Flooding Risks from Tropical Moisture Across the Intermountain West and East Coast

Tropical moisture from Isaias and Rachel will impact portions of the Intermountain West and East Coast states. Flooding, gusty winds and even a threat for severe thunderstorms and tornadoes are possible. Meanwhile, record warmth will spread northward across the Mississippi Valley the next few days. Looking for snow, the first winter storm of the season is underway across the northern Rockies. Read More >

Automatically generated image showing areas of storm relative helicity.


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4 Panel Display | Animated Loop

Helicity (0-1 Km)

This is the 0-1 km (approximately 0-3,000 Ft. AGL) storm relative helicity which is a measure of the amount of low level wind shear available for tornadogenesis. This is not a good indicator of supercell potential which is related more strongly to 0-6 KM vertical shear. Values greater than 100 m**2/s**2, do suggest an increased threat of tornadoes provided a supercell is present. Larger values are generally better, but there are no clear "boundaries" between non-tornadic and significant tornadic supercells.

The arrows indicate the approximate right supercell storm motion using the Bunkers technique.

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Flooding Risks from Tropical Moisture Across the Intermountain West and East Coast

Convective Parameters - Helicity