Rainy period takes hold

Current radar imagery shows the low over the state of Alabama. We are on the moist side of the front and will be there for the next couple of days. Here's the latest radar loop:

As the loop shows above (TIME SENSITIVE! (10:45 AM EDT)); there is another batch of rain heading our way. Also, another piece of energy is providing rain for southern Georgia, east of Interstate 75. This band of rain will continue to lift north and MAY scrape our eastern counties of Talbot, Taylor, Schley and Sumter. The bulk of the rain effecting our area will be coming from the south and west.

There's a nice conveyor belt of moisture moving in from the Gulf of Mexico, as illustrated by all the rain on radar. This shows up nicely in this morning's Peachtree City, GA sounding:

The precipitable water, or PW, is 1.74, while Birmingham has a PW of 1.92 so there's PLENTY of moisture to work with! The only thing stopping all this water in the atmosphere from raining out is a significant lifting mechanism. The NWS from Peachtree City, GA (FFC) indicated from their morning discussion that a lot of the rain this morning was from isentropic upglide, or air moving toward a region of the same density. For example; warm air, less dense, riding over cold air, more dense, to be with the other pockets of warm air creating light to moderate precipitation. This will be the case for another couple of hours until we get the sun to help destabilize the air. Speaking of the sun, it's peeking out to our west so we'll destabilize some this afternoon:

That's why I'm calling for a few isolated thunderstorms, below severe levels, later on today.

Taking a quick look at the rest of the week shows the moisture sticking around until at LEAST Friday morning! That's allowed me to forecast off and on rain showers for the duration of the workweek. Originally, I was forecasting between 0.50" to 1.00" for our area. That seems a tad high right now so I've backed it down to 0.25" to 0.75" for the immediate viewing area as there's been a trend to be drier than forecast, locally. Those reading elsewhere in the southeast; I anticipate most of us will managing to eek out at least 0.50" though, higher elevations could see 1.00"+.

Oh! Here's the 00Z GFS showing the cut-off low I mentioned last week:

This thing is going to SIT here for a few days before finally being kicked to the northeast. This will result in a slightly warmer weekend than originally thought but still below average with highs in the low 80s.

Thank you!

David Reese

A look back at the CAD that didn't really develop

I had advertised a Cold Air Damming setting up across portions of the southeast. That didn't really happen. Yes, we did see some cool and cloudy mornings, but we saw partly to mostly cloudy skies in the afternoon allowing us to get into the middle 80s Friday and Saturday. Here's the current situation from space this morning: 

There's a pretty good layer of cloud cover over most of Georgia, extending into east central Alabama. This has been the view the past few mornings, but the clouds haven't been thick enough to hold up with the heating of the day. You may ask yourself, what heating? There's a ton of clouds, there's no heating! Au contraire fellow reader. The atmosphere extends miles into the sky. Here's a view of the soundings to illustrate the points I'm about to make: 

Peachtree City, GA 12Z Sounding from this morning:

The green, dew point, and red, temperature, lines are very close together near the surface. That's the cloud deck we are seeing across much of Georgia! Now, here's the 00Z Sounding from last night (technically today but I'll say last night since it was from 8PM Sept. 17, 2011 ;))

There's the same inversion, where the red line starts going back to the right as you go up, near the same pressure level, but notice the temperature line near the surface is WAY right of the dew point line. This is why we didn't see much cloud cover yesterday afternoon. The atmosphere mixed itself out bringing slightly drier air from aloft. Another reason the NWS pointed out was the absence of confluence, where air flows inward toward an axis parallel to the general direction of flow. We've had zonal flow, west to east winds, aloft, meaning the atmosphere had a chance to mix itself out and dissipate the clouds. 

