892
FXUS65 KTWC 132015
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
115 PM MST THU AUG 13 2026
SYNOPSIS
TODAY SCATTERED SHOWERS AND THUNDERSTORMS WITH SOME OF THE
STORMS CAPABLE TO PRODUCE BRIEF HEAVY RAIN. DRIER AND HOTTER
CONDITIONS RETURN THIS WEEKEND WITH AN EXTREME HEAT WATCH ISSUED
FOR MONDAY THOUGH WEDNESDAY.
DISCUSSION
WHERE THERE WAS CLEARING THIS MORNING SHOWERS AND THUNDERSTORMS
HAVE DEVELOPED. SUBSTANTIAL MOISTURE REMAINS IN PLACE WITH
SATELLITE DERIVED PWATS AROUND 1.3" TO 1.7", HIGHER VALUES TUCSON
WESTWARD AND SURFACE DEWPOINTS IN THE UPPER 50S TO LOW 60S.
THE WEATHER PREDICTION CENTER (WPC) HAS AREAS TUCSON EASTWARD
IN SLIGHT RISK FOR EXCESSIVE RAINFALL. THE 12Z HREF HIGHLIGHTS
THIS AREA WITH A 10-50% CHANCE FOR GREATER THAN 1 INCH OF
RAINFALL, IN A 3 HOUR PERIOD, WITH POCKETS OF UP TO 2 INCHES
POSSIBLE. WHILE THERE IS SUITABLE INSTABILITY IN PLACE, THE MAIN
CONCERN TODAY IS FLASH FLOODING. THERE IS A CHANCE A STORM OR
TWO COULD PRODUCE GUSTY TO STRONG OUTFLOW WINDS WITH SMALL HAIL.
RAINFALL OVERNIGHT AND OVER THE PAST SEVERAL DAYS HAS MADE THE
AREA HIGHLY SUSCEPTIBLE FOR FLASH FLOODING THUS ANY MORE RAIN
THAT FALLS WILL HAVE A MUCH HIGHER CHANCE TO CAUSE IMPACTS.
TEMPERATURES TODAY WILL BE 5 TO 7 DEGREES BELOW NORMAL.
DRY AIR BEGINS TO MOVE INTO THE AREA BEGINNING TOMORROW MOVING
IN ACROSS THE AREA THROUGH WEEKEND. ENOUGH MOISTURE WILL BE IN
PLACE FOR DAILY CHANCES FOR AFTERNOON INTO THE EVENING SHOWERS
AND THUNDERSTORMS THOUGH THEY WILL MAINLY BE TO THE SOUTH AND
EAST OF TUCSON. DURING THIS TIME TEMPERATURES BEGIN TO GRADUALLY
RISE EVENTUALLY PUSHING HIGH TEMPERATURES 5 TO 7 DEGREES ABOVE
NORMAL. THIS WILL BRING HEATRISK TO MAJOR FOR THE LOWER DESERTS
AND EXTREME FOR SOME LOCALES INCLUDING TUCSON AND SAFFORD BY
MONDAY. DUE TO THIS, AN EXTREME HEAT WATCH HAS BEEN ISSUED
STARTING MONDAY THROUGH WEDNESDAY FOR A MAJORITY OF PIMA COUNTY,
PINAL COUNTY, AND SOUTHERN GRAHAM AND GREENLEE COUNTIES.
TEMPERATURES BEGIN TO COOL THURSDAY AND CHANCES FOR DAILY
THUNDERSTORMS BEGIN TO INCREASE.
AVIATION
VALID THROUGH 15/00Z.
AREA OF SHOWERS AND ISOLATED THUNDERSTORMS WITH CEILING BASES
7-11K FT AGL FROM KTUS EAST WITH GUSTY ERRATIC WINDS OF 30-40
KTS POSSIBLE WITH ANY THUNDERSTORM NOW THROUGH 14/05Z. OUTSIDE
OF STORMS SFC WINDS WLY/NWLY AT 8-12 KTS WITH OCNL GUSTS TO 20
KTS. SFC WINDS LIGHT AND TERRAIN DRIVEN BETWEEN 14/06Z AND
14/16Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
FIRE WEATHER
SCATTERED SHOWERS AND THUNDERSTORMS TODAY WITH THE MAIN CONCERN
BEING HEAVY RAINFALL LEADING TO FLASH FLOODING, GUSTY OUTFLOW
WINDS, AND LIGHTNING. THIS SYSTEM WILL THEN DRAW IN DRIER AIR
FRIDAY INTO THE WEEKEND RESULTING IN A LOW- GRADE MONSOON
PATTERN WITH CHANCE OF STORMS EACH DAY MAINLY SOUTH AND EAST OF
TUCSON. A LITTLE MORE ACTIVE MONSOON PATTERN SETS IN EARLY NEXT
WEEK. MINIMUM RELATIVE HUMIDITY WILL BE 20-40 PERCENT TODAY
LOWERING TO AROUND 15-30 PERCENT THEREAFTER. TEMPERATURES WILL
BE BELOW NORMAL TODAY, THEN WARM UP AGAIN TO ABOVE NORMAL THIS.
OUTSIDE OF THUNDERSTORMS, WINDS TERRAIN DRIVEN TO AROUND 10 MPH
WITH OCCASIONAL AFTERNOON GUSTS TO 20 MPH.
TWC WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WATCH FROM MONDAY MORNING THROUGH WEDNESDAY
EVENING FOR AZZ501-502-504>506-509.
MALARKEY
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