Wildfire in Arizona, June 17 to 27, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
945 AM MST WED JUN 17 2015

.SYNOPSIS...EXPECT ISOLATED SHOWERS AND THUNDERSTORMS SOUTHEAST OF
TUCSON INTO THIS EVENING. OTHERWISE...DRY CONDITIONS WITH VERY HOT
DAYTIME TEMPERATURES WILL PREVAIL INTO THIS WEEKEND. SOME INCREASE
IN MOISTURE WILL PROVIDE A SLIGHT CHANCE OF THUNDERSTORMS MAINLY
EAST AND SOUTH OF TUCSON EARLY NEXT WEEK.

&&

.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY DEPICTED CLEAR SKIES
PREVAIL ACROSS WRN PIMA COUNTY AT THIS TIME...WITH A FEW TO
SCATTERED CIRRIFORM CLOUDS ELSEWHERE ACROSS SE ARIZONA. THE BULK OF
THESE CLOUDS HAVE DEVELOPED DURING THE PAST HOUR OR SO FROM TUCSON
SWWD INTO NWRN SONORA. A SOMEWHAT MOIST REGIME CONTINUES ACROSS THE
AREA...WITH DEWPOINTS AT LOWER ELEVATIONS VALID 16Z RANGING FROM THE
MID 40S-LOWER 50S. THESE TEMPS WERE ESSENTIALLY UNCHANGED VERSUS 24
HOURS AGO. SURFACE TEMPS VALID 16Z WERE NEARLY 2-4 DEGS F LOWER
VERSUS THIS TIME TUE. 17/12Z KTWC SOUNDING PRECIP WATER VALUE OF
0.95 INCH WAS NEARLY 0.10 INCH HIGHER VERSUS 24 HOURS AGO. THE
ENVIRONMENT WAS MODESTLY UNSTABLE AS PER VARIOUS STABILITY INDICES.

17/15Z RUC HRRR DEPICTS THE INITIAL DEVELOPMENT OF SHOWERS/TSTMS TO
OCCUR ON THE CHIRICAHUA MOUNTAINS GENERALLY BETWEEN 18Z-19Z TODAY.
THESE PRECIP ECHOES ARE THEN PROGGED TO MOVE SWWD AND INTO THE
VICINITY OF DOUGLAS EARLY THIS AFTERNOON. PRECIP IS THEN DEPICTED TO
DIMINISH QUICKLY ACROSS FAR SERN SECTIONS LATE THIS AFTERNOON AND
EARLY THIS EVENING.

AT ANY RATE...GIVEN THE TRAJECTORY OF THESE CELLS AS PER THE RUC
HRRR...AND THE SEVERE WIND GUST OF 50 KTS RECORDED AT THE KDUG ASOS
LAST EVENING...AM CONCERNED THAT A SIMILAR EVENT MAY HAPPEN DURING
THE NEXT FEW HOURS. THE POTENTIAL CERTAINLY EXISTS FOR BRIEF WIND
GUSTS AT LEAST IN THE 35-45 KT RANGE WITH ANY SHOWERS/TSTMS THAT
DEVELOP.

