636 
fxus66 kmfr 220900 
afdmfr 


Area forecast discussion 
National Weather Service Medford or 
200 am PDT Monday Mar 22 2010 


Discussion...weak upper level trough will move through northeast 
Oregon today. A moist northwest flow aloft will persist this morning 
which will lead to isolated to scattered precipitation along and 
west of the Cascades and mainly confined to the morning. An upper 
level ridge builds in this afternoon and precipitation will come to 
an end. The upper ridge continues to strengthen and build into 
southwest Oregon Tuesday resulting in dry and warmer conditions. At 
the surface offshore flow develops which will keep skies clear over 
most of the County Warning Area. 


The upper ridge axis shifts east Wednesday as a cold front slowly 
moves east towards the coast. The NAM/GFS and European model (ecmwf) keep 
precipitation away from the coast through Wednesday afternoon. 
Precipitation then reaches the coast Wednesday evening...then 
spreading inland Wednesday night. 


Post frontal showers move in Thursday with a moist west to southwest 
flow aloft. An upper trough remains over the Pacific northwest Friday 
with weak shortwaves moving through bringing scattered precipitation 
mainly along and west of the Cascades. 


The GFS and European model (ecmwf) suggest a progressive pattern is in the works for 
next weekend into early next week. A ridge builds in Saturday... 
then shifts east Sunday with another front projected to reach the 
coast Sunday afternoon. The main challenge in the extended will be 
the timing of each system. 




&& 


Aviation...broken to overcast skies will continue this morning. 
While ceilings are expected to be VFR...the Cascades and Siskiyous will 
occasionally be obscured until 18z. Clouds are expected to be on the 
decrease in the afternoon as high pressure builds into the area. 




&& 


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


California...none. 


Pacific coastal waters...none. 


$$ 


Petrucelli