Tropical Storm JEBI Advisory Bulletin (JTWC)
WTPN32 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL STORM 19W (JEBI) WARNING NR 024//
RMKS/
1. TROPICAL STORM 19W (JEBI) WARNING NR 024
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
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WARNING POSITION:
020600Z --- NEAR 44.9N 152.5E
MOVEMENT PAST SIX HOURS - 045 DEGREES AT 41 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
095 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
REPEAT POSIT: 44.9N 152.5E
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FORECASTS:
12 HRS, VALID AT:
021800Z --- 50.9N 161.1E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 060 DEG/ 32 KTS
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24 HRS, VALID AT:
030600Z --- 53.7N 170.5E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
220 NM SOUTHEAST QUADRANT
200 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
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REMARKS:
020900Z POSITION NEAR 46.4N 154.7E.
02OCT24. TROPICAL STORM 19W (JEBI), LOCATED APPROXIMATELY 566 NM
EAST-NORTHEAST OF MISAWA, JAPAN, HAS TRACKED NORTHEASTWARD AT 41
KNOTS OVER THE PAST SIX HOURS. TS JEBI IS CURRENTLY UNDERGOING
EXTRATROPICAL TRANSITION THROUGH ITS NORTHEASTWARD TRACK INTO THE
MID-LATITUDE BAROCLINIC ZONE AS SEA SURFACE TEMPERATURES HAVE
DECREASED TO WELL BELOW 24 C AND VERTICAL WIND SHEAR (VWS) HAS
INCREASED TO ABOVE 25 KNOTS. THE SYSTEM IS EXPECTED TO COMPLETE
EXTRATROPICAL TRANSITION DURING THE NEXT SIX TO TWELVE HOURS AS AN
EASTWARD PROGRESSING LONGWAVE TROUGH WILL PROVIDE TRANSITION SUPPORT
INTO AN ASYMMETRIC COLD-CORE MID-LATITUDE LOW. ANIMATED VISIBLE
IMAGERY AND A 89 GHZ 020300Z AMSR2 MICROWAVE IMAGE SUPPORT THE
EXTRATROPICAL TRANSITION ASSESSMENT AS CONVECTION ASSOCIATED WITH 19W
HAS BECOME POLEWARD AND EASTWARD OF THE LOW-LEVEL CIRUCATION CENTER,
AND THE SYSTEMS VERTICAL STRUCTURE CONTINUES TO BECOME INCREASINGLY
TILTED WITH HEIGHT. 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
020600Z IS 978 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 020600Z IS 24
FEET. REFER TO TYPHOON 20W (KRATHON) WARNINGS (WTPN33 PGTW) FOR SIX-
HOURLY UPDATES.//
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Tropical Storm JEBI Forecast Advisory (JTWC)
WDPN32 PGTW 020300 COR
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (JEBI) WARNING NR
023A CORRECTED//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 41.7N 148.5E
INITIAL INTENSITY: 60 KTS
GEOGRAPHIC REFERENCE: 339 NM EAST-NORTHEAST OF MISAWA, JAPAN
MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 36 KTS
SIGNIFICANT WAVE HEIGHT: 27 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN
INCREASINGLY ASYMMETRIC CONVECTIVE CORE, NOW PRIMARILY NORTH AND
EAST OF THE LLCC AS SOUTHWESTERLY VERTICAL SHEAR INCREASES, BUT A
COMPACT WIND FIELD AND WARM-CORE STRUCTURE REMAIN INTACT. THE
CYCLONE THUS CONTINUES TO BE ASSESSED AS TROPICAL. CLOUD TOPS ARE
WARMING AS THE CYCLONE TRACKS OVER PROGRESSIVELY COLDER WATERS. THE
INITIAL INTENSITY IS SET AT 60 KT BASED ON A BLEND OF AGENCY DVORAK
AND OBJECTIVE SATELLITE-BASED INTENSITY ESTIMATES. AN EARLIER
012034Z SMAP PASS REVEALED THAT THE CYCLONE STILL HAD TYPHOON-FORCE
WINDS AT THAT TIME, BUT SOME WEAKENING IS PRESUMED TO HAVE OCCURRED
SINCE, AS THE STORM HAS BEEN MOVING OVER PROHIBITIVELY COLD WATERS.
INITIAL WIND RADII BASIS: SMAP DATA
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTHEAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.5 - 77 KTS
RJTD: T4.0 - 65 KTS
RCTP: T4.5 - 77 KTS
KNES: T4.5 - 77 KTS
CIMSS SATCON: 69 KTS AT 012227Z
CIMSS ADT: 104 KTS AT 012330Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
VWS: 20-25 KTS
SST: 16-18 CELSIUS
OUTFLOW: WEAK EASTWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: MEDIUM
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TROPICAL STORM 19W (JEBI) IS ACCELERATING
NORTHEASTWARD INTO THE MID-LATITUDE WESTERLIES AND IS NOW OVER COLD
WATERS NORTH OF THE KUROSHIO CURRENT. EXTRATROPICAL TRANSITION IS
EXPECTED TO BEGIN IMMINENTLY, COMPLETING IN 12-24 HOURS, AND STEADY
WEAKENING IS EXPECTED DURING THAT PERIOD. HOWEVER, MAX WINDS MAY
REMAIN AT OR ABOVE GALE FORCE BY THE TIME EXTRATROPICAL TRANSITION
OCCURS. DYNAMICAL MODELS ARE IN GOOD AGREEMENT THAT JEBI WILL
CONTINUE NORTHEASTWARD TO A POSITION EAST OF THE KAMCHATKA PENINSULA
IN 24 HOURS, BECOMING EMBEDDED WITHIN THE EASTERN FLANK OF A
BAROCLINIC LOW DEVELOPING WEST OF THE KAMCHATKA PENINSULA AT THAT
TIME.
MODEL DISCUSSION: THE JTWC TRACK FORECAST IS CLOSE TO THE
MULTI-MODEL CONSENSUS. THE JTWC INTENSITY FORECAST IS SLIGHTLY
ABOVE THE MULTI-MODEL CONSENSUS DUE TO THE STRENGTH OF THE
EXTRATROPICAL WIND FIELD EXPECTED BY GLOBAL MODELS.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: HIGH
INTENSITY 0 - 72 HR: HIGH
4. JUSTIFICATION FOR CORRECTION: CORRECTED DVORAK FIXES TO VALID
TIME.//
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