Valid Monday January 26, 2015 to Friday February 06, 2015
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EST January 23 2015Synopsis
: A surface low moving across the
Ohio Valley and central Appalachians is forecast to reach the mid-Atlantic
coast by the start of the Hazards Outlook period. High pressure is predicted to
follow in the wake of this system over the eastern half of the contiguous U.S.
A cold front is then expected to sink southward and eastward out of Canada
across the central and eastern states towards the middle of the period. West of
the Continental Divide, high pressure is anticipated to generally bring fair
weather. A broad area of surface low pressure is forecast to pass south of the
Aleutians, and slowly track into the central and southern Gulf of Alaska.
Summary For Monday January 26 - Friday January
- Marginally heavy snow is possible across the
central Appalachians and mid-Atlantic, Mon, Jan 26.
- High winds for the Northeast coast, Tue, Jan 27.
- High winds for the eastern North Slope of Alaska, Mon-Tue, Jan 26-27.
- Much below-normal temperatures for New England, New York, and much of the
mid-Atlantic, Tue-Wed, Jan 27-28.
- Much below-normal temperatures for south-central and southeastern Alaska,
Mon-Tue, Jan 26-27.
- Severe drought for the Central and Southern Great Plains, Southwest, Great
Basin, California, and the Pacific Northwest.
A clipper system is expected to move from the Ohio Valley and central
Appalachians to the mid-Atlantic coast by Monday. Generally 2-4 inches of snow
is predicted to accompany this clipper as it moves across the higher terrain of
the central Appalachians to Chesapeake Bay. The forecast for the Delmarva
Peninsula is less certain, as several computer models anticipate the clipper
system may weaken across western Virginia and redevelop a significant distance
off the Eastern Seaboard, thereby producing a relative minimum in expected
precipitation amounts across the Delmarva Peninsula. Though the anticipated
snowfall amounts are marginally heavy, they are more than enough to snarl
commuter traffic in the Baltimore and Washington, D.C. areas on Monday morning.
Once the storm moves off the mid-Atlantic coast, it is then forecast to
deepen and track northeastward over the western Atlantic. High winds (sustained
speeds may reach 30 knots or greater) are anticipated along the Northeast U.S.
coast on the rear side of the strengthening storm. Colder air is also expected
to move in behind the storm, with much below-normal temperatures (generally
12-16 degrees below-normal) anticipated for New England, New York, and much of
the mid-Atlantic region.
Surface high pressure is anticipated to build southward across Alaska
during the first few days of this period. With high pressure initially centered
over the Chukchi Sea, northwest flow is expected to impinge on the northern
flank of the Brooks Range, and may result in blizzard conditions for eastern
portions of the North Slope. This is a fairly common occurrence from near
Prudhoe Bay and Deadhorse eastward, including the Kaktovik area. During this
same period, much below-normal temperatures are also predicted for
south-central and southeastern Alaska. Daily minimum temperatures may reach 30
degrees F below normal, while maximum temperatures may reach 40 degrees F below
normal. For Saturday January 31 - Friday
A very amplified 500-hPa circulation pattern is predicted
during Week 2, with a ridge over western North America, and a trough over
eastern North America. The GEFS Reforecast Tool indicates a 30 to 50 percent
chance of minimum temperatures reaching the lower 15th percentile compared to
climatology for parts of the northeastern quarter of the CONUS for much of the
week-2 period. Therefore, a slight risk of much below-normal minimum
temperatures has been identified for much of the central and eastern Great
Lakes, Ohio Valley, mid- Atlantic, and Northeast from January 31 to February 4,
and a moderate risk for a slightly smaller spatial area, valid for the same
The most recent U.S. drought monitor, released on January 22, 2015
indicates a very slight increase in the areal coverage of severe to exceptional
drought (D2 to D4) from 16.65 to 16.97 percent across the continental
Forecaster: Anthony Artusa
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.