WPAC: Tropical Depression 90W

[Nancy Smar]

90W INVEST 200727 1800 25.0N 162.0E WPAC 15 0

[Nancy Smar]

TROPICAL DEPRESSION 1010 HPA AT 25N 163E WEST 15 KT.

[Nancy Smar]

90W INVEST 200728 0000 25.3N 161.8E WPAC 15 1010

[1900hurricane]

I didn't realize threads could still exist in this forum.

[euro6208]

[doomhaMwx]

Choose one center.

[Nancy Smar]

ABPW10 PGTW 280600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS/280600Z-290600ZJUL2020//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 90W) HAS PERSISTED NEAR
24.5N 160.4E, APPROXIMATELY 467 NM NORTHWEST OF WAKE ISLAND. THE
SYSTEM IS CURRENTLY CLASSIFIED AS A SUBTROPICAL SYSTEM, GENERALLY
CHARACTERIZED AS HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE
FEATURES. RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A
280250Z ASMR2 89 GHZ MICROWAVE IMAGE DEPICT A BROAD OVERALL
STRUCTURE WITH DISORGANIZED CONVECTION AND TWO DISTINCT SMALL
CIRCULATIONS ROTATING ABOUT A CENTROID. ADDITIONALLY, WEAK SHALLOW
BANDING IS PRESENT AND WRAPPING AROUND THE BROAD CENTER. A 272330Z
ASCAT-B IMAGE INDICATES AN ASYMMETRIC WIND FIELD WITH 20-25KT WINDS
AROUND THE NORTHERN SEMICIRCLE WITH A LARGE RADIUS OF MAXIMUM WINDS
(>100NM). UPPER LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH
CYCLONIC EASTERLY FLOW AND MODERATE TO STRONG VERTICAL WIND SHEAR
(20-30KTS). HOWEVER, THE SYSTEM IS CURRENTLY LOCATED OVER WARM (28-
30C) SEA SURFACE TEMPERATURES. MODEL ANALYSIS INDICATES THE SYSTEM
IS LOCATED UNDER THE NORTHERN PERIPHERY OF A 500MB LOW. THE SYSTEM
IS EXPECTED TO RECURVE POLEWARD IN THE NEXT 36-48 HOURS WHILE
BECOMING ABSORBED IN AN APPROACHING FRONTAL SYSTEM. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. FOR HAZARDS AND
WARNINGS, REFERENCE THE FLEET WEATHER CENTER SAN DIEGO HIGH WINDS
AND SEAS PRODUCT OR REFER TO LOCAL WMO DESIGNATED FORECAST
AUTHORITY. THE POTENTIAL FOR THE SYSTEM TO TRANSITION INTO A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.
(2) NO OTHER SUBTROPICAL SYSTEMS.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
NNNN

[Nancy Smar]

90W INVEST 200728 0600 24.5N 160.4E WPAC 25 1006

[Hayabusa]

JMA and JTWC can't help it that July could be a new quiet record they started to classify a subtropical cyclone, unlike in the Atlantic like they always do.

[euro6208]

If NHC can classify subtropical cyclones, why can't JTWC do the same?

Probably a couple of these a year go unnoticed and unclassified.

They are still destructive and can cause casualties.

[euro6208]

90W INVEST
As of 18:00 UTC Jul 28, 2020:

Location: 25.5°N 159.2°E
Maximum Winds: 25 kt
Minimum Central Pressure: 1008 mb

[euro6208]

THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED
NEAR 24.5N 160.4E IS NOW LOCATED NEAR 26.8N 158.2E, APPROXIMATELY
644 NM NORTHWEST OF WAKE ISLAND. THE SYSTEM IS CURRENTLY CLASSIFIED
AS A SUBTROPICAL SYSTEM, GENERALLY CHARACTERIZED AS HAVING BOTH
TROPICAL AND MIDLATITUDE CYCLONE FEATURES. RECENT ANIMATED
MULTISPECTRAL SATELLITE IMAGERY AND A 282309Z METOP-B 89 GHZ
MICROWAVE IMAGE DEPICT A BROAD OVERALL STRUCTURE WITH DISORGANIZED
CONVECTION AND TWO DISTINCT SMALL CIRCULATIONS ROTATING ABOUT A
CENTROID. A 282155Z ASCAT-A IMAGE INDICATES AN ASYMMETRIC WIND FIELD
WITH 25-30KT WINDS AROUND THE EASTERN SEMICIRCLE WITH A LARGE RADIUS
OF MAXIMUM WINDS (90-95NM). UPPER LEVEL ANALYSIS INDICATES A
MARGINAL ENVIRONMENT WITH CYCLONIC EASTERLY FLOW AND MODERATE TO
STRONG VERTICAL WIND SHEAR (15-25KTS). HOWEVER, THE SYSTEM IS
CURRENTLY LOCATED OVER WARM (28-30C) SEA SURFACE TEMPERATURES. MODEL
ANALYSIS INDICATES THE SYSTEM IS LOCATED UNDER THE NORTHERN
PERIPHERY OF A 500MB LOW. THE SYSTEM IS EXPECTED TO RECURVE POLEWARD
IN THE NEXT 24-36 HOURS WHILE BECOMING ABSORBED IN AN APPROACHING
FRONTAL SYSTEM. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25
TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

[euro6208]

Poof.