When southwest Florida residents and visitors awake this Thursday morning, they’ll discover that the weather is much different than it has been. Brisk northwesterly winds, coupled with sharply cooler and lower dew point air, has invaded the region. As the strong cold front pushed through the area overnight, temperatures dropped quickly. Regional Southwest Airport (RSW) in Fort Myers, FL, reported a temperature drop of 6 degrees and a dew point drop of 7 degrees between 4:00 a.m. E.S.T. and 5:00 a.m. E.S.T. Winds shifted, too. Light southerly breezes became briefly gusty northwesterly winds. There were also a few brief periods of heavy rain (Fig. 1).
At the Naples Municipal Airport (APF), about 30 miles to the south, temperature and dew point both tumbled 7 degrees in 35 minutes at around 5:00 a.m. E.S.T.
Both locations reported a barometric pressure rise of 0.05 inches of mercury, a fairly sharp short period pressure change.
Now that the initial cold front has arrived, people may be anticipating the usual one- to two-day chill down. That’s because winds typically swing around to easterly fairly quickly and milder Atlantic air arrives. In this case, however, a series of cold fronts during the upcoming week will ensure that winds remain mostly northerly and tat daytime highs are kept capped in the low to mid 70’s. Nighttime lows will fall into the 40’s at most locals, except look for a few upper 30’s in favored chillier interior locales. The daily average (also known as normal, although nothing in meteorology is ever “normal”) for this time of year is around 65 degrees. Hence, for the next week, we should remain below the seasonal average.
This will be a shock to our system because it has been such a warm January. In Naples, for example, there have been 18 degrees on which the mercury topped 80 degrees and 28 for which the daily average has been at or above the daily average. On only one day ((Jan. 18), did the daily temperature remain below average. On that day, the high temperature only reached 68 degrees.
On the minimum temperature side, there have been no days on which the overnight low dropped below 50 degrees.
The bottom line is that instead of being around 7 degrees warmer than average, we can expect temperatures for the next week to run slightly below average (three to five degree range).
When it comes to rainfall, south Florida has been dry (and should remain so). For the first 30 days of the month (not including this morning’s showers), only about a tenth of an inch of rain has fallen in Naples. Slightly more rain has fallen in Fort Myers. This translates into a deficiency of about 1.6 inches of rain since Jan. 1.
Not surprisingly, given the dry conditions, dry air mass, and expected gusty winds (in some places 20 miles per hour or more), red flag warnings (high wildfire danger risk) have been posted for much of the state of Florida for today (Fig. 2).
© 2013 H. Michael Mogil