Site radar
2 min read

Today’s flight is a quick one, from the Atlantic coast of Florida (West Palm Beach, PBI) to the Gulf Coast (Tampa, TPA). You’re headed home after a week of meetings in Palm Beach, and your 1979 Mooney 201 will get you there in just about an hour. Your airplane has no on-board weather, but you do fly with an iPad and a portable ADS-B weather receiver. You are instrument rated, and between your datalink radar and your eyes, you are pretty good at dodging the inevitable Florida thunderstorms.

The weather doesn’t look too bad as you drive to the airport around noon, but the afternoon is yet to come. In Florida, you’ve learned to expect the unexpected, as conditions change quickly. Read the weather report below, then decide if you’re going or not going.


There’s no serious weather system that should affect your flight, just a cold front far to the northwest that won’t move through for at least 24 hours. But the surface analysis does show a weak trough across the state of Florida:

Florida surface analysis

Radar and Satellite

These are the weather products to watch today, as usual for Florida. The regular afternoon thunderstorms haven’t blossomed up yet, but there is an area right in the middle of the state that could be an issue for your flight:

Regional NEXRAD

The site radar adds some additional detail:

Site radar

Finally, the visible satellite image shows the building cumulus:

Visible satellite image

Text Weather

Weather at your departure and destination looks pretty good, although there are the typical warnings about thunderstorms and towering cumulus in the area. Your departure forecast calls for thunderstorms to move in between noon and 4pm.

KPBI 181553Z 12004KT 10SM BKN025CB BKN043 BKN060 30/24 A2987 RMK AO2
KPBI 181532Z 14005KT 10SM SCT016 BKN023CB BKN043 29/24 A2987 RMK AO2
KPBI 181453Z 11004KT 10SM SCT016CB BKN049 BKN110 29/24 A2988 RMK AO2
TAF AMD KPBI 181610Z 1816/1912 14010KT P6SM VCTS SCT025CB BKN040 BKN060
     TEMPO 1816/1820 5SM TSRA BKN025CB
     FM190300 18004KT P6SM SCT070 SCT100=
KTPA 181553Z VRB04KT 10SM FEW030 SCT250 27/21 A2989 RMK AO2 SLP120
KTPA 181453Z 14004KT 10SM FEW035 SCT085 SCT250 25/22 A2990 RMK AO2
    RAE05 SLP124 P0000 60010 T02500217 50004=
TAF AMD KTPA 181511Z 1815/1912 15005KT P6SM FEW035
     FM181800 23007KT P6SM SCT035
     FM182200 28008KT P6SM FEW040 SCT250
     FM190200 VRB03KT P6SM SCT250=

You Make the Call

So what will you do? There certainly isn’t a large, organized front, and the weather at your destination is excellent. But the thunderstorms are starting to brew, and in Florida, things can change dramatically in 15 minutes. Add a comment below and tell us your decision and why.

John Zimmerman
19 replies
  1. Mike
    Mike says:

    On second thought. I wouldn’t go. There looks like a line developing between PBI and TPA that would be hard to work around without radar.

  2. Ben Conley
    Ben Conley says:

    Well I sure would not fly direct… that trough is going to make things a little to rough… How about going over to Fort Myers then up the coast. If it is bad when you get there spend the night there and you will be real close in the morning. It is only 65-70 miles across the state… thunderstorms are a normal occurrance if they are isolated fly around them, otherwise go back where you came from.

  3. Larry Baum
    Larry Baum says:

    There is a couple of choices here. Head toward Ft. Meyers and cut the corner east of FMY heading northwest to TPA. The other option could be heading up the coast past Ft Peirce, then head west to TPA. The challenge with that choice might require going off shore. Both choices have plenty of airports to land short if necessary. There’s actually more options going up the coast.

    In the end, local knowledge helps a lot. If the pilot is from FL and heading home, he’ll have a better idea than this me from the Northeast of which option to take. I’d be asking the locals at the PBI FBO for their reccomendation.

  4. ken
    ken says:

    If I didn’t see the date on the images I would think this is from a flight I actually had about four weeks ago from PBI to TPA. The storms popped up just as shown above. I had little problem going around to the west. I was an a turbo Arrow with sat Nexrad and a strike finder.

    GO VFR and be prepared to deviate a long way from your intended course. Choose the direction to start (north or west) based on the movement of the storms. Also be prepared to land and wait it out. You may even have to finish the flight in the dark, IFR, after all the storms die out.

