relocated 50 miles from previous warning!
WDPN31 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W (PEIPAH)
WARNING NR 22//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 05W (PEIPAH), LOCATED APPROXIMATELY 670
NM EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTH-
NORTHWESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A SLOW CONSOLIDATION
OF DEEP CONVECTION AROUND A LOW LEVEL CIRCULATION CENTER (LLCC). A
MOSAIC OF RECENT MICROWAVE IMAGERY SUGGESTS THERE MAY BE ADDITIONAL
WEAK VORTICES ROTATING AROUND THE LLCC, WHICH MAY BE HAMPERING THE
LOW LEVEL DEVELOPMENT. THE INITIAL POSITION IS BASED ON A CENTROID
OF POSSIBLE CENTERS BASED ON THE AFOREMENTIONED MSI AND MICROWAVE
IMAGERY, AND REPRESENTS A RELOCATION OF APPROXIMATELY 50 NM FROM THE
PRIOR FORECAST POSITION. A 080605Z SSMIS 37 GHZ IMAGE THAT ARRIVED
LATE IN THE FORECAST GENERATION SUGGESTS THE LLCC MAY BE SLIGHTLY
SOUTHWESTARD OF THIS POSITION. UPPER LEVEL ANALYSIS REVEALS THE
EASTERLY VERTICAL WIND SHEAR (VWS) HAS SLIGHTLY IMPROVED (NOW 15-20
KNOTS), WITH STRONG DIFFLUENCE AND GOOD POLEWARD OUTFLOW STILL IN
PLACE. THE INITIAL INTENSITY IS ASSESSED AT 30 KNOTS BASED ON DVORAK
ESTIMATES FROM ALL FIXING AGENCIES, AS WELL AS RECENT ASCAT DATA.
TD 05W IS SITUATED WITHIN A WEAK STEERING ENVIRONMENT AND HAS
TRACKED ERRATICALLY OVER THE PAST 12 HOURS. THE CURRENT MOTION IS
PARTIALLY AN ARTIFACT OF THE POOR CERTAINTY OF THE INITIAL POSITION,
AND NOT ENTIRELY REPRESENTATIVE OF STORM MOTION.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 05W IS FORECAST TO REMAIN IN THE WEAK STEERING ENVIRONMENT
THROUGH TAU 48 BUT IS FORECAST TO TRACK SLOWLY NORTHWESTWARD TOWARD
THE WEAKNESS IN THE SUBTROPICAL RIDGE (STR). DYNAMIC GUIDANCE
VARIES WITH SOLUTIONS RANGING FROM NORTHWARD TO NORTHWESTWARD, AND
A LARGE SPREAD IN TRACK SPEEDS. SOME GUIDANCE SUGGESTS QUASI-
STATIONARY OR LOOPING MOTION OVER THE NEXT 48 HOURS. THE JTWC
FORECAST TRACK IS POSITIONED CLOSE TO THE MULTI-MODEL CONSENSUS AND
IS SLIGHTLY SLOWER THAN THE PREVIOUS FORECAST TAKING INTO ACCOUNT
THE SLOW TRACK SPEEDS INDICATED BY AN INCREASING NUMBER OF MODEL
SOLUTIONS. TD 05W SHOULD GRADUALLY INCREASE TO AN INTENSITY OF 40
KNOTS BY TAU 48 AS THE FOREWARD MOTION INCREASES AND THE SYSTEM
TRACKS INTO LOWER VWS.
C. IN THE EXTENDED TAUS, TD 05W IS EXPECTED TO TURN WEST-
NORTHWESTWARD AND ACCELERATE AS THE STR RE-BUILDS NORTH OF THE
SYSTEM. 05W SHOULD WEAKEN GRADUALLY AS IT TRACKS OVER THE
PHILIPPINES. DUE TO THE UNCERTAINTY IN THE INITIAL POSITION AS WELL
AS MAJOR TRACK AND TRACK SPEED DIFFERENCES BETWEEN THE DYNAMIC
MODELS, THERE IS LOW CONFIDENCE IN THE JTWC TRACK FORECAST.//
NNNN
ignore it or accept it! ...it's my prefered choice and we are a U.S territory and our local NWS office follows JT.
