Much of the nation’s midsection has been enjoying temperatures more typical of April than February for the past week, with a few hundred record high temperatures broken. That is about to change, as Mother Nature will remind the region that is still February.
One more warm day is expected today, with highs well into the 60s and 70s likely setting more records. However, a cold front will sweep across the region, bringing an end to the record heat, and setting the stage for a snowstorm.
The low pressure system that brought more rain to California over the past couple of days will head eastward, bringing some snow into the Rockies today. As that system moves into the Plains on Thursday it will start to strengthen, drawing moisture northward from the Gulf of Mexico while cold air flows southward on the backside of the storm into the Northern Plains. Where these airmasses meet, snow will develop across the Central Plains states. The snow will be accompanied by winds of 20-30 mph, gusting to 40 mph or more at times, resulting in near-blizzard conditions across portions of South Dakota, Nebraska, southeastern Wyoming, and eastern Colorado on Thursday.
As the system heads eastward, snow will move into portions of the Mississippi Valley and the Upper Midwest on Friday. The heaviest snow looks to stay just south of the Twin Cities, but even there, moderate to heavy snow is likely. By the time the storm moves out on Saturday, a foot or more of snow is possible in a swath from the Central Plains into the Great Lakes.
Snow isn’t the only threat from this system. As the storm moves eastward, record warmth will remain in place across the Midwest. With warm, moist air in place and a strong cold front approaching from the West, strong to severe thunderstorms are possible across portions of the Lower Great Lakes and Ohio Valley on Friday. Some of the stronger storms that form may contain damaging winds, hail, and possibly tornadoes.
The system will continue to move eastward, bringing some rain to the East Coast on Saturday, but amounts should be fairly light, and additional severe weather is not anticipated.
A developing storm system will bring heavy snow to parts of the Southeast and New England this weekend, while the West Coast braces for a lot of much-needed rainfall.
We’ll start on the West Coast, where a series of storm systems will bring plenty of rain to drought-stricken California. While this will not alleviate the drought that has been ongoing for years, it will help to put a big dent into it. The first of the storm systems will move in tonight, and by the time the last one moves through next Friday, rainfall totals of 5-10 inches will be widespread across much of central and Northern California, with many locations, especially along the coast and western slopes of mountains receiving 10-20 inches or more.
At the higher elevations, especially in the Sierra Nevada, incredible amounts of snow are expected. The snowpack, which much of the region depends on for water in the summer as it melts, is already above normal, and over the next week, some locations might see 6-12 FEET of new snow from these storm systems.
Back in the East, a storm system is riding along a stalled out front across the Southeast, producing some snow across parts of the Tennessee Valley and the Southeast. As this system draws in moisture from the Gulf of Mexico and the Atlantic, and runs into an arctic airmass already settling into the region, it will produce heavy snow in places that normally don’t see a lot of snow, such as Georgia, the Carolinas, and the Virginia Tidewater area. In these places, even a dusting of snow can cause traffic nightmares, so heavy snow can bring these areas to a standstill.
The heaviest snow from this system is expected across the Appalachians and also across the Virginia Tidewater area, as the storm gathers strength while moving into the Atlantic. Of course, the 6-12 inches expected across much of North Carolina will cause its own problems, but luckily, the bulk of the snow will fall tonight and Saturday, minimizing the travel problems. The heaviest snow should remain just south and east of the big cities of Washington, Philadelphia, and New York, but a few inches may fall in each location.
Once this storm moves off the Mid-Atlantic coast it will head northeastward, passing a couple of hundred miles south and east of Cape Cod. Normally, this would mean just a little bit of light snow for parts of Southern New England, and for the most part, that’s what we’re expecting. However, for southeastern New England, mainly south and east of I-95, it’ll be a different story from Saturday afternoon into Sunday morning.
There are a couple of factors that will enhance snowfall totals across this region. First, with northeasterly winds blowing off the Atlantic, we’ll get some ocean-effect snowfall. This is similar to the lake-effect snow that you often see near the Great Lakes. Second, temperatures will only be in the upper teens to middle 20s. This means that it will be more of a fluffy snow, which will pile up quicker than a much wetter snow.