  5. Larryo
    Larryo says:

    This is a go for sure… no brainer, we have this stuff all the time in FL, and looking at the charts it has not significantly lined up at all, nor is there any indication of severe trws, but I’d reserve the right to get more info.

    Also, bases are reasonably high (and need the rest of the metars between departure and destination.

    I may have flown thru this a few weeks ago, we’ve had a lot of this lately. However, had no XM, but did have radar and SS. It’s rare that trws will stop one in FL… may delay and deviate, but it’s often non violent, very wet and has holes in it or building and dissipating all the time.

    Also, if the charts are like they appear at time of departure, I’d bet one could go direct and fly thru the hole northwest of Lake Okeechobee, toward Sebring… light rain there. However, close to the restricted area, so if it got tight, one could head around the south west of it toward FMY and come up the center of the state.

    Also, all forecasts are VFR, with good vis and ceilings….

    This one is easy… wait til they line up and get nasty. And they you wait til after dark and go home after they have dissipated.

    • Matt Warmerdam
      Matt Warmerdam says:

      Typical airmass thunderstorms, not part of a frontal line. I think the TRW postition information uplinked from the ADS to the Ipad would be fairly accurate on position but perhaps not intensity (time delay). Circumnavigating south or north along the eastern shore then heading west shouldn’t be a problem, plenty of gas to divert. I would go.


  6. Michel Samson
    Michel Samson says:

    This is a typical daily occurrence in South Florida. At this point it looks okay for departure to the west, then north long the coastline to TPA. Consider VFR. If you wait until later in the afternoon it may get worse with the trough in place. So I would either go right away, or spend some time in lovely Palm Beach and do a night flight after the storms dissipate. The typical air mass TS in Florida are very localized and generally circumnavigable, and usually dissipate in the early evening.

  7. Nate_fl
    Nate_fl says:

    As a Florida pilot we often deal with summer T-storms. Most TRW in the summer are fairly localized phenomena. We often have sea breeze convection where the wind flows in off both coasts. Where the sea breeze fronts converge is usually where you get convective activity. In fact most glider pilots in Florida use the convergence as a source of lift, if the cloud bases aren’t too low. Running up the coasts usually means avoiding TRW.

    True frontal weather (which only happens 4-5 months a year) and squall line t-storms are another matter, and should be avoided unless you have airborne radar, IMO. You can usually see that coming though.

    Florida is also littered with GA friendly airports, except for when you are in the Everglades, you are rarely more than 50nm from a suitable divert field. So this is a go, to me.

  8. Peg Ballou
    Peg Ballou says:

    I wish you would make these exercises in printable format so that I can use them with my students. Yes, I can print them, but they have lots of extra “stuff” on them, and they are invaluable for decisionmaking scenarios. Thanks for providing such a good resource.

  9. Mark Fay
    Mark Fay says:

    A classic for Mr. Collins philosophy of “Start and Continue” vs. Go or No Go.

    In fact, I never think of Go or No Go. Instead:

    1.) Can I Start with some reasonable possiblity of success? Is the weather good for the first 20 minutes for a short flight or 100 miles or so for longer ones?
    2.) And, always, every minute, evaluating whether or not I should Continue.

    I’d START this flight then evaluate if I could CONTINUE.

    I flew N182SP a TR182 from Hot Springs to Addision on Monday which was also a classic “Start / Continue”. Briefer was saying “Don’t Go.” I didn’t. Instead I STARTED. And, I continuouly evaluated if I could continue with my haven being Tyler TX.

    As so often happens, the WX opened up and I went thru safely, comfortably and reasonably on time. Quite a bit of fun in the challenge, too. Thanks Mr. Collins. I’ve read Perfect Flight and Practical IFR at least 4 times each.

  10. Vicki B.
    Vicki B. says:

    I would want to look at any radars located on the west side before making my decision. If the lines of storms do not continue out to sea, I might go VFR toward Fort Myers. However, starting across Florida at noon means you need that information from the ads-b. Since the movement of the ts is N, I think it might be a go with a routing that gives me various escape airports.

  11. Stephen W.
    Stephen W. says:

    This is very typical weather for south FL. I have made this flight many times. What I have learned is not to file and fly IFR on this route when there is a chance of TS. I would head west to the FMY area and head up the coast off shore to TPA. Most likely the TS have not built over the water, they are building over the land. FL flying, “over land by night”, “over water by day” when there are expected TS.

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