NATIONAL WEATHER SUMMARY

 

MARCH 2011

 

1st-5^th…More wet weather activity developed in the Pacific Northwest and the northern half of California Wednesday as a trough of low pressure remained anchored off the Pacific Northwest Coast. Significant moisture coupled with a cold front that pushed across the Coast this morning and brought periods of rain and moderate high elevation snow showers to areas from western Washington to parts of central California. In addition to rain and snow, strong winds accompanied the disturbance across the region with gusts up to 45 mph in the lower elevations ad gusts up to 55 mph in the higher, wind prone elevations. This lead to periods of blowing and drifting snow with reduced visibilities in the northern Sierra Nevadas and the central to northern Cascades. Wind Advisories remained in effect for the central valley of California through the afternoon. Elsewhere in the West, a few pockets of snow showers developed in part of the Intermountain West. In the East, the passing of a cold front brought scattered snow showers, flurries, and rain to parts of New York and Pennsylvania through Massachusetts. A snow squall brought brief heavy snow rates and light snow accumulations of 1 to 3 inches to areas of northern Maine. To the south, cooler temperatures and increased cloud cover lingered over southern Florida as a cold front dropped southeastward. Widely dispersed showers continued in the nearby Atlantic waters through the afternoon. Only a few showers reached the coastal zone. Elsewhere, high pressure prevailed across the Midwest and Plains with generally settled weather conditions.

The most active weather in the country was due to a storm that began the day over the Southern Plains before developing significantly while moving northeastward as the day progressed. As it moved into the eastern third of the country, it began to pick up a fair amount of moisture that produced widespread rain along with areas of snow in the Ohio Valley and Upper Midwest. This precipitation landed on ground that was either close to or already saturated, thus flooding was a concern for much of the area. Flood Watches and Warnings were posted from Tennessee through western New York. Parts of the Lower Mississippi Valley was also under Flood Watches in anticipation of heavy flow upstream of the Mississippi River. Some areas of snow did develop in Kansas and Nebraska, but this precipitation was not widespread or heavy in nature. A high pressure system kept much of the West dry, but an approaching Pacific storm was set to renewing rain and high elevation snow over the weekend, especially along the West Coast. The Northeast rose into the 20s, 30s, and 40s, while the Southeast saw temperatures in the 60s and 70s. The Northern Plains rose into the 0s and 10s, while the Northwest saw temperatures in the 30s and 40s.

A strong storm moved through the Ohio Valley and was on the verge of moving into the Northeast in the late Saturday afternoon and evening. The cold front associated with the storm stretched all the way to the Gulf Coast and ushered a tremendous amount of moisture into the eastern third of the country. This moisture, in turn, translated to widespread moderate to heavy rain east of the Mississippi Valley. This precipitation was particularly strong in the afternoon, when strong thunderstorms formed from Louisiana through the Tennessee Valley. Some of these thunderstorms were severe enough to produce reports of tornadoes and damaging in Louisiana. One of these tornadoes injured 3 people and was 25 yards wide.

Farther to the north, cooler rain fell in the Ohio Valley, while developed in Michigan and a few areas of New England as the storm approached the area. The rain was intense enough to instigate Flood Watches and Warnings throughout the Ohio Valley and Tennessee Valley as some areas were bound to experience flooding. The West was pleasant in comparison in advance of a Pacific storm that will renew rain and high elevation snow on Sunday. The Northeast rose into the 30s, 40s, and 50s, while the Southeast saw temperatures in the 60s and 70s. The Northern Plains rose into the 10s, and 20s, while the Southwest saw temperatures in the 60s and 70s.

 

6^th-12^thWet weather diminished across the West Coast, as a system moved eastward into the Rockies on Monday. The system that brought heavy rain to the Pacific Northwest and northern California has continued kicking up showers as it swept through the Great Basin and Central Rockies. This system pulled warm air in from the south, and allowed for snow levels to remain high across Colorado. Snow levels during the day were up to 8,000 feet, which allowed for a messy combination of rain and snow to develop across valley floors. At highest levels, snowfall accumulation ranged from 1 to 3 inches. Heavy snow hit Utah, with snowfall rates up to 2 inches per hour in Cedar City, Utah. The Great Basin sat under the colder sector of the system, which allowed for snow levels to drop to about 5,000 feet. A trough of low pressure led this system into the Plains, creating widespread scattered snow showers across the Northern Plains, and rain showers across the Central Plains. Mid-day snowfall totals ranged from 2 to 4 inches across Nebraska, while rainfall totals remained light to the south. Further east, a strong low pressure system pushed a cold front offshore of the East Coast. This system lingered over the extreme Northeast and kicked up periods of heavy snow showers. Snowfall accumulation ranged from 2 to 4 inches from upstate New York to Maine. Heavy rain caused flooding problems just to the south, across Connecticut and Massachusetts, with rainfall totals around 1.50 inches.

