WPAC: SEVERE TROPICAL STORM LUPIT (22W)

[WindRunner]

It looks like the JTWC is leaning heavily on older runs of the GFS (I believe it was the 06z run from almost 24 hours ago now that stalled the typhoon south of Japan). Interesting read in their 24/03z discussion:

3. FORECAST REASONING
A. THE FORECAST REASONING HAS CHANGED SIGNIFICANTLY SINCE THE
PREVIOUS PROGNOSTIC REASONING BULLETIN.
B. BASED ON CURRENT MOTION AND A MORE DEFINED STEERING
INFLUENCE, TS LUPIT IS EXPECTED TO CONTINUE ON A FASTER (THAN THE
PREVIOUS FORECAST) EAST-NORTHEASTWARD TRACK THROUGH TAU 72. THE
INTENSITY WILL SLOWLY DECREASE OVER THE NEXT 72 HOURS AS DRY AIR
ALONG THE WESTERN PORTION OF LUPIT CONTINUES TO INTRUDE UPON THE
CENTRAL PORTIONS OF THE SYSTEM AT THE MID- AND UPPER-LEVELS.
ADDITIONALLY, THE SYSTEM WILL START TO ENCOUNTER INCREASINGLY
UNFAVORABLE VERTICAL WIND SHEAR AS IT GAINS LATITUDE. NUMERICAL
GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 72 WITH A TRACK SOUTHEAST
OF OKINAWA, JAPAN. HOWEVER, THE GFS AND TCLAPS SOLUTIONS ARE WESTERN
OUTLIERS THAT DEPICT A FASTER, MORE INTENSE SYSTEM. THESE SEEM
UNLIKELY GIVEN THE FORECAST VERTICAL WIND SHEAR. FINALLY, BASED ON
SHIP OBSERVATIONS ON THE PERIPHERY OF LUPIT, THE 34-KNOT WIND FIELDS
HAVE BEEN EXPANDED TO SHOW A SLIGHTLY LARGER SYSTEM.
C. THE REASONING FOR THE FORECAST TRACK BEYOND TAU 72 HAS CHANGED
SIGNIFICANTLY. LUPIT IS STILL EXPECTED TO WEAKEN CONSIDERABLY AS IT
SUCCUMBS TO THE EFFECTS OF DRY AIR ENTRAINMENT AND HOSTILE VERTICAL
WIND SHEAR. HOWEVER, THE LOW LEVEL CIRCULATION CENTER OF THE SYSTEM
IS NOW EXPECTED TO DRIFT WEST-SOUTHWESTWARD AS IT WEAKENS IN
INTENSITY, DECOUPLES FROM THE UPPER-LEVEL CIRCULATION AND STARTS TO
TRACK WITH THE LOWER-LEVEL NORTHEASTERLY FLOW AS A 700-MB RIDGE IS
FORECAST TO BUILD EASTWARD OVER JAPAN. THE MODEL GUIDANCE AFTER TAU
72 IS HIGHLY DEPENDENT ON FORECAST INTENSITY. THE MODEL AIDS THAT
MAINTAIN THE SYSTEM'S INTENSITY SHOW A MORE NORTHEASTWARD TRACK
WHILE THOSE THAT DISSIPATE THE SYSTEM SHOW IT TRACKING ABRUPTLY BACK
TO THE WEST.//
NNNN

[oaba09]

It looks like the JTWC is leaning heavily on older runs of the GFS (I believe it was the 06z run from almost 24 hours ago now that stalled the typhoon south of Japan). Interesting read in their 24/03z discussion:

