February 2012 the globe's 22nd warmest; record Hawaii hailstone confirmed
February 2012 was the globe's 22nd warmest February on record, according to the National Oceanic and Atmospheric Administration's National Climatic Data Center (NCDC). Global temperatures were the 15th warmest on record according to NASA. It was the coolest February since 1994, and the coolest month, relative to average, since January 2008. The relatively cool temperatures were due, in part, to the on-going La Niña event in the Eastern Pacific, which has brought a large amount of cool water to the surface. February 2012 global land temperatures were the 37th warmest on record, and ocean temperatures were the 12th warmest on record. Global satellite-measured temperatures for the lowest 8 km of the atmosphere were colder than average, the 7th or 13th coldest in the 34-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH). February temperatures in the stratosphere were the coldest on record. We expect cold temperatures there due to the greenhouse effect and to destruction of ozone due to CFC pollution. Snow cover during February varied dramatically depending on which hemisphere you were in. Eurasia had its third largest snow cover extent in the 46-year period of record, while North America had its fourth lowest. As seen in Figure 1, much of North America and Siberia were much warmer than average, while Europe was considerably colder than average. Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of February in his February 2012 Global Weather Extremes Summary.
Figure 1. Departure of temperature from average for February 2012. Image credit: National Climatic Data Center (NCDC) .
La Niña weakens, almost gone
A borderline weak La Niña event continues in the equatorial Pacific, where sea surface temperatures were approximately 0.5°C below average during February and the the first half of March. NOAA's Climate Prediction Center forecasts that La Niña will be gone by the end of April. The majority of the El Niño computer models predict neutral conditions for this fall, during the August - September - October peak of hurricane season, though 32% of the models predict an El Niño will develop. El Niño conditions tend to decrease Atlantic hurricane activity, by increasing wind shear over the tropical Atlantic.
February Arctic sea ice extent fifth lowest on record
Arctic sea ice extent was at its fifth lowest extent on record in February, according to the National Snow and Ice Data Center. Continuing the pattern established in January, conditions differed greatly between the Atlantic and Pacific sides of the Arctic. On the Atlantic side, especially in the Barents Sea, air temperatures were higher than average and ice extent was unusually low. February ice extent for the Barents Sea was the lowest in the satellite record, due to air temperatures that ranged from 4 - 8°C (7 - 14°F) above average at the 925 mb level (about 3000 feet above sea level). In contrast, on the Pacific side, February ice extent in the Bering Sea was the second highest in the satellite record, paired with air temperatures that were 3 to 5 degrees Celsius (5 to 9 degrees Fahrenheit) below average at the 925 mb level. Satellite sea ice records date back to 1979.
Figure 2. Record-setting hailstone from the Hawaii 'supercell' thunderstorm that hit the Hawaiian island of Oahu on March 9, 2012. Image credit: NOAA/National Weather Service.
Huge hailstone sets Hawaii record
A hailstone with the diameter of roughly that of a grapefruit that hit Oahu on March 9, 2012, has been confirmed as the largest hailstone on record for the state of Hawaii, according to NOAA. The record-setting hailstone was dropped by a “supercell” thunderstorm on the windward side of Oahu. There were numerous reports of hail with diameters of 2 to 3 inches and greater. Hail the size of a penny (diameter of 3/4 inch) or quarter (diameter of one inch) has been reported in Hawaii only eight times since records began, and there is no record of hail larger than 1 inch in diameter. Hail the size of golf balls and baseballs can only form within intense thunderstorms called supercells. These supercells need warm, moist air to rise into progressively colder, drier air, as well as winds changing direction and increasing speed with increasing height off the ground. For both sets of conditions to exist at the same time in Hawaii is extremely rare, but that did occur on March 9. Conditions that day were ideal for a supercell to form, and the storm looked very much like supercell thunderstorms common in the Central U.S. during spring. Supercells can also produce tornadoes, another rarity in Hawaii. The same hail-producing supercell produced a confirmed EF-0 tornado with winds of 60-70 mph in Lanikai and Enchanted Lakes on Oahu.
Jeff Masters
Reader Comments
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Assessing the Climate Footprint of Tropical Cyclones: Pertinent Players or Irrelevant Pawns?
I wouldn't count on it, the GFS shows a very lackluster severe potential for next Monday.
That's softball sized hail, guys.
SHOWERS WILL AGAIN BE POSSIBLE ACROSS THE AREA TUESDAY AND
WEDNESDAY AFTERNOON MAINLY DURING PEAK HEATING HOURS. FROM MIDWEEK
ON...LONG TERM MODELS DIVERGE QUITE CONSIDERABLY. THE ECMWF
DEPICTS A CUTOFF H5 LOW ACROSS THE NORTHERN GULF COAST AND SLIDES
IT TO THE SOUTHEAST KEEPING A GOOD FEED OF MOISTURE ACROSS SOUTH
FLORIDA THROUGH THE END OF THE WEEK. THE GFS ON THE OTHER HAND
KEEPS THE LOW IN THE FORM OF A SHORTWAVE AND KEEPS IT WELL TO THE
NORTH. THIS MORE DYNAMIC SOLUTION SWINGS A COLD FRONT ACROSS THE
FLORIDA PENINSULA THURSDAY AFTERNOON. ATTM DID NOT MAKE TOO MANY
CHANGES TO THE EXTENDED PERIOD...AWAITING BETTER LONG TERM MODEL
CONSENSUS.
