028 
fxus65 krev 301007 
afdrev 


Area forecast discussion 
National Weather Service Reno Nevada 
308 am PDT Sat Aug 30 2008 


Short term... 
a very strong fall-like low pressure system will drop out of the 
North Pacific and into the western U.S. Over the next couple days. 
This strong system will bring a dry cold front across the area over 
the Holiday weekend...with temperatures dropping nearly 25 degrees 
from today to Monday. But...before then...we can expect one more day 
of hot temperatures today before the dramatic cool down Sunday and Monday. 


The main story with this system will be the strong winds beginning 
this afternoon and through Sunday afternoon across the eastern 
Sierra and western Great Basin. As the trough moves into the Pacific northwest 
today...southwest winds aloft over our area will increase ahead of 
the jet stream. We can expect to see winds gusting 35 to 40 miles per hour each 
afternoon...with ridges pushing 70 miles per hour by Saturday night and Sunday 
morning. The strong winds will combine with critically low humidity 
Saturday and Sunday...with red flag warnings and lake wind 
advisories in effect both days. These strong winds will affect many 
people throughout the area due to the Holiday weekend. 


As the jet stream sags southward into northern California...winds will peak 
out in Mono and Mineral counties on Sunday afternoon. Wind gusts 
along the Lee of the eastern Sierra in Mono County could see winds 
gusting to 45 miles per hour...with localized gusts to 55 miles per hour. Wind Advisory 
may be needed for these zones if the incoming trough looks stronger 
than forecast. 


We could see some isolated showers and thunderstorms along the front 
as is pushes through the area...due to the strong dynamics and 
frontogenesis expected with this cold front. Although with lack of 
moisture overall...should remain on the isolated side. After the 
front pushes through...winds will switch out of the north and 
northeast...bringing autumn like temperatures to the area. Strong 
cold air advection will drop our temperatures significantly 
sun/Mon...with monday's temperatures only peaking at low 70s in the desert 
valleys and low to middle 60s in the Sierra valleys. Hoon 


Long term...Tuesday through Friday... 


Cold trough to exit the area Tuesday with temperatures rebounding 
back close to near seasonal normals. A broad longwave trough is 
expected to remain over the Pacific northwest into central US with a 
fast moving shortwave to graze far northern Nevada/California late in in the day 
with little impact. Models solutions continue to diverge Wednesday 
through Friday. GFS shifts the longwave trough more toward the 
central US with strong high pressure ridging into the West Coast. 
This would provide a return to above normal conditions. Ec is quite 
a bit different with the trough getting reinforced and a wave moving 
into northern Nevada late Thursday into Friday with another weak 
wave to reinforce the trough late Friday. GFS ensembles have several 
solutions that lean more toward the ec with the operational solution 
being one with stronger riding into our forecast area. Little 
changes made to the going extended forecast until better run to run 
consistency and model agreement. Milne 


&& 


Aviation... 
a strong cold front will push across the region 06z sun - 06z 
Monday bringing strong surface wind gusts today and Sunday of 
35-40kts and ridge gusts in excess of 70kt. Turbulent mountain 
waves will develop to the Lee of the Sierra this morning through Sun 
night. Milne 


&& 


Fire weather... 


Red flag still on track today and tonight with strong winds and low 
relative humidity ahead of the cold front. Still a bit uncertain when winds will 
die down north of Highway 50 late Sat night and Sunday. Will still 
be breezy but length of red flag may be a bit overdone after frontal 
passage. 




&& 




Rev watches/warnings/advisories... 
Nevada...red flag warning from 11 am this morning to 11 PM PDT this 
evening for nvz458. 


Red flag warning from 2 PM this afternoon to 8 PM PDT Sunday 
for nvz459. 


Lake Wind Advisory from 2 PM this afternoon to 11 PM PDT this 
evening for nvz001. 


Red flag warning from 11 am this morning to 8 PM PDT Sunday for 
nvz450-453. 


Lake Wind Advisory from 11 am this morning to 2 am PDT Sunday 
for nvz002. 


Lake Wind Advisory from 11 am this morning to 11 PM PDT this 
evening for nvz004. 


California...red flag warning from 11 am this morning to 11 PM PDT this 
evening for caz270-271-278. 


Lake Wind Advisory from 11 am this morning to 9 PM PDT this 
evening for caz071. 


Red flag warning from 2 PM this afternoon to 8 PM PDT Sunday 
for caz273. 


Lake Wind Advisory from 2 PM this afternoon to 11 PM PDT this 
evening for caz073. 


Red flag warning from 11 am this morning to 8 PM PDT Sunday for 
caz272. 


Lake Wind Advisory from 11 am this morning to 2 am PDT Sunday 
for caz072. 


&& 


$$ 


Http://weather.Gov/Reno