22 replies to this topic

[cookie]

95E has become Tropical Storm Darby




Last time their was 4 named storms by the end of June was 1991

[cookie]

Heading towards becoming a Hurricane

[Somerset Squall]

Like Celia, Darby is rapidly spinning up, with intensity now at 45kts. Ships model indicates greater than 40% risk of rapid intensification which is a high reading. Originally, shear was hindering Darby and was expected to prevent the storm from becoming a hurricane- however, now it appears shear is easing and will remain low. Therefore, Darby is likely to become a hurricane soon.

Darby is currently moving typically west-northwestwards. However, this storm needs watching very closely as it may interact with the large invest 93L in the Atlantic (KW describes this very well in the Atlantic Invest thread). This could send Darby northwards towards the coast as a strengthening hurricane. Needless to say, this is not a nice scenario.

[Somerset Squall]

Darby is strengthening rapidly and is expected to be a hurricane by morning. A CDO feature has rapidly developed and a fleeting eye is coming and going on satellite imagery. Intensity has increased to 55kts. Track is still expected to consist of a continuation of the west-northwesterly track folllowed by a turn to the north towards the coast of Mexico as Darby potentially interacts with invest 93L in the western Carribean. Based on current intensification and the projected low shear, don't be surprised to see Darby become the second major hurricane of the season.

[cookie]

Hurricane Celia and Darby

Edited by cookie, 23 June 2010 - 22:12 .

[Somerset Squall]

What a beautiful image! The East Pacific has certianly been active this June, an interesting watch! Let's hope Darby doesn't cause too much damage to Mexico.

[cookie]

Somerset Squall, on 23 June 2010 - 22:18 , said:

What a beautiful image! The East Pacific has certianly been active this June, an interesting watch! Let's hope Darby doesn't cause too much damage to Mexico.

Fingers crossed.

The East Pacific is the warm up to the main event I fear.

[Paranoid]

Looks like Darby still has an eye on that satellite picture. I'd wager Darby is probably a minimal hurricane now judging from that image.

[Paranoid]

We now have Hurricane Darby

000
WTPZ35 KNHC 241444
TCPEP5
BULLETIN
HURRICANE DARBY ADVISORY NUMBER 7...CORRECTED
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052010
800 AM PDT THU JUN 24 2010

CORRECTED PRESENT MOVEMENT FROM 284 DEGREES TO 285 DEGREES

...DARBY BECOMES A HURRICANE...


SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...12.8N 98.7W
ABOUT 235 MI...375 KM SSW OF PUERTO ESCONDIDO MEXICO
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/HR
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 9 MPH...15 KM/HR
MINIMUM CENTRAL PRESSURE...990 MB...29.23 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 DARBY WAS LOCATED
NEAR LATITUDE 12.8 NORTH...LONGITUDE 98.7 WEST. DARBY IS MOVING
TOWARD THE WEST-NORTHWEST NEAR 9 MPH...15 KM/HR...AND A GRADUAL
DECREASE IN FORWARD SPEED IS EXPECTED DURING THE NEXT COUPLE OF
DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 75 MPH...120 KM/HR...WITH HIGHER
GUSTS. DARBY IS A CATEGORY ONE HURRICANE ON THE SAFFIR-SIMPSON
SCALE. SOME ADDITIONAL STRENGTHENING IS FORECAST OVER THE NEXT DAY
OR TWO.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 10 MILES...20 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 50
MILES...85 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB...29.23 INCHES.


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


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

$$
FORECASTER PASCH

[cookie]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 24 JUN 2010 Time : 144500 UTC
Lat : 12:47:34 N Lon : 98:40:02 W


CI# /Pressure/ Vmax
4.3 / 973.5mb/ 72.2kt


Final T# Adj T# Raw T#
4.3 4.3 3.5

Latitude bias adjustment to MSLP : +3.5mb

Center Temp : -71.5C Cloud Region Temp : -63.5C

Scene Type : UNIFORM CDO CLOUD REGION

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : EAST PACIFIC
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : MW HOLD
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

[Somerset Squall]

Very strangely, similar to Celia this morning, Darby looked in a bad way. Convectional banding dissipated and only a small lobe of convection remained over the centre. Darby seems now to be rapidly intensifiying however- as intensity has risen to 65kts, making Darby a hurricane. I'm not entirely sure of this, but an extremely small eye looks to be developing on satellite imagery. If current trends continue, expect some big intensity gains over the next 24hrs. The turn to the north is now expected to happen later, and this may be because 93L is taking longer than expected to develop.

