, or perhaps from additional
convection that will attempt to form in the very weak zone of low
level warm advection in advance of the complex.

Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 344 PM CDT Wed Aug 27 2014

Nocturnal convection should be winding down during the morning, but
not before producing some thunderstorms over parts of central and
northeast Missouri.  It looks like the main area of precip will be
further west over northwest Missouri again nearest to the low level
baroclinic zone.  With lingering cloud cover and the upper level
ridge slowly breaking down, expect that temperatures will be cooler
Thursday than in recent days.  With highs ranging from the mid 80s
to around 90 instead of mid 90s, it looks like heat index values
will miss the magic 100 degree mark by 2-3 degrees in most
locations.  While still hot and humid, it should feel...less bad.
Expect widely scattered afternoon thunderstorms to help keep a lid
on temperatures as well.  Will therefore let the heat products
expire on schedule this evening.

Thursday night and Friday will be a repeat of tonight and Thursday
as a weak low level jet provides just enough lift to potentially
force some isolated to widely scattered convection. With overnight
lows in the upper 60s to mid 70s and highs Friday in the mid 80s to
around 90, we should be able to stay heat-headline free.
Additionally, the trof of low pressure currently spinning over
southwest Wyoming will be moving into the eastern Plains
Friday/Friday night which will further weaken the upper level ridge
and allow more widespread convection late Friday afternoon and
Friday night primarily over central and northeast Missouri.  The
trof will be directly over the CWFA Saturday which should continue
to produce thunderstorms and keep temperatures suppressed in the 80s.

Another stronger trof will dig into the Great Plains on Sunday.
This will keep the upper ridge at bay and continue to keep
temperatures in the 80s.  Can`t rule out a few afternoon
thunderstorms Sunday as well since the upper ridge will be well to
our east.  The trof continues eastward Sunday night and Monday which
will bring us increasing chances for rain.  medium range models are
in decent agreement regarding the cold front associated with the
trof.  It should push into the CWFA late Monday afternoon/Monday
evening and bringing the threat of more thunderstorms to the area.
Models stall the front out over southern Missouri Tuesday and then
allow it to creep back to the north Wednesday.  This won`t be a big
blast of cold air behind the front...rather just enough cool air to
bring temperatures down to near or slightly below seasonal normals.

Carney

&&

.AVIATION:  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1245 PM CDT Wed Aug 27 2014

Have gone with the idea that storms over north central MO will be
weakening this afternoon and will not impact UIN as low level jet
(finally) loses it`s punch. Meanwhile, scattered convection is
epected to develop along outflow boundary and/or the very ill-
defined remnants of synoptic frontal boundary, and the latest
surface data and hi-res output suggests this activity will be east
of COU and primarily impact STL metro sites. For now have stayed
with VCTS in the STL area TAFs, and will update if/when convective
trends become more clear. Much like yesterday, these storms will
be capable of very localized, microburst winds, and will be
monitoring radar trends for this threat as well. Have allowed the
afternoon thunderstorm threat to end by 01z, with generally
tranquil conditions during the late evening and overnight hours.
Heading towards daybreak have maintained some MVFR vsbys in fog
along the I-70 corridor in the warm humid AMS, and reintroduced
VCTS at UIN as leading edge of complex that forms to our NW
overnight should be threatening northern parts of the CWA by that
time.

Specifics for KSTL: Aviation concerns can expect scattered
TSRA to form over the Bi-State area this afternoon, but some doubt
about whether the storms will actually impact within 10nmi of the
STL aerodrome. Aviation interests should also be aware that these
storms will be capable of producing micro-burst wind, much like
affected parts of STL county yesterday afternoon. Have allowed
this threat to diminish early this evening, with generally
tranquil conditions overnight. Area has been experienced MVFR
vsbys in fog the past several mornings, and without a change in
airmass have included this in the 08-12z time frame. More ams-type
TSRA are possible again on Thursday, but have not included in TAF
attm due to the large uncertainty of where the axis of
development will be.

