La Manzanilla.info Message Board Archives

Rain report

Posted by Bret B on February 1, 2015, 9:03 am
187.148.42.138

Well hello rain! We have received 0.8" / 20mm since it started with a gusher around midnight, and it's still coming down moderately. Too bad about all those soggy partyers over on the Boca beach. I can hear the bass part of the music, so at least the electronics are still working for now...

I was expecting a chance of rain around Monday/Tuesday, so this early start took me by surprise. It doesn't look like much on the GOES-West IR satellite loops, just some light blue streaming over us.

Wide view: http://www.ssd.noaa.gov/goes/west/epac/flash-avn.html

Close-up on our part of Mexico (La Manz is roughly in the center of this view): http://smn.cna.gob.mx/satelite/goesE/co/loop.gif


The passive microwave radiance data from the TRMM satellite shows actual rain falling, but time-delayed by a few hours. There were some light showers with some embedded thunderstorms offshore to our NW when the latest overflight happened:

http://trmm.gsfc.nasa.gov/trmm_rain/americas/americas_3hrly_zoom.gif


So what about the forecast? Well, for the first time in several days I actually think that the Weather Underground forecast is believable. (It had been predicting ridiculous amounts of rain for the last few days, with no basis in any computer models that I could find.)

http://www.wunderground.com/q/locid:MXJO0760?


So expect even more rain Monday (tomorrow) and Tuesday.

For the weather nerds, here are a couple fairly reliable computer models showing the predicted 24-hr rainfall accumulations.

The "old reliable" GFS model shows moderate-to-heavy rainfall in a swath just to our north from now through Tuesday. If this swath slides south very much we would get quite a bit more rain:
http://www.hpc.ncep.noaa.gov/mike/gfs/crb_p24i_loop_12.html

The Mexican SNM / CONAGUA site now carries a spiffy computer model viewer. It's a little buggy so you just have to explore it to see what's going on:

http://smn.cna.gob.mx/index.php?option=com_content&view=article&id=16&Itemid=87

You can see their view of the GFS model data is about the same as the NOAA site (link is above.) But check out their in-house modified version of the WRF model (click on "WRF-SMN"). That model shows us getting much more rainfall. The total accumulation over the next 72 hrs shows us teetering on the edge between around 500mm / 2", and a heavy area of rainfall just offshore that peaks up to 400mm / 8" !! Hopefully THAT mess won't shift over us!


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Re: Rain report

Posted by Debbie W on February 1, 2015, 9:45 am, in reply to "Rain report"
189.164.239.63

Thanks Bret
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Re: Rain report

Posted by Lisa Fern on February 1, 2015, 10:04 am, in reply to "Rain report"
187.148.141.253

Bret, Is this lovely rain unusual for this time of year?
I feel responsible since I washed my clothes yesterday and was going to hang them out today.

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Re: Rain report

Posted by Teresa perryt on February 1, 2015, 12:31 pm, in reply to "Re: Rain report"
187.148.184.133

How fortunate we are to have such an assortment of specialists and professionals in the village.
I enjoy surfing the message board to see what I will learn.
That was some rain last night.there was a 4inch slug on the bathroom wall,along with a number of other critters trying to keep dry. You know it is over the top wet when the slugs take cover.
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Re: Rain report

Posted by Bret B on February 1, 2015, 12:38 pm, in reply to "Re: Rain report"
187.148.42.138

You're right, this is somewhat unusual for February, and if we get a lot more rain in the next couple days then that is even more unusual.

Here is a chart I whipped up last year, so it doesn't include the 2014 rain data. That doesn't matter in this case since there was no rain in Feb 2014 (nor most of Jan.)



My rain gauge got up to 1.0" this morning before the sun started coming out, so we are already over the historical average for the whole month!

By the way, the record maximum rainfall for the month of February from 2004 to now is 6.24" / 158mm, in 2010.
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Re: Rain report

Posted by Daniel H on February 1, 2015, 12:55 pm, in reply to "Re: Rain report"
187.148.212.242

I can understand the changing seasons, but why does February get rain
when the months on each side of it, January and March don't?
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Re: Rain report

Posted by Red on February 1, 2015, 4:22 pm, in reply to "Re: Rain report"
187.148.169.114

That's an easy one D. Nobody has paid the mordita for February yet to the rain gods. Hence, continued wet until we all fork over the Pesos!
Rojo
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Re: Rain report

Posted by Arleen on February 1, 2015, 6:44 pm, in reply to "Re: Rain report"
187.148.173.232

Daniel, porque febrero is loco, y tambien marzo, un poco. That is a Mexican saying. Not quite sure about the later half.
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Re: Rain report

Posted by helga on February 1, 2015, 9:40 pm, in reply to "Re: Rain report"
187.148.170.55

Arleen, that is supposed to be the wind, not the rain.
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Re: Rain report

Posted by jon pace on February 1, 2015, 9:47 pm, in reply to "Re: Rain report"

No, Helga, it is an old Jalisco saying about the rains in February. Not spelled nor presented quite right but the sentiment is there. I know that it hasn't rained regularly in La Manz in February for a while, but Jalisco is a big state and it has rained heavily in the Guadalajara/Lake Chapala area every year in February. Just never in our experience so soon after the month had begun.
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Re: Rain report - Monday

Posted by Bret B on February 2, 2015, 12:21 pm, in reply to "Re: Rain report"
187.148.42.138

Well we got 1.0" for the 24hrs ending this morning at 8am. So that's 1.8" since this "event" began. The forecast is for more rain today and tonight (another inch or so?) with a little more tapering off tomorrow.

