WTPZ41 KNHC 111440 RRA

TCDEP1



TROPICAL STORM ORLENE DISCUSSION NUMBER   3

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162016

800 AM PDT SUN SEP 11 2016



A CENTRAL DENSE OVERCAST HAS BECOME ESTABLISHED OVER ORLENE'S

CENTER, WITH VERY COLD TEMPERATURES OF -86C AT CLOUD TOP LEVEL.

THERE IS LITTLE TO NO DEEP-LAYER SHEAR, AND THE CYCLONE HAS VERY

GOOD UPPER-LEVEL OUTFLOW, ESPECIALLY TO THE NORTH AND WEST.

BECAUSE THE DVORAK RULES DON'T YET ALLOW THE USE OF AN EMBEDDED

CENTER PATTERN, ESTIMATES FROM TAFB AND SAB ARE STILL AT T2.5.

HOWEVER, THE OBJECTIVE UW-CIMSS ADT IS HIGHER, AND GIVEN THE MORE

CONSOLIDATED STRUCTURE COMPARED TO SIX HOURS AGO, THE INITIAL

INTENSITY IS RAISED TO 40 KT.



ORLENE IS MOVING NORTHWESTWARD, OR 305/12 KT, TO THE SOUTHWEST OF A

MID-TROPOSPHERIC HIGH LOCATED OVER NORTHERN MEXICO.  OVER THE NEXT

FEW DAYS, ORLENE IS EXPECTED TO BECOME TRAPPED IN AN ENVIRONMENT OF

WEAK STEERING TO THE WEST OF THE SUBTROPICAL RIDGE AXIS AND SOUTH

OF AN AMPLIFYING TROUGH OVER CALIFORNIA.  THIS SHOULD CAUSE THE

CYCLONE TO TURN NORTH-NORTHWESTWARD AND SLOW TO A CRAWL BY DAYS 2

AND 3.  AFTER THAT TIME, A RE-ESTABLISHMENT OF THE RIDGE SHOULD

FORCE AN ACCELERATION TOWARD THE WEST ON DAYS 4 AND 5.  THERE IS

NOT MUCH SPREAD AMONG THE TRACK MODELS DURING THE ENTIRE FORECAST

PERIOD.  EXCEPT FOR A SLIGHT NORTHEASTWARD SHIFT AT 36 AND 48

HOURS, THE UPDATED NHC FORECAST IS NEARLY IDENTICAL TO THE PREVIOUS

ONE AND LIES CLOSEST TO THE TVCX MULTI-MODEL CONSENSUS AND FLORIDA

STATE SUPERENSEMBLE.



LOW SHEAR AND WARM SEA SURFACE TEMPERATURES ARE EXPECTED TO SUPPORT

ADDITIONAL STRENGTHENING, AND THERE ARE SIGNS THAT RAPID=