The official start to the 2014 Atlantic Hurricane season starts this Sunday, June 1st. This is National Hurricane Preparedness week, which makes it the perfect time to understand the risks of tropical storms and hurricanes and devise a plan should you and your family get caught in this type of threatening weather.
The major hazards associated with hurricanes are storm surge and storm tide, heavy rainfall and inland flooding, high winds, rip currents, and even tornadoes. The images below give a good visual of the storm tide and storm tide and flooding hazards associated with tropical storms and hurricanes. Always remember when it comes to flooding: Turn around, don't drown.
With improving satellite and radar technology, combined with more advanced and powerful numerical weather models, meteorologists can warn the public of potential tropical storms days and sometimes a week in advance.
Even with advanced warning, you don't want to be scrambling at the last minute to fill your emergency hurricane kit and devise an evacuation plan. Do it now. In fact, Virginia residents can purchase items such as batteries, flashlights, first aid kits, bottled water, NOAA weather radios, etc. tax free through Saturday.
The AQI is a daily report that gives the quality of the air across the region. This index becomes increasing more important in the summer months when our air quality is more at risk for being unhealthy.
A color coded chart was designed to more easily inform the public about the anticipated air quality level, what impacts it may have on health and what actions you can do to help reduce the pollution levels!
AQI Action Guide
For example, today is forecast to be a Code Orange Day, which means the air is unhealthy for sensitive groups of people. According to the professionals at Clean Air Partners, “children and adults with respiratory and heart ailments, may experience health effects and should limit time spent outside. The general public is not likely to be affected.”
But throughout the course of the summer we will likely have some Code Red days as well and those days impact all of us. But what exactly causes the pollution? My Storm Watch 7 colleague and friend Ryan Miller who also happens to teaches Environmental Science at Washington and Lee High School does a great job explaining the ins and outs of air quality!
Poor air quality days occur because of the emission of certain chemical compounds into the atmosphere that often times react with light from the sun to produce pollutants.
The emission of these chemical compounds, primarily through the burning of fossil fuels for electricity production (coal) and for transportation (gasoline and diesel) couple with other pollutants to give us bad air to breathe.
The two most prevalent pollutants that give us poor air quality in the D.C region are ground-level ozone and incredibly tiny particles of materials like dust and carbon (among other things).
The reason for more poor air quality days in the summer has to do with several factors:
1. Ground-level ozone, the bad ozone, forms when our power plants and cars emit a chemical compounds called nitrogen oxides and volatile organic compounds that react with sunlight to produce this form of unhealthy ozone. We use more electricity right now to power more air conditioning systems, that allow for more emissions of these aforementioned chemicals into the atmosphere, that increases ground-level ozone concentrations and degrades the air.
2. Our summer months have days that are filled with much more light from the sun and it is this sunlight that works in tandem with the chemical compounds we emit from fossil fuel use (again electricity production and transportation) to create more atmospheric pollutants than at any other time of the year.
3. From a weather standpoint in the summer much of the North American continent is heated up in an almost semi-uniform manner and thus we often do not get very strong frontal systems (like cold fronts) to pass by and deliver big changes in air. These frontal systems are often accompanied by strong winds, think of the winds our region gets in the fall, winter, and spring, and because of the lack of strong winds over a large geographic area during the summer months the air in our atmosphere can stick around for days and become stagnant. We keep emitting pollutants into our atmosphere in the summertime and without strong winds to move these pollutants away from our region they accumulate more and more into the air we breathe and degrade the air quality.
A cautionary note about exercising outside during poor air quality days.
Out of our two primary pollutants that cause bad air quality, ground-level ozone and particle matter, its ground-level ozone that accumulates and can be very detrimental to our health. Remember, it takes sunlight to make ground-level ozone, and we are getting sunlight all day long that works to form this harmful air pollutant, so it is the afternoon and evening that has the largest amount of ground-level ozone present in the atmosphere (with the highest concentrations).
Exercising in the evening will expose you to more harmful pollution that at most other times of the day. Don't do it. Exercise in the morning or inside at a gym on these poor air quality days.
Heading to the beach this weekend? It should be a big improvement to last weekend with plenty of sunshine and warmer temperatures. Highs should reach the lower 80s on Saturday and around the 80 degree mark on Sunday for the southern Jersey beaches, Eastern Shore and Outer Banks. Virginia Beach is expected to be a little warmer in the mid 80s each day.
