Canadian Weather: Colorado Fever - Canadian Weather

Jump to content

Page 1 of 1
  • You cannot start a new topic
  • You cannot reply to this topic

Colorado Fever Rate Topic: -----

#1 User offline   Frozen Tundra Icon

  • Community Member
  • PipPip
  • Group: Members
  • Posts: 28
  • Joined: 05-July 08

Posted 27 March 2009 - 02:03 AM

Very active pattern in store for Eastern and Central N America over the next 10 days.

Persistent blocking along the Atlantic causing upper ridge over the Midwest and longwave trough over the Rockies. Each time a disturbance enters N America from Pacific the pattern becomes re-amplified...

We already had a Montana low and Colorado low.. GFS goes crazy with 3 more systems over the long range.

Trailing piece of energy rotates thru base of longwave trough left over from first Colorado Low. This spins up a dreaded "panhandle hooker" (lol) that may give a swath of heavy snow to places like Green Bay and Sault Ste. Marie.

Then another disturbance now over the Pacific moves in and re-amplifies the longwave trough over the Rockies... and guess what? Another Colorado low emerges with the eastern prairies possibly affected by inverted trough around Mar 30/31 (lots of model uncertainty still).

A third impulse is then shown by GFS to carve out the western trough yet again. This generates Colorado Low number #3 around Apr 3/4. This one actually is the most impressive looking. Upper trough becomes very negatively tilted... to the point that there is sharp SE flow ahead of the upper low.

The strength of blocking in the Atlantic will determine how amplified the pattern becomes... the stronger it is, the more likely the storms will be deflected towards the eastern prairies. The weaker it is.. the more progressive the storms will be, aiming at N Ontario perhaps.

Either way, it looks like S Ontario will receive several rounds of warm, moist advection from the Gulf of Mexico with widespread elevated convection possible. Here on the eastern prairies.. each low will simply re-enforce the cold pool of air over N Canada... sigh.

#2 User offline   Frozen Tundra Icon

  • Community Member
  • PipPip
  • Group: Members
  • Posts: 28
  • Joined: 05-July 08

Posted 05 April 2009 - 12:37 AM

Well the Mar 30/31 gave significant precip to the Red River Valley and NW Ontario. Wet sloppy accumulations of around 15-20 cm around Winnipeg (initially much of the snow did not stick). Well don't look now, but the parade of Colorado lows will keep marching on...

The current low (Colorado Low #3) is bringing heavy snow to Sioux Falls SD. By the time it 'leaves the building', there will be a contiguous snowpack all the way down to Omaha, Nebraska... ufff.

Every 4-5 days a new disturbance drops south along the pacific coast and ejects out of Colorado. This is what GFS is advertizing:

Around Apr 8/9 Colorado low #4 will take a progressive eastward track thru the central and southern plains. Its main effect will be to re-enforce cold high pressure on its back side. This will suppress any real warmth off towards Alberta.

Then Colorado low #5 steps up to the centre stage. This guy looks interesting with a sharp SW upper flow ahead of it. At the surface there will be an inverted trough and a warm moist fetch to its right. QPF lights up on Apr 13/14 over RRV... 850 hPa warm enough for rain with embedded convection possible... uh oh.

Page 1 of 1
  • You cannot start a new topic
  • You cannot reply to this topic

Icon1 User(s) are reading this topic (0 members, 1 guests, 0 anonymous users)