CoconutCandy
(User)
Fri Jul 20 2007 07:39 AM
Attachment
Cosme Attempting Regeneration

Well, things are getting more interesting by the hour!

Despite still being over cooler SST's and in spite of the persistent moderate easterly shear, Cosme certainly appears to be attempting regeneration back to a tropical storm. And it's now quite likely she may just pull it off sooner or later in the next day or two.

Judging from the appearance of satellite imagery loops over the past few hours, I'd say she's well on her way to doing just that. After waning somewhat overnight, since this afternoon, Hawaii time, convective trends are again on the upswing.

http://weather.hawaii.edu/satellite/sata...amp;overlay=off

From the CPHC's latest (5pm HST) forecast discussion, highly paraphrased:

"THE INTENSITY FORECAST REMAINS LESS THAN CERTAIN. CONVECTION CONTINUES TO FLAIR UP MAINLY WEST OF THE CENTER. COSME REMAINS OVER FAIRLY COOL WATER OF ABOUT 77 DEGREES FAHRENHEIT.

THE LATEST GFDL AND SHIP FORECASTS CONTINUE TO INDICATE SOME SLIGHT STRENGTHENING BACK TO A MINIMAL TROPICAL STORM WITH SHIPS INDICATING 40 KT AT 48 HOURS AND 45 KT OUT AT 120 HOURS. THE HWRF GUIDANCE BRINGS COSME UP TO 37 KT IN 36 HOURS AND 47 KT OUT AT 48 HOURS.

THE UW-CIMSS EXPERIMENTAL VERTICAL SHEAR TC INTENSITY TREND ESTIMATES SHOW LESS SHEAR OVER THE SYSTEM THAN 6 HOURS AGO AND INDICATED FAVORABLE CONDITIONS FOR POSSIBLE INTENSIFICATION THROUGH 18 HOURS ... WE EXPECT COSME TO BE MOVING OVER WARMER WATER BUT ALSO INTO AN AREA WITH STRONGER VERTICAL SHEAR FROM A UPPER TROUGH NORTHWEST OF THE MAIN HAWAIIAN ISLANDS.

IT IS HARD TO SAY WHICH OF THESE FACTORS WILL PREVAIL. CONFIDENCE IN THE INTENSITY FORECAST REMAINS LOW."

And since this advisory, convection has continued to increase as the shear relaxes just a tad, per UW-CIMSS, and not just in the western semi-circle, but now is beginning to pop up in the NE quad, as well, though not especially deep quite yet.

Please view the provided attachment (above) for a good Microwave Imager Overpass, depicting the convection just to the west of the LLC, and a nice, well defined rainband forming in the NW quadrant and deep convection beginning to build in the NE quad, which seems to suggest that the shear is starting to relax a little, as just mentioned.

And the overall appearance of the depression steadily continues to improve, as well. Earlier this afternoon, it appeared somewhat elongated SW to NE, but now appears more symetrical and an extensive mid-level cloud shield is developing over the system, as well.

Shifting gears to a more local perspective:

NWS forecast office in Honolulu has recently issued a Flash Flood Watch for the Big Island of Hawaii, as well as a Wind Advisory for the upper slopes and summits of the tall mountains on the Big Island and Maui. Please view:

http://www.prh.noaa.gov/hnl/

... for color coded links to these special weather statements, (may include other statements by the time you read this).

It appears that the Big Island may pick up as much as 5 to 10 inches, possibly leading to localized flash flooding in some areas.

And the current wind advisory may need to be upgraded to a High Wind Warning for the higher slopes of the volcanoes, especially if Cosme does strengthen back to tropical storm force as she passes near the Islands.

For a nice close-up short IR loop of a Hawaii centered image please view:

http://www.prh.noaa.gov/hnl/satellite/Hawaii_IR_loop.gif

... as you see Cosme entering the theatre stage right.

Finally, (whew!) a snip from the latest NWS synoptic discussion (seperate from the CPHC's advisory/discussion) paints a very wet picture for the weekend:

"THE STRONG POSSIBILITY OF SIGNIFICANT RAINFALL FOR MAINLY WINDWARD PARTS OF THE THE BIG ISLAND HAS NECESSITATED ISSUANCE OF A FLASH FLOOD WATCH FOR THE BIG ISLAND TO COVER THE FRIDAY NIGHT AND SATURDAY TIME PERIOD. THE OTHER ISLANDS WILL RECEIVE LESS RAINFALL WITH A CHANCE OF SOME HEAVY SHOWERS.

PRESENTLY THE AMOUNT OF MOISTURE ACCOMPANYING THE TROPICAL SYSTEM APPEARS TO COVER A RELATIVELY LARGE AREA NORTH OF THE CENTER."

For a complete read of Hawaii's synoptic discussion, link to:

http://www.prh.noaa.gov/data/HFO/AFDHFO

... which may be different and further expanded by the time you read this.

So, all in all, it's quite likely that Cosme may pull a few more tricks out of her magicians' hat before all is said and done. And the media is likely to pick up on all this soon, too, like the Weather Channel and CNN, etc. and may even send reporters out to the Islands to do some live broadcasts, especially if Cosme *does* regenerate into a tropical storm.

The best part is that the Big Island, and the other Islands to a lesser extent, may get the good soaking it needs, ala Barrys' good quenching of Florida!

More later. Keep those replies coming!

Warm Aloha from Honolulu - Norm



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