Now we're having a nice thunderstorm with some heavier rain. I hope everyone gets to a safe place, especially those krazy kids in Boca. I'm signing off and unplugging my electronics until this lightning passes.
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Re: Rain report - Monday

Posted by dorinda on February 2, 2015, 12:53 pm, in reply to "Re: Rain report - Monday"
201.138.181.193

Perhaps we're getting that 8" mess off the coast afterall? I know jack about weather but this looks like a tad more than a couple of inches.
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Re: Rain report - Monday

Posted by Bret B on February 2, 2015, 3:22 pm, in reply to "Re: Rain report - Monday"
189.164.207.233

Is it safe to plug in to the power grid / lightning attractor again? My v2.0 soup can rain gauge says that thunderstorm dropped 1.7" / 43mm in about an hour. Pretty good rain rate! Sorry about the streets and the mess in the bay...

Here is a snapshot of the zoomed-in IR satellite loop showing the yellow elongated blob (presumably the thunderstorm) that passed directly over us:



On the wide view IR loop you can see there is more of the same colors here and there, all streaming up from the ITCZ toward our part of Mexico. It's a shooting gallery and we're the tin rabbit...

http://www.ssd.noaa.gov/goes/west/epac/flash-avn.html

Here is the latest TRMM data from a few hrs ago:



The Weather Underground predicts another 0.86" tonight and a little more tomorrow and that's it:
http://www.wunderground.com/q/locid:MXJO0760?

The Mexican model viewer ( http://smn.cna.gob.mx/index.php?option=com_content&view=article&id=16&Itemid=87 ) shows the GFS model saying we'll get 1-2" today and very little more tomorrow and Wednesday. About the same as WU. I would lean toward this myself also. Here's the GFS model for total accumulated rainfall for today, tomorrow and Wed:



Their in-house WRF-SMN model continues to be a lot wetter than the GFS. It shows us to be barely inside a small zone of 3-6" for today, then another 1-2" tomorrow. Here's the 3-day total accumulation (that's a BIG area of 3-6" surrounding us!):



The good news is that by Wednesday the weather should get back to normal for the foreseeable future.
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Re: Rain report - Monday

Posted by Judy B on February 2, 2015, 4:45 pm, in reply to "Re: Rain report - Monday"
201.138.183.22

You are soooooo good Bret B.
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Re: Rain report - Tuesday & post-mortem

Posted by Bret B on February 3, 2015, 10:11 am, in reply to "Re: Rain report - Monday"
187.148.141.155

We got 2.35" / 60mm since yesterday morning (mostly from the heavy thunderstorm yesterday afternoon.) 4.15" / 105mm storm total so far (3 days.)

All the forecast tools predict very little rain today for us, clearing gradually by this afternoon, then nothing else brewing for at least the next few days. However, a substantial plume of moisture might remain for a few more days, hopefully staying over the coast to our south. If the plume wanders back up here, our forecast could change.

What was causing this unusual February rain? There was a stubborn upper-level low pressure camped out between central Baja California and the mainland Mexican coast the last few days. In conjunction with a southern arm of the jet stream, this low pumped and guided a heavy plume of moist mid-to-upper level air from the inter-tropical convergence zone (down around 5° north latitude) over our part of the coast. Then we had a surface low pressure trough just off shore from us to give the moisture a "trigger" to precipitate out as rain.

Here is an excerpt from the NHC's Eastern Pacific Tropical Weather Discussion ( http://www.nhc.noaa.gov/text/refresh/MIATWDEP+shtml/ ):

"SW FLOW ALOFT E OF AN UPPER LEVEL LOW IS PUMPING MOISTURE INTO THE CENTRAL MEXICAN COAST...WITH SHOWERS MAINLY ALONG A TROUGH FROM 20N105W TO 13N110W. THE UPPER LOW WILL WEAKEN TODAY AND MOVE NE...BUT A SUBSTANTIAL MOISTURE PLUME IS EXPECTED TO REMAIN IN PLACE ACROSS THE REGION."

And here is an excerpt from their latest surface-level weather map. It's pretty cluttered. Hopefully you can see the trough (dashed line) aiming right at us. I added the upper-level low to our north with its counterclockwise circulation helping to pump the "moisture plume" along the trough right to us:



And what's behind these weather features? We can't blame El Nino; we are in "ENSO-neutral" conditions right now. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf Beyond that, I don't really know.
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