Go or No Go: battling a Nor’easter?

As a corporate pilot, you watch your phone continuously – if it rings, you’re probably going flying. Today, you’re really hoping it doesn’t ring, because there’s a nasty weather system parked across the eastern US – right where you often fly. So of course Murphy’s Law is in effect and the boss calls – he needs to get from your home base in Cincinnati, Ohio (LUK) to Danville, Virginia (DAN). And he needs to get there today.

At least you have a capable airplane – the Cessna 340 you fly is pressurized, has two turbocharged engines, weather radar and deice boots. It also has a G600 glass panel, dual WAAS GPS navigators and a good autopilot. You’re a fairly experienced pilot, with 2500 hours total time and nearly 1000 hours in the 340, and you fly it single pilot IFR all over the country.

But is today too much? As you contemplate the 3pm takeoff (1900Z), here is the weather report.

Overview

A cold front came through earlier in the week, but it stalled out over the Atlantic coast, and an off-shore hurricane seems to be feeding it moisture. Rain is moving onshore, from east to west, in waves.

GNGD route overview

The surface analysis chart shows the details, including that Low that is just sitting there off South Carolina:

GNGD surf analysis

Forecast Charts

The question is, where is all that weather going? Unlike a typical pattern, it seems unlikely it will slide offshore. The 12-36 hour surface charts don’t show much change at all.

GNGD 12 hour surf

GNGD 24 hour surf

GNGD 36 hour surf

To get a three dimensional view, you look at the low level prog charts. These show, as you would expect, IFR conditions and low level turbulence over most of the mid-Atlantic.

GNGD 12 hour aloft

GNGD 24 hour aloft

The 500mb analysis adds a little more detail – suggesting there isn’t much of an upper level force to send that rain out to sea.

GNGD 500mb

Radar and Satellite

From forecasts it’s now time to move to observations. A look at the radar and satellite imagery offers this unappealing view, although your destination does seem to be west of the worst rain, and it doesn’t look convective.

GNGD radar

GNGD satellite

Ice, Turbulence and Convection

In-flight icing certainly could be a consideration on this early Fall day, and there is some activity in the flight levels today. First, the icing AIRMETs.

GNGD ice airmet

Then the icing forecast, which is awash with blue. At first glance, it looks awful.

GNGD ice overview

But when you dig deeper, the forecast products look pretty clear below 11,000 ft.GNGD ice 11K

Convection also doesn’t seem to be a big issue – that mess of precipitation is mostly rain. The convective SIGMETs map shows only activity offshore.

GNGD conv sigmet

A glance at the newer CCFP tool, which not necessarily predictive, does offer more detail about any potential thunderstorms. You look at the 2-hour and 4-hour products.

GNGD 2 hour CCFP

GNGD 4 hour CCFP

Turbulence, on the other hand, seems almost unavoidable today. Like the icing, though, the worst rides seem to be up high. If you stay down low, the forecast maps don’t show much more than occasional light chop.

GNGD turb 11K

GNGD turb 15K

Pilot Reports

With that big picture in mind, it’s time to turn to the PIREPs for a real-time look at conditions. Icing PIREPs are out there for sure, but all of them are at 18,000 ft. and above.

GNGD ice pirep

There are plenty of turbulence PIREPs, but again, almost all of them are in the flight levels. Is the ride OK or is nobody flying?

GNGD turb pirep

Skew-T Diagrams

Just because you’re a real weather geek, you review the Skew-T log(p) diagrams for a three dimensional look at the atmosphere near your departure and destination airports.

GNGD skewt LUK

GNGD skewt DAN

Text Weather

Finally, it’s on to the text weather reports. The METARs and TAFs for your departure airport show gusty winds, but pretty high ceilings and good visibility for now. That may not continue, though.

KLUK 021653Z 03016G20KT 10SM SCT120 14/08 A3010
KLUK 021553Z 04015KT 10SM SCT025 BKN090 OVC110 12/07 A3011

TAF KLUK 021743Z 0218/0318 04015G22KT P6SM VCSH OVC050
TEMPO 0218/0222 OVC035
FM030000 04016G20KT P6SM VCSH OVC050
TEMPO 0310/0312 3SM -RA OVC028
FM031300 04014G20KT 5SM -RA BR SCT009 OVC018
FM031600 05015G23KT 5SM -RA BR OVC009

The METARs and TAF at your destination aren’t quite so good.

