WPAC: FRANCISCO - Post-Tropical

[1900hurricane]

Miyazaki recorded a 982.8 mb pressure at 20Z, which as far as I can tell, was also the landfall time. Schloemer inputs are touchy with small storms like this, but as far as I can tell, JMA's 970 mb estimated minimum pressure looks rather reasonable. I used that pressure with a 10 nm distance, 10 nm RMW, and 1001 mb outermost closed isobar I estimated from JMA surface analysis and got about 972 mb.

If I then backtrack that pressure through KZC using the same OCI (a little lower than JTWC's 1004 mb), but other JTWC inputs (forward speed of 11 kt, average r34 of 100 nm/rOCI of 155 nm) and landfall latitude of 32.1ºN, I'm getting about 65 kt. Regression of JMA's wind radii (0.7272 * rJMAavg + 3.9259) gives me an r34 of 102.1 nm, functionally the same as JTWC's.

Therefore, I'd probably set landfall intensity to 65 kt/972 mb. The 65 kt is a little lower than JTWC's 75 kt and JMA's 70 kt, but perhaps jives a little better with the somewhat unimpressive surface obs.

[Tailspin]

Jason Harris chased it.

Surprising little typhoon in the end. Really got it's act together in the last few hours. SATCON went to 82 knots which might turn out to be about right. There was a period just after the system had crossed where backside winds were filling the air with thick debris fields. I'll try to upload some video later this evening when we get back to Fukuoka.

Screen shot of our position when we were experiencing strongest winds attached

Link: https://youtu.be/E9SjAwzoLCg
https://youtu.be/E9SjAwzoLCg

[euro6208]

Anyone having problems accessing the JTWC website?

[euro6208]

WDPN32 PGTW 060300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (FRANCISCO) WARNING
NR 18//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 09W (FRANCISCO), LOCATED APPROXIMATELY 61 NM
EAST OF SASEBO, JAPAN, HAS TRACKED NORTHWESTWARD AT 16 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS TS 09W
REMAINS TIGHTLY WRAPPED. HOWEVER, IT NO LONGER HAS A DEFINED EYE
FEATURE DUE TO LAND INTERACTION WITH KYUSHU. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE AND IS BASED ON A 052330Z HIMAWARI
INFRARED SATELLITE IMAGE WHICH SHOWS A NOTCH FEATURE. THE INITIAL
INTENSITY ESTIMATE OF 60 KNOTS IS BASED ON A WEAKENING TREND OVER
LAND. ENVIRONMENTAL ANALYSIS SHOWS TS 09W IS EXPERIENCING FAVORABLE
VERTICAL WIND SHEAR (10 TO 15 KNOTS). TS 09W ALSO HAS EXCELLENT
POLEWARD BUT A LIMITED EQUATORWARD OUTFLOW CHANNEL. TS 09W IS
CURRENTLY OVER LAND, HOWEVER, THE SURROUNDING SEA SURFACE
TEMPERATURES REMAIN FAVORABLE (28 TO 29 DEGREES CELSIUS). TS 09W IS
TRACKING NORTHWESTWARD WHILE UNDER THE INFLUENCE OF A SUBTROPICAL
RIDGE (STR) LOCATED TO THE SOUTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE OVERALL FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 09W WILL TRACK NORTH-NORTHWESTWARD THROUGH TAU 12 WHILE IT
REMAINS UNDER THE INFLUENCE OF THE AFOREMENTIONED STR. SHORTLY AFTER
TAU 06, TS 09W WILL TRACK BACK OVER WATER WHICH WILL SLOW THE
WEAKENING AND ALLOW TS 09W TO MAKE LANDFALL JUST EAST OF BUSAN WITH
AN INTENSITY OF 55 KNOTS. AN APPROACHING WEST TO EAST MOVING
SHORTWAVE TROUGH WILL HELP TO ACCELERATE TS 09W NORTHWARD AND
EVENTUALLY NORTHEASTWARD AFTER TAU 24. BY TAU 36, TS 09W WILL
INTERACT WITH THE BAROCLINIC ZONE AND BEGIN EXTRA-TROPICAL TRANSITION
(ETT). TS 09W WILL COMPLETE ETT BY TAU 72 AS IT ACCELERATES EASTWARD
AND MAINTAINS AN INTENSITY OF 40 KNOTS. NUMERICAL MODEL GUIDANCE IS
IN TIGHT AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC
FORECAST TRACK.//
NNNN

