CPAC: OHO - Post-Tropical

[NotoSans]

07C OHO 151004 1200 13.3N 154.9W CPAC 35 1001

ASCAT shows no gale force winds near the circulation center. I would say it's a tropical depression.

[wxman57]

ASCAT indicates max winds 20-25 kts a few hours ago. Center around 13.2N/153.4W.

[Alyono]

that ASCAT shows beyond a shadow of a doubt that this is a TD

[Yellow Evan]

Pretty sure this is one of those 20 knot TD's know.

[supercane]

WTPA42 PHFO 041502
TCDCP2

TROPICAL STORM OHO DISCUSSION NUMBER 6
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP072015
500 AM HST SUN OCT 04 2015

SHOWERS AND THUNDERSTORMS HAVE BEEN STEADILY RE-DEVELOPING AND
INTENSIFYING NEAR THE CENTER OF OHO OVER THE PAST SEVERAL HOURS...
WHILE THE SYSTEM HAS BECOME INCREASINGLY SEPARATED FROM THE
DEEP CONVECTION WELL TO THE SOUTHEAST. THUS OHO IS ONCE AGAIN
TAKING ON THE APPEARANCE OF A TYPICAL TROPICAL CYCLONE...RATHER
THAN THAT OF A MONSOON DEPRESSION. DVORAK CURRENT INTENSITY
ESTIMATES ARE 2.5/35 KT FROM PGTW AND 2.0/30 KT FROM PHFO AND SAB.
THE MULTI-PLATFORM SATELLITE SURFACE WIND ANALYSES FROM RAMMB/CIRA
ANALYZED AN AREA OF 35 KT WINDS TO THE NORTHEAST OF THE
CENTER...WITH A MAX WIND OF 44 KT...WHILE SATCON AND ADT ANALYSES
FROM UW-CIMSS INDICATE AN INTENSITY NEAR 40 KT. BASED ON A BLEND OF
THIS DATA...THE INITIAL INTENSITY FOR THIS ADVISORY HAS BEEN
MAINTAINED AT 35 KT.

A COMPLEX PATTERN ALOFT CURRENTLY HAS OHO IN AN ENVIRONMENT OF
EASTERLY SHEAR...ON THE ORDER OF ABOUT 10-15 KT...ACCORDING TO
UW-CIMSS AND SHIPS ANALYSES...WITH THE CENTER ESTIMATED TO BE JUST
EAST OF THE DEEP CONVECTION. WITH OHO SOUTH OF A WEAK MID-LEVEL
RIDGE THAT EXTENDS WESTWARD FROM A HIGH IN THE EASTERN PACIFIC...AND
THE SYSTEM APPARENTLY RE-GAINING VERTICAL DEPTH...IT HAS BEEN MOVING
WEST-NORTHWESTWARD...285/06 KT...SINCE THE PREVIOUS ADVISORY. AS OHO
HAS BEEN IN AN AREA OF WEAK AND VARIABLE STEERING CURRENTS...
FORECASTING WHAT HAS BEEN AN ERRATIC MOTION OVER THE PAST 24 TO 36
HOURS HAS BEEN A CHALLENGE.

HAVING SAID THAT...THE UPDATED TRACK FORECAST CALLS FOR SLOW-MOVING
OHO TO CONTINUE MOVING TOWARD THE WEST-NORTHWEST TODAY BEFORE
TURNING TOWARD THE NORTHWEST BY TONIGHT...STEERED BY THE
AFOREMENTIONED RIDGE. A TURN TOWARD THE NORTH AND THEN NORTHEAST...
WITH AN INCREASE IN FORWARD SPEED...IS EXPECTED TO GRADUALLY
COMMENCE ON MONDAY AND CONTINUE THROUGH THE END OF THE FORECAST
PERIOD. THIS OCCURS AS A VIGOROUS SHORTWAVE TROUGH DIGS SOUTHWARD
INTO A PERSISTENT LONGWAVE TROUGH THAT IS NORTH OF HAWAII...AND
ERODES THE RIDGE. THE DIGGING TROUGH WILL BRING AN INCREASING
SOUTHWESTERLY STEERING FLOW THAT WILL ACCELERATE OHO TOWARD THE
NORTHEAST ON DAYS 4 AND 5. THE UPDATED FORECAST IS SIMILAR TO THE
PREVIOUS...AND IS CLOSE TO THE GFEX...BUT NOT AS FAST IN THE LATER
PERIODS. GREATER WEIGHT IS PLACED ON THE GFS VERSUS THE
ECMWF...WHICH INDICATES A MUCH FASTER MOTION TO THE NORTHEAST ON
DAYS 4 AND 5. THE GFS IS SLOWER WITH THE FORWARD MOTION OF OHO IN
THE LATER PERIODS AS IT INTERACTS WITH A DEVELOPING AREA OF LOW
PRESSURE TO ITS EAST. WHILE THE DEVELOPMENT OF THIS LOW MAY SEEM
SOMEWHAT SPURIOUS...LATEST SATELLITE IMAGES INDICATE PERSISTENT DEEP
CONVECTION IN AN AREA THAT THE GFS INSISTS WILL SPAWN A TROPICAL
LOW.

