FXUS65 KTWC 190929
Area Forecast Discussion
National Weather Service Tucson AZ
229 AM MST Tue Oct 19 2021
.SYNOPSIS...After another chilly morning or two, high pressure
will bring a strong warming trend the second half of the week with
dry conditions through the weekend. Another system will bring
gusty winds and cooler temperatures early next week.
.DISCUSSION...The frontal boundary associated with the low pushing
through Utah is near central Arizona as southern portions upstream
of our area begin to lose definition and wash out. We may not have
a clear FROPA later this morning, but drier air associated with
the cooler airmass should start to filter in later today into
Wednesday. Until then, surface dew points are up 15 to 20 degrees
over the past 24 hours. Otherwise, no surprises as we see any
precipitation well north of our area.
The broad high will rebound through the intermountain west over
the next 72 hours, with temperatures climbing back to a few
degrees above average by Thursday.
As mentioned previously, the mean trough position west of British
Columbia continues to strengthen with plenty of reinforcing energy
upstream. This segues nicely into the pattern change suggested by
ensembles for the last week of the month. That should get things
going in much of the west as a broad and strong split develops
down through the west coast, with model trends deepening in
general. Most of the winter weather action will be north of us,
however much cooler temperatures are looking more likely the last
few days of the month. Considering the impressive moisture fetch,
don`t rule out a few showers for us either.
.AVIATION...Valid through 20/12Z.
FEW-SCT clouds 6-8kft AGL. SFC winds southwesterly 6-10kts with
occasional gusts around 18kts this morning, diminishing later.
Aviation not updated for TAF amendments.
.FIRE WEATHER...A quiet and dry period of weather is expected
through the week as high pressure brings another warming trend.
20-foot winds will be less than 15 kts the rest of the week, with
some gustiness early next week as another system passes north of
us. Expect seasonal humidity levels in the teens to lower 20s for
afternoon Min RHs and good overnight recoveries (generally
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