THEWEATHERMOGIL:: Stormy times for southwest Florida
The first in a series of storm systems and strong cold fronts will be affecting southwest Florida today (Jan. 15, 2015). Heavy showers and thunderstorms, a few of which may turn severe, are on the menu. While this mainly includes strong, gusty thunderstorm winds (up to 60 miles per hour), tornadoes cannot be ruled out, given several dynamic and thermodynamic factors. NOAA’s Storm Prediction Center has placed parts of the Florida peninsula and panhandle in a marginal risk of severe weather today (Fig. 1).
First, a very strong jet stream is located across northern Florida at around 30,000 feet above ground level. Computer models forecast the strength of this jet to increase, with winds topping 130 knots (150 miles per hour) by later today.
Next, low-level dew points (a measure of atmospheric moisture) have jumped across the Florida peninsula and eastern Gulf of Mexico during the past 24 hours. Tampa, FL, for example, has seen its dew point jump from the upper 30’s to the lower 60’s. Naples, FL has had a similar jump. In the northeastern Gulf, a data buoy (#42039) has also seen its dew point jump dramatically.
Earlier this morning, a warm front passed the data buoy. When it did, winds shifted to the south and increased to 30 knots (35 miles per hour). Atmospheric pressure has tumbled at the data buoy and at points to the northeast (Fig. 2). At the data buoy, the pressure fell 6.4 millibars (0.20 inches of mercury) in three hours.
Collectively, these factors favor severe weather, especially as the day temperatures start to rise, further fueling low-level instability.
In addition to the severe weather risk, winds and waves will pose coastal and boating issues along the southwest coast, but especially from Lee County northward. Gale warnings, even at places near the coast, are in effect from just north of Fort Myers to the Florida Panhandle. High surf, rip current and lake wind advisories are also in effect (Fig. 3).
Once this system clears the area later today, look to the west for another system to take almost the exact same track across the northeast Gulf late Saturday and Sunday. This system will also bring strong winds and the risk for severe weather.
Then, sharply cooler and more pleasant weather will return. However, given the position of the upper level jet stream, skies will be partly to mostly cloudy into mid-week.
© 2016 H. Michael Mogil
Originally posted 1/15/16