Sunday, November 27, 2011

What Systems Are We Watching for the LRC?

Recap of LRC:
-Pattern setting up between Oct. 1-Nov. 10 every year.
-Certain atmospheric features will repeat approximately 30-60 days after it occurs if this feature is within the timeframe mentioned above.
-Pattern repeats through winter, spring, into summer.
-Pattern is never the same each year.

Note about this year's LRC:
-Each cycle is 46 days long. That is, each system below would theoretically repeat every 46 days.

October 19
SYSTEM 1: October 19, 2011

An Upper Level Low was cut off from the jet stream on October 19th. The piece of energy stayed in place, putting precipitation over the same areas for a couple days, before it was nudged north back into the jet stream. Over this time period, the equivalent of around 6 inches of snow (that originally fell as rain on October 19) fell over the Michigan area/ Ohio Valley. This same system is currently repeating at the time of posting. Because this is happening, the chances of the next system occurring are rising.

November 9
SYSTEM 2: November 9, 2011

 A possible Panhandle Hooker storm came up into the Midwest/Great Lakes region, putting down impressive precipitation totals. In the 3 days pan that was measured, as much as 1.97 inches of rain was recorded in the region most affected. This would easily equate to 20 inches of snow. It's pretty crazy to think that 20 inches of snow might fall in one area every 46 days. But if the LRC pans out, the atmosphere might be able to pull this feat off. The chances of this are increasing as the 1st system is panning out. If the 46 days are true, then this system could be coming back around December 28th- right after Christmas.

12z GFS Forecasts Crushing November 30th Michigan Snowstorm

The 12z GFS is forecasting a devastating snowstorm for Michigan on November 30. While the image above encompasses 5 days from now, we have investigated and these high totals do come from the November 30th.
The interesting thing is how the NAM does not bring this solution to light. It appears that the models are divided into two camps:

Snowstorm Camp: GFS, ECMWF, JMA, UKMET

No Snowstorm Camp: NAM

(GEM has mostly rain but back-end snow, will not put in category)

I would say that there ought to be a snowstorm, but may not be as severe as some models are projecting.

Saturday, November 26, 2011

Unreliable JMA Crushes Michigan With 2+ FEET Of Snow

JMA at Hour 96
The unreliable JMA weather model is forecasting Michigan to be demolished with over 2 feet of snow 96 hours away from today. Everything above the pink line is snow. As you can see, this JMA model is ridiculously strong and beyond any chance it will verify. It is, however, fun to look at.

5-Day Rainfall Forecast Totals Could Top 4 Inches

Using HPC's 5-day rainfall forecasts, we have put together a 5-day rainfall forecast for the US.
We do believe there is potential for over 4 inches of rain to fall in the Ohio Valley and parts of the Southeast. It looks like the instigator for this rainfall will be the cold front currently progressing east over the East US. After that, another factor will be a piece of energy associated with the front moving north, deepening and being cut off from the jet stream for a little while, leaving rain to move over the same areas for a while.
Exclusive Flooding Risk Valid until Dec. 1

Cold Front Will Continue to Push Rain Through Midwest This Afternoon

The cold front currently pushing through the Midwest will continue to do so through the afternoon. The above image is for 4:00 pm CDT as the cold front will continue to push through. Behind this, colder air will sweep in as the stage is set for cooler days to begin their takeover.
At this point, it is unlikely that another huge warm burst will occur in the next week, signaling that the transition into winter is beginning. Meteorological winter does start on December 1st, so I guess it is about time for winter to start.
The rain this cold front will be putting down is fairly large- check out the forecasted total precipitation from the same model as the image above.
It looks like Chicago, IL and possibly Gary, IN could be within this heaviest precipitation after the front moves through.