Saturday, March 31, 2012

3/31 - 3pm - Severe Risk in West Tennessee

Storms are already popping up in Tennessee as a weak disturbance aloft is allowing the warm, moist air that we have at the surface to rise. A Severe Thunderstorm Watch is in effect for a good deal of West Tennessee until 9pm CDT tonight and the main risks from these storms should they become severe will be large hail and wind. With temperatures aloft being so cold the storms should be able to produce hail easily today. Might want to think about putting your car in a garage or carport if you have one.

Instability is already building across the region as you'll see on the right image. Storms have not really broken out across West Tennessee yet because a weak warm layer aloft known as the "cap" is prohibiting air from rising. Once we get a degree or so warmer that cap should erode and storms will form. This will not be a tornado day because wind shear is very, very weak.

Check out my forecast from this morning on WBBJ below:

Be sure and catch me on 7 Eyewitness News again this evening at 6 and 10 o'clock!

Tuesday, March 27, 2012

3/27 - Ryan's Top Weather Apps

Lately I've been fielding questions from quite a few people who want to know what weather apps I use on my smartphone and tablet. With the ever-growing number of mobile devices there is similar growth in the weather app market and it's difficult to keep up with all the new apps. The apps listed below are ones that I use on my mobile devices as a student of meteorology, a broadcaster, and a storm chaser. Some of these apps are great for everyone while others are more suited to die-hard weather geeks and professionals. I'd like to point out that I use an iPhone and an iPad, but I've indicated which of the iOS apps that I use are available for Android too. I've not listed prices for these apps, except for the free ones, since they are subject to change.

RadarScope - (iPhone/iPad and Android)

Radarscope is by far the most feature-packed weather radar viewing app for mobile devices at the moment. I've been using this app since it was released in 2008 and have been impressed with the subsequent updates that have been applied since. This app is so powerful because it allows you to view radar products like base reflectivity, base velocity, VIL, echo tops, and now even dual-pol products like differential reflectivity and correlation coefficient. If you don't know what any of that means and just want a simple radar app to show you where you are in relation to the storms around you, this is still an app for you. It even displays weather warning polygons, which is essential because you're able to easily see which storms are severe near your location or anywhere else in the US. If you're a die-hard weather geek or storm chaser, this app also accepts packaged weather data plans from AllisonHouse for expanded capabilities. There's even a Mac version of this app that many use in place of the famous GRLevelx suite of radar apps for Windows that cannot run on a Mac.

MyWarn - (iPhone, Android coming soon)

MyWarn is a newcomer to my phone since it just came out earlier this month. Efforts to turn your smartphone in to the equivalent of a NOAA Weather Radio have been made with other apps before, but this app does it differently and simply. MyWarn's one and only function is to alert you when severe weather watches and warnings are issued for your current location, much like a real weather radio. The interface is very clean and there are quite a few settings in the app that allow you to customize which alerts you want to receive. Something I really like about this app that I've not seen in others is that it will alert you when the Storm Prediction Center issues a severe weather risk for your area, which gives the user a lengthy heads-up that severe storms may be an issue later in the day. The alerts are shown in graphical form once you open up the app so that you can see where exactly where you are inside the watch or warning area. The app's simplicity is what caught my attention because users generally don't want to fiddle with complicated setup wizards and a daunting number of customizations. MyWarn is available as a one-time purchase right now, but it will become an annual subscription service for users who purchase after May 31st, 2012.

Weather Underground - (Free - iPhone/iPad [WunderMap] and Android)

Weather Underground has an impressive app because it leverages a few key features that other general weather apps don't have. Besides displaying a computer-generated for your location and a weather radar, which just about every other major weather app does, Weather Underground's app displays weather observations from their network of over 24,000 personal weather stations around the world. This means that you can get more precise current observations for your location because chances are one of these neighborhood weather stations are closer to you than the official observations. The app also displays live weather webcams from users who have opted to put those online along with their current weather data. Finally, and most impressively for weather geeks, is the ability to listen to live streaming audio from NOAA weather radio stations across the country on the smartphone edition of the app. These audio streams are crowd-sourced much like the observations and webcams, so your mileage may vary with availability of these streams for your area.

