Average Rainfall Last 30 Days
For Latest Update on Typhoon Melor, former Typhoon Parma and new tropical cyclone, CLICK HERE
Typhoon Melor Forecast Track
The Forecast Track of Typhoon Melor (see JTWC discussion below) is behaving itself with regard to the the intensity, direction and forward speed. While the report from USA Today claims winds of 100 mph, the storm has actually weakend with 65 kt sustained winds (80 mph) with gusts perhaps as high as 80 kts( 95 to 100 mph). The media always seems to take the outlying wind gusts as the measuring point since it sounds better. It is but a shadow of its former self when it was a super typhoon with 145 kt winds (165mph) and gusts pushing toward 160 kts (185mph). All along, it had been forecast to make the turn in the northwest Philippines Sea and swing toward Japan and while doing so, weaken rather rapidly as it encounters strong upper level wind shear and moves into a baroclinic zone (a frontal boundary) and become extra tropical as it accelerates to the northeast.
Click Image for Color IR WPac Loop
Now, apparently officials are expecting rain totals of up to 20 inches, which is relatively benign but still a little more elevated than one might expect from a fast moving storm. I suspect that the mountains of Honshu are expected to enhance the rain totals and that is the reason for that expectation. There is some question as to whether or not the storm will run right over Tokyo, to the west of Tokyo or just to the east of Godzilla’s favorite stomping ground but the official forecast has been consistent with it running just west of the largest city in Japan. There will be gusty wind and high seas with elevated sea levels in Tokyo Bay, but I suspect the rain deluge will be the biggest issue in mountainous regions.
Melor Vertical Temp Anomaly 21Z 10.07.09
Now, what makes a tropical cyclone different from a typical storm. Both are low pressure but a typical storm is one that has a cold core. Most of the time you expect to have colder air aloft and convection is supported by warmer air below along with certain wind dynamics. A characteristic that makes a tropical cyclone distinctive from a normal area of low pressure is that the core is warm. It’s called a warm core low. A good strong tropical cyclone will have much warmer air aloft than at the surface at the center. The storm feeds off of warm ocean waters and in order for one to get going, you need to have water temperatures of at least 26.5 C (80 F) water temperatures.
Parma Vertical Temp Anomaly 2048Z 10.07.09
In the case of Parma, (see JTWC discussion below) it was sitting over the same water for some time while it was northwest of the Philippines. It was washing away the warm water on the surface and colder water was coming to the surface and so it began to kill itself. In the case of Typhoon Melor, its been moving right along and so has maintained its tropical characteristics. Even now as its running into a hostile environment, it still has warmer temperatures aloft as seen to the upper right. To the left is the weaker Parma that still has a decent circulation but its warm core is not as distinct as the stronger Melor. But, it is still a warm core low so Parma is still a tropical cyclone. However, it has been downgraded at this time to a tropical depression because the winds have backed off so much.
Parma Forecast Track
Now, Parma has been meandering across the northern part of the Philippines and actually may be just off the northeastern coast in the Philippines Sea. For all intents and purposes, its been stationary but officially its been drifting northeast. The biggest signifincance with this is that with the center of circulation over the water, it may be able to at least maintain its weak stature if not actually increase a bit in intensity. As it is, Parma’s rain over the Philippines on Wednesday was sparse enough for clean up efforts to remain robust in Manila, where it is said that the garbage and debris blocking the streets is such that it may take two months to get things back to something close to normal. The track of Parma will not help for the next couple of days. A ridge of high pressure is building to the northeast in China and will move in to the north behind Melor. As it does, Parma will begin a drift back toward the west. As of this report, Parma was starting to show signs of convenction increasing as its over the water and so, as Parma drifts back across the Philippines, it will bring more rain.
30 Day Avg Daily Rainfall anomaly
Probably not as much as they had with the initial landfall but anything they get is too much. Take a look at the top of the page at the average rainfall in the region over the past 30 days. Thats an average of over 20 mm a day or about .80 inches. Now, much of that fell with Ketsana when they got their monthly total in Manila in about 12 hours. The rainfall anomoly is to the left and so it shows just how much more rain the northern Philippines has received in the last 30 days than the average. Its about 15mm a day more than average or about .60 inches per day. So, any additional rain will be no help. The storm will acclerate to the west and head to China. As it moves across the South China Sea with the ridge to the north building, it will get into an environment that will be favorable for re-development. The good news is that it will probably run into land before it can become too strong again (back to tropical storm status) but its certain to bring heavy rains to the landfall location, particularly to the right of where the eye crosses the land.
DEPRESSION PARMA Discussion warning #40
WDPN33 PGTW 071500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (PARMA)//
WARNING NR 40//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TROPICAL STORM (TS) 19W (PARMA), LOCATED APPROXIMATELY 225 NM
NORTH-NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTH-
NORTHEASTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. RECENT ANIMATED
INFRARED IMAGERY SHOWS THAT TS PARMA HAS CROSSED NORTHERN LUZON AND
IS NOW BACK OVER WATER IN THE PHILIPPINE SEA. DEEP CONVECTION
WANED AS THE SYSTEM TRACKED OVER LAND, THOUGH IT APPEARS THAT SOME
CONVECTION HAS RECENTLY STARTED TO REDEVELOP OVER THE LOW LEVEL
CIRCULATION CENTER (LLCC). PARMA CONTINUES TO SUSTAIN IN A VERY WEAK
STEERING ENVIRONMENT AS IT SITS IN A COL REGION OF THE SUBTROPICAL
RIDGE. THE CURRENT POSITION IS BASED ON CONSISTENT POSITION FIXES BY
RJTD AND THE CURRENT INTENSITY IS BASED WITH LOW CONFIDENCE ON
DVORAK ESTIMATES FROM PGTD AND RJTD.
