Tropical Depression PENHA Advisory Bulletin (JTWC)
WTPN31 PGTW 061500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL DEPRESSION 02W (PENHA) WARNING NR 011//
RMKS/
1. TROPICAL DEPRESSION 02W (PENHA) WARNING NR 011
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
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WARNING POSITION:
061200Z --- NEAR 10.1N 122.8E
MOVEMENT PAST SIX HOURS - 285 DEGREES AT 08 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
REPEAT POSIT: 10.1N 122.8E
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FORECASTS:
12 HRS, VALID AT:
070000Z --- 10.8N 121.7E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 320 DEG/ 05 KTS
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24 HRS, VALID AT:
071200Z --- 11.6N 121.0E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
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REMARKS:
061500Z POSITION NEAR 10.3N 122.5E.
06FEB26. TROPICAL DEPRESSION 02W (PENHA), LOCATED APPROXIMATELY
290 NM SOUTH-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-
NORTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED
ENHANCED INFRARED SATELLITE IMAGERY (EIR) DEPICTS TD 02W
WITH AN INCREASINGLY DISORGANIZED AND BROAD LLCC AS THE SYSTEM
TRACKS NORTHWESTWARD ACROSS THE WESTERN PHILIPPINES. SUPPORTIVE
CONVECTION HAS CONTINUED TO QUICKLY DISSIPATE OVER THE LAST SIX
HOURS THROUGHOUT THE NORTHERN SEMICIRCLE DUE TO PERSISTENT
VWS BETWEEN 20-25 KTS, WHILE ENHANCED COOLER, NORTHERLY WINDS
FUNNEL INTO THE SULU SEA ALONG THE SYSTEMS WESTERN PERIPHERY,
ERODING THE SURFACE VORTEX. TD 02W IS FORECASTED TO CONTINUE
TRACKING TO THE NORTHWEST OVER THE NEXT 24 HOURS INTO DISSIPATION,
WHILE SURFACE INTENSITIES DECAY TOWARD 20 KTS. NORTH-NORTHEASTERLY
GRADIENT WINDS ASSOCIATED WITH A COLD SURGE EVENT WILL CONTINUE TO
LIMIT OPPORTUNITIES FOR RE-INTENSIFICATION THROUGH THE REMAINDER
OF THE FORECAST PERIOD. DUE TO THE WEAKENING SURFACE VORTEX,
JTWC CONSENSUS TRACK SOLUTIONS ILLUSTRATE A WIDENING CROSS-TRACK
SPREAD OVER THE NEXT 24 HOURS THROUGH DISSIPATION AS THE CIRCULATION
OPENS INTO A SURFACE TROUGH. JTWC INTENSITY SOLUTIONS ARE IN GOOD
AGREEMENT ON EXPECTED INTENSITIES, LENDING HIGH CONFIDENCE TO
THE JTWC INTENSITY FORECAST. THIS IS THE FINAL WARNING ON THIS SYSTEM
BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE
CLOSELY MONITORED FOR SIGNS OF REGENERATION. MINIMUM CENTRAL PRESSURE
AT 061200Z IS 1004 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 061200Z IS
12 FEET.//
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Tropical Depression PENHA Forecast Advisory (JTWC)
WDPN31 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 02W (PENHA) WARNING
NR 010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 9.9N 123.6E
INITIAL INTENSITY: 30 KTS
GEOGRAPHIC REFERENCE: 321 NM SOUTH-SOUTHEAST OF MANILA,
PHILIPPINES
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 12 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
DEPRESSION (TD) 02W (PENHA) WITH AN INCREASINGLY DISORGANIZED
LOW-LEVEL CIRCULATION CENTER (LLCC), OBSCURED BY FLARING CONVECTION
NEAR NEGROS AND PANAY. FRAGMENTED LOW-LEVEL CLOUD LINES HAVE BEEN
OBSERVED WRAPPING BENEATH THE PRIMARY CONVECTIVE STRUCTURES IN
CLOSE PROXIMITY TO THE LLCC OVER THE LAST FEW HOURS, HOWEVER,
PERSISTENT MODERATE VERTICAL WIND SHEAR (VWS) HAS BEGUN TILTING THE
VERTICAL STRUCTURE WESTWARD SINCE THE PREVIOUS WARNING. THE
ENVIRONMENT IS MARGINALLY UNFAVORABLE, WITH MODERATE VWS,
INTERMITTENT POCKETS OF COOLER SEA SURFACE TEMPERATURES NEAR 26 C,
AND SUPPORTIVE POLEWARD OUTFLOW ALOFT. THE INITIAL POSITION HAS BEEN
PLACED WITH LOW CONFIDENCE BASED ON ANIMATED MSI IMAGERY. THE INITIAL
INTENSITY HAS BEEN ASSESSED WITH MEDIUM CONFIDENCE BASED ON
SUBJECTIVE AGENCY DVORAK ESTIMATES BETWEEN 25-35 KTS.
INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).
CURRENT STEERING MECHANISM: THE SOUTHWEST EXTENT OF A SUBTROPICAL
RIDGE (STR) CENTERED TO THE EAST-NORTHEAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T1.5 - 25 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.5 - 35 KTS
CIMSS SATCON: 46 KTS AT 060512Z
CIMSS ADT: 53 KTS AT 060530Z
CIMSS AIDT: 44 KTS AT 060530Z
CIMSS D-MINT: 44 KTS AT 060512Z
CIMSS D-PRINT: 44 KTS AT 060710Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
VWS: 20-25 KTS
SST: 27-28 CELSIUS
OUTFLOW: MODERATE POLEWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: LOW
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: NOT APPLICABLE
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TD 02W IS FORECASTED TO CONTINUE TRACKING TO
THE NORTHWEST THROUGHOUT THE 24-HOUR PERIOD, ALONG THE SOUTHWESTERN
EXTENT OF THE STR POSITIONED TO THE EAST-NORTHWEST UNTIL
DISSIPATION OVER WATER. REGARDING INTENSITY, TD PENHA IS FORECASTED
TO CONTINUE GRADUALLY WEAKENING OVER THE NEXT 24 HOURS, DUE TO
SUSTAINED MODERATE VERTICAL WIND SHEAR ABOVE 15 KTS, PERSISTENT
COOLER SEA SURFACE TEMPERATURES NEAR 26 C WITHIN THE NORTHERN SULU
SEA, AND INCREASING DRY-AIR ENTRAINMENT FROM THE SOUTHEAST. IN
ADDITION, TD 02W WILL CONTINUE TO DECAY AS AN INCREASING NORTHEAST
SURGE INTO THE EAST CHINA SEA AND SULU SEA SHALLOW THE SYSTEM NEAR
THE SURFACE, FILLING THE SURFACE CLOSED LOW INTO AN OPEN TROUGH BY
TAU 24.
MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE AND ARTIFICIAL
INTELLIGENCE (AI) MODEL GUIDANCE REMAINS IN FAIRLY GOOD AGREEMENT
THROUGH THE FORECAST PERIOD, WITH AN EXPECTED NORTHWEST TRACK AND A
56 NM CROSS-TRACK SPREAD. THE PROBABILISTIC ECMWF SOLUTION REMAINS
AS THE ONLY OUTLIER, WITH A NORTHWARD TRACK AT TAU 12 UNTIL
DISSIPATION. THE JTWC TRACK FORECAST HAS BEEN PLACED WITH MEDIUM
CONFIDENCE, AND ALIGNED CLOSELY TO THE JTWC MULTI-MODEL CONSENSUS.
REGARDING INTENSITY, ALL JTWC INTENSITY CONSENSUS MEMBERS ILLUSTRATE
STEADY TO WEAKENING INTENSITIES OVER THE NEXT 24 HOURS, WITH GFS
BEING THE MOST AGGRESSIVE DURING THE TERMINAL WEAKENING PHASE. THE
JTWC INTENSITY FORECAST HAS BEEN PLACED CLOSE TO THE MULTI-MODEL
INTENSITY CONSENSUS UNTIL TAU 12, THEN NEAR HAFS-A AND GFS
THEREAFTER UNTIL DISSIPATION DUE TO THE INCREASINGLY HOSTILE
ENVIRONMENT IN THE SULU SEA, LENDING MEDIUM CONFIDENCE TO THE
INTENSITY FORECAST.
FORECAST CONFIDENCE:
TRACK 00-72 HR: MEDIUM
INTENSITY 00-72 HR: MEDIUM//
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