358 
FXUS63 KEAX 280537
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1137 PM CST Sun Jan 27 2013


...UPDATED AVIATION DISCUSSION...


.DISCUSSION...

Short Term (Today through Tuesday)...

Satellite imagery from this afternoon shows us that the 
shortwave, responsible for this mornings rain, continues its trek 
northeast, with the radar indicating that the majority of the rain 
has gone with it. Surface observations highlight the warm front 
moving north past the Missouri River this afternoon, though visible 
satellite imagery shows it best as the dry slot, moving in under the 
shortwave, has helped clear clouds across east central Kansas into 
central Missouri as deep layer mixing kicks in south of the front. 

Tonight, the lifting warm front is expected to stall later tonight 
across far northern Missouri, allowing clouds to fill back in across 
central Missouri as moisture continues to stream north. Currently 
patchy fog persists this afternoon across far northwest Missouri. 
This area will likely expand tonight, leading to the development of 
fog across the western and northern reaches of the forecast area 
thanks to the moisture in the boundary layer. Kept fog out of 
central Missouri due to more wind, cloud cover, and warmer overnight 
temperatures, though this will require careful watching tonight. 
Speaking of warm overnight lows, expect areas south of the front 
--about 2/3 of the forecast area-- to stay in the 50s overnight.  
Areas along or north of the expected stalled front --in far 
northwest Missouri-- will likely experience much cooler lows in the 
mid to upper 30s.

Monday the front will continue to move north as another shortwave 
moves out ahead of the mean trough that will slowly progress through 
the Plains States during the work week. Cloud cover could still be 
fairly substantial, but strong surface warm air advection, and any 
breaks in the clouds, should allow near record to record setting 
highs for Monday; 60s into the 70s. However, up north along the Iowa
border, fog and drizzle are expected to linger as the front slowly
shifts north, keeping highs a little cooler --around 60--.

Monday night into Tuesday, the mean trough will begin moving into 
the Plains in earnest, with a dynamic jet shifting across the 
central Plains. Induced lift from this synoptic scale system will 
likely pool moisture and instability south of the front that lifted 
through the region during Monday. Models point at the after midnight
periods (early Tuesday morning) as being when storm chances will
begin to ramp up quickly, with storms expected across southern and
eastern Missouri through the day Tuesday. Have characterized storms
Monday night into Tuesday as thunderstorms as elevated instability of
200 to 400 J/kg is noted. Can not rule out the potential for some
minor hail or bowing segments with any storms that can get going
overnight in Tuesday, though it is not currently anticipated as the
environment looks to be a bit over balanced with strong shear,
especially during the day Tuesday, so gusty winds might be the
primary concern. 

Otherwise, by late Tuesday night the last of the rain should be
shifting east as the mean trough shoves a cold front through the
region. Flurries may linger through Tuesday night into Wednesday as a
result of the strong cold air advection.
 
Cutter


Medium Range (Wednesday through Sunday)...

As has been the trend this winter, we will see another strong cold 
front track through the region providing little to no precipitation. 
By Wednesday the front will have already passed through the region 
which will lead to only a very small diurnal range in temperatures 
from the morning lows. Highs may be able to rebound only a few 
degrees as cold advection really dominates the flow.  A secondary 
surge of cold air will funnel into the Plains as another arctic high 
pressure moves into the region behind a weak upper level system 
rotating around the main Hudson Bay longwave trough. The result of 
this is Thursday's diurnal range will be similar to Wednesday but 
overall, temperatures will be some 5 to 10 degrees colder. Given the 
strong cold advection, departed some from the populated forecast 
consensus and lowered highs several degrees. 

That weak upper system will also bring a small chance for light 
snow. While chances don't look particularly good, they don't appear 
to be non-zero either, so for now will just mention PoPs on the 
order of 15 to 20 percent. It doesn't not appear to a significant 
system and the duration of precipitation would be short so QPF is 
very light, likely a trace to a light dusting if that. 

The arctic high pressure will move over the area by Friday morning 
resulting in very cold temperatures across the forecast area.  
Models are in decent agreement showing a 1030mb surface high 
overhead, or nearly overhead and this will likely result in very 
good radiational cooling. So similar to Thursday, have departed from 
the populated forecast consensus and lowered temperatures several 
degrees.

That high pressure will move east of the region by Friday and 
Saturday. We may see a glancing shot of cold air as we still have  
slight cyclonic curvature allowing for another but weaker front to 
move through the area Saturday. So while it looks like it warms 
through the first half of the weekend, confidence is not especially 
high regarding the temperature forecast. Flow becomes southwesterly 
by Sunday and with strong warm advection aloft so by the end of the 
weekend we could see highs climb into the 40s and 50s.

CDB

&&

.AVIATION...

For the 06Z TAFs: MVFR stratus continues to expand throughout eastern
Kansas and northern Missouri tonight and will remain entrenched
through at least mid-day Monday. Models in general have backed off on
the development of very low LIFR visibility and ceilings around
daybreak. However, still feel the development of IFR ceilings will be
likely after 09z as a frontal boundary drops into northern Missouri.

Expecting stratus to remain in place along and north of the
aforementioned front through early afternoon before erosion rapidly
begins in southeastern Kansas and spreads northeast. Ceilings should
quickly scatter or lift by 21Z as warm air pours northward. VFR
conditions should prevail Monday evening in most locations, as a warm
front lifts well into Iowa. Low confidence at this stage and haven't
included in current TAF, but scattered showers or even thunder may
develop Monday evening.

31


&&

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

$$

WFO EAX