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Hurricane Douglas Forecast Discussion Number 12
2020-07-23 10:42:54| National Hurricane Center (East Pacific)
Issued at 1100 PM HST Wed Jul 22 2020 000 WTPZ43 KNHC 230842 TCDEP3 Hurricane Douglas Discussion Number 12 NWS National Hurricane Center Miami FL EP082020 1100 PM HST Wed Jul 22 2020 Douglas has rapidly intensified since earlier today, with satellite images showing a ragged, but nearly clear eye surrounded by cold cloud tops of -70 C. There appears to be a little dry air intrusion across the northern portion of the circulation, which is limiting the amount of deep convection wrapping around that part of the eye. Both Dvorak intensity estimates from TAFB and SAB have increased to 5.5/100 kt, while the ADT and SATCON estimate averages have increased to 105 kt. Since the cyclone's appearance has improved slightly since these estimates arrived, the advisory initial intensity has been set at 105 kt, making Douglas a major hurricane. The environmental conditions supporting the rapid intensification appear at their best at this time as the cyclone is over SSTs of over 28 C, with low wind shear in a moist air mass. If the cyclone can fight off the dry air in the northern semicircle, some additional strengthening is possible, especially early Thursday. However, Douglas should be gradually moving into a less hospitable environment for strengthening over the next few days, and in 36 h the cyclone is forecast to cross the 26 C SST isotherm and into a region where the 500-700 mb relative humidity is less than 60 percent. Later on in the forecast period, wind shear is also expected to be on the increase. These factors should cause the cyclone to gradually weaken beginning Thursday night. Douglas is expected to be at or near hurricane intensity as it approaches the Hawaiian Islands on Sunday, and all interests there should monitor forecasts as they evolve over the next few days. The NHC forecast was adjusted higher in the first 12 h based on the initial intensity, and is very close to the previous forecast after that time. This intensity forecast closely follows the various consensus aids. The initial motion is west-northwest or 295/15. Douglas should continue on a general west-northwestward motion for the next few days, steered by a large mid-level ridge extending across much of the central and eastern North Pacific. The cyclone is then forecast to turn more toward the west late in the forecast period as it moves near the Hawaiian Islands. The track guidance is tightly clustered and the new NHC is little changed from the previous one. Key Messages: 1. Douglas is expected to move near or over portions of the Hawaiian Islands this weekend, and there is an increasing chance that strong winds and heavy rainfall could affect portions of the state beginning on Sunday. Interests on the Hawaiian Islands should continue to monitor the progress of Douglas and the official forecasts as they evolve over the next few days. FORECAST POSITIONS AND MAX WINDS INIT 23/0900Z 13.1N 134.0W 105 KT 120 MPH 12H 23/1800Z 14.0N 136.3W 110 KT 125 MPH 24H 24/0600Z 15.3N 139.5W 110 KT 125 MPH 36H 24/1800Z 16.5N 142.5W 105 KT 120 MPH 48H 25/0600Z 17.6N 145.5W 90 KT 105 MPH 60H 25/1800Z 18.6N 148.5W 80 KT 90 MPH 72H 26/0600Z 19.4N 151.4W 70 KT 80 MPH 96H 27/0600Z 20.5N 157.1W 55 KT 65 MPH 120H 28/0600Z 21.0N 163.7W 45 KT 50 MPH $$ Forecaster Latto
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