Winter Storm Octavia

Hey Everyone,

Im back here on my blog format for tonight to lay out everything in a much better format versus Facebook. First off, I wanna say thank you everyone for all the positive feedback I have gotten. I have managed to get almost 20,000 page views on my Facebook Page in the last 4 days.

Getting on with the Nuts and Bolts of this impending Winter Storm.

It looks very likely that most of South Carolina will experience Winter Weather.

When: Monday Evening through Wednesday Mid Day.

Where: Will cover that below but areas North and West of I-95 should pay close attention.

What will Fall? A little bit of everything. Rain, Freezing Rain, Sleet, and Snow.

Impacts : Hard to say for now but there could be significant impacts such as dangerous slick roads, extended power outages, falling trees, And ice on everything imaginable.

Setup:

During the day tomorrow an area of Low Pressure is expected to begin to develop over Eastern Texas and Louisiana this area of Low Pressure is then expected to move ENE over the Deep South and by Monday afternoon will make its approach on South Carolina. 

I am not expecting anything significant until after 7PM Monday for any portion of South Carolina and Western North Carolina. It appears that moisture will move into the area before then but, due to low dew points and some really dry air in place, it will take a few hours to get the atmosphere wet enough to support precipitation falling to the ground. 

There has been some uncertainties in regards to the exact track of the Low Pressure. This is going to be pretty important. A jog 75 miles each way could mean a Winter Wonderland or just a soggy, raw day. I am hoping that the models come into better agreement over the next 18-24Hrs so I can have a better idea of what to expect. 

Miller A or Miller B ?

Below this paragraph is the 18z GFS Model Run from today and it has hinted at this storm phasing and becoming whats called a Miller Type B Storm. There is also a Miller Type A Storm which has one centered area of Low Pressure that usually remains offshore. Im sure you all are asking yourselves What is a Miller Type B Storm ? Miller Type B storms usually involve the following during Cyclogenisis. (An area of Low Pressure Forming and Strengthening)

• 2 Low Pressures Involved (One Primary Low, and a Secondary Low)
• The Secondary Low develops along the coast as the Primary Low over Land weakens.
• Usually occurs in situations where CAD is in place. (Cold Air Damming or "The Wedge)
• The Secondary Low can become quite intense, quickly. 

Again this only a model run and not a Forecast. 

What to Expect over the duration of the event:

This will likely start out as all snow on Monday evening after 7PM and as Isentropic Lift increases we will see a "nose" of warm air overrun the cold air at the surface. This will result in a change over to Sleet and/or Freezing Rain on Tuesday morning. During the day on Tuesday as temps warm I would expect a changeover to all rain for a few hours before once again, turning back over to freezing rain. This will remain the same until early Wednesday as the system strengthens off the Coast. If this happens, we would see cold air wrap around the Low Pressure and have yet another changeover to all snow. With the Cyclogenisis of the storm there could be a band of heavy snow that sets up somewhere in North and South Carolina.


Other Models: 

All of the other models are in agreement in Winter Precipitation but there a few differences in position, timing, and Precip Type. 

Locations:

For now, I have listed below the official National Weather Service's map of Freezing Rain accumulating greater than .01" see your area with the corresponding percentages.

Until models come into better agreement I am not going to throw any specifics out there. We will save that for tomorrow. 

 

Accumulations:

Given the model uncertainty as of now I cant say for sure who is going to get what and how much of it. Areas that do get the winter precipitation could get upwards of .10" of Ice and 1" of Snow.

In Closing:

I wouldn't be surprised at all for the National Weather Service to issue a Winter Weather Advisory or Winter Storm watch by 7PM tomorrow given the current information. I will be watching this like a hawk tomorrow and will do another write up tomorrow evening. Hope everyone has a great evening and be sure to check back tomorrow!


- Chris

8PM Weather Update. 1/11/2015

Hey Everyone,

I have been looking over all of the weather data for the last couple days trying to get a grasp on this possible Freezing Rain event on Wednesday Morning. Note that I said Freezing Rain. Snow isn't on the table for Wednesday Morning, sorry but, just telling it like it is. I also decided to make a post on my blog here so I can better convey my message and add graphics into my post. I will also say that there is an outside chance at some snow on Thursday as Low Pressure will move Northeast off the Coast. Anyways, lets get into it.

This is the official National Weather Service Freezing Rain Probability Forecast. Notice the distance from 0-70% is less than 75 miles.  This is the probability of at least .01" of Freezing Rain. 

Tuesday Night and early Wednesday morning, an area of high pressure in the Northeastern part of the Country will give us the "wedge", a layer of cold air at the surface.

The million dollar question is a two part question,

A.) How far south will the cold air make it by the time the moisture arrives ?
B.) How much moisture will we have ?

Here are my thoughts,

Timing and Temperature

Wednesday morning I think there will be areas of freezing drizzle and maybe light rain. However, I do not foresee this being anything significant in South Carolina. However folks in North Carolina, may be in for a little more ice. Areas from Winston Salem over to Raleigh and down to Fayetteville could see more significant ice that could cause issues.

By Wednesday morning in the Columbia area temps will be flirting with 32 Degrees and predicting where it will be freezing and where it wont is next to impossible. It all depends on how far south the cold air makes it and that is yet to be seen. Below is the latest GFS model run and note how at 7am Wednesday morning they have Columbia at 33 degrees and surrounding areas at 32 degrees. Its going to be that close and I wont know until as soon as maybe 12-18hrs in advance. So Stay Tuned on that.

