"But seeing they could not See; hearing they could not Hear"
“The views expressed herein are those of the author and do not necessarily represent those of the National Weather Service or affiliate/related organizations. Please consult .gov sites for official information”

"From its chamber comes the whirlwind, and cold from the scattering winds." - Job 37:9.

"The wind blows to the south and turns to the north; round and round it goes, ever returning on its course".

Friday, November 25, 2011

Black Friday Forecast Frills - Bleak or Best Buy?

For image's sake, this is what the clouds over the state look like from above this afternoon, compliments of satellites above which relay the information down to planet bound denizens  

TODAY Through SATURDAY: High pressure just to the north of the state is slowly sliding east with Florida in the return easterlies behind its clockwise circulation. Moisture is just deep enough to generate the clouds as seen here and if you look outside, there as well (in most cases). Otherwise, winds from the East to ESE at 10-20mph with some higher gusts and highs in the mid-upper70Fs are the prevailing modus operandi through Saturday, although it could be  a few degrees warmer (especially than those of today) toward the Panhandle.  Shower chances are not zero, but even if they can manifest, they will be so light as to be considered 'no impact sensible'. 

SUNDAY-TUESDAY:  Sunday's winds become  SE-SSE (if not South), with temperatures running into the upper 70Fs - lower 80Fs (most likely). From there begins the dilemma. So, rather than provide a detailed  and quite laborious task of synoptic scale differences between each model at various atmospheric levels, we can look at why this is the case at hand in the first place. This can be best performed by observing a few discrepancies between the weather models used to forecast temperature, rain, and wind based on the mathematical equations employed by each without going into detail.

ASSUMPTION (S): It appears that there could be some interseasonal variations being detected or in process but which have not yet come to fruition. Most readers will have heard of La Nina which seems to be running right about normal (in many years it is not present, or the counterpart Le Nino is in force).  That is a factor to consider. Then consider this possibility: the Madden-Julian Oscillation, affectionally referred to as MJO (as opposed to having a MOJO). Yet still, perhaps the North Atlantic Oscillaion (NAO) might also be scheming an attack to ruffle  the forecast's feathers. Point is, given the time of year , climactic winter on the very near approach and variations within this time a near given initially, combined with those additive factors,  each model by all appearances seems to be weighing one of more of those variants into their equations..but providing astoundingly dissimilar results.  Examples:

The Global Forecast System (GFS) Model: Front to cross the state overnight Sunday night, accompanied by rain showers for at least the north half of the state, followed by a significant cold down. Lows in the upper 30Fs (north) through the mid-40Fs south by Monday/Tuesday time frame, with highs never breaching 60F most areas. The GFS of this morning shows these very cool to near cold (as well as very dry) Floridian conditions to prevail through early Wednesday . Well below normal. The next front arrives after perhaps 18-24 hours of slight warming before yet another re-enforcing front comes through dry...and more cold air of similar consequence...a long cold week by standards of the past 8 months.

The European ECMWF model on the other hand from last night does not have the front going through until sometime toward late Tuesday or early Wednesday. Additionally, it forms a surface low in the eastern Gulf of Mexico just off Cedar Key...with much more time for southerly flow to prevail prior to frontal passage. That would allow for not only deeper moisture to be in place prior to passage, but also create a set up much more favorable for thunderstorms as well (perhaps severe). Frontal passage was generally indicated sometime Wednesday at the latest per this model's bidding.

The NoGAPS and Canadian Models fall somewhere in between the two, with the CMC (Canadian) coming closer to shaking hands in agreement with the Europeans. Then again, the Navy NOGAPS model sides with the GFS,  not exactly...close, but slower.

Eventually, something resembling a model treaty will evolve , likely (or hopefully) by Saturday evening. By the time we reach Sunday should be completing signature, but we will have the opportunities to see in each and every subsequent model run of each player just exactly what the TREND is.

If only it was as easy as going to Best Buy to know right now.  The common remark made by National Weather Forecast offices in these cases sums it up neatly and simply,  "Stay Tuned" (the old fall back, "A word of the wises, be prepared for surprises" could aptly work as a second opinion of opinions.) Or as Confucius Say, "Forecast Model Not For Sale, Look at Sky and Figure out yourself".

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