Right on time, the first taste of cool Fall weather will slide across the northern U.S. and into the East this week.

The culprit for this shot of cool air will be a brawny, low-temp front followed by a dip-- or trough-- in the jet stream that will develop across the northern and Central Plains on Wednesday. This will allow very dry and cold air to dive south out of the Arctic region and central Canada.

Wednesday night, clear skies will help many areas to cool off quickly, with most places seeing the chilliest temperatures since late winter or early spring.

On Thursday, the frosty air will push east from the Plains and into the Great Lakes, Central Mississippi and Ohio valleys and through the northern Appalachians. You might drag out the comforters for your beds...

Meanwhile, a southerly flow across the Midwest and Central Plains will return more seasonal, even late-summer temperatures to the region just in time for the weekend.

Now in the aftermath of Hurricane Rita and her 120-mph landfall, it’s clear that an epic evacuation saved countless lives, and destruction fell short of the Katrina-sized worries.

Some 1 million in the Texas-Louisiana region are without electricity, and some coastal towns are flooded to the rooftops, but 3 million evacuees will soon happily rush back home.

The diminished Rita continues to move faster than expected, and will bedevil the lower Mississippi and Ohio river valleys through Monday morning.

Flooding and severe weather remain a threat. Parts of the lower Mississippi Valley have already received more than a foot of rain, with another 2-4 inches of rain possible through Monday.

A Tornado Watch is in effect for parts of Mississippi, Tennessee and Alabama as severe rain bands swirl through the region.

All along the Gulf Coast, high surf will continue to pound away at the beaches—but soon powerful Rita will be described completely—and quite respectfully-- in the past tense.

Bellicose Rita continued its rapid intensification and became the 3rd most intense hurricane (based on central pressure) ever recorded in the Atlantic, Caribbean, and Gulf of Mexico. Maximum winds are estimated near 170 mph with gusts as high as 210 mph.

Over the last 10 hours, the pressure appears to have bottomed out as far as intensification is concerned, but she remains an extremely dangerous, historic, category 5 hurricane.

Forecast models indicate Rita could fluctuate in its punching power and likely drop to a category 4 hurricane. This is comparable to what happened with Katrina and Rita will likely make landfall late Friday along the Gulf Coast—near Galveston, Texas-- as a devastating, possibly catastrophic hurricane.

Numerous coastal and inland counties in Texas and parishes in Louisiana have already issued mandatory evacuation orders. President Bush issued a federal state of emergency for Texas and Louisiana late Wednesday.

Hurricane Rita, now moving into the roiling waters of the southeastern Gulf of Mexico, has strengthened rapidly into a major Category 4 hurricane with maximum winds near 135 mph. It’s quite possible that Rita could strengthen into a “Cat-5� (winds above 155 mph) hurricane in the next day or so.

Rita has entered an environment perfect for steady intensification. Conditions that will build Rita yet bigger include very warm water temperatures and little upper-level shear that often cause hurricanes to lose their powerful punch.

Several coastal communities in Texas have already issued mandatory evacuations effective. Shades of Katrina-- this is developing into an extremely dangerous and life-threatening situation.

Forecast models curve the hurricane northward slightly toward the western Gulf Coast late this week. This trend keeps the entire Texas coast, as well as the Katrina-pounded areas of Louisiana and Mississippi, threatened with the potential of a land-falling hurricane late Friday or on Saturday.

Residents of South Florida and the Keys are feeling the first affects of Tropical Storm Rita hitting the region with bands of storms and gusty winds. Rita remained a tropical storm overnight despite expectations by forecasters that it would become a hurricane before dawn on Tuesday.

Weather across the Florida Keys and southern Florida has become progressively worse overnight. Rita`s outer bands have begun to cycle across the region and this has prompted the need for a tornado watch to be issued for southern Florida.

Current forecast calls for it to have maximum sustained winds topping 110 mph by Thursday while over the Gulf. The exact track of Rita once it reaches the Gulf is highly uncertain, so all residents along the U.S. Gulf Coast are watching the situation carefully.

Mandatory evacuations for residents, non-residents and visitors have been ordered for all of the Florida Keys by local emergency officials, while officials in Miami have called for a mandatory evacuation of all mobile home parks.

Recent model forecasts have indicated that the storm center will pass just south or over the lower portion of the Florida Keys.

Hurricane hunter reconnaissance planes taking late night observations regarding Tropical Storm Rita have found a more organized and strengthening system. Pressure has lowered and maximum sustained winds are now estimated to be near 60 mph.

Tropical Storm Rita, the 17th named storm of the 2005 season, poses an immediate threat to the southern portions of Florida, as well as the Bahamas.

Forecasts call for further strengthening and Rita should become the 9th hurricane of the season as it approaches South Florida. Also, the government of Cuba has issued hurricane and tropical storm watches for the northern coast of the island nation.

Mandatory evacuations for non-residents and visitors have already been ordered in the Florida Keys by local emergency officials; Florida Governor Bush has declared a state of emergency and activated the National Guard.

A greater concern is the trend in forecast models indicating a curve in the storm northward toward the Gulf Coast late this week. This trend keeps nearly the entire Gulf Coast threatened with the potential of a land-falling hurricane, including the Katrina-ravaged areas of Louisiana and Mississippi.

Mother Nature was merciful this time around. After Katrina came in with a bang, Ophelia had little more than a whimper. The U.S. is now in Opelia`s rear-view mirror, as it continues to lose its tropical characteristics speeding northeast along the Canadian East Coast.

The current forecast calls for the storm to continue to move over Nova Scotia and lose its tropical characteristics over the colder North Atlantic waters.

Meanwhile, for all the criticism of the Bush administration's response to Hurricane Katrina, at least two federal agencies got it right: the National Weather Service and the National Hurricane Center.

They forecast the path of the storm and the potential for devastation with remarkable accuracy.

The performance by the two agencies calls into question claims by many that Katrina was a catastrophe that no one envisioned.

For example, Bush told ABC on September 1st that "I don't think anybody anticipated the breach of the levees." In its storm warnings, the hurricane center never used the word "breached." But a day before Katrina came ashore Aug. 29, the agency warned in capital letters: "SOME LEVEES IN THE GREATER NEW ORLEANS AREA COULD BE OVERTOPPED."