Why we can't fly today

I was emailing a primary student of mine who has about 35 hours total time that he logged 15 years ago. 

We were scheduled to fly at 1pm today. Looking out the window it appears to be a wodnderful day to fly 

but theres more to it.  


 
 
The way those forecasts read is the are valid from the time shown until the next time shown. 
So they are calling for the winds to be gusty until 6. But what’s magical about 6? The sun goes down. 
 
All weather is the result of a heat exchange. Right now it’s calm but as the sun starts heating 
things up on the ground the air starts to move around. Things on the surface heat at 
different intervals which creates columns of rising and falling air.
There is a reason we have such clear skies today and it’s called instability. 
A characteristic of unstable air is clear skies and good visibility. 
 
Here are the current winds aloft.
 
FT  3000    6000    9000   12000   18000   24000  30000  34000  39000
JFK 3431 3224+01 3129-03 3133-09 3137-22 3144-33 304349 294258 304563
          New York NY [JFK]
BDL 3334 3230+01 3132-04 3037-10 3144-22 3147-34 305348 294256 303963
          Windsor Locks CT [BDL]
 
At 3000’ it’s 340 at 31 at JFK and at Bradley its 330 at 34. 
So if you take a look at the surface winds
 
KJFK 071251Z 31008G15KT 10SM FEW250 06/M09 A3010 RMK AO2 SLP192 T00561089 $
KBDL 071251Z 31009KT 10SM FEW150 03/M06 A3003 RMK AO2 SLP169 T00331056
KDXR 071253Z 00000KT 10SM CLR M01/M06 A3007 RMK AO2 SLP187 T10111056
 
You see that there is a marked difference between the winds on the surface and aloft at 3000.  
At JFK the wind is 310@8 with gusts to 15. So if you were to climb off JFK the wind is going to 
change direction 30 degrees and the  intensity  will increase from 8 to 31 kts. 
 
Where that happens it is known as wind shear and that produces turbulence.
 
Bradley is the same. The wind on the ground is 310 @ 9 and the winds aloft 330 @ 34. 40 degrees 
and 20kts from the surface to 3000. 
 
Boston AIRMET, prepared on the 7th at 3:45am EST (0845Z).
  AIRMET Tango update 1 for turbulence valid until the 7th at 10:00am EST
    (1500Z).
    No significant turbulence expect outside of convective activity. 
    Outlook valid 1500 - 2100Z ... turbulence New Hampshire Vermont
      Massachusetts Rhode Island Connecticut New York low New Jersey
      Pennsylvania and coastal waters bounded by 40 miles south-southwest of
      Ottawa CA [YOW] - 20 miles west-northwest of Boston MA [BOS] - 20 miles
      east of Coyle [CYN VOR] - Buffalo NY [BUF] - 40 miles south-southwest
      of Ottawa CA [YOW] moderate turbulence below 6,000 feet. Conditions
      developing 10am EST (15Z) to 1pm EST (18Z). Conditions continuing thru
      4pm EST (21Z). 
 
It spawns an Airmet which is a meteorological event for light aircraft similar to ‘small craft advisory’ for boats. 
Now if you never fly when there is an airmet you’ll never fly. But there is one today. 
However if we were travelling somewhere I’d say climb above 6000 where it will be smooth. 
 
How do we know that? Look at the 6000’ winds which calm down/lose intensity at 6000.
 
A lot to read in a forecast. 
 

Bridgeport CT (Igor I Sikorsky Memorial) [KBDR] terminal forecastissued on the 7th at 6:45am EST (1145Z), valid from the 7th at 7am EST (12Z) through the 8th at 7am EST (12Z)


7am EST (12Z)

wind 300° at 7 knots, visibility greater than 6 miles, sky clear


9:00am EST (1400Z)

wind 310° at 11 knots gusting to 18 knots, visibility greater than 6 miles, sky clear


6:00pm EST (2300Z)

wind 290° at 6 knots, visibility greater than 6 miles, 25,000 feet few. 

