Scientific Forecaster Discussion
fxus65 kpsr 201206
Area forecast discussion
National Weather Service Phoenix Arizona
506 am MST Thu Jun 20 2019
Update...updated aviation discussion
a weak weather disturbance slowly passing by to our north through
Saturday will bring breezy conditions and a slight cool down into
the weekend. This will result in below normal temperatures and
highs mostly in the upper 90s to around 100 degrees this weekend.
High pressure will slowly build across the region next week
leading to temperatures warming back to around normal readings
while dry conditions prevail.
the overall quiet weather conditions look to continue well into
next week with elevated fire danger being the only forecast
concern. Current analysis shows weak flow aloft, but this will
change later today as a deep trough sags southward through the
Pacific northwest. This trough will increase winds aloft enough
later today to lead to widespread afternoon breezy conditions to
locally windy across southeast California. Temperatures today will
be nearly identical to the last couple days, but as the trough
drifts closer to our region Friday into Saturday, highs will bottom
out in the upper 90s on Saturday. Daytime breezy to locally windy
conditions will last through Saturday with winds being slightly
higher Friday. Fire weather conditions will be the main concern
through Saturday due to the winds and continued low rhs.
The trough is forecast to eventually shift to the east on Sunday
leaving mostly dry zonal flow over our region through Monday.
Another deep Pacific trough will set up across the northwest U.S.
By next Tuesday and Wednesday, turning our flow out of the
southwest and likely leading to another round of breezy
conditions. Heights aloft do gradually creep upward next week,
pushing temperatures back to around normal readings during the
latter half of next week. Though models have backed off some on
bringing a strong subtropical high into our region late next week
into the following weekend, it still looks possible highs will
approach 110 degrees across the southern Arizona deserts. There
are also signs sufficient moisture may seep into far eastern
Arizona for some shower or thunderstorm activity beginning late
Aviation...updated at 1200 UTC.
South-central Arizona including kphx, kiwa, ksdl, and kdvt;
Light winds favoring the east-southeast this morning will
steadily transition to several hours of southerly Crosswinds near
6-10kt from late morning into early afternoon. Periodically
breezy westerly winds with gusts of 17-22 kt winds will then
prevail into the mid evening hours as low pressure develops to the
north. Otherwise skies will remain clear to mostly clear.
Southeast California/southwest Arizona including kipl and kblh:
Very breezy southerly and westerly winds will spread from west to
east across the region today as a low pressure develops to the
north. At kipl, light to moderate winds favoring the southeast to
south will switch to the west/southwest by early to mid afternoon
with gusts up to 27-30 kt. At kblh gusty winds favoring the south
by mid morning and the southwest by late afternoon will steadily
increase with some gusts up to 32 kt by late afternoon. Winds
should taper off and return to the south late tonight at kblh.
Skies will remain clear through the period.
Aviation discussion not updated for amended tafs.
Saturday through wednesday:
cooler temperatures through this weekend will eventually give way
to a steady warmup to near seasonal temperatures next week.
Daytime humidity values will still remain near 10% each afternoon
with overnight recovery into the 20-30% range. Gusty winds will
remain a concern through Sunday, especially across the tonto nf
and rim area, with gusts upwards of 20 mph before calming
slightly through the week.
Spotter information statement...
spotter activation is not expected.
California...Wind Advisory from 4 PM this afternoon to 2 am PDT Saturday for
Wind Advisory from 4 PM this afternoon to 11 PM PDT this evening