Valid Monday October 27, 2014 to Friday November 07, 2014
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT October 24 2014Synopsis
: Low pressure systems are predicted
to bring unsettled weather to New England, the Pacific Northwest, and southern
Florida, while the rest of the Lower 48 is expected to see relatively calm
weather. No cold air outbreaks are expected, as the flow is predicted to come
primarily off the Pacific Ocean. Hazards
Detailed Summary For Monday October
27 - Friday October 31:
- Heavy rain
along the West Coast from Northern California to the Canadian border, Mon-Wed,
- High winds across the Upper Midwest and Great Lakes, Tue, Oct 28.
- High winds across New England, Mon, Oct 27.
- High winds and significant waves for the western Alaskan coast, Mon, Oct 27
and again Thu, Oct 30.
- High winds and significant waves for the southwestern Alaskan coast,
Wed-Thu, Oct 29-30.
- High winds for the southern Alaskan coast and panhandle, Thu, Oct 30.
- Severe drought for the Central and Southern Great Plains, Southwest,
Southeast, Pacific Northwest, Great Basin, and California.
A strong upper-level trough is forecast to move
through southern Canada and amplify as it moves past the Great Lakes and the
northeast. Its associated surface low is then expected to strengthen and
increase the pressure gradient around it. This strong pressure gradient is
predicted to lead to high winds for the Upper Midwest and Great Lakes on the
26th and the northeast on the 27th.
Concurrently, an upper-level trough is forecast to make its way across the
Lower 48. Warm, moist flow from the Gulf of Mexico is expected ahead of the
surface cold front, leading to showers and locally severe weather. The low is
currently predicted to intensify as it nears the Great Lakes, which means the
greatest chance for heavy rain and widespread severe weather exists from the
Ohio Valley back down to the Lower Mississippi Valley on either Tuesday the
28th or Wednesday the 29th. Also, on the backside of the storm, enough cold
air might exist for some snow in parts of the Dakotas and Upper Midwest. At
this time, any potential snowfall does not appear to reach hazardous criteria,
but is mentioned as it would be the first appreciable snowfall this season for
this part of the country.
The remnants of Tropical Storm Ana is then expected to interact with an
extratropical upper-level trough and move into the Pacific Northwest. While
the exact details of this interaction remain uncertain, there is a good level
of confidence that Ana's remnants will bring heavy rain along the West Coast,
from northern California to the Canadian border from the 27th to the 29th. An
additional 3 to 5 inches of rain is possible during this time period.
Considering the almost 10 inches that will have fallen during the past seven
days as well as before this Outlook period begins, flooding is a distinct
possibility. This moisture is also predicted to bring heavy low elevation rain
and high-elevation snow to parts of northern Idaho.
An upper-level trough is forecast to move from northeastern Russia across
the Bering Sea. The associated surface low is expected to direct high winds
and significant waves to the west coast of Alaska, from about the Kuskokwim
Delta to Kotzebue Sound on the 26th and 27th. Concurrently, a very strong
storm is forecast to form and move from just north of Japan into the Bering
Sea. This storm is predicted to bring another round of high winds and strong
waves to most of the west coast of Alaska from the 29th to the 30th.
For Saturday November 01 - Friday November 07:
There is a lot of
disagreement at this time range between the GFS and other numerical models.
The GFS predicts a strong upper-level trough digging down into the Mississippi
Valley with a strong coastal low developing off the mid-Atlantic Coast. This
solution would bring heavy rain to the coasts and heavy snow to the
Appalachians and Great Lakes. However, other models do not amplify the trough
this deeply, and instead, a surface low skims New England. This would bring
the potential of heavy snow to Maine, but due to the uncertainty, no hazards
are indicated at this time.
The most recent Drought Monitor, released October 23, shows a slight
decrease in the areal coverage of severe drought, from 18.01% to 18.0%. There
is also the largest amount of areal extent without any level of dryness since
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.