Polo, advisory 3
Tropical Storm Polo Advisory Number 3
Public advisory
National Hurricane Center · public advisory 3 · issued Sep 21, 8:41 AM UTCsource ↗
000 WTPZ32 KNHC 210841 TCPEP2 BULLETIN Tropical Storm Polo Advisory Number 3 NWS National Hurricane Center Miami FL EP172026 300 AM CST Mon Sep 21 2026 ...POLO EXPECTED TO RAPIDLY INTENSIFY... ...TROPICAL STORM WATCH ISSUED FOR A PORTION OF SOUTHWESTERN MEXICO... SUMMARY OF 300 AM CST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...15.5N 103.8W ABOUT 245 MI...395 KM S OF MANZANILLO MEXICO ABOUT 210 MI...340 KM SW OF ZIHUATANEJO MEXICO MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...NE OR 50 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has issued a Tropical Storm Watch from Tecpan de Galeana to Punta San Telmo. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Watch is in effect for... * Tecpan de Galeana to Punta San Telmo A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. The Tropical Storm Watch will likely be expanded westward later today or tonight. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 300 AM CST (0900 UTC), the center of Tropical Storm Polo was located near latitude 15.5 North, longitude 103.8 West. Polo is moving toward the northeast near 8 mph (13 km/h). A slow eastward or southeastward motion is expected later today and tonight. However, a sharp turn toward the west-northwest or northwest is expected by late Tuesday. On the forecast track, the core of Polo is expected to be near the coast of southwestern Mexico during the next few days. Maximum sustained winds have increased to near 45 mph (75 km/h) with higher gusts. Rapid intensification is forecast, and Polo is expected to become a hurricane later today and a major hurricane in a couple of days. Tropical-storm-force winds extend outward up to 60 miles (95 km) from the center. The estimated minimum central pressure is 1003 mb (29.62 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Tropical Storm Polo can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDEP2 and WMO header WTPZ42 KNHC. WIND: Tropical storm conditions are possible by Tuesday night or early Wednesday along portions of the southwestern coast of Mexico where a Tropical Storm Watch is now in effect. RAINFALL: Tropical Storm Polo is expected to produce rainfall totals of 4 to 8 inches, with isolated maximum totals up to 12 inches across coastal portions of the Mexican states of Guerrero, Michoacn, Colima, and Jalisco through Thursday. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. For a complete depiction of forecast rainfall associated with Tropical Storm Polo, please see the National Weather Service Storm Total Rainfall Graphic available at hurricanes.gov/graphics_ep2.shtml?rainqpf SURF: Swells generated by Polo are expected to begin affecting portions of the coast of southwestern Mexico on Tuesday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 600 AM CST. Next complete advisory at 900 AM CST. $$ Forecaster Cangialosi
Forecast discussion
National Hurricane Center · forecast discussion 3 · issued Sep 21, 8:48 AM UTCsource ↗
000 WTPZ42 KNHC 210848 TCDEP2 Tropical Storm Polo Discussion Number 3 NWS National Hurricane Center Miami FL EP172026 300 AM CST Mon Sep 21 2026 Deep convection associated with Polo has been gradually increasing over the past several hours. A recent GMI microwave pass indicates that Polo is developing a small core, which is an early indication that significant strengthening could be beginning. The latest satellite intensity estimates range from 35 to 45 kt, and based on that data and an earlier ASCAT pass, the initial intensity is increased to 40 kt. Environmental conditions appear very conducive for strengthening with the vertical wind shear expected to be less than 10 kt, mid-level humidities near or above 70 percent, and SSTs above 30 C during the next several days. These conditions, along with Polo's improving and compact structure, support rapid intensification. In fact, the SHIPS Rapid Intensification indices indicates that there is a near 90 percent chance of an increase in winds of at least 55 kt over the next 48 hours. The NHC intensity forecast is quite aggressive and calls for rapid intensification, and shows Polo becoming a hurricane later today and a major hurricane on Tuesday. This prediction is higher than the previous one, but below the latest HCCA guidance which shows Polo reaching category 5 status in about 48 hours. The storm will likely drift eastward or southeastward during the next day or so in weak steering currents. However, a sharp turn to the west-northwest or northwest is expected by late Tuesday when a mid-level ridge becomes established to the northeast of Polo. This pattern should bring the core of the storm near the coast of southwestern Mexico on Wednesday and Thursday, and then well south of the Baja California Peninsula on Friday. There is a very large spread in the model solutions in where, when, and how sharply Polo makes the turn. The GFS model is on the far south side of the guidance envelope while the Google DeepMind ensemble mean is on the northern edge. The NHC track forecast has been nudged northward, and is in best agreement with the corrected consensus HCCA model. It should be noted that given the complex steering pattern and model spread, confidence in the details of the track forecast is quite low. Key Messages: 1. Heavy rainfall associated with Tropical Storm Polo will impact coastal portions of southwest Mexico this week. This rainfall may produce life-threatening flooding and mudslides, especially in areas of steep terrain. 2. Polo is forecast to strengthen to a major hurricane while it moves closer to the coast of southwestern Mexico during the next few days. Although the core of the hurricane is forecast to stay offshore, it is too soon to determine the exact location or magnitude of impacts. Residents in southwestern Mexico should closely monitor its progress and updates to the forecast. A Tropical Storm Watch has been issued for portions of southwestern Mexico. FORECAST POSITIONS AND MAX WINDS INIT 21/0900Z 15.5N 103.8W 40 KT 45 MPH 12H 21/1800Z 15.5N 103.1W 60 KT 70 MPH 24H 22/0600Z 15.3N 102.5W 80 KT 90 MPH 36H 22/1800Z 15.3N 102.0W 100 KT 115 MPH 48H 23/0600Z 15.9N 102.4W 115 KT 130 MPH 60H 23/1800Z 16.6N 103.0W 125 KT 145 MPH 72H 24/0600Z 17.5N 104.1W 125 KT 145 MPH 96H 25/0600Z 18.7N 106.6W 120 KT 140 MPH 120H 26/0600Z 19.8N 109.0W 115 KT 130 MPH $$ Forecaster Cangialosi/Kelly
