000
FXUS65 KTWC 190955
AFDTWC
Area Forecast Discussion
National Weather Service Tucson AZ
255 AM MST Tue Mar 19 2024
.SYNOPSIS...An upper level low over Arizona will continue to
impact southeast Arizona. Precipitation chances shift today and
Wednesday into the higher terrain of Graham and Greenlee County
with dry conditions elsewhere. Dry and warmer area-wide Thursday
through Saturday, then another storm system by Sunday into early
next week with cooler temperatures, gusty winds and precipitation
chances.
&&
.DISCUSSION...Water vapor imagery this morning showed the cut-off
low, which has been spinning across the desert southwest since
last Thursday, has split with original low over SE CA and a new
one developing over nrn AZ near Flagstaff. Overall the trend for
today will be a gradual movement to the east of the cut-off low
with best chances for precipitation (10% to 30%) being NE of
Tucson across mainly the northern parts of Graham and Greenlee
counties. Models suggest the center of the cut-off low over east-
central Arizona later tonight then we say farewell/sayonara on
Wednesday as it moves into New Mexico. A few snow showers across
the Whites Wednesday on the back side of this system. Temperatures
will remain near seasonal normals for most locales today and
Wednesday.
Ridging over the area to end the work week and the first half of
the weekend resulting in warmer high temperatures, with low 80s
for the lower deserts.
Next Pacific system will bring a chance of precipitation to the
area on Sunday and Monday along with cooler temperatures and gusty
winds. Current NBM PoPs for Sunday/Monday, at this time, appear to
be a bit low. Stay tuned.
&&
.AVIATION...Valid through 20/12Z.
FEW-SCT clouds at 7k-10k ft AGL for most of the forecast area thru
the valid period, with SCT-BKN clouds at 6k-9k ft AGL northeast of
KSAD. Slight chance of -SHRA/-TSRA mainly northeast of KSAD thru the
period. SFC wind less than 12 kts and variable in direction thru
19/17Z and again aft 20/03Z. SFC wind between 19/17Z and 20/03Z
WLY/NWLY at 10-18 kts and gusts to 20-28 kts, with the strongest SFC
wind to the east of KTUS. Aviation discussion not updated for TAF
amendments.
&&
.FIRE WEATHER...Dry conditions are expected across most of
southeast Arizona through Saturday, with a slight chance of showers
and thunderstorms mainly in the White Mountains today and Wednesday.
High temperatures will be within a couple of degrees of normal
through Thursday, warming to 4-7 degrees above normal Friday and
Saturday, then falling back below normal Sunday into early next
week. Breezy west to northwest 20-foot winds at 15-20 mph and some
gusts to around 30 mph will occur east of Tucson this afternoon,
with 20-foot winds less than 15 mph and diurnal in nature Wednesday
through Saturday. Minimum RHs will generally be in the 15-25 percent
range in the valleys through Wednesday, lowering to 8-15 percent
Friday and Saturday. A storm system is then forecasted to move into
the region Sunday into early next week, resulting in gusty winds,
cooler temperatures and a chance of precipitation.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
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NWS TWC Office Area Forecast Discussion