Wake Low Wind Gusts in Florida Keys Wednesday
The NWS in Key West, Florida released a statement about a rare "Wake Low" that crossed the Keys earlier this week, which is quoted below. Here is a map showing wind gusts as the event passed through:
"A RARE WEATHER PHENOMENON KNOWN AS A WAKE LOW PRESSURE SYSTEM CREATED STRONG WINDS THROUGHOUT THE FLORIDA KEYS AND ADJACENT COASTAL WATERS DURING THE LATE AFTERNOON AND EVENING HOURS ON WEDNESDAY. A SQUALL LINE OF THUNDERSTORMS POSITIONED WELL AHEAD OF A COLD FRONT MOVED SOUTH AND SOUTHEAST OF THE LOWER KEYS DURING THE MID-AFTERNOON HOURS. SURFACE PRESSURES TO THE NORTH OF THIS SQUALL LINE BEGAN TO FLUCTUATE, AND RAPIDLY SINKING AIR ON THE FRINGE OF A RAIN SHIELD THAT TRAVERSED THE KEYS RESULTED IN STRONG WIND GUSTS."
The maximum wind gust was 59 mph at the Sombrero Key Light coastal (CMAN) station. You can clearly see the drop in pressure and rise in wind on the graph there, as the wake low passed over the station:
In this radar plot from 5 PM you can see that the storms have passed when the coastal station was gusting to 53 mph on its hourly observations:
Because the high winds with wake lows come after the storms (and often under clear skies), it can take boaters and coastal residents by surprise, especially if meteorological stations are few and far between (say, the eastern Gulf). They also tend to last for hours, not minutes like a normal thunderstorm or frontal passage (note the graph above showed high winds for two hourly observations!)
Because of these oddities, a wake low on Lake Michigan was featured in a lawsuit in 2008 that our Forensics Team worked on. Fortunately, there is some precedent for being able to predict wake lows with the high-resolution WRF computer forecast model. If you're interested in reading more, here's a list of wake low events that I was able to find on the Internet:
- Texas, 2011
- Wisconsin, 2011
- Georgia, 2011
- Mississippi, April 26, 2011 (Nice Illustration)
- Minnesota, 2010
- Texas, 2010
- Alabama, 2009
- Texas, 2007
- Texas, 2006
- Florida, 2004
- Wisconsin, 2002
- South Dakota, 2000
- Tennessee, 1995