White Plains NY (Westchester County) [KHPN] terminal forecast
issued on the 7th at 6:39am EST (1139Z), valid from the 7th at 7am EST (12Z) through the 8th at 7am EST (12Z)


7am EST (12Z)

wind 310° at 6 knots, visibility greater than 6 miles, sky clear


9:00am EST (1400Z)

wind 310° at 12 knots gusting to 20 knots, visibility greater than 6 miles, sky clear


6:00pm EST (2300Z)

wind 300° at 10 knots, visibility greater than 6 miles, 25,000 feet few


10:00pm EST (0300Z)

wind 310° at 5 knots, visibility greater than 6 miles, 25,000 feet few AMD NOT SKED. 

Oshkosh 2009 - The Trip Home

We spent or last afternoon/night in the north 40 eating boudan with Jerry from Dallas and then celebrating Pete's birthday at his and Beth's 172. I obtained a 9am STMP slot for an IFR departure and had the Basler guys fill the Mooney with Avgas.

We went to bed around 10pm and prior to doing so obtained a duats briefing on the laptop which said that OSH would be vfr until mid morning and then would gradually go IFR due to an approaching low pressure system with a warm front associated with it. Everything looked good across the route of flight so we went to bed expecting to get up at sunrise strike camp, say our good byes, and fly away from the bad weather through nice and towards unsettled.

We'd then have to deal with the remnants of another frontal system which should have been moving off the Maine coast while we were sleeping.

Still another low pressure system with an east west stationary front was impacting the lower mid atlantic back through Pennsylvania Southern Ohio into Kentucky with a cold front extending  south westerly through the blue ridge and smoky mountains.

Anyway we go to sleep and wake at 4am CDT to the sound of light rain hitting the tent and airplanes outside. Judy heard it too so we sort of waited while waking up about 10 minutes till she said 'You know it'll suck to put this stuff away in the rain'. Clearly the forecasts were wrong and the system to the northwest of Oshkosh had moved quicker than anticipated. We got out of bed deflated the air mattress and put on the clothes we had left out for the trip.

Pete and Daryll helped me pull the plane out of the divots it had created sitting in the grass. We wished everyone well started the engine at 6:30AM and were taking off runway 27 at 6:45.  We followed the vfr departure procedure and our amended plan was to make for Rockford then land and get some coffee in us and formulate a plan.

Our departure was in 2000 overcast and 5 miles with  light rain falling. We followed the outbound procedure and then made our way towards RFD picking our way down there using the XM's   NexRad to keep us clear of the yellow and red returns between us and the airport.  We called Rockford approach from 20 miles out and set up for the right base entry to Runway 27.

The FBO staff were barely awake when we got there and seeing we were drinking their coffee and using their restrooms I had them top the Mooney. We filed for Cleveland Burke Lakefront and departed southeast bound towards Peotone to make the turn east. It’s interesting to note that the Chicago controllers are as intolerant as their New York associates and I wonder whether it’s like that all year or just during Oshkosh. We took 7000 and were blessed with a nice tailwind bringing the groundspeeds into the 175kt range.

After a while we started running into a broken to overcast layer at 7000 so we asked for 9000 and got even more of a push.

We were cleared direct Waterloo and then to the airport. I never like descending over water but they cleared us down to 2000 and then started vectoring us away from Hopkins bringing us lower and farther away from the shore. Finally I called the field in sight and was told to enter the right downwind and call the tower.  We landed and taxiied in to the delight of all the friends we had made at the FBO a week earlier.

We took on more gas, ate some sandwiches and filed for Danbury.  Pennsylvania was IFR low in places with convective activity across the state and points south. I planned to dxr taking a northeasterly routing to ERI DKK ULM ITH DYY and then the NOBBI3 arrival into DXR. We blasted off from Lakefront and at 5000 we were in the broken to overcast layer for the first hour of the trip. It cleared out around Ithica and we climbed to 9000 again to get on top. When we made the turn south east they descended us to 5000 where we stayed until about a mile past IGN. Boston center handed us off to New York Approach on 126.4. We called and were cleared down to 2500 and then cleared direct to DXR. 

We landed and unloaded the plane into the car then drove home. We flew about 7 hours on three legs and made it back home in time to fire up the grill and cook dinner. We used our airplane as transportation waking up in Wisconsin and in a day’s work landed in Danbury where after a 15 minute drive were at our house. It wasn’t the trip I had planned the day before but the desired outcome was achieved. That’s what you own an airplane for.