CPAC: IUNE - Post-Tropical

[cycloneye]

TROPICAL DEPRESSION TWO-C DISCUSSION NUMBER 6
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022015
500 AM HST SAT JUL 11 2015

IT CONTINUES TO BE VERY DIFFICULT TO LOCATE THE LOW-LEVEL
CIRCULATION CENTER...LLCC...OF TROPICAL DEPRESSION TWO-C USING
INFRARED SATELLITE IMAGERY EARLY THIS MORNING. THERE WAS AN ASCAT
PASS OVER THE SYSTEM AROUND 0718Z WHICH CONFIRMED THE LLCC WAS
DISPLACED TO THE SOUTHEAST OF THE PULSING DEEP CONVECTION. THIS
ASCAT PASS ALSO SHOWED AN AREA OF 25 TO 30 KT WINDS SPREAD OVER MOST
OF THE NORTHEASTERN SEMICIRCLE OF TWO-C. THIS DISPLACEMENT BETWEEN
THE LLCC AND THE ASSOCIATED THUNDERSTORMS IS ALSO SUPPORTED BY THE
MOST RECENT ESTIMATES OF ENVIRONMENTAL VERTICAL WIND SHEAR OF 08 KT
FROM 135 DEGREES BASED ON THE UW-CIMSS ANALYSIS. AS A RESULT OF THIS
SHEAR...MOST OF THE FIX AGENCIES APPEAR TO BE FOLLOWING THE AREA OF
DEEP CONVECTION. THE MOST RECENT DVORAK CURRENT INTENSITY ESTIMATE
FROM HFO WAS AN UNREALISTIC 3.0...SAB WAS 2.0...AND JTWC WAS 1.5.
THE INITIAL INTENSITY WILL BE HELD AT 30 KT...BASED ON THE WIND
OBSERVATIONS FROM THE EARLIER ASCAT PASS...AND THE LACK OF
SIGNIFICANT CHANGES TO THE STRUCTURE OF THE SYSTEM IN SATELLITE
IMAGERY SINCE LAST EVENING.

THE INITIAL MOTION VECTOR OF TWO-C IS 305/09 KT. TWO-C REMAINS IN A
RELATIVELY COMPLEX AND WEAK STEERING ENVIRONMENT. THE NEAR SURFACE
STEERING OF TWO-C APPEARS TO BE INFLUENCED PRIMARILY BY A LOW-LEVEL
TROUGH EXTENDING TOWARD THE REMNANT CIRCULATION OF FORMER TROPICAL
CYCLONE ELA...WHICH IS CAUSING A WEAKNESS IN A RELATIVELY STRONG
SURFACE HIGH LOCATED FAR NORTH OF THE MAIN HAWAIIAN ISLANDS. TWO-C
IS ALSO NEAR A WEAKNESS BETWEEN A MID-LEVEL RIDGE TO THE NORTHEAST
OF THE BIG ISLAND AND A MID-LEVEL TROUGH WEST OF KAUAI. THE PRESENCE
OF THESE FEATURES IS EXPECTED TO MAINTAIN A NORTHWESTWARD MOTION
OVER THE NEXT 12 HOURS OR SO...FOLLOWED BY A TURN TOWARD THE WEST AS
DEEP LAYER RIDGING EVENTUALLY BUILDS TO THE NORTH OF TWO-C. THE
LATEST OFFICIAL FORECAST FOLLOWS THE PREVIOUS TRACK CLOSELY WITH
ONLY A FEW MINOR ADJUSTMENTS THROUGH 48 HOURS. THE NEW FORECAST FOR
DAYS 3 THROUGH 5 IS NOW SHIFTED SLIGHTLY TOWARDS THE LEFT AT A
SOMEWHAT SLOWER FORWARD SPEED. THEREFORE...THIS LATEST FORECAST
TRACK IS CLOSE TO THE DYNAMIC AND CONSENSUS MODEL ENVELOPE THROUGH
48 HOURS...WHILE IT REMAINS TO THE NORTH OF THE ENVELOPE WHEN THE
SPREAD OF THE MODEL GUIDANCE INCREASES.