Remember, the water temperatures are still in the mid 60s for the northern beaches, mid 60s closer to Virginia Beach and in the lower 70s in the Outer Banks. There's still a bit of a chill in the water so remember that before going to take a "refreshing" dip. Winds will be a bit on the breezy side at times out of the southwest around 10 to 15 mph. Skies should be sunny each day. Enjoy!
After a cool and comfortable spring, it's back to reality as a stretch of 90 degree heat is upon us. Reagan National Airport (DCA) already hit 90° once back in April, but we haven't had long stretch of heat since last summer (late July/early Aug.) when there were 10 consecutive 90° days. Well, say hello to our first heat wave of 2013. It'll only last through Saturday, but you'll still notice it.
The average high temperature, record highs and going forecast are shown below. Clearly our temperatures are well above average but likely not within reach of records. As a rule of thumb this time of year, the mercury needs to climb into the upper 90s to tie or break a record at DCA.
"(Also called hot wave, warm wave.) A period of abnormally and uncomfortably hot and usually humid weather."
"To be a heat wave such a period should last at least one day, but conventionally it lasts from several days to several weeks. In 1900, A. T. Burrows more rigidly defined a "hot wave" as a spell of three or more days on each of which the maximum shade temperature reaches or exceeds 90°F. More realistically, the comfort criteria for any one region are dependent upon the normal conditions of that region. In the eastern United States, heat waves generally build up with southerly winds on the western flank of an anticyclone centered over the southeastern states, the air being warmed by passage over a land surface heated by the sun. See also hot wind."
After weeks of cool weather, summer is coming on full force with a heat wave that will hit D.C. starting Wednesday and continuing through Saturday.
We reached 90 degrees or better only once so far in 2013 with a high of 91 on April 10. Since then, it seems the heat and humidity has been elusive, but for those of you ready for the pool, it will be "pool worthy" the rest of the week.
A warm front will lift north of us through the day today and allow much warmer air to push into the Mid-Atlantic. This will also trigger some showers and thunderstorms.
Tuesday Afternoon Forecast
By Wednesday, the sunshine and southerly winds will bring temperatures into the upper 80s to near 90 degrees. The jet stream stays north and keeps us in the bubble of warm air through Saturday.
Jet Stream Forecast
The average high in D.C. for this time of year is 79 degrees. However, while we will see above average temperatures the rest of the week, it won't quite be recording breaking.
The record high on Wednesday is 97 degrees. On Thursday, the record high is 98 and on Friday, the record is 99. That also happens to be the hottest temperature ever recorded in the month of May in Washington, D.C., which was recorded in 1991.
Take it easy in the heat by dressing in light weight, loose fitting clothing. Drink plenty of water. And get those runs and bike rides done in the morning or in the evening. Avoid strenuous activities between 2 and 6 p.m.
The Memorial Day holiday weekend will be a sunny but chilly one in the Washington area but don’t let that fool you. There is a hidden danger to be aware of on sunny, cool summer days.
High pressure will bring plenty of sunshine to the Washington area and points south this extended holiday weekend. Even though temperatures will be well-below average in the 60s and 70s with gusty winds at times through the first half of the weekend, the sun angle is very high this time of the year. As a matter of fact, the weather will be so chilly and brisk across the region, it’ll be very easy to forget packing the sunblock but don’t!
The UV Index is forecast to increase this weekend to 7 to 8 across the Mid-Atlantic and get as high as 9 to 13 across the Southeast.
What do these numbers mean? A UV index from 7 and above means you can burn in 20 minutes or less (especially if you are fair skinned). An SPF sunscreen of 30 is highly recommended. The sun's rays are strongest between 10 am to 4 pm.
The worst combination is a wind burn (because northwest winds will be rather brisk this weekend in the Washington area) and a sunburn, so be careful when outside this holiday weekend!
For more on the consequences of sun exposure, click here. Have a safe and enjoyable weekend!
It's time to start heading to the beaches again! I hope everyone has lined up their list of back roads for the Eastern Shore or is planning to leave at Midnight to avoid the 5 hour trip time. Regardless, it's the beach, it's worth it. Will the weather cooperate though? Here's a look at the Memorial Day Weekend forecast on the Eastern Shore.
Temperatures: Mid 60s Winds: NW 10-20 Gusts to 35 m.p.h.
