TODAY'S FUN LINKS:
2012 Atlantic Hurricane Season
Pacific locked in 'La Nada' limbo
In Australia, Record Weather Fuels Climate Policy Process - ScienceInsider
QuikSCAT replacement funded - Democratic Underground
WEATHER HAZARDS (During The Next 24 Hours)
SEVERE WEATHER OUTLOOK
(potential for tornadoes, damaging winds, and large hail within the next 24 hours)
STRONG WINDS
(Pressure Gradient Derived)
MA....VT....NH....ME....E QC....NL....PEI....NS....NB
STRONG WINDS
(Pressure Gradient Derived)
IA....MN....W ON....C, S MB....C, S SK....AB....MT....E ID....N, W WY
HEAVY RAINFALL OUTLOOK
(potential for an inch or more total rainfall within the next 24 hours)
Scattered Locations In
C, S NL (Newfoundland Island)
(QPF 1 - 3")
WINTER WEATHER OUTLOOK
(potential for maximum temperatures below 25 deg F within the next 24 hours; snowfall in excess of 4 inches over a 24 hour period; or other frozen precipitation exceeding trace amounts)
Numerous Locations In
NS....NB....PEI....extreme E QC....NL (Labrador, northern Newfoundland Island)
(Snow; Blizzard; 4 - 24"; sleet/Freezing Rain E NS and interior Newfoundland Island)
Scattered Locations In
W ON....C, S MB....C, S SK....AB....MT....E ID....N, W WY
(Snow; Near-Blizzard; 4 - 10")
Isolated Locations In
W WA, W OR
(Snow; above 4000 Feet; 4 - 8")
Isolated Locations In
W NY....W PA....N WV
(Snow; In Squalls; 4 - 8")
GLOBAL WEATHER SUMMARY
(a review of important weather features around the world)
IODC
Dundee University
There is a very active southern branch storm track taking shape from Iran into the Himalayan Range, with an eventual destination over Mongolia and China. After a very cold winter (so far), the tendency for warmer air and heavy precipitation will be increasing in the PRC, particularly as the Madden-Julian Oscillation shows signs of being a contributor to moisture advection. So the threat for a prominent flood event in the Yellow River watershed is growing. Cold air seems to be retreating into the northern third of Siberia.
MTSAT
JMA
Here again we see the two big influences for weather around the Northern Hemisphere. One is the expanding (but retrogressive) Madden-Julian Oscillation, which again failed to follow model forecasts calling for a shift into "Phase 8" east of the International Dateline. Extreme amounts of heavy rainfall are again likely across Indonesia and Malaysia. In higher latitudes, an active storm sequence continues in progressive fashion through the northern Pacific Ocean. These disturbances, especially the huge gyre near the Aleutian Islands, will figure prominently in conditions across the lower 48 states over the next two weeks.
GOES WEST
NASA
There are three storms located in the northern branch jet stream between Japan and British Columbia, as well as a broad area of moisture following the subtropical wind field between Johnston Island and Baja California. These are the systems which could produce a wide, varied, and heavy display of precipitation through the U.S. over the next two weeks. Note the lack of ridging in the Gulf of Alaska or the western edge of the continent, which typically means that colder profiles will not dominate east of the Rocky Mountains. However, along the West Coast and through California and the Desert Regions, temperatures will be cold with a variety of inclement weather expected.
GOES EAST
NASA
Despite the rather ominous appearance of the satellite view off of the East Coast, the jet stream axis and developing storm organizing there will result in only a regionally intense system affecting Maine, the Maritime Provinces, and Atlantic Canada. A menacing blizzard will target those locales on Sunday, with drainage of cold air into the U.S. likely ceasing early next week with the encroachment of another disturbance from the Intermountain Region.
I should also point out that deep tropical waves continue to pound the northern half of South America, with a heat ridge in play from Argentina into much of Chile. The convective clusters are quite intense, and may be construed as a sign favoring an early and impressive start to the 2013 tropical cyclone season.
METEOSAT
SMHI
I outlined three equatorial convective systems which are moving westward along the ITCZ, which remains very active and is now attaining new energy from Kenya, Tanzania and Mozambique. Heat ridges are present over the Sahara and Kalahari Deserts. Europe is experiencing some moderation, but a new and intense mid-latitude cyclone is moving into the British Isles with heavy rain and wind.
SHORT RANGE OUTLOOK
(Through The Next 72 Hours)
Arctic Intrusion Across Eastern Half Of U.S. Is Transient; Moderation Starts In Great Plains, Old South
NASA (2)
Plymouth State University Weather Server (2)
Very cold air has expanded across the eastern half of North America in a full-latitude trough complex. Lacking a strong enough blocking signature in Canada (as of now only a weak signal in Baffin Island and Greenland), the trough should begin to lift out to the northeast on Sunday into Monday. In the process, the cold dome and 500MB vorticity core will curl into a very intense blizzard affecting Downeast Maine, the Maritime Provinces and Newfoundland/Labrador.
The system kicking out the cold air supply over the eastern states will be of modest strength, setting off a marginal severe weather threat from the "Arklatex" vicinity into the Tennessee Valley on President's Day and Tuesday with some snow and ice concerns over the northern High Plains and Upper Midwest into the Prairie Provinces. Colder air behind that feature looks to be quite limited with little impact below the Missouri River.
Very Cold Storm Threatens The West With Severe Weather, Heavy Mountain Snows
NASA
ECMWF
NOAA/NCEP
While the low pressure and frontal structure targeting the middle of the nation in early week is expected to be of relatively minor importance, the new storm sequence over the northern Pacific Ocean will have high impacts on at least the western two-thirds of the U.S. by the middle of the new week. Tapping abroad supply of equatorial moisture and energy from the subtropical jet stream, this feature will likely result in strong thunderstorms over parts of CA and OR, then advance with much colder air into the rest of the Golden State and Great Basin by Tuesday night. This is the feature which may trigger extensive severe weather and heavy rain over the lower Great Plains and Old South on Wednesday night into Friday, with snow and wind issues from the Intermountain Region into the Upper Midwest.
Continued In Part 2....
Comments