Inconsistencies in the Models

Monday, January 9, 2011
11:06 A.M.

As I sit in the Ocean Sciences building waiting for my “Climatic Extremes” class, I can’t help but wish for more exciting weather around here. Thankfully, some of the models are giving me some hope that we could see change, but other models give us weather that is even more boring than it has been over the past two weeks (if that is possible).

Here is what the National Weather Service forecasting office in Seattle had to say about the extended forecast this morning.

LONG TERM…PREVIOUS DISCUSSION…EXTENDED MODELS IN GOOD AGREEMENT 
THROUGH FRIDAY WITH AN UPPER LEVEL RIDGE OVER WESTERN WASHINGTON AND 
LOW LEVEL OFFSHORE FLOW. MODELS ARE A LITTLE STRONGER WITH THE LOW 
LEVEL OFFSHORE FLOW WHICH LESSENS THE THREAT OF STAGNATION. MODELS 
BECOME VERY INCONSISTENT OVER THE WEEKEND WITH THE GFS KEEPING THE 
RIDGE IN PLACE WHILE THE ECMWF BRINGS A COLD TROUGH INTO THE AREA. 
BY 00Z MON THE GFS HAS 500 MB HEIGHTS OF 567 DM OVER SEATTLE WHILE 
THE ECMWF HAS A 534 DM HEIGHT OVER SEATTLE WITH PLENTY OF 
PRECIPITATION. MODEL ENSEMBLES ARE NOT MUCH HELP OVER THE WEEKEND 
WITH WIDE SPREADS IN THE SOLUTIONS. IN GENERAL THE ECMWF HAS BEEN 
VERIFYING BETTER AND THE FORECAST IS TRENDED IN THAT 
DIRECTION…JUST NOT AS COLD AS THE CURRENT MODEL RUN WOULD SUGGEST. 
CONFIDENCE IN THE FORECAST OVER THE WEEKEND REMAINS LOW. FELTON 

Here, Mr. Felton is saying that the models are all over the place in terms temperature and precipitation in the extended. The GFS model (from the NWS) builds a ridge over us for the weekend (boring) while the ECMWF (European) model gives us colder air with rain in the lowlands but low snow levels in the mountains.

Since the European model is verifying better and is painting a more exciting picture for the extended, I’ll show you some pictures of the current model run.

Valid 04:00 am PST Mon, 9 Jan 2012 – ECMWF 500mb heights, SLP
Right now, we have a front to our north, bringing up warm air from the south and giving us some clouds. We will get rainier later today, but after that, we’ll be pretty dry again.
A bigger ridge builds up by Wednesday, with the jet stream going all the way up into Alaska.
Valid 04:00 am PST Wed, 11 Jan 2012 – ECMWF 500mb heights, SLP

4 minutes till class…

Take a look at the 168 hour frame! A huge ridge over the Eastern Pacific, but a huge trough over the Pacific Northwest. This is a classic setup for arctic air to invade our region.


Valid 04:00 am PST Mon, 18 Jan 2012 – ECMWF 500mb heights, SLP

Of course, the GFS completely disagrees. But at least there’s hope. 🙂
Charlie
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