Ok so by now most of us have heard about the absolutely incredible amount of snow areas around Buffalo, in Western upstate New York has received. If you haven’t, let’s just say, in the last 72 hours 5 feet has come down in spots with more expected today, tonight, and tomorrow. Where the heaviest bands of snow reside, neighborhoods may accumulate as much as two additional feet of snow.
**For the whole story and a MINI verbal explanation of what Lake Effect Snow is and how it works…. CLICK HERE!**
The “wall” of snow that is barrelling toward Buffalo. Picture taken from well above the storm.
Here is a brief written explanation of how it forms with a bit more science to it from the folks at the National Weather Service based out of Buffalo:
The Recipe for Lake-Effect Storms
Lake-effect snow forms in the winter when cold air masses move over warmer lake waters. As the warm lake water heats the bottom layer of air, lake moisture evaporates into the cold air. Since warm air is lighter and less dense than cold air, it rises and begins to cool. The moisture that evaporates into the air condenses and forms clouds, and snow begins falling.
Snow clouds most often form in narrow bands where the size and orientation are determined by the shape of the body of water and the prevailing wind direction. In the most extreme cases, the heaviest bands of snowfall may be 20 to 30 miles wide and extend over 100 miles inland from the lake.
Within the band, snowfall rates may exceed 5 inches an hour and be accompanied by lightning and thunder, a phenomenon known as thundersnow. A band of snow can hover over one location for several hours, dropping several feet of snow; however, 10 to 15 miles on either side of that narrow band skies may be sunny with no snow at all.
Lake-effect snows are not confined to the Great Lakes region, although they are most common and heaviest there. Any large body of water can generate lake-effect snow downwind if it remains free of ice. The Great Salt Lake in Utah produces significant lake-effect snow. There’s also bay-effect snow that forms in the same manner as lake-effect snow, only over the ocean. Cape Cod Bay in Massachusetts and Chesapeake Bay in Maryland and Virginia will occasionally produce bay-effect snow.
Additional details from Buffalo….
1. Here is the LAKE EFFECT SNOW WARNING write-up from the National Weather Service as to what residents in Buffalo can expect:
...LAKE EFFECT SNOW WARNING REMAINS IN EFFECT FROM 11 PM THIS
EVENING TO 1 AM EST FRIDAY...
* LOCATIONS...ERIE COUNTY INCLUDING THE BUFFALO METRO AREA.
* TIMING...LATE THIS EVENING THROUGH THURSDAY NIGHT.
* ACCUMULATIONS...ADDITIONAL ACCUMULATIONS OF AROUND 2 FEET IN THE
MOST PERSISTENT SNOWS. THE HEAVIEST AMOUNTS MAY AGAIN FOCUS ON
AREAS FROM SOUTH BUFFALO TO THE NEARBY SOUTHERN AND EASTERN
* WINDS...SOUTHWEST 20 TO 30 MPH WITH GUSTS TO 40 MPH PRODUCING
SIGNIFICANT BLOWING AND DRIFTING SNOW.
* VISIBILITIES...NEAR ZERO AT TIMES.
* IMPACTS...HEAVY LAKE EFFECT SNOW WILL RESULT IN VERY DIFFICULT
OR NEARLY IMPOSSIBLE TRAVEL AT TIMES IN THE HEAVIEST PORTION OF
THE BAND. IF YOU MUST TRAVEL DURING THE LAKE EFFECT SNOW...
EXPECT SEVERE WINTER DRIVING CONDITIONS WITH VERY LOW VISIBILITY
AND DEEP SNOW COVER ON ROADS. SOME ROADS THAT HAVE BEEN CLEARED
MAY BECOME IMPASSABLE AGAIN. SNOW LOADS ON BUILDINGS MAY REACH
CRITICAL LEVELS AND RESULT IN STRUCTURAL FAILURE.
What Is “Fetch”: The distance that an airmass travels over a body of water is called fetch. Because most lakes are irregular in shape, different angular degrees of travel will yield different distances; typically a fetch of at least 100 km (62 mi) is required to produce lake effect precipitation. Generally, the larger the fetch the more precipitation that will be produced. Larger fetches provide the boundary layer with more time to become saturated with water vapor and for heat energy to move from the water to the air. As the air mass reaches the other side of the lake, the engine of rising and cooling water vapor pans itself out in the form of condensation and falls as snow, usually within 40 kilometers (25 miles) of the lake but sometimes up to about 100 miles.
WHY WAS THIS STORM SO POWERFUL:
1.AS WE FOUND OUT HERE IN CENTRAL TEXAS BY TYING OR BREAKING 4 RECORD LOWS IN THE MATTER OF 8 DAYS, THIS WAS ONE COLLLLLLD ARCTIC AIRMASS.
2. IT’S ONLY NOVEMBER!!!! - THIS MEANS THE LAKE TEMPERATURE HASN’T FALLEN VERY MUCH JUST YET, MAKING THE DIFFERENCE IN TEMPERATURE BETWEEN THE AIR PASSING OVER THE LAKE AND THE TEMPERATURE OF THE SURFACE WATER VERY GREAT. THIS LEADS TO ADDED INSTABILITY.
3. THE WIND WAS BLOWING IN SUCH A DIRECTION THAT THE FETCH WAS MAXIMIZED. IT AIR PICKED UP AS MUCH MOISTURE AS IT POSSIBLY COULD BEFORE DUMPING IT ON UPSTATE NEW YORK. THE AMAZING PART IS…. IT HAS BEEN RELENTLESS.