Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 222349

Area Forecast Discussion
National Weather Service Grand Junction CO
549 PM MDT Tue May 22 2018

.SHORT TERM...(Tonight through Wednesday night)
Issued at 216 PM MDT Tue May 22 2018

Relatively moist air, for this time of year, an 80kt upper level
jet moving north along the UT/CO border, and a 500mb thermal
trough region all rotating around an upper level low over
southeast NV this afternoon resulted in rapid development of
showers and thunderstorms. A couple of storms early on produced
small hail up to dime size and winds gusting around 50 mph.
However, current trends indicate too much convective inhibition as
a result of expanding and merging anvil cirrus prohibiting
boundary layer destabilization. So, while showers and storms will
continue to move north over the region this afternoon, it appears
the chance of severe storms is quite low.

Otherwise, forcing and moisture for this widespread precipitation
will move north out of the area this evening. The parent upper
level low will also lift north through Wednesday and drier air
moves back in over our region in its wake. Isolated showers or
storms are possible Wed afternoon over the higher terrain mainly
near the Divide. Temperatures will rebound several degrees from
today`s highs.

.LONG TERM...(Thursday through Tuesday)
Issued at 216 PM MDT Tue May 22 2018

An upper level ridge will build over the area Thursday and Friday
ahead of the next deep upper level low rolling toward California.
Dry and warm weather will occur under this ridge with highs 6-12
degrees above normal - into the lower 90s Friday for lower
valleys. There is good model agreement with the upper level low
tracking east to a position near where the current one is located
over southeast NV by Sunday morning. With the pressure gradient
tightening ahead of the low Saturday, expect windier conditions
Saturday afternoon. This combined with dry and warm air in place will
result in heightened fire behavior concerns and may require fire
weather hazard highlights.

The forecast beyond Saturday is lower confidence. The upper level
low may end up wobbling around over the Great Basin to end the
Memorial Day weekend. Depending on its eventual path, eastern
UT/western CO will see more or less shower activity and
potentially cooler temperatures. For now the forecast will remain
dry save small chances of showers over the higher terrain, and
will put temperatures at or slightly above normal.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 549 PM MDT Tue May 22 2018

Drier air invading from the southwest is gradually eroding the
lower cigs and shower activity over E.Utah and W.Colorado. The
threat of some gusty winds and light rain will persist through
23/02Z. Otherwise VFR conditions should prevail across the region
over the next 24 hours with a lesser coverage of clouds and
showery precipitation on Wednesday.




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