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000
FXUS63 KLSX 281159
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
659 AM CDT Thu May 28 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 323 AM CDT Thu May 28 2015

Weak frontal boundary that moved south through forecast area
yesterday has stalled out just south of region. It will begin to
lift back north through forecast area today, with some scattered
showers and thunderstorms possible mainly during the afternoon
hours. In the meantime, storm complex over central Kansas early
this morning will continue to track to the east, reaching central
MO by midday. At this point, it will be in the weakening stages.
Otherwise, it will be warm and a bit muggy with highs in the low
to mid 80s and dewpts in the 60s.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 323 AM CDT Thu May 28 2015

By tonight, first in a series of more vigorous shortwaves will begin
to slide through forecast area. Showers and thunderstorms will be on
the increase with best chances still expected Friday through
Saturday. As for severe weather potential, it will be with main cold
front Friday afternoon and night, and again on Saturday. It
continues to hinge on how much instability can be attained in the
warm sector ahead of boundary.

Temperatures will remain on the warm side through Friday, with highs
in the 80s. Then colder air to filter in as front moves through. By
Sunday, precipitation to taper off and will see highs only in the
60s.

Beyond that, upper low becomes cut off and lingers over Arkansas
through rest of forecast period. Could see diurnally driven showers
and thunderstorms, mainly for southern portions of forecast area,
from Monday through Wednesday, so have slight chance pops during the
daytime hours. Highs to moderate through the period, warming back
into the 80s by Wednesday.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Friday Morning)
Issued at 629 AM CDT Thu May 28 2015

Earlier fog that had moved into KSUS and KCPS has already burned
off, so have left it out initial issuance of the TAF. Should see
mainly dry and VFR conditions the rest of the morning as the fog
and lower ceilings are staying well south and east of the St.
Louis metro TAF sites. Only concern for the forecast period is
thunderstorms which some models are showing developing at KCOU and
KUIN during the afternoon and evening hours. There is still some
uncertainty on the timing and whether or not they will develop or
not, so have just gone with VCTS for now. Chances are less at the
St. Louis metro airports, so have just left them dry.

Specifics for KSTL: Expect dry and VFR conditions for now with
winds increasing from the southeast by mid-morning.

Britt

&&

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

$$

WFO LSX








000
FXUS63 KLSX 281159
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
659 AM CDT Thu May 28 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 323 AM CDT Thu May 28 2015

Weak frontal boundary that moved south through forecast area
yesterday has stalled out just south of region. It will begin to
lift back north through forecast area today, with some scattered
showers and thunderstorms possible mainly during the afternoon
hours. In the meantime, storm complex over central Kansas early
this morning will continue to track to the east, reaching central
MO by midday. At this point, it will be in the weakening stages.
Otherwise, it will be warm and a bit muggy with highs in the low
to mid 80s and dewpts in the 60s.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 323 AM CDT Thu May 28 2015

By tonight, first in a series of more vigorous shortwaves will begin
to slide through forecast area. Showers and thunderstorms will be on
the increase with best chances still expected Friday through
Saturday. As for severe weather potential, it will be with main cold
front Friday afternoon and night, and again on Saturday. It
continues to hinge on how much instability can be attained in the
warm sector ahead of boundary.

Temperatures will remain on the warm side through Friday, with highs
in the 80s. Then colder air to filter in as front moves through. By
Sunday, precipitation to taper off and will see highs only in the
60s.

Beyond that, upper low becomes cut off and lingers over Arkansas
through rest of forecast period. Could see diurnally driven showers
and thunderstorms, mainly for southern portions of forecast area,
from Monday through Wednesday, so have slight chance pops during the
daytime hours. Highs to moderate through the period, warming back
into the 80s by Wednesday.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Friday Morning)
Issued at 629 AM CDT Thu May 28 2015

Earlier fog that had moved into KSUS and KCPS has already burned
off, so have left it out initial issuance of the TAF. Should see
mainly dry and VFR conditions the rest of the morning as the fog
and lower ceilings are staying well south and east of the St.
Louis metro TAF sites. Only concern for the forecast period is
thunderstorms which some models are showing developing at KCOU and
KUIN during the afternoon and evening hours. There is still some
uncertainty on the timing and whether or not they will develop or
not, so have just gone with VCTS for now. Chances are less at the
St. Louis metro airports, so have just left them dry.

Specifics for KSTL: Expect dry and VFR conditions for now with
winds increasing from the southeast by mid-morning.

Britt

&&

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

$$

WFO LSX







000
FXUS63 KLSX 280825
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
325 AM CDT Thu May 28 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 323 AM CDT Thu May 28 2015

Weak frontal boundary that moved south through forecast area
yesterday has stalled out just south of region. It will begin to
lift back north through forecast area today, with some scattered
showers and thunderstorms possible mainly during the afternoon
hours. In the meantime, storm complex over central Kansas early
this morning will continue to track to the east, reaching central
MO by midday. At this point, it will be in the weakening stages.
Otherwise, it will be warm and a bit muggy with highs in the low
to mid 80s and dewpts in the 60s.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 323 AM CDT Thu May 28 2015

By tonight, first in a series of more vigorous shortwaves will begin
to slide through forecast area. Showers and thunderstorms will be on
the increase with best chances still expected Friday through
Saturday. As for severe weather potential, it will be with main cold
front Friday afternoon and night, and again on Saturday. It
continues to hinge on how much instability can be attained in the
warm sector ahead of boundary.

Temperatures will remain on the warm side through Friday, with highs
in the 80s. Then colder air to filter in as front moves through. By
Sunday, precipitation to taper off and will see highs only in the
60s.

Beyond that, upper low becomes cut off and lingers over Arkansas
through rest of forecast period. Could see diurnally driven showers
and thunderstorms, mainly for southern portions of forecast area,
from Monday through Wednesday, so have slight chance pops during the
daytime hours. Highs to moderate through the period, warming back
into the 80s by Wednesday.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1111 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS this evening with weak
surface ridging behind it over northeast MO and northern IL.
Light surface wind will become sely on Thursday as the surface
ridge shifts well east of the area and as the front lifts back
northward as a warm front. Diurnal cumulus clouds will develop
late Thursday morning and afternoon. There should be isolated to
scattered showers/storms Thursday afternoon into the evening as
an upper level disturbance approaches with the best coverage
likely in the COU area.

Specifics for KSTL: Diurnal cumulus clouds will develop late
Thursday morning and afternoon. There will likely be isolated
showers/storms Thursday afternoon into the evening, but will
leave the STL taf dry for now. Light surface wind late tonight
will strengthen to around 8 kts by Thursday afternoon from a sely
direction.

GKS
&&

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

$$
WFO LSX






000
FXUS63 KLSX 280825
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
325 AM CDT Thu May 28 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 323 AM CDT Thu May 28 2015

Weak frontal boundary that moved south through forecast area
yesterday has stalled out just south of region. It will begin to
lift back north through forecast area today, with some scattered
showers and thunderstorms possible mainly during the afternoon
hours. In the meantime, storm complex over central Kansas early
this morning will continue to track to the east, reaching central
MO by midday. At this point, it will be in the weakening stages.
Otherwise, it will be warm and a bit muggy with highs in the low
to mid 80s and dewpts in the 60s.

Byrd

.LONG TERM:  (Tonight through Wednesday)
Issued at 323 AM CDT Thu May 28 2015

By tonight, first in a series of more vigorous shortwaves will begin
to slide through forecast area. Showers and thunderstorms will be on
the increase with best chances still expected Friday through
Saturday. As for severe weather potential, it will be with main cold
front Friday afternoon and night, and again on Saturday. It
continues to hinge on how much instability can be attained in the
warm sector ahead of boundary.

Temperatures will remain on the warm side through Friday, with highs
in the 80s. Then colder air to filter in as front moves through. By
Sunday, precipitation to taper off and will see highs only in the
60s.

Beyond that, upper low becomes cut off and lingers over Arkansas
through rest of forecast period. Could see diurnally driven showers
and thunderstorms, mainly for southern portions of forecast area,
from Monday through Wednesday, so have slight chance pops during the
daytime hours. Highs to moderate through the period, warming back
into the 80s by Wednesday.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1111 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS this evening with weak
surface ridging behind it over northeast MO and northern IL.
Light surface wind will become sely on Thursday as the surface
ridge shifts well east of the area and as the front lifts back
northward as a warm front. Diurnal cumulus clouds will develop
late Thursday morning and afternoon. There should be isolated to
scattered showers/storms Thursday afternoon into the evening as
an upper level disturbance approaches with the best coverage
likely in the COU area.

Specifics for KSTL: Diurnal cumulus clouds will develop late
Thursday morning and afternoon. There will likely be isolated
showers/storms Thursday afternoon into the evening, but will
leave the STL taf dry for now. Light surface wind late tonight
will strengthen to around 8 kts by Thursday afternoon from a sely
direction.

GKS
&&

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

$$
WFO LSX







000
FXUS63 KLSX 280427
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1127 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1111 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS this evening with weak
surface ridging behind it over northeast MO and northern IL.
Light surface wind will become sely on Thursday as the surface
ridge shifts well east of the area and as the front lifts back
northward as a warm front. Diurnal cumulus clouds will develop
late Thursday morning and afternoon. There should be isolated to
scattered showers/storms Thursday afternoon into the evening as
an upper level disturbance approaches with the best coverage
likely in the COU area.

Specifics for KSTL: Diurnal cumulus clouds will develop late
Thursday morning and afternoon. There will likely be isolated
showers/storms Thursday afternoon into the evening, but will
leave the STL taf dry for now. Light surface wind late tonight
will strengthen to around 8 kts by Thursday afternoon from a sely
direction.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  86 /  10  30  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  82  65  80 /  20  50  40  70
Jefferson City  62  83  65  81 /  20  50  40  60
Salem           65  84  68  85 /  10  20  20  40
Farmington      62  82  65  83 /  20  30  30  50

&&

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

$$

WFO LSX








000
FXUS63 KLSX 280427
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1127 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1111 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS this evening with weak
surface ridging behind it over northeast MO and northern IL.
Light surface wind will become sely on Thursday as the surface
ridge shifts well east of the area and as the front lifts back
northward as a warm front. Diurnal cumulus clouds will develop
late Thursday morning and afternoon. There should be isolated to
scattered showers/storms Thursday afternoon into the evening as
an upper level disturbance approaches with the best coverage
likely in the COU area.

Specifics for KSTL: Diurnal cumulus clouds will develop late
Thursday morning and afternoon. There will likely be isolated
showers/storms Thursday afternoon into the evening, but will
leave the STL taf dry for now. Light surface wind late tonight
will strengthen to around 8 kts by Thursday afternoon from a sely
direction.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  86 /  10  30  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  82  65  80 /  20  50  40  70
Jefferson City  62  83  65  81 /  20  50  40  60
Salem           65  84  68  85 /  10  20  20  40
Farmington      62  82  65  83 /  20  30  30  50

&&

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

$$

WFO LSX







000
FXUS63 KLSX 280427
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1127 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1111 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS this evening with weak
surface ridging behind it over northeast MO and northern IL.
Light surface wind will become sely on Thursday as the surface
ridge shifts well east of the area and as the front lifts back
northward as a warm front. Diurnal cumulus clouds will develop
late Thursday morning and afternoon. There should be isolated to
scattered showers/storms Thursday afternoon into the evening as
an upper level disturbance approaches with the best coverage
likely in the COU area.

Specifics for KSTL: Diurnal cumulus clouds will develop late
Thursday morning and afternoon. There will likely be isolated
showers/storms Thursday afternoon into the evening, but will
leave the STL taf dry for now. Light surface wind late tonight
will strengthen to around 8 kts by Thursday afternoon from a sely
direction.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  86 /  10  30  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  82  65  80 /  20  50  40  70
Jefferson City  62  83  65  81 /  20  50  40  60
Salem           65  84  68  85 /  10  20  20  40
Farmington      62  82  65  83 /  20  30  30  50

&&

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

$$

WFO LSX







000
FXUS63 KLSX 280427
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1127 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Thursday Night)
Issued at 1111 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS this evening with weak
surface ridging behind it over northeast MO and northern IL.
Light surface wind will become sely on Thursday as the surface
ridge shifts well east of the area and as the front lifts back
northward as a warm front. Diurnal cumulus clouds will develop
late Thursday morning and afternoon. There should be isolated to
scattered showers/storms Thursday afternoon into the evening as
an upper level disturbance approaches with the best coverage
likely in the COU area.

Specifics for KSTL: Diurnal cumulus clouds will develop late
Thursday morning and afternoon. There will likely be isolated
showers/storms Thursday afternoon into the evening, but will
leave the STL taf dry for now. Light surface wind late tonight
will strengthen to around 8 kts by Thursday afternoon from a sely
direction.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  86 /  10  30  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  82  65  80 /  20  50  40  70
Jefferson City  62  83  65  81 /  20  50  40  60
Salem           65  84  68  85 /  10  20  20  40
Farmington      62  82  65  83 /  20  30  30  50

&&

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

$$

WFO LSX








000
FXUS63 KLSX 272311
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
611 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 00z TAFs through 00z Thursday Evening)
Issued at 545 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS early this evening with
weak surface ridging behind it over north central MO. Cumulus
field over the St Louis metro area should dissipate later this
evening due to the loss of daytime heating and as the front
continues to shift slowly southeastard. The surface wind will
become light later this evening, then become sely on Thursday as
the surface ridge shifts east of the area and as the front lifts
back northward as a warm front. Diurnal cumulus clouds will
develop late Thursday morning and afternoon. There may be isolated
to scattered showers/storms Thursday afternoon as an upper level
disturbance approaches with the best coverage likely in the COU
area.

Specifics for KSTL: Cumulus clouds will dissipate early this
evening, but then redevelop late Thursday morning and afternoon.
There may be isolated showers/storms Thursday afternoon, but will
leave the STL taf dry for now. Nwly surface wind will become light
later this evening, then strengthen to around 8-9 kts by Thursday
afternoon from a sely direction.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  85 /  10  20  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  81  66  80 /  20  50  40  60
Jefferson City  63  83  67  80 /  20  50  40  60
Salem           65  84  68  85 /  20  20  20  40
Farmington      63  82  66  82 /  30  30  20  50

&&

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

$$

WFO LSX







000
FXUS63 KLSX 272311
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
611 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 00z TAFs through 00z Thursday Evening)
Issued at 545 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS early this evening with
weak surface ridging behind it over north central MO. Cumulus
field over the St Louis metro area should dissipate later this
evening due to the loss of daytime heating and as the front
continues to shift slowly southeastard. The surface wind will
become light later this evening, then become sely on Thursday as
the surface ridge shifts east of the area and as the front lifts
back northward as a warm front. Diurnal cumulus clouds will
develop late Thursday morning and afternoon. There may be isolated
to scattered showers/storms Thursday afternoon as an upper level
disturbance approaches with the best coverage likely in the COU
area.