The snow should start to develop across Cape Cod and southeastern Massachusetts Saturday morning, and will quickly spread inland. The snow should spread as far inland as central Massachusetts and southern New Hampshire, but it will quickly retreat eastward again, ending in most places during the evening. The exception is Cape Cod and coastal Massachusetts, where northerly winds behind the storm may keep the ocean-effect snow going into the early hours of Sunday morning.
For snowfall totals, we’re not expecting more than an inch or two from southern New Hampshire into Central Massachusetts. Points north and west of Boston and Providence, including the Merrimack Valley, will likely see 2-4 inches, with some heavier amounts across Cape Ann. Along and south of Interstate 95, including the southern and eastern suburbs of Providence and Boston, totals of 6-12 inches seem likely, with the best chance for more than a foot of snow across parts of Plymouth County and Cape Cod, where the ocean enhancement will play a big role.
Behind the system, with fresh snow cover, temperatures will turn colder. Monday morning, temperatures will be in the single numbers across much of the region, with some sub-zero readings likely. The next storm moves in later on Tuesday, and although it will start as some snow or a wintry mix, milder air will move in, with the bulk of the precipitation falling in the form of rain Tuesday night into Wednesday.
Even though we’re into the middle of November, it hasn’t felt like late autumn across much of the nation. That’s about to change, especially across the Plains states and the Midwest.
A storm system will move out of the Rockies and across the Plains states over the next few days. Ahead of the system, warm, moist air will be drawn northward from the Gulf of Mexico. High temperatures on Thursday will be in the 70s as far north as Iowa and Illinois, with record high temperatures expected across much of the Mississippi Valley. The warmth won’t last too much longer though, as a strong cold front will be marching eastward across the Great Plains.
Behind the front, much cooler air will settle southward from Canada. With plenty of moisture being drawn northward, it will fall as snow on the backside of the low from the Central Rockies and Central Plains northeastward into the Upper Midwest. Some of the snow could be heavy, especially in parts of South Dakota and Minnesota, where snowfall totals of 10-15 inches are possible by Saturday evening. Winter Storm Watches have been posted from eastern Wyoming and northern Nebraska northeastward to Minnesota.
Snow isn’t the only hazard with this system. As it strengthens, it will create strong winds across much of the Plains states. Sustained winds of 20-30 mph with gusts to 50 mph or more are expected, especially from the Dakotas into Nebraska. The combination of high winds and snow may result in blizzard conditions at times. A blizzard watch has been issued for southwestern Minnesota, northeastern South Dakota, and extreme southeastern North Dakota.
Once the system moves into southern Canada this weekend, some of the coldest air so far this season will settle into the region. While these temperatures aren’t that unusual for late November, they will be quite a change from the recent warmth that has enveloped the area. Low temperatures will likely drop into the teens and 20s across the region this weekend, with single digits possible. In some of the locations with fresh snowcover some sub-zero readings are possible. The cool air will be short-lived, as temperatures will likely warm back up to above normal readings by early next week. Current indications are that the unseasonably mild weather will persist for the most part well into December across the region.
October can be a time of change in the Northeast. While the first thing that comes to mind is the changing colors of the foliage across the region, the weather also changes, sometimes quite frequently. That’s what we’re going to be dealing with for the next few days.
Unseasonably warm weather was observed across much of the Northeast for the past few days, with high temperatures soaring well into the 70s and 80s across much of the region. This resulted in dozens of record high temperatures. However, some changes are coming, and the warm weather will be a distant memory within the next 24-48 hours.
A cold front moved across the region on Wednesday with little fanfare. That front will stall out to the south of New England overnight. On Thursday, a wave of low pressure will start to approach from the west. This will spread rain and showers into the area. Some of the rain will be heavy, especially from New York into Pennsylvania late Thursday into Friday. With rainfall totals of 1-3 inches and locally up to 5 inches expected, some flooding is likely. Across New England, where a serious drought is ongoing, rainfall will be much lighter, with most locations likely receiving under half an inch of rain.
As that wave of low pressure moves into Upstate New York on Friday, it will lift that cold front northward across the region as a warm front once again. While Friday won’t be as warm as the past few days, high temperatures will still get into the 60s and lower 70s. With dewpoints also in the 60s, it will be a rather muggy day for mid-October.