Soundings Mobile - (iPhone/iPad)

Soundings Mobile is an app that I've only found recently and is mainly aimed at die-hard weather enthusiasts, meteorologists, and storm chasers. This app allows for viewing of both observed and forecast atmospheric soundings at any location where the National Weather Service sends up daily weather balloons. This app displays Skew-Ts and hodographs and even shows a box of stats like CAPE, CIN, LCL, etc that you would find at the bottom of most sounding output pages online. The intriguing thing about this app is that the soundings displayed are not images ripped from the SPC or another online source but rather rendered on the device from the raw data. This means that you can zoom in on and manipulate the sounding without distorting the quality of what you're looking at. This app is great on the iPad but performs well on the iPhone too with an interface adapted for the smaller screen size.

WeatherGeek Pro - (iPhone/iPad and Android)

WeatherGeek Pro is for, well, weather geeks! It is a fairly simple forecast model viewing app that displays model output from the GFS, NAM, SREF, WRF, and RUC models directly from the National Centers for Environmental Prediction. As an added "bonus", you can view MOS output for any location within the app. This is a great app if you need to keep up with the latest model runs without the added frustration of navigating NCEP's website on a small screen. This is not an app I'd recommend unless you have some experience with weather models and forecasting.

These are five apps that I use frequently, but this doesn't mean that there aren't other good ones out there. Leave a comment on this post with your favorite weather apps!

(Disclaimer: I did not receive compensation for or was asked to post this list of apps. These apps are merely ones that I use and enjoy personally and I receive no financial incentive for mentioning them on this blog.)

Saturday, March 24, 2012

3/24 - 3:30pm - Another Very Warm Week Ahead

A few showers have moved through West Tennessee this morning and we're still holding on to a chance for a few more mixed with some thunderstorms developing this afternoon. There could be a strong storm or two, but it shouldn't be a big deal. Once the big upper-level low generating the showers and this afternoon's storm chance moves on through we'll be seeing clearing skies and temperatures in the mid 70's by tomorrow. The early part of your workweek looks sunny as high pressure builds in once again and we should see highs go 80+ once again by Tuesday. The middle and end of the week are somewhat in question right now, but it seems as though another slow-moving system may generate at least a few showers and storms during that time frame. Check out one of my weathercasts from this morning's Good Morning West Tennessee broadcast on WBBJ for more details:

Thursday, March 22, 2012

3/22 - 4:30pm - Heavy Rain is Gone, but Warm Temps Remain!

Heavy Rain

Did you get drenched? I think we all did. The rain over the past 24 hours has been tremendous, especially across Mississippi as inches and inches have fallen from the pesky system that has been slowly churning through the Plains and now the South. Check out the estimated rainfall map from today below to see what I mean (the totals for West Tennessee are underdone but you get the picture of who saw some tremendous rainfall earlier today!) Most of the rain is now east of West Tennessee and North Mississippi, but a few showers remain and will continue this evening.

More rain will fall tomorrow afternoon as another piece of energy from the same system rotates around the Mid-South. The area in red with the directional arrow coming from it is called a vorticity max. Usually the area where rain and storms develop is east of the vort max as it moves along. Tomorrow's rain won't be as heavy as today's by any stretch of the imagination and it will be more of a scattered nature than today's washout. Once this rain is all said and done by Saturday morning we should be left with a very nice weekend and temperatures warming back up through the upper 70's across West Tennessee and North Mississippi.

The Big Picture

Let's zoom out more and look at the system that's been causing all of this rain as a whole. What we have is an upper-level low in the Plains that is slowly moving eastward. An upper-level low like this one is basically a ball of cold-air that gets cut off from its northerly source because the jet stream kicks north leaves whatever is in the base of the former trough behind. It moves slowly because the jet stream, which usually drives big weather features, is absent from the process after the low gets cut-off. The satellite and radar images coming in from area where the low is are striking... you can see very well the rotation of the low pressure center, which makes it look like a land-based hurricane.

The jet stream being way up north is also why it's been so warm lately. In the winter the jet stream usually dips down from Canada and brings cold air to the USA. Areas north of the jet stream remain cold due to the influence of an arctic air mass while to the south of it there is usually a warm, moist air mass. This winter and now into this spring the jet stream has not really come down from Canada to the eastern half of the nation. The West has had it come down a few times though, which meant snow and cold temperatures for the Pacific Northwest and even down through California. The reason the jet stream stayed so far north is that La Nina (colder than usual ocean temperatures off the coast of Peru) remained pretty consistent throughout the season. In an El Nino pattern, the jet stream comes down to the US with a vengeance.

