Tuesday, February 19, 2013

Wintry Weather Ahead Thursday

Wednesday Evening Update:

 Forecast continues to look on track for the heaviest, most impacting winter weather to cause problems across Western Illinois and Southeast Missouri starting Thursday morning. Two time periods are cause for concern beginning with sunrise thru the morning commute. The forecast map below shows a light band of freezing precipitation lifting northward across the area. This may make for some slick roads early, especially those untreated.

Winter Weather Types Expected

Once that initial line lifts north, we will be awaiting a secondary push of moisture from the west which will move in by midday and transverse the area until later in the evening. Temperatures will warm just above freezing in most locations by mid afternoon and we will begin to see the switchover to rain and rain/sleet mix to carry us into the evening. Here are a couple of maps to show where accumulations are most likely.

Total Snow Accumulation

Snow accumulation is likely to be confined to Southeast Missouri and Southern Illinois and on the order of 1-2 inches, locally higher as you move closer to St. Louis.

Total Ice Accumulation

Although ice accumulation will be light across the blue shaded area, it will likely cause slick travel, especially on untreated areas. At times, freezing rain will mix with sleet and snow in the morning hours and may lead to some slushiness on roadways.

Tuesday Evening Update:
Wintry weather has its eye on the Local 6 area for Thursday with snow, sleet, freezing rain, and rain (YES, all of them) in play for this particular storm system. The takeaway?? Just be prepared for a few delays on Thursday morning and be prepared to deal with at least some slick driving conditions.

Here are the main elements we are watching that may have us tweaking the forecast a time or two before it rolls into the area Thursday morning.
  • Cold air will be in place as the storm approaches. Any morning precipitation that can make it into the area just before sunrise thru the morning commute will likely be snow, sleet, or freezing rain. Areas impacted by this will include SE Missouri, Southern Illinois counties west of I-57, and Kentucky/TN counties along the Mississippi River.
  • Dry air will also be entrenched along and east of the Ohio River which may delay the onset of any precipitation until later in the day, likely midday or noon. Once the heavier precipitation moves in during the afternoon the area will be split from north to south from snow, sleet, to rain. (See graphic below)
  • We will keep an eye on how this storm behaves over the Central Plains and into the Arklatex. Heavy icing is expected in Northern Arkansas and South central Missouri but the overall storm system is forecast to begin weakening as it moves east. Warmer temperatures are also expected to advect into the area from the south turning much of our precipitation over to rain by late afternoon.
5AM Thursday
10AM Thursday
Noon Thursday
5PM Thursday

10PM Thursday
 Look for additional updates throughout the day on Thursday as the storm moves into our area. We will post updates on Twitter, Facebook, on wpsdlocal6.com and here on the blog.


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