WBRC Weather

Ever Wondered What Causes The Colorful Sunsets?

(Green Pond, AL)

I’ve received lots of emails about the colorful sky that we witnessed Friday afternoon. Most viewers have described a dark red and orange colored sky over the horizon. These colorful scenes are caused by the scattering of light. This scattering of light is linked to the colorful sunrises and sunsets we witness on clear dry days. It is also the reason our sky is blue. 

So if you wondering what object is scattering the sunlight, its actually the small targets suspended in the atmosphere. The light produced by our sun produces a visible spectrum of different colors, blues, greens, and reds. Blue colors are associated with the shorter wavelengths on this visible spectrum while reds are associated with the longer wavelengths. When the suns light strikes the tiniest molecules in our atmosphere (air molecules) the short blue wavelengths are scattered more effectively, producing the blue sky we see on a daily basis. This scattering is known as Rayleigh Scattering after British Physicist Lord Rayleigh. In the late afternoon the light has to travel further through our atmosphere resulting in more scattering of light and we are left with the beautiful yellow and red colors. This is also the reason a full moon may appear red when it is low on the horizon. 

There is another type of scattering named after German physicist Gustav Mie. When light interacts with particles larger than the wavelengths in the visible spectrum the result is a white color. This scattering is associated with particles like water droplets and dust. It is also the reason clouds are white and the reason for hazy conditions on humid summer days in Alabama. Both types of scattering are not exclusive but often occur together to provide colorful scenes like the one witnessed on Friday. If you capture a colorful sunrise or sunset pic please share. There are several ways you can submit your pictures. You can email them to us at pix@wbrc.com, through our free Fox 6 Weather App, or you can share them via facebook or twitter. 

Fox6 Meteorologist Wes Wyatt
Twitter @weswyattweather
Facebook.com/weswyattfox6
wwyatt@wbrc.com

Severe weather update 153 am

...SEVERE THUNDERSTORM WATCH MISSISSIPPI...

....WIND ADVISORY FOR ALABAMA THURSDAY...

A strong cold front is located in Arkansas early this morning, and is moving southeast rather quickly.  Southerly flow ahead of the front has started to bring warm, moist air at the lower levels into Mississippi and west Alabama (see Wes's post below), and as the front gets closer, winds will increase this morning, possibly gusting to 30 mph in valleys and 40 mph or more on ridgetops. 

As is often the case with winter time systems, there is a lot of wind shear with this one.  Winds at the surface are blowing out of the SE at 20 mph or so, but at 3,000 feet, winds are blowing out of the SW at 60 mph, producing spin in the atmosphere.  Helicity values, that represent the spin in the atmosphere necessary for storm rotation, are between 200 and 400 m2/s2 in MS this morning, and these values will spread over Alabama by 6 am.  This means that storms can survive in a more stable environment than normal, and also that storms that do form may rotate.

However, the air is not that unstable for thunderstorms, and is not expected to become very unstable today in areas north of I-20.   Even with some warm air at the ground, temperatures aloft are not too cold, therefore storms do not have much energy.  However, we will have to watch closely, as there have been some reports of wind damage with the storms in Arkansas and Texas last evening, and with winds of 60 mph just above the surface, it will not take much of a downdraft in a storm to bring some of those winds down, producing scattered wind gusts of 50 mph around central Alabama and maybe some power outages.  This should not be a major storm for Birmingham, Tuscaloosa, or Anniston.  Farther south, where the air will be more unstable, a few more storms may be severe, and there is a small chance of tornadoes.   You can never rule anything out as we learned last week in the storms that came through and produced a tornado on Finley Avenue that lasted 2 minutes, but most of us will see wind and rain.

It will get much colder after the front goes by Alabama, with temperatures dropping into the 40s by this afternoon, and wind chill near 30 by 5 pm.  Friday morning will be very cold with temperatures near 30 and wind chills near 20.

More later, as we will be watching this situation carefully at WBRC.

On the northern end of this winter storm, snow is falling tonight, and thundersnow, much like we had in the Blizzard of 1993, is occurring over parts of Iowa.  Check out this video.

(madridiowaweather.com) 

Dr. Tim Coleman

Research Meteorologist

Fox 6 Severe Weather Expert and Blogger

Twitter at timbhm

 

NWS Issues A Dense Fog Advisory-Low Visibilities Expected Tonight

FROM NWS...DENSE FOG ADVISORY IN EFFECT UNTIL 9 AM CST SUNDAY...(FOR COUNTIES HIGHLIGHTED IN GRAY)

THE NATIONAL WEATHER SERVICE IN BIRMINGHAM HAS ISSUED A DENSE FOG
ADVISORY...WHICH IS IN EFFECT UNTIL 9 AM CST SUNDAY.

* TIMING...WILL LAST THROUGH 9 AM SUNDAY MORNING.

