//WHITE LIGHTNING DIV//AI RESEARCH//IMMEDREL//12/22/24/1700PST//
pacific ocean winter subtropical storms
Subtropical storms in the Pacific Ocean during winter are relatively uncommon but can occur under specific conditions. These storms exhibit characteristics of both tropical and extratropical cyclones, forming in a unique environment.
Formation and Characteristics
Subtropical cyclones typically form when a deep cold-core extratropical cyclone moves into subtropical regions2. They require:
Sea surface temperatures around 23°C (73°F), which is lower than the 26.5°C threshold for tropical cyclones2
Significant temperature contrast between the ocean surface and mid-troposphere
Blocking high-pressure systems that trap the cyclone in subtropical latitudes
These storms often develop:
Outside the traditional hurricane season
At higher latitudes than tropical cyclones
In areas with stronger vertical wind shear
Pacific Ocean Subtropical Storms
Kona Storms: In the central Pacific, particularly near Hawaii, winter subtropical cyclones are known as Kona storms2. These deep cyclones:
Form during the cool winter season
Can bring significant changes in wind direction and weather patterns to the Hawaiian Islands
Eastern Pacific: Subtropical cyclone formation is extremely rare in the far southeastern Pacific due to:
Cold sea-surface temperatures from the Humboldt Current
Unfavorable wind shear conditions2
However, exceptions do occur. In April 2015, a rare subtropical cyclone dubbed "Katie" formed in this region, breaking previous records for easternmost formation3. Another system, "Lexi," formed even closer to the Chilean coast in May 20183.
Factors Influencing Formation
The occurrence of Pacific Ocean winter subtropical storms can be influenced by:
El Niño events, which can increase sea surface temperatures and create more favorable conditions3
The Arctic Oscillation (AO) and North Atlantic Oscillation (NAO), which can affect cold air distribution and storm system development1
While subtropical storms are more common in the North Atlantic, they do occur in the Pacific Ocean, presenting unique challenges for weather forecasting and maritime operations in affected regions.
pacific ocean winter subtropical storms
kona low dip in the jet stream
A Kona low is a unique weather phenomenon that occurs in Hawaii, characterized by a significant dip in the jet stream. This weather pattern forms when a portion of the jet stream breaks off from the main flow, creating a separate area of closed-off, circular jet stream pattern12.
Formation and Characteristics
The formation of a Kona low begins with a southward plunge of cold air over the central Pacific Ocean2. This process involves:
A deep kink developing in the jet stream
The kink sinking southward
The low-pressure system pinching off from the main jet stream3
As a result, a subtropical cyclone forms northwest of Hawaii, outside the band of warm waters that typically fuel tropical storms3.
Effects on Weather
The presence of a Kona low can lead to several significant weather changes in Hawaii:
Wind Direction: The term "Kona" refers to the leeward or dry side of an island, typically the west side. During a Kona low, the usual northeasterly trade winds shift to southwesterly winds3.
Temperature: Cold air becomes trapped within the circular jet stream pattern, causing temperatures to plummet at the highest volcanic summits1.
Precipitation: The low-pressure system draws moisture from the warm waters surrounding Hawaii, potentially leading to heavy rainfall, thunderstorms, and even snow on the tallest peaks3.
Coastal Impact: Large waves and coastal flooding, particularly along south-facing beaches, are common during Kona low events1.
Timing and Duration
Kona lows are most prevalent during the late fall, winter, and spring months2. Unlike typical weather systems, a Kona low can linger for several days due to its cut-off nature from the main jet stream5. This prolonged presence can result in extended periods of adverse weather conditions for the Hawaiian Islands.
kona low dip in the jet stream
what causes a dip in the jet stream on pacific ocean
A dip in the jet stream over the Pacific Ocean can be caused by several interrelated factors:
Temperature Contrasts
The primary driver of jet stream formation and behavior is the temperature difference between warm and cold air masses12. A significant dip, or southward excursion, of the jet stream over the Pacific can occur when there's a pronounced contrast between:
Warm tropical air to the south
Cold polar air to the north
This temperature gradient creates a pressure difference that influences the jet stream's path2.
Atmospheric Circulation Patterns
Rossby Waves
Large meanders in the jet stream, known as Rossby waves, can cause significant dips15. These planetary-scale waves form due to:
The Earth's rotation (Coriolis effect)
Variations in atmospheric pressure
Changes in topography
When a Rossby wave develops a deep trough over the Pacific, it manifests as a southward dip in the jet stream.
El Niño Southern Oscillation (ENSO)
ENSO can significantly impact the jet stream's behavior over the Pacific:
During El Niño events, the jet stream tends to shift southward and extend further east across the North Pacific7.
La Niña conditions typically cause the jet stream to retract westward and move poleward7.
Climate Change Influence
Recent studies suggest that climate change may be altering jet stream dynamics:
Arctic amplification (faster warming in the Arctic) can reduce the temperature gradient between polar and mid-latitude regions35.
This weakened gradient may lead to a more meandering, wavy jet stream pattern, potentially causing more frequent and persistent dips35.
Atmospheric Blocking
High-pressure systems can sometimes "block" the typical west-to-east flow of the jet stream, forcing it to dip southward around the blocking pattern1. These blocks can be particularly influential over the Pacific Ocean.
In summary, while temperature contrasts are the fundamental cause, a combination of atmospheric circulation patterns, climate variability (like ENSO), and potentially climate change-induced alterations all contribute to creating significant dips in the Pacific jet stream.
what causes a dip in the jet stream on pacific ocean
direction of prevailing winds on pacific ocean
The prevailing winds over the Pacific Ocean are primarily influenced by the trade winds, which play a significant role in the region's climate and ocean currents.
Trade Winds
Northern Hemisphere: The trade winds blow from the northeast. These winds originate from subtropical high-pressure areas and move towards the equator, driving surface currents westward across the Pacific Ocean12.
Southern Hemisphere: In contrast, the trade winds in this region blow from the southeast, also contributing to westward currents. This pattern results in a convergence at the equator, creating an area known as the doldrums, characterized by light and variable breezes12.
Wind Patterns
The general direction of winds across the Pacific is predominantly from east to west, with variations based on latitude. This east-west flow is crucial for navigation and weather patterns in the region26.
In the mid-latitudes (30° to 60°), westerly winds dominate, which are influenced by larger atmospheric circulation patterns. These westerlies drive significant ocean currents such as the North Pacific Current56.
Impact on Ocean Currents
The prevailing winds directly influence ocean currents:
The North Pacific Gyre is formed by these easterly trade winds and westerlies, creating a circular flow that affects marine navigation and climate patterns across the Pacific35.
The California Current, a cold eastern boundary current, flows southward along the western coast of North America, influenced by both trade winds and westerlies35.
In summary, prevailing winds over the Pacific Ocean are characterized by northeast trade winds in the northern hemisphere and southeast trade winds in the southern hemisphere, with both sets of winds contributing to a predominant east-west flow that shapes ocean currents and weather patterns across this vast body of water.
direction of prevailing winds on pacific ocean
//WHITE LIGHTNING DIV//AI RESEARCH//IMMEDREL//12/22/24/1700PST//
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