SOME SLOW INTENSIFICATION OF THE DEPRESSION IS FORECAST AS THE RIDGE
ALOFT IS EXPECTED TO REMAIN NORTH OF TWO-C...WHICH WILL LIKELY
MAINTAIN MODEST EAST TO SOUTHEAST VERTICAL WIND SHEAR OF 5 TO 10 KT.
THE RELATIVELY SMALL SIZE OF TWO-C IS LIKELY LEADING TO A LARGE
SPREAD IN THE INTENSITY GUIDANCE DUE TO SENSITIVITY OF THE
RELATIVELY SMALL SYSTEM TO EVEN THE MODEST VERTICAL WIND SHEAR THAT
IS CURRENTLY IN THE AREA. THE LATEST INTENSITY FORECAST CLOSELY
FOLLOWS THE PREVIOUS ADVISORY. SHIPS HAS BEEN THE MOST AGGRESSIVE
INTENSITY GUIDANCE...WITH OTHER MODEL OUTPUT KEEPING TWO-C A
DEPRESSION OR FORECASTING IT TO DISSIPATE WITHIN 3 TO 5 DAYS.

FORECAST POSITIONS AND MAX WINDS

INIT 11/1500Z 13.9N 157.0W 30 KT 35 MPH
12H 12/0000Z 14.4N 158.3W 30 KT 35 MPH
24H 12/1200Z 14.5N 159.9W 35 KT 40 MPH
36H 13/0000Z 14.3N 161.6W 35 KT 40 MPH
48H 13/1200Z 14.2N 163.4W 40 KT 45 MPH
72H 14/1200Z 13.5N 167.5W 45 KT 50 MPH
96H 15/1200Z 13.0N 171.5W 50 KT 60 MPH
120H 16/1200Z 13.0N 175.0W 55 KT 65 MPH

$$
FORECASTER HOUSTON

[Hurricane Jed]

TROPICAL STORM IUNE DISCUSSION NUMBER 7
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022015
1100 AM HST SAT JUL 11 2015

THE LOW-LEVEL CIRCULATION CENTER...LLCC...REMAINS HIDDEN UNDER COLD
DEEP CLOUD COVER...SO THE CENTER IS DIFFICULT TO LOCATE USING
VISIBLE OR INFRARED SATELLITE IMAGERY. DVORAK CLASSIFICATIONS FROM
THE FIX AGENCIES RANGED FROM 1.5 TO 2.5 AND THERE WAS A FAIR AMOUNT
OF SPREAD IN THE POSITIONS. FORTUNATELY...A SERIES OF MICROWAVE
PASSES WERE HELPFUL IN LOCATING THE CENTER UNDER THE SOUTHEAST SIDE
OF THE CENTRAL DENSE OVERCAST. SINCE THE COLD CLOUDS HAVE COOLED
AND INCREASED IN AREA OVER THE PAST 24 HOURS AND THE CENTER SEEMS
TO BE EMBEDDED WELL WITHIN THE COLD OVERCAST I DECIDED TO GO WITH
THE HIGHER INTENSITY ESTIMATE AND UPGRADE THE SYSTEM TO TROPICAL
STORM IUNE.

THE INITIAL MOTION VECTOR OF IUNE IS 285/08 KT. THE SYSTEM REMAINS
IN A RELATIVELY COMPLEX AND WEAK STEERING ENVIRONMENT. A TROUGH TO
THE NORTHEAST AND A RIDGE TO THE NORTHWEST HAVE BEEN STEERING IUNE
TOWARD THE NORTHWEST. AS THESE SYSTEMS SHIFT WEST...THE MEAN FLOW
OVER IUNE SHOULD SHIFT OUT OF THE NORTHEAST AND THE TRACK OF THE
STORM SHOULD SHIFT TOWARD THE WEST SOUTHWEST. THE LATEST OFFICIAL
FORECAST FOLLOWS THE PREVIOUS TRACK CLOSELY AND REMAINS CLOSE TO THE
DYNAMIC AND CONSENSUS MODEL ENVELOPE.

LITTLE CHANGE IN INTENSITY IS EXPECTED OVER THE NEXT 48 HOURS AS
IUNE REMAINS OVER MARGINALLY WARM WATER AND MODERATE EAST SOUTHEAST
SHEAR. AS IUNE TURNS TOWARD THE WEST SOUTHWEST IT WILL MOVE OVER
WARMER WATER AND GRADUAL INTENSIFICATION IS EXPECTED.HOWEVER...
THERE IS A RATHER LARGE SPREAD IN THE MODEL GUIDANCE. SINCE IUNE IS
SUCH A SMALL SYSTEM AND THE ENVIRONMENT IS COMPLEX I EXPECT THE
INTENSITY FORECAST TO REMAIN CHALLENGING.



