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000
FXUS65 KTWC 292226
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
325 PM MST THU JAN 29 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
ESPECIALLY TONIGHT INTO SATURDAY. MINOR FLOODING MAY OCCUR DUE TO
PERIODS OF HEAVY RAINFALL. THE MOST SIGNIFICANT SNOWFALL WILL BE
ABOVE 8000 FEET...OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH COOLER
DAYTIME TEMPERATURES FRIDAY INTO THIS WEEKEND. DRY CONDITIONS WITH A
WARMING TREND WILL THEN OCCUR EARLY NEXT WEEK.

&&

.DISCUSSION...UPPER LEVEL TROUGH WAS ADJACENT THE CALIFORNIA/BAJA
CALIFORNIA COASTS WITH 568 DM LOW CENTERED NEAR 29N/120W THIS
AFTERNOON. THE UPPER TROUGH WILL MOVE EWD INTO THE SWRN CONUS
TONIGHT AND REMAIN QUASI-STATIONARY INTO SAT. ABUNDANT MOISTURE WILL
MOVE INTO THE AREA...WITH TOTAL PRECIP WATER VALUES PERHAPS NEARING
1.20 INCHES BY SAT. SHOWERS WILL INCREASE IN COVERAGE EARLY THIS
EVENING...THEN NUMEROUS SHOWERS PRODUCING POTENTIALLY LOCALLY HEAVY
RAINFALL WILL OCCUR LATER TONIGHT AND CONTINUING FRI. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS FRI AFTERNOON/EVENING DUE TO WEAK
INSTABILITY WITH MUCAPE AOB 300 J/KG.

RAINFALL INTENSITY SHOULD DECREASE PERHAPS AS EARLY AS FRI
EVENING...BUT MORE LIKELY LATE FRI NIGHT AND ESPECIALLY SAT.
HOWEVER...AMPLE MOISTURE CONTINUING ACROSS THE AREA IN COMBINATION
WITH WEAK SYNOPTIC SCALE ASCENT DUE TO THE PRESENCE OF THE UPPER LOW
WILL LEAD TO WIDESPREAD SHOWER COVERAGE. A SLIGHT CHANCE OF
THUNDERSTORMS WILL CONTINUE SAT AFTERNOON DUE TO AN ENVIRONMENT OF
WEAK AOB 300 J/KG MUCAPE. THE UPPER LOW THAT IS PROGGED TO BE
CENTERED OVER THE LOWER COLORADO RIVER VALLEY MIDDAY SAT IS PROGGED
TO MOVE SWD INTO THE NRN GULF OF CALIFORNIA SAT NIGHT...THEN MOVE
SLOWLY SEWD ACROSS SONORA MEXICO SUN. THERE SHOULD BE ENOUGH
MOISTURE TO MAINTAIN A SLIGHT CHANCE OF SHOWERS FROM TUCSON EWD/SWD
SUN.

STORM TOTAL LIQUID AMOUNTS ARE FORECAST TO GENERALLY RANGE FROM 0.50
TO 1.50 INCHES IN THE VALLEYS...WITH SOME AMOUNTS IN EXCESS OF 2.00
INCHES POSSIBLE. LIQUID AMOUNTS ACROSS THE MOUNTAINS WILL GENERALLY
RANGE FROM 1.00 - 2.00 INCHES. HOWEVER...LIQUID AMOUNTS IN EXCESS OF
2 INCHES SHOULD OCCUR ACROSS SOME MOUNTAINS...PARTICULARLY FROM THE
CATALINA/RINCON MOUNTAINS NEAR TUCSON NEWD TO THE WHITE MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EVEN EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-THUR. MUCH COOLER TEMPS
WILL OCCUR FRI AND SAT...WITH HIGH TEMPS ACROSS THE AREA TO AVERAGE
ABOUT 5-10 DEGS F BELOW NORMAL. A WARMING TREND WILL THEN OCCUR
SUN-THUR.

&&

.AVIATION...VALID THRU 31/00Z.
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EASTWARD INTO SOUTHEAST
ARIZONA INTO FRIDAY. THIS SYSTEM WILL BRING A SIGNIFICANT AMOUNT AND
MOISTURE RESULTING IN WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW.
THERE IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS ACROSS MUCH OF THE
AREA FRIDAY AFTERNOON. CLOUD DECKS EARLY THIS EVENING WILL GENERALLY
BE AT 6-10K FT AGL...THEN LOWER TO GENERALLY 2-3K FT AGL BY FRIDAY
MORNING. HIGHER TERRAIN WILL BE OBSCURED FRIDAY IN CLOUDS AND
PRECIPITATION. SURFACE WIND WILL GENERALLY BE SELY/SLY AT 5-15 KTS
THRU THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW
TONIGHT INTO SATURDAY. THE MOST SIGNIFICANT SNOWFALL WILL OCCUR
ACROSS THE HIGHEST PEAKS OF THE WHITE MOUNTAINS...MOUNT GRAHAM...AND
THE CATALINA AND RINCON MOUNTAINS NEAR TUCSON. A FEW LINGERING
SHOWERS WILL OCCUR MAINLY EAST TO SOUTH OF TUCSON SUNDAY...THEN DRY
CONDITIONS WILL PREVAIL SUNDAY NIGHT THROUGH THURSDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WARNING FROM 5 AM FRIDAY TO NOON MST SATURDAY FOR
    AZZ510-511 ABOVE 7000 FEET.

    WINTER STORM WARNING FROM 11 AM FRIDAY TO NOON MST SATURDAY FOR
    AZZ514 ABOVE 7000 FEET.

&&

$$

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FRANCIS






000
FXUS65 KTWC 292226
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
325 PM MST THU JAN 29 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
ESPECIALLY TONIGHT INTO SATURDAY. MINOR FLOODING MAY OCCUR DUE TO
PERIODS OF HEAVY RAINFALL. THE MOST SIGNIFICANT SNOWFALL WILL BE
ABOVE 8000 FEET...OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH COOLER
DAYTIME TEMPERATURES FRIDAY INTO THIS WEEKEND. DRY CONDITIONS WITH A
WARMING TREND WILL THEN OCCUR EARLY NEXT WEEK.

&&

.DISCUSSION...UPPER LEVEL TROUGH WAS ADJACENT THE CALIFORNIA/BAJA
CALIFORNIA COASTS WITH 568 DM LOW CENTERED NEAR 29N/120W THIS
AFTERNOON. THE UPPER TROUGH WILL MOVE EWD INTO THE SWRN CONUS
TONIGHT AND REMAIN QUASI-STATIONARY INTO SAT. ABUNDANT MOISTURE WILL
MOVE INTO THE AREA...WITH TOTAL PRECIP WATER VALUES PERHAPS NEARING
1.20 INCHES BY SAT. SHOWERS WILL INCREASE IN COVERAGE EARLY THIS
EVENING...THEN NUMEROUS SHOWERS PRODUCING POTENTIALLY LOCALLY HEAVY
RAINFALL WILL OCCUR LATER TONIGHT AND CONTINUING FRI. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS FRI AFTERNOON/EVENING DUE TO WEAK
INSTABILITY WITH MUCAPE AOB 300 J/KG.

RAINFALL INTENSITY SHOULD DECREASE PERHAPS AS EARLY AS FRI
EVENING...BUT MORE LIKELY LATE FRI NIGHT AND ESPECIALLY SAT.
HOWEVER...AMPLE MOISTURE CONTINUING ACROSS THE AREA IN COMBINATION
WITH WEAK SYNOPTIC SCALE ASCENT DUE TO THE PRESENCE OF THE UPPER LOW
WILL LEAD TO WIDESPREAD SHOWER COVERAGE. A SLIGHT CHANCE OF
THUNDERSTORMS WILL CONTINUE SAT AFTERNOON DUE TO AN ENVIRONMENT OF
WEAK AOB 300 J/KG MUCAPE. THE UPPER LOW THAT IS PROGGED TO BE
CENTERED OVER THE LOWER COLORADO RIVER VALLEY MIDDAY SAT IS PROGGED
TO MOVE SWD INTO THE NRN GULF OF CALIFORNIA SAT NIGHT...THEN MOVE
SLOWLY SEWD ACROSS SONORA MEXICO SUN. THERE SHOULD BE ENOUGH
MOISTURE TO MAINTAIN A SLIGHT CHANCE OF SHOWERS FROM TUCSON EWD/SWD
SUN.

STORM TOTAL LIQUID AMOUNTS ARE FORECAST TO GENERALLY RANGE FROM 0.50
TO 1.50 INCHES IN THE VALLEYS...WITH SOME AMOUNTS IN EXCESS OF 2.00
INCHES POSSIBLE. LIQUID AMOUNTS ACROSS THE MOUNTAINS WILL GENERALLY
RANGE FROM 1.00 - 2.00 INCHES. HOWEVER...LIQUID AMOUNTS IN EXCESS OF
2 INCHES SHOULD OCCUR ACROSS SOME MOUNTAINS...PARTICULARLY FROM THE
CATALINA/RINCON MOUNTAINS NEAR TUCSON NEWD TO THE WHITE MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EVEN EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-THUR. MUCH COOLER TEMPS
WILL OCCUR FRI AND SAT...WITH HIGH TEMPS ACROSS THE AREA TO AVERAGE
ABOUT 5-10 DEGS F BELOW NORMAL. A WARMING TREND WILL THEN OCCUR
SUN-THUR.

&&

.AVIATION...VALID THRU 31/00Z.
A PACIFIC LOW PRESSURE SYSTEM WILL MOVE EASTWARD INTO SOUTHEAST
ARIZONA INTO FRIDAY. THIS SYSTEM WILL BRING A SIGNIFICANT AMOUNT AND
MOISTURE RESULTING IN WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW.
THERE IS ALSO A SLIGHT CHANCE OF THUNDERSTORMS ACROSS MUCH OF THE
AREA FRIDAY AFTERNOON. CLOUD DECKS EARLY THIS EVENING WILL GENERALLY
BE AT 6-10K FT AGL...THEN LOWER TO GENERALLY 2-3K FT AGL BY FRIDAY
MORNING. HIGHER TERRAIN WILL BE OBSCURED FRIDAY IN CLOUDS AND
PRECIPITATION. SURFACE WIND WILL GENERALLY BE SELY/SLY AT 5-15 KTS
THRU THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT WIDESPREAD VALLEY RAIN AND MOUNTAIN SNOW
TONIGHT INTO SATURDAY. THE MOST SIGNIFICANT SNOWFALL WILL OCCUR
ACROSS THE HIGHEST PEAKS OF THE WHITE MOUNTAINS...MOUNT GRAHAM...AND
THE CATALINA AND RINCON MOUNTAINS NEAR TUCSON. A FEW LINGERING
SHOWERS WILL OCCUR MAINLY EAST TO SOUTH OF TUCSON SUNDAY...THEN DRY
CONDITIONS WILL PREVAIL SUNDAY NIGHT THROUGH THURSDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WARNING FROM 5 AM FRIDAY TO NOON MST SATURDAY FOR
    AZZ510-511 ABOVE 7000 FEET.

    WINTER STORM WARNING FROM 11 AM FRIDAY TO NOON MST SATURDAY FOR
    AZZ514 ABOVE 7000 FEET.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS







000
FXUS65 KTWC 291707
AFDTWC

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE TUCSON AZ
1005 AM MST THU JAN 29 2015

CORRECTED DISCUSSION THIRD PARAGRAPH

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
ESPECIALLY TONIGHT INTO SATURDAY. MINOR FLOODING MAY OCCUR DUE TO
PERIODS OF HEAVY RAINFALL. THE MOST SIGNIFICANT SNOWFALL WILL BE
ABOVE 8000 FEET...OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH COOLER
DAYTIME TEMPERATURES FRIDAY INTO THIS WEEKEND. DRY CONDITIONS WITH A
WARMING TREND WILL THEN OCCUR EARLY NEXT WEEK.

&&

.DISCUSSION...UPPER LEVEL TROUGH WAS WEST OF THE SRN CALIFORNIA/BAJA
CALIFORNIA COASTS WITH 570 DM LOW CENTERED NEAR 27N/123W THIS
MORNING. THIS SYSTEM WILL MOVE EWD INTO THE SWRN CONUS TONIGHT AND
REMAIN QUASI-STATIONARY INTO SAT. ABUNDANT MOISTURE WILL MOVE INTO
THE AREA...WITH TOTAL PRECIP WATER VALUES TO APPROACH 1.20 INCHES BY
SAT. ISOLATED TO SCATTERED SHOWERS PRODUCING MOSTLY SPRINKLES THIS
MORNING WILL BECOME SCATTERED TO NUMEROUS SHOWERS PRODUCING
POTENTIALLY LOCALLY HEAVY RAINFALL TONIGHT AND CONTINUING FRI.
THERE IS A SLIGHT CHANCE OF THUNDERSTORMS FRI AND FRI EVENING DUE
TO WEAK INSTABILITY WITH MUCAPE AOB 300 J/KG.

RAINFALL INTENSITY SHOULD DECREASE PERHAPS AS EARLY AS FRI
AFTERNOON...BUT MORE LIKELY FRI NIGHT AND ESPECIALLY SAT. HOWEVER...
AMPLE MOISTURE CONTINUING ACROSS THE AREA IN COMBINATION WITH WEAK
SYNOPTIC SCALE ASCENT DUE TO THE PRESENCE OF THE UPPER LOW WILL LEAD
TO WIDESPREAD SHOWER COVERAGE. A SLIGHT CHANCE OF THUNDERSTORMS
CONTINUES SAT DUE TO A PROGGED ENVIRONMENT OF WEAK AOB 300 J/KG
MUCAPE. THE UPPER LOW IS PROGGED TO FILL AND MOVE SWD INTO THE NRN
GULF OF CALIFORNIA SAT NIGHT...THEN CONTINUE TO MOVE SLOWLY SEWD
ACROSS SONORA MEXICO SUN. THERE APPEARS TO BE ENOUGH RESIDUAL
MOISTURE TO MAINTAIN A SLIGHT CHANCE OF SHOWERS EAST-TO-SOUTH OF
TUCSON SUN.

STORM TOTAL LIQUID AMOUNTS ARE FORECAST TO GENERALLY RANGE FROM 0.50
TO 1.50 INCHES IN THE VALLEYS...WITH SOME AMOUNTS IN EXCESS OF 2.00
INCHES POSSIBLE. LIQUID AMOUNTS ACROSS THE MOUNTAINS WILL GENERALLY
RANGE FROM 1.00 - 2.00 INCHES. HOWEVER...LIQUID AMOUNTS IN EXCESS OF
2 INCHES SHOULD OCCUR ACROSS SOME MOUNTAINS...PARTICULARLY FROM THE
CATALINA/RINCON MOUNTAINS NEAR TUCSON NEWD TO THE WHITE MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-WED. HIGH TEMPS TODAY
WILL AVERAGE ABOUT 5-10 DEGS F OR SO ABOVE NORMAL. EXPECT ABOUT
10-15 DEGS F OF COOLING FRI FOLLOWED BY SLIGHTLY COOLER TEMPS SAT.
A WARMING TREND WILL THEN OCCUR SUN-MON...THEN NO SIGNIFICANT CHANGE
IN DAYTIME TEMPS WILL HAPPEN TUE-WED.

&&

.AVIATION...VALID THRU 30/18Z.
A STRONG LOW PRESSURE SYSTEM WILL MOVE EASTWARD ACROSS SOUTHEAST
ARIZONA INTO SATURDAY. FLYING CONDITIONS WILL RAPIDLY DETERIORATE
INTO FRIDAY MORNING...WITH CLOUD DECKS MAINLY ABOVE 10K FT AGL THIS
MORNING FOLLOWED BY SCATTERED TO BROKEN CLOUDS AROUND 3-6K FT AGL
AND OVERCAST CLOUD DECKS ABOVE 6K FT AGL BY THIS EVENING. ISOLATED
-SHRA WILL OCCUR INTO THIS AFTERNOON...THEN SCATTERED TO NUMEROUS
-SHRA DEVELOPING THIS EVENING. CIGS AND VSBYS WILL DECREASE EVEN
FURTHER DURING THIS PERIOD WITH AREAS OF MVFR CONDITIONS LIKELY
BEFORE SUNRISE FRIDAY. SURFACE WIND WILL BE SELY/SLY AT 10-15
KTS...WITH THE STRONGEST AND GUSTIEST WINDS ALONG THE NEW MEXICO
BORDER AND ALONG THE GILA RIVER VALLEY. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY TONIGHT INTO SATURDAY. THE MOST SIGNIFICANT
SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE WHITE
MOUNTAINS...MOUNT GRAHAM...AND THE CATALINA AND RINCON MOUNTAINS
NEAR TUCSON. A FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH
OF TUCSON SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH
WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING
    FOR AZZ510-511-514 ABOVE 7000 FEET.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS






000
FXUS65 KTWC 291707
AFDTWC

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE TUCSON AZ
1005 AM MST THU JAN 29 2015

CORRECTED DISCUSSION THIRD PARAGRAPH

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
ESPECIALLY TONIGHT INTO SATURDAY. MINOR FLOODING MAY OCCUR DUE TO
PERIODS OF HEAVY RAINFALL. THE MOST SIGNIFICANT SNOWFALL WILL BE
ABOVE 8000 FEET...OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH COOLER
DAYTIME TEMPERATURES FRIDAY INTO THIS WEEKEND. DRY CONDITIONS WITH A
WARMING TREND WILL THEN OCCUR EARLY NEXT WEEK.

&&

.DISCUSSION...UPPER LEVEL TROUGH WAS WEST OF THE SRN CALIFORNIA/BAJA
CALIFORNIA COASTS WITH 570 DM LOW CENTERED NEAR 27N/123W THIS
MORNING. THIS SYSTEM WILL MOVE EWD INTO THE SWRN CONUS TONIGHT AND
REMAIN QUASI-STATIONARY INTO SAT. ABUNDANT MOISTURE WILL MOVE INTO
THE AREA...WITH TOTAL PRECIP WATER VALUES TO APPROACH 1.20 INCHES BY
SAT. ISOLATED TO SCATTERED SHOWERS PRODUCING MOSTLY SPRINKLES THIS
MORNING WILL BECOME SCATTERED TO NUMEROUS SHOWERS PRODUCING
POTENTIALLY LOCALLY HEAVY RAINFALL TONIGHT AND CONTINUING FRI.
THERE IS A SLIGHT CHANCE OF THUNDERSTORMS FRI AND FRI EVENING DUE
TO WEAK INSTABILITY WITH MUCAPE AOB 300 J/KG.

RAINFALL INTENSITY SHOULD DECREASE PERHAPS AS EARLY AS FRI
AFTERNOON...BUT MORE LIKELY FRI NIGHT AND ESPECIALLY SAT. HOWEVER...
AMPLE MOISTURE CONTINUING ACROSS THE AREA IN COMBINATION WITH WEAK
SYNOPTIC SCALE ASCENT DUE TO THE PRESENCE OF THE UPPER LOW WILL LEAD
TO WIDESPREAD SHOWER COVERAGE. A SLIGHT CHANCE OF THUNDERSTORMS
CONTINUES SAT DUE TO A PROGGED ENVIRONMENT OF WEAK AOB 300 J/KG
MUCAPE. THE UPPER LOW IS PROGGED TO FILL AND MOVE SWD INTO THE NRN
GULF OF CALIFORNIA SAT NIGHT...THEN CONTINUE TO MOVE SLOWLY SEWD
ACROSS SONORA MEXICO SUN. THERE APPEARS TO BE ENOUGH RESIDUAL
MOISTURE TO MAINTAIN A SLIGHT CHANCE OF SHOWERS EAST-TO-SOUTH OF
TUCSON SUN.

STORM TOTAL LIQUID AMOUNTS ARE FORECAST TO GENERALLY RANGE FROM 0.50
TO 1.50 INCHES IN THE VALLEYS...WITH SOME AMOUNTS IN EXCESS OF 2.00
INCHES POSSIBLE. LIQUID AMOUNTS ACROSS THE MOUNTAINS WILL GENERALLY
RANGE FROM 1.00 - 2.00 INCHES. HOWEVER...LIQUID AMOUNTS IN EXCESS OF
2 INCHES SHOULD OCCUR ACROSS SOME MOUNTAINS...PARTICULARLY FROM THE
CATALINA/RINCON MOUNTAINS NEAR TUCSON NEWD TO THE WHITE MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-WED. HIGH TEMPS TODAY
WILL AVERAGE ABOUT 5-10 DEGS F OR SO ABOVE NORMAL. EXPECT ABOUT
10-15 DEGS F OF COOLING FRI FOLLOWED BY SLIGHTLY COOLER TEMPS SAT.
A WARMING TREND WILL THEN OCCUR SUN-MON...THEN NO SIGNIFICANT CHANGE
IN DAYTIME TEMPS WILL HAPPEN TUE-WED.

&&

.AVIATION...VALID THRU 30/18Z.
A STRONG LOW PRESSURE SYSTEM WILL MOVE EASTWARD ACROSS SOUTHEAST
ARIZONA INTO SATURDAY. FLYING CONDITIONS WILL RAPIDLY DETERIORATE
INTO FRIDAY MORNING...WITH CLOUD DECKS MAINLY ABOVE 10K FT AGL THIS
MORNING FOLLOWED BY SCATTERED TO BROKEN CLOUDS AROUND 3-6K FT AGL
AND OVERCAST CLOUD DECKS ABOVE 6K FT AGL BY THIS EVENING. ISOLATED
-SHRA WILL OCCUR INTO THIS AFTERNOON...THEN SCATTERED TO NUMEROUS
-SHRA DEVELOPING THIS EVENING. CIGS AND VSBYS WILL DECREASE EVEN
FURTHER DURING THIS PERIOD WITH AREAS OF MVFR CONDITIONS LIKELY
BEFORE SUNRISE FRIDAY. SURFACE WIND WILL BE SELY/SLY AT 10-15
KTS...WITH THE STRONGEST AND GUSTIEST WINDS ALONG THE NEW MEXICO
BORDER AND ALONG THE GILA RIVER VALLEY. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY TONIGHT INTO SATURDAY. THE MOST SIGNIFICANT
SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE WHITE
MOUNTAINS...MOUNT GRAHAM...AND THE CATALINA AND RINCON MOUNTAINS
NEAR TUCSON. A FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH
OF TUCSON SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH
WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING
    FOR AZZ510-511-514 ABOVE 7000 FEET.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS







000
FXUS65 KTWC 291700
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1000 AM MST THU JAN 29 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
ESPECIALLY TONIGHT INTO SATURDAY. MINOR FLOODING MAY OCCUR DUE TO
PERIODS OF HEAVY RAINFALL. THE MOST SIGNIFICANT SNOWFALL WILL BE
ABOVE 8000 FEET...OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH COOLER
DAYTIME TEMPERATURES FRIDAY INTO THIS WEEKEND. DRY CONDITIONS WITH A
WARMING TREND WILL THEN OCCUR EARLY NEXT WEEK.

&&

.DISCUSSION...UPPER LEVEL TROUGH WAS WEST OF THE SRN CALIFORNIA/BAJA
CALIFORNIA COASTS WITH 570 DM LOW CENTERED NEAR 27N/123W THIS
MORNING. THIS SYSTEM WILL MOVE EWD INTO THE SWRN CONUS TONIGHT AND
REMAIN QUASI-STATIONARY INTO SAT. ABUNDANT MOISTURE WILL MOVE INTO
THE AREA...WITH TOTAL PRECIP WATER VALUES TO APPROACH 1.20 INCHES BY
SAT. ISOLATED TO SCATTERED SHOWERS PRODUCING MOSTLY SPRINKLES THIS
MORNING WILL BECOME SCATTERED TO NUMEROUS SHOWERS PRODUCING
POTENTIALLY LOCALLY HEAVY RAINFALL TONIGHT AND CONTINUING FRI.
THERE IS A SLIGHT CHANCE OF THUNDERSTORMS FRI AND FRI EVENING DUE
TO WEAK INSTABILITY WITH MUCAPE AOB 300 J/KG.

RAINFALL INTENSITY SHOULD DECREASE PERHAPS AS EARLY AS FRI
AFTERNOON...BUT MORE LIKELY FRI NIGHT AND ESPECIALLY SAT. HOWEVER...
AMPLE MOISTURE CONTINUING ACROSS THE AREA IN COMBINATION WITH WEAK
SYNOPTIC SCALE ASCENT DUE TO THE PRESENCE OF THE UPPER LOW WILL LEAD
TO WIDESPREAD SHOWER COVERAGE. A SLIGHT CHANCE OF THUNDERSTORMS
CONTINUES SAT DUE TO A PROGGED ENVIRONMENT OF WEAK AOB 300 J/KG
MUCAPE. THE UPPER LOW IS PROGGED TO FILL AND MOVE SWD INTO THE NRN
GULF OF CALIFORNIA SAT NIGHT...THEN CONTINUE TO MOVE SLOWLY SEWD
ACROSS SONORA MEXICO SUN. THERE APPEARS TO BE ENOUGH RESIDUAL
MOISTURE TO MAINTAIN A SLIGHT CHANCE OF SHOWERS EAST-TO-SOUTH OF
TUCSON SUN.

