FLSC Message Board: First August Weekend

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First August Weekend

Posted by Ray on 7/31/2009, 1:45 pm
69.205.81.50

Bottom lines:
Saturday: decent soaring day.
Sunday: not.

Details: Shouldn't midsummer be defined as halfway between the first day of summer and the first day of fall (about Aug 6th)? Because of the enormous thermal mass of the planet, that's about when growing things max out, not the longest day of the year. The vegetation is lush now, corn is tall, and the only field crop harvested around here is wheat. And July has had nearly twice the average rainfall. Trees and green plants evaporate lots of water in sunlight. The water table is high, the soil is damp. Much as we don't like it, that does not make for great soaring. Surely, Saturday will be better than yesterday, when my pessimistic forecast unfortunately came to pass. But not markedly better. It will be a bit drier than Thursday, cloud base a bit higher, and thermals a bit stronger. But tomorrow's high is again weak, and there is no strong cold advection to bring in a favorable lapse rate. That means the sun alone will have to do all the work, and work against the dampness and vegetation. So the morning will be good for instruction and developing winch proficiency. And the afternoon....will be good for practicing cloud reading.

Sunday: I'm weary of bringing bad news; instead I've pasted the Buffalo discussion, and you can be mad at those guys:

DURING SUNDAY...THE AFOREMENTIONED FRONTAL BOUNDARY IS FORECAST TO CROSS THE AREA...WITH SOME SCATTERED SHOWERS AND THUNDERSTORMS PRECEDING AND ACCOMPANYING ITS PASSAGE. THE SHORT TERM OPERATIONAL GUIDANCE CONTINUES TO EXHIBIT SOME MODEST DIFFERENCES WITH THE TIMING OF THE BOUNDARY...WITH THE NEW 00Z GFS THE FASTEST AND INDICATING A FROPA BY MIDDAY/EARLY AFTERNOON...THE 00Z NAM ABOUT 6 HOURS SLOWER OWING TO ITS DEVELOPMENT OF A WEAK WAVE ALONG THE FRONT...AND YESTERDAY'S 12Z ECMWF LYING ROUGHLY IN BETWEEN. THE TIMING OF THIS FEATURE WILL BE IMPORTANT WITH RESPECT TO THE POTENTIAL FOR ANY STRONGER/SEVERE STORMS...WITH ANY SUCH CONVECTION BECOMING SOMEWHAT MORE OF A POSSIBILITY ACROSS OUR EASTERN ZONES IF THE SLOWER NAM SOLUTION VERIFIES. FOR NOW...WILL INDICATE BROADBRUSH MID RANGE CHANCE POPS FOR THIS PERIOD...WITH THE ACTIVITY QUICKLY WINDING DOWN BY EARLY-MID SUNDAY EVENING AS SUBSIDENCE AND MUCH DRIER AIR WORKS IN BEHIND THE DEPARTING FRONT.

(note: FROPA = frontal passage)

Ray