Posted at 5:35 PM on October 9, 2012
by Paul Huttner
Frosty start - Near freezing in the metro Wednesday AM
50s for metro highs through Friday
-10F temps running about -10F degrees vs. average this week
-2.4F October temps vs. average so far in the metro
1" rainfall? Models cranking out 1"+ for parts of Minnesota Saturday
July 24th last 1"+ rainfall at MSP Airport (1.69")
-3.54" rainfall deficit since September 1st in the metro
Saturday thunder? Embedded T-Storms possible in Saturday's system
Wetter pattern ahead? Saturday's rain could be start of a wetter pattern next 2-3 weeks
Chill-tober: Frosty again Wednesday AM
After 16 straight warmer that average months in Minnesota, it appears October is determined to stop the streak.
So far temps at MSP Airport are running -2.4F for the month. With high running about -10F vs. average the rest of this week, it looks like we may be digging a below average temperature hole that we may not be able to climb out of by month's end.
Look for another frosty start Wednesday morning as temps dip to near 32F again in the inner metro core with 20s just about everywhere else in Minnesota.
Highs will struggle to get move past the 50s the rest of the week.
Much Needed Saturday Soaker?
Yes the timing could be better, but Saturday's prospects for rain are welcome for many in drought stricken Minnesota.
The first really decent wrapped up low pressure system in months will spin out of the Rockies and drive toward Minnesota by Saturday. The system appears to have the capacity to tap into some decent moisture from the Gulf of Mexico, and that should help boost rainfall totals.
Right now it looks like the first wave of rain could blossom Friday night, with additional rainfall Saturday...ending early Sunday. The models are indicating there could be enough upward vertical motion ("updrafts") to trigger a few embedded T-Storms within the overall rain shield. A "dry slot" may also develop which can limit rainfall totals on the southern end of the system.
The GFS is putting out 1"+ for some areas near the metro. As always, rainfall totals will depend on the track of the surface low and any dry slot that might develop. At any rate, this looks like the first good chance for widespread, meaningful, soaking rains in months for most of southern and central Minnesota.
Wetter pattern next 2-3 weeks?
The GFS and Euro have been hinting at overall changes in the upper wave pattern over North America in the next 2-3 weeks. If the jet stream sets up right, it could send more frequent low pressure systems spinning toward Minnesota and the Upper Midwest. Monday night's GFS run cranked out an eye opening 4.98" rainfall total for the next 16 days for the metro area. The latest runs have dropped totals to between 1" and 2". The overall notion of a wetter pattern the next 2-3 weeks seems reasonable given the likely upper air evolution.
Stay tuned as we try and nail down potential soaking rainfall totals in model runs in the coming days.