ATL: BRET - Remnants - Discussion

[KWT]

Hmm the models are pretty much in agreement with a track to the NE/NNE and given its been moving slowly eastwards recently I think its a decent enough call.

[GCANE]

MIMIC-TPW showing a quick deepening convergence.

However, looks like dry air will start becoming an issue.

[GCANE]

There were a few bursts of moderate to high rain rate cells overnight; but nothing at the hot-tower level.

A big issue is that 200mb vorticity is high and closeby due to the trough.

UL winds are starting to move across the COC.

This is tilting the PV column, so any convection will create a downdraft which will inhibit boundary-layer inflow under it.

IMHO, Bret may have reached a peak and looks like will be swept NE out to sea.

[GCANE]

CIMSS recorded some nice overshooting tops at sunset last night.

Deeper convection to the east of the LLC due to UL winds coming from the west.

[wxman57]

"accelerating south", "the NHC didn't expect Bret to move this far south"?? Bret has moved a mere 0.4 south in 12 hours. That's 24 miles south, and it's pretty much precisely as was forecast (within 0.1 or 0.2 degrees). Now Bret IS a tad farther east than was forecast, but not very much. We're only talking tenths of a degree here. Bret was forecast to drift slowly southward overnight, which it has. There is absolutely no reason to think it's going to move west into the Gulf.

As for the best models to use, throw out the BAMs. They're not good to use out of the deep tropics where the steering patterns might change. Stick with the dynamic models (GFS, Euro, Canadian, UK, GFDL). I don't have any confidence in the new HWRF yet - too many bugs.

[beoumont]

Wake up and smell the bomb: (Bahama Bomba)

[TheBurn]

Dry air sneaking in?

[AHS2011]

I understand that this is unofficial forecast blog, but I'll ask anyway. What are the chances that Tropical Storm Bret will become a hurricane?

[brunota2003]

Most of what you see on visible is just convective debris (left overs of storms, anvils/cirrus clouds, etc). IR is still unimpressive.

[HURAKAN]

I understand that this is unofficial forecast blog, but I'll ask anyway. What are the chances that Tropical Storm Bret will become a hurricane?

21%

[wxman57]

I understand that this is unofficial forecast blog, but I'll ask anyway. What are the chances that Tropical Storm Bret will become a hurricane?

I'd say there's a fair chance of that. Current forecast is for a max of 65 mph, but the forecast is only for 12-hr points for the first 48 hours and 24 hours points after then. Considering that and a typical intensity forecast error of about 10-15 mph per day, hurricane intensity is quite possible. Probably considerably higher than 21%.

[plasticup]

I understand that this is unofficial forecast blog, but I'll ask anyway. What are the chances that Tropical Storm Bret will become a hurricane?

http://www.nhc.noaa.gov/storm_graphics/AT02/refresh/AL0211T+gif/083515P_sm.gif

21%

Not to be picky, but there is a 21% chance that Bret will be a hurricane at 36 hours. It may also be a hurricane at other times and not at 36 hours. I'd say, based on the NHC intensity estimates, that the cumulative probability is about 30-35%.

[Dean4Storms]

Could reach hurricane status today IMO with the increase in convection if it persists. Amazing how the models for the most part (ECMFW had a slight pickup then dropped it) missed Bret. Seems these trough tail end small systems give the models fits.

[HURAKAN]

18/1145 UTC 27.5N 77.4W T3.0/3.0 BRET -- Atlantic

45 knots

[Ivanhater]

Convection expanding

[plasticup]

Stable intensity, despite the convection of the last hour:

INIT 18/1500Z 27.7N 77.3W 45 KT 50 MPH

[jhpigott]

Had a couple, of what looked like on the radar, outer rain bands move through the NE part of Palm Beach County. Not too much wind, but dumped a decent amount of rain in a short period.

Keeping my fingers crossed that we get a couple more bands that move through . . . need all the rain we can get.

