Météo974
WESTERN NORTH PACIFIC
TS FRANCISCO (09W)
Location: 29.1°N 139.7°E
Maximum Winds: 45 kt ( 85km/h)
Gusts: 55 kt ( 100km/h)
Minimum Central Pressure: 991 mb
WDPN32 PGTW 041500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (FRANCISCO) WARNING
NR 12//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 09W (FRANCISCO), LOCATED APPROXIMATELY 567 NM EAST-
SOUTHEAST OF SASEBO, JAPAN, HAS TRACKED WEST-NORTHWESTWARD AT 19
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY REVEALS A LOW LEVEL CIRCULATION CENTER (LLCC) WITH
RELATIVELY DRY AIR WRAPPING IN FROM THE SOUTHEAST, HAMPERING
CONVECTION. THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION BASED
ON A 041113Z METOP-B 89 GHZ MICROWAVE IMAGE THAT SHOWS SHALLOW
CONVECTIVE BANDING WRAPPING INTO THE LLCC. THE INITIAL INTENSITY OF
45 KNOTS FALLS BETWEEN MULTI-AGENCY DVORAK FIXES FROM T2.5-T3.0 (35-
45 KNOTS) AND A 040827Z SATCON ESTIMATE OF 53 KNOTS. A PARTIAL
041114Z METOP-B ASCAT PASS CONFIRMS THIS INTENSITY ESTIMATE AND
DISPLAYS AN ASYMMETRIC WIND FIELD WITH THE STRONGEST WINDS CONTAINED
IN THE NORTHEAST QUADRANT. THE ENVIRONMENT IS MARGINALLY FAVORABLE
WITH LOW (05-10 KNOTS) VERTICAL WIND SHEAR (VWS) AND WARM (28-29
CELSIUS) SEA SURFACE TEMPERATURE (SST) BEING OFFSET BY FAIR POLEWARD
OUTFLOW AND DRY AIR ENTRAINMENT FROM AN AREA OF UPPER-LEVEL
CONVERGENCE TO THE SOUTH. TS 09W IS TRACKING ALONG THE SOUTHWEST
PERIPHERY OF A SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE OVERALL FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. THROUGH TAU 48, TS 09W IS FORECAST TO TRACK GENERALLY
NORTHWESTWARD TOWARD SASEBO UNDER THE STEERING INFLUENCE OF THE
AFOREMENTIONED STR. MODEL GUIDANCE IS IN GOOD AGREEMENT FOR THIS
PORTION OF THE FORECAST WITH THE SPREAD AT 48 HOURS AT APPROXIMATELY
55 NM. AFTER PASSING SASEBO AROUND TAU 48, TS 09W IS EXPECTED TO
BEGIN A GRADUAL POLEWARD TURN AS IT ROUNDS THE STR AXIS. UNTIL
LANDFALL IN JAPAN AROUND TAU 30, TS 09W IS EXPECTED TO SLOWLY
INTENSIFY TO AROUND 50 KNOTS AS THE ENVIRONMENT REMAINS MARGINAL DUE
TO POOR UPPER LEVEL DIVERGENCE AND THE EFFECTS OF DRY AIR
ENTRAINMENT. THE RUGGED TERRAIN OF KYUSHU WILL HAMPER ANY
INTENSIFICATION OF TS 09W AFTER LANDFALL. A SECOND LANDFALL SHOULD
OCCUR NEAR BUSAN, KOREA AROUND TAU 48. BASED ON TIGHT GROUPING OF
THE MODEL DATA AND THE STEADY INFLUENCE OF THE STR, THERE IS HIGH
CONFIDENCE IN THIS PORTION OF THE JTWC TRACK FORECAST.
