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Hurricane EDOUARD Forecast Discussion Number 13

2014-09-14 16:51:30| National Hurricane Center (Atlantic)

Issued at 1100 AM AST SUN SEP 14 2014 000 WTNT41 KNHC 141451 TCDAT1 HURRICANE EDOUARD DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 1100 AM AST SUN SEP 14 2014 Edouard's inner core convective pattern has continued to improve since the previous advisory, with a ring of deep convection surrounding a brief appearance of a 20 nmi diameter eye around 1200 UTC. Since that time, the eye has become cloud-covered with cirrus from a strong convective burst in the western eyewall. A 0924 UTC Windsat microwave overpass revealed good low-level structure and a 15-20 nmi diameter eye. Satellite intensity estimates are a consensus T4.5/77 kt from TAFB and SAB, and UW-CIMSS ADT values have been T4.4/75 kt for the past few hours. However, due to the eye recently becoming cloud-filled, the initial intensity is only being increased to 70 kt, which still makes Edouard the fourth hurricane of the 2014 Atlantic season. Edouard has made slight wobble to the right, possibly due to the formation of the eye, but a 12-hour-average yields a motion of about 305/14 kt. A deep-layer subtropical ridge along 30N-32N latitude is expected to steer the hurricane northwestward today, followed by a turn to the north on Monday and Tuesday. On Wednesday, the cyclone is expected to accelerate to the northeast ahead of a strong mid-tropospheric trough that is forecast to move off of the U.S. east coast. By Days 4 and 5, Edouard is expected to get caught up into the strong mid-latitude westerlies and turn toward the east-northeast. The NHC model guidance is in excellent on this developing steering pattern, and the official forecast closely follows the previous forecast track and the consensus model TVCA. Given the well-developed structure noted in the Windsat imagery, a very favorable poleward outflow pattern forecast to develop by all of the models, and anomalously warm SSTs of 29.5C ahead of the cyclone, there appears to be no physical reason why Edouard should not continue to strengthen and eventually become a major hurricane over the next 2 days or so. The only inhibiting factor could be the dry mid-level air surrounding the cyclone, and that is the only reason why rapid intensification is not being forecast at this time. By Day 4 and beyond, Edouard will be moving over sub-24C SSTs and encountering vertical wind shear greater than 25 kt, which is expected to induce significant weakening. By Day 5, Edouard is forecast to transition to an extratropical cyclone as the system becomes embedded within the strong mid-latitude westerlies. The official intensity forecast follows the trend of the previous forecast and the SHIPS model, except that the timing of the peak intensity has been moved forward by 24 hours, in order to coincide with the time that Edouard will be over the warmest water and in the lowest shear conditions. A NOAA hurricane hunter aircraft is currently conducting a research mission into Edouard. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 24.7N 50.7W 70 KT 80 MPH 12H 15/0000Z 25.8N 52.5W 80 KT 90 MPH 24H 15/1200Z 27.1N 54.6W 90 KT 105 MPH 36H 16/0000Z 28.5N 56.1W 100 KT 115 MPH 48H 16/1200Z 30.1N 56.7W 105 KT 120 MPH 72H 17/1200Z 34.5N 54.6W 95 KT 110 MPH 96H 18/1200Z 39.4N 47.1W 75 KT 85 MPH 120H 19/1200Z 41.7N 38.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Stewart

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Hurricane ODILE Forecast Discussion Number 17

2014-09-14 11:04:36| National Hurricane Center (East Pacific)

