Extratropical Irene Advisories

[gatorcane]

ALONG THE SOUTHERN PERIPHERY OF THE LOWER/MID LEVEL SUBTROPICAL RIDGE. THE SLOW MOTION SHOWN AT THE END OF THE OFFICIAL FORECAST IS INDICATIVE OF THE GREAT UNCERTAINTY LATE IN THE PERIOD...WHEN THE SPREAD IN THE MODELS IS STILL QUITE SIGNIFICANT.

That's because it is trending more and more west with each model run....

[cycloneye]

WTNT24 KNHC 090233
TCMAT4
TROPICAL DEPRESSION IRENE FORECAST/ADVISORY NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092005
0300Z TUE AUG 09 2005

TROPICAL DEPRESSION CENTER LOCATED NEAR 22.6N 52.7W AT 09/0300Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 11 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1009 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 22.6N 52.7W AT 09/0300Z
AT 09/0000Z CENTER WAS LOCATED NEAR 22.5N 52.1W

FORECAST VALID 09/1200Z 23.0N 54.4W
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 10/0000Z 23.7N 56.7W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 60NE 40SE 20SW 60NW.

FORECAST VALID 10/1200Z 24.5N 59.0W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 60NE 40SE 20SW 60NW.

FORECAST VALID 11/0000Z 25.5N 61.2W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 60NE 40SE 20SW 60NW.

FORECAST VALID 12/0000Z 28.0N 64.5W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 60NE 40SE 20SW 60NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM
ON DAY 4 AND 325 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 13/0000Z 30.0N 65.0W
MAX WIND 45 KT...GUSTS 55 KT.

OUTLOOK VALID 14/0000Z 32.0N 65.0W
MAX WIND 45 KT...GUSTS 55 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 22.6N 52.7W

NEXT ADVISORY AT 09/0900Z

FORECASTER PASCH

[cycloneye]

382
WTNT44 KNHC 090235
TCDAT4
TROPICAL DEPRESSION IRENE DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT MON AUG 08 2005

IRENE CONTINUES TO LOOK INSIGNIFICANT ON SATELLITE IMAGES...AND
SHOWS NO INDICATIONS OF RESTRENGTHENING ANY TIME SOON. THE
LOW-CLOUD CENTER IS NEAR THE WESTERN EDGE OF A SMALL AREA OF DEEP
CONVECTION...AND THERE ARE NO OBVIOUS BANDING FEATURES. THE
DEPRESSION IS BEING SHEARED BY WESTERLY FLOW ASSOCIATED WITH THE
MID-ATLANTIC UPPER-LEVEL TROUGH. ALSO...DROPSONDE DATA FROM A
SAHARAN AIR LAYER RESEARCH MISSION WITH THE NOAA G-IV JET CONFIRM
THAT IRENE IS IN AN ENVIRONMENT OF VERY DRY MID- TO UPPER-
TROPOSPHERIC AIR. AS THE CYCLONE MOVES FARTHER TO THE WEST-
NORTHWEST OVER THE NEXT COUPLE OF DAYS...IT IS LIKELY TO ENTER A
WEAKER WIND SHEAR ENVIRONMENT SINCE THE UPPER FLOW IS EXPECTED TO
BECOME MORE SOUTHEASTERLY. SOME RESTRENGTHENING IS THEREFORE SHOWN
IN THE FORECAST.

INITIAL MOTION IS 285/11. IRENE IS EXPECTED TO EVENTUALLY TURN MORE
NORTHWARD LATER IN THE FORECAST PERIOD...IN RESPONSE TO A WEAKNESS
IN THE SUBTROPICAL RIDGE NEAR BERMUDA. HOWEVER THERE ARE
SIGNIFICANT DIFFERENCES OF OPINION AMONG THE GLOBAL MODELS AS TO
THE CONFIGURATION OF THE SUBTROPICAL RIDGE OVER THE WESTERN
ATLANTIC AT DAYS 4-5. BY THAT TIME IT DOES APPEAR THAT THE
STEERING CURRENTS WILL BECOME QUITE WEAK...SO THE FORWARD SPEED IS
FORECAST TO SLOW CONSIDERABLY LATE IN THE PERIOD. THE OFFICIAL
FORECAST FOR THIS ADVISORY IS SIMILAR TO THE PREVIOUS ONE THROUGH
DAY 3 AND SHIFTED A LITTLE TO THE EAST AFTERWARDS...BUT NOT AS FAR
EAST AS THE DYNAMICAL CONSENSUS.

