Home › forecast
 

Keywords :   


Tag: forecast

Hurricane Larry Forecast Discussion Number 17

2021-09-04 22:56:16| National Hurricane Center (Atlantic)

Issued at 500 PM AST Sat Sep 04 2021 000 WTNT42 KNHC 042056 TCDAT2 Hurricane Larry Discussion Number 17 NWS National Hurricane Center Miami FL AL122021 500 PM AST Sat Sep 04 2021 Larry remains a formidable hurricane this afternoon. Both visible and infrared satellite bands show the hurricane has a well-defined and warm eye (greater than 10 C) surrounded by a cold ring of eyewall convection (-60 to -70 C). An AMSR2 microwave pass received at 1630 UTC showed the well-defined eye of Larry, though the 89 GHz channel hinted that the eyewall was weaker on its eastern side. Taking a look at the high-density atmospheric motion vectors (AMVs), available thanks to a GOES-16 1-minute updating domain over Larry, there is some restriction of Larry's outflow to the southwest. Flight-level wind data from the NASA-DC8 aircraft conducting a research mission around Larry also showed some light southwesterly flow between 10-20 kt just a few degrees to the south and west of the storm center. These data suggest that the upper-level wind environment is not as pristine as earlier suggested by SHIPS guidance, with the southwesterly flow likely restricting Larry's outflow in that quadrant. The SAB/TAFB subjective Dvorak intensity estimates are unchanged from this morning, and the latest UW-CIMSS ADT and SATCON estimates have also plateaued in the 105-110 kt range. Therefore, Larry was maintained as a 110 kt hurricane this advisory. Larry remains on a west-northwest track this afternoon, but a bit slower at 300/12 kt. There has been little change to the track philosophy over the next several days, as the guidance is in good agreement that Larry will maintain a continued west-northwest heading while gradually slowing down as it rounds the southern periphery of a large mid-level ridge. However, there has been a notable eastward shift in the track guidance in the short-term. The latest ECMWF run, which had previously been on the southwest side of the track guidance envelope, is now very similar or even a tad east of the latest GFS run. This shift has also resulted in an eastward adjustment in the consensus aids this afternoon. The latest NHC track forecast was adjusted a bit to the right early on, but not as far right as the HCCA and TVCA aids. After 72 hours, the track guidance actually converges very close to the previous track forecast, and few changes were needed after this time period. Based on this forecast, Larry will continue moving across the central Atlantic in the coming days, and be approaching Bermuda from the southeast in the day 4 to 5 forecast period. The existence of some light upper-level southwesterly flow ahead of Larry today was bit of a surprise, since the SHIPS guidance from the last few days suggested the shear-vector would be out of the east and weak. Indeed, the latest ECMWF-SHIPS guidance now shows moderate southwesterly vertical wind shear beginning earlier, and peaking between 20-25 knots in 36 to 48 hours. While the GFS-SHIPS shear remains much lower, given what I'm seeing from the latest upper-level flow in front of Larry, the ECMWF seems closer to correct. For this reason, the latest NHC intensity guidance now shows a bit of weakening after 24 hours, when the shear magnitude is expected to peak as the hurricane interacts with a large tropical upper-tropospheric trough (TUTT) located to its northwest. However, Larry has a large and vertically-deep circulation, and ultimately it will win the battle against the more vertically shallow TUTT, which is forecast to cut off and move away from the hurricane's expansive upper-level outflow. By 60 hours, this change in the synoptic pattern should once again reduce the vertical wind shear over Larry, and it will have a chance to achieve a secondary peak between the 60-84 hour time-frame. However, eyewall replacement cycles could also occur at any time over the next 2-5 days, providing additional intensity fluctuations that make this a challenging intensity forecast. The latest NHC intensity forecast is lower than the previous one, but still remains higher than the latest HCCA consensus aid. Regardless of the details, Larry is expected to remain a large major hurricane over the next 3-4 days. Key Messages: 1. Large swells generated by Larry are expected to first reach the Lesser Antilles on Sunday and will spread to portions of the Greater Antilles, the Bahamas, and Bermuda Monday and Tuesday. Significant swells will likely reach the east coast of the United States and Atlantic Canada around midweek. These swells will likely cause life-threatening surf and rip current conditions, and beachgoers and other interests along these coasts are urged to follow the advice of lifeguards and local officials through the upcoming week. 2. Larry is forecast to approach Bermuda during the next several days, possibly as a major hurricane, bringing a risk of strong winds, heavy rainfall, and coastal flooding to the island by the middle of next week. While it is too soon to determine the magnitude of these hazards and potential impacts on Bermuda, interests there should monitor changes to the forecast during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 04/2100Z 17.4N 47.1W 110 KT 125 MPH 12H 05/0600Z 18.4N 48.6W 115 KT 130 MPH 24H 05/1800Z 19.8N 50.6W 120 KT 140 MPH 36H 06/0600Z 21.0N 52.3W 115 KT 130 MPH 48H 06/1800Z 22.2N 54.0W 110 KT 125 MPH 60H 07/0600Z 23.4N 55.6W 110 KT 125 MPH 72H 07/1800Z 24.7N 57.0W 115 KT 130 MPH 96H 08/1800Z 28.3N 59.9W 110 KT 125 MPH 120H 09/1800Z 33.4N 61.9W 95 KT 110 MPH $$ Forecaster Papin

