Expires:No;;356240 FPUS55 KFGZ 021707 ZFPFGZ AREA FORECAST DISCUSSION...MORNING UPDATE NATIONAL WEATHER SERVICE FLAGSTAFF AZ 1005 AM MST WED APR 2 2008 .SYNOPSIS...A PACIFIC LOW PRESSURE SYSTEM WILL APPROACH THE AREA TODAY...BRINGING STRONGER WINDS...AND A CHANCE OF RAIN AND SNOW SHOWERS LATER THIS EVENING AND INTO THURSDAY. FRIDAY THROUGH THE WEEKEND...EXPECT DRY WEATHER AND WARMER TEMPERATURES WITH BREEZY AFTERNOON WINDS. && .DISCUSSION...HIGH CLOUDS APPROACHING FROM THE WEST WILL HELP INCREASE CLOUD COVER LATER TODAY. A SYSTEM APPROACHING THE CALIFORNIA COAST IS RESPONSIBLE FOR THE HIGH CLOUDS AND THE BREEZY AFTERNOON SOUTHWEST WINDS OVER THE WESTERN HALF OF THE FORECAST AREA AND WINDY CONDITIONS OVER THE EASTERN HALF. DUE TO THE DRY AND WINDY CONDITIONS THIS AFTERNOON A RED FLAG WARNING REMAINS IN EFFECT FOR THE EASTERN LITTLE COLORADO RIVER VALLEY ZONES FROM 12P MST TO 7P MST. THE WEAK LOW PRESSURE SYSTEM IS FORECAST TO MOVE ON SHORE AND ACROSS CALIFORNIA OVERNIGHT AND THEN OVER ARIZONA ON THURSDAY. LATEST MODEL FORECASTS HAVE DIMINISHED ANY CHANCES OF RAIN ACROSS THE AREA...MAINLY BECAUSE THE SYSTEM IS MUCH WEAKER OPEN WAVE. WE WILL LIKELY REDUCE PRECIP CHC'S ON THE AFTERNOON FORECAST PACKAGE. NO UPDATES PLANNED FOR THE TODAY PORTIONS OF THE GRIDDED AND ZONE FORECAST. && .PREVIOUS DISCUSSION /230 AM MST/...SOUTHERLY FLOW IS APPARENT ON SATELLITE THIS MORNING AS HIGH CIRRUS CLOUDS CONTINUE TO MOVE IN FROM THE SOUTHWEST. OFF THE COAST OF CALIFORNIA...AN AREA OF LOW PRESSURE WILL BEGIN TO MOVE ONSHORE LATER TODAY. THIS WILL CAUSE AN INCREASE IN CLOUDINESS OVER THE AREA. STRONG SOUTHWEST WINDS AT 700MB COUPLED WITH A TIGHTENING PRESSURE GRADIENT WILL ALLOW FOR WINDY CONDITIONS ACROSS THE FORECAST AREA. IT LOOKS AS IF WINDS WILL REMAIN BELOW ADVISORY CRITERIA FOR MOST LOCATIONS...BUT WE COULD SEE A FEW ISOLATED LOCALES HIT THE 40 MPH MARK SOMETIME IN THE AFTERNOON...PROBABLY IN THE LITTLE COLORADO RIVER VALLEY. THEREFORE...AN ADVISORY HAS NOT BEEN ISSUED. SHOWERY TYPE PRECIPITATION IS EXPECTED WITH THIS SYSTEM AND IT IS ANTICIPATED TO START LATER TONIGHT AND TOMORROW MORNING. BEST CHANCES WILL BE OVER THE HIGH TERRAIN OVER THE WESTERN HALF OF THE FORECAST AREA LATE TONIGHT...AND AS THE TROUGH PUSHES ACROSS THE STATE...THE BEST CHANCES WILL TRANSITION TO THE EASTERN HALF BY THURSDAY MORNING AND AFTERNOON. 