WTPN21 PHNC 300800 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 94E)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 160 NM EITHER SIDE OF A LINE FROM 12.0N 98.5W TO 14.6N 104.9W WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 23 TO 27 KNOTS. METSAT IMAGERY AT 300000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.2N 99.0W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 12 KNOTS. 2. REMARKS: AN AREA OF CONVECTION (INVEST 94E) IS LOCATED NEAR 12.2N 99.0W, APPROXIMATELY 1585 NM SOUTHEAST OF SAN DIEGO, CA. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP FLARING CONVECTION ON THE EASTERN AND SOUTHERN PERIPHERY. ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE CONDITIONS FOR FURTHER DEVELOPMENT OF INVEST 94E WITH GOOD EQUATORWARD UPPER-LEVEL OUTFLOW, LOW (10-15KTS) VWS, AND WARM (29-30C) SEA SURFACE TEMPERATURES. MODEL GUIDANCE SHOWS GOOD AGREEMENT ON 94E CONTINUING ON A WEST-NORTHWESTWARD TRACK WITH FURTHER INTENSIFICATION OVER THE 36-48HRS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 27 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH. 3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 310800Z.// NNNN
Tropical Storm Carlotta Discussion Number 3 NWS National Hurricane Center Miami FL EP032024 800 PM MST Wed Jul 31 2024
Carlotta continues to show signs of organization this evening. Geostationary satellite imagery has shown regular bursts of deep convection with cloud top temperatures below -80 degrees C near the center of the storm. Microwave satellite imagery from AMSR2 also revealed decent structure of the low-level center. Dvorak satellite estimates from TAFB and SAB agree Carlotta's intensity is 45 kt, and the initial intensity has been increased to match these estimates.
The storm is moving west-northwestward at about 10 kt. Carlotta is expected to gradually turn more westward in about a day or so as a ridge builds over the southwestern United States. By Sunday, the storm is expected to turn back to the west-northwest and slow as it reaches a weakness in the ridge. The latest official track forecast has once again shifted slightly north from the previous forecast and has a slightly quicker along-track speed.
Signs are pointing towards Carlotta rapidly intensifying over the next day or so. The storm is moving over warm waters, and the environmental shear is expected to remain weak. Statistical model guidance indices show between a 30 to 40 percent chance of rapid intensification (RI) in the next 24 h. This model guidance, paired with the latest structural information provided by satellite imagery, are the basis for now explicitly forecasting RI in the next 24 h. This period of RI could be interrupted in a day or so by an increase in vertical wind shear, though the global models differ in evolution of upper-level winds, making the intensity forecast somewhat uncertain. The latest intensity forecast lies close to the corrected consensus aid, HCCA, and the peak has been increased to 90 kt at 60 hours.
Hurricane Carlotta Discussion Number 12 NWS National Hurricane Center Miami FL EP032024 200 AM PDT Sat Aug 03 2024
Carlotta has become a little better organized over the past several hours. An eye has occasionally been apparent in satellite images and deep convection remains most organized on the south side of the circulation. There are some intrusions of dry air, however, that have caused gaps in the deep convective pattern north of the center. A blend of the latest objective and subjective satellite intensity estimates support nudging up the initial intensity to 80 kt. Carlotta is a compact hurricane with recent ASCAT-B data showing that the tropical-storm-force winds extend outward up to 80 n mi from the center and hurricane-force winds are estimated to only extend about 10 n mi from the center.
The hurricane could strengthen a little more while it remains in conducive environmental conditions, but the window for intensification should close by this evening. Steady weakening is expected to begin tonight once Carlotta crosses the 26 C SST isotherm and moves into an environment of increasing vertical wind shear and drier air. Carlotta will likely fall below hurricane strength on Sunday and weaken to a remnant low in 3 to 4 days. The NHC intensity forecast follows the trend in the guidance.
Carlotta is moving westward at 12 kt. A west-northwestward motion at a slightly slower pace is expected during the next few days as the hurricane moves toward the western periphery of a mid-level ridge. However, once Carlotta becomes a weak and shallow system by the middle of next week, it will likely turn back westward in the low-level flow. Little change was made to the previous track forecast, and this one is close to the middle of the guidance envelope.
