CPC says we are now in neutral ENSO conditions, and they expect that to be the case through most or all of the summer. The majority of ENSO models project neutral conditions for the remainder of the year, but a number of what are called ‘dynamical’ models, like the CFS, favor a transition to el nino. CPC’s bottom line: odds are even for either neutral ENSO or el nino by fall and winter. In the near term, the MJO remains “incoherent”, having no measurable effect on tropical convection or our weather, although there are some hints that it may go back to active in about 2 weeks. No signs of any severe weather threat anywhere near us this week into early next week, although some convection will occur tonight/Monday night in spots. Ensemble means at the 500 mb level/surface suggest our next best chance for a warmer than average pattern may have to wait until around May 20-22, when heights are progged to begin to rise. In the meantime, there’ll be weak troughing in the east, with a transition to more zonal conditions a little more likely next week.

As I post this, the last of the rain and snow showers are weakening over the southern tier. There’ll be a brief warming trend on Thursday, but it comes ahead of another sharp cold front, behind which lies more below average temperatures for several days. A brisk breeze should protect us from frost on a colder Thursday night, but Friday and Saturday nights could bring a new frost threat–even a freeze in some valleys–depending on cloud cover. Latest indications seem to be pointing to a dry Saturday, with an area of low pressure staying far enough to the south so that even the southern part of the viewing area would escape showers. That Saturday dryness, on a Tuesday night, is far from carved in stone, however.  Another large cutoff low will be developing toward the end of the weekend, but this one will be far to our NE. Its circulation is likely to keep cool temperatures with us into Monday. Models and ensembles are pointing in the direction of a zonal flow which should bring a mean of average to eventually somewhat above average temperatures after next Tuesday. The GFS may be a day too fast to warm us up so significantly on Tuesday, as is often the case. The Euro has us quite chilly into early next week, before that zonal flow finally begins to take hold. As always, I remind you that ensemble means cannot discern embedded short waves very well as we get further out in time.

As of Saturday afternoon the National Weather Service issued a winter storm watch for all of Western New York with varying snowfall amounts for Sunday evening until Monday Evening.  The NWS is comparing this storm to the one from April 2005.

Here is a small piece from their post earlier.

“IN TERMS OF HOW POTENTIALLY UNUSUAL THIS WHOLE EVENT COULD BE (ESP THE SNOW ASPECT OF IT)…NEARLY ALL OF THE MAJOR FORECAST PARAMETERS ARE 4 TO 5 STANDARD DEVIATIONS FROM NORMAL. IT IS CERTAINLY SIGNIFICANT WHEN A COUPLE FORECAST PARAMETERS ARE THAT ANOMALOUS…BUT WHEN NEARLY ALL OF THE MAIN FACTORS ARE THIS FAR FROM NORMAL…THEN THE EVENT STARTS TO RISE TO THAT OF A MEMORABLE OR EVEN HISTORIC STATURE. THAT BEING SAID…THESE PARAMETERS HAVE TO COME TOGETHER IN THE PERFECT MIX AND THAT IS STILL FAR FROM A CERTAINTY.”

The closer we get the more the models have been staying the same.  After the graphics upgrade we have a new model that allows for 1km resolution and this is what it spit out.

This is close to the NWS totals and what the NAM was showing this morning.  Later this afternoon the latest run of the NAM moved the heaviest amounts further west.

There is going to be some wiggle in the models but the general story stays the same.  This could very well be a memorable event.

http://policlimate.com/weather/current/gfs_namer_cloud.html

The GFS is showing the low deepening to 983 mb low by early morning Tuesday.  Significant to say the least.

By Sunday night the storm will start to bring in rain showers and mixed precipitation.  By Monday morning snow accumulations will be possible especially in the high terrain.  The snow showers will be heavy and wet.  With the warm spring we have already seen foliage and just a few inches of this snow can bring down tree limbs.  Widespread power outages are expected as the snow continues potentially through Tuesday morning.  As shown in the models over a foot of snow is possible in the southern tier and areas east of the city.  Some of the snowfall totals near the lakes may be less because of melting and the potential for slightly warmer temperatures causing mixed precip instead of snow.

Stay with the 4 Warn Weather Meteorologists as we update the forecast.

You’ll see it first on News 4 at 5. For weeks now, our 4Warn meteorologists Don Paul, Mike Cejka, Amelia Segal and Bryan Shaw have been trapped in the weather office working on a secret project! Actually they’ve been training on a new and complex package of weather graphics that will change dramatically the way they tell the weather story each day.