OTHERWISE...THE MAIN EMPHASIS FOR THIS FORECAST AREA TODAY...AND
DURING THE NEXT SEVERAL DAYS...IS DAYTIME TEMPS THAT WILL BE SEVERAL
DEGS ABOVE NORMAL. ASIDE FROM THE ISOLATED SHOWERS/TSTMS ACROSS FAR
SERN SECTIONS INTO THIS EVENING...DRY CONDITIONS WILL PREVAIL THRU
SUN. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THROUGH 18/18Z.
EXPECT ISOLATED -TSRA/-SHRA SE OF KTUS DEVELOPING AROUND 18Z TODAY
AND CONTINUING INTO THIS EVENING. THIS ACTIVITY SHOULD MAINLY OCCUR
FROM NEAR KFHU EASTWARD TO THE NEW MEXICO BORDER...INCLUDING KDUG.
THE MAIN IMPACT FROM THESE SHOWERS AND THUNDERSTORMS IS THE
POTENTIAL FOR BRIEF WIND GUSTS OF 40-50 KTS. ANY -TSRA/-SHRA SHOULD
END BY 18/06Z. OTHERWISE...A FEW TO OCCASIONALLY BROKEN CLOUDS
AROUND 8-12K FT AGL WILL PREVAIL INTO THURSDAY MORNING. SURFACE WIND
THIS AFTERNOON WILL BE WLY/NWLY AT 10-15 KTS WITH GUSTS TO 20 KTS.
SURFACE WIND WILL BE LESS THAN 10 KTS AT OTHER TIMES. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...THERE IS A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS ACROSS FAR SOUTHEASTERN COCHISE COUNTY THIS AFTERNOON.
STORMS WILL HAVE THE POTENTIAL TO PRODUCE BRIEF GUSTY WINDS AND A
FEW LIGHTNING STRIKES. OTHERWISE...DRY CONDITIONS ARE EXPECTED
ACROSS THE REST OF THE FORECAST AREA ALONG WITH NEAR-RECORD HIGH
TEMPERATURES THROUGH THIS WEEKEND. DAYTIME MINIMUM RELATIVE HUMIDITY
VALUES WILL GENERALLY RANGE FROM 5 TO 15 PERCENT. EXPECT TERRAIN
DRIVEN WINDS AROUND 15 MPH WITH OCCASIONAL AFTERNOON GUSTS DUE TO
STRONG DAYTIME HEATING. PERIODS OF HAINES 6 CONDITIONS ARE LIKELY
OVER PORTIONS OF THE EASTERN HALF OF THE AREA DURING THE AFTERNOON
AND EARLY EVENING HOURS THROUGH EARLY NEXT WEEK. THEN...A MOISTURE
INCREASE WILL RESULT IN RAIN CHANCES RETURNING TO MAINLY EASTERN
AREAS NEXT TUESDAY.

&&

.PREV DISCUSSION...WATER VAPOR IMAGERY AND 17/00Z UPPER-AIR PLOTS
SHOW THE RIDGE TO OUR WEST OVER THE EASTERN PACIFIC WITH THE RIDGE
AXIS NOSING INTO SOUTHERN CALIFORNIA AND WESTERN ARIZONA. PLENTY OF
DRY MID TO UPPER LEVEL AIR REMAINS IN PLACE OVER MUCH OF THE EASTERN
PACIFIC AND INTO MOST OF ARIZONA...WITH THE EXCEPTION OF THE EXTREME
SOUTHEASTERN PORTION OF THE STATE WHERE HIGHER MOISTURE LINGERS
ACROSS THE REGION AND INTO A LARGE PART OF OLD AND NEW MEXICO.

