The active weather pattern continues across the U.S. & is gradually shifting more south & east with time which will translate into a more active -- & potentially -- wetter pattern for the First Coast. We're likely to continue to see wide temp. fluctations over short periods of time (80 last Wed.....52 Sun......24 Mon. morning....79 Tue....65 Wed...75-80 Fri. & Sat.
A front will hang near the First Coast Fri. through the weekend into early next week & will be the focus for rain & a wide range in temps. from north of the front vs. south of the front. So the key to the forecast on any given day will be where the front is located. Wed. & Thu. of this week will be dry, but the first round of rain moves in Fri. & primarily over Southeast Ga. where rain could be heavy. The front should slide far enough south to increase rain for Jax & Northeast Fl. later Sat./Sat. night, so "Monster Jam" Sat. night could be wet. The front should drop a little south Sun. which could give Ga. a break from the rain but may not be good news for the Daytona 500. The front then moves back north early next week pushing rain back across NE Fl. & SE Ga. Depending on the exact location of the front & upper level weather disturbances, there will likely be some areas that receive heavy rain.
Apparently CNN & TWC have been raising a ruckus about the superiority of the European forecast model vs. the American GFS model.
It is true that the GFS struggled mightily the first 3/4 or more of this century. The European wasn't so hot in the 1990s as it consistently over-developed winter storms. Truth be told there's no such thing as the perfect model. They are -- afterall -- just models(!). The better forecasters are generally those that use a combination of:
-- logic
-- understanding model bias
-- not getting overly excited during a given weather situation/event
-- looking outside(!)
-- sometimes throwing away the textbook
I was extremely critical of the GFS particularly from the late ‘90s through about 2010. During the tropical season, tropical cyclones were forecast to recurve or move east way too early due to a bias of lowering pressures too fast (or weakening high pressure) to the north & east of the cyclones.
Tweaks are frequently made to many of the forecast models. Often times – whether or not numerical forecasters will admit it – these tweaks cause more harm than good when it comes to model output. In fact, it’s my belief that the model tweaks are done too frequently & without cause -- not enough positive changes for the headaches that are produced. Good forecasters will learn the bias of models & then be able to become better forecasters. The tweaks make these bias’s more difficult to pinpoint. The FSU Super Ensemble tropical model would be more reliable – as is readily admitted by FSU researchers – if there was less model meddling.
Anyway….the GFS had many difficult years & was generally inferior to several models, the European included. That’s not to say the European was perfect – far from it. The model way overdid winter storms in the ‘90s. BUT the GFS is coming off a far better year in 2012, & the improvement began in 2011 after a number of tweaks. Finally – the “modelers” made changes that improved the GFS forecasts. A finer resolution & better input probably led the charge. Not to be outdone, tweaks were also performed on the European, & I personally don’t think it’s as good as it was several years ago –as a whole. Before simply bashing the GFS & championing the European model, I’d like to sight a few recent examples that come to mind:
** Tropical Storm “Debby” in June. The European consistently developed “Debby” into a powerful tropical cyclone that moved west/northwest through the far Northern Gulf eventually hammering New Orleans & points west. The GFS consistently developed a shallow, weaker “Debby” that moved east into Florida. Score 1 for the GFS!
** Hurricane “Isaac” – both models had their problems with this storm. The GFS was too far east but the European was too far west. Both models over intensified the storm . At landfall, the European corrected too far east, the GFS a little too far west. In the end, the GFS was no worse & maybe better than the European. Though you might have heard chatter about how great the European was, that opinion would have to be based on the model’s better depiction of the early stages/path of the cyclone (more west).
** Hurricane “Sandy” – the European struggled mightily with the genesis of this storm in the Caribbean & never really picked it up ‘til the storm had become fully developed & was strengthening (for some reason this is being overlooked). The GFS was excellent with formation & initial movement. It’s very worth noting that the GFS has had back-to-back excellent years – in general – on tropical cyclone genesis while the European has struggled in that department. Now many will argue that the European did a better job on “Sandy” once it moved farther north then bent west. That’s true, but the GFS was not completely out to lunch on that – especially 3-4 days or so in advance. The GFS did struggle in the 4-6 day forecast for a couple days on whether or not “Sandy” would recurve north/northeast or turn west. It's worth noting -- as is commonly the case -- that a consensus of forecast models ends up being the best track forecast which is what the Nat. Hurricane Center often uses. The forecast of "Sandy" -- in the end -- was excellent & gave the public & private sector as well as emergency management officials plenty of time to prepare. The so-called spaghetti plots of forecast models for "Sandy". Take the average, & one comes up with a pretty decent forecast.
** the winter storm (mid latitude cyclone) in late Jan. that spawned the intense EF-3 tornado NW of ATL (Adairsville) was much better forecast – especially in the 3-6 day time frame – by the GFS. The GFS insisted on a longitudinal trough phasing over the Central & Eastern U.S. to produce a strong low pressure system that would produce heavy rain & severe storms in its warm sector & a blizzard to its northwest. The European insisted on a split with a major piece of energy hanging back & cutting off over the SW U.S. This scenario never happened – big score for the GFS.
So…..while the GFS is not perfect -- & no model is! -- it seems to be far better than previous years. New tweaks could, of course, turn the tide. But I do believe the gap has been seriously closed between the 2 models compared to years past. One problem I am seeing now with the GFS is way too many intense mid latitude cyclones in the 8-14 day range but – hey – that’s way out there in the realm of long range forecasting & its usefulness.
