StormBuster OnLine
STORMBUSTER
A Newsletter for Emergency
Managers & Storm Spotters
Fall Edition, 1996
Vol 2, ed 3.
We Need Your Help !
Spotters are asked to report any occurrence of severe weather to your Skywarn EC, Skywarn
Net Controller or directly to us at the National Weather Service. These reports are of
tremendous importance to us since they firmly tell us what the weather is like at the
ground and aid us in understanding what we are seeing on our radar and satellite images.
If you see any of the following eight types of events, please call us! These events are
considered emergency traffic on the Ham network, please relay them to the NWS immediately.
1. Tornadoes, Water Spouts, Funnel Clouds and Wall Clouds (either rotating or not).
2. Damaging Winds that down trees, large limbs and power lines or any wind producing property
damage.
3. Hail of any size
4. Lightning that produces damage, injury or death.
5. Flooding, Ice Jams, Bankfull Rivers or Streams.
6. Measured Rainfall that exceeds 1.0 to 1.5 inches in a 4 hour period.
7. Freezing Rain...all occurrences.
8. Snowfall that exceeds 4 inches in a 24 hour period.
9. Any other event that you feel
may help us determine the severity of storms.
A Change in Aviation Weather Reporting
by Mark R. McKinley
The National Weather Service has joined the rest of the world by using international codes
for aviation weather reports known as METAR. These new codes replace the old surface observation code
known as SA. Aviation forecasts known as Terminal Aerodrome Forecasts (TAF) replaced the domestic
terminal forecasts (FT). These new formats were the greatest changes in aviation weather forecasts since the 1950s.
Under the old domestic code (SA), the order of reported elements was: location identifier,
type of report, time of the report, sky condition (cloud heights and amounts), visibility,
weather or obstructions-to- vision, sea level pressure (in millibars), temperature and
dewpoint temperature (in degrees Fahrenheit), wind direction and speed plus the altimeter
setting (pressure expressed in units of inches of mercury corrected to sea-level). After
the body of the report, remarks could be provided to add more data to the report as well
as climatic information such as maximum and minimum temperatures, six and twenty- four
hour precipitation reports, snow amounts and other information to provide details regarding
important weather that has occurred at the time of the report or within the prior hour.
In the new METAR format, the order of the elements has changed to: the type of report,
location identifier, date and time of the report, wind direction and speed, visibility,
weather or obstructions-to-vision, sky condition (cloud amounts and heights), temperature
and dewpoint temperature (now reported in Celsius) and altimeter setting. Under the new
METAR format, the temperature information is converted to Fahrenheit for use by local
media outlets. The METAR reports are used to create hourly weather roundups that are
placed on the NOAA Weather Wire and Associated Press circuits.
Besides changing the order of the elements that are reported, the manner in which the
elements are observed has also changed. For example, cloud amounts had been coded as
CLR for clear sky (sky with less than a tenth of cloud cover), SCT for scattered
(one-tenth to one-half sky cover), BKN for broken (six-tenths to nine-tenths sky cover)
and OVC for overcast (more than nine tenths of sky cover). The letter X denoted an
obscured sky and -X denoted a partially obscured sky.
Under the METAR code, sky cover is based on eighths of sky cover (called oktas) rather
than tenths. SKC means that the sky is completely clear of clouds, CLR means that at
an automated station the sky is clear below twelve thousand feet above ground level
(meaning that clouds have not recently moved over the laser beam sensor), FEW is used
to describe any cloud amount less than one-quarter of the sky or two oktas, SCT now is
used to describe three or four oktas of coverage, BKN handles an amount from five to
seven oktas and OVC is now eight oktas of sky cover.
An example comparison of the two codes:
With one quarter of the sky covered with clouds at 2800 feet, three quarters of the sky
covered at 4500 feet, visibility 15 miles in light rain showers, temperature 77 and dewpoint of 54,
west wind at 9 knots and pressure of 30.15 inches and a sea-level pressure of 1020.9 millibars.
Under the old code:
ALB SA 1754 28 SCT M45 BKN 15RW- 209/77/54/2709/015
Under the new METAR code:
METAR KALB 181754Z 27009KT 15SM -SHRA FEW028 BKN045 25/12 A3015 RMK SLP209
Units of measure are now included with winds (knots) and visibility (statute miles).
