US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
301 PM EDT Wed Apr 14 2021
 
Valid Saturday April 17 2021 - Wednesday April 21 2021
 
Hazards:
- Heavy rain across portions of the Southeast, Sat, Apr 17.
- Heavy rain across portions of the Southeast, Sun-Tue, Apr 18-Apr 20.
- Flooding possible across portions of the Southeast and the Lower Mississippi Valley.
- Flooding occurring or imminent across portions of the Lower Mississippi Valley.
- High winds across portions of the Northeast, Sat, Apr 17.
 
Detailed Summary:

Hazard areas will be limited to the eastern U.S. during the medium range forecast period (Saturday, 
April 17 - Wednesday, April 21). On Saturday, a departing low pressure system will increase the 
pressure gradient along the New England coast leading to a high winds for the area. The main 
concern during the medium range will be across portions of the Southeast as an area of low pressure 
moves along a quasi-stationary front draped across the Gulf Coast and the Atlantic. This system is 
forecast to produce multi-day rain event with multiple inches of rain likely from the central Gulf 
Coast to southern Georgia and through central Florida. Heavy rainfall is likely to last through 
Tuesday before high pressure builds over the Central U.S. and kicks the area of low pressure out to 
sea. Troughing in the Central/Southern Rockies will lead to the potential for accumulating snow in 
the high elevation portions of the region on Saturday. 

Elsewhere, a shortwave trough will sweep through the Rockies and Plains beginning Sunday. The 
associated surface cold front may produce accumulating snowfall for the peaks of the Central and 
Northern Rockies on Monday. As this system flashes across the central and southeastern U.S. on 
Tuesday and Wednesday, high pressure will fill in across the Central Plains and Mississippi Valley. 
This area of high pressure will contribute to the potential for a hazardous freeze on Tuesday night 
for parts of the Central Plains and Middle Mississippi Valley. Considering how unusual it is for 
there to be a freeze during this time of year for parts of that area, agriculture may be impacted 
by the potentially low minimum temperatures. There isn't enough model confidence in the cold 
temperatures to warrant a 'much below normal' hazard area at this time.

For Alaska, no weather hazards are expected during this forecast period. Above normal temperatures 
are expected to continue across the North Slope, but are not considered hazardous at this time. 
Elsewhere, there is a growing signal for high winds across the Aleutian Islands by Tuesday, but 
high uncertainty remains and therefore no highlighted hazard area was added to today's graphic.

Kebede/Snell