Archive for February 2nd, 2013
Skies have cleared quickly over the northern half of the area, and the clearing is progressing southward as our disturbance pulls away.
Areas that saw measurable rain today will be especially susceptible.
Be alert to the presence of the fog if you will be driving this evening or later tonight.
It should burn off quickly tomorrow morning, setting the stage for a mostly sunny day with just a few clouds developing. Highs will be in the lower 50s after lows near or just below freezing tonight.
The National Weather Service has issued a Dense Fog Advisory until 3 AM for all of Central Alabama. A dense fog advisory means that visibilities will frequently be reduced to one quarter of a mile or less. The showers that have moved through Alabama and subsequent cooling associated with them are making conditions favorable for the development of fog across the state this evening and into the overnight hours.
Dense fog has developed in many areas across Alabama and it will last for several hours. Expect the fog field to expand through the overnight hours, but should begin to mix out by about sunrise. Visibilities will be less than half a mile. Travel could become hazardous in some areas that have dense fog. Please slow down and use your low beams.
As we head throughout the rest of the evening and into tonight we will see the rain diminishing and the skies clearing. If the clouds get out of here in time, temperatures may be a few degrees cooler than expected. Already seeing clear skies in in our northwestern counties. Expect some of our northern counties to settle into the upper 20s. Birmingham metro will be right around the freezing mark. The majority of the rain activity has finally shifted south of I-20, with the heaviest rain falling along Highway 280 around Alexander City over to Wedowee.
Additionally, we are seeing some fog developing this evening in areas that received rain from the showers that are continuing to push off to the southeast and into Georgia. The fog could become dense at times, but no advisories have been issued. Just use the low beams if you encounter any if you are out and about tonight. Tomorrow’s weather will be much better than today, expect a cold start but skies will be sunny and temperatures will rise into the mid 50s by mid-afternoon. There will be a brisk north wind as well, so it may feel a little cooler than it actually is.
Many areas across North Alabama continue to pick up some cold winter rain. May still have a few sleet pellets or even a snow flake mixing in over some areas. The precip is not falling as heavy as it appears it is on radar. This commonly happens in the winter time. High returns show up because the precip in the upper levels is all frozen and reflects the radar beam better, and if there is a thin liquid layer covering the ice pellets, it will even have higher reflectivity and that is what we are seeing today. With the lower few thousand feet of the atmosphere above freezing, most of the winter precip is melting before reaching the surface. We are seeing the best radar returns across the Tennessee River Valley and even down into Winston, Walker and Fayette Counties.
The rain continues to be along and north of Interstate 20 this afternoon. Movement continues to be more east than south. Most areas south of I-20 should remain relatively dry for the rest of today. Most of the rain is over Alabama, with the back edge near Tupelo, Mississippi. This will last for a few more hours as it will continue to move off into North Georgia. Surface temperatures are above the freezing mark so we are seeing no issue with icing on roads. Just look for some slick spots as roads will be wet. Temperatures will stay above freezing overnight and the rain will be out of here before we start our Sunday.
Early this afternoon we have a mix bag of weather across Alabama. Looking at the latest satellite image, the northern half of Alabama has mostly cloudy to overcast skies. The southern half of Alabama, is basking in the sun. These clouds across the north should continue to move east throughout the afternoon, and should still be around into the overnight hours. The clouds should actually help keep most of our temperatures above the freezing mark tonight. Underneath some of the thicker clouds we are seeing some very light showers.
A peek at the radar shows some of these showers. Nothing heavy, and most of the activity remains north of the Interstate 20 corridor. This activity will continue to slowly move to the east, still could see a mix of sleet and snow in some of our northeastern counties, but nothing too significant. The clouds and showers should be out of here by tomorrow.
The NWS in Huntsville has trimmed back the winter weather advisory. It remains in effect until 2 pm for just Dekalb and Jackson counties.
Temperatures across all of the Tennessee River Valley have risen above freezing. The atmosphere appears to have warmed enough that all of the precipitation has switched over to snow with the exception of the two northeastern counties of Alabama where a mixture of sleet and freezing rain is still possible.
The NWS in Atlanta has also issued a winter weather advisory for the northwest corner of Georgia for this afternoon until 7 pm.
Here is a picture of some precipitation falling from clouds over Trussville a short while ago. Some of that is virga, or precipitation that is evaporating before reaching the ground. But some of it is reaching the ground in the form of sprinkles. Automatic sensing windshield wipers are sweeping glass in some areas as those sprinkles fall, but there probably won’t be many observations of measurable rainfall.
You can see the precipitation associated with an upper level disturbance. That disturbance is triggering a mix of precipitation including light snow to the north and light rain and sprinkles to the south.
Across North Alabama, temperatures are in the 30s, and there were some bridge icing issues over North Alabama. A winter weather advisory has been in effect for North Alabama.
The NWS Huntsville recently trimmed that advisory to just Jackson and DeKalb Counties. Problems continue in higher elevation locations of Northeast Alabama, like around Mentone. Here is a report from the NWS Huntsville: Geraldine [Dekalb Co, AL] emergency mngr reports SNOW of E0.0 INCH at 10:52 AM CST — a dusting of snow/sleet has melted and refreezed on area roadways…particularly on highways 75 and 117 in the Geraldine and Mentone areas creating icy conditions.
