Tuesday, December 25, 2012

Christmas night winter weather update - SNOW!


Very little new information, though showers are developing in the metro and the rain/snow line is inching it's way towards the area as the upper level low moves closer.  Newest model data indicates that forecast snow totals may be on the conservative side, especially in the northern portion of the metro (northern Shelby/Tipton/north Crittenden).  We'll have to see how it plays out. The warning configuration remains the same (see map in the 5:30 update below).  We recorded a comprehensive outlook for the overnight hours at 9:20pm. This should answer most of your questions, including timing, amounts, travel conditions, warnings, etc.:


An updated warning map is shown below.  The National Weather Service has extended the Blizzard Warning south into Crittenden, Lee, and St. Francis counties in AR this afternoon, indicating that heavy snow and high wind will bring greatly reduced visibility in blowing snow overnight.  The warning is in effect from 9pm to 9am.  Snow totals in the Blizzard Warning area will be in the 3-10" range with highest totals in the Jonesboro to Kennett area.  Wind gusts could reach 35-45 mph overnight.

Most of the metro, particularly east of the Mississippi River, is under a Winter Weather Advisory and Wind Advisory with snowfall totals of 1-4" expected and wind gusts of 30-40 mph. Changeover from rain to snow is expected around midnight just west of the river to about 2am in the eastern metro.  Lower snowfall totals are expected in Marshall County, with higher amounts near the river.

For an audio update of what MWN expects in the metro, take a listen below:


Apparently enough of you dreamed of a White Christmas last night to shift the incoming weather system slightly south and it looks like many of us will wake up Wednesday morning to SNOW!

Briefly (as it is Christmas morning as I type this), the southward trend in the computer models beginning yesterday afternoon has resulted in a concurrence of the data and high enough confidence to result in the issuance of a Winter Weather Advisory for all of the metro except Marshall County, as well as a Wind Advisory for the entire Mid-South.  Areas just northwest of the metro, including much of northeast AR and far northwest TN are now under a Blizzard Warning.

What you can expect:

In the metro, look for rain to arrive later this morning and last throughout Christmas Day.  In addition, wind will pick up and become gusty by this evening.  There is a chance of some rumbles of thunder this evening,  mainly to our southeast over northeast and central MS.  Around midnight, low pressure will pass by just to our east and very cold air will spill in on northwest wind beginning a rapid changeover of rain to snow. During the transition, some sleet is also possible, but accumulations would be minor. Snow is expected to fall from the wee hours Wednesday morning until around dawn and then flurries could last into the mid-morning hours Wednesday.

Snowfall totals in the Winter Weather Advisory (including the metro) will generally range from 1-3", though there is the possibility of higher amounts over Tipton, far northwest Shelby, and northern Crittenden Counties.  To the south, an inch is possible in northern Marshall County.  Wind gusts to 30-40 mph overnight could lead to blowing snow and reduced visibilities. Take this into account if you have to head to work early Wednesday morning.

Expected weather impacts from the NWS in Memphis
We'll have more later today on our social channels and probably this blog. Any travel plans to northern AR, far northwest TN, or points north need to be reconsidered in light of significant winter weather.  In addition, severe storms will occur to our south, including the likelihood of tornadoes in Louisiana, central and southern MS, and AL, today into tonight.

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