…Tornado risk highest over southwest Oklahoma…
Satellite loops this morning show a powerful storm system moving across Arizona and New Mexico. Strong lifting associated with this storm will be spreading over the Southern Plains this afternoon and evening.
The surface weather map shows a warm front extending west to east across Texas, from just north of Abilene to just south of Dallas. Very moist air resides south of the front. This boundary should lift northward to at least the Red River this afternoon, and may lie across southern Oklahoma by late afternoon or early evening.
Thunderstorms are expected to form in a strong warm air advection regime across western Oklahoma during the morning hours. This activity will spread north and northeast through the afternoon. Some potential exists for these storms to produce marginally severe hail.
By mid-afternoon, more vigorous thunderstorm activity is expected to form along and either side of the warm front over northwest Texas and southwest Oklahoma. The atmosphere in this region will be quite moist and unstable, and forecast wind profiles show large amounts of low and deep layer shear, especially near the front. Storms forming here will have the potential to rapidly attain supercell characteristics with all severe weather hazards possible. A strong tornado or two cannot be ruled out.
As thunderstorms grow upscale in coverage by evening / spreading into central and eastern Oklahoma, the main threat will transition to wind damage and hail. While the concern for tornadoes will be highest across southwest Oklahoma, the tornado risk in Oklahoma City is not zero.
In addition to the severe weather risk, torrential rainfall from repeated storms is likely to cause some localized areas of flooding.
People across the state / especially southwest and south central Oklahoma / should review safety rules and be prepared to act should warnings be issued.
The weather will undergo some dramatic changes today. We are starting cool – in some cases, cold – across Oklahoma at daybreak this Sunday morning. The low temperature in Okarche was 38 degrees. A small but strong storm system is moving quickly toward the state. In response, surface low pressure will be organizing over the panhandles and move into northwest Oklahoma by late afternoon. Warm and moist air / currently residing across central Texas / will move rapidly northward through the afternoon hours. By mid-afternoon, the atmosphere over central and eastern Oklahoma will become quite unstable. A dryline will begin pushing eastward across western Oklahoma, and this feature will provide a focus for isolated to scattered thunderstorm development by mid to late afternoon. Given the degree of instability and very strong wind shear profiles, the storms will have the potential to organize into supercells with all facets of severe weather possible. At the current time, very large hail will be the primary threat. However, if sufficient low level moisture returns into the state, there will also be the threat of a few tornadoes. Two areas appear most capable of seeing a tornado threat during the late afternoon and evening. One is across northwest Oklahoma – near the warm front just to the east of the surface low. The second area is from roughly the Oklahoma City area southward along and either side of the I-35 corridor where moisture is likely to be deeper.
In addition to the severe thunderstorm threat, warm and dry air will be blowing into southwest Oklahoma behind the dryline, and fire danger will become very high during the afternoon.
Don’t let the calm and cool weather this morning cause you to drop your guard. Stay tuned to weather information through the day and be prepared to act should severe thunderstorms approach.
A very strong storm system will be moving northeastward from the Rockies toward the Northern Plains today. In advance of this system, a very warm and moist air mass has moved northward across Oklahoma. The Midnight temperature Christmas morning in Okarche was 56 degrees. The temperature rose to 65 degrees by 6 am – and the dew point was also 65 degrees! Strong south and southeast winds have been gusting to between 40 and 55 mph across the state. These are conditions that one would expect to find in the middle of May!
The most significant impacts from this storm system are going to remain north of the state. A deep cyclone will be tracking from western Nebraska to southeast North Dakota, bringing full scale blizzard conditions to the Dakotas. As the warm and moist air moves northward, there will be a risk of severe thunderstorms over Kansas and Nebraska.
In Oklahoma, there will also be a low end risk of severe weather this afternoon. A dryline will be moving rapidly eastward across the state today. A narrow line of thunderstorms is expected to form along this feature which will be approaching the Okarche area between 1 and 2 pm. There will be sufficient moisture and low level shear to support a couple of instances of damaging winds with the storms. In addition, any sustained area of rotation along the line would be capable of producing a brief tornado. Even outside of the thunderstorm line, winds will be quite strong across the state today with gusts to 50 mph not uncommon. As dry air moves into western Oklahoma behind the dryline, fire danger will increase to near extreme levels.
