CyberAirVA

So how to use all this weather information. Well we will plan a small flight to show. In the bigger airlines they usually have whole departments feeding the pilots weather information, and even the smaller airlines and private pilots will receive information from weather briefs. Now we don't have that kind of personnel behind us when we fly flight simulators which might be a bit sad. But this on the other hand means that we can take this opportunity to learn a bit more about weather. You should read the tutorial on weather reports first though.

The flight
We will depart out of Kendall-Tamiami Executive airport (KTMB), Florida, with our Cessna and fly to Ames field (K8J2) with an IFR flightplan. We will prepare two routes that we can choose from when we decide which one to use, they are:

The routes are important to know when we will check our TWEBs a bit later. So lets pick out a couple of alternative airports to check out too. Airglades (K2IS), Winter Haven's Gilbert (KGIF), Flagler County (KX47) and Keystone Airpark (K42J). We will decide later which ones we will use as alternative airports.

You should check out the Aviation Digital Data Service (ADDS) page. Here you can find mostly graphics, showing the reports. Another good site is the Airline Dispatcher's Federation weather page.
So lets see what we've got then:

AIRMET
The first AIRMET (SIERRA) tells us that there is occasional cloud ceilings below 1000ft with visibility below 2 statute miles due to mist. This condition is developing between 0800 and 1100Z, ending 1300Z. You can see the area in the picture below the AIRMETs.
AIRMET TANGO tells us that no significant turbulence is expected except for around the convective activity (see AIRMET SIERRA).

AIRMET ZULU tells us that there is no significant ice expected outside the convective activity. Freezing levels from 14000ft to 16000ft throughout the whole area (FA = area forecast).

So we will probably fly below 14000ft to avoid the icing and we will probably fly our first route, to get away from the convective area to the east.

MIAS WA 150745
AIRMET SIERRA UPDT 1 FOR IFR VALID UNTIL 151400
.
AIRMET IFR...NC SC
FROM ORF TO ILM TO ODF TO HMV TO ORF
OCNL CIGS BLW 010 VIS BLW 3SM BR. CONDS DVLPG 08-11Z ENDG 13Z.
....
MIAT WA 150745
AIRMET TANGO UPDT 1 FOR TURB VALID UNTIL 151400
.
NO SGFNT TURB EXP EXC INVOF CNVTV ACT.
....
MIAZ WA 150745
AIRMET ZULU UPDT 1 FOR ICE AND FRZLVL VALID UNTIL 151400
.
NO SGFNT ICE EXP OUTSIDE CNVTV ACT.
.
FRZLVL...140-160 THRUT FA AREA.
....

SIGMET
The graphic above tells us that there is one part of the SIGMET that has bearing on our flight, and that is the convective area to the east of Florida.

METARs and TAFs
As one might have expected the METARs were a bit few, since a lot of the smaller airports don't report their weather. But the once below did exist and we will take a look at those. The first one is for Kendall (KTMB) and it tells us that winds are blowing from 200 (deg) with a speed of 10 knots. Visibility is 10SM, clouds are few at 2100ft, temperature is a nice 26 (deg Celsius) with a dew point of 22. The altitude setting is 2989.

Since we couldn't get a METAR for Ames field we will have to settle for Cross City which is pretty close. It tells us that it's an automated station (auto), winds are 240 at 4KT, temp is 26 with a dew point of the same (probably a fault). Altimeter settings are 2980. Notice that the visibility part is missing.

Now to one of our alternative airports, Winter Haven's Gilbert (KGIF). Here we can see that the winds are pretty much as at KCTY, visibility is 10SM, no clouds, alt settings 2986. It looks like the weather will be pretty nice! Actually NO, if we look in the remarks we find a group of six numbers in every one. These tells us that there might be some turbulence later ('5'6013) this turbulence is very strong (5'6'013). It will start at 1000ft (56'01'3 01=base in hundreds of feet) and has a top of 4000ft (5601'3' 3=thickness of the layer in thousands feet). These figures usually can be found in TAFs. They also have nothing to do with the current weather, the persons who preparedthese METARs just wanted to make sure that you would know about the turbulence.