KDAN 021736Z AUTO 04012KT 2 1/2SM -RA BR BKN011 OVC015 13/12 A2994
RMK AO2 P0003 T01330117= (SPECI)
KDAN 021653Z AUTO 03009G19KT 10SM -RA BKN010 OVC014 13/12 A2993 RMK
AO2 RAB12 SLP129 P0001 T01330117=
KDAN 021553Z AUTO 05013G23KT 10SM OVC012 13/12 A2994 RMK AO2
RAB1457E44 SLP131 P0000 T01330117=

TAF KDAN 021739Z 0218/0318 03014G22KT 6SM -RA BR OVC010
FM022200 03019G27KT 4SM RA BR OVC008
FM030900 03014G22KT 6SM -RA BR OVC006=

As bad as that looks, the weather conditions are forecast to stay above minimums – Danville has an ILS to runway 2 that goes to 200 ft. and half a mile of visibility. The crosswind also doesn’t look too bad for the 5900 ft. long runway.

Decision Time

The boss is waiting for you to call back. While the weather is definitely not good, it’s above IFR minimums and it looks like you can stay out of the ice. But it may not be a comfortable ride. Is it safe? Is it comfortable? What do you tell your employer – go or no go? Add a comment below.

6 Comments

  • As one who often elects to “no go” in these scenarios posted by John – because I’m relatively risk averse when it comes to flying through weather (due to my own skills and equipment) – this situation seems rather benign for a pilot with the skills and equipment available as described. It’s a relatively short flight (285 nm), so if the Boss is tolerant of some bumps along the way for a little more than an hour or so, I’d say “go”.

    With the following rather practical caveat – as we’ve seen this week with the hurricane-induced heavy rainfall in South Carolina, flooding could be an issue with this type of stalled low pressure system pulling moisture in from the Atlantic. I’d make a call to the destination airport as well as the designated alternate(s) to see if there is any issue with flooding on the runway, taxiways, apron, hangars, etc., or if any local flood warnings have been issued that may affect the airport It may be safe enough to fly there, but do you really want to land there and then keep your airplane there for the duration of the visit? Or have your Boss stuck at the airport due to flooded roads?

    Interesting scenario, John, thanks!

  • I’d be inclined to go and stay low. But first I would call the boss and make it clear that the weather is crummy and the ride will be bumpy. If he still wants to go, then okay but warn him that if the destination starts going to hell in a handbasket, or if we start picking up anything but rime that the system can easily handle (note: “easily”), we’re going to Plan B. That warm front to the southeast is giving me heartburn. As I see it, that’s the Achilles Heel in my Plans A and B. So no messing around on the icing subject. And be sure on preflight that the deicing system is in good working order. And cycle it when you’re at altitude just to double check.

    Plan B might be somewhere reasonably close to the south or southwest of Danville (the boss could then rent a car), or it might be flying northeast back to KLUK or even beyond depending on the dynamics of the weather system. So carry plenty of gas (I mean top ’em off). If the fuel burn numbers at the low altitude don’t work out to enable you to get at least back to Indy with reserve, then call me “Chicken” and tell the boss sorry but let’s both live to enjoy Christmas this year.

    And make it clear that you’re the Plan B decision-maker . If the boss is unwilling to live with that, then tell him it’s a no-go.

    Oh, and while this might be cheating on this test question, I’d also call an IFR-rated friend who is current and ask if he’d like to get some real weather experience in the right seat. Would be great if he can handle the comm for you while you aviate and navigate.

  • As someone who has owned a C340 and now flies an Aerostar, I know this is one of those days where this type of airplane really shines. They can fly reasonably efficiently anywhere from near the surface up into the mid 20s. The flight is only about 1:15-1:30 in a C340 and you’re not going to be in the bumps for very long — probably mostly on the decent in to KDAN. The plane will easily carry 4 hours plus of fuel. And lastly, the pilot is experienced and current pilot. Overall, you have lots of options.

    Given the data (I’d look more closely at the icing information to get a clearer picture), I’d likely file for 13K knowing that I could descend if the ice and/or the turbulence picked up. I’d also check the TAFs of the other airports in the area (probably to the west or southwest) just in case the weather a KDAN turned out to be worse than advertised.

  • As it turns out, I was flying in that mess during the time period for this and in the vicinity (Dulles to Newark to Richmond, VA). No icing at all (lots of rain, though) and nothing worse than some occasional light chop here and there all the way through the upper teens. En route was better than expected, but approach was a whole different animal. Once below about 4000 into Richmond, we started getting rocked HARD (and this is in a Dash-8; I wouldn’t even want to know what it would have been like in a 340) almost the whole way down and were getting +/- 20 knots of wind shear. Finally, at about 400-500 AGL, it mostly smoothed out again.

    Knowing what the weather actually ended up being, I’d say it would be a go if and only if you and the boss can stand a few minutes of some good thumps. (For what it’s worth, the next day’s conditions were much better as far as the rides went.)

  • I see no reason not to go with that equipment and that pilot. Talk to the boss about a major airport to use as alternate, and be primed to divert if destination goes down.

    It might be because I’m Canadian, but that icing forecast doesn’t sound so scary even for a plane without boots, as long as I don’t have to get over any high hills.

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