WPAC: PEIPAH - Tropical Storm

[euro6208]

It's sheared and most of the cloud cover is west and southwest of the center, right over the Marianas, where numerous rains are occurring. It is literally drenching. 4-8 inches possible during tomorrow afternoon for the Marianas with 1 to 3 inches have already fallen on northern and central Guam. Already 3.47 inches measured at NWS.

Flash flood watch may be upgraded to a Warning later as more inbound heavy rains are coming in from the WNW as seen from radar.

[1900hurricane]

 https://twitter.com/1900hurricane/status/1173058852222328838

[euro6208]

A record 6.65 inches of rain was recorded today at NWS, eclipsing the old record of 2.26 inch set in 1983. Many parts of Guam getting over 6 inches.

Many area flooded.

More on the way.

[euro6208]

WDPN31 PGTW 150300 COR
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 17W (SEVENTEEN)
WARNING NR 02A CORRECTED//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 17W (SEVENTEEN), LOCATED APPROXIMATELY
226 NM EAST OF SAIPAN, HAS TRACKED NORTHWESTWARD AT 11 KNOTS (KTS)
OVER THE PAST SIX HOURS. AN EXPOSED LOW LEVEL CIRCULATION CENTER
(LLCC) IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY PROVIDES HIGH
CONFIDENCE IN THE INITIAL POSITION. AT 25 KTS, THE INITIAL INTENSITY
IS CONSISTENT WITH THE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF
T1.0 (25 KTS) AND A PARTIAL 142318Z METOP-A ASCAT IMAGE THAT SHOWED
25 KTS TO THE EAST OF THE INITIAL POSITION. STRONG (40-50 KT)
VERTICAL WIND SHEAR (VWS) IS OFFSETTING EXCELLENT EQUATORWARD
OUTFLOW AND WARM (30-31 CELSIUS) SEA SURFACE TEMPERATURE (SST) TO
MAKE THE ENVIRONMENT UNFAVORABLE. TD 17W IS TRACKING ALONG THE
SOUTHWESTERN PERIPHERY OF A SHALLOW, NORTHWEST-TO-SOUTHEAST ORIENTED
SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. FOR THE DURATION OF THE FORECAST, TD 17W WILL TRACK
NORTHWESTWARD ALONG THE PERIPHERY OF THE STR. THE UNFAVORABLE
ENVIRONMENT IS EXPECTED TO KEEP INTENSITY TO 30 KTS OR LESS UNTIL
THE SYSTEM DISSIPATES BY TAU 48. THE INTENSITY FORECAST IS
CONSISTENT WITH AVAILABLE INTENSITY AIDS. NUMERICAL MODEL GUIDANCE
IS IN FAIR AGREEMENT WITH MINOR DIFFERENCES IN ALONG TRACK SPEED.
THE JTWC TRACK FORECAST CLOSELY FOLLOWS CONSENSUS WITH FAIR
CONFIDENCE BASED ON THE MODEL GUIDANCE.
4. JUSTIFICATION FOR CORRECTION: FIXED NUMBER SERIES IN MANOP
HEADER.//
NNNN

[euro6208]

WDPN31 PGTW 150900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 17W (SEVENTEEN)
WARNING NR 03//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 17W (SEVENTEEN), LOCATED APPROXIMATELY
651 NM SOUTHEAST OF IWO TO, JAPAN, HAS TRACKED NORTHWESTWARD AT 13
KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL IMAGERY
SHOWS A FULLY-EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) TRACKING
NORTHWARD, PROVIDING HIGH CONFIDENCE IN THE INITIAL POSITION. A
142359Z METOP-C ASCAT IMAGE DISPLAYS AN AREA OF 30 KNOT WINDS NEAR
THE LLCC, WHICH LENDS HIGH CONFIDENCE TO THE INITIAL INTENSITY OF 30
KNOTS. DESPITE STRONG EQUATORWARD OUTFLOW AND HIGH (30-31 CELSIUS)
SEA SURFACE TEMPERTURE (SST), TD 17W REMAINS IN AN UNFAVORABLE
ENVIRONMENT CHARACTERIZED BY HIGH (25-40 KNOTS) VERTICAL WIND SHEAR
(VWS). TD 17W CONTINUES TO TRACK AROUND THE SOUTHWESTERN PERIPHERY
OF A SHALLOW, NORTH-TO-SOUTH ORIENTED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. FOR THE DURATION OF THE FORECAST, TD 17W WILL TRACK
NORTHWESTWARD ALONG THE STR. THE ENVIRONMENT IS EXPECTED TO REMAIN
UNFAVORABLE FOR FURTHER INTENSIFICATION AS VWS VALUES PERSIST AT
40-50 KNOTS, SHEARING THE SYSTEM UNTIL DISSIPATION AROUND TAU 48.
WITH MINOR DIFFERENCES IN ALONG TRACK SPEED, NUMERICAL GUIDANCE IS IN
FAIR AGREEMENT, PLACING FAIR CONFIDENCE IN THE JTWC TRACK FORECAST
WHICH IS LAID CLOSE TO CONSENSUS.//
NNNN

[euro6208]

This is unexpected.

