####018003227#### FXUS64 KEWX 150526 AFDEWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX 1126 PM CST SAT FEB 14 2009 .AVIATION... MVFR STRATUS DECK ACROSS THE EASTERN PORTION OF THE REGION WILL CONTINUE TO SLOWLY LOWER OVERNIGHT. A RETURN TO VFR EXPECTED BY 17-19Z. KDRT WILL REMAIN VFR THROUGH THE TAF PERIOD. NRLY SFC WINDS AOB 10 KTS OVERNIGHT WILL INCREASE TO 10-15 KTS BY MID- MORNING. && .PREV DISCUSSION... /ISSUED 906 PM CST SAT FEB 14 2009/ UPDATE... UPDATED FORECAST TO DECREASE 1ST PERIOD POPS AND REMOVE THUNDER GIVEN LATEST RADAR TRENDS AND 00Z NAM12 DATA. ALSO INCREASED 1ST PERIOD MIN TEMPS ALONG AND EAST OF THE I-35 CORRIDOR BY 1-5 DEGREES GIVEN VERY LITTLE RADIATION COOLING WITH LOW CIGS FORECAST TO PERSIST OVERNIGHT. OTHERWISE...FORECAST ON TRACK. NEW SUITE OF PRODUCTS OUT SHORTLY. PREV DISCUSSION... /ISSUED 302 PM CST SAT FEB 14 2009/ DISCUSSION...CONTINUED CAA PATTERN TONIGHT WILL GRADUALLY DRY AND DECREASE CLOUDS OVER OUR NORTHERN AND WESTERN CWA THIS EVENING IN THIS SHALLOW COOL AIRMASS. SOME LIGHT RAIN OR SPRINKLES MAY YET OCCUR OVER THE EASTERN HALF OF THE CWA TONIGHT AS WEAK UPPER DISTURBANCES TRAVERSE AN AREA OF SHALLOW GULF OVERRUN. AS A POLAR JET DIVES SOUTHEAST INTO THE MISSISSIPPI VALLEY AREA TOMORROW.. SURGES OF COOL DRIER AIR WILL BUILD INTO THE REGION..WITH CONTINUED OVERRUNNING CLOUDINESS OVER SOUTHERN PORTIONS. BRIEF CLEARING TOMORROW EVENING AS DRY CAA CONTINUES..THEN INCREASING CLOUDINESS AFTER MIDNIGHT AS SHALLOW GULF MOISTURE AGAIN BEGINS TO OVERRUN. MOSTLY CLOUDY MONDAY WITH LIGHT RAIN OR SPRINKLES SOUTHERN AND WESTERN SECTIONS. INCREASING CHANCES FOR RAIN MONDAY NIGHT AS AN INCREASINGLY OVERRUNNING PATTERN SETS UP. AS A SHORT WAVE MOVES INTO THE SOUTHERN U.S. PLAINS TUESDAY..A DEEPENING SURFACE TROUGH WILL DEVELOP OVER THE SOUTHERN PLAINS INTO WEST TEXAS..THUS WARMING WILL BEGIN WITH SOUTHERLY FLOW ACROSS THE REGION. A PACIFIC FRONT WILL ARRIVE OVERNIGHT TUESDAY/EARLY WEDNESDAY WITH A FEW SHOWERS ALONG THE FRONT OVER EASTERN PORTIONS OF THE CWA. CLEARING AND MILD THURSDAY IN THE DRY PACIFIC AIRMASS. CONTINUED MOSTLY FAIR AND MILD FRIDAY UNDER A STABLE NORTHWEST FLOW ALOFT. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 46 64 46 60 49 / 30 - - 10 50 AUSTIN BERGSTROM INTL AIRPORT 49 65 43 60 47 / 30 - - 10 50 NEW BRAUNFELS MUNI AIRPORT 49 65 48 60 49 / 20 - - 10 50 BURNET MUNI AIRPORT 39 62 45 59 47 / 20 - - 20 40 DEL RIO INTL AIRPORT 46 73 52 59 51 / - - 10 20 20 GEORGETOWN MUNI AIRPORT 43 63 43 59 48 / 30 - - 20 40 HONDO MUNI AIRPORT 46 69 50 60 48 / 10 10 10 10 30 SAN MARCOS MUNI AIRPORT 49 66 46 60 50 / 30 - - 10 50 LA GRANGE - FAYETTE REGIONAL 51 67 46 60 52 / 40 10 - 10 40 SAN ANTONIO INTL AIRPORT 48 66 48 60 50 / 20 10 10 10 40 STINSON MUNI AIRPORT 49 68 49 60 49 / 20 10 10 20 40 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 11/25/JB ####018005048#### FXUS61 KALY 150526 AFDALY AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 1226 AM EST SUN FEB 15 2009 .SYNOPSIS... DRY WEATHER AND SEASONABLE TEMPERATURES WILL CONTINUE INTO EARLY NEXT WEEK AS HIGH PRESSURE DOMINATES. