Improved Forecasts Headed This Way
National Weather Service getting better radar technology
Pittsburgh Post-Gazette
4 July 2011
By Lauren Rosenthal
Cutting edge weather forecasts are about to hit the Pittsburgh area
before the rest of the country -- but don't expect to see space-age
satellites dotting local farmland or glitzy new maps on the evening
news.
Dual polarization radar technology will be installed near the National
Weather Service office in Moon beginning Wednesday. When the
installation -- which requires technicians to replace a few parts in
the doppler radar systems that have sat at the NWS station for more
than a decade -- is complete, local meteorologists will start using the
radar to deliver more detailed and accurate forecasts. Installation
takes about 10 days.
Pittsburgh is one of five beta testing sites to receive the radar,
which emits signals in both horizontal and vertical directions.
Traditional doppler radar emits only horizontal signals. Dual
polarization radar is scheduled to be installed at every NWS station by
2013.
"We're lucky!" said Richard Kane, meteorologist in charge at the
Pittsburgh NWS office. "The opportunity came along for us and we
decided to take it."
Because of its wealth of rivers, lakes and streams, Western
Pennsylvania is vulnerable to floods, Mr. Kane said. Though doppler
radar can help predict the likelihood and severity of storms, the
single horizontal pulse prevents forecasters from gauging how large the
raindrops are and how quickly they will fall -- crucial information for
predicting flash floods, Mr. Kane said.
Dual polarization radar will provide that level of detail, resulting in
improved flash flooding alerts and increased warning time for residents
in flood zones, he said.
Though tornados are less common in the greater Pittsburgh area than in
Norman, Okla., another beta test site for the dual polarization radar,
KDKA-TV Chief Meteorologist Jeff Verszyla said Western Pennsylvania
residents will still benefit from improved tornado warnings.
Mr. Verszyla pointed to a tornado that unexpectedly hit Westmoreland
County in March with 120 mph winds as a prime example.
"In that particular case, the dual polarization radar would have given
us a higher degree of certainty that a tornado was occurring on the
ground," Mr. Verszyla said. "It would have given a heightened sense for
people within the path of a storm that they needed to take appropriate
action."
Dual polarization radar is more sophisticated than doppler radar, but
Mark Hamilton, an electronics technician at the Pittsburgh NWS office,
said the new system doesn't require any additional maintenance. Mr.
Hamilton said he and other technicians will be keeping an eye on the
radar to learn which parts burn out fastest.
"It's like getting a brand new car," Mr. Hamilton said. "You assume
it's going to last, but new cars have problems, too. The new sites are
going to help us gather that information."
Dual polarization has one immediate drawback: The Greater Pittsburgh
area will be without radar while the new system is installed. The NWS
will rely on radar from the Federal Aviation Administration as well as
NWS outposts in State College, Centre County; Cleveland; Wilmington,
Ohio; and Charleston, W.Va., to make predictions for the Pittsburgh
area.
"The chances that we'll get severe weather between July 6 and July 16
-- well, it's a pretty good chance," Mr. Kane said.
Mr. Kane said he expects the patchwork radar to work well: The NWS used
the same plan when the Moon radar system broke down last summer.
Lauren Rosenthal: lrosenthal@post-gazette.com.