A strong southerly flow will usher an unseasonably warm air mass over much of the United Kingdom, Ireland and western Europe this week.
Temperatures across much of Wales and England will average 4-8 C (7-15 F) above normal. Highs in London will range from 28-31 C (83-88 F) through Saturday.
Madrid skyline on a hot day. (Victor Pelaez/iStock/Thinkstock)
A potent storm system arriving over the weekend will bring a threat for widespread rainfall but do little to end the current heat across the United Kingdom.
This storm system will also threaten the British Open Championship at Royal Liverpool taking place through Sunday. While Thursday was rain-free, the threat for delays will increase because of rain and lightning on Saturday with a lingering threat for a shower or thunderstorm on Sunday.
Much of France, including Paris, will also feel the heat this week. The combination of unseasonable warmth and increasing humidity will make it feel over 32 degrees (90 F) during the hottest time of the day in the capital city Friday and Saturday. Friday will be the hottest day of the year so far with high temperatures climbing to 34 C (93 F).
Strong thunderstorms will be possible late Saturday into Saturday night as cooler air invades from the northwest. These thunderstorms will be capable of producing heavy rain, damaging winds and small hail.
The high on Sunday will only be around 24 C (75 F) in Paris with a few lingering showers and perhaps a thunderstorm.
The heat has already built across Spain, but the threat for rain and thunderstorms will remain farther north across France and the United Kingdom.
Madrid experienced its hottest day of the year for the fifth straight day as temperatures reached 38 C (101 F) on Thursday.
Temperatures will fall only a degree or two on Friday before more noticeable cooling arrives for the weekend.
A new tropical threat may loom for the Caribbean and North America in the not-too-distant future, while eight more weeks remain in the Atlantic hurricane season.
The greatest danger of flooding across the central United States will unfold in western Texas, where downpours will be most persistent into Monday.
Fall air has finally arrived in the northeastern United States and may yield the first frost of the season in parts of the region this weekend.
Typhoon Megi will continue to strengthen before threatening lives and property across Taiwan and eastern China this week.
Gusty winds will accompany a push of chilly air across the Great Lakes from Sunday night through Tuesday.
The first windstorm of the season could blast the northern United Kingdom around Tuesday as Karl arrives.
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Water froze one-half of an inch thick.
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Greatest September rainstorm with 5.42 inches in 24 hours at L.A. Floods killed 45; $2 million damage.
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Record late September heat wave seared Southern CA for a week. L.A. hit 105 degrees; San Diego hit 97 degrees.