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... THE PRESSURE GRADIENT WEAKENS AS SURFACE HIGH BUILDS IN. ALOFT A SHORT WAVE MOVES THROUGH FAST FLOW. ANY LIGHT PRECIPITATION WILL REMAIN WELL TO OUR SOUTHWEST. HOWEVER SOME MID AND HIGH LEVEL CLOUDS WILL MOVE OVER MAINLY SOUTHERN PORTIONS OF THE FORECAST AREA. SEASONABLE TEMPERATURES. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/... DRY NORTHWEST FLOW WILL PERSIST ACROSS AREA INTO TUESDAY. SURFACE HIGH PRESSURE WILL BUILD IN. ALOFT...A SHORT WAVE WILL MOVE OUT THE PLAINS SUNDAY AND MOVE OFF THE SOUTHEAST COAST MONDAY. NO IMPACTS TO OUR AREA. IN ITS WAKE...RIDGING WILL BUILD IN ALOFT MAINTAINING OUR DRY NORTHWEST FLOW. ON TUESDAY...THE RIDGE ALOFT WILL BEGIN FLATTEN AS A NORTHERN STREAM TROUGH MOVES TOWARD THE REGION. AT THE SURFACE...THE HIGH WILL SHIFT EAST AND OFFSHORE RESULTING IN A SOUTHERLY FLOW DEVELOPING TUESDAY NIGHT. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... WENT WITH MOS GUIDANCE. LOW PRESSURE OVER ILLINOIS WEDNESDAY MORNING WILL BE CENTERED OVER EAST CENTRAL NEW YORK AND WESTERN NEW ENGLAND THURSDAY MORNING. GFS TEMP AT 925 MB AND 850 MB BRINGS THE ZERO DEGREE LINE UP TO AROUND THE CAPITAL REGION WED NIGHT...BUT BY 700 IT IS WELL BELOW FREEZING SOUTH TO NEW JERSEY...SO IT APPEARS A GOOD BET FOR A WINTRY MIX OF SNOW AND SLEET...WITH FREEZING RAIN SOMEWHAT LESS LIKELY ATTM FROM ABOUT THE CAPITAL REGION ON SOUTH AND EAST. IN THE ADIRONDACKS AND LAKE GEORGE REGION...IT LOOKS LIKE MAINLY SNOW. THE ECMWF HAS THE WARM LAYER FURTHER SOUTH...FOCUSED CLOSER TO THE SURFACE AND FOR A BRIEFER PERIOD...WHICH WOULD IMPLY ANY SIGNIFICANT SLEET BEING LIMITED TO THE SOUTHERN TIER OF OUR ZONES. FOR NOW...IT BEING STILL IN THE EXTENDED PERIOD...HAVE WORDED IT IN TERMS OF RAIN AND SNOW. IN EITHER CASE...THE PRECIP SHOULD END AS A PERIOD OF SNOW AS THE COLDER AIR WRAPS IN AT ALL LEVELS BEHIND THE DEPARTING SYSTEM ON THU. LAKE EFFECT SNOW SHOWERS WILL KICK IN ON THE ENSUING WESTERLY FLOW ACROSS PORTIONS OF THE WESTERN ADIRONDACKS...BUT AS THE AIR MASS DRIES FURTHER AT THE LOWER LEVELS...THIS SHOULD CURTAIL ON FRIDAY. BUT ANOTHER LOW EXPECTED TO DEVELOP OVER THE NORTH CENTRAL STATES IS PROGGED TO BE CENTERED OVER INDIANA SATURDAY MORNING... BRINGING THE NEXT GOOD CHANCE FOR PRECIP. MODELS RIGHT NOW HINT AT ALL SNOW...WITH SEVERAL INCHES POSSIBLE. TEMPS BEHIND THE FIRST SYSTEM DO NOT LOOK TO BE AS COLD AS WITH YESTERDAY'S RUNS...WITH HIGHS AVERAGING SLIGHTLY ABOVE NORMAL THROUGH THURSDAY...AND RIGHT AROUND NORMAL THEREAFTER. WEDNESDAY NIGHT WILL BE THE MILDEST OF THE PERIOD...AS LOWS SOUTH OF THE ADIRONDACKS WILL BE MAINLY IN THE UPPER 20S AND LOWER 30S...THIS DUE TO THE SOUTHERLY WIND GRADIENT THAT DEVELOPS AHEAD OF WEDNESDAY'S SYSTEM. