MODIS AFD Archive Index
Last updated November 21, 2008
| Area Forecast Discussions mentioning MODIS issued by National Weather Service Forecast Office Billings, Montana (BYZ) |
000 FXUS65 KBYZ 032053 AFDBYZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 253 PM MDT SAT MAY 3 2008 .SHORT TERM...VALID FOR SUN AND MON... WEAK UPPER LEVEL HIGH PRESSURE RIDGE OVER WESTERN MONTANA WITH DRY NORTHWEST FLOW ALOFT SOUTHERN MONTANA. THIS COMBINATION WILL INHIBIT ANY PRECIPITATION AND HAVE REMOVED POPS OVER THE MOUNTAINS FOR TONIGHT. UPPER RIDGE IS PULLING WARMER AIR INTO THE REGION AND LOWS TONIGHT SHOULD BE 5 TO 10 DEGREES ABOVE LAST NIGHTS READINGS. HIGH PRESSURE RIDGE AXIS OVER THE ROCKIES SUNDAY WITH WEAK WESTERLY FLOW CONTINUING OVER THE FORECAST AREA. SHORT WAVE ENERGY MOVING ACROSS THE WESTERN ZONES SUNDAY WHICH WILL DEVELOP A FEW ISOLATED SHOWERS OVER THE MOUNTAINS. 700MB FLOW IS VERY WEAK AND ANY SHOWERS THAT DO DEVELOP WILL NOT MAKE IT FAR INTO THE PLAINS. TEMPERATURES CONTINUING TO WARM SUNDAY AND WILL SEE TEMPERATURES ABOVE SEASONAL VALUES FROM LIVINGSTON TO MILES CITY. TEMPERATURES WILL BE SLIGHTLY WARMER IN THE SOUTHEAST ZONES SUNDAY BUT CURRENT SNOW PACK WILL CONTINUE TO KEEP THEM BELOW NORMAL FOR THIS TIME OF THE YEAR. UPPER RIDGE OF HIGH PRESSURE FLATTENING OUT OVER MONTANA MONDAY AS STRONGER SHORT WAVE TO PASS OVER THE AREA. HAVE ADDED ISOLATED THUNDERSTORMS FOR MONDAY AFTERNOON OVER THE PLAINS AS MODELS INDICATING LOWS LEVELS TO DESTABILIZE WITH AFTERNOON HEATING. LI'S AROUND -2C OVER THE AREA WITH BUFKIT SHOWING WEAK ELEVATED CAPE. MOISTURE WILL BE LIMITED AND HAVE KEPT ONLY ISOLATED CHANCES FOR THE PLAINS AND MOUNTAINS. TEMPERATURES CONTINUING TO WARM ON MONDAY AS GOOD MIXING EXPECTED DURING THE AFTERNOON. TEMPERATURES WILL RANGE IN THE LOWER 70S FOR MOST LOCATIONS. THE RIVER GAGE ALONG THE LITTLE MISSOURI RIVER OVER CARTER COUNTY INDICATING RIVER LEVELS REMAINING WELL BELOW FLOOD STAGE. TEMPERATURES WILL ONCE AGAIN FALL BELOW FREEZING TONIGHT WHICH WILL SLOW DOWN SNOW MELT. MODIS VISIBLE SATELLITE SHOWING EXTENSIVE SNOW FIELD REMAINING ACROSS SOUTHEAST MONTANA AND THIS AREA WILL NEED TO BE MONITORED FOR POTENTIAL INCREASE IN SNOW MELT DUE TO WARMING TEMPERATURES SUNDAY AND MONDAY. RICHMOND .LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT... NW FLOW GIVES WAY TO WEAK UPPER RIDGING OVER AREA ON TUE. WILL HAVE UPPER LEVEL JET WITH RIGHT REAR QUADRANT CROSSING THE AREA PROVIDING SOME LIFT. GFS SOUNDINGS SHOWED SOME LOW TO MID LEVEL CAPE ACROSS THE REGION AND ENOUGH MOISTURE TO SUPPORT A SLIGHT CHANCE OF SHOWERS OVER THE AREA SO POPS WERE IN GOOD SHAPE. SHORTWAVE WILL APPROACH THE REGION AHEAD OF UPPER LOW OVER BC TUE NIGHT. MOISTURE WILL ADVECT INTO THE AREA ON SW FLOW AHEAD OF THE WAVE AND A COLD FRONT WILL PUSH E INTO THE AREA. HAVE RAISED POPS OVER WESTERN AND CENTRAL