US Day 3-7 Hazards Outlook
NWS Weather Prediction Center College Park MD
413 PM EDT Mon Jun 22 2020
 
Valid Thursday June 25 2020 - Monday June 29 2020
 
Hazards:
- Heavy rain across portions of the Southern Plains, Thu, Jun 25.
- Heavy rain across portions of the Upper Mississippi Valley, the Northern Plains, and the Northern 
Rockies, Mon, Jun 29.
- Heavy rain across portions of the Great Lakes, and the Upper/Middle Mississippi Valley, Fri, Jun 
26.
- Heavy rain across portions of the Great Lakes, the Northeast, the Central Appalachians, and the 
Ohio Valley, Sat, Jun 27.
- Flooding occurring or imminent across portions of the Mid-Atlantic, the Southern Plains, the 
Upper Mississippi Valley, and the Northern Plains.
- Flooding likely across portions of the Mid-Atlantic.
- Much above normal temperatures across portions of California, the Central Great Basin, the 
Pacific Northwest, the Northern Rockies, and the Northern Great Basin, Fri, Jun 26.
 
Detailed Summary:

Upper-level energy over Southern Texas and onshore flow will aid in producing showers and 
thunderstorms along the Western Gulf Coast that will produce heavy enough rain to meet the criteria 
for heavy rain over the Southern Texas Coast on Thursday.  Moisture moving northward over the 
Plains will move into the Upper Midwest and pool along the boundary producing showers and 
thunderstorms over parts of the Upper/Middle Mississippi Valley and along the East Coast of Lake 
Michigan on Friday.  The associated heavy rain will meet the criteria for heavy rain over the 
region on Friday.  The associated plume of moisture will move eastward over the Lower Great Lakes 
on Saturday.  The approaching front and associated upper-level energy will aid in producing showers 
and thunderstorms over parts of the Ohio Valley/Central Appalachians and the Lower Great Lakes that 
will be heavy enough to meet the criteria for heavy rain over this area on Saturday.  

Meanwhile, a developing upper-level low over the Pacific Northwest will move southeastward to parts 
of the Northern Rockies by Monday.  The upper-level low will pull moisture from the Plains into the 
Northern Rockies.  The system will produce rain with embedded thunderstorms that will produce rain 
heavy enough to meet the criteria for heavy rain over parts of the Northern Rockies on Monday.  

Another hazard will develop over parts of the Pacific Northwest on Friday.  Upper-level ridging 
over the Pacific Northwest into the Northern Rockies will allow temperatures to meet the criteria 
for much above normal temperatures over the Northwest on Friday.  

Over Alaska, low pressure moving into the Gulf of Alaska will move eastward to the Alaska Panhandle 
by Friday.  The system will produce rain over parts of the Aleutians but the rain will not meet the 
criteria for heavy rain on Thursday.  Likewise, when the system moves into the Alaska Panhandle 
there will be rain yet not heavy enough to meet the criteria on Friday.  Low pressure near the 
Aleutians will move into the Bering Sea on Sunday and into the Southwest Coast of the Alaska 
Mainland by Monday.  In addition a front over for Eastern Russia will move across the Bering Sea 
into the West Coast of the Alaska Mainland by Monday, too.  The systems will produce rain over 
parts of the mainland on Monday, again the rain will not be heavy enough to meet the criteria for 
heavy rain.   


Ziegenfelder