538
FXUS65 KSLC 201907
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
107 PM MDT THU AUG 20 2026
KEY MESSAGES, ISSUED 1002 PM MDT WED AUG 19 2026
- BUILDING HIGH PRESSURE WILL BRING A STEADY WARMING TREND IN
TEMPERATURES THROUGH THURSDAY ACROSS THE SOUTH AND THROUGH
FRIDAY ACROSS THE NORTH.
- MONSOON MOISTURE WILL MOVE BACK INTO UTAH AND SOUTHWEST WYOMING
LATE IN THE WEEK, PERSISTING THROUGH AT LEAST EARLY NEXT WEEK.
THIS WILL BRING AN INCREASED THREAT OF SHOWERS AND THUNDERSTORMS
CAPABLE OF PRODUCING FLASH FLOODING.
DISCUSSION, ISSUED 1002 PM MDT WED AUG 19 2026
HIGH PRESSURE CENTERED OVER AZ THIS EVENING WILL
SHIFT EAST ON THURSDAY BEFORE ENDING UP OVER NM/WEST TX OVER THE
WEEKEND WHERE IT IS EXPECTED TO REMAIN IN PLACE INTO EARLY NEXT
WEEK. THIS SHIFT WILL INITIALLY AID IN A CONTINUED WARMING TREND
BEFORE BRINGING INCREASED MOISTURE INTO THE AREA BEGINNING DURING
THE THURSDAY/FRIDAY TIMEFRAME. CURRENT PWATS OF AROUND 0.8 INCHES
IS EXPECTED TO INCREASE TO 1-1.1 INCHES ACROSS THE AREA BY
SATURDAY AFTERNOON.
EXPECT AFTERNOON HIGHS OF NEAR TO ABOVE 100 DEGREES IN MANY
VALLEYS ON THURSDAY EVEN AS MIDLEVEL MOISTURE STARTS TO CREEP INTO
SOUTHERN UTAH. ON FRIDAY, AS THE MOISTURE STARTS TO SURGE INTO
SOUTHERN AND CENTRAL UTAH, TEMPERATURES THERE MAY BEGIN TO COOL
BUT CONTINUE TO TREND SLIGHTLY WARMER OR AT LEAST REMAINING NEAR
PERSISTENCE ACROSS NORTHERN UTAH. THIS MOISTURE, THE INITIAL SURGE
BEING ASSOCIATED WITH A VORT MAX LIFTING THROUGH THE AREA, WILL
THEN SPREAD INTO NORTHERN UTAH BY SATURDAY, ALLOWING FOR A COOLING
TREND THEREAFTER. HEATRISK IS IN THE RED (MAJOR) CATEGORY ACROSS
MANY VALLEY AREAS ON THURSDAY, THEN WILL BECOME MORE CONFINED TO
NORTHERN UTAH FOR FRIDAY. HEAT ADVISORIES ARE IN EFFECT FOR WEST-
CENTRAL THROUGH NORTHWEST UTAH VALLEYS AS A RESULT. THE NEED FOR
ANY WARNINGS IS DIMINISHED DUE TO ACCLIMATION TO HOT TEMPERATURES
THROUGHOUT THE SUMMER.
WITH THE ARRIVAL OF THE MOISTURE, EXPECT INCREASING COVERAGE OF
SHOWERS AND THUNDERSTORMS ALONG WITH INCREASING HEAVY RAIN
POTENTIAL INTO EARLY NEXT WEEK. THERE IS CURRENTLY A MARGINAL RISK
OF EXCESSIVE RAINFALL ACROSS SOUTHERN UTAH THURSDAY AND FRIDAY.
THIS MARGINAL RISK WILL SPREAD THROUGH THE REST OF THE FORECAST
AREA FOR SATURDAY AND SUNDAY.