C. AFTER TAU 72, TS 09W WILL CONTINUE RECURVING AS IT ROUNDS THE
STR AXIS, PASSING INTO THE SEA OF JAPAN. THROUGHOUT THIS PERIOD,
LAND INTERACTION, INCREASING VWS, AND COOLER SST SHOULD WEAKEN THE
SYSTEM. BY TAU 72, TS 09W WILL BEGIN INTERACTING WITH THE MID-
LATITUDE BAROCLINIC ZONE AND START UNDERGOING EXTRATROPICAL
TRANSITION (ETT). ETT SHOULD COMPLETE PRIOR TO TAU 120. AS THE SYSTEM
ROUNDS THE STR AXIS, SPREAD IN MODEL GUIDANCE INCREASES
SIGNIFICANTLY, PRIMARILY DUE TO DIFFERENCES IN ALONG-TRACK SPEED. FOR
THIS REASON, THERE IS LOW CONFIDENCE IN THE EXTENDED PORTION OF THE
JTWC TRACK FORECAST.//
NNNN
Location: 17.6°N 131.4°E
Maximum Winds: 30 kt ( 55km/h)
Gusts: 40 kt ( 75km/h)
Minimum Central Pressure: 997 mb
WDPN31 PGTW 041500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 10W (TEN) WARNING
NR 03//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 10W (LEKIMA), LOCATED APPROXIMATELY 570 NM
SOUTH-SOUTHEAST OF KADENA AB, HAS TRACKED NORTHWARD AT 11 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
(EIR) REVEALS AN AREA EMBEDDED IN A BROAD CIRCULATION WHERE
SUSTAINED CONVECTION IN THE WESTERN SEMICIRCLE APPEARS TO BE CAUSING
CONSOLIDATION. THERE IS MODERATE CONFIDENCE IN THE INITIAL POSITION,
PLACED WITHIN THE APPARENT SHALLOW BANDING SEEN IN A 041004Z SSMIS
91 GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY OF 30 KTS IS BASED ON
MULTIPLE AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T1.5-2.0 (25-
35 KTS). A 041251Z METOP-B ASCAT PASS CONFIRMS THE POSITION AND
INTENSITY ESTIMATE, SHOWING A CIRCULATION WITH A LARGE AREA OF
APPROXIMATELY 35-45 KT WESTERLY WINDS OVER 100 NM TO THE SOUTH OF
THE CURRENT POSITION. THE ENVIRONMENT IS FAVORABLE WITH GOOD
EQUATORWARD AND POLEWARD OUTFLOW, WARM (29-30 CELSIUS) SEA SURFACE
TEMPERATURE AND LOW (10-15 KT) VERTICAL WIND SHEAR (VWS). TD 10W IS
DRIFTING GENERALLY POLEWARD UNDER WEAK STEERING INFLUENCE FROM A
SUBTROPICAL RIDGE (STR) TO THE WEST OF TD 10W.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE OVERALL FORECAST PHILOSOPHY SINCE
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. THROUGH TAU 48, TD 10W IS EXPECTED TO DRIFT SLOWLY POLEWARD
ALONG THE EASTERN EXTENSION OF THE STR. BETWEEN TAU 48 AND 72, THE
STR EXTENSION TO THE NORTH WILL TAKE OVER AS THE PRIMARY STEERING
INFLUENCE AND THE TRACK SHOULD SHIFT MORE NORTHWESTWARD. TD 10W IS
EXPECTED TO INTENSIFY STEADILY, REACHING 55 KTS BY TAU 72. MOST OF
THE UNCERTAINTY IN THE MODEL GUIDANCE FOR THIS PORTION OF THE
FORECAST IS IN THE EARLY TAUS AS THE MODEL TRACKERS ARE LIKELY
HAVING DIFFICULTY IDENTIFYING THE LLCC IN THE BROADER CIRCULATION.
OVERALL, THERE IS VERY LOW CONFIDENCE IN THE EARLY PORTION OF THE
FORECAST WITH A 350 NM SPREAD AT TAU 72, LARGELY OWING TO HIGH
UNCERTAINTY IN THE INITIAL POSITION AND SUBSEQUENT UNCERTAINTY IN
THE MODEL TRACK GUIDANCE.
