Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service San Francisco Bay area
1037 PM PDT Friday may 29 2015

Synopsis...no big weather changes forecast for Saturday with
coastal stratus spreading inland overnight. By Sunday a system
will approach the coast with a slight chance of showers in the far
North Bay. As the system approaches the marine layer will deepen
and cooler weather will return Sunday afternoon with onshore flow.
Seasonable temperatures and continued dry weather forecast Monday
through the middle of next week.

&&

Discussion...as of 9:00 PM PDT Friday...inland temperatures
finished off the day a few degrees warmer today while areas along
the coast and bays were almost identical to yesterday numbers.
Our Hot Spot again was Parkfield in southern Monterey County with
a high of 96 degrees. However most locations saw temperatures in
the 60s near the coast and bays to 70s and 80s inland. The marine
layer remains around 1500 feet this evening with little change
anticipated through Saturday afternoon.

A robust 3.1 mb gradient from sfo to SAC gradually strengthened
this afternoon and evening to 3.9 mb this last hour resulting in a
moderately strong seabreeze. Similar conditions are expected
again Saturday as the ridge remains in place over the area.

On Sunday the weather pattern is anticipated to change as an
low pressure system approaches the district. This system will
deepen the marine layer as it nears as well as will introduce
a slightly cooler airmass to the region. Patchy areas of drizzle
along the coast can not be ruled out on Saturday as the marine
layer deepens and squeezes out a few drops here and there. A
slight chance of showers is forecast Sunday evening into early
Monday as the remnants of the cold front move through the region.

From previous discussion...
medium range models keep a zonal flow aloft across northern
California through much of next week. Thus...onshore flow will
keep seasonably cool temperatures across the area. Night and
morning coastal stratus will be the norm for the first week of
June.

&&

Aviation...as of 10:30 PM PDT Friday...stratus will be filling in
over the sfo and mry Bay area overnight. Marine layer is compressed
a little as an upper level ridge moves over the area and ceilings are
below 1000 feet. This will result in slightly earlier clearing of the
stratus in the sfo Bay area Saturday.



Vicinity of ksfo...IFR ceilings clearing after 18z.

Ksfo bridge approach...similar to ksfo.

Monterey Bay area terminals...IFR ceilings clearing after 18z at sns.
Low confidence for mry as the ceilings may become scattered in the afternoon
allowing for some brief VFR conditions.

&&

Marine...as of 10:30 PM PDT Friday...winds will decrease tonight
and Saturday as a weak low pressure system develops off the
California coast. High pressure will rebuild off the coast Monday
and strengthen Tuesday and Wednesday for increasing northwest
winds.

&&

Mtr watches/warnings/advisories...
... Bay south of the Bay Bridge until 11 PM
Small Craft Advisory...pt pinos to pt Piedras Blancas 0-10 nm until 11 PM
Small Craft Advisory...pt pinos to pt Piedras Blancas 10-60 nm until 11 PM

&&

$$

Public forecast: CW
aviation/marine: west pi

Visit US at weather.Gov/sanfrancisco

Follow US on facebook, twitter, and youtube at:
www.Facebook.Com/nwsbayarea
www.Twitter.Com/nwsbayarea
www.Youtube.Com/nwsbayarea

National Weather Service Glossary of Abbreviations