THE LATEST INTENSITY GUIDANCE INDICATES THAT OHO WILL HAVE A
DIFFICULT TIME BECOMING A HURRICANE...DESPITE SUFFICIENTLY WARM SEA
SURFACE TEMPERATURES ALONG THE FORECAST TRACK OVER THE NEXT COUPLE
OF DAYS. MODERATE EASTERLY SHEAR OVER THE NEXT TWO DAYS IS EXPECTED
TO BE A LIMITING FACTOR BEFORE STRONGER SOUTHWESTERLY SHEAR ON DAYS
3 TO 5 LEADS TO A WEAKENING TREND. THE INTENSITY FORECAST IS CLOSE
TO THE IVCN AND NOW DOES NOT FORECAST OHO TO BECOME A HURRICANE. AN
ASCAT PASS AROUND 0758Z INDICATED THAT ALTHOUGH STRONG WESTERLY
WINDS ARE STILL RACING BY TO THE SOUTH AND SOUTHEAST OF OHO...THESE
WINDS HAVE WEAKENED. AS OPPOSED TO WHEN OHO HAD THE APPEARANCE OF A
MONSOON GYRE YESTERDAY...THESE WINDS WILL NO LONGER BE CONSIDERED
DIRECTLY RELATED TO THE CIRCULATION OF THE CYCLONE. THEREFORE THE
LARGE TROPICAL STORM FORCE RADII IN THE SOUTHERN SEMICIRCLE THAT
WERE INDICATED IN THE PREVIOUS COUPLE OF ADVISORIES HAVE BEEN
REDUCED DRAMATICALLY.

THE 53RD WEATHER RECONNAISSANCE SQUADRON HAS BEEN TASKED TO FLY THIS
SYSTEM IN SUPPORT OF CPHC OPERATIONS. INITIAL FLIGHTS INTO THE
SYSTEM ARE PLANNED FOR THIS EVENING AND MONDAY MORNING. THE G-IV
AIRCRAFT IS ALSO HEADING TO HAWAII TO FLY SYNOPTIC MISSIONS...WITH
HIGH-ALTITUDE FLIGHTS PLANNED FOR THE NEXT TWO DAYS.


FORECAST POSITIONS AND MAX WINDS

INIT 04/1500Z 13.5N 155.2W 35 KT 40 MPH
12H 05/0000Z 13.8N 155.3W 40 KT 45 MPH
24H 05/1200Z 14.3N 155.2W 45 KT 50 MPH
36H 06/0000Z 15.0N 154.5W 50 KT 60 MPH
48H 06/1200Z 16.0N 153.4W 55 KT 65 MPH
72H 07/1200Z 17.6N 151.4W 60 KT 70 MPH
96H 08/1200Z 20.5N 148.5W 55 KT 65 MPH
120H 09/1200Z 25.0N 146.0W 50 KT 60 MPH

$$

FORECASTER BIRCHARD

[Alyono]

new GFS (I think the first with synoptic surveillance) has shifted to the left. Still well east of the islands. Difference is, it is now showing a northward motion, not a continued NE motion

[CrazyC83]

No mention of the ASCAT pass in the discussion...did it come out too late for them? I'd have lowered it to a generous 30 kt.

[supercane]

What synoptic surveillance? No recon has flown into or around Oho yet. See PODs from yesterday and today.

