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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST THU OCT 23 2014

.SYNOPSIS...STRONG HIGH PRESSURE ALOFT WILL BRING NEAR RECORD TO 
RECORD HIGH TEMPERATURES AND DRY CONDITIONS FRIDAY AND SATURDAY. A 
COOLING TREND WILL THEN OCCUR BY MONDAY AS A LOW PRESSURE SYSTEM 
MOVES NORTH OF THE AREA. THERE MAY BE A STRAY SHOWER OR TWO IN THE 
WHITE MOUNTAINS AND OVER THE HIGHER TERRAIN ALONG THE NEW MEXICO 
BORDER WITH THE PASSAGE OF THIS SYSTEM SUNDAY AND MONDAY. CONTINUED 
DRY WITH HIGH TEMPERATURES CLOSER TO SEASONAL AVERAGES NEXT WEEK.

&&

.DISCUSSION...THE UPPER RIDGE CENTERED TO OUR SOUTHWEST CONTINUES 
AMPLIFY/BUILD NORTHEAST TODAY. 20Z OBSERVATIONS ACROSS SOUTHERN 
ARIZONA INDICATE VALLEY TEMPERATURES IN THE 80S TO NEAR 90 
DEGREES...WITH A COUPLE OF HOURS OF SOLAR HEATING STILL ON TAP YET. 
THE MODELS ARE IN GOOD AGREEMENT IN SHORT TERM WITH THE CONTINUED 
AMPLIFICATION OF RIDGE AS IT SHIFTS EASTWARD ACROSS THE DESERT 
SOUTHWEST TONIGHT AND FRIDAY. THE RIDGE AXIS WILL THEN BE EAST OF 
THE STATE ON FRIDAY AND SATURDAY. BY SATURDAY...SOUTHWEST FLOW/WAA 
WILL TAKE PLACE ACROSS THE REGION AS A TROUGH BEGINS TO DIG SOUTH 
ALONG THE WEST COAST. THICKNESS VALUES SUPPORT A COUPLE OF DEGREES 
OF HEATING ON FRIDAY (COMPARED TO TODAY'S HIGHS) AND THEN AFTERNOON 
HIGH TEMPERATURES WILL BE NEARLY UNCHANGED SATURDAY. THIS WILL 
RESULT IN NEAR RECORD TO RECORD HIGH TEMPERATURES FRIDAY AND 
SATURDAY. FOR TUCSON...FORECAST HIGHS ARE 94 DEGREES F BOTH FRIDAY 
AND SATURDAY...WHICH IS JUST BELOW RECORD LEVELS. STILL EXPECT A 
STATION OR TWO ACROSS THE FORECAST AREA TO TIE OR BREAK PREVIOUS 
RECORDS DURING THIS UNSEASONABLY WARM PERIOD...AS HIGH TEMPERATURES  
TOP OUT AT 7-12 DEGREES F ABOVE NORMAL.

A TROUGH WILL THEN PUSH EAST ACROSS THE WESTERN UNITED STATES SUNDAY 
AND MONDAY...RESULTING IN A COUPLE OF DEGREES OF COOLING SUNDAY AND 
MORE SIGNIFICANT COOLING ON MONDAY. MAIN MOISTURE/DYNAMIC FIELDS TO 
STAY WELL NORTH OF THE STATE. HOWEVER...BOTH THE GFS/ECMWF MODELS 
INDICATE SOME MOISTURE POOLING RIGHT ALONG THE TROUGH AXIS AS IT 
MOVES EAST ACROSS THE STATE SUNDAY/MONDAY. THERE MAY BE JUST ENOUGH 
MOISTURE TO SQUEEZE OUT A SHOWER OR TWO ACROSS THE HIGHER TERRAIN 
ALONG NEW MEXICO BORDER WITH THE PASSAGE OF THE TROUGH AXIS. HAVE 
PUT IN SOME SINGLE DIGIT POPS SUNDAY AND SLIGHT CHANCE (10%) POPS 
MONDAY IN THE WHITE MOUNTAINS...WITH LESSER VALUES IN THE HIGHER 
TERRAIN SOUTH OF THE WHITE'S ALONG THE NEW MEXICO BORDER.

DRY CONDITIONS AND NEAR NORMAL TEMPERATURES ARE THEN EXPECTED BEHIND 
THE TROUGH PASSAGE TUESDAY AND WEDNESDAY OF NEXT WEEK. THE MODELS 
THEN INDICATE ANOTHER STRONG RIDGE OF HIGH PRESSURE BUILDING OVER 
THE EASTERN PACIFIC/SOUTHWEST US LATE NEXT WEEK FOR A RETURN TO WELL 
ABOVE NORMAL TEMPERATURES.      

&&

.AVIATION...VALID THRU 25/00Z.
MAINLY CLEAR SKIES WILL AND DIURNALLY TERRAIN DRIVEN SURFACE WINDS 
LESS THAN 10 KTS WILL PREVAIL ACROSS SE AZ THROUGH THE PERIOD. 
NORMAL AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...HIGH PRESSURE ALOFT WILL RESULT IN DRY CONDITIONS 
AND A WARMING TREND THROUGH SATURDAY. DIURNALLY TERRAIN DRIVEN 
20-FOOT WINDS WILL BE LESS THAN 15 MPH THROUGH SATURDAY. A SLIGHT 
COOLING TREND AND GUSTY WEST-NORTHWEST WINDS WINDS ARE LIKELY SUNDAY 
AND MONDAY AS A TROUGH OF LOW PRESSURE PASSES TO OUR NORTH. DURING 
THAT TIME PERIOD...A SHOWER CANNOT BE RULED OUT OVER THE HIGHER 
PEAKS NEAR THE NEW MEXICO BORDER.

&&

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

$$

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