Weekly Weather Discussion: September 6th, 2013

The weekly weather discussion at Stony Brook University reviewed the interesting weather over the past week and discussed the increased activity in the Tropics.

On Tuesday, September 3, 2013 there was a cold frontal passage that coincided with some severe thunderstorms over Eastern Long Island. There was a report of severe hail (greater than 1.00 inch in diameter) in Hampton Bays. The storms were caused by a moist and unstable air mass that was set up over Long Island. However, the unstable air needed a lifting mechanism to tap into that instability and cause the air to rapidly rise and for storms to form and that mechanism was a cold front.

A tropical storm (Gabrielle) had formed in the Atlantic but didn't last long because it moved over the mountainous island of Hispaniola which was too harsh to keep the storm going. Recall that tropical cyclones get their energy from warm, ocean waters and need to maintain their stiff vertical structure which mountains would disrupt.

If a hurricane (not just a tropical storm, of which there have been 7) does not form by September 11th, then the previous record set for latest first hurricane formation in the Atlantic will be broken. There are a couple of areas of tropical convection that may organize into a tropical storm and subsequently a hurricane with time. Of special interest is a fresh wave of convection coming off the coast of Africa. The National Hurricane Center is paying strict attention to it because the environment in which the disturbance is moving is favorable for its development. Low shear (wind speed or direction changing with height that would disrupt the storm's vertical stiffness of its center), high moisture (food for clouds) and high heat content from the warm ocean waters (drives the winds and strengthening of intensity of the storms) are all important and expected to be present in the coming week for this wave. Stay tuned!

Weekly Weather Discussion: August 30th, 2013

          The faculty and students of the Institute for Planetary Atmospheres (ITPA) at Stony Brook University hosts a weekly weather discussion where they lead a scientific discussion of the recent past, current, and future weather. This week's discussion was led by Dr. Brian Colle and was titled, "Why has the Atlantic hurricane season been so quiet and how long will it continue?"
          Dr. Colle began his discussion by providing some statistics to put the current Atlantic hurricane season into perspective. He showed the National Oceanic and Atmospheric Administration's (NOAA) official forecast from this past May for 13-20 named storms with 11 hurricanes and 3-6 major storms. Their latest updated forecast changed a bit and called for 18 named storms with 8 hurricanes and 3 major storms. Despite the relatively “slow start” to the season they are still calling for a lot of activity. The average historical peak for tropical cyclone (TC) genesis in the North Atlantic is about the week of September 10th (NOAA/NHC), so it’s not like we already missed the expected peak period of activity. Dr. Colle discussed the quantity called accumulated cyclone energy (ACE) which measures the relative intensity of each storm by estimating the energy used by each storm (more info here). ACE can be used to compare relative intensities of storms or the relative intensity of an entire season. On a per-month basis, ACE also peaks in September in the Atlantic (from Dr. Ryan Maue’s page). Given this information, perhaps this Atlantic hurricane season shouldn’t yet be written off just yet but it looks like the date of the first hurricane formation may break records (McNoldy, CWG) for being later than previously observed. ACE on a globally integrated scale has been decreasing since 2005 (Maue 2011) but that may be a result of there being less intense storms during the later period from 2005-2012 (Maue’s page).
        What was the deal with the start of this Atlantic hurricane season? To date there have been 6 named storms, none of which reached hurricane strength. Tropical cyclones gain their energy at the surface, unlike strong winter storms that predominately gain their energy from winds at upper-levels of the atmosphere. Tropical cyclones typically start as clusters of disorganized convection (thunderstorms) that blow towards the west off of the coast of Africa. However, they can form from many other locations but those that form from African easterly waves, or the organized storms off of Africa, are the focus of this discussion. Tropical cyclones feed their energy off of warm ocean waters and there are several factors that can hurt their formation and development. They need warm ocean waters, moist air and weak vertical wind shear or strong winds from the west at upper levels when there are strong winds from the east at lower levels.
          Usually, the El Nino-Southern Oscillation (ENSO) when it is in its El Nino phase tends to contribute to a less active Atlantic hurricane season because of increased wind shear over the Atlantic. However, ENSO isn’t a major player this season because it is in its neutral phase, so Dr. Colle showed some plots to explain why the activity had been low starting on July 1st. The first point that he made was that there was anomalously dry air in the atmosphere (-12% RH anomaly) stretching westward from Africa all the way across the Atlantic into the Caribbean especially during the period  August 1st-15th. The Saharan Air Layer (SAL) which is dry, dusty air originating from the Saharan Desert provided a harsh environment for TC development and growth. In analyzing vertical stability or the resistance of the air to rise on its own, the Tropics are more stable this year compared to average conditions (McNoldy, CWG) so that would act to discourage convection. Sea surface temperature (SST) anomaly maps didn’t show too much of an explanation for why activity has been weak because the Tropical Atlantic waters are quite warm. Maps of upper-level shear anomalies did show that during the period August 1st-15th there was a 2-3 m/s westerly shear anomaly in the tropical Atlantic basin. Therefore, the weak activity was shown to be likely tied to the dry air and westerly shear that created an unfavorable environment for TC development.
          How long will this stifled activity last? Likely not long, Dr. Colle explained. Climatological shear values are back in place and the dry anomalies are starting to weaken and the atmosphere is becoming more moist. At the time of the discussion, there was an area of thunderstorms or an National Hurricane Center (NHC) invest area with a 40% probability for the chance of development that should move westward into an area with weaker shear but still some residual dry air. If it makes it past the subtropical high, according to the GFS model, it may encounter a trough that may recurve it and keep it away from the Caribbean and East Coast. We’ll see what happens. Looking beyond this one system and to the rest of the Atlantic hurricane season as a whole, most students at the discussion agreed that they were not ready to give up on the season yet. Assuming that the environment becomes more favorable for tropical cyclone development in the North Atlantic Ocean then this season's forecast for the number of storms may pan out.

