ATL: GORDON - Post-Tropical

[wxman57]

Looks impressive. Microwave and satellite imagery indicate an eye is forming.

[ROCK]

I take that back....a strong run at a cat 1 it seems. Just goes to show it aint all about water temps. Upper level conditions are even more so important.

[hurricanes1234]

Gordon seems to be rapidly intensifying. It went from 35 mph to 65 mph in only 18 hours and the pressure dropped considerably - I am sure the NHC will revise the intensity forecasts, showing Gordon peaking as at least an 80-85 mph storm. Woo hoo! But the Azores better be prepared.

______________
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[KWT]

As i said yesterday, never under-estimate a system moving NE above 25-30N, more often then not the NHC under-estimate such storms and the rate of strengthening that can happen up there. 75-85kts IMO would be a fairly reasonable end point for this system IMO.

[HurricaneAndrew92]

Probably a 55-60kt storm(65-70mph) at 5.
Image:

[cycloneye]

TROPICAL STORM GORDON DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082012
500 PM AST THU AUG 16 2012

GORDON HAS BEEN STRENGTHENING OVER THE PAST 12 HOURS. VISIBLE
SATELLITE IMAGERY CONTINUES TO SHOW TIGHTLY COILED CONVECTIVE CLOUD
BANDS SPIRALING INTO A SMALL CENTRAL DENSE OVERCAST FEATURE.
SATELLITE INTENSITY ESTIMATES ARE T3.5/55 KT FROM TAFB...T3.0/45 KT
FROM SAB...AND T2.7/39 KT ADT FROM UW-CIMSS. AN 1143 UTC SSMIS
IMAGE INDICATED A CLOSED MID-LEVEL EYE FEATURE AND A 1311 UTC ASCAT
OVERPASS REVEALED 39-KT SURFACE WINDS...WHICH WHEN ADJUSTED FOR THE
KNOWN LOW BIAS OF THE SCATTEROMETER DATA YIELDS ABOUT 44 KT. GIVEN
THE MUCH IMPROVED BANDING STRUCTURE SINCE THOSE MICROWAVE DATA WERE
ACQUIRED...THE INITIAL INTENSITY HAS BEEN INCREASED TO 55 KT.

GORDON IS NOW MOVING TOWARD THE EAST-NORTHEAST...OR 055/15 KT...AND
IS ON THE PREVIOUS FORECAST TRACK. THE CYCLONE IS MOVING ALONG THE
NORTHERN PERIPHERY OF THE SUBTROPICAL RIDGE AND WILL BE MOVING INTO
THE MID-LATITUDE WESTERLIES DURING THE NEXT 12-18 HOURS. GORDON
SHOULD GRADUALLY TURN EASTWARD AND CONTINUE THAT MOTION THROUGH AT
LEAST THE 48-HOUR FORECAST PERIOD. BY 72 HOURS...THE CYCLONE IS
FORECAST TO BEGIN LIFTING OUT TOWARD THE NORTHEAST AHEAD OF A
SHORTWAVE TROUGH...AND BE NEAR THE AZORES ISLANDS BETWEEN DAYS 3
AND 4. THE NHC TRACK GUIDANCE REMAINS TIGHTLY PACKED AROUND THE
PREVIOUS FORECAST TRACK...SO NO SIGNIFICANT CHANGES WERE MADE TO
THIS FORECAST PACKAGE.

UPPER-LEVEL OUTFLOW REMAINS WELL ESTABLISHED IN ALL QUADRANTS...AND
DRY MID-LEVEL AIR HAS MANAGED THUS FAR TO REMAIN AWAY FROM THE
INNER CORE REGION. WEAK VERTICAL SHEAR COUPLED WITH SSTS GREATER
THAN 27C SHOULD ALLOW FOR SOME ADDITIONAL INTENSIFICATION TO OCCUR
DURING THE NEXT 24-36 HOURS. BY 48 HOURS...HOWEVER...ENTRAINMENT OF
DRY MID-LEVEL AIR FROM THE WEST ALONG WITH INCREASING VERTICAL WIND
SHEAR IN EXCESS OF 30 KT SHOULD INDUCE STEADY WEAKENING. AS GORDON
NEARS THE AZORES ISLANDS IN 3 TO 4 DAYS...THE CYCLONE IS FORECAST
BY MOST OF THE GLOBAL MODELS TO MERGE WITH A FRONTAL SYSTEM AND
BECOME A STRONG EXTRATROPICAL CYCLONE. THE INTENSITY FORECAST IS
ONLY SLIGHTLY HIGHER THAN THE PREVIOUS ADVISORY...AND REMAINS CLOSE
TO IV15 INTENSITY CONSENSUS MODEL.

