Archive for January 1st, 2017

Dense Fog Advisory Posted for North Central Alabama

| January 1, 2017 @ 7:46 pm

The NWS has issued a dense fog advisory for North Central Alabama, in effect until 9 a.m. CST Monday.

Visibilities may drop to 1/4 mile or less overnight. Be very careful if you will be out driving.

0.66 inches of rain at the Birmingham Airport as of 7:01 p.m. Additoinal rain will fall in the Birmingham Metro over the next couple of hours. I-59 will sort of be the northern extent of the rainfall over the next couple of hours.

Happy New Year! January’s Infographic Is Hot Off The Press

| January 1, 2017 @ 7:08 pm

Welcome to a new year, and to what usually ranks as the coldest month on the calendar for the city of Birmingham. The average high for the entire month of January is 52.8 degrees, while the average low is 32.3 degrees. The month starts off on New Year’s Day with the average high at 53 degrees, and the average low at 33 degrees. By the time you reach the 31st, the average high has only risen to 55 degrees, while the average low dropped during the month and has made it back up to 33 degrees.

January represents the depths of winter in Central Alabama. The days are growing longer now as we have passed the Winter solstice, but you can hardly tell it in the month’s temperatures. The coldest low temperature ever recorded for the city of Birmingham happened on January 21st, 1985, when the mercury dropped to -6 degrees. 1940 is ranked number 1 as the coldest average low temperature for the entire month, at 21.5 degrees.

Surprisingly, it can get very warm in January as well. Back on January 10th, 1949, the thermometer topped out at an amazing 81 degrees. 1950 is ranked number 1 as the warmest average high temperature for the entire month, at 66.6 degrees.

January is ranked as the second wettest month for the Magic City, with March being the only month averaging more rainfall. That is some very encouraging news considering that the city of Birmingham is still classified in an exceptional drought by the U.S. Drought Monitor. On average, Birmingham generally receives 5.45 inches of rain throughout the month, and rain usually falls in the city on 11 days of the month. The wettest month on record for Birmingham was recorded in 1937, when an astounding 13.37 inches of rain fell throughout January. The driest January on record was in 1981, when only 1.09 inches fell.

Snowfall in the city of Birmingham is rare compared to most of the other major cities throughout the United States. Since 1930 (a total of 86 years), measurable snow has fallen in January in the Magic City a grand total of 24 times. During that span, Birmingham has only averaged 0.70 inches of snow in January for each year. The highest recorded snowfall in a 24-hour period during the month of January was 9.5 inches back in 1940, while the most January snowfall fell back in 1936 at 11.80 inches.

January can also be called the gloomiest month of the year, even though most see the month as “a new beginning” over the previous year. January ranks number 1 as the cloudiest month, with the skies being cloudy 48% of the time. It is also considered the foggiest month, with dense fog reported on average of 1.3 days.

Finally, 2016 ended for the city of Birmingham with the city in an exceptional drought. The Magic City tallied 40.31 inches of rain for the year. The yearly average for the city is 53.72 inches, which means Birmingham ended the year with a deficit of 13.41 inches. Maybe 2017 will grace us with the needed rainfall to return us back to normal totals, and keep any destructive severe weather away from Birmingham.

A Quick Look at the Wintry Threat for the End of the Week

| January 1, 2017 @ 3:48 pm

I have a feeling the European has a good handle on the situation for the end of the week.

It is a classic situation for a winter storm in Alabama, with a developing wave moving eastward along the Gulf Coast and a cold air mass invading Alabama from the north. But in this situation, we don’t have a strong enough surface low or a cold enough airmass to produce a big event.

The European’s solution is very plausible to me. It goes like this:

By after midnight Thursday night/Friday morning, rain will be falling across Louisiana and Southwest Mississippi. Some snow will break out over northern Mississippi. It will be very light.

It will move into Northwest and North Central Alabama around or before sunrise. It will be a rain/snow mix further south and snow further north.

The best chance of a little light snow will be over Northwest Alabama between sunrise and 10 a.m. Friday.

