960 
fxus63 kddc 212115 
afdddc 


Area forecast discussion 
National Weather Service Dodge City Kansas 
315 PM CST Sat Nov 21 2009 


Discussion... 


Days 1-2... 


The main forecast focus will on the chance for precipitation late in the 
period and temperatures. 


WV imagery and 12z upper air analysis indicates an upper level 
S/wave trough of low pressure moving southeast across the Pacific 
northwest. A +80kt upper level jet...just off the Pacific northwest 
coast...is streaming southeast into northern California. Near the 
surface, a Lee side trough of low pressure is strengthening in 
eastern Colorado. 


Short range models are in general agreement indicating the upper 
level S/wave trough in the Pacific northwest continuing to slide 
southeast across The Rockies tonight and into the western High 
Plains by daybreak Sunday. This feature will push an attendant 
cold front east into western Kansas early Sunday morning and 
across the County Warning Area by Sunday afternoon. However, this is expected to be 
a fairly dry frontal passage due to the lack of low level moisture and the 
front itself being fairly weak. Meanwhile, a secondary upper level 
trough will push ashore in the Pacific northwest on Sunday and dig 
southeast into the western High Plains by early Monday morning. This 
will push yet another cold front into western Kansas by middle day 
Monday and along with it the possibility for precipitation. This system is 
expected to be somewhat stronger but moisture will still be lacking 
with the passage of the previous front the day prior. Although, 
there is some discrepancy as to the track of this upper level system 
which could be a key factor. Both the NAM and the GFS show a closed 
off low developing by Monday afternoon as it moves southeast across 
the northern plains of South Dakota and Nebraska resulting in the 
bulk of any precipitation staying well north of southwest Kansas. 
However, the UKMET suggests a somewhat more southerly track with the 
closed low moving southeast into western Kansas during the same time 
frame. As a result, will continue with just slight probability of precipitation across the 
County Warning Area Monday afternoon due to the uncertainty. The marginally 
better chance for rain would be across northern portions of the 
forecast area. 


Low temperatures will remain above normal tonight under the 
influence of a low level southerly flow across southwest Kansas. 
The NAM, GFS, and UKMET all show temperatures at 850 mb around 5c 
across much of the County Warning Area. Should expect to see lows in the 30s(f) 
across west and northwestern portions of the County Warning Area tonight, 
particularly as the approaching cold front begins working it's 
way into extreme western Kansas just before daybreak. Lows will 
be in the low 40s across our southeast. For Sunday, high 
temperatures will be near seasonal in wake of the weak cold frontal passage 
Sunday morning. Temperatures at 850 mb will range from around 5c 
across eastern zones to near 7c across our extreme southwest. This 
will result in highs mainly in the 50s(f) across the County Warning Area Sunday. 
For Sunday night, low level southerlies will quickly, but briefly, 
return ahead of yet another approaching cold front that will begin 
pushing into extreme western Kansas by daybreak Monday morning. 
Lows mainly in the 30s(f) can be expected again Sunday night. Highs 
will struggle to climb into the 50s(f) Monday as the next cold 
front pushes across southwest Kansas by early afternoon. A few 
upper 40s(f) will be possible across our northwestern border. Plan 
to make only slight adjustments to temperatures. 


Days 3-7... 


Questions in the forecast center mainly around temperatures for the 
upcoming week...with essentially no chance for precipitation through 
the period. 


Significant cyclogenesis event will occur north of the ddc forecast area at the 
beginning of the forecast period (mon night/tuesday). As it appears 
now...southern edge of precipitation with this event will most 
likely remain just north of the ddc forecast area as the brunt of this storm 
will impact Nebraska. An Arctic air source is non-existent with 
this storm system...so when the cold front moves through late 
Monday...the wind shift will be the main sensible weather change of 
notice. Downslope modification will occur quickly Tuesday with 
temperatures warming back up into the upper 40s to lower 50s. As 
upper level ridge amplifies across the west...another shortwave 
trough will move south-southeast through the eastern plains/Midwest 
Wednesday. This will send a reinforcing shot of cool air (not cold) 
into Kansas. Again...for western Kansas...the airmass is expected 
to be modified by downslope component with only slight cooling in 
high temperatures Thanksgiving day vs. Wednesday. 


Positively tilted upper level ridge will move across The Rockies and 
adjacent High Plains at the end of the week...which is very 
favorable for a solid warm-up well into the upper 50s to lower 60s 
Friday...and perhaps even warmer than that Saturday depending on the 
timing of the next cold front. In the day 8-10 time 
frame...unsettled weather may impact the Western Plains...however 
there is far too much white noise in the synoptic scale global 
spectral model solutions for the important Sunday (29th) travel day. 


&& 


Aviation... 


A return to LIFR conditions is expected in the roughly 10-16z time 
frame early Sunday morning as low level moisture remains in place 
with a weak frontal boundary at the surface across southwest 
Kansas. Dense fog is also a distinct possibility at any one of the 
southwest Kansas taf terminals (kddc, kgck, khys). 
&& 


Preliminary point temps/pops... 
ddc 37 53 33 52 / 0 0 0 10 
gck 35 55 30 48 / 0 0 0 10 
eha 33 55 30 50 / 0 0 0 10 
lbl 35 55 32 52 / 0 0 0 10 
hys 37 53 33 48 / 0 0 0 20 
p28 43 57 38 58 / 0 0 0 20 


&& 


Ddc watches/warnings/advisories... 
none. 
&& 


$$ 


Fn32/25/25