CPAC: FERNANDA - Tropical Depression

[Macrocane]

Yeah it looks pretty good, it has developed a nice CDO, I'd go with 60 kt. Let's see if it becomes a hurricane in the next advisory before it reaches a less favorable environment. that would be a 7/7 for the EPAC.

[Kingarabian]

Yeah it looks pretty good, it has developed a nice CDO, I'd go with 60 kt. Let's see if it becomes a hurricane in the next advisory before it reaches a less favorable environment. that would be a 7/7 for the EPAC.

Has 24 hours before that Hawaiian shear starts kicking in.

[Extratropical94]

Dvorak is up to 3.5/3.5 - 65 knots
BT supports 55 knots.
Same situation as with Greg yesterday.

[Kingarabian]

Dvorak is up to 3.5/3.5 - 65 knots
BT supports 55 knots.
Same situation as with Greg yesterday.

Knowing the NHC they might go on the conservative side... Anyway pretty interesting to see it strengthen despite being in that stable environment.

[Kingarabian]

000
WTPZ41 KNHC 180838
TCDEP1

TROPICAL STORM FERNANDA DISCUSSION NUMBER 11
NWS NATIONAL HURRICANE CENTER MIAMI FL EP062011
200 AM PDT THU AUG 18 2011

DEEP CONVECTION HAS BLOSSOMED NEAR THE CENTER OF FERNANDA AND A
CYCLONICALLY CURVED CONVECTIVE BAND HAS FORMED IN THE WESTERN
SEMICIRCLE. T-NUMBERS FROM BOTH TAFB AND SAB HAVE INCREASED TO 3.5
ON THE DVORAK SCALE INDICATING THE WINDS ARE NOW 55 KNOTS. SINCE
FERNANDA WILL SOON BE MOVING INTO A RELATIVELY STABLE AIR MASS AND
OVER MARGINAL SEA SURFACE TEMPERATURES...NO SIGNIFICANT CHANGE IN
STRENGTH IS ANTICIPATED FOR THE NEXT 12 HOURS. THEREAFTER...THE
VERTICAL SHEAR IS EXPECTED TO INCREASE AND A WEAKENING TREND SHOULD
BEGIN. AS IN THE PREVIOUS FORECAST...FERNANDA IS EXPECTED TO BE A
REMNANT LOW BY THE TIME IT MOVES SOUTH OF THE HAWAIIAN ISLANDS. THE
WIND RADII WERE ADJUSTED BASED ON A 0618 UTC ASCAT.

FERNANDA IS MOVING TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 8
KNOTS DUE TO A WEAKNESS IN THE SUBTROPICAL RIDGE IN THE VICINITY OF
140W. HOWEVER AS THE RIDGE REBUILDS...AS ANTICIPATED BY GLOBAL
MODELS...THE CYCLONE SHOULD ACQUIRE A MORE WESTWARD COMPONENT. LATER
IN THE FORECAST PERIOD...FERNANDA OR ITS REMNANTS WILL BECOME
STEERED WESTWARD BY THE LOW-LEVEL TRADE WINDS. THE OFFICIAL TRACK
FORECAST IS VERY CLOSE TO THE DYNAMICAL MODEL CONSENSUS.

BASED ON THE CURRENT FORECAST...FERNANDA WILL BE IN THE CENTRAL
PACIFIC HURRICANE CENTER AREA OF RESPONSIBILITY AROUND 1200 UTC.
THEREFORE...THE NEXT 1500 UTC ADVISORY PACKAGE WILL BE ISSUED BY
THE CENTRAL PACIFIC HURRICANE CENTER. FUTURE INFORMATION ON THIS
SYSTEM CAN BE FOUND IN PUBLIC ADVISORIES...UNDER AWIPS HEADER
HNLTCPCP1 AND WMO HEADER WTPA41 PHFO. FORECAST/ADVISORIES ARE FOUND
UNDER HNLTCPC1 AND WMO HEADER WTPA41 PHFO.


FORECAST POSITIONS AND MAX WINDS

INIT 18/0900Z 13.4N 139.9W 55 KT 65 MPH
12H 18/1800Z 14.0N 141.1W 55 KT 65 MPH
24H 19/0600Z 14.5N 143.0W 50 KT 60 MPH
36H 19/1800Z 15.5N 145.0W 45 KT 50 MPH
48H 20/0600Z 16.0N 147.0W 40 KT 45 MPH
72H 21/0600Z 17.0N 151.0W 30 KT 35 MPH
96H 22/0600Z 17.0N 155.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 23/0600Z...DISSIPATED

$$
FORECASTER AVILA

[Chacor]

Dvorak is up to 3.5/3.5 - 65 knots
BT supports 55 knots.
Same situation as with Greg yesterday.

