Tropical Storm Ignacio

[Somerset Squall]

The twelfth tropical depression of the East Pacific season has formed, out of invest 93E. Initial intensity is at 30kts. 12E is expected generally west northwestwards in repsonse to ridging over the western USA. 12E will then veer northwestwards as it rounds the periphery of the ridge. This motion will eventually take 12E over colder waters. Until then, 12E has ample opportunity to strengthen, for about the next 48hrs. 12E has a moderate chance of becoming a hurricane, though the official forecast shows peaking at strong tropical storm. Remember Guillermo? I'm not saying the same will happen, but NHC underestimated intensity then.

[Cookie]

They keeping on coming these east pacific systems

[Somerset Squall]

Indeed, thats 6 this month, with a potential 7th if 93L moes into the East Pacific. 3 of those storms moved into the Central Pacific. Total number of storms moving in/forming in the Central Pacific is now 5, which is above average already.

12E looks close to storm strength. We may have Ignacio named overnight IMO.

[Somerset Squall]

12E was indeed upgraded to tropical storm Ignacio overnight, and since then, Ignacio has continued to strengthen. Intensity has increased to 45kts, and Ignacio is showing a much better organised convective pattern than yesterday. Banding features have become more prominent, and the LLC has tightened up. Ignacio has another 24hrs to intensify before cooler waters begin to weaken the storm. Ignacio is not likely to become a hurricane before this occurs.

[Cookie]

thanks for the updates

TROPICAL STORM IGNACIO DISCUSSION NUMBER 5

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP122009

200 PM PDT TUE AUG 25 2009

VISIBLE SATELLITE PICTURES SUGGEST THAT THE CLOUD PATTERN OF IGNACIO

HAS BECOME BETTER ORGANIZED...WITH SOME HINT OF THE BEGINNING STAGE

OF A CENTRAL DENSE OVERCAST FORMING. EVEN THOUGH THE NORTHWEST

SEMICIRCLE IS VOID OF DEEP CONVECTIVE CLOUDS...A WELL-DEFINED BAND

IS OBSERVED OVER THE SOUTHEAST SEMICIRCLE. DVORAK T-NUMBERS REMAIN

AT T3.0 FROM BOTH TAFB AND SAB AND THE OFFICIAL INTENSITY IS

MAINTAINED AT 45 KT. A 1417 UTC QUIKSCAT PASS REVEALED A FEW

UNCONTAMINATED 45-50 KT WIND VECTORS...WHICH AGREE WELL WITH THE

CURRENT INTENSITY ESTIMATE. EVEN THOUGH THE SHEAR SHOULD REMAIN

RELATIVELY LIGHT...THE WINDOW OF OPPORTUNITY FOR STRENGTHENING WILL

BE CLOSING SOON SINCE THE CYCLONE SHOULD REMAIN OVER 26.5C WATERS

FOR LESS THAN 12 HOURS. THEREAFTER...PROGRESSIVELY COOLER WATERS

ALONG THE FORECAST TRACK SHOULD CAUSE RAPID WEAKENING...AND IGNACIO

IS EXPECTED TO BECOME A REMNANT LOW BY 72 HOURS.

THE EARLIER QUIKSCAT PASS AND RECENT VISIBLE SATELLITE FIXES HAVE

YIELDED FAIRLY HIGH CONFIDENCE ESTIMATES OF THE CENTER LOCATION.

BASED UPON THOSE ESTIMATES...THE INITIAL MOTION IS 300/11. THERE

HAS BEEN LITTLE CHANGE TO THE OFFICIAL FORECAST TRACK. IGNACIO

SHOULD MAINTAIN A NORTHWESTERLY COURSE AS IT MOVES AROUND THE

WESTERN PERIPHERY OF A DEEP-LAYER ANTICYCLONE EXTENDING FROM THE

SOUTHERN UNITED STATES INTO THE EAST PACIFIC TO NEAR 130W. TOWARD

THE END OF THE PERIOD...THE CYCLONE SHOULD ASSUME A MORE WESTERLY

TRACK ONCE IGNACIO WEAKENS AND BECOMES MORE SHALLOW. THE OFFICIAL

TRACK DIFFERS LITTLE FROM THE PREVIOUS ADVISORY AND LIES BETWEEN THE

PREVIOUS FORECAST AND THE MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/2100Z 19.4N 120.3W 45 KT

12HR VT 26/0600Z 20.4N 121.8W 50 KT

24HR VT 26/1800Z 21.9N 123.8W 50 KT

36HR VT 27/0600Z 23.6N 125.7W 45 KT

48HR VT 27/1800Z 25.2N 127.6W 35 KT

72HR VT 28/1800Z 27.0N 130.5W 25 KT...REMNANT LOW

96HR VT 29/1800Z 27.0N 134.0W 20 KT...REMNANT LOW

120HR VT 30/1800Z...DISSIPATED

$$

FORECASTER KIMBERLAIN

[Cookie]

looking better

[Somerset Squall]

Indeed Cookie, Ignacio looked pretty good this morning and I think it was a touch stronger than the estimate of 45kts at that point. However, Ignacio is moving over rapidly cooling waters and into a more stable environment. This has caused a significant loss in convection over the last 6hrs in particular. Intensity is reduced to 40kts, and this is probably because Ignacio still has a strong LLC. Convection wise, this doesn't look like a 40kt tropical storm. Ignacio could degenerate into a remnant low at any time, particularly if convection doesn't make a comeback in that western quadrant.

[Somerset Squall]

Ignacio was declared a remnant low earlier today as the LLC remained convectionless for the previous 12 hours. This was hardly surprising as sea temps were rapidly dropping below 24C. Regeneration is not expected.

[Cookie]

cold waters really took their toll on this