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fxus66 kmtr 180930 
afdmtr

Area forecast discussion
National Weather Service San Francisco Bay area
230 am PDT Wed Sep 18 2019

Synopsis...a cold front will push across the San Francisco Bay
area this morning before dissipating over the central coast this
afternoon. Light rain rain showers will be possible through midday
across the northern portion of the region with clearing
conditions later in the day. A warming and drying trend is then
forecast for late week and into the upcoming weekend as high
pressure builds in from the eastern Pacific.

&&

Discussion...as of 02:29 am PDT Wednesday...a weakening frontal
boundary continues to approach the North Bay this morning and will
push into the San Francisco Bay area through sunrise. Latest
regional radar data and observations show precipitation rates of
0.01" to around 0.10" of rainfall per hour across northern
California. Expecting similar amounts of precipitation as the
frontal boundary moves southward through the early morning. Rain
showers along the cold front are forecast to dissipate by mid/late
morning as the boundary approaches the central coast. Thus,
locations south of Santa Cruz are less likely to see measurable
rainfall with this system. With this said, the greatest impact to
the region will be the potential for wet and slick roadways over
the greater San Francisco Bay area early this morning.

With some clearing in wake of the frontal passage by this afternoon,
temperatures are forecast to range from the upper 60s along the
immediate coastline to 70s inland. Cannot rule out a few of the
warmest inland locations reaching 80 deg f this afternoon. Overall,
not expecting much of a cool down from this cold front. Similar
temperatures are forecast for Thursday as the core of the mid/upper
level low shifts inland and high pressure begins to build over the
eastern Pacific.

A more robust warming trend is then forecast for Friday and Saturday
as the ridge to the east builds toward the West Coast allowing for
warming temperatures aloft. More widespread 80s are forecast by
Friday across the interior with the potential for lower 90s by
Saturday in the region's warmest inland locations. At the coast, not
expecting much in the way of a marine layer with temperatures likely
to warm into the lower to middle 70s on Friday and middle to upper
70s by Saturday. Locations such as Santa Cruz will also likely see
daytime temperatures reaching into the lower to middle 80s by
Saturday as well.

Temperatures trend slightly lower Sunday into Monday as another
mid/upper level system drops southward into the Pacific northwest
and inland to the east of the San Francisco Bay area. At this time,
dry conditions look most likely with this system with temperatures
remaining near seasonal averages. The operational models are
trending about 5 degrees cooler for Monday compared to the nbm, yet
will not make significant changes at this time. Depending on the
exact track of the aforementioned system, the development of
offshore flow looks possible early next week which may result in an
increase in temperatures and much drier conditions. This pattern
will be closely monitored in the coming days for the potential for
increased fire concerns. It is important to remember that our fire
season is not yet over as widespread wetting rains have not occurred
across our region.

&&

Aviation...as of 10:28 PM PDT Tuesday...VFR, however satellite
imagery is showing patchy low clouds developing and cloud cover is
forecast to increase overnight. Gusty west to northwest pre-frontal
winds in the hills of the North Bay and East Bay resulting in low
level wind shear ksts and klvk tafs until 14z Wednesday. An advancing
cold front from the northwest brings showery weather early Wednesday
morning, tending to diminish as the band of showers moves south and
east.

Vicinity of ksfo...VFR, lighter west wind with increasing cloud
coverage overnight and Wednesday morning. A few showers possible
Wednesday morning.

Sfo bridge approach...similar to ksfo.

Monterey Bay terminals...VFR, winds light from the southeast tonight.
Few to scattered clouds Wednesday, isolated shower possible.

&&

Marine...as of 8:38 PM PDT Tuesday...light to locally gusty west
to northwest winds will prevail over the waters through the
middle of the week. The strongest winds will be generally confined
along and south of the coastal points, as well as through the
coastal gaps and over the bays. A front will move through tonight
and Wednesday bringing a slight chance of showers to the northern
waters. Northwesterly winds will increase at the end of the week.
Mixed seas will continue with a moderate period northwest swell
and a light southerly swell.

&&

Mtr watches/warnings/advisories...
... Pinos to pt Piedras Blancas 0-10 nm until 9 am

&&

$$

Public forecast: rgass
aviation: canepa
marine: Rowe

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