Note that the remarks on the second METAR mentions PWINO (precipitation identifier sensor not operational) and TSNO (thunderstorm information not available).

KTMB 150853Z 20010KT 10SM FEW021 26/22 A2989 RMK AO2 SLP122
T02560217 56015
KCTY 150853Z AUTO 24004KT 26/26 A2980 RMK AO2 SLP089 T02610261
56013 PWINO TSNO
KGIF 150853Z AUTO 22007KT 10SM CLR 24/23 A2986 RMK AO2 SLP110
T02390233 58015

The TAF for Kendall tells us that we can expect winds from 240 (deg) at 6KT, plus 6SM visibility, scattered clouds at 3000ft, broken at 12000ft. >From 1400Z wind 250 at 10KT, plus 6SM visibility, scattered at 3000ft. Occasional (TEMPO) between 17Z and 20Z, 2SM, heavy thunderstorm showers, rain, CB (cumulonimbus) broken clouds at 2000ft. From 2000Z winds 230 at 15KT, plus 6SM, scattered at 3000ft, broken at 12000ft. Probably after 2001Z 3SM visibility, thunderstorm showers and rain, CB broken clouds at 2500ft. From 0100Z winds 230 at 6KT, plus 6SM visibility, clouds few at 3000ft and scattered at 12000ft, scattered at 25000ft.

So what does this mean to our flight? Well the weather is forecasted to become worse after 1400Z so, we will try to get away before then. But just to check we will check the TAF for Gainesville Regional Airport (KGNV) which is pretty close to where we are heading (note that this isn't the correct way to do it since the TAF only forecasts the weather within 5nm of the station, but it's better than not having any forecasted weather). This tells us that the weather will be pretty nice until after 1700Z, when it will start to go sour there too. This shouldn't be a problem though as we will probably have landed by then.

We have now showed you the importance of TAFs, the METARs told us that the weather was fine (although it mentions the worsening weather in it's remarks), and if we hadn't checked the TAFs, the worsening weather might have taken us by surprise. Note that in real life the weather briefer would have let us know about the coming weather change.

KMLB 150529Z 150606 24006KT P6SM SCT030 BKN120
FM1400 25010KT P6SM SCT030
TEMPO 1720 2SM +TSRA BKN020CB
FM2000 23015KT P6SM SCT030 BKN120 PROB30 2001 3SM TSRA
BKN025CB
FM0100 23006KT P6SM FEW030 SCT120 SCT250

KGNV 150805Z 150806 25005KT P6SM SCT015 BKN120
TEMPO 0913 5SM BR BKN015
FM1300 27007KT P6SM FEW030
FM1700 27010KT P6SM SCT040 PROB30 1723 VRB15G25KT 2SM +TSRA
BKN020CB

TWEBs
The TWEBs will show the weather in a corridor of 50nm along the route. Lets split the TWEBs into their respective route.

Route 1
The first part of the route is 115, so lets check that TWEB out. It tells us that all the heights are in AGL except for tops. It's split into two parts, KMIA (Miami) - 50(nm) southwest of KMIA and 50SW of KMIA to KEYW (Key West). We are only interested in the first part though. Before 17Z visibility will plus 6SM, few clouds at 2500ft and visibility sometimes falling below 3SM. The weather will be quite bad, After 17Z it will get worse though, surface winds might be gusting to 30KT.

The second part of this route is 116 and it says that essentially there will be some clouds and after 18Z the weather will get worse, surface winds gusting to 30KT. Visibility sometimes below 3SM.

Next part is 117 and this tells us that the weather will get worse after 13Z with visibility as low as 1/2SM, before getting a bit better after 19Z.

Route 2
The first is the same as above (115).
The second part is 082 and here we can see that we have some clouds and after 17Z visibility will drop to below 1SM.

The third part is 081 and it tells us that it will have some pretty good weather that will turn a bit worse after 16Z and 17Z, visibility will for example drop to 2SM.

So which route to choose. It doesn't look like any of the routes will be spared from the bad weather (note that the bad weather means rain, showers and gusting winds in certain places). I think we should wait with the deciding a bit.

