1. Hurricane conditions and a dangerous storm surge are expected in portions of the Hurricane Warning area in the eastern Yucatan Peninsula of Mexico beginning during the next several hours. Preparations to protect life and property should be rushed to completion.

2. There is an increasing risk of hurricane conditions and dangerous storm surge in portions of eastern mainland Mexico beginning late Friday, and a Hurricane Watch has been issued for part of this area.

3. Through the weekend, heavy rainfall across central and northern portions of the Yucatan Peninsula and Veracruz State should lead to flash and urban flooding. In addition, the heavy rainfall from Grace will be capable of producing mudslides in Veracruz.

CHANGES WITH THIS ADVISORY: The Meteorological Service of Mexico has issued a Hurricane Watch for the coast of mainland Mexico from Puerto Veracruz to Cabo Rojo, and a Tropical Storm Watch from the coast of mainland Mexico north of Cabo Rojo to Puerto de Altamira. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for...
- Yucatan Peninsula of Mexico from Cancun to Punta Herrero, including Cozumel A Hurricane Watch is in effect for...
- The coast of mainland Mexico from Puerto Veracruz to Cabo Rojo A Tropical Storm Warning is in effect for...
- Yucatan Peninsula of Mexico from north of Cancun to Campeche
- Yucatan Peninsula of Mexico from south of Punta Herrero to Puerto Costa Maya A Tropical Storm Watch is in effect for...
- Southern coast Cuban province of Pinar del Rio, as well as Isla de la Juventud
- The coast of mainland Mexico north of Cabo Rojo to Puerto de Altamira A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical storm force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical storm force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Interests elsewhere in eastern mainland Mexico should monitor the progress of Grace. For storm information specific to your area, please monitor products issued by your national meteorological service.

Key messages for Grace can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC and on the web at www.hurricanes.gov/graphics_at2.shtml?key_messages.

WIND: Hurricane conditions are expected within the warning area in the Yucatan Peninsula of Mexico late tonight or early Thursday, with tropical storm conditions beginning during the next few hours. Hurricane and tropical storm conditions will spread inland the Yucatan Peninsula during the day Thursday. Hurricane conditions are possible in the hurricane watch area in mainland Mexico by by late Friday, and tropical storm conditions are possible in the tropical storm watch area in mainland Mexico by late Friday. Tropical storm conditions are possible along the southern coast of Cuba within the watch area for the next several hours.

RAINFALL: The system is expected to produce the following rainfall amounts: Over central and northern portions of the Yucatan Peninsula...4 to 8 inches of rain with isolated maximum totals of 12 inches are expected through Friday. Heavy rainfall from Grace will likely result in areas of flash and urban flooding. Over central to northern Veracruz...5 to 10 inches of rain with isolated maximum totals of 15 inches are expected from Friday through Sunday. Heavy rainfall from Grace will likely result in areas of flash and urban flooding, and will also be capable of producing mudslides.

STORM SURGE: A dangerous storm surge will raise water levels by as much as 3 to 5 ft above normal tide levels along the immediate coast near and to the north of where the center makes landfall in the northeastern Yucatan Peninsula late tonight or early Thursday and along the eastern mainland coast of Mexico Friday night or early Saturday. Near the coast, the surge will be accompanied by large and destructive waves.

SURF: Swells generated by Grace will spread westward from Jamaica and the Cayman Islands to the southern coast of Cuba and the Yucatan Peninsula of Mexico through Thursday. These swells are likely to cause life threatening surf and rip current conditions. Please consult products from your local weather office.

At 1000 PM CDT (0300 UTC), the center of Hurricane Grace was located near latitude 19.8 North, longitude 85.6 West. Grace is moving toward the west near 18 mph (30 km/h). A general west northwestward to westward motion is expected through Friday, followed by a general westward to west southwestward motion. On the forecast track, Grace is expected to make landfall in the eastern Yucatan Peninsula during the next six to twelve hours, move across the Yucatan Peninsula on Thursday, and move over the southwest Gulf of Mexico late Thursday through Friday. Maximum sustained winds are near 80 mph (130 km/h) with higher gusts. Some strengthening is expected before landfall on the Yucatan peninsula. Grace is expected to weaken as it crosses Yucatan, but re intensification is expected when the center reaches the Gulf of Mexico. Hurricane force winds extend outward up to 35 miles (55 km) from the center and tropical storm force winds extend outward up to 140 miles (220 km). The latest minimum central pressure reported by an Air Force Reserve Hurricane Hunter aircraft is 988 mb (29.18 inches).

Grace has become a bit better organized during the past several hours. Cuban radar data indicates that the eye and eyewall have become better defined, and reports from Air Force Reserve and NOAA Hurricane Hunter aircraft show that the inner core circulation has become better defined. There are also occasional attempts at eye formation in satellite imagery. However, these changes have not yet resulted in significant intensification, with the maximum winds remaining near 70 kt and the central pressure hovering near 988 mb. One possible restraint on development is a dry slot that is seen wrapping around the central core in both satellite imagery and Cuban radar data.

The center has jogged a little to the left during the past few hours, and the initial motion is now 280/16. The hurricane should continue to move generally westward to west-northwestward for the next 24-36 h, followed by a westward to west-southwestward motion from 36-48 h. This motion should bring the center over the Yucatan Peninsula of Mexico during the next 12 h, followed by passage across the southwestern Gulf of Mexico or the Bay of Campeche to a second landfall in mainland Mexico between 48-60 h. After that, the cyclone should continue moving into the mountains of Mexico until it dissipates. The new forecast track is nudged a little south of the previous forecast, and it lies near the various consensus models.

Except for the aforementioned dry slot, conditions appear favorable for intensification before landfall on the Yucatan peninsula. While not explicitly show in the intensity forecast, Grace could reach an intensity of 75-80 kt before it reaches Yucatan. The cyclone should weaken some as it crosses the peninsula, then re-intensify over the Gulf of Mexico until it reaches mainland Mexico. After final landfall in Mexico, Grace is expected to quickly weaken and dissipate over the mountains of Mexico just after 72 h. The remnants of Grace are likely to emerge in the Pacific and possibly re-develop there, but the uncertainty of whether this will be the original center or a new center precludes forecast points over the Pacific at this time.

A Hurricane Watch and a Tropical Storm Watch have been issued for portions of mainland Mexico.