* VISIBILITIES...WILL BE LESS THAN ONE QUARTER MILE AT TIMES.

* IMPACTS...DUE TO FOG WILL CREATE HAZARDOUS TRAVEL CONDITIONS. DRIVERS
  SHOULD USE EXTRA CAUTION.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A DENSE FOG ADVISORY MEANS VISIBILITIES WILL FREQUENTLY BE
REDUCED TO ONE QUARTER MILE OR LESS. IF DRIVING...SLOW DOWN...USE
YOUR LOW BEAM HEADLIGHTS...AND LEAVE PLENTY OF DISTANCE AHEAD OF YOU.

Dust Plume Reaches Alabama-Poor Air Quality This Afternoon

We are dealing with some very hazy conditions across the area today and this is being caused a large dust plume. High winds over the nations midsection created a large dust storm over the states of Nebraska, Kansas, and Oklahoma yesterday. The dust associated with the storm has managed to migrate eastward and settle over Alabama. Most of the dust is concentrated below 5,000 ft (roughly below the 850 MB pressure level). The air quality across the area should gradually improve by the evening hours as the dust plume continues eastward. Those sensitive to poor air quality can expect these conditions to linger this afternoon.

Fox6 Meteorologist Wes Wyatt

wwyatt@wbrc.com

Twitter @weswyattweather

Facebook.com/weswyattfox6

Air Quality Alert For Today

...CODE ORANGE AIR QUALITY ALERT HAS BEEN ISSUED FOR
JEFFERSON AND SHELBY COUNTIES...

THE ALABAMA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT (ADEM) HAS ISSUED
A CODE ORANGE AIR QUALITY ALERT FOR JEFFERSON AND SHELBY COUNTIES
FOR THURSDAY...AUG 18, 2011.

UNDER CODE ORANGE CONDITIONS...GROUND LEVEL OZONE CONCENTRATIONS ARE
EXPECTED TO REACH LEVELS THAT ARE UNHEALTHY FOR SENSITIVE
GROUPS.  CHILDREN AND PEOPLE WITH ASTHMA...ARE INDIVIDUALS MOST AT
RISK UNDER THESE EXPECTED CONDITIONS.

ADEM RECOMMENDS THE FOLLOWING ACTIONS DURING AN OZONE ALERT DAY...

CONSERVE ELECTRICITY AND SET YOUR AIR CONDITIONER AT A HIGHER
TEMPERATURE.

LIMIT DRIVING AND COMBINE ERRANDS.

USE THE BUS OR CARPOOL TO WORK.

AVOID USE OF GASOLINE POWERED LAWN AND GARDEN EQUIPMENT.

REFUEL CARS AND TRUCKS AFTER 6 PM.

LIMIT ENGINE IDLING.

USE HOUSEHOLD...WORKSHOP...AND GARDEN CHEMICALS IN WAYS THAT KEEP
EVAPORATION TO A MINIMUM...OR TRY TO AVOID USING THEM WHEN POOR AIR
QUALITY IS FORECAST.

IF BREATHING BECOMES DIFFICULT...MOVE INDOORS.

Air Quality Alert For Today

...CODE ORANGE AIR QUALITY ALERT HAS BEEN ISSUED FOR JEFFERSON AND
SHELBY COUNTIES...

THE ALABAMA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT (ADEM) HAS ISSUED
A CODE ORANGE AIR QUALITY ALERT FOR JEFFERSON AND SHELBY COUNTIES
FOR WEDNESDAY...JUL 27, 2011.

UNDER CODE ORANGE CONDITIONS...GROUND LEVEL OZONE CONCENTRATIONS ARE
EXPECTED TO REACH LEVELS THAT ARE UNHEALTHY FOR SENSITIVE
GROUPS.  CHILDREN AND PEOPLE WITH ASTHMA...ARE INDIVIDUALS MOST AT
RISK UNDER THESE EXPECTED CONDITIONS.

ADEM RECOMMENDS THE FOLLOWING ACTIONS DURING AN OZONE ALERT DAY...

CONSERVE ELECTRICITY AND SET YOUR AIR CONDITIONER AT A HIGHER
TEMPERATURE.

LIMIT DRIVING AND COMBINE ERRANDS.

USE THE BUS OR CARPOOL TO WORK.

AVOID USE OF GASOLINE POWERED LAWN AND GARDEN EQUIPMENT.

REFUEL CARS AND TRUCKS AFTER 6 PM.

LIMIT ENGINE IDLING.

USE HOUSEHOLD...WORKSHOP...AND GARDEN CHEMICALS IN WAYS THAT KEEP
EVAPORATION TO A MINIMUM...OR TRY TO AVOID USING THEM WHEN POOR AIR
QUALITY IS FORECAST.

