ATL: BRET - Remnants - Discussion

[TheBurn]

[KWT]

Looks surprisingly unimpressive on the WV there, not all that surprising given the amount of dry air still dotted to the NW/W of the system. Still no doubts about its strengthening over the past day.

Cool system either way!

[Rainband]

I like storms that just go fishing.

[supercane]

Latest microwave showing center surrounded by shallow convection:

[cycloneye]

00z Best Track

Remains at 55kts.

AL, 02, 2011071900, , BEST, 0, 285N, 768W, 55, 998, TS

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

[KWT]

Cool image, not the strongest of eyewalls and not closed but still a little stronger then was expected even if its peaked out at 55-60kts...

[Macrocane]

Bret looks impressive in microwave and the last visibles, but looks very unimpressive in IR and WV as some of you have mentioned. Let's see if D-max can strengthen it a little bit more or it could have peaked already.

[TwisterFanatic]

Really weakening this evening. Very little convection.

[HURAKAN]

Maybe some dry air intrusion

[x-y-no]

Maybe some dry air intrusion

Yes, no question about it.

May see some baroclinic enhancement when he gets picked up, but it look like he reached his peak as a tropical system this afternoon.

[cycloneye]

WTNT42 KNHC 190248
TCDAT2

TROPICAL STORM BRET DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL022011
1100 PM EDT MON JUL 18 2011

THE AIR FORCE RESERVE HURRICANE HUNTER MISSION FROM EARLIER THIS
AFTERNOON MADE ONE MORE PASS THROUGH THE CENTER OF BRET AFTER THE
RELEASE OF THE 2100 UTC ADVISORY AND ESSENTIALLY FOUND LITTLE
CHANGE TO THE WINDS. HOWEVER...THE CENTRAL PRESSURE INCREASED BY 1
MB ON EACH SUCCESSIVE PASS OF THE AIRCRAFT...AND THE INTENSITY OF
THE DEEP CONVECTION HAS BEEN ON A DOWNWARD TREND OVER THE PAST FEW
HOURS. THE INTENSITY ON THIS ADVISORY IS THEREFORE LOWERED TO 50
KT. MOST OF THE INTENSITY GUIDANCE STILL GIVES BRET THE OPPORTUNITY
FOR SOME RE-STRENGTHENING DURING THE NEXT 12 HOURS OR SO...AND THE
OFFICIAL FORECAST INDICATES THIS POSSIBILITY SHOULD THE DEEP
CONVECTION RE-DEVELOP OVERNIGHT. MORE CERTAIN WEAKENING SHOULD
COMMENCE BEYOND 24 HOURS AS THE VERTICAL SHEAR BECOMES INCREASINGLY
HOSTILE...AND BRET IS EXPECTED TO DISSIPATE WITHIN SOUTHWESTERLY
MID-LATITUDE FLOW SOUTH OF THE CANADIAN MARITIMES BY DAY 5.

BRET STILL APPEARS TO BE MOVING AT AN AVERAGE MOTION OF 030/6. THE
CYCLONE IS EXPECTED TO ACCELERATE NORTHEASTWARD AROUND THE
NORTHWESTERN PERIPHERY OF A MID-LEVEL HIGH...BUT THE TRACK GUIDANCE
IS A LITTLE SLOWER ON THIS MOTION FOR THIS FORECAST CYCLE. THE
ECMWF IS THE FASTEST OF THE GUIDANCE...BUT IT IS NOW 12 HOURS OLD
AND...ALONG WITH OFCI...FELL VERY NEAR THE EDGE OF THE GPCE CIRCLE
FAR FROM THE OTHER RELIABLE MODELS AT 72 HOURS. THE NEW OFFICIAL
TRACK FORECAST IS SHIFTED IN THE DIRECTION OF THE MODEL CONSENSUS
AND IS THEREFORE ON TRACK WITH BUT A LITTLE SLOWER THAN THE
PREVIOUS NHC FORECAST.

FORECAST POSITIONS AND MAX WINDS

INIT 19/0300Z 28.7N 76.6W 50 KT 60 MPH
12H 19/1200Z 29.5N 76.1W 55 KT 65 MPH
24H 20/0000Z 30.6N 75.1W 55 KT 65 MPH
36H 20/1200Z 31.7N 73.8W 50 KT 60 MPH
48H 21/0000Z 33.1N 71.9W 50 KT 60 MPH
72H 22/0000Z 36.0N 67.0W 40 KT 45 MPH
96H 23/0000Z 39.0N 59.0W 30 KT 35 MPH
120H 24/0000Z...DISSIPATED

$$
FORECASTER BERG

[HURAKAN]

just left

[TwisterFanatic]

Not to perty.

