je.st
news
Tag: discussion
Tropical Depression TWELVE Forecast Discussion Number 3
2016-09-15 04:56:03| National Hurricane Center (Atlantic)
Issued at 1100 PM AST WED SEP 14 2016 000 WTNT42 KNHC 150255 TCDAT2 TROPICAL DEPRESSION TWELVE DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 1100 PM AST WED SEP 14 2016 The convective pattern of the depression has improved some since the previous advisory with short curved bands having developed in all quadrants. In addition, the upper-level outflow has also improved and become more symmetrical. Satellite intensity estimates range from 30 kt from TAFB and SAB, 37-41 kt in recent AMSU estimates, and an ADT value of T2.8/41 kt. Due to the lack of persistent inner-core convection, the intensity is being maintained at 30 kt. The initial motion is 280/12 kt. A deep-layer ridge to the north of the cyclone is expected steer the system west-northwestward and then westward during the next 48 hours, accompanied by some decrease in forward speed as the ridge weakens slightly. By 72 hours and beyond, the ridge is forecast to build southward slightly, forcing the cyclone on a west-southwestward track over warmer waters. The new forecast track is basically just an update of the previous advisory track, and lies close to the consensus models. Some strengthening is expected during the next 24 hours or so. After that, the cyclone will encounter moderate to strong westerly vertical wind shear caused by a developing upper-level trough to the north of the cyclone. The new intensity forecast continues to show the system weakening back to a depression by 36 hours. On days 4 and 5, some slight re-strengthening is expected when the cyclone moves over SSTs near 28 deg C and into more favorable mid- and upper-level environments as shown by the ECMWF and UKMET models. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 17.6N 27.5W 30 KT 35 MPH 12H 15/1200Z 17.8N 29.4W 35 KT 40 MPH 24H 16/0000Z 18.0N 31.9W 35 KT 40 MPH 36H 16/1200Z 18.1N 34.3W 30 KT 35 MPH 48H 17/0000Z 17.9N 36.6W 30 KT 35 MPH 72H 18/0000Z 17.5N 40.7W 30 KT 35 MPH 96H 19/0000Z 17.4N 44.6W 35 KT 40 MPH 120H 20/0000Z 17.9N 49.0W 40 KT 45 MPH $$ Forecaster Stewart
Tags: number
discussion
twelve
tropical
Tropical Storm ORLENE Forecast Discussion Number 17
2016-09-15 04:52:28| National Hurricane Center (East Pacific)
Issued at 800 PM PDT WED SEP 14 2016 000 WTPZ41 KNHC 150252 TCDEP1 TROPICAL STORM ORLENE DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL EP162016 800 PM PDT WED SEP 14 2016 Orlene's convective signature remains a small, symmetric central dense overcast with some banding in the northern semicircle. However, the cloud top temperatures have warmed some and the extent of the cold cloudiness has diminished slightly during the last several hours. A blend of the TAFB/SAB subjective Dvorak, CIMSS Advanced Dvorak, and CIMSS/CIRA AMSU suggest that Orlene has weakened to a tropical storm with 60 kt as the initial intensity. Orlene is situated directly under the upper-level subtropical ridge and thus is experiencing very low vertical shear. However, the tropical storm is expected to ride along the 26C SST contour while the not-very-moist environment becomes quite dry during the next three days. In addition, by days four and five, the shear should go up substantially as Orlene approaches a mid- to upper-level low. The bottom line is that the tropical storm should gradually weaken. The NHC intensity forecast is based upon a blend of the LGEM/SHIPS statistical models and the COAMPS dynamical model, and is quite similar to that from the previous advisory. Perhaps the biggest uncertainty is when the deep convection will cease. The forecast is for that to occur around day five, but it would not be surprising if this occurred significantly earlier. Orlene is moving toward the