Weather Feature Will Have a Mind of its Own
Tue, 30 Apr 2013 02:15:40 GMT —
Last week I discussed the possibility of an upper-level low pressure system wreaking havoc on our temporary warm-up this week.
Now it appears this "temporary" warm-up will last longer than we anticipated.
Upper-level lows are notorious for sitting and spinning over nearly the same area for days, bringing cool and wet weather to a particular region.
So the exact whereabouts of this week's upper-level low is significant to how much cooler and wetter we get by this weekend.
The model solutions vary widely with what's going to happen with this upper-level low that's forecast to cut-off from the main jetstream.
And a wide spread in model solutions is typical with this type of weather feature since they're cut-off from the main jetstream and can drift as if they have a mind of their own.
One forecast model, the ECMWF (or European), has the low near Joplin, MO on Friday morning and takes it to near Munising, MI by Monday morning (image-1).
Another model, the GFS (or Global), also has the low near Joplin, MO on Friday morning.
However, the GFS sees the low wobbling east-southeast to near Montgomery, AL by Monday morning (image-2).
So the models are almost literally a thousand miles apart!
If the first scenario works-out, we'll have cooler and wetter weather this weekend (especially on Sunday).
However, the cool-down would be short-lived as that low would continue on it's northeastward path, allowing drier and milder weather to return on Tuesday.
If the second scenario works-out, we may not see much of a cool-down at all.
Instead, the cool and unsettled weather would be found south of the Ohio River while temperatures here remain above average through the weekend and into early next week.
Since the European model has been doing better with long-range forecasts, we are dropping forecast highs into the 60s and 50s with increased rain chances on Sunday and Monday.
But we'll continue to watch the GFS model with respect and keep you posted on any updates to our forecast.