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... VFR CONDITIONS EXPECTED TO CONTINUE THROUGH 06Z MON WITH SOME BKN HIGH LEVEL CLOUDS THOUGH EARLY THIS MORNING WHICH WILL DIMINISH BY AFTERNOON WITH SKC CONDITIONS EXPECTED TONIGHT. NW WINDS WILL GENERALLY BE 5-12 KTS THROUGH EARLY THIS EVENING THEN BECOME LIGHT AND VARIABLE OR CALM AFTER 03Z. OUTLOOK... SUN NIGHT-TUE NIGHT...VFR. NO SIG WX. WED-THU...VFR/MVFR. CHC -SN/-PL/-RA. && .HYDROLOGY... LITTLE ICE MOVEMENT IS EXPECTED OVER THE NEXT SEVERAL DAYS AS ANY JAMS FREEZE IN PLACE UNTIL THE NEXT SIGNIFICANT THAW. A COUPLE OF SPOTTERS HAVE CALLED IN TODAY CONFIRMING THIS. LOOKING AT DRY WEATHER INTO EARLY THIS COMING WEEK WITH SEASONABLE TEMPERATURES. HIGHS WILL START TO POKE A FEW DEGREES ABOVE FREEZING BUT NIGHTTIME LOWS WILL REMAIN WELL BELOW...SO FLOWS WILL CONTINUE TO DIMINISH. ICE IN MANY AREAS WILL THICKEN RATHER QUICKLY AS THE INSULATING LAYER OF SNOW ON TOP IS MOSTLY GONE. A STORM WHICH IS FORECAST TO MOVE OUT OF THE PLAINS TUESDAY NIGHT INTO THE MISSISSIPPI VALLEY WEDNESDAY LOOKS TO BE TAKING A MORE NORTHWESTERLY COURSE. IT WILL NEED TO BE MONITORED AS A TRACK UP THE SAINT LAWRENCE VALLEY OFTEN BRINGS WARM AIR IN AHEAD OF IT WHICH COULD RESULT IN ANOTHER ROUND OF MELTING AND RAIN WEDNESDAY INTO THURSDAY...WHICH COULD BOOST RIVER FLOWS AND CAUSE ICE MOVEMENT. FOR DETAILS ON PAST REPORTED ICE JAM LOCATIONS PLEASE SEE OUR ICE JAM REFERENCE ONLINE AT WWW.WEATHER.GOV/ALBANY. FOR DETAILS ON THE RIVERS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...IAA NEAR TERM...IAA SHORT TERM...IAA LONG TERM...HELLER AVIATION...11 HYDROLOGY...RCK ####018004708#### FXUS63 KTOP 150528 AFDTOP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TOPEKA KS 1128 PM CST SAT FEB 14 2009 .UPDATE... UPDATED FOR 06Z TAFS. && .DISCUSSION... SEE PREVIOUS DISCUSSION. && .AVIATION... VFR CONDITIONS EXPECTED THROUGH THE PERIOD. MID LEVEL CLOUD DECK NEAR 10KFT EXPECTED TO CONTINUE OVERNIGHT AND MOVE EASTWARD LATE SUNDAY MORNING. WINDS REMAIN NORTHEASTERLY. 67 && .PREV DISCUSSION... /ISSUED 340 PM CST SAT FEB 14 2009/ DISCUSSION... THE 19Z WATER VAPOR SATELLITE IMAGE SHOWED A WEAK UPPER LEVEL TROUGH MOVING EAST ACROSS THE GREAT BASIN. A MORE AMPLIFIED UPPER LEVEL TROUGH WAS MOVING EAST ACROSS CENTRAL CANADA...EXTENDING SOUTHWARD ACROSS THE GREAT LAKES STATES. A STRONG SUBTROPICAL JET STREAM WAS MOVING ACROSS NORTHERN MEXICO...EAST NORTHEAST ACROSS THE SOUTHERN US. AN INTENSE UPPER LEVEL TROUGH WAS DIGGING SOUTHWARD ACROSS THE EAST CENTRAL PACIFIC. THE 19Z VISIBLE