545
FXUS65 KTWC 281827
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1127 AM MST SAT MAR 28 2026
KEY MESSAGES
- HAZY SKIES: THE STRONG AND GUSTY EAST WINDS THAT IMPACTED
SOUTHEAST ARIZONA FRIDAY AFTERNOON INTO THIS MORNING HAVE
SUSPENDED DUST INTO THE AIR, RESULTING IN HAZY SKIES.
VISIBILITY MAY BE REDUCED TO AS LOW AS 5 TO 7 MILES, BUT NO
ADVERSE IMPACTS ARE ANTICIPATED.
- THUNDERSTORMS/DRY THUNDERSTORMS: THE COMBINATION OF MOISTURE
MOVING INTO THE AREA FROM THE SOUTH AND A PASSING WEATHER
DISTURBANCE ALOFT WILL RESULT IN A CHANCE OF THUNDERSTORMS
BOTH SUNDAY AND MONDAY. DRIER AIR RESIDING IN THE LOWER LEVELS
WILL RESULT IN THE POTENTIAL FOR DRY THUNDERSTORMS, ESPECIALLY
SUNDAY. THEREFORE, GUSTY AND ERRATIC WINDS TO 35 MPH RESULTING
IN LOCALIZED BLOWING DUST MAY ACCOMPANY THE STRONGER STORMS
SUNDAY.
- RAINFALL: RAINFALL ON SUNDAY WILL BE VERY LIGHT DUE TO THE
DRIER AIR IN THE LOWER LEVELS. WITH INCREASING MOISTURE
MONDAY, THERE IS A BETTER CHANCE FOR WETTING RAINFALL ALBEIT
STILL LIGHT. THERE IS A 30-50 PERCENT CHANCE OF A TENTH INCH
OF RAINFALL MONDAY.
SYNOPSIS
ALTHOUGH GUSTY WINDS ARE EXPECTED TO TAPER OFF THIS
AFTERNOON, HAZY CONDITIONS WILL PERSIST ACROSS SOUTHEAST ARIZONA
DUE TO THE SUSPENDED DUST IN THE AIR. THE BACKDOOR FRONT RESPONSIBLE
FOR THESE WINDS HAVE ALSO IMPORTED COOLER AIR INTO THE EASTERN
PORTIONS OF THE REGION, WITH WARM AFTERNOON TEMPERATURES (10 TO
15 DEGREES ABOVE NORMAL) WEST OF TUCSON AND SLIGHTLY ABOVE NORMAL
TEMPERATURES (0 TO 5 DEGREES ABOVE NORMAL) ACROSS THE VALLEYS EAST
OF TUCSON. IN GENERAL, HIGH TEMPERATURES ARE EXPECTED TO REMAIN
ABOVE NORMAL, LOWERING THE SECOND HALF OF NEXT WEEK. MOISTURE
MOVING INTO THE REGION WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS SUNDAY AND MONDAY, AND AGAIN WEDNESDAY. GUSTY AND
ERRATIC WINDS RESULTING IN LOCALIZED BLOWING DUST MAY ACCOMPANY
THE STRONGER STORMS SUNDAY.
DISCUSSION
ALTHOUGH MOST WILL TAKE SOLACE IN THE LONG AWAITED
COOLER TEMPERATURES ACROSS THE AREA TODAY, THE STRONGER WINDS
ASSOCIATED WITH THE BACKDOOR FRONTAL BOUNDARY THE PAST 24 HOURS
KICKED UP AND SUSPENDED PLENTY OF DUST ACROSS SOUTHERN NEW
MEXICO AND IMPORTED IT INTO OUR NECK OF THE WOODS. THAT HAS LEFT
US WITH SOME VERY HAZY SKIES THIS MORNING, WITH VISIBILITY
AS LOW AS 5 TO 7 MILES IN SOME LOCATIONS. NOT IMPACTFUL, BUT
ICKY NONE-THE-LESS. AS THE STRONG SURFACE HIGH PRESSURE TO OUR
EAST SHIFTS FARTHER EAST, WE WILL SEE SURFACE PRESSURE GRADIENTS
RELAX WITH A RAPID WEAKENING OF THE EAST TO SOUTHEAST WINDS
ANTICIPATED AS WE MOVE INTO THE AFTERNOON HOURS. AT 28/17Z THIS
MORNING, KTUS WAS STILL FROM THE ESE AT 22 KTS GUSTING TO 39
KTS (WITH A PEAK GUST OF 42 KTS). THE WIND ADVISORY WE HAVE IN
EFFECT FOR THE VALLEYS OF SOUTHEAST ARIZONA EXPIRES AT 2 PM MST
THIS AFTERNOON, AND IT LOOKS LIKE THIS WILL BE ALLOWED TO EXPIRE
NATURALLY.
