High pressure coming from central Canada is well on its way into the area early this morning as I type this. The good news is that it will keep our weather dry for the next few days, effectively blocking the low pressure and rain systems from coming up from the south, and also establishing easterly flow to prevent lake effect from hitting us. The bad news? It’s going to be cold. The 850-mb contour map is showing an impressive temperature gradient to our south… Pittsburgh is reading -3 C, but less than 100 miles to the south of that, Cincinnati and Washington DC are reading +4 to +5 C. Sadly, we’re on the cold side, and will remain on that side for the forseeable future, barring any changes in the model forecast.

Wednesday

Though a few areas in the southwesternmost corners of McKean and Warren Counties in Pennsylvania may get grazed with some rain, the bulk of the area will be largely dry and cloudy, with some breaks of sun. Temperatures will reach into the low-to-mid-40s in the Twin Tiers,mid-to-upper 40s/8 C range in the Buffalo Niagara regions. Widespread frost, and I’d venture to say the real threat of a freeze, comes Wednesday night, with temperatures dropping into the upper 20s (-2 C) throughout the region.

For perspective, the average high temperature in the Twin Tiers area for this time of year is… brace yourselves… 58. We will be nearly 20 degrees below that over the next couple of days.

Thursday

Thursday will be even colder than Wednesday. The Twin Tiers will struggle to break 40 degrees on Thursday, with Buffalo Niagara only marginally better, in the low 40s (5 C) range. It will remain dry, with whatever showers that scraped by the portions of Pennsylvania in the forecast region well gone by then. The low temperatures will be marginally warmer… 0 C (low 30s) in Buffalo Niagara, upper 20s in the Twin Tiers, particularly well inland in places like Bradford and Wellsville.

Friday

The trend continues for Friday, but a moderate warm-up and clearing skies appear to be on the way for the weekend… more on that in the Weekend Outlook on Friday.

~Jerry

Today, mostly to completely cloudy skies will dominate the region, with cool temperatures dominating. The high will reach approximately 11 C. Lows tonight will fall into the 4 C range as a body of precipitation moves in from the northwest. There’s been some talk of snow, but the Niagara Peninsula should remain mostly wet. Precipitation amounts will likely be minimal.

It only serves to get cooler into the week, with temperatures dropping to 9 C for Tuesday. Whatever lingering precipitation there is should move out by Tuesday afternoon. Cloudy skies and a temperature hovering very close to 0 C will describe Tuesday night. Wednesday, more clouds continue and temperatures drop even further, to 8 C.

~Jerry

Friday

A warm front will progress over the area Friday, mostly in the afternoon hours, bringing with it widespread showers and more seasonable temperatures. Maximum temperatures should be in the 16-17 C range (low 60s F). The rain will mostly clear out by night with some straggling showers lasting into Saturday morning. Temperatures won’t drop all that much, dropping to about 10 C (50 F) by Saturday morning.

Saturday

Whatever is left from Friday’s rain will be out of the area by Saturday morning, leaving behind partly sunny skies and seasonable (but, compared to what we’ve experienced lately, warm) temperatures in the 18 C range (mid-60s F). 18 C is the average temperature for this time of year. Both the U.S. and Canadian weather bureaus are calling for a chance of showers on Saturday, but I’ll be bold and call for a dry day, and the majority of that threat is based on the timing of when the leftovers are going to leave (I’ll say very early). Saturday night will see minimums again in the 10 C range.

Sunday

Things marginally cool off for Sunday. Continued generally dry weather will prevail with maximum temperatures around 13 C (mid-50s F).

All in all, not a bad weekend.

~Jerry

Between yesterday and early this morning, Lake Erie has been quite active churning out lake effect rain showers in the Buffalo area. The Buffalo airport set a new daily rainfall record of 3.55″ of rain in a 24 hour period. If it was only 20 or so degrees colder, Buffalo would be buried under several feet of snow.

Back to Rochester, for Tuesday night, skies will remain mostly cloudy. A few showers off of the lake will pass by; however, nothing nearly as heavy as to what Buffalo witnessed. Lows will range from 40-45°.