Even though he works until midnight, Chief Meteorologist Don Paul has been coming in at 9:30am each day this week to prepare for News 4's conversion to a new computer system for displaying weather graphics. Keith Cavey, from Weather Central in Madison, Wisconsin, is a meteorologist who trains other meteorologists around the country on the 'Fusion' system.

Chief Meteorologist Don Paul and Weather Central trainer Keith Cavey tell me the 'Fusion' system will provide News 4 viewers with the most advanced weather graphics in Western New York. It has the ability to show viewers the weather where they live.

Meteorologist Bryan Shaw has spent many, many days working to convert the Fusion graphics into appropriate use for Western New York weather. We'll all see it tonight at 5 for the first time with Meteorologist Don Paul. I don't mind telling you, he's a little nervous about this, but we are cheering him on!

Look for more Channel 4 photos on my Facebook page. Give it a “like” to stay updated!

After a fairly typical April cool spell (notable only because of March’s extraordinary warmth), more springlike conditions will return, beginning on a dry and beautiful Friday. But the above average temperatures for the weekend will be dampened by–what else–growing dampness. A series of disturbances moving over the Great Lakes will gradually increase the chances for scattered showers & a few tshowers on Saturday (at the time of this posting, the afternoon hours appear to hold a higher chance),  with more occasional rounds of showers & tstorms on Sunday. There is no clearcut sign of a severe weather threat for Sunday, but we’ll have to keep an eye on jet structure and placement at that time and–possibly–again by Tuesday.

There continues to be quite a bit of uncertainty about the placement of a frontal boundary in the Mon-Tue period, with a 20-25 degree temperature differential on either side of the front. As the NWS has noted, there is considerable “bust” potential in our temperature forecast at that time. With the proximity of this front and string of disturbances, our total rainfall will be potentially significant in spots.

In the meantime, as we finish out this workweek, there will be a growing risk of Severe Tstorm/Tornadic Supercells in the southern and central plains, probably edging up toward Iowa during the weekend.

After the warmest March–by far–in Buffalo record keeping history, April is turning out to be another story. With the enormous 13.4 degree positive mean temperature anomaly, we’re all familiar by now with the premature budding and flowering of many plants. The vulnerability of those buds and flowers continues this week, with the frost already having occurred on Monday night, and the likely additional frost to come later in the week. As of this posting, signs are pointing to another sharp cooldown early next week. There is some evidence that the shifting phase of the MJO (Madden-Julian Oscillation) is the main driving force behind the cooler pattern which will dominate the east much (not all) of the time into next week. The  more commonly examined indices, the AO, PNA & NAO are not headed into phases which would support the eastern trough. Even today’s ensemble means are supporting some fairly sharp cooling in the first half of next week. These ensembles are generally not as amplified as the operational models, so when they show really digging troughs, meteorologists sit up and take notice.

There will be some decent warming this Easter Holiday weekend and possibly again by next weekend. But the overall pattern does favor a negative temperature anomaly over the next couple of weeks–in the mean.

The survival of many prematurely blossoming plants’ and trees’ blossoms will be in jeopardy Monday night. Clear skies, dry air, and a cold airmass will combine to produce Hard Freeze conditions in the interior and lighter Freeze conditions closer to the lake. The evening may begin with a brisk breeze, but that wind will gradually diminish. Temperatures will recover somewhat on a Sunny Tuesday, and move well above average on Wednesday ahead of another cooldown for Thur-Fri. That cool airmass does not look as potent as the current ridge of Canadian high pressure, but some frost could reoccur those nights in the interior. Night time lows will be returning to the 30s. Tonight’s (Monday) lows will range from the teens in sheltered valleys to the mid 20s in the eastern suburbs to the upper 20s close to the lakeshores. The overall pattern in the Day 6 and beyond time range looks somewhat unstable, with ups and downs in the temperatures, rather than persistent warmth or chill. There is no sign of a return to the extraordinary warmth experienced last week. 3 consecutive 80 degree days in March, as many of you have figured out, is something we’re statistically unlikely to see again–even with global warming–for many years.

The installation of the Dual Polarization upgrade to the NWS Doppler radar is now underway, taking the radar out of action for this week. The exact power-up date is undetermined, but Judy Levan says these installations have been going very smoothly and somewhat faster than expected at other NWS offices as of late. Fortunately, major convection is unlikely this week, so this is going to turn out to be an opportune time for the work to be done. Hopefully, our luck will hold until the radar is back up and running.

