Dozens of tornadoes and dangerous severe thunderstorms tore through the Southeast U.S. on Friday, bringing a second day of severe weather havoc to the nation. The death toll from the two-day severe blitz now stands at seventeen, with up to 100 people injured and tens of millions of dollars in property damage. NOAA's Storm Prediction Center logged 98 tornado reports yesterday, bringing the two-day total for the outbreak to 120 tornadoes. These preliminary reports are usually a 15% over-count of the actual number of tornadoes, which still means over 100 tornadoes have probably touched down during the past two days. The deadliest tornado of the outbreak hit near Prattville, Alabama at 10:55pm CDT last night, killing three people in a mobile home, and injuring four others. One of the most damaging tornadoes occurred just west of Jackson, Mississippi, when a tornado touched down just south of I-20, crossed the expressway, flipping cars and semis, then plowed through the town of Clinton. At least nine people were injured in Clinton, and extensive damage characteristic of an EF-2 tornado is apparent in damage photos.
Figure 1. Radar reflectivity image of the Clinton, Mississippi tornado at 10:57am CDT as the twister crossed I-20 and hit the town. Note the classic hook-shaped echo of the parent mesocyclone in the rotating severe thunderstorms that spawned the tornado.
Figure 2. Doppler radar velocity image of the Clinton, Mississippi tornado at 10:57am CDT.
On Thursday, tornadoes and deadly severe thunderstorms tore through Oklahoma and Arkansas, killing at least nine people. A EF-3 tornado hit the small town of Tushka, Oklahoma, population 350, ripping off the roof of the local high school and destroying dozens of buildings in Tushka. Two people were killed and 25 injured. The tornado moved over farmland and dissipated a short time later, but the squall line that spawned the tornado moved into Arkansas overnight, spawning severe thunderstorm winds that killed seven more people.
Virginia, North Carolina, and South Carolina under the gun today
The action shifts eastwards to southern Virgina and eastern North Carolina and South Carolina today, which NOAA's Storm Prediction Center have placed under its "moderate risk" region for severe weather. This is the same level of risk as we've seen for the past two days for this storm system, and it is very unusual for this portion of the U.S. to experience such a high severe weather risk. Tornado watches have already been posted for portions of Georgia, South Carolina, and North Carolina. You can follow today's severe weather using our severe weather page and interactive tornado map. This map now shows links to Youtube storm chaser videos of tornadoes, plus any wunderphotos taken of the storm.
Figure 3. Satellite image from 23:32 UTC (7:32pm CDT) April 15, 2011, showing the strong low pressure system over the middle of the country that brought yesterday's severe weather outbreak. Image credit: NASA/GSFC.
Figure 4. Water vapor satellite image from 23:15 UTC (7:15pm CDT) April 15, 2011, showing a dry, eye-like feature in the strong low pressure system over the middle of the country. This eye-like feature persisted for many hours, but was not visible on infrared or visible satellite images. According to an analysis done by Scott Bachmeier at the University of Wisconsin, the stratosphere, which has very dry air, sunk down to the 600 mb height at the center of the storm, and it is possible that dry air from the stratosphere is responsible for this eye-like feature. This is a different mechanism than how hurricanes develop eyes, and yesterday's storm had only a shallow area of low clouds with light rain near the center--nothing like an eyewall of a hurricane. Image credit: NOAA.
Figure 5. Storm chaser video from Reed Timmer of the Clinton, Mississippi tornado on April 15, 2011. Numerous transformers blow as the tornado wipes out power lines, creating bright blue-green flashes.
Figure 6. Storm chaser video from tornadovideos.net of a huge tornado in Oklahoma during Thursday's outbreak there.
Jeff Masters
Plowing over the countryside on its way to Madill.
Tractor rig picked up and placed on top of the others. Taken 2 miles north of Madill.
Taken shortly after 6 p.m. on Hwy 70 looking east. The tornado hit 2 miles north of town.
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Glad to hear your fine. I remember your post from earlier this morning, saying if anything came to your area you'll try and get some pics. I guess you got more than you bargained for.
