Hurricane Danielle Western Atlantic

[srainhoutx]

HPC Caribbean Narrative...


TS DANIELLE...OVER THE TROPICAL ATLANTIC...IS FORECAST TO SLOWLY
COME UNDER INFLUENCE OF THE AFOREMENTIONED TUTT...WHICH SHOULD
STEER THIS SYSTEM AWAY FROM THE FORECAST AREA. THE LATEST NHC
GUIDANCE KEEPS THIS SYSTEM FAR FROM THE ISLANDS AND IT IS NOT
EXPECTED TO HAVE A MAJOR IMPACT ON THE FORECAST AREA. BUT IT WILL
BE WORTHWHILE TO MONITOR BUILDING RIDGE PATTERN ACROSS THE EASTERN
CARIBBEAN...AS IT COULD HAVE AN IMPACT ON HOW SOON THIS SYSTEM
TURNS TO THE NORTHWEST. MJO CONDITIONS REMAIN FAVORABLE ACROSS THE
FAR EASTERN TROPICAL ATLANTIC/AFRICA...WITH THE EWP MODEL SHOWING
THIS PERSISTING INTO THE END OF THE MONTH. THE CFS IS MORE
OPTIMISTIC...SHOWING FAVORABLE TO NEAR NEUTRAL CONDITIONS TO
PERSIST INTO THE MONTH OF SEPTEMBER. THUS FAR...THE CFS HAS BEEN
DOING A BETTER JOB THAN THE EWP MODEL.

[srainhoutx]

Looking better all the time. Appears an eye like feature may be forming as well...

[srainhoutx]

000
WTNT41 KNHC 231438
TCDAT1
TROPICAL STORM DANIELLE DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010
1100 AM AST MON AUG 23 2010

AT 1028 UTC...AN SSMIS MICROWAVE PASS INDICATED THAT DANIELLE WAS
STILL UNDER THE INFLUENCE OF EAST-NORTHEASTERLY SHEAR WITH THE
LOW-LEVEL CENTER LOCATED ON THE EASTERN EDGE OF THE DEEP
CONVECTION. HOWEVER...THE SHEAR APPEARS TO BE SLOWLY DECREASING...
AND CURVED BANDING HAS BECOME MORE PROMINENT OVER THE PAST FEW
HOURS. THE INITIAL INTENSITY IS RAISED TO 55 KT BASED ON DVORAK
FINAL T-NUMBERS OF 3.5 FROM TAFB AND SAB.

A FEW RECENT MICROWAVE IMAGES INDICATE THAT THE LOW-LEVEL CENTER IS
A LITTLE SOUTH OF PREVIOUS ESTIMATES...THE THE INITIAL MOTION IS
NOW 290/14. THE LONGWAVE PATTERN OVER THE ATLANTIC IS EXPECTED TO
CHANGE LITTLE OVER THE NEXT FEW DAYS...AND A BREAK IN THE
SUBTROPICAL RIDGE NEAR 45W SHOULD ALLOW THE CYCLONE TO TURN TOWARD
THE NORTHWEST WITHIN THE NEXT 36-48 HOURS. ONCE THIS HAPPENS...THE
RIDGE OVER THE WESTERN ATLANTIC IS EXPECTED TO BLOCK THE WESTWARD
MOVEMENT OF DANIELLE AND FORCE IT TO TURN NORTH-NORTHWESTWARD BY
DAY 5. THE MODEL GUIDANCE IS TIGHTLY CLUSTERED THROUGH DAY 5...AND
LITTLE CHANGE FROM THE PREVIOUS FORECAST WAS NEEDED. IT SHOULD BE
NOTED THAT THE TIGHT CLUSTERING OF THE MODEL GUIDANCE INDICATES THAT
CONFIDENCE IN THIS TRACK FORECAST IS HIGHER THAN NORMAL.