Tags: number discussion larry forecast

 

Hurricane Larry Forecast Advisory Number 17

2021-09-04 22:46:47| National Hurricane Center (Atlantic)

Issued at 2100 UTC SAT SEP 04 2021 958 WTNT22 KNHC 042046 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 2100 UTC SAT SEP 04 2021 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. HURRICANE CENTER LOCATED NEAR 17.4N 47.1W AT 04/2100Z POSITION ACCURATE WITHIN 15 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 12 KT ESTIMATED MINIMUM CENTRAL PRESSURE 958 MB MAX SUSTAINED WINDS 110 KT WITH GUSTS TO 135 KT. 64 KT....... 40NE 30SE 25SW 35NW. 50 KT....... 70NE 60SE 30SW 60NW. 34 KT.......140NE 120SE 70SW 130NW. 12 FT SEAS..300NE 240SE 240SW 300NW. 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 17.4N 47.1W AT 04/2100Z AT 04/1800Z CENTER WAS LOCATED NEAR 17.1N 46.5W FORECAST VALID 05/0600Z 18.4N 48.6W MAX WIND 115 KT...GUSTS 140 KT. 64 KT... 45NE 35SE 30SW 40NW. 50 KT... 80NE 60SE 40SW 60NW. 34 KT...140NE 130SE 80SW 120NW. FORECAST VALID 05/1800Z 19.8N 50.6W MAX WIND 120 KT...GUSTS 145 KT. 64 KT... 50NE 45SE 40SW 50NW. 50 KT... 80NE 70SE 60SW 70NW. 34 KT...140NE 140SE 90SW 130NW. FORECAST VALID 06/0600Z 21.0N 52.3W MAX WIND 115 KT...GUSTS 140 KT. 64 KT... 60NE 50SE 40SW 50NW. 50 KT... 80NE 70SE 60SW 70NW. 34 KT...150NE 140SE 100SW 140NW. FORECAST VALID 06/1800Z 22.2N 54.0W MAX WIND 110 KT...GUSTS 135 KT. 64 KT... 60NE 50SE 40SW 50NW. 50 KT... 80NE 80SE 60SW 70NW. 34 KT...150NE 140SE 100SW 130NW. FORECAST VALID 07/0600Z 23.4N 55.6W MAX WIND 110 KT...GUSTS 135 KT. 50 KT... 90NE 90SE 70SW 80NW. 34 KT...160NE 150SE 120SW 130NW. FORECAST VALID 07/1800Z 24.7N 57.0W MAX WIND 115 KT...GUSTS 140 KT. 50 KT... 90NE 90SE 70SW 80NW. 34 KT...170NE 160SE 120SW 130NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 08/1800Z 28.3N 59.9W MAX WIND 110 KT...GUSTS 135 KT. OUTLOOK VALID 09/1800Z 33.4N 61.9W MAX WIND 95 KT...GUSTS 115 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 17.4N 47.1W NEXT ADVISORY AT 05/0300Z $$ FORECASTER PAPIN