For more information about tropical cyclone statistics visit the NOAA/NHC website: http://www.nhc.noaa.gov/climo/
For frequently asked questions about tropical cyclones visit the NOAA/NHC website:
http://www.nhc.noaa.gov/faq.shtml

Sea-Breeze Convection-July 19, 2013

 A large area of ridging aloft along the eastern U.S. slowly retrograded westward and weakened as it moved into to middle of the U.S for the greater part of the last week.

As a result of this ridging, 500 mb heights climbed to near 5910 gpm with 850 mb temperatures topping a toasty 20 degrees celsius at KOKX at 12Z on July 19, 2013. Given mostly clear to partly cloudy skies associated with subsidence aloft, surface temperatures climbed into the low to mid 90's.  In addition to the oppressive heat, a subtropical air mass was situated over the entire northeast U.S. allowing dewpoints to reach into the mid 70's.

On the morning of July 19, the KOKX sounding revealed a relatively shallow unstable layer extending from 950 mb to 750 mb with a strong surface based inversion and little to no wind shear.

Given strong surface based heating associated with mostly clear skies, the forecasted sounding for the KOKX region showed that by 18Z the surface based inversion was largely dissipated and showed a well-mixed layer extending from the surface up to around 850 mb.  While surface based CAPE values were rather low, MU CAPE values topped 3000 J/kg in the Long Island region given the heat and moisture content of the air. 

A sea breeze boundary was rapdily  advected to the north-shore of Long Island through the morning hours due to a southerly flow. The boundary was difficult to identify in base reflectivity loops, but can be seen in surface based observations around noon EST between Port Jefferson and Wantagh through the convergence of the wind field. 

The convective cells appear to be initiated over the same general region near Sunken Meadow State Park (appox. 10-15 miles west of Stony Brook Campus) and train westward along the ill-defined boundary as evident in this loop from 16UTC (1 EST) to 18UTC (3 PM EST).  One hypothesis for the initiation of convection over this region could be that the Sunken Meadow region had the greatest low-level convergence.  This would agree with the mesonet observations around mid-day (not shown) which  showed defined low-level convergence on the north shore of the Middle of the Island near Sunken Meadow State Park.

