Saturday, August 29, 2015

Hurricane Katrina: 10 Years Later

Hurricane Katrina made landfall ten years ago today. Nobody knew at the time, but she turned out to be the costliest natural disaster in the history of the United States. She caused over $1 billion in damage across the southeastern U.S. Not only that...she was also ranked in the top five for fatalities as 1,836 people lost their lives as she marched through Louisiana, Mississippi, and Tennessee before becoming weak enough to not be considered a tropical system.

Katrina was fascinating for a couple of reasons. First, she developed initially in the middle of the Bahamas as a weak tropical storm with winds of 40mph. She then moved northwest like most systems do in that area, but do to other meteorological factors, she took a dive southwest and made landfall in South Florida near Miami and Ft. Lauderdale as a category one storm.

There was some significant flooding with this portion of Katrina's track, but nobody knew what would eventually come down the road.

The system weakened to a tropical storm again before making its way back out over the warm open waters of the Gulf of Mexico. This is where the second fascinating part of Katrina's story took place. She was essentially stationary for a long duration of time west of Key West, Florida. She was able to remain stationary because of a high pressure system in the upper levels of the atmosphere, as well as no directional winds being present to push her along. For this reason, she was allowed to sit and gain strength at a rapid pace.

During this rapid intensification, Katrina became a monstrous category five storm with winds upwards of 175mph. Hey eyewall was textbook, and the structure was absolutely perfect. This is not what the Gulf Coast wanted to hear as Katrina took a turn to north after her intensification period.

Areas from the Panhandle of Florida to Texas were becoming increasingly worried and concerned about Katrina and her eventual path of destruction. It was essentially inevitable that somewhere from Florida to Texas there would complete and utter devastation--this ended up being true for those in Louisiana and Mississippi especially.

Katrina did weaken slightly to a category three storm before making landfall along the Louisiana-Mississippi border, but that did not mean anything regarding the destruction she would bring. The levees failed in New Orleans, eventually causing roughly 80% of the city to flood. For the first time, a mandatory evacuation was ordered for New Orleans. The Superdome was the place to go if you could not exit the city. And, even that highly sturdy structure suffered considerable damage.

Storm surge of anywhere from ten to twenty-eight feet occurred along the coast, pushing water inland and causing catastrophic flooding well away from the coast. Katrina was so powerful and well-organized that she remained a named tropical system all the way until nearly the Tennessee-Kentucky border. Most tropical systems don't make it that far inland while still maintaining tropical storm characteristics. Katrina was different.

Looking back, we all know how powerful and dangerous Katrina was. We all know what she caused. We all know that it was a storm to never be forgotten.

The next question is: when will it happen again?

Friday, August 28, 2015

Erika Update...

Tropical Storm Erika is currently situated along the border of Haiti and the Dominican Republic slightly off the coast to the south of these countries. She is moving west-northwest at 21mph currently. Her peak sustained winds are around 45mph, making her a weak tropical storm.

The reasoning behind her struggle to strengthen is due to unfavorable wind conditions in and around the storm. Wind shear is hostile to tropical systems, and there is plenty of shear in place in the environment where Erika is currently located.

Here is a map providing a visual of where Erika is currently located and why she is not able to maintain her strength and organization. However, she is expected to move northwest and into the warm and supportive waters between the Florida Keys and Cuba. Once she moves off of Cuba by Sunday, she is expected to gain strength and evolve into a weak hurricane before eventually making landfall on the western coast of Central Florida.

However, despite the current track forecast, it appears as though she wants to continue moving westward before turning north. For that reason, the current forecast track will likely be moved slightly westward. This means Florida landfall may not happen, and if it does, it would be in the Panhandle.

Regardless, expect landfall somewhere in the Gulf of Mexico in all likelihood. Erika's strength will likely be a weak hurricane, so this storm is definitely something to monitor. We will provide updates as she evolves over the next few days.

Friday Night Football Forecast

If you're heading out for Friday night football you'll want to grab an umbrella or poncho, because showers will be moving into the area for the afternoon and evening.

