Valid Friday September 30, 2016 to Tuesday October 11, 2016
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT September 27 2016Synopsis
: A weakening cold front is
expected to move off the Gulf and Atlantic Coasts early in the Outlook period.
Broad low pressure at the surface and aloft, associated with the cold front, is
forecast to linger over the Ohio Valley before finally lifting out to the north
this Sunday. Another cold front is predicted to move across the western and
into the central contiguous U.S. during this same period. In the Alaska domain,
several frontal systems are anticipated to affect the western portion of the
state during the first half of the Outlook period. A well-organized tropical
wave currently about 350 miles away from the Windward Islands continues to move
west-northwest. This system may have a significant impact on the Southeast
CONUS early next week. Hazards
Detailed Summary For Friday
September 30 - Tuesday October 04:
- Lingering heavy rain from
Ohio to Pennsylvania, Fri, Sep 30.
- Heavy rain for southwestern Alaska, Sat-Sun, Oct 1-2.
- Flooding is likely, imminent, or occurring in portions of the Midwest, and
- Slight risk of much below-normal temperatures for much of the west-central
CONUS, Wed-Thu, Oct 5-6.
- Severe Drought across parts of the Eastern CONUS, Missouri River Valley,
Great Plains, Northern Rockies, Intermountain West, Arizona, California, and
A pronounced cut-off Low at 500-hPa is
forecast to bring cloudy and cool conditions to areas primarily east of the
Mississippi River, at least into Sunday, Oct 2. By then, the cut-off Low is
predicted to weaken and lift northward into southern Quebec. At the surface, a
cold front is expected to push off the Atlantic and Gulf Coasts early in the
period, though associated low pressure (and attendant cloudiness) over the Ohio
Valley and mid-Atlantic is predicted to linger across this region for several
more days. Though most of the precipitation is expected to fall prior to the
beginning of the Hazards period, there is still the possibility of heavy rain
continuing across portions of Ohio and Pennsylvania on Friday, Sep 30. The cold
front is forecast to get as far south as central or southern Florida before
stalling, enhancing the chances for showers and thunderstorms in that area from
A tropical wave 350 miles east of the Windward Islands (as of 2pm EDT 9/27)
is predicted to continue its west-northwest heading towards the southern
portion of the Caribbean Sea. A track this far south is unusual. Then the track
of this system becomes highly uncertain, with the ECMWF taking the system over
western Cuba or the Yucatan Channel, and the GFS and Canadian models recurving
it a bit earlier over/near Haiti. Much will depend on the exact evolution of
the upper-tropospheric flow pattern across the Gulf of Mexico and western
Caribbean. At this time, it is recommended that residents of central and
southern Florida keep an eye on this system, which the National Hurricane
Center predicts has a 90 percent chance of developing into a tropical cyclone
in the next 5-days.
Flooding is likely, imminent, or occurring in portions of the Midwest and
southern Texas from Sep 30-Oct 2. This is primarily due to rain that recently
fell across these areas.
A cyclonic system is predicted to bring heavy rain (2 inches or greater) to
southwestern Alaska on Oct 1-2. The deterministic 0z ECMWF and 6z GFS runs
forecast in excess of 4 inches during this period across the vicinity of the
eastern Alaska Peninsula. For Wednesday October 05 -
Tuesday October 11:
There is a slight (20 percent) chance of much
below-normal temperatures (at or below the 15th percentile of the historical
temperature distribution) across much of the west-central CONUS on Oct 5-6, in
association with a strong 500-hPa trough. At the highest elevations,
temperatures are expected to be cold enough to support snow.
According to the latest U.S. Drought Monitor (USDM) valid on September 20,
the coverage of severe or greater drought (for the CONUS) increased very
slightly from 7.72 to 7.76 percent during the past week. Less than 1 percent
of the Hawaiian Islands is designated with severe drought.
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.