Tags: number larry advisory forecast

 
 

Hurricane Larry Forecast Discussion Number 16

2021-09-04 16:59:11| National Hurricane Center (Atlantic)

Issued at 1100 AM AST Sat Sep 04 2021 000 WTNT42 KNHC 041459 TCDAT2 Hurricane Larry Discussion Number 16 NWS National Hurricane Center Miami FL AL122021 1100 AM AST Sat Sep 04 2021 Overnight and this morning, Larry appears to have gone through a rather quick eyewall replacement cycle (ERC). The most recent 1000 UTC GMI microwave pass suggests that Larry now has a much larger eye and surrounding eyewall, with less evidence of concentric bands as noted yesterday. On geostationary satellite the larger eye is also becoming apparent on visible and infrared channels, though some left over inner eyewall debris remains. Consistent with the larger eye, an ASCAT-B pass received at 1226 UTC indicated that the 34-, 50-, and 64-kt wind radii have expanded with Larry this morning. While the most recent SAB and TAFB subjective Dvorak intensity estimates have remain at 90 kt and 100 kt respectively, the objective estimates are higher, with an earlier UW-CIMSS SATCON estimate up to 112 kt, though it has recently been adjusted lower. With the eye beginning to clear out on the most recent satellite images, I am favoring the higher objective estimates, bringing Larry up to 110 kt for this advisory. Larry's track has remained fairly steady toward the west-northwest, but just a touch slower and more poleward with the latest estimated motion at 300/13 kt. This west-northwest motion is expected to continue for the next several days with only a very gradual poleward bend as Larry remains positioned to the south of an expansive mid-level ridge extending westward ahead of Larry's expected path. As has been the case the last several days, the track guidance is in excellent agreement over the next 36-48 hours with more spread becoming apparent thereafter. As discussed yesterday, the increase in spread in the latter portion of the forecast appears to be related to how much mid-level ridging stays north of Larry. The ECMWF and its ensembles maintain more ridging that results in a slower and more westward track, while the GFS and its ensembles place more ridging east of Larry that results in a faster more eastward track. The UKMET favors a solution closer to the ECMWF while the Canadian favors a solution closer to the GFS. For now, the latest NHC track has elected to remain close to the HFIP corrected consensus approach (HCCA) which slightly favors the ECMWF solution over the GFS. This latest track forecast is quite similar to the previous one, but just a touch slower. Based on this forecast, Larry will continue moving across the central Atlantic in the coming days, and be approaching the latitude of Bermuda by the end of the forecast period. Conditions continue to remain favorable for additional intensification over the next few days, with vertical wind shear remaining under 10 kts, sea-surface temperatures gradually increasing, and mid-level relatively humidity staying fairly moist. However, by 48 hours, Larry will be impinging on the eastern edge of a large upper-level mid-oceanic trough, which could result in an increase in westerly vertical wind shear over the hurricane. However, the models handle Larry's interaction with this synoptic feature differently. The GFS suggests this upper-level trough will fracture to the west fairly quickly, keeping a more favorable upper-level pattern over Larry, while the ECMWF has a stronger trough that takes longer to give way to Larry's upper-level outflow, providing more westerly shear over the hurricane. Additional eyewall replacement cycles are also possible in the coming days, which could result in additional intensity fluctuations that are challenging to predict ahead of time. For now, the latest NHC intensity forecast keeps Larry intensifying over the next 24-36 hours, with only a very gradual decay thereafter due to the somewhat less favorable dynamical environment. The latest intensity forecast remains on the high end of the guidance, noting that there still remain higher outliers making Larry stronger than the 125 kt peak intensity (HAFS-B, COAMPS-TC). Regardless of the details, Larry is expected to remain a large major hurricane through the forecast period. Significant ocean swells generated by Larry's growing wind field are expected to reach the Lesser Antilles tomorrow, and then spread westward to portions of the Greater Antilles, the Bahamas, and Bermuda on Monday and Tuesday. These swells could cause life-threatening rip currents and high surf conditions. Large swells are also likely to spread to the east coast of the United States by midweek. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 16.8N 45.8W 110 KT 125 MPH 12H 05/0000Z 17.7N 47.5W 115 KT 130 MPH 24H 05/1200Z 19.1N 49.6W 120 KT 140 MPH 36H 06/0000Z 20.3N 51.5W 125 KT 145 MPH 48H 06/1200Z 21.5N 53.2W 120 KT 140 MPH 60H 07/0000Z 22.6N 54.8W 120 KT 140 MPH 72H 07/1200Z 23.8N 56.4W 115 KT 130 MPH 96H 08/1200Z 27.0N 59.4W 110 KT 125 MPH 120H 09/1200Z 31.6N 62.0W 100 KT 115 MPH $$ Forecaster Papin

