NATIONAL WEATHER SUMMARY
AUGUST 2009
1st-8th…Several
weather disturbances produced areas of active weather across the nation on
Monday. In the East, patches of widespread clouds developed over areas of the
Great Lakes as a cold front became stretched from Lake Superior into northwest
Iowa this afternoon. Two impulses along this front, one over central-southern
Wisconsin and the other in Iowa, instigated pockets of precipitation and
thunderstorms in southern Michigan and northwestern Indiana. More active weather
with stronger to severe storms developed in the Mid-Mississippi Valley as
temperatures warmed during the afternoon and the aforementioned impulses
continued to slide southeastward. There were several reports of nickel to
ping-pong ball sized hail (0.88 to 1.50 inches in diameter) in areas of western
Illinois and northern Missouri. Meanwhile, scattered showers, brief periods of
heavy, isolated rainfall and thunderstorms with a few dangerous lightning
strikes sparked up across the Carolinas as the tail end of a front became
stalled from the Mid-Atlantic through the Tennessee Valley. Increasing showers
and thunderstorms with strong wind gusts also developed in the northern half of
the Florida Peninsula, while patches of light precipitation fell across other
areas of the Southeast. In the West, scattered clouds highlighted a cold front
that fell from southern Canada into the Northern Plains. A small and intense
wave of energy coupled with this front to produce a line of showers and
thunderstorms in the northwestern corner of Montana. Strong winds with gusts of
up to 40 mph and cooler temperatures accompanied these storms. Meanwhile,
moisture from the South triggered scattered clouds over the Southwest and the
Central Great Basin, while high pressure kept these regions under predominantly
dry conditions. Elsewhere, an eastern Pacific low yielded to little change in
California and Pacific Northwest weather activity as it wobbled near the central
California coast. Moist flow from this system gave way to areas of low clouds
and morning fog near the West Coast, as well as pockets of drizzle along the
immediate coastline.
Severe
weather persisted in the Eastern U.S. and initiated over the High Plains on
Wednesday. A low pressure system over eastern Canada created a cold front that
extended from Maine, through New England, down the Ohio River Valley, across the
Mississippi, into the Southern Plains. Scattered showers and thunderstorms were
triggered along the front, while severe storms were produced well ahead of the
front in the Mid-Atlantic States and Southeast. In Rio Grande, Ohio, 0.16 inches
of rain was reported, while penny sized hail fell over Camden, South Carolina
and winds were estimated between 40-45 mph in Asheville, North Carolina. Behind
this system, high pressure build in over the Northern Plains and Upper Midwest.
This allowed for partly cloudy skies with highs in the mid-70s.
Meanwhile, another low pressure system developed over the Central Rockies and
produced a small yet intense warm front that stretched into the Central Plains.
This triggered scattered showers and thunderstorms, some of which turned severe.
Quarter size hail and wind gusts up to 70 mph were was reported in Phillipsburg,
Kansas. No significant rainfall has been reported with this system. Out West, a
strong high pressure ridge allowed for warm, and dry conditions on Wednesday.
Extreme fire conditions stretched from the Northern Rockies, through the Great
Basin, and into the Southwest due to dry and windy conditions. In Elko, Nevada,
29 mph winds with gusts up to 40 mph were reported.
9th-15th…Severe
weather with damaging winds blew through the Central Plains and into the
Mid-Mississippi River Valley on Monday. A low pressure system over the Great
Lakes produced a cold front that extended into Northern Texas and swept eastward
towards the Mississippi. This pulled much moisture in from the Gulf of Mexico,
and allowed for moderate to heavy showers and thunderstorms to develop along the
front, some of which turned severe over Oklahoma and Kansas. In Springfield,
Missouri 1.77 inches of rain was reported, while Reading, Kansas saw 1-2 foot in
diameter tree limbs snap due to an estimated 90 mph wind gust. Also, pea to
penny sized hail fell over Ellis, Kansas. Elsewhere along this front, scattered
storms popped up in the Northeast with light rainfall and no reports of severe
weather development. Just less than a quarter of an inch of rain was reported in
Binghamton, NY. Behind this front, the Upper Midwest and Northern Plains saw a
few lingering clouds with highs in the 70s and 80s. To the south of this front,
high pressure over the Gulf brought warm and humid conditions to the Southeast
and up the East Coast ti the Mid-Atlantic States. These conditions were
favorable for scattered shower and thunderstorm development, but little rainfall
has been triggered over the region. Out West, a strong ridge of high pressure
continued to bring plenty of sunshine and warm temperatures. However, a trough
of low pressure over British Colombia approached the Pacific Northwest, which
pushed low clouds but has not yet triggered any precipitation.
