The Week Ahead: Wintry Start / January Thaw to Finish

Winter Weather and Freezing Rain Advisories are opening the week across the eastern district and those advisories will run through 6-9AM Monday morning.  That means they’ll impact the morning commute.  This will be a medium impact event.

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Here’s a look at the areas under the freezing rain advisory (pink) and the winter weather advisory (purple):

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Remember that ADVISORIES are issued for events which cause disruption to travel and hazards to safety.  Accumulations of ice are expected to be 1/4″ or less. 1/4″ or more of ice would warrant an ice storm warning.  It only takes a little ice to cause big problems.. especially on bridges/overpasses as well as rural and untreated roads.  Temperatures at mid afternoon are right around freezing, but it has been a very cold week with subfreezing ground temperatures.  That means although the rain on your car or windshield may not be frozen, it roadways may well be — and it will be one of those situations where you can go from wet pavement to black ice — so use caution.

Radar is showing a mix of rain and freezing rain over the east and that will continue to be the case this afternoon and tonight.

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This will be the only weather system of note this week as we settle into another extended period of rainless (and snowless) weather which will take us to next weekend.  For snow lovers this winter continues to offer slim pickings with no major winter storms to date — snow totals are running slightly below to well below average.  We’re getting close to 11 months since we had our last winter storm watch issued for any part of the east or western district:

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Prospects for significant snow are not good for the next week as shown by the three major models running out that far:

2015-01-11-1300-12ZECMWF-HSFC-TSN-CEUS-H168 2015-01-11-1300-12ZGEMHR-HSFC-TSN-CEUS-H168 2015-01-11-1300-12ZGFSHR-HSFC-TSN-CEUS-H168

Although things currently can (and do change) in the model world, there is nothing showing up through around the 21st of the month at least at this time in terms of major snowfall (or rain for that matter).

Forecasting will then become a temperature issue.  We’re in for one final cold snap of this go round.  The upper ridge which has been parked over Alaska and NW Canada since the month began is still in place.  Although the direct-north to south flow has taken on more of a track eastwards through the lakes which will take the worst of the cold well to our north and east. Tuesday and Wednesday we’ll see temperatures a bit below average– teens for lows and 20s for highs — it will be nowhere as cold as last week.

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By late in the week and NEXT weekend, that ridge is gone and Pacific flow has taken back over (similar to December) and the cold air is shuffled off through Quebec. We don’t have snow on the ground, and it has been very dry (overall) so it won’t take much to allow us to maximize this mild flow and warm to much above average temperatures.  Highs will warm back to the 45 to 50 degree range.  The biggest unknown is if we get stuck with a lot of cloud cover which would bring up overnight lows and bring down daytime highs.

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Warming may tend to be maximized out west where the western district is more under the influence of downslope flow from the Rockies. Already mild Pacific air is further dried and warmed in it’s trip over the high terrain of the western U.S. and then into the progressively lower Plains and Midwest further east.  The warming effect is greatest over the western High Plains just east of the Rockies and lessens further eastward as the air is modified by the cooler ground it travels over.  For this reason, some low to mid 50s can’t be ruled out over the western district from KC westward next weekend.

newrainshadow_extend-NOTATED_WITH BOXES

CROSS SECTION

A final note..we did set a record this past week– it was cold..but it wasn’t that type of record.  The Arctic high which sank into the region midweek brought very high atmospheric pressure.  Nearly 1056MB at the center.

2015-01-07-1800-USSFCMAP

That brought home barometers to over 31″ of mercury in the KC area, setting a record high pressure level at the KC International Airport.

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That’s it for this week.. not much to talk about in the blog weatherwise this week so we’ll get another weekly update done this time next week as we look forward into late January.  Monitor local media for the latest on the Sunday night/Monday morning ice in SEMO/SW IL and STL.

 

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