A plume of moisture rich air has been fueling a line of thunderstorms that stretches northward along a front. The front is attached to a powerful mid-latitude cyclone that is passing through the states, north of our area. Quite a bit of jetstream energy has helped fuel the intensity of the storms.

We've had Severe Thunderstorm warnings in Delaware, Cherokee, Addair and Sequoyah counties in Oklahoma along with Carroll and Washington counties in Arkansas. The biggest threat with storms has been gusty winds, possibly in excess of 60 mph along with hail, possibly up to the size of golf balls. The line of showers and storms is continuing to lessen in intensity as it pushes to the south east. By the morning we may have some patchy fog in low lying places which should give way to a good bit of blue by the afternoon. After Tuesday / Wednesday, rain chances drop until the weekend. If some of the latest long-range data holds, next week could be CHILLY!

Welcome to the fall. The sun angle is quickly decreasing, and cold air is really starting to pool to our north. With all of that said, we're talking about an active jetstream, and that's a sure sign of the fall. season The jetstream's strongest winds occur during the winter; however, they do start increasing throughout the fall, and that can spell severe weather outbreaks.

Severe weather may be an issue to our north this weekend. Look at the jetsream to our north. Divergence aloft will mean rapid lift for showers and storms throughout the upper Midwest. We call this a negatively tilted trough, which is very indicative of severe weather when moisture is present.

With most of the dynamics to our north, we'll only see a slight chance for showers and storms on Sunday.

Another disturbance aloft ignited more showers and storms across the area today. Rain and storms moved across eastern Oklahoma and western Arkansas leaving some spots under an inch of water. All in all September has been a wet month in many spots, but it looks like we'll finish out the month with dry weather.

Tropical Depression #13 is taking currently spinning in the Gulf of Mexico. This system looks to take on Tropical Storm characteristics later today or early Thursday morning. Weather models don't really know what to do with this depression, but it looks like it could send some moisture into Southern Texas over the weekend.

Tropical Storm Karen is located about 1285 miles East of the Windward Islands. She is moving West at 14 mph and is showing a gradual turn to the West-Northwest over the next 24 hours. Karen's maximum sustained winds are 50 mph with even higher wind gusts. She should begin to strengthen in the next 24 hours and she could become a hurricane by Thursday afternoon.

A large area of high pressure continues to dominate the east coast. Winds around this high are ushering in southerly winds straight off the gulf of Mexico right into our area. Over the last couple of days we've seen southerly winds pumping dewpoints back in the 60's throughout eastern Oklahoma and western Arkansas.

This type of airmass is more reminiscent of spring, and it could fuel showers and storms Tuesday afternoon and evening. A cold front will provide the lift for the showers and storms. The severe threat should remain low. Limited wind shear and warmer temperatures aloft will suppress large hail; however, sunshine is present, look for the chance for small hail and gusty winds with the stronger storms.

The heaviest concentration of tropical moisture in mid and upper levels from the remnants of TD #10 are now over Texas. Sunshine will stir up the atmosphere and we will still likely see some convection, though southern locations stand the better shot of this rain activity.

Tropical Depression Ten never quite earned the status of a named storm. Now it appears as if the remnant Low is taking more of a southern path as it continues to spin down and weaken. We may not see a whole lot of precipitation from this feature. There are some inherent problems with computer models and these can show up in both mid-latitude cyclones and tropical storms.

2) Resolution. Models are run on 3-D grids that cover the entire globe. Each grid point represents of piece of atmosphere perhaps 40 km on a side. Thus, processes smaller than that (such as thunderstorms) are not handled well, and must be "parameterized". This means we make up parameters (fudge factors) that do a good job giving the right forecast most of the time. Obviously, the fudge factors aren't going to work for all situations.

3) Basic understanding. Our basic understanding of the physics governing the atmosphere is imperfect, so the equations we're using aren't quite right.

The Gulf Coast is watching this upper level low very closely over the next several hours. It could possibly take on tropical characteristics over the next 24 hours. If that is the case it will be called "Jerry".

The National Hurricane Center sent a reconnaissance aircraft earlier today to investigate the tropical circulation 150 miles west of Tampa, FL. Right now there are signs of organization with this system, and over the next 24 hours, it will likely strengthen over the open warm water. This could turn into Tropical Depression Jerry by Friday.