Specifics for KSTL: Cumulus clouds will dissipate early this
evening, but then redevelop late Thursday morning and afternoon.
There may be isolated showers/storms Thursday afternoon, but will
leave the STL taf dry for now. Nwly surface wind will become light
later this evening, then strengthen to around 8-9 kts by Thursday
afternoon from a sely direction.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  85 /  10  20  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  81  66  80 /  20  50  40  60
Jefferson City  63  83  67  80 /  20  50  40  60
Salem           65  84  68  85 /  20  20  20  40
Farmington      63  82  66  82 /  30  30  20  50

&&

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

$$

WFO LSX







000
FXUS63 KLSX 272311
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
611 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 00z TAFs through 00z Thursday Evening)
Issued at 545 PM CDT Wed May 27 2015

Cold front has pushed southeast of CPS early this evening with
weak surface ridging behind it over north central MO. Cumulus
field over the St Louis metro area should dissipate later this
evening due to the loss of daytime heating and as the front
continues to shift slowly southeastard. The surface wind will
become light later this evening, then become sely on Thursday as
the surface ridge shifts east of the area and as the front lifts
back northward as a warm front. Diurnal cumulus clouds will
develop late Thursday morning and afternoon. There may be isolated
to scattered showers/storms Thursday afternoon as an upper level
disturbance approaches with the best coverage likely in the COU
area.

Specifics for KSTL: Cumulus clouds will dissipate early this
evening, but then redevelop late Thursday morning and afternoon.
There may be isolated showers/storms Thursday afternoon, but will
leave the STL taf dry for now. Nwly surface wind will become light
later this evening, then strengthen to around 8-9 kts by Thursday
afternoon from a sely direction.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  85 /  10  20  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  81  66  80 /  20  50  40  60
Jefferson City  63  83  67  80 /  20  50  40  60
Salem           65  84  68  85 /  20  20  20  40
Farmington      63  82  66  82 /  30  30  20  50

&&

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

$$

WFO LSX








000
FXUS63 KLSX 272119
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
419 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1225 PM CDT Wed May 27 2015

VFR conditions expected into Thursday morning at all TAF sites.
Light west to northwest winds this afternoon will become variable
around sunset...then southeasterly Thursday morning. MVFR ceilings
near 3000 feet AGL will move into KCOU TAF site by around 15Z
Thursday...and reach the KSTL metro TAF sites by around 20Z.

Specifics for KSTL: VFR conditions with light west winds this
afternoon. Winds will become light and variable overnight...then
southeasterly by around 15Z Thursday. Ceilings around 3000 feet
should approach the TAF site by 20Z Thursday.

Browning

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  85 /  10  20  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  81  66  80 /  20  50  40  60
Jefferson City  63  83  67  80 /  20  50  40  60
Salem           65  84  68  85 /  20  20  20  40
Farmington      63  82  66  82 /  30  30  20  50

&&

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

$$

WFO LSX







000
FXUS63 KLSX 272119
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
419 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 415 PM CDT Wed May 27 2015

Cold front has now passed through STL metro, and should sink a bit
more south before stalling out over southern sections of the CWA
this evening.  Convergence is quite weak in the vicinity of the
front, but instability has recovered in the wake of the morning
complex, with 19z MLCAPES of up to 1500 J/Kg over the Ozarks.  Have
continued chance/slight chance PoPs over this area for the evening
hours as some development could occur at any time between now and
7-8pm.  Across northern portions of our CWA, the cooler and drier
air north of the front should make for a very comfortable late May
evening, with weak surface ridge pushes from northern MO into
central IL.

While primary threat of convection in our FA tonight (such as it is)
should be tied to the late afternoon/early evening instability
across the south, have maintained slight chance PoPs across the
south throughout the overnight and into the predawn hours as frontal
boundary will remain parked over this area, In addition, have
actually pushed these slight chance PoPs north into mid Missouri by
daybreak as return flow develops in the wake of the aforementioned
surface ridge, producing weak overrunning of the stalled front.
Certainly, greatest lift/moisture return will be west of our CWA,
but if convection does develop over western MO during the predawn
hours some of this may activity may be able to trickle into our
western counties by 12z.


Truett

.LONG TERM:  (Thursday through Next Wednesday)
Issued at 415 PM CDT Wed May 27 2015

(Thursday-Saturday)

12z guidance continues to support earlier forecasts that indicate
increasingly unsettled conditions as we head into the latter part of
the week.  Today`s various 12z NWP outputs are all similar
synoptically, and indicate a broad southerly flow advecting warm and
increasing moist air into the mid-Mississippi Valley on Thu-Thu
night, with several shortwaves ejecting from the upper trof over the
west coast interacting with this increasingly unstable airmass over
the region.  For now have gone with fairly broad brush chance PoPs
during this time range, with the greatest chances over northwest
sections of the CWA where dynamics and moisture should be somewhat
maximized.  However, it`s certainly possible that meso-scale
processes will force some short-range adjustments to this thinking.

Good model consensus continues into the end of the week, with all
solutions progging a strong cold front across the region from late
Friday into Saturday as west coast trof also works into the central
CONUS. With the ample moisture, strong lift, and instability have
gone with likely PoPs as the front traverses the CWA, and its
certainly possible that these will ultimately be too low.  Not
totally clear on severe weather potential on Friday afternoon and
Friday night as large scale shear is fairly weak and progged
soundings look rather soupy, and at this point it appears that
severe thunderstorm potential will likely hinge on how much
instability can be attained in the warm sector.

Temperatures will remain on the warm side through Friday, but are
expected to drop back into the 70s by Saturday as the cold air
begins to exert its influence over the area.

(Sunday-Wednesday)

The cool down that begins on Saturday will intensify on Sunday as
the strong surface ridge building into the upper Great Lakes sends
chilly Canadian air into the region. Latest guidance suggests
clouds along with a few lingering showers/thunderstorms persisting
over about the southeast half of the CWA, and these clouds and
potential precip along with the chilly air should mean highs only
in the 60s for most of the CWA.

While it looks rather odd for late May, all of the medium range
solutions are forecasting a cut- off upper low to develop in the
vicinity of the Bootheel on Monday, with this low then gradually
drifting south with time. Temperature trends during the Mon-Tue
time frame will indicate a gradual return to near average levels,
although am wondering if this moderation may be a bit too fast if
the upper system hangs around.

Don`t see any large precip threat during this time, but did
continue some low PoPs in a few spots Mon and Tue with weak
ripples rotating around the upper low.

Truett

&&

.AVIATION:  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1225 PM CDT Wed May 27 2015

VFR conditions expected into Thursday morning at all TAF sites.
Light west to northwest winds this afternoon will become variable
around sunset...then southeasterly Thursday morning. MVFR ceilings
near 3000 feet AGL will move into KCOU TAF site by around 15Z
Thursday...and reach the KSTL metro TAF sites by around 20Z.

Specifics for KSTL: VFR conditions with light west winds this
afternoon. Winds will become light and variable overnight...then
southeasterly by around 15Z Thursday. Ceilings around 3000 feet
should approach the TAF site by 20Z Thursday.

Browning

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  85  70  85 /  10  20  30  50
Quincy          61  82  66  81 /  10  20  40  60
Columbia        62  81  66  80 /  20  50  40  60
Jefferson City  63  83  67  80 /  20  50  40  60
Salem           65  84  68  85 /  20  20  20  40
Farmington      63  82  66  82 /  30  30  20  50

&&

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

$$

WFO LSX








000
FXUS63 KLSX 271735
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1235 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 328 AM CDT Wed May 27 2015

Weak frontal boundary to slowly slide southeast through region
today. Initial activity over northern portions of forecast area to
exit before zone issuance. Next round firing up over southwestern MO
and moving east northeast towards forecast area. HRRR keeps activity
along and south of I-70 this morning before diminishing. So highest
pops will be over southern portions of forecast area. Otherwise,
warm conditions to persist with highs in the low to mid 80s.

Byrd

.LONG TERM:  (Tonight through Tuesday)
Issued at 328 AM CDT Wed May 27 2015

Weak ridging to build in tonight with precipitation tapering off.
Did keep slights/low chance pops for southern portions of forecast
area, but for the most part forecast area should be dry overnight.
On Thursday, more vigorous shortwave to approach from the
southwest. Will see increasing pops with best chances over central
and southern Missouri during the day, then chances to increase
beginning Thursday night as deepening upper level trof over the
Rockies begins to slide towards region. Best chances will be
Friday through Saturday, before tapering off on Sunday.

Highs will be in the 80s for the rest of the work week with lows in
the 60s. Cooler air to filter in behind this system with highs only
in the upper 60s on Sunday, then warm back up into the upper 70s to
low 80s by next Tuesday.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1225 PM CDT Wed May 27 2015

VFR conditions expected into Thursday morning at all TAF sites.
Light west to northwest winds this afternoon will become variable
around sunset...then southeasterly Thursday morning. MVFR ceilings
near 3000 feet AGL will move into KCOU TAF site by around 15Z
Thursday...and reach the KSTL metro TAF sites by around 20Z.

Specifics for KSTL: VFR conditions with light west winds this
afternoon. Winds will become light and variable overnight...then
southeasterly by around 15Z Thursday. Ceilings around 3000 feet
should approach the TAF site by 20Z Thursday.

Browning

&&

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

$$

WFO LSX








000
FXUS63 KLSX 271735
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1235 PM CDT Wed May 27 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 328 AM CDT Wed May 27 2015

Weak frontal boundary to slowly slide southeast through region
today. Initial activity over northern portions of forecast area to
exit before zone issuance. Next round firing up over southwestern MO
and moving east northeast towards forecast area. HRRR keeps activity
along and south of I-70 this morning before diminishing. So highest
pops will be over southern portions of forecast area. Otherwise,
warm conditions to persist with highs in the low to mid 80s.

Byrd

.LONG TERM:  (Tonight through Tuesday)
Issued at 328 AM CDT Wed May 27 2015

Weak ridging to build in tonight with precipitation tapering off.
Did keep slights/low chance pops for southern portions of forecast
area, but for the most part forecast area should be dry overnight.
On Thursday, more vigorous shortwave to approach from the
southwest. Will see increasing pops with best chances over central
and southern Missouri during the day, then chances to increase
beginning Thursday night as deepening upper level trof over the
Rockies begins to slide towards region. Best chances will be
Friday through Saturday, before tapering off on Sunday.

Highs will be in the 80s for the rest of the work week with lows in
the 60s. Cooler air to filter in behind this system with highs only
in the upper 60s on Sunday, then warm back up into the upper 70s to
low 80s by next Tuesday.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1225 PM CDT Wed May 27 2015

VFR conditions expected into Thursday morning at all TAF sites.
Light west to northwest winds this afternoon will become variable
around sunset...then southeasterly Thursday morning. MVFR ceilings
near 3000 feet AGL will move into KCOU TAF site by around 15Z
Thursday...and reach the KSTL metro TAF sites by around 20Z.

Specifics for KSTL: VFR conditions with light west winds this
afternoon. Winds will become light and variable overnight...then
southeasterly by around 15Z Thursday. Ceilings around 3000 feet
should approach the TAF site by 20Z Thursday.

Browning

&&

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

$$

WFO LSX







000
FXUS63 KLSX 271140
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
640 AM CDT Wed May 27 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 328 AM CDT Wed May 27 2015

Weak frontal boundary to slowly slide southeast through region
today. Initial activity over northern portions of forecast area to
exit before zone issuance. Next round firing up over southwestern MO
and moving east northeast towards forecast area. HRRR keeps activity
along and south of I-70 this morning before diminishing. So highest
pops will be over southern portions of forecast area. Otherwise,
warm conditions to persist with highs in the low to mid 80s.

Byrd

.LONG TERM:  (Tonight through Tuesday)
Issued at 328 AM CDT Wed May 27 2015

Weak ridging to build in tonight with precipitation tapering off.
Did keep slights/low chance pops for southern portions of forecast
area, but for the most part forecast area should be dry overnight.
On Thursday, more vigorous shortwave to approach from the
southwest. Will see increasing pops with best chances over central
and southern Missouri during the day, then chances to increase
beginning Thursday night as deepening upper level trof over the
Rockies begins to slide towards region. Best chances will be
Friday through Saturday, before tapering off on Sunday.

Highs will be in the 80s for the rest of the work week with lows in
the 60s. Cooler air to filter in behind this system with highs only
in the upper 60s on Sunday, then warm back up into the upper 70s to
low 80s by next Tuesday.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Thursday Morning)
Issued at 640 AM CDT Wed May 27 2015

Recent radar trends are showing showers moving up toward KCPS and
just south of KSUS/KSTL. Went ahead and added TEMPO groups for
MVFR conditions in -SHRA through 14Z at KCPS, and added VCSH at
KSUS/KSTL. Expect this area of showers and thunderstorms to move
out of the area by mid morning leaving the rest of the TAF period
dry with VFR conditions. Winds will turn light and variable at
most of the terminals tonight.

Specifics for KSTL: The terminal will lie on the northern periphery
of a large area of showers and thunderstorms through 14Z. Have
added just VCSH for now with just VFR conditions, but may need to
amend to add -SHRA if showers move farther northward than
expected. Otherwise expect dry and VFR conditions the rest of the
TAF period.

Britt

&&

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

$$

WFO LSX







000
FXUS63 KLSX 271140
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
640 AM CDT Wed May 27 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 328 AM CDT Wed May 27 2015

Weak frontal boundary to slowly slide southeast through region
today. Initial activity over northern portions of forecast area to
exit before zone issuance. Next round firing up over southwestern MO
and moving east northeast towards forecast area. HRRR keeps activity
along and south of I-70 this morning before diminishing. So highest
pops will be over southern portions of forecast area. Otherwise,
warm conditions to persist with highs in the low to mid 80s.

Byrd

.LONG TERM:  (Tonight through Tuesday)
Issued at 328 AM CDT Wed May 27 2015

Weak ridging to build in tonight with precipitation tapering off.
Did keep slights/low chance pops for southern portions of forecast
area, but for the most part forecast area should be dry overnight.
On Thursday, more vigorous shortwave to approach from the
southwest. Will see increasing pops with best chances over central
and southern Missouri during the day, then chances to increase
beginning Thursday night as deepening upper level trof over the
Rockies begins to slide towards region. Best chances will be
Friday through Saturday, before tapering off on Sunday.