Another day forward in the forecast and conditions seemed to have improved as far as rain and clouds but still poor as far as temperatures and winds. I don't think this will be a beach day with wind gusts to 35 mph and sustained winds around 10 to 20 mph. This could lead to blowing sand, rough surf and plenty of that beautiful sea foam! Temperatures will only reach the mid 60s making it feel even cooler, so have a sweatshirt handy. More sunshine should filter into the region as the day goes on.
Low pressure will be moving farther off the east coast into the Atlantic, making for improvements along the Eastern Shore. Temperatures will still be cool unfortunately, with highs only in the mid to upper 60s. This will be the case as water temperatures, which have a huge impact on the air temperatures, are only in the mid 60s.
At this point I think Monday will be the best day of the bunch, with plenty of sunshine and slightly milder temperatures. Highs should reach the upper 60s under partly cloudy skies. Clouds look like they will be the upper-level cirrus variety so I would imagine there would be a filtered sunshine. Winds will be light around 5 to 10 mph out of the northwest.
After such a memorable hurricane season last year which featured Hurricane Sandy, many of us will be taking note of the National Hurricane Center's Atlantic hurricane season outlook which they issued today. Here is a quick look at the number of named storms, hurricanes and major hurricanes (Category 3 or higher) they expect this season.
"For the six-month hurricane season, which begins June 1, NOAA's Atlantic Hurricane Season Outlook says there is a 70 percent likelihood of 13 to 20 named storms (winds of 39 mph or higher), of which 7 to 11 could become hurricanes (winds of 74 mph or higher), including 3 to 6 major hurricanes (Category 3, 4 or 5; winds of 111 mph or higher).
These ranges are well above the seasonal average of 12 named storms, 6 hurricanes and 3 major hurricanes."
Reasons for the above-average activity are warmer than average sea-surface temperatures in the tropical Atlantic, near-normal sea surface temperatures in the equatorial Pacific, and the continuation of the overall atmospheric climate pattern responsible for the high activity era since 1995.
How does this compare to last season? Here was the National Hurricane Center's 2012 season recap.
"For the 2012 Atlantic season, 19 named storms formed, of which 10
became hurricanes. One of those hurricanes, Michael, reached major hurricane status. Activity fore 2012 was well above the 30-year (1981-2010) average for named storms and hurricanes, and below average for major hurricanes. The 1981-2010 seasonal averages for the Atlantic Basin are 12 named storms, 6 hurricanes and 3 major hurricanes."
This has been a journey (not over yet by the way) that began when I was a young kid who always loved the sky and the weather. I never dreamed I would be a broadcast meteorologist for some 45 years.
Like so many of us who love what we do, have done, and have yet to do, teachers were critical to where I find myself today. Science and math were my favorite subjects in school and my general science teacher really encouraged me. I was the only kid in the 9th grade who really loved the weather. I did get 100 on the general science section on the atmosphere. But he also was a great adviser for my science fair projects.
Here I am with one of favorite projects, my homemade Van de Graff generator. Must be some distant relative of NewsChannel 8 meteorologist Brian.
I was still the local paperboy in the town where I grew up and was out in all sorts of weather and loving it. I still don't like terrible tornadoes such as just hit Moore, Okla. or ice storms. I wanted to be a weatherman - a meteorologist. But in the 1950s, most of the jobs were working as forecasters for the U.S. Weather Bureau. That meant "shift work." I might have to work midnight-4 AM sometimes.
I was never keen on getting up early and the idea of shift work (still not a good idea for my many friends in the NWS who get burned out after 30+ years and we lose great meteorologists to retirement) was not appealing. About the same time, I saw the first earth satellite, Sputnick in the night sky. That was really exciting. I was going to build rockets.
Here I am with my other science fair project with model rockets.
But after a number of years at college and studying physics, I still loved the weather and was lucky enough to meet another wonderful teacher who became my mentor and lifelong friend.
Dr. Bernard Vonnegut (yes Kurt's brother) here with other teachers from SUNY Albany from the right Duncan Blanchard, Bernie, Vincent Schaefer and Ray Falconer.
Here I am conducting an experiment for Bernie.
We were forming small whirlwinds from the heating from an electrical discharge. I did not electrocute myself but did come close. Ray suggested I look up the great weathercaster Don Kent as I began a career in research in Boston. I was fortunate to get a moonlighting job at one of the first 10 PM newscast in Boston (the news was canceled after 9 months). Thanks to encouragement from legends such as Don and my colleague Bob Copeland, I was soon on my way from a research lab to broadcast meteorology.
