EPAC: Tropical Depression JULIETTE

[CrazyC83]

Current Intensity Analysis




UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 30 SEP 2007 Time : 140000 UTC
Lat : 18:20:26 N Lon : 112:58:13 W


CI# /Pressure/ Vmax
3.3 / 996.4mb/ 51.0kt


6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
3.3 3.3 3.5 3.5

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -64.4C Cloud Region Temp : -65.9C

Scene Type : UNIFORM CDO CLOUD REGION

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : 0.7T/6hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

****************************************************

[HurricaneRobert]

It looks better than the 40 knots NHC has it at.

[cycloneye]

417
WTPZ44 KNHC 301435
TCDEP4
TROPICAL STORM JULIETTE DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142007
800 AM PDT SUN SEP 30 2007

CENTER FIXES ARE UNCERTAIN SO THE INITIAL POSITION AND MOTION
ESTIMATES WEIGH HEAVILY ON CONTINUITY. SINCE THE LOCATION OF THE
CENTER IS NOT WELL KNOWN...THIS ALSO LENDS UNCERTAINTY TO THE
ESTIMATED INTENSITY. IF THE CENTER IS WELL-EMBEDDED WITHIN THE
DEEP CONVECTION...THEN THE WINDS COULD BE CLOSE TO 45 KT AS GIVEN
BY THE DVORAK ESTIMATES. HOWEVER IF THE CENTER IS NEAR THE EDGE OF
THE CONVECTION...JULIETTE IS A WEAKER STORM. THE CURRENT INTENSITY
IS SET AT 40 KT AS A COMPROMISE. THERE IS A SMALL WINDOW OF
OPPORTUNITY FOR STRENGTHENING SO THE OFFICIAL FORECAST SHOWS A
SLIGHT INTENSIFICATION TODAY...SIMILAR TO THAT INDICATED BY THE
SHIPS LGEM GUIDANCE. WITHIN 24 HOURS OR SO...HOWEVER...JULIETTE
WILL BE MOVING INTO AN ENVIRONMENT OF COOLER WATERS AND MORE STABLE
AIR. WEAKENING TO A REMNANT LOW IS LIKELY WITHIN 72 HOURS OR
SOONER.

INITIAL MOTION IS ESTIMATED AT 335/10. JULIETTE CONTINUES TO
PROCEED NORTH-NORTHWESTWARD IN THE FLOW BETWEEN A MID-LEVEL RIDGE
OVER MEXICO AND A TROUGH EXTENDING SOUTHWARD FROM CALIFORNIA. THIS
REGIME IS EXPECTED TO CONTINUE FOR THE NEXT DAY OR TWO. LATER IN
THE PERIOD...AS THE CYCLONE LOSES ITS DEEP CONVECTION...THE
INCREASINGLY SHALLOW SYSTEM IS LIKELY TO BE STEERED PRIMARILY BY
THE LOWER-TROPOSPHERIC FLOW. SINCE THE GLOBAL MODELS INDICATE THAT
THIS LOW-LEVEL FLOW WILL BE QUITE WEAK...THE OFFICIAL FORECAST KEEP
THE DISSIPATING CYCLONE STATIONARY IN 2-3 DAYS. THIS IS SIMILAR TO
THE PREVIOUS NHC FORECAST AND NOT FAR FROM THE CONSENSUS OF THE
TRACK MODELS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 30/1500Z 18.7N 113.0W 40 KT
12HR VT 01/0000Z 19.9N 113.6W 45 KT
24HR VT 01/1200Z 21.7N 114.4W 40 KT
36HR VT 02/0000Z 23.0N 115.1W 35 KT
48HR VT 02/1200Z 23.5N 115.5W 30 KT
72HR VT 03/1200Z 23.5N 115.5W 20 KT...REMNANT LOW
96HR VT 04/1200Z...DISSIPATED

$$
FORECASTER PASCH

[CrazyC83]

It looks better than the 40 knots NHC has it at.

I agree, it looks more like 45-50 knots.

[Chacor]

ATCF up to 50 kts.

