|
|
|||||||
Invest 98C located near 21.5N 179.3E at 19/05Z has been moving to the south southwest over the past 12 hours. System shows a tight circulation with an eye present from time to time and is probably a Subtropical Storm. SST is about 26C. Although the system is designated as 98C by NRL (because it originated east of 180 degrees), I can find no text references to the Invest by either CPHC or JTWC. ED |
||||||||
|
|
|||||||
Found the following, somewhat dated, from CPHC: "Issued: Dec 18, 2010 8:00 am HST For the central north Pacific, between 140°W and 180. 1. A gale low located just west of the international dateline about 500 miles south southwest of Midway atoll, which is moving toward the south at less 10 mph, continues to exhibit tropical characteristics as it moves over warmer waters. This system is maintaining a well defined and persistent area of thunderstorms near its center. Forecast models indicate this system will turn back toward the southeast or east later tonight and Sunday morning, which will likely bring it back into the Central Pacific Hurricane Center area of responsibility by late Sunday. There is a high chance, 90 percent, of this system becoming a tropical cyclone during the next 48 hours. " |
||||||||
|
|
|||||||
At 19/15Z, the un-named STS designated as 98C was located over 1,200 miles west of the Hawaiian Islands at 21.2N 179.1E moving to the south. The system is acquiring tropical characteristics and is expected to become a tropical cyclone. The system already has gale force winds and a well defined center with excellent banding structure. CPHC anticipates that the system will begin moving to the southeast and as soon as it crosses east of 180 degrees it will fall under the responsibility of CPHC (and at that time I suspect that it will be named 'Omeka'). Latest from CPHC Honolulu: "Issued: Dec 19, 2010 2:00 am HST For the central north Pacific, between 140°W and 180. 1. A gale low located just west of the international dateline about 525 miles south southwest of Midway atoll, which is moving toward the south at less 10 mph, continues to exhibit tropical characteristics as it moves over warmer waters. This system is maintaining a persistent ring of thunderstorms surrounding its well defined center. Forecast models indicate this system will turn back toward the southeast or east today, which will likely bring it back into the Central Pacific Hurricane Center area of responsibility later today or tonight. There is a high chance, 90 percent, of this system becoming a tropical cyclone during the next 48 hours." |
||||||||
|
|
|||||||
From CPHC: TROPICAL CYCLONE GUIDANCE MESSAGE NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI 0233 UTC MON DEC 20 2010 DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS. PLEASE REFER TO CPHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE AND SUBTROPICAL CYCLONE INFORMATION. CENTRAL PACIFIC OBJECTIVE AIDS FOR DISTURBANCE INVEST (CP982010) 20101220 0000 UTC ...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS... 101220 0000 101220 1200 101221 0000 101221 1200 LAT LON LAT LON LAT LON LAT LON BAMS 20.2N 179.9W 21.6N 177.8W 24.2N 176.7W 27.0N 176.3W BAMD 20.2N 179.9W 21.5N 174.3W 25.5N 171.2W 29.2N 170.3W BAMM 20.2N 179.9W 21.5N 175.8W 24.7N 173.3W 28.0N 172.4W SHIP 45KTS 53KTS 60KTS 63KTS DSHP 45KTS 53KTS 60KTS 63KTS ...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS... 101222 0000 101223 0000 101224 0000 101225 0000 LAT LON LAT LON LAT LON LAT LON BAMS 30.3N 176.0W 36.0N 175.9W 42.8N 177.9E 48.6N 172.4E BAMD 33.1N 169.1W 35.7N 157.0W 37.1N 132.5W 49.4N 121.4W BAMM 31.7N 171.7W 36.4N 166.5W 31.3N 160.4W 26.4N 157.1W SHIP 64KTS 43KTS 0KTS 0KTS DSHP 64KTS 43KTS 0KTS 0KTS ...INITIAL CONDITIONS... LATCUR = 20.2N LONCUR = 179.9W DIRCUR = 100DEG SPDCUR = 10KT LATM12 = 21.0N LONM12 = 179.1W DIRM12 = 180DEG SPDM12 = 6KT LATM24 = 22.2N LONM24 = 179.4W WNDCUR = 45KT RMAXWD = 25NM WNDM12 = 30KT CENPRS = 997MB OUTPRS = 1004MB OUTRAD = 145NM SDEPTH = D RD34NE = 45NM RD34SE = 45NM RD34SW = 45NM RD34NW = 45NM Note that the 12 and 24 hour prior Longitudes should read 'E' rather than 'W'. JMA did designate the system as TC ONE earlier on Sunday. System is moving to the east northeast and westerly shear is evident. CPHC will probably start advisories at either 20/06Z or 20/09Z. ED |
||||||||
|
|
|||||||
From CPHC: "Tropical Storm OMEKA Advisory Number 1 Issued at 1100 PM HST SUN DEC 19 2010 SUMMARY OF 1100 PM HST...0900 UTC...INFORMATION ----------------------------------------------- Location: 20.9N 178.2W ABOUT 505 MI S OF MIDWAY ISLAND ABOUT 1210 MI W OF LIHUE HAWAII Maximum sustained winds: 50 MPH Present movement: NE or 50 degrees AT 14 MPH Minimum central pressure: 997 MB...29.44 INCHES" TROPICAL STORM OMEKA DISCUSSION NUMBER 1 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP012010 1033 PM HST SUN DEC 19 2010 SATELLITE IMAGERY INDICATES THAT TROPICAL STORM OMEKA...WHICH MOVED EAST OF THE INTERNATIONAL DATELINE DURING THE LAST SIX HOURS...HAS ASSUMED A SHEARED PATTERN WITH A WELL DEFINED LOW LEVEL CIRCULATION CENTER WEST OF A DENSE THUNDERSTORM CLUSTER. THE TROPICAL STORM INTENSITY IS BASED ON A DVORAK ESTIMATE OF 3.0 OR 45 KT FROM HFO. PERSISTENT SHEAR FROM THE WEST WILL EVENTUALLY CAUSE THE DEMISE OF OMEKA IN THE NEXT 48 HOURS OR SO. THE 06Z OFFICIAL POSITION IS BASED ON A 0530Z FIX FROM HFO. INITIAL MOTION IS TO THE NORTHEAST AT 14 MPH...AND IS FORECAST TO TURN TO THE NORTH OVER THE NEXT 24 TO 48 HOURS. THE TRACK MOVES OMEKA EAST OF MIDWAY ISLAND AS A TROPICAL DEPRESSION. THE OFFICIAL TRACK IS IN THE MIDDLE OF A LIMITED NUMBER OF OBJECTIVE AIDES. FORECAST POSITIONS AND MAX WINDS INITIAL 20/0900Z 20.9N 178.2W 45 KT 12HR VT 20/1800Z 22.0N 176.5W 40 KT 24HR VT 21/0600Z 24.9N 175.0W 35 KT 36HR VT 21/1800Z 28.7N 174.4W 30 KT 48HR VT 22/0600Z 33.4N 174.8W 20 KT...POST-TROP/REMNT LOW |
||||||||
|
|
|||||||
TS Okema has become an extratropical system and CPHC has issued the last advisory for the system. The gale center will move north northeast and pass well to the east of Midway Island today. In Hawaii these winter systems usually have subtropical characteristics and are known as 'Kona' lows and can produce wind gusts on the Islands in excess of 80mph. For additional reading see Kona Low . ED |