Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 220413
Area Forecast Discussion
National Weather Service Tucson AZ
912 PM MST Fri Apr 21 2017
.SYNOPSIS...Very warm and dry weather will persist into at least
early next week. Occasional high clouds, and gusty afternoon winds
at times will occur as systems brush by to our north. Stronger winds
will be possible especially late next week along with a slight
chance of showers and thunderstorms across the White Mountains.
.DISCUSSION...Clear skies remained over the area late this evening.
Daytime temperatures will peak Sunday as a ridge of pressure shifts
east and weakens in response to a system passing north of the area.
Current forecast appeared to handle these trends well. Please refer
to the additional sections for more details.
.AVIATION...Valid through 23/06Z.
SKC through the period. Sfc wind WLY/NWLY at 10-14 kts with some
gusts to around 25 kts during the afternoon and early evening hours.
Otherwise, sfc wind will be terrain driven at less than 10 kts.
Aviation discussion not updated for TAF amendments.
.FIRE WEATHER...Dry conditions and above average daytime
temperatures will continue into next week. Minimum daytime
humidities will be in the single digits and teens. For the most
part, 20-foot winds will follow normal diurnal trends at less than
15 mph with daily afternoon and early evening gustiness. A few
systems passing north of the region next week may bring breezy to
windy conditions creating critical fire weather conditions
mainly near the NM border and through the Gila River Valley.
.PREV DISCUSSION...Visible satellite imagery and another quick look
out the window indicated continued clear skies across the region
this afternoon. This will generally be the rule through at least
Sunday afternoon as an upper ridge continues to build in from the
west. This ridge will result in a warming trend through the weekend
with high temperatures on Sunday peaking around 8-13 degrees above
average. A very gradual cooling trend (about 2-3 degrees per day)
will occur thereafter through next week as a few systems pass north
of the region. By next Friday, daytime highs should be right around
average or perhaps a degree or two below.
In addition to the slightly more seasonable temperatures, look for
some breezy west or southwest winds each afternoon next week. Speeds
should peak close to advisory level by next Thursday and Friday for
locales mainly south and east of Tucson, as the storm track sinks
further south. This may help foster critical fire weather conditions
as well, with daytime relative humidity bottoming out in the mid-
teens. More information can be found in the fire weather section
Additionally, this system may bring with it enough moisture for a
few showers and perhaps a thunderstorm mainly across the White
Mountains Wednesday night through Friday. As such, have introduced a
slight chance of showers to the forecast for that period, including
a slight chance of thunderstorms during the day Thursday.
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