Meanwhile, there is a tropical disturbance brewing near the Bahamas. Upper-level conditions are somewhat favorable for development, and the system could become a tropical depression or subtropical storm on Thursday. The system will likely head northward, moving towards the Gulf of Maine and merging with the cold front approaching from the west as we head into the weekend. This will bring another round of heavy rainfall into Maine and Atlantic Canada, areas that were hit hard by heavy rain from Hurricane Nicole just a week ago.
Once the system moves into southeastern Canada, it is expected to stall out under an upper-level low pressure area and become a strong extratropical system. It will drag a cold front across the Northeast, bringing much colder air into the region. With strong low pressure nearby and much colder air filtering in, rain will change over to snow across portions of Upstate New York and Northern New England. While the snow will be confined mainly to the higher elevations, this is the first accumulating snow of the season across the area. Several inches may accumulate across parts of the Adirondacks and the Green Mountains.
While there could be a few wet flakes mixed in with some of the rain across lower elevations of Central New England, accumulating snow is not expected.Sunday will be a chilly day, with highs only in the 40s and 50s across much of the Northeast. These readings are 10-20 degrees below normal. Of course, any mention of snow in October across the Northeast will make residents think back just a few years to the pre-Halloween snowstorm that dropped 1-2 feet of snow across parts of the region, setting numerous records. While this system won’t come anywhere close to that, it should make for some spectacular photos of snow-capped mountains and valleys filled with colorful foliage early next week.
The other thing the storm will do and bring gusty winds to much of the Northeast through the weekend. Northwest winds of 15-25 mph may gust to 40 mph at times, especially across New England. This may result in some spotty wind damage across parts of the area. The other effect it will have is to create rather chilly conditions. Just a few days as experiencing temperatures in the 60s, 70s, and 80s, highs will only be in the 40s and 50s across much of the area, with wind chills in the 30s and 40s. This is the type of change that October is known for across the Northeast.
Across much of the West, the bulk of the rainfall that falls during the year usually falls between October and April. This year is starting off right on schedule as a storm system is poised to bring heavy rain to parts of the region over the next few days.
A strong low-pressure system passing south of the Aleutians on Monday will move into the Gulf of Alaska over the next 24-48 hours, before heading towards British Columbia and the Pacific Northwest. The storm will bring heavy rainfall and strong winds to the Aleutians and portions of southern Alaska through midweek. Along the coast, wind gusts may reach hurricane force. With the slow movement of the storm, and the strong onshore winds, heavy rain is likely across much of the Aleutians, with totals in excess of five inches possible.
By midweek, as the storm moves towards the coast of British Columbia and Washington, rain will move into the Northwest. The heaviest rain is expected during Thursday and Friday, with several inches likely west of the Cascades, especially along the west slopes of the coastal mountains. This will likely lead to flooding in some areas. In addition to the rain, strong winds will blast the coastline. Wind gusts of 60-80 mph are possible, especially along the coast of Oregon.
As the system pushes inland, rain will spread southward into northern California by late Thursday, likely reaching as far south as central California. This will bring beneficial rain into portions of the region, including the Bay Area, where several wildfires continue to burn. After a dry summer, this rain will be very helpful to firefighting efforts across the area. Rainfall totals of 1-3 inches are possible, with heavier amounts along the northwestern coast of the Golden State.
As the rainfall moves inland, it will change to snow across the higher elevations of the Sierra Nevada. Snow levels will remain fairly high with this system, likely around 7000 feet. Above that, especially above 9000 feet, snowfall totals of 8 to 16 inches are possible. While this is not the first snow of the season in the Sierras, it is the first significant storm of the season.
Once this system pushes inland, another strong storm looks to follow on its heels. Another round of strong winds and heavy rain is expected to move into the Northwest and Northern California for the weekend. That storm may be the remnants of Typhoon Songda, currently passing out to sea and weakening south and east of Japan.
Winters in the Northeast can be often feel long and cold, leaving residents of the region longing for sunny, warm days in the Spring and Summer. This year, they got quite a lot of them, which didn’t draw too many complaints. However, because it was so sunny and warm, much of the region is now in the midst of a very serious drought.