FORECAST POSITIONS AND MAX WINDS

INIT 16/2100Z 34.2N 52.1W 55 KT 65 MPH
12H 17/0600Z 34.7N 49.9W 60 KT 70 MPH
24H 17/1800Z 34.9N 46.2W 65 KT 75 MPH
36H 18/0600Z 34.7N 42.5W 70 KT 80 MPH
48H 18/1800Z 34.7N 38.6W 60 KT 70 MPH
72H 19/1800Z 36.1N 30.8W 55 KT 65 MPH
96H 20/1800Z 38.8N 23.2W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 21/1800Z 41.2N 15.8W 40 KT 45 MPH...POST-TROP/EXTRATROP

$$
FORECASTER STEWART

[Extratropical94]

Forecast/Advisory: PRESENT MOVEMENT TOWARD THE EAST-NORTHEAST OR 70 DEGREES AT 15 KT
Discussion: GORDON IS NOW MOVING TOWARD THE EAST-NORTHEAST...OR 055/15 KT

Looks like they got the intensity and the heading mixed up.

[Cyclenall]

I don't know if this was pointed out yet, but this Gordon is similar to the last Gordon in 2006 with the part of the basin and track towards the Azores moving east. Once/if it becomes a CAT1 hurricane and looks annular, it will be even more like the last Gordon.

[CrazyC83]

The size will grow as it moves towards the Azores most likely as well?

[hurricanes1234]

It looks a little bit like a hurricane - the well-established outflow and the impressive rainbands. I'd say about 70-80 mph by the 00z update. No doubt this is gaining some strength - note the fairly quick pressure drop in the middle of the Bermuda-Azores high. Just 24 hours ago, this was a depression with a minimum pressure of 1013 mbar, now it's at 999 mbar, and may be even lower by the 00z update.

______________
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[ozonepete]

It looks a little bit like a hurricane - the well-established outflow and the impressive rainbands. I'd say about 70-80 mph by the 00z update. No doubt this is gaining some strength - note the fairly quick pressure drop in the middle of the Bermuda-Azores high. Just 24 hours ago, this was a depression with a minimum pressure of 1013 mbar, now it's at 999 mbar, and may be even lower by the 00z update.
______________
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

There is no 00Z update. Next is at 11PM.

[cycloneye]

It looks a little bit like a hurricane - the well-established outflow and the impressive rainbands. I'd say about 70-80 mph by the 00z update. No doubt this is gaining some strength - note the fairly quick pressure drop in the middle of the Bermuda-Azores high. Just 24 hours ago, this was a depression with a minimum pressure of 1013 mbar, now it's at 999 mbar, and may be even lower by the 00z update.
______________
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

There is no 00Z update. Next is at 11PM.

He may be talking about the 00z Best Track.

[hurricanes1234]

Yeah, I meant the 00z best track...sorry.

[CrazyC83]

20120816 2345 34.5 51.2 T3.0/3.0 08L GORDON

It was one of the lower ones at 18Z as well.

[hurricanes1234]

20120816 2345 34.5 51.2 T3.0/3.0 08L GORDON

It was one of the lower ones at 18Z as well.

Please pardon me, but what does this mean?

[CrazyC83]

20120816 2345 34.5 51.2 T3.0/3.0 08L GORDON

It was one of the lower ones at 18Z as well.

Please pardon me, but what does this mean?

The SSD (one of several satellite estimate agencies) had T3.0, or 45 kt, as its intensity. Others had it higher. Most likely it will be either 55 or 60 kt at next advisory.

