Why does frost on grass sometimes occur after the sun comes up?
448207
Since warm air rises and cold air sinks, when the sun comes up the warmth causes the cold air with it's frozen particles to sink, therefore landing on top of the grass. This "frost" will only last till the suns rays cause them to melt. Remember, it's still cold at ground level while the sun begins to feel warm to us.
166918
the grass is green because of the chloroplasts, which contain chlorophyll, which is essential for photosynthesis (the process by which plants convert sunlight into energy). the sky is blue because of the water droplets in the air reflecting the oceans. all the colors are the way they are because we see them that way and we decided to name them.
1181166
Air is heated by the surface of the Earth on a Hot and sunny Day.  Hot air rises.  AS it rises it expands due to lowered atmospheric pressure.  As it expands it cools and begins to decend again.  Also if the air is moist as it cools it must release the moisture (rain -or hail if it is high and cold enough.)  This begins a circulation pattern up in the middle and down outside.  Often hail will begin to fall only to be caught in an updraft and carried aloft again.  This cycle continues until the hail is too heavy for the updrafts to lift it and it makes it to the ground.  This is why very strong thunderstoms with violent updrafts produce large hail.
427340
Indoor plants are fooled as to season because of lighting inside. Length of uninterupted night compared to day light is usually what triggers cycles in outdoor plants, not frost, etc.
909696
The warm front is moving into colder air. The moisture at the leading edge of the front freezes when it hits the cold air causing snow. As the front moves through, the warm air is increasingly higher in altitude which causes the falling moisture to warm up in the form of sleet then freezing rain then rain.\n\nHope this helps!
42099
lightning occurs when warm air hits cooler air causing friction.  lightning during a snow storm is rare because warm air is harder to come by, however it happens occaissonally when a cold front follows a period of unseasonably warm weather.
57358
Sunny days are the result of high pressure systems which tend to be drier and colder in the winter. There is also no cloud cover at night to keep the reradiation in and if there is snow on the ground it is even brighter and the snow is reflecting the heat back out into space.
218041
It is quite true that soil temperatures where the living parts of the plants are during winter are not as cold as the surface temperature. That is the first fact. The second thing that comes into play is that plants produce chemicals that depress the freezing point of water and prevent ice crystals from forming and rupturing cell walls. The next factor is that many plants forms seeds or spores that are biologically inactive when conditions are not suitable for growth. This is sort of a suspended animation. It is also important to recall that plants even as large as trees have only a very small proportion of actual "living material." In a tree in winter, the cambium and rootas are "alive" The cambium goes inactive and reactivates when spring comes and the roots remain fairly dormant through winter until warming weather stimulates the cambium back to life and the roots then beginning sending sap up the tree. The question is complex as plants vary from one celled organisms to trees.
1124272
It will snow when temperatures are at 32F or below and when their is sufficient moisture in the atmosphere.  It will hail at many different temperatures when the hail rises then falls, rises with air currents then falls when gravity overcomes the aircurrents.
269206
It's the angle of the earth's rotation.  The northern hemisphere tilts away from the sun during winter, causing long periods of darkness, and towards the sun in summer, causing longer daylight hours.  At the extreme nothern latitudes, this leads to constant daylight or constant darkness at those times of the year.
538503
Because the air is less dense the higher the altitude, there are less molecules available to retain heat. Therefore the heat of the sun dissipates more readily.
