Pacific Hurricane Outlook & Discussion
Expires:No;;892513 ABPZ20 KNHC 031136 TWOEP TROPICAL WEATHER OUTLOOK NWS NATIONAL HURRICANE CENTER MIAMI FL 500 AM PDT WED AUG 3 2016 For the eastern North Pacific...east of 140 degrees west longitude: The National Hurricane Center is issuing advisories on Tropical Storm Howard, located more than 1450 miles west of the southern tip of the Baja California peninsula, and on recently upgraded Tropical Storm Ivette, located about 850 miles southwest of the southern tip of the Baja California peninsula. An area of low pressure could form near the southern coast of Mexico late this weekend in association with the remnants of Atlantic Tropical Storm Earl after it moves across southern Mexico. Some subsequent development of this system is possible while it moves west-northwestward near the southwestern coast of Mexico early next week. * Formation chance through 48 hours...low...near 0 percent * Formation chance through 5 days...low...30 percent && Public Advisories on Tropical Storm Ivette are issued under WMO header WTPZ35 KNHC and under AWIPS header MIATCPEP5. Forecast/Advisories on Tropical Storm Ivette are issued under WMO header WTPZ25 KNHC and under AWIPS header MIATCMEP5. $$ Forecaster Berg
Active tropical cyclones in the Atlantic, Caribbean, and the Gulf of Mexico
Atlantic Tropical Weather Outlook-
ABNT20 KNHC 250536
TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT THU AUG 25 2016
For the North Atlantic...Caribbean Sea and the Gulf of Mexico:
The National Hurricane Center is issuing advisories on recently
upgraded Hurricane Gaston, located about 1215 miles west of the Cabo
A broad area of low pressure located about 200 miles northwest of
Puerto Rico is producing gale-force winds over water to the north
of the Virgin Islands and Puerto Rico. However, satellite images
indicate that the shower activity remains disorganized, and the low
continues to lack a well-defined center. Although upper-level winds
are only marginally conducive for development, this system could
still become a tropical cyclone during the next couple of days.
Environmental conditions have the potential to become more conducive
for development over the weekend when the system is near the central
or northwestern Bahamas.
Regardless of development, gusty winds and heavy rains are likely to
occur over portions of the Leeward Islands, Puerto Rico, Hispaniola,
and the southeastern and central Bahamas during the next couple of
days, which could lead to possible flash floods and mudslides.
Please consult products issued by your local meteorological offices
and High Seas Forecasts from the National Weather Service for
further details. A NOAA Hurricane Hunter aircraft is scheduled to
investigate this system later this morning.
Interests in the northwestern Bahamas and Florida should monitor the
progress of this disturbance. Because of the large uncertainties
regarding this system's development and future track, it is too
early to speculate on what specific impacts might occur in the
northwestern Bahamas, Florida or beyond.
* Formation chance through 48 hours...medium...50 percent
* Formation chance through 5 days...high...80 percent
High Seas Forecasts issued by the National Weather Service can be
found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and
on the Web at http://www.opc.ncep.noaa.gov/shtml/NFDHSFAT1.shtml.
Summary for Hurricane GASTON (AT2/AL072016)- ...GASTON EXPECTED TO WEAKEN BACK TO A TROPICAL STORM LATER TODAY... As of 5:00 AM AST Thu Aug 25 the center of GASTON was located near 19.5, -43.3 with movement NW at 17 mph. The minimum central pressure was 988 mb with maximum sustained winds of about 75 mph.
Hurricane GASTON Public Advisory Number 11-Issued at 500 AM AST THU AUG 25 2016
000 WTNT32 KNHC 250834 TCPAT2 BULLETIN HURRICANE GASTON ADVISORY NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072016 500 AM AST THU AUG 25 2016 ...GASTON EXPECTED TO WEAKEN BACK TO A TROPICAL STORM LATER TODAY... SUMMARY OF 500 AM AST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...19.5N 43.3W ABOUT 1225 MI...1970 KM E OF THE LEEWARD ISLANDS MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 17 MPH...28 KM/H MINIMUM CENTRAL PRESSURE...988 MB...29.18 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ At 500 AM AST (0900 UTC), the center of Hurricane Gaston was located near latitude 19.5 North, longitude 43.3 West. Gaston is moving toward the northwest near 17 mph (28 km/h), and this general motion is expected to continue through Friday. A turn toward the west-northwest is forecast Friday night. Data from a NASA/NOAA Global Hawk unmanned aircraft indicate that maximum sustained winds are near 75 mph (120 km/h) with higher gusts. Some weakening is forecast during the next day or so. Hurricane-force winds extend outward up to 25 miles (35 km) from the center, and tropical-storm-force winds extend outward up to 90 miles (150 km). The estimated minimum central pressure from the aircraft data is 988 mb (29.18 inches). HAZARDS AFFECTING LAND ---------------------- None. NEXT ADVISORY ------------- Next complete advisory at 1100 AM AST. $$ Forecaster Berg
Hurricane GASTON Forecast Advisory Number 11-Issued at 0900 UTC THU AUG 25 2016