ZONES AHEAD OF THE WAVE. PREFRONTAL CONDITIONS SUPPORTED GOING WARMER TUE NIGHT SO HAVE USED THE BLENDED LONG TERM GUIDANCE TO RAISE TEMPERATURES. TEMPERATURES LOOKED REASONABLE FOR TUE. THERE WAS GOOD MODEL AGREEMENT THROUGH THU WITH UPPER LOW OVER BC MOVING SE TOWARD THE REGION. SOME DIFFERENCES IN PLACEMENT OF UPPER LOW BY FRI BUT GOOD AGREEMENT IN MAINTAINING AN UPPER LOW IN THE VICINITY OF THE FORECAST AREA. IN LOWER AND MID LEVELS...BOTH ECMWF/GFS HAD A 700 MB AND SURFACE LOW STACKED OVER OK/KS BY 00Z THU...FURTHER S THAN LAST BIG SYSTEM WITH AN INVERTED TROUGH NW INTO THE FORECAST AREA. THIS SOUTHERN SYSTEM WAS PROGGED TO PULL OFF TO THE E ON THU. ANOTHER SURFACE LOW WAS FORECAST TO FOLLOW ON ITS HEELS THU INTO FRI MAINLY JUST S OF THE REGION. BOTH ECMWF/GFS PAINTED QUITE A BIT OF QPF OVER THE AREA ON WED. THE GFS THEN SHOWED ANOTHER WET PERIOD FROM THU THROUGH FRI WHILE ECMWF WAS NOT AS WET. WITH POTENTIAL OF SEVERAL WET PERIODS...HAVE RAISED POPS WED THROUGH FRI. RAISED MINS THU NIGHT IN THE SE WITH THERMAL RIDGE IN THIS AREA AND USED THE MEX GUIDANCE. OTHERWISE...DIFFERENCES IN THERMAL FIELDS BETWEEN THE ECMWF AND GFS AS WELL AS SOME POSSIBLE PRECIP DAYS LENDED UNCERTAINTY TO MUCH OF TEMPERATURE FORECAST. ONLY OTHER CHANGES TO TEMPERATURES WERE FOR COORDINATION PURPOSES. MAJOR MODEL DIFFERENCES ON SAT WITH ECMWF BRINGING SW FLOW INTO AREA AHEAD OF A PACIFIC TROUGH AND GFS HAVING NW FLOW OVER THE AREA. MEANWHILE THE GFS ENSEMBLES MAINTAINED AN UPPER LOW OR TROUGH AND BEGAN SHIFTING IT E. WILL NEED TO WATCH MODEL TRENDS WITH TIME TO SEE HOW PATTERN EVOLVES FOR THIS PERIOD. ARTHUR && .AVIATION... VFR CONDITIONS WILL PREVAIL OVER THE AREA TONIGHT THROUGH SUNDAY MORNING. SOME MOISTURE WILL MOVE INTO THE WESTERN PORTION OF THE AREA SUNDAY AFTERNOON AND WILL SPREAD E DURING THE EVENING. ISOLATED SHOWERS...WITH SCATTERED MOUNTAIN RAIN AND SNOW SHOWERS... WILL SPREAD FROM W TO E ACROSS THE AREA THROUGH THE EVENING. VFR WILL PREVAIL BUT THERE WILL BE AREAS OF MOUNTAIN OBSCURATION. ARTHUR && .PRELIMINARY POINT TEMP/POPS... SUN MON TUE WED THU FRI SAT ----------------------------------------------------------- BIL 039/066 043/071 042/065 043/067 044/061 036/060 039/061 01/B 22/T 32/W 24/T 22/W 43/W 23/W LVM 032/061 036/066 036/061 038/063 037/057 032/056 034/057 13/W 22/W 32/W 43/T 23/W 43/W 23/W HDN 037/068 041/073 039/068 041/070 041/063 041/060 039/061 01/B 22/T 32/W 24/T 23/W 33/W 22/W MLS 037/066 042/072 041/065 041/068 044/061 038/059 039/060 00/B 12/T 21/B 23/T 32/W 33/W 22/W 4BQ 030/059 035/064 039/064 041/066 042/061 043/058 040/058 00/B 22/T 32/W 13/T 42/W 33/W 22/W BHK 036/065 036/065 038/063 039/065 042/060 040/055 040/056 00/B 12/T 32/W 23/T 32/W 33/W 32/W SHR 032/063 036/069 037/062 038/066 039/061 036/055 037/056 02/W 22/T 32/W 25/T 32/W 43/W 23/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS ---------------------------------------------------------------------- 000 FXUS65 KBYZ 101016 AFDBYZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BILLINGS MT 316 AM MST MON NOV 10 2008 .SHORT TERM...VALID FOR TDY AND TUE... UNSETTLED WEATHER PATTERN OVER THE AREA TODAY AND TUESDAY AS A WEAK UPPER FLOW PERSIST OVER THE FORECAST AREA. THIS PATTERN WILL CHANGE LATE TUESDAY NIGHT AS A STRONG ZONAL FLOW SETS UP. TODAY...BROAD UPPER TROUGH WILL BE OVER THE AREA TODAY. CLOSED UPPER LOW ASSOCIATED WITH THE TROUGH WAS LOCATED SOUTH OF THE FOUR CORNERS AREA THIS MORNING AND WILL BE EJECTING ENERGY NORTHWARD. SHORT WAVE ENERGY WAS LOCATED OVER EASTERN IDAHO AND NORTHWEST MONTANA THIS MORNING WITH PRECIPITATION DEVELOPING OVER THESE AREAS. PRECIPITATION WILL CONTINUE TO LIFT NORTHEAST THIS MORNING IN TO THE SOUTHERN ZONES AND HAVE MADE NO CHANGES TO THE LIKELY POPS ALREADY IN PLACE. MODIS SATELLITE IMAGERY SHOWING AREAS OF FOG ALONG THE EASTERN BORDER THIS MORNING WHICH WAS ADVECTING NORTHEASTWARD. TEMPERATURES OUT EAST THIS MORNING WERE IN THE TEENS AND WILL ADD AREAS OF FREEZING FOG THROUGH MID MORNING FOR FALLON AND CARTER COUNTIES. SCATTERED PRECIPITATION WILL BE SPREADING INTO THE PLAINS BY LATE MORNING. TEMPERATURES COOLER TODAY DUE TO CLOUD COVER AND MOISTURE ADVECTING INTO THE AREA. TONIGHT...UPPER TROUGH REMAINING OVER THE AREA WITH WEAK LIFT CONTINUING TO PUSH THROUGH. WILL KEEP A CHANCE OF ISOLATED SHOWERS GOING OVER THE PLAINS TONIGHT AS LOW LEVELS REMAINING VERY MOIST. BETTER CHANCE OF PRECIPITATION WILL BE OVER THE SOUTHWEST MOUNTAINS BUT NOT EXPECTING MUCH PRECIPITATION AS LIFT IS WEAK. TUESDAY AND TUESDAY NIGHT...WEATHER PATTERN CHANGING AS FLOW ALOFT BECOMING NORTHWEST WITH UPPER TROUGH EXITING TO THE EAST. DOWN SLOPE FLOW WILL DEVELOP OVER THE AREA TUESDAY WHICH WILL PERSIST THROUGH TUESDAY NIGHT FOR DRY WEATHER. SOME LIGHT SNOW SHOWERS ARE POSSIBLE OVER THE MOUNTAINS BUT THE PLAINS WILL BE DRY. 06Z MODEL RUN HAS BACKED OFF ON STRONG WINDS DEVELOPING IN THE GAP FLOW AREAS TUESDAY NIGHT AND IS NOW BRINGING THEM IN ON WEDNESDAY. WINDS SHOULD STILL BEGIN INCREASING TUESDAY NIGHT AS A LEE-SIDE TROUGH DEVELOPS BUT WILL REMAIN BELOW ADVISORY CRITERIA. BETTER MIXING WILL BE OVER THE AREA TUESDAY AND HAVE WARMED TEMPERATURES INTO THE LOWER 50S. RICHMOND .LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN... EXTENDED FORECAST UNDERWENT SOME EXTENSIVE BUT NOT OVERLY DRASTIC CHANGES THROUGHOUT...RESULTING FROM SLOWER PROGRESSION OF APPROACHING DISTURBANCE INTO THE AREA. BIGGEST STORY REMAINS THE HIGH WINDS CROSSING THE REGION EARLY IN THE EXTENDED. POPS LOOKED TO BE IN SOLID SHAPE THROUGHOUT THE EXTENDED...BUT DID BOOST POPS IN THE EAST FOR WEDNESDAY NIGHT AS WARM FRONT MOVES THROUGH THE AREA AND LOOKS LIKE SHOULD HAVE PRETTY GOOD POTENTIAL THERE. FEW OTHER