Highs will be in the 80s for the rest of the work week with lows in
the 60s. Cooler air to filter in behind this system with highs only
in the upper 60s on Sunday, then warm back up into the upper 70s to
low 80s by next Tuesday.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Thursday Morning)
Issued at 640 AM CDT Wed May 27 2015

Recent radar trends are showing showers moving up toward KCPS and
just south of KSUS/KSTL. Went ahead and added TEMPO groups for
MVFR conditions in -SHRA through 14Z at KCPS, and added VCSH at
KSUS/KSTL. Expect this area of showers and thunderstorms to move
out of the area by mid morning leaving the rest of the TAF period
dry with VFR conditions. Winds will turn light and variable at
most of the terminals tonight.

Specifics for KSTL: The terminal will lie on the northern periphery
of a large area of showers and thunderstorms through 14Z. Have
added just VCSH for now with just VFR conditions, but may need to
amend to add -SHRA if showers move farther northward than
expected. Otherwise expect dry and VFR conditions the rest of the
TAF period.

Britt

&&

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

$$

WFO LSX








000
FXUS63 KLSX 270829
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
329 AM CDT Wed May 27 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 328 AM CDT Wed May 27 2015

Weak frontal boundary to slowly slide southeast through region
today. Initial activity over northern portions of forecast area to
exit before zone issuance. Next round firing up over southwestern MO
and moving east northeast towards forecast area. HRRR keeps activity
along and south of I-70 this morning before diminishing. So highest
pops will be over southern portions of forecast area. Otherwise,
warm conditions to persist with highs in the low to mid 80s.

Byrd

.LONG TERM:  (Tonight through Tuesday)
Issued at 328 AM CDT Wed May 27 2015

Weak ridging to build in tonight with precipitation tapering off.
Did keep slights/low chance pops for southern portions of forecast
area, but for the most part forecast area should be dry overnight.
On Thursday, more vigorous shortwave to approach from the
southwest. Will see increasing pops with best chances over central
and southern Missouri during the day, then chances to increase
beginning Thursday night as deepening upper level trof over the
Rockies begins to slide towards region. Best chances will be
Friday through Saturday, before tapering off on Sunday.

Highs will be in the 80s for the rest of the work week with lows in
the 60s. Cooler air to filter in behind this system with highs only
in the upper 60s on Sunday, then warm back up into the upper 70s to
low 80s by next Tuesday.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1140 PM CDT Tue May 26 2015

Isld/scttrd SHRAs will continue to dot the area thru the prd. Weak
forcing along a diffuse bndry will keep sporadic precip percolating.
Current activity across cntrl/NE MO and w cntrl IL should slowly
dsspt/move NE after 6Z. Guidance hints at another batch of convection
dvlpng across SW MO tonight. This precip, if it dvlps, will move
NE but appears to remain south of the STL metro terminals. Limited
coverage precludes mention attm. SHRA coverage may increase Wed aftn
with the highest coverage expected to be east of the STL metro. Winds
will become wrly Wed mrng.

Specifics for KSTL:

VFR fcst thru the prd though there will be isld/scttrd SHRAs. A weak
bndry will push thru the terminal drng the late mrng allwoing winds
to become more wrly and taking the better chance of rain with it.
Limited coverage precludes mention in the fcst attm.

2%
&&

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

$$
WFO LSX







000
FXUS63 KLSX 270500
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1200 AM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 400 PM CDT Tue May 26 2015

The primary forecast issue for tonight is convective trends. A
nearly stacked low pressure system will continue progressing
northeastward towards the Great Lakes tonight, trailing a weak cold
front in its wake. This front will edge into northern MO overnight
before stalling across the region tomorrow. Most models depict a
couple of vorticity maxima rotating into the back side of the
lifting shortwave trough tonight, and the strongest of these
features will provide large-scale ascent across the northern part of
the CWA between 06-12z. Increasing H7-H5 lapse rates spreading
across the region will contribute to instability. There are also
some hints of a H25 jet streak developing across parts of MO which
places the northern CWA beneath the favorable LER. None of these
features by itself looks particularly strong, but taken together
they support a chance of SH/TS accompanying the cold front as it
sinks slowly southward overnight.

One area of uncertainty for tonight is that some models also develop
a southern branch of the LLJ pointed into southwestern MO by 06z.
The models which show a stronger LLJ appear to be developing it as a
response to a vort max lifting out of the southern plains, but it`s
not clear whether that vort max exists in the real atmosphere. On
the other hand, a small thunderstorm complex recently developed over
south-central OK, which is approximately where that feature ought to
be if it does exist. Whether it`s an actual shortwave or just a
remnant MCV, it could provide support for SH/TS given the greater
MUCAPE and better lapse rates which are forecast to be in place over
the southern part of the CWA.

Kanofsky

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 400 PM CDT Tue May 26 2015

In general, short range models are suggesting AMS over the central
CONUS will remain rather unsettled into the end of this week. It
appears that vorticity maxima/shortwaves rotating around the upper
low overnight tonight will exit our area on Wednesday, with
shortwave ridging in the wake of these features advecting into the
mid-Mississippi Valley by Wednesday night.  At this point, not
exactly sure how to handle convective trends on Wednesday;
certainly, primary threat during the morning will be tied to
movement of predawn convection across the CWA. For the afternoon
hours AMS is forecast to destabilize, but aforementioned shortwave
energy will have exited the FA by that time which may tend to
inhibit coverage of any redevelopment, and convergence along the
weak cold front will be rather feeble. I`ve continued some mention
of convection over most of the CWA during the afternoon, with this
threat diminishing and sinking south Wednesday night with the
front, and as upper level ridge builds into the area.

From Thursday into the weekend, southwest flow will dominate the
UA pattern over the central CONUS, with a series of shortwaves
forecast to eject into our area from the longwave trof over the
western U.S. Initially on Thursday, threat will remain in the
chance category as large scale lift is weak and moisture return is
still somewhat limited. However, likely PoPs should overspread
the region Friday-Saturday as there is model consensus that a
fairly robust shortwave and associated cold front will be
impacting the region at this time.

Lesser shower and thunderstorm chances will linger into the start
of the new week as weak ripples continue to propagate through the
area.

Temperatures will remain a bit above average through Friday, then
cool off over the weekend as the colder air works its way into the
mid-Mississippi Valley. For now I`ve pretty much stayed with
guidance that has highs in the 60s to lower 70s on Sunday, but
wonder given the progged upper air patter if this may be a bit too
cool. Will have to monitor upcoming medium range solutions on this
cool down over the next few days and nights.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1140 PM CDT Tue May 26 2015

Isld/scttrd SHRAs will continue to dot the area thru the prd. Weak
forcing along a diffuse bndry will keep sporadic precip percolating.
Current activity across cntrl/NE MO and w cntrl IL should slowly
dsspt/move NE after 6Z. Guidance hints at another batch of convection
dvlpng across SW MO tonight. This precip, if it dvlps, will move
NE but appears to remain south of the STL metro terminals. Limited
coverage precludes mention attm. SHRA coverage may increase Wed aftn
with the highest coverage expected to be east of the STL metro. Winds
will become wrly Wed mrng.

Specifics for KSTL:

VFR fcst thru the prd though there will be isld/scttrd SHRAs. A weak
bndry will push thru the terminal drng the late mrng allwoing winds
to become more wrly and taking the better chance of rain with it.
Limited coverage precludes mention in the fcst attm.

2%

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  84  66  86 /  40  40  20  20
Quincy          62  80  62  83 /  30  10  10  20
Columbia        62  81  63  84 /  30  30  20  40
Jefferson City  63  81  63  84 /  40  30  20  40
Salem           65  82  65  86 /  30  40  20  20
Farmington      63  82  62  83 /  30  40  30  30

&&

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

$$

WFO LSX







000
FXUS63 KLSX 270500
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1200 AM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 400 PM CDT Tue May 26 2015

The primary forecast issue for tonight is convective trends. A
nearly stacked low pressure system will continue progressing
northeastward towards the Great Lakes tonight, trailing a weak cold
front in its wake. This front will edge into northern MO overnight
before stalling across the region tomorrow. Most models depict a
couple of vorticity maxima rotating into the back side of the
lifting shortwave trough tonight, and the strongest of these
features will provide large-scale ascent across the northern part of
the CWA between 06-12z. Increasing H7-H5 lapse rates spreading
across the region will contribute to instability. There are also
some hints of a H25 jet streak developing across parts of MO which
places the northern CWA beneath the favorable LER. None of these
features by itself looks particularly strong, but taken together
they support a chance of SH/TS accompanying the cold front as it
sinks slowly southward overnight.

One area of uncertainty for tonight is that some models also develop
a southern branch of the LLJ pointed into southwestern MO by 06z.
The models which show a stronger LLJ appear to be developing it as a
response to a vort max lifting out of the southern plains, but it`s
not clear whether that vort max exists in the real atmosphere. On
the other hand, a small thunderstorm complex recently developed over
south-central OK, which is approximately where that feature ought to
be if it does exist. Whether it`s an actual shortwave or just a
remnant MCV, it could provide support for SH/TS given the greater
MUCAPE and better lapse rates which are forecast to be in place over
the southern part of the CWA.

Kanofsky

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 400 PM CDT Tue May 26 2015

In general, short range models are suggesting AMS over the central
CONUS will remain rather unsettled into the end of this week. It
appears that vorticity maxima/shortwaves rotating around the upper
low overnight tonight will exit our area on Wednesday, with
shortwave ridging in the wake of these features advecting into the
mid-Mississippi Valley by Wednesday night.  At this point, not
exactly sure how to handle convective trends on Wednesday;
certainly, primary threat during the morning will be tied to
movement of predawn convection across the CWA. For the afternoon
hours AMS is forecast to destabilize, but aforementioned shortwave
energy will have exited the FA by that time which may tend to
inhibit coverage of any redevelopment, and convergence along the
weak cold front will be rather feeble. I`ve continued some mention
of convection over most of the CWA during the afternoon, with this
threat diminishing and sinking south Wednesday night with the
front, and as upper level ridge builds into the area.

From Thursday into the weekend, southwest flow will dominate the
UA pattern over the central CONUS, with a series of shortwaves
forecast to eject into our area from the longwave trof over the
western U.S. Initially on Thursday, threat will remain in the
chance category as large scale lift is weak and moisture return is
still somewhat limited. However, likely PoPs should overspread
the region Friday-Saturday as there is model consensus that a
fairly robust shortwave and associated cold front will be
impacting the region at this time.

Lesser shower and thunderstorm chances will linger into the start
of the new week as weak ripples continue to propagate through the
area.

Temperatures will remain a bit above average through Friday, then
cool off over the weekend as the colder air works its way into the
mid-Mississippi Valley. For now I`ve pretty much stayed with
guidance that has highs in the 60s to lower 70s on Sunday, but
wonder given the progged upper air patter if this may be a bit too
cool. Will have to monitor upcoming medium range solutions on this
cool down over the next few days and nights.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1140 PM CDT Tue May 26 2015

Isld/scttrd SHRAs will continue to dot the area thru the prd. Weak
forcing along a diffuse bndry will keep sporadic precip percolating.
Current activity across cntrl/NE MO and w cntrl IL should slowly
dsspt/move NE after 6Z. Guidance hints at another batch of convection
dvlpng across SW MO tonight. This precip, if it dvlps, will move
NE but appears to remain south of the STL metro terminals. Limited
coverage precludes mention attm. SHRA coverage may increase Wed aftn
with the highest coverage expected to be east of the STL metro. Winds
will become wrly Wed mrng.

Specifics for KSTL:

VFR fcst thru the prd though there will be isld/scttrd SHRAs. A weak
bndry will push thru the terminal drng the late mrng allwoing winds
to become more wrly and taking the better chance of rain with it.
Limited coverage precludes mention in the fcst attm.

2%

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  84  66  86 /  40  40  20  20
Quincy          62  80  62  83 /  30  10  10  20
Columbia        62  81  63  84 /  30  30  20  40
Jefferson City  63  81  63  84 /  40  30  20  40
Salem           65  82  65  86 /  30  40  20  20
Farmington      63  82  62  83 /  30  40  30  30

&&

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

$$

WFO LSX








000
FXUS63 KLSX 270500
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1200 AM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 400 PM CDT Tue May 26 2015

The primary forecast issue for tonight is convective trends. A
nearly stacked low pressure system will continue progressing
northeastward towards the Great Lakes tonight, trailing a weak cold
front in its wake. This front will edge into northern MO overnight
before stalling across the region tomorrow. Most models depict a
couple of vorticity maxima rotating into the back side of the
lifting shortwave trough tonight, and the strongest of these
features will provide large-scale ascent across the northern part of
the CWA between 06-12z. Increasing H7-H5 lapse rates spreading
across the region will contribute to instability. There are also
some hints of a H25 jet streak developing across parts of MO which
places the northern CWA beneath the favorable LER. None of these
features by itself looks particularly strong, but taken together
they support a chance of SH/TS accompanying the cold front as it
sinks slowly southward overnight.

One area of uncertainty for tonight is that some models also develop
a southern branch of the LLJ pointed into southwestern MO by 06z.
The models which show a stronger LLJ appear to be developing it as a
response to a vort max lifting out of the southern plains, but it`s
not clear whether that vort max exists in the real atmosphere. On
the other hand, a small thunderstorm complex recently developed over
south-central OK, which is approximately where that feature ought to
be if it does exist. Whether it`s an actual shortwave or just a
remnant MCV, it could provide support for SH/TS given the greater
MUCAPE and better lapse rates which are forecast to be in place over
the southern part of the CWA.

Kanofsky

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 400 PM CDT Tue May 26 2015

In general, short range models are suggesting AMS over the central
CONUS will remain rather unsettled into the end of this week. It
appears that vorticity maxima/shortwaves rotating around the upper
low overnight tonight will exit our area on Wednesday, with
shortwave ridging in the wake of these features advecting into the
mid-Mississippi Valley by Wednesday night.  At this point, not
exactly sure how to handle convective trends on Wednesday;
certainly, primary threat during the morning will be tied to
movement of predawn convection across the CWA. For the afternoon
hours AMS is forecast to destabilize, but aforementioned shortwave
energy will have exited the FA by that time which may tend to
inhibit coverage of any redevelopment, and convergence along the
weak cold front will be rather feeble. I`ve continued some mention
of convection over most of the CWA during the afternoon, with this
threat diminishing and sinking south Wednesday night with the
front, and as upper level ridge builds into the area.

