CPAC: GIL - Post-Tropical

[cycloneye]

TROPICAL DEPRESSION GIL DISCUSSION NUMBER 25
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072013
800 AM PDT MON AUG 05 2013

GIL HAS BEEN MAINTAINING ENOUGH DEEP CONVECTION OVER THE PAST 6-12
HOURS TO RESET THE REMNANT LOW CLOCK BACK TO ZERO...AND A PAIR OF
ASCAT PASSES AROUND 07Z SUGGEST THAT THE SYSTEM STILL HAS WINDS OF
25-30 KT. THE ASCAT PASSES WERE ALSO HELPFUL IN ESTABLISHING THE
CENTER POSITION AND INITIAL MOTION...NOW ESTIMATED AT 250/7...AND
SUGGEST THAT THE CENTER IS WELL EMBEDDED IN THE CONVECTION.

ALTHOUGH THE ENVIRONMENTAL THERMODYNAMICS ARE NOT CONDUCIVE TO
STRENGTHENING...EASTERLY SHEAR IS NOT PROHIBITIVE AND THE
UNDERLYING SSTS OF 27C COULD SUPPORT INTERMITTENT CONVECTION OVER
THE NEXT FEW DAYS. MOST OF THE DYNAMICAL GUIDANCE SUGGESTS A
ROUGHLY STEADY STATE FOR GIL DURING THE FORECAST PERIOD...AND THE
SHIPS AND LGEM SHOW THE SYSTEM ULTIMATELY REGAINING TROPICAL STORM
STATUS. WITH CONVECTION CURRENTLY ACTIVE...THE OFFICIAL FORECAST
DELAYS DEGENERATION TO A REMNANT LOW UNTIL TOMORROW.

THE LATEST TRACK FORECAST ASSUMES A LITTLE MORE INTERACTION WITH A
MID-LEVEL TROUGH AFTER ABOUT 36 HOURS...AS SHOWN BY MOST OF THE
CURRENT DYNAMICAL GUIDANCE...AND IS A LITTLE SLOWER AND TO THE
NORTH OF THE PREVIOUS FORECAST. BASED ON THE CURRENT PROJECTION...
GIL WILL MOVE INTO THE CENTRAL PACIFIC HURRICANE CENTER AREA OF
RESPONSIBILITY FOR THE 06/09Z ADVISORY PACKAGE.


FORECAST POSITIONS AND MAX WINDS

INIT 05/1500Z 13.4N 138.6W 25 KT 30 MPH
12H 06/0000Z 13.0N 139.6W 25 KT 30 MPH
24H 06/1200Z 12.6N 140.9W 25 KT 30 MPH
36H 07/0000Z 12.5N 142.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 07/1200Z 12.5N 144.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 08/1200Z 13.0N 147.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 09/1200Z 13.5N 151.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 10/1200Z 14.0N 155.0W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
FORECASTER FRANKLIN

[cycloneye]

TROPICAL DEPRESSION GIL DISCUSSION NUMBER 26
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072013
200 PM PDT MON AUG 05 2013

A SMALL AREA OF DEEP CONVECTION HAS BEEN PERSISTING FOR THE PAST 10
HOURS OR SO NEAR AND TO THE NORTH OF THE CENTER OF GIL. THE INITIAL
WIND SPEED IS NUDGED UPWARD TO 30 KT FOR THIS ADVISORY ASSUMING
THAT THE WINDS ARE A LITTLE STRONGER THAN EARLIER DUE TO THE
PERSISTENT CONVECTION. THE DYNAMICAL GUIDANCE SHOWS GIL CHANGING
LITTLE IN STRENGTH OVER THE NEXT DAY OR TWO WHILE IT REMAINS OVER
SEA SURFACE TEMPERATURES OF AROUND 27C...AND WITHIN MODERATE
SOUTHEASTERLY SHEAR. GIL IS FORECAST TO BECOME A REMNANT LOW IN
ABOUT 36 HOURS...THE SAME AS SHOWN IN THE PREVIOUS FORECAST.

