The Severe Thunderstorm Criteria Issue

Bill Murray wrote a great here on the blog yesterday about raising the bar for severe thunderstorm warning criteria. I have been an advocate of this for a number of years since I really have a hard time finding anyone who really pays attention to severe thunderstorm warnings.

I have discussed this often on our old "Weather Talk" articles before the blog format started.

Our friend Jason Kelly down in Panama City tipped us off concerning a trial NWS program in three of their offices this year. The severe hail criteria will be raised from 3/4” in diameter to 1” in diameter in Wichita, Springfield, MO, and Pleasant Hill, MO. I am optimistic that this trial will work out nicely, and I expect the NWS at some point down the road to raise the severe hail criteria to 1” nationwide. This should cut back on the number of marginal severe thunderstorm warnings.

I expect the severe thunderstorm wind criteria to remain at 58 mph due to demand from EMA officials and the public. And, I am pretty much in agreement that this criteria needs to remain unchanged. We just need to be certain that winds really are 58 mph or higher if a warning is issued based on wind.

I also would like to see one additional message created called a “severe thunderstorm emergency”. This would be used in a rare situation like a major Derecho when winds can be very widespread, and possibly exceeding 100 mph. A good example of this was when a severe storm hit Memphis during the early morning hours on July 22, 2003...winds of up to 100 mph shredded the city. Roofs of some building came off. Half the city was without power. Damages topped $6 million; cleanup costs were over $40 million. Most folks that day simply ignored the “standard” severe thunderstorm warning as usual... which was issued well before the damage started. I would suggest a "severe thunderstorm emergency" would have captured more attention.

I also believe the "tornado emergency", which is now being used informally by the NWS should be a formal part of the warning package as well. Reserved when a significant tornado is being watched by spotters and is causing significant damage. A good example of this would be the Tuscaloosa tornado of December 16, 2000, when the world was watching that big F4 on our live towercam.

Thanks to everyone who posted comments on Bill's original post... very interesting....



Snow Flurries (?) Update

In our current forecast, we mention "a few snow flurries possible overnight." Still looks that way although certainly no significant snow.

A sizeable patch of moisture is now over North Mississippi and it is being picked up on Memphis and Columbus, Miss., doppler radar. It is moving ESE. This will be the key to whether we see any flurries late tonight or in the wee morning hours. Most of what is showing on radar is not yet reaching the ground.

The base of the 500 millibar trough is now over North Mississippi and colder temperatures are moving in at lower levels such as 850 millibars (about 5,000 feet)

So there is a decent chance of seeing some o9f those elusive flakes late tonight and very early Tuesday. Don't lose sleep over it because it will not be a big deal!


Flurries Tonight?

Running a little late today as expected due to the drive up to Hamilton. Had a GREAT time with the Hamilton Middle School kids and the Kiwanis club.

The Monday afternoon video update is on the server:

http://beta.abc3340.com/weather/video.hrb

Here is a quick look at coming attractions in Alabama weather:

*Snow flurries tonight. Sure looks like it as we watch the precipitation with the next impulse rotating around the bottom of the upper air trough. Looks like flurries tonight from about 11:00 p.m. until 4:00 a.m. Most folks will sleep through them...

*Cold air air rolls in here tomorrow with an icy northwest wind and temperatures struggling to reach the low to mid 40s despite the return of sunshine. We will have a widespread freeze early Wednesday morning, with most places dropping into the 22 to 27 degree range. The coldest valleys should reach the upper teens. Welcome to March!


*The next storm system will form to the west of Alabama Wednesday night, and will bring clouds back in here Thursday. J.B. Elliott has introduced the chance of some scattered light rain on Thursday, but the heaviest stuff will probably remain to the south. Any snow on Thursday or Thursday night? Thickness values are pretty marginal for that, but we will keep an eye on it.

*The clipper system over the weekend will have to be watched as well. Those can be very pesky. The GFS shows a very strong clipper system, but one that is starved for moisture. Some light snow looks likely for Tennessee and Kentucky over the weekend, and maybe a few flakes for the Tennessee Valley of extreme north Alabama. For now we will leave our forecast dry... I will take a closer look at that this evening.