Would you hire this guy today wearing a horse blanket for a sport jacket? Actually that was the style and my wife has picked out what I wear every day for 35+ years. Even getting up with me at 2:30 AM when I was doing the Today Show from 1978 to 80.
Then I spent 30 years at NBC4 with terrific coworkers and friends like Vance and Doreen and many years of writing my Almanac.
The proceeds of the Almanac go to children's charities. Of course, there is also the Golden Snow Shovel contest and the first digital weather site in Washington with friends Dave Jones and Mark Hokezma.
With sponsors, we placed 300 interactive weather stations in area schools (now our WeatherBug network here).
And the, there is the last three years here with the wonderful team at ABC7. Our digital weather page with Doug and the entire team keep you up to date 24/7.
Helping a great team of designers and digital gurus has been just fun for a kid who never even saw a television until he was almost 10 years old. I still love the weather and how we communicate weather. I still think we need to "complete the forecast" and really involve social scientists into our physical scientists. A perfect forecast but not the best decsion is still not the best forecast.
There will be more fun things to do in my science when I step down from TV. But I will have more time with my life long partner and best critic, Olga and more time with Santa like this.
These are the reasons I'm now taking a break and can't wait to just watch that first snows in the seasons ahead and enjoy watching as I did 65 years ago as I have done forecasting for 40 years.
Enjoy the weather and enjoy everyday. I'll see be around Washington and sure see you from time to time. Just smile and ask, "how's the weather?" I'll smile and say "It's great."
With advancements in radar technology, forecasters have a greater ability to analyze storm structures. Even though there is still much more to be researched and explored, meteorologists can get a good indication of the height, size, and intensity of a particular storm cell, which then leads to better warnings to the public. The 3D visuals in the video below recap the evolution of the devastating tornado in Moore, OK Monday.
The Moore, OK tornado, at one point, reached the highest tornado classification, EF5 status. EF4 and EF5 tornadoes make up only 1% of all the tornadoes in the U.S.
I wanted to share this first and foremost. You can donate to the Red Cross primarily but if you search around, some businesses will even match your donation. One of those is the National Storm Shelters LLC who tweeted earlier that they will match donations sent through their Red Cross Page Here.
The Red Cross stands ready to help meet the blood needs of patients in and around Oklahoma City if needed, and there is currently enough blood on the shelves to meet patient demands. The Red Cross is a secondary supplier of blood products to hospitals in the affected area in Oklahoma. People with type O negative blood are encouraged to give blood when they are able. All eligible blood donors can schedule an appointment to give in the days and weeks ahead by calling 1-800-RED CROSS or visiting www.redcrossblood.org to help ensure blood is available when people need it.
Here is a look at the track of the tornado. It first touched down at 2:56pm and finally roped out at 3:36pm with a path length of 17 miles and a preliminary damage rating at EF-4 intensity.
The National Weather Service office in Norman, OK is continuing to do the damage survey today and will probably continue working on it tomorrow before putting out the final assesment. They will continue to keep updating their page on the tornado here.
You can also stay up to date with the NWS Norman Public Information Statement found here. The latest statement continues to show EF-4 damage with estimated winds of 190 mph, though they said they will continue to update as the teams complete their surveys.
Right after I write that, this was put out by the NWS Norman twitter page, "@NWSNorman: At least one area of EF-5 damage was found by survey crews. Details to follow later. #okwx", so updates will be made soon.
This is a bit of a tough post to make after watching everything yesterday leading up to the tornado and then watching the tornado itself form just southwest of Oklahoma City.
By the time the storm reached Moore, Okla., the storm was an absolute monster. The tornado was up to a mile wide and the winds were possibly up to 200 mph, according to preliminary reports from the National Weather Service.
Unfortunately this storm has taken 24 lives so far (at least not the 91 reported by some outlets earlier today) and just looking at the damage I would imagine there still may be more found today.
Similar tracks of the 1999 and 2013 Moore Tornadoes
Here is a look at the path of this tornado compared to the one that struck the same area on May 3, 1999, which was also classified as a F-5 (Before the EF scale was used) and had winds recorded at nearly 300 mph from a nearby Doppler on Wheels.
It's crazy how these two storms paralleled one another before crossing paths with nearly the same strength 14 years apart.