[JonathanBelles]

Reminder: We'll be in the chatroom till the early morning talking about recon. And an addition this year to the chatroom is music! Come join us!

viewtopic.php?p=1981943&f=59#p1981943

[Nimbus]

There was a lot of dry air in the southern part of that ridge which really halted development overnight. Looks like some moisture from the north getting pulled back in again this morning. Hope the ridge doesn't build too early and stall Brets exit out to sea.

[KWT]

Much weaker looking system now, though the structure still looks ok and if it can get some better convective coverage it could yet strengthen but I think we've seen the peak of Bret.

[NDG]

00z euro shows Bret to stay put in the area through tomorrow night.
By Tuesday night it shows the low level center to be east of Jacksonville start weakening while the mid level vorticity stays behind.
By Wednesday night it shows that it continues to weaken as it nears strong 30-40 knt NE shear east of the Carolinas.

ECMWF's run from a couple of nights ago was off on the timing by a good 12 hrs or so but was almost spot on by forecasting Brett to start weakening as it neared the 30th latitude and beyond.

[cycloneye]

For the record.


TROPICAL STORM BRET DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL AL022011
500 AM EDT TUE JUL 19 2011

DEEP CONVECTION HAS ALL BUT DISAPPEARED NEAR THE CENTER OF BRET IN
THE PAST FEW HOURS...LIKELY DUE TO THE ENTRAINMENT OF DRY AIR INTO
THE CYCLONE CORE AS SEEN IN SATELLITE IMAGERY AND DEWPOINT DATA
FROM THE AIR FORCE RESERVE UNIT HURRICANE HUNTER AIRCRAFT. THE
INITIAL INTENSITY IS LOWERED TO 45 KT BASED ON A 850-MB FLIGHT-
LEVEL WIND MAXIMUM OF 55 KT AND A PEAK SFMR WIND OF 43 KT. THE
DRIER ENVIRONMENT AND A FORECAST OF INCREASING VERTICAL WIND SHEAR
ARE NOT FAVORABLE FOR RESTRENGTHENING...AND THE INTENSITY GUIDANCE
SHOWS BRET SLOWLY WEAKENING FROM THIS POINT FORWARD. THE NEW NHC
FORECAST FOLLOWS THIS REASONING AND SHOWS LITTLE CHANGE THROUGH 12
HOURS FOLLOWED BY GRADUAL WEAKENING UNTIL DISSIPATION IN ABOUT 96
HOURS...IN BEST AGREEMENT WITH THE LGEM. HOWEVER...IF DEEP
CONVECTION DOES NOT RETURN...BRET COULD WEAKEN AND DISSIPATE MORE
QUICKLY THAN INDICATED HERE.

AIRCRAFT FIXES SUGGEST THAT THE LONG-TERM INITIAL MOTION IS TOWARD
THE NORTH-NORTHEAST OR 025 DEGREES AT AROUND 6 KT...A LITTLE TO THE
LEFT OF THE PREVIOUS FORECAST TRACK. OVERALL...THE TRACK FORECAST
REASONING REMAINS UNCHANGED AS BRET WILL GRADUALLY ACCELERATE TOWARD
THE NORTHEAST OVER THE NEXT COUPLE OF DAYS AS A MID-LEVEL RIDGE
BUILDS TO THE SOUTHEAST OF THE CYCLONE. THROUGH 48 HOURS...THE
GUIDANCE IS TIGHTLY CLUSTERED AND THE NEW OFFICIAL FORECAST HAS
BEEN ADJUSTED A LITTLE TO THE LEFT OF THE PREVIOUS ONE TO ACCOUNT
FOR THE INITIAL POSITION AND MOTION. AT 72 HOURS A MORE SUBSTANTIAL
ADJUSTMENT WAS MADE...TO THE LEFT OF AND SLOWER THAN THE PREVIOUS
NHC FORECAST...TRENDING TOWARD THE NEW MULTI-MODEL CONSENSUS.


FORECAST POSITIONS AND MAX WINDS

INIT 19/0900Z 29.3N 76.4W 45 KT 50 MPH
12H 19/1800Z 30.0N 75.8W 45 KT 50 MPH
24H 20/0600Z 30.9N 74.8W 40 KT 45 MPH
36H 20/1800Z 32.1N 73.4W 35 KT 40 MPH
48H 21/0600Z 33.6N 71.9W 35 KT 40 MPH
72H 22/0600Z 36.5N 68.0W 30 KT 35 MPH
96H 23/0600Z...DISSIPATED

$$
FORECASTER BRENNAN

[HURAKAN]

12z

AL, 02, 2011071912, , BEST, 0, 296N, 761W, 45, 1000, TS

Accelerating NE

[HURAKAN]

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