SATELLITE IMAGE SHOWED SNOW COVER ACROSS THE EXTREME NORTHERN CWA ALONG THE NE BORDER...THEN NORTHWARD ACROSS MUCH OF SOUTHERN AND CENTRAL NE. NORTHEAST WINDS ACROSS THE SNOW COVER WAS WAS KEEPING CNK COOLER WITH 28 DEGREES. FALL CITY...NE JUST NORTH OF BROWN COUNTY WAS ONLY 23 DEGREES. THE REMAINDER OF THE CWA HAD TEMPERATURES IN THE MID 30S. TONIGHT AND SUNDAY...A MINOR 5H TROUGH OVER THE GREAT BASIN WILL MOVE EAST ACROSS THE CENTRAL PLAINS TONIGHT AND THEN DIG SOUTHEAST INTO THE MID MS RIVER VALLEY ON SUNDAY. INCREASING WAA AT THE 700MB LEVEL AHEAD OF THE 5H TROUGH WILL CAUSE MID LEVEL CLOUDS TO INCREASE TONIGHT AND LAST THROUGH SUNDAY MORNING. ONCE THE 5H TROUGH AXIS MOVES EAST OF THE PLAINS SUNDAY AFTERNOON...SKIES SHOULD CLEAR. A SURFACE RIDGE WILL CONTINUE ACROSS THE EASTERN PLAINS AND MIDWEST THROUGH THE PERIOD. OVERNIGHT LOWS WILL BE A BIT WARMER TONIGHT WITH THE MID LEVEL CLOUDS. TOMORROW HIGHS WILL REACH THE MID 30S ALONG THE NE BORDER WITH HIGHS AROUND 40 DEGREES ACROSS THE REMAINDER OF THE CWA. GARGAN SUNDAY NIGHT THROUGH MONDAY NIGHT...SFC RIDGE WILL BEGIN TO RETREAT TO THE EAST THROUGH THE NIGHT...BUT LIGHT WINDS...LACK OF CLOUDS...DRY AIR AND COOL START TO THE EVENING WARRANTS LEANING TOWARDS THE COOLER SIDE FOR LOWS AS OVERNIGHT WAA MAY NOT OCCUR QUICK ENOUGH OR BE VIGOROUS ENOUGH TO OVERCOME LOW LEVEL INVERSION THAT QUICKLY SETS UP IN THE EVENING AS EVIDENCED EVEN OVER THE NORTH CENTRAL AREAS. WILL GO WITH UPPER TEENS NORTH TO LOWER 20S SOUTH. WAA...WINDS AND CLOUDS WILL ALL BE ON THE INCREASE THROUGH THE DAY MONDAY ACROSS THE CWA AS LEESIDE CYCLOGENESIS DEVELOPS IN RESPONSE TO SHORTWAVE ADVANCING NORTHEAST ACROSS CA INTO THE INTERMOUNTAIN WEST. DESPITE THE INCREASE IN CLOUDS...SHOULD SEE HIGHS RISE INTO THE LOWER 40S FAR NORTH TO UPPER 40S EAST CENTRAL. THE STRONG WAA IN THE 750-850MB LAYER WILL ALSO LEAD TO A STRENGTHENING ELEVATED MIXED LAYER ACROSS THE CWA IN THE PRESENCE OF A FAIRLY DRY ATMOSPHERE. WILL KEEP FCST DRY THROUGH MONDAY NIGHT. ON TUESDAY...SFC LOW WILL BEGIN TO EDGE EASTWARD INTO CENTRAL KS BY LATE AFTERNOON. STRATUS/STRATOCU DECK WILL LIKELY DEVELOP BENEATH THE EML MONDAY NIGHT INTO TUESDAY. AS SHORTWAVE ADVANCES INTO THE PLAINS...LARGE SCALE LIFT WILL DEVELOP BY MIDDAY...BUT OCCURS WELL ABOVE THE EML AND IN A DRY ENVIRONMENT. ALTHOUGH CANNOT TOTALLY RULE OUT SOME LIGHT RAIN/DRIZZLE WITHIN THE LOWER CLOUD DECK...POPS LOOK LOW AND HAVE OPTED TO KEEP FCST DRY THROUGH THE DAY AND WAIT UNTIL COOLING ALOFT TAKES PLACE IN THE EVENING AND OVERNIGHT AS TROUGH MOVES THROUGH AND COLDER AIR BEHIND EXITING SFC LOW PLUNGES SOUTHWARD ACROSS THE CWA. AT THAT TIME...ANY LIGHT RAIN OCCURING ACROSS THE NORTHERN CWA LATER IN THE NIGHT MAY MIX WITH OR CHANGE TO SNOW OVER THE NORTHERN CWA...ENDING OVER THE FAR NORTHEAST WEDNESDAY