The precipitation is mostly rain by afternoon, over all but extreme Northeast Alabama where it could still be snow.

A rain/snow mix may show up over South Alabama after midnight Friday night.

There are the European’s snow totals:

You would see a dusting across parts of Marion and Winston Counties into the Tennessee Valley. With some light dustings over South Alabama on the back side.

This is by no means a forecast, but rather one plausible scenario that beat represents what I think could happen Friday. It would be a low to no impact event winter event for Alabama.

We will have frequent updates on the wintry weather trheat for later in the week and the severe weather threat for tomorrow.

Severe Weather Threat to Kick Off the New Year

| January 1, 2017 @ 2:00 pm

A significant severe weather threat is on the table for Monday afternoon and Monday evening across Central Alabama. The greatest threat for a couple of tornadoes will be south of US-82 from Tuscaloosa to Montgomery and points south, but all of Alabama has a risk for severe weather.

SETTING THE STAGE: By late tonight, a southerly flow will begin to increase across the area in response to big high pressure to the east and developing low pressure to the west. By noon, that surface low will be over eastern Texas. Another round of showers and thunderstorms will break out by noon across Central Alabama as the warm front lifts north. Some of those storms could be strong, but shouldn’t get out of hand.

Significant tornado parameter from the 4km NAM model for Monday evening at 6 p.m. Values over 1 are indicative of an environment capable of producing EF2 or greater tornadoes.

STRONGEST STORMS BY AFTERNOON: The best chance will come from mid-afternoon on as the surface low lifts northeast into Mississippi. Instability should ramp up with CAPE values increasing to between 600-1,200 joules/kg, which is certainly sufficient for strong thunderstorm updrafts. There will be good speed shear with winds increasing to 40-50 mph at 5000 feet out of the southwest. This will allow storms to be organized and supercell storms will not be out of the question. Directional shear should be strong, with southeasterly winds at the surface, veering to southwesterly through the lower levels of the atmosphere. This means a potential tornado threat.

THREAT AREA: Once again, there is considerable confusion in National Weather Service products, with the Strom Prediction Center putting nearly all of Alabama in their Slight Risk, or standard severe weather category, meaning scattered severe storms possible, and areas south of US-82 in their enhanced category, meaning numerous severe storms possible. I think the SPC risk area is justified based on the instability and shear profiles we see for late tomorrow afternoon and evening.

TORNADO THREAT: I think the SPC is correct in their thinking that a strong tornado or two is not out of the question in the enhanced risk area south of US-82 late tomorrow afternoon and evening. The peak threat time may come between 6-9 p.m.

TIMING: General thunderstorms from noon to 3 p.m. along the warm front, with more intense thunderstorms developing by 2-3 p.m., and continuing through the late evening hours until midnight.

Lots to Talk About

| January 1, 2017 @ 12:58 pm

Happy New Year! Lots to talk about on this first day of 2017. I will do a quick summary and then will come back with some more specifics about the severe weather threat, Sugar Bowl weather and the wintry threat for late in the week.

DREARY SUNDAY
A nice mass of rain is moving northeastward across the I-20/59 Corridor early this afternoon. No thunder is involved. There is just no instability. Rainfall amounts from this batch should run 0.20-0.40, with a few lucky folks getting 0.50 inches. Clouds are thick and temperatures are in the upper 50s and lower 60s.

ANOTHER ROUND THIS EVENING
Another batch of showers, this time with the possibility of some thunder, will overspread much of the area tonight. Another quarter of an inch is possible.

SEVERE WEATHER MONDAY
A northward lifting warm front will set the stage for thunderstorms Monday afternoon and evening. There is a risk of severe weather for all of Alabama, with an enhanced risk for the area south of US-82 from Tuscaloosa to Montgomery. Damaging winds and a few tornadoes are possible and a couple of strong tornadoes are not out of the question. The main threat will be 2 p.m until midnight tomorrow.

