Valid Monday August 31, 2015 to Friday September 11, 2015
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT August 28 2015Synopsis
: Early in the period Tropical storm
Erika currently southeast of Puerto Rico is expected to strenghten to a
hurricane as it tracks across the Bahamas this weekend. Surface low pressure
over the Gulf of Alaska on Sunday is expected to cause onshore flow over parts
of the Alaska Panhandle and the Pacific Northwest during Sunday and Monday.
Strong northerly flow is expected over western Alaska due to the circulation
around the area of surface low pressure forecast over the Gulf of Alaska.
During week-2, an area of upper-level high pressure is anticipated to develop
over Alaska while upper-level high pressure builds over the central and
east-central portions of the lower 48 states. Areas of upper-level low pressure
are expected to be embedded within this area of upper-level high presure.
Summary For Monday August 31 - Friday September
- Flooding possible for parts of the Upper and
Middle Mississippi Valleys.
- Flooding possible for parts of west-central Florida.
- Heavy rain for parts of the southeast, Mon-Thu, Aug 31-Sep 3.
- High winds for parts of the southeast, Mon-Wed, Aug 31-Sep 2.
- Heavy rain for parts of northwestern Washington state, Mon-Tue, Aug 31-Sep
- High winds for parts of the Alaskan and Kenai Peninsulas, and Kodiak
Island, Mon, Aug 31.
- Much below normal temperatures for parts of central and eastern Alaska,
Mon-Wed, Aug 31-Sep 2.
- A slight risk of much above normal temperatures for parts of the
central/southern Great Plains and lower and Middle Mississippi Valleys,
Sat-Fri, Sep 5-11.
- Severe drought for parts of the western third of the CONUS, southern Great
Plains, lower Mississippi Valley, Southeast, and Hawaii.
Tropical Storm Erika which on Aug 28 is located near 18N 69W is
forecast to move northwestward south of the Bahamas and be near southern
Florida early Monday morning. The storm is exected to continue moving slowly
north/northwestward across FLorida and be over northern Florida early Wednesday
morning. While the exact track and strenth of this system is highly uncertain,
heavy rain (in excess of 1 inch in 24 hours) is anticipated for parts of the
southeast Monday-Thursday. High winds (in excess of 35 knots) are also expected
for parts of the southeast Monday-Wednesday. Flooding is possible for a small
portion of west-central Florida. Please consult the latest advisories from NHC
at www.nhc.noaa.gov regarding this system and refer to local NWS offices for
the latest statments.
Antecedent heavy rainfall leads to possible flooding for parts of the Upper
and Middle Mississippi Valleys.
Low pressure over the Gulf of Alaska is expected to cause onshore flow and
lead to heavy rain (in excess of 1 inch in 24 hours) for parts of northwest
Washington state Monday-Tuesday. The tight pressure gradient between the low
over the Gulf of Alaska and high pressure over the northeast Pacific leads to
high winds (in excess of 35 knots) for parts of the Alaskan and Kenai
Peninsulas, and Kodiak Island Monday.
Marginal critical fire weather conditions are possible for parts of the
central Great Basin, northern Intermountain west, northern and central Rockies,
and northern Plains Wednesday. A hazard area is not currently specified but
ongoing fires are leading to poor air quality for the region.
North-northwesterly flow behind the area of low pressure forecast over the
Gulf of Alaska and building surface high pressure over much of the state is
expected to lead to much below normal temperatures for parts of central and
eastern Alaska Monday through Wednesday.
Tropical activity over the eastern Pacific will need to be watched as
systems move westward toward the vicinity of Hawaii. Hurricane Ignacio, which
on Aug 28 is located near 14N and 144W, is forecast to move northwestward
toward Hawaii. By earl morning Aug 31, Hurricane Ignacio is forecast to be east
of Hawaii and move northwestward from there. Possible impacts on Hawaii include
heavy rain, strong winds, and sigificant waves. Please consult the latest
advisories from NHC at www.nhc.noaa.gov regarding the evolution of this system
and its influence on the Hawaiian islands. For Saturday September 05 -
Friday September 11:
An upper-levle ridge building over the central and
east-central CONUS leads to a slight risk of much above normal temperatures for
parts of the central/southern Great Plains and lower and middle Mississippi
valleys Sep 5-11.
According to the U.S. Drought Monitor map, valid on August 25, the coverage
of severe to exceptional drought (D2 to D4) decreased from 18.21 to 18.07
percent across the contiguous U.S. since the previous 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.