WKU Meteorology

The first day of the class started early in Tulsa, OK where the students were learning the daily rituals of the trip.  Each morning the students will conduct their own individual surface analysis and state where they would position the van for the best chance in catching storms.  Each student will work alone, but come together before leaving with the professors and explain why each of the students chose those particular spots.  After a brief forecast discussion and small debates, the selection is made and we hit the road.

Today, the target city was Wichita, KS where the class and professors both feel is the optimal spot for convection and rotating storms.  An upper level trough that is slightly negatively tilted is ejecting out of the four corners region northward.  Synoptically, that means just east and northeast of the upper level trough is where the maximum positive vorticity advection will take place along with maximum theta-e advections at the surface. At the surface, a low pressure system located near the CO/KS border will translate northward and bring the advancing warm front northward with it.  As the low translates northward, as does the warm front, winds at the surface will become from the southeast.  Which is favorable for supercellular development given that the winds are veering with height (winds turn clockwise and increase in speed with height).  Bulk shear values range from 40 to 60 knots, where 45 is a baseline value for supercellular development.  Moisture has recovered nicely from early in the week bringing dew points into the mid 60’s.  Instability is expected to increase throughout the day as the warm front advances north, leaving south of the front to clear skies for maximum surface heating.

The thought process of students and professors was to move close with the center of low pressure and advancing warm front at the surface where winds will be veered, moisture advections will be maximized, and instability will be the greatest.  Here is a surface analysis done by myself (Lee Campbell).  Blue circle indicates our target area, blue line indicates cold front, orange line indicates the dryline, red line indicates the warm front, and green lines indicate dew point values (65, 70), and dashed green lines show the fetch off the Gulf of Mexico indicative of the low level jet.

A recap of today will be posted either tonight or tomorrow morning with the best photos taken from the day. Enjoy your day and wish us luck!

Hello blog readers…
I am happy to report that our annual Fields Methods class has already embarked on our trip across the Great Plains in search of weather and greater understanding.
With any luck (and a little skill), we will be as successful as last year’s group and come back with many good pictures, memories, and learning experiences.
This years group includes: Mitchell Gaines, Nathaniel Shearer, Lee Campbell, Kate Wilson, Dustin Jordan, Olivia Payne, Lindsay Rice, as well as myself (Kyle Berry). The instructors, are the same as last year, as we are led by Dr. Joshua Durkee from here at WKU and his colleague Dr. Grady Dixon.
The next couple of weeks the blog will be very active, as there will be daily updates concerning that day’s weather, pictures, as well as our current location.
For now, we are currently in Arkansas heading for a good nights sleep in Tusla, OK. Tommorow looks to be a “chaseable” day with the target area being somewhere in central Kansas. Expect an update soon…

Highlights
– scattered showers and storms still in the forecast for Thursday
– much welcomed dry period Friday and Saturday
– another frontal system Sunday

Forecast: The frontal boundary which produced numerous rounds of
severe weather and flooding over a large portion of the south, Midwest
and east coast is now moving away. However the upper low behind this
system will still produce some afternoon showers and rumbles of
thunder with a threat for pea size hail in the afternoon. Afternoon
heating will lead to an increasing temperature gradient with height
which will promote the redevelopment of these clouds and scattered
showers in the afternoon. After sunset these will quickly end. Highs
will be in the mid to upper 60’s Thursday. For Friday and Saturday
conditions will clear for a few days with highs in the 70’s and lows
in the 50’s. Unforntauntrly by Sunday another strong frontal boundary
which could also be another slow mover will move into the region.
Rounds of heavy rainfall are very well possible from Sunday to beyond
the forecast period. parameters suggest the potential for another
squall line event as well Sunday night or Monday. Details will be
refined as needed on the hvy rain and severe threat Sunday night.
MWG

