380
FXUS65 KTWC 160825
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
125 AM MST MON MAR 16 2026
SYNOPSIS
HIGH PRESSURE ALONG THE WEST COAST WILL RESULT IN
WARM AFTERNOON TEMPERATURES THE NEXT FEW DAYS. MORE SIGNIFICANT
HEAT IS ON TAP FOR THE SECOND HALF OF THE WEEK INTO THE WEEKEND
AS HIGH PRESSURE STRENGTHENS ACROSS THE DESERT SOUTHWEST. HIGH
TEMPERATURES WILL BECOME 20 TO 25 DEGREES ABOVE NORMAL DURING
THIS PERIOD, ESPECIALLY FRIDAY AND SATURDAY.
DISCUSSION
THE UPPER PATTERN THIS MORNING IS DEFINED BY A HIGH
AMPLITUDE RIDGE OF HIGH PRESSURE ALONG THE WEST COAST, WITH A HIGH
CENTER POSITIONED OFF THE CENTRAL CALIFORNIA COAST NEAR 36N/127W.
THE AMPLITUDE OF THE MEAN UPPER RIDGE WILL PUSH A SURFACE HIGH
SOUTH ALONG THE ROCKIES INTO ERN NM/WRN TX TODAY, RESULTING IN A
WEAK BACK-DOOR FRONT NUDGING INTO THE EXTREME SE CORNER OF
ARIZONA. THIS FRONT WILL REALLY STRUGGLE TO GET WEST OF THE
CONTINENTAL DIVIDE IN SW NM, BUT SHOULD BE ENOUGH TO COOL
AFTERNOON TEMPERATURES DOWN A FEW DEGREES EAST OF TUCSON. SO,
INSTEAD OF IT BEING 10 TO 15 DEGREES ABOVE NORMAL SUNDAY, IT WILL
BE 10-15 DEGREES ABOVE NORMAL FROM TUCSON WEST, AND 5 TO 10
DEGREES ABOVE NORMAL EAST OF TUCSON TO THE AZ/NM BORDER.
OTHERWISE, THE MEAN RIDGE AXIS WILL SLOWLY TRACK EAST THE NEXT FEW
DAYS, WITH THE HIGH CENTER MOVING THROUGH SOUTHERN CALIFORNIA
WEDNESDAY, AND INTO SOUTHWEST ARIZONA THURSDAY AND FRIDAY. THE
16/00Z ECMWF (596 DAM) AND GEFS (595 DAM) ENSEMBLE MEANS PEAK
AROUND 20/06Z THURSDAY EVENING OVER SOUTH CENTRAL ARIZONA, WEAKENING
SUNDAY AS THE RIDGE FLATTENS INTO SONORA AND CHIHUAHUA MEXICO.
THE HOTTEST TEMPERATURES WILL BE ON FRIDAY AND SATURDAY, WITH
READINGS 100 TO 108 DEGREES FROM TUCSON WEST INTO THE LOWER
DESERTS, AND 95 TO 100 DEGREES IN THE EASTERN VALLEYS. THESE
READING ARE 20 TO 25 DEGREES ABOVE NORMAL, AND WILL RESULT IN A
MODERATE TO MAJOR HEATRISK ACROSS THE LOWER ELEVATIONS OF
SOUTHEAST ARIZONA. WE STILL HAVE AN EXTREME HEAT WATCH IN EFFECT
FROM THURSDAY INTO SUNDAY, AND CONFIDENCE IS HIGH THAT THESE
TEMPERATURES WILL PAN OUT. THIS IS SUPPORTED BY THE 16/05Z NBM
PROBABILITY OF 100+ DEGREES AT THE TUCSON INTERNATIONAL AIRPORT
(KTUS) OF 50-60% THURSDAY, 80-90% FRIDAY AND SATURDAY, AND 50-60%
AGAIN SUNDAY. THE GOOD NEWS IS THAT THERE IS AN END IN SIGHT FOR
THE HEAT. NUMERICAL MODELS WANT TO FLATTEN OUT THE RIDGE WITH AN
IMPULSE MOVING EAST INTO THE GREAT BASIN LATE SUNDAY INTO MONDAY.
UNTIL THEN, ALL THE ATTENTION WILL BE ON THE HEAT SLATED TO IMPACT
SOUTHEAST ARIZONA THE SECOND HALF OF THE WEEK.
AVIATION
VALID THROUGH 17/12Z. SCT-BKN CIRRUS CLOUDS AT OR
AROUND 20K FT AGL THROUGH THE FORECAST PERIOD. SURFACE WINDS
GENERALLY TERRAIN DRIVEN AND LESS THAN 10 KTS THROUGH 16/17Z. SFC
WINDS EAST OF TUCSON WILL THEN BE SOUTHEASTERLY 10-15 KTS WITH
GUSTS TO 20 KTS THIS AFTERNOON WITH THE STRONGEST WINDS IN KSAD.
FROM TUCSON WEST, NORTHWESTERLY SURFACE WINDS AROUND 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
HIGH PRESSURE ALONG THE WEST COAST WILL RESULT IN
WARM AFTERNOON TEMPERATURES THE NEXT FEW DAYS. MORE SIGNIFICANT
HEAT IS ON TAP FOR THE SECOND HALF OF THE WEEK INTO THE WEEKEND
AS HIGH PRESSURE STRENGTHENS ACROSS THE DESERT SOUTHWEST. HIGH
TEMPERATURES WILL BECOME 20 TO 25 DEGREES ABOVE NORMAL DURING
THIS PERIOD, ESPECIALLY FRIDAY AND SATURDAY. A SURFACE HIGH
PRESSURE MOVING SOUTH ACROSS EASTERN NEW MEXICO WILL RESULT IN
EASTERLY 20-FOOT WINDS 5 TO 15 MPH WITH GUSTS TO 10-25 MPH ALONG
THE ARIZONA/NEW MEXICO BORDER TODAY. OTHERWISE, 20-FOOT WINDS
WILL BE WESTERLY UNDER 5 TO 10 MPH WITH A FEW AFTERNOON GUSTS TO
20 MPH THROUGH SATURDAY. MINIMUM RHS 8-18 PERCENT AREAWIDE
THROUGH THE MIDDLE OF THE WEEK, THEN LOWERING INTO THE SINGLE
DIGITS LATE THIS WEEK INTO THIS WEEKEND.
TWC WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WATCH FROM THURSDAY MORNING THROUGH SUNDAY EVENING
FOR AZZ501>509.
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