[cycloneye]

Up to 60kts on 00z Best Track

AL, 08, 2012081700, , BEST, 0, 345N, 512W, 60, 995, TS

ftp://ftp.nhc.noaa.gov/atcf/tcweb/inves ... 012.invest

[hurricanes1234]

Up to 60kts on 00z Best Track

AL, 08, 2012081700, , BEST, 0, 345N, 512W, 60, 995, TS

ftp://ftp.nhc.noaa.gov/atcf/tcweb/inves ... 012.invest

Thanks.
Gordon is now on the brink of hurricane status. (60 knots - 70 mph)

[cycloneye]

WTNT43 KNHC 170231
TCDAT3

TROPICAL STORM GORDON DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082012
1100 PM AST THU AUG 16 2012

ALTHOUGH THE CONVECTION IS NOT VERY DEEP...SATELLITE IMAGES SHOW
THAT THE CLOUD PATTERN HAS BECOME SYMMETRIC WITH THE CENTER OF THE
CYCLONE EMBEDDED WITHIN A CIRCULAR AREA OF THE STRONGEST CONVECTION.
A WELL-DEFINED CYCLONICALLY-CURVED BAND IS WRAPPING AROUND THE
NORTH AND EAST SIDES OF THE CIRCULATION. T-NUMBERS FROM BOTH
TAFB AND SAB ARE 4.0 AND 3.0 RESPECTIVELY. AN AVERAGE OF THESE TWO
ESTIMATES SUGGESTS AN INITIAL INTENSITY OF 60 KNOTS. GORDON ONLY
HAS A DAY OR SO TO BECOME A HURRICANE BEFORE IT MOVES OVER COOLER
WATERS AND ENCOUNTERS STRONG SHEAR. A GRADUAL WEAKENING SHOULD THEN
BEGIN...BUT GORDON IS FORECAST TO REMAIN A TROPICAL STORM BY THE
TIME IT MOVES THROUGH THE AZORES IN 3 DAYS. ONCE GORDON MOVE EAST OF
THE AZORES...IT SHOULD ACQUIRE EXTRATROPICAL CHARACTERISTICS.

GORDON IS MOVING TOWARD THE EAST OR 085 DEGREES AT 15 KNOTS...WELL
EMBEDDED WITHIN THE MID-LATITUDE WESTERLIES. SINCE THE STEERING
CURRENTS ARE FORECAST BY THE GLOBAL MODELS TO REMAIN WELL
ESTABLISHED...GORDON SHOULD CONTINUE TO MOVE EASTWARD FOR THE NEXT
THREE DAYS WITH NO SIGNIFICANT CHANGE IN FORWARD SPEED. TRACK
MODELS ARE IN REMARKABLY GOOD AGREEMENT IN BRINGING THE CYCLONE
EASTWARD THROUGH THE AZORES. MODELS ALSO SHOW A GRADUAL TURN TOWARD
THE NORTHEAST BY 72 HOURS AS A SHORTWAVE TROUGH AMPLIFIES TO THE
WEST OF THE CYCLONE. THE OFFICIAL FORECAST IS IN THE MIDDLE OF THE
GUIDANCE ENVELOPE AND BRINGS GORDON THROUGH THE AZORES IN ABOUT 3
DAYS.


FORECAST POSITIONS AND MAX WINDS

INIT 17/0300Z 34.6N 50.3W 60 KT 70 MPH
12H 17/1200Z 34.9N 47.7W 65 KT 75 MPH
24H 18/0000Z 34.8N 43.5W 70 KT 80 MPH
36H 18/1200Z 34.5N 39.5W 65 KT 75 MPH
48H 19/0000Z 34.5N 35.9W 60 KT 70 MPH
72H 20/0000Z 36.5N 28.5W 50 KT 60 MPH
96H 21/0000Z 39.0N 21.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 22/0000Z 41.0N 15.0W 40 KT 45 MPH...POST-TROP/EXTRATROP

$$
FORECASTER AVILA

[hurricanes1234]

Gordon's appearance now seems less defined. Just my opinion as of 11:00 PM AST.