US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
359 PM EDT Fri Aug 23 2019
 
Valid Monday August 26 2019 - Friday August 30 2019
 
Hazards:
- Heavy rain across portions of the south-central Plains into the Ozarks, and from the upper 
Midwest to the upper Great Lakes, Mon-Tue, Aug 26-Aug 27.
- Heavy rain across portions of the central Plains, Fri, Aug 30.
- Heavy rain along the Outer Banks of North Carolina, Mon, Aug 26.
- Flooding occurring or imminent across portions of the Northern Plains.
- Flooding likely across portions of the Northern Plains.
- Excessive heat across portions of the interior valley of southern California, Mon-Wed, Aug 26-Aug 
28.
- Excessive heat across portions of the southern High Plains, Mon, Aug 26.
- Much above normal temperatures across portions of western Oregon, Tue-Wed, Aug 27-Aug 28.
- Heavy rain across the southern portion of the Alaska Panhandle, Tue, Aug 27.
 
Detailed Summary:

A reinforcing push of cool air will usher into the northern Plains and the Great Lakes during the 
early to middle part of next week as an upper level trough is forecast to amplify.  Heavy rainfall 
and possibly strong thunderstorms will likely move across the upper Midwest followed by the upper 
Great Lakes next Monday into Tuesday ahead of a strong cold front.  An area of heavy rain is also 
possible over the south-central Plains and into the Ozarks early next week as the trailing cold 
front interacts with an old boundary lifting north from the Gulf Coast.  By late next week, a third 
push of cool air from Canada may reach the central Plains and interact with the aforementioned 
front to result in heavy rain, the confidence of which is relatively low at this point.

Meanwhile, confidence is increasing for a rather broad low pressure area with tropical 
characteristics to interact with a synoptic front near the coast of the southeast U.S. early next 
week.  The northern fringe of the heavy rain associated with this low is forecast to brush the 
North Carolina coast.  Thus, an area of heavy rain is indicated along the Outer Banks of North 
Carolina on Aug 26.  Depending on the size and strength of this low pressure area, some increase in 
winds and swells could also be felt along the Outer Banks on Monday and possibly into early on 
Tuesday.

In terms of temperatures, the influx of cool air from Canada along with partly to mostly cloudy 
skies will keep daytime temperatures 10 to more than 15 degrees below normal across the northern 
Plains through the medium-range period.  The much cooler than normal conditions are not depicted on 
the map since it does not appear to present a hazard with overnight temperatures remaining well 
above freezing.

By contrast, excessive heat can be expected over the southern High Plains on Monday as down slope 
winds from the Mexican Plateau keep conditions hot.  Excessive heat can also be expected over the 
southern portion of the interior valley of California early to middle of next week.  Over the 
Pacific Northwest, an upper-level ridge will promote hot conditions in western Oregon where 
afternoon temperatures are forecast to reach the mid-90's to the lower 100 degrees.  Meanwhile, 
heat and humidity will persist also much of Texas.  Southern Texas could see heat indices reaching 
110 degrees, or near the excessive heat criteria, in some spots early to middle of next week.

In Alaska, global models are now indicating the likelihood of heavy rainfall to impact the southern 
part of the Alaska Panhandle next Tuesday into early Wednesday ahead of an occluded low.  Parts of 
the Alaska Panhandle is still officially in a drought.  Heavy rain falling over the complex terrain 
across this region may make it more susceptible to flash flooding.

Kong