CPAC: TROPICAL DEPRESSION HILDA (11E)

[HURAKAN]

Another blow-up of convection over the center

[HURAKAN]

TROPICAL STORM HILDA DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112009
200 AM PDT SUN AUG 23 2009

ALTHOUGH THE CIRCULATION CENTER OF HILDA REMAINS PARTIALLY EXPOSED
THIS EVENING...SPIRAL BANDING OVER THE WESTERN PORTION OF THE
CYCLONE HAS BECOME BETTER ORGANIZED. FURTHERMORE...ENHANCED
INFRARED IMAGERY INDICATES VERY COLD CLOUD TOP TEMPERATURES
ASSOCIATED WITH THE BANDING FEATURE AND A FEW RECENT BURSTS OF DEEP
CONVECTION NEAR THE CENTER. BASED ON THE IMPROVED CLOUD PATTERN
AND A COMPROMISE OF THE DVORAK INTENSITY ESTIMATES...THE INITIAL
INTENSITY IS RAISED TO 40 KT. THE OCEANIC ENVIRONMENT IS EXPECTED
TO BE REMAIN FAVORABLE DURING THE FORECAST PERIOD...BUT THE UPPER
WIND PATTERN WILL BE ONLY MARGINALLY CONDUCIVE FOR STRENGTHENING
DUE TO PERSISTENT NORTHEASTERLY SHEAR. CONSEQUENTLY...THE
INTENSITY FORECAST CALLS FOR GRADUAL INTENSIFICATION DURING THE
NEXT 5 DAYS...SIMILAR TO THE ICON INTENSITY CONSENSUS MODEL.

INITIAL MOTION IS ESTIMATED AT 275/8...WITHIN THE DEEP-LAYER
EASTERLY FLOW OF A HIGH PRESSURE TO THE NORTH. A MID- TO UPPER
LEVEL TROUGH LOCATED A FEW HUNDRED MILES EAST-NORTHEAST OF THE
HAWAIIAN ISLANDS SHOULD CAUSE THE CYCLONE TO SLOW A BIT AND
TURN MORE TOWARD THE WEST-NORTHWEST...AS INDICATED BY THE
GFDL/GFS AND ECMWF...AROUND MID-PERIOD. AFTERWARD...RIDGING IS
FORECAST TO BUILD NORTHWEST OF HILDA IN RESPONSE TO THE
AFOREMENTIONED TROUGH FILLING AND MOVING NORTHEASTWARD OUT OF THE
AREA. THIS CHANGE IN THE STEERING PATTERN NEAR DAY 3 IS EXPECTED
TO TURN THE CYCLONE BACK TOWARD THE WEST. THE OFFICIAL FORECAST IS
CLOSE TO THE PREVIOUS TRACK AND COINCIDES WITH THE DYNAMICAL MODEL
CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 23/0900Z 13.7N 139.3W 40 KT
12HR VT 23/1800Z 13.9N 140.6W 40 KT
24HR VT 24/0600Z 14.3N 142.2W 45 KT
36HR VT 24/1800Z 14.6N 144.0W 45 KT
48HR VT 25/0600Z 14.8N 145.7W 50 KT
72HR VT 26/0600Z 15.0N 149.0W 50 KT
96HR VT 27/0600Z 15.0N 152.0W 55 KT
120HR VT 28/0600Z 15.0N 155.0W 55 KT

$$
FORECASTER ROBERTS/BROWN

[HURAKAN]

94C to the SW

[cycloneye]

TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1238 UTC SUN AUG 23 2009

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

EAST PACIFIC OBJECTIVE AIDS FOR

TROPICAL CYCLONE HILDA (EP112009) 20090823 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090823 1200 090824 0000 090824 1200 090825 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 13.7N 139.7W 14.3N 141.3W 14.8N 143.0W 15.4N 144.6W
BAMD 13.7N 139.7W 14.2N 142.2W 14.7N 144.6W 15.1N 146.9W
BAMM 13.7N 139.7W 14.6N 141.7W 15.3N 143.7W 15.8N 145.5W
LBAR 13.7N 139.7W 14.0N 141.5W 14.8N 143.6W 15.5N 145.7W
SHIP 40KTS 44KTS 48KTS 51KTS
DSHP 40KTS 44KTS 48KTS 51KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090825 1200 090826 1200 090827 1200 090828 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 15.7N 146.0W 15.8N 148.1W 15.5N 150.3W 16.1N 153.3W
BAMD 15.3N 149.1W 15.0N 152.8W 13.3N 155.9W 11.7N 158.6W
BAMM 15.9N 147.4W 15.5N 150.6W 14.2N 153.2W 13.1N 156.0W
LBAR 16.2N 147.6W 16.6N 151.1W 16.2N 154.3W 16.7N 158.0W
SHIP 54KTS 59KTS 58KTS 56KTS
DSHP 54KTS 59KTS 58KTS 56KTS

...INITIAL CONDITIONS...
LATCUR = 13.7N LONCUR = 139.7W DIRCUR = 275DEG SPDCUR = 8KT
LATM12 = 13.5N LONM12 = 138.1W DIRM12 = 274DEG SPDM12 = 8KT
LATM24 = 13.5N LONM24 = 136.4W
WNDCUR = 40KT RMAXWD = 20NM WNDM12 = 35KT
CENPRS = 1003MB OUTPRS = 1009MB OUTRAD = 120NM SDEPTH = D
RD34NE = 30NM RD34SE = 20NM RD34SW = 30NM RD34NW = 40NM

$$

[HURAKAN]

453
WTPZ21 KNHC 231449
TCMEP1
TROPICAL STORM HILDA FORECAST/ADVISORY NUMBER 5...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112009
1500 UTC SUN AUG 23 2009

CORRECTED AWIPS AND WMO HEADERS FOR NEXT ADVISORY

TROPICAL STORM CENTER LOCATED NEAR 13.8N 140.1W AT 23/1500Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT 8 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1003 MB
MAX SUSTAINED WINDS 40 KT WITH GUSTS TO 50 KT.
34 KT....... 30NE 20SE 30SW 40NW.
12 FT SEAS.. 0NE 0SE 0SW 150NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 13.8N 140.1W AT 23/1500Z
AT 23/1200Z CENTER WAS LOCATED NEAR 13.7N 139.7W

FORECAST VALID 24/0000Z 13.9N 141.4W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 40NE 20SE 30SW 40NW.

FORECAST VALID 24/1200Z 14.2N 143.1W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 40NE 20SE 30SW 40NW.

FORECAST VALID 25/0000Z 14.5N 144.8W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 40NE 20SE 30SW 40NW.

FORECAST VALID 25/1200Z 14.8N 146.5W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 20NE 0SE 0SW 10NW.
34 KT... 50NE 30SE 20SW 50NW.

FORECAST VALID 26/1200Z 14.8N 149.7W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 20NE 0SE 0SW 10NW.
34 KT... 50NE 30SE 20SW 50NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 200 NM
ON DAY 4 AND 225 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 27/1200Z 15.0N 152.5W
MAX WIND 55 KT...GUSTS 65 KT.

OUTLOOK VALID 28/1200Z 15.0N 155.5W
MAX WIND 55 KT...GUSTS 65 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 13.8N 140.1W

THIS IS THE LAST FORECAST/ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON HILDA. FUTURE ADVISORIES WILL BE ISSUED BY THE CENTRAL
PACIFIC HURRICANE CENTER UNDER AWIPS HEADER TCMCP5 AND WMO HEADER
WTPA25 PHFO...BEGINNING AT 1100 AM HST.

$$
FORECASTER KIMBERLAIN/PASCH


496
WTPZ41 KNHC 231452
TCDEP1
TROPICAL STORM HILDA DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112009
800 AM PDT SUN AUG 23 2009