GFS
CMC
EURO
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0332 AM CDT FRI MAR 30 2012
VALID 021200Z - 071200Z
...DISCUSSION...
ON MON/D4...A CUT-OFF LOW IS EXPECTED TO ENTER THE SRN PLAINS...BUT
MODELS ARE IN DISAGREEMENT WITH THE SPEED AND LOCATION OF THIS
FEATURE. THE GFS REMAINS MORE PROGRESSIVE BRINGING THE LOW EWD ALONG
THE I-40 CORRIDOR AND INTO OK BY TUE MORNING...WHILE THE ECMWF
STALLS THE SYSTEM OVER W CNTRL TX. WHILE SUBSTANTIAL BOUNDARY LAYER
MOISTURE AND INSTABILITY WILL BE IN PLACE...THE PREDICTABILITY OF
THIS SYSTEM IS TOO LOW TO DELINEATE ANY SEVERE AREAS. REGARDLESS OF
WHICH SOLUTION IS CLOSER TO REALITY...THE SEVERE EVENT DOES NOT
APPEAR TO HAVE MUCH HIGH END POTENTIAL.
FROM TUE/D5 ONWARD...THIS LOW WILL EITHER MEANDER EWD ACROSS THE
GULF COAST...OR MERGE WITH A NERN U.S. TROUGH AND PHASE ACROSS THE
TN VALLEY REGION. ONCE THIS SYSTEM EXITS...THE PATTERN SHOULD BECOME
LESS ACTIVE WITH THE POTENTIAL FOR A REX-BLOCK PATTERN TO SET UP
D7-D8.
We may have already seen our peek in severe wx this season. It seems to me that we are seeing a similar set up to what we've seen in 2009 for the April thru June time frame (severe wx wise). It just seems that the theme lately has been Rex Blocks and numerous cut off of lows.
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
333 AM EDT FRI MAR 30 2012
NJZ009-010-020>022-027-PAZ060>062-067>069-301300-
/O.CON.KPHI.FZ.W.0003.000000T0000Z-120330T1300Z/
HUNTERDON-SOMERSET-OCEAN-CUMBERLAND-ATLANTIC-
SOUTHEASTERN BURLINGTON-BERKS-LEHIGH-NORTHAMPTON-CHESTER-
MONTGOMERY-BUCKS-
INCLUDING THE CITIES OF...FLEMINGTON...SOMERVILLE...JACKSON...
MILLVILLE...HAMMONTON...WHARTON STATE FOREST...READING...
ALLENTOWN...BETHLEHEM...EASTON...WEST CHESTER...NORRISTOWN...
DOYLESTOWN
333 AM EDT FRI MAR 30 2012
...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM EDT THIS MORNING...
* TEMPERATURES...IN THE LOWER 30S WITH SOME UPPER 20S IN THE
NORMALLY COLDER LOCATIONS INCLUDING THE PINE BARRENS IN NEW
JERSEY.
* IMPACTS...DUE TO AN UNUSUALLY WARM WINTER AND EARLY SPRING...
THE GROWING SEASON HAS BEGUN AROUND THE REGION. ANY VEGETATION
SUSCEPTIBLE TO FREEZING TEMPERATURES OVER A PERIOD OF THREE OR
MORE HOURS WOULD BE AT RISK.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS WILL KILL CROPS AND OTHER
SENSITIVE VEGETATION. IF POSSIBLE BRING TEMPERATURE SENSITIVE
VEGETATION INDOORS AND PROVIDE PROTECTIVE COVERING FOR OTHERS.
&&
$$
Really? I'm a little surprised that it isn't a requirement for a met. Both numerical analysis and numerical methods were met requirements when I went to Plymouth State if I recall correctly.
My advice would be to take it. If you plan on doing any sort of computational work (modeling, etc.) or intensive data analysis, it will give you a solid grounding in the essentials, including some error analysis.
Levi responded to the tropical cyclone aspect of your post. I'll address the Gulf Stream part. :)
I'm not really sure I've ever heard of the THC keeping western Europe warm, however it is well known the the THC is what keeps norther Europe from turning into Alaska Link. The warmer waters moderate the effect of being at such a high latitude. More recently, the warmer waters (and altered weather patterns) have been acting like a blow torch to ice formation in the Karents causing a large reduction in arctic ice formation in the region.
A cooling Gulf of Guinea sends the ITCZ or Monsoon Trof further north into the Sahel.
Cool...I'm over at Clearwater Campus
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