Because of tonight’s tornado outbreak, the tantrum of the week will be posted sometime tomorrow.
Right after moving near Stillwell, GA, this cell developed an enhanced reflectivity signature over its couplet. The radar is slicing it at 1200ft AGL, so this is not at all a good sign. Pray for the best.
GAC103-SCC053-160230-
/O.CON.KCHS.TO.W.0017.000000T0000Z-080316T0230Z/
EFFINGHAM GA-JASPER SC-
946 PM EDT SAT MAR 15 2008
…A TORNADO WARNING REMAINS IN EFFECT UNTIL 1030 PM EDT FOR CENTRAL
JASPER AND SOUTHERN EFFINGHAM COUNTIES…
AT 943 PM EDT…NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO. THIS TORNADO WAS LOCATED NEAR EBENEZER…OR
ABOUT 9 MILES EAST OF SPRINGFIELD…MOVING EAST AT 45 MPH.
AT 943 PM EDT…TRAINED WEATHER SPOTTERS REPORTED A POSSIBLE TORNADO
5 MILES SOUTHEAST OF CLYO.
SOME LOCATIONS IN OR NEAR THE PATH OF THIS STORM INCLUDE…
HARDEEVILLE…JASPER…PURYSBURGH…SWITZERLAND…EBENEZER…
RINCON…SPRINGFIELD AND STILLWELL.
IN ADDITION TO THE TORNADO…THIS STORM IS CAPABLE OF PRODUCING
LARGE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.
THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION. THIS
STORM IS CAPABLE OF PRODUCING STRONG TO VIOLENT TORNADOES. IF YOU ARE
IN THE PATH OF THIS TORNADO…TAKE COVER IMMEDIATELY!
EDIT: Latest scan is +68/-30 at 1286ft AGL.
That is an extremely intense couplet at ~1500ft on KCLX radar in Effingham County, GA. There is a tornado warning for this cell. Many tornadoes have been reported today, with several injuries and fatalities. The threat will diminish as the cells shift offshore during the next several hours.
Major tornado outbreak is ongoing across GA and SC. Many reports of severe damage have come in during the day. Multiple supercells are in place from Charleston, SC, to Warner Robins, GA. With SBCAPE of 1000-1500J/kg and 0-1km SRH of 400-650m^2/s^2, the threat for long-tracked, violent tornadoes will continue.
I have to run off to an advanced storm spotter training and conference, so I’ll make this quick.
Both the NAM and RUC are extremely alarming for the threat of strong-violent tornadoes today. Both have an unstable atmosphere in place with INCREDIBLE low-level shear. They also depict a possible mesolow moving across the region, which is a classic signal for violent tornado outbreaks of this sort. The MCS moving through this morning is rapidly clearing out from west to east and should not impede instability.
I fully expect several long-tracked, strong-violent tornadoes across the SPC moderate risk area. Be very, very careful if you are in the vicinity.
I don’t have enough time for a full outlook, but I will post my thoughts here.
The NAM seems hell-bent on creating a very interesting day today along the warm front. It brings a plume of 60°F dew points up to central Arkansas, northern Mississippi, and northern Alabama. Coupled with warm temperatures and very cold air aloft, this would create a very unstable atmosphere, with SBCAPE of 1500-2500J/kg.
There will also be a large amount of wind shear in the atmosphere, especially the low-levels. 40-50kt of 0-6km shear will be in place across the warm sector, with 0-1km SRH of 200-300m^2/s^2 across the most weakly-capped areas of far eastern Arkansas and northern Mississippi by 06z. Any surface-based storm in that environment will have strong-violent tornado potential, with new STP values of 4-6 across the region.
Everything is dependent upon the cap and whether or not there will be a sufficient lifting mechanism to break the cap across eastern AR or northern MS. For now, I tend to agree with the SPC outlook, though I do think a 10% hatched tornado region is necessary. If it becomes more clear that the cap will break, then a moderate risk will be necessary.
Stay safe.
Yesterday, an EF2 tornado killed a woman at Lake City, FL, when a tree fell onto her mobile home.
The exact same thing happened with the previous killer tornado, an EF1 at Leeds, AL, on February 26th.
Year after year, people are reminded of the safety rules for tornadoes. One of the biggest that is always emphasized is to leave mobile homes in the event of a tornado. But year after year, the highest fatality totals occur in mobile homes. So far this year, 41 of the 67 direct tornado deaths occurred in mobile homes; last year, the fraction was 52 of 81.