STORM TOTAL LIQUID AMOUNTS ARE FORECAST TO GENERALLY RANGE FROM 0.50
TO 1.50 INCHES IN THE VALLEYS...WITH AMOUNTS GENERALLY FROM 1.00 -
2.00 INCHES ACROSS THE MOUNTAINS. HOWEVER...LIQUID AMOUNTS IN EXCESS
OF 2 INCHES SHOULD OCCUR ACROSS SOME MOUNTAINS...PARTICULARLY FROM
THE CATALINA/RINCON MOUNTAINS NEAR TUCSON NEWD TO THE WHITE
MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-WED. HIGH TEMPS TODAY
WILL AVERAGE ABOUT 5-10 DEGS F OR SO ABOVE NORMAL. EXPECT ABOUT
10-15 DEGS F OF COOLING FRI FOLLOWED BY SLIGHTLY COOLER TEMPS SAT.
A WARMING TREND WILL THEN OCCUR SUN-MON...THEN NO SIGNIFICANT CHANGE
IN DAYTIME TEMPS WILL HAPPEN TUE-WED.

&&

.AVIATION...VALID THRU 30/18Z.
A STRONG LOW PRESSURE SYSTEM WILL MOVE EASTWARD ACROSS SOUTHEAST
ARIZONA INTO SATURDAY. FLYING CONDITIONS WILL RAPIDLY DETERIORATE
INTO FRIDAY MORNING...WITH CLOUD DECKS MAINLY ABOVE 10K FT AGL THIS
MORNING FOLLOWED BY SCATTERED TO BROKEN CLOUDS AROUND 3-6K FT AGL
AND OVERCAST CLOUD DECKS ABOVE 6K FT AGL BY THIS EVENING. ISOLATED
-SHRA WILL OCCUR INTO THIS AFTERNOON...THEN SCATTERED TO NUMEROUS
-SHRA DEVELOPING THIS EVENING. CIGS AND VSBYS WILL DECREASE EVEN
FURTHER DURING THIS PERIOD WITH AREAS OF MVFR CONDITIONS LIKELY
BEFORE SUNRISE FRIDAY. SURFACE WIND WILL BE SELY/SLY AT 10-15
KTS...WITH THE STRONGEST AND GUSTIEST WINDS ALONG THE NEW MEXICO
BORDER AND ALONG THE GILA RIVER VALLEY. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY TONIGHT INTO SATURDAY. THE MOST SIGNIFICANT
SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE WHITE
MOUNTAINS...MOUNT GRAHAM...AND THE CATALINA AND RINCON MOUNTAINS
NEAR TUCSON. A FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH
OF TUCSON SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH
WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING
    FOR AZZ510-511-514 ABOVE 7000 FEET.

&&

$$

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FRANCIS







000
FXUS65 KTWC 291700
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1000 AM MST THU JAN 29 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
ESPECIALLY TONIGHT INTO SATURDAY. MINOR FLOODING MAY OCCUR DUE TO
PERIODS OF HEAVY RAINFALL. THE MOST SIGNIFICANT SNOWFALL WILL BE
ABOVE 8000 FEET...OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH COOLER
DAYTIME TEMPERATURES FRIDAY INTO THIS WEEKEND. DRY CONDITIONS WITH A
WARMING TREND WILL THEN OCCUR EARLY NEXT WEEK.

&&

.DISCUSSION...UPPER LEVEL TROUGH WAS WEST OF THE SRN CALIFORNIA/BAJA
CALIFORNIA COASTS WITH 570 DM LOW CENTERED NEAR 27N/123W THIS
MORNING. THIS SYSTEM WILL MOVE EWD INTO THE SWRN CONUS TONIGHT AND
REMAIN QUASI-STATIONARY INTO SAT. ABUNDANT MOISTURE WILL MOVE INTO
THE AREA...WITH TOTAL PRECIP WATER VALUES TO APPROACH 1.20 INCHES BY
SAT. ISOLATED TO SCATTERED SHOWERS PRODUCING MOSTLY SPRINKLES THIS
MORNING WILL BECOME SCATTERED TO NUMEROUS SHOWERS PRODUCING
POTENTIALLY LOCALLY HEAVY RAINFALL TONIGHT AND CONTINUING FRI.
THERE IS A SLIGHT CHANCE OF THUNDERSTORMS FRI AND FRI EVENING DUE
TO WEAK INSTABILITY WITH MUCAPE AOB 300 J/KG.

RAINFALL INTENSITY SHOULD DECREASE PERHAPS AS EARLY AS FRI
AFTERNOON...BUT MORE LIKELY FRI NIGHT AND ESPECIALLY SAT. HOWEVER...
AMPLE MOISTURE CONTINUING ACROSS THE AREA IN COMBINATION WITH WEAK
SYNOPTIC SCALE ASCENT DUE TO THE PRESENCE OF THE UPPER LOW WILL LEAD
TO WIDESPREAD SHOWER COVERAGE. A SLIGHT CHANCE OF THUNDERSTORMS
CONTINUES SAT DUE TO A PROGGED ENVIRONMENT OF WEAK AOB 300 J/KG
MUCAPE. THE UPPER LOW IS PROGGED TO FILL AND MOVE SWD INTO THE NRN
GULF OF CALIFORNIA SAT NIGHT...THEN CONTINUE TO MOVE SLOWLY SEWD
ACROSS SONORA MEXICO SUN. THERE APPEARS TO BE ENOUGH RESIDUAL
MOISTURE TO MAINTAIN A SLIGHT CHANCE OF SHOWERS EAST-TO-SOUTH OF
TUCSON SUN.

STORM TOTAL LIQUID AMOUNTS ARE FORECAST TO GENERALLY RANGE FROM 0.50
TO 1.50 INCHES IN THE VALLEYS...WITH AMOUNTS GENERALLY FROM 1.00 -
2.00 INCHES ACROSS THE MOUNTAINS. HOWEVER...LIQUID AMOUNTS IN EXCESS
OF 2 INCHES SHOULD OCCUR ACROSS SOME MOUNTAINS...PARTICULARLY FROM
THE CATALINA/RINCON MOUNTAINS NEAR TUCSON NEWD TO THE WHITE
MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-WED. HIGH TEMPS TODAY
WILL AVERAGE ABOUT 5-10 DEGS F OR SO ABOVE NORMAL. EXPECT ABOUT
10-15 DEGS F OF COOLING FRI FOLLOWED BY SLIGHTLY COOLER TEMPS SAT.
A WARMING TREND WILL THEN OCCUR SUN-MON...THEN NO SIGNIFICANT CHANGE
IN DAYTIME TEMPS WILL HAPPEN TUE-WED.

&&

.AVIATION...VALID THRU 30/18Z.
A STRONG LOW PRESSURE SYSTEM WILL MOVE EASTWARD ACROSS SOUTHEAST
ARIZONA INTO SATURDAY. FLYING CONDITIONS WILL RAPIDLY DETERIORATE
INTO FRIDAY MORNING...WITH CLOUD DECKS MAINLY ABOVE 10K FT AGL THIS
MORNING FOLLOWED BY SCATTERED TO BROKEN CLOUDS AROUND 3-6K FT AGL
AND OVERCAST CLOUD DECKS ABOVE 6K FT AGL BY THIS EVENING. ISOLATED
-SHRA WILL OCCUR INTO THIS AFTERNOON...THEN SCATTERED TO NUMEROUS
-SHRA DEVELOPING THIS EVENING. CIGS AND VSBYS WILL DECREASE EVEN
FURTHER DURING THIS PERIOD WITH AREAS OF MVFR CONDITIONS LIKELY
BEFORE SUNRISE FRIDAY. SURFACE WIND WILL BE SELY/SLY AT 10-15
KTS...WITH THE STRONGEST AND GUSTIEST WINDS ALONG THE NEW MEXICO
BORDER AND ALONG THE GILA RIVER VALLEY. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY TONIGHT INTO SATURDAY. THE MOST SIGNIFICANT
SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE WHITE
MOUNTAINS...MOUNT GRAHAM...AND THE CATALINA AND RINCON MOUNTAINS
NEAR TUCSON. A FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH
OF TUCSON SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH
WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING
    FOR AZZ510-511-514 ABOVE 7000 FEET.

&&

$$

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FRANCIS






000
FXUS65 KTWC 290951
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
251 AM MST THU JAN 29 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST SIGNIFICANT SNOWFALL
WILL BE ABOVE 8000 FEET OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH
COOLER DAYTIME TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL
RETURN EARLY NEXT WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...SURFACE RIDGING WILL SETTLE IN OVER THE PLAINS TODAY.
THIS WILL TIGHTEN THE PRESSURE GRADIENT OUT EAST...WHICH WILL
ELEVATE WINDS THIS AFTERNOON...ESPECIALLY OVER THE GILA RIVER AND
SAN SIMON VALLEYS. THIS PRESSURE GRADIENT WILL GENERALLY STAY IN
PLACE UNTIL FRIDAY EVENING...SO WINDS WILL LIKELY REMAIN ELEVATED
THROUGH THIS TIME AS WELL.

DURING THE SAME TIME PERIOD THE UPPER LEVEL TROUGH OFF THE BAJA
COAST THIS MORNING WILL DEEPEN AND MOVE ONSHORE. THE CENTER OF THE
LOW IS PROGGED TO BE OVER SOUTHERN CALIFORNIA BY FRIDAY EVENING.
THIS TRAJECTORY VERY GOOD FOR DEEP MOISTURE ADVECTION FOR THE
AREA...AS HAS BEEN ADVERTISED FOR SEVERAL DAYS.

GUIDANCE HAS CONTINUED TO SHOW SOME INSTABILITY FRIDAY AND
SATURDAY DURING DAYLIGHT HOURS. THIS ENHANCES THE UNCERTAINTY
WITH RESPECT TO QPF AND SNOW TOTALS...ESPECIALLY ACROSS THE
SOUTHERN TIER OF ZONES. NEVERTHELESS...EXPECT WIDESPREAD 1-2
INCHES OF TOTAL LIQUID TO BE MEASURED ACROSS MOST LOCATIONS
THROUGHOUT THE EVENT...WITH LOCALLY HEAVIER AMOUNTS POSSIBLE.

ACROSS THE HIGHER TERRAIN OF THE WHITE MOUNTAINS EXPECT
PRECIPITATION TYPE TO QUICKLY BE DOMINATED BY SNOW. OTHER
LOCATIONS WILL HAVE TO WAIT FOR SNOW LEVELS TO BEGIN TO FALL.
INITIALLY...SNOW LEVELS WILL BE AROUND 9000 FT...THOUGH BY LATE
FRIDAY EXPECT THEM TO BE MORE AROUND 8000 FT. FOR THIS REASON HAVE
DELAYED THE START OFF SNOW FOR THE SANTA CATALINA MOUNTAINS BY
6 HOURS COMPARED TO THE PINALENO AND WHITE MOUNTAINS. THAT BEING
SAID...IF A CONVECTIVELY ENHANCED SHOWER MOVES IN EARLY FRIDAY
LOCALIZED SNOW CAN/T BE RULED OUT...THOUGH CONFIDENCE REMAINS TOO
LOW TO MENTION AT THIS TIME.

FRIDAY EVENING THE AFOREMENTIONED TROUGH WILL BEGIN TO DIG SOUTH
WHILE LIFTING...WHICH WILL ALLOW THE INTENSITY OF THE SHOWERS TO
RELAX FOR THE MOST PART. THOUGH...STILL EXPECTING WIDESPREAD
SHOWERS ACROSS THE AREA INTO SATURDAY.

BY SATURDAY EVENING THE TROUGH AXIS IS EXPECTED TO SPAN FROM
CENTRAL GULF OF CALIFORNIA INTO NORTHEASTERN NEW MEXICO.
SO...EXPECT SHOWER ACTIVITY TO BEGIN TO DIMINISH FROM NORTHWEST TO
SOUTHEAST THROUGH SUNDAY EVENING WHEN TROUGH REACHES SOUTHERN
BAJA. THIS WILL ALLOW FOR UPPER LEVEL RIDGING TO SLIDE OVERHEAD BY
THE END OF THE FORECAST.

SNOW TOTALS THROUGHOUT THE EVENT COULD REACH TWO FEET FOR THE
WHITE MOUNTAINS AND NEAR THAT MUCH FOR THE PINALENO MOUNTAINS /MT
GRAHAM. AS FOR THE SANTA CATALINA MOUNTAINS AND MORE SPECIFICALLY
MT. LEMMON EXPECT AROUND A FOOT. AGAIN THERE IS POTENTIAL FOR
HIGHER TOTALS WITH CONVECTION.

&&

.AVIATION...VALID THRU 30/12Z.
AS A STRONG LOW PRESSURE SYSTEM...WHICH IS CURRENTLY JUST OFF THE
CALIFORNIA COAST MAKES ITS WAY EASTWARD OVER THE NEXT FEW DAYS...
FLYING CONDITIONS WILL RAPIDLY DETERIORATE WITH INCREASING CLOUDS
MAINLY ABOVE 12K FT AGL EARLY THIS MORNING FOLLOWED BY FEW TO
SCATTERED CLOUDS AROUND 6-10K FT AGL AND OVERCAST CLOUD DECKS ABOVE
12K FT AGL BY THIS EVENING. A FEW -SHRA MAY DEVELOP EAST AND SOUTH
OF KTUS THIS AFTERNOON...WITH SCT TO NMRS -SHRA DEVELOPING AFTER
AROUND 30/06Z. CIGS AND VSBYS WILL DECREASE EVEN FURTHER DURING THIS
PERIOD WITH MVFR CONDITIONS POSSIBLE IN SOME LOCATIONS BEFORE
SUNRISE FRIDAY. SURFACE WIND WILL BE MOSTLY LESS THAN 12 KTS THIS
MORNING...THEN BECOMING SELY/SLY AT 10-15 KTS THIS AFTERNOON WITH
THE STRONGEST AND GUSTIEST WINDS ALONG THE NEW MEXICO BORDER AND
ALONG THE GILA RIVER VALLEY. WINDS WILL REMAIN FROM THE SOUTHEAST
OVERNIGHT INTO EARLY FRIDAY...ESPECIALLY ALONG THE NEW MEXICO BORDER
AND GILA RIVER VALLEY WHERE WINDS WILL BE SUSTAINED AT 15 TO 20 MPH
WITH HIGHER GUSTS DURING THE LATE EVENING AND OVERNIGHT HOURS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY TONIGHT INTO SATURDAY. THE MOST SIGNIFICANT
SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE WHITE
MOUNTAINS...MOUNT GRAHAM AND THE CATALINA AND RINCON MOUNTAINS. A
FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH OF TUCSON
SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING
FOR AZZ510-511-514.

&&

$$

DISCUSSION...MEADOWS
FIRE WEATHER/AVIATION...88

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000
FXUS65 KTWC 290951
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
251 AM MST THU JAN 29 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST SIGNIFICANT SNOWFALL
WILL BE ABOVE 8000 FEET OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH
COOLER DAYTIME TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL
RETURN EARLY NEXT WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...SURFACE RIDGING WILL SETTLE IN OVER THE PLAINS TODAY.
THIS WILL TIGHTEN THE PRESSURE GRADIENT OUT EAST...WHICH WILL
ELEVATE WINDS THIS AFTERNOON...ESPECIALLY OVER THE GILA RIVER AND
SAN SIMON VALLEYS. THIS PRESSURE GRADIENT WILL GENERALLY STAY IN
PLACE UNTIL FRIDAY EVENING...SO WINDS WILL LIKELY REMAIN ELEVATED
THROUGH THIS TIME AS WELL.

DURING THE SAME TIME PERIOD THE UPPER LEVEL TROUGH OFF THE BAJA
COAST THIS MORNING WILL DEEPEN AND MOVE ONSHORE. THE CENTER OF THE
LOW IS PROGGED TO BE OVER SOUTHERN CALIFORNIA BY FRIDAY EVENING.
THIS TRAJECTORY VERY GOOD FOR DEEP MOISTURE ADVECTION FOR THE
AREA...AS HAS BEEN ADVERTISED FOR SEVERAL DAYS.

GUIDANCE HAS CONTINUED TO SHOW SOME INSTABILITY FRIDAY AND
SATURDAY DURING DAYLIGHT HOURS. THIS ENHANCES THE UNCERTAINTY
WITH RESPECT TO QPF AND SNOW TOTALS...ESPECIALLY ACROSS THE
SOUTHERN TIER OF ZONES. NEVERTHELESS...EXPECT WIDESPREAD 1-2
INCHES OF TOTAL LIQUID TO BE MEASURED ACROSS MOST LOCATIONS
THROUGHOUT THE EVENT...WITH LOCALLY HEAVIER AMOUNTS POSSIBLE.

ACROSS THE HIGHER TERRAIN OF THE WHITE MOUNTAINS EXPECT
PRECIPITATION TYPE TO QUICKLY BE DOMINATED BY SNOW. OTHER
LOCATIONS WILL HAVE TO WAIT FOR SNOW LEVELS TO BEGIN TO FALL.
INITIALLY...SNOW LEVELS WILL BE AROUND 9000 FT...THOUGH BY LATE
FRIDAY EXPECT THEM TO BE MORE AROUND 8000 FT. FOR THIS REASON HAVE
DELAYED THE START OFF SNOW FOR THE SANTA CATALINA MOUNTAINS BY
6 HOURS COMPARED TO THE PINALENO AND WHITE MOUNTAINS. THAT BEING
SAID...IF A CONVECTIVELY ENHANCED SHOWER MOVES IN EARLY FRIDAY
LOCALIZED SNOW CAN/T BE RULED OUT...THOUGH CONFIDENCE REMAINS TOO
LOW TO MENTION AT THIS TIME.

FRIDAY EVENING THE AFOREMENTIONED TROUGH WILL BEGIN TO DIG SOUTH
WHILE LIFTING...WHICH WILL ALLOW THE INTENSITY OF THE SHOWERS TO
RELAX FOR THE MOST PART. THOUGH...STILL EXPECTING WIDESPREAD
SHOWERS ACROSS THE AREA INTO SATURDAY.

BY SATURDAY EVENING THE TROUGH AXIS IS EXPECTED TO SPAN FROM
CENTRAL GULF OF CALIFORNIA INTO NORTHEASTERN NEW MEXICO.
SO...EXPECT SHOWER ACTIVITY TO BEGIN TO DIMINISH FROM NORTHWEST TO
SOUTHEAST THROUGH SUNDAY EVENING WHEN TROUGH REACHES SOUTHERN
BAJA. THIS WILL ALLOW FOR UPPER LEVEL RIDGING TO SLIDE OVERHEAD BY
THE END OF THE FORECAST.

SNOW TOTALS THROUGHOUT THE EVENT COULD REACH TWO FEET FOR THE
WHITE MOUNTAINS AND NEAR THAT MUCH FOR THE PINALENO MOUNTAINS /MT
GRAHAM. AS FOR THE SANTA CATALINA MOUNTAINS AND MORE SPECIFICALLY
MT. LEMMON EXPECT AROUND A FOOT. AGAIN THERE IS POTENTIAL FOR
HIGHER TOTALS WITH CONVECTION.

&&

.AVIATION...VALID THRU 30/12Z.
AS A STRONG LOW PRESSURE SYSTEM...WHICH IS CURRENTLY JUST OFF THE
CALIFORNIA COAST MAKES ITS WAY EASTWARD OVER THE NEXT FEW DAYS...
FLYING CONDITIONS WILL RAPIDLY DETERIORATE WITH INCREASING CLOUDS
MAINLY ABOVE 12K FT AGL EARLY THIS MORNING FOLLOWED BY FEW TO
SCATTERED CLOUDS AROUND 6-10K FT AGL AND OVERCAST CLOUD DECKS ABOVE
12K FT AGL BY THIS EVENING. A FEW -SHRA MAY DEVELOP EAST AND SOUTH
OF KTUS THIS AFTERNOON...WITH SCT TO NMRS -SHRA DEVELOPING AFTER
AROUND 30/06Z. CIGS AND VSBYS WILL DECREASE EVEN FURTHER DURING THIS
PERIOD WITH MVFR CONDITIONS POSSIBLE IN SOME LOCATIONS BEFORE
SUNRISE FRIDAY. SURFACE WIND WILL BE MOSTLY LESS THAN 12 KTS THIS
MORNING...THEN BECOMING SELY/SLY AT 10-15 KTS THIS AFTERNOON WITH
THE STRONGEST AND GUSTIEST WINDS ALONG THE NEW MEXICO BORDER AND
ALONG THE GILA RIVER VALLEY. WINDS WILL REMAIN FROM THE SOUTHEAST
OVERNIGHT INTO EARLY FRIDAY...ESPECIALLY ALONG THE NEW MEXICO BORDER
AND GILA RIVER VALLEY WHERE WINDS WILL BE SUSTAINED AT 15 TO 20 MPH
WITH HIGHER GUSTS DURING THE LATE EVENING AND OVERNIGHT HOURS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY TONIGHT INTO SATURDAY. THE MOST SIGNIFICANT
SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE WHITE
MOUNTAINS...MOUNT GRAHAM AND THE CATALINA AND RINCON MOUNTAINS. A
FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH OF TUCSON
SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING
FOR AZZ510-511-514.

&&

$$

DISCUSSION...MEADOWS
FIRE WEATHER/AVIATION...88

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON








000
FXUS65 KTWC 290332
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
831 PM MST WED JAN 28 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST SIGNIFICANT SNOWFALL
WILL BE ABOVE 8000 FEET OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH
COOLER DAYTIME TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL
RETURN EARLY NEXT WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...LATEST MODELS WERE STILL POINTING TO A SIGNIFICANT
RAIN AND MOUNTAIN SNOW EVENT DEVELOPING LATE THURSDAY INTO
FRIDAY...WITH PERIODS OF PRECIPITATION CONTINUING INTO SATURDAY.
CANNOT RULE OUT A THUNDERSTORM OR TWO ON FRIDAY AS WELL. THE CURRENT
FORECAST LOOKED ON TRACK...SO NO NEED FOR AN UPDATE THIS EVENING.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 30/06Z.
EXPECT INCREASING CLOUDS MAINLY ABOVE 12K FT AGL TONIGHT FOLLOWED BY
A FEW TO SCATTERED CLOUDS AROUND 6-10K FT AGL AND OVERCAST CLOUD
DECKS ABOVE 12K FT AGL BY THURSDAY EVENING. A FEW -SHRA MAY DEVELOP
EAST AND SOUTH OF KTUS THURSDAY AFTERNOON. SURFACE WIND WILL BE LESS
THAN 10 KTS INTO THURSDAY MORNING...THEN SURFACE WIND THURSDAY
AFTERNOON WILL BE SELY/SLY AT 10-15 KTS THURSDAY AFTERNOON. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST
SIGNIFICANT SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE
WHITE MOUNTAINS...MOUNT GRAHAM AND THE CATALINA AND RINCON
MOUNTAINS. A FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH
OF TUCSON SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH
WEDNESDAY.

&&

.PREV DISCUSSION...UPPER LEVEL TROUGH CONTINUES TO DEEPEN WEST OF
THE SRN CALIFORNIA/BAJA CALIFORNIA COASTS VICINITY 125W THIS
AFTERNOON. IR SATELLITE IMAGERY DEPICTED AN EXPANSIVE AREA OF COLDER
CLOUD TOPS EXTENDING FROM FAR SWRN AZ SWWD TO NEAR 20N/120W. EXPECT
THICKENING MOSTLY MID AND HIGH-LEVEL CLOUDS TONIGHT INTO THUR
MORNING AHEAD OF THE DEEPENING UPPER TROUGH. THERE IS A SLIGHT
CHANCE OF SHOWERS THUR AFTERNOON EAST AND SOUTH OF TUCSON WITH DRY
CONDITIONS ELSEWHERE.

28/12Z NAM/GFS/ECMWF/CMC REMAIN CONSISTENT WITH DEPICTING WIDESPREAD
SHOWERS TO DEVELOP THUR EVENING...THEN WIDESPREAD SHOWERS SHOULD
OCCUR THUR NIGHT INTO SAT. THE MAIN ADJUSTMENT FOR THIS FORECAST
PACKAGE WAS TO INCREASE POPS VERSUS THE PREVIOUS OFFICIAL FORECAST.
OTHERWISE...QPF/S AND SNOW ACCUMULATIONS WERE LEFT ESSENTIALLY
UNCHANGED. A SLIGHT CHANCE OF THUNDERSTORMS WAS ADDED TO MUCH OF THE
AREA FRI MORNING...AND A SLIGHT CHANCE OF THUNDERSTORMS IS NOW IN
THE OFFICIAL FORECAST SAT AFTERNOON EXCEPT ACROSS THE WHITE
MOUNTAINS.

