Issued: 9pm on Thursday, January 18th 2024
Technical Forecast Discussion
Short-Term (Thursday PM 1/18/2024 through Sunday 1/21/2024):
The current pattern of upper-level disturbance is going to bring a surface low through the Ohio Valley into the Appalachians tonight, bringing snowfall and cold temperatures through Saturday morning. A longwave trough moving through is bringing an upper-level jet streak. The left exit region of the jet is positioned so that divergence aloft and PVA are maximized over the region to assist with the progress of the surface low. With the colder temperatures to the north of the surface low in our region, snow will start sometime around midnight and more likely around 1-2 AM EST with some preceding flurries in the late evening on Thursday.
Forecast snow accumulation currently is in the range of 2-4 inches for Athens by Saturday morning, with locally higher amounts with convective snowfall bands. Current model runs suggest a higher snow-to-liquid ratio than the standard 10:1, with consensus in mesoscale models being between 11:1 and 13:1. This means snowfall will be more dry and have higher accumulations than with a 10:1 ratio. The National Weather Service currently has a Winter Weather Advisory valid from 7 PM tonight through 7 AM on Saturday also detailing that the region will see snow accumulations in the range of 2-4 inches. Roadway conditions will likely deteriorate as snow falls, especially where untreated so exercise caution if you do have to be out on roadways mainly on Friday morning.
The main period of snow expected to begin tonight will slow to snow showers by Friday afternoon and evening, and all snow showers will likely taper off by Saturday evening. A somewhat strong surface high-pressure system is expected to build in behind the low parked right over the Ohio Valley on Sunday morning with upper-level ridging. This high will provide some clearing in clouds and dry weather for the time being.
Long-Term (Monday 1/22/2024 through Wednesday 1/24/2024):
The aforementioned high pressure will stick around into Monday keeping things dry, but the next system is expected to bring chances for rain returning on Tuesday and Wednesday. Thankfully, this system will also mean some warmer temperatures, especially compared to what we have seen lately. The CPC 6-10 Day Outlook shows us being in well above average temperatures for this time of year with daytime highs in the low to mid-40s Tuesday and Wednesday as a warm front is expected to move into the region. Southwesterly winds are expected to bring a warm and moist airmass into the region, which will be the fuel for rain showers over this period.
Thursday PM – Saturday PM: Snow showers beginning with surface low, ending Saturday afternoon/evening. Accumulations of 2-4″ expected with moderate travel impacts.
Sunday – Monday: High pressure provides drier weather and some clearing in the clouds.
Tuesday – Wednesday: Chances for precipitation return, but it’s rain!!! Daytime highs in the low to mid-40s expected.