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fxus65 kcys 060919 
afdcys 


Area forecast discussion 
National Weather Service Cheyenne Wyoming 
320 am MDT sun Jul 6 2008 


Short term...today through Monday night...weak upper ftr moving east-northeast across 
northestern Wyoming...with lingering SW part of upper trough slowly shiftg east across 
S central Wyoming at this time. Looks like main moisture band will continue to drift east 
during the day...but still be over the southeast half of the area during peak 
heating this afternoon. Initial weak surface surge from northern pnhndl storms 
fizzled after midnight...but secondary surge from storms in South Dakota is 
pushing SW across northern third of area. Could still be some patches of 
lower clouds developing along lar range foothills behind surge later 
tonight into early Sun morning. Should be about 5-10 degrees cooler today 
in wake of surface surge...along with some cldyness. Still expecting 
storms to erupt along lar range this afternoon in moist upslope flow and 
then shift east-northeast into the pnhndl late this aftn/eveng. Winds aloft 
not very strong and so don't really expect much in way of severe 
threat...although a few storms will likely kick out some small hail and 
brief heavy rain. Better chance of stronger storms may clip far northern part 
of area in east central Wyoming this eveng...but still looks like better chances 
will be farther north where bulk shear is higher. Rather decent upper 
trough at 250 mb moves into the region tonight...and then shears out 
on Monday just S of area. Looks like better chances of thunderstorms on Monday will 
be mainly in the far southeast part of the region where lingering low/middle 
level moisture remains near high level ftr. Temperatures on Monday about same as 
today for the most part. 


Long term...Tuesday through Sunday July 13th... 


Tuesday/Tuesday night...isolated to scattered afternoon and evening 
thunderstorms will occur along and east of the Laramie range in 
upslope southeast low level regime. Few strong to severe 
thunderstorms not out of the question with decent directional shear 
noted with southeast winds at low levels veering to northwest at middle 
levels. 


Wednesday/Wednesday night...similar setup to Tuesday although middle 
level moisture will be less thus expect less coverage of afternoon 
and evening thunderstorms...with storms occurring further east than 
those on Tuesday. 


Thursday/Thursday night...flow aloft backs to west and strengthens 
which will in turn induce decent surface Lee troughing across 
eastern Montana and eastern Wyoming...effectively drying out the low 
and middle levels of the atmosphere and making afternoon and evening 
thunderstorms much less likely. In fact...significant drying at low 
and middle levels combined with warming temperatures aloft will make 
thunderstorms quite unlikely in the afternoon and evening. Guidance 
high temperatures have the right trend and suspect these will be 
even warmer as this day approaches. 


Friday/Friday night...rather impressive shortwave trough for middle 
July moves across the northern rockies sending a healthy cold front 
southward across the northern rockies. Thus cooler. Since low and 
middle level moisture will remain scant...thunderstorm chances will be 
meager despite cold frontal forcing. 


Saturday/Sunday...low and middle level moisture will increase slowly 
with south winds in the low levels...thus slightly better chances 
for afternoon and evening thunderstorms each day. 


&& 


Aviation...patchy MVFR ceilings mainly between dgw/cys early today... 
then scattered thunderstorms this afternoon at most locations east of the mountains 
ceilings/visibilities in individual storms will likely be lower than storms of 
past few days...still generally VFR though with ceilings of 4-6k feet. There 
will be better chances of a more widespread MVFR ceiling area developing late 
Sun night into Monday morning over the northern/eastern parts...affecting all 
terminals except lar and rwl. 


&& 


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


&& 


$$ 


Long term....Rubin