Truett

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     76  91  76  90 /  30  40  20  20
Quincy          69  87  71  88 /  20  50  30  30
Columbia        72  92  71  88 /  20  30  20  40
Jefferson City  72  92  72  89 /  20  20  20  40
Salem           71  89  71  89 /  30  40  30  20
Farmington      71  90  70  88 /  30  20  10  20

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX








000
FXUS63 KLSX 272045
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
345 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 344 PM CDT Wed Aug 27 2014

Area of showers and thunderstorms over northern Missouri has almost
totally dissipated as of 20z, and convection has refocused to to the
south and east along the outflow boundary produced this morning by
convection over northern Missouri, as well as the very ill-defined
remains of the surface frontal boundary.  Storm coverage should
remain scattered due to upper level ridging over the area, but
continue to monitor the stronger storms for an isolated/pulse-type
severe weather threat over the next hour or two.

With no upper support, expect this largely diurnally-driven
convection to dissipate this evening with loss of heating, with
thunderstorm threat once again shifting back to our northwest
overnight.  Shortwave topping ridge and the associated low level
forcing/warm advection should lead to a a fairly large convective
complex forming over the mid Missouri River valley (northwest of our
FA) during the predawn hours.  While the bulk of this activity
should remain northwest of our forecast area, there should be some
threat of convection in northern sections of our CWA, either from
the leading edge of this activity, or perhaps from additional
convection that will attempt to form in the very weak zone of low
level warm advection in advance of the complex.

Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 344 PM CDT Wed Aug 27 2014

Nocturnal convection should be winding down during the morning, but
not before producing some thunderstorms over parts of central and
northeast Missouri.  It looks like the main area of precip will be
further west over northwest Missouri again nearest to the low level
baroclinic zone.  With lingering cloud cover and the upper level
ridge slowly breaking down, expect that temperatures will be cooler
Thursday than in recent days.  With highs ranging from the mid 80s
to around 90 instead of mid 90s, it looks like heat index values
will miss the magic 100 degree mark by 2-3 degrees in most
locations.  While still hot and humid, it should feel...less bad.
Expect widely scattered afternoon thunderstorms to help keep a lid
on temperatures as well.  Will therefore let the heat products
expire on schedule this evening.

Thursday night and Friday will be a repeat of tonight and Thursday
as a weak low level jet provides just enough lift to potentially
force some isolated to widely scattered convection. With overnight
lows in the upper 60s to mid 70s and highs Friday in the mid 80s to
around 90, we should be able to stay heat-headline free.
Additionally, the trof of low pressure currently spinning over
southwest Wyoming will be moving into the eastern Plains
Friday/Friday night which will further weaken the upper level ridge
and allow more widespread convection late Friday afternoon and
Friday night primarily over central and northeast Missouri.  The
trof will be directly over the CWFA Saturday which should continue
to produce thunderstorms and keep temperatures suppressed in the 80s.

Another stronger trof will dig into the Great Plains on Sunday.
This will keep the upper ridge at bay and continue to keep
temperatures in the 80s.  Can`t rule out a few afternoon
thunderstorms Sunday as well since the upper ridge will be well to
our east.  The trof continues eastward Sunday night and Monday which
will bring us increasing chances for rain.  medium range models are
in decent agreement regarding the cold front associated with the
trof.  It should push into the CWFA late Monday afternoon/Monday
evening and bringing the threat of more thunderstorms to the area.
Models stall the front out over southern Missouri Tuesday and then
allow it to creep back to the north Wednesday.  This won`t be a big
blast of cold air behind the front...rather just enough cool air to
bring temperatures down to near or slightly below seasonal normals.

Carney

&&

.AVIATION:  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1245 PM CDT Wed Aug 27 2014

Have gone with the idea that storms over north central MO will be
weakening this afternoon and will not impact UIN as low level jet
(finally) loses it`s punch. Meanwhile, scattered convection is
epected to develop along outflow boundary and/or the very ill-
defined remnants of synoptic frontal boundary, and the latest
surface data and hi-res output suggests this activity will be east
of COU and primarily impact STL metro sites. For now have stayed
with VCTS in the STL area TAFs, and will update if/when convective
trends become more clear. Much like yesterday, these storms will
be capable of very localized, microburst winds, and will be
monitoring radar trends for this threat as well. Have allowed the
afternoon thunderstorm threat to end by 01z, with generally
tranquil conditions during the late evening and overnight hours.
Heading towards daybreak have maintained some MVFR vsbys in fog
along the I-70 corridor in the warm humid AMS, and reintroduced
VCTS at UIN as leading edge of complex that forms to our NW
overnight should be threatening northern parts of the CWA by that
time.