17W SEVENTEEN 190915 1200 17.8N 147.9E WPAC 35 999

[euro6208]

JMA upgrades to Peipah.

[1900hurricane]

Looks like a clear ASCAT upgrade from the agencies.

[1900hurricane]

Oof.

[euro6208]

WDPN31 PGTW 160300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 17W (PEIPAH)
WARNING NR 06//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 17W (PEIPAH), LOCATED APPROXIMATELY 301
NM SOUTHEAST OF IWO TO, HAS TRACKED NORTHWESTWARD AT 23 KNOTS (KTS)
OVER THE PAST SIX HOURS. THE FULLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC) IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY PROVIDES
HIGH CONFIDENCE IN THE INITIAL POSITION. A PARTIAL 152256Z METOP-A
ASCAT PASS JUST MISSED THE LLCC BUT IT DOES SHOW 30 KT WINDS TO THE
EAST OF THE LLCC. THE INITIAL INTENSITY OF 30 KTS IS BASED ON THE
ASCAT PASS AND MULTI-AGENCY DVORAK ESTIMATES OF T1.5 (25 KTS). THE
ENVIRONMENT IS HOSTILE, DESPITE STRONG EQUATORWARD OUTFLOW AND WARM
(29-30 CELSIUS) SEA SURFACE TEMPERATURE (SST), DUE TO HIGH (35-40
KT) VERTICAL WIND SHEAR. TD 17W IS TRACKING ALONG THE SOUTHERN
PERIPHERY OF A NORTH-SOUTH ORIENTED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. FOR THE DURATION OF THE FORECAST, TD 17W WILL TRACK NORTH-
NORTHWESTWARD ALONG THE PERIPHERY OF THE STR. THE HOSTILE
ENVIRONMENT WILL CAUSE DISSIPATION BETWEEN TAU 24 AND 36. THE
FORECAST TRACK CLOSELY FOLLOWS THE CONSENSUS WITH FAIR CONFIDENCE
BASED ON DECENT AGREEMENT IN THE MODEL GUIDANCE.//
NNNN

[euro6208]

WTPN31 PGTW 161500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL DEPRESSION 17W (PEIPAH) WARNING NR 008//
RMKS/
1. TROPICAL DEPRESSION 17W (PEIPAH) WARNING NR 008
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
161200Z --- NEAR 24.8N 142.8E
MOVEMENT PAST SIX HOURS - 310 DEGREES AT 13 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
REPEAT POSIT: 24.8N 142.8E
---
FORECASTS:
12 HRS, VALID AT:
170000Z --- 27.9N 142.0E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 000 DEG/ 13 KTS
---
24 HRS, VALID AT:
171200Z --- 30.4N 142.1E
MAX SUSTAINED WINDS - 015 KT, GUSTS 025 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
161500Z POSITION NEAR 25.6N 142.6E.
16SEP19. TROPICAL DEPRESSION (TD) 17W (PEIPAH), LOCATED APPROXIMATELY
82 NM EAST OF IWO TO, HAS TRACKED NORTHWESTWARD AT 13 KNOTS (KTS)
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) IMAGERY
SHOWS AN ELONGATED CIRCULATION LOCATED TO THE NORTHEAST OF FLARING
CONVECTION, WHICH HAS BEEN SIGNIFICANTLY SHEARED TO THE SOUTHWEST.
THE EIR IMAGERY, ALONG WITH A 161121Z AMSU 89 GHZ MICROWAVE IMAGE AND
161123Z METOP-B ASCAT PASS, SUPPORT HIGH CONFIDENCE IN THE INITIAL
POSITION PLACEMENT. THE AFOREMENTIONED ASCAT DEPICTS AN AREA OF 20-25
KT WINDS TO THE EAST OF THE CIRCULATION, PLACING HIGH CONFIDENCE IN
THE INITIAL INTENSITY (25 KTS). TD 17W REMAINS IN AN AREA OF WARM
(28-29 CELSIUS) SEA SURFACE TEMPERATURE (SST). HOWEVER, UPPER-LEVEL
ANALYSIS SHOWS A HIGHLY UNFAVORABLE ENVIRONMENT OF HIGH (40-50 KNOTS)
VERTICAL WIND SHEAR AND DECREASING DIVERGENCE ALOFT. TD 17W IS
TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A NORTH-SOUTH ORIENTED
SUBTROPICAL RIDGE (STR) AND WILL SHIFT TO A NORTHWARD TRACK AT TAU
12, TRANSITING ALONG THE WESTERN PERIPHERY OF THE STR FOR THE
REMAINDER OF THE FORECAST. DISSIPATION WILL OCCUR BY TAU 24 DUE TO
LACK OF ENVIRONMENTAL SUPPORT. THE JTWC FORECAST TRACK CLOSELY
FOLLOWS MODEL CONSENSUS AS MODELS ARE IN GOOD AGREEMENT, LENDING GOOD
CONFIDENCE TO THE JTWC TRACK. THIS IS THE FINAL WARNING ON THIS
SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL
BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 161200Z IS 8 FEET.//
NNNN