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.

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Donations:

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.

Other Red Cross Resources:

Find more quick help resources from the Red Cross here. Did you know there was a tornado app from the Red Cross to let people know you are safe after the storm has passed?

Text REDCROSS to 90999 to make a $10 donation.

Donating Blood:

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.

List of F5 and EF5 tornadoes since 1950 - Note how the map is cut off as there haven't been any reported that strong east of the Appalachians.

Photos:

Here is a look at the tornado as it first developed and rapidly intensified from a storm chaser and former NWS Huntsville Meteorologist.

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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.

Severe Storm Threat Today

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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.

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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?"  

Mann and almost 100 percent of 1000s of climate scientists believe the answer is yes, we are changing the earth's climate, as a recent survey of scientists shows.

So what does this have to do with the cave bear? 

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. 

NASA GISS

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?  

UK Met Office Latest Decadal Forecast

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.

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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!

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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.

If you are out and about at Preakness or anywhere- check out our local radar for the Baltimore area:

Baltimore Local Radar | Area Wide Radar

Happy Betting!!!!

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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.

Other April Statistics

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.

FULL CLIMATE REPORT HERE

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LIVE DOPPLER | SOUTHERN MD RADAR

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.

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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. 

Investigation 90

 
 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.

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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. 

  Also his ideas that cities, as  Marshall Shepherd has found in Atlanta, Georgia, under certain conditions may even be the starting point of individual storms.  And here  Washington-Baltimore area  may indeed change lines of thunderstorms in the Washington area as some researchers have suggested.  So here is the short story.  See what you think.  Are cities changing our weather?

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UPDATE (May 10, 2013)

I have received many questions regarding the cicada emergence after my last blog post. I even chimed in on the online chat that was held in Fairfax County.

The main thing that came out of that chat was that "the emergence of cicadas in the D.C. area will be minimum and sparse through portions of Northern Virginia".

Wait, what? I thought they would be everywhere! While that is true in other locations around the region, it seems that they emergence of Brood II cicadas could be few and far between in the District itself. 

According to Gary Hevel from the Department of Entomology at the Smithsonian, Brood II will contain three distinct species in this area.

"Oddly, Northern Virginia in 1996 (last year of Brood II) experienced large numbers of cicadas, while the District and Maryland had minimal numbers," he said. "Because emerging cicadas do not fly too far from their food sources (trees), this described pattern during this emergence will probably be quite similar.

"Exact numbers in the District would be impossible to predict, but D.C. residents can venture to northern Virginia to gain the unique experience of the cicada emergence."

Entomologist Michael Raupp from the University of Maryland agrees and shared with me his thoughts and thoughts from his colleague cicada guru John Zyla.

John produced a wonderful cicada map for our region that puts the nearest emergence of Brood II in Calvert, St. Mary’s, Fairfax, Fauquier, and Prince William Counties as seen below. Professor Raupp concurs with this distribution map; according to his website Bug Of The Week, "the blue/purple color 'II" are the locations that are mostly likely to be severely impacted by the cicadas this year"

Although sightings have already been reported in portions of Fredericksburg and Alexandria, the soil temperatures at 8 inches below the surface has dropped back into the upper 50s as of May 13th, according to the sensor from the cicada tracker at Sutron in Reston, which is a good indication of soil temps through the DC area.

And with a potential frost/freeze on the way for Monday and Tuesday morning, we could see the emergence of the Brood II cicada pushed back even more this month.

Original Post

Spring 1996: President Bill Clinton was about five months into his second term as president; Michael Jordan was back with the Chicago Bulls winning their 4th NBA Championship defeating the Seattle Supersonics, the average price of gas was $1.27 per gallon, Ted Kaczynski, suspected of being the Unabomber, was indicted on ten criminal counts, “The Nutty Professor" starring Eddie Murphy opens in theaters in the U.S. and Nintendo 64 goes on sale in Japan. There was also one other thing on the docket that spring that was plaguing the Mid Atlantic…..this:

Remember that noisy, chirping ugly gigantic insect that died within several weeks after its appearance leaving a blanket of carcasses around just for you to sweep up? Well get ready—because swarmaggedon is upon us once again.

Now just to recap, there are several thousand different species of cicadas throughout the world. Hunkered down below the soil for much of their lifespan, they eventually penetrate our ground in cycles operating on a 13 – 17 year emergence. The species that will emerge this year has not been seen since 1996, or 17 years ago, and is known as the Magicicada Brood II. The majority of their lives are spent underground as immature nymphs, sucking sap from tree roots to survive. The nymphs shed their exoskeletons soon after emerging from the ground and form into full adulthood above ground to breed.

