250 
fxus63 kddc 230932 
afdddc 


Area forecast discussion 
National Weather Service Dodge City Kansas 
332 am CST Monday Nov 23 2009 


Discussion... 


Days 1-2... 


Dense fog continued to blanket the area from WaKeeney and Hays 
southeast through Larned and St John early this morning. Low cloud 
enhancement loops and surface observation show that the fog has been slowly 
developing southward into the Pratt and Medicine Lodge areas. 
Farther west visibilities have stayed up in the 3-5 Michigan range around 
Garden City and Dodge City...possibly in part due to a slight 
downslope component in the winds and a fairly shallow moist layer. 
Will expand the dense fog advisory farther south to include 
kptt-kp28 for now. 


00z upper air analysis showed a weak shortwave trough moving out of the 
Central Plains while a stronger shortwave trough was digging 
southeast through the northern rockies. Most of the short range 
model runs continue to show this system tracking southeast with an 
upper low closing off somewhere over northwest Kansas by this 
evening. Interestingly...the UKMET has earlier tended to dig the 
upper system the farthest south but the latest run looks similar 
to the European model (ecmwf). The NAM is now farther south and the GFS to a lesser 
extent. The track of the upper system will have a big impact on 
the southward extent of precipitation. 


Have leaned toward the timing and track of the GFS model for this 
update. Given a slightly further south track with this model have 
decided to raise probability of precipitation in the north but due to the model 
uncertainties will keep probability of precipitation in the chance category. Precipitation 
chances should be increasing during the afternoon hours and 
maximizing during the 00z-06z time frame. Model soundings show 
boundary layer temperatures dropping to near the freezing mark so 
would not be surprised to see a mix with or changeover to snow in 
the north during the evening. The models keep the upper system 
fairly progressive so think that precipitation should be winding 
down by Tuesday morning. 


Days 3-7... 


The models remain in reasonable agreement on a fairly uneventful 
weather pattern through the end of this week. On Wed, a rather 
vigorous trough will move into the upper Midwest with a decent 
shortwave rotating through the plains on the backside. The GFS/ec 
have flip flopped now with the GFS being further west and cooler 
than the ec. Nevertheless, the bulk of any cold air GOES by well 
east of US (and nothing hints of any chance of precip) and thus 
won't be making any changes to the going forecast for SW Kansas. Friday and 
Sat still look to be dominated by S/wave ridging over the plains as 
one trough moves into the NE Continental U.S. And another comes onshore along the 
Pacific coast. This will mean above normal temperatures and continued dry 
weather over Kansas into the first part of the weekend. A decent 
frontal passage is still scheduled for Sat night with much cooler weather on 
Sunday. This frontal passage continues to look dry as well. 


The models continue to show increased amplification going into next 
week and a tendency toward some sort of Arctic air intrusion into 
the Continental U.S.. the big question is how far south and west this air might 
get. The GFS is now much colder than the ec for next week (which is 
a flip flop on the part of the ec). Just taking the models at face 
value, we could have highs struggling to reach freezing next Monday 
(gfs) or highs in the 40s (ec). Also of interest is the potential 
for precipitation in such a pattern. The ec is now dry through 240hr over 
Kansas but am not inclined to believe a huge flip flop like that. Still 
think there exists a reasonable chance of a precipitation event but far too 
much uncertainty remains to pick a model at this point. Will 
continue to hedge on the cold/dry side of normal. -Wright 
&& 


Aviation... 


We are still watching for fog this morning. Khys is already socked 
in with LIFR visible/ceiling and temperature/dewpt spreads are less than 2 degrees 
at both kddc and kgck which makes them vulnerable to a rapid decent 
into LIFR. Think a small downslope component is keeping conds at 
kddc/kgck from declining but models are showing winds swinging 
around to south-southeast by 23/12z which would likely producing LIFR conds. Am 
leaning toward LIFR at all terminals by 23/12z and will update tafs 
to reflect that. Lee surface cyclogenesis will intensify as an upper 
trough moves into Colorado later this morning. This will increase 
gradient with winds and mixing increasing which will wipe out any 
remaining fog by 23/18z. Expect strong frontal passage at all terminals with 
winds going to northwest by 24/00z. -Wright 


&& 


Preliminary point temps/pops... 
ddc 52 29 49 24 / 10 10 10 0 
gck 49 27 47 22 / 10 10 0 0 
eha 52 27 51 24 / 0 0 0 0 
lbl 54 29 51 24 / 0 10 0 0 
hys 49 31 46 25 / 40 40 10 0 
p28 59 34 52 28 / 10 20 10 0 


&& 


Ddc watches/warnings/advisories... 
dense fog advisory until 9 am CST this morning for ksz030-031- 
046-065-066-081-090. 


&& 


$$ 


Fn02/34