of Unusual Weather Events in
Western New York by Don Vallone, Jr.
The following weather coverage documents episodes of severe
weather in upstate New York. Having lived in or near Rochester all of my
life, near the shore of Lake Ontario, I've had the opportunity to experience and
study many of the fascinating weather features that are common to this region
(and some that are not so common!).
The WeatherCam is facing:
East - overlooking Loughton Pond
Note: This may not be a LIVE
There could be a delay of 2 minutes to 6 months.
Pea-size hail is very common at the start of an strong thunderstorm and can last
for several minutes. This is not to be confused with an even more common
occurrence in this region of "grauple". Grauple is small, hard,
icy snow pellets that can fall in a "shower" of more extended periods
of time, typically in the Fall at higher elevations or in a thundershower at any
elevation, and can even accumulate on the ground. Grauple is nothing more
than snowflakes that have partially melted and refrozen while falling through a
suspended layer of warmer air between the cold cloud base and colder air near
the surface. Grauple is similar to sleet, with the exception being that it
starts out as snow while sleet starts as raindrops that freeze on their way to
the surface as they fall into colder air in the lowest part of the
atmosphere. When the process of freezing, melting, and re-freezing occurs
within a towering cumulonimbus cloud due to strong convective wind drafts, the
end result is true HAIL. The size that hail can grow to depends on the
strength of the updraft winds in a thunderstorm. A strong updraft will
support the heavy hailstone and send it rocketing back upward through the wettest
portion of the cloud to get coated with another layer of water droplet and up
even higher into the atmosphere where the new layer freezes to keep the
hailstone growing. When the updraft is no longer strong enough, it lets go
of the hailstone and lets it fall to the ground. Hailstones the size of
grapefruits have been reported.
As a reference, there is a bird feeder on a 6-foot pole next to the largest tree
in the right-hand photo. The water is over 4-feet deep in this part of the
yard! There used to be a park bench sitting among the shade of the trees
near the bird feeder, but that got carried away by the flood waters!
Over the last century, there have been two devastating ice storms in the area,
and they both occurred nearly within a decade! An ice storm happens in the
Spring when heavy rains follow a cold spell and quickly move into an area that
is still at or below freezing near the surface. As raindrops fall on
trees, homes, and power lines, they freeze on contact. If the temperature
near the surface does not warm above freezing, the process will continue until
trees, lines, and roofs can no longer support the weight of the heavy, solid ice
accumulation. The area was under a State of Emergency for two weeks as
residents fought the cold weather without heat or electricity. The damage
from an ice storm can be so severe and widespread that once the ice melts, it
looks as if a war had taken place or a hurricane had passed through. The
first picture below was actually taken from inside the house looking out of the
window. Our house was totally encased in nearly to an inch of solid
ice. The white covering the ground is NOT snow....it is all solid ice!
This area of the country experiences it's own unique microclimate due to it's
location on the shore of one the continent's Great Lakes. One of the
area's "Lake Effect" influences on climate includes a seasonal
lag. Seasons begin and end later in the year than they do for our
neighbors just a few miles farther away from the lake shore due the
thermodynamics of such an enormous body of water. The lake warms and cools
more slowly than the air around it, modifying the immediate on-shore
climate. Drastic changes in temperature and humidity can move through the
area on a clear and sunny Spring or Summer day, bringing clouds, fog, rain, and
a fifteen or twenty degree temperature drop. On a Fall or Winter day, when
the prevailing air mass is cold and dry, the microclimate modifications can mean
that the near-shore land areas will be protected from early frosts and
freezes. A subsequent result of the "Lake Effect" climate is
that the growing season is shifted later into the year by several weeks, meaning
that flowers will bloom "behind schedule" and the autumn harvest can
take place later than in surrounding communities. Perhaps the most
noticeable "Lake Effect" influence takes place in Winter when very
cold air passes over the still warm waters of the big lake. When the
temperature difference is great enough (sometimes this only takes about a ten
degree difference), "steam" rises off the lake and forms heavy, low
cloud plumes which are pushed on-shore by the prevailing wind at low
levels. The clouds plumes can dump very heavy amounts of snow in the lake
shore areas, while just a few miles away the sun is shining brightly in a clear
and cloudless sky!