Comparison of the 1999, 2003 and 2013 Tornado Tracks (Credit: Weather Decision Technologies)
Another view of the track compared to the 1999 tornado as well as the 2003 F-4 tornado shows just how violent tornadoes have been in that area over the past 14 years.
Reflectivity image as the tornado moved into Moore. Note the giant debris ball which is the pink circle entering Moore.
Above is what I was looking at as this storm was at its height. This is the reflectivity image from the Oklahoma City radar located just southeast of the storm.
If you take a look at the image you will note the big pink to purple circle on the radar image heading into Moore. When I saw this, I was terrified, because that is actually debris suspended in the air that the Doppler is seeing. You can clearly see the classic "hook echo" to the storm, but it's that debris signature that gives you an idea of just how strong this thing was.
Velocity image from the ktlx Doppler radar east of Moore
Above is a look at the velocity image, which shows winds going towards the radar in green and blue and winds going away from the radar in red. This is definitely one of the strongest velocity couplets I've seen through my radarscope app. This is showing winds in excess of 150 mph and possibly up to 200 mph which would be in an EF-4 range.
It's just unbelievable strength and power in this storm, and something that you most likely will not make it through unless you are underground or in a storm shelter.
Here are a few videos I've seen from YouTube of the tornado.
The storm threat isn't done yet. There is still a moderate risk for severe storms today stretching through Texas, Louisiana and Arkansas and a slight risk through much of the Midwest. Be sure to heed warnings and be ready for severe weather again this afternoon.
May might have started out slow, but tornado season is now in high gear. A major outbreak over the weekend left dozens homeless and killed at least one person.
Hardest hit was Shawnee, Okla., where a large, violent tornado struck a mobile home park leaving nothing standing. Here is video from our ABC affiliate of the damage. That twister, among several others, was caught on tape by stormchasers.
The severe weather had been advertised for days. All of the elements came together like a textbook example of how warm moist air from the Gulf of Mexico meets up with cooler, drier air from the north. Strong winds turn with height in the atmosphere and the winds also increase in speed with height.
This helps provide the support needed for major tornadoes of EF3 or more.
Severe Weather Elements, Accuweather
The Shawnee tornado is yet to be rated on the Enhanced Fujita Scale, but the National Weather Service is on the scene Monday to do a survey. In all, there were around 50 preliminary reports of tornadoes this weekend and many, many more reports of wind damage and hail stretching from Oklahoma to Minnesota. Here are the storm reports from just Sunday:
Storm Reports Sunday, May 19, 2013
Unfortunately, more tornadoes are expected this afternoon and evening. The Storm Prediction Center has issued a "Moderate Risk" for tornadoes in some of the same areas of Oklahoma. A slight risk stretches into the Great Lakes.
Severe Weather Outlook Monday
Despite the large number of tornadoes this weekend, we are still far below the seasonal averages. May is usually the month with the highest count of tornadoes in the United States. Check out this graphic from the Storm Prediction Center. Also, notice the high count in 2011.
Preliminary 2013 Tornado Count
As for us in D.C. Maryland, and Virginia, we tend to see more frequent violent weather in July and August, but tornadoes can and do happen in May and June. Remember, it's not the number of tornadoes that develop, it's the potential of just one of them impacting you.
I recently attended a talk by Dr. Michael Mann, a leading climate scientist who also has drawn more than his share of biased criticism and even very harsh personal attacks for his work.
His recent book, The Hockey Stick and the Climate Wars, relates his work on reconstructing the climate back thousands of years, but as the title insinuates, how his findings have lead to political, philosophical and personal attack. Climate is always changing as shown in this reconstruction back millions of years.
But the key question remains: "Is human activity now a principal driver of some recent rapid changes in climate?"
Archeologists (not meteorologists) have found some evidence that early humans and cave bears probably had contact.
Original art by Zdnek Burian
Imagine your family struggling to survive in the shelter of a cave and this monster shows up at the door or opening of the cave. You fight the cave bear to defend your family or clan.
The cave bear was a short-term threat. Humans are very good at responding to short-term threats. It's the way we have survived and are "wired" to respond to short term rather than long-term threats. The long-term change rise in global temperature during the last 100+ years is obvious.
The projections of most simulations of global temperatures 50-100+ years from now are pretty consistent and not really different than Michael Mann's "hockey stick". Latest here and below
IPCC WG1 2007
But for so many of us trying to balance this week's budget, or with no good planning for retirement 10-30 years from now (the Cave Bear is far away), how can we think about or make decisions about what might be major changes to the world and our country's climate 100 years from now?