[euro6208]

WDPN32 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (FRANCISCO) WARNING
NR 19//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 09W (FRANCISCO), LOCATED APPROXIMATELY 47 NM
SOUTHEAST OF BUSAN, SOUTH KOREA, HAS TRACKED NORTHWESTWARD AT 18
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS THE SYSTEM REMAINS INTACT AS IT EXITED KYUSHU INTO THE
TSUSHIMA STRAIT; HOWEVER, THE CENTRAL CONVECTION APPEARS TO BE
ERODING AS EVIDENCED BY WARMING TOPS AND ELONGATION ALONG THE
NORTHERN FLANKS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON A DEFINED LOW LEVEL CIRCULATION ON A COMPOSITE RADAR LOOP
FROM NORTHERN KYUSHU. THE INITIAL INTENSITY OF 50 KNOTS IS HELD
SLIGHTLY LOWER THAN AGENCY FIXES TO REFLECT THE RAPID WEAKENING
TREND. THE INITIAL POSITION AND INTENSITY ARE SUPPORTED BY NEARBY
SURFACE OBSERVATIONS INCLUDING THOSE FROM TSUSHIMA ISLAND, 10 NM TO
THE WEST. ENVIRONMENTAL ANALYSIS SHOWS TS 09W HAS DRIFTED INTO
INCREASING SOUTHEASTERLY VERTICAL WIND SHEAR (20 TO 25 KNOTS) CAUSING
A SLIGHT FORWARD TILT. THE VWS IS PARTLY OFFSET BY EXCELLENT POLEWARD
OUTFLOW AND MARGINAL SST (26 CELSIUS). THE CYCLONE IS TRACKING UNDER
THE INFLUENCE OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE EAST-NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE OVERALL FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 09W WILL CONTINUE TO TRACK NORTHWESTWARD THROUGH TAU
12 UNDER THE STR, MAKING LANDFALL NEAR BUSAN WITHIN SIX HOURS. AFTER
TAU 12, IT WILL BEGIN TO ROUND THE STR AXIS AND TURN NORTHWARD THEN
NORTHEAST- TO EAST-NORTHEASTWARD, DRAG ALONG THE EASTERN SOUTH KOREAN
MOUNTAIN RANGE, THEN CROSS THE SEA OF JAPAN (SOJ) BEFORE MAKING
LANDFALL OVER HOKKAIDO BY TAU 72. INCREASING VWS, LAND INTERACTION,
AND COOLING SSTS IN THE SOJ WILL CONTINUE TO RAPIDLY ERODE THE
SYSTEM. CONCURRENTLY, BY TAU 36, IT WILL BEGIN EXTRA-TROPICAL
TRANSITION IN THE SOJ AND MAINTAIN A LARGE WIND FIELD. BY TAU 72, TS
09W WILL BECOME A COLD CORE LOW AFTER IT MAKES LANDFALL IN HOKKAIDO.
NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[doomhaMwx]

TS Francisco made landfall over Busan, South Korea at around 8pm KST this Tuesday night according to the KMA.
Due to Francisco's small size and with increasing southwesterly shear already affecting the storm, impacts/effects from the system are expected to be confined to the eastern parts of the Korean Peninsula.

[euro6208]

