Post by thibodauxwx on Dec 11, 2013 13:02:35 GMT -6
here is Larry Cosgrove's write up from this morning:
Larry Cosgrove
Some words about the upcoming weekend storm threat and the overall weather pattern through the Christmas/New Year's holiday week....
1) Judging from the impressive satellite signature of the storm taking shape along the West Coast, the numerical models have been badly underestimating the intensity and precipitation outlay over the U.S. between Thursday and Sunday. The southern branch (number 2 on the GOES WEST image) is very reminiscent of energy/moisture arrays that phased with some of the more interesting events of the late 1970s and the chief analog year of 1981-82.
2) I see risks for heavy-to-severe thunderstorms from Texas through the Dixie states on Friday and Saturday.
3) The cold dome over Quebec and Ontario will hold on long enough for an extended change from snow to mix/ice and then rain above Richmond VA. Forcing secondary cyclogenesis off of the Delmarva Peninsula on Saturday evening, the advance of liquid types will likely come to a screeching halt over NW NJ....S NY (above NYC)....CT....RI and then slowly return southward. Accumulations will be minimal below the Mason-Dixon Line, marginal from S PA into NJ and NYC/LI NY (2-4", higher in spots), and heavy across the mountainous Northeast and most of New England, where up to 2 feet may fall.
4) Cold air drainage sets up lake-effect and lake-related snow plumes in most of the Great lakes region into the Tug Hill Plateau and middle Appalachia. Locally heavy squalls may occur in the "usual suspect" spots.
5) A nice warm-up may take place below 40 N Latitude between December 16 and 20, as the upper level wind fields take on a semizonal bent (although the Great Lakes and Northeast likely stay chilly or cold).
6) Yes, I believe the mega-bomb cold shot scenario between December 21 and 27 over much of the nation. The advertised surface temperatures are probably 10 degrees (F) too cold, but the idea of a huge cAk motherlode dropping down between the central Atlantic Ocean ridge and the vast -EPO ridge from Alaska into Hawaii has merit.
7) The threat for an important if not extreme winter storm is still on from December 21 (Texas/Oklahoma/Kansas) to Christmas Day (Maritime Provinces). If the ensemble member mean of the GFS and ECMWF runs have a handle on this feature, the holiday commute will be a fright-fest with abundant snow and ice related closings and delays.
It's the most wonderful time of the year!
Larry Cosgrove
Some words about the upcoming weekend storm threat and the overall weather pattern through the Christmas/New Year's holiday week....
1) Judging from the impressive satellite signature of the storm taking shape along the West Coast, the numerical models have been badly underestimating the intensity and precipitation outlay over the U.S. between Thursday and Sunday. The southern branch (number 2 on the GOES WEST image) is very reminiscent of energy/moisture arrays that phased with some of the more interesting events of the late 1970s and the chief analog year of 1981-82.
2) I see risks for heavy-to-severe thunderstorms from Texas through the Dixie states on Friday and Saturday.
3) The cold dome over Quebec and Ontario will hold on long enough for an extended change from snow to mix/ice and then rain above Richmond VA. Forcing secondary cyclogenesis off of the Delmarva Peninsula on Saturday evening, the advance of liquid types will likely come to a screeching halt over NW NJ....S NY (above NYC)....CT....RI and then slowly return southward. Accumulations will be minimal below the Mason-Dixon Line, marginal from S PA into NJ and NYC/LI NY (2-4", higher in spots), and heavy across the mountainous Northeast and most of New England, where up to 2 feet may fall.
4) Cold air drainage sets up lake-effect and lake-related snow plumes in most of the Great lakes region into the Tug Hill Plateau and middle Appalachia. Locally heavy squalls may occur in the "usual suspect" spots.
5) A nice warm-up may take place below 40 N Latitude between December 16 and 20, as the upper level wind fields take on a semizonal bent (although the Great Lakes and Northeast likely stay chilly or cold).
6) Yes, I believe the mega-bomb cold shot scenario between December 21 and 27 over much of the nation. The advertised surface temperatures are probably 10 degrees (F) too cold, but the idea of a huge cAk motherlode dropping down between the central Atlantic Ocean ridge and the vast -EPO ridge from Alaska into Hawaii has merit.
7) The threat for an important if not extreme winter storm is still on from December 21 (Texas/Oklahoma/Kansas) to Christmas Day (Maritime Provinces). If the ensemble member mean of the GFS and ECMWF runs have a handle on this feature, the holiday commute will be a fright-fest with abundant snow and ice related closings and delays.
It's the most wonderful time of the year!