US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
408 PM EDT Mon Jul 08 2019
 
Valid Thursday July 11 2019 - Monday July 15 2019
 
Hazards:
- Heavy rain across portions of the Southeast, the Lower Mississippi Valley, and the Southern 
Plains, Thu-Mon, Jul 11-Jul 15.
- Heavy rain across portions of the Northeast and the Great Lakes, Thu-Fri, Jul 11-Jul 12.
- Flooding possible across portions of the Central Plains and the Northern Plains.
- Flooding occurring or imminent across portions of the Northern/Central Plains, the Mississippi 
Valley, and the Ohio Valley.
- Flooding likely across portions of the Central Plains and the Northern Plains.
- Excessive heat across portions of the Southeast, the Lower Mississippi Valley, the Southern 
Plains, and the Tennessee Valley, Thu, Jul 11.
- Enhanced wildfire risk across portions of the the Alaska Panhandle and mainland Alaska, Thu, Jul 
11.
- Much above normal temperatures across portions of mainland Alaska, Thu, Jul 11.
 
Detailed Summary:

Overall, the pattern in the medium range will consist of upper-level ridging centered in the Four 
Corners region to Southern Plains, with an active jet stream to the north--plus the possibility of 
a tropical system forming in the Gulf of Mexico. This potentially tropical low is currently 
forecast to move slowly westward through the Gulf through the end of the workweek, then track 
northward toward the western or central Gulf of Mexico by the weekend. Plenty of uncertainty 
remains as to the exact track and the intensity of this system, as model guidance does not provide 
a good consensus yet. Regardless of development, this low pressure system is expected to cause 
heavy rainfall in the western and central Gulf Coast states. High Winds and Significant Waves 
hazards may need to be added to the hazards graphic as the forecast for this possible tropical 
cyclone gets more refined. 

The northern stream is expected to be active with shortwaves throughout the period, which could 
lead to heavy rainfall in the northern tier of the contiguous U.S. One such shortwave impulse will 
move through the Great Lakes region to Northeast on Thursday and Friday, causing the potential for 
heavy rainfall there. Farther south, a slow-moving front will create the possibility of some heavy 
rain along the coast of the Carolinas through the weekend, but the heaviest precipitation seems to 
remain offshore in the western Atlantic. Rain is also likely ahead of shortwaves in the Northern 
Plains to Upper Midwest by the weekend, but more uncertainty in amounts and placement precluded us 
from drawing a hazard area at this time. 

Heat is expected underneath the upper ridging from the Southwest eastward into the Southeast, which 
will combine with high dewpoints in the Southern Plains to Lower Mississippi Valley and Southeast 
to create high heat indices there on Thursday. Temperatures should decrease after a cool front 
passes in those areas, but heat will persist in the Southwest through early next week. High 
temperatures around 115 degrees plus above average overnight lows necessitated placing a hazard 
area there.

After a long period of upper-level ridging in Alaska causing anomalous heat, the ridge will finally 
be breaking down by the end of this week. The much above normal temperatures should finally abate, 
and cooler temperatures should help the risk of wildfires to decrease as well after Thursday.


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