Valid Saturday March 07, 2015 to Wednesday March 18, 2015
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EST March 04 2015Synopsis
: Arctic high pressure is expected over
the south-central and eastern U.S. Surface low pressure is expected to move
northeastward across the Great Lakes and north of New England. Return flow
around the rear side of the area of high pressure will gradually draw moisture
northward from the Gulf of Mexico. Surface low pressure is forecast to cross
central Alaska with cold surface high pressure then anticipated to build over
western and northern Alaska. A 2nd area of surface low pressure is expected to
approach the Aleutians. Deep upper-level low pressure is forecast near and
north of the Hawaiian Islands. During week 2, areas of upper-level low
pressure are forecast over the northeast, southern Plains, and Alaska.
Detailed Summary For Saturday March
07 - Wednesday March 11:
- Heavy rain for parts of the Texas and Louisiana
Gulf Coast, Mon-Tue, Mar 9-10.
- High winds for coastal sections of the northeast and northern Mid-Atlantic,
Sat, Mar 7.
- Much below normal temperatures for much of the south-central and eastern
CONUS (except the southeast), Sat-Sun, Mar 7-8.
- Heavy snow for parts of central Alaska near and south of the Brooks Range,
Sat, Mar 7.
- Periods of high winds for parts of western and southern coastal Alaska,
Sat-Wed, Mar 7-11.
- Significant waves for coastal sections of southwestern Alaska, Sat, Mar 7.
- Significant waves for parts of the Aleutians, Mon-Tue, Mar 9-10.
- Much below normal temperatures for parts of central and eastern Alaska,
Mon-Wed, Mar 9-11.
- Flooding possible or likely for parts of Kentucky.
- A slight risk of much below-normal minimum temperatures for much of the
Plains, parts of the Northern Rockies, Great Lakes, Mississippi and Tennessee
Valleys, and southeast, Thu-Mon, Mar 12-16.
- A slight risk of much below normal minimum temperatures for parts of the
Mid-Atlantic and northeast, Fri-Sun, Mar 13-15.
- A slight risk of much below normal minimum temperatures for much of central
and eastern Alaska, Thu-Sat, Mar 12-14.
- A moderate risk of much below normal minimum temperatures for parts of
central eastern Alaska, Thu, Mar 12.
- Periods of heavy rain for Hawaii (especially Maui and the Big Island),
Sat-Tue, Mar 7-11.
- Severe drought for the Central and Southern Great Plains, Southwest, Great
Basin, California, the Pacific Northwest, and Tennessee Valley.
Arctic high pressure dominates much of the
eastern and south-central CONUS which leads to much below normal temperatures
(negative anomalies of 12-24 degrees) spreading eastward across much of the
south-central and eastern CONUS (except the southeast) Mar 7-8. Low pressure is
forecast to move across the northern Great Lakes and north of New England. The
tight pressure gradient between this area of low pressure and the area of
arctic high pressure leads to high winds (in excess of 30 knots) for coastal
sections of the northeast and northern Mid-Atlantic Mar 7. As the arctic high
pressure moves off the east coast, a moist return flow is expected to get
established leading to heavy rain for parts of the Texas and Louisiana Gulf
Coast Mar 9-10. This rainfall is expected to gradually spread north and
eastward, but model uncertainty precludes the specification of additional
hazard shapes at this time.
Antecedent rainfall, along with snow melt and the expectation of additional
precipitation before the start of the period leads to possible or likely river
flooding for parts of Kentucky.
Low pressure and its associated frontal system are expected to move across
central and southern Alaska leading to heavy snow (in excess of 6 inches in 24
hours) for parts of central Alaska near and south of the Brooks Range Mar 7.
High winds (in excess of 30 knots) are anticipated for parts of western and
southern coastal Alaska Mar 7-11 as a 2nd area of low pressure approaches the
Aleutians. In addition, significant waves (in excess of 18 feet) are
anticipated for coastal sections of southwestern Alaska Mar 7, and the
Aleutians Mar 9-10. High pressure building over western and northern Alaska
leads to much below normal temperatures (20-30 degree negative anomalies) for
parts of central and eastern Alaska Mar 9-11.
A 500-hPa trough over the east-central Pacific is predicted near and north
of Hawaii. As a result, several models predict rainfall amounts of 2-5 inches
for the Islands in general, and locally up to a foot of rain is possible in
Maui and the Big Island during this period. For Thursday March 12 -
Wednesday March 18:
There is a slight risk of much below-normal
temperatures for much of the Plains, parts of the Northern Rockies, Great
Lakes, Mississippi and Tennessee Valleys, and southeast Mar 12-16 due to an
area of upper-level low pressure. The expectation of upper-level low pressure
also leads to a slight risk of much below-normal temperatures for parts of the
Mid-Atlantic and northeast Mar 13-15.
Upper-level low pressure leads to a slight risk of much below normal
temperatures for much of central and eastern Alaska Mar 12-14, and a moderate
risk of much below normal temperatures for parts of east-central Alaska Mar 12.
The most recent U.S. drought monitor, released February 26, 2015, indicates
a slight decrease in the areal coverage of severe to exceptional drought (D2 to
D4) in the past week from 16.44 to 16.42 percent across the continental U.S.
Forty percent of California remains designated in the exceptional drought (D4)
category. Although most revisions made to the Monitor this week are fairly
small, the more notable changes include a general 1-category improvement in
Kentucky and western Tennessee, and a 1-category degradation across the central
Gulf Coast area.
Forecaster: Randy Schechter
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Please consult local NWS Forecast Offices for short range forecasts and region-specific information.