The warm 500 mb ridge will be peaking in our region on Wednesday this week. The work week will stay unseasonably warm, with a few degrees cooling arriving on Friday, and a little more over the weekend with some unsettled conditions at that time. But as implied in the headline, Cooler is the word–not Cool, by climatological standards. Still after the amazing warm spell we’ll be continuing to experience, Monday’s probable highs in the 50s may SEEM cool to many. Not much has changed in the extended range since a week ago today, which reflects the high confidence we had in the extent of this warm spell’s persistence and strength. The Ensemble Means still show flattening of this amazing ridge by the weekend, and maybe a little more retrograding of the ridge by early April. But there are no apparent signs of any shots of below average temperatures.

After this spectacularly unusual winter, we are now into a spectacularly early growing season, as most of you have noticed.  While that could still prove to be worrisome later in the spring should a sudden pattern shift develop, for now it’s bloomin’ good news. The ensemble means are very much in agreement that unseasonable warmth (with only minor variations) will persist through the better part of next week. At that time, the pumped up eastern ridge should begin to flatten, but in the ensembles we’d still be in a zonal/Pacific flow late in the month. However, we’ve seen how ensemble means can break down when embedded short waves amplify. I’m sure fruit growers are going to be concerned seeing their blossoms open so early as they will this year, leaving them very vulnerable to frost and freeze conditions should they come along.

All that said, given the limitations in resolution and timing for ensemble means, there are no visible signs over the next 16 days of such an occurrence, so all we can do is enjoy the early spring. We’ve already hit 68 today/Monday the 12th and Thursday should again bring us close to that range–with 70 not out of the question. The eastern ridge actually gets more amplified by Sun-Wed or Thur next week, making some 70s seem quite likely as of today’s guidance. We may get some garden variety thundershowers toward dawn tom’w and again late in the week. Well above average temperatures are highly likely for Sunday, Parade Day, with mild temps preceding on Saturday. Dry conditions are less of a sure thing, with weak disturbances possibly bringing a few showers. As for any tshowers this week, there are no signs today of any potent setup for severe weather in WNY leading to violent tstorms.

No, that’s not the Magic 8 Ball talking. But there are no signs pointing to colder than average weather around here; just occasional shots of seasonable temperatures more than balanced by above average temperatures the majority of the next 16 days. We may even get a few spikes of almost springlike temperatures, generally associated with the warm sectors of vigorous short waves/storm systems–as may be the case Friday and Friday night, for example. One of the main forecast challenges with a mainly west-to-east zonal flow is timing the arrival of embedded short waves, as well as predicting intensity and trajectory/paths for these lows. Beginning later Tuesday night, an area of low pressure headed toward the northern plains will advect warmer and eventually moister air aloft into our region. Some light snow may develop late Tuesday night, and the snow may pick up during Wednesday morning, with a transition to sleet and then just rain. Amounts should be modest, and there may be a little freezing rain before the final change for the afternoon to liquid. There could be a minor coating of snow preceding this transition, and the best chance for any freezing rain would be in sheltered valleys.

Another storm system to watch will be what is currently depicted in most models and various ensemble members as a deepening low which moves to our north during Saturday. As seen in Monday runs, this low could move into a climatologically favored position to produce strong to possibly High Winds on Saturday. While the Climate Prediction Ctr has listed this wind potential as  a Hazard for our region, they’ve also included the chance for Heavy Lake Effect Snow to accompany the wind hazard. Right now, I’m just not seeing evidence of cold advection adequate to produce heavy lake snow, though some lake enhanced snow might develop Saturday afternoon. Of course, the Meteorologists here at 4Warn Weather will be keeping an eye on this system’s potential all week.

La Nina continued to weaken this past week. Even when the la nina colder anomalies disappear altogether (which won’t be too many weeks longer), there will be a lag period in which the impacts from la nina will continue to be felt well into the spring. The CPC long range ENSO forecast is still for neutral ENSO conditions to replace la nina into the autumn, although more ensemble members seem to be flirting with a weak el nino by autumn than had been the case a few weeks ago. Still, the most favored trend is neutral.

As for the MJO, it continues to be active and CPC expects that to continue for the next 1-2 weeks, without much further eastward propagation. That favors warmer than average temperatures in the east, and above average precipitation for the Great Lakes.