Archive for the ‘Winter Weather’ Category

This is the rainfall forecast thru late Wednesday…..showing well over an inch south of the I-20 corridor.  I believe that the percentages are high enough for me to forecast mostly rain for the area.  I could see some regions locally seeing 2-3” totals from the heavy rain making surface low due to come out of the Gulf of Mexico.  Someone will probably see a transition to some snowfall in the north, but the main dynamics don’t look as strong on recent model runs and I feel more comfortable saying that most of the area will be too warm for snow accumulations.  There is still some time left for things to change on the model data as the system enters our upper air network, but we certainly don’t need to modify over the next two days very much. 

Expect temperatures in the 40’s during the rainfall falling into the mid 30’s during the overnight periods.  Drier weather for the end of the week…

This evening the American guidance certainly looked different, but still too warm for any kind of significant snowfall across the southeast region.  I will say that the European came in with a similar look to the last few runs of that model….and even looked a bit better in some aspects.

This is the 500mb heights with 700mb vorticity overlayed on the graphic.  This basically displays how much turning and dynamics are available in the atmosphere.  With the mid level cyclone closing off over Mississippi and moving eastward over Alabama….this usually puts us in a good setup for a significant snowfall.  The European model has been the best model in terms of the winter systems that have affected the region this season, so we will lean in this direction with our forecast.  It is still a little warm in the lower levels for a massive snowstorm, but it’s too close for comfort….especially form I-20 northward.  We will continue to watch and update the situation as things warrant.

Another strong winter storm system will plague portions of the southeast region by Tuesday with rain and possibly some snowfall.  Will it be a system like the several we have witnessed over the last few weeks across the state of Alabama?  Well, let’s get to the details.

The short, medium, and long range models are all pegging a major storm system diving out of the plains and developing a surface low down on the Gulf coast.  The problem that we are seeing this time with the setup is the low level temperatures.  We will get into that, but first the synoptic setup of the overall system. 

The 18z SREF (Short Range Ensemble Forecast) mean is a mean of many different short range model members.  This model indicates that the upper trough and dynamics will dive and setup over Central Alabama. 

This basically shows us that the best area of lift and mid level cold pool is directly overhead.  This is a good thing in terms of having the lift for precipitation and cooler temps aloft to support some dynamical cooling in the heavier precipitation.  Heavier bands of precip could be snow in some areas due to this if the low level thermos are a bit warm.  I’m going to display a few of our computer models low level thermal profiles now.

18z NAM at 925mb (2500ft)

18z GFS at 925mb (2500ft)

What we note from each of these models is that by the time the low pressure at this level of the atmosphere is over S GA…..the 0 degree Celsius or 32 degree Farenheight line is WELL to our north.  This basically indicates to me that the low levels are having a hard time cooling with no real cold air source around.  I’m very hesitant to say that anyone in Alabama will see a significant snow in this….in terms of a forecast.  I can not make that assumption based on anything I see.  Here are the surface temperatures from the 18z NAM…

That shows 40’s spiking up through portions of the state……so the low levels are very problematic.  If we had an arctic front moving through prior….I would be all over this.  However, that is not the case.  We need this upper system to close off over central portions to see a good snowfall across the area.  This would allow us to dynamically cool through the process of snow melting through the column aloft as it falls heavily.  That is close to happening on the graphic at the top of the page, but not quite.

So….I can say with confidence that most areas will see some rainfall prior to anything frozen during this event.  Rain could start as early as Monday evening and overnight as the surface low gets together to our south.  The strength of this low pressure will have a lot to do with the amount of cold air that surges in.  The weak pressure gradient to the north of the low as of now doesn’t allow for a major cold air flood.  This could occur in future runs, but all of the models are showing a thermal issue of some kind in the low levels.  That’s why I haven’t posted those.

We will continue to watch this developing situation and post more as things change….but I would say that someone will see snow falling due to the dynamical aspects.  How much and where?  No one could answer that at this point.  Stay tuned…

Tonight on the radar we are seeing some developing flurries across West Alabama with a wave that is passing through.

Not expected to be anything major, but still interesting none-the-less.  Temperatures are in the 20’s so any precip will be in the form of snowfall.

Our next wave is showing up in the NW this hour and will bring us some rainfall by early Monday.

This system will once again be minor, but models are starting to key in on a potential winter weather maker that could bring significant snows to the deep south by late Tuesday into Wednesday.  Here is our short range ensemble model as of the 21z run of the system.

