Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 271737
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1237 PM CDT Wed May 27 2015
...18z Aviation Update...
.SHORT TERM...(Today and Tonight)
Issued at 258 AM CDT WED MAY 27 2015
Loose clusters of elevated thunderstorms have developed during the
late overnight hours across the Missouri Ozarks. This convection
has developed in response to isentropic upglide lifting parcels in
the 850 to 750 mb layer. A few updrafts have reached thresholds
supportive of marginally severe hail, but rather weak effective
deep layer shear has precluded more in the way of severe hailers.
Leftover activity may still be ongoing after sunrise across
primarily southern Missouri. Otherwise, convective chances for
the remainder of today are a tough call. From a synoptic scale
standpoint, height rises and the presence of mid/upper level dry
air (especially across central Missouri) may tend to limit
redevelopment. However, there may be an outflow boundary or two
around. A weak low level convergence zone is also indicated by
models extending from northwest to southeast across central
Missouri and the eastern Ozarks this afternoon. Thus, isolated to
widely scattered development will be possible. That dry air and
associated precipitable water values will be a bit on the low side
for severe thunderstorm potential. However, a few storms may
produce gusty winds and small hail this afternoon and early this
evening. High temperatures today should be a few degrees warmer
than those of Tuesday as there will be less in the way of cloud
Those upper level height rises should then keep most areas of the
Missouri Ozarks dry as we head into tonight. Some activity may
manage to sneak into far western Missouri later tonight as the
eastern flank of a low level jet approaches the region. We may
have to watch for some fog development if skies remain clear
enough. Confidence in fog is not quite high enough yet to insert
into the forecast or Hazardous Weather Outlook.
.LONG TERM...(Thursday through Tuesday)
Issued at 258 AM CDT WED MAY 27 2015
The synoptic scale flow will then back to southwesterly starting
on Thursday with models bringing short wave energy into the region
later in the day. Ideal timing of this wave should result in the
development of at least scattered convection during the peak
heating of the day. Gusty winds and perhaps some hail appear
possible with a few of the storms...especially over western
Missouri and extreme southeastern Kansas.
Global models then bring a more substantial short wave trough out
towards the Ozarks from late Thursday night into Friday.
Meanwhile, models continue to show another separate wave coming
out of the central High Plains and driving a cold front into the
Ozarks sometime Friday night or Saturday. The Friday to Saturday
period therefore looks unsettled with a good chance for showers
and thunderstorms. We will have to watch the hydro situation
closely for this period given the recent heavy rainfall.
That front should clear the area by Sunday with most areas seeing
a break in the rain. The 00 UTC GFS wants to hang onto a closed
upper level low down around the Arklatex early next week. It seems
to be the outlier with both the ECMWF and Canadian models
progressing an open wave towards the Ohio Valley by Monday. We
have therefore kept PoPs pretty close to climatology early next
week (20-30% range). Temperatures early next week will be cooler
behind that cold front. We may begin to see a warming trend by
mid-week as upper level ridging begins to spread in from the west.
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1237 PM CDT WED MAY 27 2015
After morning storms, clouds have decreased across the region this
afternoon. Generally, VFR conditions expected through much of the
afternoon, evening, and overnight. That being said, we cannot rule
out a stray shower or thunderstorm, especially closer to the BBG
and SGF terminals.
Confidence in AM fog potential is left unchanged since the last
update. Decided to indicate some threat in the forecast, however,
cloud cover trends and precip this evening will likely influence
AM VIS forecasts.