Public Information Statement
Issued by NWS Caribou, ME

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000 NOUS41 KCAR 201020 PNSCAR PNSCAR MEZ001>006-010-011-015>017-029>032-210200- PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE CARIBOU ME 620 AM EDT MON JUL 20 2015 ...HURRICANE AWARENESS WEEK 2015... TROPICAL STORMS AND HURRICANES THE TERM "TROPICAL CYCLONE" IS A GENERIC NAME GIVEN TO A LOW PRESSURE SYSTEM THAT GENERALLY FORMS IN THE TROPICS AND IS ACCOMPANIED BY SHOWERS AND THUNDERSTORMS AND A COUNTERCLOCKWISE WIND CIRCULATION. DEPENDING ON THE STRENGTH OF THE WINDS IN THE CIRCULATION, TROPICAL CYCLONES ARE FURTHER DIVIDED INTO TROPICAL DEPRESSIONS, TROPICAL STORMS, AND HURRICANES. THE TROPICAL CYCLONES THAT AFFECT EASTERN NORTH AMERICA GENERALLY FORM IN EITHER THE TROPICAL ATLANTIC OCEAN, THE CARIBBEAN SEA, OR IN THE GULF OF MEXICO. THE THREE MAIN CONDITIONS WHICH FAVOR TROPICAL CYCLONE DEVELOPMENT ARE (1) WARM OCEAN WATERS, (2) ATMOSPHERIC MOISTURE, AND (3) RELATIVELY LIGHT WINDS ALOFT. IN ADDITION, AN ATMOSPHERIC DISTURBANCE, CALLED A TROPICAL WAVE, IS NEEDED TO INITIATE THE DEVELOPMENT THE COUNTER-CLOCKWISE WIND CIRCULATION. IF THE FAVORABLE CONDITIONS PERSIST FOR A SUFFICIENT AMOUNT OF TIME, THE TROPICAL DISTURBANCE CAN STRENGTHEN TO A TROPICAL DEPRESSION, TROPICAL STORM, OR HURRICANE. WHEN THE WINDS IN A TROPICAL CYCLONE REACH TROPICAL STORM STRENGTH (39 MPH, 34 KT), THE STORM IS "NAMED". TROPICAL CYCLONES ARE CLASSIFIED AS FOLLOWS: TROPICAL CYCLONE TERMS: TROPICAL DEPRESSION - AN ORGANIZED SYSTEM OF CLOUDS AND THUNDERSTORMS WITH A DEFINED SURFACE CIRCULATION AND MAXIMUM SUSTAINED WINDS OF 38 MPH (33 KNOTS) OR LESS. TROPICAL STORM - AN ORGANIZED SYSTEM OF STRONG THUNDERSTORMS WITH A DEFINED SURFACE CIRCULATION AND MAXIMUM SUSTAINED WINDS OF 39-73 MPH (34-63 KNOTS). HURRICANE - AN INTENSE TROPICAL WEATHER SYSTEM OF STRONG THUNDERSTORMS WITH A WELL-DEFINED SURFACE CIRCULATION AND MAXIMUM SUSTAINED WINDS OF 74 MPH (64 KNOTS) OR HIGHER. HURRICANES ARE ALSO CLASSIFIED INTO DIFFERENT CATEGORIES BASED ON STRENGTH. TROPICAL CYCLONE DESCRIPTION: THE WELL-DEVELOPED HURRICANE CONSISTS OF AN EYE, AN EYEWALL, AND SPIRAL BANDS OF SHOWERS AND THUNDERSTORMS. IN THE EYE, WINDS ARE RELATIVE CALM AND THERE IS A GENTLE SINKING MOTION IN THE ATMOSPHERE WHICH LEADS TO MOSTLY CLEAR SKIES. SURROUNDING THE EYE IS THE EYEWALL WHICH CONTAINS THE MOST VIOLENT WINDS, THE MOST INTENSE SHOWERS AND THUNDERSTORMS IN THE HURRICANE, AND CAN CONTAIN TORNADOES. THE WINDS IN THE EYEWALL ALSO HAVE THE GREATEST POTENTIAL FOR CAUSING A DEADLY STORM SURGE. OUTSIDE THE EYEWALL, SPIRAL BANDS OF SHOWERS AND THUNDERSTORMS ROTATE AROUND THE STORM. THESE BANDS OF SHOWERS AND THUNDERSTORMS CAN ALSO BE VERY INTENSE, CAN MOVE INTO AN AREA VERY RAPIDLY, AND ARE THE MOST LIKELY AREA IN THE HURRICANE FOR TORNADOES TO FORM. TROPICAL CYCLONE THREATS: HURRICANES AND TROPICAL STORMS BRING WITH THEM FOUR MAIN THREATS: HIGH WINDS, COASTAL STORM SURGE, INLAND FRESH WATER FLOODING, AND TORNADOES. THESE WILL BE DISCUSSED IN GREATER DETAIL IN FORTHCOMING STATEMENTS. WHILE HURRICANE SEASON LASTS FROM JUNE THROUGH NOVEMBER, THE PEAK OF THE SEASON IS FROM MID-AUGUST THROUGH OCTOBER. EACH YEAR, AN AVERAGE OF TEN TROPICAL STORMS DEVELOP OVER THE ATLANTIC OCEAN, CARIBBEAN SEA, AND GULF OF MEXICO. MANY OF THESE STORMS REMAIN OVER THE OCEAN, AND AN AVERAGE OF SIX OF THESE STORMS BECOME HURRICANES EACH YEAR. DURING AN AVERAGE 3-YEAR PERIOD, ROUGHLY FIVE HURRICANES STRIKE THE UNITED STATES COASTLINE, KILLING APPROXIMATELY 45 PEOPLE (AN AVERAGE OF 15.5 PER YEAR) ANYWHERE FROM TEXAS TO MAINE. OF THESE, TWO ARE TYPICALLY "MAJOR" OR "INTENSE" HURRICANES (WINDS GREATER THAN 110 MPH). NOW IS THE TIME TO PREPARE FOR HURRICANES AND TROPICAL STORMS: HTTP://WWW.NHC.NOAA.GOV/PREPARE/ HTTP://WWW.READY.GOV/EVACUATING-YOURSELF-AND-YOUR-FAMILY $$

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