Friday’s Severe Weather Threat March 31, 2010

It wouldn’t be the Easter weekend without the chance for showers and storms.  We’ve noticed over the last several weeks that the upper level pattern has slowly started to wake back up; in other words, the pattern has become very amplified.  Fortunately, we’ll remain dry for Saturday and Sunday for the outdoor Easter egg hunts. 

Our next chance for severe weather will be Friday late afternoon and evening.  The SPC has issued a slight risk for severe weather across eastern Oklahoma and western Arkansas. 

Timing:

Showers and storms should hold off until after 3 p.m. on Friday.  Warm temperatures aloft will cap the atmosphere and keep the convection from firing.  The combination of peak heating, moisture transport, and a cold front will ignite the showers and storms toward the evening.  Plan on showers and storms through 10 p.m. on Friday.

Questions:

There are some questions with this severe weather forecast.  The first will be the amount of low level moisture on Friday.  Forecast models transport lower 50 dewpoints across eastern Oklahoma and western Arkansas.  That would be enough for severe weather; however, the real deep low level moisture looks to stay to our south. 

The second question is the amount of cloud cover for Friday.  I think we’ll see a mix of clouds and sun during the afternoon.  That should be enough for CAPE values to reach around 1,000  J/KG.  That type of CAPE would indicate the chance for quarter size hail stones within the strongest cells.

There is also enough wind shear with this next event to warrant an isolated tornado threat.  If storms can develop and get rooted in  the boundary layer, there’s enough shear to spin up tornadoes.  The greatest threat with this event would be a squall line ahead of the cold front.  If storms can’t get ahead of the front, the tornado threat would likely be low.

Drew Michaels

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WEEKEND WEATHER FORECAST March 31, 2010

The weather should cooperate for your Easter Holiday this weekend.  We could have a few thunderstorms early Saturday morning, but most of the rain will be out of the area by the late morning.  We will keep clouds with us for Saturday afternoon, but the sunshine will return for Easter Sunday

BLOG ENTRY BY: PATRICK CRAWFORD (3-31  6AM)

http://www.twitter.com/4029weather

Was the Term Tornado Actually a Bad Word? March 30, 2010

Since our severe weather season has arrived, I thought this would be an interesting read for everybody.  It’s always neat to go back and learn more about the history of tornado forecasting.  This information was found on the SPC Tornado FAQ page!

Before 1950, at various stages of development of the Weather Bureau, the use of the word “tornado” in forecasts was at times strongly discouraged and at other times forbidden, because of a fear that predicting tornadoes may cause panic. This was in an era when very little was known about tornadoes compared to today, by both scientists and the public at large. Tornadoes were, for most, dark and mysterious menaces of unfathomable power, fast-striking monsters from the sky capable of sudden and unpredictable acts of death and devastation. As the weather patterns which led to major tornado events became better documented and researched, the mystery behind predicting them began to clear — a process which still is far from complete, of course. In 1950, the Weather Bureau revoked the ban mentioning tornadoes in forecasts.

Drew Michaels

Follow us on Twitter at “4029weather”

 

Waterfall Season March 30, 2010

Now that spring is here, the warmer air has arrived and so have the spring rains (and snow melt) over the past 2 weeks. That has fed local creeks, streams, and waterfalls! Waterfall season runs through the winter and spring months in our area with the best flow taking place typically in late February, March, April, and early May during the “rainy season” when the trees and vegetation aren’t drinking all of the excess water for themselves. Here are a few pictures that I have taken at area waterfalls over the past week. The last picture is of some new spring growth in the forest. Baby ferns are popping up all across the Ozarks.

Glory Hole Waterfall

Twin Falls also known as "Triple Falls"

Copton's Double Falls

Artist Point Falls

Bottom Of Artist Point Falls

New Spring Growth...Baby Fern Plants Waking Up

Ross Ellet

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ARE YOU READY FOR SOME FOOTBALL? March 30, 2010

Today is the start of Spring practice for your Razorbacks and the weather couldn’t be any better to get out and watch some football!  You might want to grab the sunscreen with all the sunshine that we are expecting today.  Here is a look at the forecast for this afternoon.

BLOG ENTRY BY: PATRICK CRAWFORD (3-30  4AM)

http://www.twitter.com/4029weather

Get Your Mowers Ready March 29, 2010

The spring weather this week will help to kick off the growing season. Cool season plants and grasses are already off to a healthy start and the warm season plants and grasses may see some life by late this week. The current ground temperatures are around 52 degrees in northwest Arkansas and 54 degrees in the River Valley.