From Thursday into the weekend, southwest flow will dominate the
UA pattern over the central CONUS, with a series of shortwaves
forecast to eject into our area from the longwave trof over the
western U.S. Initially on Thursday, threat will remain in the
chance category as large scale lift is weak and moisture return is
still somewhat limited. However, likely PoPs should overspread
the region Friday-Saturday as there is model consensus that a
fairly robust shortwave and associated cold front will be
impacting the region at this time.

Lesser shower and thunderstorm chances will linger into the start
of the new week as weak ripples continue to propagate through the
area.

Temperatures will remain a bit above average through Friday, then
cool off over the weekend as the colder air works its way into the
mid-Mississippi Valley. For now I`ve pretty much stayed with
guidance that has highs in the 60s to lower 70s on Sunday, but
wonder given the progged upper air patter if this may be a bit too
cool. Will have to monitor upcoming medium range solutions on this
cool down over the next few days and nights.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1140 PM CDT Tue May 26 2015

Isld/scttrd SHRAs will continue to dot the area thru the prd. Weak
forcing along a diffuse bndry will keep sporadic precip percolating.
Current activity across cntrl/NE MO and w cntrl IL should slowly
dsspt/move NE after 6Z. Guidance hints at another batch of convection
dvlpng across SW MO tonight. This precip, if it dvlps, will move
NE but appears to remain south of the STL metro terminals. Limited
coverage precludes mention attm. SHRA coverage may increase Wed aftn
with the highest coverage expected to be east of the STL metro. Winds
will become wrly Wed mrng.

Specifics for KSTL:

VFR fcst thru the prd though there will be isld/scttrd SHRAs. A weak
bndry will push thru the terminal drng the late mrng allwoing winds
to become more wrly and taking the better chance of rain with it.
Limited coverage precludes mention in the fcst attm.

2%

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  84  66  86 /  40  40  20  20
Quincy          62  80  62  83 /  30  10  10  20
Columbia        62  81  63  84 /  30  30  20  40
Jefferson City  63  81  63  84 /  40  30  20  40
Salem           65  82  65  86 /  30  40  20  20
Farmington      63  82  62  83 /  30  40  30  30

&&

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

$$

WFO LSX








000
FXUS63 KLSX 270500
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1200 AM CDT Wed May 27 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 400 PM CDT Tue May 26 2015

The primary forecast issue for tonight is convective trends. A
nearly stacked low pressure system will continue progressing
northeastward towards the Great Lakes tonight, trailing a weak cold
front in its wake. This front will edge into northern MO overnight
before stalling across the region tomorrow. Most models depict a
couple of vorticity maxima rotating into the back side of the
lifting shortwave trough tonight, and the strongest of these
features will provide large-scale ascent across the northern part of
the CWA between 06-12z. Increasing H7-H5 lapse rates spreading
across the region will contribute to instability. There are also
some hints of a H25 jet streak developing across parts of MO which
places the northern CWA beneath the favorable LER. None of these
features by itself looks particularly strong, but taken together
they support a chance of SH/TS accompanying the cold front as it
sinks slowly southward overnight.

One area of uncertainty for tonight is that some models also develop
a southern branch of the LLJ pointed into southwestern MO by 06z.
The models which show a stronger LLJ appear to be developing it as a
response to a vort max lifting out of the southern plains, but it`s
not clear whether that vort max exists in the real atmosphere. On
the other hand, a small thunderstorm complex recently developed over
south-central OK, which is approximately where that feature ought to
be if it does exist. Whether it`s an actual shortwave or just a
remnant MCV, it could provide support for SH/TS given the greater
MUCAPE and better lapse rates which are forecast to be in place over
the southern part of the CWA.

Kanofsky

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 400 PM CDT Tue May 26 2015

In general, short range models are suggesting AMS over the central
CONUS will remain rather unsettled into the end of this week. It
appears that vorticity maxima/shortwaves rotating around the upper
low overnight tonight will exit our area on Wednesday, with
shortwave ridging in the wake of these features advecting into the
mid-Mississippi Valley by Wednesday night.  At this point, not
exactly sure how to handle convective trends on Wednesday;
certainly, primary threat during the morning will be tied to
movement of predawn convection across the CWA. For the afternoon
hours AMS is forecast to destabilize, but aforementioned shortwave
energy will have exited the FA by that time which may tend to
inhibit coverage of any redevelopment, and convergence along the
weak cold front will be rather feeble. I`ve continued some mention
of convection over most of the CWA during the afternoon, with this
threat diminishing and sinking south Wednesday night with the
front, and as upper level ridge builds into the area.

From Thursday into the weekend, southwest flow will dominate the
UA pattern over the central CONUS, with a series of shortwaves
forecast to eject into our area from the longwave trof over the
western U.S. Initially on Thursday, threat will remain in the
chance category as large scale lift is weak and moisture return is
still somewhat limited. However, likely PoPs should overspread
the region Friday-Saturday as there is model consensus that a
fairly robust shortwave and associated cold front will be
impacting the region at this time.

Lesser shower and thunderstorm chances will linger into the start
of the new week as weak ripples continue to propagate through the
area.

Temperatures will remain a bit above average through Friday, then
cool off over the weekend as the colder air works its way into the
mid-Mississippi Valley. For now I`ve pretty much stayed with
guidance that has highs in the 60s to lower 70s on Sunday, but
wonder given the progged upper air patter if this may be a bit too
cool. Will have to monitor upcoming medium range solutions on this
cool down over the next few days and nights.

Truett

&&

.AVIATION:  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1140 PM CDT Tue May 26 2015

Isld/scttrd SHRAs will continue to dot the area thru the prd. Weak
forcing along a diffuse bndry will keep sporadic precip percolating.
Current activity across cntrl/NE MO and w cntrl IL should slowly
dsspt/move NE after 6Z. Guidance hints at another batch of convection
dvlpng across SW MO tonight. This precip, if it dvlps, will move
NE but appears to remain south of the STL metro terminals. Limited
coverage precludes mention attm. SHRA coverage may increase Wed aftn
with the highest coverage expected to be east of the STL metro. Winds
will become wrly Wed mrng.

Specifics for KSTL:

VFR fcst thru the prd though there will be isld/scttrd SHRAs. A weak
bndry will push thru the terminal drng the late mrng allwoing winds
to become more wrly and taking the better chance of rain with it.
Limited coverage precludes mention in the fcst attm.

2%

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  84  66  86 /  40  40  20  20
Quincy          62  80  62  83 /  30  10  10  20
Columbia        62  81  63  84 /  30  30  20  40
Jefferson City  63  81  63  84 /  40  30  20  40
Salem           65  82  65  86 /  30  40  20  20
Farmington      63  82  62  83 /  30  40  30  30

&&

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

$$

WFO LSX







000
FXUS63 KLSX 270031
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
731 PM CDT Tue May 26 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 400 PM CDT Tue May 26 2015

The primary forecast issue for tonight is convective trends. A
nearly stacked low pressure system will continue progressing
northeastward towards the Great Lakes tonight, trailing a weak cold
front in its wake. This front will edge into northern MO overnight
before stalling across the region tomorrow. Most models depict a
couple of vorticity maxima rotating into the back side of the
lifting shortwave trough tonight, and the strongest of these
features will provide large-scale ascent across the northern part of
the CWA between 06-12z. Increasing H7-H5 lapse rates spreading
across the region will contribute to instability. There are also
some hints of a H25 jet streak developing across parts of MO which
places the northern CWA beneath the favorable LER. None of these
features by itself looks particularly strong, but taken together
they support a chance of SH/TS accompanying the cold front as it
sinks slowly southward overnight.

One area of uncertainty for tonight is that some models also develop
a southern branch of the LLJ pointed into southwestern MO by 06z.
The models which show a stronger LLJ appear to be developing it as a
response to a vort max lifting out of the southern plains, but it`s
not clear whether that vort max exists in the real atmosphere. On
the other hand, a small thunderstorm complex recently developed over
south-central OK, which is approximately where that feature ought to
be if it does exist. Whether it`s an actual shortwave or just a
remnant MCV, it could provide support for SH/TS given the greater
MUCAPE and better lapse rates which are forecast to be in place over
the southern part of the CWA.

Kanofsky

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 400 PM CDT Tue May 26 2015

In general, short range models are suggesting AMS over the central
CONUS will remain rather unsettled into the end of this week. It
appears that vorticity maxima/shortwaves rotating around the upper
low overnight tonight will exit our area on Wednesday, with
shortwave ridging in the wake of these features advecting into the
mid-Mississippi Valley by Wednesday night.  At this point, not
exactly sure how to handle convective trends on Wednesday;
certainly, primary threat during the morning will be tied to
movement of predawn convection across the CWA. For the afternoon
hours AMS is forecast to destabilize, but aforementioned shortwave
energy will have exited the FA by that time which may tend to
inhibit coverage of any redevelopment, and convergence along the
weak cold front will be rather feeble. I`ve continued some mention
of convection over most of the CWA during the afternoon, with this
threat diminishing and sinking south Wednesday night with the
front, and as upper level ridge builds into the area.

From Thursday into the weekend, southwest flow will dominate the
UA pattern over the central CONUS, with a series of shortwaves
forecast to eject into our area from the longwave trof over the
western U.S. Initially on Thursday, threat will remain in the
chance category as large scale lift is weak and moisture return is
still somewhat limited. However, likely PoPs should overspread
the region Friday-Saturday as there is model consensus that a
fairly robust shortwave and associated cold front will be
impacting the region at this time.

Lesser shower and thunderstorm chances will linger into the start
of the new week as weak ripples continue to propagate through the
area.

Temperatures will remain a bit above average through Friday, then
cool off over the weekend as the colder air works its way into the
mid-Mississippi Valley. For now I`ve pretty much stayed with
guidance that has highs in the 60s to lower 70s on Sunday, but
wonder given the progged upper air patter if this may be a bit too
cool. Will have to monitor upcoming medium range solutions on this
cool down over the next few days and nights.

Truett

&&

.AVIATION:  (For the 00z TAFs through 00z Wednesday Evening)
Issued at 642 PM CDT Tue May 26 2015

Stacked area of low pressure across sthrn MN will lift north
overnight. Isld SHRAs rotating around it across nthrn MO should
diminish after sunset. A weak bndry is progged to slowly sink
south thru the area thru the prd. Expect isld SHRAs in assoc with
this feature overnight. The limited coverage keeps mention of
precip out of the fcst...for now. Coverage may increase some Wedn
aftn but the bndry should be just east of the STL metro sites by
then. Otherwise expect VFR cu and a SW breeze bcmng wrly tomorrow
mrng as the bndry passes.

Specifics for KSTL:

VFR fcst thru the prd. Isld SHRAs are possible tonight in assoc
with a weak bndry slowly sagging south. Due to the expected
limited coverage of the SHRAs, have not included mention of precip
is the TAF attm. Coverage of precip should increase some drng the
aftn but the bndry should be beyond the terminal by that time. The
bndry passes tomorrow mrng swinging the SW wind to the west.

2%

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     66  84  66  86 /  40  40  20  20
Quincy          62  80  62  83 /  30  20  10  20
Columbia        62  81  63  84 /  30  30  20  40
Jefferson City  63  81  63  84 /  40  30  20  40
Salem           65  82  65  86 /  20  40  20  20
Farmington      64  82  62  83 /  20  40  30  30

&&

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

$$

WFO LSX







000
FXUS63 KLSX 262105
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
405 PM CDT Tue May 26 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 400 PM CDT Tue May 26 2015

The primary forecast issue for tonight is convective trends. A
nearly stacked low pressure system will continue progressing
northeastward towards the Great Lakes tonight, trailing a weak cold
front in its wake. This front will edge into northern MO overnight
before stalling across the region tomorrow. Most models depict a
couple of vorticity maxima rotating into the back side of the
lifting shortwave trough tonight, and the strongest of these
features will provide large-scale ascent across the northern part of
the CWA between 06-12z. Increasing H7-H5 lapse rates spreading
across the region will contribute to instability. There are also
some hints of a H25 jet streak developing across parts of MO which
places the northern CWA beneath the favorable LER. None of these
features by itself looks particularly strong, but taken together
they support a chance of SH/TS accompanying the cold front as it
sinks slowly southward overnight.

One area of uncertainty for tonight is that some models also develop
a southern branch of the LLJ pointed into southwestern MO by 06z.
The models which show a stronger LLJ appear to be developing it as a
response to a vort max lifting out of the southern plains, but it`s
not clear whether that vort max exists in the real atmosphere. On
the other hand, a small thunderstorm complex recently developed over
south-central OK, which is approximately where that feature ought to
be if it does exist. Whether it`s an actual shortwave or just a
remnant MCV, it could provide support for SH/TS given the greater
MUCAPE and better lapse rates which are forecast to be in place over
the southern part of the CWA.

Kanofsky

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 400 PM CDT Tue May 26 2015

In general, short range models are suggesting AMS over the central
CONUS will remain rather unsettled into the end of this week. It
appears that vorticity maxima/shortwaves rotating around the upper
low overnight tonight will exit our area on Wednesday, with
shortwave ridging in the wake of these features advecting into the
mid-Mississippi Valley by Wednesday night.  At this point, not
exactly sure how to handle convective trends on Wednesday;
certainly, primary threat during the morning will be tied to
movement of predawn convection across the CWA. For the afternoon
hours AMS is forecast to destabilize, but aforementioned shortwave
energy will have exited the FA by that time which may tend to
inhibit coverage of any redevelopment, and convergence along the
weak cold front will be rather feeble. I`ve continued some mention
of convection over most of the CWA during the afternoon, with this
threat diminishing and sinking south Wednesday night with the
front, and as upper level ridge builds into the area.

From Thursday into the weekend, southwest flow will dominate the
UA pattern over the central CONUS, with a series of shortwaves
forecast to eject into our area from the longwave trof over the
western U.S. Initially on Thursday, threat will remain in the
chance category as large scale lift is weak and moisture return is
still somewhat limited. However, likely PoPs should overspread
the region Friday-Saturday as there is model consensus that a
fairly robust shortwave and associated cold front will be
impacting the region at this time.

Lesser shower and thunderstorm chances will linger into the start
of the new week as weak ripples continue to propagate through the
area.

Temperatures will remain a bit above average through Friday, then
cool off over the weekend as the colder air works its way into the
mid-Mississippi Valley. For now I`ve pretty much stayed with
guidance that has highs in the 60s to lower 70s on Sunday, but
wonder given the progged upper air patter if this may be a bit too
cool. Will have to monitor upcoming medium range solutions on this
cool down over the next few days and nights.