FORECAST POSITIONS AND MAX WINDS

INIT 11/2100Z 14.5N 157.8W 35 KT 40 MPH
12H 12/0600Z 14.8N 159.0W 35 KT 40 MPH
24H 12/1800Z 14.8N 160.7W 35 KT 40 MPH
36H 13/0600Z 14.7N 162.4W 35 KT 40 MPH
48H 13/1800Z 14.0N 164.3W 35 KT 40 MPH
72H 14/1800Z 13.3N 168.4W 45 KT 50 MPH
96H 15/1800Z 13.0N 172.5W 50 KT 60 MPH
120H 16/1800Z 12.5N 175.5W 55 KT 65 MPH

$$
FORECASTER DONALDSON

[Hurricane Jed]

Iune now

[Yellow Evan]

* EAST PACIFIC SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* IUNE CP022015 07/12/15 00 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 35 38 40 42 43 48 54 58 59 61 63 65 64
V (KT) LAND 35 38 40 42 43 48 54 58 59 61 63 65 64
V (KT) LGE mod 35 37 39 41 42 45 48 53 59 66 73 78 82
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 4 5 5 7 9 7 9 6 12 12 16 9 10
SHEAR ADJ (KT) 0 0 0 0 -3 -5 0 -2 -5 -5 -5 -4 -3
SHEAR DIR 128 115 128 119 121 110 102 67 54 48 40 22 350
SST (C) 27.1 27.1 27.1 27.2 27.3 27.5 27.9 28.1 28.0 27.9 28.0 28.1 28.2
POT. INT. (KT) 135 134 134 135 136 139 143 145 144 143 144 144 144
200 MB T (C) -52.3 -52.2 -52.4 -52.5 -52.5 -52.8 -52.8 -53.2 -53.1 -53.1 -52.8 -53.1 -53.3
TH_E DEV (C) 9 10 10 10 10 10 10 10 10 10 10 10 10
700-500 MB RH 59 58 57 56 53 51 52 52 50 51 50 51 49
MODEL VTX (KT) 11 10 10 9 9 8 9 8 6 6 5 5 4
850 MB ENV VOR 32 36 38 41 39 39 46 46 30 29 22 23 17
200 MB DIV 10 6 6 -9 -10 -20 -16 -3 -5 -3 1 -6 -7
700-850 TADV 0 1 2 1 0 0 2 2 1 0 0 -1 -2
LAND (KM) 537 591 652 716 785 909 1107 1267 1411 1591 1798 1944 2044
LAT (DEG N) 15.0 15.0 15.0 15.1 15.1 14.7 13.8 13.5 13.7 13.5 13.0 12.8 12.8
LONG(DEG W) 158.6 159.5 160.3 161.2 162.0 163.8 165.8 167.8 169.9 171.9 173.9 175.4 176.5
STM SPEED (KT) 9 8 8 8 8 10 10 10 10 10 9 6 5
HEAT CONTENT 17 9 7 7 9 28 45 40 37 31 28 52 59

[cycloneye]

TROPICAL STORM IUNE DISCUSSION NUMBER 8
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022015
500 PM HST SAT JUL 11 2015

THE LOW-LEVEL CIRCULATION CENTER...LLCC...REMAINS HIDDEN UNDER COLD
DEEP CLOUD COVER...SO THE CENTER REMAINS DIFFICULT TO LOCATE USING
VISIBLE OR INFRARED SATELLITE IMAGERY. DVORAK CLASSIFICATIONS FROM
THE FIX AGENCIES RANGED FROM 2.0 TO 2.5 AND THERE REMAINS A FAIR
AMOUNT OF SPREAD IN THE POSITIONS. I HAVE POSITIONED THE CENTER
UNDER THE SOUTHEAST SIDE OF THE CENTRAL DENSE OVERCAST. AN 11/1949
UTC ASCAT PASS SHOWED IUNE WITH A SMALL CIRCULATION AND TROPICAL
STORM FORCE WINDS WITHIN 50 MILES NORTHWEST OF THE CENTER. I HAVE
KEPT THE INTENSITY AT 35 KT.

THE INITIAL MOTION VECTOR OF IUNE IS 290/10 KT. THE SYSTEM REMAINS
IN A RELATIVELY COMPLEX AND WEAK STEERING ENVIRONMENT. A LOW ALOFT
TO THE NORTHWEST AND A RIDGE TO THE NORTHEAST HAD BEEN STEERING IUNE
TOWARD THE NORTHWEST. AS THE LOW MOVES NORTH AND WEAKENS AND THE
RIDGE BUILDS SOUTHWESTWARD...THE MEAN FLOW OVER IUNE SHOULD SHIFT
OUT OF THE EAST NORTHEAST AND THE TRACK OF THE STORM SHOULD SHIFT
TOWARD THE WEST SOUTHWEST. THE LATEST OFFICIAL FORECAST FOLLOWS THE
PREVIOUS TRACK CLOSELY AND REMAINS CLOSE TO THE DYNAMIC AND
CONSENSUS MODEL ENVELOPE.

