Scientific Forecaster Discussion

NWS Discussion
			
				

Area forecast discussion 
National Weather Service San Francisco Bay area 
1051 PM PDT Tuesday Jun 18 2013 


Discussion...as of 9:00 PM PDT Tuesday...an upper level low is 
centered just off the Washington and Oregon coasts. A cooler 
airmass over the area caused temperatures to drop another 5-10 
degrees from yesterday over the interior and 2-4 degrees along 
the coast. The marine layer is not identifiable on the feet Ord 
profiler or the Oak sounding as the airmass has really cooled 
aloft. Therefore the stratus will only be areal in coverage 
overnight. 


The upper low will move inland late tonight but the upper low 
will remain over the Pacific northwest through Friday. An upper 
level ridge will build off the California coast Thursday but 
warming will be very gradual due to the proximity of the upper 
low. Temperatures are only expected to get as high as the lower 
90s over the warmest interior locations Friday but should warm 
into the middle 90s Saturday as the upper low moves further east. 
Cooling is expected Sunday and Monday as another upper level 
trough moves through the Pacific northwest. 


Long range models build a strong upper level ridge over The Four 
Corners area next Tuesday and Wednesday which could bring 
significant warming to the inland areas. 


Summer solstice will occur at 5:04z on June 21...which is at 
10:04 PM PDT Thursday June 20. 


&& 


Aviation...as of 10:50 PM PDT Tuesday...an upper trough currently 
swinging through the region has mixed out the marine layer 
resulting in patchy low clouds scattered across the region. Stratus 
will return late and will be patchy in nature resulting in an 
early burn off similar to this morning. A strong onshore gradient 
from sfo-SAC will gradually diminish overnight leading to lighter 
winds across the district. 


Vicinity of ksfo...borderline IFR/MVFR ceilings expected tonight with 
an early clearing anticipated Wednesday morning. A strong onshore 
gradient will maintain gusty west wind around 20 knots with gusts to 
30 knots through late tonight then gradually ease overnight. 


Ksfo bridge approach...patchy broken ceilings around 1000 feet are 
expected to form tonight with an early clearing Wednesday morning. 
Gusty winds will ease overnight. 


Monterey Bay area terminals...IFR ceilings are expected overnight over 
kmry with an early clearing anticipated Wednesday morning. 


&& 


Mtr watches/warnings/advisories... 
... Arena to pt Reyes 0-10 nm from noon 
Small Craft Advisory...pt Reyes to Pigeon pt 0-10 nm from noon 
Small Craft Advisory...Pigeon pt to pt pinos 0-10 nm from noon 
Small Craft Advisory...pt Arena to Pigeon pt 10-60 nm from 3 PM 
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm 
Small Craft Advisory...Pigeon pt to pt Piedras Blancas 10-60 nm 
Small Craft Advisory...sf Bay from noon 
Small Craft Advisory...mry Bay from noon 


&& 


$$ 


Public forecast: west pi 
aviation/marine: CW 


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