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Hurricane CELIA Forecast Discussion Number 17

2016-07-10 22:49:45| National Hurricane Center (East Pacific)

Issued at 200 PM PDT SUN JUL 10 2016 000 WTPZ44 KNHC 102046 TCDEP4 HURRICANE CELIA DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 200 PM PDT SUN JUL 10 2016 After an early morning burst of deep, cold-topped thunderstorms over the center, dry air entrainment has once again taken its toll on the inner-core convective structure of Celia. The CDO has eroded due to a narrow band of dry air wrapping all the way into the center, which is noted in both conventional and microwave satellite imagery. Celia has now taken the appearance of a tropical cyclone with a banding eye feature. Dvorak estimates are T4.5/77 kt from TAFB and T4.0/65 kt from SAB, and the consensus of various objective satellite intensity estimates is 70 kt. Based on these data, the initial intensity is set to 70 kt, making Celia the second hurricane of the 2016 eastern North Pacific season. The 34- and 50-kt wind radii are based on 1808Z ASCAT-B wind data. The initial motion estimate remains 275/12 kt. There is no significant change to the previous forecast track or reasoning. Celia should move westward for the next 24 h along the southern periphery of a strong deep-layer ridge, followed by turn to the west-northwest on day 2 as a shortwave trough briefly weakens the ridge. By day 3 and beyond, the ridge is forecast to re-strengthen and force Celia back on a westward track. The latest NHC model guidance is tightly clustered about the previous forecast track, so the new forecast is basically just an update of the previous advisory and lies close to the TCVE consensus track model. Celia still has another 24 h or so to strengthen while the vertical wind shear remains light and sea-surface temperatures are above 26.5C. By 48 h, decreasing SSTs ahead of the hurricane should induce gradual weakening, but not as fast as normal due to the light shear conditions that are expected to continue through day 5. The NHC intensity forecast remains above the intensity consensus model IVCN, and continues to follows a blend of the SHIPS and LGEM models. FORECAST POSITIONS AND MAX WINDS INIT 10/2100Z 15.0N 122.5W 70 KT 80 MPH 12H 11/0600Z 15.1N 124.3W 80 KT 90 MPH 24H 11/1800Z 15.3N 126.5W 90 KT 105 MPH 36H 12/0600Z 15.8N 128.5W 90 KT 105 MPH 48H 12/1800Z 16.6N 130.2W 85 KT 100 MPH 72H 13/1800Z 18.5N 133.8W 75 KT 85 MPH 96H 14/1800Z 20.2N 137.7W 60 KT 70 MPH 120H 15/1800Z 21.1N 142.0W 55 KT 65 MPH $$ Forecaster Stewart

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Tropical Storm CELIA Forecast Discussion Number 16

2016-07-10 16:35:41| National Hurricane Center (East Pacific)