We'll see chances for showers and storms starting Sunday from this tropical system. Saturday looks warm and dry before the thicker clouds roll this way.

It looks like we will begin the "Fall Season" on a rainy weather note. Tropical moisture begins to move into the area Saturday night as a low pressure systems moves out of the Gulf of Mexico. The track of this low will have to be watched carefully. Models are trying to move it directly over the area. If that is the case, we could be talking about significant rainfall totals. Here is the Quantitative Precipitation Forecast (QPF) from the National Weather Service (NWS) from Sunday morning into Tuesday morning. Storm totals could be near 1.50 inches by Tuesday. Of course, you know we are watching this system very closely. Keep it tuned to 40/29 TV and 4029tv.com for the very latest.

A mysterious illness strikes a rural area of Peru after something falls from the sky. Sounds like the plot line for some sort of sci-fi movie involving aliens right? Well, this time its really happening! On Saturday afternoon (9/15) residents of the remote Puno region of Peru noticed a bright "fireball" descend out of the daytime sky and crash to the ground. When residents went to the crash site they found the crater pictured above. The crater is about 100 feet wide and about 20 feet deep. Scientists have investigated and now believe that it was indeed a fireball meteor. Meteor impacts of this size are very rare. The energy released during impact could have been as much as a small tactical nuke or 1 Kiloton of TNT. After visiting the site, residents complained that it "smelled bad" and furthermore several of the local residents began to become ill! 200 residents have now been treated for various problems including migraines, vomiting, dizziness, and other various symptoms. Scientist have now determined that the residents didn't become sick from the meteor itself but from gas that was disturbed by the impact. The region of Puno, Peru is a geologically active area with hot springs, earthquakes, and even volcanoes and that likely explains the gas. Scientists plan to drain the water out of the crater in the hopes of finding the actual meteorite.

During the last week there has been a large number of reported fireball meteors. Several have even been caught on video by astronomers. My camera caught two meteors on Sunday morning and can be viewed here. I also received a email on Monday night from a individual in Northwest Arkansas who (while walking his dog) saw a bright fireball meteor steak all the way to the horizon. You can keep up with the Peru Meteorite story and other space weather stories by visiting spaceweather.com

Like pesticides and fertilizers, soil washed away by rain can also pollute streams and lakes. Even if you do not live near water, stormwater runoff picks up exposed soil, carries it through the storm drain system, and deposits in regional water resources.

Gardens, lawns and construction areas with patches of bare soil, especially on sloped land, are prone to soil erosion. You can retain topsoil and reduce erosion by planting ground-cover vegetation or using woodchip mulch or landscape fabric. On steep slopes, plant a vigorous ground cover but avoid turf grass that requires mowing. Building terraces or retaining walls on slopes also can help prevent soil loss. Berms (raised earthen areas) and swales (small dips in the ground) can help retain runoff that might otherwise rush from your yard and enhance infiltration into the ground.

From an environmental point of view, yard trash accounts for up to 20 percent of the total municipal waste produced year-round. Composting is a cost-effective, natural way to transform fruit and vegetable peelings, leaves, clippings, and other yard wastes into a high-quality, soil-enhancing material. If possible, take advantage of community yard waste collection and composting programs. You can also create compost at home with one of the many compact, efficient bins on the market or you can build your own. Either way, the final product will be dark brown and crumbly with a clean, earthy scent. The smaller the particle size, the faster materials will compost, so it’s a great idea to mow, chip or shred yard and garden wastes before adding them to your compost pile. The finished compost can be mixed into garden soil or spread on lawns to help soils absorb and retain moisture and enhance nutrient availability.

A composting demonstration park is located at the Washington County Cooperative Extension Service office at 2536 N. McConnell Ave. in Fayetteville. This public facility hosts ten different types of composting bins and allows people to see for themselves how composting can work for them (call (479) 444-1755 for directions).

We have a very interesting weather pattern setting up for the rest of the week. A deepening low along the West coast will keep us warm and dry through Saturday. The ridge of high pressure will also help to strengthen a tropical wave currently located over Florida.



