Snowcast Event 8 – Update 5a – 7:38 a.m., Mon, Feb 8

Quick update to adjust snow totals slightly.  Still a broad area of 1 to 3 inches expected across much of northern and western Oklahoma.  Adjusted the more significant amounts of 3+ inches to an area of banding that has become established from near Cordell to near Okarche.  Latest RUC – and some previous NAM/GFS runs grabbed this feature well and it should shift northeastward during the afternoon.  Already 1.2 inches of snow in Okarche since it began at sunrise…

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Snowcast Event 8 – Update 5 – Midnight, Mon, Feb 8

I’m selling… There is becoming less and less support for significant snowfall associated with this system.

Some larger amounts of precipitation are expected tonight and tomorrow over southeast Oklahoma… in the warm sector… however, I am now expecting less in the cold sector lending to much lower snowfall totals than previously forecast.

Current thinking is that there will be a burst of snow develop over the Texas panhandle near sunrise… that surges eastward across the northern part of Oklahoma.  Lack of sufficient cold air in place ahead of the storm combined with lesser amounts of precipitation will keep snowfall totals generally less than 3 inches.  Between Noon and 6 p.m. – expect snowfall rates and wind to create blowing and drifting snow in the higher impacted areas… but conditions should rapidly improve near Midnight.

It still would not be out of the question to see an isolated area get upward of 5 inches.  The most reasonable zone for this to occur from Roger Mills and Ellis Counties – eastward to Kingfisher County to Tulsa to near the Arkansas/Missouri border.  Bottom line… this storm just doesn’t appear to have what it takes to be a significant one.

Cold air will still filter in behind the front on Monday… making conditions less comfortable than what we have dealt with over the last few days.  No need to rush to the store early on this one folks…

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Snowcast Event 8 – Update 4 – Noon, Sun, Feb 7

There are amazingly few differences between the morning GFS and NAM regarding the key players in Oklahoma’s weather over the next couple of days.  Light precipitation should start to break out to our west and south by sunset tonight… becoming more widespread near midnight and rocking along pretty nicely by daybreak Monday.  This will be in response to several lifting mechanisms – but most notably, the southwest U.S. system that will be approaching the state.

Also by daybreak Monday… colder air will have started working into the north and northwest portions of Oklahoma.  Snow should already be occurring in the Panhandle and possibly across the northern one to two tier counties of the state.  The change over to snow line will then start making steady progress southeastward – exiting the southeast corner of the state a few hours after sunset.

This quick moving – open wave – will definitely cause some problems with its associated precipitation falling in frozen form.  But… it looks far from a record event.  Model solutions are generally squeezing out around a half of an inch of liquid / or melt-down / totals across the state.  The GFS has come in this morning with a slightly higher swath from southwest to northeast – just to the northwest of OKC.  If it was all snow… 6 to 8 inches would be possible.  There will be some areas that spend much of the precipitation time as rain or a rain/snow mix.

For sure it will be getting colder and quite windy.  Any area seeing snowfall of more than a couple of inches will likely see considerable blowing and drifting – with reduced visibility.  There are likely to be travel issues anywhere north of I-40 until the precipitation ends and road crews are able to address the situation.

For the Okarche/Oklahoma City area… we once again have the “good fortune” of falling right on the line of slightly impacted (couple of inches)/very much impacted (5 to 6 inches).  And once again, we will likely have to wait until the event starts unfolding about 24 hours from now to see which side we are going to fall on…

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Snowcast Event 8 – Update 3 – Midnight, Sun, Feb 7

Little in the way of difference tonight between the GFS and NAM with regard to mid-level features.  System moving through southern California will continue to advance fairly quickly eastward with lifting spreading over the high Plains by sunset Sunday.  There is virtually no difference in position or timing of the strong mid-level low that will be dropping southward through the north central U.S.  This feature will be the trigger for the southward advance of cold arctic air.

