NATIONAL WEATHER SUMMARY
JULY 2009
1st-4th…Mostly
benign weather developed in the country Friday. A low pressure system gradually
moved through the Northeast and into eastern Canada, providing mainly scattered
showers through New England. These showers diminished as the day progressed. A
few isolated showers and thunderstorms also made their way across the peninsula
of Florida, but only provided some areas of moderate to heavy rain. Perhaps the
strongest weather feature in the country was a low pressure system that moved
out of the Rockies and into the Plains. This feature was strong enough to
produce a line of showers and intense thunderstorms that swept through the
Plains. In addition, areas of rain developed in the Dakotas as well as behind
the low pressure system in the Rockies and Great Basin. Low coastal clouds kept
much of the West Coast cool to mild, with warm temperatures farther inland. The
Northeast rose into the 60s and 70s, while the Southeast saw temperatures in the
80s, 90s, and some 100s. The Southern Plains saw similar temperatures as Heat
Advisories were once again in effect for many locations. The Northwest rose into
the 70s and 80s, while the Southwest saw temperatures in the 90s and 100s.
The
most active weather this Independence Day stemmed from a developing low pressure
system that moved out of the Rockies and into the Plains. A tremendous amount of
moisture streamed ahead of this low pressure system and produced widespread
precipitation from the Plains through the Ohio Valley. Some thunderstorms were
embedded in this precipitation field, but none were severe in nature. A front
swept through New England and instigated scattered showers through the area.
These showers were reinforced by a second front that moved through the area in
the afternoon. Warm Holiday weather was experienced in the Southern Plains and
Southeast as Heat Advisories were in effect due to heat indices well into the
triple digits. Warm temperatures were also making parts of the Northwest
uncomfortable with some areas experiencing temperatures into the 90s. The
Northeast rose into the 60s and 70s, while the Southeast saw temperatures in the
80s and 90s. The Southern Plains rose into the 90s and 100s, while the Northern
Plains sawa temperatures in the 70s.
5th-11th…Unsettled
weather persisted in the South on Monday as a stationary font stretched from the
Southern Plains to the Mid-Atlantic states. This system was fed with ample
moisture from the Gulf, and with warm temperatures allowed for favorable
conditions for scattered thunderstorm development. Severe weather has not yet
been reported, but periods of heavy rain poured over some areas. In Perry,
Florida, 0.78 inches of rain fell in one hour. To the north, a low pressure
system lingered over the Eastern Great Lakes region and triggered light and
scattered rainfall. Less than a tenth of an inch of rain fell over New York and
the Northeast, but thunderstorms have not yet developed.
Meanwhile, in the Central US, a ridge of high pressure built over the Plains and
allowed for mostly sunny skies and warm conditions. Temperatures reached into
the mid-80s in most places, while the Southern Plains saw highs in the 90s.
Further west, monsoonal moisture made its way into the Southern and Central
Rockies on Monday. This brought cool conditions to the region with highs in the
upper 50s and 60s. These storms have turned severe with hail reported in
southern Colorado and northern New Mexico and 0.48 inches of rain fell over Los
Alamos, New Mexico. To the north, a low pressure system dipped into the Pacific
Northwest from British Colombia and triggered cloudy skies with light rain.
Otherwise, the rest of the West Coast saw sunny skies and warm temperatures.
Wet
weather diminished in the Northeast, while a low pressure system in the West
intensified on Wednesday. A strong system developed over western Canada and
pulled warm and moist air northward. This produced a strong warm front that
swept over the Northern Plains and Northern Rockies, and brought scattered
showers and thunderstorms with it. A half inch of rain fell over Deer Lodge,
Montana, with 18 mph winds and gusts up to 35 mph. Some of these storms turned
severe with golf ball size hail reported in Frazer, Montana. This system brought
cloudy skies and cool conditions to the Pacific Northwest with highs in the
upper 50s(F)/ mid-teens(C). Meanwhile, the rest of the West saw warm, dry, and
breezy weather on Wednesday. This allowed for mostly sunny skies in California,
while low humidity in the Southwest allowed for fires to remain a threat. In the
Central US, high pressure hovered over the Central and Southern Plains and
brought warm, humid, and sunny conditions. High temperatures surpassed 100
degrees, thus, heat advisories have been issued for many areas. These conditions
allowed for afternoon scattered thunderstorm development. Hail was reported over
many areas of Kansas and Oklahoma. Further east, persistent stationary front
lingered over the Gulf states, which continued to kick up scattered showers and
thunderstorms. Some areas saw periods of severe weather with heavy downpours.
Penny sized hail was reported and strong winds blew down large tree limbs in
Clanton, Alabama. In Albany, Georgia, 0.78 inches of rain fell in one hour.