INFRARED AND MICROWAVE SATELLITE IMAGERY INDICATES THAT THE CENTER
OF HILDA HAS REMAINED PARTIALLY EXPOSED ON THE NORTHEAST SIDE OF A
PULSATING MASS OF DEEP CONVECTION MOST OF THE NIGHT. MORE
RECENTLY...HOWEVER...A NEW BURST OF CONVECTION HAS OVERSPREAD THE
CIRCULATION CENTER. EVEN THOUGH DVORAK T-NUMBERS HAVE INCREASED TO
3.0 AT 1200 UTC...THERE HAS BEEN A GENERAL LACK OF IMPROVEMENT IN
ORGANIZATION. FOR THIS REASON...THE INITIAL INTENSITY IS BEING
HELD AT 40 KT. MODERATE NORTHEASTERLY SHEAR HAS PERSISTED OVER
THE CYCLONE AND GLOBAL MODELS FORECAST THIS SHEAR TO CONTINUE FOR
THE NEXT 3 DAYS. IT APPEARS THAT THE SHEAR SHOULD BE ENOUGH TO
INHIBIT SIGNIFICANT INTENSIFICATION DURING THIS TIME...DESPITE
SUFFICIENTLY WARM WATERS. BEYOND 72 HOURS...MODEL GUIDANCE BREAKS
OFF A PIECE OF A DEEP UPPER-LEVEL TROUGH ALONG 135W AND DIGS ITS
SOUTHWARD EAST OF THE HAWAIIAN ISLANDS. THIS FEATURE SHOULD BEGIN
TO PRODUCE A WESTERLY OR NORTHWESTERLY SHEAR OVER HILDA LATE IN THE
PERIOD...WHICH WOULD LIMIT INTENSIFICATION. SIMILAR TO THE
PREVIOUS ADVISORY...THE OFFICIAL FORECAST CONTINUES TO CALL FOR
ONLY SLOW STRENGTHENING...IN LINE WITH THE INTENSITY CONSENSUS
MODEL.

RECENT SATELLITE FIXES ARE A BIT UNCERTAIN BUT YIELD AN INITIAL
MOTION ESTIMATE OF 275/08. A WEAK BUT DEEP-LAYER EASTERLY FLOW
SOUTH OF A MID-LEVEL RIDGE HAS BEEN GUIDING HILDA ON AN ALMOST
DUE-WEST COURSE. LARGE-SCALE MODELS FORECAST A MID- TO UPPER-LEVEL
CYCLONIC FEATURE NEAR 23N148W TO GRADUALLY LIFT NORTHEAST THE NEXT
FEW DAYS...KEEPING THE RIDGE TO THE NORTH OF HILDA WEAK OVER THE
NEXT SEVERAL DAYS. AS A RESULT...HILDA SHOULD CONTINUE ON A SLOW
BUT GENERAL WESTERLY COURSE. THEREAFTER...THE SPREAD IN THE
GUIDANCE INCREASES AS SEVERAL MODELS KEEP A WEAK STEERING REGIME
OVER HILDA...WHILE THE GFDL/HWRF BUILD A STRONGER RIDGE TO THE
NORTHWEST AND MOVE HILDA FASTER TOWARD THE WEST OR WEST-SOUTHWEST.
THE OFFICIAL FORECAST LIES BETWEEN THE TWO EXTREMES AND IS CLOSE TO
THE PREVIOUS TRACK AND THE DYNAMICAL MODEL CONSENSUS.

FUTURE ADVISORIES ON HILDA WILL BE ISSUED BY THE CENTRAL PACIFIC
HURRICANE CENTER UNDER AWIPS HEADER TCDCP5 AND WMO HEADER WTPA45
PHFO.