Specifics for KSTL: Aviation concerns can expect scattered
TSRA to form over the Bi-State area this afternoon, but some doubt
about whether the storms will actually impact within 10nmi of the
STL aerodrome. Aviation interests should also be aware that these
storms will be capable of producing micro-burst wind, much like
affected parts of STL county yesterday afternoon. Have allowed
this threat to diminish early this evening, with generally
tranquil conditions overnight. Area has been experienced MVFR
vsbys in fog the past several mornings, and without a change in
airmass have included this in the 08-12z time frame. More ams-type
TSRA are possible again on Thursday, but have not included in TAF
attm due to the large uncertainty of where the axis of
development will be.

Truett

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     76  91  76  90 /  30  40  20  20
Quincy          69  87  71  88 /  20  50  30  30
Columbia        72  92  71  88 /  20  30  20  40
Jefferson City  72  92  72  89 /  20  20  20  40
Salem           71  89  71  89 /  30  40  30  20
Farmington      71  90  70  88 /  30  20  10  20

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX







000
FXUS63 KLSX 271803
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
103 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 1148 AM CDT Wed Aug 27 2014

Going forecast trends still look reasonable. Ongoing activity
over northern Missouri should continue to drift east and
weaken with time as additional storms develop and become focused
along the southward pushing outflow boundary (approximately near a
KJEF-KUIN line attm) and along ill-defined remnants of synoptic
surface front, roughly from northern Ozarks, through the STL
metro, into central IL. Since there has been very little change in
the warm, humid airmass, expect that the storms that form along
the outflow and/or frontal boundary will pose a pulse-type severe
storm threat (gusty winds and some hail)...much like what occurred
yesterday.

Truett

.LONG TERM: (Thursday through Tuesday)
Issued at 237 AM CDT Wed Aug 27 2014

Boundary will be slow to lift back north on Thursday and may become
orientated more northwest to southeast across the CWA...paralleling
the Mississippi River. Once again, afternoon convection will be
possible in the vicinity of this front.

The boundary should finally lift north as a warm front Thursday
night with dry and seasonably warm weather expected on Friday
ahead of the shortwave/cold front that approaches from the west.

Have tried to focus likely POPs Friday night and Saturday with this
next system as blended guidance seems to give too long of a period
of POPs when compared to reality. So, after a wet and cooler
beginning to the Labor Day Weekend, it appears chances of
precipitation will decrease for Sunday and Monday (Labor Day), with
temperatures beginning to inch back up above normal in the wake
of this storm system.

CVKING

&&

.AVIATION:  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1245 PM CDT Wed Aug 27 2014

Have gone with the idea that storms over north central MO will be
weakening this afternoon and will not impact UIN as low level jet
(finally) loses it`s punch. Meanwhile, scattered convection is
epected to develop along outflow boundary and/or the very ill-
defined remnants of synoptic frontal boundary, and the latest
surface data and hi-res output suggests this activity will be east
of COU and primarily impact STL metro sites. For now have stayed
with VCTS in the STL area TAFs, and will update if/when convective
trends become more clear. Much like yesterday, these storms will
be capable of very localized, microburst winds, and will be
monitoring radar trends for this threat as well. Have allowed the
afternoon thunderstorm threat to end by 01z, with generally
tranquil conditions during the late evening and overnight hours.
Heading towards daybreak have maintained some MVFR vsbys in fog
along the I-70 corridor in the warm humid AMS, and reintroduced
VCTS at UIN as leading edge of complex that forms to our NW
overnight should be threatening northern parts of the CWA by that
time.

Specifics for KSTL: Aviation concerns can expect scattered
TSRA to form over the Bi-State area this afternoon, but some doubt
about whether the storms will actually impact within 10nmi of the
STL aerodrome. Aviation interests should also be aware that these
storms will be capable of producing micro-burst wind, much like
affected parts of STL county yesterday afternoon. Have allowed
this threat to diminish early this evening, with generally
tranquil conditions overnight. Area has been experienced MVFR
vsbys in fog the past several mornings, and without a change in
airmass have included this in the 08-12z time frame. More ams-type
TSRA are possible again on Thursday, but have not included in TAF
attm due to the large uncertainty of where the axis of
development will be.