Note: The dark, broken line across the middle of
picture below, to the left is a 5-foot high wooden fence. Drift were
several feet higher than that. A few miles down the road, there
were patches of grass showing through the light "dusting" of
snow that fell there, while we were snowed in and house-bound for days!
A rainbow is an optical phenomenon created by sunlight entering
tiny water droplets and reflecting back out toward the observer. Whenever
light passes through a different substance, it's velocity is affected by the
density of the substance. When light passes through a raindrop it is
refracted (bent) because the density of water is heavier than air and this
difference actually causes the speed that the light is traveling to slow down
slightly. Since visible light is really a range of frequencies represented
by visible colors, each color is affected differently while passing through the
raindrop. The bending of the light through water is just the enough to
cause the white light to be separated into it's narrower multi-color
components. Because the wavelength (and inversely the velocity) of each
component color of white light is increasingly different from red to blue, each
color gets "bent" at a slightly wider angle than the previous color
and bent again after being reflected off the back of the raindrop, thereby
actually separating the colors enough to be perceived by the human eye.
Red light, having the longest wavelength of all the colors and traveling the
slowest, gets bent the least inside the water droplet. The light that
bounces off the back of the raindrop, back toward the sun (and to your eye if
you happen to be between the raindrop and the sun), is a reflection of this
refracted light off the far side of the raindrop and creates the Rainbow.
Red is always on the outside because it is bent the least while inside the
raindrop. This phenomenon can be created artificially with a lawn
sprinkler on a sunny day.
A small portion of the light gets reflected off the front of the
raindrop (instead of passing through on it's way to your eye) and returns to the
back of the raindrop getting bent even farther along the way. Some of the
light that has been refracted a second time filters out of the front of the
raindrop and back toward the sun (and the observer). This creates a second
(although weaker) rainbow outside of the first and is called a "Secondary
Rainbow". Because the secondary rainbow is a reflection of the
primary, the order of colors are reversed! A very small portion of the
light continues this refracting and reflecting process and creates a third, or
"Tertiary Rainbow" that is much fainter and less perceptible to the
human eye and even farther away from the primary rainbow because it is again
reflected from a different part of the inside of the raindrop. Raindrops
are round (contrary to the popular belief that they are 'raindrop' shaped), so
rainbows are too!
NATIONAL WEATHER SERVICE HAS ISSUED A FLOOD WARNING UNTIL 9:00AM EDT Issue Time: 3:15AM EDT, Thursday Sep 9, 2004 Valid Until: 9:00AM EDT, Thursday Sep 9, 2004
Bulletin - Eas Activation Requested Flood Warning National Weather Service
Buffalo NY 306 AM EDT Thu Sep 9 2004
... The National Weather Service Has Issued A Flood Warning For Erie... Genesee...
York. This Includes The Cities Of Batavia...
Canandaigua... Geneseo... Medina...
The Warning Is In Effect Until 900 AM EDT Thursday Morning...
At 300 AM EDT... National Weather Service Doppler Radar Showed A Large Area Of
Moderate To Heavy Rain Moving North Across The Niagara
Frontier And GeneseeValley.
Radar Precipitation Estimates Show That A General 1 To 3 Inches Of Rain Has
Fallen Across The Area With Another 1 To 2 Inches Expected Before The Rain
Tapers Off Later This Morning. Rainfall Of This Magnitude Will Cause Flooding
Along Area Roads And Other Low Lying Areas.
A Flood Warning Means That Flooding Is Imminent Or Has Been Reported. If You Are
In A Flood Prone Area You Should Protect Your Property Immediately.
Be Very Careful During Your Morning Commute To Work Or School. Remember To Never
Drive Your Vehicle Into Areas Where The Water Covers The Roadway. The Water
Depth May Be Too Great To Allow Your Car To Cross Safely. Vehicles Caught In
Rising Water Should Be Abandoned Quickly. Move To Higher Ground.
Webster, NY Observations:
Wednesday, September 8th :
Francis approaching the OhioValley
bringing bands of heavy, dark clouds.Light
rain from the storm began late afternoon and conditions were very breezy.Leaving work at , moderate rain was
already falling and a stiff breeze made holding an umbrella noticeably
challenging.Flood watches have been
up for the area since morning.Weather
is the top story on radio news reports, warning locals to be prepared for the
potential of 2-5 inches of rain with flooding.
