Scientific Forecaster Discussion
fxus65 ktwc 221010
Area forecast discussion
National Weather Service Tucson Arizona
310 am MST Thu Aug 22 2019
Synopsis...a more active thunderstorm pattern can be anticipate
through this weekend before turning off early next week as high
pressure aloft builds over the area. After temperatures cool to near
or slightly below normal this weekend, temperatures will climb to
well above average once again the first half of next week.
Discussion...latest models continued to advertise a more activate
thunderstorm pattern developing through this coming weekend. Deep
moisture pooled south of the region was progged to spread northward
into Southeast Arizona by late Friday. This increase in moisture
will signal an upswing in daily showers and thunderstorms,
especially on Friday and Saturday. This more active thunderstorm
pattern will be brief, as models showed another dry spell for early
next week along with a return of very hot temperatures. In the
meantime, the increase in moisture and subsequent thunderstorms will
help cool daytime temperatures to near or slightly below normal.
Aviation...valid through 23/12z.
Few-scattered clouds at 10k-14k ft mean sea level west of ktus and scattered-broken clouds
south and east of ktus through the forecast period. Isolated to
scattered thunderstorms and rain/rain showers will develop after 22/19z primarily from
ktus/kols eastward with brief MVFR vsby/cigs possible, particularly
near terrain. Precip decreasing this evening though a few -shra
could linger overnight near the international border including
kdug/kols. Gusty outflow winds are possible near thunderstorms and rain/rain showers up to
around 40 kts. Otherwise, surface wind mainly southwesterly to westerly around 7-14
kts becoming primarily southerly overnight. Aviation discussion not
updated for taf amendments.
Fire weather...mainly afternoon and evening thunderstorm chances
increase starting today to include much of Southeast Arizona and
will continue into the weekend before drier weather returns early
next week. The return of deeper monsoonal moisture will allow
temperatures to fall back to near seasonal levels by Friday which
will remain through the weekend before warmer temperatures return
next week. Any thunderstorms that do develop may produce gusty and
erratic outflow winds. Otherwise, 20-ft winds will generally follow
normal diurnal trends at less than 15 mph.