For the record…
Thunder has not been recorded in Okarche on Christmas day before.
The record high low temperature of 50 degrees would be set given the low so far this morning of 56 degrees. However, temperatures by Midnight will have fallen into the 40′s which will keep that from occurring.
Also, the record high of 74 degrees is not likely to be reached as temperatures with extensive cloud cover will top out around 70 before precipitation arrives.
All in all, it’s going to be a Christmas to remember weatherwise.
A strong upper storm system will be moving across the Plains late Monday and Tuesday. Surface low pressure will be organizing over northwest Oklahoma, and a dryline will extend southward across western Oklahoma and northwest Texas. Early morning thunderstorms are expected to form from western Kansas to western Texas as low level moisture increases on gusty south winds. These storms may be marginally severe as they spread eastward to central Kansas and central Oklahoma by late morning. Behind the initial wave of storms, the atmosphere is expected to become quite unstable by mid to late afternoon. Thunderstorms are expected to redevelop near the surface front and dryline. Given the strength of deep layer shear and instability, these storms will have the potential to rapidly become severe. Supercells with damaging winds and large hail will be possible. In addition, conditions through the lowest levels of the atmosphere are expected to become favorable for the development of a few tornadoes. The most likely area to experience severe weather will extend from northeast Kansas to north central Oklahoma. More isolated storms will be possible farther to the south to southwest Oklahoma.
There are some uncertainties with regard to how widespread severe weather will be in Oklahoma, but the potential does exist for a few significant severe weather events. Residents are advised to review severe weather safety rules and stay aware through the afternoon and evening hours.
One of the largest tornado outbreaks of record (26 tornadoes) in Oklahoma occurred on October 4, 1998:
Published: 9 AM – Friday – September 30, 2016
The weather should become much more interesting during the first week of October.
… Severe Thunderstorm Risk for Tuesday / October 4th …
A strong upper system will be making its way across the Western U.S. and the Rockies by late weekend and early next week. Model data has been remarkably consistent with regard to this system, but there have been day to day changes in the exact track, timing and strength. Despite this, confidence is high that as strong southwest flow spreads across the Plains, deep low pressure will organize over the Central and Northern High Plains by Tuesday morning. A narrow strip of moist and unstable air will spread northward in advance of a cold front and dryline. Thunderstorms are expected to develop near these surface features by early to mid afternoon. Given the degree of instability and shear, severe storms will be possible. The most likely area to see severe weather lies across western Kansas, western Oklahoma, and parts of northwest Texas. It is too early to determine storm mode and resulting hazards.
… Hurricane Matthew …
Hurricane Matthew underwent a period of rapid intensification about 520 miles east southeast of Kingston, Jamaica overnight. Maximum sustained winds are now over 100 mph, and the pressure has dropped to 971 mb. Some further intensification is possible over the next 1 to 3 days. The hurricane is expected to track west or west southwest through Saturday morning, and then turn toward the northwest and approach Jamaica by early Monday. After Monday, model data begins to diverge as the storm tracks toward the Bahamas. The western side of the track guidance suggests that there will be at least a minimal threat to Florida, and eventually the Carolina’s from Wednesday through Saturday, but any further shift to the west would bring a greater threat.
Not a radar that I get to use very often. The eye of Matthew is clearly visible from weather radar at Curacao. Curacao is a small island country just north of Venezuela.
A dryline will once again be located from western Kansas to western Texas this afternoon. The atmosphere east of the dryline is expected to become very unstable, with moderately strong low and deep layer shear. The forecast today is made somewhat complicated by an outflow boundary that will extend from the eastern Texas Panhandle to near the Red River. Ultimately, this boundary’s position this afternoon will determine the area of greatest risk. At the current time, it is expected that the boundary will intersect the dryline somewhere over the Texas Panhandle near I-40.