Truett

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX








000
FXUS63 KLSX 271803
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
103 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 1148 AM CDT Wed Aug 27 2014

Going forecast trends still look reasonable. Ongoing activity
over northern Missouri should continue to drift east and
weaken with time as additional storms develop and become focused
along the southward pushing outflow boundary (approximately near a
KJEF-KUIN line attm) and along ill-defined remnants of synoptic
surface front, roughly from northern Ozarks, through the STL
metro, into central IL. Since there has been very little change in
the warm, humid airmass, expect that the storms that form along
the outflow and/or frontal boundary will pose a pulse-type severe
storm threat (gusty winds and some hail)...much like what occurred
yesterday.

Truett

.LONG TERM: (Thursday through Tuesday)
Issued at 237 AM CDT Wed Aug 27 2014

Boundary will be slow to lift back north on Thursday and may become
orientated more northwest to southeast across the CWA...paralleling
the Mississippi River. Once again, afternoon convection will be
possible in the vicinity of this front.

The boundary should finally lift north as a warm front Thursday
night with dry and seasonably warm weather expected on Friday
ahead of the shortwave/cold front that approaches from the west.

Have tried to focus likely POPs Friday night and Saturday with this
next system as blended guidance seems to give too long of a period
of POPs when compared to reality. So, after a wet and cooler
beginning to the Labor Day Weekend, it appears chances of
precipitation will decrease for Sunday and Monday (Labor Day), with
temperatures beginning to inch back up above normal in the wake
of this storm system.

CVKING

&&

.AVIATION:  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1245 PM CDT Wed Aug 27 2014

Have gone with the idea that storms over north central MO will be
weakening this afternoon and will not impact UIN as low level jet
(finally) loses it`s punch. Meanwhile, scattered convection is
epected to develop along outflow boundary and/or the very ill-
defined remnants of synoptic frontal boundary, and the latest
surface data and hi-res output suggests this activity will be east
of COU and primarily impact STL metro sites. For now have stayed
with VCTS in the STL area TAFs, and will update if/when convective
trends become more clear. Much like yesterday, these storms will
be capable of very localized, microburst winds, and will be
monitoring radar trends for this threat as well. Have allowed the
afternoon thunderstorm threat to end by 01z, with generally
tranquil conditions during the late evening and overnight hours.
Heading towards daybreak have maintained some MVFR vsbys in fog
along the I-70 corridor in the warm humid AMS, and reintroduced
VCTS at UIN as leading edge of complex that forms to our NW
overnight should be threatening northern parts of the CWA by that
time.

Specifics for KSTL: Aviation concerns can expect scattered
TSRA to form over the Bi-State area this afternoon, but some doubt
about whether the storms will actually impact within 10nmi of the
STL aerodrome. Aviation interests should also be aware that these
storms will be capable of producing micro-burst wind, much like
affected parts of STL county yesterday afternoon. Have allowed
this threat to diminish early this evening, with generally
tranquil conditions overnight. Area has been experienced MVFR
vsbys in fog the past several mornings, and without a change in
airmass have included this in the 08-12z time frame. More ams-type
TSRA are possible again on Thursday, but have not included in TAF
attm due to the large uncertainty of where the axis of
development will be.

Truett

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX







000
FXUS63 KLSX 271706
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
1206 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 1148 AM CDT Wed Aug 27 2014

Going forecast trends still look reasonable. Ongoing activity
over northern Missouri should continue to drift east and
weaken with time as additional storms develop and become focused
along the southward pushing outflow boundary (approximately near a
KJEF-KUIN line attm) and along ill-defined remnants of synoptic
surface front, roughly from northern Ozarks, through the STL
metro, into central IL. Since there has been very little change in
the warm, humid airmass, expect that the storms that form along
the outflow and/or frontal boundary will pose a pulse-type severe
storm threat (gusty winds and some hail)...much like what occurred
yesterday.

