992 
FXUS65 KPSR 151132 AAA
AFDPSR

Area Forecast Discussion...Updated
National Weather Service Phoenix AZ
430 AM MST Sun Nov 15 2020

.UPDATE...Updated aviation discussion.

&&

.SYNOPSIS... 
Dry conditions will continue into at least the middle of the week
as temperatures steadily warm back above normal. Readings will 
likely be nearing record territory by the early to middle part of 
the week with afternoon highs pushing close to 90 degrees in 
lower elevation communities. Some cooling is possible during the 
late portion of the week as an area of low pressure aloft starts 
to approach from the west.

&&

.DISCUSSION... 
Early morning objective analysis showed dry northwesterly flow aloft 
over the Desert Southwest promoting clear skies across the region. 
Temperatures across the lower deserts this morning have cooled off 
into the low to mid 50s so far and will continue to cool into the 
upper 40s to low 50s. We'll see a warmer day today as high pressure 
builds into the region, allowing for temperatures to climb above 
normal once again. Lower desert highs this afternoon are expected to 
top out in the lower 80s. Skies are expected to remain clear as dry 
northwesterly flow aloft persists ahead of the building ridge.

Confidence remains high around the idea of a strong upper level 
ridge building across the western CONUS over the next several days, 
leading to well above normal temperatures during the first half of 
the week. Operational and ensemble guidance continue to show 500 mb 
heights climbing upwards of 586-589 dm by Tuesday as the axis of the 
ridge moves through the region. ECMWF ENS guidance shows 500 mb 
heights and 850 mb temperatures near or above the 99th 
climatological percentile across a good portion of Arizona Monday 
into Tuesday as the ridge shifts across the Desert Southwest. The 
result will be temperatures running upwards of 10-15 degrees above 
normal during the first half of the week as highs reach the upper 
80s across lower elevation locations. Daily record highs will be in 
jeopardy during this time. If we were to overachieve on our high 
temperature in Phoenix on one of these days and reach 90 degrees, 
this would set a new record for the latest 90+ degree day (11/15 
back in 1999). Temperatures begin to very gradually cool after 
Tuesday as the strong upper level ridge shifts east of the region. 

Heading into this weekend, guidance continues to show a shortwave 
trough moving through the Southwest. The trough is expected to bring 
cooler temperatures with temperatures returning closer to seasonal 
normals. The GFS continues to be aggressive with bringing an influx 
of moisture ahead of the trough, which would bring a potential 
chance for rain to the state. However, ensemble guidance isn't as 
supportive of this idea with only a few EPS and GEFS members showing 
measurable precipitation in the lower deserts. For now, PoPs remain 
low (< 10%) across the CWA this weekend with an increase in cloud 
cover as the currently expected outcome. 

&&

.AVIATION...Updated at 1130Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT.. 
Southeast California/Southwest Arizona including KIPL and KBLH: 

High pressure aloft building over the area will lead to generally 
light winds and clear skies across the various terminals during the 
next TAF period. In the Phoenix area, speeds generally below 6kt 
with directions favoring the east over the next 24 hour. Typical 
diurnal trends not really expected as winds will be more 
light/variable than west after 21z this afternoon before the east 
winds set in again after 05z this evening. Out west look for lots of 
light variable winds, weakly favoring west at times at KIPL and the 
north/northeast at KBLH. No aviation concerns for at least the next 
24 hours.

&&

.FIRE WEATHER... 
Tuesday through Saturday:
There are no significant changes to the forecast...Unusually warm
and near record breaking temperatures will continue through
Thursday across the entire region. Dry weather will also persist
with afternoon humidity levels generally falling into a 10-30%
range, while overnight recoveries only rebound towards a 25-50% 
range. While some locally enhanced wind gusts are likely around 
terrain features at times, for the majority of the period winds 
will be fairly light including the typical daytime 
upslope/nighttime drainage directions. 

&&

.CLIMATE...

Record highs next week:

 Date     Phoenix        Yuma        El Centro
 ----     -------        ----        ---------
Nov 16   89 in 1999    91 in 1990    89 in 2017
Nov 17   87 in 2008    89 in 2019    88 in 2019
Nov 18   88 in 2008    88 in 2008    90 in 1936
Nov 19   88 in 2007    88 in 2008    90 in 2008

&&

.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

DISCUSSION...Smith
AVIATION...CB
FIRE WEATHER...MO/AD/Smith 
CLIMATE...MO