Archive for April, 2008

Thursday Thunder
April 30, 2008

As we close the book on April and enter May, we also enter what is typically the most active part of storm season.  Our mind sets up a “default” where anytime there is a chance for thunderstorms, there is the potential for severe weather.

Tomorrow is no exception.  There is a chance for thunderstorms.  In central Oklahoma, that chance isn’t very high (20-30%).  The better chance for rain will be in eastern Oklahoma.  That’s also where the higher chance for severe weather will be.

The trigger will be a dryline and cold front.  It will be another windy day, but perhaps not as windy as today.  In southwestern Oklahoma, behind the dryline (where the warmest and driest air will be), the fire danger will be extremely high.  Temperatures in the southwest will likely make the 90s.  Ahead of the dryline and cold front, a few storms should develop.  As we look at the severe weather parameters, it appears the greater chance for severe weather will be northeast of Oklahoma City.

Right now, the weekend looks dry, with below normal temperatures.  Thunderstorm chances will return as we go back to work on Monday.

Andy

Winds of Change?…..or Just Wind?
April 30, 2008

Overall, I’d say the latter. But, weather really is never that static here in Oklahoma, is it. We will get another dry day out of today, but it will be warmer and windier.

The high in OKC should top off around 85 today, with the western part of the state getting into the low 90s. All of us will see winds out of the south at 20-40mph, with gusts 50+mph. There is a Wind Advisory in effect for the entire area through this evening. If you want better fuel economy, only drive north today.

The change comes tomorrow when the dryline bulges into the area. It looks to setup near I-35, which is actually good news for us. It would push the best chance for severe weather into the eastern part of the state. If I lived from along I-35 (including OKC) and East, I would prepare for the possibility of severe thunderstorms tomorrow.

A cold front then sweeps in behind the dryline clearing us out and turning us a bit cooler for Saturday and Sunday.

I want to thank Gary for his comment on my last post saying that I’m the best weatherman ever. “Gary”, I’m sure you’re a family member or friend, but I appreciate it. If you’re not, I owe you five bucks.

Rusty

Windy Weather To Continue
April 29, 2008

The heat was on again today with highs in the 80s across all of central and western Oklahoma.  Along with the above normal temps, the wind was starting to increase.  Southerly winds were gusting 20 to 40 mph.

Tomorrow will be even windier with gusts over 40 mph out of the south.  Highs will be in the 80s once again.

Thursday will remain warm and windy, but there will be a chance of storms developing in the afternoon.  I-35 looks like it will be a good starting point for the storms by late afternoon.  Once the storms develop, they’ll move into eastern Oklahoma and they’ll have a chance of being severe.  The trick is to determine whether the storms form right along I-35, or a little west or east.  If it is west, the OKC area has a better chance of storms.  If it is farther east, OKC gets nothing.

Right now I have a 30% storm chance in the forecast Thursday afternoon, with higher chances east.  If the ingredients come together, an outbreak of severe storms is possible, especially east.  We’ll be watching this carefully.

Friday and Saturday will be dry and cooler.  More rain is possible Sunday through Tuesday.

Rick

Cold Front Detected on Advantage HD
April 28, 2008

You may have noticed a thin blue line moving through the state on Advantage HD. This line is actually a backdoor cold front. The front is moving through central Oklahoma with slightly cooler air. Here is a view from Advantage HD: 

Frontal compression ahead of the front led to temperatures this afternoon in the upper 70s and low 80s. The air behind the front isn’t terribly cold, but we will be a few degrees cooler tomorrow afternoon with highs in the mid to upper 70s. This slight “cool down” won’t last too long—highs will be back in the 80s by Wednesday and Thursday!
 
Vivek Mahale
Meteorologist Intern
 

 

Big Temp Swing Today
April 28, 2008

Were you up at 4 this morning for the record low in Oklahoma City?  Light winds and clear skies last night were prime for radiational cooling.  The new record from this morning is 35.  The old record was 37 set back in 1939. 

And then we had another surprise this afternoon- the high temperature making it almost up to 80.  Compressional heating ahead of a weak cold front that slipped through the metro allowed for the warm-up.  We started out this morning 17 degrees below normal and warmed up to 4 degrees above normal this afternoon.  That a 44 degree swing!

We will stay warm and breezy for the middle of the week.  Tempatures will be in the 80s on Wednesday and Thursday.  We’re watching for the possibility of thunderstorms Thursday evening as a dry line sets up to the west.  It is a low chance though, with deep moisture and timing being limiting factors.

Enjoy the sunshine this week and stay tuned to KOCO for all the latest!

– Alek Krautmann

Weather Intern

Dry and Chilly to Kickoff Week
April 28, 2008

Temperatures this morning plummeted well into the 30s in most locations. I didn’t see any frost myself, did your backyard get any? The winds stayed up just enough to limit the frost potential in most areas..  The coldest temperatures were actually in the Southcentral part of the state from Pauls Valley to Ardmore. A few spots dipped below 32 for a brief time there.

