800
FXUS66 KHNX 211118
AFDHNX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HANFORD CA
418 AM PDT TUE JUL 21 2026
UPDATE
AVIATION SECTION UPDATED.
KEY MESSAGES
1. ANOTHER ROUND OF MONSOONAL MOISTURE WILL BRING CHANCES FOR
THUNDERSTORMS ACROSS THE SIERRA NEVADA CREST THROUGH THE MIDDLE
OF THE WEEK.
2. HIGH PRESSURE OVER THE REGION WILL MAINTAIN TEMPERATURES
NEAR SEASON AVERAGES FOR MOST OF THIS WEEK.
3. MAJOR HEATRISK EXPECTED FOR PORTIONS OF THE MOJAVE DESERT IN
THE LATTER PORTION OF THIS WEEK.
DISCUSSION
THE HIGH PRESSURE RIDGE CONTINUES TO REMAIN STATIONARY
THROUGHOUT THIS WEEK, LEADING TO CONSISTENTLY ABOVE NORMAL
TEMPERATURES FOR THE VALLEY AND THE DESERT. THE CURRENT
SOUTHERLY FLOW WILL ALSO CONTINUE TO BRING MONSOONAL MOISTURE
INTO THE REGION THROUGH THE MIDWEEK, ALLOWING FOR THUNDERSTORMS
TO DEVELOP OVER THE SIERRA NEVADA CREST. TUESDAY HAS THE
STRONGEST CHANCES FOR SAID DEVELOPMENT AT 25-45% MAINLY FROM THE
CREST EASTWARDS OVER THE LEEWARD SIDE OF THE RANGE. THESE
CHANCES ALSO COME WITH A 30-50% CHANCE FOR A HALF INCH OF
RAINFALL ABOVE 7000 FEET. THUNDERSTORM PROBABILITIES DO CONTINUE
ON WEDNESDAY, BUT THEY DROP TO 15-25% THAT AFTERNOON AS THE FLOW
OVER CALIFORNIA SLOWLY SHIFTS TO COMING OUT OF THE WEST RATHER
THAN THE SOUTH, WHICH WILL BECOME EVEN MORE PRONOUNCED BY
THURSDAY INTO THE WEEKEND, CAUSING THUNDERSTORM CHANCES TO
DECREASE INTO THE 5-15% RANGE.
LOOKING TO THE LATTER HALF OF THIS WEEK, THE MOJAVE DESERT IN
SOUTHEASTERN KERN COUNTY WILL BEGIN TO SEE MORE WIDESPREAD MAJOR
HEAT RISK DUE TO TEMPERATURES IN THE AFTERNOON NEARING 110 AND
EARLY MORNING LOWS IN THE MID TO UPPER 70'S. THE DAYS WITH THE
HIGHEST HEAT RISK SO FAR ARE THURSDAY THROUGH SATURDAY. THIS
TYPE OF HEAT IS DANGEROUS TO MOST OF THE POPULATION, ESPECIALLY
THOSE WITHOUT PROPER COOLING DURING THE NIGHTTIME HOURS.
MEANWHILE, THE VALLEY IS EXPECTED TO SEE MAINLY MINOR TO
MODERATE HEAT RISK AS THE FORECASTED HIGHS ARE LIKELY TO BE JUST
A FEW DEGREES ABOVE NORMAL, THOUGH ARE JUST AS LIKELY TO BE IN
THE LOWER TRIPLE DIGITS THROUGHOUT THE WEEK. AND ACCORDING TO
THE LATEST MODEL RUNS, THIS PATTERN OF ABOVE NORMAL TEMPERATURES
IS LIKELY TO CONTINUE INTO THE WEEK AFTER NEXT, AS THE CLIMATE
PREDICTION CENTER CONTINUES TO HAVE OUR AREA UNDER THAT CRITERIA
FROM DAY 6 THROUGH DAY 14. THE TIME PERIOD FROM THE 28TH OF
JULY THROUGH THE 3RD OF AUGUST IS ALSO HIGHLIGHTED FOR A SLIGHT
RISK (20-40%) FOR HAZARDOUS TEMPERATURES.
AVIATION
25 TO 50 PERCENT CHANCE OF THUNDERSTORMS OVER THE SIERRA NEVADA
BEGINNING AROUND 17Z AND WILL BE A PROBLEM THROUGH AT LEAST 6Z
WEDNESDAY. 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
NONE.
PUBLIC...EW
AVIATION....JPK
WEATHER.GOV/HANFORD
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