Archive for January 8th, 2017

Hurry! Go Check Your Barometer!

| January 8, 2017 @ 12:23 pm

After a cold Saturday and Saturday night that never saw the mercury go above freezing for much of the area, the ol’ thermometer is making slow but steady progress today.

At the surface, the big blob of high pressure (top left panel) extends from a center over western Kentucky down into Mississippi, Louisiana and Alabama. At the center of the high, the barometer is well over 1040 mb, because right now, barometers adjusted to sea level are reading over 30.75 inches or 1041 mb.

You won’t see your home barometer that high around these parts very often.

Aloft, a huge trough is along the East Coast. Northwesterly winds on the back side of that trough are bringing some high clouds into the state, that are dulling the sun and slowing the melting process.

Roads that were ice covered or slushy overnight are slowly improving, but still slick in spots. Shady areas will be the worst. Heard reports of major problems still on Clairmont on Birmingham’s Southside and Overtone Road to the east.

A wreck on I-65 SB just south of Lakeshore has the southbound lanes backed up for over a mile. You may want to avoid that area. That accident may have been ice related.

280 East out of Downtown is still very slow and US-31 coming up or down the hill by Brookwood Hospital is still a mess. US-78 is problematic from Avondale to Oporto.

I-20/59 to Tuscaloosa is in great shape according to reports, but I-20/59 through downtown is a mess.

459 appears to be in good shape except southbound in the big curve near Liberty Park.

Roads are open but please use EXTREME caution. And just stay home if you can.

Where Did the Cold Come From?

| January 8, 2017 @ 11:27 am

Ever wonder where the air in your location actually came from? Well, using the NOAA’s (National Oceanic and Atmospheric Administration) HYSPLIT model, you can do just that.

The HYSPLIT model is a complete system for computing simple air parcel trajectories as well as complex transport, dispersion, chemical transformation, and deposition simulations. HYSPLIT continues to be one of the most extensively used atmospheric transport and dispersion models in the atmospheric sciences community. A common application is a back trajectory analysis to determine the origin of air masses and establish source-receptor relationships. HYSPLIT has also been used in a variety of simulations describing the atmospheric transport, dispersion, and deposition of pollutants and hazardous materials. Some examples of the applications include tracking and forecasting the release of radioactive material, wildfire smoke, windblown dust, pollutants from various stationary and mobile emission sources, allergens and volcanic ash.

So I ran the HYSPLIT model this morning using Birmingham, AL, as the end point, asking the program to track back the trajectory of the air in place here. Using the latest GFS model data, it provided me with this map showing that our air, our cold air, began seven and a half days ago over the northern Pacific.

So the air that brought frigid conditions to Central Alabama this morning actually began in the North Pacific southwest of the Aleutian Islands around 500 feet and following a path that brought it southward across a large portion of western Canada until its arrival here. Our atmosphere is absolutely amazing!!


Roads Still Icy in Spots; Many Churches Canceling or Delaying Services

| January 8, 2017 @ 7:55 am

Saturday was still a mess across the Birmingham metro area as well as almost all of I-20 east of the city.

The sun tried very hard to fix things, working in conjunction with plenty of dry air was sublimation. But shade and temperatures that never reached freezing conspired against the process.

Problems continued through the overnight hours and into the early morning, with most of the problems affecting I-65 south of Downtown, the Red Mountain Expressway and I-20.

Here is a look at Google Map with traffic as of 7:53 a.m. Of course, areas in orange and red probably have icy spots that are slowing people.

Many churches have wisely canceled their services or delayed them.

Things will slowly get better this morning with a good supply of sunshine. But temperatures will climb only slowly through the teens and twenties this morning, reaching freezing by noon.

And highs will only top out in the middle 30s, so there will still be problems in spots.

Be careful if you must drive.

Frigid Start to Your Sunday

| January 8, 2017 @ 7:04 am

It is starting out very cold this morning with some of the coldest temperatures we’ve seen since early 2015! As I’m writing this the temperatures across North and Central Alabama ranged from 10 at Fort Payne to 18 at Calera (Shelby County Airport). And our Skywatcher at Black Creek has reported a low of 7 degrees! Looks like we could go above the freezing point this afternoon with lots of sunshine coming in from a clear sky. Highs today are expected to reach into the middle and upper 30s.

As you probably expect, the cold has a grip on much of the Nation so there are no areas of severe weather projected for the next few days.

The surface high will migrate eastward into the Atlantic Monday and Tuesday. This will turn the surface flow around to the south in the Lower Mississippi River Valley on Monday and here late Monday and Tuesday. Daytime highs should climb to near 50 on Monday and into the 60s on Tuesday. Don’t you just love the rapid turn around we experience in the Southeast US? 14 degrees on Sunday morning and 60 by Tuesday afternoon!!

The upper air pattern shifts from a deep trough along the East Coast today to ridging Monday and Tuesday. But by Tuesday we’re watching a trough move quickly through the fast moving flow to our north resulting in a cold front that will be dragged into the Southeast US late Tuesday and Wednesday. Front loses it’s forward momentum as it becomes parallel to the upper air flow. This will provide us with the best chances for rain from late Tuesday into the first half of Wednesday. But those chances, while the best, are not expected to be particularly high with rain probability standing around 40 percent. Rainfall amounts will be lower than what was projected yesterday with places getting rain only receiving about a quarter of an inch at best.

The upper air pattern is forecast to remain a ridge from an upper high centered over the Florida Peninsula for the latter half of the week ahead. Another front will drag southeastward Friday but it is not expected to actually reach the Southeast US as we were seeing yesterday. This run of the GFS is much more bullish on the upper ridge with the primary action to our west where a deep trough and closed low are forecast to dig into northwestern Mexico. This pattern is reminiscent of the one we saw the first couple of days of 2017 as that trough taps into Pacific moisture. The primary threat for a rainy pattern appears to be a little to our west over Texas, Arkansas, and Oklahoma for the 15th of January. That rain will finally come our way around the 17th as the deep trough ejects east-northeast across Texas. But this is verging several days into voodoo country, so you can expect to see changes to the forecast before we actually get to week 2.

As I mentioned yesterday, the pattern is expected to remain fairly fast. Once the trough ejects by us around the 18th, we’ll have a couple of mild days with another trough digging into Texas on the 21st of January. That one will move by us around the 22nd and turn the upper flow northwesterly again with another potential for some cold weather as we get to 372 hours into the forecast.

WORLD CLASS TENNIS RETURNS TO BIRMINGHAM: The BJCC will host the first-round tie against Switzerland February 3rd-5th. Single-day tickets are on sale now. Get them while they last! Buy tickets here.

James Spann returns with the warmer weather tomorrow morning. I hope that you have a great day. Godspeed.