pressure slope

JL · Post by JL » Sat Nov 15, 2003 9:47 am

[smilie=axe.gif]

Once again env. canada pressure slope grid is down...Don't worry though techies will have it working by last thursday...jim...update:nov.23 grid is back,but 9999999999999999 everywhere. ALSO: a north slope was mentioned on a s.e. day. J.l.

JL · Post by JL » Thu Jun 01, 2006 3:38 pm

Sent env. Can an e-mail re: Microsoft VBScript runtime error '800a004c'

Path not found

/marine/pressureslope_e.html, line 63

JL · Post by JL » Mon Jun 05, 2006 12:51 pm

It's back...

JL · Post by JL » Sat Feb 18, 2012 8:43 am

I e-mailed this to Env. Canada this a.m.: "With the influx of $ into Canadian weather prediction is there any chance of resurrecting the pressure slope grid ? (we were told 2 years ago it was to be made bilingual !!!)"

For newbies, the 'Pressure slope' ( http://weatheroffice.pyr.ec.gc.ca/marin ... ope_e.html ) enabled us to numerically observe the pressure change as low pressure moved through our area (like today !) OR as high pressure built (like a N. outflow situation) ... Dave has provided a pressure gradient ( http://bigwavedave.dyndns.org:8080/Rece ... plot36.png ) that we use to predict West winds in Juan de Fuca BUT the Env. Canada ' Pressure slope ' was more encompassing. You may find the book "The wind came all ways" in your local library that explains this better. ( Env. Canada used to sell this & other weather pubs. )

Wingnut · Post by **Wingnut** » Sat Feb 18, 2012 9:03 am

It would be great to have it back but I'm not holding my breath. Maybe they're still learning french.

eastside · Post by **eastside** » Sat Feb 18, 2012 9:08 am

Typical Canadian bureaucrat response. Government edict to EC to make everything bilingual even though minimal unilingual French Canadians in BC. EC probably knew 2 years ago that they would have no money to do it so the service just disappears. If I lived in Shawinigan I don't think I would expect the lake ice depth forecast to be available in English and I'm sure it isn't. EC should bring back the spot forecast they had for the Olympics too.

JL · Post by JL » Tue Feb 21, 2012 10:57 am

Thank you for sending your message to Environment Canada. I realize this is your third message regarding the Georgia Basin pressure slope map and that we replied in August of 2010 that it would be available later that year. Unfortunately, while this product is still in the queue of items to be resolved, other more pressing issues keep popping up delaying the development work needed to produce that product again. We appreciate your continued patience while we evaluate the programming software associated with this product but at this time we don't have an estimate as to when it will be available.

Bernard Duguay
Meteorological Inquiry Specialist

JL · Post by JL » Sun Feb 22, 2015 12:37 pm

5 years & waiting.

Sent another e mail to E.C. today " Any chance of pressure slope data appearing for Georgia basin ? http://www.weatheroffice.pyr.ec.gc.ca/m ... ope_e.html " Quick response: " Hi Jim,
Unfortunately, the Georgia Basin pressure slope map won’t be brought back. This product has been cancelled. "
Bernard
Subject: Re: Environment Canada Ser: E02181W686 NIRT:0005594

jeamer · Post by **jeamer** » Fri Aug 28, 2015 10:00 pm

Shew look at that... this post has been "going" for 12 years! Gotta be a record on this site...

JL, someone, there's gotta be a fairly simple way to at least approximate the pressure slope. Something we can rig up for the site? I remember that one of the stations it used was Smith Island... anyone remember what the other one was?

Alternatively, does anyone have a copy of "The wind came all ways"?

http://www.amazon.ca/The-Wind-Came-All- ... 0660175177

Apparently that's where the calculation came from.

Been a while since I've been on the site. Surfer who moved out to Sooke for a few years, but now I'm back in town chasing windswell. That pressure slope was key for forecasting the classic SE fizzle in the E JdeF and Haro. Good to be back! Still have some old BWD stickers laying around... and a new to me truck to slap em on.

JL · Post by JL » Sat Aug 29, 2015 8:11 am

http://www.amazon.ca/The-Wind-Came-All- ... 0660175177 explains the slope calculation as laying a ruler across the low & reading the change is pressure from the isobar lines. Not a weather station. We use Smith I. & Tatoosh for calculating the gradient in Juan de Fuca: http://www.bigwavedave.ca/RecentData/Pr ... recent.htm I have the best luck with it for West wind.

Welcome back.

jeamer · Post by **jeamer** » Sat Aug 29, 2015 9:27 am

Great, thanks. Watching this SE develop with curiosity. I do recall being able to forecast the SE fizzle with the P.S. among other things, but I'll have to get the hang of it again. All about how that L tracks....

juandesooka · Post by **juandesooka** » Sat Aug 29, 2015 12:51 pm

Smith Island 998.
La Perouse 992.
I guess that explains 50kt+ southeasterly!

JL · Post by JL » Sun Aug 30, 2015 11:11 am

Wind numbers in MPH but impressive: http://cliffmass.blogspot.ca/2015/08/ex ... storm.html East point (Saturna Is.) hit ESE 44 gusting 62 knots @ 11 a.m. & 53 sustained @ noon. Aug. 29 !!! http://www.bigwavedave.ca/latest.php?site=7 Note: Hurricane = 64 knots, 74 mph, 119 km/h. Wind FORCE = velocity squared ... As wind speed doubles FORCE goes up by a factor of 4

Tsawwassen · Post by **Tsawwassen** » Sun Aug 30, 2015 4:32 pm

That explains the massive swell and epic conditions in Boundary Bay yesterday.
I've never seen it like that.

JL · Post by JL » Mon Aug 31, 2015 1:06 pm

Back to the pressure-slope , here is the concept & available information available from Env. Canada: http://www.ec.gc.ca/meteo-weather/defau ... 1&toc=show All we need now is too daily analyze a weather map to calculate the local gradient. A reminder Dave has provided http://www.bigwavedave.ca/RecentData/Pr ... recent.htm for Juan de Fuca as explained here: http://www.bigwavedave.ca/help/PressGrad_help.htm

pressure slope

pressure slope

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