We are in store for a nice warmup across the state. Temperatures should climb well into the 70s in most locations, thanks to plenty o’ sunshine and a brisk southwest wind. A backdoor cold front will move into the northeast part of the state and could get as far southwest as the metro. The only influence it will have will be to bring a northeast wind and have the temperature end up a few degrees cooler than otherwise.

I think we continue to see the temperature climb through Wednesday, reaching the mid 80s by then. The next chance for storms appears to be on Thursday as the dryline takes up residence in the western part of the state. And yes, some of those storms could be severe. Behind the dryline, relative humidity values could drop into the single digits, so the wildfire threat will be elevated.

Rusty

Cool Sunday
April 27, 2008

We saw scattered showers across the state this morning.   The rain should be out of the state by early afternoon.  North winds behind a cold front, and the clouds/rain around this morning, we should only warm into the 60s this afternoon.  I’m forecasting a high of 64 in the OKC metro area today, which is 10 degrees below normal.

Tonight will be chilly.  There could be some patchy frost along and north of I-40.  There won’t be a freeze, but if you have very tender plants and you live in northern Oklahoma, you will want to protect them tonight. 

Our warming trend will start Monday.  Monday should be sunny.  After the cold start, we will warm into the 70s.  We will keep warming throughout the week, eventually reaching the 80s for highs.  By Thursday, our next front moves through with a slight chance for thunderstorms and cooler temperatures.

Don’t forget our “Severe Weather Safety Show,” Monday night at 6:30.  It will be held in Midwest City at the Reed Center.  This is our third attempt to hold this–we had snow the first time and severe weather the second time.  The weather should be perfect this time!

Andy

Nice Afternoon
April 26, 2008

It’s a really nice early Saturday afternoon across the Sooner State.  I’m actually writing this from my back porch, thanks to my laptop and wifi.  Temperatures are into the 60s and we have mostly sunny skies.

A cold front is approaching northwestern Oklahoma.  This front will move across the state tonight and early Sunday.  There will be the chance for a few showers and thunderstorms with the front.  I don’t see a widespread severe weather event, but there could be some stronger storms in southern Oklahoma.

There isn’t much wind today–that will change with the cold front.  Winds late tonight and tomorrow will be out of the north at 15-30 mph.  Temperatures will be cooler tomorrow.  There will likely be a freeze in the panhandle and some frost in the northwest tonight.  Monday morning could bring frost to a larger part of the state.

Monday morning is when we should see our coolest temperatures.  From there, temperatures will rebound through the upcoming work week.  We could see a few thunderstorms late in the week.

Andy

Blue Sky Bust–Why?
April 25, 2008

I went chasing yesterday with some friends, hoping to see some storms.  Or rather we drove to Enid, near the dryline, to wait to see if things fired.  We were met with blue sky everywhere all around us.  Needless to say, we were very disappointed that nothing, not even a single cloud, formed.  It’s frustrating to be excited about a possible chase and then have nothing happen time after time.  That seems to be the case in Oklahoma this year.  This “chase” was definitely the worst though–every other time there’s at least been a storm to take pictures of and a good lightning show to enjoy.  🙂

There were a few things that might have impacted why there was no storm activity yesterday in Oklahoma, despite the soundings looking favorable and severe weather indices indicating good conditions.  CAPE (convective available potential energy, the amount of energy available to a storm in the atmosphere) was 3472 J/kg.  On the CAPE scale, over 2500 J/kg indicates an extremely unstable atmosphere.  The SWET and K indices showed favorable numbers for isolated tornadoes.  The wind profile looked good too, with veering wind and warm air advection from the surface up. 

The only thing that didn’t happen was an initiation event to start a storm.  This could have been due to an extremely large inversion near the surface (called the “cap”) that was difficult to break.  Inversions are parts of the atmosphere that are extremely stable, and the steeper the inversion is the harder it is for clouds to break through to the unstable atmosphere above.  Rick thinks the bust was also due to a lack of convergence on the dryline and subsidence (sinking) air behind it.  Drylines are good places to look for storms because of the sharp difference between moisture in the air.  The density differences cause the warm moist air to wedge under the dry desert air like a cold front and can help cause convergence.If nothing converges on the dryline, nothing is able to form.  This, apparently, is what happened yesterday.  Storm season in the Southern Plains is still active through the middle of May, so we’ll see what happens in the coming weeks.

Stay tuned to KOCO for all your weather needs!  Have a great weekend!

Kara Bolognini

Weather Intern

Oh Cold Front
April 25, 2008

Bit of a change this morning huh? That cold front certainly carried some cooler air with it and some scary looking clouds. I actually had a few people call in asking if there was a risk of severe weather.

There will be a slight risk for the extreme southeast part of the state later this afternoon. For us, it will be a fairly chilly afternoon, in stark contrast to the last couple of days. We will see some clearing , it will just take some time. High should reach near 70, but it won’t feel that warm as the brisk northwest wind will continue at some 15-30mph. At least it will be a dry afternoon for the Festival of the Arts. Have a great weekend.

 

Rusty