Lead Forecaster: Alex Woolum Email: firstname.lastname@example.org
on Sunday, April
Technical Forecast Discussion
Short Term Discussion (Monday 4/24, through, Tuesday 4/25)
An upper-level SW trough (300-200mb) has closed itself off over western Tennessee and Kentucky. Surface fronts have been weak over today (Sunday), but as this system transitions into a more negative tilt they gain some strength (especially the cold front from (surface-850mb). The warm conveyor belt gains a great amount of strength over the Atlantic, which is a big reason why we are still seeing so much moisture in our area. But a secondary lower level low pressure system, over northern Minnesota Tuesday evening, is going to help advect/pull much of the moisture currently moving westerly from the Atlantic ocean towards the mid-Atlantic US, much more north. Northeastern States are going to receive a strong plum of moisture and convection (looking at precipitation accumulation around 1.5-2.5" on the GFS from Boston, up the eastern coast of Maine. Luckily the precipitation accumulation product shows Athens Ohio being on the border line of no rain and 0.10-0.20" of rainfall, all the way through Tuesday. Soundings during the day Monday are a lot more organized (with directional shear, and a little speed shear; but they both are still on the very low end in their value of strength) than Tuesday, however they are both lacking a ton of the necessary ingredients to produce and Thunderstorms and/or heavy rain showers. Especially from the surface to the lower ~1km of our troposphere being so dry throughout the days and evening.
Long Term Discussion (Wednesday 4/26, through, Friday 4/28)
Wednesday lower-level high pressure will dominate most the day, and dominate into early Thursday. 850mb temperatures top off around 15C before sunset, while surface temperatures on GFS and Euro max out in the lower-mid 80's. However a new upper-level LW trough is beginning to tilt negatively over the western United States, into the eastern part of the United States. The jet streak moving upstream on this trough will tilt it's right entrance region over the southeastern Ohio region, 15-21Z Thursday. PVA values on the 500mb layer move into the southeastern Ohio valley region 21Z Thursday, with values around 10-15s^-1. The core values with this PVA remain in the NW part of Ohio, with values around 30-35s^-1. Isobars converge over eastern Indian, up through NW Ohio, with some wind speeds on the 850mb layer reaching up to 60 knots. Which is quite strong for the 850mb layer. There is a small convergence of isotherms over central Kentucky, moving into southern Ohio at 12Z Thursday, indicating potential for strong WAA in the morning. Soundings during Thursday evening, into most the evening, show good potential for light rain showers with the strong speed and directional wind shear. However the hodograph does show a bit of backing, which could prevent rain showers form sparking up. CAPE is on the low end so definitely no strong thunderstorms. Thursday evening into Friday is when we start to see moderately cold air sink back into the southern Ohio region, but not for long because of strong southwesterly WAA out of the Texas region Friday night, through most of the weekend. RH% from 925-850mb remain around 40-60% over our region this weekend, indicating potential for rain showers and for sure partly-mostly overcast skies.