Anyone knows why the barometric pressure has a much larger swing in
Pacific Northwest (Seattle) than in New Jersey area? I remember back
in the days when I was flying in NYC area a low pressure day would have
an altermeter setting of something like 2980, and a high pressue day
would be something like 3006. Here in Seattle the altimeter setting
can go from 2940 to 3050 in about two days when a strong system passes.

Is it because of the higher latitude (48 north in Seattle vs. 40 north
in Jersey) or is it because the storms in northeastern Pacific being a
lot more severe? Temperature wise Seattle is very mild compared with
the northeast.

"M" > wrote in message
ups.com...
>
> Anyone knows why the barometric pressure has a much larger swing in
> Pacific Northwest (Seattle) than in New Jersey area? I remember back
> in the days when I was flying in NYC area a low pressure day would have
> an altermeter setting of something like 2980, and a high pressue day
> would be something like 3006. .....

I think there is a little bit of selective memory going on, here.

Without trying too hard, I picked up the weekly data archive from NCDC for
JFK for the first week of January, 2005, and it showed a pressure of 1025mb,
which corresponds to an altimeter setting of about 30.25, a far cry from the
30.06 that you specified as a "high" pressure day.

I am betting that if someone cares to spend the time to analyse the NCDC
files

( ftp://ftp.ncdc.noaa.gov/pub/data/globalsod/2005/ )

....for JFK, for example.... then even higher pressures will be found, and
that the pressure variation is not likely to be all that different from the
SeaTac regime.

On the "low" side, it is possible that Pacific winter storms contribute to a
lower-than-normal pressure regime in the Northwest, but it would take some
analyses of the data to convince me. The Northeast gets some pretty decent
low-pressure-systems, too.



> Here in Seattle the altimeter setting
> can go from 2940 to 3050 in about two days when a strong system passes.
>

29.40 is approximately 995 mb. That is not a really deep low. I know the
northeast occasionally sees lows below 990, even below 980mb (which would
be 28.90) On the high side, 30.50 is about 1032 millibars, not particularly
excessive.


> Is it because of the higher latitude (48 north in Seattle vs. 40 north
> in Jersey) or is it because the storms in northeastern Pacific being a
> lot more severe? Temperature wise Seattle is very mild compared with
> the northeast.
>

Latitude does have a part to play in that, if a serious non-tropical low
pressure system is moving in some west-to-east path.... and then starts to
deepen significantly.... its track will almost always curve further to the
north.... Hence the more northern areas, such as the Gulf of Alaska,
Hudson's Bay, and the Labrador Coast, are often the areas of the lowest,
lowest pressures. At the same time, the northern continental interiors...
the Canadian Prairies, US Midwest.... will be the scenes of the highest,
highest pressures when they get outbursts of the really cold air from the
Arctic in winter.

It could well be that Seattle's storm-track climate provides for more rapid
variability of pressure day-to-day...if so it would be because more
low-pressure-systems are passing by... There are climate studies available
for individual states... some of which are available on the web...and it
would take somebody some poring over those studies, or over the raw NCDC
numbers, to convince me one way or the other.

I'm sure that a few hurricanes.. and winter storms pressing up the coast can
lower the pressure very often on the east coast..

