What is a Hurricane?
A hurricane is a type of tropical cyclone, which is a generic term for a low pressure system that generally forms in the tropics. The cyclone is accompanied by thunderstorms and, in the Northern Hemisphere, a counterclockwise circulation of winds near the earth's surface. Tropical cyclones are classified as follows:
An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 mph (33 kt) or less. Sustained winds are a 1-minute average wind measured at about 33 ft (10 meters) above the surface. While 1 knot = 1 nautical mile per hour or 1.15 statute miles per hour and is abbreviated as "kt".
An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39-73 mph (34-63 kt)
An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 mph (64 kt) or higher
Hurricanes are categorized according to the strength of their winds using the Saffir-Simpson Hurricane Scale. A Category 1 storm has the lowest wind speeds, while a Category 5 hurricane has the strongest. These are relative terms, because lower category storms can sometimes inflict greater damage than higher category storms, depending on where they strike and the particular hazards they bring. In fact, tropical storms can also produce significant damage and loss of life, mainly due to flooding.
When the the winds from these storms reach 39 mph (34 kts), the cyclones are given names. Years ago, an international committee developed names for Atlantic cyclones (The History of Naming Hurricanes). In 1979 a six year rotating list of Atlantic storm names was adopted — alternating between male and female hurricane names. Storm names are used to facilitate geographic referencing, for warning services, for legal issues, and to reduce confusion when two or more tropical cyclones occur at the same time. Through a vote of the World Meteorological Organization Region IV Subcommittee, Atlantic cyclone names are retired usually when hurricanes result in substantial damage or death or for other special circumstances.
(Thanks to the NHC.)
Active tropical cyclones in the Atlantic, Caribbean, and the Gulf of Mexico
Atlantic Tropical Weather Outlook-
ABNT20 KNHC 171719
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT WED SEP 17 2014
For the North Atlantic...Caribbean Sea and the Gulf of Mexico:
The National Hurricane Center is issuing advisories on Hurricane
Edouard, located several hundred miles east-northeast of Bermuda.
A large area of disorganized showers and thunderstorms near the west
coast of Africa is associated with a tropical wave. Some slow
development of this system is possible over the next several days
while the disturbance moves west-northwestward or northwestward at
about 10 mph over the far eastern Atlantic Ocean.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.
Summary for Hurricane EDOUARD (AT1/AL062014)- ...EDOUARD MOVING RAPIDLY NORTHEASTWARD OVER THE NORTH ATLANTIC... As of 5:00 PM AST Wed Sep 17 the center of EDOUARD was located near 37.8, -51.2 with movement NE at 26 mph. The minimum central pressure was 958 mb with maximum sustained winds of about 85 mph.
Hurricane EDOUARD Public Advisory Number 26-Issued at 500 PM AST WED SEP 17 2014
000 WTNT31 KNHC 172035 TCPAT1 BULLETIN HURRICANE EDOUARD ADVISORY NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 500 PM AST WED SEP 17 2014 ...EDOUARD MOVING RAPIDLY NORTHEASTWARD OVER THE NORTH ATLANTIC... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...37.8N 51.2W ABOUT 855 MI...1380 KM ENE OF BERMUDA ABOUT 1220 MI...1960 KM W OF FAYAL ISLAND IN THE WESTERN AZORES MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H PRESENT MOVEMENT...NE OR 55 DEGREES AT 26 MPH...43 KM/H MINIMUM CENTRAL PRESSURE...958 MB...28.29 INCHES WATCHES AND WARNINGS -------------------- THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 500 PM AST...2100 UTC...THE CENTER OF HURRICANE EDOUARD WAS LOCATED NEAR LATITUDE 37.8 NORTH...LONGITUDE 51.2 WEST. EDOUARD IS MOVING TOWARD THE NORTHEAST NEAR 26 MPH...43 KM/H. A GRADUAL TURN TOWARD THE EAST IS EXPECTED BY LATE TOMORROW...WITH A TURN TOWARD THE EAST-SOUTHEAST AT A DECREASING FORWARD SPEED ANTICIPATED BY LATE FRIDAY. MAXIMUM SUSTAINED WINDS HAVE DECREASED TO NEAR 85 MPH...140 KM/H... WITH HIGHER GUSTS. GRADUAL WEAKENING IS FORECAST DURING THE NEXT 48 HOURS AND EDOUARD IS EXPECTED TO LOSE HURRICANE STRENGTH ON THURSDAY...AND BECOME A POST-TROPICAL CYCLONE BY LATE FRIDAY. HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 80 MILES...130 KM...FROM THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 230 MILES...370 KM. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 958 MB...28.29 INCHES. HAZARDS AFFECTING LAND ---------------------- SURF...SWELLS FROM EDOUARD WILL AFFECT PORTIONS OF THE EAST COAST OF THE UNITED STATES NORTH OF FLORIDA BEGINNING TODAY. THESE SWELLS WILL LIKELY CAUSE LIFE-THREATENING RIP CURRENT CONDITIONS ALONG MOST OF THE UNITED STATES EAST COAST FOR THE NEXT COUPLE OF DAYS. PLEASE SEE PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE OFFICE FOR MORE DETAILS. NEXT ADVISORY ------------- NEXT COMPLETE ADVISORY...1100 PM AST. $$ FORECASTER BLAKE
