Today, if you believe the local WRF model of choice, not much. Most of the heavy stuff in the first wave is going to skirt just to our west, with the Cattaraugus and Gowanda areas being grazed by some light showers. The rest of the area is likely to see cloudy skies, and a temperature well above average for mid-September, in the mid- to perhaps even upper 70s this afternoon.

Tonight, on the other hand, looks more promising. Another wave of showers will continue to work its way up the Appalachians, and in a more favorable convective environment, will provide some widespread rain, something we could use, as we haven’t had much since that lake-effect event back at the end of August. We could easily see a quarter to half an inch out of it. Temperatures probably won’t drop as much, though: early-morning “lows” won’t even drop past 60.

The rain will continue into Tuesday, and will last for most of the day. Temperatures will be slightly cooler, in the low 70s. The next challenge for the forecast is when the rain exits. The models are apparently diverging on this issue… I say it’ll start drying out by Tuesday night, which will be mostly cloudy with lows still very warm, in the upper 60s.

Wednesday, partly sunny skies can be expected, and continued warm weather, with the afternoon highs peaking in the mid-70s again.

Tonight, temperatures should drop into the mid-40s.

For Friday, a weak cold front to our north should barely miss us and scoot over to our east as it gets squeezed out of our way by continuing high pressure over the Appalachians and the Great Plains. Temperatures will remain in the 60s with mostly sunny skies. (After all the rain we had this summer, it’s been awfully dry the past few weeks…)

For perspective, the average high for the Twin Tiers today is about 68, falling at a climatologically rapid pace of 1 degree every 3 days.

A beautiful forecast ahead… tomorrow, in the Weekend Outlook.

~Jerry

There’s a major divergence in the temperature forecasts in the models today. 850-mb temps are expected to be in the 16 C to 17 C range. If this were clear weather, that means we’d be experiencing mid-80s this afternoon. GFS MOS is leaning more toward this solution. NAM MOS is calling for much cooler temperatures in the mid-70s. Both are predicting about 50% chance of precip between 8 a.m. and 8 p.m. today. Looking at the WRF, that model does not favor any precipitation affecting us today, and seeing the radar-satellite composite, the warm sector of this system appears to have developed a dry slot, so I will lean toward the high end and forecast a high temperature of circa 80 for the Twin Tiers, with a mostly dry day. There is a slight possibility of some pop-up convective rain cells, but I don’t see this as as much of a threat as others may. With dew points very high, it will be a warm and sticky night, with temperatures in the upper 60s to perhaps in the low 70s as we approach tomorrow morning.

Tomorrow… here’s where things get really interesting. The jet stream-associated cold front I was talking about last week is finally approaching. (Oddly enough, the Weather Service hadn’t even mentioned it until today.) For Friday, the area is expected to be under the right-rear quadrant of the jet, and with the air loaded with Gulf moisture ahead of the cold front, and some significant surface convergence, this storm has the potential to bring some prolonged, heavy rain for Friday. Temperatures, and this is just a stab, will likely be in the upper 70s.

I’ll have a more thorough forecast for the Blazin’ Cruise and everything else going on this weekend here in Little Valley on Saturday morning, but right now, expect low 70s and cloudy skies, with not much threat of rain for Saturday. Most of the heavy stuff is expected to be east of the area, with some possible influence from Hurricane Bill.

~Jerry

Just a reminder; an Air Quality Alert remains in effect for Cattaraugus County for today. Low-level ozone is forecast to be at levels considered unhealthy for sensitive groups, such as elderly, those with asthma or the like, and young children. Urban areas (e.g. Buffalo) are more likely to have these elevated ozone levels than rural areas like ours.

Humid air to our west, as it slowly works its way inward, will keep tonight’s temperatures well into the mid- to upper-60s. Fog can be expected.

Tomorrow, things begin to get interesting. If you recall my last discussion, I mentioned that out in the midwest a cold front associated with the jet stream was threatening. Well, the jet stream hasn’t moved very much, but that cold front is still approaching. According to the WRF model run at the NWS, the first line of showers is scheduled to approach us Tuesday morning, but it’ll fizzle out by the time it reaches McKean and Cattaraugus Counties. More showers will come later in the afternoon and evening hours. Temperatures should reach the low 80s for afternoon highs.

Because the jet stream is still well to our northwest, the cold front won’t pack as much punch as it had originally appeared, and high temperatures for Wednesday should be in a seasonable mid-to upper 70s range. The next round of rain moves in Thursday… but I’ll get to that in my next discussion.

~Jerry

There isn’t much to say about the next few days’ weather: 850-mb “mile-up temps” will be in the mid-teens Centigrade, providing for afternoon highs in the mid- 80s on Friday, mid-to-upper 80s on Saturday, and possibly flirting with 90 on Sunday (though I’m not quite ready to call for it to hit 90 just yet).

Early-morning lows will likely hover in the low 60s, which is normal for this time of year (in contrast to the highs, which are several degrees above normal).

The next threat to our summer isn’t for another several days, outside our regular forecast window. Currently over Idaho and Montana is the only significant surface trough (low pressure) on the continent right now. The problem is that it’s associated with the jet stream, which means it brings the potential to significantly cool down our weather. So far, the models have it stalling over us for a few days and giving us more rain while the cooler air stays to our north. That, however, is still way out into the future.

~Jerry