####018002605#### FXUS65 KBOI 141710 AFDBOI AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 1000 AM MST SAT FEB 14 2009 .DISCUSSION...UPPER TROUGH AXIS STRETCHES FROM THE PACIFIC NORTHWEST COAST TO UTAH...AND EXTENDS OVER THE AREA. SCATTERED TO NUMEROUS SNOW SHOWERS WILL CONTINUE THROUGH THIS AFTERNOON AS THE UPPER TROUGH AND ASSOCIATED INSTABILITY LIFT NORTHEAST THROUGH THE REGION. AN AREA OF ORGANIZED CONVECTION WAS LOCATED IN HARNEY COUNTY PER SATELLITE IMAGERY. THIS IS CONFIRMED AT THE BURNS AIRPORT AND WEBCAMS LOCATED IN BURNS WHERE LIGHT SNOW CONTINUES. MORNING UPDATE WILL INCLUDE HIGHER POPS IN HARNEY COUNTY TODAY. && .AVIATION...MAINLY VFR CONDITIONS TODAY THROUGH SE OREGON AND SW IDAHO WITH WIDELY SCATTERED SNOW SHOWERS THROUGH THIS EVENING CAUSING MVFR CONDITIONS AND MOUNTAIN OBSCURATION. SURFACE WINDS WILL BE LIGHT TODAY WITH 15-20 KT GUSTS IN SE OREGON AND THROUGH THE SW HIGHLANDS IN IDAHO. SW WINDS ALOFT ARE MODERATE. THERE WILL BE A BRIEF BREAK IN THE PRECIPITATION OVERNIGHT BEFORE ANOTHER SYSTEM MOVES INTO THE AREA SUNDAY BRINGING GUSTY SE-SW WINDS AND A CHANCE OF PRECIPITATION. && .PREV DISCUSSION... SHORT TERM...TODAY THROUGH SATURDAY NIGHT...CURRENT SATELLITE AND RADAR TRENDS PLACE PRELIMINARY SHORT WAVE INTO THE BOISE MOUNTAINS WHERE OROGRAPHICALLY ENHANCED SNOW SHOWERS ARE REDEVELOPING. BEHIND THIS FEATURE A DRY SLOT IS ALLOWING SOME CLEARING ALONG WITH FREEZING FOG IN BURNS WHERE ABOUT AN INCH OF SNOW FELL OVERNIGHT. THE MAIN TROUGH AXIS WILL MOVE NORTHEAST ACROSS THE FORECAST AREA TODAY WITH SCATTERED SNOW SHOWERS ADDING UP TO ONLY AN INCH OR TWO...ALONG WITH SOME BANDED SNOW SHOWERS IN THE UPPER TREASURE VALLEY THIS AFTERNOON. THIS TROUGH DAMPEN OUT TONIGHT AS IT RETROGRADES INTO THE PARENT LOW PRESSURE SYSTEM OFF THE PACIFIC COAST. LONG TERM...SUNDAY THROUGH FRIDAY...THE OVERALL TREND WILL BE FOR THE LOW NEAR THE NORTHERN CALIFORNIA COAST TO HAVE A SIGNIFICANT WAVE EJECT OUT OF IT ACROSS THE GREAT BASIN MONDAY NIGHT/TUESDAY. AN AMPLIFYING RIDGE ACROSS THE SOUTH CENTRAL U.S. WILL KEEP THE LONG WAVE TROUGH OFFSHORE RESULTING IN A REDUCED THREAT OF PRECIPITATION AND SLIGHTLY WARMER TEMPERATURES THEREAFTER. THE MOST SIGNIFICANT WEATHER EVENT FOR THE WEEK WILL BE THE MONDAY NIGHT/TUESDAY PRECIPITATION. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && $$ WEATHER.GOV/BOISE DISCUSSION...BW AVIATION.....DF PREV SHORT TERM...CD PREV LONG TERM....VM ####018004166#### FXUS64 KLZK 141710 AFDLZK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LITTLE ROCK AR 1110 AM CST SAT FEB 14 2009 .AVIATION... MVFR CIGS ALONG THE MISSOURI BORDER WILL CONTINUE TO DECREASE IN COVERAGE DURING THE EARLY AFTERNOON HOURS. 