Tropical Storm Lowell Forecast Discussion
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335 WTPZ42 KNHC 280248 TCDEP2 Tropical Storm Lowell Discussion Number 2 NWS National Hurricane Center Miami FL EP122026 500 PM HST Thu Aug 27 2026 Satellite imagery shows a large area of deep convection that has been persisting with Lowell, with a ball of deep convection near and over the center, and a curved band noted as well. A 27/2204Z AMSR-2 pass also shows the same curved banding pattern. Earlier scatterometer data showed that the center was slightly elongated, with tropical-storm-force winds confined to the southern semicircle and a radius of maximum wind (RMW) of about 50 n mi. The latest TAFB Dvorak classification is T2.5/35 kt and objective estimates have been ranging from 30-42 kt. The initial intensity is held at 35 kt for this advisory, but given the impressive banding and maintenance of deep convection, this estimate could be slightly conservative. The initial motion estimate remains slowly east-northeastward, or 70 degrees at 4 kt. A slow counterclockwise turn toward the north and then the west is expected over the next 36 h as ridging builds in to the northeast and north. A generally westward to west-northwestward motion should then continue for the rest of the forecast period. There remains a ton of spread in the forward speed from 72 to 120 h, which could be related to Karina's location and size, relative to Lowell's. The NHC track is a little faster toward the west than the previous forecast beyond 36 hours, but not nearly as fast as the HCCA and GDMI. Lowell will be over relatively favorable environmental conditions for the next 5 days, with warm sea-surface temperatures, light to moderate easterly wind shear and relatively moist air. Despite these favorable conditions, it is a bit perplexing that the models are so slow to strengthen Lowell to a hurricane. Perhaps the slow strengthening at first could be due to the large RMW observed on the previous ASCAT pass along with the moderate easterly shear. If the cyclone is able to gain enough latitude and get north of 13N, it should find itself in a more favorable upper-level environment, which could allow for more significant strengthening in a few days. Little change has been made to the previous NHC intensity forecast in the first 4 days, but a higher intensity is shown at day 5. The NHC intensity forecast is higher than the intensity consensus, but not as high as the HMON and HCCA, which bring Lowell to major hurricane strength by day 5. The confidence in the intensity forecast is below average, and it is possible that Lowell could strengthen more than forecast. FORECAST POSITIONS AND MAX WINDS INIT 28/0300Z 11.4N 133.5W 35 KT 40 MPH 12H 28/1200Z 11.8N 133.0W 40 KT 45 MPH 24H 29/0000Z 12.3N 133.2W 45 KT 50 MPH 36H 29/1200Z 12.5N 134.3W 50 KT 60 MPH 48H 30/0000Z 12.7N 135.8W 55 KT 65 MPH 60H 30/1200Z 12.9N 137.5W 60 KT 70 MPH 72H 31/0000Z 13.2N 139.3W 70 KT 80 MPH 96H 01/0000Z 13.5N 142.8W 80 KT 90 MPH 120H 02/0000Z 13.9N 146.0W 95 KT 110 MPH $$ Forecaster Hagen