Tags: number discussion larry forecast

 

Hurricane Larry Forecast Advisory Number 16

2021-09-04 16:46:39| National Hurricane Center (Atlantic)

Issued at 1500 UTC SAT SEP 04 2021 000 WTNT22 KNHC 041446 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 16 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 1500 UTC SAT SEP 04 2021 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. HURRICANE CENTER LOCATED NEAR 16.8N 45.8W AT 04/1500Z POSITION ACCURATE WITHIN 15 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 13 KT ESTIMATED MINIMUM CENTRAL PRESSURE 958 MB MAX SUSTAINED WINDS 110 KT WITH GUSTS TO 135 KT. 64 KT....... 40NE 30SE 20SW 30NW. 50 KT....... 70NE 60SE 30SW 60NW. 34 KT.......140NE 120SE 70SW 130NW. 12 FT SEAS..300NE 240SE 210SW 270NW. 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 16.8N 45.8W AT 04/1500Z AT 04/1200Z CENTER WAS LOCATED NEAR 16.5N 45.2W FORECAST VALID 05/0000Z 17.7N 47.5W MAX WIND 115 KT...GUSTS 140 KT. 64 KT... 45NE 35SE 30SW 40NW. 50 KT... 80NE 60SE 40SW 60NW. 34 KT...140NE 120SE 80SW 120NW. FORECAST VALID 05/1200Z 19.1N 49.6W MAX WIND 120 KT...GUSTS 145 KT. 64 KT... 50NE 50SE 40SW 50NW. 50 KT... 80NE 70SE 60SW 70NW. 34 KT...150NE 140SE 100SW 130NW. FORECAST VALID 06/0000Z 20.3N 51.5W MAX WIND 125 KT...GUSTS 150 KT. 64 KT... 60NE 50SE 40SW 55NW. 50 KT... 80NE 70SE 60SW 80NW. 34 KT...150NE 140SE 100SW 140NW. FORECAST VALID 06/1200Z 21.5N 53.2W MAX WIND 120 KT...GUSTS 145 KT. 64 KT... 60NE 55SE 45SW 55NW. 50 KT... 90NE 80SE 60SW 80NW. 34 KT...150NE 150SE 110SW 130NW. FORECAST VALID 07/0000Z 22.6N 54.8W MAX WIND 120 KT...GUSTS 145 KT. 50 KT... 90NE 90SE 70SW 80NW. 34 KT...160NE 150SE 120SW 130NW. FORECAST VALID 07/1200Z 23.8N 56.4W MAX WIND 115 KT...GUSTS 140 KT. 50 KT...100NE 90SE 80SW 80NW. 34 KT...170NE 160SE 120SW 130NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 08/1200Z 27.0N 59.4W MAX WIND 110 KT...GUSTS 135 KT. OUTLOOK VALID 09/1200Z 31.6N 62.0W MAX WIND 100 KT...GUSTS 120 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 16.8N 45.8W NEXT ADVISORY AT 04/2100Z $$ FORECASTER PAPIN

