ZCZC MIATCDAT4 ALL TTAA00 KNHC DDHHMM Post-Tropical Cyclone Isaias Discussion Number 15 NWS National Hurricane Center Miami FL AL092026 400 AM CDT Sat Oct 10 2026 Isaias has very rapidly weakened over Alabama and has transitioned into a post-tropical cyclone. Satellite images show that all deep convection has been scoured well northward away from the low-level center, with a warm front extending eastward from the former tropical cyclone. Thus this is the last advisory on Isaias, with an initial intensity of 30 kt set from surface observations. The cyclone should move northward and north-northeastward this weekend and gradually weaken as it moves across the Tennessee and Ohio Valleys. No significant changes were made to the track or intensity forecasts, except lower wind speed on day 1. Note there is still a risk of some high wind gusts over the southern Appalachians as the cyclone moves just to the west of those mountains, along with the potential for heavy rain causing flash floods. This is the last tropical cyclone discussion issued by the National Hurricane Center on this system. Future information on this system can be found in discussions issued by the Weather Prediction Center beginning at 1000 AM CDT, under AWIPS header TCDAT4, WMO header WTNT44 KWNH, and on the web at www.hurricanes.gov. Rainfall forecasts for the United States are at: https://www.wpc.ncep.noaa.gov/qpf/qpf2.shtml and outlooks of flash flood risks can be found at https://www.wpc.ncep.noaa.gov/qpf/excessive_rainfall_outlook_ero.php Key Messages: 1. Heavy rainfall associated with the post-tropical remnants of Isaias will be spreading quickly northward into the Tennessee Valley, Southern Appalachians and Southeast today. Considerable flash and urban flooding will be possible. Landslides are also possible across the Southern Appalachians. Additional heavy rains are possible across portions of Northwest Florida and heavy rains are also possible across coastal Southwest Florida, resulting in flash and urban flooding. 2. Post-storm safety: Follow advice of local officials and avoid areas of downed power lines and flooding. Ensure generators are properly ventilated and placed outside at least 20 feet away from dwellings and garages to avoid carbon monoxide poisoning. During clean up, be careful when using chainsaws and power tools. Drink plenty of water to avoid heat exhaustion. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 32.0N 86.5W 30 KT 35 MPH...POST-TROPICAL 12H 10/1800Z 33.7N 86.7W 25 KT 30 MPH...POST-TROP/INLAND 24H 11/0600Z 35.2N 86.0W 25 KT 30 MPH...POST-TROP/INLAND 36H 11/1800Z 37.6N 82.7W 20 KT 25 MPH...POST-TROP/INLAND 48H 12/0600Z...DISSIPATED $$ Forecaster Blake NNNN

ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM Tropical Storm Rachel Discussion Number 53 NWS National Hurricane Center Miami FL EP182026 200 AM PDT Sat Oct 10 2026 Satellite imagery indicates that Rachel's convective organization has changed little over the past several hours, with the deepest convection remaining confined to the northern and northeastern portions of the circulation due to increasing southwesterly vertical wind shear. A 0505 UTC ASCAT-B scatterometer pass revealed peak winds of around 46 kt and an expanding wind field, which helped refine the initial wind radii. Based on these data, the initial intensity is set at 50 kt. The initial motion is northeastward, or 050/19 kt. A turn toward the north-northeast, accompanied by additional acceleration to around 25 kt, is expected during the next 24 h as Rachel interacts with a deepening mid- to upper-level trough over the western United States. This motion should bring Rachel ashore just south of the U.S./Mexico border tonight, followed by a rapid north-northeastward motion into the southwestern United States. Track guidance has shifted slightly to the right compared to 24 hours ago, but has changed little since the previous cycle. The latest NHC track forecast is essentially unchanged from the previous prediction and lies close to the HCCA and GDMI aids. Some additional strengthening is possible during the next 12 to 24 h as Rachel accelerates northeastward and interacts with the deepening upper-level trough. The NHC intensity