[PPRAANet] 4th of July Solar Conditions from NA5N

[W0rw at aol.com]

Gang, 


Below is today's (friday 7-1) report on solar and geophysical activity, 

annotated a bit.  Generally, conditions should be quite good, with the solar 

flux even rising to around 100. 



> Joint USAF/NOAA Report of Solar and Geophysical Activity

> SDF Number 181 Issued at 2200Z on 30 Jun 2005


> IA.  Analysis of Solar Active Regions and Activity from  29/2100Z

> to 30/2100Z:  Solar activity has been very low.  Regions 782 (S17W04)

> and 783 (S02E45) exhibited moderate growth, and both maintained a

> beta magnetic configuration. 


A beta configuration means the magnetic field lines of the disturbance are 

getting organized and strong, often a precursor sign of a flare.  But, it 

has a long ways to go to produce a flare of any significance. 


> IB.  Solar Activity Forecast:  Solar activity is expected to be very

> low to low.  Regions 782 and 783 may produce C-class flares.


C-class flares seldom effect HF propagation, unless it happens right smack 

in the middle of the sun.  Even there, a few hour minor geomagnetic storm 

might result. 


> IIA.  Geophysical Activity Summary 29/2100Z to 30/2100Z:

> The geomagnetic field has been quiet to unsettled.  Solar wind speed

> at ACE has remained below 400 km/s.  


This is pretty low for the solar wind.  The solar wind has been just about 

the particle escape velocity of the sun, around 350 km/sec.  However, we got 

hit with a 700 km/sec. sudden onset a couple of hours ago from a coronal 

hole stream, triggering a minor geomagnetic storm, K=4 and K=5.  No biggie, 

actually, other than generating some enhanced noise on the low HF bands. 


> The greater than 2 MeV electron flux at geosynchronous orbit reached high > 
levels today.


This may be a concern to some satellite operators, but no threat to HF. 


> IIB.  Geophysical Activity Forecast:  The geomagnetic field is

> expected to be quiet to active, with an isolated chance of minor

> storm activity, on 1-2 July as a coronal hole solar wind stream

> reaches geoeffective position.


Well, the "isolated chance" occured, as noted above.  The solar wind, 

increasing suddenly from <400 km/sec. to over 700 km/sec. caused a 

compression to our magnetic field, and with it, some HF noise.  It is not a 

serious event. 


Once we leave the coronal hole stream, probably tomorrow, our magnetic field 

will settle down, solar wind will return to 350-400 km/sec., meaning some 

fairly nice and quiet conditions for the rest of the weekend.  K=1 and K=2 

stuff. 


> III.  Event Probabilities 01 Jul-03 Jul

> Class M    05/05/05

> Class X    01/01/01

> Proton     01/01/01

> PCAF       green


The above states there is <5% chance for an M-class flare to trigger any 

excitement.  The green PCAF means conditions are even quite nice for our 

friends up north. 


> IV.  Penticton 10.7 cm Flux

> Observed           30 Jun 103

> Predicted   01 Jul-03 Jul  100/105/105

> 90 Day Mean        30 Jun 092


The 70-80 solar flux last weekend for FD has increased to 100-105 for the 

4th of July weekend.  Conditions on 20M and above will be a bit better than 

that experienced last weekend.  15M and even some 10M openings are possible. 


> V.  Geomagnetic A Indices

> Observed Afr/Ap 29 Jun  004/006

> Estimated Afr/Ap 30 Jun  005/006

> Predicted Afr/Ap 01 Jul-03 Jul  010/020-012/020-008/015


This means the geomagnetic field should be fairly quiet next 3 days.  

However, this prediction obviously did not anticipate such a blast from the 

coronal hole.  With the K-index already at 4, you can bet that the averaged 

A-index for 1 July will be more than 20!  But, it should subside back to the 

quiet conditions predicted above for saturday afternoon onward. 


Remember, the solar flux indicates conditions on 20/15/10M, while the K 

index is more indicative of noise conditions on 30/40/80/160M.  Once the 

current geomagnetic activity settles down, the bands should be about as good 

to be expected for the rest of the weekend. 


Have a good 4th of July with family and friends, and of course, on the air 

if you have the time. 


72, Paul NA5N