It’s been a wild weather week that started with a tornado outbreak across half a dozen states in the South, and torrential rain fall that dropped as much as 2 feet in Florida, and as much as 6-8″ across the Northeast (resulting in incredible scenes like this landslide in Baltimore).
Fortunately, the weather has taken a turn for the better and will remain that way much of the coming week. This weekend is shaping up to be a nice one with temperatures on Saturday and Sunday reaching into the upper 60s to the low 70s across the region. There is a chance on both days of popup showers or thunderstorms in the afternoon, especially in inland areas with better daytime heating.
GFS model upper air (500mb absolute vorticity) output for this coming Wednesday. Note the strong trough out west (dip in the contour lines), and a ridge over our region (bulge towards the north of contour lines). Ridges correspond with high pressure and good weather while troughs denote low pressure and poor weather.
We’re finally turning the corner on warmer spring temperatures as the start to next week Monday-Wednesday will continue to feature high temperatures consistently in the low-mid 60s (about average). Dry and mostly sunny skies should also predominate as a ridge of high pressure (see above) builds in over our region.
Are you wondering why today is so cool with highs barely touching 50, but tomorrow is forecast to have high temperatures in the low 70s? It’s because there’s a warm front currently situated to our south. Let me clarify the two most common types of frontal boundaries:
A warm front delineates a boundary where the airmass behind the front is significantly warmer than the airmass ahead of it.
A cold front, not surprisingly, applies to the reverse situation and delineates a boundary where the airmass behind the front is significantly colder than the airmass ahead of it.
Currently, a warm front sits south of us, causing an onshore flow (easterly winds) off the frigid Atlantic Ocean. Why the easterly winds? Looking at the image below, you’ll see yellow contour lines that demarcate isobars of pressure. In the Northern Hemisphere, air flows counterclockwise around a low pressure center and clockwise around a high pressure center. The counterclockwise flow also applies to the frontal boundaries attached to a low pressure center.
In our present situation, the air flows towards the east (counterclockwise) south of the west-east oriented warm front (in red), and then from the east to west north of it. Hence, we are experience very cool conditions, and the moisture being funneled off the Atlantic Ocean into our region is fueling these steady showers.
Current surface analysis from the WPC with my overlay showing movement of the warm front to our south.
We should actually see temperatures begin to rise overnight as the warm front pushes through the area. Once this occurs, we will be in what is referred to as the “warm sector”, which is an area that sits behind a warm front and ahead of an advancing cold front. This type of setup is favorable for the development of thunderstorms.
Therefore, Thursday will be a warm, cloudy day with high temperatures in the low 70s and a chance of showers and thunderstorms in the morning.
Friday, with the cold front having passed through, conditions will clear up and we’ll have a nice, sunny day, with temperatures near 70. There will be a chance for afternoon showers.
Saturday continues the trend of nice weather with another day in the upper 60s and mostly sunny skies. Again, there will be a chance for afternoon showers, especially inland where daytime heating can produce enough energy (and instability) to induce those showers.
One other note about today and tomorrow, and that’s the whopping headline numbers for how much rain is forecast to fall, with totals ranging from as high as 3″+ in the western portions of the Tristate to 1.5″+ in the east. This could easily cause flooding in poor drainage areas, small streams, and urban areas.
The atmosphere over the area the past couple days has been both exceptionally dry and abnormally cool. This trend will end Friday with the approach of a cold front and low pressure system. Because the air mass currently in place is so dry, it will be difficult for the air to moisten at the outset Friday. Thus, forecasters are calling for a mostly dry day with increasing cloud cover, and rain showers moving in over the course of evening and overnight hours. High temperatures Friday will remain in the low 60s.
North American Model simulated radar image for Saturday @ 2PM EST
Saturday will remain a cloudy day with the chance for showers diminishing but still present. As the simulated radar image above suggests, there should be a break in precipitation between Friday evening and Saturday afternoon. However, it does appear that there is enough upper air support for afternoon showers and even some scattered thundershowers are possible Saturday afternoon. High temperatures will be warmer in the upper 60s. Skies should gradually clear once showers pass through, so the latter half of the day will still be sunny.
Sunday temperatures will cool off again with the passage of the cold front Saturday, however, sunny skies will return with high pressure building. Temperatures should be pleasant in the low 60s. Monday looks at this point to be a clone of Sunday.
Severe Weather in the Great Plains Sunday
It’s definitely severe weather season at this point in the Plains States and Tornado Alley. These areas have been repeatedly pummeled the past few days by severe hail storms. This weekend promises to be no different. As you can see below, a strong low pressure center is forecast to develop in the lee side of the Rockies Sunday with central pressure as low as 988mb.
Meanwhile, in the upper atmosphere, a vorticity maximum (see below) is forecast to form, with an area of strong divergence just to its east near the forecast center of the surface low. Upper level winds will be largely unidirectional. These are all ideal conditions for a severe weather outbreak. As a result, a wide swath of the Plains States from central Texas through Oklahoma, Kansas, and into Southeastern Nebraska have been placed under a Slight Risk area for severe weather by the Storm Prediction Center.
Note the strong low pressure center forecast to develop over the lee side of the Rockies – central pressure of 988mbUpper air charts for Sunday afternoon. Note the strong vorticity maximum (area of dark red) over eastern Colorado.
You can feel that cold front has passed, can’t you? A stiff northwest wind is ushering in an unseasonably cool air mass, and temperatures will be quite a bit lower than yesterday, with high temps about 10 degrees less than yesterday in the mid-upper 50s. Cloud cover should continue to diminish throughout the day.
Windy and cool weather persists Thursday – with high temperatures again struggling to hit 60. The breezy conditions and very dry air mass in place will lead to conditions conducive to the spread of wildfires.
GFS model’s output for Friday
Our next shot of rain comes Friday, with a weak low pressure system moving over the Great Lakes and a trailing cold front. Forecast models suggest the system weakens as it approaches, hence lowering the chances for rain. If it rains, only light, showery precipitation is expected. High temperatures Friday will be slightly warmer, in the low 60s.
Saturday & Sunday – So far, we have a nice weekend on tap with mostly sunny skies and temperatures slightly below average in the low-mid 60s both Saturday and Sunday.
Sunny skies are your headline for weather this weekend. After what’s been a rudely cold interruption to spring, we’re returning to more seasonable temperatures and a calm weather pattern.
High pressure will dominate the area Saturday leading to sunny conditions with temperatures rising into the mid-upper 60s.
Sunday – high temperatures will be somewhat inhibited by onshore winds off the ocean as the high pressure center moves to our northeast and winds turn to the northeast and east.
Monday – the streak of pleasant weather continues after a cold start to the morning with highs again reaching the low 60s under sunny skies.
Next chance of precipitation will be Tuesday with a weak low pressure system and cold front moving in from the Great Lakes.
We’re going to have a splendid weekend weather-wise in the NYC region. There will be some rain later this evening and into the overnight hours, but things should dry up before sunrise Saturday. High temperatures today will be comfortable in the mid to upper 60s, with western portions of the region possibly topping 70. The south wind will tend to keep inland areas warmer than coastal portions where the wind will be bringing in colder air off the Atlantic where sea surface temperatures are still only in the 40s.
Projected radar reflectivity for about 8PM EST, when we can expect the bulk of the rain for Friday night.
Once the rain lifts out, Saturday is shaping up to be a gorgeous day, with sunny skies and high temperatures in the mid-upper 60s in NYC. Inland areas again will see even higher temperatures with highs near or above 70, while eastern portions of Long Island will see temperatures in the lower 60s due to the continuing cooling influence of southerly winds off the ocean.
Southerly winds will continue to usher in increasingly warm and moist air Sunday with high temperatures in the low 70s inland and in western portions of the region, mid-upper 60s in NYC, and cooler temperatures in the east and coastal CT.
Monday will be the warmest day of the stretch, with highs easily topping 70 area-wide, again with the exception of coastal waters in eastern Long Island and CT. Dense fog may develop overnight Sunday due to the increasingly saturated air mass moving into the area.
Tuesday will be a messy day with a strong cold front moving in from our west. Temperatures will be significantly cooler, with highs probably only in the mid-50s. The Hydrometeorological Prediction Center is forecasting a significant rainfall event. This sharply tilted cold front is associated with a strong low-level jet streak, which will help usher in very moist air from the Gulf.
Note the extremely meridional (north-south) orientation of air flow on Tuesday, indicating a strong frontal boundaryCheck out the swath of forecast total of 2.5″+ of rainfall Monday-Tuesday in our area!
After Tuesday, get ready for a serious cooldown, as temperatures behind this strong cold front will only be in the mid-upper 40s!
