Feb 3, 2010

Storms Of January 2010

A review of the very active storm pattern during the 2nd half of January...

On January 15th, this storm entered the Gulf of Mexico and produced sustained 40+ knot winds over the waters south of Louisiana the following morning.
At 6Z on the 19th, this North Atlantic storm hit 956 mb:
The 12Z hemispheric analysis chart from the same day shows that the Siberian high has reached 1072 mb (31.66") and is approaching Mongolia.
At 3Z on the 20th, the barometer at Tosontsengel, Mongolia hit 32.01 inches (1084 mb).

January 19th was also when the 220 knot North Pacific jet stream which was mentioned in my last post hit California and sent a series of brutal storms through the southwestern US. Winds gusted to 75 mph on the Golden Gate Bridge, and to 93 mph at Newport Beach. A tornado hit Huntington Beach and was seen crossing the Pacific Coast highway. On January 20th, this 970 mb (28.64) storm set a new all time lowest barometric pressure of 28.88" (978 mb) at Medford, Oregon:
As the onslaught continued in California, enough jet stream energy had already ejected into the lower Mississippi Valley to produce a significant tornado outbreak which can be seen on the right edge of the above water vapor image. On the 21st, the last and strongest storm hit southern California as the full force of the Pacific jet stream came onshore.Incredibly, the jet stream appears to be increasing to 230 knots as it approaches the west coast:
It is rare to see dynamics of this magnitude coming into the Desert Southwest:
As an intense surface trough developed on a triple point in southern California, new all-time record lowest barometric pressure records were set at San Diego...987.1 mb (29.15") on the 21st at 1222 PM...previous record 994.6 (29.37") set on March 3 1983, at Fresno...980.0 mb (28.94") at 235 PM...previous record 985.4 (29.10") on January 27th 1916 and records going back to 1888, at Bakersfield...980.0 mb (28.94") at 1249 PM...previous record 990.0 (29.24") on February 3rd 1998 and records to 1939, at Las Vegas...29.03" (983.0 mb) at 514 PM...previous record 29.17 (987.8 mb) in December 1949 with records to 1937, at Phoenix ...29.20" (988.8 mb) at 644 PM...previous record 29.30" (992.2) set on Decenber 13th 1984, and at Reno...28.91" (979.0 mb) on January 22nd at 747 PM...previous record 29.00" (982.0 mb) on January 27th 1916 with records to 1870. Las Vegas actually broke the all-time January daily precipitation record on the 21st with just 0.89" of rain. Tornadoes hit coastal California again on the 21st including Santa Barbara and Ventura. Perhaps even more unusual, damaging tornadoes hit Blythe, CA - at the junction of I-10 and the Colorado River - and Scottsdale - a suburb of Phoenix. Equally impressive are the wind gusts of 94 mph at Ajo, AZ and 101 mph at Kingman, AZ. Tornadoes also hit Huntsville, AL and near Chattanooga, TN where temperatures were only in the low 50's and dewpoints in the upper 40's.
The series of storms that hit the Southwest from January 17th-23rd came in so rapidly that it was really a long single event. By the time it was all done many of the lower elevation mountains in California and Arizona had received over a foot of rain. The higher elevations in Arizona had up to eight feet of snow, and the Sierra Nevada Range had up to 112 inches - nearly ten feet. Flagstaff's storm total of 54.2 inches is the second highest ever recorded. As the final storm swept through the Midwest, blizzard conditions occurred in the Northern Plains.
Further upstream on the 21st, there was a beautiful 978 mb storm off the coast of Newfoundland which eventually became a 962 just south of Greenland.
On January 26th, this unusual retrograding polar high pressure cell shot straight through the British Isles and into the North Atlantic:
On January 28th, a rapidly developing storm over Texas prompted winter storm warnings (pink) from New Mexico to North Carolina, and a tornado watch for central Texas (yellow).
The storm then hit northwest Texas and Oklahoma with a mix of ice, sleet, and snow.
Southwest Oklahoma was hit with over an inch of ice while winds gusted over 50 mph. Some areas had 1/2 inch of ice then 6 inches of snow on top of it. Power outages were widespread across southwest and central Oklahoma. Another unusual feature of this storm were sleet accumulations up to 2 inches in Oklahoma and Missouri. As the storm moved east on the 29th, parts of Arkansas and Tennessee also had 1/2+ inch ice followed by heavy snow.
On January 30th, southern North Carolina was hit with up to 3/4 inch of ice.
Western North Carolina had up to 14" of snow, eastern Virginia got 18", and Richmond had 11.4". Even Delaware had one report of 11.3" from this storm. Here is a history of how this storm evolved:
February is already off to a very stormy start with this 952 mb behemoth in the North Atlantic:
And with this storm in the Pacific which hit 968 mb at 42N latitude at 12Z:
This storm is a result of a Siberian airmass descending over Japan and pushing the 540 line down to the southernmost tip of the country. Another active jet stream pattern can be expected to follow with strong southern storm track.