This evening, a deep upper level vortex is located just north of Lake Superior, with a strong jet segment extending from Northeast Montana to the Midwest. A weak ridge is found over New Mexico and Colorado and another storm system is moving onshore Northern California. By Monday morning the Western U.S. system will be centered near Reno, Nevada. It will track steadily eastward and be located just north of the Four Corners by Tuesday morning. By Wednesday morning, the system will be located near the Colorado/Kansas border. The short wave trough will be dragging across Oklahoma during the overnight hours of Wednesday into Thursday.
It will be mild across the state tonight before a cold front enters Northern Oklahoma around daybreak on Monday. This front will slow its southward progress reaching only to near the I-40 corridor by mid-afternoon. Warm temperatures will be found over Southern Oklahoma Monday with temperatures 15 to 20 degrees cooler near the Kansas border. The front will slowly settle southward into Southern Oklahoma by Tuesday morning. Most of the state will see cooler than normal temperatures on Tuesday with brisk east northeast winds. By Wednesday morning, temperatures are expected to drop into the 30′s over Northern Oklahoma. Temperatures statewide are expected to remain well below normal on Wednesday.
Lifting will steadily increase across the region with the approach of the Western U.S. system. Thunderstorms are expected to develop Monday afternoon over the Texas Panhandle. These storms have the potential to become marginally severe and affect Southwest Oklahoma by evening. Meanwhile, other showers and thunderstorms will form across the rest of the state through Tuesday morning. Tuesday and Tuesday night stand a good chance of being wet across most all of the state. Cool mid-level temperatures may allow for a rain/snow mix at times across the northern half of the state. No significant accumulations are expected. By Wednesday morning, precipitation will start to end from northwest to southeast. By Wednesday evening, any remaining precipitation should be limited to Southeast Oklahoma.
Monday morning: 45
Tuesday morning: 39 / Showers and thunderstorms
Tuesday: 44 / Showers and thunderstorms
Wednesday morning: 37 / Showers and thunderstorms
Wednesday: 43 / Showers
Numerous severe thunderstorms formed in Central Oklahoma on the 29th. There were early day storms which produced some marginally severe hail, and more intense storms during the afternoon and evening which produced some very large hail. Hail approached baseball size in Canadian County. For Okarche, the strongest storms just missed the town with only 0.06 of an inch of rain falling.
Evening storms northeast of El Reno.
Canadian County hail reports.
A short wave trough embedded in west northwest flow will track across Oklahoma on Friday. An east/west surface boundary will lie roughly near the I-40 corridor by mid-afternoon. Low level moisture is expected to slowly increase with seasonably elevated surface dewpoints ranging from 53 to 58 across the state. Combined with steep mid level lapse rates, the atmosphere will become moderately unstable over Eastern Oklahoma and very unstable over Western Oklahoma where MLCAPE may exceed 2000 j/kg. There has been a consistent signal among model data suggesting storms may form in Central Oklahoma during the afternoon hours. These are expected to be slightly elevated, but capable of producing some marginally severe hail given the degree of instability and 0-6 km shear in excess of 45 knots. These storms would move toward Southeast Oklahoma by evening.
By late afternoon, thunderstorms are expected to form near surface boundaries over the Eastern Texas Panhandle and far Western Oklahoma. Given the fairly high MLCAPE and modest shear, updrafts should be aggressive enough to support an isolated large hail and damaging wind threat. Should surface based storms be able to organize near or north of the east/west boundary, they would be able to take advantage of backed low level flow, increasing the risk of a tornado event. While it is felt that the probability of a tornado is very low, it cannot be considered zero.
There will be a chance of severe storms on Saturday as well across the state as deeper low level moisture results in a more expansive area of greater instability.
Through Friday, upper level low pressure will be found over the Northeast U.S. with a broad, weak ridge over the west. Moderate west northwest flow will be found over the Plains. A strong short wave trough will be swinging southeastward out of Canada on Saturday and a much stronger trough will be moving into the Northern Plains on Sunday.