AS THE TROUGH EXITS TO THE SOUTHEAST. HAVE RAISED HIGHS TUESDAY UPWARDS SLIGHTLY AND OVER THE SOUTHEAST CWA TUESDAY NIGHT WITH THE LATER ARRIVAL OF THE COLD AIR. EITHER WAY...WEDNESDAY IS LOOKING LIKE AND A COLDER AND BLUSTERY DAY ACROSS THE AREA WITH THE CENTER OF THE SFC HIGH AND LIGHTER WINDS ON THURSDAY. HIGHS BOTH DAYS SHOULD BE IN THE MID 30S NORTH TO LOWER 40S SOUTH. A REINFORCING PUSH OF COLDER AIR MAY ARRIVE ON FRIDAY FOR THE WEEKEND...BUT WITH CONFIDENCE ON TIMING AND STRENGTH THIS SCENARIO LOW THIS FAR OUT...WILL KEEP HIGHS IN THE 40S FOR NOW. EITHER WAY...A DRY FCST BEYOND WEDNESDAY SHOULD BE THE RULE IN NORTHWEST FLOW PATTERN. 63 && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ####018006641#### FXUS61 KRNK 150529 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 1229 AM EST SUN FEB 15 2009 .SYNOPSIS... LOW PRESSURE OVER SOUTHERN VIRGINIA WILL CONTINUE TO MOVE EAST AND OFFSHORE TONIGHT. ANOTHER LOW WILL PASS WELL SOUTH OF THE MID ATLANTIC REGION SUNDAY NIGHT AND MONDAY BEFORE DEEPENING OFF THE COAST. HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE NORTH AND WEST ON MONDAY...BRINGING CLEARING SKIES AND COLDER WEATHER. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AT 02Z THE SURFACE LOW WAS CENTERED CLOSE TO DAN. ALL OF THE LIGHT RAIN JUST AHEAD OF THE LOW HAS DISSIPATED. THE LOW WILL CONTINUE TO MOVE EAST OVERNIGHT. 00Z SOUNDINGS SHOWED A LAYER OF LOW LEVEL MOISTURE THAT WAS NOT VERY THICK. HAVE ADDED PATCHY FREEZING DRIZZLE IN FOR THE FAR NORTHWEST COUNTIES SINCE ANY CRYSTAL GROWTH LOOKS UNLIKELY. && .SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/... SUNDAY SHOULD BE A BENIGN WEATHER DAY WITH LOW CLOUDS ERODING IN THE MOUNTAINS...FOLLOWED BY INCREASING UPPER LEVEL MOISTURE AHEAD OF THE NEXT FAST MOVING DISTURBANCES ALOFT. PER COLD AIR ADVECTION...SUNDAYS TMAX MAINLY IN THE 40S...LOWER 50S SOUTHSIDE VA AND INTO THE PIEDMONT OF NC. A WEAK UPPER DISTURBANCE WILL SLIDE ACROSS THE REGION MONDAY NIGHT. THERE IS SOME VERTICAL MOTION FROM ISENTROPIC LIFT OVERNIGHT TO HELP SATURATE THE ATMOSPHERE...BUT PRECIPITATION CHANCES WILL BE LIMITED TO THE VA-NC BORDER. THE NAM IS SHOWING A HALF TO ONE INCH OF LIQUID PRECIPITATION TO THE NW NC MOUNTAINS WHILE GFS IS ABOUT A TENTH OF AN INCH. WITH CONVECTION ALONG THE COAST...CSTAR ACTION MAKING GFS THE MODEL OF CHOICE FOR THIS TIME PERIOD. BOTH MODELS DISPLAYING SE COASTAL LOW DEVELOPMENT EARLY MONDAY MORNING TO FURTHER ROB THE AREA OF ANY MOISTURE AND PRECIPITATION. THERMAL PROFILES SHOWING COLD AIR WORKING IN ALOFT AND EVAPORATIVE COOLING TO HAVE MOST OF THE PRECIPITATION FALLING AS A WET SNOW. NAM BUFKIT OUTPUT FOR SNOWFALL AT BOONE (TNB) IS ABOUT 6 INCHES...GFS ONLY A HALF OF AN INCH. WITH SUNDAYS TEMPERATURES REMAIN MILD AND INCREASE SUN ANGLE...WARM ROAD