Tropical Storm MUIFA Advisory Sa, 10.09.

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 14W (MUIFA) WARNING NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
   INITIAL POSITION: 20.6N 126.1E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 360 NM SOUTH-SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 27 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A SYSTEM WITH
AN IMPROVING STRUCTURE THAT IS CONSOLIDATING AS THE CENTRAL
CONVECTION CONTINUES TO EXPAND AND AN EVER SO SLIGHT INDICATION OF
AN EYE TRYING TO FORM. A 092238Z SSMIS 37GHZ MICROWAVE PASS
INDICATES THE WEAK MICROWAVE EYE FEATURE IS STILL NOTICEABLE AS IT
WAS IN THE PREVIOUS SATELLITE ANALYSIS. TY MUIFA IS IN A FAVORABLE
ENVIRONMENT FOR FURTHER DEVELOPMENT OVER THE NEXT 48 HOURS WITH
GOOD POLEWARD AND WESTWARD OUTFLOW, LOW (5-10 KTS) VERTICAL WIND
SHEAR (VWS) AND VERY WARM (29-30 C) SEA SURFACE TEMPERATURES (SST).
IN ADDITION, WATER VAPOR IMAGERY SHOWS A TUTT TO THE NORTHWEST OF
THE ASSESSED LLCC WHICH IS INCREASING POLEWARD OUTFLOW AND ALLOWING
FOR BETTER CONSOLIDATION. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED OFF THE AFOREMENTIONED IMAGERY AND MULTIPLE AGENCY
FIXES. THE INITIAL INTENSITY OF 70 KTS IS ASSESSED WITH MEDIUM
CONFIDENCE BASED ON THE OVERALL CONVECTIVE STRUCTURE NOTED IN
MULTISPECTRAL IMAGERY AND THE MICROWAVE PASS, AS WELL AS A BLEND OF
MULTI-AGENCY DVORAK ESTIMATES.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST
AGENCY DVORAK AND AUTOMATED FIXES:
   PGTW: T4.0 - 65 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T4.0 - 65 KTS
   KNES: T4.5 - 77 KTS
   CIMSS SATCON: 56 KTS AT 092238Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD
ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: MEDIUM
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TY 14W HAS CONTINUED TO TRACK NORTHWESTWARD
OVER THE PAST 6 HOURS ALONG THE SOUTHWESTERN PERIPHERY OF THE
SUBTROPICAL RIDGE TO THE NORTHEAST. DUE TO THE FAVORABLE
ENVIRONMENT, TY MUIFA WILL GRADUALLY INCREASE IN INTENSITY TO 75
KTS BY TAU 12 AND 90 KTS BY TAU 24 AS IT CONTINUES TO TRACK
NORTHWESTWARD. BY TAU 36, TY MUIFA WILL BEGIN TO SLOW DOWN AND SET
UP A QUASI-STATIONARY POSTURE AS THE SUBTROPICAL RIDGE TO THE
NORTHEAST BUILDS IN TO THE NORTH. TY 14W WILL CONTINUE TO INCREASE
IN INTENSITY TO 100 KTS BY TAU 36 AND REACH ITS PEAK INTENSITY OF
110 KTS BY TAU 48. THE SLOW MOVEMENT AND THE INCREASE IN INTENSITY
WILL INDUCE UPWELLING WHICH WILL BE ONE OF THE CONTRIBUTING FACTORS
TO THE DECREASE IN INTENSITY BY TAU 72 TO 100 KTS AS THE SYSTEM
MAKES THE TURN NORTHWARD. ANOTHER CONTRIBUTING FACTOR TO THE
DECREASE IN INTENSITY IS UPPER LEVEL CONVERGENCE BROUGHT ON BY AN
APPROACHING DEEP LAYER TROUGH FROM THE WEST DURING THIS TIME. AS A
RESULT, TY 14W WILL INCREASE IN TRACK SPEED NORTHWARD. INTENSITY
WILL GRADUALLY DECREASE TO 80 KTS BY TAU 96 AND 65 KTS BY TAU 120
AS TY 14W MOVES INTO AN AREA OF WEAKER OUTFLOW ALOFT AND SLIGHTLY
COOLER SSTS.
MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN VERY TIGHT
AGREEMENT THROUGH TAU 48 WITH ONLY A 50NM SPREAD. HOWEVER, THERE IS A
BIFURCATION WITH CONSENSUS MEMBERS IN TRACK SPEED AROUND TAU 48.
NAVGEM, AFUM, AND EGRR DO NOT AGREE WITH THE OTHER CONSENSUS MEMBERS
OF A QUASI-STATIONARY SCENARIO. FOR THE PURPOSE OF THIS FORECAST THEY
WERE EXCLUDED. WITH THIS, THE JTWC FORECAST TRACK IS PLACED WITH
MEDIUM CONFIDENCE THROUGH TAU 72, AND LOW CONFIDENCE AFTER TAU 72
DUE TO THE COMPLEX ENVIRONMENT WITH THE QUASI-STATIONARY
OCCURRENCE. INTENSITY GUIDANCE REMAINS IN GOOD AGREEMENT SHOWING
RAPID INTENSIFICATION (RI) THROUGH TAU 48. AFTER WHICH, THE
INTENSITY GUIDANCE SHOWS A DECREASE LIKELY DUE TO THE ENVIRONMENTAL
CONDITIONS MENTIONED ABOVE. THE JTWC INTENSITY FORECAST IS SET
SLIGHTLY HIGHER THAN CONSENSUS WITH MEDIUM CONFIDENCE THROUGHOUT
THE FORECAST PERIOD.
FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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