Gloomy skies covered the Eastern U.S. Wednesday afternoon as a major storm system from the Mid-Mississippi Valley became positioned over northern Illinois. The system drew moisture from the Gulf of Mexico across the central Gulf Coast into the Southeast, Eastern Valleys, Great Lakes, and Appalachians. This moisture aided in producing showers and thunderstorms from the central Gulf Coast through the Appalachians and Ohio Valley. Storms near the central Gulf Coast turned severe with tornadoes, hail reports, and numerous high wind reports. A slight risk for severe weather activity remained across portions of the eastern Gulf Coast region during the afternoon. Moist flow from the Gulf also aided in producing rain, snow, and pockets of freezing rain in Wisconsin, Michigan, and the Lower Great Lakes. In the West, a cold front pushed across the Pacific Northwest coast with wet and windy weather conditions. The front brought a mix of rain and mountain snow along with strong winds to the coast and valleys. South wind of up to 40 to 50 mph with gusts to 70 mph affected the beach and headlands from Florence, Oregon to near Raymond, Washington, while south wind of up to 35 mph with gusts to 55 mph affected the nearby coastal communities of these areas. A High Wind Warning remained in effect for the beaches and headlands of south Washington and the north and central Oregon coasts through the afternoon.

Wet and snowy weather persisted across the East on Thursday, while wet weather returned to the West. A strong low pressure system and associated cold front that brought severe weather to the Southeast on Wednesday has made its way eastward. The front extended from New England, down the East Coast, and wrapped around westward over Florida into the Gulf of Mexico. The front brought periods of heavy rain with a mid-day total of 2.25 inches reported in Baltimore, Maryland, while Middletown, Pennsylvania reported 1.59 inches of rain. Strong winds associated with severe thunderstorms produced tornadoes across southeastern Florida. A brief tornado touchdown was observed in a parking lot at Fort Lauderdale Airport, Florida and a funnel cloud touched down near Highway 1 in Key Biscayne, Florida. While rain covered most of the East Coast, near freezing temperatures of the extreme Northeast allowed for snow showers to develop. Snowfall accumulation ranged from 1 to 3 inches across Maine, while Vermont and New Hampshire saw a messy combination of frozen rain, ice, and snow. Out West, another low pressure system and associated cold front moved onshore from the Pacific Ocean. This produced rain showers over the Pacific Northwest, which extended into northern California. A mid-day total of 0.63 inches was reported in Crescent City, California.

Flooding remained a threat from the Northeast to the Upper Mid-Atlantic states on Friday as heavy rain persisted across the region. A strong low pressure system that brought heavy rain and snow to the Northeast on Thursday has slowly moved northeastward and into Quebec. While the strong cold front associated with this system has moved offshore and pulled showers and thunderstorms with it, counter-clock wise flow around the system continued to push ample moisture over the Northeast and New England from the Atlantic Ocean. Additionally, flow from the north on the back side of this system pulled moisture into the Lower Great Lakes and produced scattered snow showers over Ohio, Pennsylvania, and western New York. Up to 5 inches of lake effect snow developed along the southern shores of the Lower Great Lakes, while snowfall accumulation remained around an inch elsewhere. The higher elevations of the Appalachians saw up to 3 inches of new snow. Rainfall totals reached up to 1.23 inches in White Plains, New York, while most of the New England coast saw between a half of an inch and an inch of rain. Thus, the entire region remained under flooding warnings and watches. Behind this system, another low pressure system developed as it moved off the Northern Rockies and into the Northern Plains. This system skirted across the US and Canadian border, kicking up scattered snow showers over the Dakotas. The region saw 2 to 4 inches of snow. Strong winds accompanied this system with wind gusts up to 56 mph reported at Dickinson, North Dakota. A blizzard warning has been issued across most of North Dakota, so please take caution when driving through these areas.

