Warm, Windy Weekend Along With A Good Chance of Rain.

Thought I would take a moment to illustrate the enormous swings in the computer model solutions over the last couple of weeks leading up to Christmas.  With the widespread use of the internet, anyone with a computer has access to computer solutions of various atmospheric parameters for as much as 384 hours into the future; i.e. the GFS.  The problem is that the longer the time horizon, the greater the likelihood of solutions that have very little chance of actually verifying.  As a result, the unlimited access to this data can lead to very misleading conclusions regarding what the weather will actually be like at some point in time in the future.

For example, this first graphic is the GFS solution that was initialized with data on Dec 16, at 6PM and depicts the solution it has derived from that initialization that would be valid at 6PM on Christmas Eve.  The solid blue line typically delineates the rain/snow line so this solution has a very strong low pressure system in W Kentucky with strong northerly winds over E OK and is depicting very heavy precipitation which would be in the form of snow.  If that were to verify it would mean a lot of snow falling at that time which would imply a lot of snow on the ground the next day and certainly a White Christmas for us.  That solution in varying forms was evident for several model runs during that time frame.

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However, that solution began to change with later model runs to something more like what we see now on this next graphic which is also from the GFS but with data initialized this morning and also valid at 6PM Christmas Eve.  Obviously, there is no comparison as the more recent data run clearly shows us with a strong southerly fetch and therefore very warm conditions with no chance of snow.

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The reason for the difference in model solutions is complex and will not get into to all the nuances in that regard.  Suffice to say whenever you hear of a specific forecast two weeks or so out that is calling for something that dramatic, take it with a huge grain of salt.  That is not to say that the guidance is always wrong that far out but those solutions need to be carefully evaluated from one run to the next over a period of several days to establish trends and a level of confidence that something that significant might actually occur.

As mentioned, the latest/greatest data continues to suggest a very mild Christmas weekend along with increasing chances of rain/drizzle/showers/storms.  As you can see here, we will have a good shot at some light rain for mid-day Friday, there could be some lingering showers or drizzle during the day Saturday, but the best chance for showers/storms still looks to be later on Christmas Day itself.

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For tonight, a return to southerly winds will keep us above freezing so no threat of any icing issues.  Overcast skies and occasional rain/showers will hold us in the 40s for Friday, not much of a cool-down Friday night, lingering cloud cover and possible drizzle for much of Saturday but stronger southerly winds will bring us into the 50s.  In fact, those southerly winds will likely result in temperatures continuing to rise through Saturday night and we expect to be in the 60s on Christmas Day along with widespread showers/storms.

After that, much of next week will have a more settled pattern in place with some minor ups and downs in temperature and rain chances as you can see on our forecast page. 

In fact, the 8-14 day outlook continues to suggest temperatures, on average, should be running above normal heading into the New Year.  Currently, we are not seeing any indication of any arctic air returning to the state anytime soon.  That time period will also have the potential for at least some precipitation.

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In the meantime, stay tuned and check back for updates.

Dick Faurot