55 && .PREV DISCUSSION... /ISSUED 540 AM CST SAT FEB 14 2009/ AVIATION... AREAS OF MVFR CEILINGS WILL BE SEEN ACROSS NORTHERN AND CENTRAL PARTS OF AR THIS MORNING...BEHIND THE COLD FRONT THAT CONTINUES TO MOVE SOUTHEAST ACROSS AR. VFR CEILINGS OVER SOUTHERN AREAS WITH PATCHY MVFR CEILINGS. NORTHWEST WINDS 5 TO 15 MPH EXPECTED...WITH SOME GUSTS TO 20 MPH. THIS AFTERNOON...EXPECT MVFR CEILINGS TO THIN AND RAISE TO VFR CONDITIONS. (60) PREV DISCUSSION... /ISSUED 247 AM CST SAT FEB 14 2009/ DISCUSSION... MAIN CONCERNS THIS FORECAST CYCLE ARE ANY CHANCES OF PRECIP SATURDAY OVERNIGHT WITH SHORTWAVE...THEN NEXT CHANCE OF RAIN TUESDAY. COLD FRONT DRIFTING ACROSS AR THIS EARLY MORNING...GENERALLY AT 08Z JUST EAST OF KTXK...KLIT TO NEAR KJBR. VERY ISOLATED LIGHT SHOWERS MAINLY WELL AHEAD OF THE FRONT...MAINLY ASSOCIATED WITH UPPER SHORTWAVE. COVERAGE AND AMOUNTS HAVE BEEN VERY LOW. SEEING SOME ELEVATED WINDS BEHIND THE FRONT...BUT NOT EXPECTING LAKE WIND ADVISORY. BREAK IN CLOUDS RIGHT BEHIND THE FRONT...BUT STRATUS DECK A BIT FARTHER BEHIND AND MORE ASSOCIATED WITH THE SURFACE LOW AND WRAP AROUND MOISTURE AND CLOUDS. DO EXPECT THESE CLOUDS TO GRADUALLY DISSIPATE THROUGH THE DAY. 00Z KLZK SOUNDING HAD SATURATION AROUND 5K FT. UPPER FLOW REMAINS ZONAL WITH THE ACTIVE SOUTHERN STREAM. SHORT TERM...TODAY THROUGH TUESDAY NIGHT WILL NOT INCLUDE ANY EARLY PRECIP IN FORECAST WITH MOST PUSHING EAST AND ONLY SOME SPRINKLES MAY BE SEE WITH ACTUAL FRONT. WIND SHIFT SHOULD BE OVER THE ENTIRE CWA SO WINDS WILL BE NORTHWEST. AS STATED...WINDS WILL BE ELEVATED THIS MORNING...BUT GRADIENT DOES LOOSEN INTO THE AFTERNOON. ALSO MORNING CLOUDS SHOULD GRADUALLY DISSIPATE BY AFTERNOON...WHILE NORTH TO NORTHEAST MAY HOLD A BIT LONGER. TEMPS WILL BE COOLER TODAY BY 5 TO 10 DEGREES. SURFACE RIDGE DOES BUILD IN OVER THE AREA REST OF TODAY. HAVE KEPT SLIGHT CHANCE OF RAIN AND CLOUDS OVER SOUTHERN PARTS OF AR FOR LATE SATURDAY TO SUNDAY MORNING...THEN THIS FEATURE MOVES EAST BY SUNDAY AFTERNOON. ON MONDAY...SURFACE RIDGE GRADUALLY MOVES EAST AS UPPER RIDGING HELPS MODERATE TEMPS. INTO TUESDAY...RETURN FLOW SETS UP OVER THE SOUTHERN PLAINS...AS THE SURFACE HIGH HAS SIFTED EAST. UPPER SOUTHERN STREAM REMAINS ACTIVE WITH A SYSTEM DEVELOPING IN THE WESTERN PLAINS...WITH A COLD FRONT. UPPER ENERGY ACCOMPANIES THE TUESDAY SYSTEM...BUT THE UPPER LOW AND SURFACE LOW STAY WELL NORTH OF AR...SO OVERALL CONVECTION WILL BE LIMITED IN STRENGTH AND