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FCST 1/10-11/11 SNOW Northern Missouri

EDIT 01/11/11 1024Z:  Here is a look at the radar returns from late afternoon today across the central plains:

OLD DISCUSSION

A prolonged winter weather event is poised to provide a decent snow machine for much of the central plains.  The NWS has hoisted winter storm watches and warnings for most of NE, KS, IA and MO for the Monday through Tuesday time period.

Here is a look at some basic surface features, as well as the watches/warnings, as of 11 a.m. CST January 9, 2011:

An area of low pressure, if you can call it that, and an associated inverted trough is going to be the focus for precipitation across the four state area beginning late tonight and lasting through Tuesday morning.  The storm system can be seen very easily on this morning’s water vapor imagery in southern Canada and diving into MT.  In addition, a developing shortwave can be observed near the four corners region that will provide us our first shot of snow late tonight.  The main show will hold off until Monday afternoon and evening!

This storm system will be slow to move allowing a prolonged period of light to moderate snowfall to accumulate.  Current NWS forecasts are for 5″ to 8″ to fall.  I feel extremely comfortable with my initial forecast on January 4, 2011 of  3″ to 6″ of snow from this sytem.  Here is a look at the forecasted QPF for this storm system:

Here is a look at the HPC probabilities forecast for 4″ and 8″ of snow for the Monday-Tuesday time frame:

One other thing to note is the strong winter storm that is going to affect the Gulf States region and eventually the southern Atlantic Coast.  This storm will produce ice and snow on a level not normally seen in this part of the country.  In addition it is helping stream gulf moisture northward that will ultimately interact with our snow machine to allow ample moisture to be available for decent snowfall. The interesting and devastating weather from 2010 continues into the early part of 2011. ~ CS

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2010 SPC Tornado and Severe T-Storm Watches by County

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2011 Arctic Air Intrusion / Snow

UPDATE: 01/07/11 0230Z:  The southern stream surface low pressure is going to track further south and not have an impact on our weather.  However, the northern stream is going to provide a storm system that will be impacting our weather in the Sunday through Tuesday time frame.  This will give us a shot at accumulating snowfall across a large portion of Western and Northern MO.  I am still thinking a 3″ to 6″ snowfall is very possible with this system for the local area.  Albeit, the GFS is forecasting Snowmageddon across NE KS, SE NE and SW IA with over 16″ of accumulation.  Not buying into this just yet as these type of snows are very rare for our area.  However, QPF in the aforementioned area is forecasted over 1/2″.  Definitely something to keep an eye on as we head into the weekend.  One thing for certain is it is going to get a lot colder next week.  A fresh snow pack to our north will have a big impact on overnight lows and daytime highs.  This will be coldest air this winter season!

Here is a look at the current surface low and forecasted tracks.  Note there is a clipper system providing snow to NE MO and NW IL this morning.  Happy Friday everyone. ~ CS

Current regional NEXRAD view (automatically updates):

OLD DISCUSSION:
The first true arctic air of the season is building in the northern territories and is going to make a dive into the CONUS beginning as early as next week.  A cross polar flow has set up and will continue to tap into Arctic air and drop temperatures across the northern territories.  High temperatures will struggle to reach the 0F mark toward the end of the weekend. 

Here is a look at the current temperatures across the northern territories and the Canadian provinces closer to the CONUS:


The GFS has been advertising very cold temperatures spilling into the CONUS next week.  Some of the model runs have put afternoon high temperatures below 0F across the Midwest.  Albeit, the models have really backed off on the cold air spilling southward the latest model runs. 
Here is a look at the GFS forecasted highs next Wednesday January 12, 2011:

Ok, what about precipitation and winter precipitation.  Well the first shot comes during the middle of the upcoming weekend with a shortwave moving out of the southern plains.  The track of this shortwave will be important to the type of wintry precipitation we get and how much.  As it looks right now I am anticipating as much as 3″ to 6″ for the local area.  This of course is all subject to change based on the track of the shortwave and available moisture.

Here is a look at the QPF for January 8-10, 2011:

It is going to be something we need to watch as we head toward the end of the work week and into the weekend.  The mild winter we have had thus far looks to come to an abrupt end, we knew it couldn’t last forever. ~ CS

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Impressive Storm

An impressive, record breaking storm system continues to impact the Upper Midwest, Great Lakes and Ohio Valley region as I type this blog.  Blizzard warnings, heavy snowfall, very strong winds (thunderstorm and non-thunderstorm), severe thunderstorms and tornadoes have impacted nearly 1/2 of the CONUS over the last 24 hours. ~ CS

Here is a look at the pressures, frontal positions and selected METARS as of late this afternoon:

Here is a Public Information Statement from the NWS in Duluth, MN:

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE DULUTH MN
1055 AM CDT TUE OCT 26 2010

…MINNESOTA ALL TIME LOWEST PRESSURE RECORD BROKEN THIS MORNING…
…PRESSURE IS STILL FALLING AND WILL CONTINUE INTO THE AFTERNOON…

REMEMBER THAT THIS INFORMATION IS PRELIMINARY. THE LOW IS STILL STRENGTHENING SO THE VALUES LISTED BELOW ARE LIKELY TO CHANGE. AN UNUSUALLY INTENSE LOW WAS AFFECTING THE STATE OF MINNESOTA THIS MORNING.

AT 1013 AM CDT…THE AUTOMATED WEATHER OBSERVING SYSTEM AT AITKIN MINNESOTA RECORDED A 962.3 MILLIBAR /28.42 INCHES/ PRESSURE. THIS BREAKS THE ALL TIME MINNESOTA STATE RECORD FOR THE LOWEST OBSERVED PRESSURE.

THE PREVIOUS RECORD WAS 962.6 MB SET ON NOVEMBER 10 1998 AT ALBERT LEA AND AUSTIN IN SOUTHERN MINNESOTA. IT SHOULD ALSO BE NOTED THAT DULUTH BROKE THEIR PRESSURE RECORD. AS OF 1028 AM…THE PRESSURE AT DULUTH WAS 962.9 MILLIBARS /28.44 INCHES/. THIS BREAKS THE PREVIOUS RECORD OF 964.3 MILLIBARS WHICH OCCURRED ON NOVEMBER 10 1998.

PRESSURE RECORDS AT INTERNATIONAL FALLS WERE ONLY AVAILABLE BACK TO 1948. THE LOWEST PRESSURE PREVIOUSLY AT THAT LOCATION WAS 971.9 MILLIBARS ON OCTOBER 10 1949. THE PRESSURE AS OF 1024 AM WAS 967.4 MILLIBARS /28.57 INCHES/. THEREFORE…INTERNATIONAL FALLS ALSO BROKE THEIR PRESSURE RECORD.

THE LOW CONTINUES TO DEEPEN AND THE PRESSURE WILL LIKELY CONTINUE TO FALL. THEREFORE…THIS STATEMENT IS PRELIMINARY AND WILL BE UPDATED ONCE THE LOWEST PRESSURE IS FINALLY OBSERVED. THE LOW WAS AT ABOUT 983 MB ONLY 24 HOURS AGO OVER CENTRAL SOUTH
DAKOTA. THAT IS A PRESSURE DROP OF ABOUT 21 MILLIBARS IN 24 HOURS.

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FCST: October 23, KS, NE, IA, MO

TARGET: Redding, IA by 3 p.m. CDT (Albeit family obligations are going to keep me home)

DISCUSSION:
The below water vapor imagery depicts a large trough and several shortwaves that are going to interact with a front and surface low over the central CONUS on Saturday.  One shortwave is visible over northern NM/SE CO with a trailing dryline into the TX panhandle region.  Another impulse just coming ashore on the CA coast.  The right side of the image shows the mid level low in central NE with another front associated with a surface low over northern MN is evident in the northern portion of SD.  The latter is providing the showers we are experiencing in NW MO as I right this blog.

Here is a look at the 0Z/23 surface chart:


Here is the forecasted surface features for Saturday afternoon and evening:

Speed shear dynamics are not lacking with this system but I would like to see some more directional shear at the mid-levels.  Here is a look at the NAM and GFS 250mb charts for 0Z/24.  The ECMWF is for 12Z/23.


Here is a look at the NAM and GFS 500mb chart for 0Z/24:


Helicity values are appreciable in the target area:


Here is a SKEW-T / Hodo from Redding, IA at 23Z/24:

A strengthening low level jet will also be feeding into the area providing a decent moisture transport regime:

SBCAPE from the NAM and GFS:


The last images are forecasted precip from the 4km WRF for 0Z/24 (small caveat: the precip models have not been doing a very good job of late):

All that being said tomorrow has the conditional threat for a severe weather event with all modes of severe weather possible, albeit, the tornadic threat will be early on in the event. The most likely area to see tornadoes is along the IA/MO border where shear and helicity values will be enhanced.

Any existing outflow boundaries from overnight convection and residual cloud cover will have a drastic impact on tomorrow’s threat. Throw in the sun angle for late October and it is imperative for clear skies to be around at peak heating to destabilize the atmosphere. As we saw today in TX, OK and KS, a thin veil of 250mb/300mb clouds and lack of any appreciable forcing will make all of the difference between severe weather and a few severe reports and thundershowers. ~ CS

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steve polley storm chaser