WPAC: JELAWAT - Post-Tropical

[euro6208]

96W INVEST 180316 0600 7.0N 158.0E WPAC 15 NA

[euro6208]

[euro6208]

000
WWPQ80 PGUM 160422
SPSPQ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TIYAN GU
221 PM ChST Fri Mar 16 2018

PMZ173-174-162300-
POHNPEI-KOSRAE-
221 PM ChST Fri Mar 16 2018

...HEAVY RAIN ACROSS POHNPEI AND KOSRAE STATES THROUGH TONIGHT...

A BROAD TROPICAL DISTURBANCE IS CENTERED NEAR POHNPEI ISLAND AT
7N158E THIS AFTERNOON. FAVORABLE UPPER-LEVEL DYNAMICS WILL CONTINUE
TO TRIGGER WIDESPREAD DEEP CONVECTION NEAR THIS SYSTEM ACROSS
KOSRAE...POHNPEI AND NEARBY ISLANDS/ATOLLS THROUGH TONIGHT.

NEARLY SEVEN INCHES OF RAIN HAVE FALLEN ACROSS POHNPEI AND KOSRAE FOR
THE PAST 9 HOURS. ADDITIONAL RAINFALL OF 3 TO 5 INCHES IS PROBABLE
THROUGH TONIGHT. THIS WILL LIKELY CAUSE WIDESPREAD FLOODING ACROSS
POOR-DRAINAGE AND LOW-LYING AREAS ON KOSRAE...POHNPEI AND NEARBY
ISLANDS/ATOLLS. THE POTENTIAL FOR FLASH FLOODS AND MUDSLIDES NEAR
VALLEYS AND SLOPES FOR POHNPEI AND KOSRAE ISLANDS WILL ALSO INCREASE
SIGNIFICANTLY.

RESIDENTS ON THESE ISLANDS/ATOLLS NEED TO MONITOR THIS SITUATION
CLOSELY AND LISTEN TO INSTRUCTIONS AND UPDATES FROM THEIR LOCAL
EMERGENCY MANAGEMENT AND WEATHER SERVICE OFFICES.

$$

CHAN

[euro6208]

AN AREA OF CONVECTION (INVEST 96W) HAS PERSISTED NEAR 7.3N
156.6E, APPROXIMATELY 100 NM WEST-NORTHWEST OF POHNPEI. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY AND A 161652Z SSMIS PARTIAL
MICROWAVE IMAGE DEPICT FLARING CONVECTION WRAPPING INTO A
CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC). THE UPPER LEVEL
ENVIRONMENT IS CHARACTERIZED BY LOW (10-15 KNOT) AND DECREASING
VERTICAL WIND SHEAR, WITH STRONG DIVERGENCE ALOFT. SEA SURFACE
TEMPERATURES ARE WARM (29-30 CELSIUS) SUPPORTIVE FOR FURTHER
DEVELOPMENT. HOWEVER, GLOBAL DYNAMIC MODELS MAINTAIN A WEAK
CIRCULATION OR TROPICAL WAVE MOVING ON A SLOW NORTHWESTWARD TRACK
WITH THE POSSIBILITY OF SHORT TERM DEVELOPMENT INTO A TROPICAL
DEPRESSION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15
TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM.

[euro6208]

[euro6208]

Already 15 inches recorded so far in Pohnpei.

Pohnpei...Heavy rain persisted overnight with over 5 inches measured
in a 3-hr period. This brings the 24-hr rainfall at the Pohnpei
Weather Office to nearly 15 inches. Rain, torrential at times,
continues to fall this morning with IR satellite animation showing
deep convection again over the island. A tropical disturbance
remains situated just west of Pohnpei near 7N157E, which has been
the main focus of weather in the region the last few days. Overnight
satellite animation shows a convective cluster has persisted all
night, nearly confined within the Pohnpei Coastal Marine Zone. The
Special Weather Statement has been updated to detail the ongoing
situation and the high threat of flash floods and mudslides at
Pohnpei and Kosrae. Convection should taper today, going into a
lull, but a wet pattern will continue at least through tonight.
Based on current satellite trends, it is not out of the question
to expect another 4 to 7 inches of rain today on top of the 5 inches
that fell earlier this morning. The tropical disturbance will
remain nearly stationary at least through the weekend holding the
wet, unsettled weather pattern in place into early next week. Expect
combined seas of 6 to 8 feet through tonight, with seas particularly
choppy and elevated along southern reefs/exposures due to moderate
to fresh south to southeast winds. Residents across Pohnpei State,
particularly on the mountainous islands or those living near streams
and rivers need to monitor this situation closely and heed
instructions and updates from their local emergency management and
weather service offices.