FORECAST POSITIONS AND MAX WINDS

INITIAL 23/1500Z 13.8N 140.1W 40 KT
12HR VT 24/0000Z 13.9N 141.4W 40 KT
24HR VT 24/1200Z 14.2N 143.1W 45 KT
36HR VT 25/0000Z 14.5N 144.8W 45 KT
48HR VT 25/1200Z 14.8N 146.5W 50 KT
72HR VT 26/1200Z 14.8N 149.7W 50 KT
96HR VT 27/1200Z 15.0N 152.5W 55 KT
120HR VT 28/1200Z 15.0N 155.5W 55 KT

$$
FORECASTER KIMBERLAIN/PASCH

[clfenwi]

Let's see if the LLC can stay under cover today.

[HURAKAN]

Very small system

[HURAKAN]

The center remains on the northern side of the convection

[HURAKAN]

932
WTPA35 PHFO 232054
TCPCP5

BULLETIN
TROPICAL STORM HILDA ADVISORY NUMBER 6
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP112009
1100 AM HST SUN AUG 23 2009

...HILDA CONTINUES TO MOVE WESTWARD AND GRADUALLY INTENSIFY...

AT 1100 AM HST...2100 UTC...THE CENTER OF TROPICAL STORM HILDA
WAS LOCATED NEAR LATITUDE 14.0 NORTH...LONGITUDE 142.0 WEST OR
ABOUT 1160 MILES EAST-SOUTHEAST OF HONOLULU HAWAII AND ABOUT 950
MILES EAST-SOUTHEAST OF HILO HAWAII.

HILDA IS MOVING TOWARD THE WEST NEAR 12 MPH AND THIS MOTION IS
EXPECTED TO CONTINUE THROUGH THE NEXT 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH WITH HIGHER GUSTS. SOME
ADDITIONAL STRENGTHENING IS EXPECTED DURING THE NEXT 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 60 MILES FROM THE
CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB...29.62 INCHES.

...SUMMARY OF 1100 AM HST INFORMATION...
LOCATION...14.0N 142.0W
MAXIMUM SUSTAINED WINDS...50 MPH
PRESENT MOVEMENT...WEST OR 280 DEGREES AT 12 MPH
MINIMUM CENTRAL PRESSURE...1003 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE CENTRAL PACIFIC HURRICANE
CENTER AT 500 PM HST.

$$
FORECASTER WROE

598
WTPA45 PHFO 232102
TCDCP5

TROPICAL STORM HILDA DISCUSSION NUMBER 6
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP112009
1100 AM HST SUN AUG 23 2009

INFRARED IMAGERY INDICATES THAT HILDA HAS BECOME BETTER ORGANIZED
THIS MORNING...WITH A DISTINCT CURVED BAND OF DEEP CONVECTION
DEVELOPING ALONG THE SOUTHERN SIDE OF THE SYSTEM. DVORAK CI NUMBERS
FROM AROUND 1730Z CAME IN AT 2.5 FROM HFO...3.0 FROM SAB...3.5 FROM
JTWC...AND 3.2 FROM CIMSS ADT. AN AVERAGE OF THESE CI NUMBERS
YIELDS AN INTENSITY OF 45 KTS...WHICH IS ALSO THE MAXIMUM WIND
SPEED CALCULATED BY AN EARLIER QUIKSCAT PASS AT 1509Z. THUS...THE
INITIAL INTENSITY IS INCREASED TO 45 KT. THE 34 KT RADII HAVE ALSO
BEEN EXPANDED BASED ON THE QUIKSCAT DATA.

THE FORWARD MOTION OF HILDA HAS ACCELERATED THIS MORNING...LIKELY DUE
TO HILDA BECOMING LESS INFLUENCED BY THE NEARBY ITCZ AND
INCREASINGLY STEERED IN THE DEEP EASTERLY FLOW BEING PRODUCED BY
RIDGING AT THE SURFACE AND ALOFT TO THE NORTH. THE NEW MOTION IS
280/10.

