9 Oct KBIL forecast

posted Oct 9, 2012, 12:08 PM by Michael Baldwin   [ updated Oct 9, 2012, 12:08 PM ]
low clouds are beginning to break up early this afternoon at KBIL, personally hoping they will hang in there for a few more hours to keep today's max temp out of the mid 50s.  however, we don't do "wishcasting" here, right? 

forecast challenges today: max wind and temps

strong NW flow aloft expected to remain in place for next day or two with KBIL located on the west side of the deep trough that is sitting over the Midwest U.S.  surface anticyclone currently right over/just south of KBIL should move quickly to the southeast tonight, flow between the anticyclone and the cyclone dropping south will set up a decent pressure gradient over MT during the day tomorrow.  forecast soundings/time-height cross section show SW flow near the surface and westerly flow in the mid levels, should be plenty of downslope flow which will warm them up considerably when compared with today.  weak subsidence/plenty of dry air expected, so precip is not an issue.  NAM forecast soundings/meteogram show a well-mixed PBL tomorrow afternoon with surface temps getting to 21C (close to 70F).  this is several degrees higher than current MOS guidance (NAM&GFS: 63) and NWS forecast (66), although I expect the NWS will be going upper 60s when the next forecast is updated.  NAM forecast soundings show max wind at the top of the PBL around 25kts tomorrow afternoon, the PBL height is ~2500m, so I don't expect to see sustained winds that high tomorrow, I'm leaning a few knots below that number (but won't be surprised if the max gust ends up a couple of kts above that number) (note: we are forecasting max sustained wind, we aren't forecasting max gust).  NAM also showing low level winds shifting around to the SW before midnight and maintaining 10kts all through the night, this should prevent them from optimal radiative cooling, but this could be a tricky forecast since skies are expected to clear and dry air should be in place overnight.  Guidance/MOS is all over the place for their min temp (GFS: 36, NAM:41, USL: 43) I'm leaning towards the higher end of this range given the wind prediction. 

I'm thinking consensus will be near 67/39/20kts/0.00" with a bit more spread than what we've been seeing lately on the temps and wind
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