Hurricane EDOUARD Forecast Advisory Number 26-Issued at 2100 UTC WED SEP 17 2014
000 WTNT21 KNHC 172034 TCMAT1 HURRICANE EDOUARD FORECAST/ADVISORY NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 2100 UTC WED SEP 17 2014 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. HURRICANE CENTER LOCATED NEAR 37.8N 51.2W AT 17/2100Z POSITION ACCURATE WITHIN 10 NM PRESENT MOVEMENT TOWARD THE NORTHEAST OR 55 DEGREES AT 23 KT ESTIMATED MINIMUM CENTRAL PRESSURE 958 MB EYE DIAMETER 15 NM MAX SUSTAINED WINDS 75 KT WITH GUSTS TO 90 KT. 64 KT....... 40NE 70SE 50SW 0NW. 50 KT....... 80NE 120SE 100SW 50NW. 34 KT.......150NE 200SE 150SW 90NW. 12 FT SEAS..230NE 310SE 270SW 350NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 37.8N 51.2W AT 17/2100Z AT 17/1800Z CENTER WAS LOCATED NEAR 37.2N 52.4W FORECAST VALID 18/0600Z 39.4N 47.3W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 35NE 70SE 40SW 0NW. 50 KT... 70NE 110SE 80SW 40NW. 34 KT...140NE 180SE 150SW 90NW. FORECAST VALID 18/1800Z 40.4N 42.5W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 60NE 80SE 60SW 40NW. 34 KT...120NE 150SE 130SW 90NW. FORECAST VALID 19/0600Z 40.2N 39.4W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 0NE 50SE 50SW 0NW. 34 KT... 90NE 100SE 80SW 60NW. FORECAST VALID 19/1800Z 40.0N 38.0W...POST-TROPICAL MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 60NE 60SE 60SW 40NW. FORECAST VALID 20/1800Z 40.0N 34.0W...POST-TROPICAL MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 0NE 50SE 50SW 0NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 200 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 21/1800Z 38.0N 31.0W...POST-TROPICAL MAX WIND 30 KT...GUSTS 40 KT. OUTLOOK VALID 22/1800Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 37.8N 51.2W NEXT ADVISORY AT 18/0300Z $$ FORECASTER BLAKE
Hurricane EDOUARD Forecast Discussion Number 26-Issued at 500 PM AST WED SEP 17 2014
000 WTNT41 KNHC 172035 TCDAT1 HURRICANE EDOUARD DISCUSSION NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 500 PM AST WED SEP 17 2014 An earlier NOAA Hurricane Hunter aircraft research mission showed a maximum 700 mb flight-level wind of 91 kt, with peak SFMR winds of 71 kt. Since the plane left a few hours ago, the satellite appearance of Edouard has become less organized, with warming convection in the eyewall and a cooling eye. The initial intensity is set to 75 kt for this advisory, a blend of the SFMR data and the higher satellite classifications. A combination of cooling waters and increasing shear should keep Edouard on a general weakening trend throughout the 120-hour period. Post-tropical transition is indicated in the latest NHC forecast at 48 hours due to Edouard moving over cold waters with strong shear. The cyclone is expected to dissipate by day 5, which is in good agreement with almost all of the global models. Edouard is moving faster to the northeast, now 055/23. A gradual turn to the east is expected, along with some decrease in forward speed by late tomorrow, due to Edouard moving becoming more steered by the subtropical ridge rather than faster mid-latitude westerlies. Edouard (or its remnants) should turn southeastward in a few days while it moves around a large trough over the eastern Atlantic. Although the general synoptic pattern has not changed, the track guidance has taken a notable eastward shift in this cycle, apparently due to the weaker low-level circulation decoupling from the mid-level northerly flow. Consequently, the latest forecast is shifted quite a bit to the east at day 4, although there probably won't be much of Edouard by that point. FORECAST POSITIONS AND MAX WINDS INIT 17/2100Z 37.8N 51.2W 75 KT 85 MPH 12H 18/0600Z 39.4N 47.3W 70 KT 80 MPH 24H 18/1800Z 40.4N 42.5W 60 KT 70 MPH 36H 19/0600Z 40.2N 39.4W 50 KT 60 MPH 48H 19/1800Z 40.0N 38.0W 40 KT 45 MPH...POST-TROPICAL 72H 20/1800Z 40.0N 34.0W 35 KT 40 MPH...POST-TROPICAL 96H 21/1800Z 38.0N 31.0W 30 KT 35 MPH...POST-TROPICAL 120H 22/1800Z...DISSIPATED $$ Forecaster Blake
Hurricane EDOUARD Wind Speed Probabilities Number 26-Issued at 2100 UTC WED SEP 17 2014
000 FONT11 KNHC 172035 PWSAT1 HURRICANE EDOUARD WIND SPEED PROBABILITIES NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 2100 UTC WED SEP 17 2014 AT 2100Z THE CENTER OF HURRICANE EDOUARD WAS LOCATED NEAR LATITUDE 37.8 NORTH...LONGITUDE 51.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 75 KTS...85 MPH...140 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 18Z WED AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 64 KT ARE SHOWN WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 18Z WED 06Z THU 18Z THU 06Z FRI 18Z FRI 18Z SAT 18Z SUN PERIODS TO TO TO TO TO TO TO 06Z THU 18Z THU 06Z FRI 18Z FRI 18Z SAT 18Z SUN 18Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT SANTA CRUZ AZO 34 X X( X) X( X) 1( 1) 12(13) 12(25) X(25) SANTA CRUZ AZO 50 X X( X) X( X) X( X) 2( 2) 2( 4) X( 4) $$ FORECASTER BLAKE
Hurricane EDOUARD Graphics-
5-Day Uncertainty Track last updated Wed, 17 Sep 2014 20:36:40 GMT
Wind Speed Probabilities last updated Wed, 17 Sep 2014 21:06:45 GMT