ATL: GORDON - Post-Tropical

[cycloneye]

HURRICANE GORDON DISCUSSION NUMBER 11
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082012
500 AM AST SAT AUG 18 2012

GORDON HAS BECOME BETTER ORGANIZED DURING THE PAST FEW HOURS.
CONVECTION HAS WRAPPED ALL THE WAY AROUND THE CENTER...AND
RECENT TRMM AND SSM/I OVERPASSES SHOWED AN EYE HAS DEVELOPED.
SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB WERE 55 KT AT 0600
UTC...AND AN AMSU ESTIMATE FROM CIMSS AT 0454 UTC WAS 64 KT. BASED
ON THESE DATA AND THE SUBSEQUENT INCREASE IN ORGANIZATION...GORDON
IS UPGRADED TO A HURRICANE.

THE INITIAL MOTION IS 090/16. A LARGE DEEP-LAYER LOW CENTERED WEST
OF THE BRITISH ISLES SHOULD STEER GORDON EASTWARD TO EAST-
NORTHEASTWARD FOR THE NEXT 48-72 HR. AFTER THAT...A SLOWER MOTION
TOWARD THE EAST IS EXPECTED AS THE LOW LIFTS OUT TO THE NORTHEAST
AND A LOW-LEVEL RIDGE BUILDS TO THE NORTH AND NORTHWEST OF GORDON.
THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK AND LIES
NEAR THE CENTER OF THE TRACK GUIDANCE ENVELOPE.

THE VERTICAL WIND SHEAR IS CURRENTLY LIGHT AND THE SEA SURFACE
TEMPERATURES ARE RELATIVELY WARM...FAVORABLE CONDITIONS FOR
STRENGTHENING OR AT LEAST MAINTAINING THE CURRENT INTENSITY FOR THE
NEXT 12-18 HR. THE NEW INTENSITY FORECAST THUS CALLS FOR GORDON TO
REMAIN A HURRICANE TODAY. AFTER THAT...INCREASING SHEAR...
DECREASING SSTS...AND THE ONSET OF EXTRATROPICAL TRANSITION SHOULD
CAUSE A STEADY WEAKENING. GORDON IS FORECAST TO BECOME
EXTRATROPICAL BY 72 HR AND DISSIPATE COMPLETELY BY 120 HR IN
AGREEMENT WITH THE GLOBAL MODEL GUIDANCE.


FORECAST POSITIONS AND MAX WINDS

INIT 18/0900Z 34.0N 40.7W 65 KT 75 MPH
12H 18/1800Z 34.0N 37.7W 65 KT 75 MPH
24H 19/0600Z 34.5N 33.7W 60 KT 70 MPH
36H 19/1800Z 35.3N 29.9W 55 KT 65 MPH
48H 20/0600Z 36.5N 26.5W 50 KT 60 MPH
72H 21/0600Z 38.5N 20.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
96H 22/0600Z 38.5N 16.5W 30 KT 35 MPH...POST-TROP/EXTRATROP
120H 23/0600Z...DISSIPATED

$$
FORECASTER BEVEN

[jinftl]

Looks like an eye trying to form very near the center of circulation on the 5am advisory (34N 40W)

[Recurve]

How disorienting is it to watch a sat loop with normal counter-clockwise rotation but the system's moving east. I'm getting dizzy.

I hope people over there are prepared for some rough surf at least.

I did not expect Gordon to look so impressive, although the presentation is changing...

[jinftl]

Up t0 80 mph and pressure down another 3 mb since 5am!

HURRICANE GORDON INTERMEDIATE ADVISORY NUMBER 11A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082012
800 AM AST SAT AUG 18 2012

...GORDON A LITTLE STRONGER...


SUMMARY OF 800 AM AST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...33.9N 39.6W
ABOUT 760 MI...1220 KM WSW OF THE AZORES
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...E OR 90 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...985 MB...29.09 INCHES

[tolakram]

Latest Loop

[tolakram]

Live visible Loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... 5&map=none

Latest

[jinftl]

Gordon woke up, his eye is open!