[cycloneye]

755
WTPZ44 KNHC 302104
TCDEP4
TROPICAL STORM JULIETTE DISCUSSION NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142007
200 PM PDT SUN SEP 30 2007

VISIBLE SATELLITE IMAGERY SUGGEST THAT THE CENTER IS WELL-EMBEDDED
IN THE DENSE OVERCAST...WITH SOME HINTS OF INNER BANDING FEATURES.
JULIETTE WAS PROBABLY A LITTLE STRONGER EARLIER TODAY...NEAR 50 KT.
HOWEVER ON RECENT IMAGES THE CLOUD TOPS ARE SEEN TO BE WARMING...SO
THE CURRENT INTENSITY IS ADJUSTED TO 45 KT. THE SYSTEM MAY ALREADY
BE PAST PEAK INTENSITY AND IS HEADED FOR A MORE STABLE AIR MASS AND
COOLER SEA SURFACE TEMPERATURES. THE FORECAST CALLS FOR WEAKENING
TO REMNANT LOW STATUS IN 2-3 DAYS...ALTHOUGH THIS EVENT COULD OCCUR
SOONER IF DEEP CONVECTION DOES NOT REDEVELOP IN THE CYCLONE. IN
FACT...THE GFDL AND HWRF MODEL RUNS WEAKEN JULIETTE MORE RAPIDLY
THAN INDICATED HERE.

BASED ON VISIBLE IMAGES...THE CENTER HAS BEEN RELOCATED A LITTLE TO
THE WEST OF THE PREVIOUS TRACK. HOWEVER THE MOTION IS STILL
ESTIMATED TO BE TOWARD THE NORTH-NORTHWEST OR 330/11. JULIETTE IS
BEING STEERED BY THE FLOW BETWEEN A LOW- TO MID-LEVEL RIDGE OVER
MEXICO AND A WEAKENING MID-LEVEL TROUGH TO THE WEST AND NORTHWEST
OF THE TROPICAL CYCLONE. AS THE STORM LOSES ITS DEEP CONVECTION
AND BECOMES A SHALLOWER CIRCULATION IN A COUPLE OF DAYS...IT SHOULD
BE STEERED PRIMARILY BY THE LOWER-TROPOSPHERIC FLOW TO THE WEST OF
THE BAJA CALIFORNIA PENINSULA. THIS FLOW IS FORECAST BY THE GLOBAL
TO BE VERY WEAK...SO THE OFFICIAL TRACK FORECAST SHOWS VERY LITTLE
MOTION IN 2-3 DAYS. THE FORECAST TRACK LEANS TOWARD THE SHALLOW
BAM FORECAST BUT IS SOMEWHAT SLOWER.

FORECAST POSITIONS AND MAX WINDS

INITIAL 30/2100Z 19.7N 113.9W 45 KT
12HR VT 01/0600Z 21.2N 114.6W 45 KT
24HR VT 01/1800Z 22.6N 115.3W 40 KT
36HR VT 02/0600Z 23.6N 115.8W 35 KT
48HR VT 02/1800Z 24.2N 116.2W 30 KT
72HR VT 03/1800Z 24.5N 116.5W 20 KT...REMNANT LOW
96HR VT 04/1800Z...DISSIPATED

$$
FORECASTER PASCH

[cycloneye]

863
WTPZ44 KNHC 010245
TCDEP4
TROPICAL STORM JULIETTE DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142007
800 PM PDT SUN SEP 30 2007

DEEP CONVECTION HAS BEEN SPORADIC DURING THE PAST SEVERAL
HOURS...BUT IT PERSISTS AND THE MOST RECENT BURST EXHIBITS CLOUD
TOPS COLDER THAN -80C. THE LOW-LEVEL CENTER IS OBSCURED AND HARD
TO PRECISELY LOCATE...MAKING SATELLITE CLASSIFICATIONS FAIRLY
UNCERTAIN AND DISPARATE...WITH 00Z INTENSITY ESTIMATES RANGING FROM
45 TO 55 KT. THE ADVISORY INTENSITY REMAINS 45 KT GIVEN THE
INCONSISTENT CONVECTIVE PATTERN. ALONG THE FORECAST TRACK...THE
SOUTHERLY WIND SHEAR WILL CONTINUE AS THE CYCLONE PASSES OVER
PROGRESSIVELY COOLER WATERS...SO A WEAKENING TREND APPEARS
IMMINENT. THE NEW OFFICIAL INTENSITY FORECAST CALLS FOR A SLIGHTLY
FASTER PACE OF DECLINE THAN THE PREVIOUS ONE...AND IS CLOSE TO A
CONSENSUS OF THE VARIOUS INTENSITY GUIDANCE MODELS.