Deep upper trough over portions of Alabama with a lot of spin and lift in the atmosphere.  This is a good setup for falling surface pressures and cyclogenesis.

This NOGAPS chart shows a similar scenario with parts of Alabama getting pounded.  Not much time this evening but will go more into detail tomorrow.  Have a great night.

With the Winter Storm Warning now in place….we decided that it was time to update our forecast accordingly to what we are seeing this evening.  It still looks like a good bit of snow and ice will fall across the viewing area starting late tomorrow and into early Monday.  Here is the latest updated snowfall graphic that we have come up with

Here we are suggesting the major accumulations along and north of the I-20 corridor…..with 2”+ expected north of a Pickens to Shelby to Randolph County line.  The precipitation is expected to remain all snow in northern portions of the forecast area, thus we have adjusted the higher totals accordingly.

Now to the ice.  Areas south of I-20 are in for a potential significant icing event beginning tomorrow afternoon.  Do not be fooled when snow starts to fall at the very beginning.  Trust me…it will be changing over eventually.  Areas closer to I-20 will be the last to change to sleet or freezing rain, but it will happen.  Accumulations of .25”+ can cause a great deal of problems such as tree damage, frozen roads, power outages.  Here are a few tips to think about if you are in these icing locations…

• If you live in the country and rely on well water….when the power goes so does your well.
• Prepare with an alternative heat and cooking source if you are fully electric.  Camping grills and heaters are great for this kind of event.
• Check on the elderly!  Elderly people are very prone to serious health issues and even death during extreme winter events.
• Keep cash on you instead of debit/credit cards.  If you must get out…if the power is out at most locations cards will not work.
• STAY OFF THE ROADS!  We aren’t used to this kind of weather in our area….wrecks will be numerous if you travel.

Stay tuned with us for the latest details with out ever changing forecast as new information becomes available.  Prepare now because you are almost out of time.  Stay tuned…

After looking at everything this morning….I believe that we are still in decent shape with maybe a few changes needed on snow totals and ice accumulations later on this afternoon once we get a full suite and days worth of data.  Current indications are that we may need to adjust our icing totals upward south of the I-20 corridor.  We will get into that later.

We are planning to build a large page with our team members live video cameras from different locations around the state.  If you are interested in possibly helping us out and would like for your camera possibly shown on a local news affiliate during the storm….send me a message to bamastormchaser@gmail.com and we will get you setup and ready to stream the ice and/or snow event at your location.  This will in the process help us with real time views to correlate radar data with what is actually happening.

Our next update will come later in the evening as we prepare our next call on the winter weather situation across the deep south.  Have a great Saturday!

The model above is the GFS.  One of our global models that we look heavily at when it comes to our weather.  Looks as if the model is trying to depict a scenario of some ice/snow potential for Central/North Alabama and maybe even areas to the south like Troy and Andalusia as we enter the late Sunday into Monday time period.  Keep in mind this is just one run of one model.  However, some of the past runs of other model data have depicted a similar scenario. 

This evening a few of our other models have decided to veer from a consensus and show a couple of other possibilities.  The CMC (Canadian) model is now showing a warmer picture with the surface low riding through Birmingham and pulling northeast bringing an all rain event….and maybe some thunder to southeastern counties.  The ECMWF still has the Gulf surface low on schedule and brings it eastward along the coastline.  This model is in track with our GFS model above except it is a tad warmer this run suggesting some wintery precipitation and rain mixing. 

What we can say right now is that we are rather confident that portions of the area will see a winter weather event this weekend.  This definitely has the potential to be a high impact event…..in the form of ice, snow, or both.  We won’t talk potential totals until the Friday/Saturday time frame, but we do expect for some accumulations and travel problems across portions of the area. Stay tuned to later forecasts and analysis from us as the event approaches and more details are brought to light. 

A few days before Christmas we were pegging on a potential Christmas winter storm that could plague parts of the southland with there first white Christmas ever.  This all turned to fruition during the early morning hours of the 25th and gave most of us what we had all been waiting for.  To the setup…

The night before the short range models started coming in more aggressive with precipitation.  These models started showing accumulations throughout the southeast region including north and central Alabama.  Here is a model image of the 00z BAMS model that is derived from Baron Services in Huntsville, Alabama.  Baron Services provides broadcast media with in house computer graphics for radar and weather modeling.

