{"id": "1207945701724454914", "title": "Tropical Cyclone Discussion", "adv_date": "2026-09-06T15:00:00Z", "msg": "709\nWTPA44 PHFO 061449\nTCDCP4\n \nHurricane Lowell Discussion Number  42\nNWS Central Pacific Hurricane Center Honolulu HI   EP122026\nIssued by NWS National Hurricane Center Miami FL\n500 AM HST Sun Sep 06 2026\n \nAn Air Force Reserve Hurricane Hunter aircraft completed a mission \nin Lowell a few hours ago and measured peak 700-mb flight-level \nwinds of 114 kt, which typically equates to an intensity of 100-105 \nkt. However, dropsonde data from the plane also indicated that the \ncentral pressure (943 mb) was a bit lower than previously \nestimated. For that reason, Lowell's currently intensity is held at \n110 kt, which is also very close to the latest UW-CIMSS DPRINT and \nSATCON estimates.\n\nLowell is in the midst of its anticipated sharp turn, and the \ncurrent motion is north-northwestward (335/5 kt). The steering \ncontinues to be dominated by a cutoff mid-/upper-level low located \nabout 350 n mi north-northeast of Hawaii, which is forecast to \nmove west-southwestward and cause Lowell to accelerate toward the \nnorth and north-northeast through Monday night. The track guidance \nis tightly packed through that period, although some of the \nbetter-performing models (HCCA and GDMI) lie along the eastern \nedge of the envelope. That required an additional eastward nudge in \nthe official forecast, bringing Lowell's center near or over the \nisland of Nihoa in 48 hours and about 100 n mi west of Kauai \nCounty. After the center passes the Hawaiian Islands, model guidance \nis in good agreement that Lowell will turn westward by early Friday, \nbut there is some disagreement on the sharpness of that turn.\n \nVertical shear is expected to remain low for another 12 hours, so \nfluctuations in intensity will still be possible through this \nafternoon. South-southwesterly shear is forecast to increase to \nstrong levels by tonight, which should induce a gradual weakening \ntrend while Lowell is passing the Hawaiian Islands. However, even \nwith the weakening, Lowell is not expected to change much in size, \nand tropical storm conditions are forecast to spread across Kauai \nand Niihau by Monday afternoon, necessitating the issuance of a \ntropical storm warning. Lowell is forecast to weaken to a tropical \nstorm by early Wednesday after passing the Hawaiian Islands, and \ncontinued weakening is expected through the end of the week due to \ncontinued shear, marginal sea surface temperatures, and dry \nmid-level air.\n \n \nKEY MESSAGES:\n \n1. Lowell is forecast to pass west of Kauai County late Monday into\nearly Tuesday. A Tropical Storm Warning is now in effect for Kauai\nCounty, including Kauai and Niihau, where tropical storm conditions\nare expected to begin Monday afternoon and continue through Tuesday \nmorning. Strong wind gusts will be possible atop mountains and on \nwindward and leeward slopes.\n \n2. Heavy rainfall associated with Lowell will begin to impact the \nHawaiian Islands today and continue through early this week. Periods \nof heavy rain may produce significant flash flooding and mudslides, \nespecially across Kauai County and portions of the Big Island.\n \n3. Large swells from Lowell are expected to produce life-threatening\nsurf and rip current conditions across portions of the Hawaiian\nIslands during the next several days. Surf along exposed portions\nof Kauai County could also produce coastal flooding and inundation\nof low-lying areas Monday through Monday night.\n \n \nFORECAST POSITIONS AND MAX WINDS\n \nINIT  06/1500Z 14.7N 163.8W  110 KT 125 MPH\n 12H  07/0000Z 15.6N 163.9W  110 KT 125 MPH\n 24H  07/1200Z 17.5N 163.3W  105 KT 120 MPH\n 36H  08/0000Z 20.0N 162.5W  100 KT 115 MPH\n 48H  08/1200Z 23.0N 161.9W   90 KT 105 MPH\n 60H  09/0000Z 25.4N 162.0W   75 KT  85 MPH\n 72H  09/1200Z 26.9N 162.8W   65 KT  75 MPH\n 96H  10/1200Z 27.9N 166.6W   50 KT  60 MPH\n120H  11/1200Z 27.7N 170.6W   40 KT  45 MPH\n \n"}