AREA FORECAST DISCUSSION

 
 FXUS65 KTWC 140410
 AFDTWC
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE TUCSON AZ
 910 PM MST MON FEB 13 2012
 
 .SYNOPSIS...A COUPLE OF WEATHER SYSTEMS WILL BRING A CHANCE OF 
 VALLEY RAIN AND MOUNTAIN SNOW SHOWERS TO SOUTHEAST ARIZONA TUESDAY 
 AND THURSDAY. GUSTY WINDS AND COOLER TEMPERATURES WILL ACCOMPANY 
 EACH SYSTEM. DRY CONDITIONS WILL RETURN THIS WEEKEND WITH A WARMING 
 TREND.
 
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 .DISCUSSION...IR SATELLITE IMAGERY INDICATED MID-LEVEL CLOUDS TO BE 
 INCREASING ACROSS SE AZ DURING THE PAST 2-3 HOURS. ALSO...CLOUD TOPS 
 WERE COOLING ACROSS FAR SWRN AZ SINCE 14/01Z. HOWEVER...PRECIP 
 ECHOES WERE WELL NW OF THIS FORECAST AREA ACROSS FAR NWRN AZ AND SRN 
 NEVADA. UPPER LOW CENTERED JUST WEST OF LAS VEGAS NV AT THIS TIME 
 WILL MOVE EWD INTO NWRN AZ EARLY TUE MORNING. SYSTEM TO THEN MOVE 
 EWD TO THE FOUR CORNERS REGION TUE EVENING.
 
 HAVE NOTED THAT THE 14/00Z NAM HAS LOWERED THE CHANCES OF MEASURABLE 
 PRECIP MARKEDLY VERSUS PREVIOUS SOLUTIONS. NAM DEPICTED THE ONSET OF 
 PRECIP TO OCCUR ACROSS THE WHITE MOUNTAINS LATE TONIGHT WITH DRY 
 CONDITIONS ELSEWHERE. NAM PROGGED LIQUID AMOUNTS OF JUST A FEW 
 HUNDREDTHS OF AN INCH TO OCCUR TUE FROM THE CATALINA MOUNTAINS NEWD 
 TO THE WHITE MOUNTAINS WITH DRY CONDITIONS ELSEWHERE.
 
 AT ANY RATE...GIVEN SATELLITE TRENDS AND ANALYSES OF THE 14/00Z 
 UPPER AIR PLOTS...STILL BELIEVE HEIGHT FALLS ASSOCIATED WITH THIS 
 SYSTEM WILL BE SUFFICIENT TO MAINTAIN GENERALLY CHANCE-CATEGORY POPS 
 MOST SECTIONS TUE. WILL DEFER TO THE MIDNIGHT SHIFT TO MAKE ANY 
 ADJUSTMENTS TO THE OFFICIAL FORECAST. GRIDDED DATA SKY FIELDS WERE 
 UPDATED TO DEPICT MOSTLY CLOUDY SKIES MOST SECTIONS THE REST OF 
 TONIGHT. PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION BELOW FOR 
 ADDITIONAL DETAIL.
 
 &&
 
 .AVIATION...CLOUD DECKS GENERALLY 4-8K FT AGL THRU TUESDAY EVENING 
 OR 15/06Z. ISOLD -SHRA DEVELOPING NEAR THE WHITE MOUNTAINS BY 
 DAYBREAK. SCT-NUMEROUS -SHRA AND HIGHER TERRAIN -SHSN TUE. PRECIP 
 ENDING FROM W-E TUE EVENING. SLY/SWLY SURFACE WIND GENERALLY LESS 
 THAN 10 KTS THRU 16Z TUE. THEREAFTER...SURFACE WIND SWLY/WLY 10-25 
 KTS WITH GUSTS OF 25-35 KTS 17Z-23Z TUE. SURFACE WIND DIMINISHING TO 
 LESS THAN 10 KTS BY 15/06Z. AVIATION DISCUSSION NOT UPDATED FOR TAF 
 AMENDMENTS.
 
 &&
 
 .FIRE WEATHER...THE ACTIVE WEATHER PATTERN WILL CONTINUE THIS WEEK 
 WITH THE NEXT LOW PRESSURE SYSTEM MOVING THROUGH TUESDAY. THIS WILL 
 BRING MORE GUSTY WINDS ESPECIALLY ACROSS GRAHAM/GREENLEE AND COCHISE 
 COUNTIES...AND A CHANCE OF SHOWERS AS WELL AS MUCH COOLER 
 TEMPERATURES. ANOTHER SYSTEM WILL MOVE THROUGH THE AREA THURSDAY 
 WITH THE POTENTIAL FOR MORE PRECIPITATION.
 
 &&
 
 .DISCUSSION...MODELS WERE IN PRETTY GOOD AGREEMENT WITH TRACKING THE 
 NEXT SYSTEM INTO THE STATE LATE TONIGHT AND TUESDAY. MOISTURE STILL 
 APPEARED TO BE SOMEWHAT LIMITED WITH THE SYSTEM THIS FAR SOUTH...BUT 
 STILL LOOKING AT A DECENT CHANCE OF PRECIPITATION MOST AREAS... 
 ALTHOUGH LIGHT. WIND AND SOME SNOW ACCUMULATIONS IN THE MOUNTAINS... 
 ESPECIALLY THE WHITE MOUNTAINS...WILL BE THE MAIN CONCERNS. WIND 
 SPEEDS MIGHT BE STRONG ENOUGH TO GENERATE BLOWING DUST ACROSS PARTS 
 OF COCHISE COUNTY. LATER SHIFTS MAY NEED TO CONSIDER A WIND ADVISORY 
 FOR PARTS OF COCHISE COUNTY...BUT PROJECTED SPEEDS ON THE AFTERNOON 
 FORECAST PACKAGE WILL BE BELOW ADVISORY THRESHOLDS. THUS...WILL NOT 
 POST ONE AT THIS TIME. MODELS WERE IN BETTER AGREEMENT TODAY WITH 
 THE THURSDAY SYSTEM THAT WAS PROGGED TO TRACK THROUGH SOUTHERN 
 CALIFORNIA WEDNESDAY AFTERNOON...THEN MOVE EASTWARD OVER THE 
 INTERNATIONAL BORDER THURSDAY. NOT SURE THIS SYSTEM WILL HAVE MUCH 
 MOISTURE TO WORK WITH...SO WILL KEEP THE LOW POP VALUES GOING FOR 
 NOW. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR MORE DETAILS. 
  
 &&
 
 .TWC WATCHES/WARNINGS/ADVISORIES...NONE.
 
 

 
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