WTPZ43 KNHC 240256 RRA

TCDEP3



TROPICAL STORM PILAR DISCUSSION NUMBER   2

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP182017

1000 PM CDT SAT SEP 23 2017



THE STRUCTURE OF THE CYCLONE NEAR MEXICO HAS IMPROVED OVER THE PAST

6 HOURS.  DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB NOW SUPPORT

AN ESTIMATED INTENSITY OF 35 KT, SO THE SYSTEM IS NOW CLASSIFIED AS

TROPICAL STORM PILAR.



THE INITIAL MOTION BASED ON RECENT SATELLITE FIXES IS 350/4 KT.

PILAR IS STILL EXPECTED TO MOVE GENERALLY TOWARD THE NORTH-NORTHWEST

OR NORTH TO THE EAST OF A MID-LEVEL RIDGE CENTERED OVER MEXICO FOR

THE NEXT COUPLE OF DAYS, AND THE PRIMARY SOURCE OF UNCERTAINTY IN

THE FORECAST IS POSSIBLE INTERACTION WITH LAND.  DUE IN PART TO

INITIAL POSITION UNCERTAINTY, THE GLOBAL MODELS VARY ON WHETHER

PILAR WILL CLIP THE COAST OF JALISCO OR REMAIN JUST OFFSHORE, BUT

THE MODEL CONSENSUS NOW SHOWS A LANDFALL IN ABOUT 24 HOURS.  THE

NHC FORECAST HAS BEEN ADJUSTED SLIGHTLY TO THE EAST TOWARD THE

MODEL CONSENSUS, BUT IT IS CERTAINLY POSSIBLE THAT THE TROPICAL

STORM COULD REMAIN OFFSHORE AND ENTER THE GULF OF CALIFORNIA.

REGARDLESS OF WHETHER THE CENTER MAKES LANDFALL OR NOT, HEAVY RAIN

IS STILL LIKELY ALONG THE COAST OF MEXICO THROUGH EARLY NEXT WEEK.



THE POSSIBILITY OF LAND INTERACTION MAKES THE INTENSITY FORECAST

PARTICULARLY DIFFICULT.  VERY WARM SSTS AND ONLY MODERATE SHEAR

SHOULD ALLOW FOR SOME STRENGTHENING FOR AT LEAST THE NEXT 36 HOURS.

HOWEVER, IF PILAR MAKES LANDFALL SOONER THAN THAT, IT WILL LIKELY

QUICKLY WEAKEN.  SINCE MY TRACK FORECAST SHOWS PILAR MAKING

LANDFALL IN ABOUT 24 HOURS, MY INTENSITY FORECAST PEAKS AT THAT

TIME, AND SHOWS STEADY WEAKENING THEREAFTER.  BEGINNING AROUND 48