Tuesday, January 22, 2019

Tonight - Rain changing over to ice late. Low: 20-24

Wednesday - Decreasing clouds. High: 26-30.

Wednesday night - Partly cloudy. Low: 18-22.

Thursday - Partly sunny. High: 28-32.


Friday - Partly Sunny. High: 30-34.

Thanks to IconArchive.com for the icons!

The main focus of the weather today is the approaching cold front and how it will impact us. For the rest of Tuesday afternoon, look for rain ahead of the cold front. Temperatues will remain above freezing until after midnight tonight. At this time, we will see a change over to light freezing precip which could cause hazards for morning traffic. Little to no accumulation is expected. After that, skies clear out and the sun finally returns but temperatures will still be below freezing. The coldest temperatues are likely for Thursday night as single digits possible. The remainder of the week remains dry.

Forecasters: Hirsch
Issued: 3:00 p.m., January 22, 2018

Technical Discussion (The nerdy stuff we are discussing in class!) 
WPC today recommends a general model blend for the forecast, so went with the GFS as it goes out far enough to lack at the potential for weather this weekend that may be of interest. 

At the start of the forecast period, rain is falling just to the west of KCOU with overcast skies. Temperatures are currently above freezing to start, but that will change. The main focus on the forecast is the chance for freezing precip later tonight. A low sits in southwest MO which will propagate north and east over the next few hours. As it approaches, colder temperatues will start to occur. The greatest chance for ice will be after 06 UTC and persist till before 12 UTC. All 12 Z model runs of the GFS and NAM, along with the 19 Z HRRR and 15 Z SREF continue to paint this picture of ice. During this time as well, 850 mbs omega is maximized with values between 5-8 microbars/s. This is also occurring at the same time as the front is moving through the region. If the cold persist long enough, non-accumulating snow is possible. The limiting factor is the location of the low and the occurance of the dry slot after 12 Z as the cyclone continues to mature and moves off to the east. If this occurs late, snow is more likely, but have gone with a drier approach. The occurance of the dry slot allows for our atmosphere to finally dry out with decreasing clouds allowing for sun to shine in over 10 days. 

Thursday night will be the first clear night after FROPA so temperatures will bottom out. Single digits are possible so slick spots could occur on untreated roads. Evaporative moisture from melting snow will cause a mix of sun and clouds for the rest of the week. Temperatures rebound slightly on Friday, but another approaching system on Saturday bears montioring. 

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