[euro6208]

[euro6208]

TXPQ22 KNES 162121
TCSWNP

A. TROPICAL DISTURBANCE (96W)

B. 16/1830Z

C. 7.5N

D. 156.0E

E. THREE/HIMAWARI-8

F. T1.5/1.5/D1.0/24HRS

G. IR/EIR/VIS

H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR
DATA. SHEAR PATTERN CHARACTERIZED BY CIRCULARLY DEFINED CLOUD LINES
WITH THE LLCC GREATER THAN 75 NM FROM A LARGE COLD OVERCAST FOR A
DT=1.5. MET=1.0. PT=1.5. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...LEE

[euro6208]

WTPN21 PGTW 170230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 160 NM RADIUS OF 8.2N 156.2E WITHIN THE NEXT 12 TO 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL
CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO
BE 15 TO 20 KNOTS. METSAT IMAGERY AT 170000Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 7.3N 156.3E. THE SYSTEM IS
MOVING WESTWARD AT 03 KNOTS.
2. REMARKS:
AN AREA OF CONVECTION (INVEST 96W), PREVIOUSLY LOCATED NEAR 7.3N
156.6E, IS NOW LOCATED NEAR 7.3N 156.3E, APPROXIMATELY 115NM WEST OF
POHNPEI. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A CENTRAL
MASS OF CONVECTION WITH FORMATIVE CONVECTIVE BANDS WRAPPING IN TO A
DEFINED LOW LEVEL CIRCULATION CENTER (LLCC). A 162312Z PARTIAL ASCAT
PASS SHOWS 20KT WINDS FLOWING INTO THE LLCC ON THE PERIPHERY OF THE
SYSTEM. UPPER-LEVEL ANALYSIS SHOWS LOW (10-15KT) VERTICAL WIND
SHEAR, ADEQUATE DIVERGENCE ALOFT, AND POLEWARD OUTFLOW ARE
SUPPORTING DEVELOPMENT INTO A WEAK TROPICAL DEPRESSION. SEA SURFACE
TEMPERATURES ARE VERY WARM (29-30 CELSIUS) IN THE EQUATORIAL WESTERN
PACIFIC AND WILL SUPPORT DEVELOPMENT AS WELL. GLOBAL MODELS ARE
CONFLICTED ON WHICH DIRECTION 96W WILL TRAVEL FROM THE ABSENCE OF A
DOMINANT STEERING FEATURE. HOWEVER, EACH SOLUTION INDICATES SOME
DEGREE OF POLEWARD DISPLACEMENT AND EVENTUALLY A SHIFT TO A
NORTHWESTWARD TRACK BEYOND TAU 24. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
180230Z.//
NNNN

[euro6208]

TPPN10 PGTW 170630

A. TROPICAL DISTURBANCE 96W (W OF POHNPEI)

B. 17/0600Z

C. 7.54N

D. 154.44E

E. FIVE/HMWRI8

F. T1.0/1.5 STT: W0.5/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. .25 WRAP ON LOG10 SPIRAL YIELDS
1.0 DT. MET/PT 1.0. DBO DT.

I. ADDITIONAL POSITIONS: NONE


DAVIS

TXPQ22 KNES 170308
TCSWNP

A. TROPICAL DISTURBANCE (96W)

B. 17/0230Z

C. 7.5N

D. 156.4E

E. THREE/HIMAWARI-8

F. T1.0/1.5/D1.0/24HRS

G. IR/EIR/VIS

H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR
DATA. CURVED BANDING WRAPS .25 FOR DT=1.0. MET AND PT=1.0. FT IS BASED
ON DT.

