Flooded streets and damage to homes are being reported across Florida after Tropical Storm Colin made landfall overnight. (Reuters)

Late Monday night, the center of Tropical Storm Colin made landfall near Cedar Key, Fla. — about 90 miles north of Tampa, pushing ashore over four feet of water from the Gulf of Mexico. Then, as it crossed the Florida peninsula, it unloaded up to 11 inches of rain.

The storm will briefly drench coastal North Carolina on Tuesday before zipping out to sea.

As of Tuesday morning, Colin remains a very disorganized storm. In fact, it hardly resembles a tropical cyclone at all. In the infrared satellite image shown below, I marked the approximate location of the surface center of circulation with a white X — you would never know where it was otherwise!

Tropical Storm Colin at 8 a.m. Tuesday. (NASA)

Despite its lack of organization, it has produced impressive rainfall over the Southeast. Parts of central and northern Florida, including the Tampa Bay area, received 8-11 inches. Gainesville, Fla., which received 5.65 inches, had its 2nd wettest June day and 8th wettest day (of any month) on record, according to the Southeast Regional Climate Center. The map below shows the estimated rainfall totals from Sunday to Tuesday morning.

Two-day rainfall amounts. (NOAA)

Cedar Key, where the storm came ashore, had a surprisingly large (though well-forecast) storm surge from this sloppy cyclone. As the center of Colin passed just to the left of this location, it was positioned to receive the brunt of the surge of water. Some flooding of low lying coastal areas resulted.


The peak storm surge of 4.37 feet actually arrived at low tide (purple line in the chart below), but the surge was still large enough at high tide (green line) to produce the highest water level observed in Cedar Key since Alberto made landfall in June 2006 .

Water level data from Cedar Key, FL. The observed water level is the red curve, the predicted astronomical tide water level is the blue curve. (NOAA)
Water level data from Cedar Key, Fla. The observed water level is the red curve, the predicted astronomical tide water level is the blue curve. (NOAA)

(Note: The water depth values are relative to the Mean Higher-High Water level (MHHW), which is “the average of the higher high water height of each tidal day observed over the National Tidal Datum Epoch”.)

The chart above also displays the storm tide. Whereas storm surge is the depth of water added onto the normal astronomical tides by a storm’s onshore winds, storm tide adds the tide and surge together to give the practical observed water depth. A location will always experience worse flooding if a storm surge occurs during high tide.

Because a front is already forming on Colin’s south side —  a feature of non-tropical weather systems —  it will probably officially transition from a tropical to an extratropical cyclone today. But it could still bring tropical-storm-like conditions to parts of the North Carolina coast. The extratropical cyclone may actually end up being stronger than the tropical version ever was!

Position and forecast track as of Tuesday morning. Tropical storm warnings are marked with the purple line. (NOAA)

You can track Colin’s rainfall on this long radar loop I have produced: http://andrew.rsmas.miami.edu/bmcnoldy/tropics/colin16/Colin_5-6Jun16_southeast.gif