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Hurricane EDOUARD Forecast Discussion Number 15

2014-09-15 04:56:02| National Hurricane Center (Atlantic)

Issued at 1100 PM AST SUN SEP 14 2014 000 WTNT41 KNHC 150255 TCDAT1 HURRICANE EDOUARD DISCUSSION NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 1100 PM AST SUN SEP 14 2014 Edouard's cloud pattern has not changed much in organization this evening. Although the eye had become better defined and warmer, it has recently disappeared. Convective cloud top temperatures in the central dense overcast have also warmed during the past several hours. There is some evidence that dry air may be wrapping into portions of the inner core of the hurricane. Dvorak intensity estimates were a consensus T4.5/77 kt from TAFB and SAB, so the initial intensity estimate is held at 75 kt. The environment ahead of Edouard is likely to become more conducive for intensification during the next day or two. While traversing warm waters, the shear is forecast to reach a minimum in 36-48 hours. The only inhibiting factor would seem to be dry environmental air wrapping around the circulation. After achieving a peak intensity near the point of recurvature, gradual weakening is likely to commence while the hurricane moves toward decreasing sea surface temperatures. A considerable increase in southwesterly shear and dramatically cooler waters should hasten the weakening trend beyond 72 hours. Edouard's interaction with a shortwave trough moving across Atlantic Canada in 4-5 days should lead to the beginning of extratropical transition at that time, but the guidance is not clear cut on a completion of this process by day 5. The intensity forecast is near or just above the multi-model consensus through 72 hours and near or a little below it at the end of the forecast period. The initial motion estimate is 305/13 kt. Edouard should continue on a northwestward heading on the south side of subtropical ridge until the ridge retreats eastward in a day or so. This change in the steering pattern should result in Edouard's turning sharply northward in about 36 hours. The hurricane should then be captured by a strong mid-latitude westerly flow and accelerate northeastward in 3-4 days, and turn generally eastward with a decrease in forward speed by day 5. The track guidance has shifted significantly to the left this cycle, and the official forecast track has been moved in that direction. The new track forecast, however, lies on the far right side of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 26.2N 53.3W 75 KT 85 MPH 12H 15/1200Z 27.2N 54.9W 80 KT 90 MPH 24H 16/0000Z 28.6N 56.4W 90 KT 105 MPH 36H 16/1200Z 30.2N 57.1W 100 KT 115 MPH 48H 17/0000Z 32.4N 56.5W 95 KT 110 MPH 72H 18/0000Z 37.4N 51.3W 80 KT 90 MPH 96H 19/0000Z 41.2N 42.7W 60 KT 70 MPH...POST-TROPICAL 120H 20/0000Z 41.2N 36.0W 45 KT 50 MPH...POST-TROPICAL $$ Forecaster Kimberlain

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Remnants of SIXTEEN-E Forecast Discussion Number 15

2014-09-15 04:33:00| National Hurricane Center (East Pacific)

Issued at 800 PM PDT SUN SEP 14 2014 000 WTPZ41 KNHC 150232 TCDEP1 REMNANTS OF SIXTEEN-E DISCUSSION NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL EP162014 800 PM PDT SUN SEP 14 2014 The last few hours of visible imagery this evening suggested that the circulation of the depression was becoming elongated along a north-south axis and losing definition, with definitive westward-moving cloud elements near the alleged center hard to identify. In addition, the decaying circulation was becoming increasingly separated from a limited patch of deep convection. Based on these observations, this will be the last advisory on this system. The remnants of the depression are expected to turn northeastward and become fully absorbed within the circulation of Hurricane Odile over the next day or so. For additional information on the remnants of the depression, please see High Seas Forecasts issued by the National Weather Service under AWIPS header NFDHSFEPI and WMO header FZPN01 KWBC. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 16.3N 112.3W 30 KT 35 MPH...DISSIPATED 12H 15/1200Z...DISSIPATED $$ Forecaster Franklin

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Hurricane ODILE Forecast Discussion Number 19

2014-09-14 22:58:59| National Hurricane Center (East Pacific)

