Weather

Texas A&M UniversityCOLLEGE STATION, Dec. 6, 2016 – With a major cold air mass expected to cover most of the U.S. this week – as much as 75 percent of the country could experience temperatures below freezing — it’s the time of year when the term “polar vortex” creeps into the news.  But it might be a good time to set the record straight on what exactly a polar vortex is, says a Texas A&M University weather expert.

John Nielsen-Gammon, Regents Professor of Atmospheric Sciences who also serves as the State Climatologist, says the term polar vortex has been around longer than you think.  It was first identified in the 1850s, and fully mapped out by the 1950s, but only in the last five years or so has the nomenclature made it to popular culture, perhaps in a misleading way.

Technically, he explains, a polar vortex is a large zone of very cold air that forms around the Arctic or Antarctic. There are actually two polar vortices – one at around 65,000 feet high, the other at about 25,000 feet high, called the tropospheric polar vortex and the one that most often affects the U.S.

The term itself has a “Star Wars” ring to it that evokes images of death stars and ray guns.  Instead, Nielsen-Gammon believes, it’s just an unfamiliar term for something very familiar.

“Most people already know that the jet stream carries storms from west to east, especially in the wintertime,” says Nielsen-Gammon.

“They might also have a sense that the jet stream is not just something over the United States — it circles the globe.  The tropospheric polar vortex is nothing more than this jet stream making a complete loop around the hemisphere, plus all the cold air inside the loop.”

So is the polar vortex the jet stream, or is it the cold air inside the jet stream?  “It’s both,” says Nielsen-Gammon.  “It’s sort of a chicken and egg thing.  Whenever you have deep cold air, you’ll have a jet stream along its edge, and whenever you have a jet stream, you’ll have cold air on one side.  You can’t have one part of the polar vortex without the other.

“In the Northern Hemisphere, whenever we’re north of the polar jet stream, we’re inside the polar vortex, and the weather is cold.  This happens a lot in the winter, as the vortex expands and waves in the jet stream occasionally cause the jet stream to swing even farther south.”

While waves like that are common, the coldest weather is usually underneath the very center of the polar vortex, he points out.  “Usually the center of the vortex is somewhere over the Arctic Ocean, or northern Canada, or Siberia.  On rare occasions, though, it can temporarily swing down over the northern United States,” Nielsen-Gammon says.

That’s what happened in the winter of 2013-2014, Nielsen-Gammon adds.  The center of the vortex made it all the way across the northern United States border, so cold air covered a large portion of the United States.

“This week will be different,” Nielsen-Gammon says.  “The problem this time is that the jet stream is unusually wavy.  Rather than forming a round vortex about the North Pole, it will look more like a squeezed water balloon, with one lobe extending into the northern United States and the other into Siberia.

“What’s noteworthy about this cold snap arriving in a few days is that it could be the coldest air of 2016 and set temperature records in many locations,” he adds.    “That’s because the traditionally cold months of last January and February were very mild across much of the country.”

Also, Nielsen-Gammon says, the cold air is arriving rather early in the season.  “I would not be surprised to see many record lows occur in the central United States this week.”

harris-county-flood-alerts

What is the danger?

A strong weather system entering the region starting Friday will deliver large amounts of rain across the area through Monday. The National Weather Service forecast indicates rainfall totals through the weekend could average 2-4 inches across Harris County with 8 or more inches possible in isolated locations .

The potential for street flooding will increase as rainfall totals may rise Sunday night-Monday morning. Floods are the leading cause of weather related deaths.

What you need to do:

Residents should monitor local media and the National Weather Service (NWS) for weather updates throughout the weekend. Various watches and warnings may be issued by NWS as conditions change.  Residents should follow all safety instructions in these messages.

In the event of street flooding, remember “Turn Around, Don’t Drown.” Driving through high water or around barricades on flooded roadways or underpasses can lead to death!

Know the NWS Flood Lingo!