These ugly (yes, I am totally judging) shrimp-size insects are known for their loud mating songs (7kHz), large transparent wings and their red beady eyes that are set wide apart. They will begin to carpet the Mid-Atlantic mostly likely in May this year and by the end of June should mostly be gone and not seen again (this particular species) for 17 years!

They are not harmful to humans and are even considered a delicacy by some people—(I’m talking to all you “high protein/low fat/no carb" dieters out there). Apparently their plant based diet gives them a “green, asparagus-like flavor when eaten raw or boiled” according to Gene Kritsky, a biologist and cicada expert from the College of Mount St. Joseph in Cincinnati, OH. If you are really interested in trying them this year, check out these recipes, cooked up for you by Jenna Jadin, an Entomology major from the University of Maryland: Bug appetit to you brave souls.

Not only will the DMV be affected by these nuisances of nature, but Connecticut, New Jersey, New York, North Carolina and Pennsylvania get in on the fun as well. You may have already seen a few holes in the ground around your yard, however, cicadas will begin to emerge once the soil temperatures at about 8.00” (or 20 centimeters) in depth warm to about 63°/64° degrees F (18°C).

Right now, for most of the area, our soil temperature is anywhere from 50° - 55°. Their bodies have to warm to that temperature threshold (Thermal Synchronization of Emergence) before they begin their trek through the ground and out of the soil around twilight on emergence day.

Cicada are cold blooded therefore they have to rely on warm air temperatures and/or direct sunlight to sing, mate and fly and their black skin color helps that process. The massive emergence by cicadas is based on their strategy of survival and is referred to as “predator satiation”. Pretty much, they reproduce by the millions in order to surprise and overwhelm their predators (birds, squirrels, snakes, lizards, raccoons, etc).

This ensures that enough survivors will be left behind to reproduce. If you dig in the right place, you can on average find about 30 to 50 nymphs in a hole about 1 square foot.
 

Now, even though cicadas are known to have zero defense mechanisms,

they still cause issues from their smelly odor after they die off to the constant and loud piercing call. They also wreak havoc on young plants and trees because females lay eggs in the small areas of these plants causing them to split, wither and die or is referred to as “flagging”.

It is an interesting phenomenon, the female cicada egg laying device. The egg laying act by the female cicada is like a knife that cuts a slit right through the tree and/or plant and that slit is where she lays her eggs. Once the young tree or young plant starts to grow, that slit opens and the plant can die off.

So beware: if you are planning ANY outdoor activities this spring: graduation, wedding ceremony, backyard BBQ, the Magicicada Brood II cicada will be an uninvited guest, unless you have them as part of your meal.

If you are interested in tracking them or helping scientists track the invasion, head on over to Radiolab. Plenty of DIY type of projects for adults and kids during the cicada season. Happy hunting!

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An unseasonably cool airmass will creep into the region Monday morning and hang around through Tuesday behind this weekend's cold front. Here is a reason why you should wait until mid-May to plant many of your flower beds or your garden: Areas of frost and potentially sub-freezing temperatures will be possible in parts of the area.

Forecast Surface Map Tuesday Morning (COD Models)

Here's the set up. High pressure will enter the region Monday and Tuesday making for clear skies and light winds. Temperatures aloft and humidity levels at the surface will also be quite low, allowing for the maximum potential for radiational cooling. At this point in time, the potential exists for portions of our area to see morning low temperatures Monday night into Tuesday morning in the 30's and possibly even 20's in the mountains.

Forecast lows Tuesday morning (WeatherBell Models)

This will allow for some areas to develop frost around the D.C. Metro and potentially freezing conditions along and west of the Blue Ridge through the Shenandoah Valley. I have introduced that beautifully hand-drawn blue line to denote the freezing line, with temperatures forecast to be at or below freezing along and west of the line. This model does show, however, temperatures in the mid 30's closer to D.C. and upper 30's closer to the Chesapeake Bay. D.C. itself may see lows closer to the 40 degree mark.

Continue Reading

The weather pattern across the D.C. area, and much of the East Coast, has been plagued by this pesky upper level low the couple of days.  Clouds, showers, and muggy conditions.  Today the metro region finally broke out into some sunshine, but with unstable conditions, heavy showers and thunderstorms developed.  Even though there was some very heavy rain and even reports of small hail, these storms did give way to some neat looking skies.  Check out this timelapse from the WeatherBug camera on top of our ABC7 studios in Arlington.