Cool and cloudy conditions will continue for Wednesday. Skies will remain mostly cloudy, but a few passing rays of sunshine are likely. The best we’ll do for a high is in the mid 50s. A pesky west breeze won’t help make it feel any warmer, that’s for sure.

Currently moving northward along the windward side of the Appalachian Mountains is a warm front that is carrying with it significant moisture and precipitation. Surface convergence, combined with some decent warm air advection in the 850-hPa level, is giving a very nice recipe for some widespread rain showers. The WRF, a local model of choice, is showing a rather intense cell (over 15 mm/hr) moving just west of the Niagara Peninsula and almost hitting Hamilton square on. Niagara, however, won’t be totally spared, as follow-up showers will follow. The warm Gulf air is primed to boost temperatures up into the 25 C (77 F) range; though at the 850 level it’s 14 C (indicating maximum potential of a balmy 27 C), cloud cover, the threat of rain, and the continuing loss of daylight will begin to reduce the ability to reach that maximum temperature. Expect no less than 10 mm of rain out of this, probably significantly more.

As the area will remain under the influence of the Gulf air Monday night, expect lows to drop only into the 16 C (low 60s) range, more akin to midsummer than mid-September.

Tuesday, lingering showers will still remain, though the chance of them will diminish as time passes. Highs continue to chart well above average, with a high of 24 C (75 F) probable for Tuesday.  Tuesday night, some drying finally starts to work into the area again, with lows dropping to about 14 C (57 F)… not terribly significant of a dropoff, but the clearing skies certainly will create potential for more cooling.

Wednesday and Thursday, according to the forecast models, have negligible chances of precipitation and are still well above average for temperature, with temperatures in the 22-24 C range.

~Jerry

Friday

Friday's weather factors - 9/18

The back end of a  relatively weak cold front is creeping its way southward from Canada this afternoon. Since most of the precipitation with this particular front is on the eastward (front-end) side, it won’t affect our weather much other than some clouds.

Mostly cloudy. Slight chance of showers from Allegany County eastward. High temperatures will be in the upper 60s in the Twin Tiers, about 21 for the Niagara Region and about 70 in Buffalo.

Friday night will see skies begin to clear and will be a few degrees cooler than anything we’ve seen in a while. Those of you in the Niagara region will see low temperatures drop to about 7 C (in Buffalo, mid-40s F). The Twin Tiers will be significantly cooler, dropping into the upper 30s in some places. It will creep awfully close to potential frost temperatures, but I don’t think we’ll get quite to that point.

Saturday

A “Chamber of Commerce” weekend is in store for this weekend, as comfortable (albeit cool considering what we’re used to) air and sunny skies will dominate our weather. Sunny skies, with highs in the mid-60s in the Twin Tiers and in Buffalo, 18 C in the Niagara region.

Sunday

Sunday proves to be even better as the high pressure moves to our east and establishes some southerly flow, bumping temperatures upward. Sunny skies will persist throughout the whole area. A big bump in temperatures can be expected, into the low-to-mid-70s  for the Twin Tiers and Buffalo, and 23 in the Niagara region.

All in all, a beautiful weekend. Go out and enjoy it because Monday, things won’t be so nice.

~Jerry

Today, though, high temperatures will still reach around 24 C (mid-70s F), but likely a few hours earlier than usual, as a brisk northerly flow begins ushering in the cooler air to the Niagara Peninsula. Tonight’s overnight lows should drop to about 9 C (upper 40s F).

Tomorrow, as I stated, will remain sunny, but several degrees cooler, with highs peaking at about 20 C (upper 60s F). More moist air will move in Wednesday night, helping keep temperatures up to 14 C (upper 50s F). The good news is that the preciptation that’s associated with this is going to miss the Niagara region, according to both the GFS and the NAM (our broad-scale forecast models of choice). In other words, mostly dry, cool weather continues as temperatures peak in the 18-19 C range (mid-60s F) for Thursday.

More on the weekend in a few days in my Weekend Outlook.

~Jerry.