Issued at 200 AM PDT SUN SEP 14 2014 000 WTPZ45 KNHC 140904 TCDEP5 HURRICANE ODILE DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP152014 200 AM PDT SUN SEP 14 2014 Odile has continue to rapidly strengthen overnight with the eye becoming more distinct in infrared satellite imagery. Recent microwave imagery shows a well-defined eye, and a long convection band that appears to be beginning of a concentric eyewall. Subjective Dvorak intensity estimates from TAFB and SAB are 115 kt, and the latest UW-CIMSS ADT estimate is around 105 kt. Based on these data, the initial wind speed is increased to 115 kt. Odile is the seventh major hurricane to form in the eastern North Pacific basin this season, which is only one shy of the record since the advent of satellite imagery. The hurricane is moving north-northwestward a little faster than before, with an initial motion of 330 degrees at 13 kt. Odile should turn northwestward today as it is steered around the western portion of a strengthening ridge over the southern United States. The track guidance is tightly clustered during the first 2 to 3 days of the forecast period and the NHC forecast is near the middle of the guidance envelope. The updated NHC track is very close to the previous advisory through 72 hours. Later in the period, the GFS and ECMWF show the cyclone continuing northwestward at a slower forward speed, while some of the models indicate a more north-northwestward or northward motion at days 4 and 5. The NHC track leans toward the ECMWF and GFS solutions late in the forecast period. Warm water and low shear during the next 12 hours should allow for some additional strengthening, but the rate of intensification is expected to slow later today. In addition during the next day or so, an eyewall replacement cycle could cause some fluctuations in intensity. By Monday, the hurricane will be moving over cooler water and weakening should begin. Rapid weakening is likely in a couple of days as Odile moves over even colder waters and into a more stable airmass as well as potential land interactions. The updated NHC forecast shows a higher peak intensity due to the higher initial intensity. After 24 hours, the NHC forecast is similar to the previous advisory and a little below the intensity consensus. 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 14/0900Z 19.1N 107.3W 115 KT 135 MPH 12H 14/1800Z 20.7N 108.6W 130 KT 150 MPH 24H 15/0600Z 22.7N 110.5W 125 KT 145 MPH 36H 15/1800Z 24.3N 112.1W 105 KT 120 MPH 48H 16/0600Z 25.6N 113.4W 90 KT 105 MPH 72H 17/0600Z 27.3N 115.3W 60 KT 70 MPH 96H 18/0600Z 28.2N 116.3W 45 KT 50 MPH 120H 19/0600Z 28.5N 116.5W 30 KT 35 MPH $$ Forecaster Brown

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Tropical Storm EDOUARD Forecast Discussion Number 12

2014-09-14 10:57:25| National Hurricane Center (Atlantic)

Issued at 500 AM AST SUN SEP 14 2014 000 WTNT41 KNHC 140857 TCDAT1 TROPICAL STORM EDOUARD DISCUSSION NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 500 AM AST SUN SEP 14 2014 Edouard continues to gradually intensify, as a tightly curved band has wrapped around the cyclone's center. Dvorak classifications from both TAFB and SAB are a 4.0, or 65 kt, while the CIMSS Advanced Dvorak Technique is substantially lower. The current intensity of Edouard is assessed as a high-end tropical storm at 60 kt, but the system may already be a hurricane given the uncertainties. The vertical shear - primarily induced by a large tropical upper tropospheric trough to its west-southwest - has begun to relax, now that Edouard has moved poleward of the trough axis. Vertical shear predicted by the global models should further weaken to less than 10 kt from 24 through 72 hours. This along with quite warm 29C waters is likely to lead to continued intensification through three days. The new NHC forecast peaks Edouard's intensity at 95 kt (slightly higher than that in the previous advisory), based upon a blend of the SHIPS statistical model and HWRF dynamical model. While the vertical shear picks up significantly between days 3 and 4 as Edouard recurves into the mid-latitude westerlies, the storm motion and shear vectors are likely to align which would allow Edouard to maintain its intensity through day 4. By day 5, cold waters and very strong vertical shear are anticipated to cause substantial weakening. Both the FSU Cyclone Phase Space analysis and the SHIPS storm type indicate Edouard will transition to an extratropical cyclone by day 5. The improved organization of the deep convection as seen in the infrared imagery as well as a couple of microwave passes allow for a fairly confident assessment of the current position. Edouard is moving toward the northwest at about 12 kt, primarily due to the steering induced by a mid-level ridge to its northwest. Edouard will round the western periphery of the ridge and recurve toward the northeast about 3 days. The NHC track prediction is based upon the tightly clustered multi-model TVCA track ensemble and is slightly west of that shown in the previous advisory through 72 hours and slightly east thereafter. The tropical-storm-force wind radii of Edouard was based upon an earlier ASCAT pass, which indicated a substantially larger size than that previously analyzed. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 24.0N 49.7W 60 KT 70 MPH 12H 14/1800Z 25.0N 51.6W 65 KT 75 MPH 24H 15/0600Z 26.2N 54.0W 75 KT 85 MPH 36H 15/1800Z 27.5N 55.8W 85 KT 100 MPH 48H 16/0600Z 28.9N 57.1W 90 KT 105 MPH 72H 17/0600Z 33.0N 56.6W 95 KT 110 MPH 96H 18/0600Z 38.5N 50.0W 85 KT 100 MPH 120H 19/0600Z 42.0N 39.0W 60 KT 70 MPH...POST-TROP/EXTRATROP $$ Forecaster Landsea

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Tropical Depression SIXTEEN-E Forecast Discussion Number 12

2014-09-14 10:49:56| National Hurricane Center (East Pacific)