Active
weather continued to fire up across areas of the Eastern US today due to a
couple of persistent fronts. Warm and cold fronts became stretched along the
Mid-Atlantic Coast through the Southeast and across areas of the Southern Plains
as a trough of low pressure advanced eastward throughout the day. Energy
associated with parts of a cold front located along the Mid-Atlantic Coast and
across the Southeast combined with afternoon heating to produce a surge of light
showers to heavy rainfall with thunderstorms across the Carolinas. Thunderstorms
in these states intensified as the afternoon progressed and were accompanied by
areas of quarter sized hail (1.00 inch in diameter) and strong wind gusts. Thus
far, only minor property damages have been reported from these thunderstorms.
Scattered to numerous showers and thunderstorms with frequent lightning and
gusty winds also formed along the central Gulf Coast in the afternoon.
Meanwhile, light, scattered precipitation and thunderstorms developed throughout
areas of the Northeast, the northern Mid-Atlantic and the easternmost regions of
the Lower Great Lakes and Ohio Valley as a warm front extended along the
northern Mid-Atlantic Coast. Strong winds accompanied storms in northwestern
Massachusetts, while penny sized hail (0.75 inches in diameter) pounded areas of
south-central Ohio. In the West, pockets of light rain showers fell across the
northwestern quadrant of the nation as a frontal boundary stretched from the
Pacific Northwest through the Northern Plains. Meanwhile, moderate onshore flow
kept much of the Pacific Northwest and California under slightly cool weather
conditions this afternoon. Elsewhere, hot and dry weather persisted in the Four
Corners due to a dominant area of high pressure.
There
was only a few areas of active weather in the country on Friday.
First,
a complex front moved through the Intermountain West and stretched toward the
West Coast. Some moisture pooled along this front and produced areas of moderate
rain and thunderstorms from eastern Montana through the Dakotas. Another area of
moisture in the Southwest instigated showers and thunderstorms in New Mexico and
Colorado. Unfortunately, no precipitation was available to help firefighters in
California will several major fires. Yet another slow moving front was draped
along the Southeast Coast and over Florida. This allowed significant showers and
thunderstorms to form from Florida through the coast of Virginia. A high
pressure system stretched from the Northeast through the Southern Plains and
produced dry conditions through much of the eastern third of the country. The
Northeast rose into the 70s and 80s, while the Southeast saw temperatures in the
80s and some 90s. The Southern Plains rose into the 90s and 100s, while the
Southwest saw similar temperatures. The Northwest rose into the 60s and 70s.
16th-22nd…Active
weather continued to fire up across the Central and Southeastern U.S. In the
Southeast, Tropical Depression Claudette brought plenty of unsettling weather
activity as it made landfall with the Florida Panhandle last night at tropical
storm strength. While the system experienced some weakening as it trekked
through the Florida Panhandle and south and eastern Alabama, periods of showers,
locally heavy downpours, strong thunderstorms and damaging winds continued to
spread across parts of south-central Alabama and the northwestern Florida
Panhandle. Excessive rainfall put areas near streams, creeks, rivers, and
drainage areas at risk for flash flooding, while gusty winds created a chance
for minor property damage and isolated power outages. Meanwhile, a front located
from the Upper Great Lakes through the Southern Plains produced showers and
thunderstorms with strong winds, and pockets of hail across areas of the Central
Plains and Mid-Mississippi Valley. Incidents of penny sized hail (0.75 inches in
diameter) were reported in northeastern Oklahoma and south-central Missouri,
while wind gusts of up to 62 mph caused minor property damage in southern
Kansas. Elsewhere, a ridge of high pressure brought quieter and warmer weather
to the West today. Inland regions experienced the brunt of this warming, while
areas near the West Coast saw a more modest warm up due to persistent marine
level clouds and onshore flow.
Plenty
of active weather sprang up across the mid-section and southeastern quadrant of
the nation on Wednesday. First, a wave and trough of low pressure produced
pockets of showers and thunderstorms as they dropped southeastward from southern
Canada into the Northern Plains. Significant convective activity also developed
ahead of this system in the Upper Mississippi Valley. The approaching wave
triggered a large area of light to moderate showers and thunderstorms in
east-central and south-central Minnesota and west central-Wisconsin. To the
south, a warm front lifted across the Mid-Mississippi Valley and brought
showers, locally heavy rainfall, thunderstorms, and strong wind gusts to eastern
Iowa and western Illinois. Strong instability made these regions vulnerable to
severe weather development throughout the afternoon and evening hours.
Meanwhile, patches of showers and thunderstorms also developed in southeastern
corner of the Central Plains and the southwestern corner of the Mid-Mississippi
Valley. Second, abundant moisture flow associated with an area of high pressure
anchored just off the Southeast Coast sparked clusters of showers and light to
heavy thunderstorms in the Southeast and the Eastern Valleys. Meanwhile, rich
moisture along the Gulf Coast gave way to numerous bands of precipitation and
thunderstorms along the central Gulf Coast as well as the inland areas of the
central Gulf Coast states. Elsewhere, a strong ridge of high pressure remained
over the West and yielded to fairly quiet weather activity with persistent
warming in the Pacific Northwest. Areas along the West Coast remained cool due
to onshore flow and marine level clouds.
