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July 23, 2007

SnapshotBusy fire season across the USA this year…running only slightly behind last year’s biggest ever! 
Big changes occuring this evening that threaten to bring "normal" Northwest summer weather back by midday tomorrow at the latest.  I’ll be right back…it’s 11:04pm and I have a weathercast…Now I’m back and it’s 11:12pm.
What’s left of the front sitting offshore all through the weekend finally moved through the area this afternoon.  It was followed by a good push of cooler marine air.  Of course that marine air has much lower dewpoints than the tropical airmass that was sitting over us for the last 3 days.  Twice this weekend I turned on the air conditioner (once in car and once in house), just because it felt too sweaty…not too warm.  So we’re all finised with that.  By the way the models nailed the drop in the dewpoint quite well.  They all showed a quick drop after 00z today (5pm).  Other than some leftover moisture in the morning, it appears that the developing Pacific High offshore will give us nice north and northwest wind all across the region the next few days.  That’s a great pattern for sunny/warmer weather inland with a minimum of low clouds.  The warmest days should be Wednesday and Thursday.
Interesting to note that the general pattern we’ve seen the last week or two will continue for the next week or so.  That would be a strong ridge just to our east and a trough offshore.  Models say the trough will edge closer again this weekend.  At this point it’s only deep enough and close enough for an increase in marine air.  I see no reason to put rain in the forecast.  But there’s no chance of a heatwave anytime in the next 7-10 days either.
A few interesting facts about this weekend that I noted.

1.  We only had .01" rainfall at PDX all weekend…oops.
2.  The baroclinic zone (frontal clouds/rain) were so close to Portland yesterday that it was a mostly cloudy day in Hillsboro but mostly sunny and much warmer out towards Troutdale.  Quite a variance for being so close to a front.
3.  Dewpoint topped out at 65 at PDX late this afternoon.
4.  Overnight low of 68 Sunday AM was NOT a record because we had that 74 last year on the 22nd! (same date).  What’s the chance?  But a very warm night eh?

That’s it…more tomorrow…Mark