JULIETTE HAS RECENTLY BEEN MOVING NORTHWESTWARD OR ROUGHLY
320/9...IN BETWEEN A LOW- TO MID-LEVEL RIDGE OVER MEXICO AND A
MID-LEVEL TROUGH TO ITS WEST. AS THE CYCLONE SPINS DOWN IT SHOULD
DECELERATE IN THE WEAK LOWER-LEVEL FLOW WEST OF THE BAJA CALIFORNIA
PENINSULA. THE NEW TRACK FORECAST TAKES JULIETTE AND ITS EVENTUAL
REMNANT LOW ON A PATH THAT BENDS SLIGHTLY TO THE RIGHT...ALONG THE
LEFT SIDE OF THE TRACK GUIDANCE ENVELOPE...AND COMES ESSENTIALLY TO
A HALT IN A FEW DAYS AROUND THE TIME OF DISSIPATION.


FORECAST POSITIONS AND MAX WINDS

INITIAL 01/0300Z 20.2N 114.7W 45 KT
12HR VT 01/1200Z 21.6N 115.4W 40 KT
24HR VT 02/0000Z 22.9N 116.0W 35 KT
36HR VT 02/1200Z 23.8N 116.3W 30 KT
48HR VT 03/0000Z 24.2N 116.4W 25 KT...DISSIPATING
72HR VT 04/0000Z 24.5N 116.5W 20 KT...REMNANT LOW
96HR VT 05/0000Z...DISSIPATED

$$
FORECASTER KNABB

[cycloneye]

000
WTPZ44 KNHC 010831
TCDEP4
TROPICAL STORM JULIETTE DISCUSSION NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142007
200 AM PDT MON OCT 01 2007

A SEQUENCE OF MICROWAVE PASSES BETWEEN 00Z AND 04Z SUGGEST THAT THE
CENTER OF JULIETTE IS A LITTLE EAST OF THE PREVIOUS TRACK...AND
LAGGING BEHIND THE DEEP CONVECTION. A QUIKSCAT PASS AT 02Z ALSO
PLACED THE CENTER ON THE SOUTHEAST EDGE OF THE CONVECTION. THE
QUIKSCAT DATA INCLUDED A 50 KT VECTOR THAT MIGHT HAVE BEEN
VALID...BUT GIVEN THAT THE CENTER AND THE CONVECTION SEEM TO BE
SEPARATING...I'D PREFER TO KEEP THE ADVISORY INTENSITY AT 45 KT.
ALONG THE FORECAST TRACK...SOUTHERLY WIND SHEAR WILL CONTINUE AS
THE CYCLONE PASSES OVER PROGRESSIVELY COOLER WATERS...SO A
WEAKENING TREND APPEARS IMMINENT. THE OFFICIAL FORECAST FOLLOWS
THE PREVIOUS ADVISORY AND THE LGEM STATISTICAL MODEL.

WITH THE EASTWARD ADJUSTMENT OF THE TRACK...THE INITIAL MOTION
ESTIMATE IS 330/9. THE TRACK FORECAST PHILOSOPHY IS UNCHANGED FROM
THE PREVIOUS ADVISORY. JULIETTE HAS RECENTLY BEEN MOVING IN BETWEEN
A LOW- TO MID-LEVEL RIDGE OVER MEXICO AND A MID-LEVEL TROUGH TO ITS
WEST. AS THE CYCLONE SPINS DOWN IT SHOULD DECELERATE IN THE WEAK
LOWER-LEVEL FLOW WEST OF THE BAJA CALIFORNIA PENINSULA. THE
OFFICIAL FORECAST REMAINS ALONG THE LEFT SIDE OF THE TRACK GUIDANCE
ENVELOPE...AND COMES ESSENTIALLY TO A HALT AFTER 36 HOURS AROUND
THE TIME OF DISSIPATION. IF THE CYCLONE SUCCUMBS TO THE SHEAR
EARLIER THAN EXPECTED...AND THIS PROCESS MAY ALREADY BE
BEGINNING...THEN THE STALL WOULD OCCUR EARLIER.


