Valid Friday, July 25, 2014 to Tuesday, August 05, 2014

Summary of Forecasts and Hazards

US Hazards Outlook
NWS Climate Prediction Center College Park MD
300 PM EDT July 22 2014

Synopsis: At the beginning of the period, an area of upper-level high pressure is forecast over the southwest U.S., while upper-level low pressure is anticipated over the northwest. The area of upper-level low pressure is then expected to move east to the Northern Plains, Upper Mississippi Valley, and Great Lakes and be replaced by strong upper-level high pressure by end of the week 1/start of the week 2 period. Early in the period, an area of surface low pressure is expected to movel slowly eastward aross the Gulf of Alaska towards the Alaska Panhandle. Upper-level low pressure is forecast to persist across most of Alaska during the remainder of the period although upper-level high pressure is expected to build over the Aleutians.

Hazards

• Much above normal temperatures for parts of the central Plains and Middle Mississippi Valley, Fri-Sat, Jul 25-26.
• Heavy rain for parts of the Alaska Panhandle, Fri-Sat, Jul 25-26.
• Much above normal temperatures for parts of the Northern Intermountain West and Northern Rockies, Sun-Thu, Jul 27-31.
• Flooding occurring or imminent for parts of North Dakota.
• Severe drought for parts of the Great Plains, Southwest, Pacific Northwest, Great Basin, and California.

Detailed Summary

For Friday July 25 - Tuesday July 29: A frontal system is expected to bring unsettled weather to much of the eastern CONUS during the period. Areas of heavy rain and severe thunderstorms are possible over parts of the region, but model uncertainty precludes the specification of hazard areas at the current time.

A strong subtropical ridge is likely to strengthen across the Southwest and bring much above normal temperatures for parts of the region. Maximum temperatures are forecast to range from 105 to 115 degrees F across parts of the desert Southwest on Thursday.

A trough over the northwest conus is forecast to move eastward and by replaced by an amlified ridge. This is expected to lead to much above normal temperatures for parts of the Pacific Northwest, Northern Intermountain West, and Northern Rockies towards the end of the period. This is of particular concern since numerous wildfires are burning across the Pacific Northwest and Idaho. Smoke from these wildfires is likely to reduce air quality. [ Southern and Central Wyoming will likely experience coontinued dry and breezy conditions through Friday leading to elevated fire weather conditions]. Confidence is not sufficent to include a critcal fire weather hazard at the current time.

Flooding is expected to persist along the Souris River in North Dakota.

An upper-level trough is forecast to result in an active pattern across mainland Alaska. Although an active pattern is forecast, precipitation amounts and winds speeds are expected to remain below hazards criteria.

Tropical activity over the eastern Pacific will need to be monitored for possible impacts over Hawaii.

For Wednesday July 30 - Tuesday August 05: Early in the period, upper level ridging is forecast to prolong much above normal temperatures for parts of the Pacific Northwest, Northern Intermountain West, and Northern Rockies.

Based on the latest Drought Monitor valid on July 15, the coverage of severe to exceptional drought across the continental U.S. decreased from 25 to 24 percent during the past week.

Forecaster: Randy Schechter

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Please consult local NWS Forecast Offices for short range forecasts and region-specific information.