IF BREATHING BECOMES DIFFICULT...MOVE INDOORS.



Wes Wyatt

Fox 6 Meteorologist

wwyatt@wbrc.com

Dense Fog In Some Areas

 
A Dense Fog Advisory is in place for Cullman County this morning.

...DENSE FOG ADVISORY IN EFFECT UNTIL 9 AM CDT THIS MORNING...

THE NATIONAL WEATHER SERVICE IN HUNTSVILLE HAS ISSUED A DENSE FOG
ADVISORY...WHICH IS IN EFFECT UNTIL 9 AM CDT THIS MORNING.

* TIMING AND AREAS AFFECTED...WIDESPREAD AREAS OF FOG WILL AFFECT
  NORTHERN ALABAMA AND SOUTHERN MIDDLE TENNESSEE THROUGH 9 AM CDT.

* VISIBILITY...VISIBILITY WILL BE REDUCED TO ONE QUARTER MILE OR
  LESS.

* IMPACTS...RAPIDLY DECREASING VISIBILITY WILL RESULT IN HAZARDOUS
  DRIVING CONDITIONS ACROSS THE TENNESSEE VALLEY. MOTORISTS ARE URGED
  TO USE CAUTION...ESPECIALLY IN RURAL AREAS...DURING THE MORNING
  COMMUTE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A DENSE FOG ADVISORY MEANS VISIBILITIES WILL FREQUENTLY BE
REDUCED TO LESS THAN ONE QUARTER MILE. IF DRIVING...SLOW DOWN...
USE YOUR HEADLIGHTS...AND LEAVE PLENTY OF DISTANCE AHEAD OF YOU.

Air Quality Alert For Today

...CODE ORANGE AIR QUALITY ALERT HAS BEEN ISSUED FOR
JEFFERSON AND SHELBY COUNTIES...

THE ALABAMA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT (ADEM) HAS ISSUED
A CODE ORANGE AIR QUALITY ALERT FOR JEFFERSON AND SHELBY COUNTIES
FOR THURSDAY...JUN 30, 2011.

UNDER CODE ORANGE CONDITIONS...GROUND LEVEL OZONE CONCENTRATIONS ARE
EXPECTED TO REACH LEVELS THAT ARE UNHEALTHY FOR SENSITIVE
GROUPS.  CHILDREN AND PEOPLE WITH ASTHMA...ARE INDIVIDUALS MOST AT
RISK UNDER THESE EXPECTED CONDITIONS.

ADEM RECOMMENDS THE FOLLOWING ACTIONS DURING AN OZONE ALERT DAY...

CONSERVE ELECTRICITY AND SET YOUR AIR CONDITIONER AT A HIGHER
TEMPERATURE.

LIMIT DRIVING AND COMBINE ERRANDS.

USE THE BUS OR CARPOOL TO WORK.

AVOID USE OF GASOLINE POWERED LAWN AND GARDEN EQUIPMENT.

REFUEL CARS AND TRUCKS AFTER 6 PM.

LIMIT ENGINE IDLING.

USE HOUSEHOLD...WORKSHOP...AND GARDEN CHEMICALS IN WAYS THAT KEEP
EVAPORATION TO A MINIMUM...OR TRY TO AVOID USING THEM WHEN POOR AIR
QUALITY IS FORECAST.

IF BREATHING BECOMES DIFFICULT...MOVE INDOORS.

---

 

AIR QUALITY ALERT TODAY

Air Quality will be at the Code Orange level for Jefferson and Shelby Counties today. This means that the air quaility will be at an unhealthy level for sensitive groups. Ground level ozone will become an issue between the hours of 10:00 a.m. and 4:00 p.m.

The air quality product is issued by ADEM (The Alabama Department of Environmental Management). They suggest limiting driving on poor air quality days and setting your air conditioner a few degrees higher in order to conserve energy. ADEM also suggest limiting outdoor use of chemical related items used in worskhops, gardens, and cleaning.  

Wes Wyatt

F0x 6 Meteorologist

wwyatt@wbrc.com

   

PM Forecast - Rain Possible Wednesday.

It's going to be another chilly night with lows falling into the upper 20s and lower 30s.  High pressure should keep the forecast dry over the next several days.  Temperatures will rebound into the mid 50s on Tuesday.  A weak southerly flow will develop and this will do a good job of pumping more moisture into the region.  It's possible we could see some light rain as early as Wednesday morning.  Temperatures this week will generally range from lows in the lower 30s to highs in the lower 50s.  A strong system is set to impact us by late weekend.  It's still early, but it's possible we could see some rain transition into snow late Sunday into Monday.

Tonight: A few clouds. Low 30. Winds light.
Tomorrow: Scattered clouds. High 56. Winds W 3-5.

James-Paul Dice
Fox 6 Chief Meteorologist
james.dice@wbrc.com