Wednesday, October 18, 2006

Continuing cool through end of October

Those of you looking forward to a return to pleasant mild weather over Southern Manitoba will likely be disappointed over the next couple of weeks. Guidance is indicating that a large scale Artic vortex over Hudson Bay and Northern Ontario will persist through the next two weeks at least, bringing a continuation of below normal temperatures over Southern Manitoba likely through the end of October.  If this occurs, it will mark the first prolonged stretch of below normal temperatures in Winnipeg since May, an indication of how long Winnipeg and Southern Manitoba have been enjoying above normal temperatures this year. At this point, no major storms are forecast over the next week or so over Southern Manitoba, with generally dry but cool conditions. Note that our last El-Nino season in 2002-03 began with the coldest October on record in Winnipeg, but a mild December and January. Perhaps, a similar pattern is developing this year, as a large scale ridge begins to build over the west coast giving pleasant above normal conditions to BC and Alberta this fall, eventually spreading eastward over Southern Manitoba by December.   

2 comments:

  1. Are we breaking any more precipitation records? I'm thinking about longer-term ones like six-month. Its just incredible.. I collected about 42 mm in September and a mere pittance in early August, and that's it. Other than that it's 5 mm here and there, and I don't think it even reaches the soil before evaporating.

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  2. Box..

    Looking at precip stats from YWG airport, Winnipeg has received a total of 194.5 mm of precipitation from April 1st through September 30th for the 6 month period.

    The driest April 1 to Sept 30th period in Winnipeg since records began in 1872 was 1961 with 194.5 mm of rain and 8 cm of snow for a total of 202.8 mm total precipitation. Thus, if you look at total precipitation over the 6 month period from April 1st to Sep 30th, then 2006 is indeed the driest growing season on record in Winnipeg since records began in 1872. If you look just at rainfall, then this year has tied 1961 as the driest on record.

    Either way you slice it, we have been through a historic dry period in Winnipeg. The question is.. will it continue? We haven't had much precipitation this October (only about 10-15 mm so far), and soil moisture levels will be quite dry going into the winter (unlike last year which had very wet conditions before freezeup) If the advertised El Nino develops as predicted, we could be looking at lower than normal snowfall this winter. That would mean a very dry start to next year's growing season, which could be quite a problem for farmers if spring rains fail to materialize. We've had a string of wet years over the past decade.. could we be looking at the start of a new dry cycle??

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