I. ADDL POSITIONS

NIL


...VELASCO

[euro6208]

WTPN21 PGTW 180230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT REISSUED//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/170221Z MAR 18//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 170230)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
145 NM EITHER SIDE OF A LINE FROM 8.7N 156.2E TO 10.0N 152.5E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 18 TO 23 KNOTS. METSAT
IMAGERY AT 180000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 9.0N 155.8E. THE SYSTEM IS MOVING NORTH-NORTHWESTWARD AT 09
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED
NEAR 7.3N 156.3E, IS NOW LOCATED NEAR 9N 155.8E, APPROXIMATELY 185
NM NORTHWEST OF POHNPEI. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
AND A 172027Z SSMI/S 91GHZ MICROWAVE IMAGE SHOW A MASS OF PERSISTENT
CONVECTION WITH SOME ASSOCIATED FLARING CONVECTION ABOVE A PARTIALLY
EXPOSED LOW LEVEL CIRCULATION CENTER. VERTICAL WIND SHEAR (VWS) IS
IN THE MODERATE RANGE (15-20KTS) BUT THE REGION OF FAVORABLY LOW VWS
IS EXPANDING. INVEST 96W IS TAPPING INTO AN UPPER LEVEL RIDGE,
ENABLING ADEQUATE DIVERGENCE ALOFT. SEA SURFACE TEMPERATURES REMAIN
WARM (28-30 CELSIUS) IN THIS PORTION OF THE EQUATORIAL PACIFIC.
GLOBAL MODELS INDICATE AGREE ON THE POSSIBILITY OF DEVELOPMENT TO
TROPICAL DEPRESSION STRENGTH (25KTS) IN THE NEXT 24 HOURS AS THE
SYSTEM TRACKS NORTHWEST BEFORE TURNING SOUTHWEST IN THE MID TERM.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH. THIS SUPERSEDES REF A.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
190230Z.//
NNNN

[euro6208]

The Marianas remain in the firm grip of a fry trade-wind regime...
for now. Toward the end of this week, the weather could get
interesting if the invest area near Pohnpei tracks a little farther
north than is currently anticipated. This is the cause of the
scattered showers entered Thursday night through Friday night. So,
if it is starting to look like a clean miss, those will most likely
disappear from the forecast. It is expected to pass south of Guam,
the key questions are, how far south, and at what intensity. The
Global Ensemble Forecast System keeps it the weakest, while the Fleet
Ensemble NWP System stregthens it the most. However, it appears likely
to top out as a tropical storm no matter which scenario one might
choose. Afterward, it will likely be back to the dry season trade
winds for a while.

Model consensus tracks 96W west-northwestward over the
next couple days, passing it just north Chuuk Monday night and
Tuesday. Due to mid-level shear last night and this morning, deep
convection near 96W has weakened considerably. However latest
sounding data from Pohnpei reveal shear has decreased and deep
convection is firing up again near the center. With its surface to
mid-level structure still intact, 96W could gradually consolidate
over the next couple of days.

[1900hurricane]

I don't think the TCFA is warranted.

[StruThiO]