In the
Northeast, a low pressure system finally started to push out of the region, and
allowed for clearer skies and drier weather. The region saw light rain with
heaviest rainfall near a half of an inch in Waterboro, Maine.
The
Northern Plains and Upper Mississippi River Valley saw active weather on Friday,
while scattered showers and thunderstorms persisted in the Southeast. A strong
low pressure system tracked eastward through central Canada and created an
intense cold front that swept through the Central US. The system pulled moist
air into the region from the Gulf of Mexico, which allowed for scattered showers
and thunderstorms to develop ahead of the front. Some of these storms turned
severe with 64 mph wind gusts reported to have torn down a tree limb of 1 foot
in diameter in Story City, Iowa. In Ames, Iowa, 0.40 inches fell in one hour,
while Davenport, Iowa reported a total of 1.67 inches of rain and 23 mph winds
with gusts up to 31 mph. Ahead of this system, the Ohio River Valley and
Northeast saw an increased cloud cover with highs remaining in the 70s and 80s.
Rain has not yet been reported over these areas. In the South, a stationary
front that has lingered over the region for a few days continued kicking up
scattered showers and thunderstorms on Friday. Moisture from the Gulf and
Atlantic Ocean fed into this system and spread light rainfall over northern
Florida and southern Georgia. In the Southern Plains, a heat advisory remained
in effect on Friday as high pressure allowed for temperatures to surpass 100
degrees in most places. Fires remained a threat as windy conditions persisted
with 23 mph winds and gusts up to 32 mph reported in Oklahoma City, Oklahoma. In
the West, monsoonal moisture over the Southwest, in addition to a small trough
of low pressure overhead, allowed for high level scattered showers and
thunderstorms to develop. Dry conditions at the surface allowed for most
precipitation to evaporate before it reached the ground. Meanwhile, the West
Coast remain sunny and warm with high pressure over the region.
12th-18th…The
Northern US saw unsettled weather on Monday as a low pressure system dipped in
from Canada. The system finally advanced over the Pacific Northwest from British
Colombia and pushed a frontal boundary through the Northern Rockies and into the
Northern Plains. This system tracked eastward along the Canadian border and
counter-clockwise flow created a warm front ahead and a cold front behind this
system. The warm front kicked up showers and thunderstorms with periods of heavy
rain and severe weather over the Dakotas. In Bismark, North Dakota, 0.60 of an
inch of rain was reported while quarter size hail fell over Dupree, South
Dakota. Also, 60 mph winds and 1/2 inch in diameter hail was reported in Mission
Ridge, South Dakota. Meanwhile, the Pacific Northwest and Northern Rockies saw
light rain showers with less than a half of an inch of rain reported, with
scattered thunderstorms in Montana with hail and winds estimated between 40 to
50 mph in Shelby, Montana. Elsewhere in the West, warm and seasonable conditions
continued as a ridge of high pressure sat over the West Coast. Hot and breezy
conditions allowed for extreme temperatures and fires to remain a threat over
the Southwest. To the South, a large ridge of high pressure continued to
dominate the Southern Plains and Southeast. This created a stationary front that
extended from the Carolinas, across the Gulf states, and into eastern Colorado,
which kicked up scattered showers and thunderstorms throughout the day. Storms
turned severe over the Lower Mississippi Valley as abundant Gulf moisture fed
into the front. Strong winds blew a tree onto a mobile home in Calhoun City,
Mississippi. In Jacksonville, North Carolina, the front triggered 1.20 inches of
rain. The rest of the Eastern US saw mild weather has high pressure hovered
brought mostly sunny skies and pleasant weather to the Great Lakes and Upper
Mississippi River Valley. Seasonable conditions persisted with highs in the 70s
and 80s. However, a trough that lingered over the extreme Northeast continued to
produce mostly cloudy skies and light rain.
Thunderstorms swept through the Midwest and Ohio River Valley on Wednesday,
while excessively hot temperatures persisted across the South.
A low
pressure system continued to track eastward through Canada and produced a strong
frontal system that extended over the Central US. A warm front stretched over
the Great Lakes and into the Southeast, while a cold front extended down the
Mississippi Valley and wrapped westward into the Central Plains. Between these
two fronts, scattered showers and thunderstorms developed, none of which have
turned severe. In Petersburg, Illinois, 0.82 of an inch of rain was reported
while Minneapolis, Minnesota reported 21 mph sustained winds with gusts up to 35
mph. Light and scattered showers developed over the tail end of the cold front,
with a tenth of an inch of rain reported in Wichita, Kansas and wind gusts up to
31 mph. South of this system, hot and dry air moved in from Mexico, and allowed
for fires to remain a concern over the Southern Plains and Southwest. Heat
advisories remained in effect as temperatures surpassed 100 degrees in many
areas again on Wednesday. In the East, high pressure allowed for mostly sunny
skies and pleasant weather over New England. The Northeast saw highs in the 70s
and the Mid-Atlantic states reached into the upper 80s. Humid conditions in the
Southeast, however, triggered scattered afternoon showers and thunderstorms and
reached into the mid-90s. In the West, high pressure over the West Coast
continued to bring warm and dry weather on Wednesday. The Pacific Northwest saw
plenty of sunshine with highs in the upper 70s, while most of California
remained sunny with highs in the 80s and 90s.
