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SFI:81  A:16  K:3 @ 2017 Apr 25 2105 UTC   Π
(actualizado: 20170425T2315)
No space weather storms were observed for the past 24 hours.
Space weather for the next 24 hours is predicted to be minor.
Geomagnetic storms reaching the G1 level are likely.

HF band conditions for EA (from www.bandconditions.com)


Maxima Frecuencia Utilizable (MUF) from www.spacew.com



Max NVIS Freq from www.sws.bom.gov.au

The above map can be used as a guide to NVIS ionospheric frequency support and to generate real time HF predictions (eg Hourly HAP charts) to assist the HF radio communicator.


A & K indexes

Daily K index
for today
3 hourly K index
for last 3 days
Space Weather Prediction Center
3 hourly K index
for last 30 days
Daily A index
for last 30 days


Solar flux


D Region Absorption Predictions


MUF explained

¿Como determinar la MUF (maxima frecuencia utilizable)?
1- Para trayectos de 3.000 Km: Situe sobre el mapa el punto medio del trayecto y obtenga el valor del contorno en ese punto. Todos los valores de los contornos se dan en MHz.

2- Para trayectos de 4.000 Km: Siga la regla anterior y multiplique el valor de la MUF obtenida por 1,1.

3- Para trayectos de mas de 4.00 Km: Divida el trayecto en segmentos de 3.000 y 4.000 km y calcule la MUF en los dos puntos medios que se encuentran a 1.500 o 2.000 km de cada extremo del trayecto. A continuacion seleccione la menor de las dos MUF.

Understanding HF propagation conditions


Category

Radio Blackouts
Use X-Ray

Solar Radiation Storms
Use Proton Flux

Geomagnetic Storms
Use K-Index/K-nT/
Aurora/Solar Wind/Bz

Band Openings
Use Solar Flux (SN)

Electron Alert
Use Electron Flux

Extreme

X20

Complete HF blackout on entire sunlit side lasting hours

1.000.000
Complete HF blackout in polar regions

K=9 (nT=>500) [Aur=10++] (SW=>800) [Bz=-40 -50]
HF impossible. Aurora to 40º. Noise S30+.

200-300 (SN=160-250)
Reliable communications all bands up through 6m

>1000 Alert
Partial to complete HF blackout in polar regions

Severe

X10
HF blackout on most of sunlit side for 1 to 2 hours

100.000
Partial HF blackout in polar regions

K=8 (nT=330-500) [Aur=10+] (SW=700-800) [Bz=-30 -40
HF sporadic.
Aurora to 45º

Noise S20-S30.

Strong

X1
Wide area HF blackout for about an hour on sunlit side

10.000
Degraded HF propagation in polar regions

K=7 (nT=200-330) [Aur=10] (SW=600-700) [Bz=-20-30]
HF intermittent. Aurora to 50º. Noise S9-S20.

150-200 (SN=105-160)
Excellent conditions all bands up through 10m w/6m openings

Moderate

M5
Limited HF blackout on sunlit side for tens of minutes

1000
Small effects on HF in polar regions

K=6 (nT=120-200) [Aur=9] (SW=500-600) [Bz=-10 -20]
HF fade higher lats. Aurora to 55°. Noise S6-S9.

120-150 (SN=70-105)
Fair to good conditions all bands up through 10m

<1.0e+03 Active>


<1000 Active

Degraded HF propagation in polar regions

Minor

M1
Occasional loss of radio contact on sunlit side

100
Minor impacts on HF in polar regions

K=5 (nT=70-120) [Aur=8] (SW=400-500) [Bz=0 -10]
HF fade higher lats. Aurora to 56º. Noise S4-S6.

90-120 (SN=35-70)
Fair conditions all bands up through 15m

<1.0e+02 Active>


<100 Active

Minor impacts on HF in polar regions

Active

C1
Low absorption of HF signals

10
Very minor impacts on HF in polar regions

K=3-4 (nT=20-70) [Aur=6-7] (SW=200-400) [Bz=0 -+50]

Minor HF fade higher lats. Aurora 60-58°. Noise S2-S3.

70-90 (SN=10-35)
Poor to fair conditions all bands up through 20m

<1.0e+01 Normal>


<10 Normal

No impacts on HF

Normal

A1-B9
No or very minor impact to HF signals

1
No impacts on HF

K=0-2 (nT=0-20) [Aur=<5] (SW=200-400) [Bz=0-+50] Inactive/Quiet><5]

(SW=200-400)[Bz=0 -+50]

No impacts on HF. Aurora 67-62°. Noise S0-S2.

64-70 (SN=0-10)
Bands above 40m unusable

<1.0e+00 Normal>


<1 Normal

No impacts on HF