NATIONAL STORM SUMMARY

FEBRUARY 2011

1st-5th…The potent winter storm that took a 2000-mile trek across the
nation during the first half of the workweek to directly affect 30
states finally moved off the New England coast on Wednesday. By late
evening, light snow continued to fall across sections of eastern
Maine. Farther to the west, scattered lake enhanced and lake effect
snow fell across sections of New York State, Pennsylvania and Ohio.
However, the intensity and areal coverage of the snow was either
diminishing or moving eastward off the New England coast. As of mid-
evening on Wednesday, the storm's center was located over the waters
of the western North Atlantic off the Cape Sable Island at the
southern tip of Nova Scotia. A weak low-pressure center, which was
located over Upstate New York near Albany, represented the remnants of
the storm center before the system underwent regeneration as it
approached the Atlantic Coast. The storm will be long remembered for
the heavy snow plus the strong winds that resulted in blizzard
conditions across the Midwest. Earlier in the day, the storm had
produced locally heavy snowfall from the Great Lakes eastward into
sections of the Northeast. In addition to "system" snow (or that snow
produced by the storm system), lake-enhanced snow fell as cold winds
associated with the storm traveled across the open and relatively warm
waters of the Great Lakes. Daily maximum snowfall records were set on
Wednesday across the Great Lakes States in Michigan at Grand Rapids
(11.1 inches), Lansing (8.4 inches), Flint (8.3 inches), Houghton Lake
(7.0 inches) and Detroit (4.3 inches); in Wisconsin at Milwaukee (9.1
inches) and in Illinois at Chicago's O'Hare Airport (6.6 inches). Some
stations across Wisconsin and Illinois had received heavy snow on
Tuesday and early Wednesday, bringing storm total snowfall
accumulations to more than two feet. Farther east, snowfall records
for the date were also set Wednesday in New England at Burlington, VT
(11.3 inches) and at Bangor, ME (10.7 inches). A line of rainshowers
developed on Thursday evening across the Southeast. This precipitation
stretched from the Louisiana Gulf Coast northeastward to Georgia and
the Carolinas and was associated with a disturbance in the upper
tropospheric jet stream flow pattern. To the east, a few scattered
thunderstorms developed and were moving to the northeast across
northern sections of Florida during the late evening. These
thunderstorms formed along and to the north of the cold front trailing
from the departed winter storm. After traveling southeastward across
the Southeastern States earlier Wednesday, this cold front stalled
across the Sunshine State, becoming a stationary front.


6th-12th…The Southeast saw active weather on Monday as two low
pressure systems converged over the region. One low pressure system
centered itself over northern Mississippi and the other over the
panhandle of Florida. These systems created a warm frontal boundary
over the Gulf states, while counter-clockwise flow around the system
pulled ample moisture onshore from the Gulf. This triggered periods of
heavy rainfall with scattered thunderstorm development. Cross City,
Florida reported a mid-day rainfall total of 2.22 inches. Meanwhile, a
cold front extended to the north and tracked northeastward up the Ohio
River Valley. This produced a messy combination of snow and rain, with
snowfall rates up to 1 inch per hour across Kentucky and Tennessee.
Paducah, Kentucky reported snowfall totals between 3 and 8 inches.
Another round of winter weather pounded the nation's mid-section and
Southeast Wednesday. After dumping up to 12 inches of snow in
Oklahoma, an inverted trough of low pressure located along the
Southern Plains and Lower Mississippi border supported a mix of rain,
sleet, and snow development in the Ozarks, Lower Mississippi Valley,
and western Tennessee Valley through the afternoon. Arkansas
experienced the heaviest amounts of snow as afternoon snowfall rates
reached to about 1 inch per hour. Significant wintry precipitation
over these regions caused difficult to hazardous travel conditions
with slick roads and reduced visibilities. Persistent snowfall also
resulted in numerous flight delays and cancellations in Oklahoma
during the morning. Winter Storm warnings and Winter Weather
Advisories remained in effect from eastern Texas through the Central
Appalachians during the afternoon.