  • Flood Watch: Be Prepared: A Flood Watch is issued when conditions are favorable for a specific hazardous weather event to occur. A Flood Watch is issued when conditions are favorable for flooding. It does not mean flooding will occur, but it is possible.
  • Flash Flood Warning: Take Action! A Flash Flood Warning is issued when a flash flood is imminent or occurring. If you are in a flood prone area move immediately to high ground. A flash flood is a sudden violent flood that can take from minutes to hours to develop. It is even possible to experience a flash flood in areas not immediately receiving rain.
  • Flood Warning: Take Action! A Flood Warning is issued when the hazardous weather event is imminent or already happening. A Flood Warning is issued when flooding is imminent or occurring.

Basic Flood Safety Tips

  • Turn Around, Don’t Drown! ® DO NOT DRIVE through high water and DO NOT DRIVE AROUND BARRICADES! Just 2 feet of water can sweep your vehicle away.
  • DO NOT WALK through flood waters. Just 6 inches of moving water can knock you down.
  • If your home floods, STAY THERE. You are safer at home than trying to navigate flooded streets on foot.
  • If floodwaters rise around your car but the water is NOT MOVING, abandon the car and move to higher ground. Do not leave the car and enter MOVING water.
  • STAY AWAY from streams, rivers, and creeks during heavy rainfall. These areas can flood quickly and with little warning.
  • MOVE important items – especially important documents like insurance policies – to the highest possible floor. This will help protect them from flood damage.
  • DISCONNECT electrical appliances and do not touch electrical equipment if you are wet or standing in water. You could be electrocuted.

Where you can learn more:

Forecasts: National Weather Service Houston-Galveston

Flood Safety: National Oceanic and Atmospheric Administration

Local Road Conditions: Houston TranStar

State Road Conditions: DriveTexas.org

forcasted-rainfall-totals 
www.readyharris.org
For more information visit the Regional Joint Information Center website at www.readyharris.org

Texas A&M UniversityWarm temperatures in Texas dominated the month of October, so much so that the month will go down as the fourth warmest October in the state’s history, according to figures from the State Climatologist at Texas A&M University.

John Nielsen-Gammon, Regents Professor of Atmospheric Sciences at Texas A&M who also serves as State Climatologist, says the month also tied for the sixth driest since official record keeping began in 1895.

“So far, we know that 215 records were set all across the state, from Alpine to Amarillo to Brownsville and Beaumont,” Nielsen-Gammon says.

“About 70 percent of those records were set during the period Oct. 16-20.  Every single station reported above-normal temperatures for the month.  The warmest areas relative to normal were the northern Panhandle, the Midland-Odessa area and the area northeast of Dallas.”

Numerous national records have also been set in much of the Southwest, Midwest and Northeast, with many stations recording October temperatures 20 degrees above normal.  Also, many northern cities have yet to record their first freeze, and areas such as Denver had no measureable snowfall in October.

Does it mean another warm winter is in store?

“October’s weather doesn’t mean much going forward, but the combination of a long-term warming trend and a likely La Niña (cooler than normal waters in the Central Pacific Ocean that tend to influence weather patterns) event does mean that winter is likely to be warm across Texas,” he added.

“We’re seeing drought spreading across much of the state, with core drought areas in East Texas and South Texas.  At this point, November is looking quite a bit wetter than October, but the overall outlook for the winter favors drier than normal conditions.”

 

Texas A&M UniversityStudying hurricane and tropical storm development from three million years ago might give today’s forecasters a good blueprint for 21st century storms, says a team of international researchers that includes a Texas A&M University atmospheric sciences professor.

Robert Korty, associate professor in the Department of Atmospheric Sciences at Texas A&M, along with colleagues from China, Norway, and the University of Wisconsin, have had their work published in the current issue of PNAS (Proceedings of the National Academy of Sciences).

The team studied storm development from the Pliocene era, roughly three million years ago, and chose that time period because it was the last time the Earth had as much carbon dioxide as it does now, and the changes in climate from it can play a major role in storm formation and intensity.