*And, the pattern flips to a stormy one for mid-month if the GFS is correct. Watch the video for details!

Have to get to work on the TV side... running about one hour behind the normal schedule today....



Heavy Snow in the East

Here is the latest on snow in the east today through Tuesday:

GREAT SMOKY MOUNTAIN REGION
Between now and Tuesday night, 4 to 8 inches accumulating. Snow will diminish Tuesday night.

EXTREME NORTHEAST TENNESSEE (MOUNTAIN CITY AREA)
Snow this morning, mixed with rain this afternoon. 1 to 5 inches accumulating today, especially higher terrain...an additional 1 to 3 inches tonight. Snow showers continue Tuesday. Total accumulations for today through Tuesday 4 to 8 inches. Quite windy especially Tuesday with gusts to 40 MPH.

WASHINGTON-BALTIMORE
4 to 7 inches accumulating today and tonight. Not real cold. Low tonight 30 and high Tuesday 40.

NORTH VIRGINIA (PLACES LIKE HOT SPRINGS)
Total 5 to 8 inches expected. Becoming windy with wind chill tonight +5

PHILADELPHIA
2 to 4 inches by nightfall, additional 2-4 inches tonight, storm total 4-8 inches.

NEW YORK CITY
2 to 3 inches this afternoon, snow continues tonight with storm total accumulation 6 to 10 inches. Light snow continues Tuesday with a high 38.

BOSTON
Snow beginning this afternoon becoming heavy tonight. Accumulation 5 to 9 inches tonight and Tuesday. May be mixed with freezing rain after midnight tonight. Winds increasing reaching gusts to 40 from the NE toward midnight. Low tonight 30. High Tuesday 35.

This same storm system triggered a Tornado Watch in Florida Sunday along with some very heavy rain:

3.40 inches at Melbourne
3.49 at Apalachicola
5.17 at Sarasota
7.30 inches in Manatee County



Into The Deep Freeze

The Monday morning video is on the server:

http://beta.abc3340.com/weather/video.hrb

We are at that time of the year when we barely have time to sit down and gather our thoughts. I am off to Hamilton today to speak to the middle school kids at 11:00, and then the Kiwanis club at 12:00. The afternoon update might be a few minutes late today due to the schedule, but it should be posted sometime between 3:30 and 4:00.

Tomorrow marks the first day of meteorological spring, but it will feel more like the first day of meteorological winter. Today won't exactly be a lovely spring day either.

Clouds, some light rain, and a chilly wind will continue across Alabama today as a push of very cold air approaches from the north. Scattered snow flurries are likely tonight over the northern third of the state, but we don't expect any accumulation or travel issues. The best chance of flurries will come between about midnight and 4:00 a.m., so most folks will sleep through it anyway.

If you want to see some snow, try Washington, Baltimore, Philadelphia, New York City, or Boston. A major winter storm will drop between 6 to 12 inches on our pals up there, with some places seeing more than one foot.

Tomorrow will be a windy and cold day as the sun returns. Our coldest morning will come Wednesday morning, with most places dropping into the 20 to 25 degree range. The colder valleys could reach the teens.

Anyone remember a week ago when the GFS MOS products were advertising 60s for tomorrow and Wednesday?????

OTHER COMING ATTRACTIONS

Last week we mentioned one, maybe two winter storm threats for the deep south during the first part of March. Unfortunately for the snow fans it is beginning to look like both of them won't be an issue in Alabama:

*Our end of the week storm should pass too far to the south to really bother us. That was our first hope for snow fans in this March cold snap. A nice wave will indeed pass through the central Gulf, but the precipitation shield should remain near the coast and over the Gulf waters Wednesday night and Thursday. We will see some clouds here, but any precipitation looks very unlikely.