Issued at 200 PM PDT SUN SEP 14 2014 000 WTPZ45 KNHC 142058 TCDEP5 HURRICANE ODILE DISCUSSION NUMBER 19 NWS NATIONAL HURRICANE CENTER MIAMI FL EP152014 200 PM PDT SUN SEP 14 2014 Odile has been undergoing a concentric eyewall cycle since the previous advisory, and an Air Force Reserve reconnaissance aircraft has found an inner eye of about 10-12 nmi diameter and an outer eye of 36 nmi diameter. Despite this normally unfavorable inner-core structure, the central pressure has decreased to 922 mb and the 700- mb maximum flight-level winds have increased from 122 kt to 134 kt during the two passes through the northeastern quadrant. The highest SFMR winds measured thus far have only been around 100 kt. However, given the strong flight-level winds and the very low central pressure, the initial intensity has only been decreased slightly to 110 kt, which is a blend of the SFMR winds and surface-adjusted flight-level winds. Major Hurricane Odile is moving north-northwestward or 330/13 kt. There is no significant change to the previous forecast track reasoning. A strong deep-layer ridge over Mexico is expected to keep Odile moving north-northwestward to northwestward during the next 72 hours. After that time, the cyclone is forecast to rapidly weaken, with the low-level circulation decoupling from the mid- and upper-level circulations. By Days 4 and 5, the shallow cyclone is expected to become stationary or drift eastward within weak low-level westerly flow. The models are tightly clustered through 72 hours, but diverge significantly after that with the ECMWF model taking Odile intact across northern Baja and into the southwestern U.S., while the GFS model keeps Odile's remnant low west of Baja California. The official forecast leans heavily toward the GFS model on Days 4 and 5 due to the expected rapid weakening of Odile. The NHC track forecast has been shifted slightly closer to Baja California, but not as far eastward as the consensus model TCVE. Given that the central pressure has continued to decrease, and satellite imagery and recon data suggest that the concentric eyewall cycle could be coming to an end, some re-strengthening overnight during the convective maximum period is a very distinct possibility. During the 12-36 hour time frame, interaction with the mountainous terrain of Baja California should induce gradual weakening. By 48 hours and beyond, rapid weakening is expected due to sharply decreasing sea-surface temperatures and increasing southwesterly wind shear. The NHC intensity forecast is similar to the previous advisory and is close to the consensus model IVCN. Users are reminded to not focus on the exact forecast track, as strong winds and heavy rainfall extend well away from the center of Odile. In addition, moisture from a disturbance over northeastern Mexico and the Pacific ITCZ is forecast to be advected by Odile's circulation northwestward across Mexico into the southwestern United States by early next week. This could result in heavy rains and life-threatening flash flooding in those areas. Please see information from your local weather office for more details. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 21.1N 108.9W 110 KT 125 MPH 12H 15/0600Z 22.6N 110.1W 115 KT 135 MPH 24H 15/1800Z 24.2N 111.8W 105 KT 120 MPH 36H 16/0600Z 25.4N 112.9W 90 KT 105 MPH 48H 16/1800Z 26.5N 113.9W 70 KT 80 MPH 72H 17/1800Z 27.8N 115.3W 45 KT 50 MPH 96H 18/1800Z 28.3N 115.4W 30 KT 35 MPH 120H 19/1800Z 28.5N 115.1W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Stewart

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Hurricane EDOUARD Forecast Discussion Number 14

2014-09-14 22:32:29| National Hurricane Center (Atlantic)

