US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
332 PM EDT Tue Jun 18 2019
 
Valid Friday June 21 2019 - Tuesday June 25 2019
 
Hazards:
- Heavy rain across portions of the Central Plains, the Lower and Mid Mississippi Valley, into the 
the Tennessee Valley, parts of the Ohio Valley, Central Appalachians and the Great Lakes, Sun-Mon, 
Jun 23-Jun 24.
- Heavy rain across portions of the Central Plains, the Middle Mississippi Valley into the Upper 
Midwest and parts of the Great Lakes as well as the Ohio Valley, Fri-Sat, Jun 21-Jun 22.
- Severe weather across portions of the Central Plains, the Middle Mississippi Valley, the Upper 
Midwest, and the Northern Plains, Fri, Jun 21.
- Flooding possible across portions of the Central Plains, the Middle Mississippi Valley, the Great 
Lakes, and the Ohio Valley.
- Flooding occurring or imminent across portions of the Central Plains, the Lower and Middle 
Mississippi Valley, and the Ohio Valley.
- Flooding likely across portions of the Southern Plains, the Central Great Basin, and the Northern 
Great Basin.
- Excessive heat across portions of southern Texas, Fri-Tue, Jun 21-Jun 25.
- Excessive heat across portions of the Mid-Atlantic, Mon-Tue, Jun 24-Jun 25.
- Much below normal temperatures across portions of the northern and central Rockies, the northern 
High Plains, and into parts of the Great Basin, Fri-Sat, Jun 21-Jun 22.
 
Detailed Summary:

A rather deep low pressure system for June should be departing the New England coast Friday morning 
(Jun 21) and heading toward/into the Canadian Maritimes. The ECMWF solution for this cyclone is 
still slower and deeper than the GFS but both models have progressively come into agreement toward 
an intermediate solution. The latest 12Z ECMWF now shows a solution that is similar to the GFS. 
Potentially heavy rainfall over New England should be moving out to the east Friday morning.

In the meantime, yet another cold and deep upper low is forecast to move across the northwestern 
U.S. Friday morning. In fact, global models have been indicating the possibility of snow in the 
higher elevations of the northern Rockies. The GFS was particularly enthusiastic with more than a 
foot of snow predicted for the higher peaks of northwestern Montana. However, the most recent GFS 
run has backed off quite a bit on the snowfall amounts as the associated surface cyclone becomes 
much weaker than in earlier forecasts. In any case, much colder than normal temperatures are 
expected across the northern Rockies with morning lows dipping below freezing at some locations 
through next Tuesday.

As the upper-level low in the Northwest slowly makes its way eastward into the Plains during the 
weekend, it will interact with moisture coming up from the Gulf, leading to heavy rainfall once 
again across the central part of the U.S. Models are indicating two waves of heavy rain during the 
medium-range period. The first wave is associated with a triple-point surface low together with a 
warm front. This system is forecast to spread heavy rain and possibly severe thunderstorms from the 
central Plains eastward into the Midwest Friday and Saturday. The second wave is associated with 
another surface low forming farther to the south along a frontal boundary. This low is forecast to 
spread heavy rain northeastward from the southern Plains into the Ohio Valley from Sunday through 
Tuesday.

Meanwhile, summer heat from the Deep South is expected to spread northeastward into the 
Mid-Atlantic by early next week. Heat indices are forecast to reach 110 degrees across southern 
Texas each day. As the hot and humid air spreads northeastward, heat indices are expected to reach 
105 degrees in interior eastern North Carolina early next week.

No hazardous weather is anticipated for Alaska through the medium-range period.

Kong