The METAR weather reports are also provided to pilots on what is called the automatic
terminal information service which is provided at busy airports over VHF radio
frequencies.
Some selected smaller airports also provide this weather information, but they are served
by automated observing systems known as ASOS (automated surface observing system) and
AWOS (automated weather observing system). These unattended automated systems do not
provide as much information as those that are supplemented by human observers at airports
served by commercial air carriers.
The TAF code had been used for aviation forecasts at about one hundred airports that
had international service. But almost all of these airports had been provided with
terminal forecasts (FT's) as well. In addition over four hundred
other airports had only FT's provided. North America was the last section of the
world to convert to the TAF code throughout its aviation system. Canada s changeover
took place only weeks before the United States made its change during the beginning
of July of this year.
Quiet Severe Weather Season
by Ken LaPenta
An active severe weather season in 1995 produced 2 memorable events.
First was the Memorial Day (May 29th) tornado that struck Columbia County,
New York and Berkshire County, Massachusetts. Three people were killed in
Great Barrington. Then, during the early morning of July 15th, the region
was struck by a long-lived squall line (known as a Derecho) of unprecedented strength.
Six people were killed with 900,00 acres of forest damaged. An active severe weather
season was followed by a stormy winter. Many cities including New York City,
Hartford and Boston had their snowiest winters on record. The 1996 severe weather
season began early. A storm on January 19th will long be remembered for the
disastrous flooding it caused, but there were also several severe thunderstorms.
After a year of active weather meteorologists
braced for a busy summer. However, as of early September, the severe weather season has been
fairly quiet. Through September 1st, there have been only 77 severe weather events in
eastern New York and western New England. That compares to 190 events in 1995 an 207 in 1994.
No single day produced more than 10 severe weather events in NWSFO Albany's County Warning
Area.
The lack of severe weather may be related to the relatively cool summer we've had.
Hot, humid, moisture-laden tropical air masses are conducive to generating the
instability necessary for severe thunderstorms. The temperature at Albany had only
hit 90 degrees once (in May) as of early September. We had ten 90 degree days last
year. Though severe weather has been lacking, there has been no shortage of rain.
It's been a wet summer with especially heavy rain coming in mid July as the remnants
of Bertha moved through the region.
Although we've had a quiet summer, it's too early to close the door on severe weather.
While the weather in Fall is often tranquil, we just have to look back to 1989 to
remind us how active the weather can be during all. here were 3 major severe weather
outbreaks in October and November that year. On October 15th dozens of severe
thunderstorms struck central and western New York with an F2 tornado reported
in Chenango County. Tornadoes and severe thunderstorms struck the Northeastern
states on November 16th as an intense low pressure area moved through the Great
Lakes Region. One tornado killed 9 school children in Coldenham, Orange County
New York. Just four days later, on November 20th, severe thunderstorms produced
more wind damage across New York and western New England.
NWS and Ham Radio...A Great Team
by Ken French
The cooperative efforts of the communication facilities of Ham Radio together with the
meteorological data gathering and forecasting operations of the NWS has produced a great
team. This cooperative effort provides both an excellent public service function for
Ham Radio while assisting the data gathering and reporting operations of the NWS.
This effort is equally valuable during daily weather reporting and during severe or
unusual weather events and during any resulting emergencies.
If there are several weather data gathering stations that can all connect to a local
2 Meter repeater, a Ham net can be established. One member of the net would be
assigned as a data collection point for the net. When all of the data is collected
and the net is concluded, the collection point individual would contact the local
NWS office and pass the data to them.
If packet radio is available, the task becomes much easier for the reporting stations
and much easier for the NWS office to collect the data. NWSFO Albany has a packet
station for receiving data. The packet radio procedure saves the personnel at the NWS
a good deal of time and trouble since they do not have to collect the data over the
telephone and enter it into a computer. The Greater Capital District Weather Net
uses this system that assures the timely receipt of weather reporting data at a minimum
of effort. NWSFO Albany has a program that converts the data into a format that is
acceptable in their main computer system.
