US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
500 PM EDT Thu Jul 30 2020
 
Valid Sunday August 02 2020 - Thursday August 06 2020
 
Hazards:
- Heavy rain across portions of northern New York, as well as from eastern Florida northward 
through the Carolinas and all of the Mid-Atlantic, Sun-Mon, Aug 2-Aug 3.
- Heavy rain along the Mid-Atlantic coast into central and southern New England as well coastal 
Maine, Tue-Wed, Aug 4-Aug 5.
- Flooding possible across portions of northern and central Plains.
- Flooding occurring or imminent across portions of the northern Plains.
- High winds across portions of eastern Florida, Sun, Aug 2.
- High winds across much of the Mid-Atlantic and southern New England coastal areas, Mon-Tue, Aug 
3-Aug 4.
- Significant waves possible near the North Carolina coast, Mon, Aug. 3.
- Heavy rain across portions of the Alaska Panhandle and southern Alaska, Sun-Wed, Aug 2-Aug 5.

Detailed Summary:

During the medium range period, attentions will surely be drawn to the East Coast where tropical 
cyclone Isaias could potentially bring significant impacts from Florida all way up to New England.  
The initial synoptic setup will be an amplifying omega block pattern over western Canada in 
conjunction with a positively-tilted trough lingering across the eastern-central U.S.  This pattern 
will likely bring Isaias close to the East Coast early next week as the tropical cyclone tracks 
around the southwestern and western periphery of the Bermuda High.  It appears that all of the East 
Coast will be under a threat of heavy rain associated with Isaias starting from Florida during the 
weekend and then gradually working its way up the East Coast Monday and Tuesday.  Based on the 
latest forecast track of Isaias from the National Hurricane Center (NHC), it appears that much of 
the East Seaboard, except perhaps the Georgia coast, will have a good chance of experiencing high 
winds as Isaias nears.  Significant waves are also possible on Monday near the North Carolina coast 
as Isaias could move across at a close distance.  High seas may expand in coverage along the East 
Coast should Isaias intensifies into a hurricane.  Please consult the NHC for the latest updates on 
Isaias.  Farther inland, a wave of low pressure forming along a frontal boundary ahead of the 
lingering trough over the eastern-central U.S. should lead to heavy rain across northern New York 
Sunday into Monday, before slowly edging further to the east.

Meanwhile, an upper-level ridge will remain a dominant feature over the western U.S. Temperatures 
should be about 5 to 10 degrees above normal across much of the interior western U.S. before an 
upper trough brings cooler air into the Pacific Northwest and the northern Rockies by early next 
week.  High temperatures are expected to top 115 degrees for the hottest locations in Desert 
Southwest Sunday and Monday before moderating very gradually toward the middle of next week.  Over 
the northern and central Plains, much cooler than normal temperatures will remain in place behind 
the aforementioned slow-moving trough.

Over Alaska, the pattern appears to get more active during the medium-range period as a couple of 
significant occluded cyclones are forecast to impact the southern periphery of the state.  This 
appears to be more of a prolonged rain event than heavy rain falling in a short time-frame.  A 
heavy rain is indicated on the map from the southern coastal sections of Alaska down along the 
Panhandle from Saturday into Wednesday.  There could be another occluded cyclone that could bring 
heavy rain into the Panhandle by next Thursday but uncertainty is currently too high to specify a 
heavy rain area at this time.

Kong