Wednesday: Mostly cloudy. Afternoon highs in the low-to-mid-80s.

Thursday: Some spotty convective thunderstorms possible, particularly in Pennsylvania, with scattered light rain showers elsewhere. Early low temperatures in the low 60s; afternoon highs in the mid-80s.

Friday: Some spotty convective thunderstorms possible, particularly in Pennsylvania, with scattered light rain showers elsewhere. Early low temperatures in the low 60s; afternoon highs in the mid-80s.

Saturday: Drier; mix of sun and clouds. Early low temperatures in the low 60s; afternoon highs in the mid-80s.

Sunday through Tuesday: The models are in general agreement that a cold front is coming. It’s not a particularly strong front as far as temperatures (don’t worry, winter isn’t coming yet); in fact, temperatures will only drop into the upper 70s at the lowest for highs, and the cooldown should help stabilize the atmosphere after Monday. Sunday, however, people in the region can expect some heavier rain to come through, and highs in the low 80s. The MOS ensemble is in strong consensus that by next Wednesday, high temperatures could be as low as the low-to-mid-70s, a welcome relief from the warm and sticky summer the region has experienced so far.

I’m cutting short at 8 days today. Yeah, I know, I usually do 10– so sue me.

~J.M. Fuller

Tuesday: Mostly sunny. High temperatures in the upper 70s.

Wednesday: Mostly sunny, slightly warmer. Early low temperatures in the upper 50s, slightly cooler in the valleys. High temperatures in the low 80s.

Thursday: Rain in the  overnight; clouds and sun by daylight. Lows in the low 60s. Highs in the mid-70s. Lows heading into Friday morning in the low 50s.

Friday through Monday: Friday and Saturday look to be dry, mostly sunny and comparatively cool. Afternoon highs for those days will likely hover around 70, possibly in the low 70s. Low temperatures will be around 50. As Cattaraugus County Fair week approaches, the models are suggesting an increased chance of precipitation but a slight bump in high temperatures into the mid-70s. This is associated with a wind shift that will bring warmer, more moist Gulf air over the region. It won’t be hot and sticky like the past couple of weeks, but it’ll raise the threat of convective thunderstorms (it does not appear to be an organized front).

Long range: GFS pushes a body of fairly (i.e. easily more than half an inch) heavy rain across the Great Plains (quite quickly) into the area on Wednesday, August 4.

Climatologically speaking: The slide begins. As I stated in a previous post, July 22 is the day of peak temperature, climatologically speaking, in Little Valley. As the days begin to get shorter and shorter, less daylight, and less direct daylight, begin to lead temperatures downward. It doesn’t begin to have significant effect until August, but as far as high temperatures go, it’s (generally) all downhill from here. We notice that with the beginning appearances of cold fronts this week. This doesn’t rule out more hot days like we’ve seen earlier this summer, but they will be fewer and farther between as August progresses.

As of midnight 7/25, the list of storm reports from the NWS can be found here.

~J. M. Fuller

Tuesday night into Wednesday: Mostly cloudy. A chance of some scattered showers in a few places, but these will likely be very sporadic. Early lows in the low 60s. Afternoon high temperatures in the upper 70s.

Thursday: Mostly cloudy for the overnight, with clouds breaking and partly sunny skies during the day. Early low temperatures in the upper 50s. Afternoon high temperatures around 80.

Friday through Monday: Rain comes in as the core of a low pressure mass moves across the northern plains and reaches the Twin Tiers on Friday. It will likely continue to bring precipitation through Saturday. The two models seem to disagree over whether or not the bulk of the rain will be on Friday (as the NAM suggests) or if a second wave of precipitation will push through on Saturday night (as the GFS suggests). Either way, the sum total of precipitation should be between 0.5″ and 1.0″. High pressure is expected to push back into the area for Sunday and Monday. In regard to temperatures, they should remain fairly steady, with low temperatures in the low 60s and high temperatures in the low 80s.

Long range: The outlook for July 27-29 looks much like the two days preceding it; high pressure will likely remain in place through that time period and temperatures will likely remain fairly steady.

~J.M. Fuller

Now, as for the Twin Tiers Ten-Day Forecast…

The National Weather Service has issued a Flash Flood Warning for portions of Allegany County around and east of Rushford, due to heavy downpours.

