862 
FXUS65 KPSR 271146 AAA
AFDPSR

Area Forecast Discussion...Updated
National Weather Service Phoenix AZ
445 AM MST Thu Jun 27 2019

.UPDATE...Updated aviation and fire weather discussions.

&&

.SYNOPSIS... 
A high pressure system centered over New Mexico will continue to be 
a strong influence for weather in Arizona and southeast California 
through next week. This will result in mostly near normal 
temperatures across Arizona to slightly below normal readings 
across southeast California. The dry weather also looks to persist
well into next week for the bulk of the region with high terrain 
showers and thunderstorms relegated to far east central Arizona.

&&

.DISCUSSION...
The subtropical high situated just to our southeast will shift
more into our region beginning Friday leading to warmer conditions
through early next week. Well to our northwest, a deep closed low
will remain nearly stationary through the weekend, keeping the 
subtropical high from completely engulfing the Desert Southwest. 
Stuck between the two upper level systems will result in increased
south to southwesterly flow aloft and continued breezy daytime 
conditions for the bulk of the region. The slight northwestward 
shift in the high will allow for a bump in temperatures starting 
Friday with highs reaching between 106-110 degrees over the 
deserts.

The shift in the subtropical high will also likely open a small
window for some modest low and mid level moisture working into
extreme southeast and east-central Arizona beginning Friday. This
pattern looks to mainly stay the same into at least early next
week, but any shower and thunderstorms should be fairly limited
and remain over high terrain areas. Long range models continue to
show no realistic chance of any monsoonal moisture nearing the 
lower deserts through next week.

Though it will not affect our region to a great degree, models are
still showing the mid and upper level remnants of Tropical Storm
Alvin moving north-northeastward centered over the Lower Colorado
River Valley on Saturday. This will bring a decent slug of 
moisture above 15K feet through the region with the deepest 
moisture likely coming up through southeast California and 
southwest Arizona. The main impact will be mostly cloudy skies 
Friday night and Saturday with high temperatures likely stunted 
somewhat on Saturday, especially west of Phoenix. Some leftover 
clouds on Sunday will likely thin enough to allow temperatures 
to recover with highs Sunday approaching 110 degrees over the 
bulk of the deserts. Slightly above normal temperatures should 
persist through Monday before dropping back to around normal by 
the middle of next as the subtropical high is forecast to weaken 
and shift farther to the southeast.

&&

.AVIATION...Updated at 1145 UTC.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:

Dry southwest flow aloft will keep skies generally clear across the 
greater Phoenix area today into Friday. Winds will follow typical 
diurnal tendencies at the TAF sites; east wind this morning will 
gradually transition to southwest/west by later in the afternoon. 
There will be a couple of minor issues. One is potential for some 
gustiness during afternoon and early evening with gusts into the 
teens possible. Gusts will be mentioned in the TAFs. Second is 
potential for 2-3 hours of southerly flow in the transition period 
between east and west regimes. This will mainly affect Phoenix Sky 
Harbor; do not expect speeds much above 10kt and although a gust or 
two is possible, do not expect significant crosswind conditions.

Southeast California/Southwest Arizona including KIPL and KBLH: 

Dry southwest flow aloft will keep skies generally clear next 24 
hours across the western deserts. Winds should not be overly strong 
but may gust upwards of 20kt at times at KBLH during the afternoon. 
Winds will generally favor the south at KBLH today, and become a 
bit more southwest during the evening. Look for southeast winds at 
KIPL most of the day before turning to the southwest after 4 pm. 
KIPL may also gust into the teens for a few hours into the early 
evening.

Aviation Discussion not updated for amended TAFs.

&&

.FIRE WEATHER...
Saturday through Wednesday: High pressure aloft will keep high 
temperatures a few degrees above seasonal normal through Monday, 
with hotter deserts climbing to around 110 degrees. Otherwise expect 
dry conditions with any thunderstorm confined to high terrain well 
east of Phoenix. Look for cooling to near seasonal normals by 
Tuesday.

Ridge top and gap winds will occasionally be breezy during the 
afternoon hours with SW gusts around 25 mph common. Minimum relative 
humidity values will mostly fall into a 10-15% range with generally 
poor (locally fair) overnight recovery. The winds and humidity 
combined with very dry fuels will frequently result in elevated fire 
weather conditions during this period. 

&&

.SPOTTER INFORMATION STATEMENT... 
Spotter activation is not expected.

&&

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

$$

DISCUSSION...Kuhlman
AVIATION...CB
FIRE WEATHER...MO/Kuhlman/CB