ATL: OPHELIA - Remnants - Discussion

[RL3AO]

When western Atlantic systems head north they tend to react with intensification. Why is that? Better outflow?

I think its just the areas north of the deep tropics just have better upper level conditions.

As the poster above said, the biggest part of it is once their moving north they aren't dealing with those screaming easterlies that have been that have been slowing things down all year.

[Dave C]

Also, when they turn north they are rounding the sw quadrant of the subtrop. ridge which is best spot for ramping up

[Fyzn94]

Eerie resemblance anyone?

Ophelia:





Hortense (1996):

[cycloneye]

HURRICANE OPHELIA DISCUSSION NUMBER 33
NWS NATIONAL HURRICANE CENTER MIAMI FL AL162011
500 PM AST FRI SEP 30 2011

OPHELIA HAS MAINTAINED A DISTINCT EYE ON SATELLITE IMAGES DURING THE
DAY. THE INTENSITY OF THE CONVECTION SURROUNDING THE EYE HAS BEEN
FLUCTUATING AND THERE IS A SALIENT THUNDERSTORM BAND WRAPPING AROUND
THE NORTH AND EAST OF THE CENTRAL DENSE OVERCAST. SUBJECTIVE
T-NUMBERS HAVE NOT CHANGED WHILE THE ADT OBJECTIVE ESTIMATES FROM
UW-CIMSS HAVE BEEN NEAR 5.9 DURING THE PAST FEW HOURS. THE AVERAGE
OF THESE TWO ESTIMATES SUPPORT KEEPING THE INITIAL INTENSITY AT 100
KNOTS.

SOME INTENSITY FLUCTUATIONS ARE ANTICIPATED DURING THE NEXT DAY OR
SO WHILE OPHELIA IS OVER WARM WATERS AND EMBEDDED WITHIN A LOW
SHEAR ENVIRONMENT AS DIAGNOSED BY THE SHIPS MODELS. THEREAFTER...
THE HURRICANE SHOULD BE MOVING INTO INCREASING SHEAR AND ENCOUNTER
COLD WATERS...RESULTING IN WEAKENING. OPHELIA SHOULD BECOME A
POST-TROPICAL CYCLONE AS IT MOVES TO THE SOUTHEAST OF NEWFOUNDLAND
IN 72 HOURS AND THEN BECOME ABSORBED BY A LARGER FRONTAL SYSTEM.

OPHELIA IS MOVING TOWARD THE NORTH OR 350 DEGREES AT 12 KNOTS
EMBEDDED WITHIN THE FLOW BETWEEN THE ATLANTIC SUBTROPICAL HIGH AND
A LARGE MID-LATITUDE TROUGH OVER THE EASTERN UNITED STATES. THIS
PATTERN SHOULD FORCE OPHELIA TO CONTINUE MOVING NORTHWARD DURING
THE NEXT 24 HOURS AND THEN RECURVE WITH AN INCREASE IN FORWARD
SPEED...AS THE CORE OF THE CYCLONE PASSES EAST OF BERMUDA.
THE CONFIDENCE IN THE NHC TRACK FORECAST REMAINS HIGH SINCE THE
TRACK GUIDANCE IS TIGHTLY CLUSTERED. AS INDICATED IN PREVIOUS
ADVISORIES...THE WESTERN EDGE OF THE TRACK ENVELOPE CONTINUES TO BE
EAST OF BERMUDA.


FORECAST POSITIONS AND MAX WINDS

INIT 30/2100Z 24.7N 63.0W 100 KT 115 MPH
12H 01/0600Z 26.5N 63.2W 100 KT 115 MPH
24H 01/1800Z 29.8N 62.8W 100 KT 115 MPH
36H 02/0600Z 34.0N 62.0W 90 KT 105 MPH
48H 02/1800Z 39.0N 60.0W 85 KT 100 MPH
72H 03/1800Z 48.0N 47.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 04/1800Z...ABSORBED BY A FRONTAL SYSTEM

$$
FORECASTER AVILA

[GCANE]

When western Atlantic systems head north they tend to react with intensification. Why is that? Better outflow?

I took an advanced mechanics course in physics.

I did an analysis of the coriolis effect and found out when a body is moving north there is an additional coriolis force applied to it.

If I remember correctly, this secondary effect diminishes rapidly when the body is moving in a direction other than north.