FORECASTER PASCH


FORECAST POSITIONS AND MAX WINDS

INITIAL 09/0300Z 22.6N 52.7W 30 KT
12HR VT 09/1200Z 23.0N 54.4W 30 KT
24HR VT 10/0000Z 23.7N 56.7W 35 KT
36HR VT 10/1200Z 24.5N 59.0W 35 KT
48HR VT 11/0000Z 25.5N 61.2W 40 KT
72HR VT 12/0000Z 28.0N 64.5W 40 KT
96HR VT 13/0000Z 30.0N 65.0W 45 KT
120HR VT 14/0000Z 32.0N 65.0W 45 KT

[cycloneye]

[Brent]

Bermuda must be 2005's Florida...

[deltadog03]

ok, don't really see the reasoning by that...to shift east and a 285 heading...but, whatever..

[Ivanhater]

ok, don't really see the reasoning by that...to shift east and a 285 heading...but, whatever..

ya, .1n and 1.2w from last advisory, tell me that aint west!!

[storms in NC]

my head is spining cause they are going back and forth.

[Matt-hurricanewatcher]

000
WTNT34 KNHC 090834
TCPAT4
BULLETIN
TROPICAL DEPRESSION IRENE ADVISORY NUMBER 19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM AST TUE AUG 09 2005

...IRENE MOVING WESTWARD...

AT 5 AM AST...0900Z...THE CENTER OF TROPICAL DEPRESSION IRENE WAS
LOCATED NEAR LATITUDE 22.5 NORTH... LONGITUDE 53.6 WEST OR ABOUT
965 MILES...1550 KM... SOUTHEAST OF BERMUDA.

IRENE IS MOVING TOWARD THE WEST NEAR 12 MPH ...19 KM/HR. A RETURN
TO A WEST-NORTHWESTWARD TRACK IS EXPECTED DURING THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH... 55 KM/HR...WITH HIGHER
GUSTS. IRENE COULD REGAIN TROPICAL STORM STRENGTH DURING THE NEXT 24
HOURS.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1009 MB...29.80 INCHES.

REPEATING THE 5 AM AST POSITION...22.5 N... 53.6 W. MOVEMENT
TOWARD...WEST NEAR 12 MPH. MAXIMUM SUSTAINED
WINDS... 35 MPH. MINIMUM CENTRAL PRESSURE...1009 MB.

THE NEXT ADVISORY ON IRENE WILL BE ISSUED BY THE
NWS/HYDROMETEOROLOGICAL PREDICTION CENTER AT 11 AM AST.

FORECASTER FRANKLIN


$$

Why are they handing this off to them?

[Matt-hurricanewatcher]

000
WTNT44 KNHC 090833
TCDAT4
TROPICAL DEPRESSION IRENE DISCUSSION NUMBER 19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT TUE AUG 09 2005

THERE HAS BEEN SOME INCREASE IN THE DEEP CONVECTION NEAR THE CENTER
OF IRENE'S MOSTLY EXPOSED CIRCULATION. WHILE THERE MAY WELL BE 35
KT WINDS IN THE SYSTEM AT THIS MOMENT...I WOULD PREFER TO SEE THIS
CONVECTION PERSIST NEAR THE CENTER BEFORE RE-UPGRADING IRENE TO A
TROPICAL STORM. THE 6Z DVORAK INTENSITY ESTIMATES WERE 25-30
KT...AND THE INITIAL INTENSITY WILL BE HELD AT 30 KT FOR THIS
ADVISORY.

IRENE IS PRESENTLY MOVING PAST A BREAK IN THE MID-LEVEL SUBTROPICAL
RIDGE...WITH THE RIDGE CURRENTLY WELL ESTABLISHED AT MID- TO UPPER
LEVELS TO THE NORTHWEST OF THE CYCLONE. THIS PATTERN IS IMPARTING
A NORTHERLY FLOW OF VERY DRY AIR AT UPPER LEVELS OVER IRENE THAT IS
HINDERING DEVELOPMENT. GLOBAL MODELS INDICATE THAT THIS UPPER FLOW
SHOULD TRANSITION TO SOUTHEASTERLIES OVER THE NEXT COUPLE OF DAYS
AS IRENE MOVES CLOSER TO...AND TO THE NORTHEAST OF THE UPPER LOW
CURRENTLY NEAR 30N/73W. SOME RESTRENGTHENING IS THEREFORE SHOWN IN
THE OFFICIAL FORECAST. HOWEVER...THIS STRENGTHENING IS
CONSIDERABLY LESS THAN INDICATED BY THE SHIPS GUIDANCE...WHICH
BRINGS IRENE TO NEARLY HURRICANE STRENGTH IN FIVE DAYS. AN
OPPOSING VIEW IS PROVIDED BY THE GFDL MODEL...WHICH DISSIPATES
IRENE WITHIN 24 HOURS. AS IRENE HAS PERSERVERED THROUGH AN
ENVIRONMENT SEEMINGLY MORE HOSTILE THAN WHAT IT IS CURRENTLY
EMBEDDED IN...I AM GETTING LESS HOPEFUL ABOUT THE DISSIPATION
OPTION.