Issued at 800 AM PDT SUN JUL 10 2016 000 WTPZ44 KNHC 101435 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 16 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 800 AM PDT SUN JUL 10 2016 The satellite presentation of Celia has improved significantly since the previous advisory, and a large, well-developed CDO feature is now evident with overshooting cold tops of -80C to -85C having developed near the center. The upper-level outflow pattern has also improved and become more symmetrical. Satellite intensity estimates range from T4.0/65 kt from TAFB and SAB to 61 kt from UW-CIMSS ADT and a 1020Z AMSU intensity of 64 kt, putting Celia right at the cusp of hurricane strength. The initial intensity is being held just below hurricane status at 60 kt based on the e-w elongation of the inner-core convection noted in the AMSU data. The initial motion estimate is 275/12 kt. There is no significant change to the previous forecast track or reasoning. Celia is forecast to move westward for the next 24 h or so to the south of a strong deep-layer subtropical ridge. By 36-48 h, Celia is expected to turn west-northwestward as a shortwave trough currently located along 130W longitude moves eastward and weakens the ridge. By day 3, the trough is forecast to weaken and lift out to the north, allowing the ridge to re-strengthen and turn Celia back to a more westward motion. The new official forecast track is essentially just an update of the previous advisory and lies close to the TCVE multi-model consensus. Based on the overall improvement in the infrared satellite pattern, it appears that Celia is finally making the long-anticipated move toward more significant intensification. The best conditions for strengthening are expected to be during the next 24 h or so when SSTs are at or above 27C and the vertical shear remains low at 5 kt or less. By 36-48 h, cooling SSTs ahead of Celia are expected to inhibit the strengthening process, resulting in a leveling off of the intensity forecast. By 72 h and beyond, ocean temperatures will be cooling down to 24C-25C, but the vertical shear is forecast to remain low. As a result, slower than normal weakening is forecast on days 3-5. The official intensity forecast is slightly higher than the intensity consensus model IVCN, and closely follows a blend of the SHIPS and LGEM statistical-dynamical models intensity forecasts. FORECAST POSITIONS AND MAX WINDS INIT 10/1500Z 14.8N 121.3W 60 KT 70 MPH 12H 11/0000Z 14.9N 123.1W 70 KT 80 MPH 24H 11/1200Z 15.0N 125.5W 80 KT 90 MPH 36H 12/0000Z 15.3N 127.6W 85 KT 100 MPH 48H 12/1200Z 15.9N 129.4W 85 KT 100 MPH 72H 13/1200Z 17.9N 132.9W 75 KT 85 MPH 96H 14/1200Z 20.0N 136.6W 60 KT 70 MPH 120H 15/1200Z 21.0N 140.5W 55 KT 65 MPH $$ Forecaster Stewart

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Tropical Storm CELIA Forecast Discussion Number 15

2016-07-10 10:45:55| National Hurricane Center (East Pacific)

Issued at 200 AM PDT SUN JUL 10 2016 000 WTPZ44 KNHC 100845 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 200 AM PDT SUN JUL 10 2016 The intensity analysis of Celia is complicated tonight. The satellite presentation shows a small CDO feature near the center and convective banding to the east and south of the center, which supports Dvorak estimates of T3.5/55 kt from TAFB and SAB. However, a pair of ASCAT-A and ASCAT-B passes between 0445Z and 0535Z showed winds of only 35-40 kt. In addition, recent microwave imagery shows that the inner core is not very organized yet, especially in the low levels. Given the ASCAT data, the initial intensity has been conservatively lowered to 50 kt for this advisory. The ASCAT data were also used to adjust the initial 34-kt wind radii. Celia is still expected to strengthen during the next couple of days and become a hurricane, as the cyclone moves over SSTs of 27-28C. Beyond 48 hours, the SSTs cool along the forecast track, which has been adjusted a bit to the north of the previous advisory. This track takes Celia over SSTs below 26C by day 3 and over SSTs around 24C at days 4 and 5, which should result in weakening. The new NHC intensity forecast is lower than the previous one, but is above all the guidance through 48 hours out of respect to continuity. Late in the period the official forecast was also adjusted lower, but is still above the intensity consensus. Microwave imagery and the above-mentioned ASCAT data indicate that Celia is located a bit north of previous estimates with an initial motion of 280/10. Celia is expected to move westward for the next 24 hours to the south of a mid-level ridge. By 48 hours the cyclone should turn west-northwestward as a weakness develops in the ridge around 130W. The ridge begins to rebuild back to the north of the cyclone at 120 h, which should cause Celia to turn back toward the west. The new NHC track forecast is north of the previous one through the forecast period, mainly due to the more northerly initial position of the system. This track is close to a blend of the GFS and ECMWF models and is near the middle of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 14.8N 119.8W 50 KT 60 MPH 12H 10/1800Z 14.9N 121.5W 60 KT 70 MPH 24H 11/0600Z 15.0N 124.0W 70 KT 80 MPH 36H 11/1800Z 15.1N 126.3W 75 KT 85 MPH 48H 12/0600Z 15.6N 128.2W 80 KT 90 MPH 72H 13/0600Z 17.5N 131.7W 75 KT 85 MPH 96H 14/0600Z 19.7N 135.3W 60 KT 70 MPH 120H 15/0600Z 21.0N 139.5W 50 KT 60 MPH $$ Forecaster Brennan

