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 222339
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED OCT 22 2014
For the North Atlantic...Caribbean Sea and the Gulf of Mexico:
The National Hurricane Center is issuing advisories on Tropical
Depression Nine, located over the eastern Bay of Campeche.
Shower activity associated with a large non-tropical low located
over the northeastern Atlantic Ocean a few hundred miles south of
the western Azores has diminished. Environmental conditions are
becoming less conducive, and the low is expected to weaken over the
next few days while it meanders. Additional information on this
system can be found in High Seas Forecasts issued by Meteo France.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...near 0 percent.
Satellite imagery and surface observations indicate that a
non-tropical low pressure area is developing over the southeastern
Gulf of Mexico. The low is expected to move east-northeastward,
and development into a subtropical or tropical cyclone is
unlikely due to unfavorable upper-level winds. Regardless of
development, this system is likely to cause heavy rainfall and
locally gusty winds over western Cuba, the southern portion of the
Florida Peninsula, and the Florida Keys during the next couple of
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...near 0 percent.
Public Advisories on Tropical Depression Nine are issued under WMO
header WTNT34 KNHC and under AWIPS header MIATCPAT4.
Forecast/Advisories on Tropical Depression Nine are issued under WMO
header WTNT24 KNHC and under AWIPS header MIATCMAT4.
High Seas Forecasts issued by Meteo France can be found under WMO
header FQNT50 LFPW.
Summary for Post-Tropical Cyclone NINE (AT4/AL092014)- ...DEPRESSION MOVES INLAND AND BECOMES A REMNANT LOW... ...RAINFALL THREAT TO CONTINUE... As of 10:00 PM CDT Wed Oct 22 the center of NINE was located near 18.9, -90.9 with movement ESE at 6 mph. The minimum central pressure was 1004 mb with maximum sustained winds of about 30 mph.
Post-Tropical Cyclone NINE Public Advisory Number 5-Issued at 1000 PM CDT WED OCT 22 2014
000 WTNT34 KNHC 230236 TCPAT4 BULLETIN POST-TROPICAL CYCLONE NINE ADVISORY NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092014 1000 PM CDT WED OCT 22 2014 ...DEPRESSION MOVES INLAND AND BECOMES A REMNANT LOW... ...RAINFALL THREAT TO CONTINUE... SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...18.9N 90.9W ABOUT 75 MI...120 KM SSW OF CAMPECHE MEXICO MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H PRESENT MOVEMENT...ESE OR 105 DEGREES AT 6 MPH...9 KM/H MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES WATCHES AND WARNINGS -------------------- THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 1000 PM CDT...0300 UTC...THE CENTER OF POST-TROPICAL CYCLONE NINE WAS LOCATED NEAR LATITUDE 18.9 NORTH...LONGITUDE 90.9 WEST. THE POST-TROPICAL CYCLONE IS MOVING TOWARD THE EAST-SOUTHEAST NEAR 6 MPH ...9 KM/H...AND THIS MOTION IS EXPECTED TO CONTINUE DURING THE NEXT 48 HOURS. ON THE FORECAST TRACK...THE CENTER OF THE CYCLONE WILL MOVE ACROSS THE SOUTHERN PORTION OF THE YUCATAN PENINSULA DURING THE NEXT COUPLE OF DAYS. MAXIMUM SUSTAINED WINDS ARE NEAR 30 MPH...45 KM/H...WITH HIGHER GUSTS. WEAKENING IS FORECAST WHILE THE LOW MOVES OVER LAND DURING THE NEXT 48 HOURS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB...29.65 INCHES. HAZARDS AFFECTING LAND ---------------------- RAINFALL...THE CYCLONE IS EXPECTED TO PRODUCE TOTAL RAINFALL ACCUMULATIONS OF 5 TO 10 INCHES ACROSS THE YUCATAN PENINSULA OF MEXICO...WITH A MAXIMUM OF 15 INCHES POSSIBLE. THESE RAINFALL AMOUNTS MAY PRODUCE LIFE-THREATENING FLASH FLOODS. NEXT ADVISORY ------------- THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON THIS SYSTEM. $$ FORECASTER BROWN
Post-Tropical Cyclone NINE Forecast Advisory Number 5-Issued at 0300 UTC THU OCT 23 2014