13th-19th…The Northeast saw a snowy day on Monday, while rain returned
to the West Coast. A low pressure system that developed in the in the
Gulf of Alaska has created a strong cold front that finally pushed
onshore. This system picked up ample moisture before spreading
scattered rain showers over the Pacific Northwest and northern
California. High elevation snow developed across the Cascades, but has
not yet reached the Sierras. Cold air associated with this system
created below normal temperatures and allowed for snow levels to drop
to the foothills of the Cascades. This front also brought strong winds
as it moved onshore. Whidbey Island, Washington reported gusts up to
57 mph, while Truckee, California reported wind gusts up to 53 mph.
Heaviest rainfall developed across Washington with a mid-day total of
1.77 in Quillayute, Washington. Most of northern California saw
between a quarter and a half of an inch of rain, except for a mid-day
total of 0.66 inches in Santa Rosa, California.
The western half of the nation saw the most active weather activity in
the nation today. A trough of low pressure pushed onshore from the
eastern Pacific Ocean and supported precipitation development from the
West Coast to parts of the Continental Divide through the afternoon.
Waves of energy that trekked through California, Nevada, and Idaho
combined with enhanced moist onshore flow to create areas of rain,
hail, thunderstorms, high elevation snow, and strong winds across
these areas as well as the Pacific Northwest. The West remains under a
variety of Winter Storm and Wind Warnings, Winter Weather and Wind
Advisories, and other watches, warnings, and advisories.
The western U.S. saw more wet and snowy conditions on Friday. A deep
and strong low pressure system sitting just offshore of California
continued pushing multiple waves of energy onshore. As moisture from
the Pacific Ocean continued to feed this system, heavy rain and high
elevation snow persisted across most of California. The system has
created a 100 mile wide plume of precipitation that stalled over the
Sierras and western Nevada overnight, creating snowfall rates up to 1
inch per hour in many areas, with up to 3 inches per hour over the
high elevations of the Sierras. By mid-day Friday, the heaviest
precipitation shifted southward to the Central Valley and Southern
Sierras. Thus, snowfall totals in the Northern Sierras ranged from 2
to 4 inches, up to 8 inches above 7,000 feet, while the Southern
Sierras saw up to 21 inches of snow at mountain peaks. Wind advisories
have been issued across these regions due to strong and gusty winds,
with gusts up to 70 mph across mountain passes. Rainfall totals at
lower levels were significantly lower than the previous day, with a
mid-day total of 0.50 inches of rain reported at North Bend, Oregon
and 0.47 at Monterey, California.

20th-28th…Wintry weather hit the Midwest and Ohio River Valley on
President's Day, as a low pressure system moved from the Midwest
towards New England. The system created a frontal boundary that
extended up the Ohio River Valley. Due to warmer temperatures along
the southern side of the front, rain developed from Missouri to
southern Pennsylvania, while snow developed north of the front over
the Lower Great Lakes. Along this front over Ohio and Indiana, saw a
messy combination of frozen rain and sleet. Heaviest rainfall hit
Bloomington, Indiana with a mid-day total of 1.59 inches of rain.
Snowfall accumulation across the Lower Great Lakes ranged from 1 to 2
inches. Just to the north, another trough of low pressure followed
close behind this system and sprinkled snow showers over the Upper
Midwest. Snowfall accumulation remained light with only 1 to 2 inches
in most areas, up to 6 inches in northern Wisconsin.
Active weather persisted across the nation on Friday. Two major winter
storms brought wet and snowy conditions to both the East and West
Coasts. The system out West slowly tracked down the West Coast, and
pushed a strong cold front through California. This triggered periods
of heavy rain across Northern California Friday morning, which quickly
moved toward southern California. This front also brought periods of
heavy snow to the Sierra Nevadas, with snowfall totals from 6 to 12
inches across the northern Sierras. Snow showers diminished across the
Cascades. Strong winds were also associated with this front, with
gusts up to 54 mph reported in Truckee, California. The heavy snow and
strong winds over the Sierras brought dangerous road conditions with
closures at some high mountain passes. Periods of heavy rain developed
at lower elevations across northern California Friday morning.
Rainfall totals ranged form 1 to 1.5 inches, with up to 1.53 inches in
Marysville, California. In the East, a strong low pressure system that
brought heavy snow to the Midwest has moved into the Northeast, and
triggered more heavy snow. Along the warm front, a messy combination
of frozen rain and sleet developed across the New England states.
Rainfall totals reached up to 2.05 inches in New Bedford,
Massachusetts. Winter weather advisories have been issued through
Friday night as heavy snow developed from upstate New York to Maine.
Snowfall rates of 1 to 2 inches per hour have been observed at
Burlington, Vermont. Mid-day snow accumulation reached up to 8 inches
in the extreme Northeast.
A large storm brought snow to the Northeast and produced severe
thunderstorms in the Southeast on Monday. The system quickly moved
northeastward from the Southern Plains and produced two strong frontal
boundaries. A warm front stretched into the Northeast and created
periods of heavy snow showers across Maine, as well as northern
Vermont and New Hampshire. Total daytime snow accumulation ranged from
4 to 8 inches across these areas. This relatively warm system allowed
for rain showers to develop along a cold front that stretched from
Pennsylvania, over the Appalachians, and into the Lower Mississippi
River Valley. The already moist ground allowed for flooding to be the
main concern of this system. Flood advisories have been issued across
most of the Ohio River Valley and into Tennessee. Marion, Ohio saw
2.20 inches of rain, with periods of heavy thunderstorms. Elsewhere,
rainfall totals ranged from 1 to 2 inches. Strong winds accompanied
this front with reports of several trees blown down and damages to
houses with roofs blown off near Hardwick, Kansas. Quarter size hail
was reported in multiple areas including Pikeville, Kentucky, Gilbert,
West Virginia, and Rossville, Georgia. Additionally, a tornado
developed in Estill Springs, Tennessee and caused extensive structural
damage to residences and multiple trees down. Meanwhile, Out West,
another low pressure system pushed over the Pacific Northwest and
moved into northern California. This created rain showers with heavy
snow showers across the Cascades. Tillamook, Oregon reported a mid-day
total of 1.20 inches of rain on Monday. California saw increasingly
cloudy skies with areas of light sprinkles, as this system approached
from the north.