A 563 DM LOW IS PROGGED TO BE CENTERED MIDDAY FRI JUST SOUTH OF SAN
DIEGO CALIF...THEN THIS UPPER LOW IS PROGGED TO ESSENTIALLY REMAIN
QUASI-STATIONARY OVER SRN CALIFORNIA/NRN BAJA CALIFORNIA THRU MIDDAY
SAT. 28/12Z GFS TOTAL PRECIP WATER VALUE FOR THIS PERIOD IS PROGGED
TO BE ABOUT 1.20 INCHES. THIS PWAT VALUE IS NOW GREATER THAN 4
STANDARD DEVIATIONS ABOVE NORMAL. THE COMBINATION OF ABUNDANT
MOISTURE AND SYNOPTIC SCALE FORCING SHOULD PRODUCE WIDESPREAD
SIGNIFICANT RAINFALL BY MIDDAY SAT. THE UPPER LOW IS THEN PROGGED TO
FILL AND MOVE SEWD INTO SONORA MEXICO SAT NIGHT...THEN CONTINUE WELL
SOUTH OF THE AREA BY SUN EVENING. THERE APPEARS TO BE ENOUGH
RESIDUAL MOISTURE TO JUSTIFY A SLIGHT CHANCE OF SHOWERS EAST-TO-
SOUTH OF TUCSON SUN.

STORM TOTAL LIQUID AMOUNTS ARE NOW FORECAST TO GENERALLY RANGE FROM
0.50 TO 1.50 INCHES IN THE VALLEYS...WITH LOCALLY HEAVIER AMOUNTS
POSSIBLE. LIQUID AMOUNTS IN EXCESS OF 2 INCHES SHOULD OCCUR ACROSS
THE MOUNTAINS...ESPECIALLY NE OF TUCSON TO THE WHITE MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-WED. HIGH TEMPS THUR WILL
AVERAGE ABOUT 5-10 DEGS F OR SO ABOVE NORMAL. EXPECT NEARLY 10-15
DEGS F OF COOLING FRI FOLLOWED BY AN ADDITIONAL 3-5 DEGS F OF
COOLING SAT. A WARMING TREND WILL OCCUR SUN-MON...THEN NO
SIGNIFICANT CHANGE IN DAYTIME TEMPS WILL HAPPEN TUE-WED.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH SATURDAY
    MORNING FOR AZZ510-511-514 ABOVE 7000 FEET.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS










000
FXUS65 KTWC 290332
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
831 PM MST WED JAN 28 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST SIGNIFICANT SNOWFALL
WILL BE ABOVE 8000 FEET OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH
COOLER DAYTIME TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL
RETURN EARLY NEXT WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...LATEST MODELS WERE STILL POINTING TO A SIGNIFICANT
RAIN AND MOUNTAIN SNOW EVENT DEVELOPING LATE THURSDAY INTO
FRIDAY...WITH PERIODS OF PRECIPITATION CONTINUING INTO SATURDAY.
CANNOT RULE OUT A THUNDERSTORM OR TWO ON FRIDAY AS WELL. THE CURRENT
FORECAST LOOKED ON TRACK...SO NO NEED FOR AN UPDATE THIS EVENING.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 30/06Z.
EXPECT INCREASING CLOUDS MAINLY ABOVE 12K FT AGL TONIGHT FOLLOWED BY
A FEW TO SCATTERED CLOUDS AROUND 6-10K FT AGL AND OVERCAST CLOUD
DECKS ABOVE 12K FT AGL BY THURSDAY EVENING. A FEW -SHRA MAY DEVELOP
EAST AND SOUTH OF KTUS THURSDAY AFTERNOON. SURFACE WIND WILL BE LESS
THAN 10 KTS INTO THURSDAY MORNING...THEN SURFACE WIND THURSDAY
AFTERNOON WILL BE SELY/SLY AT 10-15 KTS THURSDAY AFTERNOON. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST
SIGNIFICANT SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE
WHITE MOUNTAINS...MOUNT GRAHAM AND THE CATALINA AND RINCON
MOUNTAINS. A FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH
OF TUCSON SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH
WEDNESDAY.

&&

.PREV DISCUSSION...UPPER LEVEL TROUGH CONTINUES TO DEEPEN WEST OF
THE SRN CALIFORNIA/BAJA CALIFORNIA COASTS VICINITY 125W THIS
AFTERNOON. IR SATELLITE IMAGERY DEPICTED AN EXPANSIVE AREA OF COLDER
CLOUD TOPS EXTENDING FROM FAR SWRN AZ SWWD TO NEAR 20N/120W. EXPECT
THICKENING MOSTLY MID AND HIGH-LEVEL CLOUDS TONIGHT INTO THUR
MORNING AHEAD OF THE DEEPENING UPPER TROUGH. THERE IS A SLIGHT
CHANCE OF SHOWERS THUR AFTERNOON EAST AND SOUTH OF TUCSON WITH DRY
CONDITIONS ELSEWHERE.

28/12Z NAM/GFS/ECMWF/CMC REMAIN CONSISTENT WITH DEPICTING WIDESPREAD
SHOWERS TO DEVELOP THUR EVENING...THEN WIDESPREAD SHOWERS SHOULD
OCCUR THUR NIGHT INTO SAT. THE MAIN ADJUSTMENT FOR THIS FORECAST
PACKAGE WAS TO INCREASE POPS VERSUS THE PREVIOUS OFFICIAL FORECAST.
OTHERWISE...QPF/S AND SNOW ACCUMULATIONS WERE LEFT ESSENTIALLY
UNCHANGED. A SLIGHT CHANCE OF THUNDERSTORMS WAS ADDED TO MUCH OF THE
AREA FRI MORNING...AND A SLIGHT CHANCE OF THUNDERSTORMS IS NOW IN
THE OFFICIAL FORECAST SAT AFTERNOON EXCEPT ACROSS THE WHITE
MOUNTAINS.

A 563 DM LOW IS PROGGED TO BE CENTERED MIDDAY FRI JUST SOUTH OF SAN
DIEGO CALIF...THEN THIS UPPER LOW IS PROGGED TO ESSENTIALLY REMAIN
QUASI-STATIONARY OVER SRN CALIFORNIA/NRN BAJA CALIFORNIA THRU MIDDAY
SAT. 28/12Z GFS TOTAL PRECIP WATER VALUE FOR THIS PERIOD IS PROGGED
TO BE ABOUT 1.20 INCHES. THIS PWAT VALUE IS NOW GREATER THAN 4
STANDARD DEVIATIONS ABOVE NORMAL. THE COMBINATION OF ABUNDANT
MOISTURE AND SYNOPTIC SCALE FORCING SHOULD PRODUCE WIDESPREAD
SIGNIFICANT RAINFALL BY MIDDAY SAT. THE UPPER LOW IS THEN PROGGED TO
FILL AND MOVE SEWD INTO SONORA MEXICO SAT NIGHT...THEN CONTINUE WELL
SOUTH OF THE AREA BY SUN EVENING. THERE APPEARS TO BE ENOUGH
RESIDUAL MOISTURE TO JUSTIFY A SLIGHT CHANCE OF SHOWERS EAST-TO-
SOUTH OF TUCSON SUN.

STORM TOTAL LIQUID AMOUNTS ARE NOW FORECAST TO GENERALLY RANGE FROM
0.50 TO 1.50 INCHES IN THE VALLEYS...WITH LOCALLY HEAVIER AMOUNTS
POSSIBLE. LIQUID AMOUNTS IN EXCESS OF 2 INCHES SHOULD OCCUR ACROSS
THE MOUNTAINS...ESPECIALLY NE OF TUCSON TO THE WHITE MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-WED. HIGH TEMPS THUR WILL
AVERAGE ABOUT 5-10 DEGS F OR SO ABOVE NORMAL. EXPECT NEARLY 10-15
DEGS F OF COOLING FRI FOLLOWED BY AN ADDITIONAL 3-5 DEGS F OF
COOLING SAT. A WARMING TREND WILL OCCUR SUN-MON...THEN NO
SIGNIFICANT CHANGE IN DAYTIME TEMPS WILL HAPPEN TUE-WED.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH SATURDAY
    MORNING FOR AZZ510-511-514 ABOVE 7000 FEET.

&&

$$

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FRANCIS









000
FXUS65 KTWC 282255
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
355 PM MST WED JAN 28 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST SIGNIFICANT SNOWFALL
WILL BE ABOVE 8000 FEET OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH
COOLER DAYTIME TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL
RETURN EARLY NEXT WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...UPPER LEVEL TROUGH CONTINUES TO DEEPEN WEST OF THE SRN
CALIFORNIA/BAJA CALIFORNIA COASTS VICINITY 125W THIS AFTERNOON. IR
SATELLITE IMAGERY DEPICTED AN EXPANSIVE AREA OF COLDER CLOUD TOPS
EXTENDING FROM FAR SWRN AZ SWWD TO NEAR 20N/120W. EXPECT THICKENING
MOSTLY MID AND HIGH-LEVEL CLOUDS TONIGHT INTO THUR MORNING AHEAD OF
THE DEEPENING UPPER TROUGH. THERE IS A SLIGHT CHANCE OF SHOWERS THUR
AFTERNOON EAST AND SOUTH OF TUCSON WITH DRY CONDITIONS ELSEWHERE.

28/12Z NAM/GFS/ECMWF/CMC REMAIN CONSISTENT WITH DEPICTING WIDESPREAD
SHOWERS TO DEVELOP THUR EVENING...THEN WIDESPREAD SHOWERS SHOULD
OCCUR THUR NIGHT INTO SAT. THE MAIN ADJUSTMENT FOR THIS FORECAST
PACKAGE WAS TO INCREASE POPS VERSUS THE PREVIOUS OFFICIAL FORECAST.
OTHERWISE...QPF/S AND SNOW ACCUMULATIONS WERE LEFT ESSENTIALLY
UNCHANGED. A SLIGHT CHANCE OF THUNDERSTORMS WAS ADDED TO MUCH OF THE
AREA FRI MORNING...AND A SLIGHT CHANCE OF THUNDERSTORMS IS NOW IN
THE OFFICIAL FORECAST SAT AFTERNOON EXCEPT ACROSS THE WHITE
MOUNTAINS.

A 563 DM LOW IS PROGGED TO BE CENTERED MIDDAY FRI JUST SOUTH OF SAN
DIEGO CALIF...THEN THIS UPPER LOW IS PROGGED TO ESSENTIALLY REMAIN
QUASI-STATIONARY OVER SRN CALIFORNIA/NRN BAJA CALIFORNIA THRU MIDDAY
SAT. 28/12Z GFS TOTAL PRECIP WATER VALUE FOR THIS PERIOD IS PROGGED
TO BE ABOUT 1.20 INCHES. THIS PWAT VALUE IS NOW GREATER THAN 4
STANDARD DEVIATIONS ABOVE NORMAL. THE COMBINATION OF ABUNDANT
MOISTURE AND SYNOPTIC SCALE FORCING SHOULD PRODUCE WIDESPREAD
SIGNIFICANT RAINFALL BY MIDDAY SAT. THE UPPER LOW IS THEN PROGGED TO
FILL AND MOVE SEWD INTO SONORA MEXICO SAT NIGHT...THEN CONTINUE WELL
SOUTH OF THE AREA BY SUN EVENING. THERE APPEARS TO BE ENOUGH
RESIDUAL MOISTURE TO JUSTIFY A SLIGHT CHANCE OF SHOWERS EAST-TO-
SOUTH OF TUCSON SUN.

STORM TOTAL LIQUID AMOUNTS ARE NOW FORECAST TO GENERALLY RANGE FROM
0.50 TO 1.50 INCHES IN THE VALLEYS...WITH LOCALLY HEAVIER AMOUNTS
POSSIBLE. LIQUID AMOUNTS IN EXCESS OF 2 INCHES SHOULD OCCUR ACROSS
THE MOUNTAINS...ESPECIALLY NE OF TUCSON TO THE WHITE MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-WED. HIGH TEMPS THUR WILL
AVERAGE ABOUT 5-10 DEGS F OR SO ABOVE NORMAL. EXPECT NEARLY 10-15
DEGS F OF COOLING FRI FOLLOWED BY AN ADDITIONAL 3-5 DEGS F OF
COOLING SAT. A WARMING TREND WILL OCCUR SUN-MON...THEN NO
SIGNIFICANT CHANGE IN DAYTIME TEMPS WILL HAPPEN TUE-WED.

&&

.AVIATION...VALID THRU 30/00Z.
EXPECT INCREASING CLOUDS MAINLY ABOVE 12K FT AGL TONIGHT FOLLOWED BY
A FEW TO SCATTERED CLOUDS AROUND 6-10K FT AGL AND OVERCAST CLOUD
DECKS ABOVE 12K FT AGL BY THURSDAY EVENING. A FEW -SHRA MAY DEVELOP
EAST AND SOUTH OF KTUS THURSDAY AFTERNOON. SURFACE WIND WILL BE LESS
THAN 10 KTS INTO THURSDAY MORNING...THEN SURFACE WIND THURSDAY
AFTERNOON WILL BE SELY/SLY AT 10-15 KTS THURSDAY AFTERNOON. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST
SIGNIFICANT SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE
WHITE MOUNTAINS...MOUNT GRAHAM AND THE CATALINA AND RINCON
MOUNTAINS. A FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH
OF TUCSON SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH
WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH SATURDAY
    MORNING FOR AZZ510-511-514 ABOVE 7000 FEET.

&&

$$

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FRANCIS






000
FXUS65 KTWC 282255
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
355 PM MST WED JAN 28 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING VALLEY RAIN AND MOUNTAIN SNOW
MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST SIGNIFICANT SNOWFALL
WILL BE ABOVE 8000 FEET OR ACROSS THE HIGHEST PEAKS. EXPECT MUCH
COOLER DAYTIME TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL
RETURN EARLY NEXT WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...UPPER LEVEL TROUGH CONTINUES TO DEEPEN WEST OF THE SRN
CALIFORNIA/BAJA CALIFORNIA COASTS VICINITY 125W THIS AFTERNOON. IR
SATELLITE IMAGERY DEPICTED AN EXPANSIVE AREA OF COLDER CLOUD TOPS
EXTENDING FROM FAR SWRN AZ SWWD TO NEAR 20N/120W. EXPECT THICKENING
MOSTLY MID AND HIGH-LEVEL CLOUDS TONIGHT INTO THUR MORNING AHEAD OF
THE DEEPENING UPPER TROUGH. THERE IS A SLIGHT CHANCE OF SHOWERS THUR
AFTERNOON EAST AND SOUTH OF TUCSON WITH DRY CONDITIONS ELSEWHERE.

28/12Z NAM/GFS/ECMWF/CMC REMAIN CONSISTENT WITH DEPICTING WIDESPREAD
SHOWERS TO DEVELOP THUR EVENING...THEN WIDESPREAD SHOWERS SHOULD
OCCUR THUR NIGHT INTO SAT. THE MAIN ADJUSTMENT FOR THIS FORECAST
PACKAGE WAS TO INCREASE POPS VERSUS THE PREVIOUS OFFICIAL FORECAST.
OTHERWISE...QPF/S AND SNOW ACCUMULATIONS WERE LEFT ESSENTIALLY
UNCHANGED. A SLIGHT CHANCE OF THUNDERSTORMS WAS ADDED TO MUCH OF THE
AREA FRI MORNING...AND A SLIGHT CHANCE OF THUNDERSTORMS IS NOW IN
THE OFFICIAL FORECAST SAT AFTERNOON EXCEPT ACROSS THE WHITE
MOUNTAINS.

A 563 DM LOW IS PROGGED TO BE CENTERED MIDDAY FRI JUST SOUTH OF SAN
DIEGO CALIF...THEN THIS UPPER LOW IS PROGGED TO ESSENTIALLY REMAIN
QUASI-STATIONARY OVER SRN CALIFORNIA/NRN BAJA CALIFORNIA THRU MIDDAY
SAT. 28/12Z GFS TOTAL PRECIP WATER VALUE FOR THIS PERIOD IS PROGGED
TO BE ABOUT 1.20 INCHES. THIS PWAT VALUE IS NOW GREATER THAN 4
STANDARD DEVIATIONS ABOVE NORMAL. THE COMBINATION OF ABUNDANT
MOISTURE AND SYNOPTIC SCALE FORCING SHOULD PRODUCE WIDESPREAD
SIGNIFICANT RAINFALL BY MIDDAY SAT. THE UPPER LOW IS THEN PROGGED TO
FILL AND MOVE SEWD INTO SONORA MEXICO SAT NIGHT...THEN CONTINUE WELL
SOUTH OF THE AREA BY SUN EVENING. THERE APPEARS TO BE ENOUGH
RESIDUAL MOISTURE TO JUSTIFY A SLIGHT CHANCE OF SHOWERS EAST-TO-
SOUTH OF TUCSON SUN.

STORM TOTAL LIQUID AMOUNTS ARE NOW FORECAST TO GENERALLY RANGE FROM
0.50 TO 1.50 INCHES IN THE VALLEYS...WITH LOCALLY HEAVIER AMOUNTS
POSSIBLE. LIQUID AMOUNTS IN EXCESS OF 2 INCHES SHOULD OCCUR ACROSS
THE MOUNTAINS...ESPECIALLY NE OF TUCSON TO THE WHITE MOUNTAINS.

SNOW LEVELS FRI MORNING WILL BE AROUND 9000 FEET. SNOW LEVELS WILL
THEN LOWER TO AROUND 8000 FEET FRIDAY EVENING...AND CONTINUE TO
LOWER TO NEAR 7500 FEET BY MIDDAY SATURDAY. STORM TOTAL SNOW
ACCUMULATIONS SHOULD APPROACH OR EXCEED 2 FEET IN THE WHITE
MOUNTAINS ABOVE 7000 FEET...WITH 18-22 INCHES OF SNOWFALL ABOVE 7000
FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING MOUNT
GRAHAM. STORM TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN
12-16 INCHES ACROSS THE CATALINA/RINCON MOUNTAINS ABOVE 7000 FEET.

DRY CONDITIONS WILL THEN PREVAIL SUN NIGHT-WED. HIGH TEMPS THUR WILL
AVERAGE ABOUT 5-10 DEGS F OR SO ABOVE NORMAL. EXPECT NEARLY 10-15
DEGS F OF COOLING FRI FOLLOWED BY AN ADDITIONAL 3-5 DEGS F OF
COOLING SAT. A WARMING TREND WILL OCCUR SUN-MON...THEN NO
SIGNIFICANT CHANGE IN DAYTIME TEMPS WILL HAPPEN TUE-WED.

&&

.AVIATION...VALID THRU 30/00Z.
EXPECT INCREASING CLOUDS MAINLY ABOVE 12K FT AGL TONIGHT FOLLOWED BY
A FEW TO SCATTERED CLOUDS AROUND 6-10K FT AGL AND OVERCAST CLOUD
DECKS ABOVE 12K FT AGL BY THURSDAY EVENING. A FEW -SHRA MAY DEVELOP
EAST AND SOUTH OF KTUS THURSDAY AFTERNOON. SURFACE WIND WILL BE LESS
THAN 10 KTS INTO THURSDAY MORNING...THEN SURFACE WIND THURSDAY
AFTERNOON WILL BE SELY/SLY AT 10-15 KTS THURSDAY AFTERNOON. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A STORM SYSTEM WILL BRING WIDESPREAD VALLEY RAIN AND
MOUNTAIN SNOW MAINLY THURSDAY NIGHT INTO SATURDAY. THE MOST
SIGNIFICANT SNOWFALL WILL OCCUR ACROSS THE HIGHEST PEAKS OF THE
WHITE MOUNTAINS...MOUNT GRAHAM AND THE CATALINA AND RINCON
MOUNTAINS. A FEW LINGERING SHOWERS WILL OCCUR MAINLY EAST TO SOUTH
OF TUCSON SUNDAY...THEN DRY CONDITIONS WILL PREVAIL MONDAY THROUGH
WEDNESDAY.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
    WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH SATURDAY
    MORNING FOR AZZ510-511-514 ABOVE 7000 FEET.

&&

$$

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FRANCIS







000
FXUS65 KTWC 281706
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1005 AM MST WED JAN 28 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN
SNOW WILL THEN OCCUR BEGINNING THURSDAY EVENING AND CONTINUING
THROUGH SATURDAY AS A STORM SYSTEM MOVES ACROSS THE AREA. EXPECT
MUCH COOLER DAYTIME TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS
WILL RETURN EARLY NEXT WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE MOSTLY SUNNY SKIES ACROSS MUCH OF SE AZ AT THIS TIME.
SOMEWHAT THICKER CIRRIFORM CLOUDS WERE ENCROACHING UPON THE
INTERNATIONAL BORDER SOUTH-TO-SOUTHWEST OF TUCSON. DEWPOINTS AT
LOWER ELEVATIONS VALID 16Z RANGED FROM THE MID 30S-40S...AND THESE
TEMPS WERE GENERALLY UNCHANGED VERSUS 24 HOURS AGO. SURFACE TEMPS
VALID 16Z WERE ABOUT 2-5 DEGS F COOLER VERSUS THIS TIME TUE. 28/12Z
KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS 0.64 INCH...WHICH WAS
DOWN ABOUT 0.10 INCH VERSUS 24 HOURS AGO. THE SOUNDING DEPICTED A
VERY DRY LAYER ABOVE 700 MB. 28/12Z UPPER AIR PLOTS DEPICTED RIDGE
AXIS EXTENDING FROM SONORA MEXICO NWWD INTO NRN CALIFORNIA...AND A
TROUGH FURTHER WEST WELL OFF THE SRN CALIFORNIA/BAJA CALIFORNIA
COASTS. LIGHT TO MODERATE WLY/SWLY FLOW PREVAILED OVER SE AZ.

28/12Z NAM/GFS AGREE THAT MOISTURE MOSTLY ABOVE 500 MB WILL INCREASE
TODAY AS THE UPPER RIDGE AXIS MOVES EAST OF THE AREA...AND THE UPPER
TROUGH CONTINUES TO DEEPEN GENERALLY ALONG 125W. THUS...EXPECT
PARTLY CLOUDY SKIES FOR MUCH OF SE AZ THIS AFTERNOON...THEN MOSTLY
CLOUDY TO PERHAPS CLOUDY SKIES TONIGHT INTO THURSDAY MORNING. LIGHT
WINDS WILL CONTINUE TODAY...AND HIGH TEMPS THIS AFTERNOON WILL
AVERAGE ABOUT 5-10 DEGS F ABOVE NORMAL.

THE LOW PRESSURE SYSTEM WILL DEEPEN SW OF THE AREA THUR. 28/12Z GFS
CONTINUES TO POINT TOWARD A SIGNIFICANT PRECIP EVENT FOR SE AZ...
ESPECIALLY THUR NIGHT INTO SAT. THERE ARE NO UPDATES PLANNED AT THIS
TIME. PLEASE REFER THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 29/18Z.
HIGH CLOUDS WILL BE ON THE INCREASE THROUGH THE PERIOD AND SHOULD
SLOWLY LOWER AS THE UPPER LEVEL TROUGH OFF THE BAJA COAST NEARS THE
FORECAST AREA. THERE IS SOME LOW/MID LEVEL RESIDUAL MOISTURE IN
PLACE THAT COULD PRODUCE SOME CU DURING THE AFTERNOON HOURS.
OTHERWISE...LIGHT WINDS EXPECTED THROUGH THE PERIOD. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...BENIGN DAY AHEAD AS THE AREA REMAINS BETWEEN TWO
SYSTEMS. TOMORROW HIGH PRESSURE WILL BEGIN TO SETTLE INTO THE SOUTH
PLAINS OF TEXAS. THIS WILL TIGHTEN THE PRESSURE GRADIENT OUT EAST
WHICH WILL ELEVATE WINDS SOME EAST OF TUCSON...ESPECIALLY ACROSS THE
SAN SIMON VALLEY AND GILA RIVER VALLEY. THEN TOMORROW EVENING THE
SYSTEM CURRENTLY OFF THE BAJA COAST WILL PUSH MOISTURE INTO THE AREA
RESULTING IN A BEGINNING OF SHOWER ACTIVITY FOR THE AREA. THIS
SYSTEM WILL USHER IN DEEP MOISTURE FRIDAY MORNING INTO SATURDAY SO
EXPECT WETTING RAINS ACROSS MOST LOCATIONS...WITH SNOW ACROSS THE
HIGHER ELEVATIONS. THE SHOWER ACTIVITY WILL DIMINISH DURING THE
OVERNIGHT SATURDAY. MAX TEMPERATURES WILL DECREASE COMPARED TO LAST
SEVERAL DAYS ON FRIDAY AND GOING INTO THE WEEKEND. HOWEVER...MIN
TEMPERATURES WILL LIKELY REMAIN ABOUT THE SAME UNTIL SUNDAY ONCE
THINGS CLEAR OUT.

&&

.PREV DISCUSSION...WATER VAPOR IMAGERY AND 28/00Z UPPER-AIR PLOTS
SHOW RIDGING MOVING BY TO OUR EAST AS A PACIFIC STORM SYSTEM
APPROACHES THE WEST COAST. WE WILL BE DRY THROUGH MUCH OF THURSDAY
WITH SOME HIGH CLOUDINESS MOVING BY FROM TIME TO TIME. THE MAIN
STORY WITH THIS FORECAST PACKAGE WITH BE THE MAJOR STORM SYSTEM THAT
WILL PRODUCE CONSIDERABLE PRECIPITATION AMOUNTS AS IT MOVES ACROSS
THE DESERT SOUTHWEST.

