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Tropical Storm Cristobal Forecast Discussion Number 11
2020-06-04 10:44:42| National Hurricane Center (Atlantic)
Issued at 400 AM CDT Thu Jun 04 2020 000 WTNT43 KNHC 040844 TCDAT3 Tropical Storm Cristobal Discussion Number 11 NWS National Hurricane Center Miami FL AL032020 400 AM CDT Thu Jun 04 2020 Satellite imagery and radar data from Sabancuy, Mexico indicate that Cristobal has resumed a southeastward drift and moved farther inland. There is no data from near the core of the storm, so the maximum intensity is set to a possibly generous 35 kt based on continuity from the previous advisory and earlier scatterometer data that showed 35 kt winds over water to the northwest of the center. The initial motion is a drifting 125/2 kt. A slow eastward motion is expected today. After that, southerly flow associated with a strengthening ridge over the western Atlantic and a developing mid-/upper-level trough over northern Gulf of Mexico should turn Cristobal northward with some increase in forward speed. Later in the forecast period, a north-northwestward or northward motion is expected as Cristobal interacts with the trough, with most of the track forecast guidance bringing the system to the northern Gulf coast between 96-120 h. The new forecast track has no significant changes from the previous track, and it lies near the various consensus models. Cristobal should weaken to a depression in the next few hours as the center drifts farther inland. Little subsequent change in strength is likely through 24 h due to much of the circulation remaining over water. By 36 h, the global model guidance suggest that winds will increase over the Gulf of Mexico well northeast of the center, so the new intensity forecast calls for Cristobal to regain tropical storm status at that time. From 48-120 h, Cristobal is forecast to interact with the trough over the Gulf of Mexico, which is likely to cause dry air entrainment and some shear. The intensity guidance suggests these conditions will allow only gradual intensification, so the new forecast follows the trend of the previous forecast in showing a peak intensity of 50 kt before landfall on the northern Gulf coast. The global models indicate that Cristobal's wind field will expand as the cyclone deepens over the south-central Gulf of Mexico. Therefore, the size of the NHC wind radii have again been increased primarily over the eastern semicircle at 36-72 hours. Indeed, the models suggest that when the storm reaches the northern Gulf coast the worst conditions may occur at a large distance from the center. Key Messages: 1. Damaging and deadly flooding was already occurring in portions of Mexico and Central America. Cristobal is expected to produce additional extreme rainfall amounts through the end of the week. The heaviest additional rainfall is expected over far southern Mexico and portions of the Yucatan Peninsula, while also extending along the Pacific coast from Chiapas to Guatemala and El Salvador. This rainfall could cause widespread life-threatening flash floods and mudslides. Refer to products from your local weather office for more information. 2. Even though Cristobal is inland, tropical storm conditions will continue along and near the coast of Mexico for a few more hours, especially over western Campeche, eastern Tabasco, and northern Chiapas states. 3. Cristobal is forecast to re-emerge over the southern Gulf of Mexico on Friday and move northward over the central and northern Gulf of Mexico over the weekend. There is a risk of storm surge, heavy rainfall, and wind impacts beginning over the weekend along portions of the U.S. Gulf Coast from Texas to the Florida Panhandle. While it is too soon to determine the exact location, timing, and magnitude of these impacts, interests in these areas should monitor the progress of Cristobal and ensure they have their hurricane plan in place. FORECAST POSITIONS AND MAX WINDS INIT 04/0900Z 17.9N 91.3W 35 KT 40 MPH...INLAND 12H 04/1800Z 18.0N 91.0W 30 KT 35 MPH...INLAND 24H 05/0600Z 18.7N 90.5W 30 KT 35 MPH...INLAND 36H 05/1800Z 20.2N 90.4W 35 KT 40 MPH...INLAND 48H 06/0600Z 22.1N 90.5W 40 KT 45 MPH...OVER WATER 60H 06/1800Z 23.9N 90.7W 45 KT 50 MPH 72H 07/0600Z 25.8N 90.8W 50 KT 60 MPH 96H 08/0600Z 29.5N 91.5W 50 KT 60 MPH 120H 09/0600Z 34.0N 92.5W 30 KT 35 MPH...INLAND $$ Forecaster Beven
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