A persistent ridge of high pressure kept the Northeast dry and warm through much of the Spring and Summer. Most of the cold fronts that tried to move through the region were starved for moisture, thus their main effects were to cool temperatures and lower humidity for a day or two. Thunderstorm activity was common, but aside from localized downpours, there really hasn’t been a widespread heavy rain event across much of the region for several months. That could be changing this week.
A slow-moving cold front will move across the region on Tuesday, bringing showers with it. While the rain likely won’t be too heavy, it should be widespread, which is good news for an area that needs all the rain it can get. The front will likely stall out right along the coastal plain, which may keep the shower activity going into Wednesday right along the coast. However, changes in the weather pattern are coming that promise to bring even more rain to the area.
An upper-level low pressure system will drop southward from the Great Lakes and take up residence across portions of the Ohio Valley and Appalachians. It will likely stay there for several days, before lifting out to the northeast this weekend. However, with the upper-level low pressure area just sitting there, low pressure will essentially remain in place at the surface as well across the same area. This will result in periods of rain and showers across much of the area right through the week. While the rain may be briefly heavy at times, persistent rainfall over several days can add up, with some areas possibly receiving 1-3 inches of rain between Tuesday and Friday, with some heavier amounts possible. Rainfall deficits in this area are on the order of 5-10 inches, so much more is needed, but this is definitely a good start.
Of course, this beneficial rain may not impact the entire Northeast. For New England, the forecast is much trickier. With the low setting up well to the southwest of the area, high pressure will try to build in from the north. This will bring cool and dry conditions into much of northern New England this week. As for southern New England, where the effects of the drought are the most pronounced, the forecast depends entirely on where the low and high set themselves up. If the high is the dominant feature, much of southern New England can expect dry and cool conditions, with gusty east to northeasterly winds bringing some clouds and drizzle in off the Atlantic at times. If the low sets up a bit closer to the region, then the forecast will trend more towards a damp scenario with periods of showers for the next several days. At this point, it’s still a little too early to tell which scenario will be the correct one.
Astronomical fall begins on September 22 at 10:21am EDT, but meteorological fall is defined as the period between September 1 through November 30. While it can and does still feel like summer across parts of the nation, there are more and more signs that summer is winding down.
As the nights start to grow a little longer the farther north you go, the cooler air starts to build up a little more, especially as you head into Canada and Alaska. The cold fronts that drop down from Canada and into the Northern US start to pack a little more punch. One of those fronts is moving across portions of the Upper Midwest and the Great Plains today. The airmass moving into the Rockies and Northern Plains behind the front is sending temperatures as much as 15 to 25 degrees below normal this afternoon.
As that airmass settles in, low temperatures will drop into the 30s and 40s across the Northern Plains and Rockies tonight. Frost advisories and freeze warnings have been posted for western portions of North Dakota for Tuesday morning. By Wednesday morning, the coldest air will move over Minnesota, where low temperatures could drop into the upper 20s and 30s. Additional frost and freeze advisories will likely be issued for this region.
Cold temperatures aren’t the only noteworthy item with this cold front. As the cold air surges into the Rockies, precipitation will accompany it. That precipitation will likely fall as snow in many areas, mainly at elevations above 5000 feet. Across some of the higher peaks, more than a foot of snow could accumulate over the next day or two. Winter Weather Advisories have been issued for portions of northern Wyoming as a result.
Some snow is also possible across the higher elevations of the Sierra Nevada as the cooler air spreads into the West. While accumulations will be minor, this will likely be the first snowfall of the year for this region. Across the rest of the Golden State, temperatures will likely be 6 to 12 degrees below normal on Tuesday, with highs only in the 70s to lower 80s, a welcome change from the 90s and 100s they’ve had for most of the summer.
While this front will bring cooler air into the Northeast later this week, one thing it won’t do unfortunately, is bring beneficial rainfall to the region. It will produce showers and some thunderstorms, and while a few of the storms may contain heavy downpours, they’ll be very localized. Across much of the region, rainfall totals will be generally under half an inch. This will do little to put a dent in the severe drought that much of the region is currently experiencing. Rainfall deficits of 5 to 10 inches below normal since the beginning of March are common across the region.
While this early taste of fall moving into much of the Northern US this week is not uncommon for mid-September, it might not be repeated much this fall. Long-range forecasts are showing the likelihood of a warmer than normal fall across much of the United States.
The pattern across the eastern half of the United States is very conducive to flooding. A high pressure located near Bermuda, called a Bermuda high, helps to direct warm and moist flow from the Gulf of Mexico northward into the United States while in the northern portion of the United States is from west to east dragging a few energetic disturbances towards the eastern United States.
Furthermore, flow in the northern mid-latitudes has slowed down allowing the Bermuda high and cold front across the Midwest and Northeast to remain stationary. The low level jet stream running along or just ahead of the cold front continues to draw tropical moisture north into the northern United States so that many areas across the Mississippi and Ohio Valleys have a flash flood watch on Saturday and Sunday. As this pattern remains stationary, disturbances moving through will allow for plenty of showers and thunderstorms. While considerable cloud cover will lower the threat of intense thunderstorms, which need plenty of energy from the sun, heavy rain, and therefore flooding, is very possible with high and near or exceeding record values of precipitable water. (Precipitable water is a measure of the amount of moisture in the atmosphere if all the water were precipitated as rain.) With this in mind, excessive rainfall is forecast along the front over the next three days. In addition, an upper level low pressure moving slowly north from the Gulf of Mexico will add to the rainfall totals making flooding likely. In this pattern, convective rainfall or rain caused by thunderstorms won’t mean that rain will be constant, more off and on. With the front slowly moving southeast, the off and on rainfall should continue in most places until the end of next week.
Meanwhile, drought has continued to increase across the United States, especially in western New York and eastern New England. While the final location of both the front and upper level energy is key to the exact placement of high precipitation amounts, the rainfall from this week’s rainfall should help to eat into the drought in areas like the Great Lakes and western New York. If the front is further east, then there would be a possibility that eastern New England would get into the higher totals. To lessen the drought, the longer drawn out precipitation is what those regions need more than quick events with high amounts of precipitation because the rainfall needs to soak into the ground and remain in the ground for longer periods of time. So since the rainfall should be the off and on variety, to eat into the drought, one would hope that the rainfall would be many small to moderate amounts rather than a many small amounts and one large amount of rain.
A persistent pattern over the last several months has left much of Northeast in a drought. According to the most recent update from the National Drought Monitor, portions of Western New York and also Central New England are experiencing severe drought.
Heavy showers and thunderstorms have been common across the Mid-Atlantic states recently, eliminating any drought concerns, but the bulk of the rainfall has remained well south or well north of areas that need it the most.
According to data from the Northeast Regional Climate Center, the period between Marc 1 and August 2 is the driest on record for several locations across New York and New England, including cities such as Lawrence, MA, and Elmira and Batavia, NY. Other locations, such as Hartford, CT and Hingham, MA, are in the Top 5 driest March 1-August 2 on record. Many rivers and streams across the region are at near record low levels. Water restrictions and/or bans are in effect for hundreds of cities and towns across the region.
A cold front will cross the region on Saturday, producing scattered showers and thunderstorms. While some of these storms could be locally heavy, most places will receive just light rainfall, which will barely put a dent in the drought. The bigger concern on Saturday is for severe weather across the Northeast. While the timing of the front won’t be optimal for a severe weather outbreak, conditions will be favorable for some strong to severe thunderstorms, especially across Southern New England and southeastern New York during the afternoon hours. Some storms may produce strong winds along with hail and brief downpours.
Once the front moves through, high pressure builds back in with sunshine and dry conditions for the first half of the upcoming week. Another front will move through on Wednesday with a chance for some additional showers and thunderstorms before stalling out across the region. Exactly where that front stalls out will be critical, as waves of low pressure are expected to ride along it, bringing chances for some much-needed rainfall. If the front stalls along the southern New England coast, then some significant rainfall could fall across much of New York and Southern New England. If the front stalls out across the Mid-Atlantic states, then the heaviest rain would be focused there, and not where it is needed most. The forecast models are split on where the front will stall out, so it’s too early to get a good idea of which idea might be correct. However, if history is any indication, then expect the front to stall out to the south. Droughts feed on themselves, which leads to an old forecasting rule of thumb – “When in drought, leave it out”.