Rapid thunderstorm development will begin near the dryline by late afternoon. Given the strength of the instability and shear, a quick evolution to supercell storms is likely. There may very well be several mergers and splitting storms resulting in messy modes of storms, but very large hail and a few tornadoes are still likely. In Oklahoma, the greatest risk will be southwest of a line from Woodward to Frederick.
The weather pattern will be transitioning into one favorable for daily severe thunderstorms across the Plains starting on Saturday and lasting most of the upcoming week.
This Friday afternoon, an upper wave is located over the Mississippi Valley and moving east. A ridge is centered over the High Plains and a very strong upper storm has moved over the western states.
As the upper ridge shifts east, taking up an axis from central Texas to the Northern Plains Saturday afternoon, southwest flow will begin to increase over the High Plains. Low pressure will deepen over eastern Colorado and a dryline will extend from the low to western Kansas, and western Texas. Low level moisture will be quickly returning northward to the east of the dryline over the next 24 hours. With afternoon heating on Saturday, the atmosphere will become very unstable over western Kansas and Texas and adjacent areas of Oklahoma. The combination of heating, dryline convergence and subtle lifting with increasing flow aloft should be sufficient for isolated thunderstorms to form by mid to late afternoon. Forecast soundings show sufficient shear for a few supercell storms to evolve out of sustained vigorous convection and very large hail will be possible. In addition, forecast hodographs show very large low level loops which could support the development of a couple of tornadoes. While the central and eastern part of the Oklahoma Panhandle stands the greatest risk of seeing severe storms, some of the activity may move into northwest or west central Oklahoma by evening as well.
Observed weather this Monday morning has resulted in shifting the area of risk farther south. Warm and moist air has been having a difficult time moving north with the slow retreat of the cloudy and unseasonably cool temperatures that have been camped out over Oklahoma the past couple of days. It still appears that low pressure will organize over the Texas Panhandle and a cold front will be moving southeast during the afternoon and evening. The atmosphere over the panhandles and western Oklahoma will become quite unstable this afternoon and favorable shear profiles support supercell storms. How many storms form is up for debate among recent model guidance. Most suggest, not that many. However, storms that do form will have the potential to produce very large hail, damaging winds and a couple of tornadoes. By evening, a more widespread wind and hail event is likely to develop that will spread across western Oklahoma. There will continue to be an outside chance of a severe thunderstorm or two near the warm front over central and eastern Oklahoma as well.
A fairly straight forward forecast today. A strong upper wave will be digging southeastward across the Northern Plains and Midwest with the southern edge of the associated jet segment skirting the Southern Plains. A strong cold front, leading unseasonably cool air, will be approaching northwest Oklahoma during the mid to late afternoon hours. Thunderstorms are expected to develop along this front from the Texas Panhandle northeastward to southern Iowa. The atmosphere in advance of the front will be seasonably dry, but moisture will be increasing and with afternoon heating, it should become fairly unstable. Deep layer shear will be moderate to strong and favorable for organized storms. Scattered areas of damaging winds and large hail will be possible into the evening hours, with the greatest risk in Oklahoma being over western and northern sections of the state.
An upper level low over southeast Wyoming will be lifting north and weakening today. However, a strong short wave trough will swing east around the south side of the low, tracking across the Central and Southern Plains this Monday afternoon. A sub-1000mb surface low will be found over western Kansas, with a combination of fronts and a dryline extending to the eastern Plains.
A large complex of showers and thunderstorms is found across northern Texas and eastern Oklahoma this morning. This complex will likely have an impact on moisture return through at least the early afternoon. Most model guidance suggests that this area of storms will move east into Arkansas and Missouri during the afternoon hours, with moisture returning behind it from northeast Texas to eastern Kansas. With sunshine in the wake of the morning complex, the atmosphere will become very unstable by mid-afternoon to the east of the dryline.
A redevelopment of thunderstorms will occur from eastern Nebraska to eastern Texas. Moderate to strong instability, combined with moderately strong deep layer shear will result in vigorous afternoon and evening storms with some supercell potential.
Depending on the exact position of the dryline at the time of storm initiation, storms could form as far west as the I-35 corridor. The activity will move quickly eastward with the main threat through this evening across eastern Oklahoma.