South meets north - Mei yu pt 2

On the homepage, my favorite sat, the one with the basic descriptions, says something like:
remnants of tropical disturbance 3W is absorbed by stationary front.
Technically, that's the ingredients of a 'perfect storm', though obviously not to the same degree, but it should create something, and it's happening right around here. You can see that the whole weather theatre around Taiwan is pretty unstable right now.

I noticed that and it does look like it could lead to a few days of sometimes heavy rain. It looks like that storm is going to merge with the mei yu front, or has merged rather. Interesting.

Looks like the southern tip of Taiwan has already had over 100mm today, and it's only 9am.

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This is a classic mei yu weather chart - a stationary front right over Taiwan - and when they say 'stationary', they're talking 5-6 days. Anyway, looks like the island is in for a bumby ride over the next week.

It took a while, but May 20, we finally got a solid, soaking mei yu. 'Stationary' cold front, which has actually been oscillating over Taiwan - had dipped down south for the last two days, but came back with interest bringing the biggest rain of the year to Taidong. three days ago we got 15ml, then nothing, though overcast skies, then today it started raining steadily around 5 in the morning and hasn't let up since then (10am)- we are up to 15 so far and still going strong. Noticed clouds rushing up from the south yesterday evening and chugging north, which was curious coz there was no ground level wind at the time - thought that might have been a sign of something coming and seems it was.Front is being fed by areas of moisture to the south - two more low pressures to the east of ppe have also formed and these should add to the whole thing in the coming week.

Another mei yu front passed over the island on May 26-27 but failed to produce any significant rainfall in Taidong (100ml in central mountains of Taiwan)despite 80% pop predictions. This may have been affected by a typhoon away to the east and heading north. Could be that it had a draining effect on the mei yu front, whereas a low pressure system to the south tends to feed moisture into the mei yu through their outlet stream. Another front predicted for Thurs - this could be interesting coz it is expected to wrap around the south east coast - also a cyclone system building to the south east. if that stays low, then you would expect large rainfall totals on the east coast. And there would be need to be to get anywhere near the average of 156ml for May. We are currently sitting on about 60ml with just a few days left.
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It looks like an interesting week ahead. There's a lot of moisture out there, and with the low you mentioned mixed into the equation, things could get interesting.

One must give credit where credit is due, and I do my share of complaining about the CWB, but this time they did correctly predict heavy rain for Taitung. This cell sitting over us right now looks like it will keep us in rain for much of the night. I'm not convinced we'll get 'extremely heavy rain', but it's possible. What is 'extremely heavy rain' anyway? Is it anything over 50mm? If so, we'll probably reach that. I doubt we make 100 though. Maybe 80 by the time this thing passes.

That low building east of the Philippines looks ominous. With this mei yu, semi-stationary front over us, I can't see it coming this way, but I'd say it will definitely affect us if it develops. It looks like it would most likely take a straight western path. But it could feed into this front. The only other thing it might do if it develops is take a NNE path, but I think it's already too far west for that.

We're living in interesting weather times.

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That's the positional prediction at this stage for this Sunday - looks like it will get reasonably close but will most likely chase the tail of the front up and curve north east. Anyway, should have some sort of effect here.

Finally, the first big downpour of the mei yu season has arrived on May 29. Oddly enough, it only happened when the front had passed over us (going north to south). Was preceeded by a burst of strong north east wind and the sight of an impressive band of dark rain clouds out to sea. Started around 10.30am and has continued raining all day with a few breaks. Late afternoon the rain stopped for a while, but then the sky turned quite dark and soon started up again with added vigour and has continued to rain heavily since. Up to about 40ml by now and if it keeps up at this rate i'd say we could get to 80-100 or more by tomorrow morning. Fengbing in Hualien has already had 200. Started on north east coast, crept down the coast, and then spread island wide.
Two low pressures to the S of Taiwan may be responsible for a lot of the moisture in the system.

Update: it's 11.30 and i've collected 120 ml in my rain guage and it's still going strong - getting about 30ml an hour - this could go as high as 200. We've managed to go from well below the monthly ave to well over it in a single day. Plus there's lots more instability about for the whole of this week.