000 WTNT22 KNHC 250833 TCMAT2 HURRICANE GASTON FORECAST/ADVISORY NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072016 0900 UTC THU AUG 25 2016 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. HURRICANE CENTER LOCATED NEAR 19.5N 43.3W AT 25/0900Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 15 KT ESTIMATED MINIMUM CENTRAL PRESSURE 988 MB MAX SUSTAINED WINDS 65 KT WITH GUSTS TO 80 KT. 64 KT....... 20NE 0SE 0SW 0NW. 50 KT....... 40NE 40SE 20SW 30NW. 34 KT....... 80NE 80SE 40SW 50NW. 12 FT SEAS..150NE 90SE 60SW 120NW. 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 19.5N 43.3W AT 25/0900Z AT 25/0600Z CENTER WAS LOCATED NEAR 18.9N 42.7W FORECAST VALID 25/1800Z 21.1N 44.8W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 40NE 40SE 20SW 30NW. 34 KT... 90NE 90SE 40SW 60NW. FORECAST VALID 26/0600Z 23.4N 46.9W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 50NE 30SE 0SW 30NW. 34 KT...100NE 90SE 40SW 70NW. FORECAST VALID 26/1800Z 25.3N 49.4W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 50NE 30SE 0SW 40NW. 34 KT...110NE 90SE 50SW 80NW. FORECAST VALID 27/0600Z 26.7N 52.0W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 50NE 40SE 0SW 40NW. 34 KT...120NE 90SE 70SW 100NW. FORECAST VALID 28/0600Z 29.1N 56.0W MAX WIND 70 KT...GUSTS 85 KT. 50 KT... 60NE 60SE 40SW 50NW. 34 KT...140NE 120SE 90SW 110NW. 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 29/0600Z 31.0N 58.0W MAX WIND 80 KT...GUSTS 100 KT. OUTLOOK VALID 30/0600Z 32.5N 57.5W MAX WIND 85 KT...GUSTS 105 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 19.5N 43.3W NEXT ADVISORY AT 25/1500Z $$ FORECASTER BERG
Hurricane GASTON Forecast Discussion Number 11-Issued at 500 AM AST THU AUG 25 2016
000 WTNT42 KNHC 250834 TCDAT2 HURRICANE GASTON DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072016 500 AM AST THU AUG 25 2016 For much of yesterday afternoon and evening, the NASA/NOAA Global Hawk unmanned aircraft flew a mission through Gaston. On the aircraft's last pass through the storm, it released a dropsonde at 0243 UTC that measured a mean boundary layer wind of 80 kt and an average wind of 77 kt in the lowest 150 m of the sounding near the center of the cyclone. These numbers both support an intensity of 65 kt, and consequently Gaston was upgraded to a hurricane. The sonde reported a minimum pressure of 995 mb with a 69-kt surface wind, which equates to a central pressure of about 988 mb. Despite Gaston becoming a hurricane, microwave data indicate that the cyclone is tilted due to 20-25 kt of west-southwesterly shear. The shear is expected to increase further during the next 12-24 hours when Gaston moves around the eastern side of an upper-level low, and as a result, the hurricane is forecast to weaken back to a tropical storm later today. The shear is then forecast to subside in about 48 hours, and with sea surface temperatures expected to increase, Gaston is likely to reintensify during the latter part of the forecast period. The updated NHC forecast is higher than the previous forecast during the first 48 hours primarily to account for the higher initial intensity. After 48 hours, the official forecast is unchanged and closely follows the SHIPS model and the ICON intensity consensus. Gaston continues to move northwestward, or 310 degrees at 15 kt, along the southwestern edge of a mid-tropospheric high. A fairly quick northwestward motion should continue for the next 36 hours, with a turn toward the west-northwest expected by 48 hours when Gaston moves around the north side of the aforementioned mid- to upper-level low. Gaston is then expected to recurve toward the north-northeast by day 5 as it moves through a break in the ridge and toward the mid-latitude westerlies. The track models are in agreement on this general scenario, although the ECMWF model is a little bit slower and to the east of the other models, showing a sharper turn by day 5. The new NHC track forecast is therefore a little east of the previous forecast on days 4 and 5 and lies closest to the HWRF and the TVCN multi-model consensus. FORECAST POSITIONS AND MAX WINDS INIT 25/0900Z 19.5N 43.3W 65 KT 75 MPH 12H 25/1800Z 21.1N 44.8W 60 KT 70 MPH 24H 26/0600Z 23.4N 46.9W 55 KT 65 MPH 36H 26/1800Z 25.3N 49.4W 55 KT 65 MPH 48H 27/0600Z 26.7N 52.0W 60 KT 70 MPH 72H 28/0600Z 29.1N 56.0W 70 KT 80 MPH 96H 29/0600Z 31.0N 58.0W 80 KT 90 MPH 120H 30/0600Z 32.5N 57.5W 85 KT 100 MPH $$ Forecaster Berg
Hurricane GASTON Wind Speed Probabilities Number 11-Issued at 0900 UTC THU AUG 25 2016
000 FONT12 KNHC 250834 PWSAT2 HURRICANE GASTON WIND SPEED PROBABILITIES NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072016 0900 UTC THU AUG 25 2016 AT 0900Z THE CENTER OF HURRICANE GASTON WAS LOCATED NEAR LATITUDE 19.5 NORTH...LONGITUDE 43.3 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 65 KTS...75 MPH...120 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 06Z 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 06Z THU 18Z THU 06Z FRI 18Z FRI 06Z SAT 06Z SUN 06Z MON PERIODS TO TO TO TO TO TO TO 18Z THU 06Z FRI 18Z FRI 06Z SAT 06Z SUN 06Z MON 06Z TUE FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT BERMUDA 34 X X( X) X( X) X( X) X( X) 5( 5) 7(12) BERMUDA 50 X X( X) X( X) X( X) X( X) 1( 1) 2( 3) $$ FORECASTER BERG
Hurricane GASTON Graphics-
5-Day Uncertainty Track last updated Thu, 25 Aug 2016 08:36:16 GMT
Wind Speed Probabilities last updated Thu, 25 Aug 2016 09:05:39 GMT