Today is the summer solstice in the Northern Hemisphere. On the solstice, we also hit the longest day of the year. From here on out, the days begin to get shorter. The word solstice comes from the Latin words for "sun" and "to stop," due to the fact that the Sun appears to stop in the sky. The Sun is directly overhead at its most northern point at "high-noon" on the summer solstice which will officially occur at 1:16PM this afternoon EDT, creating more sunlight in the Northern Hemisphere on this day then any other.
The sun will be passing directly over the Tropic of Cancer today (as opposed to the Tropic of Capricorn). To remember which season marks Summer vs. Winter for these 'Tropic Latitudes" for the Northern Hemisphere, just think 'skin cancer' and you have summer. For those with a birthday in January or late December, Capricorns. Today also marks the beginning of Winter in the Southern Hemisphere.
However, it is not the warmest day of the year in the broader sense. It normally takes approximately 30 days for the heat from the sun to work through the atmosphere, so there is a time lag, and thus July is typically the hottest month for most of North America. Additionally, it can take 60 to 90 days for the oceans to respond which means they are at their warmest in late August through early October; and such, we have the peak of the hurricane season in early September. This rule of thumb normally does not apply to Florida where the hottest days are found in late May through through first 3 weeks of June for the most part.
During spring and fall, the earth's axis is pointing sideways so both hemispheres have moderate weather and the rays of the sun are directly overhead the equator. Between the Tropic of Cancer and the Tropic of Capricorn (23.5° latitude south) there really are no seasons as the sun is never very low in the sky so it stays warm and humid ("tropical") year-round. Only those people in the upper latitudes north and south of the tropics experience seasons
FORECAST: Dry along the east coast today , in fact...most everywhere over East Central Florida. Only portions of South Florida and the western interior will see isolated showers and storms today at best. High pressure in the mid-levels is moving off the Florida NE Coast today, which will place all of the east coast in easterly return flow with an earlier East Coast sea breeze onset. Unfortunately, this could also mean it will get hazy today. Smoke from the fires that have continued to smolder, impressively so yesterday, had been offshore the past two days...but with the circulation to be in place today, it could come in the back door from offshore. It could get most hazy behind the sea breeze boundary under the sinking (and quite dry) air. Hopefully the worst of it will remain suspended above the sea breeze boundary, but even so...there should be some entrapped in the mid-levels.
WEDNESDAY: Not much of a change in regard to the immediate east coast...someone could get some showers tomorrow...more toward North Florida...as a big change in the pattern toward what looks will be the Florida Wet Season which will begin on Thursday and more likely Friday through the week end when overall precipitable water values will rise to 2.00" inches for a few days.
THURSDAY: The trend has been on for showers and eventually thunderstorms to form toward the west side a progress slowly (all day long to do so) toward the East Coast mainly north of West Palm Beach or perhaps Vero Beach. Much greater overall atmospheric moisture will circulate from the tropics in advance of an approaching mid-level trough once the mid-level high pressure area now in place has moved further east and out of the way. Trends have been favoring mostly the north half of the peninsula to receive the benefit of this moisture at first...working into parts of South Central late in the day. It is possible that some heavy thunderstorms will impact mainly the East side of the state from near Sebastian Inlet to Jacksonville, reaching the immediate east coast east of I-95 after 7 or 8pm. Things could change, and there is the possibility that the immediate east coast south of Cape Canaveral (if even) will not yet see the rain, but the trend has been pretty consistent for the Cape area to get some heavier storms toward to just after sunset which could linger through late evening.
FRIDAY: Better chance of a broad expanse of rainfall across the state, and suspect official forecasts will up the ante on the 'chance of rain toward 50 or 60%'...before all is said and done. It appears that the only location in the state that will not get bigger rains will be just where it is needed the most (extreme SE Florida).
SATURDAY/SUNDAY: more rain chances in the offing, perhaps into Monday.
RAIN TYPE: Do not expect severe thunderstorms during the transition. Air temperatures aloft will be warm in comparison to earlier this year, since the flow aloft will be guided more by placement of high pressure ridges rather than low pressure troughs. This is a totally typical summer-type, wet season pattern that will persist all in all through the remainder of the year until fall...last year, we never once had any cold shots of air aloft...and thus, less storms..hardly and strong/severe storms.
Going into early next week the pattern eventually will shift from afternoon/evening storms to an onshore, persistent flow (moist) which would lead to showers just about anytime. Southeast Florida could end up getting their most beneficial rains during this time.