Truett

.LONG TERM: (Thursday through Tuesday)
Issued at 237 AM CDT Wed Aug 27 2014

Boundary will be slow to lift back north on Thursday and may become
orientated more northwest to southeast across the CWA...paralleling
the Mississippi River. Once again, afternoon convection will be
possible in the vicinity of this front.

The boundary should finally lift north as a warm front Thursday
night with dry and seasonably warm weather expected on Friday
ahead of the shortwave/cold front that approaches from the west.

Have tried to focus likely POPs Friday night and Saturday with this
next system as blended guidance seems to give too long of a period
of POPs when compared to reality. So, after a wet and cooler
beginning to the Labor Day Weekend, it appears chances of
precipitation will decrease for Sunday and Monday (Labor Day), with
temperatures beginning to inch back up above normal in the wake
of this storm system.

CVKING

&&

.AVIATION:  (For the 12z TAFs through 12z Thursday Morning)
Issued at 655 AM CDT Wed Aug 27 2014

Complex of storms continues to develop over northwestern Missouri
and track to the east. Should move into KUIN by 17z and persist
through the afternoon hours. Otherwise, trying to pin down when
storms may develop and move through other tafs sites is difficult,
so for now kept tafs dry. Light winds to pickup from the northeast
to east today as frontal boundary settles over region. Some patchy
dense fog has developed over central MO, but should lift and
dissipate by mid morning today. By tonight, front will be just
south of Interstate 70, so could see some patchy mvfr fog develop
after 06z Thursday, so added tempo mention.

Specifics for KSTL:

Complex of storms continues to develop over northwestern Missouri
and track to the east. Should move remain north of metro area.
Otherwise, trying to pin down when storms may develop and move
through metro area is difficult, so for now kept taf dry. Light
winds to pickup from the northeast to east by 18z as frontal
boundary settles over region. By tonight, front will be just
south of Interstate 70, so could see some patchy mvfr fog develop
after 08z Thursday, so added tempo mention.

Byrd

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX








000
FXUS63 KLSX 271706
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
1206 PM CDT Wed Aug 27 2014

.SHORT TERM:  (Through Late Tonight)
Issued at 1148 AM CDT Wed Aug 27 2014

Going forecast trends still look reasonable. Ongoing activity
over northern Missouri should continue to drift east and
weaken with time as additional storms develop and become focused
along the southward pushing outflow boundary (approximately near a
KJEF-KUIN line attm) and along ill-defined remnants of synoptic
surface front, roughly from northern Ozarks, through the STL
metro, into central IL. Since there has been very little change in
the warm, humid airmass, expect that the storms that form along
the outflow and/or frontal boundary will pose a pulse-type severe
storm threat (gusty winds and some hail)...much like what occurred
yesterday.

Truett

.LONG TERM: (Thursday through Tuesday)
Issued at 237 AM CDT Wed Aug 27 2014

Boundary will be slow to lift back north on Thursday and may become
orientated more northwest to southeast across the CWA...paralleling
the Mississippi River. Once again, afternoon convection will be
possible in the vicinity of this front.

The boundary should finally lift north as a warm front Thursday
night with dry and seasonably warm weather expected on Friday
ahead of the shortwave/cold front that approaches from the west.

Have tried to focus likely POPs Friday night and Saturday with this
next system as blended guidance seems to give too long of a period
of POPs when compared to reality. So, after a wet and cooler
beginning to the Labor Day Weekend, it appears chances of
precipitation will decrease for Sunday and Monday (Labor Day), with
temperatures beginning to inch back up above normal in the wake
of this storm system.

CVKING

&&

.AVIATION:  (For the 12z TAFs through 12z Thursday Morning)
Issued at 655 AM CDT Wed Aug 27 2014

Complex of storms continues to develop over northwestern Missouri
and track to the east. Should move into KUIN by 17z and persist
through the afternoon hours. Otherwise, trying to pin down when
storms may develop and move through other tafs sites is difficult,
so for now kept tafs dry. Light winds to pickup from the northeast
to east today as frontal boundary settles over region. Some patchy
dense fog has developed over central MO, but should lift and
dissipate by mid morning today. By tonight, front will be just
south of Interstate 70, so could see some patchy mvfr fog develop
after 06z Thursday, so added tempo mention.