MODELS INDICATE THAT THIS SYSTEM WILL BE MOVING INTO THE WEST COAST
LATE THURSDAY WITH ABUNDANT MOISTURE OUT AHEAD OF THE TROUGH AXIS
MAKING ITS WAY INTO ARIZONA DURING THE DAY ON THURSDAY. ISOLATED
SHOWERS WILL BEGIN TO DEVELOP THURSDAY AFTERNOON...MAINLY OVER THE
HIGHER TERRAIN EAST OF TUCSON. BY THURSDAY EVENING THE LOW WILL
BEGIN TO DEVELOP INTO A CLOSED LOW OVER THE GREAT BASIN...WITH THE
ASSOCIATED TROUGH AXIS EXTENDING SOUTH THROUGH SOUTHERN CALIFORNIA
AND JUST WEST OF THE BAJA PENINSULA. DEEP MOISTURE WILL ALREADY BE
OVER MUCH OF THE DESERT SOUTHWEST BY THAT TIME...INCLUDING MUCH OF
ARIZONA...PARTS OF NEW MEXICO...AS WELL AS PARTS OF UTAH AND NEVADA.
PW`S ARE PROGGED TO INCREASE TO MORE THAN AN INCH EARLY FRIDAY AND
EVEN AROUND 1.25 INCHES ACROSS THE FAR WESTERN DESERTS OF SOUTHWEST
ARIZONA.

QPF AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO BE LARGE WITH WPC`S DAY
3 FORECAST VALID FROM 12Z FRI THRU 12Z SAT SHOWING A LARGE SWATH OF
AMOUNTS IN EXCESS OF 0.75 INCHES COVERING MOST OF MY FORECAST
AREA...WITH HIGHER AMOUNTS OVER THE MOUNTAIN RANGES. LESSER AMOUNTS
OUT WEST NEAR AJO...BUT STILL BETWEEN 0.25 AND 0.50 INCHES IN THIS
24 HOUR PERIOD. OF COURSE QPF AMOUNTS WILL END UP BEING EVEN LARGER
THAN THIS GIVEN THAT THIS STORM WILL IMPACT SOUTHEAST ARIZONA FOR
ABOUT 48 HOURS (EARLY THURSDAY EVENING THROUGH LATE SATURDAY
AFTERNOON).

AMOUNTS FOR DESERT AND VALLEY LOCATIONS COULD RANGE FROM AROUND 1.25
TO 1.50 INCHES BY THE TIME ALL IS SAID AND DONE. AS A RESULT...SNOW
AMOUNTS WILL ALSO BE CONSIDERABLE. AT THIS TIME THE BEST THREAT FOR
HEAVY SNOW WILL OCCUR OVER THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY OVER EAST CENTRAL ARIZONA. NEXT IN LINE WILL BE THE PINALENO
MOUNTAINS (MT. GRAHAM) OF SOUTH CENTRAL GRAHAM COUNTY AND THE SANTA
CATALINA MOUNTAINS (MT. LEMMON) AND RINCON MOUNTAINS.

SNOWFALL AMOUNTS DURING THE ENTIRE 48 HOUR STORM TOTAL PERIOD WILL
LIKELY EXCEED 24 INCHES FOR THE WHITE MOUNTAINS...20 TO 24 INCHES
FOR MT. GRAHAM IN THE PINALENO MOUNTAINS AND 12 TO 18 INCHES FOR MT.
LEMMON IN THE SANTA CATALINA MOUNTAINS. THERE IS STILL SOME
UNCERTAINTY REGARDING STORM TOTALS FOR THE CHIRICAHUA MOUNTAINS AS
WELL AS THE REMAINING MOUNTAIN RANGES ACROSS SOUTHEAST ARIZONA NEAR
THE BORDER WITH MEXICO. FOR NOW WILL ISSUE A WINTER STORM WATCH FROM
EARLY FRIDAY MORNING THROUGH MIDDAY SATURDAY FOR THE ELEVATIONS
ABOVE 7000 FEET FOR GRAHAM AND GREENLEE COUNTIES AND THE SANTA
CATALINA MOUNTAINS AND RINCON MOUNTAINS OF EASTERN PIMA COUNTY. AS
MODELS SHED MORE LIGHT ON THIS APPROACHING SYSTEM THIS WATCH MAY BE
EXTENDED TO COVER MORE TERRITORY AND/OR BE UPGRADED IN THE NEXT DAY
OR SO.

THIS SYSTEM WILL FINALLY EXIT THE REGION LATE SATURDAY/EARLY SUNDAY
WITH RIDGING BUILDING IN BEHIND THE SYSTEM FOR WARMING TEMPERATURES
AND A RETURN TO DRY WEATHER. BEGINNING MONDAY...WEAK DISTURBANCES
WILL BRUSH BY TO OUR NORTH...RESULTING IN INTERMITTENT CLOUDINESS...
BUT WE SHOULD REMAIN DRY THROUGH NEXT TUESDAY.

FOR TUCSON...HIGH TEMPERATURES GENERALLY AROUND 10 DEGS ABOVE NORMAL
TODAY AND THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FOR FRIDAY AND
SATURDAY. THEREAFTER...HIGHS WILL HOVER A COUPLE OF DEGREES EITHER
SIDE OF NORMAL. LOWS WILL RANGE FROM 10 TO 12 DEGS ABOVE NORMAL
THURSDAY AND FRIDAY MORNINGS...THEN 6 TO 8 DEGS ABOVE NORMAL FOR
SATURDAY. THEREAFTER...LOWS 1 TO 3 DEGS ABOVE NORMAL.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM LATE
      THURSDAY NIGHT THROUGH SATURDAY MORNING FOR AZZ510-511-514
      ABOVE 7000 FEET.

&&

$$

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







000
FXUS65 KTWC 281706
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1005 AM MST WED JAN 28 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN
SNOW WILL THEN OCCUR BEGINNING THURSDAY EVENING AND CONTINUING
THROUGH SATURDAY AS A STORM SYSTEM MOVES ACROSS THE AREA. EXPECT
MUCH COOLER DAYTIME TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS
WILL RETURN EARLY NEXT WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE MOSTLY SUNNY SKIES ACROSS MUCH OF SE AZ AT THIS TIME.
SOMEWHAT THICKER CIRRIFORM CLOUDS WERE ENCROACHING UPON THE
INTERNATIONAL BORDER SOUTH-TO-SOUTHWEST OF TUCSON. DEWPOINTS AT
LOWER ELEVATIONS VALID 16Z RANGED FROM THE MID 30S-40S...AND THESE
TEMPS WERE GENERALLY UNCHANGED VERSUS 24 HOURS AGO. SURFACE TEMPS
VALID 16Z WERE ABOUT 2-5 DEGS F COOLER VERSUS THIS TIME TUE. 28/12Z
KTWC SOUNDING TOTAL PRECIP WATER VALUE WAS 0.64 INCH...WHICH WAS
DOWN ABOUT 0.10 INCH VERSUS 24 HOURS AGO. THE SOUNDING DEPICTED A
VERY DRY LAYER ABOVE 700 MB. 28/12Z UPPER AIR PLOTS DEPICTED RIDGE
AXIS EXTENDING FROM SONORA MEXICO NWWD INTO NRN CALIFORNIA...AND A
TROUGH FURTHER WEST WELL OFF THE SRN CALIFORNIA/BAJA CALIFORNIA
COASTS. LIGHT TO MODERATE WLY/SWLY FLOW PREVAILED OVER SE AZ.

28/12Z NAM/GFS AGREE THAT MOISTURE MOSTLY ABOVE 500 MB WILL INCREASE
TODAY AS THE UPPER RIDGE AXIS MOVES EAST OF THE AREA...AND THE UPPER
TROUGH CONTINUES TO DEEPEN GENERALLY ALONG 125W. THUS...EXPECT
PARTLY CLOUDY SKIES FOR MUCH OF SE AZ THIS AFTERNOON...THEN MOSTLY
CLOUDY TO PERHAPS CLOUDY SKIES TONIGHT INTO THURSDAY MORNING. LIGHT
WINDS WILL CONTINUE TODAY...AND HIGH TEMPS THIS AFTERNOON WILL
AVERAGE ABOUT 5-10 DEGS F ABOVE NORMAL.

THE LOW PRESSURE SYSTEM WILL DEEPEN SW OF THE AREA THUR. 28/12Z GFS
CONTINUES TO POINT TOWARD A SIGNIFICANT PRECIP EVENT FOR SE AZ...
ESPECIALLY THUR NIGHT INTO SAT. THERE ARE NO UPDATES PLANNED AT THIS
TIME. PLEASE REFER THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 29/18Z.
HIGH CLOUDS WILL BE ON THE INCREASE THROUGH THE PERIOD AND SHOULD
SLOWLY LOWER AS THE UPPER LEVEL TROUGH OFF THE BAJA COAST NEARS THE
FORECAST AREA. THERE IS SOME LOW/MID LEVEL RESIDUAL MOISTURE IN
PLACE THAT COULD PRODUCE SOME CU DURING THE AFTERNOON HOURS.
OTHERWISE...LIGHT WINDS EXPECTED THROUGH THE PERIOD. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...BENIGN DAY AHEAD AS THE AREA REMAINS BETWEEN TWO
SYSTEMS. TOMORROW HIGH PRESSURE WILL BEGIN TO SETTLE INTO THE SOUTH
PLAINS OF TEXAS. THIS WILL TIGHTEN THE PRESSURE GRADIENT OUT EAST
WHICH WILL ELEVATE WINDS SOME EAST OF TUCSON...ESPECIALLY ACROSS THE
SAN SIMON VALLEY AND GILA RIVER VALLEY. THEN TOMORROW EVENING THE
SYSTEM CURRENTLY OFF THE BAJA COAST WILL PUSH MOISTURE INTO THE AREA
RESULTING IN A BEGINNING OF SHOWER ACTIVITY FOR THE AREA. THIS
SYSTEM WILL USHER IN DEEP MOISTURE FRIDAY MORNING INTO SATURDAY SO
EXPECT WETTING RAINS ACROSS MOST LOCATIONS...WITH SNOW ACROSS THE
HIGHER ELEVATIONS. THE SHOWER ACTIVITY WILL DIMINISH DURING THE
OVERNIGHT SATURDAY. MAX TEMPERATURES WILL DECREASE COMPARED TO LAST
SEVERAL DAYS ON FRIDAY AND GOING INTO THE WEEKEND. HOWEVER...MIN
TEMPERATURES WILL LIKELY REMAIN ABOUT THE SAME UNTIL SUNDAY ONCE
THINGS CLEAR OUT.

&&

.PREV DISCUSSION...WATER VAPOR IMAGERY AND 28/00Z UPPER-AIR PLOTS
SHOW RIDGING MOVING BY TO OUR EAST AS A PACIFIC STORM SYSTEM
APPROACHES THE WEST COAST. WE WILL BE DRY THROUGH MUCH OF THURSDAY
WITH SOME HIGH CLOUDINESS MOVING BY FROM TIME TO TIME. THE MAIN
STORY WITH THIS FORECAST PACKAGE WITH BE THE MAJOR STORM SYSTEM THAT
WILL PRODUCE CONSIDERABLE PRECIPITATION AMOUNTS AS IT MOVES ACROSS
THE DESERT SOUTHWEST.

MODELS INDICATE THAT THIS SYSTEM WILL BE MOVING INTO THE WEST COAST
LATE THURSDAY WITH ABUNDANT MOISTURE OUT AHEAD OF THE TROUGH AXIS
MAKING ITS WAY INTO ARIZONA DURING THE DAY ON THURSDAY. ISOLATED
SHOWERS WILL BEGIN TO DEVELOP THURSDAY AFTERNOON...MAINLY OVER THE
HIGHER TERRAIN EAST OF TUCSON. BY THURSDAY EVENING THE LOW WILL
BEGIN TO DEVELOP INTO A CLOSED LOW OVER THE GREAT BASIN...WITH THE
ASSOCIATED TROUGH AXIS EXTENDING SOUTH THROUGH SOUTHERN CALIFORNIA
AND JUST WEST OF THE BAJA PENINSULA. DEEP MOISTURE WILL ALREADY BE
OVER MUCH OF THE DESERT SOUTHWEST BY THAT TIME...INCLUDING MUCH OF
ARIZONA...PARTS OF NEW MEXICO...AS WELL AS PARTS OF UTAH AND NEVADA.
PW`S ARE PROGGED TO INCREASE TO MORE THAN AN INCH EARLY FRIDAY AND
EVEN AROUND 1.25 INCHES ACROSS THE FAR WESTERN DESERTS OF SOUTHWEST
ARIZONA.

QPF AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO BE LARGE WITH WPC`S DAY
3 FORECAST VALID FROM 12Z FRI THRU 12Z SAT SHOWING A LARGE SWATH OF
AMOUNTS IN EXCESS OF 0.75 INCHES COVERING MOST OF MY FORECAST
AREA...WITH HIGHER AMOUNTS OVER THE MOUNTAIN RANGES. LESSER AMOUNTS
OUT WEST NEAR AJO...BUT STILL BETWEEN 0.25 AND 0.50 INCHES IN THIS
24 HOUR PERIOD. OF COURSE QPF AMOUNTS WILL END UP BEING EVEN LARGER
THAN THIS GIVEN THAT THIS STORM WILL IMPACT SOUTHEAST ARIZONA FOR
ABOUT 48 HOURS (EARLY THURSDAY EVENING THROUGH LATE SATURDAY
AFTERNOON).

AMOUNTS FOR DESERT AND VALLEY LOCATIONS COULD RANGE FROM AROUND 1.25
TO 1.50 INCHES BY THE TIME ALL IS SAID AND DONE. AS A RESULT...SNOW
AMOUNTS WILL ALSO BE CONSIDERABLE. AT THIS TIME THE BEST THREAT FOR
HEAVY SNOW WILL OCCUR OVER THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY OVER EAST CENTRAL ARIZONA. NEXT IN LINE WILL BE THE PINALENO
MOUNTAINS (MT. GRAHAM) OF SOUTH CENTRAL GRAHAM COUNTY AND THE SANTA
CATALINA MOUNTAINS (MT. LEMMON) AND RINCON MOUNTAINS.

SNOWFALL AMOUNTS DURING THE ENTIRE 48 HOUR STORM TOTAL PERIOD WILL
LIKELY EXCEED 24 INCHES FOR THE WHITE MOUNTAINS...20 TO 24 INCHES
FOR MT. GRAHAM IN THE PINALENO MOUNTAINS AND 12 TO 18 INCHES FOR MT.
LEMMON IN THE SANTA CATALINA MOUNTAINS. THERE IS STILL SOME
UNCERTAINTY REGARDING STORM TOTALS FOR THE CHIRICAHUA MOUNTAINS AS
WELL AS THE REMAINING MOUNTAIN RANGES ACROSS SOUTHEAST ARIZONA NEAR
THE BORDER WITH MEXICO. FOR NOW WILL ISSUE A WINTER STORM WATCH FROM
EARLY FRIDAY MORNING THROUGH MIDDAY SATURDAY FOR THE ELEVATIONS
ABOVE 7000 FEET FOR GRAHAM AND GREENLEE COUNTIES AND THE SANTA
CATALINA MOUNTAINS AND RINCON MOUNTAINS OF EASTERN PIMA COUNTY. AS
MODELS SHED MORE LIGHT ON THIS APPROACHING SYSTEM THIS WATCH MAY BE
EXTENDED TO COVER MORE TERRITORY AND/OR BE UPGRADED IN THE NEXT DAY
OR SO.

THIS SYSTEM WILL FINALLY EXIT THE REGION LATE SATURDAY/EARLY SUNDAY
WITH RIDGING BUILDING IN BEHIND THE SYSTEM FOR WARMING TEMPERATURES
AND A RETURN TO DRY WEATHER. BEGINNING MONDAY...WEAK DISTURBANCES
WILL BRUSH BY TO OUR NORTH...RESULTING IN INTERMITTENT CLOUDINESS...
BUT WE SHOULD REMAIN DRY THROUGH NEXT TUESDAY.

FOR TUCSON...HIGH TEMPERATURES GENERALLY AROUND 10 DEGS ABOVE NORMAL
TODAY AND THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FOR FRIDAY AND
SATURDAY. THEREAFTER...HIGHS WILL HOVER A COUPLE OF DEGREES EITHER
SIDE OF NORMAL. LOWS WILL RANGE FROM 10 TO 12 DEGS ABOVE NORMAL
THURSDAY AND FRIDAY MORNINGS...THEN 6 TO 8 DEGS ABOVE NORMAL FOR
SATURDAY. THEREAFTER...LOWS 1 TO 3 DEGS ABOVE NORMAL.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM LATE
      THURSDAY NIGHT THROUGH SATURDAY MORNING FOR AZZ510-511-514
      ABOVE 7000 FEET.

&&

$$

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






000
FXUS65 KTWC 281003
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
303 AM MST WED JAN 28 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN SNOW WILL
THEN OCCUR BEGINNING THURSDAY NIGHT AND CONTINUING THROUGH SATURDAY
AS A STORM SYSTEM MOVES ACROSS THE AREA. EXPECT MUCH COOLER DAYTIME
TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL RETURN EARLY NEXT
WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 28/00Z UPPER-AIR PLOTS SHOW
RIDGING MOVING BY TO OUR EAST AS A PACIFIC STORM SYSTEM APPROACHES
THE WEST COAST. WE WILL BE DRY THROUGH MUCH OF THURSDAY WITH SOME
HIGH CLOUDINESS MOVING BY FROM TIME TO TIME. THE MAIN STORY WITH
THIS FORECAST PACKAGE WITH BE THE MAJOR STORM SYSTEM THAT WILL
PRODUCE CONSIDERABLE PRECIPITATION AMOUNTS AS IT MOVES ACROSS THE
DESERT SOUTHWEST.

MODELS INDICATE THAT THIS SYSTEM WILL BE MOVING INTO THE WEST COAST
LATE THURSDAY WITH ABUNDANT MOISTURE OUT AHEAD OF THE TROUGH AXIS
MAKING ITS WAY INTO ARIZONA DURING THE DAY ON THURSDAY. ISOLATED
SHOWERS WILL BEGIN TO DEVELOP THURSDAY AFTERNOON...MAINLY OVER THE
HIGHER TERRAIN EAST OF TUCSON. BY THURSDAY EVENING THE LOW WILL
BEGIN TO DEVELOP INTO A CLOSED LOW OVER THE GREAT BASIN...WITH THE
ASSOCIATED TROUGH AXIS EXTENDING SOUTH THROUGH SOUTHERN CALIFORNIA
AND JUST WEST OF THE BAJA PENINSULA. DEEP MOISTURE WILL ALREADY BE
OVER MUCH OF THE DESERT SOUTHWEST BY THAT TIME...INCLUDING MUCH OF
ARIZONA...PARTS OF NEW MEXICO...AS WELL AS PARTS OF UTAH AND NEVADA.
PW`S ARE PROGGED TO INCREASE TO MORE THAN AN INCH EARLY FRIDAY AND
EVEN AROUND 1.25 INCHES ACROSS THE FAR WESTERN DESERTS OF SOUTHWEST
ARIZONA.

QPF AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO BE LARGE WITH WPC`S DAY
3 FORECAST VALID FROM 12Z FRI THRU 12Z SAT SHOWING A LARGE SWATH OF
AMOUNTS IN EXCESS OF 0.75 INCHES COVERING MOST OF MY FORECAST
AREA...WITH HIGHER AMOUNTS OVER THE MOUNTAIN RANGES. LESSER AMOUNTS
OUT WEST NEAR AJO...BUT STILL BETWEEN 0.25 AND 0.50 INCHES IN THIS
24 HOUR PERIOD. OF COURSE QPF AMOUNTS WILL END UP BEING EVEN LARGER
THAN THIS GIVEN THAT THIS STORM WILL IMPACT SOUTHEAST ARIZONA FOR
ABOUT 48 HOURS (EARLY THURSDAY EVENING THROUGH LATE SATURDAY
AFTERNOON).

AMOUNTS FOR DESERT AND VALLEY LOCATIONS COULD RANGE FROM AROUND 1.25
TO 1.50 INCHES BY THE TIME ALL IS SAID AND DONE. AS A RESULT...SNOW
AMOUNTS WILL ALSO BE CONSIDERABLE. AT THIS TIME THE BEST THREAT FOR
HEAVY SNOW WILL OCCUR OVER THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY OVER EAST CENTRAL ARIZONA. NEXT IN LINE WILL BE THE PINALENO
MOUNTAINS (MT. GRAHAM) OF SOUTH CENTRAL GRAHAM COUNTY AND THE SANTA
CATALINA MOUNTAINS (MT. LEMMON) AND RINCON MOUNTAINS.

SNOWFALL AMOUNTS DURING THE ENTIRE 48 HOUR STORM TOTAL PERIOD WILL
LIKELY EXCEED 24 INCHES FOR THE WHITE MOUNTAINS...20 TO 24 INCHES
FOR MT. GRAHAM IN THE PINALENO MOUNTAINS AND 12 TO 18 INCHES FOR MT.
LEMMON IN THE SANTA CATALINA MOUNTAINS. THERE IS STILL SOME
UNCERTAINTY REGARDING STORM TOTALS FOR THE CHIRICAHUA MOUNTAINS AS
WELL AS THE REMAINING MOUNTAIN RANGES ACROSS SOUTHEAST ARIZONA NEAR
THE BORDER WITH MEXICO. FOR NOW WILL ISSUE A WINTER STORM WATCH FROM
EARLY FRIDAY MORNING THROUGH MIDDAY SATURDAY FOR THE ELEVATIONS
ABOVE 7000 FEET FOR GRAHAM AND GREENLEE COUNTIES AND THE SANTA
CATALINA MOUNTAINS AND RINCON MOUNTAINS OF EASTERN PIMA COUNTY. AS
MODELS SHED MORE LIGHT ON THIS APPROACHING SYSTEM THIS WATCH MAY BE
EXTENDED TO COVER MORE TERRITORY AND/OR BE UPGRADED IN THE NEXT DAY
OR SO.

THIS SYSTEM WILL FINALLY EXIT THE REGION LATE SATURDAY/EARLY SUNDAY
WITH RIDGING BUILDING IN BEHIND THE SYSTEM FOR WARMING TEMPERATURES
AND A RETURN TO DRY WEATHER. BEGINNING MONDAY...WEAK DISTURBANCES
WILL BRUSH BY TO OUR NORTH...RESULTING IN INTERMITTENT CLOUDINESS...
BUT WE SHOULD REMAIN DRY THROUGH NEXT TUESDAY.

FOR TUCSON...HIGH TEMPERATURES GENERALLY AROUND 10 DEGS ABOVE NORMAL
TODAY AND THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FOR FRIDAY AND
SATURDAY. THEREAFTER...HIGHS WILL HOVER A COUPLE OF DEGREES EITHER
SIDE OF NORMAL. LOWS WILL RANGE FROM 10 TO 12 DEGS ABOVE NORMAL
THURSDAY AND FRIDAY MORNINGS...THEN 6 TO 8 DEGS ABOVE NORMAL FOR
SATURDAY. THEREAFTER...LOWS 1 TO 3 DEGS ABOVE NORMAL.

&&

.AVIATION...VALID THRU 29/12Z.
HIGH CLOUDS WILL BE ON THE INCREASE THROUGH THE PERIOD AND SHOULD
SLOWLY LOWER AS THE UPPER LEVEL TROUGH OFF THE BAJA COAST NEARS THE
FORECAST AREA. THERE IS SOME LOW/MID RESIDUAL MOISTURE IN PLACE THAT
COULD PRODUCE SOME CU DURING THE AFTERNOON HOURS. OTHERWISE...LIGHT
WINDS EXPECTED THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...BENIGN DAY AHEAD AS THE AREA REMAINS BETWEEN TWO
SYSTEMS. TOMORROW HIGH PRESSURE WILL BEGIN TO SETTLE INTO THE SOUTH
PLAINS OF TEXAS. THIS WILL TIGHTEN THE PRESSURE GRADIENT OUT EAST
WHICH WILL ELEVATE WINDS SOME EAST OF TUCSON...ESPECIALLY ACROSS THE
SAN SIMON VALLEY AND GILA RIVER VALLEY. THEN TOMORROW EVENING THE
SYSTEM CURRENTLY OFF THE BAJA COAST WILL PUSH MOISTURE INTO THE AREA
RESULTING IN A BEGINNING OF SHOWER ACTIVITY FOR THE AREA. THIS
SYSTEM WILL USHER IN DEEP MOISTURE FRIDAY MORNING INTO SATURDAY SO
EXPECT WETTING RAINS ACROSS MOST LOCATIONS...WITH SNOW ACROSS THE
HIGHER ELEVATIONS. THE SHOWER ACTIVITY WILL DIMINISH DURING THE
OVERNIGHT SATURDAY. MAX TEMPERATURES WILL DECREASE COMPARED TO LAST
SEVERAL DAYS ON FRIDAY AND GOING INTO THE WEEKEND. HOWEVER...MIN
TEMPERATURES WILL LIKELY REMAIN ABOUT THE SAME UNTIL SUNDAY ONCE
THINGS CLEAR OUT.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM LATE
      THURSDAY NIGHT THROUGH SATURDAY MORNING FOR AZZ510-511-514
      ABOVE 7000 FEET.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...MEADOWS







000
FXUS65 KTWC 281003
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
303 AM MST WED JAN 28 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN SNOW WILL
THEN OCCUR BEGINNING THURSDAY NIGHT AND CONTINUING THROUGH SATURDAY
AS A STORM SYSTEM MOVES ACROSS THE AREA. EXPECT MUCH COOLER DAYTIME
TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL RETURN EARLY NEXT
WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 28/00Z UPPER-AIR PLOTS SHOW
RIDGING MOVING BY TO OUR EAST AS A PACIFIC STORM SYSTEM APPROACHES
THE WEST COAST. WE WILL BE DRY THROUGH MUCH OF THURSDAY WITH SOME
HIGH CLOUDINESS MOVING BY FROM TIME TO TIME. THE MAIN STORY WITH
THIS FORECAST PACKAGE WITH BE THE MAJOR STORM SYSTEM THAT WILL
PRODUCE CONSIDERABLE PRECIPITATION AMOUNTS AS IT MOVES ACROSS THE
DESERT SOUTHWEST.