forecast shows Rachel strengthening to 55 kt before moving inland tonight. Rachel's wind field has also begun to expand, and additional expansion is possible as the cyclone accelerates northeastward and interacts with the upper-level trough. This could result in tropical-storm-force winds extending farther from the center as Rachel begins to lose its tropical characteristics. Rachel is expected to weaken rapidly after landfall as it encounters the mountainous terrain of northern Baja California and the southwestern United States. The cyclone is forecast to become post-tropical by 36 h and dissipate by 48 h. The latest NHC intensity forecast is similar to the previous prediction and lies near the middle to upper end of the guidance envelope. Key Messages: 1. Rachel is expected to approach and move ashore along the coast of northern Baja California or extreme Southern California at tropical storm strength tonight. Tropical storm conditions are expected in portions of northern Baja California, Mexico, where Tropical Storm Warnings are in effect. Tropical storm conditions are also possible in extreme Southern California, eastern Baja California, and portions of northwestern Mexico where Tropical Storm Watches are in effect. 2. Damaging wind gusts associated with Rachel and its remnants are expected to spread over portions of northwestern Mexico and interior portions of the Southwest United States, especially in areas of higher terrain, tonight and Sunday. 3. Rachel and its moisture will spread over portions of the Southwest United States and northern Baja California peninsula through this weekend. This will lead to increasing coverage of rainfall and for the potential for significant flash and urban flooding. 4. Waves generated by Rachel, combined with an incoming long-period southerly swell, will produce life-threatening surf and rip current conditions along the coasts of Southern California and northern Baja California. Major coastal flooding has already been occurring in some areas, with observed water levels running as much as 1.5 feet above predictions. Coastal flooding and erosion are expected to worsen tonight into Sunday morning as the highest waves associated with Rachel coincide with high tides and already elevated water levels. Hazardous coastal conditions are expected to continue into early next week. Please consult products from your local weather office. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z…

ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Hurricane Simon Discussion Number 12 NWS National Hurricane Center Miami FL EP202026 300 AM CST Sat Oct 10 2026 The very small inner-core of Simon remains very impressive as the cyclone has continued to strengthen. The proxy-visible imagery has started to show that the tiny eye of the hurricane is clearing out. The most recent TAFB Dvorak fix was a T6.0/115 kt, while the objective raw T-number intensity estimates from UW-CIMSS have ranged from 120 to 132 kt. Based on a blend of the objective and subjective intensity estimates, the initial intensity has been increased to 125 kt for this advisory. The wind radii has been adjusted based on a recent ASCAT pass. The hurricane is expected to continue to rapidly strengthen over the next day or so, with a peak intensity of 135 kt forecast. Given the small size of the inner core, there is a higher than normal degree of uncertainty with the peak intensity. Therefore, it is possible that Simon could become stronger than what is forecast. Only a few changes were made for the current NHC forecast compared to the previous forecast. Simon's initial motion is estimated at 360/4 kt, northward. The hurricane is being steered by the southerly mid-level flow produced by high pressure over southern Mexico and a longwave mid-tropospheric trough to the west stretching south-southwestward from the southwest United States. There is still some uncertainty about the track for Simon, as most of the skilled model guidance including HCCA and GDMI forecast aids have been experiencing to the left of the track bias. The current NHC track forecast has the hurricane move inland over the Mexican states of Colima and Jalisco; however, it is possible that the