13^th-19^th…The central U.S. saw active weather on Monday, with heavy rain in the South and periods of heavy snow in the Midwest. A strong low pressure system moved from the Southern Plains and up the Ohio River Valley. Flow around the system created a warm front that stretched into the Northeast, while a cold front extended southward to the Gulf of Mexico. Heavy rain and strong winds developed along the cold front as it quickly tracked over eastern Texas and into the Lower Mississippi River Valley. Houston Hull, Texas reported a mid-day total of 1.32 inches of rain, while wind gusts around the region reached up to 25 mph. To the north, the warm front that extended from Missouri and stretched over Kentucky and into the Virginias also triggered heavy rain. The greatest rainfall total from this front was reported in Carbondale, Illinois, with a mid-day total of 1.63 inches. Just to the north of this warm front, cold temperatures allowed for periods of heavy snow to develop. Summerfield, Illinois saw snowfall rates up to a half of an inch per hour, with mid-day totals in western Illinois and northern Missouri between 2 and 5 inches of new snow. Meanwhile, out West, a low pressure system pushed a cold front over the West Coast in the early morning hours, which reached into the Northern Rockies and Great Basin by Monday afternoon. The heaviest rain showers hit Sacramento, California, with a mid-day total of 1.51 inches. Snowfall totals range from 10 to 16 inches across the high elevations of the Northern Sierras.

Wet weather continued to pound the Northwest Wednesday as cool, moist onshore flow from the Pacific Ocean streamed across the region. This abundance of moisture combined with disturbances trekking across the region to produce areas of rain, mountain snow, and thunderstorms from the Pacific Northwest and northern California through parts of the Northern and Central Rockies. Winter Weather Advisories remained in effect for the Cascades and the Sierra Nevadas through the afternoon. An additional 2 to 6 inches of snow were possible in the Cascades through Meanwhile, Winter Weather Advisories and Winter Storm Warnings remained in effect for the Northern and Central Rockies as a significant weather disturbance affected these areas during the morning and afternoon. Snow was slow to accumulate across the mountains this morning. In the East, mostly cloudy skies covered areas from the eastern Ohio and Tennessee Valleys through the much of the East Coast as a cold front became positioned along the East Coast and a trough of low pressure moved through the Upper Mid-Atlantic. Most of the rainfall that developed ahead of this cold front in the Mid-Atlantic pushed offshore into the western Atlantic Ocean during the afternoon. On the backside of this system, colder air spread into the Northeast, Lower Great Lakes, and the eastern Ohio Valley and lead to chilly afternoon temperatures. Meanwhile, an area of weak low pressure associated with this system moved northeastward along the Maine coastline through the afternoon. Light rain and snow continued in northern New England. This combination of rain and wet snow during the morning and afternoon resulted in slippery driving conditions, especially across the higher elevations.

The West Coast saw a wet, snowy, and windy day on Friday as a strong front moved onshore. A strong low pressure system that strengthened off the West Coast pushed an intense cold front onshore. This front moved over the Pacific Northwest and stretched through northern California. As this system swept southeastward throughout the day, it triggered periods of heavy rain and strong winds, with heavy snow in the Coastal Range, the Cascades, and into the northern Sierras by afternoon. Snowfall totals along the Coastal Range varied from 6 to 11 inches above the 2,000 to 3,000 foot level. Only 1 to 2 inches were reported in the Northern Sierras to the valley floors, while the Cascades saw 1 to 3 inches of snow above 4,500 feet. Low level rainfall was heavy at times, especially across northern California. The greatest rainfall across the nation was reported in Ukiah, California, with a mid-day total of 1.14 inches. Most of northern California saw between 0.25 and 0.75 inches of rain. Strong winds accompanied this front, with wind gusts up to 41 mph, reported in Santa Rosa, California, while San Jose, California saw gusts up to 48 mph. A wind advisory has been issued along the coastal regions of California. Elsewhere, a ridge of high pressure brought warm Spring weather to the rest of the nation on Friday. Record breaking high temperatures were reported across the Mid-Atlantic states as high temperatures skyrocketed into the upper 70s and lower 80s. Meanwhile, a mild cold front over the Ohio River Valley and Midwest triggered scattered showers and thunderstorms. Severe storms have not developed over these areas.

 

20^th-26^th…Two systems brought wet weather to the nation on Monday. A low pressure system in the West continued to advance eastward, over the West Coast and into the Great Basin and Intermountain West. This system triggered more heavy snow as it made its way through Nevada, Utah, and into Idaho. Snow levels were at the valley floors across most of these areas, with snowfall accumulation between 3 to 5 inches. Meanwhile, behind this system, scattered rain showers persisted along the West Coast, from Washington to southern California. Heaviest rain was reported in Campo, California with a mid-day total of 0.94 inches. This system also continued to push a cold front southward into the Southwest, where it kicked up more heavy rain with high elevation snow showers across northern Arizona. Snowfall accumulation ranged from 3 to 9 inches around Flagstaff, Arizona, while 0.48 inches of rain was reported at Kingman, Arizona. The other weather feature bringing wet weather to the nation was a low pressure system in the East that made its way over the Great Lakes and into the Northeast. It pushed a warm front through the Northeast and pulled a cold front through the Midwest. As temperatures remained well above freezing in the 40s and 50s, rain showers developed along the frontal boundaries. Mid-day rainfall totals ranged from 0.44 inches in Rochester, New York to 0.69 inches in Williamsport, Pennsylvania.