MODELS INDICATE THAT THIS SYSTEM WILL BE MOVING INTO THE WEST COAST
LATE THURSDAY WITH ABUNDANT MOISTURE OUT AHEAD OF THE TROUGH AXIS
MAKING ITS WAY INTO ARIZONA DURING THE DAY ON THURSDAY. ISOLATED
SHOWERS WILL BEGIN TO DEVELOP THURSDAY AFTERNOON...MAINLY OVER THE
HIGHER TERRAIN EAST OF TUCSON. BY THURSDAY EVENING THE LOW WILL
BEGIN TO DEVELOP INTO A CLOSED LOW OVER THE GREAT BASIN...WITH THE
ASSOCIATED TROUGH AXIS EXTENDING SOUTH THROUGH SOUTHERN CALIFORNIA
AND JUST WEST OF THE BAJA PENINSULA. DEEP MOISTURE WILL ALREADY BE
OVER MUCH OF THE DESERT SOUTHWEST BY THAT TIME...INCLUDING MUCH OF
ARIZONA...PARTS OF NEW MEXICO...AS WELL AS PARTS OF UTAH AND NEVADA.
PW`S ARE PROGGED TO INCREASE TO MORE THAN AN INCH EARLY FRIDAY AND
EVEN AROUND 1.25 INCHES ACROSS THE FAR WESTERN DESERTS OF SOUTHWEST
ARIZONA.

QPF AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO BE LARGE WITH WPC`S DAY
3 FORECAST VALID FROM 12Z FRI THRU 12Z SAT SHOWING A LARGE SWATH OF
AMOUNTS IN EXCESS OF 0.75 INCHES COVERING MOST OF MY FORECAST
AREA...WITH HIGHER AMOUNTS OVER THE MOUNTAIN RANGES. LESSER AMOUNTS
OUT WEST NEAR AJO...BUT STILL BETWEEN 0.25 AND 0.50 INCHES IN THIS
24 HOUR PERIOD. OF COURSE QPF AMOUNTS WILL END UP BEING EVEN LARGER
THAN THIS GIVEN THAT THIS STORM WILL IMPACT SOUTHEAST ARIZONA FOR
ABOUT 48 HOURS (EARLY THURSDAY EVENING THROUGH LATE SATURDAY
AFTERNOON).

AMOUNTS FOR DESERT AND VALLEY LOCATIONS COULD RANGE FROM AROUND 1.25
TO 1.50 INCHES BY THE TIME ALL IS SAID AND DONE. AS A RESULT...SNOW
AMOUNTS WILL ALSO BE CONSIDERABLE. AT THIS TIME THE BEST THREAT FOR
HEAVY SNOW WILL OCCUR OVER THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY OVER EAST CENTRAL ARIZONA. NEXT IN LINE WILL BE THE PINALENO
MOUNTAINS (MT. GRAHAM) OF SOUTH CENTRAL GRAHAM COUNTY AND THE SANTA
CATALINA MOUNTAINS (MT. LEMMON) AND RINCON MOUNTAINS.

SNOWFALL AMOUNTS DURING THE ENTIRE 48 HOUR STORM TOTAL PERIOD WILL
LIKELY EXCEED 24 INCHES FOR THE WHITE MOUNTAINS...20 TO 24 INCHES
FOR MT. GRAHAM IN THE PINALENO MOUNTAINS AND 12 TO 18 INCHES FOR MT.
LEMMON IN THE SANTA CATALINA MOUNTAINS. THERE IS STILL SOME
UNCERTAINTY REGARDING STORM TOTALS FOR THE CHIRICAHUA MOUNTAINS AS
WELL AS THE REMAINING MOUNTAIN RANGES ACROSS SOUTHEAST ARIZONA NEAR
THE BORDER WITH MEXICO. FOR NOW WILL ISSUE A WINTER STORM WATCH FROM
EARLY FRIDAY MORNING THROUGH MIDDAY SATURDAY FOR THE ELEVATIONS
ABOVE 7000 FEET FOR GRAHAM AND GREENLEE COUNTIES AND THE SANTA
CATALINA MOUNTAINS AND RINCON MOUNTAINS OF EASTERN PIMA COUNTY. AS
MODELS SHED MORE LIGHT ON THIS APPROACHING SYSTEM THIS WATCH MAY BE
EXTENDED TO COVER MORE TERRITORY AND/OR BE UPGRADED IN THE NEXT DAY
OR SO.

THIS SYSTEM WILL FINALLY EXIT THE REGION LATE SATURDAY/EARLY SUNDAY
WITH RIDGING BUILDING IN BEHIND THE SYSTEM FOR WARMING TEMPERATURES
AND A RETURN TO DRY WEATHER. BEGINNING MONDAY...WEAK DISTURBANCES
WILL BRUSH BY TO OUR NORTH...RESULTING IN INTERMITTENT CLOUDINESS...
BUT WE SHOULD REMAIN DRY THROUGH NEXT TUESDAY.

FOR TUCSON...HIGH TEMPERATURES GENERALLY AROUND 10 DEGS ABOVE NORMAL
TODAY AND THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FOR FRIDAY AND
SATURDAY. THEREAFTER...HIGHS WILL HOVER A COUPLE OF DEGREES EITHER
SIDE OF NORMAL. LOWS WILL RANGE FROM 10 TO 12 DEGS ABOVE NORMAL
THURSDAY AND FRIDAY MORNINGS...THEN 6 TO 8 DEGS ABOVE NORMAL FOR
SATURDAY. THEREAFTER...LOWS 1 TO 3 DEGS ABOVE NORMAL.

&&

.AVIATION...VALID THRU 29/12Z.
HIGH CLOUDS WILL BE ON THE INCREASE THROUGH THE PERIOD AND SHOULD
SLOWLY LOWER AS THE UPPER LEVEL TROUGH OFF THE BAJA COAST NEARS THE
FORECAST AREA. THERE IS SOME LOW/MID RESIDUAL MOISTURE IN PLACE THAT
COULD PRODUCE SOME CU DURING THE AFTERNOON HOURS. OTHERWISE...LIGHT
WINDS EXPECTED THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...BENIGN DAY AHEAD AS THE AREA REMAINS BETWEEN TWO
SYSTEMS. TOMORROW HIGH PRESSURE WILL BEGIN TO SETTLE INTO THE SOUTH
PLAINS OF TEXAS. THIS WILL TIGHTEN THE PRESSURE GRADIENT OUT EAST
WHICH WILL ELEVATE WINDS SOME EAST OF TUCSON...ESPECIALLY ACROSS THE
SAN SIMON VALLEY AND GILA RIVER VALLEY. THEN TOMORROW EVENING THE
SYSTEM CURRENTLY OFF THE BAJA COAST WILL PUSH MOISTURE INTO THE AREA
RESULTING IN A BEGINNING OF SHOWER ACTIVITY FOR THE AREA. THIS
SYSTEM WILL USHER IN DEEP MOISTURE FRIDAY MORNING INTO SATURDAY SO
EXPECT WETTING RAINS ACROSS MOST LOCATIONS...WITH SNOW ACROSS THE
HIGHER ELEVATIONS. THE SHOWER ACTIVITY WILL DIMINISH DURING THE
OVERNIGHT SATURDAY. MAX TEMPERATURES WILL DECREASE COMPARED TO LAST
SEVERAL DAYS ON FRIDAY AND GOING INTO THE WEEKEND. HOWEVER...MIN
TEMPERATURES WILL LIKELY REMAIN ABOUT THE SAME UNTIL SUNDAY ONCE
THINGS CLEAR OUT.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM LATE
      THURSDAY NIGHT THROUGH SATURDAY MORNING FOR AZZ510-511-514
      ABOVE 7000 FEET.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...MEADOWS








000
FXUS65 KTWC 281003
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
303 AM MST WED JAN 28 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN SNOW WILL
THEN OCCUR BEGINNING THURSDAY NIGHT AND CONTINUING THROUGH SATURDAY
AS A STORM SYSTEM MOVES ACROSS THE AREA. EXPECT MUCH COOLER DAYTIME
TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL RETURN EARLY NEXT
WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 28/00Z UPPER-AIR PLOTS SHOW
RIDGING MOVING BY TO OUR EAST AS A PACIFIC STORM SYSTEM APPROACHES
THE WEST COAST. WE WILL BE DRY THROUGH MUCH OF THURSDAY WITH SOME
HIGH CLOUDINESS MOVING BY FROM TIME TO TIME. THE MAIN STORY WITH
THIS FORECAST PACKAGE WITH BE THE MAJOR STORM SYSTEM THAT WILL
PRODUCE CONSIDERABLE PRECIPITATION AMOUNTS AS IT MOVES ACROSS THE
DESERT SOUTHWEST.

MODELS INDICATE THAT THIS SYSTEM WILL BE MOVING INTO THE WEST COAST
LATE THURSDAY WITH ABUNDANT MOISTURE OUT AHEAD OF THE TROUGH AXIS
MAKING ITS WAY INTO ARIZONA DURING THE DAY ON THURSDAY. ISOLATED
SHOWERS WILL BEGIN TO DEVELOP THURSDAY AFTERNOON...MAINLY OVER THE
HIGHER TERRAIN EAST OF TUCSON. BY THURSDAY EVENING THE LOW WILL
BEGIN TO DEVELOP INTO A CLOSED LOW OVER THE GREAT BASIN...WITH THE
ASSOCIATED TROUGH AXIS EXTENDING SOUTH THROUGH SOUTHERN CALIFORNIA
AND JUST WEST OF THE BAJA PENINSULA. DEEP MOISTURE WILL ALREADY BE
OVER MUCH OF THE DESERT SOUTHWEST BY THAT TIME...INCLUDING MUCH OF
ARIZONA...PARTS OF NEW MEXICO...AS WELL AS PARTS OF UTAH AND NEVADA.
PW`S ARE PROGGED TO INCREASE TO MORE THAN AN INCH EARLY FRIDAY AND
EVEN AROUND 1.25 INCHES ACROSS THE FAR WESTERN DESERTS OF SOUTHWEST
ARIZONA.

QPF AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO BE LARGE WITH WPC`S DAY
3 FORECAST VALID FROM 12Z FRI THRU 12Z SAT SHOWING A LARGE SWATH OF
AMOUNTS IN EXCESS OF 0.75 INCHES COVERING MOST OF MY FORECAST
AREA...WITH HIGHER AMOUNTS OVER THE MOUNTAIN RANGES. LESSER AMOUNTS
OUT WEST NEAR AJO...BUT STILL BETWEEN 0.25 AND 0.50 INCHES IN THIS
24 HOUR PERIOD. OF COURSE QPF AMOUNTS WILL END UP BEING EVEN LARGER
THAN THIS GIVEN THAT THIS STORM WILL IMPACT SOUTHEAST ARIZONA FOR
ABOUT 48 HOURS (EARLY THURSDAY EVENING THROUGH LATE SATURDAY
AFTERNOON).

AMOUNTS FOR DESERT AND VALLEY LOCATIONS COULD RANGE FROM AROUND 1.25
TO 1.50 INCHES BY THE TIME ALL IS SAID AND DONE. AS A RESULT...SNOW
AMOUNTS WILL ALSO BE CONSIDERABLE. AT THIS TIME THE BEST THREAT FOR
HEAVY SNOW WILL OCCUR OVER THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY OVER EAST CENTRAL ARIZONA. NEXT IN LINE WILL BE THE PINALENO
MOUNTAINS (MT. GRAHAM) OF SOUTH CENTRAL GRAHAM COUNTY AND THE SANTA
CATALINA MOUNTAINS (MT. LEMMON) AND RINCON MOUNTAINS.

SNOWFALL AMOUNTS DURING THE ENTIRE 48 HOUR STORM TOTAL PERIOD WILL
LIKELY EXCEED 24 INCHES FOR THE WHITE MOUNTAINS...20 TO 24 INCHES
FOR MT. GRAHAM IN THE PINALENO MOUNTAINS AND 12 TO 18 INCHES FOR MT.
LEMMON IN THE SANTA CATALINA MOUNTAINS. THERE IS STILL SOME
UNCERTAINTY REGARDING STORM TOTALS FOR THE CHIRICAHUA MOUNTAINS AS
WELL AS THE REMAINING MOUNTAIN RANGES ACROSS SOUTHEAST ARIZONA NEAR
THE BORDER WITH MEXICO. FOR NOW WILL ISSUE A WINTER STORM WATCH FROM
EARLY FRIDAY MORNING THROUGH MIDDAY SATURDAY FOR THE ELEVATIONS
ABOVE 7000 FEET FOR GRAHAM AND GREENLEE COUNTIES AND THE SANTA
CATALINA MOUNTAINS AND RINCON MOUNTAINS OF EASTERN PIMA COUNTY. AS
MODELS SHED MORE LIGHT ON THIS APPROACHING SYSTEM THIS WATCH MAY BE
EXTENDED TO COVER MORE TERRITORY AND/OR BE UPGRADED IN THE NEXT DAY
OR SO.

THIS SYSTEM WILL FINALLY EXIT THE REGION LATE SATURDAY/EARLY SUNDAY
WITH RIDGING BUILDING IN BEHIND THE SYSTEM FOR WARMING TEMPERATURES
AND A RETURN TO DRY WEATHER. BEGINNING MONDAY...WEAK DISTURBANCES
WILL BRUSH BY TO OUR NORTH...RESULTING IN INTERMITTENT CLOUDINESS...
BUT WE SHOULD REMAIN DRY THROUGH NEXT TUESDAY.

FOR TUCSON...HIGH TEMPERATURES GENERALLY AROUND 10 DEGS ABOVE NORMAL
TODAY AND THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FOR FRIDAY AND
SATURDAY. THEREAFTER...HIGHS WILL HOVER A COUPLE OF DEGREES EITHER
SIDE OF NORMAL. LOWS WILL RANGE FROM 10 TO 12 DEGS ABOVE NORMAL
THURSDAY AND FRIDAY MORNINGS...THEN 6 TO 8 DEGS ABOVE NORMAL FOR
SATURDAY. THEREAFTER...LOWS 1 TO 3 DEGS ABOVE NORMAL.

&&

.AVIATION...VALID THRU 29/12Z.
HIGH CLOUDS WILL BE ON THE INCREASE THROUGH THE PERIOD AND SHOULD
SLOWLY LOWER AS THE UPPER LEVEL TROUGH OFF THE BAJA COAST NEARS THE
FORECAST AREA. THERE IS SOME LOW/MID RESIDUAL MOISTURE IN PLACE THAT
COULD PRODUCE SOME CU DURING THE AFTERNOON HOURS. OTHERWISE...LIGHT
WINDS EXPECTED THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...BENIGN DAY AHEAD AS THE AREA REMAINS BETWEEN TWO
SYSTEMS. TOMORROW HIGH PRESSURE WILL BEGIN TO SETTLE INTO THE SOUTH
PLAINS OF TEXAS. THIS WILL TIGHTEN THE PRESSURE GRADIENT OUT EAST
WHICH WILL ELEVATE WINDS SOME EAST OF TUCSON...ESPECIALLY ACROSS THE
SAN SIMON VALLEY AND GILA RIVER VALLEY. THEN TOMORROW EVENING THE
SYSTEM CURRENTLY OFF THE BAJA COAST WILL PUSH MOISTURE INTO THE AREA
RESULTING IN A BEGINNING OF SHOWER ACTIVITY FOR THE AREA. THIS
SYSTEM WILL USHER IN DEEP MOISTURE FRIDAY MORNING INTO SATURDAY SO
EXPECT WETTING RAINS ACROSS MOST LOCATIONS...WITH SNOW ACROSS THE
HIGHER ELEVATIONS. THE SHOWER ACTIVITY WILL DIMINISH DURING THE
OVERNIGHT SATURDAY. MAX TEMPERATURES WILL DECREASE COMPARED TO LAST
SEVERAL DAYS ON FRIDAY AND GOING INTO THE WEEKEND. HOWEVER...MIN
TEMPERATURES WILL LIKELY REMAIN ABOUT THE SAME UNTIL SUNDAY ONCE
THINGS CLEAR OUT.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM LATE
      THURSDAY NIGHT THROUGH SATURDAY MORNING FOR AZZ510-511-514
      ABOVE 7000 FEET.

&&

$$

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PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...MEADOWS








000
FXUS65 KTWC 281003
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
303 AM MST WED JAN 28 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN SNOW WILL
THEN OCCUR BEGINNING THURSDAY NIGHT AND CONTINUING THROUGH SATURDAY
AS A STORM SYSTEM MOVES ACROSS THE AREA. EXPECT MUCH COOLER DAYTIME
TEMPERATURES WITH THIS SYSTEM. DRY CONDITIONS WILL RETURN EARLY NEXT
WEEK ALONG WITH A WARMING TREND.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 28/00Z UPPER-AIR PLOTS SHOW
RIDGING MOVING BY TO OUR EAST AS A PACIFIC STORM SYSTEM APPROACHES
THE WEST COAST. WE WILL BE DRY THROUGH MUCH OF THURSDAY WITH SOME
HIGH CLOUDINESS MOVING BY FROM TIME TO TIME. THE MAIN STORY WITH
THIS FORECAST PACKAGE WITH BE THE MAJOR STORM SYSTEM THAT WILL
PRODUCE CONSIDERABLE PRECIPITATION AMOUNTS AS IT MOVES ACROSS THE
DESERT SOUTHWEST.

MODELS INDICATE THAT THIS SYSTEM WILL BE MOVING INTO THE WEST COAST
LATE THURSDAY WITH ABUNDANT MOISTURE OUT AHEAD OF THE TROUGH AXIS
MAKING ITS WAY INTO ARIZONA DURING THE DAY ON THURSDAY. ISOLATED
SHOWERS WILL BEGIN TO DEVELOP THURSDAY AFTERNOON...MAINLY OVER THE
HIGHER TERRAIN EAST OF TUCSON. BY THURSDAY EVENING THE LOW WILL
BEGIN TO DEVELOP INTO A CLOSED LOW OVER THE GREAT BASIN...WITH THE
ASSOCIATED TROUGH AXIS EXTENDING SOUTH THROUGH SOUTHERN CALIFORNIA
AND JUST WEST OF THE BAJA PENINSULA. DEEP MOISTURE WILL ALREADY BE
OVER MUCH OF THE DESERT SOUTHWEST BY THAT TIME...INCLUDING MUCH OF
ARIZONA...PARTS OF NEW MEXICO...AS WELL AS PARTS OF UTAH AND NEVADA.
PW`S ARE PROGGED TO INCREASE TO MORE THAN AN INCH EARLY FRIDAY AND
EVEN AROUND 1.25 INCHES ACROSS THE FAR WESTERN DESERTS OF SOUTHWEST
ARIZONA.

QPF AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO BE LARGE WITH WPC`S DAY
3 FORECAST VALID FROM 12Z FRI THRU 12Z SAT SHOWING A LARGE SWATH OF
AMOUNTS IN EXCESS OF 0.75 INCHES COVERING MOST OF MY FORECAST
AREA...WITH HIGHER AMOUNTS OVER THE MOUNTAIN RANGES. LESSER AMOUNTS
OUT WEST NEAR AJO...BUT STILL BETWEEN 0.25 AND 0.50 INCHES IN THIS
24 HOUR PERIOD. OF COURSE QPF AMOUNTS WILL END UP BEING EVEN LARGER
THAN THIS GIVEN THAT THIS STORM WILL IMPACT SOUTHEAST ARIZONA FOR
ABOUT 48 HOURS (EARLY THURSDAY EVENING THROUGH LATE SATURDAY
AFTERNOON).

AMOUNTS FOR DESERT AND VALLEY LOCATIONS COULD RANGE FROM AROUND 1.25
TO 1.50 INCHES BY THE TIME ALL IS SAID AND DONE. AS A RESULT...SNOW
AMOUNTS WILL ALSO BE CONSIDERABLE. AT THIS TIME THE BEST THREAT FOR
HEAVY SNOW WILL OCCUR OVER THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY OVER EAST CENTRAL ARIZONA. NEXT IN LINE WILL BE THE PINALENO
MOUNTAINS (MT. GRAHAM) OF SOUTH CENTRAL GRAHAM COUNTY AND THE SANTA
CATALINA MOUNTAINS (MT. LEMMON) AND RINCON MOUNTAINS.

SNOWFALL AMOUNTS DURING THE ENTIRE 48 HOUR STORM TOTAL PERIOD WILL
LIKELY EXCEED 24 INCHES FOR THE WHITE MOUNTAINS...20 TO 24 INCHES
FOR MT. GRAHAM IN THE PINALENO MOUNTAINS AND 12 TO 18 INCHES FOR MT.
LEMMON IN THE SANTA CATALINA MOUNTAINS. THERE IS STILL SOME
UNCERTAINTY REGARDING STORM TOTALS FOR THE CHIRICAHUA MOUNTAINS AS
WELL AS THE REMAINING MOUNTAIN RANGES ACROSS SOUTHEAST ARIZONA NEAR
THE BORDER WITH MEXICO. FOR NOW WILL ISSUE A WINTER STORM WATCH FROM
EARLY FRIDAY MORNING THROUGH MIDDAY SATURDAY FOR THE ELEVATIONS
ABOVE 7000 FEET FOR GRAHAM AND GREENLEE COUNTIES AND THE SANTA
CATALINA MOUNTAINS AND RINCON MOUNTAINS OF EASTERN PIMA COUNTY. AS
MODELS SHED MORE LIGHT ON THIS APPROACHING SYSTEM THIS WATCH MAY BE
EXTENDED TO COVER MORE TERRITORY AND/OR BE UPGRADED IN THE NEXT DAY
OR SO.

THIS SYSTEM WILL FINALLY EXIT THE REGION LATE SATURDAY/EARLY SUNDAY
WITH RIDGING BUILDING IN BEHIND THE SYSTEM FOR WARMING TEMPERATURES
AND A RETURN TO DRY WEATHER. BEGINNING MONDAY...WEAK DISTURBANCES
WILL BRUSH BY TO OUR NORTH...RESULTING IN INTERMITTENT CLOUDINESS...
BUT WE SHOULD REMAIN DRY THROUGH NEXT TUESDAY.

FOR TUCSON...HIGH TEMPERATURES GENERALLY AROUND 10 DEGS ABOVE NORMAL
TODAY AND THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FOR FRIDAY AND
SATURDAY. THEREAFTER...HIGHS WILL HOVER A COUPLE OF DEGREES EITHER
SIDE OF NORMAL. LOWS WILL RANGE FROM 10 TO 12 DEGS ABOVE NORMAL
THURSDAY AND FRIDAY MORNINGS...THEN 6 TO 8 DEGS ABOVE NORMAL FOR
SATURDAY. THEREAFTER...LOWS 1 TO 3 DEGS ABOVE NORMAL.