Using computer models and simulations, the team found an increase in the average intensity during the period and the storms most often moved into higher latitudes – to a more northward direction.

“There seems to be a limit on how strong these ancient storms might be, but the number getting close to the limit appears to be larger during warmer periods,” Korty explains.

“They reached their peak intensity at higher latitudes, following an expansion of tropical conditions with warming. It is consistent with smaller changes in the same patterns that we have observed over recent decades and project to continue over the next 100 years. I think it gives us greater confidence in some trends we are witnessing about how storms may change in future years.”

Researchers today know that the oceans continued to be relatively warm during the Pliocene era, though there has been some uncertainty where waters were warmest.  Their study found that the increase in average intensity and in the poleward expansion occurred regardless of where the greatest change in temperatures occurred in the Pliocene.

Korty says the study adds more evidence “that future storms are likely to be stronger in their intensity and to remain strong even as they move out of the tropics.”

The study was funded by the National Science Foundation.

 

Fort Bend CountyFORT BEND COUNTY, TX – Since the catastrophic flooding in May of this year, Fort Bend County has provided services to meet the needs of the thousands of residents impacted by the flood. From simple barricades across impassable streets, to rescue and evacuation, to temporary shelter and long-term recovery for the dozens of families actually flooded out of their homes; “business as usual” for Fort Bend County has been far from business as usual.

This past May, a large storm system moved through Texas, drenching the Brazos River watershed just upstream of Fort Bend County. The Brazos River rose to 54.8 feet at the Richmond river gauge, almost four feet higher than any event in the last sixty years. The flood inundated 17% of the county –148 square miles.

“This has been the biggest flooding disaster in the memories of most of our residents,” says Fort Bend County Judge, Robert Hebert, “and its impact is going to be felt in our community for a long time.” The resulting flooding damaged well over a thousand homes out of approximately 50,000 residents affected and forced the coordination of almost 800 rescues.

Many residents received flood insurance payments, FEMA grants, or Small Business Association loans, but that money only helps jump-start their recovery process. The County is now pursuing additional state and federal funds to help residents recover more fully, including funds to help offset costs of construction or sale of the affected property. This is, of course, in addition to the swift actions on the part of the County to ease the tax burden on affected homeowners, waive permitting fees for those who chose to rebuild and pay for contractor support to expedite the recovery process. For some, this will not be enough.

The County has also collaborated with the United Way to facilitate a Long Term Recovery Committee to help meet additional needs of the residents recovering from this disaster. The Long Term Recovery Committee (Fort Bend Recovers) is comprised of non-profits, faith-based organizations, community groups, businesses, and local governments working to find unique solutions for residents, like a furniture donation warehouse and a long-term recovery fund.

The County also opened a first-ever Flood Recovery Center. “We wanted to make it even easier for residents to get the help they needed to recover, so we moved several critical departments under one roof.” Judge Hebert adds, “In total 5 county departments staffed the center for 9 days and helped over a hundred residents get answers to their recovery questions.”

Fort Bend County has only begun traversing the long road to recovery, but with the County Judge, the County Commissioners, and the combined effort of county departments, progress is being made. The strong leadership and collaborative efforts of citizen volunteers, private businesses, non-profit organizations and local governments willing to come together in support those experiencing flood damage, reinforces why Fort Bend County is one of the best places in the United States to live, work and play.

Hurricane photoWhat is the situation?

Tropical Storm Nicole, the fourteenth named storm of 2016, has formed in the central Atlantic Ocean. There is no threat to Texas.

What you need to do:

Even though the 2016 Hurricane Season is winding down, residents of the Texas Gulf Coast should continue to be aware of the potential for tropical weather. Whether you are in an evacuation zone or you just need to be able to ride out the storm, the Harris County Office of Homeland Security & Emergency Management (HCOHSEM) has resources to help you be ready for anything at www.readyharris.org.