cyclone could remain just offshore as it moves generally northward. Should Simon move inland, then it should dissipate quickly due to the mountainous terrain. However, if Simon were to stay offshore, then it would maintain hurricane intensity for a longer period of time. The current track forecast is similar to the previous one, with only a few small adjustments being made. Key Messages: 1. Catastrophic wind and life-threatening storm surge impacts are likely along a portion of the west-central coast of Mexico, and a Hurricane warning is in effect from Punta San Telmo to Punta Mita. Preparations to protect life and property should be completed today. 2. Heavy rainfall associated with Simon will impact portions of southwestern Mexico through this weekend. This rainfall will produce life-threatening flooding and mudslides, especially in areas of steep terrain. 3. Swells will affect portions of the southwestern and west-central coast of Mexico through the weekend. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 17.2N 104.6W 125 KT 145 MPH 12H 10/1800Z 17.8N 104.7W 135 KT 155 MPH 24H 11/0600Z 18.8N 104.9W 135 KT 155 MPH 36H 11/1800Z 20.0N 105.1W 120 KT 140 MPH...INLAND 48H 12/0600Z 21.7N 105.3W 70 KT 80 MPH...INLAND 60H 12/1800Z 23.1N 105.6W 30 KT 35 MPH...POST-TROP/INLAND 72H 13/0600Z...DISSIPATED $$ Forecaster Katz/Roberts NNNN

WDPN31 PGTW 100900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15E (NOLO) WARNING NR 079// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 30.9N 146.2E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 420 NM SOUTHEAST OF YOKOSUKA, JAPAN MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 07 KTS SIGNIFICANT WAVE HEIGHT: 20 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) THAT IS BECOMING INCREASINGLY ELONGATED, WITH SHALLOW CONVECTION CONFINED TO THE NORTHERN AND EASTERN PERIPHERY. THE CIRCULATION APPEARS TO HAVE BEGUN A TIGHT POLEWARD TURN. A 100301Z AMSR3 PASS INDICATED THAT THE CORE STRUCTURE HAS ERODED IN THE SOUTHWEST QUADRANT, AND A 100230Z OSCAT-3 PASS REVEALED AN ASYMMETRIC WIND FIELD WITH 40-45 KT WINDS CONFINED TO THE NORTHERN SEMICIRCLE. BASED ON THE OSCAT-3 DATA, THE INITIAL INTENSITY HAS BEEN LOWERED TO 45 KTS WITH HIGH CONFIDENCE. THIS ASSESSMENT IS HIGHER THAN THE SUBJECTIVE AND OBJECTIVE ESTIMATES. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE, HEDGED TOWARD THE RJTD AND RCTP FIXES. THE ENVIRONMENT IS LARGELY UNFAVORABLE, CHARACTERIZED BY 25-30 KTS OF VERTICAL WIND SHEAR (VWS), DRY AIR ENTRAINMENT, AND SEA SURFACE TEMPERATURES (SST) OF 25-26 DEGREES CELSIUS. STRONG POLEWARD OUTFLOW ALOFT PROVIDES INSUFFICIENT SUPPORT TO OFFSET THE OTHERWISE UNFAVORABLE ENVIRONMENT. INITIAL WIND RADII BASIS: SCATTEROMETER DATA CURRENT STEERING MECHANISM: WESTERN FLANK OF A LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR) CENTERED NEAR 32N 165E AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.0 - 30 KTS RJTD: T2.5 - 35 KTS RCTP: T1.5 - 25 KTS CIMSS ADT: 39 KTS AT 100540Z CIMSS D-MINT: 35 KTS AT 100401Z CIMSS D-PRINT: 38 KTS AT 100540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE VWS: 25-30 KTS SST: 25-26 CELSIUS OUTFLOW: STRONG POLEWARD OTHER FACTORS: DRY AIR ENTRAINMENT ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: HIGH INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 15E WILL CONTINUE TO EXECUTE A TIGHT POLEWARD TURN OVER THE NEXT 12 HOURS, ROUNDING THE STR AXIS AND TRANSITIONING TO A NORTHEASTWARD MOTION BY TAU 24. THE STRONGER DEEP-LAYER WESTERLIES WILL REMAIN FAR TO THE NORTH. THEREFORE, TS 15E WILL NOT GAIN SIGNIFICANT FORWARD SPEED AFTER RECURVATURE. OVER THE NEXT 24 HOURS, THE SYSTEM WILL INCREASINGLY COME UNDER THE INFLUENCE OF THE SOUTHERN PERIPHERY OF A JET STREAM AND LOW-LEVEL COLD AIR ADVECTION. VWS WILL INCREASE TO 30-40 KTS, WHICH WILL STRIP AWAY THE REMAINING CONVECTION AND LEAVE A FULLY EXPOSED LLCC. THE SYSTEM WILL UNDERGO EXTRATROPICAL TRANSITION (ETT) AT TAU 12 AND COMPLETE ETT BY TAU 24. HOWEVER, IF THE CIRCULATION FAILS TO REMAIN COHERENT, THE SYSTEM MAY DISSIPATE AND OPEN INTO A TROUGH. MODEL DISCUSSION: TRACK GUIDANCE IS IN REASONABLY GOOD AGREEMENT, WITH MOST MEMBERS DEPICTING A CONTINUED TURN TOWARD THE NORTH AND NORTHEAST