THE HIGH PRESSURE LOOKS TO SLOWLY START BUILDING WESTWARD AGAIN BY
THE MIDDLE OF NEXT WEEK. DEPENDING ON HOW FOR WEST THE HIGH CENTER
ENDS UP (AS THERE IS STILL SOME MODEL SPREAD IN THIS REGARD), THE
AIRMASS MAY START TO GRADUALLY DRY FOR THE SECOND HALF OF NEXT
WEEK.
AVIATION, ISSUED 1125 AM MDT THU AUG 20 2026
KSLC...WINDS EXPECTED TO SHIFT NW ~19-21Z, WITH A MIX OF MID/HIGH
CLOUDS THROUGH THE DAY. WINDS THEN SHIFT BACK SE ~02-04Z FRIDAY WITH
SOME INCREASE IN HIGH CLOUDS OVERNIGHT. LESS CERTAINTY NOTED ON
WINDS FRIDAY AFTERNOON AS LOW CONVECTION CHANCES (10-20%) AND
ASSOCIATED GUSTY ERRATIC OUTFLOWS WILL BRING POTENTIAL PERIODS OF
VARIABILITY.
REST OF UTAH AND SOUTHWEST WYOMING...SCATTERED CONVECTION EXPECTED
THURSDAY AFTERNOON ALONG/EAST OF UTAH'S HIGH TERRAIN AND INTO SW
WYOMING. ASIDE FROM POTENTIAL FOR GUSTY ERRATIC OUTFLOW, ANTICIPATE
WINDS TO LARGELY FOLLOW A DIURNALLY TYPICAL PATTERN. CLOUD COVER
WILL TREND UPWARD AS MOISTURE INCREASES OVERNIGHT INTO FRIDAY.
SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS ARE THEN ONCE AGAIN
EXPECTED, WITH COVERAGE HIGHEST ACROSS SOUTHERN AND CENTRAL UTAH.
FIRE WEATHER
MONSOONAL MOISTURE IS EXPECTED TO INCREASE ACROSS UTAH
THROUGH THE WEEKEND, BRINGING INCREASED COVERAGE OF SHOWERS AND
THUNDERSTORMS ACROSS THE HIGH TERRAIN IN THE REGION. IN ADDITION
TO SHOWER AND THUNDERSTORM ACTIVITY, A TREND OF INCREASING
HUMIDITY IS EXPECTED AREAWIDE. THAT SAID, LOWER ELEVATIONS OF
WESTERN, EASTERN, AND SOUTHERN UTAH WILL CONTINUE TO SEE MINIMUM
RELATIVE HUMIDITY VALUES IN THE MID- TO UPPER-TEENS. FOR THE
HIGHER TERRAIN AREAS, MINIMUM VALUES MAY ONLY FALL INTO THE 25 TO
35 PERCENT RANGE WITH GOOD TO EXCELLENT RECOVERY EXPECTED
AREAWIDE. WHILE PROBABILITY FOR WETTING RAINS WILL BE RELATIVELY
HIGH OVER THE MOUNTAINOUS TERRAIN (UP TO 45-60 PERCENT CHANCE),
LOWER LYING ADJACENT VALLEY AREAS WILL SEE FAR LOWER CHANCES (15
PERCENT OR LESS). ON FRIDAY IN PARTICULAR, DEVELOPING STORMS WILL
BRING POTENTIAL FOR STRONG OUTFLOW WINDS OVER CENTRAL AND NORTHERN
UTAH. DAILY SHOWER AND THUNDERSTORM CHANCES WILL BE MAINTAINED THROUGH
AT LEAST TUESDAY NEXT WEEK, WITH STORMS EXPECTED TO DEVELOP OVER THE
HIGH TERRAIN FEATURES EACH AFTERNOON.
SLC WATCHES/WARNINGS/ADVISORIES
UT...HEAT ADVISORY UNTIL 7 AM MDT SATURDAY FOR UTZ101>106.
HEAT ADVISORY UNTIL 7 AM MDT FRIDAY FOR UTZ115-116.
WY...NONE.
PUBLIC...CHENG
AVIATION...WARTHEN
FIRE WEATHER...WEBBER
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY
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