Winter Weather Tonight And Monday
In this morning's discussion, I showed a map of the 2" soil temperatures under sod which have cooled off considerably with this cold snap. Thought a better representation of road surfaces though would be the bare soil temperatures, also at the 2" level, and that is the map on the right, courtesy of the OK Mesonet. Obviously, soil temperatures, roadways, bridges, overpasses and most any other exposed surface will easily be cold enough for wintry weather to accumulate as we go through the overnight and morning time period.
And, all indications continue to support snow moving in from the SW as we go through the night tonight with a gradual transition to a mixed bag of snow/sleet/freezing rain/rain/drizzle during the day Monday. The complicating factor continues to be the strong southerly wind flow of 15-20 mph at the surface and even stronger winds aloft. It is highly unusual for us to get any significant wintry weather because of the warm air advection associated with this type of pattern, but all indications suggest this will be one of those rare events.
So, here is how it looks to shake out. Look for snow to be developing/moving into E OK before midnight tonight, becoming widespread through the overnight hours and gradually transitioning to the wintry mix during the day Monday. Temperatures will be at or below freezing through the night and only reaching the mid 30s during the day. That obviously means there is the potential for slick spots on roads and particularly elevated surfaces for Monday morning. By afternoon, most of the precipitation should have transitioned over to drizzle with the possible exception of the more NE counties where sleet may still be a problem. The more SE counties will probably see the transition to sleet take place earlier so more of an ice problem may occur down there.
In any event, the total liquid equivalent still looks to be on the order of ¼" or so and the amount of that which falls as sleet or rain will obviously have a big impact on how much snow any given location ends up with. Current estimates suggest that it will be mostly snow and the transition to the wintry mix towards the end of the event should be quite light. With that in mind, snowfall totals of 1-3" look reasonable although some isolated 4" amounts will be possible. Not much in view of what we dealt with last winter, but still the most significant winter event so far this year.
Keep in mind, those strong southerly winds at the surface and aloft create additional uncertainty because of the potential for warm pockets that cannot be anticipated in advance and which could change these estimates dramatically.
Also, this is a short term event which is moving through rather quickly. By Valentine's Day, we should have partly cloudy skies and temperatures well into the 40s along with light winds. Wednesday will see stronger southerly winds in advance of another system that will produce highs in the 50s and a decent chance of rain or even some thunder by the end of the day. The rest of the week will be quite mild with highs in the 50s and perhaps even the 60s in time for the coming weekend.
So, stay tuned and check back for updates.