TODAY'S FUN LINKS:
Lake-Effect Snow Sometimes Needs Mountains
Cyclone Haruna makes landfall in Madagascar
Flooding Tests Jakarta Governor Joko Widodo - NYTimes.com
WEATHER HAZARDS (During The Next 24 Hours)
SEVERE WEATHER OUTLOOK
(potential for tornadoes, damaging winds, and large hail within the next 24 hours)
Some Thunderstorms May APPROACH Severe Limits
Coastal TX, LA, MS, AL, N FL
STRONG WINDS
(Pressure Gradient Derived, Orographically Enhanced)
BC
HEAVY RAINFALL OUTLOOK
(potential for an inch or more total rainfall within the next 24 hours)
Scattered Locations In
Coastal BC, WA Olympic Peninsula
(QPF 1 - 2")
Isolated Locations In
Coastal TX, LA, MS, AL, N FL
(QPF 1 - 2")
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)
Isolated Locations In
SE MT....E WY....SW SD....NE Panhandle....CO....W, C NM....NE AZ....E UT
(Snow; 4 - 12")
Isolated Locations In
SE ON....N, C NY....N CT....RI....MA....VT....NH....ME....S QC
(Snow; 4 - 8")
Isolated Locations In
BC
(Snow; 4 - 12")
GLOBAL WEATHER SUMMARY
(a review of important weather features around the world)
IODC
Dundee University
While Cyclone Haruna is weakening and moving away from Madagascar, there is still an axis of disturbed weather stretching from the Congo Basin into the southern Indian Ocean which may support additional warm-core cyclogenesis. Thus not only is the Malagasy Republic at risk for continued flooding rains and thunderstorms, so will be Tanzania, Kenya and Mozambique.
There is a gap developing between a now-active Madden-Julian Oscillation and a cold domain covering most of Russia, Mongolia, and the Central Asian Republics. A tendency for warm and increasingly dry conditions should be noted from the Middle East through India, Bangladesh and Burma.
MTSAT
Digital Typhoon
Convection associated with the Madden-Julian Oscillation is expansive and quite intense, hammering Malaysia, Indonesia and northern Australia while showing a trend for retrogression toward the Indian Ocean theater. An immense and very cold storm complex between Japan and the Aleutian Islands has only a very weak connection to the equatorial thunderstorm groups, hence the likelihood that amplification of the jet stream over North America should be relatively short-lived. Moisture from the tropical forcing may, however, bring heavy rainfall to the eastern third of China over the next few days.
GOES WEST
NASA
Note the evenly spaced array of strong polar jet stream shortwaves across the northern Pacific Ocean into the western U.S. The question shaping up for the medium range forecast is simple: will the huge blob of moisture and energy below Hawaii interact with, and thereby fuel intensification, of the impulse now edging south of the Aleutian Islands. If so, risks for major snowfall and cold advection will dramatically increase across the Midwest into the Eastern Seaboard after February 28. As it stands now, the lead disturbance across the Intermountain Region is slated to bring a blizzard to the heartland of the U.S. in early week.
GOES EAST
NASA
We are once again seeing a continued barrage of equatorial waves across the northern half of South America. Most of the impulses are missing the shearing wind profiles about 5 degrees north of the Equator. The heat ridge which has created heat and drought concerns for parts of Argentina and Chile appears to be weakening.
The subtropical jet stream is very well-defined across the southern U.S., and may act as a catalyst for further strengthening of a storm entering the Eastern Seaboard later in the week. Note the powerful gyre in the northern Atlantic Ocean, which appears to be building a Rex block to its north over southern Greenland.
METEOSAT
SMHI
The split flow across Europe has given rise to record rainfall in Greece, and much of the Mediterranean countries will be at risk for severe thunderstorms and flooding rains during the next 72 hours as an upper low slowly moves from southern France into the Danube Valley. The colder northern branch disturbances have given snow to parts of the United Kingdom, Germany and Scandinavia, while Russia remains in a fairly cold but somewhat drier regime.
You can see on this METEOSAT image the ongoing thunderstorm channel between the heat ridges covering the Sahara and Kalahari Deserts.
SHORT RANGE OUTLOOK
(Through The Next 72 Hours)
Broad, Cold Trough Across Western Two-Thirds Of U.S. Yields Another Great Plains/Midwest Storm....
NASA
Plymouth State University Weather Server (4)
University Of Wisconsin Weather Server (3)
NOAA/NCEP
All eyes are on the storm complex entering the West Coast. Over the next four days, this feature will dig into the lower/middle Great Plains while introducing very cold air from Canada and deep tropical moisture from the Gulf of Mexico. There are going to be two prominent consequences of this system as it takes a fairly classic Panhandle Hooker "B" path (Amarillo TX....Fort Smith AR....Louisville KY....Cleveland OH with redevelopment over North Carolina on Tuesday). One will be astonishing amounts of heavy snowfall from N OK....KS....N, W MO....SE NE....IA....SW WI....NW IL (yes, more chances for heavy thundersnow in Kansas City MO metro!). Another threat will be heavy rainfall and severe thunderstorms from the Gulf Coast into the Southeast, as the warm front runs into an entrenched cold layer covering parts of the Old South and Eastern Seaboard.
One critical point I must emphasize is what happens to another shortwave following the main storm center. This feature progresses form the Pacific Northwest into the Texas/Oklahoma Panhandle Region by early Wednesday. There are suggestions by some of the model ensemble members that this impulse and its cold air pool will maintain its integrity into the Dixie states on Thursday, thereby creating the risk of a lower-latitude snow episode (say Ozark Plateau into Tennessee Valley and lower/middle Appalachia). It remains a slight possibility that a new case of frontal wave cyclogenesis could occur in association with this disturbance over North Carolina in late week. More on that topic in the Medium Range Outlook.
....While Eastern States (For The Most Part) Temporarily Stay Out Of The Cold
NASA
ECMWF
Because the Rex signature taking shape over eastern Canada into Greenland is slow to build (evidence the 72 hour ECMWF 500MB forecast), the eastern third of the nation will largely dodge the intrusion of Arctic air across the middle half of the continent. The small disturbance giving chances for moderate snowfall in New England will give way to southwest flow aloft ahead of the big snowmaker in the Great Plains and Mississippi Valley. So when the larger cyclone approaches the East Coast, much of the precipitation that falls will be in the form of rain. Enough vertical lift with infusion of tropical air will be present so that thunderstorms could occur in the Mid-Atlantic and New England states early Wednesday. Some danger also exists for freeing rain and sleet in WV....W VA into W, C PA and W, C NY from warm air overrunning trapped cold layers.
Comments