THE COMPACT TROPICAL CYCLONE REMAINS ON TRACK...AND IS MOVING
SOUTHWESTWARD AT ABOUT 8 KT. A TURN TO THE WEST IS FORECAST TO
OCCUR BY LATE TUESDAY WHEN THE CYCLONE BECOMES EMBEDDED IN LOW TO
MID-LEVEL EASTERLY FLOW. BASED ON THE CURRENT FORECAST...GIL WILL
MOVE INTO THE CENTRAL PACIFIC HURRICANE CENTER AREA OF
RESPONSIBILITY FOR THE 06/09Z ADVISORY.

FORECAST POSITIONS AND MAX WINDS

INIT 05/2100Z 13.2N 139.4W 30 KT 35 MPH
12H 06/0600Z 12.9N 140.4W 30 KT 35 MPH
24H 06/1800Z 12.6N 141.7W 30 KT 35 MPH
36H 07/0600Z 12.6N 143.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 07/1800Z 12.8N 144.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 08/1800Z 13.5N 147.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 09/1800Z 14.0N 151.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 10/1800Z 14.0N 155.0W 20 KT 25 MPH...POST-TROP/REMNT LOW

$$
FORECASTER CANGIALOSI

[cycloneye]

TROPICAL DEPRESSION GIL DISCUSSION NUMBER 27
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072013
800 PM PDT MON AUG 05 2013

THE LOW-LEVEL CENTER BECAME PARTIALLY EXPOSED TO THE WEST OF THE
MAIN AREA OF DEEP CONVECTION OVER THE PAST SEVERAL HOURS. ALTHOUGH
THE ASSOCIATED DEEP CONVECTION HAS BEEN PULSATING...SOME BANDING
FEATURES HAVE BEEN TRYING TO DEVELOP OVER THE EASTERN PORTION OF
THE CIRCULATION. THE INTENSITY IS HELD AT 30 KT IN AGREEMENT WITH
A DVORAK ESTIMATE FROM TAFB. MOST OF THE GUIDANCE DOES NOT SHOW
THE SYSTEM DISSIPATING DURING THE FORECAST PERIOD. INDEED...THE
STATISTICAL-DYNAMICAL LGEM MODEL SHOWS GIL REGAINING TROPICAL STORM
STRENGTH. ALTHOUGH THIS IS CERTAINLY A POSSIBLE SCENARIO...THE NHC
FORECAST IS MORE CONSERVATIVE THAN THAT AND MERELY SHOWS GIL
MAINTAINING TROPICAL CYCLONE STATUS AS A 30-KT DEPRESSION THROUGH
THE FORECAST PERIOD. THIS IS IN GOOD AGREEMENT WITH THE LATEST
HWRF MODEL FORECAST.

LATEST GEOSTATIONARY SATELLITE CENTER FIXES...AND A FIX FROM AN
EARLIER TRMM IMAGE...INDICATE THAT THE CYCLONE IS TURNING TOWARD
THE WEST AND THE MOTION ESTIMATE IS 260/8. A LOW-LEVEL RIDGE TO
THE NORTH OF GIL SHOULD BE MORE OR LESS MAINTAINED FOR THE NEXT
SEVERAL DAYS. THIS SHOULD CAUSE A WESTWARD OR WEST-NORTHWESTWARD
MOTION THROUGH THE FORECAST PERIOD. THE OFFICIAL FORECAST IS CLOSE
TO THE DYNAMICAL MODEL CONSENSUS...AND NOT AS FAST AS THE ECMWF
SOLUTION.

GIL HAS JUST MOVED WEST OF 140W LONGITUDE...SO THE NEXT ADVISORY
WILL BE ISSUED BY THE CENTRAL PACIFIC HURRICANE CENTER. FUTURE
PUBLIC ADVISORIES ON GIL CAN BE FOUND UNDER WMO HEADER WTPA32 PHFO
AND AWIPS HEADER HFOTCPCP2. FUTURE FORECAST DISCUSSIONS ON GIL CAN
BE FOUND UNDER WMO HEADER WTPA42 PHFO AND AWIPS HEADER HFOTCDCP2.

