ATL: OPHELIA - Remnants - Discussion

[CrazyC83]

My guess is that Ophelia peaked at 0000Z last night at 110 kt (pressure 949mb), since the cloud tops warmed a bit when the buoy passed over. It seems to be unchanged this morning though.

[brunota2003]

The lowest pressure measured at the Buoy was not 951.9, but 951.5 between 0750 and 0850 UTC.

Code: Select all

#YY  MM DD hh mm   PRES PTIME  WSPD  WDIR WTIME
#yr  mo dy hr mn    hPa  hhmm   m/s  degT  hhmm
2011 10 01 14 50 1005.7  1352    16   230  1415
2011 10 01 13 50 1003.4  1252    19   230  1256
2011 10 01 12 50 1000.7  1152    20   220  1249
2011 10 01 11 50  995.8  1051    23   230  1108
2011 10 01 10 50  987.1  0951    26   230  1001
2011 10 01 09 50  964.1  0851    34   230  0854
2011 10 01 08 50  951.5  0814    35   230  0846
2011 10 01 07 50  951.9  0746    43    90  0739


Also, I wish we had video cameras/webcams on the Buoys...that would be some wicked sound for sure!

[Ptarmigan]

Ophelia is quite an impressive storm.

[cycloneye]

HURRICANE OPHELIA INTERMEDIATE ADVISORY NUMBER 36A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL162011
200 PM AST SAT OCT 01 2011

...EYE OF HURRICANE OPHELIA OBSERVED ON BERMUDA RADAR...


SUMMARY OF 200 PM AST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...30.4N 62.9W
ABOUT 170 MI...275 KM SE OF BERMUDA
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...952 MB...28.11 INCHES


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

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* BERMUDA

FOR STORM INFORMATION SPECIFIC TO BERMUDA...PLEASE MONITOR PRODUCTS
ISSUED BY THE BERMUDA WEATHER SERVICE.

TROPICAL STORM WATCHES OR WARNINGS COULD BE REQUIRED FOR A PORTION
OF THE AVALON PENINSULA IN NEWFOUNDLAND LATER TODAY.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 200 PM AST...1800 UTC...THE EYE OF HURRICANE OPHELIA WAS
LOCATED NEAR LATITUDE 30.4 NORTH...LONGITUDE 62.9 WEST. OPHELIA IS
MOVING TOWARD THE NORTH NEAR 21 MPH...33 KM/H. ON THIS TRACK THE
CORE OF THE HURRICANE WILL PASS EAST OF BERMUDA LATER TODAY. A
TURN TO THE NORTH-NORTHEAST SHOULD BEGIN ON SUNDAY WITH AN INCREASE
IN FORWARD SPEED. OPHELIA IS FORECAST TO BE NEAR AND TO THE SOUTH
OF THE AVALON PENINSULA IN NEWFOUNDLAND ON MONDAY.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 120 MPH...195 KM/H...WITH HIGHER
GUSTS. OPHELIA IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME FLUCTUATIONS IN INTENSITY ARE LIKELY
TODAY...BUT A GRADUAL WEAKENING SHOULD BEGIN ON SUNDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 40 MILES...65 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205
MILES...335 KM MAINLY TO THE NORTH AND EAST OF THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 952 MB...28.11 INCHES. A
DRIFTING BUOY NEAR THE EYE OF OPHELIA REPORTED A MINIMUM PRESSURE
OF 959.7 MB...28.34 INCHES...A FEW HOURS AGO.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL-STORM-FORCE WINDS ARE POSSIBLE ON BERMUDA BY THIS
AFTERNOON.

SURF...LARGE SWELLS CREATED BY OPHELIA WILL CAUSE HAZARDOUS SURF
CONDITIONS ALONG THE SOUTH-FACING BEACHES OF BERMUDA.

RAINFALL...RAINFALL ACCUMULATIONS OF UP TO 1 INCH CAN BE EXPECTED
ON BERMUDA IN ASSOCIATION WITH OPHELIA.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...500 PM AST.

$$
FORECASTER AVILA

[jinftl]

The eye of Ophelia is making its debut on the Bermuda radar (far southeast corner of 240km circle)...far enough southeast of the island to pass to the east without much fanfare...if this system was 125 miles further west, we would be talking a direct hit on the island from a Cat 3 this afternoon like the buoy took last night.

[dwsqos2]

I made a post earlier in the season complaining about the scarcity of storms maintaining intensities greater than 90 knots north of 30N.

I'm retracting that statement.

