A powerful complex of thunderstorms will bring the risk of damaging winds, large hail, and strong tornadoes to much of the Panhandle and North Florida through Thursday.
Surface analysis Wednesday morning depicts a stationary boundary draped across the Deep South, stretching from Georgia to Texas. South of that boundary, southerly winds have allowed for dew points across the Deep South to climb into the middle and upper 70s as daytime heating warms the surface.
In the mid- and upper-levels, a fast-moving pocket of air known as a jet streak is producing winds of more than 60 miles per hour from Texas to the Mid-Atlantic. Temperatures in this region of the atmosphere are well below freezing, resulting in an abnormally explosive environment for severe thunderstorm development by mid-June standards in the Deep South.
These ingredients will combine with ample fuel for thunderstorm development, culminating in a likely widespread severe weather outbreak through Thursday.
Model guidance suggests an initial round of strong thunderstorms could develop across the Panhandle through Wednesday afternoon.
The main concern, however, is with a thunderstorm complex that is forecast to push into the Panhandle during the pre-dawn hours Thursday. Three areas of thunderstorm activity are occurring as of publishing. The first cluster of thunderstorms is located across Middle Georgia and Central Alabama late Wednesday morning. Tornado warnings and severe thunderstorms have already occurred in this initial wave of thunderstorms, prompting a Tornado Watch to be issued for Nassau County in northeast Florida until late Wednesday evening.
The second wave of thunderstorms is working along the Lower Mississippi River Valley late Wednesday morning. Finally, a third area of thunderstorms is pushing out of Oklahoma and into Arkansas. As the atmosphere continues to destabilize in the region of the stalled frontal boundary Wednesday afternoon, thunderstorms are forecast to quickly develop from the Dallas-Fort Worth Metroplex to Central Alabama.
Forecast information as of publishing depicts a line of thunderstorms approaching the Panhandle by late Wednesday afternoon, with a more powerful line of storms likely to push into the region by midnight. This second line will press southeast toward Tallahassee and the Big Bend during the early morning hours Thursday.
South of I-10 from Jacksonville to Gainesville, the line of thunderstorms is forecast to arrive around daybreak with gusty winds and heavy rain possibly impacting the Thursday morning commute. Residents are encouraged to have multiple ways to receive severe weather alerts since storms will arrive in most areas while many are asleep.
The Storm Prediction Center has a "moderate" risk, or a 4 on a scale of 1-to-5, of severe weather extending from northeast Louisiana to southwest Georgia. Most of the Panhandle north of I-10 is in an "enhanced" risk, or a 3 on the severe weather scale from 1-to-5. From Panama City to Tallahassee to Jacksonville, a "slight" risk, a 2 on the 1-to-5 scale, is present through Thursday morning. From Gainesville to St. Augustine, a "marginal" risk, 1 on the 1-to-5 scale, of severe storms is in place.
All severe weather risks are possible Wednesday into Thursday, especially in the Panhandle through Wednesday evening. The first round of storms that develop through Wednesday afternoon will be capable of producing localized areas of damaging winds and a few reports of large hail.
The risk of tornadoes through Wednesday evening will mainly be across Alabama and Georgia as storms initially develop closer to the stalled frontal boundary. Large swaths of damaging wind will be prominent with the second round of thunderstorms that arrive in the Panhandle Wednesday evening. Wind gusts could be in excess of 70 to 80 miles per hour, which could result in damage equivalent to an EF-0 or EF-1 tornado.
The atmosphere will support a rare large hail threat for mid-June in the Southeast, with the Storm Prediction Center forecasting the possibility of hail up to 3 inches in diameter across the Lower Mississippi River Valley.
Closer to the Florida Panhandle, hail could be as large as 2 inches in diameter as storms blast through overnight Wednesday. The risk of tornadoes will be present through Thursday morning, especially near and north of I-10. A few tornadoes have the capability of being long-track and violent tornadoes, especially across southern Alabama and South Georgia.
Thunderstorms are forecast to push southeast into North Florida and Central Florida through Thursday morning. As the complex evolves, the severe risk will modify just a bit.
The risk of damaging wind and large hail will persist from the Nature Coast to the I-4 corridor through Thursday morning, but the risk of tornadoes does appear less likely. Despite that, a brief tornado cannot be ruled out along and west of I-75 as storms move in early Thursday.
Storms are expected to reignite Thursday afternoon across the Panhandle as instability builds during the day. While storms may not be as organized as Wednesday's severe threat, damaging winds and large hail will continue to be a risk.
In addition to the threat of severe storms, slow-moving and training thunderstorms could result in flooding across the Panhandle. A Flood Watch is in effect for much of the Panhandle near and north of I-10 through Friday evening.
On top of several inches of rain that have already fallen in this area over the last few days, rainfall totals of 2 to 4 inches will be likely with locally higher amounts in excess of 6 inches.
With widespread severe weather in the forecast, it is important for residents to know a few severe weather terms. A "watch" means that the ingredients for severe weather or flooding are present and may develop in the hours to come.
Typically, a watch covers a large geographical area and lasts for at least several hours. Flood watches are sometimes issued a day or two in advance of a flood event, however, severe thunderstorm and tornado watches are issued only a few hours before severe storms are forecast.
A "warning" means that severe weather or flooding are imminent or occurring. Severe thunderstorm and tornado warnings tend to last an hour or less, while flood warnings can last longer depending on the situation and how severe flooding gets. Residents are encouraged to have more than one way to receive severe weather alerts.
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