Tropical Storm Cosme

[Andrew92]

Mods/admins, the old thread can be locked as we now have Cosme.

the satellite presentation of the cyclone has continued to improve
today. The once broad circulation has become more consolidated and
the center is embedded under the deep convection. Outer banding
features surround the center...but cloud tops have warmed during the
last couple of hours. 1800 UTC Dvorak classifications were 3.0/45
kt from TAFB and 2.5/35 kt from SAB. In addition....a 1500 UTC
Quikscat pass over the western half of the circulation showed
seemingly reliable 30 kt winds...but was inconclusive about
anything stronger. Based on these data...six-E has been upgraded
to Tropical Storm Cosme with 35 kt winds...leaning toward the lower
Dvorak estimates for now.

The initial motion is estimated at 305/7. The steering mechanism
and track forecast reasoning has changed little from this morning.
Cosme is expected to move northwest and west-northwest toward a
weakness in the ridge for the next day or so...then curve more
toward the west once the ridge builds back in.
Cosme should remain over warm waters and in a relatively low shear
environment for the next day or so...allowing for some strengthening
to occur. Thereafter...gradual weakening is anticipated as Cosme
moves over cooler waters. The official intensity forecast is once
again a consensus of the SHIPS...GFDL...and hwrf guidance.

Forecast positions and Max winds

initial 15/2100z 12.7n 128.0w 35 kt
12hr VT 16/0600z 13.3n 128.9w 45 kt
24hr VT 16/1800z 14.0n 130.3w 45 kt
36hr VT 17/0600z 14.5n 132.3w 45 kt
48hr VT 17/1800z 14.7n 134.3w 40 kt
72hr VT 18/1800z 15.0n 138.5w 40 kt
96hr VT 19/1800z 16.0n 143.0w 35 kt
120hr VT 20/1800z 17.5n 148.0w 30 kt

$$
forecaster Mainelli

[cycloneye]

Locked the TD six thread.The 40+ days drought of named storms is over.

[AnnularCane]

Hey there, Cosme. You did it.

Quite a contrast between the two systems, isn't there?

[windstorm99]

Looks fairly well organized...

[HURAKAN]

[Matt-hurricanewatcher]

Strenthing fast, cimss shows LLC in the center of the CDO. With 3.3t=51 knots. I agree its close to 45-50 knots.

[cycloneye]

Umm,Cosme in my view has a shot to at least a minimal hurricane as it has continued to organize faster than what I expected.

[AnnularCane]

Cosme looks like he's having his back scratched by 5-E.

[HURAKAN]

Cosme looks like he's having his back scratched by 5-E.

TD 5-E doesn't want to move even a muscle because it knows Cosme will eat it up!!!

[HURAKAN]

16/0000 UTC 13.1N 128.4W T3.0/3.0 COSME -- East Pacific Ocean

50 mph says Dvorak.

[CrazyC83]

I think 45 kt right now but strengthening. Maybe 50 kt by the advisory time. It may become the first hurricane of the Western Hemisphere in 2007 though sometime tomorrow...

[HURAKAN]

COSME.45kts.1000mb

[Chacor]

Here's the 00Z model runs, SHIPS takes it to Hurricane Cosme:

612
WHXX01 KMIA 160116
CHGE77
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0116 UTC MON JUL 16 2007

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

EAST PACIFIC OBJECTIVE AIDS FOR

TROPICAL CYCLONE COSME (EP062007) 20070716 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
070716 0000 070716 1200 070717 0000 070717 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 13.0N 128.4W 14.0N 129.8W 15.2N 131.4W 15.9N 133.3W
BAMD 13.0N 128.4W 13.9N 130.2W 14.6N 132.1W 14.7N 134.1W
BAMM 13.0N 128.4W 13.9N 129.8W 14.9N 131.2W 15.6N 133.0W
LBAR 13.0N 128.4W 13.7N 129.9W 14.4N 131.9W 14.7N 134.2W
SHIP 45KTS 58KTS 67KTS 68KTS
DSHP 45KTS 58KTS 67KTS 68KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
070718 0000 070719 0000 070720 0000 070721 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 16.7N 135.6W 18.1N 140.4W 20.0N 145.2W 20.6N 150.2W
BAMD 14.5N 136.3W 14.6N 140.8W 16.4N 144.8W 17.8N 147.8W
BAMM 16.4N 135.2W 17.6N 140.5W 19.2N 145.7W 19.8N 150.4W
LBAR 14.9N 136.9W 15.1N 142.8W 16.4N 147.8W 18.8N 150.2W
SHIP 63KTS 48KTS 40KTS 36KTS
DSHP 63KTS 48KTS 40KTS 36KTS