Final Rainfall for XC, May 29, 2012: 198ml (from abt 10am to 2-3am the next day)

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rainfall as of 11.00pm. Interestingly, the west coast is virtually dry - shows the rain is coming in from the north east and not making it past the central range. But that doesn't explain a patch just south of Taidong city that also seems almost dry.

Looks like the mei yu is hitting its full stride at the moment with a massive deluge across most of the island. Strangely enough, about the only place it didn't rain was in the far north, thank God, cause i was there to do the market. There was a 90% prediction on rain in Taipei for Sat-Sun, but it didn't come. However, there were falls of 600+ in parts of pingdong - that's a major typhoon level of rain that would almost certainly cause serious flooding and landslides.
Sat maps so a tremendous amount of moisture getting around in the atmosphere over north ppe, china, and Taiwan
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note: this is the 'panel 2' that you have to select on the CWB site to get a reading of falls over 300. Rain is contining into the morning of the 11.

Doesn't particular seem to feature a front - not where the rain fell - though one is predicted to come through in the next few days.

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The deluge continues. Yesterday, June 11, was pretty much a carbon copy of the day before (pingdong ending up with over 1000ml across the two days), while today the biggest falls seem to be in the north west (close to 300 at 6,30am), though the radar suggests the south west is about to get totally hammered with a large patch of intense rainfall showing up on the radar just off Tainan.
The rain band is travelling in a north easterly direction as per the monsoon flow and appears to be worst on the eastern edge of a front coming down from the north west.
55ml in XC on June 10, and 18ml on June 11. Lots of thunder and lightning about, though as usual, not happening right here. Have noticed that the thunder seems to come as extra long rumble - not sure why - could be just echoing down the the rift valley - but still seemed to be like that even when it was coming from the north east so may have something to do with being elongated cloud to cloud thunder. A lot of the thunder was rumbling on for 30 secs or more.
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I was told that there is flooding in Taimali, which might seem unlikely given the relatively light rain we've had farther north on the east coast. But I was just in Zhiben and the lightening was right on top of me, and it looked very dark to the south.

While living in Pingtung, the worst flooding I ever saw was mei yu flooding. It must have been around 2003 or thereabouts, but it rained constantly for over two weeks, or was it three? And as the days went by, the rain got heavier before it finally ended. It was very destructive.

We could be looking at a similar situation here. This could go on for a couple more days at least, then there's this looming tropical storm heading this way.

This screen grab pretty much sums up the situation. If we had an earthquake, they'd almost run out of space.

I find it interesting that this makes national news only after it hits Taipei. This is why the event I alluded to earlier wasn't big news in Taiwan. I had a friend visit at the time who was staying in the Taoyuan area, which wasn't being affected. He had no idea what was going on in the south. But, oh my, if it affects Taipei, then it's something.

http://udn.com/NEWS/LIFE/LIF2/7154274.shtml

But, oh my, if it affects Taipei, then it's something.

It was the same with Morakot. I remember looking at the off the chart rain totals and then switching on the TV to see what was going on and there was just the usual procession of popstar and food stories. I think Ma Ing Jiu was watching the same channel, judging by the govt's delayed response.

Anyway, that's our job now.

Looking at the radar, it might be about to take a turn for the worse over this side in the next few hours. It was interesting to read what you said about it cranking up in Chihben. Large chunks of the storm are now slipping under the southern penninsula and starting to slide up towards us. Despite what feels like steady persistent rain for three days, we've actually had almost the least of anywhere on the island - so far.

And then again, a typhoon approaching from the east would fix that as well.

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This rain chart is almost a thing of beauty. Not sure i've seen the island so uniformly wet too many times. The amount of water shooting down into the rivers off that central spine range must be incredible.

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By comparison, here's a chart from a few days later: Strangely, while rain fell on the coast, the mountains remained dry. ???

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Yep, it's an amazing image, as is this one. It looks ominous.