&&

.AVIATION...VALID THRU 29/12Z.
HIGH CLOUDS WILL BE ON THE INCREASE THROUGH THE PERIOD AND SHOULD
SLOWLY LOWER AS THE UPPER LEVEL TROUGH OFF THE BAJA COAST NEARS THE
FORECAST AREA. THERE IS SOME LOW/MID RESIDUAL MOISTURE IN PLACE THAT
COULD PRODUCE SOME CU DURING THE AFTERNOON HOURS. OTHERWISE...LIGHT
WINDS EXPECTED THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...BENIGN DAY AHEAD AS THE AREA REMAINS BETWEEN TWO
SYSTEMS. TOMORROW HIGH PRESSURE WILL BEGIN TO SETTLE INTO THE SOUTH
PLAINS OF TEXAS. THIS WILL TIGHTEN THE PRESSURE GRADIENT OUT EAST
WHICH WILL ELEVATE WINDS SOME EAST OF TUCSON...ESPECIALLY ACROSS THE
SAN SIMON VALLEY AND GILA RIVER VALLEY. THEN TOMORROW EVENING THE
SYSTEM CURRENTLY OFF THE BAJA COAST WILL PUSH MOISTURE INTO THE AREA
RESULTING IN A BEGINNING OF SHOWER ACTIVITY FOR THE AREA. THIS
SYSTEM WILL USHER IN DEEP MOISTURE FRIDAY MORNING INTO SATURDAY SO
EXPECT WETTING RAINS ACROSS MOST LOCATIONS...WITH SNOW ACROSS THE
HIGHER ELEVATIONS. THE SHOWER ACTIVITY WILL DIMINISH DURING THE
OVERNIGHT SATURDAY. MAX TEMPERATURES WILL DECREASE COMPARED TO LAST
SEVERAL DAYS ON FRIDAY AND GOING INTO THE WEEKEND. HOWEVER...MIN
TEMPERATURES WILL LIKELY REMAIN ABOUT THE SAME UNTIL SUNDAY ONCE
THINGS CLEAR OUT.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...WINTER STORM WATCH FROM LATE
      THURSDAY NIGHT THROUGH SATURDAY MORNING FOR AZZ510-511-514
      ABOVE 7000 FEET.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...MEADOWS







000
FXUS65 KTWC 280412
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
912 PM MST TUE JAN 27 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN SNOW WILL
THEN OCCUR THURSDAY NIGHT INTO SATURDAY AS A STORM SYSTEM MOVES
ACROSS THE AREA. EXPECT MUCH COOLER DAYTIME TEMPERATURES WITH THIS
SYSTEM. DRY CONDITIONS WILL RETURN EARLY NEXT WEEK ALONG WITH A
WARMING TREND.

&&

.DISCUSSION...THE AREA WILL BE IN BETWEEN WEATHER SYSTEMS TOMORROW
AND PART OF THURSDAY WHICH WILL RESULT IN MORE WELL ABOVE NORMAL
HIGH TEMPERATURES. THIS WILL CHANGE BY LATE THURSDAY...THOUGH...AS
MODELS SHOWED A SYSTEM ENTERING THE REGION AND BRINGING MOUNTAIN
SNOW AND VALLEY RAIN TO SOUTHEAST ARIZONA MAINLY THURSDAY NIGHT INTO
SATURDAY. PWATER VALUES WERE PROGGED TO BE WELL ABOVE NORMAL FOR
THIS TIME OF YEAR BY FRIDAY. SREF PQPF VALUES SUGGESTED THE
POSSIBILITY OF SIGNIFICANT VALLEY RAIN FROM TUCSON TO NOGALES
EASTWARD...ALONG WITH HEAVY SNOWFALL IN THE WHITE MOUNTAINS LIKELY.
CURRENT FORECAST LOOKED ON TRACK FOR NOW SO NO UPDATES NECESSARY
THIS EVENING. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR MORE
DETAILS.

&&

.AVIATION...VALID THRU 29/06Z.
EXPECT A FEW TO BROKEN CLOUDS GENERALLY AROUND 5-9K FT AGL AND
SURFACE WIND LESS THAN 10 KTS THRU WEDNESDAY AFTERNOON. PATCHY FOG
MAY OCCUR FROM KTUS VICINITY NWWD INTO SOUTHERN PINAL COUNTY BETWEEN
09Z-15Z WEDNESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY
MORNING. A STORM SYSTEM WILL THEN BRING VALLEY RAIN AND MOUNTAIN
SNOW LATE THURSDAY THROUGH SATURDAY. EXPECT SIGNIFICANT RAINFALL TO
OCCUR LATE THURSDAY NIGHT INTO FRIDAY NIGHT. SIGNIFICANT SNOWFALL
SHOULD THEN OCCUR LATE FRIDAY INTO SATURDAY. THE WHITE MOUNTAINS AND
MOUNT GRAHAM SHOULD RECEIVE THE MOST SNOWFALL WITH LESSER AMOUNTS
ACROSS THE CATALINA AND RINCON MOUNTAINS NEAR TUCSON. DRY CONDITIONS
WILL RETURN EARLY NEXT WEEK.

&&

.PREV DISCUSSION...VISIBLE SATELLITE IMAGERY INDICATED CLOUDS WERE
GRADUALLY DECREASING ACROSS SE AZ DURING THE PAST 1-2 HOURS IN
RESPONSE TO SUBSIDENCE BEHIND A DEPARTING MID-LEVEL TROUGH AXIS.
EXPECT MOSTLY CLEAR SKIES TO PARTLY CLOUDY SKIES TONIGHT. THERE IS
ENOUGH NEAR-SURFACE MOISTURE TO JUSTIFY PATCHY FOG LATE TONIGHT INTO
EARLY WED MORNING FROM TUCSON WWD INTO THE TOHONO O`ODHAM
NATION...AND NWWD INTO SRN PINAL COUNTY. DRY CONDITIONS WILL
CONTINUE INTO THUR MORNING...ALTHOUGH CLOUDS WILL INCREASE
ESPECIALLY WED NIGHT AND THUR AHEAD OF A DEEPENING LOW PRESSURE
SYSTEM WEST OF THE AREA.

VARIOUS 27/12Z NWP MODEL SOLUTIONS POINT TOWARD A SIGNIFICANT PRECIP
EVENT FOR SE AZ STARTING THUR NIGHT AND CONTINUING INTO SAT. DEEP
LAYER MOISTURE TRANSPORT IS PROGGED TO OCCUR FROM WELL SW OF BAJA
CALIFORNIA NEWD INTO SE AZ. 27/12Z GFS TOTAL PRECIP WATER VALUE FOR
FRI MORNING IS PROGGED TO BE ABOUT 1.10 INCHES. THIS PW VALUE IS 3-4
STANDARD DEVIATIONS ABOVE NORMAL. A 559 DM LOW IS PROGGED VIA THE
GFS/ECMWF TO BE CENTERED NEAR YUMA AZ MIDDAY FRI. THERE IS THE
POTENTIAL FOR SOME LIGHTNING STRIKES TO OCCUR FRI GIVEN THE GFS CAPE
VALUES...AND THE NEGATIVE-TILTED SYSTEM STRUCTURE. HOWEVER...HAVE
PRECLUDED THE DEPICTION/MENTION OF THUNDER FOR NOW. THE UPPER LOW
WILL THEN MOVE VERY SLOWLY EWD INTO SE AZ SAT. THE UPPER LOW IS THEN
PROGGED TO FILL AND MOVE SOUTH TO SOUTHEAST OF THE AREA SUN.

FOR THIS FORECAST PACKAGE...POPS WERE INCREASED LATE THUR NIGHT INTO
FRI NIGHT WITH THE EXPECTATION THIS WILL BE THE PERIOD WHEN
WIDESPREAD RAINFALL WILL OCCUR. SIMILAR RAINFALL COVERAGE IS QUITE
LIKELY TO OCCUR SAT...THOUGH WITH MARKEDLY LESSER AMOUNTS. SNOW
LEVELS BY MIDDAY FRI ARE FORECAST TO GENERALLY BE 8000-8500 FEET...
WITH SNOW LEVELS FALLING TO AROUND 6000-6500 FEET BY SAT EVENING.

PRELIMINARY STORM TOTAL LIQUID AMOUNTS WILL RANGE FROM 0.50 - 1.25
INCHES IN THE VALLEYS...WITH LOCALLY HEAVIER AMOUNTS POSSIBLE.
PRELIMINARY STORM TOTAL SNOW ACCUMULATIONS MAY APPROACH 2 FEET IN
THE WHITE MOUNTAINS ABOVE 7000 FEET...WITH 12-18 INCHES OF SNOWFALL
ABOVE 7000 FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING
MOUNT GRAHAM. LESSER SNOW ACCUMULATIONS SHOULD THEN OCCUR ACROSS THE
CATALINA/RINCON MOUNTAINS NEAR TUCSON. A FEW LINGERING SHOWERS MAY
YET OCCUR SUN PARTICULARLY EAST TO SOUTH OF TUCSON. THEREAFTER...DRY
CONDITIONS WILL PREVAIL SUN NIGHT-TUE.

HIGH TEMPS ACROSS THE AREA WED-THUR WILL AVERAGE ABOUT 5-10 DEGS F
OR SO ABOVE NORMAL. EXPECT NEARLY 10-15 DEGS F OF COOLING FRI
FOLLOWED BY SLIGHTLY COOLER TEMPS SAT. A WARMING TREND WILL THEN
OCCUR SUN-TUE.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PREV DISCUSSION...FRANCIS









000
FXUS65 KTWC 280412
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
912 PM MST TUE JAN 27 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN SNOW WILL
THEN OCCUR THURSDAY NIGHT INTO SATURDAY AS A STORM SYSTEM MOVES
ACROSS THE AREA. EXPECT MUCH COOLER DAYTIME TEMPERATURES WITH THIS
SYSTEM. DRY CONDITIONS WILL RETURN EARLY NEXT WEEK ALONG WITH A
WARMING TREND.

&&

.DISCUSSION...THE AREA WILL BE IN BETWEEN WEATHER SYSTEMS TOMORROW
AND PART OF THURSDAY WHICH WILL RESULT IN MORE WELL ABOVE NORMAL
HIGH TEMPERATURES. THIS WILL CHANGE BY LATE THURSDAY...THOUGH...AS
MODELS SHOWED A SYSTEM ENTERING THE REGION AND BRINGING MOUNTAIN
SNOW AND VALLEY RAIN TO SOUTHEAST ARIZONA MAINLY THURSDAY NIGHT INTO
SATURDAY. PWATER VALUES WERE PROGGED TO BE WELL ABOVE NORMAL FOR
THIS TIME OF YEAR BY FRIDAY. SREF PQPF VALUES SUGGESTED THE
POSSIBILITY OF SIGNIFICANT VALLEY RAIN FROM TUCSON TO NOGALES
EASTWARD...ALONG WITH HEAVY SNOWFALL IN THE WHITE MOUNTAINS LIKELY.
CURRENT FORECAST LOOKED ON TRACK FOR NOW SO NO UPDATES NECESSARY
THIS EVENING. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR MORE
DETAILS.

&&

.AVIATION...VALID THRU 29/06Z.
EXPECT A FEW TO BROKEN CLOUDS GENERALLY AROUND 5-9K FT AGL AND
SURFACE WIND LESS THAN 10 KTS THRU WEDNESDAY AFTERNOON. PATCHY FOG
MAY OCCUR FROM KTUS VICINITY NWWD INTO SOUTHERN PINAL COUNTY BETWEEN
09Z-15Z WEDNESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY
MORNING. A STORM SYSTEM WILL THEN BRING VALLEY RAIN AND MOUNTAIN
SNOW LATE THURSDAY THROUGH SATURDAY. EXPECT SIGNIFICANT RAINFALL TO
OCCUR LATE THURSDAY NIGHT INTO FRIDAY NIGHT. SIGNIFICANT SNOWFALL
SHOULD THEN OCCUR LATE FRIDAY INTO SATURDAY. THE WHITE MOUNTAINS AND
MOUNT GRAHAM SHOULD RECEIVE THE MOST SNOWFALL WITH LESSER AMOUNTS
ACROSS THE CATALINA AND RINCON MOUNTAINS NEAR TUCSON. DRY CONDITIONS
WILL RETURN EARLY NEXT WEEK.

&&

.PREV DISCUSSION...VISIBLE SATELLITE IMAGERY INDICATED CLOUDS WERE
GRADUALLY DECREASING ACROSS SE AZ DURING THE PAST 1-2 HOURS IN
RESPONSE TO SUBSIDENCE BEHIND A DEPARTING MID-LEVEL TROUGH AXIS.
EXPECT MOSTLY CLEAR SKIES TO PARTLY CLOUDY SKIES TONIGHT. THERE IS
ENOUGH NEAR-SURFACE MOISTURE TO JUSTIFY PATCHY FOG LATE TONIGHT INTO
EARLY WED MORNING FROM TUCSON WWD INTO THE TOHONO O`ODHAM
NATION...AND NWWD INTO SRN PINAL COUNTY. DRY CONDITIONS WILL
CONTINUE INTO THUR MORNING...ALTHOUGH CLOUDS WILL INCREASE
ESPECIALLY WED NIGHT AND THUR AHEAD OF A DEEPENING LOW PRESSURE
SYSTEM WEST OF THE AREA.

VARIOUS 27/12Z NWP MODEL SOLUTIONS POINT TOWARD A SIGNIFICANT PRECIP
EVENT FOR SE AZ STARTING THUR NIGHT AND CONTINUING INTO SAT. DEEP
LAYER MOISTURE TRANSPORT IS PROGGED TO OCCUR FROM WELL SW OF BAJA
CALIFORNIA NEWD INTO SE AZ. 27/12Z GFS TOTAL PRECIP WATER VALUE FOR
FRI MORNING IS PROGGED TO BE ABOUT 1.10 INCHES. THIS PW VALUE IS 3-4
STANDARD DEVIATIONS ABOVE NORMAL. A 559 DM LOW IS PROGGED VIA THE
GFS/ECMWF TO BE CENTERED NEAR YUMA AZ MIDDAY FRI. THERE IS THE
POTENTIAL FOR SOME LIGHTNING STRIKES TO OCCUR FRI GIVEN THE GFS CAPE
VALUES...AND THE NEGATIVE-TILTED SYSTEM STRUCTURE. HOWEVER...HAVE
PRECLUDED THE DEPICTION/MENTION OF THUNDER FOR NOW. THE UPPER LOW
WILL THEN MOVE VERY SLOWLY EWD INTO SE AZ SAT. THE UPPER LOW IS THEN
PROGGED TO FILL AND MOVE SOUTH TO SOUTHEAST OF THE AREA SUN.

FOR THIS FORECAST PACKAGE...POPS WERE INCREASED LATE THUR NIGHT INTO
FRI NIGHT WITH THE EXPECTATION THIS WILL BE THE PERIOD WHEN
WIDESPREAD RAINFALL WILL OCCUR. SIMILAR RAINFALL COVERAGE IS QUITE
LIKELY TO OCCUR SAT...THOUGH WITH MARKEDLY LESSER AMOUNTS. SNOW
LEVELS BY MIDDAY FRI ARE FORECAST TO GENERALLY BE 8000-8500 FEET...
WITH SNOW LEVELS FALLING TO AROUND 6000-6500 FEET BY SAT EVENING.

PRELIMINARY STORM TOTAL LIQUID AMOUNTS WILL RANGE FROM 0.50 - 1.25
INCHES IN THE VALLEYS...WITH LOCALLY HEAVIER AMOUNTS POSSIBLE.
PRELIMINARY STORM TOTAL SNOW ACCUMULATIONS MAY APPROACH 2 FEET IN
THE WHITE MOUNTAINS ABOVE 7000 FEET...WITH 12-18 INCHES OF SNOWFALL
ABOVE 7000 FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING
MOUNT GRAHAM. LESSER SNOW ACCUMULATIONS SHOULD THEN OCCUR ACROSS THE
CATALINA/RINCON MOUNTAINS NEAR TUCSON. A FEW LINGERING SHOWERS MAY
YET OCCUR SUN PARTICULARLY EAST TO SOUTH OF TUCSON. THEREAFTER...DRY
CONDITIONS WILL PREVAIL SUN NIGHT-TUE.

HIGH TEMPS ACROSS THE AREA WED-THUR WILL AVERAGE ABOUT 5-10 DEGS F
OR SO ABOVE NORMAL. EXPECT NEARLY 10-15 DEGS F OF COOLING FRI
FOLLOWED BY SLIGHTLY COOLER TEMPS SAT. A WARMING TREND WILL THEN
OCCUR SUN-TUE.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PREV DISCUSSION...FRANCIS










000
FXUS65 KTWC 272230
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
330 PM MST TUE JAN 27 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN
SNOW WILL THEN OCCUR THURSDAY NIGHT INTO SATURDAY AS A STORM SYSTEM
MOVES ACROSS THE AREA. EXPECT MUCH COOLER DAYTIME TEMPERATURES WITH
THIS SYSTEM. DRY CONDITIONS WILL RETURN EARLY NEXT WEEK ALONG WITH A
WARMING TREND.

&&

.DISCUSSION...VISIBLE SATELLITE IMAGERY INDICATED CLOUDS WERE
GRADUALLY DECREASING ACROSS SE AZ DURING THE PAST 1-2 HOURS IN
RESPONSE TO SUBSIDENCE BEHIND A DEPARTING MID-LEVEL TROUGH AXIS.
EXPECT MOSTLY CLEAR SKIES TO PARTLY CLOUDY SKIES TONIGHT. THERE IS
ENOUGH NEAR-SURFACE MOISTURE TO JUSTIFY PATCHY FOG LATE TONIGHT INTO
EARLY WED MORNING FROM TUCSON WWD INTO THE TOHONO O`ODHAM NATION...
AND NWWD INTO SRN PINAL COUNTY. DRY CONDITIONS WILL CONTINUE INTO
THUR MORNING...ALTHOUGH CLOUDS WILL INCREASE ESPECIALLY WED NIGHT
AND THUR AHEAD OF A DEEPENING LOW PRESSURE SYSTEM WEST OF THE AREA.

VARIOUS 27/12Z NWP MODEL SOLUTIONS POINT TOWARD A SIGNIFICANT PRECIP
EVENT FOR SE AZ STARTING THUR NIGHT AND CONTINUING INTO SAT. DEEP
LAYER MOISTURE TRANSPORT IS PROGGED TO OCCUR FROM WELL SW OF BAJA
CALIFORNIA NEWD INTO SE AZ. 27/12Z GFS TOTAL PRECIP WATER VALUE FOR
FRI MORNING IS PROGGED TO BE ABOUT 1.10 INCHES. THIS PW VALUE IS 3-4
STANDARD DEVIATIONS ABOVE NORMAL. A 559 DM LOW IS PROGGED VIA THE
GFS/ECMWF TO BE CENTERED NEAR YUMA AZ MIDDAY FRI. THERE IS THE
POTENTIAL FOR SOME LIGHTNING STRIKES TO OCCUR FRI GIVEN THE GFS CAPE
VALUES...AND THE NEGATIVE-TILTED SYSTEM STRUCTURE. HOWEVER...HAVE
PRECLUDED THE DEPICTION/MENTION OF THUNDER FOR NOW. THE UPPER LOW
WILL THEN MOVE VERY SLOWLY EWD INTO SE AZ SAT. THE UPPER LOW IS THEN
PROGGED TO FILL AND MOVE SOUTH TO SOUTHEAST OF THE AREA SUN.

FOR THIS FORECAST PACKAGE...POPS WERE INCREASED LATE THUR NIGHT INTO
FRI NIGHT WITH THE EXPECTATION THIS WILL BE THE PERIOD WHEN
WIDESPREAD RAINFALL WILL OCCUR. SIMILAR RAINFALL COVERAGE IS QUITE
LIKELY TO OCCUR SAT...THOUGH WITH MARKEDLY LESSER AMOUNTS. SNOW
LEVELS BY MIDDAY FRI ARE FORECAST TO GENERALLY BE 8000-8500 FEET...
WITH SNOW LEVELS FALLING TO AROUND 6000-6500 FEET BY SAT EVENING.

PRELIMINARY STORM TOTAL LIQUID AMOUNTS WILL RANGE FROM 0.50 - 1.25
INCHES IN THE VALLEYS...WITH LOCALLY HEAVIER AMOUNTS POSSIBLE.
PRELIMINARY STORM TOTAL SNOW ACCUMULATIONS MAY APPROACH 2 FEET IN
THE WHITE MOUNTAINS ABOVE 7000 FEET...WITH 12-18 INCHES OF SNOWFALL
ABOVE 7000 FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING
MOUNT GRAHAM. LESSER SNOW ACCUMULATIONS SHOULD THEN OCCUR ACROSS THE
CATALINA/RINCON MOUNTAINS NEAR TUCSON. A FEW LINGERING SHOWERS MAY
YET OCCUR SUN PARTICULARLY EAST TO SOUTH OF TUCSON. THEREAFTER...DRY
CONDITIONS WILL PREVAIL SUN NIGHT-TUE.

HIGH TEMPS ACROSS THE AREA WED-THUR WILL AVERAGE ABOUT 5-10 DEGS F
OR SO ABOVE NORMAL. EXPECT NEARLY 10-15 DEGS F OF COOLING FRI
FOLLOWED BY SLIGHTLY COOLER TEMPS SAT. A WARMING TREND WILL THEN
OCCUR SUN-TUE.

&&

.AVIATION...VALID THRU 29/00Z.
EXPECT A FEW TO BROKEN CLOUDS GENERALLY AROUND 5-9K FT AGL AND
SURFACE WIND LESS THAN 10 KTS THRU WEDNESDAY AFTERNOON. PATCHY FOG
MAY OCCUR FROM KTUS VICINITY NWWD INTO SOUTHERN PINAL COUNTY BETWEEN
09Z-15Z WEDNESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY
MORNING. A STORM SYSTEM WILL THEN BRING VALLEY RAIN AND MOUNTAIN
SNOW LATE THURSDAY THROUGH SATURDAY. EXPECT SIGNIFICANT RAINFALL TO
OCCUR LATE THURSDAY NIGHT INTO FRIDAY NIGHT. SIGNIFICANT SNOWFALL
SHOULD THEN OCCUR LATE FRIDAY INTO SATURDAY. THE WHITE MOUNTAINS AND
MOUNT GRAHAM SHOULD RECEIVE THE MOST SNOWFALL WITH LESSER AMOUNTS
ACROSS THE CATALINA AND RINCON MOUNTAINS NEAR TUCSON. DRY CONDITIONS
WILL RETURN EARLY NEXT WEEK.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS







000
FXUS65 KTWC 272230
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
330 PM MST TUE JAN 27 2015

.SYNOPSIS...DRY CONDITIONS WITH WELL ABOVE NORMAL DAYTIME
TEMPERATURES WILL PREVAIL THROUGH THURSDAY. VALLEY RAIN AND MOUNTAIN
SNOW WILL THEN OCCUR THURSDAY NIGHT INTO SATURDAY AS A STORM SYSTEM
MOVES ACROSS THE AREA. EXPECT MUCH COOLER DAYTIME TEMPERATURES WITH
THIS SYSTEM. DRY CONDITIONS WILL RETURN EARLY NEXT WEEK ALONG WITH A
WARMING TREND.

&&

.DISCUSSION...VISIBLE SATELLITE IMAGERY INDICATED CLOUDS WERE
GRADUALLY DECREASING ACROSS SE AZ DURING THE PAST 1-2 HOURS IN
RESPONSE TO SUBSIDENCE BEHIND A DEPARTING MID-LEVEL TROUGH AXIS.
EXPECT MOSTLY CLEAR SKIES TO PARTLY CLOUDY SKIES TONIGHT. THERE IS
ENOUGH NEAR-SURFACE MOISTURE TO JUSTIFY PATCHY FOG LATE TONIGHT INTO
EARLY WED MORNING FROM TUCSON WWD INTO THE TOHONO O`ODHAM NATION...
AND NWWD INTO SRN PINAL COUNTY. DRY CONDITIONS WILL CONTINUE INTO
THUR MORNING...ALTHOUGH CLOUDS WILL INCREASE ESPECIALLY WED NIGHT
AND THUR AHEAD OF A DEEPENING LOW PRESSURE SYSTEM WEST OF THE AREA.

VARIOUS 27/12Z NWP MODEL SOLUTIONS POINT TOWARD A SIGNIFICANT PRECIP
EVENT FOR SE AZ STARTING THUR NIGHT AND CONTINUING INTO SAT. DEEP
LAYER MOISTURE TRANSPORT IS PROGGED TO OCCUR FROM WELL SW OF BAJA
CALIFORNIA NEWD INTO SE AZ. 27/12Z GFS TOTAL PRECIP WATER VALUE FOR
FRI MORNING IS PROGGED TO BE ABOUT 1.10 INCHES. THIS PW VALUE IS 3-4
STANDARD DEVIATIONS ABOVE NORMAL. A 559 DM LOW IS PROGGED VIA THE
GFS/ECMWF TO BE CENTERED NEAR YUMA AZ MIDDAY FRI. THERE IS THE
POTENTIAL FOR SOME LIGHTNING STRIKES TO OCCUR FRI GIVEN THE GFS CAPE
VALUES...AND THE NEGATIVE-TILTED SYSTEM STRUCTURE. HOWEVER...HAVE
PRECLUDED THE DEPICTION/MENTION OF THUNDER FOR NOW. THE UPPER LOW
WILL THEN MOVE VERY SLOWLY EWD INTO SE AZ SAT. THE UPPER LOW IS THEN
PROGGED TO FILL AND MOVE SOUTH TO SOUTHEAST OF THE AREA SUN.

