Weather Authority declares Alert Day for Tuesday

Damaging winds, hail, lightning, isolated tornadoes possible

By Rebecca Barry - Meteorologist

JACKSONVILLE, Fla. - The Weather Authority chief meteorologist explains the worst of Tuesday's storms time-wise "will be between noon and 4 p.m. The biggest threat will be isolated tornadoes in the brief, fast-moving severe storms. Storms may also cause hail and high wind damage."

A Tornado Watch has been issued for our entire area through 7p.m. The Storm Prediction Center sums up the primary threats as isolated tornadoes and a couple intense tornadoes possible, scattered large hail and isolated very large hail events to 2 inches in diameter possible, and scattered damaging wind with gusts to 70 mph possible. 

A cold front moving through Tuesday will bring late morning through late afternoon storms, damaging winds, hail and isolated tornadoes possible.

Chief meteorologist John Gaughan is monitoring the possibility of the Storm Prediction Center issuing a Tornado Watch for our area for Tuesday afternoon, prompting a Weather Authority Day.

"Remember, a watch means severe weather possible, but not yet," Gaughan said. "A warning means it is happening."

Another wave of showers and thunderstorms will develop over the Gulf and move across our area Tuesday afternoon. The most frequent and heaviest rain will be along I-10. Strong to severe storms are possible, especially if we do not see a significant increase in clouds Tuesday afternoon and we heat up impressively in advance of the front's arrival. 

What to expect with tonight & Tuesday's storms

In addition to the daytime heat increasing our risk for strong afternoon storms, we also see an increase in vertical wind shear which could aid afternoon convection. The best chance to see severe storms will be along and to the north of I-10 and into Southeastern Georgia.

By the afternoon hours the CAPE (Convective Available Potential Energy) -- the energy available in the atmosphere for storms to feed off of will be at a high level (2000j/kg) and other factors that contribute to storms developing severe tendencies -- will be present such as increasing helicity and increasing shear.  We may see damaging straight line wind gusts that could break tree branches off and knock out power. Hail is possible, and isolated tornadoes are possible as well. 

A shortwave of energy will dive through the southeast by the early afternoon hours, providing the catalyst for storms to develop. The levels of shear in our atmosphere and the levels of energy available are forecast to be elevated by the afternoon hours as well.

Even outside of the afternoon storms, Tuesday will see breezy conditions. Southwesterly winds could reach advisory criteria, which is when winds are expected to be sustained at 35 mph or greater for an hour or more, or when wind gusts are expected withing the 46-57 mph range.

The Weather Authority is monitoring the potential for severe storms and we will keep you updated online and on air. 

Behind Tuesday's storms and the front is MUCH colder, drier air that will clear us out and turn our temperatures to the chilly side through the rest of the week. 

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