FORECAST POSITIONS AND MAX WINDS

INITIAL 01/0900Z 21.0N 114.8W 45 KT
12HR VT 01/1800Z 22.1N 115.3W 40 KT
24HR VT 02/0600Z 23.2N 115.7W 35 KT
36HR VT 02/1800Z 24.0N 116.0W 30 KT
48HR VT 03/0600Z 24.3N 116.0W 25 KT...REMNANT LOW
72HR VT 04/0600Z 24.5N 116.0W 20 KT...REMNANT LOW
96HR VT 05/0600Z...DISSIPATED

$$
FORECASTER FRANKLIN

[cycloneye]

380
WTPZ44 KNHC 011435
TCDEP4
TROPICAL STORM JULIETTE DISCUSSION NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142007
800 AM PDT MON OCT 01 2007

AN EARLIER AMSR-E MICROWAVE PASS WAS VERY HELPFUL IN FINDING THE
CENTER OF JULIETTE...WHICH IS LOCATED ON THE SOUTHERN EDGE OF A
RATHER LINEAR NORTH TO SOUTH AREA OF DEEP CONVECTION. DVORAK DATA
T-NUMBERS FROM TAFB AND SAB ARE 45 KT AND 35 KT RESPECTIVELY. A
LATE-ARRIVING QUIKSCAT PASS CAUGHT THE EASTERN HALF OF THE
CIRCULATION AND REVEALED SEVERAL BELIEVABLE 35 KT WIND VECTORS.
ASSUMING WINDS ARE SLIGHTLY HIGHER IN THE CONVECTION TO THE NORTH
OF THE CENTER...THE INITIAL INTENSITY IS SET AT 40 KT. SOUTHERLY
SHEAR...COOLER WATERS...AND A MORE STABLE ENVIRONMENT AHEAD OF
JULIETTE ARE EXPECTED TO CONTINUE THE WEAKENING PROCESS AND THE
CYCLONE IS FORECAST TO BECOME A REMNANT LOW IN ABOUT 36 HOURS.

THE INITIAL MOTION IS 325/8. THE TRACK PHILOSOPHY REMAINS
UNCHANGED...AS JULIETTE IS EXPECTED TO CONTINUE MOVING NORTHWESTWARD
FOR THE NEXT DAY OR SO BETWEEN A MID-LEVEL RIDGE OVER MEXICO AND
TROUGH TO ITS WEST. THEREAFTER...AS THE CYCLONE BECOMES
INCREASINGLY SHALLOW...JULIETTE OR ITS REMNANTS ARE EXPECTED TO
DECELERATE IN A VERY WEAK LOW-LEVEL STEERING PATTERN. THE
OFFICIAL FORECAST FOLLOWS THE PREVIOUS ADVISORY EXCEPT FOR A SLIGHT
WESTWARD ADJUSTMENT MADE TO THE INITIAL POSITION BASED ON THE
AMSR-E MICROWAVE DATA.

WIND RADII WERE ADJUSTED IN THE EASTERN SEMICIRCLE BASED ON THE
QUIKSCAT DATA.

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/1500Z 21.7N 115.4W 40 KT
12HR VT 02/0000Z 22.7N 115.9W 35 KT
24HR VT 02/1200Z 23.6N 116.2W 30 KT
36HR VT 03/0000Z 24.2N 116.4W 25 KT...REMNANT LOW
48HR VT 03/1200Z 24.5N 116.4W 25 KT...REMNANT LOW
72HR VT 04/1200Z 24.7N 116.4W 20 KT...REMNANT LOW
96HR VT 05/1200Z...DISSIPATED

$$
FORECASTER CANGIALOSI/BROWN

[chadtm80]

[Chacor]

Wonder what GFS is seeing.

[HurricaneRobert]

Maybe regeneration over Lake Superior...