A weak surface front will be nearly stationary in the vicinity of Southern Kansas and Northern Oklahoma through Sunday. By Saturday evening, this boundary is expected to make a push southeastward through the state. The proximity of the front, a trough of low pressure in the panhandles and a slow but steady increase in low level moisture, will result in widely scattered to scattered areas of showers and thunderstorms. The most likely period for this to occur will be on Friday and Saturday. Some places may see precipitation as early as Thursday evening, and precipitation may linger across Southeast Oklahoma as late as Sunday. While no organized severe weather events are likely, the atmosphere on Friday and Saturday is expected to become sufficiently unstable to support vigorous convection at times. With modest shear profiles, a few isolated severe events would not be out of the question.
As the front pushes through the state Saturday night and early Sunday morning, winds will become a bit gusty out of the northeast.
Overall, temperatures from Thursday through Sunday will be mild, falling a few degrees either side of normal.
Beyond this outlook period, a very strong cold front is expected to move southward through Oklahoma on Monday. Very windy conditions, and cold temperatures will spill into the state with more freezing temperatures likely Monday and Tuesday nights.
Thursday morning: 42
Thursday: 69 / Showers
Friday morning: 53 / Showers and thunderstorms
Friday: 66 / Showers and thunderstorms
Saturday morning: 53 / Showers and thunderstorms
Saturday: 68 / Showers and thunderstorms
Sunday morning: 47 / Showers
A surface high pressure ridge will continue to move away from Oklahoma during the day on Wednesday. Meanwhile, low pressure will organize over the Texas Panhandle. A strong pressure gradient will exist over the state during the morning and afternoon resulting in south winds which will gust to over 35 mph at times. A significant decrease in wind speeds will occur by sunset.
…and then it’s time to put this one to bed. While disappointing visually, Comet PanSTARRS did give astro-photographers plenty of opportunities. I had my Moon conjunction scene, my cityscape, and now my rural scene. It was good practice for future comets and worth the effort since I’m not likely to be alive when this one comes around again in about 11,000 years.
The weather pattern will be a relatively quiet one through mid-week with upper level low pressure over the Northeast U.S. and a building, broad, low-amplitude ridge over the Rockies and far west.
A large ridge of high pressure (and unseasonably cold temperatures) at the surface will extend from the Dakota’s southward into Texas on Monday. This ridge will shift eastward on Tuesday allowing for south winds to return across the Panhandle and far Western Oklahoma. As the ridge shifts farther to the east on Wednesday, winds will return from the south across all of the state and it will become quite breezy. Any moisture return and an increase in precipitation chances will hold off until after Wednesday.
Low humidity and gusty south winds will lead to an increased risk of wildfires across Western Oklahoma on Wednesday.
Monday morning: 24
Tuesday morning: 22
Wednesday morning: 32
The system which moved through overnight produced some accumulating snow which was evident on morning satellite images. Some of the higher snow amounts included 2 inches at Freedom and Ponca City. In Okarche, only a trace of snow was observed which fell between Midnight and 1 am.
I didn’t expect to be addressing snow potential as we move into the last week of March. Most of the previous forecast reasoning remains on track. There is a consensus among morning model guidance to track the approaching storm system just a little farther south tonight. With that, there is growing confidence that accumulating snow will fall across Northwest Oklahoma. There is a slightly higher level of confidence that there will be accumulations as far south as I-40. Should an inch of snow be able to fall in Okarche, it would be the latest one inch snow on record. The record is currently March 22, 2006. Wind will still be a problem for much of Oklahoma through Sunday with the strongest gusts (in excess of 50 mph) possible over Southwest Oklahoma tonight.
A strong upper storm system is moving southeastward over the Pacific Northwest this afternoon. This system will drop into Colorado by late morning on Saturday, then track across Oklahoma and Kansas during the late evening hours and into the morning hours of Sunday. A cool airmass will remain over Oklahoma tonight as surface low pressure organizes near the western end of the Panhandle. This surface low will develop/track east southeastward across North Texas on Saturday afternoon. By mid-afternoon, a strong pressure gradient will evolve over the Panhandle in the wake of the surface low. Winds will become strong out of the north at speeds of 30 to 35 mph with gusts over 50 mph. These strong winds will reach Western Oklahoma by sunset. During the overnight hours, northwest winds of 20 to 25 mph with gusts to 35 mph will be felt across most of the state. These windy conditions will continue past Noon on Sunday. With regard to precipitation, widely scattered areas of light rain will be possible tonight and Saturday across most of the state. As cold air spills in behind the low pressure area, some snow will be possible over northern sections of Oklahoma. All precipitation accumulations are expected to be light.