Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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FXUS63 KEAX 241407
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
907 AM CDT Tue Mar 24 2015

.UPDATE...
Issued at 906 AM CDT TUE MAR 24 2015

Have sent a quick update to mainly PoPs but also to temperatures.
Adjusted PoPs to keep with current activity and to adjust for late
morning/early afternoon lull in activity. For our southeastern zones,
this resulted in removal of PoPs until this afternoon. Temperatures
were also lowered across from about I-70 northward. Latest short-term
guidance is in pretty good agreement that the surface slow will track
along our southern CWA border, roughly from about Linn County, KS
through Cooper County, MO. This will make it hard for areas to the
north to warm much as the warm front will just not lift that far
north. This will also make it more difficult to get severe storms
into much more than just the southern extremity of the forecast area.

Satellite imagery and observations indicate a rather expansive
stratus layer underneath the EML, evident on WV imagery. However, the
12Z SGF sounding shows this stratus layer to be fairly thin/shallow.
So think there is a decent chance for it to erode later this
morning/early this afternoon. Should this occur, we should see enough
destabilization in our far southern CWA and points south that severe
storms could develop. Short-term guidance continues to show
convection breaking out along the KS/MO state line late this
afternoon and then tracking to the east-northeast. At this point have
no reason to discount this based on the potential for the thin
stratus to erode.

&&

.DISCUSSION...
Issued at 308 AM CDT TUE MAR 24 2015

Current - This Morning:

Showers and thunderstorms have continued to fill in across
northern MO, with the bulk of the activity in this forecast area
setting up along and north of the I-70 corridor, coincident with
850-700mb frontogenesis. Additional, albeit not as widespread,
activity has slowly been firing up across the southern half of the
forecast area over the last few hours, along and just north of the
frontal boundary draped across central MO. The lower resolution,
coarser models have not had a good handle spatially or temporally
on this morning`s early convection so have relied more upon
current trends/obs and hi-res models to update the forecast
through the remainder of this morning. The freezing level has
dropped to near the surface across NE MO but with such a stout
warm nose in place in the mid-levels, rain should continue to be
the dominant precip type through dawn, with just some small hail
mixing in area-wide with any stronger storms. As long as
temperatures level off, as they are anticipated to do for the next
few hours, freezing rain shouldn`t be a concern for locations in
the far northeastern portions of the forecast area. With how warm
it has been as of late, accumulations shouldn`t be a concern. That
said, any early morning travelers are encouraged to maintain
awareness of the ambient temperatures as elevated surfaces could
become slick if any further decrease in the temps occurs.

Midday Today - Wednesday:

Surface low currently progged in the vicinity of the TX and OK
panhandles will continue to approach and cross MO by tonight. As
decent moisture transport continues to be pulled into the region
today, showers and storms will continue throughout much of the
day. North of the I-70 corridor, where the atmosphere has been
well worked over this morning, it`ll continue to transform more
into a stratiform rain event with only some isolated thunder
possible, complete with a stratus deck and drizzle outside of any
rain showers. The same cannot be said for locations south of I-70,
however, where better instability will be able to work its way in
ahead of the approaching low. Therefore, thunderstorms firing up
this afternoon with the diurnal heating (increasing instability)
and northward lift of the warm front to the south before the low
traverses through will allow for some storms to become strong to
severe with large hail being the primary threat, although strong
to damaging winds cannot be ruled out. Upper level trough ejecting
out of the Rockies today will become more amplified and
negatively-tilted but by the time it all comes together along with
the necessary ingredients to support more widespread severe
weather, the higher threat should remain more toward the south and
east of this forecast area, which has also been highlighted in the
latest Day 1 SPC outlook. But again, severe weather this afternoon
is not to be ruled out for this afternoon for locations south of
I-70.

As the low exits the region off toward the northeast tonight, so
will the precip chances, allowing for a brief period of benign
weather through early Wednesday. On the heels of the exiting low,
another low develops in the vicinity of the OK/TX panhandles
again, but this time will lose out to positively-tilted upper
trough swinging through the Plains, keeping the low well to the
south of here. Additionally, high pressure attempting to take
control across the northern Plains will battle with the southern
low, tightening the pressure gradient across this area. Another
frontal boundary is slated to setup across central MO on
Wednesday, but looks to remain more in the SGF forecast area,
providing the focus for convection across southern MO rather than
in this area as a result. Better instability parameters look to be
in existence across southern MO by Wed. afternoon but the better
dynamics should be across this forecast area. Putting it all
together, look for some convection possible Wednesday afternoon
with the possibility of isolated strong storms not out of the
question, especially if the higher instability can work its way
further north than currently visualized in the models, and
especially given that there won`t be any morning convection to
contend with, as is the case this morning.

Wednesday Night - Tuesday:

Much quieter weather is expected during this time frame with some
precip chances scooting across eastern KS and southern MO Thursday
night as aforementioned upper-level trough axis (the positive one)
and associated vort max swings on through. Depending on how cold
it gets that night could depend on whether or not the precip will
fall as rain or snow, with a mix possible if a transition does
occur. Any precip that does fall should remain light with no snow
accumulations expected, if it snows. Another quick-hitting bout of
light precip could fall overnight Friday as the region sits on the
periphery of high pressure centered over the Great Lakes region.
Beyond this point, however, the long-range models diverge,
lowering the forecast confidence for precip chances from this
weekend through early next week.

Temperatures:

Temp gradient will exist today with respect to the highs with 40s
and 50s north of the I-70 corridor and 60s to the south, assuming
cloud cover doesn`t hinder those latter highs and that the lifting
warm front aids in the diurnal increase. Look for about a ten
degree increase in highs tomorrow in northern MO but similar highs
compared to today, potentially a few degrees warmer as well.
Widespread cool down returns Thursday through the weekend with 40s
and 50s for highs and 20s and 30s for lows. This cool down
shouldn`t last long though, with temps rebounding into the 60s by
the end of the weekend and greeting the new work week.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 636 AM CDT TUE MAR 24 2015

For the most part, the activity this morning has lost much of its
lightning, although could continue to see some in-cloud/cloud-to-
cloud lightning persisting. Could see a bit of a break in precip
later this morning at the terminals with the exception of STJ, as
indications point to continued rain chances throughout the entire
day. Better chance for convection should be limited to the IXD
area but can`t be entirely ruled out for MKC and MCI as well later
this afternoon as low pressure system approaches and crosses
through central MO. On the backside of the low tonight, winds will
shift, coming out of the W-NW, then becoming more southerly by the
pre-dawn hours Wed. Precip will have also cleared the terminals
overnight, allowing for fog to develop, especially at the fog-
prone STJ terminal where plentiful rain has already and will
continue to fall.


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

UPDATE...CDB
DISCUSSION...lg
AVIATION...lg






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