LITTLE CHANGE IN INTENSITY IS EXPECTED OVER THE NEXT 48 HOURS AS
IUNE REMAINS OVER MARGINALLY WARM WATER WITH MODERATE EAST SOUTHEAST
SHEAR. AS IUNE TURNS TOWARD THE WEST SOUTHWEST IT WILL MOVE OVER
WARMER WATER AND GRADUAL INTENSIFICATION IS EXPECTED AFTER 48 HOURS.
HOWEVER...THERE IS A RATHER LARGE SPREAD IN THE MODEL GUIDANCE.
SINCE IUNE IS A SMALL SYSTEM AND THE ENVIRONMENT IS COMPLEX...THE
INTENSITY FORECAST MAY REMAIN CHALLENGING.



FORECAST POSITIONS AND MAX WINDS

INIT 12/0300Z 15.0N 159.1W 35 KT 40 MPH
12H 12/1200Z 15.2N 160.5W 35 KT 40 MPH
24H 13/0000Z 14.9N 162.3W 35 KT 40 MPH
36H 13/1200Z 14.5N 164.0W 35 KT 40 MPH
48H 14/0000Z 14.0N 166.0W 35 KT 40 MPH
72H 15/0000Z 13.0N 170.0W 50 KT 60 MPH
96H 16/0000Z 12.5N 174.0W 55 KT 65 MPH
120H 17/0000Z 12.5N 177.5W 55 KT 65 MPH

$$
FORECASTER DONALDSON

[Yellow Evan]

* EAST PACIFIC SHIPS INTENSITY FORECAST *
* IR SAT DATA AVAILABLE, OHC AVAILABLE *
* IUNE CP022015 07/12/15 06 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
V (KT) NO LAND 35 36 37 38 40 44 48 52 54 56 58 61 62
V (KT) LAND 35 36 37 38 40 44 48 52 54 56 58 61 62
V (KT) LGE mod 35 35 35 36 36 38 41 46 53 60 67 73 80
Storm Type TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP TROP

SHEAR (KT) 5 6 10 10 10 9 6 9 11 14 12 7 4
SHEAR ADJ (KT) 0 0 0 -2 -5 -1 0 -2 -3 -4 -6 -4 0
SHEAR DIR 128 127 120 127 130 103 92 45 67 53 69 31 313
SST (C) 27.1 27.1 27.2 27.3 27.4 27.7 28.0 28.1 28.0 28.0 28.1 28.2 28.3
POT. INT. (KT) 135 135 135 136 137 141 144 145 144 144 145 145 146
200 MB T (C) -52.3 -52.4 -52.5 -52.5 -52.7 -52.9 -52.9 -53.2 -53.0 -53.1 -53.1 -53.3 -53.4
TH_E DEV (C) 10 10 10 11 11 10 10 10 10 10 10 9 10
700-500 MB RH 60 58 58 54 52 53 53 53 54 54 50 50 47
MODEL VTX (KT) 11 10 10 9 8 9 8 7 6 5 5 4 3
850 MB ENV VOR 37 40 38 39 40 42 54 40 38 32 27 20 16
200 MB DIV 4 13 5 3 -4 -35 -11 -12 3 -9 -3 -28 -14
700-850 TADV 2 1 2 2 0 1 3 0 1 0 0 -2 -1
LAND (KM) 562 637 718 805 862 992 1179 1364 1543 1723 1912 2065 2198
LAT (DEG N) 15.3 15.3 15.2 15.0 14.8 14.4 13.8 13.3 12.9 12.7 12.6 12.6 12.7
LONG(DEG W) 159.4 160.4 161.3 162.2 163.0 164.8 166.9 168.9 170.8 172.8 174.9 176.6 178.1
STM SPEED (KT) 9 9 9 8 8 10 10 10 9 10 9 7 8
HEAT CONTENT 9 7 8 10 17 39 40 36 33 25 45 57 53

[cycloneye]

TROPICAL STORM IUNE DISCUSSION NUMBER 9
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022015
1100 PM HST SAT JUL 11 2015