What more can possibly be done to spur people to take tornado threats seriously? The NWS does all it can to spread the word on tornado safety. The media always reminds people what to do in tornado situations. A strong focus needs to be put on education of tornado safety in schools aside from where to go for the tornado drill. Tornado safety training needs to start early.
And that’s Tony’s Tantrum of the Week for this week. Stay safe.
Hurricane Warning
Hurricane Warning Seasonal Forecast
The 2008 North Atlantic Hurricane Season is rapidly approaching now, with less than 3 months until the season starts on June 1st. This means it is time for the second annual Hurricane Warning Hurricane Season Forecast. Last year’s forecast was fairly successful, with a call for above average activity with 11-14 named storms, 6-9 hurricanes, and 3-5 major hurricanes. There were 15 named storms storms in actuality, with only 14 fully tropical storms, 6 hurricanes, and 2 major hurricanes.
El-Niño Southern Oscillation (ENSO)
The first factor that will be considered for the 2008 hurricane season forecast is ENSO. ENSO is a large scale oscillation of ocean temperatures in the Pacific between warm and cold that has effects on the weather across the globe. In recent months, a strong La Niña has formed, which is the cold half of the ENSO cycle. The strong La Niña can be seen on the chart below; it is the area of cold water anomalies stretching from South America to the western equatorial Pacific.
A La Niña usually results in lower wind shear across the North Atlantic, providing an environment more favorable for tropical cyclone formation and propagation. The question then arises, will the La Niña continue through the hurricane season? My forecast is for the La Niña to continue into the hurricane season since it is very strong at this point but, it should start to weaken towards ENSO neutral (a relative lack of ocean temperature anomalies) towards the latter part of the season. The models that are used to predict ENSO (below) are in agreement with this assessment, although it should be noted they are subject to large errors.
Sahelian Rainfall Anomalies
The Sahel of Africa is considered a birth place of tropical cyclones. Every year, dozens of tropical waves depart Africa for the Atlantic from this region, sometimes becoming monstrous Cape Verde hurricanes. This has spawned research into the rainfall patterns of the region, in order to determine if they have any effect on tropical cyclone formation in the Atlantic. Sahelian rainfall has been below average during the last year over the southern Sahel, with the northern Sahel experiencing near normal to even above normal rainfall. In the figure below, I have put a black circle around the coastal region of the Sahel because that is the part of it which I believe is the most relevant to tropical cyclone formation. My theory is as follows. Drier than normal conditions over the coastal Sahel cause easterly waves to become drier and hotter just before they enter the Atlantic. This results in a greater temperature difference between the wave and the water, which can then help the wave become more significant and perhaps provide the extra nudge that will result in it becoming a tropical cyclone down the road. Of course, a dry Sahel is a double edged sword, and it will likely contribute to Saharan Air Layer (SAL) outbreaks. However, since the northern Sahel is near normal to wetter than normal, the more sandy part, maybe that will inhibit SAL outbreaks at the same time. It is up in the air, as always, on how much of an affect the SAL will have on tropical cyclones in the Atlantic this year. This is because the SAL likely depends on other factors than rainfall in the Sahel, such as the strength and position of the Azores high.
Normals and Adjustments Based On Current Factors
There are normally 10 named tropical cyclones in the Atlantic, 6 hurricanes, and 2.5 major hurricanes (according to the National Hurricane Center). The first adjustment for this season that I will make is +2 named storms since in recent years we have been finding tropical cyclones that we wouldn’t have normally found in the past, due to their size and sometimes remoteness. The next adjustment will be another +2 named storms due to drier than normal Sahel conditions. I will finally add another +3 for La Niña. Normal ratios will then be used to determine the amount of hurricanes and major hurricanes.
The Forecast
Named Tropical Cyclones: 16-18
Hurricanes: 8-10
Major Hurricanes: 3-4
Essentially I’m calling for a well above average season, probably more active than last year.
This supercell is near the Padre Island National Seashore in Kieberg County, TX. The situation in TX today is a little more intense than first expected. 50kt of deep-layer shear is in place across an environment of 150-250m**2s**-2 0-1km SRH and 1000-1500J/kg SBCAPE. A few supercells have formed, and there have been unconfirmed reports of tornadoes. More of the same can be expected through the afternoon hours before the front pushes through.