This model began showing the 2” criteria snowfall that is border line for a winter storm warning in this part of the country.  So, now that things began locking in on a greater snowfall potential we were watching this system develop from our homes.

The morning of Christmas Eve, December 24th, our system was developing in western Texas and to the north across the Dakotas.  We watched from our in-house system as the upper air system strengthened and moved across Texas as snowfall continued to move southward from Illinois, Iowa, Missouri, and Kentucky.

The surface low began to crank in far south Texas and precipitation was much more expansive that forecast by the short term models over portions of Texas, Oklahoma, and Arkansas.  This led many forecasters to believe that even with a more aggressive approach that the models may be coming in a bit too weak with the system.  The European, the most aggressive model of them all, was beginning to look like a good solution to place your bets on.  By the late evening hours and early morning hours on Christmas…..winter weather advisories/warnings began to fly.

It is nearly unheard of to have winter weather advisories down to Dothan, Alabama any time of the year much less Christmas.  However, this was a good call as snowfall began transitioning southward the morning of the 25th as our surface low transitioned along the coast with new upper level energy moving in to bring the colder air aloft with it.  Local radars began showing the transition zone as a “bright banding” feature.

Above is the transition zone around 10 am across portions of Jefferson, Shelby, and Talladega County Alabama on the leading edge of the precipitation.  This bright banding was due to some evaporation of the heavy precip. aloft.  It was reaching the surface in the form of sleet and snow as the column above cooled to isothermal.  In other words…..the heavy precipitation brought the colder air down with it to the surface allowing the mixture or changeover to all snow.  Basically….here was the end result for most areas.

Snowfall totals varied across many locations with Central Alabama receiving 1-2” in most cases with heavier totals of 4”+ in the Huntsville area.  Portions of Jackson County took 6” with power flickers being reported before the snow ended.  Black ice also became a problem when all was said and done as the cold air and windy conditions settled in.  Another winter weather advisory was required on 12/26 due to a large upper level low dropping in and bringing in colder air aloft allowing the low to wring out all over the moisture available in the atmosphere.

As the low moved northeast…..the BAMS models was pinpointing a potential major blizzard for the northeast.  Parts of NJ, NY, MA, etc. expected to get 2’ of snow!  Here is the BAMS model assessment of the situation from 00z 12/26.

Now…..here are the results from Vimeo user Michael Black of New Jersey.  These are images shot from a DSLR in a 5 minutes sequence during the blizzard.  Amazing 20” snowfall for these folks.

This is likely something that many of us in the south may never see again in our lifetime.  This is the first recorded white Christmas for parts of the Birmingham CWA since records have been kept.

Temperatures this evening just are not budging in parts of northeast Alabama.  The temps are still running below freezing from Heflin to Huntsville where icing is a major problem from the earlier freezing rain and sleet that we received.  Numerous motor vehicle accidents have been reported along with injuries.  Plain and simple…..if you don’t have to be out tonight stay indoors. 

We still expect this thermal boundary to move to the north eventually and bring everyone in the area above freezing….along with bringing some rain to us tomorrow.  The rain should be on the light side but temperatures will rebound into the 50’s and some places in the south will certainly get into the 60’s. 

We are now monitoring the potential for some winter mischief on Friday night as another compact  mid level wave comes across the region when temperatures will be conducive for frozen precipitation.  We don’t expect a major event AT THIS TIME.  I will say…..expect the unexpected when it comes to mother nature…..or plan for it at least.  We will bring you more up to date information following tomorrow mornings data.  We should have a better handle on the situation by then.

Alot of issues are ongoing and have already occurred with icing across the area from Troy on to the north.  The Freezing Rain Advisory has been allowed to expire west of I-65, but it’s still in effect until 3PM east of 65.  A total of 3 deaths have been reported thus far with many serious injuries.  Parts of I-59 have been closed as well.  Here is a look at surface temperatures and what to expect for the rest of the afternoon.

Icing potential should end for all areas including the far northeast counties by 5PM.  Warmer air is moving in from the SW and Jackson, MS is hovering near 60°!!  We should warm up even into the overnight hours and reach a temp near 60° tomorrow in Central Alabama.

Here is some video of the sleet/freezing rain from Childersburg.  YouTube didn’t convert very well, but you can see the traffic continuing with the icing ongoing as well as the ice bouncing off of vehicles and accumulating on stepping stones. 

Stay safe during the rest of your Wednesday afternoon.  Conditions will improve this evening.