Friday, October 31, 2014

Desert Streams

Desert streams flow only during infrequent but intense rainstorms, and when they do, only parts of the channel contain water, making the flow irregular and erratic. One rainstorm may erode sediment grains in one section of the channel, while another storm moves sediment in a different area.
"Given this localized sediment movement during rainstorms, one might expect desert channels to contain mounds of sediment that undulate down the stream course reflecting the irregular flow, but they don't," Singer said. "The water produced in the channel only flows partially down the stream and then stops because it seeps into the riverbed, and there's not enough water from upstream to replace it, so it just disappears."
Because desert river channels do not feature the river bars, pools or riffles common in perennial streams, they decline in elevation downstream very smoothly. According to the researchers' findings, feedback between two variables -- complex water and sediment movements -- shape such basins.

Snow in Tokyo Twice

Tokyo averages only about 4 inches of snow each year, roughly on par with Charlotte, N.C. 
In February, two snow events blanketed one of the world's most populous cities with significant snow in less than a week.
By the evening of Feb. 8, 11 inches of snow blanketed central Tokyo. According to Fuji TV, it was the heaviest snow in 45 years for Tokyo and in 60 years for the city of Kumagaya, northwest of Tokyo. Digital meteorologist Nick Wiltgen (Twitter) says the all-time calendar-day snow record was tied in Kumagaya (43 cm, or 16.9 inches).

Election Day Forecast: Rain May Factor Into Turnout in Central US

While rain could deter voter turnout on Election Day in part of the Central states and the Northwest, dry weather is in store in the East and the balance of the West.
Rain is forecast to fall on areas from Texas to the lower Great Lakes on Election Day.
The rain could affect the major cities of Houston and Dallas to Oklahoma City, St. Louis, Indianapolis, Detroit, Cincinnati, Cleveland, Little Rock, Arkansas and Buffalo, New York. Rain may be close to Chicago as well.

Snow to Plaster Appalachians, New England as Cold Arrives

A storm riding a blast of cold air will unleash heavy snow on the central and southern Appalachians Saturday and will turn toward part of New England by Sunday.

After bringing some of the first snowflakes of the season to areas from Detroit to Cleveland and Pittsburgh on Halloween evening, the storm will dive southward on Saturday.
Accumulating snow is in store for the mountains from southwestern Pennsylvania to northern Georgia.
The heaviest snow will fall in the area from western Maryland and West Virginia to western North Carolina and eastern Tennessee.

Thursday, October 30, 2014

Halloween, Weekend Storm to Bring First Flakes For Some in New England, Great Lakes, Appalachians

Winter storm watches are posted for parts of the Appalachians and snow advisories are in effect in the Great Lakes as the season's first snow targets those areas from Halloween into the weekend.

Given the expected intensity of a southward plunge of the jet stream and the magnitude and depth of cold air pulled with it, we're not simply talking about chilly rain showers, but also accumulating snow for some as well as the first flakes of the season for others.

Also, with low pressure intensifying off the Eastern seaboard this weekend, the combination of strong winds and wet snow accumulations may lead to some power outages and downed trees/tree limbs in parts of the Appalachians and northern New England.
Persistent strong winds off Lakes Superior and Michigan will also whip up some impressive waves along each lake's south shore. Lakeshore flood advisories have been posted, including in the lakefronts of Chicago and Marquette, Mich
Even without any snow, it will be chilly and raw, with highs in much of the Great Lakes and Northeast holding in the 40s, or even 30s in some spots.

Wednesday, October 29, 2014

ropical Storm Hanna Forms Near Nicaragua

The 2014 Atlantic hurricane season kicked out another surprise, as Tropical Storm Hanna formed Monday morning off the coast of Nicaragua just six hours after NHC gave the system a 10% chance of development in their 2 am EDT Tropical Weather Outlook. Surface winds measured overnight by the ASCAT satellite showed sustained winds of 40 mph occurring off the northeast coast of Nicaragua, and visible satellite images just after sunrise on Monday morning confirmed the presence of a low-level surface circulation, prompting NHC to begin issuing tropical storm advisories. Hanna will be a short-lived storm. With a motion west-southwest at 7 mph, the center of Hanna will be over land on Monday afternoon, and passage over land should make the storm dissipate by Tuesday afternoon.

95L No Big Deal; 100 Feared Dead, 300 Missing in Sri Lanka Landslide

An area of disturbed weather (95L) associated with a tropical wave interacting with an upper level trough of low pressure is a few hundred miles northeast of the northern Lesser Antilles Islands, and is headed northwestward to west-northwestward at 10 to 15 mph. Satellite loops show that 95L has a modest amount of spin and heavy thunderstorm activity, but high wind shear of 25 - 30 knots is keeping the thunderstorms disorganized. Water vapor satellite images show that 95L has dry air to its west that is likely interfering with development.