2019 FEB 20 1355UTC WESTERN NORTH PACIFIC
TS #WUTIP #02W
This system is currently analysed as a 55knots TS.
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (WUTIP)
WARNING NR 06//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 02W (WUTIP), LOCATED APPROXIMATELY 675 NM
SOUTHEAST OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 11 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A CONSOLIDATING SYSTEM WITH IMPROVED CONVECTIVE
BANDING. A 200759Z WINDSAT 37GHZ IMAGE AND A 201119Z MHS 89GHZ
MICROWAVE IMAGE INDICATE DEEP CONVECTIVE BANDING WRAPPING INTO A
DEFINED LOW-LEVEL CIRCULATION CENTER, WHICH SUPPORTS THE INITIAL
POSITION WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT
55 KNOTS BASED ON A DVORAK INTENSITY ESTIMATE OF T3.5 (55 KNOTS)
FROM PGTW AND RJTD. ADDITIONALLY, A 201046Z SCATSAT IMAGE AND A
201030Z ASCAT-C BULLSEYE IMAGE BOTH SHOW 50 KNOT WINDS OVER THE EAST
QUADRANT OF A DEFINED CIRCULATION. UPPER-LEVEL CONDITIONS REMAIN
FAVORABLE WITH STRONG DIFFLUENCE ALOFT, PARTICULARLY POLEWARD
OUTFLOW, AND LOW TO MODERATE VERTICAL WIND SHEAR. ADDITIONALLY, SST
VALUES (29C) AND HIGH OCEAN HEAT CONTENT VALUES REMAIN CONDUCIVE FOR
FURTHER DEVELOPMENT. TS 02W IS TRACKING WESTWARD UNDER THE STEERING
INFLUENCE OF THE LOW- TO MID-LEVEL SUBTROPICAL RIDGE POSITIONED TO
THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE. THIS FORECAST REMAINS HIGHLY
CONSISTENT WITH THE PREVIOUS JTWC WARNING. THE 34-KNOT WIND RADII
HAVE BEEN ADJUSTED BASED ON A DETAILED ANALYSIS OF RECENT ASCAT
IMAGERY.
B. THROUGH TAU 72, TS 02W IS EXPECTED TO TRACK WESTWARD TO WEST-
NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED STR
ENTRENCHED TO THE NORTH. DUE TO THE VERY FAVORABLE ENVIRONMENTAL
CONDITIONS, THE SYSTEM IS FORECAST TO INTENSIFY RAPIDLY TO 110 KNOTS
BY TAU 72. NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH A
SPREAD OF 150NM AT TAU 72.
C. IN THE EXTENDED PERIOD, UNCERTAINTY INCREASES SIGNIFICANTLY
WITH A BIFURCATION IN THE MODEL GUIDANCE. IN GENERAL, THE SPREAD
REMAINS LARGE AT TAU 120 (400NM). GFS, GFS ENSEMBLE, AFUM, EGRR,
JGSM AND NAVGEM INDICATE A RECURVE SCENARIO WEST OF GUAM, WHICH
APPEARS UNLIKELY DUE TO THE LACK OF A DEEP SHORTWAVE TROUGH
(ALTHOUGH THERE IS A WEAK MIDLATITUDE SHORTWAVE TROUGH PRESENT WELL
TO THE NORTH, OVER AND EAST OF MAINLAND JAPAN). GFS AND NAVGEM
CONTINUE TO ERRONEOUSLY DRIVE THE SYSTEM DIRECTLY INTO AND THROUGH A
STRONG STR POSITIONED OVER GUAM. ECMWF REMAINS THE SOLE OUTLIER BUT
PRESENTS A MORE REALISTIC, CONSISTENT SOLUTION WITH A STAIR-STEP
PATTERN AFTER TAU 120 AND EVENTUAL TRACK TOWARD THE WEST. THE JTWC
OFFICIAL FORECAST FAVORS A NON-RECURVE SCENARIO CLOSER TO THE ECMWF
SOLUTION DUE TO THE LACK OF A MIDLATITUDE RECURVE MECHANISM (DEEP
SHORTWAVE TROUGH AND ASSOCIATED FRONTAL SYSTEM), AND PRESENCE OF A
STRONG STR. TS 02W IS FORECAST TO MAINTAIN INTENSITY AT 105 KNOTS AS
IT SKIRTS WEST OF GUAM, AND MAY STILL PRODUCE GALE-FORCE SUSTAINED
WINDS AND ISOLATED GUSTS NEAR 50 KNOTS OVER GUAM. OVERALL,
CONFIDENCE REMAINS LOW DUE TO THE BIFURCATION IN THE NUMERICAL
GUIDANCE.//
NNNN
TS #WUTIP #02W
This system is currently analysed as a 55knots TS.
WARNING 6/JTWC
Click on the TC graphic to read the Remarks for Warning 6 .
Satellite bulletins are to be found in the comments of this post on JTWC BIS.
As of 12:00 UTC Feb 20, 2019:
Location: 5.3°N 152.5°E
Maximum Winds: 55 kt (100km/h)
Gusts: 70 kt (130km/h)
Minimum Central Pressure: 991 mb
https://www.facebook.com/groups/1817419381676514/
Cheers,
Patrick Hoareau
WDPN31 PGTW 201500 Click on the TC graphic to read the Remarks for Warning 6 .