876622
Spring is one of the four seasons of temperate zones, the transition from winter into summer. Astronomically, some Western countries consider spring to begin with the spring equinox (around March 20 in the Northern Hemisphere, and September 23 in the Southern Hemisphere), and ends with the summer solstice (around June 21 in the Northern Hemisphere and December 21 in the Southern Hemisphere). Such conventions are by no means universal, however. In Chinese astronomy, for example, the vernal equinox instead marks the middle of spring, which begins around the time of Lichun (around February 4). In the Irish Calendar it is counted as the whole months of February, March and April. In meteorology, it is (also by convention) instead counted as the whole months of March, April, and May in the Northern Hemisphere and September, October, and November in the Southern Hemisphere.\n\nAs in summer, the axial tilt of the Earth is toward the Sun, and daylight hours are greater than or equal to 12 hours and rapidly increasing (especially in higher latitudes). The hemisphere begins to warm significantly, causing new plant growth to spring forth, giving the season its name (see Effect of sun angle on climate). Snow (if any) begins to melt, and rivers and streams swell with runoff and spring rains. Most flowering plants bloom this time of year, in a long succession beginning even when snow is still on the ground, and continuing into early summer. In normally snowless areas, "spring" may begin as early as February during warmer years, with subtropical areas having very subtle differences, and tropical ones none at all. Subarctic areas may not see "spring" at all until May or even June, or December in the outer Antarctic.\n\nSevere weather most often occurs during the spring, when warm air begins to invade from lower latitudes while cold air is still pushing from the polar regions. Flooding is also most common in and near mountainous areas during this time of year due to snowmelt, many times accelerated by warm rains. In the United States, Tornado Alley is most active by far this time of year, especially since the Rocky Mountains prevent the surging hot and cold airmasses from spreading westward and instead force them directly at each other. Besides tornados, supercell thunderstorms can also produce dangerously large hail and very high winds, for which a severe thunderstorm warning or even tornado warning is usually issued. Often, spring storms trigger dozens of warnings, one right after the other, often simultaneously along a line hundreds of miles or kilometers long. Even more so than winter, the jet streams play an important role in severe weather in the springtime.\n\nThe hurricane season officially begins in late spring, on May 15 in the northeastern Pacific, and June 1 in the northern Atlantic. Before these dates, hurricanes are almost unheard of and even tropical storms are rare, one of the earliest ever being Tropical Storm Ana in mid-April 2003. Even in June, hurricanes are uncommon.\n\nSpringtime is seen as a time of growth, renewal, of new life (both plant and animal) being born, and of the cycle of life once again starting. It is also used more generally as the start of better times, as in Prague Spring.
11578
It's a long winded explanation - see link below.\n\n(snip)\nthe sun's heat acts almost the same as the sun's light — it passes through the air almost as though the air wasn't there.\n\nThis means that almost all of the sun's heat goes into warming up the oceans and the land it hits. As the oceans and ground warm up, they warm the air next to them, and this air warms the air a little higher up and so on. But, as you go higher, there's less and less heat available to go up, and the air gets colder.\n(snip)
997634
Dew results when water condenses out of the air as a liquid. Dew is liquid water.\n\nWhite frost resutls when water condenses out of the air direstly as ice crystals. White frost is solid water, AKA ice.\n\nBlack frost results from dew freezing. Unlike white frost black frost exists initially as water and then freezes, wheras white frost never exists in liquid form.
563373
it all depends....\n\nthe color of the sky depends on the weather...ranging from light blue to dark gray...or black at night\n\nthe color of the grass depends on how dry it is...usually it's varying shades of green but if it's really dry...then baige or brown-ish\n\nthe sun is yellow
970970
This is not a simple answer to explain in one or two sentences, so I will give it in two parts.  First, the basic reason:\n\nOvernight, the breezy conditions that was on the surface is lifted upwards.  This is because the surface becomes very stable with the loss of daytime heating.  The wind will blow above this layer of stable air until after sunrise when daytime heating will bring the winds back to the surface.\n\nNow the more detailed explaination.  In general, wind at night will decouple from the surface if...\n-there is no strong subsidence (sinking of air) like what you will find behind a strong upper level disturbance.\n-there is strong mixing (unstable airmass) in and ahead of a storms system\n-there is strong surface winds with upper level support. (winds blowing from the same direction through a deep layer above the surface)\n-near ridge or hill tops\n\n(Assuming no major weather changes are expected to occur overnight...)  During the night, with the loss of daytime heating, we lose two parameters that will keep the winds blowing near the surface.  The thermal gradient usually becomes weak and the surface cools.  A thin stable layer forms near the surface as heat rises to the top of this layer.  With time, this layer will thicken as warm air continues to leave the lower layer and replace by cooler air.  The top of this layer, you will find a temperature inversion.  This layer will seperate the higher winds that has lifted higher in the atmosphere and the very stable and near calm winds below.  Once the sun rises, the surface warms and starts to mix.  This will break the inversion and the winds will start to mix back down to the surface.  \n\nThis is also the reason why during the winter, sometimes you will find ground fog forming in a thin layer during the evening and then lifting to a low cloud or stratus right by sunrise; then "burning" off during the day.
176083
Maybe the ground temperature is hotter. Its temperature doesn't count on outside factor. The sun is just 1 factor.