FOR THIS FORECAST PACKAGE...POPS WERE INCREASED LATE THUR NIGHT INTO
FRI NIGHT WITH THE EXPECTATION THIS WILL BE THE PERIOD WHEN
WIDESPREAD RAINFALL WILL OCCUR. SIMILAR RAINFALL COVERAGE IS QUITE
LIKELY TO OCCUR SAT...THOUGH WITH MARKEDLY LESSER AMOUNTS. SNOW
LEVELS BY MIDDAY FRI ARE FORECAST TO GENERALLY BE 8000-8500 FEET...
WITH SNOW LEVELS FALLING TO AROUND 6000-6500 FEET BY SAT EVENING.

PRELIMINARY STORM TOTAL LIQUID AMOUNTS WILL RANGE FROM 0.50 - 1.25
INCHES IN THE VALLEYS...WITH LOCALLY HEAVIER AMOUNTS POSSIBLE.
PRELIMINARY STORM TOTAL SNOW ACCUMULATIONS MAY APPROACH 2 FEET IN
THE WHITE MOUNTAINS ABOVE 7000 FEET...WITH 12-18 INCHES OF SNOWFALL
ABOVE 7000 FEET FURTHER SWWD ACROSS THE PINALENO MOUNTAINS INCLUDING
MOUNT GRAHAM. LESSER SNOW ACCUMULATIONS SHOULD THEN OCCUR ACROSS THE
CATALINA/RINCON MOUNTAINS NEAR TUCSON. A FEW LINGERING SHOWERS MAY
YET OCCUR SUN PARTICULARLY EAST TO SOUTH OF TUCSON. THEREAFTER...DRY
CONDITIONS WILL PREVAIL SUN NIGHT-TUE.

HIGH TEMPS ACROSS THE AREA WED-THUR WILL AVERAGE ABOUT 5-10 DEGS F
OR SO ABOVE NORMAL. EXPECT NEARLY 10-15 DEGS F OF COOLING FRI
FOLLOWED BY SLIGHTLY COOLER TEMPS SAT. A WARMING TREND WILL THEN
OCCUR SUN-TUE.

&&

.AVIATION...VALID THRU 29/00Z.
EXPECT A FEW TO BROKEN CLOUDS GENERALLY AROUND 5-9K FT AGL AND
SURFACE WIND LESS THAN 10 KTS THRU WEDNESDAY AFTERNOON. PATCHY FOG
MAY OCCUR FROM KTUS VICINITY NWWD INTO SOUTHERN PINAL COUNTY BETWEEN
09Z-15Z WEDNESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DRY CONDITIONS WILL PREVAIL THROUGH THURSDAY
MORNING. A STORM SYSTEM WILL THEN BRING VALLEY RAIN AND MOUNTAIN
SNOW LATE THURSDAY THROUGH SATURDAY. EXPECT SIGNIFICANT RAINFALL TO
OCCUR LATE THURSDAY NIGHT INTO FRIDAY NIGHT. SIGNIFICANT SNOWFALL
SHOULD THEN OCCUR LATE FRIDAY INTO SATURDAY. THE WHITE MOUNTAINS AND
MOUNT GRAHAM SHOULD RECEIVE THE MOST SNOWFALL WITH LESSER AMOUNTS
ACROSS THE CATALINA AND RINCON MOUNTAINS NEAR TUCSON. DRY CONDITIONS
WILL RETURN EARLY NEXT WEEK.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS






000
FXUS65 KTWC 271607
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
905 AM MST TUE JAN 27 2015

.SYNOPSIS...A FEW LINGERING SHOWERS WILL OCCUR MAINLY NORTH OF
TUCSON INTO EARLY THIS AFTERNOON. DRY CONDITIONS WILL THEN PREVAIL
THROUGH WEDNESDAY NIGHT. A STRONGER STORM SYSTEM HOLDS THE POTENTIAL
TO BRING SIGNIFICANT VALLEY RAIN AND MOUNTAIN SNOW STARTING THURSDAY
NIGHT AND CONTINUING INTO THIS WEEKEND.

&&

.DISCUSSION...SCATTERED SHOWERS WERE MOVING NWD ACROSS SOUTH CENTRAL/
SE PINAL COUNTY AT THIS TIME. OTHER ISOLATED SHOWERS WERE ALSO
OCCURRING ACROSS THE TOHONO O`ODHAM NATION WEST OF TUCSON.
OTHERWISE...MOSTLY CLEAR SKIES WERE ONGOING NEAR THE NEW MEXICO
BORDER...AND CLOUDY SKIES PREVAILED ACROSS WRN PIMA COUNTY. A LOW
PRESSURE SYSTEM WAS CENTERED OVER SRN CALIFORNIA WITH MID-LEVEL
TROUGH AXIS EXTENDING SEWD INTO SE AZ. THE UPPER LOW WILL FILL AND
LIFT NEWD INTO THE GREAT BASIN LATER TODAY. MEANWHILE...THE MID-LEVEL
TROUGH AXIS WILL MOVE WELL NE OF THE AREA. THE BULK OF THE SHOWERS
WILL END DURING THE NEXT FEW HOURS...ALTHOUGH A FEW SHOWERS MAY YET
OCCUR INTO THIS AFTERNOON NORTH OF TUCSON. ANY PRECIP IS EXPECTED TO
END BY THIS EVENING FOLLOWED BY DRY CONDITIONS TONIGHT THRU WED
NIGHT. THE FOCUS OF ATTENTION WILL THEN TURN TOWARD A STRONGER LOW
PRESSURE SYSTEM TO DEVELOP OVER THE SWRN CONUS THUR NIGHT AND FRI.
THIS SYSTEM HAS THE POTENTIAL TO BRING SIGNIFICANT VALLEY RAIN AND
MOUNTAIN SNOW INTO THIS WEEKEND. FOR MORE INFORMATION REGARDING THIS
SYSTEM...PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION BELOW.

&&

.AVIATION...VALID THRU 28/18Z.
SCATTERED -SHRA WILL OCCUR MAINLY WEST TO NORTH OF KTUS INTO EARLY
THIS AFTERNOON...WITH ANY SHOWERS TO END BY 28/00Z. OTHERWISE...
CLOUD DECKS INTO WEDNESDAY MORNING WILL GENERALLY BE AROUND
5-9K FT AGL. SURFACE WIND WILL BE LESS THAN 10 KTS THRU THE PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A FEW SHOWERS WILL OCCUR INTO EARLY THIS AFTERNOON
MAINLY WEST TO NORTH OF TUCSON. THEREAFTER...DRY CONDITIONS WILL
PREVAIL THROUGH WEDNESDAY NIGHT. A STRONGER STORM SYSTEM WILL THEN
BRING A GOOD CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW LATE THURSDAY
INTO THIS WEEKEND. GUSTY SOUTHEAST WINDS MAY OCCUR THURSDAY
AFTERNOON AND THURSDAY NIGHT AHEAD OF THIS SYSTEM...ESPECIALLY EAST
OF TUCSON.

&&

.PREV DISCUSSION...AS THIS SYSTEM EXITS TO OUR NORTH WE WILL SEE A
COUPLE OF DAYS OF DRY WEATHER WEDNESDAY AND THURSDAY BEFORE ANOTHER
STRONGER PACIFIC SYSTEM BEGINS TO IMPACT SOUTHEAST ARIZONA LATE
THURSDAY THROUGH THE WEEKEND. MODELS ARE INDICATING THAT THIS NEXT
SYSTEM WILL BE MUCH STRONGER THAN THE ONE CURRENTLY EXITING TO OUR
NORTH. THIS SYSTEM WILL MOVE INTO CENTRAL CALIFORNIA EARLY THURSDAY
WITH THE TROUGH AXIS EXTENDING SOUTHWEST INTO THE PACIFIC WATERS
WEST OF BAJA. PLENTY OF MOISTURE WILL BEGIN STREAMING NORTHEAST
AHEAD OF THE SYSTEM OVER THE DESERT SOUTHWEST AND BY EARLY TO MIDDAY
FRIDAY THE SYSTEM WILL DEVELOP INTO A CLOSED LOW OVER SOUTHERN
NEVADA AND SOUTHERN CALIFORNIA. DEEP MOISTURE AND LIFT IS EXPECTED
TO ACCOMPANY THIS STORM AS EVIDENCED BY TIME HEIGHT SECTIONS. QPF
VALUES WITH THIS STORM ARE EXPECTED TO BE SIGNIFICANT WITH WPC`S
3-DAY QPF FORECAST VALID FROM 12Z THU THROUGH 12Z FRI SHOWING
WIDESPREAD VALUES OF 0.50-0.75 INCHES...WITH A SMALLER AREA OF
AMOUNTS RANGING 0.75-1.0 INCHES OVER MY EASTERN ZONES AS WELL AS
OVER THE HIGHER TERRAIN OF THE MOGOLLON RIM. THE DAY 4-5 FORECAST
VALID FROM 12Z FRI THRU 12Z SUNDAY SHOWS WIDESPREAD AMOUNTS OF
0.50-0.75 INCHES FOR CENTRAL AND EASTERN ZONES WITH PERHAPS 0.75-1.0
INCHES OVER THE HIGHER TERRAIN. MY QPF FORECAST FROM LATE THURSDAY
AFTERNOON THROUGH LATE FRIDAY EVENING (30 HOURS)...SHOWS QPF`S FOR
DESERT/VALLEYS OF THE CENTRAL AND EASTERN ZONES RANGING FROM AROUND
0.6-0.9 INCHES WITH MOUNTAIN LOCATIONS PERHAPS SEEING WATER
EQUIVALENT AMOUNTS RANGING FROM 1.0-1.4 INCHES. QPF`S OVER THE
WESTERN DESERTS...WEST OF TUCSON EXPECTED TO RANGE FROM AROUND
0.2-0.6 INCHES.

SNOW LEVELS ARE EXPECTED TO BOTTOM OUT AT AROUND 6000 FEET BY LATE
SATURDAY INTO EARLY SUNDAY. THE BULK OF THE PRECIPITATION WITH THIS
SYSTEM EXPECTED TO OCCUR FROM THURSDAY EVENING THROUGH MUCH OF THE
DAY FRIDAY...WITH SHOWERS DECREASING SLIGHTLY ON SATURDAY AND
ESPECIALLY BY SUNDAY AS THE TROUGH AXIS WILL EXTEND FROM NORTHERN
NEW MEXICO THROUGH CHIHUAHUA MEXICO. MY SNOW AMOUNT FORECAST FOR THE
PERIOD LATE THURSDAY THROUGH LATE FRIDAY SHOWS AMOUNTS RANGING FROM
AROUND 8 TO 10 INCHES FOR THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY AND THE PINALENO`S OF SOUTH CENTRAL GRAHAM COUNTY...WITH MUCH
LESSER SNOW AMOUNTS FOR THE CATALINA`S AND MOUNTAINS RANGES FARTHER
SOUTH AND EAST. CATALINA`S AND RINCONS ONLY EXPECTED TO SEE PERHAPS
UP TO 6 INCHES. THESE NUMBERS FALL WITHIN ADVISORY CRITERIA...BUT IT
IS TOO EARLY FOR SUCH HEADLINES AT THIS TIME. WE WILL CONTINUE TO
FINE TUNE THE QPF/SNOW FORECAST BETWEEN NOW AND THE ARRIVAL OF THE
STORM...SO STAY TUNED.

FOR TUCSON...HIGH TEMPS GENERALLY 6 TO 8 DEGS ABOVE NORMAL TODAY
THROUGH THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FRIDAY AND
SATURDAY. SLIGHTLY BELOW NORMAL HIGHS EXPECTED SUNDAY AND NEAR
NORMAL FOR MONDAY. LOW TEMPS WILL BE ABOVE NORMAL THROUGHOUT THE
FORECAST PERIOD...BUT THE WARMEST MORNINGS WILL OCCUR THURSDAY AND
FRIDAY.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS
PREVIOUS DISCUSSION...MOLLERE







000
FXUS65 KTWC 271607
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
905 AM MST TUE JAN 27 2015

.SYNOPSIS...A FEW LINGERING SHOWERS WILL OCCUR MAINLY NORTH OF
TUCSON INTO EARLY THIS AFTERNOON. DRY CONDITIONS WILL THEN PREVAIL
THROUGH WEDNESDAY NIGHT. A STRONGER STORM SYSTEM HOLDS THE POTENTIAL
TO BRING SIGNIFICANT VALLEY RAIN AND MOUNTAIN SNOW STARTING THURSDAY
NIGHT AND CONTINUING INTO THIS WEEKEND.

&&

.DISCUSSION...SCATTERED SHOWERS WERE MOVING NWD ACROSS SOUTH CENTRAL/
SE PINAL COUNTY AT THIS TIME. OTHER ISOLATED SHOWERS WERE ALSO
OCCURRING ACROSS THE TOHONO O`ODHAM NATION WEST OF TUCSON.
OTHERWISE...MOSTLY CLEAR SKIES WERE ONGOING NEAR THE NEW MEXICO
BORDER...AND CLOUDY SKIES PREVAILED ACROSS WRN PIMA COUNTY. A LOW
PRESSURE SYSTEM WAS CENTERED OVER SRN CALIFORNIA WITH MID-LEVEL
TROUGH AXIS EXTENDING SEWD INTO SE AZ. THE UPPER LOW WILL FILL AND
LIFT NEWD INTO THE GREAT BASIN LATER TODAY. MEANWHILE...THE MID-LEVEL
TROUGH AXIS WILL MOVE WELL NE OF THE AREA. THE BULK OF THE SHOWERS
WILL END DURING THE NEXT FEW HOURS...ALTHOUGH A FEW SHOWERS MAY YET
OCCUR INTO THIS AFTERNOON NORTH OF TUCSON. ANY PRECIP IS EXPECTED TO
END BY THIS EVENING FOLLOWED BY DRY CONDITIONS TONIGHT THRU WED
NIGHT. THE FOCUS OF ATTENTION WILL THEN TURN TOWARD A STRONGER LOW
PRESSURE SYSTEM TO DEVELOP OVER THE SWRN CONUS THUR NIGHT AND FRI.
THIS SYSTEM HAS THE POTENTIAL TO BRING SIGNIFICANT VALLEY RAIN AND
MOUNTAIN SNOW INTO THIS WEEKEND. FOR MORE INFORMATION REGARDING THIS
SYSTEM...PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION BELOW.

&&

.AVIATION...VALID THRU 28/18Z.
SCATTERED -SHRA WILL OCCUR MAINLY WEST TO NORTH OF KTUS INTO EARLY
THIS AFTERNOON...WITH ANY SHOWERS TO END BY 28/00Z. OTHERWISE...
CLOUD DECKS INTO WEDNESDAY MORNING WILL GENERALLY BE AROUND
5-9K FT AGL. SURFACE WIND WILL BE LESS THAN 10 KTS THRU THE PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A FEW SHOWERS WILL OCCUR INTO EARLY THIS AFTERNOON
MAINLY WEST TO NORTH OF TUCSON. THEREAFTER...DRY CONDITIONS WILL
PREVAIL THROUGH WEDNESDAY NIGHT. A STRONGER STORM SYSTEM WILL THEN
BRING A GOOD CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW LATE THURSDAY
INTO THIS WEEKEND. GUSTY SOUTHEAST WINDS MAY OCCUR THURSDAY
AFTERNOON AND THURSDAY NIGHT AHEAD OF THIS SYSTEM...ESPECIALLY EAST
OF TUCSON.

&&

.PREV DISCUSSION...AS THIS SYSTEM EXITS TO OUR NORTH WE WILL SEE A
COUPLE OF DAYS OF DRY WEATHER WEDNESDAY AND THURSDAY BEFORE ANOTHER
STRONGER PACIFIC SYSTEM BEGINS TO IMPACT SOUTHEAST ARIZONA LATE
THURSDAY THROUGH THE WEEKEND. MODELS ARE INDICATING THAT THIS NEXT
SYSTEM WILL BE MUCH STRONGER THAN THE ONE CURRENTLY EXITING TO OUR
NORTH. THIS SYSTEM WILL MOVE INTO CENTRAL CALIFORNIA EARLY THURSDAY
WITH THE TROUGH AXIS EXTENDING SOUTHWEST INTO THE PACIFIC WATERS
WEST OF BAJA. PLENTY OF MOISTURE WILL BEGIN STREAMING NORTHEAST
AHEAD OF THE SYSTEM OVER THE DESERT SOUTHWEST AND BY EARLY TO MIDDAY
FRIDAY THE SYSTEM WILL DEVELOP INTO A CLOSED LOW OVER SOUTHERN
NEVADA AND SOUTHERN CALIFORNIA. DEEP MOISTURE AND LIFT IS EXPECTED
TO ACCOMPANY THIS STORM AS EVIDENCED BY TIME HEIGHT SECTIONS. QPF
VALUES WITH THIS STORM ARE EXPECTED TO BE SIGNIFICANT WITH WPC`S
3-DAY QPF FORECAST VALID FROM 12Z THU THROUGH 12Z FRI SHOWING
WIDESPREAD VALUES OF 0.50-0.75 INCHES...WITH A SMALLER AREA OF
AMOUNTS RANGING 0.75-1.0 INCHES OVER MY EASTERN ZONES AS WELL AS
OVER THE HIGHER TERRAIN OF THE MOGOLLON RIM. THE DAY 4-5 FORECAST
VALID FROM 12Z FRI THRU 12Z SUNDAY SHOWS WIDESPREAD AMOUNTS OF
0.50-0.75 INCHES FOR CENTRAL AND EASTERN ZONES WITH PERHAPS 0.75-1.0
INCHES OVER THE HIGHER TERRAIN. MY QPF FORECAST FROM LATE THURSDAY
AFTERNOON THROUGH LATE FRIDAY EVENING (30 HOURS)...SHOWS QPF`S FOR
DESERT/VALLEYS OF THE CENTRAL AND EASTERN ZONES RANGING FROM AROUND
0.6-0.9 INCHES WITH MOUNTAIN LOCATIONS PERHAPS SEEING WATER
EQUIVALENT AMOUNTS RANGING FROM 1.0-1.4 INCHES. QPF`S OVER THE
WESTERN DESERTS...WEST OF TUCSON EXPECTED TO RANGE FROM AROUND
0.2-0.6 INCHES.

SNOW LEVELS ARE EXPECTED TO BOTTOM OUT AT AROUND 6000 FEET BY LATE
SATURDAY INTO EARLY SUNDAY. THE BULK OF THE PRECIPITATION WITH THIS
SYSTEM EXPECTED TO OCCUR FROM THURSDAY EVENING THROUGH MUCH OF THE
DAY FRIDAY...WITH SHOWERS DECREASING SLIGHTLY ON SATURDAY AND
ESPECIALLY BY SUNDAY AS THE TROUGH AXIS WILL EXTEND FROM NORTHERN
NEW MEXICO THROUGH CHIHUAHUA MEXICO. MY SNOW AMOUNT FORECAST FOR THE
PERIOD LATE THURSDAY THROUGH LATE FRIDAY SHOWS AMOUNTS RANGING FROM
AROUND 8 TO 10 INCHES FOR THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY AND THE PINALENO`S OF SOUTH CENTRAL GRAHAM COUNTY...WITH MUCH
LESSER SNOW AMOUNTS FOR THE CATALINA`S AND MOUNTAINS RANGES FARTHER
SOUTH AND EAST. CATALINA`S AND RINCONS ONLY EXPECTED TO SEE PERHAPS
UP TO 6 INCHES. THESE NUMBERS FALL WITHIN ADVISORY CRITERIA...BUT IT
IS TOO EARLY FOR SUCH HEADLINES AT THIS TIME. WE WILL CONTINUE TO
FINE TUNE THE QPF/SNOW FORECAST BETWEEN NOW AND THE ARRIVAL OF THE
STORM...SO STAY TUNED.

FOR TUCSON...HIGH TEMPS GENERALLY 6 TO 8 DEGS ABOVE NORMAL TODAY
THROUGH THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FRIDAY AND
SATURDAY. SLIGHTLY BELOW NORMAL HIGHS EXPECTED SUNDAY AND NEAR
NORMAL FOR MONDAY. LOW TEMPS WILL BE ABOVE NORMAL THROUGHOUT THE
FORECAST PERIOD...BUT THE WARMEST MORNINGS WILL OCCUR THURSDAY AND
FRIDAY.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

FRANCIS
PREVIOUS DISCUSSION...MOLLERE






000
FXUS65 KTWC 271107
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
407 AM MST TUE JAN 27 2015

.SYNOPSIS...LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST EARLY THIS
MORNING...TAKING CLOUDS AND SHOWERS AWAY FROM SOUTHEAST ARIZONA.
AFTER A MILD AND SUNNY WEDNESDAY...CLOUDS WILL INCREASE AGAIN
THURSDAY IN ADVANCE OF A MORE POTENT WEATHER SYSTEM WHICH WILL BRING
VALLEY RAIN AND MOUNTAIN SNOW TO THE ARE LATE THURSDAY INTO THE
WEEKEND.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 27/00Z UPPER-AIR PLOTS SHOW
THE UPPER LOW SPINNING IN THE GENERAL VICINITY OF THE COASTAL WATERS
OFF SOUTH CENTRAL CALIFORNIA WITH THE ASSOCIATED TROUGH AXIS
EXTENDING EASTWARD ACROSS SOUTHERN ARIZONA. MID TO UPPER LEVEL DRY
AIR INTRUSION CAN BE SEEN OVER MUCH OF THE EASTERN PACIFIC WATERS...
THE BAJA PENINSULA...GULF OF CALIFORNIA...SONORA AND PARTS OF
SOUTHEAST ARIZONA. IR SATELLITE IMAGERY SHOWS EXTENSIVE CLOUDINESS
COVERING A LARGE PART OF THE STATE...ESPECIALLY OVER CENTRAL AND
NORTHERN ARIZONA WITH LOW TO MID LEVEL CLOUDS GENERALLY FROM TUCSON
TOWARD THE NEW MEXICO BORDER AND BEYOND.

RADAR MOSAIC SHOWS ONLY ISOLATED LINGERING SHOWERS MOSTLY OVER THE
NORTHERN PORTIONS OF MY FORECAST AREA. ALL OF THE SHOWERS WILL
CONTINUE TO MOVE RAPIDLY NORTH AND ARE PRODUCING ONLY VERY LIGHT
RAIN. A LONE SHOWER IS ALSO SOUTHWEST OF THREE POINTS BUT SHOULD
CONTINUE TO MOVE NORTH AND DIMINISH SHORTLY. BASED ON THE LATEST
SATELLITE AND RADAR TRENDS...THE SHOWERS WILL CONTINUE TO MOVE NORTH
THROUGH THE EARLY MORNING HOURS WITH RAIN CHANCES DIMINISHING
RAPIDLY. BASED MY POP FORECAST TODAY LARGELY ON SATELLITE AND RADAR
TRENDS AT THIS TIME. THAT SAID...PROBABLY ONLY LOOKING AT PERHAPS
SLIGHT CHANCES ACROSS THE WHITE MOUNTAINS OF NORTHERN GRAHAM AND
GREENLEE COUNTIES...WITH PRECIPITATION CHANCES DECREASING FURTHER
THROUGHOUT THE DAY. WILL MAKE UPDATES AS NEEDED TO TRIM BACK POPS
THROUGH THE MORNING.

AS THIS SYSTEM EXITS TO OUR NORTH WE WILL SEE A COUPLE OF DAYS OF
DRY WEATHER WEDNESDAY AND THURSDAY BEFORE ANOTHER STRONGER PACIFIC
SYSTEM BEGINS TO IMPACT SOUTHEAST ARIZONA LATE THURSDAY THROUGH THE
WEEKEND. MODELS ARE INDICATING THAT THIS NEXT SYSTEM WILL BE MUCH
STRONGER THAN THE ONE CURRENTLY EXITING TO OUR NORTH. THIS SYSTEM
WILL MOVE INTO CENTRAL CALIFORNIA EARLY THURSDAY WITH THE TROUGH
AXIS EXTENDING SOUTHWEST INTO THE PACIFIC WATERS WEST OF BAJA.
PLENTY OF MOISTURE WILL BEGIN STREAMING NORTHEAST AHEAD OF THE
SYSTEM OVER THE DESERT SOUTHWEST AND BY EARLY TO MIDDAY FRIDAY THE
SYSTEM WILL DEVELOP INTO A CLOSED LOW OVER SOUTHERN NEVADA AND
SOUTHERN CALIFORNIA. DEEP MOISTURE AND LIFT IS EXPECTED TO ACCOMPANY
THIS STORM AS EVIDENCED BY TIME HEIGHT SECTIONS. QPF VALUES WITH
THIS STORM ARE EXPECTED TO BE SIGNIFICANT WITH WPC`S 3-DAY QPF
FORECAST VALID FROM 12Z THU THROUGH 12Z FRI SHOWING WIDESPREAD
VALUES OF 0.50-0.75 INCHES...WITH A SMALLER AREA OF AMOUNTS RANGING
0.75-1.0 INCHES OVER MY EASTERN ZONES AS WELL AS OVER THE HIGHER
TERRAIN OF THE MOGOLLON RIM. THE DAY 4-5 FORECAST VALID FROM 12Z FRI
THRU 12Z SUNDAY SHOWS WIDESPREAD AMOUNTS OF 0.50-0.75 INCHES FOR
CENTRAL AND EASTERN ZONES WITH PERHAPS 0.75-1.0 INCHES OVER THE
HIGHER TERRAIN. MY QPF FORECAST FROM LATE THURSDAY AFTERNOON THROUGH
LATE FRIDAY EVENING (30 HOURS)...SHOWS QPF`S FOR DESERT/VALLEYS OF
THE CENTRAL AND EASTERN ZONES RANGING FROM AROUND 0.6-0.9 INCHES
WITH MOUNTAIN LOCATIONS PERHAPS SEEING WATER EQUIVALENT AMOUNTS
RANGING FROM 1.0-1.4 INCHES. QPF`S OVER THE WESTERN DESERTS...WEST
OF TUCSON EXPECTED TO RANGE FROM AROUND 0.2-0.6 INCHES.