Truett

&&

.AVIATION:  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1156 AM CDT Tue May 26 2015

Specifics for KCOU: Isolated thunderstorms are possible this
afternoon, but the anticipated coverage is too low to include a TS
mention in the TAF attm. Southwest winds will persist through most
of the period with diminishing gusts after sunset.

Specifics for KUIN: A band of showers will have moved through the
terminal before 18z, therefore VCSH was dropped for the initial
TAF issuance. Additional thunderstorms might develop later tonight
near a stalled cold front invof KUIN. Southwest winds will persist
through most of the TAF period.

Specifics for KSTL, KSUS, KCPS: A band of showers has already
developed west of the terminals and should reach the St. Louis
metro area around 19z. Brief periods of MVFR conditions are
possible if one of the showers moves directly over a terminal.
Isolated thunderstorms are possible this afternoon, but the
anticipated coverage is too low to include a TS mention in the
TAFs attm. Southwest winds will persist through most of the period
with diminishing gusts after sunset. Winds at KSTL should become
nearly westerly for several hours after 27/15z, then turn
light/variable just beyond the end of the 30-hr TAF period.

Kanofsky

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     68  84  66  86 /  40  40  20  20
Quincy          63  80  62  83 /  30  20  10  20
Columbia        63  81  63  84 /  30  30  20  40
Jefferson City  64  81  63  84 /  40  30  20  40
Salem           66  82  65  86 /  20  40  20  20
Farmington      64  82  62  83 /  20  40  30  30

&&

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

$$

WFO LSX







000
FXUS63 KLSX 262105
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
405 PM CDT Tue May 26 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 400 PM CDT Tue May 26 2015

The primary forecast issue for tonight is convective trends. A
nearly stacked low pressure system will continue progressing
northeastward towards the Great Lakes tonight, trailing a weak cold
front in its wake. This front will edge into northern MO overnight
before stalling across the region tomorrow. Most models depict a
couple of vorticity maxima rotating into the back side of the
lifting shortwave trough tonight, and the strongest of these
features will provide large-scale ascent across the northern part of
the CWA between 06-12z. Increasing H7-H5 lapse rates spreading
across the region will contribute to instability. There are also
some hints of a H25 jet streak developing across parts of MO which
places the northern CWA beneath the favorable LER. None of these
features by itself looks particularly strong, but taken together
they support a chance of SH/TS accompanying the cold front as it
sinks slowly southward overnight.

One area of uncertainty for tonight is that some models also develop
a southern branch of the LLJ pointed into southwestern MO by 06z.
The models which show a stronger LLJ appear to be developing it as a
response to a vort max lifting out of the southern plains, but it`s
not clear whether that vort max exists in the real atmosphere. On
the other hand, a small thunderstorm complex recently developed over
south-central OK, which is approximately where that feature ought to
be if it does exist. Whether it`s an actual shortwave or just a
remnant MCV, it could provide support for SH/TS given the greater
MUCAPE and better lapse rates which are forecast to be in place over
the southern part of the CWA.

Kanofsky

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 400 PM CDT Tue May 26 2015

In general, short range models are suggesting AMS over the central
CONUS will remain rather unsettled into the end of this week. It
appears that vorticity maxima/shortwaves rotating around the upper
low overnight tonight will exit our area on Wednesday, with
shortwave ridging in the wake of these features advecting into the
mid-Mississippi Valley by Wednesday night.  At this point, not
exactly sure how to handle convective trends on Wednesday;
certainly, primary threat during the morning will be tied to
movement of predawn convection across the CWA. For the afternoon
hours AMS is forecast to destabilize, but aforementioned shortwave
energy will have exited the FA by that time which may tend to
inhibit coverage of any redevelopment, and convergence along the
weak cold front will be rather feeble. I`ve continued some mention
of convection over most of the CWA during the afternoon, with this
threat diminishing and sinking south Wednesday night with the
front, and as upper level ridge builds into the area.

From Thursday into the weekend, southwest flow will dominate the
UA pattern over the central CONUS, with a series of shortwaves
forecast to eject into our area from the longwave trof over the
western U.S. Initially on Thursday, threat will remain in the
chance category as large scale lift is weak and moisture return is
still somewhat limited. However, likely PoPs should overspread
the region Friday-Saturday as there is model consensus that a
fairly robust shortwave and associated cold front will be
impacting the region at this time.

Lesser shower and thunderstorm chances will linger into the start
of the new week as weak ripples continue to propagate through the
area.

Temperatures will remain a bit above average through Friday, then
cool off over the weekend as the colder air works its way into the
mid-Mississippi Valley. For now I`ve pretty much stayed with
guidance that has highs in the 60s to lower 70s on Sunday, but
wonder given the progged upper air patter if this may be a bit too
cool. Will have to monitor upcoming medium range solutions on this
cool down over the next few days and nights.

Truett

&&

.AVIATION:  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1156 AM CDT Tue May 26 2015

Specifics for KCOU: Isolated thunderstorms are possible this
afternoon, but the anticipated coverage is too low to include a TS
mention in the TAF attm. Southwest winds will persist through most
of the period with diminishing gusts after sunset.

Specifics for KUIN: A band of showers will have moved through the
terminal before 18z, therefore VCSH was dropped for the initial
TAF issuance. Additional thunderstorms might develop later tonight
near a stalled cold front invof KUIN. Southwest winds will persist
through most of the TAF period.

Specifics for KSTL, KSUS, KCPS: A band of showers has already
developed west of the terminals and should reach the St. Louis
metro area around 19z. Brief periods of MVFR conditions are
possible if one of the showers moves directly over a terminal.
Isolated thunderstorms are possible this afternoon, but the
anticipated coverage is too low to include a TS mention in the
TAFs attm. Southwest winds will persist through most of the period
with diminishing gusts after sunset. Winds at KSTL should become
nearly westerly for several hours after 27/15z, then turn
light/variable just beyond the end of the 30-hr TAF period.

Kanofsky

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     68  84  66  86 /  40  40  20  20
Quincy          63  80  62  83 /  30  20  10  20
Columbia        63  81  63  84 /  30  30  20  40
Jefferson City  64  81  63  84 /  40  30  20  40
Salem           66  82  65  86 /  20  40  20  20
Farmington      64  82  62  83 /  20  40  30  30

&&

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

$$

WFO LSX








000
FXUS63 KLSX 262105
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
405 PM CDT Tue May 26 2015

.SHORT TERM:  (Through Late Tonight)
Issued at 400 PM CDT Tue May 26 2015

The primary forecast issue for tonight is convective trends. A
nearly stacked low pressure system will continue progressing
northeastward towards the Great Lakes tonight, trailing a weak cold
front in its wake. This front will edge into northern MO overnight
before stalling across the region tomorrow. Most models depict a
couple of vorticity maxima rotating into the back side of the
lifting shortwave trough tonight, and the strongest of these
features will provide large-scale ascent across the northern part of
the CWA between 06-12z. Increasing H7-H5 lapse rates spreading
across the region will contribute to instability. There are also
some hints of a H25 jet streak developing across parts of MO which
places the northern CWA beneath the favorable LER. None of these
features by itself looks particularly strong, but taken together
they support a chance of SH/TS accompanying the cold front as it
sinks slowly southward overnight.

One area of uncertainty for tonight is that some models also develop
a southern branch of the LLJ pointed into southwestern MO by 06z.
The models which show a stronger LLJ appear to be developing it as a
response to a vort max lifting out of the southern plains, but it`s
not clear whether that vort max exists in the real atmosphere. On
the other hand, a small thunderstorm complex recently developed over
south-central OK, which is approximately where that feature ought to
be if it does exist. Whether it`s an actual shortwave or just a
remnant MCV, it could provide support for SH/TS given the greater
MUCAPE and better lapse rates which are forecast to be in place over
the southern part of the CWA.

Kanofsky

.LONG TERM:  (Wednesday through Next Tuesday)
Issued at 400 PM CDT Tue May 26 2015

In general, short range models are suggesting AMS over the central
CONUS will remain rather unsettled into the end of this week. It
appears that vorticity maxima/shortwaves rotating around the upper
low overnight tonight will exit our area on Wednesday, with
shortwave ridging in the wake of these features advecting into the
mid-Mississippi Valley by Wednesday night.  At this point, not
exactly sure how to handle convective trends on Wednesday;
certainly, primary threat during the morning will be tied to
movement of predawn convection across the CWA. For the afternoon
hours AMS is forecast to destabilize, but aforementioned shortwave
energy will have exited the FA by that time which may tend to
inhibit coverage of any redevelopment, and convergence along the
weak cold front will be rather feeble. I`ve continued some mention
of convection over most of the CWA during the afternoon, with this
threat diminishing and sinking south Wednesday night with the
front, and as upper level ridge builds into the area.

From Thursday into the weekend, southwest flow will dominate the
UA pattern over the central CONUS, with a series of shortwaves
forecast to eject into our area from the longwave trof over the
western U.S. Initially on Thursday, threat will remain in the
chance category as large scale lift is weak and moisture return is
still somewhat limited. However, likely PoPs should overspread
the region Friday-Saturday as there is model consensus that a
fairly robust shortwave and associated cold front will be
impacting the region at this time.

Lesser shower and thunderstorm chances will linger into the start
of the new week as weak ripples continue to propagate through the
area.

Temperatures will remain a bit above average through Friday, then
cool off over the weekend as the colder air works its way into the
mid-Mississippi Valley. For now I`ve pretty much stayed with
guidance that has highs in the 60s to lower 70s on Sunday, but
wonder given the progged upper air patter if this may be a bit too
cool. Will have to monitor upcoming medium range solutions on this
cool down over the next few days and nights.

Truett

&&

.AVIATION:  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1156 AM CDT Tue May 26 2015

Specifics for KCOU: Isolated thunderstorms are possible this
afternoon, but the anticipated coverage is too low to include a TS
mention in the TAF attm. Southwest winds will persist through most
of the period with diminishing gusts after sunset.

Specifics for KUIN: A band of showers will have moved through the
terminal before 18z, therefore VCSH was dropped for the initial
TAF issuance. Additional thunderstorms might develop later tonight
near a stalled cold front invof KUIN. Southwest winds will persist
through most of the TAF period.

Specifics for KSTL, KSUS, KCPS: A band of showers has already
developed west of the terminals and should reach the St. Louis
metro area around 19z. Brief periods of MVFR conditions are
possible if one of the showers moves directly over a terminal.
Isolated thunderstorms are possible this afternoon, but the
anticipated coverage is too low to include a TS mention in the
TAFs attm. Southwest winds will persist through most of the period
with diminishing gusts after sunset. Winds at KSTL should become
nearly westerly for several hours after 27/15z, then turn
light/variable just beyond the end of the 30-hr TAF period.

Kanofsky

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     68  84  66  86 /  40  40  20  20
Quincy          63  80  62  83 /  30  20  10  20
Columbia        63  81  63  84 /  30  30  20  40
Jefferson City  64  81  63  84 /  40  30  20  40
Salem           66  82  65  86 /  20  40  20  20
Farmington      64  82  62  83 /  20  40  30  30

&&

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

$$

WFO LSX







000
FXUS63 KLSX 261724
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1224 PM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1156 AM CDT Tue May 26 2015

Specifics for KCOU: Isolated thunderstorms are possible this
afternoon, but the anticipated coverage is too low to include a TS
mention in the TAF attm. Southwest winds will persist through most
of the period with diminishing gusts after sunset.

Specifics for KUIN: A band of showers will have moved through the
terminal before 18z, therefore VCSH was dropped for the initial
TAF issuance. Additional thunderstorms might develop later tonight
near a stalled cold front invof KUIN. Southwest winds will persist
through most of the TAF period.

Specifics for KSTL, KSUS, KCPS: A band of showers has already
developed west of the terminals and should reach the St. Louis
metro area around 19z. Brief periods of MVFR conditions are
possible if one of the showers moves directly over a terminal.
Isolated thunderstorms are possible this afternoon, but the
anticipated coverage is too low to include a TS mention in the
TAFs attm. Southwest winds will persist through most of the period
with diminishing gusts after sunset. Winds at KSTL should become
nearly westerly for several hours after 27/15z, then turn
light/variable just beyond the end of the 30-hr TAF period.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 261724
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1224 PM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1156 AM CDT Tue May 26 2015

Specifics for KCOU: Isolated thunderstorms are possible this
afternoon, but the anticipated coverage is too low to include a TS
mention in the TAF attm. Southwest winds will persist through most
of the period with diminishing gusts after sunset.

Specifics for KUIN: A band of showers will have moved through the
terminal before 18z, therefore VCSH was dropped for the initial
TAF issuance. Additional thunderstorms might develop later tonight
near a stalled cold front invof KUIN. Southwest winds will persist
through most of the TAF period.

Specifics for KSTL, KSUS, KCPS: A band of showers has already
developed west of the terminals and should reach the St. Louis
metro area around 19z. Brief periods of MVFR conditions are
possible if one of the showers moves directly over a terminal.
Isolated thunderstorms are possible this afternoon, but the
anticipated coverage is too low to include a TS mention in the
TAFs attm. Southwest winds will persist through most of the period
with diminishing gusts after sunset. Winds at KSTL should become
nearly westerly for several hours after 27/15z, then turn
light/variable just beyond the end of the 30-hr TAF period.

Kanofsky

&&

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

$$

WFO LSX








000
FXUS63 KLSX 261724
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1224 PM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd

&&

.AVIATION:  (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1156 AM CDT Tue May 26 2015

Specifics for KCOU: Isolated thunderstorms are possible this
afternoon, but the anticipated coverage is too low to include a TS
mention in the TAF attm. Southwest winds will persist through most
of the period with diminishing gusts after sunset.

Specifics for KUIN: A band of showers will have moved through the
terminal before 18z, therefore VCSH was dropped for the initial
TAF issuance. Additional thunderstorms might develop later tonight
near a stalled cold front invof KUIN. Southwest winds will persist
through most of the TAF period.

Specifics for KSTL, KSUS, KCPS: A band of showers has already
developed west of the terminals and should reach the St. Louis
metro area around 19z. Brief periods of MVFR conditions are
possible if one of the showers moves directly over a terminal.
Isolated thunderstorms are possible this afternoon, but the
anticipated coverage is too low to include a TS mention in the
TAFs attm. Southwest winds will persist through most of the period
with diminishing gusts after sunset. Winds at KSTL should become
nearly westerly for several hours after 27/15z, then turn
light/variable just beyond the end of the 30-hr TAF period.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 261203
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
703 AM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Wednesday Morning)
Issued at 701 AM CDT Tue May 26 2015

Showers and isolated thunderstorms are expected to move out of the
terminals by 14Z this morning. MVFR ceilings have recently
redeveloped across Missouri and may linger past 15Z. Expect these
ceilings to lift by late morning and expect mainly dry and VFR
conditions through the rest of the TAF period. Only exception will
be up at KUIN where that terminal will be close enough to a
frontal boundary later this evening that it may see a
thunderstorm when an upper level storm system moves over the area.
MVFR/possibly IFR conditions in moderate-heavy rain would be
possible with any thunderstorms.

