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Tropical Storm EDOUARD Forecast Discussion Number 9

2014-09-13 16:38:20| National Hurricane Center (Atlantic)

Issued at 1100 AM AST SAT SEP 13 2014 000 WTNT41 KNHC 131438 TCDAT1 TROPICAL STORM EDOUARD DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 1100 AM AST SAT SEP 13 2014 Although Edouard has lost most of the deep convection, it has a vigorous low-level circulation. Dvorak t-numbers still support an initial intensity of 45 kt. There are some arc clouds currently moving away from the main circulation suggesting that no important changes in intensity are expected during the next few hours. However, the shear is decreasing and this is already reflected in the current better defined upper-level outflow. The low shear, in combination with the pool of anomalous warm waters ahead of Edouard, should result in strengthening, and the cyclone should become a hurricane on Sunday or early Monday. The NHC forecast follows the guidance and is very close to the intensity consensus ICON. The best estimate of the initial motion is toward the northwest or 305 degrees at 11 kt. The steering environment has not changed, with the cyclone's motion being controlled by the subtropical ridge. This pattern will keep Edouard on the same general track for the next 2 to 3 days. After that time, the subtropical ridge will weaken and move east allowing Edouard to turn north, and then recurve into the mid-latitude westerlies. The NHC forecast is close to the multi-model consensus TVCA, which has been very consistent in turning the cyclone northward over the Central Atlantic for the past several model cycles. FORECAST POSITIONS AND MAX WINDS INIT 13/1500Z 21.7N 46.9W 45 KT 50 MPH 12H 14/0000Z 22.7N 48.3W 50 KT 60 MPH 24H 14/1200Z 24.2N 50.5W 55 KT 65 MPH 36H 15/0000Z 25.7N 52.6W 65 KT 75 MPH 48H 15/1200Z 27.1N 55.0W 75 KT 85 MPH 72H 16/1200Z 30.5N 57.5W 80 KT 90 MPH 96H 17/1200Z 35.0N 55.0W 80 KT 90 MPH 120H 18/1200Z 40.0N 47.5W 75 KT 85 MPH $$ Forecaster Avila

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Hurricane ODILE Forecast Discussion Number 13

2014-09-13 10:48:22| National Hurricane Center (East Pacific)

Issued at 200 AM PDT SAT SEP 13 2014 000 WTPZ45 KNHC 130848 TCDEP5 HURRICANE ODILE DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL EP152014 200 AM PDT SAT SEP 13 2014 The satellite presentation of Odile has changed quickly during the past few hours, and the convective pattern now consists of a CDO pattern with the center underneath the convective canopy. Satellite classifications from TAFB and SAB were both T4.0/65 kt at 06Z, and on this basis Odile is upgraded to a hurricane for this advisory. Given that the shear has decreased and the cyclone is situated over SSTs of around 29C, conditions are favorable for at least steady intensification. In fact, the SHIPS model indicates a 57 percent chance of a 25-kt increase in the next 24 hours. However, most of the intensity guidance is less aggressive. Also, a TRMM pass around 04Z suggested that the low-level center was displaced a little to the west of the mid-level center, suggesting that the inner core of Odile may not be aligned. The NHC intensity forecast has been adjusted upward in the short term to account for the observed intensification, but still shows a peak at 90 kt in 48 hours. After that time, the cyclone will be moving over cooler waters and weakening is forecast. The NHC forecast is near the high end of the intensity guidance and is close to the SHIPS model and the FSU Superensemble. The initial motion estimate is 315/04. Odile should accelerate northwestward today as a mid-level ridge amplifies to the northeast of the cyclone. However, significant spread develops in the model guidance after 24 hours, with the latest ECMWF, UKMET, and GFDL solutions show a track farther to the right, closer to or over portions of Baja California. The GFS, GEFS ensemble mean and HWRF are on the left side of the guidance envelope with a track well west of Baja California. These differences appear to be due to variability in the western extent of the subtropical ridge north of Odile and how fast a mid-latitude trough approaches the U.S. West Coast late in the period. The ECMWF model has shifted sharply to the right this cycle, with a more progressive trough turning Odile toward the north-northwest late in the period. The new NHC track forecast is an update of the previous one through 48 hours, and is a little to the right of the previous track after that time, close to the TVCE consensus and the FSU Superensemble. Given the spread in the guidance, confidence in the details of the track forecast, including the potential threat to Baja California, is below normal. A tropical storm watch has been issued for the southern part of the Baja California peninsula. Additional watches and/or warnings could be needed for portions of Baja California later today. FORECAST POSITIONS AND MAX WINDS INIT 13/0900Z 16.4N 105.6W 65 KT 75 MPH 12H 13/1800Z 16.8N 106.2W 70 KT 80 MPH 24H 14/0600Z 18.0N 107.5W 80 KT 90 MPH 36H 14/1800Z 19.6N 109.0W 85 KT 100 MPH 48H 15/0600Z 21.3N 110.7W 90 KT 105 MPH 72H 16/0600Z 23.8N 113.7W 80 KT 90 MPH 96H 17/0600Z 26.0N 116.0W 65 KT 75 MPH 120H 18/0600Z 27.0N 117.0W 45 KT 50 MPH $$ Forecaster Brennan

