40 replies to this topic

[Somerset Squall]

94E has become Tropical Storm Celia off the south coast of Mexico, with intensity at 35kts. Celia has some good banding but lacks convection in the eastern quadrant at present. However, once this problem is eradicated, Celia sits in a very favourable environment for strengthening. Shear is very low, waters are around 30C and outflow is excellent. NHC notes the chance for rapid strengthening, and it is likely Celia will become a hurricane in the next day or so on the westward track. A peak of 75kts is expected before shear increases, but worth noting is Celia will remain over very warm waters (as the storm is at low lattitude) for the next 5 days and if shear doesn't increase then Celia could become a major hurricane.

[kold weather]

Yeah not much to really add there SS, the system has a very neat looking structure with some good banding and wrapping of the convection right into the center. It probably needs a decent convective burst to really push it onwards and I'd expect the usual Durinal flare-up to occur in the early morning hours.

Conditions looks decent aloft and clearly the waters are good enough for further development so I see no reason why this can't develop further into a hurricane. The Ships on the 12z run got this upto 90kts, however on the other hand the GFDL/HWRF strengthen the system only out to about 48hrs so they both must be seeing some shear aloft which weakens the system. There is a jet streak close to where the models forecast the system to be which maybe over the top of the system on the GFDL/HWRF runs, so its a solution that could prevent any strengthening past 36-48hrs, needs to be watched. I'd still expect a hurricane though even if that solution does occur, if the shear isn't too strong and doesn't get in the way then something between 85-95kts would be quite possible.

Edit---system appears to be much more advanced then first believed, proto eye already showing through a recently developed CDO though the eastern eyewall is still very weak... still its probably already close to hurricane status given the Vis imagery, looks like the convective burst has just kicked in during the last few hours over the center. This does increase the odds of a major hurricane as well it has to be said.

Edited by kold weather, 19 June 2010 - 21:40 .

[john w]

Agree on the development of Celia, convective action through the night should start boost intensification, any likely shear looks set to go away in the next 48 hours and old Blas looks too far away to give any hinderance for development.

New to the hurricane watching thread, understand the basics but not the technics and my meto knowledge is mainly UK biased. See you about in the summer

[Gray-Wolf]

john w, on 20 June 2010 - 12:54 , said:

New to the hurricane watching thread, understand the basics but not the technics and my meto knowledge is mainly UK biased. See you about in the summer

Hi john! welcome! What a season to join us.......lets hope July kicks things off with a vengeance!!!

[john w]

Thanks Grey. Im a little new to the whole tropical storm stuff and thought its time to learn, ive only ever really concentrated on air mass and pressure from a now cast point of view. So development is a completely new thing but hey, got to start somewhere and understand all the feedback loops vorticity, shear tropical waves etc etc.

Expect some daft questions over the season.

[summer blizzard]

000
WTPZ44 KNHC 202038
TCDEP4
HURRICANE CELIA DISCUSSION NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042010
200 PM PDT SUN JUN 20 2010

SATELLITE IMAGERY INDICATES THAT CELIA HAS INTENSIFIED. A SSMIS
PASS FROM 1450 UTC SHOWED THE DEVELOPMENT OF A PARTIAL EYEWALL AND
AN EYE HAS BEEN INTERMITTENTLY SEEN IN VISIBLE IMAGERY. ALSO...
MICROWAVE IMAGERY SUGGESTS THAT THE LOW-LEVEL AND MID-LEVEL CENTERS
HAVE BECOME MORE VERTICALLY ALIGNED SINCE THIS MORNING. BASED ON
THESE TRENDS AND A DVORAK CI NUMBER OF 4.0 FROM TAFB...THE INITIAL
INTENSITY IS SET AT 65 KT FOR THIS ADVISORY.

THE SHIPS MODEL INDICATES THAT THE EASTERLY SHEAR CURRENT THAT HAS
BEEN AFFECTING CELIA WILL GRADUALLY DECREASE OVER THE NEXT 24
HOURS. THIS SHOULD ALLOW CELIA TO TAKE ADVANTAGE OF THE OTHERWISE
FAVORABLE CONDITIONS FOR INTENSIFICATION OVER THE NEXT COUPLE OF
DAYS. THE OFFICIAL INTENSITY FORECAST HAS BEEN ADJUSTED UPWARD AND
IS IN CLOSE AGREEMENT WITH THE SHIPS MODEL. A BROAD PEAK IN
INTENSITY IS INDICATED LATER IN THE PERIOD...FOLLOWED BY SOME
WEAKENING BY DAY 5 AS CELIA IS FORECAST TO MOVE INTO AN AREA OF
COOLER WATERS AROUND THAT TIME. IT IS WORTH NOTING THAT THE SHIPS
RAPID INTENSIFICATION INDEX SHOWS ABOUT A 30 PERCENT CHANCE OF 25
KT OF INTENSIFICATION IN THE NEXT 24 HOURS...BUT ONLY A 2 PERCENT
CHANCE OF 30 KT OR MORE IN THAT PERIOD.