Ham Radio operators, through their local Amateur Radio Emergency Services (ARES)
are set up to handle all sorts of emergency situations. As such, they can work
hand in hand with the NWS to provide both notification of an upcoming event to
the ham community as well as notification of severe weather reports to the NWS.
In summary, if you are a weather observer and a Ham Radio operator, especially
in an area with other hams please consider setting up a ham radio net for data
gathering along with a packet procedure for reporting. For those living in
the Capital District or nearby, the Capital District Weather Net meets daily
at 7:00 AM on the Lake George repeater on 146.730 Mhz. NWSFO Albany's packet
station can be reached on 145.090 Mhz. For further information you may contact
Steve Pertgen at NWSFO Albany. For further information on the Capital District
Weather Net, join us any morning at the time and frequency listed above. You will
be performing a great public service activity for Ham Radio as well as a real
assistance to the NWS.
(Editors note: Ken French is a Cooperative Climatological Observer in Dorset, VT)
Atmospheric Pressure Changes Influence Fish Feeding Activity ?
by Kurt Hemmerich
I've been an avid fisherman longer than the 29 years I've been a professional meteorologist,
and I've tried to relate what I know about the atmospheric science to my hobby. I've
read extensively about sport fishing, and was particularly interested in what various
writers have said about the effect of weather on fish feeding activity. Various
relationships have been examined. Some ring true, but others appear to be implausible.
Perhaps the most improbable theory is that atmospheric pressure changes affect fish
feeding activity. This idea has been declared axiomatically. It states that fish
feed more actively as a storm center or storm front approach because fish are organisms
designed to feed voraciously when the atmospheric pressure is falling. Innumerable
fishing outings have suggested otherwise. Contrarily, when a fair-weather maker brings
relatively high atmospheric pressure, the fish go into a state of suspended animation
and feeding ceases. Once again, there are plenty of exceptions to relate.
There's no way of proving the case one way or the other, so it remains in the realm of
opinion. However, when one considers some basic hydrostatic principles of fluids, it
becomes very reasonable to believe that fish are not sensitive enough to be able to
detect the relatively minuscule pressure changes of the atmosphere when compared to
the relatively great pressure that exists in their aqueous environment.
This is apparent when one considers the relative density of the two fluids under
consideration. Air is only about eight one thousandths s dense as water. To
illustrate the effect this density difference has on the pressure exerted by the
fluids, consider this. The weight of a column of air one square inch across by
20 miles in height (roughly the total depth of the atmosphere) averages to be
14.7 pounds. Another way of putting it, is the atmospheric pressure at the earth's
surface under standard conditions of temperature and moisture is 14.7 pounds per
square inch. Which is equivalent to your barometer reading slightly below 30 inches
of mercury. What does the 30 inches represent?
You could look at it this way. Say you have an old fashioned balance scale
with its 2 pans attached to the horizontal balance arm. If you were able to
put all the atmosphere contained in a one square inch column of air that extended
from the earth's surface to the top of atmosphere in one pan of the scale, you
would have to put a one square inch column of mercury that was 30 inches high in
the other pan in order to bring the two pans of the scale to the same height, i.e.,
become balanced. Now if we were to replace the mercury with water, how much would
be needed to balance the air in the other pan? Ignoring the variations of density
with depth and temperature, you'd need 36 feet or water in a column one square
inch across, or about the depth I fish for large yellow perch and big bluegills
most of the year. At 36 feet the pressure, or weight per square inch, is the
weight of the matter above the fish. This would be the summation of the atmosphere's
weight and that of the water -- two standard atmosphere's of pressure, or about
29 pounds per square inch.
Now let's examine the magnitude of a typical atmospheric pressure change. Excluding
the effect of the usual diurnal changes in pressure, a vigorous storm system would
drop the pressure at a given location about five one hundredths of an inch per hour.
A real whopper of a storm might decrease it by a tenth of an inch per hour. This
is roughly three hundredths or (0.3%) of the total weight of the atmosphere in
an hour. Now consider this. Those panfish are down at 2 standard atmosphere's of
pressure where the change of the atmospheric pressure relative to the total pressure
on the fish is only fifteen hundredths or ( 0.15%) of a standard atmosphere
in an hour.
