Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 240738

238 AM CDT Fri Apr 24 2015

.SHORT TERM: (Through Sunday)
Issued at 235 AM CDT Fri Apr 24 2015

Heights continue to rise across the central CONUS as the deep
cyclone that brought a period of cool weather to the eastern half
of the country spins across New England. Meanwhile, a shortwave
located across southern California and Arizona is expected to move
toward and across the region over the next 48 hours.

Warm advection ahead of the system is well underway with a marked
increase in cloud cover over the last 6 hours.  Guidance in good
agreement that at least a few showers will develop this morning, but
confidence in coverage and how far east they will traverse in
question with dry low level air mass still entrenched across the
CWA. Have kept PoPs less than 30 percent today with the highest
values across central Missouri and the eastern Ozarks.  Otherwise,
believe temperatures will be a touch cooler than yesterday due to
the cloud cover with highs in the lower to middle 60s.

Chances of showers and thunderstorms really ramp up tonight as the
storm system approaches. Believe the best time for rapid development
and increase in coverage of preciptiation across the eastern half of
the CWA will occur between 05Z and 09Z. Then a dry slot punches
northeast through the CWA and quickly shifts the focus for rainfall
north and east of the CWA after 10Z. Highest threat of severe
weather has been pushed west across Kansas where best moisture
return will occur along with dry-line interaction.

The shortwave is forecast to become sheared as it moves in an
easterly direction across northern Missouri with the surface low
tracking east-southeast along Interstate 70 on Saturday. Along and
north of the low track, showers and clouds will help keep
temperatures cooler, while in the warm sector the threat of severe
thunderstorms may be realized across parts of southeast Missouri as
temperatures rise into the 70s. Not your typical setup for severe
weather in April, but can`t rule out a few severe storms mainly
south of St. Louis Saturday afternoon.

Cold front sweeps across the remaining CWA Saturday night with rain
ending from north to south. Should see some sunshine on Sunday, but
temperatures will once again struggle to climb back into the 60s
with cold advection taking place.


.LONG TERM: (Monday through Thursday)
Issued at 235 AM CDT Fri Apr 24 2015

Temperatures to moderate next week with a dry forecast. Cutoff low
appears to remain south of the CWA Monday through Wednesday with a
large ridge developing across the Rockies by midweek.



.AVIATION:  (For the 00z TAFs through 00z Friday Evening)
Issued at 1000 PM CDT Thu Apr 23 2015

VFR conditions and dry wx will prevail at the TAF sites thru
tonight. Showers are expected to develop late tonight and are
still anticipated to move into central MO just after 12z/Fri and
then attempt to proceed eastward to the airports near the MS river
by midday and into early afternoon. The best chances for thunder
will remain to the west, with COU being the most likely airport
out of the TAF sites here, and retained the thunder mention but
converted to VCTS. Otherwise, progressively and slowly
deteriorating prevailing conditions will be the rule for Friday
afternoon and into the night with widespread MVFR and perhaps IFR
CIGs developing eventually. E to SE surface winds will prevail
thru the period, gradually strengthening with time.

Specifics for KSTL: VFR and dry until late Friday morning, with an
episode of rain towards midday and into early afternoon expected.
Thunder should be limited enough with what should be a weakening
broken band of SHRA to preclude mention at this time. VFR
conditions will gradually transition to MVFR Friday night and
perhaps eventually to IFR. E-SE winds will be set by late this
evening and then gradually strengthen thru Friday. Another episode
of at least showers expected Friday night, with better chances for



Saint Louis     65  55  70  47 /  20  80  80  50
Quincy          62  51  61  42 /  20  90  80  40
Columbia        64  57  69  47 /  30  70  60  20
Jefferson City  65  57  71  49 /  30  70  60  20
Salem           64  53  67  48 /  20  90  80  50
Farmington      63  54  74  50 /  30  70  50  20




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