Skip Navigation Links www.nws.noaa.gov 
NOAA logo - Click to go to the NOAA home page National Weather Service   NWS logo - Click to go to the NWS home page
Climate Prediction Center

U.S. Hazards Outlook - Made Sep 01, 2015

Composite Images

Day 3-7 Outlook Day 8-14 Outlook Day 8-14 Probabilistic Temperature Hazards

Valid Friday, September 04, 2015 to Tuesday, September 15, 2015

Summary of Forecasts and Hazards

US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT September 01 2015

Synopsis: Surface high pressure is predicted to move from eastern Canada into the eastern United States with a strong low pressure moving through the High Plains. This pattern favors precipitation from the southwestern states into the Dakotas. Below normal temperatures are forecast for the western states with above normal temperatures favored for the eastern states.

Hazards
  • Severe drought for parts of the western third of the CONUS, southern Great Plains, lower Mississippi Valley, Southeast, and Hawaii.
  • Flooding possible for parts of west-central Florida.
Detailed Summary

For Friday September 04 - Tuesday September 08: This forecast period is expected to begin with an upper-level trough amplifying along the West Coast, with an upper-level ridge from eastern Texas to the northern Gulf Coast. This pattern favors below normal temperatures in the western states with above normal temperatures in the eastern states. The greatest chance of significant precipitation extends along the western periphery of the upper-level high from the mountains in the Southwest to the High Plains and the Dakotas.

By the end of this period, moisture from the remnants of TD 14E south of Baja California could get drawn into the CONUS, increasing the potential amounts of precipitation in the Southwest. At this time, no large-scale hazards are denoted on the map, but localized flooding is possible in any heavy downpours that might occur.

Surface low pressure in the Plains combined with high pressure in Canada is expected to lead to strong northeasterly upslope flow from Idaho through Montana into the Dakotas. While significant precipitation is likely, the forecast amounts do not reach hazardous criteria, although some localized flooding is possible.

In the West, as individual shortwaves rotate around the base of the trough, enhanced winds are possible, and given the dry conditions, an enhanced wildfire risk from Nevada into Utah cannot be ruled out. However, there is too much model uncertainty in regards to the magnitude of the surface winds, thus no hazards are denoted on the map.

For Wednesday September 09 - Tuesday September 15: By the time this forecast period begins, the remnants of Hurricane Ignacio are expected to merge into the mid-latitude westerly flow. How this will impact the downstream flow is uncertain. At this time, models are forecasting the amplification of an upper-level trough south of the Aleutians. This pattern favors continued chances of heavy rain for the southern and southeastern coasts of Alaska for the middle and end of this period. However, because numerical models have a notoriously hard time in forecasting the curvature of tropical systems into the mid-latitude jet stream, no hazard is placed on the map. If the models continue to forecast heavy rain over the next few days, a hazard could be introduced with more certainty.

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.

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.


NOAA/ National Weather Service
NOAA Center for Weather and Climate Prediction
Climate Prediction Center
5830 University Research Court
College Park, Maryland 20740
Page Author: Climate Prediction Center Internet Team
Page last modified: August 22, 2011
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities