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fxus63 keax 220446 
afdeax 


Area forecast discussion 
National Weather Service Kansas City/Pleasant Hill MO 
1146 PM CDT sun Mar 21 2010 


..updated aviation discussion... 


Discussion... 


Short range (tonight-tue) 


Due to the late March sun angle...temperatures have warmed nicely 
despite the snowpack. Areas which saw plenty of sunshine warmed into 
the 40s with upper 40s in northeast Missouri where less snow fell. 
As the late winter storm system continues to move off to the east 
and the surface ridge moves overhead...skies will continue to clear. 
Winds will also diminish...leading to a good drop in overnight temperatures 
with readings falling well into the 20s most locations. Skies will 
take a little longer to clear over portions of central 
Missouri...therefore temperatures are not expected to drop much below the 
upper 20s there. 


The surface ridge will slowly move east through Monday and Monday 
night. Despite light winds and little mixing...expect temperatures 
to continue the warming trend with readings ranging from the middle 40s 
over east central Kansas and west central Missouri where several 
inches of snow remain...to the middle 50s across far north and 
northeast Missouri...where the snow has melted or is expected to 
melt away quickly. 


Overnight temperatures Monday night should not drop off quite as 
much tonight with winds becoming southerly and a thin layer of 
middle-high level clouds approaches the region ahead of the next 
trough. Temperatures are expected to cool into the lower and middle 30s 
with the cooler readings expected over central and eastern 
sections...closer to the ridge. 


The warming trend will continue on Tuesday and Tuesday night as middle 
level flow briefly becomes more zonal and surface flow becomes more 
southwesterly ahead of the approaching northwest Pacific trough and 
associated weak cold front...and most of the snow is gone. 


Nrr 


Medium range (wed-sun)... 


In the medium range portions of the forecast...main concerns fall on 
precipitation chances as well as temperatures. Model guidance remains consistent in 
bringing a weak cold front through the region late Tuesday night or 
very early Wednesday morning as previously discussed northwest Pacific short wave 
dives into the Southern Plains. This front will make temperatures tricky 
for Wednesday as cloud cover should be fairly widespread with the 
front. Nevertheless...the area should be able to reach into the 
lower 50s. 


This front will hangup across the Ozarks ahead of the approaching 
short wave trough 12z GFS remains a bit further north than the 00z 
European model (ecmwf)...pushing the front back northward to the Iowa border as a warm 
front on Wednesday night regardless of the solution...appears a fairly decent 
chance for additional rain will be present in the area Wednesday afternoon 
through early Friday morning. Given the influx of slightly drier air 
from the Great Lakes am expecting a fairly well defined northern 
periphery of rain...which should take aim in areas along and south 
of the I-70 corridor. Temperatures throughout this event should fall near 
or slightly below climatology normals in the middle-upper 50s for highs 
with lows around the middle-upper 30s. 


This system will clear the area on Friday with another brief warmup 
in between systems. A pesky pattern will bring another short wave into the 
area from the Pacific northwest by the middle part of the weekend. Fairly 
consistent model guidance leads to higher confidence and thus have 
bumped up probability of precipitation for Sat night and Sunday. 


Dux 




&& 


Aviation... 


For the 06z tafs...drier air continues to advect south with VFR 
conditions. The air mass is quite dry...especially just above the 
surface. As a result...the probability of any fog development with light 
winds and wet ground appears quite low at this time. Plan to maintain 
VFR conditions through the taf period as a weak high pressure ridge 
settles over Missouri. 


Db 


&& 


Eax watches/warnings/advisories... 
MO...none. 
Kansas...none. 
&& 


$$