SATELLITE IMAGERY SHOWS CLOUD TOPS ASSOCIATED WITH IUNE HAD
BEEN STEADILY WARMING SINCE THE LAST ADVISORY...BUT NEW AND ISOLATED
THUNDERSTORMS HAVE RECENTLY DEVELOPED WITHIN THE NORTHERN
SEMICIRCLE. MID AND HIGH LEVEL MOISTURE STREAMING NORTHWARD FROM THE
STORM EXTENDS UP TO 1000 MILES AWAY...AND OVER PORTIONS OF THE MAIN
HAWAIIAN ISLANDS. THIS MOISTURE IS GETTING CAUGHT UP IN A DEEP AND
RELATIVELY STRONG SOUTHERLY FLOW ALOFT BETWEEN A CLOSED LOW CENTERED
TO IUNE/S NORTH-NORTHWEST...AND A RIDGE TO THE NORTHEAST. IUNE IS
JUST SOUTH OF THIS AREA OF STRONG SOUTHERLY SHEAR...AND IS AN AREA
OF LIGHT SOUTH TO SOUTHEASTERLY SHEAR...ANALYZED AS BEING 5 KT OR
LESS BY UW-CIMSS AND SHIPS GUIDANCE. A 0330Z AMSU PASS WAS HELPFUL IN
LOCATING THE POORLY ORGANIZED CENTER OF THE STORM...WHICH IS
ESTIMATED TO BE SOUTH OF THE NEWLY-DEVELOPED THUNDERSTORMS.
SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES RANGE FROM 2.0 TO
2.5...AND THE SYSTEM WILL BE MAINTAINED AS A 35 KT TROPICAL STORM
FOR THIS ADVISORY.

THE INITIAL MOTION VECTOR FOR THIS ADVISORY IS 295/10 KT. THE LOW
LEVEL ENVIRONMENT FEATURES A STRONG HIGH FAR TO THE NORTH...BUT
THE REMNANT CIRCULATION OF ELA LOCATED BETWEEN IUNE AND THE HIGH IS
LEADING TO A WEAKNESS IN THE PRESSURE GRADIENT. THE CONTINUED
WEAKENING OF THE ELA REMNANT WILL LEAD TO A TIGHTENING OF THE LOW
LEVEL GRADIENT NORTH OF IUNE OVER THE NEXT COUPLE OF DAYS. ALOFT...
THE FORECAST ANTICIPATES THE NEARBY LOW TO WEAKEN AND MOVE NORTH
WHILE THE RIDGE TO THE NORTHEAST BUILDS SOUTHWEST TOWARD THE STORM.
THESE COMBINED EFFECTS ARE EXPECTED TO INDUCE AN INCREASINGLY
WEST-SOUTHWESTERLY MOTION WITHIN 24 HOURS THAT PERSISTS FOR THE BULK
OF THE FORECAST PERIOD. THE UPDATED OFFICIAL TRACK FORECAST LIES
VERY CLOSE TO THE PREVIOUS FORECAST AND THE TVCN CONSENSUS.

THE INTENSITY FORECAST CONTINUES TO BE PROBLEMATIC AND CONTAINS A
HIGHER THAN NORMAL AMOUNT OF UNCERTAINTY...PARTIALLY DUE TO IUNE/S
SMALL SIZE. SHIPS AND LGEM ARE FORECASTING STEADY INTENSIFICATION TO
NEAR HURRICANE STATUS BY DAY 5. CONVERSELY...THE HWRF AND GFDL
SIGNIFICANTLY WEAKEN THE SYSTEM...AS DO THE GFS AND ECMWF GLOBAL
MODELS...WITH IUNE BARELY MAINTAINING DEPRESSION STATUS. OVER THE
PAST TWO DAYS...SHIPS AND LGEM GUIDANCE HAVE PROVEN TO BE TOO
AGGRESSIVE IN INTENSIFYING THE SYSTEM. THE UPDATED OFFICIAL
INTENSITY FORECAST IS CLOSE TO THE PREVIOUS AND WEAKER THAN
SHIPS/LGEM IN THE EARLY PERIODS...HAS BEEN NUDGED DOWNWARD IN THE
LATER PERIODS...AND IS CLOSE TO THE ICON CONSENSUS THROUGH 72 HOURS.


