Valid Friday October 03, 2014 to Tuesday October 14, 2014
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT September 30 2014Synopsis
: Surface low pressure over the
Northern Great Lakes is forecast to move into Southern Canada as its trailing
cold front moves eastward across the east-central U.S. and off the east coast.
A second area of low pressure is forecast to form on the front over the
Mid-Atlantic and move towards New England. Surface low pressure is expected
over the Gulf of Alaska and southeastern Alaska as another area of low pressure
approaches the Aleutians.
Detailed Summary For Friday October
03 - Tuesday October 07:
- High winds for parts of the Northern
Plains, Upper Mississippi Valley, and Great Lakes, Fri-Sat, Oct 3-4.
- Heavy rain for parts of the Northeast, Fri-Sat, Oct 3-4.
- Heavy rain for southern parts of the Alaska Panhandle, Fri, Oct 3.
- Flooding occurring or imminent for parts of west-central Florida.
- Severe drought for the Central and Southern Great Plains, Southwest,
southern Georgia, Pacific Northwest, Great Basin, and California.
An amplified upper-level trough is expected to
move slowly from the western states to the east coast during this forecast
period. As it does, heavy rain and localized severe weather is anticipated in
association with the trough's attendant surface cold front in parts of the
Lower and Middle Mississippi Valleys into the Ohio Valley. Rainfall totals of 2
inches or more in 24 hours are possible in these locations.
As the trough moves eastward, it is forecast to negatively tilt, creating
surface cyclogenesis off the East Coast. With strong flow off the ocean at low
and mid levels, ample moisture should be able to move into northern New
England. This setup makes heavy rain likely for these areas with totals of up
to 2 inches possible in 24 hours.
Strong winds are possible on the backside of this system, although at this
time, the wind speeds are not forecast to reach hazardous criteria.
Upstream of this trough, upper-level ridging is predicted for the west
coast, with surface high pressure moving into the Four Corners region. This
setup favors strong downslope winds for most of California. These winds are
forecast to increase the daytime maximum temperatures into the low 90s with
isolated locales seeing higher values. However, the forecast temperature
anomalies do not warrant a hazard at this time. Despite the combination of
warm temperatures, gusty winds, and dry soils, no enhanced risk of wildfires is
indicated due to uncertainty in the strength of these anticipated downslope
In the northern Pacific, a very strong storm is forecast to move south of
the Aleutians and impact the Alaskan panhandle and west coast of Canada. Heavy
rainfall of at least 5 inches is possible, and with recent heavy rains, large
mudslides are a significant possibility. For Wednesday October 08 -
Tuesday October 14:
Tropical Storm Phanfone is expected to intensify into
a hurricane and come very close to Japan before recurving out to sea. Most
numerical models indicate this recurvature will cause an amplification of the
downstream upper-level pattern, increasing the chances of a deep trough
somewhere over the CONUS allowing anomalously cold air to enter the CONUS.
Interestingly, the ECMWF model forecasts Phanfome to be a much weaker storm and
correspondingly has a more zonal forecast for the 8-14 day period.
The U.S. Drought Monitor, valid on September 23, indicates that the
percentage of the CONUS in severe to exceptional drought decreased to below 19
Forecaster: Kenneth Pelman
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.