Region: NEVADA
Geographic coordinates: 38.400N, 118.716W
Magnitude: 4.6 Ml
Depth: 0 km
Universal Time (UTC): 17 Apr 2011 00:45:37
Time near the Epicenter: 16 Apr 2011 17:45:37
Local standard time in your area:
17 Apr 2011 00:45:37
Location with respect to nearby cities:
16 km (10 miles) SSW (210 degrees) of Hawthorne, NV
19 km (12 miles) WNW (302 degrees) of Qualeys Camp, NV
29 km (18 miles) SE (128 degrees) of Wichman, NV
240 km (149 miles) E (93 degrees) of Sacramento, CA
Someone tripped over the sensor? ;)
there is no warning for severe weather in NY.... there is only a SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NEW YORK NY
1033 PM EDT SAT APR 16 2011
No suggestion of severe weather only of STRONG THUNDERSTORMS WILL IMPACT BERGEN...BRONX...EASTERN ESSEX...
EASTERN UNION...FAIRFIELD...HUDSON...KINGS (BROOKLYN)...NASSAU...NEW
YORK (MANHATTAN)...PASSAIC...QUEENS...RICHMOND (STATEN ISLAND)...
ROCKLAND...WESTCHESTER AND WESTERN SUFFOLK COUNTIES.
Please refrain from over-reacting. It has been a very destructive day with many lives lost. People are on edge still and your over-reaction is not needed at this time.
The storms are moving out into the ATL.
@JimCantore
Jim Cantore
This will likely be North Carolina's Largest #tornado outbreak in History easily surpassing March 1984
Hey Dan.
I clicked on the link that accompanied the email from USGS. here is what it says.
Magnitude 4.6 - NEVADA
2011 April 17 00:45:37 UTC
Magnitude 4.6
Date-Time
Sunday, April 17, 2011 at 00:45:37 UTC
Saturday, April 16, 2011 at 05:45:37 PM at epicenter
Time of Earthquake in other Time Zones
Location 38.394°N, 118.735°W
Depth 15.4 km (9.6 miles)
Region NEVADA
Distances
18 km (11 miles) SW (214°) from Hawthorne, NV
21 km (13 miles) WNW (298°) from Qualeys Camp, NV
28 km (18 miles) SE (131°) from Wichman, NV
239 km (148 miles) E (93°) from Sacramento, CA
How can it go from 0km depth to 15.4km after analyzing the info????
95 tornado reports today, 103 yesterday, 22 on Thursday. that brings to the grand total to 220 reports from this system so far.
Take away 15% and you still end up with 187 tornadoes. Pretty impressive total.
I'm not sure if this means something but I've noticed whenever tornado seasons are active it usually means the hurricane season ends up being active. 2010 & 2008 both had active tornado seasons.
Hey Aussie, I don't understand it either. But then again, I know nothing about how seismographs really work. The basics, yes, but not specifics.
Well, off to bed, Have a good day Aussie.
Only found couple of articles on Google news, Nothing serious,
Tropical Cyclone Advisory #5
TROPICAL DEPRESSION 15F
12:00 PM FST April 17 2011
===================================
At 0:00 AM UTC, Tropical Depression 15F (1000 hPa) located at 25.0S 165.9E has 10 minute sustained winds of 30 knots. The depression is reported as moving east southeast at 17 knots. Position good based on visible imagery.
Organization has weakened and cloud top temperatures have warmed in the past 24 hours. System lies to the east of a sharpening upper trough over eastern Australia in a moderate to high shear environment. Sea surface temperature is around 25-26C.
Dvorak analysis based on shear pattern with 0.6 of a degree distance between the low level center and deep convection, yielding DT=2.5 MET=1.5, PT=2.0. Final Dvorak based on DT.
Dvorak Intensity: T2.5/2.5/W0.5/24 HRS
Global models direct the system towards the southeast with little intensification before it is captured by a front currently crossing New Zealand during the next 24 hours.
This Is The Final Tropical Disturbance Advisory from the Fiji Meteorological Services
Tropical Cyclone Bulletin
TROPICAL CYCLONE ERROL (29U)
9:00 AM WIB April 17 2011
==========================================
At 7:00 am WIB, Tropical Cyclone Errol, Category One (993 hPa) located near 10.9S 124.1E, or 50 NM south southeast of Kupangcand and 55 NM east of Rote has 10 minute sustained winds of 45 knots with gusts of 65 knots. The cyclone is reported as moving west at 3 knot.
Forecast and Intensity
========================
24 HRS: 10.7S 122.4E - 35 knots (CAT 1)
48 HRS: 11.6S 120.4E - 30 knots (Tropical Low)
72 HRS: 12.8S 118.4E - 30 knots (Tropical Low)
STRONG WIND WARNING:
For coastal waters BETWEEN TIMOR ISLAND AND ROTE ISLAND
HIGH WAVES WARNING:
For coastal waters TIMOR ISLAND AND ROTE ISLAND
So far 2011 is just above the 75th percentile for season tornado activity.