That's a look back at the weekend, but what about the upcoming work week? Well, Monday appears mostly dry with the better rain chances to our west. The rain will likely move in sometime Tuesday and be off and on through Friday. Here's the model output in a nice graph for you: 

The NAM, which only goes through Wednesday afternoon, or 84 hours, has the rain moving in early Tuesday morning. I feel it brings it in a TAD early and will forecast better rain chances by early afternoon Tuesday. As we look at the GFS, it gives us almost 1.5 through Friday night/Saturday morning. This appears plausible, the good rain chances that is, with a cut-off low developing over the Ohio River Valley. A cut-off low just means it's not in the jetstream anymore and got left behind. Here's a picture of what I'm talking about: 

The low just sits over the state of Illinois for a day or so before being nudged to the northeast by the end of the week. It should be noted that a quick glance at the 06Z GFS has the cut-off low a little further to the northeast. Overall, I don't think we'll get as much rain as the GFS is putting out, but somewhere between 0.5" to 1.0". Of course, there could be locally heavier amounts in thunderstorms, but that's just a generalization for the area. 

It will be interesting to see all of this develop the next few days. As always, I'll keep you updated with my latest thoughts!

Thank you,

David Reese

Cold Front on our Doorstep and SNOW in Wisconsin!

The cold front is finally here! Current analysis shows the front moving through Birmingham:

We can tell where a front is by the wind shift. The winds in southeast Alabama and much of Georgia are from the southwest, while those across northwest Alabama are from the northwest. That's how we can locate a cold front on surface analysis! The colder temperatures are still across northern Mississippi, but they will get here later tonight. If we see the front slow up just a little, we'll see a broken line of showers move through our area. However, latest model guidance indicates we'll be on the wrong side of the front, the northern side, once it finally taps into some warm and moist air. I'm still leaving in the possibility of a few scattered showers this afternoon, but the confidence in any one spot seeing rain is pretty low. If you do see rain; don't expect much. Current QPF, liquid precipitation, output has us only getting about two tenths of an inch the next few days.

After the front passes to our south, an area of high pressure will build into the northeast. I detailed this in a blog post a few days ago. With the high over the northeast, a CAD, or wedge, will set up where there will be some VERY chilly temperatures for this time of year in the Carolinas and northeast Georgia. There's going to be a big contrast of temperatures between North and South Georgia. Northern Georgia will see a ton of clouds while south Georgia will see a good deal of sunshine. I'll be sure to post a picture of where the CAD sets up and the clouds and station plots to go with it.

From Summer to Winter!
Portions of the upper Mid-West are in the ice box this morning! Look at the current temperatures:

International Falls dropped to 20 and Embarrass dropped to 19! There was also another rare event yesterday in the Mid-West, well for mid-September anyway: SNOW! Here's the local climatology report from Rhinelander, WI:

 

This is the earliest EVER Rhinelander has seen a trace of snow! Just another hint that winter is right around the corner ;) 

Thank you,

David

The Final Countdown!

Summer is on its last legs, but it it holding strong for one final day. The area of high pressure providing us with the spectacular, albeit warm, weather the past 5 days will finally be nudged out to sea by a cold front. Yes, our second cold front of the season, remember Tropical Storm Lee's attached cold front ;), will arrive tomorrow afternoon. Our in house RPM has a bit of moisture making its way into east central Alabama tomorrow morning. I'm not totally buying that solution, but it's certainly possible. One thing I know for sure; there will be more clouds tomorrow than there will be today! We'll see a few fair weather cumulus clouds this afternoon, but not enough to keep us from reaching the lower 90s again...

Now, we usually talk about showers or thunderstorms in advance of cold fronts, but this one isn't going to have much moisture to work with thanks to the high pressure currently in place. Here's the latest QPF output by the North American models (it should be noted that the scale isn't the same as yesterday's version I showed...):

  

The 00Z GFS yesterday was putting out over .30" of rain locally... The 00Z GFS today has only .13 inches! With each model run, we've gotten drier and drier. That's not good news for the prolonged drought our area is currently experiencing. 

After the front passes, some MUCH cooler air will settle over us. Take a look at what some of the models are putting out this morning: 

Our highs go from the lower 90s today, as forecast, to the upper 70s by the weekend! Also notice, we don't rocket back into the upper 80s next week. This is fantastic news for those weary of the heat and humidity we had to go through this summer. The CAD I talked about yesterday is still being picked up by the models, which is why we are expecting cooler temperatures this weekend. I will tell you that our forecast still hinges on how strong of a CAD signature we see. If the CAD is stronger, we could see highs only in the upper 60s to low 70s; if it's not that strong, we will see highs in the mid to upper 70s, which is what I'm going with at this time.

