Debate de meteorólogos científicos

NWS Discussion
			
				

Area forecast discussion 
National Weather Service Cheyenne Wyoming 
333 PM MDT Wednesday may 22 2013 


Short term...(this evening through thursday) 
issued at 233 PM MDT Wednesday may 22 2013 


A few showers have developed this afternoon across Albany and 
Carbon counties. Isolated shower activity will continue into early 
this evening before dying off. Showers will try to push eastward 
and could reach the Nebraska border by this evening...but that may 
be pushing the eastern extent of any activity as a low level 
inversion will be strengthening this evening as cool moist low level 
air advects westward. Shower activity could be accompanied by a few 
weak thunderstorms...but those will be few and far between. Severe 
thunderstorms not expected but could see a few stronger wind gusts 
given 30 to 40 degree surface dew point depressions. There is a 
very small chance for elevated showers to spread east across the 
Panhandle this evening in association with an elevated warm front. 
Not a lot of moisture to work with so kept probability of precipitation below mention in 
the forecast but something to keep an eye on this evening. 


Stratus deck has held firm all day at Chadron and Alliance. The 
stratus will work its way west this evening...banking up along the 
Laramie range. Some of the low clouds may spill into the Laramie 
valley. Fog will be possible across the Nebraska Panhandle and 
portions of southeast Wyoming...especially along the Laramie range 
where locally dense fog may form tonight. Southeast winds will 
ratchet upward tonight with some of the strongest winds east of the 
Laramie range. Could easily see some gusts over 40 miles per hour tonight 
such as around Douglas. 


With the stratus deck holding firm Thursday under southeast 
flow...temperatures will struggle to rise anywhere east of the 
Laramie range...while mostly sunny and warm temperatures will be 
found in the west under southwest flow. Cut back on chances of 
thunderstorms east of the Laramie range with isolated showers and 
thunderstorms west. Chances for thunderstorms along the Laramie 
range are difficult to handicap...depending on whether or not low 
clouds mix out. Certainly a convergence zone with southwest winds 
meeting southeast winds...so should cap weaken...a few storms 
would be possible. Not expecting severe thunderstorms...but with 
cape and shear would be supportive of a few stronger 
thunderstorms. 


Status should stay locked in over the area into Thursday 
evening...but the models are bringing in a strong punch of dry 
southwest flow aloft Thursday night and Friday. Stratus should 
erode from west to east during this time. This will mean much 
warmer temperatures Friday for places such as Cheyenne and 
Douglas. The main question is how far east will the dry air make 
it. A large temperature difference can be expected over a short 
distance come Thursday afternoon...but where that line sets up is 
the main question. Chances for thunderstorms will exist along and 
east of the dry line Friday afternoon. Shear and cape profiles 
conducive of severe thunderstorms capable of producing large hail 
with tornadoes not out of the question. For Friday evening...the 
dry line is expected to retreat westward. Storms very well may 
fire along the retreating dry line. 


Long term...(saturday through wednesday) 
issued at 310 PM MDT Wednesday may 22 2013 


Warmer and mainly dry conditions expected Saturday in southwesterly flow 
with surface boundary expected to be northeast of the County Warning Area...though not 
far. Pattern then remains quite similar Sunday through Wednesday 
with SW flow aloft over the County Warning Area ahead of an upper trough that will 
hold over the Pacific northwest. Periodic upper shortwave will pass 
across the region and bring some afternoon and evening convection 
but hard to say which days will be best for this. Right now Monday 
and Tuesday looking somewhat better. Temperatures will remain warm 
through the period. 


&& 


Aviation...(for the 18z tafs through 18z Thursday morning) 
issued at 1125 am MDT Wednesday may 22 2013 


Low clouds gradually breaking up from kcdr to kaia late this morning 
and should continue to break up to VFR early this afternoon. A few 
showers or thunderstorms this afternoon into this evening mainly around the 
southeast Wyoming mountains moist southeast winds tonight should cause low clouds 
with IFR ceilings to redevelop between 06-09z over the plains. 


&& 


Fire weather... 
issued at 233 PM MDT Wednesday may 22 2013 


Low clouds and fog to spread across the Nebraska Panhandle and 
southeast Wyoming east along and east of the Laramie range tonight. 
While the fog will burn off Thursday but low clouds and cool damp 
conditions will persist. West of the Laramie range it will be 
dry and warm under southwest flow aloft. For Friday...dry conditions 
are expected to shift east across the remainder of Wyoming along 
with much warmer temperatures. Thunderstorms are possible over the 
Nebraska Panhandle Friday afternoon and evening. 


&& 


Cys watches/warnings/advisories... 
Wyoming...none. 
NE...none. 
&& 


$$ 


Short term...liebl 
long term...re 
aviation...re 
fire weather...liebl