Friday Weather Briefing: Very cold weekend coming up, then awaiting the next storm system

Good Friday morning to everyone…we’re putting the wraps on a very cold first week of 2018 across the Western Carolinas and we look to continue that trend over the next few days.

 

As you head out the door this morning temperatures are in the single digits and teens with sunshine and a northwest wind that is dropping wind chills into the single digits in the Piedmont to below zero in northwest sections of the coverage area near the Blue Ridge.

 

High pressure is slowly dropping down from the Northern Plains today and it is continuing to advect cold air into the region. Even with sunshine today temperatures will be slow to rise. Your Friday afternoon high’s will range from the mid-upper 20’s in the foothills to  near 30 degrees in a few localized spots across the Western Piedmont.

 

Winds will start to decrease later this morning and more so tonight across the lower elevations. With near-calm winds and clear skies radiational cooling will be very efficient for tonight. Expect a quick fall-off after sunset and it will continue through the night with single digits to low teens expected again tonight.

 

By Saturday morning high pressure of about 1038 mb will be located across Illinois and quickly moving eastward toward the Ohio Valley and eventually the Mid-Atlantic. Meanwhile out west a piece of energy will be moving on-shore during the day on Saturday near the Washington and Oregon coastline. It will move east and drop through the Rockies before emerging out across the Southern Plains on Sunday.


 GFS Surface Pressure 7 am Saturday

GFS Surface Pressure 7 am Saturday

 

 

Here locally expect another cold day but possibly a degree or two warmer compared to Friday. Upper 20’s to Low 30’s are expected with another chilly night for your Saturday night (teens likely). On Sunday we begin to see the makings of a weather system that could have some impact on us for the start of the upcoming work week. A 1036 mb high centered over the Delmarva will very slowly begin to slide off the Mid-Atlantic coastline.

This high has done the dirty work in delivering a lot of cold, dry air into the Western Carolinas. High’s may get above freezing on Sunday but clouds and moisture will increase both as a response to the high sliding off and a developing upper low coming through the Southern Plains and eastward.


 GFS Surface Pressure (Sunday 7 am)

GFS Surface Pressure (Sunday 7 am)

 

Precipitation through the day Sunday will increase starting in Texas and Oklahoma will traverse through the Mid South late Sunday and then into the Southeast on Monday. There is growing concern that moisture will interact with the leftover arctic air mass starting Monday morning. Dewpoints are going to be very low (single digits) before the atmosphere moistens up. Then come daylight Monday that precip could be reaching the ground in or nearby the coverage area.

 

 This is lining up as a classic in-situ CAD event where mixed precipitation types are possible especially in the  favored CAD region along the Blue Ridge to I-40 corridor. That said all counties are still in play for some mixed precip Monday morning.

 

Precip will continue at varying rates through the day Monday and into Monday night as a surface low develops in the Deep South along with the upper dynamics. The big question is…just how fast will the airmass moderate enough to eliminate frozen precip types? That’s still up for debate, current model guidance suggests temps getting above freezing by lunch time. However climatology would tend to lean against that quick of a recovery.

 

We’ll continue to monitor this situation and post more as we get closer…we have released the Winter Storm Index and placed it at Level 1 (Social Media Talk). An updated look at the index will likely come this afternoon.

 

Daniel Crawley

Foothills Weather Network