409 
fxus65 kbyz 300905 
afdbyz 


Area forecast discussion 
National Weather Service Billings Montana 
305 am MDT Sat Aug 30 2008 


Short term...valid for today and sun... 


Forecast still on track for the most part with only a few changes 
made. 


Very hot and dry day in store for the region today. Deep 
southwest flow over the area will provide a good day of mixing 
allowing winds to increase across much of the area. Good 
prefrontal warming and mixing will allow temperatures to climb 
into the 90s to around 100 degrees. Relative humidities will also 
be very low today in the single digits and teens. Portions of 
fire zone 123 already hitting red flag criteria so will push up 
the start time for zones 123 through 126 to now and will leave 
the rest of the zones to start at noon. Fire zones 131 and 132 
will be borderline on red flag criteria with the winds. Will hold 
off on adding these zones and let day shift take one last look on 
the update this morning. 


Cold front associated with the approaching upper low will slide 
through the region tonight. Still looks fairly dry as the front 
moves through but did leave slight chance probability of precipitation behind the front 
as there is enough energy where some thunderstorms may form. 
Front slow to move into southeast Montana on Sunday and have kept 
high temperatures there close to 90 degrees. The central and western 
zones will see highs in the 60s and 70s for Sunday. Sunday still 
a transition type of day. 


As low digs on Sunday and Sunday night...a strong piece of energy 
lifts out ahead of it into Sunday night across the central and 
western zones. This looks like the start of the good precipitation for 
the area. Have continued the trend of bumping up probability of precipitation for this 
period. Some places could see localized precipitation amounts on Sunday 
night of a half inch to an inch. The mountains will not see too 
much accumulation on Sunday night as the real strong cold push is 
just starting to make its way into the area by then. Solum 




Long term...valid for Monday...Tue...Wed...Thu...Fri... 


Models still on track in bringing upper trough the region Monday 
through Tuesday. Models still showing some discrepancies on which 
track closed upper low will take which will determine where the 
heaviest quantitative precipitation forecast amounts will be located. Most of the forecast area 
will see a good chance for precipitation during this period with 
strong forcing and ample moisture associated with the trough. 
Have raised probability of precipitation to categorical in the Southwest Mountains Monday 
and increased them over the western and central areas also. 
Precipitation will continue Monday night and linger through 
Tuesday as the upper trough moves slowly out of the area. 
Northwest flow setting up on Wednesday with the GFS/European model (ecmwf) 
bringing another trough through the area for a chance of showers. 
Models begin diverging by the weekend as GFS brings a ridge over 
the northern plains whereas the European model (ecmwf) builds a ridge over the 
eastern Pacific and keeps the forecast area in a north flow for 
continued unsettled weather. Made only minor changes to the 
extended forecast for Friday into the weekend with major 
discrepancies. 


For temperatures...big change coming Monday as daytime highs will 
only be in the 50s. Temperatures will slowly warm through the 
week and will not reach seasonal normals until the weekend. 
Richmond 


&& 


Aviation... 


VFR conditions expected across the entire area today. No aviation 
hazards anticipated. Richmond 




&& 


Preliminary point temp/pops... 


Today sun Monday Tuesday Wednesday Thursday Friday 
------------------------------------------------------- 
bil 097 060/073 048/055 043/060 043/071 047/066 044/063 
0/u 03/T 87/r 75/r 00/b 23/west 32/west 
lvm 093 051/069 045/054 038/059 038/067 039/062 037/060 
0/north 24/T 87/r 63/r 02/T 34/west 32/west 
hdn 099 060/076 051/057 044/060 043/072 049/067 045/064 
0/u 03/T 87/r 75/r 00/b 23/west 32/west 
mls 100 062/080 052/059 045/058 044/071 049/070 047/064 
0/u 02/T 55/r 75/r 20/u 23/west 22/west 
4bq 100 063/086 054/062 045/058 043/071 049/070 047/064 
0/u 02/T 55/r 74/r 10/b 33/west 32/west 
bhk 099 060/086 053/063 044/057 042/069 048/069 044/062 
0/u 02/T 55/r 66/r 20/u 23/west 22/west 
shr 096 058/077 050/058 042/060 039/070 044/066 042/063 
0/u 03/T 56/r 75/r 00/b 23/west 32/west 


&& 


Byz watches/warnings/advisories... 
Montana...red flag warning in effect until 9 PM MDT this evening for 
zones 28-34-39>41-56-63>68. 
Red flag warning in effect from noon today to 9 PM MDT this 
evening for zones 29-33-35-37-42. 
Wyoming...none. 


&& 


$$ 
Weather.Gov/Billings