WDPN32 PGTW 070300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (FRANCISCO) WARNING
NR 22//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 09W (FRANCISCO), LOCATED APPROXIMATELY 101 NM EAST-
NORTHEAST OF INCHON, SOUTH KOREA, HAS TRACKED NORTHWARD AT 13 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY AND A 062206Z SSMIS 91GHZ IMAGE DEPICT A RAPIDLY DECAYING
SYSTEM WITH DEEP CONVECTION SHEARED NORTH OF A BROAD LOW-LEVEL
CIRCULATION CENTER (LLCC). RADAR IMAGERY INDICATES A DISORGANIZED,
BROAD LLCC WITH CONVECTIVE BANDING WRAPPING INTO THE CENTER, WHICH
SUPPORTS THE INITIAL POSITION WITH FAIR CONFIDENCE. THE INITIAL
INTENSITY IS ASSESSED AT 35 KNOTS, HEDGED ABOVE THE RJTD DVORAK
INTENSITY ESTIMATES OF T2.0 (30 KNOTS), BASED ON THE CONVECTIVE
STRUCTURE. TS 09W IS LOCATED UNDER THE LEADING EDGE OF A SHARP UPPER-
LEVEL SHORTWAVE TROUGH AND IS UNDER SOUTHERLY VERTICAL WIND SHEAR
(VWS). THE SYSTEM IS TRACKING UNDER THE INFLUENCE OF A SUBTROPICAL
RIDGE (STR) LOCATED TO THE EAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE OVERALL FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 09W IS FORECAST TO RECURVE NORTHEASTWARD TO EASTWARD OVER
THE NEXT 36 TO 48 HOURS WHILE UNDERGOING EXTRA-TROPICAL TRANSITION
(ETT). THE SYSTEM WILL REMAIN A WEAK TS AS IT BECOMES EMBEDDED
IN THE MIDLATITUDE WESTERLIES AND ENCOUNTERS INCREASING VWS AND
COOLER SST. TS 09W SHOULD COMPLETE ETT BY TAU 24 AS IT GAINS FRONTAL
CHARACTERISTICS BUT IS FORECAST TO MAINTAIN GALE-FORCE WINDS.
NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

WTPN32 PGTW 070900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL STORM 09W (FRANCISCO) WARNING NR 023//
RMKS/
1. TROPICAL STORM 09W (FRANCISCO) WARNING NR 023
03 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
070600Z --- NEAR 39.6N 129.3E
MOVEMENT PAST SIX HOURS - 020 DEGREES AT 16 KTS
POSITION ACCURATE TO WITHIN 030 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND SYNOPTIC DATA
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
REPEAT POSIT: 39.6N 129.3E
---
FORECASTS:
12 HRS, VALID AT:
071800Z --- 41.6N 132.0E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 065 DEG/ 15 KTS
---
24 HRS, VALID AT:
080600Z --- 42.8N 135.6E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 080 DEG/ 18 KTS
---
36 HRS, VALID AT:
081800Z --- 43.2N 140.5E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
070900Z POSITION NEAR 40.1N 130.0E.
07AUG19. TROPICAL STORM (TS) 09W (FRANCISCO), LOCATED APPROXIMATELY
166 NM NORTHEAST OF SEOUL, SOUTH KOREA, HAS TRACKED
NORTH-NORTHEASTWARD AT 16 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES THE SYSTEM HAS EXITED
INTO THE SEA OF JAPAN (SOJ) AND HAS BEGUN EXTRA-TROPICAL TRANSITION
(ETT), CHARACTERIZED BY AN EXPOSED, WEAK, RAGGED, ELONGATED, BUT
EXPANDING LOW LEVEL CIRCULATION. THE INITIAL POSITION AND INTENSITY
ARE PLACED WITH FAIR CONFIDENCE BASED ON THE MSI LOOP AND BUOY
OBSERVATIONS IN THE SOJ. TS 09W WILL ACCELERATE NORTHEASTWARD ON THE
POLEWARD SIDE OF THE 500MB SUBTROPICAL RIDGE AND COMPLETE ETT BY TAU
12, BECOMING A GALE-FORCE COLD CORE LOW WITH AN EXPANDING WIND FIELD
AS IT EMBEDS IN THE BAROCLINIC ZONE. ITS REMNANTS WILL CROSS THE SOJ
AND MAKE LANDFALL OVER HOKKAIDO BY TAU 36. 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. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 070600Z IS 14 FEET. REFER TO TYPHOON 10W
(LEKIMA) WARNINGS (WTPN31 PGTW) FOR SIX-HOURLY UPDATES. REFER TO
TROPICAL STORM 11W (KROSA) WARNINGS (WTPN33 PGTW) FOR SIX-HOURLY
UPDATES.//
NNNN