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 010 
 WTPZ42 KNHC 060859
 TCDEP2
 
 Tropical Storm John Discussion Number   3
 NWS National Hurricane Center Miami FL       EP122018
 300 AM MDT Mon Aug 06 2018
 
 The convective pattern of John has become significantly better
 organized during the past several hours, with a large central dense
 overcast forming and cloud top temperatures to -85C.  A 0706Z GPM
 microwave pass shows the rapid development of an inner core since
 the previous pass 6 hours ago, along with impressive curved banding
 features.  A blend of the satellite intensity estimates gave 45 kt
 at 0600 UTC, but given the increase in organization since that time,
 the advisory wind speed is set to 50 kt.
 
 All systems are go for the rapid intensification of John in an
 environment of very warm SSTs, high mid-level moisture and low wind
 shear.  With the inner core formation, John will likely strengthen
 quickly until it reaches cooler waters after 48 hours. The various
 rapid intensification aids are about as high as they get, roughly 60
 to 90 percent depending on the threshold, increasing the confidence
 in the forecast.   Thus the new NHC wind speed prediction is raised
 from the previous one, and calls for rapid intensification through
 48 hours.  It should be noted that even though the NHC forecast is
 rather bullish, the corrected consensus aids, the SHIPS and LGEM
 models all show an even higher peak intensity.
 
 The GPM pass helped set the initial motion at 300/7 kt, somewhat to
 the left of the previous estimate.  Model guidance remains in fairly
 good agreement that John should move northwestward soon at an
 increasing forward speed toward a weakness in the subtropical ridge.
 While some interaction with TS Ileana is anticipated, the much
 larger John should dominate, leading to perhaps a temporary
 slowdown.  The latest NHC forecast is shifted to the west in the
 first couple of days, following the trend of the model guidance, but
 ends up very close to the previous forecast at day 5.  The UKMET is
 significantly farther west, perhaps due to it having the two
 tropical cyclones analyzed with nearly the same size, and little
 weight is placed on that model for the official forecast.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  06/0900Z 15.1N 107.3W   50 KT  60 MPH
  12H  06/1800Z 15.6N 108.1W   65 KT  75 MPH
  24H  07/0600Z 16.3N 109.0W   80 KT  90 MPH
  36H  07/1800Z 17.5N 110.2W   95 KT 110 MPH
  48H  08/0600Z 18.8N 111.7W  110 KT 125 MPH
  72H  09/0600Z 21.8N 115.3W   95 KT 110 MPH
  96H  10/0600Z 24.5N 119.5W   65 KT  75 MPH
 120H  11/0600Z 26.5N 124.0W   40 KT  45 MPH...POST-TROPICAL
 
 $$
 Forecaster Blake
 
 
 
 011 
 WTPZ41 KNHC 060859
 TCDEP1
 
 Tropical Storm Ileana Discussion Number   7
 NWS National Hurricane Center Miami FL       EP112018
 400 AM CDT Mon Aug 06 2018
 
 A strong burst of deep convection consisting of some cloud top
 temperatures of -85 to -90 deg C near the center has developed
 during the past several hours. A Central Dense Overcast (CDO)
 feature has developed as a result, and the Acapulco, Mexico, radar
 indicates that a banded eye feature has developed in the center of
 the CDO. Based on the radar data and a UW-CIMSS ADT estimate of
 T3.6/57 kt, the initial intensity has been increased to 55 kt.
 
 Ileana has begun to accelerate around the eastern periphery of
 rapidly developing Tropical Storm John, and initial motion estimate
 is now 310/15 kt. Little change was made to the previous forecast
 track other than to nudge the forecast a little more to the right,
 closer to Mexico, due to the more eastward initial position based
 on the aforementioned radar data. Ileana is expected to continue
 moving northwestward between Tropical Storm John and a deep-layer
 ridge over Mexico. The NHC model guidance remains in good agreement
 on this track scenario until dissipation or absorption occurs in
 about 72 hours, and the new forecast track lies close to the HCCA
 and FSSE consensus track model solutions.
 
 The shear is forecast to decrease to around 15 kt over the next 24
 hours, and the global model fields actually indicate that the shear
 could be lower than that since most of the stronger outflow from
 Tropical Storm John will remain north of Ileana. Based on the
 expected lower shear conditions, a very moist atmosphere, SSTs
 near 30 deg C, and the much improved internal structure noted in
 radar data, Ileana is forecast to become a hurricane within the
 next 24 hours. The official intensity forecast follows the upward
 trend of the consensus models FSSE and HCCA, but is a little lower
 and closer to the IVCN intensity consensus model.
 
 The forecast tropical-storm-force wind radii in the new official
 forecast has been expanded to the northeast based on recent ASCAT
 wind data. Although the core of strongest winds are forecast to
 remain offshore of the coast of southwestern Mexico, only a slight
 deviation to the right of track and/or strong localized funneling
 effects would bring hurricane-force winds onshore. As a result,
 the government of Mexico has issued a Hurricane Watch from Punta
 San Telmo to Playa Perula.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  06/0900Z 15.2N 100.3W   55 KT  65 MPH
  12H  06/1800Z 16.5N 102.3W   60 KT  70 MPH
  24H  07/0600Z 18.5N 105.1W   65 KT  75 MPH
  36H  07/1800Z 20.3N 107.8W   65 KT  75 MPH
  48H  08/0600Z 21.6N 110.2W   50 KT  60 MPH
  72H  09/0600Z...DISSIPATED
 
 $$
 Forecaster Stewart
 
 
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