THE CENTER OF CELIA MOVED A LITTLE TO THE SOUTH OF THE PREVIOUS
FORECAST TRACK OVER THE PAST FEW HOURS...BUT THE LONG TERM INITIAL
MOTION ESTIMATE REMAINS 260/6. THE TRACK FORECAST REASONING
REMAINS UNCHANGED...AS CELIA WILL BE STEERED GENERALLY WESTWARD FOR
THE NEXT 2 OR 3 DAYS BY A DEEP-LAYER RIDGE NORTH OF THE CYCLONE.
BEYOND THAT TIME...THE GLOBAL MODELS SUGGEST THAT A MID- TO
UPPER-LEVEL TROUGH WILL AMPLIFY OFF THE U.S. WEST COAST BY THE END
OF THE PERIOD. THIS SHOULD ALLOW CELIA TO TURN MORE WEST-
NORTHWESTWARD AS THE SUBTROPICAL RIDGE WEAKENS. THE NEW TRACK
FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS PACKAGE BUT WAS
SHIFTED SOUTHWARD TO ACCOUNT FOR THE MORE SOUTHERLY INITIAL
POSITION OF THE CYCLONE. THE OFFICIAL FORECAST IS CLOSE TO THE
CONSENSUS OF THE DYNAMICAL MODELS EXCLUDING THE GFS...WHICH AGAIN
APPEARS TO BE A SOUTHERLY OUTLIER.

THE 34-KT WIND RADII IN THE NORTHEASTERN QUADRANT WERE EXPANDED
BASED ON AN ASCAT PASS FROM 1640 UTC.

FORECAST POSITIONS AND MAX WINDS

INITIAL 20/2100Z 11.6N 100.3W 65 KT
12HR VT 21/0600Z 11.4N 101.3W 75 KT
24HR VT 21/1800Z 11.4N 102.5W 85 KT
36HR VT 22/0600Z 11.5N 103.7W 90 KT
48HR VT 22/1800Z 11.6N 105.1W 100 KT
72HR VT 23/1800Z 12.3N 108.5W 100 KT
96HR VT 24/1800Z 13.5N 112.5W 100 KT
120HR VT 25/1800Z 15.0N 116.0W 90 KT

$$
FORECASTER BRENNAN

Forecasted to become a major category 3 hurricane.

http://www.ssd.noaa....lt/t7/vis-l.jpg
http://www.ssd.noaa....flt/t7/wv-l.jpg

Pulling dry air on its eastern side, but on the whole looks very impressive.

[kold weather]

Don't worry John its all fun trying to figure out these things, they throw of us all off more often then we'd like no matter how much you think you know!

Anyway Celia has strengthened into a Hurricane in the last few hours. An eye is still trying to pop out with the downward pluses of convection, recently the eye has been covered under the CDO again. The structure looks very good right now and the system is wrapping around very nicely indeed with the eyewall still trying to develop, probably being hampered by the shear. Also worth noting the outflow on the southern side of the system looks like it has rather markedly improved in the last few hours.

No reason for me to go against the NHC/models general thinking, something between 90-100kts seems reasonable to me, I'd be surprised if it goes much higher then that range though there is a chance of that given conditions are decent, the weak easterly shear still clearly is present which will be a limiting factor.

Edited by kold weather, 20 June 2010 - 21:46 .

[Somerset Squall]

It appears easterly shear has risen over Celia this morning. Intensity was at 70kts overnight, but Celia is now barely a hurricane with intensity decreasing to 65kts. The eye is no longer visable on satellite imagery, and the CDO is rather irregular in shape. However, this shear is expected to ease which should allow Celia to resume strengthening. I think Celia still has a shot at becoming a major hurricane, though I am a little less confident about this than I was before.

[Somerset Squall]

Despite some moderate shear, Celia has resumed strengthening this evening and intensity has risen to 80kts, putting the hurricane close to cat 2 status. The eye is cloud obscured and is only fleeting in appearance in satellite imagery. The majority of the convection and banding resides in the western quadrant of Celia as easterly shear continues to effect the system. The shear however could well be helping fan the westward outflow which may have in fact aided Celia's recent intensification. Shear will ease overnight, and therefore further intensification is likely and there is a fair chance Celia could become a major hurricane before gradually turning west-northwestwards into cooler waters.