[rainstorm]

looks like a cat2

[cycloneye]

BULLETIN
HURRICANE GORDON INTERMEDIATE ADVISORY NUMBER 11A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082012
800 AM AST SAT AUG 18 2012

...GORDON A LITTLE STRONGER...


SUMMARY OF 800 AM AST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...33.9N 39.6W
ABOUT 760 MI...1220 KM WSW OF THE AZORES
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...E OR 90 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...985 MB...29.09 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE CENTRAL AND EASTERN AZORES

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 AM AST...1200 UTC...THE EYE OF HURRICANE GORDON WAS LOCATED
NEAR LATITUDE 33.9 NORTH...LONGITUDE 39.6 WEST. GORDON IS MOVING
TOWARD THE EAST NEAR 18 MPH...30 KM/H...AND THIS MOTION IS EXPECTED
TO CONTINUE TODAY. A TURN TOWARD THE EAST-NORTHEAST IS EXPECTED ON
SUNDAY. ON THE FORECAST TRACK...THE CENTER OF GORDON SHOULD
APPROACH THE CENTRAL AND EASTERN AZORES ON SUNDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 80 MPH...130 KM/H...
WITH HIGHER GUSTS. GORDON IS A CATEGORY ONE HURRICANE ON THE
SAFFIR-SIMPSON HURRICANE WIND SCALE. LITTLE ADDITIONAL CHANGE IN
STRENGTH IS EXPECTED TODAY. WEAKENING IS EXPECTED TONIGHT AND
SUNDAY...AND GORDON IS EXPECTED TO WEAKEN TO A TROPICAL STORM AS IT
APPROACHES THE AZORES.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO
125 MILES...205 KM..MAINLY TO THE SOUTH OF THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 985 MB...29.09 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED IN THE CENTRAL AND
EASTERN AZORES BY LATE SUNDAY.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 AM AST.

$$
FORECASTER BRENNAN

[cycloneye]

BULLETIN
HURRICANE GORDON INTERMEDIATE ADVISORY NUMBER 11A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082012
800 AM AST SAT AUG 18 2012

...GORDON A LITTLE STRONGER...


SUMMARY OF 800 AM AST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...33.9N 39.6W
ABOUT 760 MI...1220 KM WSW OF THE AZORES
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...E OR 90 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...985 MB...29.09 INCHES

[SouthDadeFish]

Looking good. The eye is very apparent on IR imagery:

[Extratropical94]

He seems to have peaked again. Based on those IR images, I'd say he was strongest at around 1030-1100Z, probably a borderline category 1/2 hurricane.

[jinftl]

Gordon is over an area of water 1+ deg C above normal and will be moving into water up to and over 2 deg C above normal. May be a factor in the intensification we are seeing as he is currently in water around 27C (81F) and if he maintains the same latitude, the water ahead is 26C or so.

[Extratropical94]

12Z Best track:
AL, 08, 2012081812, , BEST, 0, 340N, 396W, 70, 983, HU

[CrazyC83]

20120818 1145 33.8 39.4 T4.0/4.0 08L GORDON

[CrazyC83]

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

----- Current Analysis -----
Date : 18 AUG 2012 Time : 121500 UTC
Lat : 33:50:02 N Lon : 39:08:19 W


CI# /Pressure/ Vmax
5.1 / 963.1mb/ 92.4kt


Final T# Adj T# Raw T#
5.1 5.1 5.1

Estimated radius of max. wind based on IR : 28 km

Center Temp : -6.0C Cloud Region Temp : -53.5C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

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

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 95km
- Environmental MSLP : 1015mb

Satellite Viewing Angle : 54.7 degrees

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

[cycloneye]

TNT43 KNHC 181436
TCDAT3

HURRICANE GORDON DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082012
1100 AM AST SAT AUG 18 2012

