Valid Monday, August 25, 2014 to Friday, September 05, 2014
Summary of Forecasts and Hazards
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT August 22 2014Synopsis
: A stationary front is predicted to
stretch from the Great Lakes to the Four Corners Region for much of the first
half of this period. Upstream a cold front is expected to enter the Pacific
Northwest by late next week. South of this front, temperatures are forecast to
be above normal with daily highs well into the 90s. Meanwhile, areas behind
this front across the Northern Plains are expected to experience cooler,
below-normal temperatures. Hazards
Summary For Monday August 25 - Friday August 29:
- Heavy rain for parts
of the Middle and Upper Mississippi Valley, Central Plains, and Great Lakes,
Mon-Wed, Aug 25-27.
- Much above normal temperatures for parts of the Central and Southern
Plains, Mon-Tue, Aug 25-26.
- Excessive heat for parts of the Middle and Lower Mississippi, Ohio, and
Tennessee Valleys, Mon-Tue, Aug 25-26.
- Much below normal temperatures for parts of the Northern Rockies, Sat-Mon,
Aug 30-Sep 1.
- Severe drought for the Central and Southern Great Plains, Southwest,
Pacific Northwest, Great Basin, and California.
An upper-level shortwave is forecast to propagate across the western
two-thirds of the CONUS during week-1. The associated stationary front ahead of
this shortwave is expected to bring heavy rain to parts of the Middle and Upper
Mississippi Valley, Central Plains, and Great Lakes Monday to Wednesday. Some
models indicate the potential for some areas to receive between 2 and 3.5
inches in a 24-hour period, with the greatest amounts expected over Nebraska
An upper-level ridge is predicted to dominate over South-Central and
Southeastern CONUS early in the period. This pattern is expected to support
much above normal temperatures across parts of the Central and Southern Plains
Monday to Tuesday. Daily maximum temperatures in parts of this area are
anticipated to be 12 degrees F above normal. Parts of the Middle and Lower
Mississippi, Ohio, and Tennessee Valleys have an elevated risk of excessive
heat Monday to Tuesday. Parts of these areas may experience daily maximum heat
index temperatures of 105 to 110 degrees F, with the highest heat index
temperatures expected for lower Louisiana, potentially reaching 110 to 115 F.
The tropical eastern Pacific is predicted to remain very active during this
period with three disturbances currently identified as of August 22, 7:37am
PDT. Tropical storm Karina is the furthest west of these cyclones. Tropical
storm Lowell is located northeast of Karina and expected to impact Karina's
path. The current tropical storms are currently forecast to remain well out to
sea and not affect land.
In the tropical Atlantic, as of 2pm EDT on Friday August 22, the National
Hurricane Center (NHC) is predicting a 70% chance of a current disturbance
forming into a tropical system during the next five days. In general, the
majority of today's numerical models have taken this feature further east
offshore than in yesterday's runs, precluding any associated hazards from being
identified at this time. Updated conditions and forecasts should be monitored
using NHC's webpage at http://www.nhc.noaa.gov. For Saturday August 30 - Friday
The 06Z Deterministic GFS and GEFS Mean indicates the
possibility of surface low pressure extending from central Canada into the
Great Plains during the first half of the week-2 period. This pattern may
support much below normal daily minimum temperatures across parts of the
Northern Rockies next Saturday to the following Monday. The GEFS Reforecast
Tool indicates a 20% chance of this area experiencing daily minimum
temperatures below the lower 15th percentile and up to a 60% chance of
subfreezing temperatures, with the Rockies in Wyoming having the greatest
The most recent U.S. Drought Monitor, released on August 21, shows the
percentage of CONUS in severe drought decreasing very slightly from 22.03% to
Forecaster: Melissa Ou
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.