000 WTNT24 KNHC 230235 TCMAT4 POST-TROPICAL CYCLONE NINE FORECAST/ADVISORY NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092014 0300 UTC THU OCT 23 2014 POST-TROPICAL CYCLONE CENTER LOCATED NEAR 18.9N 90.9W AT 23/0300Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE EAST-SOUTHEAST OR 105 DEGREES AT 5 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1004 MB MAX SUSTAINED WINDS 25 KT WITH GUSTS TO 35 KT. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 18.9N 90.9W AT 23/0300Z AT 23/0000Z CENTER WAS LOCATED NEAR 19.1N 91.2W FORECAST VALID 23/1200Z 18.8N 90.3W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 24/0000Z 18.5N 89.5W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 24/1200Z 18.2N 88.9W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 25/0000Z 17.8N 88.2W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. FORECAST VALID 26/0000Z 17.3N 87.5W...POST-TROP/REMNT LOW MAX WIND 20 KT...GUSTS 30 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 200 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 27/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 18.9N 90.9W THIS IS THE LAST FORECAST/ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON THIS SYSTEM. $$ FORECASTER BROWN
Post-Tropical Cyclone NINE Forecast Discussion Number 5-Issued at 1000 PM CDT WED OCT 22 2014
000 WTNT44 KNHC 230236 TCDAT4 POST-TROPICAL CYCLONE NINE DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092014 1000 PM CDT WED OCT 22 2014 Radar data from Mexico indicates that the cyclone moved inland between Campeche and Ciudad del Carmen just after 0000 UTC this evening. Surface and aircraft reconnaissance data suggest that the maximum winds had decreased to around 25 kt and that the minimum pressure was 1004 mb when the depression crossed the coast. The system has not produced a significant area of organized deep convection since late this morning and it is therefore being declared a remnant low at this time. The low is expected to weaken during the next couple of days while it moves over the Yucatan Peninsula. If the low emerges over the northwestern Caribbean Sea, dry air and westerly shear are expected to prevent regeneration. The new NHC forecast follows the last couple runs of the GFS and call for dissipation in 3 to 4 days. The cyclone is moving east-southeastward at about 5 kt. A slow east-southeast to southeast motion is expected to continue during the next few days. The updated NHC track has been shifted a little left of the previous track to be closer the latest GFS guidance and the multi-model consensus. Rains currently affecting western Cuba and south Florida are not directly related to this system. This is the last advisory issued by the National Hurricane Center on this system. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 18.9N 90.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 12H 23/1200Z 18.8N 90.3W 20 KT 25 MPH...POST-TROP/REMNT LOW 24H 24/0000Z 18.5N 89.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 36H 24/1200Z 18.2N 88.9W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 25/0000Z 17.8N 88.2W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 26/0000Z 17.3N 87.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 27/0000Z...DISSIPATED $$ Forecaster Brown
Post-Tropical Cyclone NINE Wind Speed Probabilities Number 5-Issued at 0300 UTC THU OCT 23 2014
000 FONT14 KNHC 230236 PWSAT4 POST-TROPICAL CYCLONE NINE WIND SPEED PROBABILITIES NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092014 0300 UTC THU OCT 23 2014 AT 0300Z THE CENTER OF POST-TROPICAL CYCLONE NINE WAS LOCATED NEAR LATITUDE 18.9 NORTH...LONGITUDE 90.9 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 25 KTS...30 MPH...45 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 00Z THU 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 00Z THU 12Z THU 00Z FRI 12Z FRI 00Z SAT 00Z SUN 00Z MON PERIODS TO TO TO TO TO TO TO 12Z THU 00Z FRI 12Z FRI 00Z SAT 00Z SUN 00Z MON 00Z TUE FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT BELIZE 34 X 3( 3) 3( 6) 2( 8) 4(12) X(12) X(12) PUERTO BARRIOS 34 X 1( 1) X( 1) 1( 2) 2( 4) X( 4) X( 4) GUANAJA 34 X X( X) 1( 1) 1( 2) 3( 5) X( 5) X( 5) $$ FORECASTER BROWN
Post-Tropical Cyclone NINE Graphics-
5-Day Uncertainty Track last updated Thu, 23 Oct 2014 02:37:00 GMT
Wind Speed Probabilities last updated Thu, 23 Oct 2014 03:04:43 GMT