Météo974
WESTERN NORTH PACIFIC
Location: 15.1°N 159.2°E
Maximum Winds: 30 kt ( 55km/h)
Gusts: 40 kt ( 75km/h)
Minimum Central Pressure: 1003 mb
WDPN31 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 20W (TWENTY) WARNING
NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 20W (TWENTY), LOCATED APPROXIMATELY 835
NM EAST OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 18 KNOTS KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY SHOWS THE SYSTEM CONTINUED TO CONSOLIDATE WITH FORMATIVE
BANDS, MOSTLY
FROM THE SOUTH, WRAPPING INTO AN OBSCURED LOW LEVEL CIRCULATION
(LLC). THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON
THE EIR LOOP AND LINED UP WITH A RAGGED BUT DISCERNIBLE LLC FEATURE
IN THE
0500802Z SSMIS 37GHZ COLORIZED IMAGE. THE INITIAL INTENSITY OF 30KTS
IS BASED ON THE DVORAK ESTIMATE OF T2.0/30KTS FROM PGTW AND
CONSISTENT WITH THE EIR SATELLITE SIGNATURE. UPPER LEVEL ANALYSIS
INDICATES THE SYSTEM IS IN AN AREA OF LIGHT (05-10KT) NORTHEASTERLY
VERTICAL WIND SHEAR AND EXCELLENT RADIAL OUTFLOW WITH A ROBUST
EQUATORWARD BIAS. ADDITIONALLY, ALONG-TRACK SSTS ARE HIGHLY CONDUCIVE
AT 30C. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A
DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TD 20W WILL CONTINUE TRACKING WESTWARD THEN, AFTER TAU 48,
WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR. THE
AFOREMENTIONED FAVORABLE CONDITIONS WILL PERSIST AND PROMOTE STEADY
INTENSIFICATION, REACHING 105KTS BY TAU 72.
B. AFTER TAU 72, TD 20W WILL TRACK MORE NORTHWESTWARD AS THE STR
WEAKENS IN RESPONSE TO A MIDLATITUDE TROUGH APPROACHING FROM THE
KOREAN PENINSULA. THE INCREASED POLEWARD OUTFLOW AHEAD OF THE TROUGH, IN
ADDITION TO THE SUSTAINED FAVORABLE ENVIRONMENTAL CONDITIONS, WILL
INITIATE RAPID INTENSIFICATION POTENTIALLY REACHING SUPER TYPHOON
INTENSITY OF 130KTS BY TAU 96. NUMERICAL MODELS ARE IN GOOD AGREEMENT
WITH A GRADUAL SPREAD TO 300NM BY END OF FORECAST. HOWEVER, IN VIEW
OF THE FORMATIVE NATURE OF THE SYSTEM AND THE UNCERTAINTY IN THE
INITIAL STORM TRACK, THERE IS OVERALL LOW CONFIDENCE IN THE JTWC
TRACK FORECAST.//
NNNN
M974World
WESTERN NORTH PACIFIC
Location: 15.1°N 159.2°E
Maximum Winds: 30 kt ( 55km/h)
Gusts: 40 kt ( 75km/h)
Minimum Central Pressure: 1003 mb
WDPN31 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 20W (TWENTY) WARNING
NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 20W (TWENTY), LOCATED APPROXIMATELY 835
NM EAST OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 18 KNOTS KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY SHOWS THE SYSTEM CONTINUED TO CONSOLIDATE WITH FORMATIVE
BANDS, MOSTLY
FROM THE SOUTH, WRAPPING INTO AN OBSCURED LOW LEVEL CIRCULATION
(LLC). THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON
THE EIR LOOP AND LINED UP WITH A RAGGED BUT DISCERNIBLE LLC FEATURE
IN THE
0500802Z SSMIS 37GHZ COLORIZED IMAGE. THE INITIAL INTENSITY OF 30KTS
IS BASED ON THE DVORAK ESTIMATE OF T2.0/30KTS FROM PGTW AND
CONSISTENT WITH THE EIR SATELLITE SIGNATURE. UPPER LEVEL ANALYSIS
INDICATES THE SYSTEM IS IN AN AREA OF LIGHT (05-10KT) NORTHEASTERLY
VERTICAL WIND SHEAR AND EXCELLENT RADIAL OUTFLOW WITH A ROBUST
EQUATORWARD BIAS. ADDITIONALLY, ALONG-TRACK SSTS ARE HIGHLY CONDUCIVE
AT 30C. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A
DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TD 20W WILL CONTINUE TRACKING WESTWARD THEN, AFTER TAU 48,
WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR. THE
AFOREMENTIONED FAVORABLE CONDITIONS WILL PERSIST AND PROMOTE STEADY
INTENSIFICATION, REACHING 105KTS BY TAU 72.
B. AFTER TAU 72, TD 20W WILL TRACK MORE NORTHWESTWARD AS THE STR
WEAKENS IN RESPONSE TO A MIDLATITUDE TROUGH APPROACHING FROM THE
KOREAN PENINSULA. THE INCREASED POLEWARD OUTFLOW AHEAD OF THE TROUGH, IN
ADDITION TO THE SUSTAINED FAVORABLE ENVIRONMENTAL CONDITIONS, WILL
INITIATE RAPID INTENSIFICATION POTENTIALLY REACHING SUPER TYPHOON
INTENSITY OF 130KTS BY TAU 96. NUMERICAL MODELS ARE IN GOOD AGREEMENT
WITH A GRADUAL SPREAD TO 300NM BY END OF FORECAST. HOWEVER, IN VIEW
OF THE FORMATIVE NATURE OF THE SYSTEM AND THE UNCERTAINTY IN THE
INITIAL STORM TRACK, THERE IS OVERALL LOW CONFIDENCE IN THE JTWC
TRACK FORECAST.//
NNNN