• Radar plays an important role in determining thunderstorm severity. One can relate updraft strength with echo top height and peak reflectivity, also noting thunderstorm trends. The Lemon technique assumes moderate to strong vertical wind shear.

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• Updraft tilt caused by increase in environmental winds. Precipitation particles in the updraft fall out creating low, mid and upper level echoes to be vertically aligned.

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• On a PPI, there are no strong reflectivity gradients, and no mid-level overhang. The storm top will be downstream of the updraft with strong upper winds, but will be over the strongest low-level echoes. The storm motion is determined by the mean 1000-500 mb wind. This is usually approximated by using the 700 mb flow as a guide.
• At this point the thunderstorm needs to be watched carefully for signs of intensification.

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• As updraft increases in strength, it rises with less of a slope and ascends to greater heights. The strong updraft is able to penetrate higher without the effects of the wind shear. Precipitation forms in the mid-levels of the storm and is carried downwind of the updraft. The Weak Echo Region (WER) is shown on the RHI, marked by precipitation above weak returns. The echoes above the WER make up the mid-level echo overhang.
• On the PPI display, the echo elongates in the direction of the mean winds, while the storm top shifts over the greatest precipitation echo gradient on the right, or updraft) edge of the storm.
• In a multicell, other tops will exist. This top will now be above a strong low level reflectivity gradient on the updraft storm flank indicating either new cell development, or a sustained single updraft, as in a supercell. Mid-level echo overhang sticks out over low-level gradient by 6 to 25 km. A storm with these characteristics moves slower and veers to the right of other non-severe echoes (approximately 70% of the mean wind and 30° to the right). This echo identifies a hailstorm often with large hail (>3/4" diameter) and gusty surface winds.
• At this point there are strong indications that the storm is severe and hence a warning is likely to be issued. The deviant motion of the thunderstorm indicates that the storm most likely contains a mesocyclone. Further proof of this fact can be shown by examining Doppler products.

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• A more intense updraft will rise almost vertically reaching heights of near 60,000 ft. There are strong reflectivity gradients above the Bounded Weak Echo Region (BWER) and the storm top is over this as well. This configuration is indicative of potential tornadic activity. A BWER indicates strong rotation about a vertical axis. A horizontal cut through the storm will show the BWER as a "hole" in the reflectivity.
• If there is rotation within this storm, the rear flank downdraft will wrap around the read of the storm, carrying with it precipitation and helping to form the radar detected "hook" echo.
• The mean flow is blocked by the updraft, so heavier precipitation is carried around the updraft forming the V-notch.
• Precursor to the supercell storm is often a non-severe multicell. As each new cell becomes larger than the previous, one eventually dominates and the supercell structure results.
• A storm will not be severe unless the VIP 5 echo extends above 26,000 feet (8km), the mid-level echo is strong, and a WER exists.
• It is during the existence of the BWER and its collapse that large hail develops and then the tornado. The tornado often signals the end of the severe stage, the storm resuming a non-severe configuration again. In certain conditions, the BWER can once again develop.
• A supercell that travels to the right of the mean winds is considered to be extremely dangerous with a high potential for tornadic development. These storms are capable of changing the vertical wind profile, making it more favorable for increasing the rotation within the mesocyclone. The storm relative wind shear, or helicity, is a major concern for severe weather forecasters.