It’ll be another nice day today and tomorrow. Highs in the 60s. Lows in the 40s. Very typically Winter-like for the region.
Speaking of “the region,” someone asked me the other day, “Does this forecast include me?” and I realized that a lot of folks may be new to reading my forecasts, so I wanted to repost the “forecast area” that I try to cover.
The darker the red, the more applicable the forecast. I try to cover most of southern Mississippi as well as a few counties in Alabama and parishes of Louisiana. Maybe one day I’ll expand out, but for now, I’m happy to help out the folks I’ve spent the last seven years.
So places like Jackson, Meridian, Laurel, McComb, Hattiesburg, Hammond, Slidell, Biloxi, and Mobile. Points nearby and between.
That said, as we move through Saturday and into Sunday, I may have to split the forecast up between “north” and “south” because it looks like there may be a pretty stark contrast between what may happen in Jackson versus Mobile.
Here is a look at the estimated radar from the ECMWF weather model. It shows a line of showers and storms moving from west to east across the region.
The lines I’ve drawn from top-to-bottom (yellow, orange and orange-red) are the surface dewpoint values. The yellow is around 57F. The orange is 59F. And the orange-red is 61F.
These become very important. Because to get severe weather in the region, generally you need a surface dewpoint higher than 57F. If it isn’t 57F it is highly unlikely that you see any severe weather. So, if we look at the snapshot in time above, the first thing you can “take home” is that if you live near or north of I-20, the likelihood you see severe weather, given the data available, is very very low.
Now, the higher the dewpoint value, the easier it is to get a severe storm. So, the potential for severe weather increases as you move closer to the Gulf. Sort of. Sadly, as most of you guys know, weather isn’t binary. It takes more than one thing to make weather happen.
So lets take a peek at some of the forecast soundings from the NAM computer weather model. And I’m going to compare closer to Biloxi against closer to Jackson.
Closer to Biloxi (left), there will be more instability at the lower levels, turning of wind with height, and a temperature and dewpoint that are high enough to produce storms and the potential for severe weather.
Closer to Jackson (right), there is some low-level instability, but that is elevated off the surface. That means that any thunderstorm activity won’t be based on the temperature or dewpoint on the ground (when storms are based on the ground-level conditions, we call that surface-based). Because any thunderstorm that develops will be based on what is happening with instability in the clouds only, we call that “elevated” because all the stuff that is making the storm a storm is happening above ground-level.
So there may still be storms along I-20, but they won’t be surface-based. And the best part about storms that are not surface-based is they can’t really produce tornadoes (or at least, I’ve never read about, seen or heard of such a thing). You can still get thunder, small hail, and some gusty wind. But severe weather is far less likely.
Farther south, where storms will be surface based, it looks like there may be the potential for a stronger storm or even a severe storm. The Storm Prediction Center, this morning, jumped on-board with what I’ve been saying the last few days.
They introduced a chance for storms along the coast, leaving the “better” chance for severe weather to the east.
CIPS Analogs
I know I’ve been talking about the CIPS Analogs a lot lately, and not much has changed there. But there has been a subtle shift. I haven’t shown the “new” version of the CIPS data yet, because I wanted to see if what popped up yesterday was the start of a trend or just a blip on the radar, so to speak.
So here is a look at what the new version of the CIPS Analogs are showing.
Yesterday it showed a wide area of 10-percent severe weather potential. Today, it has added a 15-percent area along the Mississippi coast.
This is a bit different than the “older” analogs which show that historically, the threat is farther north and to the east.
Still, to this point, the only “good” analog is the Jan 2016 analog. Which continues to score higher.
Today the Jan 2016 analog came back at an 11.3 out of 15. Recall it started two days ago at a 9.5. An 11.3 is about 75-percent. So not perfect, by any means. But when we start to talk about a score of 12, we start to feel a bit better.
The only problem is that aside from the Jan 2016 analog, no other analog score above an 8.6. So, it would seem, that there is only one good analog. And that day created a fair bit of severe weather.
But before you get too worried, know that no two storm systems are alike. A bit like snowflakes. So, just because something is a good analog and it produced severe weather doesn’t mean the next one will, too.
Wintry precip
This one is going to be very, very, very hit or miss. And we are going to need all of the right things to come together at the same time in the same place to make it happen for folks. So I wouldn’t count on seeing any.
Honestly here. A lot like last time, some folks will see a few ice crystal flurries, but most folks will not.
As the cold air plunges into the area, the temperatures from about 4,000ft up will be cold enough to get snow. But, we have to wait for the temperatures below 4,000ft to cool off enough. And given the wind direction behind the cold front, this may take up to 6 to 8 hours.
But for the places that cool down quicker, there may be some overlap between the cooler air that gets shoved into the area and enough lingering moisture, plus some forcing left over that we are able to squeeze out some very low-level ice crystal flurries.
This wouldn’t be “true” snow, but it would be frozen precipitation falling lightly.
Often times with these ice crystal flurries it is enough to see it floating in the air, but it doesn’t do much else. precipitation rates are so light and the flurries so small that it may not even get the pavement wet.
So any sort of freezing or travel problems are, frankly, not possible.
Could things change? Sure.
Will they change enough to warrant any kind of Wintry preps? Highly unlikely.
This is more of a novelty event than anything else.
The Bottom Line
I tend to think there will be a slice of the Gulf Coast that has the potential to see a few severe storms, and if model trends continue in the direction they are moving, I wouldn’t be surprised if the SPC expands their Risk area for severe weather.
This won’t be a significant severe weather day.
In fact, based on the data, I would say that heavy rain, frequent lightning, wind gusts up to 60mph and small hail will be the main concerns. Tornadoes can’t be ruled out, but if they do occur, they would mostly be brief and weak.
TIMELINE:
Saturday 9a – 2p: Passing clouds, breezy, with a few heavy showers and rumbles of thunder possible.
Saturday 2p – 9p: Showers and storms move through the region, some stronger storms possible to the south and closer to the Gulf Coast. A severe storms can’t be ruled out.
Saturday 9p – Sunday 2a: Clearing skies, breezy, cooler with a few lingering showers. A few ice crystal flurries may develop closer to I-20. Depending on how quick cooler temperatures push in, flurries may be able to get squeezed out as far south as HWY 98.
Day-to-Day Forecast
Today
Sunny. Highs in the mid 60s.
Tonight
Clear. Lows around 40.
Friday
Sunny. Highs in the mid 60s.
Friday Night
Partly cloudy. Lows in the mid 40s.
Saturday
Mostly cloudy with showers possible in the morning, a line of storms likely in the afternoon. Stronger storms possible. Severe weather can’t be ruled out. Breezy. Highs in the mid 60s. Southeast winds 10 to 15 mph. The chance of rain 80-percent.
Saturday Night
Mostly cloudy with a 30 percent chance of lingering drizzle or flurries. Lows in the 30s.
Sunday
Mostly cloudy in the morning then becoming partly cloudy. Cooler. Highs in the upper 40s.
Sunday Night
Partly cloudy. Lows in the lower 30s.
Martin Luther King Jr Day
Sunny. Highs in the mid 50s.
Monday Night
Mostly clear. Lows in the lower 30s.
Tuesday
Sunny. Highs around 60.
Tuesday Night
Partly cloudy. Warmer. Lows in the lower 40s.
Wednesday
Partly cloudy with a 30-percent chance of showers. Highs in the upper 60s.