Tropics:
I want to give you a quick update on the tropics: Tropical Storm Maria is still churning in the Atlantic Ocean, but the forecast track takes it well away from the United States. In fact, Bermuda will be brushed by Maria's tropical storm force winds, but that's the only land area that will be affected.

Looking into the extended period, the 00Z GFS has a storm forming in the western Caribbean Sea:

The subtropical ridge in the Atlantic is then forecast to break down in response to a long-wave trough moving through the Eastern United States. This trough will then drag the tropical system into the Gulf of Mexico and aim it at Florida:

This is a LONG way away in model land and should be taken with a grain of salt. It's just something I'll keep an eye on and will keep you up to date on the model's latest thinking.

Have a great Wednesday!

David Reese

Warmth won't last much longer

Good Tuesday morning everyone! It's starting to feel a little like summer again.... Highs yesterday topped out at 91 in Columbus, while Auburn had a high of 86. You can expect more of the same today, as high pressure continues to dominate our weather pattern.

By Thursday afternoon, a front will have nudged far enough south to give us a chance of rain late in the day. It will take its time moving through, so I'll leave a chance of rain in all day Friday and the beginning half of Saturday. The rain won't be terribly widespread or heavy though; as illustrated by this plot of precip from numerous computer models:

In fact, the GFS is the only model spitting out any rain locally, with the 06Z coming in drier than the 00Z run. I do have to say that the NAM doesn't forecast far enough out to capture a potential rain event as it brings the front in a tad later than the GFS. The only thing this front is assured of doing is bringing in MUCH cooler air! Highs are forecast to be in the upper 70s to low 80s by the weekend... Can you say fall is here!?

The cooler air will be aided in what we call Cold Air Damming (CAD). The high pressure moving in behind our frontal system will move from the Great Lakes to the Northeast, which will put it in prime position to develop CAD. Here's the model representation of it:

Notice how the isobars, lines of constant pressure, kink around the Appalachians? That's CAD!

You see, winds around high pressure flow clock-wise, meaning if you're south of it, you will see easterly winds. These easterly winds around a high situated in the northeast runs into the Appalachian Mountains and isn't allowed to flow up and over. This means the cold air gets dammed up and must go somewhere! That somewhere is usually to the southwest along the spine of the mountain chain and into northern Georgia. If the high is strong enough, it can filter that cold air all the way into our area! We aren't forecasting it be to QUITE that strong, but it is certainly possible. Another result of CAD is a thick stratus deck, low level clouds. You'll certainly be able to see that along the Appalachians this weekend and I'll be sure to grab a satellite image for you! Clouds help keep temperatures down during the day and if the high is strong enough, we could see temperatures even cooler than what I'm forecasting right now... Either way, we are going to see temperatures below average for the duration of your weekend.

Tuesday: A few high clouds but otherwise mostly sunny. Highs near 92.
Tuesday Night: Mostly clear with lows dipping into the mid 60s.
Wednesday: Partly cloudy with highs near 93.
Wednesday Night: More clouds move in, in advance of the front. Lows in the mid to upper 60s.
Thursday: A slight chance of rain later in the day. Otherwise, we'll be partly to mostly cloudy with highs near 90.
Friday: The cooler weather filters in! First, we have to deal with some rain, but as noted earlier; the rain won't be all that widespread nor heavy. Highs in the low to mid 80s.
Saturday: Mostly cloudy with highs near 81. (Subject to change cooler....)
Sunday: Partly to mostly cloudy with highs near 80. (Subject to change cooler....)
Monday: The high pressure in the northeast moves east, out of CAD positioning. This will clear our skies but temperatures will still be near 80.