OTHERWISE, THE UPPER PATTERN TODAY IS DEFINED BY A BROAD RIDGE
OF HIGH PRESSURE ALOFT OVER NORTHERN MEXICO/TEXAS AND AN UPPER
TROUGH EXTENDING OFF THE BAJA WITH A TROUGH AXIS EXTENDING FROM
30N/130W SOUTHEAST TOWARD A LOW-CENTER DEVELOPING NEAR 21N/117W.
THE LATEST GOES PRECIPITABLE WATER IMAGERY INDICATED A PLUME OF
DEEPER MOISTURE (0.80-1.00+ INCHES OF PWAT) NOW ACROSS CENTRAL
SONORA MEXICO...SLOWLY MAKING ITS WAY NORTH. ENSEMBLE MEANS OF
THE ECMWF AND GEFS AGREE THIS MOISTURE WILL ADVECT INTO THE
WESTERN HALF OF OUR CWA BY 29/21Z SUNDAY AFTERNOON. INITIALLY,
THIS MOISTURE WILL BE LIMITED TO THE MID-LEVELS RESULTING IN
THE POTENTIAL FOR DRY THUNDERSTORMS SUNDAY AFTERNOON. IN FACT,
THE 28/12Z HREF INDICATED A 50-70 PERCENT PROBABILITY FOR DRY
THUNDERSTORM OUTFLOW WINDS 30+ KTS (4-HR MAX WIND WITHIN 40 KM)
ACROSS WESTERN SANTA CRUZ INTO CENTRAL AND EASTERN PIMA COUNTY
AT 30/00Z SUNDAY AFTERNOON. THE POTENTIAL FOR DRY THUNDERSTORMS
WANES AS THE LOWER-LEVEL MOISTURE MOVES INTO THE AREA SUNDAY
NIGHT INTO MONDAY. THIS WILL BRING ABOUT A BETTER CHANCE FOR
WETTING RAINS MONDAY. THE DYNAMICS ARE NOT OVERLY IMPRESSIVE,
BUT THE PASSAGE OF THE UPPER TROUGH AXIS SUNDAY AFTERNOON/EVENING
AND A RE-NFORCEMENT SHORTWAVE TRACKING ACROSS MONDAY AFTERNOON
WILL BOTH PROVIDE SUPPORT FOR STORMS THE NEXT FEW DAYS. THE
MAIN IMPACT FORM THESE STORMS WILL BE THE POTENTIAL FOR STRONG
AND GUSTY THUNDERSTORMS OUTFLOW WINDS RESULTING IN BLOWING DUST
BOTH SUNDAY AND MONDAY. RAINFALL IMPACTS WILL BE SIGNIFICANTLY
LIMITED SUNDAY DUE TO THE DRIER LOWER-LEVEL AIRMASS, AND
SLIGHTLY LIMITED MONDAY. I WOULD EXPECT THE PRECIPITATION TO
OCCUR TO THE SOUTH AND SOUTHEAST OF TUCSON MONDAY, WITH
GENERALLY LESS THAN A TENTH INCH POSSIBLE. THE STRONGER STORMS
SHOULD BE ABLE TO SUPPORT BETWEEN A QUARTER AND HALF INCH OF
RAIN.