Record Warmth

The above-average temperatures from this pattern will persist for quite a while it looks like. A cursory glance at some of the long-range models shows that the jet stream will remain somewhere close to this northerly position for the foreseeable future. With that said, comparing this year and month to years past is incredible. This March so far has been the warmest on record in Jackson, TN and Tupelo, MS and the second warmest in Memphis. Jackson is running 10.6 degrees above average for this March. Comparing the year so far to years past, this is the warmest year so far in Memphis and Tupelo, and the second warmest so far in Jackson. These are remarkable numbers and we'll likely see more of these records flash by as the warmth continues. A running list of how this year's heat compares to previous records is available from NWS Memphis.

Wednesday, March 14, 2012

3/14 - 11:55pm EDT - Record-Breaking Warmth

The warm weather we've been seeing across the region hit record-breaking levels this afternoon. Here is a list of some broken temperature records today:

Jackson, TN: High 84° | Previous Record 80°
Memphis, TN: High 82° | Previous Record 80°
Chattanooga, TN: High 83° | Previous Record 81°
Louisville, KY: High 82° | Previous Record 80°
Paducah, KY: High 82° | Previous Record 78°
Evansville, IN:
High 82° | Previous Record 77°
Indianapolis, IN: High 81° | Previous Record 79°

Many other cities in came close to breaking records, especially in Alabama and Middle Tennessee. The ridge over the Eastern US that's funneling all the remarkably unseasonable temperatures into the area will stay put through the weekend, but a few shortwave disturbances aloft will bring storm chances to much of West Tennessee, North Mississippi, and even into Central Kentucky tomorrow and Friday. These storms will be more organized than the spotty ones that developed in eastern portions of West Tennessee and even up through Western Kentucky this afternoon. The crazy-warm temperatures are going to last at least another full week as this strong ridge stays put, so I think to say that spring (or even summer) has sprung before winter officially ended!

Wednesday, March 7, 2012

3/7 - 7:45pm - Heavy Rain, Just in Time for Spring Break

A cold front moving Mississippi on Friday will bring some heavy rain to the area, but this will come after some warm temperatures in the mid 70's and showers on Thursday in Starkville. Temperatures will only get into the 50's on Friday as the front moves through, but the weekend should be warmer as southerly flow returns highs into the 60's. A few showers may linger into Saturday, but Sunday and Monday look to be very rainy right now in the Golden Triangle. The bulk of the rain will move out on Tuesday, but multiple shortwave disturbances aloft will trigger more shower chances throughout next week. By the time we're done with the heaviest rain on Monday we could be talking about well over two inches of rain accumulation. A lot of folks are saying "of course it would rain" for the start of spring break here at Mississippi State. Parts of West Tennessee could see three or more and the Delta region of Mississippi could go four inches plus according to the HPC's outlook on the left. That's a pretty big rain event!

Today's Mississippi State weather forecast video is not a typical one because our broadcast meteorology class did some challenging exercises today. My video below features a graphics lineup with few slides thrown in that I did not know about until they popped up on the screen. This is a great way to practice ad-libbing and prepare for situations when weather graphics programs malfunction on air. I think I was able to hold it together pretty well considering that I had to navigate a weather show that had no numbers in it and some redundant graphics. Check it out!

Tomorrow I leave with the Mississippi State University Distinguished Scholars on a trip to Atlanta, Georgia. We'll be there for the next few days touring the city and visiting a couple universities. Should be a fun trip! I'll be on my way to Louisville after we get back to enjoy the rest of my spring break. It's been almost two months since I've been home, so spring break is a welcome reward for all the hard work I've been doing lately!

Saturday, March 3, 2012

3/3 - 9pm - A Much Quieter West Tennessee Forecast

West Tennessee was spared from the bulk of the severe weather yesterday. As the cold front pushed through last night much cooler air filtered into the region and we'll see more seasonable weather for the next few days. It will also be quiet compared to the last couple of weeks, so be sure to enjoy these few days of sunshine! Check out your latest forecast from this morning's edition of Good Morning West Tennessee Saturday on WBBJ below:

Friday, March 2, 2012

3/2 - 12:30am - Severe Weather Outbreak Likely

A potent severe weather setup looks likely this afternoon and evening for Tennessee, Kentucky, Alabama, Mississippi, and even parts of Indiana and Ohio. All the ingredients are coming together for what could be a sizable tornado outbreak in these areas, especially around Middle Tennessee and Central Kentucky, maybe extending into Indiana too. We've had severe weather in some of these places just earlier this week, but this setup looks to be even more potent than that. Cities like Louisville, Lexington, Cincinnati, Nashville, Bowling Green, KY, Huntsville, Jackson, TN, Tupelo, MS, Starkville, MS, and Birmingham need to be on the lookout today.

