4/19/13 - A Temperature Roller Coaster Ride

Article By:  Lester Rhoads
Ohio Weather Blog Long Range Forecaster

We've been on a temperature roller coaster for the last several weeks and that looks to continue as we go through the rest of April and into May.  We were in the low 80s in Cincinnati yesterday and the low 40s today with even a few sleet and rain showers this evening!  What a change...  Well what are a few of the factors driving this pattern and why is it lasting so long?

First of all we are still in a pattern that favors blocking.  In the below graphs, note the AO and NAO and how they take another dive as we hit May.

As you can see, this means more strong cold fronts with 2-3 day warm up's ahead of each system and 2-3 days of a cool down behind each system.  Wash, rinse, and repeat.   The latest computer models indicate another trough coming in for next week around mid week with an associated cold front due in on Wed.  We then, will see another system next weekend and there is more beyond that taking us into the first week of May. 

The pattern also looks to remain active.  Take a look at the 11-15 day 500 MB height anomaly map for the 11-15 day period.

As you can see, a ridge builds into the Rockies with a trough along the East Coast and over SE Canada.  There is a weakness in the atmosphere that places the Great Lakes and Ohio Valley regions right in the cross hairs for continues storm system with warm up's and cool down's continuing for the next few weeks. 

For comparison, here is the 6-10 day from the ECMWF model.

The Euro produces a much colder pattern with a positive PNA type of pattern with the ridge centered further west and the trough is centered right over the Ohio Valley.  This is a much colder outcome here with a strong North Atlantic ridge.  This is not a negative NAO by the way.  So there you have it! 

Thanks for reading and I appreciate your feedback!

Active Weather Times Ahead

Good afternoon folks!  The cold and dry weather pattern that we had last week is gone.  It has been replaced by a warmer and more active pattern more typical of Spring.  In addition to the storms this week across the Ohio Valley and Great Lakes regions, after we cool down a bit on Friday and this weekend, warm air will make a return for next week.  Both the GFS and ECMWF computer models indicate more storms will be in our future.  The GFS model tries to bring in the next cold front on Monday while the ECMWF does so by Tuesday.  Both models indicate an active second half of next week!

Do we have any cold spells for the second half of April?  We just might see one!  Check out the AO Forecast.



As you can see, it takes a dip and we get cooler (Friday and this weekend).  Then it rises for next week and takes another dip just after mid month.  I am watching that period, after mid month, to see if we get another cool down similar to the one coming later this week.  This is a classic spring time battle between the warm and cold so severe weather events will become more common for the rest of April and into May as well.

Check out the GFS Ensemble Mean for the 11-15 day period.  It also agrees with a cooler pattern developing after mid month.



Basically, what we can expect going forward is bouts of warmth and cold with an active weather pattern in between.  Severe weather will also become more of a threat as well.  Enjoy the nice weather if you're reading this from Cincinnati and enjoy the storm potential later on today if you live off to the North.

March 2013 Wrap Up from NWS Office in Wilmington

Hello everyone!  While on my lunch break at work today, I stumbled upon some cool information that might interest you.  We know March was an above avg snowfall month for the Ohio Valley and the month also features well below avg, temps. 

I found some cool graphics that the NWS Office in Wilmington posted on their facebook page.  The below graphics will show you snowfall departures for March as well as precip. and temps.

In addition, after we get through this week, the models are trying to show a wetter pattern developing for next week along with a warm up to above avg temps which we will be seeing this weekend across the Ohio Valley.  By mid month, there are signs of well above avg temps developing.  For information specific to Cleveland and Cincinnati, please visit the forecast page which Bryan and I are updating on a daily basis.