THE SATELLITE DERIVED BLENDED TOTAL PRECIPITABLE WATER IMAGERY SHOWS
VALUES OF AROUND A THIRD OF AN INCH OVER SOUTH CENTRAL CALIFORNIA...
WITH VALUES GENERALLY RANGING FROM 0.6 - 0.8 INCHES ACROSS MY
FORECAST AREA AND WELL OVER AN INCH TO OUR EAST AND SOUTH...WITH
VALUES EXCEEDING 1.5 INCHES JUST SOUTH OF COCHISE COUNTY IN
NORTHEAST SONORA. YESTERDAYS 17/00Z KTWC SOUNDING SHOWED A PW OF
0.88 INCHES. THE LATEST GPS PW VALUES FROM THE U OF A INDICATE THAT
SIMILAR READINGS CONTINUE AT THIS HOUR. MODEL SOUNDINGS FOR TUCSON
SHOW PW'S DROPPING SLIGHTLY TO AROUND 0.6 -0.7 INCHES BY THIS
AFTERNOON AS THE RIDGE IS EXPECTED TO CONTINUE TO PUSH IN FROM THE
WEST TODAY...BRINGING THE DRIER AIR JUST TO OUR WEST FARTHER EAST.
HOWEVER...AS THIS OCCURS...MOISTURE WILL STILL BE JUST TO OUR SOUTH
AND EAST AND I CAN'T RULE OUT A THUNDERSTORM OR TWO ACROSS THE
EXTREME SOUTHEAST PORTION OF MY FORECAST AREA THIS AFTERNOON...
ESPECIALLY AFTER THE FAIRLY ACTIVE DAY YESTERDAY. SO...I KEPT SINGLE
DIGIT 'SILENT' POPS ALONG THE BORDER WITH NEW MEXICO AND THE
INTERNATIONAL BORDER ADJACENT TO COCHISE COUNTY...BUT ALSO KEPT
ISOLATED ACTIVITY FOR THE DOUGLAS AND CHIRICAHUA MOUNTAINS OF EAST
CENTRAL COCHISE COUNTY FOR THIS AFTERNOON AND THIS AGREES WITH THE
MOS NUMBERS FROM THE GFS AND NAM FOR DOUGLAS.

OUR NEXT PROBLEM OF THE DAY CONTINUES TO BE THE VERY HOT
TEMPERATURES THAT WILL CONTINUE THROUGH THE REMAINDER OF THE WEEK
AND INTO THE WEEKEND AS THE HIGH PRESSURE CURRENTLY TO OUR WEST
EVENTUALLY SHIFTS TO OVERHEAD AND WE HEAT UP EVEN MORE. LOCAL STUDY
CORRELATING HIGH TEMPS WITH 850-700MB THICKNESS VALUES INDICATES 111
DEGS FOR BOTH FRIDAY AND SATURDAY FOR TUCSON. MEANWHILE...MOS
GUIDANCE NUMBERS FROM BOTH GFS AND ECMWF SHOW 110 DEGS FOR FRIDAY...
WHILE EURO REFLECTS THE SAME FOR THURSDAY AS WELL. BASED ON
THIS...DECIDED TO GO WITH 110 DEGS AT TUCSON INTERNATIONAL AIRPORT
FOR BOTH FRIDAY AND SATURDAY. I EVEN INCREASED HIGHS A BIT FOR TODAY
TO 109 DEGS FOR TUCSON AND THE SAME FOR THURSDAY.

BY SUNDAY THE HIGH WILL BE JUST TO OUR NORTHEAST OVER NORTHERN NEW
MEXICO WITH AN INVERTED TROUGH OVER THE SOUTHERN PLAINS. THIS SYSTEM
IS EXPECTED TO CONTINUE MARCHING WEST ACROSS NORTHERN MEXICO AND
WEST TEXAS THROUGH TUESDAY BEFORE STALLING OVER THAT GENERAL
VICINITY LATE IN THE WEEK. THIS WILL LIKELY RESULT IN AN INCREASE IN
SHOWER AND THUNDERSTORM ACTIVITY FOR THE EARLY PART OF NEXT WEEK AS
MOISTURE WILL BE JUST TO OUR SOUTHEAST. FOR NOW JUST EXPECT ISOLATED
SHOWERS AND THUNDERSTORMS TUESDAY AFTERNOON AND EVENING...MAINLY
BETWEEN TUCSON AND THE NEW MEXICO BORDER.

FOR TUCSON...HIGH TEMPS GENERALLY 8 TO 10 DEGS ABOVE NORMAL TODAY
THROUGH SATURDAY...THEN 3 TO 6 DEGS ABOVE NORMAL THEREAFTER. LOW
TEMPS WILL RANGE FROM 5 TO 7 DEGS ABOVE NORMAL THROUGH THE FORECAST
PERIOD.

&&

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

&&

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DISCUSSION/AVIATION...FRANCIS
PREVIOUS DISCUSSION...MOLLERE
FIRE WEATHER...FRENCH