C. BEYOND TAU 72, TD 10W IS EXPECTED TO CONTINUE ON A
NORTHWESTWARD TRACK ALONG THE SOUTHWEST PERIPHERY OF THE STR AND TO
INCREASE STEADILY INTENSITY TO 90 KTS BY TAU 120. INTENSITY GUIDANCE
IS IN FAIR AGREEMENT DUE TO A FAVORABLE ENVIRONMENT THROUGHOUT THE
FORECAST PERIOD WITH LIMITED DEVIATION THROUGH TAU 120; HOWEVER, THE
INTENSITY UNCERTAINTY IS HIGHLY SENSITIVE TO THE HIGH TRACK
UNCERTAINTY. TRACK GUIDANCE, IS IN POOR AGREEMENT WITH A SPREAD OF
NEARLY 1000NM BETWEEN GFS AND NAVGEM AT TAU 120, LIKELY IN PART TO
THE HIGH UNCERTAINTY IN THE INITIAL
POSITION.//
NNNN
M974World
WESTERN NORTH PACIFIC
TS FRANCISCO (09W)
Location: 29.1°N 139.7°E
Maximum Winds: 45 kt ( 85km/h)
Gusts: 55 kt ( 100km/h)
Minimum Central Pressure: 991 mb
WDPN32 PGTW 041500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (FRANCISCO) WARNING
NR 12//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 09W (FRANCISCO), LOCATED APPROXIMATELY 567 NM EAST-
SOUTHEAST OF SASEBO, JAPAN, HAS TRACKED WEST-NORTHWESTWARD AT 19
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY REVEALS A LOW LEVEL CIRCULATION CENTER (LLCC) WITH
RELATIVELY DRY AIR WRAPPING IN FROM THE SOUTHEAST, HAMPERING
CONVECTION. THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION BASED
ON A 041113Z METOP-B 89 GHZ MICROWAVE IMAGE THAT SHOWS SHALLOW
CONVECTIVE BANDING WRAPPING INTO THE LLCC. THE INITIAL INTENSITY OF
45 KNOTS FALLS BETWEEN MULTI-AGENCY DVORAK FIXES FROM T2.5-T3.0 (35-
45 KNOTS) AND A 040827Z SATCON ESTIMATE OF 53 KNOTS. A PARTIAL
041114Z METOP-B ASCAT PASS CONFIRMS THIS INTENSITY ESTIMATE AND
DISPLAYS AN ASYMMETRIC WIND FIELD WITH THE STRONGEST WINDS CONTAINED
IN THE NORTHEAST QUADRANT. THE ENVIRONMENT IS MARGINALLY FAVORABLE
WITH LOW (05-10 KNOTS) VERTICAL WIND SHEAR (VWS) AND WARM (28-29
CELSIUS) SEA SURFACE TEMPERATURE (SST) BEING OFFSET BY FAIR POLEWARD
OUTFLOW AND DRY AIR ENTRAINMENT FROM AN AREA OF UPPER-LEVEL
CONVERGENCE TO THE SOUTH. TS 09W IS TRACKING ALONG THE SOUTHWEST
PERIPHERY OF A SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE OVERALL FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. THROUGH TAU 48, TS 09W IS FORECAST TO TRACK GENERALLY
NORTHWESTWARD TOWARD SASEBO UNDER THE STEERING INFLUENCE OF THE
AFOREMENTIONED STR. MODEL GUIDANCE IS IN GOOD AGREEMENT FOR THIS
PORTION OF THE FORECAST WITH THE SPREAD AT 48 HOURS AT APPROXIMATELY
55 NM. AFTER PASSING SASEBO AROUND TAU 48, TS 09W IS EXPECTED TO
BEGIN A GRADUAL POLEWARD TURN AS IT ROUNDS THE STR AXIS. UNTIL
LANDFALL IN JAPAN AROUND TAU 30, TS 09W IS EXPECTED TO SLOWLY
INTENSIFY TO AROUND 50 KNOTS AS THE ENVIRONMENT REMAINS MARGINAL DUE
TO POOR UPPER LEVEL DIVERGENCE AND THE EFFECTS OF DRY AIR
ENTRAINMENT. THE RUGGED TERRAIN OF KYUSHU WILL HAMPER ANY
INTENSIFICATION OF TS 09W AFTER LANDFALL. A SECOND LANDFALL SHOULD
OCCUR NEAR BUSAN, KOREA AROUND TAU 48. BASED ON TIGHT GROUPING OF
THE MODEL DATA AND THE STEADY INFLUENCE OF THE STR, THERE IS HIGH
CONFIDENCE IN THIS PORTION OF THE JTWC TRACK FORECAST.
