CPAC: INVEST 90C

[HURAKAN]

looks really nice this afternoon, surprised there hasn't been a Dvorak classification

[brunota2003]

[Chacor]

Should cross into the JMA's area within the next 12 hours. Has already appeared on the JMA's surface analysis map, but not yet in the high seas warning.

[Chacor]

JMA have this as a TD:

WARNING.
TROPICAL DEPRESSION 1004 HPA
AT 18.1N 179.7E MIDWAYS MOVING WEST 10 KNOTS.
POSITION FAIR.
MAX WINDS 30 KNOTS NEAR CENTER.

[brunota2003]

It appears to have been a TD prior to the crossover...surface low, organized convection near/over the surface center. No real frontal features other than the ULL, which is dying off now, in favor of an anticyclone.

[Chacor]

WARNING.
TROPICAL DEPRESSION 1004 HPA
AT 18.2N 178.4E MIDWAYS MOVING WEST 10 KNOTS.
POSITION FAIR.
MAX WINDS 30 KNOTS.

[Chacor]

JTWC:

AN AREA OF CONVECTION HAS PERSISTED NEAR 17.3N 178.5E,
APPROXIMATELY 680 NM EAST OF WAKE ISLAND. ANIMATED INFRARED
SATELLITE IMAGERY SHOWS FLARING CONVECTION NEAR THE LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH PERIPHERAL BANDS OVER THE EASTERN
SEMICIRCLE. A SERIES OF SCATTEROMETRY PASSES INDICATE CENTRAL WINDS
OF 10-15 KNOTS WITH STRONGER GRADIENT INDUCED PERIPHERAL WINDS OVER
THE NORTHERN AND EASTERN QUADRANTS, APPROXIMATELY 1.5-2.0 DEGREES
REMOVED FROM THE LLCC. A 080901Z AMSU-B IMAGE DEPICTS A SMALL DEEP
CONVECTIVE CLUSTER APPROXIMATELY 90 NM TO THE NORTH OF THE LLCC.
ANIMATED TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE LLCC TO BE
NEARLY COCOONED BY A RELATIVELY DRIER AIR MASS WITH LIMITED MOIST
AIR ENTRAINMENT PROVIDED BY TRADE WIND FLOW. ANIMATED WATER VAPOR
IMAGERY CLEARLY DEPICTS THE SUBSIDENT DRY AIRMASS THAT SURROUNDS
THE LLCC. THE MOST RECENT AMSU CROSS-SECTION (070900Z) REVEALS A
WEAK WARM CORE ANOMALY THAT IS HORIZONTALLY LARGE AND DISPLACED
HIGHER IN THE TROPOSPHERE THAN WHAT IS NORMALLY SEEN FOR A TYPICAL
WARM CORE TROPICAL DISTURBANCE. THEREFORE, DUE TO THE WEAK CENTRAL
WINDS, DISPLACED CONVECTION, AND TEMPERATURE CHARACTERISTICS, THIS
DISTURBANCE IS CLASSIFIED AS A SUB-TROPICAL SYSTEM. MODEL GUIDANCE
DOES NOT SUGGEST A TRANSITION INTO A WARM CORE TROPICAL SYSTEM BUT
RATHER OPENS THE CIRCULATION INTO A WAVE OVER THE NEXT FEW DAYS.
UPPER-LEVEL ANALYSIS SHOWS A CYCLONIC CIRCULATION POSITIONED
DIRECTLY OVER THE LLCC. SEA SURFACE TEMPERATURES ARE ON THE LOW
THRESHOLD FOR TROPICAL DEVELOPMENT AT 26-27 DEGREES CELSIUS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1009 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS LOW.

[Reesie]

558
TXPQ24 KNES 081533
TCSWNP

A. SUBTROPICAL DISTURBANCE (90C)

B. 08/1501Z

C. 17.9N

D. 177.4E

E. THREE/MTSAT

F. ST 1.5

G. IR/EIR/SWIR

H. REMARKS...WELL DEFINED CIRCULATION CENTER HAS HAD PERSISTENT
CONVECTION NEAR THE CENTER AND IN EASTERN SEMICIRCLE. STRONGEST WINDS..AS
EVIDENCED BY LOW LEVEL CLOUD FIELD IN IR ANIMATION AND EARLIER ASCAT
PASS ARE DISPLACED TO THE NORTH OF LLCC. SYSTEM EXHIBITING SUBTROPICAL
PATTERN AND EVOLUTION WITH CURRENT INTENSITY AT 1.5. PLEASE SEE ALSO
PGTW ABPW10 FOR ADDITIONAL DISCUSSION. FT IS BASED ON PT.

I. ADDL POSITIONS

NIL


...RUMINSKI

[HURAKAN]

floater:

http://www.ssd.noaa.gov/PS/TROP/floater ... oater.html

[cycloneye]

Does anyone know why it has not changed to a WPAC invest as it crossed into that basin?

[P.K.]

18Z:

WARNING.
TROPICAL DEPRESSION 1006 HPA
AT 17.7N 176.5E MIDWAYS MOVING WESTSOUTHWEST 18 KNOTS.
POSITION FAIR.
MAX WINDS 30 KNOTS NEAR CENTER.

[HURAKAN]

great circulation but lacking convection

[Chacor]

TROPICAL DEPRESSION 1006 HPA AT 19N 175E WEST 10 KT.

[cycloneye]

Does anyone know why it has not changed to a WPAC invest as it crossed into that basin?

Well,I am answering my question as I found this useful information. The specific topic of my question is in section 3-5.

http://www.ofcm.gov/nhop/11/pdf/03-chap3.pdf

[cycloneye]

TROPICAL DEPRESSION 1008 HPA AT 19N 172E WEST 10 KT.

[Ptarmigan]

Interesting to see a storm form during a dying La Nina in that area.

[cycloneye]

JMA still has it as TD.

TROPICAL DEPRESSION 1006 HPA AT 19N 169E WEST 10 KT

[cycloneye]

Gone from NRL site. It was a interesting low pressure in terms of the basin that formed on early April.