Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Springfield MO
317 PM CDT Tue Mar 31 2015
Short term...(this evening through wednesday)
issued at 317 PM CDT Tuesday Mar 31 2015
Left over isolated convection will remain possible early this
evening across far south-central Missouri as a low level frontal
boundary (925-850 mb layer) clears the region. Otherwise, dry
weather is expected tonight.
We will have to watch for some fog potential across southern
Missouri and extreme southeastern Kansas, although confidence in
fog development remains low. There are two potential scenarios
that would increase confidence. The first would be more in the way
of widespread rainfall across south-central Missouri into early
this evening. The second would be that low level frontal boundary
stalling further northeast from eastern Kansas into northern
Arkansas. Right now, the best prospects for fog appear as if they
will remain back towards central Kansas and down closer to I-40.
With drier air advecting into the region from the north, lows
tonight should be able to drop into the middle to upper 40s across
central Missouri. Dew points will be higher across far southwest
Missouri where lows will be in the lower to middle 50s.
Broad southerly flow continues across the region on Wednesday
advecting low level moisture northward. Frontal boundary strengthens
across the plains and extends from southwest Kansas into southern
Minnesota by 00z. This front will be the focus for convection during
the day and evening hours. Cannot rule out a few showers or
thunderstorms in the warm advection pattern over the forecast area.
However, deep layer shear looks rather weak and tied closer to the
front over Kansas. As pressure gradient tightens southerly winds
with some gusts to 30 mph will be possible, especially in areas west
of Interstate 49.
Long term...(wednesday night through tuesday)
issued at 317 PM CDT Tuesday Mar 31 2015
Frontal boundary will slide southeast Wednesday night and Thursday
and affect the forecast area mainly Thursday afternoon and Thursday
night. Precipitation probabilities will increase with time with the
best chances late Thursday afternoon into Thursday night. Plenty of
deep layer shear with eroding cap as front approaches. However,
model soundings indicate Uni-directional low level shear in vicinity
of front. Linear forcing along front combined with increasing
instabilities and mid level lapse rates will lead to mainly a hail
and wind threat for the area Thursday afternoon into Thursday
Front will slowly sag southward across the area Thursday night. GFS
showing a stronger surface wave riding up along the front, while NAM
is slightly more progressive. If GFS verifies would likely see
severe weather threat evolve into a heavy rain threat late Thursday
evening and overnight and possibly into the early morning hours of
Friday. Will have to watch this closely.
High pressure then drops across the area Friday night into Saturday
for quiet but cool weather. Will have to watch for the potential for
some frost Saturday morning as the high is expected to be centered
over northern Arkansas and southern Missouri. Zonal flow then
re-establishes itself across the mid section of the conus Saturday
nigh into Sunday as high drops into the southeast United States.
Return flow establishes itself Sunday and especially Sunday night
through Tuesday. With increasing low level moisture and developing
surface low over Kansas medium range models pointing to more active
weather from Sunday night into Tuesday.
Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 1237 PM CDT Tuesday Mar 31 2015
MVFR ceilings will improve to VFR for most of southern Missouri
this afternoon. A cold front will push into southern Missouri and
is expected to produce scattered thunderstorms over south-central
Missouri. Some of this activity is expected to develop in the
vicinity of the Branson terminal.
Any thunderstorm activity will quickly diminish this evening with
dry weather expected overnight. Some weather models are indicating
returning MVFR conditions (ceilings and visibilities) late tonight
or early Wednesday morning across portions of southern Missouri.
The greatest prospects for this occurring will be around Joplin
Winds will also increase out of the southeast on Wednesday and
will exceed 12 knots at Joplin and Springfield.