BT

"Icebound" > wrote in message
...
>
> "M" > wrote in message
> ups.com...
>>
>> Anyone knows why the barometric pressure has a much larger swing in
>> Pacific Northwest (Seattle) than in New Jersey area? I remember back
>> in the days when I was flying in NYC area a low pressure day would have
>> an altermeter setting of something like 2980, and a high pressue day
>> would be something like 3006. .....
>
> I think there is a little bit of selective memory going on, here.
>
> Without trying too hard, I picked up the weekly data archive from NCDC for
> JFK for the first week of January, 2005, and it showed a pressure of
> 1025mb, which corresponds to an altimeter setting of about 30.25, a far
> cry from the 30.06 that you specified as a "high" pressure day.
>
> I am betting that if someone cares to spend the time to analyse the NCDC
> files
>
> ( ftp://ftp.ncdc.noaa.gov/pub/data/globalsod/2005/ )
>
> ...for JFK, for example.... then even higher pressures will be found, and
> that the pressure variation is not likely to be all that different from
> the SeaTac regime.
>
> On the "low" side, it is possible that Pacific winter storms contribute to
> a lower-than-normal pressure regime in the Northwest, but it would take
> some analyses of the data to convince me. The Northeast gets some pretty
> decent low-pressure-systems, too.
>
>
>
>> Here in Seattle the altimeter setting
>> can go from 2940 to 3050 in about two days when a strong system passes.
>>
>
> 29.40 is approximately 995 mb. That is not a really deep low. I know the
> northeast occasionally sees lows below 990, even below 980mb (which would
> be 28.90) On the high side, 30.50 is about 1032 millibars, not
> particularly excessive.
>
>
>> Is it because of the higher latitude (48 north in Seattle vs. 40 north
>> in Jersey) or is it because the storms in northeastern Pacific being a
>> lot more severe? Temperature wise Seattle is very mild compared with
>> the northeast.
>>
>
> Latitude does have a part to play in that, if a serious non-tropical low
> pressure system is moving in some west-to-east path.... and then starts to
> deepen significantly.... its track will almost always curve further to the
> north.... Hence the more northern areas, such as the Gulf of Alaska,
> Hudson's Bay, and the Labrador Coast, are often the areas of the lowest,
> lowest pressures. At the same time, the northern continental interiors...
> the Canadian Prairies, US Midwest.... will be the scenes of the highest,
> highest pressures when they get outbursts of the really cold air from the
> Arctic in winter.
>
> It could well be that Seattle's storm-track climate provides for more
> rapid variability of pressure day-to-day...if so it would be because more
> low-pressure-systems are passing by... There are climate studies
> available for individual states... some of which are available on the
> web...and it would take somebody some poring over those studies, or over
> the raw NCDC numbers, to convince me one way or the other.
>
>

I'm sure it's a bit selective memory on my part, but in NW it's very
common in the winter months to have altimeter setting swing from 2950
to 3050 in a day or two, and when the next storm comes in a week, the
cycle happens all over again. I'm pretty sure that you can find such
highs and lows in Northeast if you really look into the yearly records.
However the "normal" cycle from low to high is less dramatic.


Icebound wrote:
> "M" > wrote in message
> ups.com...
> >
> > Anyone knows why the barometric pressure has a much larger swing in
> > Pacific Northwest (Seattle) than in New Jersey area? I remember
back
> > in the days when I was flying in NYC area a low pressure day would
have
> > an altermeter setting of something like 2980, and a high pressue
day
> > would be something like 3006. .....
>
> I think there is a little bit of selective memory going on, here.
>
> Without trying too hard, I picked up the weekly data archive from
NCDC for
> JFK for the first week of January, 2005, and it showed a pressure of
1025mb,
> which corresponds to an altimeter setting of about 30.25, a far cry
from the
> 30.06 that you specified as a "high" pressure day.
>
> I am betting that if someone cares to spend the time to analyse the
NCDC
> files
>
> ( ftp://ftp.ncdc.noaa.gov/pub/data/globalsod/2005/ )
>
> ...for JFK, for example.... then even higher pressures will be found,
and
> that the pressure variation is not likely to be all that different
from the
> SeaTac regime.
>
> On the "low" side, it is possible that Pacific winter storms
contribute to a
> lower-than-normal pressure regime in the Northwest, but it would take
some
> analyses of the data to convince me. The Northeast gets some pretty
decent
> low-pressure-systems, too.
>
>
>
> > Here in Seattle the altimeter setting
> > can go from 2940 to 3050 in about two days when a strong system
passes.
> >
>
> 29.40 is approximately 995 mb. That is not a really deep low. I
know the
> northeast occasionally sees lows below 990, even below 980mb (which
would
> be 28.90) On the high side, 30.50 is about 1032 millibars, not
particularly
> excessive.
>
>
> > Is it because of the higher latitude (48 north in Seattle vs. 40
north
> > in Jersey) or is it because the storms in northeastern Pacific
being a
> > lot more severe? Temperature wise Seattle is very mild compared
with
> > the northeast.
> >
>
> Latitude does have a part to play in that, if a serious non-tropical
low
> pressure system is moving in some west-to-east path.... and then
starts to
> deepen significantly.... its track will almost always curve further
to the
> north.... Hence the more northern areas, such as the Gulf of Alaska,
> Hudson's Bay, and the Labrador Coast, are often the areas of the
lowest,
> lowest pressures. At the same time, the northern continental
interiors...
> the Canadian Prairies, US Midwest.... will be the scenes of the
highest,
> highest pressures when they get outbursts of the really cold air from
the
> Arctic in winter.
>
> It could well be that Seattle's storm-track climate provides for more
rapid
> variability of pressure day-to-day...if so it would be because more
> low-pressure-systems are passing by... There are climate studies
available
> for individual states... some of which are available on the web...and
it
> would take somebody some poring over those studies, or over the raw
NCDC
> numbers, to convince me one way or the other.