Red Flag Warning 20, NWS Tucson, AZ

373 
WWUS85 KTWC 220240
RFWTWC

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE TUCSON AZ
740 PM MST WED MAY 21 2014

AZZ150>152-220345-
/O.CAN.KTWC.FW.W.0020.000000T0000Z-140522T0300Z/
ARIZONA FIRE WEATHER ZONE 150
WESTERN PIMA COUNTY-SOUTH CENTRAL PINAL COUNTY-
TOHONO OODHAM NATION-TDC-ARIZONA FIRE WEATHER ZONE 151
EASTERN PIMA COUNTY-SOUTHEASTERN PINAL COUNTY-
SANTA CRUZ COUNTY-WESTERN COCHISE COUNTY-
CORONADO NF-TDC-ARIZONA FIRE WEATHER ZONE 152
SOUTHERN GRAHAM COUNTY-CENTRAL AND EASTERN COCHISE COUNTY-
SOUTHERN GREENLEE COUNTY-
LOWER ELEVATIONS OF THE SAN CARLOS APACHE NATION 
IN GRAHAM COUNTY-CORONADO NF-SAFFORD BLM-TDC-
740 PM MST WED MAY 21 2014

...RED FLAG WARNING IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN TUCSON HAS CANCELLED THE RED FLAG
WARNING. 

THE STRONG AND GUSTY WINDS THAT PROMPTED THE RED FLAG WARNING THIS
AFTERNOON HAVE SIGNIFICANTLY DECREASED THIS EVENING BELOW CRITICAL
THRESHOLDS. THEREFORE...THE RED FLAG WARNING HAS BEEN CANCELLED.

HOWEVER...STRONG AND GUSTY SOUTHERLY WINDS WILL RETURN TOMORROW TO
LOCATIONS ACROSS SOUTH-CENTRAL AND FAR SOUTHEAST ARIZONA. THIS
WILL POSSIBLY RESULT IN CRITICAL FIRE WEATHER CONDITIONS THURSDAY.

$$


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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
202 PM MST WED MAY 21 2014

.SYNOPSIS...A DEEP LOW PRESSURE SYSTEM MOVING ACROSS THE DESERT
SOUTHWEST WILL GENERATE GUSTY WINDS AND A COOLING TREND THROUGH
FRIDAY. THIS SYSTEM WILL ALSO BRING ISOLATED TO SCATTERED
THUNDERSTORMS MAINLY FRIDAY AND SATURDAY.

&&

.DISCUSSION...THERE HAVE BEEN DECENT WIND GUSTS THIS AFTERNOON IN
THE WAKE OF THE MID LEVEL WIND MAX THAT PASSED BY THIS MORNING.
ALSO...TEMPERATURES HAVE WARMED NICELY...AIDING IN MIXING. FOR THE
MOST PART THESE WINDS SHOULD DECREASE WITH SUNSET...BUT DECENT MID
LEVEL GRADIENT MAY SPAWN A FEW GUSTS OVERNIGHT DOWNWIND OF HIGHER
TERRAIN.

THE UPPER LOW OVER NEVADA EXPECTED TO WAFT INTO SRN CALIF THUR
BEFORE MOVING EAST ACROSS AZ FRI/SAT. THUS SOUTHERLY GRADIENT WILL
REMAIN FAIRLY STRONG THURSDAY SO ANOTHER GUSTY AFTERNOON IS LIKELY
ESPECIALLY NEAR SHOWERS.

SPEAKING OF SHOWERS...THOSE CHANCES WILL BE INCREASING AS THE COOLER
AIR ALOFT ASSOCIATED WITH THE UPPER LOW APPROACHES. ATMOSPHERE LOOKS
TO BE UNSTABLE ENOUGH TO SUPPORT THUNDERSTORMS THU-SUN. FRIDAY AND
SATURDAY STILL FIGURE TO OFFER THE BEST OVERALL COVERAGE OF CLOUD
BUILDUPS...LIGHT RAIN SHOWERS AND THUNDER.  THE HIGHER TERRAIN OF
GRAHAM AND GREENLEE COUNTIES NE OF TUCSON ARE STILL THE MOST LIKELY
TO SEE MEASURABLE PRECIPITATION...BUT AGAIN...RAIN AMOUNTS ARE NOT
EXPECTED TO BE TOO SIGNIFICANT.  ANY INCREASE IN MOISTURE WOULD HELP
THE FIRE SITUATION...BUT LIGHTNING MAY THREATEN TO CREATE MORE
STARTS.  SEE FIRE WEATHER DISCUSSION BELOW FOR MORE DETAILS.