Code: Select all

000
NOUS42 KNHC 031405
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1000 AM EDT SAT 03 OCTOBER 2015
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
         VALID 04/1100Z TO 05/1100Z OCTOBER 2015
         TCPOD NUMBER.....15-130

I.  ATLANTIC REQUIREMENTS
    1. HURRICANE JOAQUIN
       FLIGHT ONE -- TEAL 71           FLIGHT TWO -- TEAL 72
       A. 04/2330Z                     A. 05/1130Z
       B. AFXXX 1611A JOAQUIN          B. AFXXX 1711A JOAQUIN
       C. 04/2000Z                     C. 05/0830Z
       D. 33.0N 66.9W                  D. 35.0N 65.5W
       E. 04/2300Z TO 05/0200Z         E. 05/1100Z TO 05/1400Z
       F. SFC TO 10,000FT              F. SFC TO 10,000FT

    2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.
    3. REMARKS: NASA WB-57(NASA 928) WILL FLY A 6HR RESEARCH MISSION
       AROUND JOAQUIN SUNDAY. TAKEOFF FROM WARNER-ROBINS
       WILL BE AT 04/1500Z. FLIGHT LEVELS 55,000-65,000FT.
       ANTICIPATING 71 DROPS.

II. PACIFIC REQUIREMENTS
    1. TROPICAL STORM OHO
       FLIGHT ONE -- NOAA 49           FLIGHT TWO -- TEAL76
       A. 05/0000Z                     A. 05/0600Z
       B. NOAA9 0107C OHO              B. AFXXX 0207C OHO
       C. 04/1730Z                     C. 05/0300Z
       D. NA                           D. 15.8N 155.9W
       E. NA                           E. 05/0500Z TO 05/0800Z
       F. 41,000 TO 45,000FT           F. SFC TO 10,000FT

    2. SUCCEEDING DAY OUTLOOK: A G-IV SYNOPTIC SURVEILLANCE MISSION
       DEPARTING AT 05/1730Z. A FIX AT 05/1800Z WITH PROBABLE
       6-HRLY FIXES BEGINNING AT 06/0600Z.

$$
JWP


Code: Select all

000
NOUS42 KNHC 041525
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1130 AM EDT SUN 04 OCTOBER 2015
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
         VALID 05/1100Z TO 06/1100Z OCTOBER 2015
         TCPOD NUMBER.....15-131

I.  ATLANTIC REQUIREMENTS
    1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
    2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.
    3. REMARKS:
       A. NASA WB-57(NASA 928) WILL FLY A 6HR RESEARCH MISSION
       AROUND JOAQUIN MONDAY. TAKEOFF FROM WARNER-ROBINS
       WILL BE AT 05/1500Z. FLIGHT LEVELS 55,000-65,000FT.
       ANTICIPATING 82 DROPS.
       B. FIX MISSION FOR 05/1130Z CANCELED BY NHC AT 04/1415Z.

II. PACIFIC REQUIREMENTS
    1. TROPICAL STORM OHO
       FLIGHT ONE -- TEAL 77           FLIGHT TWO -- NOAA 49           
       A. 05/1800Z                     A. 06/0000Z                     
       B. AFXXX 0307C OHO              B. NOAA9 0407C OHO             
       C. 05/1600Z                     C. 05/1730Z                     
       D. 14.7N 154.9W                 D. NA                           
       E. 05/1730Z TO 05/2030Z         E. NA                           
       F. SFC TO 10,000FT              F. 41,000 TO 45,000FT 

       FLIGHT THREE -- TEAL 78
       A. 06/0600Z 
       B. AFXXX 0507C OHO
       C. 06/0330Z
       D. 15.5N 153.9W
       E. 06/0500Z TO 06/0800Z
       F. SFC TO 10,000FT

    2. SUCCEEDING DAY OUTLOOK:CONTINUE 12-HRLY FIXES.


[Alyono]

the POD from Friday mentioned a surveillance flight for today at 6Z, as have the TCDs

[Alyono]

http://www.prh.noaa.gov/cphc/tcpages/ar ... 1510040255

"THE G-IV
AIRCRAFT IS ALSO HEADING TO HAWAII TO FLY SYNOPTIC MISSIONS...WITH
HIGH-ALTITUDE FLIGHTS PLANNED FOR SUNDAY AND MONDAY MORNINGS...IN
ORDER FOR THE DATA TO BE UTILIZED BY AFTERNOON MODEL RUNS."