west-northwest at about 5 kt. The system is expected to turn toward the west or west-southwest and move faster for the next three to four days as mid-level ridging builds to its north. By day five, Orlene begins responding to the upper-level low that it approaches by turning toward the west-northwest. The NHC track forecast is slightly south of the previous advisory and is based upon the tightly clustered members of the multi-model TVCN consensus technique. A 0119Z AMSU pass allowed a modification of the 34 and 50 kt wind radii to be more asymmetric. The NHC wind radii forecast is based upon the multi-model RVCN consensus technique and is slightly smaller than that from the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 20.4N 120.4W 60 KT 70 MPH 12H 15/1200Z 20.2N 121.5W 55 KT 65 MPH 24H 16/0000Z 20.0N 123.6W 50 KT 60 MPH 36H 16/1200Z 19.7N 125.9W 45 KT 50 MPH 48H 17/0000Z 19.6N 128.3W 40 KT 45 MPH 72H 18/0000Z 19.5N 133.6W 35 KT 40 MPH 96H 19/0000Z 20.0N 138.0W 30 KT 35 MPH 120H 20/0000Z 21.0N 142.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Landsea
Tags: number
discussion
storm
tropical
Tropical Storm JULIA Forecast Discussion Number 5
2016-09-15 04:35:17| National Hurricane Center (Atlantic)
Issued at 1100 PM EDT WED SEP 14 2016 000 WTNT41 KNHC 150234 TCDAT1 TROPICAL STORM JULIA DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112016 1100 PM EDT WED SEP 14 2016 The low-level circulation has become a little bit elongated, and due to southwesterly shear most of the convection has shifted to the northeast of the center. A convective band is still wrapping around the eastern portion of the cyclone. Based on surface observations, WSR-88D Doppler velocity data, and satellite estimates, the initial intensity is kept at 35 kt. Since the cyclone is over water, some slight intensification is possible during the next day or so before the shear increases as forecast by global models. A gradual weakening should then begin in about 36 hours. Julia appears to be moving toward the east-northeast at about 4 kt. The steering currents are forecast to collapse, and most of the models keep a weakening cyclone meandering during the next few days. The NHC track forecast follows such a trend and predicts a very slow eastward drift during the next 48 hours. Little motion is anticipated thereafter. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 32.1N 79.8W 35 KT 40 MPH 12H 15/1200Z 32.2N 79.2W 35 KT 40 MPH 24H 16/0000Z 32.2N 78.8W 40 KT 45 MPH 36H 16/1200Z 32.1N 78.6W 35 KT 40 MPH 48H 17/0000Z 32.0N 78.5W 35 KT 40 MPH 72H 18/0000Z 32.0N 79.0W 30 KT 35 MPH 96H 19/0000Z 32.0N 79.0W 30 KT 35 MPH 120H 20/0000Z 32.0N 79.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Avila
Tags: number
discussion
storm
tropical
Hurricane ORLENE Forecast Discussion Number 16
2016-09-14 22:48:02| National Hurricane Center (East Pacific)
Issued at 200 PM PDT WED SEP 14 2016 000 WTPZ41 KNHC 142047 TCDEP1 HURRICANE ORLENE DISCUSSION NUMBER 16 NWS NATIONAL HURRICANE CENTER MIAMI FL EP162016 200 PM PDT WED SEP 14 2016 The satellite signature of Orlene continues to slowly decay, with a small area of cold convection remaining near a cloud-filled eye. The various satellite intensity estimates have decreased since the last advisory, and the initial intensity is reduced to a possibly generous 65 kt. There is no change in the philosophy of the intensity forecast. Orlene is forecast to be in an area of light vertical wind shear for the next 3-4 days, after which the shear is forecast to increase again. Even with the favorable shear, the tropical cyclone is forecast to be over marginally warm SSTs and move into a drier and more stable air mass. These environmental conditions are expected to result in gradual weakening during the forecast period. The new NHC intensity forecast is again changed