Severe thunderstorm outbreak with tornadoes, wind damage, and large hail are expected today from parts of the southern Plains, eastward into the lower Mississippi Valley and central Gulf Coast states. Several long-track strong tornadoes are expected. Furthermore, excessive rainfall potential exists with flash flooding possible. For the western US, heavy precipitation and strong winds continue. Read More >
Thursday March 26, 2015
...PENNSYLVANIA SEVERE WEATHER AWARENESS WEEK...
THIS IS SEVERE WEATHER AWARENESS WEEK IN PENNSYLVANIA.
NOW IS THE TIME TO PREPARE FOR THE UPCOMING SEVERE WEATHER SEASON.
WE ARE COVERING A DIFFERENT SAFETY TOPIC EACH DAY OF THIS WEEK.
OUR SEVERE WEATHER AND WEATHER SAFETY TOPIC FOR TODAY IS...
RIVER FLOODING AND RIVER FLOOD SAFETY.
PENNSYLVANIA HAS AN EXTENSIVE RIVER SYSTEM THAT IS SCENIC AND
BEAUTIFUL. MOST OF THE TOWNS AND CITIES WERE FOUNDED ON THE BANKS OF
A RIVER OR LARGE CREEK. THIS MEANS THAT WHEN RIVER LEVELS
RISE...MANY PEOPLE WILL BE AFFECTED AT THE SAME TIME. THE RISING
RIVER WATERS CAN BECOME DESTRUCTIVE...AND EVEN DEADLY.
SIGNIFICANT...WIDESPREAD RIVER FLOODS HAVE OCCURRED IN PENNSYLVANIA
ALMOST EVERY YEAR.
WHAT CAUSES RIVER FLOODS?
GENERALLY...RIVER FLOODS HAPPEN DUE TO PROLONGED PERIODS OF
WIDESPREAD HEAVY RAINFALL.
OUR RIVERS CAN FLOOD ANYTIME OF THE YEAR. IN SPRING AND
SUMMER...COMPLEXES OF SLOW MOVING THUNDERSTORMS CAN CAUSE THE RIVERS
TO FLOOD. DURING LATE SUMMER AND FALL...HEAVY RAIN FROM TROPICAL
STORMS AND HURRICANES ARE THE BIGGEST CAUSE OF RIVER FLOODING.
SOMETIMES...AN EXTENSIVE SNOW MELT OCCURS AT THE SAME TIME AS HEAVY
RAIN. THIS IS ESPECIALLY TRUE IN LATE WINTER AND EARLY SPRING WHEN
THE SNOW PACK OF THE PREVIOUS WINTER MELTS AWAY. THE DESTRUCTIVE
FLOODING OF JANUARY 1996 WAS ONE SUCH SITUATION WHERE SNOW MELT AND
HEAVY RAIN COMBINE TO PUSH RIVER LEVELS EVEN HIGHER.
RIVER FLOODING CAN RESULT IN WIDESPREAD PROPERTY DAMAGE AND MAY
RESULT IN LOSS OF LIFE. MORE THAN 50 PERCENT OF THE DEATHS
ASSOCIATED WITH FLOODING ARE AUTOMOBILE RELATED.
WHAT DOES A FLOOD WATCH MEAN?
A FLOOD WATCH MEANS THERE IS POTENTIAL FOR FLOODING TO OCCUR...
NOT THAT RIVER FLOODING IS OCCURRING. A FLOOD WATCH IS TYPICALLY
ISSUED FOR AN AREA MANY COUNTIES IN SIZE...AND IS USUALLY ISSUED 12
TO 24 HOURS BEFORE FLOODING IS EXPECTED TO START. WITH THE ADVANCE
NOTICE OF A WATCH...YOU WILL HAVE MORE TIME TO PREPARE FOR THE
FLOODING.
WHAT YOU SHOULD DO WHEN A FLOOD WATCH IS ISSUED?
GO ABOUT YOUR NORMAL ACTIVITIES...BUT MAKE PERIODIC CHECKS OF NOAA
WEATHER RADIO OR OTHER MEDIA OUTLETS FOR UPDATES AND POSSIBLE FLOOD
WARNINGS. LISTEN FOR RIVER LEVEL FORECASTS FROM THE NATIONAL WEATHER
SERVICE. GET READY TO MOVE YOUR PERSONAL PROPERTY OUT OF THE AREAS
THAT ARE KNOWN TO FLOOD. IF YOU LIVE IN THE FLOOD PLAIN...BE
PREPARED TO EVACUATE IF ORDERED TO DO SO.
IF YOU LIVE OR WORK IN AN AREA WHICH IS PRONE TO FLOODING... HAVE A
SAFE EVACUATION ROUTE TO USE IF FLOODING OCCURS. MAKE SURE EVERYONE
IN YOUR HOME OR OFFICE KNOWS WHERE TO GO IF FLOODING OCCURS. MOVE UP
TO HIGHER GROUND TO ESCAPE FLOOD WATERS. KEEP A BATTERY OPERATED
RADIO...AND SEVERAL WORKING FLASHLIGHTS AVAILABLE. TAKE PRECAUTIONS
TO SECURE YOUR PROPERTY.
WHAT DOES A RIVER FLOOD WARNING MEAN?
A RIVER FLOOD WARNING MEANS THAT RIVER LEVELS WILL EXCEED FLOOD
STAGE AT CERTAIN POINTS ALONG OUR LARGER RIVERS...LIKE THE
SUSQUEHANNA AND JUNIATA RIVERS.
BECAUSE RIVER FLOODS TAKE LONGER TO DEVELOP THAN FLASH FLOODING
DOES...RIVER FLOODS MAY NOT POSE AS MUCH OF A THREAT TO LIFE...
BUT RIVER FLOODS CAN TAKE A MUCH LARGER TOLL ON PROPERTY AND
INFRASTRUCTURE.
WHAT SHOULD YOU DO WHEN A RIVER FLOOD WARNING IS ISSUED?
GATHER ALL NECESSARY ITEMS...INCLUDING MEDICINE AND CLOTHING...IN
THE EVENT THAT YOU CANNOT RETURN HOME FOR SEVERAL DAYS. MAKE
ARRANGEMENTS TO PROTECT YOUR PROPERTY BY MOVING YOUR VALUABLES TO
HIGHER GROUND...OR TO AN UPPER LEVEL OF YOUR HOME.
OBEY EVACUATION ORDERS FROM EMERGENCY MANAGEMENT OR LOCAL LAW
ENFORCEMENT OFFICIALS...AVOIDING ANY ROADS THAT ARE OR MAY BE
COVERED WITH WATER.
FOR ADDITIONAL INFORMATION ON RIVER FLOODING AND SEVERE WEATHER
CHECK OUT OUR WEB SITE AT:
https://weather.gov
OUR WEATHER SAFETY TOPIC FOR FRIDAY WILL BE...
SKYWARN SEVERE WEATHER SPOTTERS.