[cycloneye]

HURRICANE OPHELIA DISCUSSION NUMBER 37
NWS NATIONAL HURRICANE CENTER MIAMI FL AL162011
500 PM AST SAT OCT 01 2011

OPHELIA HAS MAINTAINED ITS IMPRESSIVE CLOUD PATTERN...WITH A
DISTINCT EYE SURROUNDED BY A SYMMETRIC CENTRAL DENSE OVERCAST.
BECAUSE OBJECTIVE AND SUBJECTIVE T-NUMBERS HAVE NOT CHANGED...THE
INITIAL INTENSITY IS KEPT AT 105 KNOTS. SMALL FLUCTUATIONS IN
INTENSITY ARE EXPECTED IN THE NEXT 12 HOURS...BUT A GRADUAL
WEAKENING SHOULD BEGIN ON SUNDAY AS OPHELIA REACHES COOLER WATERS.
THERE IS A STRONG LIKELIHOOD THAT OPHELIA WILL BEGIN TO BECOME
POST-TROPICAL ON MONDAY AS IT PASSES NEAR OR OVER THE AVALON
PENINSULA IN NEWFOUNDLAND.

OPHELIA HAS BEGUN TO RECURVE AND IS NOW MOVING TOWARD THE NORTH OR
010 DEGREES AT 23 KNOTS. THE HURRICANE CONTINUES TO BE EMBEDDED IN
THE FAST SOUTHERLY FLOW BETWEEN THE SUBTROPICAL HIGH AND THE LARGE
TROUGH OVER THE EASTERN UNITED STATES. AS THE TROUGH MOVES
EASTWARD...OPHELIA SHOULD TURN MORE TOWARD THE NORTH-NORTHEAST WITH
AN INCREASE IN FORWARD SPEED. THE TRACK GUIDANCE CONTINUES TO BE
TIGHTLY PACKED...BUT THE ENTIRE ENVELOPE HAS SHIFTED A LITTLE BIT
NORTHWARD FOR THIS CYCLE. THE OFFICIAL FORECAST IS IN THE MIDDLE OF
THE GUIDANCE ENVELOPE AND TAKES THE CORE OF THE HURRICANE EAST OF
BERMUDA IN THE NEXT FEW HOURS AND BRINGS THE CENTER OF THE CYCLONE
NEAR THE AVALON PENINSULA ON MONDAY.


FORECAST POSITIONS AND MAX WINDS

INIT 01/2100Z 31.6N 62.6W 105 KT 120 MPH
12H 02/0600Z 35.0N 62.0W 100 KT 115 MPH
24H 02/1800Z 40.0N 60.4W 90 KT 105 MPH
36H 03/0600Z 45.0N 56.0W 65 KT 75 MPH
48H 03/1800Z 48.0N 48.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
72H 04/1800Z 50.0N 31.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 05/1800Z...DISSIPATED

$$
FORECASTER AVILA

[CrazyC83]

The lowest pressure measured at the Buoy was not 951.9, but 951.5 between 0750 and 0850 UTC.

Code: Select all

#YY  MM DD hh mm   PRES PTIME  WSPD  WDIR WTIME
#yr  mo dy hr mn    hPa  hhmm   m/s  degT  hhmm
2011 10 01 14 50 1005.7  1352    16   230  1415
2011 10 01 13 50 1003.4  1252    19   230  1256
2011 10 01 12 50 1000.7  1152    20   220  1249
2011 10 01 11 50  995.8  1051    23   230  1108
2011 10 01 10 50  987.1  0951    26   230  1001
2011 10 01 09 50  964.1  0851    34   230  0854
2011 10 01 08 50  951.5  0814    35   230  0846
2011 10 01 07 50  951.9  0746    43    90  0739


Also, I wish we had video cameras/webcams on the Buoys...that would be some wicked sound for sure!

With two measurements there, I would guess the pressure was 946mb at the time, and probably is about 943mb now I think. I would put the current intensity at 110 kt personally.

[CrazyC83]

EC only went with a Tropical Storm Watch for Newfoundland even though it is likely to be a hurricane still at that point? I wonder if this could pull a Juan and hold its intensity into the high latitudes?

[CrazyC83]

http://tropic.ssec.wisc.edu/real-time/w ... oom=&time=

Shear stays pretty low all the way to Newfoundland. Maybe Ophelia can remain strong all the way to 40N?

[CrazyC83]

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

----- Current Analysis -----
Date : 01 OCT 2011 Time : 221500 UTC
Lat : 31:55:44 N Lon : 62:20:36 W


CI# /Pressure/ Vmax
6.1 / 940.5mb/117.4kt


Final T# Adj T# Raw T#
6.1 6.2 6.2

Estimated radius of max. wind based on IR : 25 km

Center Temp : +14.2C Cloud Region Temp : -66.8C

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 : 120km
- Environmental MSLP : 1012mb

Satellite Viewing Angle : 39.6 degrees

[Hurricanehink]

If Ophelia becomes a Category 4 tonight, it would be the northernmost hurricane to attain that intensity since Diana in 1984, which did so at 33.9º N, off the coast of North Carolina.

[CrazyC83]

If Ophelia becomes a Category 4 tonight, it would be the northernmost hurricane to attain that intensity since Diana in 1984, which did so at 33.9º N, off the coast of North Carolina.

Hugo was lower when he became a Cat 4, correct? (although he was strengthening right up to SC landfall). Diana was such a small storm that she managed to use the Gulf Stream to perfection and was able to.