Looking in the extended range, I notice the GFS (and the Euro to a certain extent) bringing a longwave trough into the eastern half of the country next Wednesday/Thursday. I'll watch the models closely to see if they continue this trend, which could bring some cooler air (and maybe rain!) our way next Thursday and Friday.

Thank you,

David Reese

Near Record Lows this AM

We bottomed out at 59 degrees this morning, one degree shy of our old record of 58. The cool mornings will last for the next two days before we see an influx of moisture Sunday afternoon. The weather the next few days will be FANTASTIC! Plenty of sun, pleasant temperatures and low humidity. Does it get any better than this in the beginning of September?

Our weather pattern will start shifting Sunday night, as the upper level low spinning over the Ohio River Valley forms into a trough and ejects out of the US. When the trough does form, it will bring enough instability to create a stray shower or two further to our south, near south Georgia/north Florida, where the better moisture is situated.

The 90s will return by Tuesday and linger thru at least Thursday. In the extended period of next Friday and Saturday, it appears the GFS is bringing a front through the Deep South which would bring our highs back into the middle 80s. It would certainly be refreshing, but I want to see a little more consistency before I fully jump on.

The tropics are still active.
Tropical storm Nate is located in the Bay of Campeche with a northwesterly motion of 3 mph. The trough, mentioned above, WILL miss Nate as forecast, thus making Nate to go into Central Mexico Sunday afternoon. I'm still thinking Nate gets to a category 2 before making landfall, but it still has the CHANCE of a Cat. 3. Again, Nate will NOT effect the United States.

Maria is still hanging on to Tropical storm status as of 11AM. It is forecasted to go through the northern Lesser Antilles, as forecast a few days ago, as a tropical storm. It will then pass over Puerto Rico, where they DON'T need to the rain! In fact, they've seen almost 30 inches of rain for July and August ALONE!!! Maria will then track east of the Bahamas, as the trough mentioned a few times already in this post, will kick Maria out to sea!

Thank you,

David Reese

Sunshine!!!

The sun is out in full force this morning! The clouds didn't clear out of here as early as I forecasted yesterday afternoon, off by 3 hours which isn't bad ;), but they cleared out just in time for sunrise. With the clouds gone, we're already warmer than we've been the past 2 days!

Here are the station plots and satellite image to illustrate what I'm talking about:

A little shortwave, providing rain across the panhandles of Texas and Oklahoma yesterday, has shunted our clouds to the east. These new clouds aren't nearly as dense as the past two days, so the sun will be able to filter through. The station plots also illustrate something else: warmer temperatures! We're already at 71 in Columbus at 11 AM. My forecast of upper 70s appears to have been too low and have adjusted upward into the lower 80s. Either way, we are still below average by a good 5 to 8 degrees; and I'm not hearing much complaining.

The forecast for the next two days are as simple as it gets: sun, sun, a cloud or two, and more sun!

Tonight:  With the clear conditions, we'll be a tad cooler than last night. However, with the upper level low retrograding west, we won't get as cool as they were across West Alabama and Mississippi last night (low 50s). However, some of the traditionally cooler spots could very well be in the low 50s.

Friday: A mostly sunny afternoon, with a few clouds passing through. Highs will manage to get into the mid 80s.

Friday Night: Another night in the lower 60s with plenty of clear sky.

Football Saturday! Fantastic football weather! Mostly sunny conditions with highs in the middle 80s.

Tropics: 

    Maria: Continues to book it to the west at 20 to 25 mph. Right now it is forecast to be near the northern Lesser Antilles by late Friday night/Saturday morning. It is then forecast to turn north into towards Puerto Rico. This is the likely solution right now, but I will tell you; if it stays a weak tropical storm, it will make it further west across the Caribbean Sea and will need to be watched carefully! I don't think it will attain hurricane status anytime soon and a track further to the west than the NHC's forecast is likely.

