:: Clear and Calm for Now
This morning was spectacular...some low fog in the river and creek valleys, but after 0830 or so, any fog that had crept up the hills had burned off, and we have a bluebird sky day...calm winds, and a crispness to the air that is remarkably fall-like. 14Z METAR plot shows high pressure ridge lined up from KMSP southwest through KSPW, KMCI, and back towards the TX panhandle. 14Z run of the RUC model tags the ridge up nicely in accordance with analysis, and trends the ridgeline to get blocked, running KSAW-KSTL-KDFW by 00Z this evening. (Blocking from the last slow-moving, partially cutoff distubance running up on the Appalachains.)
Meanwhile, the next weather maker for us will continue a generous pace into the Pac-NW today. Satellite imagry already shows the trough moving over the Canadian coast southeasterly towards the Columbia basin. The GFS shows the trough deepining via a potent upper jet (125kt max). On the lee side of the Rockies, surface low pressure is already developing across the MT/WY badlands, and the pressure gradient with the blocked ridge over the MS valley will increase. This will expedite the southerly flow in advance of the Pac-NW trough, and sfc winds will increase dramatically through Thursday and into Friday.
Both the NAM and GFS have moderated on moisture transport...but only slightly. Now Fri-Sat period Pwat values have fallen below 4cm, but now that we see better transport features in the models with the dramatic southerly flow, these values, along with Td's could race up to midsummer-like values on Friday in advance of the system. Models have not generated any other convective weather indications that would warrant svr outlooks, but the GFS favors a coupled-jet structure, with the jet max nosing in over the Couteau des Prairies into western/southwestern MN for Saturday. Classic, and typical signature of a convective event for the area on Sat night. Slight modifications for the forecast...
WEDNESDAY...Sunny and warmer, High 76. Low 56. North wind 5mph shifting variably to the east-southeast.
THURSDAY...AM fog burns off, Partly Cloudy and 82. Winds SE 10-15 by evening. Low 57.
FRIDAY...Partly cloudy, more humid, gusty south winds 15-20. High 84, low 60 through.
SATURDAY...Partly cloudy, 40% chance of showers and thunderstorms after 7pm. High 83. Low 63.
SUNDAY...Partly to mostly cloudy. High 73. Chance of rain in AM and again in afternoon.