Monday, January 27, 2020





Monday Night- Partly cloudy. Reduced visibility due to fog, with possible freezing fog. Low: 28-32


Tuesday - Cloudy. Fog overnight. High: 32-36


Tuesday Night - Cloudy. Snow Flurries after midnight. Low: 28-32


Wednesday - Overcast. Snow in the morning hours. High: 30-34


Thursday - Mostly cloudy skies. High: 32-36


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Discussion: 
A majority of the morning fog has cleared and will remain relatively constant until the night hours. The fog will build up once again, severely impairing visibility but will begin clearing in the late morning. Things will remain calm until Tuesday night into Wednesday afternoon when the chance for snow increases. Saturation and temperature will be hanging around ideal values for a possibility of less than an inch of snow. The chance for snow will clear, leaving behind clouds into Thursday.
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Forecasters: Owens, Savoy, Travis
Issued:  5:00PM January 27 2020

Technical Discussion (The nerdy stuff we are discussing in class)

The long-wave pattern on the 300-mb chart is primarily zonal, with a finger of the PFJ over central Missouri. The jet finger is merging with the STJ over the panhandle of Florida. This reflects to the 500-mb level, with a tight pressure and thermal gradient over central Missouri. At the 850-mb level the gradient becomes loose, with north-westerly winds, helping to bring in CAA and keep temperatures low. This continues to reflect to the surface level high and will continue to bring northerly winds throughout the short term forecast. With this the upstream SKEW-T is Topeka, Kansas and is showing saturation in the lower levels, with an overall stable atmosphere.

The models of choice for this forecast is the NAM, RAP, SREF and HREF. This is due to the models verifying semi-well with current conditions. NAM needs minor adjustments to temperature, in particular the SKEW-T.

In the short term forecast, Monday night until Tuesday night, there is little to be expected. With northerly flow, lower temperatures and high RH values the primary threat will be fog and freezing fog development. METARS are currently showing 5sm in visibility at Columbia Regional Airport, and with high pressure there is no reason, not to believe that this trend will not continue. As such the current mist will thicken overnight and with temperatures following a diurnal pattern, there will be a repeat of Freezing Fog.

On Tuesday night into Wednesday, condition will degrade as snow is expected to move into the Columbia area. HREF is showing a weak low pressure, degrading into a trough, moving from New Mexico across Texas and Arkansas, over the next few days. While air in the mid level (700-mb and 500-mb), and the lower levels will still be cold and saturated from the snow still on the ground. The upper and mid levels will continue to become more saturated as Tuesday night transitions into Wednesday morning, and the column remains frozen throughout the time period. While the SREF and HREF are not showing any major precipitable water values, they show up to an inch of snow fall. Without any major lift, indices are showing Omega > -3 ubars/s at less than 10%, any snow fall will mostly be flurries and little accumulation will occur.

For the long term forecast, the SREF is showing the long wave pattern returning to a zonal flow in the mid and upper levels. In the lower levels high pressure will return and with little moisture, conditions will become overcast, however there will be a possible fog threat.

2 comments:

  1. Great forecasting. I love all the technical info you posted. Very interestin . Thanks!!!

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  2. Great to see your forecast blog back on line after the holiday break! Snow coming again!!

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