FXUS65 KBOI 051011
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
311 AM MST SAT DEC 5 2009

.SHORT TERM...UPPER LOW WILL COME IN FROM THE NNE TODAY WITH EVEN 
COLDER AIR THAN WE HAD BEFORE...BUT CLOUDS AND WINDS WILL KEEP 
SURFACE TEMPS FROM DROPPING WAY DOWN FOR THE TIME BEING.  FLURRIES 
WERE OBSERVED DURING THE NIGHT AT MYL AND BNO...BUT MOISTURE CONTENT 
WITH THE INCOMING LOW IS SO LOW THAT NO MORE THAN AN INCH CAN BE 
EXPECTED TODAY EVEN IN BEST MOUNTAIN LOCATIONS...TRACES ELSEWHERE. 
THE LOW WILL ELONGATE EAST-WEST ACROSS OUR SRN ZONES THIS EVENING 
WHILE ANOTHER COLD UPPER LOW COMES SOUTH ALONG THE CASCADES.  THE 
TWO LOWS WILL TEND TO MERGE ACROSS SRN OREGON AND SRN IDAHO LATE 
TONIGHT AND SUNDAY WHICH WILL CONTINUE A SLIGHT CHANCE OF SNOW 
SHOWERS IN MOST ZONES THROUGH SUNDAY.  MEANWHILE...OUR NRN ZONES 
WILL BEGIN TO FEEL THE ARCTIC AIR SEEPING SOUTH SUNDAY ON NE WINDS.  
THE CORE OF ARCTIC AIR WILL BE WELL TO OUR NE BUT NE-SW SURFACE 
PRESSURE GRADIENT WILL INCREASE IN THE MAGIC VALLEY AND CAMAS 
PRAIRIE SUNDAY WITH INCREASING NE WINDS AND WIND CHILL.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...MODELS IN GOOD AGREEMENT 
SUNDAY NIGHT THROUGH TUESDAY WITH A LONG WAVE TROUGH OVER THE 
WESTERN SECTION OF THE COUNTRY WITH SLIGHT TIMING DIFFERENCES OF 
WEAK SHORT WAVES MOVING THROUGH THE FLOW.  THIS KEEPS THE FORECAST 
AREA UNDER A COLD AND MAINLY DRY NORTHERLY FLOW.  POPS FOR THIS TIME 
PERIOD BELOW CLIMATOLOGY DUE TO THE LACK OF MOISTURE AND DYNAMICS.  
TEMPERATURES FOR MONDAY AND TUESDAY WILL BE 10 TO 15 DEGREES BELOW 
NORMAL.  TUESDAY NIGHT THROUGH FRIDAY FLOW ALOFT SLOWLY SHIFTS TO 
THE NORTHWEST FOR MODERATING TEMPERATURES BUT WILL KEEP TEMPERATURES 
ON THE COLD SIDE DUE TO THE LOW LEVEL COLD AIR BEING HELD IN PLACE 
BY THE WARMING ALOFT AND THE LACK OF ANY MIXING.  STILL SOME 
UNCERTAINTY IN THE MODELS AS TO HOW FAR NORTH THE MOIST WESTERLY 
FLOW WILL GET.  AT THIS TIME THE MAIN BAND OF PRECIPITATION WILL 
REMAIN TO THE SOUTH OF THE FORECAST AREA BUT WITH UNCERTAINTY IN THE 
MODELS WILL KEEP THE POPS NEAR CLIMATOLOGY FOR THURSDAY AND FRIDAY.  
WILL KEEP THE TREND OF SLOWLY WARMING TEMPERATURES TO NEAR 
CLIMATOLOGY FOR THURSDAY AND FRIDAY.  

&&

.AVIATION...VFR CONDITIONS WITH MID LEVEL CEILINGS OVER THE REGION 
AND AREAS OF MOUNTAIN OBSCURATION.  WIDELY SCATTERED SNOW SHOWERS 
TODAY WITH LOCAL MVFR CONDITIONS AND ISOLATED IFR CONDITIONS.  
SURFACE WINDS WILL BE LIGHT FROM THE NORTHWEST WITH MODERATE TO 
STRONG NORTHWEST WINDS ALOFT.

TONIGHT AND SUNDAY ANOTHER WEAK WEATHER SYSTEM WILL MOVE SOUTH FROM 
CANADA FOR ANOTHER ROUND OF WIDELY SCATTERED SNOW SHOWERS.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.

&&

$$

WEATHER.GOV/BOISE

SHORT TERM...LC
LONG TERM....JA
AVIATION.....JA