In between these systems, mild weather prevailed as a mild ridge built into the Plains. However, a few scattered showers and thunderstorms developed across the Central Plains, but severe storms have not yet developed.

More active weather developed in the Eastern Valleys Wednesday, while another Pacific storm soaked California. In the East, the strong storm system that produced severe weather in the Mid-Mississippi Valley moved into the Ohio Valley today. Modest moist flow ahead of an associated energetic cold front that extended from eastern Illinois to southwestern Texas triggered areas of rain and thunderstorms from the southern regions of Indiana and Ohio through parts of Tennessee. Meanwhile, to the north, a warm front associated with this storm system lifted through the northern Ohio Valley and triggered snow showers from eastern Wisconsin through southern New England. Bands of snow continued to diminish southern Minnesota through central Wisconsin through the afternoon.

 

In the West, another Pacific front moved across the California coast this afternoon. Strong, moist, onshore flow accompanied this front and streamed across the coastal areas and the Sierra Nevadas. This translated into more rain and mountain snow in the already saturated areas of northern and central California. Risks of runoff lead to possible flooding of roads and low lying areas as well as some rises in creeks, streams and rivers in the central and northern valleys.

 

27^th-31^st…The Southeast saw another wet day on Monday, while scattered showers popped up across the Plains and Rocky Mountains. A low pressure system moved off the Rockies and into the Plains, while a cold air mass lingered over the Central U.S. Additionally, flow around the low pulled moisture northward from the Gulf of Mexico. This combination of weather features allowed for scattered snow showers to develop from Nebraska to North Dakota. Flow around this system pushed moisture well into the Northern and Central Rockies. Mountain snow developed across southern Idaho, northern Utah, and western Colorado. Snowfall accumulation ranged from 2 to 10 inches in Colorado, up to 7 inches in Utah, and from 3 to 6 inches in Idaho. The Northern Plains saw near 2 inches of new snow. Further west, a ridge of high pressure built northward from the Southwest. This ridge brought sunny skies and dry conditions to California, a much needed break from the rain and high elevation snow. The Northwest, however, saw more cloudy skies with scattered showers as a trough approached from the Gulf of Alaska. In the South, a low pressure system created a strong frontal boundary that kicked up periods of heavy rain and thunderstorms over the Gulf of Mexico. Heaviest rainfall developed over Florida, with mid-day totals up to 2 inches. Brooksville, Florida reported 2.44 inches of rain on Monday. In the Northeast, high pressure dominated over the Great Lakes and New England. This brought dry and sunny conditions with highs ranging from the 40s and 50s.

Cloudy skies covered much of the eastern Valleys, the Mid-Atlantic, and the Southeast Wednesday as a series of frontal disturbances and low pressure moved through the southeastern quadrant of the nation with active weather. Energy associated with these systems combined with rich warm moisture from the Gulf of Mexico to produce numerous bands of rain and thunderstorms from the southern Alabama and the Florida Panhandle through the Mid-Atlantic Coast during the afternoon. Storms in northern and central Florida, southern Georgia, and portions of the South Carolina coast had the potential to turn severe with damaging winds, periods of strong to severe hail, and isolated tornadoes. Thus far, there were 2 strong wind reports from Laurens, Georgia and Jefferson, Louisiana. Strong winds in theses counties led to downed power lines, broken transformers, and power outages. Meanwhile, on the northern edge of this system, cold daytime highs at the freezing mark supported periods of moderate snowfall in Ohio and the Central Appalachians. Behind the activity in the East, a trough of low pressure kicked up a few areas of light rain and light snow showers in Nebraska as it moved through the Midwest. In the West, subtropical moisture accompanied a warm front that became stalled over western Washington this afternoon. This duo brought rain showers and periods of heavy rainfall to the coast and western mountains of the state. Major rainfall created Flood Watches over the area, while warming and rainfall created Avalanche Warnings in the Cascades. Elsewhere, a few patches of precipitation developed in the Northern Intermountain West, while high pressure provided dry and fair weather conditions in California, parts of the Central Great Basin, and the Southwest.

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