081 TWEB 150820 KPBI-KVRB-KORL. ALL HGTS AGL XCP TOPS. KPBI-KVRB
TIL 14Z P6SM FEW-SCT030 SCT120 BKN250...14Z-17Z P6SM SCT025
SCT250... AFT 17Z P6SM SCT025 BKN060 SCT 2SM +TSRA BKN025CB.
KVRB-KORL TIL 14Z P6SM FEW-SCT030 SCT-BKN120...14Z-16Z P6SM
SCT030...AFT 16Z P6SM SCT030 BKN120 SCT 2SM +TSRA
BKN025CB.=
082 TWEB 150820 KMLB-KPBI-KMIA. ALL HGTS AGL XCP TOPS. P6SM
SCT025- 030 SCT-BKN 100 BKN250...AFT 17Z SCT CIGS BLO 010
VSBY BLO 1SM +TSRA.=
115 TWEB 150820 KMIA-KEYW. ALL HGTS AGL XCP TOPS. KMIA-50SW KMIA
TIL 17Z P6SM FEW025 WITH ISOLD BLO 3SM +SHRA AND +TSRA
BKN008...AFT 17Z P6SM SCT025 WITH LCL BKN025 BKN060 AND NMRS
BLO 3SM +SHRA AND +TSRA BKN008 WITH ISOLD SFC WND G30KT.
50SW KMIA-KEYW P6SM FEW-SCT025 WITH ISOLD BLO 3SM +SHRA AND
+TSRA BKN008.=
116 TWEB 150820 KMIA-KFMY-KTPA. ALL HGTS AGL XCP TOPS. KMIA-50NM
NW KMIA TIL 15Z P6SM SCT025 BKN250...15Z-18Z P6SM SCT LCL
BKN025 BKN250...AFT 18Z P6SM SCT025 BKN060 BKN250 WITH SCT
SFC WND G25KT VSBY BLO 3SM +TSRA BKN015CB. 50NM NW
KMIA-KFMY-KTPA TIL 13Z P6SM SCT020 SCT-BKN080 BKN250 WITH
WDLY SCT 3-5SM SHRA BKN020...AFT 13Z P6SM SCT020 BKN080
BKN250 WITH SCT SFC WND G25KT VSBY BLO 3SM +TSRA
BKN015CB.=
117 TWEB 150820 KTPA-KCTY-KTLH. ALL HGTS AGL XCP TOPS. KTPA-60NM N
KTPA TIL 13Z P6SM SCT-BKN020 BKN080 WDLY SCT 3-5SM
SHRA...AFT 13Z P6SM BKN080 SCT 1-2 1/2SM +TSRA CIGS
OVC015-025. 60NM N KTPA- KTLH TIL 13Z P6SM BKN250 AREAS
3-5SM BR...13Z-19Z P6SM BKN250... AFT 19Z P6SM SCT060 AREAS
BKN070.=

Satellite and Radar
If we first take a look at the satellite image (is taken at night and is therefore infraread) we can see the convective area which we could see in the AIRMET and SIGMET to the east of Florida. We can also see the new area which is going to bring in the bad weather on the west coast.
If we look at the two radar images showing precipitation we can see the two areas here two. So in short the images confirm what we already know. Remember that the radar images can be somewhat distorted, you should therefore check a bunch of radar images along your route.

PIREPs
The PIREPs images shows us that there has been reports of turbulence and icing where we are going. It also tells us that that have been between 27000ft and 29000ft. So that's no problem. There were no reports showing any weather or sky conditions of significance.

So which flight plan should we use, I would go with the second because of the lower wind speed on that route (below 15KT), but we could just as easily go with the first. It also depends on how early we fly. Remember that before 13Z in one area and 17Z in most others the weather and winds are pretty good for an IFR flight. Since icing has been reported at 12000ft I would fly below it if the surface allows it, otherwise go above it. If you fly a bit later you might want to cancel the flight or go later. You probably don't want to try and land with winds gusting at 30KT, not in a little Cessna at least. If you decide to go, be prepared for the worsening weather and don't be afraid to land at one of the airports on the way. Remember that thunderstorms is a growing ground for low-level wind shear (LLWS) and microbursts, you don't want to run into any of them flying a little Cessna. Safety first, always! Also remember to check the present weather just before you leave, the forecasts aren't always right.