"But seeing they could not See; hearing they could not Hear"
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"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".

Tuesday, August 30, 2011

Seat of The Pants Forecasts and Weather Anomalies Rule 2011. Is More on the Way?

No Doubt, Another Fly By The Seat Of Your Pants Forecast Day. All in all
the synoptic scale pattern has not changed much from yesterday. There is more moisture available and it is deeper further north toward I-10 on the east Side.  Again, high clouds from storms over the Gulf as seen in the radar overlay above are spreading anvils (high clouds) across all of the South half of the state. South Florida seems to be really socked in with some other sorts of clouds on visible satellite imagery as well...yet even term models reflect good thunderstorm and rain shower coverage in this area later today
(Refer to "What's Up?" further down to jump to the subject topic of today's post).

WHO MESSED WITH SUMMER? : Another picture book day to describe what is a non-typical summer day (one of many already and more to come through mid-September for the most part). We have definitely entered a period both pre- and post-Irene of mid-level troughs and tropical systems, surface boundaries and periods of the jet stream near by. In a sense, this is still the wet season but it is not the typical....:

 "high pressure Atlantic ridge axis across Florida with sunny mornings and light winds aloft followed by sea breeze convergence somewhere over the interior late in the day synoptic scale set up we normally have this time of year." 

 It appears that all ended when the pattern that evoked Irene to takes its run up I-95 (nearly) was the end of it.

 WHAT'S UP? It's as if summer packed its bags and went on vacation to Canada in tow (in some places like Florida even though it is still warm here)...leaving behind only the necessary items to keep the house in working order. That being, to keep the rain chances in check (but created by different mechanisms other that sea breeze convergence) such as troughs at different levels (that belong much further north ) and tropical like activity. The Old Salt of the Sea has come in to tend to matters while summer is sabbatical,  and he's messing around with the neat and tidy order that was once in place.  Actually, for this time of year it is not all that unusual, but I'd expect to find it more like in about two weeks from now. Will summer return ever for 2011? Yes, but modified. 

One of those self-improvement camps I guess was in order, since very little of this summer has ever been typical. This was long ago noted to be possible with the high pressure over Texas. This all began a LONG time ago, before the implications could be seen, felt, or experienced.  What was the first sign? The blizzard by Chicago, the Super Outbreak Part II Tornado Onslaught in the Deep South, or the one in North Carolina?  The heat wave in Texas that morphed, spread, shrankn and shifted around the southern tier of states? The lack of tornadoes west of I-35 in tornado alley this year? The supercell thunderstorms and tornadoes in North Central California while tornado alley was in a tornado drought? The deep snow in the Sierras in July?..Must have left a lot out. 

 Point is...expect more odd ball, out there anomalies are yet to come beyond the latest, the Irene event in Vermont (albeit created by rain..but it was odd ball nonetheless). 

TODAY: Same factors to leave things up for grabs in regard to rain chances. Best chance is where the least cloud cover exists, which is near and north of I-4. This is shown below. But other areas could see rains as well. In short, the normal summer rules do not apply today. Looking for the same factors as yesterday, but with slower steering and perhaps a sea-like breeze along the coast. There is a mid-level trough in place across I-10 or just south of there, and this will sink to South Florida going into Friday, but never completely washes out ..if not retrogrades a bit going into next week. It might even disappear off the charts for a while, but it will be back. 

Watching the areas closest to the mid level trough in black. SE Florida could still have many showers and storms with an east coast sea breeze, especially if the clouds can break up a bit...these are not drawn in...

TOMORROW/WEDNESDAY: The mid-level trough axis will sink a bit further south, so another day or two of tricks in the forecast are in store as it looks now. But, rain chances will be decreasing from North to South with time to some degree as more of an easterly flow moves in behind that boundary.  For a short time. 

Note: this boundary is also working into the SW Gulf where storm development is expected there as well. Whether it will be considered 'fully tropical' is yet to be determined..but the signal is clear. A low pressure area is in the making from the western Caribbean into the SW Gulf and north around the Texas to Louisiana Coastal areas.

By Saturday, the 700mb trough pictured in the previous images is located just north of the Florida Straits. Rain chances continue at their highest in this location and northward along the west side of the state for a day or two. Note the huge low pressure circulation in the mid-levels in the Gulf. A surface low could form here eventually...and is likely. But, if history repeats itself as it often could take almost a week or more to do so.

What is shown above is the broad low pressure circulation in the Gulf. The GFS eventually closes off one or even two surface lows. So far, they do not look completely organized, but would not be surprised if a tropical depression or even a storm is decided to be located there by the end of the first week of September.  

GFS for September 5th. Note that huge storm to the right. That is the GFS forecast for Major Hurricane Katina. A lot at this point in time is contingent upon whether Katina will even take this track in the first place. Per the GFS, the low in the Gulf gets caught up in the same trough shown in red along the eastern sea board..and piggy backs behind Katina...across Florida.

TROPICS: Tropical Storm Katina was realized early this morning. Model guidance is in close agreement through days 3-5. The storm is taking the path of least resistance where sheer is the weakest. The warmest waters are south of the storm now, but it will be entering warmer waters in about 3 days.  At this point, the best thing to watch will be its track during this time frame. ..especially near the end of the period. it approaches the Lesser Antilles. At time, it is not expected to impact those islands..but to begin a stair step curve to north of Puerto Rico with time. This is not set in stone...The image above shows where the storm will eventually end up on the 5th of September. Looks big...don't want to be messing with that keep your fingers crossed.  But......

Satellite and SAL (Saharan Air Layer) composite...the drier air around  the storm is to decrease around day 3 or 4 as the storm enters warmer waters which are now just south of the forecast tracks shown.
...BUT...look what the GFS brings into the picture further on down the line...for one week later.

This system is forecast to move west and under the high pressure that would build in behind the passage of this point in time..both the future track and especially this depiction are purely fictional...but it shows what can get the weather office's dander up in arms while the rest of the world is kicking back in the easy chair on weekday nights downing brews and eating Bon Bons.

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