Tuesday: Mostly cloudy, with isolated convective thunderstorms. Afternoon highs in the upper 70s.
Wednesday: A few scattered showers possible, but unlikely, in the overnight hours, then skies clearing in the afternoon. Early lows in the low 60s. Afternoon highs in the low 80s.
Thursday: A clear, calm, cool night, followed by a hot, hazy day. Early lows in the low 50s in the valleys, upper 50s elsewhere. Afternoon highs in the upper 80s. Winds shift into a southerly direction.

Friday through Monday: GFS is forecasting a low to move well to our north but bring a weak “cold” front across the region on Friday, with the possibility of precipitation. Gulf moisture becomes the bigger threat for Saturday as a weak southwesterly flow pushes a separate body of light rain into the area. Sunday, on the other hand, should be dry, as should Monday. Low temperatures are likely to remain in the low 60s throughout the period, but high temperatures will hit the low 80s on Friday before dropping into the upper 70s from Saturday through Monday. In PA regions, where the southerly wet flow should remain more dominant, temperatures could easily remain in the low 80s.

Long range: Both the GFS and the ECMWF forecast the jet stream to establish a zonal flow over the region in the 8-10 day forecast period. GFS forecasts a surface low pressure system to work its way into the jet and swing its way over the area on Tuesday or Wednesday. It’s too far out to predict how much precipitation it can produce, but it’s a fair guess to say it will be significant. Temperatures should remain fairly steady in the low 80s.

Mid-July is, climatologically speaking, the hottest month on the calendar in the western New York/Twin Tiers region. It is also the one where high temperatures are relatively stable. The average high temperature for the Little Valley station is 78 for every day between July 5 and August 5, with the exception of July 22, which peaks at 79.

~J.M. Fuller

Saturday: A mix of clouds with a few breaks of sun. Thunderstorms likely in the early afternoon. Afternoon high temperatures in the upper 70s. Southerly winds, less than 10 mph.

Sunday: A mostly cloudy and uncomfortably warm overnight, with low temperatures dropping only into the low 60s. A mix of clouds and sun on Sunday, with a much lower chance of thunderstorms. Afternoon high temperatures around 80. Westerly winds, less than 10 mph.

Monday: Mostly cloudy, warm and humid for the overnight, with low temperatures in the upper 50s. Clouds break on Monday, with temperatures maxing out in the low 70s in New York, mid-70s in PA.

Tuesday through Friday: Cooler temperatures will be present for Tuesday and Wednesday, with the ensemble members indicating temperatures somewhere between the upper 60s and low 70s. In the Bradford region, temperatures will stay in the mid-70s through Tuesday, before dropping to around 70 on Wednesday and Thursday. By Thursday, the rest of the region begins warming back up to the upper 70s, and eventually 80s by Friday. Low temperatures will remain in the 50s throughout, with low 50s on early Tuesday and Wednesday, and mid-to-upper-50s for early Thursday and Friday. In the realm of precipitation, it appears that people in the Pennsylvania portion of the region will get hit with some precipitation on Wednesday, with some of the most southerly regions of the New York part of the region getting grazed with a few sprinkles. It should otherwise remain mostly dry.

Long range: The ten-day outlook appears to bring a very warm jet (850 temps approaching 20 C) over much of the Northeast, which would indicate temperatures as high as the upper 80s, possibly grazing 90, if clear skies prevail. The air mass appears to be very warm and humid, so there is the significant possibility of convective precipitation during this time period. (One brief caveat: the model in Europe currently doesn’t have 850-mb temps that high, and has such temperatures indicating low 80s).

Where we should be: The average high temperature for June 12 in Little Valley is 73 degrees. The average high for June 22 is 75-76.

Apologies for my mini-vacation last week. It had nothing to do with me dodging the severe weather this weekend, and more to do with some personal issues; this past week has been quite the emotional drain.

Yesterday morning’s thunderstorms were enough to merit a tornado warning for portions of the area (from Salamanca south and east) as well as a severe thunderstorm warning, but no tornadoes were reported. Considering how few people were awake at 5 a.m., that is a very good thing. The good news is that after all of that, a sprawling bubble of high pressure (of the “continental polar” variety, for those who are weather buffs) appears to be building in from the northwest, bringing mostly sunny skies and seasonably cool temperatures for this time of year. This week is probably not the week to break out the bikinis.