SURFACES SHOULD BE ABLE TO MELT MOST OF THE SNOW THAT FALLS. OUTSIDE OF SHELTER AREAS AND HIGHER ELEVATIONS...SNOW ACCUMULATIONS WILL BE CONFIDED TO GRASSY SURFACES. WITH CONVECTION TO THE SOUTH...WILL KEEP ACCUMULATION LIGHT...EVEN ACROSS THE HIGHER ELEVATIONS. MONDAY MORNING...THE SOUTHEAST COASTAL WILL BE PULLING SNOW AND MOISTURE OUT OF THE AREA. AS THE UPPER LEVEL TROUGH AXIS PIVOTS TO THE EAST COAST...THEIR MAY BE A BRIEF PERIOD OF UPSLOPE SNOW SHOWERS IN THE WEST. WITH HIGH PRESSURE BLOCKING THE GREAT LAKES AND FLOW BEING MORE NORTHERLY...RESIDUAL LOW LEVEL MOISTURE MAY MUSTER A LIGHT COATING OF SNOW ON THESE WESTERN SLOPES. BY THE AFTERNOON...HIGH PRESSURE MOVES INTO THE OHIO VALLEY AND DRIER AIR WILL END SNOW THREAT. HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TUESDAY AND SLIDE OFF THE COAST TUESDAY NIGHT. WARM MOIST AIR WILL INVADE THE REGION TUESDAY NIGHT TO HELP SATURATE THE ATMOSPHERE. JET DYNAMIC INCREASING THROUGH THE OVERNIGHT HOURS AS A 50-60 KT LOW LEVEL JET TRACKS ACROSS THE TENNESSEE VALLEY. THIS SYSTEM IS MOVING VERY QUICKLY INTO A DRY AIR MASS AND PRECIP MAY HOLD OFF UNTIL WEDNESDAY. HOWEVER...WILL HAVE CHANCE POPS IN THE WEST AFTER MIDNIGHT TO ACCOUNT FOR TIMING ISSUES. TEMPERATURES PROFILE SUGGEST TUESDAY NIGHTS PRECIPITATION WILL BE RAIN...HOWEVER...EVAPORATIVE COOLING COULD PRODUCE POCKETS OF FREEZING RAIN IN DEEPER MOUNTAIN VALLEYS. CONFIDENCE NOT HIGH ENOUGH TO ADD FREEZING RAIN TO FORECAST. TEMPERATURES WILL DROP TO NORMAL LEVELS SUNDAY NIGHT...THEN BELOW NORMAL MONDAY AND TUESDAY. MONDAY SHOULD BE THE COLDEST DAY OF THE PERIOD AS COLD HIGH PRESSURE TRACKS OVER THE REGION. TEMPERATURES MONDAY AND MONDAY NIGHT WILL BE AROUND 5-10F BELOW NORMAL. TEMPERATURES MODERATE SOME ON TUESDAY BUT WILL BE A FEW DEGREES SHY OF NORMAL. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... MORE CONSISTENCY IN THE LONG RANGE SUITE REGARDING THE WEDNESDAY/THURSDAY SYSTEM. THUS...INC POPS TO LOW LIKELY AND MADE SOME CHGS TO TEMPS. CONSIDERING THE CONSISTENT LONG RANGE MODEL BIAS OF ACCELERATING COLD FRONTS TOO QUICKLY EAST...SLOWED DOWN THE PROGRESSION OF COLDER AIR GIVING WARMER MINS WED NIGHT AND WARMER MAX T IN THE DOWNSLOPE REGION ON THURSDAY. ENOUGH COLD AIR AND PERSISTENT NW WINDS...AS THE UPPER PATTERN CONNECTS VERY WELL WITH THIS TYPE OF OUTCOME...SHOULD LEAD TO ACCUM UPSLOPE SNOWS ACROSS SE WEST VA AND NW NC STARTING THURS NIGHT AND LASTING INTO PART OF FRIDAY. ECMWF TODAY IN ADDITION TO THE GFS IS PUSHING THE EASTERN TROUGH OFF THE COAST RATHER QUICKLY...AND NOT SURE IF I BUY THIS RAPID DEPARTURE. ESPECIALLY THE ECMWF IS SHOWING A JET STREAK ENTERING THE WEST COAST WHICH SHOVES THE UPPER RIDGE IN THE CENTRAL CONUS EAST. PERHAPS WITH BETTER UPPER AIR DATA AS NEXT WEEK APPROACHES...THIS CONUNDRUM WILL BE BETTER RESOLVED. FOR NOW...KEPT TEMPS A LITTLE COLDER LONGER THAN GUIDANCE SUGGESTS ON SATURDAY. ALSO...CONSIDERING THE ABOVE...THE SYSTEM WHICH BOTH THE ECMWF/GFS DEPICT NEXT WEEKEND WOULD TAKE A MORE SOUTHERLY TRACK IF THE EASTERN TROUGH IS STILL IN PLACE. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... CHECK SIGMETS/AIRMETS FOR ICING...TURBULENCE AND MOUNTAIN OBSCURATIONS. IN THE WEST...NORTHWEST FLOW WILL CONTINUE UPSLOPE LOW CLOUDS WITH LIGHT SNOW SHOWERS AND MVFR CEILINGS AT BLF AND LWB EARLY THIS MORNING. EAST OF THE MOUNTAINS CONDITIONS WILL LIKELY REMAIN VFR. MOUNTAIN CLOUDINESS SHOULD DISSIPATE LATER THIS MORNING...BUT ANOTHER LOW PRESSURE SYSTEM MAY BRING MORE LIGHT PRECIPITATION TO THE AREA TONIGHT AND MONDAY...AGAIN WITH THE THREAT OF MVFR CIGS AND VSBYS...ESPECIALLY ACROSS NORTHWEST NORTH CAROLINA. VFR CONDITIONS ARE EXPECTED TUESDAY FOLLOWED BY INCREASING CLOUD COVER AGAIN AHEAD OF ANOTHER MORE ORGANIZED LOW PRESSURE SYSTEM FOR MIDWEEK. && .EQUIPMENT... THE HINTON WV NOAA WEATHER RADIO IS WORKING IN A DEGRADED MODE... 300 WATTS AS OPPOSED TO 1000 WATTS. THE COMMERCIAL POWER IS OUT DUE TO THE WIND DAMAGE IN THE AREA AND IT MAY TAKE ANOTHER DAY OR TWO TO RESTORE. IN THE MEAN TIME WE ARE RUNNING OFF OF A GENERATOR...BUT AT A REDUCED POWER. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...AMS NEAR TERM...AMS SHORT TERM...RCS LONG TERM...KM AVIATION...KK/PM EQUIPMENT... ####018004510#### FXUS65 KTFX 150529 AFDTFX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 1030 PM MST SAT FEB 14 2009 ...UPDATE TO AVIATION... .DISCUSSION... TONIGHT THROUGH MONDAY...LIGHT SNOW THAT FELL ACROSS PARTS OF NORTH-CENTRAL MONTANA SATURDAY MORNING HAS TAPERED TO FLURRIES THIS EVENING. WHILE NO SIGNIFICANT STORM SYSTEMS ARE EXPECTED DURING THIS PERIOD...WE WILL CONTINUE TO STAY IN AN UNSETTLED PATTERN WITH SEVERAL WEAK DISTURBANCES PASSING OVER THE REGION. ONE OF THESE WEAK SHORTWAVES WILL MOVE ACROSS SOUTHWEST MONTANA THIS EVENING AND TONIGHT GENERATING LIGHT SNOW...ESPECIALLY IN THE MOUNTAINS WHERE ONE TO THREE INCHES OF SNOW ARE POSSIBLE. ON SUNDAY...WE WILL BE IN-BETWEEN SYSTEMS WITH DRY BUT COOL CONDITIONS EXPECTED AS HIGH PRESSURE OVER SOUTHERN CANADA ALLOWS COOLER AIR TO STAY SETTLED OVER THE REGION THROUGH SUNDAY. ANOTHER STRONG PACIFIC STORM SYSTEM MOVES INTO THE WEST COAST ON MONDAY WHILE A WEAK FRONTAL BOUNDARY SLIDES SOUTH FROM SOUTHERN CANADA. MEDIUM RANGE MODELS ARE INDICATING THAT PACIFIC MOISTURE WILL INTERACT WITH THE DESCENDING BOUNDARY GENERATING PRECIPITATION ACROSS NORTHERN MONTANA. WHILE THE MAJORITY OF THE MOISTURE WILL STAY WEST OF THE CONTINENTAL DIVIDE...ENOUGH MOISTURE SHOULD CROSS OVER INTO NORTH-CENTRAL MONTANA SO INCREASED POPS INTO LIKELY CATEGORY ACROSS FAR NORTHERN MONTANA STARTING SUNDAY NIGHT AND AGAIN MONDAY. WHILE