Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 230843

Area Forecast Discussion
National Weather Service Saint Louis MO
343 AM CDT Sun Oct 23 2016

.SHORT TERM...  (Through Late Tonight)
Issued at 343 AM CDT Sun Oct 23 2016

As surface ridge continues to slide off to the southeast today, next
cold front to begin sliding through this afternoon. In the meantime,
with decent gradient between the ridge and cold front, gusty south
to southwest winds will help temperatures to rise into the mid to
upper 70s under sunny skies.

With little in the way of moisture associated with cold front, it
will slide through dry late this afternoon before exiting forecast
area this evening. Only indication of frontal passage will be winds
shifting to the northwest to north and diminishing. Not a lot of
cold air behind this front, so will see lows near normal in the low
40s far north to the upper 40s south tonight.


.LONG TERM...  (Monday through Saturday)
Issued at 343 AM CDT Sun Oct 23 2016

The effective cold front should be up across northern Missouri
stretching into northwest Illinois.  The front will push south
overnight and should be through the CWFA down to near the
Missouri/Arkansas-Kentucky/Tennessee border by sunrise on Monday.  A
ridge of high pressure stuck over the Gulf Coast will block any
decent moisture return ahead of the front, so the FROPA still looks
dry.  The low level thermal gradient behind the front looks like it
will set up from Columbia northeast across the Mississippi River
with warmest readings out in central and southwest Missouri.  For
most of our CWFA , this should be another little shot of Fall
with temperatures falling back to near or a few degees below normal.
Much of central and southern Missouri will probably remain a few
degrees warmer though.

The surface ridge behind the front will build across the eastern 1/3
of the CONUS and south-southeast flow will prevail through Tuesday
night ahead of the next shortwave.  With the aforementioned thermal
gradient still in place, expect warmest temperatures to continue to
be across central Missouri on Tuesday with highs 3-5 degrees above
normal.  The next shortwave in line dips into the Great Plains
Tuesday afternoon/evening time frame.  This wave is stronger than
the one coming through Sunday night and between the stronger
synoptic forcing and a bit more moisture return ahead of the front,
we should see some precipitation.  Forecast instability shows as
much as 350-900 J/kg of MUCAPE ahead of the front so thunderstorms
still look like a good forecast Wednesday into Wednesday evening.
Looks like there may be some trailing precip behind the front, but
PoPs do drop off quickly after FROPA after 06Z Thursday.

Remainder of the medium range looks quiet with temperatures near or
a few degrees above normal.  Guidance has another cold front moving
into the area next Saturday or Sunday, but there`s little agreement
between medium range models for timing so am sticking with a dry and
relatively warm forecast on for next Saturday.



.AVIATION...  (For the 06z TAFs through 06z Sunday Night)
Issued at 1135 PM CDT Sat Oct 22 2016

VFR conditions are expected through the period. Surface high
pressure continues to slide off to the southeast tonight as an
area of low pressure moves across the Northern Plains. This regime
will help induce a low-level jet overnight, bringing a period of
LLWS to all sites early Sunday morning. Otherwise, Sunday will
feature southwesterly winds with gusts to around 15-20 knots,
turning more to the WNW by the end of the period as a dry cold
front moves through all sites.

VFR conditions are expected through the period. Winds will
increase out of the WSW just off the surface tonight, which will
lead to a period of marginal LLWS late tonight into early Sunday
morning. Surface winds will increase out of the WSW by Sunday
afternoon, which could cause some crosswind impacts on the three
larger runways. Otherwise, a dry cold front will push through
Sunday evening, turning winds more out of the WNW.



Saint Louis     78  48  66  47 /   0   0   0   0
Quincy          75  44  63  44 /   0   0   0   0
Columbia        75  45  66  48 /   0   0   0   0
Jefferson City  77  46  68  48 /   0   0   0   0
Salem           75  46  65  44 /   0   0   0   0
Farmington      76  47  67  43 /   0   0   0   0




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