Yeah, the TCFA is gone

WTPN21 PGTW 181430
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT CANCELLATION//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/180221ZMAR2018//
AMPN/REF A IS TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. REMARKS: THIS CANCELS REF A (WTPN21 PGTW 180230). THE AREA OF
CONVECTION (INVEST 96W) PREVIOUSLY LOCATED NEAR 9.0N 155.8E, IS NOW
LOCATED NEAR 6.8N 156.4E, APPROXIMATELY 108 NM WEST OF POHNPEI.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS AN ELONGATED
LOW LEVEL CIRCULATION WITH CONVECTION FLARING TO THE NORTH AND EAST
OF THE CENTER, AND MOST OF THE DEFINED TURNING IN THE MID LEVELS. AN
180739Z SSMIS 91GHZ MICROWAVE IMAGE DEPICTS AN ELONGATED CIRCULATION
WITH WEAK BANDING AROUND THE PERIPHERY AND AN AREA OF DEEP
CONVECTION DISPLACED WELL TO THE NORTH, HOWEVER, WHEN VIEWING THE
180739Z SSMIS 91GHZ COLOR COMPOSITE IMAGE THE SYSTEM IS SHOWN AS
VERY BROAD AND WAVE-LIKE IN APPEARANCE, AND NOT SHOWING A DEFINED
LOW LEVEL SYSTEM. AN 181038Z ASCAT PASS DIRECTLY OVER THE LLCC
DEPICTS A VERY WEAK (5-10 KNOT) AND ELONGATED CIRCULATION WITH
HIGHER WINDS LOCATED WELL TO THE NORTH. THE DISTURBANCE IS CURRENTLY
LOCATED IN A FAVORABLE ENVIRONMENT WITH GOOD POLEWARD DIVERGENCE,
LOW VERTICAL WIND SHEAR (5-15 KNOTS), AND WARM SEA SURFACE
TEMPERATURES (29-31 CELSIUS). GLOBAL MODELS SHOW THAT THE SYSTEM
WILL TRACK TO THE WEST-SOUTHWEST BUT ARE NOT IN GOOD AGREEMENT ON
THE TIMING OF ITS MOVEMENT, WITH SOME MODELS DEPICTING QUASI-
STATIONARY MOVEMENT IN THE EARLY TAUS BEFORE HEADING WEST-SOUTHWEST.
ALTHOUGH GLOBAL MODELS HAD BEEN PREVIOUSLY INDICATING CONSOLIDATION
THEY HAVE BACKED OFF AND NOW NO MODELS ARE SHOWING INTENSIFICATION
TO TROPICAL DEPRESSION STRENGTH. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1006 MB. IN VIEW OF THE WEAK CONVECTIVE STRUCTURE AND
RECENT ASCAT PASS, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS DOWNGRADED
TO MEDIUM.//
NNNN

[euro6208]

Our 2 best models keep it alive 10 days from now. EURO has a strong LPA moving through the area with no significant intensification whereas GFS bottoms it out at 978mb

[euro6208]

96W INVEST 180320 0000 8.6N 150.5E WPAC 20 1006

[euro6208]

THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED
NEAR 8.6N 150.5E IS NOW LOCATED NEAR 8.5N 148.5E, APPROXIMATELY 211
NM WEST-NORTHWEST OF CHUUK. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A FULLY EXPOSED, BROAD LOW LEVEL CIRCULATION CENTER (LLCC)
WITH WEAK, ISOLATED CONVECTION OVER THE EASTERN QUADRANT. A 192349Z
89GHZ AMSU-B MICROWAVE IMAGE DEPICTS SHALLOW BANDING WRAPPING INTO
AN ELONGATED LLCC. A RECENT ASCAT PASS CONTINUES TO INDICATE 15-20
KNOT EASTERLY, CONVERGENT WINDS OVER THE NORTHERN SEMICIRCLE. THE
DISTURBANCE IS CURRENTLY LOCATED IN AN AREA OF WEAK DIVERGENCE
ALOFT, LOW TO MODERATE VERTICAL WIND SHEAR (10-20 KNOTS), AND WARM
SEA SURFACE TEMPERATURES (29-31 CELSIUS). GLOBAL MODELS INDICATE THE
SYSTEM WILL TRACK IN A SOUTHWARD TRAJECTORY OVER THE NEXT 48 HOURS
WITH GRADUAL WEAKENING. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1006 MB. DUE TO THE PERSISTENT 15-20 KNOT EASTERLY WINDS
OVER THE NORTHERN SEMICIRCLE AND FLARING DEEP CONVECTION NEAR THE
LLCC, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.

[euro6208]

Much stronger on the 06z run.

[NotoSans]

GFS now going crazy while EC starts supporting developing.

[euro6208]

THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED
NEAR 8.5N 148.5E, IS NOW LOCATED NEAR 5.7N 147.8E, APPROXIMATELY 261
NM SOUTHWEST OF CHUUK. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND
A 210011Z AMSU METOP-A 89GHZ PARTIAL IMAGE DEPICT AN EXPOSED AND
BROAD LOW LEVEL CIRCULATION (LLC) WITH ISOLATED CONVECTION. UPPER
LEVEL ANALYSIS INDICATES THAT THE DISTURBANCE IS IN AN AREA OF
FAVORABLE, LOW (10-15 KNOT) VERTICAL WIND SHEAR WITH WEAK DUAL
DIVERGENCE ALOFT. WARM SEA SURFACE TEMPERATURES (29-31 CELSIUS) WILL
CONTINUE TO SUPPORT 96W OVER THE NEXT 48 HOURS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS REMAINS MEDIUM.