Seems like every day in recent months, the forecasted high temp in
Seattle is 5-10 degrees below what it actually turns out to be. And
these are forecasts from just the day before. Today's forecast, for
instance, was for a high of 75. It's now 86. Any idea why this wide
variation?

Jim Becker wrote:
IMHO....the 'weather folks' are relying way too much on computer
models. Seattle probably (I grew up there as a child) has folks who
came there from somewhere else. They spend most of their time with
the latest super duper dopler radar when they should go back to basic
forecasting. I remember a guy there in Seattle who used an easel
board and magic markers and drew cartoons and he made better sense
than most of what they have now.

Heck JP Patches could do a better
job. It's sorta like a dying art, I suppose. If you get cable and
are able to view WGN, the folks on there do a decent job using both
computers and they have the knack to add their own 'guess' and make
it sound reasonable.

We get the same thing here in Norfolk, Va. Our biggest problem is
tied to the ocean and the NWS thinks everyone lives at the airport.

Just my 2 cents.

The names Bob Cramm and Bob Hale come to mind for the cartooning Seattle
weathermen (he said, dating himself...) And Ray Ramsey, who could
squeeze a lot of information into what sounded more like incoherent
rambling to most folks...

We did spike an official 84° at SEA Momday, but think it was because we
got a bit of SE down-sloping off the mountains into the Puget Sound
basin just ahead of a weak front that brought a marine push in later
that evening. It's been a kinda weird summer so far in Seattle - quite
dry and warm; we just broke a record for longest stretch of days with
high of 70° or above - 50 days, and we may well make it to 60+ the way
it looks...

I'm ready for a nice wet fall and winter; getting way too dry out, and
our idiot smoking drivers are starting grass fires along the Interstate
daily. At least we've been spared the terrible wildfires folks a little
ways north in BC are dealing with...

Bob ^,,^




"Steve" wrote in message
news
Seems like every day in recent months, the forecasted high temp in
Seattle is 5-10 degrees below what it actually turns out to be. And
these are forecasts from just the day before. Today's forecast, for
instance, was for a high of 75. It's now 86. Any idea why this wide
variation?

I can't speak specifically for Seattle, since I am not familiar with the
operations of WFO Seattle, but I can attest to the general trend in the
NWS forecasts. Not that long ago, forecasts were prepared in text format
for zones, which basically meant forecasting for whatever ASOS stations
happened to be in those zones. Recently, the graphical forecasts have
changed that. While the ZFPs are still issued, they are generated based
on the graphical grids that the forecasters prepare.

Of course, verifying a forecast can still be fairly tricky. The location
of the nearest ASOS station in relation to where you are can make a big
difference in how well the forecast does. The high at the airport may be
86, but that doesn't necessarily hold for other parts of the region.


Ben

==========================
Benjamin J. Cotton
LDM/Forecast Game Administrator
Department of Earth and Atmospheric Science
Purdue University
Staff Meteorologist, WCCR

(502) 551-5403 (cell)

Steve wrote:
Seems like every day in recent months, the forecasted high temp in
Seattle is 5-10 degrees below what it actually turns out to be. And
these are forecasts from just the day before. Today's forecast, for
instance, was for a high of 75. It's now 86. Any idea why this wide
variation?

Forecasting the high temperature near a coast during summertime is
inherently very tricky. So much depends on whether or not a sea breezes
reaches your location, which in turn depends very strongly on (a)
whether there is an offshore pressure gradient and how strong it is, (b)
your distance from open water, (c) local topography, and (d) countless
other subtle factors that are difficult or impossible to accurately
account for in a computer forecast model. Sounds like the forecasts
were anticipating an onshore flow that didn't kick in quite as hard as
expected. Or maybe you are a mile or three more distant from the water
than the forecast was written for.

I used to live in San Diego, where the temperature could be in the 70s
right on the coast and over 100 just 10 miles inland. The precise
position of the boundary between the two airmasses was impossible to
predict accurately on any given day. But at least in that case, the
official forecast would say something like "70s on the beach, 90-100 at
inland locations", leaving it to you to figure out where you fell
between those extremes.