Eastern Pacific Basin Tropical Cyclones

Tropical Storm Orlene Forecast Discussion


000
WTPZ41 KNHC 300834
TCDEP1

Tropical Storm Orlene Discussion Number   6
NWS National Hurricane Center Miami FL       EP162022
300 AM MDT Fri Sep 30 2022

Orlene continues to gain strength.  An earlier microwave overpass 
revealed a well-defined curved band wrapping into a developing inner 
core.  Persistent deep convection is over the estimated low-level 
center location, with cloud tops near -80 degrees Celsius. The 
UW-CIMSS ADT objective Dvorak estimate as well as the Data-T number 
from SAB have increased from the previous advisory, and therefore 
the initial intensity has been nudged up to 50 kt.  

The storm has turned northwestward and is heading 320/4 kt as it 
begins to slowly round the western periphery of a mid-level ridge 
located over Mexico.  A turn to the north should occur by tonight 
followed by a turn to the north-northeast along with a slight 
increase in forward speed, as Orlene rounds the ridge and gets 
caught in the flow between the ridge and an upper trough to its 
west.  The consensus track guidance has shifted slightly eastward 
this cycle, partially due to the ECMWF track coming into better 
agreement with the rest of the global models.  The NHC track 
forecast was also adjusted a little to the right, but remains just 
west of the consensus. Based on the trends in the track forecast, 
there is an increasing probability that Orlene may affect the coast 
of the Mexican state of Jalisco as it passes just to the west of 
that location in 2-3 days. Therefore, watches may be required for a 
portion of that coastline later this morning. 

Orlene is within an environment favorable for strengthening, with 
plenty of atmospheric moisture, low vertical wind shear, and water 
temperatures of 29 degrees C.  The cyclone's forecast path should 
keep it within these conditions for the next 36-48 h.  With there 
now being evidence of an inner core, Orlene's rate of strengthening 
should increase soon.  After 48 h, strong southwesterly shear is 
forecast to begin impacting the cyclone and should entrain dry 
mid-tropospheric air into its circulation.  This should cause 
Orlene to weaken before it reaches the coast of Mexico early next 
week.  Based on the small size of the cyclone, fairly rapid changes 
in its intensity are possible, both while strengthening and 
weakening.  The NHC forecast is a little higher that the previous 
one and is very near the various multi-model consensus solutions.


FORECAST POSITIONS AND MAX WINDS

INIT  30/0900Z 15.9N 106.9W   50 KT  60 MPH
 12H  30/1800Z 16.6N 107.2W   60 KT  70 MPH
 24H  01/0600Z 17.4N 107.4W   70 KT  80 MPH
 36H  01/1800Z 18.2N 107.3W   80 KT  90 MPH
 48H  02/0600Z 19.3N 107.1W   90 KT 105 MPH
 60H  02/1800Z 20.5N 106.8W   80 KT  90 MPH
 72H  03/0600Z 21.8N 106.6W   60 KT  70 MPH
 96H  04/0600Z 23.8N 106.3W   35 KT  40 MPH...INLAND
120H  05/0600Z...DISSIPATED

$$
Forecaster Latto



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