3. FORECAST REASONING
A. THE FORECAST REASONING HAS NOT SIGNIFICANTLY CHANGED SINCE THE
LAST PROGNOSTIC REASONING BULLETIN.
B. TS PARMA WILL CONTINUE TO DRIFT GENERALLY WESTWARD IN A VERY
WEAK STEERING ENVIRONMENT OVER THE NEXT 48 HOURS. PARMA IS ALSO
EXPECTED TO WEAKEN AS IT TRACKS BACK OVER NORTHERN LUZON.
C. BEYOND TAU 48, TS PARMA WILL CONTINUE TRACKING WESTWARD UNDER
THE INFLUENCE OF THE SUBTROPICAL STEERING RIDGE ANCHORED OVER CHINA,
WHICH IS FORECAST TO GRADUALLY BUILD EASTWARD. AS THE STEERING
INFLUENCE BECOMES MORE DEFINED BY TAU 72, PARMA WILL START TO PICK UP TRACK
SPEED THROUGH THE SOUTH CHINA SEA AND RE-INTENSIFY UNDER FAVORABLE
ENVIRONMENTAL CONDITIONS CHARACTERIZED BY GOOD EQUATORWARD OUTFLOW
SOUTH OF THE SUBTROPICAL RIDGE AXIS. THE NUMERICAL MODEL AIDS
GENERALLY AGREE WITH AN EVENTUAL TURN TO THE WEST, THOUGH THE TIMING
AND DEGREE OF THIS TURN VARIES WIDELY. THIS FORECAST LEANS ON THE
EUROPEAN SOLUTIONS PROVIDED BY THE UKMO AND ECMWF.//
TYPHOOH MELOR Discussion warning 34
WDPN34 PGTW 071500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 20W (MELOR) WARNING NR 34//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TYPHOON (TY) 20W (MELOR), LOCATED APPROXIMATELY 350 NM SOUTH-
WEST OF TOKYO, JAPAN, HAS TRACKED NORTHEASTWARD AT 25 KNOTS OVER THE
PAST SIX HOURS. TY MELOR IS POLEWARD OF THE SUBTROPICAL RIDGE AXIS
AND IS ACCELERATING NORTHEASTWARD INTO THE MID-LATITUDES. RECENT
ANIMATED INFRARED IMAGERY SHOWS THAT THE DEEP CONVECTION HAS SHIFTED
TO THE NORTH OF THE LOW LEVEL CIRCULATION CENTER (LLCC) AND WATER
VAPOR IMAGERY INDICATES THAT THE DEEP CONVECTION IS BEING SHEARED TO
THE NORTHEAST BY THE STRONG MID-LATITUDE WESTERLIES. THE 071002Z
37GHZ SSMIS MICROWAVE IMAGE REVEALS EROSION IN THE SOUTHEAST
QUADRANT OF THE EYE WALL AS WELL AS THE APPEARANCE OF DRY AIR
ENTRAINMENT. THE CURRENT POSITION IS IN LINE WITH THE LAST SIX RJTD
RADAR FIXES AND THE CURRENT INTENSITY IS A ROUGH AVERAGE OF THE
DVORAK ESTIMATES FROM RJTD, PGTW AND KNES.
3. FORECAST REASONING
A. THE FORECAST PHILOSOPHY HAS NOT SIGNIFICANTLY CHANGED SINCE
THE PREVIOUS PROGNOSTIC REASONING BULLETIN.
B. TY MELOR WILL CONTINUE TO ENCOUNTER UNFAVORABLE VERTICAL WIND
SHEAR (GREATER THAN 50 KNOTS) ASSOCIATED WITH THE MID-LATITUDE BARO-
CLINIC ZONE AND IS EXPECTED TO MAKE LANDFALL IN THE NEXT 08 TO 10
HOURS AS MINIMAL TYPHOON. AFTER MAKING LANDFALL, TY MELOR WILL
TRANSIT ACROSS HONSHU WHILE UNDERGOING EXTRATROPICAL TRANSITION. BY
TAU 24 HOUR, MELOR SHOULD ATTAIN FULL BAROCLINICITY AND PASS EAST
OF MISAWA, JAPAN, AS A STRONG, JET-SUPPORTED BAROCLINIC SYSTEM. THE
MODEL AIDS ARE IN TIGHT AGREEMENT WITH A LANDFALL SCENARIO WEST
OF TOKYO, JAPAN. HOWEVER, THE UKMO TRACKER, EGGR, IS THE EASTERN
OUTLIER AND TRACKS THE SYSTEM ROUGHLY 20 NM WEST OF TOKYO, JAPAN.
THIS FORECAST DOES NOT TAKE MELOR AS FAR EAST AS THE EGRR TRACKER,
THOUGH IT DOES TRACK EAST OF THE JTWC CONSENSUS.//