FORECAST POSITIONS AND MAX WINDS

INIT 06/0300Z 13.4N 140.2W 30 KT 35 MPH
12H 06/1200Z 13.2N 141.2W 30 KT 35 MPH
24H 07/0000Z 13.1N 142.5W 30 KT 35 MPH
36H 07/1200Z 13.3N 143.9W 30 KT 35 MPH
48H 08/0000Z 13.6N 145.4W 30 KT 35 MPH
72H 09/0000Z 14.5N 148.8W 30 KT 35 MPH
96H 10/0000Z 14.5N 152.0W 30 KT 35 MPH
120H 11/0000Z 14.5N 155.5W 30 KT 35 MPH

$$
FORECASTER PASCH

[Yellow Evan]

Gil may not been done after all.

[TropicalAnalystwx13]

Tropical Storm Gil

EP, 07, 2013080606, , BEST, 0, 133N, 1406W, 35, 1006, TS, 34, NEQ, 35, 0, 0, 0, 1010, 150, 30, 0, 0, E, 0, , 0, 0, GIL, D,

[Kingarabian]

ZCZC HFOTCDCP2 ALL
TTAA00 PHFO DDHHMM

TROPICAL STORM GIL DISCUSSION NUMBER 28
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP072013
1100 PM HST MON AUG 05 2013

DEEP CONVECTION HAS SPREAD BACK OVER THE LOW LEVEL CENTER AFTER IT
BRIEFLY BECAME PARTLY EXPOSED DURING THE AFTERNOON. SUBJECTIVE
DVORAK SYNOPTIC TIME FIXES RANGED FROM 1.5 TO 2.5. LIGHTNING
OBSERVATIONS SHOW CONTINUOUS ACTIVITY OVER THE PAST FEW HOURS. AN
OSCAT PASS SEVERAL HOURS AGO SHOWED 30 TO 35 KT WINDS NORTHEAST OF
THE CENTER. GIVEN THE IMPROVEMENT IN APPEARANCE OF GIL ON SATELLITE
IMAGERY...I HAVE MADE THE INITIAL INTENSITY 35 KT.

MODEL GUIDANCE SUGGESTS FAIRLY LIGHT EASTERLY DEEP LAYER FLOW WILL
CONTINUE AROUND GIL. THE TRACK GUIDANCE STARTS OUT PRETTY TIGHTLY
CLUSTERED BUT STARTS TO DIVERGE QUITE A BIT AFTER 48 HOURS.
HOWEVER...THE GENERAL TREND SHOWS GIL MOVING SLIGHTLY SOUTH OF WEST
THROUGH TOMORROW...THEN SLIGHTLY NORTH OF WEST THROUGH THURSDAY...
THEN STRAIGHT WEST. I HAVE FOLLOWED THAT CONSENSUS.

THE FORECAST TRACK KEEPS GIL OVER 80 DEGREE FAHRENHEIT WATER AND
MOVING THROUGH AN AREA WITH ONLY LIGHT SHEAR. GIVEN THE CURRENT
TREND IN THE APPEARANCE OF GIL ON SATELLITE IMAGERY AND THE
GENERALLY FAVORABLE ENVIRONMENT I HAVE FORECAST A SLOW
INTENSIFICATION THROUGH SATURDAY.

FORECAST POSITIONS AND MAX WINDS

INIT 06/0900Z 13.3N 141.0W 35 KT 40 MPH
12H 06/1800Z 13.2N 142.0W 35 KT 40 MPH
24H 07/0600Z 13.2N 143.3W 40 KT 45 MPH
36H 07/1800Z 13.5N 144.8W 40 KT 45 MPH
48H 08/0600Z 13.8N 146.4W 45 KT 50 MPH
72H 09/0600Z 14.5N 149.7W 45 KT 50 MPH
96H 10/0600Z 14.5N 153.0W 50 KT 60 MPH
120H 11/0600Z 14.5N 155.5W 50 KT 60 MPH

$$
FORECASTER DONALDSON

NNNN

[Kingarabian]

Interesting how the NHC posted that discussion on behalf of the CPC.

