Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 190501 AAB
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1201 AM CDT Sun Apr 19 2015
...Updated Aviation Section...
Issued at 703 PM CDT SAT APR 18 2015
Forecast will be updated shortly to account for short term trends
from satellite/radar as well as to account for expected convective
trends heading into the overnight hours.
Over the past few hours, we have seen clearing across western
portions of the area. This clearing will likely be short lived as
mid/high level clouds increase from the west from convective
exhaust. That said, this area did see a soaking rain this morning
and dewpoints remain relatively high compared to expected lows. As
a result, will include a mention of patchy fog and keep an eye on
localized dense fog potential in places where skies can remain
clear for a longer period of time.
In addition, PoPs have been updated for the next 12 or so hours.
The western half of the area will likely see little in the way of
rain chances this evening. Chances over the eastern half look to
remain in the solid chance range giving on again/off again showers
and isolated thunder. HRRR and other short range models continue
to indicate rain chances increasing across south central Missouri
and the eastern Ozarks from late this evening into the overnight
hours. In addition, remnant convection from KS/OK complexes will
enter from the west, with rain chances steadily increasing
across extreme southeastern Kansas and western Missouri.
Interestingly, the Highway 65 corridor will likely be between
these two areas of activity and PoPs are lowest in this area for
Taking a peak at tomorrow`s severe weather potential. There
remains some question as to just how much instability we will be
able to generate as decaying convection continues to spread in
from the west during the morning hours. The main upper trough will
not arrive until later in the day, bringing and increase in deep
layer shear. However, models struggle to bring much more that
500-1000 J/kg of most unstable CAPE into the southern half of the
area. By far the better chances for severe convection will be to
our south and southeast. Obviously this is close enough to keep a
close eye on trends and we will see what the 00z suite of models
have in store for the area.
.SHORT TERM...(This Evening through Sunday Night)
Issued at 315 PM CDT SAT APR 18 2015
The coverage of showers and thunderstorms continued to decrease into
the afternoon. However a band of scattered showers and storms persisted
along a 925-850 MB convergence axis that stretched north to south
east of the Highway 65 corridor and in advance of a mid level vorticity
lobe lifting northeast across the area. Expect convection through
early evening to be focused along and ahead of these features
across south central Missouri. This 925-850 MB convergence axis
may become the focus for additional development later tonight
across the eastern Ozarks as another vorticity lobe lifts
northeast toward southeastern Missouri. Coverage of precipitation
will remain more isolated elsewhere much of tonight. However there
may be increase in convection from the west into southeastern
Kansas into far southwest late tonight as convection across the
Plains shifts eastward.
The closed upper level low now over eastern Colorado will open up
and track eastward toward Missouri on Sunday. Expect the coverage
of convection to increase Sunday as synoptic scale lift increases
with the aide of an increasingly diffluent upper flow and the
approach of vorticity maxima.
Deep layer shear will increase Sunday as the mid level flow
strengthens and lapse rates steepen as temperatures aloft cool in
response to the approaching upper level trough.
The question is the extent of instability that will develop. The
potential for ongoing convection and cloud cover may limit surface
heating and resulting instability. However if sufficient
instability can be realized then ingredients would be in place for
at least a few severe storms.
At this time the greatest potential for strong to severe storms
will be across far southern Missouri or generally along and south
of Interstate 44. The risk for severe weather could decrease or
increase depending on the amount of destabilization. The primary
risks with any severe storms that can develop would damaging winds
and large hail.
With some areas already receiving moderate to heavy rainfall the
past couple of days...the risk for localized flooding will have to
be monitored particularly across far southwestern Missouri.
Showers and some thunder will linger into Sunday night as the
upper level trough and associated cold front track across the
.LONG TERM...(Monday through Saturday)
Issued at 315 PM CDT SAT APR 18 2015
Much cooler weather will prevail heading into early next week as
an upper level trough digs into the Great Lakes and maintains a
northwesterly flow aloft across the region. This cooler weather
will persist most of next week. Weather conditions could also be
rather unsettled as disturbances slide southeastward around the
periphery of the upper trough. This will bring intervals clouds and
the possibility of showers and thunderstorms at times mid through
late week. However this activity is expected to be spotty in
Temperatures could fall into the upper 30s Monday night. Frost is
not expected at this time but this potential should be monitored.
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1201 AM CDT SUN APR 19 2015
Challenging forecast for area aerodromes as convection will fester
around the region the rest of tonight, and regenerate Sunday
afternoon. Decaying bands of showers/storms will attempt to enter
from the west in the coming hours, however a lack of instability
will likely result in this activity losing its punch and gradually
dissipating as it moves through the JLN aerodrome. Earlier
clearing at SGF/BBG is being replaced by mid/high level clouds.
There is patchy ground fog around, but this may not become too
widespread. Bouts of MVFR visibility are expected, with an outside
chance of IFR at BBG. Main storm system will move into area Sunday
afternoon/evening. Another round of showers/storms will be
associated with this system, which will begin to exit to the east
by the end of the TAF cycle. Winds will be light into the daylight
hours of Sunday morning, becoming southwesterly during the day and
shift to the northwest heading into the evening.