Satellite bulletins are to be found in the comments of this post on JTWC BIS.
As of 12:00 UTC Feb 20, 2019:
Location: 5.3°N 152.5°E
Maximum Winds: 55 kt (100km/h)
Gusts: 70 kt (130km/h)
Minimum Central Pressure: 991 mb
https://www.facebook.com/groups/1817419381676514/
Cheers,
Patrick Hoareau
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (WUTIP)
WARNING NR 06//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 02W (WUTIP), LOCATED APPROXIMATELY 675 NM
SOUTHEAST OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 11 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A CONSOLIDATING SYSTEM WITH IMPROVED CONVECTIVE
BANDING. A 200759Z WINDSAT 37GHZ IMAGE AND A 201119Z MHS 89GHZ
MICROWAVE IMAGE INDICATE DEEP CONVECTIVE BANDING WRAPPING INTO A
DEFINED LOW-LEVEL CIRCULATION CENTER, WHICH SUPPORTS THE INITIAL
POSITION WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT
55 KNOTS BASED ON A DVORAK INTENSITY ESTIMATE OF T3.5 (55 KNOTS)
FROM PGTW AND RJTD. ADDITIONALLY, A 201046Z SCATSAT IMAGE AND A
201030Z ASCAT-C BULLSEYE IMAGE BOTH SHOW 50 KNOT WINDS OVER THE EAST
QUADRANT OF A DEFINED CIRCULATION. UPPER-LEVEL CONDITIONS REMAIN
FAVORABLE WITH STRONG DIFFLUENCE ALOFT, PARTICULARLY POLEWARD
OUTFLOW, AND LOW TO MODERATE VERTICAL WIND SHEAR. ADDITIONALLY, SST
VALUES (29C) AND HIGH OCEAN HEAT CONTENT VALUES REMAIN CONDUCIVE FOR
FURTHER DEVELOPMENT. TS 02W IS TRACKING WESTWARD UNDER THE STEERING
INFLUENCE OF THE LOW- TO MID-LEVEL SUBTROPICAL RIDGE POSITIONED TO
THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE. THIS FORECAST REMAINS HIGHLY
CONSISTENT WITH THE PREVIOUS JTWC WARNING. THE 34-KNOT WIND RADII
HAVE BEEN ADJUSTED BASED ON A DETAILED ANALYSIS OF RECENT ASCAT
IMAGERY.
B. THROUGH TAU 72, TS 02W IS EXPECTED TO TRACK WESTWARD TO WEST-
NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED STR
ENTRENCHED TO THE NORTH. DUE TO THE VERY FAVORABLE ENVIRONMENTAL
CONDITIONS, THE SYSTEM IS FORECAST TO INTENSIFY RAPIDLY TO 110 KNOTS
BY TAU 72. NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH A
SPREAD OF 150NM AT TAU 72.
C. IN THE EXTENDED PERIOD, UNCERTAINTY INCREASES SIGNIFICANTLY
WITH A BIFURCATION IN THE MODEL GUIDANCE. IN GENERAL, THE SPREAD
REMAINS LARGE AT TAU 120 (400NM). GFS, GFS ENSEMBLE, AFUM, EGRR,
JGSM AND NAVGEM INDICATE A RECURVE SCENARIO WEST OF GUAM, WHICH
APPEARS UNLIKELY DUE TO THE LACK OF A DEEP SHORTWAVE TROUGH
(ALTHOUGH THERE IS A WEAK MIDLATITUDE SHORTWAVE TROUGH PRESENT WELL
TO THE NORTH, OVER AND EAST OF MAINLAND JAPAN). GFS AND NAVGEM
CONTINUE TO ERRONEOUSLY DRIVE THE SYSTEM DIRECTLY INTO AND THROUGH A
STRONG STR POSITIONED OVER GUAM. ECMWF REMAINS THE SOLE OUTLIER BUT
PRESENTS A MORE REALISTIC, CONSISTENT SOLUTION WITH A STAIR-STEP
PATTERN AFTER TAU 120 AND EVENTUAL TRACK TOWARD THE WEST. THE JTWC
OFFICIAL FORECAST FAVORS A NON-RECURVE SCENARIO CLOSER TO THE ECMWF
SOLUTION DUE TO THE LACK OF A MIDLATITUDE RECURVE MECHANISM (DEEP
SHORTWAVE TROUGH AND ASSOCIATED FRONTAL SYSTEM), AND PRESENCE OF A
STRONG STR. TS 02W IS FORECAST TO MAINTAIN INTENSITY AT 105 KNOTS AS
IT SKIRTS WEST OF GUAM, AND MAY STILL PRODUCE GALE-FORCE SUSTAINED
WINDS AND ISOLATED GUSTS NEAR 50 KNOTS OVER GUAM. OVERALL,
CONFIDENCE REMAINS LOW DUE TO THE BIFURCATION IN THE NUMERICAL
GUIDANCE.//
NNNN
1330UTC
1050UTC
1046UTC
