TC Bertha

[Aric Dunn]

if this continues .. by tonight it will be a hurricane.. but i believe it is now.

[KWT]

Hmmm I think the winds probably haven't caught up yet Aric but that is no way a 45kt storm, if it is its one of the best I've seen recently!

Looks like it has a closed eyewall and a clear eye now showing even on Vis imagery, this must be well on the way to being hurricane Bertha in early July east of 50W, stunning!

I'd go for 55kts as well.

[txwatcher91]

:uarrow: Not yet, the full eye and eyewall is not a clear feature on IR.

Generally the eye does not clear out on IR until a hurricane/storm is near Cat 2 or 3 status. Probably not a hurricane yet, but could easily be by 2-3am tomorrow.

[Andrew92]

I'm guessing 50 kt.

[wxman57]

I could go with 50 or 55 kts looking at the latest satellite. One thing to consider is that it will begin encountering increasing shear from the TUTT tomorrow. That should cause some disorganization for a while.

[WmE]

Looks like it's at least at 55 kts.

[Squarethecircle]

:uarrow: Not yet, the full eye and eyewall is not a clear feature on IR.

Generally the eye does not clear out on IR until a hurricane/storm is near Cat 2 or 3 status. Probably not a hurricane yet, but could easily be by 2-3am tomorrow.

I didn't say clear out; there's no solid feature present at all.

[senorpepr]

They went with 50KT.

[HURAKAN]

Major re-writing by the NHC, I guess based on the delay.

[senorpepr]

TROPICAL STORM BERTHA FORECAST/ADVISORY NUMBER 15

ESTIMATED MINIMUM CENTRAL PRESSURE 998 MB MAX SUSTAINED WINDS 50 KT WITH GUSTS TO 60 KT.

[wxman57]

50 kts now 18.1N/47W. Still a little too far south an estimate, perhaps, but the storm may be tilted.

[Aric Dunn]

BERTHA STRENGTHENING...COULD BECOME A HURRICANE

[MiamiensisWx]

000
WTNT32 KNHC 062057
TCPAT2
BULLETIN
TROPICAL STORM BERTHA ADVISORY NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008
500 PM AST SUN JUL 06 2008

...BERTHA STRENGTHENING...COULD BECOME A HURRICANE...

AT 500 PM AST...2100Z...THE CENTER OF TROPICAL STORM BERTHA WAS
LOCATED NEAR LATITUDE 18.1 NORTH...LONGITUDE 47.0 WEST OR ABOUT 1055
MILES...1700 KM...EAST OF THE NORTHERN LEEWARD ISLANDS.

BERTHA IS MOVING TOWARD THE WEST-NORTHWEST NEAR 20 MPH...32 KM/HR.
A GENERAL WEST-NORTHWESTWARD MOTION WITH A GRADUAL DECREASE IN
FORWARD SPEED IS EXPECTED DURING THE NEXT COUPLE OF DAYS. IT IS
MUCH TOO EARLY TO DETERMINE IF BERTHA WILL EVENTUALLY AFFECT ANY
LAND AREAS.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 60 MPH...95
KM/HR...WITH HIGHER GUSTS. SOME ADDITIONAL STRENGTHENING IS
FORECAST AND BERTHA COULD BECOME A HURRICANE DURING THE NEXT DAY
OR TWO.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 998 MB...29.47 INCHES.

REPEATING THE 500 PM AST POSITION...18.1 N...47.0 W. MOVEMENT
TOWARD...WEST-NORTHWEST NEAR 20 MPH. MAXIMUM SUSTAINED WINDS...60
MPH. MINIMUM CENTRAL PRESSURE...998 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.

$$
FORECASTER BROWN

[senorpepr]

BERTHA STRENGTHENING...COULD BECOME A HURRICANE

BERTHA COULD BECOME A HURRICANE DURING THE NEXT DAY OR TWO.

[RL3AO]

TROPICAL STORM BERTHA DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008
500 PM EDT SUN JUL 06 2008

A COUPLE OF MICROWAVE IMAGES JUST RECEIVED SUGGEST THAT BERTHA'S
VORTEX IS TILTED A LITTLE. THE IMAGES INDICATE THAT THE
LOW-LEVEL CENTER IS LOCATED JUST SOUTHWEST OF THE MID-LEVEL CENTER.
HOWEVER...THESE IMAGES ALSO SUGGEST THAT THE OVERALL STRUCTURE HAS
IMPROVED WITH THE APPEARANCE OF AN EYE FEATURE...SUGGESTING THAT
BERTHA IS STRENGTHENING. DVORAK INTENSITY ESTIMATES WERE 45 KT AT
18Z...BUT WITH THE IMPROVING STRUCTURE THE INITIAL INTENSITY IS
INCREASED TO 50 KT. CONDITIONS APPEAR CONDUCIVE FOR STRENGTHENING
DURING THE NEXT COUPLE OF DAYS AND BERTHA COULD BECOME A HURRICANE.
HOWEVER...INDICATIONS ARE THAT BEYOND 48 HOURS...WESTERLY SHEAR
COULD HALT ANY ADDITIONAL STRENGTHENING AS SUGGESTED BY THE SHIPS
MODELS.

BERTHA IS MOVING WEST-NORTHWESTWARD OR 285/17 KT. ALL OF THE
AVAILABLE GUIDANCE SHOWS A NORTHWEST TURN AS THE RIDGE OVER THE
WESTERN ATLANTIC WEAKENS IN A FEW DAYS. HOWEVER...THERE REMAINS
SOME SPREAD IN THE GUIDANCE AS TO WHEN THE TURN OCCURS. THE HWRF
AND GFDL...WHICH DEPICT A STRONG TROPICAL CYCLONE REMAINS ALONG
THE EASTERN EDGE OF THE MODEL ENVELOPE. THE UKMET WHICH KEEPS
BERTHA WEAKER IS ALONG THE WESTERN EDGE. THE NEW TRACK
FORECAST IS ADJUSTED SLIGHTLY EASTWARD...BUT STILL REMAINS
WEST OF THE MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 06/2100Z 18.1N 47.0W 50 KT
12HR VT 07/0600Z 18.7N 49.6W 55 KT
24HR VT 07/1800Z 19.5N 52.3W 60 KT
36HR VT 08/0600Z 20.2N 54.6W 65 KT
48HR VT 08/1800Z 20.9N 56.7W 70 KT
72HR VT 09/1800Z 23.0N 60.5W 70 KT
96HR VT 10/1800Z 26.0N 64.0W 70 KT
120HR VT 11/1800Z 29.0N 65.5W 70 KT

$$
FORECASTER BROWN

[senorpepr]

Good call, Derek, on the T3.0+ (50KT)

[wxman57]

BERTHA STRENGTHENING...COULD BECOME A HURRICANE

BERTHA COULD BECOME A HURRICANE DURING THE NEXT DAY OR TWO.

Nothing new, it was already forecast to become a hurricane in a day or two.

[MiamiensisWx]

WNW movement is the most important tidbit from this advisory in regards to the CONUS and Bermuda threat, in my view. If this continues, we will likely observe a recurvature off the Southeast and a higher threat to Bermuda.

[KWT]

Yeah went with 50kts, if it keeps organising like it is though its going to be a hurricane sooner rather then later I reckon. I'd put the center a touch higher in latitude as well wxman57 but its not a huge deal really.

I think this will only continue to get better organised from now on given the waters its underneath are only going to increase, going to get higher and higher heat content from now on.

WNW is just a mean of the NW track taken earlier and the slight bend back to the west we've just seen recently.

[RL3AO]