**Every accomplishment starts with the decision to try.**
LARGEST QUAKES so far today -
5.0 VOLCANO ISLANDS, JAPAN REGION
5.0 PAGAN REG., N. MARIANA ISLANDS
5.1 OFFSHORE EL SALVADOR
5.1 CENTRAL EAST PACIFIC RISE
Yesterday, 3/18/15 -
5.2 WESTERN XIZANG
TROPICAL STORMS -
* In the South Indian Ocean -
Tropical cyclone Joalane is located approximately 624 nm east-northeast of St Denis.
SEVERE RAIN STORMS, FLOODING, LANDSLIDES -
Rare Supercell Storms Rip Through Midwest on Their Way East - As many as 30 million people were in the path of the spring's biggest storm yet — a monster stretching Wednesday from the Gulf of Mexico to Canada and east to the Atlantic Ocean, which was already dropping giant hail on parts of the Midwest and threatened the greatest likelihood of tornadoes anywhere in the country.
Brief tornado warnings dotted Missouri and Indiana as the system began coalescing into what meteorologists call "supercells" — intense thunderstorms buoyed by cyclone-like rising winds. They're they least common but most dangerous kind of thunderstorm. "There'll be a lot of supercells. That's why we have the tornado threats. That's why we have the hail threats."
The danger zone for twisters Wednesday included parts of Kentucky, Texas and Oklahoma in addition to Missouri and Indiana. Thursday, the highest danger is expected to shift east, toward Chicago, St. Louis, Missouri, and the Great Lakes. Franklin County in Ohio canceled a scheduled test of its tornado siren system Wednesday, because it might be needed for the real thing. "This has the potential to be the most widespread severe weather event so far this spring."
Thunderstorms began rolling through parts of Indiana, Kentucky and Missouri on Wednesday morning, followed by hail and damaging wind in the afternoon. Intense lightning struck Wednesday in Nelson County, Kentucky, ahead of winds that put parts of the state and southern Indiana under tornado watches through Thursday morning.
Grapefruit-size hail fell around the eastern Missouri town of Sullivan about 2:30 p.m. (3:30 p.m. ET), smashing car windshields and damaging some homes. Roofs were blown off buildings and hoods were torn off vehicles in nearby Potosi, Missouri, as a storm moved through with near-tornado winds Wednesday afternoon. The two days of forecast severe weather followed several outbreaks Tuesday that saw flooding in St. Louis and two tornadoes in Kansas.
Significant Tornadoes Possible on Wed; Widespread Severe Weather Expected on Thursday - A batch of scattered but potent supercell thunderstorms should erupt late Wednesday afternoon and evening across parts of the central and southern Great Plains into the lower Missouri Valley. At 11:30 am CDT, NOAA’s Storm Prediction Center (SPC) placed a swath from roughly Wichita, KS, to Columbia, MO, under a moderate risk of severe weather for Wednesday, with lesser risk categories extending from northern Oklahoma to West Virginia. Significant tornadoes (EF2 - EF5 on the Enhanced Fujita Tornado Damage Scale) and very large hail (greater than 2” in diameter) are a possibility.
As of 11:30 am CDT Wednesday, a large part of the central U.S. was under various risk categories for severe weather in the afternoon and evening. This potential outbreak has been well predicted by forecast models for several days. Ample moisture and favorable jet-stream flow from the southwest have been in place since Monday, leading to a few pockets of severe weather already.
SPC logged more than 50 preliminary reports of 1” to 2” diameter hail as far north as southern Minnesota, where moist air from the Gulf of Mexico flowed atop much chillier surface air. One complex of severe storms moved from eastern Missouri to Kentucky on Tuesday afternoon, dropping baseball-sized hail in the central Kentucky town of Garrard and dousing Louisville, KY, with another 1.21” of rain on top of the 14.62” it had already received since March 1. Damage surveys on Wednesday confirmed two tornadoes from this complex southeast of Lexington, KY, and two others were reported on Wednesday night in far southeast Kansas.
Thunderstorms continued on Wednesday morning along and near a broad east-west frontal zone extending from central Missouri into southern Ohio, with two severe thunderstorm watches in effect by late morning. A major upper low that gave much-appreciated snow and rain to California is now making its move into the central states, which will help trigger Wednesday’s main round of severe weather. A piece of energy from the low will sweep across a constellation of boundaries in the OK/KS/MO region. These included a dry line in northwest Oklahoma and the east-west frontal zone, which was pushed into northeast Oklahoma by late-evening storms on Tuesday, then began lifting back north into Kansas and Missouri as a warm front on Wednesday morning.
Scattered thunderstorms should form along or near these boundaries by Wednesday evening, with several rapidly becoming supercells that could spawn tornadoes. The sheer number of storms may be limited at first by a capping layer of warm, dry air several miles high. Weaker storms have formed above the cap in western Oklahoma, which may diminish the risk somewhat along the dry line. However, the amount of instability and wind shear on hand by evening, especially toward southeast Kansas and southwest Missouri, favors the emergence of supercells (long-lived, discrete thunderstorms that produce the lion’s share of stronger tornadoes). The cool low-level air pushed out from any storms that develop could provide boundaries for additional storm formation.
Severe threat shifts to Midwest on Thursday - Tornadoes are also possible on Thursday as the upper low and associated frontal system accelerate northeast toward the Great Lakes. By afternoon, a strong cold front should be plowing east across Illinois, with the east-west frontal zone now sweeping north into Wisconsin and Michigan as a warm front. These boundaries will help focus intense thunderstorms across a broad area, probably more numerous than on Wednesday, with long-lived supercells possible. Wind shear will be stronger than on Wednesday, but it remains to be seen how well the atmosphere manages to recover from the cooling effect of Wednesday night’s storms upstream.
If the air does warm up enough to become at least moderately unstable, models suggest that the powerful upper system could trigger a north-south line of fast- moving supercells across Illinois, eventually becoming a solid line with heavy rain, hail, and high winds. Other dangerous storms may form along the warm front. The overall system’s increasing speed will put much of the Midwest and the Mississippi Valley in line for one or more quick shots of potentially severe weather. As of 12:30 p.m. CDT Wednesday, SPC’s enhanced-risk area for Thursday includes an unusually large swath from northeast Texas to eastern Ohio.
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