The Tropics; Bonnie On A Two Ocean Cruise; Colin Pulls A Surprise

Tropical Storm Bonnie emerging into the 
Pacific Ocean after crossing Nicaragua from
the Atlantic Ocean on Saturday.

 As we start July, the tropics tend to get a little more active as we ramp up toward the heart of hurricane season in a month or two.

That Wannabe Tropical Storm Bonnie finally got its act together and became official Tropical Storm Bonnie on Friday. It smacked into Nicaragua last night and is dumping heavy rain there. Flooding and mudslides are likely causing big trouble there as I write this. 

Bonnie then did something odd.    Normally, when tropical storms and hurricanes hit Central America or Mexico from the Caribbean Sea, they quickly get torn apart and die over steep mountains. You might get some remnant energy that makes it to the Pacific, and on a few occasions, that might develop into a new Pacific tropical storm.

The western Pacific has different names every year for tropical storms and hurricanes than the Atlantic Ocean. So if remnant energy from a former Atlantic tropical storm gives birth to a new tropical storm in the Pacific, it gets a new name.   

Bonnie is a rare rule breaker.  Bonnie threaded  the needle between mountain ranges as it moved through Nicaragua. It crossed a narrow part of central America that includes large Lake Nicaragua. So it didn't get weaker as fast as it normally would.

Late Saturday morning, Bonnie emerged over the Pacific Ocean as an intact tropical storm.   To remove confusion, Bonnie will keep her name as it moves northwestward.

This is the first tropical storm to pull this Atlantic to Pacific stunt since Otto in 2016. Had Bonnie fallen apart completely, but the storm's left over energy or upper level circulation made it into the Pacific Ocean, it would have been re-named Darby. 

Weak Tropical Storm Colin formed unexpectedly
last night along the South Carolina coast. 

In any event, Bonnie is forecast to move northwestward, staying south and west of Mexico. It could become a hurricane once it's well offshore. 

Meanwhile, Tropical Storm Colin was a surprise storm that formed along the coast of South Carolina last night. 

I noticed a suspicious looking swirl of clouds and rain moving off the Georgia coast yesterday. Few expected this swirl to blow up into a tropical storm, especially since atmospheric conditions were not great for development and the center of this little storm was hugging the coast.

But form it did! Still, Colin is not expected to amount to much. Northwesterly winds aloft are pushing the roughest weather with Colin offshore. The fact that Colin is still hugging the coast and those northwesterly high level winds will persist, this thing won't strengthen much more, if at all.

Colin is breaking rules in another way. In much of coastal South Carolina today, Colin was pulling in dry air from the northwest. Because of this, despite the proximity of Colin, it's been a pretty nice beach day for the coast of South Carolina. Not what you'd expect with a tropical storm lurking around you. 

Finally, a cold front heading southward should blow apart what remains of Colin around Monday.