Current ground temperatures

Once the ground temperatures reach certain levels it signals trees, flowers, grass, etc to come out of winter dormancy and into spring bloom. With the huge warm up in store this week ground temperatures will reach 65 degrees across the viewing area for 3 days in a row. That is warm enough to begin waking up even warm season grasses such as Bermuda. Over the next one to two weeks, not only will the trees bloom but the grass should green up as well.

So has the growing season officially begun? It is possible, especially for the river valley. The growing season begins after the last day of the season with a low of 32 degrees or colder. Here are the average last freeze dates below.

Considering temperatures are expected to stay above freezing for the next week and the 8 to 14 day outlook is for above average temperatures it is very possible that the growing season may be under way for the River Valley and Ouachitas. However there is still a chance for a late season frost or freeze. In northwest Arkansas the odds are that there will still be a freeze later in April, however a freeze is not expected over the next week. According to historic freeze probabilities, there is about a 10 to 20% chance the growing season will start tomorrow in northwest Arkansas and the next freeze won’t occur until fall.

Ross Ellet

Follow us on twitter “4029weather”

High Fire Danger Threat This Week March 29, 2010

Spring is definitely in the air!  Temperatures will quickly warm into the upper 70′s and low to middle 80′s by the middle of the week!

The major warmth is in response to a dominant ridge of high pressure aloft.  You can see that ridge above.  The combination of warm temperatures, low humidity, and strong gusty winds will produce a high fire danger threat for Wednesday and Thursday.

The winds on both Wednesday and Thursday could gust as high as 40 mph out of the south.  Winds at 850 mb, or 5,000 ft, are forecast to blow around 45 knts.  These strong winds aloft will easily mix down to the surface.  If a fire gets blown out of control there are plenty of dry fuels for the fires to feed from.

Burning is not advised this week!  Our next chance for rain will come Friday evening into Saturday morning; however, Easter Sunday is looking absolutely perfect!

Drew Michaels

Follow us on Twitter at “4029weather”

A GREAT START TO THE WEEK! March 29, 2010

It will be a great start to the week today with plenty of sunshine and temperatures warming up close to average.  I also expect the wind speeds to be much lighter today so that is a nice change from the strong winds we had over the weekend.  Here is a look at the latest on  your Monday forecast:

CLOUD FORECAST (MONDAY 10AM)

CLOUD FORECAST (MONDAY 1PM)

CLOUD FORECAST (MONDAY 4PM)

TEMPERATURES FORECAST (MONDAY 4PM)

BLOG ENTRY BY: PATRICK CRAWFORD (3-29  7:30AM)

http://www.twitter.com/4029weather

Easter Forecast March 28, 2010

It will be a great week weather wise with lots of sunshine and warm days. The great weather will last through Good Friday before the return of showers and storms. Strong thunderstorms are possible on Saturday. Most of the rain should leave the area by Easter Sunday. However, the clouds and a few scattered rain showers are expected on Sunday as well. This is an early look at the holiday weekend, we will keep you updated with any changes through the week.

 

Ross Ellet

Follow us on twitter “4029weather”

Yesterdays Storm Chase March 28, 2010

Storms initially developed over our area near the border of Arkansas and Oklahoma.  I intercepted this little storm up by Winslow where I got into some dime size hail.

Winslow Lightning

I then headed back south to intercept more storms (severe thunderstorm warnings were out for Sebastian and Crawford) and then I continued east on I-40. I intercepted this severe thunderstorm near Russellville a short time later. It looked pretty good on radar but not so much in reality.

Russellville Storm

The rest of the day was pretty much a repeat of the Russellville storm with severe storms looking great on radar (with nice hook echos even) but not looking great in truth. There were a couple of stronger storms that moved south of Russellville to over towards Morrilton. While on I-40 I looked back and saw what appeared to be a large cone funnel about halfway to the ground. I managed to stop eventually but it had pulled back up by then. Here is the same area a minute later…this was near Plummerville, AR.

Plumerville Storm

I intercepted a few more storms including one that had obvious rotation (it was pretty elevated though). I did catch this spectacular lightning strike at Lake Conway. This was shot with a wide angle lens so its actually much closer than it appears – around 500ft or so.

Lake Conway Lightning

More pics and eventually video will be on my website – http://www.realclearwx.com

Post by Brian Emfinger