NATIONAL STORM SUMMARY

 

JULY 2011

 

1^st-9^th…In the Southwest, a plume of moisture associated with the remnants of Tropical Storm Arlene moved northward from Mexico on Monday. While rain persisted across most of Mexico, the system also created scattered showers from southern California and Arizona to Utah and Wyoming. In the East, a low pressure system that hovered over eastern Canada pushed a frontal boundary over the Great Lakes region. The system stretched from the Northeast, over New England, down the Ohio River Valley, and into the Midwest. It kicked up scattered showers and thunderstorms, but severe storms have not yet developed. Heaviest rainfall developed ahead of the front, over the Tennessee River Valley. A mid-day total of 1.30 inches was reported in Bentonville, Arkansas, while Glasgow, Kentucky saw a mid-day total of 1.23 inches of rain. In the Plains, flooding remained a concern in the North. Repeated rain showers have allowed for rivers to remain swollen across the Missouri River and surrounding tributaries.

The East Coast and Central U.S. saw multiple areas of wet weather on Wednesday, while the West Coast and Great Lakes saw mostly sunny skies. Low pressure over Quebec pushed a cold front into New York triggering heavy showers and thunderstorms. This system also brought moderate rainfall to most of Maine. Severe thunderstorm warnings are in effect for most of the Northeast. However, high pressure over the Great Lakes contributed to sunny and mild conditions. To the south, ample moisture pushed onshore kicked up strong storms across the Mid-Atlantic, Tennessee Valley, and Southeastern US. Strong winds have been reported in Boones, Virginia, which contributed to trees blown down. In addition, a tropical wave positioned over Cuba brought heavy showers to southern Florida. These storms are contributing to rainfall from a fifth of an inch to 0.8 inches. To the west, a low pressure system moved into the Northern Plains contributing to heavy downpours and strong winds extending into Colorado. 40 to 50 mph winds have been reported in Hermosa, South Dakota with the highest midday rainfall total in Buffalo, South Dakota at 1.51 inches. At the same time, low pressure located over Kansas brought moderate rainfall across the Central Plains.

The Eastern U.S. saw periods of heavy rain on Friday, as a front stalled over the East Coast. The system moved over the Eastern Valleys and into the Eastern Seaboard. The warm and humid air ahead of this system allowed for scattered showers and thunderstorms to develop from the Northeast to the Mid-Atlantic states. Some of these storms turned severe with heavy downpours and strong winds. Rainfall totals ranged around 2 inches, with up to 2.38 inches reported at Fort Eustis, Virginia. These heavy rain showers allowed for flooding to remain of concern across the eastern Valleys. Meanwhile in the South, a low pressure system over the eastern Gulf of Mexico pushed over the Southeast. Heaviest rainfall was reported in St. Petersburg, Florida, with a mid-day total of 2.81 inches. The system had a low, 10 percent, chance of tropical storm formation, but managed to create some more heavy downpours associated with strong storms over Florida and the Bahamas.

 

A low pressure system in western Canada pushed a trough of low pressure off the Northern Rockies and into the Northern Plains early on Friday. In the Southwest, monsoon moisture allowed for a few more thunderstorms to pop up across the deserts. Flash flooding threatened northern Arizona, after heavy downpours developed.

The eastern U.S. saw multiple areas of active weather on Wednesday. A storm system moved off the Rockies into the Northern Plains and contributed to widespread showers and thunderstorms from Nebraska to Minnesota. Rain from this system has brought totals between a quarter of an inch to 2 inches with the highest rainfall total at 4.45 inches in Winfield, Kansas. To the East, low pressure systems have pushed a frontal boundary through the Ohio Valley, Mid-Atlantic, and Central Plains triggering heavy showers and thunderstorms from Oklahoma to Pennsylvania.

 

17^th-23^rd…Heavy rain persisted along the Gulf, and storms developed in the North on Monday. In the East, a cold front draped along the Northern US, stretched from the Northeast, over New England, and into the Great Lakes. Scattered showers and thunderstorms developed along this frontal boundary, some of which have turned severe with large hail and strong winds. Golf ball size hail was reported in Arcadia, Wisconsin, while multiple trees and power lines were blown down across Michigan and Pennsylvania.  In the South, a low pressure system developed over the Gulf of Mexico and brought periods of heavy rains and strong storms to the surrounding shores. Salt Point, Louisiana reported a mid-day total of 1.97 inches of rain and Cocoa Beach, Florida reported 1.67 inches of rain.

A cold front draped across the Great Lakes and U.S.-Canadian border on Friday. This kicked up scattered showers and thunderstorms, some of which have turned severe. Numerous trees and power lines have blown down from strong winds across northern Indiana. Periods of heavy rainfall have developed associated with these thunderstorms. A mid-day total of 3.00 inches was reported in Waukegan, Illinois.

The nation saw plenty areas of active weather on Friday, while the West Coast and Pacific Northwest saw mostly sunny skies. A low pressure system spinning over Quebec pushed a frontal boundary southward through the Northern U.S. The front extended from the Northeast to the Central Plains and triggered showers and thunderstorms. Rainfall totals associated with these storms ranged from a half of an inch to over two inches, with the highest mid-day rainfall total reported in Lamoni, Iowa at 2.18 inches.

To the south, Tropical Storm Don approached the southeastern coast of Texas and brought heavy showers and strong winds to the region. The rotation of this system has pushed warm, moist air from the Gulf of Mexico onshore, which triggered scattered showers across the South and Tennessee Valley. Wind gusts associated with these storms ranged from 30 to 50 mph. Meanwhile, a ridge of high pressure over Florida continued to bring hot and humid temperatures to most of the Eastern US. Temperatures reached over 100 degrees, with heat indices between 110 and 120 degrees.

 

Jim G. Munley, jr.
http://www.jimmunleywx.com