Issued at 200 AM PDT SUN SEP 14 2014 000 WTPZ41 KNHC 140849 TCDEP1 TROPICAL DEPRESSION SIXTEEN-E DISCUSSION NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL EP162014 200 AM PDT SUN SEP 14 2014 A 0246 UTC GMI overpass shows that the circulation of Sixteen-E may finally be losing definition. However, a burst of deep convection has persisted on the western side of the circulation since that time and Dvorak estimates have actually increased to 30-35 kt. Since the overall shear cloud pattern has not changed substantially since the previous advisory, the intensity has been held at 30 kt for now. Although regular convective bursts have helped to maintain a circulation, this is not expected to continue for long. The dynamical guidance continues to show that the depression will quickly open up into a surface trough as a result of strong vertical wind shear associated with the low-level inflow and upper-level outflow of Hurricane Odile. It is worth noting that 24 hours ago, many of those same models had forecast that Sixteen would have already opened into a remnant trough by now. Given the hostile environment, the NHC forecast still shows weakening into a remnant low within 24 hours and complete dissipation by 36 hours. The depression is accelerating around the circulation of Hurricane Odile and the initial motion is a somewhat uncertain 080/10. There is decent agreement among the models that the depression, or its remnants, will continue to rotate around Hurricane Odile during the next day or so. The official forecast is very close to the consensus of the ECMWF and GFS models for the 24 hours before dissipation. FORECAST POSITIONS AND MAX WINDS INIT 14/0900Z 14.9N 115.3W 30 KT 35 MPH 12H 14/1800Z 15.5N 113.7W 30 KT 35 MPH 24H 15/0600Z 17.1N 111.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 15/1800Z...DISSIPATED $$ Forecaster Zelinsky/Brown

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Hurricane ODILE Forecast Discussion Number 16

2014-09-14 04:59:25| National Hurricane Center (East Pacific)

Issued at 800 PM PDT SAT SEP 13 2014 000 WTPZ45 KNHC 140259 TCDEP5 HURRICANE ODILE DISCUSSION NUMBER 16 NWS NATIONAL HURRICANE CENTER MIAMI FL EP152014 800 PM PDT SAT SEP 13 2014 Satellite imagery indicates that Odile is undergoing rapid intensification. Satellite intensity estimates at 00Z were 90 kt, which is an increase of 35 kt during the last 24 hours. Since then, an eye has become apparent in infrared imagery with cloud tops colder than -80C in the western eyewall. The initial intensity is increased to 95 kt...and this could be conservative. The hurricane has turned to the right and accelerated during the past several hours. The initial motion is 335/10, and the motion over the past 4-5 hours is just west of due north. Odile should turn back toward the northwest during the next several hours as it is steered between a strengthening ridge over the southern United States and a mid-level low or trough west of the Baja California peninsula. The combination of the initial position and motion has lead to a significant northeastward shift in the track model guidance, which now calls for the center of Odile to pass near or over the southern portion of the Baja California peninsula from 36-96 hours. Based on this, the new forecast track is shifted 30-50 n mi to the northeast for the entire forecast period, and it lies just west of Baja California. The new forecast track is in the center of the guidance envelope and is in good agreement with the TVCE consensus model and the Florida State Superensemble. Further northeastward adjustments of the track may be necessary if Odile's northwestward turn occurs later than currently forecast. Rapid intensification is expected to continue until either the hurricane undergoes an eyewall replacement cycle or moves over the wake of cold water left by Hurricane Norbert. The latter is likely to occur in about 18 hours. The forecast peak intensity has been increased to 110 kt at the upper edge of the guidance envelope, and it is possible Odile could get stronger than that. After 18 hours or so, the center should move over cooler water, with land interaction expected after about 36 hours. This should lead to a steady weakening through the remainder of the forecast period. The new forecast track requires major changes for the warnings and watches for Mexico, and a hurricane warning is now in effect for the southern end of the Baja California peninsula. If Odile strikes Baja California as a major hurricane, it will be only the fourth time since since 1967 that such a hurricane has hit the peninsula. 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 for 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 14/0300Z 17.9N 106.5W 95 KT 110 MPH 12H 14/1200Z 19.2N 107.5W 105 KT 120 MPH 24H 15/0000Z 21.4N 109.3W 110 KT 125 MPH 36H 15/1200Z 23.2N 111.0W 100 KT 115 MPH 48H 16/0000Z 24.6N 112.4W 85 KT 100 MPH 72H 17/0000Z 26.5N 114.5W 65 KT 75 MPH 96H 18/0000Z 28.0N 116.0W 45 KT 50 MPH 120H 19/0000Z 29.0N 116.5W 30 KT 35 MPH $$ Forecaster Beven

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