GORDON HAS CONTINUED TO STRENGTHEN THIS MORNING. THE EYE HAS BECOME
A LITTLE MORE APPARENT IN GEOSTATIONARY IMAGERY OVER THE PAST FEW
HOURS...AND IS QUITE DISTINCT IN RECENT MICROWAVE IMAGES. THE
INITIAL INTENSITY IS SET TO 70 KT BASED ON A BLEND OF THE LATEST
DVORAK ESTIMATES FROM TAFB AND SAB. THERE IS STILL TIME FOR GORDON
TO STRENGTHEN A BIT MORE BEFORE THE CYCLONE REACHES COOLER
WATERS IN ABOUT 24 HOURS...SO THE OFFICIAL FORECAT HAS BEEN
ADJUSTED UPWARD TO ACCOUNT FOR THAT POSSIBILITY AND THE OBSERVED
INTENSIFICATION. SOUTHWESTERLY SHEAR IS EXPECTED TO INCREASE
MARKEDLY BY 24 TO 36 HOURS AS A SHORTWAVE TROUGH APPROACHES THE
CYCLONE FROM THE NORTHWEST. THE INCREASED SHEAR COMBINED WITH
COOLER SSTS SHOULD RESULT IN STEADY WEAKENING. GLOBAL MODEL FIELDS
SHOW GORDON BECOMING EXTRATROPICAL BY 72 HOURS AND DISSIPATING BY
THE END OF THE PERIOD.

THE INITIAL MOTION ESTIMATE IS 090/16...AS GORDON IS BEING STEERED
EASTWARD BY A DEEP LAYER CYCLONE WEST OF THE BRITISH ISLES. A TURN
TOWARD THE EAST-NORTHEAST IS EXPECTED ON SUNDAY AS THE SHORTWAVE
TROUGH APPROACHES GORDON AND THE LARGER DEEP-LAYER LOW LIFTS
NORTHWARD. OVERALL THE TRACK MODEL GUIDANCE IS FASTER THIS CYCLE...
AND THE NHC FORECAST HAS BEEN ADJUSTED IN THAT DIRECTION. THE NEW
NHC TRACK IS CLOSE TO THE LATEST MULTI-MODEL CONSENSUS AND LIES
BETWEEN THE ECMWF AND GFS MODELS.

GIVEN THE NEW INTENSITY AND TRACK FORECAST...THE GOVERNMENT OF
PORTUGAL HAS ISSUED A HURRICANE WARNING FOR THE CENTRAL AND EASTERN
AZORES AT THIS TIME.

FORECAST POSITIONS AND MAX WINDS

INIT 18/1500Z 34.1N 38.6W 70 KT 80 MPH
12H 19/0000Z 34.3N 35.5W 75 KT 85 MPH
24H 19/1200Z 35.0N 31.4W 70 KT 80 MPH
36H 20/0000Z 36.1N 27.8W 65 KT 75 MPH
48H 20/1200Z 37.4N 24.6W 55 KT 65 MPH
72H 21/1200Z 38.5N 20.0W 35 KT 40 MPH...POST-TROP/EXTRATROP
96H 22/1200Z 38.5N 16.0W 30 KT 35 MPH...POST-TROP/EXTRATROP
120H 23/1200Z...DISSIPATED

$$
FORECASTER BRENNAN

[hurricanes1234]

Maybe a 90 mph Category 1 or 100 mph Category 2 at peak strength.

_______________
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[cycloneye]

GORDON MOVING QUICKLY EASTWARD...HURRICANE WARNING ISSUED FOR THE
CENTRAL AND EASTERN AZORES...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...34.1N 38.6W
ABOUT 700 MI...1130 KM WSW OF THE AZORES
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...E OR 90 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...983 MB...29.03 INCHES

[CrazyC83]

I'd say it is a bit more than 70 kt personally, especially given the ADT and open eye.