2013 Outlook- Update 20 February

I predicted changes for February 4-8, 11-15, and 17-21.  Here’s the plot of temperatures, rainfall, and mean sea level pressure for the 10 sub-tropical Queensland sites I monitor.  I’ve marked the expected dates for weather changes in green, including the range.Feb 20 actual

All changes were within the time periods I predicted- but I’m not happy with last week.  There was definitely a change on February 13 with cooler, cloudy weather on the coast as expected, but the plot shows a change on February 11 (still within the predicted range) that seems separate.  I missed this one through inattention to small details.  While the rain and pressure matches the predicted event peaking February 19, this was a little earlier too- Tmin peaked on February 16.  Possibly this shows in the data because there was a combination of two separate inland and coastal systems, and a blocking high in the Tasman Sea kept feeding cooler, moist winds onto the coast. Therefore I’ll claim 10 out of 10 correct predictions for the year, and count one missed change on the 11th.

Changes were at the right times but appear to be preceded by ripples.  Was this a chance disruption or is there a permanent shift in timing, perhaps co-incident with the changing seasons (as the indicator I used was the temperatures back in mid-September last year)?  If the latter is the case then we can expect all events for the next couple of months to be a couple of days earlier than predicted.  In any event I am going to keep a closer eye on inland vs coastal parts of the region.

For the rest of February and March, I’m expecting changes at these times (shown in orange in the plot above):

February:

24-25-26-27 February.

March:

I’m having trouble interpreting data for March.  Unstable conditions I think with frequent small changes from 24 February to 16 March.  Is this the rather late wet season?  The monsoon is certainly strengthening again.

Feb 28-1-2-3-4

6-7-8-9-10-11-1213-14-1516– 17-18-19-2021.  ( I think there’ll be 2 major events, 6-11 March and 12-16 March with a follow up on 19 March.)

27-28-29-30-31- 1 April.

Cluttered, isn’t it?   That’s what my “model” tells me.  And to those who say I can’t be wrong because so many days are covered-  I can be wrong indeed if the weather is stable and clear with few changes.  For example if there are no changes/ rain events between March 6 and 21 I’ll be wrong 3 times.    It’s easier to prove me wrong than right!

And indications for July are 16, 21, and 26.

4 Responses to “2013 Outlook- Update 20 February”

  1. cementafriend Says:

    Ken, Once again your forecasts have been spot on.
    I can confirm rain Jan 25 to 29 (216mm 27th), Feb 6-8, Feb 15-20, Feb 22 and now Jan 25, 26 (131mm this morning) and more today
    To this morning we have had a total 993mm for the year – more the double the average for Jan &Feb combined while I thought we would have less than average
    Nothing is exactly the same in the past but the last slightly similar wet period was 1971 to 1974 (when there were floods which many older may remember) In the the period 1893 to 1898 there were also floods but much higher rainfall in summer. Lets hope the rain of 1898 does not repeat in severity.

    • Ken Stewart Says:

      Thanks for your encouragement as always. It’s not over yet- more to come at the end of this week and weekend. I have also made a set of “predictions” to follow assuming a slightly shorter cycle of 156 days which I will monitor. More later.
      Ken

  2. cementafriend Says:

    Ken, you say the forecast is cluttered but is still spot on so far.
    I have 26 continuous days of rain to today the 9th March where I have recorded (8.30 to 9.00AM) little (0.2mm) to large (three times over 100mm, 19th Feb, 26th Feb & 3rd March).rain or showers for a total of 725mm (total ytd 1279mm)
    I want to again encourage you continue and to not listen to those detractors (especially if any at BOM)

  3. cementafriend Says:

    Good forecasting Ken, Further to comment above had rain in gauge 10th to 13th, 18th to 23rd, 25th, 27&28 and 30th&31st, A total of 279mm for the month which is a little over average (266mm over 120yrs)

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