Marine Weather and Tide Forecast for Douglas, AZ

DISCUSSION
It'a beautiful day across the CWA with temperatures 10-12 degrees below normal and sunny to partly cloudy skies. Aloft, a closed low is moving through the Four Corners region and an east-west oriented ridge is building into the upper Great Basin and Pacific Northwest. The closed low will be absorbed by a trough moving in from Canada by Friday and the ridge will build into western Wyoming and Colorado pinching off a closed low that will sit over southern California and northern Baja. At the same time a very strong surface high forms just east of the Rockies centered over Wyoming and gradually moves south Friday into Saturday. This surface high will be very strong with NAEFS mean MSLP 3 standard deviations above average. This will create a very strong pressure gradient over southeast Arizona leading to a long-duration easterly wind event Thursday night into Saturday.

NAEFS mean 850 mb wind speeds are 40-50 kts late Thursday night into Friday night, which is 4-6 standard deviations above normal. Expect surface winds starting around 16/06Z through Saturday afternoon to be 30-45 mph with gusts 50-70 mph. Models show the strongest winds in the lee of Sky Islands, likely enhanced by mountain waves and downsloping. Thanks to the position of the closed low over Baja 700-500 mb winds will be out of the southeast, so momentum transfer down to the surface will have a similar direction to the surface, which is not typical for east wind events. Also, to drive home how anomalous this is the Euro EFI is at 0.95-1.0 for most of southeast Arizona Friday. REFS wind gust probabilities for 60 mph or greater Friday are 30-90 percent for a good portion of southeast Arizona with the highest probabilities in the lee of the mountains and east-west oriented valleys.

Based on model guidance and growing confidence in how anomalous this event will be the Wind Advisory has been upgraded to a High Wind Warning from 11 PM Thursday through 11 PM Friday from central Pima County eastward. A Wind Advisory will then be in effect from 11 PM Friday through Saturday afternoon. The Tohono O'odham Nation has also been added to the Wind Advisory starting early Friday morning. In the High Wind Warning area expect sustained speeds 35-45 mph with gusts 55-70 mph. Best timing for the strongest winds looks to be Friday morning and early afternoon. These winds could lead to downed trees and power poles as well as blowing dust. High profile vehicles should also use caution when driving in cross winds.

In the tropics Hurricane Simon is 250 miles south southeast of Cabo and will weaken and move northwestward over southern Baja this weekend into early next week. This will send moisture into southern Arizona leading to a chance for showers and thunderstorms Friday into Saturday. Initially best chances will be west of Tucson then cover most of southeast Arizona Saturday.
Sunday will likely see a brief break in rain chances, but the upper air pattern stays fairly progressive. By Sunday the closed low over Baja opens up and flattens out as a Pacific low approaches the Northwest and then moves down the west coast early to mid next week. This will lead to continued below normal temperatures and 20-40 PoPs.

AVIATION
Valid through 16/00Z.
FEW-SCT clouds 3-6k ft AGL south and east of Tucson this afternoon and evening then SKC thereafter. SFC winds will be WLY/NWLY 5-10 kts this afternoon and early evening then less than 8 kts and terrain driven overnight. Thursday morning through the end of the TAF period winds will be SELY 5-10 kts.
Aviation discussion not updated for TAF amendments.

FIRE WEATHER
Temperatures will remain below normal through this weekend. A strong surface high pressure area will move into Southeast Arizona from the east Thursday night resulting in strong east to southeast winds late Thursday night into Saturday.
This wind event has the potential to produce very strong easterly winds. Locations on the lee-side of the higher terrain, terrain gaps, and east-to-west oriented valleys will also be susceptible to the strongest winds Friday morning. For these areas expect speeds 35-45 mph with gusts 55-70 mph Friday morning into the evening, then 25-35 mph with gusts 50-60 mph Friday night into Saturday. Minimum relative humidity remains above 25-40 percent through the weekend. There will also be 20-50 percent chance of showers and thunderstorms Friday and Saturday.

TWC WATCHES/WARNINGS/ADVISORIES
High Wind Warning from 11 PM Thursday to 11 PM MST Friday for AZZ503>509-511>514.
Wind Advisory from 2 AM Friday to 2 PM MST Saturday for AZZ502- 515.
Wind Advisory from 11 PM Friday to 2 PM MST Saturday for AZZ503>509-511>514.