[Somerset Squall]

Celia has continued to strengthen, and is now a 90kt cat 2. Celia is forecast to become a major hurricane in the next 24hrs as shear is expected to finally ease and due to the fact that Celia already has a well defined, if cloud obscured, eye. Beyond 48hrs, the ridge to the north of the hurricane driving it westwards will gradually weaken which will allow Celia to gain lattitude. At the same time, this will send Celia over much cooler waters which will initiate a firm weakening trend.

[Somerset Squall]

CDO becoming much more circular, eye beginning to pop out from behind the cloud obstruction, all signs that Celia could be a major soon...

Attached Thumbnails

• 

[cookie]

thanks for the updates guys

nice system this one

[Somerset Squall]

Celia has not yet attained major hurricane status and has remained in a fairly steady state. Current intensity is 85kts. Shear has been a problem for Celia, and although it hasn't been strong enough to cause significant weakening, it has prevented the hurricane from strengthening further. However, the shear is expected to ease yet again which may favour some re-strengthening, and indeed a recent satellite imagery shows the eye clearing out very nicely, Celia is defintely the best she has looked so far! Celia will feel a weakeness in the ridging to the north beyond 48hrs and will therefore turn towards the northwest into cooler waters which will initiate weakening beyond this time frame.

Attached Thumbnails

• 

[Paranoid]

Now a major hurricane. Predicted to strengthen to Cat 4 with 135mph winds before weakening.

000
WTPZ34 KNHC 232038
TCPEP4
BULLETIN
HURRICANE CELIA ADVISORY NUMBER 19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042010
200 PM PDT WED JUN 23 2010

...CELIA BECOMES A MAJOR HURRICANE...


SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...12.3N 110.4W
ABOUT 735 MI...1180 KM S OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/HR
PRESENT MOVEMENT...W OR 280 DEGREES AT 13 MPH...20 KM/HR
MINIMUM CENTRAL PRESSURE...963 MB...28.44 INCHES


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


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 200 PM PDT...2100 UTC...THE CENTER OF HURRICANE CELIA WAS LOCATED
NEAR LATITUDE 12.3 NORTH...LONGITUDE 110.4 WEST. CELIA IS MOVING
TOWARD THE WEST NEAR 13 MPH...20 KM/HR. A TURN TOWARD THE
WEST-NORTHWEST IS EXPECTED DURING THE NEXT DAY OR SO.

MAXIMUM SUSTAINED WINDS ARE NEAR 115 MPH...185 KM/HR...WITH HIGHER
GUSTS. CELIA IS A CATEGORY THREE HURRICANE ON THE SAFFIR-SIMPSON
HURRICANE WIND SCALE. SOME ADDITIONAL STRENGTHENING IS POSSIBLE
DURING THE NEXT DAY OR SO.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 35 MILES...55 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115
MILES...185 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 963 MB...28.44 INCHES.


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


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...800 PM PDT.

$$
FORECASTER CANGIALOSI/STEWART

[Somerset Squall]

Indeed Paranoid, the eye has really cleared out and this is a base, along with low shear and warm waters, for further intensification. Current intensity is 100kts, and I agree with NHC that at least a low end cat 4 looks likely before weakening begins.

[cookie]

[Paranoid]

A lot of very deep convection on that image there. Satellite presentation looks a lot better than it did 6 or so hours ago.

[cookie]

lost its eye

[Paranoid]

Back up to Major Hurricane again, probably underwent an eyewall replacement given the loss of the eye overnight.

000
WTPZ34 KNHC 241434
TCPEP4
BULLETIN
HURRICANE CELIA ADVISORY NUMBER 22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042010
800 AM PDT THU JUN 24 2010

...CELIA STRENGTHENS TO A MAJOR HURRICANE AGAIN ...


SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...12.5N 113.9W
ABOUT 765 MI...1230 KM SSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/HR
PRESENT MOVEMENT...W OR 275 DEGREES AT 13 MPH...20 KM/HR
MINIMUM CENTRAL PRESSURE...962 MB...28.41 INCHES


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


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 AM PDT...1500 UTC...THE CENTER OF HURRICANE CELIA WAS LOCATED
NEAR LATITUDE 12.5 NORTH...LONGITUDE 113.9 WEST. CELIA IS MOVING
TOWARD THE WEST NEAR 13 MPH...20 KM/HR. A TURN TOWARD THE
WEST-NORTHWEST IS EXPECTED OVER THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 115 MPH...185
KM/HR...WITH HIGHER GUSTS. CELIA IS A CATEGORY THREE HURRICANE ON
THE SAFFIR-SIMPSON HURRICANE WIND SCALE. SOME ADDITIONAL
STRENGTHENING IS POSSIBLE TODAY...FOLLOWED BY GRADUAL WEAKENING ON
FRIDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115
MILES...185 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 962 MB...28.41 INCHES.


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


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...200 PM PDT.

$$
FORECASTER CANGIALOSI/PASCH

[cookie]