7AM Wednesday Morning Surface Temps. This is a model not a forecast. Note the "U" Shape feature in Southwestern Georgia into Eastern Alabama. Thats how far South the "Wedge" will come down the eastern Appalachians. 

How Much Precipitation

This storm system will not provide an abundance of rain during the time frame that we will be near the freezing mark. This is why I am not foreseeing anything significant for Wednesday morning. An area of Low Pressure will develop and move off our Coast by later in the day.

My Prediction

I think late Tuesday night and into early Wednesday morning there will be a large area of light freezing precipitation in the area and then will change over to rain during the day on Wednesday sometime in the late morning hours till around lunch time.

As of now I do not see any need to go out and do the bread and milk grocery store scramble.

All in all, whatever we get I do not see this being a significant winter weather event in the Midlands of South Carolina.

For Reference I have listed 2 more photos below with captions.

This is the Sperry-Piltz Ice Accumulation Index. This is a good ball park idea of what type of impacts you can expect given the accumulation amounts of Freezing Rain and with accompanying Winds. 

This is a great example of how different percipitation forms. This is a visual representation of what ive been saying for the last few days. 

In Closing,

I will be doing a forecast every day this week due to the impending storms and updates as needed. There is also a chance of "something" Thursday evening but, I am not even ready to talk about that. Hope everyone has a great evening and thank you all again for all the support.

Chris

Current Weather and Looking Ahead

Hey Everyone,

Wanted to post about the current weather conditions and touch base on the rest of the week. I know some of you may be wondering where all of this cold air is? Well, it is coming I promise. With the warm air this morning it has taken a little longer to get down here to us but, it is surely on the way. If you go 90 miles up the road to Charlotte right now its currently 38 Degrees and here in Lexington it is still in the lower to mid 60's.

I expect the cold air to get into the Columbia/Lexington area within the next 2 hours and temperatures will start falling like a rock once it gets here.

As for Sleet/Ice, I just honestly don't think were going to get anything here. The moisture is just not going to be there in order for us to see any big winter weather. Thank God. With that being said, I wouldn't rule out some sleet pellets or maybe even a snowflake later on tonight but, dont stare at the windows looking for it.

I know I said the other day that an Ice Storm may have been in the works for Thursday but, that just simply hasn't panned out. It looks like as of now, just a cold nasty rain.

With that being said here is what I am thinking for the rest of the week...

Through Tonight - Temps falling like a rock after around 3-4PM and we will end up around 26-28 Degrees by daybreak Also expect wind chills tonight to get down to 15-20 Degrees so be mindful if you're going outside.

Winter will be with us for the rest of the week with Temps staying well below average and expect off and on showers Wednesday - Friday with the most rain coming Thursday.

Weekend is looking good as of now with Temps getting back to the mid and upper 60's



As Always,

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Looking Ahead

Hello Everyone,

Last week I had posted a system I was watching for the potential to bring another blast of winter weather to South Carolina around March 2nd. Over the course of a few days after I made that post, things just didn't materialize and I feel extremely confident in saying that on March 2nd we will not see any snow or winter weather for that matter. Looking ahead, I have picked up on a little trend for March 6th, showing the possibility of a system developing in the Gulf of Mexico and moving across Florida and eventually off our Coast.

With that being said, just like last time I am not saying we will see a winter storm at this time. However the possibilities are there so I just want to keep everyone informed. Right now, I would give this a 10% chance of happening.

I also want to put a disclaimer out here..... If you see someone posting snowfall total maps for a system 7-10 days away please IGNORE THEM. Thats a joke, you simply cannot predict snowfall totals that far in advance.... I hate seeing those wishcasting forecasts on Facebook, Twitter, etc, etc.

Lets get into the Setup.

This is March 5th showing a piece of Energy (Circled) over Oklahoma and Northern Texas. This is the remnants of a Low Pressure System from the Pacific Northwest. It will be pushed our direction by High Pressure centered up in the Dakotas. 

Fast Forward 12 Hours on Match 5th and you can see this piece of Energy now in the Deep South and an area of Low Pressure starting to form off the coast of Jacksonville Florida.

By March 6th, you can see the area of Low Pressure and model data suggests CAD (Cold Air Damming) on the Eastern Slopes of the Mountains. CAD is highlighted in Yellow.

Model data on March 6th also suggest the entire state below freezing at the surface. 

March 6th, 850MB Temps are below 0C. This is not at the surface! The 850MB level of the atmosphere is in the lower Troposphere where snow forms. In order to get snow, temps must be below 0C. 

All of the above data comes from the Canadian Model. It has been really good this winter on its model data forecasts. If your wondering about the GFS and Euro. See Below.

• GFS - Also hinting at a Winter Storm however, keeping more of the colder air in North Carolina. It suggests March 4th-6th as the timing.
• Euro - Not suggesting anything of any significance. However, the deterministic snowfall models have been trending up for the March 4-6th time frame. 

In Summary, 

This is a long ways out but, something I am watching. It is entirely possible that we could get one last snowfall before spring and on the flipside, it is entirely possible that this could bust out and it could be 70 degrees on March 6th. It will just have to be watched over the next 5 days and see what happens with this. 

Like my goal is as always, I'm giving you guys the honest, sensible, and credible possibilities with the weather. I may not be first but, I wont be wrong! 

Thanks again for the continued support and spread the word! Without readers like you, none of this would be possible. 

Till Next Time, 

Chris Jackson

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