Here are three hypothetical cases showing how a sea breeze can infuence your decision to fly or not.
Let us start with a couple of constants for these cases:
- The unadulterated sea breeze direction is from 160.
- There is a 30F gap between the ocean water and inland temperatures (large gap)
- The launch site is 20 miles from the ocean.
Case 1 - Inland winds are from 270 at 2kts (light winds from an uncomplementary direction)
Result
1 - A sea breeze could easily form with a wind speed of 12kts, moving
20-50 miles inland, overriding the inland winds with an almost unchanged
sea breeze direction and speed.
Case 2 - Inland winds are from 270 at 12kts (strong winds from an uncomplementary direction)
Result
2 - While a sea breeze could form, its impact on the inland winds would
be to slow and moderately shift their direction. The resultant winds
could become 220 at 4kts. The inland distance of travel for the sea
breezed might only be 10-30 miles before dissipating.
Case 3 - Inland winds are from 140 at 7kts (moderate winds from a complementary direction)
Result 3 - A sea breeze could form, and the resultant winds inland could become 150 at 12kts, again moving inland 20-50 miles.
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How can you tell if a sea breeze will form or has formed?
The
weather service is getting better at predicting whether there is a
chance of a sea breeze forming. Additionally there are tools available
on the internet that let you see, if in fact a sea breeze is starting,
and track its progress.
- One of these is Intellicast Base Reflectivity view
which updates approx. every 10-15 minutes. CAUTION: always look at the
date and time stamp (given as GMT) on the screen images to ensure they
are relatively current.
Below, is an explanation and images of
an actual sea breeze captured over a 4-5 hour time period, along the New
Jersey coastline using the Intellicast tool.
First a marked up image showing what to look for:
Generally,
a sea breeze coming inland to Central New Jersey, as shown here, will
flow from the southeast. This can alter the direction and speed of the
pre-existing ambient winds.
On this day, all the elements necessary for a strong sea breeze were present:
- High ambient temperature
- Cold ocean temperature
- Winds inland being out of the sought at around 5mph
The following animated images show the movement of the sea breeze from formation to breakdown.
Note:
as the afternoon wore on, a storm system moved in, causing the ambient
winds to become stronger and originate from the west. This was enough
to halt and neutralize the sea breeze before it marched 50 miles inland.
Click on any of the pictures below for an action view, in a new window
Watch the ragged line showing a sea breeze starting to form along the central to southern coast of New Jersey.
This image shows the sea breeze line taking shape and moving inland away from the coast.
Now the sea breeze is very visible and moving further away from the coast.
Weather
system moving in changed direction of the inland wind from the south to
coming from the west, with increased wind speed. This resulted in a
stopped and neutralized sea breeze.