Can fish detect such small differences in environmental pressure? Fish are highly
sensitive organisms in some respects. They have the proper degree of sensitivity to
survive in a very competitive environment. They can feel vibrations made by objects
moving through the water which can be translated into a kind of "vision." From the
vibrations they can determine the size and shape of the object making the vibrations,
as well as its direction and speed of travel. Some fish have supersensitive olfactory
organs. Others have very keen vision. But it seems unlikely that they can detect such
small pressure differences as occur in the atmosphere, even those associated with
powerful storms.
Even if fish could distinguish a falling barometer from a rising one, what would it
mean to them, and why? What's the logic between a falling barometer and the need
to eat? What's the logic of fish gorging themselves before a storm, and sleeping
during halcyon conditions? It's more reasonable to assume that pressure is only
an indirect factor associated with the more direct causative features inherent with
the storm conditions. The most obvious direct factor associated with a storm would
be visibility changes brought on by changing light intensity and a roiled water
surface. Precipitation not only would dimple the water's surface decreasing light
penetration, but would increase the runoff of water-carrying debris, clouding the
lake or pond.
Fish usually feed most heavily under changing light conditions because a fish's eyes
seem to need time to adapt to the change. This changeability leaves aquatic prey more
vulnerable than when light conditions are stable, and giving the preying game fish a
distinct advantage.
Rapidly changing air temperatures associated with a storm has a slight effect on the
surface temperature of large bodies of water, but probably not enough to effect the
feeding habits of fish. Most of the time fish feed below the surface, and usually
several feet below it. Strongly acidic heavy rain could also decrease the pH of the
water. However, this is likely to affect only the top few feet of water initially,
and as it mixed through a deeper layer, its effect would greatly diminish. If acid
rain was a factor at all, it would be most likely have a negative effect on fish
feeding in shallow water.
So what can be concluded from all of this? Probably nothing with great certainty.
There's plenty of room for opinion here, because unless a person can become a fish
and then relate their experience to us, there's no way we could know for sure.
Obviously we can neither see, smell, feel, hear, or get headaches from changing
pressure like a fish. But, based on what seems reasonable given the hydrostatic
properties of the fluids, water and air, it's my opinion that neither the barometer
reading, nor it's changes has anything to do directly with a fish's feeding activity.
However, although probably not a direct causative factor, pressure change might be
used as a gauge of potential feeding activity since it is often associated with other
factors that directly influence a fish's feeding behavior.
The Summer that Wasn't
Seasonal Climate Series
by Tom Janus
The summer of 1996, which meteorologically consists of the months of June, July,
and August, was most memorable because of the visit of the remnants of Bertha in
mid-July. Otherwise, the season was rather uneventful. Temperature-wise, this
summer was not unusually hot or cool. The temperature at Albany County Airport never
reached 90 degrees again after hitting that mark in spring on May 20.
June in eastern New York and western New England featured numerous stationary or
slow-moving frontal systems. The wettest period of the month was from June 7
through 10, when a stationary front brought 1.46 inches of rain to Albany. High
pressure systems in the Northeastern United States in June allowed Albany to have
slightly more than the average amount of sunshine. Precipitation was typical for
an average June, only 0.02 inches below normal. Thunderstorms were observed on 6
days at the Albany County Airport. June was slightly warmer than normal (1.7
degrees above normal), but there were no unusually hot days. The highest temperature
of the month was 85 F on June 9. The lowest temperature of the month was 41 F on
June 1.
July was wet! In fact, it was the sixth wettest July on record. Precipitation for
the month was 3.96 inches above normal at Albany, thanks to Bertha. The remnants of
the Hurricane dumped 4.17 inches of rain on the Albany County Airport on July 13. The
heaviest precipitation from Bertha fell in the Catskills. The cooperative observer at
Bearsville reported a storm total of 6.90 inches. Two other coastal low pressure
systems brought significant rain to the Albany forecast area. One dampened Fourth
of July festivities with a storm total of 0.97 inches at Albany on July 3 and 4.
Another coastal low brought 1.06 inches at Albany on July 25 and 26. The mean
temperature was 2.1 degrees below normal. The maximum for the month was 86 F on
July 18, and the minimum was 52 F on July 11. Despite all the rain, sunshine for
July was above normal.
