Saturday, April 25, 2009

Round #1 Over with no nader but some good storms

Here are a couple pictures from todays chase. Storms remained fairly high based and never really looked great at the lower layers. Very large hail and some great storm vaults we very evident with each supercell. Round #2 is tomorrow and could be the day of tornadoes. So I'm heading to bed and I'll try to have a full report later this week. Hope you enjoy the pictures....











Heading west towards on I-40

Sunny skies with a puffy cu field overhead but with a capped look. Temperature currently is 83 degrees with a dewpoint of 66. Strong southeast wind 15-25mph continues to pump in the moist air. A tornado watch has been posted until 4z (11pm) as models and current conditions says initiation is within a hour away. Looking at the latest RUC the bulls eye of greatest tornado parameters continues to be just south of I-40 in Washita, Greer, Beckam, and Northern Kiowa counties. This is maximized at sunset between 23z and 2z with llj making 0-1km helicity values scream out strong or violent tornado. Map Below......


Tornado Watch now issued until 11pm for Very large hail up to 3inches in diameter and tornadoes.
Right now nothing on radar but visible satellite starting to show agitated cu to the west. Another update possibly later......

Chase Mode is in progress across Western Oklahoma

Very unstable atmosphere currently across all of Southern Plains as a cold front surges south and a dryline sets up to the west. Looking at the current surface analysis along with visible satellite. Things look like a go for widespread severe weather and a regional tornado outbreak across Western Oklahoma.

The morning models show a very favorable environment for rotating supercells capable of very large hail, damaging winds and strong tornadoes. Storm relative helicity prior to sunset runs at a pretty high rate 300 j/kg especially with over 3000 joules of surface base CAPE. Then what is a little scary is the ramp up to nearly 550 j/kg. This nearing the parameters capable of producing strong long tracked tornadoes with a mature supercell.

Models continue to differ on exact location of cold front surging south. Right now thinking the chase target near Sayre/Elk city looks to be a good starting spot. So plan on heading that direction here in the next hour or so.

I'll have another update later while I'm on the road. Unfortunately this looks like a possible day of if there will be a tornado but how many and if they will hit anything.

Here is the latest SPC Outlook and the second map is the tornado threat with a large 15% area.

Friday, April 24, 2009

Storm Season Is About To Arrive

Buckle those seats belts because Tornado Alley is about to live up to its name. A very favorable pattern is taking shape for repeated bouts of severe weather across the Central and Southern Plains. Reading special statements from Local NWS offices and the SPC office. They all notice and mention that climatology is on the side of major severe weather outbreaks with the upcoming pattern.

As a trough digs into the interior West a strong Ridge has developed across the East. Which is a blessing for everyone wondering if Spring was ever going to arrive east of the Mississippi River. Temperatures will likely soar well above average in parts of the East into the weekend. This has allowed the Gulf of Mexico to recover the warmth and moisture. That was continuing to be scoured out by strong cold front in the northwest flow we were in. Now that the pattern has changed deep moisture has been able to pool and now is surging north. Dewpoint levels have gone into low 60s well into Kansas. As the depth of the moisture is now above the 850mb throughout Eastern Texas. This is very key as when its not very deep the dewpoint may be 60 in the morning but by afternoon. The air has mixed, heated and dried so the dewpoint temperature may only be 51. Moisture is very key for storm development and especially tornadic development.
Going back to our stormy pattern evolution, the trough in the West will only slowly move east. In which in a southwest to northeast flow right over the Plains. It will send pieces of energy or little shortwaves out. Each one of these can and more and likely will produce severe weather starting Saturday. The SPC has already placed parts of Oklahoma, Kansas and northeastward to Chicago in a slight risk. The greatest threat will be in parts of southern Kansas and western Oklahoma. Where very large hail and tornadoes will be possible. Current parameters produce moderate to strong shear, moderate helicity and moderate to high CAPE (nearing 3,500 joules). The cap or lid on the atmosphere will likely only allow a few supercells to form by Saturday evening. More widespread storms will along the cold front from Kansas northeast to Southern Lower Michigan.
Beyond Saturday, a even strong s/w comes out into the Plains by Sunday evening. This will likely cause more widespread severe weather across the area. This just the start as the models so the entire week of short wave after short wave as the pattern doesn't really change. Looking even farther down the road the overall pattern will some changes from time to time looks the same till mid May. So if this comes true last years very dosial storm season here in Texoma will all but the past. As I will likely be a very tired person but will likely have some very cool shots of wicked supercells and some nice tubes.
Chase Mode: Yellow(Chase is likely)
My plans currently are to be along I-40 at the Oklahoma/Texas Panhandle border at around 4pm. As models showing storms going up at or just north of I-40 by 5:30pm. I'll likely put together a analysis together tomorrow morning. As things will really come together in the next 24 hours.

Current SPC outlook for Saturday and Sunday


My Current Day 2 Chase Map with target area.

Thanks for Reading, I'll keep ya posted...

Monday, April 13, 2009

I'm Back with a review of winter and look ahead to Summer

Sorry for not posting in the last couple of weeks. As I have had some issues with the website, very busy schedule and reformatting the website. So here is the decision I have come to about this website. First in foremost its a way to post my chasing adventures and any other pictures I take. Second I will continue to post medium and long range for the United States. Third I will give short term 1-3 days out forecast for severe weather events. What will be limited is trying to post current day events. As I haven't had the feedback I was hoping from people checking the site or seen a big increase in viewers. Plus this site was originally developed to share my chase adventures and give you heads up to big events.

Alright now to what has seemed the never ending end to winter. Which if you remember I mentioned that it we would have a late spring, especially in the east. ( patting myself on the back..haha). Here is the Temperature and Precipitation means from Average for the Month Jan-Mar.)


More in depth look at the Winter of 2008-2009

So you say what is next on the ole weather agenda? Well the split flow we're in with the main jet stream split across the U.S. is about to end. The map below is the 500mb height mean anomaly which shows if the temperatures at the 500mb heights are cooler or warmer than average. The split flow with bowling ball storms and shortwaves are pretty common in late spring of La Nina years. Last year this also occurred but was a little later in the spring in May. Which caused lots of tornadoes in the central plains and into the Mississippi Valley. This year since its April and the southern jetstream has kept the really moist tropical air south of the Storm track. So the tornado number is about on average, based on the storminess across the country you would think it would be a lot higher.

Alright back to the 500mb map, if you look into central and eastern Canada there is a lot of warmer heights which is acting like a block. So any cold air that builds across Western Canada comes straight southeast into the Eastern United States. So although its cold over this weekend and early next week. The winter pattern is saying goodbye as a major warm up takes over for the entire U.S.. This will send temperatures into the 70s and 80s into the Great Lakes, Ohio Valley and entire east coast by next weekend. If you look at the 500mb maps below you can see by the end of the month the blocking disappears. We get into a more west to east flow with warmer heights below and cooler ones up north. This will also turn off the rainy and stormy pattern over the East.


So say hello to Summer finally over the East as the nasty late winter pattern is finally saying goodbye. This is however with one last gasp of bitterly cold rain and some snow over the Great Lakes, Ohio Valley and Northeast. Here is a look at the Climate Prediction Center to the next 6-10 days... Can you say hello Summer!