Risks and Timing

The Storm Prediction Center has outlined a Moderate Risk area for severe weather tomorrow in an expansive area of the South. This includes a 15% tornado risk. Storms will likely erupt early this morning as a warm front surges northward and bring a hail risk to West Tennessee while not-as-strong storms will affect the most of the remainder of Kentucky, Tennessee, and Mississippi. These storms shouldn't be a huge deal, but a few might reach severe limits.

A brief break in the action throughout the mid and late morning hours should provide enough recovery time for the atmosphere to recharge and re-fire storms around noon. These storms will try to get going in West Tennessee and Northeast Arkansas, but will gain strength as they hit areas of greater surface heating to the east. These are the storms that could be very bad in a lot of areas. The worst tornado threat throughout the afternoon will be in Central Kentucky and Middle Tennessee, but there's a secondary area that could have tornado problems in Northeast Mississippi into North Alabama if a little more low-level wind shear comes into play. The Storm Prediction Center's latest severe weather outlook seems to pick up on that secondary tornado risk area by extending the Moderate Risk down to East Mississippi and Alabama. Straight-line wind damage and hail will be possible throughout the South tomorrow, so even if you're not in an area where tornadoes will be likely you need to be on the lookout for severe storms. The storms should move out quickly tomorrow evening once the cold front accelerates southeastward through the region.


The reason why Central Kentucky to Middle Tennessee will be the area for maximum tornado potential tomorrow is because of an alignment of a few factors. For one, the fastest upper-level winds will be centered right over this area tomorrow afternoon. When you couple that with almost southerly winds (may be a bit southwesterly at times), you get not only a high difference between wind speed aloft and at the surface, but also a difference in direction. This is called wind shear and it's crucial to sustaining a thunderstorm and allowing it to become strong enough for tornado development. The southerly winds at the surface will help what's called low-level wind shear, and that's usually a pretty big factor in who gets tornadoes.

These southerly winds will also be bringing in moist air from the Gulf, which is the fuel for these storms as they develop. While the best moisture will be over Mississippi, Alabama, and Tennessee tomorrow, it will still be ample for serious severe weather in Kentucky. This moisture will bring some serious atmospheric instability to the region. When you couple this instability with helicity (the tendency for the atmosphere to rotate), you get what's called the Energy Helicity Index (EHI). This is a decent indicator of where the best tornado ingredients will be, and as you can see on the left, the values are particularly high tomorrow across a pretty vast area from Mississippi through Kentucky. Supercells appear likely in Tennessee and Kentucky, but Northeast Mississippi may have more of a mixed supercell/squall line of storms scenario due to less wind shear. This could be an entirely linear squall line event across Northeast Mississippi/North Alabama tomorrow if wind shear under performs. While squall lines don't harbor as many strong tornadoes, it is still a very real threat that needs to be monitored.


Before severe weather
  • Make sure your cell phone is charged in case you lose power
  • Have flashlights with fresh batteries ready to go. Your cell phone should NOT be your primary flashlight
  • Your NOAA Weather Radio/Cell phone alert app should be ready to alert you
  • Make a central meeting location for family members should you lose communications after the severe weather passes
I've said before that I like iMapWeather Radio on the iPhone for weather alerts. This is not any sort of endorsement, but it is an app that I use and it just works.

When a Tornado Warning is issued for your area
  • Get to the lowest level of your home, apartment, or office
  • Stay away from windows and try to get to the center of the structure you're in
  • Evacuate mobile homes and get to a safe, sturdy building immediately
  • Make sure you are wearing sturdy shoes
  • If you have time (have these ready to go before a warning is issued), put bicycle helmets on the kids and yourself. Quite a few deaths were caused by head trauma in last year's tornadoes.
Please heed ALL warnings. This is a dangerous severe weather setup that needs no playing around with.