Short Range Forecast Discussion
Valid 00Z Mon Nov 18 2013 - 00Z Wed Nov 20 2013
...Severe weather possible for the Mid-Atlantic and the Northeast ahead of the frontal boundary...
...Strong and gusty winds expected across the Great Lakes and Northeast on Monday...
...Organized precipitation moves onshore in the Pacific Northwest by
Widespread showers and thunderstorms will continue to breakout tonight and into the early morning hours of Monday ahead of the cold front currently pushing through the Mid-West.
The Storm Prediction Center has noted that a few of the storms overnight across the Mid-Atlantic and Northeast could be strong and/or severe, but a widespread severe weather outbreak is not
expected like we saw this afternoon across the Ohio Valley.
The cold front is expected to push off the Mid-Atlantic coastline by Monday morning and surface high pressure will move in bringing clear skies and pleasant weather back to most of the eastern half of the nation.
As the fairly deep surface low attached to the aforementioned front moves northeast into Canada overnight tonight, a strong pressure gradient will set up across the Great Lakes and the Northeast bringing strong and gusty winds to these areas on Monday.
Additionally, moisture being wrapped around the low combined with westerly winds behind the front could bring a few light to scattered lake effect rain/snow showers to parts of both the Upper and Lower lake regions.
Meanwhile, out west, persistent onshore flow off the Eastern Pacific will continue to fuel light and scattered rain and higher elevation snow over the Pacific Northwest and Northern Rockies.
By Monday morning, a system approaching the coast will stream more steady and heavy precipitation into coastal Washington and Oregon and should spread to the Northern Rockies by the afternoon hours. Some minor accumulation of snow in the higher terrain is possible later in the forecast period.
Extended Forecast Discussion
Valid 12z Wed Nov 20 2013 - 12z Sun Nov 24 2013
...Winter Pattern Overview And Guidance Preferences...
Guidance Has Converged Upon A More Common Overall Noam Pattern Evolution...But Horrendous Recent Run To Run Continuity Issues Suggests Some Prudence With Respect To Raising Forecast Confidence To More Than Average Levels Until Viewing Another Guidance Set Or So.
Latest Models And Ensembles Now More Similarly Highlight Not Only An Amplifying Wrn Can/Nwrn Us Ridge And Downstream East-Central Us Nrn Stream Trough Aloft...But Also A More Separate
And Less Progressive Srn Stream Flow Including Development And
Maintainance Of The Swrn Us/Nw Mexico Closed Low.
The 00/06 Utc Gfs And 00 Utc Canadian/Dgex/Ukmet Along With The Ecmwf/Ecmwf Ensembles Now Offer This More Separate And Threatening Srn Stream...With The 06 Utc Gfs Ensemble Mean Now Also Trending Significantly Toward This Solution Compared To The Prior 00 Utc Version.
Accordingly And Considering Wpc Continuity And Recent Model Issues/Lingering Uncertainty And Timing Differences...Todays Wpc Medium Range Product Suite Has Been Primarily Derived From A
70-30 Blend Of The 00 Utc Ecmwf Ensemble Mean And 06 Utc Gfs
...Sensible Weather Highlights...
The Focus For Rain And Higher Elevation Snow Over The West Should Trend Ssewd From The Central West Coast/N-Central Rockies Toward The Southwest/Srn Rockies As Srn Stream Mid Level Troughing And Expected Closed Low Develops.
The Favored Terrain Of The Southwest Should Experience The Highest Totals Over The Coming Week In A Prolonged Event.
Expect An Increase In Coverage/Intensity Of Precipitation Starting Over The Plains Late In The Week...With A Broad Area Of Moisture Continuing Ewd As A Leading Cold Front Heads Toward The East Coast.
Snows Are Possible From The Central High Plains Into The Great Lakes And The Northeast Interior While Rain Should Fall Elsewhere.
Highest Rainfall Totals Are Anticipated From The Srn Plains Into The Tn Valley.
The Central Then Ern Us Should See Two Main Surges Of Cold Air...The First Starting Early Week Followed By Another Fri Through Next Weekend.