Looking to the west, an area of low pressure is moving ENE across Iowa and will be moving into portions of northern Illinois and southern Wisconsin through the afternoon. Rain will move in earlier to the west and move east through the day. The thunderstorm threat for the day is fairly low because there isn't much instability across the area, which is a key ingredient for thunderstorms. But, hearing a rumble or two in the evening is a possibility. We look to be able to get most high school football games in before we see an increased threat for more thunder overnight, but again the instability is fairly limited, so the chance is small.

Rain fall amounts look to add up to 3 inches in areas to the west of the Stateline, while around here we can expect 3/4 to an inch of rain through Saturday morning. These amounts can shift a bit through the day however, and will be closely tied to the area of low pressure. As the low pressure and cold front move through tomorrow morning we hold on to the chance for scattered showers as well as patchy fog through about 1pm. Highs on Saturday will only warm into the mid 70's, but the 80's return on Sunday will decreasing clouds.

Thursday, August 27, 2015

Active year for tornadoes

The National Weather Service in Chicago covers the following counties:  Boone, Cook, DeKalb, DuPage, Ford, Grundy, Iroquois, Kane, Kankakee, Kendall, Lake, La Salle, Lee, Livingston, McHenry, Ogle, Will and Winnebago.

As of August 27th, 2015, a record number of tornadoes have occurred within the warning area of the Chicago National Weather Service.  According to the weather service, the four tornadoes that occurred on August 18th, 2015 brought the yearly total up to 29.  This breaks the old yearly record for tornadoes in their warning area of 27, set back in 2004. 

With the advancement of Doppler radar in 1992, dual polarization in 2012, and the development of the spotter network in northern Illinois, the ability to not only detect, but to actually visually confirm smaller tornadoes that may have otherwise gone unnoticed has increased.  It's also interesting to see the past two years, 2014 and 2013, also within the top ten. 

Wednesday, August 26, 2015

Friday Night Football rain?

It's possible.  Skies have been fairly dry since the record breaking rainfall early last week.  Since then, we've been dealing with a little more fall-like weather.  This trend will continue for the rest of the week, but each day temperatures will continue to warm.

Low pressure spinning in the southwest will ride overtop a ridge of high pressure in the center of the United States.  Thunderstorms are likely from the Plains to Iowa and Minnesota by Thursday afternoon and evening, with heavy rain falling from Iowa into Wisconsin by Saturday night.

For us, low pressure will track right overhead giving us the chance for a few showers and thunderstorms, but it doesn't look like a complete washout.  Thunderstorms are in the forecast for Friday night, but the majority of the rain could very well hold off until after 8pm.

Low pressure lingers through Saturday, so we'll hold on to the cloud cover with a few scattered showers into the afternoon.  Rainfall amounts could add up to half an inch in some of the heavier showers.  After that, skies look dry until the end of next week.

Topical Storm Erika Looks to Grow

Tropical Storm Erika looks to reach hurricane status early next week, and its potential path brings it into portions of Florida.

Currently Erika is located about 285 miles to the ESE of Antigua with maximum sustained winds at 45mph. Erika is moving to the west at 17mph but looks to take a more WNW turn in the next two days.

A Tropical Storm Warning is in effect for St. Martin, Antigua, Barbuda, and the U.S Virgin Islands, along with others.  Erika looks to reach the Leeward Islands tonight and then the Virgin Islands and Puerto Rico on Thursday. Total rainfall amounts look to be around 3-5 inches of rain, with max amounts near 8 inches across the Leeward Islands, the Virgin Islands, and Puerto Rico through Friday morning.

For more information click here

Tuesday, August 25, 2015

Not a cooler weather fan? Just wait, warmth is on the way

August will likely wrap up slightly below the monthly average of 82 degrees.  The extra push will come from this week's temperatures remaining nearly ten degrees below average.  But, if you're not a fan of the cooler weather - don't worry.  As we flip the calendar over to September, temperatures could be running in the other direction.

We'll likely see temperatures rise into the middle and upper 80's for the first week of September, with some models indicating a return of the 90's.  Sometimes forecast models tend to warm temperatures too far, too quickly.  But this warm up is something that's been advertised for some time now.  So, it's a good bet we'll see a return of the summer warmth.  It's just a matter of how long it will last.