OD Nats 2013 Day 2 Weather

Radar showing precip to the south of Provo already near Nephi moving into the area, with larger rain event further south in southern Utah. This is moving north, although slowly. Radar also shows precip to the NE past Ogden, which means using a northern launch for the day is not a good option given it's already under inclement weather. So what do the NWS folks have to say?

Forecast discussion is helpful with mention of all the ingredients that we wish were not present.

Area forecast discussion 
National Weather Service Salt Lake City Utah 
245 am MDT Monday Aug 26 2013 


Synopsis...the deep layer moisture plume across Utah will remain 
in place into the middle of the week. Widespread precipitation is 
expected with heavy rain possible across mainly the southern half 
of the state through tonight. 


&& 


Discussion...water vapor loop shows the remnants of Ivo spilling 
northward into the region between a ridge over the central Continental U.S. And 
a trough off the Pacific coast. Acars 400-250mb wind observations 
place a 75-115kt southwesterly jet from Southern California into the 
western Great Basin and northern rockies. Rap...GOES...GPS 
sensors...and 00z slc radiosonde observation indicate precipitable water values range 
from 0.75" across the north to 1.50" across the south and east. 


Flood Watch remains in effect today and may need to be extended in 
length by the next shift. The combination of moisture from Ivo and 
dynanmical lift due to the right entrance region of the jet will 
continue to support locally heavy rainfall in the watch area. 


Raised probability of precipitation mainly across the south and east through tonight. The 
jet will serve as a strong delineation between locations favored for 
rainfall (south and east) vs. Locations hoping to see isolated 
convection (northwest). This setup will continue to support cloudy 
and cool conditions. 


As the central Continental U.S. Ridge tries to build westward beginning 
Tuesday...moisture and weakening disturbances from Ivo will track 
further to the west. Drying and warming will take place...though 
enough moisture will remain in place to support more traditional 
diurnal convection more likely to initiate on the higher terrain. 


Global models indicate a series of disturbances with origins over 
the Gulf of Mexico will round the broad central Continental U.S. Ridge and 
impact the Great Basin next weekend. Temperatures should cool as the 
western extent of the ridge is eroded by these disturbances and more 
expansive convection takes place. Not buying off on the drying 
offered by the GFS solution beyond next weekend. 

Winds aloft are still reasonably light from the southwest, with winds at 12,000 ft forecast to be SSW at 11 knots, lightening to 9 knots by mid day. Winds at 18K are a bit stronger at about 20 kts.

Considerable cloud cover is already in place this morning and this will continue to increase throughout the day. There is clearly drier air to the NW of our region, but this is not expected to move into the SLC valley.

Not much rain is expected to hit SLC proper over the next 12 hours, with the NDFD grids indicating .01 inches trace amounts, but extensive cloud cover is enough to dampen any useful convective potential for soaring. There is a chance of scattered TS but these are likely going to be driven by other forces than surface heating. Where lift would be usable, I suspect one would not want to be in that location in the paraglider!

Today is a great day to do lots of things in Utah, but flying XC is likely not one of them. There doesn't seem to be much reason to explore the day's forecast in any more detail, unfortunately.

Update: quick shot of visible 1km satellite image over the region. Note the NW is slowly getting more moisture as this beasty pumps from the south.

-CG