ITHACA, N.Y. — If April showers bring May flowers, then this year should have more blossoms than a greenhouse. In the meanwhile, seasonable temperatures and rain will prevail for practically every day of the week ahead. You’ll be using the umbrellas quite a bit this week, folks.

Graphic courtesy of NWS Binghamton.

Your Weekly Weather

It’s been a damp weekend as a large area of low pressure continues to churn a large swath of rain over the Mid-Atlantic and Northeast. This kind of storm system is known as a “panhandle hook”, because it originates on the leeward side of the Rocky Mountains over the Texas and Oklahoma panhandles, and takes a hook-shaped path, first eastward into the Great Plains, and then northeastward into the Great Lakes. They tend to be more common in the winter due to the strength and positioning of the jet stream aloft, but can develop in the late fall and early spring as well.

On the one hand, because this kind of storm system passes over the Great Lakes, it keeps the Southern Tier of New York in its warm sector for an extended period; hence, temperatures popping into the low and mid 60s briefly this evening. However, with its ample Gulf of Mexico-sourced moisture and large precipitation shield, skies will remain gray, and light to moderate periods of rain will persist. With that influx of atmospheric energy in tandem with the warmer air, a thunderstorm or two is even possible. If you’re heading towards Buffalo where more unstable air is funneling in, they could be severe, so be mindful if heading westward this afternoon and evening.

For the rest of your Sunday, expect scattered periods of light to moderate rain and overcast skies, with a southerly breeze and highs in the evening in the mid 60s. For Sunday night, the wet pattern continues, with overcast skies, scattered rain showers and a thunderstorm or two possible, and lows in the upper 40s. Rainfall amounts from Sunday afternoon through Monday morning will total between one-quarter and one-half of an inch. With stream levels near and even a little below normal going into this event, the risk of flooding is low.

So now comes the part where you’ll probably want to curse a bit. That panhandle hook starts to ride over atop the ridge of warmer air, and becomes stacked with another an upper-level low aloft. That will not only help it persist (when they stack, the physical, dynamic effect allows the storm to have more efficient outflow – it breathes better, in a sense), it also slows it down, because it’s a deeper air column. To apply another analogy, this is like gluing two stream rocks together and putting that bigger mass back into a stream. It’s harder to dislodge, right? In this meteorological case, the low stall out over Upstate New York, and the steering flow will struggle to dislodge it for days, likely taking until Wednesday or so, after the storm system weakens and begins to break down, allowing the westerly flow to overwhelm it and finally shunt the low pressure area east-southeastward.

For your Monday, as the low stalls out over Upstate, the warm sector will move eastward as well, and the cold front slowly moves through during the day. It will be noticeably cooler, but the air behind it isn’t cold enough for snow except for maybe the highest elevations briefly. It will be cloudy with periods of light rain and highs in the low 50s. New rainfall amounts will be less than one-tenth of an inch. Monday night will see the cooler air settle in, with cloudy skies, scattered light rain showers, and lows around 40°F. New rainfall amounts will be less than one-tenth of an inch.

Tuesday will be a case of wash-rinse-repeat, though as the storm decays, the rain showers will become less numerous. It will be cloudy with a few scattered light rain showers, and highs around 50°F. Tuesday night will be cloudy with a few scattered light rain showers, and lows in the upper 30s.

To start off your April, you might see a few rays of sun as the cloud cover begins to break apart in the afternoon and evening hours. But otherwise, plan for another cloudy day with a few scattered light rain showers, and highs around 50°F. Wednesday night will be a little cooler without that cloud “blanket” overhead. It will be mostly cloudy, with a low in the mid 30s.

Thursday is looking the most pleasant of the week; or at least, the driest, as high pressure briefly builds in. We can’t deny the possibility of a few rain showers on the back side of the departing storm system. The models have it becoming re-energized over the Atlantic as it interacts with a second system that soaks the South early the week. But the chances of that aren’t great (20-30% chance). Otherwise, it;ll be partly cloudy with highs in the low 50s. Thursday night will be partly cloudy with a few scattered rain showers or snow showers in the higher elevations, and lows in the mid 30s.

Friday will be a little warmer, as a low over the Southeastern U.S. and a developing storm system over the Great Lakes drive a stronger southerly wind into Tompkins County. A few showers from the Atlantic storm as still possible, but the chances are low and we should have a little more time to dry out before the Great Lakes system comes in for the weekend. Plan for partly sunny skies, a few isolated rain showers, and highs in the mid 50s. Friday night will be mostly cloudy, with a chance for a few brief rain showers, and lows around 40°F.

Looking at next weekend, it’ll be rain with that incoming low, though this one doesn’t seem to have quite the staying power as this weekend’s event. Saturday will be mostly cloudy, with rain likely and highs in the upper 50s. Saturday night will be mostly cloudy and in the low 40s, and Sunday is looking dry with partly cloudy skies and highs in the mid to upper 50s.

Graphic courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking ahead into the first half of April, well, you won’t be breaking out the shorts and sundresses anytime soon. The prevailing pattern calls for a ridge in the jet stream in the west, and a trough in the central and eastern United States, which should lead to temperatures marginally below normal (normal for the first half of April is in the 55-60°F range for highs). On the bright side, and one can take that literally, it’s also expected to be on the dry side after this week, with abnormally high precipitation limited to the lower Great Plains, interior Western U.S. and the tip of Florida. You might still need a warm coat, but at least there’s a chance to break out the sunglasses.

Brian Crandall

Brian Crandall reports on housing and development for the Ithaca Voice. He can be reached at bcrandall@ithacavoice.com.