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Tropical Depression BLAS Forecast Discussion Number 30

2016-07-10 10:35:26| National Hurricane Center (East Pacific)

Issued at 200 AM PDT SUN JUL 10 2016 000 WTPZ43 KNHC 100835 TCDEP3 TROPICAL DEPRESSION BLAS DISCUSSION NUMBER 30 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032016 200 AM PDT SUN JUL 10 2016 Blas has been void of organized deep convection since about 00Z, and convection is unlikely to return given that the cyclone is moving over SSTs less than 24C. The initial intensity is lowered to 30 kt based on the latest Dvorak estimate from TAFB. Blas should weaken to a remnant low later today and the cyclone is expected to open up into a trough after 48 hours. Microwave fixes indicate that Blas is located a bit south of previous estimates and the latest geostationary fixes, and the initial motion estimate is 280/10. The shallow cyclone is expected to gradually turn west-southwestward under the influence of the low-level trade wind flow before dissipation. The new NHC track forecast is a little south of the previous one given the initial position and a southward trend in the multi-model consensus. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 21.2N 135.2W 30 KT 35 MPH 12H 10/1800Z 21.3N 136.8W 30 KT 35 MPH...POST-TROP/REMNT LOW 24H 11/0600Z 21.0N 138.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 11/1800Z 20.5N 141.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 12/0600Z 20.0N 143.4W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 13/0600Z...DISSIPATED $$ Forecaster Brennan

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Tropical Storm CELIA Forecast Discussion Number 14

2016-07-10 04:34:03| National Hurricane Center (East Pacific)

Issued at 800 PM PDT SAT JUL 09 2016 000 WTPZ44 KNHC 100233 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 14 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042016 800 PM PDT SAT JUL 09 2016 Celia has changed very little since the last advisory. A small central dense overcast persists over the low-level center, with an elongated convective band wrapping around the southern and western side of the circulation. The initial intensity remains 55 kt based on Dvorak estimates of T3.5 from TAFB and SAB. Celia appears to have escaped the coldest water of Hurricane Blas's wake and is now over sea surface temperatures warmer than 27 degrees Celsius. In addition, vertical shear is very low and is expected to remain low for the next 5 days. Therefore, more significant strengthening (compared to the past few days) should begin soon and continue during the next 2 to 3 days while the cyclone is over warm water. A gradual weakening trend should occur on day 3 and beyond. The NHC intensity forecast is close to a blend of the SHIPS and LGEM models and is very similar to the previous forecast. Celia's initial motion is westward, or 275/10 kt. A continued westward motion is expected for the next 48 hours while the cyclone is located south of the subtropical ridge. By day 3, Celia will be situated along the southwestern periphery of the ridge and should turn west-northwestward and northwestward at the end of the forecast period. The track guidance continues to be relatively stable and tightly clustered from cycle to cycle, and the new NHC track forecast is just an update of the previous one. FORECAST POSITIONS AND MAX WINDS INIT 10/0300Z 14.5N 118.9W 55 KT 65 MPH 12H 10/1200Z 14.5N 120.6W 65 KT 75 MPH 24H 11/0000Z 14.6N 123.0W 75 KT 85 MPH 36H 11/1200Z 14.6N 125.3W 85 KT 100 MPH 48H 12/0000Z 15.0N 127.3W 90 KT 105 MPH 72H 13/0000Z 16.7N 130.7W 85 KT 100 MPH 96H 14/0000Z 19.0N 134.5W 75 KT 85 MPH 120H 15/0000Z 21.0N 138.5W 60 KT 70 MPH $$ Forecaster Berg

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