974
FXUS65 KTWC 272200
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
300 PM MST TUE MAY 27 2025
SYNOPSIS
TEMPERATURES WILL GRADUALLY WARM UP THIS WEEK, WITH
THE WARMEST TEMPERATURES ON FRIDAY ROUGHLY 3 TO 7 DEGREES ABOVE
NORMAL. A WEATHER SYSTEM THIS WEEKEND WILL BRING SOME MOISTURE
INTO THE REGION, POSSIBLY BRINGING SCATTERED SHOWERS AND
THUNDERSTORMS FRIDAY INTO THE WEEKEND.
DISCUSSION
SOUTHEASTERN ARIZONA IS CURRENTLY UNDER SOME PASSING
HIGH CLOUDS THIS AFTERNOON THANKS TO A WEAK UPPER LOW MOVING
THROUGH THE AREA TODAY. EVEN WITH THIS CLOUD COVER, WE WILL SEE
TEMPERATURES A TAD WARMER THAN YESTERDAY.
ONCE THIS LOW SLOWLY DISSIPATES, THE UPPER AIR PATTERN BECOMES
MORE ZONAL THEN SLIGHT RIDGING INTO THURSDAY. THIS WILL SLOWLY
INCREASE THE DAYTIME HIGHS 2 TO 6 DEGREES COMPARED TO TODAY, WITH
THE WARMEST DAY ON FRIDAY. WITH THE WARM SURFACE HEATING, NOT
VERY IMPACTFUL AFTERNOON BREEZINESS CAN BE EXPECTED AT 10-15 MPH
AND GUSTS UP TO 25 MPH EACH DAY.
BEGINNING FRIDAY, AN UPPER LEVEL LOW BEGINS TO SIT OFF THE COAST
OF BAJA, MEXICO BRINGING SOUTHERLY/SOUTHEASTERLY FLOW IN THE MID
LEVELS AND WILL BEGIN TO TAP INTO TROPICAL MOISTURE TO THE SOUTH
AND EAST IN NEW MEXICO. THE CURRENT FORECAST IS HAS THE MID-LEVEL
MOISTURE BEGINING TO MOVE INTO THE FAR EASTERN AREAS NEAR THE
ARIZONA/NEW MEXICO STATE LINE ON FRIDAY. THIS WILL MOST LIKELY
TRANSLATE INTO DRY THUNDERSTORMS AND/OR VIRGA FOR THESE AREAS AS
THE INCOMING MOISTURE WILL MOVE OVER A VERY DRY SUB-CLOUD LAYER,
MAKING IT DIFFICULT TO HAVE ANY MEASURABLE/MEANINGFUL RAINFALL
AMOUNTS. SATURDAY IS ALL DEPENDENT ON HOW MUCH MOISTURE CAN BE
RECYCLED AND/OR CONTINUE TO MOVE IN TO DETERMINE IF WE CAN SEE DRY
OR WET SHOWERS/THUNDERSTORMS ACROSS THIS AREA. OVERALL, THERE HAS
BEEN LOTS OF UNCERTAINTY IN MODEL RUNS OVER THE PREVIOUS DAYS
WITH THE FORECAST MODELS FLIP- FLOPPING RUN TO RUN IN TERMS OF
PRECIPITATION CHANCES AND AMOUNTS. SO EVEN THOUGH WE ARE 4 DAYS
OUT FROM ANY POTENTIAL STORM ACTIVITY BEGINNING, THE DETAILS STILL
REMAIN A TAD UNCLEAR.
THE UPPER LEVEL LOW BEGINS TO EJECT AND MOVE OVER THE AREA SUNDAY
INTO MONDAY, BRINGING THE BEST SHOT DYNAMICS WISE TO INFLUENCE
ANY THUNDERSTORM ACTIVITY FOR AREAS TUCSON EASTWARD, BUT EXACT
LOCATIONS, TIMING, AND RAINFALL AMOUNTS WILL BE INFLUENCED BY HOW
FRIDAY AND SATURDAY GO, SO I WOULD NOT BET ON THIS YET. THIS
SYSTEM WILL 'COOL' US DOWN TO NEAR NORMAL TEMPERATURES SATURDAY
INTO THE BEGINNING OF NEXT WEEK. ONCE THIS LOW MOVES OUT OF THE
AREA EARLY NEXT WEEK, DRIER AIR WILL ONCE AGAIN MOVE IN.
AVIATION
VALID THROUGH 29/00Z.
GENERALLY LIGHT AND TERRAIN DRIVEN WINDS THROUGH THE FORECAST
PERIOD WITH A FEW AFTERNOON GUSTS. SCT- BKN CIRRUS BECOMING SKC TO
FEW CIRRUS AFTER 18/12Z. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
FIRE WEATHER
DRY CONDITIONS CONTINUE FOR MOST OF THE UPCOMING
WEEK WITH SINGLE DIGIT MIN RH VALUES AT ALL ELEVATIONS, WITH POOR
OVERNIGHT RECOVERIES. EXPECT SEASONALLY TYPICAL AFTERNOON
BREEZES/GUSTS EACH DAY THROUGH THE WEEK DUE TO STRONG DAYTIME
HEATING.
A MORE VARIABLE WEATHER PATTERN DEVELOPS LATE IN THE WEEK AND INTO
EARLY NEXT WEEK AS A WEATHER SYSTEM TO OUR WEST AND SOUTHWEST WILL
DRAW MOISTURE INTO THE AREA. THE MOISTURE INCREASE WILL INITIALLY
MAINLY OCCUR IN THE MID LEVELS IN FAR EASTERN AREAS (NEAR THE
ARIZONA AND NEW MEXICO STATE LINE) BY FRIDAY, WHERE BUILD-UPS MAY
RESULT IN DRY LIGHTNING. RECENT MODEL RUNS HAVE SEEN AN INCREASE IN
POTENTIAL FOR THIS MOISTURE, INCREASING CONFIDENCE IN THE POTENTIAL
FOR DRY LIGHTNING OVER EASTERN AREAS. THERE REMAINS VARIABILITY IN
MODEL DATA HOWEVER, SO THIS REMAINS SOMEWHAT UNCERTAIN. ADDITIONAL
MOISTURE PUSHING INTO THE AREA IS LIKELY THROUGH THE WEEKEND.
SATURDAY MAY SEE ANOTHER DAY OF BUILD-UPS FOR DRY LIGHTNING, THEN
SUNDAY INTO MONDAY SHOULD FEATURE ADEQUATE MOISTURE FOR SCATTERED
WETTING RAIN OPPORTUNITIES. GUSTY AND ERRATIC WINDS WOULD OCCUR WITH
ANY THUNDERSTORM ACTIVITY. DRY WEATHER RETURNS BY NEXT TUESDAY.
TWC WATCHES/WARNINGS/ADVISORIES
NONE.
PUBLIC...TETRAULT
AVIATION...EDWARDS
FIRE WEATHER....EDWARDS
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page