FORECAST POSITIONS AND MAX WINDS

INIT 12/0900Z 15.4N 159.9W 35 KT 40 MPH
12H 12/1800Z 15.2N 161.3W 35 KT 40 MPH
24H 13/0600Z 14.8N 163.2W 35 KT 40 MPH
36H 13/1800Z 14.4N 165.1W 35 KT 40 MPH
48H 14/0600Z 13.9N 167.1W 35 KT 40 MPH
72H 15/0600Z 13.0N 171.0W 40 KT 45 MPH
96H 16/0600Z 12.5N 175.0W 45 KT 50 MPH
120H 17/0600Z 12.5N 178.0W 45 KT 50 MPH

$$

FORECASTER BIRCHARD

[cycloneye]

TROPICAL STORM IUNE DISCUSSION NUMBER 10
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022015
500 AM HST SUN JUL 12 2015

ALTHOUGH NEW THUNDERSTORMS HAVE DEVELOPED NEAR THE LOW LEVEL
CIRCULATION CENTER /LLCC/ SINCE THE PREVIOUS ADVISORY...THE OVERALL
SATELLITE APPEARANCE OF IUNE IS NOT VERY IMPRESSIVE THIS MORNING...
DESPITE WHAT IS ANALYZED AS VERY LIGHT SHEAR OVER THE SYSTEM. THE
LLCC IS NEARLY COMPLETELY EXPOSED...AND LOCATED TO THE SOUTHEAST OF
THE LIMITED DEEP CONVECTION...WITH BI-SPECTRAL INFRARED IMAGERY /AKA
FOG CHANNEL/ HELPING TO DISCERN LOW CLOUD LINES SPIRALING AROUND THE
CENTER. LATEST SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES RANGE
FROM 25 TO 35 KT...AND THE INITIAL INTENSITY FOR THIS ADVISORY HAS
BEEN MAINTAINED AT WHAT MAY BE A SOMEWHAT GENEROUS 35 KT.

INITIAL MOTION IS JUST SOUTH OF DUE WEST THIS MORNING...ESTIMATED
TO BE 260/08 KT. THE TRACK FORECAST AND PHILOSOPHY HAVE CHANGED
LITTLE SINCE THE PREVIOUS ADVISORY. THE LOW LEVEL ENVIRONMENT
FEATURES A STRONG HIGH FAR TO THE NORTH...BUT THE REMNANT
CIRCULATION OF ELA LOCATED BETWEEN IUNE AND THE HIGH IS LEADING TO A
WEAKNESS IN THE PRESSURE GRADIENT. THE CONTINUED WEAKENING OF THE
ELA REMNANT WILL LEAD TO A TIGHTENING OF THE LOW LEVEL GRADIENT
NORTH OF IUNE OVER THE NEXT COUPLE OF DAYS. ALOFT...THE FORECAST
ANTICIPATES A LOW TO THE NORTH-NORTHWEST OF THE SYSTEM TO WEAKEN AND
LIFT NORTHWARD...WHILE A RIDGE TO THE NORTHEAST BUILDS SOUTHWESTWARD.
THESE COMBINED EFFECTS ARE EXPECTED TO RESULT IN A WEST-
SOUTHWESTERLY MOTION THAT PERSISTS FOR THE BULK OF THE FORECAST
PERIOD. THE UPDATED OFFICIAL TRACK FORECAST LIES VERY CLOSE TO THE
PREVIOUS FORECAST AND THE TVCN CONSENSUS...AND HAS BEEN NUDGED A BIT
NORTHWARD AT THE LATER PERIODS.

WHILE SSTS WILL BE SUFFICIENTLY WARM ALONG THE FORECAST TRACK TO
SUPPORT A STRONG TROPICAL CYCLONE...IUNE IS FORECAST TO WEAKEN...
MAINLY DUE TO MODERATE EASTERLY SHEAR ALLOWING MID-LEVEL DRY AIR TO
BE ENTRAINED INTO THE SMALL AND FRAGILE SYSTEM. THE INTENSITY
GUIDANCE REMAINS SPLIT INTO TWO DISTINCT CAMPS...WITH SHIPS AND LGEM
FORECASTING SLOW BUT STEADY INTENSIFICATION...WHILE GFDL AND HWRF
FORECAST STEADY WEAKENING...WITH DISSIPATION OCCURRING BY DAY 4. THE
IVCN CONSENSUS THEREFORE LIES BETWEEN THESE TWO SOLUTIONS...AND THE
OFFICIAL FORECAST HAS BEEN CLOSE TO THIS CONSENSUS FOR THE PAST
SEVERAL FORECAST CYCLES. THE UPDATED OFFICIAL INTENSITY FORECAST
REPRESENTS A SIGNIFICANT CHANGE FROM THE PREVIOUS...AND NOW MORE
CLOSELY FOLLOWS THE WEAKER GFDL/HWRF SOLUTIONS. THIS IS ALSO
SUPPORTED BY THE NORMALLY RELIABLE GFS AND ECMWF GUIDANCE...WHICH
DEGRADE THE SYSTEM TO AN OPEN WAVE BY DAY 4 OR 5. WHILE THE UPDATED
FORECAST ANTICIPATES THE SYSTEM REMAINING A VIABLE TROPICAL CYCLONE
THROUGH DAY 5...THIS MAY BE GENEROUS...AND THE SYSTEM MAY ACTUALLY
DEGRADE TO A REMNANT LOW BEFORE TAU 120.


