185
FXUS65 KTWC 091013
AFDTWC
Area Forecast Discussion
National Weather Service Tucson AZ
313 AM MST Tue Jun 9 2026
.SYNOPSIS...
High temperatures will be 2 to 7 degrees above normal today and
Wednesday, remaining just above normal through the second half
of the week. Breezy conditions are expected each afternoon. Increasing
moisture may start to bring slight chances for showers and
thunderstorms by the end of the week through the weekend.
&&
.DISCUSSION...
An upper level trough crossing the Pacific Northwest, Great
Basin, and then Northern Rockies today will extend south into
the desert southwest, while a weak circulation will become
separated from the main trough and sit just off the western Baja
coast. The strongest upper level winds from this trough remain
well to the north however this persisting trough will still
drive afternoon breezes over the next several days southeastern
Arizona. Early this morning, southerly flow from the
aforementioned synoptic setup was pulling in a stream of mid-
level moisture over southeastern Arizona, producing widespread
clouds and a few lightning strikes mainly from Cochise through
Graham and Greenlee counties. The synoptic forcing for this
activity will wane through the morning with this activity
shifting off to the east.
Today, modest mid-level height rises will bring high
temperatures up 2 to 4 degrees from yesterday, producing areas
of moderate HeatRisk across lower elevation areas along and east
of a Tucson-Nogales line. A westward shifting subtropical ridge
will bring temperatures up a few more degrees on Wednesday.
The incoming subtropical ridge will also turn mean winds
southerly and bring an increase in atmospheric moisture to the
region through the second half of the week. Mean precipitable
water values from the 00Z ensemble suite range from 1-1.3
inches by this weekend with surface dew points creeping up over
45-50 degrees. Where models have struggled is how to resolve
the shower/thunderstorm potential with this moisture initially
arriving in mainly the mid to upper levels. While the moisture
content maximizes this weekend, it wouldn`t be surprising to see
isolated activity as early as Thursday especially across
southern locations. From the end of the work week into early
next week the daily forecast chances (15-35 percent) are mainly
tied to areas near terrain especially near the International
Border and the White Mountains, with currently low but non-zero
chances elsewhere. Convective chances will evolve day to day
depending on the previous day`s previous activity.
&&
.AVIATION...Valid through 10/12Z.
SCT-BKN ceilings 8k-12k feet main from KTUS-KOLS east will give
way to mainly clear skies by the late morning. Mainly virga with
these clouds with a very isolated chance of lightning. Surface
winds become southwesterly 10-15 kts with gusts to 20 kts after
09/18Z. Aviation discussion not updated for
TAF amendments.
&&
.FIRE WEATHER...
Winds today will remain southwesterly 12-18 mph with gusts to
25-30 mph, with a shift to the west tomorrow and northwest
Thursday. Minimum relative humidity values generally 8-14
percent with an increase in moisture Thursday through the
weekend. This moisture will begin to introduce chances for
showers and thunderstorms with gusty outflow winds and lightning
as early as Thursday, though with better chances (generally
15-35 percent) Friday into early next week.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Edwards
AVIATION...Edwards
FIRE WEATHER...Edwards
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