The Southwest monsoon will remain active on Thursday, bringing both beneficial rain and a risk of flash flooding to some areas in New Mexico, Arizona, Colorado, Utah and Nevada.
Some locations that can be hit by thunderstorms are Tucson and Flagstaff, Ariz., Grand Junction, Colo. and Santa Fe, N.M.
The more intense thunderstorms, which not everyone will see, can produce wind gusts over 50 mph, torrential downpours and flash flooding.
Thunderstorms will initially develop over the mountains then slowly drift over the lower elevations. The slow movement is one aspect that can make these thunderstorms prolific producers of rain in a monsoonal pattern, and this will be the case today.
Runoff from these downpours will cause rapid water rises in creeks and quickly turn normally dry washes (arroyos) into raging rivers. This can pose a danger miles away and downhill from the heavy rain.
If you are hiking through a dry wash or valley and observe a thunderstorm in the distance, you should seek higher ground, as water can fill up a dry wash with torrents of water and debris with little notice.
Another hazard will be lightning, and it takes just a single strike to spark a wildfire since the region is still dry despite the recent rainfall.
Gusty winds from thunderstorms today can create blowing dust and reduce visibility to near zero, making travel extremely challenging. Interstates 10, 25 and 40 are in the threat area.
Once evening arrives, showers and thunderstorms will gradually weaken with light showers in a few spots leftover during the night.
Umbrellas and raincoats will be put to good use by those along much of the Interstate-95 corridor as rain moves northward during the middle of the week.
Temperatures will rebound across the Northeast this coming weekend, after a setback with clouds and rain along the coast before Friday.
A storm from the Pacific Ocean will first raise the fire danger in California, then bring cooler air and spotty rain for firefighting efforts.
A chilly start to fall has provided a sufficient cold blast to bring out the vibrant colors of autumn leaves.
A storm moving up the Atlantic coast with rain will briefly disrupt the dry weather and warming trend this week around Washington, D.C.
Snow in the Appalachians.
Stowe, VT (1885)
12" of snow.
Washington, D.C. (1980)
Temperature hit 90 degrees for the 67th time in 1980. Never had there been a year in recorded history with so many 90-degree readings. The previous record was 59 days in 1966.