ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM Tropical Storm Cristobal Discussion Number 18 NWS National Hurricane Center Miami FL AL032020 1000 PM CDT Fri Jun 05 2020 The NOAA and Air Force Hurricane Hunters have been investigating Cristobal this evening and they have found that the storm is a little stronger. The pressure has dropped to 998 mb and a combination of flight-level, SFMR, and dropsonde data support a wind speed of about 40 kt. Cristobal continues to have a large and asymmetric appearance with most of the showers and thunderstorms and strong winds to the north and east of the center. The storm is moving northward at a slightly faster pace, about 12 kt. A south to north steering flow between a deep-layer ridge over the western Atlantic and a mid- to upper-level trough over the western Gulf of Mexico should cause Cristobal to continue moving generally northward for the next couple of days. This motion should take the center of the storm across the Louisiana coast by Sunday night. Around the landfall time, a slight turn to the northwest is expected as a mid-level ridge moves across the central and eastern U.S. Overall, the models are in fairly good agreement and only small changes were made to the previous NHC track forecast. This prediction lies near the middle of the guidance envelope. Cristobal will likely continue to slowly strengthen until it makes landfall along the northern Gulf coast in a couple of days. However, the broad structure of the cyclone, dry air on the west side of the system, and moderate wind shear should prevent a significant amount of intensification. The NHC intensity forecast is largely an update of the previous one and is close to the various consensus models. Cristobal is likely to remain a broad and asymmetric storm when it makes landfall. Therefore, users are urged to not focus on the exact forecast path as the associated winds, storm surge, and rainfall will extend well to the east of 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 for another day or so. 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. There is a danger of life-threatening storm surge outside of the Hurricane and Storm Damage Risk Reduction System from the Mouth of the Mississippi River to Ocean Springs, Mississippi, and a Storm Surge Warning is in effect for those areas. Life-threatening storm surge remains possible along the Florida Big Bend and in other portions of southern and southeastern Louisiana where a Storm Surge Watch is in effect. Residents in these locations should follow advice given by local emergency officials. 3. Tropical storm force winds are expected by late Saturday night along the northern Gulf Coast from southeastern Louisiana to the western Florida Panhandle, including metropolitan New Orleans, and a Tropical Storm Warning is in effect for this area. These winds will arrive well in advance of and extend well east of Cristobal’s center. 4. Heavy rainfall will spread into portions of the Gulf Coast, from east Texas to Florida this weekend into early next week, with areas of flash flooding. Significant flooding will be possible on smaller tributaries, especially where heavier rainfall occurs over portions of Louisiana and Mississippi. FORECAST POSITIONS AND MAX WINDS INIT 06/0300Z 22.7N 90.1W 40 KT 45 MPH 12H 06/1200Z 24.1N 90.3W 45 KT 50 MPH 24H 07/0000Z 25.9N 90.3W 50 KT 60 MPH 36H 07/1200Z 27.7N 90.2W 50 KT 60 MPH 48H 08/0000Z 29.5N 90.8W 45 KT 50 MPH...INLAND 60H 08/1200Z 31.7N 91.9W 35 KT 40 MPH...INLAND 72H 09/0000Z 34.4N 92.8W 25 KT 30 MPH...INLAND 96H 10/0000Z 42.0N 90.0W 20 KT 25 MPH...POST-TROP/INLAND 120H 11/0000Z...DISSIPATED $$ Forecaster Cangialosi NNNN