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Tropical Storm EDOUARD Forecast Discussion Number 8

2014-09-13 10:47:20| National Hurricane Center (Atlantic)

Issued at 500 AM AST SAT SEP 13 2014 000 WTNT41 KNHC 130847 TCDAT1 TROPICAL STORM EDOUARD DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 500 AM AST SAT SEP 13 2014 Edouard is gradually intensifying as a prominent curved band winds most of the way around the tropical storm. However, the convective cloud tops are warming and the central dense overcast is a bit skeletal. Dvorak classifications from TAFB and SAB as well as the CIMSS Advanced Dvorak Technique have increased and all indicate maximum winds of around 45 kt, which is the initial intensity. Edouard is still being affected by 15-20 kt of vertical shear, primarily being induced the southwesterly flow around a very large tropical upper-tropospheric trough to its west. As Edouard moves poleward of the trough axis within the next day or so, the shear will diminish. As the waters the system will traverse are a quite warm 29C, only the somewhat dry atmosphere will not be conducive for a more rapid intensification. Edouard is expected to become a hurricane in a couple of days. After recurvature in three to four days, the storm motion and shear vectors are likely to align which should allow Edouard to maintain its intensity through day 5. The NHC wind speed forecast is nearly the same as that in the previous advisory and is based upon a blend of the LGEM statistical model and the GFDL and HWRF dynamical models. A GCOM/AMSR2 microwave pass helped to locate the center of Edouard and also indicated that the system was tilted northward with height because of the vertical shear. Edouard is moving toward the west- northwest around 13 kt, under the influence of a mid-level ridge over the central Atlantic. In about 3 to 4 days, the cyclone will respond to a break in the ridge by recurving and then accelerating toward the northeast. The track guidance is tightly clustered through the whole forecast period. The NHC track forecast is based upon the TVCA multi-model ensemble and is just to the east of the previous track prediction through 48 hours and just west thereafter. FORECAST POSITIONS AND MAX WINDS INIT 13/0900Z 20.7N 46.2W 45 KT 50 MPH 12H 13/1800Z 21.7N 47.6W 50 KT 60 MPH 24H 14/0600Z 23.1N 49.6W 55 KT 65 MPH 36H 14/1800Z 24.7N 51.8W 60 KT 70 MPH 48H 15/0600Z 26.1N 54.0W 65 KT 75 MPH 72H 16/0600Z 29.5N 57.0W 80 KT 90 MPH 96H 17/0600Z 33.5N 56.0W 80 KT 90 MPH 120H 18/0600Z 38.5N 50.0W 75 KT 85 MPH $$ Forecaster Landsea

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Tropical Storm EDOUARD Forecast Discussion Number 7

2014-09-13 04:55:55| National Hurricane Center (Atlantic)