Normally, when the Northeast experiences a drought in the summer, it ends with heavy rainfall from a tropical system, or the remains of a tropical system that made landfall elsewhere. Tropical Storm Earl is moving into eastern Mexico this evening, but it is not expected to have any impacts on the US. However, there is a cluster of thunderstorms in the northeastern Gulf of Mexico that needs to be watched. While development of a tropical cyclone is not expected over the next few days, the system could slowly organize. The main impact from this system will be heavy rainfall across the Gulf Coast, especially in portions of Florida and southern Georgia. Some models are showing the potential for 5-10 inches of rain over the next few days. This will almost certainly lead to flooding in parts of the region.
The ideal situation would be for some of this moisture to be drawn northward and ride along the front into the Northeast, finally bringing significant rainfall to the area. While this is a possibility, it does not seem like a likely scenario at this point. In fact, some of the models show the moisture remaining in place across the Northern Gulf of Mexico right through the week, with heavy rain and thunderstorms continuing across the region.
With the end of another month comes another time to examine what drove the weather during the month and see if any climate extremes were set for the month of July.
July’s average temperatures were above normal from the Northeast into the Southeast and westward into southern portions of the West. On the contrary, below normal temperatures occurred in the North and into portions of the Middle Mississippi Valley. One of the main features that helped to create temperature extremes was a strong high pressure system that slowly moved across the US from the west to the east from around the 22nd of the month to around the 27th of the month. Above normal temperatures were observed across a large portion of the US during that time frame and multiple areas received heat wave(s) as a result. Also record max minimum temperatures were at least forecast for many places along the eastern seaboard from the 25th to the 28th indicating the intensity of the humidity working into the area at the time (as mentioned in a previous post). Furthermore, record July average maximum temperatures were observed in much of the Southeast and even Reading, Massachusetts and Bangor, Maine saw record average maximum temperatures for the month of July.
On the contrary, below normal temperatures were observed especially in the Northwest. This appears to be a result of an upper level low that originated as energy from a low pressure system in Central Canada, but then slowly meandered west into the Pacific. Upper Level low pressure systems often have cooler weather associated with them as a result of cloud cover and, occasionally, precipitation that has a marine origin. Perhaps Canadian cold air outbreaks contributed to the below normal temperatures, as well, as cold fronts passed by.
Also, average monthly meridional flow, or only the north-south component of the wind, shows above normal strength or southerly flow into the Gulf Coast at the same time that below normal strength or northerly flow occurred into Northeast and just west of the Pacific Northwest. This would help to explain most of the temperature anomalies. However, the northerly flow into New England paired with above normal temperatures doesn’t add up. We did end up with above normal temperatures in the Northeast so northerly flow paired with above normal surface temperatures seems to indicate a setup conducive to severe weather. There were numerous days in July that had severe weather in July so that seems like a likely explanation.
Above normal precipitation was observed from the Pacific Northwest into the Middle Mississippi Valley. Severe weather, including a squall line and other severe weather in the Middle Mississippi Valley during the week between the 16th and the 23rd seemed to contribute to above normal precipitation there. The Northwest was once again affected by the nearby upper level low with additional precipitation. At the same time, drier than normal weather was observed in southern portions of the United States as well as in the Northeast during the month of July. As a result the drought activity picked up in the Northeast and the chances for severe weather did not chip away at the increasing drought. Also, the increasing drought continued to make it harder to chip away at the drought as lower soil moisture content makes it harder to rain higher amounts.
Average placement of pressure systems seems to indicate the EPO/PNA pattern controlled the month as a low pressure system in the Northwest and a high pressure system in the Southeast indicates a negative PNA/positive EPO pattern. That’s what the analysis shows for the end of the month as the EPO and PNA trended towards their positive and negative phases respectively. The average temperature for the month alludes to the fact that the negative PNA was controlling the month by having the placement of above normal temperatures matching what the signal for a negative PNA contributes to.