450 
FXUS65 KFGZ 192158
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
258 PM MST Sun Jul 19 2020

.SYNOPSIS...For today, expect a downturn in shower and
thunderstorm activity, with only isolated storms forecast over
higher terrain. In addition, today will be warm, and an Excessive
Heat Warning is in effect for the Grand Canyon through Monday
evening. Slightly greater storm activity is expected on Monday,
with the potential for more robust monsoon conditions from Tuesday
onward.

&&

.DISCUSSION...Scattered to isolated showers continue across the
area with most activity producing only light amounts of rainfall.
Most of the activity will continue to sunset then diminish as
diurnal convection ends. Storm activity on monday is expected to
be similar to today with limited moisture, and a capping 
inversion associated with high pressure aloft limiting convection.


On Tuesday upper level support is going to move into the region
from California as a weak upper level low transits the area. This
should provide for some upper level support, along with more
southerly low level flow that could bring more moisture into the
region. All of this seems to set up the potential for more
widespread storms. 

Timing of the low will be crucial, but some models are hinting at
some shear possible of organizing storms that do develop into 
longer lasting and stronger thunderstorms than are typical to late
July monsoonal pattern. 

Moisture is expected to increase through the week as southerly
flow is expected to bring more and more moisture into northern
Arizona. This is most noticeable in increasing chances of
precipitation as week progresses. 

Another low pressure system moves past the area on Thursday and 
while timing and location are still well outside of any high 
confidence solution, potential does exist for increased 
organization of storms again on Thursday. Again this isn't exactly
the typical monsoonal pastern, more akin to a late summer flow 
regime with low pressure systems coming this far south. 


 
&&

.AVIATION...For the 12Z package...Look for VFR conditions over the 
next 24 hours. Isolated showers and thunderstorms developing mainly 
over the higher by late morning then lasting into the early evening. 
Surface winds generally light, except near any storms. Aviation 
discussion not updated for amendments.

&&

.FIRE WEATHER...Expect isolated to scattered thunderstorms across 
the area again today and Monday, with the best chances for wetting 
rainfall located over the higher terrain of the White Mountains and 
Mogollon Rim. The primary hazards will be lightning and gusty 
outflow winds. 

Tuesday through Thursday...Shower and thunderstorm chances will 
continue each afternoon, with increasing moisture and an uptick in 
activity starting Tuesday, increasing each day.    

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Excessive Heat Warning until 8 PM MST Monday FOR AZZ006.


&&

$$

PUBLIC...Suk
AVIATION...Suk
FIRE WEATHER...Suk


For Northern Arizona weather information visit
weather.gov/flagstaff