[summer blizzard]

Hurricane Darby is already drawing energy from both 93L and Celia, however as Celia moves away it will be drawn to the weakeness casused by 93L, and will be intresting to see how these two interact once the remenants make it into the Gulf.

[Somerset Squall]

Darby is a very small hurricane, and is therefore prone to some potentially rapid intensity changes. Current intensity is at 70kts, and I think the NHC could be a bit conservative in their forecast peak of 80kts. It also looks like Darby and 93L will probably not interact now, though 93L will weaken the steering ridge to the north of Darby which will force the hurricane northwards. NHC then mention that steering currents are likely to completely collapse leading to Darby stalling off the coast of Mexico. At this stage, Darby is likely to start weakening due to a forecast increase and shear and potentially some upwelling if stalling occurs.

Edited by Somerset Squall, 24 June 2010 - 23:13 .

[Paranoid]

Darby has become the second major hurricane of the season. NHC seems to have underestimated the potential for storms in this area to become intense.

000
WTPZ35 KNHC 251431
TCPEP5
BULLETIN
HURRICANE DARBY ADVISORY NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052010
800 AM PDT FRI JUN 25 2010

...DARBY BECOMES THE SECOND MAJOR HURRICANE OF THE EASTERN PACIFIC
SEASON...


SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...13.6N 101.2W
ABOUT 245 MI...395 KM SSW OF ACAPULCO MEXICO
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/HR
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 7 MPH...11 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 EYE OF HURRICANE DARBY WAS LOCATED
NEAR LATITUDE 13.6 NORTH...LONGITUDE 101.2 WEST. DARBY IS MOVING
TOWARD THE WEST-NORTHWEST NEAR 7 MPH...11 KM/HR. THIS MOTION IS
EXPECTED TO CONTINUE DURING THE NEXT 24 TO 36 HOURS BUT IT SHOULD
BEGIN TO MEANDER THEREAFTER.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 115 MPH...185
KM/HR...WITH HIGHER GUSTS. DARBY IS A CATEGORY THREE HURRICANE ON
THE SAFFIR-SIMPSON HURRICANE WIND SCALE. SOME FLUCTUATIONS IN
INTENSITY ARE LIKELY TODAY AND SATURDAY BUT A GRADUAL WEAKENING IS
FORECAST THEREAFTER.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 25 MILES...35 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70
MILES...110 KM.

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


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


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

$$
FORECASTER AVILA

[Somerset Squall]

Yes, I thought NHC were being too conservative. Put a small storm in a very favourable environment and it can grow quite quickly, just as Darby has. With small storms aswell however, they can fall apart just as quickly. Beyond 24hrs, shear will increase and this should cause rapid weakening. Track forecast remains difficult as steering currents are expected to collapse, which could mean Darby stalling off the coast.

Edited by Somerset Squall, 25 June 2010 - 17:40 .

[cookie]

Edited by cookie, 25 June 2010 - 18:17 .

[cookie]

again looking very good

[Somerset Squall]

Yup, intensity now up to 105kts, and Darby could well become a cat 4 before shear increases tomorrow. Interesting to note that Darby is the earliest second major hurricane of a season since reliable records began in 1971.

[Somerset Squall]

Darby's peak did not go above 105kts, and now he is being blasted by 30kts of shear. Intensity has fallen to 50kts, and this could be generous. Darby is now trapped in an ill defined steering environment, and will only slowly turn towards the northeast before dissipating in continued high shear, which is probably being caused by the much larger TS Alex to the east. The storm is not much threat to the coast of Mexico.

[cookie]

Quote

FORECAST POSITIONS AND MAX WINDS

INITIAL 27/0900Z 13.5N 103.3W 50 KT
12HR VT 27/1800Z 13.5N 103.4W 40 KT
24HR VT 28/0600Z 13.9N 103.0W 35 KT
36HR VT 28/1800Z 14.2N 102.5W 25 KT
48HR VT 29/0600Z 14.5N 101.9W 25 KT
72HR VT 30/0600Z 14.9N 100.9W 20 KT...POST-TROP/REMNT LOW
96HR VT 01/0600Z...DISSIPATED

$$
FORECASTER ROBERTS/STEWART