These cells were  short-lived given weak wind shear profiles and a shallow unstable layer, however, one cell did muster the strength to produce 1" inch diameter hail in Mt. Sinai, New York and penny sized hail on the SOMAS campus. The reports of hail in Mt. Sinai were enough to verify a Severe Thunderstorm warning issued by KOKX moments in advance. 

All in all, the intensity of thunderstorms triggered by a weak sea-breeze boundary was an uncommon occurrence and would have made for a very useful field day if the DOW had been around...

Final Mission: The Long Island Sea Breeze Front

The final mission of the DREAMS Project, Mission #12 if you are keeping track, took place on Monday, July 8th. The goal of the mission was to target the Long Island sea breeze front and any possible pop-up convection in the area. The forecast was very supportive of a robust sea breeze forming around noon so the decision was made to travel to Calverton Airport (EPCAL) to capture it.

The forecast for July 8 called for westerly winds which meant that, unlike the previous sea breeze missions with a southerly wind, the sea breeze front wouldn't be pushed towards the Sound so quickly. If any clouds formed, they should move to the east in a noticeable line. The DOW left Stony Brook University at 10:15 AM and was set up and ready to scan by 11:00 AM. By noon, large cumulus clouds had formed indicating that there were converging winds along the sea breeze front that allowed for near-surface moist air to ascend and form clouds. As the forecast suggested, most of the clouds moved east.

 

The DOW under clouds formed along the sea breeze front in Calverton.

The reflectivity and velocity data both showed a convergent wind boundary indicative of the sea breeze front for most of the afternoon. The pod was deployed which took surface air measurements before the sea breeze front moved to our north and then shifted back to our south. The changes in the surface air characteristics aren't expected to be that apparent because of the characteristics of the surface near the pod, mainly that it was surrounded by sun-soaked concrete.

The DOW under the clouds along the sea breeze convergence boundary. (Photo credit: Matt Sienkiewicz)

A sounding was launched from the New York City office of the National Weather Service in Upton at around 2:00 PM. From that vertical profile of the environmental temperature and dew point, the boundary layer (air near the surface extending up a few thousand feet) showed a temperature profile and wind shift when compared to the air above it that provided further evidence of the sea breeze front. Additionally, the sounding showed that there was only a little bit of instability, one of the main ingredients for convection so the chance for storms looked very small.

The sea breeze front evaporated to scattered cumulus clouds by 3:00 PM and the lack of convection in the area allowed for the final mission of the DREAMS Project to officially wrap up. While the field work is over, the more tedious data analysis begins! However, students understand that hours of staring at a computer screen will be eased by the thought that the data was collected by them personally. With the DOW's visit over, a huge thank you goes out to Rachel H. for being there for us through sea breezes, stratiform rain, and a broken down DOW. Another huge thank you goes out to all the folks at the Center for Severe Weather Research (CSWR) for making the DREAMS Project come true. And lastly, a huge thank you is due to the lead investigators and organizers, Drs. Brian Colle and Kelly Lombardo and NWS liason Jeff Tongue! And, of course, this project would have been nothing without the eager and excited participation of the students, especially those of Stony Brook University.

The posts found on this blog may be updated with more information about the data that was collected once it is analyzed, so feel free to check back. Thank you so much for reading and for following the DREAMS Project!

Mission #10: DOW 6 is Sick and Mission #11: 4th of July Fireworks

Mission #10 of the DREAMS Project at Stony Brook University was originally scheduled to take place on Tuesday, July 2nd but was cancelled because of a lack of activity. The atmospheric pattern was generally stable which inhibits convection so any precipitation in the area was falling pretty lightly which would have made for a boring mission! Mission #10 was then rescheduled for Wednesday, July 3rd. The target was very weak convection (hey, at least it's something!) that was forming in the most atmospherically unstable regions of New Jersey (relative to the region) and moving northeast with the wind around the largely weather-preventing Bermuda High that had taken up shop just off the coast of the Mid-Atlantic.