August was a sunny month with below-normal precipitation that allowed the region
to dry out. A slow-moving cold front brought 1.28 inches of rain on August 9.
Precipitation for the month at Albany was 0.32 inches below normal. The mean
temperature for the month was only 0.4 degrees above normal. The highest
temperature was 88 F on August 7, and the lowest was 49 F on August 31. Sunshine
at Albany was 80% of the total possible, while a typical August averages only 60%.
October 4th 1987...A day to Remember
by Hugh W. Johnson IV.
September 1987 had been a wet but otherwise fairly normal month weatherwise. The previous
summer of 1987 was typical...albeit on the hot side. No hurricanes or tropical storms had directly
affected the Hudson Valley or Western New England. There were very few clues that an
extraordinary weather event was going to occur heading into the weekend of October 3rd and 4th
1987.
On the weather map...a rather innocuous looking cold front was approaching southern Canada
and the Great Lakes Region early that Saturday morning. Behind the front however...was the coldest
air mass from Canada so far that season. The front slipped across the region to just east of the
Hudson Valley and then began to slow down. This was a clue any area of low pressure or a low
pressure wave was forming along the front. During the afternoon and early evening hours...that is
exactly what happened...a surface low began to develop across the Mid Atlantic region. There
were numerous showers out ahead of the system...and by Saturday evening...a steady cold rain began
to fall across eastern New York and western New England as the storm moved up along the coast
and intensified.
Unfortunately...the usually reliable computer models gave little clue as to what would happen
next. In many situations...forecasters can get an idea what will happen by examining conditions
upstream of their region. That procedure would not work this time. Instead...meteorologists had to
look literally overhead to figure out what was going to happen. That is sometimes a
problem...considering that only two upper level observations are available during a 24 hour period.
The air mass over the Northeast was actually cooling aloft due to heavy rain and melting snow...as
an intensive study by senior meteorologist Ken LaPenta indicated a few months later.
At the surface the rain slowly changed to snow...beginning first across the higher
elevations. Then as the cooler air began working its way to the surface... large wet flakes were
seen at the Albany County Airport by daybreak. The snow became heavy for awhile...and by the
time it was over late in the day...6.5 inches of snow was measured at the airport. This was more
than three times the previous snowfall record for any October day!
Needless to say...this particular snowstorm was a complete surprise to all! Snowfall
amounts were much higher over the Catskills...Helderbergs and Taconics where up to nearly two
feet fell! The snow was very wet and heavy...and came before the leaves had a time to shed. The
result was truly catastrophic. It was considered the most destructive storm to hit the region since
a Hurricane in 1950. Many trees snapped in half...as if hit by a tornado. The destruction could be
seen along the Taconic Parkway a year after the storm. Nearly half the region was in the dark
without power. Ironically...the Mohawk Valley and Adirondacks escaped with very little snow.
The brunt of the snowstorm was felt in an area bounded by a line from about Glens Falls and
Amsterdam southwest to about Honesdale in northeast Pennsylvania...east to Fishkill and then to
Great Barrington.
By the following Monday...temperatures soared back to the 60s under a sunny sky. The
damage assessment had only begun. The Capital District was said to look "like a war zone." It
took as long as two weeks for commercial power to be fully restored to some residents!
Today...with a much improved Skywarn Spotter network...we hope to rely on your timely
by Hugh Johnson IV.
During the past summer, several meteorologists have called many of our Skywarn Spotters
and asking them for their exact location. Why? We are trying to determine as close as possible...the
exact latitude and longitude of each of our spotters. This is being done so we could add this data to
our Azran Whiz program and other programs used during severe weather(Azran Whiz was featured
in the last issue of StormBuster). When potentially severe weather is observed on Doppler radar,
special software will analyze the coordinates of the storm and its motion and then compare it to our
new database of Skywarn Spotters and their latitude and longitude. In this situation we can determine
which spotters are in the path of the storm allowing us to pursue additional information. If the spotter
calls, this new database will allow us to easily determine their position relative to what we see on
radar. John Quinlan is the brain behind this idea. Through a tremendous amount of hard work and
dedication he will finally complete this two year project.