STILL ON TRACK FOR ZONAL FLOW TUESDAY PUSHING THE MOISTURE
ASSOCIATED WITH THIS SYSTEM TO OUR EAST FOR A RETURN TO MAINLY
DRY CONDITIONS. THE MODEL ENSEMBLE MEANS AND DETERMINISTIC RUNS
CONTINUE TO DEPICT ANOTHER SYSTEM MOVING FROM THE EASTERN
PACIFIC INTO THE GREAT BASIN WEDNESDAY. THE BULK OF THE STORMS
WILL REMAIN TO OUR NORTH, BUT THE SOUTHERN PERIPHERY OF THIS
FEATURE WILL SWING THROUGH OUR NECK OF THE WOODS RESULTING IN
ANOTHER CHANCE OF STORMS WEDNESDAY (ESPECIALLY NORTH AND
NORTHEAST OF TUCSON).
AVIATION
VALID THROUGH 29/00Z. SUSPENDED DUST IN THE AIR WILL
RESULT IN AREAS EXPERIENCING VSBY 5-7SM THROUGH THE FORECAST
PERIOD, WITH LOWER SLANTWISE VSBY POSSIBLE ON APPROACH. FEW-SCT
CLOUDS AT 9K-12K FT AGL AND SCT-BKN CLOUDS AOA 20K FT AGL THRU
29/18Z, THEN SCT- BKN 8-11K FT AGL WITH ISOLATED -SHRA/-TSRA
SUNDAY AFTERNOON. SFC WIND ELY/SELY AT 15-22 KTS WITH GUSTS
BETWEEN 30-35 KTS THRU 28/20Z, THEN SLOWLY DIMINISHING SFC WIND.
SFC WIND AFT 28/23Z, ELY/SELY GENERALLY AT 12 KTS OR LESS WITH
A FEW GUSTS TO AROUND 20 KTS PERSISTING THRU THE END OF THE
FORECAST PERIOD. THE STORMS SUNDAY AFTERNOON MAY RESULT IN
ERRATIC GUSTS TO 35 KTS RESULTING IN LOCALIZED VSBY 3-5SM IN
BLDU, POTENTIALLY IMPACTING THE KTUS AND KOLS TERMINALS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
ALTHOUGH GUSTY EAST WINDS ARE EXPECTED TO TAPER
OFF THIS AFTERNOON, HAZY CONDITIONS WILL PERSIST ACROSS SOUTHEAST
ARIZONA DUE TO THE SUSPENDED DUST IN THE AIR. MOISTURE MOVING
INTO THE REGION WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS
SUNDAY AND MONDAY. PRECIPITATION TOTALS WILL BE LIGHT, GENERALLY
LESS THAN ONE-TENTH OF AN INCH WITH THE BETTER CHANCE OF WETTING
RAINS MONDAY TO THE SOUTH AND SOUTHEAST OF TUCSON. DRY LIGHTNING
WILL ALSO BE POSSIBLE WITH THE THUNDERSTORMS, ESPECIALLY SUNDAY.
MINIMUM RH VALUES WILL GENERALLY BE IN THE 15-25 PERCENT RANGE
ACROSS MOST OF SOUTHEAST ARIZONA SUNDAY, INCREASING TO 25 TO 35
PERCENT MONDAY, THEN BACK DOWN AGAIN TUESDAY THROUGH THE REST OF
THE WEEK. THERE WILL BE ANOTHER CHANCE OF PRECIPITATION MAINLY
EAST OF TUCSON TUESDAY NIGHT THROUGH WEDNESDAY AS A SYSTEM MOVES
TO OUR NORTH. THIS SYSTEM WILL ALSO BRING BREEZY SOUTHWEST TO
WEST WINDS TUESDAY AFTERNOON INTO THURSDAY.
TWC WATCHES/WARNINGS/ADVISORIES
WIND ADVISORY UNTIL 2 PM MST THIS AFTERNOON FOR AZZ503>509.
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