THE INTENSITY GUIDANCE CONTINUES TO SHOW STEADY STRENGTHENING
OVER THE NEXT 36 TO 48 HOURS WITH THE HELP OF LOW VERTICAL SHEAR AND
WARM OCEAN WATERS. AS COMPARED TO YESTERDAY...HOWEVER...THE SHIPS
AND LGEM STATISTICAL MODELS NOW SHOW MORE INTENSIFICATION THAN THE
GFDL AND HWRF DYNAMICAL MODELS. THE OFFICIAL FORECAST IS CLOSE TO
THE SHIPS AND LGEM MODELS FOR THE FIRST 72 HOURS BUT THEN VERY
CLOSE TO THE CONSENSUS AND PREVIOUS FORECAST THEREAFTER. THE RAPID
INTENSIFICATION INDEX IS CURRENTLY NEAR 40 PERCENT...SO THERE IS
SOME CHANCE THAT DANIELLE COULD STRENGTHEN A LITTLE FASTER DURING
THE NEXT 24 HOURS THAN INDICATED IN THE FORECAST. BY DAYS 3
THROUGH 5...VERTICAL SHEAR COULD INCREASE AS DANIELLE APPROACHES A
LONGWAVE TROUGH OVER THE WESTERN ATLANTIC... SO FOR NOW THE
INTENSITY IS HELD NEAR THE LOWER END OF CATEGORY 2 STRENGTH. THERE
IS NOW A 1 IN 4 CHANCE...HIGHER THAN YESTERDAY...THAT DANIELLE
COULD BECOME A MAJOR HURRICANE DURING THE NEXT 5 DAYS BASED ON
HISTORICAL NHC INTENSITY ERRORS.


FORECAST POSITIONS AND MAX WINDS

INITIAL 23/1500Z 15.1N 39.4W 55 KT
12HR VT 24/0000Z 16.0N 41.5W 65 KT
24HR VT 24/1200Z 17.3N 44.5W 75 KT
36HR VT 25/0000Z 18.9N 47.2W 80 KT
48HR VT 25/1200Z 20.8N 49.5W 85 KT
72HR VT 26/1200Z 24.5N 53.5W 90 KT
96HR VT 27/1200Z 27.0N 55.5W 90 KT
120HR VT 28/1200Z 29.5N 57.0W 90 KT

$$
FORECASTER BERG

[biggerbyte]

It is going to take a miracle/a drastic change to bring this system over land. As of today, everything coming from the Atlantic goes out to sea. There is always that chance this system could stall and miss the weakness. If that were to happen, the ridge would be in control, and westward she would go. We'll see.

[srainhoutx]

000
WTNT31 KNHC 232033
TCPAT1
BULLETIN
HURRICANE DANIELLE ADVISORY NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010
500 PM AST MON AUG 23 2010

...DANIELLE BECOMES A HURRICANE...THE SECOND OF THE ATLANTIC
SEASON...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...15.4N 41.5W
ABOUT 1320 MI...2120 KM E OF THE LESSER ANTILLES
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/HR
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 17 MPH...28 KM/HR
MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 PM AST...2100 UTC...THE CENTER OF HURRICANE DANIELLE WAS
LOCATED NEAR LATITUDE 15.4 NORTH...LONGITUDE 41.5 WEST. DANIELLE IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 17 MPH...28 KM/HR...AND IS
EXPECTED TO TURN TOWARD THE NORTHWEST BY TUESDAY NIGHT.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 75 MPH...120 KM/HR...
WITH HIGHER GUSTS. DANIELLE IS A CATEGORY ONE HURRICANE ON THE
SAFFIR-SIMPSON HURRICANE WIND SCALE. ADDITIONAL STRENGTHENING IS
FORECAST DURING THE NEXT 48 HOURS...AND DANIELLE IS FORECAST TO
BECOME A MAJOR HURRICANE BY WEDNESDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 10 MILES...20 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70
MILES...110 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 987 MB...29.15 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 PM AST.

$$
FORECASTER BERG

[biggerbyte]

Update for the evening, folks.

Still no change in the overall thinking, however, this storm has not yet started her march out to sea. It seems as if she may skip the first trough and wait on the second. If the second is missed as well...

We all know how these long range forecasts can go, and we know that sometimes what should happen based on any forecasting method can bust wide open. Daily checks on the forecast with this hurricane remain from Texas to Bermuda, with the likely focus for any landfall to be Atlantic.

Again, going out to sea is still being forecasted, but it is long range, and it is not absolutely set in stone.

[Ptarmigan]

Something tells me that Danielle will be a major hurricane soon.



Eyewall and eye are developing.

[Andrew]

If this motion of an almost completely western movement does not stop in the next day this storm will be to the south of the predicted points by hundreds of miles.

[biggerbyte]

For sure..

[Ptarmigan]

Satellite images of Danielle.







Looks like Danielle is intensifying.

[srainhoutx]

Looks like Danielle had a bit of a rough night. Appears that drier air has wrapped in and some weakening may be occurring.