[cycloneye]

TROPICAL STORM BRET DISCUSSION NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL AL022011
1100 AM EDT MON JUL 18 2011

THE CLOUD PATTERN OF THE STORM HAS NOT CHANGED APPRECIABLY IN
ORGANIZATION THIS MORNING. THE MAIN BANDING FEATURES ARE WELL
REMOVED FROM THE CENTER OVER THE NORTHEAST QUADRANT...AND A
SOMEWHAT RAGGED-LOOKING CDO TYPE FEATURE IS EVIDENT. UPPER-LEVEL
OUTFLOW CONTINUES TO BE SUPPRESSED OVER THE NORTHWESTERN PART OF
THE CIRCULATION. DVORAK INTENSITY ESTIMATES ARE 35 KT AND 45 KT
FROM TAFB AND SAB RESPECTIVELY...AND THE CURRENT INTENSITY ESTIMATE
IS HELD AT 45 KT. ANOTHER AIR FORCE HURRICANE HUNTER MISSION IS
SCHEDULED TO INVESTIGATE BRET THIS AFTERNOON. THE ATMOSPHERIC
ENVIRONMENT SHOULD BE MARGINALLY CONDUCIVE FOR STRENGTHENING TODAY
AND TONIGHT...WITH DRY AIR AND MODERATE VERTICAL SHEAR AS
MITIGATING FACTORS. SOME INTENSIFICATION IS FORECAST WITHIN THE
NEXT DAY OR SO...BUT AFTERWARDS INCREASING SHEAR IS LIKELY TO CAUSE
A WEAKENING TREND. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO
THE CONSENSUS OF THE INTENSITY GUIDANCE...AND TO THE PREVIOUS NHC
FORECAST.

BASED ON THE LATEST FIXES...THE CENTER APPEARS TO BE MOVING SLOWLY
NORTH-NORTHEASTWARD OR 030/4. THE TRACK FORECAST REASONING IS
ESSENTIALLY UNCHANGED FROM THE PREVIOUS ADVISORY PACKAGE. A
BUILDING MID-LEVEL RIDGE TO THE SOUTHEAST OF BRET ALONG WITH A
BROAD TROUGH OFF THE NORTHEAST U.S. COAST SHOULD CAUSE A
NORTH-NORTHEASTWARD TO NORTHEASTWARD MOTION WITH A GRADUAL INCREASE
IN FORWARD SPEED OVER THE NEXT SEVERAL DAYS. LATER IN THE FORECAST
PERIOD...A TURN TO THE EAST-NORTHEAST WITH SOME ADDITIONAL
ACCELERATION IS FORECAST AS THE CYCLONE BECOMES MORE EMBEDDED IN
THE HIGHER LATITUDE WESTERLIES. THE OFFICIAL TRACK FORECAST IS AN
UPDATE OF THE PREVIOUS ONE.

FORECAST POSITIONS AND MAX WINDS

INIT 18/1500Z 27.7N 77.3W 45 KT 50 MPH
12H 19/0000Z 28.2N 77.0W 50 KT 60 MPH
24H 19/1200Z 29.2N 76.4W 55 KT 65 MPH
36H 20/0000Z 30.2N 75.7W 55 KT 65 MPH
48H 20/1200Z 31.4N 74.0W 50 KT 60 MPH
72H 21/1200Z 33.5N 70.0W 45 KT 50 MPH
96H 22/1200Z 36.0N 64.5W 35 KT 40 MPH
120H 23/1200Z 38.5N 58.5W 30 KT 35 MPH

$$
FORECASTER PASCH

[wxman57]

Stable intensity, despite the convection of the last hour:

INIT 18/1500Z 27.7N 77.3W 45 KT 50 MPH

Convective tops have warmed considerably over the past 6 hours. No data to support an increase in intensity. Recon will be there in a few hours.

[eastcoastFL]

I was up in palm beach gardens this morning and now i am home in wellington and we have seen a few bands pass through during our travels this morning. Sure is great to see those big fluffy storm clouds rotating in the sky, I missed it! And its even better to see it as a nice little ts well off our coast moving the other way