Tropical Storm ONE Advisory Wed Jul 22

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 01C (HALOLA) WARNING NR 50//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
  TYPHOON (TY) 01C (HALOLA), LOCATED APPROXIMATELY 554 NM EAST-
SOUTHEAST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED
WEST-NORTHWESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED
ENHANCED INFRARED (EIR) SATELLITE IMAGERY (MSI) SHOWS A COMPACT
SYSTEM THAT HAS MAINTAINED TIGHTLY CURVED BANDING EVEN AS THE EYE HAS
BECOME CLOUD-FILLED. THE LLCC REMAINS WELL-DEFINED AS EVIDENCED BY A
MICROWAVE EYE FEATURE IN THE 220955Z F18 91GHZ IMAGE. THE INITIAL
POSITION IS BASED ON THE EIR LOOP AND ON THE MICROWAVE IMAGE WITH
HIGH CONFIDENCE. THE INITIAL
INTENSITY OF 75 KNOTS BASED ON AN OVERALL ASSESSMENT OF DVORAK
ESTIMATES FROM PGTW, KNES, AND RJTD. UPPER LEVEL ANALYSIS INDICATES
THE SYSTEM IS IN AN AREA OF LIGHT VWS WITH GOOD EQUATORWARD OUTFLOW.
TY 01C IS TRACKING ALONG THE SOUTHERN PERIPHERY OF THE DEEP-LAYERED
STR TO THE NORTH.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY HALOLA WILL CONTINUE TRACKING WEST-NORTHWESTWARD UNDER THE
STEERING INFLUENCE OF THE STR THROUGH TAU 48. IT IS FORECAST TO
INTENSIFY OVER THE NEXT 36 HOURS - PEAKING AT 95 KNOTS - DUE TO
CONTINUED FAVORABLE ENVIRONMENTAL CONDITIONS WITH GOOD OUTFLOW, LOW
VWS, AND SSTS ABOVE 28 CELSIUS. BEYOND TAU 48, VWS WILL INCREASE
WHICH WILL BEGIN TO WEAKEN THE SYSTEM. DYNAMIC MODEL GUIDANCE IS IN
TIGHT AGREEMENT THROUGH TAU 48, LENDING TO HIGH CONFIDENCE IN THIS
PORTION OF THE FORECAST.
   C. IN THE EXTENDED TAUS, THE SYSTEM WILL BEGIN TO TURN POLEWARD
AS IT ROUNDS THE SOUTHWESTERN PERIPHERY OF THE STEERING STR. TY
HALOLA SHOULD CONTINUE TO WEAKEN DUE TO VWS ABOVE 30 KNOTS CAUSED BY
STRONG NORTHERLY FLOW FROM A BUILDING MID-LATITUDE RIDGE TO THE
NORTHWEST, SSTS DROPPING BELOW 26 CELSIUS, THEN LAND INTERACTION WITH
JAPAN. DYNAMIC MODEL GUIDANCE SPREADS OUT AFTER TAU 48 DUE TO VARYING
DEGREES IN THE TIMING OF THE RE-CURVE AND CONW MEMBERS CONTINUE TO
STRUGGLE TO CONVERGE ON A SOLUTION REGARDING THE WESTERN EXTENT OF
THE STR TO THE NORTH. THIS UNCERTAINTY LEADS TO AN OVERALL LOW
CONFIDENCE IN THE JTWC FORECAST.//
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