Highighlights:
– frontal boundary to remain in region throughout forecast period

– periods of thunderstorms each day with severe weather threats

– risk for flash flooding by Wednesday night

Discussion:
A frontal boundary which has been nearly stationary along the Ohio river will shift slightly northward Sunday night and Monday. Another round of showers and storms will be likely from Sunday afternoon into the overnight hours as this boundary shifts north, locally heavy rain and isolated severe storms are possible. During the day Monday isolated storms are still expected along the boundary instability present may allow a few of these to reach severe limits with a threat for gusty winds and hail. A low pressure system will enhance the coverage of showers and storms late Monday night with another threat for heavy rain( up to 1.5 inches from Sunday afternoon-Monday night)and severe weather in the form of gusty winds. Once again during the day Tuesday coverage of storms becomes more scattered with a continued isolated severe threat. A stronger low pressure system will track over the region along the boundary late Tuesday night through Wednesday night. These features will enhance the heavy rain threat and lead to a likely widespread additional 2 to locally 4 inches of rain which may result in flash flooding. In addition severe storms are possible on the leading edge of this system in the form of gusty winds and isolated tornadoes. With a almost constant threat for severe weather and likely hydrological hazards throughout the forecast period the STN will remain on alert for the foreseeable future. Further statements for severe watches and warnings, activations and flood warnings may be needed. lows will be in the 60’s with highs in the 70’s and 80’s.

Highlights
-Big Warm-up through Tues.
-Severe weather potential Tuesday Night into Wed.
-Heavy rain not out of the question Tues. night into Wed.
Forecast
As the trough that affected last weekend’s weather moves offshore, a ridge has begun to build across the south and temperatures will rebound under southerly flow with high temperatures on Monday reaching the upper 70’s. Monday Night a stray shower or thundershower cannot be ruled out as moisture continues to stream in and overnight lows only dip down into the mid 60s. The bigger story is on Tues, where temperatures will continue to climb as a surface low pressure moves out of the plains and into Missouri. The warm sector of this mid latitude cyclone is more early summerlike, as temps will climb into the upper 80’s, with abundant moisture in place. There will be a chance of rain Tues. ahead of a cold front that is forecasted to move through our region late Tues. Night into Wed. Severe weather is likely associated with this cold front; however more details will follow as this system approaches. For now, the Storm Prediction Center has placed our region under a slight risk, but this risk may be altered depending on how the system progresses.

Make sure you keep updated through Tues. on any changes.
The front should be through our area by Wed returning temperature to a more seasonable range of around the low 70’s.

Highlights

• Approaching low pressure system will bring clouds Thursday night
• Severe weather threat on Fri, with more moderate/heavy rain possible.
• Highs in mid 50’s on Saturday, returning to the 70’s by Monday.

Forecast
As convection and severe weather in Oklahoma and Missouri continue overnight, expect high clouds to start streaming into the area overnight. Lows tonight will only get down in the mid to lower 50’s under cloudy skies. Friday, conditions are favorable for thundershowers, perhaps with some severe storms later in the day. A surface low pressure system will approach our area on Friday, with winds turning out of the south-east throughout the day. This will help to bring ample moisture into the region, and bring a good chance of rain and thundershowers for Fri morning. With the approaching system, wind fields and cooler heights aloft are supportive of stronger thunderstorms for the afternoon. Because of this, the Storm Prediction Center has placed South-central Kentucky under a slight risk for severe weather Tomorrow.

However, severe potential will be limited by early morning thundershowers, with temperatures trying to rebound throughout the day. Should we get ample sunshine are severe threat would increase. Regardless, the main threat appears to be heavy rain falling on already saturated ground, with widespread 2 inch rain totals and continued river flooding is of concern.

Thunderstorms should come to an end in the late evening as a cold front associated with the aforementioned surface low crosses the region. Saturday looks to be cool and raw with rain ending in the morning and high temps struggling to reach the mid 50’s. A return to 70’s is expected by Monday.

