

WDPN35 PGTW 190900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 22W (SOULIK) WARNING NR 16//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON 22W (SOULIK), LOCATED APPROXIMATELY 142 NM WEST OF IWO
TO, HAS TRACKED WEST-SOUTHWESTWARD AT 04 KNOTS OVER THE PAST SIX
HOURS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON
AN APPROXIMATELY 25 NM WIDE EYE IN MULTISPECTRAL SATELLITE IMAGERY
AND A 190527Z SSMI 37 GHZ IMAGE WHICH DEPICTS A MICROWAVE EYE
FEATURE. ENHANCED INFRARED SATELLITE IMAGERY SHOWS SOME DEEP
CONVECTION BUILDING ON THE NORTHERN SIDE OF THE CYCLONE AND LESS
DEEP CONVECTION ELSEWHERE. THE CURRENT INTENSITY IS ASSESSED AT 100
KNOTS BASED ON DVORAK CURRENT INTENSITY ESTIMATES OF T5.0-T6.0 (90-
115 KTS) AND A 190036Z SATCON ESTIMATE OF 94 KTS. LOW VERTICAL WIND
SHEAR, GOOD RADIAL OUTFLOW, AND WARM SEA SURFACE TEMPERATURE (29-30
CELSIUS) ARE BEING OFFSET BY SUBSIDING, DRY AIR WRAPPING IN FROM THE
WEST THAT IS INHIBITING INTENSIFICATION. TY 22W IS BEING STEERED BY
A BUILDING SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. THE STR TO THE NORTH IS GRADUALLY BUILDING. AS IT DOES, THE
TRACK WILL BECOME WEST-NORTHWESTWARD AND ACCELERATE TO AROUND 10 KTS
THROUGH TAU 48. AFTER TAU 48, TY 22W WILL BEGIN TRACKING MORE
NORTHWESTWARD AS IT BEGINS TO ROUND THE WESTERN PERIPHERY OF THE
STR. THE INTENSITY IS EXPECTED TO DECREASE TO 95 KTS BEFORE
IMPROVING ENVIRONMENTAL CONDITIONS WILL ALLOW SLIGHT
INTENSIFICATION, REACHING 100 KTS BY TAU 36. THE INTENSITY FORECAST
CLOSELY FOLLOWS THE HWRF AND THE INTENSITY GUIDANCE CONSENSUS. THE
JTWC FORECAST TRACK CLOSELY FOLLOWS THE MULTI-MODEL CONSENSUS. THE
SPREAD AMONG THE MEMBERS IS LESS THAN 100 NM THROUGH TAU 48 BUT
INCREASES SIGNIFICANTLY AFTERWARD DUE TO DIFFERENCES IN THE
ORIENTATION AND STRENGTH OF THE STR AMONG THE MODELS. THROUGH TAU
72, CONFIDENCE IN THE JTWC FORECAST TRACK IS LOW, PRIMARILY DUE TO
INCREASING UNCERTAINTY BEYOND TAU 48.
C. BY TAU 96, 22W WILL ROUND THE STR AXIS, TRACK NORTHEASTWARD,
AND BEGIN EXTRATROPICAL TRANSITION AS IT GETS EMBEDDED IN THE MID-
LATITUDE WESTERLIES. TRACK UNCERTAINTY REMAINS HIGH FOR THIS PERIOD
BUT THE TRACK GUIDANCE IS MORE CONSISTENT BETWEEN MODEL RUNS AND THE
JTWC FORECAST TRACK IS VERY SIMILAR TO THE PREVIOUS FORECAST. THE
CYCLONE IS EXPECTED TO WEAKEN SIGNIFICANTLY FOR THIS PORTION OF THE
FORECAST DUE TO INCREASING VWS AND LAND INTERACTION, HOWEVER, THERE
IS HIGH UNCERTAINTY IN HOW RAPIDLY IT WILL WEAKEN BECAUSE MINOR
SHIFTS IN THE TRACK CAN CAUSE MAJOR DIFFERENCES IN THE AMOUNT OF
LAND INTERACTION. CONFIDENCE IN THE FORECAST TRACK REMAINS LOW DUE
TO HIGH UNCERTAINTY IN THE LOCATION AND TIMING OF THE RECURVE.//
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