ONCE THIS LOW PASSES BY...EXPECT UPPER RIDGING AND STRONG WARMING
BEGINNING SUNDAY...POSSIBLY HEADING BACK TOWARD TRIPLE DIGITS BY MID
WEEK.

&&

.AVIATION...VALID THRU 23/00Z.  SFC WINDS WILL DIMINISH THIS EVENING
AS DAYTIME HEAT IS LOST. THAT BEING SAID...A FAIR AMOUNT OF MID
LEVEL MOISTURE EXIST...EVEN THOUGH IT IS RATHER SHALLOW...WHICH
COULD PRODUCE SOME VIRGA SHOWERS ACROSS THE AREA. THE MAIN AREA WILL
BE ACROSS AREAS EAST OF TUCSON WHERE A MODERATE CU FIELD HAS
DEVELOPED THIS AFTERNOON. GIVEN THE DRY LOW LEVEL CONDITIONS AND THE
POTENTIAL FOR VIRGA SHOWERS THERE WILL BE A THREAT OF GUSTY OUTFLOW
WINDS AT ALL TERMINALS THIS EVENING. THE UPPER LEVEL SYSTEM THAT
HAS ADVECTED THIS MOISTURE INTO THE AREA WILL CONTINUE TO DIG
SOUTHWARD OVER THE NEXT 24 HOURS AND BRING MUCH COOLER MID LEVELS.
THIS WILL ALLOW FOR SOME THUNDERSTORM DEVELOPMENT AND AN INCREASED
THREAT OF GUSTY OUTFLOW WINDS AOA THE TERMINALS. HOWEVER...HAVE
LEFT MENTION OUT OF THE TAFS DUE TO LOW CONFIDENCE IN CONVECTIVE
INITIATION. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...THE UPPER LOW PRESSURE SYSTEM CENTERED OVER SOUTHERN
CALIFORNIA WILL CONTINUE TO SLOW DIG SOUTHWARD...WITH THE CENTER
NEAR NORTHERN BAJA BY FRIDAY AND TRACKING THROUGH THE FORECAST AREA
DURING THE WEEKEND. IN THE MEANTIME...EXPECT ANOTHER DAY OR TWO OF
BREEZY WINDS...ESPECIALLY NEAR NOGALES TOMORROW.

AS THE SYSTEM GETS CLOSER TO THE AREA COOLER MID LEVEL TEMPERATURES
WILL ALLOW FOR ORGANIZED CONVECTION/THUNDERSTORM DEVELOPMENT. THE
BASE OF THE CLOUD DECK WILL LIKELY BE ABOVE 15KFT...WITH DRY
CONDITIONS BELOW. THEREFORE...THE THREAT OF GUSTY OUTFLOW WINDS WILL
EXIST. IN ADDITION TO THE WINDS THERE WILL BE A THREAT OF DRY
LIGHTNING GIVEN THE MORE UNSTABLE UPPER ATMOSPHERE EXPECTED STARTING
TOMORROW. THIS EVENING THERE REMAINS A GOOD CAP JUST ABOVE THE CLOUD
BASE WHICH WILL LIMIT LIGHTNING BUT VIRGA SHOWERS WILL BE STILL
POSSIBLE...MAINLY EAST OF TUCSON.

BETTER MOISTURE WILL BE IN PLACE FRIDAY AND SATURDAY...WHICH WILL
CONTRIBUTE TO SOME MEASURABLE PRECIP POTENTIAL. THE MAIN AREAS WILL
BE IN THE HIGHER TERRAIN NORTHEAST OF TUCSON. THOUGH...EVEN WITH THE
ADDED MOISTURE THERE WILL BE A THREAT OF GUSTY OUTFLOW WINDS. BY
SUNDAY THE SYSTEM WILL BE EXITING ARIZONA AND SLIDING INTO SOUTHERN
COLORADO WHICH WILL ALLOW THINGS TO DRY OUT AND RETURN TO A MORE
NORMAL DIURNALLY DRIVEN WINDS.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

DROZD/MEADOWS

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