COLDER END OF THE WEEK
Things will begin to turn colder by Tuesday night with highs in the 40s Wednesday and probably 30s Thursday and Friday. A system moving along the Gulf Coast may spread rain over the southern half of the state Friday and Friday night with some light snow possible over the northern part of Central Alabama. Lots of uncertainty here and penty of time to refine the forecast. Let’s get through the severe weather threat first.

SUGAR BOWL
Tens of thousands of Auburn fans are in New Orleans for tomorrow night’s Sugar Bowl. Flash flood watches are in effect and lots of rain and thunderstorms are in the forecast through late tomorrow afternoon. Things should start to clear before fans make the trek to the Superdome howere, which is great news. There is an enhanced severe weather threat there tomorrow afternoon, but it should be well out of the way before time to head to the game.

Wet and Stormy Weather for Start of 2017

| January 1, 2017 @ 7:22 am

Clouds covered much of the Southeast US this morning along with a good deal of fog. Dense fog advisories were confined primarily to the Lower Mississippi River Valley across Arkansas and Louisiana. But for the first day of 2017, it was mild as temperatures overnight actually climbed under the influence of warm air advection and southerly flow. Readings across Alabama ranged from 66 at Mobile to 45 at Fort Payne. Most of the rain this morning was confined to Southeast Alabama but additional rain is expected to develop later this morning and this afternoon as the moisture out of the Pacific continues to pump into the Southeast US. Highs today should climb into the lower and middle 60s.

If you plan to head to New Orleans to see Auburn play against the Oklahoma Sooners in the Sugar Bowl with a 7:30 pm kickoff tomorrow night inside the Super Dome, thunderstorms will threaten the area through the day, so rain gear will be a good idea for going to and from the game. It will be warm in New Orleans with a low in the upper 60s and the afternoon high around 80.

Heading to the beach? It will be cloudy with multiple chances of rain today and into the start of upcoming week. Partly sunny days and fair nights are forecast later in the week. It will be mild for the next several days with highs in the lower 70s, but turning colder Wednesday with highs in the middle 60s. See the complete Gulf Coast 7 Day Planner here.

The closed low/trough over the Northwest Mexico this morning will eject northeastward on Monday bringing the threat of additional rain and the potential for severe weather to a large portion of Alabama. SPC has placed all of Alabama in a slight risk of severe storms with an enhanced risk covering nearly the southwestern third of the state including cities like Tuscaloosa, Livingston, Selma, Greenville, and Mobile. GFS develops a surface low over northern Louisiana around noon on Monday and moves it northeastward across Memphis by 6 pm and into the Ohio River Valley by 6 am Tuesday. CAPE values are projected to be in 1000 to 2000 j/kg range Monday afternoon gradually diminishing into the evening hours. Helicity values by 6 pm Monday are forecast to be in the 300 to 400 range, so besides the threat of damaging wind, it appears likely that there could be a tornado threat too. Mondays highs may reach the lower 70s with dew points in the lower 60s, so this three should definitely be taken seriously.

Since we’re coming off the holidays, today would be a good time to review your severe weather safety plans and be sure you have a good way – best to have more than one way – to get weather warnings. The greatest threat for severe storms appears to be between 11 am and 11 pm on Monday.

The upper short wave moves to the Mid-Atlantic States on Tuesday as the rain will end from the west across Alabama. It looks likely that we’ll remain cloudy through the day on Tuesday as the rain ends, but we might see a few breaks in the clouds by late afternoon. Based on the current frontal passage timing, temperatures Tuesday are probably going to be holding steady or falling during the day with daytime values in the lower 60s.

We gradually go under the influence of a broad developing trough on Wednesday and Thursday. This will put us under cold air advection for several days with temperatures gradually getting lower. Highs Wednesday will be in the upper 40s falling into the upper 30s on Thursday.