19th-25th…Plenty
of weather disturbances produced active weather across the nation on Monday. In
the Central U.S., several waves of energy combined with significant moisture
flow to produce areas of scattered showers and thunderstorms throughout the
Plains. Post frontal showers, thunderstorms, and areas of hail developed across
the Dakotas this morning as a cold front pushed through the Northern Plains. A
wave of low pressure along this front enhanced instability across this region
and produced additional showers and thunderstorms in South Dakota. To the south,
strong northwesterly flow streamed into the Central Plains and combined with a
wave of low pressure over this region as well as afternoon warming. This
translated into a batch of showers and thunderstorms throughout eastern Kansas.
Meanwhile, waves of energy moving through northern-central Texas also triggered
scattered precipitation and thunderstorms throughout the afternoon. Increasing
instability throughout the Plains put the regions at risk for severe weather
activity with damaging winds and large hail throughout the afternoon. In the
East, showers and thunderstorms sparked up across areas of the Mid-Atlantic as a
frontal boundary remained positioned along the Mid-Atlantic Coast. Strong winds
accompanied storms in central Virginia and led to a few minor damages thus far.
Elsewhere, lines of showers, thunderstorms, and hail developed throughout areas
of central and southern Florida as waves of energy moved through the base of a
trough of low pressure that extended through the southeastern gulf waters. In
the West, moist and unstable air remained anchored over the Great Basin and the
Southwest today. A weak wave of low pressure enhanced instability throughout
these regions and created a few isolated thunderstorms throughout southern
Nevada and northern Arizona. High pressure over the remainder of the West kept
temperatures at warm to hot values and allowed fairly tranquil weather to
develop across the inland regions. Meanwhile moist, onshore flow produced cool,
morning fog along areas of the West Coast and created a chance for isolated,
high-elevation thunderstorms.
Several active weather events developed across the nation on Wednesday.
In the
East, a low pressure system kicked up unsettling weather activity throughout
areas of the Eastern Valleys and the Upper Great Lakes as it trekked
northeastward into the southern Ohio Valley this afternoon. The system pulled
abundant moisture from the Gulf waters and led to heightened instability across
these regions. As a result, ongoing showers, with brief periods of heavy
downpours, scattered thunderstorms, and areas of small hail developed in the
Ohio Valley and areas of the western Tennessee Valley. Significant moisture also
spread into Michigan and generated bands of scattered thunderstorms with pockets
of torrential downpours and isolated flooding. Elsewhere, a patch of convective
activity located just east of the Southeastern Coast produced thunderstorms over
the nearby coastal waters. Moisture flow associated with this disturbance also
yielded to scattered precipitation along the Mid-Atlantic Coast. This system
continued to show a low chance for tropical development during the next couple
of days. In the West, a weather disturbance over the Southern High Plains
generated lines of showers and thunderstorms with areas of moderate to heavy
rainfall across eastern New Mexico and northwestern Texas. Meanwhile, monsoon
moisture from the south continued to spark up a few scattered showers and
thunderstorms across Arizona. The remainder of the West saw mostly dry
conditions with warm to hot inland temperatures as a ridge of high pressure
remained the dominant weather feature throughout the region. Moist, onshore flow
yielded to areas of fog and cooler weather along the coast, as well as a few
high elevation thunderstorms.
The
country saw multiple areas of active weather on Friday. A low pressure system
continued to track through the Northeast and pulled a cold front with it which
turned into a stationary front and hovered over the East Coast. This front
kicked up scattered showers throughout the day, with heavy rain and severe
thunderstorms that popped up in some areas. Most areas saw less than a half of
an inch of rain, while golf ball to baseball size hail was reported in Pantego,
North Carolina. Also, strong winds blew tree limbs down in Camp LeJeune, North
Carolina. Syracuse, New York reported 0.12 of an inch of rain with 12 mph winds
and gusts up to 20 mph. Seasonable temperatures returned to the Eastern US with
highs in the 80s in most places. In the Central U.S., a trough of low pressure
dipped into the Northern Plains and Upper Midwest from Canada and brought
scattered showers and thunderstorms with it on Friday, some of which turned
severe. Rochester, MN saw 1.20 inches of rain and pea to penny size hail fell
over Mantorville, Minnesota. In Cresco, Iowa, strong and damaging winds blew
down multiple trees and power lines, one tree fell on a woman in a park and
caused multiple injuries. Elsewhere, the Central and Southern Plains saw warm
and dry conditions as high pressure built in from the West. Highs reached into
the 90s and 100s. Scattered showers and thunderstorms popped up across the
Southwest with most precipitation evaporating before hitting the surface.