[CrazyC83]

Remember it is 6 hours earlier in Hawaii so the 18Z and 00Z timeframes represent daytime.

[Alyono]

No mention of the ASCAT pass in the discussion...did it come out too late for them? I'd have lowered it to a generous 30 kt.

exactly what I lowered the winds to, and only because I was in a charitable mood

[Alyono]

Think 157W is going to be the key longitude. If this remains east of 157, going well east of Hawaii. West of 157 would likely bring it closer.

Also, the CMC is on something as it has a near miss in less than 48 hours. This isn't going straight north

[Yellow Evan]

Since when is the CMC reliable?

[supercane]

First recon flights into Oho are on route, with Gonzo southwest of the Channel Islands (California) and synoptic mission nearing halfway mark to Hawaii.

[Kingarabian]

No idea how this is still a TS.

[supercane]

CPHC keeps Oho a TS.

WTPA32 PHFO 042041
TCPCP2

BULLETIN
TROPICAL STORM OHO ADVISORY NUMBER 7
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP072015
1100 AM HST SUN OCT 04 2015

...TROPICAL STORM OHO MOVING NORTH SLOWLY SOUTH OF HAWAII...

SUMMARY OF 1100 AM HST...2100 UTC...INFORMATION
-----------------------------------------------
LOCATION...13.6N 154.9W
ABOUT 375 MI...605 KM S OF SOUTH POINT HAWAII
ABOUT 565 MI...915 KM SSE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES

WTPA42 PHFO 042044
TCDCP2

TROPICAL STORM OHO DISCUSSION NUMBER 7
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP072015
1100 AM HST SUN OCT 04 2015

OVERALL SYSTEM ORGANIZATION HAS IMPROVED A BIT SINCE LAST
NIGHT...WITH THE LOW LEVEL CIRCULATION CENTER...LLCC...LOCATED ON
THE EASTERN EDGE OF DEEP CONVECTION. ADDITIONAL RAINBANDS ARE
FORMING ACROSS THE NORTHEAST QUADRANT...AND ANIMATION OF THESE IN
THE FEW VISIBLE IMAGES AVAILABLE INCREASES FIX CONFIDENCE.
SUBJECTIVE DVORAK SATELLITE INTENSITY ESTIMATES RANGE FROM 2.0...30
KT...FROM PHFO AND SAB TO 2.5...35 KT...FROM JTWC. UW-CIMSS ADT WAS
HIGHEST AT 2.7...39 KT. THE BEST CHOICE FOR INITIAL INTENSITY IS A
BLEND OF THESE...AND WE WILL KEEP OHO AS A 35 KT TROPICAL STORM FOR
THIS ADVISORY.

OHO CONTINUES TO MEANDER TO THE SOUTH OF THE HAWAIIAN ISLANDS THIS
MORNING...AND THE INITIAL MOTION OF 360/02 KT MAY BE JUST A SNAPSHOT
OF THIS MEANDERING. UW-CIMSS AND SHIPS ANALYSIS SHOW EASTERLY SHEAR
ACROSS OHO RANGES FROM 10 TO 15 KT...SO IT MAKES SENSE THAT
ASSOCIATED DEEP CONVECTION LIES WEST OF THE LLCC AND THAT THE CORE
IS TILTED TOWARD THE WEST WITH HEIGHT. THIS TILTING ADDS
UNCERTAINTY TO MOTION IN SPITE OF VISIBLE IMAGE ANIMATION. STEERING
INFLUENCES ARE WEAK AND INCLUDE A MID-LEVEL RIDGE WHICH EXTENDS
WESTWARD FROM THE EASTERN PACIFIC AND THE FIRST GENTLE NUDGES FROM A
DEEP TROUGH DEVELOPING NORTHWEST OF THE HAWAIIAN ISLANDS. WHILE
FORECAST TRACK GUIDANCE REMAINS CLUSTERED AROUND NORTHERLY MOTION
TODAY BECOMING NORTHEASTERLY MOTION MONDAY AND AFTERWARDS...FORWARD
SPEED BETWEEN MODELS VARIES WIDELY...WITH ECMWF DEPICTING LONG RANGE
FORWARD SPEED ABOUT DOUBLE WHAT GFS DEPICTS. THIS IS LIKELY DUE TO
DIFFERENCES IN HOW EACH MODEL SEES THE INTERACTION BETWEEN OHO AND
THE EXPECTED DEEP TROUGHING NORTH OF HAWAII BEYOND 48 HOURS...AND
WITH THE INTERACTION WITH ANOTHER LOW FARTHER TO THE EAST. THE
CURRENT FORECAST TRACK CLOSELY ALIGNS WITH THE PREVIOUS ONE THROUGH
72 HOURS...THEN IS ADJUSTED TO THE LEFT AT 96 AND 120 HOURS TO
REMAIN WITHIN THE CONSENSUS ENVELOPE.

