Area Forecast Discussion
Issued by NWS Flagstaff, AZ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS65 KFGZ 161033
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
335 AM MST TUE SEP 16 2014

.SYNOPSIS...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF THE I-40 CORRIDOR TODAY...SOME STORMS WILL PRODUCE VERY
HEAVY RAIN. ISOLATED STORMS ARE EXPECTED NORTH OF I-40...WITH THE
LEAST COVERAGE NEAR THE UTAH BORDER. DEEP MOISTURE WILL CONTINUE TO
MOVE INTO THE AREA THROUGH WEDNESDAY AND THURSDAY...WITH INCREASING
AND POTENTIALLY PROLONGED PRECIPITATION. A FLASH FLOOD WATCH IS IN
EFFECT FOR AREAS ALONG AND SOUTH OF I-40 ON BOTH OF THOSE DAYS.
SCATTERED SHOWERS AND THUNDERSTORMS WILL THEN CONTINUE THROUGH NEXT
WEEKEND AS MOISTURE LINGERS OVER THE REGION.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS ALREADY BREAKING OUT ALONG
THE LEADING EDGE OF A DEEP MOISTURE GRADIENT APPROACHING CENTRAL
ARIZONA. THIS GRADIENT AND UPPER LEVEL DIVERGENCE AHEAD OF ODILE
WILL BE THE FOCUS FOR STRONGER CONVECTION TODAY...WHICH SHOULD BE
LOCATED ROUGHLY ALONG AND SOUTH OF THE I-40 CORRIDOR FOR OUR CWA.
BEHIND THIS GRADIENT...THERE IS CONSIDERABLE CLOUDINESS ASSOCIATED
WITH ODILE...AS WELL AS SOME MID-LEVEL WARMING AND SUBSIDENCE. THIS
MAY AFFECT OUR ABILITY TO GENERATE DEEP CONVECTION BY WEDNESDAY AND
THURSDAY...ALTHOUGH WIDESPREAD AND FREQUENT SHOWERS WILL STILL BE
OCCURRING.

CURRENT MODELS TRENDS AND OFFICIAL FORECASTS ARE MOVING EASTWARD
WITH ODILE...WITH THE PRECIPITATION SHIELD PRIMARILY AFFECTING SE
ARIZONA. IN ADDITION...THIS TRACK MAY GENERATE SIGNIFICANT EASTERLY
OR NORTHEAST WINDS ACROSS THE AREA...WHICH MAY IMPORT DRIER AIR FROM
THE NORTH. THE CURRENT FLASH FLOOD WATCH WILL NEED TO BE MONITORED
FOR THESE TRENDS...AS WELL AS THE POSSIBILITY FOR STRONG CONVECTION
TODAY...THAT IS WELL IN ADVANCE OF THE WATCH TIME FRAME.

AFTER ODILE EXITS THE SOUTHWEST LATER THURSDAY...MODELS ARE IN
DISAGREEMENT ON A NEW TROUGH DEVELOPING OVER THE SOUTHWEST BY NEXT
WEEKEND. THIS MAY OR MAY NOT DRAW DEEP MOISTURE BACK INTO THE AREA
WHERE IT WILL THEN INTERACT WITH COLDER TEMPERATURES ALOFT AND SOME
SHEAR. GFS DEPICTS THIS AS POSSIBLY A MORE SERIOUS SITUATION THAN
THE NEXT FEW DAYS...WHILE ECMWF TAKES THIS NEW LOW AND RETROGRADES
OUT TO SEA...AWAY FROM ARIZONA. TIME WILL TELL ON THIS AND WE HAVE
LEFT SCATTERED POPS IN THE FORECAST THROUGH NEXT WEEKEND UNTIL THE
SITUATION BECOMES A BIT MORE CLEAR.

&&

.AVIATION...FOR THE 12Z PACKAGE...MOISTURE WILL BE ON THE INCREASE
OVER THE NEXT 24 HOURS IN ADVANCE OF ODILE. UNTIL 18Z...MAINLY VFR
CONDITIONS WITH ISOLATED SHOWERS/TSTORMS IN EASTERN/CENTRAL AZ.
AFTER 18Z...SHOWERS/THUNDERSTORMS WILL INCREASE...MOST NUMEROUS
SOUTH OF A KGCN-KFLG-KRQE LINE. ISOLATED ACTIVITY TO THE NORTH.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...

FLASH FLOOD WATCH FROM 11 AM MST WEDNESDAY THROUGH 6 PM MST THURSDAY
FOR AZ PUBLIC ZONES 007-008-012>018-037-038.

&&

$$

PUBLIC.........PETERSON
AVIATION.......KD

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.