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After an absolutely gorgeous first weekend of May, the start of the work week weather took a turn in the opposite direction.  Unfortunately, for those of you not a fan of the grey skies and showers, this weather pattern is here to stay... at least for a good chunk of the work week.  So why the unsettled weather?  Let's explore.

Check out yesterday's satellite image.  Notice the big "swirl" from space.

GOES

I went ahead and drew the features that are present from this system.  The 'L' represents the area of low pressure that is spinning, counterclockwise, over the southeast US.  The blue arrows indicate the onshore, or easterly, flow bringing in Atlantic moisture to the mid-Atlantic.  Air circulates around the low in this counterclockwise fashion.

The low will track northeast over the coming days, but will be slow to do so.  Take a look at the upper level low from about 18,000 ft (500mb).  This is a simulation of where the low will be later this afternoon. 

NCEP

As the low tracks northeast, cloudy and damp weather will persist across the region.  It won't be a complete washout each day this week, but scattered showers will be possible through at least Thursday.  Check out the Weather Prediction Center's quantitative precipitation forecast through Thursday evening.  This forecast shows between 1 and 2 inches of rain over our region, with locally higher amounts over southwestern VA.

WPC

With moderate rain possible over an extended period of time, the National Weather Service has issued a flood watch for parts of the Shenandoah valley through late tonight.  Remember, if you encounter standing water, never drive through it. The latest Flood Watch was extended north into Clarke, Frederick (VA), Hampshire and Mineral Counties as well.

By late Thursday, the low weakens its grip and gets caught back in the overall pattern.  Compare the 500mb heights in this forecast (below) for Thursday night to the same map shown above.  Notice there is a slight dip in the wave pattern, but nothing cut-off (like in the similar image a few graphics up). 

NCEP

For us, this means a less unsettled weather pattern.... sort of, for Friday at least. High temperatures will climb to near 80 degrees by the end of the week, which could initiate a few airmass thunderstorms to develop, but nothing widespread.  A cold front will then slide through this weekend bringing continued chances for showers but drier and slightly cooler air can be expected for early next week. 

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The National Mall will be flooded with pink on Saturday for the Susan G. Komen Global Race for the Cure, and some special students were recognized for their efforts this morning on Good Morning Washington. Kids of all ages from Green Acres School in North Bethesda, MD chatted about their efforts and success with the Race for the Cure while showing off their forecasting skills.  These kids along with 23 other schools helped raise $17K!

The School Spirit Challenge was a throw down to public and private K-12 schools in the Washington metropolitan area to create a team for the 2013 Global Race for the Cure. The Challenge was a strategy to grow K-12 academic teams to make for an unforgettable Race Day experience, and empower our kids to make a difference in their community. School team participation is a community commitment to:

· Raising awareness about breast cancer throughout the school community;
· Celebrating anyone in a school’s community who is or has battled breast cancer
· Helping students, faculty, and families learn, understand and overcome fears about breast cancer and its treatment; and
· Promoting this global outreach effort to end breast cancer as a life-threatening disease.

Check out energetic crowd and how much fun we had together in the clips below as we chat about the Challenge and the forecast.

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Spring is here and that means many of us are spending a lot more time outdoors.  We may have gotten out of the habit of applying sunscreen over the winter.  Here's a common conversation at my house:  "But Mom... it's not even sunny out. Why do I have to wear sunscreen?"  I admit it. My kids absolutely hate slathering on the thick white lotion that protects them from harmful ultra violet rays.  It's even a battle some days. But, I make them do it anyway, and we wear it year round.  Today is Melanoma Monday, as declared by the American Academy of Dermatology. They would like you to "Spot the Orange" and wear that color today to remind others to protect themselves. Did you know that skin cancer is the most common form of cancer?  And, it's highly preventable. Here's is today's forecast Ultra Violet Index. 

UV Forecast May 6th

 
 Wear sunscreen with UVA and UVB proction with an SPF of 30 or greater and apply it every few hours.  If at the beach, make sure it is waterproof.  On a day when the UV Index is "Extreme" it takes less than 15 minutes to get burned. Here is a chart to calculate sun exposure/burn times.  

Sun Exposure/Burn Times Chart

 
You can get your own personalized UV forecast by entering your zip code here.  The sun's rays are strongest from 10a until 2p.  Avoid prolonged exposure during this time.  Staying in the shade or taking shade "breaks" is recommended, so is wearing light weight long sleeves and pants if you're going to be in direct sun at length.  A hat can cover and protect your head and face. And sunglasses with UV protection are a must.  Remember white sandy beaches and water reflect the rays and can double your exposure.  Memorial Day weekend is just a few weeks away. Check out the average UV Index for May.