HILDA IS FORECAST TO INTENSIFY SLIGHTLY AND CONTINUE ON A TRACK THAT
IS JUST NORTH OF DUE WEST THROUGH THE NEXT 48 HOURS AS RIDGING AT
THE SURFACE AND ALOFT REMAINS TO THE NORTH. THE NEW TRACK IS FASTER
THAN THE PREVIOUS PACKAGE TO ACCOUNT FOR THE FASTER FORWARD MOTION.
THE FORECAST FORWARD SPEED IS CLOSE TO THE HWRF...BUT THE TRACK HAS
BEEN SET ESSENTIALLY DOWN THE MIDDLE OF THE GUIDANCE ENVELOPE. THE
FLOW ALOFT IS ALSO CREATING AROUND 15 KT OF EASTERLY VERTICAL WIND
SHEAR AND IS INHIBITING OUTFLOW ALONG THE NORTHEAST SIDE OF THE
SYSTEM. EVEN THOUGH HILDA WILL BE OVER SUFFICIENTLY WARM SST
VALUES...THIS SHEAR IS FORECAST TO ALLOW ONLY A SMALL AMOUNT OF
INTENSIFICATION OVER THE NEXT TWO DAYS. THE INTENSITY FORECAST IS
CLOSE TO THE PREVIOUS PACKAGE AND TO ICON.

BY 72 HOURS...THE TRACK OF HILDA SHIFTS TO THE DUE WEST AS RIDGING
ALOFT STRENGTHENS OVER AND TO THE NORTHWEST OF THE HAWAIIAN ISLANDS
AS A DEEP UPPER TROUGH DIGS FAR EAST OF THE ISLANDS NEAR 140W. THE
GFS AND SHIPS FORECAST THE WIND SHEAR TO SHIFT MORE NORTHERLY AND
RELAX SLIGHTLY. SOME SLIGHT STRENGTHENING IS FORECAST TO REMAIN
CLOSE TO ICON INTENSITY GUIDANCE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 23/2100Z 14.0N 142.0W 45 KT
12HR VT 24/0600Z 14.4N 143.5W 45 KT
24HR VT 24/1800Z 14.8N 145.5W 50 KT
36HR VT 25/0600Z 15.1N 147.5W 50 KT
48HR VT 25/1800Z 15.2N 149.4W 50 KT
72HR VT 26/1800Z 15.3N 152.6W 50 KT
96HR VT 27/1800Z 15.3N 155.7W 55 KT
120HR VT 28/1800Z 15.3N 158.7W 55 KT

$$
FORECASTER WROE

[HURAKAN]

West Hilda goes

[HURAKAN]

Continues to look good. Solid, small system

[Kingarabian]

Is it just me or the updates for Hilda aint showing on CPHC?

[clfenwi]

Continued improvement in appearance.



24/0000 UTC 14.1N 142.7W T3.5/3.5 HILDA -- Central Pacific



Kingarabian, in case you still need a link, here's the CPHC's Hilda page.

[clfenwi]

SHIPS is now taking Hilda to hurricane strength.

Code: Select all

WHXX01 KMIA 240049
CHGE77
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
0049 UTC MON AUG 24 2009
 
DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO CPHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.
 
CENTRAL PACIFIC OBJECTIVE AIDS FOR
 
TROPICAL CYCLONE HILDA (EP112009) 20090824 0000 UTC
 
        ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
        090824  0000   090824  1200   090825  0000   090825  1200
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    14.1N 142.7W   14.7N 144.3W   15.3N 145.8W   15.7N 147.1W
BAMD    14.1N 142.7W   14.6N 145.2W   15.1N 147.5W   15.7N 149.5W
BAMM    14.1N 142.7W   14.8N 145.0W   15.4N 146.9W   15.7N 148.7W
LBAR    14.1N 142.7W   14.6N 144.8W   15.5N 146.9W   16.2N 148.9W
SHIP        50KTS          58KTS          63KTS          66KTS
DSHP        50KTS          58KTS          63KTS          66KTS
 
        ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
        090826  0000   090827  0000   090828  0000   090829  0000
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    16.3N 148.0W   16.2N 149.4W   16.1N 151.6W   17.3N 155.5W
BAMD    16.1N 151.4W   15.6N 154.4W   13.8N 156.9W   12.4N 160.2W
BAMM    16.0N 150.4W   15.2N 152.8W   12.9N 154.9W   11.6N 157.7W
LBAR    16.5N 150.7W   16.5N 153.6W   16.2N 156.8W   16.8N 160.8W
SHIP        67KTS          68KTS          70KTS          69KTS
DSHP        67KTS          68KTS          70KTS          69KTS
 
         ...INITIAL CONDITIONS...
LATCUR =  14.1N LONCUR = 142.7W DIRCUR = 280DEG SPDCUR =  12KT
LATM12 =  13.8N LONM12 = 140.2W DIRM12 = 277DEG SPDM12 =  13KT
LATM24 =  13.5N LONM24 = 138.1W
WNDCUR =   50KT RMAXWD =   15NM WNDM12 =   40KT
CENPRS = 1001MB OUTPRS = 1009MB OUTRAD =  125NM SDEPTH =   D
RD34NE =   50NM RD34SE =   40NM RD34SW =   40NM RD34NW =  50NM
 
$$
NNNN



[HURAKAN]

Looking good

[HURAKAN]

* EAST PACIFIC SHIPS INTENSITY FORECAST *
* GOES DATA AVAILABLE *
* OHC DATA AVAILABLE *
* HILDA EP112009 08/24/09 00 UTC *

SHEAR (KT) 17 15 15 15 11 11 22 16 10 2 5 3 1
SHEAR DIR 59 63 53 56 52 30 51 64 85 138 78 278 274
SST (C) 27.8 27.7 27.6 27.5 27.3 27.2 27.2 27.3 27.5 27.6 27.5 27.3 27.3

Shear expected to lessen in a few days

[brunota2003]

Looks really good, she very well could reach Cat 1. She is such a small system, could ramp up extremely quickly.

[clfenwi]

WTPA35 PHFO 240246
TCPCP5

BULLETIN
TROPICAL STORM HILDA ADVISORY NUMBER 7
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP112009
500 PM HST SUN AUG 23 2009

...HILDA CONTINUES TO MOVE WESTWARD AND GRADUALLY INTENSIFY...

AT 500 PM HST...0300 UTC...THE CENTER OF TROPICAL STORM HILDA WAS
LOCATED NEAR LATITUDE 14.2 NORTH...LONGITUDE 143.2 WEST OR ABOUT
1085 MILES EAST-SOUTHEAST OF HONOLULU HAWAII AND ABOUT 875 MILES
EAST-SOUTHEAST OF HILO HAWAII.

HILDA IS MOVING TOWARD THE WEST NEAR 12 MPH AND THIS MOTION IS
EXPECTED TO CONTINUE FOR THE NEXT 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH WITH HIGHER GUSTS. SOME
ADDITIONAL STRENGTHENING IS EXPECTED DURING THE NEXT 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 60 MILES FROM THE
CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1001 MB...29.56 INCHES.

...SUMMARY OF 500 PM HST INFORMATION...
LOCATION...14.2N 143.2W
MAXIMUM SUSTAINED WINDS...60 MPH
PRESENT MOVEMENT...WEST OR 280 DEGREES AT 12 MPH
MINIMUM CENTRAL PRESSURE...1001 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE CENTRAL PACIFIC HURRICANE
CENTER AT 1100 PM HST.

$$
FORECASTER WROE




WTPA45 PHFO 240247
TCDCP5

TROPICAL STORM HILDA DISCUSSION NUMBER 7
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP112009
500 PM HST SUN AUG 23 2009

HILDA CONTINUES TO GRADUALLY INTENSIFY...DESPITE THE PRESENCE OF
MODERATE...EASTERLY VERTICAL WIND SHEAR. AN ORGANIZED BAND OF DEEP
CONVECTION ALONG THE SOUTHERN AND EASTERN SIDE OF HILDA HAS
PERSISTED THROUGH THE DAY AND HAS RESULTED IN THE DVORAK CI NUMBERS
FROM ALL THE FIX AGENCIES AND ADT TO INCREASE BY AT LEAST 0.5 IN
THE PAST SIX HOURS. IN ADDITION...UW-CIMSS AMSU INTENSITY ALGORITHM
HAS DETECTED A STRENGTHENING WARM CORE ALOFT. THUS...THE INITIAL
INTENSITY HAS BEEN RAISED TO 50 KT.