A beautiful Wednesday today, and another superlative day on tap for Thursday. Plenty of sunshine both days with only some scattered fair weather, puffy cumulus clouds. Temperatures will be slightly above the average of 55 with highs topping out near 60. Tonight, clear skies and calm winds will provide ideal conditions for radiational cooling with lows near 40 in the city and much cooler in the outlying areas. Northwest winds today will turn to the southwest tomorrow ahead of an incoming cold front, so it will feel warmer tomorrow than today even though the air temperature is going to be about the same.
Friday we’ll see a chance for periodic showers during the day and into the overnight hours. High temperatures will hold steady around 60.
Low pressure center with a trailing cold front moving through the area Friday
Once the cold front moves through Friday night, it will usher in a gorgeous weekend, with dry conditions, sunny skies, and high temperatures in the low 60s! Best weekend so far this spring, so definitely go out and enjoy it.
A chilly start to the weekend as we have cold easterly winds off the ocean, and a deck of clouds overhead. Rain will pick up in coverage and intensity as the day goes on, and it promises to be more or less a washout tonight.
Cloud deck building over the area, bulk of the actual rain is still off to our west over Central PA
Fortunately, the frontal system responsible for the rain will clear out of the area by Saturday. Sunny conditions will prevail, with winds turning from the east to the west and picking up to 15-20mph by the afternoon. High temperatures should top out around the mid-upper 50s, right about average for this time of year. Clear skies overnight Saturday will allow for good radiational cooling, and low temperatures could dip into the mid-upper 30s across the region.
Sunday promises to be the best day of the weekend, with high pressure firmly in control over the region. Sunny skies should allow for a mild day with high temperatures approaching 60.
The next storm system moves into the area later Monday into Monday night, with another chance for rain. Temperatures Monday could top 60 again with warm air flowing ahead of an approaching cold front.
Get out there and enjoy the sunny, mild weather while if you can today. We caught a nice break and got enough sunshine today that we’ll probably top 60 in quite a few spots around NYC. Clouds will increase over the next couple hours. Conditions will steadily deteriorate as a surface low pressures system currently spawning some severe weather over the Plains states tracks northeast into our area. Friday – keep the umbrella handy as periods of showers are likely to occur throughout the day, with increasing coverage and intensity later on in the day into the overnight hours. An steady onshore breeze will usher in much cooler air off the ocean (sea surface temperatures offshore of the region are only in the upper 30s to low 40s). As a result, high temp will hover in the mid 40s.
Saturday – the storm system bringing us rain Friday into Saturday will advance a warm front through the area, and we’ll see a rebound in temperatures and gradually clearing skies. High temps could again top 60.
Sunday – another pleasant and mild spring day as high pressure moves into the area. Mostly sunny skies with a high again near 60.
Monday – our next shot at rain will come Monday-Tuesday of next week, with a storm system forecast to develop in the Gulf. This storm will track northeast through the Ohio valley into the Great Lakes, and a trailing cold front will bring us some steady rain. High temperatures Monday will be around 60 with warmer air flowing from the southwest ahead of the cold front. Long Island and CT shorelines will see cooler highs with an onshore flow.
Our next shot at rain – a low pressure system moving from the Gulf into the lower Great Lakes, and a trailing cold front.
If you’re getting ready to venture out this evening make sure to bring an umbrella and wear your rain gear as a heavy rain event is in store for the New York City area. This will be an extended rainfall event leading into Monday. temperatures today will peak at around 50, near normal. The heaviest rain will be falling from approximately 8 p.m. tonight into the overnight hours. Winds will be at around 25-35 mph. Parts of the area are forecast to receive between 1.5″-3″ of rain in the next 48 hours, which could lead to some minor flooding in poor drainage urban areas and small creeks.
So, in general expect conditions to gradually deteriorate through the day and the intensity of rain to pick up. Rain will continue on Sunday, albeit with diminished intensity. Temperatures will hold steady around 50.
Refer to the diagram below, which represents the North American models guidance for this evening at around 8 p.m. Note the areas of blue and bright blue that correspond to rainfall rates anywhere between .75″ to 1.5″ per hour.
Rain will diminish by Monday afternoon as the low pressure center responsible for the heaviest rains moves off to the northeast.
High pressure will move in Tuesday, with a weak cold front moving through later Tuesday. This frontal boundary is not forecast to produce any precipitation. Ahead of this frontal system, we’ll see temperatures rebound to seasonal levels in the mid-upper 50s and partly cloudy skies. Wednesday will likewise be a seasonable day with mild temps near 60.
Light rain is possible Thursday, Friday, and Saturday of next week, but it’s much to early to be certain. GFS model also shows a possible coastal storm for next Tuesday.