Specifics for KSTL: Ceilings have varied low MVFR and VFR during
the night and they are currently around 2000 feet. Expect them to
stay MVFR through 14Z with improvements in the ceilings by late
morning. Otherwise, expect the rest of the TAF period to be mostly
dry and VFR.

Britt

&&

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

$$

WFO LSX








000
FXUS63 KLSX 261203
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
703 AM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Wednesday Morning)
Issued at 701 AM CDT Tue May 26 2015

Showers and isolated thunderstorms are expected to move out of the
terminals by 14Z this morning. MVFR ceilings have recently
redeveloped across Missouri and may linger past 15Z. Expect these
ceilings to lift by late morning and expect mainly dry and VFR
conditions through the rest of the TAF period. Only exception will
be up at KUIN where that terminal will be close enough to a
frontal boundary later this evening that it may see a
thunderstorm when an upper level storm system moves over the area.
MVFR/possibly IFR conditions in moderate-heavy rain would be
possible with any thunderstorms.

Specifics for KSTL: Ceilings have varied low MVFR and VFR during
the night and they are currently around 2000 feet. Expect them to
stay MVFR through 14Z with improvements in the ceilings by late
morning. Otherwise, expect the rest of the TAF period to be mostly
dry and VFR.

Britt

&&

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

$$

WFO LSX








000
FXUS63 KLSX 261203
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
703 AM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Wednesday Morning)
Issued at 701 AM CDT Tue May 26 2015

Showers and isolated thunderstorms are expected to move out of the
terminals by 14Z this morning. MVFR ceilings have recently
redeveloped across Missouri and may linger past 15Z. Expect these
ceilings to lift by late morning and expect mainly dry and VFR
conditions through the rest of the TAF period. Only exception will
be up at KUIN where that terminal will be close enough to a
frontal boundary later this evening that it may see a
thunderstorm when an upper level storm system moves over the area.
MVFR/possibly IFR conditions in moderate-heavy rain would be
possible with any thunderstorms.

Specifics for KSTL: Ceilings have varied low MVFR and VFR during
the night and they are currently around 2000 feet. Expect them to
stay MVFR through 14Z with improvements in the ceilings by late
morning. Otherwise, expect the rest of the TAF period to be mostly
dry and VFR.

Britt

&&

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

$$

WFO LSX







000
FXUS63 KLSX 261203
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
703 AM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd

&&

.AVIATION:  (For the 12z TAFs through 12z Wednesday Morning)
Issued at 701 AM CDT Tue May 26 2015

Showers and isolated thunderstorms are expected to move out of the
terminals by 14Z this morning. MVFR ceilings have recently
redeveloped across Missouri and may linger past 15Z. Expect these
ceilings to lift by late morning and expect mainly dry and VFR
conditions through the rest of the TAF period. Only exception will
be up at KUIN where that terminal will be close enough to a
frontal boundary later this evening that it may see a
thunderstorm when an upper level storm system moves over the area.
MVFR/possibly IFR conditions in moderate-heavy rain would be
possible with any thunderstorms.

Specifics for KSTL: Ceilings have varied low MVFR and VFR during
the night and they are currently around 2000 feet. Expect them to
stay MVFR through 14Z with improvements in the ceilings by late
morning. Otherwise, expect the rest of the TAF period to be mostly
dry and VFR.

Britt

&&

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

$$

WFO LSX







000
FXUS63 KLSX 260847
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
347 AM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1143 PM CDT Mon May 25 2015

Primary concern continues to be the area of rain and thunderstorms
moving northeast through southern Missouri at this time. While the
storms have weakened substantially since 00Z, it does look like
they will roll up along the I-44 corridor through 09Z. Trailing
rain will likely affect areas along and south of I-70 through
sunrise. Some marginal ceilings have developed ahead of the rain
as well, with heights around 2,000 ft. Unsure how the storms will
affect ceilings...they may mix out or reinforce and possibly
lower them. Am leaning toward the former as ceilings back over
southern Missouri are mostly VFR. Thunderstorms will likely
produce brief visibility at or below 3SM in moderate rain. A few
showers and possibly some isolated thunderstorms remain likely
further north as the upper level system associated with the storms
continues to move northeast. Expect VFR flight conditions to
prevail north of the I-70 corridor. VFR conditions are expected to
prevail on Tuesday with gusty south-southwest wind. There is a
chance for more storms in the afternoon...mainly east of the
Mississippi and across portions of northern Missouri.

Specifics for KSTL:

Expect the line of broken storms moving northeast across the
Ozarks to reach the terminal just after 08Z. Some gusty winds and
brief MVFR flight conditions are likely as the line passes. Unsure
if the storms will bring lingering MVFR ceilings or wash the
ceilings out, but am leaning toward the former as ceilings across
southern Missouri behind the line are mainly VFR. VFR conditions
are expected to prevail on Tuesday with gusty south-southwest
wind. There is a chance for more storms in the afternoon...mainly
east of the Mississippi.

Carney
&&

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

$$
WFO LSX







000
FXUS63 KLSX 260847
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
347 AM CDT Tue May 26 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 343 AM CDT Tue May 26 2015

MCV over west central Missouri will continue to lift northward this
morning with activity associated with it sliding north through
region. Coverage is scattered and will see precipitation taper off
from southwest to northeast today. Because of a bit more cloud cover
and precipitation, highs will only be in the upper 70s to low 80s.

Byrd

.LONG TERM:  (Tonight through Monday)
Issued at 343 AM CDT Tue May 26 2015

Tonight through Thursday...

Next in series of weak upper level shortwaves to lift through region
tonight with chances of showers and thunderstorms through early
Thursday. It will not be continuous rain through this period and we
could see a bit of a break on Thursday before next more significant
system approaches for the weekend. Highs will be in the 80s for the
rest of the work week with lows in the 60s.

Friday through Monday...

Deepening upper level trof over the Rockies will begin to slide
towards region on Friday with increasing chances of showers and
thunderstorms for the weekend. Best chances will be Friday night
through Saturday. Cooler air to filter in behind this system with
highs only in the mid 60s to mid 70s by Sunday and Monday.

Byrd
&&

.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1143 PM CDT Mon May 25 2015

Primary concern continues to be the area of rain and thunderstorms
moving northeast through southern Missouri at this time. While the
storms have weakened substantially since 00Z, it does look like
they will roll up along the I-44 corridor through 09Z. Trailing
rain will likely affect areas along and south of I-70 through
sunrise. Some marginal ceilings have developed ahead of the rain
as well, with heights around 2,000 ft. Unsure how the storms will
affect ceilings...they may mix out or reinforce and possibly
lower them. Am leaning toward the former as ceilings back over
southern Missouri are mostly VFR. Thunderstorms will likely
produce brief visibility at or below 3SM in moderate rain. A few
showers and possibly some isolated thunderstorms remain likely
further north as the upper level system associated with the storms
continues to move northeast. Expect VFR flight conditions to
prevail north of the I-70 corridor. VFR conditions are expected to
prevail on Tuesday with gusty south-southwest wind. There is a
chance for more storms in the afternoon...mainly east of the
Mississippi and across portions of northern Missouri.

Specifics for KSTL:

Expect the line of broken storms moving northeast across the
Ozarks to reach the terminal just after 08Z. Some gusty winds and
brief MVFR flight conditions are likely as the line passes. Unsure
if the storms will bring lingering MVFR ceilings or wash the
ceilings out, but am leaning toward the former as ceilings across
southern Missouri behind the line are mainly VFR. VFR conditions
are expected to prevail on Tuesday with gusty south-southwest
wind. There is a chance for more storms in the afternoon...mainly
east of the Mississippi.

Carney
&&

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

$$
WFO LSX






000
FXUS63 KLSX 260501
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1201 AM CDT Tue May 26 2015

.UPDATE:
Issued at 927 PM CDT Mon May 25 2015

An extensive MCS which originated this afternoon across the
southern Plains continues to push eastward into the lower MS
Valley this evening. Large scale ascent associated with the
upstream shortwave trof, ponounced southerly lower trop flow of
moist unstable air, and system relative convergence is helping
maintain the line from AR into Eastern TX, however radar has begun
to show decreasing convective organization on the northern periphery
which is moving more northeastward into MO. This may result in a
diminished severe threat for southern MO. However, the southerly
LLJ is forecast to ramp up and veer later tonight and this combined
with large scale ascent associated with the progressive shortwave
trof and an apparent newd moving MCV presently in NW AR should
maintain a shield of northeast moving showers and thunderstorms.

Glass

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1143 PM CDT Mon May 25 2015

Primary concern continues to be the area of rain and thunderstorms
moving northeast through southern Missouri at this time. While the
storms have weakened substantially since 00Z, it does look like
they will roll up along the I-44 corridor through 09Z. Trailing
rain will likely affect areas along and south of I-70 through
sunrise. Some marginal ceilings have developed ahead of the rain
as well, with heights around 2,000 ft. Unsure how the storms will
affect ceilings...they may mix out or reinforce and possibly
lower them. Am leaning toward the former as ceilings back over
southern Missouri are mostly VFR. Thunderstorms will likely
produce brief visibility at or below 3SM in moderate rain. A few
showers and possibly some isolated thunderstorms remain likely
further north as the upper level system associated with the storms
continues to move northeast. Expect VFR flight conditions to
prevail north of the I-70 corridor. VFR conditions are expected to
prevail on Tuesday with gusty south-southwest wind. There is a
chance for more storms in the afternoon...mainly east of the
Mississippi and across portions of northern Missouri.

Specifics for KSTL:

Expect the line of broken storms moving northeast across the
Ozarks to reach the terminal just after 08Z. Some gusty winds and
brief MVFR flight conditions are likely as the line passes. Unsure
if the storms will bring lingering MVFR ceilings or wash the
ceilings out, but am leaning toward the former as ceilings across
southern Missouri behind the line are mainly VFR. VFR conditions
are expected to prevail on Tuesday with gusty south-southwest
wind. There is a chance for more storms in the afternoon...mainly
east of the Mississippi.

Carney

&&

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

$$

WFO LSX








000
FXUS63 KLSX 260501
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1201 AM CDT Tue May 26 2015

.UPDATE:
Issued at 927 PM CDT Mon May 25 2015

An extensive MCS which originated this afternoon across the
southern Plains continues to push eastward into the lower MS
Valley this evening. Large scale ascent associated with the
upstream shortwave trof, ponounced southerly lower trop flow of
moist unstable air, and system relative convergence is helping
maintain the line from AR into Eastern TX, however radar has begun
to show decreasing convective organization on the northern periphery
which is moving more northeastward into MO. This may result in a
diminished severe threat for southern MO. However, the southerly
LLJ is forecast to ramp up and veer later tonight and this combined
with large scale ascent associated with the progressive shortwave
trof and an apparent newd moving MCV presently in NW AR should
maintain a shield of northeast moving showers and thunderstorms.

Glass

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1143 PM CDT Mon May 25 2015

Primary concern continues to be the area of rain and thunderstorms
moving northeast through southern Missouri at this time. While the
storms have weakened substantially since 00Z, it does look like
they will roll up along the I-44 corridor through 09Z. Trailing
rain will likely affect areas along and south of I-70 through
sunrise. Some marginal ceilings have developed ahead of the rain
as well, with heights around 2,000 ft. Unsure how the storms will
affect ceilings...they may mix out or reinforce and possibly
lower them. Am leaning toward the former as ceilings back over
southern Missouri are mostly VFR. Thunderstorms will likely
produce brief visibility at or below 3SM in moderate rain. A few
showers and possibly some isolated thunderstorms remain likely
further north as the upper level system associated with the storms
continues to move northeast. Expect VFR flight conditions to
prevail north of the I-70 corridor. VFR conditions are expected to
prevail on Tuesday with gusty south-southwest wind. There is a
chance for more storms in the afternoon...mainly east of the
Mississippi and across portions of northern Missouri.

Specifics for KSTL:

Expect the line of broken storms moving northeast across the
Ozarks to reach the terminal just after 08Z. Some gusty winds and
brief MVFR flight conditions are likely as the line passes. Unsure
if the storms will bring lingering MVFR ceilings or wash the
ceilings out, but am leaning toward the former as ceilings across
southern Missouri behind the line are mainly VFR. VFR conditions
are expected to prevail on Tuesday with gusty south-southwest
wind. There is a chance for more storms in the afternoon...mainly
east of the Mississippi.

Carney

&&

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

$$

WFO LSX








000
FXUS63 KLSX 260501
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1201 AM CDT Tue May 26 2015

.UPDATE:
Issued at 927 PM CDT Mon May 25 2015

An extensive MCS which originated this afternoon across the
southern Plains continues to push eastward into the lower MS
Valley this evening. Large scale ascent associated with the
upstream shortwave trof, ponounced southerly lower trop flow of
moist unstable air, and system relative convergence is helping
maintain the line from AR into Eastern TX, however radar has begun
to show decreasing convective organization on the northern periphery
which is moving more northeastward into MO. This may result in a
diminished severe threat for southern MO. However, the southerly
LLJ is forecast to ramp up and veer later tonight and this combined
with large scale ascent associated with the progressive shortwave
trof and an apparent newd moving MCV presently in NW AR should
maintain a shield of northeast moving showers and thunderstorms.

Glass

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1143 PM CDT Mon May 25 2015

Primary concern continues to be the area of rain and thunderstorms
moving northeast through southern Missouri at this time. While the
storms have weakened substantially since 00Z, it does look like
they will roll up along the I-44 corridor through 09Z. Trailing
rain will likely affect areas along and south of I-70 through
sunrise. Some marginal ceilings have developed ahead of the rain
as well, with heights around 2,000 ft. Unsure how the storms will
affect ceilings...they may mix out or reinforce and possibly
lower them. Am leaning toward the former as ceilings back over
southern Missouri are mostly VFR. Thunderstorms will likely
produce brief visibility at or below 3SM in moderate rain. A few
showers and possibly some isolated thunderstorms remain likely
further north as the upper level system associated with the storms
continues to move northeast. Expect VFR flight conditions to
prevail north of the I-70 corridor. VFR conditions are expected to
prevail on Tuesday with gusty south-southwest wind. There is a
chance for more storms in the afternoon...mainly east of the
Mississippi and across portions of northern Missouri.