[brunota2003]

Following Ophelia's path, she'll be moving almost directly over Buoy 41049 overnight. Winds there are already sustained up to 27 knots, with a pressure of 1010 millibars (29.83 inches).

http://www.ndbc.noaa.gov/station_page.php?station=41049

Here's to hoping that buoy holds on for as long as possible, and gives us some observations at the surface!

[MGC]

Ophelia: come back storm of the year.

Opehelia still looks to be intensifying, the IR loop is showing a good bit of colder cloud tops which have increased in the last few frames.....MGC

[CrazyC83]

Following Ophelia's path, she'll be moving almost directly over Buoy 41049 overnight. Winds there are already sustained up to 27 knots, with a pressure of 1010 millibars (29.83 inches).

http://www.ndbc.noaa.gov/station_page.php?station=41049

Here's to hoping that buoy holds on for as long as possible, and gives us some observations at the surface!

My guess right now is 105 kt (pressure 948mb) for the intensity, but we will see what the buoy gives us!

[bg1]

Ophelia: come back storm of the year.

Definitely. Remember when we were losing patience and interest in this storm, and it looked like this?

http://myweb.cableone.net/nolasue/Ophelia1.gif

This was just four days ago. Events like these makes watching the tropics worthwhile.

Now if Philippe can just degenerate into a wave, become a Category 4 500 miles northeast of Bermuda, and zoom between Greenland and Iceland as a tropical entity, this will make my year of tropic watching.

[Fyzn94]

Ophelia: come back storm of the year.

The Jesus of this year's storms, if you will.

[Macrocane]

3 majors not so bad, many seasons in the warm AMO phase have had 3 majors.

[cycloneye]

BULLETIN
HURRICANE OPHELIA INTERMEDIATE ADVISORY NUMBER 33A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL162011
800 PM AST FRI SEP 30 2011

...OPHELIA BECOMES STRONGER AS IT MOVES FASTER TO THE NORTH...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...25.6N 63.0W
ABOUT 480 MI...770 KM SSE OF BERMUDA
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...N OR 355 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...956 MB...28.23 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.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 PM AST...0000 UTC...THE EYE OF HURRICANE OPHELIA WAS LOCATED
NEAR LATITUDE 25.6 NORTH...LONGITUDE 63.0 WEST. OPHELIA IS MOVING
TOWARD THE NORTH NEAR 16 MPH...26 KM/H. THIS GENERAL MOTION IS
EXPECTED TO CONTINUE DURING THE NEXT DAY OR SO...BRINGING THE CORE
OF OPHELIA EAST OF BERMUDA LATE SATURDAY. A TURN TO THE NORTH-
NORTHEAST SHOULD BEGIN BY SUNDAY WITH AN INCREASE IN FORWARD SPEED.

SATELLITE IMAGERY INDICATES THAT THE MAXIMUM SUSTAINED WINDS HAVE
INCREASED TO 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 DURING THE NEXT
12 TO 24 HOURS FOLLOWED BY A GRADUAL WEAKENING.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175
MILES...280 KM MAINLY TO THE NORTH AND EAST OF THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 956 MB...28.23 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM FORCE WINDS ARE POSSIBLE ON BERMUDA STARTING
SATURDAY 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...1100 PM AST.

$$
FORECASTER BLAKE/FRANKLIN

[cycloneye]

Up to 105kts.

...OPHELIA BECOMES STRONGER AS IT MOVES FASTER TO THE NORTH...


SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...25.6N 63.0W
ABOUT 480 MI...770 KM SSE OF BERMUDA
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...N OR 355 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...956 MB...28.23 INCHES

[CrazyC83]

Seems reasonable, we'll see what the buoy says!

[AJC3]

Seems reasonable, we'll see what the buoy says!

Should be a direct hit. The latest for those following...

[CrazyC83]

30/2345 UTC 25.5N 62.9W T5.5/5.5 OPHELIA -- Atlantic

[cycloneye]

105kts.

AL, 16, 2011100100, , BEST, 0, 256N, 630W, 105, 956, HU

ftp://ftp.tpc.ncep.noaa.gov/atcf/tcweb/ ... 011.invest

[lester]

Ophelia: come back storm of the year.

The Jesus of this year's storms, if you will.

que? o_O

[jinftl]

yep...we got a real deal hurricane here...

[fci]

yep...we got a real deal hurricane here...

http://img62.imageshack.us/img62/6015/ir4lv.jpg

Wow!
A thing of Tropical Beauty!!!
As long as she avoids Bermuda and Canada, what a beauty!