COVERAGE. LONG TERM...WEDNESDAY THROUGH FRIDAY NIGHT ZONAL FLOW WILL BE IN PLACE THROUGH MOST OF THE PERIOD...BEFORE NORTHWEST FLOW SETS UP ON FRIDAY. MOISTURE LOOKS TO REMAIN LIMITED DURING THE LONG TERM...SO LEFT FORECAST DRY THROUGH THE END OF THE WORK WEEK. A WIND SHIFT WILL OCCUR ON WEDNESDAY...AS A FRONTAL BOUNDARY MOVES THROUGH THE AREA. TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL ON WEDNESDAY...FALLING TO SLIGHTLY BELOW NORMAL TEMPERATURES FOR THE END OF THE WORK WEEK. && .PRELIMINARY POINT TEMPS/POPS... BATESVILLE AR 52 33 48 27 / 0 10 10 10 CAMDEN AR 60 39 57 33 / 0 20 10 0 HARRISON AR 48 29 44 25 / 0 10 10 10 HOT SPRINGS AR 57 35 53 31 / 0 10 10 0 LITTLE ROCK AR 56 36 52 30 / 0 10 10 10 MONTICELLO AR 59 39 57 33 / 10 20 10 0 MOUNT IDA AR 56 34 52 31 / 0 10 10 0 MOUNTAIN HOME AR 49 30 45 25 / 0 10 10 10 NEWPORT AR 53 34 49 29 / 0 10 10 10 PINE BLUFF AR 58 38 54 32 / 0 20 10 0 RUSSELLVILLE AR 54 34 49 28 / 0 10 10 10 SEARCY AR 54 35 49 29 / 0 10 10 10 STUTTGART AR 56 37 52 31 / 0 10 10 10 && .LZK WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AVIATION...99 ####018002616#### FXUS63 KLSX 141712 AFDLSX AREA FORECAST DISCUSSION...UPDATED AVIATION NATIONAL WEATHER SERVICE ST LOUIS MO 1112 AM CST SAT FEB 14 2009 .DISCUSSION... /427 AM CST SAT FEB 14 2009/ SYSTEM THAT MOVED INTO AREA FRI EVENING PRODUCED AN INCH OR TWO OF SNOW NW OF UIN. SINCE 06Z...PCPN HAS BEEN LIMITED TO A FEW FLURRIES IN N SECTIONS OF THE CWA...ALONG WITH SM SPOTTY DRZL/FRZG DRZL IN CNTRL MO. WL CONT TO MONITOR SFC OBS FOR NXT HOUR OR SO TO SEE IF SM OF THIS TRACE PCPN NEEDS TO BE ADDED TO FCST FOR THE ERY MRNG HRS. OTRW...TDAS MAIN FCST PROBLEM IS CLD TRENDS AND RESULTANT TEMPS. BACK EDGE OF POST-SYSTEM CLDS EXTENDING FROM KFOD-KMKC AT 09Z IS ONLY MAKING VRY SLOW EWD PROGRESS...SO HV PRETTY MUCH STAYED WITH GOING FCST TRENDS WHICH SUGGEST A SLOW W-E CLRG TREND DURG THE DAY. SINCE IT APRS THAT CLDS WL BE SMWHAT MORE PERSISTENT IN E AREAS HV TRIMMED BACK MAX TEMPS ALG AND SPLY E OF MSRVR. FOR THE RMNDR OF THE SHORT-TERM...FAIRLY TRANQUIL FEB WX SHUD BE THE RULE FOR THE REGION. AT THE SFC...CANADIAN HI THAT IS ENTERING THE REGION THIS MRNG WL BE THE DOMINATE FTR THRU MON...AS WK MID LVL RDG BUILDS INTO THE CNTRL U.S. MODELS ARE STILL FCSTG A FAST-MOVING SHTWV TO ZIP THRU AREA ON SUN...BUT WITH VRY LIMITED MSTR PCPN THRT APRS TO BE QUITE LOW AND HV KEPT FCST DRY. ONLY REALY CHG TO GOING TEMPS WAS TO TREND MAX TEMPS A BIT COOLER ON SUN...AS IT APRS THAT AMS WL BE A BIT COOLER THAN TDA AND THAT THERE SHUD BE A FAIR AMT OF MID