[srainhoutx]

Saw Danielle, and Frank, who was the "E" storm?

Frank is the EPAC storm. Earl would be 96L off Africa if it is declared.

[srainhoutx]

Looking fairly ragged and an exposed center as well. Perhaps a downgrade to Tropical Storm?

[sleetstorm]

How can Hurricane Danielle be downgraded back to tropical storm status? It has strengthended to category 2 status at 5 a.m. this morning according to this news station's hurricane center.

***********************I RECTIFY MYSELF**************************

Because Hurricane Danielle was downgraded to 80 m.p.h. at 11 a.m. EDT. needless to say, it is still a hurricane.

[srainhoutx]

How can Hurricane Danielle be downgraded back to tropical storm status? It has strengthended to category 2 status at 5 a.m. this morning according to this news station's hurricane center.

NHC kept the intensity at 80 mph, but an interesting discussion of what has happened and what will likely cause Danielle to not become a Major Hurricane...

THE PERIOD OF RAPID INTENSIFICATION HAS ENDED WITH A THUD. THE
LOW-LEVEL CENTER OF DANIELLE HAS BECOME EXPOSED BETWEEN A RAGGED
CENTRAL DENSE OVERCAST TO ITS EAST...AND A BROKEN CONVECTIVE BAND
TO ITS WEST. ALL ALONG...MICROWAVE IMAGERY SINCE ABOUT 0300 UTC
SHOWED A DRY SLOT WRAPPING AROUND THE WESTERN AND SOUTHERN SIDE OF
THE CIRCULATION...AND AS A RESULT THE EYEWALL BECAME ERODED. DATA
T-NUMBERS HAVE FALLEN QUICKLY AND ARE NOW AS LOW AS T3.9 FROM THE
HURRICANE INTENSITY ESTIMATE...AN EXPERIMENTAL FORM OF THE UW-CIMSS
ADT. THE INITIAL INTENSITY IS LOWERED TO 70 KT AT THIS TIME...
WHICH COULD STILL BE GENEROUS. SHIPS GUIDANCE SHOWS WESTERLY TO
SOUTHWESTERLY SHEAR INCREASING TO BETWEEN 15 AND 20 KT OVER THE
NEXT 24 HOURS OR SO...AND IT IS UNCLEAR HOW WELL DANIELLE WILL BE
ABLE TO MIX OUT THE DRY AIR. ONLY SLOW STRENGTHENING IS INDICATED
IN THE OFFICIAL FORECAST...AND THE INTENSITY AT DAYS 4 AND 5 IS
HELD JUST BELOW MAJOR HURRICANE STRENGTH TO MAINTAIN SOME SORT OF
CONTINUITY...BUT THIS IS NOW ABOVE MANY OF THE INTENSITY MODELS.

[biggerbyte]

Still no changes, folks. Climo and model support remains intact for this storm to move out to sea. We still need to watch her until she is dead somewhere over the Atlantic. Bermuda may need to deal with this, however.

We'll see..

In the meantime, it looks like the system behind this one will become Earl. Earl will have a different enviroment and path than the girl before him. More on this in the proper threads.

Heads up..

[srainhoutx]

000
WTNT31 KNHC 242040
TCPAT1
BULLETIN
TROPICAL STORM DANIELLE ADVISORY NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010
500 PM AST TUE AUG 24 2010

...DANIELLE WEAKENS TO A TROPICAL STORM...EXPECTED TO BE
TEMPORARY...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.5N 48.2W
ABOUT 895 MI...1445 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/HR
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 18 MPH...30 KM/HR
MINIMUM CENTRAL PRESSURE...993 MB...29.32 INCHES

[AndrewLozeau]

Did you all see the weather channel and Jim Cantore discussing how Danielle has the possibility of hitting North East US? What is everyones opinion?

[srainhoutx]

Did you all see the weather channel and Jim Cantore discussing how Danielle has the possibility of hitting North East US? What is everyones opinion?

He must have seen the 18Z GFS...

http://www.nco.ncep.noaa.gov/pmb/nwprod ... el_l.shtml

[biggerbyte]

Depends on a few factors. One being how strong is the high pressure building into the n.e. going to be. This looks to be pretty stout. Also, there is some talk that another trough will be setting up, taking D. n.e. away from the mainland. Either way, D. looks to stay away from land, other than Bermuda.

Something to watch.