THE INITIAL MOTION IS 270/10. THE MID-LEVEL SUBTROPICAL
RIDGE...CURRENTLY CENTERED NEAR BERMUDA...IS FORECAST BY THE
GFS...UKMET...NOGAPS...AND CANADIAN MODELS TO MOVE SOUTHWESTWARD
AND/OR SPLIT AND WEAKEN OVER THE NEXT THREE DAYS. ALL OF THESE
MODELS SHOW A SHORT WAVE TROUGH IN THE WESTERLIES MOVING INTO THE
WESTERN ATLANTIC IN ABOUT THREE DAYS...AND THESE MODELS ALL LIFT
IRENE...OR ITS REMNANTS...NORTHWESTWARD WITH THE APPROACH OF THIS
TROUGH. THE 00Z RUNS OF THE UKMET AND NOGAPS MODELS...HOWEVER...
LEAVE IRENE TO LINGER BEHIND AS THE TROUGH PROGRESSES EASTWARD.
THERE IS ALSO A CURIOUS SEPARATION BETWEEN THE SINGLE-LAYER BAM
MODELS AND THE MULTI-LEVEL GLOBAL MODELS...WITH THE BAM MODELS ALL
SHOWING A MORE STRAIGHT-LINE WEST-NORTHWESTERLY TRACK THROUGH THE
FIVE DAY PERIOD. AMONG THE BAM MODELS...THE SHALLOW BAM HAS THE
MOST NORTHERLY TRACK...WHICH IS CONSISTENT WITH THE NORTHERLY
UPPER-LEVEL FLOW CURRENTLY OVER THE TROPICAL CYCLONE. THE OFFICIAL
FORECAST HAS BEEN SHIFTED JUST A LITTLE TO THE WEST OF THE PREVIOUS
ADVISORY AND IS ALSO SLOWER AT DAYS 4 AND 5. THE OFFICIAL FORECAST
LIES CLOSE TO THE LEFT EDGE OF THE GLOBAL MODEL GUIDANCE
ENVELOPE...AND IS ALSO CLOSE TO THE SHALLOW BAM FOR THE FIRST 72
HOURS.

FORECASTER FRANKLIN


FORECAST POSITIONS AND MAX WINDS

INITIAL 09/0900Z 22.5N 53.6W 30 KT
12HR VT 09/1800Z 22.5N 55.2W 30 KT
24HR VT 10/0600Z 23.0N 57.4W 35 KT
36HR VT 10/1800Z 23.9N 59.4W 35 KT
48HR VT 11/0600Z 25.2N 61.4W 40 KT
72HR VT 12/0600Z 27.5N 64.5W 40 KT
96HR VT 13/0600Z 29.0N 65.5W 45 KT
120HR VT 14/0600Z 30.0N 66.0W 45 KT


$$

[Coredesat]

THE NEXT ADVISORY ON IRENE WILL BE ISSUED BY THE
NWS/HYDROMETEOROLOGICAL PREDICTION CENTER AT 11 AM AST.

Why are they handing this off to them?

That's a good question. That's really odd. Unless some anomaly is expected to teleport Irene onto land in the next few hours.

[gkrangers]

THE NEXT ADVISORY ON IRENE WILL BE ISSUED BY THE
NWS/HYDROMETEOROLOGICAL PREDICTION CENTER AT 11 AM AST.

Why are they handing this off to them?

That's a good question. That's really odd. Unless some anomaly is expected to teleport Irene onto land in the next few hours.

I'm assuming they use some kind of automated system to generate the advisories. Probably accidentally picked HPC instead of TPC/NHC at some point of the process?...it is 5AM, after all.