*The next issue is the clipper system this weekend. The models bring some light snow southward into Kentucky and Tennessee late Saturday an Saturday night, but the system sweeps to the east quickly, and with little moisture to work with I am not going to mention anything for us at this time. Clipper systems rarely produce any significant snow in north Alabama anyway.

As we go past seven days, the NAO, while still negative, begins to trend back to neutral territory and the main trough axis shifts to the east. This suggests a gradual warming trend beyond seven days, with temperatures finally back to normal levels by mid-month. The pattern also suggests we might be getting into a stormy set-up at mid month; we have to remember this is the tornado season.

AND... don't forget our final Storm Alert 2005 show is Wednesday night this week at Mountaintop Community Church in Vestavia, not far off U.S. 31. The show begins at 7:00, and this will be the one opportunity to see the show in the Birmingham metro area. See you there!

Very interesting post by Bill Murray below... I have strong thoughts on the subject and will try to post them later today or tonight...


Too Many Severe Thunderstorm Warnings?

Are there too many Severe Thunderstorm Warnings? Many meteorologists believe that people are desensitized to them because there are so many of them. And that is probably true. The criteria for a Severe Thunderstorm Warnings is hail 3/4 of an inch in diameter or greater and or winds of 58 mph or greater. The problem with this set of criteria is that 58 mph winds do not produce widespread damage, and 3/4 inch hail (the size of a penny) rarely causes much damage. The 3/4 inch threshold was actually created for aircraft, which can be damaged by such hail when flying at 200-300 mph. But pilots do not use Severe Thunderstorm Warnings anyway.

Why are there so many? I have read statistics that say that Severe Thunderstorm and Tornado Warnings have increased by 300% since the 1980s. We certainly have better technology, especially radar to help produce better warnings. While detection scores have increased, so have false alarm rates. This may be leading to a “cry wolf” syndrome where the public stops taking warnings seriously, which could endanger public safety. At the same time, severe weather reports have increased by 250%. This is already skewing the severe weather climatology database. There are not more incidents, we just have better spotter networks, lots of storm chasers and pressure within the NWS to verify their warnings so that verification scores will increase. Some say that there should be no process of verification, only periodic justification of reasoning behind warnings.

Some say the hail criteria should be raised to 1 inch in diameter (quarter size) or even golfball size (1.75 inch) and that the winds criteria should be raised to levels that are strong enough to create significant wind damage. Protection of the integrity of the database is the reason I have heard for not adjusting the criteria.

Some say there should be an enhanced Severe Thunderstorm Warning, such as a Very Severe Thunderstorm Warning. This warning would some with higher thresholds. These would be used only in cases where an enhanced threat to life and property is suspected to exist. Currently, NWS offices can use strong wording in their warnings to communicate especially dangerous situations. Now, what is your opinion? Please respond by posting your comment on the Weather Talk Blog...


A Wet Time in My Tiny Corner

It is a cold, raw wet afternoon in my Tiny Corner of the World. By 5 PM, 0.46 of an inch of rain had fallen with a brisk wind. I love a chilly, rainy day like this but it sure does pose problems when you-know-who needs to go to the bathroom. Just took Little Miss Molly out and I tried to hang close under the eve of the house while Molly made a quick dash into the wet grass and wet it even more.

I feel guilty bailing out of church tonight--especially our current Sunday Night Bible study in the book of Mark. Howsomever, I am making good use of the extra time by catching up on some active (very active) play sessions with Molly. She just jumped up on the king-size bed, burrowed under her blue blanket wanting to play hide-and-seek. She occasionally would pop only her head from the blanket and grab at me. I owe her some extra play time.

I also stayed home because of being way behind on bunches of non-weather stuff. But I expect the combination of Little Miss Molly and the current interesting weather going on to shoot down getting much of that done.

Sometimes, I wish I wasn't interested in weather. But it is very much like "printer's ink" and "railroading" addictions.

Life goes on--wet or dry, warm or cold.