Issued at 500 PM AST SUN SEP 14 2014 000 WTNT41 KNHC 142032 TCDAT1 HURRICANE EDOUARD DISCUSSION NUMBER 14 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 500 PM AST SUN SEP 14 2014 Edouard has become better organized this afternoon. The eye of the hurricane has again made an appearance in satellite images, and deep convection surrounding the center has increased in intensity and coverage during the past few hours. NOAA hurricane hunters investigated the system this afternoon and found maximum flight- level winds of 90 kt and SFMR winds of 68 kt. These data and the consensus Dvorak classifications of 4.5/77 kt at 1800 UTC, support raising the initial wind speed to 75 kt. Additional strengthening seems likely during the next couple of days while the hurricane remains over warm water and the shear lessens somewhat. The only potential inhibiting factor is the influence of dry air that is seen wrapping into the eastern side of the circulation. Steady weakening is expected beyond a couple of days when the cyclone moves over much cooler water and into a stable air mass, which will eventually cause extratropical transition to occur in about 5 days. Little change was made to the previous intensity forecast, with the current forecast showing a peak intensity in about two days followed by a steady decline after that. The hurricane is moving west-northwestward or 300/13 kt, steered by a subtropical ridge centered to its north. This ridge is expected to weaken and shift eastward, and that should cause Edouard to gradually turn toward the north during the next couple of days. By mid-week, Edouard is expected to become embedded in the mid-latitude zonal flow that will cause the cyclone to turn toward the east. The NHC track forecast is nudged a little to the west for the next few days, toward the latest guidance, and is similar to the previous advisory at 96 and 120 h. The NASA Global Hawk is currently dropping numerous dropsondes into and around the circulation of Edouard. These data will be useful in analyzing the intensity and structure of the hurricane, and should help the models better initialize the cyclone and its environment. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 25.4N 52.1W 75 KT 85 MPH 12H 15/0600Z 26.4N 53.9W 85 KT 100 MPH 24H 15/1800Z 27.8N 55.7W 90 KT 105 MPH 36H 16/0600Z 29.3N 56.8W 100 KT 115 MPH 48H 16/1800Z 31.2N 56.9W 100 KT 115 MPH 72H 17/1800Z 35.9N 53.3W 90 KT 105 MPH 96H 18/1800Z 40.1N 45.0W 70 KT 80 MPH 120H 19/1800Z 41.0N 37.5W 55 KT 65 MPH...POST-TROP/EXTRATROP $$ Forecaster Cangialosi

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Hurricane ODILE Forecast Discussion Number 18

2014-09-14 16:56:58| National Hurricane Center (East Pacific)

Issued at 800 AM PDT SUN SEP 14 2014 000 WTPZ45 KNHC 141456 TCDEP5 HURRICANE ODILE DISCUSSION NUMBER 18 NWS NATIONAL HURRICANE CENTER MIAMI FL EP152014 800 AM PDT SUN SEP 14 2014 After rapidly strengthening during the past 24 hours, it appears that the intensity of Odile has leveled off for now. Microwave images indicate that the cyclone has a double eyewall structure, with the inner eyewall surrounding the 10-15 n mi diameter eye, and the outer one located about 40-50 n mi from the center. Satellite intensity estimates remain 115 kt, and that value is kept for the initial wind speed. An Air Force reconnaissance aircraft is scheduled to investigate Odile later today, and should provide a better assessment of the strength and structure of this hurricane. The major hurricane is moving northwestward at about 12 kt, steered by a ridge located to its northeast. A continued northwestward motion is expected during the next 3 to 4 days with a gradual decrease in forward speed due to a strengthening trough off the U.S. west coast. By the end of the forecast period, the shallow cyclone is expected to become stationary or drift eastward in the low-level flow. The models are tightly clustered for most of the forecast period, and the NHC track forecast is close to the consensus aids. This track takes the center of Odile very near the southern Baja California west coast later today, and then just offshore and parallel to the coast for the next several days. The observed concentric eyewall structure, which is fairly common in mature hurricanes like Odile, typically causes intensity fluctuations in the short term, and the NHC intensity forecast shows little change in strength during the next 24 hours. Odile will be moving over cool water and into a drier airmass in 36 to 48 hours. These unfavorable thermodynamic conditions should cause the cyclone to quickly weaken. The NHC intensity forecast is similar to the previous one, and not too different than the intensity model consensus, IVCN. Users are reminded to not focus on the exact forecast track, as strong winds and heavy rainfall extend well away from the center of Odile. In addition, moisture from a disturbance over northeastern Mexico and the Pacific ITCZ is forecast to be advected by Odile's circulation northwestward across Mexico into the southwestern United States by early next week. This could result in heavy rains and life-threatening flash flooding in those areas. Please see information from your local weather office for more details. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 20.0N 108.2W 115 KT 135 MPH 12H 15/0000Z 21.7N 109.6W 120 KT 140 MPH 24H 15/1200Z 23.5N 111.4W 120 KT 140 MPH 36H 16/0000Z 24.9N 112.8W 100 KT 115 MPH 48H 16/1200Z 25.9N 113.8W 85 KT 100 MPH 72H 17/1200Z 27.5N 115.5W 55 KT 65 MPH 96H 18/1200Z 28.1N 116.2W 40 KT 45 MPH 120H 19/1200Z 28.3N 116.0W 30 KT 35 MPH $$ Forecaster Cangialosi

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