Marine Weather and Tide Forecast for Willcox, AZ

KEY MESSAGES

A winter weather system moving through the Desert Southwest tomorrow will result in widespread valley rain and mountain snow showers across Southeast Arizona tomorrow and tomorrow night.
Isolated thunderstorms will be possible tomorrow afternoon and evening.

1) Rainfall Rates...with this system will generally be light-to- moderate in intensity. However, pockets of moderate-to-locally heavy rainfall will be possible, especially near any thunderstorms that develop tomorrow afternoon and evening. Rainfall runoff may result in significant ponding of water in normally dry washes, roadway dips and other low-lying areas. Areas with heavy rainfall may result in water running in normally dry washes or minor street flooding. Flash flooding is NOT anticipated. MODERATE IMPACT

2) Rainfall Amounts...between 0.25-0.50 inches are expected in the valleys...with the heavier amounts generally along a line from Nogales to Tucson to Safford. Liquid equivalent precipitation (QPF)
of 0.75 to 1.0 inches are expected in the mountains. MINOR TO MODERATE IMPACT

3) Snow Levels...will start off between 8000-8500 feet tomorrow morning, then lowering during the afternoon and evening to 7000-7500 feet, then eventually down to 7000 feet Saturday morning. MINOR IMPACT

4) Storm-total Snowfall Amounts...between 2 and 6 inches are expected above 7500 feet with this event. Snow will struggle to accumulate until Friday evening, which will limit the potential for heavy snowfall amounts. Snowfall may be moderate-to-heavy at times tomorrow evening, especially near thunderstorms. MINOR TO MODERATE IMPACT

5) Small Hail...will be possible with the stronger showers and thunderstorms. The size will remain small but may briefly accumulate. MINOR IMPACT

6) Breezy Winds...from the south to southwest 15 to 20 mph with winds gusts to 30 mph will be possible during the day Friday into the early evening, especially near the stronger showers or thunderstorms tomorrow afternoon. MINOR IMPACT

DISCUSSION
Minimal changes were made from the previous forecast package with the short term forecast focus on the approaching weather system which will impact southeast Arizona tomorrow. The only minor changes continue to show the best lift associated with the system to arrive by late tomorrow morning through tomorrow evening with the focus more on areas south and east of a Nogales to Tucson to Safford line.

The passage of the trough will help fuel scattered to numerous showers and isolated thunderstorms with periods of moderate to locally heavy rainfall. Small (pea-sized) hail cannot be ruled out in a few of these storms as well. Overall, the most impactful consideration with this system will be rainfall accumulation and intensity. For the valleys, rainfall accumulations will generally be between a quarter to half an inch with locally higher amounts possible in thunderstorms. For the mountains, liquid equivalent precipitation will be between three quarters of an inch to an inch with locally higher amounts from thunderstorms. Snow levels will start off at 8000-8500 feet tomorrow morning but will quickly fall to between 7000-7500 feet overnight. Snow accumulations of 2-6 inches is expected above 7500 feet.

By daybreak Saturday the trough axis will be to our east with most of precipitation also to our east but cannot rule out a few lingering light valley showers and mountain snow showers near the Chiricahua and White Mountains. Saturday afternoon, shortwave ridging will quickly move in allowing skies to clear and high temperatures to rebound to near normal after dropping by nearly 15 degrees on Friday. Brr! By Sunday afternoon temperatures will warm up to around 4 to 6 degrees above normal.

Next, the forecast focus shifts to the next system which will impact the area starting late Monday through early Wednesday. Breezy to windy conditions are expected ahead of the system on Monday and again on Tuesday with sustained southwest winds around 15 to 20 mph and gusts to around 30 mph. Precipitation chances will increase to 40-60% late Monday night through Tuesday morning. Models are still coming into consensus with this next system, but early forecast precipitation amounts are between a quarter to half an inch with models keeping the bulk of the precipitation to the north and east of Tucson.

AVIATION
Valid through 14/00Z.
SCT-BKN clouds AOA 12-15k ft AGL thru 13/15Z with cloud bases lowering to 2-6k ft AGL by around 13/20Z with gradually increasing coverage. SCTD to NUMS SHRA and ISOLD -TSRA resulting in mountain obscurations and periods of MVFR CIG and VSBY. SFC wind this afternoon SWLY to WLY at less than 10 kts becoming VRBL after 13/04Z. Tomorrow, SFC wind SLY to SWLY with speeds of 8-12 kts with OCCNL gusts between 22-26 kts after 13/20Z.

FIRE WEATHER
A cold and wet winter weather system is expected to make its way into Southeast Arizona tomorrow resulting in widespread valley rain and high elevation snowfall. Isolated thunderstorms will also be possible with this system. Min RH levels will be 20 to 30 percent in the valleys and 30 to 40 percent in the mountains this afternoon, then increasing significantly on tomorrow to 35 to 45 percent in the valleys and 45 to 65 percent in the mountains with the arrival of the upcoming weather system.
Although quiet weather will briefly return this weekend with a brief warming trend, unsettled weather returns the first half of next week with periods of valley rain and mountain snow. Strong and gusty southwest winds are possible Monday and Tuesday with speeds of 15-20 mph and gusts around 30 mph.

TWC WATCHES/WARNINGS/ADVISORIES
None.