AND UPR LVL CLDS ASSOC WITH SHTWV. BOTH 00Z GFS AND ECMWF CONT TO SUPPORT IDEA OF STG SFC LOW MOVING FROM KS TO N IL TUE NGT/WED. MUCH AS OCRD WITH LAST EVENINGS SYSTEM...WDSPRD PCPN AND ANY WINTER WX THRT WITH THIS SYSTEM WL BE N OF SFC LO...AND AS A RESULT N OF OUR CWA. IN OUR AREA...TREND OF LO CHC POPS AS MSTR INCRS IN WRM SECTOR STILL SEEMS REASONABLE AS BOTH MODELS ARE KICKING OUT A BIT OF QPF...ALTHO THIS IS HIER THAN POPS INDICATED BY 00Z MEX. TRUETT && .AVIATION... /1100 AM CST SAT FEB 14 2009/ FOR THE 18Z TAFS...SATELLITE SHOWS CLOUDS SLOWLY CLEARING FROM THE NORTH...SO EXPECT MVFR CLOUDS TO CLEAR AT THE TAF SITES BETWEEN 18-21Z WITH MVFR CLOUDS HANGING ON OVER SERN MO AND S CNTRL IL UNTIL LATE IN THE AFTERNOON. THEREAFTER...EXPECT CONTINUED DRY AND VFR CONDITIONS WITH CIGS OF BKN120 OR ABOVE TO MOVE INTO THE AREA AFTER 00Z. WINDS WILL STAY IN THE 340-040 RANGE THROUGH END OF PERIOD. BRITT && .LSX WATCHES/WARNINGS/ADVISORIES... MO...NONE. IL...NONE. && $$ WFO LSX ####018004413#### FXUS66 KLOX 141714 AFDLOX SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA 915 AM PST SAT FEB 14 2009 .SHORT TERM...(TODAY-MON) FORECAST ON TRACK TODAY FOR COOL AND RELATIVELY TRANQUIL DAY WITH SOME CLOUDS AND CENTRAL COAST SHOWERS. DID MAKE A FEW TWEAKS FOR TODAY HOWEVER...NAMELY LOWERED POPS TO 20S FOR SBA AND SLO CO AS SHOWERS SHOULD REMAIN QUITE ISOLATED...AND LOWERED TEMPS FOR THE LA/VTU VALLEYS. 12Z MODELS CAME IN AND PRELIMINARY GLANCE AT THE SUN/MON STORM LOOKS UNCHANGED IN TIMING FROM CURRENT FORECAST. ...FROM PREVIOUS DISCUSSION... THE POWERFUL STORM SYSTEM THAT THE MODELS HAVE BEEN ADVERTISING OVER THE PAST FEW DAYS IS STILL LOOKING QUITE POTENT...BUT THE TIMING HAS BEEN A BIT FRUSTRATING. HOWEVER...MOST MODELS ARE GOOD AGREEMENT THAT THE FRONT SHOULD BEGIN TO PUSH SOUTH TOWARDS SAN LUIS OBISPO BY SUNDAY AFTERNOON AND SLOWLY PROGRESS SOUTHEASTWARD TOWARDS SANTA BARBARA BY SUNDAY EVENING...THEN PUSH INTO VENTURA AND LOS ANGELES COUNTIES BY SUNDAY NIGHT. SOME PRE-FRONTAL SHOWERS MIGHT DEVELOP AHEAD OF THE FRONT EARLY IN THE AFTERNOON. A FAIRLY STRONG SURFACE LOW WILL DEVELOP OFF THE NRN CAL COAST...THIS WILL HELP STRENGTHEN THE SOUTHERLY WINDS ACROSS THE FORECAST AREA BY SUNDAY AND CONTINUE INTO PRESIDENTS DAY ON MONDAY. RAINFALL AND SNOW AMOUNTS CONTINUE TO LOOK QUITE IMPRESSIVE WITH THIS NEXT SYSTEM. AT THIS TIME INITIAL RAINFALL ESTIMATES CALL FOR 1 TO 3 INCHES ACROSS COAST AND VALLEY AREAS...WITH 2 TO 5 INCHES IN THE FOOTHILLS AND MOUNTAINS. LOCALLY HIGHER AMOUNTS ARE ALSO POSSIBLE ACROSS THE FAVORED SOUTHERN