FXUS65 KVEF 182132

Area Forecast Discussion
National Weather Service Las Vegas NV
232 PM PDT Mon Mar 18 2019

A warm and dry pattern continues for the next 24 hours but a
change to more unsettled pattern consisting of mountain snow and
scattered showers will persist through the rest of the weekend and
into the weekend. Forecast becomes more dry by the late weekend
and early next week.


.DISCUSSION...Today through early next week.
The warm and dry pattern we have been enjoying will see some
changes over the course of the week as our current ridging pattern
pushes east ahead of a negatively tilted shortwave that will come
on shore mid-week and linger through the rest of the week.

While the aforementioned negative tilting raises eyebrows, upper
level wind speeds aren't overly impressive. This looks like it
will result in a situation where much of the CWA is under
favorable diffluent flow, enough to bring in scattered to even
widespread shower activity, but not enough to result in any one
period of significant impact. This system appears to lack a deep
moisture tap and favorable 850 mb flow to result in much heavy
rain but enough mid to upper level moisture to result in some
occasionally moderate rain rates off and on throughout. Perhaps
the best chance for this would be Wednesday afternoon when
forecast soundings show the best moisture profile above 600 mb and
best opportunity of 50 kt UL flow. Might also be the best
opportunity for a few rumbles of thunder as meager instability
looks to be available Wednesday afternoon as well.

As far as mountain snow is concerned, there was a slight downtrend
in amounts depicted in the NBM and associated model suite that
contributes to it. At current, the 48 hour amounts between
Wednesday 12Z and Friday 12Z are up to 8 inches for elevations up
to 9000 ft in the eastern Sierra and a few inches more above
that. Spring Mountains look to stay below 6 inches during that
same time period. With no real clear signal for heavy snow at any
one time period, do not feel confident that impacts would be
enough for an advisory at this time. This may change if model
trends increase a bit, but the trend looks to be in the other
direction at current.

As this low begins to shift east Friday, a brief lull in PoP
chances before one more progressive shortwave glances the region
and brings some low end PoP chances favoring the northern
zones. Ridging looks to build by the late weekend and early next
week removing all PoPs from the region.


.AVIATION...For McCarran...Light winds following diurnal trends
will be in place through tomorrow afternoon with speeds generally
below 8 kts. Some passing FEW-SCT aoa 10 kft will continue through
today with increasing coverage expected tomorrow.

For the rest of southern Nevada, northwest Arizona and
southeast California...Light winds following diurnal trends will be
in place through tomorrow morning across the region. An approaching
weather system will bring breezy southerly winds across the region
tomorrow afternoon. Some passing FEW-SCT aoa 10 kft will continue
through today with increasing coverage from west to east expected
through tomorrow.


.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating




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