|Dew Point:||65.1°F (18.4°C)|
|Wind:||From the ESE at 2.7 MPH|
|Sea Level Pressure:||26.50" (897.3 mb)|
Chance Showers And ThunderstormsHigh: 74 Low: 56
Scattered Rain ShowersHigh: 70 Low: 58
Chance Rain ShowersHigh: 75 Low: 63
Chance Showers And Thunderstorms then Showers And Thunderstorms LikelyHigh: 77 Low: 65
Slight Chance Showers And Thunderstorms then Mostly SunnyHigh: 78 Low: 63
A chance of showers and thunderstorms before 2pm, then scattered showers and thunderstorms. Mostly cloudy, with a high near 74. West wind 14 to 18 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
Scattered showers and thunderstorms before 7pm, then a chance of showers and thunderstorms. Mostly cloudy, with a low around 56. West wind 16 to 20 mph, with gusts as high as 30 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Scattered rain showers before 4pm. Partly sunny, with a high near 70. Northwest wind 13 to 16 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.
A chance of rain showers after 1am. Partly cloudy, with a low around 58. Northwest wind 3 to 13 mph. Chance of precipitation is 30%. New rainfall amounts less than a tenth of an inch possible.
A chance of rain showers before 2pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 75. Northwest wind 3 to 7 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.
A chance of showers and thunderstorms before 8pm, then a chance of showers and thunderstorms. Mostly cloudy, with a low around 63. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
A chance of showers and thunderstorms before 9am, then showers and thunderstorms likely between 9am and 1pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 77. Chance of precipitation is 60%.
A chance of showers and thunderstorms. Mostly cloudy, with a low around 65. Chance of precipitation is 40%.
A slight chance of showers and thunderstorms before 10am. Mostly sunny, with a high near 78.
... An upper level disturbance and surface cold front cross later today into tonight. Warm front moves through early this weekend. Cold front early next week.
NEAR TERM /THROUGH TONIGHT/... As of 950 AM Thursday...
Updated POPs today based on recent hi-res model runs. Mainly to add in higher POPs for the decaying area of showers and storms moving in from the southwest. And then also tried to tighten up the gradient on POPs this afternoon as the cold front approaches from the west.
As of 430 AM Thursday...
A broken, weakening band of showers crossing the forecast area from west to east early this morning, was what remained of convection last evening out ahead of a cold front out to the west, and represented the eastern edge of a cool pool in its wake, over the middle Ohio Valley. These showers will likely weaken further and fall apart as they move east early this morning, in tandem with a short wave trough out ahead of the main short wave driving the cold front out to the west.
In the meantime, showers and thunderstorms were forming along the southwestern edge of the cool pool, over south central to southeastern KY and north central to northeastern TN. This area is likely to increase in area coverage early this morning, on the nocturnal theta e feed into the cool pool, from the west- southwest at about 40 kts at h85. This convection will likely weaken as it moves into the area later this morning, on cloud top warming and mixing through of the low level jet.
The NAM12 solution of a convection feed back low of around 1000 mb this morning is dismissed, along with similar solutions over the past few days of a 996 mb low crossing the upper Ohio Valley. Rather, an existing low near 999 mb over northwest IN early this morning, will scoot across northern Ohio this morning, and north central PA later this afternoon and this evening. The surface cold front, extending southwestward from the low center and entering western IN early this morning, will cross IN, OH and KY today, and WV this evening.
Convection will fire up ahead of the advancing cold front, most likely beneath forcing out ahead of the main short wave trough, which was digging into lower Mississippi Valley early this morning. That forcing will traverse the TN Valley this morning, before moving northeast across WV this afternoon. As such, convection later this morning and this afternoon is most likely to fire mainly east of the Ohio River, and so that is where PoPs are highest.
As the cool pool erodes and moves east today, CAPE is progged to climb only to 1000-1500 J/kg this afternoon over the middle Ohio Valley, even less over the central Appalachians, where the cool pool crosses this morning. However, that is where the best forcing and bulk shear are progged, as the short wave trough lifts out of the TN valley. Thus, the thunderstorm strength potential is muddled today, with a marginal risk east of the Ohio River depicted by SPC, and just general thunderstorms forecast in the weaker shear and forcing over the middle Ohio Valley. However, taller thunderstorms today could turn out stronger farther west, given the greater CAPE there, and the proximity of the advancing cold front.
PW values remain up around 1.75 inches across much of the area today, amid areas of low FFG values, and the Flash Flood Watch continues through this evening, as any thunderstorms can easily produce excessive rainfall. Instantaneous rates of 3-5 inches per hour were not uncommon with the heavier thunderstorms last evening, amd there were some reports of minor flash flooding where such storms persisted or redeveloped.
Where mixing is realized today, downward transfer increased momentum aloft can result in gusty winds even outside of thunderstorms.
The cold front crosses tonight, followed by a lowering stratocu deck, along with light rain showers in and near the mountains. Mixing behind the front will result in gusty winds tonight, which will then gradually start to wane overnight.
Near term central blends closest to bias corrected guidance and close to previous forecast for temperatures and dew points, with highs today limited by the cool pool, and a slightly cooler and less humid Friday morning on tap, in the wake of the cold front.
SHORT TERM /FRIDAY THROUGH SUNDAY/... As of 305 AM Thursday...
A warm front marks the return of higher humidity through the column after a brief stint in a low POP forecast. Looking at the thicknesses and layer moisture, the warm front will make only slow progress through the CWA Friday through Saturday. The upper level flow will be nearly parallel to this warm front, so there will be a possibility of convection running southeastward along the boundary Friday night and Saturday night. Even though the warm front should make a full push through the region, the northwest flow aloft looks somewhat active for the duration of the short term after Friday, particularly for the western CWA. The rises in the 500mb heights will signal a modest warm up that will be affected by clouds and convection, but temperatures should end up slightly above normal for the max values this weekend. The standard threats for downpours and some gusty winds in storms will be present.
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... As of 305 AM Thursday...
The upper level pattern becomes progressive again, with the ridge passing early next week and the next trough axis in line behind it. Expect frontal passage right now in the late Monday night/Tuesday time frame, and will of course need to watch the convective threats for as it does so. Some discrepancies in the long term models give a lower confidence for this timing.