TGEN Yahoo club (and a little more Seattle Weather)
clubs.yahoo.com
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This will be the last weather post on the TGEN
thread, sorry for spamming up the thread folks.
To answer your question in part Walley, and hedge
the foggy forecast a bit in case it doesn't get
terribly bad...
yeah, fog should increase through the week--as we trend
toward weak offshore flow the inversion will lower.
Right now there is still a significant moist
boundary layer--lots of stratus 1-2000 feet and
only local fog tonight, but once we get rid of
that, dense shallow radiational fog, mainly night
and morning hours, will fast develop, maybe late
tonight, probably Tuesday night. This ridge is
exceptionally strong for this time of year--once
the fog sets up, it may not even burn off in the
afternoon unless some east winds can mix down out
of the passes to help dry things up, that does
not look likely.
We actually saw some sun this afternoon however,
more than I'd have expected. Northerly winds aloft
may help to disperse the stratus again tommorrow,
then with the switch to more of an easterly flow
the fog can settle in--Puget Sound does not get
a lot of drying and mixing from east winds this
time of year in easterly flow, sometimes the east
winds just skip right on over, staying above the
inversion.
Right now the inversion is around 2500 feet--the
air is clear above that, except for some cirrus--
that is why we have the stratus under that cap.
Lower the cap, low stratus essentially becomes
ground based cloud or fog.
I can't speak for Sea-Tac policies, never understood
myself how fog could gunk things up so badly with
all the fly by wire technology and such, they probably
have to space out the traffic, and older planes get
locked out with low IFR conditions.
I try to use the MM5 forecast sounding--seems to want
to take the invesion and surface it with decent north
winds aloft, maybe some sunshine Tuesday afternoon
again, not so bad so far.
I guess you could boil all this down to one idea:
Once dense fog forms, it will likely persist,
and you don't need a weather forecaster to tell
you that <g> |