     Nate: Meandering around the southern Bay of Campeche. This is a TINY storm. It's forecast track by the National Hurricane Center has it essentially stalled for the next 5 day! This makes perfect sense since there isn't a strong steering current one way or the other to steer it toward Mexico or the northern Gulf of Mexico.The conditions are incredible for Nate to rapidly strengthen by Saturday and we could be talking about a Major Hurricane in the Gulf by Sunday. It appeared we were getting SOME consensus from the global models of Nate heading towards Mexico. However, the 6Z GFS and CMC threw a monkey wrench into that:

 

The general idea for Nate is a drift off to the north over the next few days. The BIG question will be whether it gets picked by a trough progged to move through Monday or if it gets left behind. If it gets picked up it will head toward the northern Gulf; if it gets left behind, it will stall again and meander to the west towards Mexico.

I am sticking with my forecast from yesterday of a landfall in northern Mexico as a Cat 2 or 3 Hurricane until I see better model consistency.

Thanks for reading!

David Reese

Clouds hung tough!

Good afternoon!

It looks like the clouds enjoyed the Deep South so much that they decided to stay for the afternoon. Here's the current satellite view:

There has been some clearing to our west, allowing for temperatures to get into the 70s:

Columbus has only managed a measly 68 degrees for a high! If this high holds up, it will be the record for the COLDEST High Temperature ever recorded for September 7! Crazy to think just last week we were seeing upper 90s huh.

Tonight's Forecast: You'll hear many say, "These overnight lows are all dependent on the cloud cover throughout the night." That is true! I'm forecasting the clouds to hang around another couple hours before finally dissipating some. By about 3 AM, most of our area should be seeing clearing skies meaning temperatures will easily drop into the 50s. Columbus may see the overnight low only drop into the upper 50s, while the traditionally cooler areas will see lows in the middle 50s. Keep in mind our record low temperature for tomorrow is 58 degrees, so it could be close like it was this AM.

Tomorrow: The remnants of Lee, the cause of the cloud cover the past few days, should begin its migration north. This will drag the clouds with it, but we still can't take out ALL the cloud cover. There will be enough low-level moisture to allow for a few clouds tomorrow afternoon, much like we saw this afternoon with the clouds building to the south during the afternoon. With a few peeks of sunshine, we'll manage to make it anywhere from 76 to 79 degrees tomorrow afternoon. I HAVE to say this... If we see more clouds, like today, our highs will STRUGGLE to get to the mid 70s again... Only reason I'm saying this is because I've been burned by it the past two days and my lesson is learned!

Friday: Clouds shouldn't be an issue for Friday's forecast as the upper level low continues to spin over Illinois and Indiana. That means we'll stay in a northwesterly wind flow, keeping us relatively cool compared to the average. The clouds should situate themselves across the borders of Alabama, Georgia and Tennessee, leaving us with pleasant skies and highs in the low to mid 80s (82-85).

Weekend: No major changes in store as the northwesterly flow keeps us pretty dry for the weekend. By Sunday, the ridge to our west will begin building in allowing temperatures to warm into the upper 80s by Monday. Don't be surprised to see a few low 90s in the forecast for next week as the upper air pattern flattens into a zonal flow (west to east flow aloft).

Tropics: Today saw TWO tropical storms develop in the Atlantic Basin.
         Maria: Formed with the 11AM EDT advisory and is trucking it to the west at 23 mph. The center of circulation is getting a little exposed as the low level winds are much stronger than upper level winds are weaker. This will be a problem for Maria for the next 48 hours. As it gets closer to the Lesser Antilles, it will shake this shear and possibly strengthen. Until then, Maria will stay a tropical storm for the foreseeable future and impact the northern Lesser Antilles by Saturday.

         Nate: JUST formed as of 5PM EDT and is moving to the ESE at 2 mph. The forecast track of Nate leave it in the Bay of Campeche for a while before it starts feeling the weakness in the ridge and migrates north. This trend won't last all that long as the trough causing the weakness lifts out, allowing a ridge to build to its north. If this occurs, we'll see Nate take a westerly track into northern Mexico. That's what I see happening as of now, but there are other scenarios: 1. Nate feels the weakness in the ridge a bit more than forecast and lifts into the northern Gulf of Mexico. 2. Nate meanders in the Gulf and gets some dry air to wrap into the core, thus weakening it (not likely to happen but still). Now, for intensity the forecast will be tricky. It has a TON of warm water to work with, low shear, weak steering currents and it being in an area where it could really go BOOM. Right now it has winds of 45 mph. The forecast intensity takes it up to a hurricane within the next 4 days. I'd have to agree with this though we could see Nate ramp up to a Cat 2 or 3 hurricane before it makes landfall... We'll keep a close on it over the next few days.

