Fri. Sep 21st, 2018

Summer is back. Plus Climate Change fingerprints.

  • Vancouver Island Inland Sections Forecast - SPECIAL WEATHER STATEMENT IN EFFECT
    Issued: 3:44 PM PDT Friday 21 September 2018

    Forecast Issued 4:00 PM PDT Friday 21 September 2018 - Friday night: Periods of rain. Risk of thunderstorms this evening. Amount 10 to 20 mm. Low 12. Saturday: Showers. Amount 5 to 10 mm. High 15. UV index 2 or low. Saturday night: Cloudy with 60 percent chance of showers. Low 10. Sunday: A mix of sun and cloud. High 18. Sunday night: Clear. Low 6. Monday: Sunny. High 19. Monday night: Clear. Low 6. Tuesday: Sunny. High 23. Tuesday night: Clear. Low 8. Wednesday: Sunny. High 21. Wednesday night: Clear. Low 8. Thursday: Sunny. High 21.

  • Current Conditions
    15.1° C
    -0.7 ° C/hr
    100.82 kPa
    N/A 0.0 km/h
    gusting 0.0 km/h
    95 %
    Rain Rate
    6.1 mm/hr
    Wind Chill
    15.1° C
    Heat Index
    15.1° C
    14.3° C
    8 W/m2
    Last Updated: 16:10:00 PDT
    Click to Refresh or See All Conditions
  • Day Almanac
    Day's Rain
    17.5 mm
    Day ET
    0.0 mm mm
    Rain Storm
    NotAvailable mm
    Civil Rise
    Moon Phase
    Waxing gibbous (91% full)
    Civil Set
    Day Length
    Day High
    16.9° C @ 10:50 Tdy.
    Day Low
    11.6° C @ 06:51 Tdy.
    Day High Rain Rate
    18.3mm/hr @ 00:08 Tdy.
    Day High Barometer
    101.5 kPa @ 00:13 Tdy.
    Day Low Barometer
    100.82 kPa @ 15:43 Tdy.
    Day Low Windchill
    11.6° C @ 06:51 Tdy.
    Day High Heat Index
    16.9° C @ 10:50 Tdy.
    Day High Wind Gust
    S 22.7km/h @ 12:30 Tdy.
    Day High Solar Radiation
    601W/m2 @ 10:13 Tdy.
    Day High UV Index
    2.7 @ 11:49 Tdy.

It is going to feel like full on summer on our final full week before the Equinox and start of Fall (which is at 1:44PM on the 22nd).

It is a tale of the jetstream once again. Our great arbiter of all things weather on our coast will be bent way to the North of us by Wednesday, which should give us some of our hottest temperatures of the summer (low thirties) and may be record breaking for some areas.
(our all time record for September is 35C in 1988)

Here is the jet on Wednesday:

The bottom portion of the kink is forecast to break off and turn into a cutoff low that will swirl into our area on Sunday or so. We shall see if that brings any precipitation or perhaps more thunderstorms.

2012 Climate Change/Anthropogenic Global Warming Fingerprints
When people talk Climate Change they generally mean humanities affect on our climate. The way we are affecting of course, Global Warming by the addition of CO2 to the atmosphere. So Anthropogenic Global Warming (AGW for short) means Global Warming caused by Humanity.

Reuters reported in August:

Drafts seen by Reuters of the study by the U.N. panel of experts, due to be published [this month], say it is at least 95 percent likely that human activities – chiefly the burning of fossil fuels – are the main cause of warming since the 1950s.

That is up from at least 90 percent in the last report in 2007, 66 percent in 2001, and just over 50 in 1995, steadily squeezing out the arguments by a small minority of scientists that natural variations in the climate might be to blame.

So that is the cause. We are the cause.

Causation is one thing, but because the earth is such a complex system, pinning down current effects solely to AGW is hard. Scientists are researching it, and publishing the results. Here is a published, peer reviewed (large PDF), assessment of extreme weather events in 2012 and whether they were caused, or made worse, by us through AGW.

Eighteen assessments were done on twelve different extreme weather events in 2012 by 78 scientists.A good summary is here by weather historian Christopher C. Burt.

1. U.S. Heat Wave of July 2012
(AGW likely to have played a role)

2. U.S. Heat Wave of March-May 2012
(AGW likely to have played a role)

3. Hurricane Sandy
(AGW did not play a role in the storm itself but may make such storms more destructive in the future due to AGW-driven sea rise)

4. September 2012 Arctic Sea Ice Minimum
(AGW played a role although a severe Arctic storm in August 2012 was also a contributing factor)

5. February 2012 Western European Cold Wave
(AGW probably not a factor)

6. Extreme Rainfall Variation in Europe Summer of 2012
(AGW may have played a role along in combination with several other factors)

7. Record Winter Drought on Iberian Peninsula 2011-2012
(AGW most likely played a role “modulated” by the NAO phase)

8. Rainfall Deficits in Eastern Kenya and Southern Somalia 2012 and 2003-2012
(not clear what, if any, role AGW played)

9. North China Floods of 2012
(not clear what, if any, role AGW played)

10. Heavy Rainfall in Southwestern Japan in 2012
(AGW unlikely to have played a role)

11. Heavy Rainfall over Eastern Australia in March 2012
(AGW unlikely to have played a role although warming ocean temperatures a factor)

12. Two-day Extreme Rainfall Event in Golden Bay, New Zealand during December 2011
(AGW may have played a role in so far as increased moisture in the atmosphere)

CITATION FOR COMPLETE REPORT: Peterson,, T.C., M.P. Hoerling, P.A. Stott and S. Herring, Eds., ‘Explaining Extreme Events of 2012 from a Climate Perspective’. Bulletin of the American Meteorological Society, Vol. 94 (9), S1-S74.. Report is here.