For a more recent update regarding the changing forecast track of Typhoon Lupit, CLICK HERE
The general forecast thinking regarding the Typhoon Lupit Track and Intensity is really not much changed. The storm is looking pretty good on the satellite loop, though it does seem to have some deformation. Both the GFS and US Navy NOGAP model takes the storm either skirting the northern coast of the Philippines or through the Luzon Strait. As a side note, if you look at Vietnam, you see that it is still getting pummeled by the remnant of Parma. Anyway, as far as Lupit is concerned, there is consensus regarding a deepening tropical cyclone making landfall midweek or at least affecting the Philippines at that time. The official track seems to mirror the GFS, which handled Typhoon Parma pretty well. The NOGAPS wants to keep the center just north of the northern coast of the Philippines but curiously it also decreases the intensity as it passes, which makes me think that the model is accounting for quite a bit of land interaction and may in fact have the eye go over land.
WDPN31 PGTW 161500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 22W (LUPIT) WARNING NR 011//
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TYPHOON (TY) 22W (LUPIT) IS LOCATED APPROXIMATELY 400 NM
NORTH OF PALAU AND HAS TRACKED WESTWARD AT 17 KNOTS OVER THE PAST
SIX HOURS. TY LUPIT HAS DEVELOPED AN IMPRESSIVE CONVECTIVE STRUCTURE
EVIDENT IN A 160859Z SSMI MICROWAVE IMAGE AS WELL AS IN RECENT
ANIMATED INFRARED IMAGERY WHICH SHOWS A TIGHTLY WRAPPED SYSTEM WITH
A BANDING EYE. LUPIT’S INTENSIFICATION TO TYPHOON STRENGTH HAS BEEN
ENABLED BY EXCELLENT POLEWARD OUTFLOW INTO THE MID-LATITUDE
WESTERLIES. ANIMATED WATER VAPOR IMAGERY ILLUSTRATES THAT LUPIT IS
TRACKING SOUTH OF THE VERY NARROW (ONLY ABOUT TEN DEGREES, NORTH TO
SOUTH) SUBTROPICAL RIDGE AND HAS ACCESS TO THE MID-LATITUDES DUE TO
THE DEVELOPMENT OF AN ANTICYCLONE ALOFT. THE CURRENT INTENSITY IS
BASED ON DVORAK ESTIMATES OF T4.0 FROM PGTW, KNES AND RJTD. THE
CURRENT POSITION WAS PLACED, WITH GOOD CONFIDENCE, BETWEEN THE PGTW
AND RJTD FIXES.
3. FORECAST REASONING.
A. THE FORECAST REASONING HAS NOT CHANGED SINCE THE PREVIOUS
PROGNOSTIC REASONING BULLETIN.
B. OVER THE NEXT 72 HOURS, TY 22W IS EXPECTED TO CONTINUE
TRACKING GENERALLY WEST-NORTHWESTWARD ALONG THE SUBTROPICAL RIDGE.
BY TAU 24, THE SYSTEM IS EXPECTED TO SLOW IN FORWARD TRACK SPEED AND
TAKE A SLIGHT POLEWARD TURN AS A MID-LATITUDE TROUGH, CURRENTLY WEST
OF KOREA, TEMPORARILY WEAKENS THE SUBTROPICAL RIDGE AND CAUSES A
WEAK STEERING ENVIRONMENT. WHILE TRACKING WESTWARD, LUPIT WILL REMAIN
IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY MINIMAL VERTICAL WIND
SHEAR, EXCELLENT POLEWARD OUTFLOW INTO THE MID-LATITUDE WESTERLIES
AND OCEAN HEAT CONTENT VALUES IN EXCESS OF 100 J/KG/CM^2.
C. BY TAU 72, TY 22W SHOULD RESUME TRACKING WESTWARD AT AROUND
10 KNOTS AS THE MID-LATITUDE TROUGH PASSES TO THE EAST AND THE
SUBTROPICAL RIDGE REGAINS ITS STEERING INFLUENCE. AS LUPIT MAKES ITS
WAY THROUGH THE PHILIPPINE SEA, THE SYSTEM SHOULD CONTINUE TO
STEADILY INTENSIFY AS THE ENVIRONMENT IS FORECAST TO REMAIN
FAVORABLE. HOWEVER, BY TAU 120 LUPIT SHOULD DECREASE IN INTENSITY
DUE TO LAND INTERACTION OVER NORTHERN LUZON. THE NUMERICAL MODEL AIDS
ARE STILL IN VERY GOOD AGREEMENT WITH A JOG TO THE NORTHWEST DUE TO
THE MID-LATITUDE TROUGH AS WELL AS A RETURN TO A MORE WESTWARD TRACK
TOWARD NORTHERN LUZON IN THE EXTENDED TAUS. HOWEVER, THE AIDS
CONTINUE TO VARY ON THE TIMING OF INTERACTION AND THE DEGREE TO
WHICH THE TROUGH WILL AFFECT THE TRACK OF 22W. OVER THE LAST 24
HOURS, THE NOGAPS AND GFS MODELS HAVE STARTED TO DEPICT AN
INCREASINGLY DEEPER TROUGH WHICH WOULD CAUSE TY 22W TO TURN TO THE
NORTHEAST FOR A PERIOD OF ABOUT 12 HOURS BEFORE RESUMING A WESTWARD
TRACK. HOWEVER, THOSE PARTICULAR MODELS HAVE SHOWN A POLEWARD BIAS
THIS SEASON AND, IN CONSIDERATION OF THE CURRENT ZONAL MID-LATITUDE
PATTERN, THIS FORECAST FAVORS THE EUROPEAN SOLUTIONS OFFERED BY
ECMWF AND UKMO WHICH SLOW THE FORWARD TRACK SPEED CONSIDERABLY BUT
DO NOT DEPICT AS AGRESSIVE A TURN NORTHWARD.//