There could still be a little sleet mixed in with the rain over the northeastern counties in places like Gadsden and Fort Payne and Scottsboro through early afternoon.
Over Central Alabama, readings are in the 40s.
After some sunshine this morning, skies are clouding up thanks to the disturbance. But even as some experience sprinkles, there are peeks of sunshine.
Highs this afternoon will top out in the lower 50s in the I-20 corridor, with 40s further to the north.
On Friday, February 1, 1985, the forecasts were dire for the Birmingham area and much of Central Alabama. It was expected to be the biggest winter storm since the 1982 ice storm. Winter storm warnings were issued for the area north of a line from Livingston to Birmingham to Anniston.
Weather reports called it a dangerous storm with two inches of freezing rain and snow mixed expected. Here is an except of a statement from the National Weather Service:
A DAMAGING ICE STORM IS AHEAD FOR NORTHWEST ALABAMA. THE NATIONAL WEATHER SERVICE EMPHASIZES THIS WILL BE AN ICE STORM OF DAMAGING PROPORTIONS. THERE WILL BE POTENTIAL MAJOR DAMAGE TO TREES AND UTILITY LINES AND NUMEROUS HIGHWAYS WILL BECOME IMPASSABLE. THERE WILL LIKELY BE NUMEROUS AND EXTENDED POWER OUTAGES. EARLY THIS MORNING…POWER LINES WERE ALREADY FALLING IN SOUTHERN LAWRENCE COUNTY AND ON MONTE SANO MOUNTAIN IN HUNTSVILLE.
Trees were expected to lose limbs and power lines were going to fall. Advice was to bundle up, stock up on flashlights, batteries and candles. Stay indoors and get to know your family better.
Low pressure was predicted to push east northeastward along the Gulf Coast, in a situation familiar to thousands of Alabama snow fans, as cold high pressure to the northeast stubbornly blocked its progress. The warm, moist air would be lifted over the dome of high pressure, leading to overrunning precipitation that would fall as a wintry mix.
The icy mix did materialize early in the day over Northwest Alabama and as rain fouled the morning rush hour in Birmingham, forecasters warned that temperatures would fall during the day, turning the rain to freezing rain and sleet and eventually some snow. An icy coating began to form on trees as far south as northern Jefferson County.
By late morning, up to six inches of sleet and freezing rain had fallen over Northwest Alabama over parts of Lauderdale, Colbert, Franklin and Marion Counties, paralyzing the area. Schools and roads were closed.
By afternoon, businesses were closing and people were going home early in Birmingham, remembering the bad situation during the January 1982 ice storm which trapped thousands on area highways. The expectation was that sleet and freezing rain would begin before dark.
The storm did pull its punch for much of Central Alabama, but Freezing rain did accumulate on trees and power lines in the Birmingham area, putting hundreds of thousands of people in the dark. The winter storm warning was dropped early Saturday morning. Older people will remember the alert that replaced the winter storm warning: the traveler’s advisory.
But up to eleven inches of sleet and freezing rain covered parts of Northwest Alabama. Roofs collapsed on three businesses in the Florence area and numerous carports and awnings fell victim to the weight of the sleet and snow. For the first time in recorded history, roads were closed in the Florence area. Most Huntsville television stations were off the air. People were stranded on I-65 north of Cullman for a time Friday evening. It was the worst winter storm since 1963 in Northwest Alabama.
US-78 northwest of Birmingham was a skating rink with numerous accidents being reported. An ambulance carrying wreck victims to Carraway Hospital overturned, injuring the crew.
Four people died as a result of the winter storm in Alabama.
Quick post of a Skycam shot captured around 9:05 am showing the bridge issues in North Alabama. Numerous reports of sleet and freezing rain and you can see on the bridge in the left center of the picture some whiteness which appears to be sleet. At the Skycam site, the precipitation had ended for the moment, but radar continued to show patches of light frozen precipitation moving across North Mississippi and North Alabama. A winter weather advisory for all of the Tennessee River Valley counties remains in effect until 2 pm.
If your plans call for travel northward from Central Alabama, delay them or allow extra time for the trip.
The morning soundings are in and they certainly tell a great story. Here is the Birmingham sounding taken at the Shelby County Airport in Calera.
As you can see, the temperature line (red) and the dew point line (green) are a respectable distance apart indicating that the air is fairly dry – not bone dry, but probably enough to evaporate most of any precipitation that might fall. Also, the sounding from about 800 millibars down is above freezing.
The Nashville sounding, on the other hand, is moist especially above 800 millibars, and the temperature aloft is below freezing except for a very small layer just above 900 millibars.
The big question, of course, is exactly where the atmosphere transitions. Based on surface reports, much of the radar echoes showing up on radars along and just north of the Tennessee River are sleet and freezing rain. The echoes just south of the Tennessee River are probably also sleet and freezing rain, but the atmosphere may be a little too dry for now for that precipitation to reach the ground. This may change through the mid morning hours as additional precipitation falls into the dryer air causing the humidity of that layer to rise.
In response to this information, the NWS Huntsville office has extended the winter weather advisory further east as well as extending the time for icing conditions until 2 pm as shown by the purple area in the map below.