IT IS STILL UNCERTAIN AS TO SNOW AMOUNTS SINCE IT DEPENDS ON HOW MUCH MOISTURE INTERACTS WITH THE FRONT...THERE IS THE POTENTIAL FOR SEVERAL INCHES IN THE NORTHERN ROCKIES WITH LESSER AMOUNTS ALONG THE NORTHERN ROCKY MOUNTAIN FRONT BUT THIS TREND WILL CONTINUE TO BE MONITORED. SOUTH OF THE BOUNDARY...SOUTHWEST FLOW ALOFT AND AT THE SURFACE WILL ALLOW FOR SEASONAL TEMPERATURES DURING THE DAY ON MONDAY. MLS MONDAY NIGHT THROUGH THURSDAY NIGHT...OVER THE PLAINS AND THE ADJOINING MOUNTAINS..A WEATHER DISTURBANCE FROM CANADA IS FORECAST TO MOVE SOUTH OVER THE AREA TUESDAY NIGHT INTO EARLY WEDNESDAY. IT WILL BE PRECEDED BY ANOTHER SHOT OF CANADIAN AIR. SINCE THE AIRMASS AHEAD OF IT IS ALREADY ON THE COLD SIDE DO NOT EXPECT TO SEE A SIGNIFICANT DROP IN TEMPERATURES. OVER SOUTHWEST MONTANA THE REMNANTS OF A PACIFIC UPPER LOW WILL MOVE ACROSS THE AREA ON TUESDAY AND WILL KEEP A CHANCE OF SNOW FOR THE VALLEYS WITH SNOW MORE LIKELY OVER THE MOUNTAINS. MOISTURE WILL LINGER INTO WEDNESDAY. FOR THE ENTIRE AREA WEDNESDAY NIGHT INTO THURSDAY EXPECT A BREAK IN THE MOISTURE BUT THERE WILL CONTINUE TO BE A SMALL THREAT FOR SNOW OVER THE MOUNTAINS. MODELS DIFFER ON THEIR SOLUTIONS BY THE END OF THE PERIOD. THE ECMWF BRINGS A WEATHER DISTURBANCE AND MOISTURE THROUGH THE AREA THURSDAY NIGHT WHILE THE GFS IS WEAKER AND FARTHER EAST. IN CASE THE ECMWF PANS OUT HAVE ADDED A MENTION OF SNOW TO THE EAST SLOPES OF THE ROCKY MOUNTAINS FOR THURSDAY NIGHT. BLANK FRIDAY AND SATURDAY...A HIGH PRESSURE RIDGE IS EXPECTED TO BUILD IN FROM THE WEST KEEPING PRECIPITATION CHANCES LOW DURING THIS PERIOD. ABOVE AVERAGE TEMPERATURES WILL COVER MUCH OF THE CENTRAL PLAINS. BY LATE IN THE WEEKEND ANOTHER PACIFIC LOW PRESSURE SYSTEM IS EXPECTED TO MOVE INTO THE PACIFIC NORTHWEST. SAUCIER && .AVIATION... WEAK WESTERLY FLOW ALOFT WILL CONTINUE ACROSS MONTANA THROUGH SUNDAY AFTERNOON. AT THE SURFACE...HIGH PRESSURE OVER EASTERN MONTANA CONTINUES TO MOVE SLOWLY EAST...WITH GENERALLY LIGHT EAST TO NORTHEAST WINDS ACROSS NORTH CENTRAL MONTANA. THIS SCENARIO WILL KEEP VARIABLE LOW AND MID-LEVEL UPSLOPE CLOUDS IN PLACE FOR AREAS OF LIGHT SNOW AND FOG WITH CEILINGS AND VISIBILITY VARYING BETWEEN VFR AND IFR AT TIMES. FORECAST MODELS INDICATE SLOW IMPROVEMENT IN CONDITIONS STARTING MID MORNING SUNDAY AS THE WESTERLY FLOW ALOFT BRINGS SLIGHTLY DRIER CONDITIONS...AND A WEAK SURFACE TROUGH DEVELOPS IN NORTH CENTRAL MONTANA FOR SOUTHERLY SURFACE WINDS. MPJ && .PRELIMINARY POINT TEMPS/POPS... GTF 12 28 15 32 / 40 20 50 20 CTB 9 20 13 26 / 50 30 60 30 HLN 18 36 22 41 / 40 20 20 10 BZN 16 35 20 40 / 40 10 10 10 WEY 2 25 9 30 / 60 30 30 30 DLN 13 31 19 38 / 50 10 10 20 HVR 1 20 4 21 / 20 20 40 20 LWT 10 26 16 30 / 40 20 20 20 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ WEATHER.GOV/GREATFALLS