Especially if some short term climate projections are for relatively steady temperatures over the next decade?
It's the question I asked Michael Mann. The climate Cave Bear is not here yet but he's coming. Once it's obvious it's here, our short term instinctive wiring won't help us easily change the climate any more than it helps us change the tide.
Long term decisions, meanwhile are very difficult to make and sure even more difficult to get consensus about from now, about 7 Billion of us on our changing earth.
The August 2011 earthquake in Washington caused significant damage to the Washington Monument and has been closed to the public, as repairs are being done.
If you've been around town, you've likely seen the scaffolding growing up the side of the monument, as crews work hard to make sure the structual integrity of the monument is up to standard. This process has been going on since March 2013. Take a minute to watch this incredible timelapse over the past 54 days of the rising scaffolding and the changing weather over the two month period. Incredible!
It's that time of year again! Get those hats out, put those bets in - the second leg of the Triple Crown is right in our backyard. Yes, I am talking about the one and only Preakness Stakes at Pimlico in Baltimore, Maryland. The race begins at 6:20 PM, Saturday May 18th.
Right now the Pimlico website has the main track as "fast" and in good condition. Since this is the fastest track in the trio of those represented in the "Triple Crown" due to the shortness of the track itself, just a little rain could make for a very interesting outcome. Orb, (who also won the Kentucky Derby at Churchill Downs) is the clear favorite not only to take Preakness Stakes but to take the Triple Crown. However, it is not going to be really fun to bet on him. His odds are currently 1-1 which means you bet a dollar, you get a dollar. I'd say go out on a limb and make things interesting for yourself and then brag to everybody who bet on Orb after you win--but that's just me...and I digress....
Hopefully the track at Pimlico will be nowhere near the condition of the track at Churchill Downs--muddy, soaking wet and slick:
So what is the forecast for the 138th Preakness Stakes?
Well, while although we do have an unsettled pattern of weather for the weekend, it looks like highs throughout the daytime will reach into the lower 70s with cloudy skies and a light SE wind at 5 - 10 mph. A chance of a passing shower or storm is not out of the question through the day but I only give that about a 25% shot.
By the time racetime rolls around at 6:20, temperatures will be right around 70 degrees with overcast skies. A chance of a shower or thunderstorm now at about 20% - 25% shot.
I do get a little concerned that at least one of our models, the GFS is picking up some more widespread rain for Saturday--including for Baltimore. This shows precipitation for 2:00PM EST:
However, I believe at this point the threat of more widespread rain stays well to the south of the D.C. and Baltimore areas through the day on Saturday.
The April climate report shows the month was much cooler than normal across the lower 48, with an average temperature of 49.7°F, which was 1.4°F below the 20th century mean. This made the month the 23rd coolest on record and marked the coolest April since 1997.
Reagan National Airport actually ended up 2.1°F warmer than normal for the month, and would have been even warmer than that if it weren't for 9 of the last 11 days in April with below average temperatures.
April Statewide Temperature Ranks
Above is a look at the statewide temperatures ranks from the National Climatic Data Center (NCDC). As you can see, Virginia actually ranked as the 28th warmest April on record and states on the east coast and west coast had above normal temperatures.
The there's the central U.S. North Dakota recorded its coldest April on record with a statewide average of 31°F! That's an incredible 9.9°F below normal for the month. It reminds me of last March in D.C. which was the warmest on record at 10°F above average.
Alaska also had a cold April, with temperatures 5.8°F below average and it ranked as the 7th coolest April on record for the state. Fairbanks, AK was actually 14.5°F below normal for the month!
Snow cover across the U.S. ranked as the 5th largest snow cover in April in the 47-year period of record. The Care Bears even helped close the season at Breckenridge in Colorado!
Finally, for the first time in a long time, record cold highs and lows outnumbered the record warm highs and lows. In fact, there ended up being three times as many record lows as record highs. Check here to see the latest update for the year.
The Storm Prediction Center has collaborated with the National Weather Service office in Sterling, VA today to upgrade parts of the D.C. area to a Slight Risk for severe storms. This just highlights a greater potential for severe weather in the area highlighted below. The best chances for severe storms will actually be in the southern part of the blue circled area.