I'll leave you with a current look at Nate:

 Thanks for reading!

David Reese

Cooler weather and clouds hang around

Good Wednesday morning everyone! We saw temperatures dip into the upper 50s in some spots. Columbus dipped down to 59, one degree shy of tying our old record low of 58! Things should warm up a tad more than yesterday as the cloud deck isn't as thick. You may be asking how I know the clouds aren't as dense... Well, let me show you! Here's a sounding from Peachtree City, GA from 8 AM this morning:

Notice the red line, temperature profile, and the green line, dew point profile, are very close together near the surface. When these two lines are close together, there are likely clouds throughout that layer. To show you proof of the clouds I'm talking about; here's the visible satellite image from this morning:

The clouds are starting to dissipate just a bit and with the heating of the day we'll see them clear out of the sky! This will allow temperatures to creep into the mid 70s rather than the mid 60s we saw yesterday afternoon.

Tropics: 
We have a few tropical disturbances we're keeping an eye on. The first is Hurricane Katia which is forecast to pass between Bermuda and the United States. The affects Katia will have for the US are strong rip current, high surf (surf's up dude!) and minor coastal flooding.

The second tropical entity we are keeping an eye on is Tropical Depression #14.

It's looking pretty decent on satellite this morning and I anticipate it to become our next tropical storm of the season, Tropical Storm Maria. The upper atmosphere is conducive for development over the next 24 to 48 hours, but beyond that it will have to deal with some wind shear. We'll have to watch out for Maria and its potential impacts for the Leeward Islands and Puerto Rico.

Another area of convection is firing up in the Bay of Campeche. It has been designated Invest 96L:

It's firing up along an old frontal boundary; in fact, this is part of the energy left behind by Lee earlier this week! We'll have to watch this one closely as the Euro and CMC bring this towards the Louisiana coastline, while the GFS takes it into Mexico. Here's the "spaghetti" plots of the models: 

Here's my thinking on Invest 96L: As long as the dry air to the north of Invest 96L, dry air from the Texas drought, manages to stay to the north and doesn't get mixed into 96L then we'll see our next depression of the season later tonight or tomorrow morning. The ultimate location of the low level center(LLC) WILL BE IMPERATIVE! If it develops a little further to the north, more in the southern Gulf than the Bay of Campeche, it will track to the north and influence the northern Gulf Coast. If it develops in the heart of the Bay of Campeche, it will not get picked up by the trough progged to move through later this week. Right now, I'm thinking it will drift north initially and get left behind by the incoming trough and meander west into northern Mexico. This forecast is fairly low confidence as we don't have a LLC yet, just putting different scenarios out there!

Thanks!

David Reese

How I forecast every morning

I was posed the question: Do broadcast meteorologists do any calculations? The answer to this particular question 98% of the time, for me, is: No, I do not do any calculations. Most of the calculations I would potentially do are already done for me by computer programs so I take advantage of that. Yes, I will admit, if I want it 100% accurate and done correctly, I should do them every morning. I just don't have time in my everyday activities to sit there and do them.

The next question, "What exactly do you do to forecast?" That my friend, is a little more involved.

Before the advent of computers, meteorologists, on-air or off-air, got data streamed into them, over phone lines if I'm not mistaken, from the National Weather Service. They printed this data off on LONG sheets of paper, you know the good ole printer paper with the perforated edges. They then PLOTTED all of the points by hand like so:

 The meteorologists analyzed the data (maybe not as nice or as colorful but you get the idea):

 and put together their forecast. It was immensely time consuming and took about 4 hours to complete every day.