[cycloneye]

066
WTPZ44 KNHC 012042
TCDEP4
TROPICAL STORM JULIETTE DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142007
200 PM PDT MON OCT 01 2007

THE SATELLITE APPEARANCE OF JULIETTE HAS CONTINUED TO DEGRADE
DURING THE LAST SEVERAL HOURS. THE LOW-LEVEL CENTER IS NOW
COMPLETELY EXPOSED TO THE SOUTH OF A SHRINKING AND WEAKENING AREA OF
DEEP CONVECTION. SATELLITE INTENSITY ESTIMATES HAVE DECREASED
AND SUPPORT AN INITIAL INTENSITY OF 35 KT. GIVEN THE UNFAVORABLE
ENVIRONMENT AHEAD...ADDITIONAL WEAKENING AND DEGENERATION TO A
REMNANT LOW ARE EXPECTED WITHIN 36 HOURS. IF JULIETTE DOES NOT
GENERATE ADDITIONAL CONVECTION DURING THE NEXT 12-18 HOURS IT COULD
BECOME A REMNANT LOW MUCH SOONER.

THE INITIAL MOTION IS 335/8. JULIETTE HAS NOT DECELERATED IN ITS
FORWARD MOTION YET...HOWEVER THIS IS EXPECTED TO OCCUR SOON AS THE
CYCLONE BECOMES A SHALLOW SYSTEM. THE NEW TRACK FORECAST IS
SLIGHTLY FASTER THAN THE PREVIOUS ADVISORY DUE TO THIS CONTINUED
PACE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/2100Z 22.7N 115.5W 35 KT
12HR VT 02/0600Z 23.7N 115.8W 30 KT
24HR VT 02/1800Z 24.4N 116.0W 25 KT
36HR VT 03/0600Z 24.7N 116.1W 25 KT...REMNANT LOW
48HR VT 03/1800Z 25.1N 116.1W 20 KT...REMNANT LOW
72HR VT 04/1800Z...DISSIPATED

$$
FORECASTER BROWN/CANGIALOSI

[cycloneye]

883
WTPZ44 KNHC 020236
TCDEP4
TROPICAL DEPRESSION JULIETTE DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP142007
800 PM PDT MON OCT 01 2007

THE DEEP CONVECTION STARTED SEPARATING FROM THE LOW-LEVEL CENTER AT
ABOUT 18Z. NO NEW CONVECTION HAS FIRED UP SINCE THEN...AND THE
REMAINING COLD CLOUD TOPS ARE JUST CIRRUS DEBRIS RACING NORTHWARD.
THE EXPOSED SWIRL DOES NOT PRESENTLY QUALIFY AS A TROPICAL
CYCLONE... AND REDEVELOPMENT OF A MEANINGFUL AMOUNT OF DEEP
CONVECTION APPEARS UNLIKELY...DUE TO CONTINUING STRONG SOUTHERLY
SHEAR...AND SINCE THE UNDERLYING SSTS ARE QUICKLY COOLING AS THE
SYSTEM PROCEEDS NORTH-NORTHWESTWARD OR 340/8. IN MARGINAL
CIRCUMSTANCES WE MIGHT CONTINUE ADVISORIES AS A PRECAUTION...BUT IN
THIS CASE THE CONDITIONS ARE SUCH THAT I AM COMFORTABLE MAKING THIS
THE LAST ADVISORY ON JULIETTE. THE REMNANT LOW IS FORECAST TO
DECELERATE AS IT CONTINUES NORTH-NORTHWESTWARD...UNTIL IT LIKELY
DISSIPATES WITHIN THE NEXT COUPLE OF DAYS.

FOR ADDITIONAL INFORMATION ON THE REMNANT LOW PLEASE SEE HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER AWIPS
HEADER NFDHSFEPI AND WMO HEADER FZPN02 KWBC.


FORECAST POSITIONS AND MAX WINDS

INITIAL 02/0300Z 23.4N 115.8W 25 KT...DISSIPATING
12HR VT 02/1200Z 23.9N 116.0W 20 KT...REMNANT LOW
24HR VT 03/0000Z 24.3N 116.1W 20 KT...REMNANT LOW
36HR VT 03/1200Z 24.6N 116.2W 20 KT...REMNANT LOW
48HR VT 04/0000Z...DISSIPATED

$$
FORECASTER KNABB


Adios Juliette.

[CrazyC83]

No surprise, it looked like a dead storm for a while. Better luck next time in 2013 Juliette!

Don't let the crash on you!