WPAC: MEKKHALA - Post-Tropical

[euro6208]

WDPN31 PGTW 100300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (SEVEN) WARNING
NR 003//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 07W (SEVEN), LOCATED APPROXIMATELY 305 NM
SOUTHEAST OF HONG KONG, HAS TRACKED NORTHWARD AT 09 KNOTS OVER THE
PAST SIX HOURS. THE CURRENT POSITION IS SITUATED DOWNSTREAM FROM A
CENTER FEATURE EVIDENT IN 092233Z SSMIS IMAGERY AND NEAR SATELLITE
POSITION FIXES FROM PGTW AND RJTD. THE INTENSITY OF 35 KNOTS IS
BASED ON A CONSENSUS OF RECENT SUBJECTIVE DVORAK AND AUTOMATED
INTENSITY ESTIMATES FROM MULTIPLE REPORTING AGENCIES, AND A 100031Z
METOP-A ASCAT PASS SHOWING AN AREA OF 35 KNOT WINDS WITHIN THE
SOUTHERN PORTION OF THE LOW-LEVEL CIRCULATION. DEEP CONVECTION HAS
INCREASED OVER THE CIRCULATION AND CONVECTIVE BANDING HAS BECOME
MORE DEFINED OVER THE PAST SIX HOURS. TS 07W IS TRACKING POLEWARD
ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE (STR)
EXTENSION. THE SYSTEM IS SITUATED IN AN AREA OF MODERATE (15-20 KTS)
VERTICAL WIND SHEAR AND VERY WARM (29-30C) SEA SURFACE TEMPERATURES.
UPPER-LEVEL DIFFLUENCE IS LIMITED, BUT AN ANALYSIS OF SATELLITE-
DERIVED ATMOSPHERIC MOTION VECTORS SUGGESTS THAT SOUTHWESTWARD
OUTFLOW IS INCREASING.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 07W WILL CONTINUE TO TRACK POLEWARD ALONG THE STR THROUGH
THE FORECAST PERIOD, MAKING LANDFALL IN SOUTHEASTERN CHINA JUST
AFTER TAU 24. STEADY INTENSIFICATION IS ANTICIPATED PRIOR TO
LANDFALL, DESPITE PERSISTENT VERTICAL WIND SHEAR, DUE TO CONTINUED
PASSAGE OVER VERY WARM WATER AND INCREASING POLEWARD OUTFLOW AIDED
BY AN UPPER-LEVEL TROUGH TO THE NORTHEAST. AFTER THE SYSTEM MAKES
LANDFALL, IT WILL WEAKEN DUE TO THE FRICTIONAL EFFECTS OF LAND AND
DISSIPATE BY TAU 48. NUMERICAL MODEL FORECASTS ARE IN GOOD AGREEMENT
REGARDING THE OVERALL FORECAST SCENARIO, BUT THERE IS SOME SPREAD IN
THE EXACT DIRECTION AND SPEED OF MOVEMENT. OVERALL, THERE IS FAIR
CONFIDENCE IN JTWC TRACK FORECAST.//
NNNN

[Hayabusa]

TS 2006 (Mekkhala)
Issued at 04:05 UTC, 10 August 2020

<Analysis at 03 UTC, 10 August>
Scale -
Intensity -
Center position N19°30' (19.5°)
E118°35' (118.6°)
Direction and speed of movement N 15 km/h (8 kt)
Central pressure 998 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
≥ 30 kt wind area ALL 185 km (100 NM)

[Ed_2001]

[euro6208]

WDPN31 PGTW 100900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (MEKKHALA) WARNING
NR 004//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 07W (MEKKHALA), LOCATED APPROXIMATELY
332 NM SOUTH-SOUTHWEST OF TAIPEI, TAIWAN, HAS TRACKED NORTHWARD
AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC) WITH CONVECTIVE BANDING OVER THE
SOUTHERN SEMICIRCLE WRAPPING INTO THE CENTER. THE CURRENT
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PARTIALLY
EXPOSED LLCC IN THE MSI LOOP AND THE LOW LEVEL CIRCULATION FEATURE
PRESENT IN A 100535Z AMSR2 89GHZ IMAGE. THE INTENSITY OF 35 KNOTS
IS PLACED WITH HIGH CONFIDENCE AND IS BASED ON MULTIAGENCY DVORAK
CURRENT INTENSITY ESTIMATES OF T2.0 (30 KTS, RJTD) AND T2.5 (35 KTS,
PGTW), A 100610Z ADVANCED DVORAK TECHNIQUE CURRENT INTENSITY ESTIMATE
OF T2.4 (34 KTS) AND A 100610Z SATCON ESTIMATE OF 36 KTS. TS MEKKHALA
IS TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL
STEERING RIDGE (STR) EXTENSION. THE SYSTEM IS SITUATED IN AN AREA OF
HIGH (25-30 KTS) VERTICAL WIND SHEAR AND VERY WARM (29-30C) SEA
SURFACE TEMPERATURES. UPPER-LEVEL DIFFLUENCE IS LIMITED, BUT AN
ANALYSIS OF SATELLITE-DERIVED ATMOSPHERIC MOTION VECTORS SUGGESTS THAT
EQUATORWARD OUTFLOW ALOFT CONTINUES TO STRENGTHEN.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 07W WILL CONTINUE TO TRACK POLEWARD ALONG THE STR THROUGH THE
ENTIRE 48 HOUR FORECAST PERIOD. THE SYSTEM WILL CONTINUE TO STEADILY
INTENSIFY TO 45 KTS BY TAU 12 DESPITE THE PERSISTENT HIGH VWS, LARGELY
DUE TO CONTINUED PASSAGE OVER VERY WARM WATER AND INCREASING POLEWARD
OUTFLOW AIDED BY AN UPPER-LEVEL TROUGH POSITIONED TO THE NORTHEAST. TS
MEKKHALA IS EXPECTED TO MAKE LANDFALL IN SOUTHEASTERN CHINA JUST PRIOR
TO TAU 48. AFTER THE SYSTEM MAKES LANDFALL IT WILL BEGIN TO WEAKEN DUE
TO THE FRICTIONAL EFFECTS OF LAND AND FULLY DISSIPATE OVER LAND BY TAU
48. NUMERICAL MODEL SOLUTIONS ARE IN FAIR AGREEMENT REGARDING THE OVERALL
FORECAST SCENARIO, BUT THERE IS SOME SPREAD IN THE EXACT POSITION OF
LANDFALL WITH A 60NM CROSS TRACK SPREAD IN SOLUTIONS AT TAU 48. OVERALL,
MODEL SOLUTIONS LEND FAIR CONFIDENCE IN JTWC TRACK FORECAST.//
NNNN