...INITIAL CONDITIONS...
LATCUR = 13.0N LONCUR = 128.4W DIRCUR = 305DEG SPDCUR = 7KT
LATM12 = 12.1N LONM12 = 127.2W DIRM12 = 304DEG SPDM12 = 5KT
LATM24 = 11.6N LONM24 = 126.6W
WNDCUR = 45KT RMAXWD = 30NM WNDM12 = 30KT
CENPRS = 1000MB OUTPRS = 1011MB OUTRAD = 175NM SDEPTH = D
RD34NE = 60NM RD34SE = 60NM RD34SW = 30NM RD34NW = 45NM

$$
NNNN

[Cyclenall]

I haven't been watching any basin for days now but when I found this and then the SAT image of Cosme, I was floored!! That looks like some good old Epac RI. It's like a small hurricane without an eye or eyewall. I'd peg that at 50-55 knots just because of how well organized it is. This is a nice surprise after such quiet TD's forming!

EDIT: You can tell this tropical cyclone means business when you see how fast the spinning of the center is through the loops. No wonder the SHIPS RI Index was so high at the start. I don't know a whole lot about this TC so far so I can't comment on much else. The NHC thinks if trends continue, Cosme could become a hurricane before weakening. I agree.

[cycloneye]

WTPZ41 KNHC 160231
TCDEP1
TROPICAL STORM COSME DISCUSSION NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062007
800 PM PDT SUN JUL 15 2007

COSME IS GETTING BETTER ORGANIZED. AN AMSR-E OVERPASS AT 2200 UTC
SUGGESTED THE DEVELOPMENT OF A TIGHTER INNER CORE...AND SUBSEQUENT
CONVENTIONAL IMAGERY SHOWS A SIGNIFICANT INCREASE IN CONVECTION
NEAR THE CENTER. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB
ARE NOW 45 KT...AND THAT IS THE INITIAL INTENSITY.

THE INITIAL MOTION REMAINS 305/7. LARGE-SCALE MODEL ANALYSES SHOW A
WEAKNESS IN THE MID/UPPER-LEVEL SUBTROPICAL RIDGE NORTH OF
COSME...WITH SATELLITE IMAGERY SHOWING A WELL-DEFINED LOW-LEVEL
RIDGE NORTH OF THE STORM. THIS PATTERN SHOULD STEER COSME
GENERALLY WEST-NORTHWESTWARD FOR 24 HR OR SO...FOLLOWED BY A MORE
WESTWARD MOTION AS THE MID/UPPER-LEVEL RIDGE STRENGTHENS SOMEWHAT.
WHILE ALL TRACK GUIDANCE AGREES WITH THIS GENERAL SCENARIO...THE
UKMET...ECMWF...AND BAM MODELS CALL FOR MORE NORTHWARD MOTION IN
THE FIRST 24 HR BEFORE THE WESTWARD TURN. THE GFS...GFDL...HWRF...
AND CONSENSUS MODELS CALL FOR LESS NORTHWARD MOVEMENT BEFORE THE
TURN...AND THE NEW FORECAST TRACK FOLLOWS THESE MODELS. ALL THE
GUIDANCE CALLS FOR A FASTER MOTION AFTER 36 HR THAN THE PREVIOUS
RUNS...SO THE FORECAST FORWARD SPEED HAS BEEN INCREASED SOMEWHAT.
IT SHOULD BE NOTED THAT COSME IS EMBEDDED IN A LARGE CYCLONIC GYRE
THAT INCLUDES THE REMAINS OF TROPICAL DEPRESSION 5-E...AND THIS MAY
PRODUCE SOME TRACK WOBBLES DURING THE FIRST 24-36 HR.