Tags: number larry advisory forecast

 

Hurricane Larry Forecast Advisory Number 15

2021-09-04 10:30:29| National Hurricane Center (Atlantic)

Issued at 0900 UTC SAT SEP 04 2021 887 WTNT22 KNHC 040830 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 0900 UTC SAT SEP 04 2021 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. HURRICANE CENTER LOCATED NEAR 16.3N 44.6W AT 04/0900Z POSITION ACCURATE WITHIN 15 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 295 DEGREES AT 14 KT ESTIMATED MINIMUM CENTRAL PRESSURE 965 MB MAX SUSTAINED WINDS 100 KT WITH GUSTS TO 120 KT. 64 KT....... 30NE 25SE 15SW 25NW. 50 KT....... 70NE 60SE 30SW 60NW. 34 KT.......130NE 110SE 60SW 120NW. 12 FT SEAS..300NE 270SE 210SW 270NW. 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 16.3N 44.6W AT 04/0900Z AT 04/0600Z CENTER WAS LOCATED NEAR 16.0N 44.0W FORECAST VALID 04/1800Z 17.2N 46.5W MAX WIND 110 KT...GUSTS 135 KT. 64 KT... 35NE 30SE 20SW 30NW. 50 KT... 70NE 60SE 40SW 60NW. 34 KT...130NE 120SE 70SW 130NW. FORECAST VALID 05/0600Z 18.4N 48.6W MAX WIND 115 KT...GUSTS 140 KT. 64 KT... 40NE 35SE 30SW 40NW. 50 KT... 70NE 60SE 50SW 60NW. 34 KT...140NE 130SE 80SW 130NW. FORECAST VALID 05/1800Z 19.7N 50.7W MAX WIND 120 KT...GUSTS 145 KT. 64 KT... 45NE 40SE 30SW 50NW. 50 KT... 70NE 60SE 50SW 70NW. 34 KT...140NE 130SE 90SW 130NW. FORECAST VALID 06/0600Z 21.0N 52.6W MAX WIND 120 KT...GUSTS 145 KT. 64 KT... 50NE 40SE 30SW 50NW. 50 KT... 80NE 70SE 60SW 70NW. 34 KT...150NE 140SE 90SW 130NW. FORECAST VALID 06/1800Z 22.0N 54.3W MAX WIND 115 KT...GUSTS 140 KT. 50 KT... 80NE 70SE 60SW 70NW. 34 KT...150NE 140SE 100SW 130NW. FORECAST VALID 07/0600Z 23.3N 56.0W MAX WIND 115 KT...GUSTS 140 KT. 50 KT... 80NE 80SE 60SW 80NW. 34 KT...150NE 150SE 110SW 130NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 08/0600Z 26.1N 59.0W MAX WIND 110 KT...GUSTS 135 KT. OUTLOOK VALID 09/0600Z 30.6N 62.0W MAX WIND 105 KT...GUSTS 130 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 16.3N 44.6W NEXT ADVISORY AT 04/1500Z $$ FORECASTER CANGIALOSI

Tags: number larry advisory forecast

 

Sites : [65] [66] [67] [68] [69] [70] [71] [72] [73] [74] [75] [76] [77] [78] [79] [80] [81] [82] [83] [84] next »