Average May Ultra Violet Index

 
  Did I mention that sun damage makes you look OLD?  Ever heard of sun spots? Sun damage in your younger years can translate to darker discoloration of your skin. Check out this image from the Mayo Clinic. 

Photo of Sun Damage from The Mayo Clinic

 
 Not a lot of sun expected until Friday in the D.C. area.  Make sure you pull out the sunscreen now, and check if its expired.  If so, time to freshen up and stay sun safe.

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I remember, as a young boy, watching the night sky to see the first artifical satellite call "Sputnik" in 1957.  Our world and our ability to observe our world has changed tremendously in since that small object was launched into orbit around the earth.  Here is a wonderful, beautiful video from NASA that takes us on a journey above our home.  Earth observations from satellites have made incredible advances in the 56 years since I saw the first satellite.  Enjoy.

Here is the link to watch the video in higher resolution.

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Seventy-four tornadoes were spawned on May 3, 1999 including a F5 tornado which struck the suburbs of Oklahoma City. This tornado tracked along a 38-mile path for nearly an hour and a half from Chickasha through south Oklahoma City and the suburbs of Bridge Creek, Newcastle, Moore, Midwest City and Del City. The outbreak caused 46 deaths, 800 injuries, nearly 8000 homes damaged or destroyed and over $1.5 billion in damages.

Meteorologist Devon Lucie here.  I was a meteorology student at the University of Oklahoma that day, and it's one I'll never forget.  At that time, the school of meteorology was located on the top floor of Sarkeys Energy Center at the Northeast end of the campus in Norman, OK, which you can see on the map, is just southeast of the track of the infamous tornado. 

I was on the 12th floor in a room with other students when I witnessed the tell-tale flashes of power lines and transformers failing as the tornado ripped through Moore.  The massive wedge tornado also was crossing over I-35 at that time where a number of people lost their lives while trying to shelter from the twister during rush hour.  The highest wind speed recorded by the Doppler on Wheels found winds of 298mph, which is still the highest wind speed ever recorded on the planet.  It was an awesome, yet horrfying sight... one I never hope to repeat again. 

Outbreak Map from NWS Norman, OK

NOAA National Severe Storms Laboratory webpage on the Outbreak here

NOAA National Weather Service Norman, OK webpage on the Outbreak here

Meteorological Summary of the Event Here

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NASA's Cassini-Huygens mission to Saturn began on October 15, 1997 when the spaceship launched from Cape Canaveral Air Force Station in Florida.  By June 30, 2004, Cassini entered orbit around Saturn to further explore the ringed planet. 

The first mission ended in 2008, but was then was extended - the Cassini Equinox mission - through September 2010.  That mission, too, was extended and the Cassini Solstice mission will continue through September 2017.  

"We're looking at a string of remarkable discoveries -- about Saturn's magnificent rings, its amazing moons, its dynamic magnetosphere and about Titan's surface and atmosphere," says Dr. Linda Spilker, Cassini project scientist. "Some of the mission highlights so far include discovering that Titan has Earth-like processes and that the small moon Enceladus has a hot-spot at its southern pole, jets on the surface that spew out ice crystals and evidence of liquid water beneath its surface."

Back in October 2012, Cassini captured a fantastic, rare image of the planet.  The spacecraft was perfectly positioned in front of Saturn with the sun directly behind the planet.  The result is a uniquely backlit image of Saturn.  What really stands out are Saturn's rings, which scientists have been studying closely, as well as the atmosphere phenomena. 

An image that was just recently released highlights the storms at Saturn's north pole.  The bright red swirl in the middle is a hurricane-like structure (described more below).  The yellow hexagonal feature surrounding the central vortex is the planet's jet stream.  The orange mini-swirls within the yellow colored jet are low-lying clouds.  The bright teal on the outside of image are Saturn's rings.  These are false-colored images, but really make the features pop.

Here's a tighter shot of the hurricane on Saturn.  The spinning vortex resembles a giant rose.  Scientists have learned the eye of the hurricane on Saturn is 20 times larger than the average size of a hurricane eye on Earth (1,250 miles wide on Saturn).  Scientists have also measured cloud speeds as fast as 330 miles per hours.

Keep updated with the Cassini mission through the NASA link. Here's a neat timeline that will also give you Cassini milestones from 1997 through the projected completion in September 2017.

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