Specifics for KSTL:

Expect the line of broken storms moving northeast across the
Ozarks to reach the terminal just after 08Z. Some gusty winds and
brief MVFR flight conditions are likely as the line passes. Unsure
if the storms will bring lingering MVFR ceilings or wash the
ceilings out, but am leaning toward the former as ceilings across
southern Missouri behind the line are mainly VFR. VFR conditions
are expected to prevail on Tuesday with gusty south-southwest
wind. There is a chance for more storms in the afternoon...mainly
east of the Mississippi.

Carney

&&

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

$$

WFO LSX







000
FXUS63 KLSX 260501
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1201 AM CDT Tue May 26 2015

.UPDATE:
Issued at 927 PM CDT Mon May 25 2015

An extensive MCS which originated this afternoon across the
southern Plains continues to push eastward into the lower MS
Valley this evening. Large scale ascent associated with the
upstream shortwave trof, ponounced southerly lower trop flow of
moist unstable air, and system relative convergence is helping
maintain the line from AR into Eastern TX, however radar has begun
to show decreasing convective organization on the northern periphery
which is moving more northeastward into MO. This may result in a
diminished severe threat for southern MO. However, the southerly
LLJ is forecast to ramp up and veer later tonight and this combined
with large scale ascent associated with the progressive shortwave
trof and an apparent newd moving MCV presently in NW AR should
maintain a shield of northeast moving showers and thunderstorms.

Glass

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1143 PM CDT Mon May 25 2015

Primary concern continues to be the area of rain and thunderstorms
moving northeast through southern Missouri at this time. While the
storms have weakened substantially since 00Z, it does look like
they will roll up along the I-44 corridor through 09Z. Trailing
rain will likely affect areas along and south of I-70 through
sunrise. Some marginal ceilings have developed ahead of the rain
as well, with heights around 2,000 ft. Unsure how the storms will
affect ceilings...they may mix out or reinforce and possibly
lower them. Am leaning toward the former as ceilings back over
southern Missouri are mostly VFR. Thunderstorms will likely
produce brief visibility at or below 3SM in moderate rain. A few
showers and possibly some isolated thunderstorms remain likely
further north as the upper level system associated with the storms
continues to move northeast. Expect VFR flight conditions to
prevail north of the I-70 corridor. VFR conditions are expected to
prevail on Tuesday with gusty south-southwest wind. There is a
chance for more storms in the afternoon...mainly east of the
Mississippi and across portions of northern Missouri.

Specifics for KSTL:

Expect the line of broken storms moving northeast across the
Ozarks to reach the terminal just after 08Z. Some gusty winds and
brief MVFR flight conditions are likely as the line passes. Unsure
if the storms will bring lingering MVFR ceilings or wash the
ceilings out, but am leaning toward the former as ceilings across
southern Missouri behind the line are mainly VFR. VFR conditions
are expected to prevail on Tuesday with gusty south-southwest
wind. There is a chance for more storms in the afternoon...mainly
east of the Mississippi.

Carney

&&

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

$$

WFO LSX







000
FXUS63 KLSX 260244
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
944 PM CDT Mon May 25 2015

.UPDATE:
Issued at 927 PM CDT Mon May 25 2015

An extensive MCS which originated this afternoon across the
southern Plains continues to push eastward into the lower MS
Valley this evening. Large scale ascent associated with the
upstream shortwave trof, ponounced southerly lower trop flow of
moist unstable air, and system relative convergence is helping
maintain the line from AR into Eastern TX, however radar has begun
to show decreasing convective organization on the northern periphery
which is moving more northeastward into MO. This may result in a
diminished severe threat for southern MO. However, the southerly
LLJ is forecast to ramp up and veer later tonight and this combined
with large scale ascent associated with the progressive shortwave
trof and an apparent newd moving MCV presently in NW AR should
maintain a shield of northeast moving showers and thunderstorms.

Glass

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 636 PM CDT Mon May 25 2015

Primary concern for tonight is the large thunderstorm complex
currently moving northeast out of Oklahoma into northwest
Arkansas. The upper level disturbance associated with the storms
will move over our area after 05-06Z tonight. Am fairly certain
there will be rain and thunderstorms associated with the
disturbance as it moves across the area, but am less certain about
the strength, and areal coverage in thunderstorms. This
uncertainty is the primary reason the TAFs have prevailing showers
with vicinity thunder. Will continue to monitor the convection as
it moves into Missouri later this evening and adjust TAFs as
needed. Otherwise...expect VFR flight conditions ahead of the
rain, with ceilings falling to MVFR after the rain begins. If
storms can stay strong through the night, IFR visibility in
intermittent heavy rain is possible. Forecast for Tuesday is
uncertain as well, as warm moist and unstable air will persist
behind the early morning rain. Current thinking is that widely
scattered to scattered thunderstorms will be possible, mainly east
of the Mississippi River...but this could change depending on what
happens with the storms tonight.

Specifics for KSTL:

VFR flight conditions are expected to prevail at Lambert at least
through the evening and for a few hours after 06Z.  Primary
concern for tonight is the large thunderstorm complex currently
moving northeast out of Oklahoma into northwest Arkansas. The
upper level disturbance associated with the storms will move over
our area after 05-06Z tonight. Am fairly certain there will be
rain and thunderstorms associated with the disturbance, but am
less certain about the strength, and areal coverage in
thunderstorms. This uncertainty is the primary reason the Lambert
TAF has prevailing showers with vicinity thunder. Will continue
to monitor the convection as it moves into Missouri later this
evening and adjust TAFs as needed. If storms can stay strong
through the night, IFR visibility in intermittent heavy rain is
possible. Forecast for Tuesday is uncertain as well, as warm moist
and unstable air will persist behind the early morning rain.
Current thinking is that widely scattered to scattered
thunderstorms will be possible, mainly east of the Mississippi
River...but this could change depending on what happens with the
storms tonight.

Carney

&&

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

$$

WFO LSX








000
FXUS63 KLSX 260244
AFDLSX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ST LOUIS MO
944 PM CDT Mon May 25 2015

.UPDATE:
Issued at 927 PM CDT Mon May 25 2015

An extensive MCS which originated this afternoon across the
southern Plains continues to push eastward into the lower MS
Valley this evening. Large scale ascent associated with the
upstream shortwave trof, ponounced southerly lower trop flow of
moist unstable air, and system relative convergence is helping
maintain the line from AR into Eastern TX, however radar has begun
to show decreasing convective organization on the northern periphery
which is moving more northeastward into MO. This may result in a
diminished severe threat for southern MO. However, the southerly
LLJ is forecast to ramp up and veer later tonight and this combined
with large scale ascent associated with the progressive shortwave
trof and an apparent newd moving MCV presently in NW AR should
maintain a shield of northeast moving showers and thunderstorms.

Glass

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 636 PM CDT Mon May 25 2015

Primary concern for tonight is the large thunderstorm complex
currently moving northeast out of Oklahoma into northwest
Arkansas. The upper level disturbance associated with the storms
will move over our area after 05-06Z tonight. Am fairly certain
there will be rain and thunderstorms associated with the
disturbance as it moves across the area, but am less certain about
the strength, and areal coverage in thunderstorms. This
uncertainty is the primary reason the TAFs have prevailing showers
with vicinity thunder. Will continue to monitor the convection as
it moves into Missouri later this evening and adjust TAFs as
needed. Otherwise...expect VFR flight conditions ahead of the
rain, with ceilings falling to MVFR after the rain begins. If
storms can stay strong through the night, IFR visibility in
intermittent heavy rain is possible. Forecast for Tuesday is
uncertain as well, as warm moist and unstable air will persist
behind the early morning rain. Current thinking is that widely
scattered to scattered thunderstorms will be possible, mainly east
of the Mississippi River...but this could change depending on what
happens with the storms tonight.

Specifics for KSTL:

VFR flight conditions are expected to prevail at Lambert at least
through the evening and for a few hours after 06Z.  Primary
concern for tonight is the large thunderstorm complex currently
moving northeast out of Oklahoma into northwest Arkansas. The
upper level disturbance associated with the storms will move over
our area after 05-06Z tonight. Am fairly certain there will be
rain and thunderstorms associated with the disturbance, but am
less certain about the strength, and areal coverage in
thunderstorms. This uncertainty is the primary reason the Lambert
TAF has prevailing showers with vicinity thunder. Will continue
to monitor the convection as it moves into Missouri later this
evening and adjust TAFs as needed. If storms can stay strong
through the night, IFR visibility in intermittent heavy rain is
possible. Forecast for Tuesday is uncertain as well, as warm moist
and unstable air will persist behind the early morning rain.
Current thinking is that widely scattered to scattered
thunderstorms will be possible, mainly east of the Mississippi
River...but this could change depending on what happens with the
storms tonight.

Carney

&&

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

$$

WFO LSX







000
FXUS63 KLSX 260001
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
701 PM CDT Mon May 25 2015

.SYNOPSIS:
Issued at 236 PM CDT Mon May 25 2015

Relatively quiet Memorial Day across the area in the wake of
yesterdays thunderstorms with temperatures warming into the lower
and middle 80s. Meanwhile, a wicked MCS is currently churning
across northern Texas and southern Oklahoma and is associated
with the next significant shortwave that will lift northeast
toward our region tonight.

CVKING

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 636 PM CDT Mon May 25 2015

Primary concern for tonight is the large thunderstorm complex
currently moving northeast out of Oklahoma into northwest
Arkansas. The upper level disturbance associated with the storms
will move over our area after 05-06Z tonight. Am fairly certain
there will be rain and thunderstorms associated with the
disturbance as it moves across the area, but am less certain about
the strength, and areal coverage in thunderstorms. This
uncertainty is the primary reason the TAFs have prevailing showers
with vicinity thunder. Will continue to monitor the convection as
it moves into Missouri later this evening and adjust TAFs as
needed. Otherwise...expect VFR flight conditions ahead of the
rain, with ceilings falling to MVFR after the rain begins. If
storms can stay strong through the night, IFR visibility in
intermittent heavy rain is possible. Forecast for Tuesday is
uncertain as well, as warm moist and unstable air will persist
behind the early morning rain. Current thinking is that widely
scattered to scattered thunderstorms will be possible, mainly east
of the Mississippi River...but this could change depending on what
happens with the storms tonight.

Specifics for KSTL:

VFR flight conditions are expected to prevail at Lambert at least
through the evening and for a few hours after 06Z.  Primary
concern for tonight is the large thunderstorm complex currently
moving northeast out of Oklahoma into northwest Arkansas. The
upper level disturbance associated with the storms will move over
our area after 05-06Z tonight. Am fairly certain there will be
rain and thunderstorms associated with the disturbance, but am
less certain about the strength, and areal coverage in
thunderstorms. This uncertainty is the primary reason the Lambert
TAF has prevailing showers with vicinity thunder. Will continue
to monitor the convection as it moves into Missouri later this
evening and adjust TAFs as needed. If storms can stay strong
through the night, IFR visibility in intermittent heavy rain is
possible. Forecast for Tuesday is uncertain as well, as warm moist
and unstable air will persist behind the early morning rain.
Current thinking is that widely scattered to scattered
thunderstorms will be possible, mainly east of the Mississippi
River...but this could change depending on what happens with the
storms tonight.

Carney

&&

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

$$

WFO LSX








000
FXUS63 KLSX 260001
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
701 PM CDT Mon May 25 2015

.SYNOPSIS:
Issued at 236 PM CDT Mon May 25 2015

Relatively quiet Memorial Day across the area in the wake of
yesterdays thunderstorms with temperatures warming into the lower
and middle 80s. Meanwhile, a wicked MCS is currently churning
across northern Texas and southern Oklahoma and is associated
with the next significant shortwave that will lift northeast
toward our region tonight.

CVKING

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 636 PM CDT Mon May 25 2015

Primary concern for tonight is the large thunderstorm complex
currently moving northeast out of Oklahoma into northwest
Arkansas. The upper level disturbance associated with the storms
will move over our area after 05-06Z tonight. Am fairly certain
there will be rain and thunderstorms associated with the
disturbance as it moves across the area, but am less certain about
the strength, and areal coverage in thunderstorms. This
uncertainty is the primary reason the TAFs have prevailing showers
with vicinity thunder. Will continue to monitor the convection as
it moves into Missouri later this evening and adjust TAFs as
needed. Otherwise...expect VFR flight conditions ahead of the
rain, with ceilings falling to MVFR after the rain begins. If
storms can stay strong through the night, IFR visibility in
intermittent heavy rain is possible. Forecast for Tuesday is
uncertain as well, as warm moist and unstable air will persist
behind the early morning rain. Current thinking is that widely
scattered to scattered thunderstorms will be possible, mainly east
of the Mississippi River...but this could change depending on what
happens with the storms tonight.

Specifics for KSTL:

VFR flight conditions are expected to prevail at Lambert at least
through the evening and for a few hours after 06Z.  Primary
concern for tonight is the large thunderstorm complex currently
moving northeast out of Oklahoma into northwest Arkansas. The
upper level disturbance associated with the storms will move over
our area after 05-06Z tonight. Am fairly certain there will be
rain and thunderstorms associated with the disturbance, but am
less certain about the strength, and areal coverage in
thunderstorms. This uncertainty is the primary reason the Lambert
TAF has prevailing showers with vicinity thunder. Will continue
to monitor the convection as it moves into Missouri later this
evening and adjust TAFs as needed. If storms can stay strong
through the night, IFR visibility in intermittent heavy rain is
possible. Forecast for Tuesday is uncertain as well, as warm moist
and unstable air will persist behind the early morning rain.
Current thinking is that widely scattered to scattered
thunderstorms will be possible, mainly east of the Mississippi
River...but this could change depending on what happens with the
storms tonight.

Carney

&&

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

$$

WFO LSX







000
FXUS63 KLSX 260001
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
701 PM CDT Mon May 25 2015

.SYNOPSIS:
Issued at 236 PM CDT Mon May 25 2015

Relatively quiet Memorial Day across the area in the wake of
yesterdays thunderstorms with temperatures warming into the lower
and middle 80s. Meanwhile, a wicked MCS is currently churning
across northern Texas and southern Oklahoma and is associated
with the next significant shortwave that will lift northeast
toward our region tonight.