[doomhaMwx]

Looking impressive on radar imagery. Cannot be ruled out that this could be a strong/severe TS when it makes landfall.

[euro6208]

TPPN11 PGTW 101226

A. TROPICAL STORM 07W (MEKKHALA)

B. 10/1150Z

C. 21.50N

D. 118.76E

E. FIVE/HMWRI8

F. T3.0/3.0/D2.0/24HRS STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .60 ON LOG10 SPIRAL
YIELDING A DT OF 3.0. MET/PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


MARTIN

[mrbagyo]

[mrbagyo]

Mekkhala's intensity was pegged at 35 knots by JTWC at the time of this microwave image

[euro6208]

Clearly a typhoon at this point.

Estimates are lagging.

Recon would find this stronger.

[EquusStorm]

Sometimes the JTW in JTWC stands for Judging Too Weak lol

[mrbagyo]

eh despite having an eyelike feature, 1350z ASCAT MetOp-C pass' highest barb was only 35 knots (located on the southeastern periphery of the circulation) - maybe just a resolution issue idk

Would love to see actual data to get a better idea of it's true intensity (is there any buoys in that area?)

[mrbagyo]

last loop before I sleep

Zhangzhou radar

[doomhaMwx]

07W MEKKHALA 200810 2100 23.5N 117.9E WPAC 60 987
07W MEKKHALA 200810 1800 22.9N 118.2E WPAC 55 990

STS 2006 (Mekkhala)
Issued at 22:00 UTC, 10 August 2020

<Analysis at 21 UTC, 10 August>
Scale -
Intensity -
Center position N23°25' (23.4°)
E118°00' (118.0°)
Direction and speed of movement N 25 km/h (13 kt)
Central pressure 992 hPa
Maximum wind speed near center 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
≥ 30 kt wind area SE 220 km (120 NM)
NW 165 km (90 NM)

It's making landfall. Good thing JTWC added a 21Z point.

[Ed_2001]

Apparently, NMC (China’s meteorological center) just upgraded it to a minimal typhoon based on a buoy measuring 10 minute sustained wind of 32.9m/s (74mph) and a pressure of 985.1mb just outside of the eye.

[1900hurricane]

Apparently, NMC (China’s meteorological center) just upgraded it to a minimal typhoon based on a buoy measuring 10 minute sustained wind of 32.9m/s (74mph) and a pressure of 985.1mb just outside of the eye.

The buoy ID number appears to be 59334, but I can't find obs from it anywhere. Anyone have a link perchance? It's also possible that it's not publicly available.

[doomhaMwx]

ZCZC
WHCI40 BABJ 102330
TY 2006 (2006) MEKKHALA LANDED ON ZHANGPU FUJIAN PROVINCE
102330GMT (33m/s)
NNNN

[Ed_2001]

Apparently, NMC (China’s meteorological center) just upgraded it to a minimal typhoon based on a buoy measuring 10 minute sustained wind of 32.9m/s (74mph) and a pressure of 985.1mb just outside of the eye.

The buoy ID number appears to be 59334, but I can't find obs from it anywhere. Anyone have a link perchance? It's also possible that it's not publicly available.

I saw it on a Chinese weather forum, but I think you're right, a lot of weather data in China isn't publicly viewable. But I could be wrong.

[euro6208]

07W MEKKHALA 200810 2100 23.5N 117.9E WPAC 70 980

We have a cat 1 landfall...

[doomhaMwx]

There was also a ship at 22.2N 117.4E but it was far enough that it only experience weak TS conditions at most (16Z). Well, it was actually lucky.

[doomhaMwx]

From 45kts to 65kts real quick.

07W MEKKHALA 200811 0000 24.1N 117.7E WPAC 70 980
07W MEKKHALA 200810 2100 23.5N 117.9E WPAC 70 980
07W MEKKHALA 200810 1800 22.9N 118.2E WPAC 65 984
07W MEKKHALA 200810 1200 21.6N 118.5E WPAC 45 991