What's the deal with the Bermuda High? As you probably know, high pressure is known for clear skies and nice weather. This is because with a high pressure at the surface there is actually sinking motion throughout the atmosphere in the vertical direction. The sinking motion causes air to warm and clouds are mostly inhibited because the air dries as it warms and most clouds form from the rising motion of water vapor condensing. While beach-goers were probably happy with the weather, members of the DREAMS Project weren't as happy. Another interesting fact about high pressure is that the air around it moves in a general clockwise, or anticyclonic in the Northern Hemisphere, pattern. Because Long Island was near the western edge of the Bermuda High, the wind was generally from the south-southwest. Any storms that fired up over the southern portions of New Jersey would then tend to move north towards Yonkers and into Connecticut. Therefore, for Mission #10 any chance of catching something would be by pointing the DOW south and hoping a cell or two moved out over the water into our sight. The site chosen for the mission was Jones Beach.

Besides the uncooperative weather, an interesting note about field campaigns like the DREAMS Project is that the success depends solely on the instrument being used. In this case, without the DOW there would be no project. En route to Jones Beach the A/C stopped working in the cab of the DOW and the engine overheated. From a mess of engine coolant, the driver and technician (and saint!) Rachel discerned that this was a big problem. She jumped into action and called her colleagues back at the Center for Severe Weather Research in Boulder, CO and the decision was made that the DOW had to get towed. Thus, Mission #10 was cancelled again, this time due to bad luck!

The DOW being towed away for repair on July 3rd on Montauk Highway.

The DREAMS Project was likely going to see an early end, but thankfully the DOW returned from the great shop in Brooklyn that worked on the 4th of July so that we would have it by our next mission, Mission #11 on Saturday, July 6th. It was decided to scrap the name of "Mission #10" even though there technically wasn't one because it just seemed unlucky after two failed attempts!

Mission #11 was based on an interesting idea from Mission #7's late night at Cedar Beach. During that mission, there happened to be some fireworks going off in CT that students claimed to have seen evident on the reflectivity data from the DOW. The idea to use the DOW to scan a fireworks display had been floating around for some time, so thanks to the students' involvement and the DOW's recovery, a fireworks display was selected and a site determined and Mission #11 was a go! The Peconic Bay Medical Center Family Fun Festival in Wading River was chosen due to its proximity to Calverton Airport (EPCAL), a site we were already pre-approved to use. The DOW set up at 8:30 PM and although after 9:00 PM there were some scattered or more distant fireworks displays, they were not showing up clearly in the reflectivity or velocity data. We kept up hope, though, and at 10:15 our target fireworks display occurred and the smoke from the festive explosions were reportedly visible on the reflectivity data. We weren't show going into that mission whether or not it would work, but we got to enjoy a great show and gather some data for science!

The DOW waiting for the sun to set to scan fireworks in Calverton on July 6th.

After Mission #11 ended at 11:00 PM, that meant there was only one more mission left with the DOW before it left Stony Brook and traveled back to Colorado. It might have been more appropriate to conclude the DREAMS Project with Mission #11 just to go out with a "bang" but we had something more exciting in store (to us at least)-- a sea breeze!

- For more information on the Bermuda/Azores High, please visit this site: http://www.springerreference.com/docs/html/chapterdbid/3926.html

Mission #9: Surprise Strong Storms Strike Early!

The DREAMS Project started off the month of July with a mission. Mission #9 took place on July 1st and a lot earlier in the day then the organizers had anticipated. Strong-to-severe thunderstorms developed early in the morning and propagated northeastward over Long Island and Connecticut. Thanks to the quick action of the DOW team (especially Rachel Humphrey who's been driving the DOW and teaching us how to operate it) the radar was set up in time for the action at Cedar Beach in Mount Sinai. A strong cell passed just to our north and some strong showers developed and moved overhead. After everything cleared up we were in a parking lot with a few inches of water to navigate around!