Tornado activity over the years:
Interesting to see that the number of tornadoes recorded in the United States has been increasing. This is mostly due to better spotting and reporting, and not climate change.
NWS has an inflation adjusted graph which accounts for the poor spotting ability and lack of reporting in the 1950s, and 60s.
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 1925 UTC 16/04/2011
Name: Tropical Cyclone Errol
Identifier: 29U
Data At: 1800 UTC
Latitude: 11.1S
Longitude: 124.4E
Location Accuracy: within 30 nm [55 km]
Movement Towards: west northwest [299 deg]
Speed of Movement: 2 knots [4 km/h]
Maximum 10-Minute Wind: 50 knots [95 km/h]
Maximum 3-Second Wind Gust: 70 knots [130 km/h]
Central Pressure: 991 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 50 nm [95 km]
Radius of 34-knot winds SW quadrant: 50 nm [95 km]
Radius of 34-knot winds NW quadrant: 50 nm [95 km]
Radius of 48-knot winds NE quadrant: 20 nm [35 km]
Radius of 48-knot winds SE quadrant: 20 nm [35 km]
Radius of 48-knot winds SW quadrant: 20 nm [35 km]
Radius of 48-knot winds NW quadrant: 20 nm [35 km]
Radius of 64-knot winds:
Radius of Maximum Winds: 15 nm [30 km]
Dvorak Intensity Code: T3.0/3.5/W1.0/24HRS STT:W0.5/6HRS
Pressure of outermost isobar: 1009 hPa
Radius of outermost closed isobar: 90 nm [165 km]
Storm Depth: Deep
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 17/0600: 10.7S 123.7E: 050 [095]: 045 [085]: 993
+24: 17/1800: 10.5S 122.4E: 080 [150]: 035 [065]: 999
+36: 18/0600: 10.7S 121.0E: 110 [210]: 030 [055]: 1001
+48: 18/1800: 11.1S 119.6E: 145 [270]: 030 [055]: 1002
+60: 19/0600: 11.8S 118.5E: 190 [355]: 030 [055]: 1002
+72: 19/1800: 12.3S 117.1E: 240 [445]: 030 [055]: 1002
REMARKS:
The current position is based on animated satellite imagery.
Dvorak analysis of EIR imagery remains difficult, with the LLCC located close to
the edge of the western convective band. Current DT is 3.5 based on a 1.0 wrap.
On a 24hr W trend, MET=PAT=2.5, however FT is set to 3.0 constrained by a
change of 0.5 over 6 hours. CI is 3.5 as the system begins to weaken.
The system is expected to move towards the west-northwest, over SSTs of 28-29C,
as a mid-level ridge develops to the south of the system. Consensus of NWP
indicates reasonable confidence in the forecast west to northwest track in the
next 72 hours.
Environmental wind shear remains favourable, with the 18 UTC CIMSS analysis of
4.4 m/s. Intensity is maintained at the current level for the next 12 hours,
then weakening as Errol begins to interact with land. Errol may still be at
category 2 intensity as it approaches the eastern Indonesian islands although
there is a fair degree of uncertainty in the intensity forecast, particularly if
the recent weakening trend continues.
Tornado reports do not equal tornadoes.
If you and I report the same tornado, it is two reports/1 tornado.
I'll post this again to underscore the pitfalls in using LSR's for tornado climatology:
Please note: On March 8, 2011, the proximity space/time rule is no longer being utilized to de-duplicate events and minimal filtering is now applied to the decoded reports. All comments/remarks in the LSRs are captured on the raw files and the users can decide, for their own purposes, the best way to remove duplicate reports from the LSR's.
NWS Local Storm Reports
There are already some well known issues with the climatology of severe storm reports. The cessation of most attempts at filtering duplicate reports does not help much. Convective wind and wind gusts are probably most suspect compared to tornadoes and hail. The mix of "wind gusts" and "wind damage" can also be misleading. How accurate is a windspeed estimate? Depends on who is estimating! You, me, or...bubba. If we only look at the total number of "wind events" as presented in the SPC's Local Storm Reports (LSR's) this mish-mosh of wind gusts and wind damage receives little filtering.
Trained spotter networks, Nexrad Radar, mesonetworks, and an increase in population density have obviously added to the large increases in LSR's over the last 10 years and highlight the inherent biases using LSR's to look at the climatology of severe weather.
While the pilot stays on course, the SEO monitors science instruments and communicates to the scientist the real-time weather picture, which may require an altered course.