CVKING

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 636 PM CDT Mon May 25 2015

Primary concern for tonight is the large thunderstorm complex
currently moving northeast out of Oklahoma into northwest
Arkansas. The upper level disturbance associated with the storms
will move over our area after 05-06Z tonight. Am fairly certain
there will be rain and thunderstorms associated with the
disturbance as it moves across the area, but am less certain about
the strength, and areal coverage in thunderstorms. This
uncertainty is the primary reason the TAFs have prevailing showers
with vicinity thunder. Will continue to monitor the convection as
it moves into Missouri later this evening and adjust TAFs as
needed. Otherwise...expect VFR flight conditions ahead of the
rain, with ceilings falling to MVFR after the rain begins. If
storms can stay strong through the night, IFR visibility in
intermittent heavy rain is possible. Forecast for Tuesday is
uncertain as well, as warm moist and unstable air will persist
behind the early morning rain. Current thinking is that widely
scattered to scattered thunderstorms will be possible, mainly east
of the Mississippi River...but this could change depending on what
happens with the storms tonight.

Specifics for KSTL:

VFR flight conditions are expected to prevail at Lambert at least
through the evening and for a few hours after 06Z.  Primary
concern for tonight is the large thunderstorm complex currently
moving northeast out of Oklahoma into northwest Arkansas. The
upper level disturbance associated with the storms will move over
our area after 05-06Z tonight. Am fairly certain there will be
rain and thunderstorms associated with the disturbance, but am
less certain about the strength, and areal coverage in
thunderstorms. This uncertainty is the primary reason the Lambert
TAF has prevailing showers with vicinity thunder. Will continue
to monitor the convection as it moves into Missouri later this
evening and adjust TAFs as needed. If storms can stay strong
through the night, IFR visibility in intermittent heavy rain is
possible. Forecast for Tuesday is uncertain as well, as warm moist
and unstable air will persist behind the early morning rain.
Current thinking is that widely scattered to scattered
thunderstorms will be possible, mainly east of the Mississippi
River...but this could change depending on what happens with the
storms tonight.

Carney

&&

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

$$

WFO LSX








000
FXUS63 KLSX 260001
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
701 PM CDT Mon May 25 2015

.SYNOPSIS:
Issued at 236 PM CDT Mon May 25 2015

Relatively quiet Memorial Day across the area in the wake of
yesterdays thunderstorms with temperatures warming into the lower
and middle 80s. Meanwhile, a wicked MCS is currently churning
across northern Texas and southern Oklahoma and is associated
with the next significant shortwave that will lift northeast
toward our region tonight.

CVKING

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 636 PM CDT Mon May 25 2015

Primary concern for tonight is the large thunderstorm complex
currently moving northeast out of Oklahoma into northwest
Arkansas. The upper level disturbance associated with the storms
will move over our area after 05-06Z tonight. Am fairly certain
there will be rain and thunderstorms associated with the
disturbance as it moves across the area, but am less certain about
the strength, and areal coverage in thunderstorms. This
uncertainty is the primary reason the TAFs have prevailing showers
with vicinity thunder. Will continue to monitor the convection as
it moves into Missouri later this evening and adjust TAFs as
needed. Otherwise...expect VFR flight conditions ahead of the
rain, with ceilings falling to MVFR after the rain begins. If
storms can stay strong through the night, IFR visibility in
intermittent heavy rain is possible. Forecast for Tuesday is
uncertain as well, as warm moist and unstable air will persist
behind the early morning rain. Current thinking is that widely
scattered to scattered thunderstorms will be possible, mainly east
of the Mississippi River...but this could change depending on what
happens with the storms tonight.

Specifics for KSTL:

VFR flight conditions are expected to prevail at Lambert at least
through the evening and for a few hours after 06Z.  Primary
concern for tonight is the large thunderstorm complex currently
moving northeast out of Oklahoma into northwest Arkansas. The
upper level disturbance associated with the storms will move over
our area after 05-06Z tonight. Am fairly certain there will be
rain and thunderstorms associated with the disturbance, but am
less certain about the strength, and areal coverage in
thunderstorms. This uncertainty is the primary reason the Lambert
TAF has prevailing showers with vicinity thunder. Will continue
to monitor the convection as it moves into Missouri later this
evening and adjust TAFs as needed. If storms can stay strong
through the night, IFR visibility in intermittent heavy rain is
possible. Forecast for Tuesday is uncertain as well, as warm moist
and unstable air will persist behind the early morning rain.
Current thinking is that widely scattered to scattered
thunderstorms will be possible, mainly east of the Mississippi
River...but this could change depending on what happens with the
storms tonight.

Carney

&&

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

$$

WFO LSX







000
FXUS63 KLSX 251939
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
239 PM CDT Mon May 25 2015

.SYNOPSIS:
Issued at 236 PM CDT Mon May 25 2015

Relatively quiet Memorial Day across the area in the wake of
yesterdays thunderstorms with temperatures warming into the lower
and middle 80s. Meanwhile, a wicked MCS is currently churning
across northern Texas and southern Oklahoma and is associated
with the next significant shortwave that will lift northeast
toward our region tonight.

CVKING

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1225 PM CDT Mon May 25 2015

VFR conditions are expected to prevail at all TAF sites this
afternoon and into the evening hours unless a rogue thunderstorm
develops and happens to move directly over one of the terminals.
The chance of afternoon TSRA appears to be higher at
KCOU/KSTL/KSUS/KCPS than at KUIN due to those sites` proximity to
an outflow boundary which moved into the region earlier this
morning. A period of rain showers with embedded thunderstorms is
expected to lift northeastward and affect all terminals late
tonight and tomorrow morning. MVFR cigs and precipitation are
expected to reach KCOU around 06-09z, KSTL/KSUS/KCPS around
08-11z, and KUIN around 10-13z. Initially southwesterly winds will
gradually back and become more southerly or southeasterly today
and tonight, then become southwesterly again towards the end of
the valid TAF period.

Kanofsky

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     71  81  70  83 /  80  70  20  50
Quincy          65  79  63  80 /  70  70  20  30
Columbia        64  80  64  80 /  80  50  30  40
Jefferson City  65  81  65  81 /  80  50  30  40
Salem           68  78  68  83 /  50  70  20  50
Farmington      65  78  64  81 /  80  60  20  50

&&

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

$$

WFO LSX






000
FXUS63 KLSX 251939
AFDLSX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
239 PM CDT Mon May 25 2015

.SYNOPSIS:
Issued at 236 PM CDT Mon May 25 2015

Relatively quiet Memorial Day across the area in the wake of
yesterdays thunderstorms with temperatures warming into the lower
and middle 80s. Meanwhile, a wicked MCS is currently churning
across northern Texas and southern Oklahoma and is associated
with the next significant shortwave that will lift northeast
toward our region tonight.

CVKING

&&

.SHORT TERM: (Tonight through Thursday)
Issued at 236 PM CDT Mon May 25 2015

Expect quiet weather to continue for any remaining holiday
festivities this evening, with the anticipation that the northern
portion of the aforementioned MCS, likely in a decaying phase,
will be entering our southwestern counties shortly after midnight.
Large scale ascent with the shortwave should initiate additional
convection further north as well with the entire area moving
northeast through the remainder of the CWA through daybreak on
Tuesday. Not sure how much redevelopment will be able to occur
Tuesday afternoon in the wake of the morning rain. Have lowered
PoPs from west to east Tuesday afternoon.

Have chance PoPs continuing Tuesday night through Thursday as a
series of weaker shortwaves are forecast to impact the area as the
upper level pattern temporarily becomes a little more zonal.

CVKING

.LONG TERM: (Next Weekend)
Issued at 236 PM CDT Mon May 25 2015

Thunderstorm chances will steadily increase as the upper trough will
deepen again to our west by the end of the work week and actually
progress east into the middle Mississippi River Valley by the end of
the weekend. Temperatures will remain near normal for the end of May.

CVKING

&&

.AVIATION:  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1225 PM CDT Mon May 25 2015

VFR conditions are expected to prevail at all TAF sites this
afternoon and into the evening hours unless a rogue thunderstorm
develops and happens to move directly over one of the terminals.
The chance of afternoon TSRA appears to be higher at
KCOU/KSTL/KSUS/KCPS than at KUIN due to those sites` proximity to
an outflow boundary which moved into the region earlier this
morning. A period of rain showers with embedded thunderstorms is
expected to lift northeastward and affect all terminals late
tonight and tomorrow morning. MVFR cigs and precipitation are
expected to reach KCOU around 06-09z, KSTL/KSUS/KCPS around
08-11z, and KUIN around 10-13z. Initially southwesterly winds will
gradually back and become more southerly or southeasterly today
and tonight, then become southwesterly again towards the end of
the valid TAF period.

Kanofsky

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     71  81  70  83 /  80  70  20  50
Quincy          65  79  63  80 /  70  70  20  30
Columbia        64  80  64  80 /  80  50  30  40
Jefferson City  65  81  65  81 /  80  50  30  40
Salem           68  78  68  83 /  50  70  20  50
Farmington      65  78  64  81 /  80  60  20  50

&&

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

$$

WFO LSX





000
FXUS63 KLSX 251740
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1240 PM CDT Mon May 25 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 338 AM CDT Mon May 25 2015

Area of showers currently over west central Missouri will move
northeast and will affect some of the northeast Missouri counties
before 9 am ahead of the mid level shortwave that will move out of
the area by mid-morning. Otherwise, expect a drier day today as
area will lie under subsidence in the wake of the shortwave
trough. Only exception will be over parts of central and southeast
Missouri into southern Illinois where the atmosphere will become
unstable which could still lead to a few showers and thunderstorms
developing during the afternoon hours. High temperatures this
afternoon will be close to what they were on Sunday, which were in
the lower-mid 80s.

Britt

.LONG TERM:  (Tonight through Sunday)
Issued at 338 AM CDT Mon May 25 2015

(Tonight through Wednesday)

Will continue to follow the NAM/ECMWF which has had the best
continuity as of late.  Have kept with current trends on PoPs
tonight into Tuesday.  A shortwave ridge will move off to the east
of the area tonight which will allow for a rapid increase in ascent
after 06Z caused by the approach the next mid-level trough and
increasing low-level moisture convergence.  Will keep likely PoPs
over much of the southern half of the CWA of the area after midnight
tonight, and continue them into Tuesday morning as the mid-
level trough moves through before the showers and thunderstorms
become scattered during the afternoon.  The chance of thunderstorms
will continue Tuesday night into Wednesday as another weak shortwave
moves across the area.

(Thursday through next Sunday)

Rain chances will continue into the extended part of the forecast as
upper trough over western CONUS moves into the Great Plains and
eventually through Middle Mississippi Valley by next Sunday.  ECMWF
shows a series of shortwave troughs with attendant low level
moisture convergence moving through the area ahead of this main
trough.  This is worth keeping a chance of showers and thunderstorms
in each day with the best chance on Saturday when ECMWF currently
shows a cold front moving through.  Temperatures will stay close to
normal with 850mb temperatures in the 10-15C range.

Britt

&&

.AVIATION:  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1225 PM CDT Mon May 25 2015

VFR conditions are expected to prevail at all TAF sites this
afternoon and into the evening hours unless a rogue thunderstorm
develops and happens to move directly over one of the terminals.
The chance of afternoon TSRA appears to be higher at
KCOU/KSTL/KSUS/KCPS than at KUIN due to those sites` proximity to
an outflow boundary which moved into the region earlier this
morning. A period of rain showers with embedded thunderstorms is
expected to lift northeastward and affect all terminals late
tonight and tomorrow morning. MVFR cigs and precipitation are
expected to reach KCOU around 06-09z, KSTL/KSUS/KCPS around
08-11z, and KUIN around 10-13z. Initially southwesterly winds will
gradually back and become more southerly or southeasterly today
and tonight, then become southwesterly again towards the end of
the valid TAF period.

Kanofsky

&&

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

$$

WFO LSX







000
FXUS63 KLSX 251740
AFDLSX

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1240 PM CDT Mon May 25 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 338 AM CDT Mon May 25 2015

Area of showers currently over west central Missouri will move
northeast and will affect some of the northeast Missouri counties
before 9 am ahead of the mid level shortwave that will move out of
the area by mid-morning. Otherwise, expect a drier day today as
area will lie under subsidence in the wake of the shortwave
trough. Only exception will be over parts of central and southeast
Missouri into southern Illinois where the atmosphere will become
unstable which could still lead to a few showers and thunderstorms
developing during the afternoon hours. High temperatures this
afternoon will be close to what they were on Sunday, which were in
the lower-mid 80s.

Britt

.LONG TERM:  (Tonight through Sunday)
Issued at 338 AM CDT Mon May 25 2015

(Tonight through Wednesday)

Will continue to follow the NAM/ECMWF which has had the best
continuity as of late.  Have kept with current trends on PoPs
tonight into Tuesday.  A shortwave ridge will move off to the east
of the area tonight which will allow for a rapid increase in ascent
after 06Z caused by the approach the next mid-level trough and
increasing low-level moisture convergence.  Will keep likely PoPs
over much of the southern half of the CWA of the area after midnight
tonight, and continue them into Tuesday morning as the mid-
level trough moves through before the showers and thunderstorms
become scattered during the afternoon.  The chance of thunderstorms
will continue Tuesday night into Wednesday as another weak shortwave
moves across the area.

(Thursday through next Sunday)

Rain chances will continue into the extended part of the forecast as
upper trough over western CONUS moves into the Great Plains and
eventually through Middle Mississippi Valley by next Sunday.  ECMWF
shows a series of shortwave troughs with attendant low level
moisture convergence moving through the area ahead of this main
trough.  This is worth keeping a chance of showers and thunderstorms
in each day with the best chance on Saturday when ECMWF currently
shows a cold front moving through.  Temperatures will stay close to
normal with 850mb temperatures in the 10-15C range.

Britt

&&

.AVIATION:  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1225 PM CDT Mon May 25 2015

VFR conditions are expected to prevail at all TAF sites this
afternoon and into the evening hours unless a rogue thunderstorm
develops and happens to move directly over one of the terminals.
The chance of afternoon TSRA appears to be higher at
KCOU/KSTL/KSUS/KCPS than at KUIN due to those sites` proximity to
an outflow boundary which moved into the region earlier this
morning. A period of rain showers with embedded thunderstorms is
expected to lift northeastward and affect all terminals late
tonight and tomorrow morning. MVFR cigs and precipitation are
expected to reach KCOU around 06-09z, KSTL/KSUS/KCPS around
08-11z, and KUIN around 10-13z. Initially southwesterly winds will
gradually back and become more southerly or southeasterly today
and tonight, then become southwesterly again towards the end of
the valid TAF period.

Kanofsky

&&

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

$$

WFO LSX








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