Valid Friday August 07, 2015 to Tuesday August 18, 2015
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT August 04 2015Synopsis
: A low pressure center is forecast to
move from North Carolina northeastward to the Gulf of Maine during the first
few days of the Outlook period, with its associated cold front expected to push
into the deep South. Another frontal system is anticipated to move eastward
across the northern CONUS during the same time period, weakening as it
approaches New England. These two systems are predicted to be the main
producers of precipitation during the 3-7 day period across the contiguous U.S.
Tropical storm Guillermo, currently located over the east-central tropical
Pacific Ocean, is forecast to pass north of the Hawaiian Islands prior to the
beginning of this Outlook. A fairly large low pressure system is anticipated to
affect southwestern and southern Alaska. Hazards
Summary For Friday August 07 - Tuesday August 11:
rain from Virginia northeastward to Massachusetts, Fri-Sat, Aug 7-8.
- Excessive heat for the eastern half of the southern Plains, and the lower
Mississippi Valley, Fri-Tue, Aug 7-11.
- Severe drought for parts of the western third of the CONUS, southern
Georgia, southern Florida, North Carolina and Hawaii.
- Slight chance of much above-normal temperatures across the eastern half of
the southern Plains, the lower Mississippi Valley, and portions of Alabama and
the Florida Panhandle, Wed-Fri, Aug 12-14.
A low pressure center moving northeastward from North Carolina to the Gulf
of Maine is predicted to bring heavy rain (up to 2 inches) to the I-95 Corridor
between Washington, D.C., and Boston, on Friday and Saturday. The associated
cold front is forecast to push into the deep South, before stalling. The
Florida panhandle may an inch of rain during the same two-day period, but this
amount does not exceed hazardous criteria.
An area of excessive heat is designated across the eastern half of the
southern Plains, and the lower Mississippi Valley during this period. Daily
maximum heat indices are forecast to range between 105-110 degrees F. The
places most likely to experience these conditions for this entire 5-day period
are near the Gulf Coast.
According to the USDA Forest Service, there are about 2 dozen large
wildfires in progress across the West Coast states, with the greatest
concentration of wildfires in California. Most of the fires in northern and
central California have burned less than 14,000 acres. However, there is a
prominent exception. Just north of San Francisco (Lake County), there is a
wildfire that has already burned 62,000 acres, which is a 15 percent increase
from yesterday. This wildfire is only 12 percent contained at this time. Many
of the wildfires near the West Coast appear to be related to stronger winds
associated with a 500-hPa trough near the coast, and the presence of dry
vegetative fuels in this region.
As of 5am Hawaiian Time, Tropical Storm Guillermo was located about 430
miles east of Hilo, HI, moving toward the Hawaiian archipelago. It is still a
strong tropical storm, with maximum sustained winds of 70 mph. The official
track, issued by the Central Pacific Hurricane Center (CPHC) in Honolulu, has
Guillermo passing north of Hawaii as a still-potent tropical storm before the
start of this period. Even though it appears that the Islands will be spared
the worst of Guillermo, residents are encouraged to keep updated on the future
progress of this storm by consulting local news media, and/or the CPHC at:
http://www.prh.noaa.gov/hnl/cphc/ until the hazard passes. In the Atlantic
basin, a low pressure area with increasing thunderstorm activity and 35 mph
winds (east and south of the center, over water) is currently located near
Myrtle Beach, SC. Even if this system develops further, it is expected to move
away from the East Coast tonight and tomorrow. Please refer to the National
Weather Service and local news media for updates on this system.
A fairly large low pressure system is predicted to move eastward across the
southern coast of Alaska during this period, bringing clouds and precipitation.
However, at this time, no weather-related hazards are expected with this
system. For Wednesday August 12 -
Tuesday August 18:
By the end of the 3-7 day period, and into at least the
first half of Week-2, the highest 500-hPa heights associated with the
subtropical ridge are forecast to be located over the southern Great Plains
region. This favors a slight risk of much above-normal temperatures across the
south-central CONUS. Mid-tropospheric troughs are anticipated near the Pacific
Coast, and the Atlantic Coast states.
The latest weekly U.S. Drought Monitor map, released on July 30th, shows a
slight increase in the coverage of severe to exceptional drought (D2 to D4)
across the contiguous U.S., from 16.74 percent to 17.17 percent. According to
AHPS, rainfall has been below-normal during the past two weeks for most areas
east of the Mississippi River, though with one significant exception. For most
of the northwest quarter of the Florida peninsula, rainfall amounts have ranged
from 5-8 inches above normal, and even higher in some localized areas. This is
associated with a weak area of low pressure over northern Florida. In contrast,
southern Florida is running a 1-3 inch rainfall deficit during the last 14
Forecaster: Anthony Artusa
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.