3.5 is 55 knots. 4.0 is 65 knots. The BT is actually in agreement with the Dvorak, and not under. Same as Greg yesterday.

[Chacor]

Definitely looks west of 140°W now.

[Chacor]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
500 AM PDT THU AUG 18 2011

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON HURRICANE
GREG...LOCATED ABOUT 340 MILES SOUTH OF THE SOUTHERN TIP OF BAJA
CALIFORNIA. THE NATIONAL HURRICANE CENTER HAS ISSUED ITS FINAL
ADVISORY ON TROPICAL STORM FERNANDA...WHICH HAS MOVED INTO CENTRAL
PACIFIC HURRICANE BASIN.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

PUBLIC ADVISORIES ON FERNANDA ARE NOW ISSUED UNDER WMO HEADER
WTPZ31 PHFO AND UNDER AWIPS HEADER MIATCPCP1.
FORECAST/ADVISORIES ON FERNANDA ARE NOW ISSUED UNDER WMO HEADER
WTPZ21 PHFO AND UNDER AWIPS HEADER MIATCMCP1.

$$
FORECASTER BEVEN

I think that settles the earlier argument

[plasticup]

It's not that often you see storms making a run at Hawaii. The last one I can recall is Flossie, but there may have been a few in the intervening years.

[Yellow Evan]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
500 AM PDT THU AUG 18 2011

FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON HURRICANE
GREG...LOCATED ABOUT 340 MILES SOUTH OF THE SOUTHERN TIP OF BAJA
CALIFORNIA. THE NATIONAL HURRICANE CENTER HAS ISSUED ITS FINAL
ADVISORY ON TROPICAL STORM FERNANDA...WHICH HAS MOVED INTO CENTRAL
PACIFIC HURRICANE BASIN.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

PUBLIC ADVISORIES ON FERNANDA ARE NOW ISSUED UNDER WMO HEADER
WTPZ31 PHFO AND UNDER AWIPS HEADER MIATCPCP1.
FORECAST/ADVISORIES ON FERNANDA ARE NOW ISSUED UNDER WMO HEADER
WTPZ21 PHFO AND UNDER AWIPS HEADER MIATCMCP1.

$$
FORECASTER BEVEN

I think that settles the earlier argument

Check my two links please you never did.

[Chacor]

And you know that how? How can you come into a forum and start attacking the established users for "false information" when they're not wrong at all? You need to take a step back and admit you're wrong here. Even the NHC calls the CPAC a different basin.

[HURAKAN]

18/1200 UTC 13.6N 140.3W T4.0/4.0 FERNANDA -- Central Pacific

4.0 = 65 knots

[Chacor]

Probably a mistake, but the NHC has uploaded the CPHC's 1500 UTC forecast even before the CPHC has officially released it:

TROPICAL STORM FERNANDA FORECAST/ADVISORY NUMBER 12
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP062011
1500 UTC THU AUG 18 2011

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

TROPICAL STORM CENTER LOCATED NEAR 13.7N 141.0W AT 18/1500Z
POSITION ACCURATE WITHIN 25 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 11 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 994 MB
MAX SUSTAINED WINDS 55 KT WITH GUSTS TO 65 KT.
50 KT....... 20NE 0SE 0SW 20NW.
34 KT....... 70NE 40SE 30SW 50NW.
12 FT SEAS..100NE 30SE 75SW 110NW.
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 13.7N 141.0W AT 18/1500Z
AT 18/1200Z CENTER WAS LOCATED NEAR 13.4N 140.5W

FORECAST VALID 19/0000Z 14.4N 142.4W
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 20NE 0SE 0SW 20NW.
34 KT... 40NE 40SE 30SW 50NW.

FORECAST VALID 19/1200Z 15.1N 144.3W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 20NE 0SE 0SW 20NW.
34 KT... 40NE 40SE 30SW 50NW.

FORECAST VALID 20/0000Z 15.8N 146.3W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 40NE 40SE 30SW 50NW.

FORECAST VALID 20/1200Z 16.3N 148.4W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 40NE 40SE 30SW 50NW.

FORECAST VALID 21/1200Z 17.0N 152.3W
MAX WIND 30 KT...GUSTS 40 KT.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 200 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 22/1200Z 16.8N 156.4W...POST-TROP/REMNT LOW
MAX WIND 25 KT...GUSTS 35 KT.

OUTLOOK VALID 23/1200Z...DISSIPATED

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 13.7N 141.0W

NEXT ADVISORY AT 18/2100Z

$$
FORECASTER POWELL

[Yellow Evan]

And you know that how? How can you come into a forum and start attacking the established users for "false information" when they're not wrong at all? You need to take a step back and admit you're wrong here. Even the NHC calls the CPAC a different basin.

I've emailed the NHC about this. http://en.wikipedia.org/wiki/File:7_zones_dels_ciclons_tropicals.jpgand http://www.aoml.noaa.gov/hrd/Landsea/climvari/table.html do not call it separate, neither does HURDAT. Why is everyone here so conservative to believe that?

[Yellow Evan]

Not to mention what they said in the disco.


BASED ON THE CURRENT FORECAST...FERNANDA WILL BE IN THE CENTRAL
PACIFIC HURRICANE CENTER AREA OF RESPONSIBILITY AROUND 1200 UTC.
THEREFORE...THE NEXT 1500 UTC ADVISORY PACKAGE WILL BE ISSUED BY
THE CENTRAL PACIFIC HURRICANE CENTER. FUTURE INFORMATION ON THIS
SYSTEM CAN BE FOUND IN PUBLIC ADVISORIES...UNDER AWIPS HEADER
HNLTCPCP1 AND WMO HEADER WTPA41 PHFO. FORECAST/ADVISORIES ARE FOUND
UNDER HNLTCPC1 AND WMO HEADER WTPA41 PHFO.

It calls it an AOR not a basin.

[CrazyC83]

It's very confusing.

Anyway, Fernanda looks to have strenghtened. Probably 60 kt right now.

[Kingarabian]

It's not that often you see storms making a run at Hawaii. The last one I can recall is Flossie, but there may have been a few in the intervening years.

Felicia in 09 was the last storm. Anyway it's continuing to strengthen...

[Yellow Evan]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 18 AUG 2011 Time : 123000 UTC
Lat : 13:44:37 N Lon : 140:21:21 W


CI# /Pressure/ Vmax
4.5 / 980.3mb/ 77.0kt


Final T# Adj T# Raw T#
4.5 4.5 3.5

Center Temp : -69.8C Cloud Region Temp : -66.1C

Scene Type : UNIFORM CDO CLOUD REGION w/ MW EYE

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : MW ON
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 47km
- Environmental MSLP : 1011mb

Satellite Viewing Angle : 17.3 degrees

77 knt, wow

[Chacor]

ADT's Raw T 3.5 is more accurate here, per the CPHC's objective fix:

TXPN41 PHFO 181205
TCSNP1

CENTRAL PACIFIC TROPICAL CYCLONE SUMMARY - FIXES
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI
1205 UTC THU AUG 18 2011

A. TROPICAL STORM FERNANDA

B. 18/1130Z

C. 13.4N

D. 140.6W

E. GOES-11

F. T/3.5/3.5/D0.5/24 HRS

G. IR/ANIMATION

H. REMARKS...DEEP CONVECTION PERSISTS ACROSS AND WITHIN 60 NM OF
LLCC...HOWEVER SINCE THIS SYSTEM HAS BEEN ANALYZED WITH AN FT OF 3.5
FOR LESS THAN 12 HOURS...WE WILL USE SHEAR METHOD TO OBTAIN A DT OF
3.5. PATTERN T IS A ROBUST 4.0 USING 3.5 PLUS 0.5 FOR WHITE
CONVECTIVE TOPS IN BD ENHANCEMENT. MET IS 4.5 USING A 1 T NUMBER PER
DAY RATE FOR DEVELOPING SYSTEMS. DT SEEMS MOST REASONABLE GIVEN THE
LACK OF AN EYE...SO FINAL T IS 3.5 USING DT.

I. ADDL POSITIONS
NONE

$$

POWELL

For all intents and purposes, without an eye on IR, vis or microwave, this is not a 77-knot hurricane:

[CrazyC83]

Agreed T3.5 is more reasonable. 60 kt seems the best intensity IMO as a blend of the data with a lean towards 3.5.