ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Tropical Storm Simon Discussion Number 34 NWS National Hurricane Center Miami FL EP202026 200 PM MST Thu Oct 15 2026 Simon continues to produce an area of deep convection, though this activity has lacked a ton of organization today, and appears to still be displaced to the west of the center of circulation. A RCM-2 synthetic aperture radar (SAR) pass that became available after the prior advisory indicated that most of this convective activity was also occurring outside of its radius of maximum winds, and has done little to aid the small circulation. In fact, the peak winds retrieved from the SAR was only 47 kt. This information, combined with a Metop-B scatterometer pass that had a peak wind of 39 kt is justification to bring Simon's intensity down to 45 kt this advisory, and this may still be generous. Simon has been drifting rather aimlessly today, and my best guess at an estimated motion is 320/1 kt. It has been a tough few days trying to forecast Simon's track, but the model guidance this cycle is finally coming into better agreement showing that as Simon becomes a more vertically shallow cyclone, it will primarily be steered by the low-level flow. To that end, a weak low-level trough is forecast to drop equatorward to the west of Simon as a strong pressure gradient develops over northern Mexico as surface ridging builds in behind a frontal boundary. This flow should help to finally draw Simon back to the northwest with a speed up in its forward motion. The latest NHC track forecast is shifted once again a little further west but also faster, following the latest trends in the reliable HFIP Corrected Consensus Approach (HCCA) and Google DeepMind ensemble mean (GDMI). While the shear over Simon is currently low, it has not taken advantage of these more favorable conditions, likely due to the proximity of dry air preventing the convection from organizing. The vertical wind shear is soon expected to increase significantly out of the southwest as a deep-layer trough located over the southwestern United States cuts off and retrogrades back westward. Simon has already been sensitive to less than pristine conditions, and this increase in shear will likely be the storm's demise. The latest NHC forecast now shows gradual weakening continuing over the next 24-36 h, with Simon becoming a remnant low in 48 h, and fully dissipating in 72 h. If the latest ECMWF forecast is correct, this could occur sooner than forecasted here. FORECAST POSITIONS AND MAX WINDS INIT 15/2100Z 19.3N 108.2W 45 KT 50 MPH 12H 16/0600Z 19.8N 108.7W 40 KT 45 MPH 24H 16/1800Z 20.8N 110.0W 35 KT 40 MPH 36H 17/0600Z 22.0N 111.9W 30 KT 35 MPH 48H 17/1800Z 23.1N 113.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 18/0600Z 24.5N 115.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 18/1800Z...DISSIPATED $$ Forecaster Papin NNNN

ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM Hurricane Trudy Discussion Number 10 NWS National Hurricane Center Miami FL EP212026 300 PM CST Thu Oct 15 2026 Trudy's intensification appears to have temporarily paused. An Air Force Reserve Hurricane Hunter aircraft investigated the hurricane a few hours ago and reported maximum 700-mb flight-level winds of 84 kt and a central pressure near 978 mb. Satellite imagery shows an attempt to form an eye, but it has not yet fully cleared out. The various satellite intensity estimates have changed little over the past few hours, and the initial intensity remains 80 kt based on them and the aircraft data. The satellite imagery suggests a tongue of dry air is wrapping into the cyclone around the north side of the central dense overcast, and this may be responsible for the pause in the development. The initial motion is north-northwestward or 345/5 kt. The hurricane is currently heading for a weakness in the subtropical ridge caused by a mid- to upper-level trough extending from the Yucatan Peninsula westward to central Mexico. During the next 36 h, this feature should weaken and move eastward, allowing a mid- to upper-level ridge to develop over Mexico. This evolution should cause Trudy to turn northwestward roughly parallel to the coast of Mexico. The bulk of the track guidance keeps the center just offshore of the coast. However, any track to the right of the official forecast - such as shown by the GFS - would bring the center onshore. After 72 h, low- to mid-level ridging to the north of the cyclone should steer it slowly westward. The new track forecast is a little to the east of the previous forecast through 36 h, similar to the previous forecast from 36-72 h, and a little north of the previous forecast from 72-120 h. Except for the apparent tongue of dry air, conditions appear favorable for steady to rapid development during the next 24-36 h. The new intensity forecast keeps the peak intensity of 125 kt from the previous advisory, which is near or a little above the upper edge of the intensity guidance. After 36 h, there should be increasing southwesterly shear that will likely halt