University of Kentucky Agricultural Weather Center Serving Kentucky residents

On the World Wide Web at: http://weather.uky.edu/

Mouseover to pause!......Kentucky Short-term forecast... ...The mission of the UK Agricultural Weather Program/Center is to provide educational resources through the development of agricultural weather products and services that minimize weather surprise to Kentucky residents relative to their agricultural needs... Detailed forecast information is available in your Precision Ag Weather forecast here... -=-=-=-=-=-=-=--=-=-=-=-=-=-=-=- Long-range outlooks here. Where is Spring? The new spring season officially started at 7:02 on the 20th, but more than anything, it felt like the middle of January. This past month has been extremely cool with a state average temperature of 4 degrees below normal through March 20th. Just this past 3 days (3/18 – 3/20), highs have been averaging a very cool, 9 degrees below normal statewide, with lows following suit at 4 degrees below normal. Average highs across the state for this time of the year are suppose to be in the upper 50s to low 60s with lows only dropping into the upper 30s. The rest of the month doesn't look any better. This upcoming week will feature highs staying mostly in the 40s across the state. The short term outlooks don't provide any hints at spring either. The 6 to 10 day outlook going out to March 30th, as shown to the right, has well below normal temperatures expected for the Commonwealth. So what is causing this cool pattern? Although we can look at local weather conditions for an answer, looking at a larger spatial scale is also required. Over the past month, the eastern portion of the country has been locked into the negative phase of the Arctic (AO) and North Atlantic (NAO) Oscillations. Similar to El Nino/La Nina, these oscillations also play a large role influencing the weather patterns across the globe. The North Atlantic Oscillation is dependent upon pressure patterns in you guessed it, the North Atlantic. These patterns play a large role in winter weather across the Eastern United States. Currently the NAO is in a negative phase, which means a “blocking pattern” has setup in which a ridge of high pressure acts to keep an enhanced trough of low pressure over the Eastern United States. This results in much cooler temperatures, as the Bluegrass State is more susceptible to Canadian or even Arctic outbreaks. The Arctic Oscillation, on the other hand, is located in the Northern Polar Regions. This oscillation is affected by the large scale difference in temperatures between this region and the equator. This difference has an affect on large scale wind patterns. Currently, the oscillation is in a negative mode. This results in a weakening of the polar low pressure system, which allows for much weaker winds aloft. Much colder air and more Arctic outbreaks are common during this period across the Eastern United States. Both of the above oscillations have been in a negative mode for the entire month of March, providing very cool conditions across the Eastern United States, including the Commonwealth. Luckily, these oscillations can change over the course of weeks, and with other subtle hints, the end may be in sight. The negative mode can be shown in the charts to the left, and as indicated by the “red” forecasts, each oscillation is expected to make a run toward positive going into early April. A positive mode would indicate a return to above normal temperatures. The great news that came out recently (3/21/2013) is the fact of outlooks trending toward above normal temperatures in both April (shown to the right) and the 3 month outlook out to June. This is a welcoming sign as the Commonwealth gets further established into the planting season and horticultural crops having already been delayed. While temperatures will remain cool through the end of March, it is expected Kentucky will also continue in an unsettled and wet weather pattern. Since the start of March, the Commonwealth has averaged nearly 4 inches of rainfall, which is about an inch above normal. This has just added to our already wet winter season where Kentucky were 2.57 inches above normal over the course of December and January. The wet pattern looks to continue this upcoming weekend and on into April. The 5 day rainfall outlook through early next week is predicting anywhere from another half to one inch falling across the area. The latest one month outlook for April is also suggesting above normal precipitation. This is in addition to above normal precipitation expected the next 3 months into June. In summary, the upcoming planting season looks to resemble years past. In typical Ohio Valley fashion, the weather pattern will throw another curveball at the planting season. While well below normal temperatures and wet conditions will continue to postpone field operations through the end of March, a warm up is expected going into early April. More information on your specific farm's forecast through the next 7 day's can be found here or more information on the outlooks here. A more in depth perspective of oscillations across the globe can be found here.

Ag Weather Center, Department of Biosystems & Agricultural Engineering, University of Kentucky