Video Update for Feb. 27, 2005

Sunday's video update is on the server. Shortly after it went up there, SPC issued a tornado watch for a large part of the Florida peninsula. A low center just south of Mobile now will be tracking east-northeast across Florida. A warm front was situated between Orlando and Gainesville at 17Z with the TBW radar showing some strong storms still offshore from the west coast of Florida. Too bad our temperatures are not about 20 degrees lower, and we could be dealing with an intersting winter situation here. But temperatures are not anywhere near freezing.

Yesterday was probably the last day for us to see 60 degree readings for a while. As the surface low goes by and the upper trough sharpens, we should be getting into a good northwesterly flow pattern with cold air streaming southeast into the area through the latter part of the week.

Hate to see the last of the Storm Alert tours coming up! It is very enjoyable to get out and talk to people. Jason and I had a great trip over to Talladega yesterday to speak to the Senior Health Day talking about severe weather safety. Had over a hundred people and sure appreciated the hospitality of the staff at the hospital there.

Lots of activities coming up this week taking me to Odenville, Cedar Bluff, Vestavia Hills, and Huntsville. Plus with James and John at the Mississippi State symposium, I'll be filling in on the Friday and Saturday weathercasts.

Stay warm!

-Brian-



Doing Something About the Weather

Mark Twin is generally credited with the famous statement, “Everybody talks about the weather, but no one does anything about it.” But Bartlett’s Quotations says there is no credible evidence of the statement in Twain’s writings. Bartlett’s says it is actually attributed to Charles Dudley Warner, a friend of Twain. According to Bartlett’s, what Warner actually wrote, in an editorial in the Hartford (Connecticut) Courant, August 27, 1897, p. 8, was: “A well known American writer said once that, while everybody talked about the weather, nobody seemed to do anything about it.”

Well, the Mayor of Moscow wants to do something about it. Or about bad forecasts at least. A long time critic of the Moscow Weather Bureau, Mayor Yury Luzhkov threatened to fire everyone in the weather office unless more accurate and timely forecasts are produced. His most recent tirade came as a result of a badly missed temperature prediction and a record snowfall that was incorrectly forecast.
Lushkov wants the forecasters to have to pay financial penalties for incorrect forecasts. The Mayor has proposed that all funding for the weather service be cut off until a contractual agreement can be agreed upon that would hold the forecasters financially liable.

Of course, perfect weather forecasts are still beyond the reach of the science of meteorology as we know it today. Even with superior technology and computer models, our knowledge of the atmosphere is still rather elementary. It will be interesting to follow this story over the coming months.


Severe Weather Symposium Next Weekend

The Fourth Annual Southeast Severe Storms Symposium will be held at the Bost Extension Center at Mississippi State University in Starkville this coming Friday, Saturday and Sunday, March 4-6.

The Friday agenda will be exclusively for broadcasters. Mississippi State features one of the premiere broadcast meteorology schools in the country.

On Saturday, the event will kick off with a focus on tropical weather. There will be four excellent presentations on Hurricane Ivan, tornadoes from landfalling tropical cyclones and the flooding from Tropical Storm Gaston in Virginia. Then Dr. Richard Knaab of the Tropical Prediction Center will give a featured talk on operational forecast improvements at the National Hurricane Center during the 2004 Hurricane Season.

The afternoon session will focus on severe weather. One of the most important presentations of the day will be by Scott Blair and Eric Nguyen of the University of Oklahoma. They captured the Mulvane, Kansas tornado on June 12th of last year. Nguyen shot what must be the most impressive photo of any tornado I have ever seen that day. It was featured on the cover of the Accord Weather Guide Calendar this year. I will get to speak about my chase experience in Harper and Sumner Counties in Kansas on May 29th, followed by an excellent presentation by Texas meteorologist Lon Curtis on enhanced Tornadogenesis. The famous Chuck Doswell will speak on the past, present and future of storm chasing. Meteorologist Jon Davies will talk about tornadoes that occur in the unusual circumstances of low humidity or low wind shear. Severe weather coverage will continue on Sunday morning with additional presentations on specific severe weather outbreaks and other technical topics. The public is welcome to attend. You can register at http://www.msstate.edu/org/nwa/SSSS.htm


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