Monday: A few clouds early, breaking later. Unusually cool, with high temperatures in the low-to-mid-60s.

Tuesday: Clear skies. An unusually cold morning with temperatures dropping into the upper 30s by Tuesday morning (GFS-MOS, one of our guidance products, has Bradford’s low dropping dangerously close to the freezing mark, but given that the dew points aren’t forecast to drop that low, I have a tendency to consider that an inconsistency, which is a relief because the last thing we need around here is a frost in the middle of June.) Temperatures rebound to the upper 60s for Tuesday afternoon.

Wednesday: Clouds move in during the early morning hours. Early low temperatures in the upper 40s. High temperatures in the mid-60s. There is some uncertainty about precipitation, since one model is being more aggressive with the advancement of a low pressure mass than the others, but I am inclined to suspect that the GFS is unnecessarily broad with its precipitation, and that the expected rain will likely not happen until the overnight headed into Thursday.

Thursday through Saturday: The models are, however, in general agreement that the core of a low pressure system is indeed forecast to cross over the Appalachians on Thursday, bringing significant precipitation, of approximately a half-inch. This will have the additional benefit, however, of re-establishing the warm, southerly flow we saw last week, and high temperatures can be expected to jump back into the upper 70s– eventually. Thursday’s high temperature will likely only reach the low 60s, a dreary day for sure. Friday will plateau in the low 70s and Saturday will reach the upper 70s (possibly even low 80s), just in time for the weekend. Low temperatures for the same time period will be in the upper 40s for early Thursday and Friday and 50 for early Saturday, with the possibility of an upper 50s low for early Sunday. Precipitation remains very questionable for Friday onward. Expect Friday to be dry, but be on the look out for convective precipitation (i.e., thunderstorms) on Saturday.

~JMF

Thursday: Rain in the overnight. Early lows in the mid-50s. Drier and cloudy during the day, with a few breaks of sun. Afternoon highs in the low 70s.

Friday: Cloudy. Early lows in the upper 50s. Highs in the mid-70s.

THIS FORECAST IS SEMI-AUTOMATED. A FULL FORECAST IS FORTHCOMING.

As of 9 a.m. Friday morning, a somewhat chaotic pattern appears to be forming on the surface. The good news appears to be that the precipitation I predicted last week appears not likely to happen– key word being “appears.” The precipitation around the area appears to be very widely scattered. Furthermore, looking at the upper-air soundings, the lapse rate appears to be nowhere near what would be necessary to produce serious convection. Beyond that, the rest of Memorial Day weekend looks dry and comfortable.

Friday: Mostly sunny, humid. A marginal chance of a convective precipitation in the afternoon, though this is not particularly likely. Afternoon high temperatures in the upper 70s.

Saturday: Mostly sunny. Early lows in the mid-50s, around 50 or so in the valleys. Afternoon highs in the upper 70s.

Sunday: Clear skies. Early lows in the low 50s. Afternoon highs in the low 80s.

Memorial Day through Thursday: The GFS model has a cold front swinging through right in time for Memorial Day itself. It won’t have an immediate impact on temperatures (the cooler air is several hours behind the front) so temperatures will remain in the upper 70s, but if this forecast verifies, there will be rain, particularly in the afternoon. The morning should be more favorable weather, especially for local parades, with early lows in the low 60s, though the humidity might make things uncomfortable. The rain will continue through Tuesday morning, when the cold front pushes through, and temperatures will drop from their balmy highs of the past week or so, though dry and more comfortable conditions will set in for Wednesday and Thursday. Low temperatures will be in the upper 40s and high temperatures will be in the upper 60s, a few degrees below the average of 70.

Long range: Another small body of rain showers is expected to move into the region Friday, June 4. The high temperature that day will likely remain in the upper 60s. The model has it lingering for Saturday, June 5 but I would tend to suspect that’s simply long-range blur and that the region will be dry, if maybe somewhat cloudy, for that day. A trough of cool air will move in for that weekend, dropping low temperatures for those days into the mid-60s. By Monday, however, a ridge moves in with 850-hPa temps of around 14 C, which (if the model prediction holds– the model predictions go out 16 days but they’re usually only any good out to 10) will broaden and establish a stretch of several days of dry and warm (around 80 degrees) weather.

~J. M. Fuller