La Manzanilla.info Message Board Archives

Re: Chance of rain increasing for weekend

Posted by Bret B on March 10, 2015, 5:01 pm, in reply to "Slight chance of rain in next 10 days?"
187.148.141.155

Summary:

My forecast resources are converging more and more on the consensus that we will have a good chance of significant rains this weekend. This is most bizarre!

And not just computer models are getting crazy: on my drive up to Perula and back this morning, there were a few sprinkles. Then when I got home I saw this over the mountains not far to our east:



Thunderstorms in March? This is exactly what we see in June! (After a while these storms got sheared off and pushed inland. No rain for us, ALSO just like June.)

Details:

W.U. now says 50%-75% chance of rain Saturday, Sunday and Monday, with total 3-day accumulation of over 2" (!) http://www.wunderground.com/q/locid:MXJO0760?

CONAGUA says ( http://smn.cna.gob.mx/boletin/discusion/discusion.html ):
> Today (Tuesday): Parts of Jalisco get 1-2".
> Tomorrow (Wed): Parts of Jalisco have 60% chance of 0-1".
> Thur: nothing.
> Fri: 0-1" for somewhere in Jalisco.
> Sat: 1-3" for somewhere in Jalisco.

GFS computer model ( http://www.hpc.ncep.noaa.gov/mike/gfs/crb_p24i_loop_12.html ) shows a very heavy band of rains soaking the coast in Michoacán and Colima Sat, Sun, Mon, with total 3-day accumulations above 4" in this band. We are close to the edge of the band, so if anything shifts it north very much we could get a few inches:


Here's another site to make you start building an ark. I check it frequently, but I don't know how accurate it is. We'll see: http://wxmaps.org/pix/prec3.html They predict a total accumulation over the next 7 days of about 4" for us, with peaks of 10" within a couple hundred miles of us (!!)


Possible causes:

The only mention I've found is in today's Tropical Weather Discussion for the East Pacific ( http://www.nhc.noaa.gov/text/refresh/MIATWDEP+shtml/ ): "MEANWHILE AN UPPER TROUGH REACHES FROM THE CENTRAL PLAINS THROUGH THE SOUTHERN ROCKIES OF THE U.S...THEN SOUTHWARD ALONG
105W AND OFF THE CENTRAL MEXICAN COAST. AN AREA OF ASSOCIATED SHOWERS AND THUNDERSTORMS IS ACTIVE ONSHORE OVER JALISCO STATE IN MEXICO NEAR THE BASE OF THIS TROUGH...BUT WITH NO SIGNIFICANT
WEATHER NOTED OFFSHORE. GLOBAL MODELS INDICATE AN UPPER LOW WILL CUT OFF OVER THE SOUTHERN TIP OF BAJA CALIFORNIA FRI AND SAT. ALONG WITH INCREASED MOISTURE THIS WILL ALLOW INCREASED CHANCES
FOR SHOWERS AND THUNDERSTORMS ALONG THE MEXICAN COAST NEAR MANZANILLO LATE IN THE WEEK."

I'll try to keep you posted...
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