little since the previous advisory and it lies on the low side of the intensity guidance in best agreement with the SHIPS model. Orlene is moving a little faster toward the west or 270/5. A faster motion toward the west and west-southwest is forecast during the next 3-4 days as the subtropical ridge strengthens to the north of the cyclone. Late in the forecast period, a large mid- to upper-level low expected to be well northeast of the Hawaiian Islands should produce a break in the subtropical ridge, allowing the cyclone to turn west-northwestward. The forecast guidance had shifted southward since the last advisory, especially after 48 hours. Thus, the new forecast track is also shifted southward from 72-120 hours. However, it still lies north of the center of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 20.2N 119.7W 65 KT 75 MPH 12H 15/0600Z 19.9N 120.8W 60 KT 70 MPH 24H 15/1800Z 19.8N 122.7W 55 KT 65 MPH 36H 16/0600Z 19.7N 124.9W 50 KT 60 MPH 48H 16/1800Z 19.5N 127.3W 45 KT 50 MPH 72H 17/1800Z 19.5N 132.0W 40 KT 45 MPH 96H 18/1800Z 19.5N 137.0W 35 KT 40 MPH 120H 19/1800Z 21.0N 141.0W 30 KT 35 MPH $$ Forecaster Beven
Tags: number
discussion
forecast
hurricane
Tropical Depression TWELVE Forecast Discussion Number 2
2016-09-14 22:40:53| National Hurricane Center (Atlantic)
Issued at 500 PM AST WED SEP 14 2016 000 WTNT42 KNHC 142040 TCDAT2 TROPICAL DEPRESSION TWELVE DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 500 PM AST WED SEP 14 2016 The depression has not become better organized since the last advisory, with the most concentrated convection now in a cluster just west of the estimated center position. The initial intensity remains 30 kt in best agreement with a satellite intensity estimate from SAB. The initial motion is a somewhat uncertain 295/13 kt. A low- to mid-level ridge should steer the system west-northwestward and then westward during the forecast period, with some decrease in forward speed after 36-48 hours as the ridge weakens slightly. The new forecast track is similar to, but a little north of, the previous track based on a slight northward shift in the track guidance. Some strengthening is expected during the next 12 hours or so. After that, the cyclone will encounter strong westerly vertical wind shear caused by a developing upper-level trough near and north of the cyclone. This, combined with passage over sea-surface temperatures of about 26C-27C, should lead to weakening, and the intensity forecast shows the system weakening back to a depression by 36 hours. Near the end of the forecast period, the dynamical models continue to diverge on the evolution of the upper-level winds, with the ECMWF and UKMET forecasting a more favorable ridge pattern near the cyclone, whereas the GFS has an upper-level trough close by. Based on these conflicting models, the forecast leans toward the ECMWF/UKMET scenario and shows some re-intensification by 120 hours. An alternative scenario is that the cyclone degenerates into a broad low pressure area or tropical wave as forecast by the GFS. Overall, the intensity forecast remains on the low side of the guidance in best agreement with the LGEM. Gusty winds remain possible over the Cabo Verde Islands tonight, whereas locally heavy rains will remain possible through Thursday. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 17.4N 26.5W 30 KT 35 MPH 12H 15/0600Z 17.9N 28.4W 35 KT 40 MPH 24H 15/1800Z 18.0N 30.8W 35 KT 40 MPH 36H 16/0600Z 18.1N 33.2W 30 KT 35 MPH 48H 16/1800Z 18.1N 35.6W 30 KT 35 MPH 72H 17/1800Z 18.0N 39.5W 30 KT 35 MPH 96H 18/1800Z 17.5N 43.5W 35 KT 40 MPH 120H 19/1800Z 18.0N 47.5W 40 KT 45 MPH $$ Forecaster Beven
Tags: number
discussion
twelve
tropical
Sites : [816] [817] [818] [819] [820] [821] [822] [823] [824] [825] [826] [827] [828] [829] [830] [831] [832] [833] [834] [835] next »