This wave will need to be watched closely. Conditions will be favorable for this low to develop into a depression or a topical storm along the Gulf Coast. Remember Humberto? He developed in a 24 hour period right off the coast. What's interesting about this wave is the movement. Under the high the wave will move to the west. Meteorologists call this type of movement "retrograding".




As you can see the models are predicting chances for showers and storms toward the end of the weekend across Arkansas in association with this low. We'll watch it closely.

So, we're now back into the hot stuff! Here is a little tid-bit which aims to bring some cool comfort. In just a week and a half the record books will be void of triple digit heat for the remainder of the calender year! Can I get an Alleluia!? Our recent taste of Fall was just a little too short lived. Perhaps in a week and a half we'll get another. Until then, be cool!

SOME IMPRESSIVE MORNING LOWS:

Arkansas:

XNA 51
Fayetteville 52
Bentonville 55
Little Flock 55
Springdale 56
Greenwood 58

Oklahoma:

Poteau 62
Sallisaw 59
Kiamichi 58
Grove 57
Tahlequah 55
Arkoma 63

Hurricane Humberto made landfall early this morning, yes...I did say Hurricane Humberto. Right before landfall Tropical Storm Humberto increased strength to a Category 1 hurricane. Chief Meteorologist Drew Michaels mentioned this possibility during his 10pm weathercast. The eye made landfall just East of High Island, Texas at 3:00 AM (2:00 AM local). He brought torrential rainfall along with max wind speeds of 85 mph. His wind gusts definitely packed a punch gusting to 105 mph. Now he won't hit us directly, but he will send some moisture our way over the next several hours. A cold front swings through Friday and pushes him more Southeast. He could possibly move back into the warm waters of the Gulf of Mexico and re-strengthen. That is something that will be watched very closely over the weekend.

24 hours ago, Humberto was just a minor disturbance off the coast of Texas, but now he has blossomed into a decent tropical storm. Warm Gulf of Mexico waters have helped to strengthen Humberto into a tropical storm. Humberto's set to make landfall early Thursday morning along the Louisiana and Texas coasts. Winds could gust as high as 70 mph at landfall; however, Humberto will weaken before it can strengthen into a minor hurricane. 5 to 10 inches of rainfall could fall along Humberto's path, causing inland flooding concerns.

We won't see the floodng, but SE OK and SW AR may see isolated showers and storms on Thursday. Fortunately, Humberto won't stick around for long, he'll be swept northeast by a trough over the southwest.

Temperatures this afternoon ran 5 to 10 degrees below average, all thanks to the thick stratus clouds we saw this morning! Dry air worked across Arklahoma allowing the clouds to decrease throughout the morning and early afternoon.

Tonight we look for radiational cooling to occur. Our Wednesday morning will feel more like early October. The graphic below shows where our average overnight low should be this time of the year. Here are some things to consider when forecasting for radiational cooling.



Clear sky- When skies are clear the longwave radiation is better able to escape into space. When clouds are present the clouds will reflect and emit longwave radiation back to the surface. With clouds there is less net longwave energy escape. It is ideal to have a clear sky all night.


Dry air- Even when skies are clear, water vapor in the air will absorb and emit longwave radiation. Humid air can act like cloud cover when it comes to longwave energy trying to escape. It is ideal to have low dewpoints throughout the atmosphere.

Light wind- When the wind is light, the air near the surface will not mix as much. Since the ground surface is the source of the cooling, air temperature will be colder close to the surface. When the wind is very light there will be less mixing with warmer air aloft. This is especially true if the winds aloft are light also. When winds are very light a shallow layer of cold air will develop just above the ground surface. It is ideal to have a calm wind all night.

The cold front that moved across our area this afternoon will provide a nice drop in the humidity levels. Dewpoints across Kansas are in the 50's, so we'll be nice and dry through Thursday. The GFS has been hinting at another frontal boundary to move in for Friday. This front will be very moisture starved, however, it will drop our temperatures a little for the upcoming weekend.






Right now the GFS is only giving us a glancing blow of cooler air for the weekend. Take a look at the graphic above. Look at the cold air that moves across the Midwest. 850 temperatures to our north will hover around 4 degrees Celsius. We'll see temperatures in the mid to upper 70s and lower 80s, with 850 temperatures around 8 degrees Celsius.