Meanwhile, cooler conditions returned to the West Coast with onshore flow which
triggered partly cloudy skies. The Pacific Northwest reached into the 60s and
70s and most of California remained in the 70s and 80s.
26th-31st…The
East Coast saw severe weather again on Monday as a cold front lingered over the
region. A low pressure system over eastern Canada produced two frontal
boundaries over the U.S. One cold front extended from New England, down the Ohio
River Valley, and into the Lower Mississippi River Valley. Strong flow from the
Gulf of Mexico changed the front into a warm front as is extended into the
Southern Plains. This is where it kicked up heavy showers and thunderstorms as
ample Gulf moisture fed into this system. Ahead of this front, a trough of low
pressure extended from the low pressure system in Canada and pushed through the
Southeast and Mid-Atlantic states, which triggered severe storms. Significant
rainfall was not reported, but two inch in diameter hail was reported in
Glendon, North Carolina, while strong winds blew multiple trees down and flipped
boats over in Reed Bingham State Park, Georgia. In the Northeast, the cold front
also triggered severe weather, with reports of hail in Fenwick Island, Delaware
and a billboard was blown down in Pittsburgh, Massachusetts. The second cold
front swept through the Northern Plains and Upper Midwest, and brought overcast
skies with a few light sprinkles over Wisconsin. No significant rainfall has
been reported. This front also extended into the Northern Rockies and triggered
light rain over Montana. Meanwhile, the West Coast remained hot and dry as high
pressure sat over the region on Monday. Heat advisories remained in effect for
the Pacific Northwest and the Southwest as temperatures in the north reached
into the 90s, while the southern deserts surpassed 110 degrees.
Severe
weather persisted in parts of the Eastern US on Wednesday due to a relatively
stagnant low pressure system over eastern Canada. The system produced a
stationary frontal boundary that extended from the Northeast, down the East
Coast, and into the Southern Plains. The system pulled moisture in from the Gulf
and allowed for humid conditions across the Southeast. This kicked up scattered
showers and thunderstorms throughout the day, which turned severe across New
England. Ping pong size hail fell over Valley Forge, Pennsylvania, while strong
winds blew multiple trees and power lines down over most of the region. Areas
with strong thunderstorm development saw periods of heavy rainfall. Custer City,
Pennsylvania reported just over a half of an inch of rain. The tail end of this
front also kicked up severe weather with 72 mph winds reported at Midland
International Airport, Texas. To the north, cool air poured into the Great Lakes
region from Canada. This allowed for mostly sunny skies with highs only reaching
into the upper 60s and lower 70s. Another trough developed over the Northern and
Central Rockies moved into the Northern and Central Plains, and triggered
scattered showers on Wednesday. Rainfall totals remained less than a half of an
inch, while the system produced damaging winds with a gust up to 58 mph in
Security, Colorado.
Meanwhile in the West, the Southwest saw a break in extremely hot conditions,
while the Pacific Northwest remained unbearable. The dominant high pressure
ridge allowed for temperatures to approach 100 degrees again in the north, thus,
a heat advisory has remained in effect for Oregon and Washington.
The
most active weather in the country was pushed into the eastern third of the
country by a long front that moved across the Appalachians and towards the
eastern seaboard on Friday. A significant amount of moisture streamed ahead of
this front and instigated widespread showers and thunderstorms along the Gulf
Coast and through much of the Southeast. More substantial rain fell in the
Mid-Atlantic and Northeast. There were several reports of wind damage from
eastern Georgia through southern New York due to the widespread thunderstorms
activity. Another front spread southward into the Northern Rockies and Northern
Plains from Canada. In contrast to the aforementioned front, this feature did
not carry a tremendous amount of moisture. Thus, areas of rain fell along the
front in the Dakotas and Intermountain West. The rest of the West remained dry
and warm to hot. The Northeast rose into the 70s, while the Southeast saw
temperatures in the 70s and 80s. The Southern Plains rose into the 80s and 90s,
while the Southwest saw temperatures in the 90s and 100s. The Northwest was
cooler by the coast with temperatures in the 70s, while inland locations rose
once again into the 80s and 90s.
Jim G. Munley, jr.
http://www.goecities.com/jimmunleywx
