Venice Beach Lightning Map

NLDN Venice Beach-27Jul14

Here is a map for the lightning fatality at Venice Beach yesterday from the National Lightning Detection Network (NLDN) that is owned and operated by Vaisala. The map shows NLDN data for an hour, including the time reported as 2:50 pm (1450 PDT). Several intense cloud-to-ground strokes were detected to the southwest at 1419 PDT and those are probably the lightning events associated with the fatality. Based on my experience, the time of reports in such a situation is uncertain, and has been late in a number of cases. According to the news report, the situation was quite chaotic. Note that the lightning data are accurate to millionths of a second.

Regardless of the timing difference, not much lightning was occurring in this unfortunate case. Within the purple two-mile circle, only 11 events were recorded, and many of them were in cloud.

Source: vaisala.com

The circled admin building and guard house were struck, and the “X’s” represent where rescues were performed.

Typhoon Rammasun Takes on the Western Pacific

Typhoon Rammasun Takes on the Western Pacific

Known to locals as ‘Glenda’, Typhoon Rammasun is the first typhoon to hit the Philippines since Super Typhoon Haiyan in November 2013. Rammasun officially made landfall near Legazpi City on Tuesday, July 15, with sustained winds reaching as high as 105 mph. Atleast 20 people have been killed, and more than 420,000 were forced to evacuate throughout the country. Fortunately, the storm passed just South of the country’s capital of Manila, whose population is more than 12 million. After making landfall, Rammasun weakened from a Category 2 to Category 1 storm.

satelliteimage1
Satellite image of Rammasun, showing Rapu-Rapu Island in the center of the eye on Tuesday, July 15. Photo credit: NOAA/MTSAT

As Rammasun heads toward southern China and Vietnam, it is expected to regain strength as a Category 3 storm. Landfall is anticipated to take place early Friday morning for the Chinese island of Hainan.

typhoonimage
Photo Credit: weather.com

Dr. Jim Means of WeatherExtreme wins weather forecasting competition

jim-1-600x380
Jim Means, Ph.D., was one of three winners of the 2014 May Grey/June Gloom forecasting competition. To come up with his forecast of the number of cloudy days, Jim combined data from the European Center for Medium Range Forecasting (ECMWF) 30 day model run with his own knowledge of the effects of the nascent El Nino on Southern California. Additionally, a recognition of the dominant late winter and early spring patterns– which were favoring above normal sunshine–was also taken into account.

The correct forecast this year was 15 gray/gloom days (we had 17 last year).
We had 6 days in May; 9 days in June. This number is the lowest we’ve had since we started tracking in 2004.
Only 2 of the days were complete gloom days while 8 of the days met the minimum 2 gloom obs required.
During May/June the temperatures at San Diego airport were near normal while temperatures to our north at Los Angeles were warmer than normal.
The 850mb temperatures were higher than normal as were the heights at 700mb. For comparison the same plots from 2013 are attached.

Congratulations to all winners!!
Douglas Alden
Mike Dettinger
Jim Means

The NEXRAD Doppler Radar and Bats…

doppler-1-640x380The great joys of new observational tools include unintended consequences. I can relay a story about the WSR-88D (NEXRAD) Radar to illustrate this.

As a new Warning Coordination Meteorologist at the National Weather Service in 1991 in Norman, Oklahoma, a group of us were the first to be allowed to use the new radar. We knew it would be a great tool to observe and warn for thunderstorms, tornadoes and heavy rain. The contractor turned the radar over to us on March 20, 1991, and we had our first severe weather outbreak the next day, as severe thunderstorms producing tornadoes moved across the Ada, Oklahoma area.

We were amazed at what we could see, but as with most new observational tools, as many or more questions were raised as answered. As we got into the summer, we noticed that around sunset, in locations in both southwest and northwest Oklahoma, a “dot” would appear on the radar in particular locations. The dots would grow into an open circle and disappear. A few curious NWS forecasters decided to make a trip to southwest Oklahoma to check out what was happening.

Their findings were astonishing. They found thousands of bats leaving a cave at sunset, and this was detected by the new radar! The findings were written up, and bat enthusiasts, as well as people who studied bird migrations and even butterflys, had a new tool to use.

Here is a recent example of what the “bat” image looks like. The image is from the Austin-San Antonio radar at New Braunfels, Texas. You’ll notice the Severe Thunderstorm Warning (yellow polygon), and the Flash Flood Warning (green polygon) first. But a look at the areas circled in white show the bats headed out from their caves as night approaches. Central Texas is well known for being “bat-friendly” with the Hill Country caves providing a suitable habitat for the bats.

Jim Purpura
Certified Consulting Meteorologist
Director, Weather Forecasting

purpura@weatherextreme.com