Mission Into Ice Clouds: Q&A with MACPEX Pilot Bill Rieke
The Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) is a NASA field campaign that is investigating cirrus cloud properties and the processes that affect their impact on solar radiation. The campaign uses NASA's WB-57 research aircraft based at Ellington, Texas, to conduct science flights over Oklahoma, the southeastern United States and the Gulf of Mexico this month.
Research pilot William Rieke from NASA's Johnson Space Center, Houston, has flown more than 3,500 hours in numerous aircraft, including the F/A 18 Hornet strike fighter when he was in the United States Navy. Since then, Rieke has been a flight engineer on Boeing 727's and 737-200's for a major airline. As a pilot for NASA since 2004, he has flown the NorthropT-38N Talon jet, the 747 Shuttle Carrier Aircraft, which NASA uses to transport Space Shuttle orbiters, and the WB-57.
There are numerous high altitude aircraft, so why was the NASA WB-57 selected for this mission? Is there any advantage to a two-seater aircraft for missions? Does a project scientist sit in the other seat, and what kinds of instruction do you receive while in flight?
William Rieke: The WB-57 aircraft is a very good high-altitude platform that can take more than 6,000 lbs. of experiments very high into the atmosphere . There are two aircrew in the WB-57, a pilot and a Sensor Equipment Operator (SEO). The SEO is usually very busy taking care of the science instruments and communicating to scientists on the ground the status of our flight. Both the pilot and SEO have a preflight brief with the scientists who decide where the aircraft needs to be positioned to collect the desired atmospheric data. In flight, the WB-57 has the capability to communicate via radio or satellite phone to the mission scientist on the ground to communicate the real-time weather picture. With their input, the aircrew then plans an appropriate course.
Oh yes, I do know that...:) meant to say reports, my bad
It would be nice if they didn't change that space/time filter. Or run it and give us both versions to compare.
I think that is a most excellent task for you, atmo. Want the job?
(j/k)
Yes, there are duplicate reports. But that 180 number was arrived not by looking at reports, but by factoring in the fact that there are duplicates. The NWS says on average the amount of reported tornadoes vs the actual amount of reported tornadoes is 15% less. We have 100 tornadoes reported today, 103 yesterday, and 22 on Thursday. That's 225 total reports from this one system. Subtract 15% (34), and you get 191 tornadoes.
No you didn't, that 187 number I threw up was the 220 reports from the system so far, minus 15% (the average amount of extra reports the NWS gets).
I'm guessing somewhere between 175-190 will be the total amount of tornadoes from the system.
The 15% fudge factor was an acceptable estimate prior to the March 8th change. It may need a re-evaluation. Which may throw a significant kink in "climatology" if not addressed.
No argument that this was a very significant and historical three day outbreak
Yes, the 180+ was from your calculations, but I did leave out the word ...reports....
Yeah Aussie, I wanted to, but by the time the storms arrived they made it too dark to get anything substantial. Was crazy, from around 7 to 8 we got cut ins from the nws every 10 minutes with new warnings, it was strange very little lightning with the storms.
If that's the case then it may be more than 180.
from earlier today.
Thank you, I remember you were worrying yesterday. Everyone in your family alright?
Odd to consider the occasional huge stovepipe tornado that spends its entire life tracking across the wide open spaces of W TX without touching a thing made by man. It receives a report but is not EF classified.
Another problem has to do with classifying path length. Where does one tornado stop and another begin? It all makes me sleepy.
G'Nite all.
No family member was injured,but my sister-in-law lost her home.....thankfully she was at work...everyone is helping her out....will be ok, thanks :)
Dang, that is such a shame, glad everyone made it out alright though! Things can be replaced!
Exactly !....One of my sayings "Don't waste your love on things that can't love you bacK"....
is that right, if a tornado forms and has very violent winds yet does no damage it doesn't get classified on the EF scale?
Houses and other possessions can be replaced, lives can't.
As with the Fujita scale, the Enhanced Fujita Scale remains a damage scale and only a proxy for actual wind speeds. While the wind speeds associated with the damage listed have not undergone empirical analysis (e.g., detailed physical or any numerical modelling) owing to excessive cost, the wind speeds were obtained through a process of expert elicitation based on various engineering studies since the 1970s as well as from field experience of meteorologists and engineers. In addition to damage to structures and vegetation, radar data, photogrammetry, and cycloidal marks (ground swirl patterns) may be utilized when available.
Link
and I've been working, like a dog.....lol
I did forget about tree damage. That counts.
Yep....so true !
And it's worth it just to hear you say..
My goodness,Jason, please stay safe!
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