Official Discussion issued by the National Hurricane Center

Cristobal (AL032020) DATA RELEASED: 6/5/2020 10:00:00 PM UTC

Copy of official data

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 CristobalG«÷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