textproduct: San Joaquin Valley

DISCUSSION

Welcome to your favorite part of the day, reading the Area Forecast Discussion (with some spooky humor)! Wow, what could be more spooky on Halloween than some water falling from the sky!? A disturbance moving into the Pacific Northwest will join forces with the trough that is currently over California, resulting in the H2) and shivering temperatures. Models are confident that Sunday will be the major H2O day for the San Joaquin Valley, but the spookiness of rain does have a chance to start on Halloween night. Looking at 24 hr Precipitation chances, there is a 30-40% chance for the Valley to see at least a wetting (0.1) rain by late Saturday afternoon. Moving later into Halloween night, these chances ramp up to 60-75% chance for wetting rainfall, with the Desert seeing lower chances of 20-40% in this period, and the Sierra/Foothills taking the brunt of the hit with 60-75% chance for at least half an inch. Throughout this period is prime time trick or treating. So remember, your costume may be waterproof, but your dignity after slipping on wet leaves in front of the neighbor's house certainly isn't. One thing to keep in mind, though, is that houses may leave candy out in the bowls instead of answering the door to prevent water getting in their houses, so could be more candy for everyone!

Sunday is looking to be the day for most rain and snowfall. Models continue to be in good agreement that the trough will be digging in further south. Given how deeeep the trough becomes, this will be a moist rainy day for lower elevations and snowy for elevations above 7,000 feet. There is a 15-30% for elevations above that 7,000 feet to see 4 or more of snow by Sunday morning. Areas above 9,000 feet have a 50-60% chance to receive 8 or more of snow by Sunday morning. These values may fluctuate slightly as we approach the precipitation event. Might be a good time to make a "snow crow" instead of having your blow up skeleton get dominated by the fluffy stuff. As for the low elevation souls, the probability of exceeding half an inch (0.5) or more of rain by Sunday evening is 40-60%. As we move closer to the Foothills, that goes up to an 80-90% chance of seeing half an inch or more of rain.

The trough will be fleeing by Sunday night, rather quickly. The rain will vanish quicker than a ghost when you turn on the lights. One minute you're getting soaked, the next it'll be bone-dry and eerily still. Ridging will take place almost immediately after. This will get temperatures up to a more normal range. Theres still a bit of spread, but there is a 10% chance that the maximum temperatures for Monday are above a few degrees above normal for the start of November (71-72 for the SJV). With the high pressure trapping the moisture from the rain in the lower levels, thereth existseth a potential for fog. We dont currently have the probabilities for the fog, but let this serve as your heads up that it may start soon.

Looking ahead with the Climate Prediction Center outlooks, the 6-10 and the 8-14 day outlooks both are hinting at warmer than normal temperatures. The 6-10 day outlook has a 33-40% chance of above normal temperatures, while the 8-14 day outlook ramps that up to a 50-60% chance of above normal temperatures. Precipitation for both of those outlooks remain at the near normal levels.

AVIATION

A reduction in visibility to around 4-5 statute miles due to haze is possible tomorrow morning at KFAT, KVIS, and KBFL. Otherwise, VFR conditions will prevail for the next 24 hours.

AIR QUALITY ISSUES

None.

CERTAINTY

The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is medium.

Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information and/or to provide feedback.

HNX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory from 8 AM Saturday to 7 AM PDT Sunday for CAZ323-326>328-330.