20080701 Wx Discussion I (1335Z)

MONTANA Weather

Well, we didn't quite make it yesterday in Butte. The high topped out at 91ºF and would have gone much higher if it weren't for the high clouds associated with nearby thunderstorms. The intense surface heating steepened valley to mountain lapse rates and combined with "generous" amounts of Pacific moisture, made it easy to reach convective temperatures yesterday. Storms fired along the Bitterroots, Pioneers, Centennials, and the Anaconda Range early in the afternoon. The high clouds blanketed most of western Montana and kept the temperatures from going any further.

There were, however, a few record highs set ... especially where the high clouds didn't shade the area:

...METAR STATIONS - WESTERN MONTANA...

                NEW        PREVIOUS
               RECORD       RECORD (YEAR SET)

MISSOULA          96 (TIE)     96 (1990)
KALISPELL         94           92 (1944)

...COOPERATIVE OBSERVER STATIONS - WESTERN MONTANA...

                NEW        PREVIOUS
               RECORD       RECORD (YEAR SET)

LIBBY             99 (TIE)     99 (2003)
LIBBY 32 SE       87           85 (1950)
POLSON            92 (TIE)     92
SUPERIOR          99           98 (1939)
WEST GLACIER      92           90 (1990)

A friend of mine in Missoula, MT called me concerning a "Tatooine Scale" sand storm around 7:00PM last night. In case you were wondering, this was probably caused by cool (dense) outflow from storms on the south end of the Bitterroot Valley, draining down the valley toward Missoula. Hamilton's winds picked up out of the south at 6PM, with Corvallis and Stevensville soon following. Missoula's wind shifted (from NNW to S) and picked up by 7PM. This seems to verify as there were storms at the south end of the valley at 6PM.



COLORADO Weather

NWS Forecast discussion is calling for storms to develop over the mountains and foothills by noon today. The models (RUC, WRF, GFS) have the entire area mixing out big time during the early afternoon, so I'm not sure exactly what they're seeing. They mention the convective temperature being reached ... but we'll see. The plains will remain stable today unless some convergence zone sets up near or off the Palmer like yesterday. Without any surface moisture, though, I don't think anyone is going to see much rain.

Dann.