Specifics for KSTL:

Complex of storms continues to develop over northwestern Missouri
and track to the east. Should move remain north of metro area.
Otherwise, trying to pin down when storms may develop and move
through metro area is difficult, so for now kept taf dry. Light
winds to pickup from the northeast to east by 18z as frontal
boundary settles over region. By tonight, front will be just
south of Interstate 70, so could see some patchy mvfr fog develop
after 08z Thursday, so added tempo mention.

Byrd

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$

WFO LSX







000
FXUS63 KLSX 271155
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
655 AM CDT Wed Aug 27 2014

.SYNOPSIS:
Issued at 237 AM CDT Wed Aug 27 2014

Front is slowly making progress into the CWA early this morning
and is currently stretching from near Kansas City, Missouri to
Quincy, Illinois. Some isolated thunderstorms continue to pop up
here and there on outflow boundaries across eastern Missouri and
west central Illinois, with a better defined cluster of convection
now taking shape across far northwest Missouri. Temperatures
remain mild with all locations still in the 70s this morning.

CVKING
&&

.SHORT TERM:  (Through Tonight)
Issued at 237 AM CDT Wed Aug 27 2014

Elevated convection will continue to develop across northern
Missouri early this morning with scattered thunderstorms forecast
through the lunch hour across the northern counties of the CWA.

Front will make very slow progress south today. Temperatures will
quickly rise into the 90s south of the front and due to pooled
dewpoints in the lower to middle 70s, produce at least a few hours
of heat indices above 100 degrees along and south of I-70. Although
it won`t be as hot as the past few days - feel current heat
headlines are warranted given potential for one more day of heat
indices reaching 105 degrees this afternoon.

The front will also serve as the focus for convective initiation
with scattered thunderstorms expected along and south of I-70 this
afternoon. As was the case yesterday, a few of the storms could
produce some gusty winds to 50 mph and torrential downpours.

Diurnal convection expected to dissipate quickly after sunset with
the focus for more elevated development shifting back north of the
boundary across the northern reaches of the CWA after midnight.

CVKING

.LONG TERM: (Thursday through Tuesday)
Issued at 237 AM CDT Wed Aug 27 2014

Boundary will be slow to lift back north on Thursday and may become
orientated more northwest to southeast across the CWA...paralleling
the Mississippi River. Once again, afternoon convection will be
possible in the vicinity of this front.

The boundary should finally lift north as a warm front Thursday
night with dry and seasonably warm weather expected on Friday
ahead of the shortwave/cold front that approaches from the west.

Have tried to focus likely POPs Friday night and Saturday with this
next system as blended guidance seems to give too long of a period
of POPs when compared to reality. So, after a wet and cooler
beginning to the Labor Day Weekend, it appears chances of
precipitation will decrease for Sunday and Monday (Labor Day), with
temperatures beginning to inch back up above normal in the wake
of this storm system.

CVKING
&&

.AVIATION:  (For the 12z TAFs through 12z Thursday Morning)
Issued at 655 AM CDT Wed Aug 27 2014

Complex of storms continues to develop over northwestern Missouri
and track to the east. Should move into KUIN by 17z and persist
through the afternoon hours. Otherwise, trying to pin down when
storms may develop and move through other tafs sites is difficult,
so for now kept tafs dry. Light winds to pickup from the northeast
to east today as frontal boundary settles over region. Some patchy
dense fog has developed over central MO, but should lift and
dissipate by mid morning today. By tonight, front will be just
south of Interstate 70, so could see some patchy mvfr fog develop
after 06z Thursday, so added tempo mention.

Specifics for KSTL:

Complex of storms continues to develop over northwestern Missouri
and track to the east. Should move remain north of metro area.
Otherwise, trying to pin down when storms may develop and move
through metro area is difficult, so for now kept taf dry. Light
winds to pickup from the northeast to east by 18z as frontal
boundary settles over region. By tonight, front will be just
south of Interstate 70, so could see some patchy mvfr fog develop
after 08z Thursday, so added tempo mention.