SNOW LEVELS ARE EXPECTED TO BOTTOM OUT AT AROUND 6000 FEET BY LATE
SATURDAY INTO EARLY SUNDAY. THE BULK OF THE PRECIPITATION WITH THIS
SYSTEM EXPECTED TO OCCUR FROM THURSDAY EVENING THROUGH MUCH OF THE
DAY FRIDAY...WITH SHOWERS DECREASING SLIGHTLY ON SATURDAY AND
ESPECIALLY BY SUNDAY AS THE TROUGH AXIS WILL EXTEND FROM NORTHERN
NEW MEXICO THROUGH CHIHUAHUA MEXICO. MY SNOW AMOUNT FORECAST FOR THE
PERIOD LATE THURSDAY THROUGH LATE FRIDAY SHOWS AMOUNTS RANGING FROM
AROUND 8 TO 10 INCHES FOR THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY AND THE PINALENO`S OF SOUTH CENTRAL GRAHAM COUNTY...WITH MUCH
LESSER SNOW AMOUNTS FOR THE CATALINA`S AND MOUNTAINS RANGES FARTHER
SOUTH AND EAST. CATALINA`S AND RINCONS ONLY EXPECTED TO SEE PERHAPS
UP TO 6 INCHES. THESE NUMBERS FALL WITHIN ADVISORY CRITERIA...BUT IT
IS TOO EARLY FOR SUCH HEADLINES AT THIS TIME. WE WILL CONTINUE TO
FINE TUNE THE QPF/SNOW FORECAST BETWEEN NOW AND THE ARRIVAL OF THE
STORM...SO STAY TUNED.

FOR TUCSON...HIGH TEMPS GENERALLY 6 TO 8 DEGS ABOVE NORMAL TODAY
THROUGH THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FRIDAY AND
SATURDAY. SLIGHTLY BELOW NORMAL HIGHS EXPECTED SUNDAY AND NEAR
NORMAL FOR MONDAY. LOW TEMPS WILL BE ABOVE NORMAL THROUGHOUT THE
FORECAST PERIOD...BUT THE WARMEST MORNINGS WILL OCCUR THURSDAY AND
FRIDAY.

&&

.AVIATION...VALID THRU 28/12Z.
SCT-BKN CIGS OF 3-5K FT WITH BKN-OVC CIGS OF 7-10K FT...WITH SOME
MOUNTAINS OBSCURED. ISOLD SHOWERS POSSIBLE...MAINLY THIS MORNING.
THESE CONDITIONS WILL IMPROVE THROUGHOUT THE DAY AS A TROUGH OF LOW
PRESSURE CONTINUES TO MOVE TO THE NORTH. LIGHT EASTERLY SFC WINDS
LESS THAN 10 KTS THIS MORNING BECOMING GENERALLY NORTHWEST TO
SOUTHWEST LATE THIS AFTERNOON...WITH WINDS RESUMING TO NORMAL
DIURNAL TRENDS THIS EVENING THROUGH EARLY WEDNESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EAST TO SOUTHEAST WINDS WILL OCCUR ACROSS MUCH OF
THE AREA THIS MORNING WITH SPEEDS LESS THAN 10 MPH...THEN BECOMING
MORE WESTERLY THIS AFTERNOON. DRY WEATHER WILL RETURN THIS AFTERNOON
THROUGH THURSDAY BEFORE ANOTHER PACIFIC STORM BRINGS A GOOD CHANCE
OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS LATE THURSDAY INTO NEXT
WEEKEND. GUSTY SOUTHEAST WINDS MAY OCCUR THURSDAY AFTERNOON AND
THURSDAY NIGHT AHEAD OF THIS NEXT SYSTEM...ESPECIALLY FOR THE GILA
RIVER VALLEY AND LOCATIONS ADJACENT THE NM BORDER.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

MOLLERE







000
FXUS65 KTWC 271107
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
407 AM MST TUE JAN 27 2015

.SYNOPSIS...LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST EARLY THIS
MORNING...TAKING CLOUDS AND SHOWERS AWAY FROM SOUTHEAST ARIZONA.
AFTER A MILD AND SUNNY WEDNESDAY...CLOUDS WILL INCREASE AGAIN
THURSDAY IN ADVANCE OF A MORE POTENT WEATHER SYSTEM WHICH WILL BRING
VALLEY RAIN AND MOUNTAIN SNOW TO THE ARE LATE THURSDAY INTO THE
WEEKEND.

&&

.DISCUSSION...WATER VAPOR IMAGERY AND 27/00Z UPPER-AIR PLOTS SHOW
THE UPPER LOW SPINNING IN THE GENERAL VICINITY OF THE COASTAL WATERS
OFF SOUTH CENTRAL CALIFORNIA WITH THE ASSOCIATED TROUGH AXIS
EXTENDING EASTWARD ACROSS SOUTHERN ARIZONA. MID TO UPPER LEVEL DRY
AIR INTRUSION CAN BE SEEN OVER MUCH OF THE EASTERN PACIFIC WATERS...
THE BAJA PENINSULA...GULF OF CALIFORNIA...SONORA AND PARTS OF
SOUTHEAST ARIZONA. IR SATELLITE IMAGERY SHOWS EXTENSIVE CLOUDINESS
COVERING A LARGE PART OF THE STATE...ESPECIALLY OVER CENTRAL AND
NORTHERN ARIZONA WITH LOW TO MID LEVEL CLOUDS GENERALLY FROM TUCSON
TOWARD THE NEW MEXICO BORDER AND BEYOND.

RADAR MOSAIC SHOWS ONLY ISOLATED LINGERING SHOWERS MOSTLY OVER THE
NORTHERN PORTIONS OF MY FORECAST AREA. ALL OF THE SHOWERS WILL
CONTINUE TO MOVE RAPIDLY NORTH AND ARE PRODUCING ONLY VERY LIGHT
RAIN. A LONE SHOWER IS ALSO SOUTHWEST OF THREE POINTS BUT SHOULD
CONTINUE TO MOVE NORTH AND DIMINISH SHORTLY. BASED ON THE LATEST
SATELLITE AND RADAR TRENDS...THE SHOWERS WILL CONTINUE TO MOVE NORTH
THROUGH THE EARLY MORNING HOURS WITH RAIN CHANCES DIMINISHING
RAPIDLY. BASED MY POP FORECAST TODAY LARGELY ON SATELLITE AND RADAR
TRENDS AT THIS TIME. THAT SAID...PROBABLY ONLY LOOKING AT PERHAPS
SLIGHT CHANCES ACROSS THE WHITE MOUNTAINS OF NORTHERN GRAHAM AND
GREENLEE COUNTIES...WITH PRECIPITATION CHANCES DECREASING FURTHER
THROUGHOUT THE DAY. WILL MAKE UPDATES AS NEEDED TO TRIM BACK POPS
THROUGH THE MORNING.

AS THIS SYSTEM EXITS TO OUR NORTH WE WILL SEE A COUPLE OF DAYS OF
DRY WEATHER WEDNESDAY AND THURSDAY BEFORE ANOTHER STRONGER PACIFIC
SYSTEM BEGINS TO IMPACT SOUTHEAST ARIZONA LATE THURSDAY THROUGH THE
WEEKEND. MODELS ARE INDICATING THAT THIS NEXT SYSTEM WILL BE MUCH
STRONGER THAN THE ONE CURRENTLY EXITING TO OUR NORTH. THIS SYSTEM
WILL MOVE INTO CENTRAL CALIFORNIA EARLY THURSDAY WITH THE TROUGH
AXIS EXTENDING SOUTHWEST INTO THE PACIFIC WATERS WEST OF BAJA.
PLENTY OF MOISTURE WILL BEGIN STREAMING NORTHEAST AHEAD OF THE
SYSTEM OVER THE DESERT SOUTHWEST AND BY EARLY TO MIDDAY FRIDAY THE
SYSTEM WILL DEVELOP INTO A CLOSED LOW OVER SOUTHERN NEVADA AND
SOUTHERN CALIFORNIA. DEEP MOISTURE AND LIFT IS EXPECTED TO ACCOMPANY
THIS STORM AS EVIDENCED BY TIME HEIGHT SECTIONS. QPF VALUES WITH
THIS STORM ARE EXPECTED TO BE SIGNIFICANT WITH WPC`S 3-DAY QPF
FORECAST VALID FROM 12Z THU THROUGH 12Z FRI SHOWING WIDESPREAD
VALUES OF 0.50-0.75 INCHES...WITH A SMALLER AREA OF AMOUNTS RANGING
0.75-1.0 INCHES OVER MY EASTERN ZONES AS WELL AS OVER THE HIGHER
TERRAIN OF THE MOGOLLON RIM. THE DAY 4-5 FORECAST VALID FROM 12Z FRI
THRU 12Z SUNDAY SHOWS WIDESPREAD AMOUNTS OF 0.50-0.75 INCHES FOR
CENTRAL AND EASTERN ZONES WITH PERHAPS 0.75-1.0 INCHES OVER THE
HIGHER TERRAIN. MY QPF FORECAST FROM LATE THURSDAY AFTERNOON THROUGH
LATE FRIDAY EVENING (30 HOURS)...SHOWS QPF`S FOR DESERT/VALLEYS OF
THE CENTRAL AND EASTERN ZONES RANGING FROM AROUND 0.6-0.9 INCHES
WITH MOUNTAIN LOCATIONS PERHAPS SEEING WATER EQUIVALENT AMOUNTS
RANGING FROM 1.0-1.4 INCHES. QPF`S OVER THE WESTERN DESERTS...WEST
OF TUCSON EXPECTED TO RANGE FROM AROUND 0.2-0.6 INCHES.

SNOW LEVELS ARE EXPECTED TO BOTTOM OUT AT AROUND 6000 FEET BY LATE
SATURDAY INTO EARLY SUNDAY. THE BULK OF THE PRECIPITATION WITH THIS
SYSTEM EXPECTED TO OCCUR FROM THURSDAY EVENING THROUGH MUCH OF THE
DAY FRIDAY...WITH SHOWERS DECREASING SLIGHTLY ON SATURDAY AND
ESPECIALLY BY SUNDAY AS THE TROUGH AXIS WILL EXTEND FROM NORTHERN
NEW MEXICO THROUGH CHIHUAHUA MEXICO. MY SNOW AMOUNT FORECAST FOR THE
PERIOD LATE THURSDAY THROUGH LATE FRIDAY SHOWS AMOUNTS RANGING FROM
AROUND 8 TO 10 INCHES FOR THE WHITE MOUNTAINS OF NORTHERN GREENLEE
COUNTY AND THE PINALENO`S OF SOUTH CENTRAL GRAHAM COUNTY...WITH MUCH
LESSER SNOW AMOUNTS FOR THE CATALINA`S AND MOUNTAINS RANGES FARTHER
SOUTH AND EAST. CATALINA`S AND RINCONS ONLY EXPECTED TO SEE PERHAPS
UP TO 6 INCHES. THESE NUMBERS FALL WITHIN ADVISORY CRITERIA...BUT IT
IS TOO EARLY FOR SUCH HEADLINES AT THIS TIME. WE WILL CONTINUE TO
FINE TUNE THE QPF/SNOW FORECAST BETWEEN NOW AND THE ARRIVAL OF THE
STORM...SO STAY TUNED.

FOR TUCSON...HIGH TEMPS GENERALLY 6 TO 8 DEGS ABOVE NORMAL TODAY
THROUGH THURSDAY...THEN 5 TO 7 DEGS BELOW NORMAL FRIDAY AND
SATURDAY. SLIGHTLY BELOW NORMAL HIGHS EXPECTED SUNDAY AND NEAR
NORMAL FOR MONDAY. LOW TEMPS WILL BE ABOVE NORMAL THROUGHOUT THE
FORECAST PERIOD...BUT THE WARMEST MORNINGS WILL OCCUR THURSDAY AND
FRIDAY.

&&

.AVIATION...VALID THRU 28/12Z.
SCT-BKN CIGS OF 3-5K FT WITH BKN-OVC CIGS OF 7-10K FT...WITH SOME
MOUNTAINS OBSCURED. ISOLD SHOWERS POSSIBLE...MAINLY THIS MORNING.
THESE CONDITIONS WILL IMPROVE THROUGHOUT THE DAY AS A TROUGH OF LOW
PRESSURE CONTINUES TO MOVE TO THE NORTH. LIGHT EASTERLY SFC WINDS
LESS THAN 10 KTS THIS MORNING BECOMING GENERALLY NORTHWEST TO
SOUTHWEST LATE THIS AFTERNOON...WITH WINDS RESUMING TO NORMAL
DIURNAL TRENDS THIS EVENING THROUGH EARLY WEDNESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EAST TO SOUTHEAST WINDS WILL OCCUR ACROSS MUCH OF
THE AREA THIS MORNING WITH SPEEDS LESS THAN 10 MPH...THEN BECOMING
MORE WESTERLY THIS AFTERNOON. DRY WEATHER WILL RETURN THIS AFTERNOON
THROUGH THURSDAY BEFORE ANOTHER PACIFIC STORM BRINGS A GOOD CHANCE
OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS LATE THURSDAY INTO NEXT
WEEKEND. GUSTY SOUTHEAST WINDS MAY OCCUR THURSDAY AFTERNOON AND
THURSDAY NIGHT AHEAD OF THIS NEXT SYSTEM...ESPECIALLY FOR THE GILA
RIVER VALLEY AND LOCATIONS ADJACENT THE NM BORDER.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

MOLLERE






000
FXUS65 KTWC 270347
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
847 PM MST MON JAN 26 2015

.SYNOPSIS...LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST
TONIGHT...TAKING CLOUDS AND SHOWERS AWAY FROM SOUTHEAST ARIZONA.
AFTER A MILD AND SUNNY WEDNESDAY...CLOUDS WILL INCREASE AGAIN
THURSDAY IN ADVANCE OF A MORE POTENT WEATHER SYSTEM WHICH WILL BRING
VALLEY RAIN AND MOUNTAIN SNOW TO THE ARE LATE THURSDAY INTO THE
WEEKEND.

&&

.DISCUSSION...STILL LOOKING AT SOME RAIN SHOWERS ACROSS THE AREA
WHICH SHOULD EVENTUALLY DECREASE IN COVERAGE AND CLEAR LATER
TONIGHT. CURRENT FORECAST WAS HANDLING THESE TRENDS WELL...SO NO
UPDATES NECESSARY THIS EVENING. PLEASE REFER TO THE ADDITIONAL
SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 28/06Z.
SCATTERED -SHRA WILL OCCUR ACROSS SE AZ THRU 27/06Z AFTER WHICH
-SHRA SHOULD END FROM SW TO NE THRU MID-MORNING. OCCASIONAL MVFR
CONDITIONS AND CEILINGS AS LOW AS 4K FT MAY OCCUR NEAR -SHRA. MVFR
VSBYS IN BR AND MT OBSCURATIONS ARE POSSIBLE AFTER DARK INTO TUESDAY
MORNING. EASTERLY SFC WINDS AT 8-12 KTS WILL PREVAIL THROUGH
MID-MORNING TUESDAY WITH DIURNAL TRENDS RESUMING AT ALL TERMINALS
THEREAFTER. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EAST TO SOUTHEAST WINDS WILL OCCUR ACROSS MUCH OF
THE AREA THIS AFTERNOON WITH SPEEDS IN THE 10-15 MPH RANGE...WITH A
FEW HIGHER GUSTS POSSIBLE. SCATTERED SHOWERS WILL BE ENDING FROM
SOUTHWEST TO NORTHEAST TONIGHT. DRY WEATHER WILL RETURN TUESDAY
THROUGH THURSDAY BEFORE ANOTHER PACIFIC STORM BRINGS A GOOD CHANCE
OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS LATE THURSDAY INTO NEXT
WEEKEND. GUSTY SOUTHEAST WINDS MAY OCCUR THURSDAY AFTERNOON AND
THURSDAY NIGHT AHEAD OF THIS NEXT SYSTEM...ESPECIALLY FOR THE GILA
RIVER VALLEY AND LOCATIONS ADJACENT THE NM BORDER.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PREV DISCUSSION...DROZD
AVIATION/FIRE WEATHER...FRENCH











000
FXUS65 KTWC 270347
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
847 PM MST MON JAN 26 2015

.SYNOPSIS...LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST
TONIGHT...TAKING CLOUDS AND SHOWERS AWAY FROM SOUTHEAST ARIZONA.
AFTER A MILD AND SUNNY WEDNESDAY...CLOUDS WILL INCREASE AGAIN
THURSDAY IN ADVANCE OF A MORE POTENT WEATHER SYSTEM WHICH WILL BRING
VALLEY RAIN AND MOUNTAIN SNOW TO THE ARE LATE THURSDAY INTO THE
WEEKEND.

&&

.DISCUSSION...STILL LOOKING AT SOME RAIN SHOWERS ACROSS THE AREA
WHICH SHOULD EVENTUALLY DECREASE IN COVERAGE AND CLEAR LATER
TONIGHT. CURRENT FORECAST WAS HANDLING THESE TRENDS WELL...SO NO
UPDATES NECESSARY THIS EVENING. PLEASE REFER TO THE ADDITIONAL
SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 28/06Z.
SCATTERED -SHRA WILL OCCUR ACROSS SE AZ THRU 27/06Z AFTER WHICH
-SHRA SHOULD END FROM SW TO NE THRU MID-MORNING. OCCASIONAL MVFR
CONDITIONS AND CEILINGS AS LOW AS 4K FT MAY OCCUR NEAR -SHRA. MVFR
VSBYS IN BR AND MT OBSCURATIONS ARE POSSIBLE AFTER DARK INTO TUESDAY
MORNING. EASTERLY SFC WINDS AT 8-12 KTS WILL PREVAIL THROUGH
MID-MORNING TUESDAY WITH DIURNAL TRENDS RESUMING AT ALL TERMINALS
THEREAFTER. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EAST TO SOUTHEAST WINDS WILL OCCUR ACROSS MUCH OF
THE AREA THIS AFTERNOON WITH SPEEDS IN THE 10-15 MPH RANGE...WITH A
FEW HIGHER GUSTS POSSIBLE. SCATTERED SHOWERS WILL BE ENDING FROM
SOUTHWEST TO NORTHEAST TONIGHT. DRY WEATHER WILL RETURN TUESDAY
THROUGH THURSDAY BEFORE ANOTHER PACIFIC STORM BRINGS A GOOD CHANCE
OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS LATE THURSDAY INTO NEXT
WEEKEND. GUSTY SOUTHEAST WINDS MAY OCCUR THURSDAY AFTERNOON AND
THURSDAY NIGHT AHEAD OF THIS NEXT SYSTEM...ESPECIALLY FOR THE GILA
RIVER VALLEY AND LOCATIONS ADJACENT THE NM BORDER.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PREV DISCUSSION...DROZD
AVIATION/FIRE WEATHER...FRENCH










000
FXUS65 KTWC 270347
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
847 PM MST MON JAN 26 2015

.SYNOPSIS...LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST
TONIGHT...TAKING CLOUDS AND SHOWERS AWAY FROM SOUTHEAST ARIZONA.
AFTER A MILD AND SUNNY WEDNESDAY...CLOUDS WILL INCREASE AGAIN
THURSDAY IN ADVANCE OF A MORE POTENT WEATHER SYSTEM WHICH WILL BRING
VALLEY RAIN AND MOUNTAIN SNOW TO THE ARE LATE THURSDAY INTO THE
WEEKEND.

&&

.DISCUSSION...STILL LOOKING AT SOME RAIN SHOWERS ACROSS THE AREA
WHICH SHOULD EVENTUALLY DECREASE IN COVERAGE AND CLEAR LATER
TONIGHT. CURRENT FORECAST WAS HANDLING THESE TRENDS WELL...SO NO
UPDATES NECESSARY THIS EVENING. PLEASE REFER TO THE ADDITIONAL
SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 28/06Z.
SCATTERED -SHRA WILL OCCUR ACROSS SE AZ THRU 27/06Z AFTER WHICH
-SHRA SHOULD END FROM SW TO NE THRU MID-MORNING. OCCASIONAL MVFR
CONDITIONS AND CEILINGS AS LOW AS 4K FT MAY OCCUR NEAR -SHRA. MVFR
VSBYS IN BR AND MT OBSCURATIONS ARE POSSIBLE AFTER DARK INTO TUESDAY
MORNING. EASTERLY SFC WINDS AT 8-12 KTS WILL PREVAIL THROUGH
MID-MORNING TUESDAY WITH DIURNAL TRENDS RESUMING AT ALL TERMINALS
THEREAFTER. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EAST TO SOUTHEAST WINDS WILL OCCUR ACROSS MUCH OF
THE AREA THIS AFTERNOON WITH SPEEDS IN THE 10-15 MPH RANGE...WITH A
FEW HIGHER GUSTS POSSIBLE. SCATTERED SHOWERS WILL BE ENDING FROM
SOUTHWEST TO NORTHEAST TONIGHT. DRY WEATHER WILL RETURN TUESDAY
THROUGH THURSDAY BEFORE ANOTHER PACIFIC STORM BRINGS A GOOD CHANCE
OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS LATE THURSDAY INTO NEXT
WEEKEND. GUSTY SOUTHEAST WINDS MAY OCCUR THURSDAY AFTERNOON AND
THURSDAY NIGHT AHEAD OF THIS NEXT SYSTEM...ESPECIALLY FOR THE GILA
RIVER VALLEY AND LOCATIONS ADJACENT THE NM BORDER.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PREV DISCUSSION...DROZD
AVIATION/FIRE WEATHER...FRENCH











000
FXUS65 KTWC 270347
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
847 PM MST MON JAN 26 2015

.SYNOPSIS...LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST
TONIGHT...TAKING CLOUDS AND SHOWERS AWAY FROM SOUTHEAST ARIZONA.
AFTER A MILD AND SUNNY WEDNESDAY...CLOUDS WILL INCREASE AGAIN
THURSDAY IN ADVANCE OF A MORE POTENT WEATHER SYSTEM WHICH WILL BRING
VALLEY RAIN AND MOUNTAIN SNOW TO THE ARE LATE THURSDAY INTO THE
WEEKEND.

&&

.DISCUSSION...STILL LOOKING AT SOME RAIN SHOWERS ACROSS THE AREA
WHICH SHOULD EVENTUALLY DECREASE IN COVERAGE AND CLEAR LATER
TONIGHT. CURRENT FORECAST WAS HANDLING THESE TRENDS WELL...SO NO
UPDATES NECESSARY THIS EVENING. PLEASE REFER TO THE ADDITIONAL
SECTIONS FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 28/06Z.
SCATTERED -SHRA WILL OCCUR ACROSS SE AZ THRU 27/06Z AFTER WHICH
-SHRA SHOULD END FROM SW TO NE THRU MID-MORNING. OCCASIONAL MVFR
CONDITIONS AND CEILINGS AS LOW AS 4K FT MAY OCCUR NEAR -SHRA. MVFR
VSBYS IN BR AND MT OBSCURATIONS ARE POSSIBLE AFTER DARK INTO TUESDAY
MORNING. EASTERLY SFC WINDS AT 8-12 KTS WILL PREVAIL THROUGH
MID-MORNING TUESDAY WITH DIURNAL TRENDS RESUMING AT ALL TERMINALS
THEREAFTER. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EAST TO SOUTHEAST WINDS WILL OCCUR ACROSS MUCH OF
THE AREA THIS AFTERNOON WITH SPEEDS IN THE 10-15 MPH RANGE...WITH A
FEW HIGHER GUSTS POSSIBLE. SCATTERED SHOWERS WILL BE ENDING FROM
SOUTHWEST TO NORTHEAST TONIGHT. DRY WEATHER WILL RETURN TUESDAY
THROUGH THURSDAY BEFORE ANOTHER PACIFIC STORM BRINGS A GOOD CHANCE
OF VALLEY RAIN AND MOUNTAIN SNOW SHOWERS LATE THURSDAY INTO NEXT
WEEKEND. GUSTY SOUTHEAST WINDS MAY OCCUR THURSDAY AFTERNOON AND
THURSDAY NIGHT AHEAD OF THIS NEXT SYSTEM...ESPECIALLY FOR THE GILA
RIVER VALLEY AND LOCATIONS ADJACENT THE NM BORDER.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

PREV DISCUSSION...DROZD
AVIATION/FIRE WEATHER...FRENCH










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