Valid Saturday November 28, 2015 to Wednesday December 09, 2015
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EST November 25 2015Synopsis
: At the start of the period,
surface low pressure over the southern Plains will move slowly
east/northeastward to the Mississippi and Tennessee Valleys. Arctic high
pressure is expected over the western and central portions of the lower 48
states through the end of November. Surface low pressure near the Aleutians is
anticipated to move to the northern Gulf of Alaska. Hazards
Detailed Summary For Saturday
November 28 - Wednesday December 02:
- Heavy rain for parts of the southern Plains, Lower and Middle
Mississippi Valleys, and Tennessee and Ohio Valleys, Sat, Nov 28.
- Freezing rain and sleet for parts of the central and southern High Plains,
Sat, Nov 28.
- Heavy precipitation for parts of the South Coast of Alaska and the Alaska
Panhandle, Sat-Sun, Nov 28-29.
- Much below-normal temperatures for parts of the northern Intermountain
west, central Great Basin, and northern and central Rockies, Sat-Mon, Nov 28-30.
- River flooding likely or possible over parts of the central and southern
Plains, Mississippi Valley, and southern Great Lakes.
- Severe drought in the far western CONUS and Puerto Rico.
Low pressure and its associated
frontal system over the southern Plains/Middle Mississippi Valley are expected
to act as a focusing mechanism for precipitation. Heavy rain (in excess of 2
inches in 24 hours) is anticipated for parts of the southern Plains, Lower and
Middle Mississippi Valleys, and Tennessee and Ohio Valleys Nov 28. Behind the
front, a cold air mass will surge southward along the Front Range into the
southern High Plains and eastward toward the Great Lakes. hazardous wintry
precipitation is forecast for parts of the central and southern High Plains
Saturday. At this time, the most hazardous weather is expected in the form of
freezing rain and sleet, centered on the Texas panhandle and western Oklahoma.
North and west of the depicted hazard, some accumulating snow is likely, but
amounts are not expected to reach hazardous criteria. Wintry precipitation may
propagate northeastward of the depicted freezing rain/sleet hazard for Saturday
towards the Middle Mississippi Valleys and Great Lakes on Sunday, but model
uncertainty precludes expanding the hazard area at the current time.
The area of arctic high pressure expected over the western and central
CONUS leads to much below-normal temperatures for parts of the northern
Intermountain west, central Great Basin, and northern and central Rockies Nov
28-30. Minimum temperatures of 12-20 degrees F below normal are forecast for
the central and northern parts of the depicted hazard region.
The combination of snow melt and additional precipitation prior and during
the period leads to likely or possible river flooding over parts of the central
and southern Plains, Mississippi Valley, and southern Great Lakes.
Very active weather is forecast for southern Alaska during the period, and
the latest guidance suggests that a heavy precipitation hazard is prudent for
parts of the southeastern coast and Alaska Panhandle. Liquid amounts in excess
of 4 inches in 48 hours are likely within the depicted hazard. Snowfall in
excess of 8 inches in 24 hours is possible at higher elevations. For Thursday
December 03 - Wednesday December 09:
During week 2, an upper-level ridge
is anticipated over the western CONUS, while a weak trough is expected over the
south-central and east-central parts of the nation. Model run to run
consistency is relatively poor so no hazard shapes can be reliably be specified
at the current time.
The most recent U.S. drought monitor, released on November 19, indicates a
slight decrease in the coverage of severe to exceptional drought (D2 to D4),
from 15.24 to 14.88.
Forecaster: Randy Schechter
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Please consult local NWS Forecast Offices for short range forecasts and region-specific information.