Byrd
&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$
WFO LSX






000
FXUS63 KLSX 271155
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
655 AM CDT Wed Aug 27 2014

.SYNOPSIS:
Issued at 237 AM CDT Wed Aug 27 2014

Front is slowly making progress into the CWA early this morning
and is currently stretching from near Kansas City, Missouri to
Quincy, Illinois. Some isolated thunderstorms continue to pop up
here and there on outflow boundaries across eastern Missouri and
west central Illinois, with a better defined cluster of convection
now taking shape across far northwest Missouri. Temperatures
remain mild with all locations still in the 70s this morning.

CVKING
&&

.SHORT TERM:  (Through Tonight)
Issued at 237 AM CDT Wed Aug 27 2014

Elevated convection will continue to develop across northern
Missouri early this morning with scattered thunderstorms forecast
through the lunch hour across the northern counties of the CWA.

Front will make very slow progress south today. Temperatures will
quickly rise into the 90s south of the front and due to pooled
dewpoints in the lower to middle 70s, produce at least a few hours
of heat indices above 100 degrees along and south of I-70. Although
it won`t be as hot as the past few days - feel current heat
headlines are warranted given potential for one more day of heat
indices reaching 105 degrees this afternoon.

The front will also serve as the focus for convective initiation
with scattered thunderstorms expected along and south of I-70 this
afternoon. As was the case yesterday, a few of the storms could
produce some gusty winds to 50 mph and torrential downpours.

Diurnal convection expected to dissipate quickly after sunset with
the focus for more elevated development shifting back north of the
boundary across the northern reaches of the CWA after midnight.

CVKING

.LONG TERM: (Thursday through Tuesday)
Issued at 237 AM CDT Wed Aug 27 2014

Boundary will be slow to lift back north on Thursday and may become
orientated more northwest to southeast across the CWA...paralleling
the Mississippi River. Once again, afternoon convection will be
possible in the vicinity of this front.

The boundary should finally lift north as a warm front Thursday
night with dry and seasonably warm weather expected on Friday
ahead of the shortwave/cold front that approaches from the west.

Have tried to focus likely POPs Friday night and Saturday with this
next system as blended guidance seems to give too long of a period
of POPs when compared to reality. So, after a wet and cooler
beginning to the Labor Day Weekend, it appears chances of
precipitation will decrease for Sunday and Monday (Labor Day), with
temperatures beginning to inch back up above normal in the wake
of this storm system.

CVKING
&&

.AVIATION:  (For the 12z TAFs through 12z Thursday Morning)
Issued at 655 AM CDT Wed Aug 27 2014

Complex of storms continues to develop over northwestern Missouri
and track to the east. Should move into KUIN by 17z and persist
through the afternoon hours. Otherwise, trying to pin down when
storms may develop and move through other tafs sites is difficult,
so for now kept tafs dry. Light winds to pickup from the northeast
to east today as frontal boundary settles over region. Some patchy
dense fog has developed over central MO, but should lift and
dissipate by mid morning today. By tonight, front will be just
south of Interstate 70, so could see some patchy mvfr fog develop
after 06z Thursday, so added tempo mention.

Specifics for KSTL:

Complex of storms continues to develop over northwestern Missouri
and track to the east. Should move remain north of metro area.
Otherwise, trying to pin down when storms may develop and move
through metro area is difficult, so for now kept taf dry. Light
winds to pickup from the northeast to east by 18z as frontal
boundary settles over region. By tonight, front will be just
south of Interstate 70, so could see some patchy mvfr fog develop
after 08z Thursday, so added tempo mention.

Byrd
&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY until 8 PM CDT this evening FOR Audrain MO-Boone
     MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
     Iron MO-Madison MO-Moniteau MO-Montgomery MO-Osage MO-
     Reynolds MO-St. Francois MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

     EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Jefferson
     MO-Lincoln MO-St. Charles MO-St. Louis City MO-St. Louis MO.

IL...EXCESSIVE HEAT WARNING until 8 PM CDT this evening FOR Bond IL-
     Calhoun IL-Clinton IL-Fayette IL-Greene IL-Jersey IL-
     Macoupin IL-Madison IL-Marion IL-Monroe IL-Montgomery IL-
     Randolph IL-St. Clair IL-Washington IL.

&&

$$
WFO LSX







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