Hurricane Bill remained well off the East Coast and much more of a threat to
Bermuda than it for the mainland. As it curves to the northeast over the
weekend, large waves, some rain, and breezy conditions are expected along the
Northeast Coast, especially in the Cape Cod area. The main weather producer on
Friday was a low pressure system that tracked through the Great Lakes and into
eastern Canada. The associated cold front arched from the Southern Plains
through the Ohio Valley and was on the verge of pushing into New England late in
the afternoon. Moisture ahead of this front produced widespread scattered
showers and thunderstorms in the Southeast, especially along the Gulf Coast. To
the north, areas of rain progressed through the Northeast ahead of the cold
front. Severe Thunderstorm Watches were posted along the Northeast Coast in
anticipation of strong thunderstorms. Several reports of wind damage were
relayed in New England by late afternoon. Breezy conditions were noted behind
the main low pressure system in the Upper Midwest.
The
Northeast rose into the 70s and 80s, while the Southeast saw similar
temperatures. The Southern Plains rose into the 80s and 90s, whiel the Northwest
saw temperatures in the 60s and 70s.
23rd-31st…Most
of the nation saw mild weather on Monday as high pressure covered the Eastern
U.S. and a weak low pressure system tracked through the Northern Plains towards
Canada on Monday. A front lingered over the East Coast from a trough of low
pressure that has moved eastward and well out of the region. The front has
continued to kick up scattered showers and thunderstorms with no reports of
severe weather. Strong winds with gusts up to 23 mph were reported in
Philadelphia, Pennsylvania, while no significant rainfall as been reported. The
Northeast and Mid-Atlantic States saw highs in the mid-80s, while the Southeast
reached into the 90s. Behind this system, high pressure build over the
Mississippi River Valley and brought mostly sunny skies and pleasant weather on
Monday. Air quality was poor throughout the Southern Plains as high pressure
acts to trap pollutants near the surface. To the north, a low pressure system
developed over the Northern Rockies and created a frontal boundary that
triggered scattered showers over the Northern, Central, and Southern Rockies. A
warm front extended into the Northern Plains and kicked up cloudy skies with a
few light sprinkles. Rainfall totals from these fronts remained less than a
tenth of an inch, while temperatures dropped into the 70s in the north. Out
West, a trough of low pressure moved onshore and pushed scattered clouds with
cooler conditions along the the coast. The Pacific Northwest and California saw
highs in the 70s, while the Southwest saw highs in the 90s.
Patches of active weather developed across the eastern half of the nation on
Wednesday. In the East, a warm front slipped into the Central Plains and the
Mid-Mississippi Valley and combined with subtropical moisture to generate a few
areas of showers with locally heavy rainfall and clusters of thunderstorms. The
heaviest concentration of this weather activity developed throughout the
southern half of Iowa. Further south, a trough of low pressure in the Gulf of
Mexico supported scattered showers and thunderstorms throughout the Florida
Peninsula. Significant gulf moisture also coupled with an area of low pressure
circulating in the Lower Mississippi Valley to produce strong to severe
thunderstorms with locally heavy rainfall in eastern/central Texas and
southwestern Louisiana. Meanwhile, air quality issues persisted in northeastern
Texas as atmospheric conditions remained favorable for unhealthy ozone
production. To the north, a cold front produced a bit of cloudy and showery
weather as it stretched from the Upper Great Lakes through the Northeast. A wave
of low pressure along this front instigated light, scattered showers in areas of
southwestern New York. Offshore, Tropical Storm Danny, located to the east of
Nassau, continued to track northwestward with maximum sustained winds of near 45
mph. In the West, high pressure allowed for mostly quiet and warmer weather
conditions throughout the region. Monsoon moisture from the south continued to
trigger light, scattered cloud coverage over the Four Corners.
While
most of the Eastern US saw mild weather on Monday, scattered showers and
thunderstorms persisted in the Southeast. A strong high pressure system built in
from the Plains and stretched from the Upper Midwest and Northern Plains, over
the Great Lakes and Mississippi River Valley, and extended to the East Coast.
This allowed for cool and dry air to pour in from Canada, and brought an early
Fall feeling. Most of these areas saw dry conditions with mostly sunny skies.
High temperatures on Monday remained 5 to 10 degrees below normal in the North
and overnight lows continued to threaten early season frost as temperatures
dipped into the 30s. Meanwhile, a front lingered over the Southeast on Monday
and allowed for scattered showers and thunderstorms to develop over the
panhandle of Florida and southern Georgia. Storms have not yet turned severe and
rainfall amounts remained less than a half of an inch in most places.
Tallahassee, Florida reported 0.40 of an inch of rain. To the West, temperatures
returned to seasonable as onshore flow returned to the West Coast. A trough of
low pressure over the Pacific Northwest brought moisture in from the Pacific
Ocean, and pushed low clouds over the coastal regions of California, while the
Pacific Northwest saw overcast skies with a few scattered showers and
thunderstorms over the Cascades. These storms have not yet turned severe.
Jim G. Munley, jr.
http://www.goecities.com/jimmunleywx
