WTPZ41 KNHC 132038 RRA

TCDEP1



HURRICANE FERNANDA DISCUSSION NUMBER   8

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP062017

200 PM PDT THU JUL 13 2017



FERNANDA IS RAPIDLY INTENSIFYING.  SATELLITE IMAGERY INDICATES THAT

THE CENTRAL CONVECTION HAS BECOME MORE SYMMETRIC, AND THERE HAVE

BEEN HINTS OF AN EYE IN VISIBLE IMAGERY.  IN ADDITION, EARLIER

MICROWAVE IMAGERY SHOWED AT LEASE A PARTIAL RING OF CONVECTION

AROUND THE CENTER.  SUBJECTIVE AND OBJECTIVE SATELLITE INTENSITY

ESTIMATES RANGE FROM 65-75 KT, SO THE INITIAL INTENSITY IS

INCREASED TO A POSSIBLY CONSERVATIVE 70 KT.  CONSERVATIVE OR NOT,

THIS IS A 35 KT INCREASE FROM THIS TIME YESTERDAY.



THE INITIAL MOTION IS A LITTLE SOUTH OF WEST OR 260/10, WITH PART

OF THE SOUTHWARD COMPONENT POSSIBLY DUE TO SOME REFORMATION OF THE

CENTER AS THE CYCLONE INTENSIFIED.  DURING THE NEXT 48 H, A

DEEP-LAYER RIDGE TO THE NORTH OF FERNANDA SHOULD STEER THE

HURRICANE GENERALLY WESTWARD, AND THE NEW FORECAST IS SIMILAR TO

THE PREVIOUS FORECAST.  AFTER THAT TIME, A LARGE MID- TO UPPER-LEVEL

TROUGH OVER THE CENTRAL PACIFIC NORTH OF HAWAII SHOULD CAUSE THE

RIDGE TO WEAKEN, AND THE TRACK GUIDANCE SHOWS FERNANDA TURNING

WEST-NORTHWESTWARD IN RESPONSE.  THE GUIDANCE IS FORECASTING A

GREATER NORTHWARD COMPONENT OF MOTION FROM 72-120 H THAN ON THE

PREVIOUS RUNS, AND THUS THE LATTER PART OF THE TRACK FORECAST IS

NUDGED NORTHWARD AS WELL.  OVERALL, THE NEW FORECAST LIES CLOSE TO

THE VARIOUS CONSENSUS MODELS.



WHILE SATELLITE IMAGERY SUGGESTS THAT SOME SHEAR CONTINUES TO

AFFECT FERNANDA, SO FAR IT HAS DONE LITTLE TO SLOW THE DEVELOPMENT.

THE HURRICANE SHOULD REMAIN OVER WARM WATER AND IN A LIGHT SHEAR