Slight Risk Upgrade by the SPC and NWS Sterling
Damaging winds will still be the primary mode of severe weather in any storms that form and location should be along and south of the frontal boundary. A lot of lightning has also been in the storms that have developed around Charlottesville.
Areas south of Fredericksburg in VA closer to Central Virginia and the Northern Neck will have the biggest threat for any severe storms. Stay tuned this afternoon for further updates on our homepage, through social media and on ABC 7 News at 5pm and 6pm.
While the Atlantic Hurricane season is still two weeks away, today marks the beginning of hurricane season in the Eastern Pacific Ocean. And, already things are starting to develop.
The National Hurricane Center has identified a cluster of thunderstorms hundreds of miles south of the Mexican Coast as having the potential of developing into the first named storm of the season. If so, it would be named Alvin. Here's a complete list of hurricane names for 2013. (I always like looking to see if my name is on there, it never is!) This chart of forecast models show that if Alvin develops it should stay away from land.
Computer Model Track
The large majority of hurricanes here travel from East to West or Northwest. The Eastern Pacific season on average is busier than the Atlantic season which can impact us here in D.C.
Average Tropical Cyclones East Pacific
On average there are 15 named storms, 8 of them becoming hurricanes and 4 of those becoming major hurricanes (cat 3 or stronger). We are expecting it to be a near average to slightly below average Eastern Pacific season in terms of numbers of cyclones. One of the reasons for this has to do with the temperature of waters in the equatorial pacific. Notice they are slightly below average in blue.
Sea Surface Temperature Anomoly
We look to that El Nino phenomenon for clues. El Nino Southern Oscillation (ENSO) is the unusual warming of equatorial waters in the Pacific Ocean. When temps are warm and winds are calm, it can make for a busy hurricane season in the Pacific. This year, we are in a "neutral" phase of El Nino and should stay that way through the summer, making for a trickier forecast. More detailed ENSO info here. So, why should we care about this in D.C? The ocean and atmosphere are a continuum of currents and patterns. And, when it's warm in the Pacific, it is often cool in the Atlantic and vice versa. With a near normal to below average season in the Pacific, we are seeing parts of the Atlantic warm up, especially off the coast of Africa.
Atlantic Sea Surface Temperatures
Notice the cooler temperatures hugging the East Coast of the U.S. where we have had a cool May. It's also a bit cool in the northern Gulf of Mexico. Water temperatures need to be 80 degrees to support the "fuel" needed for a hurricane. The Atlantic Season may very well end up a busy one as many hurricane experts are predicting. We are coming off three consecutive "busy" seasons with 19 named storms each of those years. We'll talk and blog more about the Atlantic Season in the next few weeks.
This is a follow-up blog to a story I had on our 11PM news Tuesday May 14. You can see the actual story below but I wanted to expand a few things beyond 1 minute and 30 seconds. Here's the tease :>). Do you live in a city? Marshall Shepherd, a leader in the increasing important field of urban meteorology (and current President of the American Meteorological Society) writes in a recent book that by 2030, 80% of the world's population will live in an "urban environment" So you or you children, do or likely will live, in a city. Do you notice the city is warmer than the "countryside" or "rural area"? Yes cities are warmer, especailly on hot summer nights. It's called the urban heat island or UHI. We can see it.
The concrete, buildings, streets, ashphalt absord heat in the day and just like a hot pot of water are slow to cool at night. I think everyone living in a city, during a summer heat wave knows cities are hotter. Is the city weather different than the "rural" weather? I hope you think yes-at least on summer nights cities are warmer. Also warmer on winter nights-which helps the heating bills. OK is the "climate" (think average summer temperaturers) of the cities different? Is the climate of the cities changing? Yes, I know slipperly slope and not going there. But let's just agree that on a small scale (let's call it a microclimate) the climate is changing. So now what about summer thunderstorms? Here is a series of radar images that Marshall Shepherd thinks shows were started in part by the Atlanta urban area in a northeast flow of unstable air.
The story I did via Skype is with one of the leading researchers in urban meteorology Dr. Robert Bornstein. His ideas about cities affecting thunderstorms came about by talking with NWS forecasters who observed thunderstorm lines that seemed to "split" as they moved into New York City. He wonded why and thought that maybe cities can by either the heat island or the city structure/buildings can change the motion or flow of thunderstorms or even lines of storms.
He set out to test his idea/theory by experiemts. He and students made physical/mathematical simulations of the city and the atmopshere and found in some special cases thunderstorms do split around NYC.