We ask if your address changes or you plan to move out of the region...to please let us know
so we can the make the necessary changes in our ever growing database Thanks for your help!
reports if an event likes this unfolds again. Judging by past performances...including the Adirondack
Derecho and the Great Barrington Tornado of 1995 as well as the Devastating January thaw of 1996,
there will be many challenging weather events ahead!
We cannot rely on Doppler Radar and satellite imagery alone. We really need your reports
and input! Please don't hesitate to give us a call on our toll free, spotter phone numbers.
WCM Words
What's the biggest problem with our spotter network? We don't get enough calls!
- Please don't worry that you'll bother us with your reports. When we are looking at a storm on the
Doppler radar, we often are unsure what exactly is happening on the ground under the storm. Your
report, even if it isn't of SEVERE weather, can help us match the storm structure we are seeing to
ground truth, and decide whether there might be severe weather anywhere in the storm.
If in doubt, CALL! Very often, that critical piece of information YOU have would make our warning
decision MUCH easier!
- We are nearly two thirds of the way
through our efforts to add latitude and longitude to the record of each of our spotters. When
complete, this will make correlation of spotter locations to active storms on the Doppler radar much
more precise. A computer program will be able to present us with spotter names and telephone
locations along a projected storm path, so we can call exactly the right spotter for follow up
information. For those of you who haven't heard from us yet, don't be surprised if John Quinlan,
Hugh Johnson, or one of our other forecasters calls and asks for a ridiculously precise description of
where you are located.
- Our first round of mailing StormBuster
to all of our spotters was a little bumpy. Several adjustments have been made to the mailing list, and
we hope this one goes more smoothly. Hopefully all of the spotters trained in our spring 1996 round
of classes have received their ID cards. If you were trained in 1996, and don't have an ID card yet -
please call my voice mail at 518-456-5807, and let me know.
- A small number of ADVANCED
Spotter Training classes are being scheduled for October and November. Attendance will be limited
to spotters who have attended at least two basic spotter training classes in the past. Information
about locations and times of the sessions will be posted on our Home Page and on Weather Radio
in early October.
- John Cannon, our Doppler radar
program leader has moved on to Gray, Maine. He swapped jobs with Carl Cerniglia from that office,
so you'll be seeing a new name on forecasts and warnings and hearing a new voice on NOAA
Weather Radio.
- The date for our move to the
University at Albany campus is March 1, 1997. If you happen to pass the intersection of Washington
and Fuller in Albany, you can see our new home take shape.
Call for Monthly Precipitation Data
by Michael Caropolo
The hydrology program is continuing work on a new endeavor to accurately diagnose
precipitation amounts across our County Warning Area. This project which will
complement the existing network of surface stations and cooperative observers will
more accurately determine soil moisture conditions. Since many Skywarn Spotters have
their own weather stations or rain gauges and more spotters join us all of the time,
we have begun to look to our spotters as a possible resource. We are looking for only
3 or 4 items. 1) The total monthly liquid precipitation. 2) The total monthly snow
fall. 3) The greatest 24 hour liquid precipitation. 4) And your location. We would
like to collect this information via either post paid mail or through the Internet.
Once we get some feedback and look into this further we will determine the best method
of data collection.
You can mail your observations to the NWS, attention Michael Caropolo at the address
on the last page. Or send your observations to us on the Internet at the following
address, thanks for your help.
StormBuster is a quarterly publication for
Emergency Management Officials and Skywarn
Spotters in the National Weather Service Forecast
Office Albany's County Warning Area.
StormBuster staff...
Jonathan Blaes...
Editor
Dick Westergard...
Warning Coordination Meteorologist
Contributing Authors...
They Make StormBuster Happen!
Jonathan Blaes
Michael Caropolo
Ken French
Kurt Hemmerich
Tom Janus
Hugh W. Johnson IV.
Ken LaPenta
Mark McKinley
Dick Westergard
Address comments to:
StormBuster
NWSFO Albany
Albany County Airport
ARFF Building
Albany, NY 12211
(518) 869-6347
blaes@nwsfo.atmos.albany.edu