[cycloneye]

BULLETIN
HURRICANE OPHELIA INTERMEDIATE ADVISORY NUMBER 37A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL162011
800 PM AST SAT OCT 01 2011

...OPHELIA INTENSIFIES INTO A CATEGORY FOUR HURRICANE AS IT PASSES
EAST OF BERMUDA...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...32.5N 62.4W
ABOUT 140 MI...220 KM E OF BERMUDA
MAXIMUM SUSTAINED WINDS...135 MPH...215 KM/H
PRESENT MOVEMENT...N OR 10 DEGREES AT 26 MPH...43 KM/H
MINIMUM CENTRAL PRESSURE...944 MB...27.88 INCHES


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

NONE

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* THE AVALON PENINSULA OF NEWFOUNDLAND

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


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 PM AST...0000 UTC...THE EYE OF HURRICANE OPHELIA WAS LOCATED
BY BERMUDA RADAR NEAR LATITUDE 32.5 NORTH...LONGITUDE 62.4 WEST.
OPHELIA IS MOVING TOWARD THE NORTH NEAR 26 MPH...43 KM/H. A TURN
TOWARD THE NORTH-NORTHEAST SHOULD BEGIN ON SUNDAY WITH AN INCREASE
IN FORWARD SPEED. OPHELIA IS FORECAST TO BE NEAR THE AVALON
PENINSULA OF NEWFOUNDLAND ON MONDAY.

SATELLITE IMAGERY INDICATES THAT MAXIMUM SUSTAINED WINDS HAVE
INCREASED TO NEAR 135 MPH...215 KM/H...WITH HIGHER GUSTS. OPHELIA
IS A CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON HURRICANE WIND
SCALE. GRADUAL WEAKENING SHOULD BEGIN ON SUNDAY...WITH RAPID
WEAKENING LIKELY BY LATE SUNDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 185
MILES...295 KM MAINLY TO THE NORTH AND EAST OF THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 944 MB...27.88 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL-STORM-FORCE WINDS ARE POSSIBLE ON THE AVALON
PENINSULA EARLY MONDAY.

SURF...LARGE SWELLS CREATED BY OPHELIA WILL CAUSE HAZARDOUS SURF
CONDITIONS ON BERMUDA.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 PM AST.

$$
FORECASTER BLAKE/BRENNAN

[cycloneye]

Indeed Hurricanehink!!

...OPHELIA INTENSIFIES INTO A CATEGORY FOUR HURRICANE AS IT PASSES
EAST OF BERMUDA...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...32.5N 62.4W
ABOUT 140 MI...220 KM E OF BERMUDA
MAXIMUM SUSTAINED WINDS...135 MPH...215 KM/H
PRESENT MOVEMENT...N OR 10 DEGREES AT 26 MPH...43 KM/H
MINIMUM CENTRAL PRESSURE...944 MB...27.88 INCHES

[Hurricanehink]

If Ophelia becomes a Category 4 tonight, it would be the northernmost hurricane to attain that intensity since Diana in 1984, which did so at 33.9º N, off the coast of North Carolina.

Hugo was lower when he became a Cat 4, correct? (although he was strengthening right up to SC landfall). Diana was such a small storm that she managed to use the Gulf Stream to perfection and was able to.

Hugo reached C4 status twice. Once was near the Caribbean, and the other was at 30.2. I didn't count that since it reached C4 previously.

[jinftl]

Not sure if this is a consideration, but the Tropical Storm Watch was issued by Environment Canada, not the NHC. The 5pm forecast track shows the system as a hurricane when southwest of Newfoundland (H icon in the circle, forecast for 2am Monday), and then transitioning to extra-trop in the 12 hours that follow. Also, alot will depend on the track...if Newfoundland can stay west of the center, the forecast wind field is much smaller than if any land areas end up east of the center.

EC only went with a Tropical Storm Watch for Newfoundland even though it is likely to be a hurricane still at that point? I wonder if this could pull a Juan and hold its intensity into the high latitudes?

[Gustywind]

Indeed Hurricanehink!!

...OPHELIA INTENSIFIES INTO A CATEGORY FOUR HURRICANE AS IT PASSES
EAST OF BERMUDA...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...32.5N 62.4W
ABOUT 140 MI...220 KM E OF BERMUDA
MAXIMUM SUSTAINED WINDS...135 MPH...215 KM/H
PRESENT MOVEMENT...N OR 10 DEGREES AT 26 MPH...43 KM/H
MINIMUM CENTRAL PRESSURE...944 MB...27.88 INCHES

Always impressive to see a such powerfull cat 4 cane

[CrazyC83]

Rare to see a storm become so strong north of 30N.

[jinftl]

Given that the forecast was for a gradual weakening, this raises the possibilty that if the track is forecast to go over/very close to Newfoundland, we will be seeing Hurricane Watches before long. Even if the storm begins to weaken as forecast, the extra 15 mph intensity is enough to push the 60 mph forecast at it's approach to Newfoundland to 75 mph, all other factors equal (assuming the rate of weakening is the same).

Rare to see a storm become so strong north of 30N.