8 Oct KBIL forecast

Post date: Oct 8, 2012 6:59:47 PM

ok, we are done with Pensacola, FL and are moving out west to Billings, MT

Billings sits in the Yellowstone river valley, with major mountain ranges in nearly every direction:

the Bighorn mountain range to the south/east, Pryor mountains directly south,

Beartooth mountains to their southwest, Crazy mountains directly west, Big Snowy mountains to their northwest,

and Bull mountains directly north

their temps have varied considerably during the past week or so (for example: max on Oct 2 was 82, snowed on Oct 3,

max on Oct 4 was 44), and they've already had their first snow of the season


that should give you a good idea of how quickly things can change at Billings

looking at their climo: they have a decent diurnal cycle during the fall, with normal max/min of 63/40 and record max/min of 87/17


The NWS site has a nice link to surface/mesonet obs for the region


Current obs and SPC mesoanalysis show clouds and relatively strong cold advection in place in the wake of a cold front that is associated with a cyclone currently located in northern MN. Some precip can be seen in the latest radar image just to the north of KBIL, they have also received 0.01" of precip during the day today. Models are predicting precip to last through the evening hours tonight and perhaps beyond 06Z, which gets into the beginning of our forecast period. Cold advection is expected to continue ahead of a surface anti-cyclone with is predicted to move into the region during the day on Tuesday. NAM forecast soundings continue to show relatively high RH values during the day tomorrow, indicating cloud cover for a good portion of the day, with RH values dropping during the afternoon. NAM BUFKIT soundings/meteogram brings their max temp into the lower 50s tomorrow, but other guidance (GFS MOS, USL, NWS) keeps them in the upper 40s, this seems reasonable to me with some broken clouds expected during a good portion of the day. With a weak pressure gradient as the surface high settles in, guidance is indicating weak winds for the day, strongest wind may occur at midnight tonight while the precip is coming to an end. Overnight min temps in the upper 30s are indicated by NAM meteogram with MOS guidance going for lower 30s. They look to be clearing out tomorrow night and NAM meteogram has them just as cold if not colder tomorrow at 06Z than overnight tonight. Mid 30s seems reasonable to me with the clouds/precip expected overnight. Low POPS/not much precip is expected after 06Z, I don't think you'll be penalized much either way if you go with 0.01" or 0.02" vs. 0.00"

I think we'll see a bit more spread in the numbers compared with KPNS, I'm thinking the consensus will be around 49/35/10kt/0.01", I would advise sticking fairly close to those numbers since most of the errors will be in the temperature values (in other words: only go a degree/kt or two higher/lower to be consistent with your forecast thinking) there should be opportunities to separate from the pack later in the week with a strong front predicted to drop in from the north on Thursday.