[Cyclenall]

Gil may not been done after all.

It appears Gil has some tricks up her selves, this is an unexpected turn of events. Gil was left for dead (I stopped watching long ago) but now I think an interesting set of events could come forth in the Cpac if this latest advisory is on to something. Maybe even become the most interesting (TC) in a long while...didn't see that one.

I find it amusing that this is yet another Epac/Cpac TC that has a huge shift in forecast suddenly that was seemingly clear cut. For Henriette, it was a weak TS forecast and now hurricane...Gil was expected to become a remnant low and now not only survive, but become a moderate TS again? Whatever it is, I like it . The last NHC discussion and forecast left it at 30 knots the whole 120 hours...a "we don't know and want this off our hands" one. Totally new direction and lease on life for Gil says CPHC. Is Nash still at the Cpac? His discussions are the best bar none.

Interesting how the NHC posted that discussion on behalf of the CPC.

There are actually a couple of odd things about this, it was still on the NHC site but the advisories were all there and looked to be from the CPHC and on top of that, the 2nd last package...that is the first time ever that I know of the NHC doing advisories of a tropical cyclone beyond 140ºW...why they did it I don't know.

[RL3AO]

There are actually a couple of odd things about this, it was still on the NHC site but the advisories were all there and looked to be from the CPHC and on top of that, the 2nd last package...that is the first time ever that I know of the NHC doing advisories of a tropical cyclone beyond 140ºW...why they did it I don't know.

Basically the cycle for a new advisory starts at 0/6/12/18z but the actual advisory isn't issued until 3/9/15/21z. When the NHC started the advisory cycle at 0000z, Gil was still in the East Pacific. By the time 0300z came and they issued the advisory, it had entered the Central Pacific. Thats the reason.

[galaxy401]

Wow I'm impressed. Gil isn't done yet and now they forecast it to very slowly strengthen in the next five days. How far will he go?

[Kingarabian]

Well, convection is waning right now. Henriette is returning the favor.

[galaxy401]

...And so much for that. Went poof. Seems the forecasters aren't sure how this storm is going to behave.

[Yellow Evan]

Does the CPHC plan on releasing an advisory?

[Alyono]

amateur hour at CPHC. Only way to describe not issuing advisories

[Cyclenall]

amateur hour at CPHC. Only way to describe not issuing advisories

Yeah I was very confused when I checked a hour ago to find no new advisory...like what? Well at least we're making some history...CPHC foolin' around right now . They made a new track map and maybe several other products but the text, screw it. Maybe Nash wasn't available so they determined to either wait for him, or not do one .

[supercane4867]

Advisory come nearly four hours late, nice job CPHC

Tropical Depression GIL Advisory Number 30...RESENT
Issued at 1100 AM HST TUE AUG 06 2013
SUMMARY OF 1100 AM HST...2100 UTC...INFORMATION
-----------------------------------------------
Location: 13.4N 141.9W
ABOUT 975 MI...1570 KM ESE OF HILO HAWAII
ABOUT 1185 MI...1910 KM ESE OF HONOLULU HAWAII
Maximum sustained winds: 35 MPH...55 KM/H
Present movement: WNW or 285 degrees AT 9 MPH...15 KM/H
Minimum central pressure: 1008 MB...29.77 INCHES

Down to TD again

[HURAKAN]

the advisory was available at WU, I'm guessing CPHC had a software problem

[Kingarabian]

I apologize on behalf of the State of Hawaii. Disgusting.

[Yellow Evan]

amateur hour at CPHC. Only way to describe not issuing advisories

Yeah I was very confused when I checked a hour ago to find no new advisory...like what? Well at least we're making some history...CPHC foolin' around right now . They made a new track map and maybe several other products but the text, screw it. Maybe Nash wasn't available so they determined to either wait for him, or not do one .

Nah, IMD owns that record.

[Yellow Evan]

the advisory was available at WU, I'm guessing CPHC had a software problem

Well, they seem to have software issues quite often. And even then, it's the NHC's job to issue advisories when the CPHC is down. Maybe the CPHC's software was so bad that they could not even notify the NHC.