FORECAST POSITIONS AND MAX WINDS

INIT 12/1500Z 15.1N 160.5W 35 KT 40 MPH
12H 13/0000Z 14.9N 162.0W 30 KT 35 MPH
24H 13/1200Z 14.4N 164.0W 30 KT 35 MPH
36H 14/0000Z 13.9N 165.9W 30 KT 35 MPH
48H 14/1200Z 13.6N 167.9W 30 KT 35 MPH
72H 15/1200Z 13.5N 172.2W 25 KT 30 MPH
96H 16/1200Z 13.5N 175.5W 25 KT 30 MPH
120H 17/1200Z 13.5N 179.0W 25 KT 30 MPH

$$

FORECASTER BIRCHARD

[cycloneye]

TROPICAL DEPRESSION IUNE DISCUSSION NUMBER 11
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022015
1100 AM HST SUN JUL 12 2015

AFTER LOSING ITS CENTRAL CONVECTION LATE YESTERDAY...IUNE HAS
REMAINED WEAK OVERNIGHT AND THIS MORNING WITH THE ONLY DEEP
CONVECTION OCCURRING WITHIN A PERIPHERAL RAINBAND NORTHWEST OF THE
FULLY EXPOSED LOW LEVEL CIRCULATION CENTER. THE LATEST
SUBJECTIVE DVORAK INTENSITY ESTIMATES RANGED FROM 25 KT TO
35 KTS...WHILE THE UW-CIMSS ADT GIVES A VALUE OF 31 KT. THE INITIAL
INTENSITY FOR THIS PACKAGE WILL BE 30 KT WHICH INDICATES THAT IUNE
HAS WEAKENED TO A TROPICAL DEPRESSION.

THROUGH MOST OF THE LIFE CYCLE OF IUNE THE INTENSITY FORECAST AIDS
HAVE BEEN SPLIT INTO TWO CAMPS WITH THE STATISTICAL
AIDS SUCH AS SHIPS AND LGEM SHOWING STEADY INTENSIFICATION WHILE THE
DYNAMICAL AIDS SUCH AS HWRF AND THE GLOBAL MODELS SHOWING EVENTUAL
DISSIPATION. IT APPEARS THE FORK IN THE ROAD HAS BEEN PASSED AND
OBSERVATIONAL REALITIES INDICATE THAT THE DYNAMICAL MODELS SHOULD BE
HEEDED. IN ADDITION TO THE WEAK DEEP CONVECTION ACTIVITY...MIMIC
TPW DATA SHOW DRIER AIR ENTRAINING INTO THE SYSTEM FROM THE WEST
AND THE GLOBAL MODELS SHOW THAT THIS WILL CONTINUE FOR THE NEXT 12
TO 24 HOURS. WHILE A LARGER...MORE ROBUST SYSTEM WOULD BE ABLE TO
RECOVER...A SCALE-CHALLENGED SYSTEM SUCH AS IUNE IS OFTEN MORE
VULNERABLE TO UNFAVORABLE ENVIRONMENTAL CONDITIONS. THUS...THE
CURRENT FORECAST CONTINUES THE WEAKENING TREND OF THE PREVIOUS
FORECAST PACKAGE BUT MAKES IUNE A POST-TROPICAL REMNANT LOW IN 48
HOURS FOLLOWED BY DISSIPATION IN ABOUT 96 HOURS. THIS IS CONSISTENT
WITH THE DATA FROM THE GFS...ECMWF AND HWRF WHICH ALL SHOW
DISSIPATION AT SOME POINT AFTER 48 HOURS. NOTE THAT IF ASSOCIATED
DEEP CONVECTION COMPLETELY DISSIPATES AND FAILS TO REGENERATE...IUNE
COULD REACH POST-TROPICAL/REMNANT LOW STATUS SOONER THAN CURRENTLY
FORECAST.