C. AFTER TAU 72, TS 09W WILL CONTINUE RECURVING AS IT ROUNDS THE
STR AXIS, PASSING INTO THE SEA OF JAPAN. THROUGHOUT THIS PERIOD,
LAND INTERACTION, INCREASING VWS, AND COOLER SST SHOULD WEAKEN THE
SYSTEM. BY TAU 72, TS 09W WILL BEGIN INTERACTING WITH THE MID-
LATITUDE BAROCLINIC ZONE AND START UNDERGOING EXTRATROPICAL
TRANSITION (ETT). ETT SHOULD COMPLETE PRIOR TO TAU 120. AS THE SYSTEM
ROUNDS THE STR AXIS, SPREAD IN MODEL GUIDANCE INCREASES
SIGNIFICANTLY, PRIMARILY DUE TO DIFFERENCES IN ALONG-TRACK SPEED. FOR
THIS REASON, THERE IS LOW CONFIDENCE IN THE EXTENDED PORTION OF THE
JTWC TRACK FORECAST.//
NNNN
Location: 17.6°N 131.4°E
Maximum Winds: 30 kt ( 55km/h)
Gusts: 40 kt ( 75km/h)
Minimum Central Pressure: 997 mb
WDPN31 PGTW 041500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 10W (TEN) WARNING
NR 03//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 10W (LEKIMA), LOCATED APPROXIMATELY 570 NM
SOUTH-SOUTHEAST OF KADENA AB, HAS TRACKED NORTHWARD AT 11 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
(EIR) REVEALS AN AREA EMBEDDED IN A BROAD CIRCULATION WHERE
SUSTAINED CONVECTION IN THE WESTERN SEMICIRCLE APPEARS TO BE CAUSING
CONSOLIDATION. THERE IS MODERATE CONFIDENCE IN THE INITIAL POSITION,
PLACED WITHIN THE APPARENT SHALLOW BANDING SEEN IN A 041004Z SSMIS
91 GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY OF 30 KTS IS BASED ON
MULTIPLE AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T1.5-2.0 (25-
35 KTS). A 041251Z METOP-B ASCAT PASS CONFIRMS THE POSITION AND
INTENSITY ESTIMATE, SHOWING A CIRCULATION WITH A LARGE AREA OF
APPROXIMATELY 35-45 KT WESTERLY WINDS OVER 100 NM TO THE SOUTH OF
THE CURRENT POSITION. THE ENVIRONMENT IS FAVORABLE WITH GOOD
EQUATORWARD AND POLEWARD OUTFLOW, WARM (29-30 CELSIUS) SEA SURFACE
TEMPERATURE AND LOW (10-15 KT) VERTICAL WIND SHEAR (VWS). TD 10W IS
DRIFTING GENERALLY POLEWARD UNDER WEAK STEERING INFLUENCE FROM A
SUBTROPICAL RIDGE (STR) TO THE WEST OF TD 10W.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE OVERALL FORECAST PHILOSOPHY SINCE
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. THROUGH TAU 48, TD 10W IS EXPECTED TO DRIFT SLOWLY POLEWARD
ALONG THE EASTERN EXTENSION OF THE STR. BETWEEN TAU 48 AND 72, THE
STR EXTENSION TO THE NORTH WILL TAKE OVER AS THE PRIMARY STEERING
INFLUENCE AND THE TRACK SHOULD SHIFT MORE NORTHWESTWARD. TD 10W IS
EXPECTED TO INTENSIFY STEADILY, REACHING 55 KTS BY TAU 72. MOST OF
THE UNCERTAINTY IN THE MODEL GUIDANCE FOR THIS PORTION OF THE
FORECAST IS IN THE EARLY TAUS AS THE MODEL TRACKERS ARE LIKELY
HAVING DIFFICULTY IDENTIFYING THE LLCC IN THE BROADER CIRCULATION.
OVERALL, THERE IS VERY LOW CONFIDENCE IN THE EARLY PORTION OF THE
FORECAST WITH A 350 NM SPREAD AT TAU 72, LARGELY OWING TO HIGH
UNCERTAINTY IN THE INITIAL POSITION AND SUBSEQUENT UNCERTAINTY IN
THE MODEL TRACK GUIDANCE.
C. BEYOND TAU 72, TD 10W IS EXPECTED TO CONTINUE ON A
NORTHWESTWARD TRACK ALONG THE SOUTHWEST PERIPHERY OF THE STR AND TO
INCREASE STEADILY INTENSITY TO 90 KTS BY TAU 120. INTENSITY GUIDANCE
IS IN FAIR AGREEMENT DUE TO A FAVORABLE ENVIRONMENT THROUGHOUT THE
FORECAST PERIOD WITH LIMITED DEVIATION THROUGH TAU 120; HOWEVER, THE
INTENSITY UNCERTAINTY IS HIGHLY SENSITIVE TO THE HIGH TRACK
UNCERTAINTY. TRACK GUIDANCE, IS IN POOR AGREEMENT WITH A SPREAD OF
NEARLY 1000NM BETWEEN GFS AND NAVGEM AT TAU 120, LIKELY IN PART TO
THE HIGH UNCERTAINTY IN THE INITIAL
POSITION.//
NNNN
09W: WARNING 12. PEAK INTENSITY OF 50KNOTS FORECAST WITHIN THE NEXT 48H
10W: WARNING 3. PEAK INTENSITY OF 90KNOTS FORECAST IN 120H.
04/15UTC. FRANCISCO(09W)
04/1114UTC. FRANCISCO(09W)
04/15UTC. LEKIMA(10W).
04/1251UTC. LEKIMA(10W)
09W: TRACK AND INTENSITY GUIDANCE
10W: TRACK AND INTENSITY GUIDANCE
