1. A tropical wave is producing a large area of disorganized showers
and thunderstorms several hundred miles south of the coast of
southwestern Mexico. Environmental conditions appear conducive for
development of this system, and a tropical depression is likely to
form this weekend. This disturbance is expected to move
west-northwestward at about 15 mph well off the coast of Mexico for
the next several days.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...80 percent.
1. A large area of disturbed weather associated with a tropical wave is
located several hundred miles south of the southwestern coast of
Mexico. This system is showing signs of organization and a broad
surface low has developed. Environmental conditions appear conducive
for further development and a tropical depression is likely to form
this weekend. The low is expected to move west-northwestward at
about 15 mph, remaining well off the coast of Mexico.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...90 percent.
WTPN21 PHNC 050130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 95E)//
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
180 NM EITHER SIDE OF A LINE FROM 10.7N 106.2W TO 13.5N 113.4W
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT
IMAGERY AT 050100Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 10.8N 106.9W. THE SYSTEM IS MOVING WESTWARD AT 16 KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 95E) HAS PERSISTED NEAR
10.8N 106.9W, APPROXIMATELY 1425 NM SOUTH-SOUTHEAST OF SAN DIEGO.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A BROAD LLC
WITH FRAGMENTED CONVECTIVE BANDING OVER THE NORTH PERIPHERY. THE
UPPER LEVEL ENVIRONMENT IS FAVORABLE FOR DEVELOPMENT WITH LOW
VERTICAL WIND SHEAR (10-15 KNOTS), GOOD EQUATORWARD OUTFLOW, AND
FAIR POLEWARD OUTFLOW ENHANCED BY AN UPPER LOW NORTH OF THE INVEST.
SURROUNDING SEA SURFACE TEMPERATURES ARE FAVORABLE AT 28-29C. GLOBAL
MODELS INDICATE STEADY INTENSIFICATION OVER THE NEXT 24-36 HOURS AS
THE SYSTEM TRACKS WEST-NORTHWESTWARD. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
Tropical Storm Cosme Discussion Number 1
NWS National Hurricane Center Miami FL EP032019
800 AM PDT Sat Jul 06 2019
The broad area of low pressure that we have been monitoring for
several days has finally consolidated into a tropical storm.
Satellite images show that a well-defined center is present on the
western side of an area of deep convection which has been
getting closer to the center. The initial wind speed is set to 45
kt in agreement with the overnight scatterometer data, which is
higher than what Dvorak-only estimates would suggest.
Shear near Cosme has been decreasing during the overnight hours,
with cirrus cloud motions suggesting that easterly flow is
overspreading the circulation. However, it will take some time for
the large cyclone to overcome the very dry mid-level air near and
west of the core. In addition, Cosme has only about 36 hours over
lukewarm SSTs before reaching cool waters. These factors suggest
little significant strengthening this weekend, and a gradual
weakening early next week due to sub-26C waters and higher shear.
Only the HWRF shows any significant increase in wind speed, with the
rest of the models holding Cosme's intensity flat or decreasing
during the next few days. The official intensity forecast goes with
the latter solution, not too far from the model consensus.
An uncertain estimate of initial motion is 290/12. Cosme should
be steered to the west-northwest for the next day or so due to a
subtropical ridge over Mexico. However all of the models show a
break in the ridge forming between 120-130W, which will likely
induce a motion more to the northwest by Monday. There isn't a lot
of agreement, however, on exactly when that turns occurs, with the
GFS-based guidance and UKMET turning the system the system earlier
than the ECMWF and most of its ensemble. I don't have a lot of
reason to favor either solution at this time, so the forecast will
stay close to the eastern Pacific track model consensus TVCE. Based
on SSTs and model-simulated satellite data, Cosme should become a
non-convective remnant low in about 3 days.