The arctic air will spill into the state during the day Monday… changing precipitation over to snow in the north and west with the snow line rapidly moving eastward during the day.  It appears that this will be a fairly wet system… however; most of the heaviest precipitation will be confined to the shrinking warm sector over east central and southeast Oklahoma.

Don’t believe that there is much reason to change from the previous update which reduced snowfall totals.  This will be a quick moving system – with change over to snow taking a bit of precipitation time – meaning that any one area may only see snow for about six to eight hours.  Even at one inch an hour snowfall rates… areas with the highest totals should only see about half a foot of snow.  About the northern third of the state looks like the best bet for that to occur.  A decent covering with one to three inches will be found south of this area covering all but the southern third of the state.

A period of strong north to northeast winds will exist during the event and for a short time after… creating blowing and drifting snow with reduced visibilities.

Snowcast Event 8 – Update 2a – 5:46 p.m., Sat, Feb 6

A bit of an odd update here.  There hasn’t been a great deal of change in the overall situation… and it might be prudent to wait until the evening models show up… but I have decided to make a fairly large update to the previous forecast.  Lowering overall snowfall totals.

There are a couple of things that are fairly certain about this storm.

1) It will become cold

2) It will become windy

3) There will be some snow

BUT… despite all of this creating some rather unpleasant conditions… I am having serious concerns as to just how bad this system will be.  This does not have the appearance of a typical heavy producing snow event in Oklahoma.  Especially central Oklahoma.  This will be a quick hitting storm with the cold air hitting about the time precipitation is already in progress.  Not long after the snow gets going… it’s going to be exiting the eastern part of the state.

A quick hitter of this nature shouldn’t produce much more than a half foot of snow in the hardest hit areas.

Effectively, this has reduced the amount of snowfall expected in the OKC metro area to around 1 to 3 inches… slightly more on the north sides.

Gut feeling, pattern recognition – don’t know… but I didn’t like the 4 to 6 inches in the ongoing forecast for OKC.  Call this a bit more of a trim than a haircut… but thought a late afternoon update was warranted.  In a few hours… new data may suggest differently… but at this time I like more of a marginal winter storm event to be affecting the state.

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Snowcast Event 8 – Update 2 – Noon, Sat, Feb 6

See very little reason to change the ongoing forecast… and none will be made.  A few little twists and turns in the model data this morning… but overall, not enough to cause a significant shift in thinking.

Forecast soundings continue to suggest snow in northern Oklahoma tomorrow afternoon as precipitation increases in response to lifting from warm air advection and approaching southwest U.S. system.  This “lead” snow doesn’t look like it will be too heavy… but a couple of inches will be possible in a few spots.

Leading edge of very cold air will move into the state early Monday and quickly advance across the entire state by sunset.  The NAM (heavier) and GFS are in slightly different camps with regard to how much precipitation will fall.  The previous forecast accounted for this and took a bit of a middle ground… and will follow suit with this.

Forecast soundings from the NAM point toward a change over to all snow in the OKC area between 9 a.m. and Noon on Monday.  This may be a bit too early… but 3 to 5 inches look possible even with a change over after Noon.

Southwest U.S. system will be onshore and sampled better by upper air analysis by this evening.  Look for tweaks or full scale changes this evening…

Snowcast Event 8 – Update 1 – 4:38 a.m., Sat, Feb 6

This special snowcast is being issued to address the potential for snowfall in parts of Oklahoma beginning earlier than previously expected… and now well within the 48 hour window.

Southern stream system will be moving onshore in southern California today.  It is forecast to continue moving eastward under the western U.S./Canada ridge of high pressure and start to increase lift over Oklahoma by late Sunday.  Meanwhile… compact but rather strong upper low over Hudson Bay at the current time will begin to shift south southwestward toward the northern Plains and upper Midwest.  It is with this that cold arctic air will start its trek southward through the Plains.  There are no appreciable differences between the GFS and NAM with respect to how this scenario unfolds… but the NAM is stronger with the southern stream system.

