US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
329 PM EDT Tue Jul 09 2019
 
Valid Friday July 12 2019 - Tuesday July 16 2019
 
Hazards:
- Heavy rain across portions of the Southeast, the Middle Mississippi Valley, the Lower Mississippi 
Valley, the Southern Plains, and the Tennessee Valley, Fri-Tue, Jul 12-Jul 16.
- Heavy rain across portions of the Northeast, Fri, Jul 12.
- Flooding possible across portions of the Central Plains and the Northern Plains.
- Flooding occurring or imminent across portions of the Central Plains, the Lower Mississippi 
Valley, the Northern Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, and the 
Ohio Valley.
- Flooding likely across portions of the Northern Plains.
- Excessive heat across portions of California and the Southwest, Fri-Tue, Jul 12-Jul 16.
- High winds across portions of Southern Louisiana, Fri-Sun, Jul 12-Jul 14.
 
Detailed Summary:

Overall, upper-level ridging across the central and western United States will lead to a relatively 
quiet pattern over most of the country. The exception will be a likely tropical system forming in 
the Gulf of Mexico and impacting the Lower Mississippi Valley. This potential tropical low is 
currently forecast to move slowly westward through the northern Gulf of Mexico by Friday, then 
track northward towards coastal Louisiana and/or eastern Texas 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, as well as inland across the 
Lower Mississippi Valley. High Winds will also be possible with a potential landfalling tropical 
system across coastal Louisiana Friday through Sunday. Be sure to go to www.nhc.noaa.gov for 
official tropical cyclone forecasts.

The other area of concern for heavy rain will be across eastern Vermont and Maine as a shortwave 
trough races across the Northeast on Friday. Amounts will likely add up to less than an inch, 
however localized amounts could exceed this within thunderstorms. 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 across the Southwest. High temperatures around 115 
degrees plus above average overnight lows necessitated placing a hazard area there. An Excessive 
Heat area was considered across the Mid-Atlantic (specifically eastern Virginia and North Carolina) 
as heat indices could approach 105-110 degrees by Sunday, but there is large uncertainty regarding 
cloud cover and precipitation related to the tropical system in the Gulf of Mexico.

After a long period of upper-level ridging in Alaska causing anomalous heat, the ridge will finally 
weaken by the end of this week. Above normal temperatures will remain, but will not be near as 
extreme as the previous week. Therefore, no highlighted areas were necessary. 


Snell