Sunday, August 06, 2006

Moisture surge knocking on the door

I have been e-mailing with Mike Leuthold this afternoon about the liklihood of an overnight surge of low-level moisture up the Gulf of California (GoC). It appears likely that the large areas of active convection over the southern GoC, and also south of the mouth of GoC have triggered at least a moderate surge. Expect the influx to show up at Yuma by early morning Monday. Moisture is also increasing from the east, so storm activity should increase next couple of days, even though mid-level temperatures are relatively warm.

The warm, dry air aloft that came in from the south on Friday really shut things down, since it eliminated what CAPE there had been. It was a nice example of how things here in southern Arizona can go totally suppressed, even though low-levels remained fairly moist. The situation was also interesting since the NAM runs on Friday kept showing precip here every 6 hour period through Saturday night. The NAM has been forecasting cyclones and waves south of Tucson for a number of days, but today is first day that observations show much. It's not clear whether there is any cooler mid-level air lurking over Mexico - there have been almost no soundings over much of Mexico since the third week of July. This may be the reason that the NAM initializations and forecasts have been so unreliable of late.

So, we'll see what tonight and tomorrow bring.

1 comment:

  1. Anonymous5:45 PM

    To bad no sounding from GYM this morning but GOES precipitable water loops show surge pushed into that area this morning. Big storms down there today should push the surge moisture into Arizona Monday morning. Should see a pressure jump at Hermosillo tonight (06zish) which would signal the surge is on the way.

    Pat Holbrook

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