US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
321 PM EDT Wed Aug 07 2019
 
Valid Saturday August 10 2019 - Wednesday August 14 2019
 
Hazards:
- Heavy rain across portions of the Central Plains, the Middle Mississippi Valley, the Northern 
Rockies, and Interior Washington, Sat-Sun, Aug 10-Aug 11.
- Heavy rain across portions of the Northern Plains, Sun-Mon, Aug 11-Aug 12.
- Heavy rain across portions of the Middle Mississippi Valley, the Great Lakes, and the Ohio 
Valley, Mon-Tue, Aug 12-Aug 13.
- Flooding possible across portions of the Central Plains and the Middle Mississippi Valley.
- Flooding occurring or imminent across portions of the Northern Plains.
- Excessive heat across portions of the Lower Mississippi Valley and the Southern Plains, Sat-Tue, 
Aug 10-Aug 13.
 
Detailed Summary:

Upper level high will meander over eastern Texas this weekend into next week. High temperatures 
will range from the upper 90s to low 100s with dew points in the lower 70s. This will result in 
maximum heat indices of 105-110 degrees over much of eastern Texas with values approaching 115 
degrees over southeastern Texas and northern Louisiana/southern Arkansas owing to higher dew points 
in the mid and upper 70s.

Around the upper high, northwest flow out of the central Plains through the mid-Mississippi Valley 
combined with a wavy frontal boundary and a humid airmass will support a chance of afternoon 
convection and organized mesoscale convective system (MCS) activity, perhaps continued out of the 
short range. Less confidence exists on Sunday as a wave along the front takes it farther northeast, 
but Monday may see a renewed chance of heavy rainfall as a cold front pushes southward. This may 
extend anywhere from central Missouri eastward into Indiana ahead of the boundary. 

To the north, an upper low and weaker surface reflection will move into the Pacific Northwest this 
weekend and spread modest to locally heavier rainfall over the Cascades through the Columbia 
Basin/interior Washington eastward across the Idaho panhandle into northwestern Montana. Rainfall 
totals will mostly range from 0.5-1.5 inches with locally higher amounts. Sunday into Monday, the 
northern Plains may see heavy rainfall as the system progresses eastward and a cold front pushes 
southeastward. 

Monsoonal moisture flowing through eastern Arizona and the Four Corners region could cause locally 
heavy rainfall and localized flash flooding as afternoon and evening showers and thunderstorms 
continue this weekend. Guidance suggests that precipitation may become lighter and more 
scattered/isolated by next week as the focus shifts into the Southeast, but with low confidence in 
placement/timing.

No hazards are currently forecast for Alaska during the Day 3-7 period.

Fracasso