COSME IS IN AN ENVIRONMENT OF LIGHT SOUTHEASTERLY VERTICAL SHEAR...
AND THE CYCLONE SHOULD REMAIN IN A FAVORABLE SHEAR ENVIRONMENT FOR
AT LEAST THE NEXT FOUR DAYS. THUS...THE INTENSITY WILL BE
CONTROLLED MAINLY BY THE SEA SURFACE TEMPERATURES. SST ANALYSES
INDICATE THAT THE STORM IS OVER 27C TEMPERATURES...WHICH SHOULD
COOL ALONG THE FORECAST TRACK AFTER 12-24 HR. THIS SHOULD ALLOW
COSME SOME ADDITIONAL STRENGTHENING BEFORE GRADUAL WEAKENING BEGINS
IN 36 HR OR SO. SHIPS FORECAST COSME TO BECOME A HURRICANE...WHILE
THE GFDL AND HWRF DO NOT. THE INTENSITY FORECAST HAS BEEN
INCREASED...NOW CALLING FOR COSME TO PEAK AT 60 KT IN 24 HR AS A
COMPROMISE BETWEEN SHIPS AND THE GFDL/HWRF. IF THE CURRENT
CONVECTIVE TRENDS CONTINUE...THERE IS A CHANCE COSME COULD BECOME A
HURRICANE BEFORE WEAKENING BEGINS.

THE FORECAST WIND RADII HAVE BEEN INCREASED BASED ON THE INCREASED
FORECAST INTENSITY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 16/0300Z 13.3N 128.8W 45 KT
12HR VT 16/1200Z 13.8N 129.9W 55 KT
24HR VT 17/0000Z 14.5N 131.6W 60 KT
36HR VT 17/1200Z 14.8N 133.4W 60 KT
48HR VT 18/0000Z 15.0N 135.5W 55 KT
72HR VT 19/0000Z 15.5N 140.5W 50 KT
96HR VT 20/0000Z 16.5N 146.0W 40 KT
120HR VT 21/0000Z 17.5N 151.0W 30 KT

$$
FORECASTER BEVEN

[Chacor]

000
WTPZ21 KNHC 160847
TCMEP1
TROPICAL STORM COSME FORECAST/ADVISORY NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062007
0900 UTC MON JUL 16 2007

TROPICAL STORM CENTER LOCATED NEAR 13.8N 129.5W AT 16/0900Z
POSITION ACCURATE WITHIN 20 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 9 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 994 MB
MAX SUSTAINED WINDS 55 KT WITH GUSTS TO 65 KT.
50 KT....... 20NE 20SE 0SW 0NW.
34 KT....... 70NE 70SE 35SW 50NW.
12 FT SEAS.. 90NE 90SE 35SW 60NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 13.8N 129.5W AT 16/0900Z
AT 16/0600Z CENTER WAS LOCATED NEAR 13.6N 129.1W

FORECAST VALID 16/1800Z 14.4N 130.7W
MAX WIND 60 KT...GUSTS 75 KT.
50 KT... 25NE 25SE 15SW 15NW.
34 KT... 75NE 75SE 50SW 75NW.

FORECAST VALID 17/0600Z 14.9N 132.5W
MAX WIND 65 KT...GUSTS 80 KT.
64 KT... 15NE 15SE 0SW 0NW.
50 KT... 30NE 30SE 20SW 30NW.
34 KT... 90NE 75SE 60SW 75NW.

FORECAST VALID 17/1800Z 15.2N 134.4W
MAX WIND 65 KT...GUSTS 80 KT.
64 KT... 15NE 15SE 0SW 0NW.
50 KT... 30NE 30SE 20SW 30NW.
34 KT... 90NE 75SE 60SW 75NW.

FORECAST VALID 18/0600Z 15.5N 136.7W
MAX WIND 60 KT...GUSTS 75 KT.
50 KT... 30NE 25SE 20SW 30NW.
34 KT... 80NE 60SE 60SW 80NW.

FORECAST VALID 19/0600Z 16.2N 141.5W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 30NE 0SE 0SW 30NW.
34 KT... 75NE 50SE 50SW 75NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 200 NM
ON DAY 4 AND 225 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 20/0600Z 17.0N 146.5W
MAX WIND 40 KT...GUSTS 50 KT.