[HURAKAN]

LA PROXIMA ADVERTENCIA SERA EMITIDA POR EL CENTRO NACIONAL DE
HURACANES A LAS 11 AM AST.


In the Spanish part says that the next advisory will be issued at 11 by the NHC.

[Andrew92]

I find it very interesting that the 11 AM advisory is taking longer than usual.

-Andrew92

[cycloneye]

WTNT44 KNHC 091446
TCDAT4
TROPICAL DEPRESSION IRENE DISCUSSION NUMBER 20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
ISSUED BY THE HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
11 AM EDT TUE AUG 09 2005

THERE CONTINUES TO BE DEEP CONVECTION ASSOCIATED WITH IRENE WITH THE
SYSTEM LOOKING BETTER THAN IT DID 6 HOURS AGO. WOULD PREFER TO SEE
A LITTLE MORE ORGANIZATION TO THE CONVECTION BEFORE UPGRADING IRENE
TO A TROPICAL STORM GIVEN DVORAK ESTIMATES OF 30 KTS.

IRENE IS CURRENTLY UNDER THE INFLUENCE OF NORTHWESTERLY FLOW AT
UPPER LEVELS WITH A TROF CURRENTLY IN PLACE TO THE NORTH AND EAST
OF THE SYSTEM. WITHIN THE NEXT 24 TO 36 HOURS...THE MOTION OF
IRENE WILL BRING IT FAR ENOUGH WEST TO BRING UNDER THE INFLUENCE OF
AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 28N AND 64W. THIS SHOULD
ALLOW FOR AN ENVIRONMENT WITH LESS SHEAR. THE SYSTEM IS CURRENTLY
FORECAST TO REACH TROPICAL STORM STATUS AT 36HRS.

THE INITIAL MOTION IS 280/9. THE 0000 UTC ECMWF...NOGAPS AND UKMET
MODELS ARE ALL IN THE SAME BALLPARK WITH THE TRACK OF THIS SYSTEM
TAKING IT GENERALLY ON A WEST TO WEST-NORTHWESTERLY TRACK WITH TIME
WITH A SLIGHT WESTWARD TREND NOTED. THE GFS WAS QUITE THE OPPOSITE
SHOWING THE SYSTEM SHEARING APART AS IT TOOK A MORE NORTHERLY
TRACK. WILL LEAN STRONGLY TOWARDS THE FORMER SOLUTION AND FOR NOW
BE SOMEWHAT CONSERVATIVE WITH INTENSIFICATION GIVEN THE MODEL
DIFFERENCES. THE OFFICIAL TRACK TAKES THE SYSTEM ON A MORE
WESTERLY COURSE THAN THE PREVIOUS TRACK BASED ON THE AFOREMENTIONED
MODEL TREND.

FORECASTER KORTY


FORECAST POSITIONS AND MAX WINDS

INITIAL 09/1500Z 22.3N 53.9W 30 KT
12HR VT 10/0000Z 22.7N 55.4W 30 KT
24HR VT 10/1200Z 23.6N 57.9W 30 KT
36HR VT 11/0000Z 25.0N 60.3W 35 KT
48HR VT 11/1200Z 26.3N 62.6W 40 KT
72HR VT 12/1200Z 27.7N 64.6W 50 KT
96HR VT 13/1200Z 29.1N 66.2W 55 KT
120HR VT 14/1200Z 30.0N 67.1W 55 KT


A Different branch HPC took over but 57,Derek why they did that?

[Frank2]

Re: Andrew92's post

The quarter probably rolled under a piece of computer equipment...

Kidding,

Frank

[Brent]

I've seen NWS offices do that before(have another office issue products). Probably hardware upgrades...

[Coredesat]

A Different branch HPC took over but 57,Derek why they did that?

We were asking that after the 5 AM advisory. That's kind of weird for the HPC to up and take control like that when the storm hasn't even made landfall yet.

[gatorcane]

BE SOMEWHAT CONSERVATIVE WITH INTENSIFICATION GIVEN THE MODEL DIFFERENCES. THE OFFICIAL TRACK TAKES THE SYSTEM ON A MORE WESTERLY COURSE THAN THE PREVIOUS TRACK BASED ON THE AFOREMENTIONED MODEL TREND.

Here comes Irene

[Scorpion]

Also conservatively forecasting it to get to 65 mph with plenty of warm water and favorable conditions ahead of it.