INTENSITY GUIDANCE CONTINUES TO INDICATE THAT OHO WILL REMAIN A
TROPICAL STORM THROUGH THE FORECAST PERIOD...IN SPITE OF MOVING
ACROSS 28C TO 29C WATER THROUGH 48 HOURS. SHEAR IS EXPECTED TO
INCREASE DRAMATICALLY ACROSS OHO BEYOND 48 HOURS AS THE DEEP TROUGH
NORTH OF HAWAII DIGS SOUTHEASTWARD AND BEGINS TO SCOOP THIS SYSTEM
OUT OF THE DEEP TROPICS. HOWEVER...SOME STRENGTHENING IS EXPECTED
UNTIL THEN AS SHEAR REMAINS MODERATE TODAY...THEN ACTUALLY
DECREASES TEMPORARILY MONDAY. THE INTENSITY TREND FOR THIS ADVISORY
CLOSELY FOLLOWS THE PREVIOUS ONE...BUT CAPS INTENSITY AT 55 KT.
THIS IS SLIGHTLY HIGHER THAN SHIPS BUT BELOW HWRF AND GFDL.

THE 53RD WEATHER RECONNAISSANCE SQUADRON HAS BEEN TASKED TO FLY THIS
SYSTEM IN SUPPORT OF CPHC OPERATIONS. INITIAL FLIGHTS INTO THE
SYSTEM ARE PLANNED FOR THIS EVENING AND MONDAY MORNING.
ADDITIONALLY...THE G-IV AIRCRAFT WILL FLY SYNOPTIC MISSIONS...WITH
A HIGH-ALTITUDE FLIGHT PLANNED MONDAY MORNING...IN ORDER FOR THE
DATA TO BE UTILIZED BY AFTERNOON MODEL RUNS.


FORECAST POSITIONS AND MAX WINDS

INIT 04/2100Z 13.6N 154.9W 35 KT 40 MPH
12H 05/0600Z 14.0N 155.0W 40 KT 45 MPH
24H 05/1800Z 14.6N 154.6W 45 KT 50 MPH
36H 06/0600Z 15.5N 153.8W 50 KT 60 MPH
48H 06/1800Z 16.3N 152.7W 55 KT 65 MPH
72H 07/1800Z 18.3N 150.5W 55 KT 65 MPH
96H 08/1800Z 22.0N 148.3W 55 KT 65 MPH
120H 09/1800Z 26.2N 146.2W 50 KT 60 MPH

$$
FORECASTER POWELL

Recon getting close, with synoptic plane perhaps about to stop for refuel before mission, and Gonzo past 2/3 mark from California to Hawaii.

[Alyono]

seeing some rotation closer to 155.7W. Cannot tell though

if it is, this is organizing as forecast

edit... microwave is saying that this may be the case as at 17Z, this was around 155.2 and SW of CPHC (and SW of my latest position). I hate these monsoon systems. I am struggling to pick the center

https://www.fnmoc.navy.mil/tcweb/cgi-bi ... 99C.INVEST,

[Alyono]

on ASCAT, maybe closer to 155.3. Winds are also quite a bit higher than they were in the previous ASCAT pass. Several 30 kt vectors

[Kingarabian]

Deep cold tops continue to be pushed off and I don't see any signs of organization anytime soon. People have been complaining about models being inconsistent. Talk about these shear charts. They've over done it and under done it all season long.

We also need better understanding about the shear in a specific area. Some shear, despite it being diagnosed as below moderate in the 10kt area, still has the power to disrupt as if it were strong shear (20kt +).