3. FORECAST REASONING
A. THE FORECAST REASONING HAS CHANGED SIGNIFICANTLY SINCE THE
PREVIOUS PROGNOSTIC REASONING BULLETIN.
B. BASED ON CURRENT MOTION AND A MORE DEFINED STEERING
INFLUENCE, TS LUPIT IS EXPECTED TO CONTINUE ON A FASTER (THAN THE
PREVIOUS FORECAST) EAST-NORTHEASTWARD TRACK THROUGH TAU 72. THE
INTENSITY WILL SLOWLY DECREASE OVER THE NEXT 72 HOURS AS DRY AIR
ALONG THE WESTERN PORTION OF LUPIT CONTINUES TO INTRUDE UPON THE
CENTRAL PORTIONS OF THE SYSTEM AT THE MID- AND UPPER-LEVELS.
ADDITIONALLY, THE SYSTEM WILL START TO ENCOUNTER INCREASINGLY
UNFAVORABLE VERTICAL WIND SHEAR AS IT GAINS LATITUDE. NUMERICAL
GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 72 WITH A TRACK SOUTHEAST
OF OKINAWA, JAPAN. HOWEVER, THE GFS AND TCLAPS SOLUTIONS ARE WESTERN
OUTLIERS THAT DEPICT A FASTER, MORE INTENSE SYSTEM. THESE SEEM
UNLIKELY GIVEN THE FORECAST VERTICAL WIND SHEAR. FINALLY, BASED ON
SHIP OBSERVATIONS ON THE PERIPHERY OF LUPIT, THE 34-KNOT WIND FIELDS
HAVE BEEN EXPANDED TO SHOW A SLIGHTLY LARGER SYSTEM.
C. THE REASONING FOR THE FORECAST TRACK BEYOND TAU 72 HAS CHANGED
SIGNIFICANTLY. LUPIT IS STILL EXPECTED TO WEAKEN CONSIDERABLY AS IT
SUCCUMBS TO THE EFFECTS OF DRY AIR ENTRAINMENT AND HOSTILE VERTICAL
WIND SHEAR. HOWEVER, THE LOW LEVEL CIRCULATION CENTER OF THE SYSTEM
IS NOW EXPECTED TO DRIFT WEST-SOUTHWESTWARD AS IT WEAKENS IN
INTENSITY, DECOUPLES FROM THE UPPER-LEVEL CIRCULATION AND STARTS TO
TRACK WITH THE LOWER-LEVEL NORTHEASTERLY FLOW AS A 700-MB RIDGE IS
FORECAST TO BUILD EASTWARD OVER JAPAN. THE MODEL GUIDANCE AFTER TAU
72 IS HIGHLY DEPENDENT ON FORECAST INTENSITY. THE MODEL AIDS THAT
MAINTAIN THE SYSTEM'S INTENSITY SHOW A MORE NORTHEASTWARD TRACK
WHILE THOSE THAT DISSIPATE THE SYSTEM SHOW IT TRACKING ABRUPTLY BACK
TO THE WEST.//
NNNN

Now I'm confused

[WindRunner]

Since you quote my rpost before I could add this in, I'll put this down here...

Personally, I feel this option they are going with is highly unlikely. I do agree with the quicker track, but for the system to vertically decouple and for the LLC to be left behind in the tropics seems unreasonable. Tonight's 00z GFS has a nice solution in keeping the cyclone moving quickly and keeping the energy associated with the storm in one piece - something that actually looks like a typical recurving typhoon. Granted, we all know Lupit so far is anything but typical, but we shall see. Also of note, the GFS track does deliver a glancing blow to Japan, with the center of the storm skirting near/on the coast - probably with effects similar to those of Melor, assuming this forecast verifies perfectly

Regardless, still something the Japanese archipelago needs to watch for, even if JTWC is yet again being stubborn with their forecast.

[ozonepete]

Since you quote my rpost before I could add this in, I'll put this down here...

Personally, I feel this option they are going with is highly unlikely. I do agree with the quicker track, but for the system to vertically decouple and for the LLC to be left behind in the tropics seems unreasonable. Tonight's 00z GFS has a nice solution in keeping the cyclone moving quickly and keeping the energy associated with the storm in one piece - something that actually looks like a typical recurving typhoon. Granted, we all know Lupit so far is anything but typical, but we shall see. Also of note, the GFS track does deliver a glancing blow to Japan, with the center of the storm skirting near/on the coast - probably with effects similar to those of Melor, assuming this forecast verifies perfectly

Regardless, still something the Japanese archipelago needs to watch for, even if JTWC is yet again being stubborn with their forecast.