Weather Prediction Center's 12Z (8 AM) surface analysis.

The forecast for Monday, July 1st was very similar to the previous day's forecast. Most of the ingredients for strong storms were there such as tons of moisture as evident by dew point temperatures in the 70's F and some instability that would increase if there was solar heating during the day. Another ingredient that hasn't been mentioned is called wind shear. A thunderstorm develops from rising air that grows depending on the available moisture, instability, and lifting mechanism. That rising air is concentrated into a narrow swath called an updraft. Wind shear is defined as the change in wind speed or wind direction with height. If there is no wind shear than the updraft is perfectly vertical and when the air rises and condenses its water vapor to form clouds that rain, the rain can actually "choke" the updraft by flooding it with cold, descending air. Wind shear is important to tilt the updraft so that it isn't vertical so that the storm can persist for a longer period of time before dissipating. For Monday, the lifting mechanism was predominantly a stationary front that was situated just east of the Appalachians for most of the day. The forecast was for thunderstorms to develop later in the afternoon when the daytime heating of the surface from the sun would be at a maximum and therefore the amount of instability (CAPE) would also be at a maximum. However, what actually happened was strong thunderstorms got going during the overnight hours and because of the strong wind shear (strong winds from the south near the surface and stronger winds from the southwest higher up) and the added forcing of the stationary front, they organized into a strong line of storms. The original plan for Mission #9 was to catch some late afternoon thunderstorms, but after the National Weather Service issued a tornado warning for Union County in New Jersey around 9 AM (1300 UTC), the DOW team sprang into action.

DOW scanning to our northwest.

Pod in front of approaching storms.

The DOW left Stony Brook University around 10:30 AM and headed to our favorite location on the North Shore- Cedar Beach in Mount Sinai. The plan was that if the line of storms held together as it swept across Long Island, then we'd have the perfect view to our north over the Long Island Sound. We started scanning the skies by 11:30 and watched the line approach our location from the west-northwest. We deployed the pod to measure conditions near the surface throughout our deployment. An interesting feature that we measured with the radar was a possible updraft core. We took vertical slices through the cells as they approached us and saw a narrow area extending up into the storm of velocity values that were opposite of the storm motion. By 1:00 PM a shelf cloud was visible just to our north associated with a strong cell. A shelf cloud forms when there is air rising just ahead of the cooler air gusting outward from a thunderstorm.
 

Shelf cloud over the Long Island Sound (photo by David Stark).

After the strong storm passed to our north and east, we noticed there were a few smaller cells developing to our southwest. We positioned the DOW to take vertical slices of them as they grew and organized into a flash-flood inducing line of storms that passed overhead between 1:15 PM and 3:00 PM. The photo on the right is of the reflectivity data (top screen) and velocity data (bottom screen) that is showing a vertical slice through the second line of heavy rain. The yellows in the reflectivity data show a core of high value of dBZ (the unit of reflectivity) just about to approach the DOW. The velocity data shows mostly blues and purples which meant that all of those rain and cloud drops were moving towards the DOW (i.e. inbound). The students in the DOW had front row seats for the downpours that occurred and could see them approaching using the radar. Despite a leaky roof in the DOW, most of the participants in today's mission were able to keep dry! After the mission wrapped up at around 3:00 PM, water had pooled in the Cedar Beach parking lot to a depth of over four inches in spots! Dr. Kelly Lombardo's car is pictured below sitting in one such puddle. The DOW had to be backed out of a puddle to allow for its occupants to jump down to dry land.

Dr. Kelly Lombardo's car and the DOW sit in a few inches of post-storm water.

Despite having planned on an afternoon/evening mission, the DREAMS Project participants made a great effort to get the DOW out and into position to sample the surprise convection that maintained itself across the Tri-State area. Although we could not have measured the confirmed tornado (with any sites that we have legal permits for), that particular storm jump-started our day. We used that storm to decide that the convection was strong and would hold together as it traveled eastward closer to Stony Brook University. We recorded some great data of the passing convection before it cleared up for the rest of the evening. Therefore, Mission #9 was a success!