Thursday, Sepember 9th: 3:00AM Bands of heaviest rains move into the area with
sustained NE winds of 30mph and gusts to 40mph rattling windows and waking me up
from a sound sleep.Pressure is
29.75 inches and falling.Looking
outside, visibility is reduced in blowing rain and trees are receiving a
constant battering from the steady wind.The
flood watch has been upgraded to a WARNING for Monroe county as nearly an inch of rain has quickly fallen in the past
hour, and a total of nearly three inches has fallen since the rain started.Radar indicates that the heaviest rain and wind remain on the north-east
side of the storm that is now moving into Western Pennsylvania and New YorkStates, and heavy
rain is expected to last throughout the morning.To the South and West of the center of circulation, the storm has all but
broken apart the culmination of a process which began as the hurricane
stalled in the Atlantic Gulf Stream just before making landfall in Florida last weekend as high pressure began feeding dry air into the
strong storm from the West.
5:00AM Pressure has fallen to 29.68
inches.The center of circulation
appears to be just to our south and should pass overhead in the next couple of
hours.Rain and wind continue.Although the heaviest rain band has moved north over LakeOntario, winds remain impressive with a 42mph gust recorded in the last
5:30AM Sustained winds have settled
back a bit now in the 15-25mph range with occasional gusts over 30mph.What was once the eye of Hurricane Frances, the center of circulation, is approaching.The storm is picking up speed as it moves through Western New York, toward the
St. Lawrence Valley.
6:30AM Pressure continues to fall
now down to 29.63 inches.Rainfall
totals are approaching four inches, especially on the West side of the city.Many roads are closed and under water.Several school districts have closed and RG&E reports power outages
with nearly 5,000 residents without electricity this morning.As dawn breaks, damage from Francis becomes apparent.There is standing water everywhere.There
are reports of a woman in the city who attempted to drive her car through a
flooded road and needed to be rescued as her automobile sank under four feet of
Pressure now 29.59 and still falling.Rain is steady and lighter, but winds have diminished to under 15mph and
are no longer gusting.I believe
that the center of circulation is now sitting directly over Rochester, NY on the West side of MonroeCounty.Emergency crews have been responding to flooding conditions all morning.Some basements have up to a foot of water.Multiple reports of cars under water have kept rescue crews busy on the
roads.I am about to head outdoors
now with my camera
8:20AM Winds are CALM.Pressure is starting to rise again.Looks
like center of circulation is drifting to North and West of city.Wind should change direction and pick up again shortly.
Check out these links to video News Coverage of the flooding from WOKR-Ch13
in Rochester, NY:
Local farmers spent the day Tuesday digging ditches to drain
the potential flood waters away from their crops. Light rain becomes
steady and increases in intensity by 8pm. By midnight, the first of the
heavy squall bands move through the area. The wind suddenly bursts through
the trees and rain pounds the windows. The wind whistles through the tree
branches, ripping off leaves and twigs. The second band moves in an hour
after that with even stronger winds and heavier rain. Rain is falling at
the rate of 2 to 3 inches per hour. The wind is steady at 30mph with gusts
recorded at the airport of 44mph and unofficially over 60mph at local stations
around the region. A flood watch is in effect until 4pm later in the day,
when the rain is expected to stop. It was a sleepless night as Hurricane
Katrina spun through the area. Fortunately, the storm picked up speed as
it moved up the Ohio Valley and into the St. Lawrence Valley. This made
for rainfall totals of less than the potentially devastating amounts that could
have fallen otherwise. Still, Rochester, NY set an all-time record for the
most rainfall ever to fall in a 24-hour period. Widespread minor flooding
and wind damage was left behind by Wednesday morning. Crops were beaten by
the wind-driven rain and some would have been washed away and destroyed had it
not been for drought conditions this summer that left the land parched and
thirsty for the rain that fell. For this reason, runoff and flooding
caused far less damage than they could have if the summer had not been so dry.
After-Effects of Hurricane Katrina
As the storm pulled away into Canada, it left behind devastation
in the Gulf states with thousands homeless or killed. Gas prices reached
record highs around the country as fears of supply shortages began to
materialize. Some local gas stations even ran out of gas and had to close.
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