850-500MB LAPSE RATES STEEPEN RAPIDLY AS COLD AIR ALOFT PUSHES EAST WITH THE TROUGH. THEREFORE...HAVE INCREASED CHANCES FOR PRECIPITATION OVER THE EASTERN PORTIONS OF THE FORECAST AREA FOR THIS TIME PERIOD. AGAIN...NOT LOOKING FOR SIGNIFICANT PRECIPITATION AMOUNTS BUT MORE ALONG THE LINES OF SHOWERS. BY LATER THURSDAY AND FRIDAY A RIDGE BEGINS TO BUILD INTO THE AREA AND SKIES WILL CLEAR OUT. AFTERNOON TEMPERATURES WILL WARM BUT BREEZY NORTHWEST WINDS WILL CONTINUE. A TROUGH IS EXPECTED TO PASS OVER THE NORTHERN ROCKIES LATE IN THE WEEKEND. THE RESULT WILL BE AN INCREASE IN WINDS AND MAYBE SOME MORE CLOUDS OVER THE NORTHERN ZONES BUT THAT IS ABOUT IT. MODELS ARE HINTING AT ANOTHER TROUGH BY THE BEGINNING TO MID-WEEK PERIOD NEXT WEEK. WILL CONTINUE TO KEEP SLIGHT CHANCE POPS IN THE EXTENDED FOR NOW TO COVER. && ..AVIATION...FOR THE 18Z PACKAGE...EXPECT MOSTLY CLEAR SKIES INTO THIS EVENING. SOUTHWEST WINDS OF 15 TO 25 KT WILL MOST AREAS BY THE AFTERNOON AS A PACIFIC LOW PRESSURE SYSTEM SLOWLY APPROACHES. BY EARLY THURSDAY...CLOUDS WILL INCREASE AS THE PACIFIC LOW MOVES OVER THE SOUTHWEST UNITED STATES. A CHANCE OF SHOWERS WILL DEVELOP FROM FLAGSTAFF WESTWARD BY AROUND 12Z THURSDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && .FIRE WEATHER...RED FLAG WARNING TODAY FROM NOON UNTIL 700 PM MST FOR FIRE WEATHER ZONES 113 AND 114. AN APPROACHING LOW PRESSURE SYSTEM WILL BRING AFTERNOON SOUTHWEST WINDS OF 15 TO 25 MPH WITH STRONGER GUSTS. MINIMUM RELATIVE HUMIDITY VALUES FROM THE MOGOLLON RIM SOUTH AND WEST WILL GENERALLY BE HIGHER THAN ON TUESDAY WITH COOLER TEMPERATURES AND DEW POINT INCREASES. HOWEVER...ACROSS THE LITTLE COLORADO RIVER VALLEY AND MUCH OF NORTHEAST ARIZONA...EXPECT THAT RELATIVE HUMIDITY VALUES WILL DROP BELOW 15 PERCENT FOR MUCH OF THIS AFTERNOON. WIND AND RELATIVE HUMIDITY VALUES FOR CRITICAL FIRE WEATHER CONDITIONS WILL BE MOST FAVORABLE ACROSS THE CENTRAL AND EASTERN PORTIONS OF THE LITTLE COLORADO RIVER VALLEY. FOR THURSDAY...THE WEAK LOW PRESSURE SYSTEM WILL MOVE ACROSS ARIZONA AND BRING INCREASING MOISTURE...A CHANCE OF SHOWERS AND WEAKER WINDS WITH LITTLE IN THE WAY OF FIRE WEATHER ISSUES. HEADING INTO THE WEEKEND...A GENERAL NORTHWEST FLOW WILL SET UP ACROSS NORTHERN ARIZONA WITH LOWER RELATIVE HUMIDITY VALUES BUT DAYTIME WINDS OF ONLY 10 TO 20 MPH. && .FGZ WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING FROM 1200 PM THIS AFTERNOON UNTIL 700 PM MST THIS EVENING FOR FIRE WEATHER ZONES 113 AND 114. && $$ PUBLIC...TC AVIATION/FIRE WEATHER...MAS VISIT WEATHER.GOV/FLAGSTAFF FOR MORE NORTHERN ARIZONA WEATHER INFORMATION.