Friday, October 21, 2011

[FEMA]

Homeland Security Threat Level: YELLOW (ELEVATED)

Significant National Weather

West
A weak front will produce rain and thunderstorms from the Pacific Northwest to the Northern Rockies. A wintry mix with minor accumulations at higher elevations is possible in the Cascades. Dry conditions can be expected across the remainder of the region.
Midwest
A deep low pressure system will produce moderate to heavy rain and gusty winds across the Ohio Valley and much of the Great Lakes. Rain and wind should slowly become less intense as the low pressure gradually weakens and moves into Canada today. A cold front will produce rain over the Northern Plains.
SouthÂ*
High pressure will bring generally dry conditions throughout the region.
Northeast
Light to moderate showers are forecast from the Appalachians to northern New England. Dry conditions are expected from the northern Mid-Atlantic to southern Maine.

Winter Outlook

The National Oceanic and Atmospheric Administration released their annual Winter Outlook on Thursday Oct. 20.
For the second winter in a row, La Niña will influence weather patterns across the country, but as usual, it’s not the only climate factor at play. The ‘wild card’ is the lesser-known and less predictable Arctic Oscillation that could produce dramatic short-term swings in temperatures this winter.
NOAA expects La Niña, which returned in August, to gradually strengthen and continue through the upcoming winter. It is associated with cooler than normal water temperatures in the tropical Pacific Ocean and influences weather throughout the world.
The Arctic Oscillation is always present and fluctuates between positive and negative phases. The negative phase of the Arctic Oscillation pushes cold air into the U.S. from Canada. The Arctic Oscillation went strongly negative at times the last two winters, causing outbreaks of cold and snowy conditions in the U.S. such as the “Snowmaggedon” storm of 2009. Strong Arctic Oscillation episodes typically last a few weeks and are difficult to predict more than one to two weeks in advance.
With La Niña in place Texas, Oklahoma, New Mexico and parts of surrounding states are unlikely to get enough rain to alleviate the ongoing drought. Texas, the epicenter of the drought, experienced its driest 12-month period on record from Oct. 2010 through Sept. 2011.
Highlights of the U.S. Winter Outlook (December through February) include:

• Pacific Northwest: colder and wetter than average. La Niña often results in below-average temperatures and increased mountain snow in the Pacific Northwest and western Montana during the winter months. This may set the stage for spring flooding in the Missouri River Basin;
• California: colder than average with odds favoring wetter than average conditions in northern California and drier than average conditions in southern California. All of the southern part of the nation are at risk of having above normal wildfire conditions starting this winter and lasting into the spring;
• Northern Plains: colder and wetter than average. Spring flooding could be a concern in parts of this region;
• Southern Plains and Gulf Coast States: warmer and drier than average. This will likely exacerbate drought conditions in these regions;
• Florida and south Atlantic Coast: drier than average, with an equal chance for above-, near-, or below-normal temperatures. Above normal wildfire conditions;
• Ohio and Tennessee Valleys: wetter than average with equal chances for above-, near-, or below-average temperatures. Potential for increased storminess and flooding;
• Northeast and Mid-Atlantic: equal chances for above-, near-, or below-normal temperatures and precipitation. Winter weather for these regions is often driven not by La Niña but by the Arctic Oscillation. If enough cold air and moisture are in place, areas north of the Ohio Valley and into the Northeast could see above-average snow;
• Great Lakes: tilt toward colder and wetter than average;
• Hawaii: Above-average temperatures are favored in the western islands withÂ*equal chances of above-, near-, or below average precipitation. Statewide, the current drought is expected to continue through the winter. Drought recovery is more likely over the windward slopes of the Big Island and Maui;
• Alaska: colder than average over the southern half of the state and the panhandle with below average precipitation in the interior eastern part of the state.

This seasonal outlook does not project where and when snowstorms may hit or provide total seasonal snowfall accumulations. Snow forecasts are dependent upon winter storms, which are generally not predictable more than a week in advance.

Tropical Weather Outlook

Atlantic / Caribbean / Gulf
A broad low pressure area is located over the southwestern Caribbean sea about 150 miles east-southeast of the Honduras-Nicaragua border. Although this large disturbance is showing signs of organization, any further development should be slow to occur due to only marginally favorable upper-level winds and proximity to dry air for the next couple of days. However, environmental conditions are expected to become more conducive for development after a few days. This system has a low chance (20 percent) of becoming a tropical cyclone during the next 48 hours as it drifts southward.
An area of disturbed weather located about 1,000 miles east of the Windward Islands has diminished and upper-level winds are becoming less favorable for development. This system has a low chance (near 0 percent) of becoming a tropical cyclone during the next 48 hours as it moves slowly northward or northwestward. Elsewhere, tropical cyclone formation is not expected during the next 48 hours.
Eastern Pacific
Tropical cyclone formation is not expected during the next 48 hours.
Central Pacific
No tropical cyclone activity is expected through Saturday morning.
Western Pacific
No tropical cyclone activity.

Earthquake Activity

In Texas a magnitude 4.8 earthquake occurred on Oct. 20 at 8:24 a.m. EDT, 47 miles south-southeast of San Antonio and 37 miles northwest of Beeville, Texas, at a reported depth of 1.9 miles. There have been no reports of damage or injury.
Wildfire Update

Thursday, Oct. 20: National Preparedness Level 1. Initial wildland fire attack activity was LIGHT with 24 new fires. There were no new large fires and one large uncontained fire reported. The state affected is Minnesota.
Disaster Declaration Activity

Massachusetts
Effective Oct. 20, Amendment No. 3 to Major Disaster Declaration FEMA-4028-DR for the Commonwealth of Massachusetts dated Sept.3, 2011 is amended to add Barnstable, Bristol, Dukes, Norfolk, and Plymouth Counties for Public Assistance, including direct federal assistance.
Louisiana
Louisianaâs Governor is requesting a Major Disaster Declaration resulting from Tropical Storm Lee during the period of September 1-5, 2011. The Governor is specifically requesting Public Assistance for the parishes of East Feliciana, Jefferson, Lafourche, Plaquemines, St. Bernard, St. Charles, Terrebonne, and West Feliciana and Hazard Mitigation statewide.

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