That was the old days. Fast-forward 40 years and you have a brand new world of forecasting. No longer do many meteorologists print out data sheets and plot them individually. No longer do we have to wait for data to  become available to us. The advent of the internet cured this. Granted, I should note that there ARE some meteorologists who still do plot weather maps by hand from radiosonde data.

Now that we got some of the background of old-school meteorologists, let's get back to the original topic: What I do every morning.

I walk into the station at around 3 AM and log into my computer. I then go over to our weather computers and bring up this map:

This is a water vapor map, I usually view it in motion, showing where the dry/moist air is in the mid to upper levels of the atmosphere. The reds indicate dry air and the whites, purples, blues and greens indicated more moisture, in that order. It tell me if there is a chance for mid-upper level clouds, frontal systems, areas of high pressure, shortwaves embedded within a long-wave trough which could lead to rain (or drier air) for particular areas downstream among other things. Water Vapor Imagery is a great tool to have that is garnered by geostationary satellites high above the earth.

The next piece of data I look at:

The visible satellite! This was taken over the Deep South on September 6, 2011 at 1806Z (or 2:06 PM EDT). Visible satellites, also in space ;), capture the light being reflected off cloud tops. Clouds can wreck HAVOC on a meteorologist's forecast if he doesn't predict their motion or rate of dissipation correctly. For instance, this morning when I forecasted, I didn't properly forecast the cloud cover. As a result, my forecast high temperature busted by about 8/9 degrees. Not the greatest forecast, I know, but you learn from it and move on.

The next few pieces of data I look at are the latest soundings, or temperature and dew point profiles (vertically from one point) of the atmosphere at certain locations around the US:

The first sounding is from Peachtree City, GA and the second is from Birmingham, AL. The red line is the temperature and the green line is dew point. A LOT of calculations can be done from just one of these soundings; e.g. CAPE, Lifted Index (LI), Convective Temperature, CIN, Level of Free Convection (LFC), Lifted Condensation Level (LCL), Precipitable Water (PW), Equilibrium Level (EL), etc...We don't have to calculate these every day because we have computers and programs to speed the process along. I did a TON of these calculations, by hand, in school. All those computations are important for severe weather days (CAPE, CIN, LFC, EL, LI, PW) , forecasting clouds (LCL),  forecasting rain (PW), chance of thunderstorms... That's all calculated from just the temperature and dew point lines! Look on the right hand side of the diagrams, the official name is Skew-T diagrams), Notice the wind bards changing direction as you get higher in the sky and different notches or flags. This is important in telling if cold or warm air is moving in.

Now look at these next plots:

These are station plots from around the Deep South. Notice the same wind barbs found on the Skew-T diagrams are also found here. The wind barbs depicted here are surface winds and can also tell me if colder or warmer air is on its way. The first one is from September 5, 2011 at 2PM, while the second is from September 6, 2011. Notice how the top one shows temperatures in the 60s in northern MS and AL and the winds blowing from the north to northwest. Now, look at the second image. The colder temperatures have shifted to the east with the area of low pressure. Upper-level winds, about 30,000+ feet in the air, blow from west to east across the US, meaning most weather systems will track from California to New York. It should be noted that this is HARDLY ever the case, but I can explain that later if you ask me.

All I have done is figure out what has ALREADY happened! In order to FORECAST the weather, I need to look at sophisticated computer models. Here are a links to a fraction of the models I use: OSU MOS and Mean Sea Level Pressure GFS (there are MANY other maps to look at on this site, but just wanted to give you a feel for what I look at on the surface). These are tools for me to be able to forecast 2+ days out! I can do alright within 24 hours with the stuff mentioned above, but I need these guidance models to help me get a sense of what's going to happen the next seven days. Each model has its own biases and has to be taken into account. I also have to sit there and tell myself, "Does this make sense!?" I ask that question a lot each morning and is what makes my job fun! And no, in case you were wondering, it doesn't always make sense. Hence the fun part ;)

This should give you a general sense of what I do every morning when I step into the station. I hope you enjoyed reading through it all and if you have any questions, don't hesitate to ask!

David Reese
Morning Meteorologist
WRBL TV-3