FACING SLOPES DUE TO STRONG SOUTHERLY FLOW. GIVEN THE RECENT RAINS AND SATURATED SOILS...A STORM SYSTEM OF THIS MAGNITUDE WOULD ALSO BRING A RISK OF FLASH FLOODING...EVEN TO NON BURN AREAS. IF RAINFALL ESTIMATES ARE CORRECT...A FLASH FLOOD WATCH WILL LIKELY HAVE TO BE ISSUED FOR AT LEAST THE BURN AREAS...AND POSSIBLY NON-BURN AREAS AS WELL. WITH SOME WARM ADVECTION EXPECTED AHEAD OF THE FRONT...SNOW LEVELS WILL BE A BIT HIGHER THAN RECENT WEATHER SYSTEMS...STARTING OUT AROUND 5000 TO 6000 FEET SUNDAY NIGHT THROUGH MONDAY...BUT SHOULD THEN LOWER TO NEAR 4000 FEET BY MONDAY EVENING. WITH THE STRONG WINDS AND ADDITIONAL SNOW ACCUMULATIONS POSSIBLY REACHING 2 TO 3 FT...A WINTER STORM WATCH FOR THE MOUNTAINS WILL LIKELY BE ISSUED LATER TODAY OR THIS EVENING. EXPECT DANGEROUS WINTER WEATHER CONDITIONS AT THE HIGHER MOUNTAIN ELEVATIONS THROUGH AT LEAST MONDAY. .LONG TERM...(TUE-FRI) THERE WILL CONTINUE TO BE A FEW MORE SHORTWAVES AROUND THE LOW MOVING ACROSS THE FORECAST AREA THROUGH TUE AS THE UPPER LOW OPENS UP AND FILLS IN. SNOW LEVELS SHOULD CONTINUE TO BE NEAR 4000 FT. BY TUE NIGHT...THE TROF WEAKENS AND PUSH EAST. MEANWHILE...BOTH GFS AND ECMWF INDICATE A MONSTER UPPER LOW BEGINNING TO PUSH SOUTH FROM THE GULF OF ALASKA OFF THE CALIF/ORE COAST BY WEDNESDAY. THE LAST FEW MODEL RUNS HAVE BEEN MORE CONSISTENT IN MOVING THIS IMPRESSIVE LOW AWAY FROM THE MAINLAND. WHAT WAS LOOKING A WET PATTERN INTO NEXT WEEK SHOULD REMAIN MOSTLY DRY UNTIL NEXT WEEKEND WHEN BOTH MODELS MOVE THE LOW ACROSS THE AREA. OF COURSE...ANY MINOR FLUCTUATIONS OF THIS LOW FARTHER EAST COULD BRING A MUCH WETTER PATTERN TO THE AREA. TEMPS WILL NOT VERY MUCH THROUGH THE PERIOD...CONTINUING TO BE SOMEWHAT COLDER THAN NORMAL FOR THIS TIME OF YEAR. && .AVIATION...14/1050Z OVERALL...EXPECT GENERAL VFR CONDS FOR ALL TAF SITES THROUGH THE NEXT 24 HOURS...EXCEPT FOR THE POTENTIAL FOR SOME MVFR CIGS THIS MORNING ACROSS THE LAX BASIN. IN ADDITION...THE FAST WEST TO NORTHWEST FLOW WILL LIKELY CONTINUE TO PRODUCE ISOLATED SHOWERS ESPECIALLY NORTH OF POINT CONCEPTION. SO...HAVE ADDED VCSH TO THE CENTRAL COAST TAFS THROUGH THIS AFTERNOON. KLAX...HIGH CONFIDENCE IN 12Z TAF. THERE IS A SLIGHT CHANCE MVFR CIGS THIS MORNING COULD BE MORE PERSISTENT THAN THE TEMPO GROUP INDICATES. KBUR...HIGH CONFIDENCE IN 12Z TAF. && .LOX WATCHES/WARNINGS/ADVISORIES... GALE WARNING (SEE LAXMWWLOX). GALE WATCH (SEE LAXMWWLOX). SMALL CRAFT ADVISORY (SEE LAXMWWLOX). SPECIAL WEATHER STATEMENT (SEE LAXSPSLOX). && $$ PUBLIC...KITTELL/KAPLAN AVIATION...THOMPSON WWW.WEATHER.GOV/LOSANGELES