There are some known effects already studied for several decades such as ionoshperic scintillations. In a very simple and crude method, the signal strength of a VHF (or UHF) signal from a satellite can be monitored continuously. In the 1990s I was associated with such a setup around 400MHz with a crossed YAGI array to receive a signal from a Japanese satellite. So, to conclude, yes there are ionospheric effects observed for the VHF/UHF signals. I may be wrong but I am not in favor to assume that there are no ionospheric/space weather effects observed on VHF/UHF signals. Also, if you go beyond the ionosphere, i.e. in the space vacuum, again there are some disturbances observed in the propagation of radio signals. These are referred as the interplanetary scintillations. Physical Research Laboratory in Ahmedabad, India was operating at Thaltej one such IPS Radio Telescope around 103MHz which falls in the VHF band. Unfortunately it is not active and totally dismantled. But you can search for literature in this field.

In recent years, GPS signals are used to study the ionospheric variations including to determine the electronic density or Total Electroinc Contents (TEC) of the ionosphere. Although the GPS frequencies operate well above the VHF band or the upper end of UHF usually called as microwave frequencies (L-Band), so yes, there are very-well known effects that are studied and vast literature is available in this area too!

I hope this gives a satisfactory answer to your question.

Wishing you best luck in your work!

Ionospheric scintillations, usually studied with the GNSS signals (L band), are also visible on VHF signals. DIffraction effect that causes the scintillations are due to different size ionospheric irregularities depending on the frequency of the signal. In other words, each frequency is influenced by  an irregularity on the electron density of a particular scale size (Fresnel filter). Scintillations are mainly visible in low and high latitude but the origin of the phenomena in the two regions is quite different. This is one of the reason why the few Incoherent scatter radar (working in VHF region) in the world can be found in the equatorial and polar region.

Hope to help you!

Best

The ionosphere is immediately disturbed by X-rays from a solar flare and then by any protons produced. Some 15 hours to 2 days later a strong coronal mass ejection might create a geomagnetic disturbance that precipitates radiation belt electrons into the atmosphere giving several days of ionospheric disturbance. HF reflections are disturbed and VHF and UHF coming through the ionosphere are subject to dispersion and scintillation. During an extreme event satcoms and GPS might be unavailable for several days. Please see the Royal Academy of Engineering report on Extreme Space Weather produced in February 2013 and available from their website.