- For more information on shelf clouds, please visit this site: http://eo.ucar.edu/webweather/cloudpic1.html
- For more information on thunderstorm ingredients, please visit this site: http://spotterguides.us/advanced/advanced03.htm

Mission #8: A Quick Trip to the South Shore

The DREAMS Project celebrated the end of the month of June by having Mission #8 on Sunday, June 30th. The forecast was for scattered thunderstorms and the impromptu decision was made Sunday morning to try our luck at Smith Point beach in Mastic Beach. The students spent a couple hours with the DOW before wrapping up the quick mission. During that time they were able to scan two areas of weak, scattered storms. Something is better than nothing according to our optimistic sides!

The DOW left Stony Brook University around 2:00 PM and was set up to start scanning by 3:00 PM. There had been some fog at Smith Point but it had lifted a bit upon our arrival. The students were first able to sample some showers and thunderstorms to our northwest. After identifying the area of higher reflectivity with the horizontal scan, they chose to do vertical slices to see the semi-3D structure of the cells.

The DOW at Smith Point ready to start sampling nearby showers and thunderstorms.

Have you noticed that most posted photos of the DOW have the truck on what appear to be stilts? The DOW6 is equipped with 5 hydraulic feet that can have varying heights to make the DOW level on uneven surfaces. Why is this important? With a radar beam of energy coming and going from one point and moving in a circle and even up and down, there's a lot of math involved (especially trig)! To simplify the calculations, the DOW is leveled in reference to the ground that it is sitting on. This also ensures that the radar beam isn't being transmitted at really odd angles and completely missing storms. For the quality of the data, it makes sense to have it level if the DOW is going to be in one place. However, the data is perfectly fine if the radar is operated while the DOW is in motion. We haven't had much storm activity to actually need to operate the radar while in motion, unfortunately!

The level DOW using its hydraulic feet at Smith Point.

By around 4:00 PM an interesting single cell had fired up over the open ocean and was moving north-northeast. The students' attention thus focused onto this cell and they changed the orientation of the radar to take vertical slices of the cell instead of the activity to the northwest. Over the course of a couple hours, the cell grew and became more stratiform (i.e. a broader area of lighter rain versus convective which is heavier showers over a smaller area) before going out of range of the DOW. Interestingly enough, a group of very small-scale cells developed to the southwest of the original cell likely due to the fact that the original cell may have produced some outflow of cooler, denser air that forced air to rise above it. That may be how the cells were activated. At around 6:00 PM the mist began to thicken and cover anything exposed with water droplets. The students luckily all fit inside the DOW and paid attention to the developing fine-scale cells before wrapping up the mission at 7:30 PM. Despite being a quick mission, the students were able to become more comfortable operating the radar and with making decisions about where to selectively perform RHI, or vertical, scans through a particular area of higher reflectivity.

- For an inside look at how the different components of the DOW, please see this operations manual: http://somas.stonybrook.edu/downloads/DOW6OperationsManual.pdf
- For a near real-time update on where we'll be next, please see the DREAMS Project website: http://dreamsproject.weebly.com/schedule.html

Mission #7: Scattered Convection Over Connecticut

The DREAMS Project completed another mission out in the field on Friday, June 28, 2013. Their goal was to study scattered convection (i.e. thunderstorms) that was, yet again, forecast to develop throughout the daytime hours and into the evening. The targeted location was Cedar Beach in Mount Sinai that had a clear view over the Long Island Sound into Connecticut. The students were able to measure the scattered thunderstorms that developed, gain an appreciation for the low-level marine boundary layer and possibly measure the smoke and debris from a fireworks show. A combination of interesting things being picked up by the DOW and incredible public interest kept the DOW at the beach for just under 12 hours! We had thought we were going to be kicked out of the parking lot at one point, but the Public Safety Officers were just very curious about our project.

