National Weather Service Forecast Discussion

Dicussion provided by the National Weather Service Forecast Office located in San Diego, California

FXUS66 KSGX 170354

Area Forecast Discussion
National Weather Service San Diego CA
854 PM PDT Tue Aug 16 2022

There will be fluctuations during the next week in monsoonal
moisture and chances for afternoon and early evening thunderstorms
in the mountains and deserts. It will be slightly drier with
only isolated thunderstorms for Wednesday and Thursday. Then
increasing moisture for Friday and Saturday with greater chances
for thunderstorms and inland high temperatures not as hot. Then a
drying trend for Sunday and Monday with warmer high temperatures
for inland areas early next week as the drying occurs.




It was another rather active monsoon thunderstorm day over the
mountains and high desert. That activity has since dissipated and
a tranquil night is expected. No changes were needed to the
forecast this evening. See previous discussion below for forecast

Previous Discussion:

.SHORT TERM...(Today through Thursday)...
Convection has started to grow and become more widespread over the
mountains, especially near the Big Bear area. These showers and
storms will continue to produce locally heavy rainfall and gusty
winds through the early evening. The marine layer will continue to
be shallow and will bring some cloudy conditions near the coast
this evening into tomorrow morning. Wednesday and Thursday still
look to be slightly drier with PWAT values lowering a bit from
today. Will continue a slight chance of thunderstorms across the
mountain areas during Wednesday and Thursday afternoons as the
monsoonal flow pattern weakens. High temperatures are currently
right near the century mark this afternoon. We will see similar
temperatures for tomorrow, with a slight decrease in temperatures
for Thursday.


.LONG TERM...(Friday into early next week)...
Another surge of monsoonal moisture is expected Friday into
Saturday per latest long-range models. This will lead to a higher
chance of scattered thunderstorms across the mountains and
deserts. Some storms may even drift west for areas of the Inland
Empire and San Diego County on Saturday. Drying is expected by
Sunday into early next week. Temperatures will slowly take a
downward trend by the end of the week, though humid days will


170330Z...Coast/Valleys...Patchy low clouds with bases 700-1000 ft
will fill in along the coast through 09Z, spreading 10-15 mi inland
through 13Z. Areas of vis 3-5 sm, locally 1 sm or less on higher
coastal terrain including near KCRQ. Clouds and vis restrictions
clearing 14-17Z. Low clouds will redevelop after 18/02Z with bases
closer to 800-1200 ft MSL. Otherwise FEW clouds at/above 10,000 ft
MSL and unrestricted vis through Wednesday evening.

Mountains/Deserts...ISOLD SHRA/TSRA developing over the mountains
after 19Z Wed with CB bases 10,000 feet MSL and tops 35,000 feet.
Gusty and erratic winds and brief heavy rain vcnty TSRA. SHRA/TSRA
dissipating by 18/03Z. Otherwise FEW-SCT clouds at/above 10,000 ft
MSL and unrestricted vis through Wednesday evening.


No hazardous marine weather through Friday. There is a slight chance
of thunderstorms over the coastal waters on Saturday, but confidence
is low.


CA...Heat Advisory until 8 PM PDT Wednesday for San Bernardino and
     Riverside County Valleys-The Inland Empire.




PUBLIC...Gregoria (Update)/APR (Previous Discussion)

NWS SGX Office Area Forecast Discussion