THE INITIAL MOTION FOR THIS PACKAGE IS 245/08 KT. A MIDDLE AND UPPER
LEVEL LOW NORTHWEST OF THE MAIN HAWAIIAN ISLANDS IS WEAKENING AND
LIFTING TOWARD THE NORTH. IN ITS PLACE...A NORTHEAST-SOUTHWEST
ORIENTED RIDGE IS BUILDING INTO THE AREA NORTH OF IUNE WHICH IS
IMPARTING A WEST-SOUTHWESTWARD MOTION ON THE SYSTEM. OBJECTIVE
AIDS...AND THE PREVIOUS FORECAST PACKAGE...ARE IN AGREEMENT WITH
THIS SCENARIO WITH THE DYNAMICAL MODEL SOLUTIONS TIGHTLY PACKED.
THE CURRENT FORECAST PACKAGE HAS BEEN NUDGED SLIGHTLY SOUTH OF THE
PREVIOUS PACKAGE AND IS ALIGNED CLOSER TO THE HWRF AND GFS
SOLUTIONS WHICH APPEAR TO BE HANDLING THE SCENARIO WELL.


FORECAST POSITIONS AND MAX WINDS

INIT 12/2100Z 14.7N 161.1W 30 KT 35 MPH
12H 13/0600Z 14.2N 162.5W 30 KT 35 MPH
24H 13/1800Z 13.6N 164.4W 25 KT 30 MPH
36H 14/0600Z 13.2N 166.4W 25 KT 30 MPH
48H 14/1800Z 13.0N 168.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 15/1800Z 13.3N 172.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 16/1800Z 13.5N 176.0W 20 KT 25 MPH...DISSIPATED

$$
FORECASTER KODAMA

[cycloneye]

POST-TROPICAL CYCLONE IUNE DISCUSSION NUMBER 14
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP022015
500 AM HST MON JUL 13 2015

NIGHTTIME CLOUD TOP COOLING HAS ALLOWED SPOTTY DEEP CONVECTION TO
FORM IN PLACES WITHIN THE CIRCULATION OF IUNE...BUT NOT CONSISTENTLY
WITHIN 100 NM OF THE LLCC. SINCE IUNE HAS REMAINED DEVOID OF
ORGANIZED DEEP CONVECTION FOR 18 HOURS...WE HAVE DOWNGRADED THIS
SYSTEM TO A POST TROPICAL REMNANT LOW AND THIS WILL BE THE LAST
DISCUSSION FOR IT.

THE ONLY SATELLITE CENTER CONTINUING TO PROVIDE SUBJECTIVE DVORAK
SATELLITE INTENSITY ESTIMATES IS PHFO...WITH A 1.0 BASED ON MODEL
EXPECTED T. THE FINAL INITIAL INTENSITY FOR THIS SYSTEM IS THEREFORE
SET AT 25 KT. IUNE HAS SUFFERED FROM AN INFLUX OF DRIER AIR
ENTRAINED THROUGH ITS NORTHWEST...SOUTHWEST AND SOUTHEAST QUADRANTS
ALONG WITH DECREASING DIVERGENCE ALOFT. THESE EFFECTS HAVE COUNTERED
THOSE OF AN OTHERWISE FAVORABLE ENVIRONMENT...LIKE LOW SHEAR. FOR
COMPLETENESS...IT SHOULD BE NOTED THAT SHIPS WANTS TO KEEP IUNE
CHUGGING ALONG AS A TROPICAL DEPRESSION BASED MAINLY ON FRIENDLY
SSTS AND OCEAN HEAT CONTENT. SHIPS ALSO SEES UPPER DIVERGENCE
BECOMING MILDLY FAVORABLE AGAIN AFTER 24 HOURS. CONFIDENCE IS HIGH
AT THIS POINT THAT IUNE WILL DISSIPATE SOON...BUT WE ALSO REMEMBER
GENEVIEVE FROM LAST YEAR.

IUNE...AS A POST TROPICAL REMNANT LOW...WILL CONTINUE MOVING ALMOST
DUE WEST WITHIN LOW LEVEL FLOW SOUTH OF THE SUBTROPICAL RIDGE
THROUGH DISSIPATION EARLY TUESDAY MORNING. THIS ALIGNS WITH THE
PREVIOUS FORECAST TRACK AND WITH THE SHALLOW BETA AND ADVECTION
MODEL.

FORECAST POSITIONS AND MAX WINDS

INIT 13/1500Z 14.4N 164.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
12H 14/0000Z 14.3N 165.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
24H 14/1200Z...DISSIPATED

$$
FORECASTER POWELL