THE INITIAL MOTION IS 280/10...ESSENTIALLY UNCHANGED FROM SIX HOURS
AGO. HILDA IS BEING STEERED IN A GENERAL WESTERLY DIRECTION WITHIN
A DEEP EASTERLY FLOW CREATED BY AN UPPER LEVEL ANTICYCLONE TO THE
NORTH ALONG 20N AND A STRONG SURFACE HIGH FARTHER NORTH. THE
EASTERLY FLOW ALOFT IS CREATING MODERATE...EASTERLY VERTICAL WIND
SHEAR AROUND 15 KT AND IS INHIBITING OUTFLOW ALONG THE NORTHEAST
QUADRANT OF HILDA. IN SPITE OF THESE MARGINAL CONDITIONS...HILDA
HAS MANAGED TO INTENSIFY TODAY.

HILDA IS FORECAST TO INTENSIFY SLIGHTLY AND CONTINUE ON A TRACK THAT
IS JUST NORTH OF DUE WEST THROUGH THE NEXT 48 HOURS AS RIDGING AT
THE SURFACE AND ALOFT REMAINS TO THE NORTH. THE FORECAST TRACK IS
ESSENTIALLY DOWN THE MIDDLE OF A TIGHTLY CLUSTERED GUIDANCE
ENVELOPE DURING THE FIRST 36 HOURS AND IS ALONG THE NORTHERN
PORTION OF THE ENVELOPE BY 48 HOURS. WITH SST VALUES HOVERING
AROUND 27C AND WINDS ALOFT CHANGING LITTLE...A GRADUAL
INTENSIFICATION TREND IS FORECAST TO PERSIST THROUGH 48 HOURS. THE
FORECAST INTENSIFIES HILDA SLIGHTLY FASTER THAN THE PREVIOUS PACKAGE
AND FOLLOWS ICON RELATIVELY CLOSELY.

BY 72 HOURS...THE TRACK OF HILDA SHIFTS TO THE DUE WEST AS RIDGING
ALOFT STRENGTHENS OVER AND TO THE WEST OF THE HAWAIIAN ISLANDS AS A
DEEP UPPER TROUGH DIGS FAR EAST OF THE ISLANDS BETWEEN 150W AND
140W. THE DYNAMIC MODELS AND SHIPS FORECAST THE WIND SHEAR TO SHIFT
MORE NORTHERLY BUT RELAX SLIGHTLY AT THIS TIME. DUE TO THE
UNCERTAINTY OF THESE EFFECTS...THE FORECAST INTENSIFICATION HAS
BEEN HALTED AFTER 48 HOURS...WITH HILDA REMAINING AT A HIGH END
TROPICAL STORM. HOWEVER...IT WOULD NOT BE SURPRISING IF HILDA
INTENSIFIES FURTHER AFTER 48 HOURS AND BECOMES A HURRICANE AS A
GOOD NUMBER OF THE INTENSITY MODELS PREDICT. THE TRACK FORECAST AT
72 HOURS AND BEYOND IS SLIGHTLY TO THE RIGHT OF AN INCREASINGLY
DIVERGENT GUIDANCE ENVELOPE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 24/0300Z 14.2N 143.2W 50 KT
12HR VT 24/1200Z 14.6N 144.6W 50 KT
24HR VT 25/0000Z 15.0N 146.7W 55 KT
36HR VT 25/1200Z 15.3N 148.7W 55 KT
48HR VT 26/0000Z 15.4N 150.7W 60 KT
72HR VT 27/0000Z 15.3N 154.2W 60 KT
96HR VT 28/0000Z 15.2N 156.9W 60 KT
120HR VT 29/0000Z 15.0N 160.0W 60 KT

$$
FORECASTER WROE

[HURAKAN]