Issued at 1100 PM AST FRI SEP 12 2014 000 WTNT41 KNHC 130255 TCDAT1 TROPICAL STORM EDOUARD DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 1100 PM AST FRI SEP 12 2014 Edouard's cloud pattern has changed little in organization since the last advisory. Moderately strong south-southwesterly shear is still affecting the cyclone, as evidenced by the center location near the southern edge of the main convective mass in microwave imagery. However, convective cloud top temperatures have cooled some, and the upper-level outflow has expanded to the north and west. Dvorak intensity estimates range from T2.5/35 kt from TAFB and SAB, while an earlier AMSU estimate suggested an intensity of around 45 kt. A blend of these data yields an initial intensity of 40 kt. The center of Edouard was relocated a bit to the south and west based on a 2113 UTC Windsat overpass. That pass, in combination with previous fixes, suggests an initial motion estimate of 295/11. Edouard should move generally west-northwestward for the next few days under the influence of a mid-level ridge over the central Atlantic. In about 3 days, the cyclone should reach a significant break in the the same ridge and gradually turn northward between 55-58w with some decrease in forward speed. The cyclone should accelerate northeastward once it becomes embedded in deep-layer westerly flow over the north Atlantic toward the end of the forecast period. The NHC track forecast is shifted to the left of the previous one through 72 hours due to the the center relocation and a westward trend in the track guidance this cycle. The track forecast lies on the right side of the guidance envelope through 3 days and is near the center of it after that, close to the multi-model consensus. Edouard has been moving through a sheared environment over the tropical Atlantic, characterized by strong low- to mid-level easterly trades and southerly flow aloft. Global models generally forecast a reduction of this shear after another day or so, when upper-level anticyclonic flow develops over the storm. In a couple of days, upper-level troughs to the east and west of Edouard could allow the formation of dual outflow channels while the cyclone is over sea surface temperatures around 30 deg C. This should allow intensification to hurricane strength. After recurvature, the storm motion and shear vectors are likely to align which should allow Edouard to maintain its intensity until it encounters increasing shear and cooler waters by day 5. The NHC wind speed forecast is nearly unchanged relative to the previous, except to show a slightly higher peak intensity in agreement with the latest guidance. FORECAST POSITIONS AND MAX WINDS INIT 13/0300Z 19.5N 45.2W 40 KT 45 MPH 12H 13/1200Z 20.4N 46.7W 45 KT 50 MPH 24H 14/0000Z 21.8N 48.7W 50 KT 60 MPH 36H 14/1200Z 23.1N 50.8W 60 KT 70 MPH 48H 15/0000Z 24.6N 53.1W 65 KT 75 MPH 72H 16/0000Z 27.9N 56.4W 80 KT 90 MPH 96H 17/0000Z 32.2N 56.6W 80 KT 90 MPH 120H 18/0000Z 37.0N 52.0W 75 KT 85 MPH $$ Forecaster Kimberlain

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Tropical Depression SIXTEEN-E Forecast Discussion Number 7

2014-09-13 04:55:55| National Hurricane Center (East Pacific)

Issued at 800 PM PDT FRI SEP 12 2014 000 WTPZ41 KNHC 130255 TCDEP1 TROPICAL DEPRESSION SIXTEEN-E DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP162014 800 PM PDT FRI SEP 12 2014 Tropical Depression Sixteen-E has become poorly organized this evening. Deep convection is limited to an amorphous blob on the western side of the increasingly elongated low-level wind center. The initial intensity for this advisory has been held at 30 kt based on the Dvorak classification from TAFB. The recent disruption of the circulation is primarily due to the proximity of the depression to Tropical Storm Odile, located about 800 n mi to the east. As a result, the environment around the depression consists of increasing wind shear in the vertical and horizontal. The environment is expected to become even more unfavorable while the depression moves closer to Odile. All of the global and regional dynamical models forecast that the depression will open up into a trough within 36 hours, and some suggest that this could occur much sooner than that. The cyclone is beginning to accelerate toward the east and the initial motion is 110/05. The models remain in good agreement that the depression, or its remnants, will accelerate toward Odile on a nearly straight line until dissipation. No substantial changes were made to the track forecast. FORECAST POSITIONS AND MAX WINDS INIT 13/0300Z 16.6N 118.1W 30 KT 35 MPH 12H 13/1200Z 16.4N 117.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 24H 14/0000Z 16.0N 115.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 14/1200Z...DISSIPATED $$ Forecaster Zelinsky/Beven

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