OUTLOOK VALID 21/0600Z 17.5N 151.5W
MAX WIND 30 KT...GUSTS 40 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 13.8N 129.5W

NEXT ADVISORY AT 16/1500Z

$$
FORECASTER BROWN

[Chacor]

956
WTPZ41 KNHC 160854
TCDEP1
TROPICAL STORM COSME DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062007
200 AM PDT MON JUL 16 2007

COSME HAS CONTINUED TO STRENGTHEN EARLY THIS MORNING. MICROWAVE
OVERPASSES DURING THE PAST SEVERAL HOURS SHOW THAT THE CYCLONE HAS
EXCELLENT BANDING FEATURES AND THE BEGINNING OF AN EYE. DVORAK
INTENSITY ESTIMATES FROM TAFB AND SAB HAVE INCREASED TO 55 KT AND
THAT WILL BE THE INITIAL INTENSITY.

THE INITIAL MOTION IS 305/9. COSME HAS BEEN MOVING NORTHWESTWARD
TOWARD A WEAKNESS IN THE MID- TO UPPER-LEVEL RIDGE NORTH OF THE
CYCLONE. HOWEVER...GLOBAL MODELS SUGGEST THAT THE RIDGE WILL
STRENGTHEN DURING THE NEXT COUPLE OF DAYS...TURNING COSME MORE
WESTWARD. NEARLY ALL OF THE AVAILABLE TRACK GUIDANCE AGREES WITH
THIS SCENARIO...EXCEPT FOR THE NOGAPS WHICH KEEPS THE CYCLONE
MOVING NORTHWESTWARD. THE OFFICIAL TRACK FOLLOWS THE GFDL...
HWRF...GFS AND THE SUPERENSEMBLE CLOSELY AND INDICATES THAT COSME
WILL TURN MORE WESTWARD WITHIN 12-24 HOURS. THE OFFICIAL TRACK IS
CLOSE TO THE PREVIOUS ADVISORY...AND IS BETWEEN THE FASTER GFDL AND
SLOWER GFS.

SINCE COSME IS FORECAST TO REMAIN IN A LOW SHEAR ENVIRONMENT FOR THE
NEXT SEVERAL DAYS THE MAIN FACTOR CONTROLLING INTENSITY WILL BE
SEA SURFACE TEMPERATURES. COSME IS CURRENTLY OVER SSTS NEAR 27C
WHICH SHOULD ALLOW FOR SOME ADDITIONAL STRENGTHENING BEFORE SSTS
GRADUALLY COOL. THE SHIPS MODEL BRINGS COSME TO HURRICANE STRENGTH
WHILE THE GFDL AND HWRF PEAK THE INTENSITY SLIGHTLY LOWER. GIVEN
THE CURRENT STRENGTHENING TREND...THE INTENSITY FORECAST WILL
FOLLOW THE SHIPS MODEL CLOSELY AND PREDICT A HURRICANE WITHIN 24
HOURS. THEREAFTER...THE FORECAST INDICATES SLOW WEAKENING. LATE
IN THE FORECAST PERIOD...SHEAR IS EXPECTED TO INCREASE AND AT THAT
TIME THE INTENSITY FORECAST IS A LITTLE LOWER THAN MOST OF THE
AVAILABLE GUIDANCE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 16/0900Z 13.8N 129.5W 55 KT
12HR VT 16/1800Z 14.4N 130.7W 60 KT
24HR VT 17/0600Z 14.9N 132.5W 65 KT
36HR VT 17/1800Z 15.2N 134.4W 65 KT
48HR VT 18/0600Z 15.5N 136.7W 60 KT
72HR VT 19/0600Z 16.2N 141.5W 50 KT
96HR VT 20/0600Z 17.0N 146.5W 40 KT
120HR VT 21/0600Z 17.5N 151.5W 30 KT

$$
FORECASTER BROWN

[Chacor]

Hawaii better watch this one.

[Aquawind]

Wow.. Cosme did come together fast!

[HURAKAN]

16/1200 UTC 13.9N 129.9W T3.5/3.5 COSME -- East Pacific Ocean

Dvorak says no cane yet.