The models have done another flip flop for Friday. Yesterday the ECMWF was dry while the GFS showed some rain with a band of potential wintery precipitation. This run has flipped just the opposite with the GFS dry and the ECMWF showing a narrow band of light snow for Friday afternoon. There is little to no confidence in the forecast for the end of the week as long as the models keeping flipping. For now, my forecast is going to remain with the GFS for a rather cold but dry day on Friday. Any precipitation that does develop is likely to be light with the impact of any winter weather low. The GFS moves the surface high onto the Atlantic Coast on Saturday bringing a return of moisture back into the Lower Mississippi River Valley. This brings the possibility of rain into the forecast for next weekend, but the threat of any wintery precipitation with this pattern should be minimal as we warm up quickly under developing southerly flow.

Yesterday the GFS was pretty calm on the upper air patterns in voodoo country. This mornings 06Z GFS run is anything but calm! The upper air pattern now develops a fairly strong trough just to our west around the 10th and digs it into the East Coast by the 12th suggesting another round of pretty cold weather. But the upper flow goes into a strong ridge over the East with a closed low over Northwest Mexico by the 14th, a pattern very similar to the one we’re dealing with right now. So this would point to the potential for another multi-day rain event as the flow taps into Pacific moisture once again. Ain’t this fun?

Thanks for sticking with the Weather Xtreme Videos while James has had a bit of down time. He should be back with the next edition of the Weather Xtreme Video Monday morning. I’ll be subbing for Meaghan Thomas on ABC 3340 New at 5 and 10 pm today, so be sure to tune in for the latest on our wet and stormy situation. Have a great day and Godspeed.

-Brian-

Severe Weather Threat Tomorrow

| January 1, 2017 @ 6:16 am

After another cool, wet day, a strong southerly flow develops across Alabama tomorrow, bringing warmth, unstable air, and the threat of severe storms. SPC has now upgraded the threat; there is an “enhanced” severe weather threat for much of West and Southwest Alabama… including Tuscaloosa, Brent, Greensboro, Demopolis, Selma, Camden, and other communities down to the Gulf Coast. The standard “slight risk” of severe storms covers most of the rest of the state…

METEOROLOGICAL SETUP: Dewpoints will surge into the 60s, with temperatures rising into the low 70s tomorrow, making for an unstable atmosphere; surface based CAPE values will rise to well over 1,000 j/kg by mid to late afternoon. An approaching wave aloft will bring support for storms, along with a surface low moving out of Texas, which will bring surface winds around to the southeast. There will also be considerable strengthening of lower/mid wind fields, including southerly 40-50 knot flow around 850 mb (5,000 feet), veering to west/southwesterly at 50-70 knots around 700 mb (10,000 feet). This should provide more than sufficient low-level and deep layer shear for organized severe convection, including supercells.

TIMING: Strong to severe storms are possible across Alabama in the 2:00 p.m. to 12:00 midnight time frame. Some of the highest STP (Significant Tornado Parameter) values from the NAM model come tomorrow night…

But, again, severe storms will be possible during the afternoon as well.

THREATS: Thunderstorms across Alabama tomorrow afternoon and tomorrow night will be capable of producing damaging straight line winds, hail, and a few tornadoes. According to the Storm Prediction Center, “A strong tornado or two may not be out of the question.”

CALL TO ACTION: Tomorrow is a holiday for most, meaning many families will be traveling and not in their usual place on a Monday. So, be sure you have a way of hearing severe weather watches and warnings. At home, you need a properly programmed NOAA Weather Radio with a battery backup. On your phone, for warnings we recommend WeatherRadio by WDT. You can watch our live severe weather coverage on the free ABC 33/40 app. Here are the links…

ABC 33/40 iOS version for iPhones and iPads

ABC 33/40 Android version for Android phones and tablets

Review your action plan in case a tornado warning polygon includes your home. Get in a small room, on the lowest floor, away from windows, and near the center of the house. You do NOT have to be underground. Never be in a car or mobile home.

WINTER MISCHIEF LATER IN THE WEEK: We have to get through the severe weather threat tomorrow before we can really have any confidence about the forecast late in the week, but there is still some chance of light wintry precipitation showing up across North Alabama Friday night or Saturday morning. For now it seems like a low end, low impact issue, but again we won’t have any confidence in this forecast until mid-week.

Keep an eye on the blog for updates!