Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Las Vegas Nevada
217 am PST Friday Dec 6 2013
Synopsis...unseasonable cold weather will continue across the area
through early next week with below freezing temperatures in many
Lower Desert elevations at night. A storm system is expected to move
across the area on Saturday bringing an increasing chance of
precipitation. Snow could be seen as low as 2500 feet in some areas.
Gusty winds are expected across the area Saturday into Saturday
night which could bring additional hard freeze conditions to the
region early next week.
Short term...Friday and Saturday. Models show the next strong
shortwave taking shape off the Pacific northwest coast and is forecast to
dive south along the coast through the day. Little to no impact is
expected across the area until tonight when chances for snow
increase across the Sierra. For today...temperatures will be slow to
warm after a cold morning start with highs topping out close to what
was seen yesterday. Winds for the most part will be light but will
pick up out of the south across the western regions of the area.
The storm system will sink into the area tonight and Saturday
bringing increasing chances of precipitation...first to the Sierra
and northern zones Saturday morning and eventually spreading to much
of the rest of the area Saturday afternoon and evening. The core of
the system is forecast to move across the northern Great Basin with
an associated 150 knots jet providing broad scale lift across central
and southern Nevada and northwest Arizona. Model quantitative precipitation forecast forecasts are
not overly impressive with total amounts ranging from .10 to .30
inches depending on the model. This translates to snow amounts
generally ranging from a dusting in the lower elevations to 3 inches
or so in the higher elevations. Locally greater amounts are possible
where snowfall intensity is enhanced in more organized snow bands.
Not overally convinced the Las Vegas Valley will see accumulating
snow given the time of day when the deepest moisture and best lift
is forecast and quantitative precipitation forecast forecasts of a tenth or less. Regardless...snow
flurries seem reasonable with the arrival of reinforcing cold air.
Temperatures are forecast to warm several degrees Saturday...well
into the 40s in Las Vegas. However...cloud cover could play a big
part in how cold morning temperatures are and how much it warms during the
day. Due to the added cloud cover...hard freeze warnings probably
will not be needed for Saturday.
Long term...Sunday through Thursday...a few snow showers may last
into Sunday morning over northeast Mohave County before the
shortwave exits east. A secondary feature moving south across Utah
Sunday night looks to be dry...but will likely bring with it an
increase in north winds on Monday...especially down the Colorado
River valley. An advisory may need to be considered by later shifts.
For US desert dwellers...Bone chilling temperatures will persist at
least into Wednesday morning with additional hard freeze headlines
likely needed. High temperatures will continue to run about 20
degrees below normal Sunday and Monday...with values about 10
degrees below normal Tuesday and Wednesday. Only slight moderation
in the temperatures is expected by Thursday as winds aloft finally
transition to a westerly direction as a trough approaches the
Pacific northwest coast. Latest models have slowed this system so
did delay the onset of showers until after Thursday afternoon.
Aviation...for McCarran...cold weather with no operationally
significant clouds or winds expected today. Stronger southwest winds
will develop Saturday morning and continue into the afternoon. Gusts
of 25-30kts are possible. There will be a chance of rain and snow on
Saturday which could result in low ceilings...particularly during
the afternoon and early evening.
For the rest of southern Nevada...northwest Arizona...and southeast
California...cold weather with no operationally significant clouds
or winds can be expected today...then a storm system will bring a
chance of rain and low elevation snow Saturday which could result in
a period of low ceilings. Strong southwest winds will develop on
Saturday with the strongest winds in the Sierra and in the vicinity
of kdag where gusts of 40 to 50 kts are possible.
Nevada...Winter Weather Advisory from 10 am to 10 PM PST Saturday for
Hard freeze warning until 9 am PST Friday for
Winter Weather Advisory from 4 am to 10 PM PST Saturday for
Arizona...Winter Weather Advisory from 11 am to 11 PM MST Saturday for
Hard freeze warning until 10 am MST Friday for azz003-036.
Freeze warning from 1 am to 10 am MST Friday for azz002.
California...hard freeze warning until 9 am PST Friday for caz522>526.
Freeze warning from midnight tonight to 9 am PST Friday for
High wind watch from Saturday morning through Saturday evening
For more forecast information...see US on our webpage:
Http://weather.Gov/lasvegas or follow US on facebook and twitter