HCOHSEM’s ReadyHarris mobile app puts the power to build a personalized preparedness plan in the palm of your hand. The free app is available for both Apple and Android. Click here to download now.

Where you can learn more:

National Hurricane Center
Interactive Zip-Zone Evacuation Map
Houston-Galveston National Weather Service Office
Ready.gov – Hurricanes

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Hurricane photoWhat is the situation?

Tropical Storm Matthew has formed near the Caribbean. It is the 13th named storm of 2016.

What you need to know:

Tropical Storm Matthew poses no threat to Texas.

Keep in mind that there is still a good chance for tropical storms or hurricanes to form late in the season. The Harris County Office of Homeland Security & Emergency Management reminds residents to remain vigilant. Prepare now by having an emergency plan, assembling an emergency supply kit and by staying informed. Go to www.readyharris.org for resources or download our free ReadyHarris mobile app to help you create a personalized preparedness plan. Click here to download it now. Hurricane season runs through November 30th.

Where you can learn more:

Tropical Weather Information: National Hurricane Center

Local Forecast: National Weather Service

Preparedness & Emergency Information: www.readyharris.org
www.readyharris.org
For more information visit the Regional Joint Information Center website at www.readyharris.org

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harris county alertsSeptember 20, 2016

What is the situation?

Tropical Storm Lisa has formed in the Atlantic. It is the 12th named storm of 2016.

What you need to know:

Tropical Storm Lisa poses no threat to Texas.

According to the National Hurricane Center, the Atlantic basin is experiencing its most active season in three years. The Harris County Office of Homeland Security & Emergency Management reminds residents to remain vigilant. Prepare now by having an emergency plan, assembling an emergency supply kit and by staying informed. Go to www.readyharris.org for resources or download our free ReadyHarris mobile app to help you create a personalized preparedness plan. Click here to download it now. Hurricane season runs through November 30th.

Where you can learn more:

Tropical Weather Information: National Hurricane Center

Local Forecast: National Weather Service

Preparedness & Emergency Information: www.readyharris.org
www.readyharris.org
For more information visit the Regional Joint Information Center website at www.readyharris.org

September 14, 2016Hurricane photo

What is the situation?

Tropical Storm Julia formed in the northeast Atlantic on Tuesday evening. It is the tenth named storm of 2016.

What you need to know:

Tropical Storm Julia made landfall early Wednesday morning and poses no threat to Texas.

We are now at the peak of hurricane season and the Harris County Office of Homeland Security & Emergency Management reminds residents to remain vigilant. Prepare now by having an emergency plan, assembling an emergency supply kit and by staying informed. Go to www.readyharris.org for resources or download our free ReadyHarris mobile app to help you create a personalized preparedness plan. Click here to download it now. Hurricane season runs through November 30th.

Where you can learn more:

Tropical Weather Information: National Hurricane Center

Local Forecast: National Weather Service

Preparedness & Emergency Information: www.readyharris.org
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For more information visit the Regional Joint Information Center website at www.readyharris.org

Hurricane photoWhat is the situation?

Tropical Storm Hermine has formed in the Gulf of Mexico and is forecast to make landfall along the Florida Gulf coast by Thursday evening. Hermine is the eighth named storm of 2016.

What you need to know:

Tropical Storm Hermine poses no threat to Southeast Texas.

Any tropical system in the Gulf of Mexico can be a potential threat to the Texas coast during hurricane season. Make sure your emergency kit and disaster plans are up to date. Make sure everyone in your family knows what to do in the event you have to evacuate or shelter in place due to tropical weather.

Go to www.readyharris.org for additional resources and download our free ReadyHarris mobile app to help you create a personalized preparedness plan. Click here to download it now.

Where you can learn more:

National Hurricane Center
Interactive Zip-Zone Evacuation Map
Houston-Galveston National Weather Service
Ready.gov – Hurricanes
www.readyharris.org

For more information visit the Regional Joint Information Center website at www.readyharris.org