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fxus65 kbyz 240832 
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Area forecast discussion 
National Weather Service Billings Montana 
232 am MDT Thursday Jul 24 2008 


Short term...valid for today and Friday... 


Active weather pattern today as convection will once again 
develop over the forecast area. Thunderstorms continued most of 
the night across the northwestern zones in response to upper 
trough moving across southern Canada. Energy associated with the 
upper trough with additional lift from jet rounding the base of 
this trough were bringing the isolated convection. Unstable air 
mass over the area this afternoon with the deepest instability 
over the southeast zones. Preciptable water over an inch today 
with cape prognosticated over 1500 j/kg. Another short wave approaching 
the area this afternoon which will keep easterly upslope flow 
going across the region for a chance of scattered thunderstorms. 
Will mention a chance of severe over Powder River and Carter 
counties today where best dynamics will be position. Main threat 
from these storms will be hail and wind. Also a potential for 
some very heavy rain as 700mb flow is very weak. Thunderstorms 
decreasing during the evening as short wave ridging builds in 
from the west. Although ridge is building into the area 
Friday...models continue to bring weak channeled vorticity across 
the area. Still enough moisture remaining around to bring a 
chance for isolated storms. 


Temperatures remaining near seasonal today in the middle 80s but 
will rise to above seasonal averages on Friday as surface thermal 
ridge begins to move in from the west. Should see afternoon 
temperatures in the upper 80s to lower 90s across the forecast 
area. Richmond 


Long term...valid for Sat...sun...Mon...Tue...Wed... 


Medium range models continue in good agreement through the period. 
Upper ridge amplifies over area on Saturday leading to a hot 
day...before upper flow flattens in response to weak shortwave 
trough rippling across Montana on Sunday. This is expected to cool 
daytime highs Sunday just a few degrees from saturdays highs. 
Another shortwave trough moves across Montana on Monday and 
flattening upper ridge even more...which should trim high 
temperatures a few more degrees on Monday. Flow remains fairly 
zonal on Tuesday...before ridge rebounds Wednesday and Thursday. 
Have left temperatures at or slightly above climatological norms 
for early to middle of next week. 


Reduced threat of precipitation on Saturday as ridge is firmly in 
place and monsoonal moisture does not appear to return as a 
player. Remainder of period reflects threat of isolated 
thunderstorms each day associated with weak shortwave troughs 
rippling eastward across the area throughout the period. At this 
point does not appear that monsoonal moisture will make another 
surge northward...but will warrant watching. Meier 


&& 


Aviation... 


VFR conditions will prevail through the next 24 hours. Isolated 
thunderstorms may develop late this afternoon and early 
evening...mainly from Billings east...with VFR conditions. 


&& 


Preliminary point temp/pops... 


Today Friday Sat sun Monday Tuesday Wednesday 
------------------------------------------------------- 
bil 087 059/089 060/097 065/094 064/089 062/089 062/089 
2/T 22/T 22/T 22/T 22/T 22/T 22/T 
lvm 086 048/087 052/095 055/092 054/088 052/088 053/088 
2/T 21/u 12/T 22/T 22/T 22/T 22/T 
hdn 090 058/090 060/099 065/096 060/091 060/091 061/091 
2/T 22/T 22/T 22/T 22/T 22/T 22/T 
mls 086 059/089 061/097 067/095 064/091 063/090 064/090 
3/T 22/T 22/T 22/T 22/T 22/T 22/T 
4bq 087 059/087 061/098 065/093 061/089 061/088 062/090 
3/T 32/T 22/T 22/T 22/T 22/T 22/T 
bhk 084 055/087 057/094 060/089 059/088 057/088 062/088 
3/T 22/T 22/T 22/T 22/T 22/T 22/T 
shr 086 054/086 056/097 059/091 055/087 056/085 057/089 
2/T 32/T 22/T 22/T 22/T 22/T 22/T 


&& 


Byz watches/warnings/advisories... 
Montana...none. 
Wyoming...none. 


&& 


$$ 
Weather.Gov/Billings