development. Even with the forecast track keeping the center offshore, the cyclone will likely be close enough to land to cause the cyclone to weaken. However, any track to the left and farther offshore of the current forecast would let Trudy stay stronger than currently forecast, while any track that the brings the center inland would cause rapid weakening and possibly dissipation. Beyond 72 h, strong shear should cause continued weakening even though the center is moving away from land. The intensity forecast follows the overall trend of the guidance, and it is near the upper edge of the guidance. KEY MESSAGES: 1. Trudy is forecast to be a major hurricane as it approaches the coast of southwestern and west-central Mexico this weekend. There is an increasing risk of wind, rain, and storm surge impacts. A Hurricane Watch and a Tropical Storm Warning have been issued for a portion of the southwestern Mexican coast, and additional watches will likely be required further up the coast tonight or Friday. 2. Heavy rainfall associated with Trudy will impact the southwest Mexican coast between Guerrero and Jalisco through the weekend. This rainfall may produce life-threatening flooding and mudslides by the weekend along and near the southwest Mexican coast in Michoacán, Colima, and Jalisco, especially in areas along steep terrain. 3. Large swells will begin to affect portions of the coast of southwestern Mexico Friday and continue through the weekend. These swells could cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 15/2100Z 13.7N 101.7W 80 KT 90 MPH 12H 16/0600Z 14.3N 101.9W 95 KT 110 MPH 24H 16/1800Z 15.2N 102.2W 115 KT 130 MPH 36H 17/0600Z 16.3N 102.9W 125 KT 145 MPH 48H 17/1…

WDPN32 PGTW 152100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 29W (CHAMPI) WARNING NR 006// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 11.5N 156.5E INITIAL INTENSITY: 40 KTS GEOGRAPHIC REFERENCE: 692 NM EAST OF ANDERSEN AFB MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 10 KTS SIGNIFICANT WAVE HEIGHT: 15 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL STORM (TS) 29W FORMING A NASCENT CENTRAL DENSE OVERCAST THAT IS OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC) BELOW. THE BULK OF DEEP CONVECTION REMAINS WEST OF THE SYSTEM, IMPACTED BY THE EASTERLY VERTICAL WIND SHEAR (VWS). A THIN LINE OF CIRRUS OUTFLOW APPEARS TO BE ATTEMPTING UPSHEAR EXPANSION, A SIGN THE SYSTEM COULD BE BEGINNING TO RESIST THE PRESSURE AND CONSOLIDATE. THE 151746Z SSMIS MICROWAVE DATA REVEALS A COMPACT SURFACE CIRCULATION WITH THE SMALL PATCH OF CENTRAL CONVECTION DISPLACED TO THE WEST, CONFIRMING THE SLIGHT WESTWARD VERTICAL TILT. ENVIRONMENTAL ANALYSIS REVEALS A FAVORABLE ENVIRONMENT, CHARACTERIZED BY LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS), WARM (29-30 C) SEA SURFACE TEMPERATURES (SST), DECENT (75-100 KJ PER CM SQUARED) OCEAN HEAT CONTENT (OHC) AND MODERATE OUTFLOW SUPPORTED BY THE EASTERLY FLOW. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED SSMIS DATA. THE INITIAL INTENSITY OF 40 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AGENCY DVORAK FIXES AND THE AUTOMATED CIMSS INTENSITY ESTIMATES LISTED BELOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) CENTERED TO THE NORTH AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS RJTD: T2.5 - 35 KTS RCTP: T3.0 - 45 KTS CIMSS SATCON: 40 KTS AT 151740Z CIMSS ADT: 49 KTS AT 151740Z CIMSS AIDT: 39 KTS AT 151740Z CIMSS D-MINT: 33 KTS AT 151722Z CIMSS D-PRINT: 43 KTS AT 151810Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE WESTWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 29W (CHAMPI) IS FORECAST TO CONTINUE STEADILY TRACKING WEST-NORTHWESTWARD THROUGH TAU 36 WHILE IT REMAINS ON THE SOUTHERN PERIPHERY OF THE STEERING STR CENTERED FAR TO THE NORTH. AT ABOUT TAU 36, A DEEP-LAYER TROUGH IS EXPECTED TO PASS TO THE NORTH, WEAKENING THE RIDGE AND FORCING IT TO RETREAT EASTWARD. SIMULTANEOUSLY, A SECOND STR IS EXPECTED TO BUILD IMMEDIATELY FOLLOWING THE PASSAGE OF THE TROUGH AND ASSUMING STEERING INFLUENCE OVER 29W FROM TAU 36-120. IT IS EXPECTED TO BE A SMOOTH TRANSITION FROM ONE STR TO THE OTHER, AND THE NEW STEERING ENVIRONMENT WILL MAINTAIN THE STEADY WEST-NORTHWESTWARD TRACK FOR THE REMAINDER OF THE FORECAST PERIOD. REGARDING INTENSITY, 29W IS FORECAST TO STEADILY INTENSIFY THROUGH TAU 12 WHILE THE SYSTEM CONTINUES TO CONSOLIDATE AND ORGANIZE. FOLLOWING TAU 24, 29W IS FORECAST TO UNDERGO A PROLONGED PERIOD OF RAPID INTENSIFICATION (RI) IN RESPONSE TO THE INCREASINGLY FAVORABLE ENVIRONMENT IT WILL ENCOUNTER BETWEEN TAU 24-72. THOUGH VWS IS EXPECTED TO REMAIN APPROXIMATELY 15KTS THROUGH TAU 96, THE EQUATORWARD AND WESTWARD OUTFLOW CHANNELS ARE EXPECTED TO STRENGTHEN AND CHAMPI IS EXPECTED TO TRACK THROUGH A REGION OF SLIGHTLY HIGHER (100-125 KJ PER CM SQUARED) OHC. AFTER TAU 72, 29W WILL CONTINUE TO INTENSIFY GRADUALLY UNTIL PEAKING AT TAU 96. AFTER THAT POINT, 29W WILL LIKELY MAINTAIN A HIGH INTENSITY, AS ENVIRONMENTAL CONDITIONS WILL CONTINUE TO IMPROVE. NAMELY, VWS IS EXPECTED TO DROP TO LESS THAN 10KT…