929 
fxus65 kbyz 081752 
afdbyz 


Area forecast discussion...updated 
National Weather Service Billings Montana 
1052 am MST Thursday Jan 8 2009 


Short term...valid for today and Friday... 


Update to zone forecast product and wrkafp. Issued Ice Storm Warning for 
Custer...Fallon and NE Rosebud counties through 03z tonight. Slow 
moving warm front was bringing freezing rain with significant ice 
accumulations to areas around kmls creating major travel 
difficulties along Interstate 94 this morning. Spotters in Plevna 
and Angela also reported freezing rain and icy roads. Law 
enforcement estimated between a quarter and a half inch of ice on 
the Interstate near kmls. Despite kbhk reporting 35 degrees at 
17z...Montana dot reports Road temperatures near freezing...so would 
expect any rain to freeze on the roads in Fallon. Further 
south...precipitation was not as widespread. May have some 
freezing rain issues in northern Carter County so issued Freezing 
Rain Advisory there. Latest model data showed warm front lifting east 
of the area after 00z tonight which should end threat of freezing 
rain. 


Call to Stillwater mine...and observations at klvm and east klvm 
showed that advisory wind speeds continued in these locations. 
Have extended the Wind Advisory to 00z tonight...at which time the 
surface low should be pulling off to the east...ending the threat of 
strong winds. Next cold front on track to plunge S through the 
region tonight. Front will be accompanied by snow and areas of 
blowing snow. Will evaluate the need for any headlines for the 
afternoon package. Arthur 




Long term...valid for Sat...sun...Mon...Tue...Wed... 


Models still remain in good agreement through the extended in an 
active weather pattern and thus made just a few changes. 


Saturday into Saturday evening under a dry northwest flow aloft 
and continued some low probability of precipitation for the mountains. A shortwave will 
approach the area late Saturday night into Sunday with models in 
pretty good agreement in bringing a shot of precipitation to the 
area. Have bumped up probability of precipitation for these periods. Good baroclinic zone 
sets up Sunday night and into early next week with models showing 
another chance of precipitation for the area and continue the probability of precipitation 
going. Similar type of pattern remains in place through the 
middle of next week and kept some sort of precipitation mention at this 
time. 


Warm temperatures to remain in place through much of the extended across 
the western and central zones. The east will be dealing with shot 
of cold air on Monday as an Arctic cold surge moves through the 
upper Midwest. Wednesday is a bit interesting with the European model (ecmwf) 
bringing an Arctic blast to eastern Montana and the Midwest where 
the GFS keeps this surge much farther east. Went with a blend of 
the two models for temperatures on Wednesday and will have to be watched 
to see if any more definite trends emerge. 


Strong winds still look good for The Gap flow areas of Livingston 
and Nye for Saturday into Sunday and keep this trend going in the 
forecast. Solum 




&& 


Aviation... 


Scattered precipitation...including snow...rain snow mix...and 
freezing rain...will continue east of Billings this morning. The 
precipitation is expected to taper off from west to east this 
afternoon. Scattered snow is also expected to continue in the 
mountains through the day...resulting in obscuration through the 
day. MVFR to IFR conditions will prevail in and around areas of 
precipitation...with localized LIFR conditions in heavier precipitation. 


The foothills of the beartooth...absaroka and Crazy Mountains... 
including klvm today...will continue to see strong gusty 
winds...with gusts up to 60 knots possible through the day. 


A strong cold front will cross the region tonight...bringing more 
snow...and a windshift to the north. Gilstad 




&& 


Preliminary point temp/pops... 


Today Friday Sat sun Monday Tuesday Wednesday 
------------------------------------------------------- 
bil 051 027/037 018/040 027/044 024/038 020/041 021/030 
2/east 66/S 00/north 23/o 33/o 33/o 32/S 
lvm 052 022/035 018/038 025/040 026/039 019/045 021/036 
2/west 46/S 00/north 23/o 33/o 33/o 32/o 
hdn 050 025/033 014/039 022/045 021/037 016/036 015/028 
4/east 66/S 00/b 23/o 33/o 33/o 32/S 
mls 035 017/022 008/037 019/036 016/024 008/030 008/019 
+/y 56/S 00/b 23/S 33/S 33/S 32/S 
4bq 045 023/026 008/039 020/040 015/030 015/032 013/025 
+/west 45/S 00/b 23/o 33/S 32/S 22/S 
bhk 034 016/019 004/034 016/035 007/019 006/024 003/016 
+/y 57/S 00/b 23/S 33/S 33/S 32/S 
shr 048 026/032 009/040 020/042 020/035 015/038 015/032 
2/east 37/S 00/b 23/o 33/o 33/o 32/S 


&& 


Byz watches/warnings/advisories... 
Montana...Ice Storm Warning in effect until 8 PM MST this evening for 
zones 31>33. 
Freezing Rain Advisory in effect until 8 PM MST this evening 
for zone 37. 
Wind Advisory in effect until 6 PM MST this afternoon for 
zones 65-66. 
Wyoming...none. 


&& 


$$ 
Weather.Gov/Billings