Tropical Storm Cristobal Forecast Discussion Number 20

By | June 6, 2020

Issued at 1000 AM CDT Sat Jun 06 2020


000
WTNT43 KNHC 061448
TCDAT3
 
Tropical Storm Cristobal Discussion Number  20
NWS National Hurricane Center Miami FL       AL032020
1000 AM CDT Sat Jun 06 2020
 
Cristobal's satellite presentation continues to lack the appearance 
of a classic tropical cyclone, with a large curved band over the 
northern semicircle and little deep convection near the center.  
The latest flight-level and SFMR-observed surface wind observations 
from an Air Force Hurricane Hunter aircraft support a current 
intensity of 45 kt.  Based on the poorly-organized state of 
the system, some dry air entrainment, and interaction with an 
upper-level low, only some slow strengthening is forecast, as in 
the previous advisories.  The NHC intensity forecast remains in 
good agreement with the model consensus.

The storm is moving northward at a slightly slower 10 kt.  There 
has not been much change in the track forecast or forecast 
reasoning.  Cristobal should continue northward through a weakness 
in the subtropical ridge until tomorrow evening, bringing the 
center to the northern Gulf coast in about 36 hours.  Later, a turn 
to the north-northwest, and then back to the north is forecast as 
the cyclone moves between a mid-level ridge and a trough approaching 
the central United States.  In 3-4 days, the post-tropical system 
should accelerate north-northeastward on the east side of the trough
and move into Canada. 
  
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. 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 Cristobals 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.
 
4. Damaging and deadly flooding was already occurring in portions of 
Mexico and Central America. Additional rainfall from Cristobal will 
continue to slowly subside, however life-threatening flash floods 
and mudslides will still be possible through today. Refer to 
products from your local weather office for more information.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/1500Z 24.2N  90.1W   45 KT  50 MPH
 12H  07/0000Z 25.6N  90.2W   45 KT  50 MPH
 24H  07/1200Z 27.4N  90.2W   50 KT  60 MPH
 36H  08/0000Z 29.3N  90.7W   50 KT  60 MPH...ON THE COAST
 48H  08/1200Z 31.5N  91.5W   35 KT  40 MPH...INLAND
 60H  09/0000Z 34.5N  92.5W   25 KT  30 MPH...INLAND
 72H  09/1200Z 38.0N  92.3W   20 KT  25 MPH...POST-TROP/INLAND
 96H  10/1200Z 47.5N  86.0W   20 KT  25 MPH...POST-TROP/EXTRATROP
120H  11/1200Z...MERGED WITH EXTRATROPICAL LOW
 
$$
Forecaster Pasch
 

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