473
FXUS65 KTWC 180820
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
120 AM MST WED MAR 18 2026
SYNOPSIS
SIGNIFICANTLY HOT TEMPERATURES EXPECTED THE SECOND HALF OF WEEK
THROUGH THE WEEKEND. HIGH TEMPERATURES WILL BE 20 TO 25 DEGREES
ABOVE NORMAL DURING THIS PERIOD, ESPECIALLY FRIDAY AND SATURDAY.
VISITORS, SEASONAL RESIDENTS, AND OTHER PEOPLE NOT TYPICALLY
ACCUSTOMED TO OR ACCLIMATED TO EXTREME HEAT ARE ESPECIALLY URGED
TO TAKE PRECAUTIONS DURING THE HOTTEST HOURS OF THE DAY DURING
THIS PERIOD AND LIMIT OUTDOOR ACTIVITY.
DISCUSSION
STRONG RIDGING IN THE SOUTHWESTERN US IS LEADING TO AN ANOMALOUS
HIGH PRESSURE SYSTEM. THE CENTER OF THE HIGH IS CURRENTLY LOCATED
IN SOUTHERN CALIFORNIA AND WILL GRADUALLY MOVE EASTWARD INTO
SOUTHERN ARIZONA IN THE NEXT 36 TO 48 HOURS. THE INTENSITY OF THIS
HIGH PRESSURE IS MORE INDICATIVE TO MID-SUMMER VALUES AND EVEN
WOULD BE UNUSUALLY FOR LATE SPRING. THIS WILL LEAD TO WELL-ABOVE
NORMAL TEMPERATURES, 20-25 DEGREES WARMER, ACROSS SOUTHEASTERN
ARIZONA. SEVERAL DAYTIME AND MONTHLY RECORDS ARE LIKELY TO BE
BROKEN THIS WEEKEND. THE PREVIOUS RECORD OF 99 DEGREES SET MARCH
26, 1988 US ON TAP TO BE BROKEN AS WELL AS THE EARLIEST 100
DEGREE DAY IN TUCSON (CURRENT RECORD APRIL 11, 2025). IN FACT THE
CURRENT 7 DAY FORECAST FOR TUCSON INCLUDES 6 CONSECUTIVE DAYS
(THURSDAY- TUESDAY) OF RECORD SETTING HIGH TEMPERATURES. DUE TO
THE TRULY ABNORMAL HEAT FOR THIS TIME OF YEAR, AN EXTREME HEAT
WARNING IS IN EFFECT FROM THURSDAY MID-MORNING THROUGH SUNDAY
EVENING. HEAT WILL BE AT DANGEROUS LEVELS FOR THOSE UNACCUSTOMED
OR NOT YET ACCLIMATED TO THE HEAT AT THIS POINT IN THE YEAR.
THERE IS SOME REPRIEVE IN THE FORECAST. EARLY NEXT WEEK THE UPPER
RIDGE WILL FLATTEN WITH ITS CENTER SHIFTING SOUTH INTO NORTHERN
MEXICO. WHILE TEMPERATURES WILL REMAIN WELL ABOVE NORMAL, THIS
WILL "COOL" HIGHS DOWN FROM THE RECORD SETTING LEVELS TO 15-20
DEGREES ABOVE NORMAL. AFTERNOON BREEZY WESTERLY WINDS WILL ALSO
LIKELY ARRIVE WITH THIS PATTERN SHIFT. LONG RANGE ENSEMBLE MODELS
SHOW RIDGING RETURNING THE SECOND HALF OF NEXT WEEK WITH THE CPC
NOTING A MODERATE RISK FOR MUCH ABOVE NORMAL TEMPERATURES.
AVIATION
VALID THROUGH 19/12Z.
MOSTLY SKC WITH A FEW HIGH CLOUDS AOA 20-25K FT. SFC WINDS NW-
LY/W-LY AT 7-10 KTS WITH GUSTS UP TO 15 KTS AFT 18/18Z THRU
19/03Z. OTHERWISE, SFC WINDS ARE TERRAIN DRIVEN AND REMAIN UNDER
10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
BUILDING HIGH PRESSURE FROM THE WEST WILL BRING PROGRESSIVELY
HOTTER TEMPERATURES TO SOUTHEASTERN ARIZONA OVER THE NEXT SEVERAL
DAYS. SIGNIFICANT HEAT IS EXPECTED FOR THE SECOND HALF OF THE
WEEK INTO THE WEEKEND AS HIGHS WILL BECOME 20 TO 25 DEGREES ABOVE
NORMAL. WINDS THROUGH THE REMAINDER OF THE WORK WEEK WILL
GENERALLY BE UNDER 10 MPH WITH A FEW AFTERNOON GUSTS TO 20 MPH.
BREEZIER CONDITIONS POSSIBLE SUNDAY INTO EARLY NEXT WEEK. MINIMUM
RHS 8-18 PERCENT THROUGH WEDNESDAY BECOMING 5-12 PERCENT AREAWIDE
BY THURSDAY THROUGH EARLY NEXT WEEK.
TWC WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING FROM 11 AM THURSDAY TO 8 PM MST SUNDAY FOR
AZZ501>509.
MALARKEY
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