000
WTPA45 PHFO 240846
TCDCP5

TROPICAL STORM HILDA DISCUSSION NUMBER 8
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP112009
1100 PM HST SUN AUG 23 2009

HILDA/S SATELLITE SIGNATURE HAS SHOWN SOME INCREASE IN ORGANIZATION
OVER THE PAST 6 HOURS...LEADING TO DVORAK CURRENT INTENSITY
ESTIMATES OF 3.5 FROM SAB...PGTW AND PHFO. GIVEN THIS CONSENSUS...
THE INITIAL INTENSITY HAS BEEN INCREASED TO 55 KT WITH THIS
ADVISORY. A 0338 UTC QUIKSCAT PASS WAS THE BASIS FOR INCREASING THE
34 KT WIND RADII WITHIN THE NORTHERN SEMICIRCLE.

INITIAL MOTION CONTINUES AT 280/10...AS HILDA REMAINS IN DEEP
EASTERLY FLOW SOUTH OF AN EAST-WEST RIDGE ALOFT ALONG 20N...AND A
SURFACE RIDGE ALONG 35N. THESE DEEP LAYER EASTERLIES ARE CREATING
MODERATE EASTERLY SHEAR OVER HILDA...AND ARE INHIBITING OUTFLOW IN
THE NORTHERN SEMICIRCLE. LITTLE CHANGE IN THIS SETUP IS EXPECTED IN
THE SHORT TERM...AND THE TRACK FORECAST CLOSELY FOLLOWS THE
PREVIOUS ADVISORY THROUGH 48 HOURS. AFTER 48 HOURS...HILDA/S MOTION
WILL BE LESS INFLUENCED BY A MID-LEVEL HIGH TO ITS NORTHEAST...AND
INCREASINGLY BY A MID-LEVEL HIGH BUILDING SOUTHWARD TO ITS
NORTHWEST. THIS WILL RESULT IN SOME SLOWING OF THE FORWARD MOTION
ON DAYS 3 AND 4...AND A REDUCTION OF THE VERTICAL SHEAR...WITH
HILDA CONTINUING TOWARD THE WEST. AS COMPARED TO THE PREVIOUS
ADVISORY...THIS TRACK FORECAST REPRESENTS A SLIGHTLY SLOWER FORWARD
MOTION ON DAYS 3 THROUGH 5.

THE FORECAST TRACK TAKES HILDA OVER WATERS SUFFICIENTLY WARM TO
SUPPORT A HURRICANE...AND WITH HILDA ABLE TO SLOWLY INTENSIFY IN THE
FACE OF MODERATE SHEAR OVER THE PAST 2 DAYS...THIS TREND IS FORECAST
TO CONTINUE. SOME EASING OF THE VERTICAL WIND SHEAR ON DAYS 3 AND 4
IS EXPECTED TO ALLOW HILDA TO CONTINUE TO INTENSIFY. THIS INTENSITY
FORECAST REPRESENTS AN INCREASE FROM THE PREVIOUS ADVISORY...AND IS
CLOSE TO SHIPS AND LGEM...WHICH BOTH FORECAST HILDA TO BECOME A
HURRICANE IN 24 TO 36 HOURS.


FORECAST POSITIONS AND MAX WINDS

INITIAL 24/0900Z 14.3N 144.1W 55 KT
12HR VT 24/1800Z 14.7N 145.7W 55 KT
24HR VT 25/0600Z 15.0N 147.6W 60 KT
36HR VT 25/1800Z 15.2N 149.5W 65 KT
48HR VT 26/0600Z 15.2N 151.3W 65 KT
72HR VT 27/0600Z 15.1N 154.3W 70 KT
96HR VT 28/0600Z 15.1N 157.2W 70 KT
120HR VT 29/0600Z 15.0N 160.0W 75 KT

$$

FORECASTER BIRCHARD

[HURAKAN]

Very small cyclone