MCFRS News Release

WARNING - Flash Flooding and Severe Weather Possible

Many Roads in MontgomeryCounty Susceptible to Flooding

County residents are urged to be alert to changing weather conditions and should be prepared for possible flash flooding over the next 24-48 hours as a storm system moves into the area and is expected to bring heavy rains.
The National Weather Service has issued a FLASH FLOOD WATCH for Montgomery County until Thursday Evening. In excess of 4" of rainfall may be possible in some areas. Expected heavy rains may have the potential to cause severe and unexpected flash flooding within the next 24 hours.

When it rains heavily, there may be flash floods, flood warnings and flood watches issued. Flash floods more often occur in mountain streams, hilly areas or low-lying areas. But they do happen in urban and suburban areas like Montgomery County, as well. Flash floods can occur even though it's not raining where you are. It may be raining hard farther upstream and raining so hard that the water can not be absorbed into the ground. 

Safety Tips: 

If a flash flood warning is issued, act immediately. Don't wait for high water to dictate your course of action. 
Know your location when you are driving. If you needed rescue, would you be able to direct emergency crews to your location?  Distracted driving can lead to a situation where you are stranded and unable to direct emergency crews to you.  Be alert!
Never drive through a flooded road or bridge. Back up and try a different route. In many cases, it takes far less than a foot of water to incapacitate a vehicle.  It may stall, leaving you stranded, and depending on the level of water, you may not be able to open a vehicle door.  Do not underestimate the power of moving water.   

Stay on high ground. If your car is trapped, get out if you can safety do so. Move to higher ground. If you're driving through a hilly area or place that is subject to flooding along a stream and hear a flash flood warning, go to high ground – never try to outrun a flash flood.

Watch for flooding at bridges and dips in the road. Never drive where water is over bridges or roads. Turn around. The bridges or the road could suddenly be washed out.  If you're driving at night be especially careful. Often visibility is limited due to wind and rain. If you should drive into water, don't try to drive out of it. Get out of the car and safely return to higher ground.

Often what you can't see below the surface of the water is far more dangerous than the high levels of that water. Remember that rocks, tree limbs and other debris can be caught in moving water and can be dangerous if you are forced to walk, wade or swim through flood waters. 

If you have to walk or wade through flood water, use a stick to poke the ground in front of you with each step. It can help you determine water levels, the bottom surface and the safest possible way to get to higher ground. 

Remember that flash floods can come without warning, and sometimes without weather. Be alert and heed all warnings and recommendations from officials.
From FEMA's website, some further information about driving through flooded roadways: