By WeatherFlow meteorologist Shea Gibson written on 3/29/20.
Lots of folks on the water (and meteorologists alike) saw a fog bank encroach the coastline late Friday afternoon and into the evening. It was rather peculiar because we generally would see a marine layer (fog) build along the coast as ambient air temps surpass the water temps by a substantial amount through the day, or leftover from nighttime into the morning. This fog bank; however, was one that crept up on us in the afternoon and we can definitely can understand how legendary nostalgic maritime vessel and pirate stories would have started.
The setup at the coast was a classic warm pattern for the SE Region with Atlantic High pressure bringing somewhat moderate SW/SSW Sea Breezes into the coast. As with all successful Sea Breeze circulations, humidity was very low at the beaches and just inland. Sea surface temps (SST’s) were in the mid to upper 60’s and ambient air temps topped out around ~86°, making a difference of around 14-16 degrees. This is not very much of a difference to create a marine layering along the coast, but rather would be a very shallow surface layer if anything.
Here is a snapshot is what the cooler shelf waters were on that day. You can see the Gulf Stream offshore as the warmer body of water in the low 80’s.
At some point in the afternoon, a cool and stable pool of air managed to develop over the shelf waters. It was curved around the Atlantic High pressure and was nudged into the coast along the Sea Breezes. Here is what I caught off the GOES16 visible imagery:
To many on the water and beaches that day, it came as quite a surprise. Not only did it make air temps drop several degrees, it also eventually killed off the winds by several knots as this pool of stable air was injected into the Sea Breeze circulation.
Here are a few pics of the area from the locals:
This one from Daniel Cubberly Goldston at Kiawah Island just south of Charleston.
This one from Andy Lassiter at Folly Beach:
And this one from Eric Angermeier at the back marshes of Folly:
You can see the air temp drop starting just after 4PM inside the Charleston harbor at our Fort Sumter Front Range Light.
And here are the winds dropping after the cool air injected itself into the Sea Breeze circulations. It was not immediate, but rather gradual. This data was pulled from our weather stations at both the Isle of Palms pier and the Folly Beach pier.
So we already know that marine layering can hamper speeds and cause Sea Breeze decoupling where onshore flow is occurring off the cooler waters, but what about that magic number where this complication does not happen anymore? After watching SST’s and Sea Breezes for several years, I have pinned it right around 76°+ for the Charleston area when waters actually start feeding the instability factor (instability = more wind). For an additional reference point, in tropical system development we generally see 80°+ as being the fuel from the ocean surface.
As always, we are life-long students to this science and always watching, researching and sharing what we learn. Stay safe and cheers from us at WeatherFlow!
SE/East Coast Wind Forecasting
New Station Project/ Outreach
Facebook: Shea Gibson – Meteorologist
by Kate Looney with imagery by Kate Looney and Mike Godsey
The first major coastal storm of the fall season took shape over the Chesapeake Bay on October 16th with a swath of moderate to strong E/SE winds building ahead of the storm and a powerful W/SW blast shaping up on the backside of the system. Tens of thousands of people lost power and new surface low pressure records were set for October in several locations across Rhode Island, Massachusetts (including Boston), New Hampshire, and Maine (more on this later).
Let’s take a look at how the system evolved.
Looking at the surface analysis progression (courtesy of NOAA’s WPC), we see the beginning of a nice double-barreled low pressure system building at the surface at 2PM EDT the 16th across the Chesapeake Bay. This was in response to a splitting southern branch of the jet stream high above the surface (top left image).
By 00Z (8PM EDT, top right), the surface cold front has caught the warm front across the Delmarva region and a second occlusion has formed along the deepening coastal low. Moderate to strong SE to E winds were building from the Delmarva region all the way up into Massachusetts in response to the continued strengthening of this low.
The low continued tracking up the New Jersey coastline and up into the Rhode Island/Cape Cod area by 6Z (2AM EDT, bottom right) before rotating back northwestward just west of Boston as it rapidly “bombed out”, or strengthened quickly over a short period of time. The two different areas of surface low pressure eventually evolved into one exceptionally strong October surface low, hence the records set for minimum surface pressure.
Here’s a look at the water vapor imagery overlaid with surface pressure as the coastal low continues deepening from about 2AM EDT to 7:30 EDT the 17th:
WeatherFlow’s Carson Beach sensor reported a surface low pressure of 973mb just after 3am local time on the 17th as the low passed between Boston and Worcester, Massachusetts.
As this low moved up west of Boston, the occlusion eventually began to choke the system. Eventually, the low slowed down and began to weaken across New Hampshire/southern Maine.
As a result, a large swath of very strong W to SW winds pummeled much of the Mid-Atlantic and especially the Northeast this morning, only finally easing up late this afternoon. The image below is an areal snapshot of WeatherFlow sensors across Rhode Island and Massachusetts about 10:30EDT with many sites maintaining near or above tropical storm force averages a good portion of the day and even stronger gusts well into the afternoon hours.
Another areal view of strong W/WSW winds with gusts noted as of 3:30 EDT. Notice the gusts into the 50s/60s through eastern Long Island Sound, coastal Rhode Island, and southern Cape Cod waters.
The images below show the dramatic drop in surface pressure from WeatherFlow’s Carson Beach sensor in the Boston area from Wednesday to Thursday, hence the meteorological distinction of a “bombing” low (greater than 24mb drop in 24 hour period):
WeatherFlow’s Flow Map product nicely shows the cyclonic spiraling of surface winds into this low overlaid with surface wind observations. The surface low tracked right across the Concord, New Hampshire area around 8AM EDT, which also set a new record October low pressure of 973mb pending NWS verification.
Also of note about this storm-this post has thus far avoided the term “Nor’Easter” in association with this system. Although it did maintain a northeastern track as coastal lows often do during the fall and winter seasons, a classic Nor’Easter is named because of the strong NE winds that develop ahead of the system across the Mid-Atlantic and Northeastern US. In this case, due to the track of the coastal low much closer in to the coastline, winds ahead of the system remained out of the SE to E. Really it’s a moot point though as no matter what you call it, it was definitely a record-setting system for October.
Bottom line, the track of the low plays a big role in how the wind field evolves for a very large area.
Because of the necessity in an accurate forecast track and it’s implications on the wind field, these systems can be quite tricky to forecast on days when adventurous sailors, surfers, and kiters may want to take advantage of strong winds. WeatherFlow meteorologists may include a statement like “forecast remains subject to change/highly dependent on track of the low/winds may drop quickly” to convey the uncertainty in these situations until a more clear track is known. Large swings in speed and direction can happen over the course of an hour or two for areas where the surface low passes overhead or close by, somewhat like the calmer winds in an eye of a hurricane.
This image below from WeatherFlow’s Kalmus sensor in Cape Cod highlights the potential for rapid changes in winds: You can see around 1AM that winds begin to drop out to mid 20s briefly after building to nearly 50mph. This is followed by a steady build and almost 180 degree reversal in direction from ESE to WSW due to proximity of the surface low swinging by just the west. Quite the variety in speed/direction over a few hours!
A more dramatic example can be seen below at Weatherflow’s Pt. Judith, Rhode Island sensor, where winds went from 50mph to near 10mph in about an hour! Steady veering to the SW/WSW ensued with a quick build back to very strong upper 40s/low 50s with passage of the low.
You may have noticed that the weather has gone a bit bonkers this year for much of the west coast. And, no, you’re not alone in having this impression since the data backs up your impression. And, no, it is not Global Weirding, at least not directly.
This year the Gorge had snow on the ground for almost a month in late winter. Then it had a crazy long May heat wave. Then unending mid 30’s wind in June. And currently a long period of weird clouds and wind.
In the San Francisco Bay Area we have seen long periods of eddies and southerly winds along the Bay Area coast with the beloved NW winds AWOL. The frequent southerly flow has been a delight for kiters and windsurfers at Bay sites north of the Bay Bridge. But for Crissy, the coast and much of the Peninsula it has been a wind drought.
So what is behind all this Gorge and San Francisco weirdness? Blame El-Nino!
You may have noticed that it is a weird summer with the wind cycling between WSW eddy wind and, more rarely, out of season very strong NW ocean wind. Why? El Nino has enhanced Pacific ocean warming towards the Artic. Such warmth encourages a larger elongated North Pacific High to span the waters from west of Hawaii into Alaska to the tip of Baja. <b>In normal years the North Pacific High develops an inland kink over the Pacific Northwest as systems pass to the north which makes the Gorge blow. But in an El Nino year, the average storm track is further south. This makes the high pressure kink over far Northern California. And as you can read below…. this leads to an eddy.</b>
Every few years, the El Nino-Southern Oscillation – a warming of tropical Pacific sea-surface temperatures linked to a slowing or even reversal of the normally easterly trade winds – begins. El Nino is tied to a host of changes to the normal climate of the west coast. If you live in California you know that a strong El Nino brought more rain than normal to California this winter.
However, El Nino’s effects in the summer are not as well understood, but, this year, we are seeing a doosy. El Nino increases westerly winds south of the North Pacific High. Those west winds have often been stretching the North Pacific High north and sout . That is why the forecast has sometimes noted that the NPH stretched up to the Gulf of Alaska. Those El Nino westerly winds have sometimes crippled the North Pacific High southern flank disrupting Hawaii’s trade winds. [this would be a good place to show a figure from the last couple of days with the hilariously northward displaced NPH with its sad southern flank under attack by a subtropical lows.
In the San Francisco Bay Area the distorted NPH is doing several things.
First, it’s weakening northerly winds at the coast as pieces of the NPH are pushed east onto shore.
Second, it’s creating an opening for unusually sharp upper-level troughs to pass through the region which keeps temperatures far cooler than normal and changes the nature of marine layer clouds in the Corridor, giving them more height and picking them up off the floor of the Gorge.
Third, those same upper troughs have limited the heating of the waters flowing into the Columbia hence the cool waters for the July 4 holiday.
Fourth, it’s keeping surface pressure gradients unusually strong in the Near and Far East, making for many windy days at a time of year when that should become rarer.
Fifth, finally, it’s displacing the Columbia Basin low east of its normal hangout, causing winds just above the eastern Gorge to, more often, come from the WNW, rather than the WSW – this is making Maryhill and The Wall often weak at the launch sites while enhancing Rufus winds.
With low swell already hitting the beaches and UP AND DOWN winds sometimes hitting 18 mph at the campground sensor it is clear that El Norte winds will develop just outside today.
But to get those winds to the beach we need a local pressure gradient to the Los Planes Valley and the valleys near Los Barriles.
At dawn, there are lots of low-level gray clouds over the region as indicated by the yellow arrows. Notice how those clouds fade away north Isla Cerralvo. So those clouds should not be in an issue. But the wispy upper-level clouds streaming towards us may be an issue if they thicken, We need those clouds to largely dissipate to heat the valleys and product the local pressure gradient.
In the 2nd image note how the great mass of the clouds are to our south. That is encouraging. The second image shows that most of the low-resolution models have the clouds mostly clearing. These low-res models are not very useful for forecasting local winds but they are better for large features. So this is also encouraging.
The bottom image shows the low level water vapor. This suggests that clouds could form very easily.
Forecasting for Baja’s East Cape is hard. Many of the tools we take for granted in the USA are not available. And unlike the USA where we have lots of sensors at major kite and windsurf regions we only have one proprietary sensor in Baja. Still, I keep slowly climbing up the forecast learning curve. The last year I forecast I asked for feedback from customers about the forecast. Below are all the e-mails that came in during the next week or so. Such comments are what fuel my passion for improving the forecasts. Mike Godsey
First, don’t confuse the April-Oct. down-the-line wave riding at Punta San Carlos and the other spots on the Baja Pacific coast with Sea of Cortez kiting and windsurfing. Different season, different crowd, and scant wave riding except when there is exceptionally big swell that breaks on sandbars or reefs and provides backside wave riding like you see in my photo from Cabo Pulmo to the right.
It is always tricky to make hard and fast wind rules but after having spent a total of 60 months living in Baja over 35 years I’ll stick my neck out.
Most years the Sea of Cortez winds are the strongest and most reliable from December to mid-February so this is the best time to visit if you are a windsurfer. If you are kiting add a month or two earlier and later. If you are a foiler you don’t even need to be reading this. If California is having an early winter then strong Baja winds can start in early November. If it is an extraordinarily mild winter in California then you better hope that the fishing is good in Baja. (this relates it being a El Nino or La Nino or Neutral winter which is a topic for another blog) The best pattern is when there are well-spaced storms coming over the west coast with clear spells between each storm. For example, in Nov. 2001 an unending series of storms hit the west coast and there was little wind in Baja.
When El Norte blows, all the sites from Punta Chivato to Cabo Pulmo have wind. Don’t switch sites if it is dead at your site… all the sites are probably dead. The only exceptions to this rule are Cabo Pulmo and La Ventana. Sometimes Pulmo just does not get wind. While La Ventana can have a very light sailable wind when the other sites are dead.
Most reliable winds (from most consistent to least consistent):
1. La Ventana
2. Los Barilles
3. Punta Chivato
4. L.A. Bay
5. Punta Arena
6. Cabo Pulmo
Strongest winds and most radical conditions (locations with typically the strongest winds and the most radical locations are mentioned higher on the list):
1. Cabo Pulmo (shown in photo)
2. Los Barilles
3. La Ventana
4. L.A. Bay
5. Punta Chivato
6. Punta Arena
Baja has few of the sharks that worry sailors on the west coast and Hawaii. The only dangers here are needle fish. These sea-going daggers have been known to leap out of the water causing puncture wounds. If you see long narrow fish 1 to 2 feet long jumping out of the waves in front of you, dump into the water and water start going the opposite direction. Hitting one of these daggers when it is moving at 20 mph and you are moving at 30 mph can send its point jaw into some unpleasant places. At all of the sailing spots, longtime sailors can recount last seasons fish stories. For example, if you are at La Ventana, drop by Ventana Windsurf and ask Steve to see the X-rays of his butt. And when at Las Barilles, stop by Vela and ask Bill about his knee. The danger is small but the stories large. At times, there are man-of-war jellyfish but they are small compared to the ones in Maui. All in all Baja sailing is very mellow.
This used to be most popular Baja windsurfing destination. If you are coming down for a short trip and like at least a hint of resort life and the proximity to the Los Cabos nightlife and shopping, this is the best place to consider.
There is a wide variety of accommodations ranging from windsurfing resorts to the camping of North Beach. Please see our “Resorts and B&Bs” page for further information. The social life is hot (by Baja standards) and there are lots of stores and places to eat. Telephones, banks, RV park, gas stations await you. There are superb resort and windsurfing rental facilities. For your none windsurfing partner Los Cabos an hour to the south may beckon. There amaze of resorts, golf courses and tennis courts and shopping malls stand ready to devour money and time.
The wind is strong and side shore with very big swell close to shore. On most days, this a rugged place for complete beginners. There is often a good size shore break but once you are a few feet from shore it is no problem. Sometimes there are boats anchored in the inshore waters that you have to watch out for. If you sail southward you will find several points with breaking surf and fun backside wave sailing on larger days.
The winds are a bit stronger here than at La Vantana but when El Norte dies there can be periods of no wind. The large sweeping beach way downwind acts to catch wayward sailors but if you are more than a mile offshore you will have a long drift.
The wind alternatives range from ATVs, to world-class fishing, to exercise classes, sea kayaking, and mountain biking. From shore you can see the windline as it moves towards the land. Typically the wind picks up at a civilized hour in the late morning. In town are all the supplies you need and there are good restaurants. There is usually a satellite network so you can get the weather channel and track those Highs and Lows. There is also internet access. On a typical year the winds blow 4 or 5 days out of seven here. The wind here is fairly consistent and the swells can get very large.
This is the easiest sailing place to find. From the border, head south for several days. The highway goes right on the outskirts of town. Head into town to your destination.
Los Barriles caters more to travelers staying at windsurfing resorts and RV parks, but also offers beach camping. In addition, this area has the most complete infrastructure including supermarkets and medical care.
Baja Adventures offers a full-service Bed & Breakfast in Buena Vista — just south of Las Barilles. This nice B&B offers rates from single bunk rooms to double accommodations.
Vela Windsurf Resorts is located in front of the main launch in Las Barilles — on the beach at Bahia de Palmas, 1/2 mile east of Highway 1, on the north side of town. Vela has a reputation for having some of the best windsurf equipment, accommodations, and instructors in Baja.
If your budget or lifestyle prefer beach camping, then you may be able to camp at North Beach in the arroyo on the north of town. The status of this camping area is always in flux.
Martin Verdugo’s is on the beach at Bahia de Palmas, next to Vela. It is partially shaded area with 69 level RV sites and 25 tent sites. There are full hook-ups, flush toilets, showers, laundry, and a restaurant & Bar. The RV camping here is crowded and you are parked with almost overlapping mirrors. This is definitely not a pristine Baja experience but the sailing is great!
The Playa de Oro RV resort has 54 RV sites and 2 tent sites. It has full hook-ups, flush toilets, showers, boat ramp, laundry, and ice. You can make reservations by calling (818) 336-7494.
The northernmost of the fabled East Cape sites. South of La Paz this site was relatively unknown until the 93/94 season. 15 years ago we sailed here for a week and never saw another sailor.
The water and air are warm and the campsites are fairly protected from the wind. If your are driving down for a week or two and sailing is your only goal, this is a good place to spend your trip. The sideshore winds at La Ventana are a combination of two wind patterns. The hot, broad San Juan de los Planes valley downwind creates a local thermal wind that accelerates a mild 18 knot El Norte into fun 20-25 knot breeze. When El Norte cranks this thermal assist gives La Ventana serious winds.
The wind at La Ventana is further accelerated by the venturi effect created by Isla Cerralvo located offshore. The swells are a bit smaller than sites to the south (still they dwarf the Gorge on a 4.0 day) but they line up cleaner than Los Barriles. There is backside wave sailing at the small break at the shallow sandbar about 300 feet off the camping beach. There is another good wave sailing place at the turn of the beach to the south. None of these offer real down the line surf sailing but they are fun!
There is more interesting back side wave sailing 200 yards upwind with glassy breaking waves. There is also some wave action to the south at the bend in the beach. At all of these sites, a surfer can use a long board in the early morning before the wind kicks in. There is world class surfing 90 minutes away at Todo Santos on the pacific side but don’t expect any wind.
The sandbar in front of the camping area absorbs the shorebreak making this Baja’s best place for complete beginners. There are lots of very sharp sea urchins in the cobblestones towards the pier just downwind. Unless you are able to return exactly to one of the cleared pathways through the cobbles you should wear booties.
If you climb the small hill across the road in the morning you can see the windline and watch as it approaches the shore. A huge beach sweeps downwind acts as a parachute for drifting sailors. Even if you break down 6 miles outside you will land on the beach after drifting only about 1-2 miles. On a typical year the winds blow 4 to 6 days a week.
Be forewarned this is not a place for those looking for nightlife. There is a nice campground with water, trash pickup, showers, and somewhat funky restrooms. It can be very crowded at times. The town has no bar, no paved roads, no gas station, and unreliable phones. There are several tiny but good restaurants. There are 3 small windsurfing and kiting B&Bs. See our “Resorts and B&Bs” page for a full listing. If you are camping the prices for provisions are currently cheaper than at other Baja sites.
The reason La Ventana was so late being discovered is its isolation from Mex. 1. To get there if you are driving south, watch for the airport on the right as you near La Paz. If you are flying into La Paz leave the airport heading east and turn right when you reach Mex. 1. Once past the airport, head towards La Paz. When you get to the whaletail monument turn right and you will be on Boulevard Las Garzas (also called Agustin Olachea). Follow it to the first stoplight where you will turn right on Boulevard Luis D. Colosio. Continue out of La Paz and it turns into Hwy 286 to SJ de Los Planes.
You will know you are on the right road when you pass the Pepsi and Coca Cola bottling plants. Then the road heads to a mountain ridge. Then it drops down an endless hill into the Los Planos valley, where you will have your first view of La Ventana and the huge island offshore. If it is blowing you will see flashes of mylar sails.
As the road levels out, look for a paved road on the left going to El Sargento. Go about 7 KM to the tiny village of La Ventana. Just past the garish pink house on the left you will see Baja Joe’s, then Ventana Windsurf. A bit down the road is the campground. Captain Kirk’s is on the right about a half mile further.
Located between Santa Rosalia and Mulege at the end of a 15 mile dirt road, Chivato offers scenic high wind camping. El Norte is somewhat accelerated here by the thermal warm basin of spectacular Conception Bay to the south. There is big swell and flat water speed sailing here in strong winds. Produce and water are sometimes available and there is a resort nearby. The rumors of the camping area on the beach being closed have so far not been realized and improvements to the camping area are being made. The camping is on a firm sand beach. The launch is sandy with none of the rocks found at most of sailing sites. There is OK diving right near shore on windless days but fish are scanty near shore. The wind and water are very cool compared to the sites way to the south. The fishing is good from a kayak but nothing like the East Cape sites at this time of the year. Blowing sand can bury equipment and slow moving sailors. Typically the winds blow 2 to 3 days per week.
Chavato is easy to find. There is a sign “Palo Verde” at the entrance to the road to Punta Chivato. Once on this 15 mile dirt road follow the sign
“New Road” at the fork in the road. The road is usually it is in pretty good condition unless it has rained recently.They have reopened the hotel restaurant and are building a second restaurant near the airstrip.
Located south of Santa Rosalia there is a place with some nice waves. You need a boat to get there easily. Breaking swell with good rides.
Cabo Plumo has spectacular scenery, Baja’s only coral reef, great fishing, whale watching, kayaking, hiking, biking, diving, huge swells, and very high winds. The only element missing many years is reliable wind. There are only about 20 wind-protected camping sites and they are usually taken by long-term campers. Camping on the exposed beach in 25 to 40 knot side offshore winds is not fun and it is not uncommon for sailing gear and small dogs to be blown out to sea.
Like Jay Valentine once said, “this is a site waiting for an accident to happen.” Be forewarned Pulmo is for advanced sailors only. The winds are side-offshore and the shore break fattens up on broken masts. If you break down far outside you risk being washed up in Central America.
On the upper reef, the breaking swells are far larger and more vertical than other sites and the white water can sweep your equipment away. 500 feet downwind, the razor sharp lower coral reef has fangs that stick above the surface at all but the highest tides. Do not sail in near the lower reef since the water ranges from 4 feet to 4 inches in depth.
Killer whales are occasional visitors to the edge of the reef. On a typical year, the wind blows 2 to 3 days per week but there can be long spells with no wind and conversely, long spells with continuous wind if you’re really lucky.
Unlike the rest of Baja, the winds typically blow all night and sleeping can be a challenge. It is not uncommon for the wind to fade by mid-morning. If you sleep in a tent, ear plugs are necessary. The nearest potable water is 16 miles away. When the wind has blown in the 3.0 to 4.6 range for several days, well-organized 6 to 9 foot swells break as they hit the shallow reef beyond the point. Its like backside sailing without an impact zone.
There is spectacular kayaking at the point to the south. There is fairly good fishing but fishing is forbidden within 5 miles of the reef. There is also some of the best shallow water diving in Baja on the lower reef.
Bahia de Los Angeles
This spectacular, huge island-studded bay has a small but devoted windsurfing community. If you are driving and you only have a week in Baja, this is your first and last stop. The air and water are far colder than sites far to the south. The winds are moderate here and the passage of even relatively weak Highs to the north will bring good north winds. Despite its beauty, the only sailors that stop here are those who are unwilling to drive for one or two more days to warm water. Typically the winds blow 2 to 4 days per week. The road can sometimes be rough the last 40 miles.
L.A. Bay is easy to find. Just turn left at the well-marked turnoff and head east to the Sea of Cortez. La Gringa, as it’s called by the locals, offers good flat-water sailing from your campsite across the La Gringa Bay to the point. Camping is currently $3.00 per day per car. The beach is sand and cobblestones. Set up camp in a high spot to avoid inundation during real high tides as the water comes in from behind you via a low spot. The waters inside are great for beginners and intermediates. Advanced sailors can head outside and towards the islands. The small unattractive village offers basic supplies and some food items. The market on the right side of the road has a telephone.
Punta Arena / Playa de Los Naranges
Located at the mouth of spectacular Bahia de La Conception these sites offer mostly light wind sailing in the 5.5 to 6.0 range. Great camping and boating. You can buy fresh seafood at the fish camp. Lots of long-term non-windsurfing campers. Typically the winds blow 2 or 3 days per week.
To find Punta Arena, pass the Punta Chivato turn off. The road will continue along a coastal plain heading towards Conception Bay. As you ascend the first hill just before the bay look for a wide graded area on the left with a dirt road leading eastward. There will be a sign saying Punta Arena. Follow the road for about 4 miles. There will be a maze of dirt roads at times. Keep on the central road at the 3 way fork. If you come out at a sandy beach with lots of RVs you are at the wrong place. Your destination is about a half mile to the east but you may not be able to drive there along the beach. Head back into the desert and take the next right until you come to a sandy beach with thatched shelters with concrete pads.