OVER THE NEXT 24 HOURS. GOOGLE DEEPMIND LOSES THE CIRCULATION AFTER TAU 12, WHILE THE SPREAD AMONG THE DYNAMICAL AND REMAINING AI MODELS INCREASES AFTER TAU 12 DUE TO UNCERTAINTY ASSOCIATED WITH CONTINUED STRETCHING OF THE LLCC AND POTENTIAL DISSIPATION INTO A TROUGH. THE JTWC FORECAST TRACK IS SIMILAR TO THE PREVIOUS FORECAST AND IS POSITIONED NEAR THE MULTI-MODEL CONSENSUS (CONW) AND AI-MODEL MEAN, WHICH ARE VERY CLOSE TO EACH OTHER. THE INTENSITY AIDS DEPICT STEADY WEAKENING. THE JTWC INTENSITY FORECAST IS IN LINE WITH THIS SCENARIO AND IS SET BETWEEN THE DEEPMIND AND GFS SOLUTIONS. FORECAST CONFIDENCE: TRACK 00-72 HR: MEDIUM INTENSITY 00-72 HR: HIGH// …

WDPN33 PGTW 100900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 27W (KOGUMA) WARNING NR 022// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 22.2N 150.4E INITIAL INTENSITY: 115 KTS GEOGRAPHIC REFERENCE: 495 NM NORTH-NORTHEAST OF SAIPAN MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 13 KTS SIGNIFICANT WAVE HEIGHT: 42 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TYPHOON (TY) 27W MAINTAINS AN IMPRESSIVE APPEARANCE IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND IS LOCATED IN A FAVORABLE ENVIRONMENT CONSISTING OF LOW VERTICAL WIND SHEAR (VWS), WARM SEA SURFACE TEMPERATURES NEAR 29 DEGREES CELSIUS, AND MODEST UPPER-LEVEL DIVERGENCE. A CLEAR, CIRCULAR EYE MEASURING 20-25 NM IN DIAMETER IS EMBEDDED IN A CENTRAL DENSE OVERCAST (CDO) WITH A SMOOTH CIRRUS CANOPY. THE UPPER-LEVEL OUTFLOW IS EXPANDING IN ALL DIRECTIONS, INDICATIVE OF INTENSIFICATION. A 100624Z SSMIS PASS SHOWCASES A ROBUST EYEWALL WITH A FEW OUTER SPIRAL BANDS. EARLIER SAR PASSES BY RCM3 AND RSAT2 AT APPROXIMATELY 091940Z INDICATED PEAK SUSTAINED WINDS NEAR 110 KTS. SINCE THAT TIME, THE EYE HAS CLEARED, AND THE CLOUD TOP TEMPERATURES ASSOCIATED WITH THE CDO HAVE REMAINED NEAR -70 DEGREES CELSIUS. BASED ON THE IMPROVED CONVECTIVE SIGNATURE AND THE T6.0 DVORAK CLASSIFICATION FROM RJTD, THE INITIAL INTENSITY IS SET AT 115 KTS WITH MEDIUM CONFIDENCE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE WELL-DEFINED EYE IN THE MSI. INITIAL WIND RADII BASIS: SCATTEROMETER AND SAR DATA CURRENT STEERING MECHANISM: SOUTHWESTERN FLANK OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) POSITIONED FAR TO THE NORTHEAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS RJTD: T6.0 - 115 KTS CIMSS SATCON: 114 KTS AT 100540Z CIMSS ADT: 112 KTS AT 100540Z CIMSS AIDT: 109 KTS AT 100540Z CIMSS D-MINT: 112 KTS AT 100322Z CIMSS D-PRINT: 108 KTS AT 100540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 28-29 CELSIUS OUTFLOW: MODERATE RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TY 27W WILL CONTINUE ON A NORTHWESTWARD TRAJECTORY ALONG THE SOUTHWESTERN FLANK OF THE STR AND APPROACH A WEAKNESS IN THE STR PRODUCED BY TROPICAL STORM (TS) 15E. AS IT DOES, THE FORWARD SPEED WILL SLOW FROM ITS CURRENT SPEED OF 13 KTS TO 9-10 KTS NEAR RECURVATURE. THE SYSTEM WILL CROSS THE RIDGE AXIS AND RECURVE TOWARD THE NORTHEAST AROUND TAU 36. THEREAFTER, THE VORTEX WILL BECOME INCREASINGLY EMBEDDED IN DEEP-LAYER MID-LATITUDE WESTERLY FLOW AND ACCELERATE. TY 27W HAS ROUGHLY 12 HOURS REMAINING OVER OCEAN HEAT CONTENT (OHC) OF 75 KJ PER CM2. THE LOW-SHEAR ENVIRONMENT AND FAVORABLE OCEAN CONDITIONS WILL ENABLE TY 27W TO INTENSIFY A LITTLE MORE. AFTER TAU 12, THE SYSTEM WILL TRAVERSE WATERS WITH AN INCREASINGLY SHALLOW SUBSURFACE WARM WATER LAYER. COUPLED WITH THE 9-11 KTS OF TRANSLATION SPEED PREDICTED OVER THE NEXT 36 HOURS, THE DECLINING OHC WILL LEAD TO A WEAKENING TREND COMMENCING NEAR TAU 24. THE WEAKENING TREND WILL ACCELERATE AFTER TAU 24 AS THE VORTEX ENCOUNTERS PROGRESSIVELY COOLER WATERS, CROSSING THE 26 DEGREES CELSIUS ISOTHERM BY TAU 72. THE SYSTEM WILL BEGIN EXTRATROPICAL TRANSITION (ETT) BY TAU 96 AND COMPLETE ETT BY TAU 120. MODEL DISCUSSION: TRACK GUIDANCE IS IN EXCELLENT AGREEMENT THROUGH TAU 72, WITH A CROSS-TRACK SPREAD INCREASING FROM 50 NM AT TAU 36 TO 110 NM AT TAU 72. FROM TAU 72 TO TAU 120, GFS AND HAFS-A ARE THE POLEWARD OUTLIERS AND NAVGEM IS THE EQUATORWARD OUTLIER AND ALSO THE FASTEST. THE JTWC FORECAST TRACK IS POSITIONED ALONG THE CORE GROUPING OF MODELS THROUGH TAU 72 AND IS THEN ALIGNED WITH…