The forecast for Friday was very similar to the forecast for Thursday regarding the uncertainty of where and when the scattered convection, or thunderstorms, would develop and how far they would travel. The ingredients (moisture, instability, and lift) looked to be most promising in Connecticut. There was a lingering convergence boundary situated there that could likely provide the lifting necessary to fire up the storms. The decision was made to target afternoon convection with Cedar Beach as the chosen location because of its great view to the north and northwest. The DOW left Stony Brook University at 12:15 PM and the pod and radar were set up by 1:30 PM. By that time there were already large, developing cumulus over CT that the DOW was able to scan. The reflectivity data showed that the clouds extended very high and were filled with large droplets and the velocity data showed that the storms were moving away from the radar towards the northeast. 

DOW at Cedar Beach in Mount Sinai for Mission #7.

 

SBU Student Danny C. manning the DOW.

Students set the DOW to take PPI scans, or horizontal scans (PPI stands for Plan Position Indicator), and then once they determined where a storm was they set the DOW to take RHI scans, or vertical slices (RHI stands for Radar Height Indicator). By doing that, they were able to really dissect a particular storm.

Long Island had two of the ingredients for convection (lots of moisture and a fair amount of instability or CAPE) but it was missing the lifting mechanism. Wind was blowing from the south for most of the day so the air was very moist. There were a lot of cumulus clouds that were thin and shallow, or near to the ground, that were forming due to the existence of a moist marine boundary layer, or air close to the surface that can freely rise without much help from any other atmospheric lifting mechanism (like a front). Throughout the day storms were developing over NJ that moved, very slowly, to the northeast that we were eventually able to measure.

Anvil overhead during sunset.

Mammatus observed at Cedar Beach.

The first part of the storm over NJ that came to us was the anvil cloud. The anvil cloud forms when air that is carrying a lot of moisture rises into the developing storm and reaches a level where it faces resistance to rising any more so it instead spreads out horizontally. The anvil usually spreads out downwind of the storm, which is why we could see it so far east when the storm was so far to our west. There was an interesting feature on the underside of the anvil cloud that we saw when we looked up at around 6:00 PM. It is called mammatus and it looks like the cloud has bubbles, or udders from its literal Latin translation. When there is mammatus, it means that at the level of the cloud there is a lot of unstable motion of air. That means that the temperature and moisture of the air in the cloud is not as resistant to upward and downward movement so it moves up and down to give the strange bubbling appearance.

A lot of people wanted to check out the DOW.

There was a lot of public interest in the DOW while we were parked at Cedar Beach. We really do encourage everyone to not be shy and come and ask us what we are doing! Part of the DREAMS Project is to perform public outreach by educating and sparking an interest in weather and the really interesting tool that is visiting Long Island to study it. Long Islanders know that they experience really unique and interesting weather, so all the more reason to come and say hello when you see us! Because of the large amount of interested people asking questions and the active weather to our west, we remained at Cedar Beach until about 11 PM. In doing so, we were able to see a fireworks display to our north over CT. After the display finished, some students claimed to have been able to measure some of the smoke that was created from the festive explosions because there was an area of higher reflectivity values near that location. Even though we have the 4^th of July marked as a “down day” aka a day off, now we are kind of curious what the Macy’s fireworks display in NYC would look like measured with the DOW!

After a very long day of sampling some storms, the DREAMS Project members felt very satisfied because despite not having any strong storms nearby, the curiosity of the public and the eagerness of all of the students to stay out late was invigorating. Hopefully we'll catch some strong storms or a great Long Island Sea Breeze case one of these days before the DOW leaves town, but at least we are all enjoying our experience!

DOW at Cedar Beach after a long day of scanning.

For more information about mammatus clouds, please see the following websites:
- http://eo.ucar.edu/webweather/cloudpic9.html
- http://earthobservatory.nasa.gov/blogs/earthmatters/2013/05/24/mammatus-clouds-over-oklahoma/