Friday, as the high organizes better and establishes a more southeasterly flow over the area, cooler, much more moist air will enter the region. High temperatures for tomorrow afternoon will drop into the 20 C (upper-60s F) range, by far the coolest part of the weekend. The major threat of rain will begin Friday night, though it’s not expected to be anything like a washout, more like on the order of 5 mm (0.2″). Low temperatures will remain in the 13 C ballpark Friday night and into early Saturday morning. Rain will clear out around Saturday afternoon, and temperatures will rebound fairly nicely, back up to around 23 C, as another sprawling high like the ones we’ve seen a lot of this August and September moves into the area. The result is that Saturday and Sunday will have fair skies, lows holding steady around 13 C and highs for Sunday perhaps reaching as high as 25 C (upper 70s F).

For perspective, the average temperature for this time of year is 22 C.

Well, first off, I have a little bit of crow to eat, because I held out on the side of optimism back on Friday when predicting no rain for Labor Day. As it turns out, portions of the area got rained on despite this. Fortunately, it wasn’t anything major, as our rain gauge measured less than a tenth of an inch.

Today, the prospects of rain are somewhat less. We’re under mostly cloudy skies, southerly winds, and dew points around 60, with no major body of precipitation around. The WRF is showing no real threat of convection, and the 850-mb charts are showing any warm-air advection being negligible, despite the strong surface winds. So, even though the NWS discussions are introducing a chance of convective precip, I’ll be bold and predict predominantly dry weather over the entire region. 850-mb temps will be in the 12 C range, giving potential maximum temps of 25 C (77 F). Due to a lack of sunshine, there likely won’t be the mixing necessary to reach that in most areas. So, I’ll call for mostly cloudy skies, highs in the mid-70s in the Twin Tiers, upper 70s for Buffalo and Rochester where there should be more breaks, and mid 20s for the Fort Erie-St. Catharines area.

Tonight, mostly cloudy skies continue with a low of about 60 F (15 C) in the entire forecast area.

For perspective, the average high for September 8 is 73 in Buffalo, 74 in Rochester, 70 in Little Valley, and 71 in Bradford. We should be a few degrees above that, despite the clouds.

Andrew returns tomorrow, and so also will begin the Fall Foliage Report. By the way, this forecast is a fairly important milestone for the Weather Blog… our 100th forecast. Here’s to many more to come…

~Jerry

Friday

Not much change. High pressure remains anchored over the Great Lakes today, and 850-mb temps are in the 12 C range. So, again, afternoon highs in the mid-70s can be expected, with mostly sunny skies.

Friday night will once again be mostly clear, with the omnipresent risk of fog especially in the valleys. The air is not quite as bone-dry as it has been, so expect early-morning lows to be in the low 50s. Upper 50s in the cities.

Saturday

A very weak front is expected to die out well to our northeast, which could bring some marginal cloud cover to the northern parts of the forecast area, but nothing that significant. High temperatures will once again be in the mid-70s throughout the region.

Saturday night will be almost identical to Friday, with clear skies in the cities and northern lowlands and temperatures in the upper 50s, but fog and lower 50s in the Twin Tiers valleys.

Sunday

On Sunday, the forecast begins to get interesting. The HPC prognosis for 12Z Sunday shows a body of precipitation currently over the Deep South propagating northward in a direction parallel to its axis. It is fairly uncommon for precipitation bodies to do this, especially when the steering winds at 500 mb are mostly in an easterly (and also convergent) direction, according to both the GFS and ECMWF models. (When there’s convergent air aloft, that does not usually favor well for lift, a necessary ingredient for precipitation.) In short, I’m not buying it.

Sunday should remain mostly sunny with temperatures in the mid 70s throughout the forecast region. Sunday night will be more cloudy over the whole region and have temperatures in the mid-50s throughout.

Labor Day

More clouds can be expected on Labor Day. This will also put a slight damper on our temperatures, so lower 70s can be expected. However, like I said before, I do not believe there is any significant chance of rain.

For perspective, average high temperatures for this weekend are 73-74 degrees in Buffalo, 74-75 in Rochester, and 71-72 in Little Valley and Bradford.

~Jerry