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And keep in mind whereas a typhoon (Morakot being an exception) will generally pass in a few days, this sort of situation can easily persist for ten days or more. What I saw with mei yu flooding in Pingtung was ground that had been absolutely saturated for a week or more, getting 1,000+ of rain as we already have, then getting hit by torrential rain. It's a very different situation from a typhoon.

But now, wow, we have the ground absolutely saturated, holding as much water as it can, with a tropical storm coming. If that storm dumps another 1,000+ on us starting six days from now, things will get quite messy.

What I'm wondering is how will this stationary front and this storm interact. The storm is predicted to curve north, but the bands are what matter. Where is the moisture going to go? Because there's a lot there right now.
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And on it goes. We are now into day 5 and after a bit of a lull yesterday it has cranked right back up today. The south west is still copping it - expect further flooding and landslides there today - but now it is starting to seriously affect the east coast as well. Just south of Taidong they have already had 100ml and still pouring and it appears to be creeping up the coast.

In XC, we are up to 60ml. Poured early this morning, then a break and the sun even shone through for 30 or so mins, but now it has turned so dark that i need the lights on in the house to type this - and i've got full ceiling to floor windows!

The scary thing is that there looks to be a heap more in the pipeline. I've got grave concerns about what's going to happen if that huge blob of rain to the south west makes its way up here - and it certainly looks like it is coming this way - that has been the pattern, coming up with the monsoon flow. There's a low pressure there and the size of it, rain wise, is more than double that of the typhoon to the south east. I'd love to take a look at the record books - i doubt Taiwan has seen a mei yu event of this magnitude for quite some time. Pingdong does have a whopping 374ml mean for June, but they would have had more than triple that in the last few days alone.

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Rainfall chart up to 10pm - torrential rain still ongoing on mid west coast.
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Aside from the possibility of some rainless hours in the next day or so, it looks like we're in for at least a few more days of rain. Even if Guchol manages to pull some of this weather away from us, there's so much moisture sitting to our SW that I just don't see any way for things to clear up for at least a few days. I hope I'm wrong.

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When i looked at the sat map this morning it did seem to have cleaned up quite a lot so i went down to the the bei nan river to get some driftwood (a lot there by the way). For the first five minutes, there was just a bit of drizzle, but then it settled in again. In fact looking at it again after i got back, i think it might be our turn today to cop it. The system seems to be feeding straight into us while other parts of the island are relatively dry.

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Contrary to what i thought previously, the weather doesn't seem to happen on the actual front, but rather, if you campare the radar with weather map, a couple of hundred km's from its leading edge (eastern in this case) - either that or CWB has drawn the front in the wrong place, which is also a distinct possibility.

Anyway, you can see the mechanics of the thing quite clearly. This big stationary low to the south west feeding moisture up through the stationary mei yu front. The result: a week long deluge across Taiwan. Interestingly, the front has retreated back to the west somewhat and is still showing no signs of breaking up and receding to the north as it was forecast to do. Not sure what implications that has for the typhoon.
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I think the implications are dire. There's a tremendous amount of moisture SW of us, feeding our way, via a stationary front. Guchol. although predicted to curve north, has headed west so far, Even if Guchol does take a sharp north turn in the next 36 hours, as predicted, I can't see any way that this would do anything but bring more moisture our way. Guchol is already too far west to dry us out via a north turn. The only thing that would pull moisture away from us would be a recurve of Guchol to the NE... and even that might not help.

Think the Mei Yu can be offically pronounced over. In fact, our last mei yu rain was the June 10-15 deluge. That was followed in a few days times by a typhoon and now it can be clearly seen that the mei yu front has moved to the north and will start to affect Japan and northern China. From this point until October, our only rain will come from typhoons (or tropical depressions at least). Well that's been the case in previous years - just don't seeem to get that afternoon thunderstorm type relief thing here - unfortunately - my only real gripe about Taidong. And for the next tow months and a bit there's only two speeds - and both of them are extremes - brutal heat or typhoons. Go the typhoons!

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South meets north - Mei yu pt 2 (Weather)