By Sunday evening… both models are similar in breaking out precipitation across southern Kansas and northern Oklahoma in regime of warm air advection.  Forecast soundings show a profile favorable for snow near and just south of the Kansas/Oklahoma border.  Models traditionally have issues with detecting warm air layers just above the surface that could keep this portion of the event mostly liquid… however, will buy into the solution for now and believe that an inch or so of “early event” white stuff could pay a visit to the northern tier counties.

The arctic air will begin moving into northwest Oklahoma near sunrise Monday.  Again… there are very few differences between the two main operational models here.  It should quickly surge southward across the state bringing much colder air and strong north winds.  By this time… low pressure will be intensifying south of the Red River.  There will be many mechanisms of lifting taking place and widespread precipitation will be breaking out.  It appears as if the timing of cold air and main precipitation will overlap over the northwestern half of the state which will create the potential of heavy accumulating snow.  The combination of the snow and strong winds will cause visibility in the high impact areas to drop to near zero at times.

As is usually the case… the toughest part of the forecast involves the southern boundary of snow – where it will be located and total amounts near and just north of that boundary.  There will be a period of time – especially the first half of Monday – where warm air just above the surface will be fighting against the advancing/deepening cold air favoring rain over snow.  It just so happens that once again… this will likely fall somewhere close to the OKC metro area.

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Winter Weather Returning to Oklahoma

Just an early look at the evening NAM which seems to be falling in line now with previous GFS runs suggesting that winter storm conditions may very well return to the state during the day Monday extending into the nighttime hours.

The system producing the precipitation will be moving rather quickly… so accumulating snowfall may not last more than about six hours.  However… the snow that does fall is likely to be heavy in some areas.

At this time… the greatest chance of heavy snowfall / 4-6+ inches / looks to be north of a line from Mangum to Piedmont to Jay.  Sound familiar?

Air behind this storm will be a lot colder than the last.  There will also be a lot of wind for a period that will create some very low wind chills.  Will take a look at data during the next 12 to 18 hours and introduce a snowcast at noon on Saturday…

Turning a corner?

Possibly… but some very cold air is on the horizon.  We have passed what “averages” to be the coldest part of the winter.  On this date in 1996… Okarche saw a low temperature of minus 2.  Yes, bitter cold air can still make an appearance in Oklahoma.  However… the temperature charts show good things just around the corner.  Here in a couple of weeks… we will start seeing a steady increase in average and record temperatures.  The average low temperature on February 19th exceeds 32 degrees for the first time since the first part of December.

That was the good news… the bad news is that arctic air looks like it will soon make a run at the state.  Morning data suggests that cold air will spill into northwest Oklahoma Monday morning and have a solid hold on the entire state by nightfall.  There may be a mix of winter precipitation with it – even some accumulating snows in northern Oklahoma… but the cold air/wind chills will likely be the main story.  Still need to watch this one close as we will be flirting with the potential for significant precipitation.

The cold air looks like it will remain in place or at least close enough to make the next storm system (Wednesday night/Thursday of next week) interesting.  It seems the most likely candidate of the two systems to produce snow and ice in the state.  Plenty of time to watch this one…

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Snowcast Event 7 – Update 4 – Midnight, Thu, Feb 4

Marginal snow situation for the main body of Oklahoma is unfolding with several locations in far western Oklahoma seeing light snowfall at this hour.  The Panhandle which had snow start earlier and heavier has seen some pretty good accumulations in areas with the potential for 6 or 7 inches in the western part.

Forecast soundings show a profile that will favor snow currently in western Oklahoma… spread northeast through the Enid area and then across northern Oklahoma during the day today.  Accumulations will be mostly on elevated/exposed surfaces and generally light – but a couple of places may still see upward of two inches.

Current model trends suggest that earlier forecast for northeast Oklahoma was likely a little too aggressive and have backed off that area slightly.

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Okarche, Oklahoma