For those who are interested, the KY division of emergency managers are holding there first annual weather workshop. Topics range from weather awareness and safety, to impacts of El niño Southern Oscillation’s effects on KY weather. The target audience is anywhere from emergency managers and meteorologists, to agricultural specialists. Information about the event being held today and tommorow here in Bowling Green can be found at the link below.

http://kyem.ky.gov/conferencesandworkshops/weatherworkshop2010.htm

Guest speakers include Dr. Greg Forbes from the Weather Channel, members of the National Weather Service and faculty from WKU. Everyone is invited, including prospective meteorology students as one of the talks is on programs available at ky universities.

Shortwave and resulting vorticity maxima, coupled with some jet dynamics, is allowing just enough lift for some light showers in northern KY. For Bowling green, it will be a cloudy day with skies clearing overnight. High pressure will also return tonight, that with clearing skies will allow temps to fall tonight. Todays high should reach 51 with tonight’s low reaching 35 under calm winds.

After today’s stereotypical November day temperatures will begin to moderate for the weekend as a large trough develops over the Western US, keeping the real fall weather away from South-Central Ky for the near term.

Overall .27 inches of rain fell from the frontal passage Saturday night my COCORAHS site location. Temperatures during the day warmer into the 70′s ahead of the front on Saturday. Now the front has moved through with more seasonable fall air behind it and temperatures into the 50′s. Some clearing with cooler temps will be the rule today. The models have merged on a solution for Thursday with some rain showers and temps in the 40′s. However there still some debate regarding the evolution of the Monday and Tuesday system with the GFS being very aggressive with rainfall totals, check back on Monday for more.

1. A frontal boundary is moving through today overall the ridge should lead to a weaking trend with the shower activity. The best chance for showers should be in the late afternoon and evening with light rainfall amounts. highs should be able to get close to 70 once again after a chilly start in the 40′s. Some of the showers may linger into Sunday with clearing late. with cold air advection behind the front Sunday highs should only the reach the 50′s. Continue reading →

The extremely high amplitude trough that was located over our area towards the end of last week has moved out over the Atlantic, replaced by a similarly high amplitude ridge that has brought temperatures into  the mid 70s for the past few days. While these temperatures are certainly warm, we are still well below the record values for this date. In 2002, a high amplitude ridge brought a blast of warm air from south Texas into the central plains on November 9. This air mass was then advected into the Bowling Green area, bringing with it high temperatures in the low 80s for much of the southeast — temperatures substantially higher than expected this time of year.

Will there be a cool down soon? Over the weekend, a positively tilted trough is expected to move into the area. There probably will not be enough instability in the air to create any severe weather, but a slow moving, rain intensive system is fairly likely. The GFS is currently calling for the heaviest precipitation from the associated cold front to fall in Arkansas and Mississippi; however, this does not rule out the possibility of rain next week, associated with much more seasonal weather. Due to the slow motion nature of this system, however, there is a good chance for the rain to persist for a few days.

500 mb GFS forecast, 18 UTC, November 15, 2010

On Wednesday, an overachieving storm system brought a surprise dose of rainfall to the Bowling Green area. This precipitation was associated with an upper level low and frontal boundary over the Gulf states that pumped overrunning moisture into our region, and it was not anticipated well by the models. The Mesonet station at the WKU farm measured a total of 0.35 inches of precipitation from 6:00 AM to 7:30 PM Wednesday with this event, while the NWS observing station at the airport measured 0.32 inches.

Currently, the entire eastern half of the U.S. is under the influence of a deep upper-level trough that reaches all the way down into the Gulf of Mexico. A ripple of shortwave energy embedded in this trough brought us a few light showers this morning. Over the next few days, the trough should slowly progress to the east, with an upper-level ridge moving in to take its place. This will lead to moderating temperatures, with highs near 70 expected by Monday and Tuesday.

Current 250 mb heights and wind, showing the highly meridional flow across the U.S.

With the current jet stream pattern the way it is and the expected evolution of the jet stream as projected by the NAM and GFS, cooler temperatures can be expected throughout the week, with a more winter like feel to the weather as we head toward the weekend where highs might even struggle to reach the 50s.  The expected evolution of the pattern at 250mb is for a continued high amplitude meridional pattern with a trough digging very deep over the Midwest and producing a cutoff upper level system that will progress into the Gulf of Mexico by mid week and be picked back up by the main flow heading toward the end of the week. What does that mean for us?

Continue reading →