ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM Tropical Storm Cristobal Discussion Number 21 NWS National Hurricane Center Miami FL AL032020 400 PM CDT Sat Jun 06 2020 Cristobal continues to lack the appearance and structure of a typical tropical cyclone. In fact, the large radius of maximum wind and convective bands well removed from the center are more characteristic of a subtropical cyclone. Based on earlier Air Force Hurricane Hunter observations, the maximum winds are about 45 kt. The central pressure has held steady during the last couple of fixes of the aircraft mission, suggesting no significant strengthening since this morning. Since the system is not well organized and is likely to continue to ingest some more dry air, only a little more strengthening is expected until landfall. The official intensity forecast is unchanged and remains close to the model consensus. The cyclone remains on track and is moving northward, or 360/10 kt. The track forecast philosophy remains unchanged. The system should continue northward between two mid-level anticyclones until it nears the northern Gulf coast. After landfall, a slight building of a ridge to the northeast should induce a turn toward the north-northwest. In 3-4 days, the post-tropical cyclone should accelerate north-northeastward ahead of a mid-tropospheric trough. Thereafter, the global models suggest that the system should merge with an extratropical cyclone near the Great Lakes. The official track forecast is in good agreement with the dynamical model consensus and is also close to the latest GFS solution. Cristobal is likely to remain a broad and asymmetric storm when it makes landfall. Therefore, one should not focus on the exact forecast track, as the associated winds, storm surge, and rainfall will extend well away the center. Key Messages: 1. 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 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. 2. Tropical storm force winds are expected by late tonight along the northern Gulf Coast from central 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. 3. Heavy rainfall will continue across west and north Florida today, spreading from east to west across the eastern and central Gulf Coast from the Florida Panhandle into Louisiana today into Sunday. This heavy rain will move into the Lower Mississippi Valley on Monday. Significant flooding will be possible on smaller streams, especially where heavier rainfall occurs over portions of the Gulf Coast and Lower Mississippi Valley. FORECAST POSITIONS AND MAX WINDS INIT 06/2100Z 25.2N 90.2W 45 KT 50 MPH 12H 07/0600Z 26.7N 90.2W 50 KT 60 MPH 24H 07/1800Z 28.5N 90.4W 50 KT 60 MPH 36H 08/0600Z 30.6N 91.1W 40 KT 45 MPH...INLAND 48H 08/1800Z 33.0N 92.3W 30 KT 35 MPH...INLAND 60H 09/0600Z 36.0N 92.8W 25 KT 30 MPH...INLAND 72H 09/1800Z 40.5N 91.5W 20 KT 25 MPH...POST-TROP/INLAND 96H 10/1800Z 49.0N 88.0W 20 KT 25 MPH...POST-TROP/EXTRATROP 120H 11/1800Z...MERGED WITH EXTRATROPICAL LOW $$ Forecaster Pasch NNNN