Marine Weather and Tide Forecast for South Tucson, AZ

DISCUSSION
Water vapor imagery and objective analysis this afternoon shows long-wave, positively tilted troffing across the Southwest CONUS. A compact closed low is also seen retrograding off the SoCal coast, cutting under an amplifying ridge. Dry west to northwest flow has kept skies mostly clear across Southeast AZ, and this combined with the troffing has helped with the unseasonably cold temperatures. A Freeze Warning will be in effect again for Tuesday morning, through 9 AM MST, with widespread subfreezing temperatures across the lower elevation communities, including the Tucson Metro. Remember to continue to take action to protect people, pets, pipes, and plants from prolonged exposure to subfreezing temperatures.

As the closed low continues to retrograde over the Pacific and the primary long-wave trough pulls away, this will allow heights to rise over the area and a brief warming trend through Thursday.
There will even be a chance of reaching or exceeding 70F in Tucson Wednesday, and a better chance on Thursday (60%). Although warming, the mornings will remain cold, with most lower deserts continuing to fall into the 30s each day.

By the second half of the week the retrograded low is expected to open up and work back east into the mean synoptic flow. This already dry low looks like it will struggle to pull much moisture into the region, despite its residence time over the Pacific. GEFS and ENS means mostly show a maintenance of neutral to negative PWAT anomalies through the end of the week, with the exception of perhaps a slight tilt toward above normal PWATs for areas east of Pima and Pinal counties and up into the White Mtns. Perhaps some upper-level divergence from a strong jet streak on the south/southeast side of the opening low can help drive some light precipitation Thursday night into Friday, but the limited moisture will keep PoPs on the low side. PoPs will be highest in the White Mtns area, around 20-30%, and drops to around 10% or lower for much of the rest of Southeast AZ. This system will also result in temperatures cooling down again heading into the weekend. A reinforcing shot of colder air will also arrive with another progressive positively-tilted trough clipping through the region this weekend. This second system also looks to have very limited moisture, given its inland trajectory,thus there are only slight PoPs (10-25%) at this time. Both of these next two systems will also bring widespread breezy conditions, but nothing out of the ordinary with the latest forecast.

AVIATION
Valid through 15/00Z.
FEW cirrus clouds AOA 20k ft are currently spreading in from the SW, but will likely clear by sunrise tomorrow. SFC winds mainly less than 10 kts and generally ELY/SELY overnight into the morning and WLY/NWLY during the afternoon/early evening hours tomorrow.
Aviation discussion not updated for TAF amendments.

FIRE WEATHER
Expect widespread sub-freezing temperatures across Southeast Arizona each morning through Tuesday. Winds will be terrain driven less than 15 mph through Tuesday. Tuesday into Thursday winds turn easterly with speeds up to 15 mph, especially in the Gila River Valley. A passing weather system will then lead to breezy westerly winds Friday into the weekend along with slight precip chances (10-30%). Min RH values will be between 10-20 percent through most of this week and this weekend in the valleys and up to around 30 percent in the mountains.



TWC WATCHES/WARNINGS/ADVISORIES
Freeze Warning from midnight tonight to 9 AM MST Tuesday for AZZ501-502-504>506.