Who could say it better than that? I'm totally in agreement with you.

[StormingB81]

I wonder why with the winds still being over 50 knots why Okinawa isnt in a TCCOR yet. Oh well.

[ozonepete]

I wonder why with the winds still being over 50 knots why Okinawa isnt in a TCCOR yet. Oh well.

Because you'll be on the weaker side (the left side along the direction of motion). Remember that the left side of an advancing cyclone is weaker because the forward motion is SUBTRACTED from the storm winds. So if a 50 knot cyclone is headed for you at 20 knots forward speed but you're on the left side of it, your expected wind speed will be 50 minus 20 = 30 knots.

[StormingB81]

Got it Thanks!

[ozonepete]

Got it Thanks!

You're welcome. We'll have a few more storms to follow this season from the looks of it.

[StormingB81]

I just got a call to move planes. I wasl ike its not goign to be bad and they said we could have up to 50 mph winds tonight.

[JTE50]

I am in Manila waiting for my 11pm flight back to Guam. Lots of press from Aparri caught the flight from Tuguegarao to Manila. GMA Channel 7 and 2 in Manila. Aljazeera from Malaysia, and some others. CNN from Bangkok, Thailand made it as far as Tuguegarao. If you live in Manila, tune in to GMA from 8:30-9pm. I'll be on the News. I had a wonder experience with the Philippino people on this trip.

[oaba09]

I am in Manila waiting for my 11pm flight back to Guam. Lots of press from Aparri caught the flight from Tuguegarao to Manila. GMA Channel 7 and 2 in Manila. Aljazeera from Malaysia, and some others. CNN from Bangkok, Thailand made it as far as Tuguegarao. If you live in Manila, tune in to GMA from 8:30-9pm. I'll be on the News. I had a wonder experience with the Philippino people on this trip.

We'll be watching that Great job!!

[metenthusiast]

This is a multi-agency model from typhoon2000.ph
Look at the model from NGPI, it seems to be coming back staright for the Philippines...

[StormingB81]

Does this storm look like it is trying to reorganize and strengthen?

[oaba09]

Even if it's already at a weakened state, this storm is still interesting to observe because of the different possibilities of where this system might go...

[metenthusiast]

Even if it's already at a weakened state, this storm is still interesting to observe because of the different possibilities of where this system might go...

You're right about that. This is the first time to try tracking a storm and never knew that it would give me such a headache. I already feel nauseated just looking at its past tracks, not to mention the forecasts...

[oaba09]

I am in Manila waiting for my 11pm flight back to Guam. Lots of press from Aparri caught the flight from Tuguegarao to Manila. GMA Channel 7 and 2 in Manila. Aljazeera from Malaysia, and some others. CNN from Bangkok, Thailand made it as far as Tuguegarao. If you live in Manila, tune in to GMA from 8:30-9pm. I'll be on the News. I had a wonder experience with the Philippino people on this trip.

Saw you on the news jim...

[drdavisjr]

Looking at both the models and the forecast reasoning by JWTC, I think the models are trying to compensate for a weakened system. My question is, for anyone that has a theory, can this system do both; reorganize and strengthen AND move back to the southwest?

[StormingB81]

Well now JMA is saying We can get over 50 knot winds. Its still pouring here. winds are calm for the time being. now lets see if it turns into the east or goes to the southwest like some models are saying

[drdavisjr]

Well now JMA is saying We can get over 50 knot winds. Its still pouring here. winds are calm for the time being. now lets see if it turns into the east or goes to the southwest like some models are saying

It looks like by JTWC that it is up to Dvorah CI# 2.9 and slowly intesifying...992.5mb and falling...be safe

[oaba09]

I'm not exactly sure but it seems like lupit is trying to reorganize...