Valid Thursday October 27, 2016 to Monday November 07, 2016
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT October 24 2016Synopsis
: At the start of the period, surface
low pressure forecast over the Ohio Valley is expected to move off the New
England coast as high pressure moves from the central U.S. to the southeastern
part of the nation. A series of surface low pressure systems are forecast to
impact the west coast of the U.S. Multiple areas of strong surface low pressure
are expected to move from the Bering Sea towards northwestern Mainland Alaska.
During week-2, air of Pacific origin is anticipated to dominate the lower 48
states with above-normal temperatures expected. An unsettled weather pattern is
likely to persist over the Pacific Northwest and Alaska. Hazards
Summary For Thursday October 27 - Monday October
- Heavy rain for parts of the northeast, Thu-Fri, Oct 27-28.
- High winds for portions of coastal New Hampshire and Maine, Fri, Oct 28.
- Periods of heavy rain for parts of Northern California and southwestern
Oregon, Thu-Sun, Oct 27-30.
- Periods of high winds across portions of western mainland Alaska and the
Aleutians, Thu-Mon, Oct 27-Oct 31.
- Periods of significant waves for parts of the Aleutians and Alaska
Peninsula, Thu-Mon, Oct 27-31.
- Significant waves for parts of western mainland Alaska, Sat, Oct 29.
- Flooding occurring or imminent across a small portion of northeastern South
- Severe Drought in the Central Plains, the Mid-Atlantic, the Lower
Mississippi Valley, the Central Great Basin, the Northern Plains, the Tennessee
Valley, the Great Lakes, Hawaii, the Northern Great Basin, the Northeast,
California, the Southern Appalachians, the Southeast, the Central Appalachians,
the Southern Plains, and the Southwest.
Surface low pressure forecast over the Ohio Valley Oct 27 is expected
to move off the New England coast by Oct 28. Heavy rain (in excess of 1 inch in
24 hours) is anticipated for parts of the northeast Oct 27-28. In addition,
high winds (speeds in excess of 30 knots) are expected for portions of coastal
New Hampshire and Maine Oct 28. Snowfall is possible over the highest
elevations of interior New England but amounts are not currently expected to
reach hazardous criteria.
A series of low pressure systems over the eastern Pacific are forecast to
lead to unsettled weather for portions of the west coast. Periods of heavy rain
(in excess of 1 inch over 24 hours) are anticipated for parts of Northern
California and southwestern Oregon Oct 27-30. Local amounts exceeding 5 inches
over the 4-day period are possible over portions of Northern California and
extreme southwestern Oregon. Snow levels are forecast to be high with only the
highest peaks expected to see accumulating snowfall.
High pressure and warm temperatures are likely to build in over the Great
Plains. Daily high temperatures are likely to be 16-20 degrees F above normal,
but high temperatures are not expected to be threatening to life or property,
so no hazard is depicted.
Over the Bering Sea and Gulf of Alaska, a series of deep troughs are
expected during most of the period. At the same time, areas of surface low
pressure are anticipated over these regions. This is expected to lead to
periods of significant waves (wave heights in excess of 20 feet) Oct 27-31 for
parts of the Aleutians and the Alaska Peninsula. Significant waves are also
anticipated for portions of southwestern Mainland Alaska Oct 29. Periods of
high winds (winds in excess of 40 knots) are expected Oct 27-31 for parts of
western mainland Alaska and the Aleutians. Coastal flooding due to ocean
encroachment along the western coast of Alaska is also possible. The risk to
life and property with this predicted system is high.
Hurricane Seymour currently south of Baja California is expected to weaken
as is approaches the Peninsula Oct 29. Moisture associated with this system may
get drawn northward by the trough forecast over the eastern Pacific and enhance
precipitation amounts along the west coast. For Tuesday November 01 - Monday
Air masses of Pacific origin are forecast to dominate the
CONUS. No large negative temperature anomalies are anticipated during the
period. A deep trough over the eastern Pacific is expected to maintain
unsettled conditions for parts of Alaska and the Pacific Northwest but no
specific hazards can currently be identified due to timing differences among
recent model solutions.
Severe, or greater intensity, drought increased slightly in coverage across
the CONUS during the past week. Severe drought is now covering 9.66% of the
CONUS, up from 8.68% the prior week.
Click here to see a display of the GFS Ensemble Forecasts
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.