SOLPEX IOP2 concludes

Operations are winding down for SOLPEX IOP2.  Teams should be on their way home soon if they are not already.  Great job by everyone!  What an event.

We did well to collect data through 1800 UTC.  Things are falling apart quickly now as shown in the 1900 UTC radar image.

SOLPEX IOP2: Dangers of CW revealed

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Some reflections on IOP2 and forecasting lake-effect.  One of the more intriguing aspects of the event is the early development of a wind-parallel band over the SW corner of the lake.  This band trained into the northeast corner of Tooele Valley.

With flow out of the NW, most of us think about Salt Lake County being in the DLE cross hairs, but in this instance, the band initiated so far west that it impacted Tooele County.  Why there instead of near the mid-lake axis remains to be seen, but we can add the location of band initiation to the list of issues limiting our ability to forecast lake-effect location.

Further, NW flow is supposed to be good for the Cottonwood Canyons, but CLN has only received about 0.23" of SWE since midnight, which is barely a dusting by their standards.  I suspect that the SWE near campus was equal or greater than that (note that I don't trust the 0.06" reported by WBB).

Conventional wisdom can only get you so far with non-linear lake-land-atmosphere interactions.

SOLPEX IOP2: Oh what a night!

In the immortal words of Col. John "Hannibal" Smith, "I love it when a plan comes together!" A great event last night with lots of action.  This one should keep us busy for a while.

Overnight the wind-parallel band over the SW corner of the lake dissipated just prior to the 0600 UTC sounding launch.  Then things really got messy with wide spread precipitation, an occasional embedded band, and finally wide-spread coverage that presently appears to be detaching from the lake.



The 1200 UTC KSLC sounding shows we may have lucked out thermodynamically.  Yesterday's 12Z Nam forecast a 500 mb temperature of -25C this morning.  It appears we verified closer to -27.

The MesoWest analysis is quite interesting.  Temperatures cooled overnight across the region.  The lake-land temperature difference remains fairly modest, at least as indicated by the available obs.  The flow in the sounding and at PRP is quite weak. 

I'll dig in more and post anything else interesting in a bit.

SOLPEX IOP2 0430 UTC 9 Nov update

The wind-parallel band continues to intensify (image below for 0429 UTC).  There are now several 40+dBZ cores embedded in it.  It's remained absolutely locked on the Lake Point area.  I noticed the NWS is now highlighting it on their web site.

The corresponding MesoWest analysis shows relatively similar lake-land temperature differences compared to earlier, although a few of the land stations have cooled slightly.  Perhaps the most substantial change is the increased flow on the lakeside mountains, for reasons I do not understnd.  Concurrently, the flow on the east side as weakened.  The HAT-PRP temperature difference is now 8C, consistent with steepening lapse rates observed in the east-side soundings.  

We're in business!  Our teams will be taking soundings while you sleep.  Keep your fingers crossed.

SOLPEX IOP2 Soundings - 0000 and 0300 UTC

Christy has sent in the 0000 UTC and 0300 UTC soundings from the east side site.  Lapse rates below 700 mb definitely steepened during the 3 hour period.  A weak stable layer persists at 700 mb and this is probably keeping somewhat of a lid on the lake band.  On the otherhand, perhaps shallow is good?

East Side 0000 UTC 9 Nov 2010

East Side 0300 UTC 9 Nov 2010

Winds have veered a bit to more NW above 700 mb.  I'm not sure I'll be up for the 0600 UTC sounding, but will post it up if the adrenalin keeps me going.  Wish I didn't need to give a talk in Park City tomorrow night.

SOLPEX IOP2 0410 UTC 9 Nov update

The wind-parallel band is still hanging on (0412 UTC radar image below).  It's not real strong, but it is a persistent rascal.  A weak cell has just initiated just north of it near Hat Island and I'm hoping this is a sign that we'll see some elongation and intensification soon.