The severe weather threat for Sunday evening / Monday morning advertised earlier this week now appears to be much smaller than initially thought. Both the GFS and the NAM have pushed back the timing of the cold frontal passage to late morning or early afternoon on Monday, and instability is expected to be very limited when the front moves through. The best dynamics associated with the system are expected to be well to our north, associated with a deep surface low and jet streak in the Great Lakes region. With this in mind, the SPC has dropped the slight risk for the area on Monday. However, the situation still bears watching for possible changes to the forecast, and a good dose of rainfall is also expected with this system.

NAM CAPE forecast for 1 PM CDT Monday, showing limited instability:

More on record high potential and severe storms in eastern Kentucky…

According to the Storm Prediction Center, the Bowling Green area has a chance of seeing severe weather each of the next 3 days. Here’s the convective outlook for tomorrow:

The severe threat tomorrow looks to be marginal. Some degree of instability is forecast to be in place along with moderate wind shear, but upper level ridging will tend to suppress widespread convection. Also, the energy that could provide lift for storms is expected to move through during the late morning to early afternoon hours, which isn’t optimal timing for severe storm formation. However, if storms can fire, they will be capable of producing some hail and strong winds.

More on this weekend’s severe threats

As expected, a large severe weather outbreak took place over the southeastern U.S. yesterday. However, it turned out to be even bigger than expected, with over 1,200 instances of severe weather reported between 7 AM CDT Monday and noon today. Most of these reports were of damaging winds associated with a huge squall line that swept across the Southeast, although 23 tornadoes were also reported. This preliminary tornado count will probably increase over the next few days as storm damage surveys throughout the affected areas differentiate between straight-line wind damage and damage caused by tornadoes.

The above map shows that damaging wind reports were widespread in Kentucky, and a few tornadoes were also reported in the state. Most notably, a tornado did significant damage to a manufacturing plant near Hopkinsville, resulting in several minor injuries. Damage surveys conducted today have also confirmed that an EF-1 tornado occurred in southern Butler County and two separate tornadoes in Ballard County, one EF-2 and one EF-1. The Bowling Green area was spared the worst of the storms. Winds gusted to around 40 mph and heavy rain fell when the squall line passed through the area, but no major damage was reported in or near the city.

For Bowling Green, today’s cooler weather will be followed by a quick warmup into the low 70s tomorrow and warm conditions throughout the rest of the week. Rain chances return to the forecast on Friday, and there is a possibility for another severe weather outbreak late this weekend. This event is still a long way out though, and the potential for severe storms will be better known later this week.

Summary:
-Severe weather possible in the early afternoon hours tomorrow
-Damaging winds currently expected to be the main threat
-Cooler temperatures tomorrow night and Tuesday

A strong upper-level trough will eject out of the Rockies tomorrow, leading to the development and intensification of a surface low pressure center in the the Upper Midwest. This will drag a strong cold front through the Bowling Green area during the early afternoon hours tomorrow. Ahead of the front, strong southerly winds will advect warm and moist air into the area, creating at least a modest amount of instability and energy for severe storms to form.

The map above shows where the Storm Prediction Center has outlined a slight risk of severe storms for tomorrow. According to the SPC, there will be a 30% chance of severe weather within 30 miles of a point in the Bowling Green area. Currently, the magnitude of this event is expected to be limited somewhat by a lack of instability and wind profiles that are expected to result in linear rather than discrete convective modes, which favor a damaging straight-line wind threat over a tornado threat. The instability is expected to be held in check by a weakening line of storms that is expected to move in during the morning hours, bringing clouds to the area and limiting heating of the boundary layer. However, if more instability develops than the models forecast and/or wind profiles turn out to be more favorable than expected, a more substantial wind and tornado threat could develop.

The images above show a model forecast sounding and hodograph from the SREF (Short Range Ensemble Forecast) for 1 PM tomorrow in Bowling Green, just before when the cold front is expected to move through. They show that very strong speed shear will be present, with winds increasing from around 10 knots at the surface to almost 60 knots at the 850 mb level. The winds will veer from southerly at the surface to southwesterly from 850 mb upward, providing good directional shear in the low levels. This favorable shear should compensate at least somewhat for the anticipated lack of instability.