I mentioned in my forecast this morning that the North Pacific High would get a bit more consolidated by this afternoon. However, today is not characterized by a consolidated North Pacific High. This first image, a surface map, shows a non-consolidated North Pacific High pressure over the Eastern Pacific which is the case today. However by the same time tomorrow, Tuesday afternoon, the forecast is for the second image, which shows a consolidated North Pacific High with isobars stacked up against our coast. The second image is more typical of the summer season.
Thunderstorm season in the Northeast US is off to an eye opening start after yesterday’s severe weather outbreak. A strong squall or line of thunderstorms passed through MA down to NJ in the late afternoon and evening bringing damaging winds and localized hail.
In the radar image below, note the gust front ahead of the thunderstorms and the high dBZ signatures (in purple) over CT as thunderstorms barrel through. Dime to golf ball sized hail was reported in parts of NY and CT.
WeatherFlow stations recorded several gusts around NY and CT exceeding 60 miles per hour!
Early Spring Cold Weather Sea Breezes in the Northeast
When some one says Sea Breeze what comes to mind???
For me its a hot day where the cooler moist air blows in off the water moderating the temps.
However, a Sea Breeze Defined by Google Dictionary is:
a breeze blowing toward the land from the sea, especially during the day owing to the relative warmth of the land.
So, we see that in reality the ambient temperature outside is somewhat irrelevant and that the primary factor needed for a Sea Breeze to occur is land that is comparatively warmer than nearby water. Enter Monday April 9th.
We have a postfrontal day with High pressure sliding down into the Mid Atlantic. Moderate WNW/W winds show across most of New England, while NW/WNW flow showing in New York and New Jersey, through the morning hours.
As High pressure settles into the region, the postfrontal flow was suggested to fade, and S/SW Sea Breezes were forecasted by the models to show in the late afternoon. Surface temps forecasted to top out in the low to mid 40’s with nearshore water temps hovering around 40F for the region.
By mid day we start to see surface temps hitting mid 40’s inland, while the beaches hover around upper 30’s or 40F, as the WNW/NW gradients are fading out at the surface. As noted, models had forecasted a modest to moderate late afternoon Sea Breeze reversal, but I was suspect due to the Cold temps forecasted.
Mild but notable temperature differences in NJ seen in these mid afternoon observations.
I had forecasted afternoon Sea Breezes but I was not convinced of their strength
Around this time I peaked around RI to see how the forecast was coming along and I noted that S facing beaches were reporting moderate WSW/SW flow while Inner Bays were showing NW/WNW flow in the low single digits, but jumpy as is typical of WNW flow across Inner Bays.
Moments later I check in and BOOM SW winds jump to 22mph at Rose Island. My AM forecast tables are a little behind and more than 6mph off so I am forced to do a special update.
So, what happened here???
As noted about NY and NJ even the Delmarva see High pressure sliding overhead essentially knocking out the WNW gradient by mid day allowing those modest to moderate Sea Breezes to pop up in the afternoon, in a somewhat typical fashion. Why then did RI see such a drastic surge???
Lets take a look at nearby soundings
WAL in the morning suggests a fairly unidirectional mid to upper level flow with milder low level flow for the Mid Atlantic that would likely be pretty easily overcome by mild some Sea Breezing.
Upton NY suggests a more defined lower and mid level NW flow backing again to unidirectional W flow in the upper levels.
So, with good return flow in both areas at the mid levels and modest Temperature gradients at the surface (even though by any standards this is still very cold) we see some moderate S/SW Sea Breezes pop up, widely.
Inner Bay Rhode Island sites are special however in that:
Geography funnels the S components of the Sea Breeze
Geography also causes mechanical mixing of the W components in the mid levels,
The above factors in conjunction with clear skies aiding in mixing causes coupling of the W/S components to cause the drastic surge in SW/SSW flow for the afternoon of 4/9.
In conclusion, this day serves to remind me, and now all of you that it doesn’t have to be warm outside for Sea Breezes to occur, and with some special additional factors in play certain areas can really crank even if the temps are in the 40’s or even less!!!