US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
302 PM EDT Fri Jun 21 2019
 
Valid Monday June 24 2019 - Friday June 28 2019
 
Hazards:
- Heavy rain across portions of the Lower Mississippi Valley and the Southern Plains, Mon, Jun 24.
- Flooding possible across portions of the Northeast, the Southern Plains, the Middle Mississippi 
Valley, the Mid-Atlantic, the Great Lakes, and the Ohio Valley.
- Flooding occurring or imminent across portions of the Central Plains, the Lower Mississippi 
Valley, the Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, and the Ohio Valley.
- Flooding likely across portions of the Central Great Basin.
- Excessive heat across portions of the Southeast and the Southern Texas, Mon, Jun 24.
 
Detailed Summary:

An east-west aligned quasi-stationary surface front, associated with a short wave trough lifting 
into the Western Great Lakes region, will extend from the southern Plains across the lower 
Mississippi Valley on Monday. Even though the front is weakening, deep Gulf of Mexico moisture 
combined with a highly unstable air mass along and south of the boundary will still support 
scattered to numerous showers and thundershowers breaking out during Monday afternoon/evening. The 
consensus of current guidance shows the axis of deepest moisture is forecast to run from eastern 
Texas eastward into central Mississippi, so am expecting the best chance for organized activity 
along this part of the front. With storm motions generally parallel to the front, there is a 
possibility for repeat activity that could lead to locally heavy rainfall totals.

Over southern Texas, hot and humid weather will continue through the next week. At the moment, the 
worst of the heat expected on Monday, as temperatures near or above 100F and dew points in the 
low-mid 70s combine to support heat indices approaching 115F. After Monday, there are indications 
that dew points will drop, which should help reduce heat indices to the 105-110 range for the 
remainder of the week.

Over the southeastern U.S., strong mid-upper level ridging will maintain hot and humid conditions, 
with relatively low chances of convection during Monday. The highest heat indices, approaching 
105-110F, will generally be confined to central/eastern South Carolina and eastern Georgia along a 
weak thermal trough. The ridging will begin to break down by late Monday, so temperatures should 
moderate somewhat for the remainder of the week, along with an increasing chance for scattered 
afternoon/evening showers and thundershowers.

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

Klein