382 
fxus66 kmfr 070359 cca 
afdmfr 


Area forecast discussion...corrected 
National Weather Service Medford or 
859 PM PDT Monday Oct 6 2008 


Discussion... 
no updates will be made to the going forecast tonight as the cold 
front looks on track...as expected. Rainfall has reached south to 
Newport this last hour and should reach North Bend within the next 
three hours. 


Models differ quite a bit on precipitation amounts...with the nam12 
indicating about half of what the gfs40 indicates. Appears current 
forecast sides more with the gfs40...which is likely the correct 
way to go based on satellite...radar trends...and recent model 
performance. 


Latest MOS guidance indicates probability of precipitation of 30 to 40 percent for 
Medford...though both models indicate a few hundredths trickling 
in by noon PDT. Main effect of the front will be a reenforcement 
of cooler weather and higher relative humidities across the region with 
temperatures running at to 5 degrees below normal the next 3 days. 


Inside slider heading in around Thursday is the next feature to 
watch followed by potential offshore flow Saturday through 
Monday. Model guidance has been inconsistent...however...so stay 
tuned for future updates. Lutz 


&& 


Aviation...coast...areas of MVFR ceilings with local IFR 
this afternoon...becoming widespread MVFR with areas of IFR in 
low ceilings and visibility this evening as a weak front moves inland 
bringing light rain. Inland...VFR conditions today...then late 
this evening into Tuesday morning areas MVFR in low clouds and 
light rain will spread inland from the coast to the Cascades in 
Oregon. Areas of mountain obscurations late in the evening into 
Tuesday morning in low clouds and rain showers. Cirrocumulus 


&& 


Previous discussion... /issued 235 PM PDT Monday Oct 6 2008/ 


Short term...the next frontal system is 300 nm offshore. The 
models are in agreement showing a weak cold front moving into the 
coast and inland overnight. This system will bring light rain 
over areas in western Oregon from the Cascades westward. The most 
favored areas for rain will be near the coast and inland over 
higher terrain...especially along the western slopes of the 
Cascades where there is favorable upslope flow. 


Then on Wednesday...there will be a brief break in the active 
weather pattern. Expect dry conditions with mostly clear to partly 
cloudy skies. A thermal trough will develop at the surface over 
southwest Oregon and northern California bringing northeasterly 
offshore flow to the area Wednesday and moderate northerly winds 
offshore. 


Long term...on Thursday into Friday and Saturday...models 
continue to show a north to northwest flow pattern as a trough 
moves down from the north. This will bring cooler temperatures and 
some showery conditions to the area. The European model (ecmwf) continues to show a 
deeper trough than the GFS and keeps the low persisting over the 
area into early Sunday. The GFS is not as deep with the trough and 
moves it east faster. The degree of cooling will depend on the 
strength and position of this low. Of note is that the 12z GFS has 
trended towards the European model (ecmwf) and there is better agreement between 
the GFS ensemble members. So kept with a blend of the European model (ecmwf) and 
GFS. Colder temperature expected Thursday and Friday...then 
gradual warming on Saturday into Sunday. Best chance of showers 
will be from the Cascades east on Thursday into early Saturday. 
Snow levels on the east side are expected to lower to 4500 to 6000 
feet during this period. Cirrocumulus 


&& 


Mfr watches/warnings/advisories... 
or...none. 


California...none. 


Pacific coastal waters...gale watch from Tuesday afternoon through 
late Wednesday night for pzz356-pzz376. 
Hazardous seas warning from 11 am Tuesday to 5 am PDT Thursday 
for pzz356-pzz376. 
Small Craft Advisory for winds until 5 am PDT Wednesday for 
pzz350-pzz370. 
Hazardous seas warning from 11 am Tuesday to 11 am PDT Wednesday 
for pzz350-pzz370. 
Small Craft Advisory for hazardous seas until 11 am PDT Tuesday 
for pzz350-pzz370. 


$$ 


17/17/17