Public advisory[]
TROPICAL STORM LINFA PUBLIC ADVISORY NUMBER 11
WIKI-HURRICANES FORECASTING CENTER
6:00 AM JST SUN JUL 05 2015
...LINFA TRACKING ALONG THE SHORE OF LUZON...
SUMMARY OF 6:00 AM JST...21:00 UTC...INFORMATION
-------------------------------------------------------------------
LOCATION...17.6N 122.1E
CENTER POSITION CONFIDENCE: HIGH
ABOUT 220 MI...355 KM NNE OF MANILA, PHILIPPINES
MAXIMUM SUSTAINED WINDS...55 KT...65 MPH...100 KM/H
MINIMUM BAROMETRIC PRESSURE...990 MB...29.24 INCHES
PRESENT MOVEMENT...NW AT 5 KT...6 MPH...10 KM/H
DISCUSSION AND 48-HOUR OUTLOOK
---------------------------------------------
At 6:00 am JST, the center of Tropical Storm Linfa was situated near 17.6N 122.1E, or about 220 miles (355 km) north-northeast of Manila, Philippines. Maximum sustained winds were 55 knots (65 mph, 100 km/h), with higher gusts. The minimum barometric pressure was 990 millibars (hPa; 29.24 inHg), and the cyclone was tracking northwest at 5 knots (6 mph, 10 km/h). Interaction with Luzon is expected to deter any intensification over the subsequent 24 hours, but some intensification is possible thereafter the cyclone emerges over water.
NEXT ADVISORY
-------------------
Next complete advisory at 12:00 pm JST.
$$
Forecaster TAWX14
Discussion[]
TROPICAL STORM LINFA DISCUSSION NUMBER 11
WIKI-HURRICANES FORECASTING CENTER
6:00 AM JST SUN JUL 05 2015
Tropical Storm Linfa made landfall around 20z southeast of Tuguegarao, Luzon. Radar out of Appari and a series of microwave passes about an hour previous indicated that the cyclone had developed a closed eyewall, supporting a landfall intensity of approximately 60kt. Since that time, although Linfa remains well organized, the extent of deep convection has lessened, and the initial intensity has been edged down to 55kt.
Linfa is tracking slowly northwestward this evening. A turn in the more northerly direction is expected over the subsequent 24 hours as the cyclone approaches a weakness in the subtropical ridge. By day 3, the track forecast becomes more complicated as what is expected to be a very powerful Chan-hom approaches and low- to mid-level flow accelerates south of the cyclone. Some models, such as the NAVGEM, show Linfa becoming a shallow cyclone that is ultimately steered by that low-level flow into the South China Sea. Other models, such as the ECMWF and HWRF, show a turn toward the north-northwest across Taiwan toward a mid- to upper-level disturbance across northeastern China in the short to medium term. However, by the end of the period, even those two models disagree, with the ECMWF forecasting a dive toward the southwest and the HWRF indicating a track toward the west-northwest. Further still, the GFS shows Linfa remaining offshore and executing a counter-clockwise loop as it performs binary interaction with and is subsequently absorbed into Chan-hom. Given the forecast environment, the WHFC does not expect Linfa to quickly weaken as the NAVGEM indicates, and so a track into the South China Sea seems less likely at this time. The updated track forecast is a blend of the ECMWF and HWRF given the unpredictability of tropical cyclone-to-tropical cyclone interaction as indicated by the GFS. It should be noted, however, that the potential interaction with Chan-hom yields very low confidence, and further changes in model guidance will be monitored closely.
Now that Linfa is inland, little change in strength, if not slightly weakening, is forecast over the next 24 hours. Thereafter, modest intensification is expected over warm sea surface temperatures and within a low to moderate wind shear environment. The official forecast indicates Linfa to attain typhoon status in 48 hours. After 72 hours, the cyclone is expected to interact with Taiwan and mainland China, and steady weakening is forecast a result. The intensity forecast remains complicated because of the potential for Linfa to interact with Chan-hom, and the values listed below are of low confidence.
INIT 04/2100Z 17.6N 122.1E 55 KT 65 MPH...INLAND
12H 05/0600Z 18.0N 121.4E 50 KT 60 MPH...INLAND
24H 05/1800Z 18.6N 120.8E 50 KT 60 MPH...OVER LUZON STRAIT
36H 06/0600Z 19.7N 120.9E 55 KT 65 MPH
48H 06/1800Z 20.5N 121.0E 65 KT 75 MPH
72H 07/1800Z 21.6N 121.8E 75 KT 85 MPH...APPROACHING TAIWAN
96H 08/1800Z 23.9N 119.8E 60 KT 70 MPH...OVER TAIWAN STRAIT
120H 09/1800Z 23.9N 118.7E 50 KT 60 MPH...OVER TAIWAN STRAIT
$$
Forecaster TAWX14