MINOR CHANGES TO POPS THROUGH THE EXTEND WERE FOR COLLABORATIVE IN NATURE. HIGH PRESSURE BEGINS TO MOVE INTO THE AREA FRIDAY...WHICH SHOULD STAY ENTRENCHED ACROSS THE REGION THROUGH THE REMAINDER OF THE EXTENDED. THE MOST EXTENSIVE CHANGES CAME TO TEMPERATURES THROUGHOUT THE EXTENDED. BEGAN BY WARMING WEDNESDAY HIGH BY AROUND 5 DEGREES AS APPEARED TO AVERAGE AROUND 10 DEGREES BELOW OVERALL GUIDANCE BARRING A FEW OUTLIERS EITHER DIRECTION. IT APPEARS THIS IS A RESULT OF THE IMPROVED ORGANIZATION OF THE APPROACHING SYSTEM AND ASSOCIATED WARM FRONT. COOLED OFF THE REMAINDER OF THE EXTENDED...BASING CHANGE ON LIKELIHOOD OF UPPER LOW FUNNELING IN SOME COLD AIR EVEN THOUGH APPEARS TO KEEP ENERGY...AND TRENDING TOWARD GUIDANCE AS GOING FORECAST APPEARED ABOVE MOST GUIDANCE THROUGHOUT BULK OF THE EXTENDED. TEMPS DO HOWEVER APPEAR THAT THEY SHOULD STAY AROUND CLIMO RANGE OR HIGHER THROUGHOUT THE EXTENDED...WITH THE EXCEPTION OF FRIDAY FOLLOWING COLD FRONT PASSAGE. MADE SEVERAL ADJUSTMENTS TO WINDS THROUGHOUT THE PERIOD...LOWERED WINDS TO SUB-ADVISORY RANGE ON WEDNESDAY AFTERNOON BASED ON SLOWER ARRIVAL TIME OF SYSTEM. INCREASED WINDS ACROSS THE PLAINS THURSDAY THROUGH ABOUT SATURDAY MORNING...FOLLOWING PROGRESSION OF UPPER LEVEL LOW AND STRONG JET SWEEPING ACROSS THE AREA. THESE VELOCITIES AND TIMING OF THIS SYSTEM WILL NEED TO BE WATCHED CLOSELY BY LATER SHIFTS. GILSTAD && .AVIATION... VFR CONDITIONS WILL DOMINATE THE BULK OF THE REGION THROUGH THE DAY MONDAY. LOCALIZED AREAS FOG AND LOW STRATUS WILL CONTINUE IN IMPACT EXTREME EASTERN ZONES...IN AND AROUND KBHK...RESULTING IN LOCALIZED IFR TO LIFR CONDITIONS UNTIL SHORTLY AFTER SUNRISE. A WEAK DISTURBANCE IS EXPECTED TO BRING LIGHT RAIN AND SNOW SHOWERS TO THE WESTERN TWO THIRDS OF THE FORECAST AREA...MAINLY WEST OF A LINE THROUGH HYSHAM AND LAME DEER...ESPECIALLY IN THE HIGH TERRAIN. SHOWERS WILL CAUSE SOME LOCALIZED MVFR CONDITION IN ANY PRECIPITATION IN THE PLAINS...WHILE THE HIGH COUNTRY WILL BE OBSCURED MOST OF THE DAY IN CLOUDS AND SNOW SHOWERS. GILSTAD && .PRELIMINARY POINT TEMP/POPS... TDY TUE WED THU FRI SAT SUN ------------------------------------------------------- BIL 048 037/050 038/053 038/053 029/042 023/045 029/052 4/W 41/B 12/W 33/W 22/W 21/B 11/B LVM 048 032/048 037/049 041/052 029/043 027/047 031/052 6/W 32/W 33/W 43/W 22/W 22/W 22/W HDN 049 033/055 032/055 034/055 028/048 023/047 026/051 4/W 32/W 12/W 43/W 22/W 11/B 11/B MLS 043 030/050 032/052 034/051 024/043 021/043 026/046 2/W 22/W 12/W 52/W 21/N 11/B 11/B 4BQ 043 030/049 030/049 034/050 024/045 021/045 025/045 2/W 22/W 12/W 42/W 21/N 11/B 11/B BHK 036 025/044 028/046 031/043 022/038 020/041 021/039 2/W 22/W 12/W 42/W 11/N 11/N 11/B SHR 049 032/051 029/054 032/050 027/043 019/046 025/052 5/W 42/W 22/W 43/W 22/W 11/B 12/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS