Monday, February 24, 2014

March Makes For Meteorological Madness For Marathoners


8:25 AM Tuesday Update... I want to clarify something pertaining to the video.  Yes, the models are all over the place from run to run and that's why I have lower than average confidence on a forecast for next week.  With that said, they have all come back warmer pushing the boundary further north Sunday.  My problem, why should I believe it when just yesterday it was forecasting a winter storm?  Yes, we are closer to the event and there is SOME agreement, but what happens if they start trending colder again?  I do think that's a possibility since we're dealing with something several days away.  Until this system gets into the United States and gets sampled by the upper air network, I have questions as to how this will unfold.  Hope that makes sense.  Watch the video below for more.

Side by side comparison of the Tuesday AM runs of the GFS and ECMWF.  Both show the warmer air surging north early next Sunday morning, but differ on the placement of the boundary.   Look at NE Arkansas.  The GFS has the temperature in the mid 30s while the Euro is in the 60s.  Good luck Ryan! LOL
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7:15 AM Tuesday Update... As I said yesterday, this is a very low confidence forecast starting next weekend into the following week.  The GFS is having severe problems and this video demonstrates the challenges forecasting what may happen next week.  What once looked like a winter weather threat, now looks like thunderstorms.  Do I believe that right now? NO.  Check out the video





Say that 10 times fast!  Let's first start off by saying I have absolutely NO trust in the operational runs of the GFS and European models when it comes to next weekend and beyond.  Here's why.  Just yesterday, both indicated a dry and cold Sunday, but now have flipped to cold and wet.  The GFS even shows wintry precipitation.  While both have flipped to the wetter forecast, they both differ in the strength and position of the low. 

The next run of the models could easily delay or speed up the impending system or even dampen it out and take away some of the moisture.  So at this time, the extended is very much a "low confidence" forecast (Sunday and beyond).  We must watch it for any of the possibilities I listed above, especially since thousands will be here running the marathon. 

These maps are from weatherbell.com

This is the European model valid at noon Sunday.  The surface low is located in eastern Oklahoma.  I know this map is difficult to read, but I'll explain.  The northern placement of the low means the cold air (cold enough for frozen precip) is shunted off to the north of the track.  The dark blue line is the surface 32 degree line and that's well north into Kansas into Missouri.  If this solution verifies, it would be a chilly and rainy day.

Now the GFS for the EXACT TIME PERIOD.  The surface low is in west Texas (black circle).  THAT'S A HUGE DIFFERENCE.  Due to the southern and western placement of the low, cold air is able to get in front of it.  Look at the frozen precip breaking out over the state.  The orange is sleet and the purple is freezing rain.  THIS IS !NOT! OUR FORECAST AT THIS TIME.
This is the morning run of the GFS just yesterday.  It does show the system developing to the west, but leaves us dry Sunday morning.  
IN SUMMARY, THERE ARE BIG DIFFERENCES IN THE LONG RANGE WITH REGARD TO TIMING, STRENGTH, AND LOCATION.  THIS IS VERY TYPICAL WHEN FORECASTING IN THE LONG RANGE.  I'LL KEEP YOU UPDATED.

3 comments:

Bruce Wayne said...

Hey Todd, Use the force and trust the Euro for Sunday (3-2-14). I believe the NWS offices are bringing in too much cold air too quickly and not getting the low pressure center right. I believe the GFS got a cold from the GEM. Both the GFS/Euro show the low tracking over AR. GFS a little later than the Euro (12 hours). Gauging from the Euro, there is a threat of Severe Weather for areas south of a De Queen to Sheridan to West Memphis line with the highest tornado threat being over El Dorado to Pine Bluff to Helena to Lake Village. Not good CAPE but O.K. Sheer for the above mentioned areas. Similar to the February 20th tornado outbreak in Illinois in the low CAPE high Shear environment. If the Euro is right, timing is better for Severe Weather with storms coming in during the afternoon vs. the overnight with the GFS. As for the winter weather threat. It is minimal with the best chance being from Fort Smith to Mt. Home and points northwest with at MAX 1/2 inch of snow and a glaze of ice. Doubt even that though. Nevertheless, if the low pressure track does stay the same despite the differences in timing with the GFS and Euro, Arkansas will have little to no winter weather for Sunday into Monday.

jimmylee42 said...

Todd-NWS low records for the first 5 days of March. March 1-1890 16, 2nd-1943 15, 3rd-1943 11, 4th-2002 15, 5th-1960 17.

Cody Reno said...

Hey Todd, Here's some info courtesy of the NWS Springfield, Missouri from Saint Louis University that's called the CIPS Analog Threat Guidance. It's quite interesting. http://www.eas.slu.edu/CIPS/ANALOG/analog.php. I'm still not going to be surprised in the slightest to have Severe Thunderstorm or Tornado Warnings in extreme southern Arkansas with Winter Weather Advisories/Warnings in Northwest Arkansas on Sunday. This in a way reminds me of the March 20th, 2010 and the December 21st, 2013 winter storms with their storm tracks although temperature profiles and precipitation locations will be different. Also for folks like me who won't pay for Weatherbell there is a way to get the Euro model for free using weatherunderground.com. Go to Maps and Radar then Weather Models then scroll down where it says model data. Click on the sprocket and choose model ECMWF. Only goes to 180 hours but you make due. Have a great day everyone!

Octo-BRRR